1 /* 2 * Create a squashfs filesystem. This is a highly compressed read only 3 * filesystem. 4 * 5 * Copyright (c) 2009, 2010, 2012, 2014 6 * Phillip Lougher <phillip (at) squashfs.org.uk> 7 * 8 * This program is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU General Public License 10 * as published by the Free Software Foundation; either version 2, 11 * or (at your option) any later version. 12 * 13 * This program is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 * GNU General Public License for more details. 17 * 18 * You should have received a copy of the GNU General Public License 19 * along with this program; if not, write to the Free Software 20 * Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. 21 * 22 * pseudo.c 23 */ 24 25 #include <pwd.h> 26 #include <grp.h> 27 #include <unistd.h> 28 #include <stdio.h> 29 #include <fcntl.h> 30 #include <errno.h> 31 #include <string.h> 32 #include <stdlib.h> 33 #include <sys/stat.h> 34 #include <sys/types.h> 35 #include <sys/wait.h> 36 #include <ctype.h> 37 38 #include "pseudo.h" 39 #include "error.h" 40 #include "progressbar.h" 41 42 #define TRUE 1 43 #define FALSE 0 44 45 extern int read_file(char *filename, char *type, int (parse_line)(char *)); 46 47 struct pseudo_dev **pseudo_file = NULL; 48 struct pseudo *pseudo = NULL; 49 int pseudo_count = 0; 50 51 static char *get_component(char *target, char **targname) 52 { 53 char *start; 54 55 while(*target == '/') 56 target ++; 57 58 start = target; 59 while(*target != '/' && *target != '\0') 60 target ++; 61 62 *targname = strndup(start, target - start); 63 64 while(*target == '/') 65 target ++; 66 67 return target; 68 } 69 70 71 /* 72 * Add pseudo device target to the set of pseudo devices. Pseudo_dev 73 * describes the pseudo device attributes. 74 */ 75 struct pseudo *add_pseudo(struct pseudo *pseudo, struct pseudo_dev *pseudo_dev, 76 char *target, char *alltarget) 77 { 78 char *targname; 79 int i; 80 81 target = get_component(target, &targname); 82 83 if(pseudo == NULL) { 84 pseudo = malloc(sizeof(struct pseudo)); 85 if(pseudo == NULL) 86 MEM_ERROR(); 87 88 pseudo->names = 0; 89 pseudo->count = 0; 90 pseudo->name = NULL; 91 } 92 93 for(i = 0; i < pseudo->names; i++) 94 if(strcmp(pseudo->name[i].name, targname) == 0) 95 break; 96 97 if(i == pseudo->names) { 98 /* allocate new name entry */ 99 pseudo->names ++; 100 pseudo->name = realloc(pseudo->name, (i + 1) * 101 sizeof(struct pseudo_entry)); 102 if(pseudo->name == NULL) 103 MEM_ERROR(); 104 pseudo->name[i].name = targname; 105 106 if(target[0] == '\0') { 107 /* at leaf pathname component */ 108 pseudo->name[i].pseudo = NULL; 109 pseudo->name[i].pathname = strdup(alltarget); 110 pseudo->name[i].dev = pseudo_dev; 111 } else { 112 /* recurse adding child components */ 113 pseudo->name[i].dev = NULL; 114 pseudo->name[i].pseudo = add_pseudo(NULL, pseudo_dev, 115 target, alltarget); 116 } 117 } else { 118 /* existing matching entry */ 119 free(targname); 120 121 if(pseudo->name[i].pseudo == NULL) { 122 /* No sub-directory which means this is the leaf 123 * component of a pre-existing