1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
4 This file is part of systemd.
6 Copyright 2010 Lennart Poettering
8 systemd is free software; you can redistribute it and/or modify it
9 under the terms of the GNU Lesser General Public License as published by
10 the Free Software Foundation; either version 2.1 of the License, or
11 (at your option) any later version.
13 systemd is distributed in the hope that it will be useful, but
14 WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 Lesser General Public License for more details.
18 You should have received a copy of the GNU Lesser General Public License
19 along with systemd; If not, see <http://www.gnu.org/licenses/>.
25 #include <sys/types.h>
26 #include <sys/syscall.h>
27 #include <sys/mount.h>
33 #include <sys/prctl.h>
34 #include <sys/capability.h>
36 #include <sys/epoll.h>
38 #include <sys/signalfd.h>
42 #include <sys/socket.h>
44 #include <systemd/sd-daemon.h>
52 #include "cgroup-util.h"
54 #include "path-util.h"
55 #include "loopback-setup.h"
57 #include "dev-setup.h"
61 typedef enum LinkJournal {
68 static char *arg_directory = NULL;
69 static char *arg_user = NULL;
70 static char **arg_controllers = NULL;
71 static char *arg_uuid = NULL;
72 static bool arg_private_network = false;
73 static bool arg_read_only = false;
74 static bool arg_boot = false;
75 static LinkJournal arg_link_journal = LINK_AUTO;
76 static uint64_t arg_retain =
78 (1ULL << CAP_DAC_OVERRIDE) |
79 (1ULL << CAP_DAC_READ_SEARCH) |
80 (1ULL << CAP_FOWNER) |
81 (1ULL << CAP_FSETID) |
82 (1ULL << CAP_IPC_OWNER) |
85 (1ULL << CAP_LINUX_IMMUTABLE) |
86 (1ULL << CAP_NET_BIND_SERVICE) |
87 (1ULL << CAP_NET_BROADCAST) |
88 (1ULL << CAP_NET_RAW) |
89 (1ULL << CAP_SETGID) |
90 (1ULL << CAP_SETFCAP) |
91 (1ULL << CAP_SETPCAP) |
92 (1ULL << CAP_SETUID) |
93 (1ULL << CAP_SYS_ADMIN) |
94 (1ULL << CAP_SYS_CHROOT) |
95 (1ULL << CAP_SYS_NICE) |
96 (1ULL << CAP_SYS_PTRACE) |
97 (1ULL << CAP_SYS_TTY_CONFIG) |
98 (1ULL << CAP_SYS_RESOURCE) |
99 (1ULL << CAP_SYS_BOOT) |
100 (1ULL << CAP_AUDIT_WRITE) |
101 (1ULL << CAP_AUDIT_CONTROL);
103 static int help(void) {
105 printf("%s [OPTIONS...] [PATH] [ARGUMENTS...]\n\n"
106 "Spawn a minimal namespace container for debugging, testing and building.\n\n"
107 " -h --help Show this help\n"
108 " --version Print version string\n"
109 " -D --directory=NAME Root directory for the container\n"
110 " -b --boot Boot up full system (i.e. invoke init)\n"
111 " -u --user=USER Run the command under specified user or uid\n"
112 " -C --controllers=LIST Put the container in specified comma-separated cgroup hierarchies\n"
113 " --uuid=UUID Set a specific machine UUID for the container\n"
114 " --private-network Disable network in container\n"
115 " --read-only Mount the root directory read-only\n"
116 " --capability=CAP In addition to the default, retain specified capability\n"
117 " --link-journal=MODE Link up guest journal, one of no, auto, guest, host\n"
118 " -j Equivalent to --link-journal=host\n",
119 program_invocation_short_name);
124 static int parse_argv(int argc, char *argv[]) {
135 static const struct option options[] = {
136 { "help", no_argument, NULL, 'h' },
137 { "version", no_argument, NULL, ARG_VERSION },
138 { "directory", required_argument, NULL, 'D' },
139 { "user", required_argument, NULL, 'u' },
140 { "controllers", required_argument, NULL, 'C' },
141 { "private-network", no_argument, NULL, ARG_PRIVATE_NETWORK },
142 { "boot", no_argument, NULL, 'b' },
143 { "uuid", required_argument, NULL, ARG_UUID },
144 { "read-only", no_argument, NULL, ARG_READ_ONLY },
145 { "capability", required_argument, NULL, ARG_CAPABILITY },
