diff options
Diffstat (limited to '')
40 files changed, 14922 insertions, 0 deletions
diff --git a/src/nspawn/fuzz-nspawn-oci.c b/src/nspawn/fuzz-nspawn-oci.c new file mode 100644 index 0000000..5d03834 --- /dev/null +++ b/src/nspawn/fuzz-nspawn-oci.c @@ -0,0 +1,26 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include "alloc-util.h" +#include "fd-util.h" +#include "fuzz.h" +#include "nspawn-oci.h" + +int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) { + _cleanup_fclose_ FILE *f = NULL; + _cleanup_(settings_freep) Settings *s = NULL; + + if (outside_size_range(size, 0, 65536)) + return 0; + + f = data_to_file(data, size); + assert_se(f); + + /* We don't want to fill the logs with messages about parse errors. + * Disable most logging if not running standalone */ + if (!getenv("SYSTEMD_LOG_LEVEL")) + log_set_max_level(LOG_CRIT); + + (void) oci_load(f, "/dev/null", &s); + + return 0; +} diff --git a/src/nspawn/fuzz-nspawn-oci.options b/src/nspawn/fuzz-nspawn-oci.options new file mode 100644 index 0000000..678d526 --- /dev/null +++ b/src/nspawn/fuzz-nspawn-oci.options @@ -0,0 +1,2 @@ +[libfuzzer] +max_len = 65536 diff --git a/src/nspawn/fuzz-nspawn-settings.c b/src/nspawn/fuzz-nspawn-settings.c new file mode 100644 index 0000000..40ee784 --- /dev/null +++ b/src/nspawn/fuzz-nspawn-settings.c @@ -0,0 +1,26 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include "alloc-util.h" +#include "fd-util.h" +#include "fuzz.h" +#include "nspawn-settings.h" + +int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) { + _cleanup_fclose_ FILE *f = NULL; + _cleanup_(settings_freep) Settings *s = NULL; + + if (outside_size_range(size, 0, 65536)) + return 0; + + f = data_to_file(data, size); + assert_se(f); + + /* We don't want to fill the logs with messages about parse errors. + * Disable most logging if not running standalone */ + if (!getenv("SYSTEMD_LOG_LEVEL")) + log_set_max_level(LOG_CRIT); + + (void) settings_load(f, "/dev/null", &s); + + return 0; +} diff --git a/src/nspawn/fuzz-nspawn-settings.options b/src/nspawn/fuzz-nspawn-settings.options new file mode 100644 index 0000000..678d526 --- /dev/null +++ b/src/nspawn/fuzz-nspawn-settings.options @@ -0,0 +1,2 @@ +[libfuzzer] +max_len = 65536 diff --git a/src/nspawn/meson.build b/src/nspawn/meson.build new file mode 100644 index 0000000..f6cca70 --- /dev/null +++ b/src/nspawn/meson.build @@ -0,0 +1,85 @@ +# SPDX-License-Identifier: LGPL-2.1-or-later + +libnspawn_core_sources = files( + 'nspawn-bind-user.c', + 'nspawn-bind-user.h', + 'nspawn-cgroup.c', + 'nspawn-cgroup.h', + 'nspawn-creds.c', + 'nspawn-creds.h', + 'nspawn-def.h', + 'nspawn-expose-ports.c', + 'nspawn-expose-ports.h', + 'nspawn-mount.c', + 'nspawn-mount.h', + 'nspawn-network.c', + 'nspawn-network.h', + 'nspawn-oci.c', + 'nspawn-oci.h', + 'nspawn-patch-uid.c', + 'nspawn-patch-uid.h', + 'nspawn-register.c', + 'nspawn-register.h', + 'nspawn-seccomp.c', + 'nspawn-seccomp.h', + 'nspawn-settings.c', + 'nspawn-settings.h', + 'nspawn-setuid.c', + 'nspawn-setuid.h', + 'nspawn-stub-pid1.c', + 'nspawn-stub-pid1.h', + 'nspawn-util.c', + 'nspawn-util.h', + 'nspawn.h', +) + +nspawn_gperf_c = custom_target( + 'nspawn-gperf.c', + input : 'nspawn-gperf.gperf', + output : 'nspawn-gperf.c', + command : [gperf, '@INPUT@', '--output-file', '@OUTPUT@']) + +libnspawn_core_sources += [nspawn_gperf_c] + +libnspawn_core = static_library( + 'nspawn-core', + libnspawn_core_sources, + include_directories : includes, + dependencies : [libacl, + libseccomp, + libselinux], + build_by_default : false) + +systemd_nspawn_sources = files('nspawn.c') + +############################################################ + +tests += [ + [files('test-nspawn-tables.c'), + [libnspawn_core, + libshared], + [libseccomp]], + + [files('test-nspawn-util.c'), + [libnspawn_core, + libshared], + [libseccomp]], + + [files('test-patch-uid.c'), + [libnspawn_core, + libshared], + [libacl], + [], '', 'manual'], +] + +fuzzers += [ + [files('fuzz-nspawn-settings.c'), + [libshared, + libnspawn_core], + [libseccomp]], + + [files('fuzz-nspawn-oci.c'), + [libshared, + libnspawn_core], + [libseccomp]], +] diff --git a/src/nspawn/nspawn-bind-user.c b/src/nspawn/nspawn-bind-user.c new file mode 100644 index 0000000..7a7a19f --- /dev/null +++ b/src/nspawn/nspawn-bind-user.c @@ -0,0 +1,474 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include "chase-symlinks.h" +#include "fd-util.h" +#include "fileio.h" +#include "format-util.h" +#include "nspawn-bind-user.h" +#include "nspawn.h" +#include "path-util.h" +#include "user-util.h" +#include "userdb.h" + +static int check_etc_passwd_collisions( + const char *directory, + const char *name, + uid_t uid) { + + _cleanup_fclose_ FILE *f = NULL; + int r; + + assert(directory); + assert(name || uid_is_valid(uid)); + + r = chase_symlinks_and_fopen_unlocked("/etc/passwd", directory, CHASE_PREFIX_ROOT, "re", NULL, &f); + if (r == -ENOENT) + return 0; /* no user database? then no user, hence no collision */ + if (r < 0) + return log_error_errno(r, "Failed to open /etc/passwd of container: %m"); + + for (;;) { + struct passwd *pw; + + r = fgetpwent_sane(f, &pw); + if (r < 0) + return log_error_errno(r, "Failed to iterate through /etc/passwd of container: %m"); + if (r == 0) /* EOF */ + return 0; /* no collision */ + + if (name && streq_ptr(pw->pw_name, name)) + return 1; /* name collision */ + if (uid_is_valid(uid) && pw->pw_uid == uid) + return 1; /* UID collision */ + } +} + +static int check_etc_group_collisions( + const char *directory, + const char *name, + gid_t gid) { + + _cleanup_fclose_ FILE *f = NULL; + int r; + + assert(directory); + assert(name || gid_is_valid(gid)); + + r = chase_symlinks_and_fopen_unlocked("/etc/group", directory, CHASE_PREFIX_ROOT, "re", NULL, &f); + if (r == -ENOENT) + return 0; /* no group database? then no group, hence no collision */ + if (r < 0) + return log_error_errno(r, "Failed to open /etc/group of container: %m"); + + for (;;) { + struct group *gr; + + r = fgetgrent_sane(f, &gr); + if (r < 0) + return log_error_errno(r, "Failed to iterate through /etc/group of container: %m"); + if (r == 0) + return 0; /* no collision */ + + if (name && streq_ptr(gr->gr_name, name)) + return 1; /* name collision */ + if (gid_is_valid(gid) && gr->gr_gid == gid) + return 1; /* gid collision */ + } +} + +static int convert_user( + const char *directory, + UserRecord *u, + GroupRecord *g, + uid_t allocate_uid, + UserRecord **ret_converted_user, + GroupRecord **ret_converted_group) { + + _cleanup_(group_record_unrefp) GroupRecord *converted_group = NULL; + _cleanup_(user_record_unrefp) UserRecord *converted_user = NULL; + _cleanup_free_ char *h = NULL; + JsonVariant *p, *hp = NULL; + int r; + + assert(u); + assert(g); + assert(u->gid == g->gid); + + r = check_etc_passwd_collisions(directory, u->user_name, UID_INVALID); + if (r < 0) + return r; + if (r > 0) + return log_error_errno(SYNTHETIC_ERRNO(EBUSY), + "Sorry, the user '%s' already exists in the container.", u->user_name); + + r = check_etc_group_collisions(directory, g->group_name, GID_INVALID); + if (r < 0) + return r; + if (r > 0) + return log_error_errno(SYNTHETIC_ERRNO(EBUSY), + "Sorry, the group '%s' already exists in the container.", g->group_name); + + h = path_join("/run/host/home/", u->user_name); + if (!h) + return log_oom(); + + /* Acquire the source hashed password array as-is, so that it retains the JSON_VARIANT_SENSITIVE flag */ + p = json_variant_by_key(u->json, "privileged"); + if (p) + hp = json_variant_by_key(p, "hashedPassword"); + + r = user_record_build( + &converted_user, + JSON_BUILD_OBJECT( + JSON_BUILD_PAIR("userName", JSON_BUILD_STRING(u->user_name)), + JSON_BUILD_PAIR("uid", JSON_BUILD_UNSIGNED(allocate_uid)), + JSON_BUILD_PAIR("gid", JSON_BUILD_UNSIGNED(allocate_uid)), + JSON_BUILD_PAIR_CONDITION(u->disposition >= 0, "disposition", JSON_BUILD_STRING(user_disposition_to_string(u->disposition))), + JSON_BUILD_PAIR("homeDirectory", JSON_BUILD_STRING(h)), + JSON_BUILD_PAIR("service", JSON_BUILD_CONST_STRING("io.systemd.NSpawn")), + JSON_BUILD_PAIR_CONDITION(!strv_isempty(u->hashed_password), "privileged", JSON_BUILD_OBJECT( + JSON_BUILD_PAIR("hashedPassword", JSON_BUILD_VARIANT(hp)))))); + if (r < 0) + return log_error_errno(r, "Failed to build container user record: %m"); + + r = group_record_build( + &converted_group, + JSON_BUILD_OBJECT( + JSON_BUILD_PAIR("groupName", JSON_BUILD_STRING(g->group_name)), + JSON_BUILD_PAIR("gid", JSON_BUILD_UNSIGNED(allocate_uid)), + JSON_BUILD_PAIR_CONDITION(g->disposition >= 0, "disposition", JSON_BUILD_STRING(user_disposition_to_string(g->disposition))), + JSON_BUILD_PAIR("service", JSON_BUILD_CONST_STRING("io.systemd.NSpawn")))); + if (r < 0) + return log_error_errno(r, "Failed to build container group record: %m"); + + *ret_converted_user = TAKE_PTR(converted_user); + *ret_converted_group = TAKE_PTR(converted_group); + + return 0; +} + +static int find_free_uid(const char *directory, uid_t max_uid, uid_t *current_uid) { + int r; + + assert(directory); + assert(current_uid); + + for (;; (*current_uid) ++) { + if (*current_uid > MAP_UID_MAX || *current_uid > max_uid) + return log_error_errno( + SYNTHETIC_ERRNO(EBUSY), + "No suitable available UID in range " UID_FMT "…" UID_FMT " in container detected, can't map user.", + MAP_UID_MIN, MAP_UID_MAX); + + r = check_etc_passwd_collisions(directory, NULL, *current_uid); + if (r < 0) + return r; + if (r > 0) /* already used */ + continue; + + /* We want to use the UID also as GID, hence check for it in /etc/group too */ + r = check_etc_group_collisions(directory, NULL, (gid_t) *current_uid); + if (r <= 0) + return r; + } +} + +BindUserContext* bind_user_context_free(BindUserContext *c) { + if (!c) + return NULL; + + assert(c->n_data == 0 || c->data); + + for (size_t i = 0; i < c->n_data; i++) { + user_record_unref(c->data[i].host_user); + group_record_unref(c->data[i].host_group); + user_record_unref(c->data[i].payload_user); + group_record_unref(c->data[i].payload_group); + } + + return mfree(c); +} + +int bind_user_prepare( + const char *directory, + char **bind_user, + uid_t uid_shift, + uid_t uid_range, + CustomMount **custom_mounts, + size_t *n_custom_mounts, + BindUserContext **ret) { + + _cleanup_(bind_user_context_freep) BindUserContext *c = NULL; + uid_t current_uid = MAP_UID_MIN; + int r; + + assert(custom_mounts); + assert(n_custom_mounts); + assert(ret); + + /* This resolves the users specified in 'bind_user', generates a minimalized JSON user + group record + * for it to stick in the container, allocates a UID/GID for it, and updates the custom mount table, + * to include an appropriate bind mount mapping. + * + * This extends the passed custom_mounts/n_custom_mounts with the home directories, and allocates a + * new BindUserContext for the user records */ + + if (strv_isempty(bind_user)) { + *ret = NULL; + return 0; + } + + c = new0(BindUserContext, 1); + if (!c) + return log_oom(); + + STRV_FOREACH(n, bind_user) { + _cleanup_(user_record_unrefp) UserRecord *u = NULL, *cu = NULL; + _cleanup_(group_record_unrefp) GroupRecord *g = NULL, *cg = NULL; + _cleanup_free_ char *sm = NULL, *sd = NULL; + CustomMount *cm; + + r = userdb_by_name(*n, USERDB_DONT_SYNTHESIZE, &u); + if (r < 0) + return log_error_errno(r, "Failed to resolve user '%s': %m", *n); + + /* For now, let's refuse mapping the root/nobody users explicitly. The records we generate + * are strictly additive, nss-systemd is typically placed last in /etc/nsswitch.conf. Thus + * even if we wanted, we couldn't override the root or nobody user records. Note we also + * check for name conflicts in /etc/passwd + /etc/group later on, which would usually filter + * out root/nobody too, hence these checks might appear redundant — but they actually are + * not, as we want to support environments where /etc/passwd and /etc/group are non-existent, + * and the user/group databases fully synthesized at runtime. Moreover, the name of the + * user/group name of the "nobody" account differs between distros, hence a check by numeric + * UID is safer. */ + if (u->uid == 0 || streq(u->user_name, "root")) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Mapping 'root' user not supported, sorry."); + if (u->uid == UID_NOBODY || STR_IN_SET(u->user_name, NOBODY_USER_NAME, "nobody")) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Mapping 'nobody' user not supported, sorry."); + + if (u->uid >= uid_shift && u->uid < uid_shift + uid_range) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "UID of user '%s' to map is already in container UID range, refusing.", u->user_name); + + r = groupdb_by_gid(u->gid, USERDB_DONT_SYNTHESIZE, &g); + if (r < 0) + return log_error_errno(r, "Failed to resolve group of user '%s': %m", u->user_name); + + if (g->gid >= uid_shift && g->gid < uid_shift + uid_range) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "GID of group '%s' to map is already in container GID range, refusing.", g->group_name); + + /* We want to synthesize exactly one user + group from the host into the container. This only + * makes sense if the user on the host has its own private group. We can't reasonably check + * this, so we just check of the name of user and group match. + * + * One of these days we might want to support users in a shared/common group too, but it's + * not clear to me how this would have to be mapped, precisely given that the common group + * probably already exists in the container. */ + if (!streq(u->user_name, g->group_name)) + return log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), + "Sorry, mapping users without private groups is currently not supported."); + + r = find_free_uid(directory, uid_range, ¤t_uid); + if (r < 0) + return r; + + r = convert_user(directory, u, g, current_uid, &cu, &cg); + if (r < 0) + return r; + + if (!GREEDY_REALLOC(c->data, c->n_data + 1)) + return log_oom(); + + sm = strdup(u->home_directory); + if (!sm) + return log_oom(); + + sd = strdup(cu->home_directory); + if (!sd) + return log_oom(); + + cm = reallocarray(*custom_mounts, *n_custom_mounts + 1, sizeof(CustomMount)); + if (!cm) + return log_oom(); + + *custom_mounts = cm; + + (*custom_mounts)[(*n_custom_mounts)++] = (CustomMount) { + .type = CUSTOM_MOUNT_BIND, + .source = TAKE_PTR(sm), + .destination = TAKE_PTR(sd), + }; + + c->data[c->n_data++] = (BindUserData) { + .host_user = TAKE_PTR(u), + .host_group = TAKE_PTR(g), + .payload_user = TAKE_PTR(cu), + .payload_group = TAKE_PTR(cg), + }; + + current_uid++; + } + + *ret = TAKE_PTR(c); + return 1; +} + +static int write_and_symlink( + const char *root, + JsonVariant *v, + const char *name, + uid_t uid, + const char *suffix, + WriteStringFileFlags extra_flags) { + + _cleanup_free_ char *j = NULL, *f = NULL, *p = NULL, *q = NULL; + int r; + + assert(root); + assert(v); + assert(name); + assert(uid_is_valid(uid)); + assert(suffix); + + r = json_variant_format(v, JSON_FORMAT_NEWLINE, &j); + if (r < 0) + return log_error_errno(r, "Failed to format user record JSON: %m"); + + f = strjoin(name, suffix); + if (!f) + return log_oom(); + + p = path_join(root, "/run/host/userdb/", f); + if (!p) + return log_oom(); + + if (asprintf(&q, "%s/run/host/userdb/" UID_FMT "%s", root, uid, suffix) < 0) + return log_oom(); + + if (symlink(f, q) < 0) + return log_error_errno(errno, "Failed to create symlink '%s': %m", q); + + r = userns_lchown(q, 0, 0); + if (r < 0) + return log_error_errno(r, "Failed to adjust access mode of '%s': %m", q); + + r = write_string_file(p, j, WRITE_STRING_FILE_CREATE|extra_flags); + if (r < 0) + return log_error_errno(r, "Failed to write %s: %m", p); + + r = userns_lchown(p, 0, 0); + if (r < 0) + return log_error_errno(r, "Failed to adjust access mode of '%s': %m", p); + + return 0; +} + +int bind_user_setup( + const BindUserContext *c, + const char *root) { + + static const UserRecordLoadFlags strip_flags = /* Removes privileged info */ + USER_RECORD_REQUIRE_REGULAR| + USER_RECORD_STRIP_PRIVILEGED| + USER_RECORD_ALLOW_PER_MACHINE| + USER_RECORD_ALLOW_BINDING| + USER_RECORD_ALLOW_SIGNATURE| + USER_RECORD_PERMISSIVE; + static const UserRecordLoadFlags shadow_flags = /* Extracts privileged info */ + USER_RECORD_STRIP_REGULAR| + USER_RECORD_ALLOW_PRIVILEGED| + USER_RECORD_STRIP_PER_MACHINE| + USER_RECORD_STRIP_BINDING| + USER_RECORD_STRIP_SIGNATURE| + USER_RECORD_EMPTY_OK| + USER_RECORD_PERMISSIVE; + int r; + + assert(root); + + if (!c || c->n_data == 0) + return 0; + + r = userns_mkdir(root, "/run/host", 0755, 0, 0); + if (r < 0) + return log_error_errno(r, "Failed to create /run/host: %m"); + + r = userns_mkdir(root, "/run/host/home", 0755, 0, 0); + if (r < 0) + return log_error_errno(r, "Failed to create /run/host/home: %m"); + + r = userns_mkdir(root, "/run/host/userdb", 0755, 0, 0); + if (r < 0) + return log_error_errno(r, "Failed to create /run/host/userdb: %m"); + + for (size_t i = 0; i < c->n_data; i++) { + _cleanup_(group_record_unrefp) GroupRecord *stripped_group = NULL, *shadow_group = NULL; + _cleanup_(user_record_unrefp) UserRecord *stripped_user = NULL, *shadow_user = NULL; + const BindUserData *d = c->data + i; + + /* First, write shadow (i.e. privileged) data for group record */ + r = group_record_clone(d->payload_group, shadow_flags, &shadow_group); + if (r < 0) + return log_error_errno(r, "Failed to extract privileged information from group record: %m"); + + if (!json_variant_is_blank_object(shadow_group->json)) { + r = write_and_symlink( + root, + shadow_group->json, + d->payload_group->group_name, + d->payload_group->gid, + ".group-privileged", + WRITE_STRING_FILE_MODE_0600); + if (r < 0) + return r; + } + + /* Second, write main part of group record. */ + r = group_record_clone(d->payload_group, strip_flags, &stripped_group); + if (r < 0) + return log_error_errno(r, "Failed to strip privileged information from group record: %m"); + + r = write_and_symlink( + root, + stripped_group->json, + d->payload_group->group_name, + d->payload_group->gid, + ".group", + 0); + if (r < 0) + return r; + + /* Third, write out user shadow data. i.e. extract privileged info from user record */ + r = user_record_clone(d->payload_user, shadow_flags, &shadow_user); + if (r < 0) + return log_error_errno(r, "Failed to extract privileged information from user record: %m"); + + if (!json_variant_is_blank_object(shadow_user->json)) { + r = write_and_symlink( + root, + shadow_user->json, + d->payload_user->user_name, + d->payload_user->uid, + ".user-privileged", + WRITE_STRING_FILE_MODE_0600); + if (r < 0) + return r; + } + + /* Finally write out the main part of the user record */ + r = user_record_clone(d->payload_user, strip_flags, &stripped_user); + if (r < 0) + return log_error_errno(r, "Failed to strip privileged information from user record: %m"); + + r = write_and_symlink( + root, + stripped_user->json, + d->payload_user->user_name, + d->payload_user->uid, + ".user", + 0); + if (r < 0) + return r; + } + + return 1; +} diff --git a/src/nspawn/nspawn-bind-user.h b/src/nspawn/nspawn-bind-user.h new file mode 100644 index 0000000..4352ce0 --- /dev/null +++ b/src/nspawn/nspawn-bind-user.h @@ -0,0 +1,29 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ +#pragma once + +#include "user-record.h" +#include "group-record.h" +#include "nspawn-mount.h" + +typedef struct BindUserData { + /* The host's user/group records */ + UserRecord *host_user; + GroupRecord *host_group; + + /* The mapped records to place into the container */ + UserRecord *payload_user; + GroupRecord *payload_group; +} BindUserData; + +typedef struct BindUserContext { + BindUserData *data; + size_t n_data; +} BindUserContext; + +BindUserContext* bind_user_context_free(BindUserContext *c); + +DEFINE_TRIVIAL_CLEANUP_FUNC(BindUserContext*, bind_user_context_free); + +int bind_user_prepare(const char *directory, char **bind_user, uid_t uid_shift, uid_t uid_range, CustomMount **custom_mounts, size_t *n_custom_mounts, BindUserContext **ret); + +int bind_user_setup(const BindUserContext *c, const char *root); diff --git a/src/nspawn/nspawn-cgroup.c b/src/nspawn/nspawn-cgroup.c new file mode 100644 index 0000000..6c47ab6 --- /dev/null +++ b/src/nspawn/nspawn-cgroup.c @@ -0,0 +1,606 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include <sys/mount.h> + +#include "alloc-util.h" +#include "cgroup-setup.h" +#include "fd-util.h" +#include "fileio.h" +#include "format-util.h" +#include "fs-util.h" +#include "mkdir.h" +#include "mount-util.h" +#include "mountpoint-util.h" +#include "nspawn-cgroup.h" +#include "nspawn-mount.h" +#include "path-util.h" +#include "rm-rf.h" +#include "string-util.h" +#include "strv.h" +#include "user-util.h" +#include "util.h" + +static int chown_cgroup_path(const char *path, uid_t uid_shift) { + _cleanup_close_ int fd = -1; + + fd = open(path, O_RDONLY|O_CLOEXEC|O_DIRECTORY); + if (fd < 0) + return -errno; + + FOREACH_STRING(fn, + ".", + "cgroup.clone_children", + "cgroup.controllers", + "cgroup.events", + "cgroup.procs", + "cgroup.stat", + "cgroup.subtree_control", + "cgroup.threads", + "memory.oom.group", + "memory.reclaim", + "notify_on_release", + "tasks") + if (fchownat(fd, fn, uid_shift, uid_shift, 0) < 0) + log_full_errno(errno == ENOENT ? LOG_DEBUG : LOG_WARNING, errno, + "Failed to chown \"%s/%s\", ignoring: %m", path, fn); + + return 0; +} + +int chown_cgroup(pid_t pid, CGroupUnified unified_requested, uid_t uid_shift) { + _cleanup_free_ char *path = NULL, *fs = NULL; + int r; + + r = cg_pid_get_path(NULL, pid, &path); + if (r < 0) + return log_error_errno(r, "Failed to get container cgroup path: %m"); + + r = cg_get_path(SYSTEMD_CGROUP_CONTROLLER, path, NULL, &fs); + if (r < 0) + return log_error_errno(r, "Failed to get file system path for container cgroup: %m"); + + r = chown_cgroup_path(fs, uid_shift); + if (r < 0) + return log_error_errno(r, "Failed to chown() cgroup %s: %m", fs); + + if (unified_requested == CGROUP_UNIFIED_SYSTEMD || (unified_requested == CGROUP_UNIFIED_NONE && cg_unified_controller(SYSTEMD_CGROUP_CONTROLLER) > 0)) { + _cleanup_free_ char *lfs = NULL; + /* Always propagate access rights from unified to legacy controller */ + + r = cg_get_path(SYSTEMD_CGROUP_CONTROLLER_LEGACY, path, NULL, &lfs); + if (r < 0) + return log_error_errno(r, "Failed to get file system path for container cgroup: %m"); + + r = chown_cgroup_path(lfs, uid_shift); + if (r < 0) + return log_error_errno(r, "Failed to chown() cgroup %s: %m", lfs); + } + + return 0; +} + +int sync_cgroup(pid_t pid, CGroupUnified unified_requested, uid_t uid_shift) { + _cleanup_free_ char *cgroup = NULL; + char tree[] = "/tmp/unifiedXXXXXX", pid_string[DECIMAL_STR_MAX(pid) + 1]; + bool undo_mount = false; + const char *fn; + int r, unified_controller; + + unified_controller = cg_unified_controller(SYSTEMD_CGROUP_CONTROLLER); + if (unified_controller < 0) + return log_error_errno(unified_controller, "Failed to determine whether the systemd hierarchy is unified: %m"); + if ((unified_controller > 0) == (unified_requested >= CGROUP_UNIFIED_SYSTEMD)) + return 0; + + /* When the host uses the legacy cgroup setup, but the + * container shall use the unified hierarchy, let's make sure + * we copy the path from the name=systemd hierarchy into the + * unified hierarchy. Similar for the reverse situation. */ + + r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, pid, &cgroup); + if (r < 0) + return log_error_errno(r, "Failed to get control group of " PID_FMT ": %m", pid); + + /* In order to access the unified hierarchy we need to mount it */ + if (!mkdtemp(tree)) + return log_error_errno(errno, "Failed to generate temporary mount point for unified hierarchy: %m"); + + if (unified_controller > 0) + r = mount_nofollow_verbose(LOG_ERR, "cgroup", tree, "cgroup", + MS_NOSUID|MS_NOEXEC|MS_NODEV, "none,name=systemd,xattr"); + else + r = mount_nofollow_verbose(LOG_ERR, "cgroup", tree, "cgroup2", + MS_NOSUID|MS_NOEXEC|MS_NODEV, NULL); + if (r < 0) + goto finish; + + undo_mount = true; + + /* If nspawn dies abruptly the cgroup hierarchy created below + * its unit isn't cleaned up. So, let's remove it + * https://github.com/systemd/systemd/pull/4223#issuecomment-252519810 */ + fn = strjoina(tree, cgroup); + (void) rm_rf(fn, REMOVE_ROOT|REMOVE_ONLY_DIRECTORIES); + + fn = strjoina(tree, cgroup, "/cgroup.procs"); + + sprintf(pid_string, PID_FMT, pid); + r = write_string_file(fn, pid_string, WRITE_STRING_FILE_DISABLE_BUFFER|WRITE_STRING_FILE_MKDIR_0755); + if (r < 0) { + log_error_errno(r, "Failed to move process: %m"); + goto finish; + } + + fn = strjoina(tree, cgroup); + r = chown_cgroup_path(fn, uid_shift); + if (r < 0) + log_error_errno(r, "Failed to chown() cgroup %s: %m", fn); +finish: + if (undo_mount) + (void) umount_verbose(LOG_ERR, tree, UMOUNT_NOFOLLOW); + + (void) rmdir(tree); + return r; +} + +int create_subcgroup(pid_t pid, bool keep_unit, CGroupUnified unified_requested) { + _cleanup_free_ char *cgroup = NULL; + CGroupMask supported; + const char *payload; + int r; + + assert(pid > 1); + + /* In the unified hierarchy inner nodes may only contain subgroups, but not processes. Hence, if we running in + * the unified hierarchy and the container does the same, and we did not create a scope unit for the container + * move us and the container into two separate subcgroups. + * + * Moreover, container payloads such as systemd try to manage the cgroup they run in full (i.e. including + * its attributes), while the host systemd will only delegate cgroups for children of the cgroup created for a + * delegation unit, instead of the cgroup itself. This means, if we'd pass on the cgroup allocated from the + * host systemd directly to the payload, the host and payload systemd might fight for the cgroup + * attributes. Hence, let's insert an intermediary cgroup to cover that case too. + * + * Note that we only bother with the main hierarchy here, not with any secondary ones. On the unified setup + * that's fine because there's only one hierarchy anyway and controllers are enabled directly on it. On the + * legacy setup, this is fine too, since delegation of controllers is generally not safe there, hence we won't + * do it. */ + + r = cg_mask_supported(&supported); + if (r < 0) + return log_error_errno(r, "Failed to determine supported controllers: %m"); + + if (keep_unit) + r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, 0, &cgroup); + else + r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, pid, &cgroup); + if (r < 0) + return log_error_errno(r, "Failed to get our control group: %m"); + + payload = strjoina(cgroup, "/payload"); + r = cg_create_and_attach(SYSTEMD_CGROUP_CONTROLLER, payload, pid); + if (r < 0) + return log_error_errno(r, "Failed to create %s subcgroup: %m", payload); + + if (keep_unit) { + const char *supervisor; + + supervisor = strjoina(cgroup, "/supervisor"); + r = cg_create_and_attach(SYSTEMD_CGROUP_CONTROLLER, supervisor, 0); + if (r < 0) + return log_error_errno(r, "Failed to create %s subcgroup: %m", supervisor); + } + + /* Try to enable as many controllers as possible for the new payload. */ + (void) cg_enable_everywhere(supported, supported, cgroup, NULL); + return 0; +} + +/* Retrieve existing subsystems. This function is called in a new cgroup + * namespace. + */ +static int get_process_controllers(Set **ret) { + _cleanup_set_free_ Set *controllers = NULL; + _cleanup_fclose_ FILE *f = NULL; + int r; + + assert(ret); + + f = fopen("/proc/self/cgroup", "re"); + if (!f) + return errno == ENOENT ? -ESRCH : -errno; + + for (;;) { + _cleanup_free_ char *line = NULL; + char *e, *l; + + r = read_line(f, LONG_LINE_MAX, &line); + if (r < 0) + return r; + if (r == 0) + break; + + l = strchr(line, ':'); + if (!l) + continue; + + l++; + e = strchr(l, ':'); + if (!e) + continue; + + *e = 0; + + if (STR_IN_SET(l, "", "name=systemd", "name=unified")) + continue; + + r = set_put_strdup(&controllers, l); + if (r < 0) + return r; + } + + *ret = TAKE_PTR(controllers); + + return 0; +} + +static int mount_legacy_cgroup_hierarchy( + const char *dest, + const char *controller, + const char *hierarchy, + bool read_only) { + + const char *to, *fstype, *opts; + int r; + + to = strjoina(strempty(dest), "/sys/fs/cgroup/", hierarchy); + + r = path_is_mount_point(to, dest, 0); + if (r < 0 && r != -ENOENT) + return log_error_errno(r, "Failed to determine if %s is mounted already: %m", to); + if (r > 0) + return 0; + + (void) mkdir_p(to, 0755); + + /* The superblock mount options of the mount point need to be + * identical to the hosts', and hence writable... */ + if (streq(controller, SYSTEMD_CGROUP_CONTROLLER_HYBRID)) { + fstype = "cgroup2"; + opts = NULL; + } else if (streq(controller, SYSTEMD_CGROUP_CONTROLLER_LEGACY)) { + fstype = "cgroup"; + opts = "none,name=systemd,xattr"; + } else { + fstype = "cgroup"; + opts = controller; + } + + r = mount_nofollow_verbose(LOG_ERR, "cgroup", to, fstype, MS_NOSUID|MS_NOEXEC|MS_NODEV, opts); + if (r < 0) + return r; + + /* ... hence let's only make the bind mount read-only, not the superblock. */ + if (read_only) { + r = mount_nofollow_verbose(LOG_ERR, NULL, to, NULL, + MS_BIND|MS_REMOUNT|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_RDONLY, NULL); + if (r < 0) + return r; + } + + return 1; +} + +/* Mount a legacy cgroup hierarchy when cgroup namespaces are supported. */ +static int mount_legacy_cgns_supported( + const char *dest, + CGroupUnified unified_requested, + bool userns, + uid_t uid_shift, + uid_t uid_range, + const char *selinux_apifs_context) { + + _cleanup_set_free_ Set *controllers = NULL; + const char *cgroup_root = "/sys/fs/cgroup", *c; + int r; + + (void) mkdir_p(cgroup_root, 0755); + + /* Mount a tmpfs to /sys/fs/cgroup if it's not mounted there yet. */ + r = path_is_mount_point(cgroup_root, dest, AT_SYMLINK_FOLLOW); + if (r < 0) + return log_error_errno(r, "Failed to determine if /sys/fs/cgroup is already mounted: %m"); + if (r == 0) { + _cleanup_free_ char *options = NULL; + + /* When cgroup namespaces are enabled and user namespaces are + * used then the mount of the cgroupfs is done *inside* the new + * user namespace. We're root in the new user namespace and the + * kernel will happily translate our uid/gid to the correct + * uid/gid as seen from e.g. /proc/1/mountinfo. So we simply + * pass uid 0 and not uid_shift to tmpfs_patch_options(). + */ + r = tmpfs_patch_options("mode=755" TMPFS_LIMITS_SYS_FS_CGROUP, 0, selinux_apifs_context, &options); + if (r < 0) + return log_oom(); + + r = mount_nofollow_verbose(LOG_ERR, "tmpfs", cgroup_root, "tmpfs", + MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_STRICTATIME, options); + if (r < 0) + return r; + } + + r = cg_all_unified(); + if (r < 0) + return r; + if (r > 0) + goto skip_controllers; + + r = get_process_controllers(&controllers); + if (r < 0) + return log_error_errno(r, "Failed to determine cgroup controllers: %m"); + + for (;;) { + _cleanup_free_ const char *controller = NULL; + + controller = set_steal_first(controllers); + if (!controller) + break; + + r = mount_legacy_cgroup_hierarchy("", controller, controller, !userns); + if (r < 0) + return r; + + /* When multiple hierarchies are co-mounted, make their + * constituting individual hierarchies a symlink to the + * co-mount. + */ + c = controller; + for (;;) { + _cleanup_free_ char *target = NULL, *tok = NULL; + + r = extract_first_word(&c, &tok, ",", 0); + if (r < 0) + return log_error_errno(r, "Failed to extract co-mounted cgroup controller: %m"); + if (r == 0) + break; + + if (streq(controller, tok)) + break; + + target = path_join("/sys/fs/cgroup/", tok); + if (!target) + return log_oom(); + + r = symlink_idempotent(controller, target, false); + if (r == -EINVAL) + return log_error_errno(r, "Invalid existing symlink for combined hierarchy: %m"); + if (r < 0) + return log_error_errno(r, "Failed to create symlink for combined hierarchy: %m"); + } + } + +skip_controllers: + if (unified_requested >= CGROUP_UNIFIED_SYSTEMD) { + r = mount_legacy_cgroup_hierarchy("", SYSTEMD_CGROUP_CONTROLLER_HYBRID, "unified", false); + if (r < 0) + return r; + } + + r = mount_legacy_cgroup_hierarchy("", SYSTEMD_CGROUP_CONTROLLER_LEGACY, "systemd", false); + if (r < 0) + return r; + + if (!userns) + return mount_nofollow_verbose(LOG_ERR, NULL, cgroup_root, NULL, + MS_REMOUNT|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_STRICTATIME|MS_RDONLY, "mode=755"); + + return 0; +} + +/* Mount legacy cgroup hierarchy when cgroup namespaces are unsupported. */ +static int mount_legacy_cgns_unsupported( + const char *dest, + CGroupUnified unified_requested, + bool userns, + uid_t uid_shift, + uid_t uid_range, + const char *selinux_apifs_context) { + + _cleanup_set_free_ Set *controllers = NULL; + const char *cgroup_root; + int r; + + cgroup_root = prefix_roota(dest, "/sys/fs/cgroup"); + + (void) mkdir_p(cgroup_root, 0755); + + /* Mount a tmpfs to /sys/fs/cgroup if it's not mounted there yet. */ + r = path_is_mount_point(cgroup_root, dest, AT_SYMLINK_FOLLOW); + if (r < 0) + return log_error_errno(r, "Failed to determine if /sys/fs/cgroup is already mounted: %m"); + if (r == 0) { + _cleanup_free_ char *options = NULL; + + r = tmpfs_patch_options("mode=755" TMPFS_LIMITS_SYS_FS_CGROUP, uid_shift == 0 ? UID_INVALID : uid_shift, selinux_apifs_context, &options); + if (r < 0) + return log_oom(); + + r = mount_nofollow_verbose(LOG_ERR, "tmpfs", cgroup_root, "tmpfs", + MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_STRICTATIME, options); + if (r < 0) + return r; + } + + r = cg_all_unified(); + if (r < 0) + return r; + if (r > 0) + goto skip_controllers; + + r = cg_kernel_controllers(&controllers); + if (r < 0) + return log_error_errno(r, "Failed to determine cgroup controllers: %m"); + + for (;;) { + _cleanup_free_ char *controller = NULL, *origin = NULL, *combined = NULL; + + controller = set_steal_first(controllers); + if (!controller) + break; + + origin = path_join("/sys/fs/cgroup/", controller); + if (!origin) + return log_oom(); + + r = readlink_malloc(origin, &combined); + if (r == -EINVAL) { + /* Not a symbolic link, but directly a single cgroup hierarchy */ + + r = mount_legacy_cgroup_hierarchy(dest, controller, controller, true); + if (r < 0) + return r; + + } else if (r < 0) + return log_error_errno(r, "Failed to read link %s: %m", origin); + else { + _cleanup_free_ char *target = NULL; + + target = path_join(dest, origin); + if (!target) + return log_oom(); + + /* A symbolic link, a combination of controllers in one hierarchy */ + + if (!filename_is_valid(combined)) { + log_warning("Ignoring invalid combined hierarchy %s.", combined); + continue; + } + + r = mount_legacy_cgroup_hierarchy(dest, combined, combined, true); + if (r < 0) + return r; + + r = symlink_idempotent(combined, target, false); + if (r == -EINVAL) + return log_error_errno(r, "Invalid existing symlink for combined hierarchy: %m"); + if (r < 0) + return log_error_errno(r, "Failed to create symlink for combined hierarchy: %m"); + } + } + +skip_controllers: + if (unified_requested >= CGROUP_UNIFIED_SYSTEMD) { + r = mount_legacy_cgroup_hierarchy(dest, SYSTEMD_CGROUP_CONTROLLER_HYBRID, "unified", false); + if (r < 0) + return r; + } + + r = mount_legacy_cgroup_hierarchy(dest, SYSTEMD_CGROUP_CONTROLLER_LEGACY, "systemd", false); + if (r < 0) + return r; + + return mount_nofollow_verbose(LOG_ERR, NULL, cgroup_root, NULL, + MS_REMOUNT|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_STRICTATIME|MS_RDONLY, "mode=755"); +} + +static int mount_unified_cgroups(const char *dest) { + const char *p; + int r; + + assert(dest); + + p = prefix_roota(dest, "/sys/fs/cgroup"); + + (void) mkdir_p(p, 0755); + + r = path_is_mount_point(p, dest, AT_SYMLINK_FOLLOW); + if (r < 0) + return log_error_errno(r, "Failed to determine if %s is mounted already: %m", p); + if (r > 0) { + p = prefix_roota(dest, "/sys/fs/cgroup/cgroup.procs"); + if (access(p, F_OK) >= 0) + return 0; + if (errno != ENOENT) + return log_error_errno(errno, "Failed to determine if mount point %s contains the unified cgroup hierarchy: %m", p); + + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), + "%s is already mounted but not a unified cgroup hierarchy. Refusing.", p); + } + + return mount_nofollow_verbose(LOG_ERR, "cgroup", p, "cgroup2", MS_NOSUID|MS_NOEXEC|MS_NODEV, NULL); +} + +int mount_cgroups( + const char *dest, + CGroupUnified unified_requested, + bool userns, + uid_t uid_shift, + uid_t uid_range, + const char *selinux_apifs_context, + bool use_cgns) { + + if (unified_requested >= CGROUP_UNIFIED_ALL) + return mount_unified_cgroups(dest); + if (use_cgns) + return mount_legacy_cgns_supported(dest, unified_requested, userns, uid_shift, uid_range, selinux_apifs_context); + + return mount_legacy_cgns_unsupported(dest, unified_requested, userns, uid_shift, uid_range, selinux_apifs_context); +} + +static int mount_systemd_cgroup_writable_one(const char *root, const char *own) { + int r; + + assert(root); + assert(own); + + /* Make our own cgroup a (writable) bind mount */ + r = mount_nofollow_verbose(LOG_ERR, own, own, NULL, MS_BIND, NULL); + if (r < 0) + return r; + + /* And then remount the systemd cgroup root read-only */ + return mount_nofollow_verbose(LOG_ERR, NULL, root, NULL, + MS_BIND|MS_REMOUNT|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_RDONLY, NULL); +} + +int mount_systemd_cgroup_writable( + const char *dest, + CGroupUnified unified_requested) { + + _cleanup_free_ char *own_cgroup_path = NULL; + const char *root, *own; + int r; + + assert(dest); + + r = cg_pid_get_path(NULL, 0, &own_cgroup_path); + if (r < 0) + return log_error_errno(r, "Failed to determine our own cgroup path: %m"); + + /* If we are living in the top-level, then there's nothing to do... */ + if (path_equal(own_cgroup_path, "/")) + return 0; + + if (unified_requested >= CGROUP_UNIFIED_ALL) { + + root = prefix_roota(dest, "/sys/fs/cgroup"); + own = strjoina(root, own_cgroup_path); + + } else { + + if (unified_requested >= CGROUP_UNIFIED_SYSTEMD) { + root = prefix_roota(dest, "/sys/fs/cgroup/unified"); + own = strjoina(root, own_cgroup_path); + + r = mount_systemd_cgroup_writable_one(root, own); + if (r < 0) + return r; + } + + root = prefix_roota(dest, "/sys/fs/cgroup/systemd"); + own = strjoina(root, own_cgroup_path); + } + + return mount_systemd_cgroup_writable_one(root, own); +} diff --git a/src/nspawn/nspawn-cgroup.h b/src/nspawn/nspawn-cgroup.h new file mode 100644 index 0000000..3f5ba62 --- /dev/null +++ b/src/nspawn/nspawn-cgroup.h @@ -0,0 +1,14 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ +#pragma once + +#include <stdbool.h> +#include <sys/types.h> + +#include "cgroup-util.h" + +int chown_cgroup(pid_t pid, CGroupUnified unified_requested, uid_t uid_shift); +int sync_cgroup(pid_t pid, CGroupUnified unified_requested, uid_t uid_shift); +int create_subcgroup(pid_t pid, bool keep_unit, CGroupUnified unified_requested); + +int mount_cgroups(const char *dest, CGroupUnified unified_requested, bool userns, uid_t uid_shift, uid_t uid_range, const char *selinux_apifs_context, bool use_cgns); +int mount_systemd_cgroup_writable(const char *dest, CGroupUnified unified_requested); diff --git a/src/nspawn/nspawn-creds.c b/src/nspawn/nspawn-creds.c new file mode 100644 index 0000000..0900d8c --- /dev/null +++ b/src/nspawn/nspawn-creds.c @@ -0,0 +1,25 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include "alloc-util.h" +#include "macro.h" +#include "memory-util.h" +#include "nspawn-creds.h" + +static void credential_free(Credential *cred) { + assert(cred); + + cred->id = mfree(cred->id); + cred->data = erase_and_free(cred->data); + cred->size = 0; +} + +void credential_free_all(Credential *creds, size_t n) { + size_t i; + + assert(creds || n == 0); + + for (i = 0; i < n; i++) + credential_free(creds + i); + + free(creds); +} diff --git a/src/nspawn/nspawn-creds.h b/src/nspawn/nspawn-creds.h new file mode 100644 index 0000000..de0661b --- /dev/null +++ b/src/nspawn/nspawn-creds.h @@ -0,0 +1,12 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ +#pragma once + +#include <sys/types.h> + +typedef struct Credential { + char *id; + void *data; + size_t size; +} Credential; + +void credential_free_all(Credential *creds, size_t n); diff --git a/src/nspawn/nspawn-def.h b/src/nspawn/nspawn-def.h new file mode 100644 index 0000000..32a20aa --- /dev/null +++ b/src/nspawn/nspawn-def.h @@ -0,0 +1,9 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ +#pragma once + +#include <sys/types.h> + +/* While we are chmod()ing a directory tree, we set the top-level UID base to this "busy" base, so that we can always + * recognize trees we are were chmod()ing recursively and got interrupted in */ +#define UID_BUSY_BASE ((uid_t) UINT32_C(0xFFFE0000)) +#define UID_BUSY_MASK ((uid_t) UINT32_C(0xFFFF0000)) diff --git a/src/nspawn/nspawn-expose-ports.c b/src/nspawn/nspawn-expose-ports.c new file mode 100644 index 0000000..bb54f8c --- /dev/null +++ b/src/nspawn/nspawn-expose-ports.c @@ -0,0 +1,220 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include "sd-netlink.h" + +#include "af-list.h" +#include "alloc-util.h" +#include "fd-util.h" +#include "firewall-util.h" +#include "in-addr-util.h" +#include "local-addresses.h" +#include "netlink-util.h" +#include "nspawn-expose-ports.h" +#include "parse-util.h" +#include "socket-util.h" +#include "string-util.h" +#include "util.h" + +int expose_port_parse(ExposePort **l, const char *s) { + const char *split, *e; + uint16_t container_port, host_port; + ExposePort *port; + int protocol; + int r; + + assert(l); + assert(s); + + if ((e = startswith(s, "tcp:"))) + protocol = IPPROTO_TCP; + else if ((e = startswith(s, "udp:"))) + protocol = IPPROTO_UDP; + else { + e = s; + protocol = IPPROTO_TCP; + } + + split = strchr(e, ':'); + if (split) { + char v[split - e + 1]; + + memcpy(v, e, split - e); + v[split - e] = 0; + + r = parse_ip_port(v, &host_port); + if (r < 0) + return -EINVAL; + + r = parse_ip_port(split + 1, &container_port); + } else { + r = parse_ip_port(e, &container_port); + host_port = container_port; + } + + if (r < 0) + return r; + + LIST_FOREACH(ports, p, *l) + if (p->protocol == protocol && p->host_port == host_port) + return -EEXIST; + + port = new(ExposePort, 1); + if (!port) + return -ENOMEM; + + *port = (ExposePort) { + .protocol = protocol, + .host_port = host_port, + .container_port = container_port, + }; + + LIST_PREPEND(ports, *l, port); + + return 0; +} + +void expose_port_free_all(ExposePort *p) { + + while (p) { + ExposePort *q = p; + LIST_REMOVE(ports, p, q); + free(q); + } +} + +int expose_port_flush(FirewallContext **fw_ctx, ExposePort* l, int af, union in_addr_union *exposed) { + int r; + + assert(exposed); + + if (!l) + return 0; + + if (!in_addr_is_set(af, exposed)) + return 0; + + log_debug("Lost IP address."); + + LIST_FOREACH(ports, p, l) { + r = fw_add_local_dnat(fw_ctx, + false, + af, + p->protocol, + p->host_port, + exposed, + p->container_port, + NULL); + if (r < 0) + log_warning_errno(r, "Failed to modify %s firewall: %m", af_to_name(af)); + } + + *exposed = IN_ADDR_NULL; + return 0; +} + +int expose_port_execute(sd_netlink *rtnl, FirewallContext **fw_ctx, ExposePort *l, int af, union in_addr_union *exposed) { + _cleanup_free_ struct local_address *addresses = NULL; + union in_addr_union new_exposed; + bool add; + int r; + + assert(exposed); + + /* Invoked each time an address is added or removed inside the + * container */ + + if (!l) + return 0; + + r = local_addresses(rtnl, 0, af, &addresses); + if (r < 0) + return log_error_errno(r, "Failed to enumerate local addresses: %m"); + + add = r > 0 && + addresses[0].family == af && + addresses[0].scope < RT_SCOPE_LINK; + + if (!add) + return expose_port_flush(fw_ctx, l, af, exposed); + + new_exposed = addresses[0].address; + if (in_addr_equal(af, exposed, &new_exposed)) + return 0; + + log_debug("New container IP is %s.", IN_ADDR_TO_STRING(af, &new_exposed)); + + LIST_FOREACH(ports, p, l) { + r = fw_add_local_dnat(fw_ctx, + true, + af, + p->protocol, + p->host_port, + &new_exposed, + p->container_port, + in_addr_is_set(af, exposed) ? exposed : NULL); + if (r < 0) + log_warning_errno(r, "Failed to modify %s firewall: %m", af_to_name(af)); + } + + *exposed = new_exposed; + return 0; +} + +int expose_port_send_rtnl(int send_fd) { + _cleanup_close_ int fd = -1; + int r; + + assert(send_fd >= 0); + + fd = socket(AF_NETLINK, SOCK_RAW|SOCK_CLOEXEC|SOCK_NONBLOCK, NETLINK_ROUTE); + if (fd < 0) + return log_error_errno(errno, "Failed to allocate container netlink: %m"); + + /* Store away the fd in the socket, so that it stays open as + * long as we run the child */ + r = send_one_fd(send_fd, fd, 0); + if (r < 0) + return log_error_errno(r, "Failed to send netlink fd: %m"); + + return 0; +} + +int expose_port_watch_rtnl( + sd_event *event, + int recv_fd, + sd_netlink_message_handler_t handler, + void *userdata, + sd_netlink **ret) { + _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL; + int fd, r; + + assert(event); + assert(recv_fd >= 0); + assert(ret); + + fd = receive_one_fd(recv_fd, 0); + if (fd < 0) + return log_error_errno(fd, "Failed to recv netlink fd: %m"); + + r = sd_netlink_open_fd(&rtnl, fd); + if (r < 0) { + safe_close(fd); + return log_error_errno(r, "Failed to create rtnl object: %m"); + } + + r = sd_netlink_add_match(rtnl, NULL, RTM_NEWADDR, handler, NULL, userdata, "nspawn-NEWADDR"); + if (r < 0) + return log_error_errno(r, "Failed to subscribe to RTM_NEWADDR messages: %m"); + + r = sd_netlink_add_match(rtnl, NULL, RTM_DELADDR, handler, NULL, userdata, "nspawn-DELADDR"); + if (r < 0) + return log_error_errno(r, "Failed to subscribe to RTM_DELADDR messages: %m"); + + r = sd_netlink_attach_event(rtnl, event, 0); + if (r < 0) + return log_error_errno(r, "Failed to add to event loop: %m"); + + *ret = TAKE_PTR(rtnl); + + return 0; +} diff --git a/src/nspawn/nspawn-expose-ports.h b/src/nspawn/nspawn-expose-ports.h new file mode 100644 index 0000000..27cfccf --- /dev/null +++ b/src/nspawn/nspawn-expose-ports.h @@ -0,0 +1,27 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ +#pragma once + +#include <inttypes.h> + +#include "sd-event.h" +#include "sd-netlink.h" + +#include "firewall-util.h" +#include "in-addr-util.h" +#include "list.h" + +typedef struct ExposePort { + int protocol; + uint16_t host_port; + uint16_t container_port; + LIST_FIELDS(struct ExposePort, ports); +} ExposePort; + +void expose_port_free_all(ExposePort *p); +int expose_port_parse(ExposePort **l, const char *s); + +int expose_port_watch_rtnl(sd_event *event, int recv_fd, sd_netlink_message_handler_t handler, void *userdata, sd_netlink **ret); +int expose_port_send_rtnl(int send_fd); + +int expose_port_execute(sd_netlink *rtnl, FirewallContext **fw_ctx, ExposePort *l, int af, union in_addr_union *exposed); +int expose_port_flush(FirewallContext **fw_ctx, ExposePort* l, int af, union in_addr_union *exposed); diff --git a/src/nspawn/nspawn-gperf.gperf b/src/nspawn/nspawn-gperf.gperf new file mode 100644 index 0000000..a93b8c3 --- /dev/null +++ b/src/nspawn/nspawn-gperf.gperf @@ -0,0 +1,82 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ +%{ +#if __GNUC__ >= 7 +_Pragma("GCC diagnostic ignored \"-Wimplicit-fallthrough\"") +#endif +#include <stddef.h> +#include "conf-parser.h" +#include "nspawn-settings.h" +#include "nspawn-expose-ports.h" +%} +struct ConfigPerfItem; +%null_strings +%language=ANSI-C +%define slot-name section_and_lvalue +%define hash-function-name nspawn_gperf_hash +%define lookup-function-name nspawn_gperf_lookup +%readonly-tables +%omit-struct-type +%struct-type +%includes +%% +Exec.Boot, config_parse_boot, 0, 0 +Exec.Ephemeral, config_parse_tristate, 0, offsetof(Settings, ephemeral) +Exec.ProcessTwo, config_parse_pid2, 0, 0 +Exec.Parameters, config_parse_strv, 0, offsetof(Settings, parameters) +Exec.Environment, config_parse_strv, 0, offsetof(Settings, environment) +Exec.User, config_parse_string, CONFIG_PARSE_STRING_SAFE, offsetof(Settings, user) +Exec.Capability, config_parse_capability, 0, offsetof(Settings, capability) +Exec.AmbientCapability, config_parse_capability, 0, offsetof(Settings, ambient_capability) +Exec.DropCapability, config_parse_capability, 0, offsetof(Settings, drop_capability) +Exec.KillSignal, config_parse_signal, 0, offsetof(Settings, kill_signal) +Exec.Personality, config_parse_personality, 0, offsetof(Settings, personality) +Exec.MachineID, config_parse_id128, 0, offsetof(Settings, machine_id) +Exec.WorkingDirectory, config_parse_path, 0, offsetof(Settings, working_directory) +Exec.PivotRoot, config_parse_pivot_root, 0, 0 +Exec.PrivateUsers, config_parse_private_users, 0, 0 +Exec.NotifyReady, config_parse_tristate, 0, offsetof(Settings, notify_ready) +Exec.SystemCallFilter, config_parse_syscall_filter, 0, 0 +Exec.LimitCPU, config_parse_rlimit, RLIMIT_CPU, offsetof(Settings, rlimit) +Exec.LimitFSIZE, config_parse_rlimit, RLIMIT_FSIZE, offsetof(Settings, rlimit) +Exec.LimitDATA, config_parse_rlimit, RLIMIT_DATA, offsetof(Settings, rlimit) +Exec.LimitSTACK, config_parse_rlimit, RLIMIT_STACK, offsetof(Settings, rlimit) +Exec.LimitCORE, config_parse_rlimit, RLIMIT_CORE, offsetof(Settings, rlimit) +Exec.LimitRSS, config_parse_rlimit, RLIMIT_RSS, offsetof(Settings, rlimit) +Exec.LimitNOFILE, config_parse_rlimit, RLIMIT_NOFILE, offsetof(Settings, rlimit) +Exec.LimitAS, config_parse_rlimit, RLIMIT_AS, offsetof(Settings, rlimit) +Exec.LimitNPROC, config_parse_rlimit, RLIMIT_NPROC, offsetof(Settings, rlimit) +Exec.LimitMEMLOCK, config_parse_rlimit, RLIMIT_MEMLOCK, offsetof(Settings, rlimit) +Exec.LimitLOCKS, config_parse_rlimit, RLIMIT_LOCKS, offsetof(Settings, rlimit) +Exec.LimitSIGPENDING, config_parse_rlimit, RLIMIT_SIGPENDING, offsetof(Settings, rlimit) +Exec.LimitMSGQUEUE, config_parse_rlimit, RLIMIT_MSGQUEUE, offsetof(Settings, rlimit) +Exec.LimitNICE, config_parse_rlimit, RLIMIT_NICE, offsetof(Settings, rlimit) +Exec.LimitRTPRIO, config_parse_rlimit, RLIMIT_RTPRIO, offsetof(Settings, rlimit) +Exec.LimitRTTIME, config_parse_rlimit, RLIMIT_RTTIME, offsetof(Settings, rlimit) +Exec.Hostname, config_parse_hostname, 0, offsetof(Settings, hostname) +Exec.NoNewPrivileges, config_parse_tristate, 0, offsetof(Settings, no_new_privileges) +Exec.OOMScoreAdjust, config_parse_oom_score_adjust, 0, 0 +Exec.CPUAffinity, config_parse_cpu_affinity, 0, 0 +Exec.ResolvConf, config_parse_resolv_conf, 0, offsetof(Settings, resolv_conf) +Exec.LinkJournal, config_parse_link_journal, 0, 0 +Exec.Timezone, config_parse_timezone, 0, offsetof(Settings, timezone) +Exec.SuppressSync, config_parse_tristate, 0, offsetof(Settings, suppress_sync) +Files.ReadOnly, config_parse_tristate, 0, offsetof(Settings, read_only) +Files.Volatile, config_parse_volatile_mode, 0, offsetof(Settings, volatile_mode) +Files.Bind, config_parse_bind, 0, 0 +Files.BindReadOnly, config_parse_bind, 1, 0 +Files.TemporaryFileSystem, config_parse_tmpfs, 0, 0 +Files.Inaccessible, config_parse_inaccessible, 0, 0 +Files.Overlay, config_parse_overlay, 0, 0 +Files.OverlayReadOnly, config_parse_overlay, 1, 0 +Files.PrivateUsersChown, config_parse_userns_chown, 0, offsetof(Settings, userns_ownership) +Files.PrivateUsersOwnership, config_parse_userns_ownership, 0, offsetof(Settings, userns_ownership) +Files.BindUser, config_parse_bind_user, 0, offsetof(Settings, bind_user) +Network.Private, config_parse_tristate, 0, offsetof(Settings, private_network) +Network.Interface, config_parse_strv, 0, offsetof(Settings, network_interfaces) +Network.MACVLAN, config_parse_strv, 0, offsetof(Settings, network_macvlan) +Network.IPVLAN, config_parse_strv, 0, offsetof(Settings, network_ipvlan) +Network.VirtualEthernet, config_parse_tristate, 0, offsetof(Settings, network_veth) +Network.VirtualEthernetExtra, config_parse_veth_extra, 0, 0 +Network.Bridge, config_parse_ifname, 0, offsetof(Settings, network_bridge) +Network.Zone, config_parse_network_zone, 0, 0 +Network.Port, config_parse_expose_port, 0, 0 diff --git a/src/nspawn/nspawn-mount.c b/src/nspawn/nspawn-mount.c new file mode 100644 index 0000000..63f59fe --- /dev/null +++ b/src/nspawn/nspawn-mount.c @@ -0,0 +1,1338 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include <sys/mount.h> +#include <linux/magic.h> + +#include "alloc-util.h" +#include "chase-symlinks.h" +#include "escape.h" +#include "fd-util.h" +#include "format-util.h" +#include "fs-util.h" +#include "label.h" +#include "mkdir-label.h" +#include "mount-util.h" +#include "mountpoint-util.h" +#include "nspawn-mount.h" +#include "parse-util.h" +#include "path-util.h" +#include "rm-rf.h" +#include "set.h" +#include "sort-util.h" +#include "stat-util.h" +#include "string-util.h" +#include "strv.h" +#include "tmpfile-util.h" +#include "user-util.h" + +CustomMount* custom_mount_add(CustomMount **l, size_t *n, CustomMountType t) { + CustomMount *c, *ret; + + assert(l); + assert(n); + assert(t >= 0); + assert(t < _CUSTOM_MOUNT_TYPE_MAX); + + c = reallocarray(*l, *n + 1, sizeof(CustomMount)); + if (!c) + return NULL; + + *l = c; + ret = *l + *n; + (*n)++; + + *ret = (CustomMount) { + .type = t + }; + + return ret; +} + +void custom_mount_free_all(CustomMount *l, size_t n) { + for (size_t i = 0; i < n; i++) { + CustomMount *m = l + i; + + free(m->source); + free(m->destination); + free(m->options); + + if (m->work_dir) { + (void) rm_rf(m->work_dir, REMOVE_ROOT|REMOVE_PHYSICAL); + free(m->work_dir); + } + + if (m->rm_rf_tmpdir) { + (void) rm_rf(m->rm_rf_tmpdir, REMOVE_ROOT|REMOVE_PHYSICAL); + free(m->rm_rf_tmpdir); + } + + strv_free(m->lower); + free(m->type_argument); + } + + free(l); +} + +static int custom_mount_compare(const CustomMount *a, const CustomMount *b) { + int r; + + r = path_compare(a->destination, b->destination); + if (r != 0) + return r; + + return CMP(a->type, b->type); +} + +static int source_path_parse(const char *p, char **ret) { + assert(p); + assert(ret); + + if (isempty(p)) + return -EINVAL; + + if (*p == '+') { + if (!path_is_absolute(p + 1)) + return -EINVAL; + + char *s = strdup(p); + if (!s) + return -ENOMEM; + + *ret = TAKE_PTR(s); + return 0; + } + + return path_make_absolute_cwd(p, ret); +} + +static int source_path_parse_nullable(const char *p, char **ret) { + assert(p); + assert(ret); + + if (isempty(p)) { + *ret = NULL; + return 0; + } + + return source_path_parse(p, ret); +} + +static char *resolve_source_path(const char *dest, const char *source) { + if (!source) + return NULL; + + if (source[0] == '+') + return path_join(dest, source + 1); + + return strdup(source); +} + +static int allocate_temporary_source(CustomMount *m) { + assert(m); + assert(!m->source); + assert(!m->rm_rf_tmpdir); + + m->rm_rf_tmpdir = strdup("/var/tmp/nspawn-temp-XXXXXX"); + if (!m->rm_rf_tmpdir) + return log_oom(); + + if (!mkdtemp(m->rm_rf_tmpdir)) { + m->rm_rf_tmpdir = mfree(m->rm_rf_tmpdir); + return log_error_errno(errno, "Failed to acquire temporary directory: %m"); + } + + m->source = path_join(m->rm_rf_tmpdir, "src"); + if (!m->source) + return log_oom(); + + if (mkdir(m->source, 0755) < 0) + return log_error_errno(errno, "Failed to create %s: %m", m->source); + + return 0; +} + +int custom_mount_prepare_all(const char *dest, CustomMount *l, size_t n) { + int r; + + /* Prepare all custom mounts. This will make source we know all temporary directories. This is called in the + * parent process, so that we know the temporary directories to remove on exit before we fork off the + * children. */ + + assert(l || n == 0); + + /* Order the custom mounts, and make sure we have a working directory */ + typesafe_qsort(l, n, custom_mount_compare); + + for (size_t i = 0; i < n; i++) { + CustomMount *m = l + i; + + /* /proc we mount in the inner child, i.e. when we acquired CLONE_NEWPID. All other mounts we mount + * already in the outer child, so that the mounts are already established before CLONE_NEWPID and in + * particular CLONE_NEWUSER. This also means any custom mounts below /proc also need to be mounted in + * the inner child, not the outer one. Determine this here. */ + m->in_userns = path_startswith(m->destination, "/proc"); + + if (m->type == CUSTOM_MOUNT_BIND) { + if (m->source) { + char *s; + + s = resolve_source_path(dest, m->source); + if (!s) + return log_oom(); + + free_and_replace(m->source, s); + } else { + /* No source specified? In that case, use a throw-away temporary directory in /var/tmp */ + + r = allocate_temporary_source(m); + if (r < 0) + return r; + } + } + + if (m->type == CUSTOM_MOUNT_OVERLAY) { + STRV_FOREACH(j, m->lower) { + char *s; + + s = resolve_source_path(dest, *j); + if (!s) + return log_oom(); + + free_and_replace(*j, s); + } + + if (m->source) { + char *s; + + s = resolve_source_path(dest, m->source); + if (!s) + return log_oom(); + + free_and_replace(m->source, s); + } else { + r = allocate_temporary_source(m); + if (r < 0) + return r; + } + + if (m->work_dir) { + char *s; + + s = resolve_source_path(dest, m->work_dir); + if (!s) + return log_oom(); + + free_and_replace(m->work_dir, s); + } else { + r = tempfn_random(m->source, NULL, &m->work_dir); + if (r < 0) + return log_error_errno(r, "Failed to acquire working directory: %m"); + } + + (void) mkdir_label(m->work_dir, 0700); + } + } + + return 0; +} + +int bind_mount_parse(CustomMount **l, size_t *n, const char *s, bool read_only) { + _cleanup_free_ char *source = NULL, *destination = NULL, *opts = NULL, *p = NULL; + CustomMount *m; + int r; + + assert(l); + assert(n); + + r = extract_many_words(&s, ":", EXTRACT_DONT_COALESCE_SEPARATORS, &source, &destination, NULL); + if (r < 0) + return r; + if (r == 0) + return -EINVAL; + if (r == 1) { + destination = strdup(source[0] == '+' ? source+1 : source); + if (!destination) + return -ENOMEM; + } + if (r == 2 && !isempty(s)) { + opts = strdup(s); + if (!opts) + return -ENOMEM; + } + + r = source_path_parse_nullable(source, &p); + if (r < 0) + return r; + + if (!path_is_absolute(destination)) + return -EINVAL; + + m = custom_mount_add(l, n, CUSTOM_MOUNT_BIND); + if (!m) + return -ENOMEM; + + m->source = TAKE_PTR(p); + m->destination = TAKE_PTR(destination); + m->read_only = read_only; + m->options = TAKE_PTR(opts); + + return 0; +} + +int tmpfs_mount_parse(CustomMount **l, size_t *n, const char *s) { + _cleanup_free_ char *path = NULL, *opts = NULL; + const char *p = ASSERT_PTR(s); + CustomMount *m; + int r; + + assert(l); + assert(n); + + r = extract_first_word(&p, &path, ":", EXTRACT_DONT_COALESCE_SEPARATORS); + if (r < 0) + return r; + if (r == 0) + return -EINVAL; + + if (isempty(p)) + opts = strdup("mode=0755"); + else + opts = strdup(p); + if (!opts) + return -ENOMEM; + + if (!path_is_absolute(path)) + return -EINVAL; + + m = custom_mount_add(l, n, CUSTOM_MOUNT_TMPFS); + if (!m) + return -ENOMEM; + + m->destination = TAKE_PTR(path); + m->options = TAKE_PTR(opts); + + return 0; +} + +int overlay_mount_parse(CustomMount **l, size_t *n, const char *s, bool read_only) { + _cleanup_free_ char *upper = NULL, *destination = NULL; + _cleanup_strv_free_ char **lower = NULL; + CustomMount *m; + int r, k; + + k = strv_split_full(&lower, s, ":", EXTRACT_DONT_COALESCE_SEPARATORS); + if (k < 0) + return k; + if (k < 2) + return -EADDRNOTAVAIL; + if (k == 2) { + _cleanup_free_ char *p = NULL; + + /* If two parameters are specified, the first one is the lower, the second one the upper directory. And + * we'll also define the destination mount point the same as the upper. */ + + r = source_path_parse(lower[0], &p); + if (r < 0) + return r; + + free_and_replace(lower[0], p); + + r = source_path_parse(lower[1], &p); + if (r < 0) + return r; + + free_and_replace(lower[1], p); + + upper = TAKE_PTR(lower[1]); + + destination = strdup(upper[0] == '+' ? upper+1 : upper); /* take the destination without "+" prefix */ + if (!destination) + return -ENOMEM; + } else { + _cleanup_free_ char *p = NULL; + + /* If more than two parameters are specified, the last one is the destination, the second to last one + * the "upper", and all before that the "lower" directories. */ + + destination = lower[k - 1]; + upper = TAKE_PTR(lower[k - 2]); + + STRV_FOREACH(i, lower) { + r = source_path_parse(*i, &p); + if (r < 0) + return r; + + free_and_replace(*i, p); + } + + /* If the upper directory is unspecified, then let's create it automatically as a throw-away directory + * in /var/tmp */ + r = source_path_parse_nullable(upper, &p); + if (r < 0) + return r; + + free_and_replace(upper, p); + + if (!path_is_absolute(destination)) + return -EINVAL; + } + + m = custom_mount_add(l, n, CUSTOM_MOUNT_OVERLAY); + if (!m) + return -ENOMEM; + + m->destination = TAKE_PTR(destination); + m->source = TAKE_PTR(upper); + m->lower = TAKE_PTR(lower); + m->read_only = read_only; + + return 0; +} + +int inaccessible_mount_parse(CustomMount **l, size_t *n, const char *s) { + _cleanup_free_ char *path = NULL; + CustomMount *m; + + assert(l); + assert(n); + assert(s); + + if (!path_is_absolute(s)) + return -EINVAL; + + path = strdup(s); + if (!path) + return -ENOMEM; + + m = custom_mount_add(l, n, CUSTOM_MOUNT_INACCESSIBLE); + if (!m) + return -ENOMEM; + + m->destination = TAKE_PTR(path); + return 0; +} + +int tmpfs_patch_options( + const char *options, + uid_t uid_shift, + const char *selinux_apifs_context, + char **ret) { + + _cleanup_free_ char *buf = NULL; + + assert(ret); + + if (options) { + buf = strdup(options); + if (!buf) + return -ENOMEM; + } + + if (uid_shift != UID_INVALID) + if (strextendf_with_separator(&buf, ",", "uid=" UID_FMT ",gid=" UID_FMT, uid_shift, uid_shift) < 0) + return -ENOMEM; + +#if HAVE_SELINUX + if (selinux_apifs_context) + if (strextendf_with_separator(&buf, ",", "context=\"%s\"", selinux_apifs_context) < 0) + return -ENOMEM; +#endif + + *ret = TAKE_PTR(buf); + return !!