bspatch.c revision 303301
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: stable/10/usr.bin/bsdiff/bspatch/bspatch.c 303301 2016-07-25 14:53:04Z delphij $"); 29 30#include <bzlib.h> 31#include <stdlib.h> 32#include <stdio.h> 33#include <string.h> 34#include <err.h> 35#include <unistd.h> 36#include <fcntl.h> 37 38#ifndef O_BINARY 39#define O_BINARY 0 40#endif 41 42static off_t offtin(u_char *buf) 43{ 44 off_t y; 45 46 y=buf[7]&0x7F; 47 y=y*256;y+=buf[6]; 48 y=y*256;y+=buf[5]; 49 y=y*256;y+=buf[4]; 50 y=y*256;y+=buf[3]; 51 y=y*256;y+=buf[2]; 52 y=y*256;y+=buf[1]; 53 y=y*256;y+=buf[0]; 54 55 if(buf[7]&0x80) y=-y; 56 57 return y; 58} 59 60int main(int argc,char * argv[]) 61{ 62 FILE * f, * cpf, * dpf, * epf; 63 BZFILE * cpfbz2, * dpfbz2, * epfbz2; 64 int cbz2err, dbz2err, ebz2err; 65 int fd; 66 ssize_t oldsize,newsize; 67 ssize_t bzctrllen,bzdatalen; 68 u_char header[32],buf[8]; 69 u_char *old, *new; 70 off_t oldpos,newpos; 71 off_t ctrl[3]; 72 off_t lenread; 73 off_t i; 74 75 if(argc!=4) errx(1,"usage: %s oldfile newfile patchfile\n",argv[0]); 76 77 /* Open patch file */ 78 if ((f = fopen(argv[3], "rb")) == NULL) 79 err(1, "fopen(%s)", argv[3]); 80 81 /* 82 File format: 83 0 8 "BSDIFF40" 84 8 8 X 85 16 8 Y 86 24 8 sizeof(newfile) 87 32 X bzip2(control block) 88 32+X Y bzip2(diff block) 89 32+X+Y ??? bzip2(extra block) 90 with control block a set of triples (x,y,z) meaning "add x bytes 91 from oldfile to x bytes from the diff block; copy y bytes from the 92 extra block; seek forwards in oldfile by z bytes". 93 */ 94 95 /* Read header */ 96 if (fread(header, 1, 32, f) < 32) { 97 if (feof(f)) 98 errx(1, "Corrupt patch\n"); 99 err(1, "fread(%s)", argv[3]); 100 } 101 102 /* Check for appropriate magic */ 103 if (memcmp(header, "BSDIFF40", 8) != 0) 104 errx(1, "Corrupt patch\n"); 105 106 /* Read lengths from header */ 107 bzctrllen=offtin(header+8); 108 bzdatalen=offtin(header+16); 109 newsize=offtin(header+24); 110 if((bzctrllen<0) || (bzdatalen<0) || (newsize<0)) 111 errx(1,"Corrupt patch\n"); 112 113 /* Close patch file and re-open it via libbzip2 at the right places */ 114 if (fclose(f)) 115 err(1, "fclose(%s)", argv[3]); 116 if ((cpf = fopen(argv[3], "rb")) == NULL) 117 err(1, "fopen(%s)", argv[3]); 118 if (fseeko(cpf, 32, SEEK_SET)) 119 err(1, "fseeko(%s, %lld)", argv[3], 120 (long long)32); 121 if ((cpfbz2 = BZ2_bzReadOpen(&cbz2err, cpf, 0, 0, NULL, 0)) == NULL) 122 errx(1, "BZ2_bzReadOpen, bz2err = %d", cbz2err); 123 if ((dpf = fopen(argv[3], "rb")) == NULL) 124 err(1, "fopen(%s)", argv[3]); 125 if (fseeko(dpf, 32 + bzctrllen, SEEK_SET)) 126 err(1, "fseeko(%s, %lld)", argv[3], 