1 /* $OpenBSD: dd.c,v 1.14 2003/06/11 23:42:12 deraadt Exp $ */ 2 /* $NetBSD: dd.c,v 1.6 1996/02/20 19:29:06 jtc Exp $ */ 3 4 /*- 5 * Copyright (c) 1991, 1993, 1994 6 * The Regents of the University of California. All rights reserved. 7 * 8 * This code is derived from software contributed to Berkeley by 9 * Keith Muller of the University of California, San Diego and Lance 10 * Visser of Convex Computer Corporation. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 */ 36 37 #ifndef lint 38 static char copyright[] = 39 "@(#) Copyright (c) 1991, 1993, 1994\n\ 40 The Regents of the University of California. All rights reserved.\n"; 41 #endif /* not lint */ 42 43 #ifndef lint 44 #if 0 45 static char sccsid[] = "@(#)dd.c 8.5 (Berkeley) 4/2/94"; 46 #else 47 static char rcsid[] = "$OpenBSD: dd.c,v 1.14 2003/06/11 23:42:12 deraadt Exp $"; 48 #endif 49 #endif /* not lint */ 50 51 #include <sys/param.h> 52 #include <sys/stat.h> 53 #include <sys/ioctl.h> 54 #include <sys/mtio.h> 55 56 #include <ctype.h> 57 #include <err.h> 58 #include <errno.h> 59 #include <fcntl.h> 60 #include <signal.h> 61 #include <stdio.h> 62 #include <stdlib.h> 63 #include <string.h> 64 #include <unistd.h> 65 66 #include "dd.h" 67 #include "extern.h" 68 69 static void dd_close(void); 70 static void dd_in(void); 71 static void getfdtype(IO *); 72 static void setup(void); 73 74 IO in, out; /* input/output state */ 75 STAT st; /* statistics */ 76 void (*cfunc)(void); /* conversion function */ 77 size_t cpy_cnt; /* # of blocks to copy */ 78 u_int ddflags; /* conversion options */ 79 size_t cbsz; /* conversion block size */ 80 size_t files_cnt = 1; /* # of files to copy */ 81 const u_char *ctab; /* conversion table */ 82 83 int 84 main(int argc, char *argv[]) 85 { 86 jcl(argv); 87 setup(); 88 89 (void)signal(SIGINFO, summaryx); 90 (void)signal(SIGINT, terminate); 91 92 atexit(summary); 93 94 if (cpy_cnt != (size_t)-1) { 95 while (files_cnt--) 96 dd_in(); 97 } 98 99 dd_close(); 100 exit(0); 101 } 102 103 static void 104 setup(void) 105 { 106 u_int cnt; 107 108 if (in.name == NULL) { 109 in.name = "stdin"; 110 in.fd = STDIN_FILENO; 111 } else { 112 in.fd = open(in.name, O_RDONLY, 0); 113 if (in.fd < 0) 114 err(1, "%s", in.name); 115 } 116 117 getfdtype(&in); 118 119 if (files_cnt > 1 && !(in.flags & ISTAPE)) 120 errx(1, "files is not supported for non-tape devices"); 121 122 if (out.name == NULL) { 123 /* No way to check for read access here. */ 124 out.fd = STDOUT_FILENO; 125 out.name = "stdout"; 126 } else { 127 #define OFLAGS \ 128 (O_CREAT | (ddflags & (C_SEEK | C_NOTRUNC) ? 0 : O_TRUNC)) 129 out.fd = open(out.name, O_RDWR | OFLAGS, DEFFILEMODE); 130 /* 131 * May not have read access, so try again with write only. 132 * Without read we may have a problem if output also does 133 * not support seeks. 134 */ 135 if (out.fd < 0) { 136 out.fd = open(out.name, O_WRONLY | OFLAGS, DEFFILEMODE); 137 out.flags |= NOREAD; 138 } 139 if (out.fd < 0) 140 err(1, "%s", out.name); 141 } 142 143 getfdtype(&out); 144 145 /* 146 * Allocate space for the input and output buffers. If not doing 147 * record oriented I/O, only need a single buffer. 148 */ 149 if (!