contrib/libarchive/libarchive/archive_write_set_format_gnutar.c

   1 /*-
   2  * Copyright (c) 2010 Nokia Corporation and/or its subsidiary(-ies).
   3  * Author: Jonas Gastal <jgastal@profusion.mobi>
   4  * Copyright (c) 2011-2012 Michihiro NAKAJIMA
   5  *
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
  18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20  * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
  21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  */
  28
  29 #include "archive_platform.h"
  30 __FBSDID("$FreeBSD: head/lib/libarchive/archive_write_set_format_gnu_tar.c 191579 2009-04-27 18:35:03Z gastal $");
  31
  32
  33 #ifdef HAVE_ERRNO_H
  34 #include <errno.h>
  35 #endif
  36 #include <stdio.h>
  37 #ifdef HAVE_STDLIB_H
  38 #include <stdlib.h>
  39 #endif
  40 #ifdef HAVE_STRING_H
  41 #include <string.h>
  42 #endif
  43
  44 #include "archive.h"
  45 #include "archive_entry.h"
  46 #include "archive_entry_locale.h"
  47 #include "archive_private.h"
  48 #include "archive_write_private.h"
  49
  50 struct gnutar {
  51         uint64_t        entry_bytes_remaining;
  52         uint64_t        entry_padding;
  53         const char *    linkname;
  54         size_t          linkname_length;
  55         const char *    pathname;
  56         size_t          pathname_length;
  57         const char *    uname;
  58         size_t          uname_length;
  59         const char *    gname;
  60         size_t          gname_length;
  61         struct archive_string_conv *opt_sconv;
  62         struct archive_string_conv *sconv_default;
  63         int init_default_conversion;
  64 };
  65
  66 /*
  67  * Define structure of GNU tar header.
  68  */
  69 #define GNUTAR_name_offset 0
  70 #define GNUTAR_name_size 100
  71 #define GNUTAR_mode_offset 100
  72 #define GNUTAR_mode_size 7
  73 #define GNUTAR_mode_max_size 8
  74 #define GNUTAR_uid_offset 108
  75 #define GNUTAR_uid_size 7
  76 #define GNUTAR_uid_max_size 8
  77 #define GNUTAR_gid_offset 116
  78 #define GNUTAR_gid_size 7
  79 #define GNUTAR_gid_max_size 8
  80 #define GNUTAR_size_offset 124
  81 #define GNUTAR_size_size 11
  82 #define GNUTAR_size_max_size 12
  83 #define GNUTAR_mtime_offset 136
  84 #define GNUTAR_mtime_size 11
  85 #define GNUTAR_mtime_max_size 11
  86 #define GNUTAR_checksum_offset 148
  87 #define GNUTAR_checksum_size 8
  88 #define GNUTAR_typeflag_offset 156
  89 #define GNUTAR_typeflag_size 1
  90 #define GNUTAR_linkname_offset 157
  91 #define GNUTAR_linkname_size 100
  92 #define GNUTAR_magic_offset 257
  93 #define GNUTAR_magic_size 6
  94 #define GNUTAR_version_offset 263
  95 #define GNUTAR_version_size 2
  96 #define GNUTAR_uname_offset 265
  97 #define GNUTAR_uname_size 32
  98 #define GNUTAR_gname_offset 297
  99 #define GNUTAR_gname_size 32
 100 #define GNUTAR_rdevmajor_offset 329
 101 #define GNUTAR_rdevmajor_size 6
 102 #define GNUTAR_rdevmajor_max_size 8
 103 #define GNUTAR_rdevminor_offset 337
 104 #define GNUTAR_rdevminor_size 6
 105 #define GNUTAR_rdevminor_max_size 8
 106
 107 /*
 108  * A filled-in copy of the header for initialization.
