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

   1 /* POSIX extended headers for tar.
   2
   3    Copyright (C) 2003, 2004, 2005 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    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, 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 #include <fnmatch.h>
  30
  31 static bool xheader_protected_pattern_p (char const *pattern);
  32 static bool xheader_protected_keyword_p (char const *keyword);
  33 static void xheader_set_single_keyword (char *) __attribute__ ((noreturn));
  34
  35 /* Used by xheader_finish() */
  36 static void code_string (char const *string, char const *keyword,
  37                          struct xheader *xhdr);
  38 static void extended_header_init (void);
  39
  40 /* Number of global headers written so far. */
  41 static size_t global_header_count;
  42 /* FIXME: Possibly it should be reset after changing the volume.
  43    POSIX %n specification says that it is expanded to the sequence
  44    number of current global header in *the* archive. However, for
  45    multi-volume archives this will yield duplicate header names
  46    in different volumes, which I'd like to avoid. The best way
  47    to solve this would be to use per-archive header count as required
  48    by POSIX *and* set globexthdr.name to, say,
  49    $TMPDIR/GlobalHead.%p.$NUMVOLUME.%n.
  50
  51    However it should wait until buffer.c is finally rewritten */
  52
  53 \f
  54 /* Keyword options */
  55
  56 struct keyword_list
  57 {
  58   struct keyword_list *next;
  59   char *pattern;
  60   char *value;
  61 };
  62
  63
  64 /* List of keyword patterns set by delete= option */
  65 static struct keyword_list *keyword_pattern_list;
  66
  67 /* List of keyword/value pairs set by `keyword=value' option */
  68 static struct keyword_list *keyword_global_override_list;
  69
  70 /* List of keyword/value pairs set by `keyword:=value' option */
  71 static struct keyword_list *keyword_override_list;
  72
  73 /* List of keyword/value pairs decoded from the last 'g' type header */
  74 static struct keyword_list *global_header_override_list;
  75
  76 /* Template for the name field of an 'x' type header */
  77 static char *exthdr_name;
  78
  79 /* Template for the name field of a 'g' type header */
  80 static char *globexthdr_name;
  81
  82 static bool
  83 xheader_keyword_deleted_p (const char *kw)
  84 {
  85   struct keyword_list *kp;
  86
  87   for (kp = keyword_pattern_list; kp; kp = kp->next)
  88     if (fnmatch (kp->pattern, kw, 0) == 0)
  89       return true;
  90   return false;
  91 }
  92
  93 static bool
  94 xheader_keyword_override_p (const char *keyword)
  95 {
  96   struct keyword_list *kp;
  97
  98   for (kp = keyword_override_list; kp; kp = kp->next)
  99     if (strcmp (kp->pattern, keyword) == 0)
 100       return true;
 101   return false;
 102 }
 103
 104 static void
 105 xheader_list_append (struct keyword_list **root, char const *kw,
 106                      char const *value)
 107 {
 108   struct keyword_list *kp = xmalloc (sizeof *kp);
 109   kp->pattern = xstrdup (kw);
 110   kp->value = value ? xstrdup (value) : NULL;
 111   kp->next = *root;
 112   *root = kp;
 113 }
 114
 115 static void
 116 xheader_list_destroy (struct keyword_list **root)
 117 {
 118   if (root)
 119     {
 120       struct keyword_list *kw = *root;
 121       while (kw)
 122         {
 123           struct keyword_list *next = kw->next;
 124           free (kw->pattern);
 125           free (kw->value);
 126           free (kw);
 127           kw = next;
 128         }
 129       *root = NULL;
 130     }
 131 }
 132
 133 static void
 134 xheader_set_single_keyword (char *kw)
 135 {
 136   USAGE_ERROR ((0, 0, _("Keyword %s is unknown or not yet imlemented"), kw));
 137 }
 138
 139 static void
 140 xheader_set_keyword_equal (char *kw, char *eq)
 141 {
 142   bool global = true;
 143   char *p = eq;
 144
 145   if (eq[-1] == ':')
 146     {
 147       p--;
 148       global = false;
 149     }
 150
 151   while (p > kw && isspace (*p))
 152     p--;
 153
 154   *p = 0;
 155
 156   for (p = eq + 1; *p && isspace (*p); p++)
 157     ;
 158
 159   if (strcmp (kw, "delete") == 0)
 160     {
 161       if (xheader_protected_pattern_p (p))
