libudev-enumerate.c revision 438d4c3cd4b89381348f84ef9f8b8937814f8362
/*
* libudev - interface to udev device information
*
* Copyright (C) 2008 Kay Sievers <kay.sievers@vrfy.org>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <dirent.h>
#include <sys/stat.h>
#include "libudev.h"
#include "libudev-private.h"
struct udev_enumerate {
struct udev *udev;
int refcount;
struct list_node devices_list;
};
struct udev_enumerate *udev_enumerate_ref(struct udev_enumerate *udev_enumerate)
{
if (udev_enumerate == NULL)
return NULL;
udev_enumerate->refcount++;
return udev_enumerate;
}
void udev_enumerate_unref(struct udev_enumerate *udev_enumerate)
{
if (udev_enumerate == NULL)
return;
udev_enumerate->refcount--;
if (udev_enumerate->refcount > 0)
return;
list_cleanup(udev_enumerate->udev, &udev_enumerate->devices_list);
free(udev_enumerate);
}
struct udev *udev_enumerate_get_udev(struct udev_enumerate *udev_enumerate)
{
if (udev_enumerate == NULL)
return NULL;
return udev_enumerate->udev;
}
struct udev_list_entry *udev_enumerate_get_list_entry(struct udev_enumerate *udev_enumerate)
{
if (udev_enumerate == NULL)
return NULL;
return list_get_entry(&udev_enumerate->devices_list);
}
static int devices_scan_subsystem(struct udev *udev,
const char *basedir, const char *subsystem, const char *subdir,
struct list_node *devices_list)
{
char path[UTIL_PATH_SIZE];
DIR *dir;
struct dirent *dent;
util_strlcpy(path, udev_get_sys_path(udev), sizeof(path));
util_strlcat(path, basedir, sizeof(path));
if (subsystem != NULL) {
util_strlcat(path, "/", sizeof(path));
util_strlcat(path, subsystem, sizeof(path));
}
if (subdir != NULL)
util_strlcat(path, subdir, sizeof(path));
dir = opendir(path);
if (dir == NULL)
return -1;
for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
char syspath[UTIL_PATH_SIZE];
char filename[UTIL_PATH_SIZE];
struct stat statbuf;
if (dent->d_name[0] == '.')
continue;
util_strlcpy(syspath, path, sizeof(syspath));
util_strlcat(syspath, "/", sizeof(syspath));
util_strlcat(syspath, dent->d_name, sizeof(syspath));
util_strlcpy(filename, syspath, sizeof(filename));
util_strlcat(filename, "/uevent", sizeof(filename));
if (stat(filename, &statbuf) != 0)
continue;
util_resolve_sys_link(udev, syspath, sizeof(syspath));
list_entry_add(udev, devices_list, syspath, NULL, 1, 1);
}
closedir(dir);
return 0;
}
static int devices_scan_subsystems(struct udev *udev,
const char *basedir, const char *subdir,
struct udev_list_entry *subsystem_include_list,
struct udev_list_entry *subsystem_exclude_list,
struct list_node *devices_list)
{
if (subsystem_include_list != NULL) {
struct udev_list_entry *list_entry;
/* if list of subsystems to scan is given, just use this list */
udev_list_entry_foreach(list_entry, subsystem_include_list) {
if (udev_list_entry_get_by_name(subsystem_exclude_list, udev_list_entry_get_name(list_entry)) != NULL)
continue;
devices_scan_subsystem(udev, basedir, udev_list_entry_get_name(list_entry), subdir, devices_list);
}
} else {
char path[UTIL_PATH_SIZE];
DIR *dir;
struct dirent *dent;
/* if no list of subsystems to scan is given, scan all, and possible exclude some subsystems */
util_strlcpy(path, udev_get_sys_path(udev), sizeof(path));
util_strlcat(path, basedir, sizeof(path));
dir = opendir(path);
if (dir == NULL)
return -1;
for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
if (dent->d_name[0] == '.')
continue;
if (udev_list_entry_get_by_name(subsystem_exclude_list, dent->d_name) != NULL)
continue;
devices_scan_subsystem(udev, basedir, dent->d_name, subdir, devices_list);
}
closedir(dir);
}
return 0;
}
static int devices_delay(struct udev *udev, const char *syspath)
{
static const char *delay_device_list[] = {
"/block/md",
"/block/dm-",
NULL
};
size_t len;
int i;
len = strlen(udev_get_sys_path(udev));
for (i = 0; delay_device_list[i] != NULL; i++) {
if (strstr(&syspath[len], delay_device_list[i]) != NULL) {
info(udev, "delaying: %s\n", syspath);
return 1;
}
}
return 0;
}
/**
* udev_enumerate_new:
* @udev: udev library context
*
* Returns: an enumeration context
**/
struct udev_enumerate *udev_enumerate_new(struct udev *udev)
{
struct udev_enumerate *udev_enumerate;
udev_enumerate = malloc(sizeof(struct udev_enumerate));
if (udev_enumerate == NULL)
return NULL;
memset(udev_enumerate, 0x00, (sizeof(struct udev_enumerate)));
udev_enumerate->refcount = 1;
udev_enumerate->udev = udev;
list_init(&udev_enumerate->devices_list);
return udev_enumerate;
}
/**
* udev_enumerate_scan_devices:
* @udev_enumerate: udev enumeration context
* @subsystem: the list of names of subsystems to look for devices
*
* Returns: 0 on success.
