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 #include <net/if.h>
  34 #include <sys/socket.h>
  35 #include <sys/ioctl.h>
  36 #include <linux/sockios.h>
  37 #ifndef __KLIBC__
  38 #include <pwd.h>
  39 #include <utmp.h>
  40 #endif
  41
  42 #include "libsysfs/sysfs/libsysfs.h"
  43 #include "udev.h"
  44 #include "udev_lib.h"
  45 #include "udev_version.h"
  46 #include "logging.h"
  47 #include "namedev.h"
  48 #include "udevdb.h"
  49 #include "klibc_fixups.h"
  50
  51 #define LOCAL_USER "$local"
  52
  53 /*
  54  * Right now the major/minor of a device is stored in a file called
  55  * "dev" in sysfs.
  56  * The number is stored as:
  57  *      MM:mm
  58  *              MM is the major
  59  *              mm is the minor
  60  *              The value is in decimal.
  61  */
  62 static int get_major_minor(struct sysfs_class_device *class_dev, struct udevice *udev)
  63 {
  64         struct sysfs_attribute *attr = NULL;
  65
  66         attr = sysfs_get_classdev_attr(class_dev, "dev");
  67         if (attr == NULL)
  68                 goto error;
  69         dbg("dev='%s'", attr->value);
  70
  71         if (sscanf(attr->value, "%u:%u", &udev->major, &udev->minor) != 2)
  72                 goto error;
  73         dbg("found major=%d, minor=%d", udev->major, udev->minor);
  74
  75         return 0;
  76 error:
  77         return -1;
  78 }
  79
  80 static int create_path(char *file)
  81 {
  82         char p[NAME_SIZE];
  83         char *pos;
  84         int retval;
  85         struct stat stats;
  86
  87         strfieldcpy(p, file);
  88         pos = strchr(p+1, '/');
  89         while (1) {
  90                 pos = strchr(pos+1, '/');
  91                 if (pos == NULL)
  92                         break;
  93                 *pos = 0x00;
  94                 if (stat(p, &stats)) {
  95                         retval = mkdir(p, 0755);
  96                         if (retval != 0) {
  97                                 dbg("mkdir(%s) failed with error '%s'",
  98                                     p, strerror(errno));
  99                                 return retval;
 100                         }
 101                         dbg("created '%s'", p);
 102                 }
 103                 *pos = '/';
 104         }
 105         return 0;
 106 }
 107
 108 static int make_node(char *file, int major, int minor, unsigned int mode, uid_t uid, gid_t gid)
 109 {
 110         struct stat stats;
 111         int retval = 0;
 112
 113         if (stat(file, &stats) != 0)
 114                 goto create;
 115
 116         /* preserve node with already correct numbers, to not change the inode number */
 117         if (((stats.st_mode & S_IFMT) == S_IFBLK || (stats.st_mode & S_IFMT) == S_IFCHR) &&
 118             (stats.st_rdev == makedev(major, minor))) {
 119                 dbg("preserve file '%s', cause it has correct dev_t", file);
 120                 goto perms;
 121         }
 122
 123         if (unlink(file) != 0)
 124                 dbg("unlink(%s) failed with error '%s'", file, strerror(errno));
 125         else
 126                 dbg("already present file '%s' unlinked", file);
 127
 128 create:
 129         retval = mknod(file, mode, makedev(major, minor));
 130         if (retval != 0) {
 131                 dbg("mknod(%s, %#o, %u, %u) failed with error '%s'",
 132                     file, mode, major, minor, strerror(errno));
 133                 goto exit;
 134         }
 135
 136 perms:
 137         dbg("chmod(%s, %#o)", file, mode);
 138         if (chmod(file, mode) != 0) {
 139                 dbg("chmod(%s, %#o) failed with error '%s'", file, mode, strerror(errno));
 140                 goto exit;
 141         }
 142
 143         if (uid != 0 || gid != 0) {
 144                 dbg("chown(%s, %u, %u)", file, uid, gid);
