summaryrefslogtreecommitdiff
path: root/onlineupdate/source/update/updater/bspatch.cxx
blob: 09a3c4354fcb04c408d5f11ef9f63b19344d922f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
/*-
 * Copyright 2003,2004 Colin Percival
 * All rights reserved
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted providing that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 * Changelog:
 * 2005-04-26 - Define the header as a C structure, add a CRC32 checksum to
 *              the header, and make all the types 32-bit.
 *                --Benjamin Smedberg <benjamin@smedbergs.us>
 */

#include "bspatch.h"
#include "errors.h"

#include <sys/stat.h>
#include <stdlib.h>
#include <stdio.h>
#include <fcntl.h>
#include <string.h>
#include <limits.h>

#if defined(_WIN32)
# include <io.h>
#else
# include <unistd.h>
#endif

#ifdef _WIN32
# include <winsock2.h>
#else
# include <arpa/inet.h>
#endif

#ifndef SSIZE_MAX
# define SSIZE_MAX LONG_MAX
#endif

int
MBS_ReadHeader(FILE* file, MBSPatchHeader *header)
{
  size_t s = fread(header, 1, sizeof(MBSPatchHeader), file);
  if (s != sizeof(MBSPatchHeader))
    return READ_ERROR;

  header->slen      = ntohl(header->slen);
  header->scrc32    = ntohl(header->scrc32);
  header->dlen      = ntohl(header->dlen);
  header->cblen     = ntohl(header->cblen);
  header->difflen   = ntohl(header->difflen);
  header->extralen  = ntohl(header->extralen);

  struct stat hs;
  s = fstat(fileno(file), &hs);
  if (s)
    return READ_ERROR;

  if (memcmp(header->tag, "MBDIFF10", 8) != 0)
    return UNEXPECTED_BSPATCH_ERROR;

  if (sizeof(MBSPatchHeader) +
      header->cblen +
      header->difflen +
      header->extralen != uint32_t(hs.st_size))
    return UNEXPECTED_BSPATCH_ERROR;

  return OK;
}

int
MBS_ApplyPatch(const MBSPatchHeader *header, FILE* patchFile,
               unsigned char *fbuffer, FILE* file)
{
  unsigned char *fbufend = fbuffer + header->slen;

  unsigned char *buf = (unsigned char*) malloc(header->cblen +
                                               header->difflen +
                                               header->extralen);
  if (!buf)
    return BSPATCH_MEM_ERROR;

  int rv = OK;

  size_t r = header->cblen + header->difflen + header->extralen;
  unsigned char *wb = buf;
  while (r) {
    const size_t count = (r > SSIZE_MAX) ? SSIZE_MAX : r;
    size_t c = fread(wb, 1, count, patchFile);
    if (c != count) {
      rv = READ_ERROR;
      goto end;
    }

    r -= c;
    wb += c;
  }

  {
    MBSPatchTriple *ctrlsrc = (MBSPatchTriple*) buf;
    unsigned char *diffsrc = buf + header->cblen;
    unsigned char *extrasrc = diffsrc + header->difflen;

    MBSPatchTriple *ctrlend = (MBSPatchTriple*) diffsrc;
    unsigned char *diffend = extrasrc;
    unsigned char *extraend = extrasrc + header->extralen;

    do {
      ctrlsrc->x = ntohl(ctrlsrc->x);
      ctrlsrc->y = ntohl(ctrlsrc->y);
      ctrlsrc->z = ntohl(ctrlsrc->z);

#ifdef DEBUG_bsmedberg
      printf("Applying block:\n"
             " x: %u\n"
             " y: %u\n"
             " z: %i\n",
             ctrlsrc->x,
             ctrlsrc->y,
             ctrlsrc->z);
#endif

      /* Add x bytes from oldfile to x bytes from the diff block */

      if (fbuffer + ctrlsrc->x > fbufend ||
          diffsrc + ctrlsrc->x > diffend) {
        rv = UNEXPECTED_BSPATCH_ERROR;
        goto end;
      }
      for (uint32_t i = 0; i < ctrlsrc->x; ++i) {
        diffsrc[i] += fbuffer[i];
      }
      if ((uint32_t) fwrite(diffsrc, 1, ctrlsrc->x, file) != ctrlsrc->x) {
        rv = WRITE_ERROR_PATCH_FILE;
        goto end;
      }
      fbuffer += ctrlsrc->x;
      diffsrc += ctrlsrc->x;

      /* Copy y bytes from the extra block */

      if (extrasrc + ctrlsrc->y > extraend) {
        rv = UNEXPECTED_BSPATCH_ERROR;
        goto end;
      }
      if ((uint32_t) fwrite(extrasrc, 1, ctrlsrc->y, file) != ctrlsrc->y) {
        rv = WRITE_ERROR_PATCH_FILE;
        goto end;
      }
      extrasrc += ctrlsrc->y;

      /* "seek" forwards in oldfile by z bytes */

      if (fbuffer + ctrlsrc->z > fbufend) {
        rv = UNEXPECTED_BSPATCH_ERROR;
        goto end;
      }
      fbuffer += ctrlsrc->z;

      /* and on to the next control block */

      ++ctrlsrc;
    } while (ctrlsrc < ctrlend);
  }

end:
  free(buf);
  return rv;
}