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>
51 #include "cgroup-util.h"
53 #include "path-util.h"
54 #include "loopback-setup.h"
56 #include "dev-setup.h"
58 typedef enum LinkJournal {
65 static char *arg_directory = NULL;
66 static char *arg_user = NULL;
67 static char **arg_controllers = NULL;
68 static char *arg_uuid = NULL;
69 static bool arg_private_network = false;
70 static bool arg_read_only = false;
71 static bool arg_boot = false;
72 static LinkJournal arg_link_journal = LINK_AUTO;
73 static uint64_t arg_retain =
75 (1ULL << CAP_DAC_OVERRIDE) |
76 (1ULL << CAP_DAC_READ_SEARCH) |
77 (1ULL << CAP_FOWNER) |
78 (1ULL << CAP_FSETID) |
79 (1ULL << CAP_IPC_OWNER) |
82 (1ULL << CAP_LINUX_IMMUTABLE) |
83 (1ULL << CAP_NET_BIND_SERVICE) |
84 (1ULL << CAP_NET_BROADCAST) |
85 (1ULL << CAP_NET_RAW) |
86 (1ULL << CAP_SETGID) |
87 (1ULL << CAP_SETFCAP) |
88 (1ULL << CAP_SETPCAP) |
89 (1ULL << CAP_SETUID) |
90 (1ULL << CAP_SYS_ADMIN) |
91 (1ULL << CAP_SYS_CHROOT) |
92 (1ULL << CAP_SYS_NICE) |
93 (1ULL << CAP_SYS_PTRACE) |
94 (1ULL << CAP_SYS_TTY_CONFIG) |
95 (1ULL << CAP_SYS_RESOURCE);
97 static int help(void) {
99 printf("%s [OPTIONS...] [PATH] [ARGUMENTS...]\n\n"
100 "Spawn a minimal namespace container for debugging, testing and building.\n\n"
101 " -h --help Show this help\n"
102 " -D --directory=NAME Root directory for the container\n"
103 " -b --boot Boot up full system (i.e. invoke init)\n"
104 " -u --user=USER Run the command under specified user or uid\n"
105 " -C --controllers=LIST Put the container in specified comma-separated cgroup hierarchies\n"
106 " --uuid=UUID Set a specific machine UUID for the container\n"
107 " --private-network Disable network in container\n"
108 " --read-only Mount the root directory read-only\n"
109 " --capability=CAP In addition to the default, retain specified capability\n"
110 " --link-journal=MODE Link up guest journal, one of no, auto, guest, host\n"
111 " -j Equivalent to --link-journal=host\n",
112 program_invocation_short_name);
117 static int parse_argv(int argc, char *argv[]) {
120 ARG_PRIVATE_NETWORK = 0x100,
127 static const struct option options[] = {
128 { "help", no_argument, NULL, 'h' },
129 { "directory", required_argument, NULL, 'D' },
130 { "user", required_argument, NULL, 'u' },
131 { "controllers", required_argument, NULL, 'C' },
132 { "private-network", no_argument, NULL, ARG_PRIVATE_NETWORK },
133 { "boot", no_argument, NULL, 'b' },
134 { "uuid", required_argument, NULL, ARG_UUID },
135 { "read-only", no_argument, NULL, ARG_READ_ONLY },
136 { "capability", required_argument, NULL, ARG_CAPABILITY },
137 { "link-journal", required_argument, NULL, ARG_LINK_JOURNAL },
146 while ((c = getopt_long(argc, argv, "+hD:u:C:bj", options, NULL)) >= 0) {
156 arg_directory = canonicalize_file_name(optarg);
157 if (!arg_directory) {
158 log_error("Failed to canonicalize root directory.");
166 if (!(arg_user = strdup(optarg))) {
167 log_error("Failed to duplicate user name.");
174 strv_free(arg_controllers);
175 arg_controllers = strv_split(optarg, ",");
