chiark / gitweb /
[PATCH] udev - drop all methods :)
[elogind.git] / libsysfs / sysfs_device.c
index 185b5cf..66d5f9a 100644 (file)
@@ -3,7 +3,7 @@
  *
  * 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
 #include "sysfs.h"
 
 /**
+ * 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], path[SYSFS_PATH_MAX];
+       unsigned char target[SYSFS_PATH_MAX], *bus = NULL, *c = NULL;
+       struct dlist *buslist = NULL;
+
+       if (dev == NULL) {
+               errno = EINVAL;
+               return -1;
+       }
+
+       memset(subsys, 0, SYSFS_NAME_LEN);
+       strcat(subsys, "/");
+       strcpy(subsys, SYSFS_BUS_NAME);  /* subsys = /bus */
+       buslist = sysfs_open_subsystem_list(subsys);
+       if (buslist != NULL) {
+               dlist_for_each_data(buslist, bus, char) {
+                       memset(path, 0, SYSFS_PATH_MAX);
+                       strcpy(path, dev->path);
+                       c = strstr(path, "/devices");
+                       if (c == NULL) {
+                               dprintf("Invalid path to device %s\n", path);
+                               sysfs_close_list(buslist);
+                               return -1;
+                       }
+                       *c = '\0';
+                       strcat(path, "/");
+                       strcat(path, SYSFS_BUS_NAME);
+                       strcat(path, "/");
+                       strcat(path, bus);
+                       strcat(path, "/");
+                       strcat(path, SYSFS_DEVICES_NAME);
+                       strcat(path, "/");
+                       strcat(path, dev->bus_id);
+                       if ((sysfs_path_is_link(path)) == 0) {
+                               memset(target, 0, SYSFS_PATH_MAX);
+                               if ((sysfs_get_link(path, target, 
+                                                       SYSFS_PATH_MAX)) != 0) {
+                                       dprintf("Error getting link target\n");
+                                       sysfs_close_list(buslist);
+                                       return -1;
+                               }
+                               if (!(strncmp(target, dev->path, 
+                                                       SYSFS_PATH_MAX))) {
+                                       strcpy(dev->bus, bus);
+                                       sysfs_close_list(buslist);
+                                       return 0;
+                               }
+                       }
+                }
+                sysfs_close_list(buslist);
+        }
+        return -1;
+}
+
+/**
+ * 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_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
  */
 void sysfs_close_device(struct sysfs_device *dev)
 {
        if (dev != NULL) {
-               dev->next = NULL;
-               dev->driver = NULL;
+               if (dev->parent != NULL)
+                       sysfs_close_device(dev->parent);
                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);
        }
 }
@@ -49,151 +139,457 @@ static struct sysfs_device *alloc_device(void)
 }
 
 /**
- * sysfs_get_device_attr: searches dev's attributes by name
- * @dev: device to look through
- * @name: attribute name to get
- * returns sysfs_attribute reference with success or NULL with error.
+ * open_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_attribute *sysfs_get_device_attr(struct sysfs_device *dev,
-                                               const char *name)
+static struct sysfs_directory *open_device_dir(const unsigned char *path)
 {
-       struct sysfs_attribute *cur = NULL;
-       char attrname[SYSFS_NAME_LEN];
+       struct sysfs_directory *rdir = NULL;
 
-       if (dev == NULL || dev->directory == NULL || name == NULL) {
+       if (path == 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;
 
-               return cur;
+       rdir = sysfs_open_directory(path);
+       if (rdir == NULL) {
+               errno = EINVAL;
+               dprintf ("Device %s not supported on this system\n", path);
+               return NULL;
        }
-
-       return NULL;
+       if ((sysfs_read_dir_subdirs(rdir)) != 0) {
+               dprintf ("Error reading device at dir %s\n", path);
+               sysfs_close_directory(rdir);
+               return NULL;
+       }
+       
+       return rdir;
 }
 
