archive_read_support_format_ar.c revision 311041
1/*- 2 * Copyright (c) 2007 Kai Wang 3 * Copyright (c) 2007 Tim Kientzle 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer 11 * in this position and unchanged. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28#include "archive_platform.h" 29__FBSDID("$FreeBSD: stable/11/contrib/libarchive/libarchive/archive_read_support_format_ar.c 311041 2017-01-02 01:41:31Z mm $"); 30 31#ifdef HAVE_SYS_STAT_H 32#include <sys/stat.h> 33#endif 34#ifdef HAVE_ERRNO_H 35#include <errno.h> 36#endif 37#ifdef HAVE_STDLIB_H 38#include <stdlib.h> 39#endif 40#ifdef HAVE_STRING_H 41#include <string.h> 42#endif 43#ifdef HAVE_LIMITS_H 44#include <limits.h> 45#endif 46 47#include "archive.h" 48#include "archive_entry.h" 49#include "archive_private.h" 50#include "archive_read_private.h" 51 52struct ar { 53 int64_t entry_bytes_remaining; 54 /* unconsumed is purely to track data we've gotten from readahead, 55 * but haven't yet marked as consumed. Must be paired with 56 * entry_bytes_remaining usage/modification. 57 */ 58 size_t entry_bytes_unconsumed; 59 int64_t entry_offset; 60 int64_t entry_padding; 61 char *strtab; 62 size_t strtab_size; 63 char read_global_header; 64}; 65 66/* 67 * Define structure of the "ar" header. 68 */ 69#define AR_name_offset 0 70#define AR_name_size 16 71#define AR_date_offset 16 72#define AR_date_size 12 73#define AR_uid_offset 28 74#define AR_uid_size 6 75#define AR_gid_offset 34 76#define AR_gid_size 6 77#define AR_mode_offset 40 78#define AR_mode_size 8 79#define AR_size_offset 48 80#define AR_size_size 10 81#define AR_fmag_offset 58 82#define AR_fmag_size 2 83 84static int archive_read_format_ar_bid(struct archive_read *a, int); 85static int archive_read_format_ar_cleanup(struct archive_read *a); 86static int archive_read_format_ar_read_data(struct archive_read *a, 87 const void **buff, size_t *size, int64_t *offset); 88static int archive_read_format_ar_skip(struct archive_read *a); 89static int archive_read_format_ar_read_header(struct archive_read *a, 90 struct archive_entry *e); 91static uint64_t ar_atol8(const char *p, unsigned char_cnt); 92static uint64_t ar_atol10(const char *p, unsigned char_cnt); 93static int ar_parse_gnu_filename_table(struct archive_read *a); 94static int ar_parse_common_header(struct ar *ar, struct archive_entry *, 95 const char *h); 96 97int 98archive_read_support_format_ar(struct archive *_a) 99{ 100 struct archive_read *a = (struct archive_read *)_a; 101 struct ar *ar; 102 int r; 103 104 archive_check_magic(_a, ARCHIVE_READ_MAGIC, 105 ARCHIVE_STATE_NEW, "archive_read_support_format_ar"); 106 107 ar = (struct ar *)calloc(1, sizeof(*ar)); 108 if (ar == NULL) { 109 archive_set_error(&a->archive, ENOMEM, 110 "Can't allocate ar data"); 111 return (ARCHIVE_FATAL); 112 } 113 ar->strtab = NULL; 114 115 r = __archive_read_register_format(a, 116 ar, 117 "ar", 118 archive_read_format_ar_bid, 119 NULL, 120 archive_read_format_ar_read_header, 121 archive_read_format_ar_read_data, 122 archive_read_format_ar_skip, 123 NULL, 124 archive_read_format_ar_cleanup, 125 NULL, 126 NULL); 127 128 if (r != ARCHIVE_OK) { 129 free(ar); 130 return (r); 131 } 132 return (ARCHIVE_OK); 133} 134 135static int 136archive_read_format_ar_cleanup(struct archive_read *a) 137{ 138 struct ar *ar; 139 140 ar = (struct ar *)(a->format->data); 141 if (ar->strtab) 142 free(ar->strtab); 143 free(ar); 144 (a->format->data) = NULL; 145 return (ARCHIVE_OK); 146} 147 148static int 149archive_read_format_ar_bid(struct archive_read *a, int best_bid) 150{ 151 const void *h; 152 153 (void)best_bid; /* UNUSED */ 154 155 /* 156 * Verify the 8-byte file signature. 