diff options
Diffstat (limited to 'src/systemd-nspawn/nspawn.c')
| -rw-r--r-- | src/systemd-nspawn/nspawn.c | 4319 |
1 files changed, 4319 insertions, 0 deletions
diff --git a/src/systemd-nspawn/nspawn.c b/src/systemd-nspawn/nspawn.c new file mode 100644 index 0000000000..5a3624fad1 --- /dev/null +++ b/src/systemd-nspawn/nspawn.c @@ -0,0 +1,4319 @@ +/*** + This file is part of systemd. + + Copyright 2010 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#ifdef HAVE_BLKID +#include <blkid/blkid.h> +#endif +#include <errno.h> +#include <getopt.h> +#include <grp.h> +#include <pwd.h> +#include <sched.h> + +#include <linux/loop.h> +#ifdef HAVE_SELINUX +#include <selinux/selinux.h> +#endif +#include <signal.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/file.h> +#include <sys/mount.h> +#include <sys/personality.h> +#include <sys/prctl.h> +#include <sys/types.h> +#include <unistd.h> + +#include <systemd/sd-daemon.h> +#include <systemd/sd-id128.h> + +#include "core/loopback-setup.h" +#include "sd-id128/id128-util.h" +#include "sd-netlink/netlink-util.h" +#include "systemd-basic/alloc-util.h" +#include "systemd-basic/barrier.h" +#include "systemd-basic/btrfs-util.h" +#include "systemd-basic/cap-list.h" +#include "systemd-basic/capability-util.h" +#include "systemd-basic/cgroup-util.h" +#include "systemd-basic/copy.h" +#include "systemd-basic/env-util.h" +#include "systemd-basic/fd-util.h" +#include "systemd-basic/fileio.h" +#include "systemd-basic/formats-util.h" +#include "systemd-basic/fs-util.h" +#include "systemd-basic/hostname-util.h" +#include "systemd-basic/log.h" +#include "systemd-basic/macro.h" +#include "systemd-basic/missing.h" +#include "systemd-basic/mkdir.h" +#include "systemd-basic/mount-util.h" +#include "systemd-basic/parse-util.h" +#include "systemd-basic/path-util.h" +#include "systemd-basic/process-util.h" +#include "systemd-basic/random-util.h" +#include "systemd-basic/raw-clone.h" +#include "systemd-basic/rm-rf.h" +#include "systemd-basic/selinux-util.h" +#include "systemd-basic/signal-util.h" +#include "systemd-basic/socket-util.h" +#include "systemd-basic/stat-util.h" +#include "systemd-basic/stdio-util.h" +#include "systemd-basic/string-util.h" +#include "systemd-basic/strv.h" +#include "systemd-basic/terminal-util.h" +#include "systemd-basic/umask-util.h" +#include "systemd-basic/user-util.h" +#include "systemd-basic/util.h" +#include "systemd-blkid/blkid-util.h" +#include "systemd-shared/base-filesystem.h" +#include "systemd-shared/dev-setup.h" +#include "systemd-shared/fdset.h" +#include "systemd-shared/gpt.h" +#include "systemd-shared/machine-image.h" +#include "systemd-shared/ptyfwd.h" +#include "systemd-shared/udev-util.h" + +#include "nspawn-cgroup.h" +#include "nspawn-expose-ports.h" +#include "nspawn-mount.h" +#include "nspawn-network.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" + +/* Note that devpts's gid= parameter parses GIDs as signed values, hence we stay away from the upper half of the 32bit + * UID range here. We leave a bit of room at the lower end and a lot of room at the upper end, so that other subsystems + * may have their own allocation ranges too. */ +#define UID_SHIFT_PICK_MIN ((uid_t) UINT32_C(0x00080000)) +#define UID_SHIFT_PICK_MAX ((uid_t) UINT32_C(0x6FFF0000)) + +/* nspawn is listening on the socket at the path in the constant nspawn_notify_socket_path + * nspawn_notify_socket_path is relative to the container + * the init process in the container pid can send messages to nspawn following the sd_notify(3) protocol */ +#define NSPAWN_NOTIFY_SOCKET_PATH "/run/systemd/nspawn/notify" + +typedef enum ContainerStatus { + CONTAINER_TERMINATED, + CONTAINER_REBOOTED +} ContainerStatus; + +typedef enum LinkJournal { + LINK_NO, + LINK_AUTO, + LINK_HOST, + LINK_GUEST +} LinkJournal; + +static char *arg_directory = NULL; +static char *arg_template = NULL; +static char *arg_chdir = NULL; +static char *arg_user = NULL; +static sd_id128_t arg_uuid = {}; +static char *arg_machine = NULL; +static const char *arg_selinux_context = NULL; +static const char *arg_selinux_apifs_context = NULL; +static const 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 CustomMount *arg_custom_mounts = NULL; +static unsigned 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 unsigned long arg_personality = PERSONALITY_INVALID; +static char *arg_image = NULL; +static VolatileMode arg_volatile_mode = VOLATILE_NO; +static ExposePort *arg_expose_ports = NULL; +static char **arg_property = NULL; +static UserNamespaceMode arg_userns_mode = USER_NAMESPACE_NO; +static uid_t arg_uid_shift = UID_INVALID, arg_uid_range = 0x10000U; +static bool arg_userns_chown = false; +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 void help(void) { + printf("%s [OPTIONS...] [PATH] [ARGUMENTS...]\n\n" + "Spawn a minimal namespace container for debugging, testing and building.\n\n" + " -h --help Show this help\n" + " --version Print version string\n" + " -q --quiet Do not show status information\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 File system device or disk image for the container\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" + " -u --user=USER Run the command under specified user or uid\n" + " -M --machine=NAME Set the machine name for the container\n" + " --uuid=UUID Set a specific machine UUID for the container\n" + " -S --slice=SLICE Place the container in the specified slice\n" + " --property=NAME=VALUE Set scope unit property\n" + " -U --private-users=pick 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-chown Adjust OS tree ownership to private UID/GID range\n" + " --private-network Disable network in container\n" + " --network-interface=INTERFACE\n" + " Assign an existing network interface to the\n" + " container\n" + " --network-macvlan=INTERFACE\n" + " Create a macvlan network interface based on an\n" + " existing network interface to the container\n" + " --network-ipvlan=INTERFACE\n" + " Create a 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" + " -p --port=[PROTOCOL:]HOSTPORT[:CONTAINERPORT]\n" + " Expose a container IP port on the host\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" + " --capability=CAP In addition to the default, retain specified\n" + " capability\n" + " --drop-capability=CAP Drop the specified capability from the default set\n" + " --kill-signal=SIGNAL Select signal to use for shutting down PID 1\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" + " --read-only Mount the root directory read-only\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" + " --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" + " -E --setenv=NAME=VALUE Pass an environment variable to PID 1\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" + " --volatile[=MODE] Run the system in volatile mode\n" + " --settings=BOOLEAN Load additional settings from .nspawn file\n" + " --notify-ready=BOOLEAN Receive notifications from the child init process\n" + , program_invocation_short_name); +} + +static int custom_mounts_prepare(void) { + unsigned i; + int r; + + /* Ensure the mounts are applied prefix first. */ + qsort_safe(arg_custom_mounts, arg_n_custom_mounts, sizeof(CustomMount), custom_mount_compare); + + /* Allocate working directories for the overlay file systems that need it */ + 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_chown) { + log_error("--private-users-chown may not be combined with custom root mounts."); + return -EINVAL; + } else if (arg_uid_shift == UID_INVALID) { + log_error("--private-users with automatic UID shift may not be combined with custom root mounts."); + return -EINVAL; + } + } + + if (m->type != CUSTOM_MOUNT_OVERLAY) + continue; + + if (m->work_dir) + continue; + + if (m->read_only) + continue; + + r = tempfn_random(m->source, NULL, &m->work_dir); + if (r < 0) + return log_error_errno(r, "Failed to generate work directory from %s: %m", m->source); + } + + return 0; +} + +static int detect_unified_cgroup_hierarchy(const char *directory) { + const char *e; + int r, all_unified, systemd_unified; + + /* Allow the user to control whether the unified hierarchy is used */ + e = getenv("UNIFIED_CGROUP_HIERARCHY"); + if (e) { + r = parse_boolean(e); + if (r < 0) + return log_error_errno(r, "Failed to parse $UNIFIED_CGROUP_HIERARCHY."); + if (r > 0) + arg_unified_cgroup_hierarchy = CGROUP_UNIFIED_ALL; + else + arg_unified_cgroup_hierarchy = CGROUP_UNIFIED_NONE; + + return 0; + } + + all_unified = cg_all_unified(); + systemd_unified = cg_unified(SYSTEMD_CGROUP_CONTROLLER); + + if (all_unified < 0 || systemd_unified < 0) + return log_error_errno(all_unified < 0 ? all_unified : systemd_unified, + "Failed to determine whether the unified cgroups hierarchy is used: %m"); + + /* Otherwise inherit the default from the host system */ + if (all_unified > 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 (systemd_unified > 0) { + /* Mixed cgroup hierarchy support was added in 232 */ + r = systemd_installation_has_version(directory, 232); + 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; + + return 0; +} + +static void parse_share_ns_env(const char *name, unsigned long ns_flag) { + int r; + + r = getenv_bool(name); + if (r == -ENXIO) + return; + if (r < 0) + log_warning_errno(r, "Failed to parse %s from environment, defaulting to false.", name); + arg_clone_ns_flags = (arg_clone_ns_flags & ~ns_flag) | (r > 0 ? 0 : ns_flag); +} + +static int parse_argv(int argc, char *argv[]) { + + enum { + ARG_VERSION = 0x100, + ARG_PRIVATE_NETWORK, + ARG_UUID, + ARG_READ_ONLY, + ARG_CAPABILITY, + ARG_DROP_CAPABILITY, + ARG_LINK_JOURNAL, + ARG_BIND, + ARG_BIND_RO, + ARG_TMPFS, + ARG_OVERLAY, + ARG_OVERLAY_RO, + 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_PERSONALITY, + ARG_VOLATILE, + ARG_TEMPLATE, + ARG_PROPERTY, + ARG_PRIVATE_USERS, + ARG_KILL_SIGNAL, + ARG_SETTINGS, + ARG_CHDIR, + ARG_PRIVATE_USERS_CHOWN, + ARG_NOTIFY_READY, + }; + + 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 }, + { "drop-capability", required_argument, NULL, ARG_DROP_CAPABILITY }, + { "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 }, + { "machine", required_argument, NULL, 'M' }, + { "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 }, + { "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 }, + { "kill-signal", required_argument, NULL, ARG_KILL_SIGNAL }, + { "settings", required_argument, NULL, ARG_SETTINGS }, + { "chdir", required_argument, NULL, ARG_CHDIR }, + { "notify-ready", required_argument, NULL, ARG_NOTIFY_READY }, + {} + }; + + int c, r; + const char *p, *e; + uint64_t plus = 0, minus = 0; + bool mask_all_settings = false, mask_no_settings = false; + + assert(argc >= 0); + assert(argv); + + while ((c = getopt_long(argc, argv, "+hD:u:abL:M:jS:Z:qi:xp:nU", options, NULL)) >= 0) + + switch (c) { + + case 'h': + help(); + return 0; + + case ARG_VERSION: + return version(); + + case 'D': + r = parse_path_argument_and_warn(optarg, false, &arg_directory); + if (r < 0) + return r; + break; + + case ARG_TEMPLATE: + r = parse_path_argument_and_warn(optarg, false, &arg_template); + if (r < 0) + return r; + break; + + case 'i': + r = parse_path_argument_and_warn(optarg, false, &arg_image); + if (r < 0) + return r; + break; + + case 'x': + arg_ephemeral = true; + break; + + case 'u': + r = free_and_strdup(&arg_user, optarg); + if (r < 0) + return log_oom(); + + arg_settings_mask |= SETTING_USER; + break; + + case ARG_NETWORK_ZONE: { + char *j; + + j = strappend("vz-", optarg); + if (!j) + return log_oom(); + + if (!ifname_valid(j)) { + log_error("Network zone name not valid: %s", j); + free(j); + return -EINVAL; + } + + free(arg_network_zone); + 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)) { + log_error("Bridge interface name not valid: %s", optarg); + return -EINVAL; + } + + r = free_and_strdup(&arg_network_bridge, optarg); + if (r < 0) + return log_oom(); + + /* fall through */ + + case 'n': + arg_network_veth = true; + arg_private_network = true; + arg_settings_mask |= SETTING_NETWORK; + break; + + case ARG_NETWORK_VETH_EXTRA: + r = veth_extra_parse(&arg_network_veth_extra, optarg); + if (r < 0) + return log_error_errno(r, "Failed to parse --network-veth-extra= parameter: %s", optarg); + + arg_private_network = true; + arg_settings_mask |= SETTING_NETWORK; + break; + + case ARG_NETWORK_INTERFACE: + + if (!ifname_valid(optarg)) { + log_error("Network interface name not valid: %s", optarg); + return -EINVAL; + } + + if (strv_extend(&arg_network_interfaces, optarg) < 0) + return log_oom(); + + arg_private_network = true; + arg_settings_mask |= SETTING_NETWORK; + break; + + case ARG_NETWORK_MACVLAN: + + if (!ifname_valid(optarg)) { + log_error("MACVLAN network interface name not valid: %s", optarg); + return -EINVAL; + } + + if (strv_extend(&arg_network_macvlan, optarg) < 0) + return log_oom(); + + arg_private_network = true; + arg_settings_mask |= SETTING_NETWORK; + break; + + case ARG_NETWORK_IPVLAN: + + if (!ifname_valid(optarg)) { + log_error("IPVLAN network interface name not valid: %s", optarg); + return -EINVAL; + } + + if (strv_extend(&arg_network_ipvlan, optarg) < 0) + return log_oom(); + + /* fall through */ + + case ARG_PRIVATE_NETWORK: + arg_private_network = true; + arg_settings_mask |= SETTING_NETWORK; + break; + + case 'b': + if (arg_start_mode == START_PID2) { + log_error("--boot and --as-pid2 may not be combined."); + return -EINVAL; + } + + arg_start_mode = START_BOOT; + arg_settings_mask |= SETTING_START_MODE; + break; + + case 'a': + if (arg_start_mode == START_BOOT) { + log_error("--boot and --as-pid2 may not be combined."); + return -EINVAL; + } + + arg_start_mode = START_PID2; + arg_settings_mask |= SETTING_START_MODE; + break; + + case ARG_UUID: + r = sd_id128_from_string(optarg, &arg_uuid); + if (r < 0) + return log_error_errno(r, "Invalid UUID: %s", optarg); + + if (sd_id128_is_null(arg_uuid)) { + log_error("Machine UUID may not be all zeroes."); + return -EINVAL; + } + + arg_settings_mask |= SETTING_MACHINE_ID; + break; + + case 'S': + arg_slice = optarg; + break; + + case 'M': + if (isempty(optarg)) + arg_machine = mfree(arg_machine); + else { + if (!machine_name_is_valid(optarg)) { + log_error("Invalid machine name: %s", optarg); + return -EINVAL; + } + + r = free_and_strdup(&arg_machine, optarg); + if (r < 0) + return log_oom(); + + 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_CAPABILITY: + case ARG_DROP_CAPABILITY: { + p = optarg; + for (;;) { + _cleanup_free_ char *t = NULL; + + r = extract_first_word(&p, &t, ",", 0); + if (r < 0) + return log_error_errno(r, "Failed to parse capability %s.", t); + + if (r == 0) + break; + + if (streq(t, "all")) { + if (c == ARG_CAPABILITY) + plus = (uint64_t) -1; + else + minus = (uint64_t) -1; + } else { + int cap; + + cap = capability_from_name(t); + if (cap < 0) { + log_error("Failed to parse capability %s.", t); + return -EINVAL; + } + + if (c == ARG_CAPABILITY) + plus |= 1ULL << (uint64_t) cap; + else + minus |= 1ULL << (uint64_t) cap; + } + } + + arg_settings_mask |= SETTING_CAPABILITY; + break; + } + + case 'j': + arg_link_journal = LINK_GUEST; + arg_link_journal_try = true; + break; + + case ARG_LINK_JOURNAL: + if (streq(optarg, "auto")) { + arg_link_journal = LINK_AUTO; + arg_link_journal_try = false; + } else if (streq(optarg, "no")) { + arg_link_journal = LINK_NO; + arg_link_journal_try = false; + } else if (streq(optarg, "guest")) { + arg_link_journal = LINK_GUEST; + arg_link_journal_try = false; + } else if (streq(optarg, "host")) { + arg_link_journal = LINK_HOST; + arg_link_journal_try = false; + } else if (streq(optarg, "try-guest")) { + arg_link_journal = LINK_GUEST; + arg_link_journal_try = true; + } else if (streq(optarg, "try-host")) { + arg_link_journal = LINK_HOST; + arg_link_journal_try = true; + } else { + log_error("Failed to parse link journal mode %s", optarg); + return -EINVAL; + } + + 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: { + _cleanup_free_ char *upper = NULL, *destination = NULL; + _cleanup_strv_free_ char **lower = NULL; + CustomMount *m; + unsigned n = 0; + char **i; + + r = strv_split_extract(&lower, optarg, ":", EXTRACT_DONT_COALESCE_SEPARATORS); + if (r == -ENOMEM) + return log_oom(); + else if (r < 0) { + log_error("Invalid overlay specification: %s", optarg); + return r; + } + + STRV_FOREACH(i, lower) { + if (!path_is_absolute(*i)) { + log_error("Overlay path %s is not absolute.", *i); + return -EINVAL; + } + + n++; + } + + if (n < 2) { + log_error("--overlay= needs at least two colon-separated directories specified."); + return -EINVAL; + } + + if (n == 2) { + /* If two parameters are specified, + * the first one is the lower, the + * second one the upper directory. And + * we'll also define the destination + * mount point the same as the upper. */ + upper = lower[1]; + lower[1] = NULL; + + destination = strdup(upper); + if (!destination) + return log_oom(); + + } else { + upper = lower[n - 2]; + destination = lower[n - 1]; + lower[n - 2] = NULL; + } + + m = custom_mount_add(&arg_custom_mounts, &arg_n_custom_mounts, CUSTOM_MOUNT_OVERLAY); + if (!m) + return log_oom(); + + m->destination = destination; + m->source = upper; + m->lower = lower; + m->read_only = c == ARG_OVERLAY_RO; + + upper = destination = NULL; + lower = NULL; + + arg_settings_mask |= SETTING_CUSTOM_MOUNTS; + break; + } + + case 'E': { + char **n; + + if (!env_assignment_is_valid(optarg)) { + log_error("Environment variable assignment '%s' is not valid.", optarg); + return -EINVAL; + } + + n = strv_env_set(arg_setenv, optarg); + if (!n) + return log_oom(); + + strv_free(arg_setenv); + arg_setenv = n; + + 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. */ + 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) { + log_error("Unknown or unsupported personality '%s'.", optarg); + return -EINVAL; + } + + arg_settings_mask |= SETTING_PERSONALITY; + break; + + case ARG_VOLATILE: + + if (!optarg) + arg_volatile_mode = VOLATILE_YES; + else { + VolatileMode m; + + m = volatile_mode_from_string(optarg); + if (m < 0) { + log_error("Failed to parse --volatile= argument: %s", optarg); + return -EINVAL; + } 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 = -1; + + if (!optarg) + boolean = true; + else if (!in_charset(optarg, DIGITS)) + /* do *not* parse numbers as booleans */ + boolean = parse_boolean(optarg); + + if (boolean == false) { + /* no: User namespacing off */ + arg_userns_mode = USER_NAMESPACE_NO; + arg_uid_shift = UID_INVALID; + arg_uid_range = UINT32_C(0x10000); + } else if (boolean == true) { + /* 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; + arg_uid_shift = UID_INVALID; + 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 (arg_uid_range <= 0) { + log_error("UID range cannot be 0."); + return -EINVAL; + } + + arg_settings_mask |= SETTING_USERNS; + break; + } + + case 'U': + if (userns_supported()) { + arg_userns_mode = USER_NAMESPACE_PICK; + arg_uid_shift = UID_INVALID; + arg_uid_range = UINT32_C(0x10000); + + arg_settings_mask |= SETTING_USERNS; + } + + break; + + case ARG_PRIVATE_USERS_CHOWN: + arg_userns_chown = true; + + arg_settings_mask |= SETTING_USERNS; + break; + + case ARG_KILL_SIGNAL: + arg_kill_signal = signal_from_string_try_harder(optarg); + if (arg_kill_signal < 0) { + log_error("Cannot parse signal: %s", optarg); + return -EINVAL; + } + + 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)) { + log_error("Working directory %s is not an absolute path.", optarg); + return -EINVAL; + } + + r = free_and_strdup(&arg_chdir, optarg); + if (r < 0) + return log_oom(); + + arg_settings_mask |= SETTING_WORKING_DIRECTORY; + break; + + case ARG_NOTIFY_READY: + r = parse_boolean(optarg); + if (r < 0) { + log_error("%s is not a valid notify mode. Valid modes are: yes, no, and ready.", optarg); + return -EINVAL; + } + arg_notify_ready = r; + arg_settings_mask |= SETTING_NOTIFY_READY; + break; + + case '?': + return -EINVAL; + + default: + assert_not_reached("Unhandled option"); + } + + parse_share_ns_env("SYSTEMD_NSPAWN_SHARE_NS_IPC", CLONE_NEWIPC); + parse_share_ns_env("SYSTEMD_NSPAWN_SHARE_NS_PID", CLONE_NEWPID); + parse_share_ns_env("SYSTEMD_NSPAWN_SHARE_NS_UTS", CLONE_NEWUTS); + parse_share_ns_env("SYSTEMD_NSPAWN_SHARE_SYSTEM", CLONE_NEWIPC|CLONE_NEWPID|CLONE_NEWUTS); + + if (!(arg_clone_ns_flags & CLONE_NEWPID) || + !(arg_clone_ns_flags & CLONE_NEWUTS)) { + arg_register = false; + if (arg_start_mode != START_PID1) { + log_error("--boot cannot be used without namespacing."); + return -EINVAL; + } + } + + if (arg_userns_mode == USER_NAMESPACE_PICK) + arg_userns_chown = true; + + if (arg_keep_unit && cg_pid_get_owner_uid(0, NULL) >= 0) { + log_error("--keep-unit may not be used when invoked from a user session."); + return -EINVAL; + } + + if (arg_directory && arg_image) { + log_error("--directory= and --image= may not be combined."); + return -EINVAL; + } + + if (arg_template && arg_image) { + log_error("--template= and --image= may not be combined."); + return -EINVAL; + } + + if (arg_template && !(arg_directory || arg_machine)) { + log_error("--template= needs --directory= or --machine=."); + return -EINVAL; + } + + if (arg_ephemeral && arg_template) { + log_error("--ephemeral and --template= may not be combined."); + return -EINVAL; + } + + if (arg_ephemeral && arg_image) { + log_error("--ephemeral and --image= may not be combined."); + return -EINVAL; + } + + if (arg_ephemeral && !IN_SET(arg_link_journal, LINK_NO, LINK_AUTO)) { + log_error("--ephemeral and --link-journal= may not be combined."); + return -EINVAL; + } + + if (arg_userns_mode != USER_NAMESPACE_NO && !userns_supported()) { + log_error("--private-users= is not supported, kernel compiled without user namespace support."); + return -EOPNOTSUPP; + } + + if (arg_userns_chown && arg_read_only) { + log_error("--read-only and --private-users-chown may not be combined."); + return -EINVAL; + } + + if (arg_network_bridge && arg_network_zone) { + log_error("--network-bridge= and --network-zone= may not be combined."); + return -EINVAL; + } + + if (argc > optind) { + arg_parameters = strv_copy(argv + optind); + if (!arg_parameters) + return log_oom(); + + arg_settings_mask |= SETTING_START_MODE; + } + + /* 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; + + arg_caps_retain = (arg_caps_retain | plus | (arg_private_network ? 