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 #include <sys/cdefs.h> 28 __FBSDID("$FreeBSD$"); 29 30 #include <sys/types.h> 31 32 #include <bzlib.h> 33 #include <err.h> 34 #include <errno.h> 35 #include <fcntl.h> 36 #include <limits.h> 37 #include <stdint.h> 38 #include <stdio.h> 39 #include <stdlib.h> 40 #include <string.h> 41 #include <unistd.h> 42 43 #ifndef O_BINARY 44 #define O_BINARY 0 45 #endif 46 47 #define MIN(x,y) (((x)<(y)) ? (x) : (y)) 48 49 static void split(off_t *I,off_t *V,off_t start,off_t len,off_t h) 50 { 51 off_t i,j,k,x,tmp,jj,kk; 52 53 if(len<16) { 54 for(k=start;k<start+len;k+=j) { 55 j=1;x=V[I[k]+h]; 56 for(i=1;k+i<start+len;i++) { 57 if(V[I[k+i]+h]<x) { 58 x=V[I[k+i]+h]; 59 j=0; 60 }; 61 if(V[I[k+i]+h]==x) { 62 tmp=I[k+j];I[k+j]=I[k+i];I[k+i]=tmp; 63 j++; 64 }; 65 }; 66 for(i=0;i<j;i++) V[I[k+i]]=k+j-1; 67 if(j==1) I[k]=-1; 68 }; 69 return; 70 }; 71 72 x=V[I[start+len/2]+h]; 73 jj=0;kk=0; 74 for(i=start;i<start+len;i++) { 75 if(V[I[i]+h]<x) jj++; 76 if(V[I[i]+h]==x) kk++; 77 }; 78 jj+=start;kk+=jj; 79 80 i=start;j=0;k=0; 81 while(i<jj) { 82 if(V[I[i]+h]<x) { 83 i++; 84 } else if(V[I[i]+h]==x) { 85 tmp=I[i];I[i]=I[jj+j];I[jj+j]=tmp; 86 j++; 87 } else { 88 tmp=I[i];I[i]=I[kk+k];I[kk+k]=tmp; 89 k++; 90 }; 91 }; 92 93 while(jj+j<kk) { 94 if(V[I[jj+j]+h]==x) { 95 j++; 96 } else { 97 tmp=I[jj+j];I[jj+j]=I[kk+k];I[kk+k]=tmp; 98 k++; 99 }; 100 }; 101 102 if(jj>start) split(I,V,start,jj-start,h); 103 104 for(i=0;i<kk-jj;i++) V[I[jj+i]]=kk-1; 105 if(jj==kk-1) I[jj]=-1; 106 107 if(start+len>kk) split(I,V,kk,start+len-kk,h); 108 } 109 110 static void qsufsort(off_t *I,off_t *V,u_char *old,off_t oldsize) 111 { 112 off_t buckets[256]; 113 off_t i,h,len; 114 115 for(i=0;i<256;i++) buckets[i]=0; 116 for(i=0;i<oldsize;i++) buckets[old[i]]++; 117 for(i=1;i<256;i++) buckets[i]+=buckets[i-1]; 118 for(i=255;i>0;i--) buckets[i]=buckets[i-1]; 119 buckets[0]=0; 120 121 for(i=0;i<oldsize;i++) I[++buckets[old[i]]]=i; 122 I[0]=oldsize; 123 for(i=0;i<oldsize;i++) V[i]=buckets[old[i]]; 124 V[oldsize]=0; 125 for(i=1;i<256;i++) if(buckets[i]==buckets[i-1]+1) I[buckets[i]]=-1; 126 I[0]=-1; 127 128 for(h=1;I[0]!=-(oldsize+1);h+=h) { 129 len=0; 130 for(i=0;i<oldsize+1;) { 131 if(I[i]<0) { 132 len-=I[i]; 133 i-=I[i]; 134 } else { 135 if(len) I[i-len]=-len; 136 len=V[I[i]]+1-i; 137 split(I,V,i,len,h); 138 i+=len; 139 len=0; 140 }; 141 }; 142 if(len) I[i-len]=-len; 143 }; 144 145 for(i=0;i<oldsize+1;i++) I[V[i]]=i; 146 } 147 148 static off_t matchlen(u_char *old,off_t oldsize,u_char *new,off_t newsize) 149 { 150 off_t i; 151 152 for(i=0;(i<oldsize)&&(i<newsize);i++) 153 if(old[i]!