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