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 *filename, int major, int minor, unsigned int mode, uid_t uid, gid_t gid)
 109 {
 110         int retval;
 111
 112         retval = mknod(filename, mode, makedev(major, minor));
 113         if (retval != 0) {
 114                 dbg("mknod(%s, %#o, %u, %u) failed with error '%s'",
 115                     filename, mode, major, minor, strerror(errno));
 116                 goto exit;
 117         }
 118
 119         dbg("chmod(%s, %#o)", filename, mode);
 120         if (chmod(filename, mode) != 0) {
 121                 dbg("chmod(%s, %#o) failed with error '%s'",
 122                     filename, mode, strerror(errno));
 123                 goto exit;
 124         }
 125
 126         if (uid != 0 || gid != 0) {
 127                 dbg("chown(%s, %u, %u)", filename, uid, gid);
 128                 if (chown(filename, uid, gid) != 0) {
 129                         dbg("chown(%s, %u, %u) failed with error '%s'",
 130                             filename, uid, gid, strerror(errno));
 131                         goto exit;
 132                 }
 133         }
 134
 135 exit:
 136         return retval;
 137 }
 138
 139 /* get the local logged in user */
 140 static void set_to_local_user(char *user)
 141 {
 142         struct utmp *u;
 143         time_t recent = 0;
 144
 145         strfieldcpymax(user, default_owner_str, OWNER_SIZE);
 146         setutent();
 147         while (1) {
 148                 u = getutent();
 149                 if (u == NULL)
 150                         break;
 151
 152                 /* is this a user login ? */
 153                 if (u->ut_type != USER_PROCESS)
 154                         continue;
 155
 156                 /* is this a local login ? */
 157                 if (strcmp(u->ut_host, ""))
 158                         continue;
 159
 160                 if (u->ut_time > recent) {
 161                         recent = u->ut_time;
 162                         strfieldcpymax(user, u->ut_user, OWNER_SIZE);
 163                         dbg("local user is '%s'", user);
 164                         break;
 165                 }
 166         }
 167         endutent();
 168 }
 169
 170 static int unlink_entry(char *filename)
 171 {
 172         struct stat stats;
 173         int retval = 0;
 174
 175         if (lstat(filename, &stats) == 0) {
 176                 if ((stats.st_mode & S_IFMT) != S_IFDIR) {
 177                         retval = unlink(filename);
 178                         if (retval) {
 179                                 dbg("unlink(%s) failed with error '%s'",
 180                                     filename, strerror(errno));
 181                         }
 182                 }
 183         }
 184         return retval;
 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                 unlink_entry(filename);
 257                 info("creating device node '%s'", filename);
 258                 if (make_node(filename, dev->major, dev->minor, dev->mode, uid, gid) != 0)
 259                         goto error;
 260         } else {
 261                 info("creating device node '%s', major = '%d', minor = '%d', "
 262                      "mode = '%#o', uid = '%d', gid = '%d'", filename,
 263                      dev->major, dev->minor, (mode_t)dev->mode, uid, gid);
 264         }
 265
 266         /* create all_partitions if requested */
 267         if (dev->partitions > 0) {
 268                 info("creating device partition nodes '%s[1-%i]'", filename, dev->partitions);
 269                 if (!fake) {
 270                         for (i = 1; i <= dev->partitions; i++) {
 271                                 strfieldcpy(partitionname, filename);
 272                                 strintcat(partitionname, i);
 273                                 unlink_entry(partitionname);
 274                                 make_node(partitionname, dev->major,
 275                                           dev->minor + i, dev->mode, uid, gid);
 276                         }
 277                 }
 278         }
 279
 280         /* create symlink(s) if requested */
 281         foreach_strpart(dev->symlink, " ", pos, len) {
 282                 strfieldcpymax(linkname, pos, len+1);
 283                 strfieldcpy(filename, udev_root);
 284                 strfieldcat(filename, linkname);
 285                 dbg("symlink '%s' to node '%s' requested", filename, dev->name);
 286                 if (!fake)
 287                         if (strrchr(linkname, '/'))
 288                                 create_path(filename);
 289
 290                 /* optimize relative link */
 291                 linktarget[0] = '\0';
 292                 i = 0;
 293                 tail = 0;
 294                 while ((dev->name[i] == linkname[i]) && dev->name[i]) {
 295                         if (dev->name[i] == '/')
 296                                 tail = i+1;
 297                         i++;
 298                 }
 299                 while (linkname[i] != '\0') {
 300                         if (linkname[i] == '/')
 301                                 strfieldcat(linktarget, "../");
 302                         i++;
 303                 }
 304
 305                 strfieldcat(linktarget, &dev->name[tail]);
 306
 307                 if (!fake)
 308                         unlink_entry(filename);
 309
 310                 dbg("symlink(%s, %s)", linktarget, filename);
 311                 if (!fake) {
 312                         if (symlink(linktarget, filename) != 0)
 313                                 dbg("symlink(%s, %s) failed with error '%s'",
 314                                     linktarget, filename, strerror(errno));
 315                 }
 316         }
 317
 318         return 0;
 319 error:
 320         return -1;
 321 }
 322
 323 static struct sysfs_class_device *get_class_dev(char *device_name)
 324 {
 325         char dev_path[SYSFS_PATH_MAX];
 326         struct sysfs_class_device *class_dev = NULL;
 327
 328         strfieldcpy(dev_path, sysfs_path);
 329         strfieldcat(dev_path, device_name);
 330         dbg("looking at '%s'", dev_path);
 331
 332         /* open up the sysfs class device for this thing... */
 333         class_dev = sysfs_open_class_device_path(dev_path);
 334         if (class_dev == NULL) {
 335                 dbg ("sysfs_open_class_device_path failed");
 336                 goto exit;
 337         }
 338         dbg("class_dev->name='%s'", class_dev->name);
 339
 340 exit:
 341         return class_dev;
 342 }
 343
 344 /* wait for the "dev" file to show up in the directory in sysfs.
