X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=udev%2Fudev-node.c;h=92634427f95ecceca96e9f27f4422164cf7b3a9c;hp=4314cceb79893d8f966ff8aa056ea8e7d265e766;hb=4281da1fa6fda10c15bee984825fc607a8385004;hpb=af24bb178eec6adcf4f04d3b183cd50a831c8b7e

diff --git a/udev/udev-node.c b/udev/udev-node.c
index 4314cceb7..92634427f 100644
--- a/udev/udev-node.c
+++ b/udev/udev-node.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2003-2009 Kay Sievers <kay.sievers@vrfy.org>
+ * Copyright (C) 2003-2010 Kay Sievers <kay.sievers@vrfy.org>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -33,15 +33,13 @@
 
 #define TMP_FILE_EXT		".udev-tmp"
 
-int udev_node_mknod(struct udev_device *dev, const char *file, dev_t devnum, mode_t mode, uid_t uid, gid_t gid)
+int udev_node_mknod(struct udev_device *dev, const char *file, mode_t mode, uid_t uid, gid_t gid)
 {
 	struct udev *udev = udev_device_get_udev(dev);
+	dev_t devnum = udev_device_get_devnum(dev);
 	struct stat stats;
-	int preserve = 0;
 	int err = 0;
 
-	if (major(devnum) == 0)
-		devnum = udev_device_get_devnum(dev);
 
 	if (strcmp(udev_device_get_subsystem(dev), "block") == 0)
 		mode |= S_IFBLK;
@@ -54,9 +52,22 @@ int udev_node_mknod(struct udev_device *dev, const char *file, dev_t devnum, mod
 	if (lstat(file, &stats) == 0) {
 		if (((stats.st_mode & S_IFMT) == (mode & S_IFMT)) && (stats.st_rdev == devnum)) {
 			info(udev, "preserve file '%s', because it has correct dev_t\n", file);
-			preserve = 1;
-			udev_selinux_lsetfilecon(udev, file, mode);
-			/* update time stamp when we re-use the node, like on media change events */
+			if (stats.st_mode != mode || stats.st_uid != uid || stats.st_gid != gid) {
+				info(udev, "set permissions %s, %#o, uid=%u, gid=%u\n", file, mode, uid, gid);
+				chmod(file, mode);
+				chown(file, uid, gid);
+			} else {
+				info(udev, "preserve permissions %s, %#o, uid=%u, gid=%u\n", file, mode, uid, gid);
+			}
+			/*
+			 * Set initial selinux file context only on add events.
+			 * We set the proper context on bootup (triger) or for newly
+			 * added devices, but we don't change it later, in case
+			 * something else has set a custom context in the meantime.
+			 */
+			if (strcmp(udev_device_get_action(dev), "add") == 0)
+				udev_selinux_lsetfilecon(udev, file, mode);
+			/* always update timestamp when we re-use the node, like on media change events */
 			utimensat(AT_FDCWD, file, NULL, 0);
 		} else {
 			char file_tmp[UTIL_PATH_SIZE + sizeof(TMP_FILE_EXT)];
@@ -68,18 +79,22 @@ int udev_node_mknod(struct udev_device *dev, const char *file, dev_t devnum, mod
 			err = mknod(file_tmp, mode, devnum);
 			udev_selinux_resetfscreatecon(udev);
 			if (err != 0) {
-				err(udev, "mknod(%s, %#o, %u, %u) failed: %m\n",
-				    file_tmp, mode, major(devnum), minor(devnum));
+				err(udev, "mknod '%s' %u:%u %#o failed: %m\n",
+				    file_tmp, major(devnum), minor(devnum), mode);
 				goto exit;
 			}
 			err = rename(file_tmp, file);
 			if (err != 0) {
-				err(udev, "rename(%s, %s) failed: %m\n", file_tmp, file);
+				err(udev, "rename '%s' '%s' failed: %m\n", file_tmp, file);
 				unlink(file_tmp);
+				goto exit;
 			}
+			info(udev, "set permissions '%s' %#o uid=%u gid=%u\n", file, mode, uid, gid);
+			chmod(file, mode);
+			chown(file, uid, gid);
 		}
 	} else {
-		info(udev, "mknod(%s, %#o, (%u,%u))\n", file, mode, major(devnum), minor(devnum));
+		info(udev, "mknod '%s' %u:%u %#o\n", file, major(devnum), minor(devnum), mode);
 		do {
 			err = util_create_path(udev, file);
 			if (err != 0 && err != -ENOENT)
@@ -90,28 +105,11 @@ int udev_node_mknod(struct udev_device *dev, const char *file, dev_t devnum, mod
 				err = -errno;
 			udev_selinux_resetfscreatecon(udev);
 		} while (err == -ENOENT);
-		if (err != 0) {
-			err(udev, "mknod(%s, %#o, (%u,%u) failed: %m\n", file, mode, major(devnum), minor(devnum));
-			goto exit;
-		}
-	}
-
-	if (!preserve || stats.st_mode != mode) {
-		info(udev, "chmod(%s, %#o)\n", file, mode);
-		err = chmod(file, mode);
-		if (err != 0) {
-			err(udev, "chmod(%s, %#o) failed: %m\n", file, mode);
-			goto exit;
-		}
-	}
-
-	if (!preserve || stats.st_uid != uid || stats.st_gid != gid) {
-		info(udev, "chown(%s, %u, %u)\n", file, uid, gid);
-		err = chown(file, uid, gid);
-		if (err != 0) {
-			err(udev, "chown(%s, %u, %u) failed: %m\n", file, uid, gid);
-			goto exit;
-		}
+		if (err != 0)
+			err(udev, "mknod '%s' %u:%u %#o' failed: %m\n", file, major(devnum), minor(devnum), mode);
+		info(udev, "set permissions '%s' %#o uid=%u gid=%u\n", file, mode, uid, gid);
+		chmod(file, mode);
+		chown(file, uid, gid);
 	}
 exit:
 	return err;
@@ -172,7 +170,7 @@ static int node_symlink(struct udev *udev, const char *node, const char *slink)
 
