third_party/bspatch/mbspatch.cc

   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  * 2007-11-14 - Added CalculateCrc() and ApplyBinaryPatch() methods.
  31  *                --Rahul Kuchhal
  32  */
  33
  34 #include "mbspatch.h"
  35
  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 #ifdef _WIN32
  44 # include <io.h>
  45 # include <winsock2.h>
  46 #else
  47 # include <unistd.h>
  48 # include <arpa/inet.h>
  49 #endif
  50
  51 extern "C" {
  52 #include <7zCrc.h>
  53 }
  54
  55 #ifndef SSIZE_MAX
  56 # define SSIZE_MAX LONG_MAX
  57 #endif
  58
  59 int
  60 MBS_ReadHeader(int fd, MBSPatchHeader *header)
  61 {
  62   int s = read(fd, header, sizeof(MBSPatchHeader));
  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(fd, &hs);
  75   if (s)
  76     return READ_ERROR;
  77
  78   if (memcmp(header->tag, "MBDIFF10", 8) != 0)
  79     return UNEXPECTED_ERROR;
  80
  81   if (sizeof(MBSPatchHeader) +
  82       header->cblen +
  83       header->difflen +
  84       header->extralen != int(hs.st_size))
  85     return UNEXPECTED_ERROR;
  86
  87   return OK;
  88 }
  89
  90 int
  91 MBS_ApplyPatch(const MBSPatchHeader *header, int patchfd,
  92                unsigned char *fbuffer, int filefd)
  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 MEM_ERROR;
 101
 102   int rv = OK;
 103
 104   int r = header->cblen + header->difflen + header->extralen;
 105   unsigned char *wb = buf;
 106   while (r) {
 107     int c = read(patchfd, wb, (r > SSIZE_MAX) ? SSIZE_MAX : r);
 108     if (c < 0) {
 109       rv = READ_ERROR;
 110       goto end;
 111     }
 112
 113     r -= c;
 114
 115     if (c == 0 && r) {
 116       rv = UNEXPECTED_ERROR;
 117       goto end;
 118     }
 119   }
 120
 121   {
 122     MBSPatchTriple *ctrlsrc = (MBSPatchTriple*) buf;
 123     unsigned char *diffsrc = buf + header->cblen;
 124     unsigned char *extrasrc = diffsrc + header->difflen;
 125
 126     MBSPatchTriple *ctrlend = (MBSPatchTriple*) diffsrc;
 127     unsigned char *diffend = extrasrc;
 128     unsigned char *extraend = extrasrc + header->extralen;
 129
 130     do {
 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         rv = UNEXPECTED_ERROR;
 150         goto end;
 151       }
 152       for (unsigned int i = 0; i < ctrlsrc->x; ++i) {
 153         diffsrc[i] += fbuffer[i];
 154       }
 155       if ((int) write(filefd, diffsrc, ctrlsrc->x) != ctrlsrc->x) {
 156         rv = WRITE_ERROR;
 157         goto end;
 158       }
 159       fbuffer += ctrlsrc->x;
 160       diffsrc += ctrlsrc->x;
 161
 162       /* Copy y bytes from the extra block */
 163
 164       if (extrasrc + ctrlsrc->y > extraend) {
 165         rv = UNEXPECTED_ERROR;
 166         goto end;
 167       }
 168       if ((int) write(filefd, extrasrc, ctrlsrc->y) != ctrlsrc->y) {
 169         rv = WRITE_ERROR;
 170         goto end;
 171       }
 172       extrasrc += ctrlsrc->y;
 173
 174       /* "seek" forwards in oldfile by z bytes */
 175
 176       if (fbuffer + ctrlsrc->z > fbufend) {
 177         rv = UNEXPECTED_ERROR;
 178         goto end;
 179       }
 180       fbuffer += ctrlsrc->z;
 181
 182       /* and on to the next control block */
 183
 184       ++ctrlsrc;
 185     } while (ctrlsrc < ctrlend);
 186   }
 187
 188 end:
 189   free(buf);
 190   return rv;
 191 }
 192
 193 int CalculateCrc(const unsigned char *buf, int size) {
 194   CrcGenerateTable();
 195   unsigned int crc = 0xffffffffL;
 196   crc = ~CrcCalc(buf, size);
 197   return crc;
 198 }
 199
 200 /* _O_BINARY is a MSWindows open() mode flag.  When absent, MSWindows
 201  * open() translates CR+LF to LF; when present, it passes bytes
 202  * through faithfully.  Under *nix, we are always in binary mode, so
 203  * the following #define turns this flag into a no-op w.r.t.  bitwise
 204  * OR.  Note that this would be DANGEROUS AND UNSOUND if we used
 205  * _O_BINARY other than as a bitwise OR mask (e.g., as a bitwise AND
 206  * mask to check for binary mode), but it seems OK in the limited
 207  * context of the following small function. */
 208 #ifndef _O_BINARY
 209 # define _O_BINARY 0
 210 #endif
 211
 212 int ApplyBinaryPatch(const wchar_t *old_file, const wchar_t *patch_file,
 213                      const wchar_t *new_file) {
 214   int ret = OK;
 215   int ofd = -1;
 216   int nfd = -1;
 217   unsigned char *buf = NULL;
 218
 219   int pfd = _wopen(patch_file, O_RDONLY | _O_BINARY);
 220   if (pfd < 0) return READ_ERROR;
 221
 222   do {
 223     MBSPatchHeader header;
 224     if ((ret = MBS_ReadHeader(pfd, &header)))
 225       break;
 226
 227     ofd = _wopen(old_file, O_RDONLY | _O_BINARY);
 228     if (ofd < 0) {
 229       ret = READ_ERROR;
 230       break;
 231     }
 232
 233     struct stat os;
 234     if ((ret = fstat(ofd, &os))) {
 235       ret = READ_ERROR;
 236       break;
 237     }
 238
 239     if (os.st_size != header.slen) {
 240       ret = UNEXPECTED_ERROR;
 241       break;
 242     }
 243
 244     buf = (unsigned char*) malloc(header.slen);
 245     if (!buf) {
 246       ret = MEM_ERROR;
 247       break;
 248     }
 249
 250     if (read(ofd, buf, header.slen) != header.slen) {
 251       ret = READ_ERROR;
 252       break;
 253     }
 254
 255     if (CalculateCrc(buf, header.slen) != header.scrc32) {
 256       ret = CRC_ERROR;
 257       break;
 258     }
 259
 260     nfd = _wopen(new_file, O_WRONLY | O_TRUNC | O_CREAT | _O_BINARY);
 261     if (nfd < 0) {
 262       ret = READ_ERROR;
 263       break;
 264     }
 265
 266     MBS_ApplyPatch(&header, pfd, buf, nfd);
 267   } while (0);
 268
 269   free(buf);
 270   close(pfd);
 271   if (ofd >= 0) close(ofd);
 272   if (nfd >= 0) close(nfd);
 273   return ret;
 274 }