diff options
Diffstat (limited to 'src/core/mount-setup.c')
| -rw-r--r-- | src/core/mount-setup.c | 281 |
1 files changed, 188 insertions, 93 deletions
diff --git a/src/core/mount-setup.c b/src/core/mount-setup.c index 16880e6157..3ce6164b06 100644 --- a/src/core/mount-setup.c +++ b/src/core/mount-setup.c @@ -11,7 +11,9 @@ #include "bus-util.h" #include "cgroup-util.h" #include "dev-setup.h" +#include "dirent-util.h" #include "efivars.h" +#include "fd-util.h" #include "fileio.h" #include "fs-util.h" #include "label.h" @@ -20,7 +22,7 @@ #include "missing.h" #include "mkdir.h" #include "mount-setup.h" -#include "mount-util.h" +#include "mountpoint-util.h" #include "path-util.h" #include "set.h" #include "smack-util.h" @@ -229,76 +231,105 @@ int mount_setup_early(void) { return mount_points_setup(N_EARLY_MOUNT, false); } -int mount_cgroup_controllers(char ***join_controllers) { +static const char *join_with(const char *controller) { + + static const char* const pairs[] = { + "cpu", "cpuacct", + "net_cls", "net_prio", + NULL + }; + + const char *const *x, *const *y; + + assert(controller); + + /* This will lookup which controller to mount another controller with. Input is a controller name, and output + * is the other controller name. The function works both ways: you can input one and get the other, and input + * the other to get the one. */ + + STRV_FOREACH_PAIR(x, y, pairs) { + if (streq(controller, *x)) + return *y; + if (streq(controller, *y)) + return *x; + } + + return NULL; +} + +static int symlink_controller(const char *target, const char *alias) { + const char *a; + int r; + + assert(target); + assert(alias); + + a = strjoina("/sys/fs/cgroup/", alias); + + r = symlink_idempotent(target, a, false); + if (r < 0) + return log_error_errno(r, "Failed to create symlink %s: %m", a); + +#ifdef SMACK_RUN_LABEL + const char *p; + + p = strjoina("/sys/fs/cgroup/", target); + + r = mac_smack_copy(a, p); + if (r < 0 && r != -EOPNOTSUPP) + return log_error_errno(r, "Failed to copy smack label from %s to %s: %m", p, a); +#endif + + return 0; +} + +int mount_cgroup_controllers(void) { _cleanup_set_free_free_ Set *controllers = NULL; - bool has_argument = !!join_controllers; int r; if (!cg_is_legacy_wanted()) return 0; /* Mount all available cgroup controllers that are built into the kernel. */ - - if (!has_argument) - /* The defaults: - * mount "cpu" + "cpuacct" together, and "net_cls" + "net_prio". - * - * We'd like to add "cpuset" to the mix, but "cpuset" doesn't really - * work for groups with no initialized attributes. - */ - join_controllers = (char**[]) { - STRV_MAKE("cpu", "cpuacct"), - STRV_MAKE("net_cls", "net_prio"), - NULL, - }; - r = cg_kernel_controllers(&controllers); if (r < 0) return log_error_errno(r, "Failed to enumerate cgroup controllers: %m"); for (;;) { _cleanup_free_ char *options = NULL, *controller = NULL, *where = NULL; + const char *other_controller; MountPoint p = { .what = "cgroup", .type = "cgroup", .flags = MS_NOSUID|MS_NOEXEC|MS_NODEV, .mode = MNT_IN_CONTAINER, }; - char ***k = NULL; controller = set_steal_first(controllers); if (!controller) break; - for (k = join_controllers; *k; k++) - if (strv_find(*k, controller)) - break; - - if (*k) { - char **i, **j; - - for (i = *k, j = *k; *i; i++) { - - if (!streq(*i, controller)) { - _cleanup_free_ char *t; - - t = set_remove(controllers, *i); - if (!t) { - if (has_argument) - free(*i); - continue; - } - } - - *(j++) = *i; + /* Check if we shall mount this together with another controller */ + other_controller = join_with(controller); + if (other_controller) { + _cleanup_free_ char *c = NULL; + + /* Check if the other controller is actually available in the kernel too */ + c = set_remove(controllers, other_controller); + if (c) { + + /* Join the two controllers into one string, and maintain a stable ordering */ + if (strcmp(controller, other_controller) < 0) + options = strjoin(controller, ",", other_controller); + else + options = strjoin(other_controller, ",", controller); + if (!options) + return log_oom(); } + } - *j = NULL; - - options = strv_join(*k, ","); - if (!options) - return log_oom(); - } else + /* The simple case, where there's only one controller to mount together */ + if (!options) options = TAKE_PTR(controller); where = strappend("/sys/fs/cgroup/", options); @@ -312,35 +343,14 @@ int mount_cgroup_controllers(char ***join_controllers) { if (r < 0) return r; - if (r > 0 && *k) { - char **i; - - for (i = *k; *i; i++) { - _cleanup_free_ char *t = NULL; - - t = strappend("/sys/fs/cgroup/", *i); - if (!t) - return log_oom(); - - r = symlink(options, t); - if (r >= 0) { -#ifdef SMACK_RUN_LABEL - _cleanup_free_ char *src; - src = strappend("/sys/fs/cgroup/", options); - if (!src) - return log_oom(); - r = mac_smack_copy(t, src); - if (r < 0 && r != -EOPNOTSUPP) - return log_error_errno(r, "Failed to copy smack label from %s to %s: %m", src, t); -#endif - } else if (errno != EEXIST) - return log_error_errno(errno, "Failed to create symlink %s: %m", t); - } - } + /* Create symlinks from the individual controller names, in case we have a joined mount */ + if (controller) + (void) symlink_controller(options, controller); + if (other_controller) + (void) symlink_controller(options, other_controller); } - /* Now that we mounted everything, let's make the tmpfs the - * cgroup file systems are mounted into read-only. */ + /* Now that we mounted everything, let's make the tmpfs the cgroup file systems are mounted into read-only. */ (void) mount("tmpfs", "/sys/fs/cgroup", "tmpfs", MS_REMOUNT|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_STRICTATIME|MS_RDONLY, "mode=755"); return 0; @@ -396,6 +406,100 @@ static int relabel_cgroup_filesystems(void) { return 0; } + +static int relabel_extra(void) { + _cleanup_closedir_ DIR *d = NULL; + int r, c = 0; + + /* Support for relabelling additional files or directories after loading the policy. For this, code in the + * initrd simply has to drop in *.relabel files into /run/systemd/relabel-extra.d/. We'll read all such files + * expecting one absolute path by line and will relabel each (and everyone below that in case the path refers + * to a directory). These drop-in files are supposed to be absolutely minimal, and do not understand comments + * and such. After the operation succeeded the files are removed, and the drop-in directory as well, if + * possible. + */ + + d = opendir("/run/systemd/relabel-extra.d/"); + if (!d) { + if (errno == ENOENT) + return 0; + + return log_warning_errno(errno, "Failed to open /run/systemd/relabel-extra.d/, ignoring: %m"); + } + + for (;;) { + _cleanup_fclose_ FILE *f = NULL; + _cleanup_close_ int fd = -1; + struct dirent *de; + + errno = 0; + de = readdir_no_dot(d); + if (!de) { + if (errno != 0) + return log_error_errno(errno, "Failed read directory /run/systemd/relabel-extra.d/, ignoring: %m"); + break; + } + + if (hidden_or_backup_file(de->d_name)) + continue; + + if (!endswith(de->d_name, ".relabel")) + continue; + + if (!IN_SET(de->d_type, DT_REG, DT_UNKNOWN)) + continue; + + fd = openat(dirfd(d), de->d_name, O_RDONLY|O_CLOEXEC|O_NONBLOCK); + if (fd < 0) { + log_warning_errno(errno, "Failed to open /run/systemd/relabel-extra.d/%s, ignoring: %m", de->d_name); + continue; + } + + f = fdopen(fd, "r"); + if (!f) { + log_warning_errno(errno, "Failed to convert file descriptor into file object, ignoring: %m"); + continue; + } + TAKE_FD(fd); + + for (;;) { + _cleanup_free_ char *line = NULL; + + r = read_line(f, LONG_LINE_MAX, &line); + if (r < 0) { + log_warning_errno(r, "Failed to read from /run/systemd/relabel-extra.d/%s, ignoring: %m", de->d_name); + break; + } + if (r == 0) /* EOF */ + break; + + path_simplify(line, true); + + if (!path_is_normalized(line)) { + log_warning("Path to relabel is not normalized, ignoring: %s", line); + continue; + } + + if (!path_is_absolute(line)) { + log_warning("Path to relabel is not absolute, ignoring: %s", line); + continue; + } + + log_debug("Relabelling additional file/directory '%s'.", line); + (void) nftw(line, nftw_cb, 64, FTW_MOUNT|FTW_PHYS|FTW_ACTIONRETVAL); + c++; + } + + if (unlinkat(dirfd(d), de->d_name, 0) < 0) + log_warning_errno(errno, "Failed to remove /run/systemd/relabel-extra.d/%s, ignoring: %m", de->d_name); + } + + /* Remove when we completing things. */ + if (rmdir("/run/systemd/relabel-extra.d") < 0) + log_warning_errno(errno, "Failed to remove /run/systemd/relabel-extra.d/ directory: %m"); + + return c; +} #endif int mount_setup(bool loaded_policy) { @@ -413,20 +517,22 @@ int mount_setup(bool loaded_policy) { if (loaded_policy) { usec_t before_relabel, after_relabel; char timespan[FORMAT_TIMESPAN_MAX]; + const char *i; + int n_extra; before_relabel = now(CLOCK_MONOTONIC); - (void) nftw("/dev", nftw_cb, 64, FTW_MOUNT|FTW_PHYS|FTW_ACTIONRETVAL); - (void) nftw("/dev/shm", nftw_cb, 64, FTW_MOUNT|FTW_PHYS|FTW_ACTIONRETVAL); - (void) nftw("/run", nftw_cb, 64, FTW_MOUNT|FTW_PHYS|FTW_ACTIONRETVAL); + FOREACH_STRING(i, "/dev", "/dev/shm", "/run") + (void) nftw(i, nftw_cb, 64, FTW_MOUNT|FTW_PHYS|FTW_ACTIONRETVAL); - r = relabel_cgroup_filesystems(); - if (r < 0) - return r; + (void) relabel_cgroup_filesystems(); + + n_extra = relabel_extra(); after_relabel = now(CLOCK_MONOTONIC); - log_info("Relabelled /dev, /run and /sys/fs/cgroup in %s.", + log_info("Relabelled /dev, /dev/shm, /run, /sys/fs/cgroup%s in %s.", + n_extra > 0 ? ", additional files" : "", format_timespan(timespan, sizeof(timespan), after_relabel - before_relabel, 0)); } #endif @@ -452,20 +558,9 @@ int mount_setup(bool loaded_policy) { (void) mkdir_label("/run/systemd", 0755); (void) mkdir_label("/run/systemd/system", 0755); - /* Set up inaccessible (and empty) file nodes of all types */ - (void) mkdir_label("/run/systemd/inaccessible", 0000); - (void) mknod("/run/systemd/inaccessible/reg", S_IFREG | 0000, 0); - (void) mkdir_label("/run/systemd/inaccessible/dir", 0000); - (void) mkfifo("/run/systemd/inaccessible/fifo", 0000); - (void) mknod("/run/systemd/inaccessible/sock", S_IFSOCK | 0000, 0); - - /* The following two are likely to fail if we lack the privs for it (for example in an userns environment, if - * CAP_SYS_MKNOD is missing, or if a device node policy prohibit major/minor of 0 device nodes to be - * created). But that's entirely fine. Consumers of these files should carry fallback to use a different node - * then, for example /run/systemd/inaccessible/sock, which is close enough in behaviour and semantics for most - * uses. */ - (void) mknod("/run/systemd/inaccessible/chr", S_IFCHR | 0000, makedev(0, 0)); - (void) mknod("/run/systemd/inaccessible/blk", S_IFBLK | 0000, makedev(0, 0)); + /* Also create /run/systemd/inaccessible nodes, so that we always have something to mount inaccessible nodes + * from. */ + (void) make_inaccessible_nodes(NULL, UID_INVALID, GID_INVALID); return 0; } |