 145                 if (chown(file, uid, gid) != 0) {
 146                         dbg("chown(%s, %u, %u) failed with error '%s'",
 147                             file, uid, gid, strerror(errno));
 148                         goto exit;
 149                 }
 150         }
 151
 152 exit:
 153         return retval;
 154 }
 155
 156 /* get the local logged in user */
 157 static void set_to_local_user(char *user)
 158 {
 159         struct utmp *u;
 160         time_t recent = 0;
 161
 162         strfieldcpymax(user, default_owner_str, OWNER_SIZE);
 163         setutent();
 164         while (1) {
 165                 u = getutent();
 166                 if (u == NULL)
 167                         break;
 168
 169                 /* is this a user login ? */
 170                 if (u->ut_type != USER_PROCESS)
 171                         continue;
 172
 173                 /* is this a local login ? */
 174                 if (strcmp(u->ut_host, ""))
 175                         continue;
 176
 177                 if (u->ut_time > recent) {
 178                         recent = u->ut_time;
 179                         strfieldcpymax(user, u->ut_user, OWNER_SIZE);
 180                         dbg("local user is '%s'", user);
 181                         break;
 182                 }
 183         }
 184         endutent();
 185 }
 186
 187 static int create_node(struct udevice *dev, int fake)
 188 {
 189         char filename[NAME_SIZE];
 190         char linkname[NAME_SIZE];
 191         char linktarget[NAME_SIZE];
 192         char partitionname[NAME_SIZE];
 193         uid_t uid = 0;
 194         gid_t gid = 0;
 195         int i;
 196         int tail;
 197         char *pos;
 198         int len;
 199
 200         strfieldcpy(filename, udev_root);
 201         strfieldcat(filename, dev->name);
 202
 203         switch (dev->type) {
 204         case 'b':
 205                 dev->mode |= S_IFBLK;
 206                 break;
 207         case 'c':
 208         case 'u':
 209                 dev->mode |= S_IFCHR;
 210                 break;
 211         case 'p':
 212                 dev->mode |= S_IFIFO;
 213                 break;
 214         default:
 215                 dbg("unknown node type %c\n", dev->type);
 216                 return -EINVAL;
 217         }
 218
 219         /* create parent directories if needed */
 220         if (strrchr(dev->name, '/'))
 221                 create_path(filename);
 222
 223         if (dev->owner[0] != '\0') {
 224                 char *endptr;
 225                 unsigned long id = strtoul(dev->owner, &endptr, 10);
 226                 if (endptr[0] == '\0')
 227                         uid = (uid_t) id;
 228                 else {
 229                         struct passwd *pw;
 230                         if (strncmp(dev->owner, LOCAL_USER, sizeof(LOCAL_USER)) == 0)
 231                                 set_to_local_user(dev->owner);
 232
 233                         pw = getpwnam(dev->owner);
 234                         if (pw == NULL)
 235                                 dbg("specified user unknown '%s'", dev->owner);
 236                         else
 237                                 uid = pw->pw_uid;
 238                 }
 239         }
 240
 241         if (dev->group[0] != '\0') {
 242                 char *endptr;
 243                 unsigned long id = strtoul(dev->group, &endptr, 10);
 244                 if (endptr[0] == '\0')
 245                         gid = (gid_t) id;
 246                 else {
 247                         struct group *gr = getgrnam(dev->group);
 248                         if (gr == NULL)
 249                                 dbg("specified group unknown '%s'", dev->group);
 250                         else
