X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Fmount-setup.c;h=290698939e1f876d43197b5f7e9f059bf3811517;hp=333107d0be6138f8b754b1e888da6b5c75ec3cc1;hb=0b3325e79eb98f2e5bc19a1b0efd99e693b31a99;hpb=122c1c819803fe742d9dac8088ac717469f3240c diff --git a/src/mount-setup.c b/src/mount-setup.c index 333107d0b..290698939 100644 --- a/src/mount-setup.c +++ b/src/mount-setup.c @@ -1,4 +1,4 @@ -/*-*- Mode: C; c-basic-offset: 8 -*-*/ +/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ /*** This file is part of systemd. @@ -26,11 +26,18 @@ #include #include #include +#include +#include #include "mount-setup.h" #include "log.h" #include "macro.h" #include "util.h" +#include "label.h" + +#ifndef TTY_GID +#define TTY_GID 5 +#endif typedef struct MountPoint { const char *what; @@ -42,13 +49,23 @@ typedef struct MountPoint { } MountPoint; static const MountPoint mount_table[] = { - { "proc", "/proc", "proc", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV, true }, - { "sysfs", "/sys", "sysfs", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV, true }, - { "devtmpfs", "/dev", "devtmpfs", "mode=755", MS_NOSUID, true }, - { "tmpfs", "/dev/shm", "tmpfs", "mode=1777", MS_NOSUID|MS_NOEXEC|MS_NODEV, true }, - { "devpts", "/dev/pts", "devpts", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV, false }, - { "tmpfs", "/cgroup", "tmpfs", "mode=755", MS_NOSUID|MS_NOEXEC|MS_NODEV, true }, - { "cgroup", "/cgroup/systemd", "cgroup", "none,name=systemd", MS_NOSUID|MS_NOEXEC|MS_NODEV, true }, + { "proc", "/proc", "proc", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV, true }, + { "sysfs", "/sys", "sysfs", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV, true }, + { "devtmpfs", "/dev", "devtmpfs", "mode=755", MS_NOSUID, true }, + { "tmpfs", "/dev/shm", "tmpfs", "mode=1777", MS_NOSUID|MS_NODEV, true }, + { "devpts", "/dev/pts", "devpts", "mode=620,gid=" STRINGIFY(TTY_GID), MS_NOSUID|MS_NOEXEC, false }, + { "tmpfs", "/run", "tmpfs", "mode=755", MS_NOSUID|MS_NODEV, true }, + { "tmpfs", "/sys/fs/cgroup", "tmpfs", "mode=755", MS_NOSUID|MS_NOEXEC|MS_NODEV, false }, + { "cgroup", "/sys/fs/cgroup/systemd", "cgroup", "none,name=systemd", MS_NOSUID|MS_NOEXEC|MS_NODEV, false }, +}; + +/* These are API file systems that might be mounted by other software, + * we just list them here so that we know that we should ignore them */ + +static const char * const ignore_paths[] = { + "/sys/fs/selinux", + "/selinux", + "/proc/bus/usb" }; bool mount_point_is_api(const char *path) { @@ -58,10 +75,20 @@ bool mount_point_is_api(const char *path) { * should be ignored */ for (i = 0; i < ELEMENTSOF(mount_table); i ++) - if (path_startswith(path, mount_table[i].where)) + if (path_equal(path, mount_table[i].where)) return true; - return path_startswith(path, "/cgroup/"); + return path_startswith(path, "/sys/fs/cgroup/"); +} + +bool mount_point_ignore(const char *path) { + unsigned i; + + for (i = 0; i < ELEMENTSOF(ignore_paths); i++) + if (path_equal(path, ignore_paths[i])) + return true; + + return false; } static int mount_one(const MountPoint *p) { @@ -69,6 +96,9 @@ static int mount_one(const MountPoint *p) { assert(p); + /* Relabel first, just in case */ + label_fix(p->where, true); + if ((r = path_is_mount_point(p->where)) < 0) return r; @@ -94,18 +124,23 @@ static int mount_one(const MountPoint *p) { return p->fatal ? -errno : 0; } + /* Relabel again, since we now mounted something fresh here */ + label_fix(p->where, false); + return 0; } static int mount_cgroup_controllers(void) { int r; FILE *f; - char buf [256]; + char buf[LINE_MAX]; /* Mount all available cgroup controllers that are built into the kernel. */ - if (!