1 /* $OpenBSD: dd.c,v 1.16 2009/10/27 23:59:21 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 #include <sys/param.h> 38 #include <sys/stat.h> 39 #include <sys/ioctl.h> 40 #include <sys/mtio.h> 41 42 #include <ctype.h> 43 #include <err.h> 44 #include <errno.h> 45 #include <fcntl.h> 46 #include <signal.h> 47 #include <stdio.h> 48 #include <stdlib.h> 49 #include <string.h> 50 #include <unistd.h> 51 52 #include "dd.h" 53 #include "extern.h" 54 55 static void dd_close(void); 56 static void dd_in(void); 57 static void getfdtype(IO *); 58 static void setup(void); 59 60 IO in, out; /* input/output state */ 61 STAT st; /* statistics */ 62 void (*cfunc)(void); /* conversion function */ 63 size_t cpy_cnt; /* # of blocks to copy */ 64 u_int ddflags; /* conversion options */ 65 size_t cbsz; /* conversion block size */ 66 size_t files_cnt = 1; /* # of files to copy */ 67 const u_char *ctab; /* conversion table */ 68 69 int 70 main(int argc, char *argv[]) 71 { 72 jcl(argv); 73 setup(); 74 75 (void)signal(SIGINFO, summaryx); 76 (void)signal(SIGINT, terminate); 77 78 atexit(summary); 79 80 if (cpy_cnt != (size_t)-1) { 81 while (files_cnt--) 82 dd_in(); 83 } 84 85 dd_close(); 86 exit(0); 87 } 88 89 static void 90 setup(void) 91 { 92 #ifndef NO_CONV 93 u_int cnt; 94 #endif 95 96 if (in.name == NULL) { 97 in.name = "stdin"; 98 in.fd = STDIN_FILENO; 99 } else { 100 in.fd = open(in.name, O_RDONLY, 0); 101 if (in.fd < 0) 102 err(1, "%s", in.name); 103 } 104 105 getfdtype(&in); 106 107 if (files_cnt > 1 && !(in.flags & ISTAPE)) 108 errx(1, "files is not supported for non-tape devices"); 109 110 if (out.name == NULL) { 111 /* No way to check for read access here. */ 112 out.fd = STDOUT_FILENO; 113 out.name = "stdout"; 114 } else { 115 #define OFLAGS \ 116 (O_CREAT | (ddflags & (C_SEEK | C_NOTRUNC) ? 0 : O_TRUNC)) 117 out.fd = open(out.name, O_RDWR | OFLAGS, DEFFILEMODE); 118 /* 119 * May not have read access, so try again with write only. 120 * Without read we may have a problem if output also does 121 * not support seeks. 122 */ 123 if (out.fd < 0) { 124 out.fd = open(out.name, O_WRONLY | OFLAGS, DEFFILEMODE); 125 out.flags |= NOREAD; 126 } 127 if (out.fd < 0) 128 err(1, "%s", out.name); 129 } 130 131 getfdtype(&out); 132 133 /* 134 * Allocate space for the input and output buffers. If not doing 135 * record oriented I/O, only need a single buffer. 136 */ 137 if (!(ddflags & (C_BLOCK|C_UNBLOCK))) { 138 if ((in.db = malloc(out.dbsz + in.dbsz - 1)) == NULL) 139 err(1, "input buffer"); 140 out.db = in.db; 141 } else if ((in.db = 142 malloc((u_int)(MAX(in.dbsz, cbsz) + cbsz))) == NULL || 143 (out.db = malloc((u_int)(out.dbsz + cbsz))) == NULL) 144 err(1, "output buffer"); 145 in.dbp = in.db; 146 out.dbp = out.db; 147 148 /* Position the input/output streams. */ 149 if (in.offset) 150 pos_in(); 151 if (out.offset) 152 pos_out(); 153 154 /* 155 * Truncate the output file; ignore errors because it fails on some 156 * kinds of output files, tapes, for example. 