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Sourcecode: udev version File versions

udev_sysfs.c

/*
 * udev_sysfs.c  - sysfs linux kernel specific knowledge
 *
 * Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
 * Copyright (C) 2004 Greg Kroah-Hartman <greg@kroah.com>
 *
 *    This program is free software; you can redistribute it and/or modify it
 *    under the terms of the GNU General Public License as published by the
 *    Free Software Foundation version 2 of the License.
 * 
 *    This program 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
 *    General Public License for more details.
 * 
 *    You should have received a copy of the GNU General Public License along
 *    with this program; if not, write to the Free Software Foundation, Inc.,
 *    675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */

#include <stdio.h>
#include <stddef.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <ctype.h>
#include <errno.h>
#include <sys/stat.h>

#include "libsysfs/sysfs/libsysfs.h"
#include "udev_version.h"
#include "udev_sysfs.h"
#include "udev_utils.h"
#include "logging.h"

/* list of subsystem specific files, NULL if there is no file to wait for */
static const struct subsystem_file {
      const char *subsystem;
      const char *file;
} subsystem_files[] = {
      { .subsystem = "class",       .file = NULL },
      { .subsystem = "net",         .file = "ifindex" },
      { .subsystem = "scsi_host",   .file = "unique_id" },
      { .subsystem = "scsi_device", .file = NULL },
      { .subsystem = "pcmcia_socket",     .file = "card_type" },
      { .subsystem = "usb_host",    .file = NULL },
      { .subsystem = "bluetooth",   .file = "address" },
      { .subsystem = "firmware",    .file = "data" },
      { .subsystem = "i2c-adapter", .file = NULL },
      { .subsystem = "pci_bus",     .file = NULL },
      { .subsystem = "ieee1394",    .file = NULL },
      { .subsystem = "ieee1394_host",     .file = NULL },
      { .subsystem = "ieee1394_node",     .file = NULL },
      { .subsystem = "fc_transport",      .file = "port_id" },
      { .subsystem = "fc_host",     .file = "port_id" },
      { .subsystem = "spi_transport",     .file = "width" },
      { .subsystem = "spi_host",    .file = "width" },
      { NULL, NULL }
};

dev_t get_devt(struct sysfs_class_device *class_dev)
{
      struct sysfs_attribute *attr = NULL;
      unsigned int major, minor;

      attr = sysfs_get_classdev_attr(class_dev, "dev");
      if (attr == NULL)
            return 0;
      dbg("dev='%s'", attr->value);

      if (sscanf(attr->value, "%u:%u", &major, &minor) != 2)
            return 0;
      dbg("found major=%d, minor=%d", major, minor);

      return makedev(major, minor);
}

int subsystem_expect_no_dev(const char *subsystem)
{
      const struct subsystem_file *file;

      for (file = subsystem_files; file->subsystem != NULL; file++)
            if (strcmp(subsystem, file->subsystem) == 0)
                  return 1;

      return 0;
}

/* get subsystem specific files, returns "dev" if no other found */
static const char *get_subsystem_specific_file(const char *subsystem)
{
      const struct subsystem_file *file;

      /* look if we want to look for another file instead of "dev" */
      for (file = subsystem_files; file->subsystem != NULL; file++)
            if (strcmp(subsystem, file->subsystem) == 0)
                  return file->file;

      return "dev";
}

/* wait for class pecific file to show up */
static int wait_for_class_device_attributes(struct sysfs_class_device *class_dev,
                                  const char **error)
{
      const char *file;
      char filename[PATH_SIZE];
      int loop;

      file = get_subsystem_specific_file(class_dev->classname);
      if (file == NULL) {
            dbg("class '%s' has no file to wait for", class_dev->classname);
            return 0;
      }

      snprintf(filename, sizeof(filename), "%s/%s", class_dev->path, file);
      filename[sizeof(filename)-1] = '\0';
      dbg("looking at class '%s' for specific file '%s'", class_dev->classname, filename);

      loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND;
      while (--loop) {
            struct stat stats;

            if (stat(class_dev->path, &stats) == -1) {
                  dbg("'%s' now disappeared (probably remove has beaten us)", class_dev->path);
                  return -ENODEV;
            }

            if (stat(filename, &stats) == 0) {
                  dbg("class '%s' specific file '%s' found", class_dev->classname, file);
                  return 0;
            }

            usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND);
      }

      dbg("error: getting class '%s' specific file '%s'", class_dev->classname, file);
      if (error)
            *error = "class specific file unavailable";
      return -ENOENT;
}

