udev_utils.c

   1 /*
   2  * udev_lib - generic stuff used by udev
   3  *
   4  * Copyright (C) 2004 Kay Sievers <kay@vrfy.org>
   5  *
   6  *      This program is free software; you can redistribute it and/or modify it
   7  *      under the terms of the GNU General Public License as published by the
   8  *      Free Software Foundation version 2 of the License.
   9  *
  10  *      This program is distributed in the hope that it will be useful, but
  11  *      WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  *      General Public License for more details.
  14  *
  15  *      You should have received a copy of the GNU General Public License along
  16  *      with this program; if not, write to the Free Software Foundation, Inc.,
  17  *      675 Mass Ave, Cambridge, MA 02139, USA.
  18  *
  19  */
  20
  21
  22 #include <stdlib.h>
  23 #include <stdio.h>
  24 #include <stddef.h>
  25 #include <unistd.h>
  26 #include <fcntl.h>
  27 #include <errno.h>
  28 #include <ctype.h>
  29 #include <dirent.h>
  30 #include <syslog.h>
  31 #include <sys/wait.h>
  32 #include <sys/stat.h>
  33 #include <sys/mman.h>
  34 #include <sys/utsname.h>
  35
  36 #include "udev_libc_wrapper.h"
  37 #include "udev.h"
  38 #include "logging.h"
  39 #include "udev_utils.h"
  40 #include "list.h"
  41
  42
  43 int udev_init_device(struct udevice *udev, const char* devpath, const char *subsystem, const char *action)
  44 {
  45         char *pos;
  46
  47         memset(udev, 0x00, sizeof(struct udevice));
  48         INIT_LIST_HEAD(&udev->symlink_list);
  49         INIT_LIST_HEAD(&udev->run_list);
  50         INIT_LIST_HEAD(&udev->env_list);
  51
  52         if (subsystem)
  53                 strlcpy(udev->subsystem, subsystem, sizeof(udev->subsystem));
  54
  55         if (action)
  56                 strlcpy(udev->action, action, sizeof(udev->action));
  57
  58         if (devpath) {
  59                 strlcpy(udev->devpath, devpath, sizeof(udev->devpath));
  60                 remove_trailing_char(udev->devpath, '/');
  61
  62                 if (strncmp(udev->devpath, "/block/", 7) == 0)
  63                         udev->type = DEV_BLOCK;
  64                 else if (strncmp(udev->devpath, "/class/net/", 11) == 0)
  65                         udev->type = DEV_NET;
  66                 else if (strncmp(udev->devpath, "/class/", 7) == 0)
  67                         udev->type = DEV_CLASS;
  68                 else if (strncmp(udev->devpath, "/devices/", 9) == 0)
  69                         udev->type = DEV_DEVICE;
  70
  71                 /* get kernel name */
  72                 pos = strrchr(udev->devpath, '/');
  73                 if (pos) {
  74                         strlcpy(udev->kernel_name, &pos[1], sizeof(udev->kernel_name));
  75                         dbg("kernel_name='%s'", udev->kernel_name);
  76
  77                         /* Some block devices have '!' in their name, change that to '/' */
  78                         pos = udev->kernel_name;
  79                         while (pos[0] != '\0') {
  80                                 if (pos[0] == '!')