1ULL << CAP_NET_ADMIN : 0)) & ~minus; + + e = getenv("SYSTEMD_NSPAWN_CONTAINER_SERVICE"); + if (e) + arg_container_service_name = e; + + r = getenv_bool("SYSTEMD_NSPAWN_USE_CGNS"); + if (r < 0) + arg_use_cgns = cg_ns_supported(); + else + arg_use_cgns = r; + + return 1; +} + +static int verify_arguments(void) { + + if (arg_volatile_mode != VOLATILE_NO && arg_read_only) { + log_error("Cannot combine --read-only with --volatile. Note that --volatile already implies a read-only base hierarchy."); + return -EINVAL; + } + + if (arg_expose_ports && !arg_private_network) { + log_error("Cannot use --port= without private networking."); + return -EINVAL; + } + +#ifndef HAVE_LIBIPTC + if (arg_expose_ports) { + log_error("--port= is not supported, compiled without libiptc support."); + return -EOPNOTSUPP; + } +#endif + + if (arg_start_mode == START_BOOT && arg_kill_signal <= 0) + arg_kill_signal = SIGRTMIN+3; + + return 0; +} + +static 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; + } + + if (lchown(p, uid, gid) < 0) + return -errno; + + return 0; +} + +static int userns_mkdir(const char *root, const char *path, mode_t mode, uid_t uid, gid_t gid) { + const char *q; + + q = prefix_roota(root, path); + if (mkdir(q, mode) < 0) { + if (errno == EEXIST) + return 0; + return -errno; + } + + return userns_lchown(q, uid, gid); +} + +static int setup_timezone(const char *dest) { + _cleanup_free_ char *p = NULL, *q = NULL; + const char *where, *check, *what; + char *z, *y; + int r; + + assert(dest); + + /* Fix the timezone, if possible */ + r = readlink_malloc("/etc/localtime", &p); + if (r < 0) { + log_warning("host's /etc/localtime is not a symlink, not updating container timezone."); + /* 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; + } + + z = path_startswith(p, "../usr/share/zoneinfo/"); + if (!z) + z = path_startswith(p, "/usr/share/zoneinfo/"); + if (!z) { + log_warning("/etc/localtime does not point into /usr/share/zoneinfo/, not updating container timezone."); + return 0; + } + + where = prefix_roota(dest, "/etc/localtime"); + r = readlink_malloc(where, &q); + if (r >= 0) { + y = path_startswith(q, "../usr/share/zoneinfo/"); + if (!y) + y = path_startswith(q, "/usr/share/zoneinfo/"); + + /* Already pointing to the right place? Then do nothing .. */ + if (y && streq(y, z)) + return 0; + } + + check = strjoina("/usr/share/zoneinfo/", z); + check = prefix_roota(dest, check); + if (laccess(check, F_OK) < 0) { + log_warning("Timezone %s does not exist in container, not updating container timezone.", z); + return 0; + } + + r = unlink(where); + if (r < 0 && errno != ENOENT) { + log_error_errno(errno, "Failed to remove existing timezone info %s in container: %m", where); + return 0; + } + + what = strjoina("../usr/share/zoneinfo/", z); + if (symlink(what, where) < 0) { + log_error_errno(errno, "Failed to correct timezone of container: %m"); + return 0; + } + + r = userns_lchown(where, 0, 0); + if (r < 0) + return log_warning_errno(r, "Failed to chown /etc/localtime: %m"); + + return 0; +} + +static int setup_resolv_conf(const char *dest) { + const char *where = NULL; + int r; + + assert(dest); + + if (arg_private_network) + return 0; + + /* Fix resolv.conf, if possible */ + where = prefix_roota(dest, "/etc/resolv.conf"); + + r = copy_file("/etc/resolv.conf", where, O_TRUNC|O_NOFOLLOW, 0644, 0); + 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(r, -ELOOP, -EROFS) ? LOG_DEBUG : LOG_WARNING, r, + "Failed to copy /etc/resolv.conf to %s: %m", where); + return 0; + } + + r = userns_lchown(where, 0, 0); + if (r < 0) + log_warning_errno(r, "Failed to chown /etc/resolv.conf: %m"); + + return 0; +} + +static int setup_boot_id(const char *dest) { + sd_id128_t rnd = SD_ID128_NULL; + const char *from, *to; + int r; + + /* Generate a new randomized boot ID, so that each boot-up of + * the container gets a new one */ + + from = prefix_roota(dest, "/run/proc-sys-kernel-random-boot-id"); + to = prefix_roota(dest, "/proc/sys/kernel/random/boot_id"); + + r = sd_id128_randomize(&rnd); + if (r < 0) + return log_error_errno(r, "Failed to generate random boot id: %m"); + + r = id128_write(from, ID128_UUID, rnd, false); + if (r < 0) + return log_error_errno(r, "Failed to write boot id: %m"); + + r = mount_verbose(LOG_ERR, from, to, NULL, MS_BIND, NULL); + if (r >= 0) + r = mount_verbose(LOG_ERR, NULL, to, NULL, + MS_BIND|MS_REMOUNT|MS_RDONLY|MS_NOSUID|MS_NODEV, NULL); + + (void) unlink(from); + return r; +} + +static int copy_devnodes(const char *dest) { + + static const char devnodes[] = + "null\0" + "zero\0" + "full\0" + "random\0" + "urandom\0" + "tty\0" + "net/tun\0"; + + const char *d; + int r = 0; + _cleanup_umask_ mode_t u; + + assert(dest); + + u = 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 = strappend("/dev/", d); + to = prefix_root(dest, from); + + 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)) { + + log_error("%s is not a char or block device, cannot copy.", from); + return -EIO; + + } else { + if (mknod(to, st.st_mode, st.st_rdev) < 0) { + /* + * This is some sort of protection too against + * recursive userns chown on shared /dev/ + */ + if (errno == EEXIST) + log_notice("%s/dev/ should be an empty directory", 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_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); + } + } + + return r; +} + +static int setup_pts(const char *dest) { + _cleanup_free_ char *options = NULL; + const char *p; + int r; + +#ifdef 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"); + if (mkdir(p, 0755) < 0) + return log_error_errno(errno, "Failed to create /dev/pts: %m"); + r = mount_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_dev_console(const char *dest, const char *console) { + _cleanup_umask_ mode_t u; + const char *to; + int r; + + assert(dest); + assert(console); + + u = umask(0000); + + r = chmod_and_chown(console, 0600, arg_uid_shift, arg_uid_shift); + if (r < 0) + return log_error_errno(r, "Failed to correct access mode for TTY: %m"); + + /* We need to bind mount the right tty to /dev/console since + * ptys can only exist on pts file systems. To have something + * to bind mount things on we create a empty regular file. */ + + to = prefix_roota(dest, "/dev/console"); + r = touch(to); + if (r < 0) + return log_error_errno(r, "touch() for /dev/console failed: %m"); + + return mount_verbose(LOG_ERR, console, to, NULL, MS_BIND, NULL); +} + +static int setup_kmsg(const char *dest, int kmsg_socket) { + const char *from, *to; + _cleanup_umask_ mode_t u; + int fd, r; + + assert(kmsg_socket >= 0); + + u = umask(0000); + + /* We create the kmsg FIFO as /run/kmsg, 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. */ + from = prefix_roota(dest, "/run/kmsg"); + to = prefix_roota(dest, "/proc/kmsg"); + + if (mkfifo(from, 0600) < 0) + return log_error_errno(errno, "mkfifo() for /run/kmsg failed: %m"); + r = mount_verbose(LOG_ERR, from, to, NULL, MS_BIND, NULL); + if (r < 0) + return r; + + fd = open(from, O_RDWR|O_NDELAY|O_CLOEXEC); + if (fd < 0) + return log_error_errno(errno, "Failed to open fifo: %m"); + + /* Store away the fd in the socket, so that it stays open as + * long as we run the child */ + r = send_one_fd(kmsg_socket, fd, 0); + safe_close(fd); + + if (r < 0) + return log_error_errno(r, "Failed to send FIFO fd: %m"); + + /* And now make the FIFO unavailable as /run/kmsg... */ + (void) unlink(from); + + return 0; +} + +static int on_address_change(sd_netlink *rtnl, sd_netlink_message *m, void *userdata) { + union in_addr_union *exposed = userdata; + + assert(rtnl); + assert(m); + assert(exposed); + + expose_port_execute(rtnl, arg_expose_ports, exposed); + return 0; +} + +static int setup_hostname(void) { + + if ((arg_clone_ns_flags & CLONE_NEWUTS) == 0) + return 0; + + if (sethostname_idempotent(arg_machine) < 0) + return -errno; + + return 0; +} + +static int setup_journal(const char *directory) { + sd_id128_t this_id; + _cleanup_free_ char *d = NULL; + const char *p, *q; + bool try; + char id[33]; + 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, id)); + if (try) + return 0; + return -EEXIST; + } + + r = userns_mkdir(directory, "/var", 0755, 0, 0); + if (r < 0) + return log_error_errno(r, "Failed to create /var: %m"); + + r = userns_mkdir(directory, "/var/log", 0755, 0, 0); + if (r < 0) + return log_error_errno(r, "Failed to create /var/log: %m"); + + r = userns_mkdir(directory, "/var/log/journal", 0755, 0, 0); + if (r < 0) + return log_error_errno(r, "Failed to create /var/log/journal: %m"); + + (void) sd_id128_to_string(arg_uuid, id); + + p = strjoina("/var/log/journal/", id); + q = prefix_roota(directory, p); + + if (path_is_mount_point(p, 0) > 0) { + if (try) + return 0; + + log_error("%s: already a mount point, refusing to use for journal", p); + return -EEXIST; + } + + if (path_is_mount_point(q, 0) > 0) { + if (try) + return 0; + + log_error("%s: already a mount point, refusing to use for journal", q); + return -EEXIST; + } + + r = readlink_and_make_absolute(p, &d); + if (r >= 0) { + if ((arg_link_journal == LINK_GUEST || + arg_link_journal == 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 */ + + if (mkdir(p, 0755) < 0 && errno != EEXIST) { + if (try) { + log_debug_errno(errno, "Failed to create %s, skipping journal setup: %m", p); + return 0; + } else + return log_error_errno(errno, "Failed to create %s: %m", p); + } + + } else if (access(p, F_OK) < 0) + return 0; + + if (dir_is_empty(q) == 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_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(void) { + return capability_bounding_set_drop(arg_caps_retain, false); +} + +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", 0); + if (r < 0) { + log_error_errno(r, + "Failed to reset audit login UID. This probably means that your kernel is too\n" + "old and you have audit enabled. Note that the auditing subsystem is known to\n" + "be incompatible with containers on old kernels. Please make sure to upgrade\n" + "your kernel or to off auditing with 'audit=0' on the kernel command line before\n" + "using systemd-nspawn. Sleeping for 5s... (%m)"); + + sleep(5); + } + + return 0; +} + + +static int setup_propagate(const char *root) { + const char *p, *q; + int r; + + (void) mkdir_p("/run/systemd/nspawn/", 0755); + (void) mkdir_p("/run/systemd/nspawn/propagate", 0600); + p = strjoina("/run/systemd/nspawn/propagate/", arg_machine); + (void) mkdir_p(p, 0600); + + r = userns_mkdir(root, "/run/systemd", 0755, 0, 0); + if (r < 0) + return log_error_errno(r, "Failed to create /run/systemd: %m"); + + r = userns_mkdir(root, "/run/systemd/nspawn", 0755, 0, 0); + if (r < 0) + return log_error_errno(r, "Failed to create /run/systemd/nspawn: %m"); + + r = userns_mkdir(root, "/run/systemd/nspawn/incoming", 0600, 0, 0); + if (r < 0) + return log_error_errno(r, "Failed to create /run/systemd/nspawn/incoming: %m"); + + q = prefix_roota(root, "/run/systemd/nspawn/incoming"); + r = mount_verbose(LOG_ERR, p, q, NULL, MS_BIND, NULL); + if (r < 0) + return r; + + r = mount_verbose(LOG_ERR, NULL, q, NULL, MS_BIND|MS_REMOUNT|MS_RDONLY, NULL); + if (r < 0) + return r; + + /* machined will MS_MOVE into that directory, and that's only + * supported for non-shared mounts. */ + return mount_verbose(LOG_ERR, NULL, q, NULL, MS_SLAVE, NULL); +} + +static int setup_image(char **device_path, int *loop_nr) { + struct loop_info64 info = { + .lo_flags = LO_FLAGS_AUTOCLEAR|LO_FLAGS_PARTSCAN + }; + _cleanup_close_ int fd = -1, control = -1, loop = -1; + _cleanup_free_ char* loopdev = NULL; + struct stat st; + int r, nr; + + assert(device_path); + assert(loop_nr); + assert(arg_image); + + fd = open(arg_image, O_CLOEXEC|(arg_read_only ? O_RDONLY : O_RDWR)|O_NONBLOCK|O_NOCTTY); + if (fd < 0) + return log_error_errno(errno, "Failed to open %s: %m", arg_image); + + if (fstat(fd, &st) < 0) + return log_error_errno(errno, "Failed to stat %s: %m", arg_image); + + if (S_ISBLK(st.st_mode)) { + char *p; + + p = strdup(arg_image); + if (!p) + return log_oom(); + + *device_path = p; + + *loop_nr = -1; + + r = fd; + fd = -1; + + return r; + } + + if (!S_ISREG(st.st_mode)) { + log_error("%s is not a regular file or block device.", arg_image); + return -EINVAL; + } + + control = open("/dev/loop-control", O_RDWR|O_CLOEXEC|O_NOCTTY|O_NONBLOCK); + if (control < 0) + return log_error_errno(errno, "Failed to open /dev/loop-control: %m"); + + nr = ioctl(control, LOOP_CTL_GET_FREE); + if (nr < 0) + return log_error_errno(errno, "Failed to allocate loop device: %m"); + + if (asprintf(&loopdev, "/dev/loop%i", nr) < 0) + return log_oom(); + + loop = open(loopdev, O_CLOEXEC|(arg_read_only ? O_RDONLY : O_RDWR)|O_NONBLOCK|O_NOCTTY); + if (loop < 0) + return log_error_errno(errno, "Failed to open loop device %s: %m", loopdev); + + if (ioctl(loop, LOOP_SET_FD, fd) < 0) + return log_error_errno(errno, "Failed to set loopback file descriptor on %s: %m", loopdev); + + if (arg_read_only) + info.lo_flags |= LO_FLAGS_READ_ONLY; + + if (ioctl(loop, LOOP_SET_STATUS64, &info) < 0) + return log_error_errno(errno, "Failed to set loopback settings on %s: %m", loopdev); + + *device_path = loopdev; + loopdev = NULL; + + *loop_nr = nr; + + r = loop; + loop = -1; + + return r; +} + +#define PARTITION_TABLE_BLURB \ + "Note that the disk image needs to either contain only a single MBR partition of\n" \ + "type 0x83 that is marked bootable, or a single GPT partition of type " \ + "0FC63DAF-8483-4772-8E79-3D69D8477DE4 or follow\n" \ + " http://www.freedesktop.org/wiki/Specifications/DiscoverablePartitionsSpec/\n" \ + "to be bootable with systemd-nspawn." + +static int dissect_image( + int fd, + char **root_device, bool *root_device_rw, + char **home_device, bool *home_device_rw, + char **srv_device, bool *srv_device_rw, + char **esp_device, + bool *secondary) { + +#ifdef HAVE_BLKID + int home_nr = -1, srv_nr = -1, esp_nr = -1; +#ifdef GPT_ROOT_NATIVE + int root_nr = -1; +#endif +#ifdef GPT_ROOT_SECONDARY + int secondary_root_nr = -1; +#endif + _cleanup_free_ char *home = NULL, *root = NULL, *secondary_root = NULL, *srv = NULL, *esp = NULL, *generic = NULL; + _cleanup_udev_enumerate_unref_ struct udev_enumerate *e = NULL; + _cleanup_udev_device_unref_ struct udev_device *d = NULL; + _cleanup_blkid_free_probe_ blkid_probe b = NULL; + _cleanup_udev_unref_ struct udev *udev = NULL; + struct udev_list_entry *first, *item; + bool home_rw = true, root_rw = true, secondary_root_rw = true, srv_rw = true, generic_rw = true; + bool is_gpt, is_mbr, multiple_generic = false; + const char *pttype = NULL; + blkid_partlist pl; + struct stat st; + unsigned i; + int r; + + assert(fd >= 0); + assert(root_device); + assert(home_device); + assert(srv_device); + assert(esp_device); + assert(secondary); + assert(arg_image); + + b = blkid_new_probe(); + if (!b) + return log_oom(); + + errno = 0; + r = blkid_probe_set_device(b, fd, 0, 0); + if (r != 0) { + if (errno == 0) + return log_oom(); + + return log_error_errno(errno, "Failed to set device on blkid probe: %m"); + } + + blkid_probe_enable_partitions(b, 1); + blkid_probe_set_partitions_flags(b, BLKID_PARTS_ENTRY_DETAILS); + + errno = 0; + r = blkid_do_safeprobe(b); + if (r == -2 || r == 1) { + log_error("Failed to identify any partition table on\n" + " %s\n" + PARTITION_TABLE_BLURB, arg_image); + return -EINVAL; + } else if (r != 0) { + if (errno == 0) + errno = EIO; + return log_error_errno(errno, "Failed to probe: %m"); + } + + (void) blkid_probe_lookup_value(b, "PTTYPE", &pttype, NULL); + + is_gpt = streq_ptr(pttype, "gpt"); + is_mbr = streq_ptr(pttype, "dos"); + + if (!is_gpt && !is_mbr) { + log_error("No GPT or MBR partition table discovered on\n" + " %s\n" + PARTITION_TABLE_BLURB, arg_image); + return -EINVAL; + } + + errno = 0; + pl = blkid_probe_get_partitions(b); + if (!pl) { + if (errno == 0) + return log_oom(); + + log_error("Failed to list partitions of %s", arg_image); + return -errno; + } + + udev = udev_new(); + if (!udev) + return log_oom(); + + if (fstat(fd, &st) < 0) + return log_error_errno(errno, "Failed to stat block device: %m"); + + d = udev_device_new_from_devnum(udev, 'b', st.st_rdev); + if (!d) + return log_oom(); + + for (i = 0;; i++) { + int n, m; + + if (i >= 10) { + log_error("Kernel partitions never appeared."); + return -ENXIO; + } + + e = udev_enumerate_new(udev); + if (!e) + return log_oom(); + + r = udev_enumerate_add_match_parent(e, d); + if (r < 0) + return log_oom(); + + r = udev_enumerate_scan_devices(e); + if (r < 0) + return log_error_errno(r, "Failed to scan for partition devices of %s: %m", arg_image); + + /* Count the partitions enumerated by the kernel */ + n = 0; + first = udev_enumerate_get_list_entry(e); + udev_list_entry_foreach(item, first) + n++; + + /* Count the partitions enumerated by blkid */ + m = blkid_partlist_numof_partitions(pl); + if (n == m + 1) + break; + if (n > m + 1) { + log_error("blkid and kernel partition list do not match."); + return -EIO; + } + if (n < m + 1) { + unsigned j; + + /* The kernel has probed fewer partitions than + * blkid? Maybe the kernel prober is still + * running or it got EBUSY because udev + * already opened the device. Let's reprobe + * the device, which is a synchronous call + * that waits until probing is complete. */ + + for (j = 0; j < 20; j++) { + + r = ioctl(fd, BLKRRPART, 0); + if (r < 0) + r = -errno; + if (r >= 0 || r != -EBUSY) + break; + + /* If something else has the device + * open, such as an udev rule, the + * ioctl will return EBUSY. Since + * there's no way to wait until it + * isn't busy anymore, let's just wait + * a bit, and try again. + * + * This is really something they + * should fix in the kernel! */ + + usleep(50 * USEC_PER_MSEC); + } + + if (r < 0) + return log_error_errno(r, "Failed to reread partition table: %m"); + } + + e = udev_enumerate_unref(e); + } + + first = udev_enumerate_get_list_entry(e); + udev_list_entry_foreach(item, first) { + _cleanup_udev_device_unref_ struct udev_device *q; + const char *node; + unsigned long long flags; + blkid_partition pp; + dev_t qn; + int nr; + + errno = 0; + q = udev_device_new_from_syspath(udev, udev_list_entry_get_name(item)); + if (!q) { + if (!errno) + errno = ENOMEM; + + return log_error_errno(errno, "Failed to get partition device of %s: %m", arg_image); + } + + qn = udev_device_get_devnum(q); + if (major(qn) == 0) + continue; + + if (st.st_rdev == qn) + continue; + + node = udev_device_get_devnode(q); + if (!node) + continue; + + pp = blkid_partlist_devno_to_partition(pl, qn); + if (!pp) + continue; + + flags = blkid_partition_get_flags(pp); + + nr = blkid_partition_get_partno(pp); + if (nr < 0) + continue; + + if (is_gpt) { + sd_id128_t type_id; + const char *stype; + + if (flags & GPT_FLAG_NO_AUTO) + continue; + + stype = blkid_partition_get_type_string(pp); + if (!stype) + continue; + + if (sd_id128_from_string(stype, &type_id) < 0) + continue; + + if (sd_id128_equal(type_id, GPT_HOME)) { + + if (home && nr >= home_nr) + continue; + + home_nr = nr; + home_rw = !(flags & GPT_FLAG_READ_ONLY); + + r = free_and_strdup(&home, node); + if (r < 0) + return log_oom(); + + } else if (sd_id128_equal(type_id, GPT_SRV)) { + + if (srv && nr >= srv_nr) + continue; + + srv_nr = nr; + srv_rw = !(flags & GPT_FLAG_READ_ONLY); + + r = free_and_strdup(&srv, node); + if (r < 0) + return log_oom(); + } else if (sd_id128_equal(type_id, GPT_ESP)) { + + if (esp && nr >= esp_nr) + continue; + + esp_nr = nr; + + r = free_and_strdup(&esp, node); + if (r < 0) + return log_oom(); + } +#ifdef GPT_ROOT_NATIVE + else if (sd_id128_equal(type_id, GPT_ROOT_NATIVE)) { + + if (root && nr >= root_nr) + continue; + + root_nr = nr; + root_rw = !(flags & GPT_FLAG_READ_ONLY); + + r = free_and_strdup(&root, node); + if (r < 0) + return log_oom(); + } +#endif +#ifdef GPT_ROOT_SECONDARY + else if (sd_id128_equal(type_id, GPT_ROOT_SECONDARY)) { + + if (secondary_root && nr >= secondary_root_nr) + continue; + + secondary_root_nr = nr; + secondary_root_rw = !(flags & GPT_FLAG_READ_ONLY); + + r = free_and_strdup(&secondary_root, node); + if (r < 0) + return log_oom(); + } +#endif + else if (sd_id128_equal(type_id, GPT_LINUX_GENERIC)) { + + if (generic) + multiple_generic = true; + else { + generic_rw = !(flags & GPT_FLAG_READ_ONLY); + + r = free_and_strdup(&generic, node); + if (r < 0) + return log_oom(); + } + } + + } else if (is_mbr) { + int type; + + if (flags != 0x80) /* Bootable flag */ + continue; + + type = blkid_partition_get_type(pp); + if (type != 0x83) /* Linux partition */ + continue; + + if (generic) + multiple_generic = true; + else { + generic_rw = true; + + r = free_and_strdup(&root, node); + if (r < 0) + return log_oom(); + } + } + } + + if (root) { + *root_device = root; + root = NULL; + + *root_device_rw = root_rw; + *secondary = false; + } else if (secondary_root) { + *root_device = secondary_root; + secondary_root = NULL; + + *root_device_rw = secondary_root_rw; + *secondary = true; + } else if (generic) { + + /* There were no partitions with precise meanings + * around, but we found generic partitions. In this + * case, if there's only one, we can go ahead and boot + * it, otherwise we bail out, because we really cannot + * make any sense of it. */ + + if (multiple_generic) { + log_error("Identified multiple bootable Linux partitions on\n" + " %s\n" + PARTITION_TABLE_BLURB, arg_image); + return -EINVAL; + } + + *root_device = generic; + generic = NULL; + + *root_device_rw = generic_rw; + *secondary = false; + } else { + log_error("Failed to identify root partition in disk image\n" + " %s\n" + PARTITION_TABLE_BLURB, arg_image); + return -EINVAL; + } + + if (home) { + *home_device = home; + home = NULL; + + *home_device_rw = home_rw; + } + + if (srv) { + *srv_device = srv; + srv = NULL; + + *srv_device_rw = srv_rw; + } + + if (esp) { + *esp_device = esp; + esp = NULL; + } + + return 0; +#else + log_error("--image= is not supported, compiled without blkid support."); + return -EOPNOTSUPP; +#endif +} + +static int mount_device(const char *what, const char *where, const char *directory, bool rw) { +#ifdef HAVE_BLKID + _cleanup_blkid_free_probe_ blkid_probe b = NULL; + const char *fstype, *p, *options; + int r; + + assert(what); + assert(where); + + if (arg_read_only) + rw = false; + + if (directory) + p = strjoina(where, directory); + else + p = where; + + errno = 0; + b = blkid_new_probe_from_filename(what); + if (!b) { + if (errno == 0) + return log_oom(); + return log_error_errno(errno, "Failed to allocate prober for %s: %m", what); + } + + blkid_probe_enable_superblocks(b, 1); + blkid_probe_set_superblocks_flags(b, BLKID_SUBLKS_TYPE); + + errno = 0; + r = blkid_do_safeprobe(b); + if (r == -1 || r == 1) { + log_error("Cannot determine file system type of %s", what); + return -EINVAL; + } else if (r != 0) { + if (errno == 0) + errno = EIO; + return log_error_errno(errno, "Failed to probe %s: %m", what); + } + + errno = 0; + if (blkid_probe_lookup_value(b, "TYPE", &fstype, NULL) < 0) { + if (errno == 0) + errno = EINVAL; + log_error("Failed to determine file system type of %s", what); + return -errno; + } + + if (streq(fstype, "crypto_LUKS")) { + log_error("nspawn currently does not support LUKS disk images."); + return -EOPNOTSUPP; + } + + /* If this is a loopback device then let's mount the image with discard, so that the underlying file remains + * sparse when possible. */ + if (STR_IN_SET(fstype, "btrfs", "ext4", "vfat", "xfs")) { + const char *l; + + l = path_startswith(what, "/dev"); + if (l && startswith(l, "loop")) + options = "discard"; + } + + return mount_verbose(LOG_ERR, what, p, fstype, MS_NODEV|(rw ? 