[PATCH] libsysfs changes for sysfsutils 0.3.0

Here's the patch to up the library to the sysfsutils-0_3_0 level. The
following changes:

1) adds class name to sysfs_class_device structure
2) adds bus to sysfs_device
3) gets rid of code that made assumptions as to bus addresses being
unique across buses, which isn't the case.


I still owe you:

1) change getpagesize->sysconf. This is in the CVS tree and part of other
changes we're currently testing. Patch will follow.
2) you need a function to get a sysfs_class_device's parent. We hadn't
considered class devices to have parents, the one example of a multilevel
is the block class. We will add this function and send the patch to you.

1 files changed, 134 insertions, 135 deletions

diff --git a/libsysfs/sysfs_device.c b/libsysfs/sysfs_device.c
index 89704dcd80..fbd046f229 100644
--- a/libsysfs/sysfs_device.c
+++ b/libsysfs/sysfs_device.c
@@ -23,6 +23,77 @@
 #include "libsysfs.h"
 #include "sysfs.h"
 
+static int confirm_device_bus(struct sysfs_device *dev, 
+				unsigned char *busname, unsigned char *bus_id)
+{
+        struct sysfs_link *devlink = NULL;
+        unsigned char devpath[SYSFS_PATH_MAX];
+	int result = 0;
+
+        if (busname == NULL || bus_id == NULL)
+                return -1;
+
+        if (sysfs_get_mnt_path(devpath, SYSFS_PATH_MAX) != 0)
+                return -1;
+
+        strcat(devpath, SYSFS_BUS_DIR);
+        strcat(devpath, "/");
+        strcat(devpath, busname);
+        strcat(devpath, SYSFS_DEVICES_DIR);
+        strcat(devpath, "/");
+        strcat(devpath, bus_id);
+
+	devlink = sysfs_open_link(devpath);
+	if (devlink == NULL)
+		return -1;
+
+	if (strcmp(devlink->target, dev->path) == 0)
+		result++;
+	sysfs_close_link(devlink);
+	return result;
+}
+
+/**
+ * get_device_bus: retrieves the bus name the device is on, checks path to
+ *	bus' link to make sure it has correct device.
+ * @dev: device to get busname.
+ * returns 0 with success and -1 with error.
+ */
+static int get_device_bus(struct sysfs_device *dev)
+{
+	unsigned char subsys[SYSFS_NAME_LEN], *bus = NULL, *curdev = NULL;
+	struct dlist *buslist = NULL, *device_list = NULL;
+
+	if (dev == NULL) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	strcpy(subsys, SYSFS_BUS_DIR);  /* subsys = /bus */
+	buslist = sysfs_open_subsystem_list(subsys);
+	if (buslist != NULL) {
+		dlist_for_each_data(buslist, bus, char) {
+			device_list = sysfs_open_bus_devices_list(bus);
+			if (device_list != NULL) {
+				dlist_for_each_data(device_list,
+							curdev, char) {
+					if (strcmp(dev->bus_id, curdev) == 0
+					    && confirm_device_bus(dev, bus,
+					    curdev) > 0) {
+						strcpy(dev->bus, bus);
+                                                sysfs_close_list(device_list);
+                                                sysfs_close_list(buslist);
+                                                return 0;
+                                        }
+                                }
+                        sysfs_close_list(device_list);
+                        }
+                }
+                sysfs_close_list(buslist);
+        }
+        return -1;
+}
+
 /**
  * sysfs_close_device_tree: closes every device in the supplied tree, 
  * 	closing children only.
@@ -150,6 +221,9 @@ struct sysfs_device *sysfs_open_device(const unsigned char *path)
 	 * implies that the dev->name and dev->bus_id contain same data.
 	 */
 	strncpy(dev->name, sdir->name, SYSFS_NAME_LEN);
+	
+	if (get_device_bus(dev) != 0)
+		strcpy(dev->bus, SYSFS_UNKNOWN);
 
 	return dev;
 }
@@ -339,55 +413,6 @@ struct dlist *sysfs_get_device_attributes(struct sysfs_device *device)
 }
 
