contrib/libarchive/libarchive/archive_write.c

   1 /*-
   2  * Copyright (c) 2003-2010 Tim Kientzle
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
  15  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  16  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  17  * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
  18  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  19  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  20  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  21  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  23  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 #include "archive_platform.h"
  27 __FBSDID("$FreeBSD$");
  28
  29 /*
  30  * This file contains the "essential" portions of the write API, that
  31  * is, stuff that will essentially always be used by any client that
  32  * actually needs to write an archive.  Optional pieces have been, as
  33  * far as possible, separated out into separate files to reduce
  34  * needlessly bloating statically-linked clients.
  35  */
  36
  37 #ifdef HAVE_SYS_WAIT_H
  38 #include <sys/wait.h>
  39 #endif
  40 #ifdef HAVE_ERRNO_H
  41 #include <errno.h>
  42 #endif
  43 #ifdef HAVE_LIMITS_H
  44 #include <limits.h>
  45 #endif
  46 #include <stdio.h>
  47 #ifdef HAVE_STDLIB_H
  48 #include <stdlib.h>
  49 #endif
  50 #ifdef HAVE_STRING_H
  51 #include <string.h>
  52 #endif
  53 #include <time.h>
  54 #ifdef HAVE_UNISTD_H
  55 #include <unistd.h>
  56 #endif
  57
  58 #include "archive.h"
  59 #include "archive_entry.h"
  60 #include "archive_private.h"
  61 #include "archive_write_private.h"
  62
  63 static struct archive_vtable *archive_write_vtable(void);
  64
  65 static int      _archive_filter_code(struct archive *, int);
  66 static const char *_archive_filter_name(struct archive *, int);
  67 static int64_t  _archive_filter_bytes(struct archive *, int);
  68 static int  _archive_write_filter_count(struct archive *);
  69 static int      _archive_write_close(struct archive *);
  70 static int      _archive_write_free(struct archive *);
  71 static int      _archive_write_header(struct archive *, struct archive_entry *);
  72 static int      _archive_write_finish_entry(struct archive *);
  73 static ssize_t  _archive_write_data(struct archive *, const void *, size_t);
  74
  75 struct archive_none {
  76         size_t buffer_size;
  77         size_t avail;
  78         char *buffer;
  79         char *next;
  80 };
  81
  82 static struct archive_vtable *
  83 archive_write_vtable(void)
  84 {
  85         static struct archive_vtable av;
  86         static int inited = 0;
  87
  88         if (!inited) {
  89                 av.archive_close = _archive_write_close;
  90                 av.archive_filter_bytes = _archive_filter_bytes;
  91                 av.archive_filter_code = _archive_filter_code;
  92                 av.archive_filter_name = _archive_filter_name;
  93                 av.archive_filter_count = _archive_write_filter_count;
  94                 av.archive_free = _archive_write_free;
  95                 av.archive_write_header = _archive_write_header;
  96                 av.archive_write_finish_entry = _archive_write_finish_entry;
  97                 av.archive_write_data = _archive_write_data;
  98                 inited = 1;
  99         }
 100         return (&av);
 101 }
 102
 103 /*
 104  * Allocate, initialize and return an archive object.
 105  */
 106 struct archive *
 107 archive_write_new(void)
 108 {
 109         struct archive_write *a;
 110         unsigned char *nulls;
 111
 112         a = (struct archive_write *)malloc(sizeof(*a));
 113         if (a == NULL)
 114                 return (NULL);
 115         memset(a, 0, sizeof(*a));
 116         a->archive.magic = ARCHIVE_WRITE_MAGIC;
 117         a->archive.state = ARCHIVE_STATE_NEW;
 118         a->archive.vtable = archive_write_vtable();
 119         /*
 120          * The value 10240 here matches the traditional tar default,
 121          * but is otherwise arbitrary.
 122          * TODO: Set the default block size from the format selected.