146 { "link-journal", required_argument, NULL, ARG_LINK_JOURNAL },
155 while ((c = getopt_long(argc, argv, "+hD:u:C:bj", options, NULL)) >= 0) {
164 puts(PACKAGE_STRING);
165 puts(SYSTEMD_FEATURES);
170 arg_directory = canonicalize_file_name(optarg);
171 if (!arg_directory) {
172 log_error("Failed to canonicalize root directory.");
180 if (!(arg_user = strdup(optarg))) {
181 log_error("Failed to duplicate user name.");
188 strv_free(arg_controllers);
189 arg_controllers = strv_split(optarg, ",");
190 if (!arg_controllers) {
191 log_error("Failed to split controllers list.");
194 strv_uniq(arg_controllers);
198 case ARG_PRIVATE_NETWORK:
199 arg_private_network = true;
211 arg_read_only = true;
214 case ARG_CAPABILITY: {
218 FOREACH_WORD_SEPARATOR(word, length, optarg, ",", state) {
222 t = strndup(word, length);
226 if (cap_from_name(t, &cap) < 0) {
227 log_error("Failed to parse capability %s.", t);
233 arg_retain |= 1ULL << (uint64_t) cap;
240 arg_link_journal = LINK_GUEST;
243 case ARG_LINK_JOURNAL:
244 if (streq(optarg, "auto"))
245 arg_link_journal = LINK_AUTO;
246 else if (streq(optarg, "no"))
247 arg_link_journal = LINK_NO;
248 else if (streq(optarg, "guest"))
249 arg_link_journal = LINK_GUEST;
250 else if (streq(optarg, "host"))
251 arg_link_journal = LINK_HOST;
253 log_error("Failed to parse link journal mode %s", optarg);
263 log_error("Unknown option code %c", c);
271 static int mount_all(const char *dest) {
273 typedef struct MountPoint {
282 static const MountPoint mount_table[] = {
283 { "proc", "/proc", "proc", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV, true },
284 { "/proc/sys", "/proc/sys", NULL, NULL, MS_BIND, true }, /* Bind mount first */
285 { NULL, "/proc/sys", NULL, NULL, MS_BIND|MS_RDONLY|MS_REMOUNT, true }, /* Then, make it r/o */
286 { "sysfs", "/sys", "sysfs", NULL, MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV, true },
287 { "tmpfs", "/dev", "tmpfs", "mode=755", MS_NOSUID|MS_STRICTATIME, true },
288 { "/dev/pts", "/dev/pts", NULL, NULL, MS_BIND, true },
289 { "tmpfs", "/dev/shm", "tmpfs", "mode=1777", MS_NOSUID|MS_NODEV|MS_STRICTATIME, true },
290 { "tmpfs", "/run", "tmpfs", "mode=755", MS_NOSUID|MS_NODEV|MS_STRICTATIME, true },
292 { "/sys/fs/selinux", "/sys/fs/selinux", NULL, NULL, MS_BIND, false }, /* Bind mount first */
293 { NULL, "/sys/fs/selinux", NULL, NULL, MS_BIND|MS_RDONLY|MS_REMOUNT, false }, /* Then, make it r/o */
300 for (k = 0; k < ELEMENTSOF(mount_table); k++) {
301 char _cleanup_free_ *where = NULL;
304 if (asprintf(&where, "%s/%s", dest, mount_table[k].where) < 0) {
313 t = path_is_mount_point(where, true);
315 log_error("Failed to detect whether %s is a mount point: %s", where, strerror(-t));
323 /* Skip this entry if it is not a remount. */
324 if (mount_table[k].what && t > 0)
327 mkdir_p_label(where, 0755);
329 if (mount(mount_table[k].what,
332 mount_table[k].flags,
333 mount_table[k].options) < 0 &&
334 mount_table[k].fatal) {
336 log_error("mount(%s) failed: %m", where);
346 static int setup_timezone(const char *dest) {
347 _cleanup_free_ char *where = NULL, *p = NULL, *q = NULL, *check = NULL, *what = NULL;
353 /* Fix the timezone, if possible */
354 r = readlink_malloc("/etc/localtime", &p);
356 log_warning("/etc/localtime is not a symlink, not updating container timezone.");
360 z = path_startswith(p, "../usr/share/zoneinfo/");
362 z = path_startswith(p, "/usr/share/zoneinfo/");
364 log_warning("/etc/localtime does not point into /usr/share/zoneinfo/, not updating container timezone.");
368 where = strappend(dest, "/etc/localtime");
372 r = readlink_malloc(where, &q);
374 y = path_startswith(q, "../usr/share/zoneinfo/");
