X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=udev_db.c;h=c3034f5037f1320e6090c43799eb747212ee0ce9;hb=38895e573c6f17014393dc35a9e53d5f016172c3;hp=d958c6173b2dacdb398c12436afa1ed0d1f2f5bd;hpb=db481105c2cf2092e1499736d6619bf194f91711;p=elogind.git

diff --git a/udev_db.c b/udev_db.c
index d958c6173..c3034f503 100644
--- a/udev_db.c
+++ b/udev_db.c
@@ -30,20 +30,16 @@
 #include <errno.h>
 #include <dirent.h>
 
-#include "libsysfs/sysfs/libsysfs.h"
-#include "udev_libc_wrapper.h"
 #include "udev.h"
-#include "udev_utils.h"
-#include "logging.h"
-#include "udev_db.h"
 
-#define PATH_TO_NAME_CHAR		'@'
 
-static int get_db_filename(const char *devpath, char *filename, size_t len)
+static int devpath_to_db_path(const char *devpath, char *filename, size_t len)
 {
 	size_t start, end, i;
 
-	start = strlcpy(filename, udev_db_path, len);
+	/* add location of db files */
+	strlcpy(filename, udev_root, len);
+	start = strlcat(filename, "/"DB_DIR, len);
 	end = strlcat(filename, devpath, len);
 	if (end > len)
 		end = len;
@@ -56,53 +52,74 @@ static int get_db_filename(const char *devpath, char *filename, size_t len)
 	return 0;
 }
 
+static int db_file_to_devpath(const char *filename, char *devpath, size_t len)
+{
+	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] = '/';
+
+	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);
+
+	/*
+	 * 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 &&
+	if (strcmp(udev->name, udev->dev->kernel) == 0 &&
 	    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;
-	}
-
-	get_db_filename(udev->devpath, filename, sizeof(filename));
-	create_path(filename);
-	f = fopen(filename, "w");
-	if (f == NULL) {
-		err("unable to create db file '%s'", filename);
-		return -1;
+		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;
+
+		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);
+
+		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);
 	}
-	dbg("storing data for device '%s' in '%s'", udev->devpath, filename);
-
-	fprintf(f, "P:%s\n", udev->devpath);
-	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;
 }
 
-static int parse_db_file(struct udevice *udev, const char *filename)
+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;
 	char *bufline;
@@ -111,8 +128,32 @@ static int parse_db_file(struct udevice *udev, const char *filename)
 	size_t cur;
 	size_t count;
 
+	strlcpy(udev->dev->devpath, devpath, sizeof(udev->dev->devpath));
+	devpath_to_db_path(devpath, filename, sizeof(filename));
+
+	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) {
-		dbg("no db file to read '%s'", filename);
+		info("error reading db file %s: %s", filename, strerror(errno));
 		return -1;
 	}
 
@@ -123,12 +164,6 @@ static int parse_db_file(struct udevice *udev, const char *filename)
 		cur += count+1;
 
 		switch(bufline[0]) {
-		case 'P':
-			if (count > sizeof(udev->devpath))
-				count = sizeof(udev->devpath);
-			memcpy(udev->devpath, &bufline[2], count-2);
-			udev->devpath[count-2] = '\0';
-			break;
 		case 'N':
 			if (count > sizeof(udev->name))
 				count = sizeof(udev->name);
@@ -185,32 +220,23 @@ int udev_db_delete_device(struct udevice *udev)
 {
 	char filename[PATH_SIZE];
 
-	get_db_filename(udev->devpath, filename, sizeof(filename));
+	devpath_to_db_path(udev->dev->devpath, filename, sizeof(filename));
 	unlink(filename);
 
 	return 0;
 }
 
-int udev_db_get_device(struct udevice *udev, const char *devpath)
-{
-	char filename[PATH_SIZE];
-
-	get_db_filename(devpath, filename, sizeof(filename));
-	if (parse_db_file(udev, filename) != 0)
-		return -1;
-
-	return 0;
-}
-
-int udev_db_search_name(char *devpath, size_t len, const char *name)
+int udev_db_lookup_name(const char *name, char *devpath, size_t len)
 {
+	char dbpath[PATH_MAX];
 	DIR *dir;
-	char path[PATH_SIZE];
 	int found = 0;
 
