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bcbe2d8e7d
Ananth released sysfsutils 0.4.0 last night, I'm sure you saw the email. Here's a patch with the latest changes from the pre-patch I already gave you. It includes sysfs_get_device_parent(), which you said you needed. I've run your test scripts and I've built scsi_id. Please play around with this and check it out. There are quite a few changes. Please do not access structure pointers, like sysfs_device's parent, directly like dev->parent. Please use the "get" function to retrieve. The functions load things on demand and refresh views under the covers.
596 lines
15 KiB
C
596 lines
15 KiB
C
/*
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* sysfs_device.c
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*
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* Generic device utility functions for libsysfs
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*
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* Copyright (C) IBM Corp. 2003
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*
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*/
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#include "libsysfs.h"
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#include "sysfs.h"
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/**
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* get_device_bus: retrieves the bus name the device is on, checks path to
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* bus' link to make sure it has correct device.
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* @dev: device to get busname.
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* returns 0 with success and -1 with error.
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*/
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static int get_device_bus(struct sysfs_device *dev)
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{
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unsigned char subsys[SYSFS_NAME_LEN], path[SYSFS_PATH_MAX];
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unsigned char target[SYSFS_PATH_MAX], *bus = NULL, *c = NULL;
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struct dlist *buslist = NULL;
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if (dev == NULL) {
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errno = EINVAL;
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return -1;
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}
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memset(subsys, 0, SYSFS_NAME_LEN);
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strcat(subsys, "/");
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strcpy(subsys, SYSFS_BUS_NAME); /* subsys = /bus */
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buslist = sysfs_open_subsystem_list(subsys);
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if (buslist != NULL) {
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dlist_for_each_data(buslist, bus, char) {
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memset(path, 0, SYSFS_PATH_MAX);
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strcpy(path, dev->path);
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c = strstr(path, "/devices");
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if (c == NULL) {
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dprintf("Invalid path to device %s\n", path);
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sysfs_close_list(buslist);
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return -1;
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}
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*c = '\0';
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strcat(path, "/");
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strcat(path, SYSFS_BUS_NAME);
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strcat(path, "/");
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strcat(path, bus);
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strcat(path, "/");
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strcat(path, SYSFS_DEVICES_NAME);
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strcat(path, "/");
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strcat(path, dev->bus_id);
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if ((sysfs_path_is_link(path)) == 0) {
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memset(target, 0, SYSFS_PATH_MAX);
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if ((sysfs_get_link(path, target,
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SYSFS_PATH_MAX)) != 0) {
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dprintf("Error getting link target\n");
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sysfs_close_list(buslist);
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return -1;
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}
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if (!(strncmp(target, dev->path,
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SYSFS_PATH_MAX))) {
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strcpy(dev->bus, bus);
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sysfs_close_list(buslist);
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return 0;
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}
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}
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}
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sysfs_close_list(buslist);
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}
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return -1;
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}
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/**
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* sysfs_close_device_tree: closes every device in the supplied tree,
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* closing children only.
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* @devroot: device root of tree.
