X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=udev%2Fudev-node.c;h=31046bd71327bb39c044e422ca99c7fd63fef2a6;hp=c8113f10b094988b8769a3d6ce32b6d6d6a7c8e7;hb=220893b3cbdbf8932f95c44811b169a8f0d33939;hpb=326c5fc3ea684825629eccaf33a548759162a539

diff --git a/udev/udev-node.c b/udev/udev-node.c
index c8113f10b..31046bd71 100644
--- a/udev/udev-node.c
+++ b/udev/udev-node.c
@@ -33,88 +33,6 @@
 
 #define TMP_FILE_EXT		".udev-tmp"
 
-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 err = 0;
-
-
-	if (strcmp(udev_device_get_subsystem(dev), "block") == 0)
-		mode |= S_IFBLK;
-	else
-		mode |= S_IFCHR;
-
-	if (file == NULL)
-		file = udev_device_get_devnode(dev);
-
-	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);
-			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)];
-
-			info(udev, "atomically replace existing file '%s'\n", file);
-			util_strscpyl(file_tmp, sizeof(file_tmp), file, TMP_FILE_EXT, NULL);
-			unlink(file_tmp);
-			udev_selinux_setfscreatecon(udev, file_tmp, mode);
-			err = mknod(file_tmp, mode, devnum);
-			udev_selinux_resetfscreatecon(udev);
-			if (err != 0) {
-				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);
-				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' %u:%u %#o\n", file, major(devnum), minor(devnum), mode);
-		do {
-			err = util_create_path(udev, file);
-			if (err != 0 && err != -ENOENT)
-				break;
-			udev_selinux_setfscreatecon(udev, file, mode);
-			err = mknod(file, mode, devnum);
-			if (err != 0)
-				err = -errno;
-			udev_selinux_resetfscreatecon(udev);
-		} while (err == -ENOENT);
-		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;
-}
-
 static int node_symlink(struct udev *udev, const char *node, const char *slink)
 {
 	struct stat stats;
@@ -184,7 +102,7 @@ static int node_symlink(struct udev *udev, const char *node, const char *slink)
 	} else {
 		info(udev, "creating symlink '%s' to '%s'\n", slink, target);
 		do {
-			err = util_create_path(udev, slink);
+			err = util_create_path_selinux(udev, slink);
 			if (err != 0 && err != -ENOENT)
 				break;
 			udev_selinux_setfscreatecon(udev, slink, S_IFLNK);
@@ -201,7 +119,7 @@ static int node_symlink(struct udev *udev, const char *node, const char *slink)
 	util_strscpyl(slink_tmp, sizeof(slink_tmp), slink, TMP_FILE_EXT, NULL);
 	unlink(slink_tmp);
 	do {
-		err = util_create_path(udev, slink_tmp);
+		err = util_create_path_selinux(udev, slink_tmp);
 		if (err != 0 && err != -ENOENT)
 			break;
 		udev_selinux_setfscreatecon(udev, slink_tmp, S_IFLNK);
@@ -243,26 +161,20 @@ static const char *link_find_prioritized(struct udev_device *dev, bool add, cons
 	for (;;) {
 		struct udev_device *dev_db;
 		struct dirent *dent;
-		int maj, min;
-		char type, type2;
-		dev_t devnum;
 
 		dent = readdir(dir);
 		if (dent == NULL || dent->d_name[0] == '\0')
 			break;
 		if (dent->d_name[0] == '.')
 			continue;
-		if (sscanf(dent->d_name, "%c%i:%i", &type, &maj, &min) != 3)
-			continue;
-		info(udev, "found '%c%i:%i' claiming '%s'\n", type, maj, min, stackdir);
-		devnum = makedev(maj, min);
+
+		info(udev, "found '%s' claiming '%s'\n", dent->d_name, stackdir);
 
 		/* did we find ourself? */
-		type2 = strcmp(udev_device_get_subsystem(dev), "block") == 0 ? 'b' : 'c';
-		if (udev_device_get_devnum(dev) == devnum && type == type2)
+		if (strcmp(dent->d_name, udev_device_get_id_filename(dev)) == 0)
 			continue;
 
-		dev_db = udev_device_new_from_devnum(udev, type, devnum);
+		dev_db = udev_device_new_from_id_filename(udev, dent->d_name);
 		if (dev_db != NULL) {
 			const char *devnode;
 
@@ -298,10 +210,8 @@ 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_run_path(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);
@@ -329,7 +239,7 @@ 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|O_NOFOLLOW, 0444);
+			fd = open(filename, O_WRONLY|O_CREAT|O_CLOEXEC|O_TRUNC|O_NOFOLLOW, 0444);
 			if (fd >= 0)
 				close(fd);
 			else
@@ -368,25 +278,79 @@ void udev_node_update_old_links(struct udev_device *dev, struct udev_device *dev
 	}
 }
 
