| /*-*- 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 Lesser General Public License as published by |
| the Free Software Foundation; either version 2.1 of the License, or |
| (at your option) any later version. |
| |
| systemd is distributed in the hope that it will be useful, but |
| WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public License |
| along with systemd; If not, see <http://www.gnu.org/licenses/>. |
| ***/ |
| |
| #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 <sys/un.h> |
| #include <sys/socket.h> |
| |
| #include <systemd/sd-daemon.h> |
| |
| #include "log.h" |
| #include "util.h" |
| #include "mkdir.h" |
| #include "audit.h" |
| #include "missing.h" |
| #include "cgroup-util.h" |
| #include "strv.h" |
| #include "path-util.h" |
| #include "loopback-setup.h" |
| #include "sd-id128.h" |
| #include "dev-setup.h" |
| |
| typedef enum LinkJournal { |
| LINK_NO, |
| LINK_AUTO, |
| LINK_HOST, |
| LINK_GUEST |
| } LinkJournal; |
| |
| static char *arg_directory = NULL; |
| static char *arg_user = NULL; |
| static char **arg_controllers = NULL; |
| static char *arg_uuid = NULL; |
| static bool arg_private_network = false; |
| static bool arg_read_only = false; |
| static bool arg_boot = false; |
| static LinkJournal arg_link_journal = LINK_AUTO; |
| static uint64_t arg_retain = |
| (1ULL << CAP_CHOWN) | |
| (1ULL << CAP_DAC_OVERRIDE) | |
| (1ULL << CAP_DAC_READ_SEARCH) | |
| (1ULL << CAP_FOWNER) | |
| (1ULL << CAP_FSETID) | |
| (1ULL << CAP_IPC_OWNER) | |
| (1ULL << CAP_KILL) | |
| (1ULL << CAP_LEASE) | |
| (1ULL << CAP_LINUX_IMMUTABLE) | |
| (1ULL << CAP_NET_BIND_SERVICE) | |
| (1ULL << CAP_NET_BROADCAST) | |
| (1ULL << CAP_NET_RAW) | |
| (1ULL << CAP_SETGID) | |
| (1ULL << CAP_SETFCAP) | |
| (1ULL << CAP_SETPCAP) | |
| (1ULL << CAP_SETUID) | |
| (1ULL << CAP_SYS_ADMIN) | |
| (1ULL << CAP_SYS_CHROOT) | |
| (1ULL << CAP_SYS_NICE) | |
| (1ULL << CAP_SYS_PTRACE) | |
| (1ULL << CAP_SYS_TTY_CONFIG) | |
| (1ULL << CAP_SYS_RESOURCE); |
| |
| 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" |
| " -b --boot Boot up full system (i.e. invoke init)\n" |
| " -u --user=USER Run the command under specified user or uid\n" |
| " -C --controllers=LIST Put the container in specified comma-separated cgroup hierarchies\n" |
| " --uuid=UUID Set a specific machine UUID for the container\n" |
| " --private-network Disable network in container\n" |
| " --read-only Mount the root directory read-only\n" |
| " --capability=CAP In addition to the default, retain specified capability\n" |
| " --link-journal=MODE Link up guest journal, one of no, auto, guest, host\n" |
| " -j Equivalent to --link-journal=host\n", |
| program_invocation_short_name); |
| |
| return 0; |
| } |
| |
| static int parse_argv(int argc, char *argv[]) { |
| |
| enum { |
| ARG_PRIVATE_NETWORK = 0x100, |
| ARG_UUID, |
| ARG_READ_ONLY, |
| ARG_CAPABILITY, |
| ARG_LINK_JOURNAL |
| }; |
| |
| static const struct option options[] = { |
| { "help", no_argument, NULL, 'h' }, |
| { "directory", required_argument, NULL, 'D' }, |
| { "user", required_argument, NULL, 'u' }, |
| { "controllers", required_argument, NULL, 'C' }, |
| { "private-network", no_argument, NULL, ARG_PRIVATE_NETWORK }, |
