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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.
*/
#if 0
__FBSDID("$FreeBSD: src/usr.bin/bsdiff/bspatch/bspatch.c,v 1.1 2005/08/06 01:59:06 cperciva Exp $");
#endif
#include <bspatch.h>
#include <bzlib.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <err.h>
#include <unistd.h>
#include <fcntl.h>
#ifndef u_char
typedef unsigned char u_char;
#endif
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(int argc,char * argv[])
{
FILE * f, * cpf, * dpf, * epf;
BZFILE * cpfbz2, * dpfbz2, * epfbz2;
int cbz2err, dbz2err, ebz2err;
int fd;
ssize_t oldsize,newsize;
ssize_t bzctrllen,bzdatalen;
u_char header[32],buf[8];
u_char *old, *new;
off_t oldpos,newpos;
off_t ctrl[3];
off_t lenread;
off_t i;
if(argc!=4) errx(1,"usage: %s oldfile newfile patchfile\n",argv[0]);
/* Open patch file */
if ((f = fopen(argv[3], "r")) == NULL)
err(1, "fopen(%s)", argv[3]);
/*
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");
err(1, "fread(%s)", argv[3]);
}
/* Check for appropriate magic */
if (memcmp(header, "BSDIFF40", 8) != 0)
errx(1, "Corrupt patch\n");
/* 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");
/* Close patch file and re-open it via libbzip2 at the right places */
if (fclose(f))
err(1, "fclose(%s)", argv[3]);
if ((cpf = fopen(argv[3], "r")) == NULL)
err(1, "fopen(%s)", argv[3]);
if (fseeko(cpf, 32, SEEK_SET))
err(1, "fseeko(%s, %lld)", argv[3],
(long long)32);
if ((cpfbz2 = BZ2_bzReadOpen(&cbz2err, cpf, 0, 0, NULL, 0)) == NULL)
errx(1, "BZ2_bzReadOpen, bz2err = %d", cbz2err);
if ((dpf = fopen(argv[3], "r")) == NULL)
err(1, "fopen(%s)", argv[3]);
if (fseeko(dpf, 32 + bzctrllen, SEEK_SET))
err(1, "fseeko(%s, %lld)", argv[3],
(long long)(32 + bzctrllen));
if ((dpfbz2 = BZ2_bzReadOpen(&dbz2err, dpf, 0, 0, NULL, 0)) == NULL)
errx(1, "BZ2_bzReadOpen, bz2err = %d", dbz2err);
if ((epf = fopen(argv[3], "r")) == NULL)
err(1, "fopen(%s)", argv[3]);
if (fseeko(epf, 32 + bzctrllen + bzdatalen, SEEK_SET))
err(1, "fseeko(%s, %lld)", argv[3],
(long long)(32 + bzctrllen + bzdatalen));
if ((epfbz2 = BZ2_bzReadOpen(&ebz2err, epf, 0, 0, NULL, 0)) == NULL)
errx(1, "BZ2_bzReadOpen, bz2err = %d", ebz2err);
if(((fd=open(argv[1],O_RDONLY,0))<0) ||
((oldsize=lseek(fd,0,SEEK_END))==-1) ||
((old=malloc(oldsize+1))==NULL) ||
(lseek(fd,0,SEEK_SET)!=0) ||
(read(fd,old,oldsize)!=oldsize) ||
(close(fd)==-1)) err(1,"%s",argv[1]);
if((new=malloc(newsize+1))==NULL) err(1,NULL);
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");
ctrl[i]=offtin(buf);
};
/* Sanity-check */
if(newpos+ctrl[0]>newsize)
errx(1,"Corrupt patch\n");
/* Read diff string */
lenread = BZ2_bzRead(&dbz2err, dpfbz2, new + newpos, ctrl[0]);
if ((lenread < ctrl[0]) ||
((dbz2err != BZ_OK) && (dbz2err != BZ_STREAM_END)))
errx(1, "Corrupt patch\n");
/* Add old data to diff string */
for(i=0;i<ctrl[0];i++)
if((oldpos+i>=0) && (oldpos+i<oldsize))
new[newpos+i]+=old[oldpos+i];
/* Adjust pointers */
newpos+=ctrl[0];
oldpos+=ctrl[0];
/* Sanity-check */
if(newpos+ctrl[1]>newsize)
errx(1,"Corrupt patch\n");
/* Read extra string */
lenread = BZ2_bzRead(&ebz2err, epfbz2, new + newpos, ctrl[1]);
if ((lenread < ctrl[1]) ||
((ebz2err != BZ_OK) && (ebz2err != BZ_STREAM_END)))
errx(1, "Corrupt patch\n");
/* 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]);
/* Write the new file */
if(((fd=open(argv[2],O_CREAT|O_TRUNC|O_WRONLY,0666))<0) ||
(write(fd,new,newsize)!=newsize) || (close(fd)==-1))
err(1,"%s",argv[2]);
free(new);
free(old);
return 0;
}
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