 109  */
 110 static const char template_header[] = {
 111         /* name: 100 bytes */
 112         0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
 113         0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
 114         0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
 115         0,0,0,0,
 116         /* Mode, null termination: 8 bytes */
 117         '0','0','0','0','0','0', '0','\0',
 118         /* uid, null termination: 8 bytes */
 119         '0','0','0','0','0','0', '0','\0',
 120         /* gid, null termination: 8 bytes */
 121         '0','0','0','0','0','0', '0','\0',
 122         /* size, space termation: 12 bytes */
 123         '0','0','0','0','0','0','0','0','0','0','0', '\0',
 124         /* mtime, space termation: 12 bytes */
 125         '0','0','0','0','0','0','0','0','0','0','0', '\0',
 126         /* Initial checksum value: 8 spaces */
 127         ' ',' ',' ',' ',' ',' ',' ',' ',
 128         /* Typeflag: 1 byte */
 129         '0',                    /* '0' = regular file */
 130         /* Linkname: 100 bytes */
 131         0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
 132         0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
 133         0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
 134         0,0,0,0,
 135         /* Magic: 8 bytes */
 136         'u','s','t','a','r',' ', ' ','\0',
 137         /* Uname: 32 bytes */
 138         0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
 139         /* Gname: 32 bytes */
 140         0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
 141         /* rdevmajor + null padding: 8 bytes */
 142         '\0','\0','\0','\0','\0','\0', '\0','\0',
 143         /* rdevminor + null padding: 8 bytes */
 144         '\0','\0','\0','\0','\0','\0', '\0','\0',
 145         /* Padding: 167 bytes */
 146         0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
 147         0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
 148         0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
 149         0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
 150         0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
 151         0,0,0,0,0,0,0
 152 };
 153
 154 static int      archive_write_gnutar_options(struct archive_write *,
 155                     const char *, const char *);
 156 static int      archive_format_gnutar_header(struct archive_write *, char h[512],
 157                     struct archive_entry *, int tartype);
 158 static int      archive_write_gnutar_header(struct archive_write *,
 159                     struct archive_entry *entry);
 160 static ssize_t  archive_write_gnutar_data(struct archive_write *a, const void *buff,
 161                     size_t s);
 162 static int      archive_write_gnutar_free(struct archive_write *);
 163 static int      archive_write_gnutar_close(struct archive_write *);
 164 static int      archive_write_gnutar_finish_entry(struct archive_write *);
 165 static int      format_256(int64_t, char *, int);
 166 static int      format_number(int64_t, char *, int size, int maxsize);
 167 static int      format_octal(int64_t, char *, int);
 168
 169 /*
 170  * Set output format to 'GNU tar' format.
 171  */
 172 int
 173 archive_write_set_format_gnutar(struct archive *_a)
 174 {
 175         struct archive_write *a = (struct archive_write *)_a;
 176         struct gnutar *gnutar;
 177
 178         gnutar = (struct gnutar *)calloc(1, sizeof(*gnutar));
 179         if (gnutar == NULL) {
 180                 archive_set_error(&a->archive, ENOMEM,
 181                     "Can't allocate gnutar data");
 182                 return (ARCHIVE_FATAL);
 183         }
 184         a->format_data = gnutar;
 185         a->format_name = "gnutar";
 186         a->format_options = archive_write_gnutar_options;
 187         a->format_write_header = archive_write_gnutar_header;
 188         a->format_write_data = archive_write_gnutar_data;
 189         a->format_close = archive_write_gnutar_close;
 190         a->format_free = archive_write_gnutar_free;
 191         a->format_finish_entry = archive_write_gnutar_finish_entry;
 192         a->archive.archive_format = ARCHIVE_FORMAT_TAR_GNUTAR;
 193         a->archive.archive_format_name = "GNU tar";