176 if (!arg_controllers) {
177 log_error("Failed to split controllers list.");
180 strv_uniq(arg_controllers);
184 case ARG_PRIVATE_NETWORK:
185 arg_private_network = true;
197 arg_read_only = true;
200 case ARG_CAPABILITY: {
204 FOREACH_WORD_SEPARATOR(word, length, optarg, ",", state) {
208 t = strndup(word, length);
212 if (cap_from_name(t, &cap) < 0) {
213 log_error("Failed to parse capability %s.", t);
219 arg_retain |= 1ULL << (uint64_t) cap;
226 arg_link_journal = LINK_GUEST;
229 case ARG_LINK_JOURNAL:
230 if (streq(optarg, "auto"))
231 arg_link_journal = LINK_AUTO;
232 else if (streq(optarg, "no"))
233 arg_link_journal = LINK_NO;
234 else if (streq(optarg, "guest"))
235 arg_link_journal = LINK_GUEST;
236 else if (streq(optarg, "host"))
237 arg_link_journal = LINK_HOST;
239 log_error("Failed to parse link journal mode %s", optarg);
249 log_error("Unknown option code %c", c);
257 static int mount_all(const char *dest) {
259 typedef struct MountPoint {
268 static const MountPoint mount_table[] = {
269 { "proc", "/proc", "proc", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV, true },
270 { "/proc/sys", "/proc/sys", NULL, NULL, MS_BIND, true }, /* Bind mount first */
271 { NULL, "/proc/sys", NULL, NULL, MS_BIND|MS_RDONLY|MS_REMOUNT, true }, /* Then, make it r/o */
272 { "sysfs", "/sys", "sysfs", NULL, MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV, true },
273 { "tmpfs", "/dev", "tmpfs", "mode=755", MS_NOSUID|MS_STRICTATIME, true },
274 { "/dev/pts", "/dev/pts", NULL, NULL, MS_BIND, true },
275 { "tmpfs", "/run", "tmpfs", "mode=755", MS_NOSUID|MS_NODEV|MS_STRICTATIME, true },
277 { "/sys/fs/selinux", "/sys/fs/selinux", NULL, NULL, MS_BIND, false }, /* Bind mount first */
278 { NULL, "/sys/fs/selinux", NULL, NULL, MS_BIND|MS_RDONLY|MS_REMOUNT, false }, /* Then, make it r/o */
286 for (k = 0; k < ELEMENTSOF(mount_table); k++) {
289 if (asprintf(&where, "%s/%s", dest, mount_table[k].where) < 0) {
298 t = path_is_mount_point(where, true);
300 log_error("Failed to detect whether %s is a mount point: %s", where, strerror(-t));
309 /* Skip this entry if it is not a remount. */
310 if (mount_table[k].what && t > 0)
313 mkdir_p_label(where, 0755);
315 if (mount(mount_table[k].what,
318 mount_table[k].flags,
319 mount_table[k].options) < 0 &&
320 mount_table[k].fatal) {
322 log_error("mount(%s) failed: %m", where);
334 static int setup_timezone(const char *dest) {
339 /* Fix the timezone, if possible */
340 where = strappend(dest, "/etc/localtime");
344 if (mount("/etc/localtime", where, "bind", MS_BIND, NULL) >= 0)
345 mount("/etc/localtime", where, "bind", MS_BIND|MS_REMOUNT|MS_RDONLY, NULL);
349 where = strappend(dest, "/etc/timezone");
353 if (mount("/etc/timezone", where, "bind", MS_BIND, NULL) >= 0)
354 mount("/etc/timezone", where, "bind", MS_BIND|MS_REMOUNT|MS_RDONLY, NULL);
361 static int setup_resolv_conf(const char *dest) {
366 if (arg_private_network)
369 /* Fix resolv.conf, if possible */
370 where = strappend(dest, "/etc/resolv.conf");
