libsysfs/sysfs_bus.c

   1 /*
   2  * sysfs_bus.c
   3  *
   4  * Generic bus utility functions for libsysfs
   5  *
   6  * Copyright (C) IBM Corp. 2003
   7  *
   8  *  This library is free software; you can redistribute it and/or
   9  *  modify it under the terms of the GNU Lesser General Public
  10  *  License as published by the Free Software Foundation; either
  11  *  version 2.1 of the License, or (at your option) any later version.
  12  *
  13  *  This library is distributed in the hope that it will be useful,
  14  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16  *  Lesser General Public License for more details.
  17  *
  18  *  You should have received a copy of the GNU Lesser General Public
  19  *  License along with this library; if not, write to the Free Software
  20  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  21  *
  22  */
  23 #include "libsysfs.h"
  24 #include "sysfs.h"
  25
  26 static void sysfs_close_dev(void *dev)
  27 {
  28         sysfs_close_device((struct sysfs_device *)dev);
  29 }
  30
  31 static void sysfs_close_drv(void *drv)
  32 {
  33         sysfs_close_driver((struct sysfs_driver *)drv);
  34 }
  35
  36 /*
  37  * compares devices' bus ids.
  38  * @a: device id looking for
  39  * @b: sysfs_device comparing being compared
  40  * returns 1 if a==b->bus_id or 0 not equal
  41  */
  42 static int bus_device_id_equal(void *a, void *b)
  43 {
  44         if (a == NULL || b == NULL)
  45                 return 0;
  46
  47         if (strcmp(((unsigned char *)a), ((struct sysfs_device *)b)->bus_id)
  48             == 0)
  49                 return 1;
  50         return 0;
  51 }
  52
  53 /*
  54  * compares drivers' names.
  55  * @a: driver name looking for
  56  * @b: sysfs_driver comparing being compared
  57  * returns 1 if a==b->name or 0 not equal
  58  */
  59 static int bus_driver_name_equal(void *a, void *b)
  60 {
  61         if (a == NULL || b == NULL)
  62                 return 0;
  63
  64         if (strcmp(((unsigned char *)a), ((struct sysfs_driver *)b)->name) == 0)
  65                 return 1;
  66         return 0;
  67 }
  68
  69 /**
  70  * sysfs_close_bus: close single bus
  71  * @bus: bus structure
  72  */
  73 void sysfs_close_bus(struct sysfs_bus *bus)
  74 {
  75         if (bus != NULL) {
  76                 if (bus->directory != NULL)
  77                         sysfs_close_directory(bus->directory);
  78                 if (bus->devices)
  79                         dlist_destroy(bus->devices);
  80                 if (bus->drivers)
  81                         dlist_destroy(bus->drivers);
  82                 free(bus);
  83         }
  84 }
  85
  86 /**
  87  * alloc_bus: mallocs new bus structure
  88  * returns sysfs_bus_bus struct or NULL
  89  */
  90 static struct sysfs_bus *alloc_bus(void)
  91 {
  92         return (struct sysfs_bus *)calloc(1, sizeof(struct sysfs_bus));
  93 }
  94
  95 /**
  96  * sysfs_get_bus_devices: gets all devices for bus
  97  * @bus: bus to get devices for
  98  * returns dlist of devices with success and NULL with failure
  99  */
 100 struct dlist *sysfs_get_bus_devices(struct sysfs_bus *bus)
 101 {
 102         struct sysfs_device *bdev = NULL;
 103         struct sysfs_directory *devdir = NULL;
 104         struct sysfs_link *curl = NULL;
 105         unsigned char path[SYSFS_PATH_MAX];
 106
 107         if (bus == NULL) {
 108                 errno = EINVAL;
 109                 return NULL;
 110         }
 111         memset(path, 0, SYSFS_PATH_MAX);
 112         strcpy(path, bus->path);
 113         strcat(path, "/");
 114         strcat(path, SYSFS_DEVICES_NAME);
 115         devdir = sysfs_open_directory(path);
 116         if (devdir == NULL)
 117                 return NULL;
 118
 119         if (sysfs_read_dir_links(devdir) != 0) {
 120                 sysfs_close_directory(devdir);
 121                 return NULL;
 122         }
 123
 124         if (devdir->links != 0) {
 125                 dlist_for_each_data(devdir->links, curl, struct sysfs_link) {
 126                         bdev = sysfs_open_device_path(curl->target);
 127                         if (bdev == NULL) {
 128                                 dprintf("Error opening device at %s\n",
 129                                                                 curl->target);