/* check if we need to wait for a physical device */
static int class_device_expect_no_device_link(struct sysfs_class_device *class_dev)
{
      /* list of devices without a "device" symlink to the physical device
       * if device is set to NULL, no devices in that subsystem has a link */
      static const struct class_device {
            const char *subsystem;
            const char *device;
      } class_device[] = {
            { .subsystem = "block",       .device = "double" },
            { .subsystem = "block",       .device = "nb" },
            { .subsystem = "block",       .device = "ram" },
            { .subsystem = "block",       .device = "loop" },
            { .subsystem = "block",       .device = "fd" },
            { .subsystem = "block",       .device = "md" },
            { .subsystem = "block",       .device = "dos_cd" },
            { .subsystem = "block",       .device = "rflash" },
            { .subsystem = "block",       .device = "rom" },
            { .subsystem = "block",       .device = "rrom" },
            { .subsystem = "block",       .device = "flash" },
            { .subsystem = "block",       .device = "msd" },
            { .subsystem = "block",       .device = "sbpcd" },
            { .subsystem = "block",       .device = "pcd" },
            { .subsystem = "block",       .device = "pf" },
            { .subsystem = "block",       .device = "scd" },
            { .subsystem = "block",       .device = "ubd" },
            { .subsystem = "block",       .device = "dm-" },
            { .subsystem = "block",       .device = "bcrypt" },
            { .subsystem = "input",       .device = "event" },
            { .subsystem = "input",       .device = "mice" },
            { .subsystem = "input",       .device = "mouse" },
            { .subsystem = "input",       .device = "ts" },
            { .subsystem = "input",       .device = "js" },
            { .subsystem = "vc",          .device = NULL },
            { .subsystem = "tty",         .device = NULL },
            { .subsystem = "cpuid",       .device = "cpu" },
            { .subsystem = "graphics",    .device = "fb" },
            { .subsystem = "mem",         .device = NULL },
            { .subsystem = "misc",        .device = NULL },
            { .subsystem = "msr",         .device = NULL },
            { .subsystem = "netlink",     .device = NULL },
            { .subsystem = "net",         .device = "sit" },
            { .subsystem = "net",         .device = "lo" },
            { .subsystem = "net",         .device = "tap" },
            { .subsystem = "net",         .device = "ipsec" },
            { .subsystem = "net",         .device = "dummy" },
            { .subsystem = "net",         .device = "irda" },
            { .subsystem = "net",         .device = "ppp" },
            { .subsystem = "net",         .device = "tun" },
            { .subsystem = "net",         .device = "pan" },
            { .subsystem = "net",         .device = "bnep" },
            { .subsystem = "net",         .device = "vmnet" },
            { .subsystem = "net",         .device = "ippp" },
            { .subsystem = "net",         .device = "nlv" },
            { .subsystem = "net",         .device = "atml" },
            { .subsystem = "ppp",         .device = NULL },
            { .subsystem = "sound",       .device = NULL },
            { .subsystem = "printer",     .device = "lp" },
            { .subsystem = "ppdev",       .device = NULL },
            { .subsystem = "nvidia",      .device = NULL },
            { .subsystem = "video4linux", .device = "vbi" },
            { .subsystem = "dvb",         .device = NULL },
            { .subsystem = "lirc",        .device = NULL },
            { .subsystem = "firmware",    .device = NULL },
            { .subsystem = "drm",         .device = NULL },
            { .subsystem = "pci_bus",     .device = NULL },
            { .subsystem = "ieee1394",    .device = NULL },
            { .subsystem = "ieee1394_host",     .device = NULL },
            { .subsystem = "ieee1394_node",     .device = NULL },
            { .subsystem = "raw",         .device = NULL },
            { .subsystem = "zaptel",      .device = NULL },
            { .subsystem = "tiglusb",     .device = NULL },
            { .subsystem = "ppdev",       .device = NULL },
            { .subsystem = "ticables",    .device = NULL },
            { .subsystem = "snsc",        .device = NULL },
            { .subsystem = "staliomem",   .device = NULL },
            { .subsystem = "tape",        .device = NULL },
            { .subsystem = "ip2",         .device = NULL },
            { .subsystem = "tpqic02",     .device = NULL },
            { .subsystem = "dsp56k",      .device = NULL },
            { .subsystem = "zft",         .device = NULL },
            { .subsystem = "adb",         .device = NULL },
            { .subsystem = "cosa",        .device = NULL },
            { .subsystem = "pg",          .device = NULL },
            { .subsystem = "pt",          .device = NULL },
            { .subsystem = "capi",        .device = NULL },
            { NULL, NULL }
      };
      const struct class_device *classdevice;
      unsigned int len;

