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"
60 typedef enum LinkJournal {
67 static char *arg_directory = NULL;
68 static char *arg_user = NULL;
69 static char **arg_controllers = NULL;
70 static char *arg_uuid = NULL;
71 static bool arg_private_network = false;
72 static bool arg_read_only = false;
73 static bool arg_boot = false;
74 static LinkJournal arg_link_journal = LINK_AUTO;
75 static uint64_t arg_retain =
77 (1ULL << CAP_DAC_OVERRIDE) |
78 (1ULL << CAP_DAC_READ_SEARCH) |
79 (1ULL << CAP_FOWNER) |
80 (1ULL << CAP_FSETID) |
81 (1ULL << CAP_IPC_OWNER) |
84 (1ULL << CAP_LINUX_IMMUTABLE) |
85 (1ULL << CAP_NET_BIND_SERVICE) |
86 (1ULL << CAP_NET_BROADCAST) |
87 (1ULL << CAP_NET_RAW) |
88 (1ULL << CAP_SETGID) |
89 (1ULL << CAP_SETFCAP) |
90 (1ULL << CAP_SETPCAP) |
91 (1ULL << CAP_SETUID) |
92 (1ULL << CAP_SYS_ADMIN) |
93 (1ULL << CAP_SYS_CHROOT) |
94 (1ULL << CAP_SYS_NICE) |
95 (1ULL << CAP_SYS_PTRACE) |
96 (1ULL << CAP_SYS_TTY_CONFIG) |
97 (1ULL << CAP_SYS_RESOURCE) |
98 (1ULL << CAP_SYS_BOOT);
100 static int help(void) {
102 printf("%s [OPTIONS...] [PATH] [ARGUMENTS...]\n\n"
103 "Spawn a minimal namespace container for debugging, testing and building.\n\n"
104 " -h --help Show this help\n"
105 " -D --directory=NAME Root directory for the container\n"
106 " -b --boot Boot up full system (i.e. invoke init)\n"
107 " -u --user=USER Run the command under specified user or uid\n"
108 " -C --controllers=LIST Put the container in specified comma-separated cgroup hierarchies\n"
109 " --uuid=UUID Set a specific machine UUID for the container\n"
110 " --private-network Disable network in container\n"
111 " --read-only Mount the root directory read-only\n"
112 " --capability=CAP In addition to the default, retain specified capability\n"
113 " --link-journal=MODE Link up guest journal, one of no, auto, guest, host\n"
114 " -j Equivalent to --link-journal=host\n",
115 program_invocation_short_name);
120 static int parse_argv(int argc, char *argv[]) {
123 ARG_PRIVATE_NETWORK = 0x100,
130 static const struct option options[] = {
131 { "help", no_argument, NULL, 'h' },
132 { "directory", required_argument, NULL, 'D' },
133 { "user", required_argument, NULL, 'u' },
134 { "controllers", required_argument, NULL, 'C' },
135 { "private-network", no_argument, NULL, ARG_PRIVATE_NETWORK },
136 { "boot", no_argument, NULL, 'b' },
137 { "uuid", required_argument, NULL, ARG_UUID },
138 { "read-only", no_argument, NULL, ARG_READ_ONLY },
139 { "capability", required_argument, NULL, ARG_CAPABILITY },
140 { "link-journal", required_argument, NULL, ARG_LINK_JOURNAL },
149 while ((c = getopt_long(argc, argv, "+hD:u:C:bj", options, NULL)) >= 0) {
159 arg_directory = canonicalize_file_name(optarg);
160 if (!arg_directory) {
161 log_error("Failed to canonicalize root directory.");
169 if (!(arg_user = strdup(optarg))) {
170 log_error("Failed to duplicate user name.");
177 strv_free(arg_controllers);
178 arg_controllers = strv_split(optarg, ",");
179 if (!arg_controllers) {
180 log_error("Failed to split controllers list.");
183 strv_uniq(arg_controllers);
187 case ARG_PRIVATE_NETWORK:
188 arg_private_network = true;
200 arg_read_only = true;
203 case ARG_CAPABILITY: {
207 FOREACH_WORD_SEPARATOR(word, length, optarg, ",", state) {
211 t = strndup(word, length);
215 if (cap_from_name(t, &cap) < 0) {
216 log_error("Failed to parse capability %s.", t);
222 arg_retain |= 1ULL << (uint64_t) cap;
229 arg_link_journal = LINK_GUEST;