=new[i]) break; 154 155 return i; 156 } 157 158 static off_t search(off_t *I,u_char *old,off_t oldsize, 159 u_char *new,off_t newsize,off_t st,off_t en,off_t *pos) 160 { 161 off_t x,y; 162 163 if(en-st<2) { 164 x=matchlen(old+I[st],oldsize-I[st],new,newsize); 165 y=matchlen(old+I[en],oldsize-I[en],new,newsize); 166 167 if(x>y) { 168 *pos=I[st]; 169 return x; 170 } else { 171 *pos=I[en]; 172 return y; 173 } 174 }; 175 176 x=st+(en-st)/2; 177 if(memcmp(old+I[x],new,MIN(oldsize-I[x],newsize))<0) { 178 return search(I,old,oldsize,new,newsize,x,en,pos); 179 } else { 180 return search(I,old,oldsize,new,newsize,st,x,pos); 181 }; 182 } 183 184 static void offtout(off_t x,u_char *buf) 185 { 186 off_t y; 187 188 if(x<0) y=-x; else y=x; 189 190 buf[0]=y%256;y-=buf[0]; 191 y=y/256;buf[1]=y%256;y-=buf[1]; 192 y=y/256;buf[2]=y%256;y-=buf[2]; 193 y=y/256;buf[3]=y%256;y-=buf[3]; 194 y=y/256;buf[4]=y%256;y-=buf[4]; 195 y=y/256;buf[5]=y%256;y-=buf[5]; 196 y=y/256;buf[6]=y%256;y-=buf[6]; 197 y=y/256;buf[7]=y%256; 198 199 if(x<0) buf[7]|=0x80; 200 } 201 202 static void 203 usage(void) 204 { 205 206 fprintf(stderr, "usage: bsdiff oldfile newfile patchfile\n"); 207 exit(1); 208 } 209 210 int main(int argc,char *argv[]) 211 { 212 int fd; 213 u_char *old,*new; 214 off_t oldsize,newsize; 215 off_t *I,*V; 216 off_t scan,pos,len; 217 off_t lastscan,lastpos,lastoffset; 218 off_t oldscore,scsc; 219 off_t s,Sf,lenf,Sb,lenb; 220 off_t overlap,Ss,lens; 221 off_t i; 222 off_t dblen,eblen; 223 u_char *db,*eb; 224 u_char buf[8]; 225 u_char header[32]; 226 FILE * pf; 227 BZFILE * pfbz2; 228 int bz2err; 229 230 if (argc != 4) 231 usage(); 232 233 /* Allocate oldsize+1 bytes instead of oldsize bytes to ensure 234 that we never try to malloc(0) and get a NULL pointer */ 235 if(((fd=open(argv[1],O_RDONLY|O_BINARY,0))<0) || 236 ((oldsize=lseek(fd,0,SEEK_END))==-1)) 237 err(1, "%s", argv[1]); 238 239 if (oldsize > SSIZE_MAX || 240 (uintmax_t)oldsize >= SIZE_T_MAX / sizeof(off_t) || 241 oldsize == OFF_MAX) { 242 errno = EFBIG; 243 err(1, "%s", argv[1]); 244 } 245 246 if (((old=malloc(oldsize+1))==NULL) || 247 (lseek(fd,0,SEEK_SET)!=0) || 248 (read(fd,old,oldsize)!