  81                                         pos[0] = '/';
  82                                 pos++;
  83                         }
  84
  85                         /* get kernel number */
  86                         pos = &udev->kernel_name[strlen(udev->kernel_name)];
  87                         while (isdigit(pos[-1]))
  88                                 pos--;
  89                         strlcpy(udev->kernel_number, pos, sizeof(udev->kernel_number));
  90                         dbg("kernel_number='%s'", udev->kernel_number);
  91                 }
  92         }
  93
  94         if (udev->type == DEV_BLOCK || udev->type == DEV_CLASS) {
  95                 udev->mode = 0660;
  96                 strcpy(udev->owner, "root");
  97                 strcpy(udev->group, "root");
  98         }
  99
 100         return 0;
 101 }
 102
 103 void udev_cleanup_device(struct udevice *udev)
 104 {
 105         struct name_entry *name_loop;
 106         struct name_entry *temp_loop;
 107
 108         list_for_each_entry_safe(name_loop, temp_loop, &udev->symlink_list, node) {
 109                 list_del(&name_loop->node);
 110                 free(name_loop);
 111         }
 112         list_for_each_entry_safe(name_loop, temp_loop, &udev->run_list, node) {
 113                 list_del(&name_loop->node);
 114                 free(name_loop);
 115         }
 116         list_for_each_entry_safe(name_loop, temp_loop, &udev->env_list, node) {
 117                 list_del(&name_loop->node);
 118                 free(name_loop);
 119         }
 120 }
 121
 122 int string_is_true(const char *str)
 123 {
 124         if (strcasecmp(str, "true") == 0)
 125                 return 1;
 126         if (strcasecmp(str, "yes") == 0)
 127                 return 1;
 128         if (strcasecmp(str, "1") == 0)
 129                 return 1;
 130         return 0;
 131 }
 132
 133 int log_priority(const char *priority)
 134 {
 135         char *endptr;
 136         int prio;
 137
 138         prio = strtol(priority, &endptr, 10);
 139         if (endptr[0] == '\0')
 140                 return prio;
 141         if (strncasecmp(priority, "err", 3) == 0)
 142                 return LOG_ERR;
 143         if (strcasecmp(priority, "info") == 0)
 144                 return LOG_INFO;
 145         if (strcasecmp(priority, "debug") == 0)
 146                 return LOG_DEBUG;
 147         if (string_is_true(priority))
 148                 return LOG_ERR;
 149
 150         return 0;
 151 }
 152
 153 int kernel_release_satisfactory(unsigned int version, unsigned int patchlevel, unsigned int sublevel)
 154 {
 155         static unsigned int kversion = 0;
 156         static unsigned int kpatchlevel;
 157         static unsigned int ksublevel;
 158
 159         if (kversion == 0) {
 160                 struct utsname uts;
 161                 if (uname(&uts) != 0)
 162                         return -1;
 163
 164                 if (sscanf (uts.release, "%u.%u.%u", &kversion, &kpatchlevel, &ksublevel) != 3) {
 165                         kversion = 0;
 166                         return -1;
 167                 }
 168         }
 169
 170         if (kversion >= version && kpatchlevel >= patchlevel && ksublevel >= sublevel)
 171                 return 1;
 172         else
 173                 return 0;
 174 }
 175
 176 int create_path(const char *path)
 177 {
 178         char p[PATH_SIZE];
 179         char *pos;
 180         struct stat stats;
 181
 182         strcpy (p, path);
 183         pos = strrchr(p, '/');
 184         if (pos == p || pos == NULL)
 185                 return 0;
 186
 187         while (pos[-1] == '/')
 188                 pos--;
 189
 190         pos[0] = '\0';
 191
 192         dbg("stat '%s'\n", p);
 193         if (stat (p, &stats) == 0 && (stats.st_mode & S_IFMT) == S_IFDIR)
 194                 return 0;
 195
 196         if (create_path (p) != 0)
 197                 return -1;
 198
 199         dbg("mkdir '%s'\n", p);
 200         return mkdir(p, 0755);
 201 }
 202
 203 /* Reset permissions on the device node, before unlinking it to make sure,
 204  * that permisions of possible hard links will be removed too.