 123          */
 124         a->bytes_per_block = 10240;
 125         a->bytes_in_last_block = -1;    /* Default */
 126
 127         /* Initialize a block of nulls for padding purposes. */
 128         a->null_length = 1024;
 129         nulls = (unsigned char *)malloc(a->null_length);
 130         if (nulls == NULL) {
 131                 free(a);
 132                 return (NULL);
 133         }
 134         memset(nulls, 0, a->null_length);
 135         a->nulls = nulls;
 136         return (&a->archive);
 137 }
 138
 139 /*
 140  * Set the block size.  Returns 0 if successful.
 141  */
 142 int
 143 archive_write_set_bytes_per_block(struct archive *_a, int bytes_per_block)
 144 {
 145         struct archive_write *a = (struct archive_write *)_a;
 146         archive_check_magic(&a->archive, ARCHIVE_WRITE_MAGIC,
 147             ARCHIVE_STATE_NEW, "archive_write_set_bytes_per_block");
 148         a->bytes_per_block = bytes_per_block;
 149         return (ARCHIVE_OK);
 150 }
 151
 152 /*
 153  * Get the current block size.  -1 if it has never been set.
 154  */
 155 int
 156 archive_write_get_bytes_per_block(struct archive *_a)
 157 {
 158         struct archive_write *a = (struct archive_write *)_a;
 159         archive_check_magic(&a->archive, ARCHIVE_WRITE_MAGIC,
 160             ARCHIVE_STATE_ANY, "archive_write_get_bytes_per_block");
 161         return (a->bytes_per_block);
 162 }
 163
 164 /*
 165  * Set the size for the last block.
 166  * Returns 0 if successful.
 167  */
 168 int
 169 archive_write_set_bytes_in_last_block(struct archive *_a, int bytes)
 170 {
 171         struct archive_write *a = (struct archive_write *)_a;
 172         archive_check_magic(&a->archive, ARCHIVE_WRITE_MAGIC,
 173             ARCHIVE_STATE_ANY, "archive_write_set_bytes_in_last_block");
 174         a->bytes_in_last_block = bytes;
 175         return (ARCHIVE_OK);
 176 }
 177
 178 /*
 179  * Return the value set above.  -1 indicates it has not been set.
 180  */
 181 int
 182 archive_write_get_bytes_in_last_block(struct archive *_a)
 183 {
 184         struct archive_write *a = (struct archive_write *)_a;
 185         archive_check_magic(&a->archive, ARCHIVE_WRITE_MAGIC,
 186             ARCHIVE_STATE_ANY, "archive_write_get_bytes_in_last_block");
 187         return (a->bytes_in_last_block);
 188 }
 189
 190 /*
 191  * dev/ino of a file to be rejected.  Used to prevent adding
 192  * an archive to itself recursively.
 193  */
 194 int
 195 archive_write_set_skip_file(struct archive *_a, int64_t d, int64_t i)
 196 {
 197         struct archive_write *a = (struct archive_write *)_a;
 198         archive_check_magic(&a->archive, ARCHIVE_WRITE_MAGIC,
 199             ARCHIVE_STATE_ANY, "archive_write_set_skip_file");
 200         a->skip_file_set = 1;
 201         a->skip_file_dev = d;
 202         a->skip_file_ino = i;
 203         return (ARCHIVE_OK);
 204 }
 205
 206 /*
 207  * Allocate and return the next filter structure.
 208  */
 209 struct archive_write_filter *
 210 __archive_write_allocate_filter(struct archive *_a)
 211 {
 212         struct archive_write *a = (struct archive_write *)_a;
 213         struct archive_write_filter *f;
 214
 215         f = calloc(1, sizeof(*f));
 216         f->archive = _a;
 217         if (a->filter_first == NULL)
 218                 a->filter_first = f;
 219         else
 220                 a->filter_last->next_filter = f;
 221         a->filter_last = f;
 222         return f;
 223 }
 224
 225 /*
 226  * Write data to a particular filter.