374 if (mount("/etc/resolv.conf", where, "bind", MS_BIND, NULL) >= 0)
375 mount("/etc/resolv.conf", where, "bind", MS_BIND|MS_REMOUNT|MS_RDONLY, NULL);
382 static int setup_boot_id(const char *dest) {
383 char *from = NULL, *to = NULL;
390 /* Generate a new randomized boot ID, so that each boot-up of
391 * the container gets a new one */
393 from = strappend(dest, "/dev/proc-sys-kernel-random-boot-id");
399 to = strappend(dest, "/proc/sys/kernel/random/boot_id");
405 r = sd_id128_randomize(&rnd);
407 log_error("Failed to generate random boot id: %s", strerror(-r));
411 snprintf(as_uuid, sizeof(as_uuid),
412 "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
413 SD_ID128_FORMAT_VAL(rnd));
414 char_array_0(as_uuid);
416 r = write_one_line_file(from, as_uuid);
418 log_error("Failed to write boot id: %s", strerror(-r));
422 if (mount(from, to, "bind", MS_BIND, NULL) < 0) {
423 log_error("Failed to bind mount boot id: %m");
426 mount(from, to, "bind", MS_BIND|MS_REMOUNT|MS_RDONLY, NULL);
437 static int copy_devnodes(const char *dest) {
439 static const char devnodes[] =
456 NULSTR_FOREACH(d, devnodes) {
458 char *from = NULL, *to = NULL;
460 asprintf(&from, "/dev/%s", d);
461 asprintf(&to, "%s/dev/%s", dest, d);
464 log_error("Failed to allocate devnode path");
477 if (stat(from, &st) < 0) {
479 if (errno != ENOENT) {
480 log_error("Failed to stat %s: %m", from);
485 } else if (!S_ISCHR(st.st_mode) && !S_ISBLK(st.st_mode)) {
487 log_error("%s is not a char or block device, cannot copy.", from);
491 } else if (mknod(to, st.st_mode, st.st_rdev) < 0) {
493 log_error("mknod(%s) failed: %m", dest);
507 static int setup_dev_console(const char *dest, const char *console) {
518 if (stat(console, &st) < 0) {
519 log_error("Failed to stat %s: %m", console);
523 } else if (!S_ISCHR(st.st_mode)) {
524 log_error("/dev/console is not a char device.");
529 r = chmod_and_chown(console, 0600, 0, 0);
531 log_error("Failed to correct access mode for TTY: %s", strerror(-r));
535 if (asprintf(&to, "%s/dev/console", dest) < 0) {
540 /* We need to bind mount the right tty to /dev/console since
541 * ptys can only exist on pts file systems. To have something
542 * to bind mount things on we create a device node first, that
543 * has the right major/minor (note that the major minor
544 * doesn't actually matter here, since we mount it over
547 if (mknod(to, (st.st_mode & ~07777) | 0600, st.st_rdev) < 0) {
548 log_error("mknod() for /dev/console failed: %m");
553 if (mount(console, to, "bind", MS_BIND, NULL) < 0) {
554 log_error("Bind mount for /dev/console failed: %m");
566 static int setup_kmsg(const char *dest, int kmsg_socket) {
567 char *from = NULL, *to = NULL;
571 struct cmsghdr cmsghdr;
572 uint8_t buf[CMSG_SPACE(sizeof(int))];
575 struct cmsghdr *cmsg;
578 assert(kmsg_socket >= 0);
582 /* We create the kmsg FIFO as /dev/kmsg, but immediately
583 * delete it after bind mounting it to /proc/kmsg. While FIFOs
584 * on the reading side behave very similar to /proc/kmsg,
585 * their writing side behaves differently from /dev/kmsg in