 130                                 continue;
 131                         }
 132                         if (bus->devices == NULL)
 133                                 bus->devices = dlist_new_with_delete
 134                                         (sizeof(struct sysfs_device),
 135                                                         sysfs_close_dev);
 136                         dlist_unshift(bus->devices, bdev);
 137                 }
 138         }
 139         sysfs_close_directory(devdir);
 140
 141         return (bus->devices);
 142 }
 143
 144 /**
 145  * sysfs_get_bus_drivers: get all pci drivers
 146  * @bus: pci bus to add drivers to
 147  * returns dlist of drivers with success and NULL with error
 148  */
 149 struct dlist *sysfs_get_bus_drivers(struct sysfs_bus *bus)
 150 {
 151         struct sysfs_driver *driver = NULL;
 152         struct sysfs_directory *drvdir = NULL;
 153         struct sysfs_directory *cursub = NULL;
 154         unsigned char path[SYSFS_PATH_MAX];
 155
 156         if (bus == NULL) {
 157                 errno = EINVAL;
 158                 return NULL;
 159         }
 160         memset(path, 0, SYSFS_PATH_MAX);
 161         strcpy(path, bus->path);
 162         strcat(path, "/");
 163         strcat(path, SYSFS_DRIVERS_NAME);
 164         drvdir = sysfs_open_directory(path);
 165         if (drvdir == NULL)
 166                 return NULL;
 167
 168         if (sysfs_read_dir_subdirs(drvdir) != 0) {
 169                 sysfs_close_directory(drvdir);
 170                 return NULL;
 171         }
 172         if (drvdir->subdirs != NULL) {
 173                 dlist_for_each_data(drvdir->subdirs, cursub,
 174                                                 struct sysfs_directory) {
 175                         driver = sysfs_open_driver_path(cursub->path);
 176                         if (driver == NULL) {
 177                                 dprintf("Error opening driver at %s\n",
 178                                                                 cursub->path);
 179                                 continue;
 180                         }
 181                         if (bus->drivers == NULL)
 182                                 bus->drivers = dlist_new_with_delete
 183                                         (sizeof(struct sysfs_driver),
 184                                                         sysfs_close_drv);
 185                         dlist_unshift(bus->drivers, driver);
 186                 }
 187         }
 188         sysfs_close_directory(drvdir);
 189         return (bus->drivers);
 190 }
 191
 192 /**
 193  * sysfs_open_bus: opens specific bus and all its devices on system
 194  * returns sysfs_bus structure with success or NULL with error.
 195  */
 196 struct sysfs_bus *sysfs_open_bus(const unsigned char *name)
 197 {
 198         struct sysfs_bus *bus = NULL;
 199         unsigned char buspath[SYSFS_PATH_MAX];
 200
 201         if (name == NULL) {
 202                 errno = EINVAL;
 203                 return NULL;
 204         }
 205
 206         memset(buspath, 0, SYSFS_PATH_MAX);
 207         if ((sysfs_get_mnt_path(buspath, SYSFS_PATH_MAX)) != 0) {
 208                 dprintf("Sysfs not supported on this system\n");
 209                 return NULL;
 210         }
 211
 212         strcat(buspath, "/");
 213         strcat(buspath, SYSFS_BUS_NAME);
 214         strcat(buspath, "/");
 215         strcat(buspath, name);
 216         if ((sysfs_path_is_dir(buspath)) != 0) {
 217                 dprintf("Invalid path to bus: %s\n", buspath);
 218                 return NULL;
 219         }
 220         bus = alloc_bus();
 221         if (bus == NULL) {
 222                 dprintf("calloc failed\n");
 223                 return NULL;
 224         }
 225         strcpy(bus->name, name);
 226         strcpy(bus->path, buspath);
 227         if ((sysfs_remove_trailing_slash(bus->path)) != 0) {
 228                 dprintf("Incorrect path to bus %s\n", bus->path);
 229                 sysfs_close_bus(bus);
 230                 return NULL;
 231         }
 232
 233         return bus;
 234 }
 235
 236 /**
 237  * sysfs_get_bus_device: Get specific device on bus using device's id
 238  * @bus: bus to find device on
 239  * @id: bus_id for device
 240  * returns struct sysfs_device reference or NULL if not found.
