udev_rules.c

   1 /*
   2  * udev_rules.c
   3  *
   4  * Copyright (C) 2003 Greg Kroah-Hartman <greg@kroah.com>
   5  * Copyright (C) 2003-2005 Kay Sievers <kay.sievers@vrfy.org>
   6  *
   7  *      This program is free software; you can redistribute it and/or modify it
   8  *      under the terms of the GNU General Public License as published by the
   9  *      Free Software Foundation version 2 of the License.
  10  *
  11  *      This program is distributed in the hope that it will be useful, but
  12  *      WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  *      General Public License for more details.
  15  *
  16  *      You should have received a copy of the GNU General Public License along
  17  *      with this program; if not, write to the Free Software Foundation, Inc.,
  18  *      675 Mass Ave, Cambridge, MA 02139, USA.
  19  *
  20  */
  21
  22 #include <stddef.h>
  23 #include <stdlib.h>
  24 #include <string.h>
  25 #include <stdio.h>
  26 #include <fcntl.h>
  27 #include <ctype.h>
  28 #include <unistd.h>
  29 #include <errno.h>
  30 #include <syslog.h>
  31 #include <sys/wait.h>
  32 #include <sys/stat.h>
  33
  34 #include "libsysfs/sysfs/libsysfs.h"
  35 #include "list.h"
  36 #include "udev_libc_wrapper.h"
  37 #include "udev.h"
  38 #include "udev_utils.h"
  39 #include "udev_version.h"
  40 #include "logging.h"
  41 #include "udev_rules.h"
  42 #include "udev_db.h"
  43
  44
  45 /* extract possible {attr} and move str behind it */
  46 static char *get_format_attribute(char **str)
  47 {
  48         char *pos;
  49         char *attr = NULL;
  50
  51         if (*str[0] == '{') {
  52                 pos = strchr(*str, '}');
  53                 if (pos == NULL) {
  54                         err("missing closing brace for format");
  55                         return NULL;
  56                 }
  57                 pos[0] = '\0';
  58                 attr = *str+1;
  59                 *str = pos+1;
  60                 dbg("attribute='%s', str='%s'", attr, *str);
  61         }
  62         return attr;
  63 }
  64
  65 /* extract possible format length and move str behind it*/
  66 static int get_format_len(char **str)
  67 {
  68         int num;
  69         char *tail;
  70
  71         if (isdigit(*str[0])) {
  72                 num = (int) strtoul(*str, &tail, 10);
  73                 if (num > 0) {
  74                         *str = tail;
  75                         dbg("format length=%i", num);
  76                         return num;
  77                 } else {
  78                         err("format parsing error '%s'", *str);
  79                 }
  80         }
  81         return -1;
  82 }
  83
  84 static int get_key(char **line, char **key, char **value)
  85 {
  86         char *linepos;
  87         char *temp;
  88
  89         linepos = *line;
  90         if (!linepos)
  91                 return -1;
  92
  93         if (strchr(linepos, '\\')) {
  94                 dbg("escaped characters are not supported, skip");
  95                 return -1;
  96         }
  97
  98         /* skip whitespace */
  99         while (isspace(linepos[0]))
 100                 linepos++;
 101
 102         /* get the key */
 103         *key = linepos;
 104         while (1) {
 105                 linepos++;
 106                 if (linepos[0] == '\0')
 107                         return -1;
 108                 if (isspace(linepos[0]))
 109                         break;
 110                 if (linepos[0] == '=')
 111                         break;
 112         }
 113
 114         /* terminate key */
 115         linepos[0] = '\0';
 116         linepos++;
 117
 118         /* skip whitespace */
 119         while (isspace(linepos[0]))
 120                 linepos++;
 121
 122         /* get the value*/
 123         if (linepos[0] == '"') {
 124                 linepos++;
 125                 temp = strchr(linepos, '"');
 126                 if (!temp) {
 127                         dbg("missing closing quote");
 128                         return -1;
 129                 }
 130                 dbg("value is quoted");
 131                 temp[0] = '\0';
 132         } else if (linepos[0] == '\'') {
 133                 linepos++;
 134                 temp = strchr(linepos, '\'');
 135                 if (!temp) {
 136                         dbg("missing closing quote");
 137                         return -1;
 138                 }
 139                 dbg("value is quoted");
 140                 temp[0] = '\0';
 141         } else if (linepos[0] == '\0') {
 142                 dbg("value is empty");
 143         } else {
 144                 temp = linepos;
 145                 while (temp[0] && !isspace(temp[0]))
 146                         temp++;
 147                 temp[0] = '\0';
 148         }
 149         *value = linepos;
 150
 151         return 0;
 152 }
 153
 154 static int import_keys_into_env(struct udevice *udev, const char *buf, size_t bufsize)
 155 {
 156         char line[LINE_SIZE];
 157         const char *bufline;
 158         char *linepos;
 159         char *variable;
 160         char *value;
 161         size_t cur;
 162         size_t count;
 163         int lineno;
 164
 165         /* loop through the whole buffer */
 166         lineno = 0;
 167         cur = 0;
 168         while (cur < bufsize) {
 169                 count = buf_get_line(buf, bufsize, cur);
 170                 bufline = &buf[cur];
 171                 cur += count+1;
 172                 lineno++;
 173
 174                 if (count >= sizeof(line)) {
 175                         err("line too long, conf line skipped %s, line %d", udev_config_filename, lineno);
 176                         continue;
 177                 }
 178
 179                 /* eat the whitespace */
 180                 while ((count > 0) && isspace(bufline[0])) {
 181                         bufline++;
 182                         count--;
 183                 }
 184                 if (count == 0)
 185                         continue;
 186
 187                 /* see if this is a comment */
 188                 if (bufline[0] == COMMENT_CHARACTER)
 189                         continue;
 190
 191                 memcpy(line, bufline, count);
 192                 line[count] = '\0';
 193
 194                 linepos = line;
 195                 if (get_key(&linepos, &variable, &value) == 0) {
 196                         dbg("import '%s=%s'", variable, value);
 197                         name_list_key_add(&udev->env_list, variable, value);
 198                         setenv(variable, value, 1);
 199                 }
 200         }
 201
 202         return 0;
 203 }
 204
 205 static int import_file_into_env(struct udevice *udev, const char *filename)
 206 {
 207         char *buf;
 208         size_t bufsize;
 209
 210         if (file_map(filename, &buf, &bufsize) != 0) {
 211                 err("can't open '%s'", filename);
 212                 return -1;
 213         }
 214         import_keys_into_env(udev, buf, bufsize);
 215         file_unmap(buf, bufsize);
 216
 217         return 0;
 218 }
 219
 220 static int import_program_into_env(struct udevice *udev, const char *program)
 221 {
 222         char result[1024];
