[PATCH] new version of libsysfs patch

[elogind.git] / libsysfs / sysfs_device.c

diff --git a/libsysfs/sysfs_device.c b/libsysfs/sysfs_device.c
index 185b5cf3780458bddcacde154afaa90a60c46f49..89704dcd8041092abf6b9f8e6c6362a1bf43ba84 100644 (file)
--- a/libsysfs/sysfs_device.c
+++ b/libsysfs/sysfs_device.c
@@ -3,7 +3,7 @@
  *
  * Generic device utility functions for libsysfs
  *
  *
  * Generic device utility functions for libsysfs
  *

- * Copyright (C) 2003 International Business Machines, Inc.
+ * Copyright (C) IBM Corp. 2003

  *
  *  This library is free software; you can redistribute it and/or
  *  modify it under the terms of the GNU Lesser General Public
  *
  *  This library is free software; you can redistribute it and/or
  *  modify it under the terms of the GNU Lesser General Public


@@ -23,6 +23,42 @@
 #include "libsysfs.h"
 #include "sysfs.h"
 
 #include "libsysfs.h"
 #include "sysfs.h"
 

+/**
+ * sysfs_close_device_tree: closes every device in the supplied tree, 
+ *     closing children only.
+ * @devroot: device root of tree.
+ */
+static void sysfs_close_device_tree(struct sysfs_device *devroot)
+{
+       if (devroot != NULL) {
+               if (devroot->children != NULL) {
+                       struct sysfs_device *child = NULL;
+
+                       dlist_for_each_data(devroot->children, child,
+                                       struct sysfs_device) {
+                               sysfs_close_device_tree(child);
+                       }
+               }
+               sysfs_close_device(devroot);
+       }
+}
+
+/**
+ * sysfs_del_device: routine for dlist integration
+ */
+static void sysfs_del_device(void *dev)
+{
+       sysfs_close_device((struct sysfs_device *)dev);
+}
+
+/**
+ * sysfs_close_dev_tree: routine for dlist integration
+ */
+static void sysfs_close_dev_tree(void *dev)
+{
+       sysfs_close_device_tree((struct sysfs_device *)dev);
+}
+

 /**
  * sysfs_close_device: closes and cleans up a device
  * @dev = device to clean up
 /**
  * sysfs_close_device: closes and cleans up a device
  * @dev = device to clean up


@@ -30,11 +66,10 @@
 void sysfs_close_device(struct sysfs_device *dev)
 {
        if (dev != NULL) {
 void sysfs_close_device(struct sysfs_device *dev)
 {
        if (dev != NULL) {

-               dev->next = NULL;
-               dev->driver = NULL;

                if (dev->directory != NULL)
                        sysfs_close_directory(dev->directory);
                if (dev->directory != NULL)
                        sysfs_close_directory(dev->directory);

-               dev->children = NULL;
+               if (dev->children != NULL && dev->children->count == 0)
+                       dlist_destroy(dev->children);

                free(dev);
        }
 }
                free(dev);
        }
 }


@@ -55,24 +90,20 @@ static struct sysfs_device *alloc_device(void)
  * returns sysfs_attribute reference with success or NULL with error.
  */
 struct sysfs_attribute *sysfs_get_device_attr(struct sysfs_device *dev,
  * returns sysfs_attribute reference with success or NULL with error.
  */
 struct sysfs_attribute *sysfs_get_device_attr(struct sysfs_device *dev,

-                                               const char *name)
+                                               const unsigned char *name)

 {
        struct sysfs_attribute *cur = NULL;
 {
        struct sysfs_attribute *cur = NULL;

-       char attrname[SYSFS_NAME_LEN];

 
 

-       if (dev == NULL || dev->directory == NULL || name == NULL) {
+       if (dev == NULL || dev->directory == NULL 
+           || dev->directory->attributes == NULL || name == NULL) {

                errno = EINVAL;
                return NULL;
        }
                errno = EINVAL;
                return NULL;
        }

-       for (cur = dev->directory->attributes; cur != NULL; cur = cur->next) {
-               if ((sysfs_get_name_from_path(cur->path, attrname, 
-                   SYSFS_NAME_LEN)) != 0) 
-                       continue;
-               if (strcmp(name, attrname) != 0)
-                       continue;
-
+       
+       cur = sysfs_get_directory_attribute(dev->directory, 
+                       (unsigned char *)name);
+       if (cur != NULL)

                return cur;
                return cur;