 241  */
 242 struct sysfs_device *sysfs_get_bus_device(struct sysfs_bus *bus,
 243                                                         unsigned char *id)
 244 {
 245         if (bus == NULL || id == NULL) {
 246                 errno = EINVAL;
 247                 return NULL;
 248         }
 249
 250         if (bus->devices == NULL) {
 251                 bus->devices = sysfs_get_bus_devices(bus);
 252                 if (bus->devices == NULL)
 253                         return NULL;
 254         }
 255
 256         return (struct sysfs_device *)dlist_find_custom(bus->devices, id,
 257                 bus_device_id_equal);
 258 }
 259
 260 /**
 261  * sysfs_get_bus_driver: Get specific driver on bus using driver name
 262  * @bus: bus to find driver on
 263  * @drvname: name of driver
 264  * returns struct sysfs_driver reference or NULL if not found.
 265  */
 266 struct sysfs_driver *sysfs_get_bus_driver(struct sysfs_bus *bus,
 267                                                         unsigned char *drvname)
 268 {
 269         if (bus == NULL || drvname == NULL) {
 270                 errno = EINVAL;
 271                 return NULL;
 272         }
 273
 274         if (bus->drivers == NULL) {
 275                 bus->drivers = sysfs_get_bus_drivers(bus);
 276                 if (bus->drivers == NULL)
 277                         return NULL;
 278         }
 279
 280         return (struct sysfs_driver *)dlist_find_custom(bus->drivers, drvname,
 281                 bus_driver_name_equal);
 282 }
 283
 284 /**
 285  * sysfs_get_bus_attributes: returns bus' dlist of attributes
 286  * @bus: bus to get attributes for.
 287  * returns dlist of attributes or NULL if there aren't any.
 288  */
 289 struct dlist *sysfs_get_bus_attributes(struct sysfs_bus *bus)
 290 {
 291         if (bus == NULL)
 292                 return NULL;
 293
 294         if (bus->directory == NULL) {
 295                 bus->directory = sysfs_open_directory(bus->path);
 296                 if (bus->directory == NULL)
 297                         return NULL;
 298         }
 299         if (bus->directory->attributes == NULL) {
 300                 if ((sysfs_read_dir_attributes(bus->directory)) != 0)
 301                         return NULL;
 302         }
 303         return bus->directory->attributes;
 304 }
 305
 306 /**
 307  * sysfs_refresh_bus_attributes: refreshes the bus's list of attributes
 308  * @bus: sysfs_bus whose attributes to refresh
 309  *
 310  * NOTE: Upon return, prior references to sysfs_attributes for this bus
 311  *              _may_ not be valid
 312  *
 313  * Returns list of attributes on success and NULL on failure
 314  */
 315 struct dlist *sysfs_refresh_bus_attributes(struct sysfs_bus *bus)
 316 {
 317         if (bus == NULL) {
 318                 errno = EINVAL;
 319                 return NULL;
 320         }
 321
 322         if (bus->directory == NULL)
 323                 return (sysfs_get_bus_attributes(bus));
 324
 325         if ((sysfs_refresh_dir_attributes(bus->directory)) != 0) {
 326                 dprintf("Error refreshing bus attributes\n");
 327                 return NULL;
 328         }
 329
 330         return (bus->directory->attributes);
 331 }
 332
 333 /**
 334  * sysfs_get_bus_attribute: gets a specific bus attribute, if buses had
 335  *      attributes.