| { "boot", no_argument, NULL, 'b' }, |
| { "uuid", required_argument, NULL, ARG_UUID }, |
| { "read-only", no_argument, NULL, ARG_READ_ONLY }, |
| { "capability", required_argument, NULL, ARG_CAPABILITY }, |
| { "link-journal", required_argument, NULL, ARG_LINK_JOURNAL }, |
| { NULL, 0, NULL, 0 } |
| }; |
| |
| int c; |
| |
| assert(argc >= 0); |
| assert(argv); |
| |
| while ((c = getopt_long(argc, argv, "+hD:u:C:bj", options, NULL)) >= 0) { |
| |
| switch (c) { |
| |
| case 'h': |
| help(); |
| return 0; |
| |
| case 'D': |
| free(arg_directory); |
| arg_directory = canonicalize_file_name(optarg); |
| if (!arg_directory) { |
| log_error("Failed to canonicalize 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 'C': |
| strv_free(arg_controllers); |
| arg_controllers = strv_split(optarg, ","); |
| if (!arg_controllers) { |
| log_error("Failed to split controllers list."); |
| return -ENOMEM; |
| } |
| strv_uniq(arg_controllers); |
| |
| break; |
| |
| case ARG_PRIVATE_NETWORK: |
| arg_private_network = true; |
| break; |
| |
| case 'b': |
| arg_boot = true; |
| break; |
| |
| case ARG_UUID: |
| arg_uuid = optarg; |
| break; |
| |
| case ARG_READ_ONLY: |
| arg_read_only = true; |
| break; |
| |
| case ARG_CAPABILITY: { |
| char *state, *word; |
| size_t length; |
| |
| FOREACH_WORD_SEPARATOR(word, length, optarg, ",", state) { |
| cap_value_t cap; |
| char *t; |
| |
| t = strndup(word, length); |
| if (!t) |
| return log_oom(); |
| |
| if (cap_from_name(t, &cap) < 0) { |
| log_error("Failed to parse capability %s.", t); |
| free(t); |
| return -EINVAL; |
| } |
| |
| free(t); |
| arg_retain |= 1ULL << (uint64_t) cap; |
| } |
| |
| break; |
| } |
| |
| case 'j': |
| arg_link_journal = LINK_GUEST; |
| break; |
| |
| case ARG_LINK_JOURNAL: |
| if (streq(optarg, "auto")) |
| arg_link_journal = LINK_AUTO; |
| else if (streq(optarg, "no")) |
| arg_link_journal = LINK_NO; |
| else if (streq(optarg, "guest")) |
| arg_link_journal = LINK_GUEST; |
| else if (streq(optarg, "host")) |
| arg_link_journal = LINK_HOST; |
| else { |
| log_error("Failed to parse link journal mode %s", optarg); |
| return -EINVAL; |
| } |
| |
| 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", NULL, NULL, MS_BIND, true }, /* Bind mount first */ |
| { NULL, "/proc/sys", NULL, NULL, MS_BIND|MS_RDONLY|MS_REMOUNT, true }, /* Then, make it r/o */ |
| { "/sys", "/sys", NULL, NULL, MS_BIND, true }, /* Bind mount first */ |
| { NULL, "/sys", NULL, NULL, MS_BIND|MS_RDONLY|MS_REMOUNT, true }, /* Then, make it r/o */ |
| { "tmpfs", "/dev", "tmpfs", "mode=755", MS_NOSUID|MS_STRICTATIME, true }, |
| { "/dev/pts", "/dev/pts", NULL, NULL, MS_BIND, true }, |
| { "tmpfs", "/run", "tmpfs", "mode=755", MS_NOSUID|MS_NODEV|MS_STRICTATIME, true }, |
| #ifdef HAVE_SELINUX |
| { "/sys/fs/selinux", "/sys/fs/selinux", NULL, NULL, MS_BIND, false }, /* Bind mount first */ |
| { NULL, "/sys/fs/selinux", NULL, 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_oom(); |
| |
| if (r == 0) |
| r = -ENOMEM; |
| |
| break; |
| } |
| |
| t = path_is_mount_point(where, false); |
| if (t < 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_label(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); |
| } |
| |
| return r; |
| } |
| |
