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_lib.h"
  35 #include "logging.h"
  36
  37 /* list of subsystem specific files, NULL if there is no file to wait for */
  38 static struct subsystem_file {
  39         char *subsystem;
  40         char *file;
  41 } subsystem_files[] = {
  42         { .subsystem = "net",           .file = "ifindex" },
  43         { .subsystem = "scsi_host",     .file = "unique_id" },
  44         { .subsystem = "scsi_device",   .file = NULL },
  45         { .subsystem = "pcmcia_socket", .file = "card_type" },
  46         { .subsystem = "usb_host",      .file = NULL },
  47         { .subsystem = "bluetooth",     .file = "address" },
  48         { .subsystem = "firmware",      .file = "data" },
  49         { .subsystem = "i2c-adapter",   .file = NULL },
  50         { .subsystem = "pci_bus",       .file = NULL },
  51         { .subsystem = "ieee1394",      .file = NULL },
  52         { .subsystem = "ieee1394_host", .file = NULL },
  53         { .subsystem = "ieee1394_node", .file = NULL },
  54         { NULL, NULL }
  55 };
  56
  57 int subsystem_expect_no_dev(const char *subsystem)
  58 {
  59         struct subsystem_file *file;
  60
  61         for (file = subsystem_files; file->subsystem != NULL; file++)
  62                 if (strcmp(subsystem, file->subsystem) == 0)
  63                         return 1;
  64
  65         return 0;
  66 }
  67
  68 /* get subsystem specific files, returns "dev" if no other found */
  69 static char *get_subsystem_specific_file(const char *subsystem)
  70 {
  71         struct subsystem_file *file;
  72
  73         /* look if we want to look for another file instead of "dev" */
  74         for (file = subsystem_files; file->subsystem != NULL; file++)
  75                 if (strcmp(subsystem, file->subsystem) == 0)
  76                         return file->file;
  77
  78         return "dev";
  79 }
  80
  81 /* wait for class pecific file to show up */
  82 static int wait_for_class_device_attributes(struct sysfs_class_device *class_dev,
  83                                             const char **error)
  84 {
  85         const char *file;
  86         char filename[SYSFS_PATH_MAX];
  87         int loop;
  88
  89         file = get_subsystem_specific_file(class_dev->classname);
  90         if (file == NULL) {
  91                 dbg("class '%s' has no file to wait for", class_dev->classname);
  92                 return 0;
  93         }
  94
  95         snprintf(filename, SYSFS_PATH_MAX-1, "%s/%s", class_dev->path, file);
  96         dbg("looking at class '%s' for specific file '%s'", class_dev->classname, filename);
  97
  98         loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND;
  99         while (--loop) {
 100                 struct stat stats;
 101
 102                 if (stat(class_dev->path, &stats) == -1) {
 103                         dbg("'%s' now disappeared (probably remove has beaten us)", class_dev->path);
 104                         return -ENODEV;
 105                 }
 106
 107                 if (stat(filename, &stats) == 0) {
 108                         dbg("class '%s' specific file '%s' found", class_dev->classname, file);
 109                         return 0;
 110                 }
 111
 112                 usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND);
 113         }
 114
 115         dbg("error: getting class '%s' specific file '%s'", class_dev->classname, file);
 116         if (error)
 117                 *error = "class specific file unavailable";
 118         return -ENOENT;
 119 }
 120
 121 /* check if we need to wait for a physical device */
 122 static int class_device_expect_no_device_link(struct sysfs_class_device *class_dev)
 123 {
 124         /* list of devices without a "device" symlink to the physical device
 125          * if device is set to NULL, no devices in that subsystem has a link */
 126         static struct class_device {
 127                 char *subsystem;
 128                 char *device;
 129         } class_device[] = {
 130                 { .subsystem = "block",         .device = "double" },
 131                 { .subsystem = "block",         .device = "nb" },
 132                 { .subsystem = "block",         .device = "ram" },
 133                 { .subsystem = "block",         .device = "loop" },
 134                 { .subsystem = "block",         .device = "fd" },
 135                 { .subsystem = "block",         .device = "md" },
 136                 { .subsystem = "block",         .device = "dos_cd" },
 137                 { .subsystem = "block",         .device = "rflash" },
 138                 { .subsystem = "block",         .device = "rom" },