0 : MS_RDONLY), options); +#else + log_error("--image= is not supported, compiled without blkid support."); + return -EOPNOTSUPP; +#endif +} + +static int setup_machine_id(const char *directory) { + const char *etc_machine_id; + sd_id128_t id; + int r; + + /* If the UUID in the container is already set, then that's what counts, and we use. If it isn't set, and the + * caller passed --uuid=, then we'll pass it in the $container_uuid env var to PID 1 of the container. The + * assumption is that PID 1 will then write it to /etc/machine-id to make it persistent. If --uuid= is not + * passed we generate a random UUID, and pass it via $container_uuid. In effect this means that /etc/machine-id + * in the container and our idea of the container UUID will always be in sync (at least if PID 1 in the + * container behaves nicely). */ + + etc_machine_id = prefix_roota(directory, "/etc/machine-id"); + + r = id128_read(etc_machine_id, ID128_PLAIN, &id); + if (r < 0) { + if (!IN_SET(r, -ENOENT, -ENOMEDIUM)) /* If the file is missing or empty, we don't mind */ + return log_error_errno(r, "Failed to read machine ID from container image: %m"); + + if (sd_id128_is_null(arg_uuid)) { + r = sd_id128_randomize(&arg_uuid); + if (r < 0) + return log_error_errno(r, "Failed to acquire randomized machine UUID: %m"); + } + } else { + if (sd_id128_is_null(id)) { + log_error("Machine ID in container image is zero, refusing."); + return -EINVAL; + } + + arg_uuid = id; + } + + return 0; +} + +static int recursive_chown(const char *directory, uid_t shift, uid_t range) { + int r; + + assert(directory); + + if (arg_userns_mode == USER_NAMESPACE_NO || !arg_userns_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; +} + +static int mount_devices( + const char *where, + const char *root_device, bool root_device_rw, + const char *home_device, bool home_device_rw, + const char *srv_device, bool srv_device_rw, + const char *esp_device) { + int r; + + assert(where); + + if (root_device) { + r = mount_device(root_device, arg_directory, NULL, root_device_rw); + if (r < 0) + return log_error_errno(r, "Failed to mount root directory: %m"); + } + + if (home_device) { + r = mount_device(home_device, arg_directory, "/home", home_device_rw); + if (r < 0) + return log_error_errno(r, "Failed to mount home directory: %m"); + } + + if (srv_device) { + r = mount_device(srv_device, arg_directory, "/srv", srv_device_rw); + if (r < 0) + return log_error_errno(r, "Failed to mount server data directory: %m"); + } + + if (esp_device) { + const char *mp, *x; + + /* Mount the ESP to /efi if it exists and is empty. If it doesn't exist, use /boot instead. */ + + mp = "/efi"; + x = strjoina(arg_directory, mp); + r = dir_is_empty(x); + if (r == -ENOENT) { + mp = "/boot"; + x = strjoina(arg_directory, mp); + r = dir_is_empty(x); + } + + if (r > 0) { + r = mount_device(esp_device, arg_directory, mp, true); + if (r < 0) + return log_error_errno(r, "Failed to mount ESP: %m"); + } + } + + return 0; +} + +static void loop_remove(int nr, int *image_fd) { + _cleanup_close_ int control = -1; + int r; + + if (nr < 0) + return; + + if (image_fd && *image_fd >= 0) { + r = ioctl(*image_fd, LOOP_CLR_FD); + if (r < 0) + log_debug_errno(errno, "Failed to close loop image: %m"); + *image_fd = safe_close(*image_fd); + } + + control = open("/dev/loop-control", O_RDWR|O_CLOEXEC|O_NOCTTY|O_NONBLOCK); + if (control < 0) { + log_warning_errno(errno, "Failed to open /dev/loop-control: %m"); + return; + } + + r = ioctl(control, LOOP_CTL_REMOVE, nr); + if (r < 0) + log_debug_errno(errno, "Failed to remove loop %d: %m", nr); +} + +/* + * 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; + } + + /* CLD_KILLED fallthrough */ + + case CLD_DUMPED: + log_error("Container %s terminated by signal %s.", arg_machine, signal_to_string(status.si_status)); + return -EIO; + + default: + log_error("Container %s failed due to unknown reason.", arg_machine); + return -EIO; + } +} + +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 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 = strjoin("/var/lib/machines/", arg_machine, NULL); + if (!arg_directory) + return log_oom(); + } + + if (!arg_image && !arg_directory) { + if (arg_machine) { + _cleanup_(image_unrefp) Image *i = NULL; + + r = image_find(arg_machine, &i); + if (r < 0) + return log_error_errno(r, "Failed to find image for machine '%s': %m", arg_machine); + else if (r == 0) { + log_error("No image for machine '%s': %m", arg_machine); + return -ENOENT; + } + + if (i->type == IMAGE_RAW) + r = free_and_strdup(&arg_image, i->path); + else + r = free_and_strdup(&arg_directory, i->path); + if (r < 0) + return log_error_errno(r, "Invalid image directory: %m"); + + if (!arg_ephemeral) + arg_read_only = arg_read_only || i->read_only; + } else + arg_directory = get_current_dir_name(); + + if (!arg_directory && !arg_machine) { + log_error("Failed to determine path, please use -D or -i."); + return -EINVAL; + } + } + + if (!arg_machine) { + if (arg_directory && path_equal(arg_directory, "/")) + arg_machine = gethostname_malloc(); + else + arg_machine = strdup(basename(arg_image ?: arg_directory)); + + if (!arg_machine) + return log_oom(); + + hostname_cleanup(arg_machine); + if (!machine_name_is_valid(arg_machine)) { + log_error("Failed to determine machine name automatically, please use -M."); + return -EINVAL; + } + + if (arg_ephemeral) { + char *b; + + /* 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 (asprintf(&b, "%s-%016" PRIx64, arg_machine, random_u64()) < 0) + return log_oom(); + + free(arg_machine); + arg_machine = b; + } + } + + return 0; +} + +static int determine_uid_shift(const char *directory) { + int r; + + if (arg_userns_mode == USER_NAMESPACE_NO) { + arg_uid_shift = 0; + return 0; + } + + if (arg_uid_shift == UID_INVALID) { + struct stat st; + + r = stat(directory, &st); + if (r < 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))) { + log_error("UID and GID base of %s don't match.", directory); + return -EINVAL; + } + + arg_uid_range = UINT32_C(0x10000); + } + + if (arg_uid_shift > (uid_t) -1 - arg_uid_range) { + log_error("UID base too high for UID range."); + return -EINVAL; + } + + return 0; +} + +static int inner_child( + Barrier *barrier, + const char *directory, + bool secondary, + int kmsg_socket, + int rtnl_socket, + FDSet *fds) { + + _cleanup_free_ char *home = NULL; + char as_uuid[37]; + unsigned n_env = 1; + const char *envp[] = { + "PATH=" DEFAULT_PATH_SPLIT_USR, + NULL, /* container */ + NULL, /* TERM */ + NULL, /* HOME */ + NULL, /* USER */ + NULL, /* LOGNAME */ + NULL, /* container_uuid */ + NULL, /* LISTEN_FDS */ + NULL, /* LISTEN_PID */ + NULL, /* NOTIFY_SOCKET */ + NULL + }; + + _cleanup_strv_free_ char **env_use = NULL; + int r; + + assert(barrier); + assert(directory); + assert(kmsg_socket >= 0); + + cg_unified_flush(); + + 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 */ + log_error("Parent died too early"); + return -ESRCH; + } + } + + r = reset_uid_gid(); + if (r < 0) + return log_error_errno(r, "Couldn't become new root: %m"); + + r = mount_all(NULL, + arg_userns_mode != USER_NAMESPACE_NO, + true, + arg_private_network, + arg_uid_shift, + arg_uid_range, + arg_selinux_apifs_context); + + if (r < 0) + return r; + + r = mount_sysfs(NULL); + 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)) { /* #3 */ + log_error("Parent died too early"); + return -ESRCH; + } + + if (arg_use_cgns && cg_ns_supported()) { + r = unshare(CLONE_NEWCGROUP); + if (r < 0) + return log_error_errno(errno, "Failed to unshare cgroup namespace"); + r = mount_cgroups( + "", + arg_unified_cgroup_hierarchy, + arg_userns_mode != USER_NAMESPACE_NO, + arg_uid_shift, + arg_uid_range, + arg_selinux_apifs_context, + true); + if (r < 0) + return r; + } else { + r = mount_systemd_cgroup_writable("", arg_unified_cgroup_hierarchy); + if (r < 0) + return r; + } + + r = setup_boot_id(NULL); + if (r < 0) + return r; + + r = setup_kmsg(NULL, kmsg_socket); + if (r < 0) + return r; + kmsg_socket = safe_close(kmsg_socket); + + umask(0022); + + if (setsid() < 0) + return log_error_errno(errno, "setsid() failed: %m"); + + if (arg_private_network) + loopback_setup(); + + if (arg_expose_ports) { + r = expose_port_send_rtnl(rtnl_socket); + if (r < 0) + return r; + rtnl_socket = safe_close(rtnl_socket); + } + + r = drop_capabilities(); + if (r < 0) + return log_error_errno(r, "drop_capabilities() failed: %m"); + + setup_hostname(); + + if (arg_personality != PERSONALITY_INVALID) { + if (personality(arg_personality) < 0) + return log_error_errno(errno, "personality() failed: %m"); + } else if (secondary) { + if (personality(PER_LINUX32) < 0) + return log_error_errno(errno, "personality() failed: %m"); + } + +#ifdef 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 + + r = change_uid_gid(arg_user, &home); + if (r < 0) + return r; + + /* 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 ((asprintf((char**)(envp + n_env++), "HOME=%s", home ? home: "/root") < 0) || + (asprintf((char**)(envp + n_env++), "USER=%s", arg_user ? arg_user : "root") < 0) || + (asprintf((char**)(envp + n_env++), "LOGNAME=%s", arg_user ? arg_user : "root") < 0)) + return log_oom(); + + assert(!sd_id128_is_null(arg_uuid)); + + if (asprintf((char**)(envp + n_env++), "container_uuid=%s", id128_to_uuid_string(arg_uuid, as_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((char **)(envp + n_env++), "LISTEN_FDS=%u", fdset_size(fds)) < 0) || + (asprintf((char **)(envp + n_env++), "LISTEN_PID=1") < 0)) + return log_oom(); + } + if (asprintf((char **)(envp + n_env++), "NOTIFY_SOCKET=%s", NSPAWN_NOTIFY_SOCKET_PATH) < 0) + return log_oom(); + + env_use = strv_env_merge(2, envp, 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)) { /* #4 */ + log_error("Parent