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 2 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, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
  19  * USA.
  20  */
  21
  22 #include <config.h>
  23 #include <string.h>
  24 #include <stdio.h> /* Early versions of bzlib (1.0) require stdio.h */
  25 #include <bzlib.h>
  26
  27 #include "gpg.h"
  28 #include "util.h"
  29 #include "packet.h"
  30 #include "filter.h"
  31 #include "main.h"
  32 #include "options.h"
  33
  34 /* Note that the code in compress.c is nearly identical to the code
  35    here, so if you fix a bug here, look there to see if a matching bug
  36    needs to be fixed.  I tried to have one set of functions that could
  37    do ZIP, ZLIB, and BZIP2, but it became dangerously unreadable with
  38    #ifdefs and if(algo) -dshaw */
  39
  40 static void
  41 init_compress( compress_filter_context_t *zfx, bz_stream *bzs )
  42 {
  43   int rc;
  44   int level;
  45
  46   if( opt.bz2_compress_level >= 1 && opt.bz2_compress_level <= 9 )
  47     level = opt.bz2_compress_level;
  48   else if( opt.bz2_compress_level == -1 )
  49     level = 6; /* no particular reason, but it seems reasonable */
  50   else
  51     {
  52       log_error("invalid compression level; using default level\n");
  53       level = 6;
  54     }
  55
  56   if((rc=BZ2_bzCompressInit(bzs,level,0,0))!=BZ_OK)
  57     log_fatal("bz2lib problem: %d\n",rc);
  58
  59   zfx->outbufsize = 8192;
  60   zfx->outbuf = xmalloc( zfx->outbufsize );
  61 }
  62
  63 static int
  64 do_compress(compress_filter_context_t *zfx, bz_stream *bzs, int flush, IOBUF a)
  65 {
  66   int rc;
  67   int zrc;
  68   unsigned n;
  69
  70   do
  71     {
  72       bzs->next_out = zfx->outbuf;
  73       bzs->avail_out = zfx->outbufsize;
  74       if( DBG_FILTER )
  75         log_debug("enter bzCompress: avail_in=%u, avail_out=%u, flush=%d\n",
  76                   (unsigned)bzs->avail_in, (unsigned)bzs->avail_out, flush );
  77       zrc = BZ2_bzCompress( bzs, flush );
  78       if( zrc == BZ_STREAM_END && flush == BZ_FINISH )
  79         ;
  80       else if( zrc != BZ_RUN_OK && zrc != BZ_FINISH_OK )
  81         log_fatal("bz2lib deflate problem: rc=%d\n", zrc );
  82
  83       n = zfx->outbufsize - bzs->avail_out;
  84       if( DBG_FILTER )
  85         log_debug("leave bzCompress:"
  86                   " avail_in=%u, avail_out=%u, n=%u, zrc=%d\n",
  87                   (unsigned)bzs->avail_in, (unsigned)bzs->avail_out,
  88                   (unsigned)n, zrc );
  89
  90       if( (rc=iobuf_write( a, zfx->outbuf, n )) )
  91         {
  92           log_debug("bzCompress: iobuf_write failed\n");
  93           return rc;
  94         }
  95     }
  96   while( bzs->avail_in || (flush == BZ_FINISH && zrc != BZ_STREAM_END) );
  97
  98   return 0;
  99 }
 100
 101 static void
 102 init_uncompress( compress_filter_context_t *zfx, bz_stream *bzs )
 103 {
 104   int rc;
 105
 106   if((rc=BZ2_bzDecompressInit(bzs,0,opt.bz2_decompress_lowmem))!=BZ_OK)
 107     log_fatal("bz2lib problem: %d\n",rc);
 108
 109   zfx->inbufsize = 2048;
 110   zfx->inbuf = xmalloc( zfx->inbufsize );
 111   bzs->avail_in = 0;
 112 }
 113
 114 static int
 115 do_uncompress( compress_filter_context_t *zfx, bz_stream *bzs,
 116                IOBUF a, size_t *ret_len )
 117 {
 118   int zrc;
 119   int rc=0;
 120   size_t n;
 121   int nread, count;
 122   int refill = !bzs->avail_in;
 123
 124   if( DBG_FILTER )
 125     log_debug("begin bzDecompress: avail_in=%u, avail_out=%u, inbuf=%u\n",
 126               (unsigned)bzs->avail_in, (unsigned)bzs->avail_out,
 127               (unsigned)zfx->inbufsize );
 128   do
 129     {
 130       if( bzs->avail_in < zfx->inbufsize && refill )
 131         {
 132           n = bzs->avail_in;