pseudo file. 124 */ 125 if(target[0] != '\0') { 126 /* 127 * entry must exist as either a 'd' type or 128 * 'm' type pseudo file 129 */ 130 if(pseudo->name[i].dev->type == 'd' || 131 pseudo->name[i].dev->type == 'm') 132 /* recurse adding child components */ 133 pseudo->name[i].pseudo = 134 add_pseudo(NULL, pseudo_dev, 135 target, alltarget); 136 else { 137 ERROR_START("%s already exists as a " 138 "non directory.", 139 pseudo->name[i].name); 140 ERROR_EXIT(". Ignoring %s!\n", 141 alltarget); 142 } 143 } else if(memcmp(pseudo_dev, pseudo->name[i].dev, 144 sizeof(struct pseudo_dev)) != 0) { 145 ERROR_START("%s already exists as a different " 146 "pseudo definition.", alltarget); 147 ERROR_EXIT(" Ignoring!\n"); 148 } else { 149 ERROR_START("%s already exists as an identical " 150 "pseudo definition!", alltarget); 151 ERROR_EXIT(" Ignoring!\n"); 152 } 153 } else { 154 if(target[0] == '\0') { 155 /* 156 * sub-directory exists, which means we can only 157 * add a pseudo file of type 'd' or type 'm' 158 */ 159 if(pseudo->name[i].dev == NULL && 160 (pseudo_dev->type == 'd' || 161 pseudo_dev->type == 'm')) { 162 pseudo->name[i].pathname = 163 strdup(alltarget); 164 pseudo->name[i].dev = pseudo_dev; 165 } else { 166 ERROR_START("%s already exists as a " 167 "different pseudo definition.", 168 pseudo->name[i].name); 169 ERROR_EXIT(" Ignoring %s!\n", 170 alltarget); 171 } 172 } else 173 /* recurse adding child components */ 174 add_pseudo(pseudo->name[i].pseudo, pseudo_dev, 175 target, alltarget); 176 } 177 } 178 179 return pseudo; 180 } 181 182 183 /* 184 * Find subdirectory in pseudo directory referenced by pseudo, matching 185 * filename. If filename doesn't exist or if filename is a leaf file 186 * return NULL 187 */ 188 struct pseudo *pseudo_subdir(char *filename, struct pseudo *pseudo) 189 { 190 int i; 191 192 if(pseudo == NULL) 193 return NULL; 194 195 for(i = 0; i < pseudo->names; i++) 196 if(strcmp(filename, pseudo->name[i].name) == 0) 197 return pseudo->name[i].pseudo; 198 199 return NULL; 200 } 201 202 203 struct pseudo_entry *pseudo_readdir(struct pseudo *pseudo) 204 { 205 if(pseudo == NULL) 206 return NULL; 207 208 while(pseudo->count < pseudo->names) { 209 if(pseudo->name[pseudo->count].dev != NULL) 210 return &pseudo->name[pseudo->count++]; 211 else 212 pseudo->count++; 213 } 214 215 return NULL; 216 } 217 218 219 int pseudo_exec_file(struct pseudo_dev *dev, int *child) 220 { 221 int res, pipefd[2]; 222 223 res = pipe(pipefd); 224 if(res == -1) { 225 ERROR("Executing dynamic pseudo file, pipe failed\n"); 226 return 0; 227 } 228 229 *child = fork(); 230 if(*child == -1) { 231 ERROR("Executing dynamic pseudo file, fork failed\n"); 232 goto failed; 233 } 234 235 if(*child == 0) { 236 close(pipefd[0]); 237 close(STDOUT_FILENO); 238 res = dup(pipefd[1]); 239 if(res == -1) 240 exit(EXIT_FAILURE); 241 242 execl("/bin/sh", "sh", "-c", dev->command, (char *) NULL); 243 exit(EXIT_FAILURE); 244 } 245 246 close(pipefd[1]); 247 return pipefd[0]; 248 249 failed: 250 close(pipefd[0]); 251 close(pipefd[1]); 252 return 0; 253 } 254 255 256 void