diff options
Diffstat (limited to 'src/nspawn/nspawn.c')
| -rw-r--r-- | src/nspawn/nspawn.c | 5870 |
1 files changed, 5870 insertions, 0 deletions
diff --git a/src/nspawn/nspawn.c b/src/nspawn/nspawn.c new file mode 100644 index 0000000..e46cc1c --- /dev/null +++ b/src/nspawn/nspawn.c @@ -0,0 +1,5870 @@ +/* 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 "ether-addr-util.h" +#include "barrier.h" +#include "base-filesystem.h" +#include "blkid-util.h" +#include "btrfs-util.h" +#include "build.h" +#include "bus-error.h" +#include "bus-locator.h" +#include "bus-util.h" +#include "cap-list.h" +#include "capability-util.h" +#include "cgroup-util.h" +#include "chase.h" +#include "common-signal.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 "machine-credential.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-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" +#include "seccomp-util.h" +#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" + +/* 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 NSPAWN_MOUNT_TUNNEL "/run/host/incoming" + +#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; +struct ether_addr arg_network_provided_mac = {}; +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 MachineCredential *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 Architecture arg_architecture = _ARCHITECTURE_INVALID; +static ImagePolicy *arg_image_policy = 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_DESTRUCTOR_REGISTER(arg_image_policy, image_policy_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$s\n" + " -D --directory=PATH Root directory for the container\n" + " --template=PATH Initialize root directory from template directory,\n" + " if missing\n" + " -x --ephemeral Run container with snapshot of root directory, and\n" + " remove it after exit\n" + " -i --image=PATH Root file system disk image (or device node) for\n" + " the container\n" + " --image-policy=POLICY Specify disk image dissection policy\n" + " --oci-bundle=PATH OCI bundle directory\n" + " --read-only Mount the root directory read-only\n" + " --volatile[=MODE] Run the system in volatile mode\n" + " --root-hash=HASH Specify verity root hash for root disk image\n" + " --root-hash-sig=SIG Specify pkcs7 signature of root hash for verity\n" + " as a DER encoded PKCS7, either as a path to a file\n" + " or as an ASCII base64 encoded string prefixed by\n" + " 'base64:'\n" + " --verity-data=PATH Specify hash device for verity\n" + " --pivot-root=PATH[:PATH]\n" + " Pivot root to given directory in the container\n\n" + "%3$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$s\n" + " --private-network Disable network in container\n" + " --network-interface=HOSTIF[:CONTAINERIF]\n" + " Assign an existing network interface to the\n" + " container\n" + " --network-macvlan=HOSTIF[:CONTAINERIF]\n" + " Create a macvlan network interface based on an\n" + " existing network interface to the container\n" + " --network-ipvlan=HOSTIF[:CONTAINERIF]\n" + " Create an ipvlan network interface based on an\n" + " existing network interface to the container\n" + " -n --network-veth Add a virtual Ethernet connection between host\n" + " and container\n" + " --network-veth-extra=HOSTIF[:CONTAINERIF]\n" + " Add an additional virtual Ethernet link between\n" + " host and container\n" + " --network-bridge=INTERFACE\n" + " Add a virtual Ethernet connection to the container\n" + " and attach it to an existing bridge on the host\n" + " --network-zone=NAME Similar, but attach the new interface to an\n" + " an automatically managed bridge interface\n" + " --network-namespace-path=PATH\n" + " Set network namespace to the one represented by\n" + " the specified kernel namespace file node\n" + " -p --port=[PROTOCOL:]HOSTPORT[:CONTAINERPORT]\n" + " Expose a container IP port on the host\n\n" + "%3$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; + + e = getenv("SYSTEMD_NSPAWN_NETWORK_MAC"); + if (e) { + r = parse_ether_addr(e, &arg_network_provided_mac); + if (r < 0) + return log_error_errno(r, "Failed to parse provided MAC address via environment variable"); + } + + 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, + ARG_IMAGE_POLICY, + }; + + 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 }, + { "image-policy", required_argument, NULL, ARG_IMAGE_POLICY }, + {} + }; + + 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: { + _cleanup_free_ char *j = NULL; + + j = strjoin("vz-", optarg); + if (!j) + return log_oom(); + + if (!ifname_valid(j)) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), + "Network zone name not valid: %s", j); + + 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: + r = interface_pair_parse(&arg_network_interfaces, optarg); + if (r < 0) + return r; + + arg_private_network = true; + arg_settings_mask |= SETTING_NETWORK; + break; + + case