232 case ARG_LINK_JOURNAL:
233 if (streq(optarg, "auto"))
234 arg_link_journal = LINK_AUTO;
235 else if (streq(optarg, "no"))
236 arg_link_journal = LINK_NO;
237 else if (streq(optarg, "guest"))
238 arg_link_journal = LINK_GUEST;
239 else if (streq(optarg, "host"))
240 arg_link_journal = LINK_HOST;
242 log_error("Failed to parse link journal mode %s", optarg);
252 log_error("Unknown option code %c", c);
260 static int mount_all(const char *dest) {
262 typedef struct MountPoint {
271 static const MountPoint mount_table[] = {
272 { "proc", "/proc", "proc", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV, true },
273 { "/proc/sys", "/proc/sys", NULL, NULL, MS_BIND, true }, /* Bind mount first */
274 { NULL, "/proc/sys", NULL, NULL, MS_BIND|MS_RDONLY|MS_REMOUNT, true }, /* Then, make it r/o */
275 { "sysfs", "/sys", "sysfs", NULL, MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV, true },
276 { "tmpfs", "/dev", "tmpfs", "mode=755", MS_NOSUID|MS_STRICTATIME, true },
277 { "/dev/pts", "/dev/pts", NULL, NULL, MS_BIND, true },
278 { "tmpfs", "/dev/shm", "tmpfs", "mode=1777", MS_NOSUID|MS_NODEV|MS_STRICTATIME, true },
279 { "tmpfs", "/run", "tmpfs", "mode=755", MS_NOSUID|MS_NODEV|MS_STRICTATIME, true },
281 { "/sys/fs/selinux", "/sys/fs/selinux", NULL, NULL, MS_BIND, false }, /* Bind mount first */
282 { NULL, "/sys/fs/selinux", NULL, NULL, MS_BIND|MS_RDONLY|MS_REMOUNT, false }, /* Then, make it r/o */
289 for (k = 0; k < ELEMENTSOF(mount_table); k++) {
290 char _cleanup_free_ *where = NULL;
293 if (asprintf(&where, "%s/%s", dest, mount_table[k].where) < 0) {
302 t = path_is_mount_point(where, true);
304 log_error("Failed to detect whether %s is a mount point: %s", where, strerror(-t));
312 /* Skip this entry if it is not a remount. */
313 if (mount_table[k].what && t > 0)
316 mkdir_p_label(where, 0755);
318 if (mount(mount_table[k].what,
321 mount_table[k].flags,
322 mount_table[k].options) < 0 &&
323 mount_table[k].fatal) {
325 log_error("mount(%s) failed: %m", where);
335 static int setup_timezone(const char *dest) {
336 _cleanup_free_ char *where = NULL, *p = NULL, *q = NULL, *check = NULL, *what = NULL;
342 /* Fix the timezone, if possible */
343 r = readlink_malloc("/etc/localtime", &p);
345 log_warning("/etc/localtime is not a symlink, not updating container timezone.");
349 z = path_startswith(p, "../usr/share/zoneinfo/");
351 z = path_startswith(p, "/usr/share/zoneinfo/");
353 log_warning("/etc/localtime does not point into /usr/share/zoneinfo/, not updating container timezone.");
357 where = strappend(dest, "/etc/localtime");
361 r = readlink_malloc(where, &q);
363 y = path_startswith(q, "../usr/share/zoneinfo/");
365 y = path_startswith(q, "/usr/share/zoneinfo/");
368 /* Already pointing to the right place? Then do nothing .. */
369 if (y && streq(y, z))
373 check = strjoin(dest, "/usr/share/zoneinfo/", z, NULL);
377 if (access(check, F_OK) < 0) {
378 log_warning("Timezone %s does not exist in container, not updating container timezone.", z);
382 what = strappend("../usr/share/zoneinfo/", z);
387 if (symlink(what, where) < 0) {
388 log_error("Failed to correct timezone of container: %m");
395 static int setup_resolv_conf(const char *dest) {
400 if (arg_private_network)
403 /* Fix resolv.conf, if possible */
404 where = strappend(dest, "/etc/resolv.conf");
408 /* We don't really care for the results of this really. If it
409 * fails, it fails, but meh... */
410 if (mount("/etc/resolv.conf", where, "bind", MS_BIND, NULL) >= 0)