 194         return (ARCHIVE_OK);
 195 }
 196
 197 static int
 198 archive_write_gnutar_options(struct archive_write *a, const char *key,
 199     const char *val)
 200 {
 201         struct gnutar *gnutar = (struct gnutar *)a->format_data;
 202         int ret = ARCHIVE_FAILED;
 203
 204         if (strcmp(key, "hdrcharset")  == 0) {
 205                 if (val == NULL || val[0] == 0)
 206                         archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
 207                             "%s: hdrcharset option needs a character-set name",
 208                             a->format_name);
 209                 else {
 210                         gnutar->opt_sconv = archive_string_conversion_to_charset(
 211                             &a->archive, val, 0);
 212                         if (gnutar->opt_sconv != NULL)
 213                                 ret = ARCHIVE_OK;
 214                         else
 215                                 ret = ARCHIVE_FATAL;
 216                 }
 217                 return (ret);
 218         }
 219
 220         /* Note: The "warn" return is just to inform the options
 221          * supervisor that we didn't handle it.  It will generate
 222          * a suitable error if no one used this option. */
 223         return (ARCHIVE_WARN);
 224 }
 225
 226 static int
 227 archive_write_gnutar_close(struct archive_write *a)
 228 {
 229         return (__archive_write_nulls(a, 512*2));
 230 }
 231
 232 static int
 233 archive_write_gnutar_free(struct archive_write *a)
 234 {
 235         struct gnutar *gnutar;
 236
 237         gnutar = (struct gnutar *)a->format_data;
 238         free(gnutar);
 239         a->format_data = NULL;
 240         return (ARCHIVE_OK);
 241 }
 242
 243 static int
 244 archive_write_gnutar_finish_entry(struct archive_write *a)
 245 {
 246         struct gnutar *gnutar;
 247         int ret;
 248
 249         gnutar = (struct gnutar *)a->format_data;
 250         ret = __archive_write_nulls(a, (size_t)
 251             (gnutar->entry_bytes_remaining + gnutar->entry_padding));
 252         gnutar->entry_bytes_remaining = gnutar->entry_padding = 0;
 253         return (ret);
 254 }
 255
 256 static ssize_t
 257 archive_write_gnutar_data(struct archive_write *a, const void *buff, size_t s)
 258 {
 259         struct gnutar *gnutar;
 260         int ret;
 261
 262         gnutar = (struct gnutar *)a->format_data;
 263         if (s > gnutar->entry_bytes_remaining)
 264                 s = (size_t)gnutar->entry_bytes_remaining;
 265         ret = __archive_write_output(a, buff, s);
 266         gnutar->entry_bytes_remaining -= s;
 267         if (ret != ARCHIVE_OK)
 268                 return (ret);
 269         return (s);
 270 }
 271
 272 static int
 273 archive_write_gnutar_header(struct archive_write *a,
 274      struct archive_entry *entry)
 275 {
 276         char buff[512];
 277         int r, ret, ret2 = ARCHIVE_OK;
 278         int tartype;
 279         struct gnutar *gnutar;
 280         struct archive_string_conv *sconv;
 281         struct archive_entry *entry_main;
 282
 283         gnutar = (struct gnutar *)a->format_data;
 284
 285         /* Setup default string conversion. */
 286         if (gnutar->opt_sconv == NULL) {
 287                 if (!gnutar->init_default_conversion) {
 288                         gnutar->sconv_default =
 289                             archive_string_default_conversion_for_write(
 290                                 &(a->archive));
 291                         gnutar->init_default_conversion = 1;
 292                 }
 293                 sconv = gnutar->sconv_default;
 294         } else
 295                 sconv = gnutar->opt_sconv;
 296
 297         /* Only regular files (not hardlinks) have data. */
 298         if (archive_entry_hardlink(entry) != NULL ||
 299             archive_entry_symlink(entry) != NULL ||
 300             !(archive_entry_filetype(entry) == AE_IFREG))
 301                 archive_entry_set_size(entry, 0);
 302
 303         if (AE_IFDIR == archive_entry_filetype(entry)) {
 304                 const char *p;
 305                 size_t path_length;
 306                 /*
 307                  * Ensure a trailing '/'.  Modify the entry so
 308                  * the client sees the change.
