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