411 mount("/etc/resolv.conf", where, "bind", MS_BIND|MS_REMOUNT|MS_RDONLY, NULL);
418 static int setup_boot_id(const char *dest) {
419 char _cleanup_free_ *from = NULL, *to = NULL;
426 /* Generate a new randomized boot ID, so that each boot-up of
427 * the container gets a new one */
429 from = strappend(dest, "/dev/proc-sys-kernel-random-boot-id");
430 to = strappend(dest, "/proc/sys/kernel/random/boot_id");
434 r = sd_id128_randomize(&rnd);
436 log_error("Failed to generate random boot id: %s", strerror(-r));
440 snprintf(as_uuid, sizeof(as_uuid),
441 "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
442 SD_ID128_FORMAT_VAL(rnd));
443 char_array_0(as_uuid);
445 r = write_one_line_file(from, as_uuid);
447 log_error("Failed to write boot id: %s", strerror(-r));
451 if (mount(from, to, "bind", MS_BIND, NULL) < 0) {
452 log_error("Failed to bind mount boot id: %m");
455 mount(from, to, "bind", MS_BIND|MS_REMOUNT|MS_RDONLY, NULL);
461 static int copy_devnodes(const char *dest) {
463 static const char devnodes[] =
474 mode_t _cleanup_umask_ u;
480 NULSTR_FOREACH(d, devnodes) {
482 char _cleanup_free_ *from = NULL, *to = NULL;
484 asprintf(&from, "/dev/%s", d);
485 asprintf(&to, "%s/dev/%s", dest, d);
496 if (stat(from, &st) < 0) {
498 if (errno != ENOENT) {
499 log_error("Failed to stat %s: %m", from);
504 } else if (!S_ISCHR(st.st_mode) && !S_ISBLK(st.st_mode)) {
506 log_error("%s is not a char or block device, cannot copy", from);
510 } else if (mknod(to, st.st_mode, st.st_rdev) < 0) {
512 log_error("mknod(%s) failed: %m", dest);
521 static int setup_dev_console(const char *dest, const char *console) {
523 char _cleanup_free_ *to = NULL;
525 mode_t _cleanup_umask_ u;
532 if (stat(console, &st) < 0) {
533 log_error("Failed to stat %s: %m", console);
536 } else if (!S_ISCHR(st.st_mode)) {
537 log_error("/dev/console is not a char device");
541 r = chmod_and_chown(console, 0600, 0, 0);
543 log_error("Failed to correct access mode for TTY: %s", strerror(-r));
547 if (asprintf(&to, "%s/dev/console", dest) < 0)
550 /* We need to bind mount the right tty to /dev/console since
551 * ptys can only exist on pts file systems. To have something
552 * to bind mount things on we create a device node first, that
553 * has the right major/minor (note that the major minor
554 * doesn't actually matter here, since we mount it over
557 if (mknod(to, (st.st_mode & ~07777) | 0600, st.st_rdev) < 0) {
558 log_error("mknod() for /dev/console failed: %m");
562 if (mount(console, to, "bind", MS_BIND, NULL) < 0) {
563 log_error("Bind mount for /dev/console failed: %m");
570 static int setup_kmsg(const char *dest, int kmsg_socket) {
571 char _cleanup_free_ *from = NULL, *to = NULL;
573 mode_t _cleanup_umask_ u;
575 struct cmsghdr cmsghdr;
576 uint8_t buf[CMSG_SPACE(sizeof(int))];
579 struct cmsghdr *cmsg;
582 assert(kmsg_socket >= 0);
586 /* We create the kmsg FIFO as /dev/kmsg, but immediately
587 * delete it after bind mounting it to /proc/kmsg. While FIFOs
588 * on the reading side behave very similar to /proc/kmsg,
589 * their writing side behaves differently from /dev/kmsg in
590 * that writing blocks when nothing is reading. In order to
591 * avoid any problems with containers deadlocking due to this
592 * we simply make /dev/kmsg unavailable to the container. */
593 if (asprintf(&from, "%s/dev/kmsg", dest) < 0 ||
594 asprintf(&to, "%s/proc/kmsg", dest) < 0)
597 if (mkfifo(from, 0600) < 0) {