-       }

 
        return NULL;
 }
 
        return NULL;
 }


@@ -82,11 +113,10 @@ struct sysfs_attribute *sysfs_get_device_attr(struct sysfs_device *dev,
  * @path: path to device, this is the /sys/devices/ path
  * returns sysfs_device structure with success or NULL with error
  */
  * @path: path to device, this is the /sys/devices/ path
  * returns sysfs_device structure with success or NULL with error
  */

-struct sysfs_device *sysfs_open_device(const char *path)
+struct sysfs_device *sysfs_open_device(const unsigned char *path)

 {
        struct sysfs_device *dev = NULL;
        struct sysfs_directory *sdir = NULL;
 {
        struct sysfs_device *dev = NULL;
        struct sysfs_directory *sdir = NULL;

-       char *p = NULL;

 
        if (path == NULL) {
                errno = EINVAL;
 
        if (path == NULL) {
                errno = EINVAL;


@@ -94,106 +124,415 @@ struct sysfs_device *sysfs_open_device(const char *path)
        }
        dev = alloc_device();   
        if (dev == NULL) {
        }
        dev = alloc_device();   
        if (dev == NULL) {

-               dprintf(stderr, "Error allocating device at %s\n", path);
+               dprintf("Error allocating device at %s\n", path);

                return NULL;
        }
        sdir = sysfs_open_directory(path);
        if (sdir == NULL) {
                return NULL;
        }
        sdir = sysfs_open_directory(path);
        if (sdir == NULL) {

-               dprintf(stderr, "Invalid device at %s\n", path);
+               dprintf("Invalid device at %s\n", path);

                errno = EINVAL;
                sysfs_close_device(dev);
                return NULL;
        }
        if ((sysfs_read_directory(sdir)) != 0) {
                errno = EINVAL;
                sysfs_close_device(dev);
                return NULL;
        }
        if ((sysfs_read_directory(sdir)) != 0) {

-               dprintf(stderr, "Error reading device directory at %s\n", path);
+               dprintf("Error reading device directory at %s\n", path);

                sysfs_close_directory(sdir);
                sysfs_close_device(dev);
                return NULL;
        }
        dev->directory = sdir;
                sysfs_close_directory(sdir);
                sysfs_close_device(dev);
                return NULL;
        }
        dev->directory = sdir;

-       sysfs_get_name_from_path(sdir->path, dev->bus_id, SYSFS_NAME_LEN);
-       /* get device name */
-       p = sysfs_get_value_from_attributes(sdir->attributes,   
-                                                       SYSFS_NAME_ATTRIBUTE);
-       if (p != NULL) {
-               strncpy(dev->name, p, SYSFS_NAME_LEN);
-               p = dev->name + strlen(dev->name) - 1;
-               if ((strlen(dev->name) > 0) && *p == '\n')
-                       *p = '\0';
-       }
+       strcpy(dev->bus_id, sdir->name);
+       strcpy(dev->path, sdir->path);
+
+       /* 
+        * The "name" attribute no longer exists... return the device's
+        * sysfs representation instead, in the "dev->name" field, which
+        * implies that the dev->name and dev->bus_id contain same data.
+        */
+       strncpy(dev->name, sdir->name, SYSFS_NAME_LEN);

 
        return dev;
 }
 
 /**
 
        return dev;
 }
 
 /**

- * sysfs_close_device_tree: closes every device in the supplied tree, 
- *     closing children only.
- * @devroot: device root of tree.
+ * sysfs_open_device_tree: opens root device and all of its children,
+ *     creating a tree of devices. Only opens children.
+ * @path: sysfs path to devices
+ * returns struct sysfs_device and its children with success or NULL with
+ *     error.

  */
  */

-void sysfs_close_device_tree(struct sysfs_device *devroot)
+static struct sysfs_device *sysfs_open_device_tree(const unsigned char *path)