(ddflags & (C_BLOCK|C_UNBLOCK))) { 150 if ((in.db = malloc(out.dbsz + in.dbsz - 1)) == NULL) 151 err(1, "input buffer"); 152 out.db = in.db; 153 } else if ((in.db = 154 malloc((u_int)(MAX(in.dbsz, cbsz) + cbsz))) == NULL || 155 (out.db = malloc((u_int)(out.dbsz + cbsz))) == NULL) 156 err(1, "output buffer"); 157 in.dbp = in.db; 158 out.dbp = out.db; 159 160 /* Position the input/output streams. */ 161 if (in.offset) 162 pos_in(); 163 if (out.offset) 164 pos_out(); 165 166 /* 167 * Truncate the output file; ignore errors because it fails on some 168 * kinds of output files, tapes, for example. 169 */ 170 if ((ddflags & (C_OF | C_SEEK | C_NOTRUNC)) == (C_OF | C_SEEK)) 171 (void)ftruncate(out.fd, out.offset * out.dbsz); 172 173 /* 174 * If converting case at the same time as another conversion, build a 175 * table that does both at once. If just converting case, use the 176 * built-in tables. 177 */ 178 if (ddflags & (C_LCASE|C_UCASE)) { 179 #ifdef NO_CONV 180 /* Should not get here, but just in case... */ 181 errx(1, "case conv and -DNO_CONV"); 182 #else /* NO_CONV */ 183 if (ddflags & C_ASCII || ddflags & C_EBCDIC) { 184 if (ddflags & C_LCASE) { 185 for (cnt = 0; cnt < 0377; ++cnt) 186 casetab[cnt] = tolower(ctab[cnt]); 187 } else { 188 for (cnt = 0; cnt < 0377; ++cnt) 189 casetab[cnt] = toupper(ctab[cnt]); 190 } 191 } else { 192 if (ddflags & C_LCASE) { 193 for (cnt = 0; cnt < 0377; ++cnt) 194 casetab[cnt] = tolower(cnt); 195 } else { 196 for (cnt = 0; cnt < 0377; ++cnt) 197 casetab[cnt] = toupper(cnt); 198 } 199 } 200 201 ctab = casetab; 202 #endif /* NO_CONV */ 203 } 204 205 /* Statistics timestamp. */ 206 (void)gettimeofday(&st.startv, (struct timezone *)NULL); 207 } 208 209 static void 210 getfdtype(IO *io) 211 { 212 struct mtget mt; 213 struct stat sb; 214 215 if (fstat(io->fd, &sb)) 216 err(1, "%s", io->name); 217 if (S_ISCHR(sb.st_mode)) 218 io->flags |= ioctl(io->fd, MTIOCGET, &mt) ? ISCHR : ISTAPE; 219 else if (lseek(io->fd, (off_t)0, SEEK_CUR) == -1 && errno == ESPIPE) 220 io->flags |= ISPIPE; /* XXX fixed in 4.4BSD */ 221 } 222 223 static void 224 dd_in(void) 225 { 226 ssize_t n; 227 228 for (;;) { 229 if (cpy_cnt && (st.in_full + st.in_part) >= cpy_cnt) 230 return; 231 232 /* 233 * Zero the buffer first if sync; if doing block operations 234 * use spaces. 235 */ 236 if (ddflags & C_SYNC) { 237 if (ddflags & (C_BLOCK|C_UNBLOCK)) 238 (void)memset(in.dbp, ' ', in.dbsz); 239 else 240 (void)memset(in.dbp, 0, in.dbsz); 241 } 242 243 n = read(in.fd, in.dbp, in.dbsz); 244 if (n == 0) { 245 in.dbrcnt = 0; 246 return; 247 } 248 249 /* Read error. */ 250 if (n < 0) { 251 /* 252 * If noerror not specified, die. POSIX requires that 253 * the warning message be followed by an I/O display. 254 */ 255 if (!(ddflags & C_NOERROR)) 256 err(1, "%s", in.name); 257 warn("%s", in.name); 258 summary(); 259 260 /* 261 * If it's not a tape drive or a pipe, seek past the 262 * error. If your OS doesn't do the right thing for 263 * raw disks this section should be modified to re-read 264 * in sector size chunks. 265 */ 266 if (!(in.flags & (ISPIPE|ISTAPE)) && 267 lseek(in.fd, (off_t)in.dbsz, SEEK_CUR)) 268 warn("%s", in.name); 269 270 /* If sync not specified, omit block and continue. */ 271 if (!