merge udev/, libudev/, systemd/ files in src/; move extras/ to src/

1 files changed, 385 insertions, 0 deletions

diff --git a/src/udev-node.c b/src/udev-node.c
new file mode 100644
index 0000000000..31046bd713
--- /dev/null
+++ b/src/udev-node.c
@@ -0,0 +1,385 @@
+/*
+ * 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
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <errno.h>
+#include <grp.h>
+#include <dirent.h>
+#include <sys/time.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+
+#include "udev.h"
+
+#define TMP_FILE_EXT		".udev-tmp"
+
+static int node_symlink(struct udev *udev, const char *node, const char *slink)
+{
+	struct stat stats;
+	char target[UTIL_PATH_SIZE];
+	char *s;
+	size_t l;
+	char slink_tmp[UTIL_PATH_SIZE + sizeof(TMP_FILE_EXT)];
+	int i = 0;
+	int tail = 0;
+	int err = 0;
+
+	/* use relative link */
+	target[0] = '\0';
+	while (node[i] && (node[i] == slink[i])) {
+		if (node[i] == '/')
+			tail = i+1;
+		i++;
+	}
+	s = target;
+	l = sizeof(target);
+	while (slink[i] != '\0') {
+		if (slink[i] == '/')
+			l = util_strpcpy(&s, l, "../");
+		i++;
+	}
+	l = util_strscpy(s, l, &node[tail]);
+	if (l == 0) {
+		err = -EINVAL;
+		goto exit;
+	}
+
+	/* preserve link with correct target, do not replace node of other device */
+	if (lstat(slink, &stats) == 0) {
+		if (S_ISBLK(stats.st_mode) || S_ISCHR(stats.st_mode)) {
+			struct stat stats2;
+
+			info(udev, "found existing node instead of symlink '%s'\n", slink);
+			if (lstat(node, &stats2) == 0) {
+				if ((stats.st_mode & S_IFMT) == (stats2.st_mode & S_IFMT) &&
+				    stats.st_rdev == stats2.st_rdev && stats.st_ino != stats2.st_ino) {
+					info(udev, "replace device node '%s' with symlink to our node '%s'\n",
+					     slink, node);
+				} else {
+					err(udev, "device node '%s' already exists, "
+					    "link to '%s' will not overwrite it\n",
+					    slink, node);
+					goto exit;
+				}
+			}
+		} else if (S_ISLNK(stats.st_mode)) {
+			char buf[UTIL_PATH_SIZE];
+			int len;
+
+			dbg(udev, "found existing symlink '%s'\n", slink);
+			len = readlink(slink, buf, sizeof(buf));
+			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",
+					     slink, target);
+					udev_selinux_lsetfilecon(udev, slink, S_IFLNK);
+					utimensat(AT_FDCWD, slink, NULL, AT_SYMLINK_NOFOLLOW);
+					goto exit;
+				}
+			}
+		}
+	} else {
+		info(udev, "creating symlink '%s' to '%s'\n", slink, target);
+		do {
+			err = util_create_path_selinux(udev, slink);
+			if (err != 0 && err != -ENOENT)
+				break;
+			udev_selinux_setfscreatecon(udev, slink, S_IFLNK);
+			err = symlink(target, slink);
+			if (err != 0)
+				err = -errno;
+			udev_selinux_resetfscreatecon(udev);
+		} while (err == -ENOENT);
+		if (err == 0)
+			goto exit;
+	}
+
+	info(udev, "atomically replace '%s'\n", slink);
+	util_strscpyl(slink_tmp, sizeof(slink_tmp), slink, TMP_FILE_EXT, NULL);
+	unlink(slink_tmp);
+	do {
+		err = util_create_path_selinux(udev, slink_tmp);
+		if (err != 0 && err != -ENOENT)
+			break;
+		udev_selinux_setfscreatecon(udev, slink_tmp, S_IFLNK);
+		err = symlink(target, slink_tmp);
+		if (err != 0)
+			err = -errno;
+		udev_selinux_resetfscreatecon(udev);
+	} while (err == -ENOENT);
+	if (err != 0) {
+		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);
+		unlink(slink_tmp);
+	}
+exit:
+	return err;
+}
+
+/* find device node of device with highest priority */
+static const char *link_find_prioritized(struct udev_device *dev, bool add, const char *stackdir, char *buf, size_t bufsize)
+{
+	struct udev *udev = udev_device_get_udev(dev);
+	DIR *dir;
+	int priority = 0;
+	const char *target = NULL;
+
+	if (add) {
+		priority = udev_device_get_devlink_priority(dev);
+		util_strscpy(buf, bufsize, udev_device_get_devnode(dev));
+		target = buf;
+	}
+
+	dir = opendir(stackdir);
+	if (dir == NULL)
+		return target;
+	for (;;) {
+		struct udev_device *dev_db;
+		struct dirent *dent;
+
+		dent = readdir(dir);
+		if (dent == NULL || dent->d_name[0] == '\0')
+			break;
+		if (dent->d_name[0] == '.')
