1 /* $OpenBSD: dd.c,v 1.9 2001/08/07 14:39:27 hugh 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. All advertising materials mentioning features or use of this software 21 * must display the following acknowledgement: 22 * This product includes software developed by the University of 23 * California, Berkeley and its contributors. 24 * 4. Neither the name of the University nor the names of its contributors 25 * may be used to endorse or promote products derived from this software 26 * without specific prior written permission. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 31 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 38 * SUCH DAMAGE. 39 */ 40 41 #ifndef lint 42 static char copyright[] = 43 "@(#) Copyright (c) 1991, 1993, 1994\n\ 44 The Regents of the University of California. All rights reserved.\n"; 45 #endif /* not lint */ 46 47 #ifndef lint 48 #if 0 49 static char sccsid[] = "@(#)dd.c 8.5 (Berkeley) 4/2/94"; 50 #else 51 static char rcsid[] = "$OpenBSD: dd.c,v 1.9 2001/08/07 14:39:27 hugh Exp $"; 52 #endif 53 #endif /* not lint */ 54 55 #include <sys/param.h> 56 #include <sys/stat.h> 57 #include <sys/ioctl.h> 58 #include <sys/mtio.h> 59 60 #include <ctype.h> 61 #include <err.h> 62 #include <errno.h> 63 #include <fcntl.h> 64 #include <signal.h> 65 #include <stdio.h> 66 #include <stdlib.h> 67 #include <string.h> 68 #include <unistd.h> 69 70 #include "dd.h" 71 #include "extern.h" 72 73 static void dd_close __P((void)); 74 static void dd_in __P((void)); 75 static void getfdtype __P((IO *)); 76 static void setup __P((void)); 77 78 IO in, out; /* input/output state */ 79 STAT st; /* statistics */ 80 void (*cfunc) __P((void)); /* conversion function */ 81 size_t cpy_cnt; /* # of blocks to copy */ 82 u_int ddflags; /* conversion options */ 83 size_t cbsz; /* conversion block size */ 84 size_t files_cnt = 1; /* # of files to copy */ 85 const u_char *ctab; /* conversion table */ 86 87 int 88 main(argc, argv) 89 int argc; 90 char *argv[]; 91 { 92 jcl(argv); 93 setup(); 94 95 (void)signal(SIGINFO, summaryx); 96 (void)signal(SIGINT, terminate); 97 98 atexit(summary); 99 100 while (files_cnt--) 101 dd_in(); 102 103 dd_close(); 104 exit(0); 105 } 106 107 static void 108 setup() 109 { 110 u_int cnt; 111 112 if (in.name == NULL) { 113 in.name = "stdin"; 114 in.fd = STDIN_FILENO; 115 } else { 116 in.fd = open(in.name, O_RDONLY, 0); 117 if (in.fd < 0) 118 err(1, "%s", in.name); 119 } 120 121 getfdtype(&in); 122 123 if (files_cnt > 1 && !(in.flags & ISTAPE)) 124 errx(1, "files is not supported for non-tape devices"); 125 126 if (out.name == NULL) { 127 /* No way to check for read access here. */ 128 out.fd = STDOUT_FILENO; 129 out.name = "stdout"; 130 } else { 131 #define OFLAGS \ 132 (O_CREAT | (ddflags & (C_SEEK | C_NOTRUNC) ? 0 : O_TRUNC)) 133 out.fd = open(out.name, O_RDWR | OFLAGS, DEFFILEMODE); 134 /* 135 * May not have read access, so try again with write only. 136 * Without read we may have a problem if output also does 137 * not support seeks. 138 */ 139 if (out.fd < 0) { 140 out.fd = open(out.name, O_WRONLY | OFLAGS, DEFFILEMODE); 141 out.flags |= NOREAD; 142 } 143 if (out.fd < 0) 144 err(1, "%s", out.name); 145 } 146 147 getfdtype(&out); 148 149 /* 150 * Allocate space for the input and output buffers. If not doing 151 * record oriented I/O, only need a single buffer. 