X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=udev_sysfs.c;h=e8909f94f1f6166249fbcad8f571d7c0baa2b790;hp=7431dd6111692ec0afcd73ff2af56626a6b43747;hb=6e509e539b15ae882afd8ce3fafe1fbd33008509;hpb=66ec64e9adcba6e619a48729f50c992875ed6c88

diff --git a/udev_sysfs.c b/udev_sysfs.c
index 7431dd611..e8909f94f 100644
--- a/udev_sysfs.c
+++ b/udev_sysfs.c
@@ -92,7 +92,6 @@ void sysfs_device_set_values(struct sysfs_device *dev, const char *devpath,
 	pos = strrchr(dev->devpath, '/');
 	if (pos == NULL)
 		return;
-
 	strlcpy(dev->kernel, &pos[1], sizeof(dev->kernel));
 	dbg("kernel='%s'", dev->kernel);
 
@@ -156,9 +155,21 @@ struct sysfs_device *sysfs_device_get(const char *devpath)
 	int len;
 	char *pos;
 
+	/* we handle only these devpathes */
+	if (devpath != NULL &&
+	    strncmp(devpath, "/devices/", 9) != 0 &&
+	    strncmp(devpath, "/subsystem/", 11) != 0 &&
+	    strncmp(devpath, "/module/", 8) != 0 &&
+	    strncmp(devpath, "/bus/", 5) != 0 &&
+	    strncmp(devpath, "/class/", 7) != 0 &&
+	    strncmp(devpath, "/block/", 7) != 0)
+		return NULL;
+
 	dbg("open '%s'", devpath);
 	strlcpy(devpath_real, devpath, sizeof(devpath_real));
 	remove_trailing_chars(devpath_real, '/');
+	if (devpath[0] == '\0' )
+		return NULL;
 
 	/* look for device already in cache (we never put an untranslated path in the cache) */
 	list_for_each_entry(dev_loop, &dev_list, node) {
@@ -216,7 +227,7 @@ struct sysfs_device *sysfs_device_get(const char *devpath)
 		if (pos != NULL)
 			pos[0] = '\0';
 		else
-			dev->subsystem[0] = '\0';
+			strlcpy(dev->subsystem, "subsystem", sizeof(dev->subsystem));
 	} else if (strncmp(dev->devpath, "/block/", 7) == 0) {
 		strlcpy(dev->subsystem, "block", sizeof(dev->subsystem));
 	} else if (strncmp(dev->devpath, "/devices/", 9) == 0) {
@@ -236,6 +247,14 @@ struct sysfs_device *sysfs_device_get(const char *devpath)
 		strlcpy(dev->subsystem, "drivers", sizeof(dev->subsystem));
 	} else if (strncmp(dev->devpath, "/module/", 8) == 0) {
 		strlcpy(dev->subsystem, "module", sizeof(dev->subsystem));
+	} else if (strncmp(dev->devpath, "/subsystem/", 11) == 0) {
+		pos = strrchr(dev->devpath, '/');
+		if (pos == &dev->devpath[10])
+			strlcpy(dev->subsystem, "subsystem", sizeof(dev->subsystem));
+	} else if (strncmp(dev->devpath, "/bus/", 5) == 0) {
+		pos = strrchr(dev->devpath, '/');
+		if (pos == &dev->devpath[4])
+			strlcpy(dev->subsystem, "subsystem", sizeof(dev->subsystem));
 	}
 
 	/* get driver name */
@@ -268,13 +287,6 @@ struct sysfs_device *sysfs_device_get_parent(struct sysfs_device *dev)
 	if (dev->parent != NULL)
 		return dev->parent;
 
-	/* requesting a parent is only valid for devices */
-	if ((strncmp(dev->devpath, "/devices/", 9) != 0) &&
-	    (strncmp(dev->devpath, "/subsystem/", 11) != 0) &&
-	    (strncmp(dev->devpath, "/class/", 7) != 0) &&
-	    (strncmp(dev->devpath, "/block/", 7) != 0))
-		return NULL;
-
 	strlcpy(parent_devpath, dev->devpath, sizeof(parent_devpath));
 	dbg("'%s'", parent_devpath);
 
@@ -284,20 +296,6 @@ struct sysfs_device *sysfs_device_get_parent(struct sysfs_device *dev)
 		return NULL;
 	pos[0] = '\0';
 
-	/* are we at the top level of /devices */
-	if (strcmp(parent_devpath, "/devices") == 0) {
-		dbg("/devices top level");
-		return NULL;
-	}
-
-	/* at the subsystems top level we want to follow the old-style "device" link */
-	if (strncmp(parent_devpath, "/subsystem", 10) == 0) {
-		pos = strrchr(parent_devpath, '/');
-		if (pos == &parent_devpath[10] || pos == parent_devpath || strcmp(pos, "/devices") == 0) {
-			dbg("/subsystem top level, look for device link");
-			goto device_link;
-		}
-	}
 	if (strncmp(parent_devpath, "/class", 6) == 0) {
 		pos = strrchr(parent_devpath, '/');
 		if (pos == &parent_devpath[6] || pos == parent_devpath) {
@@ -310,6 +308,11 @@ struct sysfs_device *sysfs_device_get_parent(struct sysfs_device *dev)
 		goto device_link;
 	}
 
