| /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ |
| |
| /*** |
| 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 General Public License as published by |
| the Free Software Foundation; either version 2 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 |
| General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with systemd; If not, see <http://www.gnu.org/licenses/>. |
| ***/ |
| |
| #include <signal.h> |
| #include <sched.h> |
| #include <unistd.h> |
| #include <sys/types.h> |
| #include <sys/syscall.h> |
| #include <sys/mount.h> |
| #include <sys/wait.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <stdio.h> |
| #include <errno.h> |
| #include <sys/prctl.h> |
| #include <sys/capability.h> |
| #include <getopt.h> |
| #include <sys/epoll.h> |
| #include <termios.h> |
| #include <sys/signalfd.h> |
| #include <grp.h> |
| #include <linux/fs.h> |
| |
| #include "log.h" |
| #include "util.h" |
| #include "missing.h" |
| #include "cgroup-util.h" |
| #include "sd-daemon.h" |
| #include "strv.h" |
| #include "loopback-setup.h" |
| |
| static char *arg_directory = NULL; |
| static char *arg_user = NULL; |
| static bool arg_private_network = false; |
| |
| static int 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" |
| " -D --directory=NAME Root directory for the container\n" |
| " -u --user=USER Run the command under specified user or uid\n" |
| " --private-network Disable network in container\n", |
| program_invocation_short_name); |
| |
| return 0; |
| } |
| |
| static int parse_argv(int argc, char *argv[]) { |
| |
| enum { |
| ARG_PRIVATE_NETWORK = 0x100 |
| }; |
| |
| static const struct option options[] = { |
| { "help", no_argument, NULL, 'h' }, |
| { "directory", required_argument, NULL, 'D' }, |
| { "user", required_argument, NULL, 'u' }, |
| { "private-network", no_argument, NULL, ARG_PRIVATE_NETWORK }, |
| { NULL, 0, NULL, 0 } |
| }; |
| |
| int c; |
| |
| assert(argc >= 0); |
| assert(argv); |
| |
| while ((c = getopt_long(argc, argv, "+hD:u:", options, NULL)) >= 0) { |
| |
| switch (c) { |
| |
| case 'h': |
| help(); |
| return 0; |
| |
| case 'D': |
| free(arg_directory); |
| if (!(arg_directory = strdup(optarg))) { |
| log_error("Failed to duplicate root directory."); |
| return -ENOMEM; |
| } |
| |
| break; |
| |
| case 'u': |
| free(arg_user); |
| if (!(arg_user = strdup(optarg))) { |
| log_error("Failed to duplicate user name."); |
| return -ENOMEM; |
| } |
| |
| break; |
| |
| case ARG_PRIVATE_NETWORK: |
| arg_private_network = true; |
| break; |
| |
| case '?': |
| return -EINVAL; |
| |
| default: |
| log_error("Unknown option code %c", c); |
| return -EINVAL; |
| } |
| } |
| |
| return 1; |
| } |
| |
| static int mount_all(const char *dest) { |
| |
| typedef struct MountPoint { |
| const char *what; |
| const char *where; |
| const char *type; |
| const char *options; |
| unsigned long flags; |
| bool fatal; |
| } MountPoint; |
| |
| static const MountPoint mount_table[] = { |