598 log_error("mkfifo() for /dev/kmsg failed: %m");
602 r = chmod_and_chown(from, 0600, 0, 0);
604 log_error("Failed to correct access mode for /dev/kmsg: %s", strerror(-r));
608 if (mount(from, to, "bind", MS_BIND, NULL) < 0) {
609 log_error("Bind mount for /proc/kmsg failed: %m");
613 fd = open(from, O_RDWR|O_NDELAY|O_CLOEXEC);
615 log_error("Failed to open fifo: %m");
622 mh.msg_control = &control;
623 mh.msg_controllen = sizeof(control);
625 cmsg = CMSG_FIRSTHDR(&mh);
626 cmsg->cmsg_level = SOL_SOCKET;
627 cmsg->cmsg_type = SCM_RIGHTS;
628 cmsg->cmsg_len = CMSG_LEN(sizeof(int));
629 memcpy(CMSG_DATA(cmsg), &fd, sizeof(int));
631 mh.msg_controllen = cmsg->cmsg_len;
633 /* Store away the fd in the socket, so that it stays open as
634 * long as we run the child */
635 k = sendmsg(kmsg_socket, &mh, MSG_DONTWAIT|MSG_NOSIGNAL);
636 close_nointr_nofail(fd);
639 log_error("Failed to send FIFO fd: %m");
643 /* And now make the FIFO unavailable as /dev/kmsg... */
648 static int setup_hostname(void) {
652 hn = path_get_file_name(arg_directory);
658 hostname_cleanup(hn);
661 if (sethostname(hn, strlen(hn)) < 0)
670 static int setup_journal(const char *directory) {
671 sd_id128_t machine_id;
672 char _cleanup_free_ *p = NULL, *b = NULL, *q = NULL, *d = NULL;
676 if (arg_link_journal == LINK_NO)
679 p = strappend(directory, "/etc/machine-id");
683 r = read_one_line_file(p, &b);
684 if (r == -ENOENT && arg_link_journal == LINK_AUTO)
687 log_error("Failed to read machine ID from %s: %s", p, strerror(-r));
692 if (isempty(id) && arg_link_journal == LINK_AUTO)
695 /* Verify validity */
696 r = sd_id128_from_string(id, &machine_id);
698 log_error("Failed to parse machine ID from %s: %s", p, strerror(-r));
703 p = strappend("/var/log/journal/", id);
704 q = strjoin(directory, "/var/log/journal/", id, NULL);
708 if (path_is_mount_point(p, false) > 0) {
709 if (arg_link_journal != LINK_AUTO) {
710 log_error("%s: already a mount point, refusing to use for journal", p);
717 if (path_is_mount_point(q, false) > 0) {
718 if (arg_link_journal != LINK_AUTO) {
719 log_error("%s: already a mount point, refusing to use for journal", q);
726 r = readlink_and_make_absolute(p, &d);
728 if ((arg_link_journal == LINK_GUEST ||
729 arg_link_journal == LINK_AUTO) &&
732 r = mkdir_p(q, 0755);
734 log_warning("failed to create directory %s: %m", q);
739 log_error("Failed to remove symlink %s: %m", p);
742 } else if (r == -EINVAL) {
744 if (arg_link_journal == LINK_GUEST &&
747 if (errno == ENOTDIR) {
748 log_error("%s already exists and is neither a symlink nor a directory", p);
751 log_error("Failed to remove %s: %m", p);
755 } else if (r != -ENOENT) {
756 log_error("readlink(%s) failed: %m", p);
760 if (arg_link_journal == LINK_GUEST) {
762 if (symlink(q, p) < 0) {
763 log_error("Failed to symlink %s to %s: %m", q, p);
767 r = mkdir_p(q, 0755);
769 log_warning("failed to create directory %s: %m", q);
773 if (arg_link_journal == LINK_HOST) {
774 r = mkdir_p(p, 0755);
776 log_error("Failed to create %s: %m", p);
780 } else if (access(p, F_OK) < 0)
783 if (dir_is_empty(q) == 0) {
784 log_error("%s not empty.", q);
788 r = mkdir_p(q, 0755);
790 log_error("Failed to create %s: %m", q);
794 if (mount(p, q, "bind", MS_BIND, NULL) < 0) {
795 log_error("Failed to bind mount journal from host into guest: %m");
802 static int drop_capabilities(void) {
803 return capability_bounding_set_drop(~arg_retain, false);
806 static int is_os_tree(const char *path) {