ARG_NETWORK_MACVLAN: + r = macvlan_pair_parse(&arg_network_macvlan, optarg); + if (r < 0) + return r; + + arg_private_network = true; + arg_settings_mask |= SETTING_NETWORK; + break; + + case ARG_NETWORK_IPVLAN: + r = ipvlan_pair_parse(&arg_network_ipvlan, optarg); + if (r < 0) + return r; + + _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 = id128_from_string_nonzero(optarg, &arg_uuid); + if (r == -ENXIO) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), + "Machine UUID may not be all zeroes."); + if (r < 0) + return log_error_errno(r, "Invalid UUID: %s", optarg); + + 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")) { + /* identity: 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 128-bit 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: + r = machine_credential_set(&arg_credentials, &arg_n_credentials, optarg); + if (r < 0) + return r; + + arg_settings_mask |= SETTING_CREDENTIALS; + break; + + case ARG_LOAD_CREDENTIAL: + r = machine_credential_load(&arg_credentials, &arg_n_credentials, optarg); + if (r < 0) + return r; + + 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 ARG_IMAGE_POLICY: + r = parse_image_policy_argument(optarg, &arg_image_policy); + if (r < 0) + return r; + 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."); + + /* Permit --ephemeral with --link-journal=try-* to satisfy principle of the least astonishment + * (by common sense, "try" means "do not fail if not possible") */ + if (arg_ephemeral && !IN_SET(arg_link_journal, LINK_NO, LINK_AUTO) && !arg_link_journal_try) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "--ephemeral and --link-journal={host,guest} 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; +} + +static int verify_network_interfaces_initialized(void) { + int r; + r = test_network_interfaces_initialized(arg_network_interfaces); + if (r < 0) + return r; + + r = test_network_interfaces_initialized(arg_network_macvlan); + if (r < 0) + return r; + + r = test_network_interfaces_initialized(arg_network_ipvlan); + 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("/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(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(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, 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 = bus_get_property_string(bus, bus_resolve_mgr, "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("/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(where, dest, CHASE_NONEXISTENT|CHASE_NOFOLLOW, &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, COPY_REFLINK|COPY_REPLACE); + else + r = copy_file(what, where, O_TRUNC|O_NOFOLLOW, 0644, 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); + 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"; + + 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 = -EBADF; + 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 = -EBADF; + + 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); + 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 fd_inner_socket) { + _cleanup_(unlink_and_freep) char *from = NULL; + _cleanup_free_ char *fifo = NULL; + _cleanup_close_ int fd = -EBADF; + int r; + + assert(fd_inner_socket >= 0); + + BLOCK_WITH_UMASK(0000); + + /* We create the kmsg FIFO as a 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(fd_inner_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 mount_tunnel_dig(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, NSPAWN_MOUNT_TUNNEL, 0600, 0, 0); + if (r < 0) + return log_error_errno(r, "Failed to create "NSPAWN_MOUNT_TUNNEL": %m"); + + q = prefix_roota(root, NSPAWN_MOUNT_TUNNEL); + 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; + + return 0; +} + +static int mount_tunnel_open(void) { + int r; + + r = mount_follow_verbose(LOG_ERR, NULL, NSPAWN_MOUNT_TUNNEL, NULL, MS_SLAVE, NULL); + if (r < 0) + return r; + + return 0; +} + +static int setup_machine_id(const char *directory) { + 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). */ + + r = id128_get_machine(directory, &arg_uuid); + if (ERRNO_IS_NEG_MACHINE_ID_UNSET(r)) { + /* If the file is missing, empty, or uninitialized, we don't mind */ + 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 (r < 0) + return log_error_errno(r, "Failed to read machine ID from container image: %m"); + + 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; + + r = path_extract_filename(arg_image, &arg_machine); + if (r < 0) + return log_error_errno(r, "Failed to extract file name from '%s': %m", arg_image); + + /* Truncate suffix if there is one */ + e = endswith(arg_machine, ".raw"); + if (e) + *e = 0; + } else { + r = path_extract_filename(arg_directory, &arg_machine); + if (r < 0) + return log_error_errno(r, "Failed to extract file name from '%s': %m", arg_directory); + } + + 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_and_update(char **p, unsigned flags) { + char *chased; + int r; + + assert(p); + + if (!