udev_sysfs.c

   1 /*
   2  * udev_sysfs.c  - sysfs linux kernel specific knowledge
   3  *
   4  * Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
   5  * Copyright (C) 2004 Greg Kroah-Hartman <greg@kroah.com>
   6  *
   7  *      This program is free software; you can redistribute it and/or modify it
   8  *      under the terms of the GNU General Public License as published by the
   9  *      Free Software Foundation version 2 of the License.
  10  *
  11  *      This program is distributed in the hope that it will be useful, but
  12  *      WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  *      General Public License for more details.
  15  *
  16  *      You should have received a copy of the GNU General Public License along
  17  *      with this program; if not, write to the Free Software Foundation, Inc.,
  18  *      675 Mass Ave, Cambridge, MA 02139, USA.
  19  *
  20  */
  21
  22 #include <stdio.h>
  23 #include <stddef.h>
  24 #include <stdlib.h>
  25 #include <unistd.h>
  26 #include <string.h>
  27 #include <ctype.h>
  28 #include <errno.h>
  29 #include <sys/stat.h>
  30
  31 #include "libsysfs/sysfs/libsysfs.h"
  32 #include "udev_version.h"
  33 #include "udev_sysfs.h"
  34 #include "udev_utils.h"
  35 #include "logging.h"
  36
  37 /* list of subsystem specific files, NULL if there is no file to wait for */
  38 static const struct subsystem_file {
  39         const char *subsystem;
  40         const char *file;
  41 } subsystem_files[] = {
  42         { .subsystem = "class",         .file = NULL },
  43         { .subsystem = "net",           .file = "ifindex" },
  44         { .subsystem = "scsi_host",     .file = "unique_id" },
  45         { .subsystem = "scsi_device",   .file = NULL },
  46         { .subsystem = "pcmcia_socket", .file = "card_type" },
  47         { .subsystem = "usb_host",      .file = NULL },
  48         { .subsystem = "bluetooth",     .file = "address" },
  49         { .subsystem = "firmware",      .file = "data" },
  50         { .subsystem = "i2c-adapter",   .file = NULL },
  51         { .subsystem = "pci_bus",       .file = NULL },
  52         { .subsystem = "ieee1394",      .file = NULL },
  53         { .subsystem = "ieee1394_host", .file = NULL },
  54         { .subsystem = "ieee1394_node", .file = NULL },
  55         { .subsystem = "fc_transport",  .file = "port_id" },
  56         { .subsystem = "fc_host",       .file = "port_id" },
  57         { .subsystem = "spi_transport", .file = "width" },
  58         { .subsystem = "spi_host",      .file = "width" },
  59         { NULL, NULL }
  60 };
  61
  62 dev_t get_devt(struct sysfs_class_device *class_dev)
  63 {
  64         struct sysfs_attribute *attr = NULL;
  65         unsigned int major, minor;
  66
  67         attr = sysfs_get_classdev_attr(class_dev, "dev");
  68         if (attr == NULL)
  69                 return 0;
  70         dbg("dev='%s'", attr->value);
  71
  72         if (sscanf(attr->value, "%u:%u", &major, &minor) != 2)
  73                 return 0;
  74         dbg("found major=%d, minor=%d", major, minor);
  75
  76         return makedev(major, minor);
  77 }
  78
  79 int subsystem_expect_no_dev(const char *subsystem)
  80 {
  81         const struct subsystem_file *file;
  82
  83         for (file = subsystem_files; file->subsystem != NULL; file++)
  84                 if (strcmp(subsystem, file->subsystem) == 0)
  85                         return 1;
  86
  87         return 0;
  88 }
  89
  90 /* get subsystem specific files, returns "dev" if no other found */
  91 static const char *get_subsystem_specific_file(const char *subsystem)
  92 {
  93         const struct subsystem_file *file;
  94
  95         /* look if we want to look for another file instead of "dev" */
  96         for (file = subsystem_files; file->subsystem != NULL; file++)
  97                 if (strcmp(subsystem, file->subsystem) == 0)
  98                         return file->file;
  99
 100         return "dev";
 101 }
 102
 103 /* wait for class pecific file to show up */
 104 static int wait_for_class_device_attributes(struct sysfs_class_device *class_dev,
 105                                             const char **error)
 106 {
 107         const char *file;
 108         char filename[SYSFS_PATH_MAX];
 109         int loop;
 110
 111         file = get_subsystem_specific_file(class_dev->classname);
 112         if (file == NULL) {
 113                 dbg("class '%s' has no file to wait for", class_dev->classname);
 114                 return 0;
 115         }
 116
 117         snprintf(filename, SYSFS_PATH_MAX-1, "%s/%s", class_dev->path, file);