(f = fopen("/proc/cgroups", "re"))) - return -ENOENT; + if (!(f = fopen("/proc/cgroups", "re"))) { + log_error("Failed to enumerate cgroup controllers: %m"); + return 0; + } /* Ignore the header line */ (void) fgets(buf, sizeof(buf), f); @@ -113,8 +148,9 @@ static int mount_cgroup_controllers(void) { for (;;) { MountPoint p; char *controller, *where; + int enabled = false; - if (fscanf(f, "%ms %*i %*i %*i", &controller) != 1) { + if (fscanf(f, "%ms %*i %*i %i", &controller, &enabled) != 2) { if (feof(f)) break; @@ -124,7 +160,12 @@ static int mount_cgroup_controllers(void) { goto finish; } - if (asprintf(&where, "/cgroup/%s", controller) < 0) { + if (!enabled) { + free(controller); + continue; + } + + if (asprintf(&where, "/sys/fs/cgroup/%s", controller) < 0) { free(controller); r = -ENOMEM; goto finish; @@ -154,13 +195,83 @@ finish: return r; } -int mount_setup(void) { +static int symlink_and_label(const char *old_path, const char *new_path) { + int r; + + assert(old_path); + assert(new_path); + + if ((r = label_symlinkfile_set(new_path)) < 0) + return r; + + if (symlink(old_path, new_path) < 0) + r = -errno; + + label_file_clear(); + + return r; +} + +static int nftw_cb( + const char *fpath, + const struct stat *sb, + int tflag, + struct FTW *ftwbuf) { + + /* No need to label /dev twice in a row... */ + if (ftwbuf->level == 0) + return 0; + + label_fix(fpath, true); + return 0; +}; + +int mount_setup(bool loaded_policy) { + + const char symlinks[] = + "/proc/kcore\0" "/dev/core\0" + "/proc/self/fd\0" "/dev/fd\0" + "/proc/self/fd/0\0" "/dev/stdin\0" + "/proc/self/fd/1\0" "/dev/stdout\0" + "/proc/self/fd/2\0" "/dev/stderr\0"; + int r; unsigned i; + const char *j, *k; for (i = 0; i < ELEMENTSOF(mount_table); i ++) if ((r = mount_one(mount_table+i)) < 0) return r; + /* Nodes in devtmpfs and /run need to be manually updated for + * the appropriate labels, after mounting. The other virtual + * API file systems like /sys and /proc do not need that, they + * use the same label for all their files. */ + if (loaded_policy) { + usec_t before_relabel, after_relabel; + char timespan[FORMAT_TIMESPAN_MAX]; + + before_relabel = now(CLOCK_MONOTONIC); + + nftw("/dev", nftw_cb, 64, FTW_MOUNT|FTW_PHYS); + nftw("/run", nftw_cb, 64, FTW_MOUNT|FTW_PHYS); + + after_relabel = now(CLOCK_MONOTONIC); + + log_info("Relabelled /dev and /run in %s.", + format_timespan(timespan, sizeof(timespan), after_relabel - before_relabel)); + + } + + /* Create a few default symlinks, which are normally created + * by udevd, but some scripts might need them before we start + * udevd. */ + NULSTR_FOREACH_PAIR(j, k, symlinks) + symlink_and_label(j, k); + + /* Create a few directories we always want around */ + mkdir("/run/systemd", 0755); + mkdir("/run/systemd/system", 0755); + return mount_cgroup_controllers(); }