X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=src%2Fcore%2Fnamespace.c;h=f76d3891c387678cb4bac5f4b75a2588341b9d39;hb=671174136525ddf208cdbe75d6d6bd159afa961f;hp=080c086fd4a01e22e11e23fb8c5e333f43e16b5a;hpb=1b8689f94983b47bf190e77ddb03a8fc6af15fb3;p=elogind.git diff --git a/src/core/namespace.c b/src/core/namespace.c index 080c086fd..f76d3891c 100644 --- a/src/core/namespace.c +++ b/src/core/namespace.c @@ -42,6 +42,7 @@ #include "mkdir.h" #include "dev-setup.h" #include "def.h" +#include "label.h" typedef enum MountMode { /* This is ordered by priority! */ @@ -50,6 +51,7 @@ typedef enum MountMode { PRIVATE_TMP, PRIVATE_VAR_TMP, PRIVATE_DEV, + PRIVATE_BUS_ENDPOINT, READWRITE } MountMode; @@ -68,6 +70,7 @@ static int append_mounts(BindMount **p, char **strv, MountMode mode) { STRV_FOREACH(i, strv) { (*p)->ignore = false; + (*p)->done = false; if ((mode == INACCESSIBLE || mode == READONLY || mode == READWRITE) && (*i)[0] == '-') { (*p)->ignore = true; @@ -122,8 +125,7 @@ static void drop_duplicates(BindMount *m, unsigned *n) { if (previous && path_equal(f->path, previous->path)) continue; - t->path = f->path; - t->mode = f->mode; + *t = *f; previous = t; @@ -223,7 +225,10 @@ static int mount_dev(BindMount *m) { goto fail; } + label_context_set(d, st.st_mode); r = mknod(dn, st.st_mode, st.st_rdev); + label_context_clear(); + if (r < 0) { r = -errno; goto fail; @@ -268,6 +273,84 @@ fail: return r; } +static int mount_kdbus(BindMount *m) { + + char temporary_mount[] = "/tmp/kdbus-dev-XXXXXX"; + _cleanup_free_ char *basepath = NULL; + _cleanup_umask_ mode_t u; + char *busnode = NULL, *root; + struct stat st; + int r; + + assert(m); + + u = umask(0000); + + if (!mkdtemp(temporary_mount)) { + log_error("Failed create temp dir: %m"); + return -errno; + } + + root = strappenda(temporary_mount, "/kdbus"); + mkdir(root, 0755); + if (mount("tmpfs", root, "tmpfs", MS_NOSUID|MS_STRICTATIME, "mode=777") < 0) { + r = -errno; + goto fail; + } + + /* create a new /dev/null dev node copy so we have some fodder to + * bind-mount the custom endpoint over. */ + if (stat("/dev/null", &st) < 0) { + log_error("Failed to stat /dev/null: %m"); + r = -errno; + goto fail; + } + + busnode = strappenda(root, "/bus"); + if (mknod(busnode, (st.st_mode & ~07777) | 0600, st.st_rdev) < 0) { + log_error("mknod() for %s failed: %m", busnode); + r = -errno; + goto fail; + } + + r = mount(m->path, busnode, "bind", MS_BIND, NULL); + if (r < 0) { + log_error("bind mount of %s failed: %m", m->path); + r = -errno; + goto fail; + } + + basepath = dirname_malloc(m->path); + if (!basepath) { + r = -ENOMEM; + goto fail; + } + + if (mount(root, basepath, NULL, MS_MOVE, NULL) < 0) { + log_error("bind mount of %s failed: %m", basepath); + r = -errno; + goto fail; + } + + rmdir(temporary_mount); + return 0; + +fail: + if (busnode) { + umount(busnode); + unlink(busnode); + } + + if (root) { + umount(root); + rmdir(root); + } + + rmdir(temporary_mount); + + return r; +} + static int apply_mount( BindMount *m, const char *tmp_dir, @@ -280,17 +363,21 @@ static int apply_mount( switch (m->mode) { - case PRIVATE_DEV: - return mount_dev(m); - 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: - what = m->path; - break; + /* Nothing to mount here, we just later toggle the + * MS_RDONLY bit for the mount point */ + return 0; case PRIVATE_TMP: what = tmp_dir; @@ -300,6 +387,12 @@ static int apply_mount( what = var_tmp_dir; break; + case PRIVATE_DEV: + return mount_dev(m); + + case PRIVATE_BUS_ENDPOINT: + return mount_kdbus(m); + default: assert_not_reached("Unknown mode"); } @@ -310,7 +403,7 @@ static int apply_mount( if (r >= 0) log_debug("Successfully mounted %s to %s", what, m->path); else if (m->ignore && errno == ENOENT) - r = 0; + return 0; return r; } @@ -320,14 +413,17 @@ static int make_read_only(BindMount *m) { assert(m); - if (m->mode != INACCESSIBLE && m->mode != READONLY) - return 0; + 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); + else + r = 0; - r = mount(NULL, m->path, NULL, MS_BIND|MS_REMOUNT|MS_RDONLY|MS_REC, NULL); - if (r < 0 && !(m->ignore && errno == ENOENT)) - return -errno; + if (m->ignore && r == -ENOENT) + return 0; - return 0; + return r; } int setup_namespace( @@ -336,6 +432,7 @@ int setup_namespace( char** inaccessible_dirs, char* tmp_dir, char* var_tmp_dir, + char* bus_endpoint_path, bool private_dev, ProtectHome protect_home, ProtectSystem protect_system, @@ -351,17 +448,17 @@ int setup_namespace( if (unshare(CLONE_NEWNS) < 0) return -errno; - n = !!tmp_dir + !!var_tmp_dir + + n = !!tmp_dir + !!var_tmp_dir + !!bus_endpoint_path + strv_length(read_write_dirs) + strv_length(read_only_dirs) + strv_length(inaccessible_dirs) + private_dev + - (protect_home != PROTECT_HOME_NO ? 2 : 0) + + (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 *) alloca(n * sizeof(BindMount)); + m = mounts = (BindMount *) alloca0(n * sizeof(BindMount)); r = append_mounts(&m, read_write_dirs, READWRITE); if (r < 0) return r; @@ -392,14 +489,20 @@ int setup_namespace( m++; } + if (bus_endpoint_path) { + m->path = bus_endpoint_path; + m->mode = PRIVATE_BUS_ENDPOINT; + m++; + } + if (protect_home != PROTECT_HOME_NO) { - r = append_mounts(&m, STRV_MAKE("-/home", "-/run/user"), protect_home == PROTECT_HOME_READ_ONLY ? READONLY : INACCESSIBLE); + r = append_mounts(&m, STRV_MAKE("-/home", "-/run/user", "-/root"), protect_home == PROTECT_HOME_READ_ONLY ? READONLY : INACCESSIBLE); if (r < 0) return r; } if (protect_system != PROTECT_SYSTEM_NO) { - r = append_mounts(&m, protect_system == PROTECT_SYSTEM_FULL ? STRV_MAKE("/usr", "/etc", "-/boot") : STRV_MAKE("/usr", "-/boot"), READONLY); + r = append_mounts(&m, protect_system == PROTECT_SYSTEM_FULL ? STRV_MAKE("/usr", "-/boot", "/etc") : STRV_MAKE("/usr", "-/boot"), READONLY); if (r < 0) return r; }