#ifdef UNSAFE_BUFFERS_BUILD
// TODO(crbug.com/40285824): Remove this and convert code to safer constructs.
#pragma allow_unsafe_buffers
#endif
/*-
* 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/bsdiff/bsdiff.c,v 1.1 2005/08/06 01:59:05 cperciva Exp $");
#endif
#include <sys/types.h>
#include <bzlib.h>
#include <err.h>
#include <fcntl.h>
#include <lzma.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <zlib.h>
#if defined(__APPLE__)
#include <CommonCrypto/CommonDigest.h>
#include <libkern/OSByteOrder.h>
#define htole64(x) OSSwapHostToLittleInt64(x)
#elif defined(__linux__)
#include <endian.h>
#elif defined(_WIN32) && (defined(_M_IX86) || defined(_M_X64))
#define htole64(x) (x)
#else
#error Provide htole64 for this platform
#endif
#define MIN(x,y) (((x)<(y)) ? (x) : (y))
static void split(off_t *I,off_t *V,off_t start,off_t len,off_t h)
{
off_t i,j,k,x,tmp,jj,kk;
if(len<16) {
for(k=start;k<start+len;k+=j) {
j=1;x=V[I[k]+h];
for(i=1;k+i<start+len;i++) {
if(V[I[k+i]+h]<x) {
x=V[I[k+i]+h];
j=0;
};
if(V[I[k+i]+h]==x) {
tmp=I[k+j];I[k+j]=I[k+i];I[k+i]=tmp;
j++;
};
};
for(i=0;i<j;i++) V[I[k+i]]=k+j-1;
if(j==1) I[k]=-1;
};
return;
};
x=V[I[start+len/2]+h];
jj=0;kk=0;
for(i=start;i<start+len;i++) {
if(V[I[i]+h]<x) jj++;
if(V[I[i]+h]==x) kk++;
};
jj+=start;kk+=jj;
i=start;j=0;k=0;
while(i<jj) {
if(V[I[i]+h]<x) {
i++;
} else if(V[I[i]+h]==x) {
tmp=I[i];I[i]=I[jj+j];I[jj+j]=tmp;
j++;
} else {
tmp=I[i];I[i]=I[kk+k];I[kk+k]=tmp;
k++;
};
};
while(jj+j<kk) {
if(V[I[jj+j]+h]==x) {
j++;
} else {
tmp=I[jj+j];I[jj+j]=I[kk+k];I[kk+k]=tmp;
k++;
};
};
if(jj>start) split(I,V,start,jj-start,h);
for(i=0;i<kk-jj;i++) V[I[jj+i]]=kk-1;
if(jj==kk-1) I[jj]=-1;
if(start+len>kk) split(I,V,kk,start+len-kk,h);
}
static void qsufsort(off_t *I,off_t *V,u_char *old,off_t oldsize)
{
off_t buckets[256];
off_t i,h,len;
for(i=0;i<256;i++) buckets[i]=0;
for(i=0;i<oldsize;i++) buckets[old[i]]++;
for(i=1;i<256;i++) buckets[i]+=buckets[i-1];
for(i=255;i>0;i--) buckets[i]=buckets[i-1];
buckets[0]=0;
for(i=0;i<oldsize;i++) I[++buckets[old[i]]]=i;
I[0]=oldsize;
for(i=0;i<oldsize;i++) V[i]=buckets[old[i]];
V[oldsize]=0;
for(i=1;i<256;i++) if(buckets[i]==buckets[i-1]+1) I[buckets[i]]=-1;
I[0]=-1;
for(h=1;I[0]!=-(oldsize+1);h+=h) {
len=0;
for(i=0;i<oldsize+1;) {
if(I[i]<0) {
len-=I[i];
i-=I[i];
} else {
if(len) I[i-len]=-len;
len=V[I[i]]+1-i;
split(I,V,i,len,h);
i+=len;
len=0;
};
};
if(len) I[i-len]=-len;
};
for(i=0;i<oldsize+1;i++) I[V[i]]=i;
}
static off_t matchlen(u_char *old,off_t oldsize,u_char *new,off_t newsize)
{
off_t i;
for(i=0;(i<oldsize)&&(i<newsize);i++)
if(old[i]!=new[i]) break;
return i;
}
static off_t search(off_t *I,u_char *old,off_t oldsize,
u_char *new,off_t newsize,off_t st,off_t en,off_t *pos)
{
off_t x,y;
if(en-st<2) {