*ret; +} + +int mount_sysfs(const char *dest, MountSettingsMask mount_settings) { + const char *full, *top; + int r; + unsigned long extra_flags = 0; + + top = prefix_roota(dest, "/sys"); + r = path_is_fs_type(top, SYSFS_MAGIC); + if (r < 0) + return log_error_errno(r, "Failed to determine filesystem type of %s: %m", top); + /* /sys might already be mounted as sysfs by the outer child in the + * !netns case. In this case, it's all good. Don't touch it because we + * don't have the right to do so, see https://github.com/systemd/systemd/issues/1555. + */ + if (r > 0) + return 0; + + full = prefix_roota(top, "/full"); + + (void) mkdir(full, 0755); + + if (FLAGS_SET(mount_settings, MOUNT_APPLY_APIVFS_RO)) + extra_flags |= MS_RDONLY; + + r = mount_nofollow_verbose(LOG_ERR, "sysfs", full, "sysfs", + MS_NOSUID|MS_NOEXEC|MS_NODEV|extra_flags, NULL); + if (r < 0) + return r; + + FOREACH_STRING(x, "block", "bus", "class", "dev", "devices", "kernel") { + _cleanup_free_ char *from = NULL, *to = NULL; + + from = path_join(full, x); + if (!from) + return log_oom(); + + to = path_join(top, x); + if (!to) + return log_oom(); + + (void) mkdir(to, 0755); + + r = mount_nofollow_verbose(LOG_ERR, from, to, NULL, MS_BIND, NULL); + if (r < 0) + return r; + + r = mount_nofollow_verbose(LOG_ERR, NULL, to, NULL, + MS_BIND|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_REMOUNT|extra_flags, NULL); + if (r < 0) + return r; + } + + r = umount_verbose(LOG_ERR, full, UMOUNT_NOFOLLOW); + if (r < 0) + return r; + + if (rmdir(full) < 0) + return log_error_errno(errno, "Failed to remove %s: %m", full); + + /* Create mountpoint for cgroups. Otherwise we are not allowed since we + * remount /sys read-only. + */ + const char *x = prefix_roota(top, "/fs/cgroup"); + (void) mkdir_p(x, 0755); + + return mount_nofollow_verbose(LOG_ERR, NULL, top, NULL, + MS_BIND|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_REMOUNT|extra_flags, NULL); +} + +int mount_all(const char *dest, + MountSettingsMask mount_settings, + uid_t uid_shift, + const char *selinux_apifs_context) { + +#define PROC_INACCESSIBLE_REG(path) \ + { "/run/systemd/inaccessible/reg", (path), NULL, NULL, MS_BIND, \ + MOUNT_IN_USERNS|MOUNT_APPLY_APIVFS_RO }, /* Bind mount first ... */ \ + { NULL, (path), NULL, NULL, MS_BIND|MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_REMOUNT, \ + MOUNT_IN_USERNS|MOUNT_APPLY_APIVFS_RO } /* Then, make it r/o */ + +#define PROC_READ_ONLY(path) \ + { (path), (path), NULL, NULL, MS_BIND, \ + MOUNT_IN_USERNS|MOUNT_APPLY_APIVFS_RO }, /* Bind mount first ... */ \ + { NULL, (path), NULL, NULL, MS_BIND|MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_REMOUNT, \ + MOUNT_IN_USERNS|MOUNT_APPLY_APIVFS_RO } /* Then, make it r/o */ + + typedef struct MountPoint { + const char *what; + const char *where; + const char *type; + const char *options; + unsigned long flags; + MountSettingsMask mount_settings; + } MountPoint; + + static const MountPoint mount_table[] = { + /* First we list inner child mounts (i.e. mounts applied *after* entering user namespacing) */ + { "proc", "/proc", "proc", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV, + MOUNT_FATAL|MOUNT_IN_USERNS|MOUNT_MKDIR|MOUNT_FOLLOW_SYMLINKS }, /* we follow symlinks here since not following them requires /proc/ already being mounted, which we don't have here. */ + + { "/proc/sys", "/proc/sys", NULL, NULL, MS_BIND, + MOUNT_FATAL|MOUNT_IN_USERNS|MOUNT_APPLY_APIVFS_RO }, /* Bind mount first ... */ + + { "/proc/sys/net", "/proc/sys/net", NULL, NULL, MS_BIND, + MOUNT_FATAL|MOUNT_IN_USERNS|MOUNT_APPLY_APIVFS_RO|MOUNT_APPLY_APIVFS_NETNS }, /* (except for this) */ + + { NULL, "/proc/sys", NULL, NULL, MS_BIND|MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_REMOUNT, + MOUNT_FATAL|MOUNT_IN_USERNS|MOUNT_APPLY_APIVFS_RO }, /* ... then, make it r/o */ + + /* Make these files inaccessible to container payloads: they potentially leak information about kernel + * internals or the host's execution environment to the container */ + PROC_INACCESSIBLE_REG("/proc/kallsyms"), + PROC_INACCESSIBLE_REG("/proc/kcore"), + PROC_INACCESSIBLE_REG("/proc/keys"), + PROC_INACCESSIBLE_REG("/proc/sysrq-trigger"), + PROC_INACCESSIBLE_REG("/proc/timer_list"), + + /* Make these directories read-only to container payloads: they show hardware information, and in some + * cases contain tunables the container really shouldn't have access to. */ + PROC_READ_ONLY("/proc/acpi"), + PROC_READ_ONLY("/proc/apm"), + PROC_READ_ONLY("/proc/asound"), + PROC_READ_ONLY("/proc/bus"), + PROC_READ_ONLY("/proc/fs"), + PROC_READ_ONLY("/proc/irq"), + PROC_READ_ONLY("/proc/scsi"), + + { "mqueue", "/dev/mqueue", "mqueue", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV, + MOUNT_IN_USERNS|MOUNT_MKDIR }, + + /* Then we list outer child mounts (i.e. mounts applied *before* entering user namespacing) */ + { "tmpfs", "/tmp", "tmpfs", "mode=1777" NESTED_TMPFS_LIMITS, MS_NOSUID|MS_NODEV|MS_STRICTATIME, + MOUNT_FATAL|MOUNT_APPLY_TMPFS_TMP|MOUNT_MKDIR }, + { "tmpfs", "/sys", "tmpfs", "mode=555" TMPFS_LIMITS_SYS, MS_NOSUID|MS_NOEXEC|MS_NODEV, + MOUNT_FATAL|MOUNT_APPLY_APIVFS_NETNS|MOUNT_MKDIR }, + { "sysfs", "/sys", "sysfs", NULL, MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV, + MOUNT_FATAL|MOUNT_APPLY_APIVFS_RO|MOUNT_MKDIR }, /* skipped if above was mounted */ + { "sysfs", "/sys", "sysfs", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV, + MOUNT_FATAL|MOUNT_MKDIR }, /* skipped if above was mounted */ + { "tmpfs", "/dev", "tmpfs", "mode=755" TMPFS_LIMITS_PRIVATE_DEV, MS_NOSUID|MS_STRICTATIME, + MOUNT_FATAL|MOUNT_MKDIR }, + { "tmpfs", "/dev/shm", "tmpfs", "mode=1777" NESTED_TMPFS_LIMITS, MS_NOSUID|MS_NODEV|MS_STRICTATIME, + MOUNT_FATAL|MOUNT_MKDIR }, + { "tmpfs", "/run", "tmpfs", "mode=755" TMPFS_LIMITS_RUN, MS_NOSUID|MS_NODEV|MS_STRICTATIME, + MOUNT_FATAL|MOUNT_MKDIR }, + { "/run/host", "/run/host", NULL, NULL, MS_BIND, + MOUNT_FATAL|MOUNT_MKDIR|MOUNT_PREFIX_ROOT }, /* Prepare this so that we can make it read-only when we are done */ + { "/etc/os-release", "/run/host/os-release", NULL, NULL, MS_BIND, + MOUNT_TOUCH }, /* As per kernel interface requirements, bind mount first (creating mount points) and make read-only later */ + { "/usr/lib/os-release", "/run/host/os-release", NULL, NULL, MS_BIND, + MOUNT_FATAL }, /* If /etc/os-release doesn't exist use the version in /usr/lib as fallback */ + { NULL, "/run/host/os-release", NULL, NULL, MS_BIND|MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_REMOUNT, + MOUNT_FATAL }, + { NULL, "/run/host", NULL, NULL, MS_BIND|MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_REMOUNT, + MOUNT_FATAL|MOUNT_IN_USERNS }, +#if HAVE_SELINUX + { "/sys/fs/selinux", "/sys/fs/selinux", NULL, NULL, MS_BIND, + MOUNT_MKDIR }, /* Bind mount first (mkdir/chown the mount point in case /sys/ is mounted as minimal skeleton tmpfs) */ + { NULL, "/sys/fs/selinux", NULL, NULL, MS_BIND|MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_REMOUNT, + 0 }, /* Then, make it r/o (don't mkdir/chown the mount point here, the previous entry already did that) */ +#endif + }; + + bool use_userns = FLAGS_SET(mount_settings, MOUNT_USE_USERNS); + bool netns = FLAGS_SET(mount_settings, MOUNT_APPLY_APIVFS_NETNS); + bool ro = FLAGS_SET(mount_settings, MOUNT_APPLY_APIVFS_RO); + bool in_userns = FLAGS_SET(mount_settings, MOUNT_IN_USERNS); + bool tmpfs_tmp = FLAGS_SET(mount_settings, MOUNT_APPLY_TMPFS_TMP); + int r; + + for (size_t k = 0; k < ELEMENTSOF(mount_table); k++) { + _cleanup_free_ char *where = NULL, *options = NULL, *prefixed = NULL; + bool fatal = FLAGS_SET(mount_table[k].mount_settings, MOUNT_FATAL); + const char *o; + + if (in_userns != FLAGS_SET(mount_table[k].mount_settings, MOUNT_IN_USERNS)) + continue; + + if (!netns && FLAGS_SET(mount_table[k].mount_settings, MOUNT_APPLY_APIVFS_NETNS)) + continue; + + if (!ro && FLAGS_SET(mount_table[k].mount_settings, MOUNT_APPLY_APIVFS_RO)) + continue; + + if (!tmpfs_tmp && FLAGS_SET(mount_table[k].mount_settings, MOUNT_APPLY_TMPFS_TMP)) + continue; + + r = chase_symlinks(mount_table[k].where, dest, CHASE_NONEXISTENT|CHASE_PREFIX_ROOT, &where, NULL); + if (r < 0) + return log_error_errno(r, "Failed to resolve %s%s: %m", strempty(dest), mount_table[k].where); + + /* Skip this entry if it is not a remount. */ + if (mount_table[k].what) { + r = path_is_mount_point(where, NULL, 0); + if (r < 0 && r != -ENOENT) + return log_error_errno(r, "Failed to detect whether %s is a mount point: %m", where); + if (r > 0) + continue; + } + + if ((mount_table[k].mount_settings & (MOUNT_MKDIR|MOUNT_TOUCH)) != 0) { + uid_t u = (use_userns && !in_userns) ? uid_shift : UID_INVALID; + + if (FLAGS_SET(mount_table[k].mount_settings, MOUNT_TOUCH)) + r = mkdir_parents_safe(dest, where, 0755, u, u, 0); + else + r = mkdir_p_safe(dest, where, 0755, u, u, 0); + if (r < 0 && r != -EEXIST) { + if (fatal && r != -EROFS) + return log_error_errno(r, "Failed to create directory %s: %m", where); + + log_debug_errno(r, "Failed to create directory %s: %m", where); + + /* If we failed mkdir() or chown() due to the root directory being read only, + * attempt to mount this fs anyway and let mount_verbose log any errors */ + if (r != -EROFS) + continue; + } + } + + if (FLAGS_SET(mount_table[k].mount_settings, MOUNT_TOUCH)) { + r = touch(where); + if (r < 0 && r != -EEXIST) { + if (fatal && r != -EROFS) + return log_error_errno(r, "Failed to create file %s: %m", where); + + log_debug_errno(r, "Failed to create file %s: %m", where); + if (r != -EROFS) + continue; + } + } + + o = mount_table[k].options; + if (streq_ptr(mount_table[k].type, "tmpfs")) { + r = tmpfs_patch_options(o, in_userns ? 0 : uid_shift, selinux_apifs_context, &options); + if (r < 0) + return log_oom(); + if (r > 0) + o = options; + } + + if (FLAGS_SET(mount_table[k].mount_settings, MOUNT_PREFIX_ROOT)) { + /* Optionally prefix the mount source with the root dir. This is useful in bind + * mounts to be created within the container image before we transition into it. Note + * that MOUNT_IN_USERNS is run after we transitioned hence prefixing is not ncessary + * for those. */ + r = chase_symlinks(mount_table[k].what, dest, CHASE_PREFIX_ROOT, &prefixed, NULL); + if (r < 0) + return log_error_errno(r, "Failed to resolve %s%s: %m", strempty(dest), mount_table[k].what); + } + + r = mount_verbose_full( + fatal ? LOG_ERR : LOG_DEBUG, + prefixed ?: mount_table[k].what, + where, + mount_table[k].type, + mount_table[k].flags, + o, + FLAGS_SET(mount_table[k].mount_settings, MOUNT_FOLLOW_SYMLINKS)); + if (r < 0 && fatal) + return r; + } + + return 0; +} + +static int parse_mount_bind_options(const char *options, unsigned long *mount_flags, char **mount_opts, RemountIdmapping *idmapping) { + unsigned long flags = *mount_flags; + char *opts = NULL; + RemountIdmapping new_idmapping = *idmapping; + int r; + + assert(options); + + for (;;) { + _cleanup_free_ char *word = NULL; + + r = extract_first_word(&options, &word, ",", 0); + if (r < 0) + return log_error_errno(r, "Failed to extract mount option: %m"); + if (r == 0) + break; + + if (streq(word, "rbind")) + flags |= MS_REC; + else if (streq(word, "norbind")) + flags &= ~MS_REC; + else if (streq(word, "idmap")) + new_idmapping = REMOUNT_IDMAPPING_HOST_ROOT; + else if (streq(word, "noidmap")) + new_idmapping = REMOUNT_IDMAPPING_NONE; + else if (streq(word, "rootidmap")) + new_idmapping = REMOUNT_IDMAPPING_HOST_OWNER; + else + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), + "Invalid bind mount option: %s", word); + } + + *mount_flags = flags; + *idmapping = new_idmapping; + /* in the future mount_opts will hold string options for mount(2) */ + *mount_opts = opts; + + return 0; +} + +static int mount_bind(const char *dest, CustomMount *m, uid_t uid_shift, uid_t uid_range) { + _cleanup_free_ char *mount_opts = NULL, *where = NULL; + unsigned long mount_flags = MS_BIND | MS_REC; + struct stat source_st, dest_st; + int r; + RemountIdmapping idmapping = REMOUNT_IDMAPPING_NONE; + + assert(dest); + assert(m); + + if (m->options) { + r = parse_mount_bind_options(m->options, &mount_flags, &mount_opts, &idmapping); + if (r < 0) + return r; + } + + /* If this is a bind mount from a temporary sources change ownership of the source to the container's + * root UID. Otherwise it would always show up as "nobody" if user namespacing is used. */ + if (m->rm_rf_tmpdir && chown(m->source, uid_shift, uid_shift) < 0) + return log_error_errno(errno, "Failed to chown %s: %m", m->source); + + if (stat(m->source, &source_st) < 0) + return log_error_errno(errno, "Failed to stat %s: %m", m->source); + + r = chase_symlinks(m->destination, dest, CHASE_PREFIX_ROOT|CHASE_NONEXISTENT, &where, NULL); + if (r < 0) + return log_error_errno(r, "Failed to resolve %s/%s: %m", dest, m->destination); + if (r > 0) { /* Path exists already? */ + + if (stat(where, &dest_st) < 0) + return log_error_errno(errno, "Failed to stat %s: %m", where); + + if (S_ISDIR(source_st.st_mode) && !S_ISDIR(dest_st.st_mode)) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), + "Cannot bind mount directory %s on file %s.", + m->source, where); + + if (!S_ISDIR(source_st.st_mode) && S_ISDIR(dest_st.st_mode)) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), + "Cannot bind mount file %s on directory %s.", + m->source, where); + + } else { /* Path doesn't exist yet? */ + r = mkdir_parents_label(where, 0755); + if (r < 0) + return log_error_errno(r, "Failed to make parents of %s: %m", where); + + /* Create the mount point. Any non-directory file can be + * mounted on any non-directory file (regular, fifo, socket, + * char, block). + */ + if (S_ISDIR(source_st.st_mode)) + r = mkdir_label(where, 0755); + else + r = touch(where); + if (r < 0) + return log_error_errno(r, "Failed to create mount point %s: %m", where); + } + + r = mount_nofollow_verbose(LOG_ERR, m->source, where, NULL, mount_flags, mount_opts); + if (r < 0) + return r; + + if (m->read_only) { + r = bind_remount_recursive(where, MS_RDONLY, MS_RDONLY, NULL); + if (r < 0) + return log_error_errno(r, "Read-only bind mount failed: %m"); + } + + if (idmapping != REMOUNT_IDMAPPING_NONE) { + r = remount_idmap(where, uid_shift, uid_range, source_st.st_uid, idmapping); + if (r < 0) + return log_error_errno(r, "Failed to map ids for bind mount %s: %m", where); + } + + return 0; +} + +static int mount_tmpfs(const char *dest, CustomMount *m, uid_t uid_shift, const char *selinux_apifs_context) { + const char *options; + _cleanup_free_ char *buf = NULL, *where = NULL; + int r; + + assert(dest); + assert(m); + + r = chase_symlinks(m->destination, dest, CHASE_PREFIX_ROOT|CHASE_NONEXISTENT, &where, NULL); + if (r < 0) + return log_error_errno(r, "Failed to resolve %s/%s: %m", dest, m->destination); + if (r == 0) { /* Doesn't exist yet? */ + r = mkdir_p_label(where, 0755); + if (r < 0) + return log_error_errno(r, "Creating mount point for tmpfs %s failed: %m", where); + } + + r = tmpfs_patch_options(m->options, uid_shift == 0 ? UID_INVALID : uid_shift, selinux_apifs_context, &buf); + if (r < 0) + return log_oom(); + options = r > 0 ? buf : m->options; + + return mount_nofollow_verbose(LOG_ERR, "tmpfs", where, "tmpfs", MS_NODEV|MS_STRICTATIME, options); +} + +static char *joined_and_escaped_lower_dirs(char **lower) { + _cleanup_strv_free_ char **sv = NULL; + + sv = strv_copy(lower); + if (!sv) + return NULL; + + strv_reverse(sv); + + if (!strv_shell_escape(sv, ",:")) + return NULL; + + return strv_join(sv, ":"); +} + +static int mount_overlay(const char *dest, CustomMount *m) { + _cleanup_free_ char *lower = NULL, *where = NULL, *escaped_source = NULL; + const char *options; + int r; + + assert(dest); + assert(m); + + r = chase_symlinks(m->destination, dest, CHASE_PREFIX_ROOT|CHASE_NONEXISTENT, &where, NULL); + if (r < 0) + return log_error_errno(r, "Failed to resolve %s/%s: %m", dest, m->destination); + if (r == 0) { /* Doesn't exist yet? */ + r = mkdir_label(where, 0755); + if (r < 0) + return log_error_errno(r, "Creating mount point for overlay %s failed: %m", where); + } + + (void) mkdir_p_label(m->source, 0755); + + lower = joined_and_escaped_lower_dirs(m->lower); + if (!lower) + return log_oom(); + + escaped_source = shell_escape(m->source, ",:"); + if (!escaped_source) + return log_oom(); + + if (m->read_only) + options = strjoina("lowerdir=", escaped_source, ":", lower); + else { + _cleanup_free_ char *escaped_work_dir = NULL; + + escaped_work_dir = shell_escape(m->work_dir, ",:"); + if (!escaped_work_dir) + return log_oom(); + + options = strjoina("lowerdir=", lower, ",upperdir=", escaped_source, ",workdir=", escaped_work_dir); + } + + return mount_nofollow_verbose(LOG_ERR, "overlay", where, "overlay", m->read_only ? MS_RDONLY : 0, options); +} + +static int mount_inaccessible(const char *dest, CustomMount *m) { + _cleanup_free_ char *where = NULL, *source = NULL; + struct stat st; + int r; + + assert(dest); + assert(m); + + r = chase_symlinks_and_stat(m->destination, dest, CHASE_PREFIX_ROOT, &where, &st, NULL); + if (r < 0) { + log_full_errno(m->graceful ? LOG_DEBUG : LOG_ERR, r, "Failed to resolve %s/%s: %m", dest, m->destination); + return m->graceful ? 0 : r; + } + + r = mode_to_inaccessible_node(NULL, st.st_mode, &source); + if (r < 0) + return m->graceful ? 0 : r; + + r = mount_nofollow_verbose(m->graceful ? LOG_DEBUG : LOG_ERR, source, where, NULL, MS_BIND, NULL); + if (r < 0) + return m->graceful ? 0 : r; + + r = mount_nofollow_verbose(m->graceful ? LOG_DEBUG : LOG_ERR, NULL, where, NULL, MS_BIND|MS_RDONLY|MS_REMOUNT, NULL); + if (r < 0) { + (void) umount_verbose(m->graceful ? LOG_DEBUG : LOG_ERR, where, UMOUNT_NOFOLLOW); + return m->graceful ? 0 : r; + } + + return 0; +} + +static int mount_arbitrary(const char *dest, CustomMount *m) { + _cleanup_free_ char *where = NULL; + int r; + + assert(dest); + assert(m); + + r = chase_symlinks(m->destination, dest, CHASE_PREFIX_ROOT|CHASE_NONEXISTENT, &where, NULL); + if (r < 0) + return log_error_errno(r, "Failed to resolve %s/%s: %m", dest, m->destination); + if (r == 0) { /* Doesn't exist yet? */ + r = mkdir_p_label(where, 0755); + if (r < 0) + return log_error_errno(r, "Creating mount point for mount %s failed: %m", where); + } + + return mount_nofollow_verbose(LOG_ERR, m->source, where, m->type_argument, 0, m->options); +} + +int mount_custom( + const char *dest, + CustomMount *mounts, size_t n, + uid_t uid_shift, + uid_t uid_range, + const char *selinux_apifs_context, + MountSettingsMask mount_settings) { + int r; + + assert(dest); + + for (size_t i = 0; i < n; i++) { + CustomMount *m = mounts + i; + + if (FLAGS_SET(mount_settings, MOUNT_IN_USERNS) != m->in_userns) + continue; + + if (FLAGS_SET(mount_settings, MOUNT_ROOT_ONLY) && !path_equal(m->destination, "/")) + continue; + + if (FLAGS_SET(mount_settings, MOUNT_NON_ROOT_ONLY) && path_equal(m->destination, "/")) + continue; + + switch (m->type) { + + case CUSTOM_MOUNT_BIND: + r = mount_bind(dest, m, uid_shift, uid_range); + break; + + case CUSTOM_MOUNT_TMPFS: + r = mount_tmpfs(dest, m, uid_shift, selinux_apifs_context); + break; + + case CUSTOM_MOUNT_OVERLAY: + r = mount_overlay(dest, m); + break; + + case CUSTOM_MOUNT_INACCESSIBLE: + r = mount_inaccessible(dest, m); + break; + + case CUSTOM_MOUNT_ARBITRARY: + r = mount_arbitrary(dest, m); + break; + + default: + assert_not_reached(); + } + + if (r < 0) + return r; + } + + return 0; +} + +bool has_custom_root_mount(const CustomMount *mounts, size_t n) { + for (size_t i = 0; i < n; i++) + if (path_equal(mounts[i].destination, "/")) + return true; + + return false; +} + +static int setup_volatile_state(const char *directory, uid_t uid_shift, const char *selinux_apifs_context) { + _cleanup_free_ char *buf = NULL; + const char *p, *options; + int r; + + assert(directory); + + /* --volatile=state means we simply overmount /var with a tmpfs, and the rest read-only. */ + + r = bind_remount_recursive(directory, MS_RDONLY, MS_RDONLY, NULL); + if (r < 0) + return log_error_errno(r, "Failed to remount %s read-only: %m", directory); + + p = prefix_roota(directory, "/var"); + r = mkdir(p, 0755); + if (r < 0 && errno != EEXIST) + return log_error_errno(errno, "Failed to create %s: %m", directory); + + options = "mode=755" TMPFS_LIMITS_VOLATILE_STATE; + r = tmpfs_patch_options(options, uid_shift == 0 ? UID_INVALID : uid_shift, selinux_apifs_context, &buf); + if (r < 0) + return log_oom(); + if (r > 0) + options = buf; + + return mount_nofollow_verbose(LOG_ERR, "tmpfs", p, "tmpfs", MS_STRICTATIME, options); +} + +static int setup_volatile_yes(const char *directory, uid_t uid_shift, const char *selinux_apifs_context) { + bool tmpfs_mounted = false, bind_mounted = false; + char template[] = "/tmp/nspawn-volatile-XXXXXX"; + _cleanup_free_ char *buf = NULL, *bindir = NULL; + const char *f, *t, *options; + struct stat st; + int r; + + assert(directory); + + /* --volatile=yes means we mount a tmpfs to the root dir, and the original /usr to use inside it, and + * that read-only. Before we start setting this up let's validate if the image has the /usr merge + * implemented, and let's output a friendly log message if it hasn't. */ + + bindir = path_join(directory, "/bin"); + if (!bindir) + return log_oom(); + if (lstat(bindir, &st) < 0) { + if (errno != ENOENT) + return log_error_errno(errno, "Failed to stat /bin directory below image: %m"); + + /* ENOENT is fine, just means the image is probably just a naked /usr and we can create the + * rest. */ + } else if (S_ISDIR(st.st_mode)) + return log_error_errno(SYNTHETIC_ERRNO(EISDIR), + "Sorry, --volatile=yes mode is not supported with OS images that have not merged /bin/, /sbin/, /lib/, /lib64/ into /usr/. " + "Please work with your distribution and help them adopt the merged /usr scheme."); + else if (!S_ISLNK(st.st_mode)) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), + "Error starting image: if --volatile=yes is used /bin must be a symlink (for merged /usr support) or non-existent (in which case a symlink is created automatically)."); + + if (!mkdtemp(template)) + return log_error_errno(errno, "Failed to create temporary directory: %m"); + + options = "mode=755" TMPFS_LIMITS_ROOTFS; + r = tmpfs_patch_options(options, uid_shift == 0 ? UID_INVALID : uid_shift, selinux_apifs_context, &buf); + if (r < 0) + goto fail; + if (r > 0) + options = buf; + + r = mount_nofollow_verbose(LOG_ERR, "tmpfs", template, "tmpfs", MS_STRICTATIME, options); + if (r < 0) + goto fail; + + tmpfs_mounted = true; + + f = prefix_roota(directory, "/usr"); + t = prefix_roota(template, "/usr"); + + r = mkdir(t, 0755); + if (r < 0 && errno != EEXIST) { + r = log_error_errno(errno, "Failed to create %s: %m", t); + goto fail; + } + + r = mount_nofollow_verbose(LOG_ERR, f, t, NULL, MS_BIND|MS_REC, NULL); + if (r < 0) + goto fail; + + bind_mounted = true; + + r = bind_remount_recursive(t, MS_RDONLY, MS_RDONLY, NULL); + if (r < 0) { + log_error_errno(r, "Failed to remount %s read-only: %m", t); + goto fail; + } + + r = mount_nofollow_verbose(LOG_ERR, template, directory, NULL, MS_MOVE, NULL); + if (r < 0) + goto fail; + + (void) rmdir(template); + + return 0; + +fail: + if (bind_mounted) + (void) umount_verbose(LOG_ERR, t, UMOUNT_NOFOLLOW); + + if (tmpfs_mounted) + (void) umount_verbose(LOG_ERR, template, UMOUNT_NOFOLLOW); + + (void) rmdir(template); + return r; +} + +static int setup_volatile_overlay(const char *directory, uid_t uid_shift, const char *selinux_apifs_context) { + _cleanup_free_ char *buf = NULL, *escaped_directory = NULL, *escaped_upper = NULL, *escaped_work = NULL; + char template[] = "/tmp/nspawn-volatile-XXXXXX"; + const char *upper, *work, *options; + bool tmpfs_mounted = false; + int r; + + assert(directory); + + /* --volatile=overlay means we mount an overlayfs to the root dir. */ + + if (!mkdtemp(template)) + return log_error_errno(errno, "Failed to create temporary directory: %m"); + + options = "mode=755" TMPFS_LIMITS_ROOTFS; + r = tmpfs_patch_options(options, uid_shift == 0 ? UID_INVALID : uid_shift, selinux_apifs_context, &buf); + if (r < 0) + goto finish; + if (r > 0) + options = buf; + + r = mount_nofollow_verbose(LOG_ERR, "tmpfs", template, "tmpfs", MS_STRICTATIME, options); + if (r < 0) + goto finish; + + tmpfs_mounted = true; + + upper = strjoina(template, "/upper"); + work = strjoina(template, "/work"); + + if (mkdir(upper, 0755) < 0) { + r = log_error_errno(errno, "Failed to create %s: %m", upper); + goto finish; + } + if (mkdir(work, 0755) < 0) { + r = log_error_errno(errno, "Failed to create %s: %m", work); + goto finish; + } + + /* And now, let's overmount the root dir with an overlayfs that uses the root dir as lower dir. It's kinda nice + * that the kernel allows us to do that without going through some mount point rearrangements. */ + + escaped_directory = shell_escape(directory, ",:"); + escaped_upper = shell_escape(upper, ",:"); + escaped_work = shell_escape(work, ",:"); + if (!escaped_directory || !escaped_upper || !escaped_work) { + r = -ENOMEM; + goto finish; + } + + options = strjoina("lowerdir=", escaped_directory, ",upperdir=", escaped_upper, ",workdir=", escaped_work); + r = mount_nofollow_verbose(LOG_ERR, "overlay", directory, "overlay", 0, options); + +finish: + if (tmpfs_mounted) + (void) umount_verbose(LOG_ERR, template, UMOUNT_NOFOLLOW); + + (void) rmdir(template); + return r; +} + +int setup_volatile_mode( + const char *directory, + VolatileMode mode, + uid_t uid_shift, + const char *selinux_apifs_context) { + + switch (mode) { + + case VOLATILE_YES: + return setup_volatile_yes(directory, uid_shift, selinux_apifs_context); + + case VOLATILE_STATE: + return setup_volatile_state(directory, uid_shift, selinux_apifs_context); + + case VOLATILE_OVERLAY: + return setup_volatile_overlay(directory, uid_shift, selinux_apifs_context); + + default: + return 0; + } +} + +/* Expects *pivot_root_new and *pivot_root_old to be initialised to allocated memory or NULL. */ +int pivot_root_parse(char **pivot_root_new, char **pivot_root_old, const char *s) { + _cleanup_free_ char *root_new = NULL, *root_old = NULL; + const char *p = s; + int r; + + assert(pivot_root_new); + assert(pivot_root_old); + + r = extract_first_word(&p, &root_new, ":", EXTRACT_DONT_COALESCE_SEPARATORS); + if (r < 0) + return r; + if (r == 0) + return -EINVAL; + + if (isempty(p)) + root_old = NULL; + else { + root_old = strdup(p); + if (!root_old) + return -ENOMEM; + } + + if (!path_is_absolute(root_new)) + return -EINVAL; + if (root_old && !path_is_absolute(root_old)) + return -EINVAL; + + free_and_replace(*pivot_root_new, root_new); + free_and_replace(*pivot_root_old, root_old); + + return 0; +} + +int setup_pivot_root(const char *directory, const char *pivot_root_new, const char *pivot_root_old) { + _cleanup_free_ char *directory_pivot_root_new = NULL; + _cleanup_free_ char *pivot_tmp_pivot_root_old = NULL; + char pivot_tmp[] = "/tmp/nspawn-pivot-XXXXXX"; + bool remove_pivot_tmp = false; + int r; + + assert(directory); + + if (!pivot_root_new) + return 0; + + /* Pivot pivot_root_new to / and the existing / to pivot_root_old. + * If pivot_root_old is NULL, the existing / disappears. + * This requires a temporary directory, pivot_tmp, which is + * not a child of either. + * + * This is typically used for OSTree-style containers, where the root partition contains several + * sysroots which could be run. Normally, one would be chosen by the bootloader and pivoted to / by + * initrd. + * + * For example, for an OSTree deployment, pivot_root_new + * would be: /ostree/deploy/$os/deploy/$checksum. Note that this + * code doesn’t do the /var mount which OSTree expects: use + * --bind +/sysroot/ostree/deploy/$os/var:/var for that. + * + * So in the OSTree case, we’ll end up with something like: + * - directory = /tmp/nspawn-root-123456 + * - pivot_root_new = /ostree/deploy/os/deploy/123abc + * - pivot_root_old = /sysroot + * - directory_pivot_root_new = + * /tmp/nspawn-root-123456/ostree/deploy/os/deploy/123abc + * - pivot_tmp = /tmp/nspawn-pivot-123456 + * - pivot_tmp_pivot_root_old = /tmp/nspawn-pivot-123456/sysroot + * + * Requires all file systems at directory and below to be mounted + * MS_PRIVATE or MS_SLAVE so they can be moved. + */ + directory_pivot_root_new = path_join(directory, pivot_root_new); + if (!directory_pivot_root_new) + return log_oom(); + + /* Remount directory_pivot_root_new to make it movable. */ + r = mount_nofollow_verbose(LOG_ERR, directory_pivot_root_new, directory_pivot_root_new, NULL, MS_BIND, NULL); + if (r < 0) + goto done; + + if (pivot_root_old) { + if (!mkdtemp(pivot_tmp)) { + r = log_error_errno(errno, "Failed to create temporary directory: %m"); + goto done; + } + + remove_pivot_tmp = true; + pivot_tmp_pivot_root_old = path_join(pivot_tmp, pivot_root_old); + if (!pivot_tmp_pivot_root_old) { + r = log_oom(); + goto done; + } + + r = mount_nofollow_verbose(LOG_ERR, directory_pivot_root_new, pivot_tmp, NULL, MS_MOVE, NULL); + if (r < 0) + goto done; + + r = mount_nofollow_verbose(LOG_ERR, directory, pivot_tmp_pivot_root_old, NULL, MS_MOVE, NULL); + if (r < 0) + goto done; + + r = mount_nofollow_verbose(LOG_ERR, pivot_tmp, directory, NULL, MS_MOVE, NULL); + if (r < 0) + goto done; + } else { + r = mount_nofollow_verbose(LOG_ERR, directory_pivot_root_new, directory, NULL, MS_MOVE, NULL); + if (r < 0) + goto done; + } + +done: + if (remove_pivot_tmp) + (void) rmdir(pivot_tmp); + + return r; +} diff --git a/src/nspawn/nspawn-mount.h b/src/nspawn/nspawn-mount.h new file mode 100644 index 0000000..6bedbf9 --- /dev/null +++ b/src/nspawn/nspawn-mount.h @@ -0,0 +1,69 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ +#pragma once + +#include <stdbool.h> + +#include "cgroup-util.h" +#include "volatile-util.h" + +typedef enum MountSettingsMask { + MOUNT_FATAL = 1 << 0, /* if set, a mount error is considered fatal */ + MOUNT_USE_USERNS = 1 << 1, /* if set, mounts are patched considering uid/gid shifts in a user namespace */ + MOUNT_IN_USERNS = 1 << 2, /* if set, the mount is executed in the inner child, otherwise in the outer child */ + MOUNT_APPLY_APIVFS_RO = 1 << 3, /* if set, /proc/sys, and /sys will be mounted read-only, otherwise read-write. */ + MOUNT_APPLY_APIVFS_NETNS = 1 << 4, /* if set, /proc/sys/net will be mounted read-write. + Works only if MOUNT_APPLY_APIVFS_RO is also set. */ + MOUNT_APPLY_TMPFS_TMP = 1 << 5, /* if set, /tmp will be mounted as tmpfs */ + MOUNT_ROOT_ONLY = 1 << 6, /* if set, only root mounts are mounted */ + MOUNT_NON_ROOT_ONLY = 1 << 7, /* if set, only non-root mounts are mounted */ + MOUNT_MKDIR = 1 << 8, /* if set, make directory to mount over first */ + MOUNT_TOUCH = 1 << 9, /* if set, touch file to mount over first */ + MOUNT_PREFIX_ROOT = 1 << 10,/* if set, prefix the source path with the container's root directory */ + MOUNT_FOLLOW_SYMLINKS = 1 << 11,/* if set, we'll follow symlinks for the mount target */ +} MountSettingsMask; + +typedef enum CustomMountType { + CUSTOM_MOUNT_BIND, + CUSTOM_MOUNT_TMPFS, + CUSTOM_MOUNT_OVERLAY, + CUSTOM_MOUNT_INACCESSIBLE, + CUSTOM_MOUNT_ARBITRARY, + _CUSTOM_MOUNT_TYPE_MAX, + _CUSTOM_MOUNT_TYPE_INVALID = -EINVAL, +} CustomMountType; + +typedef struct CustomMount { + CustomMountType type; + bool read_only; + char *source; /* for overlayfs this is the upper directory */ + char *destination; + char *options; + char *work_dir; + char **lower; + char *rm_rf_tmpdir; + char *type_argument; /* only for CUSTOM_MOUNT_ARBITRARY */ + bool graceful; + bool in_userns; +} CustomMount; + +CustomMount* custom_mount_add(CustomMount **l, size_t *n, CustomMountType t); +void custom_mount_free_all(CustomMount *l, size_t n); +int custom_mount_prepare_all(const char *dest, CustomMount *l, size_t n); + +int bind_mount_parse(CustomMount **l, size_t *n, const char *s, bool read_only); +int tmpfs_mount_parse(CustomMount **l, size_t *n, const char *s); +int overlay_mount_parse(CustomMount **l, size_t *n, const char *s, bool read_only); +int inaccessible_mount_parse(CustomMount **l, size_t *n, const char *s); + +int mount_all(const char *dest, MountSettingsMask mount_settings, uid_t uid_shift, const char *selinux_apifs_context); +int mount_sysfs(const char *dest, MountSettingsMask mount_settings); + +int mount_custom(const char *dest, CustomMount *mounts, size_t n, uid_t uid_shift, uid_t uid_range, const char *selinux_apifs_context, MountSettingsMask mount_settings); +bool has_custom_root_mount(const CustomMount *mounts, size_t n); + +int setup_volatile_mode(const char *directory, VolatileMode mode, uid_t uid_shift, const char *selinux_apifs_context); + +int pivot_root_parse(char **pivot_root_new, char **pivot_root_old, const char *s); +int setup_pivot_root(const char *directory, const char *pivot_root_new, const char *pivot_root_old); + +int tmpfs_patch_options(const char *options,uid_t uid_shift, const char *selinux_apifs_context, char **ret); diff --git a/src/nspawn/nspawn-network.c b/src/nspawn/nspawn-network.c new file mode 100644 index 0000000..536e369 --- /dev/null +++ b/src/nspawn/nspawn-network.c @@ -0,0 +1,745 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include <net/if.h> +#include <linux/if.h> +#include <linux/veth.h> +#include <sys/file.h> + +#include "sd-device.h" +#include "sd-id128.h" +#include "sd-netlink.h" + +#include "alloc-util.h" +#include "ether-addr-util.h" +#include "hexdecoct.h" +#include "lockfile-util.h" +#include "missing_network.h" +#include "netif-naming-scheme.h" +#include "netlink-util.h" +#include "nspawn-network.h" +#include "parse-util.h" +#include "siphash24.h" +#include "socket-netlink.h" +#include "socket-util.h" +#include "stat-util.h" +#include "string-util.h" +#include "strv.h" +#include "udev-util.h" +#include "util.h" + +#define HOST_HASH_KEY SD_ID128_MAKE(1a,37,6f,c7,46,ec,45,0b,ad,a3,d5,31,06,60,5d,b1) +#define CONTAINER_HASH_KEY SD_ID128_MAKE(c3,c4,f9,19,b5,57,b2,1c,e6,cf,14,27,03,9c,ee,a2) +#define VETH_EXTRA_HOST_HASH_KEY SD_ID128_MAKE(48,c7,f6,b7,ea,9d,4c,9e,b7,28,d4,de,91,d5,bf,66) +#define VETH_EXTRA_CONTAINER_HASH_KEY SD_ID128_MAKE(af,50,17,61,ce,f9,4d,35,84,0d,2b,20,54,be,ce,59) +#define MACVLAN_HASH_KEY SD_ID128_MAKE(00,13,6d,bc,66,83,44,81,bb,0c,f9,51,1f,24,a6,6f) +#define SHORTEN_IFNAME_HASH_KEY SD_ID128_MAKE(e1,90,a4,04,a8,ef,4b,51,8c,cc,c3,3a,9f,11,fc,a2) + +static int remove_one_link(sd_netlink *rtnl, const char *name) { + _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL; + int r; + + if (isempty(name)) + return 0; + + r = sd_rtnl_message_new_link(rtnl, &m, RTM_DELLINK, 0); + if (r < 0) + return log_error_errno(r, "Failed to allocate netlink message: %m"); + + r = sd_netlink_message_append_string(m, IFLA_IFNAME, name); + if (r < 0) + return log_error_errno(r, "Failed to add netlink interface name: %m"); + + r = sd_netlink_call(rtnl, m, 0, NULL); + if (r == -ENODEV) /* Already gone */ + return 0; + if (r < 0) + return log_error_errno(r, "Failed to remove interface %s: %m", name); + + return 1; +} + +static int generate_mac( + const char *machine_name, + struct ether_addr *mac, + sd_id128_t hash_key, + uint64_t idx) { + + uint64_t result; + size_t l, sz; + uint8_t *v, *i; + int r; + + l = strlen(machine_name); + sz = sizeof(sd_id128_t) + l; + if (idx > 0) + sz += sizeof(idx); + + v = newa(uint8_t, sz); + + /* fetch some persistent data unique to the host */ + r = sd_id128_get_machine((sd_id128_t*) v); + if (r < 0) + return r; + + /* combine with some data unique (on this host) to this + * container instance */ + i = mempcpy(v + sizeof(sd_id128_t), machine_name, l); + if (idx > 0) { + idx = htole64(idx); + memcpy(i, &idx, sizeof(idx)); + } + + /* Let's hash the host machine ID plus the container name. We + * use a fixed, but originally randomly created hash key here. */ + result = htole64(siphash24(v, sz, hash_key.bytes)); + + assert_cc(ETH_ALEN <= sizeof(result)); + memcpy(mac->ether_addr_octet, &result, ETH_ALEN); + + /* see eth_random_addr in the kernel */ + mac->ether_addr_octet[0] &= 0xfe; /* clear multicast bit */ + mac->ether_addr_octet[0] |= 0x02; /* set local assignment bit (IEEE802) */ + + return 0; +} + +static int set_alternative_ifname(sd_netlink *rtnl, const char *ifname, const char *altifname) { + int r; + + assert(rtnl); + assert(ifname); + + if (!altifname) + return 0; + + if (strlen(altifname) >= ALTIFNAMSIZ) + return log_warning_errno(SYNTHETIC_ERRNO(ERANGE), + "Alternative interface name '%s' for '%s' is too long, ignoring", + altifname, ifname); + + r = rtnl_set_link_alternative_names_by_ifname(&rtnl, ifname, STRV_MAKE(altifname)); + if (r < 0) + return log_warning_errno(r, + "Failed to set alternative interface name '%s' to '%s', ignoring: %m", + altifname, ifname); + + return 0; +} + +static int add_veth( + sd_netlink *rtnl, + pid_t pid, + const char *ifname_host, + const char *altifname_host, + const struct ether_addr *mac_host, + const char *ifname_container, + const struct ether_addr *mac_container) { + + _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL; + int r; + + assert(rtnl); + assert(ifname_host); + assert(mac_host); + assert(ifname_container); + assert(mac_container); + + r = sd_rtnl_message_new_link(rtnl, &m, RTM_NEWLINK, 0); + if (r < 0) + return log_error_errno(r, "Failed to allocate netlink message: %m"); + + r = sd_netlink_message_append_string(m, IFLA_IFNAME, ifname_host); + if (r < 0) + return log_error_errno(r, "Failed to add netlink interface name: %m"); + + r = sd_netlink_message_append_ether_addr(m, IFLA_ADDRESS, mac_host); + if (r < 0) + return log_error_errno(r, "Failed to add netlink MAC address: %m"); + + r = sd_netlink_message_open_container(m, IFLA_LINKINFO); + if (r < 0) + return log_error_errno(r, "Failed to open netlink container: %m"); + + r = sd_netlink_message_open_container_union(m, IFLA_INFO_DATA, "veth"); + if (r < 0) + return log_error_errno(r, "Failed to open netlink container: %m"); + + r = sd_netlink_message_open_container(m, VETH_INFO_PEER); + if (r < 0) + return log_error_errno(r, "Failed to open netlink container: %m"); + + r = sd_netlink_message_append_string(m, IFLA_IFNAME, ifname_container); + if (r < 0) + return log_error_errno(r, "Failed to add netlink interface name: %m"); + + r = sd_netlink_message_append_ether_addr(m, IFLA_ADDRESS, mac_container); + if (r < 0) + return log_error_errno(r, "Failed to add netlink MAC address: %m"); + + r = sd_netlink_message_append_u32(m, IFLA_NET_NS_PID, pid); + if (r < 0) + return log_error_errno(r, "Failed to add netlink namespace field: %m"); + + r = sd_netlink_message_close_container(m); + if (r < 0) + return log_error_errno(r, "Failed to close netlink container: %m"); + + r = sd_netlink_message_close_container(m); + if (r < 0) + return log_error_errno(r, "Failed to close netlink container: %m"); + + r = sd_netlink_message_close_container(m); + if (r < 0) + return log_error_errno(r, "Failed to close netlink container: %m"); + + r = sd_netlink_call(rtnl, m, 0, NULL); + if (r < 0) + return log_error_errno(r, "Failed to add new veth interfaces (%s:%s): %m", ifname_host, ifname_container); + + (void) set_alternative_ifname(rtnl, ifname_host, altifname_host); + + return 0; +} + +static int shorten_ifname(char *ifname) { + char new_ifname[IFNAMSIZ]; + + assert(ifname); + + if (strlen(ifname) < IFNAMSIZ) /* Name is short enough */ + return 0; + + if (naming_scheme_has(NAMING_NSPAWN_LONG_HASH)) { + uint64_t h; + + /* Calculate 64bit hash value */ + h = siphash24(ifname, strlen(ifname), SHORTEN_IFNAME_HASH_KEY.bytes); + + /* Set the final four bytes (i.e. 32bit) to the lower 24bit of the hash, encoded in url-safe base64 */ + memcpy(new_ifname, ifname, IFNAMSIZ - 5); + new_ifname[IFNAMSIZ - 5] = urlsafe_base64char(h >> 18); + new_ifname[IFNAMSIZ - 4] = urlsafe_base64char(h >> 12); + new_ifname[IFNAMSIZ - 3] = urlsafe_base64char(h >> 6); + new_ifname[IFNAMSIZ - 2] = urlsafe_base64char(h); + } else + /* On old nspawn versions we just truncated the name, provide compatibility */ + memcpy(new_ifname, ifname, IFNAMSIZ-1); + + new_ifname[IFNAMSIZ - 1] = 0; + + /* Log the incident to make it more discoverable */ + log_warning("Network interface name '%s' has been changed to '%s' to fit length constraints.", ifname, new_ifname); + + strcpy(ifname, new_ifname); + return 1; +} + +int setup_veth(const char *machine_name, + pid_t pid, + char iface_name[IFNAMSIZ], + bool bridge) { + + _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL; + struct ether_addr mac_host, mac_container; + unsigned u; + char *n, *a = NULL; + int r; + + assert(machine_name); + assert(pid > 0); + assert(iface_name); + + /* Use two different interface name prefixes depending whether + * we are in bridge mode or not. */ + n = strjoina(bridge ? "vb-" : "ve-", machine_name); + r = shorten_ifname(n); + if (r > 0) + a = strjoina(bridge ? "vb-" : "ve-", machine_name); + + r = generate_mac(machine_name, &mac_container, CONTAINER_HASH_KEY, 0); + if (r < 0) + return log_error_errno(r, "Failed to generate predictable MAC address for container side: %m"); + + r = generate_mac(machine_name, &mac_host, HOST_HASH_KEY, 0); + if (r < 0) + return log_error_errno(r, "Failed to generate predictable MAC address for host side: %m"); + + r = sd_netlink_open(&rtnl); + if (r < 0) + return log_error_errno(r, "Failed to connect to netlink: %m"); + + r = add_veth(rtnl, pid, n, a, &mac_host, "host0", &mac_container); + if (r < 0) + return r; + + u = if_nametoindex(n); /* We don't need to use rtnl_resolve_ifname() here because the + * name we assigned is always the main name. */ + if (u == 0) + return log_error_errno(errno, "Failed to resolve interface %s: %m", n); + + strcpy(iface_name, n); + return (int) u; +} + +int setup_veth_extra( + const char *machine_name, + pid_t pid, + char **pairs) { + + _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL; + uint64_t idx = 0; + int r; + + assert(machine_name); + assert(pid > 0); + + if (strv_isempty(pairs)) + return 0; + + r = sd_netlink_open(&rtnl); + if (r < 0) + return log_error_errno(r, "Failed to connect to netlink: %m"); + + STRV_FOREACH_PAIR(a, b, pairs) { + struct ether_addr mac_host, mac_container; + + r = generate_mac(machine_name, &mac_container, VETH_EXTRA_CONTAINER_HASH_KEY, idx); + if (r < 0) + return log_error_errno(r, "Failed to generate predictable MAC address for container side of extra veth link: %m"); + + r = generate_mac(machine_name, &mac_host, VETH_EXTRA_HOST_HASH_KEY, idx); + if (r < 0) + return log_error_errno(r, "Failed to generate predictable MAC address for host side of extra veth link: %m"); + + r = add_veth(rtnl, pid, *a, NULL, &mac_host, *b, &mac_container); + if (r < 0) + return r; + + idx++; + } + + return 0; +} + +static int join_bridge(sd_netlink *rtnl, const char *veth_name, const char *bridge_name) { + _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL; + int r, bridge_ifi; + + assert(rtnl); + assert(veth_name); + assert(bridge_name); + + bridge_ifi = rtnl_resolve_interface(&rtnl, bridge_name); + if (bridge_ifi < 0) + return bridge_ifi; + + r = sd_rtnl_message_new_link(rtnl, &m, RTM_SETLINK, 0); + if (r < 0) + return r; + + r = sd_rtnl_message_link_set_flags(m, IFF_UP, IFF_UP); + if (r < 0) + return r; + + r = sd_netlink_message_append_string(m, IFLA_IFNAME, veth_name); + if (r < 0) + return r; + + r = sd_netlink_message_append_u32(m, IFLA_MASTER, bridge_ifi); + if (r < 0) + return r; + + r = sd_netlink_call(rtnl, m, 0, NULL); + if (r < 0) + return r; + + return bridge_ifi; +} + +static int create_bridge(sd_netlink *rtnl, const char *bridge_name) { + _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL; + int r; + + r = sd_rtnl_message_new_link(rtnl, &m, RTM_NEWLINK, 0); + if (r < 0) + return r; + + r = sd_netlink_message_append_string(m, IFLA_IFNAME, bridge_name); + if (r < 0) + return r; + + r = sd_netlink_message_open_container(m, IFLA_LINKINFO); + if (r < 0) + return r; + + r = sd_netlink_message_open_container_union(m, IFLA_INFO_DATA, "bridge"); + if (r < 0) + return r; + + r = sd_netlink_message_close_container(m); + if (r < 0) + return r; + + r = sd_netlink_message_close_container(m); + if (r < 0) + return r; + + r = sd_netlink_call(rtnl, m, 0, NULL); + if (r < 0) + return r; + + return 0; +} + +int setup_bridge(const char *veth_name, const char *bridge_name, bool create) { + _cleanup_(release_lock_file) LockFile bridge_lock = LOCK_FILE_INIT; + _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL; + int r, bridge_ifi; + unsigned n = 0; + + assert(veth_name); + assert(bridge_name); + + r = sd_netlink_open(&rtnl); + if (r < 0) + return log_error_errno(r, "Failed to connect to netlink: %m"); + + if (create) { + /* We take a system-wide lock here, so that we can safely check whether there's still a member in the + * bridge before removing it, without risking interference from other nspawn instances. */ + + r = make_lock_file("/run/systemd/nspawn-network-zone", LOCK_EX, &bridge_lock); + if (r < 0) + return log_error_errno(r, "Failed to take network zone lock: %m"); + } + + for (;;) { + bridge_ifi = join_bridge(rtnl, veth_name, bridge_name); + if (bridge_ifi >= 0) + return bridge_ifi; + if (bridge_ifi != -ENODEV || !create || n > 10) + return log_error_errno(bridge_ifi, "Failed to add interface %s to bridge %s: %m", veth_name, bridge_name); + + /* Count attempts, so that we don't enter an endless loop here. */ + n++; + + /* The bridge doesn't exist yet. Let's create it */ + r = create_bridge(rtnl, bridge_name); + if (r < 0) + return log_error_errno(r, "Failed to create bridge interface %s: %m", bridge_name); + + /* Try again, now that the bridge exists */ + } +} + +int remove_bridge(const char *bridge_name) { + _cleanup_(release_lock_file) LockFile bridge_lock = LOCK_FILE_INIT; + _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL; + const char *path; + int r; + + /* Removes the specified bridge, but only if it is currently empty */ + + if (isempty(bridge_name)) + return 0; + + r = make_lock_file("/run/systemd/nspawn-network-zone", LOCK_EX, &bridge_lock); + if (r < 0) + return log_error_errno(r, "Failed to take network zone lock: %m"); + + path = strjoina("/sys/class/net/", bridge_name, "/brif"); + + r = dir_is_empty(path, /* ignore_hidden_or_backup= */ false); + if (r == -ENOENT) /* Already gone? */ + return 0; + if (r < 0) + return log_error_errno(r, "Can't detect if bridge %s is empty: %m", bridge_name); + if (r == 0) /* Still populated, leave it around */ + return 0; + + r = sd_netlink_open(&rtnl); + if (r < 0) + return log_error_errno(r, "Failed to connect to netlink: %m"); + + return remove_one_link(rtnl, bridge_name); +} + +int test_network_interface_initialized(const char *name) { + _cleanup_(sd_device_unrefp) sd_device *d = NULL; + int r; + + if (!udev_available()) + return 0; + + /* udev should be around. */ + + r = sd_device_new_from_ifname(&d, name); + if (r < 0) + return log_error_errno(r, "Failed to get device %s: %m", name); + + r = sd_device_get_is_initialized(d); + if (r < 0) + return log_error_errno(r, "Failed to determine whether interface %s is initialized: %m", name); + if (r == 0) + return log_error_errno(SYNTHETIC_ERRNO(EBUSY), "Network interface %s is not initialized yet.", name); + + r = device_is_renaming(d); + if (r < 0) + return log_error_errno(r, "Failed to determine the interface %s is being renamed: %m", name); + if (r > 0) + return log_error_errno(SYNTHETIC_ERRNO(EBUSY), "Interface %s is being renamed.", name); + + return 0; +} + +int move_network_interfaces(int netns_fd, char **ifaces) { + _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL; + int r; + + if (strv_isempty(ifaces)) + return 0; + + r = sd_netlink_open(&rtnl); + if (r < 0) + return log_error_errno(r, "Failed to connect to netlink: %m"); + + STRV_FOREACH(i, ifaces) { + _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL; + int ifi; + + ifi = rtnl_resolve_interface_or_warn(&rtnl, *i); + if (ifi < 0) + return ifi; + + r = sd_rtnl_message_new_link(rtnl, &m, RTM_SETLINK, ifi); + if (r < 0) + return log_error_errno(r, "Failed to allocate netlink message: %m"); + + r = sd_netlink_message_append_u32(m, IFLA_NET_NS_FD, netns_fd); + if (r < 0) + return log_error_errno(r, "Failed to append namespace fd to netlink message: %m"); + + r = sd_netlink_call(rtnl, m, 0, NULL); + if (r < 0) + return log_error_errno(r, "Failed to move interface %s to namespace: %m", *i); + } + + return 0; +} + +int setup_macvlan(const char *machine_name, pid_t pid, char **ifaces) { + _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL; + unsigned idx = 0; + int r; + + if (strv_isempty(ifaces)) + return 0; + + r = sd_netlink_open(&rtnl); + if (r < 0) + return log_error_errno(r, "Failed to connect to netlink: %m"); + + STRV_FOREACH(i, ifaces) { + _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL; + _cleanup_free_ char *n = NULL, *a = NULL; + struct ether_addr mac; + int ifi; + + ifi = rtnl_resolve_interface_or_warn(&rtnl, *i); + if (ifi < 0) + return ifi; + + r = generate_mac(machine_name, &mac, MACVLAN_HASH_KEY, idx++); + if (r < 0) + return log_error_errno(r, "Failed to create MACVLAN MAC address: %m"); + + r = sd_rtnl_message_new_link(rtnl, &m, RTM_NEWLINK, 0); + if (r < 0) + return log_error_errno(r, "Failed to allocate netlink message: %m"); + + r = sd_netlink_message_append_u32(m, IFLA_LINK, ifi); + if (r < 0) + return log_error_errno(r, "Failed to add netlink interface index: %m"); + + n = strjoin("mv-", *i); + if (!n) + return log_oom(); + + r = shorten_ifname(n); + if (r > 0) { + a = strjoin("mv-", *i); + if (!a) + return log_oom(); + } + + r = sd_netlink_message_append_string(m, IFLA_IFNAME, n); + if (r < 0) + return log_error_errno(r, "Failed to add netlink interface name: %m"); + + r = sd_netlink_message_append_ether_addr(m, IFLA_ADDRESS, &mac); + if (r < 0) + return log_error_errno(r, "Failed to add netlink MAC address: %m"); + + r = sd_netlink_message_append_u32(m, IFLA_NET_NS_PID, pid); + if (r < 0) + return log_error_errno(r, "Failed to add netlink namespace field: %m"); + + r = sd_netlink_message_open_container(m, IFLA_LINKINFO); + if (r < 0) + return log_error_errno(r, "Failed to open netlink container: %m"); + + r = sd_netlink_message_open_container_union(m, IFLA_INFO_DATA, "macvlan"); + if (r < 0) + return log_error_errno(r, "Failed to open netlink container: %m"); + + r = sd_netlink_message_append_u32(m, IFLA_MACVLAN_MODE, MACVLAN_MODE_BRIDGE); + if (r < 0) + return log_error_errno(r, "Failed to append macvlan mode: %m"); + + r = sd_netlink_message_close_container(m); + if (r < 0) + return log_error_errno(r, "Failed to close netlink container: %m"); + + r = sd_netlink_message_close_container(m); + if (r < 0) + return log_error_errno(r, "Failed to close netlink container: %m"); + + r = sd_netlink_call(rtnl, m, 0, NULL); + if (r < 0) + return log_error_errno(r, "Failed to add new macvlan interfaces: %m"); + + (void) set_alternative_ifname(rtnl, n, a); + } + + return 0; +} + +int setup_ipvlan(const char *machine_name, pid_t pid, char **ifaces) { + _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL; + int r; + + if (strv_isempty(ifaces)) + return 0; + + r = sd_netlink_open(&rtnl); + if (r < 0) + return log_error_errno(r, "Failed to connect to netlink: %m"); + + STRV_FOREACH(i, ifaces) { + _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL; + _cleanup_free_ char *n = NULL, *a = NULL; + int ifi; + + ifi = rtnl_resolve_interface_or_warn(&rtnl, *i); + if (ifi < 0) + return ifi; + + r = sd_rtnl_message_new_link(rtnl, &m, RTM_NEWLINK, 0); + if (r < 0) + return log_error_errno(r, "Failed to allocate netlink message: %m"); + + r = sd_netlink_message_append_u32(m, IFLA_LINK, ifi); + if (r < 0) + return log_error_errno(r, "Failed to add netlink interface index: %m"); + + n = strjoin("iv-", *i); + if (!n) + return log_oom(); + + r = shorten_ifname(n); + if (r > 0) { + a = strjoin("iv-", *i); + if (!a) + return log_oom(); + } + + r = sd_netlink_message_append_string(m, IFLA_IFNAME, n); + if (r < 0) + return log_error_errno(r, "Failed to add netlink interface name: %m"); + + r = sd_netlink_message_append_u32(m, IFLA_NET_NS_PID, pid); + if (r < 0) + return log_error_errno(r, "Failed to add netlink namespace field: %m"); + + r = sd_netlink_message_open_container(m, IFLA_LINKINFO); + if (r < 0) + return log_error_errno(r, "Failed to open netlink container: %m"); + + r = sd_netlink_message_open_container_union(m, IFLA_INFO_DATA, "ipvlan"); + if (r < 0) + return log_error_errno(r, "Failed to open netlink container: %m"); + + r = sd_netlink_message_append_u16(m, IFLA_IPVLAN_MODE, IPVLAN_MODE_L2); + if (r < 0) + return log_error_errno(r, "Failed to add ipvlan mode: %m"); + + r = sd_netlink_message_close_container(m); + if (r < 0) + return log_error_errno(r, "Failed to close netlink container: %m"); + + r = sd_netlink_message_close_container(m); + if (r < 0) + return log_error_errno(r, "Failed to close netlink container: %m"); + + r = sd_netlink_call(rtnl, m, 0, NULL); + if (r < 0) + return log_error_errno(r, "Failed to add new ipvlan interfaces: %m"); + + (void) set_alternative_ifname(rtnl, n, a); + } + + return 0; +} + +int veth_extra_parse(char ***l, const char *p) { + _cleanup_free_ char *a = NULL, *b = NULL; + int r; + + r = extract_first_word(&p, &a, ":", EXTRACT_DONT_COALESCE_SEPARATORS); + if (r < 0) + return r; + if (r == 0 || !ifname_valid(a)) + return -EINVAL; + + r = extract_first_word(&p, &b, ":", EXTRACT_DONT_COALESCE_SEPARATORS); + if (r < 0) + return r; + if (r == 0 || !ifname_valid(b)) { + free(b); + b = strdup(a); + if (!b) + return -ENOMEM; + } + + if (p) + return -EINVAL; + + r = strv_push_pair(l, a, b); + if (r < 0) + return -ENOMEM; + + a = b = NULL; + return 0; +} + +int remove_veth_links(const char *primary, char **pairs) { + _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL; + int r; + + /* In some cases the kernel might pin the veth links between host and container even after the namespace + * died. Hence, let's better remove them explicitly too. */ + + if (isempty(primary) && strv_isempty(pairs)) + return 0; + + r = sd_netlink_open(&rtnl); + if (r < 0) + return log_error_errno(r, "Failed to connect to netlink: %m"); + + remove_one_link(rtnl, primary); + + STRV_FOREACH_PAIR(a, b, pairs) + remove_one_link(rtnl, *a); + + return 0; +} diff --git a/src/nspawn/nspawn-network.h b/src/nspawn/nspawn-network.h new file mode 100644 index 0000000..5c2d983 --- /dev/null +++ b/src/nspawn/nspawn-network.h @@ -0,0 +1,23 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ +#pragma once + +#include <net/if.h> +#include <stdbool.h> +#include <sys/types.h> + +int test_network_interface_initialized(const char *name); + +int setup_veth(const char *machine_name, pid_t pid, char iface_name[IFNAMSIZ], bool bridge); +int setup_veth_extra(const char *machine_name, pid_t pid, char **pairs); + +int setup_bridge(const char *veth_name, const char *bridge_name, bool create); +int remove_bridge(const char *bridge_name); + +int setup_macvlan(const char *machine_name, pid_t pid, char **ifaces); +int setup_ipvlan(const char *machine_name, pid_t pid, char **ifaces); + +int move_network_interfaces(int netns_fd, char **ifaces); + +int veth_extra_parse(char ***l, const char *p); + +int remove_veth_links(const char *primary, char **pairs); diff --git a/src/nspawn/nspawn-oci.c b/src/nspawn/nspawn-oci.c new file mode 100644 index 0000000..c8ed3f1 --- /dev/null +++ b/src/nspawn/nspawn-oci.c @@ -0,0 +1,2207 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include <linux/oom.h> +#if HAVE_SECCOMP +#include <seccomp.h> +#endif + +#include "bus-util.h" +#include "cap-list.h" +#include "cpu-set-util.h" +#include "device-util.h" +#include "devnum-util.h" +#include "env-util.h" +#include "format-util.h" +#include "fs-util.h" +#include "hostname-util.h" +#include "json.h" +#include "missing_sched.h" +#include "nspawn-oci.h" +#include "path-util.h" +#include "rlimit-util.h" +#if HAVE_SECCOMP +#include "seccomp-util.h" +#endif +#include "stdio-util.h" +#include "string-util.h" +#include "strv.h" +#include "user-util.h" + +/* TODO: + * OCI runtime tool implementation + * hooks + * + * Spec issues: + * + * How is RLIM_INFINITY supposed to be encoded? + * configured effective caps is bullshit, as execv() corrupts it anyway + * pipes bind mounted is *very* different from pipes newly created, comments regarding bind mount or not are bogus + * annotation values structured? or string? + * configurable file system namespace path, but then also root path? wtf? + * apply sysctl inside of the container? or outside? + * how is unlimited pids tasks limit to be encoded? + * what are the defaults for caps if not specified? + * what are the default uid/gid mappings if one is missing but the other set, or when user ns is on but no namespace configured + * the source field of "mounts" is really weird, as it cannot realistically be relative to the bundle, since we never know if that's what the fs wants + * spec contradicts itself on the mount "type" field, as the example uses "bind" as type, but it's not listed in /proc/filesystem, and is something made up by /bin/mount + * if type of mount is left out, what shall be assumed? "bind"? + * readonly mounts is entirely redundant? + * should escaping be applied when joining mount options with ","? + * devices cgroup support is bogus, "allow" and "deny" on the kernel level is about adding/removing entries, not about access + * spec needs to say that "rwm" devices cgroup combination can't be the empty string + * cgrouspv1 crap: kernel, kernelTCP, swappiness, disableOOMKiller, swap, devices, leafWeight + * general: it shouldn't leak lower level abstractions this obviously + * unmanagable cgroups stuff: realtimeRuntime/realtimePeriod + * needs to say what happense when some option is not specified, i.e. which defaults apply + * no architecture? no personality? + * seccomp example and logic is simply broken: there's no constant "SCMP_ACT_ERRNO". + * spec should say what to do with unknown props + * /bin/mount regarding NFS and FUSE required? + * what does terminal=false mean? + * sysctl inside or outside? allow-listing? + * swapiness typo -> swappiness + * + * Unsupported: + * + * apparmorProfile + * selinuxLabel + mountLabel + * hugepageLimits + * network + * rdma + * intelRdt + * swappiness, disableOOMKiller, kernel, kernelTCP, leafWeight (because it's dead, cgroupsv2 can't do it and hence systemd neither) + * + * Non-slice cgroup paths + * Propagation that is not slave + shared + * more than one uid/gid mapping, mappings with a container base != 0, or non-matching uid/gid mappings + * device cgroups access = false items that are not catchall + * device cgroups matches where minor is specified, but major isn't. similar where major is specified but char/block is not. also, any match that only has a type set that has less than "rwm" set. also, any entry that has none of rwm set. + * + */ + +static int oci_unexpected(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + return json_log(v, flags, SYNTHETIC_ERRNO(EINVAL), + "Unexpected OCI element '%s' of type '%s'.", name, json_variant_type_to_string(json_variant_type(v))); +} + +static int oci_unsupported(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + return json_log(v, flags, SYNTHETIC_ERRNO(EOPNOTSUPP), + "Unsupported OCI element '%s' of type '%s'.", name, json_variant_type_to_string(json_variant_type(v))); +} + +static int oci_terminal(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + Settings *s = userdata; + + /* If not specified, or set to true, we'll default to either an interactive or a read-only + * console. If specified as false, we'll forcibly move to "pipe" mode though. */ + s->console_mode = json_variant_boolean(v) ? _CONSOLE_MODE_INVALID : CONSOLE_PIPE; + return 0; +} + +static int oci_console_dimension(const char *name, JsonVariant *variant, JsonDispatchFlags flags, void *userdata) { + unsigned *u = ASSERT_PTR(userdata); + uint64_t k; + + k = json_variant_unsigned(variant); + if (k == 0) + return json_log(variant, flags, SYNTHETIC_ERRNO(ERANGE), + "Console size field '%s' is too small.", strna(name)); + if (k > USHRT_MAX) /* TIOCSWINSZ's struct winsize uses "unsigned short" for width and height */ + return json_log(variant, flags, SYNTHETIC_ERRNO(ERANGE), + "Console size field '%s' is too large.", strna(name)); + + *u = (unsigned) k; + return 0; +} + +static int oci_console_size(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + + static const JsonDispatch table[] = { + { "height", JSON_VARIANT_UNSIGNED, oci_console_dimension, offsetof(Settings, console_height), JSON_MANDATORY }, + { "width", JSON_VARIANT_UNSIGNED, oci_console_dimension, offsetof(Settings, console_width), JSON_MANDATORY }, + {} + }; + + return json_dispatch(v, table, oci_unexpected, flags, userdata); +} + +static int oci_absolute_path(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + char **p = ASSERT_PTR(userdata); + const char *n; + + n = json_variant_string(v); + + if (!path_is_absolute(n)) + return json_log(v, flags, SYNTHETIC_ERRNO(EINVAL), + "Path in JSON field '%s' is not absolute: %s", strna(name), n); + + return free_and_strdup_warn(p, n); +} + +static int oci_env(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + char ***l = ASSERT_PTR(userdata); + JsonVariant *e; + int r; + + JSON_VARIANT_ARRAY_FOREACH(e, v) { + const char *n; + + if (!json_variant_is_string(e)) + return json_log(e, flags, SYNTHETIC_ERRNO(EINVAL), + "Environment array contains non-string."); + + assert_se(n = json_variant_string(e)); + + if (!env_assignment_is_valid(n)) + return json_log(e, flags, SYNTHETIC_ERRNO(EINVAL), + "Environment assignment not valid: %s", n); + + r = strv_extend(l, n); + if (r < 0) + return log_oom(); + } + + return 0; +} + +static int oci_args(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + _cleanup_strv_free_ char **l = NULL; + char ***value = ASSERT_PTR(userdata); + int r; + + r = json_variant_strv(v, &l); + if (r < 0) + return json_log(v, flags, r, "Cannot parse arguments as list of strings: %m"); + + if (strv_isempty(l)) + return json_log(v, flags, SYNTHETIC_ERRNO(EINVAL), + "Argument list empty, refusing."); + + if (isempty(l[0])) + return json_log(v, flags, SYNTHETIC_ERRNO(EINVAL), + "Executable name is empty, refusing."); + + return strv_free_and_replace(*value, l); +} + +static int oci_rlimit_type(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + const char *z; + int t, *type = userdata; + + assert_se(type); + + z = startswith(json_variant_string(v), "RLIMIT_"); + if (!z) + return json_log(v, flags, SYNTHETIC_ERRNO(EINVAL), + "rlimit entry's name does not begin with 'RLIMIT_', refusing: %s", + json_variant_string(v)); + + t = rlimit_from_string(z); + if (t < 0) + return json_log(v, flags, t, + "rlimit name unknown: %s", json_variant_string(v)); + + *type = t; + return 0; +} + +static int oci_rlimit_value(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + rlim_t z, *value = ASSERT_PTR(userdata); + + if (json_variant_is_negative(v)) + z = RLIM_INFINITY; + else { + if (!json_variant_is_unsigned(v)) + return json_log(v, flags, SYNTHETIC_ERRNO(ERANGE), + "rlimits limit not unsigned, refusing."); + + z = (rlim_t) json_variant_unsigned(v); + + if ((uint64_t) z != json_variant_unsigned(v)) + return json_log(v, flags, SYNTHETIC_ERRNO(EINVAL), + "rlimits limit out of range, refusing."); + } + + *value = z; + return 0; +} + +static int oci_rlimits(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + + Settings *s = ASSERT_PTR(userdata); + JsonVariant *e; + int r; + + JSON_VARIANT_ARRAY_FOREACH(e, v) { + + struct rlimit_data { + int type; + rlim_t soft; + rlim_t hard; + } data = { + .type = -1, + .soft = RLIM_INFINITY, + .hard = RLIM_INFINITY, + }; + + static const JsonDispatch table[] = { + { "soft", JSON_VARIANT_NUMBER, oci_rlimit_value, offsetof(struct rlimit_data, soft), JSON_MANDATORY }, + { "hard", JSON_VARIANT_NUMBER, oci_rlimit_value, offsetof(struct rlimit_data, hard), JSON_MANDATORY }, + { "type", JSON_VARIANT_STRING, oci_rlimit_type, offsetof(struct rlimit_data, type), JSON_MANDATORY }, + {} + }; + + r = json_dispatch(e, table, oci_unexpected, flags, &data); + if (r < 0) + return r; + + assert(data.type >= 0); + assert(data.type < _RLIMIT_MAX); + + if (s->rlimit[data.type]) + return json_log(v, flags, SYNTHETIC_ERRNO(EINVAL), + "rlimits array contains duplicate entry, refusing."); + + s->rlimit[data.type] = new(struct rlimit, 1); + if (!s->rlimit[data.type]) + return log_oom(); + + *s->rlimit[data.type] = (struct rlimit) { + .rlim_cur = data.soft, + .rlim_max = data.hard, + }; + + } + return 0; +} + +static int oci_capability_array(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + uint64_t *mask = userdata, m = 0; + JsonVariant *e; + + JSON_VARIANT_ARRAY_FOREACH(e, v) { + const char *n; + int cap; + + if (!json_variant_is_string(e)) + return json_log(v, flags, SYNTHETIC_ERRNO(EINVAL), + "Entry in capabilities array is not a string."); + + assert_se(n = json_variant_string(e)); + + cap = capability_from_name(n); + if (cap < 0) + return json_log(v, flags, SYNTHETIC_ERRNO(EINVAL), + "Unknown capability: %s", n); + + m |= UINT64_C(1) << cap; + } + + if (*mask == UINT64_MAX) + *mask = m; + else + *mask |= m; + + return 0; +} + +static int oci_capabilities(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + + static const JsonDispatch table[] = { + { "effective", JSON_VARIANT_ARRAY, oci_capability_array, offsetof(CapabilityQuintet, effective) }, + { "bounding", JSON_VARIANT_ARRAY, oci_capability_array, offsetof(CapabilityQuintet, bounding) }, + { "inheritable", JSON_VARIANT_ARRAY, oci_capability_array, offsetof(CapabilityQuintet, inheritable) }, + { "permitted", JSON_VARIANT_ARRAY, oci_capability_array, offsetof(CapabilityQuintet, permitted) }, + { "ambient", JSON_VARIANT_ARRAY, oci_capability_array, offsetof(CapabilityQuintet, ambient) }, + {} + }; + + Settings *s = ASSERT_PTR(userdata); + int r; + + r = json_dispatch(v, table, oci_unexpected, flags, &s->full_capabilities); + if (r < 0) + return r; + + if (s->full_capabilities.bounding != UINT64_MAX) { + s->capability = s->full_capabilities.bounding; + s->drop_capability = ~s->full_capabilities.bounding; + } + + return 0; +} + +static int oci_oom_score_adj(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + Settings *s = ASSERT_PTR(userdata); + int64_t k; + + k = json_variant_integer(v); + if (k < OOM_SCORE_ADJ_MIN || k > OOM_SCORE_ADJ_MAX) + return json_log(v, flags, SYNTHETIC_ERRNO(EINVAL), + "oomScoreAdj value out of range: %" PRIi64, k); + + s->oom_score_adjust = (int) k; + s->oom_score_adjust_set = true; + + return 0; +} + +static int oci_uid_gid(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + uid_t *uid = userdata, u; + uint64_t k; + + assert(uid); + assert_cc(sizeof(uid_t) == sizeof(gid_t)); + + k = json_variant_unsigned(v); + u = (uid_t) k; + if ((uint64_t) u != k) + return json_log(v, flags, SYNTHETIC_ERRNO(EINVAL), + "UID/GID out of range: %" PRIu64, k); + + if (!uid_is_valid(u)) + return json_log(v, flags, SYNTHETIC_ERRNO(EINVAL), + "UID/GID is not valid: " UID_FMT, u); + + *uid = u; + return 0; +} + +static int oci_supplementary_gids(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + Settings *s = ASSERT_PTR(userdata); + JsonVariant *e; + int r; + + JSON_VARIANT_ARRAY_FOREACH(e, v) { + gid_t gid, *a; + + if (!json_variant_is_unsigned(e)) + return json_log(v, flags, SYNTHETIC_ERRNO(EINVAL), + "Supplementary GID entry is not a UID."); + + r = oci_uid_gid(name, e, flags, &gid); + if (r < 0) + return r; + + a = reallocarray(s->supplementary_gids, s->n_supplementary_gids + 1, sizeof(gid_t)); + if (!a) + return log_oom(); + + s->supplementary_gids = a; + s->supplementary_gids[s->n_supplementary_gids++] = gid; + } + + return 0; +} + +static int oci_user(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + static const JsonDispatch table[] = { + { "uid", JSON_VARIANT_UNSIGNED, oci_uid_gid, offsetof(Settings, uid), JSON_MANDATORY }, + { "gid", JSON_VARIANT_UNSIGNED, oci_uid_gid, offsetof(Settings, gid), JSON_MANDATORY }, + { "additionalGids", JSON_VARIANT_ARRAY, oci_supplementary_gids, 0, 0 }, + {} + }; + + return json_dispatch(v, table, oci_unexpected, flags, userdata); +} + +static int oci_process(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + + static const JsonDispatch table[] = { + { "terminal", JSON_VARIANT_BOOLEAN, oci_terminal, 0, 0 }, + { "consoleSize", JSON_VARIANT_OBJECT, oci_console_size, 0, 0 }, + { "cwd", JSON_VARIANT_STRING, oci_absolute_path, offsetof(Settings, working_directory), 0 }, + { "env", JSON_VARIANT_ARRAY, oci_env, offsetof(Settings, environment), 0 }, + { "args", JSON_VARIANT_ARRAY, oci_args, offsetof(Settings, parameters), 0 }, + { "rlimits", JSON_VARIANT_ARRAY, oci_rlimits, 0, 0 }, + { "apparmorProfile", JSON_VARIANT_STRING, oci_unsupported, 0, JSON_PERMISSIVE }, + { "capabilities", JSON_VARIANT_OBJECT, oci_capabilities, 0, 0 }, + { "noNewPrivileges", JSON_VARIANT_BOOLEAN, json_dispatch_boolean, offsetof(Settings, no_new_privileges), 0 }, + { "oomScoreAdj", JSON_VARIANT_INTEGER, oci_oom_score_adj, 0, 0 }, + { "selinuxLabel", JSON_VARIANT_STRING, oci_unsupported, 0, JSON_PERMISSIVE }, + { "user", JSON_VARIANT_OBJECT, oci_user, 0, 0 }, + {} + }; + + return json_dispatch(v, table, oci_unexpected, flags, userdata); +} + +static int oci_root(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + Settings *s = userdata; + int r; + + static const JsonDispatch table[] = { + { "path", JSON_VARIANT_STRING, json_dispatch_string, offsetof(Settings, root) }, + { "readonly", JSON_VARIANT_BOOLEAN, json_dispatch_boolean, offsetof(Settings, read_only) }, + {} + }; + + r = json_dispatch(v, table, oci_unexpected, flags, s); + if (r < 0) + return r; + + if (s->root && !path_is_absolute(s->root)) { + char *joined; + + joined = path_join(s->bundle, s->root); + if (!joined) + return log_oom(); + + free_and_replace(s->root, joined); + } + + return 0; +} + +static int oci_hostname(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + Settings *s = ASSERT_PTR(userdata); + const char *n; + + assert_se(n = json_variant_string(v)); + + if (!hostname_is_valid(n, 0)) + return json_log(v, flags, SYNTHETIC_ERRNO(EINVAL), + "Hostname string is not a valid hostname: %s", n); + + return free_and_strdup_warn(&s->hostname, n); +} + +static bool oci_exclude_mount(const char *path) { + + /* Returns "true" for all mounts we insist to mount on our own, and hence ignore the OCI data. */ + + if (PATH_IN_SET(path, + "/dev", + "/dev/mqueue", + "/dev/pts", + "/dev/shm", + "/proc", + "/proc/acpi", + "/proc/apm", + "/proc/asound", + "/proc/bus", + "/proc/fs", + "/proc/irq", + "/proc/kallsyms", + "/proc/kcore", + "/proc/keys", + "/proc/scsi", + "/proc/sys", + "/proc/sys/net", + "/proc/sysrq-trigger", + "/proc/timer_list", + "/run", + "/sys", + "/sys", + "/sys/fs/selinux", + "/tmp")) + return true; + + /* Similar, skip the whole /sys/fs/cgroups subtree */ + if (path_startswith(path, "/sys/fs/cgroup")) + return true; + + return false; +} + +typedef struct oci_mount_data { + char *destination; + char *source; + char *type; + char **options; +} oci_mount_data; + +static void cleanup_oci_mount_data(oci_mount_data *data) { + free(data->destination); + free(data->source); + strv_free(data->options); + free(data->type); +} + +static int oci_mounts(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + Settings *s = ASSERT_PTR(userdata); + JsonVariant *e; + int r; + + JSON_VARIANT_ARRAY_FOREACH(e, v) { + static const JsonDispatch table[] = { + { "destination", JSON_VARIANT_STRING, oci_absolute_path, offsetof(oci_mount_data, destination), JSON_MANDATORY }, + { "source", JSON_VARIANT_STRING, json_dispatch_string, offsetof(oci_mount_data, source), 0 }, + { "options", JSON_VARIANT_ARRAY, json_dispatch_strv, offsetof(oci_mount_data, options), 0, }, + { "type", JSON_VARIANT_STRING, json_dispatch_string, offsetof(oci_mount_data, type), 0 }, + {} + }; + + _cleanup_free_ char *joined_options = NULL; + CustomMount *m; + _cleanup_(cleanup_oci_mount_data) oci_mount_data data = {}; + + r = json_dispatch(e, table, oci_unexpected, flags, &data); + if (r < 0) + return r; + + if (!path_is_absolute(data.destination)) + return json_log(e, flags, SYNTHETIC_ERRNO(EINVAL), + "Mount destination not an absolute path: %s", data.destination); + + if (oci_exclude_mount(data.destination)) + continue; + + if (data.options) { + joined_options = strv_join(data.options, ","); + if (!joined_options) + return log_oom(); + } + + if (!data.type || streq(data.type, "bind")) { + if (data.source && !path_is_absolute(data.source)) { + char *joined; + + joined = path_join(s->bundle, data.source); + if (!joined) + return log_oom(); + + free_and_replace(data.source, joined); + } + + data.type = mfree(data.type); + + m = custom_mount_add(&s->custom_mounts, &s->n_custom_mounts, CUSTOM_MOUNT_BIND); + } else + m = custom_mount_add(&s->custom_mounts, &s->n_custom_mounts, CUSTOM_MOUNT_ARBITRARY); + if (!m) + return log_oom(); + + m->destination = TAKE_PTR(data.destination); + m->source = TAKE_PTR(data.source); + m->options = TAKE_PTR(joined_options); + m->type_argument = TAKE_PTR(data.type); + } + + return 0; +} + +static int oci_namespace_type(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + unsigned long *nsflags = ASSERT_PTR(userdata); + const char *n; + + assert_se(n = json_variant_string(v)); + + /* We don't use namespace_flags_from_string() here, as the OCI spec uses slightly different names than the + * kernel here. */ + if (streq(n, "pid")) + *nsflags = CLONE_NEWPID; + else if (streq(n, "network")) + *nsflags = CLONE_NEWNET; + else if (streq(n, "mount")) + *nsflags = CLONE_NEWNS; + else if (streq(n, "ipc")) + *nsflags = CLONE_NEWIPC; + else if (streq(n, "uts")) + *nsflags = CLONE_NEWUTS; + else if (streq(n, "user")) + *nsflags = CLONE_NEWUSER; + else if (streq(n, "cgroup")) + *nsflags = CLONE_NEWCGROUP; + else + return json_log(v, flags, SYNTHETIC_ERRNO(EINVAL), + "Unknown namespace type, refusing: %s", n); + + return 0; +} + +static int oci_namespaces(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + Settings *s = userdata; + unsigned long n = 0; + JsonVariant *e; + int r; + + assert_se(s); + + JSON_VARIANT_ARRAY_FOREACH(e, v) { + + struct namespace_data { + unsigned long type; + char *path; + } data = {}; + + static const JsonDispatch table[] = { + { "type", JSON_VARIANT_STRING, oci_namespace_type, offsetof(struct namespace_data, type), JSON_MANDATORY }, + { "path", JSON_VARIANT_STRING, oci_absolute_path, offsetof(struct namespace_data, path), 0 }, + {} + }; + + r = json_dispatch(e, table, oci_unexpected, flags, &data); + if (r < 0) { + free(data.path); + return r; + } + + if (data.path) { + if (data.type != CLONE_NEWNET) { + free(data.path); + return json_log(e, flags, SYNTHETIC_ERRNO(EOPNOTSUPP), + "Specifying namespace path for non-network namespace is not supported."); + } + + if (s->network_namespace_path) { + free(data.path); + return json_log(e, flags, SYNTHETIC_ERRNO(EINVAL), + "Network namespace path specified more than once, refusing."); + } + + free(s->network_namespace_path); + s->network_namespace_path = data.path; + } + + if (FLAGS_SET(n, data.type)) + return json_log(e, flags, SYNTHETIC_ERRNO(EINVAL), + "Duplicate namespace specification, refusing."); + + n |= data.type; + } + + if (!FLAGS_SET(n, CLONE_NEWNS)) + return json_log(v, flags, SYNTHETIC_ERRNO(EOPNOTSUPP), + "Containers without a mount namespace aren't supported."); + + s->private_network = FLAGS_SET(n, CLONE_NEWNET); + s->userns_mode = FLAGS_SET(n, CLONE_NEWUSER) ? USER_NAMESPACE_FIXED : USER_NAMESPACE_NO; + s->use_cgns = FLAGS_SET(n, CLONE_NEWCGROUP); + + s->clone_ns_flags = n & (CLONE_NEWIPC|CLONE_NEWPID|CLONE_NEWUTS); + + return 0; +} + +static int oci_uid_gid_range(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + uid_t *uid = userdata, u; + uint64_t k; + + assert(uid); + assert_cc(sizeof(uid_t) == sizeof(gid_t)); + + /* This is very much like oci_uid_gid(), except the checks are a bit different, as this is a UID range rather + * than a specific UID, and hence UID_INVALID has no special significance. OTOH a range of zero makes no + * sense. */ + + k = json_variant_unsigned(v); + u = (uid_t) k; + if ((uint64_t) u != k) + return json_log(v, flags, SYNTHETIC_ERRNO(ERANGE), + "UID/GID out of range: %" PRIu64, k); + if (u == 0) + return json_log(v, flags, SYNTHETIC_ERRNO(ERANGE), + "UID/GID range can't be zero."); + + *uid = u; + return 0; +} + +static int oci_uid_gid_mappings(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + struct mapping_data { + uid_t host_id; + uid_t container_id; + uid_t range; + } data = { + .host_id = UID_INVALID, + .container_id = UID_INVALID, + .range = 0, + }; + + static const JsonDispatch table[] = { + { "containerID", JSON_VARIANT_UNSIGNED, oci_uid_gid, offsetof(struct mapping_data, container_id), JSON_MANDATORY }, + { "hostID", JSON_VARIANT_UNSIGNED, oci_uid_gid, offsetof(struct mapping_data, host_id), JSON_MANDATORY }, + { "size", JSON_VARIANT_UNSIGNED, oci_uid_gid_range, offsetof(struct mapping_data, range), JSON_MANDATORY }, + {} + }; + + Settings *s = ASSERT_PTR(userdata); + JsonVariant *e; + int r; + + if (json_variant_elements(v) == 0) + return 0; + + if (json_variant_elements(v) > 1) + return json_log(v, flags, SYNTHETIC_ERRNO(EOPNOTSUPP), + "UID/GID mappings with more than one entry are not supported."); + + assert_se(e = json_variant_by_index(v, 0)); + + r = json_dispatch(e, table, oci_unexpected, flags, &data); + if (r < 0) + return r; + + if (data.host_id + data.range < data.host_id || + data.container_id + data.range < data.container_id) + return json_log(v, flags, SYNTHETIC_ERRNO(EINVAL), + "UID/GID range goes beyond UID/GID validity range, refusing."); + + if (data.container_id != 0) + return json_log(v, flags, SYNTHETIC_ERRNO(EOPNOTSUPP), + "UID/GID mappings with a non-zero container base are not supported."); + + if (data.range < 0x10000) + json_log(v, flags|JSON_WARNING, 0, + "UID/GID mapping with less than 65536 UID/GIDS set up, you are looking for trouble."); + + if (s->uid_range != UID_INVALID && + (s->uid_shift != data.host_id || s->uid_range != data.range)) + return json_log(v, flags, SYNTHETIC_ERRNO(EOPNOTSUPP), + "Non-matching UID and GID mappings are not supported."); + + s->uid_shift = data.host_id; + s->uid_range = data.range; + + return 0; +} + +static int oci_device_type(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + mode_t *mode = ASSERT_PTR(userdata); + const char *t; + + assert_se(t = json_variant_string(v)); + + if (STR_IN_SET(t, "c", "u")) + *mode = (*mode & ~S_IFMT) | S_IFCHR; + else if (streq(t, "b")) + *mode = (*mode & ~S_IFMT) | S_IFBLK; + else if (streq(t, "p")) + *mode = (*mode & ~S_IFMT) | S_IFIFO; + else + return json_log(v, flags, SYNTHETIC_ERRNO(EINVAL), + "Unknown device type: %s", t); + + return 0; +} + +static int oci_device_major(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + unsigned *u = userdata; + uint64_t k; + + assert_se(u); + + k = json_variant_unsigned(v); + if (!DEVICE_MAJOR_VALID(k)) + return json_log(v, flags, SYNTHETIC_ERRNO(ERANGE), + "Device major %" PRIu64 " out of range.", k); + + *u = (unsigned) k; + return 0; +} + +static int oci_device_minor(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + unsigned *u = userdata; + uint64_t k; + + assert_se(u); + + k = json_variant_unsigned(v); + if (!DEVICE_MINOR_VALID(k)) + return json_log(v, flags, SYNTHETIC_ERRNO(ERANGE), + "Device minor %" PRIu64 " out of range.", k); + + *u = (unsigned) k; + return 0; +} + +static int oci_device_file_mode(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + mode_t *mode = userdata, m; + uint64_t k; + + assert(mode); + + k = json_variant_unsigned(v); + m = (mode_t) k; + + if ((m & ~07777) != 0 || (uint64_t) m != k) + return json_log(v, flags, SYNTHETIC_ERRNO(ERANGE), + "fileMode out of range, refusing."); + + *mode = (*mode & ~07777) | m; + return 0; +} + +static int oci_devices(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + Settings *s = ASSERT_PTR(userdata); + JsonVariant *e; + int r; + + JSON_VARIANT_ARRAY_FOREACH(e, v) { + + static const JsonDispatch table[] = { + { "type", JSON_VARIANT_STRING, oci_device_type, offsetof(DeviceNode, mode), JSON_MANDATORY }, + { "path", JSON_VARIANT_STRING, oci_absolute_path, offsetof(DeviceNode, path), JSON_MANDATORY }, + { "major", JSON_VARIANT_UNSIGNED, oci_device_major, offsetof(DeviceNode, major), 0 }, + { "minor", JSON_VARIANT_UNSIGNED, oci_device_minor, offsetof(DeviceNode, minor), 0 }, + { "fileMode", JSON_VARIANT_UNSIGNED, oci_device_file_mode, offsetof(DeviceNode, mode), 0 }, + { "uid", JSON_VARIANT_UNSIGNED, oci_uid_gid, offsetof(DeviceNode, uid), 0 }, + { "gid", JSON_VARIANT_UNSIGNED, oci_uid_gid, offsetof(DeviceNode, gid), 0 }, + {} + }; + + DeviceNode *node, *nodes; + + nodes = reallocarray(s->extra_nodes, s->n_extra_nodes + 1, sizeof(DeviceNode)); + if (!nodes) + return log_oom(); + + s->extra_nodes = nodes; + + node = nodes + s->n_extra_nodes; + *node = (DeviceNode) { + .uid = UID_INVALID, + .gid = GID_INVALID, + .major = UINT_MAX, + .minor = UINT_MAX, + .mode = 0644, + }; + + r = json_dispatch(e, table, oci_unexpected, flags, node); + if (r < 0) + goto fail_element; + + if (S_ISCHR(node->mode) || S_ISBLK(node->mode)) { + _cleanup_free_ char *path = NULL; + + if (node->major == UINT_MAX || node->minor == UINT_MAX) { + r = json_log(e, flags, SYNTHETIC_ERRNO(EINVAL), + "Major/minor required when device node is device node"); + goto fail_element; + } + + /* Suppress a couple of implicit device nodes */ + r = devname_from_devnum(node->mode, makedev(node->major, node->minor), &path); + if (r < 0) + json_log(e, flags|JSON_DEBUG, r, "Failed to resolve device node %u:%u, ignoring: %m", node->major, node->minor); + else { + if (PATH_IN_SET(path, + "/dev/null", + "/dev/zero", + "/dev/full", + "/dev/random", + "/dev/urandom", + "/dev/tty", + "/dev/net/tun", + "/dev/ptmx", + "/dev/pts/ptmx", + "/dev/console")) { + + json_log(e, flags|JSON_DEBUG, 0, "Ignoring devices item for device '%s', as it is implicitly created anyway.", path); + free(node->path); + continue; + } + } + } + + s->n_extra_nodes++; + continue; + + fail_element: + free(node->path); + return r; + } + + return 0; +} + +static int oci_cgroups_path(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + _cleanup_free_ char *slice = NULL, *backwards = NULL; + Settings *s = ASSERT_PTR(userdata); + const char *p; + int r; + + assert_se(p = json_variant_string(v)); + + r = cg_path_get_slice(p, &slice); + if (r < 0) + return json_log(v, flags, r, "Couldn't derive slice unit name from path '%s': %m", p); + + r = cg_slice_to_path(slice, &backwards); + if (r < 0) + return json_log(v, flags, r, "Couldn't convert slice unit name '%s' back to path: %m", slice); + + if (!path_equal(backwards, p)) + return json_log(v, flags, SYNTHETIC_ERRNO(EINVAL), + "Control group path '%s' does not refer to slice unit, refusing.", p); + + free_and_replace(s->slice, slice); + return 0; +} + +static int oci_cgroup_device_type(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + mode_t *mode = userdata; + const char *n; + + assert_se(n = json_variant_string(v)); + + if (streq(n, "c")) + *mode = S_IFCHR; + else if (streq(n, "b")) + *mode = S_IFBLK; + else + return json_log(v, flags, SYNTHETIC_ERRNO(EINVAL), + "Control group device type unknown: %s", n); + + return 0; +} + +struct device_data { + bool allow; + bool r; + bool w; + bool m; + mode_t type; + unsigned major; + unsigned minor; +}; + +static int oci_cgroup_device_access(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + struct device_data *d = userdata; + bool r = false, w = false, m = false; + const char *s; + size_t i; + + assert_se(s = json_variant_string(v)); + + for (i = 0; s[i]; i++) + if (s[i] == 'r') + r = true; + else if (s[i] == 'w') + w = true; + else if (s[i] == 'm') + m = true; + else + return json_log(v, flags, SYNTHETIC_ERRNO(EINVAL), + "Unknown device access character '%c'.", s[i]); + + d->r = r; + d->w = w; + d->m = m; + + return 0; +} + +static int oci_cgroup_devices(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + + _cleanup_free_ struct device_data *list = NULL; + Settings *s = ASSERT_PTR(userdata); + size_t n_list = 0, i; + bool noop = false; + JsonVariant *e; + int r; + + JSON_VARIANT_ARRAY_FOREACH(e, v) { + + struct device_data data = { + .major = UINT_MAX, + .minor = UINT_MAX, + }, *a; + + static const JsonDispatch table[] = { + { "allow", JSON_VARIANT_BOOLEAN, json_dispatch_boolean, offsetof(struct device_data, allow), JSON_MANDATORY }, + { "type", JSON_VARIANT_STRING, oci_cgroup_device_type, offsetof(struct device_data, type), 0 }, + { "major", JSON_VARIANT_UNSIGNED, oci_device_major, offsetof(struct device_data, major), 0 }, + { "minor", JSON_VARIANT_UNSIGNED, oci_device_minor, offsetof(struct device_data, minor), 0 }, + { "access", JSON_VARIANT_STRING, oci_cgroup_device_access, 0, 0 }, + {} + }; + + r = json_dispatch(e, table, oci_unexpected, flags, &data); + if (r < 0) + return r; + + if (!data.allow) { + /* The fact that OCI allows 'deny' entries makes really no sense, as 'allow' + * vs. 'deny' for the devices cgroup controller is really not about allow-listing and + * deny-listing but about adding and removing entries from the allow list. Since we + * always start out with an empty allow list we hence ignore the whole thing, as + * removing entries which don't exist make no sense. We'll log about this, since this + * is really borked in the spec, with one exception: the entry that's supposed to + * drop the kernel's default we ignore silently */ + + if (!data.r || !data.w || !data.m || data.type != 0 || data.major != UINT_MAX || data.minor != UINT_MAX) + json_log(v, flags|JSON_WARNING, 0, "Devices cgroup allow list with arbitrary 'allow' entries not supported, ignoring."); + + /* We ignore the 'deny' entry as for us that's implied */ + continue; + } + + if (!data.r && !data.w && !data.m) { + json_log(v, flags|LOG_WARNING, 0, "Device cgroup allow list entry with no effect found, ignoring."); + continue; + } + + if (data.minor != UINT_MAX && data.major == UINT_MAX) + return json_log(v, flags, SYNTHETIC_ERRNO(EOPNOTSUPP), + "Device cgroup allow list entries with minors but no majors not supported."); + + if (data.major != UINT_MAX && data.type == 0) + return json_log(v, flags, SYNTHETIC_ERRNO(EOPNOTSUPP), + "Device cgroup allow list entries with majors but no device node type not supported."); + + if (data.type == 0) { + if (data.r && data.w && data.m) /* a catchall allow list entry means we are looking at a noop */ + noop = true; + else + return json_log(v, flags, SYNTHETIC_ERRNO(EOPNOTSUPP), + "Device cgroup allow list entries with no type not supported."); + } + + a = reallocarray(list, n_list + 1, sizeof(struct device_data)); + if (!a) + return log_oom(); + + list = a; + list[n_list++] = data; + } + + if (noop) + return 0; + + r = settings_allocate_properties(s); + if (r < 0) + return r; + + r = sd_bus_message_open_container(s->properties, 'r', "sv"); + if (r < 0) + return bus_log_create_error(r); + + r = sd_bus_message_append(s->properties, "s", "DeviceAllow"); + if (r < 0) + return bus_log_create_error(r); + + r = sd_bus_message_open_container(s->properties, 'v', "a(ss)"); + if (r < 0) + return bus_log_create_error(r); + + r = sd_bus_message_open_container(s->properties, 'a', "(ss)"); + if (r < 0) + return bus_log_create_error(r); + + for (i = 0; i < n_list; i++) { + _cleanup_free_ char *pattern = NULL; + char access[4]; + size_t n = 0; + + if (list[i].minor == UINT_MAX) { + const char *t; + + if (list[i].type == S_IFBLK) + t = "block"; + else { + assert(list[i].type == S_IFCHR); + t = "char"; + } + + if (list[i].major == UINT_MAX) { + pattern = strjoin(t, "-*"); + if (!pattern) + return log_oom(); + } else { + if (asprintf(&pattern, "%s-%u", t, list[i].major) < 0) + return log_oom(); + } + + } else { + assert(list[i].major != UINT_MAX); /* If a minor is specified, then a major also needs to be specified */ + + r = device_path_make_major_minor(list[i].type, makedev(list[i].major, list[i].minor), &pattern); + if (r < 0) + return log_oom(); + } + + if (list[i].r) + access[n++] = 'r'; + if (list[i].w) + access[n++] = 'w'; + if (list[i].m) + access[n++] = 'm'; + access[n] = 0; + + assert(n > 0); + + r = sd_bus_message_append(s->properties, "(ss)", pattern, access); + if (r < 0) + return bus_log_create_error(r); + } + + r = sd_bus_message_close_container(s->properties); + if (r < 0) + return bus_log_create_error(r); + + r = sd_bus_message_close_container(s->properties); + if (r < 0) + return bus_log_create_error(r); + + r = sd_bus_message_close_container(s->properties); + if (r < 0) + return bus_log_create_error(r); + + return 0; +} + +static int oci_cgroup_memory_limit(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + uint64_t *m = ASSERT_PTR(userdata); + uint64_t k; + + if (json_variant_is_negative(v)) { + *m = UINT64_MAX; + return 0; + } + + if (!json_variant_is_unsigned(v)) + return json_log(v, flags, SYNTHETIC_ERRNO(EINVAL), + "Memory limit is not an unsigned integer"); + + k = json_variant_unsigned(v); + if (k >= UINT64_MAX) + return json_log(v, flags, SYNTHETIC_ERRNO(ERANGE), + "Memory limit too large: %" PRIu64, k); + + *m = (uint64_t) k; + return 0; +} + +static int oci_cgroup_memory(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + + struct memory_data { + uint64_t limit; + uint64_t reservation; + uint64_t swap; + } data = { + .limit = UINT64_MAX, + .reservation = UINT64_MAX, + .swap = UINT64_MAX, + }; + + static const JsonDispatch table[] = { + { "limit", JSON_VARIANT_NUMBER, oci_cgroup_memory_limit, offsetof(struct memory_data, limit), 0 }, + { "reservation", JSON_VARIANT_NUMBER, oci_cgroup_memory_limit, offsetof(struct memory_data, reservation), 0 }, + { "swap", JSON_VARIANT_NUMBER, oci_cgroup_memory_limit, offsetof(struct memory_data, swap), 0 }, + { "kernel", JSON_VARIANT_NUMBER, oci_unsupported, 0, JSON_PERMISSIVE }, + { "kernelTCP", JSON_VARIANT_NUMBER, oci_unsupported, 0, JSON_PERMISSIVE }, + { "swapiness", JSON_VARIANT_NUMBER, oci_unsupported, 0, JSON_PERMISSIVE }, + { "disableOOMKiller", JSON_VARIANT_NUMBER, oci_unsupported, 0, JSON_PERMISSIVE }, + {} + }; + + Settings *s = userdata; + int r; + + r = json_dispatch(v, table, oci_unexpected, flags, &data); + if (r < 0) + return r; + + if (data.swap != UINT64_MAX) { + if (data.limit == UINT64_MAX) + json_log(v, flags|LOG_WARNING, 0, "swap limit without memory limit is not supported, ignoring."); + else if (data.swap < data.limit) + json_log(v, flags|LOG_WARNING, 0, "swap limit is below memory limit, ignoring."); + else { + r = settings_allocate_properties(s); + if (r < 0) + return r; + + r = sd_bus_message_append(s->properties, "(sv)", "MemorySwapMax", "t", data.swap - data.limit); + if (r < 0) + return bus_log_create_error(r); + } + } + + if (data.limit != UINT64_MAX) { + r = settings_allocate_properties(s); + if (r < 0) + return r; + + r = sd_bus_message_append(s->properties, "(sv)", "MemoryMax", "t", data.limit); + if (r < 0) + return bus_log_create_error(r); + } + + if (data.reservation != UINT64_MAX) { + r = settings_allocate_properties(s); + if (r < 0) + return r; + + r = sd_bus_message_append(s->properties, "(sv)", "MemoryLow", "t", data.reservation); + if (r < 0) + return bus_log_create_error(r); + } + + return 0; +} + +struct cpu_data { + uint64_t shares; + uint64_t quota; + uint64_t period; + CPUSet cpu_set; +}; + +static int oci_cgroup_cpu_shares(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + uint64_t *u = ASSERT_PTR(userdata); + uint64_t k; + + k = json_variant_unsigned(v); + if (k < CGROUP_CPU_SHARES_MIN || k > CGROUP_CPU_SHARES_MAX) + return json_log(v, flags, SYNTHETIC_ERRNO(ERANGE), + "shares value out of range."); + + *u = (uint64_t) k; + return 0; +} + +static int oci_cgroup_cpu_quota(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + uint64_t *u = ASSERT_PTR(userdata); + uint64_t k; + + k = json_variant_unsigned(v); + if (k <= 0 || k >= UINT64_MAX) + return json_log(v, flags, SYNTHETIC_ERRNO(ERANGE), + "period/quota value out of range."); + + *u = (uint64_t) k; + return 0; +} + +static int oci_cgroup_cpu_cpus(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + struct cpu_data *data = ASSERT_PTR(userdata); + CPUSet set; + const char *n; + int r; + + assert_se(n = json_variant_string(v)); + + r = parse_cpu_set(n, &set); + if (r < 0) + return json_log(v, flags, r, "Failed to parse CPU set specification: %s", n); + + cpu_set_reset(&data->cpu_set); + data->cpu_set = set; + + return 0; +} + +static int oci_cgroup_cpu(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + + static const JsonDispatch table[] = { + { "shares", JSON_VARIANT_UNSIGNED, oci_cgroup_cpu_shares, offsetof(struct cpu_data, shares), 0 }, + { "quota", JSON_VARIANT_UNSIGNED, oci_cgroup_cpu_quota, offsetof(struct cpu_data, quota), 0 }, + { "period", JSON_VARIANT_UNSIGNED, oci_cgroup_cpu_quota, offsetof(struct cpu_data, period), 0 }, + { "realtimeRuntime", JSON_VARIANT_UNSIGNED, oci_unsupported, 0, 0 }, + { "realtimePeriod", JSON_VARIANT_UNSIGNED, oci_unsupported, 0, 0 }, + { "cpus", JSON_VARIANT_STRING, oci_cgroup_cpu_cpus, 0, 0 }, + { "mems", JSON_VARIANT_STRING, oci_unsupported, 0, 0 }, + {} + }; + + struct cpu_data data = { + .shares = UINT64_MAX, + .quota = UINT64_MAX, + .period = UINT64_MAX, + }; + + Settings *s = userdata; + int r; + + r = json_dispatch(v, table, oci_unexpected, flags, &data); + if (r < 0) { + cpu_set_reset(&data.cpu_set); + return r; + } + + cpu_set_reset(&s->cpu_set); + s->cpu_set = data.cpu_set; + + if (data.shares != UINT64_MAX) { + r = settings_allocate_properties(s); + if (r < 0) + return r; + + r = sd_bus_message_append(s->properties, "(sv)", "CPUShares", "t", data.shares); + if (r < 0) + return bus_log_create_error(r); + } + + if (data.quota != UINT64_MAX && data.period != UINT64_MAX) { + r = settings_allocate_properties(s); + if (r < 0) + return r; + + r = sd_bus_message_append(s->properties, "(sv)", "CPUQuotaPerSecUSec", "t", (uint64_t) (data.quota * USEC_PER_SEC / data.period)); + if (r < 0) + return bus_log_create_error(r); + + } else if ((data.quota != UINT64_MAX) != (data.period != UINT64_MAX)) + return json_log(v, flags, SYNTHETIC_ERRNO(EINVAL), + "CPU quota and period not used together."); + + return 0; +} + +static int oci_cgroup_block_io_weight(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + Settings *s = ASSERT_PTR(userdata); + uint64_t k; + int r; + + k = json_variant_unsigned(v); + if (k < CGROUP_BLKIO_WEIGHT_MIN || k > CGROUP_BLKIO_WEIGHT_MAX) + return json_log(v, flags, SYNTHETIC_ERRNO(ERANGE), + "Block I/O weight out of range."); + + r = settings_allocate_properties(s); + if (r < 0) + return r; + + r = sd_bus_message_append(s->properties, "(sv)", "BlockIOWeight", "t", (uint64_t) k); + if (r < 0) + return bus_log_create_error(r); + + return 0; +} + +static int oci_cgroup_block_io_weight_device(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + Settings *s = ASSERT_PTR(userdata); + JsonVariant *e; + int r; + + JSON_VARIANT_ARRAY_FOREACH(e, v) { + struct device_data { + unsigned major; + unsigned minor; + uint64_t weight; + } data = { + .major = UINT_MAX, + .minor = UINT_MAX, + .weight = UINT64_MAX, + }; + + static const JsonDispatch table[] = { + { "major", JSON_VARIANT_UNSIGNED, oci_device_major, offsetof(struct device_data, major), JSON_MANDATORY }, + { "minor", JSON_VARIANT_UNSIGNED, oci_device_minor, offsetof(struct device_data, minor), JSON_MANDATORY }, + { "weight", JSON_VARIANT_UNSIGNED, json_dispatch_uint64, offsetof(struct device_data, weight), 0 }, + { "leafWeight", JSON_VARIANT_INTEGER, oci_unsupported, 0, JSON_PERMISSIVE }, + {} + }; + + _cleanup_free_ char *path = NULL; + + r = json_dispatch(e, table, oci_unexpected, flags, &data); + if (r < 0) + return r; + + if (data.weight == UINT64_MAX) + continue; + + if (data.weight < CGROUP_BLKIO_WEIGHT_MIN || data.weight > CGROUP_BLKIO_WEIGHT_MAX) + return json_log(v, flags, SYNTHETIC_ERRNO(ERANGE), + "Block I/O device weight out of range."); + + r = device_path_make_major_minor(S_IFBLK, makedev(data.major, data.minor), &path); + if (r < 0) + return json_log(v, flags, r, "Failed to build device path: %m"); + + r = settings_allocate_properties(s); + if (r < 0) + return r; + + r = sd_bus_message_append(s->properties, "(sv)", "BlockIODeviceWeight", "a(st)", 1, path, (uint64_t) data.weight); + if (r < 0) + return bus_log_create_error(r); + } + + return 0; +} + +static int oci_cgroup_block_io_throttle(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + Settings *s = ASSERT_PTR(userdata); + const char *pname; + JsonVariant *e; + int r; + + pname = streq(name, "throttleReadBpsDevice") ? "IOReadBandwidthMax" : + streq(name, "throttleWriteBpsDevice") ? "IOWriteBandwidthMax" : + streq(name, "throttleReadIOPSDevice") ? "IOReadIOPSMax" : + "IOWriteIOPSMax"; + + JSON_VARIANT_ARRAY_FOREACH(e, v) { + struct device_data { + unsigned major; + unsigned minor; + uint64_t rate; + } data = { + .major = UINT_MAX, + .minor = UINT_MAX, + }; + + static const JsonDispatch table[] = { + { "major", JSON_VARIANT_UNSIGNED, oci_device_major, offsetof(struct device_data, major), JSON_MANDATORY }, + { "minor", JSON_VARIANT_UNSIGNED, oci_device_minor, offsetof(struct device_data, minor), JSON_MANDATORY }, + { "rate", JSON_VARIANT_UNSIGNED, json_dispatch_uint64, offsetof(struct device_data, rate), JSON_MANDATORY }, + {} + }; + + _cleanup_free_ char *path = NULL; + + r = json_dispatch(e, table, oci_unexpected, flags, &data); + if (r < 0) + return r; + + if (data.rate >= UINT64_MAX) + return json_log(v, flags, SYNTHETIC_ERRNO(ERANGE), + "Block I/O device rate out of range."); + + r = device_path_make_major_minor(S_IFBLK, makedev(data.major, data.minor), &path); + if (r < 0) + return json_log(v, flags, r, "Failed to build device path: %m"); + + r = settings_allocate_properties(s); + if (r < 0) + return r; + + r = sd_bus_message_append(s->properties, "(sv)", pname, "a(st)", 1, path, (uint64_t) data.rate); + if (r < 0) + return bus_log_create_error(r); + } + + return 0; +} + +static int oci_cgroup_block_io(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + + static const JsonDispatch table[] = { + { "weight", JSON_VARIANT_UNSIGNED, oci_cgroup_block_io_weight, 0, 0 }, + { "leafWeight", JSON_VARIANT_UNSIGNED, oci_unsupported, 0, JSON_PERMISSIVE }, + { "weightDevice", JSON_VARIANT_ARRAY, oci_cgroup_block_io_weight_device, 0, 0 }, + { "throttleReadBpsDevice", JSON_VARIANT_ARRAY, oci_cgroup_block_io_throttle, 0, 0 }, + { "throttleWriteBpsDevice", JSON_VARIANT_ARRAY, oci_cgroup_block_io_throttle, 0, 0 }, + { "throttleReadIOPSDevice", JSON_VARIANT_ARRAY, oci_cgroup_block_io_throttle, 0, 0 }, + { "throttleWriteIOPSDevice", JSON_VARIANT_ARRAY, oci_cgroup_block_io_throttle, 0, 0 }, + {} + }; + + return json_dispatch(v, table, oci_unexpected, flags, userdata); +} + +static int oci_cgroup_pids(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + + static const JsonDispatch table[] = { + { "limit", JSON_VARIANT_NUMBER, json_dispatch_variant, 0, JSON_MANDATORY }, + {} + }; + + _cleanup_(json_variant_unrefp) JsonVariant *k = NULL; + Settings *s = ASSERT_PTR(userdata); + uint64_t m; + int r; + + r = json_dispatch(v, table, oci_unexpected, flags, &k); + if (r < 0) + return r; + + if (json_variant_is_negative(k)) + m = UINT64_MAX; + else { + if (!json_variant_is_unsigned(k)) + return json_log(k, flags, SYNTHETIC_ERRNO(EINVAL), + "pids limit not unsigned integer, refusing."); + + m = (uint64_t) json_variant_unsigned(k); + + if ((uint64_t) m != json_variant_unsigned(k)) + return json_log(v, flags, SYNTHETIC_ERRNO(EINVAL), + "pids limit out of range, refusing."); + } + + r = settings_allocate_properties(s); + if (r < 0) + return r; + + r = sd_bus_message_append(s->properties, "(sv)", "TasksMax", "t", m); + if (r < 0) + return bus_log_create_error(r); + + return 0; +} + +static int oci_resources(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + + static const JsonDispatch table[] = { + { "devices", JSON_VARIANT_ARRAY, oci_cgroup_devices, 0, 0 }, + { "memory", JSON_VARIANT_OBJECT, oci_cgroup_memory, 0, 0 }, + { "cpu", JSON_VARIANT_OBJECT, oci_cgroup_cpu, 0, 0 }, + { "blockIO", JSON_VARIANT_OBJECT, oci_cgroup_block_io, 0, 0 }, + { "hugepageLimits", JSON_VARIANT_ARRAY, oci_unsupported, 0, 0 }, + { "network", JSON_VARIANT_OBJECT, oci_unsupported, 0, 0 }, + { "pids", JSON_VARIANT_OBJECT, oci_cgroup_pids, 0, 0 }, + { "rdma", JSON_VARIANT_OBJECT, oci_unsupported, 0, 0 }, + {} + }; + + return json_dispatch(v, table, oci_unexpected, flags, userdata); +} + +static bool sysctl_key_valid(const char *s) { + bool dot = true; + + /* Note that we are a bit stricter here than in systemd-sysctl, as that inherited semantics from the old sysctl + * tool, which were really weird (as it swaps / and . in both ways) */ + + if (isempty(s)) + return false; + + for (; *s; s++) { + + if (*s <= ' ' || *s >= 127) + return false; + if (*s == '/') + return false; + if (*s == '.') { + + if (dot) /* Don't allow two dots next to each other (or at the beginning) */ + return false; + + dot = true; + } else + dot = false; + } + + if (dot) /* don't allow a dot at the end */ + return false; + + return true; +} + +static int oci_sysctl(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + Settings *s = ASSERT_PTR(userdata); + JsonVariant *w; + const char *k; + int r; + + JSON_VARIANT_OBJECT_FOREACH(k, w, v) { + const char *m; + + if (!json_variant_is_string(w)) + return json_log(v, flags, SYNTHETIC_ERRNO(EINVAL), + "sysctl parameter is not a string, refusing."); + + assert_se(m = json_variant_string(w)); + + if (!sysctl_key_valid(k)) + return json_log(v, flags, SYNTHETIC_ERRNO(EINVAL), + "sysctl key invalid, refusing: %s", k); + + r = strv_extend_strv(&s->sysctl, STRV_MAKE(k, m), false); + if (r < 0) + return log_oom(); + } + + return 0; +} + +#if HAVE_SECCOMP +static int oci_seccomp_action_from_string(const char *name, uint32_t *ret) { + + static const struct { + const char *name; + uint32_t action; + } table[] = { + { "SCMP_ACT_ALLOW", SCMP_ACT_ALLOW }, + { "SCMP_ACT_ERRNO", SCMP_ACT_ERRNO(EPERM) }, /* the OCI spec doesn't document the error, but it appears EPERM is supposed to be used */ + { "SCMP_ACT_KILL", SCMP_ACT_KILL }, +#ifdef SCMP_ACT_KILL_PROCESS + { "SCMP_ACT_KILL_PROCESS", SCMP_ACT_KILL_PROCESS }, +#endif +#ifdef SCMP_ACT_KILL_THREAD + { "SCMP_ACT_KILL_THREAD", SCMP_ACT_KILL_THREAD }, +#endif +#ifdef SCMP_ACT_LOG + { "SCMP_ACT_LOG", SCMP_ACT_LOG }, +#endif + { "SCMP_ACT_TRAP", SCMP_ACT_TRAP }, + + /* We don't support SCMP_ACT_TRACE because that requires a tracer, and that doesn't really make sense + * here */ + }; + + size_t i; + + for (i = 0; i < ELEMENTSOF(table); i++) + if (streq_ptr(name, table[i].name)) { + *ret = table[i].action; + return 0; + } + + return -EINVAL; +} + +static int oci_seccomp_arch_from_string(const char *name, uint32_t *ret) { + + static const struct { + const char *name; + uint32_t arch; + } table[] = { + { "SCMP_ARCH_AARCH64", SCMP_ARCH_AARCH64 }, + { "SCMP_ARCH_ARM", SCMP_ARCH_ARM }, + { "SCMP_ARCH_MIPS", SCMP_ARCH_MIPS }, + { "SCMP_ARCH_MIPS64", SCMP_ARCH_MIPS64 }, + { "SCMP_ARCH_MIPS64N32", SCMP_ARCH_MIPS64N32 }, + { "SCMP_ARCH_MIPSEL", SCMP_ARCH_MIPSEL }, + { "SCMP_ARCH_MIPSEL64", SCMP_ARCH_MIPSEL64 }, + { "SCMP_ARCH_MIPSEL64N32", SCMP_ARCH_MIPSEL64N32 }, + { "SCMP_ARCH_NATIVE", SCMP_ARCH_NATIVE }, +#ifdef SCMP_ARCH_PARISC + { "SCMP_ARCH_PARISC", SCMP_ARCH_PARISC }, +#endif +#ifdef SCMP_ARCH_PARISC64 + { "SCMP_ARCH_PARISC64", SCMP_ARCH_PARISC64 }, +#endif + { "SCMP_ARCH_PPC", SCMP_ARCH_PPC }, + { "SCMP_ARCH_PPC64", SCMP_ARCH_PPC64 }, + { "SCMP_ARCH_PPC64LE", SCMP_ARCH_PPC64LE }, +#ifdef SCMP_ARCH_RISCV64 + { "SCMP_ARCH_RISCV64", SCMP_ARCH_RISCV64 }, +#endif + { "SCMP_ARCH_S390", SCMP_ARCH_S390 }, + { "SCMP_ARCH_S390X", SCMP_ARCH_S390X }, + { "SCMP_ARCH_X32", SCMP_ARCH_X32 }, + { "SCMP_ARCH_X86", SCMP_ARCH_X86 }, + { "SCMP_ARCH_X86_64", SCMP_ARCH_X86_64 }, + }; + + size_t i; + + for (i = 0; i < ELEMENTSOF(table); i++) + if (streq_ptr(table[i].name, name)) { + *ret = table[i].arch; + return 0; + } + + return -EINVAL; +} + +static int oci_seccomp_compare_from_string(const char *name, enum scmp_compare *ret) { + + static const struct { + const char *name; + enum scmp_compare op; + } table[] = { + { "SCMP_CMP_NE", SCMP_CMP_NE }, + { "SCMP_CMP_LT", SCMP_CMP_LT }, + { "SCMP_CMP_LE", SCMP_CMP_LE }, + { "SCMP_CMP_EQ", SCMP_CMP_EQ }, + { "SCMP_CMP_GE", SCMP_CMP_GE }, + { "SCMP_CMP_GT", SCMP_CMP_GT }, + { "SCMP_CMP_MASKED_EQ", SCMP_CMP_MASKED_EQ }, + }; + + size_t i; + + for (i = 0; i < ELEMENTSOF(table); i++) + if (streq_ptr(table[i].name, name)) { + *ret = table[i].op; + return 0; + } + + return -EINVAL; +} + +static int oci_seccomp_archs(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + scmp_filter_ctx *sc = ASSERT_PTR(userdata); + JsonVariant *e; + int r; + + JSON_VARIANT_ARRAY_FOREACH(e, v) { + uint32_t a; + + if (!json_variant_is_string(e)) + return json_log(e, flags, SYNTHETIC_ERRNO(EINVAL), + "Architecture entry is not a string"); + + r = oci_seccomp_arch_from_string(json_variant_string(e), &a); + if (r < 0) + return json_log(e, flags, r, "Unknown architecture: %s", json_variant_string(e)); + + r = seccomp_arch_add(sc, a); + if (r == -EEXIST) + continue; + if (r < 0) + return json_log(e, flags, r, "Failed to add architecture to seccomp filter: %m"); + } + + return 0; +} + +struct syscall_rule { + char **names; + uint32_t action; + struct scmp_arg_cmp *arguments; + size_t n_arguments; +}; + +static void syscall_rule_free(struct syscall_rule *rule) { + assert(rule); + + strv_free(rule->names); + free(rule->arguments); +}; + +static int oci_seccomp_action(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + uint32_t *action = ASSERT_PTR(userdata); + int r; + + r = oci_seccomp_action_from_string(json_variant_string(v), action); + if (r < 0) + return json_log(v, flags, r, "Unknown system call action '%s': %m", json_variant_string(v)); + + return 0; +} + +static int oci_seccomp_op(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + enum scmp_compare *op = ASSERT_PTR(userdata); + int r; + + r = oci_seccomp_compare_from_string(json_variant_string(v), op); + if (r < 0) + return json_log(v, flags, r, "Unknown seccomp operator '%s': %m", json_variant_string(v)); + + return 0; +} + +static int oci_seccomp_args(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + struct syscall_rule *rule = ASSERT_PTR(userdata); + JsonVariant *e; + int r; + + JSON_VARIANT_ARRAY_FOREACH(e, v) { + static const struct JsonDispatch table[] = { + { "index", JSON_VARIANT_UNSIGNED, json_dispatch_uint32, offsetof(struct scmp_arg_cmp, arg), JSON_MANDATORY }, + { "value", JSON_VARIANT_UNSIGNED, json_dispatch_uint64, offsetof(struct scmp_arg_cmp, datum_a), JSON_MANDATORY }, + { "valueTwo", JSON_VARIANT_UNSIGNED, json_dispatch_uint64, offsetof(struct scmp_arg_cmp, datum_b), 0 }, + { "op", JSON_VARIANT_STRING, oci_seccomp_op, offsetof(struct scmp_arg_cmp, op), JSON_MANDATORY }, + {}, + }; + + struct scmp_arg_cmp *a, *p; + int expected; + + a = reallocarray(rule->arguments, rule->n_arguments + 1, sizeof(struct syscall_rule)); + if (!a) + return log_oom(); + + rule->arguments = a; + p = rule->arguments + rule->n_arguments; + + *p = (struct scmp_arg_cmp) { + .arg = 0, + .datum_a = 0, + .datum_b = 0, + .op = 0, + }; + + r = json_dispatch(e, table, oci_unexpected, flags, p); + if (r < 0) + return r; + + expected = p->op == SCMP_CMP_MASKED_EQ ? 