*p) + return 0; + + r = chase(*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, + int fd_inner_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(fd_inner_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(fd_inner_socket); + if (r < 0) + return r; + + 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(fd_inner_socket); + if (r < 0) + return r; + } + + if (arg_console_mode != CONSOLE_PIPE) { + _cleanup_close_ int master = -EBADF; + _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(fd_inner_socket, master, 0); + if (r < 0) + return log_error_errno(r, "Failed to send master fd: %m"); + + 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"); +#ifdef ARCHITECTURE_SECONDARY + } else if (arg_architecture == ARCHITECTURE_SECONDARY) { + r = safe_personality(PER_LINUX32); + if (r < 0) + return log_error_errno(r, "personality() failed: %m"); +#endif + } else if (!arg_quiet && arg_architecture >= 0 && arg_architecture != native_architecture()) + log_notice("Selected architecture '%s' not supported natively on the local CPU, assuming " + "invocation with qemu userspace emulator (or equivalent) in effect.", + architecture_to_string(arg_architecture)); + + 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_NEG_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 ?: "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 = -EBADF; + 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, + int fd_outer_socket, + int fd_inner_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 = -EBADF, mntns_fd = -EBADF; + 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(fd_outer_socket >= 0); + assert(fd_inner_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, + /* userns_fd= */ -EBADF, + 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) { + r = namespace_open(0, NULL, &mntns_fd, NULL, NULL, NULL); + if (r < 0) + return log_error_errno(r, "Failed to pin outer mount namespace: %m"); + + l = send_one_fd(fd_outer_socket, mntns_fd, 0); + if (l < 0) + return log_error_errno(l, "Failed to send outer mount namespace fd: %m"); + mntns_fd = safe_close(mntns_fd); + + /* Let the parent know which UID shift we read from the image */ + l = send(fd_outer_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(fd_outer_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 namespace 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"; + } + + /* 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; + + /* So the whole tree is now MS_SLAVE, i.e. we'll still receive mount/umount events from the host + * mount namespace. For the directory we are going to run our container let's turn this off, so that + * we'll live in our own little world from now on, and propagation from the host may only happen via + * the mount tunnel dir, or not at all. */ + r = mount_follow_verbose(LOG_ERR, NULL, directory, NULL, MS_PRIVATE|MS_REC, NULL); + if (r < 0) + return r; + + 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(fd_outer_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; + + if (arg_userns_mode != USER_NAMESPACE_NO && + IN_SET(arg_userns_ownership, USER_NAMESPACE_OWNERSHIP_MAP, USER_NAMESPACE_OWNERSHIP_AUTO) && + arg_uid_shift != 0) { + _cleanup_free_ char *usr_subtree = NULL; + char *dirs[3]; + size_t i = 0; + + dirs[i++] = (char*) directory; + + if (dissected_image && dissected_image->partitions[PARTITION_USR].found) { + usr_subtree = path_join(directory, "/usr"); + if (!usr_subtree) + return log_oom(); + + dirs[i++] = usr_subtree; + } + + dirs[i] = NULL; + + r = remount_idmap(dirs, arg_uid_shift, arg_uid_range, UID_INVALID, REMOUNT_IDMAPPING_HOST_ROOT); + if (r == -EINVAL || ERRNO_IS_NEG_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, + /* userns_fd= */ -EBADF, + 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(fd_outer_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."); + } + + 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 = mount_tunnel_dig(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; + } + + /* 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_switch_root(directory, MS_SHARED); + if (r < 0) + return log_error_errno(r, "Failed to move root directory: %m"); + + /* We finished setting up the rootfs which is a shared mount. The mount tunnel needs to be a + * dependent mount otherwise we can't MS_MOVE mounts that were propagated from the host into + * the container. */ + r = mount_tunnel_open(); + if (r < 0) + return r; + + if (arg_userns_mode != USER_NAMESPACE_NO) { + /* In order to mount procfs and sysfs in an unprivileged container the kernel + * requires that a fully visible instance is already present in the target mount + * namespace. Mount one here so the inner