 /**
- * sysfs_open_device_by_id: open a device by id (use the "bus" subsystem)
- * @bus_id: bus_id of the device to open - has to be the "bus_id" in 
- * 		/sys/bus/xxx/devices
- * @bus: bus the device belongs to
- * @bsize: size of the bus buffer
- * returns struct sysfs_device if found, NULL otherwise
- * NOTE: 
- * 1. Use sysfs_close_device to close the device
- * 2. Bus the device is on must be supplied
- * 	Use sysfs_find_device_bus to get the bus name
- */
-struct sysfs_device *sysfs_open_device_by_id(const unsigned char *bus_id, 
-		const unsigned char *bus, size_t bsize)
-{
-	char sysfs_path[SYSFS_PATH_MAX], device_path[SYSFS_PATH_MAX];
-	struct sysfs_device *device = NULL;
-
-	if (bus_id == NULL || bus == NULL) {
-		errno = EINVAL;
-		return NULL;
-	}
-	memset(sysfs_path, 0, SYSFS_PATH_MAX);
-	if ((sysfs_get_mnt_path(sysfs_path, SYSFS_PATH_MAX)) != 0) {
-		dprintf("Error getting sysfs mount path\n");
-		return NULL;
-	}
-	strcat(sysfs_path, SYSFS_BUS_DIR);
-	strcat(sysfs_path, "/");
-	strncat(sysfs_path, bus, bsize);
-	strcat(sysfs_path, SYSFS_DEVICES_DIR);
-	strcat(sysfs_path, "/");
-	strcat(sysfs_path, bus_id);
-
-	/* devices under /sys/bus/xxx/devices are links to devices subsystem */
-	if ((sysfs_get_link(sysfs_path, device_path, SYSFS_PATH_MAX)) < 0) {
-		dprintf("Error getting device path\n");
-		return NULL;
-	}
-	
-	device = sysfs_open_device(device_path);
-	if (device == NULL) {
-		dprintf("Error opening device %s\n", bus_id);
-		return NULL;
-	}
-
-	return device;
-}
-
-/**
  * get_device_absolute_path: looks up the bus the device is on, gets 
  * 		absolute path to the device
  * @device: device for which path is needed
@@ -395,29 +420,24 @@ struct sysfs_device *sysfs_open_device_by_id(const unsigned char *bus_id,
  * @psize: size of "path"
  * Returns 0 on success -1 on failure
  */
-static int get_device_absolute_path(const unsigned char *device, 
-					unsigned char *path, size_t psize)
+static int get_device_absolute_path(const unsigned char *device,
+		const unsigned char *bus, unsigned char *path, size_t psize)
 {
-	unsigned char bus_name[SYSFS_NAME_LEN], bus_path[SYSFS_PATH_MAX];
+	unsigned char bus_path[SYSFS_NAME_LEN];
 
 	if (device == NULL || path == NULL) {
 		errno = EINVAL;
 		return -1;
 	}
 
-	memset(bus_name, 0, SYSFS_NAME_LEN);
 	memset(bus_path, 0, SYSFS_NAME_LEN);
-	if ((sysfs_find_device_bus(device, bus_name, SYSFS_NAME_LEN)) != 0) {
-		dprintf("Device %s not found\n", device);
-		return -1;
-	}
 	if (sysfs_get_mnt_path(bus_path, SYSFS_PATH_MAX) != 0) {
 		dprintf ("Sysfs not supported on this system\n");
 		return -1;
 	}
 	strcat(bus_path, SYSFS_BUS_DIR);
 	strcat(bus_path, "/");
-	strcat(bus_path, bus_name);
+	strcat(bus_path, bus);
 	strcat(bus_path, SYSFS_DEVICES_DIR);
 	strcat(bus_path, "/");
 	strcat(bus_path, device);
@@ -433,106 +453,85 @@ static int get_device_absolute_path(const unsigned char *device,
 }
 
 /**
- * sysfs_write_device_attr: modify a "writable" attribute for the given device
- * @dev: device bus_id for which attribute has to be changed
- * @attrib: attribute to change
- * @value: value to change to
- * @len: "value" length to write
- * Returns 0 on success -1 on error
- */ 
-int sysfs_write_device_attr(unsigned char *dev, unsigned char *attrib,
-					unsigned char *value, size_t len)
+ * sysfs_open_device_by_id: open a device by id (use the "bus" subsystem)
+ * @bus_id: bus_id of the device to open - has to be the "bus_id" in 
+ * 		/sys/bus/xxx/devices
+ * @bus: bus the device belongs to
+ * @bsize: size of the bus buffer
+ * returns struct sysfs_device if found, NULL otherwise
+ * NOTE: 
+ * 1. Use sysfs_close_device to close the device
+ * 2. Bus the device is on must be supplied
+ * 	Use sysfs_find_device_bus to get the bus name
+ */
+struct sysfs_device *sysfs_open_device_by_id(const unsigned char *bus_id, 
+		const unsigned char *bus, size_t bsize)
 {
-	struct sysfs_attribute *attribute = NULL;
-	unsigned char devpath[SYSFS_PATH_MAX];
+	char sysfs_path[SYSFS_PATH_MAX];
+	struct sysfs_device *device = NULL;
 