586 * that writing blocks when nothing is reading. In order to
587 * avoid any problems with containers deadlocking due to this
588 * we simply make /dev/kmsg unavailable to the container. */
589 if (asprintf(&from, "%s/dev/kmsg", dest) < 0) {
594 if (asprintf(&to, "%s/proc/kmsg", dest) < 0) {
599 if (mkfifo(from, 0600) < 0) {
600 log_error("mkfifo() for /dev/kmsg failed: %m");
605 r = chmod_and_chown(from, 0600, 0, 0);
607 log_error("Failed to correct access mode for /dev/kmsg: %s", strerror(-r));
611 if (mount(from, to, "bind", MS_BIND, NULL) < 0) {
612 log_error("Bind mount for /proc/kmsg failed: %m");
617 fd = open(from, O_RDWR|O_NDELAY|O_CLOEXEC);
619 log_error("Failed to open fifo: %m");
627 mh.msg_control = &control;
628 mh.msg_controllen = sizeof(control);
630 cmsg = CMSG_FIRSTHDR(&mh);
631 cmsg->cmsg_level = SOL_SOCKET;
632 cmsg->cmsg_type = SCM_RIGHTS;
633 cmsg->cmsg_len = CMSG_LEN(sizeof(int));
634 memcpy(CMSG_DATA(cmsg), &fd, sizeof(int));
636 mh.msg_controllen = cmsg->cmsg_len;
638 /* Store away the fd in the socket, so that it stays open as
639 * long as we run the child */
640 k = sendmsg(kmsg_socket, &mh, MSG_DONTWAIT|MSG_NOSIGNAL);
641 close_nointr_nofail(fd);
644 log_error("Failed to send FIFO fd: %m");
649 /* And now make the FIFO unavailable as /dev/kmsg... */
660 static int setup_hostname(void) {
664 hn = path_get_file_name(arg_directory);
670 hostname_cleanup(hn);
673 if (sethostname(hn, strlen(hn)) < 0)
682 static int setup_journal(const char *directory) {
683 sd_id128_t machine_id;
684 char *p = NULL, *b = NULL, *l, *q = NULL, *d = NULL;
687 if (arg_link_journal == LINK_NO)
690 p = strappend(directory, "/etc/machine-id");
696 r = read_one_line_file(p, &b);
697 if (r == -ENOENT && arg_link_journal == LINK_AUTO) {
701 log_error("Failed to read machine ID: %s", strerror(-r));
706 if (isempty(l) && arg_link_journal == LINK_AUTO) {
711 /* Verify validaty */
712 r = sd_id128_from_string(l, &machine_id);
714 log_error("Failed to parse machine ID: %s", strerror(-r));
719 p = strappend("/var/log/journal/", l);
720 q = strjoin(directory, "/var/log/journal/", l, NULL);
726 if (path_is_mount_point(p, false) > 0 ||
727 path_is_mount_point(q, false) > 0) {
728 if (arg_link_journal != LINK_AUTO) {
729 log_error("Journal already a mount point, refusing.");
738 r = readlink_and_make_absolute(p, &d);
740 if ((arg_link_journal == LINK_GUEST ||
741 arg_link_journal == LINK_AUTO) &&
751 log_error("Failed to remove symlink %s: %m", p);
755 } else if (r == -EINVAL) {
757 if (arg_link_journal == LINK_GUEST &&
760 if (errno == ENOTDIR)
761 log_error("%s already exists and is neither symlink nor directory.", p);
763 log_error("Failed to remove %s: %m", p);
769 } else if (r != -ENOENT) {
770 log_error("readlink(%s) failed: %m", p);
774 if (arg_link_journal == LINK_GUEST) {
776 if (symlink(q, p) < 0) {
777 log_error("Failed to symlink %s to %s: %m", q, p);
788 if (arg_link_journal == LINK_HOST) {
789 r = mkdir_p(p, 0755);
791 log_error("Failed to create %s: %m", p);
795 } else if (access(p, F_OK) < 0) {