 133           if( !n )
 134             bzs->next_in = zfx->inbuf;
 135           count = zfx->inbufsize - n;
 136           nread = iobuf_read( a, zfx->inbuf + n, count );
 137           if( nread == -1 ) nread = 0;
 138           n += nread;
 139           bzs->avail_in = n;
 140         }
 141
 142       refill = 1;
 143
 144       if( DBG_FILTER )
 145         log_debug("enter bzDecompress: avail_in=%u, avail_out=%u\n",
 146                   (unsigned)bzs->avail_in, (unsigned)bzs->avail_out);
 147
 148       zrc=BZ2_bzDecompress(bzs);
 149       if( DBG_FILTER )
 150         log_debug("leave bzDecompress: avail_in=%u, avail_out=%u, zrc=%d\n",
 151                   (unsigned)bzs->avail_in, (unsigned)bzs->avail_out, zrc);
 152       if( zrc == BZ_STREAM_END )
 153         rc = -1; /* eof */
 154       else if( zrc != BZ_OK && zrc != BZ_PARAM_ERROR )
 155         log_fatal("bz2lib inflate problem: rc=%d\n", zrc );
 156     }
 157   while( bzs->avail_out && zrc != BZ_STREAM_END && zrc != BZ_PARAM_ERROR );
 158
 159   /* I'm not completely happy with the two uses of BZ_PARAM_ERROR
 160      here.  The corresponding zlib function is Z_BUF_ERROR, which
 161      covers a narrower scope than BZ_PARAM_ERROR. -dshaw */
 162
 163   *ret_len = zfx->outbufsize - bzs->avail_out;
 164   if( DBG_FILTER )
 165     log_debug("do_uncompress: returning %u bytes\n", (unsigned)*ret_len );
 166   return rc;
 167 }
 168
 169 int
 170 compress_filter_bz2( void *opaque, int control,
 171                      IOBUF a, byte *buf, size_t *ret_len)
 172 {
 173   size_t size = *ret_len;
 174   compress_filter_context_t *zfx = opaque;
 175   bz_stream *bzs = zfx->opaque;
 176   int rc=0;
 177
 178   if( control == IOBUFCTRL_UNDERFLOW )
 179     {
 180       if( !zfx->status )
 181         {
 182           bzs = zfx->opaque = xmalloc_clear( sizeof *bzs );
 183           init_uncompress( zfx, bzs );
 184           zfx->status = 1;
 185         }
 186
 187       bzs->next_out = buf;
 188       bzs->avail_out = size;
 189       zfx->outbufsize = size; /* needed only for calculation */
 190       rc = do_uncompress( zfx, bzs, a, ret_len );
 191     }
 192   else if( control == IOBUFCTRL_FLUSH )
 193     {
 194       if( !zfx->status )
 195         {
 196           PACKET pkt;
 197           PKT_compressed cd;
 198
 199           if( zfx->algo != COMPRESS_ALGO_BZIP2 )
 200             BUG();
 201           memset( &cd, 0, sizeof cd );
 202           cd.len = 0;
 203           cd.algorithm = zfx->algo;
 204           init_packet( &pkt );
 205           pkt.pkttype = PKT_COMPRESSED;
 206           pkt.pkt.compressed = &cd;
 207           if( build_packet( a, &pkt ))
 208             log_bug("build_packet(PKT_COMPRESSED) failed\n");
 209           bzs = zfx->opaque = xmalloc_clear( sizeof *bzs );
 210           init_compress( zfx, bzs );
 211           zfx->status = 2;
 212         }
 213
 214       bzs->next_in = buf;
 215       bzs->avail_in = size;
 216       rc = do_compress( zfx, bzs, BZ_RUN, a );
 217     }
 218   else if( control == IOBUFCTRL_FREE )
 219     {
 220       if( zfx->status == 1 )
 221         {
 222           BZ2_bzDecompressEnd(bzs);
 223           xfree(bzs);
 224           zfx->opaque = NULL;
 225           xfree(zfx->outbuf); zfx->outbuf = NULL;
 226         }
 227       else if( zfx->status == 2 )
 228         {
 229           bzs->next_in = buf;
 230           bzs->avail_in = 0;
 231           do_compress( zfx, bzs, BZ_FINISH, a );
 232           BZ2_bzCompressEnd(bzs);
 233           xfree(bzs);
 234           zfx->opaque = NULL;
 235           xfree(zfx->outbuf); zfx->outbuf = NULL;
 236         }
 237       if (zfx->release)
 238         zfx->release (zfx);
 239     }
 240   else if( control == IOBUFCTRL_DESC )
 241     *(char**)buf = "compress_filter";
 242   return rc;
 243 }