376 y = path_startswith(q, "/usr/share/zoneinfo/");
379 /* Already pointing to the right place? Then do nothing .. */
380 if (y && streq(y, z))
384 check = strjoin(dest, "/usr/share/zoneinfo/", z, NULL);
388 if (access(check, F_OK) < 0) {
389 log_warning("Timezone %s does not exist in container, not updating container timezone.", z);
393 what = strappend("../usr/share/zoneinfo/", z);
398 if (symlink(what, where) < 0) {
399 log_error("Failed to correct timezone of container: %m");
406 static int setup_resolv_conf(const char *dest) {
411 if (arg_private_network)
414 /* Fix resolv.conf, if possible */
415 where = strappend(dest, "/etc/resolv.conf");
419 /* We don't really care for the results of this really. If it
420 * fails, it fails, but meh... */
421 if (mount("/etc/resolv.conf", where, "bind", MS_BIND, NULL) >= 0)
422 mount("/etc/resolv.conf", where, "bind", MS_BIND|MS_REMOUNT|MS_RDONLY, NULL);
429 static int setup_boot_id(const char *dest) {
430 char _cleanup_free_ *from = NULL, *to = NULL;
437 /* Generate a new randomized boot ID, so that each boot-up of
438 * the container gets a new one */
440 from = strappend(dest, "/dev/proc-sys-kernel-random-boot-id");
441 to = strappend(dest, "/proc/sys/kernel/random/boot_id");
445 r = sd_id128_randomize(&rnd);
447 log_error("Failed to generate random boot id: %s", strerror(-r));
451 snprintf(as_uuid, sizeof(as_uuid),
452 "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
453 SD_ID128_FORMAT_VAL(rnd));
454 char_array_0(as_uuid);
456 r = write_one_line_file(from, as_uuid);
458 log_error("Failed to write boot id: %s", strerror(-r));
462 if (mount(from, to, "bind", MS_BIND, NULL) < 0) {
463 log_error("Failed to bind mount boot id: %m");
466 mount(from, to, "bind", MS_BIND|MS_REMOUNT|MS_RDONLY, NULL);
472 static int copy_devnodes(const char *dest) {
474 static const char devnodes[] =
485 mode_t _cleanup_umask_ u;
491 NULSTR_FOREACH(d, devnodes) {
493 char _cleanup_free_ *from = NULL, *to = NULL;
495 asprintf(&from, "/dev/%s", d);
496 asprintf(&to, "%s/dev/%s", dest, d);
507 if (stat(from, &st) < 0) {
509 if (errno != ENOENT) {
510 log_error("Failed to stat %s: %m", from);
515 } else if (!S_ISCHR(st.st_mode) && !S_ISBLK(st.st_mode)) {
517 log_error("%s is not a char or block device, cannot copy", from);
521 } else if (mknod(to, st.st_mode, st.st_rdev) < 0) {
523 log_error("mknod(%s) failed: %m", dest);
532 static int setup_dev_console(const char *dest, const char *console) {
534 char _cleanup_free_ *to = NULL;
536 mode_t _cleanup_umask_ u;
543 if (stat(console, &st) < 0) {
544 log_error("Failed to stat %s: %m", console);
547 } else if (!S_ISCHR(st.st_mode)) {
548 log_error("/dev/console is not a char device");
552 r = chmod_and_chown(console, 0600, 0, 0);
554 log_error("Failed to correct access mode for TTY: %s", strerror(-r));
558 if (asprintf(&to, "%s/dev/console", dest) < 0)
561 /* We need to bind mount the right tty to /dev/console since
562 * ptys can only exist on pts file systems. To have something
563 * to bind mount things on we create a device node first, that
564 * has the right major/minor (note that the major minor
565 * doesn't actually matter here, since we mount it over
568 if (mknod(to, (st.st_mode & ~07777) | 0600, st.st_rdev) < 0) {
569 log_error("mknod() for /dev/console failed: %m");
573 if (mount(console, to, "bind", MS_BIND, NULL) < 0) {
574 log_error("Bind mount for /dev/console failed: %m");
581 static int setup_kmsg(const char *dest, int kmsg_socket) {
582 char _cleanup_free_ *from = NULL, *to = NULL;
584 mode_t _cleanup_umask_ u;
586 struct cmsghdr cmsghdr;
587 uint8_t buf[CMSG_SPACE(sizeof(int))];
590 struct cmsghdr *cmsg;