 227  */
 228 int
 229 __archive_write_filter(struct archive_write_filter *f,
 230     const void *buff, size_t length)
 231 {
 232         int r;
 233         if (length == 0)
 234                 return(ARCHIVE_OK);
 235         if (f->write == NULL)
 236                 /* If unset, a fatal error has already ocuured, so this filter
 237                  * didn't open. We cannot write anything. */
 238                 return(ARCHIVE_FATAL);
 239         r = (f->write)(f, buff, length);
 240         f->bytes_written += length;
 241         return (r);
 242 }
 243
 244 /*
 245  * Open a filter.
 246  */
 247 int
 248 __archive_write_open_filter(struct archive_write_filter *f)
 249 {
 250         if (f->open == NULL)
 251                 return (ARCHIVE_OK);
 252         return (f->open)(f);
 253 }
 254
 255 /*
 256  * Close a filter.
 257  */
 258 int
 259 __archive_write_close_filter(struct archive_write_filter *f)
 260 {
 261         if (f->close != NULL)
 262                 return (f->close)(f);
 263         if (f->next_filter != NULL)
 264                 return (__archive_write_close_filter(f->next_filter));
 265         return (ARCHIVE_OK);
 266 }
 267
 268 int
 269 __archive_write_output(struct archive_write *a, const void *buff, size_t length)
 270 {
 271         return (__archive_write_filter(a->filter_first, buff, length));
 272 }
 273
 274 int
 275 __archive_write_nulls(struct archive_write *a, size_t length)
 276 {
 277         if (length == 0)
 278                 return (ARCHIVE_OK);
 279
 280         while (length > 0) {
 281                 size_t to_write = length < a->null_length ? length : a->null_length;
 282                 int r = __archive_write_output(a, a->nulls, to_write);
 283                 if (r < ARCHIVE_OK)
 284                         return (r);
 285                 length -= to_write;
 286         }
 287         return (ARCHIVE_OK);
 288 }
 289
 290 static int
 291 archive_write_client_open(struct archive_write_filter *f)
 292 {
 293         struct archive_write *a = (struct archive_write *)f->archive;
 294         struct archive_none *state;
 295         void *buffer;
 296         size_t buffer_size;
 297
 298         f->bytes_per_block = archive_write_get_bytes_per_block(f->archive);
 299         f->bytes_in_last_block =
 300             archive_write_get_bytes_in_last_block(f->archive);
 301         buffer_size = f->bytes_per_block;
 302
 303         state = (struct archive_none *)calloc(1, sizeof(*state));
 304         buffer = (char *)malloc(buffer_size);
 305         if (state == NULL || buffer == NULL) {
 306                 free(state);
 307                 free(buffer);
 308                 archive_set_error(f->archive, ENOMEM,
 309                     "Can't allocate data for output buffering");
 310                 return (ARCHIVE_FATAL);
 311         }
 312
 313         state->buffer_size = buffer_size;
 314         state->buffer = buffer;
 315         state->next = state->buffer;
 316         state->avail = state->buffer_size;
 317         f->data = state;
 318
 319         if (a->client_opener == NULL)
 320                 return (ARCHIVE_OK);
 321         return (a->client_opener(f->archive, a->client_data));
 322 }
 323
 324 static int
 325 archive_write_client_write(struct archive_write_filter *f,
 326     const void *_buff, size_t length)
 327 {
 328         struct archive_write *a = (struct archive_write *)f->archive;
 329         struct archive_none *state = (struct archive_none *)f->data;
 330         const char *buff = (const char *)_buff;
 331         ssize_t remaining, to_copy;
 332         ssize_t bytes_written;
 333
 334         remaining = length;
 335
 336         /*
 337          * If there is no buffer for blocking, just pass the data
 338          * straight through to the client write callback.  In
 339          * particular, this supports "no write delay" operation for
 340          * special applications.  Just set the block size to zero.