 {
 {

-       if (devroot != NULL) {
-               if (devroot->children != NULL) {
-                       struct sysfs_device *child = NULL, *next = NULL;
-       
-                       for (child = devroot->children; child != NULL;
-                            child = next) {
-                               next = child->next;
-                               sysfs_close_device_tree(child);
+       struct sysfs_device *rootdev = NULL, *new = NULL;
+       struct sysfs_directory *cur = NULL;
+
+       if (path == NULL) {
+               errno = EINVAL;
+               return NULL;
+       }
+       rootdev = sysfs_open_device(path);
+       if (rootdev == NULL) {
+               dprintf("Error opening root device at %s\n", path);
+               return NULL;
+       }
+       if (rootdev->directory->subdirs != NULL) {
+               dlist_for_each_data(rootdev->directory->subdirs, cur,
+                               struct sysfs_directory) {
+                       new = sysfs_open_device_tree(cur->path);
+                       if (new == NULL) {
+                               dprintf("Error opening device tree at %s\n",
+                                       cur->path);
+                               sysfs_close_device_tree(rootdev);
+                               return NULL;

                        }
                        }

+                       if (rootdev->children == NULL)
+                               rootdev->children = dlist_new_with_delete
+                                       (sizeof(struct sysfs_device),
+                                       sysfs_del_device);
+                       dlist_unshift(rootdev->children, new);

                }
                }

-               sysfs_close_device(devroot);

        }
        }

+
+       return rootdev;

 }
 
 /**
 }
 
 /**

- * add_device_child_to_parent: adds child device to parent
- * @parent: parent device.
- * @child: child device to add.
+ * sysfs_close_root_device: closes root and all devices
+ * @root: root device to close

  */
  */

-static void add_device_child_to_parent(struct sysfs_device *parent,
-                                       struct sysfs_device *child)
+void sysfs_close_root_device(struct sysfs_root_device *root)

 {
 {

-       if (parent != NULL && child != NULL) {
-               child->next = parent->children;
-               parent->children = child;
-               child->parent = parent;
+       if (root != NULL) {
+               if (root->devices != NULL)
+                       dlist_destroy(root->devices);
+               if (root->directory != NULL)
+                       sysfs_close_directory(root->directory);
+               free(root);

        }
 }
 
 /**
        }
 }
 
 /**

- * sysfs_open_device_tree: opens root device and all of its children,
- *     creating a tree of devices. Only opens children.
- * @path: sysfs path to devices
- * returns struct sysfs_device and its children with success or NULL with
- *     error.
+ * open_root_device_dir: opens up sysfs_directory for specific root dev
+ * @name: name of root
+ * returns struct sysfs_directory with success and NULL with error

  */
  */

-struct sysfs_device *sysfs_open_device_tree(const char *path)
+static struct sysfs_directory *open_root_device_dir(const unsigned char *name)

 {
 {

-       struct sysfs_device *rootdev = NULL, *new = NULL;
+       struct sysfs_directory *rdir = NULL;
+       unsigned char rootpath[SYSFS_PATH_MAX];
+
+       if (name == NULL) {
+               errno = EINVAL;
+               return NULL;
+       }
+
+       memset(rootpath, 0, SYSFS_PATH_MAX);
+       if (sysfs_get_mnt_path(rootpath, SYSFS_PATH_MAX) != 0) {
+               dprintf ("Sysfs not supported on this system\n");
+               return NULL;
+       }
+
+       strcat(rootpath, SYSFS_DEVICES_DIR);
+       strcat(rootpath, "/");
+       strcat(rootpath, name);
+       rdir = sysfs_open_directory(rootpath);
+       if (rdir == NULL) {
+               errno = EINVAL;
+               dprintf ("Root device %s not supported on this system\n",
+                       name);
+               return NULL;
+       }
+       if (sysfs_read_directory(rdir) != 0) {
+               dprintf ("Error reading %s root device at dir %s\n", name,
+                       rootpath);
+               sysfs_close_directory(rdir);
+               return NULL;
+       }
+       
+       return rdir;
+}
+
+/**
+ * get_all_root_devices: opens up all the devices under this root device
+ * @root: root device to open devices for
+ * returns 0 with success and -1 with error
+ */
+static int get_all_root_devices(struct sysfs_root_device *root)
+{
+       struct sysfs_device *dev = NULL;

        struct sysfs_directory *cur = NULL;
 
        struct sysfs_directory *cur = NULL;
 

