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Sourcecode: udev version File versions

udev_add.c

/*
 * udev-add.c
 *
 * Userspace devfs
 *
 * Copyright (C) 2003 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 <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <grp.h>
#include <net/if.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <linux/sockios.h>

#include "libsysfs/sysfs/libsysfs.h"
#include "udev_libc_wrapper.h"
#include "udev.h"
#include "udev_utils.h"
#include "udev_sysfs.h"
#include "udev_version.h"
#include "logging.h"
#include "udev_rules.h"
#include "udev_db.h"
#include "udev_selinux.h"


int udev_make_node(struct udevice *udev, const char *file, dev_t devt, mode_t mode, uid_t uid, gid_t gid)
{
      struct stat stats;
      int retval = 0;

      if (stat(file, &stats) != 0)
            goto create;

      /* preserve node with already correct numbers, to not change the inode number */
      if (((stats.st_mode & S_IFMT) == S_IFBLK || (stats.st_mode & S_IFMT) == S_IFCHR) &&
          (stats.st_rdev == devt)) {
            dbg("preserve file '%s', cause it has correct dev_t", file);
            selinux_setfilecon(file, udev->kernel_name, stats.st_mode);
            goto perms;
      }

      if (unlink(file) != 0)
            dbg("unlink(%s) failed with error '%s'", file, strerror(errno));
      else
            dbg("already present file '%s' unlinked", file);

create:
      switch (udev->type) {
      case DEV_BLOCK:
            mode |= S_IFBLK;
            break;
      case DEV_CLASS:
            mode |= S_IFCHR;
            break;
      default:
            dbg("unknown node type %c\n", udev->type);
            return -EINVAL;
      }

      selinux_setfscreatecon(file, udev->kernel_name, mode);
      retval = mknod(file, mode, devt);
      selinux_resetfscreatecon();
      if (retval != 0) {
            dbg("mknod(%s, %#o, %u, %u) failed with error '%s'",
                file, mode, major(devt), minor(devt), strerror(errno));
            goto exit;
      }

perms:
      dbg("chmod(%s, %#o)", file, mode);
      if (chmod(file, mode) != 0) {
            dbg("chmod(%s, %#o) failed with error '%s'", file, mode, strerror(errno));
            goto exit;
      }

      if (uid != 0 || gid != 0) {
            dbg("chown(%s, %u, %u)", file, uid, gid);
            if (chown(file, uid, gid) != 0) {
                  dbg("chown(%s, %u, %u) failed with error '%s'",
                      file, uid, gid, strerror(errno));
                  goto exit;
            }
      }

exit:
      return retval;
}

static int create_node(struct udevice *udev, struct sysfs_class_device *class_dev)
{
      char filename[PATH_SIZE];
      char partitionname[PATH_SIZE];
      struct name_entry *name_loop;
      uid_t uid;
      gid_t gid;
      int tail;
      int i;

      snprintf(filename, sizeof(filename), "%s/%s", udev_root, udev->name);
      filename[sizeof(filename)-1] = '\0';

      /* create parent directories if needed */
      if (strchr(udev->name, '/'))
            create_path(filename);

      if (strcmp(udev->owner, "root") == 0)
            uid = 0;
      else {
            char *endptr;
            unsigned long id;

            id = strtoul(udev->owner, &endptr, 10);
            if (endptr[0] == '\0')
                  uid = (uid_t) id;
            else
                  uid = lookup_user(udev->owner);
      }

      if (strcmp(udev->group, "root") == 0)
            gid = 0;
      else {
            char *endptr;
            unsigned long id;

            id = strtoul(udev->group, &endptr, 10);
            if (endptr[0] == '\0')
                  gid = (gid_t) id;
            else
                  gid = lookup_group(udev->group);
      }

      if (!udev->test_run) {
            info("creating device node '%s'", filename);
            if (udev_make_node(udev, filename, udev->devt, udev->mode, uid, gid) != 0)
                  goto error;
      } else {
            info("creating device node '%s', major = '%d', minor = '%d', "
                 "mode = '%#o', uid = '%d', gid = '%d'", filename,
                 major(udev->devt), minor(udev->devt), udev->mode, uid, gid);
      }

      /* create all_partitions if requested */
      if (udev->partitions) {
            struct sysfs_attribute *attr;
            int range;

            /* take the maximum registered minor range */
            attr = sysfs_get_classdev_attr(class_dev, "range");
            if (attr) {
                  range = atoi(attr->value);
                  if (range > 1)
                        udev->partitions = range-1;
            }
            info("creating device partition nodes '%s[1-%i]'", filename, udev->partitions);
            if (!udev->test_run) {
                  for (i = 1; i <= udev->partitions; i++) {
                        dev_t part_devt;

