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 = "block",         .device = "bcrypt" },
 149                 { .subsystem = "input",         .device = "event" },
 150                 { .subsystem = "input",         .device = "mice" },
 151                 { .subsystem = "input",         .device = "mouse" },
 152                 { .subsystem = "input",         .device = "ts" },
 153                 { .subsystem = "vc",            .device = NULL },
 154                 { .subsystem = "tty",           .device = NULL },
 155                 { .subsystem = "cpuid",         .device = "cpu" },
 156                 { .subsystem = "graphics",      .device = "fb" },
 157                 { .subsystem = "mem",           .device = NULL },
 158                 { .subsystem = "misc",          .device = NULL },
 159                 { .subsystem = "msr",           .device = NULL },
 160                 { .subsystem = "netlink",       .device = NULL },
 161                 { .subsystem = "net",           .device = "sit" },
 162                 { .subsystem = "net",           .device = "lo" },
 163                 { .subsystem = "net",           .device = "tap" },
 164                 { .subsystem = "net",           .device = "ipsec" },
 165                 { .subsystem = "net",           .device = "dummy" },
 166                 { .subsystem = "net",           .device = "irda" },
 167                 { .subsystem = "net",           .device = "ppp" },
 168                 { .subsystem = "net",           .device = "tun" },
 169                 { .subsystem = "net",           .device = "pan" },
 170                 { .subsystem = "net",           .device = "bnep" },
 171                 { .subsystem = "net",           .device = "vmnet" },
 172                 { .subsystem = "net",           .device = "ippp" },
 173                 { .subsystem = "ppp",           .device = NULL },
 174                 { .subsystem = "sound",         .device = NULL },
 175                 { .subsystem = "printer",       .device = "lp" },
 176                 { .subsystem = "nvidia",        .device = NULL },
 177                 { .subsystem = "video4linux",   .device = "vbi" },
 178                 { .subsystem = "dvb",           .device = NULL },
 179                 { .subsystem = "lirc",          .device = NULL },
 180                 { .subsystem = "firmware",      .device = NULL },
 181                 { .subsystem = "drm",           .device = NULL },
 182                 { .subsystem = "pci_bus",       .device = NULL },
 183                 { .subsystem = "ieee1394",      .device = NULL },
 184                 { .subsystem = "ieee1394_host", .device = NULL },
 185                 { .subsystem = "ieee1394_node", .device = NULL },
 186                 { .subsystem = "raw",           .device = NULL },
 187                 { .subsystem = "zaptel",        .device = NULL },
 188                 { .subsystem = "tiglusb",       .device = NULL },
 189                 { .subsystem = "ppdev",         .device = NULL },
 190                 { .subsystem = "ticables",      .device = NULL },
 191                 { .subsystem = "snsc",          .device = NULL },
 192                 { .subsystem = "staliomem",     .device = NULL },
 193                 { .subsystem = "tape",          .device = NULL },
 194                 { .subsystem = "ip2",           .device = NULL },
 195                 { .subsystem = "tpqic02",       .device = NULL },
 196                 { .subsystem = "dsp56k",        .device = NULL },
 197                 { .subsystem = "zft",           .device = NULL },
 198                 { .subsystem = "adb",           .device = NULL },
 199                 { .subsystem = "cosa",          .device = NULL },
 200                 { .subsystem = "pg",            .device = NULL },
 201                 { .subsystem = "pt",            .device = NULL },
 202                 { .subsystem = "capi",          .device = NULL },
 203                 { NULL, NULL }
 204         };
 205         struct class_device *classdevice;
 206         int len;
 207
 208         /* the kernel may tell us what to wait for */
 209         if (kernel_release_satisfactory(2,6,10) > 0)
 210                 if (getenv("PHYSDEVPATH") == NULL) {
 211                         dbg("the kernel says, that there is no physical device for '%s'", class_dev->path);
 212                         return 1;
 213                 }
 214
 215         for (classdevice = class_device; classdevice->subsystem != NULL; classdevice++) {
 216                 if (strcmp(class_dev->classname, classdevice->subsystem) == 0) {
 217                         /* see if no device in this class is expected to have a device-link */
 218                         if (classdevice->device == NULL)
 219                                 return 1;
 220
 221                         len = strlen(classdevice->device);
 222
 223                         /* see if device name matches */
 224                         if (strncmp(class_dev->name, classdevice->device, len) != 0)
 225                                 continue;
 226
 227                         /* exact name match */
 228                         if (strlen(class_dev->name) == len)
 229                                 return 1;
 230
 231                         /* name match with instance number */
 232                         if (isdigit(class_dev->name[len]))
 233                                 return 1;
 234                 }
 235         }
 236
 237         return 0;
 238 }
 239
 240 /* skip waiting for the bus of the devices device */
 241 static int class_device_expect_no_bus(struct sysfs_class_device *class_dev)
 242 {
 243         static char *devices_without_bus[] = {
 244                 "scsi_host",
 245                 "i2c-adapter",
 246                 "i2c-dev",
 247                 NULL
 248         };
 249         char **device;
 250
 251         for (device = devices_without_bus; *device != NULL; device++) {
 252                 int len = strlen(*device);
 253
 254                 if (strncmp(class_dev->classname, *device, len) == 0)
 255                         return 1;
 256         }
 257
 258         return 0;
 259 }
 260
 261 /* wait for a devices device specific file to show up */
 262 int wait_for_devices_device(struct sysfs_device *devices_dev,
 263                         const char **error)
 264 {
 265         static struct device_file {
 266                 char *bus;
 267                 char *file;
 268         } device_files[] = {
 269                 { .bus = "scsi",        .file = "vendor" },
 270                 { .bus = "usb",         .file = "idVendor" },
 271                 { .bus = "usb",         .file = "iInterface" },
 272                 { .bus = "usb",         .file = "bNumEndpoints" },
 273                 { .bus = "usb-serial",  .file = "detach_state" },