809 /* We use /bin/sh as flag file if something is an OS */
811 if (asprintf(&p, "%s/bin/sh", path) < 0)
817 return r < 0 ? 0 : 1;
820 static int process_pty(int master, sigset_t *mask) {
822 char in_buffer[LINE_MAX], out_buffer[LINE_MAX];
823 size_t in_buffer_full = 0, out_buffer_full = 0;
824 struct epoll_event stdin_ev, stdout_ev, master_ev, signal_ev;
825 bool stdin_readable = false, stdout_writable = false, master_readable = false, master_writable = false;
826 int ep = -1, signal_fd = -1, r;
828 fd_nonblock(STDIN_FILENO, 1);
829 fd_nonblock(STDOUT_FILENO, 1);
830 fd_nonblock(master, 1);
832 signal_fd = signalfd(-1, mask, SFD_NONBLOCK|SFD_CLOEXEC);
834 log_error("signalfd(): %m");
839 ep = epoll_create1(EPOLL_CLOEXEC);
841 log_error("Failed to create epoll: %m");
846 /* We read from STDIN only if this is actually a TTY,
847 * otherwise we assume non-interactivity. */
848 if (isatty(STDIN_FILENO)) {
850 stdin_ev.events = EPOLLIN|EPOLLET;
851 stdin_ev.data.fd = STDIN_FILENO;
853 if (epoll_ctl(ep, EPOLL_CTL_ADD, STDIN_FILENO, &stdin_ev) < 0) {
854 log_error("Failed to register STDIN in epoll: %m");
861 stdout_ev.events = EPOLLOUT|EPOLLET;
862 stdout_ev.data.fd = STDOUT_FILENO;
865 master_ev.events = EPOLLIN|EPOLLOUT|EPOLLET;
866 master_ev.data.fd = master;
869 signal_ev.events = EPOLLIN;
870 signal_ev.data.fd = signal_fd;
872 if (epoll_ctl(ep, EPOLL_CTL_ADD, STDOUT_FILENO, &stdout_ev) < 0 ||
873 epoll_ctl(ep, EPOLL_CTL_ADD, master, &master_ev) < 0 ||
874 epoll_ctl(ep, EPOLL_CTL_ADD, signal_fd, &signal_ev) < 0) {
875 log_error("Failed to register fds in epoll: %m");
881 struct epoll_event ev[16];
885 nfds = epoll_wait(ep, ev, ELEMENTSOF(ev), -1);
888 if (errno == EINTR || errno == EAGAIN)
891 log_error("epoll_wait(): %m");
898 for (i = 0; i < nfds; i++) {
899 if (ev[i].data.fd == STDIN_FILENO) {
901 if (ev[i].events & (EPOLLIN|EPOLLHUP))
902 stdin_readable = true;
904 } else if (ev[i].data.fd == STDOUT_FILENO) {
906 if (ev[i].events & (EPOLLOUT|EPOLLHUP))
907 stdout_writable = true;
909 } else if (ev[i].data.fd == master) {
911 if (ev[i].events & (EPOLLIN|EPOLLHUP))
912 master_readable = true;
914 if (ev[i].events & (EPOLLOUT|EPOLLHUP))
915 master_writable = true;
917 } else if (ev[i].data.fd == signal_fd) {
918 struct signalfd_siginfo sfsi;
921 n = read(signal_fd, &sfsi, sizeof(sfsi));
922 if (n != sizeof(sfsi)) {
925 log_error("Failed to read from signalfd: invalid block size");
930 if (errno != EINTR && errno != EAGAIN) {
931 log_error("Failed to read from signalfd: %m");
937 if (sfsi.ssi_signo == SIGWINCH) {
940 /* The window size changed, let's forward that. */
941 if (ioctl(STDIN_FILENO, TIOCGWINSZ, &ws) >= 0)
942 ioctl(master, TIOCSWINSZ, &ws);
951 while ((stdin_readable && in_buffer_full <= 0) ||
952 (master_writable && in_buffer_full > 0) ||
953 (master_readable && out_buffer_full <= 0) ||
954 (stdout_writable && out_buffer_full > 0)) {
956 if (stdin_readable && in_buffer_full < LINE_MAX) {
958 k = read(STDIN_FILENO, in_buffer + in_buffer_full, LINE_MAX - in_buffer_full);
961 if (errno == EAGAIN || errno == EPIPE || errno == ECONNRESET || errno == EIO)
962 stdin_readable = false;
964 log_error("read(): %m");
969 in_buffer_full += (size_t) k;
972 if (master_writable && in_buffer_full > 0) {
974 k = write(master, in_buffer, in_buffer_full);
977 if (errno == EAGAIN || errno == EPIPE || errno == ECONNRESET || errno == EIO)
978 master_writable = false;
980 log_error("write(): %m");
986 assert(in_buffer_full >= (size_t) k);
