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 "namedev.h"
  40 #include "udevdb.h"
  41 #include "libsysfs/libsysfs.h"
  42 #include "klibc_fixups.h"
  43
  44 /*
  45  * Right now the major/minor of a device is stored in a file called
  46  * "dev" in sysfs.
  47  * The number is stored as:
  48  *      MM:mm
  49  *              MM is the major
  50  *              mm is the minor
  51  *              The value is in decimal.
  52  */
  53 static int get_major_minor(struct sysfs_class_device *class_dev, struct udevice *udev)
  54 {
  55         int retval = -ENODEV;
  56
  57         char *dev;
  58
  59         dev = sysfs_get_value_from_attributes(class_dev->directory->attributes, "dev");
  60         if (dev == NULL)
  61                 goto exit;
  62
  63         dbg("dev='%s'", dev);
  64
  65         if (sscanf(dev, "%u:%u", &udev->major, &udev->minor) != 2)
  66                 goto exit;
  67
  68         dbg("found major=%d, minor=%d", udev->major, udev->minor);
  69
  70         retval = 0;
  71 exit:
  72         return retval;
  73 }
  74
  75 static int create_path(char *file)
  76 {
  77         char p[NAME_SIZE];
  78         char *pos;
  79         int retval;
  80         struct stat stats;
  81
  82         strncpy(p, file, sizeof(p));
  83         pos = strchr(p+1, '/');
  84         while (1) {
  85                 pos = strchr(pos+1, '/');
  86                 if (pos == NULL)
  87                         break;
  88                 *pos = 0x00;
  89                 if (stat(p, &stats)) {
  90                         retval = mkdir(p, 0755);
  91                         if (retval) {
  92                                 dbg("mkdir(%s) failed with error '%s'",
  93                                     p, strerror(errno));
  94                                 return retval;
  95                         }
  96                         dbg("created '%s'", p);
  97                 }
  98                 *pos = '/';
  99         }
 100         return 0;
 101 }
 102
 103 /*
 104  * we possibly want to add some symlinks here
 105  * only numeric owner/group id's are supported
 106  */
 107 static int create_node(struct udevice *dev)
 108 {
 109         char filename[255];
 110         char linktarget[255];
 111         int retval = 0;
 112         uid_t uid = 0;
 113         gid_t gid = 0;
 114         dev_t res;
 115         int i;
 116         int tail;
 117
 118
 119         strncpy(filename, udev_root, sizeof(filename));
 120         strncat(filename, dev->name, sizeof(filename));
 121
 122 #ifdef __KLIBC__
 123         res = (dev->major << 8) | (dev->minor);
 124 #else
 125         res = makedev(dev->major, dev->minor);
 126 #endif
 127
 128         switch (dev->type) {
 129         case 'b':
 130                 dev->mode |= S_IFBLK;
 131                 break;
 132         case 'c':
 133         case 'u':
 134                 dev->mode |= S_IFCHR;
 135                 break;
 136         case 'p':
 137                 dev->mode |= S_IFIFO;
 138                 break;
 139         default:
 140                 dbg("unknown node type %c\n", dev->type);
 141                 return -EINVAL;
 142         }
 143
 144         /* create parent directories if needed */
 145         if (strrchr(dev->name, '/'))
 146                 create_path(filename);
 147
 148         dbg("mknod(%s, %#o, %u, %u)", filename, dev->mode, dev->major, dev->minor);
 149         retval = mknod(filename, dev->mode, res);
 150         if (retval)
 151                 dbg("mknod(%s, %#o, %u, %u) failed with error '%s'",
 152                     filename, dev->mode, dev->major, dev->minor, strerror(errno));
 153
 154         dbg("chmod(%s, %#o)", filename, dev->mode);
 155         retval = chmod(filename, dev->mode);
 156         if (retval)
 157                 dbg("chmod(%s, %#o) failed with error '%s'",
 158                     filename, dev->mode, strerror(errno));
 159
 160         if (*dev->owner) {
 161                 char *endptr;
 162                 unsigned long id = strtoul(dev->owner, &endptr, 10);
 163                 if (*endptr == 0x00)
 164                         uid = (uid_t) id;
 165                 else {
 166                         struct passwd *pw = getpwnam(dev->owner);
 167                         if (!pw)
 168                                 dbg("user unknown '%s'", dev->owner);
 169                         else
 170                                 uid = pw->pw_uid;
 171                 }
 172         }
 173
 174         if (*dev->group) {
 175                 char *endptr;
 176                 unsigned long id = strtoul(dev->group, &endptr, 10);
 177                 if (*endptr == 0x00)
 178                         gid = (gid_t) id;
 179                 else {
 180                         struct group *gr = getgrnam(dev->group);
 181                         if (!gr)
 182                                 dbg("group unknown '%s'", dev->group);
 183                         else
 184                                 gid = gr->gr_gid;
 185                 }
 186         }
 187
