Systemd/libsysfs/sysfs_bus.c

428 lines
10 KiB
C

/*
* sysfs_bus.c
*
* Generic bus 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 void sysfs_close_dev(void *dev)
{
sysfs_close_device((struct sysfs_device *)dev);
}
static void sysfs_close_drv(void *drv)
{
sysfs_close_driver((struct sysfs_driver *)drv);
}
/*
* compares devices' bus ids.
* @a: device id looking for
* @b: sysfs_device comparing being compared
* returns 1 if a==b->bus_id or 0 not equal
*/
static int bus_device_id_equal(void *a, void *b)
{
if (a == NULL || b == NULL)
return 0;
if (strcmp(((unsigned char *)a), ((struct sysfs_device *)b)->bus_id)
== 0)
return 1;
return 0;
}
/*
* compares drivers' names.
* @a: driver name looking for
* @b: sysfs_driver comparing being compared
* returns 1 if a==b->name or 0 not equal
*/
static int bus_driver_name_equal(void *a, void *b)
{
if (a == NULL || b == NULL)
return 0;
if (strcmp(((unsigned char *)a), ((struct sysfs_driver *)b)->name) == 0)
return 1;
return 0;
}
/**
* sysfs_close_bus: close single bus
* @bus: bus structure
*/
void sysfs_close_bus(struct sysfs_bus *bus)
{
if (bus != NULL) {
if (bus->directory != NULL)
sysfs_close_directory(bus->directory);
if (bus->devices)
dlist_destroy(bus->devices);
if (bus->drivers)
dlist_destroy(bus->drivers);
free(bus);
}
}
/**
* alloc_bus: mallocs new bus structure
* returns sysfs_bus_bus struct or NULL
*/
static struct sysfs_bus *alloc_bus(void)
{
return (struct sysfs_bus *)calloc(1, sizeof(struct sysfs_bus));
}
/**
* sysfs_get_bus_devices: gets all devices for bus
* @bus: bus to get devices for
* returns dlist of devices with success and NULL with failure
*/
struct dlist *sysfs_get_bus_devices(struct sysfs_bus *bus)
{
struct sysfs_device *bdev = NULL;
struct sysfs_directory *devdir = NULL;
struct sysfs_link *curl = NULL;
unsigned char path[SYSFS_PATH_MAX];
if (bus == NULL) {
errno = EINVAL;
return NULL;
}
memset(path, 0, SYSFS_PATH_MAX);
strcpy(path, bus->path);
strcat(path, "/");
strcat(path, SYSFS_DEVICES_NAME);
devdir = sysfs_open_directory(path);
if (devdir == NULL)
return NULL;
if (sysfs_read_dir_links(devdir) != 0) {
sysfs_close_directory(devdir);
return NULL;
}
if (devdir->links != 0) {
dlist_for_each_data(devdir->links, curl, struct sysfs_link) {
bdev = sysfs_open_device_path(curl->target);
if (bdev == NULL) {
dprintf("Error opening device at %s\n",
curl->target);
continue;
}
if (bus->devices == NULL)
bus->devices = dlist_new_with_delete
(sizeof(struct sysfs_device),
sysfs_close_dev);
dlist_unshift(bus->devices, bdev);
}
}
sysfs_close_directory(devdir);
return (bus->devices);
}
/**
* sysfs_get_bus_drivers: get all pci drivers
* @bus: pci bus to add drivers to
* returns dlist of drivers with success and NULL with error
*/
struct dlist *sysfs_get_bus_drivers(struct sysfs_bus *bus)
{
struct sysfs_driver *driver = NULL;
struct sysfs_directory *drvdir = NULL;
struct sysfs_directory *cursub = NULL;
unsigned char path[SYSFS_PATH_MAX];
if (bus == NULL) {
errno = EINVAL;
return NULL;
}
memset(path, 0, SYSFS_PATH_MAX);
strcpy(path, bus->path);
strcat(path, "/");
strcat(path, SYSFS_DRIVERS_NAME);
drvdir = sysfs_open_directory(path);
if (drvdir == NULL)
return NULL;
if (sysfs_read_dir_subdirs(drvdir) != 0) {
sysfs_close_directory(drvdir);
return NULL;
}
if (drvdir->subdirs != NULL) {
dlist_for_each_data(drvdir->subdirs, cursub,
struct sysfs_directory) {
driver = sysfs_open_driver_path(cursub->path);
if (driver == NULL) {
dprintf("Error opening driver at %s\n",
cursub->path);
continue;
}
if (bus->drivers == NULL)
bus->drivers = dlist_new_with_delete
(sizeof(struct sysfs_driver),
sysfs_close_drv);
dlist_unshift(bus->drivers, driver);
}
}
sysfs_close_directory(drvdir);
return (bus->drivers);
}
/**
* sysfs_open_bus: opens specific bus and all its devices on system
* returns sysfs_bus structure with success or NULL with error.