4 : 3; + if (r != expected) + json_log(e, flags|JSON_WARNING, 0, "Wrong number of system call arguments for JSON data data, ignoring."); + + /* Note that we are a bit sloppy here and do not insist that SCMP_CMP_MASKED_EQ gets two datum values, + * and the other only one. That's because buildah for example by default calls things with + * SCMP_CMP_MASKED_EQ but only one argument. We use 0 when the value is not specified. */ + + rule->n_arguments++; + } + + return 0; +} + +static int oci_seccomp_syscalls(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + scmp_filter_ctx *sc = ASSERT_PTR(userdata); + JsonVariant *e; + int r; + + JSON_VARIANT_ARRAY_FOREACH(e, v) { + static const JsonDispatch table[] = { + { "names", JSON_VARIANT_ARRAY, json_dispatch_strv, offsetof(struct syscall_rule, names), JSON_MANDATORY }, + { "action", JSON_VARIANT_STRING, oci_seccomp_action, offsetof(struct syscall_rule, action), JSON_MANDATORY }, + { "args", JSON_VARIANT_ARRAY, oci_seccomp_args, 0, 0 }, + {} + }; + struct syscall_rule rule = { + .action = UINT32_MAX, + }; + + r = json_dispatch(e, table, oci_unexpected, flags, &rule); + if (r < 0) + goto fail_rule; + + if (strv_isempty(rule.names)) { + json_log(e, flags, 0, "System call name list is empty."); + r = -EINVAL; + goto fail_rule; + } + + STRV_FOREACH(i, rule.names) { + int nr; + + nr = seccomp_syscall_resolve_name(*i); + if (nr == __NR_SCMP_ERROR) { + log_debug("Unknown syscall %s, skipping.", *i); + continue; + } + + r = seccomp_rule_add_array(sc, rule.action, nr, rule.n_arguments, rule.arguments); + if (r < 0) + goto fail_rule; + } + + syscall_rule_free(&rule); + continue; + + fail_rule: + syscall_rule_free(&rule); + return r; + } + + return 0; +} +#endif + +static int oci_seccomp(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + +#if HAVE_SECCOMP + static const JsonDispatch table[] = { + { "defaultAction", JSON_VARIANT_STRING, NULL, 0, JSON_MANDATORY }, + { "architectures", JSON_VARIANT_ARRAY, oci_seccomp_archs, 0, 0 }, + { "syscalls", JSON_VARIANT_ARRAY, oci_seccomp_syscalls, 0, 0 }, + {} + }; + + _cleanup_(seccomp_releasep) scmp_filter_ctx sc = NULL; + Settings *s = ASSERT_PTR(userdata); + JsonVariant *def; + uint32_t d; + int r; + + def = json_variant_by_key(v, "defaultAction"); + if (!def) + return json_log(v, flags, SYNTHETIC_ERRNO(EINVAL), "defaultAction element missing."); + + if (!json_variant_is_string(def)) + return json_log(def, flags, SYNTHETIC_ERRNO(EINVAL), "defaultAction is not a string."); + + r = oci_seccomp_action_from_string(json_variant_string(def), &d); + if (r < 0) + return json_log(def, flags, r, "Unknown default action: %s", json_variant_string(def)); + + sc = seccomp_init(d); + if (!sc) + return json_log(v, flags, SYNTHETIC_ERRNO(ENOMEM), "Couldn't allocate seccomp object."); + + r = json_dispatch(v, table, oci_unexpected, flags, sc); + if (r < 0) + return r; + + seccomp_release(s->seccomp); + s->seccomp = TAKE_PTR(sc); + return 0; +#else + return json_log(v, flags, SYNTHETIC_ERRNO(EOPNOTSUPP), "libseccomp support not enabled, can't parse seccomp object."); +#endif +} + +static int oci_rootfs_propagation(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + const char *s; + + s = json_variant_string(v); + + if (streq(s, "shared")) + return 0; + + json_log(v, flags|JSON_DEBUG, 0, "Ignoring rootfsPropagation setting '%s'.", s); + return 0; +} + +static int oci_masked_paths(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + Settings *s = ASSERT_PTR(userdata); + JsonVariant *e; + + JSON_VARIANT_ARRAY_FOREACH(e, v) { + _cleanup_free_ char *destination = NULL; + CustomMount *m; + const char *p; + + if (!json_variant_is_string(e)) + return json_log(v, flags, SYNTHETIC_ERRNO(EINVAL), + "Path is not a string, refusing."); + + assert_se(p = json_variant_string(e)); + + if (!path_is_absolute(p)) + return json_log(v, flags, SYNTHETIC_ERRNO(EINVAL), + "Path is not absolute, refusing: %s", p); + + if (oci_exclude_mount(p)) + continue; + + destination = strdup(p); + if (!destination) + return log_oom(); + + m = custom_mount_add(&s->custom_mounts, &s->n_custom_mounts, CUSTOM_MOUNT_INACCESSIBLE); + if (!m) + return log_oom(); + + m->destination = TAKE_PTR(destination); + + /* The spec doesn't say this, but apparently pre-existing implementations are lenient towards + * non-existing paths to mask. Let's hence be too. */ + m->graceful = true; + } + + return 0; +} + +static int oci_readonly_paths(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + Settings *s = ASSERT_PTR(userdata); + JsonVariant *e; + + JSON_VARIANT_ARRAY_FOREACH(e, v) { + _cleanup_free_ char *source = NULL, *destination = NULL; + CustomMount *m; + const char *p; + + if (!json_variant_is_string(e)) + return json_log(v, flags, SYNTHETIC_ERRNO(EINVAL), + "Path is not a string, refusing."); + + assert_se(p = json_variant_string(e)); + + if (!path_is_absolute(p)) + return json_log(v, flags, SYNTHETIC_ERRNO(EINVAL), + "Path is not absolute, refusing: %s", p); + + if (oci_exclude_mount(p)) + continue; + + source = strjoin("+", p); + if (!source) + return log_oom(); + + destination = strdup(p); + if (!destination) + return log_oom(); + + m = custom_mount_add(&s->custom_mounts, &s->n_custom_mounts, CUSTOM_MOUNT_BIND); + if (!m) + return log_oom(); + + m->source = TAKE_PTR(source); + m->destination = TAKE_PTR(destination); + m->read_only = true; + } + + return 0; +} + +static int oci_linux(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + + static const JsonDispatch table[] = { + { "namespaces", JSON_VARIANT_ARRAY, oci_namespaces, 0, 0 }, + { "uidMappings", JSON_VARIANT_ARRAY, oci_uid_gid_mappings, 0, 0 }, + { "gidMappings", JSON_VARIANT_ARRAY, oci_uid_gid_mappings, 0, 0 }, + { "devices", JSON_VARIANT_ARRAY, oci_devices, 0, 0 }, + { "cgroupsPath", JSON_VARIANT_STRING, oci_cgroups_path, 0, 0 }, + { "resources", JSON_VARIANT_OBJECT, oci_resources, 0, 0 }, + { "intelRdt", JSON_VARIANT_OBJECT, oci_unsupported, 0, JSON_PERMISSIVE }, + { "sysctl", JSON_VARIANT_OBJECT, oci_sysctl, 0, 0 }, + { "seccomp", JSON_VARIANT_OBJECT, oci_seccomp, 0, 0 }, + { "rootfsPropagation", JSON_VARIANT_STRING, oci_rootfs_propagation, 0, 0 }, + { "maskedPaths", JSON_VARIANT_ARRAY, oci_masked_paths, 0, 0 }, + { "readonlyPaths", JSON_VARIANT_ARRAY, oci_readonly_paths, 0, 0 }, + { "mountLabel", JSON_VARIANT_STRING, oci_unsupported, 0, JSON_PERMISSIVE }, + {} + }; + + return json_dispatch(v, table, oci_unexpected, flags, userdata); +} + +static int oci_hook_timeout(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + usec_t *u = userdata; + uint64_t k; + + k = json_variant_unsigned(v); + if (k == 0 || k > (UINT64_MAX-1)/USEC_PER_SEC) + return json_log(v, flags, SYNTHETIC_ERRNO(ERANGE), + "Hook timeout value out of range."); + + *u = k * USEC_PER_SEC; + return 0; +} + +static int oci_hooks_array(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + Settings *s = ASSERT_PTR(userdata); + JsonVariant *e; + int r; + + JSON_VARIANT_ARRAY_FOREACH(e, v) { + + static const JsonDispatch table[] = { + { "path", JSON_VARIANT_STRING, oci_absolute_path, offsetof(OciHook, path), JSON_MANDATORY }, + { "args", JSON_VARIANT_ARRAY, oci_args, offsetof(OciHook, args), 0 }, + { "env", JSON_VARIANT_ARRAY, oci_env, offsetof(OciHook, env), 0 }, + { "timeout", JSON_VARIANT_UNSIGNED, oci_hook_timeout, offsetof(OciHook, timeout), 0 }, + {} + }; + + OciHook *a, **array, *new_item; + size_t *n_array; + + if (streq(name, "prestart")) { + array = &s->oci_hooks_prestart; + n_array = &s->n_oci_hooks_prestart; + } else if (streq(name, "poststart")) { + array = &s->oci_hooks_poststart; + n_array = &s->n_oci_hooks_poststart; + } else { + assert(streq(name, "poststop")); + array = &s->oci_hooks_poststop; + n_array = &s->n_oci_hooks_poststop; + } + + a = reallocarray(*array, *n_array + 1, sizeof(OciHook)); + if (!a) + return log_oom(); + + *array = a; + new_item = a + *n_array; + + *new_item = (OciHook) { + .timeout = USEC_INFINITY, + }; + + r = json_dispatch(e, table, oci_unexpected, flags, new_item); + if (r < 0) { + free(new_item->path); + strv_free(new_item->args); + strv_free(new_item->env); + return r; + } + + (*n_array) ++; + } + + return 0; +} + +static int oci_hooks(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + + static const JsonDispatch table[] = { + { "prestart", JSON_VARIANT_OBJECT, oci_hooks_array, 0, 0 }, + { "poststart", JSON_VARIANT_OBJECT, oci_hooks_array, 0, 0 }, + { "poststop", JSON_VARIANT_OBJECT, oci_hooks_array, 0, 0 }, + {} + }; + + return json_dispatch(v, table, oci_unexpected, flags, userdata); +} + +static int oci_annotations(const char *name, JsonVariant *v, JsonDispatchFlags flags, void *userdata) { + JsonVariant *w; + const char *k; + + JSON_VARIANT_OBJECT_FOREACH(k, w, v) { + + if (isempty(k)) + return json_log(v, flags, SYNTHETIC_ERRNO(EINVAL), + "Annotation with empty key, refusing."); + + if (!json_variant_is_string(w)) + return json_log(w, flags, SYNTHETIC_ERRNO(EINVAL), + "Annotation has non-string value, refusing."); + + json_log(w, flags|JSON_DEBUG, 0, "Ignoring annotation '%s' with value '%s'.", k, json_variant_string(w)); + } + + return 0; +} + +int oci_load(FILE *f, const char *bundle, Settings **ret) { + + static const JsonDispatch table[] = { + { "ociVersion", JSON_VARIANT_STRING, NULL, 0, JSON_MANDATORY }, + { "process", JSON_VARIANT_OBJECT, oci_process, 0, 0 }, + { "root", JSON_VARIANT_OBJECT, oci_root, 0, 0 }, + { "hostname", JSON_VARIANT_STRING, oci_hostname, 0, 0 }, + { "mounts", JSON_VARIANT_ARRAY, oci_mounts, 0, 0 }, + { "linux", JSON_VARIANT_OBJECT, oci_linux, 0, 0 }, + { "hooks", JSON_VARIANT_OBJECT, oci_hooks, 0, 0 }, + { "annotations", JSON_VARIANT_OBJECT, oci_annotations, 0, 0 }, + {} + }; + + _cleanup_(json_variant_unrefp) JsonVariant *oci = NULL; + _cleanup_(settings_freep) Settings *s = NULL; + unsigned line = 0, column = 0; + JsonVariant *v; + const char *path; + int r; + + assert_se(bundle); + + path = strjoina(bundle, "/config.json"); + + r = json_parse_file(f, path, 0, &oci, &line, &column); + if (r < 0) { + if (line != 0 && column != 0) + return log_error_errno(r, "Failed to parse '%s' at %u:%u: %m", path, line, column); + else + return log_error_errno(r, "Failed to parse '%s': %m", path); + } + + v = json_variant_by_key(oci, "ociVersion"); + if (!v) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), + "JSON file '%s' is not an OCI bundle configuration file. Refusing.", + path); + if (!streq_ptr(json_variant_string(v), "1.0.0")) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), + "OCI bundle version not supported: %s", + strna(json_variant_string(v))); + + // { + // _cleanup_free_ char *formatted = NULL; + // assert_se(json_variant_format(oci, JSON_FORMAT_PRETTY|JSON_FORMAT_COLOR, &formatted) >= 0); + // fputs(formatted, stdout); + // } + + s = settings_new(); + if (!s) + return log_oom(); + + s->start_mode = START_PID1; + s->resolv_conf = RESOLV_CONF_OFF; + s->link_journal = LINK_NO; + s->timezone = TIMEZONE_OFF; + + s->bundle = strdup(bundle); + if (!s->bundle) + return log_oom(); + + r = json_dispatch(oci, table, oci_unexpected, 0, s); + if (r < 0) + return r; + + if (s->properties) { + r = sd_bus_message_seal(s->properties, 0, 0); + if (r < 0) + return log_error_errno(r, "Cannot seal properties bus message: %m"); + } + + *ret = TAKE_PTR(s); + return 0; +} diff --git a/src/nspawn/nspawn-oci.h b/src/nspawn/nspawn-oci.h new file mode 100644 index 0000000..ee72c91 --- /dev/null +++ b/src/nspawn/nspawn-oci.h @@ -0,0 +1,6 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ +#pragma once + +#include "nspawn-settings.h" + +int oci_load(FILE *f, const char *path, Settings **ret); diff --git a/src/nspawn/nspawn-patch-uid.c b/src/nspawn/nspawn-patch-uid.c new file mode 100644 index 0000000..75fa931 --- /dev/null +++ b/src/nspawn/nspawn-patch-uid.c @@ -0,0 +1,477 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include <fcntl.h> +#include <sys/statvfs.h> +#include <sys/vfs.h> +#include <unistd.h> + +#include "acl-util.h" +#include "dirent-util.h" +#include "fd-util.h" +#include "fileio.h" +#include "fs-util.h" +#include "missing_magic.h" +#include "nspawn-def.h" +#include "nspawn-patch-uid.h" +#include "stat-util.h" +#include "stdio-util.h" +#include "string-util.h" +#include "strv.h" +#include "user-util.h" + +#if HAVE_ACL + +static int get_acl(int fd, const char *name, acl_type_t type, acl_t *ret) { + acl_t acl; + + assert(fd >= 0); + assert(ret); + + if (name) { + _cleanup_close_ int child_fd = -1; + + child_fd = openat(fd, name, O_PATH|O_CLOEXEC|O_NOFOLLOW); + if (child_fd < 0) + return -errno; + + acl = acl_get_file(FORMAT_PROC_FD_PATH(child_fd), type); + } else if (type == ACL_TYPE_ACCESS) + acl = acl_get_fd(fd); + else + acl = acl_get_file(FORMAT_PROC_FD_PATH(fd), type); + if (!acl) + return -errno; + + *ret = acl; + return 0; +} + +static int set_acl(int fd, const char *name, acl_type_t type, acl_t acl) { + int r; + + assert(fd >= 0); + assert(acl); + + if (name) { + _cleanup_close_ int child_fd = -1; + + child_fd = openat(fd, name, O_PATH|O_CLOEXEC|O_NOFOLLOW); + if (child_fd < 0) + return -errno; + + r = acl_set_file(FORMAT_PROC_FD_PATH(child_fd), type, acl); + } else if (type == ACL_TYPE_ACCESS) + r = acl_set_fd(fd, acl); + else + r = acl_set_file(FORMAT_PROC_FD_PATH(fd), type, acl); + if (r < 0) + return -errno; + + return 0; +} + +static int shift_acl(acl_t acl, uid_t shift, acl_t *ret) { + _cleanup_(acl_freep) acl_t copy = NULL; + acl_entry_t i; + int r; + + assert(acl); + assert(ret); + + r = acl_get_entry(acl, ACL_FIRST_ENTRY, &i); + if (r < 0) + return -errno; + while (r > 0) { + uid_t *old_uid, new_uid; + bool modify = false; + acl_tag_t tag; + + if (acl_get_tag_type(i, &tag) < 0) + return -errno; + + if (IN_SET(tag, ACL_USER, ACL_GROUP)) { + + /* We don't distinguish here between uid_t and gid_t, let's make sure the compiler checks that + * this is actually OK */ + assert_cc(sizeof(uid_t) == sizeof(gid_t)); + + old_uid = acl_get_qualifier(i); + if (!old_uid) + return -errno; + + new_uid = shift | (*old_uid & UINT32_C(0xFFFF)); + if (!uid_is_valid(new_uid)) + return -EINVAL; + + modify = new_uid != *old_uid; + if (modify && !copy) { + int n; + + /* There's no copy of the ACL yet? if so, let's create one, and start the loop from the + * beginning, so that we copy all entries, starting from the first, this time. */ + + n = acl_entries(acl); + if (n < 0) + return -errno; + + copy = acl_init(n); + if (!copy) + return -errno; + + /* Seek back to the beginning */ + r = acl_get_entry(acl, ACL_FIRST_ENTRY, &i); + if (r < 0) + return -errno; + continue; + } + } + + if (copy) { + acl_entry_t new_entry; + + if (acl_create_entry(©, &new_entry) < 0) + return -errno; + + if (acl_copy_entry(new_entry, i) < 0) + return -errno; + + if (modify) + if (acl_set_qualifier(new_entry, &new_uid) < 0) + return -errno; + } + + r = acl_get_entry(acl, ACL_NEXT_ENTRY, &i); + if (r < 0) + return -errno; + } + + *ret = TAKE_PTR(copy); + + return !!*ret; +} + +static int patch_acls(int fd, const char *name, const struct stat *st, uid_t shift) { + _cleanup_(acl_freep) acl_t acl = NULL, shifted = NULL; + bool changed = false; + int r; + + assert(fd >= 0); + assert(st); + + /* ACLs are not supported on symlinks, there's no point in trying */ + if (S_ISLNK(st->st_mode)) + return 0; + + r = get_acl(fd, name, ACL_TYPE_ACCESS, &acl); + if (r == -EOPNOTSUPP) + return 0; + if (r < 0) + return r; + + r = shift_acl(acl, shift, &shifted); + if (r < 0) + return r; + if (r > 0) { + r = set_acl(fd, name, ACL_TYPE_ACCESS, shifted); + if (r < 0) + return r; + + changed = true; + } + + if (S_ISDIR(st->st_mode)) { + acl_free(acl); + + if (shifted) + acl_free(shifted); + + acl = shifted = NULL; + + r = get_acl(fd, name, ACL_TYPE_DEFAULT, &acl); + if (r < 0) + return r; + + r = shift_acl(acl, shift, &shifted); + if (r < 0) + return r; + if (r > 0) { + r = set_acl(fd, name, ACL_TYPE_DEFAULT, shifted); + if (r < 0) + return r; + + changed = true; + } + } + + return changed; +} + +#else + +static int patch_acls(int fd, const char *name, const struct stat *st, uid_t shift) { + return 0; +} + +#endif + +static int patch_fd(int fd, const char *name, const struct stat *st, uid_t shift) { + uid_t new_uid; + gid_t new_gid; + bool changed = false; + int r; + + assert(fd >= 0); + assert(st); + + new_uid = shift | (st->st_uid & UINT32_C(0xFFFF)); + new_gid = (gid_t) shift | (st->st_gid & UINT32_C(0xFFFF)); + + if (!uid_is_valid(new_uid) || !gid_is_valid(new_gid)) + return -EINVAL; + + if (st->st_uid != new_uid || st->st_gid != new_gid) { + if (name) + r = fchownat(fd, name, new_uid, new_gid, AT_SYMLINK_NOFOLLOW); + else + r = fchown(fd, new_uid, new_gid); + if (r < 0) + return -errno; + + /* The Linux kernel alters the mode in some cases of chown(). Let's undo this. */ + if (name) { + if (!S_ISLNK(st->st_mode)) + r = fchmodat(fd, name, st->st_mode, 0); + else /* AT_SYMLINK_NOFOLLOW is not available for fchmodat() */ + r = 0; + } else + r = fchmod(fd, st->st_mode); + if (r < 0) + return -errno; + + changed = true; + } + + r = patch_acls(fd, name, st, shift); + if (r < 0) + return r; + + return r > 0 || changed; +} + +/* + * Check if the filesystem is fully compatible with user namespaces or + * UID/GID patching. Some filesystems in this list can be fully mounted inside + * user namespaces, however their inodes may relate to host resources or only + * valid in the global user namespace, therefore no patching should be applied. + */ +static int is_fs_fully_userns_compatible(const struct statfs *sfs) { + + assert(sfs); + + return F_TYPE_EQUAL(sfs->f_type, BINFMTFS_MAGIC) || + F_TYPE_EQUAL(sfs->f_type, CGROUP_SUPER_MAGIC) || + F_TYPE_EQUAL(sfs->f_type, CGROUP2_SUPER_MAGIC) || + F_TYPE_EQUAL(sfs->f_type, DEBUGFS_MAGIC) || + F_TYPE_EQUAL(sfs->f_type, DEVPTS_SUPER_MAGIC) || + F_TYPE_EQUAL(sfs->f_type, EFIVARFS_MAGIC) || + F_TYPE_EQUAL(sfs->f_type, HUGETLBFS_MAGIC) || + F_TYPE_EQUAL(sfs->f_type, MQUEUE_MAGIC) || + F_TYPE_EQUAL(sfs->f_type, PROC_SUPER_MAGIC) || + F_TYPE_EQUAL(sfs->f_type, PSTOREFS_MAGIC) || + F_TYPE_EQUAL(sfs->f_type, SELINUX_MAGIC) || + F_TYPE_EQUAL(sfs->f_type, SMACK_MAGIC) || + F_TYPE_EQUAL(sfs->f_type, SECURITYFS_MAGIC) || + F_TYPE_EQUAL(sfs->f_type, BPF_FS_MAGIC) || + F_TYPE_EQUAL(sfs->f_type, TRACEFS_MAGIC) || + F_TYPE_EQUAL(sfs->f_type, SYSFS_MAGIC); +} + +static int recurse_fd(int fd, bool donate_fd, const struct stat *st, uid_t shift, bool is_toplevel) { + _cleanup_closedir_ DIR *d = NULL; + bool changed = false; + struct statfs sfs; + int r; + + assert(fd >= 0); + + if (fstatfs(fd, &sfs) < 0) + return -errno; + + /* We generally want to permit crossing of mount boundaries when patching the UIDs/GIDs. However, we probably + * shouldn't do this for /proc and /sys if that is already mounted into place. Hence, let's stop the recursion + * when we hit procfs, sysfs or some other special file systems. */ + + r = is_fs_fully_userns_compatible(&sfs); + if (r < 0) + goto finish; + if (r > 0) { + r = 0; /* don't recurse */ + goto finish; + } + + /* Also, if we hit a read-only file system, then don't bother, skip the whole subtree */ + if ((sfs.f_flags & ST_RDONLY) || + access_fd(fd, W_OK) == -EROFS) + goto read_only; + + if (S_ISDIR(st->st_mode)) { + if (!donate_fd) { + int copy; + + copy = fcntl(fd, F_DUPFD_CLOEXEC, 3); + if (copy < 0) { + r = -errno; + goto finish; + } + + fd = copy; + donate_fd = true; + } + + d = take_fdopendir(&fd); + if (!d) { + r = -errno; + goto finish; + } + + FOREACH_DIRENT_ALL(de, d, r = -errno; goto finish) { + struct stat fst; + + if (dot_or_dot_dot(de->d_name)) + continue; + + if (fstatat(dirfd(d), de->d_name, &fst, AT_SYMLINK_NOFOLLOW) < 0) { + r = -errno; + goto finish; + } + + if (S_ISDIR(fst.st_mode)) { + int subdir_fd; + + subdir_fd = openat(dirfd(d), de->d_name, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC|O_NOFOLLOW|O_NOATIME); + if (subdir_fd < 0) { + r = -errno; + goto finish; + + } + + r = recurse_fd(subdir_fd, true, &fst, shift, false); + if (r < 0) + goto finish; + if (r > 0) + changed = true; + + } else { + r = patch_fd(dirfd(d), de->d_name, &fst, shift); + if (r < 0) + goto finish; + if (r > 0) + changed = true; + } + } + } + + /* After we descended, also patch the directory itself. It's key to do this in this order so that the top-level + * directory is patched as very last object in the tree, so that we can use it as quick indicator whether the + * tree is properly chown()ed already. */ + r = patch_fd(d ? dirfd(d) : fd, NULL, st, shift); + if (r == -EROFS) + goto read_only; + if (r > 0) + changed = true; + + r = changed; + goto finish; + +read_only: + if (!is_toplevel) { + _cleanup_free_ char *name = NULL; + + /* When we hit a ready-only subtree we simply skip it, but log about it. */ + (void) fd_get_path(fd, &name); + log_debug("Skipping read-only file or directory %s.", strna(name)); + r = changed; + } + +finish: + if (donate_fd) + safe_close(fd); + + return r; +} + +static int fd_patch_uid_internal(int fd, bool donate_fd, uid_t shift, uid_t range) { + struct stat st; + int r; + + assert(fd >= 0); + + /* Recursively adjusts the UID/GIDs of all files of a directory tree. This is used to automatically fix up an + * OS tree to the used user namespace UID range. Note that this automatic adjustment only works for UID ranges + * following the concept that the upper 16bit of a UID identify the container, and the lower 16bit are the actual + * UID within the container. */ + + if ((shift & 0xFFFF) != 0) { + /* We only support containers where the shift starts at a 2^16 boundary */ + r = -EOPNOTSUPP; + goto finish; + } + + if (shift == UID_BUSY_BASE) { + r = -EINVAL; + goto finish; + } + + if (range != 0x10000) { + /* We only support containers with 16bit UID ranges for the patching logic */ + r = -EOPNOTSUPP; + goto finish; + } + + if (fstat(fd, &st) < 0) { + r = -errno; + goto finish; + } + + if ((uint32_t) st.st_uid >> 16 != (uint32_t) st.st_gid >> 16) { + /* We only support containers where the uid/gid container ID match */ + r = -EBADE; + goto finish; + } + + /* Try to detect if the range is already right. Of course, this a pretty drastic optimization, as we assume + * that if the top-level dir has the right upper 16bit assigned, then everything below will have too... */ + if (((uint32_t) (st.st_uid ^ shift) >> 16) == 0) + return 0; + + /* Before we start recursively chowning, mark the top-level dir as "busy" by chowning it to the "busy" + * range. Should we be interrupted in the middle of our work, we'll see it owned by this user and will start + * chown()ing it again, unconditionally, as the busy UID is not a valid UID we'd everpick for ourselves. */ + + if ((st.st_uid & UID_BUSY_MASK) != UID_BUSY_BASE) { + if (fchown(fd, + UID_BUSY_BASE | (st.st_uid & ~UID_BUSY_MASK), + (gid_t) UID_BUSY_BASE | (st.st_gid & ~(gid_t) UID_BUSY_MASK)) < 0) { + r = -errno; + goto finish; + } + } + + return recurse_fd(fd, donate_fd, &st, shift, true); + +finish: + if (donate_fd) + safe_close(fd); + + return r; +} + +int path_patch_uid(const char *path, uid_t shift, uid_t range) { + int fd; + + fd = open(path, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC|O_NOFOLLOW|O_NOATIME); + if (fd < 0) + return -errno; + + return fd_patch_uid_internal(fd, true, shift, range); +} diff --git a/src/nspawn/nspawn-patch-uid.h b/src/nspawn/nspawn-patch-uid.h new file mode 100644 index 0000000..5c7349b --- /dev/null +++ b/src/nspawn/nspawn-patch-uid.h @@ -0,0 +1,7 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#pragma once + +#include <sys/types.h> + +int path_patch_uid(const char *path, uid_t shift, uid_t range); diff --git a/src/nspawn/nspawn-register.c b/src/nspawn/nspawn-register.c new file mode 100644 index 0000000..c78bead --- /dev/null +++ b/src/nspawn/nspawn-register.c @@ -0,0 +1,361 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include "sd-bus.h" + +#include "bus-error.h" +#include "bus-locator.h" +#include "bus-unit-util.h" +#include "bus-util.h" +#include "bus-wait-for-jobs.h" +#include "nspawn-register.h" +#include "special.h" +#include "stat-util.h" +#include "strv.h" +#include "util.h" + +static int append_machine_properties( + sd_bus_message *m, + CustomMount *mounts, + unsigned n_mounts, + int kill_signal) { + + unsigned j; + int r; + + assert(m); + + r = sd_bus_message_append(m, "(sv)", "DevicePolicy", "s", "closed"); + if (r < 0) + return bus_log_create_error(r); + + /* If you make changes here, also make sure to update systemd-nspawn@.service, to keep the device policies in + * sync regardless if we are run with or without the --keep-unit switch. */ + r = sd_bus_message_append(m, "(sv)", "DeviceAllow", "a(ss)", 2, + /* Allow the container to + * access and create the API + * device nodes, so that + * PrivateDevices= in the + * container can work + * fine */ + "/dev/net/tun", "rwm", + /* Allow the container + * access to ptys. However, + * do not permit the + * container to ever create + * these device nodes. */ + "char-pts", "rw"); + if (r < 0) + return bus_log_create_error(r); + + for (j = 0; j < n_mounts; j++) { + CustomMount *cm = mounts + j; + + if (cm->type != CUSTOM_MOUNT_BIND) + continue; + + r = is_device_node(cm->source); + if (r == -ENOENT) { + /* The bind source might only appear as the image is put together, hence don't complain */ + log_debug_errno(r, "Bind mount source %s not found, ignoring: %m", cm->source); + continue; + } + if (r < 0) + return log_error_errno(r, "Failed to stat %s: %m", cm->source); + + if (r) { + r = sd_bus_message_append(m, "(sv)", "DeviceAllow", "a(ss)", 1, + cm->source, cm->read_only ? "r" : "rw"); + if (r < 0) + return log_error_errno(r, "Failed to append message arguments: %m"); + } + } + + if (kill_signal != 0) { + r = sd_bus_message_append(m, "(sv)", "KillSignal", "i", kill_signal); + if (r < 0) + return bus_log_create_error(r); + + r = sd_bus_message_append(m, "(sv)", "KillMode", "s", "mixed"); + if (r < 0) + return bus_log_create_error(r); + } + + return 0; +} + +static int append_controller_property(sd_bus *bus, sd_bus_message *m) { + const char *unique; + int r; + + assert(bus); + assert(m); + + r = sd_bus_get_unique_name(bus, &unique); + if (r < 0) + return log_error_errno(r, "Failed to get unique name: %m"); + + r = sd_bus_message_append(m, "(sv)", "Controller", "s", unique); + if (r < 0) + return bus_log_create_error(r); + + return 0; +} + +int register_machine( + sd_bus *bus, + const char *machine_name, + pid_t pid, + const char *directory, + sd_id128_t uuid, + int local_ifindex, + const char *slice, + CustomMount *mounts, + unsigned n_mounts, + int kill_signal, + char **properties, + sd_bus_message *properties_message, + bool keep_unit, + const char *service) { + + _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL; + int r; + + assert(bus); + + if (keep_unit) { + r = bus_call_method( + bus, + bus_machine_mgr, + "RegisterMachineWithNetwork", + &error, + NULL, + "sayssusai", + machine_name, + SD_BUS_MESSAGE_APPEND_ID128(uuid), + service, + "container", + (uint32_t) pid, + strempty(directory), + local_ifindex > 0 ? 1 : 0, local_ifindex); + } else { + _cleanup_(sd_bus_message_unrefp) sd_bus_message *m = NULL; + + r = bus_message_new_method_call(bus, &m, bus_machine_mgr, "CreateMachineWithNetwork"); + if (r < 0) + return bus_log_create_error(r); + + r = sd_bus_message_append( + m, + "sayssusai", + machine_name, + SD_BUS_MESSAGE_APPEND_ID128(uuid), + service, + "container", + (uint32_t) pid, + strempty(directory), + local_ifindex > 0 ? 1 : 0, local_ifindex); + if (r < 0) + return bus_log_create_error(r); + + r = sd_bus_message_open_container(m, 'a', "(sv)"); + if (r < 0) + return bus_log_create_error(r); + + if (!isempty(slice)) { + r = sd_bus_message_append(m, "(sv)", "Slice", "s", slice); + if (r < 0) + return bus_log_create_error(r); + } + + r = append_controller_property(bus, m); + if (r < 0) + return r; + + r = append_machine_properties( + m, + mounts, + n_mounts, + kill_signal); + if (r < 0) + return r; + + if (properties_message) { + r = sd_bus_message_copy(m, properties_message, true); + if (r < 0) + return bus_log_create_error(r); + } + + r = bus_append_unit_property_assignment_many(m, UNIT_SERVICE, properties); + if (r < 0) + return r; + + r = sd_bus_message_close_container(m); + if (r < 0) + return bus_log_create_error(r); + + r = sd_bus_call(bus, m, 0, &error, NULL); + } + + if (r < 0) + return log_error_errno(r, "Failed to register machine: %s", bus_error_message(&error, r)); + + return 0; +} + +int unregister_machine( + sd_bus *bus, + const char *machine_name) { + + _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL; + int r; + + assert(bus); + + r = bus_call_method(bus, bus_machine_mgr, "UnregisterMachine", &error, NULL, "s", machine_name); + if (r < 0) + log_debug("Failed to unregister machine: %s", bus_error_message(&error, r)); + + return 0; +} + +int allocate_scope( + sd_bus *bus, + const char *machine_name, + pid_t pid, + const char *slice, + CustomMount *mounts, + unsigned n_mounts, + int kill_signal, + char **properties, + sd_bus_message *properties_message) { + + _cleanup_(sd_bus_message_unrefp) sd_bus_message *m = NULL, *reply = NULL; + _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL; + _cleanup_(bus_wait_for_jobs_freep) BusWaitForJobs *w = NULL; + _cleanup_free_ char *scope = NULL; + const char *description, *object; + int r; + + assert(bus); + + r = bus_wait_for_jobs_new(bus, &w); + if (r < 0) + return log_error_errno(r, "Could not watch job: %m"); + + r = unit_name_mangle_with_suffix(machine_name, "as machine name", 0, ".scope", &scope); + if (r < 0) + return log_error_errno(r, "Failed to mangle scope name: %m"); + + r = bus_message_new_method_call(bus, &m, bus_systemd_mgr, "StartTransientUnit"); + if (r < 0) + return bus_log_create_error(r); + + r = sd_bus_message_append(m, "ss", scope, "fail"); + if (r < 0) + return bus_log_create_error(r); + + /* Properties */ + r = sd_bus_message_open_container(m, 'a', "(sv)"); + if (r < 0) + return bus_log_create_error(r); + + description = strjoina("Container ", machine_name); + + r = sd_bus_message_append(m, "(sv)(sv)(sv)(sv)(sv)(sv)", + "PIDs", "au", 1, pid, + "Description", "s", description, + "Delegate", "b", 1, + "CollectMode", "s", "inactive-or-failed", + "AddRef", "b", 1, + "Slice", "s", isempty(slice) ? SPECIAL_MACHINE_SLICE : slice); + if (r < 0) + return bus_log_create_error(r); + + r = append_controller_property(bus, m); + if (r < 0) + return r; + + if (properties_message) { + r = sd_bus_message_copy(m, properties_message, true); + if (r < 0) + return bus_log_create_error(r); + } + + r = append_machine_properties( + m, + mounts, + n_mounts, + kill_signal); + if (r < 0) + return r; + + r = bus_append_unit_property_assignment_many(m, UNIT_SCOPE, properties); + if (r < 0) + return r; + + r = sd_bus_message_close_container(m); + if (r < 0) + return bus_log_create_error(r); + + /* No auxiliary units */ + r = sd_bus_message_append( + m, + "a(sa(sv))", + 0); + if (r < 0) + return bus_log_create_error(r); + + r = sd_bus_call(bus, m, 0, &error, &reply); + if (r < 0) + return log_error_errno(r, "Failed to allocate scope: %s", bus_error_message(&error, r)); + + r = sd_bus_message_read(reply, "o", &object); + if (r < 0) + return bus_log_parse_error(r); + + r = bus_wait_for_jobs_one(w, object, false, NULL); + if (r < 0) + return r; + + return 0; +} + +int terminate_scope( + sd_bus *bus, + const char *machine_name) { + + _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL; + _cleanup_free_ char *scope = NULL; + int r; + + r = unit_name_mangle_with_suffix(machine_name, "to terminate", 0, ".scope", &scope); + if (r < 0) + return log_error_errno(r, "Failed to mangle scope name: %m"); + + r = bus_call_method(bus, bus_systemd_mgr, "AbandonScope", &error, NULL, "s", scope); + if (r < 0) { + log_debug_errno(r, "Failed to abandon scope '%s', ignoring: %s", scope, bus_error_message(&error, r)); + sd_bus_error_free(&error); + } + + r = bus_call_method( + bus, + bus_systemd_mgr, + "KillUnit", + &error, + NULL, + "ssi", + scope, + "all", + (int32_t) SIGKILL); + if (r < 0) { + log_debug_errno(r, "Failed to SIGKILL scope '%s', ignoring: %s", scope, bus_error_message(&error, r)); + sd_bus_error_free(&error); + } + + r = bus_call_method(bus, bus_systemd_mgr, "UnrefUnit", &error, NULL, "s", scope); + if (r < 0) + log_debug_errno(r, "Failed to drop reference to scope '%s', ignoring: %s", scope, bus_error_message(&error, r)); + + return 0; +} diff --git a/src/nspawn/nspawn-register.h b/src/nspawn/nspawn-register.h new file mode 100644 index 0000000..59fdd1b --- /dev/null +++ b/src/nspawn/nspawn-register.h @@ -0,0 +1,14 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ +#pragma once + +#include <sys/types.h> + +#include "sd-id128.h" + +#include "nspawn-mount.h" + +int register_machine(sd_bus *bus, const char *machine_name, pid_t pid, const char *directory, sd_id128_t uuid, int local_ifindex, const char *slice, CustomMount *mounts, unsigned n_mounts, int kill_signal, char **properties, sd_bus_message *properties_message, bool keep_unit, const char *service); +int unregister_machine(sd_bus *bus, const char *machine_name); + +int allocate_scope(sd_bus *bus, const char *machine_name, pid_t pid, const char *slice, CustomMount *mounts, unsigned n_mounts, int kill_signal, char **properties, sd_bus_message *properties_message); +int terminate_scope(sd_bus *bus, const char *machine_name); diff --git a/src/nspawn/nspawn-seccomp.c b/src/nspawn/nspawn-seccomp.c new file mode 100644 index 0000000..27044fa --- /dev/null +++ b/src/nspawn/nspawn-seccomp.c @@ -0,0 +1,260 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include <errno.h> +#include <linux/netlink.h> +#include <sys/capability.h> +#include <sys/socket.h> +#include <sys/types.h> + +#if HAVE_SECCOMP +#include <seccomp.h> +#endif + +#include "alloc-util.h" +#include "log.h" +#include "nspawn-seccomp.h" +#if HAVE_SECCOMP +#include "seccomp-util.h" +#endif +#include "string-util.h" +#include "strv.h" + +#if HAVE_SECCOMP + +static int add_syscall_filters( + scmp_filter_ctx ctx, + uint32_t arch, + uint64_t cap_list_retain, + char **syscall_allow_list, + char **syscall_deny_list) { + + static const struct { + uint64_t capability; + const char* name; + } allow_list[] = { + /* Let's use set names where we can */ + { 0, "@aio" }, + { 0, "@basic-io" }, + { 0, "@chown" }, + { 0, "@default" }, + { 0, "@file-system" }, + { 0, "@io-event" }, + { 0, "@ipc" }, + { 0, "@mount" }, + { 0, "@network-io" }, + { 0, "@process" }, + { 0, "@resources" }, + { 0, "@setuid" }, + { 0, "@signal" }, + { 0, "@sync" }, + { 0, "@timer" }, + + /* The following four are sets we optionally enable, in case the caps have been configured for it */ + { CAP_SYS_TIME, "@clock" }, + { CAP_SYS_MODULE, "@module" }, + { CAP_SYS_RAWIO, "@raw-io" }, + { CAP_IPC_LOCK, "@memlock" }, + + /* Plus a good set of additional syscalls which are not part of any of the groups above */ + { 0, "brk" }, + { 0, "capget" }, + { 0, "capset" }, + { 0, "copy_file_range" }, + { 0, "fadvise64" }, + { 0, "fadvise64_64" }, + { 0, "flock" }, + { 0, "get_mempolicy" }, + { 0, "getcpu" }, + { 0, "getpriority" }, + { 0, "getrandom" }, + { 0, "ioctl" }, + { 0, "ioprio_get" }, + { 0, "kcmp" }, + { 0, "madvise" }, + { 0, "mincore" }, + { 0, "mprotect" }, + { 0, "mremap" }, + { 0, "name_to_handle_at" }, + { 0, "oldolduname" }, + { 0, "olduname" }, + { 0, "personality" }, + { 0, "readahead" }, + { 0, "readdir" }, + { 0, "remap_file_pages" }, + { 0, "sched_get_priority_max" }, + { 0, "sched_get_priority_min" }, + { 0, "sched_getaffinity" }, + { 0, "sched_getattr" }, + { 0, "sched_getparam" }, + { 0, "sched_getscheduler" }, + { 0, "sched_rr_get_interval" }, + { 0, "sched_rr_get_interval_time64" }, + { 0, "sched_yield" }, + { 0, "seccomp" }, + { 0, "sendfile" }, + { 0, "sendfile64" }, + { 0, "setdomainname" }, + { 0, "setfsgid" }, + { 0, "setfsgid32" }, + { 0, "setfsuid" }, + { 0, "setfsuid32" }, + { 0, "sethostname" }, + { 0, "setpgid" }, + { 0, "setsid" }, + { 0, "splice" }, + { 0, "sysinfo" }, + { 0, "tee" }, + { 0, "umask" }, + { 0, "uname" }, + { 0, "userfaultfd" }, + { 0, "vmsplice" }, + + /* The following individual syscalls are added depending on specified caps */ + { CAP_SYS_PACCT, "acct" }, + { CAP_SYS_PTRACE, "process_vm_readv" }, + { CAP_SYS_PTRACE, "process_vm_writev" }, + { CAP_SYS_PTRACE, "ptrace" }, + { CAP_SYS_BOOT, "reboot" }, + { CAP_SYSLOG, "syslog" }, + { CAP_SYS_TTY_CONFIG, "vhangup" }, + + /* + * The following syscalls and groups are knowingly excluded: + * + * @cpu-emulation + * @keyring (NB: keyring is not namespaced!) + * @obsolete + * @pkey + * @swap + * + * bpf + * fanotify_init + * fanotify_mark + * kexec_file_load + * kexec_load + * lookup_dcookie + * nfsservctl + * open_by_handle_at + * perf_event_open + * quotactl + */ + }; + + _cleanup_strv_free_ char **added = NULL; + int r; + + for (size_t i = 0; i < ELEMENTSOF(allow_list); i++) { + if (allow_list[i].capability != 0 && (cap_list_retain & (1ULL << allow_list[i].capability)) == 0) + continue; + + r = seccomp_add_syscall_filter_item(ctx, + allow_list[i].name, + SCMP_ACT_ALLOW, + syscall_deny_list, + false, + &added); + if (r < 0) + return log_error_errno(r, "Failed to add syscall filter item %s: %m", allow_list[i].name); + } + + STRV_FOREACH(p, syscall_allow_list) { + r = seccomp_add_syscall_filter_item(ctx, *p, SCMP_ACT_ALLOW, syscall_deny_list, true, &added); + if (r < 0) + log_warning_errno(r, "Failed to add rule for system call %s on %s, ignoring: %m", + *p, seccomp_arch_to_string(arch)); + } + + /* The default action is ENOSYS. Respond with EPERM to all other "known" but not allow-listed + * syscalls. */ + r = seccomp_add_syscall_filter_item(ctx, "@known", SCMP_ACT_ERRNO(EPERM), added, true, NULL); + if (r < 0) + log_warning_errno(r, "Failed to add rule for @known set on %s, ignoring: %m", + seccomp_arch_to_string(arch)); + +#if (SCMP_VER_MAJOR == 2 && SCMP_VER_MINOR >= 5) || SCMP_VER_MAJOR > 2 + /* We have a large filter here, so let's turn on the binary tree mode if possible. */ + r = seccomp_attr_set(ctx, SCMP_FLTATR_CTL_OPTIMIZE, 2); + if (r < 0) + return r; +#endif + + return 0; +} + +int setup_seccomp(uint64_t cap_list_retain, char **syscall_allow_list, char **syscall_deny_list) { + uint32_t arch; + int r; + + if (!is_seccomp_available()) { + log_debug("SECCOMP features not detected in the kernel or disabled at runtime, disabling SECCOMP filtering"); + return 0; + } + + SECCOMP_FOREACH_LOCAL_ARCH(arch) { + _cleanup_(seccomp_releasep) scmp_filter_ctx seccomp = NULL; + + log_debug("Applying allow list on architecture: %s", seccomp_arch_to_string(arch)); + + /* We install ENOSYS as the default action, but it will only apply to syscalls which are not + * in the @known set, see above. */ + r = seccomp_init_for_arch(&seccomp, arch, SCMP_ACT_ERRNO(ENOSYS)); + if (r < 0) + return log_error_errno(r, "Failed to allocate seccomp object: %m"); + + r = add_syscall_filters(seccomp, arch, cap_list_retain, syscall_allow_list, syscall_deny_list); + if (r < 0) + return r; + + r = seccomp_load(seccomp); + if (ERRNO_IS_SECCOMP_FATAL(r)) + return log_error_errno(r, "Failed to install seccomp filter: %m"); + if (r < 0) + log_debug_errno(r, "Failed to install filter set for architecture %s, skipping: %m", seccomp_arch_to_string(arch)); + } + + SECCOMP_FOREACH_LOCAL_ARCH(arch) { + _cleanup_(seccomp_releasep) scmp_filter_ctx seccomp = NULL; + + log_debug("Applying NETLINK_AUDIT mask on architecture: %s", seccomp_arch_to_string(arch)); + + r = seccomp_init_for_arch(&seccomp, arch, SCMP_ACT_ALLOW); + if (r < 0) + return log_error_errno(r, "Failed to allocate seccomp object: %m"); + + /* + Audit is broken in containers, much of the userspace audit hookup will fail if running inside a + container. We don't care and just turn off creation of audit sockets. + + This will make socket(AF_NETLINK, *, NETLINK_AUDIT) fail with EAFNOSUPPORT which audit userspace uses + as indication that audit is disabled in the kernel. + */ + + r = seccomp_rule_add_exact( + seccomp, + SCMP_ACT_ERRNO(EAFNOSUPPORT), + SCMP_SYS(socket), + 2, + SCMP_A0(SCMP_CMP_EQ, AF_NETLINK), + SCMP_A2(SCMP_CMP_EQ, NETLINK_AUDIT)); + if (r < 0) { + log_debug_errno(r, "Failed to add audit seccomp rule, ignoring: %m"); + continue; + } + + r = seccomp_load(seccomp); + if (ERRNO_IS_SECCOMP_FATAL(r)) + return log_error_errno(r, "Failed to install seccomp audit filter: %m"); + if (r < 0) + log_debug_errno(r, "Failed to install filter set for architecture %s, skipping: %m", seccomp_arch_to_string(arch)); + } + + return 0; +} + +#else + +int setup_seccomp(uint64_t cap_list_retain, char **syscall_allow_list, char **syscall_deny_list) { + return 0; +} + +#endif diff --git a/src/nspawn/nspawn-seccomp.h b/src/nspawn/nspawn-seccomp.h new file mode 100644 index 0000000..2690fba --- /dev/null +++ b/src/nspawn/nspawn-seccomp.h @@ -0,0 +1,6 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ +#pragma once + +#include <sys/types.h> + +int setup_seccomp(uint64_t cap_list_retain, char **syscall_allow_list, char **syscall_deny_list); diff --git a/src/nspawn/nspawn-settings.c b/src/nspawn/nspawn-settings.c new file mode 100644 index 0000000..08f22be --- /dev/null +++ b/src/nspawn/nspawn-settings.c @@ -0,0 +1,957 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include "alloc-util.h" +#include "cap-list.h" +#include "conf-parser.h" +#include "cpu-set-util.h" +#include "hostname-util.h" +#include "namespace-util.h" +#include "nspawn-network.h" +#include "nspawn-settings.h" +#include "parse-util.h" +#include "process-util.h" +#include "rlimit-util.h" +#include "socket-util.h" +#include "string-table.h" +#include "string-util.h" +#include "strv.h" +#include "user-util.h" +#include "util.h" + +Settings *settings_new(void) { + Settings *s; + + s = new(Settings, 1); + if (!s) + return NULL; + + *s = (Settings) { + .start_mode = _START_MODE_INVALID, + .ephemeral = -1, + .personality = PERSONALITY_INVALID, + + .resolv_conf = _RESOLV_CONF_MODE_INVALID, + .link_journal = _LINK_JOURNAL_INVALID, + .timezone = _TIMEZONE_MODE_INVALID, + + .userns_mode = _USER_NAMESPACE_MODE_INVALID, + .userns_ownership = _USER_NAMESPACE_OWNERSHIP_INVALID, + .uid_shift = UID_INVALID, + .uid_range = UID_INVALID, + + .no_new_privileges = -1, + + .read_only = -1, + .volatile_mode = _VOLATILE_MODE_INVALID, + + .private_network = -1, + .network_veth = -1, + + .full_capabilities = CAPABILITY_QUINTET_NULL, + + .uid = UID_INVALID, + .gid = GID_INVALID, + + .console_mode = _CONSOLE_MODE_INVALID, + .console_width = UINT_MAX, + .console_height = UINT_MAX, + + .clone_ns_flags = ULONG_MAX, + .use_cgns = -1, + + .notify_ready = -1, + .suppress_sync = -1, + }; + + return s; +} + +int settings_load(FILE *f, const char *path, Settings **ret) { + _cleanup_(settings_freep) Settings *s = NULL; + int r; + + assert(path); + assert(ret); + + s = settings_new(); + if (!s) + return -ENOMEM; + + r = config_parse(NULL, path, f, + "Exec\0" + "Network\0" + "Files\0", + config_item_perf_lookup, nspawn_gperf_lookup, + CONFIG_PARSE_WARN, + s, NULL); + if (r < 0) + return r; + + /* Make sure that if userns_mode is set, userns_chown is set to something appropriate, and vice versa. Either + * both fields shall be initialized or neither. */ + if (s->userns_mode >= 0 && s->userns_ownership < 0) + s->userns_ownership = s->userns_mode == USER_NAMESPACE_PICK ? USER_NAMESPACE_OWNERSHIP_CHOWN : USER_NAMESPACE_OWNERSHIP_OFF; + if (s->userns_ownership >= 0 && s->userns_mode < 0) + s->userns_mode = USER_NAMESPACE_NO; + + *ret = TAKE_PTR(s); + return 0; +} + +static void free_oci_hooks(OciHook *h, size_t n) { + size_t i; + + assert(h || n == 0); + + for (i = 0; i < n; i++) { + free(h[i].path); + strv_free(h[i].args); + strv_free(h[i].env); + } + + free(h); +} + +void device_node_array_free(DeviceNode *node, size_t n) { + size_t i; + + assert(node || n == 0); + + for (i = 0; i < n; i++) + free(node[i].path); + + free(node); +} + +Settings* settings_free(Settings *s) { + if (!s) + return NULL; + + strv_free(s->parameters); + strv_free(s->environment); + free(s->user); + free(s->pivot_root_new); + free(s->pivot_root_old); + free(s->working_directory); + strv_free(s->syscall_allow_list); + strv_free(s->syscall_deny_list); + rlimit_free_all(s->rlimit); + free(s->hostname); + cpu_set_reset(&s->cpu_set); + strv_free(s->bind_user); + + strv_free(s->network_interfaces); + strv_free(s->network_macvlan); + strv_free(s->network_ipvlan); + strv_free(s->network_veth_extra); + free(s->network_bridge); + free(s->network_zone); + expose_port_free_all(s->expose_ports); + + custom_mount_free_all(s->custom_mounts, s->n_custom_mounts); + + free(s->bundle); + free(s->root); + + free_oci_hooks(s->oci_hooks_prestart, s->n_oci_hooks_prestart); + free_oci_hooks(s->oci_hooks_poststart, s->n_oci_hooks_poststart); + free_oci_hooks(s->oci_hooks_poststop, s->n_oci_hooks_poststop); + + free(s->slice); + sd_bus_message_unref(s->properties); + + free(s->supplementary_gids); + device_node_array_free(s->extra_nodes, s->n_extra_nodes); + free(s->network_namespace_path); + + strv_free(s->sysctl); + +#if HAVE_SECCOMP + seccomp_release(s->seccomp); +#endif + + return mfree(s); +} + +bool settings_private_network(Settings *s) { + assert(s); + + /* Determines whether we shall open up our own private network */ + + return + s->private_network > 0 || + s->network_veth > 0 || + s->network_bridge || + s->network_zone || + s->network_interfaces || + s->network_macvlan || + s->network_ipvlan || + s->network_veth_extra; +} + +bool settings_network_veth(Settings *s) { + assert(s); + + return + s->network_veth > 0 || + s->network_bridge || + s->network_zone; +} + +bool settings_network_configured(Settings *s) { + assert(s); + + /* Determines whether any network configuration setting was used. (i.e. in contrast to + * settings_private_network() above this might also indicate if private networking was explicitly + * turned off.) */ + + return + s->private_network >= 0 || + s->network_veth >= 0 || + s->network_bridge || + s->network_zone || + s->network_interfaces || + s->network_macvlan || + s->network_ipvlan || + s->network_veth_extra || + s->network_namespace_path; +} + +int settings_allocate_properties(Settings *s) { + _cleanup_(sd_bus_unrefp) sd_bus *bus = NULL; + int r; + + assert(s); + + if (s->properties) + return 0; + + r = sd_bus_default_system(&bus); + if (r < 0) + return r; + + r = sd_bus_message_new(bus, &s->properties, SD_BUS_MESSAGE_METHOD_CALL); + if (r < 0) + return r; + + return 0; +} + +DEFINE_CONFIG_PARSE_ENUM(config_parse_volatile_mode, volatile_mode, VolatileMode, "Failed to parse volatile mode"); + +int config_parse_expose_port( + const char *unit, + const char *filename, + unsigned line, + const char *section, + unsigned section_line, + const char *lvalue, + int ltype, + const char *rvalue, + void *data, + void *userdata) { + + Settings *s = data; + int r; + + assert(filename); + assert(lvalue); + assert(rvalue); + + r = expose_port_parse(&s->expose_ports, rvalue); + if (r == -EEXIST) + log_syntax(unit, LOG_WARNING, filename, line, r, "Duplicate port specification, ignoring: %s", rvalue); + else if (r < 0) + log_syntax(unit, LOG_WARNING, filename, line, r, "Failed to parse host port %s: %m", rvalue); + + return 0; +} + +int config_parse_capability( + const char *unit, + const char *filename, + unsigned line, + const char *section, + unsigned section_line, + const char *lvalue, + int ltype, + const char *rvalue, + void *data, + void *userdata) { + + uint64_t u = 0, *result = data; + int r; + + assert(filename); + assert(lvalue); + assert(rvalue); + + for (;;) { + _cleanup_free_ char *word = NULL; + + r = extract_first_word(&rvalue, &word, NULL, 0); + if (r == -ENOMEM) + return log_oom(); + if (r < 0) { + log_syntax(unit, LOG_WARNING, filename, line, r, "Failed to extract capability string, ignoring: %s", rvalue); + return 0; + } + if (r == 0) + break; + + if (streq(word, "all")) + u = UINT64_MAX; + else { + r = capability_from_name(word); + if (r < 0) { + log_syntax(unit, LOG_WARNING, filename, line, r, "Failed to parse capability, ignoring: %s", word); + continue; + } + + u |= UINT64_C(1) << r; + } + } + + *result |= u; + return 0; +} + +int config_parse_pivot_root( + const char *unit, + const char *filename, + unsigned line, + const char *section, + unsigned section_line, + const char *lvalue, + int ltype, + const char *rvalue, + void *data, + void *userdata) { + + Settings *settings = data; + int r; + + assert(filename); + assert(lvalue); + assert(rvalue); + + r = pivot_root_parse(&settings->pivot_root_new, &settings->pivot_root_old, rvalue); + if (r < 0) + log_syntax(unit, LOG_WARNING, filename, line, r, "Invalid pivot root mount specification %s: %m", rvalue); + + return 0; +} + +int config_parse_bind( + const char *unit, + const char *filename, + unsigned line, + const char *section, + unsigned section_line, + const char *lvalue, + int ltype, + const char *rvalue, + void *data, + void *userdata) { + + Settings *settings = data; + int r; + + assert(filename); + assert(lvalue); + assert(rvalue); + + r = bind_mount_parse(&settings->custom_mounts, &settings->n_custom_mounts, rvalue, ltype); + if (r < 0) + log_syntax(unit, LOG_WARNING, filename, line, r, "Invalid bind mount specification %s: %m", rvalue); + + return 0; +} + +int config_parse_tmpfs( + const char *unit, + const char *filename, + unsigned line, + const char *section, + unsigned section_line, + const char *lvalue, + int ltype, + const char *rvalue, + void *data, + void *userdata) { + + Settings *settings = data; + int r; + + assert(filename); + assert(lvalue); + assert(rvalue); + + r = tmpfs_mount_parse(&settings->custom_mounts, &settings->n_custom_mounts, rvalue); + if (r < 0) + log_syntax(unit, LOG_WARNING, filename, line, r, "Invalid temporary file system specification %s: %m", rvalue); + + return 0; +} + +int config_parse_inaccessible( + const char *unit, + const char *filename, + unsigned line, + const char *section, + unsigned section_line, + const char *lvalue, + int ltype, + const char *rvalue, + void *data, + void *userdata) { + + Settings *settings = data; + int r; + + assert(filename); + assert(lvalue); + assert(rvalue); + + r = inaccessible_mount_parse(&settings->custom_mounts, &settings->n_custom_mounts, rvalue); + if (r < 0) + log_syntax(unit, LOG_WARNING, filename, line, r, "Invalid inaccessible file system specification %s: %m", rvalue); + + return 0; +} + +int config_parse_overlay( + const char *unit, + const char *filename, + unsigned line, + const char *section, + unsigned section_line, + const char *lvalue, + int ltype, + const char *rvalue, + void *data, + void *userdata) { + + Settings *settings = data; + int r; + + assert(filename); + assert(lvalue); + assert(rvalue); + + r = overlay_mount_parse(&settings->custom_mounts, &settings->n_custom_mounts, rvalue, ltype); + if (r < 0) + log_syntax(unit, LOG_WARNING, filename, line, r, "Invalid overlay file system specification %s, ignoring: %m", rvalue); + + return 0; +} + +int config_parse_veth_extra( + const char *unit, + const char *filename, + unsigned line, + const char *section, + unsigned section_line, + const char *lvalue, + int ltype, + const char *rvalue, + void *data, + void *userdata) { + + Settings *settings = data; + int r; + + assert(filename); + assert(lvalue); + assert(rvalue); + + r = veth_extra_parse(&settings->network_veth_extra, rvalue); + if (r < 0) + log_syntax(unit, LOG_WARNING, filename, line, r, "Invalid extra virtual Ethernet link specification %s: %m", rvalue); + + return 0; +} + +int config_parse_network_zone( + const char *unit, + const char *filename, + unsigned line, + const char *section, + unsigned section_line, + const char *lvalue, + int ltype, + const char *rvalue, + void *data, + void *userdata) { + + Settings *settings = data; + _cleanup_free_ char *j = NULL; + + assert(filename); + assert(lvalue); + assert(rvalue); + + j = strjoin("vz-", rvalue); + if (!ifname_valid(j)) { + log_syntax(unit, LOG_WARNING, filename, line, 0, "Invalid network zone name, ignoring: %s", rvalue); + return 0; + } + + return free_and_replace(settings->network_zone, j); +} + +int config_parse_boot( + const char *unit, + const char *filename, + unsigned line, + const char *section, + unsigned section_line, + const char *lvalue, + int ltype, + const char *rvalue, + void *data, + void *userdata) { + + Settings *settings = data; + int r; + + assert(filename); + assert(lvalue); + assert(rvalue); + + r = parse_boolean(rvalue); + if (r < 0) { + log_syntax(unit, LOG_WARNING, filename, line, r, "Failed to parse Boot= parameter %s, ignoring: %m", rvalue); + return 0; + } + + if (r) { + if (settings->start_mode == START_PID2) + goto conflict; + + settings->start_mode = START_BOOT; + } else { + if (settings->start_mode == START_BOOT) + goto conflict; + + if (settings->start_mode < 0) + settings->start_mode = START_PID1; + } + + return 0; + +conflict: + log_syntax(unit, LOG_WARNING, filename, line, 0, "Conflicting Boot= or