| { "proc", "/proc", "proc", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV, true }, |
| { "/proc/sys", "/proc/sys", "bind", NULL, MS_BIND, true }, /* Bind mount first */ |
| { "/proc/sys", "/proc/sys", "bind", NULL, MS_BIND|MS_RDONLY|MS_REMOUNT, true }, /* Then, make it r/o */ |
| { "/sys", "/sys", "bind", NULL, MS_BIND, true }, /* Bind mount first */ |
| { "/sys", "/sys", "bind", NULL, MS_BIND|MS_RDONLY|MS_REMOUNT, true }, /* Then, make it r/o */ |
| { "tmpfs", "/dev", "tmpfs", "mode=755", MS_NOSUID, true }, |
| { "/dev/pts", "/dev/pts", "bind", NULL, MS_BIND, true }, |
| { "tmpfs", "/run", "tmpfs", "mode=755", MS_NOSUID|MS_NODEV, true }, |
| #ifdef HAVE_SELINUX |
| { "/sys/fs/selinux", "/sys/fs/selinux", "bind", NULL, MS_BIND, false }, /* Bind mount first */ |
| { "/sys/fs/selinux", "/sys/fs/selinux", "bind", NULL, MS_BIND|MS_RDONLY|MS_REMOUNT, false }, /* Then, make it r/o */ |
| #endif |
| }; |
| |
| unsigned k; |
| int r = 0; |
| char *where; |
| |
| for (k = 0; k < ELEMENTSOF(mount_table); k++) { |
| int t; |
| |
| if (asprintf(&where, "%s/%s", dest, mount_table[k].where) < 0) { |
| log_error("Out of memory"); |
| |
| if (r == 0) |
| r = -ENOMEM; |
| |
| break; |
| } |
| |
| if ((t = path_is_mount_point(where, false)) < 0) { |
| log_error("Failed to detect whether %s is a mount point: %s", where, strerror(-t)); |
| free(where); |
| |
| if (r == 0) |
| r = t; |
| |
| continue; |
| } |
| |
| mkdir_p(where, 0755); |
| |
| if (mount(mount_table[k].what, |
| where, |
| mount_table[k].type, |
| mount_table[k].flags, |
| mount_table[k].options) < 0 && |
| mount_table[k].fatal) { |
| |
| log_error("mount(%s) failed: %m", where); |
| |
| if (r == 0) |
| r = -errno; |
| } |
| |
| free(where); |
| } |
| |
| /* Fix the timezone, if possible */ |
| if (asprintf(&where, "%s/%s", dest, "/etc/localtime") >= 0) { |
| mount("/etc/localtime", where, "bind", MS_BIND, NULL); |
| mount("/etc/localtime", where, "bind", MS_BIND|MS_REMOUNT|MS_RDONLY, NULL); |
| free(where); |
| } |
| |
| return r; |
| } |
| |
| static int copy_devnodes(const char *dest, const char *console) { |
| |
| static const char devnodes[] = |
| "null\0" |
| "zero\0" |
| "full\0" |
| "random\0" |
| "urandom\0" |
| "tty\0" |
| "ptmx\0" |
| "kmsg\0" |
| "rtc0\0"; |
| |
| const char *d; |
| int r = 0, k; |
| mode_t u; |
| struct stat st; |
| char *from = NULL, *to = NULL; |
| |
| assert(dest); |
| assert(console); |
| |
| u = umask(0000); |
| |
| NULSTR_FOREACH(d, devnodes) { |
| from = to = NULL; |
| |
| asprintf(&from, "/dev/%s", d); |
| asprintf(&to, "%s/dev/%s", dest, d); |
| |
| if (!from || !to) { |
| log_error("Failed to allocate devnode path"); |
| |
| free(from); |
| free(to); |
| |
| from = to = NULL; |
| |
| if (r == 0) |
| r = -ENOMEM; |
| |
| break; |
| } |
| |
| if (stat(from, &st) < 0) { |
| |
| if (errno != ENOENT) { |
| log_error("Failed to stat %s: %m", from); |
| if (r == 0) |
| r = -errno; |
| } |
| |
| } 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); |
| if (r == 0) |
| r = -EIO; |
| |
