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