x=matchlen(old+I[st],oldsize-I[st],new,newsize);
y=matchlen(old+I[en],oldsize-I[en],new,newsize);
if(x>y) {
*pos=I[st];
return x;
} else {
*pos=I[en];
return y;
}
};
x=st+(en-st)/2;
if(memcmp(old+I[x],new,MIN(oldsize-I[x],newsize))<0) {
return search(I,old,oldsize,new,newsize,x,en,pos);
} else {
return search(I,old,oldsize,new,newsize,st,x,pos);
};
}
static inline void offtout(off_t x,u_char *buf)
{
*((off_t*)buf) = htole64(x);
}
/* zlib provides compress2, which deflates to deflate (zlib) format. This is
* unfortunately distinct from gzip format in that the headers wrapping the
* decompressed data are different. gbspatch reads gzip-compressed data using
* the file-oriented gzread interface, which only supports gzip format.
* compress2gzip is identical to zlib's compress2 except that it produces gzip
* output compatible with gzread. This change is achieved by calling
* deflateInit2 instead of deflateInit and specifying 31 for windowBits;
* numbers greater than 15 cause the addition of a gzip wrapper. */
static int compress2gzip(Bytef *dest, uLongf *destLen,
const Bytef *source, uLong sourceLen, int level)
{
z_stream stream;
int err;
stream.next_in = (Bytef*)source;
stream.avail_in = (uInt)sourceLen;
stream.next_out = dest;
stream.avail_out = (uInt)*destLen;
if ((uLong)stream.avail_out != *destLen) return Z_BUF_ERROR;
stream.zalloc = (alloc_func)0;
stream.zfree = (free_func)0;
stream.opaque = (voidpf)0;
err = deflateInit2(&stream,
level, Z_DEFLATED, 31, 8, Z_DEFAULT_STRATEGY);
if (err != Z_OK) return err;
err = deflate(&stream, Z_FINISH);
if (err != Z_STREAM_END) {
deflateEnd(&stream);
return err == Z_OK ? Z_BUF_ERROR : err;
}
*destLen = stream.total_out;
err = deflateEnd(&stream);
return err;
}
/* Recompress buf of size buf_len using bzip2 or gzip. The smallest version is
* used. The original uncompressed variant may be the smallest. Returns a
* number identifying the encoding, 1 for uncompressed, 2 for bzip2, 3 for
* gzip, and 4 for xz/lzma2. If the original uncompressed variant is not
* smallest, it is freed. The caller must free any buf after this function
* returns. */
static char make_small(u_char **buf, off_t *buf_len)
{
u_char *source = *buf;
off_t source_len = *buf_len;
u_char *bz2, *gz, *lzma;
unsigned int bz2_len;
size_t gz_len, lzma_len, lzma_pos;
int bz2_err, gz_err;
lzma_ret lzma_err;
lzma_check lzma_ck;
char smallest;
smallest = 1;
bz2_len = source_len + 1;
bz2 = malloc(bz2_len);
bz2_err = BZ2_bzBuffToBuffCompress((char*)bz2, &bz2_len, (char*)source,
source_len, 9, 0, 0);
if (bz2_err == BZ_OK) {
if (bz2_len < *buf_len) {
smallest = 2;
*buf = bz2;
*buf_len = bz2_len;
} else {
free(bz2);
bz2 = NULL;
}
} else if (bz2_err == BZ_OUTBUFF_FULL) {
free(bz2);
bz2 = NULL;
} else {
errx(1, "BZ2_bzBuffToBuffCompress: %d", bz2_err);
}