 309                  */
 310 #if defined(_WIN32) && !defined(__CYGWIN__)
 311                 const wchar_t *wp;
 312
 313                 wp = archive_entry_pathname_w(entry);
 314                 if (wp != NULL && wp[wcslen(wp) -1] != L'/') {
 315                         struct archive_wstring ws;
 316
 317                         archive_string_init(&ws);
 318                         path_length = wcslen(wp);
 319                         if (archive_wstring_ensure(&ws,
 320                             path_length + 2) == NULL) {
 321                                 archive_set_error(&a->archive, ENOMEM,
 322                                     "Can't allocate ustar data");
 323                                 archive_wstring_free(&ws);
 324                                 return(ARCHIVE_FATAL);
 325                         }
 326                         /* Should we keep '\' ? */
 327                         if (wp[path_length -1] == L'\\')
 328                                 path_length--;
 329                         archive_wstrncpy(&ws, wp, path_length);
 330                         archive_wstrappend_wchar(&ws, L'/');
 331                         archive_entry_copy_pathname_w(entry, ws.s);
 332                         archive_wstring_free(&ws);
 333                         p = NULL;
 334                 } else
 335 #endif
 336                         p = archive_entry_pathname(entry);
 337                 /*
 338                  * On Windows, this is a backup operation just in
 339                  * case getting WCS failed. On POSIX, this is a
 340                  * normal operation.
 341                  */
 342                 if (p != NULL && p[strlen(p) - 1] != '/') {
 343                         struct archive_string as;
 344
 345                         archive_string_init(&as);
 346                         path_length = strlen(p);
 347                         if (archive_string_ensure(&as,
 348                             path_length + 2) == NULL) {
 349                                 archive_set_error(&a->archive, ENOMEM,
 350                                     "Can't allocate ustar data");
 351                                 archive_string_free(&as);
 352                                 return(ARCHIVE_FATAL);
 353                         }
 354 #if defined(_WIN32) && !defined(__CYGWIN__)
 355                         /* NOTE: This might break the pathname
 356                          * if the current code page is CP932 and
 357                          * the pathname includes a character '\'
 358                          * as a part of its multibyte pathname. */
 359                         if (p[strlen(p) -1] == '\\')
 360                                 path_length--;
 361                         else
 362 #endif
 363                         archive_strncpy(&as, p, path_length);
 364                         archive_strappend_char(&as, '/');
 365                         archive_entry_copy_pathname(entry, as.s);
 366                         archive_string_free(&as);
 367                 }
 368         }
 369
 370 #if defined(_WIN32) && !defined(__CYGWIN__)
 371         /* Make sure the path separators in pahtname, hardlink and symlink
 372          * are all slash '/', not the Windows path separator '\'. */
 373         entry_main = __la_win_entry_in_posix_pathseparator(entry);
 374         if (entry_main == NULL) {
 375                 archive_set_error(&a->archive, ENOMEM,
 376                     "Can't allocate ustar data");
 377                 return(ARCHIVE_FATAL);
 378         }
 379         if (entry != entry_main)
 380                 entry = entry_main;
 381         else
 382                 entry_main = NULL;
 383 #else
 384         entry_main = NULL;
 385 #endif
 386         r = archive_entry_pathname_l(entry, &(gnutar->pathname),
 387             &(gnutar->pathname_length), sconv);
 388         if (r != 0) {
 389                 if (errno == ENOMEM) {
 390                         archive_set_error(&a->archive, ENOMEM,
 391                             "Can't allocate memory for Pathame");
 392                         ret = ARCHIVE_FATAL;
 393                         goto exit_write_header;
 394                 }
 395                 archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
 396                     "Can't translate pathname '%s' to %s",
 397                     archive_entry_pathname(entry),
 398                     archive_string_conversion_charset_name(sconv));
 399                 ret2 = ARCHIVE_WARN;
 400         }
 401         r = archive_entry_uname_l(entry, &(gnutar->uname),