 223         size_t reslen;
 224
 225         if (run_program(program, udev->subsystem, result, sizeof(result), &reslen, (udev_log_priority >= LOG_INFO)) != 0)
 226                 return -1;
 227         return import_keys_into_env(udev, result, reslen);
 228 }
 229
 230 static int import_parent_into_env(struct udevice *udev, struct sysfs_class_device *class_dev, const char *filter)
 231 {
 232         struct sysfs_class_device *parent = sysfs_get_classdev_parent(class_dev);
 233         int rc = -1;
 234
 235         if (parent != NULL) {
 236                 struct udevice udev_parent;
 237                 struct name_entry *name_loop;
 238
 239                 dbg("found parent '%s', get the node name", parent->path);
 240                 udev_init_device(&udev_parent, NULL, NULL, NULL);
 241                 /* import the udev_db of the parent */
 242                 if (udev_db_get_device(&udev_parent, &parent->path[strlen(sysfs_path)]) == 0) {
 243                         dbg("import stored parent env '%s'", udev_parent.name);
 244                         list_for_each_entry(name_loop, &udev_parent.env_list, node) {
 245                                 char name[NAME_SIZE];
 246                                 char *pos;
 247
 248                                 strlcpy(name, name_loop->name, sizeof(name));
 249                                 pos = strchr(name, '=');
 250                                 if (pos) {
 251                                         pos[0] = '\0';
 252                                         pos++;
 253                                         if (strcmp_pattern(filter, name) == 0) {
 254                                                 dbg("import key '%s'", name_loop->name);
 255                                                 name_list_add(&udev->env_list, name_loop->name, 0);
 256                                                 setenv(name, pos, 1);
 257                                         } else
 258                                                 dbg("skip key '%s'", name_loop->name);
 259                                 }
 260                         }
 261                         rc = 0;
 262                 } else
 263                         dbg("parent not found in database");
 264                 udev_cleanup_device(&udev_parent);
 265         }
 266
 267         return rc;
 268 }
 269
 270 static int match_name_and_get_number(const char *base, const char *devname)
 271 {
 272         size_t baselen;
 273         char *endptr;
 274         int num;
 275
 276         baselen = strlen(base);
 277         if (strncmp(base, devname, baselen) != 0)
 278                 return -1;
 279         if (devname[baselen] == '\0')
 280                 return 0;
 281         if (!isdigit(devname[baselen]))
 282                 return -1;
 283         num = strtoul(&devname[baselen], &endptr, 10);
 284         if (endptr[0] != '\0')
 285                 return -1;
 286         return num;
 287 }
 288
 289 /* finds the lowest positive device number such that <name>N isn't present in the udevdb
 290  * if <name> doesn't exist, 0 is returned, N otherwise */
 291 static int find_free_number(const char *base, const char *devpath)
 292 {
 293         char db_devpath[PATH_SIZE];
 294         char filename[PATH_SIZE];
 295         struct udevice udev_db;
 296         int num = 0;
 297
 298         /* check if the device already owns a matching name */
 299         udev_init_device(&udev_db, NULL, NULL, NULL);
 300         if (udev_db_get_device(&udev_db, devpath) == 0) {
 301                 struct name_entry *name_loop;
 302                 int devnum;
 303
 304                 devnum = match_name_and_get_number(base, udev_db.name);
 305                 if (devnum >= 0) {
 306                         num = devnum;
 307                         dbg("device '%s', already has the node '%s' with num %u, use it", devpath, base, num);
 308                         goto out;
 309                 }
 310                 list_for_each_entry(name_loop, &udev_db.symlink_list, node) {
 311                         devnum = match_name_and_get_number(base, name_loop->name);
 312                         if (devnum >= 0) {
 313                                 num = devnum;
 314                                 dbg("device '%s', already has a symlink '%s' with num %u, use it", devpath, base, num);
 315                                 goto out;
 316                         }
 317                 }
 318         }
 319
 320         /* just search the database again and again until a free name is found */
 321         strlcpy(filename, base, sizeof(filename));
 322         while (1) {
 323                 dbg("look for existing node '%s'", filename);
 324                 if (udev_db_lookup_name(filename, db_devpath, sizeof(db_devpath)) != 0) {
 325                         dbg("free num=%d", num);
 326                         break;
 327                 }
 328
 329                 num++;
 330                 if (num > 100000) {
 331                         err("find_free_number aborted at num=%d", num);
 332                         num = -1;
 333                         break;
 334                 }
 335                 snprintf(filename, sizeof(filename), "%s%d", base, num);
 336                 filename[sizeof(filename)-1] = '\0';
 337         }
 338
 339 out:
 340         udev_cleanup_device(&udev_db);
 341         return num;
 342 }
 343
 344 static int find_sysfs_attribute(struct sysfs_class_device *class_dev, struct sysfs_device *sysfs_device,
 345                                 const char *name, char *value, size_t len)
 346 {
 347         struct sysfs_class_device *class_dev_parent;
 348         struct sysfs_attribute *tmpattr;
 349
 350         dbg("look for device attribute '%s'", name);
 351         if (class_dev) {
 352                 dbg("look for class attribute '%s/%s'", class_dev->path, name);
 353                 tmpattr = sysfs_get_classdev_attr(class_dev, name);
 354                 if (tmpattr)
 355                         goto attr_found;
 356                 class_dev_parent = sysfs_get_classdev_parent(class_dev);
 357                 if (class_dev_parent) {
 358                         tmpattr = sysfs_get_classdev_attr(class_dev_parent, name);
 359                         if (tmpattr)
 360                                 goto attr_found;
 361                 }
 362         }
 363         if (sysfs_device) {
 364                 dbg("look for devices attribute '%s/%s'", sysfs_device->path, name);
 365                 tmpattr = sysfs_get_device_attr(sysfs_device, name);
 366                 if (tmpattr)
 367                         goto attr_found;
 368         }
 369         return -1;
 370
 371 attr_found:
 372         strlcpy(value, tmpattr->value, len);
 373         remove_trailing_chars(value, '\n');
 374
 375         dbg("found attribute '%s'", tmpattr->path);
 376         return 0;
 377 }
 378
 379 #define WAIT_LOOP_PER_SECOND                    20
 380 static int wait_for_sysfs(struct udevice *udev, const char *file, int timeout)
 381 {
 382         char filename[PATH_SIZE];
 383         struct stat stats;
 384         int loop = timeout * WAIT_LOOP_PER_SECOND;
 385
 386         snprintf(filename, sizeof(filename), "%s%s/%s", sysfs_path, udev->devpath, file);
