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 #if 0 28 __FBSDID("$FreeBSD: src/usr.bin/bsdiff/bspatch/bspatch.c,v 1.1 2005/08/06 01:59:06 cperciva Exp $"); 29 #endif 30 31 #include "bspatch.h" 32 33 #include <bzlib.h> 34 #include <err.h> 35 #include <fcntl.h> 36 #include <inttypes.h> 37 #include <stdlib.h> 38 #include <string.h> 39 #include <unistd.h> 40 #include <sys/types.h> 41 42 #include <algorithm> 43 #include <memory> 44 #include <limits> 45 46 #include "extents.h" 47 #include "extents_file.h" 48 #include "file.h" 49 #include "file_interface.h" 50 51 namespace { 52 53 int64_t ParseInt64(u_char* buf) { 54 int64_t y; 55 56 y = buf[7] & 0x7F; 57 y = y * 256; 58 y += buf[6]; 59 y = y * 256; 60 y += buf[5]; 61 y = y * 256; 62 y += buf[4]; 63 y = y * 256; 64 y += buf[3]; 65 y = y * 256; 66 y += buf[2]; 67 y = y * 256; 68 y += buf[1]; 69 y = y * 256; 70 y += buf[0]; 71 72 if (buf[7] & 0x80) 73 y = -y; 74 75 return y; 76 } 77 78 } // namespace 79 80 namespace bsdiff { 81 82 int bspatch( 83 const char* old_filename, const char* new_filename, 84 const char* patch_filename, 85 const char* old_extents, const char* new_extents) { 86 FILE* f, *cpf, *dpf, *epf; 87 BZFILE* cpfbz2, *dpfbz2, *epfbz2; 88 int cbz2err, dbz2err, ebz2err; 89 ssize_t bzctrllen, bzdatalen; 90 u_char header[32], buf[8]; 91 u_char* new_buf; 92 off_t ctrl[3]; 93 off_t lenread; 94 95 int using_extents = (old_extents != NULL || new_extents != NULL); 96 97 // Open patch file. 98 if ((f = fopen(patch_filename, "r")) == NULL) 99 err(1, "fopen(%s)", patch_filename); 100 101 // File format: 102 // 0 8 "BSDIFF40" 103 // 8 8 X 104 // 16 8 Y 105 // 24 8 sizeof(new_filename) 106 // 32 X bzip2(control block) 107 // 32+X Y bzip2(diff block) 108 // 32+X+Y ??? bzip2(extra block) 109 // with control block a set of triples (x,y,z) meaning "add x bytes 110 // from oldfile to x bytes from the diff block; copy y bytes from the 111 // extra block; seek forwards in oldfile by z bytes". 112 113 // Read header. 114 if (fread(header, 1, 32, f) < 32) { 115 if (feof(f)) 116 errx(1, "Corrupt patch\n"); 117 err(1, "fread(%s)", patch_filename); 118 } 119 120 // Check for appropriate magic. 121 if (memcmp(header, "BSDIFF40", 8) != 0) 122 errx(1, "Corrupt patch\n"); 123 124 // Read lengths from header. 125 uint64_t oldsize, newsize; 126 bzctrllen = ParseInt64(header + 8); 127 bzdatalen = ParseInt64(header + 16); 128 int64_t signed_newsize = ParseInt64(header + 24); 129 newsize = signed_newsize; 130 if ((bzctrllen < 0) || (bzdatalen < 0) || (signed_newsize < 0)) 131 errx(1, "Corrupt patch\n"); 132 133 // Close patch file and re-open it via libbzip2 at the right places. 134 if (fclose(f)) 135 err(1, "fclose(%s)", patch_filename); 136 if ((cpf = fopen(patch_filename, "r")) == NULL) 137 err(1, "fopen(%s)", patch_filename); 138 if (fseek(cpf, 32, SEEK_SET)) 139 err(1, "fseeko(%s, %lld)", patch_filename, (long long)32); 140 if ((cpfbz2 = BZ2_bzReadOpen(&cbz2err, cpf, 0, 0, NULL, 0)) == NULL) 141 errx(1, "BZ2_bzReadOpen, bz2err = %d", cbz2err); 142 if ((dpf = fopen(patch_filename, "r")) == NULL) 143 err(1, "fopen(%s)", patch_filename); 144 if (fseek(dpf, 32 + bzctrllen, SEEK_SET)) 145 err(1, "fseeko(%s, %lld)", patch_filename, (long long)(32 + bzctrllen)); 146 if ((dpfbz2 = BZ2_bzReadOpen(&dbz2err, dpf, 0, 0, NULL, 0)) == NULL) 147 errx(1, "BZ2_bzReadOpen, bz2err = %d", dbz2err); 148 if ((epf = fopen(patch_filename, "r")) == NULL) 149 err(1, "fopen(%s)", patch_filename); 150 if (fseek(epf, 32 + bzctrllen + bzdatalen, SEEK_SET)) 151 err(1, "fseeko(%s, %lld)", patch_filename, 152 (long long)(32 + bzctrllen + bzdatalen)); 153 if ((epfbz2 = BZ2_bzReadOpen(&ebz2err, epf, 0, 0, NULL, 0)) == NULL) 154 errx(1, "BZ2_bzReadOpen, bz2err = %d", ebz2err); 155 156 // Open input file for reading. 