bspatch.c revision 306379
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: releng/11.0/usr.bin/bsdiff/bspatch/bspatch.c 306379 2016-09-27 19:36:12Z emaste $"); 29 30#if defined(__FreeBSD__) 31#include <sys/param.h> 32#if __FreeBSD_version >= 1001511 33#include <sys/capsicum.h> 34#define HAVE_CAPSICUM 35#endif 36#endif 37 38#include <bzlib.h> 39#include <err.h> 40#include <errno.h> 41#include <fcntl.h> 42#include <libgen.h> 43#include <limits.h> 44#include <stdint.h> 45#include <stdio.h> 46#include <stdlib.h> 47#include <string.h> 48#include <unistd.h> 49 50#ifndef O_BINARY 51#define O_BINARY 0 52#endif 53#define HEADER_SIZE 32 54 55static char *newfile; 56static int dirfd = -1; 57 58static void 59exit_cleanup(void) 60{ 61 62 if (dirfd != -1 && newfile != NULL) 63 if (unlinkat(dirfd, newfile, 0)) 64 warn("unlinkat"); 65} 66 67static off_t offtin(u_char *buf) 68{ 69 off_t y; 70 71 y = buf[7] & 0x7F; 72 y = y * 256; y += buf[6]; 73 y = y * 256; y += buf[5]; 74 y = y * 256; y += buf[4]; 75 y = y * 256; y += buf[3]; 76 y = y * 256; y += buf[2]; 77 y = y * 256; y += buf[1]; 78 y = y * 256; y += buf[0]; 79 80 if (buf[7] & 0x80) 81 y = -y; 82 83 return (y); 84} 85 86static void 87usage(void) 88{ 89 90 fprintf(stderr, "usage: bspatch oldfile newfile patchfile\n"); 91 exit(1); 92} 93 94int main(int argc, char *argv[]) 95{ 96 FILE *f, *cpf, *dpf, *epf; 97 BZFILE *cpfbz2, *dpfbz2, *epfbz2; 98 char *directory, *namebuf; 99 int cbz2err, dbz2err, ebz2err; 100 int newfd, oldfd; 101 off_t oldsize, newsize; 102 off_t bzctrllen, bzdatalen; 103 u_char header[HEADER_SIZE], buf[8]; 104 u_char *old, *new; 105 off_t oldpos, newpos; 106 off_t ctrl[3]; 107 off_t i, lenread, offset; 108#ifdef HAVE_CAPSICUM 109 cap_rights_t rights_dir, rights_ro, rights_wr; 110#endif 111 112 if (argc != 4) 113 usage(); 114 115 /* Open patch file */ 116 if ((f = fopen(argv[3], "rb")) == NULL) 117 err(1, "fopen(%s)", argv[3]); 118 /* Open patch file for control block */ 119 if ((cpf = fopen(argv[3], "rb")) == NULL) 120 err(1, "fopen(%s)", argv[3]); 121 /* open patch file for diff block */ 122 if ((dpf = fopen(argv[3], "rb")) == NULL) 123 err(1, "fopen(%s)", argv[3]); 124 /* open patch file for extra block */ 125 if ((epf = fopen(argv[3], "rb")) == NULL) 126 err(1, "fopen(%s)", argv[3]); 127 /* open oldfile */ 128 if ((oldfd = open(argv[1], O_RDONLY | O_BINARY, 0)) < 0) 129 err(1, "open(%s)", argv[1]); 130 /* open directory where we'll write newfile */ 131 if ((namebuf = strdup(argv[2])) == NULL || 132 (directory = dirname(namebuf)) == NULL || 133 (dirfd = open(directory, O_DIRECTORY)) < 0) 134 err(1, "open %s", argv[2]); 135 free(namebuf); 136 if ((newfile = basename(argv[2])) == NULL) 137 err(1, "basename"); 138 /* open newfile */ 139 if ((newfd = openat(dirfd, newfile, 140 O_CREAT | O_TRUNC | O_WRONLY | O_BINARY, 0666)) < 0) 141 err(1, "open(%s)", argv[2]); 142 atexit(exit_cleanup); 143 144#ifdef HAVE_CAPSICUM 145 if (cap_enter() < 0) { 146 /* Failed to sandbox, fatal if CAPABILITY_MODE enabled */ 147 if (errno != ENOSYS) 148 err(1, "failed to enter security sandbox"); 149 } else { 150 /* Capsicum Available */ 151 cap_rights_init(&rights_ro, CAP_READ, CAP_FSTAT, CAP_SEEK); 152 cap_rights_init(&rights_wr, CAP_WRITE); 153 cap_rights_init(&rights_dir, CAP_UNLINKAT); 154 155 if (cap_rights_limit(fileno(f), &rights_ro) < 0 || 156 cap_rights_limit(fileno(cpf), &rights_ro) < 0 || 157 cap_rights_limit(fileno(dpf), &rights_ro) < 0 || 158 cap_rights_limit(fileno(epf), &rights_ro) < 0 || 159 cap_rights_limit(oldfd, &rights_ro) < 0 || 160 cap_rights_limit(newfd, &rights_wr) < 0 || 161 cap_rights_limit(dirfd, &rights_dir) < 0) 162 err(1, "cap_rights_limit() failed, could not restrict" 163 " capabilities"); 164 } 165#endif 166 167 /* 168 File format: 169 0 8 "BSDIFF40" 170 8 8 X 171 16 8 Y 172 24 8 sizeof(newfile) 173 32 X bzip2(control block) 174 32+X Y bzip2(diff block) 175 32+X+Y ??? bzip2(extra block) 176 with control block a set of triples (x,y,z) meaning "add x bytes 177 from oldfile to x bytes from the diff block; copy y bytes from the 178 extra block; seek forwards in oldfile by z bytes". 