died too early"); + return -ESRCH; + } + + 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(); + if (r < 0) + return r; + } + + /* 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(); + (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; + + a[0] = (char*) "/usr/lib/systemd/systemd"; + execve(a[0], a, env_use); + + a[0] = (char*) "/lib/systemd/systemd"; + execve(a[0], a, env_use); + + a[0] = (char*) "/sbin/init"; + execve(a[0], a, env_use); + } else if (!strv_isempty(arg_parameters)) + 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("/bin/bash", "-bash", NULL, env_use); + execle("/bin/sh", "-sh", NULL, env_use); + } + + r = -errno; + (void) log_open(); + return log_error_errno(r, "execv() failed: %m"); +} + +static int setup_sd_notify_child(void) { + static const int one = 1; + int fd = -1; + union sockaddr_union sa = { + .sa.sa_family = AF_UNIX, + }; + 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) unlink(NSPAWN_NOTIFY_SOCKET_PATH); + + strncpy(sa.un.sun_path, NSPAWN_NOTIFY_SOCKET_PATH, sizeof(sa.un.sun_path)-1); + r = bind(fd, &sa.sa, SOCKADDR_UN_LEN(sa.un)); + if (r < 0) { + safe_close(fd); + return log_error_errno(errno, "bind(%s) failed: %m", sa.un.sun_path); + } + + r = setsockopt(fd, SOL_SOCKET, SO_PASSCRED, &one, sizeof(one)); + if (r < 0) { + safe_close(fd); + return log_error_errno(errno, "SO_PASSCRED failed: %m"); + } + + return fd; +} + +static int outer_child( + Barrier *barrier, + const char *directory, + const char *console, + const char *root_device, bool root_device_rw, + const char *home_device, bool home_device_rw, + const char *srv_device, bool srv_device_rw, + const char *esp_device, + bool interactive, + bool secondary, + int pid_socket, + int uuid_socket, + int notify_socket, + int kmsg_socket, + int rtnl_socket, + int uid_shift_socket, + FDSet *fds) { + + pid_t pid; + ssize_t l; + int r; + _cleanup_close_ int fd = -1; + + assert(barrier); + assert(directory); + assert(console); + assert(pid_socket >= 0); + assert(uuid_socket >= 0); + assert(notify_socket >= 0); + assert(kmsg_socket >= 0); + + cg_unified_flush(); + + if (prctl(PR_SET_PDEATHSIG, SIGKILL) < 0) + return log_error_errno(errno, "PR_SET_PDEATHSIG failed: %m"); + + if (interactive) { + close_nointr(STDIN_FILENO); + close_nointr(STDOUT_FILENO); + close_nointr(STDERR_FILENO); + + r = open_terminal(console, O_RDWR); + if (r != STDIN_FILENO) { + if (r >= 0) { + safe_close(r); + r = -EINVAL; + } + + return log_error_errno(r, "Failed to open console: %m"); + } + + if (dup2(STDIN_FILENO, STDOUT_FILENO) != STDOUT_FILENO || + dup2(STDIN_FILENO, STDERR_FILENO) != STDERR_FILENO) + return log_error_errno(errno, "Failed to duplicate console: %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_verbose(LOG_ERR, NULL, "/", NULL, MS_SLAVE|MS_REC, NULL); + if (r < 0) + return r; + + r = mount_devices(directory, + root_device, root_device_rw, + home_device, home_device_rw, + srv_device, srv_device_rw, + esp_device); + if (r < 0) + return r; + + r = determine_uid_shift(directory); + if (r < 0) + return r; + + r = detect_unified_cgroup_hierarchy(directory); + if (r < 0) + return r; + + if (arg_userns_mode != USER_NAMESPACE_NO) { + /* Let the parent know which UID shift we read from the image */ + l = send(uid_shift_socket, &arg_uid_shift, sizeof(arg_uid_shift), MSG_NOSIGNAL); + if (l < 0) + return log_error_errno(errno, "Failed to send UID shift: %m"); + if (l != sizeof(arg_uid_shift)) { + log_error("Short write while sending UID shift."); + return -EIO; + } + + if (arg_userns_mode == USER_NAMESPACE_PICK) { + /* When we are supposed to pick the UID shift, the parent will check now whether the UID shift + * we just read from the image is available. If yes, it will send the UID shift back to us, if + * not it will pick a different one, and send it back to us. */ + + l = recv(uid_shift_socket, &arg_uid_shift, sizeof(arg_uid_shift), 0); + if (l < 0) + return log_error_errno(errno, "Failed to recv UID shift: %m"); + if (l != sizeof(arg_uid_shift)) { + log_error("Short read while receiving UID shift."); + return -EIO; + } + } + + log_info("Selected user namespace base " UID_FMT " and range " UID_FMT ".", arg_uid_shift, arg_uid_range); + } + + /* Turn directory into bind mount */ + r = mount_verbose(LOG_ERR, directory, directory, NULL, MS_BIND|MS_REC, NULL); + 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 containter 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.*/ + r = mount_verbose(LOG_ERR, NULL, directory, NULL, MS_SHARED|MS_REC, NULL); + if (r < 0) + return r; + + r = recursive_chown(directory, arg_uid_shift, arg_uid_range); + if (r < 0) + return r; + + r = setup_volatile( + directory, + arg_volatile_mode, + arg_userns_mode != USER_NAMESPACE_NO, + arg_uid_shift, + arg_uid_range, + arg_selinux_context); + if (r < 0) + return r; + + r = setup_volatile_state( + directory, + arg_volatile_mode, + arg_userns_mode != USER_NAMESPACE_NO, + arg_uid_shift, + arg_uid_range, + arg_selinux_context); + 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) { + r = bind_remount_recursive(directory, true, NULL); + if (r < 0) + return log_error_errno(r, "Failed to make tree read-only: %m"); + } + + r = mount_all(directory, + arg_userns_mode != USER_NAMESPACE_NO, + false, + arg_private_network, + arg_uid_shift, + arg_uid_range, + arg_selinux_apifs_context); + if (r < 0) + return r; + + r = copy_devnodes(directory); + if (r < 0) + return r; + + dev_setup(directory, arg_uid_shift, arg_uid_shift); + + r = setup_pts(directory); + if (r < 0) + return r; + + r = setup_propagate(directory); + if (r < 0) + return r; + + r = setup_dev_console(directory, console); + if (r < 0) + return r; + + r = setup_seccomp(arg_caps_retain); + 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; + + r = mount_custom( + directory, + arg_custom_mounts, + arg_n_custom_mounts, + arg_userns_mode != USER_NAMESPACE_NO, + arg_uid_shift, + arg_uid_range, + arg_selinux_apifs_context); + if (r < 0) + return r; + + if (!arg_use_cgns || !cg_ns_supported()) { + r = mount_cgroups( + directory, + arg_unified_cgroup_hierarchy, + arg_userns_mode != USER_NAMESPACE_NO, + arg_uid_shift, + arg_uid_range, + arg_selinux_apifs_context, + false); + if (r < 0) + return r; + } + + r = mount_move_root(directory); + if (r < 0) + return log_error_errno(r, "Failed to move root directory: %m"); + + fd = setup_sd_notify_child(); + if (fd < 0) + return fd; + + pid = raw_clone(SIGCHLD|CLONE_NEWNS| + arg_clone_ns_flags | + (arg_private_network ? CLONE_NEWNET : 0) | + (arg_userns_mode != USER_NAMESPACE_NO ? CLONE_NEWUSER : 0)); + if (pid < 0) + return log_error_errno(errno, "Failed to fork inner child: %m"); + if (pid == 0) { + pid_socket = safe_close(pid_socket); + uuid_socket = safe_close(uuid_socket); + notify_socket = safe_close(notify_socket); + uid_shift_socket = safe_close(uid_shift_socket); + + /* The inner child has all namespaces that are + * requested, so that we all are owned by the user if + * user namespaces are turned on. */ + + r = inner_child(barrier, directory, secondary, kmsg_socket, rtnl_socket, fds); + if (r < 0) + _exit(EXIT_FAILURE); + + _exit(EXIT_SUCCESS); + } + + l = send(pid_socket, &pid, sizeof(pid), MSG_NOSIGNAL); + if (l < 0) + return log_error_errno(errno, "Failed to send PID: %m"); + if (l != sizeof(pid)) { + log_error("Short write while sending PID."); + return -EIO; + } + + l = send(uuid_socket, &arg_uuid, sizeof(arg_uuid), MSG_NOSIGNAL); + if (l < 0) + return log_error_errno(errno, "Failed to send machine ID: %m"); + if (l != sizeof(arg_uuid)) { + log_error("Short write while sending machine ID."); + return -EIO; + } + + l = send_one_fd(notify_socket, fd, 0); + if (l < 0) + return log_error_errno(errno, "Failed to send notify fd: %m"); + + pid_socket = safe_close(pid_socket); + uuid_socket = safe_close(uuid_socket); + notify_socket = safe_close(notify_socket); + kmsg_socket = safe_close(kmsg_socket); + rtnl_socket = safe_close(rtnl_socket); + + return 0; +} + +static int uid_shift_pick(uid_t *shift, LockFile *ret_lock_file) { + 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 < UID_SHIFT_PICK_MIN || candidate > UID_SHIFT_PICK_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: + random_bytes(&candidate, sizeof(candidate)); + candidate = (candidate % (UID_SHIFT_PICK_MAX - UID_SHIFT_PICK_MIN)) + UID_SHIFT_PICK_MIN; + candidate &= (uid_t) UINT32_C(0xFFFF0000); + } +} + +static int setup_uid_map(pid_t pid) { + char uid_map[strlen("/proc//uid_map") + DECIMAL_STR_MAX(uid_t) + 1], line[DECIMAL_STR_MAX(uid_t)*3+3+1]; + int r; + + assert(pid > 1); + + xsprintf(uid_map, "/proc/" PID_FMT "/uid_map", pid); + xsprintf(line, UID_FMT " " UID_FMT " " UID_FMT "\n", 0, arg_uid_shift, arg_uid_range); + r = write_string_file(uid_map, line, 0); + if (r < 0) + return log_error_errno(r, "Failed to write UID map: %m"); + + /* We always assign the same UID and GID ranges */ + xsprintf(uid_map, "/proc/" PID_FMT "/gid_map", pid); + r = write_string_file(uid_map, line, 0); + 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, + }; + union { + struct cmsghdr cmsghdr; + uint8_t buf[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 cmsghdr *cmsg; + struct ucred *ucred = NULL; + ssize_t n; + pid_t inner_child_pid; + _cleanup_strv_free_ char **tags = NULL; + + 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(fd, &msghdr, MSG_DONTWAIT|MSG_CMSG_CLOEXEC); + if (n < 0) { + if (errno == EAGAIN || errno == EINTR) + return 0; + + return log_warning_errno(errno, "Couldn't read notification socket: %m"); + } + cmsg_close_all(&msghdr); + + CMSG_FOREACH(cmsg, &msghdr) { + if (cmsg->cmsg_level == SOL_SOCKET && + cmsg->cmsg_type == SCM_CREDENTIALS && + cmsg->cmsg_len == CMSG_LEN(sizeof(struct ucred))) { + + ucred = (struct ucred*) CMSG_DATA(cmsg); + } + } + + if (!ucred || ucred->pid != inner_child_pid) { + log_warning("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_find(tags, "READY=1")) + sd_notifyf(false, "READY=1\n"); + + p = strv_find_startswith(tags, "STATUS="); + if (p) + sd_notifyf(false, "STATUS=Container running: %s", p); + + return 0; +} + +static int setup_sd_notify_parent(sd_event *event, int fd, pid_t *inner_child_pid) { + int r; + sd_event_source *notify_event_source; + + r = sd_event_add_io(event, ¬ify_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 load_settings(void) { + _cleanup_(settings_freep) Settings *settings = NULL; + _cleanup_fclose_ FILE *f = NULL; + _cleanup_free_ char *p = NULL; + const char *fn, *i; + int r; + + /* If all settings are masked, there's no point in looking for + * the settings file */ + if ((arg_settings_mask & _SETTINGS_MASK_ALL) == _SETTINGS_MASK_ALL) + return 0; + + fn = strjoina(arg_machine, ".nspawn"); + + /* 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 = strjoin(i, "/", fn, NULL); + if (!j) + return log_oom(); + + f = fopen(j, "re"); + if (f) { + p = j; + j = NULL; + + /* By default, we trust configuration from /etc and /run */ + if (arg_settings_trusted < 0) + arg_settings_trusted = true; + + break; + } + + if (errno != ENOENT) + return log_error_errno(errno, "Failed to open %s: %m", j); + } + + if (!f) { + /* After that, let's look