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*/
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static void sysfs_close_device_tree(struct sysfs_device *devroot)
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{
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if (devroot != NULL) {
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if (devroot->children != NULL) {
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struct sysfs_device *child = NULL;
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dlist_for_each_data(devroot->children, child,
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struct sysfs_device) {
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sysfs_close_device_tree(child);
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}
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}
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sysfs_close_device(devroot);
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}
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}
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/**
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* sysfs_close_dev_tree: routine for dlist integration
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*/
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static void sysfs_close_dev_tree(void *dev)
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{
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sysfs_close_device_tree((struct sysfs_device *)dev);
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}
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/**
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* sysfs_close_device: closes and cleans up a device
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* @dev = device to clean up
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*/
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void sysfs_close_device(struct sysfs_device *dev)
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{
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if (dev != NULL) {
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if (dev->parent != NULL)
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sysfs_close_device(dev->parent);
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if (dev->directory != NULL)
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sysfs_close_directory(dev->directory);
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if (dev->children != NULL && dev->children->count == 0)
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dlist_destroy(dev->children);
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free(dev);
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}
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}
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/**
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* alloc_device: allocates and initializes device structure
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* returns struct sysfs_device
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*/
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static struct sysfs_device *alloc_device(void)
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{
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return (struct sysfs_device *)calloc(1, sizeof(struct sysfs_device));
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}
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/**
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* open_device_dir: opens up sysfs_directory for specific root dev
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* @name: name of root
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* returns struct sysfs_directory with success and NULL with error
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*/
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static struct sysfs_directory *open_device_dir(const unsigned char *path)
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{
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struct sysfs_directory *rdir = NULL;
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if (path == NULL) {
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errno = EINVAL;
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return NULL;
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}
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rdir = sysfs_open_directory(path);
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if (rdir == NULL) {
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errno = EINVAL;
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dprintf ("Device %s not supported on this system\n", path);
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return NULL;
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}
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if ((sysfs_read_dir_subdirs(rdir)) != 0) {
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dprintf ("Error reading device at dir %s\n", path);
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sysfs_close_directory(rdir);
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return NULL;
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}
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return rdir;
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}
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/**
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* sysfs_open_device_path: opens and populates device structure
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* @path: path to device, this is the /sys/devices/ path
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* returns sysfs_device structure with success or NULL with error
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*/
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struct sysfs_device *sysfs_open_device_path(const unsigned char *path)
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{
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struct sysfs_device *dev = NULL;
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if (path == NULL) {
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errno = EINVAL;
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return NULL;
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}
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if ((sysfs_path_is_dir(path)) != 0) {
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dprintf("Incorrect path to device: %s\n", path);
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return NULL;
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}
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dev = alloc_device();
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if (dev == NULL) {
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dprintf("Error allocating device at %s\n", path);
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return NULL;
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}
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if ((sysfs_get_name_from_path(path, dev->bus_id,
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SYSFS_NAME_LEN)) != 0) {
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errno = EINVAL;
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dprintf("Error getting device bus_id\n");
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sysfs_close_device(dev);
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return NULL;
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}
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strcpy(dev->path, path);
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/*
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* The "name" attribute no longer exists... return the device's
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* sysfs representation instead, in the "dev->name" field, which
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* implies that the dev->name and dev->bus_id contain same data.
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*/
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strncpy(dev->name, dev->bus_id, SYSFS_NAME_LEN);
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if (get_device_bus(dev) != 0)
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strcpy(dev->bus, SYSFS_UNKNOWN);
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return dev;
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}
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/**
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* sysfs_open_device_tree: opens root device and all of its children,
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* creating a tree of devices. Only opens children.
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* @path: sysfs path to devices
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* returns struct sysfs_device and its children with success or NULL with
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* error.
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*/
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static struct sysfs_device *sysfs_open_device_tree(const unsigned char *path)
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{
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struct sysfs_device *rootdev = NULL, *new = NULL;
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struct sysfs_directory *cur = NULL;
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if (path == NULL) {
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errno = EINVAL;
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return NULL;
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}
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rootdev = sysfs_open_device_path(path);
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if (rootdev == NULL) {
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dprintf("Error opening root device at %s\n", path);
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return NULL;
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}
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if (rootdev->directory == NULL) {
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rootdev->directory = open_device_dir(rootdev->path);
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if (rootdev->directory == NULL)
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return NULL;
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}
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if (rootdev->directory->subdirs != NULL) {
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dlist_for_each_data(rootdev->directory->subdirs, cur,
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struct sysfs_directory) {
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new = sysfs_open_device_tree(cur->path);