 402             &(gnutar->uname_length), sconv);
 403         if (r != 0) {
 404                 if (errno == ENOMEM) {
 405                         archive_set_error(&a->archive, ENOMEM,
 406                             "Can't allocate memory for Uname");
 407                         ret = ARCHIVE_FATAL;
 408                         goto exit_write_header;
 409                 }
 410                 archive_set_error(&a->archive,
 411                     ARCHIVE_ERRNO_FILE_FORMAT,
 412                     "Can't translate uname '%s' to %s",
 413                     archive_entry_uname(entry),
 414                     archive_string_conversion_charset_name(sconv));
 415                 ret2 = ARCHIVE_WARN;
 416         }
 417         r = archive_entry_gname_l(entry, &(gnutar->gname),
 418             &(gnutar->gname_length), sconv);
 419         if (r != 0) {
 420                 if (errno == ENOMEM) {
 421                         archive_set_error(&a->archive, ENOMEM,
 422                             "Can't allocate memory for Gname");
 423                         ret = ARCHIVE_FATAL;
 424                         goto exit_write_header;
 425                 }
 426                 archive_set_error(&a->archive,
 427                     ARCHIVE_ERRNO_FILE_FORMAT,
 428                     "Can't translate gname '%s' to %s",
 429                     archive_entry_gname(entry),
 430                     archive_string_conversion_charset_name(sconv));
 431                 ret2 = ARCHIVE_WARN;
 432         }
 433
 434         /* If linkname is longer than 100 chars we need to add a 'K' header. */
 435         r = archive_entry_hardlink_l(entry, &(gnutar->linkname),
 436             &(gnutar->linkname_length), sconv);
 437         if (r != 0) {
 438                 if (errno == ENOMEM) {
 439                         archive_set_error(&a->archive, ENOMEM,
 440                             "Can't allocate memory for Linkname");
 441                         ret = ARCHIVE_FATAL;
 442                         goto exit_write_header;
 443                 }
 444                 archive_set_error(&a->archive,
 445                     ARCHIVE_ERRNO_FILE_FORMAT,
 446                     "Can't translate linkname '%s' to %s",
 447                     archive_entry_hardlink(entry),
 448                     archive_string_conversion_charset_name(sconv));
 449                 ret2 = ARCHIVE_WARN;
 450         }
 451         if (gnutar->linkname_length == 0) {
 452                 r = archive_entry_symlink_l(entry, &(gnutar->linkname),
 453                     &(gnutar->linkname_length), sconv);
 454                 if (r != 0) {
 455                         if (errno == ENOMEM) {
 456                                 archive_set_error(&a->archive, ENOMEM,
 457                                     "Can't allocate memory for Linkname");
 458                                 ret = ARCHIVE_FATAL;
 459                                 goto exit_write_header;
 460                         }
 461                         archive_set_error(&a->archive,
 462                             ARCHIVE_ERRNO_FILE_FORMAT,
 463                             "Can't translate linkname '%s' to %s",
 464                             archive_entry_hardlink(entry),
 465                             archive_string_conversion_charset_name(sconv));
 466                         ret2 = ARCHIVE_WARN;
 467                 }
 468         }
 469         if (gnutar->linkname_length > GNUTAR_linkname_size) {
 470                 size_t todo = gnutar->linkname_length;
 471                 struct archive_entry *temp = archive_entry_new2(&a->archive);
 472
 473                 /* Uname/gname here don't really matter since no one reads them;
 474                  * these are the values that GNU tar happens to use on FreeBSD. */
 475                 archive_entry_set_uname(temp, "root");
 476                 archive_entry_set_gname(temp, "wheel");
 477
 478                 archive_entry_set_pathname(temp, "././@LongLink");
 479                 archive_entry_set_size(temp, gnutar->linkname_length + 1);
 480                 ret = archive_format_gnutar_header(a, buff, temp, 'K');
 481                 if (ret < ARCHIVE_WARN)
 482                         goto exit_write_header;
 483                 ret = __archive_write_output(a, buff, 512);
 484                 if(ret < ARCHIVE_WARN)
 485                         goto exit_write_header;
 486                 archive_entry_free(temp);
 487                 /* Write as many 512 bytes blocks as needed to write full name. */