 341          */
 342         if (state->buffer_size == 0) {
 343                 while (remaining > 0) {
 344                         bytes_written = (a->client_writer)(&a->archive,
 345                             a->client_data, buff, remaining);
 346                         if (bytes_written <= 0)
 347                                 return (ARCHIVE_FATAL);
 348                         remaining -= bytes_written;
 349                         buff += bytes_written;
 350                 }
 351                 return (ARCHIVE_OK);
 352         }
 353
 354         /* If the copy buffer isn't empty, try to fill it. */
 355         if (state->avail < state->buffer_size) {
 356                 /* If buffer is not empty... */
 357                 /* ... copy data into buffer ... */
 358                 to_copy = ((size_t)remaining > state->avail) ?
 359                         state->avail : (size_t)remaining;
 360                 memcpy(state->next, buff, to_copy);
 361                 state->next += to_copy;
 362                 state->avail -= to_copy;
 363                 buff += to_copy;
 364                 remaining -= to_copy;
 365                 /* ... if it's full, write it out. */
 366                 if (state->avail == 0) {
 367                         char *p = state->buffer;
 368                         size_t to_write = state->buffer_size;
 369                         while (to_write > 0) {
 370                                 bytes_written = (a->client_writer)(&a->archive,
 371                                     a->client_data, p, to_write);
 372                                 if (bytes_written <= 0)
 373                                         return (ARCHIVE_FATAL);
 374                                 if ((size_t)bytes_written > to_write) {
 375                                         archive_set_error(&(a->archive),
 376                                             -1, "write overrun");
 377                                         return (ARCHIVE_FATAL);
 378                                 }
 379                                 p += bytes_written;
 380                                 to_write -= bytes_written;
 381                         }
 382                         state->next = state->buffer;
 383                         state->avail = state->buffer_size;
 384                 }
 385         }
 386
 387         while ((size_t)remaining >= state->buffer_size) {
 388                 /* Write out full blocks directly to client. */
 389                 bytes_written = (a->client_writer)(&a->archive,
 390                     a->client_data, buff, state->buffer_size);
 391                 if (bytes_written <= 0)
 392                         return (ARCHIVE_FATAL);
 393                 buff += bytes_written;
 394                 remaining -= bytes_written;
 395         }
 396
 397         if (remaining > 0) {
 398                 /* Copy last bit into copy buffer. */
 399                 memcpy(state->next, buff, remaining);
 400                 state->next += remaining;
 401                 state->avail -= remaining;
 402         }
 403         return (ARCHIVE_OK);
 404 }
 405
 406 static int
 407 archive_write_client_close(struct archive_write_filter *f)
 408 {
 409         struct archive_write *a = (struct archive_write *)f->archive;
 410         struct archive_none *state = (struct archive_none *)f->data;
 411         ssize_t block_length;
 412         ssize_t target_block_length;
 413         ssize_t bytes_written;
 414         int ret = ARCHIVE_OK;
 415
 416         /* If there's pending data, pad and write the last block */
 417         if (state->next != state->buffer) {
 418                 block_length = state->buffer_size - state->avail;
 419
 420                 /* Tricky calculation to determine size of last block */
 421                 if (a->bytes_in_last_block <= 0)
 422                         /* Default or Zero: pad to full block */
 423                         target_block_length = a->bytes_per_block;
 424                 else
 425                         /* Round to next multiple of bytes_in_last_block. */
 426                         target_block_length = a->bytes_in_last_block *
 427                             ( (block_length + a->bytes_in_last_block - 1) /
 428                                 a->bytes_in_last_block);
 429                 if (target_block_length > a->bytes_per_block)
 430                         target_block_length = a->bytes_per_block;
 431                 if (block_length < target_block_length) {
 432                         memset(state->next, 0,
 433                             target_block_length - block_length);
 434                         block_length = target_block_length;
 435                 }
 436                 bytes_written = (a->client_writer)(&a->archive,
 437                     a->client_data, state->buffer, block_length);
 438                 ret = bytes_written <= 0 ? ARCHIVE_FATAL : ARCHIVE_OK;
 439         }
 440         if (a->client_closer)
 441                 (*a->client_closer)(&a->archive, a->client_data);
 442         free(state->buffer);
 443         free(state);
 444         /* Clear the close handler myself not to be called again. */
 445         f->close = NULL;
 446         a->client_data = NULL;
 447         /* Clear passphrase. */
 448         if (a->passphrase != NULL) {
 449                 memset(a->passphrase, 0, strlen(a->passphrase));
 450                 free(a->passphrase);
 451                 a->passphrase = NULL;
 452         }
 453         return (ret);
 454 }
 455
 456 /*
 457  * Open the archive using the current settings.
