X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=src%2Fcore%2Fnamespace.c;h=5466b7baec2a8cdd96c40ab5619c49b6f8c98e74;hb=99dfe1345caeb2cd107f69111aba8a9db18a0e6f;hp=4cbb0a15657c90b95d7ee9660911e36ab83b837b;hpb=2b85f4e19cee6a8533208f9fd618a7da6d32ad51;p=elogind.git diff --git a/src/core/namespace.c b/src/core/namespace.c index 4cbb0a156..5466b7bae 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! */ @@ -68,6 +69,7 @@ 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; @@ -143,7 +145,7 @@ static int mount_dev(BindMount *m) { "/dev/tty\0"; char temporary_mount[] = "/tmp/namespace-dev-XXXXXX"; - const char *d, *dev = NULL, *devpts = NULL, *devshm = NULL, *devkdbus = NULL, *devhugepages = NULL, *devmqueue = NULL; + const char *d, *dev = NULL, *devpts = NULL, *devshm = NULL, *devkdbus = NULL, *devhugepages = NULL, *devmqueue = NULL, *devlog = NULL, *devptmx = NULL; _cleanup_umask_ mode_t u; int r; @@ -168,6 +170,9 @@ static int mount_dev(BindMount *m) { goto fail; } + devptmx = strappenda(temporary_mount, "/dev/ptmx"); + symlink("pts/ptmx", devptmx); + devshm = strappenda(temporary_mount, "/dev/shm"); mkdir(devshm, 01777); r = mount("/dev/shm", devshm, NULL, MS_BIND, NULL); @@ -188,6 +193,9 @@ static int mount_dev(BindMount *m) { mkdir(devhugepages, 0755); mount("/dev/hugepages", devhugepages, NULL, MS_BIND, NULL); + devlog = strappenda(temporary_mount, "/dev/log"); + symlink("/run/systemd/journal/dev-log", devlog); + NULSTR_FOREACH(d, devnodes) { _cleanup_free_ char *dn = NULL; struct stat st; @@ -217,7 +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; @@ -274,17 +285,21 @@ 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; @@ -294,6 +309,9 @@ static int apply_mount( what = var_tmp_dir; break; + case PRIVATE_DEV: + return mount_dev(m); + default: assert_not_reached("Unknown mode"); } @@ -304,7 +322,7 @@ 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; } @@ -314,14 +332,17 @@ 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( @@ -331,6 +352,8 @@ int setup_namespace( char* tmp_dir, char* var_tmp_dir, bool private_dev, + ProtectHome protect_home, + ProtectSystem protect_system, unsigned mount_flags) { BindMount *m, *mounts = NULL; @@ -347,10 +370,13 @@ int setup_namespace( strv_length(read_write_dirs) + strv_length(read_only_dirs) + strv_length(inaccessible_dirs) + - private_dev; + 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 *) alloca(n * sizeof(BindMount)); + m = mounts = (BindMount *) alloca0(n * sizeof(BindMount)); r = append_mounts(&m, read_write_dirs, READWRITE); if (r < 0) return r; @@ -381,30 +407,46 @@ int setup_namespace( m++; } + if (protect_home != PROTECT_HOME_NO) { + 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", "-/boot", "/etc") : STRV_MAKE("/usr", "-/boot"), READONLY); + if (r < 0) + return r; + } + assert(mounts + n == m); qsort(mounts, n, sizeof(BindMount), mount_path_compare); drop_duplicates(mounts, &n); } - /* 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 (n > 0) { + /* 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; - 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 = 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; + for (m = mounts; m < mounts + n; ++m) { + r = make_read_only(m); + if (r < 0) + goto fail; + } } - /* Remount / as the desired mode */ + /* 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) { r = -errno; goto fail; @@ -413,9 +455,11 @@ int setup_namespace( return 0; fail: - for (m = mounts; m < mounts + n; ++m) - if (m->done) - umount2(m->path, MNT_DETACH); + if (n > 0) { + for (m = mounts; m < mounts + n; ++m) + if (m->done) + umount2(m->path, MNT_DETACH); + } return r; } @@ -575,3 +619,19 @@ fail: 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);