1 /*- 2 * Copyright (c) 2003-2007 Tim Kientzle 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR 15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 17 * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT, 18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 24 */ 25 26 #include "bsdtar_platform.h" 27 __FBSDID("$FreeBSD: src/usr.bin/tar/util.c,v 1.23 2008/12/15 06:00:25 kientzle Exp $"); 28 29 #ifdef HAVE_SYS_STAT_H 30 #include <sys/stat.h> 31 #endif 32 #ifdef HAVE_SYS_TYPES_H 33 #include <sys/types.h> /* Linux doesn't define mode_t, etc. in sys/stat.h. */ 34 #endif 35 #include <ctype.h> 36 #ifdef HAVE_ERRNO_H 37 #include <errno.h> 38 #endif 39 #ifdef HAVE_IO_H 40 #include <io.h> 41 #endif 42 #ifdef HAVE_STDARG_H 43 #include <stdarg.h> 44 #endif 45 #ifdef HAVE_STDINT_H 46 #include <stdint.h> 47 #endif 48 #include <stdio.h> 49 #ifdef HAVE_STDLIB_H 50 #include <stdlib.h> 51 #endif 52 #ifdef HAVE_STRING_H 53 #include <string.h> 54 #endif 55 #ifdef HAVE_WCTYPE_H 56 #include <wctype.h> 57 #else 58 /* If we don't have wctype, we need to hack up some version of iswprint(). */ 59 #define iswprint isprint 60 #endif 61 62 #include "bsdtar.h" 63 #include "err.h" 64 65 static size_t bsdtar_expand_char(char *, size_t, char); 66 static const char *strip_components(const char *path, int elements); 67 68 #if defined(_WIN32) && !defined(__CYGWIN__) 69 #define read _read 70 #endif 71 72 /* TODO: Hack up a version of mbtowc for platforms with no wide 73 * character support at all. I think the following might suffice, 74 * but it needs careful testing. 75 * #if !HAVE_MBTOWC 76 * #define mbtowc(wcp, p, n) ((*wcp = *p), 1) 77 * #endif 78 */ 79 80 /* 81 * Print a string, taking care with any non-printable characters. 82 * 83 * Note that we use a stack-allocated buffer to receive the formatted 84 * string if we can. This is partly performance (avoiding a call to 85 * malloc()), partly out of expedience (we have to call vsnprintf() 86 * before malloc() anyway to find out how big a buffer we need; we may 87 * as well point that first call at a small local buffer in case it 88 * works), but mostly for safety (so we can use this to print messages 89 * about out-of-memory conditions). 90 */ 91 92 void 93 safe_fprintf(FILE *f, const char *fmt, ...) 94 { 95 char fmtbuff_stack[256]; /* Place to format the printf() string. */ 96 char outbuff[256]; /* Buffer for outgoing characters. */ 97 char *fmtbuff_heap; /* If fmtbuff_stack is too small, we use malloc */ 98 char *fmtbuff; /* Pointer to fmtbuff_stack or fmtbuff_heap. */ 99 int fmtbuff_length; 100 int length, n; 101 va_list ap; 102 const char *p; 103 unsigned i; 104 wchar_t wc; 105 char try_wc; 106 107 /* Use a stack-allocated buffer if we can, for speed and safety. */ 108 fmtbuff_heap = NULL; 109 fmtbuff_length = sizeof(fmtbuff_stack); 110 fmtbuff = fmtbuff_stack; 111 112 /* Try formatting into the stack buffer. */ 113 va_start(ap, fmt); 114 length = vsnprintf(fmtbuff, fmtbuff_length, fmt, ap); 115 va_end(ap); 116 117 /* If the result was too large, allocate a buffer on the heap. */ 118 if (length >= fmtbuff_length) { 119 fmtbuff_length = length+1; 120 fmtbuff_heap = malloc(fmtbuff_length); 121 122 /* Reformat the result into the heap buffer if we can. */ 123 if (fmtbuff_heap != NULL) { 124 fmtbuff = fmtbuff_heap; 125 va_start(ap, fmt); 126 length = vsnprintf(fmtbuff, fmtbuff_length, fmt, ap); 127 va_end(ap); 128 } else { 129 /* Leave fmtbuff pointing to the truncated 130 * string in fmtbuff_stack. */ 131 length = sizeof(fmtbuff_stack) - 1; 132 } 133 } 134 135 /* Note: mbrtowc() has a cleaner API, but mbtowc() seems a bit 136 * more portable, so we use that here instead. */ 137 n = mbtowc(NULL, NULL, 1); /* Reset the shift state. */ 138 139 /* Write data, expanding unprintable