compression.c

/*
   BAREOS® - Backup Archiving REcovery Open Sourced

   Copyright (C) 2011-2011 Free Software Foundation Europe e.V.
   Copyright (C) 2011-2012 Planets Communications B.V.
   Copyright (C) 2013-2013 Bareos GmbH & Co. KG

   This program is Free Software; you can redistribute it and/or
   modify it under the terms of version three of the GNU Affero General Public
   License as published by the Free Software Foundation and included
   in the file LICENSE.

   This program is distributed in the hope that it will be useful, but
   WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
   Affero General Public License for more details.

   You should have received a copy of the GNU Affero General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
   02110-1301, USA.
*/
/**
 * Functions to handle compression/decompression of data.
 *
 * Extracted from other source files by Marco van Wieringen, June 2011
 */

#include "bareos.h"
#include "filed.h"

#if defined(HAVE_LZO) || defined(HAVE_LIBZ)

#ifdef HAVE_LZO
#include <lzo/lzoconf.h>
#include <lzo/lzo1x.h>
#endif

#ifdef HAVE_LIBZ
/*
 * Convert ZLIB error code into an ASCII message
 */
static const char *zlib_strerror(int stat)
{
   if (stat >= 0) {
      return _("None");
   }
   switch (stat) {
   case Z_ERRNO:
      return _("Zlib errno");
   case Z_STREAM_ERROR:
      return _("Zlib stream error");
   case Z_DATA_ERROR:
      return _("Zlib data error");
   case Z_MEM_ERROR:
      return _("Zlib memory error");
   case Z_BUF_ERROR:
      return _("Zlib buffer error");
   case Z_VERSION_ERROR:
      return _("Zlib version error");
   default:
      return _("*none*");
   }
}
#endif

void adjust_compression_buffers(JCR *jcr)
{
   /**
    * Adjust for compression so that output buffer is
    *  12 bytes + 0.1% larger than input buffer plus 18 bytes.
    *  This gives a bit extra plus room for the sparse addr if any.
    *  Note, we adjust the read size to be smaller so that the
    *  same output buffer can be used without growing it.
    *
    *  For LZO1X compression the recommended value is :
    *                  output_block_size = input_block_size + (input_block_size / 16) + 64 + 3 + sizeof(comp_stream_header)
    *
    * The zlib compression workset is initialized here to minimize
    *  the "per file" load. The jcr member is only set, if the init
    *  was successful.
    *
    *  For the same reason, lzo compression is initialized here.
    */
#ifdef HAVE_LZO
   jcr->compress_buf_size = MAX(jcr->buf_size + (jcr->buf_size / 16) + 67 + (int)sizeof(comp_stream_header),
                                jcr->buf_size + ((jcr->buf_size + 999) / 1000) + 30);
   jcr->compress_buf = get_memory(jcr->compress_buf_size);
#else
   jcr->compress_buf_size = jcr->buf_size + ((jcr->buf_size + 999) / 1000) + 30;
   jcr->compress_buf = get_memory(jcr->compress_buf_size);
#endif

#ifdef HAVE_LIBZ
   z_stream *pZlibStream = (z_stream*)malloc(sizeof(z_stream));
   if (pZlibStream) {
      pZlibStream->zalloc = Z_NULL;
      pZlibStream->zfree = Z_NULL;
      pZlibStream->opaque = Z_NULL;
      pZlibStream->state = Z_NULL;

      if (deflateInit(pZlibStream, Z_DEFAULT_COMPRESSION) == Z_OK) {
         jcr->pZLIB_compress_workset = pZlibStream;
      } else {
         free(pZlibStream);
      }
   }
#endif

#ifdef HAVE_LZO
   lzo_voidp pLzoMem = (lzo_voidp) malloc(LZO1X_1_MEM_COMPRESS);
   if (pLzoMem) {
      if (lzo_init() == LZO_E_OK) {
         jcr->LZO_compress_workset = pLzoMem;
      } else {
         free(pLzoMem);
      }
   }
#endif
}

bool adjust_decompression_buffers(JCR *jcr)
{
   uint32_t compress_buf_size;

   /*
    * Use the same buffer size to decompress both gzip and lzo
    */
   compress_buf_size = jcr->buf_size + 12 + ((jcr->buf_size + 999) / 1000) + 100;
   jcr->compress_buf = get_memory(compress_buf_size);
   jcr->compress_buf_size = compress_buf_size;