| } else if (mknod(to, st.st_mode, st.st_rdev) < 0) { |
| |
| log_error("mknod(%s) failed: %m", dest); |
| if (r == 0) |
| r = -errno; |
| } |
| |
| free(from); |
| free(to); |
| } |
| |
| if (stat(console, &st) < 0) { |
| |
| log_error("Failed to stat %s: %m", console); |
| if (r == 0) |
| r = -errno; |
| |
| goto finish; |
| |
| } else if (!S_ISCHR(st.st_mode)) { |
| |
| log_error("/dev/console is not a char device."); |
| if (r == 0) |
| r = -EIO; |
| |
| goto finish; |
| } |
| |
| if (asprintf(&to, "%s/dev/console", dest) < 0) { |
| |
| log_error("Out of memory"); |
| if (r == 0) |
| r = -ENOMEM; |
| |
| goto finish; |
| } |
| |
| /* 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 device node first, that |
| * has the right major/minor (note that the major minor |
| * doesn't actually matter here, since we mount it over |
| * anyway). */ |
| |
| if (mknod(to, (st.st_mode & ~07777) | 0600, st.st_rdev) < 0) |
| log_error("mknod for /dev/console failed: %m"); |
| |
| if (mount(console, to, "bind", MS_BIND, NULL) < 0) { |
| log_error("bind mount for /dev/console failed: %m"); |
| |
| if (r == 0) |
| r = -errno; |
| } |
| |
| free(to); |
| |
| if ((k = chmod_and_chown(console, 0600, 0, 0)) < 0) { |
| log_error("Failed to correct access mode for TTY: %s", strerror(-k)); |
| |
| if (r == 0) |
| r = k; |
| } |
| |
| finish: |
| umask(u); |
| |
| return r; |
| } |
| |
| static int drop_capabilities(void) { |
| static const unsigned long retain[] = { |
| CAP_CHOWN, |
| CAP_DAC_OVERRIDE, |
| CAP_DAC_READ_SEARCH, |
| CAP_FOWNER, |
| CAP_FSETID, |
| CAP_IPC_OWNER, |
| CAP_KILL, |
| CAP_LEASE, |
| CAP_LINUX_IMMUTABLE, |
| CAP_NET_BIND_SERVICE, |
| CAP_NET_BROADCAST, |
| CAP_NET_RAW, |
| CAP_SETGID, |
| CAP_SETFCAP, |
| CAP_SETPCAP, |
| CAP_SETUID, |
| CAP_SYS_ADMIN, |
| CAP_SYS_CHROOT, |
| CAP_SYS_NICE, |
| CAP_SYS_PTRACE, |
| CAP_SYS_TTY_CONFIG |
| }; |
| |
| unsigned long l; |
| |
| for (l = 0; l <= MAX(63LU, (unsigned long) CAP_LAST_CAP); l++) { |
| unsigned i; |
| |
| for (i = 0; i < ELEMENTSOF(retain); i++) |
| if (retain[i] == l) |
| break; |
| |
| if (i < ELEMENTSOF(retain)) |
| continue; |
| |
| if (prctl(PR_CAPBSET_DROP, l) < 0) { |
| |
| /* If this capability is not known, EINVAL |
| * will be returned, let's ignore this. */ |
| if (errno == EINVAL) |
| break; |
| |
| log_error("PR_CAPBSET_DROP failed: %m"); |
| return -errno; |
| } |
| } |
| |
| return 0; |
| } |
| |
| static int is_os_tree(const char *path) { |
| int r; |
| char *p; |
| /* We use /bin/sh as flag file if something is an OS */ |
| |
| if (asprintf(&p, "%s/bin/sh", path) < 0) |
| return -ENOMEM; |
| |
| r = access(p, F_OK); |
| free(p); |
| |
| return r < 0 ? 0 : 1; |
| } |
| |
| #define BUFFER_SIZE 1024 |
| |
| static int process_pty(int master, sigset_t *mask) { |
| |
| char in_buffer[BUFFER_SIZE], out_buffer[BUFFER_SIZE]; |
| size_t in_buffer_full = 0, out_buffer_full = 0; |
| struct epoll_event stdin_ev, stdout_ev, master_ev, signal_ev; |
