Subversion Repositories vaca_plus

/*-

 * 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 <bzlib.h>

#include <stdlib.h>

#include <stdio.h>

#include <string.h>

#include <err.h>

#include <unistd.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 main(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:

                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;

}