Dogcows Code - chaz/tar/blob - src/xheader.c

   1 /* POSIX extended headers for tar.
   2
   3    Copyright (C) 2003, 2004 Free Software Foundation, Inc.
   4
   5    This program is free software; you can redistribute it and/or modify it
   6    under the terms of the GNU General Public License as published by the
   7    Free Software Foundation; either version 2, or (at your option) any later
   8    version.
   9
  10    This program is distributed in the hope that it will be useful, but
  11    WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General
  13    Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License along
  16    with this program; if not, write to the Free Software Foundation, Inc.,
  17    59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  18
  19 #include "system.h"
  20
  21 #include <fnmatch.h>
  22 #include <hash.h>
  23 #include <quotearg.h>
  24 #include <stpcpy.h>
  25 #include <xstrtol.h>
  26
  27 #include "common.h"
  28
  29 #define obstack_chunk_alloc xmalloc
  30 #define obstack_chunk_free free
  31 #include <obstack.h>
  32
  33 #include <fnmatch.h>
  34
  35 static bool xheader_protected_pattern_p (char const *pattern);
  36 static bool xheader_protected_keyword_p (char const *keyword);
  37 static void xheader_set_single_keyword (char *) __attribute__ ((noreturn));
  38
  39 /* Used by xheader_finish() */
  40 static void code_string (char const *string, char const *keyword,
  41                          struct xheader *xhdr);
  42 static void extended_header_init (void);
  43
  44 /* Number of global headers written so far. */
  45 static size_t global_header_count;
  46 /* FIXME: Possibly it should be reset after changing the volume.
  47    POSIX %n specification says that it is expanded to the sequence
  48    number of current global header in *the* archive. However, for
  49    multi-volume archives this will yield duplicate header names
  50    in different volumes, which I'd like to avoid. The best way
  51    to solve this would be to use per-archive header count as required
  52    by POSIX *and* set globexthdr.name to, say,
  53    $TMPDIR/GlobalHead.%p.$NUMVOLUME.%n.
  54
  55    However it should wait until buffer.c is finally rewritten */
  56
  57 \f
  58 /* Keyword options */
  59
  60 struct keyword_list
  61 {
  62   struct keyword_list *next;
  63   char *pattern;
  64   char *value;
  65 };
  66
  67
  68 /* List of keyword patterns set by delete= option */
  69 static struct keyword_list *keyword_pattern_list;
  70
  71 /* List of keyword/value pairs set by `keyword=value' option */
  72 static struct keyword_list *keyword_global_override_list;
  73
  74 /* List of keyword/value pairs set by `keyword:=value' option */
  75 static struct keyword_list *keyword_override_list;
  76
  77 /* List of keyword/value pairs decoded from the last 'g' type header */
  78 static struct keyword_list *global_header_override_list;
  79
  80 /* Template for the name field of an 'x' type header */
  81 static char *exthdr_name;
  82
  83 /* Template for the name field of a 'g' type header */
  84 static char *globexthdr_name;
  85
  86 static bool
  87 xheader_keyword_deleted_p (const char *kw)
  88 {
  89   struct keyword_list *kp;
  90
  91   for (kp = keyword_pattern_list; kp; kp = kp->next)
  92     if (fnmatch (kp->pattern, kw, 0) == 0)
  93       return true;
  94   return false;
  95 }
  96
  97 static bool
  98 xheader_keyword_override_p (const char *keyword)
  99 {
 100   struct keyword_list *kp;
 101
 102   for (kp = keyword_override_list; kp; kp = kp->next)
 103     if (strcmp (kp->pattern, keyword) == 0)
 104       return true;
 105   return false;
 106 }
 107
 108 static void
 109 xheader_list_append (struct keyword_list **root, char const *kw,
 110                      char const *value)
 111 {
 112   struct keyword_list *kp = xmalloc (sizeof *kp);
 113   kp->pattern = xstrdup (kw);
 114   kp->value = value ? xstrdup (value) : NULL;
 115   kp->next = *root;
 116   *root = kp;
 117 }
 118
 119 static void
 120 xheader_list_destroy (struct keyword_list **root)
 121 {
 122   if (root)
 123     {
 124       struct keyword_list *kw = *root;
 125       while (kw)
 126         {
 127           struct keyword_list *next = kw->next;
 128           free (kw->pattern);
 129           free (kw->value);
 130           free (kw);
 131           kw = next;
 132         }
 133       *root = NULL;
 134     }
 135 }
 136
 137 static void
 138 xheader_set_single_keyword (char *kw)
 139 {
 140   USAGE_ERROR ((0, 0, _("Keyword %s is unknown or not yet imlemented"), kw));
