[PATCH] Make udev/udevstart be one binary

[elogind.git] / udev-remove.c

diff --git a/udev-remove.c b/udev-remove.c
index 195b9874111b2269e0746082984810bb32722ab1..7ad7c2402a8e05f77d23a1451ab9b891372a8116 100644 (file)
--- a/udev-remove.c
+++ b/udev-remove.c
@@ -29,8 +29,8 @@
 #include <errno.h>
 
 #include "udev.h"
+#include "udev_lib.h"
 #include "udev_version.h"
-#include "udev_dbus.h"
 #include "logging.h"
 #include "namedev.h"
 #include "udevdb.h"
@@ -65,6 +65,41 @@ 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)
 {
        char filename[NAME_SIZE];
@@ -79,14 +114,9 @@ static int delete_node(struct udevice *dev)
        strfieldcat(filename, dev->name);
 
        info("removing device node '%s'", filename);
-       retval = unlink(filename);
-       if (errno == ENOENT)
-               retval = 0;
-       if (retval) {
-               dbg("unlink(%s) failed with error '%s'",
-                       filename, strerror(errno));
+       retval = secure_unlink(filename);
+       if (retval)
                return retval;
-       }
 
        /* remove partition nodes */
        if (dev->partitions > 0) {
@@ -94,7 +124,7 @@ static int delete_node(struct udevice *dev)
                for (i = 1; i <= dev->partitions; i++) {
                        strfieldcpy(partitionname, filename);
                        strintcat(partitionname, i);
-                       unlink(partitionname);
+                       secure_unlink(partitionname);
                }
        }
 
@@ -103,7 +133,7 @@ static int delete_node(struct udevice *dev)
                delete_path(filename);
 
        foreach_strpart(dev->symlink, " ", pos, len) {
-               strnfieldcpy(linkname, pos, len+1);
+               strfieldcpymax(linkname, pos, len+1);
                strfieldcpy(filename, udev_root);
                strfieldcat(filename, linkname);
 
@@ -129,28 +159,32 @@ static int delete_node(struct udevice *dev)
  * 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.
  */
-int udev_remove_device(char *path, char *subsystem)
+int udev_remove_device(const char *path, const char *subsystem)
 {
        struct udevice dev;
        char *temp;
        int retval;
 
-       memset(&dev, 0, sizeof(dev));
+       memset(&dev, 0x00, sizeof(dev));
 
        retval = udevdb_get_dev(path, &dev);
-       if (retval) {
+       if (retval != 0) {
                dbg("'%s' not found in database, falling back on default name", path);
                temp = strrchr(path, '/');
                if (temp == NULL)
                        return -ENODEV;
                strfieldcpy(dev.name, &temp[1]);
        }
+       dbg("name='%s'", dev.name);
 
-       dbg("name is '%s'", dev.name);
+       dev.type = get_device_type(path, subsystem);
+       dev_d_send(&dev, subsystem, path);
        udevdb_delete_dev(path);
 
-       sysbus_send_remove(dev.name, path);
+       if (dev.type == 'b' || dev.type == 'c')
+               retval = delete_node(&dev);
+       else if (dev.type == 'n')
+               retval = 0;
 
-       retval = delete_node(&dev);
        return retval;
 }