 274                 { .bus = "ide",         .file = "detach_state" },
 275                 { .bus = "pci",         .file = "vendor" },
 276                 { .bus = "platform",    .file = "detach_state" },
 277                 { .bus = "i2c",         .file = "detach_state" },
 278                 { .bus = "ieee1394",    .file = "node_count" },
 279                 { .bus = "ieee1394",    .file = "nodeid" },
 280                 { .bus = "ieee1394",    .file = "address" },
 281                 { NULL, NULL }
 282         };
 283         struct device_file *devicefile;
 284         int loop;
 285
 286         /* the kernel may tell us what to wait for */
 287         if (kernel_release_satisfactory(2,6,10) > 0)
 288                 if (getenv("PHYSDEVBUS") == NULL) {
 289                         dbg("the kernel says, that there is no bus for '%s'", devices_dev->path);
 290                         return 0;
 291                 }
 292
 293         /* wait for the bus device link to the devices device */
 294         loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND;
 295         while (--loop) {
 296                 if (sysfs_get_device_bus(devices_dev) == 0)
 297                         break;
 298
 299                 usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND);
 300         }
 301         if (loop == 0) {
 302                 dbg("error: getting bus device link");
 303                 if (error)
 304                         *error = "no bus device link";
 305                 return -1;
 306         }
 307         dbg("bus device link found for bus '%s'", devices_dev->bus);
 308
 309         /* wait for a bus device specific file to show up */
 310         loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND;
 311         while (--loop) {
 312                 int found_bus_type = 0;
 313
 314                 for (devicefile = device_files; devicefile->bus != NULL; devicefile++) {
 315                         if (strcmp(devices_dev->bus, devicefile->bus) == 0) {
 316                                 char filename[SYSFS_PATH_MAX];
 317                                 struct stat stats;
 318
 319                                 found_bus_type = 1;
 320                                 snprintf(filename, SYSFS_PATH_MAX-1, "%s/%s", devices_dev->path, devicefile->file);
 321                                 dbg("looking at bus '%s' device for specific file '%s'", devices_dev->bus, filename);
 322
 323                                 if (stat(filename, &stats) == 0) {
 324                                         dbg("bus '%s' device specific file '%s' found", devices_dev->bus, devicefile->file);
 325                                         return 0;
 326                                 }
 327                         }
 328                 }
 329                 if (found_bus_type == 0) {
 330                         if (error)
 331                                 *error = "unknown bus";
 332                         info("error: unknown bus, please report to "
 333                              "<linux-hotplug-devel@lists.sourceforge.net> '%s'", devices_dev->bus);
 334                         return -1;
 335                 }
 336                 usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND);
 337         }
 338
 339         dbg("error: getting '%s' device specific file '%s'", devices_dev->bus, devicefile->file);
 340         if (error)
 341                 *error = "bus device specific file unavailable";
 342         return -1;
 343 }
 344
 345
 346 struct sysfs_class_device *wait_class_device_open(const char *path)
 347 {
 348         struct sysfs_class_device *class_dev;
 349         int loop;
 350
 351         loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND;
 352         while (--loop) {
 353                 class_dev = sysfs_open_class_device_path(path);
 354                 if (class_dev)
 355                         break;
 356
 357                 usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND);
 358         }
 359
 360         return (class_dev);
 361 }
 362
 363 int wait_for_class_device(struct sysfs_class_device *class_dev,
 364                           const char **error)
 365 {
 366         struct sysfs_class_device *class_dev_parent;
 367         struct sysfs_device *devices_dev = NULL;
 368         int loop;
 369
 370         if (wait_for_class_device_attributes(class_dev, error) != 0)
 371                 return -ENOENT;
 372
 373         /* skip devices without devices-link */
 374         if (class_device_expect_no_device_link(class_dev)) {
 375                 dbg("no device symlink expected for '%s', ", class_dev->name);
 376                 return 0;
 377         }
 378
 379         /* the symlink may be on the parent device */
 380         class_dev_parent = sysfs_get_classdev_parent(class_dev);
 381         if (class_dev_parent)
 382                 dbg("looking at parent device for device link '%s'", class_dev_parent->path);
 383
 384         /* wait for the symlink to the devices device */
 385         dbg("waiting for symlink to devices device");
 386         loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND;
 387         while (--loop) {
 388                 if (class_dev_parent)
 389                         devices_dev = sysfs_get_classdev_device(class_dev_parent);
 390                 else
 391                         devices_dev = sysfs_get_classdev_device(class_dev);
 392
 393                 if (devices_dev)
 394                         break;
 395
 396                 usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND);
 397         }
 398         if (!devices_dev) {
 399                 dbg(" error: no devices device symlink found");
 400                 if (error)
 401                         *error = "no device symlink";
 402                 return -ENODEV;
 403         }
 404         dbg("device symlink found pointing to '%s'", devices_dev->path);
 405
 406         /* wait for the devices device */
 407         if (class_device_expect_no_bus(class_dev)) {
 408                 dbg("no bus device expected for '%s', ", class_dev->classname);
 409                 return 0;
 410         }
 411
 412         return wait_for_devices_device(devices_dev, error);
 413 }
 414
 415 struct sysfs_device *wait_devices_device_open(const char *path)
 416 {
 417         struct sysfs_device *devices_dev;
 418         int loop;
 419
 420         loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND;
 421         while (--loop) {
 422                 devices_dev = sysfs_open_device_path(path);
 423                 if (devices_dev)
 424                         break;
 425
 426                 usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND);
 427         }
 428
 429         return(devices_dev);
 430 }