 336  * @bus: bus to retrieve attribute from
 337  * @attrname: attribute name to retrieve
 338  * returns reference to sysfs_attribute if found or NULL if not found
 339  */
 340 struct sysfs_attribute *sysfs_get_bus_attribute(struct sysfs_bus *bus,
 341                                                 unsigned char *attrname)
 342 {
 343         struct dlist *attrlist = NULL;
 344
 345         if (bus == NULL) {
 346                 errno = EINVAL;
 347                 return NULL;
 348         }
 349         attrlist = sysfs_get_bus_attributes(bus);
 350         if (attrlist == NULL)
 351                 return NULL;
 352
 353         return sysfs_get_directory_attribute(bus->directory, attrname);
 354 }
 355
 356 /**
 357  * sysfs_open_bus_device: locates a device on a bus and returns it. Device
 358  *      must be closed using sysfs_close_device.
 359  * @busname: Name of bus to search
 360  * @dev_id: Id of device on bus.
 361  * returns sysfs_device if found or NULL if not.
 362  */
 363 struct sysfs_device *sysfs_open_bus_device(unsigned char *busname,
 364                                                         unsigned char *dev_id)
 365 {
 366         struct sysfs_device *rdev = NULL;
 367         char path[SYSFS_PATH_MAX];
 368
 369         if (busname == NULL || dev_id == NULL) {
 370                 errno = EINVAL;
 371                 return NULL;
 372         }
 373
 374         memset(path, 0, SYSFS_PATH_MAX);
 375         if (sysfs_get_mnt_path(path, SYSFS_PATH_MAX) != 0) {
 376                 dprintf("Error getting sysfs mount point\n");
 377                 return NULL;
 378         }
 379
 380         strcat(path, "/");
 381         strcat(path, SYSFS_BUS_NAME);
 382         strcat(path, "/");
 383         strcat(path, busname);
 384         strcat(path, "/");
 385         strcat(path, SYSFS_DEVICES_NAME);
 386         strcat(path, "/");
 387         strcat(path, dev_id);
 388
 389         rdev = sysfs_open_device_path(path);
 390         if (rdev == NULL) {
 391                 dprintf("Error getting device %s on bus %s\n",
 392                                 dev_id, busname);
 393                 return NULL;
 394         }
 395
 396         return rdev;
 397 }
 398
 399 /**
 400  * sysfs_find_driver_bus: locates the bus the driver is on.
 401  * @driver: name of the driver to locate
 402  * @busname: buffer to copy name to
 403  * @bsize: buffer size
 404  * returns 0 with success, -1 with error
 405  */
 406 int sysfs_find_driver_bus(const unsigned char *driver, unsigned char *busname,
 407                                                         size_t bsize)
 408 {
 409         unsigned char subsys[SYSFS_PATH_MAX], *bus = NULL, *curdrv = NULL;
 410         struct dlist *buslist = NULL, *drivers = NULL;
 411
 412         if (driver == NULL || busname == NULL) {
 413                 errno = EINVAL;
 414                 return -1;
 415         }
 416
 417         memset(subsys, 0, SYSFS_PATH_MAX);
 418         strcat(subsys, "/");
 419         strcpy(subsys, SYSFS_BUS_NAME);
 420         buslist = sysfs_open_subsystem_list(subsys);
 421         if (buslist != NULL) {
 422                 dlist_for_each_data(buslist, bus, char) {
 423                         memset(subsys, 0, SYSFS_PATH_MAX);
 424                         strcat(subsys, "/");
 425                         strcpy(subsys, SYSFS_BUS_NAME);
 426                         strcat(subsys, "/");
 427                         strcat(subsys, bus);
 428                         strcat(subsys, "/");
 429                         strcat(subsys, SYSFS_DRIVERS_NAME);
 430                         drivers = sysfs_open_subsystem_list(subsys);
 431                         if (drivers != NULL) {
 432                                 dlist_for_each_data(drivers, curdrv, char) {
 433                                         if (strcmp(driver, curdrv) == 0) {
 434                                                 strncpy(busname, bus, bsize);
 435                                                 sysfs_close_list(drivers);
 436                                                 sysfs_close_list(buslist);
 437                                                 return 0;
 438                                         }
 439                                 }
 440                                 sysfs_close_list(drivers);
 441                         }
 442                 }
 443                 sysfs_close_list(buslist);
 444         }
 445         return -1;
 446 }