152 */ 153 if (!(ddflags & (C_BLOCK|C_UNBLOCK))) { 154 if ((in.db = malloc(out.dbsz + in.dbsz - 1)) == NULL) 155 err(1, "input buffer"); 156 out.db = in.db; 157 } else if ((in.db = 158 malloc((u_int)(MAX(in.dbsz, cbsz) + cbsz))) == NULL || 159 (out.db = malloc((u_int)(out.dbsz + cbsz))) == NULL) 160 err(1, "output buffer"); 161 in.dbp = in.db; 162 out.dbp = out.db; 163 164 /* Position the input/output streams. */ 165 if (in.offset) 166 pos_in(); 167 if (out.offset) 168 pos_out(); 169 170 /* 171 * Truncate the output file; ignore errors because it fails on some 172 * kinds of output files, tapes, for example. 173 */ 174 if ((ddflags & (C_OF | C_SEEK | C_NOTRUNC)) == (C_OF | C_SEEK)) 175 (void)ftruncate(out.fd, out.offset * out.dbsz); 176 177 /* 178 * If converting case at the same time as another conversion, build a 179 * table that does both at once. If just converting case, use the 180 * built-in tables. 181 */ 182 if (ddflags & (C_LCASE|C_UCASE)) { 183 #ifdef NO_CONV 184 /* Should not get here, but just in case... */ 185 errx(1, "case conv and -DNO_CONV"); 186 #else /* NO_CONV */ 187 if (ddflags & C_ASCII || ddflags & C_EBCDIC) { 188 if (ddflags & C_LCASE) { 189 for (cnt = 0; cnt < 0377; ++cnt) 190 casetab[cnt] = tolower(ctab[cnt]); 191 } else { 192 for (cnt = 0; cnt < 0377; ++cnt) 193 casetab[cnt] = toupper(ctab[cnt]); 194 } 195 } else { 196 if (ddflags & C_LCASE) { 197 for (cnt = 0; cnt < 0377; ++cnt) 198 casetab[cnt] = tolower(cnt); 199 } else { 200 for (cnt = 0; cnt < 0377; ++cnt) 201 casetab[cnt] = toupper(cnt); 202 } 203 } 204 205 ctab = casetab; 206 #endif /* NO_CONV */ 207 } 208 209 /* Statistics timestamp. */ 210 (void)gettimeofday(&st.startv, (struct timezone *)NULL); 211 } 212 213 static void 214 getfdtype(io) 215 IO *io; 216 { 217 struct mtget mt; 218 struct stat sb; 219 220 if (fstat(io->fd, &sb)) 221 err(1, "%s", io->name); 222 if (S_ISCHR(sb.st_mode)) 223 io->flags |= ioctl(io->fd, MTIOCGET, &mt) ? ISCHR : ISTAPE; 224 else if (lseek(io->fd, (off_t)0, SEEK_CUR) == -1 && errno == ESPIPE) 225 io->flags |= ISPIPE; /* XXX fixed in 4.4BSD */ 226 } 227 228 static void 229 dd_in() 230 { 231 ssize_t n; 232 233 for (;;) { 234 if (cpy_cnt && (st.in_full + st.in_part) >= cpy_cnt) 235 return; 236 237 /* 238 * Zero the buffer first if sync; if doing block operations 239 * use spaces. 240 */ 241 if (ddflags & C_SYNC) { 242 if (ddflags & (C_BLOCK|C_UNBLOCK)) 243 (void)memset(in.dbp, ' ', in.dbsz); 244 else 245 (void)memset(in.dbp, 0, in.dbsz); 246 } 247 248 n = read(in.fd, in.dbp, in.dbsz); 249 if (n == 0) { 250 in.dbrcnt = 0; 251 return; 252 } 253 254 /* Read error. */ 255 if (n < 0) { 256 /* 257 * If noerror not specified, die. POSIX requires that 258 * the warning message be followed by an I/O display. 259 */ 260 if (!(ddflags & C_NOERROR)) 261 err(1, "%s", in.name); 262 warn("%s", in.name); 263 summary(); 264 265 /* 266 * If it's not a tape drive or a pipe, seek past the 267 * error. If your OS doesn't do the right thing for 268 * raw disks this section should be modified to re-read 269 * in sector size chunks. 270 */ 271 if (!(in.flags & (ISPIPE|ISTAPE)) && 272 lseek(in.fd, (off_t)in.dbsz, SEEK_CUR)) 273 warn("%s", in.name); 274 275 /* If sync not specified, omit block and continue. */ 276 if (!