 118         dbg("looking at class '%s' for specific file '%s'", class_dev->classname, filename);
 119
 120         loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND;
 121         while (--loop) {
 122                 struct stat stats;
 123
 124                 if (stat(class_dev->path, &stats) == -1) {
 125                         dbg("'%s' now disappeared (probably remove has beaten us)", class_dev->path);
 126                         return -ENODEV;
 127                 }
 128
 129                 if (stat(filename, &stats) == 0) {
 130                         dbg("class '%s' specific file '%s' found", class_dev->classname, file);
 131                         return 0;
 132                 }
 133
 134                 usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND);
 135         }
 136
 137         dbg("error: getting class '%s' specific file '%s'", class_dev->classname, file);
 138         if (error)
 139                 *error = "class specific file unavailable";
 140         return -ENOENT;
 141 }
 142
 143 /* check if we need to wait for a physical device */
 144 static int class_device_expect_no_device_link(struct sysfs_class_device *class_dev)
 145 {
 146         /* list of devices without a "device" symlink to the physical device
 147          * if device is set to NULL, no devices in that subsystem has a link */
 148         static const struct class_device {
 149                 const char *subsystem;
 150                 const char *device;
 151         } class_device[] = {
 152                 { .subsystem = "block",         .device = "double" },
 153                 { .subsystem = "block",         .device = "nb" },
 154                 { .subsystem = "block",         .device = "ram" },
 155                 { .subsystem = "block",         .device = "loop" },
 156                 { .subsystem = "block",         .device = "fd" },
 157                 { .subsystem = "block",         .device = "md" },
 158                 { .subsystem = "block",         .device = "dos_cd" },
 159                 { .subsystem = "block",         .device = "rflash" },
 160                 { .subsystem = "block",         .device = "rom" },
 161                 { .subsystem = "block",         .device = "rrom" },
 162                 { .subsystem = "block",         .device = "flash" },
 163                 { .subsystem = "block",         .device = "msd" },
 164                 { .subsystem = "block",         .device = "sbpcd" },
 165                 { .subsystem = "block",         .device = "pcd" },
 166                 { .subsystem = "block",         .device = "pf" },
 167                 { .subsystem = "block",         .device = "scd" },
 168                 { .subsystem = "block",         .device = "ubd" },
 169                 { .subsystem = "block",         .device = "dm-" },
 170                 { .subsystem = "block",         .device = "bcrypt" },
 171                 { .subsystem = "input",         .device = "event" },
 172                 { .subsystem = "input",         .device = "mice" },
 173                 { .subsystem = "input",         .device = "mouse" },
 174                 { .subsystem = "input",         .device = "ts" },
 175                 { .subsystem = "vc",            .device = NULL },
 176                 { .subsystem = "tty",           .device = NULL },
 177                 { .subsystem = "cpuid",         .device = "cpu" },
 178                 { .subsystem = "graphics",      .device = "fb" },
 179                 { .subsystem = "mem",           .device = NULL },
 180                 { .subsystem = "misc",          .device = NULL },
 181                 { .subsystem = "msr",           .device = NULL },
 182                 { .subsystem = "netlink",       .device = NULL },
 183                 { .subsystem = "net",           .device = "sit" },
 184                 { .subsystem = "net",           .device = "lo" },
 185                 { .subsystem = "net",           .device = "tap" },
 186                 { .subsystem = "net",           .device = "ipsec" },
 187                 { .subsystem = "net",           .device = "dummy" },
 188                 { .subsystem = "net",           .device = "irda" },
 189                 { .subsystem = "net",           .device = "ppp" },
 190                 { .subsystem = "net",           .device = "tun" },
 191                 { .subsystem = "net",           .device = "pan" },
 192                 { .subsystem = "net",           .device = "bnep" },
 193                 { .subsystem = "net",           .device = "vmnet" },
 194                 { .subsystem = "net",           .device = "ippp" },
