eudev/libsysfs/sysfs_device.c
dsteklof@us.ibm.com b376d32cb4 [PATCH] quick fix for libsysfs bus
There seems to be a
mismatch in udev and in libsysfs as to what to expect if the mnt point
has a slash on the end or not. If I use the included patch, it breaks
something in udev. If I patch sysfs_get_mnt_path I break udev as well
because what you're expecting. I need to sit down and go through
the library and creaate a rule as to trailing slashes. Adding the env
brought this to light.
2005-04-26 21:13:04 -07:00

542 lines
14 KiB
C

/*
* sysfs_device.c
*
* Generic device utility functions for libsysfs
*
* 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
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#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];
unsigned char *s = NULL;
int result = 0;
if (busname == NULL || bus_id == NULL)
return -1;
if (sysfs_get_mnt_path(devpath, SYSFS_PATH_MAX) != 0)
return -1;
s = &devpath[strlen(devpath)-1];
if (strncmp(s, "/", 1) == 0)
*s = '\0';
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.
* @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
*/
void sysfs_close_device(struct sysfs_device *dev)
{
if (dev != NULL) {
if (dev->directory != NULL)
sysfs_close_directory(dev->directory);
if (dev->children != NULL && dev->children->count == 0)
dlist_destroy(dev->children);
free(dev);
}
}
/**
* alloc_device: allocates and initializes device structure
* returns struct sysfs_device
*/
static struct sysfs_device *alloc_device(void)
{
return (struct sysfs_device *)calloc(1, sizeof(struct sysfs_device));
}
/**
* 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;
if (dev == NULL || dev->directory == NULL
|| dev->directory->attributes == NULL || name == NULL) {
errno = EINVAL;
return NULL;
}
cur = sysfs_get_directory_attribute(dev->directory,
(unsigned char *)name);
if (cur != NULL)
return cur;
return NULL;
}
/**
* sysfs_open_device: 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 unsigned char *path)
{
struct sysfs_device *dev = NULL;
struct sysfs_directory *sdir = NULL;
if (path == NULL) {
errno = EINVAL;
return NULL;
}
dev = alloc_device();
if (dev == NULL) {
dprintf("Error allocating device at %s\n", path);
return NULL;
}
sdir = sysfs_open_directory(path);
if (sdir == NULL) {
dprintf("Invalid device at %s\n", path);
errno = EINVAL;
sysfs_close_device(dev);
return NULL;
}
if ((sysfs_read_directory(sdir)) != 0) {
dprintf("Error reading device directory at %s\n", path);
sysfs_close_directory(sdir);
sysfs_close_device(dev);
return NULL;
}
dev->directory = sdir;
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);
if (get_device_bus(dev) != 0)
strcpy(dev->bus, SYSFS_UNKNOWN);
return dev;
}
/**
* 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.
*/
static struct sysfs_device *sysfs_open_device_tree(const unsigned char *path)
{
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);
}
}
return rootdev;
}
/**
* sysfs_close_root_device: closes root and all devices
* @root: root device to close
*/
void sysfs_close_root_device(struct sysfs_root_device *root)
{
if (root != NULL) {
if (root->devices != NULL)
dlist_destroy(root->devices);
if (root->directory != NULL)
sysfs_close_directory(root->directory);
free(root);
}
}
/**
* 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
*/
static struct sysfs_directory *open_root_device_dir(const unsigned char *name)
{
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;
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;
}
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);
}
/**
* 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_NAME_LEN];
if (device == NULL || path == NULL) {
errno = EINVAL;
return -1;
}
memset(bus_path, 0, SYSFS_NAME_LEN);
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);
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_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];
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(sysfs_path);
if (device == NULL) {
dprintf("Error opening device %s\n", bus_id);
return NULL;
}
return device;
}
/*
* 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;
}