diff options
author | Luke Shumaker <lukeshu@sbcglobal.net> | 2016-07-30 11:51:52 -0400 |
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committer | Luke Shumaker <lukeshu@sbcglobal.net> | 2016-07-30 11:51:52 -0400 |
commit | 2bd52fb107528d459dabd5929794987c01a7270e (patch) | |
tree | e01842ceb4617c06dee673c2a09dd4707ae33ab8 /src/libcore/namespace.c | |
parent | 1ed649627c5dbf9254f325c8254bfa69c31466c9 (diff) |
stuff
Diffstat (limited to 'src/libcore/namespace.c')
-rw-r--r-- | src/libcore/namespace.c | 650 |
1 files changed, 0 insertions, 650 deletions
diff --git a/src/libcore/namespace.c b/src/libcore/namespace.c deleted file mode 100644 index f7c5364437..0000000000 --- a/src/libcore/namespace.c +++ /dev/null @@ -1,650 +0,0 @@ -/*** - 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 <errno.h> -#include <sched.h> -#include <stdio.h> -#include <string.h> -#include <sys/mount.h> -#include <sys/stat.h> -#include <unistd.h> -#include <linux/fs.h> - -#include "basic/alloc-util.h" -#include "shared/dev-setup.h" -#include "basic/fd-util.h" -#include "loopback-setup.h" -#include "basic/missing.h" -#include "basic/mkdir.h" -#include "basic/mount-util.h" -#include "namespace.h" -#include "basic/path-util.h" -#include "basic/selinux-util.h" -#include "basic/socket-util.h" -#include "basic/string-table.h" -#include "basic/string-util.h" -#include "basic/strv.h" -#include "basic/umask-util.h" -#include "basic/user-util.h" -#include "basic/util.h" - -#define DEV_MOUNT_OPTIONS (MS_NOSUID|MS_STRICTATIME|MS_NOEXEC) - -typedef enum MountMode { - /* This is ordered by priority! */ - INACCESSIBLE, - READONLY, - PRIVATE_TMP, - PRIVATE_VAR_TMP, - PRIVATE_DEV, - READWRITE -} MountMode; - -typedef struct BindMount { - const char *path; - MountMode mode; - bool done; - bool ignore; -} BindMount; - -static int append_mounts(BindMount **p, char **strv, MountMode mode) { - char **i; - - assert(p); - - STRV_FOREACH(i, strv) { - - (*p)->ignore = false; - (*p)->done = false; - - if ((mode == INACCESSIBLE || mode == READONLY || mode == READWRITE) && (*i)[0] == '-') { - (*p)->ignore = true; - (*i)++; - } - - if (!path_is_absolute(*i)) - return -EINVAL; - - (*p)->path = *i; - (*p)->mode = mode; - (*p)++; - } - - return 0; -} - -static int mount_path_compare(const void *a, const void *b) { - const BindMount *p = a, *q = b; - int d; - - d = path_compare(p->path, q->path); - - if (d == 0) { - /* If the paths are equal, check the mode */ - if (p->mode < q->mode) - return -1; - - if (p->mode > q->mode) - return 1; - - return 0; - } - - /* If the paths are not equal, then order prefixes first */ - return d; -} - -static void drop_duplicates(BindMount *m, unsigned *n) { - BindMount *f, *t, *previous; - - assert(m); - assert(n); - - for (f = m, t = m, previous = NULL; f < m+*n; f++) { - - /* The first one wins */ - if (previous && path_equal(f->path, previous->path)) - continue; - - *t = *f; - - previous = t; - - t++; - } - - *n = t - m; -} - -static int mount_dev(BindMount *m) { - static const char devnodes[] = - "/dev/null\0" - "/dev/zero\0" - "/dev/full\0" - "/dev/random\0" - "/dev/urandom\0" - "/dev/tty\0"; - - char temporary_mount[] = "/tmp/namespace-dev-XXXXXX"; - const char *d, *dev = NULL, *devpts = NULL, *devshm = NULL, *devhugepages = NULL, *devmqueue = NULL, *devlog = NULL, *devptmx = NULL; - _cleanup_umask_ mode_t u; - int r; - - assert(m); - - u = umask(0000); - - if (!mkdtemp(temporary_mount)) - return -errno; - - dev = strjoina(temporary_mount, "/dev"); - (void) mkdir(dev, 0755); - if (mount("tmpfs", dev, "tmpfs", DEV_MOUNT_OPTIONS, "mode=755") < 0) { - r = -errno; - goto fail; - } - - devpts = strjoina(temporary_mount, "/dev/pts"); - (void) mkdir(devpts, 0755); - if (mount("/dev/pts", devpts, NULL, MS_BIND, NULL) < 0) { - r = -errno; - goto fail; - } - - devptmx = strjoina(temporary_mount, "/dev/ptmx"); - if (symlink("pts/ptmx", devptmx) < 0) { - r = -errno; - goto fail; - } - - devshm = strjoina(temporary_mount, "/dev/shm"); - (void) mkdir(devshm, 01777); - r = mount("/dev/shm", devshm, NULL, MS_BIND, NULL); - if (r < 0) { - r = -errno; - goto fail; - } - - devmqueue = strjoina(temporary_mount, "/dev/mqueue"); - (void) mkdir(devmqueue, 0755); - (void) mount("/dev/mqueue", devmqueue, NULL, MS_BIND, NULL); - - devhugepages = strjoina(temporary_mount, "/dev/hugepages"); - (void) mkdir(devhugepages, 0755); - (void) mount("/dev/hugepages", devhugepages, NULL, MS_BIND, NULL); - - devlog = strjoina(temporary_mount, "/dev/log"); - (void) symlink("/run/systemd/journal/dev-log", devlog); - - NULSTR_FOREACH(d, devnodes) { - _cleanup_free_ char *dn = NULL; - struct stat st; - - r = stat(d, &st); - if (r < 0) { - - if (errno == ENOENT) - continue; - - r = -errno; - goto fail; - } - - if (!S_ISBLK(st.st_mode) && - !S_ISCHR(st.st_mode)) { - r = -EINVAL; - goto fail; - } - - if (st.st_rdev == 0) - continue; - - dn = strappend(temporary_mount, d); - if (!dn) { - r = -ENOMEM; - goto fail; - } - - mac_selinux_create_file_prepare(d, st.st_mode); - r = mknod(dn, st.st_mode, st.st_rdev); - mac_selinux_create_file_clear(); - - if (r < 0) { - r = -errno; - goto fail; - } - } - - dev_setup(temporary_mount, UID_INVALID, GID_INVALID); - - /* Create the /dev directory if missing. It is more likely to be - * missing when the service is started with RootDirectory. This is - * consistent with mount units creating the mount points when missing. - */ - (void) mkdir_p_label(m->path, 0755); - - /* Unmount everything in old /dev */ - umount_recursive(m->path, 0); - if (mount(dev, m->path, NULL, MS_MOVE, NULL) < 0) { - r = -errno; - goto fail; - } - - rmdir(dev); - rmdir(temporary_mount); - - return 0; - -fail: - if (devpts) - umount(devpts); - - if (devshm) - umount(devshm); - - if (devhugepages) - umount(devhugepages); - - if (devmqueue) - umount(devmqueue); - - umount(dev); - rmdir(dev); - rmdir(temporary_mount); - - return r; -} - -static int apply_mount( - BindMount *m, - const char *tmp_dir, - const char *var_tmp_dir) { - - const char *what; - int r; - - assert(m); - - switch (m->mode) { - - case INACCESSIBLE: - - /* First, get rid of everything that is below if there - * is anything... Then, overmount it with an - * inaccessible directory. */ - umount_recursive(m->path, 0); - - what = "/run/systemd/inaccessible"; - break; - - case READONLY: - case READWRITE: - /* Nothing to mount here, we just later toggle the - * MS_RDONLY bit for the mount point */ - return 0; - - case PRIVATE_TMP: - what = tmp_dir; - break; - - case PRIVATE_VAR_TMP: - what = var_tmp_dir; - break; - - case PRIVATE_DEV: - return mount_dev(m); - - default: - assert_not_reached("Unknown mode"); - } - - assert(what); - - r = mount(what, m->path, NULL, MS_BIND|MS_REC, NULL); - if (r >= 0) - log_debug("Successfully mounted %s to %s", what, m->path); - else if (m->ignore && errno == ENOENT) - return 0; - - return r; -} - -static int make_read_only(BindMount *m) { - int r; - - assert(m); - - if (IN_SET(m->mode, INACCESSIBLE, READONLY)) - r = bind_remount_recursive(m->path, true); - else if (IN_SET(m->mode, READWRITE, PRIVATE_TMP, PRIVATE_VAR_TMP, PRIVATE_DEV)) { - r = bind_remount_recursive(m->path, false); - if (r == 0 && m->mode == PRIVATE_DEV) /* can be readonly but the submounts can't*/ - r = mount(NULL, m->path, NULL, MS_REMOUNT|DEV_MOUNT_OPTIONS|MS_RDONLY, NULL); - } else - r = 0; - - if (m->ignore && r == -ENOENT) - return 0; - - return r; -} - -int setup_namespace( - const char* root_directory, - char** read_write_dirs, - char** read_only_dirs, - char** inaccessible_dirs, - const char* tmp_dir, - const char* var_tmp_dir, - bool private_dev, - ProtectHome protect_home, - ProtectSystem protect_system, - unsigned long mount_flags) { - - BindMount *m, *mounts = NULL; - unsigned n; - int r = 0; - - if (mount_flags == 0) - mount_flags = MS_SHARED; - - if (unshare(CLONE_NEWNS) < 0) - return -errno; - - n = !!tmp_dir + !!var_tmp_dir + - strv_length(read_write_dirs) + - strv_length(read_only_dirs) + - strv_length(inaccessible_dirs) + - private_dev + - (protect_home != PROTECT_HOME_NO ? 3 : 0) + - (protect_system != PROTECT_SYSTEM_NO ? 2 : 0) + - (protect_system == PROTECT_SYSTEM_FULL ? 1 : 0); - - if (n > 0) { - m = mounts = (BindMount *) alloca0(n * sizeof(BindMount)); - r = append_mounts(&m, read_write_dirs, READWRITE); - if (r < 0) - return r; - - r = append_mounts(&m, read_only_dirs, READONLY); - if (r < 0) - return r; - - r = append_mounts(&m, inaccessible_dirs, INACCESSIBLE); - if (r < 0) - return r; - - if (tmp_dir) { - m->path = prefix_roota(root_directory, "/tmp"); - m->mode = PRIVATE_TMP; - m++; - } - - if (var_tmp_dir) { - m->path = prefix_roota(root_directory, "/var/tmp"); - m->mode = PRIVATE_VAR_TMP; - m++; - } - - if (private_dev) { - m->path = prefix_roota(root_directory, "/dev"); - m->mode = PRIVATE_DEV; - m++; - } - - if (protect_home != PROTECT_HOME_NO) { - const char *home_dir, *run_user_dir, *root_dir; - - home_dir = prefix_roota(root_directory, "/home"); - home_dir = strjoina("-", home_dir); - run_user_dir = prefix_roota(root_directory, "/run/user"); - run_user_dir = strjoina("-", run_user_dir); - root_dir = prefix_roota(root_directory, "/root"); - root_dir = strjoina("-", root_dir); - - r = append_mounts(&m, STRV_MAKE(home_dir, run_user_dir, root_dir), - protect_home == PROTECT_HOME_READ_ONLY ? READONLY : INACCESSIBLE); - if (r < 0) - return r; - } - - if (protect_system != PROTECT_SYSTEM_NO) { - const char *usr_dir, *boot_dir, *etc_dir; - - usr_dir = prefix_roota(root_directory, "/usr"); - boot_dir = prefix_roota(root_directory, "/boot"); - boot_dir = strjoina("-", boot_dir); - etc_dir = prefix_roota(root_directory, "/etc"); - - r = append_mounts(&m, protect_system == PROTECT_SYSTEM_FULL - ? STRV_MAKE(usr_dir, boot_dir, etc_dir) - : STRV_MAKE(usr_dir, boot_dir), READONLY); - if (r < 0) - return r; - } - - assert(mounts + n == m); - - qsort(mounts, n, sizeof(BindMount), mount_path_compare); - drop_duplicates(mounts, &n); - } - - if (n > 0 || root_directory) { - /* Remount / as SLAVE so that nothing now mounted in the namespace - shows up in the parent */ - if (mount(NULL, "/", NULL, MS_SLAVE|MS_REC, NULL) < 0) - return -errno; - } - - if (root_directory) { - /* Turn directory into bind mount */ - if (mount(root_directory, root_directory, NULL, MS_BIND|MS_REC, NULL) < 0) - return -errno; - } - - if (n > 0) { - for (m = mounts; m < mounts + n; ++m) { - r = apply_mount(m, tmp_dir, var_tmp_dir); - if (r < 0) - goto fail; - } - - for (m = mounts; m < mounts + n; ++m) { - r = make_read_only(m); - if (r < 0) - goto fail; - } - } - - if (root_directory) { - /* MS_MOVE does not work on MS_SHARED so the remount MS_SHARED will be done later */ - r = mount_move_root(root_directory); - - /* at this point, we cannot rollback */ - if (r < 0) - return r; - } - - /* Remount / as the desired mode. Not that this will not - * reestablish propagation from our side to the host, since - * what's disconnected is disconnected. */ - if (mount(NULL, "/", NULL, mount_flags | MS_REC, NULL) < 0) - /* at this point, we cannot rollback */ - return -errno; - - return 0; - -fail: - if (n > 0) { - for (m = mounts; m < mounts + n; ++m) - if (m->done) - (void) umount2(m->path, MNT_DETACH); - } - - return r; -} - -static int setup_one_tmp_dir(const char *id, const char *prefix, char **path) { - _cleanup_free_ char *x = NULL; - char bid[SD_ID128_STRING_MAX]; - sd_id128_t boot_id; - int r; - - assert(id); - assert(prefix); - assert(path); - - /* We include the boot id in the directory so that after a - * reboot we can easily identify obsolete directories. */ - - r = sd_id128_get_boot(&boot_id); - if (r < 0) - return r; - - x = strjoin(prefix, "/systemd-private-", sd_id128_to_string(boot_id, bid), "-", id, "-XXXXXX", NULL); - if (!x) - return -ENOMEM; - - RUN_WITH_UMASK(0077) - if (!mkdtemp(x)) - return -errno; - - RUN_WITH_UMASK(0000) { - char *y; - - y = strjoina(x, "/tmp"); - - if (mkdir(y, 0777 | S_ISVTX) < 0) - return -errno; - } - - *path = x; - x = NULL; - - return 0; -} - -int setup_tmp_dirs(const char *id, char **tmp_dir, char **var_tmp_dir) { - char *a, *b; - int r; - - assert(id); - assert(tmp_dir); - assert(var_tmp_dir); - - r = setup_one_tmp_dir(id, "/tmp", &a); - if (r < 0) - return r; - - r = setup_one_tmp_dir(id, "/var/tmp", &b); - if (r < 0) { - char *t; - - t = strjoina(a, "/tmp"); - rmdir(t); - rmdir(a); - - free(a); - return r; - } - - *tmp_dir = a; - *var_tmp_dir = b; - - return 0; -} - -int setup_netns(int netns_storage_socket[2]) { - _cleanup_close_ int netns = -1; - int r, q; - - assert(netns_storage_socket); - assert(netns_storage_socket[0] >= 0); - assert(netns_storage_socket[1] >= 0); - - /* We use the passed socketpair as a storage buffer for our - * namespace reference fd. Whatever process runs this first - * shall create a new namespace, all others should just join - * it. To serialize that we use a file lock on the socket - * pair. - * - * It's a bit crazy, but hey, works great! */ - - if (lockf(netns_storage_socket[0], F_LOCK, 0) < 0) - return -errno; - - netns = receive_one_fd(netns_storage_socket[0], MSG_DONTWAIT); - if (netns == -EAGAIN) { - /* Nothing stored yet, so let's create a new namespace */ - - if (unshare(CLONE_NEWNET) < 0) { - r = -errno; - goto fail; - } - - loopback_setup(); - - netns = open("/proc/self/ns/net", O_RDONLY|O_CLOEXEC|O_NOCTTY); - if (netns < 0) { - r = -errno; - goto fail; - } - - r = 1; - - } else if (netns < 0) { - r = netns; - goto fail; - - } else { - /* Yay, found something, so let's join the namespace */ - if (setns(netns, CLONE_NEWNET) < 0) { - r = -errno; - goto fail; - } - - r = 0; - } - - q = send_one_fd(netns_storage_socket[1], netns, MSG_DONTWAIT); - if (q < 0) { - r = q; - goto fail; - } - -fail: - lockf(netns_storage_socket[0], F_ULOCK, 0); - return r; -} - -static const char *const protect_home_table[_PROTECT_HOME_MAX] = { - [PROTECT_HOME_NO] = "no", - [PROTECT_HOME_YES] = "yes", - [PROTECT_HOME_READ_ONLY] = "read-only", -}; - -DEFINE_STRING_TABLE_LOOKUP(protect_home, ProtectHome); - -static const char *const protect_system_table[_PROTECT_SYSTEM_MAX] = { - [PROTECT_SYSTEM_NO] = "no", - [PROTECT_SYSTEM_YES] = "yes", - [PROTECT_SYSTEM_FULL] = "full", -}; - -DEFINE_STRING_TABLE_LOOKUP(protect_system, ProtectSystem); |