ProcessTwo= setting found. Ignoring."); + return 0; +} + +int config_parse_pid2( + const char *unit, + const char *filename, + unsigned line, + const char *section, + unsigned section_line, + const char *lvalue, + int ltype, + const char *rvalue, + void *data, + void *userdata) { + + Settings *settings = data; + int r; + + assert(filename); + assert(lvalue); + assert(rvalue); + + r = parse_boolean(rvalue); + if (r < 0) { + log_syntax(unit, LOG_WARNING, filename, line, r, "Failed to parse ProcessTwo= parameter %s, ignoring: %m", rvalue); + return 0; + } + + if (r) { + if (settings->start_mode == START_BOOT) + goto conflict; + + settings->start_mode = START_PID2; + } else { + if (settings->start_mode == START_PID2) + goto conflict; + + if (settings->start_mode < 0) + settings->start_mode = START_PID1; + } + + return 0; + +conflict: + log_syntax(unit, LOG_WARNING, filename, line, 0, "Conflicting Boot= or ProcessTwo= setting found. Ignoring."); + return 0; +} + +int config_parse_private_users( + const char *unit, + const char *filename, + unsigned line, + const char *section, + unsigned section_line, + const char *lvalue, + int ltype, + const char *rvalue, + void *data, + void *userdata) { + + Settings *settings = data; + int r; + + assert(filename); + assert(lvalue); + assert(rvalue); + + r = parse_boolean(rvalue); + if (r == 0) { + /* no: User namespacing off */ + settings->userns_mode = USER_NAMESPACE_NO; + settings->uid_shift = UID_INVALID; + settings->uid_range = UINT32_C(0x10000); + } else if (r > 0) { + /* yes: User namespacing on, UID range is read from root dir */ + settings->userns_mode = USER_NAMESPACE_FIXED; + settings->uid_shift = UID_INVALID; + settings->uid_range = UINT32_C(0x10000); + } else if (streq(rvalue, "pick")) { + /* pick: User namespacing on, UID range is picked randomly */ + settings->userns_mode = USER_NAMESPACE_PICK; + settings->uid_shift = UID_INVALID; + settings->uid_range = UINT32_C(0x10000); + } else if (streq(rvalue, "identity")) { + /* identity: User namespacing on, UID range is 0:65536 */ + settings->userns_mode = USER_NAMESPACE_FIXED; + settings->uid_shift = 0; + settings->uid_range = UINT32_C(0x10000); + } else { + const char *range, *shift; + uid_t sh, rn; + + /* anything else: User namespacing on, UID range is explicitly configured */ + + range = strchr(rvalue, ':'); + if (range) { + shift = strndupa_safe(rvalue, range - rvalue); + range++; + + r = safe_atou32(range, &rn); + if (r < 0) { + log_syntax(unit, LOG_WARNING, filename, line, r, "UID/GID range invalid, ignoring: %s", range); + return 0; + } + } else { + shift = rvalue; + rn = UINT32_C(0x10000); + } + + r = parse_uid(shift, &sh); + if (r < 0) { + log_syntax(unit, LOG_WARNING, filename, line, r, "UID/GID shift invalid, ignoring: %s", range); + return 0; + } + + if (!userns_shift_range_valid(sh, rn)) { + log_syntax(unit, LOG_WARNING, filename, line, 0, "UID/GID shift and range combination invalid, ignoring: %s", range); + return 0; + } + + settings->userns_mode = USER_NAMESPACE_FIXED; + settings->uid_shift = sh; + settings->uid_range = rn; + } + + return 0; +} + +int config_parse_syscall_filter( + const char *unit, + const char *filename, + unsigned line, + const char *section, + unsigned section_line, + const char *lvalue, + int ltype, + const char *rvalue, + void *data, + void *userdata) { + + Settings *settings = data; + bool negative; + const char *items; + int r; + + assert(filename); + assert(lvalue); + assert(rvalue); + + negative = rvalue[0] == '~'; + items = negative ? rvalue + 1 : rvalue; + + for (;;) { + _cleanup_free_ char *word = NULL; + + r = extract_first_word(&items, &word, NULL, 0); + if (r == 0) + return 0; + if (r == -ENOMEM) + return log_oom(); + if (r < 0) { + log_syntax(unit, LOG_WARNING, filename, line, r, + "Failed to parse SystemCallFilter= parameter %s, ignoring: %m", rvalue); + return 0; + } + + if (negative) + r = strv_extend(&settings->syscall_deny_list, word); + else + r = strv_extend(&settings->syscall_allow_list, word); + if (r < 0) + return log_oom(); + } +} + +int config_parse_oom_score_adjust( + const char *unit, + const char *filename, + unsigned line, + const char *section, + unsigned section_line, + const char *lvalue, + int ltype, + const char *rvalue, + void *data, + void *userdata) { + + Settings *settings = ASSERT_PTR(data); + int oa, r; + + assert(rvalue); + + if (isempty(rvalue)) { + settings->oom_score_adjust_set = false; + return 0; + } + + r = parse_oom_score_adjust(rvalue, &oa); + if (r == -ERANGE) { + log_syntax(unit, LOG_WARNING, filename, line, r, "OOM score adjust value out of range, ignoring: %s", rvalue); + return 0; + } + if (r < 0) { + log_syntax(unit, LOG_WARNING, filename, line, r, "Failed to parse the OOM score adjust value, ignoring: %s", rvalue); + return 0; + } + + settings->oom_score_adjust = oa; + settings->oom_score_adjust_set = true; + + return 0; +} + +int config_parse_cpu_affinity( + const char *unit, + const char *filename, + unsigned line, + const char *section, + unsigned section_line, + const char *lvalue, + int ltype, + const char *rvalue, + void *data, + void *userdata) { + + Settings *settings = ASSERT_PTR(data); + + assert(rvalue); + + return parse_cpu_set_extend(rvalue, &settings->cpu_set, true, unit, filename, line, lvalue); +} + +DEFINE_CONFIG_PARSE_ENUM(config_parse_resolv_conf, resolv_conf_mode, ResolvConfMode, "Failed to parse resolv.conf mode"); + +static const char *const resolv_conf_mode_table[_RESOLV_CONF_MODE_MAX] = { + [RESOLV_CONF_OFF] = "off", + [RESOLV_CONF_COPY_HOST] = "copy-host", + [RESOLV_CONF_COPY_STATIC] = "copy-static", + [RESOLV_CONF_COPY_UPLINK] = "copy-uplink", + [RESOLV_CONF_COPY_STUB] = "copy-stub", + [RESOLV_CONF_REPLACE_HOST] = "replace-host", + [RESOLV_CONF_REPLACE_STATIC] = "replace-static", + [RESOLV_CONF_REPLACE_UPLINK] = "replace-uplink", + [RESOLV_CONF_REPLACE_STUB] = "replace-stub", + [RESOLV_CONF_BIND_HOST] = "bind-host", + [RESOLV_CONF_BIND_STATIC] = "bind-static", + [RESOLV_CONF_BIND_UPLINK] = "bind-uplink", + [RESOLV_CONF_BIND_STUB] = "bind-stub", + [RESOLV_CONF_DELETE] = "delete", + [RESOLV_CONF_AUTO] = "auto", +}; + +DEFINE_STRING_TABLE_LOOKUP_WITH_BOOLEAN(resolv_conf_mode, ResolvConfMode, RESOLV_CONF_AUTO); + +int parse_link_journal(const char *s, LinkJournal *ret_mode, bool *ret_try) { + int r; + + assert(s); + assert(ret_mode); + assert(ret_try); + + if (streq(s, "auto")) { + *ret_mode = LINK_AUTO; + *ret_try = false; + } else if (streq(s, "guest")) { + *ret_mode = LINK_GUEST; + *ret_try = false; + } else if (streq(s, "host")) { + *ret_mode = LINK_HOST; + *ret_try = false; + } else if (streq(s, "try-guest")) { + *ret_mode = LINK_GUEST; + *ret_try = true; + } else if (streq(s, "try-host")) { + *ret_mode = LINK_HOST; + *ret_try = true; + } else { + /* Also support boolean values, to make things less confusing. */ + r = parse_boolean(s); + if (r < 0) + return r; + + /* Let's consider "true" to be equivalent to "auto". */ + *ret_mode = r ? LINK_AUTO : LINK_NO; + *ret_try = false; + } + + return 0; +} + +int config_parse_link_journal( + const char *unit, + const char *filename, + unsigned line, + const char *section, + unsigned section_line, + const char *lvalue, + int ltype, + const char *rvalue, + void *data, + void *userdata) { + + Settings *settings = ASSERT_PTR(data); + int r; + + assert(rvalue); + + r = parse_link_journal(rvalue, &settings->link_journal, &settings->link_journal_try); + if (r < 0) + log_syntax(unit, LOG_WARNING, filename, line, r, "Failed to parse link journal mode, ignoring: %s", rvalue); + + return 0; +} + +DEFINE_CONFIG_PARSE_ENUM(config_parse_timezone, timezone_mode, TimezoneMode, "Failed to parse timezone mode"); + +static const char *const timezone_mode_table[_TIMEZONE_MODE_MAX] = { + [TIMEZONE_OFF] = "off", + [TIMEZONE_COPY] = "copy", + [TIMEZONE_BIND] = "bind", + [TIMEZONE_SYMLINK] = "symlink", + [TIMEZONE_DELETE] = "delete", + [TIMEZONE_AUTO] = "auto", +}; + +DEFINE_STRING_TABLE_LOOKUP_WITH_BOOLEAN(timezone_mode, TimezoneMode, TIMEZONE_AUTO); + +DEFINE_CONFIG_PARSE_ENUM(config_parse_userns_ownership, user_namespace_ownership, UserNamespaceOwnership, "Failed to parse user namespace ownership mode"); + +static const char *const user_namespace_ownership_table[_USER_NAMESPACE_OWNERSHIP_MAX] = { + [USER_NAMESPACE_OWNERSHIP_OFF] = "off", + [USER_NAMESPACE_OWNERSHIP_CHOWN] = "chown", + [USER_NAMESPACE_OWNERSHIP_MAP] = "map", + [USER_NAMESPACE_OWNERSHIP_AUTO] = "auto", +}; + +DEFINE_STRING_TABLE_LOOKUP(user_namespace_ownership, UserNamespaceOwnership); + +int config_parse_userns_chown( + const char *unit, + const char *filename, + unsigned line, + const char *section, + unsigned section_line, + const char *lvalue, + int ltype, + const char *rvalue, + void *data, + void *userdata) { + + UserNamespaceOwnership *ownership = ASSERT_PTR(data); + int r; + + assert(rvalue); + + /* Compatibility support for UserNamespaceChown=, whose job has been taken over by UserNamespaceOwnership= */ + + r = parse_boolean(rvalue); + if (r < 0) { + log_syntax(unit, LOG_WARNING, filename, line, r, "Failed to parse user namespace ownership mode, ignoring: %s", rvalue); + return 0; + } + + *ownership = r ? USER_NAMESPACE_OWNERSHIP_CHOWN : USER_NAMESPACE_OWNERSHIP_OFF; + return 0; +} + +int config_parse_bind_user( + const char *unit, + const char *filename, + unsigned line, + const char *section, + unsigned section_line, + const char *lvalue, + int ltype, + const char *rvalue, + void *data, + void *userdata) { + + char ***bind_user = ASSERT_PTR(data); + int r; + + assert(rvalue); + + if (isempty(rvalue)) { + *bind_user = strv_free(*bind_user); + return 0; + } + + for (const char* p = rvalue;;) { + _cleanup_free_ char *word = NULL; + + r = extract_first_word(&p, &word, NULL, 0); + if (r == -ENOMEM) + return log_oom(); + if (r < 0) { + log_syntax(unit, LOG_WARNING, filename, line, r, "Failed to parse BindUser= list, ignoring: %s", rvalue); + return 0; + } + if (r == 0) + break; + + if (!valid_user_group_name(word, 0)) { + log_syntax(unit, LOG_WARNING, filename, line, 0, "User name '%s' not valid, ignoring.", word); + return 0; + } + + if (strv_consume(bind_user, TAKE_PTR(word)) < 0) + return log_oom(); + } + + return 0; +} diff --git a/src/nspawn/nspawn-settings.h b/src/nspawn/nspawn-settings.h new file mode 100644 index 0000000..004b663 --- /dev/null +++ b/src/nspawn/nspawn-settings.h @@ -0,0 +1,287 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ +#pragma once + +#include <sched.h> +#include <stdio.h> + +#if HAVE_SECCOMP +#include <seccomp.h> +#endif + +#include "sd-bus.h" +#include "sd-id128.h" + +#include "capability-util.h" +#include "conf-parser.h" +#include "cpu-set-util.h" +#include "macro.h" +#include "missing_resource.h" +#include "nspawn-expose-ports.h" +#include "nspawn-mount.h" +#include "time-util.h" + +typedef enum StartMode { + START_PID1, /* Run parameters as command line as process 1 */ + START_PID2, /* Use stub init process as PID 1, run parameters as command line as process 2 */ + START_BOOT, /* Search for init system, pass arguments as parameters */ + _START_MODE_MAX, + _START_MODE_INVALID = -EINVAL, +} StartMode; + +typedef enum UserNamespaceMode { + USER_NAMESPACE_NO, + USER_NAMESPACE_FIXED, + USER_NAMESPACE_PICK, + _USER_NAMESPACE_MODE_MAX, + _USER_NAMESPACE_MODE_INVALID = -EINVAL, +} UserNamespaceMode; + +typedef enum UserNamespaceOwnership { + USER_NAMESPACE_OWNERSHIP_OFF, + USER_NAMESPACE_OWNERSHIP_CHOWN, + USER_NAMESPACE_OWNERSHIP_MAP, + USER_NAMESPACE_OWNERSHIP_AUTO, + _USER_NAMESPACE_OWNERSHIP_MAX, + _USER_NAMESPACE_OWNERSHIP_INVALID = -1, +} UserNamespaceOwnership; + +typedef enum ResolvConfMode { + RESOLV_CONF_OFF, + RESOLV_CONF_COPY_HOST, /* /etc/resolv.conf */ + RESOLV_CONF_COPY_STATIC, /* /usr/lib/systemd/resolv.conf */ + RESOLV_CONF_COPY_UPLINK, /* /run/systemd/resolve/resolv.conf */ + RESOLV_CONF_COPY_STUB, /* /run/systemd/resolve/stub-resolv.conf */ + RESOLV_CONF_REPLACE_HOST, + RESOLV_CONF_REPLACE_STATIC, + RESOLV_CONF_REPLACE_UPLINK, + RESOLV_CONF_REPLACE_STUB, + RESOLV_CONF_BIND_HOST, + RESOLV_CONF_BIND_STATIC, + RESOLV_CONF_BIND_UPLINK, + RESOLV_CONF_BIND_STUB, + RESOLV_CONF_DELETE, + RESOLV_CONF_AUTO, + _RESOLV_CONF_MODE_MAX, + _RESOLV_CONF_MODE_INVALID = -EINVAL, +} ResolvConfMode; + +typedef enum LinkJournal { + LINK_NO, + LINK_AUTO, + LINK_HOST, + LINK_GUEST, + _LINK_JOURNAL_MAX, + _LINK_JOURNAL_INVALID = -EINVAL, +} LinkJournal; + +typedef enum TimezoneMode { + TIMEZONE_OFF, + TIMEZONE_COPY, + TIMEZONE_BIND, + TIMEZONE_SYMLINK, + TIMEZONE_DELETE, + TIMEZONE_AUTO, + _TIMEZONE_MODE_MAX, + _TIMEZONE_MODE_INVALID = -EINVAL, +} TimezoneMode; + +typedef enum ConsoleMode { + CONSOLE_INTERACTIVE, + CONSOLE_READ_ONLY, + CONSOLE_PASSIVE, + CONSOLE_PIPE, + _CONSOLE_MODE_MAX, + _CONSOLE_MODE_INVALID = -EINVAL, +} ConsoleMode; + +typedef enum SettingsMask { + SETTING_START_MODE = UINT64_C(1) << 0, + SETTING_ENVIRONMENT = UINT64_C(1) << 1, + SETTING_USER = UINT64_C(1) << 2, + SETTING_CAPABILITY = UINT64_C(1) << 3, + SETTING_KILL_SIGNAL = UINT64_C(1) << 4, + SETTING_PERSONALITY = UINT64_C(1) << 5, + SETTING_MACHINE_ID = UINT64_C(1) << 6, + SETTING_NETWORK = UINT64_C(1) << 7, + SETTING_EXPOSE_PORTS = UINT64_C(1) << 8, + SETTING_READ_ONLY = UINT64_C(1) << 9, + SETTING_VOLATILE_MODE = UINT64_C(1) << 10, + SETTING_CUSTOM_MOUNTS = UINT64_C(1) << 11, + SETTING_WORKING_DIRECTORY = UINT64_C(1) << 12, + SETTING_USERNS = UINT64_C(1) << 13, + SETTING_NOTIFY_READY = UINT64_C(1) << 14, + SETTING_PIVOT_ROOT = UINT64_C(1) << 15, + SETTING_SYSCALL_FILTER = UINT64_C(1) << 16, + SETTING_HOSTNAME = UINT64_C(1) << 17, + SETTING_NO_NEW_PRIVILEGES = UINT64_C(1) << 18, + SETTING_OOM_SCORE_ADJUST = UINT64_C(1) << 19, + SETTING_CPU_AFFINITY = UINT64_C(1) << 20, + SETTING_RESOLV_CONF = UINT64_C(1) << 21, + SETTING_LINK_JOURNAL = UINT64_C(1) << 22, + SETTING_TIMEZONE = UINT64_C(1) << 23, + SETTING_EPHEMERAL = UINT64_C(1) << 24, + SETTING_SLICE = UINT64_C(1) << 25, + SETTING_DIRECTORY = UINT64_C(1) << 26, + SETTING_USE_CGNS = UINT64_C(1) << 27, + SETTING_CLONE_NS_FLAGS = UINT64_C(1) << 28, + SETTING_CONSOLE_MODE = UINT64_C(1) << 29, + SETTING_CREDENTIALS = UINT64_C(1) << 30, + SETTING_BIND_USER = UINT64_C(1) << 31, + SETTING_SUPPRESS_SYNC = UINT64_C(1) << 32, + SETTING_RLIMIT_FIRST = UINT64_C(1) << 33, /* we define one bit per resource limit here */ + SETTING_RLIMIT_LAST = UINT64_C(1) << (33 + _RLIMIT_MAX - 1), + _SETTINGS_MASK_ALL = (UINT64_C(1) << (33 + _RLIMIT_MAX)) -1, + _SETTING_FORCE_ENUM_WIDTH = UINT64_MAX +} SettingsMask; + +/* We want to use SETTING_RLIMIT_FIRST in shifts, so make sure it is really 64 bits + * when used in expressions. */ +#define SETTING_RLIMIT_FIRST ((uint64_t) SETTING_RLIMIT_FIRST) +#define SETTING_RLIMIT_LAST ((uint64_t) SETTING_RLIMIT_LAST) + +assert_cc(sizeof(SettingsMask) == 8); +assert_cc(sizeof(SETTING_RLIMIT_FIRST) == 8); +assert_cc(sizeof(SETTING_RLIMIT_LAST) == 8); + +typedef struct DeviceNode { + char *path; + unsigned major; + unsigned minor; + mode_t mode; + uid_t uid; + gid_t gid; +} DeviceNode; + +typedef struct OciHook { + char *path; + char **args; + char **env; + usec_t timeout; +} OciHook; + +typedef struct Settings { + /* [Exec] */ + StartMode start_mode; + int ephemeral; + char **parameters; + char **environment; + char *user; + uint64_t capability; + uint64_t drop_capability; + uint64_t ambient_capability; + int kill_signal; + unsigned long personality; + sd_id128_t machine_id; + char *working_directory; + char *pivot_root_new; + char *pivot_root_old; + UserNamespaceMode userns_mode; + uid_t uid_shift, uid_range; + int notify_ready; + char **syscall_allow_list; + char **syscall_deny_list; + struct rlimit *rlimit[_RLIMIT_MAX]; + char *hostname; + int no_new_privileges; + int oom_score_adjust; + bool oom_score_adjust_set; + CPUSet cpu_set; + ResolvConfMode resolv_conf; + LinkJournal link_journal; + bool link_journal_try; + TimezoneMode timezone; + int suppress_sync; + + /* [Files] */ + int read_only; + VolatileMode volatile_mode; + CustomMount *custom_mounts; + size_t n_custom_mounts; + UserNamespaceOwnership userns_ownership; + char **bind_user; + + /* [Network] */ + int private_network; + int network_veth; + char *network_bridge; + char *network_zone; + char **network_interfaces; + char **network_macvlan; + char **network_ipvlan; + char **network_veth_extra; + ExposePort *expose_ports; + + /* Additional fields, that are specific to OCI runtime case */ + char *bundle; + char *root; + OciHook *oci_hooks_prestart, *oci_hooks_poststart, *oci_hooks_poststop; + size_t n_oci_hooks_prestart, n_oci_hooks_poststart, n_oci_hooks_poststop; + char *slice; + sd_bus_message *properties; + CapabilityQuintet full_capabilities; + uid_t uid; + gid_t gid; + gid_t *supplementary_gids; + size_t n_supplementary_gids; + unsigned console_width, console_height; + ConsoleMode console_mode; + DeviceNode *extra_nodes; + size_t n_extra_nodes; + unsigned long clone_ns_flags; + char *network_namespace_path; + int use_cgns; + char **sysctl; +#if HAVE_SECCOMP + scmp_filter_ctx seccomp; +#endif +} Settings; + +Settings *settings_new(void); +int settings_load(FILE *f, const char *path, Settings **ret); +Settings* settings_free(Settings *s); + +bool settings_network_veth(Settings *s); +bool settings_private_network(Settings *s); +bool settings_network_configured(Settings *s); + +int settings_allocate_properties(Settings *s); + +DEFINE_TRIVIAL_CLEANUP_FUNC(Settings*, settings_free); + +const struct ConfigPerfItem* nspawn_gperf_lookup(const char *key, GPERF_LEN_TYPE length); + +CONFIG_PARSER_PROTOTYPE(config_parse_capability); +CONFIG_PARSER_PROTOTYPE(config_parse_expose_port); +CONFIG_PARSER_PROTOTYPE(config_parse_volatile_mode); +CONFIG_PARSER_PROTOTYPE(config_parse_pivot_root); +CONFIG_PARSER_PROTOTYPE(config_parse_bind); +CONFIG_PARSER_PROTOTYPE(config_parse_tmpfs); +CONFIG_PARSER_PROTOTYPE(config_parse_overlay); +CONFIG_PARSER_PROTOTYPE(config_parse_inaccessible); +CONFIG_PARSER_PROTOTYPE(config_parse_veth_extra); +CONFIG_PARSER_PROTOTYPE(config_parse_network_zone); +CONFIG_PARSER_PROTOTYPE(config_parse_boot); +CONFIG_PARSER_PROTOTYPE(config_parse_pid2); +CONFIG_PARSER_PROTOTYPE(config_parse_private_users); +CONFIG_PARSER_PROTOTYPE(config_parse_syscall_filter); +CONFIG_PARSER_PROTOTYPE(config_parse_oom_score_adjust); +CONFIG_PARSER_PROTOTYPE(config_parse_cpu_affinity); +CONFIG_PARSER_PROTOTYPE(config_parse_resolv_conf); +CONFIG_PARSER_PROTOTYPE(config_parse_link_journal); +CONFIG_PARSER_PROTOTYPE(config_parse_timezone); +CONFIG_PARSER_PROTOTYPE(config_parse_userns_chown); +CONFIG_PARSER_PROTOTYPE(config_parse_userns_ownership); +CONFIG_PARSER_PROTOTYPE(config_parse_bind_user); + +const char *resolv_conf_mode_to_string(ResolvConfMode a) _const_; +ResolvConfMode resolv_conf_mode_from_string(const char *s) _pure_; + +const char *timezone_mode_to_string(TimezoneMode a) _const_; +TimezoneMode timezone_mode_from_string(const char *s) _pure_; + +const char *user_namespace_ownership_to_string(UserNamespaceOwnership a) _const_; +UserNamespaceOwnership user_namespace_ownership_from_string(const char *s) _pure_; + +int parse_link_journal(const char *s, LinkJournal *ret_mode, bool *ret_try); + +void device_node_array_free(DeviceNode *node, size_t n); diff --git a/src/nspawn/nspawn-setuid.c b/src/nspawn/nspawn-setuid.c new file mode 100644 index 0000000..34758d8 --- /dev/null +++ b/src/nspawn/nspawn-setuid.c @@ -0,0 +1,245 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include <fcntl.h> +#include <sys/types.h> +#include <unistd.h> + +#include "alloc-util.h" +#include "def.h" +#include "errno.h" +#include "fd-util.h" +#include "fileio.h" +#include "mkdir.h" +#include "nspawn-setuid.h" +#include "process-util.h" +#include "rlimit-util.h" +#include "signal-util.h" +#include "string-util.h" +#include "strv.h" +#include "user-util.h" +#include "util.h" + +static int spawn_getent(const char *database, const char *key, pid_t *rpid) { + int pipe_fds[2], r; + pid_t pid; + + assert(database); + assert(key); + assert(rpid); + + if (pipe2(pipe_fds, O_CLOEXEC) < 0) + return log_error_errno(errno, "Failed to allocate pipe: %m"); + + r = safe_fork("(getent)", FORK_RESET_SIGNALS|FORK_DEATHSIG|FORK_LOG, &pid); + if (r < 0) { + safe_close_pair(pipe_fds); + return r; + } + if (r == 0) { + char *empty_env = NULL; + + pipe_fds[0] = safe_close(pipe_fds[0]); + + if (rearrange_stdio(-1, TAKE_FD(pipe_fds[1]), -1) < 0) + _exit(EXIT_FAILURE); + + (void) close_all_fds(NULL, 0); + + (void) rlimit_nofile_safe(); + + execle("/usr/bin/getent", "getent", database, key, NULL, &empty_env); + execle("/bin/getent", "getent", database, key, NULL, &empty_env); + _exit(EXIT_FAILURE); + } + + pipe_fds[1] = safe_close(pipe_fds[1]); + + *rpid = pid; + + return pipe_fds[0]; +} + +int change_uid_gid_raw( + uid_t uid, + gid_t gid, + const gid_t *supplementary_gids, + size_t n_supplementary_gids, + bool chown_stdio) { + + if (!uid_is_valid(uid)) + uid = 0; + if (!gid_is_valid(gid)) + gid = 0; + + if (chown_stdio) { + (void) fchown(STDIN_FILENO, uid, gid); + (void) fchown(STDOUT_FILENO, uid, gid); + (void) fchown(STDERR_FILENO, uid, gid); + } + + if (setgroups(n_supplementary_gids, supplementary_gids) < 0) + return log_error_errno(errno, "Failed to set auxiliary groups: %m"); + + if (setresgid(gid, gid, gid) < 0) + return log_error_errno(errno, "setresgid() failed: %m"); + + if (setresuid(uid, uid, uid) < 0) + return log_error_errno(errno, "setresuid() failed: %m"); + + return 0; +} + +int change_uid_gid(const char *user, bool chown_stdio, char **ret_home) { + char *x, *u, *g, *h; + _cleanup_free_ gid_t *gids = NULL; + _cleanup_free_ char *home = NULL, *line = NULL; + _cleanup_fclose_ FILE *f = NULL; + _cleanup_close_ int fd = -1; + unsigned n_gids = 0; + uid_t uid; + gid_t gid; + pid_t pid; + int r; + + assert(ret_home); + + if (!user || STR_IN_SET(user, "root", "0")) { + /* Reset everything fully to 0, just in case */ + + r = reset_uid_gid(); + if (r < 0) + return log_error_errno(r, "Failed to become root: %m"); + + *ret_home = NULL; + return 0; + } + + /* First, get user credentials */ + fd = spawn_getent("passwd", user, &pid); + if (fd < 0) + return fd; + + f = take_fdopen(&fd, "r"); + if (!f) + return log_oom(); + + r = read_line(f, LONG_LINE_MAX, &line); + if (r == 0) + return log_error_errno(SYNTHETIC_ERRNO(ESRCH), + "Failed to resolve user %s.", user); + if (r < 0) + return log_error_errno(r, "Failed to read from getent: %m"); + + (void) wait_for_terminate_and_check("getent passwd", pid, WAIT_LOG); + + x = strchr(line, ':'); + if (!x) + return log_error_errno(SYNTHETIC_ERRNO(EIO), + "/etc/passwd entry has invalid user field."); + + u = strchr(x+1, ':'); + if (!u) + return log_error_errno(SYNTHETIC_ERRNO(EIO), + "/etc/passwd entry has invalid password field."); + + u++; + g = strchr(u, ':'); + if (!g) + return log_error_errno(SYNTHETIC_ERRNO(EIO), + "/etc/passwd entry has invalid UID field."); + + *g = 0; + g++; + x = strchr(g, ':'); + if (!x) + return log_error_errno(SYNTHETIC_ERRNO(EIO), + "/etc/passwd entry has invalid GID field."); + + *x = 0; + h = strchr(x+1, ':'); + if (!h) + return log_error_errno(SYNTHETIC_ERRNO(EIO), + "/etc/passwd entry has invalid GECOS field."); + + h++; + x = strchr(h, ':'); + if (!x) + return log_error_errno(SYNTHETIC_ERRNO(EIO), + "/etc/passwd entry has invalid home directory field."); + + *x = 0; + + r = parse_uid(u, &uid); + if (r < 0) + return log_error_errno(SYNTHETIC_ERRNO(EIO), + "Failed to parse UID of user."); + + r = parse_gid(g, &gid); + if (r < 0) + return log_error_errno(SYNTHETIC_ERRNO(EIO), + "Failed to parse GID of user."); + + home = strdup(h); + if (!home) + return log_oom(); + + f = safe_fclose(f); + line = mfree(line); + + /* Second, get group memberships */ + fd = spawn_getent("initgroups", user, &pid); + if (fd < 0) + return fd; + + f = take_fdopen(&fd, "r"); + if (!f) + return log_oom(); + + r = read_line(f, LONG_LINE_MAX, &line); + if (r == 0) + return log_error_errno(SYNTHETIC_ERRNO(ESRCH), + "Failed to resolve user %s.", user); + if (r < 0) + return log_error_errno(r, "Failed to read from getent: %m"); + + (void) wait_for_terminate_and_check("getent initgroups", pid, WAIT_LOG); + + /* Skip over the username and subsequent separator whitespace */ + x = line; + x += strcspn(x, WHITESPACE); + x += strspn(x, WHITESPACE); + + for (const char *p = x;;) { + _cleanup_free_ char *word = NULL; + + r = extract_first_word(&p, &word, NULL, 0); + if (r < 0) + return log_error_errno(r, "Failed to parse group data from getent: %m"); + if (r == 0) + break; + + if (!GREEDY_REALLOC(gids, n_gids+1)) + return log_oom(); + + r = parse_gid(word, &gids[n_gids++]); + if (r < 0) + return log_error_errno(r, "Failed to parse group data from getent: %m"); + } + + r = mkdir_parents(home, 0775); + if (r < 0) + return log_error_errno(r, "Failed to make home root directory: %m"); + + r = mkdir_safe(home, 0755, uid, gid, 0); + if (r < 0 && !IN_SET(r, -EEXIST, -ENOTDIR)) + return log_error_errno(r, "Failed to make home directory: %m"); + + r = change_uid_gid_raw(uid, gid, gids, n_gids, chown_stdio); + if (r < 0) + return r; + + if (ret_home) + *ret_home = TAKE_PTR(home); + + return 0; +} diff --git a/src/nspawn/nspawn-setuid.h b/src/nspawn/nspawn-setuid.h new file mode 100644 index 0000000..1924711 --- /dev/null +++ b/src/nspawn/nspawn-setuid.h @@ -0,0 +1,5 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ +#pragma once + +int change_uid_gid_raw(uid_t uid, gid_t gid, const gid_t *supplementary_gids, size_t n_supplementary_gids, bool chown_stdio); +int change_uid_gid(const char *user, bool chown_stdio, char **ret_home); diff --git a/src/nspawn/nspawn-stub-pid1.c b/src/nspawn/nspawn-stub-pid1.c new file mode 100644 index 0000000..85c4398 --- /dev/null +++ b/src/nspawn/nspawn-stub-pid1.c @@ -0,0 +1,198 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include <sys/ioctl.h> +#include <sys/reboot.h> +#include <sys/wait.h> +#include <sys/prctl.h> +#include <unistd.h> + +#include "def.h" +#include "exit-status.h" +#include "fd-util.h" +#include "log.h" +#include "nspawn-stub-pid1.h" +#include "process-util.h" +#include "signal-util.h" +#include "time-util.h" + +static int reset_environ(const char *new_environment, size_t length) { + unsigned long start, end; + + start = (unsigned long) new_environment; + end = start + length; + + if (prctl(PR_SET_MM, PR_SET_MM_ENV_START, start, 0, 0) < 0) + return -errno; + + if (prctl(PR_SET_MM, PR_SET_MM_ENV_END, end, 0, 0) < 0) + return -errno; + + return 0; +} + +int stub_pid1(sd_id128_t uuid) { + enum { + STATE_RUNNING, + STATE_REBOOT, + STATE_POWEROFF, + } state = STATE_RUNNING; + + sigset_t fullmask, oldmask, waitmask; + usec_t quit_usec = USEC_INFINITY; + pid_t pid; + int r; + + /* The new environment we set up, on the stack. */ + char new_environment[] = + "container=systemd-nspawn\0" + "container_uuid=XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"; + + /* Implements a stub PID 1, that reaps all processes and processes a couple of standard signals. This is useful + * for allowing arbitrary processes run in a container, and still have all zombies reaped. */ + + assert_se(sigfillset(&fullmask) >= 0); + assert_se(sigprocmask(SIG_BLOCK, &fullmask, &oldmask) >= 0); + + pid = fork(); + if (pid < 0) + return log_error_errno(errno, "Failed to fork child pid: %m"); + + if (pid == 0) { + /* Return in the child */ + assert_se(sigprocmask(SIG_SETMASK, &oldmask, NULL) >= 0); + + if (setsid() < 0) + return log_error_errno(errno, "Failed to become session leader in payload process: %m"); + + return 0; + } + + reset_all_signal_handlers(); + + log_close(); + (void) close_all_fds(NULL, 0); + log_open(); + + if (ioctl(STDIN_FILENO, TIOCNOTTY) < 0) { + if (errno != ENOTTY) + log_warning_errno(errno, "Unexpected error from TIOCNOTTY ioctl in init stub process, ignoring: %m"); + } else + log_warning("Expected TIOCNOTTY to fail, but it succeeded in init stub process, ignoring."); + + /* Flush out /proc/self/environ, so that we don't leak the environment from the host into the container. Also, + * set $container= and $container_uuid= so that clients in the container that query it from /proc/1/environ + * find them set. */ + sd_id128_to_string(uuid, new_environment + sizeof(new_environment) - SD_ID128_STRING_MAX); + reset_environ(new_environment, sizeof(new_environment)); + + (void) rename_process("(sd-stubinit)"); + + assert_se(sigemptyset(&waitmask) >= 0); + assert_se(sigset_add_many(&waitmask, + SIGCHLD, /* posix: process died */ + SIGINT, /* sysv: ctrl-alt-del */ + SIGRTMIN+3, /* systemd: halt */ + SIGRTMIN+4, /* systemd: poweroff */ + SIGRTMIN+5, /* systemd: reboot */ + SIGRTMIN+6, /* systemd: kexec */ + SIGRTMIN+13, /* systemd: halt */ + SIGRTMIN+14, /* systemd: poweroff */ + SIGRTMIN+15, /* systemd: reboot */ + SIGRTMIN+16, /* systemd: kexec */ + -1) >= 0); + + /* Note that we ignore SIGTERM (sysv's reexec), SIGHUP (reload), and all other signals here, since we don't + * support reexec/reloading in this stub process. */ + + for (;;) { + siginfo_t si; + usec_t current_usec; + + si.si_pid = 0; + r = waitid(P_ALL, 0, &si, WEXITED|WNOHANG); + if (r < 0) { + r = log_error_errno(errno, "Failed to reap children: %m"); + goto finish; + } + + current_usec = now(CLOCK_MONOTONIC); + + if (si.si_pid == pid || current_usec >= quit_usec) { + + /* The child we started ourselves died or we reached a timeout. */ + + if (state == STATE_REBOOT) { /* dispatch a queued reboot */ + (void) reboot(RB_AUTOBOOT); + r = log_error_errno(errno, "Failed to reboot: %m"); + goto finish; + + } else if (state == STATE_POWEROFF) + (void) reboot(RB_POWER_OFF); /* if this fails, fall back to normal exit. */ + + if (si.si_pid == pid && si.si_code == CLD_EXITED) + r = si.si_status; /* pass on exit code */ + else + r = EXIT_EXCEPTION; /* signal, coredump, timeout, … */ + + goto finish; + } + if (si.si_pid != 0) + /* We reaped something. Retry until there's nothing more to reap. */ + continue; + + if (quit_usec == USEC_INFINITY) + r = sigwaitinfo(&waitmask, &si); + else + r = sigtimedwait(&waitmask, &si, TIMESPEC_STORE(quit_usec - current_usec)); + if (r < 0) { + if (errno == EINTR) /* strace -p attach can result in EINTR, let's handle this nicely. */ + continue; + if (errno == EAGAIN) /* timeout reached */ + continue; + + r = log_error_errno(errno, "Failed to wait for signal: %m"); + goto finish; + } + + if (si.si_signo == SIGCHLD) + continue; /* Let's reap this */ + + if (state != STATE_RUNNING) + continue; + + /* Would love to use a switch() statement here, but SIGRTMIN is actually a function call, not a + * constant… */ + + if (si.si_signo == SIGRTMIN+3 || + si.si_signo == SIGRTMIN+4 || + si.si_signo == SIGRTMIN+13 || + si.si_signo == SIGRTMIN+14) + + state = STATE_POWEROFF; + + else if (si.si_signo == SIGINT || + si.si_signo == SIGRTMIN+5 || + si.si_signo == SIGRTMIN+6 || + si.si_signo == SIGRTMIN+15 || + si.si_signo == SIGRTMIN+16) + + state = STATE_REBOOT; + else + assert_not_reached(); + + r = kill_and_sigcont(pid, SIGTERM); + + /* Let's send a SIGHUP after the SIGTERM, as shells tend to ignore SIGTERM but do react to SIGHUP. We + * do it strictly in this order, so that the SIGTERM is dispatched first, and SIGHUP second for those + * processes which handle both. That's because services tend to bind configuration reload or something + * else to SIGHUP. */ + + if (r != -ESRCH) + (void) kill(pid, SIGHUP); + + quit_usec = now(CLOCK_MONOTONIC) + DEFAULT_TIMEOUT_USEC; + } + +finish: + _exit(r < 0 ? EXIT_FAILURE : r); +} diff --git a/src/nspawn/nspawn-stub-pid1.h b/src/nspawn/nspawn-stub-pid1.h new file mode 100644 index 0000000..e0810fe --- /dev/null +++ b/src/nspawn/nspawn-stub-pid1.h @@ -0,0 +1,6 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ +#pragma once + +#include "sd-id128.h" + +int stub_pid1(sd_id128_t uuid); diff --git a/src/nspawn/nspawn-util.c b/src/nspawn/nspawn-util.c new file mode 100644 index 0000000..830ac39 --- /dev/null +++ b/src/nspawn/nspawn-util.c @@ -0,0 +1,72 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include "alloc-util.h" +#include "glob-util.h" +#include "log.h" +#include "nspawn-util.h" +#include "parse-util.h" +#include "path-util.h" +#include "string-util.h" + +int systemd_installation_has_version(const char *root, const char *minimal_version) { + int r; + + /* Try to guess if systemd installation is later than the specified version. This + * is hacky and likely to yield false negatives, particularly if the installation + * is non-standard. False positives should be relatively rare. + */ + + FOREACH_STRING(pattern, + /* /lib works for systems without usr-merge, and for systems with a sane + * usr-merge, where /lib is a symlink to /usr/lib. /usr/lib is necessary + * for Gentoo which does a merge without making /lib a symlink. + * Also support multiarch paths von Debian/Ubuntu; *-linux-* is a small + * optimization based on the naming scheme of existing multiarch tuples. + */ + "/lib/systemd/libsystemd-shared-*.so", + "/lib64/systemd/libsystemd-shared-*.so", + "/usr/lib/*-linux-*/systemd/libsystemd-shared-*.so", + "/usr/lib/systemd/libsystemd-shared-*.so", + "/usr/lib64/systemd/libsystemd-shared-*.so") { + + _cleanup_strv_free_ char **names = NULL; + _cleanup_free_ char *path = NULL; + char *c; + + path = path_join(root, pattern); + if (!path) + return -ENOMEM; + + r = glob_extend(&names, path, 0); + if (r == -ENOENT) + continue; + if (r < 0) + return r; + + assert_se(c = endswith(path, "*.so")); + *c = '\0'; /* truncate the glob part */ + + STRV_FOREACH(name, names) { + /* This is most likely to run only once, hence let's not optimize anything. */ + char *t, *t2; + + t = startswith(basename(*name), "libsystemd-shared-"); + if (!t) + continue; + + t2 = endswith(t, ".so"); + if (!t2) + continue; + *t2 = '\0'; + + r = strverscmp_improved(t, minimal_version); + log_debug("Found libsystemd shared at \"%s.so\", version %s (%s).", + *name, t, + r >= 0 ? "OK" : "too old"); + if (r >= 0) + return true; + } + } + + return false; +} diff --git a/src/nspawn/nspawn-util.h b/src/nspawn/nspawn-util.h new file mode 100644 index 0000000..e83cd56 --- /dev/null +++ b/src/nspawn/nspawn-util.h @@ -0,0 +1,4 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ +#pragma once + +int systemd_installation_has_version(const char *root, const char *minimal_version); diff --git a/src/nspawn/nspawn.c b/src/nspawn/nspawn.c new file mode 100644 index 0000000..6c9f084 --- /dev/null +++ b/src/nspawn/nspawn.c @@ -0,0 +1,5913 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#if HAVE_BLKID +#endif +#include <errno.h> +#include <getopt.h> +#include <linux/fs.h> +#include <linux/loop.h> +#if HAVE_SELINUX +#include <selinux/selinux.h> +#endif +#include <stdlib.h> +#include <sys/file.h> +#include <sys/ioctl.h> +#include <sys/personality.h> +#include <sys/prctl.h> +#include <sys/types.h> +#include <sys/wait.h> +#include <termios.h> +#include <unistd.h> + +#include "sd-bus.h" +#include "sd-daemon.h" +#include "sd-id128.h" + +#include "alloc-util.h" +#include "barrier.h" +#include "base-filesystem.h" +#include "blkid-util.h" +#include "btrfs-util.h" +#include "bus-error.h" +#include "bus-util.h" +#include "cap-list.h" +#include "capability-util.h" +#include "cgroup-util.h" +#include "chase-symlinks.h" +#include "copy.h" +#include "cpu-set-util.h" +#include "creds-util.h" +#include "dev-setup.h" +#include "discover-image.h" +#include "dissect-image.h" +#include "env-util.h" +#include "escape.h" +#include "fd-util.h" +#include "fdset.h" +#include "fileio.h" +#include "format-util.h" +#include "fs-util.h" +#include "gpt.h" +#include "hexdecoct.h" +#include "hostname-setup.h" +#include "hostname-util.h" +#include "id128-util.h" +#include "io-util.h" +#include "log.h" +#include "loop-util.h" +#include "loopback-setup.h" +#include "macro.h" +#include "main-func.h" +#include "missing_sched.h" +#include "mkdir.h" +#include "mount-util.h" +#include "mountpoint-util.h" +#include "namespace-util.h" +#include "netlink-util.h" +#include "nspawn-bind-user.h" +#include "nspawn-cgroup.h" +#include "nspawn-creds.h" +#include "nspawn-def.h" +#include "nspawn-expose-ports.h" +#include "nspawn-mount.h" +#include "nspawn-network.h" +#include "nspawn-oci.h" +#include "nspawn-patch-uid.h" +#include "nspawn-register.h" +#include "nspawn-seccomp.h" +#include "nspawn-settings.h" +#include "nspawn-setuid.h" +#include "nspawn-stub-pid1.h" +#include "nspawn-util.h" +#include "nspawn.h" +#include "nulstr-util.h" +#include "os-util.h" +#include "pager.h" +#include "parse-argument.h" +#include "parse-util.h" +#include "pretty-print.h" +#include "process-util.h" +#include "ptyfwd.h" +#include "random-util.h" +#include "raw-clone.h" +#include "resolve-util.h" +#include "rlimit-util.h" +#include "rm-rf.h" +#if HAVE_SECCOMP +#include "seccomp-util.h" +#endif +#include "selinux-util.h" +#include "signal-util.h" +#include "socket-util.h" +#include "stat-util.h" +#include "stdio-util.h" +#include "string-table.h" +#include "string-util.h" +#include "strv.h" +#include "sysctl-util.h" +#include "terminal-util.h" +#include "tmpfile-util.h" +#include "umask-util.h" +#include "unit-name.h" +#include "user-util.h" +#include "util.h" + +/* The notify socket inside the container it can use to talk to nspawn using the sd_notify(3) protocol */ +#define NSPAWN_NOTIFY_SOCKET_PATH "/run/host/notify" + +#define EXIT_FORCE_RESTART 133 + +typedef enum ContainerStatus { + CONTAINER_TERMINATED, + CONTAINER_REBOOTED, +} ContainerStatus; + +static char *arg_directory = NULL; +static char *arg_template = NULL; +static char *arg_chdir = NULL; +static char *arg_pivot_root_new = NULL; +static char *arg_pivot_root_old = NULL; +static char *arg_user = NULL; +static uid_t arg_uid = UID_INVALID; +static gid_t arg_gid = GID_INVALID; +static gid_t* arg_supplementary_gids = NULL; +static size_t arg_n_supplementary_gids = 0; +static sd_id128_t arg_uuid = {}; +static char *arg_machine = NULL; /* The name used by the host to refer to this */ +static char *arg_hostname = NULL; /* The name the payload sees by default */ +static const char *arg_selinux_context = NULL; +static const char *arg_selinux_apifs_context = NULL; +static char *arg_slice = NULL; +static bool arg_private_network = false; +static bool arg_read_only = false; +static StartMode arg_start_mode = START_PID1; +static bool arg_ephemeral = false; +static LinkJournal arg_link_journal = LINK_AUTO; +static bool arg_link_journal_try = false; +static uint64_t arg_caps_retain = + (1ULL << CAP_AUDIT_CONTROL) | + (1ULL << CAP_AUDIT_WRITE) | + (1ULL << CAP_CHOWN) | + (1ULL << CAP_DAC_OVERRIDE) | + (1ULL << CAP_DAC_READ_SEARCH) | + (1ULL << CAP_FOWNER) | + (1ULL << CAP_FSETID) | + (1ULL << CAP_IPC_OWNER) | + (1ULL << CAP_KILL) | + (1ULL << CAP_LEASE) | + (1ULL << CAP_LINUX_IMMUTABLE) | + (1ULL << CAP_MKNOD) | + (1ULL << CAP_NET_BIND_SERVICE) | + (1ULL << CAP_NET_BROADCAST) | + (1ULL << CAP_NET_RAW) | + (1ULL << CAP_SETFCAP) | + (1ULL << CAP_SETGID) | + (1ULL << CAP_SETPCAP) | + (1ULL << CAP_SETUID) | + (1ULL << CAP_SYS_ADMIN) | + (1ULL << CAP_SYS_BOOT) | + (1ULL << CAP_SYS_CHROOT) | + (1ULL << CAP_SYS_NICE) | + (1ULL << CAP_SYS_PTRACE) | + (1ULL << CAP_SYS_RESOURCE) | + (1ULL << CAP_SYS_TTY_CONFIG); +static uint64_t arg_caps_ambient = 0; +static CapabilityQuintet arg_full_capabilities = CAPABILITY_QUINTET_NULL; +static CustomMount *arg_custom_mounts = NULL; +static size_t arg_n_custom_mounts = 0; +static char **arg_setenv = NULL; +static bool arg_quiet = false; +static bool arg_register = true; +static bool arg_keep_unit = false; +static char **arg_network_interfaces = NULL; +static char **arg_network_macvlan = NULL; +static char **arg_network_ipvlan = NULL; +static bool arg_network_veth = false; +static char **arg_network_veth_extra = NULL; +static char *arg_network_bridge = NULL; +static char *arg_network_zone = NULL; +static char *arg_network_namespace_path = NULL; +static PagerFlags arg_pager_flags = 0; +static unsigned long arg_personality = PERSONALITY_INVALID; +static char *arg_image = NULL; +static char *arg_oci_bundle = NULL; +static VolatileMode arg_volatile_mode = VOLATILE_NO; +static ExposePort *arg_expose_ports = NULL; +static char **arg_property = NULL; +static sd_bus_message *arg_property_message = NULL; +static UserNamespaceMode arg_userns_mode = USER_NAMESPACE_NO; +static uid_t arg_uid_shift = UID_INVALID, arg_uid_range = 0x10000U; +static UserNamespaceOwnership arg_userns_ownership = _USER_NAMESPACE_OWNERSHIP_INVALID; +static int arg_kill_signal = 0; +static CGroupUnified arg_unified_cgroup_hierarchy = CGROUP_UNIFIED_UNKNOWN; +static SettingsMask arg_settings_mask = 0; +static int arg_settings_trusted = -1; +static char **arg_parameters = NULL; +static const char *arg_container_service_name = "systemd-nspawn"; +static bool arg_notify_ready = false; +static bool arg_use_cgns = true; +static unsigned long arg_clone_ns_flags = CLONE_NEWIPC|CLONE_NEWPID|CLONE_NEWUTS; +static MountSettingsMask arg_mount_settings = MOUNT_APPLY_APIVFS_RO|MOUNT_APPLY_TMPFS_TMP; +static VeritySettings arg_verity_settings = VERITY_SETTINGS_DEFAULT; +static char **arg_syscall_allow_list = NULL; +static char **arg_syscall_deny_list = NULL; +#if HAVE_SECCOMP +static scmp_filter_ctx arg_seccomp = NULL; +#endif +static struct rlimit *arg_rlimit[_RLIMIT_MAX] = {}; +static bool arg_no_new_privileges = false; +static int arg_oom_score_adjust = 0; +static bool arg_oom_score_adjust_set = false; +static CPUSet arg_cpu_set = {}; +static ResolvConfMode arg_resolv_conf = RESOLV_CONF_AUTO; +static TimezoneMode arg_timezone = TIMEZONE_AUTO; +static unsigned arg_console_width = UINT_MAX, arg_console_height = UINT_MAX; +static DeviceNode* arg_extra_nodes = NULL; +static size_t arg_n_extra_nodes = 0; +static char **arg_sysctl = NULL; +static ConsoleMode arg_console_mode = _CONSOLE_MODE_INVALID; +static Credential *arg_credentials = NULL; +static size_t arg_n_credentials = 0; +static char **arg_bind_user = NULL; +static bool arg_suppress_sync = false; +static char *arg_settings_filename = NULL; + +STATIC_DESTRUCTOR_REGISTER(arg_directory, freep); +STATIC_DESTRUCTOR_REGISTER(arg_template, freep); +STATIC_DESTRUCTOR_REGISTER(arg_chdir, freep); +STATIC_DESTRUCTOR_REGISTER(arg_pivot_root_new, freep); +STATIC_DESTRUCTOR_REGISTER(arg_pivot_root_old, freep); +STATIC_DESTRUCTOR_REGISTER(arg_user, freep); +STATIC_DESTRUCTOR_REGISTER(arg_supplementary_gids, freep); +STATIC_DESTRUCTOR_REGISTER(arg_machine, freep); +STATIC_DESTRUCTOR_REGISTER(arg_hostname, freep); +STATIC_DESTRUCTOR_REGISTER(arg_slice, freep); +STATIC_DESTRUCTOR_REGISTER(arg_setenv, strv_freep); +STATIC_DESTRUCTOR_REGISTER(arg_network_interfaces, strv_freep); +STATIC_DESTRUCTOR_REGISTER(arg_network_macvlan, strv_freep); +STATIC_DESTRUCTOR_REGISTER(arg_network_ipvlan, strv_freep); +STATIC_DESTRUCTOR_REGISTER(arg_network_veth_extra, strv_freep); +STATIC_DESTRUCTOR_REGISTER(arg_network_bridge, freep); +STATIC_DESTRUCTOR_REGISTER(arg_network_zone, freep); +STATIC_DESTRUCTOR_REGISTER(arg_network_namespace_path, freep); +STATIC_DESTRUCTOR_REGISTER(arg_image, freep); +STATIC_DESTRUCTOR_REGISTER(arg_oci_bundle, freep); +STATIC_DESTRUCTOR_REGISTER(arg_property, strv_freep); +STATIC_DESTRUCTOR_REGISTER(arg_property_message, sd_bus_message_unrefp); +STATIC_DESTRUCTOR_REGISTER(arg_parameters, strv_freep); +STATIC_DESTRUCTOR_REGISTER(arg_verity_settings, verity_settings_done); +STATIC_DESTRUCTOR_REGISTER(arg_syscall_allow_list, strv_freep); +STATIC_DESTRUCTOR_REGISTER(arg_syscall_deny_list, strv_freep); +#if HAVE_SECCOMP +STATIC_DESTRUCTOR_REGISTER(arg_seccomp, seccomp_releasep); +#endif +STATIC_DESTRUCTOR_REGISTER(arg_cpu_set, cpu_set_reset); +STATIC_DESTRUCTOR_REGISTER(arg_sysctl, strv_freep); +STATIC_DESTRUCTOR_REGISTER(arg_bind_user, strv_freep); +STATIC_DESTRUCTOR_REGISTER(arg_settings_filename, freep); + +static int handle_arg_console(const char *arg) { + if (streq(arg, "help")) { + puts("autopipe\n" + "interactive\n" + "passive\n" + "pipe\n" + "read-only"); + return 0; + } + + if (streq(arg, "interactive")) + arg_console_mode = CONSOLE_INTERACTIVE; + else if (streq(arg, "read-only")) + arg_console_mode = CONSOLE_READ_ONLY; + else if (streq(arg, "passive")) + arg_console_mode = CONSOLE_PASSIVE; + else if (streq(arg, "pipe")) { + if (isatty(STDIN_FILENO) > 0 && isatty(STDOUT_FILENO) > 0) + log_full(arg_quiet ? LOG_DEBUG : LOG_NOTICE, + "Console mode 'pipe' selected, but standard input/output are connected to an interactive TTY. " + "Most likely you want to use 'interactive' console mode for proper interactivity and shell job control. " + "Proceeding anyway."); + + arg_console_mode = CONSOLE_PIPE; + } else if (streq(arg, "autopipe")) { + if (isatty(STDIN_FILENO) > 0 && isatty(STDOUT_FILENO) > 0) + arg_console_mode = CONSOLE_INTERACTIVE; + else + arg_console_mode = CONSOLE_PIPE; + } else + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Unknown console mode: %s", optarg); + + arg_settings_mask |= SETTING_CONSOLE_MODE; + return 1; +} + +static int help(void) { + _cleanup_free_ char *link = NULL; + int r; + + pager_open(arg_pager_flags); + + r = terminal_urlify_man("systemd-nspawn", "1", &link); + if (r < 0) + return log_oom(); + + printf("%1$s [OPTIONS...] [PATH] [ARGUMENTS...]\n\n" + "%5$sSpawn a command or OS in a light-weight container.%6$s\n\n" + " -h --help Show this help\n" + " --version Print version string\n" + " -q --quiet Do not show status information\n" + " --no-pager Do not pipe output into a pager\n" + " --settings=BOOLEAN Load additional settings from .nspawn file\n\n" + "%3$sImage:%4$s\n" + " -D --directory=PATH Root directory for the container\n" + " --template=PATH Initialize root directory from template directory,\n" + " if missing\n" + " -x --ephemeral Run container with snapshot of root directory, and\n" + " remove it after exit\n" + " -i --image=PATH Root file system disk image (or device node) for\n" + " the container\n" + " --oci-bundle=PATH OCI bundle directory\n" + " --read-only Mount the root directory read-only\n" + " --volatile[=MODE] Run the system in volatile mode\n" + " --root-hash=HASH Specify verity root hash for root disk image\n" + " --root-hash-sig=SIG Specify pkcs7 signature of root hash for verity\n" + " as a DER encoded PKCS7, either as a path to a file\n" + " or as an ASCII base64 encoded string prefixed by\n" + " 'base64:'\n" + " --verity-data=PATH Specify hash device for verity\n" + " --pivot-root=PATH[:PATH]\n" + " Pivot root to given directory in the container\n\n" + "%3$sExecution:%4$s\n" + " -a --as-pid2 Maintain a stub init as PID1, invoke binary as PID2\n" + " -b --boot Boot up full system (i.e. invoke init)\n" + " --chdir=PATH Set working directory in the container\n" + " -E --setenv=NAME[=VALUE] Pass an environment variable to PID 1\n" + " -u --user=USER Run the command under specified user or UID\n" + " --kill-signal=SIGNAL Select signal to use for shutting down PID 1\n" + " --notify-ready=BOOLEAN Receive notifications from the child init process\n" + " --suppress-sync=BOOLEAN\n" + " Suppress any form of disk data synchronization\n\n" + "%3$sSystem Identity:%4$s\n" + " -M --machine=NAME Set the machine name for the container\n" + " --hostname=NAME Override the hostname for the container\n" + " --uuid=UUID Set a specific machine UUID for the container\n\n" + "%3$sProperties:%4$s\n" + " -S --slice=SLICE Place the container in the specified slice\n" + " --property=NAME=VALUE Set scope unit property\n" + " --register=BOOLEAN Register container as machine\n" + " --keep-unit Do not register a scope for the machine, reuse\n" + " the service unit nspawn is running in\n\n" + "%3$sUser Namespacing:%4$s\n" + " --private-users=no Run without user namespacing\n" + " --private-users=yes|pick|identity\n" + " Run within user namespace, autoselect UID/GID range\n" + " --private-users=UIDBASE[:NUIDS]\n" + " Similar, but with user configured UID/GID range\n" + " --private-users-ownership=MODE\n" + " Adjust ('chown') or map ('map') OS tree ownership\n" + " to private UID/GID range\n" + " -U Equivalent to --private-users=pick and\n" + " --private-users-ownership=auto\n\n" + "%3$sNetworking:%4$s\n" + " --private-network Disable network in container\n" + " --network-interface=INTERFACE\n" + " Assign an existing network interface to the\n" + " container\n" + " --network-macvlan=INTERFACE\n" + " Create a macvlan network interface based on an\n" + " existing network interface to the container\n" + " --network-ipvlan=INTERFACE\n" + " Create an ipvlan network interface based on an\n" + " existing network interface to the container\n" + " -n --network-veth Add a virtual Ethernet connection between host\n" + " and container\n" + " --network-veth-extra=HOSTIF[:CONTAINERIF]\n" + " Add an additional virtual Ethernet link between\n" + " host and container\n" + " --network-bridge=INTERFACE\n" + " Add a virtual Ethernet connection to the container\n" + " and attach it to an existing bridge on the host\n" + " --network-zone=NAME Similar, but attach the new interface to an\n" + " an automatically managed bridge interface\n" + " --network-namespace-path=PATH\n" + " Set network namespace to the one represented by\n" + " the specified kernel namespace file node\n" + " -p --port=[PROTOCOL:]HOSTPORT[:CONTAINERPORT]\n" + " Expose a container IP port on the host\n\n" + "%3$sSecurity:%4$s\n" + " --capability=CAP In addition to the default, retain specified\n" + " capability\n" + " --drop-capability=CAP Drop the specified capability from the default set\n" + " --ambient-capability=CAP\n" + " Sets the specified capability for the started\n" + " process. Not useful if booting a machine.\n" + " --no-new-privileges Set PR_SET_NO_NEW_PRIVS flag for container payload\n" + " --system-call-filter=LIST|~LIST\n" + " Permit/prohibit specific system calls\n" + " -Z --selinux-context=SECLABEL\n" + " Set the SELinux security context to be used by\n" + " processes in the container\n" + " -L --selinux-apifs-context=SECLABEL\n" + " Set the SELinux security context to be used by\n" + " API/tmpfs file systems in the container\n\n" + "%3$sResources:%4$s\n" + " --rlimit=NAME=LIMIT Set a resource limit for the payload\n" + " --oom-score-adjust=VALUE\n" + " Adjust the OOM score value for the payload\n" + " --cpu-affinity=CPUS Adjust the CPU affinity of the container\n" + " --personality=ARCH Pick personality for this container\n\n" + "%3$sIntegration:%4$s\n" + " --resolv-conf=MODE Select mode of /etc/resolv.conf initialization\n" + " --timezone=MODE Select mode of /etc/localtime initialization\n" + " --link-journal=MODE Link up guest journal, one of no, auto, guest, \n" + " host, try-guest, try-host\n" + " -j Equivalent to --link-journal=try-guest\n\n" + "%3$sMounts:%4$s\n" + " --bind=PATH[:PATH[:OPTIONS]]\n" + " Bind mount a file or directory from the host into\n" + " the container\n" + " --bind-ro=PATH[:PATH[:OPTIONS]\n" + " Similar, but creates a read-only bind mount\n" + " --inaccessible=PATH Over-mount file node with inaccessible node to mask\n" + " it\n" + " --tmpfs=PATH:[OPTIONS] Mount an empty tmpfs to the specified directory\n" + " --overlay=PATH[:PATH...]:PATH\n" + " Create an overlay mount from the host to \n" + " the container\n" + " --overlay-ro=PATH[:PATH...]:PATH\n" + " Similar, but creates a read-only overlay mount\n" + " --bind-user=NAME Bind user from host to container\n\n" + "%3$sInput/Output:%4$s\n" + " --console=MODE Select how stdin/stdout/stderr and /dev/console are\n" + " set up for the container.\n" + " -P --pipe Equivalent to --console=pipe\n\n" + "%3$sCredentials:%4$s\n" + " --set-credential=ID:VALUE\n" + " Pass a credential with literal value to container.\n" + " --load-credential=ID:PATH\n" + " Load credential to pass to container from file or\n" + " AF_UNIX stream socket.\n" + "\nSee the %2$s for details.\n", + program_invocation_short_name, + link, + ansi_underline(), + ansi_normal(), + ansi_highlight(), + ansi_normal()); + + return 0; +} + +static int custom_mount_check_all(void) { + size_t i; + + for (i = 0; i < arg_n_custom_mounts; i++) { + CustomMount *m = &arg_custom_mounts[i]; + + if (path_equal(m->destination, "/") && arg_userns_mode != USER_NAMESPACE_NO) { + if (arg_userns_ownership != USER_NAMESPACE_OWNERSHIP_OFF) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), + "--private-users-ownership=own may not be combined with custom root mounts."); + if (arg_uid_shift == UID_INVALID) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), + "--private-users with automatic UID shift may not be combined with custom root mounts."); + } + } + + return 0; +} + +static int detect_unified_cgroup_hierarchy_from_environment(void) { + const char *e, *var = "SYSTEMD_NSPAWN_UNIFIED_HIERARCHY"; + int r; + + /* Allow the user to control whether the unified hierarchy is used */ + + e = getenv(var); + if (!e) { + /* $UNIFIED_CGROUP_HIERARCHY has been renamed to $SYSTEMD_NSPAWN_UNIFIED_HIERARCHY. */ + var = "UNIFIED_CGROUP_HIERARCHY"; + e = getenv(var); + } + + if (!isempty(e)) { + r = parse_boolean(e); + if (r < 0) + return log_error_errno(r, "Failed to parse $%s: %m", var); + if (r > 0) + arg_unified_cgroup_hierarchy = CGROUP_UNIFIED_ALL; + else + arg_unified_cgroup_hierarchy = CGROUP_UNIFIED_NONE; + } + + return 0; +} + +static int detect_unified_cgroup_hierarchy_from_image(const char *directory) { + int r; + + /* Let's inherit the mode to use from the host system, but let's take into consideration what systemd + * in the image actually supports. */ + r = cg_all_unified(); + if (r < 0) + return log_error_errno(r, "Failed to determine whether we are in all unified mode."); + if (r > 0) { + /* Unified cgroup hierarchy support was added in 230. Unfortunately the detection + * routine only detects 231, so we'll have a false negative here for 230. */ + r = systemd_installation_has_version(directory, "230"); + if (r < 0) + return log_error_errno(r, "Failed to determine systemd version in container: %m"); + if (r > 0) + arg_unified_cgroup_hierarchy = CGROUP_UNIFIED_ALL; + else + arg_unified_cgroup_hierarchy = CGROUP_UNIFIED_NONE; + } else if (cg_unified_controller(SYSTEMD_CGROUP_CONTROLLER) > 0) { + /* Mixed cgroup hierarchy support was added in 233 */ + r = systemd_installation_has_version(directory, "233"); + if (r < 0) + return log_error_errno(r, "Failed to determine systemd version in container: %m"); + if (r > 0) + arg_unified_cgroup_hierarchy = CGROUP_UNIFIED_SYSTEMD; + else + arg_unified_cgroup_hierarchy = CGROUP_UNIFIED_NONE; + } else + arg_unified_cgroup_hierarchy = CGROUP_UNIFIED_NONE; + + log_debug("Using %s hierarchy for container.", + arg_unified_cgroup_hierarchy == CGROUP_UNIFIED_NONE ? "legacy" : + arg_unified_cgroup_hierarchy == CGROUP_UNIFIED_SYSTEMD ? "hybrid" : "unified"); + + return 0; +} + +static int parse_capability_spec(const char *spec, uint64_t *ret_mask) { + uint64_t mask = 0; + int r; + + for (;;) { + _cleanup_free_ char *t = NULL; + + r = extract_first_word(&spec, &t, ",", 0); + if (r < 0) + return log_error_errno(r, "Failed to parse capability %s.", t); + if (r == 0) + break; + + if (streq(t, "help")) { + for (int i = 0; i < capability_list_length(); i++) { + const char *name; + + name = capability_to_name(i); + if (name) + puts(name); + } + + return 0; /* quit */ + } + + if (streq(t, "all")) + mask = UINT64_MAX; + else { + r = capability_from_name(t); + if (r < 0) + return log_error_errno(r, "Failed to parse capability %s.", t); + + mask |= 1ULL << r; + } + } + + *ret_mask = mask; + return 1; /* continue */ +} + +static int parse_share_ns_env(const char *name, unsigned long ns_flag) { + int r; + + r = getenv_bool(name); + if (r == -ENXIO) + return 0; + if (r < 0) + return log_error_errno(r, "Failed to parse $%s: %m", name); + + arg_clone_ns_flags = (arg_clone_ns_flags & ~ns_flag) | (r > 0 ? 