 195                 { .subsystem = "net",           .device = "nlv" },
 196                 { .subsystem = "net",           .device = "atml" },
 197                 { .subsystem = "ppp",           .device = NULL },
 198                 { .subsystem = "sound",         .device = NULL },
 199                 { .subsystem = "printer",       .device = "lp" },
 200                 { .subsystem = "ppdev",         .device = NULL },
 201                 { .subsystem = "nvidia",        .device = NULL },
 202                 { .subsystem = "video4linux",   .device = "vbi" },
 203                 { .subsystem = "dvb",           .device = NULL },
 204                 { .subsystem = "lirc",          .device = NULL },
 205                 { .subsystem = "firmware",      .device = NULL },
 206                 { .subsystem = "drm",           .device = NULL },
 207                 { .subsystem = "pci_bus",       .device = NULL },
 208                 { .subsystem = "ieee1394",      .device = NULL },
 209                 { .subsystem = "ieee1394_host", .device = NULL },
 210                 { .subsystem = "ieee1394_node", .device = NULL },
 211                 { .subsystem = "raw",           .device = NULL },
 212                 { .subsystem = "zaptel",        .device = NULL },
 213                 { .subsystem = "tiglusb",       .device = NULL },
 214                 { .subsystem = "ppdev",         .device = NULL },
 215                 { .subsystem = "ticables",      .device = NULL },
 216                 { .subsystem = "snsc",          .device = NULL },
 217                 { .subsystem = "staliomem",     .device = NULL },
 218                 { .subsystem = "tape",          .device = NULL },
 219                 { .subsystem = "ip2",           .device = NULL },
 220                 { .subsystem = "tpqic02",       .device = NULL },
 221                 { .subsystem = "dsp56k",        .device = NULL },
 222                 { .subsystem = "zft",           .device = NULL },
 223                 { .subsystem = "adb",           .device = NULL },
 224                 { .subsystem = "cosa",          .device = NULL },
 225                 { .subsystem = "pg",            .device = NULL },
 226                 { .subsystem = "pt",            .device = NULL },
 227                 { .subsystem = "capi",          .device = NULL },
 228                 { NULL, NULL }
 229         };
 230         const struct class_device *classdevice;
 231         unsigned int len;
 232
 233         /* the kernel may tell us what to wait for */
 234         if (kernel_release_satisfactory(2,6,10) > 0)
 235                 if (getenv("PHYSDEVPATH") == NULL) {
 236                         dbg("the kernel says, that there is no physical device for '%s'", class_dev->path);
 237                         return 1;
 238                 }
 239
 240         for (classdevice = class_device; classdevice->subsystem != NULL; classdevice++) {
 241                 if (strcmp(class_dev->classname, classdevice->subsystem) == 0) {
 242                         /* see if no device in this class is expected to have a device-link */
 243                         if (classdevice->device == NULL)
 244                                 return 1;
 245
 246                         len = strlen(classdevice->device);
 247
 248                         /* see if device name matches */
 249                         if (strncmp(class_dev->name, classdevice->device, len) != 0)
 250                                 continue;
 251
 252                         /* exact name match */
 253                         if (strlen(class_dev->name) == len)
 254                                 return 1;
 255
 256                         /* name match with instance number */
 257                         if (isdigit(class_dev->name[len]))
 258                                 return 1;
 259                 }
 260         }
 261
 262         return 0;
 263 }
 264
 265 /* skip waiting for the bus of the devices device */
 266 static int class_device_expect_no_bus(struct sysfs_class_device *class_dev)
 267 {
 268         static const char *devices_without_bus[] = {
 269                 "scsi_host",
 270                 "i2c-adapter",
 271                 "i2c-dev",
 272                 NULL
 273         };
 274         const char **device;
 275
 276         for (device = devices_without_bus; *device != NULL; device++) {
 277                 int len = strlen(*device);
 278
 279                 if (strncmp(class_dev->classname, *device, len) == 0)
 280                         return 1;
 281         }
 282
 283         return 0;
 284 }
 285
 286 /* wait for a devices device specific file to show up */
