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/bsdiff/bsdiff.c,v 1.1 2005/08/06 01:59:05 cperciva Exp $"); 29 #endif 30 31 #include <sys/types.h> 32 33 #include <bzlib.h> 34 #include <err.h> 35 #include <fcntl.h> 36 #include <lzma.h> 37 #include <stdio.h> 38 #include <stdlib.h> 39 #include <string.h> 40 #include <unistd.h> 41 #include <zlib.h> 42 43 #if defined(__APPLE__) 44 #include <libkern/OSByteOrder.h> 45 #define htole64(x) OSSwapHostToLittleInt64(x) 46 #elif defined(__linux__) 47 #include <endian.h> 48 #elif defined(_WIN32) && (defined(_M_IX86) || defined(_M_X64)) 49 #define htole64(x) (x) 50 #else 51 #error Provide htole64 for this platform 52 #endif 53 54 #include "chrome/installer/mac/third_party/bsdiff/sha1_adapter.h" 55 56 #define MIN(x,y) (((x)<(y)) ? (x) : (y)) 57 58 static void split(off_t *I,off_t *V,off_t start,off_t len,off_t h) 59 { 60 off_t i,j,k,x,tmp,jj,kk; 61 62 if(len<16) { 63 for(k=start;k<start+len;k+=j) { 64 j=1;x=V[I[k]+h]; 65 for(i=1;k+i<start+len;i++) { 66 if(V[I[k+i]+h]<x) { 67 x=V[I[k+i]+h]; 68 j=0; 69 }; 70 if(V[I[k+i]+h]==x) { 71 tmp=I[k+j];I[k+j]=I[k+i];I[k+i]=tmp; 72 j++; 73 }; 74 }; 75 for(i=0;i<j;i++) V[I[k+i]]=k+j-1; 76 if(j==1) I[k]=-1; 77 }; 78 return; 79 }; 80 81 x=V[I[start+len/2]+h]; 82 jj=0;kk=0; 83 for(i=start;i<start+len;i++) { 84 if(V[I[i]+h]<x) jj++; 85 if(V[I[i]+h]==x) kk++; 86 }; 87 jj+=start;kk+=jj; 88 89 i=start;j=0;k=0; 90 while(i<jj) { 91 if(V[I[i]+h]<x) { 92 i++; 93 } else if(V[I[i]+h]==x) { 94 tmp=I[i];I[i]=I[jj+j];I[jj+j]=tmp; 95 j++; 96 } else { 97 tmp=I[i];I[i]=I[kk+k];I[kk+k]=tmp; 98 k++; 99 }; 100 }; 101 102 while(jj+j<kk) { 103 if(V[I[jj+j]+h]==x) { 104 j++; 105 } else { 106 tmp=I[jj+j];I[jj+j]=I[kk+k];I[kk+k]=tmp; 107 k++; 108 }; 109 }; 110 111 if(jj>start) split(I,V,start,jj-start,h); 112 113 for(i=0;i<kk-jj;i++) V[I[jj+i]]=kk-1; 114 if(jj==kk-1) I[jj]=-1; 115 116 if(start+len>kk) split(I,V,kk,start+len-kk,h); 117 } 118 119 static void qsufsort(off_t *I,off_t *V,u_char *old,off_t oldsize) 120 { 121 off_t buckets[256]; 122 off_t i,h,len; 123 124 for(i=0;i<256;i++) buckets[i]=0; 125 for(i=0;i<oldsize;i++) buckets[old[i]]++; 126 for(i=1;i<256;i++) buckets[i]+=buckets[i-1]; 127 for(i=255;i>0;i--) buckets[i]=buckets[i-1]; 128 buckets[0]=0; 129 130 for(i=0;i<oldsize;i++) I[++buckets[old[i]]]=i; 131 I[0]=oldsize; 132 for(i=0;i<oldsize;i++) V[i]=buckets[old[i]]; 133 V[oldsize]=0; 134 for(i=1;i<256;i++) if(buckets[i]==buckets[i-1]+1) I[buckets[i]]=-1; 135 I[0]=-1; 136 137 for(h=1;I[0]!=-(oldsize+1);h+=h) { 138 len=0; 139 for(i=0;i<oldsize+1;) { 140 if(I[i]<0) { 141 len-=I[i]; 142 i-=I[i]; 143 } else { 144 if(len) I[i-len]=-len; 145 len=V[I[i]]+1-i; 146 split(I,V,i,len,h); 147 i+=len; 148 len=0; 149 }; 150 }; 151 if(len) I[i-len]=-len; 152 }; 153 154 for(i=0;i<oldsize+1;i++) I[V[i]]=i; 155 } 156 157 static off_t matchlen(u_char *old,off_t oldsize,u_char *new,off_t newsize) 158 { 159 off_t i; 160 161 for(i=0;(i<oldsize)&&(i<newsize);i++) 162 if(old[i]!