characters. */ 140 p = fmtbuff; 141 i = 0; 142 try_wc = 1; 143 while (*p != '\0') { 144 145 /* Convert to wide char, test if the wide 146 * char is printable in the current locale. */ 147 if (try_wc && (n = mbtowc(&wc, p, length)) != -1) { 148 length -= n; 149 if (iswprint(wc) && wc != L'\\') { 150 /* Printable, copy the bytes through. */ 151 while (n-- > 0) 152 outbuff[i++] = *p++; 153 } else { 154 /* Not printable, format the bytes. */ 155 while (n-- > 0) 156 i += (unsigned)bsdtar_expand_char( 157 outbuff, i, *p++); 158 } 159 } else { 160 /* After any conversion failure, don't bother 161 * trying to convert the rest. */ 162 i += (unsigned)bsdtar_expand_char(outbuff, i, *p++); 163 try_wc = 0; 164 } 165 166 /* If our output buffer is full, dump it and keep going. */ 167 if (i > (sizeof(outbuff) - 20)) { 168 outbuff[i] = '\0'; 169 fprintf(f, "%s", outbuff); 170 i = 0; 171 } 172 } 173 outbuff[i] = '\0'; 174 fprintf(f, "%s", outbuff); 175 176 /* If we allocated a heap-based formatting buffer, free it now. */ 177 if (fmtbuff_heap != NULL) 178 free(fmtbuff_heap); 179 } 180 181 /* 182 * Render an arbitrary sequence of bytes into printable ASCII characters. 183 */ 184 static size_t 185 bsdtar_expand_char(char *buff, size_t offset, char c) 186 { 187 size_t i = offset; 188 189 if (isprint((unsigned char)c) && c != '\\') 190 buff[i++] = c; 191 else { 192 buff[i++] = '\\'; 193 switch (c) { 194 case '\a': buff[i++] = 'a'; break; 195 case '\b': buff[i++] = 'b'; break; 196 case '\f': buff[i++] = 'f'; break; 197 case '\n': buff[i++] = 'n'; break; 198 #if '\r' != '\n' 199 /* On some platforms, \n and \r are the same. */ 200 case '\r': buff[i++] = 'r'; break; 201 #endif 202 case '\t': buff[i++] = 't'; break; 203 case '\v': buff[i++] = 'v'; break; 204 case '\\': buff[i++] = '\\'; break; 205 default: 206 sprintf(buff + i, "%03o", 0xFF & (int)c); 207 i += 3; 208 } 209 } 210 211 return (i - offset); 212 } 213 214 int 215 yes(const char *fmt, ...) 216 { 217 char buff[32]; 218 char *p; 219 ssize_t l; 220 221 va_list ap; 222 va_start(ap, fmt); 223 vfprintf(stderr, fmt, ap); 224 va_end(ap); 225 fprintf(stderr, " (y/N)? "); 226 fflush(stderr); 227 228 l = read(2, buff, sizeof(buff) - 1); 229 if (l <= 0) 230 return (0); 231 buff[l] = 0; 232 233 for (p = buff; *p != '\0'; p++) { 234 if (isspace((unsigned char)*p)) 235 continue; 236 switch(*p) { 237 case 'y': case 'Y': 238 return (1); 239 case 'n': case 'N': 240 return (0); 241 default: 242 return (0); 243 } 244 } 245 246 return (0); 247 } 248 249 /*- 250 * The logic here for -C <dir> attempts to avoid 251 * chdir() as long as possible. For example: 252 * "-C /foo -C /bar file" needs chdir("/bar") but not chdir("/foo") 253 * "-C /foo -C bar file" needs chdir("/foo/bar") 254 * "-C /foo -C bar /file1" does not need chdir() 255 * "-C /foo -C bar /file1 file2" needs chdir("/foo/bar") before file2 256 * 257 * The only correct way to handle this is to record a "pending" chdir 258 * request and combine multiple requests intelligently until we 259 * need to process a non-absolute file. set_chdir() adds the new dir 260 * to the pending list; do_chdir() actually executes any pending chdir. 261 * 262 * This way, programs that build tar command lines don't have to worry 263 * about -C with non-existent directories; such requests will only 264 * fail if the directory must be accessed. 265 * 266 * TODO: Make this handle Windows paths correctly. 