pollymc/patchlib/bspatch.c

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/*-
* Copyright 2003-2005 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.
*/
#ifdef _MSC_VER
// bogus 'secure' nonsense
#define _CRT_SECURE_NO_WARNINGS
// bogus signed/unsigned mismatch
#pragma warning( disable: 4018)
#endif
#ifdef _WIN32
#include <sys/types.h>
#define ssize_t size_t
#else
#include <unistd.h>
#endif
#if defined __APPLE__ && defined __MACH__
typedef unsigned char u_char;
#endif
#include "bzlib.h"
#include "bspatch.h"
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <fcntl.h>
static off_t offtin(u_char *buf)
{
off_t y;
y=buf[7]&0x7F;
y=y*256;y+=buf[6];
y=y*256;y+=buf[5];
y=y*256;y+=buf[4];
y=y*256;y+=buf[3];
y=y*256;y+=buf[2];
y=y*256;y+=buf[1];
y=y*256;y+=buf[0];
if(buf[7]&0x80) y=-y;
return y;
}
int bspatch(const char * oldfile, const char * newfile, const char * patchfile)
{
FILE * f, * cpf, * dpf, * epf;
BZFILE * cpfbz2, * dpfbz2, * epfbz2;
int cbz2err, dbz2err, ebz2err;
FILE * temp;
ssize_t oldsize,newsize;
ssize_t bzctrllen,bzdatalen;
unsigned char header[32],buf[8];
unsigned char *old_contents;
unsigned char *new_contents;
off_t oldpos,newpos;
off_t ctrl[3];
off_t lenread;
off_t i;
/* Open patch file */
if ((f = fopen(patchfile, "rb")) == NULL)
{
//err(1, "fopen(%s)", argv[3]);
return ERR_OTHER;
}
/*
File format:
0 8 "BSDIFF40"
8 8 X
16 8 Y
24 8 sizeof(newfile)
32 X bzip2(control block)
32+X Y bzip2(diff block)
32+X+Y ??? bzip2(extra block)
with control block a set of triples (x,y,z) meaning "add x bytes
from oldfile to x bytes from the diff block; copy y bytes from the
extra block; seek forwards in oldfile by z bytes".
*/
/* Read header */
if (fread(header, 1, 32, f) < 32)
{
if (feof(f))
{
//errx(1, "Corrupt patch\n");
return ERR_CORRUPT_PATCH;
}
//err(1, "fread(%s)", argv[3]);
return ERR_OTHER;
}
/* Check for appropriate magic */
if (memcmp(header, "BSDIFF40", 8) != 0)
{
//errx(1, "Corrupt patch\n");
return ERR_CORRUPT_PATCH;
}
/* Read lengths from header */
bzctrllen=offtin(header+8);
bzdatalen=offtin(header+16);
newsize=offtin(header+24);
if((bzctrllen<0) || (bzdatalen<0) || (newsize<0))
{
//errx(1,"Corrupt patch\n");
return ERR_CORRUPT_PATCH;
}
/* Close patch file and re-open it via libbzip2 at the right places */
if (fclose(f))
{
//err(1, "fclose(%s)", argv[3]);
return ERR_OTHER;
}
if ((cpf = fopen(patchfile, "rb")) == NULL)
{
//err(1, "fopen(%s)", argv[3]);
return ERR_OTHER;
}
if (fseek(cpf, 32, SEEK_SET))
{
// err(1, "fseeko(%s, %lld)", argv[3], (long long)32);
return ERR_OTHER;
}
if ((cpfbz2 = BZ2_bzReadOpen(&cbz2err, cpf, 0, 0, NULL, 0)) == NULL)
{
//errx(1, "BZ2_bzReadOpen, bz2err = %d", cbz2err);
return ERR_OTHER;
}
if ((dpf = fopen(patchfile, "rb")) == NULL)
{
//err(1, "fopen(%s)", argv[3]);
return ERR_OTHER;
}
