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Sourcecode: udev version File versions

sysfs_driver.c

/*
 * sysfs_driver.c
 *
 * Driver utility functions for libsysfs
 *
 * Copyright (C) IBM Corp. 2003-2005
 *
 *  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 void sysfs_close_driver_device(void *device)
{
      sysfs_close_device((struct sysfs_device *)device);
}

/**
 * sysfs_close_driver: closes driver and deletes device lists too
 * @driver: driver to close
 */
void sysfs_close_driver(struct sysfs_driver *driver)
{
      if (driver) {
            if (driver->devices) 
                  dlist_destroy(driver->devices);
            if (driver->attrlist)
                  dlist_destroy(driver->attrlist);
            free(driver);
      }
}

/**
 * alloc_driver: allocates and initializes driver
 * returns struct sysfs_driver with success and NULL with error.
 */
static struct sysfs_driver *alloc_driver(void)
{
      return (struct sysfs_driver *)calloc(1, sizeof(struct sysfs_driver));
}

/**
 * get_driver_bus: gets bus the driver is on
 * Returns 0 on success and 1 on error
 */
static int get_driver_bus(struct sysfs_driver *drv)
{
      char drvpath[SYSFS_PATH_MAX], *c = NULL;
      
      if (!drv) {
            errno = EINVAL;
            return 1;
      }

      safestrcpy(drvpath, drv->path);
      c = strstr(drvpath, SYSFS_DRIVERS_NAME);
      if (c == NULL)
            return 1;
      *--c = '\0';
      c = strstr(drvpath, SYSFS_BUS_NAME);
      if (c == NULL)
            return 1;
      c = strstr(c, "/");
      if (c == NULL)
            return 1;
      c++;
      safestrcpy(drv->bus, c);
      return 0;
}

/**
 * sysfs_get_driver_attr: searches drv's attributes by name
 * @drv: driver to look through
 * @name: attribute name to get
 * returns sysfs_attribute reference with success or NULL with error.
 */
struct sysfs_attribute *sysfs_get_driver_attr(struct sysfs_driver *drv,
                                    const char *name)
{
      if (!drv || !name) {
            errno = EINVAL;
            return NULL;
      }
      return get_attribute(drv, (char *)name);
}

/**
 * sysfs_get_driver_attributes: gets list of driver attributes
 * @dev: driver whose attributes list is needed
 * returns dlist of attributes on success or NULL on error
 */
struct dlist *sysfs_get_driver_attributes(struct sysfs_driver *drv)
{
      if (!drv) {
            errno = EINVAL;
            return NULL;
      }
      return get_attributes_list(drv);
}

/**
 * sysfs_open_driver_path: opens and initializes driver structure
 * @path: path to driver directory
 * returns struct sysfs_driver with success and NULL with error
 */
struct sysfs_driver *sysfs_open_driver_path(const char *path)
{
      struct sysfs_driver *driver = NULL;

      if (!path) {
            errno = EINVAL;
            return NULL;
      }
      if (sysfs_path_is_dir(path)) {
            dprintf("Invalid path to driver: %s\n", path);
            return NULL;
      }
      driver = alloc_driver();
      if (!driver) {
            dprintf("Error allocating driver at %s\n", path);
            return NULL;
      }
      if (sysfs_get_name_from_path(path, driver->name, SYSFS_NAME_LEN)) {
            dprintf("Error getting driver name from path\n");
            free(driver);
            return NULL;
      }
      safestrcpy(driver->path, path);
      if (sysfs_remove_trailing_slash(driver->path)) {
            dprintf("Invalid path to driver %s\n", driver->path);
            sysfs_close_driver(driver);
            return NULL;
      }
      if (get_driver_bus(driver)) {
            dprintf("Could not get the bus driver is on\n");
            sysfs_close_driver(driver);
            return NULL;
      }

      return driver;
}

/**
 * get_driver_path: looks up the bus the driver is on and builds path to
 *          the driver.
 * @bus: bus on which to search
 * @drv: driver to look for
 * @path: buffer to return path to driver
 * @psize: size of "path"
 * Returns 0 on success and -1 on error
 */
static int get_driver_path(const char *bus, const char *drv, 
                  char *path, size_t psize)
{
      if (!bus || !drv || !path || psize == 0) {
            errno = EINVAL;
            return -1;
      }
      if (sysfs_get_mnt_path(path, psize)) {
            dprintf("Error getting sysfs mount path\n");
            return -1;
      }
      safestrcatmax(path, "/", psize);
      safestrcatmax(path, SYSFS_BUS_NAME, psize);
      safestrcatmax(path, "/", psize);
      safestrcatmax(path, bus, psize);
      safestrcatmax(path, "/", psize);
      safestrcatmax(path, SYSFS_DRIVERS_NAME, psize);
      safestrcatmax(path, "/", psize);
      safestrcatmax(path, drv, psize);
      return 0;
}

/**
 * sysfs_open_driver: open driver by name, given its bus
 * @bus_name: Name of the bus
 * @drv_name: Name of the driver
 * Returns the sysfs_driver reference on success and NULL on failure
 */
struct sysfs_driver *sysfs_open_driver(const char *bus_name, 
                  const char *drv_name)
{
      char path[SYSFS_PATH_MAX];
      struct sysfs_driver *driver = NULL;

      if (!drv_name || !bus_name) {
            errno = EINVAL;
            return NULL;
      }

      memset(path, 0, SYSFS_PATH_MAX);
      if (get_driver_path(bus_name, drv_name, path, SYSFS_PATH_MAX)) {
            dprintf("Error getting to driver %s\n", drv_name);
            return NULL;
      }
      driver = sysfs_open_driver_path(path);
      if (!driver) {
            dprintf("Error opening driver at %s\n", path);
            return NULL;
      }
      return driver;
}

/**
 * sysfs_get_driver_devices: gets list of devices that use the driver
 * @drv: sysfs_driver whose device list is needed
 * Returns dlist of struct sysfs_device on success and NULL on failure
 */
struct dlist *sysfs_get_driver_devices(struct sysfs_driver *drv)
{
      char *ln = NULL;
      struct dlist *linklist = NULL;
      struct sysfs_device *dev = NULL;

      if (!drv) {
            errno = EINVAL;
            return NULL;
      }

      linklist = read_dir_links(drv->path);
      if (linklist) {
            dlist_for_each_data(linklist, ln, char) {
                  
                  if (!strncmp(ln, SYSFS_MODULE_NAME, strlen(ln)))
                        continue;

                  dev = sysfs_open_device(drv->bus, ln);
                  if (!dev) {
                        dprintf("Error opening driver's device\n");
                        sysfs_close_list(linklist);
                        return NULL;
                  }
                  if (!drv->devices) {
                        drv->devices = dlist_new_with_delete
                              (sizeof(struct sysfs_device),
                               sysfs_close_driver_device);
                        if (!drv->devices) {
                              dprintf("Error creating device list\n");
                              sysfs_close_list(linklist);
                              return NULL;
                        }
                  }
                  dlist_unshift_sorted(drv->devices, dev, sort_list);
            }
            sysfs_close_list(linklist);
      }
      return drv->devices;
}

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