267 */ 268 void 269 set_chdir(struct bsdtar *bsdtar, const char *newdir) 270 { 271 if (newdir[0] == '/') { 272 /* The -C /foo -C /bar case; dump first one. */ 273 free(bsdtar->pending_chdir); 274 bsdtar->pending_chdir = NULL; 275 } 276 if (bsdtar->pending_chdir == NULL) 277 /* Easy case: no previously-saved dir. */ 278 bsdtar->pending_chdir = strdup(newdir); 279 else { 280 /* The -C /foo -C bar case; concatenate */ 281 char *old_pending = bsdtar->pending_chdir; 282 size_t old_len = strlen(old_pending); 283 bsdtar->pending_chdir = malloc(old_len + strlen(newdir) + 2); 284 if (old_pending[old_len - 1] == '/') 285 old_pending[old_len - 1] = '\0'; 286 if (bsdtar->pending_chdir != NULL) 287 sprintf(bsdtar->pending_chdir, "%s/%s", 288 old_pending, newdir); 289 free(old_pending); 290 } 291 if (bsdtar->pending_chdir == NULL) 292 lafe_errc(1, errno, "No memory"); 293 } 294 295 void 296 do_chdir(struct bsdtar *bsdtar) 297 { 298 if (bsdtar->pending_chdir == NULL) 299 return; 300 301 if (chdir(bsdtar->pending_chdir) != 0) { 302 lafe_errc(1, 0, "could not chdir to '%s'\n", 303 bsdtar->pending_chdir); 304 } 305 free(bsdtar->pending_chdir); 306 bsdtar->pending_chdir = NULL; 307 } 308 309 static const char * 310 strip_components(const char *p, int elements) 311 { 312 /* Skip as many elements as necessary. */ 313 while (elements > 0) { 314 switch (*p++) { 315 case '/': 316 #if defined(_WIN32) && !defined(__CYGWIN__) 317 case '\\': /* Support \ path sep on Windows ONLY. */ 318 #endif 319 elements--; 320 break; 321 case '\0': 322 /* Path is too short, skip it. */ 323 return (NULL); 324 } 325 } 326 327 /* Skip any / characters. This handles short paths that have 328 * additional / termination. This also handles the case where 329 * the logic above stops in the middle of a duplicate // 330 * sequence (which would otherwise get converted to an 331 * absolute path). */ 332 for (;;) { 333 switch (*p) { 334 case '/': 335 #if defined(_WIN32) && !defined(__CYGWIN__) 336 case '\\': /* Support \ path sep on Windows ONLY. */ 337 #endif 338 ++p; 339 break; 340 case '\0': 341 return (NULL); 342 default: 343 return (p); 344 } 345 } 346 } 347 348 /* 349 * Handle --strip-components and any future path-rewriting options. 350 * Returns non-zero if the pathname should not be extracted. 351 * 352 * TODO: Support pax-style regex path rewrites. 353 */ 354 int 355 edit_pathname(struct bsdtar *bsdtar, struct archive_entry *entry) 356 { 357 const char *name = archive_entry_pathname(entry); 358 #if HAVE_REGEX_H 359 char *subst_name; 360 int r; 361 #endif 362 363 #if HAVE_REGEX_H 364 r = apply_substitution(bsdtar, name, &subst_name, 0); 365 if (r == -1) { 366 lafe_warnc(0, "Invalid substitution, skipping entry"); 367 return 1; 368 } 369 if (r == 1) { 370 archive_entry_copy_pathname(entry, subst_name); 371 if (*subst_name == '\0') { 372 free(subst_name); 373 return -1; 374 } else 375 free(subst_name); 376 name = archive_entry_pathname(entry); 377 } 378 379 if (archive_entry_hardlink(entry)) { 380 r = apply_substitution(bsdtar, archive_entry_hardlink(entry), &subst_name, 1); 381 if (r == -1) { 382 lafe_warnc(0, "Invalid substitution, skipping entry"); 383 return 1; 384 } 385 if (r == 1) { 386 archive_entry_copy_hardlink(entry, subst_name); 387 free(subst_name); 388 } 389 } 390 if (archive_entry_symlink(entry) != NULL) { 391 r = apply_substitution(bsdtar, archive_entry_symlink(entry), &subst_name, 1); 392 if (r == -1) { 393 lafe_warnc(0, "Invalid substitution, skipping entry"); 394 return 1; 395 } 396 if (r == 1) { 397 archive_entry_copy_symlink(entry, subst_name); 398 free(subst_name); 399 } 400 } 401 #endif 402 403 /* Strip leading dir names as per --strip-components option. */ 404 if (bsdtar->strip_components > 0) { 405 const char *linkname = archive_entry_hardlink(entry); 406 407 name = strip_components(name, bsdtar->strip_components); 408 if (name == NULL) 409 return (1); 410 411 if (linkname != NULL) { 412 linkname = strip_components(linkname, 413 bsdtar->strip_components); 414 if (linkname == NULL) 415 return (1); 416 archive_entry_copy_hardlink(entry, linkname); 417 } 418 } 419 420 /* By default, don't write or restore absolute pathnames. */ 421 if (!bsdtar->option_absolute_paths) { 422 const char *rp, *p = name; 423 int slashonly = 1; 424 425 /* Remove leading "//./" or "//?