udev-add.c

   1 /*
   2  * udev-add.c
   3  *
   4  * Userspace devfs
   5  *
   6  * Copyright (C) 2003 Greg Kroah-Hartman <greg@kroah.com>
   7  *
   8  *
   9  *      This program is free software; you can redistribute it and/or modify it
  10  *      under the terms of the GNU General Public License as published by the
  11  *      Free Software Foundation version 2 of the License.
  12  *
  13  *      This program is distributed in the hope that it will be useful, but
  14  *      WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  *      General Public License for more details.
  17  *
  18  *      You should have received a copy of the GNU General Public License along
  19  *      with this program; if not, write to the Free Software Foundation, Inc.,
  20  *      675 Mass Ave, Cambridge, MA 02139, USA.
  21  *
  22  */
  23
  24 #include <stdlib.h>
  25 #include <string.h>
  26 #include <stdio.h>
  27 #include <fcntl.h>
  28 #include <unistd.h>
  29 #include <errno.h>
  30 #include <sys/stat.h>
  31 #include <sys/types.h>
  32 #include <grp.h>
  33 #ifndef __KLIBC__
  34 #include <pwd.h>
  35 #endif
  36
  37 #include "udev.h"
  38 #include "udev_version.h"
  39 #include "udev_dbus.h"
  40 #include "logging.h"
  41 #include "namedev.h"
  42 #include "udevdb.h"
  43 #include "libsysfs/libsysfs.h"
  44 #include "klibc_fixups.h"
  45
  46 /*
  47  * Right now the major/minor of a device is stored in a file called
  48  * "dev" in sysfs.
  49  * The number is stored as:
  50  *      MM:mm
  51  *              MM is the major
  52  *              mm is the minor
  53  *              The value is in decimal.
  54  */
  55 static int get_major_minor(struct sysfs_class_device *class_dev, struct udevice *udev)
  56 {
  57         int retval = -ENODEV;
  58         struct sysfs_attribute *attr = NULL;
  59
  60         attr = sysfs_get_classdev_attr(class_dev, "dev");
  61         if (attr == NULL)
  62                 goto exit;
  63         dbg("dev='%s'", attr->value);
  64
  65         if (sscanf(attr->value, "%u:%u", &udev->major, &udev->minor) != 2)
  66                 goto exit;
  67         dbg("found major=%d, minor=%d", udev->major, udev->minor);
  68
  69         retval = 0;
  70 exit:
  71         return retval;
  72 }
  73
  74 static int create_path(char *file)
  75 {
  76         char p[NAME_SIZE];
  77         char *pos;
  78         int retval;
  79         struct stat stats;
  80
  81         strncpy(p, file, sizeof(p));
  82         pos = strchr(p+1, '/');
  83         while (1) {
  84                 pos = strchr(pos+1, '/');
  85                 if (pos == NULL)
  86                         break;
  87                 *pos = 0x00;
  88                 if (stat(p, &stats)) {
  89                         retval = mkdir(p, 0755);
  90                         if (retval) {
  91                                 dbg("mkdir(%s) failed with error '%s'",
  92                                     p, strerror(errno));
  93                                 return retval;
  94                         }
  95                         dbg("created '%s'", p);
  96                 }
  97                 *pos = '/';
  98         }
  99         return 0;
 100 }
 101
 102 static int create_node(struct udevice *dev)
 103 {
 104         struct stat stats;
 105         char filename[255];
 106         char linktarget[255];
 107         char *linkname;
 108         char *symlinks;
 109         int retval = 0;
 110         uid_t uid = 0;
 111         gid_t gid = 0;
 112         dev_t res;
 113         int i;
 114         int tail;
 115
 116         strncpy(filename, udev_root, sizeof(filename));
 117         strncat(filename, dev->name, sizeof(filename));
 118
 119 #ifdef __KLIBC__
 120         res = (dev->major << 8) | (dev->minor);
 121 #else
 122         res = makedev(dev->major, dev->minor);
 123 #endif
 124
 125         switch (dev->type) {
 126         case 'b':
 127                 dev->mode |= S_IFBLK;
 128                 break;
 129         case 'c':
 130         case 'u':
 131                 dev->mode |= S_IFCHR;
 132                 break;
 133         case 'p':
 134                 dev->mode |= S_IFIFO;
 135                 break;