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if (new == NULL) {
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dprintf("Error opening device tree at %s\n",
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cur->path);
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sysfs_close_device_tree(rootdev);
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return NULL;
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}
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if (rootdev->children == NULL)
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rootdev->children = dlist_new_with_delete
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(sizeof(struct sysfs_device),
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sysfs_close_dev_tree);
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dlist_unshift(rootdev->children, new);
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}
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}
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return rootdev;
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}
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/**
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* sysfs_close_root_device: closes root and all devices
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* @root: root device to close
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*/
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void sysfs_close_root_device(struct sysfs_root_device *root)
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{
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if (root != NULL) {
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if (root->devices != NULL)
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dlist_destroy(root->devices);
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if (root->directory != NULL)
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sysfs_close_directory(root->directory);
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free(root);
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}
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}
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/**
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* sysfs_get_root_devices: opens up all the devices under this root device
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* @root: root device to open devices for
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* returns dlist of devices with success and NULL with error
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*/
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struct dlist *sysfs_get_root_devices(struct sysfs_root_device *root)
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{
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struct sysfs_device *dev = NULL;
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struct sysfs_directory *cur = NULL;
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if (root == NULL) {
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errno = EINVAL;
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return NULL;
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}
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if (root->directory == NULL) {
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root->directory = open_device_dir(root->path);
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if (root->directory == NULL)
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return NULL;
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}
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if (root->directory->subdirs == NULL)
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return 0;
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dlist_for_each_data(root->directory->subdirs, cur,
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struct sysfs_directory) {
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dev = sysfs_open_device_tree(cur->path);
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if (dev == NULL) {
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dprintf ("Error opening device at %s\n", cur->path);
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continue;
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}
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if (root->devices == NULL)
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root->devices = dlist_new_with_delete
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(sizeof(struct sysfs_device),
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sysfs_close_dev_tree);
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dlist_unshift(root->devices, dev);
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}
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return root->devices;
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}
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/**
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* sysfs_open_root_device: opens sysfs devices root and all of its
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* devices.
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* @name: name of /sys/devices/root to open
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* returns struct sysfs_root_device if success and NULL with error
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*/
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struct sysfs_root_device *sysfs_open_root_device(const unsigned char *name)
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{
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struct sysfs_root_device *root = NULL;
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unsigned char rootpath[SYSFS_PATH_MAX];
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if (name == NULL) {
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errno = EINVAL;
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return NULL;
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}
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memset(rootpath, 0, SYSFS_PATH_MAX);
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if (sysfs_get_mnt_path(rootpath, SYSFS_PATH_MAX) != 0) {
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dprintf ("Sysfs not supported on this system\n");
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return NULL;
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}
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if (sysfs_trailing_slash(rootpath) == 0)
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strcat(rootpath, "/");
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strcat(rootpath, SYSFS_DEVICES_NAME);
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strcat(rootpath, "/");
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strcat(rootpath, name);
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if ((sysfs_path_is_dir(rootpath)) != 0) {
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errno = EINVAL;
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dprintf("Invalid root device: %s\n", name);
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return NULL;
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}
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root = (struct sysfs_root_device *)calloc
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(1, sizeof(struct sysfs_root_device));
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if (root == NULL) {
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dprintf("calloc failure\n");
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return NULL;
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}
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strcpy(root->name, name);
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strcpy(root->path, rootpath);
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return root;
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}
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/**
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* sysfs_get_device_attributes: returns a dlist of attributes corresponding to
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* the specific device
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* @device: struct sysfs_device * for which attributes are to be returned
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*/
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struct dlist *sysfs_get_device_attributes(struct sysfs_device *device)
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{
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if (device == NULL)
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return NULL;
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if (device->directory == NULL) {
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device->directory = sysfs_open_directory(device->path);
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if (device->directory == NULL)
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return NULL;
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}
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if (device->directory->attributes == NULL) {
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if ((sysfs_read_dir_attributes(device->directory)) != 0)
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return NULL;
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} else {
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if ((sysfs_path_is_dir(device->path)) != 0) {
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dprintf("Device at %s no longer exists", device->path);
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return NULL;
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}
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if ((sysfs_refresh_attributes
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(device->directory->attributes)) != 0) {
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dprintf("Error refreshing device attributes\n");
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return NULL;
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}
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}
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return (device->directory->attributes);
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}
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/**
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* sysfs_get_device_attr: searches dev's attributes by name
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* @dev: device to look through
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* @name: attribute name to get
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* returns sysfs_attribute reference with success or NULL with error.