=new[i]) break; 163 164 return i; 165 } 166 167 static off_t search(off_t *I,u_char *old,off_t oldsize, 168 u_char *new,off_t newsize,off_t st,off_t en,off_t *pos) 169 { 170 off_t x,y; 171 172 if(en-st<2) { 173 x=matchlen(old+I[st],oldsize-I[st],new,newsize); 174 y=matchlen(old+I[en],oldsize-I[en],new,newsize); 175 176 if(x>y) { 177 *pos=I[st]; 178 return x; 179 } else { 180 *pos=I[en]; 181 return y; 182 } 183 }; 184 185 x=st+(en-st)/2; 186 if(memcmp(old+I[x],new,MIN(oldsize-I[x],newsize))<0) { 187 return search(I,old,oldsize,new,newsize,x,en,pos); 188 } else { 189 return search(I,old,oldsize,new,newsize,st,x,pos); 190 }; 191 } 192 193 static inline void offtout(off_t x,u_char *buf) 194 { 195 *((off_t*)buf) = htole64(x); 196 } 197 198 /* zlib provides compress2, which deflates to deflate (zlib) format. This is 199 * unfortunately distinct from gzip format in that the headers wrapping the 200 * decompressed data are different. gbspatch reads gzip-compressed data using 201 * the file-oriented gzread interface, which only supports gzip format. 202 * compress2gzip is identical to zlib's compress2 except that it produces gzip 203 * output compatible with gzread. This change is achieved by calling 204 * deflateInit2 instead of deflateInit and specifying 31 for windowBits; 205 * numbers greater than 15 cause the addition of a gzip wrapper. */ 206 static int compress2gzip(Bytef *dest, uLongf *destLen, 207 const Bytef *source, uLong sourceLen, int level) 208 { 209 z_stream stream; 210 int err; 211 212 stream.next_in = (Bytef*)source; 213 stream.avail_in = (uInt)sourceLen; 214 215 stream.next_out = dest; 216 stream.avail_out = (uInt)*destLen; 217 if ((uLong)stream.avail_out != *destLen) return Z_BUF_ERROR; 218 219 stream.zalloc = (alloc_func)0; 220 stream.zfree = (free_func)0; 221 stream.opaque = (voidpf)0; 222 223 err = deflateInit2(&stream, 224 level, Z_DEFLATED, 31, 8, Z_DEFAULT_STRATEGY); 225 if (err != Z_OK) return err; 226 227 err = deflate(&stream, Z_FINISH); 228 if (err != Z_STREAM_END) { 229 deflateEnd(&stream); 230 return err == Z_OK ? Z_BUF_ERROR : err; 231 } 232 *destLen = stream.total_out; 233 234 err = deflateEnd(&stream); 235 return err; 236 } 237 238 /* Recompress buf of size buf_len using bzip2 or gzip. The smallest version is 239 * used. The original uncompressed variant may be the smallest. Returns a 240 * number identifying the encoding, 1 for uncompressed, 2 for bzip2, 3 for 241 * gzip, and 4 for xz/lzma2. If the original uncompressed variant is not 242 * smallest, it is freed. The caller must free any buf after this function 243 * returns. */ 244 static char make_small(u_char **buf, off_t *buf_len) 245 { 246 u_char *source = *buf; 247 off_t source_len = *buf_len; 248 u_char *bz2, *gz, *lzma; 249 unsigned int bz2_len; 250 size_t gz_len, lzma_len, lzma_pos; 251 int bz2_err, gz_err; 252 lzma_ret lzma_err; 253 lzma_check lzma_ck; 254 char smallest; 255 256 smallest = 1; 257 258 bz2_len = source_len + 1; 259 bz2 = malloc(bz2_len); 260 bz2_err = BZ2_bzBuffToBuffCompress((char*)bz2, &bz2_len, (char*)source, 261 source_len, 9, 0, 0); 262 if (bz2_err == BZ_OK) { 263 if (bz2_len < *buf_len) { 264 smallest = 2; 265 *buf = bz2; 266 *buf_len = bz2_len; 267 } else { 268 free(bz2); 269 bz2 = NULL; 270 } 271 } else if (bz2_err == BZ_OUTBUFF_FULL) { 272 free(bz2); 273 bz2 = NULL; 274 } else { 275 errx(1, "BZ2_bzBuffToBuffCompress: %d", bz2_err); 276 } 277 278 gz_len = source_len + 1; 279 gz = malloc(gz_len); 280 gz_err = compress2gzip(gz, &gz_len, source, source_len, 9); 281 if (gz_err == Z_OK) { 282 if (gz_len < *buf_len) { 283 smallest = 3; 284 *buf = gz; 285 *buf_len = gz_len; 286 } else { 287 free(gz); 288 gz = NULL; 289 } 290 } else if (gz_err == Z_BUF_ERROR) { 291 free(gz); 292 gz = NULL; 293 } else { 294 errx(1, "compress2gzip: %d", gz_err); 295 } 296 297 lzma_len = source_len + 1; 298 lzma = malloc(lzma_len); 299 lzma_pos = 0; 300 301 /* Equivalent to the options used by xz -9 -e. */ 302 lzma_ck = LZMA_CHECK_CRC64; 303 if (!lzma_check_is_supported(lzma_ck)) 304 lzma_ck = LZMA_CHECK_CRC32; 305 lzma_err = lzma_easy_buffer_encode(9 | LZMA_PRESET_EXTREME, 306 lzma_ck, NULL, 307 source, source_len, 308 lzma, &lzma_pos, lzma_len); 309 if (lzma_err == LZMA_OK) { 310 if (lzma_pos < *buf_len) { 311 smallest = 4; 312 *buf = lzma; 313 *buf_len = lzma_pos; 314 } else { 315 free(lzma); 316 lzma = NULL; 317 } 318 } else if (lzma_err == LZMA_BUF_ERROR) { 319 free(lzma); 320 lzma = NULL; 321 } else { 322 errx(1, "lzma_easy_buffer_encode: %d", lzma_err); 323 } 324 325 if (smallest != 1) { 326 free(source); 327 } 328 329 return smallest; 330 } 331 332 int main(int argc,char *argv[]) 333 { 334 int fd; 335 u_char *old,*new; 336 off_t oldsize,newsize; 337 off_t *I,*V; 338 off_t scan,pos,len; 339 off_t lastscan,lastpos,lastoffset; 340 off_t oldscore,scsc; 341 off_t s,Sf,lenf,Sb,lenb; 342 off_t overlap,Ss,lens; 343 off_t i; 344 off_t cblen, dblen, eblen; 345 u_char *cb, *db, *eb; 346 u_char header[96]; 347 FILE * pf; 348 349 if(argc!=4) errx(1,"usage: %s oldfile newfile patchfile",argv[0]); 350 351 /* Allocate oldsize+1 bytes instead of oldsize bytes to ensure 352 that we never try to malloc(0) and get a NULL pointer */ 353 if(((fd=open(argv[1],O_RDONLY,0))<0) || 354 ((oldsize=lseek(fd,0,SEEK_END))==-1) || 355 ((old=malloc(oldsize+1))==NULL) || 356 (lseek(fd,0,SEEK_SET)!=0) || 357 (read(fd,old,oldsize)!=oldsize) || 358 (close(fd)==-1)) err(1,"%s",argv[1]); 359 360 if(((I=malloc((oldsize+1)*sizeof(off_t)))==NULL) || 361 ((V=malloc((oldsize+1)*sizeof(off_t)))==NULL)) err(1,NULL); 362 363 qsufsort(I,V,old,oldsize); 364 365 free(V); 366 367 /* Allocate newsize+1 bytes instead of newsize bytes to ensure 368 that we never try to malloc(0) and get a NULL pointer */ 369 if(((fd=open(argv[2],O_RDONLY,0))<0) || 370 ((newsize=lseek(fd,0,SEEK_END))==-1) || 371 ((new=malloc(newsize+1))==NULL) || 372 (lseek(fd,0,SEEK_SET)!=0) || 373 (read(fd,new,newsize)!=newsize) || 374 (close(fd)==-1)) err(1,"%s",argv[2]); 375 376 if(((cb=malloc(newsize+1))==NULL) || 377 ((db=malloc(newsize+1))==NULL) || 378 ((eb=malloc(newsize+1))==NULL)) err(1,NULL); 379 cblen=0; 380 dblen=0; 381 eblen=0; 382 383 /* Create the patch file */ 384 if ((pf = fopen(argv[3], "wb")) == NULL) 385 err(1, "%s", argv[3]); 386 387 /* File format: 388 0 8 "BSDIFF4G" 389 8 8 length of compressed control block (x) 390 16 8 length of compressed diff block (y) 391 24 8 length of compressed extra block (z) 392 32 8 length of old file 393 40 8 length of new file 394 48 20 SHA1 of old file 395 68 20 SHA1 of new file 396 88 1 encoding of control block 397 89 1 encoding of diff block 398 90 1 encoding of extra block 399 91 5 unused 400 96 x compressed control block 401 96+x y compressed diff block 402 96+x+y z compressed extra block 403 Encodings are 1 (uncompressed), 2 (bzip2), 3 (gzip), and 4 (xz/lzma2). 