[PATCH] use numeric owner/group as default values to avoid parsing userdb

[elogind.git] / udev_remove.c

diff --git a/udev_remove.c b/udev_remove.c
index 32cd785984c821267fde164258098ea07b0aa8b9..7a6c032d01cbbf39c638c3489dce0e6932a64af8 100644 (file)
--- a/udev_remove.c
+++ b/udev_remove.c
@@ -31,7 +31,7 @@
 #include <sys/stat.h>
 
 #include "udev.h"
-#include "udev_lib.h"
+#include "udev_utils.h"
 #include "udev_version.h"
 #include "namedev.h"
 #include "udev_db.h"
@@ -67,56 +67,30 @@ static int delete_path(const 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)
-{
-       int retval;
-
-       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));
-       }
-       return retval;
-}
-
 static int delete_node(struct udevice *udev)
 {
        char filename[NAME_SIZE];
        char partitionname[NAME_SIZE];
+       struct name_entry *name_loop;
+       struct stat stats;
        int retval;
        int i;
-       char *pos;
-       int len;
        int num;
 
        snprintf(filename, NAME_SIZE, "%s/%s", udev_root, udev->name);
        filename[NAME_SIZE-1] = '\0';
 
+       dbg("checking major/minor of device node '%s'", filename);
+       if (stat(filename, &stats) != 0)
+               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;
 
@@ -124,14 +98,14 @@ static int delete_node(struct udevice *udev)
        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, NAME_SIZE, "%s%d", filename, i);
+                       partitionname[NAME_SIZE-1] = '\0';
+                       unlink_secure(partitionname);
                }
        }
 
@@ -139,11 +113,8 @@ static int delete_node(struct udevice *udev)
        if (strchr(udev->name, '/'))
                delete_path(filename);
 
-       foreach_strpart(udev->symlink, " ", pos, len) {
-               char linkname[NAME_SIZE];
-
-               strfieldcpymax(linkname, pos, len+1);
-               snprintf(filename, NAME_SIZE, "%s/%s", udev_root, linkname);
+       list_for_each_entry(name_loop, &udev->symlink_list, node) {
+               snprintf(filename, NAME_SIZE, "%s/%s", udev_root, name_loop->name);
                filename[NAME_SIZE-1] = '\0';
 
                dbg("unlinking symlink '%s'", filename);
@@ -155,7 +126,7 @@ static int delete_node(struct udevice *udev)
                                filename, strerror(errno));
                        return retval;
                }
-               if (strchr(udev->symlink, '/')) {
+               if (strchr(filename, '/')) {
                        delete_path(filename);
                }
        }
@@ -170,13 +141,18 @@ static int delete_node(struct udevice *udev)
 int udev_remove_device(struct udevice *udev)
 {
        const char *temp;
-       int retval;
 
-       if (udev->type != 'b' && udev->type != 'c')
+       if (udev->type != BLOCK && udev->type != CLASS)
                return 0;
 
-       retval = udev_db_get_device(udev);
-       if (retval) {
+       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)
@@ -185,9 +161,6 @@ int udev_remove_device(struct udevice *udev)
                dbg("'%s' not found in database, falling back on default name", udev->name);
        }
 
-       dbg("remove name='%s'", udev->name);
-       udev_db_delete_device(udev);
-
        /* use full path to the environment */
        snprintf(udev->devname, NAME_SIZE, "%s/%s", udev_root, udev->name);