| static int setup_timezone(const char *dest) { |
| char *where; |
| |
| assert(dest); |
| |
| /* Fix the timezone, if possible */ |
| if (asprintf(&where, "%s/etc/localtime", dest) < 0) |
| return log_oom(); |
| |
| if (mount("/etc/localtime", where, "bind", MS_BIND, NULL) >= 0) |
| mount("/etc/localtime", where, "bind", MS_BIND|MS_REMOUNT|MS_RDONLY, NULL); |
| |
| free(where); |
| |
| if (asprintf(&where, "%s/etc/timezone", dest) < 0) |
| return log_oom(); |
| |
| if (mount("/etc/timezone", where, "bind", MS_BIND, NULL) >= 0) |
| mount("/etc/timezone", where, "bind", MS_BIND|MS_REMOUNT|MS_RDONLY, NULL); |
| |
| free(where); |
| |
| return 0; |
| } |
| |
| static int setup_resolv_conf(const char *dest) { |
| char *where; |
| |
| assert(dest); |
| |
| if (arg_private_network) |
| return 0; |
| |
| /* Fix resolv.conf, if possible */ |
| if (asprintf(&where, "%s/etc/resolv.conf", dest) < 0) { |
| return log_oom(); |
| } |
| |
| if (mount("/etc/resolv.conf", where, "bind", MS_BIND, NULL) >= 0) |
| mount("/etc/resolv.conf", where, "bind", MS_BIND|MS_REMOUNT|MS_RDONLY, NULL); |
| |
| free(where); |
| |
| return 0; |
| } |
| |
| static int copy_devnodes(const char *dest) { |
| |
| static const char devnodes[] = |
| "null\0" |
| "zero\0" |
| "full\0" |
| "random\0" |
| "urandom\0" |
| "tty\0" |
| "ptmx\0" |
| "rtc0\0"; |
| |
| const char *d; |
| int r = 0; |
| mode_t u; |
| |
| assert(dest); |
| |
| u = umask(0000); |
| |
| NULSTR_FOREACH(d, devnodes) { |
| struct stat st; |
| char *from = NULL, *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); |
| } |
| |
| umask(u); |
| |
| return r; |
| } |
| |
| static int setup_dev_console(const char *dest, const char *console) { |
| struct stat st; |
| char *to = NULL; |
| int r; |
| mode_t u; |
| |
| assert(dest); |
| assert(console); |
| |
| u = umask(0000); |
| |
| if (stat(console, &st) < 0) { |
| log_error("Failed to stat %s: %m", console); |
| r = -errno; |
| goto finish; |
| |
| } else if (!S_ISCHR(st.st_mode)) { |
| log_error("/dev/console is not a char device."); |
| r = -EIO; |
| goto finish; |
| } |
| |
| r = chmod_and_chown(console, 0600, 0, 0); |
| if (r < 0) { |
| log_error("Failed to correct access mode for TTY: %s", strerror(-r)); |
| goto finish; |
| } |
| |
| if (asprintf(&to, "%s/dev/console", dest) < 0) { |
| r = log_oom(); |
| 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"); |
| r = -errno; |
| goto finish; |
| } |
| |
| if (mount(console, to, "bind", MS_BIND, NULL) < 0) { |
| log_error("Bind mount for /dev/console failed: %m"); |
| r = -errno; |
| goto finish; |
| } |
| |
| finish: |
| free(to); |
| umask(u); |
| |
| return r; |
| } |
| |
| static int setup_kmsg(const char *dest, int kmsg_socket) { |
| char *from = NULL, *to = NULL; |
| int r, fd, k; |
| mode_t u; |
| union { |
| struct cmsghdr cmsghdr; |
| uint8_t buf[CMSG_SPACE(sizeof(int))]; |
| } control; |
| struct msghdr mh; |
| struct cmsghdr *cmsg; |
| |
| assert(dest); |
| assert(kmsg_socket >= 0); |
| |
| u = umask(0000); |
| |
| /* We create the kmsg FIFO as /dev/kmsg, but immediately |
| * delete it after bind mounting it to /proc/kmsg. While FIFOs |
| * on the reading side behave very similar to /proc/kmsg, |