*/
struct sysfs_bus *sysfs_open_bus(const unsigned char *name)
{
struct sysfs_bus *bus = NULL;
unsigned char buspath[SYSFS_PATH_MAX];
if (name == NULL) {
errno = EINVAL;
return NULL;
}
memset(buspath, 0, SYSFS_PATH_MAX);
if ((sysfs_get_mnt_path(buspath, SYSFS_PATH_MAX)) != 0) {
dprintf("Sysfs not supported on this system\n");
return NULL;
}
if (sysfs_trailing_slash(buspath) == 0)
strcat(buspath, "/");
strcat(buspath, SYSFS_BUS_NAME);
strcat(buspath, "/");
strcat(buspath, name);
if ((sysfs_path_is_dir(buspath)) != 0) {
dprintf("Invalid path to bus: %s\n", buspath);
return NULL;
}
bus = alloc_bus();
if (bus == NULL) {
dprintf("calloc failed\n");
return NULL;
}
strcpy(bus->name, name);
strcpy(bus->path, buspath);
return bus;
}
/**
* sysfs_get_bus_device: Get specific device on bus using device's id
* @bus: bus to find device on
* @id: bus_id for device
* returns struct sysfs_device reference or NULL if not found.
*/
struct sysfs_device *sysfs_get_bus_device(struct sysfs_bus *bus,
unsigned char *id)
{
if (bus == NULL || id == NULL) {
errno = EINVAL;
return NULL;
}
if (bus->devices == NULL) {
bus->devices = sysfs_get_bus_devices(bus);
if (bus->devices == NULL)
return NULL;
}
return (struct sysfs_device *)dlist_find_custom(bus->devices, id,
bus_device_id_equal);
}
/**
* sysfs_get_bus_driver: Get specific driver on bus using driver name
* @bus: bus to find driver on
* @drvname: name of driver
* returns struct sysfs_driver reference or NULL if not found.
*/
struct sysfs_driver *sysfs_get_bus_driver(struct sysfs_bus *bus,
unsigned char *drvname)
{
if (bus == NULL || drvname == NULL) {
errno = EINVAL;
return NULL;
}
if (bus->drivers == NULL) {
bus->drivers = sysfs_get_bus_drivers(bus);
if (bus->drivers == NULL)
return NULL;
}
return (struct sysfs_driver *)dlist_find_custom(bus->drivers, drvname,
bus_driver_name_equal);
}
/**
* sysfs_get_bus_attributes: returns bus' dlist of attributes
* @bus: bus to get attributes for.
* returns dlist of attributes or NULL if there aren't any.