157 */ 158 if ((ddflags & (C_OF | C_SEEK | C_NOTRUNC)) == (C_OF | C_SEEK)) 159 (void)ftruncate(out.fd, out.offset * out.dbsz); 160 161 /* 162 * If converting case at the same time as another conversion, build a 163 * table that does both at once. If just converting case, use the 164 * built-in tables. 165 */ 166 if (ddflags & (C_LCASE|C_UCASE)) { 167 #ifdef NO_CONV 168 /* Should not get here, but just in case... */ 169 errx(1, "case conv and -DNO_CONV"); 170 #else /* NO_CONV */ 171 if (ddflags & C_ASCII || ddflags & C_EBCDIC) { 172 if (ddflags & C_LCASE) { 173 for (cnt = 0; cnt < 0377; ++cnt) 174 casetab[cnt] = tolower(ctab[cnt]); 175 } else { 176 for (cnt = 0; cnt < 0377; ++cnt) 177 casetab[cnt] = toupper(ctab[cnt]); 178 } 179 } else { 180 if (ddflags & C_LCASE) { 181 for (cnt = 0; cnt < 0377; ++cnt) 182 casetab[cnt] = tolower(cnt); 183 } else { 184 for (cnt = 0; cnt < 0377; ++cnt) 185 casetab[cnt] = toupper(cnt); 186 } 187 } 188 189 ctab = casetab; 190 #endif /* NO_CONV */ 191 } 192 193 /* Statistics timestamp. */ 194 (void)gettimeofday(&st.startv, (struct timezone *)NULL); 195 } 196 197 static void 198 getfdtype(IO *io) 199 { 200 struct mtget mt; 201 struct stat sb; 202 203 if (fstat(io->fd, &sb)) 204 err(1, "%s", io->name); 205 if (S_ISCHR(sb.st_mode)) 206 io->flags |= ioctl(io->fd, MTIOCGET, &mt) ? ISCHR : ISTAPE; 207 else if (lseek(io->fd, (off_t)0, SEEK_CUR) == -1 && errno == ESPIPE) 208 io->flags |= ISPIPE; /* XXX fixed in 4.4BSD */ 209 } 210 211 static void 212 dd_in(void) 213 { 214 ssize_t n; 215 216 for (;;) { 217 if (cpy_cnt && (st.in_full + st.in_part) >= cpy_cnt) 218 return; 219 220 /* 221 * Zero the buffer first if sync; if doing block operations 222 * use spaces. 223 */ 224 if (ddflags & C_SYNC) { 225 if (ddflags & (C_BLOCK|C_UNBLOCK)) 226 (void)memset(in.dbp, ' ', in.dbsz); 227 else 228 (void)memset(in.dbp, 0, in.dbsz); 229 } 230 231 n = read(in.fd, in.dbp, in.dbsz); 232 if (n == 0) { 233 in.dbrcnt = 0; 234 return; 235 } 236 237 /* Read error. */ 238 if (n < 0) { 239 /* 240 * If noerror not specified, die. POSIX requires that 241 * the warning message be followed by an I/O display. 242 */ 243 if (!(ddflags & C_NOERROR)) 244 err(1, "%s", in.name); 245 warn("%s", in.name); 246 summary(); 247 248 /* 249 * If it's not a tape drive or a pipe, seek past the 250 * error. If your OS doesn't do the right thing for 251 * raw disks this section should be modified to re-read 252 * in sector size chunks. 253 */ 254 if (!(in.flags & (ISPIPE|ISTAPE)) && 255 lseek(in.fd, (off_t)in.dbsz, SEEK_CUR)) 256 warn("%s", in.name); 257 258 /* If sync not specified, omit block and continue. */ 259 if (!