| * their writing side behaves differently from /dev/kmsg in |
| * that writing blocks when nothing is reading. In order to |
| * avoid any problems with containers deadlocking due to this |
| * we simply make /dev/kmsg unavailable to the container. */ |
| if (asprintf(&from, "%s/dev/kmsg", dest) < 0) { |
| r = log_oom(); |
| goto finish; |
| } |
| |
| if (asprintf(&to, "%s/proc/kmsg", dest) < 0) { |
| r = log_oom(); |
| goto finish; |
| } |
| |
| if (mkfifo(from, 0600) < 0) { |
| log_error("mkfifo() for /dev/kmsg failed: %m"); |
| r = -errno; |
| goto finish; |
| } |
| |
| r = chmod_and_chown(from, 0600, 0, 0); |
| if (r < 0) { |
| log_error("Failed to correct access mode for /dev/kmsg: %s", strerror(-r)); |
| goto finish; |
| } |
| |
| if (mount(from, to, "bind", MS_BIND, NULL) < 0) { |
| log_error("Bind mount for /proc/kmsg failed: %m"); |
| r = -errno; |
| goto finish; |
| } |
| |
| fd = open(from, O_RDWR|O_NDELAY|O_CLOEXEC); |
| if (fd < 0) { |
| log_error("Failed to open fifo: %m"); |
| r = -errno; |
| goto finish; |
| } |
| |
| zero(mh); |
| zero(control); |
| |
| mh.msg_control = &control; |
| mh.msg_controllen = sizeof(control); |
| |
| cmsg = CMSG_FIRSTHDR(&mh); |
| cmsg->cmsg_level = SOL_SOCKET; |
| cmsg->cmsg_type = SCM_RIGHTS; |
| cmsg->cmsg_len = CMSG_LEN(sizeof(int)); |
| memcpy(CMSG_DATA(cmsg), &fd, sizeof(int)); |
| |
| mh.msg_controllen = cmsg->cmsg_len; |
| |
| /* Store away the fd in the socket, so that it stays open as |
| * long as we run the child */ |
| k = sendmsg(kmsg_socket, &mh, MSG_DONTWAIT|MSG_NOSIGNAL); |
| close_nointr_nofail(fd); |
| |
| if (k < 0) { |
| log_error("Failed to send FIFO fd: %m"); |
| r = -errno; |
| goto finish; |
| } |
| |
| /* And now make the FIFO unavailable as /dev/kmsg... */ |
| unlink(from); |
| |
| finish: |
| free(from); |
| free(to); |
| umask(u); |
| |
| return r; |
| } |
| |
| static int setup_hostname(void) { |
| char *hn; |
| int r = 0; |
| |
| hn = path_get_file_name(arg_directory); |
| if (hn) { |
| hn = strdup(hn); |
| if (!hn) |
| return -ENOMEM; |
| |
| hostname_cleanup(hn); |
| |
| if (!isempty(hn)) |
| if (sethostname(hn, strlen(hn)) < 0) |
| r = -errno; |
| |
| free(hn); |
| } |
| |
| return r; |
| } |
| |
| static int setup_journal(const char *directory) { |
| sd_id128_t machine_id; |
| char *p = NULL, *b = NULL, *l, *q = NULL, *d = NULL; |
| int r; |
| |
| if (arg_link_journal == LINK_NO) |
| return 0; |
| |
| p = strappend(directory, "/etc/machine-id"); |
| if (!p) { |
| r = log_oom(); |
| goto finish; |
| } |
| |
| r = read_one_line_file(p, &b); |
| if (r == -ENOENT && arg_link_journal == LINK_AUTO) { |
| r = 0; |
| goto finish; |
| } else if (r < 0) { |
| log_error("Failed to read machine ID: %s", strerror(-r)); |
| return r; |
| } |
| |
| l = strstrip(b); |
| if (isempty(l) && arg_link_journal == LINK_AUTO) { |
| r = 0; |
| goto finish; |
| } |
| |
| /* Verify validaty */ |
| r = sd_id128_from_string(l, &machine_id); |
| if (r < 0) { |
| log_error("Failed to parse machine ID: %s", strerror(-r)); |
| goto finish; |
| } |
| |
| free(p); |
| p = strappend("/var/log/journal/", l); |
| q = strjoin(directory, "/var/log/journal/", l, NULL); |
| if (!p || !q) { |
| r = log_oom(); |
| goto finish; |
| } |
| |
| if (path_is_mount_point(p, false) > 0 || |