 			dbg(udev, "found existing symlink '%s'\n", slink);
 			len = readlink(slink, buf, sizeof(buf));
-			if (len > 0) {
+			if (len > 0 && len < (int)sizeof(buf)) {
 				buf[len] = '\0';
 				if (strcmp(target, buf) == 0) {
 					info(udev, "preserve already existing symlink '%s' to '%s'\n",
@@ -213,12 +211,12 @@ static int node_symlink(struct udev *udev, const char *node, const char *slink)
 		udev_selinux_resetfscreatecon(udev);
 	} while (err == -ENOENT);
 	if (err != 0) {
-		err(udev, "symlink(%s, %s) failed: %m\n", target, slink_tmp);
+		err(udev, "symlink '%s' '%s' failed: %m\n", target, slink_tmp);
 		goto exit;
 	}
 	err = rename(slink_tmp, slink);
 	if (err != 0) {
-		err(udev, "rename(%s, %s) failed: %m\n", slink_tmp, slink);
+		err(udev, "rename '%s' '%s' failed: %m\n", slink_tmp, slink);
 		unlink(slink_tmp);
 	}
 exit:
@@ -300,22 +298,20 @@ static void link_update(struct udev_device *dev, const char *slink, bool add)
 	dbg(udev, "update symlink '%s' of '%s'\n", slink, udev_device_get_syspath(dev));
 
 	util_path_encode(&slink[strlen(udev_get_dev_path(udev))+1], name_enc, sizeof(name_enc));
-	snprintf(dirname, sizeof(dirname), "%s/.udev/links/%s", udev_get_dev_path(udev), name_enc);
-	snprintf(filename, sizeof(filename), "%s/%c%u:%u", dirname,
-		 strcmp(udev_device_get_subsystem(dev), "block") == 0 ? 'b' : 'c',
-		 major(udev_device_get_devnum(dev)), minor(udev_device_get_devnum(dev)));
+	util_strscpyl(dirname, sizeof(dirname), udev_get_dev_path(udev), "/.udev/links/", name_enc, NULL);
+	util_strscpyl(filename, sizeof(filename), dirname, "/", udev_device_get_id_filename(dev), NULL);
 
 	if (!add) {
 		dbg(udev, "removing index: '%s'\n", filename);
-		unlink(filename);
-		util_delete_path(udev, filename);
+		if (unlink(filename) == 0)
+			rmdir(dirname);
 	}
 
 	target = link_find_prioritized(dev, add, dirname, buf, sizeof(buf));
 	if (target == NULL) {
 		info(udev, "no reference left, remove '%s'\n", slink);
-		unlink(slink);
-		util_delete_path(udev, slink);
+		if (unlink(slink) == 0)
+			util_delete_path(udev, slink);
 	} else {
 		info(udev, "creating link '%s' to '%s'\n", slink, target);
 		node_symlink(udev, target, slink);
@@ -331,7 +327,7 @@ static void link_update(struct udev_device *dev, const char *slink, bool add)
 			err = util_create_path(udev, filename);
 			if (err != 0 && err != -ENOENT)
 				break;
-			fd = open(filename, O_WRONLY|O_CREAT, 0444);
+			fd = open(filename, O_WRONLY|O_CREAT|O_NOFOLLOW, 0444);
 			if (fd >= 0)
 				close(fd);
 			else
@@ -373,8 +369,6 @@ void udev_node_update_old_links(struct udev_device *dev, struct udev_device *dev
 int udev_node_add(struct udev_device *dev, mode_t mode, uid_t uid, gid_t gid)
 {
 	struct udev *udev = udev_device_get_udev(dev);
-	int i;
-	int num;
 	struct udev_list_entry *list_entry;
 	int err = 0;
 
