X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=udev_db.c;h=13d96894afdd6c9b7cd4effe679285f8f0d1f1b5;hb=fc6da921ad3bcb251aa317376e81701700e925c9;hp=e2b7b4d9214e6a40b53f27eca451b41e71e56ea0;hpb=fc55cf68ca0c0db5172a9de7e827c6c3f7c2a308;p=elogind.git

diff --git a/udev_db.c b/udev_db.c
index e2b7b4d92..13d96894a 100644
--- a/udev_db.c
+++ b/udev_db.c
@@ -1,6 +1,4 @@
 /*
- * udev_db.c
- *
  * Copyright (C) 2003 Greg Kroah-Hartman <greg@kroah.com>
  * Copyright (C) 2004-2005 Kay Sievers <kay.sievers@vrfy.org>
  *
@@ -15,7 +13,7 @@
  * 
  *	You should have received a copy of the GNU General Public License along
  *	with this program; if not, write to the Free Software Foundation, Inc.,
- *	675 Mass Ave, Cambridge, MA 02139, USA.
+ *	51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  *
  */
 
@@ -29,111 +27,149 @@
 #include <string.h>
 #include <errno.h>
 #include <dirent.h>
+#include <sys/stat.h>
+#include <sys/types.h>
 
-#include "libsysfs/sysfs/libsysfs.h"
-#include "udev_libc_wrapper.h"
 #include "udev.h"
-#include "udev_utils.h"
-#include "logging.h"
 
 
-static int devpath_to_db_path(const char *devpath, char *filename, size_t len)
+static size_t devpath_to_db_path(const char *devpath, char *filename, size_t len)
 {
-	size_t start, end, i;
+	size_t start;
 
 	/* add location of db files */
 	strlcpy(filename, udev_root, len);
-	strlcat(filename, "/", len);
-	start = strlcat(filename, DB_DIR, len);
-	end = strlcat(filename, devpath, len);
-	if (end > len)
-		end = len;
-
-	/* replace '/' to transform path into a filename */
-	for (i = start+1; i < end; i++)
-		if (filename[i] == '/')
-			filename[i] = PATH_TO_NAME_CHAR;
-
-	return 0;
+	start = strlcat(filename, "/"DB_DIR"/", len);
+	strlcat(filename, devpath, len);
+	return path_encode(&filename[start], len - start);
 }
 
-static int db_file_to_devpath(const char *filename, char *devpath, size_t len)
+/* reverse mapping from the device file name to the devpath */
+static int name_index(const char *devpath, const char *name, int add)
 {
-	size_t end, i;
-
-	strlcpy(devpath, "/", len);
-	end = strlcat(devpath, filename, len);
-
-	/* replace PATH_TO_NAME_CHAR to transform name into devpath */
-	for (i = 1; i < end; i++)
-		if (devpath[i] == PATH_TO_NAME_CHAR)
-			devpath[i] = '/';
-
+	char device[PATH_SIZE];
+	char filename[PATH_SIZE * 2];
+	size_t start;
+	int fd;
+
+	/* directory with device name */
+	strlcpy(filename, udev_root, sizeof(filename));
+	start = strlcat(filename, "/"DB_NAME_INDEX_DIR"/", sizeof(filename));
+	strlcat(filename, name, sizeof(filename));
+	path_encode(&filename[start], sizeof(filename) - start);
+	/* entry with the devpath */
+	strlcpy(device, devpath, sizeof(device));
+	path_encode(device, sizeof(device));
+	strlcat(filename, "/", sizeof(filename));
+	strlcat(filename, device, sizeof(filename));
+
+	if (add) {
+		dbg("creating: '%s'", filename);
+		create_path(filename);
+		fd = open(filename, O_WRONLY|O_TRUNC|O_CREAT, 0644);
+		if (fd > 0)
+			close(fd);
+	} else {
+		dbg("removing: '%s'", filename);
+		unlink(filename);
+		delete_path(filename);
+	}
 	return 0;
 }
 
 int udev_db_add_device(struct udevice *udev)
 {
 	char filename[PATH_SIZE];
-	struct name_entry *name_loop;
-	FILE *f;
 
 	if (udev->test_run)
 		return 0;
 
-	/* don't write anything if udev created only the node with the
-	 * kernel name without any interesting data to remember
+	devpath_to_db_path(udev->dev->devpath, filename, sizeof(filename));
+	create_path(filename);
+	name_index(udev->dev->devpath, udev->name, 1);
+
+	/*
+	 * create only a symlink with the name as the target
+	 * if we don't have any interesting data to remember
 	 */
-	if (strcmp(udev->name, udev->kernel_name) == 0 &&
-	    list_empty(&udev->symlink_list) && list_empty(&udev->env_list) &&
+	if (list_empty(&udev->symlink_list) && list_empty(&udev->env_list) &&
 	    !udev->partitions && !udev->ignore_remove) {
-		dbg("nothing interesting to store in udevdb, skip");
-		goto exit;
-	}
+		dbg("nothing interesting to store, create symlink");
+		unlink(filename);
+		if (symlink(udev->name, filename) != 0) {
+			err("unable to create db link '%s': %s", filename, strerror(errno));
+			return -1;
+		}
+	} else {
+		struct name_entry *name_loop;
+		FILE *f;
+
+		unlink(filename);
+		f = fopen(filename, "w");
+		if (f == NULL) {
+			err("unable to create db file '%s': %s", filename, strerror(errno));
+			return -1;
+		}
+		dbg("storing data for device '%s' in '%s'", udev->dev->devpath, filename);
 
