g10/compress-bz2.c

   1 /* compress.c - bzip2 compress filter
   2  * Copyright (C) 2003, 2004 Free Software Foundation, Inc.
   3  *
   4  * This file is part of GnuPG.
   5  *
   6  * GnuPG is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 3 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * GnuPG is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include <config.h>
  21 #include <string.h>
  22 #include <stdio.h> /* Early versions of bzlib (1.0) require stdio.h */
  23 #include <bzlib.h>
  24
  25 #include "gpg.h"
  26 #include "util.h"
  27 #include "packet.h"
  28 #include "filter.h"
  29 #include "main.h"
  30 #include "options.h"
  31
  32 /* Note that the code in compress.c is nearly identical to the code
  33    here, so if you fix a bug here, look there to see if a matching bug
  34    needs to be fixed.  I tried to have one set of functions that could
  35    do ZIP, ZLIB, and BZIP2, but it became dangerously unreadable with
  36    #ifdefs and if(algo) -dshaw */
  37
  38 static void
  39 init_compress( compress_filter_context_t *zfx, bz_stream *bzs )
  40 {
  41   int rc;
  42   int level;
  43
  44   if( opt.bz2_compress_level >= 1 && opt.bz2_compress_level <= 9 )
  45     level = opt.bz2_compress_level;
  46   else if( opt.bz2_compress_level == -1 )
  47     level = 6; /* no particular reason, but it seems reasonable */
  48   else
  49     {
  50       log_error("invalid compression level; using default level\n");
  51       level = 6;
  52     }
  53
  54   if((rc=BZ2_bzCompressInit(bzs,level,0,0))!=BZ_OK)
  55     log_fatal("bz2lib problem: %d\n",rc);
  56
  57   zfx->outbufsize = 8192;
  58   zfx->outbuf = xmalloc( zfx->outbufsize );
  59 }
  60
  61 static int
  62 do_compress(compress_filter_context_t *zfx, bz_stream *bzs, int flush, IOBUF a)
  63 {
  64   int rc;
  65   int zrc;
  66   unsigned n;
  67
  68   do
  69     {
  70       bzs->next_out = zfx->outbuf;
  71       bzs->avail_out = zfx->outbufsize;
  72       if( DBG_FILTER )
  73         log_debug("enter bzCompress: avail_in=%u, avail_out=%u, flush=%d\n",
  74                   (unsigned)bzs->avail_in, (unsigned)bzs->avail_out, flush );
  75       zrc = BZ2_bzCompress( bzs, flush );
  76       if( zrc == BZ_STREAM_END && flush == BZ_FINISH )
  77         ;
  78       else if( zrc != BZ_RUN_OK && zrc != BZ_FINISH_OK )
  79         log_fatal("bz2lib deflate problem: rc=%d\n", zrc );
  80
  81       n = zfx->outbufsize - bzs->avail_out;
  82       if( DBG_FILTER )
  83         log_debug("leave bzCompress:"
  84                   " avail_in=%u, avail_out=%u, n=%u, zrc=%d\n",
  85                   (unsigned)bzs->avail_in, (unsigned)bzs->avail_out,
  86                   (unsigned)n, zrc );
  87
  88       if( (rc=iobuf_write( a, zfx->outbuf, n )) )
  89         {
  90           log_debug("bzCompress: iobuf_write failed\n");
  91           return rc;
  92         }
  93     }
  94   while( bzs->avail_in || (flush == BZ_FINISH && zrc != BZ_STREAM_END) );
  95
  96   return 0;
  97 }
  98
  99 static void
 100 init_uncompress( compress_filter_context_t *zfx, bz_stream *bzs )
 101 {
 102   int rc;
 103
 104   if((rc=BZ2_bzDecompressInit(bzs,0,opt.bz2_decompress_lowmem))!=BZ_OK)
 105     log_fatal("bz2lib problem: %d\n",rc);
 106
 107   zfx->inbufsize = 2048;
 108   zfx->inbuf = xmalloc( zfx->inbufsize );
 109   bzs->avail_in = 0;
 110 }
 111
 112 static int
 113 do_uncompress( compress_filter_context_t *zfx, bz_stream *bzs,
 114                IOBUF a, size_t *ret_len )
 115 {
 116   int zrc;
 117   int rc=0;
 118   size_t n;
 119   int nread, count;
 120   int refill = !bzs->avail_in;
 121
 122   if( DBG_FILTER )
 123     log_debug("begin bzDecompress: avail_in=%u, avail_out=%u, inbuf=%u\n",
 124               (unsigned)bzs->avail_in, (unsigned)bzs->avail_out,
 125               (unsigned)zfx->inbufsize );
 126   do
 127     {
 128       if( bzs->avail_in < zfx->inbufsize && refill )