 387         filename[sizeof(filename)-1] = '\0';
 388         dbg("wait %i sec for '%s'", timeout, filename);
 389
 390         while (--loop) {
 391                 if (stat(filename, &stats) == 0) {
 392                         info("file appeared after %i loops", (timeout * WAIT_LOOP_PER_SECOND) - loop-1);
 393                         return 0;
 394                 }
 395                 usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND);
 396         }
 397         info("waiting for '%s' failed", filename);
 398         return -1;
 399 }
 400
 401 static void apply_format(struct udevice *udev, char *string, size_t maxsize,
 402                          struct sysfs_class_device *class_dev, struct sysfs_device *sysfs_device)
 403 {
 404         char temp[PATH_SIZE];
 405         char temp2[PATH_SIZE];
 406         char *head, *tail, *pos, *cpos, *attr, *rest;
 407         int len;
 408         int i;
 409         int count;
 410         unsigned int next_free_number;
 411         struct sysfs_class_device *class_dev_parent;
 412         enum subst_type {
 413                 SUBST_UNKNOWN,
 414                 SUBST_DEVPATH,
 415                 SUBST_ID,
 416                 SUBST_KERNEL_NUMBER,
 417                 SUBST_KERNEL_NAME,
 418                 SUBST_MAJOR,
 419                 SUBST_MINOR,
 420                 SUBST_RESULT,
 421                 SUBST_SYSFS,
 422                 SUBST_ENUM,
 423                 SUBST_PARENT,
 424                 SUBST_TEMP_NODE,
 425                 SUBST_ROOT,
 426                 SUBST_MODALIAS,
 427                 SUBST_ENV,
 428         };
 429         static const struct subst_map {
 430                 char *name;
 431                 char fmt;
 432                 enum subst_type type;
 433         } map[] = {
 434                 { .name = "devpath",            .fmt = 'p',     .type = SUBST_DEVPATH },
 435                 { .name = "id",                 .fmt = 'b',     .type = SUBST_ID },
 436                 { .name = "number",             .fmt = 'n',     .type = SUBST_KERNEL_NUMBER },
 437                 { .name = "kernel",             .fmt = 'k',     .type = SUBST_KERNEL_NAME },
 438                 { .name = "major",              .fmt = 'M',     .type = SUBST_MAJOR },
 439                 { .name = "minor",              .fmt = 'm',     .type = SUBST_MINOR },
 440                 { .name = "result",             .fmt = 'c',     .type = SUBST_RESULT },
 441                 { .name = "sysfs",              .fmt = 's',     .type = SUBST_SYSFS },
 442                 { .name = "enum",               .fmt = 'e',     .type = SUBST_ENUM },
 443                 { .name = "parent",             .fmt = 'P',     .type = SUBST_PARENT },
 444                 { .name = "tempnode",           .fmt = 'N',     .type = SUBST_TEMP_NODE },
 445                 { .name = "root",               .fmt = 'r',     .type = SUBST_ROOT },
 446                 { .name = "modalias",           .fmt = 'A',     .type = SUBST_MODALIAS },
 447                 { .name = "env",                .fmt = 'E',     .type = SUBST_ENV },
 448                 { NULL, '\0', 0 }
 449         };
 450         enum subst_type type;
 451         const struct subst_map *subst;
 452
 453         head = string;
 454         while (1) {
 455                 len = -1;
 456                 while (head[0] != '\0') {
 457                         if (head[0] == '$') {
 458                                 /* substitute named variable */
 459                                 if (head[1] == '\0')
 460                                         break;
 461                                 if (head[1] == '$') {
 462                                         strlcpy(temp, head+2, sizeof(temp));
 463                                         strlcpy(head+1, temp, maxsize);
 464                                         head++;
 465                                         continue;
 466                                 }
 467                                 head[0] = '\0';
 468                                 for (subst = map; subst->name; subst++) {
 469                                         if (strncasecmp(&head[1], subst->name, strlen(subst->name)) == 0) {
 470                                                 type = subst->type;
 471                                                 tail = head + strlen(subst->name)+1;
 472                                                 dbg("will substitute format name '%s'", subst->name);
 473                                                 goto found;
 474                                         }
 475                                 }
 476                         }
 477                         else if (head[0] == '%') {
 478                                 /* substitute format char */
 479                                 if (head[1] == '\0')
 480                                         break;
 481                                 if (head[1] == '%') {
 482                                         strlcpy(temp, head+2, sizeof(temp));
 483                                         strlcpy(head+1, temp, maxsize);
 484                                         head++;
 485                                         continue;
 486                                 }
 487                                 head[0] = '\0';
 488                                 tail = head+1;
 489                                 len = get_format_len(&tail);
 490                                 for (subst = map; subst->name; subst++) {
 491                                         if (tail[0] == subst->fmt) {
 492                                                 type = subst->type;
 493                                                 tail++;
 494                                                 dbg("will substitute format char '%c'", subst->fmt);
 495                                                 goto found;
 496                                         }
 497                                 }
 498                         }
 499                         head++;
 500                 }
 501                 break;
 502 found:
 503                 attr = get_format_attribute(&tail);
 504                 strlcpy(temp, tail, sizeof(temp));
 505                 dbg("format=%i, string='%s', tail='%s', class_dev=%p, sysfs_dev=%p",
 506                     type ,string, tail, class_dev, sysfs_device);
 507
 508                 switch (type) {
 509                 case SUBST_DEVPATH:
 510                         strlcat(string, udev->devpath, maxsize);
 511                         dbg("substitute devpath '%s'", udev->devpath);
 512                         break;
 513                 case SUBST_ID:
 514                         strlcat(string, udev->bus_id, maxsize);
 515                         dbg("substitute bus_id '%s'", udev->bus_id);
 516                         break;
 517                 case SUBST_KERNEL_NAME:
 518                         strlcat(string, udev->kernel_name, maxsize);
 519                         dbg("substitute kernel name '%s'", udev->kernel_name);
 520                         break;
 521                 case SUBST_KERNEL_NUMBER:
 522                         strlcat(string, udev->kernel_number, maxsize);