0 : ns_flag); + arg_settings_mask |= SETTING_CLONE_NS_FLAGS; + return 0; +} + +static int parse_mount_settings_env(void) { + const char *e; + int r; + + r = getenv_bool("SYSTEMD_NSPAWN_TMPFS_TMP"); + if (r < 0 && r != -ENXIO) + return log_error_errno(r, "Failed to parse $SYSTEMD_NSPAWN_TMPFS_TMP: %m"); + if (r >= 0) + SET_FLAG(arg_mount_settings, MOUNT_APPLY_TMPFS_TMP, r > 0); + + e = getenv("SYSTEMD_NSPAWN_API_VFS_WRITABLE"); + if (streq_ptr(e, "network")) + arg_mount_settings |= MOUNT_APPLY_APIVFS_RO|MOUNT_APPLY_APIVFS_NETNS; + + else if (e) { + r = parse_boolean(e); + if (r < 0) + return log_error_errno(r, "Failed to parse $SYSTEMD_NSPAWN_API_VFS_WRITABLE: %m"); + + SET_FLAG(arg_mount_settings, MOUNT_APPLY_APIVFS_RO, r == 0); + SET_FLAG(arg_mount_settings, MOUNT_APPLY_APIVFS_NETNS, false); + } + + return 0; +} + +static int parse_environment(void) { + const char *e; + int r; + + r = parse_share_ns_env("SYSTEMD_NSPAWN_SHARE_NS_IPC", CLONE_NEWIPC); + if (r < 0) + return r; + r = parse_share_ns_env("SYSTEMD_NSPAWN_SHARE_NS_PID", CLONE_NEWPID); + if (r < 0) + return r; + r = parse_share_ns_env("SYSTEMD_NSPAWN_SHARE_NS_UTS", CLONE_NEWUTS); + if (r < 0) + return r; + r = parse_share_ns_env("SYSTEMD_NSPAWN_SHARE_SYSTEM", CLONE_NEWIPC|CLONE_NEWPID|CLONE_NEWUTS); + if (r < 0) + return r; + + r = parse_mount_settings_env(); + if (r < 0) + return r; + + /* SYSTEMD_NSPAWN_USE_CGNS=0 can be used to disable CLONE_NEWCGROUP use, + * even if it is supported. If not supported, it has no effect. */ + if (!cg_ns_supported()) + arg_use_cgns = false; + else { + r = getenv_bool("SYSTEMD_NSPAWN_USE_CGNS"); + if (r < 0) { + if (r != -ENXIO) + return log_error_errno(r, "Failed to parse $SYSTEMD_NSPAWN_USE_CGNS: %m"); + + arg_use_cgns = true; + } else { + arg_use_cgns = r > 0; + arg_settings_mask |= SETTING_USE_CGNS; + } + } + + e = getenv("SYSTEMD_NSPAWN_CONTAINER_SERVICE"); + if (e) + arg_container_service_name = e; + + r = getenv_bool("SYSTEMD_SUPPRESS_SYNC"); + if (r >= 0) + arg_suppress_sync = r; + else if (r != -ENXIO) + log_debug_errno(r, "Failed to parse $SYSTEMD_SUPPRESS_SYNC, ignoring: %m"); + + return detect_unified_cgroup_hierarchy_from_environment(); +} + +static int parse_argv(int argc, char *argv[]) { + enum { + ARG_VERSION = 0x100, + ARG_PRIVATE_NETWORK, + ARG_UUID, + ARG_READ_ONLY, + ARG_CAPABILITY, + ARG_AMBIENT_CAPABILITY, + ARG_DROP_CAPABILITY, + ARG_LINK_JOURNAL, + ARG_BIND, + ARG_BIND_RO, + ARG_TMPFS, + ARG_OVERLAY, + ARG_OVERLAY_RO, + ARG_INACCESSIBLE, + ARG_SHARE_SYSTEM, + ARG_REGISTER, + ARG_KEEP_UNIT, + ARG_NETWORK_INTERFACE, + ARG_NETWORK_MACVLAN, + ARG_NETWORK_IPVLAN, + ARG_NETWORK_BRIDGE, + ARG_NETWORK_ZONE, + ARG_NETWORK_VETH_EXTRA, + ARG_NETWORK_NAMESPACE_PATH, + ARG_PERSONALITY, + ARG_VOLATILE, + ARG_TEMPLATE, + ARG_PROPERTY, + ARG_PRIVATE_USERS, + ARG_KILL_SIGNAL, + ARG_SETTINGS, + ARG_CHDIR, + ARG_PIVOT_ROOT, + ARG_PRIVATE_USERS_CHOWN, + ARG_PRIVATE_USERS_OWNERSHIP, + ARG_NOTIFY_READY, + ARG_ROOT_HASH, + ARG_ROOT_HASH_SIG, + ARG_VERITY_DATA, + ARG_SYSTEM_CALL_FILTER, + ARG_RLIMIT, + ARG_HOSTNAME, + ARG_NO_NEW_PRIVILEGES, + ARG_OOM_SCORE_ADJUST, + ARG_CPU_AFFINITY, + ARG_RESOLV_CONF, + ARG_TIMEZONE, + ARG_CONSOLE, + ARG_PIPE, + ARG_OCI_BUNDLE, + ARG_NO_PAGER, + ARG_SET_CREDENTIAL, + ARG_LOAD_CREDENTIAL, + ARG_BIND_USER, + ARG_SUPPRESS_SYNC, + }; + + static const struct option options[] = { + { "help", no_argument, NULL, 'h' }, + { "version", no_argument, NULL, ARG_VERSION }, + { "directory", required_argument, NULL, 'D' }, + { "template", required_argument, NULL, ARG_TEMPLATE }, + { "ephemeral", no_argument, NULL, 'x' }, + { "user", required_argument, NULL, 'u' }, + { "private-network", no_argument, NULL, ARG_PRIVATE_NETWORK }, + { "as-pid2", no_argument, NULL, 'a' }, + { "boot", no_argument, NULL, 'b' }, + { "uuid", required_argument, NULL, ARG_UUID }, + { "read-only", no_argument, NULL, ARG_READ_ONLY }, + { "capability", required_argument, NULL, ARG_CAPABILITY }, + { "ambient-capability", required_argument, NULL, ARG_AMBIENT_CAPABILITY }, + { "drop-capability", required_argument, NULL, ARG_DROP_CAPABILITY }, + { "no-new-privileges", required_argument, NULL, ARG_NO_NEW_PRIVILEGES }, + { "link-journal", required_argument, NULL, ARG_LINK_JOURNAL }, + { "bind", required_argument, NULL, ARG_BIND }, + { "bind-ro", required_argument, NULL, ARG_BIND_RO }, + { "tmpfs", required_argument, NULL, ARG_TMPFS }, + { "overlay", required_argument, NULL, ARG_OVERLAY }, + { "overlay-ro", required_argument, NULL, ARG_OVERLAY_RO }, + { "inaccessible", required_argument, NULL, ARG_INACCESSIBLE }, + { "machine", required_argument, NULL, 'M' }, + { "hostname", required_argument, NULL, ARG_HOSTNAME }, + { "slice", required_argument, NULL, 'S' }, + { "setenv", required_argument, NULL, 'E' }, + { "selinux-context", required_argument, NULL, 'Z' }, + { "selinux-apifs-context", required_argument, NULL, 'L' }, + { "quiet", no_argument, NULL, 'q' }, + { "share-system", no_argument, NULL, ARG_SHARE_SYSTEM }, /* not documented */ + { "register", required_argument, NULL, ARG_REGISTER }, + { "keep-unit", no_argument, NULL, ARG_KEEP_UNIT }, + { "network-interface", required_argument, NULL, ARG_NETWORK_INTERFACE }, + { "network-macvlan", required_argument, NULL, ARG_NETWORK_MACVLAN }, + { "network-ipvlan", required_argument, NULL, ARG_NETWORK_IPVLAN }, + { "network-veth", no_argument, NULL, 'n' }, + { "network-veth-extra", required_argument, NULL, ARG_NETWORK_VETH_EXTRA }, + { "network-bridge", required_argument, NULL, ARG_NETWORK_BRIDGE }, + { "network-zone", required_argument, NULL, ARG_NETWORK_ZONE }, + { "network-namespace-path", required_argument, NULL, ARG_NETWORK_NAMESPACE_PATH }, + { "personality", required_argument, NULL, ARG_PERSONALITY }, + { "image", required_argument, NULL, 'i' }, + { "volatile", optional_argument, NULL, ARG_VOLATILE }, + { "port", required_argument, NULL, 'p' }, + { "property", required_argument, NULL, ARG_PROPERTY }, + { "private-users", optional_argument, NULL, ARG_PRIVATE_USERS }, + { "private-users-chown", optional_argument, NULL, ARG_PRIVATE_USERS_CHOWN }, /* obsolete */ + { "private-users-ownership",required_argument, NULL, ARG_PRIVATE_USERS_OWNERSHIP}, + { "kill-signal", required_argument, NULL, ARG_KILL_SIGNAL }, + { "settings", required_argument, NULL, ARG_SETTINGS }, + { "chdir", required_argument, NULL, ARG_CHDIR }, + { "pivot-root", required_argument, NULL, ARG_PIVOT_ROOT }, + { "notify-ready", required_argument, NULL, ARG_NOTIFY_READY }, + { "root-hash", required_argument, NULL, ARG_ROOT_HASH }, + { "root-hash-sig", required_argument, NULL, ARG_ROOT_HASH_SIG }, + { "verity-data", required_argument, NULL, ARG_VERITY_DATA }, + { "system-call-filter", required_argument, NULL, ARG_SYSTEM_CALL_FILTER }, + { "rlimit", required_argument, NULL, ARG_RLIMIT }, + { "oom-score-adjust", required_argument, NULL, ARG_OOM_SCORE_ADJUST }, + { "cpu-affinity", required_argument, NULL, ARG_CPU_AFFINITY }, + { "resolv-conf", required_argument, NULL, ARG_RESOLV_CONF }, + { "timezone", required_argument, NULL, ARG_TIMEZONE }, + { "console", required_argument, NULL, ARG_CONSOLE }, + { "pipe", no_argument, NULL, ARG_PIPE }, + { "oci-bundle", required_argument, NULL, ARG_OCI_BUNDLE }, + { "no-pager", no_argument, NULL, ARG_NO_PAGER }, + { "set-credential", required_argument, NULL, ARG_SET_CREDENTIAL }, + { "load-credential", required_argument, NULL, ARG_LOAD_CREDENTIAL }, + { "bind-user", required_argument, NULL, ARG_BIND_USER }, + { "suppress-sync", required_argument, NULL, ARG_SUPPRESS_SYNC }, + {} + }; + + int c, r; + uint64_t plus = 0, minus = 0; + bool mask_all_settings = false, mask_no_settings = false; + + assert(argc >= 0); + assert(argv); + + /* Resetting to 0 forces the invocation of an internal initialization routine of getopt_long() + * that checks for GNU extensions in optstring ('-' or '+' at the beginning). */ + optind = 0; + while ((c = getopt_long(argc, argv, "+hD:u:abL:M:jS:Z:qi:xp:nUE:P", options, NULL)) >= 0) + switch (c) { + + case 'h': + return help(); + + case ARG_VERSION: + return version(); + + case 'D': + r = parse_path_argument(optarg, false, &arg_directory); + if (r < 0) + return r; + + arg_settings_mask |= SETTING_DIRECTORY; + break; + + case ARG_TEMPLATE: + r = parse_path_argument(optarg, false, &arg_template); + if (r < 0) + return r; + + arg_settings_mask |= SETTING_DIRECTORY; + break; + + case 'i': + r = parse_path_argument(optarg, false, &arg_image); + if (r < 0) + return r; + + arg_settings_mask |= SETTING_DIRECTORY; + break; + + case ARG_OCI_BUNDLE: + r = parse_path_argument(optarg, false, &arg_oci_bundle); + if (r < 0) + return r; + + break; + + case 'x': + arg_ephemeral = true; + arg_settings_mask |= SETTING_EPHEMERAL; + break; + + case 'u': + r = free_and_strdup(&arg_user, optarg); + if (r < 0) + return log_oom(); + + arg_settings_mask |= SETTING_USER; + break; + + case ARG_NETWORK_ZONE: { + char *j; + + j = strjoin("vz-", optarg); + if (!j) + return log_oom(); + + if (!ifname_valid(j)) { + log_error("Network zone name not valid: %s", j); + free(j); + return -EINVAL; + } + + free_and_replace(arg_network_zone, j); + + arg_network_veth = true; + arg_private_network = true; + arg_settings_mask |= SETTING_NETWORK; + break; + } + + case ARG_NETWORK_BRIDGE: + + if (!ifname_valid(optarg)) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), + "Bridge interface name not valid: %s", optarg); + + r = free_and_strdup(&arg_network_bridge, optarg); + if (r < 0) + return log_oom(); + + _fallthrough_; + case 'n': + arg_network_veth = true; + arg_private_network = true; + arg_settings_mask |= SETTING_NETWORK; + break; + + case ARG_NETWORK_VETH_EXTRA: + r = veth_extra_parse(&arg_network_veth_extra, optarg); + if (r < 0) + return log_error_errno(r, "Failed to parse --network-veth-extra= parameter: %s", optarg); + + arg_private_network = true; + arg_settings_mask |= SETTING_NETWORK; + break; + + case ARG_NETWORK_INTERFACE: + if (!ifname_valid(optarg)) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), + "Network interface name not valid: %s", optarg); + + r = test_network_interface_initialized(optarg); + if (r < 0) + return r; + + if (strv_extend(&arg_network_interfaces, optarg) < 0) + return log_oom(); + + arg_private_network = true; + arg_settings_mask |= SETTING_NETWORK; + break; + + case ARG_NETWORK_MACVLAN: + + if (!ifname_valid(optarg)) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), + "MACVLAN network interface name not valid: %s", optarg); + + r = test_network_interface_initialized(optarg); + if (r < 0) + return r; + + if (strv_extend(&arg_network_macvlan, optarg) < 0) + return log_oom(); + + arg_private_network = true; + arg_settings_mask |= SETTING_NETWORK; + break; + + case ARG_NETWORK_IPVLAN: + + if (!ifname_valid(optarg)) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), + "IPVLAN network interface name not valid: %s", optarg); + + r = test_network_interface_initialized(optarg); + if (r < 0) + return r; + + if (strv_extend(&arg_network_ipvlan, optarg) < 0) + return log_oom(); + + _fallthrough_; + case ARG_PRIVATE_NETWORK: + arg_private_network = true; + arg_settings_mask |= SETTING_NETWORK; + break; + + case ARG_NETWORK_NAMESPACE_PATH: + r = parse_path_argument(optarg, false, &arg_network_namespace_path); + if (r < 0) + return r; + + arg_settings_mask |= SETTING_NETWORK; + break; + + case 'b': + if (arg_start_mode == START_PID2) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), + "--boot and --as-pid2 may not be combined."); + + arg_start_mode = START_BOOT; + arg_settings_mask |= SETTING_START_MODE; + break; + + case 'a': + if (arg_start_mode == START_BOOT) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), + "--boot and --as-pid2 may not be combined."); + + arg_start_mode = START_PID2; + arg_settings_mask |= SETTING_START_MODE; + break; + + case ARG_UUID: + r = sd_id128_from_string(optarg, &arg_uuid); + if (r < 0) + return log_error_errno(r, "Invalid UUID: %s", optarg); + + if (sd_id128_is_null(arg_uuid)) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), + "Machine UUID may not be all zeroes."); + + arg_settings_mask |= SETTING_MACHINE_ID; + break; + + case 'S': { + _cleanup_free_ char *mangled = NULL; + + r = unit_name_mangle_with_suffix(optarg, NULL, UNIT_NAME_MANGLE_WARN, ".slice", &mangled); + if (r < 0) + return log_oom(); + + free_and_replace(arg_slice, mangled); + arg_settings_mask |= SETTING_SLICE; + break; + } + + case 'M': + if (isempty(optarg)) + arg_machine = mfree(arg_machine); + else { + if (!hostname_is_valid(optarg, 0)) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), + "Invalid machine name: %s", optarg); + + r = free_and_strdup(&arg_machine, optarg); + if (r < 0) + return log_oom(); + } + break; + + case ARG_HOSTNAME: + if (isempty(optarg)) + arg_hostname = mfree(arg_hostname); + else { + if (!hostname_is_valid(optarg, 0)) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), + "Invalid hostname: %s", optarg); + + r = free_and_strdup(&arg_hostname, optarg); + if (r < 0) + return log_oom(); + } + + arg_settings_mask |= SETTING_HOSTNAME; + break; + + case 'Z': + arg_selinux_context = optarg; + break; + + case 'L': + arg_selinux_apifs_context = optarg; + break; + + case ARG_READ_ONLY: + arg_read_only = true; + arg_settings_mask |= SETTING_READ_ONLY; + break; + + case ARG_AMBIENT_CAPABILITY: { + uint64_t m; + r = parse_capability_spec(optarg, &m); + if (r <= 0) + return r; + arg_caps_ambient |= m; + arg_settings_mask |= SETTING_CAPABILITY; + break; + } + case ARG_CAPABILITY: + case ARG_DROP_CAPABILITY: { + uint64_t m; + r = parse_capability_spec(optarg, &m); + if (r <= 0) + return r; + + if (c == ARG_CAPABILITY) + plus |= m; + else + minus |= m; + arg_settings_mask |= SETTING_CAPABILITY; + break; + } + case ARG_NO_NEW_PRIVILEGES: + r = parse_boolean(optarg); + if (r < 0) + return log_error_errno(r, "Failed to parse --no-new-privileges= argument: %s", optarg); + + arg_no_new_privileges = r; + arg_settings_mask |= SETTING_NO_NEW_PRIVILEGES; + break; + + case 'j': + arg_link_journal = LINK_GUEST; + arg_link_journal_try = true; + arg_settings_mask |= SETTING_LINK_JOURNAL; + break; + + case ARG_LINK_JOURNAL: + r = parse_link_journal(optarg, &arg_link_journal, &arg_link_journal_try); + if (r < 0) + return log_error_errno(r, "Failed to parse link journal mode %s", optarg); + + arg_settings_mask |= SETTING_LINK_JOURNAL; + break; + + case ARG_BIND: + case ARG_BIND_RO: + r = bind_mount_parse(&arg_custom_mounts, &arg_n_custom_mounts, optarg, c == ARG_BIND_RO); + if (r < 0) + return log_error_errno(r, "Failed to parse --bind(-ro)= argument %s: %m", optarg); + + arg_settings_mask |= SETTING_CUSTOM_MOUNTS; + break; + + case ARG_TMPFS: + r = tmpfs_mount_parse(&arg_custom_mounts, &arg_n_custom_mounts, optarg); + if (r < 0) + return log_error_errno(r, "Failed to parse --tmpfs= argument %s: %m", optarg); + + arg_settings_mask |= SETTING_CUSTOM_MOUNTS; + break; + + case ARG_OVERLAY: + case ARG_OVERLAY_RO: + r = overlay_mount_parse(&arg_custom_mounts, &arg_n_custom_mounts, optarg, c == ARG_OVERLAY_RO); + if (r == -EADDRNOTAVAIL) + return log_error_errno(r, "--overlay(-ro)= needs at least two colon-separated directories specified."); + if (r < 0) + return log_error_errno(r, "Failed to parse --overlay(-ro)= argument %s: %m", optarg); + + arg_settings_mask |= SETTING_CUSTOM_MOUNTS; + break; + + case ARG_INACCESSIBLE: + r = inaccessible_mount_parse(&arg_custom_mounts, &arg_n_custom_mounts, optarg); + if (r < 0) + return log_error_errno(r, "Failed to parse --inaccessible= argument %s: %m", optarg); + + arg_settings_mask |= SETTING_CUSTOM_MOUNTS; + break; + + case 'E': + r = strv_env_replace_strdup_passthrough(&arg_setenv, optarg); + if (r < 0) + return log_error_errno(r, "Cannot assign environment variable %s: %m", optarg); + + arg_settings_mask |= SETTING_ENVIRONMENT; + break; + + case 'q': + arg_quiet = true; + break; + + case ARG_SHARE_SYSTEM: + /* We don't officially support this anymore, except for compat reasons. People should use the + * $SYSTEMD_NSPAWN_SHARE_* environment variables instead. */ + log_warning("Please do not use --share-system anymore, use $SYSTEMD_NSPAWN_SHARE_* instead."); + arg_clone_ns_flags = 0; + break; + + case ARG_REGISTER: + r = parse_boolean(optarg); + if (r < 0) { + log_error("Failed to parse --register= argument: %s", optarg); + return r; + } + + arg_register = r; + break; + + case ARG_KEEP_UNIT: + arg_keep_unit = true; + break; + + case ARG_PERSONALITY: + + arg_personality = personality_from_string(optarg); + if (arg_personality == PERSONALITY_INVALID) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), + "Unknown or unsupported personality '%s'.", optarg); + + arg_settings_mask |= SETTING_PERSONALITY; + break; + + case ARG_VOLATILE: + + if (!optarg) + arg_volatile_mode = VOLATILE_YES; + else if (streq(optarg, "help")) { + DUMP_STRING_TABLE(volatile_mode, VolatileMode, _VOLATILE_MODE_MAX); + return 0; + } else { + VolatileMode m; + + m = volatile_mode_from_string(optarg); + if (m < 0) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), + "Failed to parse --volatile= argument: %s", optarg); + else + arg_volatile_mode = m; + } + + arg_settings_mask |= SETTING_VOLATILE_MODE; + break; + + case 'p': + r = expose_port_parse(&arg_expose_ports, optarg); + if (r == -EEXIST) + return log_error_errno(r, "Duplicate port specification: %s", optarg); + if (r < 0) + return log_error_errno(r, "Failed to parse host port %s: %m", optarg); + + arg_settings_mask |= SETTING_EXPOSE_PORTS; + break; + + case ARG_PROPERTY: + if (strv_extend(&arg_property, optarg) < 0) + return log_oom(); + + break; + + case ARG_PRIVATE_USERS: { + int boolean; + + if (!optarg) + boolean = true; + else if (!in_charset(optarg, DIGITS)) + /* do *not* parse numbers as booleans */ + boolean = parse_boolean(optarg); + else + boolean = -1; + + if (boolean == 0) { + /* no: User namespacing off */ + arg_userns_mode = USER_NAMESPACE_NO; + arg_uid_shift = UID_INVALID; + arg_uid_range = UINT32_C(0x10000); + } else if (boolean > 0) { + /* yes: User namespacing on, UID range is read from root dir */ + arg_userns_mode = USER_NAMESPACE_FIXED; + arg_uid_shift = UID_INVALID; + arg_uid_range = UINT32_C(0x10000); + } else if (streq(optarg, "pick")) { + /* pick: User namespacing on, UID range is picked randomly */ + arg_userns_mode = USER_NAMESPACE_PICK; /* Note that arg_userns_ownership is + * implied by USER_NAMESPACE_PICK + * further down. */ + arg_uid_shift = UID_INVALID; + arg_uid_range = UINT32_C(0x10000); + + } else if (streq(optarg, "identity")) { + /* identitiy: User namespaces on, UID range is map the 0…0xFFFF range to + * itself, i.e. we don't actually map anything, but do take benefit of + * isolation of capability sets. */ + arg_userns_mode = USER_NAMESPACE_FIXED; + arg_uid_shift = 0; + arg_uid_range = UINT32_C(0x10000); + } else { + _cleanup_free_ char *buffer = NULL; + const char *range, *shift; + + /* anything else: User namespacing on, UID range is explicitly configured */ + + range = strchr(optarg, ':'); + if (range) { + buffer = strndup(optarg, range - optarg); + if (!buffer) + return log_oom(); + shift = buffer; + + range++; + r = safe_atou32(range, &arg_uid_range); + if (r < 0) + return log_error_errno(r, "Failed to parse UID range \"%s\": %m", range); + } else + shift = optarg; + + r = parse_uid(shift, &arg_uid_shift); + if (r < 0) + return log_error_errno(r, "Failed to parse UID \"%s\": %m", optarg); + + arg_userns_mode = USER_NAMESPACE_FIXED; + + if (!userns_shift_range_valid(arg_uid_shift, arg_uid_range)) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "UID range cannot be empty or go beyond " UID_FMT ".", UID_INVALID); + } + + arg_settings_mask |= SETTING_USERNS; + break; + } + + case 'U': + if (userns_supported()) { + arg_userns_mode = USER_NAMESPACE_PICK; /* Note that arg_userns_ownership is + * implied by USER_NAMESPACE_PICK + * further down. */ + arg_uid_shift = UID_INVALID; + arg_uid_range = UINT32_C(0x10000); + + arg_settings_mask |= SETTING_USERNS; + } + + break; + + case ARG_PRIVATE_USERS_CHOWN: + arg_userns_ownership = USER_NAMESPACE_OWNERSHIP_CHOWN; + + arg_settings_mask |= SETTING_USERNS; + break; + + case ARG_PRIVATE_USERS_OWNERSHIP: + if (streq(optarg, "help")) { + DUMP_STRING_TABLE(user_namespace_ownership, UserNamespaceOwnership, _USER_NAMESPACE_OWNERSHIP_MAX); + return 0; + } + + arg_userns_ownership = user_namespace_ownership_from_string(optarg); + if (arg_userns_ownership < 0) + return log_error_errno(arg_userns_ownership, "Cannot parse --user-namespace-ownership= value: %s", optarg); + + arg_settings_mask |= SETTING_USERNS; + break; + + case ARG_KILL_SIGNAL: + if (streq(optarg, "help")) { + DUMP_STRING_TABLE(signal, int, _NSIG); + return 0; + } + + arg_kill_signal = signal_from_string(optarg); + if (arg_kill_signal < 0) + return log_error_errno(arg_kill_signal, "Cannot parse signal: %s", optarg); + + arg_settings_mask |= SETTING_KILL_SIGNAL; + break; + + case ARG_SETTINGS: + + /* no → do not read files + * yes → read files, do not override cmdline, trust only subset + * override → read files, override cmdline, trust only subset + * trusted → read files, do not override cmdline, trust all + */ + + r = parse_boolean(optarg); + if (r < 0) { + if (streq(optarg, "trusted")) { + mask_all_settings = false; + mask_no_settings = false; + arg_settings_trusted = true; + + } else if (streq(optarg, "override")) { + mask_all_settings = false; + mask_no_settings = true; + arg_settings_trusted = -1; + } else + return log_error_errno(r, "Failed to parse --settings= argument: %s", optarg); + } else if (r > 0) { + /* yes */ + mask_all_settings = false; + mask_no_settings = false; + arg_settings_trusted = -1; + } else { + /* no */ + mask_all_settings = true; + mask_no_settings = false; + arg_settings_trusted = false; + } + + break; + + case ARG_CHDIR: + if (!path_is_absolute(optarg)) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), + "Working directory %s is not an absolute path.", optarg); + + r = free_and_strdup(&arg_chdir, optarg); + if (r < 0) + return log_oom(); + + arg_settings_mask |= SETTING_WORKING_DIRECTORY; + break; + + case ARG_PIVOT_ROOT: + r = pivot_root_parse(&arg_pivot_root_new, &arg_pivot_root_old, optarg); + if (r < 0) + return log_error_errno(r, "Failed to parse --pivot-root= argument %s: %m", optarg); + + arg_settings_mask |= SETTING_PIVOT_ROOT; + break; + + case ARG_NOTIFY_READY: + r = parse_boolean(optarg); + if (r < 0) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), + "%s is not a valid notify mode. Valid modes are: yes, no, and ready.", optarg); + arg_notify_ready = r; + arg_settings_mask |= SETTING_NOTIFY_READY; + break; + + case ARG_ROOT_HASH: { + _cleanup_free_ void *k = NULL; + size_t l; + + r = unhexmem(optarg, strlen(optarg), &k, &l); + if (r < 0) + return log_error_errno(r, "Failed to parse root hash: %s", optarg); + if (l < sizeof(sd_id128_t)) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Root hash must be at least 128bit long: %s", optarg); + + free_and_replace(arg_verity_settings.root_hash, k); + arg_verity_settings.root_hash_size = l; + break; + } + + case ARG_ROOT_HASH_SIG: { + char *value; + size_t l; + void *p; + + if ((value = startswith(optarg, "base64:"))) { + r = unbase64mem(value, strlen(value), &p, &l); + if (r < 0) + return log_error_errno(r, "Failed to parse root hash signature '%s': %m", optarg); + + } else { + r = read_full_file(optarg, (char**) &p, &l); + if (r < 0) + return log_error_errno(r, "Failed parse root hash signature file '%s': %m", optarg); + } + + free_and_replace(arg_verity_settings.root_hash_sig, p); + arg_verity_settings.root_hash_sig_size = l; + break; + } + + case ARG_VERITY_DATA: + r = parse_path_argument(optarg, false, &arg_verity_settings.data_path); + if (r < 0) + return r; + break; + + case ARG_SYSTEM_CALL_FILTER: { + bool negative; + const char *items; + + negative = optarg[0] == '~'; + items = negative ? optarg + 1 : optarg; + + for (;;) { + _cleanup_free_ char *word = NULL; + + r = extract_first_word(&items, &word, NULL, 0); + if (r == 0) + break; + if (r == -ENOMEM) + return log_oom(); + if (r < 0) + return log_error_errno(r, "Failed to parse system call filter: %m"); + + if (negative) + r = strv_extend(&arg_syscall_deny_list, word); + else + r = strv_extend(&arg_syscall_allow_list, word); + if (r < 0) + return log_oom(); + } + + arg_settings_mask |= SETTING_SYSCALL_FILTER; + break; + } + + case ARG_RLIMIT: { + const char *eq; + _cleanup_free_ char *name = NULL; + int rl; + + if (streq(optarg, "help")) { + DUMP_STRING_TABLE(rlimit, int, _RLIMIT_MAX); + return 0; + } + + eq = strchr(optarg, '='); + if (!eq) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), + "--rlimit= expects an '=' assignment."); + + name = strndup(optarg, eq - optarg); + if (!name) + return log_oom(); + + rl = rlimit_from_string_harder(name); + if (rl < 0) + return log_error_errno(rl, "Unknown resource limit: %s", name); + + if (!arg_rlimit[rl]) { + arg_rlimit[rl] = new0(struct rlimit, 1); + if (!arg_rlimit[rl]) + return log_oom(); + } + + r = rlimit_parse(rl, eq + 1, arg_rlimit[rl]); + if (r < 0) + return log_error_errno(r, "Failed to parse resource limit: %s", eq + 1); + + arg_settings_mask |= SETTING_RLIMIT_FIRST << rl; + break; + } + + case ARG_OOM_SCORE_ADJUST: + r = parse_oom_score_adjust(optarg, &arg_oom_score_adjust); + if (r < 0) + return log_error_errno(r, "Failed to parse --oom-score-adjust= parameter: %s", optarg); + + arg_oom_score_adjust_set = true; + arg_settings_mask |= SETTING_OOM_SCORE_ADJUST; + break; + + case ARG_CPU_AFFINITY: { + CPUSet cpuset; + + r = parse_cpu_set(optarg, &cpuset); + if (r < 0) + return log_error_errno(r, "Failed to parse CPU affinity mask %s: %m", optarg); + + cpu_set_reset(&arg_cpu_set); + arg_cpu_set = cpuset; + arg_settings_mask |= SETTING_CPU_AFFINITY; + break; + } + + case ARG_RESOLV_CONF: + if (streq(optarg, "help")) { + DUMP_STRING_TABLE(resolv_conf_mode, ResolvConfMode, _RESOLV_CONF_MODE_MAX); + return 0; + } + + arg_resolv_conf = resolv_conf_mode_from_string(optarg); + if (arg_resolv_conf < 0) + return log_error_errno(arg_resolv_conf, + "Failed to parse /etc/resolv.conf mode: %s", optarg); + + arg_settings_mask |= SETTING_RESOLV_CONF; + break; + + case ARG_TIMEZONE: + if (streq(optarg, "help")) { + DUMP_STRING_TABLE(timezone_mode, TimezoneMode, _TIMEZONE_MODE_MAX); + return 0; + } + + arg_timezone = timezone_mode_from_string(optarg); + if (arg_timezone < 0) + return log_error_errno(arg_timezone, + "Failed to parse /etc/localtime mode: %s", optarg); + + arg_settings_mask |= SETTING_TIMEZONE; + break; + + case ARG_CONSOLE: + r = handle_arg_console(optarg); + if (r <= 0) + return r; + break; + + case 'P': + case ARG_PIPE: + r = handle_arg_console("pipe"); + if (r <= 0) + return r; + break; + + case ARG_NO_PAGER: + arg_pager_flags |= PAGER_DISABLE; + break; + + case ARG_SET_CREDENTIAL: { + _cleanup_free_ char *word = NULL, *data = NULL; + const char *p = optarg; + Credential *a; + ssize_t l; + + r = extract_first_word(&p, &word, ":", EXTRACT_DONT_COALESCE_SEPARATORS); + if (r == -ENOMEM) + return log_oom(); + if (r < 0) + return log_error_errno(r, "Failed to parse --set-credential= parameter: %m"); + if (r == 0 || !p) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Missing value for --set-credential=: %s", optarg); + + if (!credential_name_valid(word)) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Credential name is not valid: %s", word); + + for (size_t i = 0; i < arg_n_credentials; i++) + if (streq(arg_credentials[i].id, word)) + return log_error_errno(SYNTHETIC_ERRNO(EEXIST), "Duplicate credential '%s', refusing.", word); + + l = cunescape(p, UNESCAPE_ACCEPT_NUL, &data); + if (l < 0) + return log_error_errno(l, "Failed to unescape credential data: %s", p); + + a = reallocarray(arg_credentials, arg_n_credentials + 1, sizeof(Credential)); + if (!a) + return log_oom(); + + a[arg_n_credentials++] = (Credential) { + .id = TAKE_PTR(word), + .data = TAKE_PTR(data), + .size = l, + }; + + arg_credentials = a; + + arg_settings_mask |= SETTING_CREDENTIALS; + break; + } + + case ARG_LOAD_CREDENTIAL: { + ReadFullFileFlags flags = READ_FULL_FILE_SECURE; + _cleanup_(erase_and_freep) char *data = NULL; + _cleanup_free_ char *word = NULL, *j = NULL; + const char *p = optarg; + Credential *a; + size_t size, i; + + r = extract_first_word(&p, &word, ":", EXTRACT_DONT_COALESCE_SEPARATORS); + if (r == -ENOMEM) + return log_oom(); + if (r < 0) + return log_error_errno(r, "Failed to parse --load-credential= parameter: %m"); + if (r == 0 || !p) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Missing value for --load-credential=: %s", optarg); + + if (!credential_name_valid(word)) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Credential name is not valid: %s", word); + + for (i = 0; i < arg_n_credentials; i++) + if (streq(arg_credentials[i].id, word)) + return log_error_errno(SYNTHETIC_ERRNO(EEXIST), "Duplicate credential '%s', refusing.", word); + + if (path_is_absolute(p)) + flags |= READ_FULL_FILE_CONNECT_SOCKET; + else { + const char *e; + + r = get_credentials_dir(&e); + if (r < 0) + return log_error_errno(r, "Credential not available (no credentials passed at all): %s", word); + + j = path_join(e, p); + if (!j) + return log_oom(); + } + + r = read_full_file_full(AT_FDCWD, j ?: p, UINT64_MAX, SIZE_MAX, + flags, + NULL, + &data, &size); + if (r < 0) + return log_error_errno(r, "Failed to read credential '%s': %m", j ?: p); + + a = reallocarray(arg_credentials, arg_n_credentials + 1, sizeof(Credential)); + if (!a) + return log_oom(); + + a[arg_n_credentials++] = (Credential) { + .id = TAKE_PTR(word), + .data = TAKE_PTR(data), + .size = size, + }; + + arg_credentials = a; + + arg_settings_mask |= SETTING_CREDENTIALS; + break; + } + + case ARG_BIND_USER: + if (!valid_user_group_name(optarg, 0)) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Invalid user name to bind: %s", optarg); + + if (strv_extend(&arg_bind_user, optarg) < 0) + return log_oom(); + + arg_settings_mask |= SETTING_BIND_USER; + break; + + case ARG_SUPPRESS_SYNC: + r = parse_boolean_argument("--suppress-sync=", optarg, &arg_suppress_sync); + if (r < 0) + return r; + + arg_settings_mask |= SETTING_SUPPRESS_SYNC; + break; + + case '?': + return -EINVAL; + + default: + assert_not_reached(); + } + + if (argc > optind) { + strv_free(arg_parameters); + arg_parameters = strv_copy(argv + optind); + if (!arg_parameters) + return log_oom(); + + arg_settings_mask |= SETTING_START_MODE; + } + + if (arg_ephemeral && arg_template && !arg_directory) + /* User asked for ephemeral execution but specified --template= instead of --directory=. Semantically + * such an invocation makes some sense, see https://github.com/systemd/systemd/issues/3667. Let's + * accept this here, and silently make "--ephemeral --template=" equivalent to "--ephemeral + * --directory=". */ + arg_directory = TAKE_PTR(arg_template); + + arg_caps_retain |= plus; + arg_caps_retain |= arg_private_network ? UINT64_C(1) << CAP_NET_ADMIN : 0; + arg_caps_retain &= ~minus; + + /* Make sure to parse environment before we reset the settings mask below */ + r = parse_environment(); + if (r < 0) + return r; + + /* Load all settings from .nspawn files */ + if (mask_no_settings) + arg_settings_mask = 0; + + /* Don't load any settings from .nspawn files */ + if (mask_all_settings) + arg_settings_mask = _SETTINGS_MASK_ALL; + + return 1; +} + +static int verify_arguments(void) { + int r; + + if (arg_start_mode == START_PID2 && arg_unified_cgroup_hierarchy == CGROUP_UNIFIED_UNKNOWN) { + /* If we are running the stub init in the container, we don't need to look at what the init + * in the container supports, because we are not using it. Let's immediately pick the right + * setting based on the host system configuration. + * + * We only do this, if the user didn't use an environment variable to override the detection. + */ + + r = cg_all_unified(); + if (r < 0) + return log_error_errno(r, "Failed to determine whether we are in all unified mode."); + if (r > 0) + arg_unified_cgroup_hierarchy = CGROUP_UNIFIED_ALL; + else if (cg_unified_controller(SYSTEMD_CGROUP_CONTROLLER) > 0) + arg_unified_cgroup_hierarchy = CGROUP_UNIFIED_SYSTEMD; + else + arg_unified_cgroup_hierarchy = CGROUP_UNIFIED_NONE; + } + + if (arg_userns_mode != USER_NAMESPACE_NO) + arg_mount_settings |= MOUNT_USE_USERNS; + + if (arg_private_network) + arg_mount_settings |= MOUNT_APPLY_APIVFS_NETNS; + + if (!(arg_clone_ns_flags & CLONE_NEWPID) || + !(arg_clone_ns_flags & CLONE_NEWUTS)) { + arg_register = false; + if (arg_start_mode != START_PID1) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "--boot cannot be used without namespacing."); + } + + if (arg_userns_ownership < 0) + arg_userns_ownership = + arg_userns_mode == USER_NAMESPACE_PICK ? USER_NAMESPACE_OWNERSHIP_AUTO : + USER_NAMESPACE_OWNERSHIP_OFF; + + if (arg_start_mode == START_BOOT && arg_kill_signal <= 0) + arg_kill_signal = SIGRTMIN+3; + + if (arg_volatile_mode != VOLATILE_NO) /* Make sure all file systems contained in the image are mounted read-only if we are in volatile mode */ + arg_read_only = true; + + if (has_custom_root_mount(arg_custom_mounts, arg_n_custom_mounts)) + arg_read_only = true; + + if (arg_keep_unit && arg_register && cg_pid_get_owner_uid(0, NULL) >= 0) + /* Save the user from accidentally registering either user-$SESSION.scope or user@.service. + * The latter is not technically a user session, but we don't need to labour the point. */ + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "--keep-unit --register=yes may not be used when invoked from a user session."); + + if (arg_directory && arg_image) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "--directory= and --image= may not be combined."); + + if (arg_template && arg_image) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "--template= and --image= may not be combined."); + + if (arg_template && !(arg_directory || arg_machine)) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "--template= needs --directory= or --machine=."); + + if (arg_ephemeral && arg_template) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "--ephemeral and --template= may not be combined."); + + if (arg_ephemeral && !IN_SET(arg_link_journal, LINK_NO, LINK_AUTO)) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "--ephemeral and --link-journal= may not be combined."); + + if (arg_userns_mode != USER_NAMESPACE_NO && !userns_supported()) + return log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "--private-users= is not supported, kernel compiled without user namespace support."); + + if (arg_userns_ownership == USER_NAMESPACE_OWNERSHIP_CHOWN && arg_read_only) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), + "--read-only and --private-users-ownership=chown may not be combined."); + + /* We don't support --private-users-ownership=chown together with any of the volatile modes since we + * couldn't change the read-only part of the tree (i.e. /usr) anyway, or because it would trigger a + * massive copy-up (in case of overlay) making the entire exercise pointless. */ + if (arg_userns_ownership == USER_NAMESPACE_OWNERSHIP_CHOWN && arg_volatile_mode != VOLATILE_NO) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "--volatile= and --private-users-ownership=chown may not be combined."); + + /* If --network-namespace-path is given with any other network-related option (except --private-network), + * we need to error out, to avoid conflicts between different network options. */ + if (arg_network_namespace_path && + (arg_network_interfaces || arg_network_macvlan || + arg_network_ipvlan || arg_network_veth_extra || + arg_network_bridge || arg_network_zone || + arg_network_veth)) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "--network-namespace-path= cannot be combined with other network options."); + + if (arg_network_bridge && arg_network_zone) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), + "--network-bridge= and --network-zone= may not be combined."); + + if (arg_userns_mode != USER_NAMESPACE_NO && (arg_mount_settings & MOUNT_APPLY_APIVFS_NETNS) && !arg_private_network) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Invalid namespacing settings. Mounting sysfs with --private-users requires --private-network."); + + if (arg_userns_mode != USER_NAMESPACE_NO && !(arg_mount_settings & MOUNT_APPLY_APIVFS_RO)) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Cannot combine --private-users with read-write mounts."); + + if (arg_expose_ports && !arg_private_network) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Cannot use --port= without private networking."); + + if (arg_caps_ambient) { + if (arg_caps_ambient == UINT64_MAX) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "AmbientCapability= does not support the value all."); + + if ((arg_caps_ambient & arg_caps_retain) != arg_caps_ambient) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "AmbientCapability= setting is not fully covered by Capability= setting."); + + if (arg_start_mode == START_BOOT) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "AmbientCapability= setting is not useful for boot mode."); + } + + if (arg_userns_mode == USER_NAMESPACE_NO && !strv_isempty(arg_bind_user)) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "--bind-user= requires --private-users"); + + /* Drop duplicate --bind-user= entries */ + strv_uniq(arg_bind_user); + + r = custom_mount_check_all(); + if (r < 0) + return r; + + return 0; +} + +int userns_lchown(const char *p, uid_t uid, gid_t gid) { + assert(p); + + if (arg_userns_mode == USER_NAMESPACE_NO) + return 0; + + if (uid == UID_INVALID && gid == GID_INVALID) + return 0; + + if (uid != UID_INVALID) { + uid += arg_uid_shift; + + if (uid < arg_uid_shift || uid >= arg_uid_shift + arg_uid_range) + return -EOVERFLOW; + } + + if (gid != GID_INVALID) { + gid += (gid_t) arg_uid_shift; + + if (gid < (gid_t) arg_uid_shift || gid >= (gid_t) (arg_uid_shift + arg_uid_range)) + return -EOVERFLOW; + } + + return RET_NERRNO(lchown(p, uid, gid)); +} + +int userns_mkdir(const char *root, const char *path, mode_t mode, uid_t uid, gid_t gid) { + const char *q; + int r; + + q = prefix_roota(root, path); + r = RET_NERRNO(mkdir(q, mode)); + if (r == -EEXIST) + return 0; + if (r < 0) + return r; + + return userns_lchown(q, uid, gid); +} + +static const char *timezone_from_path(const char *path) { + return PATH_STARTSWITH_SET( + path, + "../usr/share/zoneinfo/", + "/usr/share/zoneinfo/"); +} + +static bool etc_writable(void) { + return !arg_read_only || IN_SET(arg_volatile_mode, VOLATILE_YES, VOLATILE_OVERLAY); +} + +static int setup_timezone(const char *dest) { + _cleanup_free_ char *p = NULL, *etc = NULL; + const char *where, *check; + TimezoneMode m; + int r; + + assert(dest); + + if (IN_SET(arg_timezone, TIMEZONE_AUTO, TIMEZONE_SYMLINK)) { + r = readlink_malloc("/etc/localtime", &p); + if (r == -ENOENT && arg_timezone == TIMEZONE_AUTO) + m = etc_writable() ? TIMEZONE_DELETE : TIMEZONE_OFF; + else if (r == -EINVAL && arg_timezone == TIMEZONE_AUTO) /* regular file? */ + m = etc_writable() ? TIMEZONE_COPY : TIMEZONE_BIND; + else if (r < 0) { + log_warning_errno(r, "Failed to read host's /etc/localtime symlink, not updating container timezone: %m"); + /* To handle warning, delete /etc/localtime and replace it with a symbolic link to a time zone data + * file. + * + * Example: + * ln -s /usr/share/zoneinfo/UTC /etc/localtime + */ + return 0; + } else if (arg_timezone == TIMEZONE_AUTO) + m = etc_writable() ? TIMEZONE_SYMLINK : TIMEZONE_BIND; + else + m = arg_timezone; + } else + m = arg_timezone; + + if (m == TIMEZONE_OFF) + return 0; + + r = chase_symlinks("/etc", dest, CHASE_PREFIX_ROOT, &etc, NULL); + if (r < 0) { + log_warning_errno(r, "Failed to resolve /etc path in container, ignoring: %m"); + return 0; + } + + where = strjoina(etc, "/localtime"); + + switch (m) { + + case TIMEZONE_DELETE: + if (unlink(where) < 0) + log_full_errno(errno == ENOENT ? LOG_DEBUG : LOG_WARNING, errno, "Failed to remove '%s', ignoring: %m", where); + + return 0; + + case TIMEZONE_SYMLINK: { + _cleanup_free_ char *q = NULL; + const char *z, *what; + + z = timezone_from_path(p); + if (!z) { + log_warning("/etc/localtime does not point into /usr/share/zoneinfo/, not updating container timezone."); + return 0; + } + + r = readlink_malloc(where, &q); + if (r >= 0 && streq_ptr(timezone_from_path(q), z)) + return 0; /* Already pointing to the right place? Then do nothing .. */ + + check = strjoina(dest, "/usr/share/zoneinfo/", z); + r = chase_symlinks(check, dest, 0, NULL, NULL); + if (r < 0) + log_debug_errno(r, "Timezone %s does not exist (or is not accessible) in container, not creating symlink: %m", z); + else { + if (unlink(where) < 0 && errno != ENOENT) { + log_full_errno(IN_SET(errno, EROFS, EACCES, EPERM) ? LOG_DEBUG : LOG_WARNING, /* Don't complain on read-only images */ + errno, "Failed to remove existing timezone info %s in container, ignoring: %m", where); + return 0; + } + + what = strjoina("../usr/share/zoneinfo/", z); + if (symlink(what, where) < 0) { + log_full_errno(IN_SET(errno, EROFS, EACCES, EPERM) ? LOG_DEBUG : LOG_WARNING, + errno, "Failed to correct timezone of container, ignoring: %m"); + return 0; + } + + break; + } + + _fallthrough_; + } + + case TIMEZONE_BIND: { + _cleanup_free_ char *resolved = NULL; + int found; + + found = chase_symlinks(where, dest, CHASE_NONEXISTENT, &resolved, NULL); + if (found < 0) { + log_warning_errno(found, "Failed to resolve /etc/localtime path in container, ignoring: %m"); + return 0; + } + + if (found == 0) /* missing? */ + (void) touch(resolved); + + r = mount_nofollow_verbose(LOG_WARNING, "/etc/localtime", resolved, NULL, MS_BIND, NULL); + if (r >= 0) + return mount_nofollow_verbose(LOG_ERR, NULL, resolved, NULL, MS_BIND|MS_REMOUNT|MS_RDONLY|MS_NOSUID|MS_NODEV, NULL); + + _fallthrough_; + } + + case TIMEZONE_COPY: + /* If mounting failed, try to copy */ + r = copy_file_atomic("/etc/localtime", where, 0644, 0, 0, COPY_REFLINK|COPY_REPLACE); + if (r < 0) { + log_full_errno(IN_SET(r, -EROFS, -EACCES, -EPERM) ? LOG_DEBUG : LOG_WARNING, r, + "Failed to copy /etc/localtime to %s, ignoring: %m", where); + return 0; + } + + break; + + default: + assert_not_reached(); + } + + /* Fix permissions of the symlink or file copy we just created */ + r = userns_lchown(where, 0, 0); + if (r < 0) + log_warning_errno(r, "Failed to chown /etc/localtime, ignoring: %m"); + + return 0; +} + +static int have_resolv_conf(const char *path) { + assert(path); + + if (access(path, F_OK) < 0) { + if (errno == ENOENT) + return 0; + + return log_debug_errno(errno, "Failed to determine whether '%s' is available: %m", path); + } + + return 1; +} + +static int resolved_listening(void) { + _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL; + _cleanup_(sd_bus_flush_close_unrefp) sd_bus *bus = NULL; + _cleanup_free_ char *dns_stub_listener_mode = NULL; + int r; + + /* Check if resolved is listening */ + + r = sd_bus_open_system(&bus); + if (r < 0) + return log_debug_errno(r, "Failed to open system bus: %m"); + + r = bus_name_has_owner(bus, "org.freedesktop.resolve1", NULL); + if (r < 0) + return log_debug_errno(r, "Failed to check whether the 'org.freedesktop.resolve1' bus name is taken: %m"); + if (r == 0) + return 0; + + r = sd_bus_get_property_string(bus, + "org.freedesktop.resolve1", + "/org/freedesktop/resolve1", + "org.freedesktop.resolve1.Manager", + "DNSStubListener", + &error, + &dns_stub_listener_mode); + if (r < 0) + return log_debug_errno(r, "Failed to query DNSStubListener property: %s", bus_error_message(&error, r)); + + return STR_IN_SET(dns_stub_listener_mode, "udp", "yes"); +} + +static int setup_resolv_conf(const char *dest) { + _cleanup_free_ char *etc = NULL; + const char *where, *what; + ResolvConfMode m; + int r; + + assert(dest); + + if (arg_resolv_conf == RESOLV_CONF_AUTO) { + if (arg_private_network) + m = RESOLV_CONF_OFF; + else if (have_resolv_conf(PRIVATE_STUB_RESOLV_CONF) > 0 && resolved_listening() > 0) + m = etc_writable() ? RESOLV_CONF_COPY_STUB : RESOLV_CONF_BIND_STUB; + else if (have_resolv_conf("/etc/resolv.conf") > 0) + m = etc_writable() ? RESOLV_CONF_COPY_HOST : RESOLV_CONF_BIND_HOST; + else + m = etc_writable() ? RESOLV_CONF_DELETE : RESOLV_CONF_OFF; + + } else + m = arg_resolv_conf; + + if (m == RESOLV_CONF_OFF) + return 0; + + r = chase_symlinks("/etc", dest, CHASE_PREFIX_ROOT, &etc, NULL); + if (r < 0) { + log_warning_errno(r, "Failed to resolve /etc path in container, ignoring: %m"); + return 0; + } + + where = strjoina(etc, "/resolv.conf"); + + if (m == RESOLV_CONF_DELETE) { + if (unlink(where) < 0) + log_full_errno(errno == ENOENT ? LOG_DEBUG : LOG_WARNING, errno, "Failed to remove '%s', ignoring: %m", where); + + return 0; + } + + if (IN_SET(m, RESOLV_CONF_BIND_STATIC, RESOLV_CONF_REPLACE_STATIC, RESOLV_CONF_COPY_STATIC)) + what = PRIVATE_STATIC_RESOLV_CONF; + else if (IN_SET(m, RESOLV_CONF_BIND_UPLINK, RESOLV_CONF_REPLACE_UPLINK, RESOLV_CONF_COPY_UPLINK)) + what = PRIVATE_UPLINK_RESOLV_CONF; + else if (IN_SET(m, RESOLV_CONF_BIND_STUB, RESOLV_CONF_REPLACE_STUB, RESOLV_CONF_COPY_STUB)) + what = PRIVATE_STUB_RESOLV_CONF; + else + what = "/etc/resolv.conf"; + + if (IN_SET(m, RESOLV_CONF_BIND_HOST, RESOLV_CONF_BIND_STATIC, RESOLV_CONF_BIND_UPLINK, RESOLV_CONF_BIND_STUB)) { + _cleanup_free_ char *resolved = NULL; + int found; + + found = chase_symlinks(where, dest, CHASE_NONEXISTENT, &resolved, NULL); + if (found < 0) { + log_warning_errno(found, "Failed to resolve /etc/resolv.conf path in container, ignoring: %m"); + return 0; + } + + if (found == 0) /* missing? */ + (void) touch(resolved); + + r = mount_nofollow_verbose(LOG_WARNING, what, resolved, NULL, MS_BIND, NULL); + if (r >= 0) + return mount_nofollow_verbose(LOG_ERR, NULL, resolved, NULL, MS_BIND|MS_REMOUNT|MS_RDONLY|MS_NOSUID|MS_NODEV, NULL); + + /* If that didn't work, let's copy the file */ + } + + if (IN_SET(m, RESOLV_CONF_REPLACE_HOST, RESOLV_CONF_REPLACE_STATIC, RESOLV_CONF_REPLACE_UPLINK, RESOLV_CONF_REPLACE_STUB)) + r = copy_file_atomic(what, where, 0644, 0, 0, COPY_REFLINK|COPY_REPLACE); + else + r = copy_file(what, where, O_TRUNC|O_NOFOLLOW, 0644, 0, 0, COPY_REFLINK); + if (r < 0) { + /* If the file already exists as symlink, let's suppress the warning, under the assumption that + * resolved or something similar runs inside and the symlink points there. + * + * If the disk image is read-only, there's also no point in complaining. + */ + log_full_errno(!IN_SET(RESOLV_CONF_COPY_HOST, RESOLV_CONF_COPY_STATIC, RESOLV_CONF_COPY_UPLINK, RESOLV_CONF_COPY_STUB) && + IN_SET(r, -ELOOP, -EROFS, -EACCES, -EPERM) ? LOG_DEBUG : LOG_WARNING, r, + "Failed to copy /etc/resolv.conf to %s, ignoring: %m", where); + return 0; + } + + r = userns_lchown(where, 0, 0); + if (r < 0) + log_warning_errno(r, "Failed to chown /etc/resolv.conf, ignoring: %m"); + + return 0; +} + +static int setup_boot_id(void) { + _cleanup_(unlink_and_freep) char *from = NULL; + _cleanup_free_ char *path = NULL; + sd_id128_t rnd = SD_ID128_NULL; + const char *to; + int r; + + /* Generate a new randomized boot ID, so that each boot-up of the container gets a new one */ + + r = tempfn_random_child("/run", "proc-sys-kernel-random-boot-id", &path); + if (r < 0) + return log_error_errno(r, "Failed to generate random boot ID path: %m"); + + r = sd_id128_randomize(&rnd); + if (r < 0) + return log_error_errno(r, "Failed to generate random boot id: %m"); + + r = id128_write(path, ID128_FORMAT_UUID, rnd, false); + if (r < 0) + return log_error_errno(r, "Failed to write boot id: %m"); + + from = TAKE_PTR(path); + to = "/proc/sys/kernel/random/boot_id"; + + r = mount_nofollow_verbose(LOG_ERR, from, to, NULL, MS_BIND, NULL); + if (r < 0) + return r; + + return mount_nofollow_verbose(LOG_ERR, NULL, to, NULL, MS_BIND|MS_REMOUNT|MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV, NULL); +} + +static int copy_devnodes(const char *dest) { + static const char devnodes[] = + "null\0" + "zero\0" + "full\0" + "random\0" + "urandom\0" + "tty\0" + "net/tun\0"; + + const char *d; + int r = 0; + + assert(dest); + + BLOCK_WITH_UMASK(0000); + + /* Create /dev/net, so that we can create /dev/net/tun in it */ + if (userns_mkdir(dest, "/dev/net", 0755, 0, 0) < 0) + return log_error_errno(r, "Failed to create /dev/net directory: %m"); + + NULSTR_FOREACH(d, devnodes) { + _cleanup_free_ char *from = NULL, *to = NULL; + struct stat st; + + from = path_join("/dev/", d); + if (!from) + return log_oom(); + + to = path_join(dest, from); + if (!to) + return log_oom(); + + if (stat(from, &st) < 0) { + + if (errno != ENOENT) + return log_error_errno(errno, "Failed to stat %s: %m", from); + + } else if (!S_ISCHR(st.st_mode) && !S_ISBLK(st.st_mode)) + return log_error_errno(SYNTHETIC_ERRNO(EIO), + "%s is not a char or block device, cannot copy.", from); + else { + _cleanup_free_ char *sl = NULL, *prefixed = NULL, *dn = NULL, *t = NULL; + + if (mknod(to, st.st_mode, st.st_rdev) < 0) { + /* Explicitly warn the user when /dev is already populated. */ + if (errno == EEXIST) + log_notice("%s/dev is pre-mounted and pre-populated. If a pre-mounted /dev is provided it needs to be an unpopulated file system.", dest); + if (errno != EPERM) + return log_error_errno(errno, "mknod(%s) failed: %m", to); + + /* Some systems abusively restrict mknod but allow bind mounts. */ + r = touch(to); + if (r < 0) + return log_error_errno(r, "touch (%s) failed: %m", to); + r = mount_nofollow_verbose(LOG_DEBUG, from, to, NULL, MS_BIND, NULL); + if (r < 0) + return log_error_errno(r, "Both mknod and bind mount (%s) failed: %m", to); + } + + r = userns_lchown(to, 0, 0); + if (r < 0) + return log_error_errno(r, "chown() of device node %s failed: %m", to); + + dn = path_join("/dev", S_ISCHR(st.st_mode) ? "char" : "block"); + if (!dn) + return log_oom(); + + r = userns_mkdir(dest, dn, 0755, 0, 0); + if (r < 0) + return log_error_errno(r, "Failed to create '%s': %m", dn); + + if (asprintf(&sl, "%s/%u:%u", dn, major(st.st_rdev), minor(st.st_rdev)) < 0) + return log_oom(); + + prefixed = path_join(dest, sl); + if (!prefixed) + return log_oom(); + + t = path_join("..", d); + if (!t) + return log_oom(); + + if (symlink(t, prefixed) < 0) + log_debug_errno(errno, "Failed to symlink '%s' to '%s': %m", t, prefixed); + } + } + + return r; +} + +static int make_extra_nodes(const char *dest) { + size_t i; + int r; + + BLOCK_WITH_UMASK(0000); + + for (i = 0; i < arg_n_extra_nodes; i++) { + _cleanup_free_ char *path = NULL; + DeviceNode *n = arg_extra_nodes + i; + + path = path_join(dest, n->path); + if (!path) + return log_oom(); + + if (mknod(path, n->mode, S_ISCHR(n->mode) || S_ISBLK(n->mode) ? makedev(n->major, n->minor) : 0) < 0) + return log_error_errno(errno, "Failed to create device node '%s': %m", path); + + r = chmod_and_chown(path, n->mode, n->uid, n->gid); + if (r < 0) + return log_error_errno(r, "Failed to adjust device node ownership of '%s': %m", path); + } + + return 0; +} + +static int setup_pts(const char *dest) { + _cleanup_free_ char *options = NULL; + const char *p; + int r; + +#if HAVE_SELINUX + if (arg_selinux_apifs_context) + (void) asprintf(&options, + "newinstance,ptmxmode=0666,mode=620,gid=" GID_FMT ",context=\"%s\"", + arg_uid_shift + TTY_GID, + arg_selinux_apifs_context); + else +#endif + (void) asprintf(&options, + "newinstance,ptmxmode=0666,mode=620,gid=" GID_FMT, + arg_uid_shift + TTY_GID); + + if (!options) + return log_oom(); + + /* Mount /dev/pts itself */ + p = prefix_roota(dest, "/dev/pts"); + r = RET_NERRNO(mkdir(p, 0755)); + if (r < 0) + return log_error_errno(r, "Failed to create /dev/pts: %m"); + + r = mount_nofollow_verbose(LOG_ERR, "devpts", p, "devpts", MS_NOSUID|MS_NOEXEC, options); + if (r < 0) + return r; + r = userns_lchown(p, 0, 0); + if (r < 0) + return log_error_errno(r, "Failed to chown /dev/pts: %m"); + + /* Create /dev/ptmx symlink */ + p = prefix_roota(dest, "/dev/ptmx"); + if (symlink("pts/ptmx", p) < 0) + return log_error_errno(errno, "Failed to create /dev/ptmx symlink: %m"); + r = userns_lchown(p, 0, 0); + if (r < 0) + return log_error_errno(r, "Failed to chown /dev/ptmx: %m"); + + /* And fix /dev/pts/ptmx ownership */ + p = prefix_roota(dest, "/dev/pts/ptmx"); + r = userns_lchown(p, 0, 0); + if (r < 0) + return log_error_errno(r, "Failed to chown /dev/pts/ptmx: %m"); + + return 0; +} + +static int setup_stdio_as_dev_console(void) { + _cleanup_close_ int terminal = -1; + int r; + + /* We open the TTY in O_NOCTTY mode, so that we do not become controller yet. We'll do that later + * explicitly, if we are configured to. */ + terminal = open_terminal("/dev/console", O_RDWR|O_NOCTTY); + if (terminal < 0) + return log_error_errno(terminal, "Failed to open console: %m"); + + /* Make sure we can continue logging to the original stderr, even if + * stderr points elsewhere now */ + r = log_dup_console(); + if (r < 0) + return log_error_errno(r, "Failed to duplicate stderr: %m"); + + /* invalidates 'terminal' on success and failure */ + r = rearrange_stdio(terminal, terminal, terminal); + TAKE_FD(terminal); + if (r < 0) + return log_error_errno(r, "Failed to move console to stdin/stdout/stderr: %m"); + + return 0; +} + +static int setup_dev_console(const char *console) { + _cleanup_free_ char *p = NULL; + int r; + + /* Create /dev/console symlink */ + r = path_make_relative("/dev", console, &p); + if (r < 0) + return log_error_errno(r, "Failed to create relative path: %m"); + + if (symlink(p, "/dev/console") < 0) + return log_error_errno(errno, "Failed to create /dev/console symlink: %m"); + + return 0; +} + +static int setup_keyring(void) { + key_serial_t keyring; + + /* Allocate a new session keyring for the container. This makes sure the keyring of the session + * systemd-nspawn was invoked from doesn't leak into the container. Note that by default we block + * keyctl() and request_key() anyway via seccomp so doing this operation isn't strictly necessary, + * but in case people explicitly allow-list these system calls let's make sure we don't leak anything + * into the container. */ + + keyring = keyctl(KEYCTL_JOIN_SESSION_KEYRING, 0, 0, 0, 0); + if (keyring == -1) { + if (errno == ENOSYS) + log_debug_errno(errno, "Kernel keyring not supported, ignoring."); + else if (ERRNO_IS_PRIVILEGE(errno)) + log_debug_errno(errno, "Kernel keyring access prohibited, ignoring."); + else + return log_error_errno(errno, "Setting up kernel keyring failed: %m"); + } + + return 0; +} + +static int setup_credentials(const char *root) { + const char *q; + int r; + + if (arg_n_credentials <= 0) + return 0; + + r = userns_mkdir(root, "/run/host", 0755, 0, 0); + if (r < 0) + return log_error_errno(r, "Failed to create /run/host: %m"); + + r = userns_mkdir(root, "/run/host/credentials", 0700, 0, 0); + if (r < 0) + return log_error_errno(r, "Failed to create /run/host/credentials: %m"); + + q = prefix_roota(root, "/run/host/credentials"); + r = mount_nofollow_verbose(LOG_ERR, NULL, q, "ramfs", MS_NOSUID|MS_NOEXEC|MS_NODEV, "mode=0700"); + if (r < 0) + return r; + + for (size_t i = 0; i < arg_n_credentials; i++) { + _cleanup_free_ char *j = NULL; + _cleanup_close_ int fd = -1; + + j = path_join(q, arg_credentials[i].id); + if (!j) + return log_oom(); + + fd = open(j, O_CREAT|O_EXCL|O_WRONLY|O_CLOEXEC|O_NOFOLLOW, 0600); + if (fd < 0) + return log_error_errno(errno, "Failed to create credential file %s: %m", j); + + r = loop_write(fd, arg_credentials[i].data, arg_credentials[i].size, /* do_poll= */ false); + if (r < 0) + return log_error_errno(r, "Failed to write credential to file %s: %m", j); + + if (fchmod(fd, 0400) < 0) + return log_error_errno(errno, "Failed to adjust access mode of %s: %m", j); + + if (arg_userns_mode != USER_NAMESPACE_NO) { + if (fchown(fd, arg_uid_shift, arg_uid_shift) < 0) + return log_error_errno(errno, "Failed to adjust ownership of %s: %m", j); + } + } + + if (chmod(q, 0500) < 0) + return log_error_errno(errno, "Failed to adjust access mode of %s: %m", q); + + r = userns_lchown(q, 0, 0); + if (r < 0) + return r; + + /* Make both mount and superblock read-only now */ + r = mount_nofollow_verbose(LOG_ERR, NULL, q, NULL, MS_REMOUNT|MS_BIND|MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV, NULL); + if (r < 0) + return r; + + return mount_nofollow_verbose(LOG_ERR, NULL, q, NULL, MS_REMOUNT|MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV, "mode=0500"); +} + +static int setup_kmsg(int kmsg_socket) { + _cleanup_(unlink_and_freep) char *from = NULL; + _cleanup_free_ char *fifo = NULL; + _cleanup_close_ int fd = -1; + int r; + + assert(kmsg_socket >= 0); + + BLOCK_WITH_UMASK(0000); + + /* We create the kmsg FIFO as as temporary file in /run, but immediately delete it after bind mounting it to + * /proc/kmsg. While FIFOs on the reading side behave very similar to /proc/kmsg, their writing side behaves + * differently from /dev/kmsg in that writing blocks when nothing is reading. In order to avoid any problems + * with containers deadlocking due to this we simply make /dev/kmsg unavailable to the container. */ + + r = tempfn_random_child("/run", "proc-kmsg", &fifo); + if (r < 0) + return log_error_errno(r, "Failed to generate kmsg path: %m"); + + if (mkfifo(fifo, 0600) < 0) + return log_error_errno(errno, "mkfifo() for /run/kmsg failed: %m"); + + from = TAKE_PTR(fifo); + + r = mount_nofollow_verbose(LOG_ERR, from, "/proc/kmsg", NULL, MS_BIND, NULL); + if (r < 0) + return r; + + fd = open(from, O_RDWR|O_NONBLOCK|O_CLOEXEC); + if (fd < 0) + return log_error_errno(errno, "Failed to open fifo: %m"); + + /* Store away the fd in the socket, so that it stays open as long as we run the child */ + r = send_one_fd(kmsg_socket, fd, 0); + if (r < 0) + return log_error_errno(r, "Failed to send FIFO fd: %m"); + + return 0; +} + +struct ExposeArgs { + union in_addr_union address4; + union in_addr_union address6; + struct FirewallContext *fw_ctx; +}; + +static int on_address_change(sd_netlink *rtnl, sd_netlink_message *m, void *userdata) { + struct ExposeArgs *args = ASSERT_PTR(userdata); + + assert(rtnl); + assert(m); + + (void) expose_port_execute(rtnl, &args->fw_ctx, arg_expose_ports, AF_INET, &args->address4); + (void) expose_port_execute(rtnl, &args->fw_ctx, arg_expose_ports, AF_INET6, &args->address6); + return 0; +} + +static int setup_hostname(void) { + int r; + + if ((arg_clone_ns_flags & CLONE_NEWUTS) == 0) + return 0; + + r = sethostname_idempotent(arg_hostname ?: arg_machine); + if (r < 0) + return log_error_errno(r, "Failed to set hostname: %m"); + + return 0; +} + +static int setup_journal(const char *directory) { + _cleanup_free_ char *d = NULL; + const char *p, *q; + sd_id128_t this_id; + bool try; + int r; + + /* Don't link journals in ephemeral mode */ + if (arg_ephemeral) + return 0; + + if (arg_link_journal == LINK_NO) + return 0; + + try = arg_link_journal_try || arg_link_journal == LINK_AUTO; + + r = sd_id128_get_machine(&this_id); + if (r < 0) + return log_error_errno(r, "Failed to retrieve machine ID: %m"); + + if (sd_id128_equal(arg_uuid, this_id)) { + log_full(try ? LOG_WARNING : LOG_ERR, + "Host and machine ids are equal (%s): refusing to link journals", SD_ID128_TO_STRING(arg_uuid)); + if (try) + return 0; + return -EEXIST; + } + + FOREACH_STRING(dirname, "/var", "/var/log", "/var/log/journal") { + r = userns_mkdir(directory, dirname, 0755, 0, 0); + if (r < 0) { + bool ignore = r == -EROFS && try; + log_full_errno(ignore ? LOG_DEBUG : LOG_ERR, r, + "Failed to create %s%s: %m", dirname, ignore ? ", ignoring" : ""); + return ignore ? 