                        snprintf(partitionname, sizeof(partitionname), "%s%d", filename, i);
                        partitionname[sizeof(partitionname)-1] = '\0';
                        part_devt = makedev(major(udev->devt), minor(udev->devt)+1);
                        udev_make_node(udev, partitionname, part_devt, udev->mode, uid, gid);
                  }
            }
      }

      /* create symlink(s) if requested */
      list_for_each_entry(name_loop, &udev->symlink_list, node) {
            int retval;
            char linktarget[PATH_SIZE];

            snprintf(filename, sizeof(filename), "%s/%s", udev_root, name_loop->name);
            filename[sizeof(filename)-1] = '\0';

            dbg("symlink '%s' to node '%s' requested", filename, udev->name);
            if (!udev->test_run)
                  if (strchr(filename, '/'))
                        create_path(filename);

            /* optimize relative link */
            linktarget[0] = '\0';
            i = 0;
            tail = 0;
            while (udev->name[i] && (udev->name[i] == name_loop->name[i])) {
                  if (udev->name[i] == '/')
                        tail = i+1;
                  i++;
            }
            while (name_loop->name[i] != '\0') {
                  if (name_loop->name[i] == '/')
                        strlcat(linktarget, "../", sizeof(linktarget));
                  i++;
            }

            strlcat(linktarget, &udev->name[tail], sizeof(linktarget));

            dbg("symlink(%s, %s)", linktarget, filename);
            if (!udev->test_run) {
                  unlink(filename);
                  selinux_setfscreatecon(filename, udev->kernel_name, S_IFLNK);
                  retval = symlink(linktarget, filename);
                  selinux_resetfscreatecon();
                  if (retval != 0)
                        dbg("symlink(%s, %s) failed with error '%s'",
                            linktarget, filename, strerror(errno));
            }
      }

      return 0;
error:
      return -1;
}

static int rename_net_if(struct udevice *udev)
{
      int sk;
      struct ifreq ifr;
      int retval;

      dbg("changing net interface name from '%s' to '%s'", udev->kernel_name, udev->name);
      if (udev->test_run)
            return 0;

      sk = socket(PF_INET, SOCK_DGRAM, 0);
      if (sk < 0) {
            dbg("error opening socket");
            return -1;
      }

      memset(&ifr, 0x00, sizeof(struct ifreq));
      strlcpy(ifr.ifr_name, udev->kernel_name, IFNAMSIZ);
      strlcpy(ifr.ifr_newname, udev->name, IFNAMSIZ);

      retval = ioctl(sk, SIOCSIFNAME, &ifr);
      if (retval != 0)
            dbg("error changing net interface name");
      close(sk);

      return retval;
}

int udev_add_device(struct udevice *udev, struct sysfs_class_device *class_dev)
{
      char *pos;
      int retval = 0;

      if (udev->type == DEV_BLOCK || udev->type == DEV_CLASS) {
            udev->devt = get_devt(class_dev);
            if (!udev->devt) {
                  dbg("no dev-file found, do nothing");
                  return 0;
            }
      }

      if (udev_rules_get_name(udev, class_dev) != 0)
            return 0;

      dbg("adding name='%s'", udev->name);

      selinux_init();

      if (udev->type == DEV_BLOCK || udev->type == DEV_CLASS) {
            retval = create_node(udev, class_dev);
            if (retval != 0)
                  goto exit;

            if (udev_db_add_device(udev) != 0)
                  dbg("udev_db_add_dev failed, but we create the node anyway, "
                      "remove might not work for custom names");

            /* use full path to the environment */
            snprintf(udev->devname, sizeof(udev->devname), "%s/%s", udev_root, udev->name);
            udev->devname[sizeof(udev->devname)-1] = '\0';

      } else if (udev->type == DEV_NET) {
            /* look if we want to change the name of the netif */
            if (strcmp(udev->name, udev->kernel_name) != 0) {
                  retval = rename_net_if(udev);
                  if (retval != 0)
                        goto exit;

                  /* we've changed the name, now fake the devpath, cause the
                   * original kernel name sleeps with the fishes and we don't
                   * get an event from the kernel with the new name
                   */
                  pos = strrchr(udev->devpath, '/');
                  if (pos != NULL) {
                        pos[1] = '\0';
                        strlcat(udev->devpath, udev->name, sizeof(udev->devpath));
                        setenv("DEVPATH", udev->devpath, 1);
                        setenv("INTERFACE", udev->name, 1);
                  }

                  /* use netif name for the environment */
                  strlcpy(udev->devname, udev->name, sizeof(udev->devname));
            }
      }

exit:
      selinux_exit();

      return retval;
}

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