 523                         dbg("substitute kernel number '%s'", udev->kernel_number);
 524                         break;
 525                 case SUBST_MAJOR:
 526                         sprintf(temp2, "%d", major(udev->devt));
 527                         strlcat(string, temp2, maxsize);
 528                         dbg("substitute major number '%s'", temp2);
 529                         break;
 530                 case SUBST_MINOR:
 531                         sprintf(temp2, "%d", minor(udev->devt));
 532                         strlcat(string, temp2, maxsize);
 533                         dbg("substitute minor number '%s'", temp2);
 534                         break;
 535                 case SUBST_RESULT:
 536                         if (udev->program_result[0] == '\0')
 537                                 break;
 538                         /* get part part of the result string */
 539                         i = 0;
 540                         if (attr != NULL)
 541                                 i = strtoul(attr, &rest, 10);
 542                         if (i > 0) {
 543                                 dbg("request part #%d of result string", i);
 544                                 cpos = udev->program_result;
 545                                 while (--i) {
 546                                         while (cpos[0] != '\0' && !isspace(cpos[0]))
 547                                                 cpos++;
 548                                         while (isspace(cpos[0]))
 549                                                 cpos++;
 550                                 }
 551                                 if (i > 0) {
 552                                         err("requested part of result string not found");
 553                                         break;
 554                                 }
 555                                 strlcpy(temp2, cpos, sizeof(temp2));
 556                                 /* %{2+}c copies the whole string from the second part on */
 557                                 if (rest[0] != '+') {
 558                                         cpos = strchr(temp2, ' ');
 559                                         if (cpos)
 560                                                 cpos[0] = '\0';
 561                                 }
 562                                 strlcat(string, temp2, maxsize);
 563                                 dbg("substitute part of result string '%s'", temp2);
 564                         } else {
 565                                 strlcat(string, udev->program_result, maxsize);
 566                                 dbg("substitute result string '%s'", udev->program_result);
 567                         }
 568                         break;
 569                 case SUBST_SYSFS:
 570                         if (attr == NULL) {
 571                                 dbg("missing attribute");
 572                                 break;
 573                         }
 574                         if (find_sysfs_attribute(class_dev, sysfs_device, attr, temp2, sizeof(temp2)) != 0) {
 575                                 struct sysfs_device *parent_device;
 576
 577                                 dbg("sysfs attribute '%s' not found, walk up the physical devices", attr);
 578                                 parent_device = sysfs_get_device_parent(sysfs_device);
 579                                 while (parent_device) {
 580                                         dbg("looking at '%s'", parent_device->path);
 581                                         if (find_sysfs_attribute(NULL, parent_device, attr, temp2, sizeof(temp2)) == 0)
 582                                                 break;
 583                                         parent_device = sysfs_get_device_parent(parent_device);
 584                                 }
 585                                 if (!parent_device)
 586                                         break;
 587                         }
 588                         /* strip trailing whitespace of sysfs value */
 589                         i = strlen(temp2);
 590                         while (i > 0 && isspace(temp2[i-1]))
 591                                 temp2[--i] = '\0';
 592                         count = replace_untrusted_chars(temp2);
 593                         if (count)
 594                                 info("%i untrusted character(s) replaced" , count);
 595                         strlcat(string, temp2, maxsize);
 596                         dbg("substitute sysfs value '%s'", temp2);
 597                         break;
 598                 case SUBST_ENUM:
 599                         next_free_number = find_free_number(string, udev->devpath);
 600                         if (next_free_number > 0) {
 601                                 sprintf(temp2, "%d", next_free_number);
 602                                 strlcat(string, temp2, maxsize);
 603                         }
 604                         break;
 605                 case SUBST_PARENT:
 606                         if (!class_dev)
 607                                 break;
 608                         class_dev_parent = sysfs_get_classdev_parent(class_dev);
 609                         if (class_dev_parent != NULL) {
 610                                 struct udevice udev_parent;
 611
 612                                 dbg("found parent '%s', get the node name", class_dev_parent->path);
 613                                 udev_init_device(&udev_parent, NULL, NULL, NULL);
 614                                 /* lookup the name in the udev_db with the DEVPATH of the parent */
 615                                 if (udev_db_get_device(&udev_parent, &class_dev_parent->path[strlen(sysfs_path)]) == 0) {
 616                                         strlcat(string, udev_parent.name, maxsize);
 617                                         dbg("substitute parent node name'%s'", udev_parent.name);
 618                                 } else
 619                                         dbg("parent not found in database");
 620                                 udev_cleanup_device(&udev_parent);
 621                         }
 622                         break;
 623                 case SUBST_TEMP_NODE:
 624                         if (udev->tmp_node[0] == '\0') {
 625                                 dbg("create temporary device node for callout");
 626                                 snprintf(udev->tmp_node, sizeof(udev->tmp_node), "%s/.tmp-%u-%u",
 627                                          udev_root, major(udev->devt), minor(udev->devt));
 628                                 udev->tmp_node[sizeof(udev->tmp_node)-1] = '\0';
 629                                 udev_make_node(udev, udev->tmp_node, udev->devt, 0600, 0, 0);
 630                         }
 631                         strlcat(string, udev->tmp_node, maxsize);
 632                         dbg("substitute temporary device node name '%s'", udev->tmp_node);
 633                         break;
 634                 case SUBST_ROOT:
 635                         strlcat(string, udev_root, maxsize);
 636                         dbg("substitute udev_root '%s'", udev_root);
 637                         break;
 638                 case SUBST_MODALIAS:
 639                         if (find_sysfs_attribute(NULL, sysfs_device, "modalias", temp2, sizeof(temp2)) != 0)
 640                                 break;
 641                         strlcat(string, temp2, maxsize);
 642                         dbg("substitute MODALIAS '%s'", temp2);
 643                         break;
 644                 case SUBST_ENV:
 645                         if (attr == NULL) {
 646                                 dbg("missing attribute");
 647                                 break;
 648                         }
 649                         pos = getenv(attr);
 650                         if (pos == NULL) {
 651                                 dbg("env '%s' not available", attr);
 652                                 break;
 653                         }
 654                         dbg("substitute env '%s=%s'", attr, pos);
 655                         strlcat(string, pos, maxsize);
 656                         break;
 657                 default:
 658                         err("unknown substitution type=%i", type);
 659                         break;
 660                 }
 661                 /* possibly truncate to format-char specified length */
 662                 if (len != -1) {
 663                         head[len] = '\0';
 664                         dbg("truncate to %i chars, subtitution string becomes '%s'", len, head);
 665                 }
 666                 strlcat(string, temp, maxsize);
 667         }
 668 }
 669
 670 static char *key_val(struct udev_rule *rule, struct key *key)
 671 {
 672         return rule->buf + key->val_off;
 673 }
 674
 675 static char *key_pair_name(struct udev_rule *rule, struct key_pair *pair)
 676 {
 677         return rule->buf + pair->key_name_off;
 678 }
 679
 680 static int match_key(const char *key_name, struct udev_rule *rule, struct key *key, const char *val)
 681 {
 682         int match;
 683         char value[PATH_SIZE];
 684         char *key_value;
 685         char *pos;
 686
 687         if (key->operation == KEY_OP_UNSET)
 688                 return 0;
 689
 690         strlcpy(value, rule->buf + key->val_off, sizeof(value));
 691         key_value = value;
 692
 693         dbg("key %s value='%s'", key_name, key_value);
 694         while (key_value) {
 695                 pos = strchr(key_value, '|');
 696                 if (pos) {
 697                         pos[0] = '\0';
 698                         pos++;
 699                 }
 700                 dbg("match %s '%s' <-> '%s'", key_name, key_value, val);
 701                 match = (strcmp_pattern(key_value, val) == 0);
 702                 if (match && (key->operation != KEY_OP_NOMATCH)) {
 703                         dbg("%s is true (matching value)", key_name);
 704                         return 0;
 705                 }
 706                 if (!match && (key->operation == KEY_OP_NOMATCH)) {
 707                         dbg("%s is true (non-matching value)", key_name);
 708                         return 0;
 709                 }
 710                 key_value = pos;
 711         }
 712         dbg("%s is false", key_name);
 713         return -1;
 714 }
 715
 716 /* match a single rule against a given device and possibly its parent devices */
 717 static int match_rule(struct udevice *udev, struct udev_rule *rule,
 718                       struct sysfs_class_device *class_dev, struct sysfs_device *sysfs_device)
 719 {
 720         struct sysfs_device *parent_device = sysfs_device;
 721         int i;
 722
 723         if (match_key("ACTION", rule, &rule->action, udev->action))
 724                 goto exit;
 725
 726         if (match_key("KERNEL", rule, &rule->kernel_name, udev->kernel_name))
 727                 goto exit;
 728
 729         if (match_key("SUBSYSTEM", rule, &rule->subsystem, udev->subsystem))
 730                 goto exit;
 731
 732         if (match_key("DEVPATH", rule, &rule->devpath, udev->devpath))
 733                 goto exit;
 734
 735         if (rule->modalias.operation != KEY_OP_UNSET) {
 736                 char value[NAME_SIZE];
 737
 738                 if (find_sysfs_attribute(NULL, sysfs_device, "modalias", value, sizeof(value)) != 0) {
 739                         dbg("MODALIAS value not found");
 740                         goto exit;
 741                 }
 742                 if (match_key("MODALIAS", rule, &rule->modalias, value))
 743                         goto exit;
 744         }
 745
 746         for (i = 0; i < rule->env.count; i++) {
 747                 struct key_pair *pair = &rule->env.keys[i];
 748
 749                 /* we only check for matches, assignments will be handled later */
 750                 if (pair->key.operation != KEY_OP_ASSIGN) {
 751                         const char *key_name = key_pair_name(rule, pair);
 752                         const char *value = getenv(key_name);
 753
 754                         if (!value) {
 755                                 dbg("ENV{'%s'} is not set, treat as empty", key_name);
 756                                 value = "";
 757                         }
 758                         if (match_key("ENV", rule, &pair->key, value))
 759                                 goto exit;
 760                 }
 761         }
 762
 763         if (rule->wait_for_sysfs.operation != KEY_OP_UNSET) {
 764                 int match;
 765
 766                 match = (wait_for_sysfs(udev, key_val(rule, &rule->wait_for_sysfs), 3) == 0);
 767                 if (match && (rule->wait_for_sysfs.operation != KEY_OP_NOMATCH)) {
 768                         dbg("WAIT_FOR_SYSFS is true (matching value)");
 769                         return 0;
 770                 }
 771                 if (!match && (rule->wait_for_sysfs.operation == KEY_OP_NOMATCH)) {
 772                         dbg("WAIT_FOR_SYSFS is true, (non matching value)");
 773                         return 0;
 774                 }
 775                 dbg("WAIT_FOR_SYSFS is false");
 776                 return -1;
 777         }
 778
 779         /* walk up the chain of physical devices and find a match */
 780         while (1) {
 781                 /* check for matching driver */
 782                 if (rule->driver.operation != KEY_OP_UNSET) {
 783                         if (parent_device == NULL) {
 784                                 dbg("device has no sysfs_device");
 785                                 goto exit;
 786                         }
 787                         if (match_key("DRIVER", rule, &rule->driver, parent_device->driver_name))
 788                                 goto try_parent;
 789                 }
 790
 791                 /* check for matching bus value */
 792                 if (rule->bus.operation != KEY_OP_UNSET) {
 793                         if (parent_device == NULL) {
 794                                 dbg("device has no sysfs_device");
 795                                 goto exit;
 796                         }
 797                         if (match_key("BUS", rule, &rule->bus, parent_device->bus))
 798                                 goto try_parent;
 799                 }
 800
 801                 /* check for matching bus id */
 802                 if (rule->id.operation != KEY_OP_UNSET) {
 803                         if (parent_device == NULL) {