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*/
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struct sysfs_attribute *sysfs_get_device_attr(struct sysfs_device *dev,
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const unsigned char *name)
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{
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struct sysfs_attribute *cur = NULL;
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struct dlist *attrlist = NULL;
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if (dev == NULL || name == NULL) {
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errno = EINVAL;
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return NULL;
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}
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attrlist = sysfs_get_device_attributes(dev);
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if (attrlist == NULL)
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return NULL;
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cur = sysfs_get_directory_attribute(dev->directory,
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(unsigned char *)name);
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return cur;
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}
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/**
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* get_device_absolute_path: looks up the bus the device is on, gets
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* absolute path to the device
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* @device: device for which path is needed
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* @path: buffer to store absolute path
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* @psize: size of "path"
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* Returns 0 on success -1 on failure
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*/
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static int get_device_absolute_path(const unsigned char *device,
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const unsigned char *bus, unsigned char *path, size_t psize)
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{
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unsigned char bus_path[SYSFS_PATH_MAX];
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if (device == NULL || path == NULL) {
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errno = EINVAL;
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return -1;
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}
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memset(bus_path, 0, SYSFS_PATH_MAX);
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if (sysfs_get_mnt_path(bus_path, SYSFS_PATH_MAX) != 0) {
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dprintf ("Sysfs not supported on this system\n");
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return -1;
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}
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if (sysfs_trailing_slash(bus_path) == 0)
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strcat(bus_path, "/");
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strcat(bus_path, SYSFS_BUS_NAME);
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strcat(bus_path, "/");
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strcat(bus_path, bus);
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strcat(bus_path, "/");
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strcat(bus_path, SYSFS_DEVICES_NAME);
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strcat(bus_path, "/");
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strcat(bus_path, device);
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/*
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* We now are at /sys/bus/"bus_name"/devices/"device" which is a link.
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* Now read this link to reach to the device.
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*/
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if ((sysfs_get_link(bus_path, path, SYSFS_PATH_MAX)) != 0) {
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dprintf("Error getting to device %s\n", device);
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return -1;
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}
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return 0;
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}
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/**
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* sysfs_open_device: open a device by id (use the "bus" subsystem)
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* @bus_id: bus_id of the device to open - has to be the "bus_id" in
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* /sys/bus/xxx/devices
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* @bus: bus the device belongs to
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* returns struct sysfs_device if found, NULL otherwise
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* NOTE:
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* 1. Use sysfs_close_device to close the device
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* 2. Bus the device is on must be supplied
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* Use sysfs_find_device_bus to get the bus name
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*/
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struct sysfs_device *sysfs_open_device(const unsigned char *bus_id,
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const unsigned char *bus)
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{
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char sysfs_path[SYSFS_PATH_MAX];
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struct sysfs_device *device = NULL;
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if (bus_id == NULL || bus == NULL) {
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errno = EINVAL;
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return NULL;
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}
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memset(sysfs_path, 0, SYSFS_PATH_MAX);
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if ((get_device_absolute_path(bus_id, bus, sysfs_path,
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SYSFS_PATH_MAX)) != 0) {
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dprintf("Error getting to device %s\n", bus_id);
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return NULL;
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}
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device = sysfs_open_device_path(sysfs_path);
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if (device == NULL) {
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dprintf("Error opening device %s\n", bus_id);
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return NULL;
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}
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return device;
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}
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/**
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* sysfs_get_device_parent: opens up given device's parent and returns a
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* reference to its sysfs_device
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* @dev: sysfs_device whose parent is requested
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* Returns sysfs_device of the parent on success and NULL on failure
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*/
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struct sysfs_device *sysfs_get_device_parent(struct sysfs_device *dev)
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{
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unsigned char ppath[SYSFS_PATH_MAX], *tmp = NULL;
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if (dev == NULL) {
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errno = EINVAL;
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return NULL;
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}
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if (dev->parent != NULL)
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return (dev->parent);
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memset(ppath, 0, SYSFS_PATH_MAX);
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strcpy(ppath, dev->path);
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tmp = strrchr(ppath, '/');
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if (tmp == NULL) {
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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;
|
|
}
|
|
|