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=7ad7c2402a8e05f77d23a1451ab9b891372a8116;hb=7e720bd4ad8257d81d273d98294ebbcc03ade9ba;hpb=c850706e84e3a86484ca806f898f3c0672dae4cd

diff --git a/udev_remove.c b/udev_remove.c
index 7ad7c2402..3a3db737c 100644
--- a/udev_remove.c
+++ b/udev_remove.c
@@ -23,19 +23,21 @@
 
 #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;
@@ -65,77 +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;
+
+	snprintf(filename, NAME_SIZE, "%s/%s", udev_root, udev->name);
+	filename[NAME_SIZE-1] = '\0';
 
-	strfieldcpy(filename, udev_root);
-	strfieldcat(filename, dev->name);
+	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 partition nodes */
-	if (dev->partitions > 0) {
-		info("removing partitions '%s[1-%i]'", filename, dev->partitions);
-		for (i = 1; i <= dev->partitions; i++) {
+	/* remove all_partitions nodes */
+	num = udev->partitions;
+	if (num > 0) {
+		info("removing all_partitions '%s[1-%i]'", filename, num);
+		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);
@@ -146,7 +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);
 		}
 	}
@@ -155,36 +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);
 }