 162         USAGE_ERROR ((0, 0, _("Pattern %s cannot be used"), quote (p)));
 163       xheader_list_append (&keyword_pattern_list, p, NULL);
 164     }
 165   else if (strcmp (kw, "exthdr.name") == 0)
 166     assign_string (&exthdr_name, p);
 167   else if (strcmp (kw, "globexthdr.name") == 0)
 168     assign_string (&globexthdr_name, p);
 169   else
 170     {
 171       if (xheader_protected_keyword_p (kw))
 172         USAGE_ERROR ((0, 0, _("Keyword %s cannot be overridden"), kw));
 173       if (global)
 174         xheader_list_append (&keyword_global_override_list, kw, p);
 175       else
 176         xheader_list_append (&keyword_override_list, kw, p);
 177     }
 178 }
 179
 180 void
 181 xheader_set_option (char *string)
 182 {
 183   char *token;
 184   for (token = strtok (string, ","); token; token = strtok (NULL, ","))
 185     {
 186       char *p = strchr (token, '=');
 187       if (!p)
 188         xheader_set_single_keyword (token);
 189       else
 190         xheader_set_keyword_equal (token, p);
 191     }
 192 }
 193
 194 static void
 195 to_decimal (uintmax_t value, char *where, size_t size)
 196 {
 197   size_t i = 0, j;
 198
 199   where[i++] = 0;
 200   do
 201     {
 202       where[i++] = '0' + value % 10;
 203       value /= 10;
 204     }
 205   while (i < size && value);
 206   for (j = 0, i--; j < i; j++, i--)
 207     {
 208       char c = where[j];
 209       where[j] = where[i];
 210       where[i] = c;
 211     }
 212 }
 213
 214 /*
 215     string Includes:          Replaced By:
 216      %d                       The directory name of the file,
 217                               equivalent to the result of the
 218                               dirname utility on the translated
 219                               file name.
 220      %f                       The filename of the file, equivalent
 221                               to the result of the basename
 222                               utility on the translated file name.
 223      %p                       The process ID of the pax process.
 224      %%                       A '%' character. */
 225
 226 static char *
 227 xheader_format_name (struct tar_stat_info *st, const char *fmt, bool allow_n)
 228 {
 229   char *buf;
 230   size_t len = strlen (fmt);
 231   char *q;
 232   const char *p;
 233   char *dir = NULL;
 234   char *base = NULL;
 235   char pidbuf[64];
 236   char nbuf[64];
 237
 238   for (p = fmt; *p && (p = strchr (p, '%')); )
 239     {
 240       switch (p[1])
 241         {
 242         case '%':
 243           len--;
 244           break;
 245
 246         case 'd':
 247           if (st)
 248             {
 249               dir = safer_name_suffix (dir_name (st->orig_file_name), false);
 250               len += strlen (dir) - 1;
 251             }
 252           break;
 253
 254         case 'f':
 255           if (st)
 256             {
 257               base = base_name (st->orig_file_name);
 258               len += strlen (base) - 1;
 259             }
 260           break;
 261
 262         case 'p':
 263           to_decimal (getpid (), pidbuf, sizeof pidbuf);
 264           len += strlen (pidbuf) - 1;
 265           break;
 266
 267         case 'n':
 268           if (allow_n)
 269             {
 270               to_decimal (global_header_count + 1, pidbuf, sizeof pidbuf);
 271               len += strlen (nbuf) - 1;
 272             }
 273           break;
 274         }
 275       p++;
 276     }
 277
 278   buf = xmalloc (len + 1);
 279   for (q = buf, p = fmt; *p; )
 280     {
 281       if (*p == '%')
 282         {
 283           switch (p[1])
 284             {
 285             case '%':
 286               *q++ = *p++;
 287               p++;
 288               break;
 289
 290             case 'd':
 291               if (dir)
 292                 q = stpcpy (q, dir);
 293               p += 2;
 294               break;
 295
 296             case 'f':
 297               if (base)
 298                 q = stpcpy (q, base);
 299               p += 2;
 300               break;
 301
 302             case 'p':
 303               q = stpcpy (q, pidbuf);
 304               p += 2;
 305               break;
 306
 307             case 'n':
 308               if (allow_n)
 309                 {
 310                   q = stpcpy (q, nbuf);