(ddflags & C_SYNC)) 272 continue; 273 274 /* Read errors count as full blocks. */ 275 in.dbcnt += in.dbrcnt = in.dbsz; 276 ++st.in_full; 277 278 /* Handle full input blocks. */ 279 } else if (n == in.dbsz) { 280 in.dbcnt += in.dbrcnt = n; 281 ++st.in_full; 282 283 /* Handle partial input blocks. */ 284 } else { 285 /* If sync, use the entire block. */ 286 if (ddflags & C_SYNC) 287 in.dbcnt += in.dbrcnt = in.dbsz; 288 else 289 in.dbcnt += in.dbrcnt = n; 290 ++st.in_part; 291 } 292 293 /* 294 * POSIX states that if bs is set and no other conversions 295 * than noerror, notrunc or sync are specified, the block 296 * is output without buffering as it is read. 297 */ 298 if (ddflags & C_BS) { 299 out.dbcnt = in.dbcnt; 300 dd_out(1); 301 in.dbcnt = 0; 302 continue; 303 } 304 305 if (ddflags & C_SWAB) { 306 if ((n = in.dbcnt) & 1) { 307 ++st.swab; 308 --n; 309 } 310 swab(in.dbp, in.dbp, n); 311 } 312 313 in.dbp += in.dbrcnt; 314 (*cfunc)(); 315 } 316 } 317 318 /* 319 * Cleanup any remaining I/O and flush output. If necessary, output file 320 * is truncated. 321 */ 322 static void 323 dd_close(void) 324 { 325 if (cfunc == def) 326 def_close(); 327 else if (cfunc == block) 328 block_close(); 329 else if (cfunc == unblock) 330 unblock_close(); 331 if (ddflags & C_OSYNC && out.dbcnt && out.dbcnt < out.dbsz) { 332 if (ddflags & (C_BLOCK|C_UNBLOCK)) 333 memset(out.dbp, ' ', out.dbsz - out.dbcnt); 334 else 335 memset(out.dbp, 0, out.dbsz - out.dbcnt); 336 out.dbcnt = out.dbsz; 337 } 338 if (out.dbcnt) 339 dd_out(1); 340 } 341 342 void 343 dd_out(int force) 344 { 345 static int warned; 346 size_t cnt, n; 347 ssize_t nw; 348 u_char *outp; 349 350 /* 351 * Write one or more blocks out. The common case is writing a full 352 * output block in a single write; increment the full block stats. 353 * Otherwise, we're into partial block writes. If a partial write, 354 * and it's a character device, just warn. If a tape device, quit. 355 * 356 * The partial writes represent two cases. 1: Where the input block 357 * was less than expected so the output block was less than expected. 358 * 2: Where the input block was the right size but we were forced to 359 * write the block in multiple chunks. The original versions of dd(1) 360 * never wrote a block in more than a single write, so the latter case 361 * never happened. 362 * 363 * One special case is if we're forced to do the write -- in that case 364 * we play games with the buffer size, and it's usually a partial write. 365 */ 366 outp = out.db; 367 for (n = force ? out.dbcnt : out.dbsz;; n = out.dbsz) { 368 for (cnt = n;; cnt -= nw) { 369 nw = write(out.fd, outp, cnt); 370 if (nw <= 0) { 371 if (nw == 0) 372 errx(1, "%s: end of device", out.name); 373 if (errno != EINTR) 374 err(1, "%s", out.name); 375 nw = 0; 376 } 377 outp += nw; 378 st.bytes += nw; 379 if (nw == n) { 380 if (n != out.dbsz) 381 ++st.out_part; 382 else 383 ++st.out_full; 384 break; 385 } 386 ++st.out_part; 387 if (nw == cnt) 388 break; 389 if (out.flags & ISCHR && !warned) { 390 warned = 1; 391 warnx("%s: short write on character device", 392 out.name); 393 } 394 if (out.flags & ISTAPE) 395 errx(1, "%s: short write on tape device", out.name); 396 } 397 if ((out.dbcnt -= n) < out.dbsz) 398 break; 399 } 400 401 /* Reassemble the output block. */ 402 if (out.dbcnt) 403 (void)memmove(out.db, out.dbp - out.dbcnt, out.dbcnt); 404 out.dbp = out.db + out.dbcnt; 405 } 406