| path_is_mount_point(q, false) > 0) { |
| if (arg_link_journal != LINK_AUTO) { |
| log_error("Journal already a mount point, refusing."); |
| r = -EEXIST; |
| goto finish; |
| } |
| |
| r = 0; |
| goto finish; |
| } |
| |
| r = readlink_and_make_absolute(p, &d); |
| if (r >= 0) { |
| if ((arg_link_journal == LINK_GUEST || |
| arg_link_journal == LINK_AUTO) && |
| path_equal(d, q)) { |
| |
| mkdir_p(q, 0755); |
| |
| r = 0; |
| goto finish; |
| } |
| |
| if (unlink(p) < 0) { |
| log_error("Failed to remove symlink %s: %m", p); |
| r = -errno; |
| goto finish; |
| } |
| } else if (r == -EINVAL) { |
| |
| if (arg_link_journal == LINK_GUEST && |
| rmdir(p) < 0) { |
| |
| if (errno == ENOTDIR) |
| log_error("%s already exists and is neither symlink nor directory.", p); |
| else { |
| log_error("Failed to remove %s: %m", p); |
| r = -errno; |
| } |
| |
| goto finish; |
| } |
| } else if (r != -ENOENT) { |
| log_error("readlink(%s) failed: %m", p); |
| goto finish; |
| } |
| |
| if (arg_link_journal == LINK_GUEST) { |
| |
| if (symlink(q, p) < 0) { |
| log_error("Failed to symlink %s to %s: %m", q, p); |
| r = -errno; |
| goto finish; |
| } |
| |
| mkdir_p(q, 0755); |
| |
| r = 0; |
| goto finish; |
| } |
| |
| if (arg_link_journal == LINK_HOST) { |
| r = mkdir_p(p, 0755); |
| if (r < 0) { |
| log_error("Failed to create %s: %m", p); |
| goto finish; |
| } |
| |
| } else if (access(p, F_OK) < 0) { |
| r = 0; |
| goto finish; |
| } |
| |
| if (dir_is_empty(q) == 0) { |
| log_error("%s not empty.", q); |
| r = -ENOTEMPTY; |
| goto finish; |
| } |
| |
| r = mkdir_p(q, 0755); |
| if (r < 0) { |
| log_error("Failed to create %s: %m", q); |
| goto finish; |
| } |
| |
| if (mount(p, q, "bind", MS_BIND, NULL) < 0) { |
| log_error("Failed to bind mount journal from host into guest: %m"); |
| r = -errno; |
| goto finish; |
| } |
| |
| r = 0; |
| |
| finish: |
| free(p); |
| free(q); |
| free(d); |
| free(b); |
| return r; |
| |
| } |
| |
| static int drop_capabilities(void) { |
| return capability_bounding_set_drop(~arg_retain, false); |
| } |
| |
| 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; |
| } |
| |
| static int process_pty(int master, sigset_t *mask) { |
| |
| char in_buffer[LINE_MAX], out_buffer[LINE_MAX]; |
| 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); |
| |
| signal_fd = signalfd(-1, mask, SFD_NONBLOCK|SFD_CLOEXEC); |
| if (signal_fd < 0) { |
| log_error("signalfd(): %m"); |
| r = -errno; |
| goto finish; |
| } |
| |
| ep = epoll_create1(EPOLL_CLOEXEC); |
| if (ep < 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; |
| |
| nfds = epoll_wait(ep, ev, ELEMENTSOF(ev), -1); |
| if (nfds < 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; |
| |
| n = read(signal_fd, &sfsi, sizeof(sfsi)); |
| if (n != 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 < LINE_MAX) { |
| |
| k = read(STDIN_FILENO, in_buffer + in_buffer_full, LINE_MAX - in_buffer_full); |
| if (k < 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) { |
| |
| k = write(master, in_buffer, in_buffer_full); |
| if (k < 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 < LINE_MAX) { |
| |
| k = read(master, out_buffer + out_buffer_full, LINE_MAX - out_buffer_full); |