 804                                 dbg("device has no sysfs_device");
 805                                 goto exit;
 806                         }
 807                         if (match_key("ID", rule, &rule->id, parent_device->bus_id))
 808                                 goto try_parent;
 809                 }
 810
 811                 /* check for matching sysfs pairs */
 812                 if (rule->sysfs.count) {
 813                         dbg("check %i SYSFS keys", rule->sysfs.count);
 814                         for (i = 0; i < rule->sysfs.count; i++) {
 815                                 struct key_pair *pair = &rule->sysfs.keys[i];
 816                                 const char *key_name = key_pair_name(rule, pair);
 817                                 const char *key_value = key_val(rule, &pair->key);
 818                                 char value[VALUE_SIZE];
 819                                 size_t len;
 820
 821                                 if (find_sysfs_attribute(class_dev, parent_device, key_name, value, sizeof(value)) != 0)
 822                                         goto try_parent;
 823
 824                                 /* strip trailing whitespace of value, if not asked to match for it */
 825                                 len = strlen(key_value);
 826                                 if (len && !isspace(key_value[len-1])) {
 827                                         len = strlen(value);
 828                                         while (len > 0 && isspace(value[len-1]))
 829                                                 value[--len] = '\0';
 830                                         dbg("removed %zi trailing whitespace chars from '%s'", strlen(value)-len, value);
 831                                 }
 832
 833                                 if (match_key("SYSFS", rule, &pair->key, value))
 834                                         goto try_parent;
 835                         }
 836                         dbg("all %i SYSFS keys matched", rule->sysfs.count);
 837                 }
 838
 839                 /* found matching physical device  */
 840                 break;
 841 try_parent:
 842                 dbg("try parent sysfs device");
 843                 parent_device = sysfs_get_device_parent(parent_device);
 844                 if (parent_device == NULL)
 845                         goto exit;
 846                 dbg("look at sysfs_device->path='%s'", parent_device->path);
 847                 dbg("look at sysfs_device->bus_id='%s'", parent_device->bus_id);
 848         }
 849
 850         /* execute external program */
 851         if (rule->program.operation != KEY_OP_UNSET) {
 852                 char program[PATH_SIZE];
 853                 char result[PATH_SIZE];
 854
 855                 strlcpy(program, key_val(rule, &rule->program), sizeof(program));
 856                 apply_format(udev, program, sizeof(program), class_dev, sysfs_device);
 857                 if (run_program(program, udev->subsystem, result, sizeof(result), NULL, (udev_log_priority >= LOG_INFO)) != 0) {
 858                         dbg("PROGRAM is false");
 859                         udev->program_result[0] = '\0';
 860                         if (rule->program.operation != KEY_OP_NOMATCH)
 861                                 goto exit;
 862                 } else {
 863                         int count;
 864
 865                         dbg("PROGRAM matches");
 866                         remove_trailing_chars(result, '\n');
 867                         count = replace_untrusted_chars(result);
 868                         if (count)
 869                                 info("%i untrusted character(s) replaced" , count);
 870                         dbg("result is '%s'", result);
 871                         strlcpy(udev->program_result, result, sizeof(udev->program_result));
 872                         dbg("PROGRAM returned successful");
 873                         if (rule->program.operation == KEY_OP_NOMATCH)
 874                                 goto exit;
 875                 }
 876                 dbg("PROGRAM key is true");
 877         }
 878
 879         /* check for matching result of external program */
 880         if (match_key("RESULT", rule, &rule->result, udev->program_result))
 881                 goto exit;
 882
 883         /* import variables returned from program or or file into environment */
 884         if (rule->import.operation != KEY_OP_UNSET) {
 885                 char import[PATH_SIZE];
 886                 int rc = -1;
 887
 888                 strlcpy(import, key_val(rule, &rule->import), sizeof(import));
 889                 apply_format(udev, import, sizeof(import), class_dev, sysfs_device);
 890                 dbg("check for IMPORT import='%s'", import);
 891                 if (rule->import_type == IMPORT_PROGRAM) {
 892                         rc = import_program_into_env(udev, import);
 893                 } else if (rule->import_type == IMPORT_FILE) {
 894                         dbg("import file import='%s'", import);
 895                         rc = import_file_into_env(udev, import);
 896                 } else if (rule->import_type == IMPORT_PARENT && class_dev) {
 897                         dbg("import parent import='%s'", import);
 898                         rc = import_parent_into_env(udev, class_dev, import);
 899                 }
 900                 if (rc) {
 901                         dbg("IMPORT failed");
 902                         if (rule->import.operation != KEY_OP_NOMATCH)
 903                                 goto exit;
 904                 } else
 905                         dbg("IMPORT '%s' imported", key_val(rule, &rule->import));
 906                 dbg("IMPORT key is true");
 907         }
 908
 909         /* rule matches, if we have ENV assignments export it */
 910         for (i = 0; i < rule->env.count; i++) {
 911                 struct key_pair *pair = &rule->env.keys[i];
 912
 913                 if (pair->key.operation == KEY_OP_ASSIGN) {
 914                         const char *key_name = key_pair_name(rule, pair);
 915                         const char *value = key_val(rule, &pair->key);
 916
 917                         name_list_key_add(&udev->env_list, key_name, value);
 918                         setenv(key_name, value, 1);
 919                         dbg("export ENV '%s=%s'", key_name, value);
 920                 }
 921         }
 922
 923         return 0;
 924
 925 exit:
 926         return -1;
 927 }
 928
 929 int udev_rules_get_name(struct udev_rules *rules, struct udevice *udev, struct sysfs_class_device *class_dev)
 930 {
 931         struct sysfs_class_device *class_dev_parent;
 932         struct sysfs_device *sysfs_device = NULL;
 933         struct udev_rule *rule;
 934         int name_set = 0;
 935
 936         dbg("class_dev->name='%s'", class_dev->name);
 937
 938         /* Figure out where the "device"-symlink is at.  For char devices this will
 939          * always be in the class_dev->path.  On block devices, only the main block
 940          * device will have the device symlink in it's path. All partition devices
 941          * need to look at the symlink in its parent directory.