| bool stdin_readable = false, stdout_writable = false, master_readable = false, master_writable = false; |
| int ep = -1, signal_fd = -1, r; |
| |
| fd_nonblock(STDIN_FILENO, 1); |
| fd_nonblock(STDOUT_FILENO, 1); |
| fd_nonblock(master, 1); |
| |
| if ((signal_fd = signalfd(-1, mask, SFD_NONBLOCK|SFD_CLOEXEC)) < 0) { |
| log_error("signalfd(): %m"); |
| r = -errno; |
| goto finish; |
| } |
| |
| if ((ep = epoll_create1(EPOLL_CLOEXEC)) < 0) { |
| log_error("Failed to create epoll: %m"); |
| r = -errno; |
| goto finish; |
| } |
| |
| zero(stdin_ev); |
| stdin_ev.events = EPOLLIN|EPOLLET; |
| stdin_ev.data.fd = STDIN_FILENO; |
| |
| zero(stdout_ev); |
| stdout_ev.events = EPOLLOUT|EPOLLET; |
| stdout_ev.data.fd = STDOUT_FILENO; |
| |
| zero(master_ev); |
| master_ev.events = EPOLLIN|EPOLLOUT|EPOLLET; |
| master_ev.data.fd = master; |
| |
| zero(signal_ev); |
| signal_ev.events = EPOLLIN; |
| signal_ev.data.fd = signal_fd; |
| |
| if (epoll_ctl(ep, EPOLL_CTL_ADD, STDIN_FILENO, &stdin_ev) < 0 || |
| epoll_ctl(ep, EPOLL_CTL_ADD, STDOUT_FILENO, &stdout_ev) < 0 || |
| epoll_ctl(ep, EPOLL_CTL_ADD, master, &master_ev) < 0 || |
| epoll_ctl(ep, EPOLL_CTL_ADD, signal_fd, &signal_ev) < 0) { |
| log_error("Failed to regiser fds in epoll: %m"); |
| r = -errno; |
| goto finish; |
| } |
| |
| for (;;) { |
| struct epoll_event ev[16]; |
| ssize_t k; |
| int i, nfds; |
| |
| if ((nfds = epoll_wait(ep, ev, ELEMENTSOF(ev), -1)) < 0) { |
| |
| if (errno == EINTR || errno == EAGAIN) |
| continue; |
| |
| log_error("epoll_wait(): %m"); |
| r = -errno; |
| goto finish; |
| } |
| |
| assert(nfds >= 1); |
| |
| for (i = 0; i < nfds; i++) { |
| if (ev[i].data.fd == STDIN_FILENO) { |
| |
| if (ev[i].events & (EPOLLIN|EPOLLHUP)) |
| stdin_readable = true; |
| |
| } else if (ev[i].data.fd == STDOUT_FILENO) { |
| |
| if (ev[i].events & (EPOLLOUT|EPOLLHUP)) |
| stdout_writable = true; |
| |
| } else if (ev[i].data.fd == master) { |
| |
| if (ev[i].events & (EPOLLIN|EPOLLHUP)) |
| master_readable = true; |
| |
| if (ev[i].events & (EPOLLOUT|EPOLLHUP)) |
| master_writable = true; |
| |
| } else if (ev[i].data.fd == signal_fd) { |
| struct signalfd_siginfo sfsi; |
| ssize_t n; |
| |
| if ((n = read(signal_fd, &sfsi, sizeof(sfsi))) != sizeof(sfsi)) { |
| |
| if (n >= 0) { |
| log_error("Failed to read from signalfd: invalid block size"); |
| r = -EIO; |
| goto finish; |
| } |
| |
| if (errno != EINTR && errno != EAGAIN) { |
| log_error("Failed to read from signalfd: %m"); |
| r = -errno; |
| goto finish; |
| } |
| } else { |
| |
| if (sfsi.ssi_signo == SIGWINCH) { |
| struct winsize ws; |
| |
| /* The window size changed, let's forward that. */ |
| if (ioctl(STDIN_FILENO, TIOCGWINSZ, &ws) >= 0) |
| ioctl(master, TIOCSWINSZ, &ws); |
| } else { |
| r = 0; |
| goto finish; |
| } |
| } |
| } |
| } |
| |
| while ((stdin_readable && in_buffer_full <= 0) || |
| (master_writable && in_buffer_full > 0) || |
| (master_readable && out_buffer_full <= 0) || |
| (stdout_writable && out_buffer_full > 0)) { |
| |