| if (k < 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) { |
| |
| k = write(STDOUT_FILENO, out_buffer, out_buffer_full); |
| if (k < 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; |
| char **controller = 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; |
| int kmsg_socket_pair[2] = { -1, -1 }; |
| |
| log_parse_environment(); |
| log_open(); |
| |
| r = parse_argv(argc, argv); |
| if (r <= 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; |
| } |
| |
| k = cg_get_by_pid(SYSTEMD_CGROUP_CONTROLLER, 0, &oldcg); |
| if (k < 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; |
| } |
| |
| k = cg_create_and_attach(SYSTEMD_CGROUP_CONTROLLER, newcg, 0); |
| if (k < 0) { |
| log_error("Failed to create cgroup: %s", strerror(-k)); |
| goto finish; |
| } |
| |
| STRV_FOREACH(controller, arg_controllers) { |
| k = cg_create_and_attach(*controller, newcg, 0); |
| if (k < 0) |
| log_warning("Failed to create cgroup in controller %s: %s", *controller, strerror(-k)); |
| } |
| |
| master = posix_openpt(O_RDWR|O_NOCTTY|O_CLOEXEC|O_NDELAY); |
| if (master < 0) { |
| log_error("Failed to acquire pseudo tty: %m"); |
| goto finish; |
| } |
| |
| console = ptsname(master); |
| if (!console) { |
| 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; |
| } |
| |
| if (socketpair(AF_UNIX, SOCK_DGRAM|SOCK_NONBLOCK|SOCK_CLOEXEC, 0, kmsg_socket_pair) < 0) { |
| log_error("Failed to create kmsg socket pair"); |
| goto finish; |
| } |
| |
| assert_se(sigemptyset(&mask) == 0); |
| sigset_add_many(&mask, SIGCHLD, SIGWINCH, SIGTERM, SIGINT, -1); |
| assert_se(sigprocmask(SIG_BLOCK, &mask, NULL) == 0); |
| |
| pid = syscall(__NR_clone, SIGCHLD|CLONE_NEWIPC|CLONE_NEWNS|CLONE_NEWPID|CLONE_NEWUTS|(arg_private_network ? CLONE_NEWNET : 0), NULL); |
| if (pid < 0) { |
| if (errno == EINVAL) |
| log_error("clone() failed, do you have namespace support enabled in your kernel? (You need UTS, IPC, PID and NET namespacing built in): %m"); |
| else |
| log_error("clone() failed: %m"); |
| |
| goto finish; |
| } |
| |
| if (pid == 0) { |
| /* child */ |
| |
| 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", |
| "container=systemd-nspawn", /* LXC sets container=lxc, so follow the scheme here */ |
| NULL, /* TERM */ |
| NULL, /* HOME */ |
| NULL, /* USER */ |
| NULL, /* LOGNAME */ |
| NULL, /* container_uuid */ |
| NULL |
| }; |
| |
| envp[2] = strv_find_prefix(environ, "TERM="); |
| |
| close_nointr_nofail(master); |
| |
| close_nointr(STDIN_FILENO); |
| close_nointr(STDOUT_FILENO); |
| close_nointr(STDERR_FILENO); |
| |
| close_all_fds(&kmsg_socket_pair[1], 1); |
| |
| reset_all_signal_handlers(); |
| |
| assert_se(sigemptyset(&mask) == 0); |
| assert_se(sigprocmask(SIG_SETMASK, &mask, NULL) == 0); |
| |
| if (open_terminal(console, O_RDWR) != STDIN_FILENO || |
| dup2(STDIN_FILENO, STDOUT_FILENO) != STDOUT_FILENO || |
| dup2(STDIN_FILENO, STDERR_FILENO) != STDERR_FILENO) |
| goto child_fail; |
| |
| if (setsid() < 0) { |
| log_error("setsid() failed: %m"); |
| goto child_fail; |
| } |
| |
| if (prctl(PR_SET_PDEATHSIG, SIGKILL) < 0) { |
| log_error("PR_SET_PDEATHSIG failed: %m"); |
| goto child_fail; |
| } |
| |
| /* Mark everything as slave, so that we still |
