1 /* $OpenBSD: dd.c,v 1.23 2015/10/09 01:37:06 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/types.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 #define MAXIMUM(a, b) (((a) > (b)) ? (a) : (b)) 61 62 IO in, out; /* input/output state */ 63 STAT st; /* statistics */ 64 void (*cfunc)(void); /* conversion function */ 65 size_t cpy_cnt; /* # of blocks to copy */ 66 u_int ddflags; /* conversion options */ 67 size_t cbsz; /* conversion block size */ 68 size_t files_cnt = 1; /* # of files to copy */ 69 const u_char *ctab; /* conversion table */ 70 71 int 72 main(int argc, char *argv[]) 73 { 74 jcl(argv); 75 setup(); 76 77 (void)signal(SIGINFO, summaryx); 78 (void)signal(SIGINT, terminate); 79 80 atexit(summary); 81 82 if (cpy_cnt != (size_t)-1) { 83 while (files_cnt--) 84 dd_in(); 85 } 86 87 dd_close(); 88 exit(0); 89 } 90 91 static void 92 setup(void) 93 { 94 if (in.name == NULL) { 95 in.name = "stdin"; 96 in.fd = STDIN_FILENO; 97 } else { 98 in.fd = open(in.name, O_RDONLY, 0); 99 if (in.fd < 0) 100 err(1, "%s", in.name); 101 } 102 103 getfdtype(&in); 104 105 if (files_cnt > 1 && !(in.flags & ISTAPE)) 106 errx(1, "files is not supported for non-tape devices"); 107 108 if (out.name == NULL) { 109 /* No way to check for read access here. */ 110 out.fd = STDOUT_FILENO; 111 out.name = "stdout"; 112 } else { 113 #define OFLAGS \ 114 (O_CREAT | (ddflags & (C_SEEK | C_NOTRUNC) ? 0 : O_TRUNC)) 115 out.fd = open(out.name, O_RDWR | OFLAGS, DEFFILEMODE); 116 /* 117 * May not have read access, so try again with write only. 118 * Without read we may have a problem if output also does 119 * not support seeks. 120 */ 121 if (out.fd < 0) { 122 out.fd = open(out.name, O_WRONLY | OFLAGS, DEFFILEMODE); 123 out.flags |= NOREAD; 124 } 125 if (out.fd < 0) 126 err(1, "%s", out.name); 127 } 128 129 getfdtype(&out); 130 131 /* 132 * Allocate space for the input and output buffers. If not doing 133 * record oriented I/O, only need a single buffer. 134 */ 135 if (!(ddflags & (C_BLOCK|C_UNBLOCK))) { 136 if ((in.db = malloc(out.dbsz + in.dbsz - 1)) == NULL) 137 err(1, "input buffer"); 138 out.db = in.db; 139 } else if ((in.db = 140 malloc((u_int)(MAXIMUM(in.dbsz, cbsz) + cbsz))) == NULL || 141 (out.db = malloc((u_int)(out.dbsz + cbsz))) == NULL) 142 err(1, "output buffer"); 143 in.dbp = in.db; 144 out.dbp = out.db; 145 146 /* Position the input/output streams. */ 147 if (in.offset) 148 pos_in(); 149 if (out.offset) 150 pos_out(); 151 152 if (pledge("stdio", NULL) == -1) 153 err(1, "pledge"); 154 155 /* 156 * Truncate the output file; ignore errors because it fails on some 157 * kinds of output files, tapes, for example. 158 */ 159 if ((ddflags & (C_OF | C_SEEK | C_NOTRUNC)) == (C_OF | C_SEEK)) 160 (void)ftruncate(out.fd, out.offset * out.dbsz); 161 162 /* 163 * If converting case at the same time as another conversion, build a 164 * table that does both at once. If just converting case, use the 165 * built-in tables. 166 */ 167 if (ddflags & (C_LCASE|C_UCASE)) { 168 #ifdef NO_CONV 169 /* Should not get here, but just in case... */ 170 errx(1, "case conv and -DNO_CONV"); 171 #else /* NO_CONV */ 172 u_int cnt; 173 if (ddflags & C_ASCII || ddflags & C_EBCDIC) { 174 if (ddflags & C_LCASE) { 175 for (cnt = 0; cnt < 0377; ++cnt) 176 casetab[cnt] = tolower(ctab[cnt]); 177 } else { 178 for (cnt = 0; cnt < 0377; ++cnt) 179 casetab[cnt] = toupper(ctab[cnt]); 180 } 181 } else { 182 if (ddflags & C_LCASE) { 183 for (cnt = 0; cnt < 0377; ++cnt) 184 casetab[cnt] = tolower(cnt); 185 } else { 186 for (cnt = 0; cnt < 0377; ++cnt) 187 casetab[cnt] = toupper(cnt); 188 } 189 } 190 191 ctab = casetab; 192 #endif /* NO_CONV */ 193 } 194 195 /* Statistics timestamp. */ 196 (void)gettimeofday(&st.startv, (struct timezone *)NULL); 197 } 198 199 static void 200 getfdtype(IO *io) 201 { 202 struct mtget mt; 203 struct stat sb; 204 205 if (fstat(io->fd, &sb)) 206 err(1, "%s", io->name); 207 if (S_ISCHR(sb.st_mode)) 208 io->flags |= ioctl(io->fd, MTIOCGET, &mt) ? ISCHR : ISTAPE; 209 if (S_ISFIFO(sb.st_mode) || S_ISSOCK(sb.st_mode)) 210 io->flags |= ISPIPE; 211 } 212 213 static void 214 swapbytes(void *v, size_t len) 215 { 216 unsigned char *p = v; 217 unsigned char t; 218 219 while (len > 1) { 220 t = p[0]; 221 p[0] = p[1]; 222 p[1] = t; 223 p += 2; 224 len -= 2; 225 } 226 } 227 228 229 static void 230 dd_in(void) 231 { 232 ssize_t n; 233 234 for (;;) { 235 if (cpy_cnt && (st.in_full + st.in_part) >= cpy_cnt) 236 return; 237 238 /* 239 * Zero the buffer first if sync; if doing block operations 240 * use spaces. 241 */ 242 if (ddflags & C_SYNC) { 243 if (ddflags & (C_BLOCK|C_UNBLOCK)) 244 (void)memset(in.dbp, ' ', in.dbsz); 245 else 246 (void)memset(in.dbp, 0, in.dbsz); 247 } 248 249 n = read(in.fd, in.dbp, in.dbsz); 250 if (n == 0) { 251 in.dbrcnt = 0; 252 return; 253 } 254 255 /* Read error. */ 256 if (n < 0) { 257 /* 258 * If noerror not specified, die. POSIX requires that 259 * the warning message be followed by an I/O display. 260 */ 261 if (!(ddflags & C_NOERROR)) 262 err(1, "%s", in.name); 263 warn("%s", in.name); 264 summary(); 265 266 /* 267 * If it's not a tape drive or a pipe, seek past the 268 * error. If your OS doesn't do the right thing for 269 * raw disks this section should be modified to re-read 270 * in sector size chunks. 271 */ 272 if (!(in.flags & (ISPIPE|ISTAPE)) && 273 lseek(in.fd, (off_t)in.dbsz, SEEK_CUR)) 274 warn("%s", in.name); 275 276 /* If sync not specified, omit block and continue. */ 277 if (!(ddflags & C_SYNC)) 278 continue; 279 280 /* Read errors count as full blocks. */ 281 in.dbcnt += in.dbrcnt = in.dbsz; 282 ++st.in_full; 283 284 /* Handle full input blocks. */ 285 } else if (n == in.dbsz) { 286 in.dbcnt += in.dbrcnt = n; 287 ++st.in_full; 288 289 /* Handle partial input blocks. */ 290 } else { 291 /* If sync, use the entire block. */ 292 if (ddflags & C_SYNC) 293 in.dbcnt += in.dbrcnt = in.dbsz; 294 else 295 in.dbcnt += in.dbrcnt = n; 296 ++st.in_part; 297 } 298 299 /* 300 * POSIX states that if bs is set and no other conversions 301 * than noerror, notrunc or sync are specified, the block 302 * is output without buffering as it is read. 303 */ 304 if (ddflags & C_BS) { 305 out.dbcnt = in.dbcnt; 306 dd_out(1); 307 in.dbcnt = 0; 308 continue; 309 } 310 311 if (ddflags & C_SWAB) { 312 if ((n = in.dbrcnt) & 1) { 313 ++st.swab; 314 --n; 315 } 316 swapbytes(in.dbp, n); 317 } 318 319 in.dbp += in.dbrcnt; 320 (*cfunc)(); 321 } 322 } 323 324 /* 325 * Cleanup any remaining I/O and flush output. If necessary, output file 326 * is truncated. 327 */ 328 static void 329 dd_close(void) 330 { 331 if (cfunc == def) 332 def_close(); 333 else if (cfunc == block) 334 block_close(); 335 else if (cfunc == unblock) 336 unblock_close(); 337 if (ddflags & C_OSYNC && out.dbcnt && out.dbcnt < out.dbsz) { 338 if (ddflags & (C_BLOCK|C_UNBLOCK)) 339 memset(out.dbp, ' ', out.dbsz - out.dbcnt); 340 else 341 memset(out.dbp, 0, out.dbsz - out.dbcnt); 342 out.dbcnt = out.dbsz; 343 } 344 if (out.dbcnt) 345 dd_out(1); 346 } 347 348 void 349 dd_out(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