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 <err.h> 32 #include <fcntl.h> 33 #include <stdio.h> 34 #include <stdlib.h> 35 #include <string.h> 36 #include <unistd.h> 37 38 #ifndef O_BINARY 39 #define O_BINARY 0 40 #endif 41 42 static 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) 56 y = -y; 57 58 return (y); 59 } 60 61 static void 62 usage(void) 63 { 64 65 fprintf(stderr, "usage: bspatch oldfile newfile patchfile\n"); 66 exit(1); 67 } 68 69 int main(int argc, char *argv[]) 70 { 71 FILE *f, *cpf, *dpf, *epf; 72 BZFILE *cpfbz2, *dpfbz2, *epfbz2; 73 int cbz2err, dbz2err, ebz2err; 74 int newfd, oldfd; 75 ssize_t oldsize, newsize; 76 ssize_t bzctrllen, bzdatalen; 77 u_char header[32], buf[8]; 78 u_char *old, *new; 79 off_t oldpos, newpos; 80 off_t ctrl[3]; 81 off_t lenread; 82 off_t i; 83 84 if (argc != 4) 85 usage(); 86 87 /* Open patch file */ 88 if ((f = fopen(argv[3], "rb")) == NULL) 89 err(1, "fopen(%s)", argv[3]); 90 91 /* 92 File format: 93 0 8 "BSDIFF40" 94 8 8 X 95 16 8 Y 96 24 8 sizeof(newfile) 97 32 X bzip2(control block) 98 32+X Y bzip2(diff block) 99 32+X+Y ??? bzip2(extra block) 100 with control block a set of triples (x,y,z) meaning "add x bytes 101 from oldfile to x bytes from the diff block; copy y bytes from the 102 extra block; seek forwards in oldfile by z bytes". 103 */ 104 105 /* Read header */ 106 if (fread(header, 1, 32, f) < 32) { 107 if (feof(f)) 108 errx(1, "Corrupt patch\n"); 109 err(1, "fread(%s)", argv[3]); 110 } 111 112 /* Check for appropriate magic */ 113 if (memcmp(header, "BSDIFF40", 8) != 0) 114 errx(1, "Corrupt patch\n"); 115 116 /* Read lengths from header */ 117 bzctrllen = offtin(header + 8); 118 bzdatalen = offtin(header + 16); 119 newsize = offtin(header + 24); 120 if ((bzctrllen < 0) || (bzdatalen < 0) || (newsize < 0)) 121 errx(1, "Corrupt patch\n"); 122 123 /* Close patch file and re-open it via libbzip2 at the right places */ 124 if (fclose(f)) 125 err(1, "fclose(%s)", argv[3]); 126 if ((cpf = fopen(argv[3], "rb")) == NULL) 127 err(1, "fopen(%s)", argv[3]); 128 if (fseeko(cpf, 32, SEEK_SET)) 129 err(1, "fseeko(%s, %lld)", argv[3], 130 (long long)32); 131 if ((cpfbz2 = BZ2_bzReadOpen(&cbz2err, cpf, 0, 0, NULL, 0)) == NULL) 132 errx(1, "BZ2_bzReadOpen, bz2err = %d", cbz2err); 133 if ((dpf = fopen(argv[3], "rb")) == NULL) 134 err(1, "fopen(%s)", argv[3]); 135 if (fseeko(dpf, 32 + bzctrllen, SEEK_SET)) 136 err(1, "fseeko(%s, %lld)", argv[3], 137 (long long)(32 + bzctrllen)); 138 if ((dpfbz2 = BZ2_bzReadOpen(&dbz2err, dpf, 0, 0, NULL, 0)) == NULL) 139 errx(1, "BZ2_bzReadOpen, bz2err = %d", dbz2err); 140 if ((epf = fopen(argv[3], "rb")) == NULL) 