157 * TODO: Do we need to check more than this? 158 */ 159 if ((h = __archive_read_ahead(a, 8, NULL)) == NULL) 160 return (-1); 161 if (memcmp(h, "!<arch>\n", 8) == 0) { 162 return (64); 163 } 164 return (-1); 165} 166 167static int 168_ar_read_header(struct archive_read *a, struct archive_entry *entry, 169 struct ar *ar, const char *h, size_t *unconsumed) 170{ 171 char filename[AR_name_size + 1]; 172 uint64_t number; /* Used to hold parsed numbers before validation. */ 173 size_t bsd_name_length, entry_size; 174 char *p, *st; 175 const void *b; 176 int r; 177 178 /* Verify the magic signature on the file header. */ 179 if (strncmp(h + AR_fmag_offset, "`\n", 2) != 0) { 180 archive_set_error(&a->archive, EINVAL, 181 "Incorrect file header signature"); 182 return (ARCHIVE_FATAL); 183 } 184 185 /* Copy filename into work buffer. */ 186 strncpy(filename, h + AR_name_offset, AR_name_size); 187 filename[AR_name_size] = '\0'; 188 189 /* 190 * Guess the format variant based on the filename. 191 */ 192 if (a->archive.archive_format == ARCHIVE_FORMAT_AR) { 193 /* We don't already know the variant, so let's guess. */ 194 /* 195 * Biggest clue is presence of '/': GNU starts special 196 * filenames with '/', appends '/' as terminator to 197 * non-special names, so anything with '/' should be 198 * GNU except for BSD long filenames. 199 */ 200 if (strncmp(filename, "#1/", 3) == 0) 201 a->archive.archive_format = ARCHIVE_FORMAT_AR_BSD; 202 else if (strchr(filename, '/') != NULL) 203 a->archive.archive_format = ARCHIVE_FORMAT_AR_GNU; 204 else if (strncmp(filename, "__.SYMDEF", 9) == 0) 205 a->archive.archive_format = ARCHIVE_FORMAT_AR_BSD; 206 /* 207 * XXX Do GNU/SVR4 'ar' programs ever omit trailing '/' 208 * if name exactly fills 16-byte field? If so, we 209 * can't assume entries without '/' are BSD. XXX 210 */ 211 } 212 213 /* Update format name from the code. */ 214 if (a->archive.archive_format == ARCHIVE_FORMAT_AR_GNU) 215 a->archive.archive_format_name = "ar (GNU/SVR4)"; 216 else if (a->archive.archive_format == ARCHIVE_FORMAT_AR_BSD) 217 a->archive.archive_format_name = "ar (BSD)"; 218 else 219 a->archive.archive_format_name = "ar"; 220 221 /* 222 * Remove trailing spaces from the filename. GNU and BSD 223 * variants both pad filename area out with spaces. 224 * This will only be wrong if GNU/SVR4 'ar' implementations 225 * omit trailing '/' for 16-char filenames and we have 226 * a 16-char filename that ends in ' '. 227 */ 228 p = filename + AR_name_size - 1; 229 while (p >= filename && *p == ' ') { 230 *p = '\0'; 231 p--; 232 } 233 234 /* 235 * Remove trailing slash unless first character is '/'. 236 * (BSD entries never end in '/', so this will only trim 237 * GNU-format entries. GNU special entries start with '/' 238 * and are not terminated in '/', so we don't trim anything 239 * that starts with '/'.) 240 */ 241 if (filename[0] != '/' && p > filename && *p == '/') { 242 *p = '\0'; 243 } 244 245 if (p < filename) { 246 archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC, 247 "Found entry with empty filename"); 248 return (ARCHIVE_FATAL); 249 } 250 251 /* 252 * '//' is the GNU filename table. 253 * Later entries can refer to names in this table. 