child can mount its own instances. Later + * we umount the temporary instances created here before we actually exec the + * payload. Since the rootfs is shared the umount will propagate into the container. + * Note, the inner child wouldn't be able to unmount the instances on its own since + * it doesn't own the originating mount namespace. IOW, the outer child needs to do + * this. */ + r = pin_fully_visible_fs(); + if (r < 0) + return r; + } + + 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) { + fd_outer_socket = safe_close(fd_outer_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, fd_inner_socket, fds, os_release_pairs); + if (r < 0) + _exit(EXIT_FAILURE); + + _exit(EXIT_SUCCESS); + } + + l = send(fd_outer_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(fd_outer_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(fd_outer_socket, fd, 0); + if (l < 0) + return log_error_errno(l, "Failed to send notify fd: %m"); + + fd_outer_socket = safe_close(fd_outer_socket); + fd_inner_socket = safe_close(fd_inner_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 (ERRNO_IS_NEG_TRANSIENT(n)) + return 0; + else if (n == -EXFULL) { + log_warning("Got message with truncated control data (too many fds sent?), ignoring."); + return 0; + } else if (n < 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 = TAKE_STRUCT(settings->cpu_set); + } + } + + 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) { + r = file_in_same_dir(arg_image, arg_settings_filename, &p); + if (r < 0) + return log_error_errno(r, "Failed to generate settings path from image path: %m"); + } else if (arg_directory) { + r = file_in_same_dir(arg_directory, arg_settings_filename, &p); + if (r < 0 && r != -EADDRNOTAVAIL) /* if directory is root fs, don't complain */ + return log_error_errno(r, "Failed to generate settings path from directory path: %m"); + } + + 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, + 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 = -EBADF; + _cleanup_close_pair_ int + fd_inner_socket_pair[2] = EBADF_PAIR, + fd_outer_socket_pair[2] = EBADF_PAIR; + + _cleanup_close_ int notify_socket = -EBADF, mntns_fd = -EBADF, fd_kmsg_fifo = -EBADF; + _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 = -EBADF; + + 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, fd_inner_socket_pair) < 0) + return log_error_errno(errno, "Failed to create inner socket pair: %m"); + + if (socketpair(AF_UNIX, SOCK_SEQPACKET|SOCK_CLOEXEC, 0, fd_outer_socket_pair) < 0) + return log_error_errno(errno, "Failed to create outer 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); + + fd_inner_socket_pair[0] = safe_close(fd_inner_socket_pair[0]); + fd_outer_socket_pair[0] = safe_close(fd_outer_socket_pair[0]); + + (void) reset_all_signal_handlers(); + (void) reset_signal_mask(); + + r = outer_child(&barrier, + arg_directory, + dissected_image, + fd_outer_socket_pair[1], + fd_inner_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); + + fd_inner_socket_pair[1] = safe_close(fd_inner_socket_pair[1]); + fd_outer_socket_pair[1] = safe_close(fd_outer_socket_pair[1]); + + if (arg_userns_mode != USER_NAMESPACE_NO) { + mntns_fd = receive_one_fd(fd_outer_socket_pair[0], 0); + if (mntns_fd < 0) + return log_error_errno(mntns_fd, "Failed to receive mount namespace fd from outer child: %m"); + + /* The child just let us know the UID shift it might have read from the image. */ + l = recv(fd_outer_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(fd_outer_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(fd_outer_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(fd_outer_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(fd_outer_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(fd_outer_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(fd_outer_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, &arg_network_provided_mac); + 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, + arg_start_mode); + 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, + /* allow_pidfds= */ true, + arg_start_mode); + 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; + + /* Wait that the child is completely ready now, and has mounted their own copies of procfs and so on, + * before we take the fully visible instances away. */ + if (!barrier_sync(&barrier)) /* #5.1 */ + return log_error_errno(SYNTHETIC_ERRNO(ESRCH), "Child died too early."); + + if (arg_userns_mode != USER_NAMESPACE_NO) { + r = wipe_fully_visible_fs(mntns_fd); + if (r < 0) + return r; + mntns_fd = safe_close(mntns_fd); + } + + /* And now let the child know that we completed removing the procfs instances, and it can start the + * payload. */ + if (!barrier_place(&barrier)) /* #5.2 */ + 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); + } + + (void) sd_event_add_signal(event, NULL, SIGRTMIN+18, sigrtmin18_handler, NULL); + + r = sd_event_add_memory_pressure(event, NULL, NULL, NULL); + if (r < 0) + log_debug_errno(r, "Failed allocate memory pressure event source, ignoring: %m"); + + /* Exit when the child exits */ + (void) sd_event_add_signal(event, NULL, SIGCHLD, on_sigchld, PID_TO_PTR(*pid)); + + /* Retrieve the kmsg fifo allocated by inner child */ + fd_kmsg_fifo = receive_one_fd(fd_inner_socket_pair[0], 0); + if (fd_kmsg_fifo < 0) + return log_error_errno(fd_kmsg_fifo, "Failed to receive kmsg fifo from inner child: %m"); + + if (arg_expose_ports) { + r = expose_port_watch_rtnl(event, fd_inner_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); + } + + if (arg_console_mode != CONSOLE_PIPE) { + _cleanup_close_ int fd = -EBADF; + PTYForwardFlags flags = 0; + + /* Retrieve the master pty allocated by inner child */ + fd = receive_one_fd(fd_inner_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); + } + + fd_inner_socket_pair[0] = safe_close(fd_inner_socket_pair[0]); + + 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); + + fd_kmsg_fifo = safe_close(fd_kmsg_fifo); + + 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_SIGTERM|FORK_WAIT|FORK_LOG, NULL); + if (r < 0) + return r; + + if (r == 0) { + _cleanup_close_ int parent_netns_fd = -EBADF; + + r = namespace_open(getpid_cached(), 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); + } + + /* Reverse network interfaces pair list so that interfaces get their initial name back. + * This is about ensuring interfaces get their old name back when being moved back. */ + arg_network_interfaces = strv_reverse(arg_network_interfaces); + + 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 = -EBADF; + 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 == -ENOENT || ERRNO_IS_NEG_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."); + if (r < 0) + 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 remove_directory = false, remove_image = false, veth_created = false, remove_tmprootdir = false; + _cleanup_close_ int master = -EBADF; + _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; + + r = verify_network_interfaces_initialized(); + 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))) { + r = log_error_errno(SYNTHETIC_ERRNO(EINVAL), + "Spawning container on root directory is not supported. Consider using --ephemeral, --volatile=yes or --volatile=state."); + goto finish; + } + + if (arg_ephemeral) { + _cleanup_free_ char *np = NULL; + + r = chase_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_at(AT_FDCWD, arg_directory, AT_FDCWD, 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_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_and_update(&arg_template, 0); + if (r < 0) + goto finish; + + { + BLOCK_SIGNALS(SIGINT); + r = btrfs_subvol_snapshot_at(AT_FDCWD, arg_template, AT_FDCWD, 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; + int check_os_release, is_os_tree; + + 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; + + check_os_release = getenv_bool("SYSTEMD_NSPAWN_CHECK_OS_RELEASE"); + if (check_os_release < 0 && check_os_release != -ENXIO) { + r = log_error_errno(check_os_release, "Failed to parse $SYSTEMD_NSPAWN_CHECK_OS_RELEASE: %m"); + goto finish; + } + + is_os_tree = path_is_os_tree(p); + if (is_os_tree == 0 && check_os_release == 0) + log_debug("Directory %s is missing an os-release file, continuing anyway.", p); + else if (is_os_tree <= 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_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_full(arg_image, np, O_EXCL, arg_read_only ? 0400 : 0600, + FS_NOCOW_FL, FS_NOCOW_FL, + COPY_REFLINK|COPY_CRTIME|COPY_SIGINT, + NULL, NULL); + } + 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, + /* sector_size= */ UINT32_MAX, + 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, + /* mount_options=*/ NULL, + arg_image_policy ?: &image_policy_container, + 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://uapi-group.org/specifications/specs/discoverable_partitions_specification\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; + + if (arg_architecture < 0) + arg_architecture = dissected_image_architecture(dissected_image); + } + + 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 Ctrl-] three times within 1s to kill container.", + arg_machine, arg_image ?: arg_directory); + + assert_se(sigprocmask_many(SIG_BLOCK, NULL, SIGCHLD, SIGWINCH, SIGTERM, SIGINT, SIGRTMIN+18, -1) >= 0); + + r = make_reaper_process(true); + if (r < 0) { + log_error_errno(r, "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, + 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); + machine_credential_free_all(arg_credentials, arg_n_credentials); + + if (r < 0) + return r; + + return ret; +} + +DEFINE_MAIN_FUNCTION_WITH_POSITIVE_FAILURE(run); |