141 err(1, "fopen(%s)", argv[3]); 142 if (fseeko(epf, 32 + bzctrllen + bzdatalen, SEEK_SET)) 143 err(1, "fseeko(%s, %lld)", argv[3], 144 (long long)(32 + bzctrllen + bzdatalen)); 145 if ((epfbz2 = BZ2_bzReadOpen(&ebz2err, epf, 0, 0, NULL, 0)) == NULL) 146 errx(1, "BZ2_bzReadOpen, bz2err = %d", ebz2err); 147 148 oldfd = open(argv[1], O_RDONLY | O_BINARY, 0); 149 if (oldfd < 0) 150 err(1, "%s", argv[1]); 151 if ((oldsize = lseek(oldfd, 0, SEEK_END)) == -1 || 152 (old = malloc(oldsize+1)) == NULL || 153 lseek(oldfd, 0, SEEK_SET) != 0 || 154 read(oldfd, old, oldsize) != oldsize || 155 close(oldfd) == -1) 156 err(1, "%s", argv[1]); 157 if ((new = malloc(newsize + 1)) == NULL) 158 err(1, NULL); 159 160 oldpos = 0; 161 newpos = 0; 162 while (newpos < newsize) { 163 /* Read control data */ 164 for (i = 0; i <= 2; i++) { 165 lenread = BZ2_bzRead(&cbz2err, cpfbz2, buf, 8); 166 if ((lenread < 8) || ((cbz2err != BZ_OK) && 167 (cbz2err != BZ_STREAM_END))) 168 errx(1, "Corrupt patch\n"); 169 ctrl[i] = offtin(buf); 170 } 171 172 /* Sanity-check */ 173 if ((ctrl[0] < 0) || (ctrl[1] < 0)) 174 errx(1, "Corrupt patch\n"); 175 176 /* Sanity-check */ 177 if (newpos + ctrl[0] > newsize) 178 errx(1, "Corrupt patch\n"); 179 180 /* Read diff string */ 181 lenread = BZ2_bzRead(&dbz2err, dpfbz2, new + newpos, ctrl[0]); 182 if ((lenread < ctrl[0]) || 183 ((dbz2err != BZ_OK) && (dbz2err != BZ_STREAM_END))) 184 errx(1, "Corrupt patch\n"); 185 186 /* Add old data to diff string */ 187 for (i = 0; i < ctrl[0]; i++) 188 if ((oldpos + i >= 0) && (oldpos + i < oldsize)) 189 new[newpos + i] += old[oldpos + i]; 190 191 /* Adjust pointers */ 192 newpos += ctrl[0]; 193 oldpos += ctrl[0]; 194 195 /* Sanity-check */ 196 if (newpos + ctrl[1] > newsize) 197 errx(1, "Corrupt patch\n"); 198 199 /* Read extra string */ 200 lenread = BZ2_bzRead(&ebz2err, epfbz2, new + newpos, ctrl[1]); 201 if ((lenread < ctrl[1]) || 202 ((ebz2err != BZ_OK) && (ebz2err != BZ_STREAM_END))) 203 errx(1, "Corrupt patch\n"); 204 205 /* Adjust pointers */ 206 newpos+=ctrl[1]; 207 oldpos+=ctrl[2]; 208 } 209 210 /* Clean up the bzip2 reads */ 211 BZ2_bzReadClose(&cbz2err, cpfbz2); 212 BZ2_bzReadClose(&dbz2err, dpfbz2); 213 BZ2_bzReadClose(&ebz2err, epfbz2); 214 if (fclose(cpf) || fclose(dpf) || fclose(epf)) 215 err(1, "fclose(%s)", argv[3]); 216 217 /* Write the new file */ 218 newfd = open(argv[2], O_CREAT | O_TRUNC | O_WRONLY | O_BINARY, 0666); 219 if (newfd < 0) 220 err(1, "%s", argv[2]); 221 if (write(newfd, new, newsize) != newsize || close(newfd) == -1) 222 err(1, "%s", argv[2]); 223 224 free(new); 225 free(old); 226 227 return (0); 228 } 229