 139                 { .subsystem = "block",         .device = "rrom" },
 140                 { .subsystem = "block",         .device = "flash" },
 141                 { .subsystem = "block",         .device = "msd" },
 142                 { .subsystem = "block",         .device = "sbpcd" },
 143                 { .subsystem = "block",         .device = "pcd" },
 144                 { .subsystem = "block",         .device = "pf" },
 145                 { .subsystem = "block",         .device = "scd" },
 146                 { .subsystem = "block",         .device = "ubd" },
 147                 { .subsystem = "block",         .device = "dm-" },
 148                 { .subsystem = "input",         .device = "event" },
 149                 { .subsystem = "input",         .device = "mice" },
 150                 { .subsystem = "input",         .device = "mouse" },
 151                 { .subsystem = "input",         .device = "ts" },
 152                 { .subsystem = "vc",            .device = NULL },
 153                 { .subsystem = "tty",           .device = NULL },
 154                 { .subsystem = "cpuid",         .device = "cpu" },
 155                 { .subsystem = "graphics",      .device = "fb" },
 156                 { .subsystem = "mem",           .device = NULL },
 157                 { .subsystem = "misc",          .device = NULL },
 158                 { .subsystem = "msr",           .device = NULL },
 159                 { .subsystem = "netlink",       .device = NULL },
 160                 { .subsystem = "net",           .device = "sit" },
 161                 { .subsystem = "net",           .device = "lo" },
 162                 { .subsystem = "net",           .device = "tap" },
 163                 { .subsystem = "net",           .device = "ipsec" },
 164                 { .subsystem = "net",           .device = "dummy" },
 165                 { .subsystem = "net",           .device = "irda" },
 166                 { .subsystem = "net",           .device = "ppp" },
 167                 { .subsystem = "net",           .device = "tun" },
 168                 { .subsystem = "net",           .device = "pan" },
 169                 { .subsystem = "net",           .device = "bnep" },
 170                 { .subsystem = "net",           .device = "vmnet" },
 171                 { .subsystem = "ppp",           .device = NULL },
 172                 { .subsystem = "sound",         .device = NULL },
 173                 { .subsystem = "printer",       .device = "lp" },
 174                 { .subsystem = "nvidia",        .device = NULL },
 175                 { .subsystem = "video4linux",   .device = "vbi" },
 176                 { .subsystem = "dvb",           .device = NULL },
 177                 { .subsystem = "lirc",          .device = NULL },
 178                 { .subsystem = "firmware",      .device = NULL },
 179                 { .subsystem = "drm",           .device = NULL },
 180                 { .subsystem = "pci_bus",       .device = NULL },
 181                 { .subsystem = "ieee1394",      .device = NULL },
 182                 { .subsystem = "ieee1394_host", .device = NULL },
 183                 { .subsystem = "ieee1394_node", .device = NULL },
 184                 { .subsystem = "raw",           .device = NULL },
 185                 { .subsystem = "zaptel",        .device = NULL },
 186                 { .subsystem = "tiglusb",       .device = NULL },
 187                 { .subsystem = "ppdev",         .device = NULL },
 188                 { .subsystem = "ticables",      .device = NULL },
 189                 { .subsystem = "snsc",          .device = NULL },
 190                 { .subsystem = "staliomem",     .device = NULL },
 191                 { .subsystem = "tape",          .device = NULL },
 192                 { .subsystem = "ip2",           .device = NULL },
 193                 { .subsystem = "tpqic02",       .device = NULL },
 194                 { .subsystem = "dsp56k",        .device = NULL },
 195                 { .subsystem = "zft",           .device = NULL },
 196                 { .subsystem = "adb",           .device = NULL },
 197                 { .subsystem = "cosa",          .device = NULL },
 198                 { .subsystem = "pg",            .device = NULL },
 199                 { .subsystem = "pt",            .device = NULL },
 200                 { .subsystem = "capi",          .device = NULL },
 201                 { NULL, NULL }
 202         };
 203         struct class_device *classdevice;
 204         int len;
 205
 206         /* the kernel may tell us what to wait for */
 207         if (kernel_release_satisfactory(2,6,10) > 0)
 208                 if (getenv("PHYSDEVPATH") == NULL) {