 141 }
 142
 143 static void
 144 xheader_set_keyword_equal (char *kw, char *eq)
 145 {
 146   bool global = true;
 147   char *p = eq;
 148
 149   if (eq[-1] == ':')
 150     {
 151       p--;
 152       global = false;
 153     }
 154
 155   while (p > kw && isspace (*p))
 156     p--;
 157
 158   *p = 0;
 159
 160   for (p = eq + 1; *p && isspace (*p); p++)
 161     ;
 162
 163   if (strcmp (kw, "delete") == 0)
 164     {
 165       if (xheader_protected_pattern_p (p))
 166         USAGE_ERROR ((0, 0, _("Pattern %s cannot be used"), p));
 167       xheader_list_append (&keyword_pattern_list, p, NULL);
 168     }
 169   else if (strcmp (kw, "exthdr.name") == 0)
 170     assign_string (&exthdr_name, p);
 171   else if (strcmp (kw, "globexthdr.name") == 0)
 172     assign_string (&globexthdr_name, p);
 173   else
 174     {
 175       if (xheader_protected_keyword_p (kw))
 176         USAGE_ERROR ((0, 0, _("Keyword %s cannot be overridden"), kw));
 177       if (global)
 178         xheader_list_append (&keyword_global_override_list, kw, p);
 179       else
 180         xheader_list_append (&keyword_override_list, kw, p);
 181     }
 182 }
 183
 184 void
 185 xheader_set_option (char *string)
 186 {
 187   char *token;
 188   for (token = strtok (string, ","); token; token = strtok (NULL, ","))
 189     {
 190       char *p = strchr (token, '=');
 191       if (!p)
 192         xheader_set_single_keyword (token);
 193       else
 194         xheader_set_keyword_equal (token, p);
 195     }
 196 }
 197
 198 static void
 199 to_decimal (uintmax_t value, char *where, size_t size)
 200 {
 201   size_t i = 0, j;
 202
 203   where[i++] = 0;
 204   do
 205     {
 206       where[i++] = '0' + value % 10;
 207       value /= 10;
 208     }
 209   while (i < size && value);
 210   for (j = 0, i--; j < i; j++, i--)
 211     {
 212       char c = where[j];
 213       where[j] = where[i];
 214       where[i] = c;
 215     }
 216 }
 217
 218 /*
 219     string Includes:          Replaced By:
 220      %d                       The directory name of the file,
 221                               equivalent to the result of the
 222                               dirname utility on the translated
 223                               file name.
 224      %f                       The filename of the file, equivalent
 225                               to the result of the basename
 226                               utility on the translated file name.
 227      %p                       The process ID of the pax process.
 228      %%                       A '%' character. */
 229
 230 static char *
 231 xheader_format_name (struct tar_stat_info *st, const char *fmt, bool allow_n)
 232 {
 233   char *buf;
 234   size_t len = strlen (fmt);
 235   char *q;
 236   const char *p;
 237   char *dir = NULL;
 238   char *base = NULL;
 239   char pidbuf[64];
 240   char nbuf[64];
 241
 242   for (p = fmt; *p && (p = strchr (p, '%')); )
 243     {
 244       switch (p[1])
 245         {
 246         case '%':
 247           len--;
 248           break;
 249
 250         case 'd':
 251           if (st)
 252             {
 253               dir = safer_name_suffix (dir_name (st->orig_file_name), false);
 254               len += strlen (dir) - 1;
 255             }
 256           break;
 257
 258         case 'f':
 259           if (st)
 260             {
 261               base = base_name (st->orig_file_name);
 262               len += strlen (base) - 1;
 263             }
 264           break;
 265
 266         case 'p':
 267           to_decimal (getpid (), pidbuf, sizeof pidbuf);
 268           len += strlen (pidbuf) - 1;
 269           break;
 270
 271         case 'n':
 272           if (allow_n)
 273             {
 274               to_decimal (global_header_count + 1, pidbuf, sizeof pidbuf);
 275               len += strlen (nbuf) - 1;
 276             }
 277           break;
 278         }
 279       p++;
 280     }
 281
 282   buf = xmalloc (len + 1);
 283   for (q = buf, p = fmt; *p; )
 284     {
 285       if (*p == '%')
 286         {
 287           switch (p[1])
 288             {
 289             case '%':
 290               *q++ = *p++;
 291               p++;
 292               break;
 293
 294             case 'd':
 295               if (dir)
 296                 q = stpcpy (q, dir);
 297               p += 2;
 298               break;
 299
 300             case 'f':
 301               if (base)
 302                 q = stpcpy (q, base);
 303               p += 2;
 304               break;