 942          */
 943         class_dev_parent = sysfs_get_classdev_parent(class_dev);
 944         if (class_dev_parent != NULL) {
 945                 dbg("given class device has a parent, use this instead");
 946                 sysfs_device = sysfs_get_classdev_device(class_dev_parent);
 947         } else {
 948                 sysfs_device = sysfs_get_classdev_device(class_dev);
 949         }
 950
 951         if (sysfs_device) {
 952                 dbg("found devices device: path='%s', bus_id='%s', bus='%s'",
 953                     sysfs_device->path, sysfs_device->bus_id, sysfs_device->bus);
 954                 strlcpy(udev->bus_id, sysfs_device->bus_id, sizeof(udev->bus_id));
 955         }
 956
 957         dbg("udev->kernel_name='%s'", udev->kernel_name);
 958
 959         /* look for a matching rule to apply */
 960         udev_rules_iter_init(rules);
 961         while (1) {
 962                 rule = udev_rules_iter_next(rules);
 963                 if (rule == NULL)
 964                         break;
 965
 966                 if (name_set && rule->name.operation != KEY_OP_UNSET) {
 967                         dbg("node name already set, rule ignored");
 968                         continue;
 969                 }
 970
 971                 dbg("process rule");
 972                 if (match_rule(udev, rule, class_dev, sysfs_device) == 0) {
 973                         /* apply options */
 974                         if (rule->ignore_device) {
 975                                 info("rule applied, '%s' is ignored", udev->kernel_name);
 976                                 udev->ignore_device = 1;
 977                                 return 0;
 978                         }
 979                         if (rule->ignore_remove) {
 980                                 udev->ignore_remove = 1;
 981                                 dbg("remove event should be ignored");
 982                         }
 983                         /* apply all_partitions option only at a main block device */
 984                         if (rule->partitions && udev->type == DEV_BLOCK && udev->kernel_number[0] == '\0') {
 985                                 udev->partitions = rule->partitions;
 986                                 dbg("creation of partition nodes requested");
 987                         }
 988
 989                         /* apply permissions */
 990                         if (!udev->mode_final && rule->mode != 0000) {
 991                                 if (rule->mode_operation == KEY_OP_ASSIGN_FINAL)
 992                                         udev->mode_final = 1;
 993                                 udev->mode = rule->mode;
 994                                 dbg("applied mode=%#o to '%s'", rule->mode, udev->kernel_name);
 995                         }
 996                         if (!udev->owner_final && rule->owner.operation != KEY_OP_UNSET) {
 997                                 if (rule->owner.operation == KEY_OP_ASSIGN_FINAL)
 998                                         udev->owner_final = 1;
 999                                 strlcpy(udev->owner, key_val(rule, &rule->owner), sizeof(udev->owner));
1000                                 apply_format(udev, udev->owner, sizeof(udev->owner), class_dev, sysfs_device);
1001                                 dbg("applied owner='%s' to '%s'", udev->owner, udev->kernel_name);
1002                         }
1003                         if (!udev->group_final && rule->group.operation != KEY_OP_UNSET) {
1004                                 if (rule->group.operation == KEY_OP_ASSIGN_FINAL)
1005                                         udev->group_final = 1;
1006                                 strlcpy(udev->group, key_val(rule, &rule->group), sizeof(udev->group));
1007                                 apply_format(udev, udev->group, sizeof(udev->group), class_dev, sysfs_device);
1008                                 dbg("applied group='%s' to '%s'", udev->group, udev->kernel_name);
1009                         }
1010
1011                         /* collect symlinks */
1012                         if (!udev->symlink_final && rule->symlink.operation != KEY_OP_UNSET) {
1013                                 char temp[PATH_SIZE];
1014                                 char *pos, *next;
1015                                 int count;
1016
1017                                 if (rule->symlink.operation == KEY_OP_ASSIGN_FINAL)
1018                                         udev->symlink_final = 1;
1019                                 if (rule->symlink.operation == KEY_OP_ASSIGN || rule->symlink.operation == KEY_OP_ASSIGN_FINAL) {
1020                                         info("reset symlink list");
1021                                         name_list_cleanup(&udev->symlink_list);
1022                                 }
1023                                 strlcpy(temp, key_val(rule, &rule->symlink), sizeof(temp));
1024                                 apply_format(udev, temp, sizeof(temp), class_dev, sysfs_device);
1025                                 count = replace_untrusted_chars(temp);
1026                                 if (count)
1027                                         info("%i untrusted character(s) replaced" , count);
1028                                 dbg("rule applied, added symlink(s) '%s'", temp);
1029
1030                                 /* add multiple symlinks separated by spaces */
1031                                 pos = temp;
1032                                 while (isspace(pos[0]))
1033                                         pos++;
1034                                 next = strchr(pos, ' ');
1035                                 while (next) {
1036                                         next[0] = '\0';
1037                                         info("add symlink '%s'", pos);
1038                                         name_list_add(&udev->symlink_list, pos, 0);
1039                                         while (isspace(next[1]))
1040                                                 next++;
1041                                         pos = &next[1];
1042                                         next = strchr(pos, ' ');
1043                                 }
1044                                 if (pos[0] != '\0') {
1045                                         info("add symlink '%s'", pos);
1046                                         name_list_add(&udev->symlink_list, pos, 0);
1047                                 }
1048                         }
1049