if (fseek(dpf, 32 + bzctrllen, SEEK_SET))
{
//err(1, "fseeko(%s, %lld)", argv[3], (long long)(32 + bzctrllen));
return ERR_OTHER;
}
if ((dpfbz2 = BZ2_bzReadOpen(&dbz2err, dpf, 0, 0, NULL, 0)) == NULL)
{
//errx(1, "BZ2_bzReadOpen, bz2err = %d", dbz2err);
return ERR_OTHER;
}
if ((epf = fopen(patchfile, "rb")) == NULL)
{
//err(1, "fopen(%s)", argv[3]);
return ERR_OTHER;
}
if (fseek(epf, 32 + bzctrllen + bzdatalen, SEEK_SET))
{
//err(1, "fseeko(%s, %lld)", argv[3], (long long)(32 + bzctrllen + bzdatalen));
return ERR_OTHER;
}
if ((epfbz2 = BZ2_bzReadOpen(&ebz2err, epf, 0, 0, NULL, 0)) == NULL)
{
//errx(1, "BZ2_bzReadOpen, bz2err = %d", ebz2err);
return ERR_OTHER;
}
if((temp=fopen(oldfile,"rb")) == NULL)
{
return ERR_OTHER;
}
if((fseek(temp,0,SEEK_END))!=0)
{
return ERR_OTHER;
}
oldsize = ftell(temp);
if((old_contents=malloc(oldsize+1))==NULL)
{
return ERR_OTHER;
}
rewind(temp);
if(fread(old_contents,oldsize,1,temp)!=1)
{
return ERR_OTHER;
}
if(fclose(temp)==EOF)
{
return ERR_OTHER;
}
if((new_contents=malloc(newsize+1))==NULL)
{
//err(1,NULL);
return ERR_OTHER;
}
oldpos=0;newpos=0;
while(newpos<newsize)
{
/* Read control data */
for(i=0;i<=2;i++) {
lenread = BZ2_bzRead(&cbz2err, cpfbz2, buf, 8);
if ((lenread < 8) || ((cbz2err != BZ_OK) && (cbz2err != BZ_STREAM_END)))
{
//errx(1, "Corrupt patch\n");
return ERR_CORRUPT_PATCH;
}
ctrl[i]=offtin(buf);
};
/* Sanity-check */
if(newpos+ctrl[0]>newsize)
{
//errx(1,"Corrupt patch\n");
return ERR_CORRUPT_PATCH;
}
/* Read diff string */
lenread = BZ2_bzRead(&dbz2err, dpfbz2, new_contents + newpos, ctrl[0]);
if ((lenread < ctrl[0]) || ((dbz2err != BZ_OK) && (dbz2err != BZ_STREAM_END)))
{
//errx(1, "Corrupt patch\n");
return ERR_CORRUPT_PATCH;
}
/* Add old data to diff string */
for(i=0;i<ctrl[0];i++)
{
if((oldpos+i>=0) && (oldpos+i<oldsize))
{
new_contents[newpos+i]+=old_contents[oldpos+i];
}
}
/* Adjust pointers */
newpos+=ctrl[0];
oldpos+=ctrl[0];
/* Sanity-check */
if(newpos+ctrl[1]>newsize)
{
//errx(1,"Corrupt patch\n");
return ERR_CORRUPT_PATCH;
}
/* Read extra string */
lenread = BZ2_bzRead(&ebz2err, epfbz2, new_contents + newpos, ctrl[1]);
if ((lenread < ctrl[1]) || ((ebz2err != BZ_OK) && (ebz2err != BZ_STREAM_END)))
{
//errx(1, "Corrupt patch\n");
return ERR_CORRUPT_PATCH;
}
/* Adjust pointers */
newpos+=ctrl[1];
oldpos+=ctrl[2];
};
/* Clean up the bzip2 reads */
BZ2_bzReadClose(&cbz2err, cpfbz2);
BZ2_bzReadClose(&dbz2err, dpfbz2);
BZ2_bzReadClose(&ebz2err, epfbz2);
if (fclose(cpf) || fclose(dpf) || fclose(epf))
{
//err(1, "fclose(%s)", argv[3]);
return ERR_OTHER;
}
/* Write the new file */
if(
((temp=fopen(newfile,"wb"))==NULL) ||
(fwrite(new_contents,newsize,1,temp)==0) ||
(fclose(temp)==EOF)
)
{
//err(1,"%s",argv[2]);
return ERR_OTHER;
}
free(new_contents);
free(old_contents);
return ERR_NONE;
}