593 assert(kmsg_socket >= 0);
597 /* We create the kmsg FIFO as /dev/kmsg, but immediately
598 * delete it after bind mounting it to /proc/kmsg. While FIFOs
599 * on the reading side behave very similar to /proc/kmsg,
600 * their writing side behaves differently from /dev/kmsg in
601 * that writing blocks when nothing is reading. In order to
602 * avoid any problems with containers deadlocking due to this
603 * we simply make /dev/kmsg unavailable to the container. */
604 if (asprintf(&from, "%s/dev/kmsg", dest) < 0 ||
605 asprintf(&to, "%s/proc/kmsg", dest) < 0)
608 if (mkfifo(from, 0600) < 0) {
609 log_error("mkfifo() for /dev/kmsg failed: %m");
613 r = chmod_and_chown(from, 0600, 0, 0);
615 log_error("Failed to correct access mode for /dev/kmsg: %s", strerror(-r));
619 if (mount(from, to, "bind", MS_BIND, NULL) < 0) {
620 log_error("Bind mount for /proc/kmsg failed: %m");
624 fd = open(from, O_RDWR|O_NDELAY|O_CLOEXEC);
626 log_error("Failed to open fifo: %m");
633 mh.msg_control = &control;
634 mh.msg_controllen = sizeof(control);
636 cmsg = CMSG_FIRSTHDR(&mh);
637 cmsg->cmsg_level = SOL_SOCKET;
638 cmsg->cmsg_type = SCM_RIGHTS;
639 cmsg->cmsg_len = CMSG_LEN(sizeof(int));
640 memcpy(CMSG_DATA(cmsg), &fd, sizeof(int));
642 mh.msg_controllen = cmsg->cmsg_len;
644 /* Store away the fd in the socket, so that it stays open as
645 * long as we run the child */
646 k = sendmsg(kmsg_socket, &mh, MSG_DONTWAIT|MSG_NOSIGNAL);
647 close_nointr_nofail(fd);
650 log_error("Failed to send FIFO fd: %m");
654 /* And now make the FIFO unavailable as /dev/kmsg... */
659 static int setup_hostname(void) {
663 hn = path_get_file_name(arg_directory);
669 hostname_cleanup(hn);
672 if (sethostname(hn, strlen(hn)) < 0)
681 static int setup_journal(const char *directory) {
682 sd_id128_t machine_id;
683 char _cleanup_free_ *p = NULL, *b = NULL, *q = NULL, *d = NULL;
687 if (arg_link_journal == LINK_NO)
690 p = strappend(directory, "/etc/machine-id");
694 r = read_one_line_file(p, &b);
695 if (r == -ENOENT && arg_link_journal == LINK_AUTO)
698 log_error("Failed to read machine ID from %s: %s", p, strerror(-r));
703 if (isempty(id) && arg_link_journal == LINK_AUTO)
706 /* Verify validity */
707 r = sd_id128_from_string(id, &machine_id);
709 log_error("Failed to parse machine ID from %s: %s", p, strerror(-r));
714 p = strappend("/var/log/journal/", id);
715 q = strjoin(directory, "/var/log/journal/", id, NULL);
719 if (path_is_mount_point(p, false) > 0) {
720 if (arg_link_journal != LINK_AUTO) {
721 log_error("%s: already a mount point, refusing to use for journal", p);
728 if (path_is_mount_point(q, false) > 0) {
729 if (arg_link_journal != LINK_AUTO) {
730 log_error("%s: already a mount point, refusing to use for journal", q);
737 r = readlink_and_make_absolute(p, &d);
739 if ((arg_link_journal == LINK_GUEST ||
740 arg_link_journal == LINK_AUTO) &&
743 r = mkdir_p(q, 0755);
745 log_warning("failed to create directory %s: %m", q);
750 log_error("Failed to remove symlink %s: %m", p);
753 } else if (r == -EINVAL) {
755 if (arg_link_journal == LINK_GUEST &&
758 if (errno == ENOTDIR) {
759 log_error("%s already exists and is neither a symlink nor a directory", p);
762 log_error("Failed to remove %s: %m", p);
766 } else if (r != -ENOENT) {
767 log_error("readlink(%s) failed: %m", p);
771 if (arg_link_journal == LINK_GUEST) {
773 if (symlink(q, p) < 0) {
774 log_error("Failed to symlink %s to %s: %m", q, p);
778 r = mkdir_p(q, 0755);
780 log_warning("failed to create directory %s: %m", q);
784 if (arg_link_journal == LINK_HOST) {
785 r = mkdir_p(p, 0755);
787 log_error("Failed to create %s: %m", p);
791 } else if (access(p, F_OK) < 0)