254 */ 255 if (strcmp(filename, "//") == 0) { 256 /* This must come before any call to _read_ahead. */ 257 ar_parse_common_header(ar, entry, h); 258 archive_entry_copy_pathname(entry, filename); 259 archive_entry_set_filetype(entry, AE_IFREG); 260 /* Get the size of the filename table. */ 261 number = ar_atol10(h + AR_size_offset, AR_size_size); 262 if (number > SIZE_MAX || number > 1024 * 1024 * 1024) { 263 archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC, 264 "Filename table too large"); 265 return (ARCHIVE_FATAL); 266 } 267 entry_size = (size_t)number; 268 if (entry_size == 0) { 269 archive_set_error(&a->archive, EINVAL, 270 "Invalid string table"); 271 return (ARCHIVE_FATAL); 272 } 273 if (ar->strtab != NULL) { 274 archive_set_error(&a->archive, EINVAL, 275 "More than one string tables exist"); 276 return (ARCHIVE_FATAL); 277 } 278 279 /* Read the filename table into memory. */ 280 st = malloc(entry_size); 281 if (st == NULL) { 282 archive_set_error(&a->archive, ENOMEM, 283 "Can't allocate filename table buffer"); 284 return (ARCHIVE_FATAL); 285 } 286 ar->strtab = st; 287 ar->strtab_size = entry_size; 288 289 if (*unconsumed) { 290 __archive_read_consume(a, *unconsumed); 291 *unconsumed = 0; 292 } 293 294 if ((b = __archive_read_ahead(a, entry_size, NULL)) == NULL) 295 return (ARCHIVE_FATAL); 296 memcpy(st, b, entry_size); 297 __archive_read_consume(a, entry_size); 298 /* All contents are consumed. */ 299 ar->entry_bytes_remaining = 0; 300 archive_entry_set_size(entry, ar->entry_bytes_remaining); 301 302 /* Parse the filename table. */ 303 return (ar_parse_gnu_filename_table(a)); 304 } 305 306 /* 307 * GNU variant handles long filenames by storing /<number> 308 * to indicate a name stored in the filename table. 309 * XXX TODO: Verify that it's all digits... Don't be fooled 310 * by "/9xyz" XXX 311 */ 312 if (filename[0] == '/' && filename[1] >= '0' && filename[1] <= '9') { 313 number = ar_atol10(h + AR_name_offset + 1, AR_name_size - 1); 314 /* 315 * If we can't look up the real name, warn and return 316 * the entry with the wrong name. 317 */ 318 if (ar->strtab == NULL || number >= ar->strtab_size) { 319 archive_set_error(&a->archive, EINVAL, 320 "Can't find long filename for GNU/SVR4 archive entry"); 321 archive_entry_copy_pathname(entry, filename); 322 /* Parse the time, owner, mode, size fields. */ 323 ar_parse_common_header(ar, entry, h); 324 return (ARCHIVE_FATAL); 325 } 326 327 archive_entry_copy_pathname(entry, &ar->strtab[(size_t)number]); 328 /* Parse the time, owner, mode, size fields. */ 329 return (ar_parse_common_header(ar, entry, h)); 330 } 331 332 /* 333 * BSD handles long filenames by storing "#1/" followed by the 334 * length of filename as a decimal number, then prepends the 335 * the filename to the file contents. 336 */ 337 if (strncmp(filename, "#1/", 3) == 0) { 338 /* Parse the time, owner, mode, size fields. */ 339 /* This must occur before _read_ahead is called again. */ 340 ar_parse_common_header(ar, entry, h); 341 342 /* Parse the size of the name, adjust the file size. */ 343 number = ar_atol10(h + AR_name_offset + 3, AR_name_size - 3); 344 /* Sanity check the filename length: 345 * = Must be <= SIZE_MAX - 1 346 * = Must be <= 1MB 347 * = Cannot be bigger than the entire entry 348 */ 349 if (number > SIZE_MAX - 1 350 || number > 1024 * 1024 351 || (int64_t)number > ar->entry_bytes_remaining) { 352 archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC, 353 "Bad input file size"); 354 return (ARCHIVE_FATAL); 355 } 356 bsd_name_length = (size_t)number; 357 ar->entry_bytes_remaining -= bsd_name_length; 358 /* Adjust file size reported to client. */ 359 archive_entry_set_size(entry, ar->entry_bytes_remaining); 360 361 if (*unconsumed) { 362 __archive_read_consume(a, *unconsumed); 363 *unconsumed = 0; 364 } 365 366 /* Read the long name into memory. */ 367 if ((b = __archive_read_ahead(a, bsd_name_length, NULL)) == NULL) { 368 archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC, 369 "Truncated input file"); 370 return (ARCHIVE_FATAL); 371 } 372 /* Store it in the entry. */ 373 p = (char *)malloc(bsd_name_length + 1); 374 if (p == NULL) { 375 archive_set_error(&a->archive, ENOMEM, 376 "Can't allocate fname buffer"); 377 return (ARCHIVE_FATAL); 378 } 379 strncpy(p, b, bsd_name_length); 380 p[bsd_name_length] = '\0'; 381 382 __archive_read_consume(a, bsd_name_length); 383 384 archive_entry_copy_pathname(entry, p); 385 free(p); 386 return (ARCHIVE_OK); 387 } 388 389 /* 390 * "/" is the SVR4/GNU archive symbol table. 391 */ 392 if (strcmp(filename, "/") == 0) { 393 archive_entry_copy_pathname(entry, "/"); 394 /* Parse the time, owner, mode, size fields. */ 395 r = ar_parse_common_header(ar, entry, h); 396 /* Force the file type to a regular file. */ 397 archive_entry_set_filetype(entry, AE_IFREG); 398 return (r); 399 } 400 401 /* 402 * "__.SYMDEF" is a BSD archive symbol table. 403 */ 404 if (strcmp(filename, "__.SYMDEF") == 0) { 405 archive_entry_copy_pathname(entry, filename); 406 /* Parse the time, owner, mode, size fields. */ 407 return (ar_parse_common_header(ar, entry, h)); 408 } 409 410 /* 411 * Otherwise, this is a standard entry. The filename 412 * has already been trimmed as much as possible, based 413 * on our current knowledge of the format. 414 */ 415 archive_entry_copy_pathname(entry, filename); 416 return (ar_parse_common_header(ar, entry, h)); 417} 418 419static int 420archive_read_format_ar_read_header(struct archive_read *a, 421 struct archive_entry *entry) 422{ 423 struct ar *ar = (struct ar*)(a->format->data); 424 size_t unconsumed; 425 const void *header_data; 426 int ret; 427 428 if (!ar->read_global_header) { 429 /* 430 * We are now at the beginning of the archive, 431 * so we need first consume the ar global header. 432 */ 433 __archive_read_consume(a, 8); 434 ar->read_global_header = 1; 435 /* Set a default format code for now. */ 436 a->archive.archive_format = ARCHIVE_FORMAT_AR; 437 } 438 439 /* Read the header for the next file entry. */ 440 if ((header_data = __archive_read_ahead(a, 60, NULL)) == NULL) 441 /* Broken header. */ 442 return (ARCHIVE_EOF); 443 444 unconsumed = 60; 445 446 ret = _ar_read_header(a, entry, ar, (const char *)header_data, &unconsumed); 447 448 if (unconsumed) 449 __archive_read_consume(a, unconsumed); 450 451 return ret; 452} 453 454 455static int 456ar_parse_common_header(struct ar *ar, struct archive_entry *entry, 457 const char *h) 458{ 459 uint64_t n; 460 461 /* Copy remaining header */ 462 archive_entry_set_mtime(entry, 463 (time_t)ar_atol10(h + AR_date_offset, AR_date_size), 0L); 464 archive_entry_set_uid(entry, 465 (uid_t)ar_atol10(h + AR_uid_offset, AR_uid_size)); 466 archive_entry_set_gid(entry, 467 (gid_t)ar_atol10(h + AR_gid_offset, AR_gid_size)); 468 archive_entry_set_mode(entry, 469 (mode_t)ar_atol8(h + AR_mode_offset, AR_mode_size)); 470 n = ar_atol10(h + AR_size_offset, AR_size_size); 471 472 ar->entry_offset = 0; 473 ar->entry_padding = n % 2; 474 archive_entry_set_size(entry, n); 475 ar->entry_bytes_remaining = n; 476 return (ARCHIVE_OK); 477} 478 479static int 480archive_read_format_ar_read_data(struct archive_read *a, 481 const void **buff, size_t *size, int64_t *offset) 482{ 483 ssize_t bytes_read; 484 struct ar *ar; 485 486 ar = (struct ar *)(a->format->data); 487 488 if (ar->entry_bytes_unconsumed) { 489 __archive_read_consume(a, ar->entry_bytes_unconsumed); 490 ar->entry_bytes_unconsumed = 0; 491 } 492 493 if (ar->entry_bytes_remaining > 