chiark / gitweb /
[PATCH] switch major/minor to dev_t
[elogind.git] / udev_remove.c
index d4be8bd..3a3db73 100644 (file)
 
 #include <stdlib.h>
 #include <string.h>
+#include <stddef.h>
 #include <stdio.h>
 #include <fcntl.h>
 #include <unistd.h>
 #include <errno.h>
+#include <sys/stat.h>
 
 #include "udev.h"
-#include "udev_lib.h"
+#include "udev_utils.h"
 #include "udev_version.h"
-#include "logging.h"
 #include "namedev.h"
-#include "udevdb.h"
+#include "udev_db.h"
+#include "logging.h"
 
-static int delete_path(char *path)
+static int delete_path(const char *path)
 {
        char *pos;
        int retval;
@@ -65,83 +67,59 @@ 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)
-{
-       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 *dev)
+static int delete_node(struct udevice *udev)
 {
        char filename[NAME_SIZE];
-       char linkname[NAME_SIZE];
        char partitionname[NAME_SIZE];
+       struct stat stats;
        int retval;
        int i;
        char *pos;
        int len;
        int num;
 
-       strfieldcpy(filename, udev_root);
-       strfieldcat(filename, dev->name);
+       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;
 
        /* 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);
+                       unlink_secure(partitionname);
                }
        }
 
        /* remove subdirectories */
-       if (strchr(dev->name, '/'))
+       if (strchr(udev->name, '/'))
                delete_path(filename);
 
-       foreach_strpart(dev->symlink, " ", pos, len) {
+       foreach_strpart(udev->symlink, " ", pos, len) {
+               char linkname[NAME_SIZE];
+
                strfieldcpymax(linkname, pos, len+1);
-               strfieldcpy(filename, udev_root);
-               strfieldcat(filename, linkname);
+               snprintf(filename, NAME_SIZE, "%s/%s", udev_root, linkname);
+               filename[NAME_SIZE-1] = '\0';
 
                dbg("unlinking symlink '%s'", filename);
                retval = unlink(filename);
@@ -152,7 +130,7 @@ static int delete_node(struct udevice *dev)
                                filename, strerror(errno));
                        return retval;
                }
-               if (strchr(dev->symlink, '/')) {
+               if (strchr(udev->symlink, '/')) {
                        delete_path(filename);
                }
        }
@@ -161,36 +139,37 @@ static int delete_node(struct udevice *dev)
 }
 
 /*
- * Look up the sysfs path in the database to see if we have named this device
- * something different from the kernel name.  If we have, us it.  If not, use
- * the default kernel name for lack of anything else to know to do.
+ * look up the sysfs path in the database to get the node name to remove
+ * If we can't find it, use kernel name for lack of anything else to know to do
  */
-int udev_remove_device(const char *path, const char *subsystem)
+int udev_remove_device(struct udevice *udev)
 {
-       struct udevice dev;
-       char *temp;
+       const char *temp;
        int retval;
 
-       memset(&dev, 0x00, sizeof(dev));
+       if (udev->type != 'b' && udev->type != 'c')
+               return 0;
 
-       retval = udevdb_get_dev(path, &dev);
-       if (retval != 0) {
-               dbg("'%s' not found in database, falling back on default name", path);
-               temp = strrchr(path, '/');
+       retval = udev_db_get_device(udev);
+       if (retval) {
+               /* fall back to kernel name */
+               temp = strrchr(udev->devpath, '/');
                if (temp == NULL)
                        return -ENODEV;
-               strfieldcpy(dev.name, &temp[1]);
+               strfieldcpy(udev->name, &temp[1]);
+               dbg("'%s' not found in database, falling back on default name", udev->name);
        }
-       dbg("name='%s'", dev.name);
 
-       dev.type = get_device_type(path, subsystem);
-       dev_d_send(&dev, subsystem, path);
-       udevdb_delete_dev(path);
+       if (udev->ignore_remove) {
+               dbg("remove event for '%s' requested to be ignored by rule", udev->name);
+               return 0;
+       }
 
-       if (dev.type == 'b' || dev.type == 'c')
-               retval = delete_node(&dev);
-       else if (dev.type == 'n')
-               retval = 0;
+       dbg("remove name='%s'", udev->name);
+       udev_db_delete_device(udev);
 
-       return retval;
+       /* use full path to the environment */
+       snprintf(udev->devname, NAME_SIZE, "%s/%s", udev_root, udev->name);
+
+       return delete_node(udev);
 }