794 if (dir_is_empty(q) == 0) {
795 log_error("%s not empty.", q);
799 r = mkdir_p(q, 0755);
801 log_error("Failed to create %s: %m", q);
805 if (mount(p, q, "bind", MS_BIND, NULL) < 0) {
806 log_error("Failed to bind mount journal from host into guest: %m");
813 static int drop_capabilities(void) {
814 return capability_bounding_set_drop(~arg_retain, false);
817 static int is_os_tree(const char *path) {
820 /* We use /bin/sh as flag file if something is an OS */
822 if (asprintf(&p, "%s/bin/sh", path) < 0)
828 return r < 0 ? 0 : 1;
831 static int process_pty(int master, pid_t pid, sigset_t *mask) {
833 char in_buffer[LINE_MAX], out_buffer[LINE_MAX];
834 size_t in_buffer_full = 0, out_buffer_full = 0;
835 struct epoll_event stdin_ev, stdout_ev, master_ev, signal_ev;
836 bool stdin_readable = false, stdout_writable = false, master_readable = false, master_writable = false;
837 int ep = -1, signal_fd = -1, r;
838 bool tried_orderly_shutdown = false;
844 fd_nonblock(STDIN_FILENO, 1);
845 fd_nonblock(STDOUT_FILENO, 1);
846 fd_nonblock(master, 1);
848 signal_fd = signalfd(-1, mask, SFD_NONBLOCK|SFD_CLOEXEC);
850 log_error("signalfd(): %m");
855 ep = epoll_create1(EPOLL_CLOEXEC);
857 log_error("Failed to create epoll: %m");
862 /* We read from STDIN only if this is actually a TTY,
863 * otherwise we assume non-interactivity. */
864 if (isatty(STDIN_FILENO)) {
866 stdin_ev.events = EPOLLIN|EPOLLET;
867 stdin_ev.data.fd = STDIN_FILENO;
869 if (epoll_ctl(ep, EPOLL_CTL_ADD, STDIN_FILENO, &stdin_ev) < 0) {
870 log_error("Failed to register STDIN in epoll: %m");
877 stdout_ev.events = EPOLLOUT|EPOLLET;
878 stdout_ev.data.fd = STDOUT_FILENO;
881 master_ev.events = EPOLLIN|EPOLLOUT|EPOLLET;
882 master_ev.data.fd = master;
885 signal_ev.events = EPOLLIN;
886 signal_ev.data.fd = signal_fd;
888 if (epoll_ctl(ep, EPOLL_CTL_ADD, STDOUT_FILENO, &stdout_ev) < 0 ||
889 epoll_ctl(ep, EPOLL_CTL_ADD, master, &master_ev) < 0 ||
890 epoll_ctl(ep, EPOLL_CTL_ADD, signal_fd, &signal_ev) < 0) {
891 log_error("Failed to register fds in epoll: %m");
897 struct epoll_event ev[16];
901 nfds = epoll_wait(ep, ev, ELEMENTSOF(ev), -1);
904 if (errno == EINTR || errno == EAGAIN)
907 log_error("epoll_wait(): %m");
914 for (i = 0; i < nfds; i++) {
915 if (ev[i].data.fd == STDIN_FILENO) {
917 if (ev[i].events & (EPOLLIN|EPOLLHUP))
918 stdin_readable = true;
920 } else if (ev[i].data.fd == STDOUT_FILENO) {
922 if (ev[i].events & (EPOLLOUT|EPOLLHUP))
923 stdout_writable = true;
925 } else if (ev[i].data.fd == master) {
927 if (ev[i].events & (EPOLLIN|EPOLLHUP))
928 master_readable = true;
930 if (ev[i].events & (EPOLLOUT|EPOLLHUP))
931 master_writable = true;
933 } else if (ev[i].data.fd == signal_fd) {
934 struct signalfd_siginfo sfsi;
937 n = read(signal_fd, &sfsi, sizeof(sfsi));
938 if (n != sizeof(sfsi)) {
941 log_error("Failed to read from signalfd: invalid block size");
946 if (errno != EINTR && errno != EAGAIN) {
947 log_error("Failed to read from signalfd: %m");
953 if (sfsi.ssi_signo == SIGWINCH) {
956 /* The window size changed, let's forward that. */
957 if (ioctl(STDIN_FILENO, TIOCGWINSZ, &ws) >= 0)
958 ioctl(master, TIOCSWINSZ, &ws);
959 } else if (sfsi.ssi_signo == SIGTERM && arg_boot && !tried_orderly_shutdown) {
961 log_info("Trying to halt container. Send SIGTERM again to trigger immediate termination.");
963 /* This only works for systemd... */
964 tried_orderly_shutdown = true;
965 kill(pid, SIGRTMIN+3);
975 while ((stdin_readable && in_buffer_full <= 0) ||
976 (master_writable && in_buffer_full > 0) ||
977 (master_readable && out_buffer_full <= 0) ||
978 (stdout_writable && out_buffer_full > 0)) {
980 if (stdin_readable && in_buffer_full < LINE_MAX) {