 458  */
 459 int
 460 archive_write_open(struct archive *_a, void *client_data,
 461     archive_open_callback *opener, archive_write_callback *writer,
 462     archive_close_callback *closer)
 463 {
 464         struct archive_write *a = (struct archive_write *)_a;
 465         struct archive_write_filter *client_filter;
 466         int ret, r1;
 467
 468         archive_check_magic(&a->archive, ARCHIVE_WRITE_MAGIC,
 469             ARCHIVE_STATE_NEW, "archive_write_open");
 470         archive_clear_error(&a->archive);
 471
 472         a->client_writer = writer;
 473         a->client_opener = opener;
 474         a->client_closer = closer;
 475         a->client_data = client_data;
 476
 477         client_filter = __archive_write_allocate_filter(_a);
 478         client_filter->open = archive_write_client_open;
 479         client_filter->write = archive_write_client_write;
 480         client_filter->close = archive_write_client_close;
 481
 482         ret = __archive_write_open_filter(a->filter_first);
 483         if (ret < ARCHIVE_WARN) {
 484                 r1 = __archive_write_close_filter(a->filter_first);
 485                 return (r1 < ret ? r1 : ret);
 486         }
 487
 488         a->archive.state = ARCHIVE_STATE_HEADER;
 489         if (a->format_init)
 490                 ret = (a->format_init)(a);
 491         return (ret);
 492 }
 493
 494 /*
 495  * Close out the archive.
 496  */
 497 static int
 498 _archive_write_close(struct archive *_a)
 499 {
 500         struct archive_write *a = (struct archive_write *)_a;
 501         int r = ARCHIVE_OK, r1 = ARCHIVE_OK;
 502
 503         archive_check_magic(&a->archive, ARCHIVE_WRITE_MAGIC,
 504             ARCHIVE_STATE_ANY | ARCHIVE_STATE_FATAL,
 505             "archive_write_close");
 506         if (a->archive.state == ARCHIVE_STATE_NEW
 507             || a->archive.state == ARCHIVE_STATE_CLOSED)
 508                 return (ARCHIVE_OK); /* Okay to close() when not open. */
 509
 510         archive_clear_error(&a->archive);
 511
 512         /* Finish the last entry if a finish callback is specified */
 513         if (a->archive.state == ARCHIVE_STATE_DATA
 514             && a->format_finish_entry != NULL)
 515                 r = ((a->format_finish_entry)(a));
 516
 517         /* Finish off the archive. */
 518         /* TODO: have format closers invoke compression close. */
 519         if (a->format_close != NULL) {
 520                 r1 = (a->format_close)(a);
 521                 if (r1 < r)
 522                         r = r1;
 523         }
 524
 525         /* Finish the compression and close the stream. */
 526         r1 = __archive_write_close_filter(a->filter_first);
 527         if (r1 < r)
 528                 r = r1;
 529
 530         if (a->archive.state != ARCHIVE_STATE_FATAL)
 531                 a->archive.state = ARCHIVE_STATE_CLOSED;
 532         return (r);
 533 }
 534
 535 static int
 536 _archive_write_filter_count(struct archive *_a)
 537 {
 538         struct archive_write *a = (struct archive_write *)_a;
 539         struct archive_write_filter *p = a->filter_first;
 540         int count = 0;
 541         while(p) {
 542                 count++;
 543                 p = p->next_filter;
 544         }
 545         return count;
 546 }
 547
 548 void
 549 __archive_write_filters_free(struct archive *_a)
 550 {
 551         struct archive_write *a = (struct archive_write *)_a;
 552         int r = ARCHIVE_OK, r1;
 553
 554         while (a->filter_first != NULL) {
 555                 struct archive_write_filter *next
 556                     = a->filter_first->next_filter;
 557                 if (a->filter_first->free != NULL) {
 558                         r1 = (*a->filter_first->free)(a->filter_first);
 559                         if (r > r1)
 560                                 r = r1;
 561                 }
 562                 free(a->filter_first);
 563                 a->filter_first = next;
 564         }
 565         a->filter_last = NULL;
 566 }
 567
 568 /*
 569  * Destroy the archive structure.