 136         default:
 137                 dbg("unknown node type %c\n", dev->type);
 138                 return -EINVAL;
 139         }
 140
 141         /* create parent directories if needed */
 142         if (strrchr(dev->name, '/'))
 143                 create_path(filename);
 144
 145         info("creating device node '%s'", filename);
 146         dbg("mknod(%s, %#o, %u, %u)", filename, dev->mode, dev->major, dev->minor);
 147         retval = mknod(filename, dev->mode, res);
 148         if (retval)
 149                 dbg("mknod(%s, %#o, %u, %u) failed with error '%s'",
 150                     filename, dev->mode, dev->major, dev->minor, strerror(errno));
 151
 152         dbg("chmod(%s, %#o)", filename, dev->mode);
 153         retval = chmod(filename, dev->mode);
 154         if (retval)
 155                 dbg("chmod(%s, %#o) failed with error '%s'",
 156                     filename, dev->mode, strerror(errno));
 157
 158         if (dev->owner[0]) {
 159                 char *endptr;
 160                 unsigned long id = strtoul(dev->owner, &endptr, 10);
 161                 if (endptr[0] == '\0')
 162                         uid = (uid_t) id;
 163                 else {
 164                         struct passwd *pw = getpwnam(dev->owner);
 165                         if (pw == NULL)
 166                                 dbg("specified user unknown '%s'", dev->owner);
 167                         else
 168                                 uid = pw->pw_uid;
 169                 }
 170         }
 171
 172         if (dev->group[0]) {
 173                 char *endptr;
 174                 unsigned long id = strtoul(dev->group, &endptr, 10);
 175                 if (endptr[0] == '\0')
 176                         gid = (gid_t) id;
 177                 else {
 178                         struct group *gr = getgrnam(dev->group);
 179                         if (gr == NULL)
 180                                 dbg("specified group unknown '%s'", dev->group);
 181                         else
 182                                 gid = gr->gr_gid;
 183                 }
 184         }
 185
 186         if (uid || gid) {
 187                 dbg("chown(%s, %u, %u)", filename, uid, gid);
 188                 retval = chown(filename, uid, gid);
 189                 if (retval)
 190                         dbg("chown(%s, %u, %u) failed with error '%s'",
 191                             filename, uid, gid, strerror(errno));
 192         }
 193
 194         /* create symlink if requested */
 195         if (dev->symlink[0]) {
 196                 symlinks = dev->symlink;
 197                 while (1) {
 198                         linkname = strsep(&symlinks, " ");
 199                         if (linkname == NULL || linkname[0] == '\0')
 200                                 break;
 201
 202                         strncpy(filename, udev_root, sizeof(filename));
 203                         strncat(filename, linkname, sizeof(filename));
 204                         dbg("symlink '%s' to node '%s' requested", filename, dev->name);
 205                         if (strrchr(linkname, '/'))
 206                                 create_path(filename);
 207
 208                         /* optimize relative link */
 209                         linktarget[0] = '\0';
 210                         i = 0;
 211                         tail = 0;
 212                         while ((dev->name[i] == linkname[i]) && dev->name[i]) {
 213                                 if (dev->name[i] == '/')
 214                                         tail = i+1;
 215                                 i++;
 216                         }
 217                         while (linkname[i]) {
 218                                 if (linkname[i] == '/')
 219                                         strcat(linktarget, "../");
 220                                 i++;
 221                         }
 222
 223                         if (*linktarget == '\0')
 224                                 strcpy(linktarget, "./");
 225                         strcat(linktarget, &dev->name[tail]);
 226
 227                         /* unlink existing non-directories to ensure that our symlink