 287 int wait_for_devices_device(struct sysfs_device *devices_dev,
 288                         const char **error)
 289 {
 290         static const struct device_file {
 291                 const char *bus;
 292                 const char *file;
 293         } device_files[] = {
 294                 { .bus = "scsi",        .file = "vendor" },
 295                 { .bus = "usb",         .file = "idVendor" },
 296                 { .bus = "usb",         .file = "iInterface" },
 297                 { .bus = "usb",         .file = "bNumEndpoints" },
 298                 { .bus = "usb-serial",  .file = "detach_state" },
 299                 { .bus = "ide",         .file = "detach_state" },
 300                 { .bus = "pci",         .file = "vendor" },
 301                 { .bus = "platform",    .file = "detach_state" },
 302                 { .bus = "pcmcia",      .file = "detach_state" },
 303                 { .bus = "i2c",         .file = "detach_state" },
 304                 { .bus = "ieee1394",    .file = "node_count" },
 305                 { .bus = "ieee1394",    .file = "nodeid" },
 306                 { .bus = "ieee1394",    .file = "address" },
 307                 { .bus = "bttv-sub",    .file = NULL },
 308                 { .bus = "pnp",         .file = "detach_state" },
 309                 { .bus = "eisa",        .file = "detach_state" },
 310                 { .bus = "pseudo",      .file = "detach_state" },
 311                 { .bus = "mmc",         .file = "detach_state" },
 312                 { .bus = "macio",       .file = "detach_state" },
 313                 { .bus = "of_platform", .file = "detach_state" },
 314                 { .bus = "vio",         .file = "detach_state" },
 315                 { .bus = "ecard",       .file = "detach_state" },
 316                 { .bus = "sa1111-rab",  .file = "detach_state" },
 317                 { .bus = "amba",        .file = "detach_state" },
 318                 { .bus = "locomo-bus",  .file = "detach_state" },
 319                 { .bus = "logicmodule", .file = "detach_state" },
 320                 { .bus = "parisc",      .file = "detach_state" },
 321                 { .bus = "ocp",         .file = "detach_state" },
 322                 { .bus = "dio",         .file = "detach_state" },
 323                 { .bus = "MCA",         .file = "detach_state" },
 324                 { .bus = "wl",          .file = "detach_state" },
 325                 { .bus = "ccwgroup",    .file = "detach_state" },
 326                 { .bus = "css",         .file = "detach_state" },
 327                 { .bus = "ccw",         .file = "detach_state" },
 328                 { .bus = "iucv",        .file = "detach_state" },
 329                 { NULL, NULL }
 330         };
 331         const struct device_file *devicefile;
 332         int loop;
 333
 334         /* the kernel may tell us what to wait for */
 335         if (kernel_release_satisfactory(2,6,10) > 0)
 336                 if (getenv("PHYSDEVBUS") == NULL) {
 337                         dbg("the kernel says, that there is no bus for '%s'", devices_dev->path);
 338                         return 0;
 339                 }
 340
 341         /* wait for the bus device link to the devices device */
 342         loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND;
 343         while (--loop) {
 344                 if (sysfs_get_device_bus(devices_dev) == 0)
 345                         break;
 346
 347                 usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND);
 348         }
 349         if (loop == 0) {
 350                 dbg("error: getting bus device link");
 351                 if (error)
 352                         *error = "no bus device link";
 353                 return -1;
 354         }
 355         dbg("bus device link found for bus '%s'", devices_dev->bus);
 356
 357         /* wait for a bus device specific file to show up */
 358         loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND;
 359         while (--loop) {
 360                 int found_bus_type = 0;
 361
 362                 for (devicefile = device_files; devicefile->bus != NULL; devicefile++) {
 363                         if (strcmp(devices_dev->bus, devicefile->bus) == 0) {
 364                                 char filename[SYSFS_PATH_MAX];
 365                                 struct stat stats;
 366
 367                                 if (devicefile->file == NULL) {
 368                                         dbg("bus '%s' has no file to wait for", devices_dev->bus);
 369                                         return 0;
 370                                 }
 371