 570  *
 571  * Be careful: user might just call write_new and then write_free.
 572  * Don't assume we actually wrote anything or performed any non-trivial
 573  * initialization.
 574  */
 575 static int
 576 _archive_write_free(struct archive *_a)
 577 {
 578         struct archive_write *a = (struct archive_write *)_a;
 579         int r = ARCHIVE_OK, r1;
 580
 581         if (_a == NULL)
 582                 return (ARCHIVE_OK);
 583         /* It is okay to call free() in state FATAL. */
 584         archive_check_magic(&a->archive, ARCHIVE_WRITE_MAGIC,
 585             ARCHIVE_STATE_ANY | ARCHIVE_STATE_FATAL, "archive_write_free");
 586         if (a->archive.state != ARCHIVE_STATE_FATAL)
 587                 r = archive_write_close(&a->archive);
 588
 589         /* Release format resources. */
 590         if (a->format_free != NULL) {
 591                 r1 = (a->format_free)(a);
 592                 if (r1 < r)
 593                         r = r1;
 594         }
 595
 596         __archive_write_filters_free(_a);
 597
 598         /* Release various dynamic buffers. */
 599         free((void *)(uintptr_t)(const void *)a->nulls);
 600         archive_string_free(&a->archive.error_string);
 601         if (a->passphrase != NULL) {
 602                 /* A passphrase should be cleaned. */
 603                 memset(a->passphrase, 0, strlen(a->passphrase));
 604                 free(a->passphrase);
 605         }
 606         a->archive.magic = 0;
 607         __archive_clean(&a->archive);
 608         free(a);
 609         return (r);
 610 }
 611
 612 /*
 613  * Write the appropriate header.
