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 != 0) {
  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 make_node(char *filename, int major, int minor, unsigned int mode, uid_t uid, gid_t gid)
 103 {
 104         int retval;
 105
 106         retval = mknod(filename, mode, makedev(major, minor));
 107         if (retval != 0) {
 108                 dbg("mknod(%s, %#o, %u, %u) failed with error '%s'",
 109                     filename, mode, major, minor, strerror(errno));
 110                 return retval;
 111         }
 112
 113         dbg("chmod(%s, %#o)", filename, mode);
 114         retval = chmod(filename, mode);
 115         if (retval != 0) {
 116                 dbg("chmod(%s, %#o) failed with error '%s'",
 117                     filename, mode, strerror(errno));
 118                 return retval;
 119         }
 120
 121         if (uid != 0 || gid != 0) {
 122                 dbg("chown(%s, %u, %u)", filename, uid, gid);
 123                 retval = chown(filename, uid, gid);
 124                 if (retval != 0) {
 125                         dbg("chown(%s, %u, %u) failed with error '%s'",
 126                             filename, uid, gid, strerror(errno));
 127                         return retval;
 128                 }
 129         }
 130
 131         return 0;
 132 }
 133
 134 static int create_node(struct udevice *dev, int fake)
 135 {
 136         struct stat stats;
 137         char filename[255];
 138         char linktarget[255];
 139         char partitionname[255];
 140         char *linkname;
 141         char *symlinks;
 142         int retval = 0;
 143         uid_t uid = 0;
 144         gid_t gid = 0;
 145         int i;
 146         int tail;
 147
 148         strncpy(filename, udev_root, sizeof(filename));
 149         strncat(filename, dev->name, sizeof(filename));
 150
 151         switch (dev->type) {
 152         case 'b':
 153                 dev->mode |= S_IFBLK;
 154                 break;
 155         case 'c':
 156         case 'u':
 157                 dev->mode |= S_IFCHR;
 158                 break;
 159         case 'p':
 160                 dev->mode |= S_IFIFO;
 161                 break;
 162         default:
 163                 dbg("unknown node type %c\n", dev->type);
 164                 return -EINVAL;
 165         }
 166
 167         /* create parent directories if needed */
 168         if (strrchr(dev->name, '/'))
 169                 create_path(filename);
 170
 171         if (dev->owner[0] != '\0') {
 172                 char *endptr;
 173                 unsigned long id = strtoul(dev->owner, &endptr, 10);
 174                 if (endptr[0] == '\0')
 175                         uid = (uid_t) id;
 176                 else {
 177                         struct passwd *pw = getpwnam(dev->owner);
 178                         if (pw == NULL)
 179                                 dbg("specified user unknown '%s'", dev->owner);
 180                         else
 181                                 uid = pw->pw_uid;
 182                 }
 183         }
 184
 185         if (dev->group[0] != '\0') {
 186                 char *endptr;
 187                 unsigned long id = strtoul(dev->group, &endptr, 10);
 188                 if (endptr[0] == '\0')
 189                         gid = (gid_t) id;
 190                 else {
 191                         struct group *gr = getgrnam(dev->group);
 192                         if (gr == NULL)
 193                                 dbg("specified group unknown '%s'", dev->group);
 194                         else
 195                                 gid = gr->gr_gid;
 196                 }
 197         }
 198
 199         if (!fake) {
 200                 info("creating device node '%s'", filename);
 201                 make_node(filename, dev->major, dev->minor, dev->mode, uid, gid);
 202         } else {
 203                 info("creating device node '%s', major = '%d', minor = '%d', "
 204                      "mode = '%#o', uid = '%d', gid = '%d'", filename,
 205                      dev->major, dev->minor, (mode_t)dev->mode, uid, gid);
 206         }
 207
 208         /* create partitions if requested */
 209         if (dev->partitions > 0) {
 210                 info("creating device partition nodes '%s[1-%i]'", filename, dev->partitions);
 211                 if (!fake) {
 212                         for (i = 1; i <= dev->partitions; i++) {
 213                                 sprintf(partitionname, "%s%i", filename, i);
 214                                 make_node(partitionname, dev->major,
 215                                           dev->minor + i, dev->mode, uid, gid);
 216                         }
 217                 }
 218         }
 219
 220         /* create symlink if requested */
 221         if (dev->symlink[0] != '\0') {
 222                 symlinks = dev->symlink;
 223                 while (1) {
 224                         linkname = strsep(&symlinks, " ");
 225                         if (linkname == NULL || linkname[0] == '\0')
 226                                 break;
 227
 228                         strncpy(filename, udev_root, sizeof(filename));
 229                         strncat(filename, linkname, sizeof(filename));
 230                         dbg("symlink '%s' to node '%s' requested", filename, dev->name);
 231                         if (!fake)
 232                                 if (strrchr(linkname, '/'))
 233                                         create_path(filename);