 251                                 gid = gr->gr_gid;
 252                 }
 253         }
 254
 255         if (!fake) {
 256                 info("creating device node '%s'", filename);
 257                 if (make_node(filename, dev->major, dev->minor, dev->mode, uid, gid) != 0)
 258                         goto error;
 259         } else {
 260                 info("creating device node '%s', major = '%d', minor = '%d', "
 261                      "mode = '%#o', uid = '%d', gid = '%d'", filename,
 262                      dev->major, dev->minor, (mode_t)dev->mode, uid, gid);
 263         }
 264
 265         /* create all_partitions if requested */
 266         if (dev->partitions > 0) {
 267                 info("creating device partition nodes '%s[1-%i]'", filename, dev->partitions);
 268                 if (!fake) {
 269                         for (i = 1; i <= dev->partitions; i++) {
 270                                 strfieldcpy(partitionname, filename);
 271                                 strintcat(partitionname, i);
 272                                 make_node(partitionname, dev->major,
 273                                           dev->minor + i, dev->mode, uid, gid);
 274                         }
 275                 }
 276         }
 277
 278         /* create symlink(s) if requested */
 279         foreach_strpart(dev->symlink, " ", pos, len) {
 280                 strfieldcpymax(linkname, pos, len+1);
 281                 strfieldcpy(filename, udev_root);
 282                 strfieldcat(filename, linkname);
 283                 dbg("symlink '%s' to node '%s' requested", filename, dev->name);
 284                 if (!fake)
 285                         if (strrchr(linkname, '/'))
 286                                 create_path(filename);
 287
 288                 /* optimize relative link */
 289                 linktarget[0] = '\0';
 290                 i = 0;
 291                 tail = 0;
 292                 while ((dev->name[i] == linkname[i]) && dev->name[i]) {
 293                         if (dev->name[i] == '/')
 294                                 tail = i+1;
 295                         i++;
 296                 }
 297                 while (linkname[i] != '\0') {
 298                         if (linkname[i] == '/')
 299                                 strfieldcat(linktarget, "../");
 300                         i++;
 301                 }
 302
 303                 strfieldcat(linktarget, &dev->name[tail]);
 304
 305                 dbg("symlink(%s, %s)", linktarget, filename);
 306                 if (!fake) {
 307                         unlink(filename);
 308                         if (symlink(linktarget, filename) != 0)
 309                                 dbg("symlink(%s, %s) failed with error '%s'",
 310                                     linktarget, filename, strerror(errno));
 311                 }
 312         }
 313
 314         return 0;
 315 error:
 316         return -1;
 317 }
 318
 319 static struct sysfs_class_device *get_class_dev(char *device_name)
 320 {
 321         char dev_path[SYSFS_PATH_MAX];
 322         struct sysfs_class_device *class_dev = NULL;
 323
 324         strfieldcpy(dev_path, sysfs_path);
 325         strfieldcat(dev_path, device_name);
 326         dbg("looking at '%s'", dev_path);
 327
 328         /* open up the sysfs class device for this thing... */
 329         class_dev = sysfs_open_class_device_path(dev_path);
 330         if (class_dev == NULL) {
 331                 dbg ("sysfs_open_class_device_path failed");
 332                 goto exit;
 333         }
 334         dbg("class_dev->name='%s'", class_dev->name);
 335
 336 exit:
 337         return class_dev;
 338 }
 339
 340 /* wait for the "dev" file to show up in the directory in sysfs.
 341  * If it doesn't happen in about 10 seconds, give up.