-       if (path == NULL) {
+       if (root == NULL || root->directory == NULL) {
+               errno = EINVAL;
+               return -1;
+       }
+       if (root->directory->subdirs == NULL)
+               return 0;
+
+       dlist_for_each_data(root->directory->subdirs, cur,
+                       struct sysfs_directory) {
+               dev = sysfs_open_device_tree(cur->path);
+               if (dev == NULL) {
+                       dprintf ("Error opening device at %s\n", cur->path);
+                       continue;
+               }
+               if (root->devices == NULL)
+                       root->devices = dlist_new_with_delete
+                               (sizeof(struct sysfs_device), 
+                               sysfs_close_dev_tree);
+               dlist_unshift(root->devices, dev);
+       }
+
+       return 0;
+}
+
+/**
+ * sysfs_open_root_device: opens sysfs devices root and all of its
+ *     devices.
+ * @name: name of /sys/devices/root to open
+ * returns struct sysfs_root_device if success and NULL with error
+ */
+struct sysfs_root_device *sysfs_open_root_device(const unsigned char *name)
+{
+       struct sysfs_root_device *root = NULL;
+       struct sysfs_directory *rootdir = NULL;
+
+       if (name == NULL) {

                errno = EINVAL;
                return NULL;
        }
                errno = EINVAL;
                return NULL;
        }

-       rootdev = sysfs_open_device(path);
-       if (rootdev == NULL) {
-               dprintf(stderr, "Error opening root device at %s\n", path);
+
+       root = (struct sysfs_root_device *)calloc
+                                       (1, sizeof(struct sysfs_root_device));
+       if (root == NULL) {
+               dprintf("calloc failure\n");
+               return NULL;
+       }
+       rootdir = open_root_device_dir(name);
+       if (rootdir == NULL) {
+               dprintf ("Invalid root device, %s not supported\n", name);
+               sysfs_close_root_device(root);
+               return NULL;
+       }
+       strcpy(root->path, rootdir->path);
+       root->directory = rootdir;
+       if (get_all_root_devices(root) != 0) {
+               dprintf ("Error retrieving devices for root %s\n", name);
+               sysfs_close_root_device(root);
+               return NULL;
+       }
+
+       return root;
+}
+
+/**
+ * sysfs_get_device_attributes: returns a dlist of attributes corresponding to
+ *     the specific device
+ * @device: struct sysfs_device * for which attributes are to be returned
+ */
+struct dlist *sysfs_get_device_attributes(struct sysfs_device *device)
+{
+       if (device == NULL || device->directory == NULL) 
+               return NULL;
+
+       return (device->directory->attributes);
+}
+
+/**
+ * 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 NULL;
        }

-       cur = rootdev->directory->subdirs;
-       while (cur != NULL) {
-               new = sysfs_open_device_tree(cur->path);
-               if (new == NULL) {
-                       dprintf(stderr, "Error opening device tree at %s\n",
-                               cur->path);
-                       sysfs_close_device_tree(rootdev);
-                       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
+ * @path: buffer to store absolute path
+ * @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)
+{
+       unsigned char bus_name[SYSFS_NAME_LEN], bus_path[SYSFS_PATH_MAX];
+
+       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, SYSFS_DEVICES_DIR);
+       strcat(bus_path, "/");
+       strcat(bus_path, device);
+       /*
+        * We now are at /sys/bus/"bus_name"/devices/"device" which is a link.
+        * Now read this link to reach to the device.
+        */ 
+       if ((sysfs_get_link(bus_path, path, SYSFS_PATH_MAX)) != 0) {
+               dprintf("Error getting to device %s\n", device);
+               return -1;
+       }
+       return 0;
+}
+
+/**
+ * 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)
+{
+       struct sysfs_attribute *attribute = NULL;
+       unsigned char devpath[SYSFS_PATH_MAX];
+
+       if (dev == NULL || attrib == NULL || value == 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;
+       }
+       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;

                }
                }

-               add_device_child_to_parent(rootdev, new);       
-               cur = cur->next;

        }
        }

+       if ((sysfs_write_attribute(attribute, value, len)) < 0) {
+               dprintf("Error setting %s to %s\n", attrib, value);
+               sysfs_close_attribute(attribute);
+               return -1;
+       }
+       sysfs_close_attribute(attribute);
+       return 0;
+}

 
 

-       return rootdev;
+/**
+ * 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)
+{
+       struct sysfs_attribute *attribute = NULL;
+       unsigned char devpath[SYSFS_PATH_MAX];
+
+       if (dev == NULL || attrib == NULL || value == 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("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;
+       }
+       if ((sysfs_read_attribute(attribute)) != 0) {
+               dprintf("Error reading attribute %s for device %s\n",
+                               attrib, dev);
+               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;
+       }
+       strncpy(value, attribute->value, attribute->len);
+       value[(attribute->len)+1] = 0;
+       sysfs_close_attribute(attribute);
+       return 0;

 }
 }