 305
 306             case 'p':
 307               q = stpcpy (q, pidbuf);
 308               p += 2;
 309               break;
 310
 311             case 'n':
 312               if (allow_n)
 313                 {
 314                   q = stpcpy (q, nbuf);
 315                   p += 2;
 316                 }
 317               /* else fall through */
 318
 319             default:
 320               *q++ = *p++;
 321               if (*p)
 322                 *q++ = *p++;
 323             }
 324         }
 325       else
 326         *q++ = *p++;
 327     }
 328
 329   /* Do not allow it to end in a slash */
 330   while (q > buf && ISSLASH (q[-1]))
 331     q--;
 332   *q = 0;
 333   return buf;
 334 }
 335
 336 char *
 337 xheader_xhdr_name (struct tar_stat_info *st)
 338 {
 339   if (!exthdr_name)
 340     assign_string (&exthdr_name, "%d/PaxHeaders.%p/%f");
 341   return xheader_format_name (st, exthdr_name, false);
 342 }
 343
 344 #define GLOBAL_HEADER_TEMPLATE "/GlobalHead.%p.%n"
 345
 346 char *
 347 xheader_ghdr_name (void)
 348 {
 349   if (!globexthdr_name)
 350     {
 351       size_t len;
 352       const char *tmp = getenv ("TMPDIR");
 353       if (!tmp)
 354         tmp = "/tmp";
 355       len = strlen (tmp) + sizeof (GLOBAL_HEADER_TEMPLATE); /* Includes nul */
 356       globexthdr_name = xmalloc (len);
 357       strcpy(globexthdr_name, tmp);
 358       strcat(globexthdr_name, GLOBAL_HEADER_TEMPLATE);
 359     }
 360
 361   return xheader_format_name (NULL, globexthdr_name, true);
 362 }
 363
 364 void
 365 xheader_write (char type, char *name, struct xheader *xhdr)
 366 {
 367   union block *header;
 368   size_t size;
 369   char *p;
 370
 371   size = xhdr->size;
 372   header = start_private_header (name, size);
 373   header->header.typeflag = type;
 374
 375   simple_finish_header (header);
 376
 377   p = xhdr->buffer;
 378
 379   do
 380     {
 381       size_t len;
 382
 383       header = find_next_block ();
 384       len = BLOCKSIZE;
 385       if (len > size)
 386         len = size;
 387       memcpy (header->buffer, p, len);
 388       if (len < BLOCKSIZE)
 389         memset (header->buffer + len, 0, BLOCKSIZE - len);
 390       p += len;
 391       size -= len;
 392       set_next_block_after (header);
 393     }
 394   while (size > 0);
 395   xheader_destroy (xhdr);
 396 }
 397
 398 void
 399 xheader_write_global (void)
 400 {
 401   char *name;
 402   struct keyword_list *kp;
 403
 404   if (!keyword_global_override_list)
 405     return;
 406
 407   extended_header_init ();
 408   for (kp = keyword_global_override_list; kp; kp = kp->next)
 409     code_string (kp->value, kp->pattern, &extended_header);
 410   xheader_finish (&extended_header);
 411   xheader_write (XGLTYPE, name = xheader_ghdr_name (),
 412                  &extended_header);
 413   free (name);
 414   global_header_count++;
 415 }
 416
 417 \f
 418 /* General Interface */
 419
 420 struct xhdr_tab
 421 {
 422   char const *keyword;
 423   void (*coder) (struct tar_stat_info const *, char const *,
 424                  struct xheader *, void *data);
 425   void (*decoder) (struct tar_stat_info *, char const *);
 426   bool protect;
 427 };
 428
 429 /* This declaration must be extern, because ISO C99 section 6.9.2
 430    prohibits a tentative definition that has both internal linkage and
 431    incomplete type.  If we made it static, we'd have to declare its
 432    size which would be a maintenance pain; if we put its initializer
 433    here, we'd need a boatload of forward declarations, which would be
 434    even more of a pain.  */
 435 extern struct xhdr_tab const xhdr_tab[];
 436
 437 static struct xhdr_tab const *
 438 locate_handler (char const *keyword)
 439 {
 440   struct xhdr_tab const *p;
 441
 442   for (p = xhdr_tab; p->keyword; p++)
 443     if (strcmp (p->keyword, keyword) == 0)
 444       return p;
 445   return NULL;
 446 }
 447
 448 static bool
 449 xheader_protected_pattern_p (const char *pattern)
 450 {
 451   struct xhdr_tab const *p;
 452
 453   for (p = xhdr_tab; p->keyword; p++)
 454     if (p->protect && fnmatch (pattern, p->keyword, 0) == 0)
 455       return true;
 456   return false;
 457 }
 458
 459 static bool
 460 xheader_protected_keyword_p (const char *keyword)
 461 {
 462   struct xhdr_tab const *p;
 463
 464   for (p = xhdr_tab; p->keyword; p++)
 465     if (p->protect && strcmp (p->keyword, keyword) == 0)
 466       return true;
 467   return false;
 468 }
 469
 470 /* Decodes a single extended header record. Advances P to the next
 471    record.