**/
int udev_enumerate_scan_devices(struct udev_enumerate *udev_enumerate, const char *subsystem, ...)
{
struct udev *udev = udev_enumerate_get_udev(udev_enumerate);
va_list vargs;
const char *arg;
char base[UTIL_PATH_SIZE];
struct stat statbuf;
struct list_node subsystem_include_list;
struct list_node subsystem_exclude_list;
struct udev_list_entry *list_entry;
if (udev_enumerate == NULL)
return -EINVAL;
va_start(vargs, subsystem);
list_init(&subsystem_include_list);
list_init(&subsystem_exclude_list);
for (arg = subsystem; arg != NULL; arg = va_arg(vargs, const char *)) {
if (arg[0] != '!')
list_entry_add(udev, &subsystem_include_list, arg, NULL, 1, 0);
else
list_entry_add(udev, &subsystem_exclude_list, &arg[1], NULL, 1, 0);
}
va_end(vargs);
util_strlcpy(base, udev_get_sys_path(udev), sizeof(base));
util_strlcat(base, "/subsystem", sizeof(base));
if (stat(base, &statbuf) == 0) {
/* we have /subsystem/, forget all the old stuff */
info(udev, "searching '/subsystem/*/devices/*' dir\n");
devices_scan_subsystems(udev, "/subsystem", "/devices",
list_get_entry(&subsystem_include_list),
list_get_entry(&subsystem_exclude_list),
&udev_enumerate->devices_list);
} else {
info(udev, "searching '/bus/*/devices/*' dir\n");
devices_scan_subsystems(udev, "/bus", "/devices",
list_get_entry(&subsystem_include_list),
list_get_entry(&subsystem_exclude_list),
&udev_enumerate->devices_list);
info(udev, "searching '/class/*' dir\n");
devices_scan_subsystems(udev, "/class", NULL,
list_get_entry(&subsystem_include_list),
list_get_entry(&subsystem_exclude_list),
&udev_enumerate->devices_list);
/* if block isn't a class, scan /block/ */
util_strlcpy(base, udev_get_sys_path(udev), sizeof(base));
util_strlcat(base, "/class/block", sizeof(base));
if (stat(base, &statbuf) != 0) {
struct udev_list_entry *include_list = list_get_entry(&subsystem_include_list);
struct udev_list_entry *exclude_list = list_get_entry(&subsystem_exclude_list);
int include_block = (include_list == NULL || udev_list_entry_get_by_name(include_list, "block") != NULL);
int exclude_block = (udev_list_entry_get_by_name(exclude_list, "block") != NULL);
if (include_block && !exclude_block) {
info(udev, "searching '/block/*' dir\n");
/* scan disks */
devices_scan_subsystem(udev, "/block", NULL, NULL, &udev_enumerate->devices_list);
/* scan partitions */
info(udev, "searching '/block/*/*' dir\n");
devices_scan_subsystems(udev, "/block", NULL,
NULL, NULL,
&udev_enumerate->devices_list);
}
}
}
list_cleanup(udev, &subsystem_include_list);
list_cleanup(udev, &subsystem_exclude_list);
/* sort delayed devices to the end of the list */
udev_list_entry_foreach(list_entry, list_get_entry(&udev_enumerate->devices_list)) {
if (devices_delay(udev, udev_list_entry_get_name(list_entry)))
list_entry_move_to_end(list_entry);
}
return 0;
}
/**
* udev_enumerate_scan_subsystems:
* @udev_enumerate: udev enumeration context
*
* Returns: 0 on success.
**/
int udev_enumerate_scan_subsystems(struct udev_enumerate *udev_enumerate)
{
struct udev *udev = udev_enumerate_get_udev(udev_enumerate);
char base[UTIL_PATH_SIZE];
struct stat statbuf;
const char *subsysdir;
if (udev_enumerate == NULL)
return -EINVAL;
util_strlcpy(base, udev_get_sys_path(udev), sizeof(base));
util_strlcat(base, "/subsystem", sizeof(base));
if (stat(base, &statbuf) == 0)
subsysdir = "/subsystem";
else
subsysdir = "/bus";
info(udev, "searching '%s/*' dir\n", subsysdir);
devices_scan_subsystem(udev, subsysdir, NULL, NULL, &udev_enumerate->devices_list);
info(udev, "searching '%s/*/drivers/*' dir\n", subsysdir);
devices_scan_subsystems(udev, subsysdir, "/drivers",
NULL, NULL,
&udev_enumerate->devices_list);
return 0;
}