      /* the kernel may tell us what to wait for */
      if (kernel_release_satisfactory(2,6,10) > 0)
            if (getenv("PHYSDEVPATH") == NULL) {
                  dbg("the kernel says, that there is no physical device for '%s'", class_dev->path);
                  return 1;
            }

      for (classdevice = class_device; classdevice->subsystem != NULL; classdevice++) {
            if (strcmp(class_dev->classname, classdevice->subsystem) == 0) {
                  /* see if no device in this class is expected to have a device-link */
                  if (classdevice->device == NULL)
                        return 1;

                  len = strlen(classdevice->device);

                  /* see if device name matches */
                  if (strncmp(class_dev->name, classdevice->device, len) != 0)
                        continue;

                  /* exact name match */
                  if (strlen(class_dev->name) == len)
                        return 1;

                  /* name match with instance number */
                  if (isdigit(class_dev->name[len]))
                        return 1;
            }
      }

      return 0;
}

/* skip waiting for the bus of the devices device */
static int class_device_expect_no_bus(struct sysfs_class_device *class_dev)
{
      static const char *devices_without_bus[] = {
            "scsi_host",
            "i2c-adapter",
            "i2c-dev",
            NULL
      };
      const char **device;

      for (device = devices_without_bus; *device != NULL; device++) {
            int len = strlen(*device);

            if (strncmp(class_dev->classname, *device, len) == 0)
                  return 1;
      }

      return 0;
}

/* wait for a devices device specific file to show up */
int wait_for_devices_device(struct sysfs_device *devices_dev,
                  const char **error)
{
      static const struct device_file {
            const char *bus;
            const char *file;
      } device_files[] = {
            { .bus = "scsi",  .file = "vendor" },
            { .bus = "usb",         .file = "idVendor" },
            { .bus = "usb",         .file = "iInterface" },
            { .bus = "usb",         .file = "bNumEndpoints" },
            { .bus = "usb-serial",  .file = "detach_state" },
            { .bus = "ide",         .file = "detach_state" },
            { .bus = "pci",         .file = "vendor" },
            { .bus = "platform",    .file = "detach_state" },
            { .bus = "pcmcia",      .file = "detach_state" },
            { .bus = "i2c",         .file = "detach_state" },
            { .bus = "ieee1394",    .file = "node_count" },
            { .bus = "ieee1394",    .file = "nodeid" },
            { .bus = "ieee1394",    .file = "address" },
            { .bus = "bttv-sub",    .file = NULL },
            { .bus = "pnp",         .file = "detach_state" },
            { .bus = "eisa",  .file = "detach_state" },
            { .bus = "serio", .file = "detach_state" },
            { .bus = "pseudo",      .file = "detach_state" },
            { .bus = "mmc",         .file = "detach_state" },
            { .bus = "macio", .file = "detach_state" },
            { .bus = "of_platform", .file = "detach_state" },
            { .bus = "vio",         .file = "detach_state" },
            { .bus = "ecard", .file = "detach_state" },
            { .bus = "sa1111-rab",  .file = "detach_state" },
            { .bus = "amba",  .file = "detach_state" },
            { .bus = "locomo-bus",  .file = "detach_state" },
            { .bus = "logicmodule", .file = "detach_state" },
            { .bus = "parisc",      .file = "detach_state" },
            { .bus = "ocp",         .file = "detach_state" },
            { .bus = "dio",         .file = "detach_state" },
            { .bus = "MCA",         .file = "detach_state" },
            { .bus = "wl",          .file = "detach_state" },
            { .bus = "ccwgroup",    .file = "detach_state" },
            { .bus = "css",         .file = "detach_state" },
            { .bus = "ccw",         .file = "detach_state" },
            { .bus = "iucv",  .file = "detach_state" },
            { NULL, NULL }
      };
      const struct device_file *devicefile = NULL;
      int loop;