 311                   p += 2;
 312                 }
 313               /* else fall through */
 314
 315             default:
 316               *q++ = *p++;
 317               if (*p)
 318                 *q++ = *p++;
 319             }
 320         }
 321       else
 322         *q++ = *p++;
 323     }
 324
 325   /* Do not allow it to end in a slash */
 326   while (q > buf && ISSLASH (q[-1]))
 327     q--;
 328   *q = 0;
 329   return buf;
 330 }
 331
 332 char *
 333 xheader_xhdr_name (struct tar_stat_info *st)
 334 {
 335   if (!exthdr_name)
 336     assign_string (&exthdr_name, "%d/PaxHeaders.%p/%f");
 337   return xheader_format_name (st, exthdr_name, false);
 338 }
 339
 340 #define GLOBAL_HEADER_TEMPLATE "/GlobalHead.%p.%n"
 341
 342 char *
 343 xheader_ghdr_name (void)
 344 {
 345   if (!globexthdr_name)
 346     {
 347       size_t len;
 348       const char *tmp = getenv ("TMPDIR");
 349       if (!tmp)
 350         tmp = "/tmp";
 351       len = strlen (tmp) + sizeof (GLOBAL_HEADER_TEMPLATE); /* Includes nul */
 352       globexthdr_name = xmalloc (len);
 353       strcpy(globexthdr_name, tmp);
 354       strcat(globexthdr_name, GLOBAL_HEADER_TEMPLATE);
 355     }
 356
 357   return xheader_format_name (NULL, globexthdr_name, true);
 358 }
 359
 360 void
 361 xheader_write (char type, char *name, struct xheader *xhdr)
 362 {
 363   union block *header;
 364   size_t size;
 365   char *p;
 366
 367   size = xhdr->size;
 368   header = start_private_header (name, size);
 369   header->header.typeflag = type;
 370
 371   simple_finish_header (header);
 372
 373   p = xhdr->buffer;
 374
 375   do
 376     {
 377       size_t len;
 378
 379       header = find_next_block ();
 380       len = BLOCKSIZE;
 381       if (len > size)
 382         len = size;
 383       memcpy (header->buffer, p, len);
 384       if (len < BLOCKSIZE)
 385         memset (header->buffer + len, 0, BLOCKSIZE - len);
 386       p += len;
 387       size -= len;
 388       set_next_block_after (header);
 389     }
 390   while (size > 0);
 391   xheader_destroy (xhdr);
 392 }
 393
 394 void
 395 xheader_write_global (void)
 396 {
 397   char *name;
 398   struct keyword_list *kp;
 399
 400   if (!keyword_global_override_list)
 401     return;
 402
 403   extended_header_init ();
 404   for (kp = keyword_global_override_list; kp; kp = kp->next)
 405     code_string (kp->value, kp->pattern, &extended_header);
 406   xheader_finish (&extended_header);
 407   xheader_write (XGLTYPE, name = xheader_ghdr_name (),
 408                  &extended_header);
 409   free (name);
 410   global_header_count++;
 411 }
 412
 413 \f
 414 /* General Interface */
 415
 416 struct xhdr_tab
 417 {
 418   char const *keyword;
 419   void (*coder) (struct tar_stat_info const *, char const *,
 420                  struct xheader *, void *data);
 421   void (*decoder) (struct tar_stat_info *, char const *);
 422   bool protect;
 423 };
 424
 425 /* This declaration must be extern, because ISO C99 section 6.9.2
 426    prohibits a tentative definition that has both internal linkage and
 427    incomplete type.  If we made it static, we'd have to declare its
 428    size which would be a maintenance pain; if we put its initializer
 429    here, we'd need a boatload of forward declarations, which would be
 430    even more of a pain.  */
 431 extern struct xhdr_tab const xhdr_tab[];
 432
 433 static struct xhdr_tab const *
 434 locate_handler (char const *keyword)
 435 {
 436   struct xhdr_tab const *p;
 437
 438   for (p = xhdr_tab; p->keyword; p++)
 439     if (strcmp (p->keyword, keyword) == 0)
 440       return p;
 441   return NULL;
 442 }
 443
 444 static bool
 445 xheader_protected_pattern_p (const char *pattern)
 446 {
 447   struct xhdr_tab const *p;
 448
 449   for (p = xhdr_tab; p->keyword; p++)
 450     if (p->protect && fnmatch (pattern, p->keyword, 0) == 0)
 451       return true;
 452   return false;
 453 }
 454
 455 static bool
 456 xheader_protected_keyword_p (const char *keyword)
 457 {
 458   struct xhdr_tab const *p;
 459
 460   for (p = xhdr_tab; p->keyword; p++)
 461     if (p->protect && strcmp (p->keyword, keyword) == 0)
 462       return true;
 463   return false;
 464 }
 465
 466 /* Decode a single extended header record, advancing *PTR to the next record.