 209                         dbg("the kernel says, that there is no physical device for '%s'", class_dev->path);
 210                         return 1;
 211                 }
 212
 213         for (classdevice = class_device; classdevice->subsystem != NULL; classdevice++) {
 214                 if (strcmp(class_dev->classname, classdevice->subsystem) == 0) {
 215                         /* see if no device in this class is expected to have a device-link */
 216                         if (classdevice->device == NULL)
 217                                 return 1;
 218
 219                         len = strlen(classdevice->device);
 220
 221                         /* see if device name matches */
 222                         if (strncmp(class_dev->name, classdevice->device, len) != 0)
 223                                 continue;
 224
 225                         /* exact name match */
 226                         if (strlen(class_dev->name) == len)
 227                                 return 1;
 228
 229                         /* name match with instance number */
 230                         if (isdigit(class_dev->name[len]))
 231                                 return 1;
 232                 }
 233         }
 234
 235         return 0;
 236 }
 237
 238 /* skip waiting for the bus of the devices device */
 239 static int class_device_expect_no_bus(struct sysfs_class_device *class_dev)
 240 {
 241         static char *devices_without_bus[] = {
 242                 "scsi_host",
 243                 "i2c-adapter",
 244                 "i2c-dev",
 245                 NULL
 246         };
 247         char **device;
 248
 249         for (device = devices_without_bus; *device != NULL; device++) {
 250                 int len = strlen(*device);
 251
 252                 if (strncmp(class_dev->classname, *device, len) == 0)
 253                         return 1;
 254         }
 255
 256         return 0;
 257 }
 258
 259 /* wait for a devices device specific file to show up */
 260 int wait_for_devices_device(struct sysfs_device *devices_dev,
 261                         const char **error)
 262 {
 263         static struct device_file {
 264                 char *bus;
 265                 char *file;
 266         } device_files[] = {
 267                 { .bus = "scsi",        .file = "vendor" },
 268                 { .bus = "usb",         .file = "idVendor" },
 269                 { .bus = "usb",         .file = "iInterface" },
 270                 { .bus = "usb",         .file = "bNumEndpoints" },
 271                 { .bus = "usb-serial",  .file = "detach_state" },
 272                 { .bus = "ide",         .file = "detach_state" },
 273                 { .bus = "pci",         .file = "vendor" },
 274                 { .bus = "platform",    .file = "detach_state" },
 275                 { .bus = "i2c",         .file = "detach_state" },
 276                 { .bus = "ieee1394",    .file = "node_count" },
 277                 { .bus = "ieee1394",    .file = "nodeid" },
 278                 { .bus = "ieee1394",    .file = "address" },
 279                 { NULL, NULL }
 280         };
 281         struct device_file *devicefile;
 282         int loop;
 283
 284         /* the kernel may tell us what to wait for */
 285         if (kernel_release_satisfactory(2,6,10) > 0)
 286                 if (getenv("PHYSDEVBUS") == NULL) {
 287                         dbg("the kernel says, that there is no bus for '%s'", devices_dev->path);
 288                         return 0;
 289                 }
 290
 291         /* wait for the bus device link to the devices device */
 292         loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND;
 293         while (--loop) {
 294                 if (sysfs_get_device_bus(devices_dev) == 0)
 295                         break;
 296
 297                 usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND);
 298         }
 299         if (loop == 0) {
 300                 dbg("error: getting bus device link");
 301                 if (error)
 302                         *error = "no bus device link";
 303                 return -1;
 304         }
 305         dbg("bus device link found for bus '%s'", devices_dev->bus);
 306
 307         /* wait for a bus device specific file to show up */
 308         loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND;
 309         while (--loop) {
 310                 int found_bus_type = 0;
 311
 312                 for (devicefile = device_files; devicefile->bus != NULL; devicefile++) {
 313                         if (strcmp(devices_dev->bus, devicefile->bus) == 0) {
 314                                 char filename[SYSFS_PATH_MAX];