800 if (dir_is_empty(q) == 0) {
801 log_error("%s not empty.", q);
806 r = mkdir_p(q, 0755);
808 log_error("Failed to create %s: %m", q);
812 if (mount(p, q, "bind", MS_BIND, NULL) < 0) {
813 log_error("Failed to bind mount journal from host into guest: %m");
829 static int drop_capabilities(void) {
830 return capability_bounding_set_drop(~arg_retain, false);
833 static int is_os_tree(const char *path) {
836 /* We use /bin/sh as flag file if something is an OS */
838 if (asprintf(&p, "%s/bin/sh", path) < 0)
844 return r < 0 ? 0 : 1;
847 static int process_pty(int master, sigset_t *mask) {
849 char in_buffer[LINE_MAX], out_buffer[LINE_MAX];
850 size_t in_buffer_full = 0, out_buffer_full = 0;
851 struct epoll_event stdin_ev, stdout_ev, master_ev, signal_ev;
852 bool stdin_readable = false, stdout_writable = false, master_readable = false, master_writable = false;
853 int ep = -1, signal_fd = -1, r;
855 fd_nonblock(STDIN_FILENO, 1);
856 fd_nonblock(STDOUT_FILENO, 1);
857 fd_nonblock(master, 1);
859 signal_fd = signalfd(-1, mask, SFD_NONBLOCK|SFD_CLOEXEC);
861 log_error("signalfd(): %m");
866 ep = epoll_create1(EPOLL_CLOEXEC);
868 log_error("Failed to create epoll: %m");
874 stdin_ev.events = EPOLLIN|EPOLLET;
875 stdin_ev.data.fd = STDIN_FILENO;
878 stdout_ev.events = EPOLLOUT|EPOLLET;
879 stdout_ev.data.fd = STDOUT_FILENO;
882 master_ev.events = EPOLLIN|EPOLLOUT|EPOLLET;
883 master_ev.data.fd = master;
886 signal_ev.events = EPOLLIN;
887 signal_ev.data.fd = signal_fd;
889 if (epoll_ctl(ep, EPOLL_CTL_ADD, STDIN_FILENO, &stdin_ev) < 0 ||
890 epoll_ctl(ep, EPOLL_CTL_ADD, STDOUT_FILENO, &stdout_ev) < 0 ||
891 epoll_ctl(ep, EPOLL_CTL_ADD, master, &master_ev) < 0 ||
892 epoll_ctl(ep, EPOLL_CTL_ADD, signal_fd, &signal_ev) < 0) {
893 log_error("Failed to regiser fds in epoll: %m");
899 struct epoll_event ev[16];
903 nfds = epoll_wait(ep, ev, ELEMENTSOF(ev), -1);
906 if (errno == EINTR || errno == EAGAIN)
909 log_error("epoll_wait(): %m");
916 for (i = 0; i < nfds; i++) {
917 if (ev[i].data.fd == STDIN_FILENO) {
919 if (ev[i].events & (EPOLLIN|EPOLLHUP))
920 stdin_readable = true;
922 } else if (ev[i].data.fd == STDOUT_FILENO) {
924 if (ev[i].events & (EPOLLOUT|EPOLLHUP))
925 stdout_writable = true;
927 } else if (ev[i].data.fd == master) {
929 if (ev[i].events & (EPOLLIN|EPOLLHUP))
930 master_readable = true;
932 if (ev[i].events & (EPOLLOUT|EPOLLHUP))
933 master_writable = true;
935 } else if (ev[i].data.fd == signal_fd) {
936 struct signalfd_siginfo sfsi;
939 n = read(signal_fd, &sfsi, sizeof(sfsi));
940 if (n != sizeof(sfsi)) {
943 log_error("Failed to read from signalfd: invalid block size");
948 if (errno != EINTR && errno != EAGAIN) {
949 log_error("Failed to read from signalfd: %m");
955 if (sfsi.ssi_signo == SIGWINCH) {
958 /* The window size changed, let's forward that. */
959 if (ioctl(STDIN_FILENO, TIOCGWINSZ, &ws) >= 0)
960 ioctl(master, TIOCSWINSZ, &ws);
969 while ((stdin_readable && in_buffer_full <= 0) ||
970 (master_writable && in_buffer_full > 0) ||
971 (master_readable && out_buffer_full <= 0) ||