982 k = read(STDIN_FILENO, in_buffer + in_buffer_full, LINE_MAX - in_buffer_full);
985 if (errno == EAGAIN || errno == EPIPE || errno == ECONNRESET || errno == EIO)
986 stdin_readable = false;
988 log_error("read(): %m");
993 in_buffer_full += (size_t) k;
996 if (master_writable && in_buffer_full > 0) {
998 k = write(master, in_buffer, in_buffer_full);
1001 if (errno == EAGAIN || errno == EPIPE || errno == ECONNRESET || errno == EIO)
1002 master_writable = false;
1004 log_error("write(): %m");
1010 assert(in_buffer_full >= (size_t) k);
1011 memmove(in_buffer, in_buffer + k, in_buffer_full - k);
1012 in_buffer_full -= k;
1016 if (master_readable && out_buffer_full < LINE_MAX) {
1018 k = read(master, out_buffer + out_buffer_full, LINE_MAX - out_buffer_full);
1021 if (errno == EAGAIN || errno == EPIPE || errno == ECONNRESET || errno == EIO)
1022 master_readable = false;
1024 log_error("read(): %m");
1029 out_buffer_full += (size_t) k;
1032 if (stdout_writable && out_buffer_full > 0) {
1034 k = write(STDOUT_FILENO, out_buffer, out_buffer_full);
1037 if (errno == EAGAIN || errno == EPIPE || errno == ECONNRESET || errno == EIO)
1038 stdout_writable = false;
1040 log_error("write(): %m");
1046 assert(out_buffer_full >= (size_t) k);
1047 memmove(out_buffer, out_buffer + k, out_buffer_full - k);
1048 out_buffer_full -= k;
1056 close_nointr_nofail(ep);
1059 close_nointr_nofail(signal_fd);
1064 int main(int argc, char *argv[]) {
1066 int r = EXIT_FAILURE, k;
1067 char *oldcg = NULL, *newcg = NULL;
1068 char **controller = NULL;
1069 int master = -1, n_fd_passed;
1070 const char *console = NULL;
1071 struct termios saved_attr, raw_attr;
1073 bool saved_attr_valid = false;
1075 int kmsg_socket_pair[2] = { -1, -1 };
1078 log_parse_environment();
1081 r = parse_argv(argc, argv);
1085 if (arg_directory) {
1088 p = path_make_absolute_cwd(arg_directory);
1089 free(arg_directory);
1092 arg_directory = get_current_dir_name();
1094 if (!arg_directory) {
1095 log_error("Failed to determine path");
1099 path_kill_slashes(arg_directory);
1101 if (geteuid() != 0) {
1102 log_error("Need to be root.");
1106 if (sd_booted() <= 0) {
1107 log_error("Not running on a systemd system.");
1111 if (path_equal(arg_directory, "/")) {
1112 log_error("Spawning container on root directory not supported.");
1116 if (is_os_tree(arg_directory) <= 0) {
1117 log_error("Directory %s doesn't look like an OS root directory. Refusing.", arg_directory);
1122 n_fd_passed = sd_listen_fds(false);
1123 if (n_fd_passed > 0) {
1124 k = fdset_new_listen_fds(&fds, false);
1126 log_error("Failed to collect file descriptors: %s", strerror(-k));
1130 fdset_close_others(fds);
1133 k = cg_get_by_pid(SYSTEMD_CGROUP_CONTROLLER, 0, &oldcg);
1135 log_error("Failed to determine current cgroup: %s", strerror(-k));
1139 if (asprintf(&newcg, "%s/nspawn-%lu", oldcg, (unsigned long) getpid()) < 0) {
1140 log_error("Failed to allocate cgroup path.");
1144 k = cg_create_and_attach(SYSTEMD_CGROUP_CONTROLLER, newcg, 0);
1146 log_error("Failed to create cgroup: %s", strerror(-k));
1150 STRV_FOREACH(controller, arg_controllers) {
1151 k = cg_create_and_attach(*controller, newcg, 0);
1153 log_warning("Failed to create cgroup in controller %s: %s", *controller, strerror(-k));
1156 master = posix_openpt(O_RDWR|O_NOCTTY|O_CLOEXEC|O_NDELAY);
1158 log_error("Failed to acquire pseudo tty: %m");
1162 console = ptsname(master);
1164 log_error("Failed to determine tty name: %m");
1168 log_info("Spawning namespace container on %s (console is %s).", arg_directory, console);
1170 if (ioctl(STDIN_FILENO, TIOCGWINSZ, &ws) >= 0)
1171 ioctl(master, TIOCSWINSZ, &ws);