(ddflags & C_SYNC)) 277 continue; 278 279 /* Read errors count as full blocks. */ 280 in.dbcnt += in.dbrcnt = in.dbsz; 281 ++st.in_full; 282 283 /* Handle full input blocks. */ 284 } else if (n == in.dbsz) { 285 in.dbcnt += in.dbrcnt = n; 286 ++st.in_full; 287 288 /* Handle partial input blocks. */ 289 } else { 290 /* If sync, use the entire block. */ 291 if (ddflags & C_SYNC) 292 in.dbcnt += in.dbrcnt = in.dbsz; 293 else 294 in.dbcnt += in.dbrcnt = n; 295 ++st.in_part; 296 } 297 298 /* 299 * POSIX states that if bs is set and no other conversions 300 * than noerror, notrunc or sync are specified, the block 301 * is output without buffering as it is read. 302 */ 303 if (ddflags & C_BS) { 304 out.dbcnt = in.dbcnt; 305 dd_out(1); 306 in.dbcnt = 0; 307 continue; 308 } 309 310 if (ddflags & C_SWAB) { 311 if ((n = in.dbcnt) & 1) { 312 ++st.swab; 313 --n; 314 } 315 swab(in.dbp, in.dbp, n); 316 } 317 318 in.dbp += in.dbrcnt; 319 (*cfunc)(); 320 } 321 } 322 323 /* 324 * Cleanup any remaining I/O and flush output. If necessary, output file 325 * is truncated. 326 */ 327 static void 328 dd_close() 329 { 330 if (cfunc == def) 331 def_close(); 332 else if (cfunc == block) 333 block_close(); 334 else if (cfunc == unblock) 335 unblock_close(); 336 if (ddflags & C_OSYNC && out.dbcnt && out.dbcnt < out.dbsz) { 337 if (ddflags & (C_BLOCK|C_UNBLOCK)) 338 memset(out.dbp, ' ', out.dbsz - out.dbcnt); 339 else 340 memset(out.dbp, 0, out.dbsz - out.dbcnt); 341 out.dbcnt = out.dbsz; 342 } 343 if (out.dbcnt) 344 dd_out(1); 345 } 346 347 void 348 dd_out(force) 349 int force; 350 { 351 static int warned; 352 size_t cnt, n; 353 ssize_t nw; 354 u_char *outp; 355 356 /* 357 * Write one or more blocks out. The common case is writing a full 358 * output block in a single write; increment the full block stats. 359 * Otherwise, we're into partial block writes. If a partial write, 360 * and it's a character device, just warn. If a tape device, quit. 361 * 362 * The partial writes represent two cases. 1: Where the input block 363 * was less than expected so the output block was less than expected. 364 * 2: Where the input block was the right size but we were forced to 365 * write the block in multiple chunks. The original versions of dd(1) 366 * never wrote a block in more than a single write, so the latter case 367 * never happened. 368 * 369 * One special case is if we're forced to do the write -- in that case 370 * we play games with the buffer size, and it's usually a partial write. 371 */ 372 outp = out.db; 373 for (n = force ? out.dbcnt : out.dbsz;; n = out.dbsz) { 374 for (cnt = n;; cnt -= nw) { 375 nw = write(out.fd, outp, cnt); 376 if (nw <= 0) { 377 if (nw == 0) 378 errx(1, "%s: end of device", out.name); 379 if (errno != EINTR) 380 err(1, "%s", out.name); 381 nw = 0; 382 } 383 outp += nw; 384 st.bytes += nw; 385 if (nw == n) { 386 if (n != out.dbsz) 387 ++st.out_part; 388 else 389 ++st.out_full; 390 break; 391 } 392 ++st.out_part; 393 if (nw == cnt) 394 break; 395 if (out.flags & ISCHR && !warned) { 396 warned = 1; 397 warnx("%s: short write on character device", 398 out.name); 399 } 400 if (out.flags & ISTAPE) 401 errx(1, "%s: short write on tape device", out.name); 402 } 403 if ((out.dbcnt -= n) < out.dbsz) 404 break; 405 } 406 407 /* Reassemble the output block. */ 408 if (out.dbcnt) 409 (void)memmove(out.db, out.dbp - out.dbcnt, out.dbcnt); 410 out.dbp = out.db + out.dbcnt; 411 } 412