972 (stdout_writable && out_buffer_full > 0)) {
974 if (stdin_readable && in_buffer_full < LINE_MAX) {
976 k = read(STDIN_FILENO, in_buffer + in_buffer_full, LINE_MAX - in_buffer_full);
979 if (errno == EAGAIN || errno == EPIPE || errno == ECONNRESET || errno == EIO)
980 stdin_readable = false;
982 log_error("read(): %m");
987 in_buffer_full += (size_t) k;
990 if (master_writable && in_buffer_full > 0) {
992 k = write(master, in_buffer, in_buffer_full);
995 if (errno == EAGAIN || errno == EPIPE || errno == ECONNRESET || errno == EIO)
996 master_writable = false;
998 log_error("write(): %m");
1004 assert(in_buffer_full >= (size_t) k);
1005 memmove(in_buffer, in_buffer + k, in_buffer_full - k);
1006 in_buffer_full -= k;
1010 if (master_readable && out_buffer_full < LINE_MAX) {
1012 k = read(master, out_buffer + out_buffer_full, LINE_MAX - out_buffer_full);
1015 if (errno == EAGAIN || errno == EPIPE || errno == ECONNRESET || errno == EIO)
1016 master_readable = false;
1018 log_error("read(): %m");
1023 out_buffer_full += (size_t) k;
1026 if (stdout_writable && out_buffer_full > 0) {
1028 k = write(STDOUT_FILENO, out_buffer, out_buffer_full);
1031 if (errno == EAGAIN || errno == EPIPE || errno == ECONNRESET || errno == EIO)
1032 stdout_writable = false;
1034 log_error("write(): %m");
1040 assert(out_buffer_full >= (size_t) k);
1041 memmove(out_buffer, out_buffer + k, out_buffer_full - k);
1042 out_buffer_full -= k;
1050 close_nointr_nofail(ep);
1053 close_nointr_nofail(signal_fd);
1058 int main(int argc, char *argv[]) {
1060 int r = EXIT_FAILURE, k;
1061 char *oldcg = NULL, *newcg = NULL;
1062 char **controller = NULL;
1064 const char *console = NULL;
1065 struct termios saved_attr, raw_attr;
1067 bool saved_attr_valid = false;
1069 int kmsg_socket_pair[2] = { -1, -1 };
1071 log_parse_environment();
1074 r = parse_argv(argc, argv);
1078 if (arg_directory) {
1081 p = path_make_absolute_cwd(arg_directory);
1082 free(arg_directory);
1085 arg_directory = get_current_dir_name();
1087 if (!arg_directory) {
1088 log_error("Failed to determine path");
1092 path_kill_slashes(arg_directory);
1094 if (geteuid() != 0) {
1095 log_error("Need to be root.");
1099 if (sd_booted() <= 0) {
1100 log_error("Not running on a systemd system.");
1104 if (path_equal(arg_directory, "/")) {
1105 log_error("Spawning container on root directory not supported.");
1109 if (is_os_tree(arg_directory) <= 0) {
1110 log_error("Directory %s doesn't look like an OS root directory. Refusing.", arg_directory);
1114 k = cg_get_by_pid(SYSTEMD_CGROUP_CONTROLLER, 0, &oldcg);
1116 log_error("Failed to determine current cgroup: %s", strerror(-k));
1120 if (asprintf(&newcg, "%s/nspawn-%lu", oldcg, (unsigned long) getpid()) < 0) {
1121 log_error("Failed to allocate cgroup path.");
1125 k = cg_create_and_attach(SYSTEMD_CGROUP_CONTROLLER, newcg, 0);
1127 log_error("Failed to create cgroup: %s", strerror(-k));
1131 STRV_FOREACH(controller, arg_controllers) {
1132 k = cg_create_and_attach(*controller, newcg, 0);
