onlineupdate/source/update/updater/bspatch.cxx

   1 /*-
   2  * Copyright 2003,2004 Colin Percival
   3  * All rights reserved
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted providing 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 ``AS IS'' AND ANY EXPRESS OR
  15  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  16  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
  18  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  22  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  23  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  24  * POSSIBILITY OF SUCH DAMAGE.
  25  *
  26  * Changelog:
  27  * 2005-04-26 - Define the header as a C structure, add a CRC32 checksum to
  28  *              the header, and make all the types 32-bit.
  29  *                --Benjamin Smedberg <benjamin@smedbergs.us>
  30  */
  31
  32 #include "bspatch.h"
  33 #include "errors.h"
  34
  35 #include <algorithm>
  36 #include <sys/stat.h>
  37 #include <stdlib.h>
  38 #include <stdio.h>
  39 #include <fcntl.h>
  40 #include <string.h>
  41 #include <limits.h>
  42
  43 #if defined(_WIN32)
  44 # include <io.h>
  45 #else
  46 # include <unistd.h>
  47 #endif
  48
  49 #ifdef _WIN32
  50 # include <winsock2.h>
  51 #else
  52 # include <arpa/inet.h>
  53 #endif
  54
  55 #ifndef SSIZE_MAX
  56 # define SSIZE_MAX LONG_MAX
  57 #endif
  58
  59 int
  60 MBS_ReadHeader(FILE* file, MBSPatchHeader *header)
  61 {
  62     size_t s = fread(header, 1, sizeof(MBSPatchHeader), file);
  63     if (s != sizeof(MBSPatchHeader))
  64         return READ_ERROR;
  65
  66     header->slen      = ntohl(header->slen);
  67     header->scrc32    = ntohl(header->scrc32);
  68     header->dlen      = ntohl(header->dlen);
  69     header->cblen     = ntohl(header->cblen);
  70     header->difflen   = ntohl(header->difflen);
  71     header->extralen  = ntohl(header->extralen);
  72
  73     struct stat hs;
  74     s = fstat(fileno(file), &hs);
  75     if (s)
  76         return READ_ERROR;
  77
  78     if (memcmp(header->tag, "MBDIFF10", 8) != 0)
  79         return UNEXPECTED_BSPATCH_ERROR;
  80
  81     if (sizeof(MBSPatchHeader) +
  82             header->cblen +
  83             header->difflen +
  84             header->extralen != uint32_t(hs.st_size))
  85         return UNEXPECTED_BSPATCH_ERROR;
  86
  87     return OK;
  88 }
  89
  90 int
  91 MBS_ApplyPatch(const MBSPatchHeader *header, FILE* patchFile,
  92                unsigned char *fbuffer, FILE* file)
  93 {
  94     unsigned char *fbufend = fbuffer + header->slen;
  95
  96     unsigned char *buf = (unsigned char*) malloc(header->cblen +
  97                          header->difflen +
  98                          header->extralen);
  99     if (!buf)
 100         return BSPATCH_MEM_ERROR;
 101
 102     int rv = OK;
 103
 104     size_t r = header->cblen + header->difflen + header->extralen;
 105     unsigned char *wb = buf;
 106     while (r)
 107     {
 108         const size_t count = std::min(r, size_t(SSIZE_MAX));
 109         size_t c = fread(wb, 1, count, patchFile);
 110         if (c != count)
 111         {
 112             rv = READ_ERROR;
 113             goto end;
 114         }
 115
 116         r -= c;
 117         wb += c;
 118     }
 119
 120     {
 121         MBSPatchTriple *ctrlsrc = (MBSPatchTriple*) buf;
 122         unsigned char *diffsrc = buf + header->cblen;
 123         unsigned char *extrasrc = diffsrc + header->difflen;
 124
 125         MBSPatchTriple *ctrlend = (MBSPatchTriple*) diffsrc;
 126         unsigned char *diffend = extrasrc;
 127         unsigned char *extraend = extrasrc + header->extralen;
 128
 129         do
 130         {
 131             ctrlsrc->x = ntohl(ctrlsrc->x);
 132             ctrlsrc->y = ntohl(ctrlsrc->y);
 133             ctrlsrc->z = ntohl(ctrlsrc->z);
 134
 135 #ifdef DEBUG_bsmedberg
 136             printf("Applying block:\n"
 137                    " x: %u\n"
 138                    " y: %u\n"
 139                    " z: %i\n",
 140                    ctrlsrc->x,
 141                    ctrlsrc->y,
 142                    ctrlsrc->z);
 143 #endif
 144
 145             /* Add x bytes from oldfile to x bytes from the diff block */
 146
 147             if (fbuffer + ctrlsrc->x > fbufend ||
 148                     diffsrc + ctrlsrc->x > diffend)
 149             {
 150                 rv = UNEXPECTED_BSPATCH_ERROR;
 151                 goto end;
 152             }
 153             for (uint32_t i = 0; i < ctrlsrc->x; ++i)
 154             {
 155                 diffsrc[i] += fbuffer[i];
 156             }
 157             if ((uint32_t) fwrite(diffsrc, 1, ctrlsrc->x, file) != ctrlsrc->x)
 158             {
 159                 rv = WRITE_ERROR_PATCH_FILE;
 160                 goto end;
 161             }
 162             fbuffer += ctrlsrc->x;
 163             diffsrc += ctrlsrc->x;
 164
 165             /* Copy y bytes from the extra block */
 166
 167             if (extrasrc + ctrlsrc->y > extraend)
 168             {
 169                 rv = UNEXPECTED_BSPATCH_ERROR;
 170                 goto end;
 171             }
 172             if ((uint32_t) fwrite(extrasrc, 1, ctrlsrc->y, file) != ctrlsrc->y)
 173             {
 174                 rv = WRITE_ERROR_PATCH_FILE;
 175                 goto end;
 176             }
 177             extrasrc += ctrlsrc->y;
 178
 179             /* "seek" forwards in oldfile by z bytes */
 180
 181             if (fbuffer + ctrlsrc->z > fbufend)
 182             {
 183                 rv = UNEXPECTED_BSPATCH_ERROR;
 184                 goto end;
 185             }
 186             fbuffer += ctrlsrc->z;
 187
 188             /* and on to the next control block */
 189
 190             ++ctrlsrc;
 191         }
 192         while (ctrlsrc < ctrlend);
 193     }
 194
 195 end:
 196     free(buf);
 197     return rv;
 198 }