987 memmove(in_buffer, in_buffer + k, in_buffer_full - k);
992 if (master_readable && out_buffer_full < LINE_MAX) {
994 k = read(master, out_buffer + out_buffer_full, LINE_MAX - out_buffer_full);
997 if (errno == EAGAIN || errno == EPIPE || errno == ECONNRESET || errno == EIO)
998 master_readable = false;
1000 log_error("read(): %m");
1005 out_buffer_full += (size_t) k;
1008 if (stdout_writable && out_buffer_full > 0) {
1010 k = write(STDOUT_FILENO, out_buffer, out_buffer_full);
1013 if (errno == EAGAIN || errno == EPIPE || errno == ECONNRESET || errno == EIO)
1014 stdout_writable = false;
1016 log_error("write(): %m");
1022 assert(out_buffer_full >= (size_t) k);
1023 memmove(out_buffer, out_buffer + k, out_buffer_full - k);
1024 out_buffer_full -= k;
1032 close_nointr_nofail(ep);
1035 close_nointr_nofail(signal_fd);
1040 int main(int argc, char *argv[]) {
1042 int r = EXIT_FAILURE, k;
1043 char *oldcg = NULL, *newcg = NULL;
1044 char **controller = NULL;
1045 int master = -1, n_fd_passed;
1046 const char *console = NULL;
1047 struct termios saved_attr, raw_attr;
1049 bool saved_attr_valid = false;
1051 int kmsg_socket_pair[2] = { -1, -1 };
1054 log_parse_environment();
1057 r = parse_argv(argc, argv);
1061 if (arg_directory) {
1064 p = path_make_absolute_cwd(arg_directory);
1065 free(arg_directory);
1068 arg_directory = get_current_dir_name();
1070 if (!arg_directory) {
1071 log_error("Failed to determine path");
1075 path_kill_slashes(arg_directory);
1077 if (geteuid() != 0) {
1078 log_error("Need to be root.");
1082 if (sd_booted() <= 0) {
1083 log_error("Not running on a systemd system.");
1087 if (path_equal(arg_directory, "/")) {
1088 log_error("Spawning container on root directory not supported.");
1092 if (is_os_tree(arg_directory) <= 0) {
1093 log_error("Directory %s doesn't look like an OS root directory. Refusing.", arg_directory);
1098 n_fd_passed = sd_listen_fds(false);
1099 if (n_fd_passed > 0) {
1100 k = fdset_new_listen_fds(&fds, false);
1102 log_error("Failed to collect file descriptors: %s", strerror(-k));
1106 fdset_close_others(fds);
1109 k = cg_get_by_pid(SYSTEMD_CGROUP_CONTROLLER, 0, &oldcg);
1111 log_error("Failed to determine current cgroup: %s", strerror(-k));
1115 if (asprintf(&newcg, "%s/nspawn-%lu", oldcg, (unsigned long) getpid()) < 0) {
1116 log_error("Failed to allocate cgroup path.");
1120 k = cg_create_and_attach(SYSTEMD_CGROUP_CONTROLLER, newcg, 0);
1122 log_error("Failed to create cgroup: %s", strerror(-k));
1126 STRV_FOREACH(controller, arg_controllers) {
1127 k = cg_create_and_attach(*controller, newcg, 0);
1129 log_warning("Failed to create cgroup in controller %s: %s", *controller, strerror(-k));
1132 master = posix_openpt(O_RDWR|O_NOCTTY|O_CLOEXEC|O_NDELAY);
1134 log_error("Failed to acquire pseudo tty: %m");
1138 console = ptsname(master);
1140 log_error("Failed to determine tty name: %m");
1144 log_info("Spawning namespace container on %s (console is %s).", arg_directory, console);
1146 if (ioctl(STDIN_FILENO, TIOCGWINSZ, &ws) >= 0)
1147 ioctl(master, TIOCSWINSZ, &ws);
1149 if (unlockpt(master) < 0) {
1150 log_error("Failed to unlock tty: %m");
1154 if (tcgetattr(STDIN_FILENO, &saved_attr) >= 0) {
1155 saved_attr_valid = true;
1157 raw_attr = saved_attr;
1158 cfmakeraw(&raw_attr);
1159 raw_attr.c_lflag &= ~ECHO;
1162 if (socketpair(AF_UNIX, SOCK_DGRAM|SOCK_NONBLOCK|SOCK_CLOEXEC, 0, kmsg_socket_pair) < 0) {
1163 log_error("Failed to create kmsg socket pair");