 228                          * is created */
 229                         if (lstat(filename, &stats) == 0) {
 230                                 if ((stats.st_mode & S_IFMT) != S_IFDIR) {
 231                                         if (unlink(filename))
 232                                                 dbg("unlink(%s) failed with error '%s'",
 233                                                     filename, strerror(errno));
 234                                 }
 235                         }
 236
 237                         dbg("symlink(%s, %s)", linktarget, filename);
 238                         retval = symlink(linktarget, filename);
 239                         if (retval)
 240                                 dbg("symlink(%s, %s) failed with error '%s'",
 241                                     linktarget, filename, strerror(errno));
 242                 }
 243         }
 244
 245         return retval;
 246 }
 247
 248 static struct sysfs_class_device *get_class_dev(char *device_name)
 249 {
 250         char dev_path[SYSFS_PATH_MAX];
 251         struct sysfs_class_device *class_dev = NULL;
 252
 253         strcpy(dev_path, sysfs_path);
 254         strcat(dev_path, device_name);
 255         dbg("looking at '%s'", dev_path);
 256
 257         /* open up the sysfs class device for this thing... */
 258         class_dev = sysfs_open_class_device_path(dev_path);
 259         if (class_dev == NULL) {
 260                 dbg ("sysfs_open_class_device_path failed");
 261                 goto exit;
 262         }
 263         dbg("class_dev->name='%s'", class_dev->name);
 264
 265 exit:
 266         return class_dev;
 267 }
 268
 269 /* wait for the "dev" file to show up in the directory in sysfs.
 270  * If it doesn't happen in about 10 seconds, give up.
 271  */
 272 #define SECONDS_TO_WAIT_FOR_DEV         10
 273 static int sleep_for_dev(char *path)
 274 {
 275         char filename[SYSFS_PATH_MAX + 6];
 276         int loop = SECONDS_TO_WAIT_FOR_DEV;
 277         int retval;
 278
 279         strcpy(filename, sysfs_path);
 280         strcat(filename, path);
 281         strcat(filename, "/dev");
 282
 283         while (loop--) {
 284                 struct stat buf;
 285
 286                 dbg("looking for '%s'", filename);
 287                 retval = stat(filename, &buf);
 288                 if (!retval)
 289                         goto exit;
 290
 291                 /* sleep to give the kernel a chance to create the dev file */
 292                 sleep(1);
 293         }
 294         retval = -ENODEV;
 295 exit:
 296         return retval;
 297 }
 298
 299 int udev_add_device(char *path, char *subsystem)
 300 {
 301         struct sysfs_class_device *class_dev = NULL;
 302         struct udevice dev;
 303         int retval = -EINVAL;
 304
 305         memset(&dev, 0x00, sizeof(dev));
 306
 307         /* for now, the block layer is the only place where block devices are */
 308         if (strcmp(subsystem, "block") == 0)
 309                 dev.type = 'b';
 310         else
 311                 dev.type = 'c';
 312
 313         retval = sleep_for_dev(path);
 314         if (retval)
 315                 goto exit;
 316
 317         class_dev = get_class_dev(path);
 318         if (class_dev == NULL)
 319                 goto exit;
 320
 321         retval = get_major_minor(class_dev, &dev);
 322         if (retval) {
 323                 dbg("get_major_minor failed");
 324                 goto exit;
 325         }
 326
 327         retval = namedev_name_device(class_dev, &dev);
 328         if (retval)
 329                 goto exit;
 330
 331         retval = udevdb_add_dev(path, &dev);
 332         if (retval != 0)
 333                 dbg("udevdb_add_dev failed, but we are going to try to create the node anyway. "
 334                     "But remove might not work properly for this device.");
 335
 336         dbg("name='%s'", dev.name);
 337         retval = create_node(&dev);
 338
 339         if (retval == 0)
 340                 sysbus_send_create(&dev, path);
 341
 342 exit:
 343         if (class_dev)
 344                 sysfs_close_class_device(class_dev);
 345
 346         return retval;
 347 }