 467    Return true on success, false otherwise.  */
 468 static bool
 469 decode_record (char **ptr,
 470                void (*handler) (void *, char const *, char const *),
 471                void *data)
 472 {
 473   char *start = *ptr;
 474   char *p = start;
 475   unsigned long int len;
 476   char *len_lim;
 477   char const *keyword;
 478   char *nextp;
 479   size_t len_max = extended_header.buffer + extended_header.size - start;
 480
 481   while (*p == ' ' || *p == '\t')
 482     p++;
 483
 484   if (! ISDIGIT (*p))
 485     {
 486       if (*p)
 487         ERROR ((0, 0, _("Malformed extended header: missing length")));
 488       return false;
 489     }
 490
 491   errno = 0;
 492   len = strtoul (p, &len_lim, 10);
 493
 494   if (len_max < len || (len == ULONG_MAX && errno == ERANGE))
 495     {
 496       ERROR ((0, 0, _("Malformed extended header: length out of range")));
 497       return false;
 498     }
 499
 500   nextp = start + len;
 501
 502   for (p = len_lim; *p == ' ' || *p == '\t'; p++)
 503     continue;
 504   if (p == len_lim)
 505     {
 506       ERROR ((0, 0,
 507               _("Malformed extended header: missing blank after length")));
 508       return false;
 509     }
 510
 511   keyword = p;
 512   p = strchr (p, '=');
 513   if (! (p && p < nextp))
 514     {
 515       ERROR ((0, 0, _("Malformed extended header: missing equal sign")));
 516       return false;
 517     }
 518
 519   if (nextp[-1] != '\n')
 520     {
 521       ERROR ((0, 0, _("Malformed extended header: missing newline")));
 522       return false;
 523     }
 524
 525   *p = nextp[-1] = '\0';
 526   handler (data, keyword, p + 1);
 527   *p = '=';
 528   nextp[-1] = '\n';
 529   *ptr = nextp;
 530   return true;
 531 }
 532
 533 static void
 534 run_override_list (struct keyword_list *kp, struct tar_stat_info *st)
 535 {
 536   for (; kp; kp = kp->next)
 537     {
 538       struct xhdr_tab const *t = locate_handler (kp->pattern);
 539       if (t)
 540         t->decoder (st, kp->value);
 541     }
 542 }
 543
 544 static void
 545 decx (void *data, char const *keyword, char const *value)
 546 {
 547   struct xhdr_tab const *t;
 548   struct tar_stat_info *st = data;
 549
 550   if (xheader_keyword_deleted_p (keyword)
 551       || xheader_keyword_override_p (keyword))
 552     return;
 553
 554   t = locate_handler (keyword);
 555   if (t)
 556     t->decoder (st, value);
 557 }
 558
 559 void
 560 xheader_decode (struct tar_stat_info *st)
 561 {
 562   run_override_list (keyword_global_override_list, st);
 563   run_override_list (global_header_override_list, st);
 564
 565   if (extended_header.size)
 566     {
 567       char *p = extended_header.buffer + BLOCKSIZE;
 568       while (decode_record (&p, decx, st))
 569         continue;
 570     }
 571   run_override_list (keyword_override_list, st);
 572 }
 573
 574 static void
 575 decg (void *data, char const *keyword, char const *value)
 576 {
 577   struct keyword_list **kwl = data;
 578   xheader_list_append (kwl, keyword, value);
 579 }
 580
 581 void
 582 xheader_decode_global (void)
 583 {
 584   if (extended_header.size)
 585     {
 586       char *p = extended_header.buffer + BLOCKSIZE;
 587
 588       xheader_list_destroy (&global_header_override_list);
 589       while (decode_record (&p, decg, &global_header_override_list))
 590         continue;
 591     }
 592 }
 593
 594 static void
 595 extended_header_init (void)
 596 {
 597   if (!extended_header.stk)
 598     {
 599       extended_header.stk = xmalloc (sizeof *extended_header.stk);
 600       obstack_init (extended_header.stk);
