1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright 2003-2005 Colin Percival 5 * All rights reserved 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted providing that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 18 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY 20 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 24 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 25 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 26 * POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29 #include <sys/types.h> 30 31 #include <bzlib.h> 32 #include <err.h> 33 #include <errno.h> 34 #include <fcntl.h> 35 #include <limits.h> 36 #include <stdint.h> 37 #include <stdio.h> 38 #include <stdlib.h> 39 #include <string.h> 40 #include <unistd.h> 41 #include <sys/mman.h> 42 43 #ifndef O_BINARY 44 #define O_BINARY 0 45 #endif 46 47 #include "divsufsort64.h" 48 #define saidx_t saidx64_t 49 #define divsufsort divsufsort64 50 51 #define MIN(x,y) (((x)<(y)) ? (x) : (y)) 52 53 static off_t matchlen(u_char *old,off_t oldsize,u_char *new,off_t newsize) 54 { 55 off_t i; 56 57 for(i=0;(i<oldsize)&&(i<newsize);i++) 58 if(old[i]!=new[i]) break; 59 60 return i; 61 } 62 63 static off_t search(off_t *I,u_char *old,off_t oldsize, 64 u_char *new,off_t newsize,off_t st,off_t en,off_t *pos) 65 { 66 off_t x,y; 67 68 if(en-st<2) { 69 x=matchlen(old+I[st],oldsize-I[st],new,newsize); 70 y=matchlen(old+I[en],oldsize-I[en],new,newsize); 71 72 if(x>y) { 73 *pos=I[st]; 74 return x; 75 } else { 76 *pos=I[en]; 77 return y; 78 } 79 } 80 81 x=st+(en-st)/2; 82 if(memcmp(old+I[x],new,MIN(oldsize-I[x],newsize))<0) { 83 return search(I,old,oldsize,new,newsize,x,en,pos); 84 } else { 85 return search(I,old,oldsize,new,newsize,st,x,pos); 86 }; 87 } 88 89 static void offtout(off_t x,u_char *buf) 90 { 91 off_t y; 92 93 if(x<0) y=-x; else y=x; 94 95 buf[0]=y%256;y-=buf[0]; 96 y=y/256;buf[1]=y%256;y-=buf[1]; 97 y=y/256;buf[2]=y%256;y-=buf[2]; 98 y=y/256;buf[3]=y%256;y-=buf[3]; 99 y=y/256;buf[4]=y%256;y-=buf[4]; 100 y=y/256;buf[5]=y%256;y-=buf[5]; 101 y=y/256;buf[6]=y%256;y-=buf[6]; 102 y=y/256;buf[7]=y%256; 103 104 if(x<0) buf[7]|=0x80; 105 } 106 107 static void 108 usage(void) 109 { 110 111 fprintf(stderr, "usage: bsdiff oldfile newfile patchfile\n"); 112 exit(1); 113 } 114 115 int main(int argc,char *argv[]) 116 { 117 int fd; 118 u_char *old,*new; 119 off_t oldsize,newsize,xnewsize; 120 saidx_t *I; 121 off_t scan,pos,len; 122 off_t lastscan,lastpos,lastoffset; 123 off_t oldscore,scsc; 124 off_t s,Sf,lenf,Sb,lenb; 125 off_t overlap,Ss,lens; 126 off_t i; 127 off_t dblen,eblen; 128 u_char *db,*eb; 129 u_char buf[8]; 130 u_char header[32]; 131 FILE * pf; 132 BZFILE * pfbz2; 133 int bz2err; 134 135 if (argc != 4) 136 usage(); 137 138 /* Allocate oldsize+1 bytes instead of oldsize bytes to ensure 139 that we never try to malloc(0) and get a