(ddflags & C_SYNC)) 260 continue; 261 262 /* Read errors count as full blocks. */ 263 in.dbcnt += in.dbrcnt = in.dbsz; 264 ++st.in_full; 265 266 /* Handle full input blocks. */ 267 } else if (n == in.dbsz) { 268 in.dbcnt += in.dbrcnt = n; 269 ++st.in_full; 270 271 /* Handle partial input blocks. */ 272 } else { 273 /* If sync, use the entire block. */ 274 if (ddflags & C_SYNC) 275 in.dbcnt += in.dbrcnt = in.dbsz; 276 else 277 in.dbcnt += in.dbrcnt = n; 278 ++st.in_part; 279 } 280 281 /* 282 * POSIX states that if bs is set and no other conversions 283 * than noerror, notrunc or sync are specified, the block 284 * is output without buffering as it is read. 285 */ 286 if (ddflags & C_BS) { 287 out.dbcnt = in.dbcnt; 288 dd_out(1); 289 in.dbcnt = 0; 290 continue; 291 } 292 293 if (ddflags & C_SWAB) { 294 if ((n = in.dbcnt) & 1) { 295 ++st.swab; 296 --n; 297 } 298 swab(in.dbp, in.dbp, n); 299 } 300 301 in.dbp += in.dbrcnt; 302 (*cfunc)(); 303 } 304 } 305 306 /* 307 * Cleanup any remaining I/O and flush output. If necessary, output file 308 * is truncated. 309 */ 310 static void 311 dd_close(void) 312 { 313 if (cfunc == def) 314 def_close(); 315 else if (cfunc == block) 316 block_close(); 317 else if (cfunc == unblock) 318 unblock_close(); 319 if (ddflags & C_OSYNC && out.dbcnt && out.dbcnt < out.dbsz) { 320 if (ddflags & (C_BLOCK|C_UNBLOCK)) 321 memset(out.dbp, ' ', out.dbsz - out.dbcnt); 322 else 323 memset(out.dbp, 0, out.dbsz - out.dbcnt); 324 out.dbcnt = out.dbsz; 325 } 326 if (out.dbcnt) 327 dd_out(1); 328 } 329 330 void 331 dd_out(int force) 332 { 333 static int warned; 334 size_t cnt, n; 335 ssize_t nw; 336 u_char *outp; 337 338 /* 339 * Write one or more blocks out. The common case is writing a full 340 * output block in a single write; increment the full block stats. 341 * Otherwise, we're into partial block writes. If a partial write, 342 * and it's a character device, just warn. If a tape device, quit. 343 * 344 * The partial writes represent two cases. 1: Where the input block 345 * was less than expected so the output block was less than expected. 346 * 2: Where the input block was the right size but we were forced to 347 * write the block in multiple chunks. The original versions of dd(1) 348 * never wrote a block in more than a single write, so the latter case 349 * never happened. 350 * 351 * One special case is if we're forced to do the write -- in that case 352 * we play games with the buffer size, and it's usually a partial write. 353 */ 354 outp = out.db; 355 for (n = force ? out.dbcnt : out.dbsz;; n = out.dbsz) { 356 for (cnt = n;; cnt -= nw) { 357 nw = write(out.fd, outp, cnt); 358 if (nw <= 0) { 359 if (nw == 0) 360 errx(1, "%s: end of device", out.name); 361 if (errno != EINTR) 362 err(1, "%s", out.name); 363 nw = 0; 364 } 365 outp += nw; 366 st.bytes += nw; 367 if (nw == n) { 368 if (n != out.dbsz) 369 ++st.out_part; 370 else 371 ++st.out_full; 372 break; 373 } 374 ++st.out_part; 375 if (nw == cnt) 376 break; 377 if (out.flags & ISCHR && !warned) { 378 warned = 1; 379 warnx("%s: short write on character device", 380 out.name); 381 } 382 if (out.flags & ISTAPE) 383 errx(1, "%s: short write on tape device", out.name); 384 } 385 if ((out.dbcnt -= n) < out.dbsz) 386 break; 387 } 388 389 /* Reassemble the output block. */ 390 if (out.dbcnt) 391 (void)memmove(out.db, out.dbp - out.dbcnt, out.dbcnt); 392 out.dbp = out.db + out.dbcnt; 393 } 394