 601     }
 602 }
 603
 604 void
 605 xheader_store (char const *keyword, struct tar_stat_info const *st, void *data)
 606 {
 607   struct xhdr_tab const *t;
 608
 609   if (extended_header.buffer)
 610     return;
 611   t = locate_handler (keyword);
 612   if (!t)
 613     return;
 614   if (xheader_keyword_deleted_p (keyword)
 615       || xheader_keyword_override_p (keyword))
 616     return;
 617   extended_header_init ();
 618   t->coder (st, keyword, &extended_header, data);
 619 }
 620
 621 void
 622 xheader_read (union block *p, size_t size)
 623 {
 624   size_t j = 0;
 625   size_t nblocks;
 626
 627   free (extended_header.buffer);
 628   size += BLOCKSIZE;
 629   extended_header.size = size;
 630   nblocks = (size + BLOCKSIZE - 1) / BLOCKSIZE;
 631   extended_header.buffer = xmalloc (size + 1);
 632   extended_header.buffer[size] = '\0';
 633
 634   do
 635     {
 636       size_t len = size;
 637
 638       if (len > BLOCKSIZE)
 639         len = BLOCKSIZE;
 640
 641       memcpy (&extended_header.buffer[j], p->buffer, len);
 642       set_next_block_after (p);
 643
 644       p = find_next_block ();
 645
 646       j += len;
 647       size -= len;
 648     }
 649   while (size > 0);
 650 }
 651
 652 static size_t
 653 format_uintmax (uintmax_t val, char *buf, size_t s)
 654 {
 655   if (!buf)
 656     {
 657       s = 0;
 658       do
 659         s++;
 660       while ((val /= 10) != 0);
 661     }
 662   else
 663     {
 664       char *p = buf + s - 1;
 665
 666       do
 667         {
 668           *p-- = val % 10 + '0';
 669         }
 670       while ((val /= 10) != 0);
 671
 672       while (p >= buf)
 673         *p-- = '0';
 674     }
 675   return s;
 676 }
 677
 678 static void
 679 xheader_print (struct xheader *xhdr, char const *keyword, char const *value)
 680 {
 681   size_t len = strlen (keyword) + strlen (value) + 3; /* ' ' + '=' + '\n' */
 682   size_t p, n = 0;
 683   char nbuf[100];
 684
 685   do
 686     {
 687       p = n;
 688       n = format_uintmax (len + p, NULL, 0);
 689     }
 690   while (n != p);
 691
 692   format_uintmax (len + n, nbuf, n);
 693   obstack_grow (xhdr->stk, nbuf, n);
 694   obstack_1grow (xhdr->stk, ' ');
 695   obstack_grow (xhdr->stk, keyword, strlen (keyword));
 696   obstack_1grow (xhdr->stk, '=');
 697   obstack_grow (xhdr->stk, value, strlen (value));
 698   obstack_1grow (xhdr->stk, '\n');
 699 }
 700
 701 void
 702 xheader_finish (struct xheader *xhdr)
 703 {
 704   struct keyword_list *kp;
 705
 706   for (kp = keyword_override_list; kp; kp = kp->next)
 707     code_string (kp->value, kp->pattern, xhdr);
 708
 709   obstack_1grow (xhdr->stk, 0);
 710   xhdr->buffer = obstack_finish (xhdr->stk);
 711   xhdr->size = strlen (xhdr->buffer);
 712 }
 713
 714 void
 715 xheader_destroy (struct xheader *xhdr)
 716 {
 717   if (xhdr->stk)
 718     {
 719       obstack_free (xhdr->stk, NULL);
 720       free (xhdr->stk);
 721       xhdr->stk = NULL;
 722     }
 723   else
 724     free (xhdr->buffer);
 725   xhdr->buffer = 0;
 726   xhdr->size = 0;
 727 }
 728
 729 \f
 730 /* Implementations */
 731 static void
 732 code_string (char const *string, char const *keyword, struct xheader *xhdr)
 733 {
 734   char *outstr;
 735   if (!utf8_convert (true, string, &outstr))
 736     {
 737       /* FIXME: report error */
 738       outstr = xstrdup (string);
 739     }
 740   xheader_print (xhdr, keyword, outstr);
 741   free (outstr);
 742 }
 743
 744 static void
 745 decode_string (char **string, char const *arg)
 746 {
 747   if (*string)
 748     {
 749       free (*string);
 750       *string = NULL;
 751     }
