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   int eofseen = 0;
 122
 123   if( DBG_FILTER )
 124     log_debug("begin bzDecompress: avail_in=%u, avail_out=%u, inbuf=%u\n",
 125               (unsigned)bzs->avail_in, (unsigned)bzs->avail_out,
 126               (unsigned)zfx->inbufsize );
 127   do
 128     {
 129       if( bzs->avail_in < zfx->inbufsize && refill )
 130         {
 131           n = bzs->avail_in;
 132           if( !n )
 133             bzs->next_in = zfx->inbuf;
 134           count = zfx->inbufsize - n;
 135           nread = iobuf_read( a, zfx->inbuf + n, count );
 136           if( nread == -1 )
 137             {
 138               eofseen = 1;
 139               nread = 0;
 140             }
 141           n += nread;
 142           bzs->avail_in = n;
 143         }
 144       if (!eofseen)
 145         refill = 1;
 146
 147       if( DBG_FILTER )
 148         log_debug("enter bzDecompress: avail_in=%u, avail_out=%u\n",
 149                   (unsigned)bzs->avail_in, (unsigned)bzs->avail_out);
 150
 151       zrc=BZ2_bzDecompress(bzs);
 152       if( DBG_FILTER )
 153         log_debug("leave bzDecompress: avail_in=%u, avail_out=%u, zrc=%d\n",
 154                   (unsigned)bzs->avail_in, (unsigned)bzs->avail_out, zrc);
 155       if( zrc == BZ_STREAM_END )
 156         rc = -1; /* eof */
 157       else if( zrc != BZ_OK && zrc != BZ_PARAM_ERROR )
 158         log_fatal("bz2lib inflate problem: rc=%d\n", zrc );
 159       else if (zrc == BZ_OK && eofseen
 160                && !bzs->avail_in && bzs->avail_out > 0)
 161         {
 162           log_error ("unexpected EOF in bz2lib\n");
 163           rc = GPG_ERR_BAD_DATA;
 164           break;
 165         }
 166     }
 167   while( bzs->avail_out && zrc != BZ_STREAM_END && zrc != BZ_PARAM_ERROR );
 168
 169   /* I'm not completely happy with the two uses of BZ_PARAM_ERROR
 170      here.  The corresponding zlib function is Z_BUF_ERROR, which
 171      covers a narrower scope than BZ_PARAM_ERROR. -dshaw */
 172
 173   *ret_len = zfx->outbufsize - bzs->avail_out;
 174   if( DBG_FILTER )
 175     log_debug("do_uncompress: returning %u bytes\n", (unsigned)*ret_len );
 176   return rc;
 177 }
 178
 179 int
 180 compress_filter_bz2( void *opaque, int control,
 181                      IOBUF a, byte *buf, size_t *ret_len)
 182 {
 183   size_t size = *ret_len;
 184   compress_filter_context_t *zfx = opaque;
 185   bz_stream *bzs = zfx->opaque;
 186   int rc=0;
 187
 188   if( control == IOBUFCTRL_UNDERFLOW )
 189     {
 190       if( !zfx->status )
 191         {
 192           bzs = zfx->opaque = xmalloc_clear( sizeof *bzs );
 193           init_uncompress( zfx, bzs );
 194           zfx->status = 1;
 195         }
 196
 197       bzs->next_out = buf;
 198       bzs->avail_out = size;
 199       zfx->outbufsize = size; /* needed only for calculation */
 200       rc = do_uncompress( zfx, bzs, a, ret_len );
 201     }
 202   else if( control == IOBUFCTRL_FLUSH )
 203     {
 204       if( !zfx->status )
 205         {
 206           PACKET pkt;
 207           PKT_compressed cd;
 208
 209           if( zfx->algo != COMPRESS_ALGO_BZIP2 )
 210             BUG();
 211           memset( &cd, 0, sizeof cd );
 212           cd.len = 0;
 213           cd.algorithm = zfx->algo;
 214           init_packet( &pkt );
 215           pkt.pkttype = PKT_COMPRESSED;
 216           pkt.pkt.compressed = &cd;
 217           if( build_packet( a, &pkt ))
 218             log_bug("build_packet(PKT_COMPRESSED) failed\n");
 219           bzs = zfx->opaque = xmalloc_clear( sizeof *bzs );
 220           init_compress( zfx, bzs );
 221           zfx->status = 2;
 222         }
 223
 224       bzs->next_in = buf;
 225       bzs->avail_in = size;
 226       rc = do_compress( zfx, bzs, BZ_RUN, a );
 227     }
 228   else if( control == IOBUFCTRL_FREE )
 229     {
 230       if( zfx->status == 1 )
 231         {
 232           BZ2_bzDecompressEnd(bzs);
 233           xfree(bzs);
 234           zfx->opaque = NULL;
 235           xfree(zfx->outbuf); zfx->outbuf = NULL;
 236         }
 237       else if( zfx->status == 2 )
 238         {
 239           bzs->next_in = buf;
 240           bzs->avail_in = 0;
 241           do_compress( zfx, bzs, BZ_FINISH, a );
 242           BZ2_bzCompressEnd(bzs);
 243           xfree(bzs);
 244           zfx->opaque = NULL;
 245           xfree(zfx->outbuf); zfx->outbuf = NULL;
 246         }
 247       if (zfx->release)
 248         zfx->release (zfx);
 249     }
 250   else if( control == IOBUFCTRL_DESC )
 251     *(char**)buf = "compress_filter";
 252   return rc;
 253 }