 472    Returns true on success, false otherwise. */
 473 static bool
 474 decode_record (char **p,
 475                void (*handler) (void *, char const *, char const *),
 476                void *data)
 477 {
 478   size_t len;
 479   char const *keyword;
 480   char *start = *p;
 481   char endc;
 482
 483   if (**p == 0)
 484     return false;
 485
 486   len = strtoul (*p, p, 10);
 487   if (**p != ' ')
 488     {
 489       ERROR ((0, 0,
 490        _("Malformed extended header: missing whitespace after the length")));
 491       return false;
 492     }
 493
 494   keyword = ++*p;
 495   for (;*p < start + len; ++*p)
 496     if (**p == '=')
 497       break;
 498
 499   if (**p != '=')
 500     {
 501       ERROR ((0, 0, _("Malformed extended header: missing equal sign")));
 502       return false;
 503     }
 504
 505   **p = 0;
 506
 507   endc = start[len-1];
 508   start[len-1] = 0;
 509
 510   handler (data, keyword, *p + 1);
 511
 512   start[len-1] = endc;
 513   **p = '=';
 514   *p = &start[len];
 515   return true;
 516 }
 517
 518 static void
 519 run_override_list (struct keyword_list *kp, struct tar_stat_info *st)
 520 {
 521   for (; kp; kp = kp->next)
 522     {
 523       struct xhdr_tab const *t = locate_handler (kp->pattern);
 524       if (t)
 525         t->decoder (st, kp->value);
 526     }
 527 }
 528
 529 static void
 530 decx (void *data, char const *keyword, char const *value)
 531 {
 532   struct xhdr_tab const *t;
 533   struct tar_stat_info *st = data;
 534
 535   if (xheader_keyword_deleted_p (keyword)
 536       || xheader_keyword_override_p (keyword))
 537     return;
 538
 539   t = locate_handler (keyword);
 540   if (t)
 541     t->decoder (st, value);
 542 }
 543
 544 void
 545 xheader_decode (struct tar_stat_info *st)
 546 {
 547   run_override_list (keyword_global_override_list, st);
 548   run_override_list (global_header_override_list, st);
 549
 550   if (extended_header.size)
 551     {
 552       char *p = extended_header.buffer + BLOCKSIZE;
 553       char *endp = &extended_header.buffer[extended_header.size-1];
 554
 555       while (p < endp)
 556         if (!decode_record (&p, decx, st))
 557           break;
 558     }
 559   run_override_list (keyword_override_list, st);
 560 }
 561
 562 static void
 563 decg (void *data, char const *keyword, char const *value)
 564 {
 565   struct keyword_list **kwl = data;
 566   xheader_list_append (kwl, keyword, value);
 567 }
 568
 569 void
 570 xheader_decode_global (void)
 571 {
 572   if (extended_header.size)
 573     {
 574       char *p = extended_header.buffer + BLOCKSIZE;
 575       char *endp = &extended_header.buffer[extended_header.size-1];
 576
 577       xheader_list_destroy (&global_header_override_list);
 578       while (p < endp)
 579         if (!decode_record (&p, decg, &global_header_override_list))
 580           break;
 581     }
 582 }
 583
 584 static void
 585 extended_header_init (void)
 586 {
 587   if (!extended_header.stk)
 588     {
 589       extended_header.stk = xmalloc (sizeof *extended_header.stk);
 590       obstack_init (extended_header.stk);
 591     }
 592 }
 593
 594 void
 595 xheader_store (char const *keyword, struct tar_stat_info const *st, void *data)
 596 {
 597   struct xhdr_tab const *t;
 598
 599   if (extended_header.buffer)
 600     return;
 601   t = locate_handler (keyword);
 602   if (!t)
 603     return;
 604   if (xheader_keyword_deleted_p (keyword)
 605       || xheader_keyword_override_p (keyword))
 606     return;