 752   if (!utf8_convert (false, arg, string))
 753     {
 754       /* FIXME: report error and act accordingly to --pax invalid=UTF-8 */
 755       assign_string (string, arg);
 756     }
 757 }
 758
 759 static void
 760 code_time (time_t t, unsigned long nano,
 761            char const *keyword, struct xheader *xhdr)
 762 {
 763   char sbuf[200];
 764   size_t s = format_uintmax (t, NULL, 0);
 765   if (s + 11 >= sizeof sbuf)
 766     return;
 767   format_uintmax (t, sbuf, s);
 768   sbuf[s++] = '.';
 769   s += format_uintmax (nano, sbuf + s, 9);
 770   sbuf[s] = 0;
 771   xheader_print (xhdr, keyword, sbuf);
 772 }
 773
 774 static void
 775 decode_time (char const *arg, time_t *secs, unsigned long *nsecs)
 776 {
 777   uintmax_t u;
 778   char *p;
 779   if (xstrtoumax (arg, &p, 10, &u, "") == LONGINT_OK)
 780     {
 781       *secs = u;
 782       if (*p == '.' && xstrtoumax (p+1, NULL, 10, &u, "") == LONGINT_OK)
 783         *nsecs = u;
 784     }
 785 }
 786
 787 static void
 788 code_num (uintmax_t value, char const *keyword, struct xheader *xhdr)
 789 {
 790   char sbuf[100];
 791   size_t s = format_uintmax (value, NULL, 0);
 792   format_uintmax (value, sbuf, s);
 793   sbuf[s] = 0;
 794   xheader_print (xhdr, keyword, sbuf);
 795 }
 796
 797 static void
 798 dummy_coder (struct tar_stat_info const *st __attribute__ ((unused)),
 799              char const *keyword __attribute__ ((unused)),
 800              struct xheader *xhdr __attribute__ ((unused)),
 801              void *data __attribute__ ((unused)))
 802 {
 803 }
 804
 805 static void
 806 dummy_decoder (struct tar_stat_info *st __attribute__ ((unused)),
 807                char const *arg __attribute__ ((unused)))
 808 {
 809 }
 810
 811 static void
 812 atime_coder (struct tar_stat_info const *st, char const *keyword,
 813              struct xheader *xhdr, void *data __attribute__ ((unused)))
 814 {
 815   code_time (st->stat.st_atime, st->atime_nsec, keyword, xhdr);
 816 }
 817
 818 static void
 819 atime_decoder (struct tar_stat_info *st, char const *arg)
 820 {
 821   decode_time (arg, &st->stat.st_atime, &st->atime_nsec);
 822 }
 823
 824 static void
 825 gid_coder (struct tar_stat_info const *st, char const *keyword,
 826            struct xheader *xhdr, void *data __attribute__ ((unused)))
 827 {
 828   code_num (st->stat.st_gid, keyword, xhdr);
 829 }
 830
 831 static void
 832 gid_decoder (struct tar_stat_info *st, char const *arg)
 833 {
 834   uintmax_t u;
 835   if (xstrtoumax (arg, NULL, 10, &u, "") == LONGINT_OK)
 836     st->stat.st_gid = u;
 837 }
 838
 839 static void
 840 gname_coder (struct tar_stat_info const *st, char const *keyword,
 841              struct xheader *xhdr, void *data __attribute__ ((unused)))
 842 {
 843   code_string (st->gname, keyword, xhdr);
 844 }
 845
 846 static void
 847 gname_decoder (struct tar_stat_info *st, char const *arg)
 848 {
 849   decode_string (&st->gname, arg);
 850 }
 851
 852 static void
 853 linkpath_coder (struct tar_stat_info const *st, char const *keyword,
 854                 struct xheader *xhdr, void *data __attribute__ ((unused)))
 855 {
 856   code_string (st->link_name, keyword, xhdr);
 857 }
 858
 859 static void
 860 linkpath_decoder (struct tar_stat_info *st, char const *arg)
 861 {
 862   decode_string (&st->link_name, arg);
 863 }
 864
 865 static void
 866 ctime_coder (struct tar_stat_info const *st, char const *keyword,
 867              struct xheader *xhdr, void *data __attribute__ ((unused)))
 868 {
 869   code_time (st->stat.st_ctime, st->ctime_nsec, keyword, xhdr);
 870 }
 871
 872 static void