/" or "//?/UNC/" 426 * (absolute path prefixes used by Windows API) */ 427 if ((p[0] == '/' || p[0] == '\\') && 428 (p[1] == '/' || p[1] == '\\') && 429 (p[2] == '.' || p[2] == '?') && 430 (p[3] == '/' || p[3] == '\\')) 431 { 432 if (p[2] == '?' && 433 (p[4] == 'U' || p[4] == 'u') && 434 (p[5] == 'N' || p[5] == 'n') && 435 (p[6] == 'C' || p[6] == 'c') && 436 (p[7] == '/' || p[7] == '\\')) 437 p += 8; 438 else 439 p += 4; 440 slashonly = 0; 441 } 442 do { 443 rp = p; 444 /* Remove leading drive letter from archives created 445 * on Windows. */ 446 if (((p[0] >= 'a' && p[0] <= 'z') || 447 (p[0] >= 'A' && p[0] <= 'Z')) && 448 p[1] == ':') { 449 p += 2; 450 slashonly = 0; 451 } 452 /* Remove leading "/../", "//", etc. */ 453 while (p[0] == '/' || p[0] == '\\') { 454 if (p[1] == '.' && p[2] == '.' && 455 (p[3] == '/' || p[3] == '\\')) { 456 p += 3; /* Remove "/..", leave "/" 457 * for next pass. */ 458 slashonly = 0; 459 } else 460 p += 1; /* Remove "/". */ 461 } 462 } while (rp != p); 463 464 if (p != name && !bsdtar->warned_lead_slash) { 465 /* Generate a warning the first time this happens. */ 466 if (slashonly) 467 lafe_warnc(0, 468 "Removing leading '%c' from member names", 469 name[0]); 470 else 471 lafe_warnc(0, 472 "Removing leading drive letter from " 473 "member names"); 474 bsdtar->warned_lead_slash = 1; 475 } 476 477 /* Special case: Stripping everything yields ".". */ 478 if (*p == '\0') 479 name = "."; 480 else 481 name = p; 482 } else { 483 /* Strip redundant leading '/' characters. */ 484 while (name[0] == '/' && name[1] == '/') 485 name++; 486 } 487 488 /* Safely replace name in archive_entry. */ 489 if (name != archive_entry_pathname(entry)) { 490 char *q = strdup(name); 491 archive_entry_copy_pathname(entry, q); 492 free(q); 493 } 494 return (0); 495 } 496 497 /* 498 * It would be nice to just use printf() for formatting large numbers, 499 * but the compatibility problems are quite a headache. Hence the 500 * following simple utility function. 501 */ 502 const char * 503 tar_i64toa(int64_t n0) 504 { 505 static char buff[24]; 506 int64_t n = n0 < 0 ? -n0 : n0; 507 char *p = buff + sizeof(buff); 508 509 *--p = '\0'; 510 do { 511 *--p = '0' + (int)(n % 10); 512 n /= 10; 513 } while (n > 0); 514 if (n0 < 0) 515 *--p = '-'; 516 return p; 517 } 518 519 /* 520 * Like strcmp(), but try to be a little more aware of the fact that 521 * we're comparing two paths. Right now, it just handles leading 522 * "./" and trailing '/' specially, so that "a/b/" == "./a/b" 523 * 524 * TODO: Make this better, so that "./a//b/./c/" == "a/b/c" 525 * TODO: After this works, push it down into libarchive. 526 * TODO: Publish the path normalization routines in libarchive so 527 * that bsdtar can normalize paths and use fast strcmp() instead 528 * of this. 529 * 530 * Note: This is currently only used within write.c, so should 531 * not handle \ path separators. 532 */ 533 534 int 535 pathcmp(const char *a, const char *b) 536 { 537 /* Skip leading './' */ 538 if (a[0] == '.' && a[1] == '/' && a[2] != '\0') 539 a += 2; 540 if (b[0] == '.' && b[1] == '/' && b[2] != '\0') 541 b += 2; 542 /* Find the first difference, or return (0) if none. */ 543 while (*a == *b) { 544 if (*a == '\0') 545 return (0); 546 a++; 547 b++; 548 } 549 /* 550 * If one ends in '/' and the other one doesn't, 551 * they're the same. 552 */ 553 if (a[0] == '/' && a[1] == '\0' && b[0] == '\0') 554 return (0); 555 if (a[0] == '\0' && b[0] == '/' && b[1] == '\0') 556 return (0); 557 /* They're really different, return the correct sign. */ 558 return (*(const unsigned char *)a - *(const unsigned char *)b); 559 } 560