 234
 235                         /* optimize relative link */
 236                         linktarget[0] = '\0';
 237                         i = 0;
 238                         tail = 0;
 239                         while ((dev->name[i] == linkname[i]) && dev->name[i]) {
 240                                 if (dev->name[i] == '/')
 241                                         tail = i+1;
 242                                 i++;
 243                         }
 244                         while (linkname[i] != '\0') {
 245                                 if (linkname[i] == '/')
 246                                         strcat(linktarget, "../");
 247                                 i++;
 248                         }
 249
 250                         if (linktarget[0] == '\0')
 251                                 strcpy(linktarget, "./");
 252                         strcat(linktarget, &dev->name[tail]);
 253
 254                         /* unlink existing files to ensure that our symlink is created */
 255                         if (!fake && (lstat(filename, &stats) == 0)) {
 256                                 if ((stats.st_mode & S_IFMT) != S_IFDIR) {
 257                                         if (unlink(filename))
 258                                                 dbg("unlink(%s) failed with error '%s'",
 259                                                     filename, strerror(errno));
 260                                 }
 261                         }
 262
 263                         dbg("symlink(%s, %s)", linktarget, filename);
 264                         if (!fake) {
 265                                 retval = symlink(linktarget, filename);
 266                                 if (retval != 0)
 267                                         dbg("symlink(%s, %s) failed with error '%s'",
 268                                             linktarget, filename, strerror(errno));
 269                         }
 270                 }
 271         }
 272
 273         return retval;
 274 }
 275
 276 static struct sysfs_class_device *get_class_dev(char *device_name)
 277 {
 278         char dev_path[SYSFS_PATH_MAX];
 279         struct sysfs_class_device *class_dev = NULL;
 280
 281         strcpy(dev_path, sysfs_path);
 282         strcat(dev_path, device_name);
 283         dbg("looking at '%s'", dev_path);
 284
 285         /* open up the sysfs class device for this thing... */
 286         class_dev = sysfs_open_class_device_path(dev_path);
 287         if (class_dev == NULL) {
 288                 dbg ("sysfs_open_class_device_path failed");
 289                 goto exit;
 290         }
 291         dbg("class_dev->name='%s'", class_dev->name);
 292
 293 exit:
 294         return class_dev;
 295 }
 296
 297 /* wait for the "dev" file to show up in the directory in sysfs.
 298  * If it doesn't happen in about 10 seconds, give up.
 299  */
 300 #define SECONDS_TO_WAIT_FOR_DEV         10
 301 static int sleep_for_dev(char *path)
 302 {
 303         char filename[SYSFS_PATH_MAX + 6];
 304         int loop = SECONDS_TO_WAIT_FOR_DEV;
 305         int retval;
 306
 307         strcpy(filename, sysfs_path);
 308         strcat(filename, path);
 309         strcat(filename, "/dev");
 310
 311         while (loop--) {
 312                 struct stat buf;
 313
 314                 dbg("looking for '%s'", filename);
 315                 retval = stat(filename, &buf);
 316                 if (retval == 0)
 317                         goto exit;
 318
 319                 /* sleep to give the kernel a chance to create the dev file */
 320                 sleep(1);
 321         }
 322         retval = -ENODEV;
 323 exit:
 324         return retval;
 325 }
 326
 327 int udev_add_device(char *path, char *subsystem, int fake)
 328 {
 329         struct sysfs_class_device *class_dev = NULL;
 330         struct udevice dev;
 331         int retval = -EINVAL;
 332
 333         memset(&dev, 0x00, sizeof(dev));
 334
 335         /* for now, the block layer is the only place where block devices are */
 336         if (strcmp(subsystem, "block") == 0)
 337                 dev.type = 'b';
 338         else
 339                 dev.type = 'c';
 340
 341         retval = sleep_for_dev(path);
 342         if (retval != 0)
 343                 goto exit;
 344
 345         class_dev = get_class_dev(path);
 346         if (class_dev == NULL)
 347                 goto exit;
 348
 349         retval = get_major_minor(class_dev, &dev);
 350         if (retval != 0) {
 351                 dbg("get_major_minor failed");
 352                 goto exit;
 353         }
 354
 355         retval = namedev_name_device(class_dev, &dev);
 356         if (retval != 0)
 357                 goto exit;
 358
 359         if (!fake) {
 360                 retval = udevdb_add_dev(path, &dev);
 361                 if (retval != 0)
 362                         dbg("udevdb_add_dev failed, but we are going to try "
 363                             "to create the node anyway. But remove might not "
 364                             "work properly for this device.");
 365
 366         }
 367         dbg("name='%s'", dev.name);
 368         retval = create_node(&dev, fake);
 369
 370         if ((retval == 0) && (!fake))
 371                 sysbus_send_create(&dev, path);
 372
 373 exit:
 374         if (class_dev)
 375                 sysfs_close_class_device(class_dev);
 376
 377         return retval;
 378 }