 614  */
 615 static int
 616 _archive_write_header(struct archive *_a, struct archive_entry *entry)
 617 {
 618         struct archive_write *a = (struct archive_write *)_a;
 619         int ret, r2;
 620
 621         archive_check_magic(&a->archive, ARCHIVE_WRITE_MAGIC,
 622             ARCHIVE_STATE_DATA | ARCHIVE_STATE_HEADER, "archive_write_header");
 623         archive_clear_error(&a->archive);
 624
 625         if (a->format_write_header == NULL) {
 626                 archive_set_error(&(a->archive), -1,
 627                     "Format must be set before you can write to an archive.");
 628                 a->archive.state = ARCHIVE_STATE_FATAL;
 629                 return (ARCHIVE_FATAL);
 630         }
 631
 632         /* In particular, "retry" and "fatal" get returned immediately. */
 633         ret = archive_write_finish_entry(&a->archive);
 634         if (ret == ARCHIVE_FATAL) {
 635                 a->archive.state = ARCHIVE_STATE_FATAL;
 636                 return (ARCHIVE_FATAL);
 637         }
 638         if (ret < ARCHIVE_OK && ret != ARCHIVE_WARN)
 639                 return (ret);
 640
 641         if (a->skip_file_set &&
 642             archive_entry_dev_is_set(entry) &&
 643             archive_entry_ino_is_set(entry) &&
 644             archive_entry_dev(entry) == (dev_t)a->skip_file_dev &&
 645             archive_entry_ino64(entry) == a->skip_file_ino) {
 646                 archive_set_error(&a->archive, 0,
 647                     "Can't add archive to itself");
 648                 return (ARCHIVE_FAILED);
 649         }
 650
 651         /* Format and write header. */
 652         r2 = ((a->format_write_header)(a, entry));
 653         if (r2 == ARCHIVE_FAILED) {
 654                 return (ARCHIVE_FAILED);
 655         }
 656         if (r2 == ARCHIVE_FATAL) {
 657                 a->archive.state = ARCHIVE_STATE_FATAL;
 658                 return (ARCHIVE_FATAL);
 659         }
 660         if (r2 < ret)
 661                 ret = r2;
 662
 663         a->archive.state = ARCHIVE_STATE_DATA;
 664         return (ret);
 665 }
 666
 667 static int
 668 _archive_write_finish_entry(struct archive *_a)
 669 {
 670         struct archive_write *a = (struct archive_write *)_a;
 671         int ret = ARCHIVE_OK;
 672
 673         archive_check_magic(&a->archive, ARCHIVE_WRITE_MAGIC,
 674             ARCHIVE_STATE_HEADER | ARCHIVE_STATE_DATA,
 675             "archive_write_finish_entry");
 676         if (a->archive.state & ARCHIVE_STATE_DATA
 677             && a->format_finish_entry != NULL)
 678                 ret = (a->format_finish_entry)(a);
 679         a->archive.state = ARCHIVE_STATE_HEADER;
 680         return (ret);
 681 }
 682
 683 /*
 684  * Note that the compressor is responsible for blocking.
 685  */
 686 static ssize_t
 687 _archive_write_data(struct archive *_a, const void *buff, size_t s)
 688 {
 689         struct archive_write *a = (struct archive_write *)_a;
 690         const size_t max_write = INT_MAX;
 691
 692         archive_check_magic(&a->archive, ARCHIVE_WRITE_MAGIC,
 693             ARCHIVE_STATE_DATA, "archive_write_data");
 694         /* In particular, this catches attempts to pass negative values. */
 695         if (s > max_write)
 696                 s = max_write;
 697         archive_clear_error(&a->archive);
 698         return ((a->format_write_data)(a, buff, s));
 699 }
 700
 701 static struct archive_write_filter *
 702 filter_lookup(struct archive *_a, int n)
 703 {
 704         struct archive_write *a = (struct archive_write *)_a;
 705         struct archive_write_filter *f = a->filter_first;
 706         if (n == -1)
 707                 return a->filter_last;
 708         if (n < 0)
 709                 return NULL;
 710         while (n > 0 && f != NULL) {
 711                 f = f->next_filter;
 712                 --n;
 713         }
 714         return f;
 715 }
 716
 717 static int
 718 _archive_filter_code(struct archive *_a, int n)
 719 {
 720         struct archive_write_filter *f = filter_lookup(_a, n);
 721         return f == NULL ? -1 : f->code;
 722 }
 723
 724 static const char *
 725 _archive_filter_name(struct archive *_a, int n)
 726 {
 727         struct archive_write_filter *f = filter_lookup(_a, n);
 728         return f != NULL ? f->name : NULL;
 729 }
 730
 731 static int64_t
 732 _archive_filter_bytes(struct archive *_a, int n)
 733 {
 734         struct archive_write_filter *f = filter_lookup(_a, n);
 735         return f == NULL ? -1 : f->bytes_written;
 736 }