1173 if (unlockpt(master) < 0) {
1174 log_error("Failed to unlock tty: %m");
1178 if (tcgetattr(STDIN_FILENO, &saved_attr) >= 0) {
1179 saved_attr_valid = true;
1181 raw_attr = saved_attr;
1182 cfmakeraw(&raw_attr);
1183 raw_attr.c_lflag &= ~ECHO;
1186 if (socketpair(AF_UNIX, SOCK_DGRAM|SOCK_NONBLOCK|SOCK_CLOEXEC, 0, kmsg_socket_pair) < 0) {
1187 log_error("Failed to create kmsg socket pair");
1191 assert_se(sigemptyset(&mask) == 0);
1192 sigset_add_many(&mask, SIGCHLD, SIGWINCH, SIGTERM, SIGINT, -1);
1193 assert_se(sigprocmask(SIG_BLOCK, &mask, NULL) == 0);
1198 if (saved_attr_valid) {
1199 if (tcsetattr(STDIN_FILENO, TCSANOW, &raw_attr) < 0) {
1200 log_error("Failed to set terminal attributes: %m");
1205 pid = syscall(__NR_clone, SIGCHLD|CLONE_NEWIPC|CLONE_NEWNS|CLONE_NEWPID|CLONE_NEWUTS|(arg_private_network ? CLONE_NEWNET : 0), NULL);
1207 if (errno == EINVAL)
1208 log_error("clone() failed, do you have namespace support enabled in your kernel? (You need UTS, IPC, PID and NET namespacing built in): %m");
1210 log_error("clone() failed: %m");
1218 const char *home = NULL;
1219 uid_t uid = (uid_t) -1;
1220 gid_t gid = (gid_t) -1;
1222 const char *envp[] = {
1223 "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
1224 "container=systemd-nspawn", /* LXC sets container=lxc, so follow the scheme here */
1229 NULL, /* container_uuid */
1230 NULL, /* LISTEN_FDS */
1231 NULL, /* LISTEN_PID */
1235 envp[2] = strv_find_prefix(environ, "TERM=");
1238 close_nointr_nofail(master);
1241 close_nointr(STDIN_FILENO);
1242 close_nointr(STDOUT_FILENO);
1243 close_nointr(STDERR_FILENO);
1245 close_nointr_nofail(kmsg_socket_pair[0]);
1246 kmsg_socket_pair[0] = -1;
1248 reset_all_signal_handlers();
1250 assert_se(sigemptyset(&mask) == 0);
1251 assert_se(sigprocmask(SIG_SETMASK, &mask, NULL) == 0);
1253 k = open_terminal(console, O_RDWR);
1254 if (k != STDIN_FILENO) {
1256 close_nointr_nofail(k);
1260 log_error("Failed to open console: %s", strerror(-k));
1264 if (dup2(STDIN_FILENO, STDOUT_FILENO) != STDOUT_FILENO ||
1265 dup2(STDIN_FILENO, STDERR_FILENO) != STDERR_FILENO) {
1266 log_error("Failed to duplicate console: %m");
1271 log_error("setsid() failed: %m");
1275 if (prctl(PR_SET_PDEATHSIG, SIGKILL) < 0) {
1276 log_error("PR_SET_PDEATHSIG failed: %m");
1280 /* Mark everything as slave, so that we still
1281 * receive mounts from the real root, but don't
1282 * propagate mounts to the real root. */
1283 if (mount(NULL, "/", NULL, MS_SLAVE|MS_REC, NULL) < 0) {
1284 log_error("MS_SLAVE|MS_REC failed: %m");
1288 /* Turn directory into bind mount */
1289 if (mount(arg_directory, arg_directory, "bind", MS_BIND|MS_REC, NULL) < 0) {
1290 log_error("Failed to make bind mount.");
1295 if (mount(arg_directory, arg_directory, "bind", MS_BIND|MS_REMOUNT|MS_RDONLY|MS_REC, NULL) < 0) {
1296 log_error("Failed to make read-only.");
1300 if (mount_all(arg_directory) < 0)
1303 if (copy_devnodes(arg_directory) < 0)
1306 dev_setup(arg_directory);
1308 if (setup_dev_console(arg_directory, console) < 0)
1311 if (setup_kmsg(arg_directory, kmsg_socket_pair[1]) < 0)
1314 close_nointr_nofail(kmsg_socket_pair[1]);
1315 kmsg_socket_pair[1] = -1;
1317 if (setup_boot_id(arg_directory) < 0)
1320 if (setup_timezone(arg_directory) < 0)
1323 if (setup_resolv_conf(arg_directory) < 0)
1326 if (setup_journal(arg_directory) < 0)
1329 if (chdir(arg_directory) < 0) {
1330 log_error("chdir(%s) failed: %m", arg_directory);
1334 if (mount(arg_directory, "/", NULL, MS_MOVE, NULL) < 0) {
1335 log_error("mount(MS_MOVE) failed: %m");
1339 if (chroot(".") < 0) {
1340 log_error("chroot() failed: %m");
1344 if (chdir("/") < 0) {
1345 log_error("chdir() failed: %m");