*/
struct dlist *sysfs_get_bus_attributes(struct sysfs_bus *bus)
{
if (bus == NULL)
return NULL;
if (bus->directory == NULL) {
bus->directory = sysfs_open_directory(bus->path);
if (bus->directory == NULL)
return NULL;
}
if (bus->directory->attributes == NULL) {
if ((sysfs_read_dir_attributes(bus->directory)) != 0)
return NULL;
} else {
if ((sysfs_path_is_dir(bus->path)) != 0) {
dprintf("Bus at %s no longer exists\n", bus->path);
return NULL;
}
if ((sysfs_refresh_attributes
(bus->directory->attributes)) != 0) {
dprintf("Error refreshing bus attributes\n");
return NULL;
}
}
return bus->directory->attributes;
}
/**
* sysfs_get_bus_attribute: gets a specific bus attribute, if buses had
* attributes.
* @bus: bus to retrieve attribute from
* @attrname: attribute name to retrieve
* returns reference to sysfs_attribute if found or NULL if not found
*/
struct sysfs_attribute *sysfs_get_bus_attribute(struct sysfs_bus *bus,
unsigned char *attrname)
{
struct dlist *attrlist = NULL;
if (bus == NULL) {
errno = EINVAL;
return NULL;
}
attrlist = sysfs_get_bus_attributes(bus);
if (attrlist == NULL)
return NULL;
return sysfs_get_directory_attribute(bus->directory, attrname);
}
/**
* sysfs_open_bus_device: locates a device on a bus and returns it. Device
* must be closed using sysfs_close_device.
* @busname: Name of bus to search
* @dev_id: Id of device on bus.
* returns sysfs_device if found or NULL if not.
*/
struct sysfs_device *sysfs_open_bus_device(unsigned char *busname,
unsigned char *dev_id)
{
struct sysfs_device *rdev = NULL;
char path[SYSFS_PATH_MAX];
if (busname == NULL || dev_id == NULL) {
errno = EINVAL;
return NULL;
}
memset(path, 0, SYSFS_PATH_MAX);
if (sysfs_get_mnt_path(path, SYSFS_PATH_MAX) != 0) {
dprintf("Error getting sysfs mount point\n");
return NULL;
}
if (sysfs_trailing_slash(path) == 0)
strcat(path, "/");
strcat(path, SYSFS_BUS_NAME);
strcat(path, "/");
strcat(path, busname);
strcat(path, "/");
strcat(path, SYSFS_DEVICES_NAME);
strcat(path, "/");
strcat(path, dev_id);
rdev = sysfs_open_device_path(path);
if (rdev == NULL) {
dprintf("Error getting device %s on bus %s\n",
dev_id, busname);
return NULL;
}
return rdev;
}
/**
* sysfs_find_driver_bus: locates the bus the driver is on.
* @driver: name of the driver to locate
* @busname: buffer to copy name to
* @bsize: buffer size
* returns 0 with success, -1 with error
*/
int sysfs_find_driver_bus(const unsigned char *driver, unsigned char *busname,
size_t bsize)
{
unsigned char subsys[SYSFS_PATH_MAX], *bus = NULL, *curdrv = NULL;
struct dlist *buslist = NULL, *drivers = NULL;
if (driver == NULL || busname == NULL) {
errno = EINVAL;
return -1;
}
memset(subsys, 0, SYSFS_PATH_MAX);
strcat(subsys, "/");
strcpy(subsys, SYSFS_BUS_NAME);
buslist = sysfs_open_subsystem_list(subsys);
if (buslist != NULL) {
dlist_for_each_data(buslist, bus, char) {
memset(subsys, 0, SYSFS_PATH_MAX);
strcat(subsys, "/");
strcpy(subsys, SYSFS_BUS_NAME);
strcat(subsys, "/");
strcat(subsys, bus);
strcat(subsys, "/");
strcat(subsys, SYSFS_DRIVERS_NAME);
drivers = sysfs_open_subsystem_list(subsys);
if (drivers != NULL) {
dlist_for_each_data(drivers, curdrv, char) {
if (strcmp(driver, curdrv) == 0) {
strncpy(busname, bus, bsize);
sysfs_close_list(drivers);
sysfs_close_list(buslist);
return 0;
}
}
sysfs_close_list(drivers);
}
}
sysfs_close_list(buslist);
}
return -1;
}