add_pseudo_file(struct pseudo_dev *dev) 257 { 258 pseudo_file = realloc(pseudo_file, (pseudo_count + 1) * 259 sizeof(struct pseudo_dev *)); 260 if(pseudo_file == NULL) 261 MEM_ERROR(); 262 263 dev->pseudo_id = pseudo_count; 264 pseudo_file[pseudo_count ++] = dev; 265 } 266 267 268 struct pseudo_dev *get_pseudo_file(int pseudo_id) 269 { 270 return pseudo_file[pseudo_id]; 271 } 272 273 274 int read_pseudo_def(char *def) 275 { 276 int n, bytes; 277 unsigned int major = 0, minor = 0, mode; 278 char type, *ptr; 279 char suid[100], sgid[100]; /* overflow safe */ 280 char *filename, *name; 281 char *orig_def = def; 282 long long uid, gid; 283 struct pseudo_dev *dev; 284 285 /* 286 * Scan for filename, don't use sscanf() and "%s" because 287 * that can't handle filenames with spaces 288 */ 289 filename = malloc(strlen(def) + 1); 290 if(filename == NULL) 291 MEM_ERROR(); 292 293 for(name = filename; !isspace(*def) && *def != '\0';) { 294 if(*def == '\\') { 295 def ++; 296 if (*def == '\0') 297 break; 298 } 299 *name ++ = *def ++; 300 } 301 *name = '\0'; 302 303 if(*filename == '\0') { 304 ERROR("Not enough or invalid arguments in pseudo file " 305 "definition \"%s\"\n", orig_def); 306 goto error; 307 } 308 309 n = sscanf(def, " %c %o %99s %99s %n", &type, &mode, suid, sgid, 310 &bytes); 311 def += bytes; 312 313 if(n < 4) { 314 ERROR("Not enough or invalid arguments in pseudo file " 315 "definition \"%s\"\n", orig_def); 316 switch(n) { 317 case -1: 318 /* FALLTHROUGH */ 319 case 0: 320 ERROR("Read filename, but failed to read or match " 321 "type\n"); 322 break; 323 case 1: 324 ERROR("Read filename and type, but failed to read or " 325 "match octal mode\n"); 326 break; 327 case 2: 328 ERROR("Read filename, type and mode, but failed to " 329 "read or match uid\n"); 330 break; 331 default: 332 ERROR("Read filename, type, mode and uid, but failed " 333 "to read or match gid\n"); 334 break; 335 } 336 goto error; 337 } 338 339 switch(type) { 340 case 'b': 341 /* FALLTHROUGH */ 342 case 'c': 343 n = sscanf(def, "%u %u %n", &major, &minor, &bytes); 344 def += bytes; 345 346 if(n < 2) { 347 ERROR("Not enough or invalid arguments in %s device " 348 "pseudo file definition \"%s\"\n", type == 'b' ? 349 "block" : "character", orig_def); 350 if(n < 1) 351 ERROR("Read filename, type, mode, uid and gid, " 352 "but failed to read or match major\n"); 353 else 354 ERROR("Read filename, type, mode, uid, gid " 355 "and major, but failed to read or " 356 "match minor\n"); 357 goto error; 358 } 359 360 if(major > 0xfff) { 361 ERROR("Major %d out of range\n", major); 362 goto error; 363 } 364 365 if(minor > 0xfffff) { 366 ERROR("Minor %d out of range\n", minor); 367 goto error; 368 } 369 /* FALLTHROUGH */ 370 case 'd': 371 /* FALLTHROUGH */ 372 case 'm': 373 /* 374 * Check for trailing junk after expected arguments 375 */ 376 if(def[0] != '\0') { 377 ERROR("Unexpected tailing characters in pseudo file " 378 "definition \"%s\"\n", orig_def); 379 goto error; 380 } 381 break; 382 case 'f': 383 if(def[0] == '\0') { 384 ERROR("Not enough arguments in dynamic file pseudo " 385 "definition \"%s\"\n", orig_def); 386 ERROR("Expected command, which can be an executable " 387 "or a piece of shell script\n"); 388 goto error; 389 } 390 break; 391 default: 392 ERROR("Unsupported type %c\n", type); 393 goto error; 394 } 395 396 397 if(mode > 07777) { 398 ERROR("Mode %o out of range\n", mode); 399 goto error; 400 } 401 402 uid = strtoll(suid, &ptr, 10); 403 if(*ptr == '\0') { 404 if(uid < 0 || uid > ((1LL << 32) - 1)) { 405 ERROR("Uid %s out of range\n", suid); 406 goto error; 407 } 408 } else { 409 struct passwd *pwuid = getpwnam(suid); 410 if(pwuid) 411 uid = pwuid->pw_uid; 412 else { 413 ERROR("Uid %s invalid uid or unknown user\n", suid); 414 goto error; 415 } 416 } 417 418 gid = strtoll(sgid, &ptr, 10); 419 if(*ptr == '\0') { 420 if(gid < 0 || gid > ((1LL << 32) - 1)) { 421 ERROR("Gid %s out of range\n", sgid); 422 goto error; 423 } 424 } else { 425 struct group *grgid = getgrnam(sgid); 426 if(grgid) 427 gid = grgid->gr_gid; 428 else { 429 ERROR("Gid %s invalid uid or unknown user\n", sgid); 430 goto error; 431 } 432 } 433 434 switch(type) { 435 case 'b': 436 mode |= S_IFBLK; 437 break; 438 case 'c': 439 mode |= S_IFCHR; 440 break; 441 case 'd': 442 mode |= S_IFDIR; 443 break; 444 case 'f': 445 mode |= S_IFREG; 446 break; 447 } 448 449 dev = malloc(sizeof(struct pseudo_dev)); 450 if(dev == NULL) 451 MEM_ERROR(); 452 453 dev->type = type; 454 dev->mode = mode; 455 dev->uid = uid; 456 dev->gid = gid; 457 dev->major = major; 458 dev->minor = minor; 459 if(type == 'f') { 460 dev->command = strdup(def); 461 add_pseudo_file(dev); 462 } 463 464 pseudo = add_pseudo(pseudo, dev, filename, filename); 465 466 free(filename); 467 return TRUE; 468 469 error: 470 ERROR("Pseudo definitions should be of format\n"); 471 ERROR("\tfilename d mode uid gid\n"); 472 ERROR("\tfilename m mode uid gid\n"); 473 ERROR("\tfilename b mode uid gid major minor\n"); 474 ERROR("\tfilename c mode uid gid major minor\n"); 475 ERROR("\tfilename f mode uid command\n"); 476 free(filename); 477 return FALSE; 478 } 479 480 481 int read_pseudo_file(char *filename) 482 { 483 return read_file(filename, "pseudo", read_pseudo_def); 484 } 485 486 487 struct pseudo *get_pseudo() 488 { 489 return pseudo; 490 } 491 492 493 #ifdef SQUASHFS_TRACE 494 static void dump_pseudo(struct pseudo *pseudo, char *string) 495 { 496 int i, res; 497 char *path; 498 499 for(i = 0; i < pseudo->names; i++) { 500 struct pseudo_entry *entry = &pseudo->name[i]; 501 if(string) { 502 res = asprintf(&path, "%s/%s", string, entry->name); 503 if(res == -1) 504 BAD_ERROR("asprintf failed in dump_pseudo\n"); 505 } else 506 path = entry->name; 507 if(entry->dev) 508 ERROR("%s %c 0%o %d %d %d %d\n", path, entry->dev->type, 509 entry->dev->mode & ~S_IFMT, entry->dev->uid, 510 entry->dev->gid, entry->dev->major, 511 entry->dev->minor); 512 if(entry->pseudo) 513 dump_pseudo(entry->pseudo, path); 514 if(string) 515 free(path); 516 } 517 } 518 519 520 void dump_pseudos() 521 { 522 if (pseudo) 523 dump_pseudo(pseudo, NULL); 524 } 525 #else 526 void dump_pseudos() 527 { 528 } 529 #endif 530