 /**
- * sysfs_open_device: opens and populates device structure
+ * sysfs_open_device_path: opens and populates device structure
  * @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_path(const unsigned char *path)
 {
        struct sysfs_device *dev = NULL;
-       struct sysfs_directory *sdir = NULL;
-       char *p = NULL;
 
        if (path == NULL) {
                errno = EINVAL;
                return NULL;
        }
+       if ((sysfs_path_is_dir(path)) != 0) {
+               dprintf("Incorrect path to device: %s\n", path);
+               return 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) {
-               dprintf(stderr, "Invalid device at %s\n", path);
+       if ((sysfs_get_name_from_path(path, dev->bus_id, 
+                                       SYSFS_NAME_LEN)) != 0) {
                errno = EINVAL;
+               dprintf("Error getting device bus_id\n");
                sysfs_close_device(dev);
                return NULL;
        }
-       if ((sysfs_read_directory(sdir)) != 0) {
-               dprintf(stderr, "Error reading device directory at %s\n", path);
-               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->path, 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, dev->bus_id, SYSFS_NAME_LEN);
+       
+       if (get_device_bus(dev) != 0)
+               strcpy(dev->bus, SYSFS_UNKNOWN);
 
        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(path);
+       if (rootdev == NULL) {
+               dprintf("Error opening root device at %s\n", path);
+               return NULL;
+       }
+       if (rootdev->directory == NULL) {
+               rootdev->directory = open_device_dir(rootdev->path);
+               if (rootdev->directory == NULL) 
+                       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_close_dev_tree);
+                       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.
+ * sysfs_get_root_devices: opens up all the devices under this root device
+ * @root: root device to open devices for
+ * returns dlist of devices with success and NULL with error
  */
-struct sysfs_device *sysfs_open_device_tree(const char *path)
+struct dlist *sysfs_get_root_devices(struct sysfs_root_device *root)
 {
-       struct sysfs_device *rootdev = NULL, *new = NULL;
+       struct sysfs_device *dev = NULL;
        struct sysfs_directory *cur = NULL;
 
-       if (path == NULL) {
+       if (root == NULL) {
                errno = EINVAL;
                return NULL;
        }
-       rootdev = sysfs_open_device(path);
-       if (rootdev == NULL) {
-               dprintf(stderr, "Error opening root device at %s\n", path);
+       if (root->directory == NULL) {
+               root->directory = open_device_dir(root->path);
+               if (root->directory == NULL)
+                       return NULL;
+       }
+               
+       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 root->devices;
+}
+
+/**
+ * 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;
+       unsigned char rootpath[SYSFS_PATH_MAX];
+
+       if (name == NULL) {
+               errno = EINVAL;
                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);
+
+       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;
+       }
+
+       if (sysfs_trailing_slash(rootpath) == 0)
+               strcat(rootpath, "/");
+       strcat(rootpath, SYSFS_DEVICES_NAME);
+       strcat(rootpath, "/");
+       strcat(rootpath, name);
+       if ((sysfs_path_is_dir(rootpath)) != 0) {
+               errno = EINVAL;
+               dprintf("Invalid root device: %s\n", name);
+               return NULL;
+       }
+       root = (struct sysfs_root_device *)calloc
+                                       (1, sizeof(struct sysfs_root_device));
+       if (root == NULL) {
+               dprintf("calloc failure\n");
+               return NULL;
+       }
+       strcpy(root->name, name);
+       strcpy(root->path, rootpath);
+       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) 
+               return NULL;
+
+       if (device->directory == NULL) {
+               device->directory = sysfs_open_directory(device->path);
+               if (device->directory == NULL) 
+                       return NULL;
+       }
+       if (device->directory->attributes == NULL) {
+               if ((sysfs_read_dir_attributes(device->directory)) != 0)
+                       return NULL;
+       } else {
+               if ((sysfs_path_is_dir(device->path)) != 0) {
+                       dprintf("Device at %s no longer exists", device->path);
+                       return NULL;
+               }
+               if ((sysfs_refresh_attributes
+                               (device->directory->attributes)) != 0) {
+                       dprintf("Error refreshing device attributes\n");
                        return NULL;
                }
-               add_device_child_to_parent(rootdev, new);       
-               cur = cur->next;
        }
+       return (device->directory->attributes);
+}
 