| if (stdin_readable && in_buffer_full < BUFFER_SIZE) { |
| |
| if ((k = read(STDIN_FILENO, in_buffer + in_buffer_full, BUFFER_SIZE - in_buffer_full)) < 0) { |
| |
| if (errno == EAGAIN || errno == EPIPE || errno == ECONNRESET || errno == EIO) |
| stdin_readable = false; |
| else { |
| log_error("read(): %m"); |
| r = -errno; |
| goto finish; |
| } |
| } else |
| in_buffer_full += (size_t) k; |
| } |
| |
| if (master_writable && in_buffer_full > 0) { |
| |
| if ((k = write(master, in_buffer, in_buffer_full)) < 0) { |
| |
| if (errno == EAGAIN || errno == EPIPE || errno == ECONNRESET || errno == EIO) |
| master_writable = false; |
| else { |
| log_error("write(): %m"); |
| r = -errno; |
| goto finish; |
| } |
| |
| } else { |
| assert(in_buffer_full >= (size_t) k); |
| memmove(in_buffer, in_buffer + k, in_buffer_full - k); |
| in_buffer_full -= k; |
| } |
| } |
| |
| if (master_readable && out_buffer_full < BUFFER_SIZE) { |
| |
| if ((k = read(master, out_buffer + out_buffer_full, BUFFER_SIZE - out_buffer_full)) < 0) { |
| |
| if (errno == EAGAIN || errno == EPIPE || errno == ECONNRESET || errno == EIO) |
| master_readable = false; |
| else { |
| log_error("read(): %m"); |
| r = -errno; |
| goto finish; |
| } |
| } else |
| out_buffer_full += (size_t) k; |
| } |
| |
| if (stdout_writable && out_buffer_full > 0) { |
| |
| if ((k = write(STDOUT_FILENO, out_buffer, out_buffer_full)) < 0) { |
| |
| if (errno == EAGAIN || errno == EPIPE || errno == ECONNRESET || errno == EIO) |
| stdout_writable = false; |
| else { |
| log_error("write(): %m"); |
| r = -errno; |
| goto finish; |
| } |
| |
| } else { |
| assert(out_buffer_full >= (size_t) k); |
| memmove(out_buffer, out_buffer + k, out_buffer_full - k); |
| out_buffer_full -= k; |
| } |
| } |
| } |
| } |
| |
| finish: |
| if (ep >= 0) |
| close_nointr_nofail(ep); |
| |
| if (signal_fd >= 0) |
| close_nointr_nofail(signal_fd); |
| |
| return r; |
| } |
| |
| int main(int argc, char *argv[]) { |
| pid_t pid = 0; |
| int r = EXIT_FAILURE, k; |
| char *oldcg = NULL, *newcg = NULL; |
| int master = -1; |
| const char *console = NULL; |
| struct termios saved_attr, raw_attr; |
| sigset_t mask; |
| bool saved_attr_valid = false; |
| struct winsize ws; |
| |
| log_parse_environment(); |
| log_open(); |
| |
| if ((r = parse_argv(argc, argv)) <= 0) |
| goto finish; |
| |
| if (arg_directory) { |
| char *p; |
| |
| p = path_make_absolute_cwd(arg_directory); |
| free(arg_directory); |
| arg_directory = p; |
| } else |
| arg_directory = get_current_dir_name(); |
| |
| if (!arg_directory) { |
| log_error("Failed to determine path"); |
| goto finish; |
| } |
| |
| path_kill_slashes(arg_directory); |
| |
| if (geteuid() != 0) { |
| log_error("Need to be root."); |
| goto finish; |
| } |
| |
| if (sd_booted() <= 0) { |
| log_error("Not running on a systemd system."); |
| goto finish; |
| } |
| |
| if (path_equal(arg_directory, "/")) { |
| log_error("Spawning container on root directory not supported."); |
| goto finish; |
| } |
| |