 607   extended_header_init ();
 608   t->coder (st, keyword, &extended_header, data);
 609 }
 610
 611 void
 612 xheader_read (union block *p, size_t size)
 613 {
 614   size_t j = 0;
 615   size_t nblocks;
 616
 617   free (extended_header.buffer);
 618   size += BLOCKSIZE;
 619   extended_header.size = size;
 620   nblocks = (size + BLOCKSIZE - 1) / BLOCKSIZE;
 621   extended_header.buffer = xmalloc (size + 1);
 622
 623   do
 624     {
 625       size_t len = size;
 626
 627       if (len > BLOCKSIZE)
 628         len = BLOCKSIZE;
 629
 630       memcpy (&extended_header.buffer[j], p->buffer, len);
 631       set_next_block_after (p);
 632
 633       p = find_next_block ();
 634
 635       j += len;
 636       size -= len;
 637     }
 638   while (size > 0);
 639 }
 640
 641 static size_t
 642 format_uintmax (uintmax_t val, char *buf, size_t s)
 643 {
 644   if (!buf)
 645     {
 646       s = 0;
 647       do
 648         s++;
 649       while ((val /= 10) != 0);
 650     }
 651   else
 652     {
 653       char *p = buf + s - 1;
 654
 655       do
 656         {
 657           *p-- = val % 10 + '0';
 658         }
 659       while ((val /= 10) != 0);
 660
 661       while (p >= buf)
 662         *p-- = '0';
 663     }
 664   return s;
 665 }
 666
 667 static void
 668 xheader_print (struct xheader *xhdr, char const *keyword, char const *value)
 669 {
 670   size_t len = strlen (keyword) + strlen (value) + 3; /* ' ' + '=' + '\n' */
 671   size_t p, n = 0;
 672   char nbuf[100];
 673
 674   do
 675     {
 676       p = n;
 677       n = format_uintmax (len + p, NULL, 0);
 678     }
 679   while (n != p);
 680
 681   format_uintmax (len + n, nbuf, n);
 682   obstack_grow (xhdr->stk, nbuf, n);
 683   obstack_1grow (xhdr->stk, ' ');
 684   obstack_grow (xhdr->stk, keyword, strlen (keyword));
 685   obstack_1grow (xhdr->stk, '=');
 686   obstack_grow (xhdr->stk, value, strlen (value));
 687   obstack_1grow (xhdr->stk, '\n');
 688 }
 689
 690 void
 691 xheader_finish (struct xheader *xhdr)
 692 {
 693   struct keyword_list *kp;
 694
 695   for (kp = keyword_override_list; kp; kp = kp->next)
 696     code_string (kp->value, kp->pattern, xhdr);
 697
 698   obstack_1grow (xhdr->stk, 0);
 699   xhdr->buffer = obstack_finish (xhdr->stk);
 700   xhdr->size = strlen (xhdr->buffer);
 701 }
 702
 703 void
 704 xheader_destroy (struct xheader *xhdr)
 705 {
 706   if (xhdr->stk)
 707     {
 708       obstack_free (xhdr->stk, NULL);
 709       free (xhdr->stk);
 710       xhdr->stk = NULL;
 711     }
 712   else
 713     free (xhdr->buffer);
 714   xhdr->buffer = 0;
 715   xhdr->size = 0;
 716 }
 717
 718 \f
 719 /* Implementations */
 720 static void
 721 code_string (char const *string, char const *keyword, struct xheader *xhdr)
 722 {
 723   char *outstr;
 724   if (!utf8_convert (true, string, &outstr))
 725     {
 726       /* FIXME: report error */
 727       outstr = xstrdup (string);
 728     }
 729   xheader_print (xhdr, keyword, outstr);
 730   free (outstr);
 731 }
 732
 733 static void
 734 decode_string (char **string, char const *arg)
 735 {
 736   if (*string)
 737     {
 738       free (*string);
 739       *string = NULL;
 740     }
 741   if (!utf8_convert (false, arg, string))
 742     {
 743       /* FIXME: report error and act accordingly to --pax invalid=UTF-8 */
 744       assign_string (string, arg);
 745     }
 746 }
 747
 748 static void
 749 code_time (time_t t, unsigned long nano,
 750            char const *keyword, struct xheader *xhdr)
 751 {