1050                         /* set name, later rules with name set will be ignored */
1051                         if (rule->name.operation != KEY_OP_UNSET) {
1052                                 int count;
1053                                 name_set = 1;
1054                                 strlcpy(udev->name, key_val(rule, &rule->name), sizeof(udev->name));
1055                                 apply_format(udev, udev->name, sizeof(udev->name), class_dev, sysfs_device);
1056                                 count = replace_untrusted_chars(udev->name);
1057                                 if (count)
1058                                         info("%i untrusted character(s) replaced", count);
1059
1060                                 info("rule applied, '%s' becomes '%s'", udev->kernel_name, udev->name);
1061                                 if (udev->type != DEV_NET)
1062                                         dbg("name, '%s' is going to have owner='%s', group='%s', mode=%#o partitions=%i",
1063                                             udev->name, udev->owner, udev->group, udev->mode, udev->partitions);
1064                         }
1065
1066                         if (!udev->run_final && rule->run.operation != KEY_OP_UNSET) {
1067                                 char program[PATH_SIZE];
1068
1069                                 if (rule->run.operation == KEY_OP_ASSIGN_FINAL)
1070                                         udev->run_final = 1;
1071                                 if (rule->run.operation == KEY_OP_ASSIGN || rule->run.operation == KEY_OP_ASSIGN_FINAL) {
1072                                         info("reset run list");
1073                                         name_list_cleanup(&udev->run_list);
1074                                 }
1075                                 strlcpy(program, key_val(rule, &rule->run), sizeof(program));
1076                                 apply_format(udev, program, sizeof(program), class_dev, sysfs_device);
1077                                 dbg("add run '%s'", program);
1078                                 name_list_add(&udev->run_list, program, 0);
1079                         }
1080
1081                         if (rule->last_rule) {
1082                                 dbg("last rule to be applied");
1083                                 break;
1084                         }
1085
1086                         if (rule->goto_label.operation != KEY_OP_UNSET) {
1087                                 dbg("moving forward to label '%s'", key_val(rule, &rule->goto_label));
1088                                 udev_rules_iter_label(rules, key_val(rule, &rule->goto_label));
1089                         }
1090                 }
1091         }
1092
1093         if (!name_set) {
1094                 strlcpy(udev->name, udev->kernel_name, sizeof(udev->name));
1095                 info("no node name set, will use kernel name '%s'", udev->name);
1096         }
1097
1098         if (udev->tmp_node[0] != '\0') {
1099                 dbg("removing temporary device node");
1100                 unlink_secure(udev->tmp_node);
1101                 udev->tmp_node[0] = '\0';
1102         }
1103
1104         return 0;
1105 }
1106
1107 int udev_rules_get_run(struct udev_rules *rules, struct udevice *udev,
1108                        struct sysfs_class_device *class_dev, struct sysfs_device *sysfs_dev)
1109 {
1110         struct udev_rule *rule;
1111
1112         if (class_dev && !sysfs_dev)
1113                 sysfs_dev = sysfs_get_classdev_device(class_dev);
1114         if (sysfs_dev) {
1115                 dbg("found devices device: path='%s', bus_id='%s', bus='%s'",
1116                     sysfs_dev->path, sysfs_dev->bus_id, sysfs_dev->bus);
1117                 strlcpy(udev->bus_id, sysfs_dev->bus_id, sizeof(udev->bus_id));
1118         }
1119
1120         dbg("udev->kernel_name='%s'", udev->kernel_name);
1121
1122         /* look for a matching rule to apply */
1123         udev_rules_iter_init(rules);
1124         while (1) {
1125                 rule = udev_rules_iter_next(rules);
1126                 if (rule == NULL)
1127                         break;
1128
1129                 dbg("process rule");
1130                 if (rule->name.operation != KEY_OP_UNSET || rule->symlink.operation != KEY_OP_UNSET ||
1131                     rule->mode_operation != KEY_OP_UNSET || rule->owner.operation != KEY_OP_UNSET || rule->group.operation != KEY_OP_UNSET) {
1132                         dbg("skip rule that names a device");
1133                         continue;
1134                 }
1135
1136                 if (match_rule(udev, rule, class_dev, sysfs_dev) == 0) {
1137                         if (rule->ignore_device) {
1138                                 info("rule applied, '%s' is ignored", udev->kernel_name);
1139                                 udev->ignore_device = 1;
1140                                 return 0;
1141                         }
1142
1143                         if (!udev->run_final && rule->run.operation != KEY_OP_UNSET) {
1144                                 char program[PATH_SIZE];
1145
1146                                 if (rule->run.operation == KEY_OP_ASSIGN || rule->run.operation == KEY_OP_ASSIGN_FINAL) {
1147                                         info("reset run list");
1148                                         name_list_cleanup(&udev->run_list);
1149                                 }
1150                                 strlcpy(program, key_val(rule, &rule->run), sizeof(program));
1151                                 apply_format(udev, program, sizeof(program), class_dev, sysfs_dev);
1152                                 dbg("add run '%s'", program);
1153                                 name_list_add(&udev->run_list, program, 0);
1154                                 if (rule->run.operation == KEY_OP_ASSIGN_FINAL)
1155                                         break;
1156                         }
1157
1158                         if (rule->last_rule) {
1159                                 dbg("last rule to be applied");
1160                                 break;
1161                         }
1162
1163                         if (rule->goto_label.operation != KEY_OP_UNSET) {
1164                                 dbg("moving forward to label '%s'", key_val(rule, &rule->goto_label));
1165                                 udev_rules_iter_label(rules, key_val(rule, &rule->goto_label));
1166                         }
1167                 }
1168         }
1169
1170         return 0;
1171 }