 315                                 struct stat stats;
 316
 317                                 found_bus_type = 1;
 318                                 snprintf(filename, SYSFS_PATH_MAX-1, "%s/%s", devices_dev->path, devicefile->file);
 319                                 dbg("looking at bus '%s' device for specific file '%s'", devices_dev->bus, filename);
 320
 321                                 if (stat(filename, &stats) == 0) {
 322                                         dbg("bus '%s' device specific file '%s' found", devices_dev->bus, devicefile->file);
 323                                         return 0;
 324                                 }
 325                         }
 326                 }
 327                 if (found_bus_type == 0) {
 328                         if (error)
 329                                 *error = "unknown bus";
 330                         info("error: unknown bus, please report to "
 331                              "<linux-hotplug-devel@lists.sourceforge.net> '%s'", devices_dev->bus);
 332                         return -1;
 333                 }
 334                 usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND);
 335         }
 336
 337         dbg("error: getting '%s' device specific file '%s'", devices_dev->bus, devicefile->file);
 338         if (error)
 339                 *error = "bus device specific file unavailable";
 340         return -1;
 341 }
 342
 343
 344 struct sysfs_class_device *wait_class_device_open(const char *path)
 345 {
 346         struct sysfs_class_device *class_dev;
 347         int loop;
 348
 349         loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND;
 350         while (--loop) {
 351                 class_dev = sysfs_open_class_device_path(path);
 352                 if (class_dev)
 353                         break;
 354
 355                 usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND);
 356         }
 357
 358         return (class_dev);
 359 }
 360
 361 int wait_for_class_device(struct sysfs_class_device *class_dev,
 362                           const char **error)
 363 {
 364         struct sysfs_class_device *class_dev_parent;
 365         struct sysfs_device *devices_dev = NULL;
 366         int loop;
 367
 368         if (wait_for_class_device_attributes(class_dev, error) != 0)
 369                 return -ENOENT;
 370
 371         /* skip devices without devices-link */
 372         if (class_device_expect_no_device_link(class_dev)) {
 373                 dbg("no device symlink expected for '%s', ", class_dev->name);
 374                 return 0;
 375         }
 376
 377         /* the symlink may be on the parent device */
 378         class_dev_parent = sysfs_get_classdev_parent(class_dev);
 379         if (class_dev_parent)
 380                 dbg("looking at parent device for device link '%s'", class_dev_parent->path);
 381
 382         /* wait for the symlink to the devices device */
 383         dbg("waiting for symlink to devices device");
 384         loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND;
 385         while (--loop) {
 386                 if (class_dev_parent)
 387                         devices_dev = sysfs_get_classdev_device(class_dev_parent);
 388                 else
 389                         devices_dev = sysfs_get_classdev_device(class_dev);
 390
 391                 if (devices_dev)
 392                         break;
 393
 394                 usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND);
 395         }
 396         if (!devices_dev) {
 397                 dbg(" error: no devices device symlink found");
 398                 if (error)
 399                         *error = "no device symlink";
 400                 return -ENODEV;
 401         }
 402         dbg("device symlink found pointing to '%s'", devices_dev->path);
 403
 404         /* wait for the devices device */
 405         if (class_device_expect_no_bus(class_dev)) {
 406                 dbg("no bus device expected for '%s', ", class_dev->classname);
 407                 return 0;
 408         }
 409
 410         return wait_for_devices_device(devices_dev, error);
 411 }
 412
 413 struct sysfs_device *wait_devices_device_open(const char *path)
 414 {
 415         struct sysfs_device *devices_dev;
 416         int loop;
 417
 418         loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND;
 419         while (--loop) {
 420                 devices_dev = sysfs_open_device_path(path);
 421                 if (devices_dev)
 422                         break;
 423
 424                 usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND);
 425         }
 426
 427         return(devices_dev);
 428 }