 752   char sbuf[200];
 753   size_t s = format_uintmax (t, NULL, 0);
 754   if (s + 11 >= sizeof sbuf)
 755     return;
 756   format_uintmax (t, sbuf, s);
 757   sbuf[s++] = '.';
 758   s += format_uintmax (nano, sbuf + s, 9);
 759   sbuf[s] = 0;
 760   xheader_print (xhdr, keyword, sbuf);
 761 }
 762
 763 static void
 764 decode_time (char const *arg, time_t *secs, unsigned long *nsecs)
 765 {
 766   uintmax_t u;
 767   char *p;
 768   if (xstrtoumax (arg, &p, 10, &u, "") == LONGINT_OK)
 769     {
 770       *secs = u;
 771       if (*p == '.' && xstrtoumax (p+1, NULL, 10, &u, "") == LONGINT_OK)
 772         *nsecs = u;
 773     }
 774 }
 775
 776 static void
 777 code_num (uintmax_t value, char const *keyword, struct xheader *xhdr)
 778 {
 779   char sbuf[100];
 780   size_t s = format_uintmax (value, NULL, 0);
 781   format_uintmax (value, sbuf, s);
 782   sbuf[s] = 0;
 783   xheader_print (xhdr, keyword, sbuf);
 784 }
 785
 786 static void
 787 dummy_coder (struct tar_stat_info const *st __attribute__ ((unused)),
 788              char const *keyword __attribute__ ((unused)),
 789              struct xheader *xhdr __attribute__ ((unused)),
 790              void *data __attribute__ ((unused)))
 791 {
 792 }
 793
 794 static void
 795 dummy_decoder (struct tar_stat_info *st __attribute__ ((unused)),
 796                char const *arg __attribute__ ((unused)))
 797 {
 798 }
 799
 800 static void
 801 atime_coder (struct tar_stat_info const *st, char const *keyword,
 802              struct xheader *xhdr, void *data __attribute__ ((unused)))
 803 {
 804   code_time (st->stat.st_atime, st->atime_nsec, keyword, xhdr);
 805 }
 806
 807 static void
 808 atime_decoder (struct tar_stat_info *st, char const *arg)
 809 {
 810   decode_time (arg, &st->stat.st_atime, &st->atime_nsec);
 811 }
 812
 813 static void
 814 gid_coder (struct tar_stat_info const *st, char const *keyword,
 815            struct xheader *xhdr, void *data __attribute__ ((unused)))
 816 {
 817   code_num (st->stat.st_gid, keyword, xhdr);
 818 }
 819
 820 static void
 821 gid_decoder (struct tar_stat_info *st, char const *arg)
 822 {
 823   uintmax_t u;
 824   if (xstrtoumax (arg, NULL, 10, &u, "") == LONGINT_OK)
 825     st->stat.st_gid = u;
 826 }
 827
 828 static void
 829 gname_coder (struct tar_stat_info const *st, char const *keyword,
 830              struct xheader *xhdr, void *data __attribute__ ((unused)))
 831 {
 832   code_string (st->gname, keyword, xhdr);
 833 }
 834
 835 static void
 836 gname_decoder (struct tar_stat_info *st, char const *arg)
 837 {
 838   decode_string (&st->gname, arg);
 839 }
 840
 841 static void
 842 linkpath_coder (struct tar_stat_info const *st, char const *keyword,
 843                 struct xheader *xhdr, void *data __attribute__ ((unused)))
 844 {
 845   code_string (st->link_name, keyword, xhdr);
 846 }
 847
 848 static void
 849 linkpath_decoder (struct tar_stat_info *st, char const *arg)
 850 {
 851   decode_string (&st->link_name, arg);
 852 }
 853
 854 static void
 855 ctime_coder (struct tar_stat_info const *st, char const *keyword,
 856              struct xheader *xhdr, void *data __attribute__ ((unused)))
 857 {
 858   code_time (st->stat.st_ctime, st->ctime_nsec, keyword, xhdr);
 859 }
 860
 861 static void
 862 ctime_decoder (struct tar_stat_info *st, char const *arg)
 863 {
 864   decode_time (arg, &st->stat.st_ctime, &st->ctime_nsec);
 865 }
 866
 867 static void
 868 mtime_coder (struct tar_stat_info const *st, char const *keyword,