0 : r; + } + } + + p = strjoina("/var/log/journal/", SD_ID128_TO_STRING(arg_uuid)); + q = prefix_roota(directory, p); + + if (path_is_mount_point(p, NULL, 0) > 0) { + if (try) + return 0; + + return log_error_errno(SYNTHETIC_ERRNO(EEXIST), + "%s: already a mount point, refusing to use for journal", p); + } + + if (path_is_mount_point(q, NULL, 0) > 0) { + if (try) + return 0; + + return log_error_errno(SYNTHETIC_ERRNO(EEXIST), + "%s: already a mount point, refusing to use for journal", q); + } + + r = readlink_and_make_absolute(p, &d); + if (r >= 0) { + if (IN_SET(arg_link_journal, LINK_GUEST, LINK_AUTO) && + path_equal(d, q)) { + + r = userns_mkdir(directory, p, 0755, 0, 0); + if (r < 0) + log_warning_errno(r, "Failed to create directory %s: %m", q); + return 0; + } + + if (unlink(p) < 0) + return log_error_errno(errno, "Failed to remove symlink %s: %m", p); + } else if (r == -EINVAL) { + + if (arg_link_journal == LINK_GUEST && + rmdir(p) < 0) { + + if (errno == ENOTDIR) { + log_error("%s already exists and is neither a symlink nor a directory", p); + return r; + } else + return log_error_errno(errno, "Failed to remove %s: %m", p); + } + } else if (r != -ENOENT) + return log_error_errno(r, "readlink(%s) failed: %m", p); + + if (arg_link_journal == LINK_GUEST) { + + if (symlink(q, p) < 0) { + if (try) { + log_debug_errno(errno, "Failed to symlink %s to %s, skipping journal setup: %m", q, p); + return 0; + } else + return log_error_errno(errno, "Failed to symlink %s to %s: %m", q, p); + } + + r = userns_mkdir(directory, p, 0755, 0, 0); + if (r < 0) + log_warning_errno(r, "Failed to create directory %s: %m", q); + return 0; + } + + if (arg_link_journal == LINK_HOST) { + /* don't create parents here — if the host doesn't have + * permanent journal set up, don't force it here */ + + r = RET_NERRNO(mkdir(p, 0755)); + if (r < 0 && r != -EEXIST) { + if (try) { + log_debug_errno(r, "Failed to create %s, skipping journal setup: %m", p); + return 0; + } else + return log_error_errno(r, "Failed to create %s: %m", p); + } + + } else if (access(p, F_OK) < 0) + return 0; + + if (dir_is_empty(q, /* ignore_hidden_or_backup= */ false) == 0) + log_warning("%s is not empty, proceeding anyway.", q); + + r = userns_mkdir(directory, p, 0755, 0, 0); + if (r < 0) + return log_error_errno(r, "Failed to create %s: %m", q); + + r = mount_nofollow_verbose(LOG_DEBUG, p, q, NULL, MS_BIND, NULL); + if (r < 0) + return log_error_errno(errno, "Failed to bind mount journal from host into guest: %m"); + + return 0; +} + +static int drop_capabilities(uid_t uid) { + CapabilityQuintet q; + + /* Let's initialize all five capability sets to something valid. If the quintet was configured via + * OCI use that, but fill in missing bits. If it wasn't then derive the quintet in full from + * arg_caps_retain. */ + + if (capability_quintet_is_set(&arg_full_capabilities)) { + q = arg_full_capabilities; + + if (q.bounding == UINT64_MAX) + q.bounding = uid == 0 ? arg_caps_retain : 0; + + if (q.effective == UINT64_MAX) + q.effective = uid == 0 ? q.bounding : 0; + + if (q.inheritable == UINT64_MAX) + q.inheritable = uid == 0 ? q.bounding : arg_caps_ambient; + + if (q.permitted == UINT64_MAX) + q.permitted = uid == 0 ? q.bounding : arg_caps_ambient; + + if (q.ambient == UINT64_MAX && ambient_capabilities_supported()) + q.ambient = arg_caps_ambient; + + if (capability_quintet_mangle(&q)) + return log_error_errno(SYNTHETIC_ERRNO(EPERM), "Cannot set capabilities that are not in the current bounding set."); + + } else { + q = (CapabilityQuintet) { + .bounding = arg_caps_retain, + .effective = uid == 0 ? arg_caps_retain : 0, + .inheritable = uid == 0 ? arg_caps_retain : arg_caps_ambient, + .permitted = uid == 0 ? arg_caps_retain : arg_caps_ambient, + .ambient = ambient_capabilities_supported() ? arg_caps_ambient : UINT64_MAX, + }; + + /* If we're not using OCI, proceed with mangled capabilities (so we don't error out) + * in order to maintain the same behavior as systemd < 242. */ + if (capability_quintet_mangle(&q)) + log_full(arg_quiet ? LOG_DEBUG : LOG_WARNING, + "Some capabilities will not be set because they are not in the current bounding set."); + + } + + return capability_quintet_enforce(&q); +} + +static int reset_audit_loginuid(void) { + _cleanup_free_ char *p = NULL; + int r; + + if ((arg_clone_ns_flags & CLONE_NEWPID) == 0) + return 0; + + r = read_one_line_file("/proc/self/loginuid", &p); + if (r == -ENOENT) + return 0; + if (r < 0) + return log_error_errno(r, "Failed to read /proc/self/loginuid: %m"); + + /* Already reset? */ + if (streq(p, "4294967295")) + return 0; + + r = write_string_file("/proc/self/loginuid", "4294967295", WRITE_STRING_FILE_DISABLE_BUFFER); + if (r < 0) { + log_error_errno(r, + "Failed to reset audit login UID. This probably means that your kernel is too\n" + "old and you have audit enabled. Note that the auditing subsystem is known to\n" + "be incompatible with containers on old kernels. Please make sure to upgrade\n" + "your kernel or to off auditing with 'audit=0' on the kernel command line before\n" + "using systemd-nspawn. Sleeping for 5s... (%m)"); + + sleep(5); + } + + return 0; +} + +static int setup_propagate(const char *root) { + const char *p, *q; + int r; + + (void) mkdir_p("/run/systemd/nspawn/", 0755); + (void) mkdir_p("/run/systemd/nspawn/propagate", 0600); + p = strjoina("/run/systemd/nspawn/propagate/", arg_machine); + (void) mkdir_p(p, 0600); + + r = userns_mkdir(root, "/run/host", 0755, 0, 0); + if (r < 0) + return log_error_errno(r, "Failed to create /run/host: %m"); + + r = userns_mkdir(root, "/run/host/incoming", 0600, 0, 0); + if (r < 0) + return log_error_errno(r, "Failed to create /run/host/incoming: %m"); + + q = prefix_roota(root, "/run/host/incoming"); + r = mount_nofollow_verbose(LOG_ERR, p, q, NULL, MS_BIND, NULL); + if (r < 0) + return r; + + r = mount_nofollow_verbose(LOG_ERR, NULL, q, NULL, MS_BIND|MS_REMOUNT|MS_RDONLY, NULL); + if (r < 0) + return r; + + /* machined will MS_MOVE into that directory, and that's only supported for non-shared mounts. */ + return mount_nofollow_verbose(LOG_ERR, NULL, q, NULL, MS_SLAVE, NULL); +} + +static int setup_machine_id(const char *directory) { + const char *etc_machine_id; + sd_id128_t id; + int r; + + /* If the UUID in the container is already set, then that's what counts, and we use. If it isn't set, and the + * caller passed --uuid=, then we'll pass it in the $container_uuid env var to PID 1 of the container. The + * assumption is that PID 1 will then write it to /etc/machine-id to make it persistent. If --uuid= is not + * passed we generate a random UUID, and pass it via $container_uuid. In effect this means that /etc/machine-id + * in the container and our idea of the container UUID will always be in sync (at least if PID 1 in the + * container behaves nicely). */ + + etc_machine_id = prefix_roota(directory, "/etc/machine-id"); + + r = id128_read(etc_machine_id, ID128_FORMAT_PLAIN, &id); + if (r < 0) { + if (!IN_SET(r, -ENOENT, -ENOMEDIUM, -ENOPKG)) /* If the file is missing, empty, or uninitialized, we don't mind */ + return log_error_errno(r, "Failed to read machine ID from container image: %m"); + + if (sd_id128_is_null(arg_uuid)) { + r = sd_id128_randomize(&arg_uuid); + if (r < 0) + return log_error_errno(r, "Failed to acquire randomized machine UUID: %m"); + } + } else { + if (sd_id128_is_null(id)) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), + "Machine ID in container image is zero, refusing."); + + arg_uuid = id; + } + + return 0; +} + +static int recursive_chown(const char *directory, uid_t shift, uid_t range) { + int r; + + assert(directory); + + if (arg_userns_mode == USER_NAMESPACE_NO || arg_userns_ownership != USER_NAMESPACE_OWNERSHIP_CHOWN) + return 0; + + r = path_patch_uid(directory, arg_uid_shift, arg_uid_range); + if (r == -EOPNOTSUPP) + return log_error_errno(r, "Automatic UID/GID adjusting is only supported for UID/GID ranges starting at multiples of 2^16 with a range of 2^16."); + if (r == -EBADE) + return log_error_errno(r, "Upper 16 bits of root directory UID and GID do not match."); + if (r < 0) + return log_error_errno(r, "Failed to adjust UID/GID shift of OS tree: %m"); + if (r == 0) + log_debug("Root directory of image is already owned by the right UID/GID range, skipping recursive chown operation."); + else + log_debug("Patched directory tree to match UID/GID range."); + + return r; +} + +/* + * Return values: + * < 0 : wait_for_terminate() failed to get the state of the + * container, the container was terminated by a signal, or + * failed for an unknown reason. No change is made to the + * container argument. + * > 0 : The program executed in the container terminated with an + * error. The exit code of the program executed in the + * container is returned. The container argument has been set + * to CONTAINER_TERMINATED. + * 0 : The container is being rebooted, has been shut down or exited + * successfully. The container argument has been set to either + * CONTAINER_TERMINATED or CONTAINER_REBOOTED. + * + * That is, success is indicated by a return value of zero, and an + * error is indicated by a non-zero value. + */ +static int wait_for_container(pid_t pid, ContainerStatus *container) { + siginfo_t status; + int r; + + r = wait_for_terminate(pid, &status); + if (r < 0) + return log_warning_errno(r, "Failed to wait for container: %m"); + + switch (status.si_code) { + + case CLD_EXITED: + if (status.si_status == 0) + log_full(arg_quiet ? LOG_DEBUG : LOG_INFO, "Container %s exited successfully.", arg_machine); + else + log_full(arg_quiet ? LOG_DEBUG : LOG_INFO, "Container %s failed with error code %i.", arg_machine, status.si_status); + + *container = CONTAINER_TERMINATED; + return status.si_status; + + case CLD_KILLED: + if (status.si_status == SIGINT) { + log_full(arg_quiet ? LOG_DEBUG : LOG_INFO, "Container %s has been shut down.", arg_machine); + *container = CONTAINER_TERMINATED; + return 0; + + } else if (status.si_status == SIGHUP) { + log_full(arg_quiet ? LOG_DEBUG : LOG_INFO, "Container %s is being rebooted.", arg_machine); + *container = CONTAINER_REBOOTED; + return 0; + } + + _fallthrough_; + case CLD_DUMPED: + return log_error_errno(SYNTHETIC_ERRNO(EIO), + "Container %s terminated by signal %s.", arg_machine, signal_to_string(status.si_status)); + + default: + return log_error_errno(SYNTHETIC_ERRNO(EIO), + "Container %s failed due to unknown reason.", arg_machine); + } +} + +static int on_orderly_shutdown(sd_event_source *s, const struct signalfd_siginfo *si, void *userdata) { + pid_t pid; + + pid = PTR_TO_PID(userdata); + if (pid > 0) { + if (kill(pid, arg_kill_signal) >= 0) { + log_info("Trying to halt container. Send SIGTERM again to trigger immediate termination."); + sd_event_source_set_userdata(s, NULL); + return 0; + } + } + + sd_event_exit(sd_event_source_get_event(s), 0); + return 0; +} + +static int on_sigchld(sd_event_source *s, const struct signalfd_siginfo *ssi, void *userdata) { + pid_t pid; + + assert(s); + assert(ssi); + + pid = PTR_TO_PID(userdata); + + for (;;) { + siginfo_t si = {}; + + if (waitid(P_ALL, 0, &si, WNOHANG|WNOWAIT|WEXITED) < 0) + return log_error_errno(errno, "Failed to waitid(): %m"); + if (si.si_pid == 0) /* No pending children. */ + break; + if (si.si_pid == pid) { + /* The main process we care for has exited. Return from + * signal handler but leave the zombie. */ + sd_event_exit(sd_event_source_get_event(s), 0); + break; + } + + /* Reap all other children. */ + (void) waitid(P_PID, si.si_pid, &si, WNOHANG|WEXITED); + } + + return 0; +} + +static int on_request_stop(sd_bus_message *m, void *userdata, sd_bus_error *error) { + pid_t pid; + + assert(m); + + pid = PTR_TO_PID(userdata); + + if (arg_kill_signal > 0) { + log_info("Container termination requested. Attempting to halt container."); + (void) kill(pid, arg_kill_signal); + } else { + log_info("Container termination requested. Exiting."); + sd_event_exit(sd_bus_get_event(sd_bus_message_get_bus(m)), 0); + } + + return 0; +} + +static int determine_names(void) { + int r; + + if (arg_template && !arg_directory && arg_machine) { + + /* If --template= was specified then we should not + * search for a machine, but instead create a new one + * in /var/lib/machine. */ + + arg_directory = path_join("/var/lib/machines", arg_machine); + if (!arg_directory) + return log_oom(); + } + + if (!arg_image && !arg_directory) { + if (arg_machine) { + _cleanup_(image_unrefp) Image *i = NULL; + + r = image_find(IMAGE_MACHINE, arg_machine, NULL, &i); + if (r == -ENOENT) + return log_error_errno(r, "No image for machine '%s'.", arg_machine); + if (r < 0) + return log_error_errno(r, "Failed to find image for machine '%s': %m", arg_machine); + + if (IN_SET(i->type, IMAGE_RAW, IMAGE_BLOCK)) + r = free_and_strdup(&arg_image, i->path); + else + r = free_and_strdup(&arg_directory, i->path); + if (r < 0) + return log_oom(); + + if (!arg_ephemeral) + arg_read_only = arg_read_only || i->read_only; + } else { + r = safe_getcwd(&arg_directory); + if (r < 0) + return log_error_errno(r, "Failed to determine current directory: %m"); + } + + if (!arg_directory && !arg_image) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to determine path, please use -D or -i."); + } + + if (!arg_machine) { + if (arg_directory && path_equal(arg_directory, "/")) + arg_machine = gethostname_malloc(); + else if (arg_image) { + char *e; + + arg_machine = strdup(basename(arg_image)); + + /* Truncate suffix if there is one */ + e = endswith(arg_machine, ".raw"); + if (e) + *e = 0; + } else + arg_machine = strdup(basename(arg_directory)); + if (!arg_machine) + return log_oom(); + + hostname_cleanup(arg_machine); + if (!hostname_is_valid(arg_machine, 0)) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to determine machine name automatically, please use -M."); + + /* Copy the machine name before the random suffix is added below, otherwise we won't be able + * to match fixed config file names. */ + arg_settings_filename = strjoin(arg_machine, ".nspawn"); + if (!arg_settings_filename) + return log_oom(); + + /* Add a random suffix when this is an ephemeral machine, so that we can run many + * instances at once without manually having to specify -M each time. */ + if (arg_ephemeral) + if (strextendf(&arg_machine, "-%016" PRIx64, random_u64()) < 0) + return log_oom(); + } else { + arg_settings_filename = strjoin(arg_machine, ".nspawn"); + if (!arg_settings_filename) + return log_oom(); + } + + return 0; +} + +static int chase_symlinks_and_update(char **p, unsigned flags) { + char *chased; + int r; + + assert(p); + + if (!*p) + return 0; + + r = chase_symlinks(*p, NULL, flags, &chased, NULL); + if (r < 0) + return log_error_errno(r, "Failed to resolve path %s: %m", *p); + + return free_and_replace(*p, chased); +} + +static int determine_uid_shift(const char *directory) { + + if (arg_userns_mode == USER_NAMESPACE_NO) { + arg_uid_shift = 0; + return 0; + } + + if (arg_uid_shift == UID_INVALID) { + struct stat st; + + /* Read the UID shift off the image. Maybe we can reuse this to avoid chowning. */ + + if (stat(directory, &st) < 0) + return log_error_errno(errno, "Failed to determine UID base of %s: %m", directory); + + arg_uid_shift = st.st_uid & UINT32_C(0xffff0000); + + if (arg_uid_shift != (st.st_gid & UINT32_C(0xffff0000))) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), + "UID and GID base of %s don't match.", directory); + + arg_uid_range = UINT32_C(0x10000); + + if (arg_uid_shift != 0) { + /* If the image is shifted already, then we'll fall back to classic chowning, for + * compatibility (and simplicity), or refuse if mapping is explicitly requested. */ + + if (arg_userns_ownership == USER_NAMESPACE_OWNERSHIP_AUTO) { + log_debug("UID base of %s is non-zero, not using UID mapping.", directory); + arg_userns_ownership = USER_NAMESPACE_OWNERSHIP_CHOWN; + } else if (arg_userns_ownership == USER_NAMESPACE_OWNERSHIP_MAP) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), + "UID base of %s is not zero, UID mapping not supported.", directory); + } + } + + if (!userns_shift_range_valid(arg_uid_shift, arg_uid_range)) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "UID base too high for UID range."); + + return 0; +} + +static unsigned long effective_clone_ns_flags(void) { + unsigned long flags = arg_clone_ns_flags; + + if (arg_private_network) + flags |= CLONE_NEWNET; + if (arg_use_cgns) + flags |= CLONE_NEWCGROUP; + if (arg_userns_mode != USER_NAMESPACE_NO) + flags |= CLONE_NEWUSER; + + return flags; +} + +static int patch_sysctl(void) { + + /* This table is inspired by runc's sysctl() function */ + static const struct { + const char *key; + bool prefix; + unsigned long clone_flags; + } safe_sysctl[] = { + { "kernel.hostname", false, CLONE_NEWUTS }, + { "kernel.domainname", false, CLONE_NEWUTS }, + { "kernel.msgmax", false, CLONE_NEWIPC }, + { "kernel.msgmnb", false, CLONE_NEWIPC }, + { "kernel.msgmni", false, CLONE_NEWIPC }, + { "kernel.sem", false, CLONE_NEWIPC }, + { "kernel.shmall", false, CLONE_NEWIPC }, + { "kernel.shmmax", false, CLONE_NEWIPC }, + { "kernel.shmmni", false, CLONE_NEWIPC }, + { "fs.mqueue.", true, CLONE_NEWIPC }, + { "net.", true, CLONE_NEWNET }, + }; + + unsigned long flags; + int r; + + flags = effective_clone_ns_flags(); + + STRV_FOREACH_PAIR(k, v, arg_sysctl) { + bool good = false; + size_t i; + + for (i = 0; i < ELEMENTSOF(safe_sysctl); i++) { + + if (!FLAGS_SET(flags, safe_sysctl[i].clone_flags)) + continue; + + if (safe_sysctl[i].prefix) + good = startswith(*k, safe_sysctl[i].key); + else + good = streq(*k, safe_sysctl[i].key); + + if (good) + break; + } + + if (!good) + return log_error_errno(SYNTHETIC_ERRNO(EPERM), "Refusing to write to sysctl '%s', as it is not safe in the selected namespaces.", *k); + + r = sysctl_write(*k, *v); + if (r < 0) + return log_error_errno(r, "Failed to write sysctl '%s': %m", *k); + } + + return 0; +} + +static int inner_child( + Barrier *barrier, + const char *directory, + bool secondary, + int kmsg_socket, + int rtnl_socket, + int master_pty_socket, + FDSet *fds, + char **os_release_pairs) { + + _cleanup_free_ char *home = NULL; + size_t n_env = 1; + char *envp[] = { + (char*) "PATH=" DEFAULT_PATH_COMPAT, + NULL, /* container */ + NULL, /* TERM */ + NULL, /* HOME */ + NULL, /* USER */ + NULL, /* LOGNAME */ + NULL, /* container_uuid */ + NULL, /* LISTEN_FDS */ + NULL, /* LISTEN_PID */ + NULL, /* NOTIFY_SOCKET */ + NULL, /* CREDENTIALS_DIRECTORY */ + NULL, /* LANG */ + NULL + }; + const char *exec_target; + _cleanup_strv_free_ char **env_use = NULL; + int r, which_failed; + + /* This is the "inner" child process, i.e. the one forked off by the "outer" child process, which is the one + * the container manager itself forked off. At the time of clone() it gained its own CLONE_NEWNS, CLONE_NEWPID, + * CLONE_NEWUTS, CLONE_NEWIPC, CLONE_NEWUSER namespaces. Note that it has its own CLONE_NEWNS namespace, + * separate from the CLONE_NEWNS created for the "outer" child, and also separate from the host's CLONE_NEWNS + * namespace. The reason for having two levels of CLONE_NEWNS namespaces is that the "inner" one is owned by + * the CLONE_NEWUSER namespace of the container, while the "outer" one is owned by the host's CLONE_NEWUSER + * namespace. + * + * Note at this point we have no CLONE_NEWNET namespace yet. We'll acquire that one later through + * unshare(). See below. */ + + assert(barrier); + assert(directory); + assert(kmsg_socket >= 0); + + log_debug("Inner child is initializing."); + + if (arg_userns_mode != USER_NAMESPACE_NO) { + /* Tell the parent, that it now can write the UID map. */ + (void) barrier_place(barrier); /* #1 */ + + /* Wait until the parent wrote the UID map */ + if (!barrier_place_and_sync(barrier)) /* #2 */ + return log_error_errno(SYNTHETIC_ERRNO(ESRCH), "Parent died too early"); + + /* Become the new root user inside our namespace */ + r = reset_uid_gid(); + if (r < 0) + return log_error_errno(r, "Couldn't become new root: %m"); + + /* Creating a new user namespace means all MS_SHARED mounts become MS_SLAVE. Let's put them + * back to MS_SHARED here, since that's what we want as defaults. (This will not reconnect + * propagation, but simply create new peer groups for all our mounts). */ + r = mount_follow_verbose(LOG_ERR, NULL, "/", NULL, MS_SHARED|MS_REC, NULL); + if (r < 0) + return r; + } + + r = mount_all(NULL, + arg_mount_settings | MOUNT_IN_USERNS, + arg_uid_shift, + arg_selinux_apifs_context); + if (r < 0) + return r; + + if (!arg_network_namespace_path && arg_private_network) { + r = unshare(CLONE_NEWNET); + if (r < 0) + return log_error_errno(errno, "Failed to unshare network namespace: %m"); + + /* Tell the parent that it can setup network interfaces. */ + (void) barrier_place(barrier); /* #3 */ + } + + r = mount_sysfs(NULL, arg_mount_settings); + if (r < 0) + return r; + + /* Wait until we are cgroup-ified, so that we + * can mount the right cgroup path writable */ + if (!barrier_place_and_sync(barrier)) /* #4 */ + return log_error_errno(SYNTHETIC_ERRNO(ESRCH), + "Parent died too early"); + + if (arg_use_cgns) { + r = unshare(CLONE_NEWCGROUP); + if (r < 0) + return log_error_errno(errno, "Failed to unshare cgroup namespace: %m"); + r = mount_cgroups( + "", + arg_unified_cgroup_hierarchy, + arg_userns_mode != USER_NAMESPACE_NO, + arg_uid_shift, + arg_uid_range, + arg_selinux_apifs_context, + true); + } else + r = mount_systemd_cgroup_writable("", arg_unified_cgroup_hierarchy); + if (r < 0) + return r; + + r = setup_boot_id(); + if (r < 0) + return r; + + r = setup_kmsg(kmsg_socket); + if (r < 0) + return r; + kmsg_socket = safe_close(kmsg_socket); + + r = mount_custom( + "/", + arg_custom_mounts, + arg_n_custom_mounts, + 0, + 0, + arg_selinux_apifs_context, + MOUNT_NON_ROOT_ONLY | MOUNT_IN_USERNS); + if (r < 0) + return r; + + if (setsid() < 0) + return log_error_errno(errno, "setsid() failed: %m"); + + if (arg_private_network) + (void) loopback_setup(); + + if (arg_expose_ports) { + r = expose_port_send_rtnl(rtnl_socket); + if (r < 0) + return r; + rtnl_socket = safe_close(rtnl_socket); + } + + if (arg_console_mode != CONSOLE_PIPE) { + _cleanup_close_ int master = -1; + _cleanup_free_ char *console = NULL; + + /* Allocate a pty and make it available as /dev/console. */ + master = openpt_allocate(O_RDWR|O_NONBLOCK, &console); + if (master < 0) + return log_error_errno(master, "Failed to allocate a pty: %m"); + + r = setup_dev_console(console); + if (r < 0) + return log_error_errno(r, "Failed to set up /dev/console: %m"); + + r = send_one_fd(master_pty_socket, master, 0); + if (r < 0) + return log_error_errno(r, "Failed to send master fd: %m"); + master_pty_socket = safe_close(master_pty_socket); + + r = setup_stdio_as_dev_console(); + if (r < 0) + return r; + } + + r = patch_sysctl(); + if (r < 0) + return r; + + if (arg_oom_score_adjust_set) { + r = set_oom_score_adjust(arg_oom_score_adjust); + if (r < 0) + return log_error_errno(r, "Failed to adjust OOM score: %m"); + } + + if (arg_cpu_set.set) + if (sched_setaffinity(0, arg_cpu_set.allocated, arg_cpu_set.set) < 0) + return log_error_errno(errno, "Failed to set CPU affinity: %m"); + + (void) setup_hostname(); + + if (arg_personality != PERSONALITY_INVALID) { + r = safe_personality(arg_personality); + if (r < 0) + return log_error_errno(r, "personality() failed: %m"); + } else if (secondary) { + r = safe_personality(PER_LINUX32); + if (r < 0) + return log_error_errno(r, "personality() failed: %m"); + } + + r = setrlimit_closest_all((const struct rlimit *const*) arg_rlimit, &which_failed); + if (r < 0) + return log_error_errno(r, "Failed to apply resource limit RLIMIT_%s: %m", rlimit_to_string(which_failed)); + +#if HAVE_SECCOMP + if (arg_seccomp) { + + if (is_seccomp_available()) { + + r = seccomp_load(arg_seccomp); + if (ERRNO_IS_SECCOMP_FATAL(r)) + return log_error_errno(r, "Failed to install seccomp filter: %m"); + if (r < 0) + log_debug_errno(r, "Failed to install seccomp filter: %m"); + } + } else +#endif + { + r = setup_seccomp(arg_caps_retain, arg_syscall_allow_list, arg_syscall_deny_list); + if (r < 0) + return r; + } + + if (arg_suppress_sync) { +#if HAVE_SECCOMP + r = seccomp_suppress_sync(); + if (r < 0) + log_debug_errno(r, "Failed to install sync() suppression seccomp filter, ignoring: %m"); +#else + log_debug("systemd is built without SECCOMP support. Ignoring --suppress-sync= command line option and SuppressSync= setting."); +#endif + } + +#if HAVE_SELINUX + if (arg_selinux_context) + if (setexeccon(arg_selinux_context) < 0) + return log_error_errno(errno, "setexeccon(\"%s\") failed: %m", arg_selinux_context); +#endif + + /* Make sure we keep the caps across the uid/gid dropping, so that we can retain some selected caps + * if we need to later on. */ + if (prctl(PR_SET_KEEPCAPS, 1) < 0) + return log_error_errno(errno, "Failed to set PR_SET_KEEPCAPS: %m"); + + if (uid_is_valid(arg_uid) || gid_is_valid(arg_gid)) + r = change_uid_gid_raw(arg_uid, arg_gid, arg_supplementary_gids, arg_n_supplementary_gids, arg_console_mode != CONSOLE_PIPE); + else + r = change_uid_gid(arg_user, arg_console_mode != CONSOLE_PIPE, &home); + if (r < 0) + return r; + + r = drop_capabilities(getuid()); + if (r < 0) + return log_error_errno(r, "Dropping capabilities failed: %m"); + + if (arg_no_new_privileges) + if (prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0) < 0) + return log_error_errno(errno, "Failed to disable new privileges: %m"); + + /* LXC sets container=lxc, so follow the scheme here */ + envp[n_env++] = strjoina("container=", arg_container_service_name); + + envp[n_env] = strv_find_prefix(environ, "TERM="); + if (envp[n_env]) + n_env++; + + if (home || !uid_is_valid(arg_uid) || arg_uid == 0) + if (asprintf(envp + n_env++, "HOME=%s", home ?: "/root") < 0) + return log_oom(); + + if (arg_user || !uid_is_valid(arg_uid) || arg_uid == 0) + if (asprintf(envp + n_env++, "USER=%s", arg_user ?: "root") < 0 || + asprintf(envp + n_env++, "LOGNAME=%s", arg_user ? arg_user : "root") < 0) + return log_oom(); + + assert(!sd_id128_is_null(arg_uuid)); + + if (asprintf(envp + n_env++, "container_uuid=%s", SD_ID128_TO_UUID_STRING(arg_uuid)) < 0) + return log_oom(); + + if (fdset_size(fds) > 0) { + r = fdset_cloexec(fds, false); + if (r < 0) + return log_error_errno(r, "Failed to unset O_CLOEXEC for file descriptors."); + + if ((asprintf(envp + n_env++, "LISTEN_FDS=%u", fdset_size(fds)) < 0) || + (asprintf(envp + n_env++, "LISTEN_PID=1") < 0)) + return log_oom(); + } + if (asprintf(envp + n_env++, "NOTIFY_SOCKET=%s", NSPAWN_NOTIFY_SOCKET_PATH) < 0) + return log_oom(); + + if (arg_n_credentials > 0) { + envp[n_env] = strdup("CREDENTIALS_DIRECTORY=/run/host/credentials"); + if (!envp[n_env]) + return log_oom(); + n_env++; + } + + if (arg_start_mode != START_BOOT) { + envp[n_env] = strdup("LANG=" SYSTEMD_NSPAWN_LOCALE); + if (!envp[n_env]) + return log_oom(); + n_env++; + } + + env_use = strv_env_merge(envp, os_release_pairs, arg_setenv); + if (!env_use) + return log_oom(); + + /* Let the parent know that we are ready and + * wait until the parent is ready with the + * setup, too... */ + if (!barrier_place_and_sync(barrier)) /* #5 */ + return log_error_errno(SYNTHETIC_ERRNO(ESRCH), "Parent died too early"); + + if (arg_chdir) + if (chdir(arg_chdir) < 0) + return log_error_errno(errno, "Failed to change to specified working directory %s: %m", arg_chdir); + + if (arg_start_mode == START_PID2) { + r = stub_pid1(arg_uuid); + if (r < 0) + return r; + } + + if (arg_console_mode != CONSOLE_PIPE) { + /* So far our pty wasn't controlled by any process. Finally, it's time to change that, if we + * are configured for that. Acquire it as controlling tty. */ + if (ioctl(STDIN_FILENO, TIOCSCTTY) < 0) + return log_error_errno(errno, "Failed to acquire controlling TTY: %m"); + } + + log_debug("Inner child completed, invoking payload."); + + /* Now, explicitly close the log, so that we then can close all remaining fds. Closing the log explicitly first + * has the benefit that the logging subsystem knows about it, and is thus ready to be reopened should we need + * it again. Note that the other fds closed here are at least the locking and barrier fds. */ + log_close(); + log_set_open_when_needed(true); + log_settle_target(); + + (void) fdset_close_others(fds); + + if (arg_start_mode == START_BOOT) { + char **a; + size_t m; + + /* Automatically search for the init system */ + + m = strv_length(arg_parameters); + a = newa(char*, m + 2); + memcpy_safe(a + 1, arg_parameters, m * sizeof(char*)); + a[1 + m] = NULL; + + FOREACH_STRING(init, + "/usr/lib/systemd/systemd", + "/lib/systemd/systemd", + "/sbin/init") { + a[0] = (char*) init; + execve(a[0], a, env_use); + } + + exec_target = "/usr/lib/systemd/systemd, /lib/systemd/systemd, /sbin/init"; + } else if (!strv_isempty(arg_parameters)) { + const char *dollar_path; + + exec_target = arg_parameters[0]; + + /* Use the user supplied search $PATH if there is one, or DEFAULT_PATH_COMPAT if not to search the + * binary. */ + dollar_path = strv_env_get(env_use, "PATH"); + if (dollar_path) { + if (setenv("PATH", dollar_path, 1) < 0) + return log_error_errno(errno, "Failed to update $PATH: %m"); + } + + execvpe(arg_parameters[0], arg_parameters, env_use); + } else { + if (!arg_chdir) + /* If we cannot change the directory, we'll end up in /, that is expected. */ + (void) chdir(home ?: "/root"); + + execle(DEFAULT_USER_SHELL, "-" DEFAULT_USER_SHELL_NAME, NULL, env_use); + if (!streq(DEFAULT_USER_SHELL, "/bin/bash")) + execle("/bin/bash", "-bash", NULL, env_use); + if (!streq(DEFAULT_USER_SHELL, "/bin/sh")) + execle("/bin/sh", "-sh", NULL, env_use); + + exec_target = DEFAULT_USER_SHELL ", /bin/bash, /bin/sh"; + } + + return log_error_errno(errno, "execv(%s) failed: %m", exec_target); +} + +static int setup_notify_child(void) { + _cleanup_close_ int fd = -1; + static const union sockaddr_union sa = { + .un.sun_family = AF_UNIX, + .un.sun_path = NSPAWN_NOTIFY_SOCKET_PATH, + }; + int r; + + fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0); + if (fd < 0) + return log_error_errno(errno, "Failed to allocate notification socket: %m"); + + (void) mkdir_parents(NSPAWN_NOTIFY_SOCKET_PATH, 0755); + (void) sockaddr_un_unlink(&sa.un); + + r = bind(fd, &sa.sa, SOCKADDR_UN_LEN(sa.un)); + if (r < 0) + return log_error_errno(errno, "bind(" NSPAWN_NOTIFY_SOCKET_PATH ") failed: %m"); + + r = userns_lchown(NSPAWN_NOTIFY_SOCKET_PATH, 0, 0); + if (r < 0) + return log_error_errno(r, "Failed to chown " NSPAWN_NOTIFY_SOCKET_PATH ": %m"); + + r = setsockopt_int(fd, SOL_SOCKET, SO_PASSCRED, true); + if (r < 0) + return log_error_errno(r, "SO_PASSCRED failed: %m"); + + return TAKE_FD(fd); +} + +static int outer_child( + Barrier *barrier, + const char *directory, + DissectedImage *dissected_image, + bool secondary, + int pid_socket, + int uuid_socket, + int notify_socket, + int kmsg_socket, + int rtnl_socket, + int uid_shift_socket, + int master_pty_socket, + int unified_cgroup_hierarchy_socket, + FDSet *fds, + int netns_fd) { + + _cleanup_(bind_user_context_freep) BindUserContext *bind_user_context = NULL; + _cleanup_strv_free_ char **os_release_pairs = NULL; + _cleanup_close_ int fd = -1; + bool idmap = false; + const char *p; + pid_t pid; + ssize_t l; + int r; + + /* This is the "outer" child process, i.e the one forked off by the container manager itself. It + * already has its own CLONE_NEWNS namespace (which was created by the clone()). It still lives in + * the host's CLONE_NEWPID, CLONE_NEWUTS, CLONE_NEWIPC, CLONE_NEWUSER and CLONE_NEWNET + * namespaces. After it completed a number of initializations a second child (the "inner" one) is + * forked off it, and it exits. */ + + assert(barrier); + assert(directory); + assert(pid_socket >= 0); + assert(uuid_socket >= 0); + assert(notify_socket >= 0); + assert(master_pty_socket >= 0); + assert(kmsg_socket >= 0); + + log_debug("Outer child is initializing."); + + r = load_os_release_pairs_with_prefix("/", "container_host_", &os_release_pairs); + if (r < 0) + log_debug_errno(r, "Failed to read os-release from host for container, ignoring: %m"); + + if (prctl(PR_SET_PDEATHSIG, SIGKILL) < 0) + return log_error_errno(errno, "PR_SET_PDEATHSIG failed: %m"); + + r = reset_audit_loginuid(); + if (r < 0) + return r; + + /* Mark everything as slave, so that we still receive mounts from the real root, but don't propagate + * mounts to the real root. */ + r = mount_follow_verbose(LOG_ERR, NULL, "/", NULL, MS_SLAVE|MS_REC, NULL); + if (r < 0) + return r; + + if (dissected_image) { + /* If we are operating on a disk image, then mount its root directory now, but leave out the + * rest. We can read the UID shift from it if we need to. Further down we'll mount the rest, + * but then with the uid shift known. That way we can mount VFAT file systems shifted to the + * right place right away. This makes sure ESP partitions and userns are compatible. */ + + r = dissected_image_mount_and_warn( + dissected_image, + directory, + arg_uid_shift, + arg_uid_range, + DISSECT_IMAGE_MOUNT_ROOT_ONLY| + DISSECT_IMAGE_DISCARD_ON_LOOP| + DISSECT_IMAGE_USR_NO_ROOT| + (arg_read_only ? DISSECT_IMAGE_READ_ONLY : DISSECT_IMAGE_FSCK|DISSECT_IMAGE_GROWFS)| + (arg_start_mode == START_BOOT ? DISSECT_IMAGE_VALIDATE_OS : 0)); + if (r < 0) + return r; + } + + r = determine_uid_shift(directory); + if (r < 0) + return r; + + if (arg_userns_mode != USER_NAMESPACE_NO) { + /* Let the parent know which UID shift we read from the image */ + l = send(uid_shift_socket, &arg_uid_shift, sizeof(arg_uid_shift), MSG_NOSIGNAL); + if (l < 0) + return log_error_errno(errno, "Failed to send UID shift: %m"); + if (l != sizeof(arg_uid_shift)) + return log_error_errno(SYNTHETIC_ERRNO(EIO), + "Short write while sending UID shift."); + + if (arg_userns_mode == USER_NAMESPACE_PICK) { + /* When we are supposed to pick the UID shift, the parent will check now whether the + * UID shift we just read from the image is available. If yes, it will send the UID + * shift back to us, if not it will pick a different one, and send it back to us. */ + + l = recv(uid_shift_socket, &arg_uid_shift, sizeof(arg_uid_shift), 0); + if (l < 0) + return log_error_errno(errno, "Failed to recv UID shift: %m"); + if (l != sizeof(arg_uid_shift)) + return log_error_errno(SYNTHETIC_ERRNO(EIO), + "Short read while receiving UID shift."); + } + + log_full(arg_quiet ? LOG_DEBUG : LOG_INFO, + "Selected user namespace base " UID_FMT " and range " UID_FMT ".", arg_uid_shift, arg_uid_range); + } + + if (path_equal(directory, "/")) { + /* If the directory we shall boot is the host, let's operate on a bind mount at a different + * place, so that we can make changes to its mount structure (for example, to implement + * --volatile=) without this interfering with our ability to access files such as + * /etc/localtime to copy into the container. Note that we use a fixed place for this + * (instead of a temporary directory, since we are living in our own mount namspace here + * already, and thus don't need to be afraid of colliding with anyone else's mounts). */ + (void) mkdir_p("/run/systemd/nspawn-root", 0755); + + r = mount_nofollow_verbose(LOG_ERR, "/", "/run/systemd/nspawn-root", NULL, MS_BIND|MS_REC, NULL); + if (r < 0) + return r; + + directory = "/run/systemd/nspawn-root"; + } + + r = setup_pivot_root( + directory, + arg_pivot_root_new, + arg_pivot_root_old); + if (r < 0) + return r; + + r = setup_volatile_mode( + directory, + arg_volatile_mode, + arg_uid_shift, + arg_selinux_apifs_context); + if (r < 0) + return r; + + r = bind_user_prepare( + directory, + arg_bind_user, + arg_uid_shift, + arg_uid_range, + &arg_custom_mounts, &arg_n_custom_mounts, + &bind_user_context); + if (r < 0) + return r; + + if (arg_userns_mode != USER_NAMESPACE_NO && bind_user_context) { + /* Send the user maps we determined to the parent, so that it installs it in our user + * namespace UID map table */ + + for (size_t i = 0; i < bind_user_context->n_data; i++) { + uid_t map[] = { + bind_user_context->data[i].payload_user->uid, + bind_user_context->data[i].host_user->uid, + (uid_t) bind_user_context->data[i].payload_group->gid, + (uid_t) bind_user_context->data[i].host_group->gid, + }; + + l = send(uid_shift_socket, map, sizeof(map), MSG_NOSIGNAL); + if (l < 0) + return log_error_errno(errno, "Failed to send user UID map: %m"); + if (l != sizeof(map)) + return log_error_errno(SYNTHETIC_ERRNO(EIO), + "Short write while sending user UID map."); + } + } + + r = mount_custom( + directory, + arg_custom_mounts, + arg_n_custom_mounts, + arg_uid_shift, + arg_uid_range, + arg_selinux_apifs_context, + MOUNT_ROOT_ONLY); + if (r < 0) + return r; + + /* Make sure we always have a mount that we can move to root later on. */ + r = make_mount_point(directory); + if (r < 0) + return r; + + if (arg_userns_mode != USER_NAMESPACE_NO && + IN_SET(arg_userns_ownership, USER_NAMESPACE_OWNERSHIP_MAP, USER_NAMESPACE_OWNERSHIP_AUTO) && + arg_uid_shift != 0) { + + r = remount_idmap(directory, arg_uid_shift, arg_uid_range, UID_INVALID, REMOUNT_IDMAPPING_HOST_ROOT); + if (r == -EINVAL || ERRNO_IS_NOT_SUPPORTED(r)) { + /* This might fail because the kernel or file system doesn't support idmapping. We + * can't really distinguish this nicely, nor do we have any guarantees about the + * error codes we see, could be EOPNOTSUPP or EINVAL. */ + if (arg_userns_ownership != USER_NAMESPACE_OWNERSHIP_AUTO) + return log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), + "ID mapped mounts are apparently not available, sorry."); + + log_debug("ID mapped mounts are apparently not available on this kernel or for the selected file system, reverting to recursive chown()ing."); + arg_userns_ownership = USER_NAMESPACE_OWNERSHIP_CHOWN; + } else if (r < 0) + return log_error_errno(r, "Failed to set up ID mapped mounts: %m"); + else { + log_debug("ID mapped mounts available, making use of them."); + idmap = true; + } + } + + if (dissected_image) { + /* Now we know the uid shift, let's now mount everything else that might be in the image. */ + r = dissected_image_mount( + dissected_image, + directory, + arg_uid_shift, + arg_uid_range, + DISSECT_IMAGE_MOUNT_NON_ROOT_ONLY| + DISSECT_IMAGE_DISCARD_ON_LOOP| + DISSECT_IMAGE_USR_NO_ROOT| + (arg_read_only ? DISSECT_IMAGE_READ_ONLY : DISSECT_IMAGE_FSCK|DISSECT_IMAGE_GROWFS)| + (idmap ? DISSECT_IMAGE_MOUNT_IDMAPPED : 0)); + if (r == -EUCLEAN) + return log_error_errno(r, "File system check for image failed: %m"); + if (r < 0) + return log_error_errno(r, "Failed to mount image file system: %m"); + } + + if (arg_unified_cgroup_hierarchy == CGROUP_UNIFIED_UNKNOWN) { + /* OK, we don't know yet which cgroup mode to use yet. Let's figure it out, and tell the parent. */ + + r = detect_unified_cgroup_hierarchy_from_image(directory); + if (r < 0) + return r; + + l = send(unified_cgroup_hierarchy_socket, &arg_unified_cgroup_hierarchy, sizeof(arg_unified_cgroup_hierarchy), MSG_NOSIGNAL); + if (l < 0) + return log_error_errno(errno, "Failed to send cgroup mode: %m"); + if (l != sizeof(arg_unified_cgroup_hierarchy)) + return log_error_errno(SYNTHETIC_ERRNO(EIO), + "Short write while sending cgroup mode."); + + unified_cgroup_hierarchy_socket = safe_close(unified_cgroup_hierarchy_socket); + } + + /* Mark everything as shared so our mounts get propagated down. This is required to make new bind + * mounts available in systemd services inside the container that create a new mount namespace. See + * https://github.com/systemd/systemd/issues/3860 Further submounts (such as /dev) done after this + * will inherit the shared propagation mode. + * + * IMPORTANT: Do not overmount the root directory anymore from now on to enable moving the root + * directory mount to root later on. + * https://github.com/systemd/systemd/issues/3847#issuecomment-562735251 + */ + r = mount_nofollow_verbose(LOG_ERR, NULL, directory, NULL, MS_SHARED|MS_REC, NULL); + if (r < 0) + return r; + + r = recursive_chown(directory, arg_uid_shift, arg_uid_range); + if (r < 0) + return r; + + r = base_filesystem_create(directory, arg_uid_shift, (gid_t) arg_uid_shift); + if (r < 0) + return r; + + if (arg_read_only && arg_volatile_mode == VOLATILE_NO && + !has_custom_root_mount(arg_custom_mounts, arg_n_custom_mounts)) { + r = bind_remount_recursive(directory, MS_RDONLY, MS_RDONLY, NULL); + if (r < 0) + return log_error_errno(r, "Failed to make tree read-only: %m"); + } + + r = mount_all(directory, + arg_mount_settings, + arg_uid_shift, + arg_selinux_apifs_context); + if (r < 0) + return r; + + r = copy_devnodes(directory); + if (r < 0) + return r; + + r = make_extra_nodes(directory); + if (r < 0) + return r; + + (void) dev_setup(directory, arg_uid_shift, arg_uid_shift); + + p = prefix_roota(directory, "/run/host"); + (void) make_inaccessible_nodes(p, arg_uid_shift, arg_uid_shift); + + r = setup_pts(directory); + if (r < 0) + return r; + + r = setup_propagate(directory); + if (r < 0) + return r; + + r = setup_keyring(); + if (r < 0) + return r; + + r = setup_credentials(directory); + if (r < 0) + return r; + + r = bind_user_setup(bind_user_context, directory); + if (r < 0) + return r; + + r = mount_custom( + directory, + arg_custom_mounts, + arg_n_custom_mounts, + arg_uid_shift, + arg_uid_range, + arg_selinux_apifs_context, + MOUNT_NON_ROOT_ONLY); + if (r < 0) + return r; + + r = setup_timezone(directory); + if (r < 0) + return r; + + r = setup_resolv_conf(directory); + if (r < 0) + return r; + + r = setup_machine_id(directory); + if (r < 0) + return r; + + r = setup_journal(directory); + if (r < 0) + return r; + + /* The same stuff as the $container env var, but nicely readable for the entire payload */ + p = prefix_roota(directory, "/run/host/container-manager"); + (void) write_string_file(p, arg_container_service_name, WRITE_STRING_FILE_CREATE); + + /* The same stuff as the $container_uuid env var */ + p = prefix_roota(directory, "/run/host/container-uuid"); + (void) write_string_filef(p, WRITE_STRING_FILE_CREATE, SD_ID128_UUID_FORMAT_STR, SD_ID128_FORMAT_VAL(arg_uuid)); + + if (!arg_use_cgns) { + r = mount_cgroups( + directory, + arg_unified_cgroup_hierarchy, + arg_userns_mode != USER_NAMESPACE_NO, + arg_uid_shift, + arg_uid_range, + arg_selinux_apifs_context, + false); + if (r < 0) + return r; + } + + r = mount_move_root(directory); + if (r < 0) + return log_error_errno(r, "Failed to move root directory: %m"); + + fd = setup_notify_child(); + if (fd < 0) + return fd; + + pid = raw_clone(SIGCHLD|CLONE_NEWNS| + arg_clone_ns_flags | + (arg_userns_mode != USER_NAMESPACE_NO ? CLONE_NEWUSER : 0)); + if (pid < 0) + return log_error_errno(errno, "Failed to fork inner child: %m"); + if (pid == 0) { + pid_socket = safe_close(pid_socket); + uuid_socket = safe_close(uuid_socket); + notify_socket = safe_close(notify_socket); + uid_shift_socket = safe_close(uid_shift_socket); + + /* The inner child has all namespaces that are requested, so that we all are owned by the + * user if user namespaces are turned on. */ + + if (arg_network_namespace_path) { + r = namespace_enter(-1, -1, netns_fd, -1, -1); + if (r < 0) + return log_error_errno(r, "Failed to join network namespace: %m"); + } + + r = inner_child(barrier, directory, secondary, kmsg_socket, rtnl_socket, master_pty_socket, fds, os_release_pairs); + if (r < 0) + _exit(EXIT_FAILURE); + + _exit(EXIT_SUCCESS); + } + + l = send(pid_socket, &pid, sizeof(pid), MSG_NOSIGNAL); + if (l < 0) + return log_error_errno(errno, "Failed to send PID: %m"); + if (l != sizeof(pid)) + return log_error_errno(SYNTHETIC_ERRNO(EIO), + "Short write while sending PID."); + + l = send(uuid_socket, &arg_uuid, sizeof(arg_uuid), MSG_NOSIGNAL); + if (l < 0) + return log_error_errno(errno, "Failed to send machine ID: %m"); + if (l != sizeof(arg_uuid)) + return log_error_errno(SYNTHETIC_ERRNO(EIO), + "Short write while sending machine ID."); + + l = send_one_fd(notify_socket, fd, 0); + if (l < 0) + return log_error_errno(l, "Failed to send notify fd: %m"); + + pid_socket = safe_close(pid_socket); + uuid_socket = safe_close(uuid_socket); + notify_socket = safe_close(notify_socket); + master_pty_socket = safe_close(master_pty_socket); + kmsg_socket = safe_close(kmsg_socket); + rtnl_socket = safe_close(rtnl_socket); + netns_fd = safe_close(netns_fd); + + return 0; +} + +static int uid_shift_pick(uid_t *shift, LockFile *ret_lock_file) { + bool tried_hashed = false; + unsigned n_tries = 100; + uid_t candidate; + int r; + + assert(shift); + assert(ret_lock_file); + assert(arg_userns_mode == USER_NAMESPACE_PICK); + assert(arg_uid_range == 0x10000U); + + candidate = *shift; + + (void) mkdir("/run/systemd/nspawn-uid", 0755); + + for (;;) { + char lock_path[STRLEN("/run/systemd/nspawn-uid/") + DECIMAL_STR_MAX(uid_t) + 1]; + _cleanup_(release_lock_file) LockFile lf = LOCK_FILE_INIT; + + if (--n_tries <= 0) + return -EBUSY; + + if (candidate < CONTAINER_UID_BASE_MIN || candidate > CONTAINER_UID_BASE_MAX) + goto next; + if ((candidate & UINT32_C(0xFFFF)) != 0) + goto next; + + xsprintf(lock_path, "/run/systemd/nspawn-uid/" UID_FMT, candidate); + r = make_lock_file(lock_path, LOCK_EX|LOCK_NB, &lf); + if (r == -EBUSY) /* Range already taken by another nspawn instance */ + goto next; + if (r < 0) + return r; + + /* Make some superficial checks whether the range is currently known in the user database */ + if (getpwuid(candidate)) + goto next; + if (getpwuid(candidate + UINT32_C(0xFFFE))) + goto next; + if (getgrgid(candidate)) + goto next; + if (getgrgid(candidate + UINT32_C(0xFFFE))) + goto next; + + *ret_lock_file = lf; + lf = (struct LockFile) LOCK_FILE_INIT; + *shift = candidate; + return 0; + + next: + if (arg_machine && !tried_hashed) { + /* Try to hash the base from the container name */ + + static const uint8_t hash_key[] = { + 0xe1, 0x56, 0xe0, 0xf0, 0x4a, 0xf0, 0x41, 0xaf, + 0x96, 0x41, 0xcf, 0x41, 0x33, 0x94, 0xff, 0x72 + }; + + candidate = (uid_t) siphash24(arg_machine, strlen(arg_machine), hash_key); + + tried_hashed = true; + } else + random_bytes(&candidate, sizeof(candidate)); + + candidate = (candidate % (CONTAINER_UID_BASE_MAX - CONTAINER_UID_BASE_MIN)) + CONTAINER_UID_BASE_MIN; + candidate &= (uid_t) UINT32_C(0xFFFF0000); + } +} + +static int add_one_uid_map( + char **p, + uid_t container_uid, + uid_t host_uid, + uid_t range) { + + return strextendf(p, + UID_FMT " " UID_FMT " " UID_FMT "\n", + container_uid, host_uid, range); +} + +static int make_uid_map_string( + const uid_t bind_user_uid[], + size_t n_bind_user_uid, + size_t offset, + char **ret) { + + _cleanup_free_ char *s = NULL; + uid_t previous_uid = 0; + int r; + + assert(n_bind_user_uid == 0 || bind_user_uid); + assert(IN_SET(offset, 0, 2)); /* used to switch between UID and GID map */ + assert(ret); + + /* The bind_user_uid[] array is a series of 4 uid_t values, for each --bind-user= entry one + * quadruplet, consisting of host and container UID + GID. */ + + for (size_t i = 0; i < n_bind_user_uid; i++) { + uid_t payload_uid = bind_user_uid[i*4+offset], + host_uid = bind_user_uid[i*4+offset+1]; + + assert(previous_uid <= payload_uid); + assert(payload_uid < arg_uid_range); + + /* Add a range to close the gap to previous entry */ + if (payload_uid > previous_uid) { + r = add_one_uid_map(&s, previous_uid, arg_uid_shift + previous_uid, payload_uid - previous_uid); + if (r < 0) + return r; + } + + /* Map this specific user */ + r = add_one_uid_map(&s, payload_uid, host_uid, 1); + if (r < 0) + return r; + + previous_uid = payload_uid + 1; + } + + /* And add a range to close the gap to finish the range */ + if (arg_uid_range > previous_uid) { + r = add_one_uid_map(&s, previous_uid, arg_uid_shift + previous_uid, arg_uid_range - previous_uid); + if (r < 0) + return r; + } + + assert(s); + + *ret = TAKE_PTR(s); + return 0; +} + +static int setup_uid_map( + pid_t pid, + const uid_t bind_user_uid[], + size_t n_bind_user_uid) { + + char uid_map[STRLEN("/proc//uid_map") + DECIMAL_STR_MAX(uid_t) + 1]; + _cleanup_free_ char *s = NULL; + int r; + + assert(pid > 1); + + /* Build the UID map string */ + if (make_uid_map_string(bind_user_uid, n_bind_user_uid, 0, &s) < 0) /* offset=0 contains the UID pair */ + return log_oom(); + + xsprintf(uid_map, "/proc/" PID_FMT "/uid_map", pid); + r = write_string_file(uid_map, s, WRITE_STRING_FILE_DISABLE_BUFFER); + if (r < 0) + return log_error_errno(r, "Failed to write UID map: %m"); + + /* And now build the GID map string */ + s = mfree(s); + if (make_uid_map_string(bind_user_uid, n_bind_user_uid, 2, &s) < 0) /* offset=2 contains the GID pair */ + return log_oom(); + + xsprintf(uid_map, "/proc/" PID_FMT "/gid_map", pid); + r = write_string_file(uid_map, s, WRITE_STRING_FILE_DISABLE_BUFFER); + if (r < 0) + return log_error_errno(r, "Failed to write GID map: %m"); + + return 0; +} + +static int nspawn_dispatch_notify_fd(sd_event_source *source, int fd, uint32_t revents, void *userdata) { + char buf[NOTIFY_BUFFER_MAX+1]; + char *p = NULL; + struct iovec iovec = { + .iov_base = buf, + .iov_len = sizeof(buf)-1, + }; + CMSG_BUFFER_TYPE(CMSG_SPACE(sizeof(struct ucred)) + + CMSG_SPACE(sizeof(int) * NOTIFY_FD_MAX)) control; + struct msghdr msghdr = { + .msg_iov = &iovec, + .msg_iovlen = 1, + .msg_control = &control, + .msg_controllen = sizeof(control), + }; + struct ucred *ucred; + ssize_t n; + pid_t inner_child_pid; + _cleanup_strv_free_ char **tags = NULL; + int r; + + assert(userdata); + + inner_child_pid = PTR_TO_PID(userdata); + + if (revents != EPOLLIN) { + log_warning("Got unexpected poll event for notify fd."); + return 0; + } + + n = recvmsg_safe(fd, &msghdr, MSG_DONTWAIT|MSG_CMSG_CLOEXEC); + if (n < 0) { + if (ERRNO_IS_TRANSIENT(n)) + return 0; + if (n == -EXFULL) { + log_warning("Got message with truncated control data (too many fds sent?), ignoring."); + return 0; + } + return log_warning_errno(n, "Couldn't read notification socket: %m"); + } + + cmsg_close_all(&msghdr); + + ucred = CMSG_FIND_DATA(&msghdr, SOL_SOCKET, SCM_CREDENTIALS, struct ucred); + if (!ucred || ucred->pid != inner_child_pid) { + log_debug("Received notify message without valid credentials. Ignoring."); + return 0; + } + + if ((size_t) n >= sizeof(buf)) { + log_warning("Received notify message exceeded maximum size. Ignoring."); + return 0; + } + + buf[n] = 0; + tags = strv_split(buf, "\n\r"); + if (!tags) + return log_oom(); + + if (strv_contains(tags, "READY=1")) { + r = sd_notify(false, "READY=1\n"); + if (r < 0) + log_warning_errno(r, "Failed to send readiness notification, ignoring: %m"); + } + + p = strv_find_startswith(tags, "STATUS="); + if (p) + (void) sd_notifyf(false, "STATUS=Container running: %s", p); + + return 0; +} + +static int setup_notify_parent(sd_event *event, int fd, pid_t *inner_child_pid, sd_event_source **notify_event_source) { + int r; + + r = sd_event_add_io(event, notify_event_source, fd, EPOLLIN, nspawn_dispatch_notify_fd, inner_child_pid); + if (r < 0) + return log_error_errno(r, "Failed to allocate notify event source: %m"); + + (void) sd_event_source_set_description(*notify_event_source, "nspawn-notify"); + + return 0; +} + +static int merge_settings(Settings *settings, const char *path) { + int rl; + + assert(settings); + assert(path); + + /* Copy over bits from the settings, unless they have