#ifdef HAVE_LZO
   if (lzo_init() != LZO_E_OK) {
      Jmsg(jcr, M_FATAL, 0, _("LZO init failed\n"));
      return false;
   }
#endif

   return true;
}

bool setup_compression_context(b_ctx &bctx)
{
   bool retval = false;

#ifdef HAVE_LIBZ
   int zstat;

   if ((bctx.ff_pkt->flags & FO_COMPRESS) &&
        bctx.ff_pkt->Compress_algo == COMPRESS_GZIP) {
      if ((bctx.ff_pkt->flags & FO_SPARSE) ||
          (bctx.ff_pkt->flags & FO_OFFSETS)) {
         bctx.cbuf = (Bytef *)bctx.jcr->compress_buf + OFFSET_FADDR_SIZE;
         bctx.max_compress_len = bctx.jcr->compress_buf_size - OFFSET_FADDR_SIZE;
      } else {
         bctx.cbuf = (Bytef *)bctx.jcr->compress_buf;
         bctx.max_compress_len = bctx.jcr->compress_buf_size; /* set max length */
      }
      bctx.wbuf = bctx.jcr->compress_buf; /* compressed output here */
      bctx.cipher_input = (uint8_t *)bctx.jcr->compress_buf; /* encrypt compressed data */

      /**
       * Only change zlib parameters if there is no pending operation.
       * This should never happen as deflatereset is called after each
       * deflate.
       */
      if (((z_stream*)bctx.jcr->pZLIB_compress_workset)->total_in == 0) {
         /** set gzip compression level - must be done per file */
         if ((zstat = deflateParams((z_stream*)bctx.jcr->pZLIB_compress_workset,
              bctx.ff_pkt->Compress_level, Z_DEFAULT_STRATEGY)) != Z_OK) {
            Jmsg(bctx.jcr, M_FATAL, 0, _("Compression deflateParams error: %d\n"), zstat);
            bctx.jcr->setJobStatus(JS_ErrorTerminated);
            goto bail_out;
         }
      }
   }
#endif
#ifdef HAVE_LZO
   memset(&bctx.ch, 0, sizeof(comp_stream_header));
   bctx.cbuf2 = NULL;

   if ((bctx.ff_pkt->flags & FO_COMPRESS) &&
        bctx.ff_pkt->Compress_algo == COMPRESS_LZO1X) {
      if ((bctx.ff_pkt->flags & FO_SPARSE) ||
          (bctx.ff_pkt->flags & FO_OFFSETS)) {
         bctx.cbuf = (Bytef *)bctx.jcr->compress_buf + OFFSET_FADDR_SIZE;
         bctx.cbuf2 = (Bytef *)bctx.jcr->compress_buf + OFFSET_FADDR_SIZE + sizeof(comp_stream_header);
         bctx.max_compress_len = bctx.jcr->compress_buf_size - OFFSET_FADDR_SIZE;
      } else {
         bctx.cbuf = (Bytef *)bctx.jcr->compress_buf;
         bctx.cbuf2 = (Bytef *)bctx.jcr->compress_buf + sizeof(comp_stream_header);
         bctx.max_compress_len = bctx.jcr->compress_buf_size; /* set max length */
      }
      bctx.ch.magic = COMPRESS_LZO1X;
      bctx.ch.version = COMP_HEAD_VERSION;
      bctx.wbuf = bctx.jcr->compress_buf; /* compressed output here */
      bctx.cipher_input = (uint8_t *)bctx.jcr->compress_buf; /* encrypt compressed data */
   }
#endif

   retval = true;

bail_out:
   return retval;
}

bool compress_data(b_ctx &bctx)
{
   bool retval = false;
   uint32_t input_len = bctx.jcr->store_bsock->msglen;

   bctx.compress_len = 0;
#ifdef HAVE_LIBZ
   if (bctx.ff_pkt->Compress_algo == COMPRESS_GZIP &&
       bctx.jcr->pZLIB_compress_workset) {
      int zstat;

      Dmsg3(400, "cbuf=0x%x rbuf=0x%x len=%u\n", bctx.cbuf, bctx.rbuf, input_len);