=oldsize) || 249 (close(fd)==-1)) err(1,"%s",argv[1]); 250 251 if(((I=malloc((oldsize+1)*sizeof(off_t)))==NULL) || 252 ((V=malloc((oldsize+1)*sizeof(off_t)))==NULL)) err(1,NULL); 253 254 qsufsort(I,V,old,oldsize); 255 256 free(V); 257 258 /* Allocate newsize+1 bytes instead of newsize bytes to ensure 259 that we never try to malloc(0) and get a NULL pointer */ 260 if(((fd=open(argv[2],O_RDONLY|O_BINARY,0))<0) || 261 ((newsize=lseek(fd,0,SEEK_END))==-1)) 262 err(1, "%s", argv[2]); 263 264 if (newsize > SSIZE_MAX || (uintmax_t)newsize >= SIZE_T_MAX || 265 newsize == OFF_MAX) { 266 errno = EFBIG; 267 err(1, "%s", argv[2]); 268 } 269 270 if (((new=malloc(newsize+1))==NULL) || 271 (lseek(fd,0,SEEK_SET)!=0) || 272 (read(fd,new,newsize)!=newsize) || 273 (close(fd)==-1)) err(1,"%s",argv[2]); 274 275 if(((db=malloc(newsize+1))==NULL) || 276 ((eb=malloc(newsize+1))==NULL)) err(1,NULL); 277 dblen=0; 278 eblen=0; 279 280 /* Create the patch file */ 281 if ((pf = fopen(argv[3], "wb")) == NULL) 282 err(1, "%s", argv[3]); 283 284 /* Header is 285 0 8 "BSDIFF40" 286 8 8 length of bzip2ed ctrl block 287 16 8 length of bzip2ed diff block 288 24 8 length of new file */ 289 /* File is 290 0 32 Header 291 32 ?? Bzip2ed ctrl block 292 ?? ?? Bzip2ed diff block 293 ?? ?? Bzip2ed extra block */ 294 memcpy(header,"BSDIFF40",8); 295 offtout(0, header + 8); 296 offtout(0, header + 16); 297 offtout(newsize, header + 24); 298 if (fwrite(header, 32, 1, pf) != 1) 299 err(1, "fwrite(%s)", argv[3]); 300 301 /* Compute the differences, writing ctrl as we go */ 302 if ((pfbz2 = BZ2_bzWriteOpen(&bz2err, pf, 9, 0, 0)) == NULL) 303 errx(1, "BZ2_bzWriteOpen, bz2err = %d", bz2err); 304 scan=0;len=0;pos=0; 305 lastscan=0;lastpos=0;lastoffset=0; 306 while(scan<newsize) { 307 oldscore=0; 308 309 for(scsc=scan+=len;scan<newsize;scan++) { 310 len=search(I,old,oldsize,new+scan,newsize-scan, 311 0,oldsize,&pos); 312 313 for(;scsc<scan+len;scsc++) 314 if((scsc+lastoffset<oldsize) && 315 (old[scsc+lastoffset] == new[scsc])) 316 oldscore++; 317 318 if(((len==oldscore) && (len!=0)) || 319 (len>oldscore+8)) break; 320 321 if((scan+lastoffset<oldsize) && 322 (old[scan+lastoffset] == new[scan])) 323 oldscore--; 324 }; 325 326 if((len!=oldscore) || (scan==newsize)) { 327 s=0;Sf=0;lenf=0; 328 for(i=0;(lastscan+i<scan)&&(lastpos+i<oldsize);) { 329 if(old[lastpos+i]==new[lastscan+i]) s++; 330 i++; 331 if(s*2-i>Sf*2-lenf) { Sf=s; lenf=i; }; 332 }; 333 334 lenb=0; 335 if(scan<newsize) { 336 s=0;Sb=0; 337 for(i=1;(scan>=lastscan+i)&&(pos>=i);i++) { 338 if(old[pos-i]==new[scan-i]) s++; 339 if(s*2-i>Sb*2-lenb) { Sb=s; lenb=i; }; 340 }; 341 }; 342 343 if(lastscan+lenf>scan-lenb) { 344 overlap=(lastscan+lenf)-(scan-lenb); 345 s=0;Ss=0;lens=0; 346 for(i=0;i<overlap;i++) { 347 if(new[lastscan+lenf-overlap+i]== 348 old[lastpos+lenf-overlap+i]) s++; 349 