more readlink buffer size handling

[elogind.git] / udev / udev-node.c

diff --git a/udev/udev-node.c b/udev/udev-node.c
index 3b4eb5f00bfb5ab18c53ca84ee059f3bd54be8f0..5c1b04b86c88bb150899c8c8e46d121379538c04 100644 (file)
--- a/udev/udev-node.c
+++ b/udev/udev-node.c
@@ -164,7 +164,7 @@ static int node_symlink(struct udev *udev, const char *node, const char *slink)
 
                        dbg(udev, "found existing symlink '%s'\n", slink);
                        len = readlink(slink, buf, sizeof(buf));
-                       if (len > 0) {
+                       if (len > 0 && len < (int)sizeof(buf)) {
                                buf[len] = '\0';
                                if (strcmp(target, buf) == 0) {
                                        info(udev, "preserve already existing symlink '%s' to '%s'\n",
@@ -323,7 +323,7 @@ static void link_update(struct udev_device *dev, const char *slink, bool add)
                        err = util_create_path(udev, filename);
                        if (err != 0 && err != -ENOENT)
                                break;
-                       fd = open(filename, O_WRONLY|O_CREAT, 0444);
+                       fd = open(filename, O_WRONLY|O_CREAT|O_NOFOLLOW, 0444);
                        if (fd >= 0)
                                close(fd);
                        else
@@ -365,8 +365,6 @@ void udev_node_update_old_links(struct udev_device *dev, struct udev_device *dev
 int udev_node_add(struct udev_device *dev, mode_t mode, uid_t uid, gid_t gid)
 {
        struct udev *udev = udev_device_get_udev(dev);
-       int i;
-       int num;
        struct udev_list_entry *list_entry;
        int err = 0;
 
@@ -380,23 +378,6 @@ int udev_node_add(struct udev_device *dev, mode_t mode, uid_t uid, gid_t gid)
                goto exit;
        }
 
-       /* create all_partitions if requested */
-       num = udev_device_get_num_fake_partitions(dev);
-       if (num > 0) {
-               info(udev, "creating device partition nodes '%s[1-%i]'\n", udev_device_get_devnode(dev), num);
-               for (i = 1; i <= num; i++) {
-                       char partitionname[UTIL_PATH_SIZE];
-                       dev_t part_devnum;
-
-                       snprintf(partitionname, sizeof(partitionname), "%s%d",
-                                udev_device_get_devnode(dev), i);
-                       partitionname[sizeof(partitionname)-1] = '\0';
-                       part_devnum = makedev(major(udev_device_get_devnum(dev)),
-                                           minor(udev_device_get_devnum(dev)) + i);
-                       udev_node_mknod(dev, partitionname, part_devnum, mode, uid, gid);
-               }
-       }
-
        /* create/update symlinks, add symlinks to name index */
        udev_list_entry_foreach(list_entry, udev_device_get_devlinks_list_entry(dev)) {
                if (udev_list_entry_get_flags(list_entry))
@@ -414,10 +395,10 @@ int udev_node_remove(struct udev_device *dev)
        struct udev *udev = udev_device_get_udev(dev);
        struct udev_list_entry *list_entry;
        const char *devnode;
-       char partitionname[UTIL_PATH_SIZE];
        struct stat stats;
+       struct udev_device *dev_check;
+       char filename[UTIL_PATH_SIZE];
        int err = 0;
-       int num;
 
        /* remove/update symlinks, remove symlinks from name index */
        udev_list_entry_foreach(list_entry, udev_device_get_devlinks_list_entry(dev))
@@ -425,46 +406,36 @@ int udev_node_remove(struct udev_device *dev)
 
        devnode = udev_device_get_devnode(dev);
        if (devnode == NULL)
-               return 0;
+               goto out;
+
        if (stat(devnode, &stats) != 0) {
                info(udev, "device node '%s' not found\n", devnode);
-               return 0;
+               goto out;
        }
+
        if (stats.st_rdev != udev_device_get_devnum(dev)) {
                info(udev, "device node '%s' points to a different device, skip removal\n", devnode);
-               return -1;
+               err = -1;
+               goto out;
        }
 
-       if (udev_device_get_ignore_remove(dev)) {
-               info(udev, "ignore_remove for '%s'\n", udev_device_get_devnode(dev));
-       } else {
-               struct udev_device *dev_check;
-
-               dev_check = udev_device_new_from_syspath(udev, udev_device_get_syspath(dev));
-               if (dev_check != NULL && stats.st_rdev == udev_device_get_devnum(dev_check)) {
-                       /* do not remove device node if the same sys-device is re-created in the meantime */
-                       info(udev, "keeping device node of existing device'%s'\n", devnode);
-               } else {
-                       info(udev, "removing device node '%s'\n", devnode);
-                       err = util_unlink_secure(udev, devnode);
-               }
+       dev_check = udev_device_new_from_syspath(udev, udev_device_get_syspath(dev));
+       if (dev_check != NULL) {
+               /* do not remove device node if the same sys-device is re-created in the meantime */
+               info(udev, "keeping device node of existing device'%s'\n", devnode);
                udev_device_unref(dev_check);
+               goto out;
        }
 
-       num = udev_device_get_num_fake_partitions(dev);
-       if (num > 0) {
-               int i;
-
-               info(udev, "removing all_partitions '%s[1-%i]'\n", devnode, num);
-               if (num > 255)
-                       return -1;
-               for (i = 1; i <= num; i++) {
-                       snprintf(partitionname, sizeof(partitionname), "%s%d", devnode, i);
-                       partitionname[sizeof(partitionname)-1] = '\0';
-                       util_unlink_secure(udev, partitionname);
-               }
+       util_strscpyl(filename, sizeof(filename), LIBEXECDIR "/devices", &devnode[strlen(udev_get_dev_path(udev))], NULL);
+       if (stat(filename, &stats) == 0 || stats.st_rdev == udev_device_get_devnum(dev)) {
+               info(udev, "static device entry found '%s', skip removal\n", devnode);
+               goto out;
        }
 
+       info(udev, "removing device node '%s'\n", devnode);
+       err = util_unlink_secure(udev, devnode);
        util_delete_path(udev, devnode);
+out:
        return err;
 }