for a file next to the + * actual image we shall boot. */ + + if (arg_image) { + p = file_in_same_dir(arg_image, fn); + if (!p) + return log_oom(); + } else if (arg_directory) { + p = file_in_same_dir(arg_directory, fn); + if (!p) + return log_oom(); + } + + if (p) { + f = fopen(p, "re"); + if (!f && errno != ENOENT) + return log_error_errno(errno, "Failed to open %s: %m", p); + + /* By default, we do not trust configuration from /var/lib/machines */ + if (arg_settings_trusted < 0) + arg_settings_trusted = false; + } + } + + if (!f) + return 0; + + log_debug("Settings are trusted: %s", yes_no(arg_settings_trusted)); + + r = settings_load(f, p, &settings); + if (r < 0) + return r; + + /* Copy over bits from the settings, unless they have been + * explicitly masked by command line switches. */ + + if ((arg_settings_mask & SETTING_START_MODE) == 0 && + settings->start_mode >= 0) { + arg_start_mode = settings->start_mode; + + strv_free(arg_parameters); + arg_parameters = settings->parameters; + settings->parameters = NULL; + } + + if ((arg_settings_mask & SETTING_WORKING_DIRECTORY) == 0 && + settings->working_directory) { + free(arg_chdir); + arg_chdir = settings->working_directory; + settings->working_directory = NULL; + } + + if ((arg_settings_mask & SETTING_ENVIRONMENT) == 0 && + settings->environment) { + strv_free(arg_setenv); + arg_setenv = settings->environment; + settings->environment = NULL; + } + + if ((arg_settings_mask & SETTING_USER) == 0 && + settings->user) { + free(arg_user); + arg_user = settings->user; + settings->user = NULL; + } + + if ((arg_settings_mask & SETTING_CAPABILITY) == 0) { + uint64_t plus; + + plus = settings->capability; + if (settings_private_network(settings)) + plus |= (1ULL << CAP_NET_ADMIN); + + if (!arg_settings_trusted && plus != 0) { + if (settings->capability != 0) + log_warning("Ignoring Capability= setting, file %s is not trusted.", p); + } else + arg_caps_retain |= plus; + + arg_caps_retain &= ~settings->drop_capability; + } + + 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.", p); + 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.", p); + else { + custom_mount_free_all(arg_custom_mounts, arg_n_custom_mounts); + arg_custom_mounts = settings->custom_mounts; + arg_n_custom_mounts = settings->n_custom_mounts; + + settings->custom_mounts = NULL; + settings->n_custom_mounts = 0; + } + } + + if ((arg_settings_mask & SETTING_NETWORK) == 0 && + (settings->private_network >= 0 || + settings->network_veth >= 0 || + settings->network_bridge || + settings->network_zone || + settings->network_interfaces || + settings->network_macvlan || + settings->network_ipvlan || + settings->network_veth_extra)) { + + if (!arg_settings_trusted) + log_warning("Ignoring network settings, file %s is not trusted.", p); + else { + arg_network_veth = settings_network_veth(settings); + arg_private_network = settings_private_network(settings); + + strv_free(arg_network_interfaces); + arg_network_interfaces = settings->network_interfaces; + settings->network_interfaces = NULL; + + strv_free(arg_network_macvlan); + arg_network_macvlan = settings->network_macvlan; + settings->network_macvlan = NULL; + + strv_free(arg_network_ipvlan); + arg_network_ipvlan = settings->network_ipvlan; + settings->network_ipvlan = NULL; + + strv_free(arg_network_veth_extra); + arg_network_veth_extra = settings->network_veth_extra; + settings->network_veth_extra = NULL; + + free(arg_network_bridge); + arg_network_bridge = settings->network_bridge; + settings->network_bridge = NULL; + + free(arg_network_zone); + arg_network_zone = settings->network_zone; + settings->network_zone = NULL; + } + } + + 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.", p); + else { + expose_port_free_all(arg_expose_ports); + arg_expose_ports = settings->expose_ports; + settings->expose_ports = NULL; + } + } + + 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.", p); + else { + arg_userns_mode = settings->userns_mode; + arg_uid_shift = settings->uid_shift; + arg_uid_range = settings->uid_range; + arg_userns_chown = settings->userns_chown; + } + } + + if ((arg_settings_mask & SETTING_NOTIFY_READY) == 0) + arg_notify_ready = settings->notify_ready; + + return 0; +} + +static int run(int master, + const char* console, + const char *root_device, bool root_device_rw, + const char *home_device, bool home_device_rw, + const char *srv_device, bool srv_device_rw, + const char *esp_device, + bool interactive, + bool secondary, + FDSet *fds, + char veth_name[IFNAMSIZ], bool *veth_created, + union in_addr_union *exposed, + pid_t *pid, int *ret) { + + static const struct sigaction sa = { + .sa_handler = nop_signal_handler, + .sa_flags = SA_NOCLDSTOP, + }; + + _cleanup_release_lock_file_ LockFile uid_shift_lock = LOCK_FILE_INIT; + _cleanup_close_ int etc_passwd_lock = -1; + _cleanup_close_pair_ int + kmsg_socket_pair[2] = { -1, -1 }, + rtnl_socket_pair[2] = { -1, -1 }, + pid_socket_pair[2] = { -1, -1 }, + uuid_socket_pair[2] = { -1, -1 }, + notify_socket_pair[2] = { -1, -1 }, + uid_shift_socket_pair[2] = { -1, -1 }; + _cleanup_close_ int notify_socket= -1; + _cleanup_(barrier_destroy) Barrier barrier = BARRIER_NULL; + _cleanup_(sd_event_unrefp) sd_event *event = NULL; + _cleanup_(pty_forward_freep) PTYForward *forward = NULL; + _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL; + ContainerStatus container_status = 0; + char last_char = 0; + int ifi = 0, r; + ssize_t l; + sigset_t mask_chld; + + assert_se(sigemptyset(&mask_chld) == 0); + assert_se(sigaddset(&mask_chld, SIGCHLD) == 0); + + if (arg_userns_mode == USER_NAMESPACE_PICK) { + /* When we shall pick the UID/GID range, let's first lock /etc/passwd, so that we can safely + * check with getpwuid() if the specific user already exists. Note that /etc might be + * read-only, in which case this will fail with EROFS. But that's really OK, as in that case we + * can be reasonably sure that no users are going to be added. Note that getpwuid() checks are + * really just an extra safety net. We kinda assume that the UID range we allocate from is + * really ours. */ + + etc_passwd_lock = take_etc_passwd_lock(NULL); + if (etc_passwd_lock < 0 && etc_passwd_lock != -EROFS) + return log_error_errno(etc_passwd_lock, "Failed to take /etc/passwd lock: %m"); + } + + r = barrier_create(&barrier); + if (r < 0) + return log_error_errno(r, "Cannot initialize IPC barrier: %m"); + + if (socketpair(AF_UNIX, SOCK_SEQPACKET|SOCK_CLOEXEC, 0, kmsg_socket_pair) < 0) + return log_error_errno(errno, "Failed to create kmsg socket pair: %m"); + + if (socketpair(AF_UNIX, SOCK_SEQPACKET|SOCK_CLOEXEC, 0, rtnl_socket_pair) < 0) + return log_error_errno(errno, "Failed to create rtnl socket pair: %m"); + + if (socketpair(AF_UNIX, SOCK_SEQPACKET|SOCK_CLOEXEC, 0, pid_socket_pair) < 0) + return log_error_errno(errno, "Failed to create pid socket pair: %m"); + + if (socketpair(AF_UNIX, SOCK_SEQPACKET|SOCK_CLOEXEC, 0, uuid_socket_pair) < 0) + return log_error_errno(errno, "Failed to create id socket pair: %m"); + + if (socketpair(AF_UNIX, SOCK_SEQPACKET|SOCK_CLOEXEC, 0, notify_socket_pair) < 0) + return log_error_errno(errno, "Failed to create notify socket pair: %m"); + + if (arg_userns_mode != USER_NAMESPACE_NO) + if (socketpair(AF_UNIX, SOCK_SEQPACKET|SOCK_CLOEXEC, 0, uid_shift_socket_pair) < 0) + return log_error_errno(errno, "Failed to create uid shift socket pair: %m"); + + /* 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"); + + *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); + + master = safe_close(master); + + kmsg_socket_pair[0] = safe_close(kmsg_socket_pair[0]); + rtnl_socket_pair[0] = safe_close(rtnl_socket_pair[0]); + pid_socket_pair[0] = safe_close(pid_socket_pair[0]); + uuid_socket_pair[0] = safe_close(uuid_socket_pair[0]); + notify_socket_pair[0] = safe_close(notify_socket_pair[0]); + uid_shift_socket_pair[0] = safe_close(uid_shift_socket_pair[0]); + + (void) reset_all_signal_handlers(); + (void) reset_signal_mask(); + + r = outer_child(&barrier, + arg_directory, + console, + root_device, root_device_rw, + home_device, home_device_rw, + srv_device, srv_device_rw, + esp_device, + interactive, + secondary, + pid_socket_pair[1], + uuid_socket_pair[1], + notify_socket_pair[1], + kmsg_socket_pair[1], + rtnl_socket_pair[1], + uid_shift_socket_pair[1], + fds); + if (r < 0) + _exit(EXIT_FAILURE); + + _exit(EXIT_SUCCESS); + } + + barrier_set_role(&barrier, BARRIER_PARENT); + + fds = fdset_free(fds); + + kmsg_socket_pair[1] = safe_close(kmsg_socket_pair[1]); + rtnl_socket_pair[1] = safe_close(rtnl_socket_pair[1]); + pid_socket_pair[1] = safe_close(pid_socket_pair[1]); + uuid_socket_pair[1] = safe_close(uuid_socket_pair[1]); + notify_socket_pair[1] = safe_close(notify_socket_pair[1]); + uid_shift_socket_pair[1] = safe_close(uid_shift_socket_pair[1]); + + if (arg_userns_mode != USER_NAMESPACE_NO) { + /* The child just let us know the UID shift it might have read from the image. */ + l = recv(uid_shift_socket_pair[0], &arg_uid_shift, sizeof arg_uid_shift, 0); + if (l < 0) + return log_error_errno(errno, "Failed to read UID shift: %m"); + + if (l != sizeof arg_uid_shift) { + log_error("Short read while reading UID shift."); + return -EIO; + } + + if (arg_userns_mode == USER_NAMESPACE_PICK) { + /* If we are supposed to pick the UID shift, let's try to use the shift read from the + * image, but if that's already in use, pick a new one, and report back to the child, + * which one we now picked. */ + + r = uid_shift_pick(&arg_uid_shift, &uid_shift_lock); + if (r < 0) + return log_error_errno(r, "Failed to pick suitable UID/GID range: %m"); + + l = send(uid_shift_socket_pair[0], &arg_uid_shift, sizeof arg_uid_shift, MSG_NOSIGNAL); + if (l < 0) + return log_error_errno(errno, "Failed to send UID shift: %m"); + if (l != sizeof arg_uid_shift) { + log_error("Short write while writing UID shift."); + return -EIO; + } + } + } + + /* Wait for the outer child. */ + r = wait_for_terminate_and_warn("namespace helper", *pid, NULL); + if (r != 0) + return r < 0 ? r : -EIO; + + /* And now retrieve the PID of the inner child. */ + l = recv(pid_socket_pair[0], pid, sizeof *pid, 0); + if (l < 0) + return log_error_errno(errno, "Failed to read inner child PID: %m"); + if (l != sizeof *pid) { + log_error("Short read while reading inner child PID."); + return -EIO; + } + + /* We also retrieve container UUID in case it was generated by outer child */ + l = recv(uuid_socket_pair[0], &arg_uuid, sizeof arg_uuid, 0); + if (l < 0) + return log_error_errno(errno, "Failed to read container machine ID: %m"); + if (l != sizeof(arg_uuid)) { + log_error("Short read while reading container machined ID."); + return -EIO; + } + + /* We also retrieve the socket used for notifications generated by outer child */ + notify_socket = receive_one_fd(notify_socket_pair[0], 0); + if (notify_socket < 0) + return log_error_errno(notify_socket, + "Failed to receive notification socket from the outer child: %m"); + + log_debug("Init process invoked as PID "PID_FMT, *pid); + + if (arg_userns_mode != USER_NAMESPACE_NO) { + if (!barrier_place_and_sync(&barrier)) { /* #1 */ + log_error("Child