| if (is_os_tree(arg_directory) <= 0) { |
| log_error("Directory %s doesn't look like an OS root directory. Refusing.", arg_directory); |
| goto finish; |
| } |
| |
| if ((k = cg_get_by_pid(SYSTEMD_CGROUP_CONTROLLER, 0, &oldcg)) < 0) { |
| log_error("Failed to determine current cgroup: %s", strerror(-k)); |
| goto finish; |
| } |
| |
| if (asprintf(&newcg, "%s/nspawn-%lu", oldcg, (unsigned long) getpid()) < 0) { |
| log_error("Failed to allocate cgroup path."); |
| goto finish; |
| } |
| |
| if ((k = cg_create_and_attach(SYSTEMD_CGROUP_CONTROLLER, newcg, 0)) < 0) { |
| log_error("Failed to create cgroup: %s", strerror(-k)); |
| goto finish; |
| } |
| |
| if ((master = posix_openpt(O_RDWR|O_NOCTTY|O_CLOEXEC|O_NDELAY)) < 0) { |
| log_error("Failed to acquire pseudo tty: %m"); |
| goto finish; |
| } |
| |
| if (!(console = ptsname(master))) { |
| log_error("Failed to determine tty name: %m"); |
| goto finish; |
| } |
| |
| log_info("Spawning namespace container on %s (console is %s).", arg_directory, console); |
| |
| if (ioctl(STDIN_FILENO, TIOCGWINSZ, &ws) >= 0) |
| ioctl(master, TIOCSWINSZ, &ws); |
| |
| if (unlockpt(master) < 0) { |
| log_error("Failed to unlock tty: %m"); |
| goto finish; |
| } |
| |
| if (tcgetattr(STDIN_FILENO, &saved_attr) < 0) { |
| log_error("Failed to get terminal attributes: %m"); |
| goto finish; |
| } |
| |
| saved_attr_valid = true; |
| |
| raw_attr = saved_attr; |
| cfmakeraw(&raw_attr); |
| raw_attr.c_lflag &= ~ECHO; |
| |
| if (tcsetattr(STDIN_FILENO, TCSANOW, &raw_attr) < 0) { |
| log_error("Failed to set terminal attributes: %m"); |
| goto finish; |
| } |
| |
| assert_se(sigemptyset(&mask) == 0); |
| sigset_add_many(&mask, SIGCHLD, SIGWINCH, SIGTERM, SIGINT, -1); |
| assert_se(sigprocmask(SIG_BLOCK, &mask, NULL) == 0); |
| |
| if ((pid = syscall(__NR_clone, SIGCHLD|CLONE_NEWIPC|CLONE_NEWNS|CLONE_NEWPID|CLONE_NEWUTS|(arg_private_network ? CLONE_NEWNET : 0), NULL)) < 0) { |
| log_error("clone() failed: %m"); |
| goto finish; |
| } |
| |
| if (pid == 0) { |
| /* child */ |
| |
| const char *hn; |
| const char *home = NULL; |
| uid_t uid = (uid_t) -1; |
| gid_t gid = (gid_t) -1; |
| const char *envp[] = { |
| "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin", |
| NULL, /* TERM */ |
| NULL, /* HOME */ |
| NULL, /* USER */ |
| NULL, /* LOGNAME */ |
| NULL |
| }; |
| |
| envp[1] = strv_find_prefix(environ, "TERM="); |
| |
| close_nointr_nofail(master); |
| |
| close_nointr(STDIN_FILENO); |
| close_nointr(STDOUT_FILENO); |
| close_nointr(STDERR_FILENO); |
| |
| close_all_fds(NULL, 0); |
| |
| reset_all_signal_handlers(); |
| |
| assert_se(sigemptyset(&mask) == 0); |
| assert_se(sigprocmask(SIG_SETMASK, &mask, NULL) == 0); |
| |
| if (setsid() < 0) |
| goto child_fail; |
| |
| if (prctl(PR_SET_PDEATHSIG, SIGKILL) < 0) |
| goto child_fail; |
| |
| /* Mark / as private, in case somebody marked it shared */ |
| if (mount(NULL, "/", NULL, MS_PRIVATE|MS_REC, NULL) < 0) |
| goto child_fail; |
| |
| if (mount_all(arg_directory) < 0) |