NULL pointer */ 140 if(((fd=open(argv[1],O_RDONLY|O_BINARY,0))<0) || 141 ((oldsize=lseek(fd,0,SEEK_END))==-1)) 142 err(1, "%s", argv[1]); 143 144 if (oldsize > SSIZE_MAX || 145 (uintmax_t)oldsize >= SIZE_T_MAX / sizeof(off_t) || 146 oldsize == OFF_MAX) { 147 errno = EFBIG; 148 err(1, "%s", argv[1]); 149 } 150 151 old = mmap(NULL, oldsize+1, PROT_READ, MAP_SHARED, fd, 0); 152 if (old == MAP_FAILED || close(fd) == -1) 153 err(1, "%s", argv[1]); 154 155 if(((I=malloc((oldsize+1)*sizeof(saidx_t)))==NULL)) err(1,NULL); 156 157 if(divsufsort(old, I, oldsize)) err(1, "divsufsort"); 158 159 /* Allocate newsize+1 bytes instead of newsize bytes to ensure 160 that we never try to malloc(0) and get a NULL pointer */ 161 if(((fd=open(argv[2],O_RDONLY|O_BINARY,0))<0) || 162 ((newsize=lseek(fd,0,SEEK_END))==-1)) 163 err(1, "%s", argv[2]); 164 165 if (newsize > SSIZE_MAX || (uintmax_t)newsize >= SIZE_T_MAX || 166 newsize == OFF_MAX) { 167 errno = EFBIG; 168 err(1, "%s", argv[2]); 169 } 170 171 new = mmap(NULL, newsize+1, PROT_READ, MAP_SHARED, fd, 0); 172 if (new == MAP_FAILED || close(fd) == -1) 173 err(1, "%s", argv[2]); 174 175 if(((db=malloc(newsize+1))==NULL) || 176 ((eb=malloc(newsize+1))==NULL)) err(1,NULL); 177 dblen=0; 178 eblen=0; 179 180 /* Create the patch file */ 181 if ((pf = fopen(argv[3], "wb")) == NULL) 182 err(1, "%s", argv[3]); 183 184 /* Header is 185 0 8 "BSDIFF40" 186 8 8 length of bzip2ed ctrl block 187 16 8 length of bzip2ed diff block 188 24 8 length of new file */ 189 /* File is 190 0 32 Header 191 32 ?? Bzip2ed ctrl block 192 ?? ?? Bzip2ed diff block 193 ?? ?? Bzip2ed extra block */ 194 memcpy(header,"BSDIFF40",8); 195 offtout(0, header + 8); 196 offtout(0, header + 16); 197 offtout(newsize, header + 24); 198 if (fwrite(header, 32, 1, pf) != 1) 199 err(1, "fwrite(%s)", argv[3]); 200 201 /* Compute the differences, writing ctrl as we go */ 202 if ((pfbz2 = BZ2_bzWriteOpen(&bz2err, pf, 9, 0, 0)) == NULL) 203 errx(1, "BZ2_bzWriteOpen, bz2err = %d", bz2err); 204 scan=0;len=0;pos=0; 205 lastscan=0;lastpos=0;lastoffset=0; 206 while(scan<newsize) { 207 oldscore=0; 208 209 for(scsc=scan+=len;scan<newsize;scan++) { 210 len=search(I,old,oldsize,new+scan,newsize-scan, 211 0,oldsize-1,&pos); 212 213 for(;scsc<scan+len;scsc++) 214 if((scsc+lastoffset<oldsize) && 215 (old[scsc+lastoffset] == new[scsc])) 216 oldscore++; 217 218 if(((len==oldscore) && (len!=0)) || 219 (len>oldscore+8)) break; 220 221 if((scan+lastoffset<oldsize) && 222 (old[scan+lastoffset] == new[scan])) 223 oldscore--; 224 } 225 226 if((len!