X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Fcore%2Fnamespace.c;h=4b8dbdd0d83d975a2e5f135d280d05f056047f98;hp=43b9045800cb175a9b5dce74f52c0e10b89bad33;hb=4968105790c65af58d4ab42bffa2a4bedc0be8ee;hpb=c8835999c33c0443bf91e1a8fa6dd716a8ff0b0f

diff --git a/src/core/namespace.c b/src/core/namespace.c
index 43b904580..4b8dbdd0d 100644
--- a/src/core/namespace.c
+++ b/src/core/namespace.c
@@ -35,13 +35,15 @@
 #include "strv.h"
 #include "util.h"
 #include "path-util.h"
-#include "namespace.h"
 #include "missing.h"
 #include "execute.h"
 #include "loopback-setup.h"
 #include "mkdir.h"
 #include "dev-setup.h"
 #include "def.h"
+#include "label.h"
+#include "selinux-util.h"
+#include "namespace.h"
 
 typedef enum MountMode {
         /* This is ordered by priority! */
@@ -50,6 +52,7 @@ typedef enum MountMode {
         PRIVATE_TMP,
         PRIVATE_VAR_TMP,
         PRIVATE_DEV,
+        PRIVATE_BUS_ENDPOINT,
         READWRITE
 } MountMode;
 
@@ -68,6 +71,7 @@ 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 +126,7 @@ 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;
 
@@ -143,7 +146,7 @@ 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, *devlog = NULL, *devptmx = NULL;
+        const char *d, *dev = NULL, *devpts = NULL, *devshm = NULL, *devhugepages = NULL, *devmqueue = NULL, *devlog = NULL, *devptmx = NULL;
         _cleanup_umask_ mode_t u;
         int r;
 
@@ -155,14 +158,14 @@ static int mount_dev(BindMount *m) {
                 return -errno;
 
         dev = strappenda(temporary_mount, "/dev");
-        mkdir(dev, 0755);
+        (void)mkdir(dev, 0755);
         if (mount("tmpfs", dev, "tmpfs", MS_NOSUID|MS_STRICTATIME, "mode=755") < 0) {
                 r = -errno;
                 goto fail;
         }
 
         devpts = strappenda(temporary_mount, "/dev/pts");
-        mkdir(devpts, 0755);
+        (void)mkdir(devpts, 0755);
         if (mount("/dev/pts", devpts, NULL, MS_BIND, NULL) < 0) {
                 r = -errno;
                 goto fail;
@@ -172,7 +175,7 @@ static int mount_dev(BindMount *m) {
         symlink("pts/ptmx", devptmx);
 
         devshm = strappenda(temporary_mount, "/dev/shm");
-        mkdir(devshm, 01777);
+        (void)mkdir(devshm, 01777);
         r = mount("/dev/shm", devshm, NULL, MS_BIND, NULL);
         if (r < 0) {
                 r = -errno;
@@ -180,15 +183,11 @@ static int mount_dev(BindMount *m) {
         }
 
         devmqueue = strappenda(temporary_mount, "/dev/mqueue");
-        mkdir(devmqueue, 0755);
+        (void)mkdir(devmqueue, 0755);
         mount("/dev/mqueue", devmqueue, NULL, MS_BIND, NULL);
 
-        devkdbus = strappenda(temporary_mount, "/dev/kdbus");
-        mkdir(devkdbus, 0755);
-        mount("/dev/kdbus", devkdbus, NULL, MS_BIND, NULL);
-
         devhugepages = strappenda(temporary_mount, "/dev/hugepages");
-        mkdir(devhugepages, 0755);
+        (void)mkdir(devhugepages, 0755);
         mount("/dev/hugepages", devhugepages, NULL, MS_BIND, NULL);
 
         devlog = strappenda(temporary_mount, "/dev/log");
@@ -223,7 +222,10 @@ static int mount_dev(BindMount *m) {
                         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;
@@ -249,20 +251,87 @@ fail:
         if (devshm)
                 umount(devshm);
 
-        if (devkdbus)
-                umount(devkdbus);
-
         if (devhugepages)
                 umount(devhugepages);
 
         if (devmqueue)
                 umount(devmqueue);
 
-        if (dev) {
-                umount(dev);
-                rmdir(dev);
+        umount(dev);
+        rmdir(dev);
+        rmdir(temporary_mount);
+
+        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))
+                return log_error_errno(errno, "Failed create temp dir: %m");
+
+        root = strappenda(temporary_mount, "/kdbus");
+        (void)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_errno(errno, "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_errno(errno, "mknod() for %s failed: %m", busnode);
+                r = -errno;
+                goto fail;
+        }
+
+        r = mount(m->path, busnode, "bind", MS_BIND, NULL);
+        if (r < 0) {
+                log_error_errno(errno, "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_errno(errno, "bind mount of %s failed: %m", basepath);
+                r = -errno;
+                goto fail;
         }
 
+        rmdir(temporary_mount);
+        return 0;
+
+fail:
+        if (busnode) {
+                umount(busnode);
+                unlink(busnode);
+        }
+
+        umount(root);
+        rmdir(root);
         rmdir(temporary_mount);
 
         return r;
@@ -280,9 +349,6 @@ 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
@@ -295,8 +361,9 @@ static int apply_mount(
 
         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;
@@ -306,6 +373,12 @@ 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");
         }
@@ -316,7 +389,7 @@ 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;
 }
@@ -326,26 +399,30 @@ 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(
                 char** read_write_dirs,
                 char** read_only_dirs,
                 char** inaccessible_dirs,
-                char* tmp_dir,
-                char* var_tmp_dir,
+                const char* tmp_dir,
+                const char* var_tmp_dir,
+                const char* bus_endpoint_path,
                 bool private_dev,
                 ProtectHome protect_home,
                 ProtectSystem protect_system,
-                unsigned mount_flags) {
+                unsigned long mount_flags) {
 
         BindMount *m, *mounts = NULL;
         unsigned n;
@@ -357,17 +434,17 @@ 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 ? 3 : 0) +
-                (protect_system != PROTECT_SYSTEM_NO ? 1 : 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;
@@ -398,6 +475,12 @@ 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", "-/root"), protect_home == PROTECT_HOME_READ_ONLY ? READONLY : INACCESSIBLE);
                         if (r < 0)
@@ -405,7 +488,7 @@ int setup_namespace(
                 }
 
                 if (protect_system != PROTECT_SYSTEM_NO) {
-                        r = append_mounts(&m, protect_system == PROTECT_SYSTEM_FULL ? STRV_MAKE("/usr", "/etc") : STRV_MAKE("/usr"), 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;
                 }