 873 ctime_decoder (struct tar_stat_info *st, char const *arg)
 874 {
 875   decode_time (arg, &st->stat.st_ctime, &st->ctime_nsec);
 876 }
 877
 878 static void
 879 mtime_coder (struct tar_stat_info const *st, char const *keyword,
 880              struct xheader *xhdr, void *data __attribute__ ((unused)))
 881 {
 882   code_time (st->stat.st_mtime, st->mtime_nsec, keyword, xhdr);
 883 }
 884
 885 static void
 886 mtime_decoder (struct tar_stat_info *st, char const *arg)
 887 {
 888   decode_time (arg, &st->stat.st_mtime, &st->mtime_nsec);
 889 }
 890
 891 static void
 892 path_coder (struct tar_stat_info const *st, char const *keyword,
 893             struct xheader *xhdr, void *data __attribute__ ((unused)))
 894 {
 895   code_string (st->file_name, keyword, xhdr);
 896 }
 897
 898 static void
 899 path_decoder (struct tar_stat_info *st, char const *arg)
 900 {
 901   decode_string (&st->orig_file_name, arg);
 902   decode_string (&st->file_name, arg);
 903   st->had_trailing_slash = strip_trailing_slashes (st->file_name);
 904 }
 905
 906 static void
 907 size_coder (struct tar_stat_info const *st, char const *keyword,
 908             struct xheader *xhdr, void *data __attribute__ ((unused)))
 909 {
 910   code_num (st->stat.st_size, keyword, xhdr);
 911 }
 912
 913 static void
 914 size_decoder (struct tar_stat_info *st, char const *arg)
 915 {
 916   uintmax_t u;
 917   if (xstrtoumax (arg, NULL, 10, &u, "") == LONGINT_OK)
 918     st->archive_file_size = st->stat.st_size = u;
 919 }
 920
 921 static void
 922 uid_coder (struct tar_stat_info const *st, char const *keyword,
 923            struct xheader *xhdr, void *data __attribute__ ((unused)))
 924 {
 925   code_num (st->stat.st_uid, keyword, xhdr);
 926 }
 927
 928 static void
 929 uid_decoder (struct tar_stat_info *st, char const *arg)
 930 {
 931   uintmax_t u;
 932   if (xstrtoumax (arg, NULL, 10, &u, "") == LONGINT_OK)
 933     st->stat.st_uid = u;
 934 }
 935
 936 static void
 937 uname_coder (struct tar_stat_info const *st, char const *keyword,
 938              struct xheader *xhdr, void *data __attribute__ ((unused)))
 939 {
 940   code_string (st->uname, keyword, xhdr);
 941 }
 942
 943 static void
 944 uname_decoder (struct tar_stat_info *st, char const *arg)
 945 {
 946   decode_string (&st->uname, arg);
 947 }
 948
 949 static void
 950 sparse_size_coder (struct tar_stat_info const *st, char const *keyword,
 951              struct xheader *xhdr, void *data)
 952 {
 953   size_coder (st, keyword, xhdr, data);
 954 }
 955
 956 static void
 957 sparse_size_decoder (struct tar_stat_info *st, char const *arg)
 958 {
 959   uintmax_t u;
 960   if (xstrtoumax (arg, NULL, 10, &u, "") == LONGINT_OK)
 961     st->stat.st_size = u;
 962 }
 963
 964 static void
 965 sparse_numblocks_coder (struct tar_stat_info const *st, char const *keyword,
 966                         struct xheader *xhdr,
 967                         void *data __attribute__ ((unused)))
 968 {
 969   code_num (st->sparse_map_avail, keyword, xhdr);
 970 }
 971
 972 static void
 973 sparse_numblocks_decoder (struct tar_stat_info *st, char const *arg)
 974 {
 975   uintmax_t u;
 976   if (xstrtoumax (arg, NULL, 10, &u, "") == LONGINT_OK)
 977     {
 978       st->sparse_map_size = u;
 979       st->sparse_map = calloc(st->sparse_map_size, sizeof(st->sparse_map[0]));
 980       st->sparse_map_avail = 0;
 981     }
 982 }
 983
 984 static void
 985 sparse_offset_coder (struct tar_stat_info const *st, char const *keyword,
 986                      struct xheader *xhdr, void *data)
 987 {
 988   size_t i = *(size_t*)data;
 989   code_num (st->sparse_map[i].offset, keyword, xhdr);