 342  */
 343 #define SECONDS_TO_WAIT_FOR_FILE        10
 344 static int sleep_for_file(char *path, char* file)
 345 {
 346         char filename[SYSFS_PATH_MAX + 6];
 347         int loop = SECONDS_TO_WAIT_FOR_FILE;
 348         int retval;
 349
 350         strfieldcpy(filename, sysfs_path);
 351         strfieldcat(filename, path);
 352         strfieldcat(filename, file);
 353
 354         while (loop--) {
 355                 struct stat buf;
 356
 357                 dbg("looking for '%s'", filename);
 358                 retval = stat(filename, &buf);
 359                 if (retval == 0)
 360                         goto exit;
 361
 362                 /* sleep to give the kernel a chance to create the dev file */
 363                 sleep(1);
 364         }
 365         retval = -ENODEV;
 366 exit:
 367         return retval;
 368 }
 369
 370 static int rename_net_if(struct udevice *dev, int fake)
 371 {
 372         int sk;
 373         struct ifreq ifr;
 374         int retval;
 375
 376         dbg("changing net interface name from '%s' to '%s'", dev->kernel_name, dev->name);
 377         if (fake)
 378                 return 0;
 379
 380         sk = socket(PF_INET, SOCK_DGRAM, 0);
 381         if (sk < 0) {
 382                 dbg("error opening socket");
 383                 return -1;
 384         }
 385
 386         memset(&ifr, 0x00, sizeof(struct ifreq));
 387         strfieldcpy(ifr.ifr_name, dev->kernel_name);
 388         strfieldcpy(ifr.ifr_newname, dev->name);
 389
 390         retval = ioctl(sk, SIOCSIFNAME, &ifr);
 391         if (retval != 0)
 392                 dbg("error changing net interface name");
 393         close(sk);
 394
 395         return retval;
 396 }
 397
 398 int udev_add_device(char *path, char *subsystem, int fake)
 399 {
 400         struct sysfs_class_device *class_dev;
 401         struct udevice dev;
 402         char devpath[DEVPATH_SIZE];
 403         char *pos;
 404         int retval;
 405
 406         memset(&dev, 0x00, sizeof(dev));
 407
 408         dev.type = get_device_type(path, subsystem);
 409         switch (dev.type) {
 410         case 'b':
 411         case 'c':
 412                 retval = sleep_for_file(path, "/dev");
 413                 break;
 414
 415         case 'n':
 416                 retval = sleep_for_file(path, "/address");
 417                 break;
 418
 419         default:
 420                 dbg("unknown device type '%c'", dev.type);
 421                 return -1;
 422         }
 423
 424         class_dev = get_class_dev(path);
 425         if (class_dev == NULL)
 426                 return -1;
 427
 428         if (dev.type == 'b' || dev.type == 'c') {
 429                 retval = get_major_minor(class_dev, &dev);
 430                 if (retval != 0) {
 431                         dbg("get_major_minor failed");
 432                         goto exit;
 433                 }
 434         }
 435
 436         if (namedev_name_device(class_dev, &dev) != 0)
 437                 goto exit;
 438
 439         dbg("name='%s'", dev.name);
 440
 441         switch (dev.type) {
 442         case 'b':
 443         case 'c':
 444                 retval = create_node(&dev, fake);
 445                 if (retval != 0)
 446                         goto exit;
 447                 if ((!fake) && (udevdb_add_dev(path, &dev) != 0))
 448                         dbg("udevdb_add_dev failed, but we are going to try "
 449                             "to create the node anyway. But remove might not "
 450                             "work properly for this device.");
 451
 452                 dev_d_send(&dev, subsystem, path);
 453                 break;
 454
 455         case 'n':
 456                 strfieldcpy(devpath, path);
 457                 if (strcmp(dev.name, dev.kernel_name) != 0) {
 458                         retval = rename_net_if(&dev, fake);
 459                         if (retval != 0)
 460                                 goto exit;
 461                         /* netif's are keyed with the configured name, cause
 462                          * the original kernel name sleeps with the fishes
 463                          */
 464                         pos = strrchr(devpath, '/');
 465                         if (pos != NULL) {
 466                                 pos[1] = '\0';
 467                                 strfieldcat(devpath, dev.name);
 468                         }
 469                 }
 470                 if ((!fake) && (udevdb_add_dev(devpath, &dev) != 0))
 471                         dbg("udevdb_add_dev failed");
 472
 473                 dev_d_send(&dev, subsystem, devpath);
 474                 break;
 475         }
 476
 477 exit:
 478         sysfs_close_class_device(class_dev);
 479
 480         return retval;
 481 }