if(new[scan-lenb+i]== 350 old[pos-lenb+i]) s--; 351 if(s>Ss) { Ss=s; lens=i+1; }; 352 }; 353 354 lenf+=lens-overlap; 355 lenb-=lens; 356 }; 357 358 for(i=0;i<lenf;i++) 359 db[dblen+i]=new[lastscan+i]-old[lastpos+i]; 360 for(i=0;i<(scan-lenb)-(lastscan+lenf);i++) 361 eb[eblen+i]=new[lastscan+lenf+i]; 362 363 dblen+=lenf; 364 eblen+=(scan-lenb)-(lastscan+lenf); 365 366 offtout(lenf,buf); 367 BZ2_bzWrite(&bz2err, pfbz2, buf, 8); 368 if (bz2err != BZ_OK) 369 errx(1, "BZ2_bzWrite, bz2err = %d", bz2err); 370 371 offtout((scan-lenb)-(lastscan+lenf),buf); 372 BZ2_bzWrite(&bz2err, pfbz2, buf, 8); 373 if (bz2err != BZ_OK) 374 errx(1, "BZ2_bzWrite, bz2err = %d", bz2err); 375 376 offtout((pos-lenb)-(lastpos+lenf),buf); 377 BZ2_bzWrite(&bz2err, pfbz2, buf, 8); 378 if (bz2err != BZ_OK) 379 errx(1, "BZ2_bzWrite, bz2err = %d", bz2err); 380 381 lastscan=scan-lenb; 382 lastpos=pos-lenb; 383 lastoffset=pos-scan; 384 }; 385 }; 386 BZ2_bzWriteClose(&bz2err, pfbz2, 0, NULL, NULL); 387 if (bz2err != BZ_OK) 388 errx(1, "BZ2_bzWriteClose, bz2err = %d", bz2err); 389 390 /* Compute size of compressed ctrl data */ 391 if ((len = ftello(pf)) == -1) 392 err(1, "ftello"); 393 offtout(len-32, header + 8); 394 395 /* Write compressed diff data */ 396 if ((pfbz2 = BZ2_bzWriteOpen(&bz2err, pf, 9, 0, 0)) == NULL) 397 errx(1, "BZ2_bzWriteOpen, bz2err = %d", bz2err); 398 BZ2_bzWrite(&bz2err, pfbz2, db, dblen); 399 if (bz2err != BZ_OK) 400 errx(1, "BZ2_bzWrite, bz2err = %d", bz2err); 401 BZ2_bzWriteClose(&bz2err, pfbz2, 0, NULL, NULL); 402 if (bz2err != BZ_OK) 403 errx(1, "BZ2_bzWriteClose, bz2err = %d", bz2err); 404 405 /* Compute size of compressed diff data */ 406 if ((newsize = ftello(pf)) == -1) 407 err(1, "ftello"); 408 offtout(newsize - len, header + 16); 409 410 /* Write compressed extra data */ 411 if ((pfbz2 = BZ2_bzWriteOpen(&bz2err, pf, 9, 0, 0)) == NULL) 412 errx(1, "BZ2_bzWriteOpen, bz2err = %d", bz2err); 413 BZ2_bzWrite(&bz2err, pfbz2, eb, eblen); 414 if (bz2err != BZ_OK) 415 errx(1, "BZ2_bzWrite, bz2err = %d", bz2err); 416 BZ2_bzWriteClose(&bz2err, pfbz2, 0, NULL, NULL); 417 if (bz2err != BZ_OK) 418 errx(1, "BZ2_bzWriteClose, bz2err = %d", bz2err); 419 420 /* Seek to the beginning, write the header, and close the file */ 421 if (fseeko(pf, 0, SEEK_SET)) 422 err(1, "fseeko"); 423 if (fwrite(header, 32, 1, pf) != 1) 424 err(1, "fwrite(%s)", argv[3]); 425 if (fclose(pf)) 426 err(1, "fclose"); 427 428 /* Free the memory we used */ 429 free(db); 430 free(eb); 431 free(I); 432 free(old); 433 free(new); 434 435 return 0; 436 } 437