-	dir = opendir(udev_db_path);
+	strlcpy(dbpath, udev_root, sizeof(dbpath));
+	strlcat(dbpath, "/"DB_DIR, sizeof(dbpath));
+	dir = opendir(dbpath);
 	if (dir == NULL) {
-		err("unable to open udev_db '%s'", udev_db_path);
+		info("no udev_db available '%s': %s", dbpath, strerror(errno));
 		return -1;
 	}
 
@@ -218,6 +244,7 @@ int udev_db_search_name(char *devpath, size_t len, const char *name)
 		struct dirent *ent;
 		char filename[PATH_SIZE];
 		char nodename[PATH_SIZE];
+		struct stat stats;
 		char *bufline;
 		char *buf;
 		size_t bufsize;
@@ -227,16 +254,39 @@ int udev_db_search_name(char *devpath, size_t len, const char *name)
 		ent = readdir(dir);
 		if (ent == NULL || ent->d_name[0] == '\0')
 			break;
-
 		if (ent->d_name[0] == '.')
 			continue;
 
-		snprintf(filename, sizeof(filename), "%s/%s", udev_db_path, ent->d_name);
+		snprintf(filename, sizeof(filename), "%s/%s", dbpath, ent->d_name);
 		filename[sizeof(filename)-1] = '\0';
 		dbg("looking at '%s'", filename);
 
+		if (lstat(filename, &stats) != 0) {
+			info("unable to read %s: %s", filename, strerror(errno));
+			continue;
+		}
+		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);
+			if (strcmp(name, target) == 0) {
+				db_file_to_devpath(ent->d_name, devpath, len);
+				found =1;
+			}
+			continue;
+		}
+
 		if (file_map(filename, &buf, &bufsize) != 0) {
-			err("unable to read db file '%s'", filename);
+			info("unable to read db file '%s': %s", filename, strerror(errno));
 			continue;
 		}
 
@@ -247,12 +297,6 @@ int udev_db_search_name(char *devpath, size_t len, const char *name)
 			cur += count+1;
 
 			switch(bufline[0]) {
-			case 'P':
-				if (count > sizeof(path))
-					count = sizeof(path);
-				memcpy(path, &bufline[2], count-2);
-				path[count-2] = '\0';
-				break;
 			case 'N':
 			case 'S':
 				if (count > sizeof(nodename))
@@ -261,8 +305,8 @@ int udev_db_search_name(char *devpath, size_t len, const char *name)
 				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;
 				}
 				break;
 			default:
@@ -273,20 +317,22 @@ int udev_db_search_name(char *devpath, size_t len, const char *name)
 	}
 
 	closedir(dir);
-	if (found) {
-		strlcpy(devpath, path, len);
+	if (found)
 		return 0;
-	} else
+	else
 		return -1;
 }
 
 int udev_db_get_all_entries(struct list_head *name_list)
 {
+	char dbpath[PATH_MAX];
 	DIR *dir;
 
-	dir = opendir(udev_db_path);
+	strlcpy(dbpath, udev_root, sizeof(dbpath));
+	strlcat(dbpath, "/"DB_DIR, sizeof(dbpath));
+	dir = opendir(dbpath);
 	if (dir == NULL) {
-		err("unable to open udev_db '%s'", udev_db_path);
+		info("no udev_db available '%s': %s", dbpath, strerror(errno));
 		return -1;
 	}
 
@@ -298,7 +344,6 @@ int udev_db_get_all_entries(struct list_head *name_list)
 		ent = readdir(dir);
 		if (ent == NULL || ent->d_name[0] == '\0')
 			break;
-
 		if (ent->d_name[0] == '.')
 			continue;