 188         if (uid || gid) {
 189                 dbg("chown(%s, %u, %u)", filename, uid, gid);
 190                 retval = chown(filename, uid, gid);
 191                 if (retval)
 192                         dbg("chown(%s, %u, %u) failed with error '%s'",
 193                             filename, uid, gid, strerror(errno));
 194         }
 195
 196
 197         /* create symlink if requested */
 198         if (*dev->symlink) {
 199                 strncpy(filename, udev_root, sizeof(filename));
 200                 strncat(filename, dev->symlink, sizeof(filename));
 201                 dbg("symlink '%s' to node '%s' requested", filename, dev->name);
 202                 if (strrchr(dev->symlink, '/'))
 203                         create_path(filename);
 204
 205                 /* optimize relative link */
 206                 linktarget[0] = '\0';
 207                 i = 0;
 208                 tail = 0;
 209                 while ((dev->name[i] == dev->symlink[i]) && dev->name[i]) {
 210                         if (dev->name[i] == '/')
 211                                 tail = i+1;
 212                         i++;
 213                 }
 214                 while (dev->symlink[i]) {
 215                         if (dev->symlink[i] == '/')
 216                                 strcat(linktarget, "../");
 217                         i++;
 218                 }
 219
 220                 if (*linktarget == '\0')
 221                         strcpy(linktarget, "./");
 222                 strcat(linktarget, &dev->name[tail]);
 223
 224                 dbg("symlink(%s, %s)", linktarget, filename);
 225                 retval = symlink(linktarget, filename);
 226                 if (retval)
 227                         dbg("symlink(%s, %s) failed with error '%s'",
 228                             linktarget, filename, strerror(errno));
 229         }
 230
 231         return retval;
 232 }
 233
 234 static struct sysfs_class_device *get_class_dev(char *device_name)
 235 {
 236         char dev_path[SYSFS_PATH_MAX];
 237         struct sysfs_class_device *class_dev = NULL;
 238
 239         strcpy(dev_path, sysfs_path);
 240         strcat(dev_path, device_name);
 241
 242         dbg("looking at '%s'", dev_path);
 243
 244         /* open up the sysfs class device for this thing... */
 245         class_dev = sysfs_open_class_device(dev_path);
 246         if (class_dev == NULL) {
 247                 dbg ("sysfs_open_class_device failed");
 248                 goto exit;
 249         }
 250         dbg("class_dev->name='%s'", class_dev->name);
 251
 252 exit:
 253         return class_dev;
 254 }
 255
 256 /* wait for the "dev" file to show up in the directory in sysfs.
 257  * If it doesn't happen in about 10 seconds, give up.
 258  */
 259 #define SECONDS_TO_WAIT_FOR_DEV         10
 260 static int sleep_for_dev(char *path)
 261 {
 262         char filename[SYSFS_PATH_MAX + 6];
 263         int loop = SECONDS_TO_WAIT_FOR_DEV;
 264         int retval;
 265
 266         strcpy(filename, sysfs_path);
 267         strcat(filename, path);
 268         strcat(filename, "/dev");
 269
 270         while (loop--) {
 271                 struct stat buf;
 272
 273                 dbg("looking for '%s'", filename);
 274                 retval = stat(filename, &buf);
 275                 if (!retval)
 276                         goto exit;
 277
 278                 /* sleep to give the kernel a chance to create the dev file */
 279                 sleep(1);
 280         }
 281         retval = -ENODEV;
 282 exit:
 283         return retval;
 284 }
 285
 286 int udev_add_device(char *path, char *subsystem)
 287 {
 288         struct sysfs_class_device *class_dev = NULL;
 289         struct udevice dev;
 290         int retval = -EINVAL;
 291
 292         memset(&dev, 0x00, sizeof(dev));
 293
 294         /* for now, the block layer is the only place where block devices are */
 295         if (strcmp(subsystem, "block") == 0)
 296                 dev.type = 'b';
 297         else
 298                 dev.type = 'c';
 299
 300         retval = sleep_for_dev(path);
 301         if (retval)
 302                 goto exit;
 303
 304         class_dev = get_class_dev(path);
 305         if (class_dev == NULL)
 306                 goto exit;
 307
 308         retval = get_major_minor(class_dev, &dev);
 309         if (retval) {
 310                 dbg("get_major_minor failed");
 311                 goto exit;
 312         }
 313
 314         retval = namedev_name_device(class_dev, &dev);
 315         if (retval)
 316                 goto exit;
 317
 318         retval = udevdb_add_dev(path, &dev);
 319         if (retval != 0)
 320                 dbg("udevdb_add_dev failed, but we are going to try to create the node anyway. "
 321                     "But remove might not work properly for this device.");
 322
 323         dbg("name='%s'", dev.name);
 324         retval = create_node(&dev);
 325
 326 exit:
 327         if (class_dev)
 328                 sysfs_close_class_device(class_dev);
 329
 330         return retval;
 331 }