1167 assert_se(sigemptyset(&mask) == 0);
1168 sigset_add_many(&mask, SIGCHLD, SIGWINCH, SIGTERM, SIGINT, -1);
1169 assert_se(sigprocmask(SIG_BLOCK, &mask, NULL) == 0);
1174 if (saved_attr_valid) {
1175 if (tcsetattr(STDIN_FILENO, TCSANOW, &raw_attr) < 0) {
1176 log_error("Failed to set terminal attributes: %m");
1181 pid = syscall(__NR_clone, SIGCHLD|CLONE_NEWIPC|CLONE_NEWNS|CLONE_NEWPID|CLONE_NEWUTS|(arg_private_network ? CLONE_NEWNET : 0), NULL);
1183 if (errno == EINVAL)
1184 log_error("clone() failed, do you have namespace support enabled in your kernel? (You need UTS, IPC, PID and NET namespacing built in): %m");
1186 log_error("clone() failed: %m");
1194 const char *home = NULL;
1195 uid_t uid = (uid_t) -1;
1196 gid_t gid = (gid_t) -1;
1198 const char *envp[] = {
1199 "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
1200 "container=systemd-nspawn", /* LXC sets container=lxc, so follow the scheme here */
1205 NULL, /* container_uuid */
1206 NULL, /* LISTEN_FDS */
1207 NULL, /* LISTEN_PID */
1211 envp[2] = strv_find_prefix(environ, "TERM=");
1214 close_nointr_nofail(master);
1217 close_nointr(STDIN_FILENO);
1218 close_nointr(STDOUT_FILENO);
1219 close_nointr(STDERR_FILENO);
1221 close_nointr_nofail(kmsg_socket_pair[0]);
1222 kmsg_socket_pair[0] = -1;
1224 reset_all_signal_handlers();
1226 assert_se(sigemptyset(&mask) == 0);
1227 assert_se(sigprocmask(SIG_SETMASK, &mask, NULL) == 0);
1229 k = open_terminal(console, O_RDWR);
1230 if (k != STDIN_FILENO) {
1232 close_nointr_nofail(k);
1236 log_error("Failed to open console: %s", strerror(-k));
1240 if (dup2(STDIN_FILENO, STDOUT_FILENO) != STDOUT_FILENO ||
1241 dup2(STDIN_FILENO, STDERR_FILENO) != STDERR_FILENO) {
1242 log_error("Failed to duplicate console: %m");
1247 log_error("setsid() failed: %m");
1251 if (prctl(PR_SET_PDEATHSIG, SIGKILL) < 0) {
1252 log_error("PR_SET_PDEATHSIG failed: %m");
1256 /* Mark everything as slave, so that we still
1257 * receive mounts from the real root, but don't
1258 * propagate mounts to the real root. */
1259 if (mount(NULL, "/", NULL, MS_SLAVE|MS_REC, NULL) < 0) {
1260 log_error("MS_SLAVE|MS_REC failed: %m");
1264 /* Turn directory into bind mount */
1265 if (mount(arg_directory, arg_directory, "bind", MS_BIND|MS_REC, NULL) < 0) {
1266 log_error("Failed to make bind mount.");
1271 if (mount(arg_directory, arg_directory, "bind", MS_BIND|MS_REMOUNT|MS_RDONLY|MS_REC, NULL) < 0) {
1272 log_error("Failed to make read-only.");
1276 if (mount_all(arg_directory) < 0)
1279 if (copy_devnodes(arg_directory) < 0)
1282 dev_setup(arg_directory);
1284 if (setup_dev_console(arg_directory, console) < 0)
1287 if (setup_kmsg(arg_directory, kmsg_socket_pair[1]) < 0)
1290 close_nointr_nofail(kmsg_socket_pair[1]);
1291 kmsg_socket_pair[1] = -1;
1293 if (setup_boot_id(arg_directory) < 0)
1296 if (setup_timezone(arg_directory) < 0)
1299 if (setup_resolv_conf(arg_directory) < 0)
1302 if (setup_journal(arg_directory) < 0)
1305 if (chdir(arg_directory) < 0) {
1306 log_error("chdir(%s) failed: %m", arg_directory);
1310 if (mount(arg_directory, "/", NULL, MS_MOVE, NULL) < 0) {
1311 log_error("mount(MS_MOVE) failed: %m");
1315 if (chroot(".") < 0) {
1316 log_error("chroot() failed: %m");
1320 if (chdir("/") < 0) {
1321 log_error("chdir() failed: %m");
1329 if (drop_capabilities() < 0) {
1330 log_error("drop_capabilities() failed: %m");
1336 /* Note that this resolves user names
1337 * inside the container, and hence