404 */ 405 406 memset(header, 0, sizeof(header)); 407 if (fwrite(header, sizeof(header), 1, pf) != 1) 408 err(1, "fwrite(%s)", argv[3]); 409 memcpy(header, "BSDIFF4G", 8); 410 offtout(oldsize, header + 32); 411 offtout(newsize, header + 40); 412 SHA1(old, oldsize, header + 48); 413 SHA1(new, newsize, header + 68); 414 415 /* Compute the differences */ 416 scan=0;len=0; 417 lastscan=0;lastpos=0;lastoffset=0; 418 while(scan<newsize) { 419 oldscore=0; 420 421 for(scsc=scan+=len;scan<newsize;scan++) { 422 len=search(I,old,oldsize,new+scan,newsize-scan, 423 0,oldsize,&pos); 424 425 for(;scsc<scan+len;scsc++) 426 if((scsc+lastoffset<oldsize) && 427 (old[scsc+lastoffset] == new[scsc])) 428 oldscore++; 429 430 if(((len==oldscore) && (len!=0)) || 431 (len>oldscore+8)) break; 432 433 if((scan+lastoffset<oldsize) && 434 (old[scan+lastoffset] == new[scan])) 435 oldscore--; 436 }; 437 438 if((len!=oldscore) || (scan==newsize)) { 439 s=0;Sf=0;lenf=0; 440 for(i=0;(lastscan+i<scan)&&(lastpos+i<oldsize);) { 441 if(old[lastpos+i]==new[lastscan+i]) s++; 442 i++; 443 if(s*2-i>Sf*2-lenf) { Sf=s; lenf=i; }; 444 }; 445 446 lenb=0; 447 if(scan<newsize) { 448 s=0;Sb=0; 449 for(i=1;(scan>=lastscan+i)&&(pos>=i);i++) { 450 if(old[pos-i]==new[scan-i]) s++; 451 if(s*2-i>Sb*2-lenb) { Sb=s; lenb=i; }; 452 }; 453 }; 454 455 if(lastscan+lenf>scan-lenb) { 456 overlap=(lastscan+lenf)-(scan-lenb); 457 s=0;Ss=0;lens=0; 458 for(i=0;i<overlap;i++) { 459 if(new[lastscan+lenf-overlap+i]== 460 old[lastpos+lenf-overlap+i]) s++; 461 if(new[scan-lenb+i]== 462 old[pos-lenb+i]) s--; 463 if(s>Ss) { Ss=s; lens=i+1; }; 464 }; 465 466 lenf+=lens-overlap; 467 lenb-=lens; 468 }; 469 470 for(i=0;i<lenf;i++) 471 db[dblen+i]=new[lastscan+i]-old[lastpos+i]; 472 for(i=0;i<(scan-lenb)-(lastscan+lenf);i++) 473 eb[eblen+i]=new[lastscan+lenf+i]; 474 475 dblen+=lenf; 476 eblen+=(scan-lenb)-(lastscan+lenf); 477 478 offtout(lenf, cb + cblen); 479 cblen += 8; 480 481 offtout((scan - lenb) - (lastscan + lenf), cb + cblen); 482 cblen += 8; 483 484 offtout((pos - lenb) - (lastpos + lenf), cb + cblen); 485 cblen += 8; 486 487 lastscan=scan-lenb; 488 lastpos=pos-lenb; 489 lastoffset=pos-scan; 490 }; 491 }; 492 493 header[88] = make_small(&cb, &cblen); 494 header[89] = make_small(&db, &dblen); 495 header[90] = make_small(&eb, &eblen); 496 497 if (fwrite(cb, 1, cblen, pf) != cblen) 498 err(1, "fwrite"); 499 if (fwrite(db, 1, dblen, pf) != dblen) 500 err(1, "fwrite"); 501 if (fwrite(eb, 1, eblen, pf) != eblen) 502 err(1, "fwrite"); 503 504 offtout(cblen, header + 8); 505 offtout(dblen, header + 16); 506 offtout(eblen, header + 24); 507 508 /* Seek to the beginning, write the header, and close the file */ 509 if (fseeko(pf, 0, SEEK_SET)) 510 err(1, "fseeko"); 511 if (fwrite(header, sizeof(header), 1, pf) != 1) 512 err(1, "fwrite(%s)", argv[3]); 513 if (fclose(pf)) 514 err(1, "fclose"); 515 516 /* Free the memory we used */ 517 free(cb); 518 free(db); 519 free(eb); 520 free(I); 521 free(old); 522 free(new); 523 524 return 0; 525 } 526
