bspatch.c revision 306214
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 306214 2016-09-22 21:14:00Z emaste $"); 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 60static void 61usage(void) 62{ 63 64 fprintf(stderr, "usage: bspatch oldfile newfile patchfile\n"); 65 exit(1); 66} 67 68int main(int argc,char * argv[]) 69{ 70 FILE * f, * cpf, * dpf, * epf; 71 BZFILE * cpfbz2, * dpfbz2, * epfbz2; 72 int cbz2err, dbz2err, ebz2err; 73 int fd; 74 ssize_t oldsize,newsize; 75 ssize_t bzctrllen,bzdatalen; 76 u_char header[32],buf[8]; 77 u_char *old, *new; 78 off_t oldpos,newpos; 79 off_t ctrl[3]; 80 off_t lenread; 81 off_t i; 82 83 if (argc != 4) 84 usage(); 85 86 /* Open patch file */ 87 if ((f = fopen(argv[3], "rb")) == NULL) 88 err(1, "fopen(%s)", argv[3]); 89 90 /* 91 File format: 92 0 8 "BSDIFF40" 93 8 8 X 94 16 8 Y 95 24 8 sizeof(newfile) 96 32 X bzip2(control block) 97 32+X Y bzip2(diff block) 98 32+X+Y ??? bzip2(extra block) 99 with control block a set of triples (x,y,z) meaning "add x bytes 100 from oldfile to x bytes from the diff block; copy y bytes from the 101 extra block; seek forwards in oldfile by z bytes". 102 */ 103 104 /* Read header */ 105 if (fread(header, 1, 32, f) < 32) { 106 if (feof(f)) 107 errx(1, "Corrupt patch\n"); 108 err(1, "fread(%s)", argv[3]); 109 } 110 111 /* Check for appropriate magic */ 112 if (memcmp(header, "BSDIFF40", 8) != 0) 113 errx(1, "Corrupt patch\n"); 114 115 /* Read lengths from header */ 116 bzctrllen=offtin(header+8); 117 bzdatalen=offtin(header+16); 118 newsize=offtin(header+24); 119 if((bzctrllen<0) || (bzdatalen<0) || (newsize<0)) 120 errx(1,"Corrupt patch\n"); 121 122 /* Close patch file and re-open it via libbzip2 at the right places */ 123 if (fclose(f)) 124 err(1, "fclose(%s)", argv[3]); 125 if ((cpf = fopen(argv[3], "rb")) == NULL) 126 err(1, "fopen(%s)", argv[3]); 127 if (fseeko(cpf, 32, SEEK_SET)) 128 err(1, "fseeko(%s, %lld)", argv[3], 129 (long long)32); 130 if ((cpfbz2 = BZ2_bzReadOpen(&cbz2err, cpf, 0, 0, NULL, 0)) == NULL) 131 errx(1, "BZ2_bzReadOpen, bz2err = %d", cbz2err); 132 if ((dpf = fopen(argv[3], "rb")) == NULL) 133 err(1, "fopen(%s)", argv[3]); 134 if (fseeko(dpf, 32 + bzctrllen, SEEK_SET)) 135 err(1, "fseeko(%s, %lld)", argv[3], 136 (long long)(32 + bzctrllen)); 137 if ((dpfbz2 = BZ2_bzReadOpen(&dbz2err, dpf, 0, 0, NULL, 0)) == NULL) 138 errx(1, "BZ2_bzReadOpen, bz2err = %d", dbz2err); 139 if ((epf = fopen(argv[3], "rb")) == NULL) 140 err(1, "fopen(%s)", argv[3]); 141 if (fseeko(epf, 32 + bzctrllen + bzdatalen, SEEK_SET)) 142 err(1, "fseeko(%s, %lld)", argv[3], 143 (long long)(32 + bzctrllen + bzdatalen)); 144 if ((epfbz2 = BZ2_bzReadOpen(&ebz2err, epf, 0, 0, NULL, 0)) == NULL) 145 errx(1, "BZ2_bzReadOpen, bz2err = %d", ebz2err); 146 147 if(((fd=open(argv[1],O_RDONLY|O_BINARY,0))<0) || 148 ((oldsize=lseek(fd,0,SEEK_END))==-1) || 149 ((old=malloc(oldsize+1))==NULL) || 150 (lseek(fd,0,SEEK_SET)!=0) || 151 (read(fd,old,oldsize)!=oldsize) || 152 (close(fd)==-1)) err(1,"%s",argv[1]); 153 if((new=malloc(newsize+1))==NULL) err(1,NULL); 154 155 oldpos=0;newpos=0; 156 while(newpos<newsize) { 157 /* Read control data */ 158 for(i=0;i<=2;i++) { 159 lenread = BZ2_bzRead(&cbz2err, cpfbz2, buf, 8); 160 if ((lenread < 8) || ((cbz2err != BZ_OK) && 161 (cbz2err != BZ_STREAM_END))) 162 errx(1, "Corrupt patch\n"); 163 ctrl[i]=offtin(buf); 164 } 165 166 /* Sanity-check */ 167 if ((ctrl[0] < 0) || (ctrl[1] < 0)) 168 errx(1,"Corrupt patch\n"); 169 170 /* Sanity-check */ 171 if(newpos+ctrl[0]>newsize) 172 errx(1,"Corrupt patch\n"); 173 174 /* Read diff string */ 175 lenread = BZ2_bzRead(&dbz2err, dpfbz2, new + newpos, ctrl[0]); 176 if ((lenread < ctrl[0]) || 177 ((dbz2err != BZ_OK) && (dbz2err != BZ_STREAM_END))) 178 errx(1, "Corrupt patch\n"); 179 180 /* Add old data to diff string */ 181 for(i=0;i<ctrl[0];i++) 182 if((oldpos+i>=0) && (oldpos+i<oldsize)) 183 new[newpos+i]+=old[oldpos+i]; 184 185 /* Adjust pointers */ 186 newpos+=ctrl[0]; 187 oldpos+=ctrl[0]; 188 189 /* Sanity-check */ 190 if(newpos+ctrl[1]>newsize) 191 errx(1,"Corrupt patch\n"); 192 193 /* Read extra string */ 194 lenread = BZ2_bzRead(&ebz2err, epfbz2, new + newpos, ctrl[1]); 195 if ((lenread < ctrl[1]) || 196 ((ebz2err != BZ_OK) && (ebz2err != BZ_STREAM_END))) 197 errx(1, "Corrupt patch\n"); 198 199 /* Adjust pointers */ 200 newpos+=ctrl[1]; 201 oldpos+=ctrl[2]; 202 } 203 204 /* Clean up the bzip2 reads */ 205 BZ2_bzReadClose(&cbz2err, cpfbz2); 206 BZ2_bzReadClose(&dbz2err, dpfbz2); 207 BZ2_bzReadClose(&ebz2err, epfbz2); 208 if (fclose(cpf) || fclose(dpf) || fclose(epf)) 209 err(1, "fclose(%s)", argv[3]); 210 211 /* Write the new file */ 212 if(((fd=open(argv[2],O_CREAT|O_TRUNC|O_WRONLY|O_BINARY,0666))<0) || 213 (write(fd,new,newsize)!=newsize) || (close(fd)==-1)) 214 err(1,"%s",argv[2]); 215 216 free(new); 217 free(old); 218 219 return 0; 220} 221