 205  */
 206 int unlink_secure(const char *filename)
 207 {
 208         int retval;
 209
 210         retval = chown(filename, 0, 0);
 211         if (retval)
 212                 dbg("chown(%s, 0, 0) failed with error '%s'", filename, strerror(errno));
 213
 214         retval = chmod(filename, 0000);
 215         if (retval)
 216                 dbg("chmod(%s, 0000) failed with error '%s'", filename, strerror(errno));
 217
 218         retval = unlink(filename);
 219         if (errno == ENOENT)
 220                 retval = 0;
 221
 222         if (retval)
 223                 dbg("unlink(%s) failed with error '%s'", filename, strerror(errno));
 224
 225         return retval;
 226 }
 227
 228 int file_map(const char *filename, char **buf, size_t *bufsize)
 229 {
 230         struct stat stats;
 231         int fd;
 232
 233         fd = open(filename, O_RDONLY);
 234         if (fd < 0) {
 235                 return -1;
 236         }
 237
 238         if (fstat(fd, &stats) < 0) {
 239                 close(fd);
 240                 return -1;
 241         }
 242
 243         *buf = mmap(NULL, stats.st_size, PROT_READ, MAP_SHARED, fd, 0);
 244         if (*buf == MAP_FAILED) {
 245                 close(fd);
 246                 return -1;
 247         }
 248         *bufsize = stats.st_size;
 249
 250         close(fd);
 251
 252         return 0;
 253 }
 254
 255 void file_unmap(void *buf, size_t bufsize)
 256 {
 257         munmap(buf, bufsize);
 258 }
 259
 260 /* return number of chars until the next newline, skip escaped newline */
 261 size_t buf_get_line(const char *buf, size_t buflen, size_t cur)
 262 {
 263         int escape = 0;
 264         size_t count;
 265
 266         for (count = cur; count < buflen; count++) {
 267                 if (!escape && buf[count] == '\n')
 268                         break;
 269
 270                 if (buf[count] == '\\')
 271                         escape = 1;
 272                 else
 273                         escape = 0;
 274         }
 275
 276         return count - cur;
 277 }
 278
 279 void replace_untrusted_chars(char *string)
 280 {
 281         size_t len;
 282
 283         for (len = 0; string[len] != '\0'; len++) {
 284                 if (strchr(";,~\\()\'", string[len])) {
 285                         info("replace '%c' in '%s'", string[len], string);
 286                         string[len] = '_';
 287                 }
 288         }
 289 }
 290
 291 void remove_trailing_char(char *path, char c)
 292 {
 293         size_t len;
 294
 295         len = strlen(path);
 296         while (len > 0 && path[len-1] == c)
 297                 path[--len] = '\0';
 298 }
 299
 300 int name_list_add(struct list_head *name_list, const char *name, int sort)
 301 {
 302         struct name_entry *loop_name;
 303         struct name_entry *new_name;
 304
 305         list_for_each_entry(loop_name, name_list, node) {
 306                 /* avoid doubles */
 307                 if (strcmp(loop_name->name, name) == 0) {
 308                         dbg("'%s' is already in the list", name);
 309                         return 0;
 310                 }
 311         }
 312
 313         if (sort)
 314                 list_for_each_entry(loop_name, name_list, node) {
 315                         if (sort && strcmp(loop_name->name, name) > 0)
 316                                 break;
 317                 }
 318
 319         new_name = malloc(sizeof(struct name_entry));
 320         if (new_name == NULL) {
 321                 dbg("error malloc");
 322                 return -ENOMEM;
 323         }
 324
 325         strlcpy(new_name->name, name, sizeof(new_name->name));
 326         dbg("adding '%s'", new_name->name);
 327         list_add_tail(&new_name->node, &loop_name->node);
 328
 329         return 0;
 330 }
 331
 332 int name_list_key_add(struct list_head *name_list, const char *key, const char *value)
 333 {
 334         struct name_entry *loop_name;
 335         struct name_entry *new_name;
 336
 337         list_for_each_entry(loop_name, name_list, node) {
 338                 if (strncmp(loop_name->name, key, strlen(key)) == 0) {
 339                         dbg("key already present '%s', replace it", loop_name->name);
 340                         snprintf(loop_name->name, sizeof(loop_name->name), "%s=%s", key, value);
 341                         loop_name->name[sizeof(loop_name->name)-1] = '\0';
 342                         return 0;
 343                 }
 344         }
 345
 346         new_name = malloc(sizeof(struct name_entry));
 347         if (new_name == NULL) {
 348                 dbg("error malloc");
 349                 return -ENOMEM;
 350         }
 351
 352         snprintf(new_name->name, sizeof(new_name->name), "%s=%s", key, value);
 353         new_name->name[sizeof(new_name->name)-1] = '\0';
 354         dbg("adding '%s'", new_name->name);
 355         list_add_tail(&new_name->node, &loop_name->node);
 356
 357         return 0;
 358 }
 359
 360 /* calls function for every file found in specified directory */
 361 int add_matching_files(struct list_head *name_list, const char *dirname, const char *suffix)
 362 {
 363         struct dirent *ent;
 364         DIR *dir;
 365         char *ext;
 366         char filename[PATH_SIZE];
 367
 368         dbg("open directory '%s'", dirname);
 369         dir = opendir(dirname);
 370         if (dir == NULL) {