 129         {
 130           n = bzs->avail_in;
 131           if( !n )
 132             bzs->next_in = zfx->inbuf;
 133           count = zfx->inbufsize - n;
 134           nread = iobuf_read( a, zfx->inbuf + n, count );
 135           if( nread == -1 ) nread = 0;
 136           n += nread;
 137           bzs->avail_in = n;
 138         }
 139
 140       refill = 1;
 141
 142       if( DBG_FILTER )
 143         log_debug("enter bzDecompress: avail_in=%u, avail_out=%u\n",
 144                   (unsigned)bzs->avail_in, (unsigned)bzs->avail_out);
 145
 146       zrc=BZ2_bzDecompress(bzs);
 147       if( DBG_FILTER )
 148         log_debug("leave bzDecompress: avail_in=%u, avail_out=%u, zrc=%d\n",
 149                   (unsigned)bzs->avail_in, (unsigned)bzs->avail_out, zrc);
 150       if( zrc == BZ_STREAM_END )
 151         rc = -1; /* eof */
 152       else if( zrc != BZ_OK && zrc != BZ_PARAM_ERROR )
 153         log_fatal("bz2lib inflate problem: rc=%d\n", zrc );
 154     }
 155   while( bzs->avail_out && zrc != BZ_STREAM_END && zrc != BZ_PARAM_ERROR );
 156
 157   /* I'm not completely happy with the two uses of BZ_PARAM_ERROR
 158      here.  The corresponding zlib function is Z_BUF_ERROR, which
 159      covers a narrower scope than BZ_PARAM_ERROR. -dshaw */
 160
 161   *ret_len = zfx->outbufsize - bzs->avail_out;
 162   if( DBG_FILTER )
 163     log_debug("do_uncompress: returning %u bytes\n", (unsigned)*ret_len );
 164   return rc;
 165 }
 166
 167 int
 168 compress_filter_bz2( void *opaque, int control,
 169                      IOBUF a, byte *buf, size_t *ret_len)
 170 {
 171   size_t size = *ret_len;
 172   compress_filter_context_t *zfx = opaque;
 173   bz_stream *bzs = zfx->opaque;
 174   int rc=0;
 175
 176   if( control == IOBUFCTRL_UNDERFLOW )
 177     {
 178       if( !zfx->status )
 179         {
 180           bzs = zfx->opaque = xmalloc_clear( sizeof *bzs );
 181           init_uncompress( zfx, bzs );
 182           zfx->status = 1;
 183         }
 184
 185       bzs->next_out = buf;
 186       bzs->avail_out = size;
 187       zfx->outbufsize = size; /* needed only for calculation */
 188       rc = do_uncompress( zfx, bzs, a, ret_len );
 189     }
 190   else if( control == IOBUFCTRL_FLUSH )
 191     {
 192       if( !zfx->status )
 193         {
 194           PACKET pkt;
 195           PKT_compressed cd;
 196
 197           if( zfx->algo != COMPRESS_ALGO_BZIP2 )
 198             BUG();
 199           memset( &cd, 0, sizeof cd );
 200           cd.len = 0;
 201           cd.algorithm = zfx->algo;
 202           init_packet( &pkt );
 203           pkt.pkttype = PKT_COMPRESSED;
 204           pkt.pkt.compressed = &cd;
 205           if( build_packet( a, &pkt ))
 206             log_bug("build_packet(PKT_COMPRESSED) failed\n");
 207           bzs = zfx->opaque = xmalloc_clear( sizeof *bzs );
 208           init_compress( zfx, bzs );
 209           zfx->status = 2;
 210         }
 211
 212       bzs->next_in = buf;
 213       bzs->avail_in = size;
 214       rc = do_compress( zfx, bzs, BZ_RUN, a );
 215     }
 216   else if( control == IOBUFCTRL_FREE )
 217     {
 218       if( zfx->status == 1 )
 219         {
 220           BZ2_bzDecompressEnd(bzs);
 221           xfree(bzs);
 222           zfx->opaque = NULL;
 223           xfree(zfx->outbuf); zfx->outbuf = NULL;
 224         }
 225       else if( zfx->status == 2 )
 226         {
 227           bzs->next_in = buf;
 228           bzs->avail_in = 0;
 229           do_compress( zfx, bzs, BZ_FINISH, a );
 230           BZ2_bzCompressEnd(bzs);
 231           xfree(bzs);
 232           zfx->opaque = NULL;
 233           xfree(zfx->outbuf); zfx->outbuf = NULL;
 234         }
 235       if (zfx->release)
 236         zfx->release (zfx);
 237     }
 238   else if( control == IOBUFCTRL_DESC )
 239     *(char**)buf = "compress_filter";
 240   return rc;
 241 }