1353 if (drop_capabilities() < 0) {
1354 log_error("drop_capabilities() failed: %m");
1360 /* Note that this resolves user names
1361 * inside the container, and hence
1362 * accesses the NSS modules from the
1363 * container and not the host. This is
1366 if (get_user_creds((const char**)&arg_user, &uid, &gid, &home, NULL) < 0) {
1367 log_error("get_user_creds() failed: %m");
1371 if (mkdir_parents_label(home, 0775) < 0) {
1372 log_error("mkdir_parents_label() failed: %m");
1376 if (mkdir_safe_label(home, 0775, uid, gid) < 0) {
1377 log_error("mkdir_safe_label() failed: %m");
1381 if (initgroups((const char*)arg_user, gid) < 0) {
1382 log_error("initgroups() failed: %m");
1386 if (setresgid(gid, gid, gid) < 0) {
1387 log_error("setregid() failed: %m");
1391 if (setresuid(uid, uid, uid) < 0) {
1392 log_error("setreuid() failed: %m");
1396 /* Reset everything fully to 0, just in case */
1398 if (setgroups(0, NULL) < 0) {
1399 log_error("setgroups() failed: %m");
1403 if (setresgid(0, 0, 0) < 0) {
1404 log_error("setregid() failed: %m");
1408 if (setresuid(0, 0, 0) < 0) {
1409 log_error("setreuid() failed: %m");
1414 if ((asprintf((char**)(envp + n_env++), "HOME=%s", home ? home: "/root") < 0) ||
1415 (asprintf((char**)(envp + n_env++), "USER=%s", arg_user ? arg_user : "root") < 0) ||
1416 (asprintf((char**)(envp + n_env++), "LOGNAME=%s", arg_user ? arg_user : "root") < 0)) {
1422 if (asprintf((char**)(envp + n_env++), "container_uuid=%s", arg_uuid) < 0) {
1428 if (fdset_size(fds) > 0) {
1429 k = fdset_cloexec(fds, false);
1431 log_error("Failed to unset O_CLOEXEC for file descriptors.");
1435 if ((asprintf((char **)(envp + n_env++), "LISTEN_FDS=%u", n_fd_passed) < 0) ||
1436 (asprintf((char **)(envp + n_env++), "LISTEN_PID=%lu", (unsigned long) getpid()) < 0)) {
1448 /* Automatically search for the init system */
1450 l = 1 + argc - optind;
1451 a = newa(char*, l + 1);
1452 memcpy(a + 1, argv + optind, l * sizeof(char*));
1454 a[0] = (char*) "/usr/lib/systemd/systemd";
1455 execve(a[0], a, (char**) envp);
1457 a[0] = (char*) "/lib/systemd/systemd";
1458 execve(a[0], a, (char**) envp);
1460 a[0] = (char*) "/sbin/init";
1461 execve(a[0], a, (char**) envp);
1462 } else if (argc > optind)
1463 execvpe(argv[optind], argv + optind, (char**) envp);
1465 chdir(home ? home : "/root");
1466 execle("/bin/bash", "-bash", NULL, (char**) envp);
1469 log_error("execv() failed: %m");
1472 _exit(EXIT_FAILURE);
1478 if (process_pty(master, pid, &mask) < 0)
1481 if (saved_attr_valid)
1482 tcsetattr(STDIN_FILENO, TCSANOW, &saved_attr);
1484 r = wait_for_terminate(pid, &status);
1490 if (status.si_code == CLD_EXITED) {
1491 if (status.si_status != 0) {
1492 log_error("Container failed with error code %i.", status.si_status);
1493 r = status.si_status;
1497 log_debug("Container exited successfully.");
1499 } else if (status.si_code == CLD_KILLED &&
1500 status.si_status == SIGINT) {
1501 log_info("Container has been shut down.");
1504 } else if (status.si_code == CLD_KILLED &&
1505 status.si_status == SIGHUP) {
1506 log_info("Container is being rebooted.");
1508 } else if (status.si_code == CLD_KILLED ||
1509 status.si_code == CLD_DUMPED) {
1511 log_error("Container terminated by signal %s.", signal_to_string(status.si_status));
1515 log_error("Container failed due to unknown reason.");
1522 if (saved_attr_valid)
1523 tcsetattr(STDIN_FILENO, TCSANOW, &saved_attr);
1526 close_nointr_nofail(master);
1528 close_pipe(kmsg_socket_pair);
1531 cg_attach(SYSTEMD_CGROUP_CONTROLLER, oldcg, 0);
1534 cg_kill_recursive_and_wait(SYSTEMD_CGROUP_CONTROLLER, newcg, true);
1536 free(arg_directory);
1537 strv_free(arg_controllers);