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      1 /*-
      2  * Copyright 2003-2005 Colin Percival
      3  * All rights reserved
      4  *
      5  * Redistribution and use in source and binary forms, with or without
      6  * modification, are permitted providing that the following conditions
      7  * are met:
      8  * 1. Redistributions of source code must retain the above copyright
      9  *    notice, this list of conditions and the following disclaimer.
     10  * 2. Redistributions in binary form must reproduce the above copyright
     11  *    notice, this list of conditions and the following disclaimer in the
     12  *    documentation and/or other materials provided with the distribution.
     13  *
     14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     15  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
     16  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
     18  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
     22  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
     23  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     24  * POSSIBILITY OF SUCH DAMAGE.
     25  */
     26 
     27 #if 0
     28 __FBSDID("$FreeBSD: src/usr.bin/bsdiff/bspatch/bspatch.c,v 1.1 2005/08/06 01:59:06 cperciva Exp $");
     29 #endif
     30 
     31 #include <bzlib.h>
     32 #include <stdlib.h>
     33 #include <stdio.h>
     34 #include <string.h>
     35 #include <err.h>
     36 #include <unistd.h>
     37 #include <fcntl.h>
     38 #include <sys/types.h>    // android
     39 
     40 static off_t offtin(u_char *buf)
     41 {
     42 	off_t y;
     43 
     44 	y=buf[7]&0x7F;
     45 	y=y*256;y+=buf[6];
     46 	y=y*256;y+=buf[5];
     47 	y=y*256;y+=buf[4];
     48 	y=y*256;y+=buf[3];
     49 	y=y*256;y+=buf[2];
     50 	y=y*256;y+=buf[1];
     51 	y=y*256;y+=buf[0];
     52 
     53 	if(buf[7]&0x80) y=-y;
     54 
     55 	return y;
     56 }
     57 
     58 int main(int argc,char * argv[])
     59 {
     60 	FILE * f, * cpf, * dpf, * epf;
     61 	BZFILE * cpfbz2, * dpfbz2, * epfbz2;
     62 	int cbz2err, dbz2err, ebz2err;
     63 	int fd;
     64 	ssize_t oldsize,newsize;
     65 	ssize_t bzctrllen,bzdatalen;
     66 	u_char header[32],buf[8];
     67 	u_char *old, *new;
     68 	off_t oldpos,newpos;
     69 	off_t ctrl[3];
     70 	off_t lenread;
     71 	off_t i;
     72 
     73 	if(argc!=4) errx(1,"usage: %s oldfile newfile patchfile\n",argv[0]);
     74 
     75 	/* Open patch file */
     76 	if ((f = fopen(argv[3], "r")) == NULL)
     77 		err(1, "fopen(%s)", argv[3]);
     78 
     79 	/*
     80 	File format:
     81 		0	8	"BSDIFF40"
     82 		8	8	X
     83 		16	8	Y
     84 		24	8	sizeof(newfile)
     85 		32	X	bzip2(control block)
     86 		32+X	Y	bzip2(diff block)
     87 		32+X+Y	???	bzip2(extra block)
     88 	with control block a set of triples (x,y,z) meaning "add x bytes
     89 	from oldfile to x bytes from the diff block; copy y bytes from the
     90 	extra block; seek forwards in oldfile by z bytes".
     91 	*/
     92 
     93 	/* Read header */
     94 	if (fread(header, 1, 32, f) < 32) {
     95 		if (feof(f))
     96 			errx(1, "Corrupt patch\n");
     97 		err(1, "fread(%s)", argv[3]);
     98 	}
     99 
    100 	/* Check for appropriate magic */
    101 	if (memcmp(header, "BSDIFF40", 8) != 0)
    102 		errx(1, "Corrupt patch\n");
    103 
    104 	/* Read lengths from header */
    105 	bzctrllen=offtin(header+8);
    106 	bzdatalen=offtin(header+16);
    107 	newsize=offtin(header+24);
    108 	if((bzctrllen<0) || (bzdatalen<0) || (newsize<0))
    109 		errx(1,"Corrupt patch\n");
    110 
    111 	/* Close patch file and re-open it via libbzip2 at the right places */