 345  * If it doesn't happen in about 10 seconds, give up.
 346  */
 347 #define SECONDS_TO_WAIT_FOR_FILE        10
 348 static int sleep_for_file(char *path, char* file)
 349 {
 350         char filename[SYSFS_PATH_MAX + 6];
 351         int loop = SECONDS_TO_WAIT_FOR_FILE;
 352         int retval;
 353
 354         strfieldcpy(filename, sysfs_path);
 355         strfieldcat(filename, path);
 356         strfieldcat(filename, file);
 357
 358         while (loop--) {
 359                 struct stat buf;
 360
 361                 dbg("looking for '%s'", filename);
 362                 retval = stat(filename, &buf);
 363                 if (retval == 0)
 364                         goto exit;
 365
 366                 /* sleep to give the kernel a chance to create the dev file */
 367                 sleep(1);
 368         }
 369         retval = -ENODEV;
 370 exit:
 371         return retval;
 372 }
 373
 374 static int rename_net_if(struct udevice *dev, int fake)
 375 {
 376         int sk;
 377         struct ifreq ifr;
 378         int retval;
 379
 380         dbg("changing net interface name from '%s' to '%s'", dev->kernel_name, dev->name);
 381         if (fake)
 382                 return 0;
 383
 384         sk = socket(PF_INET, SOCK_DGRAM, 0);
 385         if (sk < 0) {
 386                 dbg("error opening socket");
 387                 return -1;
 388         }
 389
 390         memset(&ifr, 0x00, sizeof(struct ifreq));
 391         strfieldcpy(ifr.ifr_name, dev->kernel_name);
 392         strfieldcpy(ifr.ifr_newname, dev->name);
 393
 394         retval = ioctl(sk, SIOCSIFNAME, &ifr);
 395         if (retval != 0)
 396                 dbg("error changing net interface name");
 397         close(sk);
 398
 399         return retval;
 400 }
 401
 402 int udev_add_device(char *path, char *subsystem, int fake)
 403 {
 404         struct sysfs_class_device *class_dev;
 405         struct udevice dev;
 406         char devpath[DEVPATH_SIZE];
 407         char *pos;
 408         int retval;
 409
 410         memset(&dev, 0x00, sizeof(dev));
 411
 412         dev.type = get_device_type(path, subsystem);
 413         switch (dev.type) {
 414         case 'b':
 415         case 'c':
 416                 retval = sleep_for_file(path, "/dev");
 417                 break;
 418
 419         case 'n':
 420                 retval = sleep_for_file(path, "/address");
 421                 break;
 422
 423         default:
 424                 dbg("unknown device type '%c'", dev.type);
 425                 return -1;
 426         }
 427
 428         class_dev = get_class_dev(path);
 429         if (class_dev == NULL)
 430                 return -1;
 431
 432         if (dev.type == 'b' || dev.type == 'c') {
 433                 retval = get_major_minor(class_dev, &dev);
 434                 if (retval != 0) {
 435                         dbg("get_major_minor failed");
 436                         goto exit;
 437                 }
 438         }
 439
 440         if (namedev_name_device(class_dev, &dev) != 0)
 441                 goto exit;
 442
 443         dbg("name='%s'", dev.name);
 444
 445         switch (dev.type) {
 446         case 'b':
 447         case 'c':
 448                 retval = create_node(&dev, fake);
 449                 if (retval != 0)
 450                         goto exit;
 451                 if ((!fake) && (udevdb_add_dev(path, &dev) != 0))
 452                         dbg("udevdb_add_dev failed, but we are going to try "
 453                             "to create the node anyway. But remove might not "
 454                             "work properly for this device.");
 455
 456                 dev_d_send(&dev, subsystem, path);
 457                 break;
 458
 459         case 'n':
 460                 if (strcmp(dev.name, dev.kernel_name) != 0) {
 461                         retval = rename_net_if(&dev, fake);
 462                         if (retval != 0)
 463                                 goto exit;
 464                         /* netif's are keyed with the configured name, cause
 465                          * the original kernel name sleeps with the fishes
 466                          */
 467                         strfieldcpy(devpath, path);
 468                         pos = strrchr(devpath, '/');
 469                         if (pos != NULL) {
 470                                 pos[1] = '\0';
 471                                 strfieldcat(devpath, dev.name);
 472                         }
 473                 }
 474                 if ((!fake) && (udevdb_add_dev(devpath, &dev) != 0))
 475                         dbg("udevdb_add_dev failed");
 476
 477                 dev_d_send(&dev, subsystem, devpath);
 478                 break;
 479         }
 480
 481 exit:
 482         sysfs_close_class_device(class_dev);
 483
 484         return retval;
 485 }