gz_len = source_len + 1;
gz = malloc(gz_len);
gz_err = compress2gzip(gz, &gz_len, source, source_len, 9);
if (gz_err == Z_OK) {
if (gz_len < *buf_len) {
smallest = 3;
*buf = gz;
*buf_len = gz_len;
} else {
free(gz);
gz = NULL;
}
} else if (gz_err == Z_BUF_ERROR) {
free(gz);
gz = NULL;
} else {
errx(1, "compress2gzip: %d", gz_err);
}
lzma_len = source_len + 1;
lzma = malloc(lzma_len);
lzma_pos = 0;
/* Equivalent to the options used by xz -9 -e. */
lzma_ck = LZMA_CHECK_CRC64;
if (!lzma_check_is_supported(lzma_ck))
lzma_ck = LZMA_CHECK_CRC32;
lzma_err = lzma_easy_buffer_encode(9 | LZMA_PRESET_EXTREME,
lzma_ck, NULL,
source, source_len,
lzma, &lzma_pos, lzma_len);
if (lzma_err == LZMA_OK) {
if (lzma_pos < *buf_len) {
smallest = 4;
*buf = lzma;
*buf_len = lzma_pos;
} else {
free(lzma);
lzma = NULL;
}
} else if (lzma_err == LZMA_BUF_ERROR) {
free(lzma);
lzma = NULL;
} else {
errx(1, "lzma_easy_buffer_encode: %d", lzma_err);
}
if (smallest != 1) {
free(source);
}
return smallest;
}
int main(int argc,char *argv[])
{
int fd;
u_char *old,*new;
off_t oldsize,newsize;
off_t *I,*V;
off_t scan,pos,len;
off_t lastscan,lastpos,lastoffset;
off_t oldscore,scsc;
off_t s,Sf,lenf,Sb,lenb;
off_t overlap,Ss,lens;
off_t i;
off_t cblen, dblen, eblen;
u_char *cb, *db, *eb;
u_char header[96];
FILE * pf;
if(argc!=4) errx(1,"usage: %s oldfile newfile patchfile",argv[0]);
/* Allocate oldsize+1 bytes instead of oldsize bytes to ensure
that we never try to malloc(0) and get a NULL pointer */
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(((I=malloc((oldsize+1)*sizeof(off_t)))==NULL) ||
((V=malloc((oldsize+1)*sizeof(off_t)))==NULL)) err(1,NULL);
qsufsort(I,V,old,oldsize);
free(V);
/* Allocate newsize+1 bytes instead of newsize bytes to ensure
that we never try to malloc(0) and get a NULL pointer */
if(((fd=open(argv[2],O_RDONLY,0))<0) ||
((newsize=lseek(fd,0,SEEK_END))==-1) ||
((new=malloc(newsize+1))==NULL) ||
(lseek(fd,0,SEEK_SET)!=0) ||
(read(fd,new,newsize)!=newsize) ||
(close(fd)==-1)) err(1,"%s",argv[2]);
if(((cb=malloc(newsize+1))==NULL) ||
((db=malloc(newsize+1))==NULL) ||
((eb=malloc(newsize+1))==NULL)) err(1,NULL);
cblen=0;
dblen=0;
eblen=0;
/* Create the patch file */
if ((pf = fopen(argv[3], "wb")) == NULL)
err(1, "%s", argv[3]);
/* File format:
0 8 "BSDIFF4G"
8 8 length of compressed control block (x)
16 8 length of compressed diff block (y)
24 8 length of compressed extra block (z)
32 8 length of old file
40 8 length of new file
48 20 SHA1 of old file
68 20 SHA1 of new file
88 1 encoding of control block
89 1 encoding of diff block
90 1 encoding of extra block
91 5 unused
96 x compressed control block
96+x y compressed diff block
96+x+y z compressed extra block
Encodings are 1 (uncompressed), 2 (bzip2), 3 (gzip), and 4 (xz/lzma2).