| * receive mounts from the real root, but don't |
| * propagate mounts to the real root. */ |
| if (mount(NULL, "/", NULL, MS_SLAVE|MS_REC, NULL) < 0) { |
| log_error("MS_SLAVE|MS_REC failed: %m"); |
| goto child_fail; |
| } |
| |
| /* Turn directory into bind mount */ |
| if (mount(arg_directory, arg_directory, "bind", MS_BIND|MS_REC, NULL) < 0) { |
| log_error("Failed to make bind mount."); |
| goto child_fail; |
| } |
| |
| if (arg_read_only) |
| if (mount(arg_directory, arg_directory, "bind", MS_BIND|MS_REMOUNT|MS_RDONLY|MS_REC, NULL) < 0) { |
| log_error("Failed to make read-only."); |
| goto child_fail; |
| } |
| |
| if (mount_all(arg_directory) < 0) |
| goto child_fail; |
| |
| if (copy_devnodes(arg_directory) < 0) |
| goto child_fail; |
| |
| dev_setup(arg_directory); |
| |
| if (setup_dev_console(arg_directory, console) < 0) |
| goto child_fail; |
| |
| if (setup_kmsg(arg_directory, kmsg_socket_pair[1]) < 0) |
| goto child_fail; |
| |
| close_nointr_nofail(kmsg_socket_pair[1]); |
| |
| if (setup_timezone(arg_directory) < 0) |
| goto child_fail; |
| |
| if (setup_resolv_conf(arg_directory) < 0) |
| goto child_fail; |
| |
| if (setup_journal(arg_directory) < 0) |
| goto child_fail; |
| |
| if (chdir(arg_directory) < 0) { |
| log_error("chdir(%s) failed: %m", arg_directory); |
| goto child_fail; |
| } |
| |
| if (mount(arg_directory, "/", NULL, 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) { |
| log_error("drop_capabilities() failed: %m"); |
| goto child_fail; |
| } |
| |
| if (arg_user) { |
| |
| if (get_user_creds((const char**)&arg_user, &uid, &gid, &home, NULL) < 0) { |
| log_error("get_user_creds() failed: %m"); |
| goto child_fail; |
| } |
| |
| if (mkdir_parents_label(home, 0775) < 0) { |
| log_error("mkdir_parents_label() failed: %m"); |
| goto child_fail; |
| } |
| |
| if (mkdir_safe_label(home, 0775, uid, gid) < 0) { |
| log_error("mkdir_safe_label() 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 + 3), "HOME=%s", home ? home: "/root") < 0) || |
| (asprintf((char**)(envp + 4), "USER=%s", arg_user ? arg_user : "root") < 0) || |
| (asprintf((char**)(envp + 5), "LOGNAME=%s", arg_user ? arg_user : "root") < 0)) { |
| log_oom(); |
| goto child_fail; |
| } |
| |
| if (arg_uuid) { |
| if (asprintf((char**)(envp + 6), "container_uuid=%s", arg_uuid) < 0) { |
| log_oom(); |
| goto child_fail; |
| } |
| } |
| |
| setup_hostname(); |
| |
| if (arg_boot) { |
| char **a; |
| size_t l; |
| |
| /* Automatically search for the init system */ |
| |
| l = 1 + argc - optind; |
| a = newa(char*, l + 1); |
| memcpy(a + 1, argv + optind, l * sizeof(char*)); |
| |
| a[0] = (char*) "/usr/lib/systemd/systemd"; |
| execve(a[0], a, (char**) envp); |
| |
| a[0] = (char*) "/lib/systemd/systemd"; |
| execve(a[0], a, (char**) envp); |
| |
| a[0] = (char*) "/sbin/init"; |
| execve(a[0], a, (char**) envp); |
| } else 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); |
| |
| close_pipe(kmsg_socket_pair); |
| |
| if (oldcg) |
| cg_attach(SYSTEMD_CGROUP_CONTROLLER, oldcg, 0); |
| |
| if (newcg) |
| cg_kill_recursive_and_wait(SYSTEMD_CGROUP_CONTROLLER, newcg, true); |
| |
| free(arg_directory); |
| strv_free(arg_controllers); |
| free(oldcg); |
| free(newcg); |
| |
| return r; |
| } |