died too early."); + return -ESRCH; + } + + r = setup_uid_map(*pid); + if (r < 0) + return r; + + (void) barrier_place(&barrier); /* #2 */ + } + + if (arg_private_network) { + + r = move_network_interfaces(*pid, arg_network_interfaces); + if (r < 0) + return r; + + if (arg_network_veth) { + r = setup_veth(arg_machine, *pid, veth_name, + arg_network_bridge || arg_network_zone); + if (r < 0) + return r; + else if (r > 0) + ifi = r; + + if (arg_network_bridge) { + /* Add the interface to a bridge */ + r = setup_bridge(veth_name, arg_network_bridge, false); + if (r < 0) + return r; + if (r > 0) + ifi = r; + } else if (arg_network_zone) { + /* Add the interface to a bridge, possibly creating it */ + r = setup_bridge(veth_name, arg_network_zone, true); + if (r < 0) + return r; + if (r > 0) + ifi = r; + } + } + + r = setup_veth_extra(arg_machine, *pid, arg_network_veth_extra); + if (r < 0) + return r; + + /* We created the primary and extra veth links now; let's remember this, so that we know to + remove them later on. Note that we don't bother with removing veth links that were created + here when their setup failed half-way, because in that case the kernel should be able to + remove them on its own, since they cannot be referenced by anything yet. */ + *veth_created = true; + + r = setup_macvlan(arg_machine, *pid, arg_network_macvlan); + if (r < 0) + return r; + + r = setup_ipvlan(arg_machine, *pid, arg_network_ipvlan); + if (r < 0) + return r; + } + + if (arg_register) { + r = register_machine( + arg_machine, + *pid, + arg_directory, + arg_uuid, + ifi, + arg_slice, + arg_custom_mounts, arg_n_custom_mounts, + arg_kill_signal, + arg_property, + arg_keep_unit, + arg_container_service_name); + if (r < 0) + return r; + } + + r = sync_cgroup(*pid, arg_unified_cgroup_hierarchy, arg_uid_shift); + if (r < 0) + return r; + + if (arg_keep_unit) { + r = create_subcgroup(*pid, arg_unified_cgroup_hierarchy); + if (r < 0) + return r; + } + + r = chown_cgroup(*pid, 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); /* #3 */ + + /* 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, -1); + 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"); + + r = setup_sd_notify_parent(event, notify_socket, PID_TO_PTR(*pid)); + if (r < 0) + return r; + + /* Let the child know that we are ready and wait that the child is completely ready now. */ + if (!barrier_place_and_sync(&barrier)) { /* #4 */ + log_error("Child died too early."); + return -ESRCH; + } + + /* At this point we have made use of the UID we picked, and thus nss-mymachines + * will make them appear in getpwuid(), thus we can release the /etc/passwd lock. */ + etc_passwd_lock = safe_close(etc_passwd_lock); + + sd_notifyf(false, + "STATUS=Container running.\n" + "X_NSPAWN_LEADER_PID=" PID_FMT, *pid); + if (!arg_notify_ready) + sd_notify(false, "READY=1\n"); + + if (arg_kill_signal > 0) { + /* Try to kill the init system on SIGINT or SIGTERM */ + sd_event_add_signal(event, NULL, SIGINT, on_orderly_shutdown, PID_TO_PTR(*pid)); + sd_event_add_signal(event, NULL, SIGTERM, on_orderly_shutdown, PID_TO_PTR(*pid)); + } else { + /* Immediately exit */ + sd_event_add_signal(event, NULL, SIGINT, NULL, NULL); + sd_event_add_signal(event, NULL, SIGTERM, NULL, NULL); + } + + /* simply exit on sigchld */ + sd_event_add_signal(event, NULL, SIGCHLD, NULL, NULL); + + if (arg_expose_ports) { + r = expose_port_watch_rtnl(event, rtnl_socket_pair[0], on_address_change, exposed, &rtnl); + if (r < 0) + return r; + + (void) expose_port_execute(rtnl, arg_expose_ports, exposed); + } + + rtnl_socket_pair[0] = safe_close(rtnl_socket_pair[0]); + + r = pty_forward_new(event, master, + PTY_FORWARD_IGNORE_VHANGUP | (interactive ? 0 : PTY_FORWARD_READ_ONLY), + &forward); + if (r < 0) + return log_error_errno(r, "Failed to create PTY forwarder: %m"); + + r = sd_event_loop(event); + if (r < 0) + return log_error_errno(r, "Failed to run event loop: %m"); + + 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) + terminate_machine(*pid); + + /* Normally redundant, but better safe than sorry */ + kill(*pid, SIGKILL); + + r = wait_for_container(*pid, &container_status); + *pid = 0; + + 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 == 133) + 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 = 0; + return 133; + } + + expose_port_flush(arg_expose_ports, exposed); + + (void) remove_veth_links(veth_name, arg_network_veth_extra); + *veth_created = false; + return 1; /* loop again */ +} + +int main(int argc, char *argv[]) { + + _cleanup_free_ char *device_path = NULL, *root_device = NULL, *home_device = NULL, *srv_device = NULL, *esp_device = NULL, *console = NULL; + bool root_device_rw = true, home_device_rw = true, srv_device_rw = true; + _cleanup_close_ int master = -1, image_fd = -1; + _cleanup_fdset_free_ FDSet *fds = NULL; + int r, n_fd_passed, loop_nr = -1, ret = EXIT_SUCCESS; + char veth_name[IFNAMSIZ] = ""; + bool secondary = false, remove_subvol = false; + pid_t pid = 0; + union in_addr_union exposed = {}; + _cleanup_release_lock_file_ LockFile tree_global_lock = LOCK_FILE_INIT, tree_local_lock = LOCK_FILE_INIT; + bool interactive, veth_created = false; + + log_parse_environment(); + log_open(); + + /* Make sure rename_process() in the stub init process can work */ + saved_argv = argv; + saved_argc = argc; + + r = parse_argv(argc, argv); + if (r <= 0) + goto finish; + + if (geteuid() != 0) { + log_error("Need to be root."); + r = -EPERM; + goto finish; + } + r = determine_names(); + if (r < 0) + goto finish; + + r = load_settings(); + if (r < 0) + goto finish; + + r = verify_arguments(); + if (r < 0) + goto finish; + + 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; + } + } + + if (arg_directory) { + assert(!arg_image); + + if (path_equal(arg_directory, "/") && !arg_ephemeral) { + log_error("Spawning container on root directory is not supported. Consider using --ephemeral."); + r = -EINVAL; + goto finish; + } + + if (arg_ephemeral) { + _cleanup_free_ char *np = NULL; + + /* 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, 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 snapshot: %m"); + goto finish; + } + + r = image_path_lock(np, (arg_read_only ? LOCK_SH : 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; + } + + r = btrfs_subvol_snapshot(arg_directory, np, (arg_read_only ? BTRFS_SNAPSHOT_READ_ONLY : 0) | BTRFS_SNAPSHOT_FALLBACK_COPY | BTRFS_SNAPSHOT_RECURSIVE | BTRFS_SNAPSHOT_QUOTA); + if (r < 0) { + log_error_errno(r, "Failed to create snapshot %s from %s: %m", np, arg_directory); + goto finish; + } + + free(arg_directory); + arg_directory = np; + np = NULL; + + remove_subvol = true; + + } else { + 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 = btrfs_subvol_snapshot(arg_template, arg_directory, (arg_read_only ? BTRFS_SNAPSHOT_READ_ONLY : 0) | BTRFS_SNAPSHOT_FALLBACK_COPY | BTRFS_SNAPSHOT_RECURSIVE | BTRFS_SNAPSHOT_QUOTA); + if (r == -EEXIST) { + if (!arg_quiet) + log_info("Directory %s already exists, not populating from template %s.", arg_directory, arg_template); + } else if (r < 0) { + log_error_errno(r, "Couldn't create snapshot %s from %s: %m", arg_directory, arg_template); + goto finish; + } else { + if (!arg_quiet) + log_info("Populated %s from template %s.", arg_directory, arg_template); + } + } + } + + if (arg_start_mode == START_BOOT) { + if (path_is_os_tree(arg_directory) <= 0) { + log_error("Directory %s doesn't look like an OS root directory (os-release file is missing). Refusing.", arg_directory); + r = -EINVAL; + goto finish; + } + } else { + const char *p; + + p = strjoina(arg_directory, "/usr/"); + if (laccess(p, F_OK) < 0) { + log_error("Directory %s doesn't look like it has an OS tree. Refusing.", arg_directory); + r = -EINVAL; + goto finish; + } + } + + } else { + char template[] = "/tmp/nspawn-root-XXXXXX"; + + assert(arg_image); + assert(!arg_template); + + 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; + } + + if (!mkdtemp(template)) { + log_error_errno(errno, "Failed to create temporary directory: %m"); + r = -errno; + goto finish; + } + + arg_directory = strdup(template); + if (!arg_directory) { + r = log_oom(); + goto finish; + } + + image_fd = setup_image(&device_path, &loop_nr); + if (image_fd < 0) { + r = image_fd; + goto finish; + } + + r = dissect_image(image_fd, + &root_device, &root_device_rw, + &home_device, &home_device_rw, + &srv_device, &srv_device_rw, + &esp_device, + &secondary); + if (r < 0) + goto finish; + } + + r = custom_mounts_prepare(); + if (r < 0) + goto finish; + + interactive = + isatty(STDIN_FILENO) > 0 && + isatty(STDOUT_FILENO) > 0; + + master = posix_openpt(O_RDWR|O_NOCTTY|O_CLOEXEC|O_NDELAY); + if (master < 0) { + r = log_error_errno(errno, "Failed to acquire pseudo tty: %m"); + goto finish; + } + + r = ptsname_malloc(master, &console); + if (r < 0) { + r = log_error_errno(r, "Failed to determine tty name: %m"); + goto finish; + } + + if (arg_selinux_apifs_context) { + r = mac_selinux_apply(console, arg_selinux_apifs_context); + if (r < 0) + goto finish; + } + + if (unlockpt(master) < 0) { + r = log_error_errno(errno, "Failed to unlock tty: %m"); + goto finish; + } + + if (!arg_quiet) + log_info("Spawning container %s on %s.\nPress ^] three times within 1s to kill container.", + arg_machine, arg_image ?: arg_directory); + + assert_se(sigprocmask_many(SIG_BLOCK, NULL, SIGCHLD, SIGWINCH, SIGTERM, SIGINT, -1) >= 0); + + if (prctl(PR_SET_CHILD_SUBREAPER, 1) < 0) { + r = log_error_errno(errno, "Failed to become subreaper: %m"); + goto finish; + } + + for (;;) { + r = run(master, + console, + root_device, root_device_rw, + home_device, home_device_rw, + srv_device, srv_device_rw, + esp_device, + interactive, secondary, + fds, + veth_name, &veth_created, + &exposed, + &pid, &ret); + if (r <= 0) + break; + } + +finish: + sd_notify(false, + "STOPPING=1\n" + "STATUS=Terminating..."); + + if (pid > 0) + kill(pid, SIGKILL); + + /* Try to flush whatever is still queued in the pty */ + if (master >= 0) + (void) copy_bytes(master, STDOUT_FILENO, (uint64_t) -1, false); + + loop_remove(loop_nr, &image_fd); + + if (remove_subvol && arg_directory) { + int k; + + k = btrfs_subvol_remove(arg_directory, BTRFS_REMOVE_RECURSIVE|BTRFS_REMOVE_QUOTA); + if (k < 0) + log_warning_errno(k, "Cannot remove subvolume '%s', ignoring: %m", arg_directory); + } + + if (arg_machine) { + const char *p; + + p = strjoina("/run/systemd/nspawn/propagate/", arg_machine); + (void) rm_rf(p, REMOVE_ROOT); + } + + expose_port_flush(arg_expose_ports, &exposed); + + if (veth_created) + (void) remove_veth_links(veth_name, arg_network_veth_extra); + (void) remove_bridge(arg_network_zone); + + free(arg_directory); + free(arg_template); + free(arg_image); + free(arg_machine); + free(arg_user); + free(arg_chdir); + strv_free(arg_setenv); + free(arg_network_bridge); + strv_free(arg_network_interfaces); + strv_free(arg_network_macvlan); + strv_free(arg_network_ipvlan); + strv_free(arg_network_veth_extra); + strv_free(arg_parameters); + custom_mount_free_all(arg_custom_mounts, arg_n_custom_mounts); + expose_port_free_all(arg_expose_ports); + + return r < 0 ? EXIT_FAILURE : ret; +} |