-       return rootdev;
+/**
+ * sysfs_get_device_attr: searches dev's attributes by name
+ * @dev: device to look through
+ * @name: attribute name to get
+ * returns sysfs_attribute reference with success or NULL with error.
+ */
+struct sysfs_attribute *sysfs_get_device_attr(struct sysfs_device *dev,
+                                               const unsigned char *name)
+{
+       struct sysfs_attribute *cur = NULL;
+       struct dlist *attrlist = NULL;
+
+       if (dev == NULL || name == NULL) {
+               errno = EINVAL;
+               return NULL;
+       }
+
+       attrlist = sysfs_get_device_attributes(dev);
+       if (attrlist == NULL)
+               return NULL;
+
+       cur = sysfs_get_directory_attribute(dev->directory, 
+                       (unsigned char *)name);
+
+       return cur;
 }
+
+/**
+ * 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,
+               const unsigned char *bus, unsigned char *path, size_t psize)
+{
+       unsigned char bus_path[SYSFS_PATH_MAX];
+
+       if (device == NULL || path == NULL) {
+               errno = EINVAL;
+               return -1;
+       }
+
+       memset(bus_path, 0, SYSFS_PATH_MAX);
+       if (sysfs_get_mnt_path(bus_path, SYSFS_PATH_MAX) != 0) {
+               dprintf ("Sysfs not supported on this system\n");
+               return -1;
+       }
+       if (sysfs_trailing_slash(bus_path) == 0)
+               strcat(bus_path, "/");
+       strcat(bus_path, SYSFS_BUS_NAME);
+       strcat(bus_path, "/");
+       strcat(bus_path, bus);
+       strcat(bus_path, "/");
+       strcat(bus_path, SYSFS_DEVICES_NAME);
+       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_open_device: 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
+ * 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(const unsigned char *bus_id, 
+                                               const unsigned char *bus)
+{
+       char sysfs_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 ((get_device_absolute_path(bus_id, bus, sysfs_path, 
+                                               SYSFS_PATH_MAX)) != 0) {
+               dprintf("Error getting to device %s\n", bus_id);
+               return NULL;
+       }
+       
+       device = sysfs_open_device_path(sysfs_path);
+       if (device == NULL) {
+               dprintf("Error opening device %s\n", bus_id);
+               return NULL;
+       }
+
+       return device;
+}
+
+/**
+ * sysfs_get_device_parent: opens up given device's parent and returns a 
+ *     reference to its sysfs_device
+ * @dev: sysfs_device whose parent is requested
+ * Returns sysfs_device of the parent on success and NULL on failure
+ */
+struct sysfs_device *sysfs_get_device_parent(struct sysfs_device *dev)
+{
+       unsigned char ppath[SYSFS_PATH_MAX], *tmp = NULL;
+
+       if (dev == NULL) {
+               errno = EINVAL;
+               return NULL;
+       }
+
+       if (dev->parent != NULL)
+               return (dev->parent);
+
+       memset(ppath, 0, SYSFS_PATH_MAX);
+       strcpy(ppath, dev->path);
+       tmp = strrchr(ppath, '/');
+       if (tmp == NULL) {
+               dprintf("Invalid path to device %s\n", ppath);
+               return NULL;
+       }
+       if (*(tmp +1) == '\0') {
+               *tmp = '\0';
+               tmp = strrchr(tmp, '/');
+               if (tmp == NULL) {
+                       dprintf("Invalid path to device %s\n", ppath);
+                       return NULL;
+               }
+       }
+       *tmp = '\0';
+       
+       /*
+        * All "devices" have the "detach_state" attribute - validate here
+        */
+       strcat(ppath, "/detach_state");
+       if ((sysfs_path_is_file(ppath)) != 0) {
+               dprintf("Device at %s does not have a parent\n", dev->path);
+               return NULL;
+       }
+       tmp = strrchr(ppath, '/');
+       *tmp = '\0';
+       dev->parent = sysfs_open_device_path(ppath);
+       if (dev->parent == NULL) {
+               dprintf("Error opening device %s's parent at %s\n", 
+                                       dev->bus_id, ppath);
+               return NULL;
+       }
+       return (dev->parent);
+}
+
+/*
+ * 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 (bus == NULL || bus_id == NULL || attrib == NULL) {
+               errno = EINVAL;
+               return NULL;
+       }
+
+       memset(devpath, 0, SYSFS_PATH_MAX);
+       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, bus_id);
+               return NULL;
+       }
+       if ((sysfs_read_attribute(attribute)) != 0) {
+               dprintf("Error reading attribute %s for device %s\n",
+                               attrib, bus_id);
+               sysfs_close_attribute(attribute);
+               return NULL;
+       }
+       return attribute;
+}
+