been explicitly masked by command line switches. Note + * that this steals the fields of the Settings* structure, and hence modifies it. */ + + if ((arg_settings_mask & SETTING_START_MODE) == 0 && + settings->start_mode >= 0) { + arg_start_mode = settings->start_mode; + strv_free_and_replace(arg_parameters, settings->parameters); + } + + if ((arg_settings_mask & SETTING_EPHEMERAL) == 0 && + settings->ephemeral >= 0) + arg_ephemeral = settings->ephemeral; + + if ((arg_settings_mask & SETTING_DIRECTORY) == 0 && + settings->root) { + + if (!arg_settings_trusted) + log_warning("Ignoring root directory setting, file %s is not trusted.", path); + else + free_and_replace(arg_directory, settings->root); + } + + if ((arg_settings_mask & SETTING_PIVOT_ROOT) == 0 && + settings->pivot_root_new) { + free_and_replace(arg_pivot_root_new, settings->pivot_root_new); + free_and_replace(arg_pivot_root_old, settings->pivot_root_old); + } + + if ((arg_settings_mask & SETTING_WORKING_DIRECTORY) == 0 && + settings->working_directory) + free_and_replace(arg_chdir, settings->working_directory); + + if ((arg_settings_mask & SETTING_ENVIRONMENT) == 0 && + settings->environment) + strv_free_and_replace(arg_setenv, settings->environment); + + if ((arg_settings_mask & SETTING_USER) == 0) { + + if (settings->user) + free_and_replace(arg_user, settings->user); + + if (uid_is_valid(settings->uid)) + arg_uid = settings->uid; + if (gid_is_valid(settings->gid)) + arg_gid = settings->gid; + if (settings->n_supplementary_gids > 0) { + free_and_replace(arg_supplementary_gids, settings->supplementary_gids); + arg_n_supplementary_gids = settings->n_supplementary_gids; + } + } + + if ((arg_settings_mask & SETTING_CAPABILITY) == 0) { + uint64_t plus, minus; + uint64_t network_minus = 0; + uint64_t ambient; + + /* Note that we copy both the simple plus/minus caps here, and the full quintet from the + * Settings structure */ + + plus = settings->capability; + minus = settings->drop_capability; + + if ((arg_settings_mask & SETTING_NETWORK) == 0 && + settings_network_configured(settings)) { + if (settings_private_network(settings)) + plus |= UINT64_C(1) << CAP_NET_ADMIN; + else + network_minus |= UINT64_C(1) << CAP_NET_ADMIN; + } + + if (!arg_settings_trusted && plus != 0) { + if (settings->capability != 0) + log_warning("Ignoring Capability= setting, file %s is not trusted.", path); + } else { + arg_caps_retain &= ~network_minus; + arg_caps_retain |= plus; + } + + arg_caps_retain &= ~minus; + + /* Copy the full capabilities over too */ + if (capability_quintet_is_set(&settings->full_capabilities)) { + if (!arg_settings_trusted) + log_warning("Ignoring capability settings, file %s is not trusted.", path); + else + arg_full_capabilities = settings->full_capabilities; + } + + ambient = settings->ambient_capability; + if (!arg_settings_trusted && ambient != 0) + log_warning("Ignoring AmbientCapability= setting, file %s is not trusted.", path); + else + arg_caps_ambient |= ambient; + } + + if ((arg_settings_mask & SETTING_KILL_SIGNAL) == 0 && + settings->kill_signal > 0) + arg_kill_signal = settings->kill_signal; + + if ((arg_settings_mask & SETTING_PERSONALITY) == 0 && + settings->personality != PERSONALITY_INVALID) + arg_personality = settings->personality; + + if ((arg_settings_mask & SETTING_MACHINE_ID) == 0 && + !sd_id128_is_null(settings->machine_id)) { + + if (!arg_settings_trusted) + log_warning("Ignoring MachineID= setting, file %s is not trusted.", path); + else + arg_uuid = settings->machine_id; + } + + if ((arg_settings_mask & SETTING_READ_ONLY) == 0 && + settings->read_only >= 0) + arg_read_only = settings->read_only; + + if ((arg_settings_mask & SETTING_VOLATILE_MODE) == 0 && + settings->volatile_mode != _VOLATILE_MODE_INVALID) + arg_volatile_mode = settings->volatile_mode; + + if ((arg_settings_mask & SETTING_CUSTOM_MOUNTS) == 0 && + settings->n_custom_mounts > 0) { + + if (!arg_settings_trusted) + log_warning("Ignoring TemporaryFileSystem=, Bind= and BindReadOnly= settings, file %s is not trusted.", path); + else { + custom_mount_free_all(arg_custom_mounts, arg_n_custom_mounts); + arg_custom_mounts = TAKE_PTR(settings->custom_mounts); + arg_n_custom_mounts = settings->n_custom_mounts; + settings->n_custom_mounts = 0; + } + } + + if ((arg_settings_mask & SETTING_NETWORK) == 0 && + settings_network_configured(settings)) { + + if (!arg_settings_trusted) + log_warning("Ignoring network settings, file %s is not trusted.", path); + else { + arg_network_veth = settings_network_veth(settings); + arg_private_network = settings_private_network(settings); + + strv_free_and_replace(arg_network_interfaces, settings->network_interfaces); + strv_free_and_replace(arg_network_macvlan, settings->network_macvlan); + strv_free_and_replace(arg_network_ipvlan, settings->network_ipvlan); + strv_free_and_replace(arg_network_veth_extra, settings->network_veth_extra); + + free_and_replace(arg_network_bridge, settings->network_bridge); + free_and_replace(arg_network_zone, settings->network_zone); + + free_and_replace(arg_network_namespace_path, settings->network_namespace_path); + } + } + + if ((arg_settings_mask & SETTING_EXPOSE_PORTS) == 0 && + settings->expose_ports) { + + if (!arg_settings_trusted) + log_warning("Ignoring Port= setting, file %s is not trusted.", path); + else { + expose_port_free_all(arg_expose_ports); + arg_expose_ports = TAKE_PTR(settings->expose_ports); + } + } + + if ((arg_settings_mask & SETTING_USERNS) == 0 && + settings->userns_mode != _USER_NAMESPACE_MODE_INVALID) { + + if (!arg_settings_trusted) + log_warning("Ignoring PrivateUsers= and PrivateUsersChown= settings, file %s is not trusted.", path); + else { + arg_userns_mode = settings->userns_mode; + arg_uid_shift = settings->uid_shift; + arg_uid_range = settings->uid_range; + arg_userns_ownership = settings->userns_ownership; + } + } + + if ((arg_settings_mask & SETTING_BIND_USER) == 0 && + !strv_isempty(settings->bind_user)) + strv_free_and_replace(arg_bind_user, settings->bind_user); + + if ((arg_settings_mask & SETTING_NOTIFY_READY) == 0 && + settings->notify_ready >= 0) + arg_notify_ready = settings->notify_ready; + + if ((arg_settings_mask & SETTING_SYSCALL_FILTER) == 0) { + + if (!strv_isempty(settings->syscall_allow_list) || !strv_isempty(settings->syscall_deny_list)) { + if (!arg_settings_trusted && !strv_isempty(settings->syscall_allow_list)) + log_warning("Ignoring SystemCallFilter= settings, file %s is not trusted.", path); + else { + strv_free_and_replace(arg_syscall_allow_list, settings->syscall_allow_list); + strv_free_and_replace(arg_syscall_deny_list, settings->syscall_deny_list); + } + } + +#if HAVE_SECCOMP + if (settings->seccomp) { + if (!arg_settings_trusted) + log_warning("Ignoring SECCOMP filter, file %s is not trusted.", path); + else { + seccomp_release(arg_seccomp); + arg_seccomp = TAKE_PTR(settings->seccomp); + } + } +#endif + } + + for (rl = 0; rl < _RLIMIT_MAX; rl ++) { + if ((arg_settings_mask & (SETTING_RLIMIT_FIRST << rl))) + continue; + + if (!settings->rlimit[rl]) + continue; + + if (!arg_settings_trusted) { + log_warning("Ignoring Limit%s= setting, file '%s' is not trusted.", rlimit_to_string(rl), path); + continue; + } + + free_and_replace(arg_rlimit[rl], settings->rlimit[rl]); + } + + if ((arg_settings_mask & SETTING_HOSTNAME) == 0 && + settings->hostname) + free_and_replace(arg_hostname, settings->hostname); + + if ((arg_settings_mask & SETTING_NO_NEW_PRIVILEGES) == 0 && + settings->no_new_privileges >= 0) + arg_no_new_privileges = settings->no_new_privileges; + + if ((arg_settings_mask & SETTING_OOM_SCORE_ADJUST) == 0 && + settings->oom_score_adjust_set) { + + if (!arg_settings_trusted) + log_warning("Ignoring OOMScoreAdjust= setting, file '%s' is not trusted.", path); + else { + arg_oom_score_adjust = settings->oom_score_adjust; + arg_oom_score_adjust_set = true; + } + } + + if ((arg_settings_mask & SETTING_CPU_AFFINITY) == 0 && + settings->cpu_set.set) { + + if (!arg_settings_trusted) + log_warning("Ignoring CPUAffinity= setting, file '%s' is not trusted.", path); + else { + cpu_set_reset(&arg_cpu_set); + arg_cpu_set = settings->cpu_set; + settings->cpu_set = (CPUSet) {}; + } + } + + if ((arg_settings_mask & SETTING_RESOLV_CONF) == 0 && + settings->resolv_conf != _RESOLV_CONF_MODE_INVALID) + arg_resolv_conf = settings->resolv_conf; + + if ((arg_settings_mask & SETTING_LINK_JOURNAL) == 0 && + settings->link_journal != _LINK_JOURNAL_INVALID) { + + if (!arg_settings_trusted) + log_warning("Ignoring journal link setting, file '%s' is not trusted.", path); + else { + arg_link_journal = settings->link_journal; + arg_link_journal_try = settings->link_journal_try; + } + } + + if ((arg_settings_mask & SETTING_TIMEZONE) == 0 && + settings->timezone != _TIMEZONE_MODE_INVALID) + arg_timezone = settings->timezone; + + if ((arg_settings_mask & SETTING_SLICE) == 0 && + settings->slice) { + + if (!arg_settings_trusted) + log_warning("Ignoring slice setting, file '%s' is not trusted.", path); + else + free_and_replace(arg_slice, settings->slice); + } + + if ((arg_settings_mask & SETTING_USE_CGNS) == 0 && + settings->use_cgns >= 0) { + + if (!arg_settings_trusted) + log_warning("Ignoring cgroup namespace setting, file '%s' is not trusted.", path); + else + arg_use_cgns = settings->use_cgns; + } + + if ((arg_settings_mask & SETTING_CLONE_NS_FLAGS) == 0 && + settings->clone_ns_flags != ULONG_MAX) { + + if (!arg_settings_trusted) + log_warning("Ignoring namespace setting, file '%s' is not trusted.", path); + else + arg_clone_ns_flags = settings->clone_ns_flags; + } + + if ((arg_settings_mask & SETTING_CONSOLE_MODE) == 0 && + settings->console_mode >= 0) { + + if (!arg_settings_trusted) + log_warning("Ignoring console mode setting, file '%s' is not trusted.", path); + else + arg_console_mode = settings->console_mode; + } + + if ((arg_settings_mask & SETTING_SUPPRESS_SYNC) == 0 && + settings->suppress_sync >= 0) + arg_suppress_sync = settings->suppress_sync; + + /* The following properties can only be set through the OCI settings logic, not from the command line, hence we + * don't consult arg_settings_mask for them. */ + + sd_bus_message_unref(arg_property_message); + arg_property_message = TAKE_PTR(settings->properties); + + arg_console_width = settings->console_width; + arg_console_height = settings->console_height; + + device_node_array_free(arg_extra_nodes, arg_n_extra_nodes); + arg_extra_nodes = TAKE_PTR(settings->extra_nodes); + arg_n_extra_nodes = settings->n_extra_nodes; + settings->n_extra_nodes = 0; + + return 0; +} + +static int load_settings(void) { + _cleanup_(settings_freep) Settings *settings = NULL; + _cleanup_fclose_ FILE *f = NULL; + _cleanup_free_ char *p = NULL; + int r; + + if (arg_oci_bundle) + return 0; + + /* If all settings are masked, there's no point in looking for + * the settings file */ + if (FLAGS_SET(arg_settings_mask, _SETTINGS_MASK_ALL)) + return 0; + + /* We first look in the admin's directories in /etc and /run */ + FOREACH_STRING(i, "/etc/systemd/nspawn", "/run/systemd/nspawn") { + _cleanup_free_ char *j = NULL; + + j = path_join(i, arg_settings_filename); + if (!j) + return log_oom(); + + f = fopen(j, "re"); + if (f) { + p = TAKE_PTR(j); + + /* By default, we trust configuration from /etc and /run */ + if (arg_settings_trusted < 0) + arg_settings_trusted = true; + + break; + } + + if (errno != ENOENT) + return log_error_errno(errno, "Failed to open %s: %m", j); + } + + if (!f) { + /* After that, let's look for a file next to the + * actual image we shall boot. */ + + if (arg_image) { + p = file_in_same_dir(arg_image, arg_settings_filename); + if (!p) + return log_oom(); + } else if (arg_directory && !path_equal(arg_directory, "/")) { + p = file_in_same_dir(arg_directory, arg_settings_filename); + if (!p) + return log_oom(); + } + + if (p) { + f = fopen(p, "re"); + if (!f && errno != ENOENT) + return log_error_errno(errno, "Failed to open %s: %m", p); + + /* By default, we do not trust configuration from /var/lib/machines */ + if (arg_settings_trusted < 0) + arg_settings_trusted = false; + } + } + + if (!f) + return 0; + + log_debug("Settings are trusted: %s", yes_no(arg_settings_trusted)); + + r = settings_load(f, p, &settings); + if (r < 0) + return r; + + return merge_settings(settings, p); +} + +static int load_oci_bundle(void) { + _cleanup_(settings_freep) Settings *settings = NULL; + int r; + + if (!arg_oci_bundle) + return 0; + + /* By default let's trust OCI bundles */ + if (arg_settings_trusted < 0) + arg_settings_trusted = true; + + r = oci_load(NULL, arg_oci_bundle, &settings); + if (r < 0) + return r; + + return merge_settings(settings, arg_oci_bundle); +} + +static int run_container( + DissectedImage *dissected_image, + bool secondary, + FDSet *fds, + char veth_name[IFNAMSIZ], bool *veth_created, + struct ExposeArgs *expose_args, + int *master, pid_t *pid, int *ret) { + + static const struct sigaction sa = { + .sa_handler = nop_signal_handler, + .sa_flags = SA_NOCLDSTOP|SA_RESTART, + }; + + _cleanup_(release_lock_file) LockFile uid_shift_lock = LOCK_FILE_INIT; + _cleanup_close_ int etc_passwd_lock = -1; + _cleanup_close_pair_ int + kmsg_socket_pair[2] = { -1, -1 }, + rtnl_socket_pair[2] = { -1, -1 }, + pid_socket_pair[2] = { -1, -1 }, + uuid_socket_pair[2] = { -1, -1 }, + notify_socket_pair[2] = { -1, -1 }, + uid_shift_socket_pair[2] = { -1, -1 }, + master_pty_socket_pair[2] = { -1, -1 }, + unified_cgroup_hierarchy_socket_pair[2] = { -1, -1}; + + _cleanup_close_ int notify_socket = -1; + _cleanup_(barrier_destroy) Barrier barrier = BARRIER_NULL; + _cleanup_(sd_event_source_unrefp) sd_event_source *notify_event_source = NULL; + _cleanup_(sd_event_unrefp) sd_event *event = NULL; + _cleanup_(pty_forward_freep) PTYForward *forward = NULL; + _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL; + _cleanup_(sd_bus_flush_close_unrefp) sd_bus *bus = NULL; + _cleanup_free_ uid_t *bind_user_uid = NULL; + size_t n_bind_user_uid = 0; + ContainerStatus container_status = 0; + int ifi = 0, r; + ssize_t l; + sigset_t mask_chld; + _cleanup_close_ int child_netns_fd = -1; + + assert_se(sigemptyset(&mask_chld) == 0); + assert_se(sigaddset(&mask_chld, SIGCHLD) == 0); + + if (arg_userns_mode == USER_NAMESPACE_PICK) { + /* When we shall pick the UID/GID range, let's first lock /etc/passwd, so that we can safely + * check with getpwuid() if the specific user already exists. Note that /etc might be + * read-only, in which case this will fail with EROFS. But that's really OK, as in that case we + * can be reasonably sure that no users are going to be added. Note that getpwuid() checks are + * really just an extra safety net. We kinda assume that the UID range we allocate from is + * really ours. */ + + etc_passwd_lock = take_etc_passwd_lock(NULL); + if (etc_passwd_lock < 0 && etc_passwd_lock != -EROFS) + return log_error_errno(etc_passwd_lock, "Failed to take /etc/passwd lock: %m"); + } + + r = barrier_create(&barrier); + if (r < 0) + return log_error_errno(r, "Cannot initialize IPC barrier: %m"); + + if (socketpair(AF_UNIX, SOCK_SEQPACKET|SOCK_CLOEXEC, 0, kmsg_socket_pair) < 0) + return log_error_errno(errno, "Failed to create kmsg socket pair: %m"); + + if (socketpair(AF_UNIX, SOCK_SEQPACKET|SOCK_CLOEXEC, 0, rtnl_socket_pair) < 0) + return log_error_errno(errno, "Failed to create rtnl socket pair: %m"); + + if (socketpair(AF_UNIX, SOCK_SEQPACKET|SOCK_CLOEXEC, 0, pid_socket_pair) < 0) + return log_error_errno(errno, "Failed to create pid socket pair: %m"); + + if (socketpair(AF_UNIX, SOCK_SEQPACKET|SOCK_CLOEXEC, 0, uuid_socket_pair) < 0) + return log_error_errno(errno, "Failed to create id socket pair: %m"); + + if (socketpair(AF_UNIX, SOCK_SEQPACKET|SOCK_CLOEXEC, 0, notify_socket_pair) < 0) + return log_error_errno(errno, "Failed to create notify socket pair: %m"); + + if (socketpair(AF_UNIX, SOCK_SEQPACKET|SOCK_CLOEXEC, 0, master_pty_socket_pair) < 0) + return log_error_errno(errno, "Failed to create console socket pair: %m"); + + if (arg_userns_mode != USER_NAMESPACE_NO) + if (socketpair(AF_UNIX, SOCK_SEQPACKET|SOCK_CLOEXEC, 0, uid_shift_socket_pair) < 0) + return log_error_errno(errno, "Failed to create uid shift socket pair: %m"); + + if (arg_unified_cgroup_hierarchy == CGROUP_UNIFIED_UNKNOWN) + if (socketpair(AF_UNIX, SOCK_SEQPACKET|SOCK_CLOEXEC, 0, unified_cgroup_hierarchy_socket_pair) < 0) + return log_error_errno(errno, "Failed to create unified cgroup socket pair: %m"); + + /* Child can be killed before execv(), so handle SIGCHLD in order to interrupt + * parent's blocking calls and give it a chance to call wait() and terminate. */ + r = sigprocmask(SIG_UNBLOCK, &mask_chld, NULL); + if (r < 0) + return log_error_errno(errno, "Failed to change the signal mask: %m"); + + r = sigaction(SIGCHLD, &sa, NULL); + if (r < 0) + return log_error_errno(errno, "Failed to install SIGCHLD handler: %m"); + + if (arg_network_namespace_path) { + child_netns_fd = open(arg_network_namespace_path, O_RDONLY|O_NOCTTY|O_CLOEXEC); + if (child_netns_fd < 0) + return log_error_errno(errno, "Cannot open file %s: %m", arg_network_namespace_path); + + r = fd_is_ns(child_netns_fd, CLONE_NEWNET); + if (r == -EUCLEAN) + log_debug_errno(r, "Cannot determine if passed network namespace path '%s' really refers to a network namespace, assuming it does.", arg_network_namespace_path); + else if (r < 0) + return log_error_errno(r, "Failed to check %s fs type: %m", arg_network_namespace_path); + else if (r == 0) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), + "Path %s doesn't refer to a network namespace, refusing.", arg_network_namespace_path); + } + + *pid = raw_clone(SIGCHLD|CLONE_NEWNS); + if (*pid < 0) + return log_error_errno(errno, "clone() failed%s: %m", + errno == EINVAL ? + ", do you have namespace support enabled in your kernel? (You need UTS, IPC, PID and NET namespacing built in)" : ""); + + if (*pid == 0) { + /* The outer child only has a file system namespace. */ + barrier_set_role(&barrier, BARRIER_CHILD); + + kmsg_socket_pair[0] = safe_close(kmsg_socket_pair[0]); + rtnl_socket_pair[0] = safe_close(rtnl_socket_pair[0]); + pid_socket_pair[0] = safe_close(pid_socket_pair[0]); + uuid_socket_pair[0] = safe_close(uuid_socket_pair[0]); + notify_socket_pair[0] = safe_close(notify_socket_pair[0]); + master_pty_socket_pair[0] = safe_close(master_pty_socket_pair[0]); + uid_shift_socket_pair[0] = safe_close(uid_shift_socket_pair[0]); + unified_cgroup_hierarchy_socket_pair[0] = safe_close(unified_cgroup_hierarchy_socket_pair[0]); + + (void) reset_all_signal_handlers(); + (void) reset_signal_mask(); + + r = outer_child(&barrier, + arg_directory, + dissected_image, + secondary, + pid_socket_pair[1], + uuid_socket_pair[1], + notify_socket_pair[1], + kmsg_socket_pair[1], + rtnl_socket_pair[1], + uid_shift_socket_pair[1], + master_pty_socket_pair[1], + unified_cgroup_hierarchy_socket_pair[1], + fds, + child_netns_fd); + if (r < 0) + _exit(EXIT_FAILURE); + + _exit(EXIT_SUCCESS); + } + + barrier_set_role(&barrier, BARRIER_PARENT); + + fdset_close(fds); + + kmsg_socket_pair[1] = safe_close(kmsg_socket_pair[1]); + rtnl_socket_pair[1] = safe_close(rtnl_socket_pair[1]); + pid_socket_pair[1] = safe_close(pid_socket_pair[1]); + uuid_socket_pair[1] = safe_close(uuid_socket_pair[1]); + notify_socket_pair[1] = safe_close(notify_socket_pair[1]); + master_pty_socket_pair[1] = safe_close(master_pty_socket_pair[1]); + uid_shift_socket_pair[1] = safe_close(uid_shift_socket_pair[1]); + unified_cgroup_hierarchy_socket_pair[1] = safe_close(unified_cgroup_hierarchy_socket_pair[1]); + + if (arg_userns_mode != USER_NAMESPACE_NO) { + /* The child just let us know the UID shift it might have read from the image. */ + l = recv(uid_shift_socket_pair[0], &arg_uid_shift, sizeof arg_uid_shift, 0); + if (l < 0) + return log_error_errno(errno, "Failed to read UID shift: %m"); + if (l != sizeof arg_uid_shift) + return log_error_errno(SYNTHETIC_ERRNO(EIO), "Short read while reading UID shift."); + + if (arg_userns_mode == USER_NAMESPACE_PICK) { + /* If we are supposed to pick the UID shift, let's try to use the shift read from the + * image, but if that's already in use, pick a new one, and report back to the child, + * which one we now picked. */ + + r = uid_shift_pick(&arg_uid_shift, &uid_shift_lock); + if (r < 0) + return log_error_errno(r, "Failed to pick suitable UID/GID range: %m"); + + l = send(uid_shift_socket_pair[0], &arg_uid_shift, sizeof arg_uid_shift, MSG_NOSIGNAL); + if (l < 0) + return log_error_errno(errno, "Failed to send UID shift: %m"); + if (l != sizeof arg_uid_shift) + return log_error_errno(SYNTHETIC_ERRNO(EIO), "Short write while writing UID shift."); + } + + n_bind_user_uid = strv_length(arg_bind_user); + if (n_bind_user_uid > 0) { + /* Right after the UID shift, we'll receive the list of UID mappings for the + * --bind-user= logic. Always a quadruplet of payload and host UID + GID. */ + + bind_user_uid = new(uid_t, n_bind_user_uid*4); + if (!bind_user_uid) + return log_oom(); + + for (size_t i = 0; i < n_bind_user_uid; i++) { + l = recv(uid_shift_socket_pair[0], bind_user_uid + i*4, sizeof(uid_t)*4, 0); + if (l < 0) + return log_error_errno(errno, "Failed to read user UID map pair: %m"); + if (l != sizeof(uid_t)*4) + return log_full_errno(l == 0 ? LOG_DEBUG : LOG_WARNING, + SYNTHETIC_ERRNO(EIO), + "Short read while reading bind user UID pairs."); + } + } + } + + if (arg_unified_cgroup_hierarchy == CGROUP_UNIFIED_UNKNOWN) { + /* The child let us know the support cgroup mode it might have read from the image. */ + l = recv(unified_cgroup_hierarchy_socket_pair[0], &arg_unified_cgroup_hierarchy, sizeof(arg_unified_cgroup_hierarchy), 0); + if (l < 0) + return log_error_errno(errno, "Failed to read cgroup mode: %m"); + if (l != sizeof(arg_unified_cgroup_hierarchy)) + return log_error_errno(SYNTHETIC_ERRNO(EIO), "Short read while reading cgroup mode (%zi bytes).%s", + l, l == 0 ? " The child is most likely dead." : ""); + } + + /* Wait for the outer child. */ + r = wait_for_terminate_and_check("(sd-namespace)", *pid, WAIT_LOG_ABNORMAL); + if (r < 0) + return r; + if (r != EXIT_SUCCESS) + return -EIO; + + /* And now retrieve the PID of the inner child. */ + l = recv(pid_socket_pair[0], pid, sizeof *pid, 0); + if (l < 0) + return log_error_errno(errno, "Failed to read inner child PID: %m"); + if (l != sizeof *pid) + return log_error_errno(SYNTHETIC_ERRNO(EIO), "Short read while reading inner child PID."); + + /* We also retrieve container UUID in case it was generated by outer child */ + l = recv(uuid_socket_pair[0], &arg_uuid, sizeof arg_uuid, 0); + if (l < 0) + return log_error_errno(errno, "Failed to read container machine ID: %m"); + if (l != sizeof(arg_uuid)) + return log_error_errno(SYNTHETIC_ERRNO(EIO), "Short read while reading container machined ID."); + + /* We also retrieve the socket used for notifications generated by outer child */ + notify_socket = receive_one_fd(notify_socket_pair[0], 0); + if (notify_socket < 0) + return log_error_errno(notify_socket, + "Failed to receive notification socket from the outer child: %m"); + + log_debug("Init process invoked as PID "PID_FMT, *pid); + + if (arg_userns_mode != USER_NAMESPACE_NO) { + if (!barrier_place_and_sync(&barrier)) /* #1 */ + return log_error_errno(SYNTHETIC_ERRNO(ESRCH), "Child died too early."); + + r = setup_uid_map(*pid, bind_user_uid, n_bind_user_uid); + if (r < 0) + return r; + + (void) barrier_place(&barrier); /* #2 */ + } + + if (arg_private_network) { + if (!arg_network_namespace_path) { + /* Wait until the child has unshared its network namespace. */ + if (!barrier_place_and_sync(&barrier)) /* #3 */ + return log_error_errno(SYNTHETIC_ERRNO(ESRCH), "Child died too early"); + } + + if (child_netns_fd < 0) { + /* Make sure we have an open file descriptor to the child's network + * namespace so it stays alive even if the child exits. */ + r = namespace_open(*pid, NULL, NULL, &child_netns_fd, NULL, NULL); + if (r < 0) + return log_error_errno(r, "Failed to open child network namespace: %m"); + } + + r = move_network_interfaces(child_netns_fd, arg_network_interfaces); + if (r < 0) + return r; + + if (arg_network_veth) { + r = setup_veth(arg_machine, *pid, veth_name, + arg_network_bridge || arg_network_zone); + if (r < 0) + return r; + else if (r > 0) + ifi = r; + + if (arg_network_bridge) { + /* Add the interface to a bridge */ + r = setup_bridge(veth_name, arg_network_bridge, false); + if (r < 0) + return r; + if (r > 0) + ifi = r; + } else if (arg_network_zone) { + /* Add the interface to a bridge, possibly creating it */ + r = setup_bridge(veth_name, arg_network_zone, true); + if (r < 0) + return r; + if (r > 0) + ifi = r; + } + } + + r = setup_veth_extra(arg_machine, *pid, arg_network_veth_extra); + if (r < 0) + return r; + + /* We created the primary and extra veth links now; let's remember this, so that we know to + remove them later on. Note that we don't bother with removing veth links that were created + here when their setup failed half-way, because in that case the kernel should be able to + remove them on its own, since they cannot be referenced by anything yet. */ + *veth_created = true; + + r = setup_macvlan(arg_machine, *pid, arg_network_macvlan); + if (r < 0) + return r; + + r = setup_ipvlan(arg_machine, *pid, arg_network_ipvlan); + if (r < 0) + return r; + } + + if (arg_register || !arg_keep_unit) { + r = sd_bus_default_system(&bus); + if (r < 0) + return log_error_errno(r, "Failed to open system bus: %m"); + + r = sd_bus_set_close_on_exit(bus, false); + if (r < 0) + return log_error_errno(r, "Failed to disable close-on-exit behaviour: %m"); + } + + if (!arg_keep_unit) { + /* When a new scope is created for this container, then we'll be registered as its controller, in which + * case PID 1 will send us a friendly RequestStop signal, when it is asked to terminate the + * scope. Let's hook into that, and cleanly shut down the container, and print a friendly message. */ + + r = sd_bus_match_signal_async( + bus, + NULL, + "org.freedesktop.systemd1", + NULL, + "org.freedesktop.systemd1.Scope", + "RequestStop", + on_request_stop, NULL, PID_TO_PTR(*pid)); + if (r < 0) + return log_error_errno(r, "Failed to request RequestStop match: %m"); + } + + if (arg_register) { + r = register_machine( + bus, + arg_machine, + *pid, + arg_directory, + arg_uuid, + ifi, + arg_slice, + arg_custom_mounts, arg_n_custom_mounts, + arg_kill_signal, + arg_property, + arg_property_message, + arg_keep_unit, + arg_container_service_name); + if (r < 0) + return r; + + } else if (!arg_keep_unit) { + r = allocate_scope( + bus, + arg_machine, + *pid, + arg_slice, + arg_custom_mounts, arg_n_custom_mounts, + arg_kill_signal, + arg_property, + arg_property_message); + if (r < 0) + return r; + + } else if (arg_slice || arg_property) + log_notice("Machine and scope registration turned off, --slice= and --property= settings will have no effect."); + + r = create_subcgroup(*pid, arg_keep_unit, arg_unified_cgroup_hierarchy); + if (r < 0) + return r; + + r = sync_cgroup(*pid, arg_unified_cgroup_hierarchy, arg_uid_shift); + if (r < 0) + return r; + + r = chown_cgroup(*pid, arg_unified_cgroup_hierarchy, arg_uid_shift); + if (r < 0) + return r; + + /* Notify the child that the parent is ready with all + * its setup (including cgroup-ification), and that + * the child can now hand over control to the code to + * run inside the container. */ + (void) barrier_place(&barrier); /* #4 */ + + /* Block SIGCHLD here, before notifying child. + * process_pty() will handle it with the other signals. */ + assert_se(sigprocmask(SIG_BLOCK, &mask_chld, NULL) >= 0); + + /* Reset signal to default */ + r = default_signals(SIGCHLD); + if (r < 0) + return log_error_errno(r, "Failed to reset SIGCHLD: %m"); + + r = sd_event_new(&event); + if (r < 0) + return log_error_errno(r, "Failed to get default event source: %m"); + + (void) sd_event_set_watchdog(event, true); + + if (bus) { + r = sd_bus_attach_event(bus, event, 0); + if (r < 0) + return log_error_errno(r, "Failed to attach bus to event loop: %m"); + } + + r = setup_notify_parent(event, notify_socket, PID_TO_PTR(*pid), ¬ify_event_source); + if (r < 0) + return r; + + /* Let the child know that we are ready and wait that the child is completely ready now. */ + if (!barrier_place_and_sync(&barrier)) /* #5 */ + return log_error_errno(SYNTHETIC_ERRNO(ESRCH), "Child died too early."); + + /* At this point we have made use of the UID we picked, and thus nss-systemd/systemd-machined.service + * will make them appear in getpwuid(), thus we can release the /etc/passwd lock. */ + etc_passwd_lock = safe_close(etc_passwd_lock); + + (void) sd_notifyf(false, + "STATUS=Container running.\n" + "X_NSPAWN_LEADER_PID=" PID_FMT, *pid); + if (!arg_notify_ready) { + r = sd_notify(false, "READY=1\n"); + if (r < 0) + log_warning_errno(r, "Failed to send readiness notification, ignoring: %m"); + } + + if (arg_kill_signal > 0) { + /* Try to kill the init system on SIGINT or SIGTERM */ + (void) sd_event_add_signal(event, NULL, SIGINT, on_orderly_shutdown, PID_TO_PTR(*pid)); + (void) sd_event_add_signal(event, NULL, SIGTERM, on_orderly_shutdown, PID_TO_PTR(*pid)); + } else { + /* Immediately exit */ + (void) sd_event_add_signal(event, NULL, SIGINT, NULL, NULL); + (void) sd_event_add_signal(event, NULL, SIGTERM, NULL, NULL); + } + + /* Exit when the child exits */ + (void) sd_event_add_signal(event, NULL, SIGCHLD, on_sigchld, PID_TO_PTR(*pid)); + + if (arg_expose_ports) { + r = expose_port_watch_rtnl(event, rtnl_socket_pair[0], on_address_change, expose_args, &rtnl); + if (r < 0) + return r; + + (void) expose_port_execute(rtnl, &expose_args->fw_ctx, arg_expose_ports, AF_INET, &expose_args->address4); + (void) expose_port_execute(rtnl, &expose_args->fw_ctx, arg_expose_ports, AF_INET6, &expose_args->address6); + } + + rtnl_socket_pair[0] = safe_close(rtnl_socket_pair[0]); + + if (arg_console_mode != CONSOLE_PIPE) { + _cleanup_close_ int fd = -1; + PTYForwardFlags flags = 0; + + /* Retrieve the master pty allocated by inner child */ + fd = receive_one_fd(master_pty_socket_pair[0], 0); + if (fd < 0) + return log_error_errno(fd, "Failed to receive master pty from the inner child: %m"); + + switch (arg_console_mode) { + + case CONSOLE_READ_ONLY: + flags |= PTY_FORWARD_READ_ONLY; + + _fallthrough_; + + case CONSOLE_INTERACTIVE: + flags |= PTY_FORWARD_IGNORE_VHANGUP; + + r = pty_forward_new(event, fd, flags, &forward); + if (r < 0) + return log_error_errno(r, "Failed to create PTY forwarder: %m"); + + if (arg_console_width != UINT_MAX || arg_console_height != UINT_MAX) + (void) pty_forward_set_width_height(forward, + arg_console_width, + arg_console_height); + break; + + default: + assert(arg_console_mode == CONSOLE_PASSIVE); + } + + *master = TAKE_FD(fd); + } + + r = sd_event_loop(event); + if (r < 0) + return log_error_errno(r, "Failed to run event loop: %m"); + + if (forward) { + char last_char = 0; + + (void) pty_forward_get_last_char(forward, &last_char); + forward = pty_forward_free(forward); + + if (!arg_quiet && last_char != '\n') + putc('\n', stdout); + } + + /* Kill if it is not dead yet anyway */ + if (!arg_register && !arg_keep_unit && bus) + terminate_scope(bus, arg_machine); + + /* Normally redundant, but better safe than sorry */ + (void) kill(*pid, SIGKILL); + + if (arg_private_network) { + /* Move network interfaces back to the parent network namespace. We use `safe_fork` + * to avoid having to move the parent to the child network namespace. */ + r = safe_fork(NULL, FORK_RESET_SIGNALS|FORK_DEATHSIG|FORK_WAIT|FORK_LOG, NULL); + if (r < 0) + return r; + + if (r == 0) { + _cleanup_close_ int parent_netns_fd = -1; + + r = namespace_open(getpid(), NULL, NULL, &parent_netns_fd, NULL, NULL); + if (r < 0) { + log_error_errno(r, "Failed to open parent network namespace: %m"); + _exit(EXIT_FAILURE); + } + + r = namespace_enter(-1, -1, child_netns_fd, -1, -1); + if (r < 0) { + log_error_errno(r, "Failed to enter child network namespace: %m"); + _exit(EXIT_FAILURE); + } + + r = move_network_interfaces(parent_netns_fd, arg_network_interfaces); + if (r < 0) + log_error_errno(r, "Failed to move network interfaces back to parent network namespace: %m"); + + _exit(r < 0 ? EXIT_FAILURE : EXIT_SUCCESS); + } + } + + r = wait_for_container(TAKE_PID(*pid), &container_status); + + /* Tell machined that we are gone. */ + if (bus) + (void) unregister_machine(bus, arg_machine); + + if (r < 0) + /* We failed to wait for the container, or the container exited abnormally. */ + return r; + if (r > 0 || container_status == CONTAINER_TERMINATED) { + /* r > 0 → The container exited with a non-zero status. + * As a special case, we need to replace 133 with a different value, + * because 133 is special-cased in the service file to reboot the container. + * otherwise → The container exited with zero status and a reboot was not requested. + */ + if (r == EXIT_FORCE_RESTART) + r = EXIT_FAILURE; /* replace 133 with the general failure code */ + *ret = r; + return 0; /* finito */ + } + + /* CONTAINER_REBOOTED, loop again */ + + if (arg_keep_unit) { + /* Special handling if we are running as a service: instead of simply + * restarting the machine we want to restart the entire service, so let's + * inform systemd about this with the special exit code 133. The service + * file uses RestartForceExitStatus=133 so that this results in a full + * nspawn restart. This is necessary since we might have cgroup parameters + * set we want to have flushed out. */ + *ret = EXIT_FORCE_RESTART; + return 0; /* finito */ + } + + expose_port_flush(&expose_args->fw_ctx, arg_expose_ports, AF_INET, &expose_args->address4); + expose_port_flush(&expose_args->fw_ctx, arg_expose_ports, AF_INET6, &expose_args->address6); + + (void) remove_veth_links(veth_name, arg_network_veth_extra); + *veth_created = false; + return 1; /* loop again */ +} + +static int initialize_rlimits(void) { + /* The default resource limits the kernel passes to PID 1, as per kernel 5.16. Let's pass our container payload + * the same values as the kernel originally passed to PID 1, in order to minimize differences between host and + * container execution environments. */ + + static const struct rlimit kernel_defaults[_RLIMIT_MAX] = { + [RLIMIT_AS] = { RLIM_INFINITY, RLIM_INFINITY }, + [RLIMIT_CORE] = { 0, RLIM_INFINITY }, + [RLIMIT_CPU] = { RLIM_INFINITY, RLIM_INFINITY }, + [RLIMIT_DATA] = { RLIM_INFINITY, RLIM_INFINITY }, + [RLIMIT_FSIZE] = { RLIM_INFINITY, RLIM_INFINITY }, + [RLIMIT_LOCKS] = { RLIM_INFINITY, RLIM_INFINITY }, + [RLIMIT_MEMLOCK] = { DEFAULT_RLIMIT_MEMLOCK, DEFAULT_RLIMIT_MEMLOCK }, + [RLIMIT_MSGQUEUE] = { 819200, 819200 }, + [RLIMIT_NICE] = { 0, 0 }, + [RLIMIT_NOFILE] = { 1024, 4096 }, + [RLIMIT_RSS] = { RLIM_INFINITY, RLIM_INFINITY }, + [RLIMIT_RTPRIO] = { 0, 0 }, + [RLIMIT_RTTIME] = { RLIM_INFINITY, RLIM_INFINITY }, + [RLIMIT_STACK] = { 8388608, RLIM_INFINITY }, + + /* The kernel scales the default for RLIMIT_NPROC and RLIMIT_SIGPENDING based on the system's amount of + * RAM. To provide best compatibility we'll read these limits off PID 1 instead of hardcoding them + * here. This is safe as we know that PID 1 doesn't change these two limits and thus the original + * kernel's initialization should still be valid during runtime — at least if PID 1 is systemd. Note + * that PID 1 changes a number of other resource limits during early initialization which is why we + * don't read the other limits from PID 1 but prefer the static table above. */ + }; + + int rl; + + for (rl = 0; rl < _RLIMIT_MAX; rl++) { + /* Let's only fill in what the user hasn't explicitly configured anyway */ + if ((arg_settings_mask & (SETTING_RLIMIT_FIRST << rl)) == 0) { + const struct rlimit *v; + struct rlimit buffer; + + if (IN_SET(rl, RLIMIT_NPROC, RLIMIT_SIGPENDING)) { + /* For these two let's read the limits off PID 1. See above for an explanation. */ + + if (prlimit(1, rl, NULL, &buffer) < 0) + return log_error_errno(errno, "Failed to read resource limit RLIMIT_%s of PID 1: %m", rlimit_to_string(rl)); + + v = &buffer; + } else if (rl == RLIMIT_NOFILE) { + /* We nowadays bump RLIMIT_NOFILE's hard limit early in PID 1 for all + * userspace. Given that nspawn containers are often run without our PID 1, + * let's grant the containers a raised RLIMIT_NOFILE hard limit by default, + * so that container userspace gets similar resources as host userspace + * gets. */ + buffer = kernel_defaults[rl]; + buffer.rlim_max = MIN((rlim_t) read_nr_open(), (rlim_t) HIGH_RLIMIT_NOFILE); + v = &buffer; + } else + v = kernel_defaults + rl; + + arg_rlimit[rl] = newdup(struct rlimit, v, 1); + if (!arg_rlimit[rl]) + return log_oom(); + } + + if (DEBUG_LOGGING) { + _cleanup_free_ char *k = NULL; + + (void) rlimit_format(arg_rlimit[rl], &k); + log_debug("Setting RLIMIT_%s to %s.", rlimit_to_string(rl), k); + } + } + + return 0; +} + +static int cant_be_in_netns(void) { + _cleanup_close_ int fd = -1; + struct ucred ucred; + int r; + + /* Check if we are in the same netns as udev. If we aren't, then device monitoring (and thus waiting + * for loopback block devices) won't work, and we will hang. Detect this case and exit early with a + * nice message. */ + + if (!arg_image) /* only matters if --image= us used, i.e. we actually need to use loopback devices */ + return 0; + + fd = socket(AF_UNIX, SOCK_SEQPACKET|SOCK_NONBLOCK|SOCK_CLOEXEC, 0); + if (fd < 0) + return log_error_errno(errno, "Failed to allocate udev control socket: %m"); + + r = connect_unix_path(fd, AT_FDCWD, "/run/udev/control"); + if (r < 0) { + if (r == -ENOENT || ERRNO_IS_DISCONNECT(r)) + return log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), + "Sorry, but --image= requires access to the host's /run/ hierarchy, since we need access to udev."); + + return log_error_errno(r, "Failed to connect socket to udev control socket: %m"); + } + + r = getpeercred(fd, &ucred); + if (r < 0) + return log_error_errno(r, "Failed to determine peer of udev control socket: %m"); + + r = in_same_namespace(ucred.pid, 0, NAMESPACE_NET); + if (r < 0) + return log_error_errno(r, "Failed to determine network namespace of udev: %m"); + if (r == 0) + return log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), + "Sorry, but --image= is only supported in the main network namespace, since we need access to udev/AF_NETLINK."); + return 0; +} + +static int run(int argc, char *argv[]) { + bool secondary = false, remove_directory = false, remove_image = false, + veth_created = false, remove_tmprootdir = false; + _cleanup_close_ int master = -1; + _cleanup_fdset_free_ FDSet *fds = NULL; + int r, n_fd_passed, ret = EXIT_SUCCESS; + char veth_name[IFNAMSIZ] = ""; + struct ExposeArgs expose_args = {}; + _cleanup_(release_lock_file) LockFile tree_global_lock = LOCK_FILE_INIT, tree_local_lock = LOCK_FILE_INIT; + char tmprootdir[] = "/tmp/nspawn-root-XXXXXX"; + _cleanup_(loop_device_unrefp) LoopDevice *loop = NULL; + _cleanup_(dissected_image_unrefp) DissectedImage *dissected_image = NULL; + _cleanup_(fw_ctx_freep) FirewallContext *fw_ctx = NULL; + pid_t pid = 0; + + log_parse_environment(); + log_open(); + + r = parse_argv(argc, argv); + if (r <= 0) + goto finish; + + if (geteuid() != 0) { + r = log_warning_errno(SYNTHETIC_ERRNO(EPERM), + argc >= 2 ? "Need to be root." : + "Need to be root (and some arguments are usually required).\nHint: try --help"); + goto finish; + } + + r = cant_be_in_netns(); + if (r < 0) + goto finish; + + r = initialize_rlimits(); + if (r < 0) + goto finish; + + r = load_oci_bundle(); + if (r < 0) + goto finish; + + r = determine_names(); + if (r < 0) + goto finish; + + r = load_settings(); + if (r < 0) + goto finish; + + /* If we're not unsharing the network namespace and are unsharing the user namespace, we won't have + * permissions to bind ports in the container, so let's drop the CAP_NET_BIND_SERVICE capability to + * indicate that. */ + if (!arg_private_network && arg_userns_mode != USER_NAMESPACE_NO && arg_uid_shift > 0) + arg_caps_retain &= ~(UINT64_C(1) << CAP_NET_BIND_SERVICE); + + r = cg_unified(); + if (r < 0) { + log_error_errno(r, "Failed to determine whether the unified cgroups hierarchy is used: %m"); + goto finish; + } + + r = verify_arguments(); + if (r < 0) + goto finish; + + /* Reapply environment settings. */ + (void) detect_unified_cgroup_hierarchy_from_environment(); + + /* Ignore SIGPIPE here, because we use splice() on the ptyfwd stuff and that will generate SIGPIPE if + * the result is closed. Note that the container payload child will reset signal mask+handler anyway, + * so just turning this off here means we only turn it off in nspawn itself, not any children. */ + (void) ignore_signals(SIGPIPE); + + n_fd_passed = sd_listen_fds(false); + if (n_fd_passed > 0) { + r = fdset_new_listen_fds(&fds, false); + if (r < 0) { + log_error_errno(r, "Failed to collect file descriptors: %m"); + goto finish; + } + } + + /* The "default" umask. This is appropriate for most file and directory + * operations performed by nspawn, and is the umask that will be used for + * the child. Functions like copy_devnodes() change the umask temporarily. */ + umask(0022); + + if (arg_directory) { + assert(!arg_image); + + /* Safety precaution: let's not allow running images from the live host OS image, as long as + * /var from the host will propagate into container dynamically (because bad things happen if + * two systems write to the same /var). Let's allow it for the special cases where /var is + * either copied (i.e. --ephemeral) or replaced (i.e. --volatile=yes|state). */ + if (path_equal(arg_directory, "/") && !(arg_ephemeral || IN_SET(arg_volatile_mode, VOLATILE_YES, VOLATILE_STATE))) { + log_error("Spawning container on root directory is not supported. Consider using --ephemeral, --volatile=yes or --volatile=state."); + r = -EINVAL; + goto finish; + } + + if (arg_ephemeral) { + _cleanup_free_ char *np = NULL; + + r = chase_symlinks_and_update(&arg_directory, 0); + if (r < 0) + goto finish; + + /* If the specified path is a mount point we generate the new snapshot immediately + * inside it under a random name. However if the specified is not a mount point we + * create the new snapshot in the parent directory, just next to it. */ + r = path_is_mount_point(arg_directory, NULL, 0); + if (r < 0) { + log_error_errno(r, "Failed to determine whether directory %s is mount point: %m", arg_directory); + goto finish; + } + if (r > 0) + r = tempfn_random_child(arg_directory, "machine.", &np); + else + r = tempfn_random(arg_directory, "machine.", &np); + if (r < 0) { + log_error_errno(r, "Failed to generate name for directory snapshot: %m"); + goto finish; + } + + /* We take an exclusive lock on this image, since it's our private, ephemeral copy + * only owned by us and no one else. */ + r = image_path_lock(np, LOCK_EX|LOCK_NB, &tree_global_lock, &tree_local_lock); + if (r < 0) { + log_error_errno(r, "Failed to lock %s: %m", np); + goto finish; + } + + { + BLOCK_SIGNALS(SIGINT); + r = btrfs_subvol_snapshot(arg_directory, np, + (arg_read_only ? BTRFS_SNAPSHOT_READ_ONLY : 0) | + BTRFS_SNAPSHOT_FALLBACK_COPY | + BTRFS_SNAPSHOT_FALLBACK_DIRECTORY | + BTRFS_SNAPSHOT_RECURSIVE | + BTRFS_SNAPSHOT_QUOTA | + BTRFS_SNAPSHOT_SIGINT); + } + if (r == -EINTR) { + log_error_errno(r, "Interrupted while copying file system tree to %s, removed again.", np); + goto finish; + } + if (r < 0) { + log_error_errno(r, "Failed to create snapshot %s from %s: %m", np, arg_directory); + goto finish; + } + + free_and_replace(arg_directory, np); + remove_directory = true; + } else { + r = chase_symlinks_and_update(&arg_directory, arg_template ? CHASE_NONEXISTENT : 0); + if (r < 0) + goto finish; + + r = image_path_lock(arg_directory, (arg_read_only ? LOCK_SH : LOCK_EX) | LOCK_NB, &tree_global_lock, &tree_local_lock); + if (r == -EBUSY) { + log_error_errno(r, "Directory tree %s is currently busy.", arg_directory); + goto finish; + } + if (r < 0) { + log_error_errno(r, "Failed to lock %s: %m", arg_directory); + goto finish; + } + + if (arg_template) { + r = chase_symlinks_and_update(&arg_template, 0); + if (r < 0) + goto finish; + + { + BLOCK_SIGNALS(SIGINT); + r = btrfs_subvol_snapshot(arg_template, arg_directory, + (arg_read_only ? BTRFS_SNAPSHOT_READ_ONLY : 0) | + BTRFS_SNAPSHOT_FALLBACK_COPY | + BTRFS_SNAPSHOT_FALLBACK_DIRECTORY | + BTRFS_SNAPSHOT_FALLBACK_IMMUTABLE | + BTRFS_SNAPSHOT_RECURSIVE | + BTRFS_SNAPSHOT_QUOTA | + BTRFS_SNAPSHOT_SIGINT); + } + if (r == -EEXIST) + log_full(arg_quiet ? LOG_DEBUG : LOG_INFO, + "Directory %s already exists, not populating from template %s.", arg_directory, arg_template); + else if (r == -EINTR) { + log_error_errno(r, "Interrupted while copying file system tree to %s, removed again.", arg_directory); + goto finish; + } else if (r < 0) { + log_error_errno(r, "Couldn't create snapshot %s from %s: %m", arg_directory, arg_template); + goto finish; + } else + log_full(arg_quiet ? LOG_DEBUG : LOG_INFO, + "Populated %s from template %s.", arg_directory, arg_template); + } + } + + if (arg_start_mode == START_BOOT) { + _cleanup_free_ char *b = NULL; + const char *p; + + if (arg_pivot_root_new) { + b = path_join(arg_directory, arg_pivot_root_new); + if (!b) { + r = log_oom(); + goto finish; + } + + p = b; + } else + p = arg_directory; + + if (path_is_os_tree(p) <= 0) { + r = log_error_errno(SYNTHETIC_ERRNO(EINVAL), + "Directory %s doesn't look like an OS root directory (os-release file is missing). Refusing.", p); + goto finish; + } + } else { + _cleanup_free_ char *p = NULL; + + if (arg_pivot_root_new) + p = path_join(arg_directory, arg_pivot_root_new, "/usr/"); + else + p = path_join(arg_directory, "/usr/"); + if (!p) { + r = log_oom(); + goto finish; + } + + if (laccess(p, F_OK) < 0) { + r = log_error_errno(SYNTHETIC_ERRNO(EINVAL), + "Directory %s doesn't look like it has an OS tree (/usr/ directory is missing). Refusing.", arg_directory); + goto finish; + } + } + + } else { + DissectImageFlags dissect_image_flags = + DISSECT_IMAGE_GENERIC_ROOT | + DISSECT_IMAGE_REQUIRE_ROOT | + DISSECT_IMAGE_RELAX_VAR_CHECK | + DISSECT_IMAGE_USR_NO_ROOT | + DISSECT_IMAGE_ADD_PARTITION_DEVICES | + DISSECT_IMAGE_PIN_PARTITION_DEVICES; + assert(arg_image); + assert(!arg_template); + + r = chase_symlinks_and_update(&arg_image, 0); + if (r < 0) + goto finish; + + if (arg_ephemeral) { + _cleanup_free_ char *np = NULL; + + r = tempfn_random(arg_image, "machine.", &np); + if (r < 0) { + log_error_errno(r, "Failed to generate name for image snapshot: %m"); + goto finish; + } + + /* Always take an exclusive lock on our own ephemeral copy. */ + r = image_path_lock(np, LOCK_EX|LOCK_NB, &tree_global_lock, &tree_local_lock); + if (r < 0) { + r = log_error_errno(r, "Failed to create image lock: %m"); + goto finish; + } + + { + BLOCK_SIGNALS(SIGINT); + r = copy_file(arg_image, np, O_EXCL, arg_read_only ? 0400 : 0600, FS_NOCOW_FL, FS_NOCOW_FL, COPY_REFLINK|COPY_CRTIME|COPY_SIGINT); + } + if (r == -EINTR) { + log_error_errno(r, "Interrupted while copying image file to %s, removed again.", np); + goto finish; + } + if (r < 0) { + r = log_error_errno(r, "Failed to copy image file: %m"); + goto finish; + } + + free_and_replace(arg_image, np); + remove_image = true; + } else { + r = image_path_lock(arg_image, (arg_read_only ? LOCK_SH : LOCK_EX) | LOCK_NB, &tree_global_lock, &tree_local_lock); + if (r == -EBUSY) { + r = log_error_errno(r, "Disk image %s is currently busy.", arg_image); + goto finish; + } + if (r < 0) { + r = log_error_errno(r, "Failed to create image lock: %m"); + goto finish; + } + + r = verity_settings_load( + &arg_verity_settings, + arg_image, NULL, NULL); + if (r < 0) { + log_error_errno(r, "Failed to read verity artefacts for %s: %m", arg_image); + goto finish; + } + + if (arg_verity_settings.data_path) + dissect_image_flags |= DISSECT_IMAGE_NO_PARTITION_TABLE; + } + + if (!mkdtemp(tmprootdir)) { + r = log_error_errno(errno, "Failed to create temporary directory: %m"); + goto finish; + } + + remove_tmprootdir = true; + + arg_directory = strdup(tmprootdir); + if (!arg_directory) { + r = log_oom(); + goto finish; + } + + r = loop_device_make_by_path( + arg_image, + arg_read_only ? O_RDONLY : O_RDWR, + FLAGS_SET(dissect_image_flags, DISSECT_IMAGE_NO_PARTITION_TABLE) ? 0 : LO_FLAGS_PARTSCAN, + LOCK_SH, + &loop); + if (r < 0) { + log_error_errno(r, "Failed to set up loopback block device: %m"); + goto finish; + } + + r = dissect_loop_device_and_warn( + loop, + &arg_verity_settings, + NULL, + dissect_image_flags, + &dissected_image); + if (r == -ENOPKG) { + /* dissected_image_and_warn() already printed a brief error message. Extend on that with more details */ + log_notice("Note that the disk image needs to\n" + " a) either contain only a single MBR partition of type 0x83 that is marked bootable\n" + " b) or contain a single GPT partition of type 0FC63DAF-8483-4772-8E79-3D69D8477DE4\n" + " c) or follow https://systemd.io/DISCOVERABLE_PARTITIONS\n" + " d) or contain a file system without a partition table\n" + "in order to be bootable with systemd-nspawn."); + goto finish; + } + if (r < 0) + goto finish; + + r = dissected_image_load_verity_sig_partition( + dissected_image, + loop->fd, + &arg_verity_settings); + if (r < 0) + goto finish; + + if (dissected_image->has_verity && !arg_verity_settings.root_hash && !dissected_image->has_verity_sig) + log_notice("Note: image %s contains verity information, but no root hash specified and no embedded " + "root hash signature found! Proceeding without integrity checking.", arg_image); + + r = dissected_image_decrypt_interactively( + dissected_image, + NULL, + &arg_verity_settings, + 0); + if (r < 0) + goto finish; + + /* Now that we mounted the image, let's try to remove it again, if it is ephemeral */ + if (remove_image && unlink(arg_image) >= 0) + remove_image = false; + } + + r = custom_mount_prepare_all(arg_directory, arg_custom_mounts, arg_n_custom_mounts); + if (r < 0) + goto finish; + + if (arg_console_mode < 0) + arg_console_mode = + isatty(STDIN_FILENO) > 0 && + isatty(STDOUT_FILENO) > 0 ? CONSOLE_INTERACTIVE : CONSOLE_READ_ONLY; + + if (arg_console_mode == CONSOLE_PIPE) /* if we pass STDERR on to the container, don't add our own logs into it too */ + arg_quiet = true; + + if (!arg_quiet) + log_info("Spawning container %s on %s.\nPress ^] three times within 1s to kill container.", + arg_machine, arg_image ?: arg_directory); + + assert_se(sigprocmask_many(SIG_BLOCK, NULL, SIGCHLD, SIGWINCH, SIGTERM, SIGINT, -1) >= 0); + + if (prctl(PR_SET_CHILD_SUBREAPER, 1, 0, 0, 0) < 0) { + r = log_error_errno(errno, "Failed to become subreaper: %m"); + goto finish; + } + + if (arg_expose_ports) { + r = fw_ctx_new(&fw_ctx); + if (r < 0) { + log_error_errno(r, "Cannot expose configured ports, firewall initialization failed: %m"); + goto finish; + } + expose_args.fw_ctx = fw_ctx; + } + for (;;) { + r = run_container(dissected_image, + secondary, + fds, + veth_name, &veth_created, + &expose_args, &master, + &pid, &ret); + if (r <= 0) + break; + } + +finish: + (void) sd_notify(false, + r == 0 && ret == EXIT_FORCE_RESTART ? "STOPPING=1\nSTATUS=Restarting..." : + "STOPPING=1\nSTATUS=Terminating..."); + + if (pid > 0) + (void) kill(pid, SIGKILL); + + /* Try to flush whatever is still queued in the pty */ + if (master >= 0) { + (void) copy_bytes(master, STDOUT_FILENO, UINT64_MAX, 0); + master = safe_close(master); + } + + if (pid > 0) + (void) wait_for_terminate(pid, NULL); + + pager_close(); + + if (remove_directory && arg_directory) { + int k; + + k = rm_rf(arg_directory, REMOVE_ROOT|REMOVE_PHYSICAL|REMOVE_SUBVOLUME); + if (k < 0) + log_warning_errno(k, "Cannot remove '%s', ignoring: %m", arg_directory); + } + + if (remove_image && arg_image) { + if (unlink(arg_image) < 0) + log_warning_errno(errno, "Can't remove image file '%s', ignoring: %m", arg_image); + } + + if (remove_tmprootdir) { + if (rmdir(tmprootdir) < 0) + log_debug_errno(errno, "Can't remove temporary root directory '%s', ignoring: %m", tmprootdir); + } + + if (arg_machine) { + const char *p; + + p = strjoina("/run/systemd/nspawn/propagate/", arg_machine); + (void) rm_rf(p, REMOVE_ROOT); + } + + expose_port_flush(&fw_ctx, arg_expose_ports, AF_INET, &expose_args.address4); + expose_port_flush(&fw_ctx, arg_expose_ports, AF_INET6, &expose_args.address6); + + if (veth_created) + (void) remove_veth_links(veth_name, arg_network_veth_extra); + (void) remove_bridge(arg_network_zone); + + custom_mount_free_all(arg_custom_mounts, arg_n_custom_mounts); + expose_port_free_all(arg_expose_ports); + rlimit_free_all(arg_rlimit); + device_node_array_free(arg_extra_nodes, arg_n_extra_nodes); + credential_free_all(arg_credentials, arg_n_credentials); + + if (r < 0) + return r; + + return ret; +} + +DEFINE_MAIN_FUNCTION_WITH_POSITIVE_FAILURE(run); diff --git a/src/nspawn/nspawn.h b/src/nspawn/nspawn.h new file mode 100644 index 0000000..27fb0b4 --- /dev/null +++ b/src/nspawn/nspawn.h @@ -0,0 +1,7 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ +#pragma once + +#include <sys/types.h> + +int userns_lchown(const char *p, uid_t uid, gid_t gid); +int userns_mkdir(const char *root, const char *path, mode_t mode, uid_t uid, gid_t gid); diff --git a/src/nspawn/test-nspawn-tables.c b/src/nspawn/test-nspawn-tables.c new file mode 100644 index 0000000..3baf5d3 --- /dev/null +++ b/src/nspawn/test-nspawn-tables.c @@ -0,0 +1,11 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include "nspawn-settings.h" +#include "test-tables.h" + +int main(int argc, char **argv) { + test_table(resolv_conf_mode, RESOLV_CONF_MODE); + test_table(timezone_mode, TIMEZONE_MODE); + + return 0; +} diff --git a/src/nspawn/test-nspawn-util.c b/src/nspawn/test-nspawn-util.c new file mode 100644 index 0000000..08c8050 --- /dev/null +++ b/src/nspawn/test-nspawn-util.c @@ -0,0 +1,22 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include "nspawn-util.h" +#include "string-util.h" +#include "strv.h" +#include "tests.h" + +TEST(systemd_installation_has_version) { + int r; + + FOREACH_STRING(version, "0", "231", STRINGIFY(PROJECT_VERSION), "999") { + r = systemd_installation_has_version(saved_argv[1], version); + assert_se(r >= 0); + log_info("%s has systemd >= %s: %s", + saved_argv[1] ?: "Current installation", version, yes_no(r)); + } +} + +/* This program can be called with a path to an installation root. + * For example: build/test-nspawn-util /var/lib/machines/rawhide + */ +DEFINE_TEST_MAIN(LOG_DEBUG); diff --git a/src/nspawn/test-patch-uid.c b/src/nspawn/test-patch-uid.c new file mode 100644 index 0000000..f8f44b0 --- /dev/null +++ b/src/nspawn/test-patch-uid.c @@ -0,0 +1,43 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include <stdlib.h> + +#include "log.h" +#include "nspawn-patch-uid.h" +#include "user-util.h" +#include "string-util.h" +#include "tests.h" + +int main(int argc, char *argv[]) { + uid_t shift, range; + int r; + + test_setup_logging(LOG_DEBUG); + + if (argc != 4) { + log_error("Expected PATH SHIFT RANGE parameters."); + return EXIT_FAILURE; + } + + r = parse_uid(argv[2], &shift); + if (r < 0) { + log_error_errno(r, "Failed to parse UID shift %s.", argv[2]); + return EXIT_FAILURE; + } + + r = parse_gid(argv[3], &range); + if (r < 0) { + log_error_errno(r, "Failed to parse UID range %s.", argv[3]); + return EXIT_FAILURE; + } + + r = path_patch_uid(argv[1], shift, range); + if (r < 0) { + log_error_errno(r, "Failed to patch directory tree: %m"); + return EXIT_FAILURE; + } + + log_info("Changed: %s", yes_no(r)); + + return EXIT_SUCCESS; +} |