1338 * accesses the NSS modules from the
1339 * container and not the host. This is
1342 if (get_user_creds((const char**)&arg_user, &uid, &gid, &home, NULL) < 0) {
1343 log_error("get_user_creds() failed: %m");
1347 if (mkdir_parents_label(home, 0775) < 0) {
1348 log_error("mkdir_parents_label() failed: %m");
1352 if (mkdir_safe_label(home, 0775, uid, gid) < 0) {
1353 log_error("mkdir_safe_label() failed: %m");
1357 if (initgroups((const char*)arg_user, gid) < 0) {
1358 log_error("initgroups() failed: %m");
1362 if (setresgid(gid, gid, gid) < 0) {
1363 log_error("setregid() failed: %m");
1367 if (setresuid(uid, uid, uid) < 0) {
1368 log_error("setreuid() failed: %m");
1372 /* Reset everything fully to 0, just in case */
1374 if (setgroups(0, NULL) < 0) {
1375 log_error("setgroups() failed: %m");
1379 if (setresgid(0, 0, 0) < 0) {
1380 log_error("setregid() failed: %m");
1384 if (setresuid(0, 0, 0) < 0) {
1385 log_error("setreuid() failed: %m");
1390 if ((asprintf((char**)(envp + n_env++), "HOME=%s", home ? home: "/root") < 0) ||
1391 (asprintf((char**)(envp + n_env++), "USER=%s", arg_user ? arg_user : "root") < 0) ||
1392 (asprintf((char**)(envp + n_env++), "LOGNAME=%s", arg_user ? arg_user : "root") < 0)) {
1398 if (asprintf((char**)(envp + n_env++), "container_uuid=%s", arg_uuid) < 0) {
1404 if (fdset_size(fds) > 0) {
1405 k = fdset_cloexec(fds, false);
1407 log_error("Failed to unset O_CLOEXEC for file descriptors.");
1411 if ((asprintf((char **)(envp + n_env++), "LISTEN_FDS=%u", n_fd_passed) < 0) ||
1412 (asprintf((char **)(envp + n_env++), "LISTEN_PID=%lu", (unsigned long) getpid()) < 0)) {
1424 /* Automatically search for the init system */
1426 l = 1 + argc - optind;
1427 a = newa(char*, l + 1);
1428 memcpy(a + 1, argv + optind, l * sizeof(char*));
1430 a[0] = (char*) "/usr/lib/systemd/systemd";
1431 execve(a[0], a, (char**) envp);
1433 a[0] = (char*) "/lib/systemd/systemd";
1434 execve(a[0], a, (char**) envp);
1436 a[0] = (char*) "/sbin/init";
1437 execve(a[0], a, (char**) envp);
1438 } else if (argc > optind)
1439 execvpe(argv[optind], argv + optind, (char**) envp);
1441 chdir(home ? home : "/root");
1442 execle("/bin/bash", "-bash", NULL, (char**) envp);
1445 log_error("execv() failed: %m");
1448 _exit(EXIT_FAILURE);
1454 if (process_pty(master, &mask) < 0)
1457 if (saved_attr_valid)
1458 tcsetattr(STDIN_FILENO, TCSANOW, &saved_attr);
1460 r = wait_for_terminate(pid, &status);
1466 if (status.si_code == CLD_EXITED) {
1467 if (status.si_status != 0) {
1468 log_error("Container failed with error code %i.", status.si_status);
1469 r = status.si_status;
1473 log_debug("Container exited successfully.");
1475 } else if (status.si_code == CLD_KILLED &&
1476 status.si_status == SIGINT) {
1477 log_info("Container has been shut down.");
1480 } else if (status.si_code == CLD_KILLED &&
1481 status.si_status == SIGHUP) {
1482 log_info("Container is being rebooted.");
1484 } else if (status.si_code == CLD_KILLED ||
1485 status.si_code == CLD_DUMPED) {
1487 log_error("Container terminated by signal %s.", signal_to_string(status.si_status));
1491 log_error("Container failed due to unknown reason.");
1498 if (saved_attr_valid)
1499 tcsetattr(STDIN_FILENO, TCSANOW, &saved_attr);
1502 close_nointr_nofail(master);
1504 close_pipe(kmsg_socket_pair);
1507 cg_attach(SYSTEMD_CGROUP_CONTROLLER, oldcg, 0);
1510 cg_kill_recursive_and_wait(SYSTEMD_CGROUP_CONTROLLER, newcg, true);
1512 free(arg_directory);
1513 strv_free(arg_controllers);