 372                                 found_bus_type = 1;
 373                                 snprintf(filename, SYSFS_PATH_MAX-1, "%s/%s", devices_dev->path, devicefile->file);
 374                                 dbg("looking at bus '%s' device for specific file '%s'", devices_dev->bus, filename);
 375
 376                                 if (stat(filename, &stats) == 0) {
 377                                         dbg("bus '%s' device specific file '%s' found", devices_dev->bus, devicefile->file);
 378                                         return 0;
 379                                 }
 380                         }
 381                 }
 382                 if (found_bus_type == 0) {
 383                         if (error)
 384                                 *error = "unknown bus";
 385                         info("error: unknown bus, please report to "
 386                              "<linux-hotplug-devel@lists.sourceforge.net> '%s'", devices_dev->bus);
 387                         return -1;
 388                 }
 389                 usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND);
 390         }
 391
 392         dbg("error: getting '%s' device specific file '%s'", devices_dev->bus, devicefile->file);
 393         if (error)
 394                 *error = "bus device specific file unavailable";
 395         return -1;
 396 }
 397
 398
 399 struct sysfs_class_device *wait_class_device_open(const char *path)
 400 {
 401         struct sysfs_class_device *class_dev = NULL;
 402         int loop;
 403
 404         loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND;
 405         while (--loop) {
 406                 class_dev = sysfs_open_class_device_path(path);
 407                 if (class_dev)
 408                         break;
 409
 410                 usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND);
 411         }
 412
 413         return class_dev;
 414 }
 415
 416 int wait_for_class_device(struct sysfs_class_device *class_dev,
 417                           const char **error)
 418 {
 419         struct sysfs_class_device *class_dev_parent;
 420         struct sysfs_device *devices_dev = NULL;
 421         int loop;
 422
 423         if (wait_for_class_device_attributes(class_dev, error) != 0)
 424                 return -ENOENT;
 425
 426         /* skip devices without devices-link */
 427         if (class_device_expect_no_device_link(class_dev)) {
 428                 dbg("no device symlink expected for '%s', ", class_dev->name);
 429                 return 0;
 430         }
 431
 432         /* the symlink may be on the parent device */
 433         class_dev_parent = sysfs_get_classdev_parent(class_dev);
 434         if (class_dev_parent)
 435                 dbg("looking at parent device for device link '%s'", class_dev_parent->path);
 436
 437         /* wait for the symlink to the devices device */
 438         dbg("waiting for symlink to devices device");
 439         loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND;
 440         while (--loop) {
 441                 if (class_dev_parent)
 442                         devices_dev = sysfs_get_classdev_device(class_dev_parent);
 443                 else
 444                         devices_dev = sysfs_get_classdev_device(class_dev);
 445
 446                 if (devices_dev)
 447                         break;
 448
 449                 usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND);
 450         }
 451         if (!devices_dev) {
 452                 dbg(" error: no devices device symlink found");
 453                 if (error)
 454                         *error = "no device symlink";
 455                 return -ENODEV;
 456         }
 457         dbg("device symlink found pointing to '%s'", devices_dev->path);
 458
 459         /* wait for the devices device */
 460         if (class_device_expect_no_bus(class_dev)) {
 461                 dbg("no bus device expected for '%s', ", class_dev->classname);
 462                 return 0;
 463         }
 464
 465         return wait_for_devices_device(devices_dev, error);
 466 }
 467
 468 struct sysfs_device *wait_devices_device_open(const char *path)
 469 {
 470         struct sysfs_device *devices_dev = NULL;
 471         int loop;
 472
 473         loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND;
 474         while (--loop) {
 475                 devices_dev = sysfs_open_device_path(path);
 476                 if (devices_dev)
 477                         break;
 478
 479                 usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND);
 480         }
 481
 482         return devices_dev;
 483 }