/* Copies the dump file inside the xemacs executable.
   Copyright (C) 2003-2004 Olivier Galibert.
   Copyright (C) 2003 Larry McVoy.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided 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 ``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 LARRY
MCVOY, THE XEMACS PROJECT OR CONTRIBUTORS 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.

The views and conclusions contained in the software and documentation are those
of the authors and should not be interpreted as representing official policies,
either expressed or implied, of the XEmacs Project.

The "key" array is the work of Larry McVoy.  See
http://lkml.org/lkml/2003/7/11/141 for more information. */ 

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

static const unsigned char key[] = {
  255,
  6,
  1,
  2,
  3,
  4,
  255,
  3,
  9,
  62,
  255,
  10,
  4,
  61,
  255
};

int main(int argc, char **argv)
{
  FILE *te, *xe, *dump;
  unsigned char *xed, *p;
  long size, size_dump, size1, i;
  long max_size, offset;

  char msg[65536];

  if(argc != 6 && (argc != 3 || strcmp(argv[1], "-s"))) {
    fprintf(stderr, "Usage:\n%s temacs xemacs.dmp xemacs size offset\n%s -s xemacs.dmp\n", argv[0], argv[0]);
    exit(1);
  }

  if(argc == 3) {
    sprintf(msg, "Opening %s failed", argv[2]);
    dump = fopen(argv[2], "rb+");
    if(!dump) {
      perror(msg);
      exit(1);
    }

    if(fseek(dump, 0, SEEK_END)) {
      perror("fseek end dump");
      exit(1);
    }

    size = ftell(dump);
    if(size == -1) {
      perror("ftell dump");
      exit(1);
    }

    printf("%ld\n", size);
    exit(0);
  }


  max_size = strtol(argv[4], 0, 10);
  offset   = strtol(argv[5], 0, 10);

  sprintf(msg, "Opening %s failed", argv[1]);
  te = fopen(argv[1], "rb");
  if(!te) {
    perror(msg);
    exit(1);
  }

  if(fseek(te, 0, SEEK_END)) {
    perror("fseek end");
    exit(1);
  }

  size = ftell(te);
  if(size == -1) {
    perror("ftell");
    exit(1);
  }

  if(fseek(te, 0, SEEK_SET)) {
    perror("fseek beginning");
    exit(1);
  }

  xed = malloc(size);
  if(!xed) {
    perror("malloc");
    exit(1);
  }

  size1 = fread(xed, 1, size, te);
  if(size1 != size) {
    if(ferror(te)) {
      perror("fread temacs");
      exit(1);
    }
    fprintf(stderr, "Fread returned %ld, expected %ld ?\n", size1, size);
    exit(1);
  }

  if(fclose(te)) {
    perror("fclose temacs");
    exit(1);
  }

  p = xed;
  for(i=0; i<size-(long)sizeof(key); i++) {
    if(!memcmp(p, key, sizeof(key)))
      goto found;
    p++;
  }

  fprintf(stderr, "dumped_data key not found in executable.\n");
  exit(1);

 found:
  fprintf(stderr, "dumped_data found at offset 0x%lx, patching.\n", i);

  sprintf(msg, "Opening %s failed", argv[2]);
  dump = fopen(argv[2], "rb");
  if(!dump) {
    perror(msg);
    exit(1);
  }

  if(fseek(dump, 0, SEEK_END)) {
    perror("fseek end dump");
    exit(1);
  }

  size_dump = ftell(dump);
  if(size_dump == -1) {
    perror("ftell dump");
    exit(1);
  }

  if(size_dump > max_size) {
    fprintf(stderr, "Dump file too big for available space (max=%ld, dump=%ld)\n", max_size, size_dump);
    exit(2);
  }

  if(fseek(dump, 0, SEEK_SET)) {
    perror("fseek beginning dump");
    exit(1);
  }

  size1 = fread(xed+i+offset, 1, size_dump, dump);
  if(size1 != size_dump) {
    if(ferror(dump)) {
      perror("fread dump");
      exit(1);
    }
    fprintf(stderr, "Fread dump returned %ld, expected %ld ?\n", size1, size_dump);
    exit(1);
  }

  if(fclose(dump)) {
    perror("fclose dump");
    exit(1);
  }

  memset(xed+i, 0, offset);

  xed[i  ] = size_dump;
  xed[i+1] = size_dump >> 8;
  xed[i+2] = size_dump >> 16;
  xed[i+3] = size_dump >> 24;

  fprintf(stderr, "dumped_data found at offset 0x%lx, patching.\n", i);

  sprintf(msg, "Opening %s failed", argv[3]);
  xe = fopen(argv[3], "wb");
  if(!xe) {
    perror(msg);
    exit(1);
  }

  size1 = fwrite(xed, 1, size, xe);
  if(size1 != size) {
    if(ferror(xe)) {
      perror("fwrite xemacs");
      exit(1);
    }
    fprintf(stderr, "Fwrite xemacs returned %ld, expected %ld ?\n", size1, size);
    exit(1);
  }

  if(fclose(xe)) {
    perror("fclose xemacs");
    exit(1);
  }

  exit(0);
}