diff options
Diffstat (limited to '')
| -rw-r--r-- | src/machine/machined-varlink.c | 423 |
1 files changed, 423 insertions, 0 deletions
diff --git a/src/machine/machined-varlink.c b/src/machine/machined-varlink.c new file mode 100644 index 0000000..2d6c199 --- /dev/null +++ b/src/machine/machined-varlink.c @@ -0,0 +1,423 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include "format-util.h" +#include "machined-varlink.h" +#include "mkdir.h" +#include "user-util.h" +#include "varlink.h" + +typedef struct LookupParameters { + const char *user_name; + const char *group_name; + union { + uid_t uid; + gid_t gid; + }; + const char *service; +} LookupParameters; + +static int build_user_json(const char *user_name, uid_t uid, const char *real_name, JsonVariant **ret) { + assert(user_name); + assert(uid_is_valid(uid)); + assert(ret); + + return json_build(ret, JSON_BUILD_OBJECT( + JSON_BUILD_PAIR("record", JSON_BUILD_OBJECT( + JSON_BUILD_PAIR("userName", JSON_BUILD_STRING(user_name)), + JSON_BUILD_PAIR("uid", JSON_BUILD_UNSIGNED(uid)), + JSON_BUILD_PAIR("gid", JSON_BUILD_UNSIGNED(GID_NOBODY)), + JSON_BUILD_PAIR_CONDITION(!isempty(real_name), "realName", JSON_BUILD_STRING(real_name)), + JSON_BUILD_PAIR("homeDirectory", JSON_BUILD_STRING("/")), + JSON_BUILD_PAIR("shell", JSON_BUILD_STRING(NOLOGIN)), + JSON_BUILD_PAIR("locked", JSON_BUILD_BOOLEAN(true)), + JSON_BUILD_PAIR("service", JSON_BUILD_STRING("io.systemd.Machine")), + JSON_BUILD_PAIR("disposition", JSON_BUILD_STRING("container")))))); +} + +static bool user_match_lookup_parameters(LookupParameters *p, const char *name, uid_t uid) { + assert(p); + + if (p->user_name && !streq(name, p->user_name)) + return false; + + if (uid_is_valid(p->uid) && uid != p->uid) + return false; + + return true; +} + +static int user_lookup_uid(Manager *m, uid_t uid, char **ret_name, char **ret_real_name) { + _cleanup_free_ char *n = NULL, *rn = NULL; + uid_t converted_uid; + Machine *machine; + int r; + + assert(m); + assert(uid_is_valid(uid)); + assert(ret_name); + assert(ret_real_name); + + if (uid < 0x10000) /* Host UID range */ + return -ESRCH; + + r = manager_find_machine_for_uid(m, uid, &machine, &converted_uid); + if (r < 0) + return r; + if (!r) + return -ESRCH; + + if (asprintf(&n, "vu-%s-" UID_FMT, machine->name, converted_uid) < 0) + return -ENOMEM; + + /* Don't synthesize invalid user/group names (too long...) */ + if (!valid_user_group_name(n, 0)) + return -ESRCH; + + if (asprintf(&rn, "UID " UID_FMT " of Container %s", converted_uid, machine->name) < 0) + return -ENOMEM; + + /* Don't synthesize invalid real names either, but since this field doesn't matter much, simply invalidate things */ + if (!valid_gecos(rn)) + rn = mfree(rn); + + *ret_name = TAKE_PTR(n); + *ret_real_name = TAKE_PTR(rn); + return 0; +} + +static int user_lookup_name(Manager *m, const char *name, uid_t *ret_uid, char **ret_real_name) { + _cleanup_free_ char *mn = NULL, *rn = NULL; + uid_t uid, converted_uid; + Machine *machine; + const char *e, *d; + int r; + + assert(m); + assert(ret_uid); + assert(ret_real_name); + + if (!valid_user_group_name(name, 0)) + return -ESRCH; + + e = startswith(name, "vu-"); + if (!e) + return -ESRCH; + + d = strrchr(e, '-'); + if (!d) + return -ESRCH; + + if (parse_uid(d + 1, &uid) < 0) + return -ESRCH; + + mn = strndup(e, d - e); + if (!mn) + return -ENOMEM; + + machine = hashmap_get(m->machines, mn); + if (!machine) + return -ESRCH; + + if (machine->class != MACHINE_CONTAINER) + return -ESRCH; + + r = machine_translate_uid(machine, uid, &converted_uid); + if (r < 0) + return r; + + if (asprintf(&rn, "UID " UID_FMT " of Container %s", uid, machine->name) < 0) + return -ENOMEM; + if (!valid_gecos(rn)) + rn = mfree(rn); + + *ret_uid = converted_uid; + *ret_real_name = TAKE_PTR(rn); + return 0; +} + +static int vl_method_get_user_record(Varlink *link, JsonVariant *parameters, VarlinkMethodFlags flags, void *userdata) { + + static const JsonDispatch dispatch_table[] = { + { "uid", JSON_VARIANT_UNSIGNED, json_dispatch_uid_gid, offsetof(LookupParameters, uid), 0 }, + { "userName", JSON_VARIANT_STRING, json_dispatch_const_string, offsetof(LookupParameters, user_name), JSON_SAFE }, + { "service", JSON_VARIANT_STRING, json_dispatch_const_string, offsetof(LookupParameters, service), 0 }, + {} + }; + + _cleanup_(json_variant_unrefp) JsonVariant *v = NULL; + LookupParameters p = { + .uid = UID_INVALID, + }; + _cleanup_free_ char *found_name = NULL, *found_real_name = NULL; + uid_t found_uid = UID_INVALID, uid; + Manager *m = userdata; + const char *un; + int r; + + assert(parameters); + assert(m); + + r = json_dispatch(parameters, dispatch_table, NULL, 0, &p); + if (r < 0) + return r; + + if (!streq_ptr(p.service, "io.systemd.Machine")) + return varlink_error(link, "io.systemd.UserDatabase.BadService", NULL); + + if (uid_is_valid(p.uid)) + r = user_lookup_uid(m, p.uid, &found_name, &found_real_name); + else if (p.user_name) + r = user_lookup_name(m, p.user_name, &found_uid, &found_real_name); + else + return varlink_error(link, "io.systemd.UserDatabase.EnumerationNotSupported", NULL); + if (r == -ESRCH) + return varlink_error(link, "io.systemd.UserDatabase.NoRecordFound", NULL); + if (r < 0) + return r; + + uid = uid_is_valid(found_uid) ? found_uid : p.uid; + un = found_name ?: p.user_name; + + if (!user_match_lookup_parameters(&p, un, uid)) + return varlink_error(link, "io.systemd.UserDatabase.ConflictingRecordFound", NULL); + + r = build_user_json(un, uid, found_real_name, &v); + if (r < 0) + return r; + + return varlink_reply(link, v); +} + +static int build_group_json(const char *group_name, gid_t gid, const char *description, JsonVariant **ret) { + assert(group_name); + assert(gid_is_valid(gid)); + assert(ret); + + return json_build(ret, JSON_BUILD_OBJECT( + JSON_BUILD_PAIR("record", JSON_BUILD_OBJECT( + JSON_BUILD_PAIR("groupName", JSON_BUILD_STRING(group_name)), + JSON_BUILD_PAIR("gid", JSON_BUILD_UNSIGNED(gid)), + JSON_BUILD_PAIR_CONDITION(!isempty(description), "description", JSON_BUILD_STRING(description)), + JSON_BUILD_PAIR("service", JSON_BUILD_STRING("io.systemd.Machine")), + JSON_BUILD_PAIR("disposition", JSON_BUILD_STRING("container")))))); + } + +static bool group_match_lookup_parameters(LookupParameters *p, const char *name, gid_t gid) { + assert(p); + + if (p->group_name && !streq(name, p->group_name)) + return false; + + if (gid_is_valid(p->gid) && gid != p->gid) + return false; + + return true; +} + +static int group_lookup_gid(Manager *m, gid_t gid, char **ret_name, char **ret_description) { + _cleanup_free_ char *n = NULL, *d = NULL; + gid_t converted_gid; + Machine *machine; + int r; + + assert(m); + assert(gid_is_valid(gid)); + assert(ret_name); + assert(ret_description); + + if (gid < 0x10000) /* Host GID range */ + return -ESRCH; + + r = manager_find_machine_for_gid(m, gid, &machine, &converted_gid); + if (r < 0) + return r; + if (!r) + return -ESRCH; + + if (asprintf(&n, "vg-%s-" GID_FMT, machine->name, converted_gid) < 0) + return -ENOMEM; + + if (!valid_user_group_name(n, 0)) + return -ESRCH; + + if (asprintf(&d, "GID " GID_FMT " of Container %s", converted_gid, machine->name) < 0) + return -ENOMEM; + if (!valid_gecos(d)) + d = mfree(d); + + *ret_name = TAKE_PTR(n); + *ret_description = TAKE_PTR(d); + + return 0; +} + +static int group_lookup_name(Manager *m, const char *name, gid_t *ret_gid, char **ret_description) { + _cleanup_free_ char *mn = NULL, *desc = NULL; + gid_t gid, converted_gid; + Machine *machine; + const char *e, *d; + int r; + + assert(m); + assert(ret_gid); + assert(ret_description); + + if (!valid_user_group_name(name, 0)) + return -ESRCH; + + e = startswith(name, "vg-"); + if (!e) + return -ESRCH; + + d = strrchr(e, '-'); + if (!d) + return -ESRCH; + + if (parse_gid(d + 1, &gid) < 0) + return -ESRCH; + + mn = strndup(e, d - e); + if (!mn) + return -ENOMEM; + + machine = hashmap_get(m->machines, mn); + if (!machine) + return -ESRCH; + + if (machine->class != MACHINE_CONTAINER) + return -ESRCH; + + r = machine_translate_gid(machine, gid, &converted_gid); + if (r < 0) + return r; + + if (asprintf(&desc, "GID " GID_FMT " of Container %s", gid, machine->name) < 0) + return -ENOMEM; + if (!valid_gecos(desc)) + desc = mfree(desc); + + *ret_gid = converted_gid; + *ret_description = desc; + return 0; +} + +static int vl_method_get_group_record(Varlink *link, JsonVariant *parameters, VarlinkMethodFlags flags, void *userdata) { + + static const JsonDispatch dispatch_table[] = { + { "gid", JSON_VARIANT_UNSIGNED, json_dispatch_uid_gid, offsetof(LookupParameters, gid), 0 }, + { "groupName", JSON_VARIANT_STRING, json_dispatch_const_string, offsetof(LookupParameters, group_name), JSON_SAFE }, + { "service", JSON_VARIANT_STRING, json_dispatch_const_string, offsetof(LookupParameters, service), 0 }, + {} + }; + + _cleanup_(json_variant_unrefp) JsonVariant *v = NULL; + LookupParameters p = { + .gid = GID_INVALID, + }; + _cleanup_free_ char *found_name = NULL, *found_description = NULL; + uid_t found_gid = GID_INVALID, gid; + Manager *m = userdata; + const char *gn; + int r; + + assert(parameters); + assert(m); + + r = json_dispatch(parameters, dispatch_table, NULL, 0, &p); + if (r < 0) + return r; + + if (!streq_ptr(p.service, "io.systemd.Machine")) + return varlink_error(link, "io.systemd.UserDatabase.BadService", NULL); + + if (gid_is_valid(p.gid)) + r = group_lookup_gid(m, p.gid, &found_name, &found_description); + else if (p.group_name) + r = group_lookup_name(m, p.group_name, (uid_t*) &found_gid, &found_description); + else + return varlink_error(link, "io.systemd.UserDatabase.EnumerationNotSupported", NULL); + if (r == -ESRCH) + return varlink_error(link, "io.systemd.UserDatabase.NoRecordFound", NULL); + if (r < 0) + return r; + + gid = gid_is_valid(found_gid) ? found_gid : p.gid; + gn = found_name ?: p.group_name; + + if (!group_match_lookup_parameters(&p, gn, gid)) + return varlink_error(link, "io.systemd.UserDatabase.ConflictingRecordFound", NULL); + + r = build_group_json(gn, gid, found_description, &v); + if (r < 0) + return r; + + return varlink_reply(link, v); +} + +static int vl_method_get_memberships(Varlink *link, JsonVariant *parameters, VarlinkMethodFlags flags, void *userdata) { + + static const JsonDispatch dispatch_table[] = { + { "userName", JSON_VARIANT_STRING, json_dispatch_const_string, offsetof(LookupParameters, user_name), JSON_SAFE }, + { "groupName", JSON_VARIANT_STRING, json_dispatch_const_string, offsetof(LookupParameters, group_name), JSON_SAFE }, + { "service", JSON_VARIANT_STRING, json_dispatch_const_string, offsetof(LookupParameters, service), 0 }, + {} + }; + + LookupParameters p = {}; + int r; + + assert(parameters); + + r = json_dispatch(parameters, dispatch_table, NULL, 0, &p); + if (r < 0) + return r; + + if (!streq_ptr(p.service, "io.systemd.Machine")) + return varlink_error(link, "io.systemd.UserDatabase.BadService", NULL); + + /* We don't support auxiliary groups for machines. */ + return varlink_error(link, "io.systemd.UserDatabase.NoRecordFound", NULL); +} + +int manager_varlink_init(Manager *m) { + _cleanup_(varlink_server_unrefp) VarlinkServer *s = NULL; + int r; + + assert(m); + + if (m->varlink_server) + return 0; + + r = varlink_server_new(&s, VARLINK_SERVER_ACCOUNT_UID); + if (r < 0) + return log_error_errno(r, "Failed to allocate varlink server object: %m"); + + varlink_server_set_userdata(s, m); + + r = varlink_server_bind_method_many( + s, + "io.systemd.UserDatabase.GetUserRecord", vl_method_get_user_record, + "io.systemd.UserDatabase.GetGroupRecord", vl_method_get_group_record, + "io.systemd.UserDatabase.GetMemberships", vl_method_get_memberships); + if (r < 0) + return log_error_errno(r, "Failed to register varlink methods: %m"); + + (void) mkdir_p("/run/systemd/userdb", 0755); + + r = varlink_server_listen_address(s, "/run/systemd/userdb/io.systemd.Machine", 0666); + if (r < 0) + return log_error_errno(r, "Failed to bind to varlink socket: %m"); + + r = varlink_server_attach_event(s, m->event, SD_EVENT_PRIORITY_NORMAL); + if (r < 0) + return log_error_errno(r, "Failed to attach varlink connection to event loop: %m"); + + m->varlink_server = TAKE_PTR(s); + return 0; +} + +void manager_varlink_done(Manager *m) { + assert(m); + + m->varlink_server = varlink_server_unref(m->varlink_server); +} |