+			continue;
+
+		info(udev, "found '%s' claiming '%s'\n", dent->d_name, stackdir);
+
+		/* did we find ourself? */
+		if (strcmp(dent->d_name, udev_device_get_id_filename(dev)) == 0)
+			continue;
+
+		dev_db = udev_device_new_from_id_filename(udev, dent->d_name);
+		if (dev_db != NULL) {
+			const char *devnode;
+
+			devnode = udev_device_get_devnode(dev_db);
+			if (devnode != NULL) {
+				dbg(udev, "compare priority of '%s'(%i) > '%s'(%i)\n", target, priority,
+				    udev_device_get_devnode(dev_db), udev_device_get_devlink_priority(dev_db));
+				if (target == NULL || udev_device_get_devlink_priority(dev_db) > priority) {
+					info(udev, "'%s' claims priority %i for '%s'\n",
+					     udev_device_get_syspath(dev_db), udev_device_get_devlink_priority(dev_db), stackdir);
+					priority = udev_device_get_devlink_priority(dev_db);
+					util_strscpy(buf, bufsize, devnode);
+					target = buf;
+				}
+			}
+			udev_device_unref(dev_db);
+		}
+	}
+	closedir(dir);
+	return target;
+}
+
+/* manage "stack of names" with possibly specified device priorities */
+static void link_update(struct udev_device *dev, const char *slink, bool add)
+{
+	struct udev *udev = udev_device_get_udev(dev);
+	char name_enc[UTIL_PATH_SIZE];
+	char filename[UTIL_PATH_SIZE * 2];
+	char dirname[UTIL_PATH_SIZE];
+	const char *target;
+	char buf[UTIL_PATH_SIZE];
+
+	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));
+	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);
+		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);
+		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);
+	}
+
+	if (add) {
+		int err;
+
+		dbg(udev, "creating index: '%s'\n", filename);
+		do {
+			int fd;
+
+			err = util_create_path(udev, filename);
+			if (err != 0 && err != -ENOENT)
+				break;
+			fd = open(filename, O_WRONLY|O_CREAT|O_CLOEXEC|O_TRUNC|O_NOFOLLOW, 0444);
+			if (fd >= 0)
+				close(fd);
+			else
+				err = -errno;
+		} while (err == -ENOENT);
+	}
+}
+
+void udev_node_update_old_links(struct udev_device *dev, struct udev_device *dev_old)
+{
+	struct udev *udev = udev_device_get_udev(dev);
+	struct udev_list_entry *list_entry;
+
+	/* update possible left-over symlinks */
+	udev_list_entry_foreach(list_entry, udev_device_get_devlinks_list_entry(dev_old)) {
+		const char *name = udev_list_entry_get_name(list_entry);
+		struct udev_list_entry *list_entry_current;
+		int found;
+
+		/* check if old link name still belongs to this device */
+		found = 0;
+		udev_list_entry_foreach(list_entry_current, udev_device_get_devlinks_list_entry(dev)) {
+			const char *name_current = udev_list_entry_get_name(list_entry_current);
+
+			if (strcmp(name, name_current) == 0) {
+				found = 1;
+				break;
+			}
+		}
+		if (found)
+			continue;
+
+		info(udev, "update old name, '%s' no longer belonging to '%s'\n",
+		     name, udev_device_get_devpath(dev));
+		link_update(dev, name, 0);
+	}
+}
+
+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, "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);
+
+	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_num(list_entry))
+			/* simple unmanaged link name */
+			node_symlink(udev, udev_device_get_devnode(dev), udev_list_entry_get_name(list_entry));
+		else
+			link_update(dev, udev_list_entry_get_name(list_entry), 1);
+	}
+exit:
+	return err;
+}
+
+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;
+	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);
+
+	/* 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;
+}