X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=udev_remove.c;h=3a3db737c186bd7763f92bd8399cdfc8305e0b22;hp=0dcec731ead0457745c49771b4a061448f5d64f4;hb=7e720bd4ad8257d81d273d98294ebbcc03ade9ba;hpb=5d24c6ca364c6232efa626049b03d02c15ab5e85

diff --git a/udev_remove.c b/udev_remove.c
index 0dcec731e..3a3db737c 100644
--- a/udev_remove.c
+++ b/udev_remove.c
@@ -28,13 +28,14 @@
 #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(const char *path)
 {
@@ -66,83 +67,59 @@ 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 *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);
@@ -153,7 +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);
 		}
 	}
@@ -167,18 +144,14 @@ static int delete_node(struct udevice *dev)
  */
 int udev_remove_device(struct udevice *udev)
 {
-	struct udevice db_dev;
 	const char *temp;
 	int retval;
 
 	if (udev->type != 'b' && udev->type != 'c')
 		return 0;
 
-	retval = udevdb_get_dev(udev->devpath, &db_dev);
-	if (retval == 0) {
-		/* copy over the stored values to our device */
-		memcpy(udev, &db_dev, UDEVICE_DB_LEN);
-	} else {
+	retval = udev_db_get_device(udev);
+	if (retval) {
 		/* fall back to kernel name */
 		temp = strrchr(udev->devpath, '/');
 		if (temp == NULL)
@@ -187,11 +160,16 @@ int udev_remove_device(struct udevice *udev)
 		dbg("'%s' not found in database, falling back on default name", udev->name);
 	}
 
+	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);
-	udevdb_delete_dev(udev->devpath);
+	udev_db_delete_device(udev);
 
 	/* use full path to the environment */
-	snprintf(udev->devname, NAME_SIZE-1, "%s%s", udev_root, udev->name);
+	snprintf(udev->devname, NAME_SIZE, "%s/%s", udev_root, udev->name);
 
 	return delete_node(udev);
 }