1134 log_warning("Failed to create cgroup in controller %s: %s", *controller, strerror(-k));
1137 master = posix_openpt(O_RDWR|O_NOCTTY|O_CLOEXEC|O_NDELAY);
1139 log_error("Failed to acquire pseudo tty: %m");
1143 console = ptsname(master);
1145 log_error("Failed to determine tty name: %m");
1149 log_info("Spawning namespace container on %s (console is %s).", arg_directory, console);
1151 if (ioctl(STDIN_FILENO, TIOCGWINSZ, &ws) >= 0)
1152 ioctl(master, TIOCSWINSZ, &ws);
1154 if (unlockpt(master) < 0) {
1155 log_error("Failed to unlock tty: %m");
1159 if (tcgetattr(STDIN_FILENO, &saved_attr) < 0) {
1160 log_error("Failed to get terminal attributes: %m");
1164 saved_attr_valid = true;
1166 raw_attr = saved_attr;
1167 cfmakeraw(&raw_attr);
1168 raw_attr.c_lflag &= ~ECHO;
1170 if (tcsetattr(STDIN_FILENO, TCSANOW, &raw_attr) < 0) {
1171 log_error("Failed to set terminal attributes: %m");
1175 if (socketpair(AF_UNIX, SOCK_DGRAM|SOCK_NONBLOCK|SOCK_CLOEXEC, 0, kmsg_socket_pair) < 0) {
1176 log_error("Failed to create kmsg socket pair");
1180 assert_se(sigemptyset(&mask) == 0);
1181 sigset_add_many(&mask, SIGCHLD, SIGWINCH, SIGTERM, SIGINT, -1);
1182 assert_se(sigprocmask(SIG_BLOCK, &mask, NULL) == 0);
1184 pid = syscall(__NR_clone, SIGCHLD|CLONE_NEWIPC|CLONE_NEWNS|CLONE_NEWPID|CLONE_NEWUTS|(arg_private_network ? CLONE_NEWNET : 0), NULL);
1186 if (errno == EINVAL)
1187 log_error("clone() failed, do you have namespace support enabled in your kernel? (You need UTS, IPC, PID and NET namespacing built in): %m");
1189 log_error("clone() failed: %m");
1197 const char *home = NULL;
1198 uid_t uid = (uid_t) -1;
1199 gid_t gid = (gid_t) -1;
1200 const char *envp[] = {
1201 "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
1202 "container=systemd-nspawn", /* LXC sets container=lxc, so follow the scheme here */
1207 NULL, /* container_uuid */
1211 envp[2] = strv_find_prefix(environ, "TERM=");
1213 close_nointr_nofail(master);
1215 close_nointr(STDIN_FILENO);
1216 close_nointr(STDOUT_FILENO);
1217 close_nointr(STDERR_FILENO);
1219 close_all_fds(&kmsg_socket_pair[1], 1);
1221 reset_all_signal_handlers();
1223 assert_se(sigemptyset(&mask) == 0);
1224 assert_se(sigprocmask(SIG_SETMASK, &mask, NULL) == 0);
1226 if (open_terminal(console, O_RDWR) != STDIN_FILENO ||
1227 dup2(STDIN_FILENO, STDOUT_FILENO) != STDOUT_FILENO ||
1228 dup2(STDIN_FILENO, STDERR_FILENO) != STDERR_FILENO)
1232 log_error("setsid() failed: %m");
1236 if (prctl(PR_SET_PDEATHSIG, SIGKILL) < 0) {
1237 log_error("PR_SET_PDEATHSIG failed: %m");
1241 /* Mark everything as slave, so that we still
1242 * receive mounts from the real root, but don't
1243 * propagate mounts to the real root. */
1244 if (mount(NULL, "/", NULL, MS_SLAVE|MS_REC, NULL) < 0) {
1245 log_error("MS_SLAVE|MS_REC failed: %m");
1249 /* Turn directory into bind mount */
1250 if (mount(arg_directory, arg_directory, "bind", MS_BIND|MS_REC, NULL) < 0) {
1251 log_error("Failed to make bind mount.");
1256 if (mount(arg_directory, arg_directory, "bind", MS_BIND|MS_REMOUNT|MS_RDONLY|MS_REC, NULL) < 0) {