157 std::unique_ptr<FileInterface> old_file = File::FOpen(old_filename, O_RDONLY); 158 if (!old_file) 159 err(1, "Error opening the old filename"); 160 161 if (using_extents) { 162 std::vector<ex_t> parsed_old_extents; 163 if (!ParseExtentStr(old_extents, &parsed_old_extents)) 164 errx(1, "Error parsing the old extents"); 165 old_file.reset(new ExtentsFile(std::move(old_file), parsed_old_extents)); 166 } 167 168 if (!old_file->GetSize(&oldsize)) 169 err(1, "cannot obtain the size of %s", old_filename); 170 uint64_t old_file_pos = 0; 171 172 if ((new_buf = static_cast<u_char*>(malloc(newsize + 1))) == NULL) 173 err(1, NULL); 174 175 // The oldpos can be negative, but the new pos is only incremented linearly. 176 int64_t oldpos = 0; 177 uint64_t newpos = 0; 178 std::vector<u_char> old_buf(1024 * 1024); 179 while (newpos < newsize) { 180 int64_t i, j; 181 // Read control data. 182 for (i = 0; i <= 2; i++) { 183 lenread = BZ2_bzRead(&cbz2err, cpfbz2, buf, 8); 184 if ((lenread < 8) || ((cbz2err != BZ_OK) && (cbz2err != BZ_STREAM_END))) 185 errx(1, "Corrupt patch\n"); 186 ctrl[i] = ParseInt64(buf); 187 }; 188 189 // Sanity-check. 190 if (ctrl[0] < 0 || ctrl[1] < 0) 191 errx(1, "Corrupt patch\n"); 192 193 // Sanity-check. 194 if (newpos + ctrl[0] > newsize) 195 errx(1, "Corrupt patch\n"); 196 197 // Read diff string. 198 lenread = BZ2_bzRead(&dbz2err, dpfbz2, new_buf + newpos, ctrl[0]); 199 if ((lenread < ctrl[0]) || 200 ((dbz2err != BZ_OK) && (dbz2err != BZ_STREAM_END))) 201 errx(1, "Corrupt patch\n"); 202 203 // Add old data to diff string. It is enough to fseek once, at 204 // the beginning of the sequence, to avoid unnecessary overhead. 205 j = newpos; 206 if ((i = oldpos) < 0) { 207 j -= i; 208 i = 0; 209 } 210 // We just checked that |i| is not negative. 211 if (static_cast<uint64_t>(i) != old_file_pos && !old_file->Seek(i)) 212 err(1, "error seeking input file to offset %" PRId64, i); 213 if ((old_file_pos = oldpos + ctrl[0]) > oldsize) 214 old_file_pos = oldsize; 215 216 uint64_t chunk_size = old_file_pos - i; 217 while (chunk_size > 0) { 218 size_t read_bytes; 219 size_t bytes_to_read = 220 std::min(chunk_size, static_cast<uint64_t>(old_buf.size())); 221 if (!old_file->Read(old_buf.data(), bytes_to_read, &read_bytes)) 222 err(1, "error reading from input file"); 223 if (!read_bytes) 224 errx(1, "EOF reached while reading from input file"); 225 // new_buf already has data from diff block, adds old data to it. 226 for (size_t k = 0; k < read_bytes; k++) 227 new_buf[j++] += old_buf[k]; 228 chunk_size -= read_bytes; 229 } 230 231 // Adjust pointers. 232 newpos += ctrl[0]; 233 oldpos += ctrl[0]; 234 235 // Sanity-check. 236 if (newpos + ctrl[1] > newsize) 237 errx(1, "Corrupt patch\n"); 238 239 // Read extra string. 240 lenread = BZ2_bzRead(&ebz2err, epfbz2, new_buf + newpos, ctrl[1]); 241 if ((lenread < ctrl[1]) || 242 ((ebz2err != BZ_OK) && (ebz2err != BZ_STREAM_END))) 243 errx(1, "Corrupt patch\n"); 244 245 // Adjust pointers. 246 newpos += ctrl[1]; 247 oldpos += ctrl[2]; 248 }; 249 250 // Close input file. 251 old_file->Close(); 252 253 // Clean up the bzip2 reads. 254 BZ2_bzReadClose(&cbz2err, cpfbz2); 255 BZ2_bzReadClose(&dbz2err, dpfbz2); 256 BZ2_bzReadClose(&ebz2err, epfbz2); 257 if (fclose(cpf) || fclose(dpf) || fclose(epf)) 258 err(1, "fclose(%s)", patch_filename); 259 260 // Write the new file. 261 std::unique_ptr<FileInterface> new_file = 262 File::FOpen(new_filename, O_CREAT | O_WRONLY); 263 if (!new_file) 264 err(1, "Error opening the new filename %s", new_filename); 265 266 if (using_extents) { 267 std::vector<ex_t> parsed_new_extents; 268 if (!ParseExtentStr(new_extents, &parsed_new_extents)) 269 errx(1, "Error parsing the new extents"); 270 new_file.reset(new ExtentsFile(std::move(new_file), parsed_new_extents)); 271 } 272 273 u_char* temp_new_buf = new_buf; // new_buf needed for free() 274 while (newsize > 0) { 275 size_t bytes_written; 276 if (!new_file->Write(temp_new_buf, newsize, &bytes_written)) 277 err(1, "Error writing new file %s", new_filename); 278 newsize -= bytes_written; 279 temp_new_buf += bytes_written; 280 } 281 282 if (!new_file->Close()) 283 err(1, "Error closing new file %s", new_filename); 284 285 free(new_buf); 286 287 return 0; 288 } 289 290 } // namespace bsdiff 291