-	devpath_to_db_path(udev->devpath, filename, sizeof(filename));
-	create_path(filename);
-	f = fopen(filename, "w");
-	if (f == NULL) {
-		err("unable to create db file '%s': %s", filename, strerror(errno));
-		return -1;
+		fprintf(f, "N:%s\n", udev->name);
+		list_for_each_entry(name_loop, &udev->symlink_list, node) {
+			fprintf(f, "S:%s\n", name_loop->name);
+			name_index(udev->dev->devpath, name_loop->name, 1);
+		}
+		fprintf(f, "M:%u:%u\n", major(udev->devt), minor(udev->devt));
+		if (udev->partitions)
+			fprintf(f, "A:%u\n", udev->partitions);
+		if (udev->ignore_remove)
+			fprintf(f, "R:%u\n", udev->ignore_remove);
+		list_for_each_entry(name_loop, &udev->env_list, node)
+			fprintf(f, "E:%s\n", name_loop->name);
+		fclose(f);
 	}
-	dbg("storing data for device '%s' in '%s'", udev->devpath, filename);
-
-	fprintf(f, "N:%s\n", udev->name);
-	list_for_each_entry(name_loop, &udev->symlink_list, node)
-		fprintf(f, "S:%s\n", name_loop->name);
-	fprintf(f, "M:%u:%u\n", major(udev->devt), minor(udev->devt));
-	if (udev->partitions)
-		fprintf(f, "A:%u\n", udev->partitions);
-	if (udev->ignore_remove)
-		fprintf(f, "R:%u\n", udev->ignore_remove);
-	list_for_each_entry(name_loop, &udev->env_list, node)
-		fprintf(f, "E:%s\n", name_loop->name);
-	fclose(f);
-
-exit:
 	return 0;
 }
 
 int udev_db_get_device(struct udevice *udev, const char *devpath)
 {
+	struct stat stats;
 	char filename[PATH_SIZE];
 	char line[PATH_SIZE];
-	unsigned int major, minor;
+	unsigned int maj, min;
 	char *bufline;
 	char *buf;
 	size_t bufsize;
 	size_t cur;
 	size_t count;
 
+	strlcpy(udev->dev->devpath, devpath, sizeof(udev->dev->devpath));
 	devpath_to_db_path(devpath, filename, sizeof(filename));
-	if (file_map(filename, &buf, &bufsize) != 0) {
+
+	if (lstat(filename, &stats) != 0) {
 		info("no db file to read %s: %s", filename, strerror(errno));
 		return -1;
 	}
+	if ((stats.st_mode & S_IFMT) == S_IFLNK) {
+		char target[NAME_SIZE];
+		int target_len;
+
+		info("found a symlink as db file");
+		target_len = readlink(filename, target, sizeof(target));
+		if (target_len > 0)
+			target[target_len] = '\0';
+		else {
+			info("error reading db link %s: %s", filename, strerror(errno));
+			return -1;
+		}
+		dbg("db link points to '%s'", target);
+		strlcpy(udev->name, target, sizeof(udev->name));
+		return 0;
+	}
+
+	if (file_map(filename, &buf, &bufsize) != 0) {
+		info("error reading db file %s: %s", filename, strerror(errno));
+		return -1;
+	}
 
-	strlcpy(udev->devpath, devpath, sizeof(udev->devpath));
 	cur = 0;
 	while (cur < bufsize) {
 		count = buf_get_line(buf, bufsize, cur);
@@ -152,8 +188,8 @@ int udev_db_get_device(struct udevice *udev, const char *devpath)
 				count = sizeof(line);
 			memcpy(line, &bufline[2], count-2);
 			line[count-2] = '\0';
-			sscanf(line, "%u:%u", &major, &minor);
-			udev->devt = makedev(major, minor);
+			sscanf(line, "%u:%u", &maj, &min);
+			udev->devt = makedev(maj, min);
 			break;
 		case 'S':
 			if (count > sizeof(line))
@@ -196,37 +232,42 @@ int udev_db_get_device(struct udevice *udev, const char *devpath)
 int udev_db_delete_device(struct udevice *udev)
 {
 	char filename[PATH_SIZE];
+	struct name_entry *name_loop;
 
-	devpath_to_db_path(udev->devpath, filename, sizeof(filename));
+	devpath_to_db_path(udev->dev->devpath, filename, sizeof(filename));
 	unlink(filename);
 