=oldscore) || (scan==newsize)) { 227 s=0;Sf=0;lenf=0; 228 for(i=0;(lastscan+i<scan)&&(lastpos+i<oldsize);) { 229 if(old[lastpos+i]==new[lastscan+i]) s++; 230 i++; 231 if(s*2-i>Sf*2-lenf) { Sf=s; lenf=i; } 232 } 233 234 lenb=0; 235 if(scan<newsize) { 236 s=0;Sb=0; 237 for(i=1;(scan>=lastscan+i)&&(pos>=i);i++) { 238 if(old[pos-i]==new[scan-i]) s++; 239 if(s*2-i>Sb*2-lenb) { Sb=s; lenb=i; } 240 } 241 } 242 243 if(lastscan+lenf>scan-lenb) { 244 overlap=(lastscan+lenf)-(scan-lenb); 245 s=0;Ss=0;lens=0; 246 for(i=0;i<overlap;i++) { 247 if(new[lastscan+lenf-overlap+i]== 248 old[lastpos+lenf-overlap+i]) s++; 249 if(new[scan-lenb+i]== 250 old[pos-lenb+i]) s--; 251 if(s>Ss) { Ss=s; lens=i+1; } 252 } 253 254 lenf+=lens-overlap; 255 lenb-=lens; 256 } 257 258 for(i=0;i<lenf;i++) 259 db[dblen+i]=new[lastscan+i]-old[lastpos+i]; 260 for(i=0;i<(scan-lenb)-(lastscan+lenf);i++) 261 eb[eblen+i]=new[lastscan+lenf+i]; 262 263 dblen+=lenf; 264 eblen+=(scan-lenb)-(lastscan+lenf); 265 266 offtout(lenf,buf); 267 BZ2_bzWrite(&bz2err, pfbz2, buf, 8); 268 if (bz2err != BZ_OK) 269 errx(1, "BZ2_bzWrite, bz2err = %d", bz2err); 270 271 offtout((scan-lenb)-(lastscan+lenf),buf); 272 BZ2_bzWrite(&bz2err, pfbz2, buf, 8); 273 if (bz2err != BZ_OK) 274 errx(1, "BZ2_bzWrite, bz2err = %d", bz2err); 275 276 offtout((pos-lenb)-(lastpos+lenf),buf); 277 BZ2_bzWrite(&bz2err, pfbz2, buf, 8); 278 if (bz2err != BZ_OK) 279 errx(1, "BZ2_bzWrite, bz2err = %d", bz2err); 280 281 lastscan=scan-lenb; 282 lastpos=pos-lenb; 283 lastoffset=pos-scan; 284 } 285 } 286 BZ2_bzWriteClose(&bz2err, pfbz2, 0, NULL, NULL); 287 if (bz2err != BZ_OK) 288 errx(1, "BZ2_bzWriteClose, bz2err = %d", bz2err); 289 290 /* Compute size of compressed ctrl data */ 291 if ((len = ftello(pf)) == -1) 292 err(1, "ftello"); 293 offtout(len-32, header + 8); 294 295 /* Write compressed diff data */ 296 if ((pfbz2 = BZ2_bzWriteOpen(&bz2err, pf, 9, 0, 0)) == NULL) 297 errx(1, "BZ2_bzWriteOpen, bz2err = %d", bz2err); 298 BZ2_bzWrite(&bz2err, pfbz2, db, dblen); 299 if (bz2err != BZ_OK) 300 errx(1, "BZ2_bzWrite, bz2err = %d", bz2err); 301 BZ2_bzWriteClose(&bz2err, pfbz2, 0, NULL, NULL); 302 if (bz2err != BZ_OK) 303 errx(1, "BZ2_bzWriteClose, bz2err = %d", bz2err); 304 305 /* Compute size of compressed diff data */ 306 if ((xnewsize = ftello(pf)) == -1) 307 err(1, "ftello"); 308 offtout(xnewsize - len, header + 16); 309 310 /* Write compressed extra data */ 311 if ((pfbz2 = BZ2_bzWriteOpen(&bz2err, pf, 9, 0, 0)) == NULL) 312 errx(1, "BZ2_bzWriteOpen, bz2err = %d", bz2err); 313 BZ2_bzWrite(&bz2err, pfbz2, eb, eblen); 314 if (bz2err != BZ_OK) 315 errx(1, "BZ2_bzWrite, bz2err = %d", bz2err); 316 BZ2_bzWriteClose(&bz2err, pfbz2, 0, NULL, NULL); 317 if (bz2err != BZ_OK) 318 errx(1, "BZ2_bzWriteClose, bz2err = %d", bz2err); 319 320 /* Seek to the beginning, write the header, and close the file */ 321 if (fseeko(pf, 0, SEEK_SET)) 322 err(1, "fseeko"); 323 if (fwrite(header, 32, 1, pf) != 1) 324 err(1, "fwrite(%s)", argv[3]); 325 if (fclose(pf)) 326 err(1, "fclose"); 327 328 /* Free the memory we used */ 329 free(db); 330 free(eb); 331 free(I); 332 munmap(old, oldsize+1); 333 munmap(new, newsize+1); 334 335 return 0; 336 } 337