 488                 ret = __archive_write_output(a, gnutar->linkname, todo);
 489                 if(ret < ARCHIVE_WARN)
 490                         goto exit_write_header;
 491                 ret = __archive_write_nulls(a, 0x1ff & (-(ssize_t)todo));
 492                 if (ret < ARCHIVE_WARN)
 493                         goto exit_write_header;
 494         }
 495
 496         /* If pathname is longer than 100 chars we need to add an 'L' header. */
 497         if (gnutar->pathname_length > GNUTAR_name_size) {
 498                 const char *pathname = gnutar->pathname;
 499                 size_t todo = gnutar->pathname_length;
 500                 struct archive_entry *temp = archive_entry_new2(&a->archive);
 501
 502                 /* Uname/gname here don't really matter since no one reads them;
 503                  * these are the values that GNU tar happens to use on FreeBSD. */
 504                 archive_entry_set_uname(temp, "root");
 505                 archive_entry_set_gname(temp, "wheel");
 506
 507                 archive_entry_set_pathname(temp, "././@LongLink");
 508                 archive_entry_set_size(temp, gnutar->pathname_length + 1);
 509                 ret = archive_format_gnutar_header(a, buff, temp, 'L');
 510                 if (ret < ARCHIVE_WARN)
 511                         goto exit_write_header;
 512                 ret = __archive_write_output(a, buff, 512);
 513                 if(ret < ARCHIVE_WARN)
 514                         goto exit_write_header;
 515                 archive_entry_free(temp);
 516                 /* Write as many 512 bytes blocks as needed to write full name. */
 517                 ret = __archive_write_output(a, pathname, todo);
 518                 if(ret < ARCHIVE_WARN)
 519                         goto exit_write_header;
 520                 ret = __archive_write_nulls(a, 0x1ff & (-(ssize_t)todo));
 521                 if (ret < ARCHIVE_WARN)
 522                         goto exit_write_header;
 523         }
 524
 525         if (archive_entry_hardlink(entry) != NULL) {
 526                 tartype = '1';
 527         } else
 528                 switch (archive_entry_filetype(entry)) {
 529                 case AE_IFREG: tartype = '0' ; break;
 530                 case AE_IFLNK: tartype = '2' ; break;
 531                 case AE_IFCHR: tartype = '3' ; break;
 532                 case AE_IFBLK: tartype = '4' ; break;
 533                 case AE_IFDIR: tartype = '5' ; break;
 534                 case AE_IFIFO: tartype = '6' ; break;
 535                 case AE_IFSOCK:
 536                         archive_set_error(&a->archive,
 537                             ARCHIVE_ERRNO_FILE_FORMAT,
 538                             "tar format cannot archive socket");
 539                         ret = ARCHIVE_FAILED;
 540                         goto exit_write_header;
 541                 default:
 542                         archive_set_error(&a->archive,
 543                             ARCHIVE_ERRNO_FILE_FORMAT,
 544                             "tar format cannot archive this (mode=0%lo)",
 545                             (unsigned long)archive_entry_mode(entry));
 546                         ret = ARCHIVE_FAILED;
 547                         goto exit_write_header;
 548                 }
 549
 550         ret = archive_format_gnutar_header(a, buff, entry, tartype);
 551         if (ret < ARCHIVE_WARN)
 552                 goto exit_write_header;
 553         if (ret2 < ret)
 554                 ret = ret2;
 555         ret2 = __archive_write_output(a, buff, 512);
 556         if (ret2 < ARCHIVE_WARN) {
 557                 ret = ret2;
 558                 goto exit_write_header;
 559         }
 560         if (ret2 < ret)
 561                 ret = ret2;
 562
 563         gnutar->entry_bytes_remaining = archive_entry_size(entry);
 564         gnutar->entry_padding = 0x1ff & (-(int64_t)gnutar->entry_bytes_remaining);
 565 exit_write_header:
 566         if (entry_main)
 567                 archive_entry_free(entry_main);
 568         return (ret);
 569 }
 570
 571 static int
 572 archive_format_gnutar_header(struct archive_write *a, char h[512],
 573     struct archive_entry *entry, int tartype)
 574 {
 575         unsigned int checksum;
 576         int i, ret;
 577         size_t copy_length;
 578         const char *p;
 579         struct gnutar *gnutar;
 580
 581         gnutar = (struct gnutar *)a->format_data;
 582
 583         ret = 0;
 584
 585         /*
 586          * The "template header" already includes the signature,
 587          * various end-of-field markers, and other required elements.