 869              struct xheader *xhdr, void *data __attribute__ ((unused)))
 870 {
 871   code_time (st->stat.st_mtime, st->mtime_nsec, keyword, xhdr);
 872 }
 873
 874 static void
 875 mtime_decoder (struct tar_stat_info *st, char const *arg)
 876 {
 877   decode_time (arg, &st->stat.st_mtime, &st->mtime_nsec);
 878 }
 879
 880 static void
 881 path_coder (struct tar_stat_info const *st, char const *keyword,
 882             struct xheader *xhdr, void *data __attribute__ ((unused)))
 883 {
 884   code_string (st->file_name, keyword, xhdr);
 885 }
 886
 887 static void
 888 path_decoder (struct tar_stat_info *st, char const *arg)
 889 {
 890   decode_string (&st->orig_file_name, arg);
 891   decode_string (&st->file_name, arg);
 892   st->had_trailing_slash = strip_trailing_slashes (st->file_name);
 893 }
 894
 895 static void
 896 size_coder (struct tar_stat_info const *st, char const *keyword,
 897             struct xheader *xhdr, void *data __attribute__ ((unused)))
 898 {
 899   code_num (st->stat.st_size, keyword, xhdr);
 900 }
 901
 902 static void
 903 size_decoder (struct tar_stat_info *st, char const *arg)
 904 {
 905   uintmax_t u;
 906   if (xstrtoumax (arg, NULL, 10, &u, "") == LONGINT_OK)
 907     st->archive_file_size = st->stat.st_size = u;
 908 }
 909
 910 static void
 911 uid_coder (struct tar_stat_info const *st, char const *keyword,
 912            struct xheader *xhdr, void *data __attribute__ ((unused)))
 913 {
 914   code_num (st->stat.st_uid, keyword, xhdr);
 915 }
 916
 917 static void
 918 uid_decoder (struct tar_stat_info *st, char const *arg)
 919 {
 920   uintmax_t u;
 921   if (xstrtoumax (arg, NULL, 10, &u, "") == LONGINT_OK)
 922     st->stat.st_uid = u;
 923 }
 924
 925 static void
 926 uname_coder (struct tar_stat_info const *st, char const *keyword,
 927              struct xheader *xhdr, void *data __attribute__ ((unused)))
 928 {
 929   code_string (st->uname, keyword, xhdr);
 930 }
 931
 932 static void
 933 uname_decoder (struct tar_stat_info *st, char const *arg)
 934 {
 935   decode_string (&st->uname, arg);
 936 }
 937
 938 static void
 939 sparse_size_coder (struct tar_stat_info const *st, char const *keyword,
 940              struct xheader *xhdr, void *data)
 941 {
 942   size_coder (st, keyword, xhdr, data);
 943 }
 944
 945 static void
 946 sparse_size_decoder (struct tar_stat_info *st, char const *arg)
 947 {
 948   uintmax_t u;
 949   if (xstrtoumax (arg, NULL, 10, &u, "") == LONGINT_OK)
 950     st->stat.st_size = u;
 951 }
 952
 953 static void
 954 sparse_numblocks_coder (struct tar_stat_info const *st, char const *keyword,
 955                         struct xheader *xhdr,
 956                         void *data __attribute__ ((unused)))
 957 {
 958   code_num (st->sparse_map_avail, keyword, xhdr);
 959 }
 960
 961 static void
 962 sparse_numblocks_decoder (struct tar_stat_info *st, char const *arg)
 963 {
 964   uintmax_t u;
 965   if (xstrtoumax (arg, NULL, 10, &u, "") == LONGINT_OK)
 966     {
 967       st->sparse_map_size = u;
 968       st->sparse_map = calloc(st->sparse_map_size, sizeof(st->sparse_map[0]));
 969       st->sparse_map_avail = 0;
 970     }
 971 }
 972
 973 static void
 974 sparse_offset_coder (struct tar_stat_info const *st, char const *keyword,
 975                      struct xheader *xhdr, void *data)
 976 {
 977   size_t i = *(size_t*)data;
 978   code_num (st->sparse_map[i].offset, keyword, xhdr);
 979 }
 980
 981 static void
 982 sparse_offset_decoder (struct tar_stat_info *st, char const *arg)