0) { 494 *buff = __archive_read_ahead(a, 1, &bytes_read); 495 if (bytes_read == 0) { 496 archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC, 497 "Truncated ar archive"); 498 return (ARCHIVE_FATAL); 499 } 500 if (bytes_read < 0) 501 return (ARCHIVE_FATAL); 502 if (bytes_read > ar->entry_bytes_remaining) 503 bytes_read = (ssize_t)ar->entry_bytes_remaining; 504 *size = bytes_read; 505 ar->entry_bytes_unconsumed = bytes_read; 506 *offset = ar->entry_offset; 507 ar->entry_offset += bytes_read; 508 ar->entry_bytes_remaining -= bytes_read; 509 return (ARCHIVE_OK); 510 } else { 511 int64_t skipped = __archive_read_consume(a, ar->entry_padding); 512 if (skipped >= 0) { 513 ar->entry_padding -= skipped; 514 } 515 if (ar->entry_padding) { 516 if (skipped >= 0) { 517 archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC, 518 "Truncated ar archive- failed consuming padding"); 519 } 520 return (ARCHIVE_FATAL); 521 } 522 *buff = NULL; 523 *size = 0; 524 *offset = ar->entry_offset; 525 return (ARCHIVE_EOF); 526 } 527} 528 529static int 530archive_read_format_ar_skip(struct archive_read *a) 531{ 532 int64_t bytes_skipped; 533 struct ar* ar; 534 535 ar = (struct ar *)(a->format->data); 536 537 bytes_skipped = __archive_read_consume(a, 538 ar->entry_bytes_remaining + ar->entry_padding 539 + ar->entry_bytes_unconsumed); 540 if (bytes_skipped < 0) 541 return (ARCHIVE_FATAL); 542 543 ar->entry_bytes_remaining = 0; 544 ar->entry_bytes_unconsumed = 0; 545 ar->entry_padding = 0; 546 547 return (ARCHIVE_OK); 548} 549 550static int 551ar_parse_gnu_filename_table(struct archive_read *a) 552{ 553 struct ar *ar; 554 char *p; 555 size_t size; 556 557 ar = (struct ar*)(a->format->data); 558 size = ar->strtab_size; 559 560 for (p = ar->strtab; p < ar->strtab + size - 1; ++p) { 561 if (*p == '/') { 562 *p++ = '\0'; 563 if (*p != '\n') 564 goto bad_string_table; 565 *p = '\0'; 566 } 567 } 568 /* 569 * GNU ar always pads the table to an even size. 570 * The pad character is either '\n' or '`'. 571 */ 572 if (p != ar->strtab + size && *p != '\n' && *p != '`') 573 goto bad_string_table; 574 575 /* Enforce zero termination. */ 576 ar->strtab[size - 1] = '\0'; 577 578 return (ARCHIVE_OK); 579 580bad_string_table: 581 archive_set_error(&a->archive, EINVAL, 582 "Invalid string table"); 583 free(ar->strtab); 584 ar->strtab = NULL; 585 return (ARCHIVE_FATAL); 586} 587 588static uint64_t 589ar_atol8(const char *p, unsigned char_cnt) 590{ 591 uint64_t l, limit, last_digit_limit; 592 unsigned int digit, base; 593 594 base = 8; 595 limit = UINT64_MAX / base; 596 last_digit_limit = UINT64_MAX % base; 597 598 while ((*p == ' ' || *p == '\t') && char_cnt-- > 0) 599 p++; 600 601 l = 0; 602 digit = *p - '0'; 603 while (*p >= '0' && digit < base && char_cnt-- > 0) { 604 if (l>limit || (l == limit && digit > last_digit_limit)) { 605 l = UINT64_MAX; /* Truncate on overflow. */ 606 break; 607 } 608 l = (l * base) + digit; 609 digit = *++p - '0'; 610 } 611 return (l); 612} 613 614static uint64_t 615ar_atol10(const char *p, unsigned char_cnt) 616{ 617 uint64_t l, limit, last_digit_limit; 618 unsigned int base, digit; 619 620 base = 10; 621 limit = UINT64_MAX / base; 622 last_digit_limit = UINT64_MAX % base; 623 624 while ((*p == ' ' || *p == '\t') && char_cnt-- > 0) 625 p++; 626 l = 0; 627 digit = *p - '0'; 628 while (*p >= '0' && digit < base && char_cnt-- > 0) { 629 if (l > limit || (l == limit && digit > last_digit_limit)) { 630 l = UINT64_MAX; /* Truncate on overflow. */ 631 break; 632 } 633 l = (l * base) + digit; 634 digit = *++p - '0'; 635 } 636 return (l); 637} 638