      ((z_stream*)bctx.jcr->pZLIB_compress_workset)->next_in = (Bytef *)bctx.rbuf;
      ((z_stream*)bctx.jcr->pZLIB_compress_workset)->avail_in = input_len;
      ((z_stream*)bctx.jcr->pZLIB_compress_workset)->next_out = (Bytef *)bctx.cbuf;
      ((z_stream*)bctx.jcr->pZLIB_compress_workset)->avail_out = bctx.max_compress_len;

      if ((zstat = deflate((z_stream*)bctx.jcr->pZLIB_compress_workset, Z_FINISH)) != Z_STREAM_END) {
         Jmsg(bctx.jcr, M_FATAL, 0, _("Compression deflate error: %d\n"), zstat);
         bctx.jcr->setJobStatus(JS_ErrorTerminated);
         goto bail_out;
      }

      bctx.compress_len = ((z_stream*)bctx.jcr->pZLIB_compress_workset)->total_out;

      /*
       * Reset zlib stream to be able to begin from scratch again
       */
      if ((zstat = deflateReset((z_stream*)bctx.jcr->pZLIB_compress_workset)) != Z_OK) {
         Jmsg(bctx.jcr, M_FATAL, 0, _("Compression deflateReset error: %d\n"), zstat);
         bctx.jcr->setJobStatus(JS_ErrorTerminated);
         goto bail_out;
      }

      Dmsg2(400, "GZIP compressed len=%d uncompressed len=%d\n", bctx.compress_len, input_len);

      bctx.jcr->store_bsock->msglen = bctx.compress_len; /* set compressed length */
      bctx.cipher_input_len = bctx.compress_len;
   }
#endif

#ifdef HAVE_LZO
   if (bctx.ff_pkt->Compress_algo == COMPRESS_LZO1X &&
       bctx.jcr->LZO_compress_workset) {
      int lzores;
      lzo_uint len;          /* TODO: See with the latest patch how to handle lzo_uint with 64bit */

      ser_declare;
      ser_begin(bctx.cbuf, sizeof(comp_stream_header));

      Dmsg3(400, "cbuf=0x%x rbuf=0x%x len=%u\n", bctx.cbuf, bctx.rbuf, input_len);

      lzores = lzo1x_1_compress((const unsigned char *)bctx.rbuf, input_len,
                                 bctx.cbuf2, &len, bctx.jcr->LZO_compress_workset);
      bctx.compress_len = len;
      if (lzores == LZO_E_OK && bctx.compress_len <= bctx.max_compress_len) {
         /*
          * Complete header
          */
         ser_uint32(COMPRESS_LZO1X);
         ser_uint32(bctx.compress_len);
         ser_uint16(bctx.ch.level);
         ser_uint16(bctx.ch.version);
      } else {
         /*
          * This should NEVER happen
          * */
         Jmsg(bctx.jcr, M_FATAL, 0, _("Compression LZO error: %d\n"), lzores);
         bctx.jcr->setJobStatus(JS_ErrorTerminated);
         goto bail_out;
      }

      Dmsg2(400, "LZO compressed len=%d uncompressed len=%d\n", bctx.compress_len, input_len);

      bctx.compress_len += sizeof(comp_stream_header); /* add size of header */
      bctx.jcr->store_bsock->msglen = bctx.compress_len; /* set compressed length */
      bctx.cipher_input_len = bctx.compress_len;
   }
#endif

   retval = true;

bail_out:
   return retval;
}

bool decompress_data(JCR *jcr, int32_t stream, char **data, uint32_t *length)
{
   char ec1[50]; /* Buffer printing huge values */

   Dmsg1(200, "Stream found in decompress_data(): %d\n", stream);
   switch (stream) {
   case STREAM_COMPRESSED_DATA:
   case STREAM_SPARSE_COMPRESSED_DATA:
   case STREAM_WIN32_COMPRESSED_DATA:
   case STREAM_ENCRYPTED_FILE_COMPRESSED_DATA:
   case STREAM_ENCRYPTED_WIN32_COMPRESSED_DATA: {
      uint32_t comp_magic, comp_len;
      uint16_t comp_level, comp_version;
#ifdef HAVE_LZO
      lzo_uint compress_len;
      const unsigned char *cbuf;
      int r, real_compress_len;
#endif

      /*
       * Read compress header
       */
      unser_declare;
      unser_begin(*data, sizeof(comp_stream_header));
      unser_uint32(comp_magic);
      unser_uint32(comp_len);
      unser_uint16(comp_level);
      unser_uint16(comp_version);
      Dmsg4(200, "Compressed data stream found: magic=0x%x, len=%d, level=%d, ver=0x%x\n",
            comp_magic, comp_len, comp_level, comp_version);