+static int node_fixup(struct udev_device *dev, mode_t mode, uid_t uid, gid_t gid)
+{
+	struct udev *udev = udev_device_get_udev(dev);
+	const char *devnode = udev_device_get_devnode(dev);
+	dev_t devnum = udev_device_get_devnum(dev);
+	struct stat stats;
+	int err = 0;
+
+	if (strcmp(udev_device_get_subsystem(dev), "block") == 0)
+		mode |= S_IFBLK;
+	else
+		mode |= S_IFCHR;
+
+	if (lstat(devnode, &stats) != 0) {
+		err = -errno;
+		info(udev, "can not stat() node '%s' (%m)\n", devnode);
+		goto out;
+	}
+
+	if (((stats.st_mode & S_IFMT) != (mode & S_IFMT)) || (stats.st_rdev != devnum)) {
+		err = -EEXIST;
+		info(udev, "found node '%s' with non-matching devnum %s, skip handling\n",
+		     udev_device_get_devnode(dev), udev_device_get_id_filename(dev));
+		goto out;
+	}
+
+	if ((stats.st_mode & 0777) != (mode & 0777) || stats.st_uid != uid || stats.st_gid != gid) {
+		info(udev, "set permissions %s, %#o, uid=%u, gid=%u\n", devnode, mode, uid, gid);
+		chmod(devnode, mode);
+		chown(devnode, uid, gid);
+	} else {
+		info(udev, "preserve permissions %s, %#o, uid=%u, gid=%u\n", devnode, 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, devnode, mode);
+
+	/* always update timestamp when we re-use the node, like on media change events */
+	utimensat(AT_FDCWD, devnode, NULL, 0);
+out:
+	return err;
+}
+
 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);
+	char filename[UTIL_PATH_SIZE];
 	struct udev_list_entry *list_entry;
 	int err = 0;
 
-	info(udev, "creating device node '%s', devnum=%d:%d, mode=%#o, uid=%d, gid=%d\n",
-	     udev_device_get_devnode(dev),
-	     major(udev_device_get_devnum(dev)), minor(udev_device_get_devnum(dev)),
-	     mode, uid, gid);
+	info(udev, "handling device node '%s', devnum=%s, mode=%#o, uid=%d, gid=%d\n",
+	     udev_device_get_devnode(dev), udev_device_get_id_filename(dev), mode, uid, gid);
 
-	if (udev_node_mknod(dev, NULL, mode, uid, gid) != 0) {
-		err = -1;
+	err = node_fixup(dev, mode, uid, gid);
+	if (err < 0)
 		goto exit;
-	}
+
+	/* always add /dev/{block,char}/$major:$minor */
+	snprintf(filename, sizeof(filename), "%s/%s/%u:%u",
+		 udev_get_dev_path(udev),
+		 strcmp(udev_device_get_subsystem(dev), "block") == 0 ? "block" : "char",
+		 major(udev_device_get_devnum(dev)), minor(udev_device_get_devnum(dev)));
+	node_symlink(udev, udev_device_get_devnode(dev), filename);
 
 	/* 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))
+		if (udev_list_entry_get_num(list_entry))
 			/* simple unmanaged link name */
 			node_symlink(udev, udev_device_get_devnode(dev), udev_list_entry_get_name(list_entry));
 		else
@@ -403,39 +367,19 @@ int udev_node_remove(struct udev_device *dev)
 	const char *devnode;
 	struct stat stats;
 	struct udev_device *dev_check;
+	char filename[UTIL_PATH_SIZE];
 	int err = 0;
 
 	/* remove/update symlinks, remove symlinks from name index */
 	udev_list_entry_foreach(list_entry, udev_device_get_devlinks_list_entry(dev))
 		link_update(dev, udev_list_entry_get_name(list_entry), 0);
 
-	devnode = udev_device_get_devnode(dev);
-	if (devnode == NULL)
-		goto out;
-
-	if (stat(devnode, &stats) != 0) {
-		info(udev, "device node '%s' not found\n", devnode);
-		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);
-		err = -1;
-		goto out;
-	}
-
-	dev_check = udev_device_new_from_syspath(udev, udev_device_get_syspath(dev));
-	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);
-		udev_device_unref(dev_check);
-		goto out;
-	}
-
-	info(udev, "removing device node '%s'\n", devnode);
-	err = util_unlink_secure(udev, devnode);
-	if (err == 0)
-		util_delete_path(udev, devnode);
+	/* remove /dev/{block,char}/$major:$minor */
+	snprintf(filename, sizeof(filename), "%s/%s/%u:%u",
+		 udev_get_dev_path(udev),
+		 strcmp(udev_device_get_subsystem(dev), "block") == 0 ? "block" : "char",
+		 major(udev_device_get_devnum(dev)), minor(udev_device_get_devnum(dev)));
+	unlink(filename);
 out:
 	return err;
 }