+	/* are we at the top level? */
+	pos = strrchr(parent_devpath, '/');
+	if (pos == NULL || pos == parent_devpath)
+		return NULL;
+
 	/* get parent and remember it */
 	dev->parent = sysfs_device_get(parent_devpath);
 	return dev->parent;
@@ -352,6 +355,8 @@ char *sysfs_attr_get_value(const char *devpath, const char *attr_name)
 
 	dbg("open '%s'/'%s'", devpath, attr_name);
 	sysfs_len = strlcpy(path_full, sysfs_path, sizeof(path_full));
+	if(sysfs_len >= sizeof(path_full))
+		sysfs_len = sizeof(path_full) - 1;
 	path = &path_full[sysfs_len];
 	strlcat(path_full, devpath, sizeof(path_full));
 	strlcat(path_full, "/", sizeof(path_full));
@@ -410,7 +415,7 @@ char *sysfs_attr_get_value(const char *devpath, const char *attr_name)
 	/* read attribute value */
 	fd = open(path_full, O_RDONLY);
 	if (fd < 0) {
-		dbg("attribute '%s' does not exist", path_full);
+		dbg("attribute '%s' can not be opened", path_full);
 		goto out;
 	}
 	size = read(fd, value, sizeof(value));
@@ -430,3 +435,94 @@ char *sysfs_attr_get_value(const char *devpath, const char *attr_name)
 out:
 	return attr->value;
 }
+
+int sysfs_lookup_devpath_by_subsys_id(char *devpath_full, size_t len, const char *subsystem, const char *id)
+{
+	size_t sysfs_len;
+	char path_full[PATH_SIZE];
+	char *path;
+	struct stat statbuf;
+
+	sysfs_len = strlcpy(path_full, sysfs_path, sizeof(path_full));
+	path = &path_full[sysfs_len];
+
+	if (strcmp(subsystem, "subsystem") == 0) {
+		strlcpy(path, "/subsystem/", sizeof(path_full) - sysfs_len);
+		strlcat(path, id, sizeof(path_full) - sysfs_len);
+		if (stat(path_full, &statbuf) == 0)
+			goto found;
+
+		strlcpy(path, "/bus/", sizeof(path_full) - sysfs_len);
+		strlcat(path, id, sizeof(path_full) - sysfs_len);
+		if (stat(path_full, &statbuf) == 0)
+			goto found;
+		goto out;
+
+		strlcpy(path, "/class/", sizeof(path_full) - sysfs_len);
+		strlcat(path, id, sizeof(path_full) - sysfs_len);
+		if (stat(path_full, &statbuf) == 0)
+			goto found;
+	}
+
+	if (strcmp(subsystem, "module") == 0) {
+		strlcpy(path, "/module/", sizeof(path_full) - sysfs_len);
+		strlcat(path, id, sizeof(path_full) - sysfs_len);
+		if (stat(path_full, &statbuf) == 0)
+			goto found;
+		goto out;
+	}
+
+	if (strcmp(subsystem, "drivers") == 0) {
+		char subsys[NAME_SIZE];
+		char *driver;
+
+		strlcpy(subsys, id, sizeof(subsys));
+		driver = strchr(subsys, ':');
+		if (driver != NULL) {
+			driver[0] = '\0';
+			driver = &driver[1];
+			strlcpy(path, "/subsystem/", sizeof(path_full) - sysfs_len);
+			strlcat(path, subsys, sizeof(path_full) - sysfs_len);
+			strlcat(path, "/drivers/", sizeof(path_full) - sysfs_len);
+			strlcat(path, driver, sizeof(path_full) - sysfs_len);
+			if (stat(path_full, &statbuf) == 0)
+				goto found;
+
+			strlcpy(path, "/bus/", sizeof(path_full) - sysfs_len);
+			strlcat(path, subsys, sizeof(path_full) - sysfs_len);
+			strlcat(path, "/drivers/", sizeof(path_full) - sysfs_len);
+			strlcat(path, driver, sizeof(path_full) - sysfs_len);
+			if (stat(path_full, &statbuf) == 0)
+				goto found;
+		}
+		goto out;
+	}
+
+	strlcpy(path, "/subsystem/", sizeof(path_full) - sysfs_len);
+	strlcat(path, subsystem, sizeof(path_full) - sysfs_len);
+	strlcat(path, "/devices/", sizeof(path_full) - sysfs_len);
+	strlcat(path, id, sizeof(path_full) - sysfs_len);
+	if (stat(path_full, &statbuf) == 0)
+		goto found;
+
+	strlcpy(path, "/bus/", sizeof(path_full) - sysfs_len);
+	strlcat(path, subsystem, sizeof(path_full) - sysfs_len);
+	strlcat(path, "/devices/", sizeof(path_full) - sysfs_len);
+	strlcat(path, id, sizeof(path_full) - sysfs_len);
+	if (stat(path_full, &statbuf) == 0)
+		goto found;
+
+	strlcpy(path, "/class/", sizeof(path_full) - sysfs_len);
+	strlcat(path, subsystem, sizeof(path_full) - sysfs_len);
+	strlcat(path, "/", sizeof(path_full) - sysfs_len);
+	strlcat(path, id, sizeof(path_full) - sysfs_len);
+	if (stat(path_full, &statbuf) == 0)
+		goto found;
+out:
+	return 0;
+found:
+	if (S_ISLNK(statbuf.st_mode))
+		sysfs_resolve_link(path, sizeof(path_full) - sysfs_len);
+	strlcpy(devpath_full, path, len);
+	return 1;
+}