*/
memset(header, 0, sizeof(header));
if (fwrite(header, sizeof(header), 1, pf) != 1)
err(1, "fwrite(%s)", argv[3]);
memcpy(header, "BSDIFF4G", 8);
offtout(oldsize, header + 32);
offtout(newsize, header + 40);
CC_SHA1(old, oldsize, header + 48);
CC_SHA1(new, newsize, header + 68);
/* Compute the differences */
scan=0;len=0;
lastscan=0;lastpos=0;lastoffset=0;
while(scan<newsize) {
oldscore=0;
for(scsc=scan+=len;scan<newsize;scan++) {
len=search(I,old,oldsize,new+scan,newsize-scan,
0,oldsize,&pos);
for(;scsc<scan+len;scsc++)
if((scsc+lastoffset<oldsize) &&
(old[scsc+lastoffset] == new[scsc]))
oldscore++;
if(((len==oldscore) && (len!=0)) ||
(len>oldscore+8)) break;
if((scan+lastoffset<oldsize) &&
(old[scan+lastoffset] == new[scan]))
oldscore--;
};
if((len!=oldscore) || (scan==newsize)) {
s=0;Sf=0;lenf=0;
for(i=0;(lastscan+i<scan)&&(lastpos+i<oldsize);) {
if(old[lastpos+i]==new[lastscan+i]) s++;
i++;
if(s*2-i>Sf*2-lenf) { Sf=s; lenf=i; };
};
lenb=0;
if(scan<newsize) {
s=0;Sb=0;
for(i=1;(scan>=lastscan+i)&&(pos>=i);i++) {
if(old[pos-i]==new[scan-i]) s++;
if(s*2-i>Sb*2-lenb) { Sb=s; lenb=i; };
};
};
if(lastscan+lenf>scan-lenb) {
overlap=(lastscan+lenf)-(scan-lenb);
s=0;Ss=0;lens=0;
for(i=0;i<overlap;i++) {
if(new[lastscan+lenf-overlap+i]==
old[lastpos+lenf-overlap+i]) s++;
if(new[scan-lenb+i]==
old[pos-lenb+i]) s--;
if(s>Ss) { Ss=s; lens=i+1; };
};
lenf+=lens-overlap;
lenb-=lens;
};
for(i=0;i<lenf;i++)
db[dblen+i]=new[lastscan+i]-old[lastpos+i];
for(i=0;i<(scan-lenb)-(lastscan+lenf);i++)
eb[eblen+i]=new[lastscan+lenf+i];
dblen+=lenf;
eblen+=(scan-lenb)-(lastscan+lenf);
offtout(lenf, cb + cblen);
cblen += 8;
offtout((scan - lenb) - (lastscan + lenf), cb + cblen);
cblen += 8;
offtout((pos - lenb) - (lastpos + lenf), cb + cblen);
cblen += 8;
lastscan=scan-lenb;
lastpos=pos-lenb;
lastoffset=pos-scan;
};
};
header[88] = make_small(&cb, &cblen);
header[89] = make_small(&db, &dblen);
header[90] = make_small(&eb, &eblen);
if (fwrite(cb, 1, cblen, pf) != cblen)
err(1, "fwrite");
if (fwrite(db, 1, dblen, pf) != dblen)
err(1, "fwrite");
if (fwrite(eb, 1, eblen, pf) != eblen)
err(1, "fwrite");
offtout(cblen, header + 8);
offtout(dblen, header + 16);
offtout(eblen, header + 24);
/* Seek to the beginning, write the header, and close the file */
if (fseeko(pf, 0, SEEK_SET))
err(1, "fseeko");
if (fwrite(header, sizeof(header), 1, pf) != 1)
err(1, "fwrite(%s)", argv[3]);
if (fclose(pf))
err(1, "fclose");
/* Free the memory we used */
free(cb);
free(db);
free(eb);
free(I);
free(old);
free(new);
return 0;
}
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