 990 }
 991
 992 static void
 993 sparse_offset_decoder (struct tar_stat_info *st, char const *arg)
 994 {
 995   uintmax_t u;
 996   if (xstrtoumax (arg, NULL, 10, &u, "") == LONGINT_OK)
 997     st->sparse_map[st->sparse_map_avail].offset = u;
 998 }
 999
1000 static void
1001 sparse_numbytes_coder (struct tar_stat_info const *st, char const *keyword,
1002                      struct xheader *xhdr, void *data)
1003 {
1004   size_t i = *(size_t*)data;
1005   code_num (st->sparse_map[i].numbytes, keyword, xhdr);
1006 }
1007
1008 static void
1009 sparse_numbytes_decoder (struct tar_stat_info *st, char const *arg)
1010 {
1011   uintmax_t u;
1012   if (xstrtoumax (arg, NULL, 10, &u, "") == LONGINT_OK)
1013     {
1014       if (st->sparse_map_avail == st->sparse_map_size)
1015         {
1016           st->sparse_map_size *= 2;
1017           st->sparse_map = xrealloc (st->sparse_map,
1018                                      st->sparse_map_size
1019                                      * sizeof st->sparse_map[0]);
1020         }
1021       st->sparse_map[st->sparse_map_avail++].numbytes = u;
1022     }
1023 }
1024
1025 struct xhdr_tab const xhdr_tab[] = {
1026   { "atime",    atime_coder,    atime_decoder,    false },
1027   { "comment",  dummy_coder,    dummy_decoder,    false },
1028   { "charset",  dummy_coder,    dummy_decoder,    false },
1029   { "ctime",    ctime_coder,    ctime_decoder,    false },
1030   { "gid",      gid_coder,      gid_decoder,      false },
1031   { "gname",    gname_coder,    gname_decoder,    false },
1032   { "linkpath", linkpath_coder, linkpath_decoder, false },
1033   { "mtime",    mtime_coder,    mtime_decoder,    false },
1034   { "path",     path_coder,     path_decoder,     false },
1035   { "size",     size_coder,     size_decoder,     false },
1036   { "uid",      uid_coder,      uid_decoder,      false },
1037   { "uname",    uname_coder,    uname_decoder,    false },
1038
1039   /* Sparse file handling */
1040   { "GNU.sparse.size",       sparse_size_coder, sparse_size_decoder, true },
1041   { "GNU.sparse.numblocks",  sparse_numblocks_coder, sparse_numblocks_decoder,
1042     true },
1043   { "GNU.sparse.offset",     sparse_offset_coder, sparse_offset_decoder,
1044     true },
1045   { "GNU.sparse.numbytes",   sparse_numbytes_coder, sparse_numbytes_decoder,
1046     true },
1047
1048 #if 0 /* GNU private keywords (not yet implemented) */
1049
1050   /* The next directory entry actually contains the names of files
1051      that were in the directory at the time the dump was made.
1052      Supersedes GNUTYPE_DUMPDIR header type.  */
1053   { "GNU.dump.name",  dump_name_coder, dump_name_decoder, false },
1054   { "GNU.dump.status", dump_status_coder, dump_status_decoder, false },
1055
1056   /* Keeps the tape/volume header. May be present only in the global headers.
1057      Equivalent to GNUTYPE_VOLHDR.  */
1058   { "GNU.volume.header", volume_header_coder, volume_header_decoder, false },
1059
1060   /* These may be present in a first global header of the archive.
1061      They provide the same functionality as GNUTYPE_MULTIVOL header.
1062      The GNU.volume.size keeps the real_s_sizeleft value, which is
1063      otherwise kept in the size field of a multivolume header.  The
1064      GNU.volume.offset keeps the offset of the start of this volume,
1065      otherwise kept in oldgnu_header.offset.  */
1066   { "GNU.volume.size", volume_size_coder, volume_size_decoder, false },
1067   { "GNU.volume.offset", volume_offset_coder, volume_offset_decoder, false },
1068 #endif
1069
1070   { NULL, NULL, NULL, false }
1071 };