| goto child_fail; |
| |
| if (copy_devnodes(arg_directory, console) < 0) |
| goto child_fail; |
| |
| if (chdir(arg_directory) < 0) { |
| log_error("chdir(%s) failed: %m", arg_directory); |
| goto child_fail; |
| } |
| |
| if (open_terminal("dev/console", O_RDWR) != STDIN_FILENO || |
| dup2(STDIN_FILENO, STDOUT_FILENO) != STDOUT_FILENO || |
| dup2(STDIN_FILENO, STDERR_FILENO) != STDERR_FILENO) |
| goto child_fail; |
| |
| if (mount(arg_directory, "/", "bind", MS_BIND|MS_MOVE, NULL) < 0) { |
| log_error("mount(MS_MOVE) failed: %m"); |
| goto child_fail; |
| } |
| |
| if (chroot(".") < 0) { |
| log_error("chroot() failed: %m"); |
| goto child_fail; |
| } |
| |
| if (chdir("/") < 0) { |
| log_error("chdir() failed: %m"); |
| goto child_fail; |
| } |
| |
| umask(0022); |
| |
| loopback_setup(); |
| |
| if (drop_capabilities() < 0) |
| goto child_fail; |
| |
| if (arg_user) { |
| |
| if (get_user_creds((const char**)&arg_user, &uid, &gid, &home) < 0) { |
| log_error("get_user_creds() failed: %m"); |
| goto child_fail; |
| } |
| |
| if (mkdir_parents(home, 0775) < 0) { |
| log_error("mkdir_parents() failed: %m"); |
| goto child_fail; |
| } |
| |
| if (safe_mkdir(home, 0775, uid, gid) < 0) { |
| log_error("safe_mkdir() failed: %m"); |
| goto child_fail; |
| } |
| |
| if (initgroups((const char*)arg_user, gid) < 0) { |
| log_error("initgroups() failed: %m"); |
| goto child_fail; |
| } |
| |
| if (setresgid(gid, gid, gid) < 0) { |
| log_error("setregid() failed: %m"); |
| goto child_fail; |
| } |
| |
| if (setresuid(uid, uid, uid) < 0) { |
| log_error("setreuid() failed: %m"); |
| goto child_fail; |
| } |
| } |
| |
| if ((asprintf((char**)(envp + 2), "HOME=%s", home? home: "/root") < 0) || |
| (asprintf((char**)(envp + 3), "USER=%s", arg_user? arg_user : "root") < 0) || |
| (asprintf((char**)(envp + 4), "LOGNAME=%s", arg_user? arg_user : "root") < 0)) { |
| log_error("Out of memory"); |
| goto child_fail; |
| } |
| |
| if ((hn = file_name_from_path(arg_directory))) |
| sethostname(hn, strlen(hn)); |
| |
| if (argc > optind) |
| execvpe(argv[optind], argv + optind, (char**) envp); |
| else { |
| chdir(home ? home : "/root"); |
| execle("/bin/bash", "-bash", NULL, (char**) envp); |
| } |
| |
| log_error("execv() failed: %m"); |
| |
| child_fail: |
| _exit(EXIT_FAILURE); |
| } |
| |
| if (process_pty(master, &mask) < 0) |
| goto finish; |
| |
| if (saved_attr_valid) { |
| tcsetattr(STDIN_FILENO, TCSANOW, &saved_attr); |
| saved_attr_valid = false; |
| } |
| |
| r = wait_for_terminate_and_warn(argc > optind ? argv[optind] : "bash", pid); |
| |
| if (r < 0) |
| r = EXIT_FAILURE; |
| |
| finish: |
| if (saved_attr_valid) |
| tcsetattr(STDIN_FILENO, TCSANOW, &saved_attr); |
| |
| if (master >= 0) |
| close_nointr_nofail(master); |
| |
| if (oldcg) |
| cg_attach(SYSTEMD_CGROUP_CONTROLLER, oldcg, 0); |
| |
| if (newcg) |
| cg_kill_recursive_and_wait(SYSTEMD_CGROUP_CONTROLLER, newcg, true); |
| |
| free(arg_directory); |
| free(oldcg); |
| free(newcg); |
| |
| return r; |
| } |