127 (long long)(32 + bzctrllen)); 128 if ((dpfbz2 = BZ2_bzReadOpen(&dbz2err, dpf, 0, 0, NULL, 0)) == NULL) 129 errx(1, "BZ2_bzReadOpen, bz2err = %d", dbz2err); 130 if ((epf = fopen(argv[3], "rb")) == NULL) 131 err(1, "fopen(%s)", argv[3]); 132 if (fseeko(epf, 32 + bzctrllen + bzdatalen, SEEK_SET)) 133 err(1, "fseeko(%s, %lld)", argv[3], 134 (long long)(32 + bzctrllen + bzdatalen)); 135 if ((epfbz2 = BZ2_bzReadOpen(&ebz2err, epf, 0, 0, NULL, 0)) == NULL) 136 errx(1, "BZ2_bzReadOpen, bz2err = %d", ebz2err); 137 138 if(((fd=open(argv[1],O_RDONLY|O_BINARY,0))<0) || 139 ((oldsize=lseek(fd,0,SEEK_END))==-1) || 140 ((old=malloc(oldsize+1))==NULL) || 141 (lseek(fd,0,SEEK_SET)!=0) || 142 (read(fd,old,oldsize)!=oldsize) || 143 (close(fd)==-1)) err(1,"%s",argv[1]); 144 if((new=malloc(newsize+1))==NULL) err(1,NULL); 145 146 oldpos=0;newpos=0; 147 while(newpos<newsize) { 148 /* Read control data */ 149 for(i=0;i<=2;i++) { 150 lenread = BZ2_bzRead(&cbz2err, cpfbz2, buf, 8); 151 if ((lenread < 8) || ((cbz2err != BZ_OK) && 152 (cbz2err != BZ_STREAM_END))) 153 errx(1, "Corrupt patch\n"); 154 ctrl[i]=offtin(buf); 155 }; 156 157 /* Sanity-check */ 158 if ((ctrl[0] < 0) || (ctrl[1] < 0)) 159 errx(1,"Corrupt patch\n"); 160 161 /* Sanity-check */ 162 if(newpos+ctrl[0]>newsize) 163 errx(1,"Corrupt patch\n"); 164 165 /* Read diff string */ 166 lenread = BZ2_bzRead(&dbz2err, dpfbz2, new + newpos, ctrl[0]); 167 if ((lenread < ctrl[0]) || 168 ((dbz2err != BZ_OK) && (dbz2err != BZ_STREAM_END))) 169 errx(1, "Corrupt patch\n"); 170 171 /* Add old data to diff string */ 172 for(i=0;i<ctrl[0];i++) 173 if((oldpos+i>=0) && (oldpos+i<oldsize)) 174 new[newpos+i]+=old[oldpos+i]; 175 176 /* Adjust pointers */ 177 newpos+=ctrl[0]; 178 oldpos+=ctrl[0]; 179 180 /* Sanity-check */ 181 if(newpos+ctrl[1]>newsize) 182 errx(1,"Corrupt patch\n"); 183 184 /* Read extra string */ 185 lenread = BZ2_bzRead(&ebz2err, epfbz2, new + newpos, ctrl[1]); 186 if ((lenread < ctrl[1]) || 187 ((ebz2err != BZ_OK) && (ebz2err != BZ_STREAM_END))) 188 errx(1, "Corrupt patch\n"); 189 190 /* Adjust pointers */ 191 newpos+=ctrl[1]; 192 oldpos+=ctrl[2]; 193 }; 194 195 /* Clean up the bzip2 reads */ 196 BZ2_bzReadClose(&cbz2err, cpfbz2); 197 BZ2_bzReadClose(&dbz2err, dpfbz2); 198 BZ2_bzReadClose(&ebz2err, epfbz2); 199 if (fclose(cpf) || fclose(dpf) || fclose(epf)) 200 err(1, "fclose(%s)", argv[3]); 201 202 /* Write the new file */ 203 if(((fd=open(argv[2],O_CREAT|O_TRUNC|O_WRONLY|O_BINARY,0666))<0) || 204 (write(fd,new,newsize)!=newsize) || (close(fd)==-1)) 205 err(1,"%s",argv[2]); 206 207 free(new); 208 free(old); 209 210 return 0; 211} 212