@@ -383,28 +377,11 @@ int udev_node_add(struct udev_device *dev, mode_t mode, uid_t uid, gid_t gid)
 	     major(udev_device_get_devnum(dev)), minor(udev_device_get_devnum(dev)),
 	     mode, uid, gid);
 
-	if (udev_node_mknod(dev, NULL, makedev(0,0), mode, uid, gid) != 0) {
+	if (udev_node_mknod(dev, NULL, mode, uid, gid) != 0) {
 		err = -1;
 		goto exit;
 	}
 
-	/* create all_partitions if requested */
-	num = udev_device_get_num_fake_partitions(dev);
-	if (num > 0) {
-		info(udev, "creating device partition nodes '%s[1-%i]'\n", udev_device_get_devnode(dev), num);
-		for (i = 1; i <= num; i++) {
-			char partitionname[UTIL_PATH_SIZE];
-			dev_t part_devnum;
-
-			snprintf(partitionname, sizeof(partitionname), "%s%d",
-				 udev_device_get_devnode(dev), i);
-			partitionname[sizeof(partitionname)-1] = '\0';
-			part_devnum = makedev(major(udev_device_get_devnum(dev)),
-					    minor(udev_device_get_devnum(dev)) + i);
-			udev_node_mknod(dev, partitionname, part_devnum, mode, uid, gid);
-		}
-	}
-
 	/* create/update symlinks, add symlinks to name index */
 	udev_list_entry_foreach(list_entry, udev_device_get_devlinks_list_entry(dev)) {
 		if (udev_list_entry_get_flags(list_entry))
@@ -422,11 +399,9 @@ int udev_node_remove(struct udev_device *dev)
 	struct udev *udev = udev_device_get_udev(dev);
 	struct udev_list_entry *list_entry;
 	const char *devnode;
-	char partitionname[UTIL_PATH_SIZE];
 	struct stat stats;
 	struct udev_device *dev_check;
 	int err = 0;
-	int num;
 
 	/* remove/update symlinks, remove symlinks from name index */
 	udev_list_entry_foreach(list_entry, udev_device_get_devlinks_list_entry(dev))
@@ -434,39 +409,31 @@ int udev_node_remove(struct udev_device *dev)
 
 	devnode = udev_device_get_devnode(dev);
 	if (devnode == NULL)
-		return 0;
+		goto out;
+
 	if (stat(devnode, &stats) != 0) {
 		info(udev, "device node '%s' not found\n", devnode);
-		return 0;
+		goto out;
 	}
+
 	if (stats.st_rdev != udev_device_get_devnum(dev)) {
 		info(udev, "device node '%s' points to a different device, skip removal\n", devnode);
-		return -1;
+		err = -1;
+		goto out;
 	}
 
 	dev_check = udev_device_new_from_syspath(udev, udev_device_get_syspath(dev));
-	if (dev_check != NULL && stats.st_rdev == udev_device_get_devnum(dev_check)) {
+	if (dev_check != NULL) {
 		/* do not remove device node if the same sys-device is re-created in the meantime */
 		info(udev, "keeping device node of existing device'%s'\n", devnode);
-	} else {
-		info(udev, "removing device node '%s'\n", devnode);
-		err = util_unlink_secure(udev, devnode);
+		udev_device_unref(dev_check);
+		goto out;
 	}
-	udev_device_unref(dev_check);
-
-	num = udev_device_get_num_fake_partitions(dev);
-	if (num > 0) {
-		int i;
-
-		info(udev, "removing all_partitions '%s[1-%i]'\n", devnode, num);
-		if (num > 255)
-			return -1;
-		for (i = 1; i <= num; i++) {
-			snprintf(partitionname, sizeof(partitionname), "%s%d", devnode, i);
-			partitionname[sizeof(partitionname)-1] = '\0';
-			util_unlink_secure(udev, partitionname);
-		}
-	}
-	util_delete_path(udev, devnode);
+
+	info(udev, "removing device node '%s'\n", devnode);
+	err = util_unlink_secure(udev, devnode);
+	if (err == 0)
+		util_delete_path(udev, devnode);
+out:
 	return err;
 }