 588          */
 589         memcpy(h, &template_header, 512);
 590
 591         /*
 592          * Because the block is already null-filled, and strings
 593          * are allowed to exactly fill their destination (without null),
 594          * I use memcpy(dest, src, strlen()) here a lot to copy strings.
 595          */
 596
 597         if (tartype == 'K' || tartype == 'L') {
 598                 p = archive_entry_pathname(entry);
 599                 copy_length = strlen(p);
 600         } else {
 601                 p = gnutar->pathname;
 602                 copy_length = gnutar->pathname_length;
 603         }
 604         if (copy_length > GNUTAR_name_size)
 605                 copy_length = GNUTAR_name_size;
 606         memcpy(h + GNUTAR_name_offset, p, copy_length);
 607
 608         if ((copy_length = gnutar->linkname_length) > 0) {
 609                 if (copy_length > GNUTAR_linkname_size)
 610                         copy_length = GNUTAR_linkname_size;
 611                 memcpy(h + GNUTAR_linkname_offset, gnutar->linkname,
 612                     copy_length);
 613         }
 614
 615         /* TODO: How does GNU tar handle unames longer than GNUTAR_uname_size? */
 616         if (tartype == 'K' || tartype == 'L') {
 617                 p = archive_entry_uname(entry);
 618                 copy_length = strlen(p);
 619         } else {
 620                 p = gnutar->uname;
 621                 copy_length = gnutar->uname_length;
 622         }
 623         if (copy_length > 0) {
 624                 if (copy_length > GNUTAR_uname_size)
 625                         copy_length = GNUTAR_uname_size;
 626                 memcpy(h + GNUTAR_uname_offset, p, copy_length);
 627         }
 628
 629         /* TODO: How does GNU tar handle gnames longer than GNUTAR_gname_size? */
 630         if (tartype == 'K' || tartype == 'L') {
 631                 p = archive_entry_gname(entry);
 632                 copy_length = strlen(p);
 633         } else {
 634                 p = gnutar->gname;
 635                 copy_length = gnutar->gname_length;
 636         }
 637         if (copy_length > 0) {
 638                 if (strlen(p) > GNUTAR_gname_size)
 639                         copy_length = GNUTAR_gname_size;
 640                 memcpy(h + GNUTAR_gname_offset, p, copy_length);
 641         }
 642
 643         /* By truncating the mode here, we ensure it always fits. */
 644         format_octal(archive_entry_mode(entry) & 07777,
 645             h + GNUTAR_mode_offset, GNUTAR_mode_size);
 646
 647         /* GNU tar supports base-256 here, so should never overflow. */
 648         if (format_number(archive_entry_uid(entry), h + GNUTAR_uid_offset,
 649                 GNUTAR_uid_size, GNUTAR_uid_max_size)) {
 650                 archive_set_error(&a->archive, ERANGE,
 651                     "Numeric user ID %jd too large",
 652                     (intmax_t)archive_entry_uid(entry));
 653                 ret = ARCHIVE_FAILED;
 654         }
 655
 656         /* GNU tar supports base-256 here, so should never overflow. */
 657         if (format_number(archive_entry_gid(entry), h + GNUTAR_gid_offset,
 658                 GNUTAR_gid_size, GNUTAR_gid_max_size)) {
 659                 archive_set_error(&a->archive, ERANGE,
 660                     "Numeric group ID %jd too large",
 661                     (intmax_t)archive_entry_gid(entry));
 662                 ret = ARCHIVE_FAILED;
 663         }
 664