+	name_index(udev->dev->devpath, udev->name, 0);
+	list_for_each_entry(name_loop, &udev->symlink_list, node)
+		name_index(udev->dev->devpath, name_loop->name, 0);
+
 	return 0;
 }
 
 int udev_db_lookup_name(const char *name, char *devpath, size_t len)
 {
-	char dbpath[PATH_MAX];
+	char dirname[PATH_MAX];
+	size_t start;
 	DIR *dir;
 	int found = 0;
 
-	strlcpy(dbpath, udev_root, sizeof(dbpath));
-	strlcat(dbpath, "/", sizeof(dbpath));
-	strlcat(dbpath, DB_DIR, sizeof(dbpath));
-	dir = opendir(dbpath);
+	strlcpy(dirname, udev_root, sizeof(dirname));
+	start = strlcat(dirname, "/"DB_NAME_INDEX_DIR"/", sizeof(dirname));
+	strlcat(dirname, name, sizeof(dirname));
+	path_encode(&dirname[start], sizeof(dirname) - start);
+
+	dir = opendir(dirname);
 	if (dir == NULL) {
-		err("unable to open udev_db '%s': %s", dbpath, strerror(errno));
+		info("no index directory '%s': %s", dirname, strerror(errno));
 		return -1;
 	}
 
+	info("found index directory '%s'", dirname);
 	while (!found) {
 		struct dirent *ent;
+		char device[PATH_SIZE];
 		char filename[PATH_SIZE];
-		char nodename[PATH_SIZE];
-		char *bufline;
-		char *buf;
-		size_t bufsize;
-		size_t cur;
-		size_t count;
+		struct stat statbuf;
 
 		ent = readdir(dir);
 		if (ent == NULL || ent->d_name[0] == '\0')
@@ -234,39 +275,17 @@ int udev_db_lookup_name(const char *name, char *devpath, size_t len)
 		if (ent->d_name[0] == '.')
 			continue;
 
-		snprintf(filename, sizeof(filename), "%s/%s", dbpath, ent->d_name);
-		filename[sizeof(filename)-1] = '\0';
-		dbg("looking at '%s'", filename);
+		strlcpy(device, ent->d_name, sizeof(device));
+		path_decode(device);
 
-		if (file_map(filename, &buf, &bufsize) != 0) {
-			err("unable to read db file '%s': %s", filename, strerror(errno));
-			continue;
-		}
-
-		cur = 0;
-		while (cur < bufsize && !found) {
-			count = buf_get_line(buf, bufsize, cur);
-			bufline = &buf[cur];
-			cur += count+1;
-
-			switch(bufline[0]) {
-			case 'N':
-			case 'S':
-				if (count > sizeof(nodename))
-					count = sizeof(nodename);
-				memcpy(nodename, &bufline[2], count-2);
-				nodename[count-2] = '\0';
-				dbg("compare '%s' '%s'", nodename, name);
-				if (strcmp(nodename, name) == 0) {
-					db_file_to_devpath(ent->d_name, devpath, len);
-					found = 1;
-				}
-				break;
-			default:
-				continue;
-			}
+		dbg("looking at '%s'", device);
+		strlcpy(filename, sysfs_path, sizeof(filename));
+		strlcat(filename, device, sizeof(filename));
+		if (stat(filename, &statbuf) == 0) {
+			strlcpy(devpath, device, len);
+			found = 1;
+			break;
 		}
-		file_unmap(buf, bufsize);
 	}
 
 	closedir(dir);
@@ -282,18 +301,16 @@ int udev_db_get_all_entries(struct list_head *name_list)
 	DIR *dir;
 
 	strlcpy(dbpath, udev_root, sizeof(dbpath));
-	strlcat(dbpath, "/", sizeof(dbpath));
-	strlcat(dbpath, DB_DIR, sizeof(dbpath));
+	strlcat(dbpath, "/"DB_DIR, sizeof(dbpath));
 	dir = opendir(dbpath);
 	if (dir == NULL) {
-		err("unable to open udev_db '%s': %s", dbpath, strerror(errno));
+		info("no udev_db available '%s': %s", dbpath, strerror(errno));
 		return -1;
 	}
 
 	while (1) {
 		struct dirent *ent;
-		char filename[PATH_SIZE] = "/";
-		size_t end, i;
+		char device[PATH_SIZE];
 
 		ent = readdir(dir);
 		if (ent == NULL || ent->d_name[0] == '\0')
@@ -301,12 +318,10 @@ int udev_db_get_all_entries(struct list_head *name_list)
 		if (ent->d_name[0] == '.')
 			continue;
 
-		end = strlcat(filename, ent->d_name, sizeof(filename));
-		for (i = 1; i < end; i++)
-			if (filename[i] == PATH_TO_NAME_CHAR)
-				filename[i] = '/';
-		name_list_add(name_list, filename, 1);
-		dbg("added '%s'", filename);
+		strlcpy(device, ent->d_name, sizeof(device));
+		path_decode(device);
+		name_list_add(name_list, device, 1);
+		dbg("added '%s'", device);
 	}
 
 	closedir(dir);