chiark / gitweb /
create udevdb files only if somehting interesting happened
[elogind.git] / udev_remove.c
index d97a2411f4d7fe587d8a330e4b5a8e656be9f93e..b9a4384ee06e649b5f41cfaf94be96270e12c617 100644 (file)
 #include <fcntl.h>
 #include <unistd.h>
 #include <errno.h>
+#include <sys/stat.h>
 
+#include "udev_libc_wrapper.h"
 #include "udev.h"
-#include "udev_lib.h"
+#include "udev_utils.h"
 #include "udev_version.h"
+#include "udev_db.h"
 #include "logging.h"
-#include "namedev.h"
-#include "udevdb.h"
 
-static int delete_path(char *path)
+static int delete_path(const char *path)
 {
        char *pos;
        int retval;
@@ -66,98 +67,70 @@ static int delete_path(char *path)
        return 0;
 }
 
-/** Remove all permissions on the device node, before
-  * unlinking it. This fixes a security issue.
-  * If the user created a hard-link to the device node,
-  * he can't use it any longer, because he lost permission
-  * to do so.
-  */
-static int secure_unlink(const char *filename)
+static int delete_node(struct udevice *udev)
 {
+       char filename[PATH_SIZE];
+       char partitionname[PATH_SIZE];
+       struct name_entry *name_loop;
+       struct stat stats;
        int retval;
+       int i;
+       int num;
 
-       retval = chown(filename, 0, 0);
-       if (retval) {
-               dbg("chown(%s, 0, 0) failed with error '%s'",
-                   filename, strerror(errno));
-               /* We continue nevertheless.
-                * I think it's very unlikely for chown
-                * to fail here, if the file exists.
-                */
-       }
-       retval = chmod(filename, 0000);
-       if (retval) {
-               dbg("chmod(%s, 0000) failed with error '%s'",
-                   filename, strerror(errno));
-               /* We continue nevertheless. */
-       }
-       retval = unlink(filename);
-       if (errno == ENOENT)
-               retval = 0;
-       if (retval) {
-               dbg("unlink(%s) failed with error '%s'",
-                       filename, strerror(errno));
+       list_for_each_entry(name_loop, &udev->symlink_list, node) {
+               snprintf(filename, sizeof(filename), "%s/%s", udev_root, name_loop->name);
+               filename[sizeof(filename)-1] = '\0';
+
+               if (stat(filename, &stats) != 0) {
+                       dbg("symlink '%s' not found", filename);
+                       continue;
+               }
+               if (udev->devt && stats.st_rdev != udev->devt) {
+                       info("symlink '%s' points to a different device, skip removal", filename);
+                       continue;;
+               }
+
+               dbg("removing symlink '%s'", filename);
+               unlink(filename);
+
+               if (strchr(filename, '/'))
+                       delete_path(filename);
        }
-       return retval;
-}
 
-static int delete_node(struct udevice *dev)
-{
-       char filename[NAME_SIZE];
-       char linkname[NAME_SIZE];
-       char partitionname[NAME_SIZE];
-       int retval;
-       int i;
-       char *pos;
-       int len;
-       int num;
+       snprintf(filename, sizeof(filename), "%s/%s", udev_root, udev->name);
+       filename[sizeof(filename)-1] = '\0';
 
-       strfieldcpy(filename, udev_root);
-       strfieldcat(filename, dev->name);
+       if (stat(filename, &stats) != 0) {
+               dbg("device node '%s' not found", filename);
+               return -1;
+       }
+       if (udev->devt && stats.st_rdev != udev->devt) {
+               info("device node '%s' points to a different device, skip removal", filename);
+               return -1;
+       }
 
        info("removing device node '%s'", filename);
-       retval = secure_unlink(filename);
+       retval = unlink_secure(filename);
        if (retval)
                return retval;
 
-       /* remove all_partitions nodes */
-       num = dev->partitions;
+       num = udev->partitions;
        if (num > 0) {
                info("removing all_partitions '%s[1-%i]'", filename, num);
-               if (num > PARTITIONS_COUNT) {
+               if (num > 255) {
                        info("garbage from udev database, skip all_partitions removal");
                        return -1;
                }
                for (i = 1; i <= num; i++) {
-                       strfieldcpy(partitionname, filename);
-                       strintcat(partitionname, i);
-                       secure_unlink(partitionname);
+                       snprintf(partitionname, sizeof(partitionname), "%s%d", filename, i);
+                       partitionname[sizeof(partitionname)-1] = '\0';
+                       unlink_secure(partitionname);
                }
        }
 
-       /* remove subdirectories */
-       if (strchr(dev->name, '/'))
+       if (strchr(udev->name, '/'))
                delete_path(filename);
 
-       foreach_strpart(dev->symlink, " ", pos, len) {
-               strfieldcpymax(linkname, pos, len+1);
-               strfieldcpy(filename, udev_root);
-               strfieldcat(filename, linkname);
-
-               dbg("unlinking symlink '%s'", filename);
-               retval = unlink(filename);
-               if (errno == ENOENT)
-                       retval = 0;
-               if (retval) {
-                       dbg("unlink(%s) failed with error '%s'",
-                               filename, strerror(errno));
-                       return retval;
-               }
-               if (strchr(dev->symlink, '/')) {
-                       delete_path(filename);
-               }
-       }
-
        return retval;
 }
 
@@ -167,33 +140,23 @@ static int delete_node(struct udevice *dev)
  */
 int udev_remove_device(struct udevice *udev)
 {
-       struct udevice db_dev;
-       char *temp;
-       int retval;
-
-       memset(&db_dev, 0x00, sizeof(struct udevice));
+       if (udev->type != DEV_BLOCK && udev->type != DEV_CLASS)
+               return 0;
 
-       retval = udevdb_get_dev(udev->devpath, &db_dev);
-       if (retval == 0) {
-               /* get stored values in our device */
-               memcpy(udev, &db_dev, UDEVICE_DB_LEN);
+       if (udev_db_get_device(udev, udev->devpath) == 0) {
+               if (udev->ignore_remove) {
+                       dbg("remove event for '%s' requested to be ignored by rule", udev->name);
+                       return 0;
+               }
+               dbg("remove name='%s'", udev->name);
+               udev_db_delete_device(udev);
        } else {
-               /* fall back to kernel name */
-               temp = strrchr(udev->devpath, '/');
-               if (temp == NULL)
-                       return -ENODEV;
-               strfieldcpy(udev->name, &temp[1]);
-               dbg("'%s' not found in database, falling back on default name", udev->name);
+               dbg("'%s' not found in database, using kernel name '%s'", udev->devpath, udev->kernel_name);
+               strlcpy(udev->name, udev->kernel_name, sizeof(udev->name));
        }
-       dbg("remove name='%s'", udev->name);
-
-       dev_d_send(udev);
-       udevdb_delete_dev(udev->devpath);
+       /* use full path to the environment */
+       snprintf(udev->devname, sizeof(udev->devname), "%s/%s", udev_root, udev->name);
+       udev->devname[sizeof(udev->devname)-1] = '\0';
 
-       if (udev->type == 'b' || udev->type == 'c')
-               retval = delete_node(udev);
-       else
-               retval = 0;
-
-       return retval;
+       return delete_node(udev);
 }