-	if (dev == NULL || attrib == NULL || value == NULL) {
+	if (bus_id == NULL || bus == NULL) {
 		errno = EINVAL;
-		return -1;
-	}
-	
-	memset(devpath, 0, SYSFS_PATH_MAX);
-	if ((get_device_absolute_path(dev, devpath, SYSFS_PATH_MAX)) != 0) {
-		dprintf("Error finding absolute path to device %s\n", dev);
-		return -1;
-	}
-	strcat(devpath, "/");
-	strcat(devpath, attrib);
-	attribute = sysfs_open_attribute(devpath);
-	if (attribute == NULL) {
-		dprintf("Attribute %s could not be retrieved for device %s\n",
-				attrib, dev);
-		return -1;
+		return NULL;
 	}
-	if (attribute->method & SYSFS_METHOD_SHOW) {
-		if ((sysfs_read_attribute(attribute)) != 0) {
-			dprintf("Error reading attribute %s for device %s\n",
-					attrib, dev);
-			sysfs_close_attribute(attribute);
-			return -1;
-		}
+	memset(sysfs_path, 0, SYSFS_PATH_MAX);
+	if ((get_device_absolute_path(bus_id, bus, sysfs_path, 
+						SYSFS_PATH_MAX)) != 0) {
+		dprintf("Error getting to device %s\n", bus_id);
+		return NULL;
 	}
-	if ((sysfs_write_attribute(attribute, value, len)) < 0) {
-		dprintf("Error setting %s to %s\n", attrib, value);
-		sysfs_close_attribute(attribute);
-		return -1;
+	
+	device = sysfs_open_device(sysfs_path);
+	if (device == NULL) {
+		dprintf("Error opening device %s\n", bus_id);
+		return NULL;
 	}
-	sysfs_close_attribute(attribute);
-	return 0;
+
+	return device;
 }
 
-/**
- * sysfs_read_device_attr: read an attribute of the given device
- * @dev: device bus_id for which attribute has to be changed
- * @attrib: attribute to read
- * @value: buffer to return value in
- * @len: size of buffer available
- * Returns 0 on success -1 on error
- */ 
-int sysfs_read_device_attr(unsigned char *dev, unsigned char *attrib,
-					unsigned char *value, size_t len)
+/*
+ * sysfs_open_device_attr: open the given device's attribute
+ * @bus: Bus on which to look
+ * @dev_id: device for which attribute is required
+ * @attrname: name of the attribute to look for
+ * Returns struct sysfs_attribute on success and NULL on failure
+ * 
+ * NOTE:
+ * 	A call to sysfs_close_attribute() is required to close
+ * 	the attribute returned and free memory. 
+ */
+struct sysfs_attribute *sysfs_open_device_attr(const unsigned char *bus,
+		const unsigned char *bus_id, const unsigned char *attrib)
 {
 	struct sysfs_attribute *attribute = NULL;
 	unsigned char devpath[SYSFS_PATH_MAX];
-
-	if (dev == NULL || attrib == NULL || value == NULL) {
+	
+	if (bus == NULL || bus_id == NULL || attrib == NULL) {
 		errno = EINVAL;
-		return -1;
+		return NULL;
 	}
-	
+
 	memset(devpath, 0, SYSFS_PATH_MAX);
-	if ((get_device_absolute_path(dev, devpath, SYSFS_PATH_MAX)) != 0) {
-		dprintf("Error finding absolute path to device %s\n", dev);
-		return -1;
+	if ((get_device_absolute_path(bus_id, bus, devpath, 
+					SYSFS_PATH_MAX)) != 0) {
+		dprintf("Error getting to device %s\n", bus_id);
+		return NULL;
 	}
 	strcat(devpath, "/");
 	strcat(devpath, attrib);
 	attribute = sysfs_open_attribute(devpath);
 	if (attribute == NULL) {
 		dprintf("Error opening attribute %s for device %s\n",
-				attrib, dev);
-		return -1;
-	}
-	if (!(attribute->method & SYSFS_METHOD_SHOW)) {
-		dprintf("Show method not supported for attribute %s\n",
-				attrib);
-		sysfs_close_attribute(attribute);
-		return -1;
+				attrib, bus_id);
+		return NULL;
 	}
 	if ((sysfs_read_attribute(attribute)) != 0) {
 		dprintf("Error reading attribute %s for device %s\n",
-				attrib, dev);
+				attrib, bus_id);
 		sysfs_close_attribute(attribute);
-		return -1;
-	}
-	if (attribute->len > len) {
-		dprintf("Value length %d is larger than supplied buffer %d\n",
-				attribute->len, len);
-		sysfs_close_attribute(attribute);
-		return -1;
+		return NULL;
 	}
-	strncpy(value, attribute->value, attribute->len);
-	value[(attribute->len)+1] = 0;
-	sysfs_close_attribute(attribute);
-	return 0;
+	return attribute;
 }
+