1257 log_error("Failed to make read-only.");
1261 if (mount_all(arg_directory) < 0)
1264 if (copy_devnodes(arg_directory) < 0)
1267 dev_setup(arg_directory);
1269 if (setup_dev_console(arg_directory, console) < 0)
1272 if (setup_kmsg(arg_directory, kmsg_socket_pair[1]) < 0)
1275 close_nointr_nofail(kmsg_socket_pair[1]);
1277 if (setup_boot_id(arg_directory) < 0)
1280 if (setup_timezone(arg_directory) < 0)
1283 if (setup_resolv_conf(arg_directory) < 0)
1286 if (setup_journal(arg_directory) < 0)
1289 if (chdir(arg_directory) < 0) {
1290 log_error("chdir(%s) failed: %m", arg_directory);
1294 if (mount(arg_directory, "/", NULL, MS_MOVE, NULL) < 0) {
1295 log_error("mount(MS_MOVE) failed: %m");
1299 if (chroot(".") < 0) {
1300 log_error("chroot() failed: %m");
1304 if (chdir("/") < 0) {
1305 log_error("chdir() failed: %m");
1313 if (drop_capabilities() < 0) {
1314 log_error("drop_capabilities() failed: %m");
1320 if (get_user_creds((const char**)&arg_user, &uid, &gid, &home, NULL) < 0) {
1321 log_error("get_user_creds() failed: %m");
1325 if (mkdir_parents_label(home, 0775) < 0) {
1326 log_error("mkdir_parents_label() failed: %m");
1330 if (mkdir_safe_label(home, 0775, uid, gid) < 0) {
1331 log_error("mkdir_safe_label() failed: %m");
1335 if (initgroups((const char*)arg_user, gid) < 0) {
1336 log_error("initgroups() failed: %m");
1340 if (setresgid(gid, gid, gid) < 0) {
1341 log_error("setregid() failed: %m");
1345 if (setresuid(uid, uid, uid) < 0) {
1346 log_error("setreuid() failed: %m");
1351 if ((asprintf((char**)(envp + 3), "HOME=%s", home ? home: "/root") < 0) ||
1352 (asprintf((char**)(envp + 4), "USER=%s", arg_user ? arg_user : "root") < 0) ||
1353 (asprintf((char**)(envp + 5), "LOGNAME=%s", arg_user ? arg_user : "root") < 0)) {
1359 if (asprintf((char**)(envp + 6), "container_uuid=%s", arg_uuid) < 0) {
1371 /* Automatically search for the init system */
1373 l = 1 + argc - optind;
1374 a = newa(char*, l + 1);
1375 memcpy(a + 1, argv + optind, l * sizeof(char*));
1377 a[0] = (char*) "/usr/lib/systemd/systemd";
1378 execve(a[0], a, (char**) envp);
1380 a[0] = (char*) "/lib/systemd/systemd";
1381 execve(a[0], a, (char**) envp);
1383 a[0] = (char*) "/sbin/init";
1384 execve(a[0], a, (char**) envp);
1385 } else if (argc > optind)
1386 execvpe(argv[optind], argv + optind, (char**) envp);
1388 chdir(home ? home : "/root");
1389 execle("/bin/bash", "-bash", NULL, (char**) envp);
1392 log_error("execv() failed: %m");
1395 _exit(EXIT_FAILURE);
1398 if (process_pty(master, &mask) < 0)
1401 if (saved_attr_valid) {
1402 tcsetattr(STDIN_FILENO, TCSANOW, &saved_attr);
1403 saved_attr_valid = false;
1406 r = wait_for_terminate_and_warn(argc > optind ? argv[optind] : "bash", pid);
1412 if (saved_attr_valid)
1413 tcsetattr(STDIN_FILENO, TCSANOW, &saved_attr);
1416 close_nointr_nofail(master);
1418 close_pipe(kmsg_socket_pair);
1421 cg_attach(SYSTEMD_CGROUP_CONTROLLER, oldcg, 0);
1424 cg_kill_recursive_and_wait(SYSTEMD_CGROUP_CONTROLLER, newcg, true);
1426 free(arg_directory);
1427 strv_free(arg_controllers);