    112 	if (fclose(f))
    113 		err(1, "fclose(%s)", argv[3]);
    114 	if ((cpf = fopen(argv[3], "r")) == NULL)
    115 		err(1, "fopen(%s)", argv[3]);
    116 	if (fseeko(cpf, 32, SEEK_SET))
    117 		err(1, "fseeko(%s, %lld)", argv[3],
    118 		    (long long)32);
    119 	if ((cpfbz2 = BZ2_bzReadOpen(&cbz2err, cpf, 0, 0, NULL, 0)) == NULL)
    120 		errx(1, "BZ2_bzReadOpen, bz2err = %d", cbz2err);
    121 	if ((dpf = fopen(argv[3], "r")) == NULL)
    122 		err(1, "fopen(%s)", argv[3]);
    123 	if (fseeko(dpf, 32 + bzctrllen, SEEK_SET))
    124 		err(1, "fseeko(%s, %lld)", argv[3],
    125 		    (long long)(32 + bzctrllen));
    126 	if ((dpfbz2 = BZ2_bzReadOpen(&dbz2err, dpf, 0, 0, NULL, 0)) == NULL)
    127 		errx(1, "BZ2_bzReadOpen, bz2err = %d", dbz2err);
    128 	if ((epf = fopen(argv[3], "r")) == NULL)
    129 		err(1, "fopen(%s)", argv[3]);
    130 	if (fseeko(epf, 32 + bzctrllen + bzdatalen, SEEK_SET))
    131 		err(1, "fseeko(%s, %lld)", argv[3],
    132 		    (long long)(32 + bzctrllen + bzdatalen));
    133 	if ((epfbz2 = BZ2_bzReadOpen(&ebz2err, epf, 0, 0, NULL, 0)) == NULL)
    134 		errx(1, "BZ2_bzReadOpen, bz2err = %d", ebz2err);
    135 
    136 	if(((fd=open(argv[1],O_RDONLY,0))<0) ||
    137 		((oldsize=lseek(fd,0,SEEK_END))==-1) ||
    138 		((old=malloc(oldsize+1))==NULL) ||
    139 		(lseek(fd,0,SEEK_SET)!=0) ||
    140 		(read(fd,old,oldsize)!=oldsize) ||
    141 		(close(fd)==-1)) err(1,"%s",argv[1]);
    142 	if((new=malloc(newsize+1))==NULL) err(1,NULL);
    143 
    144 	oldpos=0;newpos=0;
    145 	while(newpos<newsize) {
    146 		/* Read control data */
    147 		for(i=0;i<=2;i++) {
    148 			lenread = BZ2_bzRead(&cbz2err, cpfbz2, buf, 8);
    149 			if ((lenread < 8) || ((cbz2err != BZ_OK) &&
    150 			    (cbz2err != BZ_STREAM_END)))
    151 				errx(1, "Corrupt patch\n");
    152 			ctrl[i]=offtin(buf);
    153 		};
    154 
    155 		// android local change (start)
    156 		if (ctrl[0]<0||ctrl[1]<0)
    157 			errx(1,"Corrupt patch\n");
    158 		// android local change (end)
    159 
    160 		/* Sanity-check */
    161 		if(newpos+ctrl[0]>newsize)
    162 			errx(1,"Corrupt patch\n");
    163 
    164 		/* Read diff string */
    165 		lenread = BZ2_bzRead(&dbz2err, dpfbz2, new + newpos, ctrl[0]);
    166 		if ((lenread < ctrl[0]) ||
    167 		    ((dbz2err != BZ_OK) && (dbz2err != BZ_STREAM_END)))
    168 			errx(1, "Corrupt patch\n");
    169 
    170 		/* Add old data to diff string */
    171 		for(i=0;i<ctrl[0];i++)
    172 			if((oldpos+i>=0) && (oldpos+i<oldsize))
    173 				new[newpos+i]+=old[oldpos+i];
    174 
    175 		/* Adjust pointers */
    176 		newpos+=ctrl[0];
    177 		oldpos+=ctrl[0];
    178 
    179 		/* Sanity-check */
    180 		if(newpos+ctrl[1]>newsize)
    181 			errx(1,"Corrupt patch\n");
    182 
    183 		/* Read extra string */
    184 		lenread = BZ2_bzRead(&ebz2err, epfbz2, new + newpos, ctrl[1]);
    185 		if ((lenread < ctrl[1]) ||
    186 		    ((ebz2err != BZ_OK) && (ebz2err != BZ_STREAM_END)))
    187 			errx(1, "Corrupt patch\n");
    188 
    189 		/* Adjust pointers */
    190 		newpos+=ctrl[1];
    191 		oldpos+=ctrl[2];
    192 	};
    193 
    194 	/* Clean up the bzip2 reads */
    195 	BZ2_bzReadClose(&cbz2err, cpfbz2);
    196 	BZ2_bzReadClose(&dbz2err, dpfbz2);
    197 	BZ2_bzReadClose(&ebz2err, epfbz2);
    198 	if (fclose(cpf) || fclose(dpf) || fclose(epf))
    199 		err(1, "fclose(%s)", argv[3]);
    200 
    201 	/* Write the new file */
    202 	if(((fd=open(argv[2],O_CREAT|O_TRUNC|O_WRONLY,0666))<0) ||
    203 		(write(fd,new,newsize)!=newsize) || (close(fd)==-1))
    204 		err(1,"%s",argv[2]);
    205 
    206 	free(new);
    207 	free(old);
    208 
    209 	return 0;
    210 }
    211