 371                 dbg("unable to open '%s'", dirname);
 372                 return -1;
 373         }
 374
 375         while (1) {
 376                 ent = readdir(dir);
 377                 if (ent == NULL || ent->d_name[0] == '\0')
 378                         break;
 379
 380                 if ((ent->d_name[0] == '.') || (ent->d_name[0] == COMMENT_CHARACTER))
 381                         continue;
 382
 383                 /* look for file matching with specified suffix */
 384                 ext = strrchr(ent->d_name, '.');
 385                 if (ext == NULL)
 386                         continue;
 387
 388                 if (strcmp(ext, suffix) != 0)
 389                         continue;
 390
 391                 dbg("put file '%s/%s' in list", dirname, ent->d_name);
 392
 393                 snprintf(filename, sizeof(filename), "%s/%s", dirname, ent->d_name);
 394                 filename[sizeof(filename)-1] = '\0';
 395                 name_list_add(name_list, filename, 1);
 396         }
 397
 398         closedir(dir);
 399         return 0;
 400 }
 401
 402 int execute_program(const char *command, const char *subsystem,
 403                     char *result, size_t ressize, size_t *reslen)
 404 {
 405         int retval = 0;
 406         int count;
 407         int status;
 408         int pipefds[2];
 409         pid_t pid;
 410         char *pos;
 411         char arg[PATH_SIZE];
 412         char *argv[(sizeof(arg) / 2) + 1];
 413         int devnull;
 414         int i;
 415         size_t len;
 416
 417         strlcpy(arg, command, sizeof(arg));
 418         i = 0;
 419         if (strchr(arg, ' ')) {
 420                 pos = arg;
 421                 while (pos != NULL) {
 422                         if (pos[0] == '\'') {
 423                                 /* don't separate if in apostrophes */
 424                                 pos++;
 425                                 argv[i] = strsep(&pos, "\'");
 426                                 while (pos && pos[0] == ' ')
 427                                         pos++;
 428                         } else {
 429                                 argv[i] = strsep(&pos, " ");
 430                         }
 431                         dbg("arg[%i] '%s'", i, argv[i]);
 432                         i++;
 433                 }
 434                 argv[i] =  NULL;
 435                 dbg("execute '%s' with parsed arguments", arg);
 436         } else {
 437                 argv[0] = arg;
 438                 argv[1] = (char *) subsystem;
 439                 argv[2] = NULL;
 440                 dbg("execute '%s' with subsystem '%s' argument", arg, argv[1]);
 441         }
 442
 443         if (result) {
 444                 if (pipe(pipefds) != 0) {
 445                         err("pipe failed");
 446                         return -1;
 447                 }
 448         }
 449
 450         pid = fork();
 451         switch(pid) {
 452         case 0:
 453                 /* child dup2 write side of pipe to STDOUT */
 454                 devnull = open("/dev/null", O_RDWR);
 455                 if (devnull >= 0) {
 456                         dup2(devnull, STDIN_FILENO);
 457                         if (!result)
 458                                 dup2(devnull, STDOUT_FILENO);
 459                         dup2(devnull, STDERR_FILENO);
 460                         close(devnull);
 461                 }
 462                 if (result)
 463                         dup2(pipefds[1], STDOUT_FILENO);
 464                 execv(arg, argv);
 465                 err("exec of program failed");
 466                 _exit(1);
 467         case -1:
 468                 err("fork of '%s' failed", arg);
 469                 return -1;
 470         default:
 471                 /* parent reads from pipefds[0] */
 472                 if (result) {
 473                         close(pipefds[1]);
 474                         len = 0;
 475                         while (1) {
 476                                 count = read(pipefds[0], result + len, ressize - len-1);
 477                                 if (count < 0) {
 478                                         err("read failed with '%s'", strerror(errno));
 479                                         retval = -1;
 480                                         break;
 481                                 }
 482
 483                                 if (count == 0)
 484                                         break;
 485
 486                                 len += count;
 487                                 if (len >= ressize-1) {
 488                                         err("ressize %ld too short", (long)ressize);
 489                                         retval = -1;
 490                                         break;
 491                                 }
 492                         }
 493                         result[len] = '\0';
 494                         close(pipefds[0]);
 495                         if (reslen)
 496                                 *reslen = len;
 497                 }
 498                 waitpid(pid, &status, 0);
 499
 500                 if (!WIFEXITED(status) || (WEXITSTATUS(status) != 0)) {
 501                         dbg("exec program status 0x%x", status);
 502                         retval = -1;
 503                 }
 504         }
 505
 506         return retval;
 507 }