 665         /* GNU tar supports base-256 here, so should never overflow. */
 666         if (format_number(archive_entry_size(entry), h + GNUTAR_size_offset,
 667                 GNUTAR_size_size, GNUTAR_size_max_size)) {
 668                 archive_set_error(&a->archive, ERANGE,
 669                     "File size out of range");
 670                 ret = ARCHIVE_FAILED;
 671         }
 672
 673         /* Shouldn't overflow before 2106, since mtime field is 33 bits. */
 674         format_octal(archive_entry_mtime(entry),
 675             h + GNUTAR_mtime_offset, GNUTAR_mtime_size);
 676
 677         if (archive_entry_filetype(entry) == AE_IFBLK
 678             || archive_entry_filetype(entry) == AE_IFCHR) {
 679                 if (format_octal(archive_entry_rdevmajor(entry),
 680                     h + GNUTAR_rdevmajor_offset,
 681                         GNUTAR_rdevmajor_size)) {
 682                         archive_set_error(&a->archive, ERANGE,
 683                             "Major device number too large");
 684                         ret = ARCHIVE_FAILED;
 685                 }
 686
 687                 if (format_octal(archive_entry_rdevminor(entry),
 688                     h + GNUTAR_rdevminor_offset,
 689                         GNUTAR_rdevminor_size)) {
 690                         archive_set_error(&a->archive, ERANGE,
 691                             "Minor device number too large");
 692                         ret = ARCHIVE_FAILED;
 693                 }
 694         }
 695
 696         h[GNUTAR_typeflag_offset] = tartype;
 697
 698         checksum = 0;
 699         for (i = 0; i < 512; i++)
 700                 checksum += 255 & (unsigned int)h[i];
 701         h[GNUTAR_checksum_offset + 6] = '\0'; /* Can't be pre-set in the template. */
 702         /* h[GNUTAR_checksum_offset + 7] = ' '; */ /* This is pre-set in the template. */
 703         format_octal(checksum, h + GNUTAR_checksum_offset, 6);
 704         return (ret);
 705 }
 706
 707 /*
 708  * Format a number into a field, falling back to base-256 if necessary.
 709  */
 710 static int
 711 format_number(int64_t v, char *p, int s, int maxsize)
 712 {
 713         int64_t limit = ((int64_t)1 << (s*3));
 714
 715         if (v < limit)
 716                 return (format_octal(v, p, s));
 717         return (format_256(v, p, maxsize));
 718 }
 719
 720 /*
 721  * Format a number into the specified field using base-256.
 722  */
 723 static int
 724 format_256(int64_t v, char *p, int s)
 725 {
 726         p += s;
 727         while (s-- > 0) {
 728                 *--p = (char)(v & 0xff);
 729                 v >>= 8;
 730         }
 731         *p |= 0x80; /* Set the base-256 marker bit. */
 732         return (0);
 733 }
 734
 735 /*
 736  * Format a number into the specified field using octal.
 737  */
 738 static int
 739 format_octal(int64_t v, char *p, int s)
 740 {
 741         int len = s;
 742
 743         /* Octal values can't be negative, so use 0. */
 744         if (v < 0)
 745                 v = 0;
 746
 747         p += s;         /* Start at the end and work backwards. */
 748         while (s-- > 0) {
 749                 *--p = (char)('0' + (v & 7));
 750                 v >>= 3;
 751         }
 752
 753         if (v == 0)
 754                 return (0);
 755
 756         /* If it overflowed, fill field with max value. */
 757         while (len-- > 0)
 758                 *p++ = '7';
 759
 760         return (-1);
 761 }