179 */ 180 181 /* Read header */ 182 if (fread(header, 1, HEADER_SIZE, f) < HEADER_SIZE) { 183 if (feof(f)) 184 errx(1, "Corrupt patch"); 185 err(1, "fread(%s)", argv[3]); 186 } 187 188 /* Check for appropriate magic */ 189 if (memcmp(header, "BSDIFF40", 8) != 0) 190 errx(1, "Corrupt patch"); 191 192 /* Read lengths from header */ 193 bzctrllen = offtin(header + 8); 194 bzdatalen = offtin(header + 16); 195 newsize = offtin(header + 24); 196 if (bzctrllen < 0 || bzctrllen > OFF_MAX - HEADER_SIZE || 197 bzdatalen < 0 || bzctrllen + HEADER_SIZE > OFF_MAX - bzdatalen || 198 newsize < 0 || newsize > SSIZE_MAX) 199 errx(1, "Corrupt patch"); 200 201 /* Close patch file and re-open it via libbzip2 at the right places */ 202 if (fclose(f)) 203 err(1, "fclose(%s)", argv[3]); 204 offset = HEADER_SIZE; 205 if (fseeko(cpf, offset, SEEK_SET)) 206 err(1, "fseeko(%s, %jd)", argv[3], (intmax_t)offset); 207 if ((cpfbz2 = BZ2_bzReadOpen(&cbz2err, cpf, 0, 0, NULL, 0)) == NULL) 208 errx(1, "BZ2_bzReadOpen, bz2err = %d", cbz2err); 209 offset += bzctrllen; 210 if (fseeko(dpf, offset, SEEK_SET)) 211 err(1, "fseeko(%s, %jd)", argv[3], (intmax_t)offset); 212 if ((dpfbz2 = BZ2_bzReadOpen(&dbz2err, dpf, 0, 0, NULL, 0)) == NULL) 213 errx(1, "BZ2_bzReadOpen, bz2err = %d", dbz2err); 214 offset += bzdatalen; 215 if (fseeko(epf, offset, SEEK_SET)) 216 err(1, "fseeko(%s, %jd)", argv[3], (intmax_t)offset); 217 if ((epfbz2 = BZ2_bzReadOpen(&ebz2err, epf, 0, 0, NULL, 0)) == NULL) 218 errx(1, "BZ2_bzReadOpen, bz2err = %d", ebz2err); 219 220 if ((oldsize = lseek(oldfd, 0, SEEK_END)) == -1 || 221 oldsize > SSIZE_MAX || 222 (old = malloc(oldsize)) == NULL || 223 lseek(oldfd, 0, SEEK_SET) != 0 || 224 read(oldfd, old, oldsize) != oldsize || 225 close(oldfd) == -1) 226 err(1, "%s", argv[1]); 227 if ((new = malloc(newsize)) == NULL) 228 err(1, NULL); 229 230 oldpos = 0; 231 newpos = 0; 232 while (newpos < newsize) { 233 /* Read control data */ 234 for (i = 0; i <= 2; i++) { 235 lenread = BZ2_bzRead(&cbz2err, cpfbz2, buf, 8); 236 if ((lenread < 8) || ((cbz2err != BZ_OK) && 237 (cbz2err != BZ_STREAM_END))) 238 errx(1, "Corrupt patch"); 239 ctrl[i] = offtin(buf); 240 } 241 242 /* Sanity-check */ 243 if (ctrl[0] < 0 || ctrl[0] > INT_MAX || 244 ctrl[1] < 0 || ctrl[1] > INT_MAX) 245 errx(1, "Corrupt patch"); 246 247 /* Sanity-check */ 248 if (newpos + ctrl[0] > newsize) 249 errx(1, "Corrupt patch"); 250 251 /* Read diff string */ 252 lenread = BZ2_bzRead(&dbz2err, dpfbz2, new + newpos, ctrl[0]); 253 if ((lenread < ctrl[0]) || 254 ((dbz2err != BZ_OK) && (dbz2err != BZ_STREAM_END))) 255 errx(1, "Corrupt patch"); 256 257 /* Add old data to diff string */ 258 for (i = 0; i < ctrl[0]; i++) 259 if ((oldpos + i >= 0) && (oldpos + i < oldsize)) 260 new[newpos + i] += old[oldpos + i]; 261 262 /* Adjust pointers */ 263 newpos += ctrl[0]; 264 oldpos += ctrl[0]; 265 266 /* Sanity-check */ 267 if (newpos + ctrl[1] > newsize) 268 errx(1, "Corrupt patch"); 269 270 /* Read extra string */ 271 lenread = BZ2_bzRead(&ebz2err, epfbz2, new + newpos, ctrl[1]); 272 if ((lenread < ctrl[1]) || 273 ((ebz2err != BZ_OK) && (ebz2err != BZ_STREAM_END))) 274 errx(1, "Corrupt patch"); 275 276 /* Adjust pointers */ 277 newpos+=ctrl[1]; 278 oldpos+=ctrl[2]; 279 } 280 281 /* Clean up the bzip2 reads */ 282 BZ2_bzReadClose(&cbz2err, cpfbz2); 283 BZ2_bzReadClose(&dbz2err, dpfbz2); 284 BZ2_bzReadClose(&ebz2err, epfbz2); 285 if (fclose(cpf) || fclose(dpf) || fclose(epf)) 286 err(1, "fclose(%s)", argv[3]); 287 288 /* Write the new file */ 289 if (write(newfd, new, newsize) != newsize || close(newfd) == -1) 290 err(1, "%s", argv[2]); 291 /* Disable atexit cleanup */ 292 newfile = NULL; 293 294 free(new); 295 free(old); 296 297 return (0); 298} 299