      /* the kernel may tell us what to wait for */
      if (kernel_release_satisfactory(2,6,10) > 0)
            if (getenv("PHYSDEVBUS") == NULL) {
                  dbg("the kernel says, that there is no bus for '%s'", devices_dev->path);
                  return 0;
            }

      /* wait for the bus device link to the devices device */
      loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND;
      while (--loop) {
            if (sysfs_get_device_bus(devices_dev) == 0)
                  break;

            usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND);
      }
      if (loop == 0) {
            dbg("error: getting bus device link");
            if (error)
                  *error = "no bus device link";
            return -1;
      }
      dbg("bus device link found for bus '%s'", devices_dev->bus);

      /* wait for a bus device specific file to show up */
      loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND;
      while (--loop) {
            int found_bus_type = 0;

            for (devicefile = device_files; devicefile->bus != NULL; devicefile++) {
                  if (strcmp(devices_dev->bus, devicefile->bus) == 0) {
                        char filename[PATH_SIZE];
                        struct stat stats;

                        if (devicefile->file == NULL) {
                              dbg("bus '%s' has no file to wait for", devices_dev->bus);
                              return 0;
                        }

                        found_bus_type = 1;
                        snprintf(filename, sizeof(filename), "%s/%s", devices_dev->path, devicefile->file);
                        filename[sizeof(filename)-1] = '\0';
                        dbg("looking at bus '%s' device for specific file '%s'", devices_dev->bus, filename);

                        if (stat(filename, &stats) == 0) {
                              dbg("bus '%s' device specific file '%s' found", devices_dev->bus, devicefile->file);
                              return 0;
                        }
                  }
            }
            if (found_bus_type == 0) {
                  if (error)
                        *error = "unknown bus";
                  info("error: unknown bus, please report to "
                       "<linux-hotplug-devel@lists.sourceforge.net> '%s'", devices_dev->bus);
                  return -1;
            }
            usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND);
      }

      dbg("error: getting '%s' device specific file '%s'", devices_dev->bus, devicefile->file);
      if (error)
            *error = "bus device specific file unavailable";
      return -1;
}


struct sysfs_class_device *wait_class_device_open(const char *path)
{
      struct sysfs_class_device *class_dev = NULL;
      int loop;

      loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND;
      while (--loop) {
            class_dev = sysfs_open_class_device_path(path);
            if (class_dev)
                  break;

            usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND);
      }

      return class_dev;
}

int wait_for_class_device(struct sysfs_class_device *class_dev,
                    const char **error)
{
      struct sysfs_class_device *class_dev_parent;
      struct sysfs_device *devices_dev = NULL;
      int loop;

      if (wait_for_class_device_attributes(class_dev, error) != 0)
            return -ENOENT;

      /* skip devices without devices-link */
      if (class_device_expect_no_device_link(class_dev)) {
            dbg("no device symlink expected for '%s', ", class_dev->name);
            return 0;
      }

      /* the symlink may be on the parent device */
      class_dev_parent = sysfs_get_classdev_parent(class_dev);
      if (class_dev_parent)
            dbg("looking at parent device for device link '%s'", class_dev_parent->path);

      /* wait for the symlink to the devices device */
      dbg("waiting for symlink to devices device");
      loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND;
      while (--loop) {
            if (class_dev_parent)
                  devices_dev = sysfs_get_classdev_device(class_dev_parent);
            else
                  devices_dev = sysfs_get_classdev_device(class_dev);

            if (devices_dev)
                  break;

            usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND);
      }
      if (!devices_dev) {
            dbg(" error: no devices device symlink found");
            if (error)
                  *error = "no device symlink";
            return -ENODEV;
      }
      dbg("device symlink found pointing to '%s'", devices_dev->path);

      /* wait for the devices device */
      if (class_device_expect_no_bus(class_dev)) {
            dbg("no bus device expected for '%s', ", class_dev->classname);
            return 0;
      }

      return wait_for_devices_device(devices_dev, error);
}

struct sysfs_device *wait_devices_device_open(const char *path)
{
      struct sysfs_device *devices_dev = NULL;
      int loop;

      loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND;
      while (--loop) {
            devices_dev = sysfs_open_device_path(path);
            if (devices_dev)
                  break;

            usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND);
      }

      return devices_dev;
}

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