      /*
       * Version check
       */
      if (comp_version != COMP_HEAD_VERSION) {
         Qmsg(jcr, M_ERROR, 0, _("Compressed header version error. version=0x%x\n"), comp_version);
         return false;
      }

      /*
       * Size check
       */
      if (comp_len + sizeof(comp_stream_header) != *length) {
         Qmsg(jcr, M_ERROR, 0, _("Compressed header size error. comp_len=%d, msglen=%d\n"),
              comp_len, *length);
         return false;
      }

      /*
       * Based on the compression used perform the actual decompression of the data.
       */
      switch (comp_magic) {
#ifdef HAVE_LZO
         case COMPRESS_LZO1X:
            compress_len = jcr->compress_buf_size;
            cbuf = (const unsigned char*)*data + sizeof(comp_stream_header);
            real_compress_len = *length - sizeof(comp_stream_header);
            Dmsg2(200, "Comp_len=%d msglen=%d\n", compress_len, *length);
            while ((r=lzo1x_decompress_safe(cbuf, real_compress_len,
                                            (unsigned char *)jcr->compress_buf, &compress_len, NULL)) == LZO_E_OUTPUT_OVERRUN) {
               /*
                * The buffer size is too small, try with a bigger one
                */
               compress_len = jcr->compress_buf_size = jcr->compress_buf_size + (jcr->compress_buf_size >> 1);
               Dmsg2(200, "Comp_len=%d msglen=%d\n", compress_len, *length);
               jcr->compress_buf = check_pool_memory_size(jcr->compress_buf,
                                                    compress_len);
            }
            if (r != LZO_E_OK) {
               Qmsg(jcr, M_ERROR, 0, _("LZO uncompression error on file %s. ERR=%d\n"),
                    jcr->last_fname, r);
               return false;
            }
            *data = jcr->compress_buf;
            *length = compress_len;
            Dmsg2(200, "Write uncompressed %d bytes, total before write=%s\n", compress_len, edit_uint64(jcr->JobBytes, ec1));
            return true;
#endif
         default:
            Qmsg(jcr, M_ERROR, 0, _("Compression algorithm 0x%x found, but not supported!\n"), comp_magic);
            return false;
      }
      break;
   }
   default: {
#ifdef HAVE_LIBZ
      uLong compress_len;
      int status;

      /*
       * NOTE! We only use uLong and Byte because they are
       * needed by the zlib routines, they should not otherwise
       * be used in Bareos.
       */
      compress_len = jcr->compress_buf_size;
      Dmsg2(200, "Comp_len=%d msglen=%d\n", compress_len, *length);
      while ((status = uncompress((Byte *)jcr->compress_buf, &compress_len,
                              (const Byte *)*data, (uLong)*length)) == Z_BUF_ERROR) {
         /*
          * The buffer size is too small, try with a bigger one
          */
         compress_len = jcr->compress_buf_size = jcr->compress_buf_size + (jcr->compress_buf_size >> 1);
         Dmsg2(200, "Comp_len=%d msglen=%d\n", compress_len, *length);
         jcr->compress_buf = check_pool_memory_size(jcr->compress_buf,
                                                    compress_len);
      }
      if (status != Z_OK) {
         Qmsg(jcr, M_ERROR, 0, _("Uncompression error on file %s. ERR=%s\n"),
              jcr->last_fname, zlib_strerror(status));
         return false;
      }
      *data = jcr->compress_buf;
      *length = compress_len;
      Dmsg2(200, "Write uncompressed %d bytes, total before write=%s\n", compress_len, edit_uint64(jcr->JobBytes, ec1));
      return true;
   }
#endif
   }
}
#else
void adjust_compression_buffers(JCR *jcr)
{
}

bool setup_compression_context(b_ctx &bctx)
{
   return true;
}

bool compress_data(b_ctx &bctx)
{
   return true;
}

bool decompress_data(JCR *jcr, int32_t stream, char **data, uint32_t *length)
{
   Qmsg(jcr, M_ERROR, 0, _("Compressed data stream found, but compression not configured!\n"));
   return false;
}
#endif /* defined(HAVE_LZO) || defined(HAVE_LIBZ) */