 983 {
 984   uintmax_t u;
 985   if (xstrtoumax (arg, NULL, 10, &u, "") == LONGINT_OK)
 986     st->sparse_map[st->sparse_map_avail].offset = u;
 987 }
 988
 989 static void
 990 sparse_numbytes_coder (struct tar_stat_info const *st, char const *keyword,
 991                      struct xheader *xhdr, void *data)
 992 {
 993   size_t i = *(size_t*)data;
 994   code_num (st->sparse_map[i].numbytes, keyword, xhdr);
 995 }
 996
 997 static void
 998 sparse_numbytes_decoder (struct tar_stat_info *st, char const *arg)
 999 {
1000   uintmax_t u;
1001   if (xstrtoumax (arg, NULL, 10, &u, "") == LONGINT_OK)
1002     {
1003       if (st->sparse_map_avail == st->sparse_map_size)
1004         {
1005           st->sparse_map_size *= 2;
1006           st->sparse_map = xrealloc (st->sparse_map,
1007                                      st->sparse_map_size
1008                                      * sizeof st->sparse_map[0]);
1009         }
1010       st->sparse_map[st->sparse_map_avail++].numbytes = u;
1011     }
1012 }
1013
1014 struct xhdr_tab const xhdr_tab[] = {
1015   { "atime",    atime_coder,    atime_decoder,    false },
1016   { "comment",  dummy_coder,    dummy_decoder,    false },
1017   { "charset",  dummy_coder,    dummy_decoder,    false },
1018   { "ctime",    ctime_coder,    ctime_decoder,    false },
1019   { "gid",      gid_coder,      gid_decoder,      false },
1020   { "gname",    gname_coder,    gname_decoder,    false },
1021   { "linkpath", linkpath_coder, linkpath_decoder, false },
1022   { "mtime",    mtime_coder,    mtime_decoder,    false },
1023   { "path",     path_coder,     path_decoder,     false },
1024   { "size",     size_coder,     size_decoder,     false },
1025   { "uid",      uid_coder,      uid_decoder,      false },
1026   { "uname",    uname_coder,    uname_decoder,    false },
1027
1028   /* Sparse file handling */
1029   { "GNU.sparse.size",       sparse_size_coder, sparse_size_decoder, true },
1030   { "GNU.sparse.numblocks",  sparse_numblocks_coder, sparse_numblocks_decoder,
1031     true },
1032   { "GNU.sparse.offset",     sparse_offset_coder, sparse_offset_decoder,
1033     true },
1034   { "GNU.sparse.numbytes",   sparse_numbytes_coder, sparse_numbytes_decoder,
1035     true },
1036
1037 #if 0 /* GNU private keywords (not yet implemented) */
1038
1039   /* The next directory entry actually contains the names of files
1040      that were in the directory at the time the dump was made.
1041      Supersedes GNUTYPE_DUMPDIR header type.  */
1042   { "GNU.dump.name",  dump_name_coder, dump_name_decoder, false },
1043   { "GNU.dump.status", dump_status_coder, dump_status_decoder, false },
1044
1045   /* Keeps the tape/volume header. May be present only in the global headers.
1046      Equivalent to GNUTYPE_VOLHDR.  */
1047   { "GNU.volume.header", volume_header_coder, volume_header_decoder, false },
1048
1049   /* These may be present in a first global header of the archive.
1050      They provide the same functionality as GNUTYPE_MULTIVOL header.
1051      The GNU.volume.size keeps the real_s_sizeleft value, which is
1052      otherwise kept in the size field of a multivolume header.  The
1053      GNU.volume.offset keeps the offset of the start of this volume,
1054      otherwise kept in oldgnu_header.offset.  */
1055   { "GNU.volume.size", volume_size_coder, volume_size_decoder, false },
1056   { "GNU.volume.offset", volume_offset_coder, volume_offset_decoder, false },
1057 #endif
1058
1059   { NULL, NULL, NULL, false }
1060 };