1 /* $OpenBSD: dd.c,v 1.18 2013/06/01 16:46:49 tedu 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 if (in.name == NULL) { 93 in.name = "stdin"; 94 in.fd = STDIN_FILENO; 95 } else { 96 in.fd = open(in.name, O_RDONLY, 0); 97 if (in.fd < 0) 98 err(1, "%s", in.name); 99 } 100 101 getfdtype(&in); 102 103 if (files_cnt > 1 && !(in.flags & ISTAPE)) 104 errx(1, "files is not supported for non-tape devices"); 105 106 if (out.name == NULL) { 107 /* No way to check for read access here. */ 108 out.fd = STDOUT_FILENO; 109 out.name = "stdout"; 110 } else { 111 #define OFLAGS \ 112 (O_CREAT | (ddflags & (C_SEEK | C_NOTRUNC) ? 0 : O_TRUNC)) 113 out.fd = open(out.name, O_RDWR | OFLAGS, DEFFILEMODE); 114 /* 115 * May not have read access, so try again with write only. 116 * Without read we may have a problem if output also does 117 * not support seeks. 118 */ 119 if (out.fd < 0) { 120 out.fd = open(out.name, O_WRONLY | OFLAGS, DEFFILEMODE); 121 out.flags |= NOREAD; 122 } 123 if (out.fd < 0) 124 err(1, "%s", out.name); 125 } 126 127 getfdtype(&out); 128 129 /* 130 * Allocate space for the input and output buffers. If not doing 131 * record oriented I/O, only need a single buffer. 132 */ 133 if (!(ddflags & (C_BLOCK|C_UNBLOCK))) { 134 if ((in.db = malloc(out.dbsz + in.dbsz - 1)) == NULL) 135 err(1, "input buffer"); 136 out.db = in.db; 137 } else if ((in.db = 138 malloc((u_int)(MAX(in.dbsz, cbsz) + cbsz))) == NULL || 139 (out.db = malloc((u_int)(out.dbsz + cbsz))) == NULL) 140 err(1, "output buffer"); 141 in.dbp = in.db; 142 out.dbp = out.db; 143 144 /* Position the input/output streams. */ 145 if (in.offset) 146 pos_in(); 147 if (out.offset) 148 pos_out(); 149 150 /* 151 * Truncate the output file; ignore errors because it fails on some 152 * kinds of output files, tapes, for example. 153 */ 154 if ((ddflags & (C_OF | C_SEEK | C_NOTRUNC)) == (C_OF | C_SEEK)) 155 (void)ftruncate(out.fd, out.offset * out.dbsz); 156 157 /* 158 * If converting case at the same time as another conversion, build a 159 * table that does both at once. If just converting case, use the 160 * built-in tables. 161 */ 162 if (ddflags & (C_LCASE|C_UCASE)) { 163 #ifdef NO_CONV 164 /* Should not get here, but just in case... */ 165 errx(1, "case conv and -DNO_CONV"); 166 #else /* NO_CONV */ 167 u_int cnt; 168 if (ddflags & C_ASCII || ddflags & C_EBCDIC) { 169 if (ddflags & C_LCASE) { 170 for (cnt = 0; cnt < 0377; ++cnt) 171 casetab[cnt] = tolower(ctab[cnt]); 172 } else { 173 for (cnt = 0; cnt < 0377; ++cnt) 174 casetab[cnt] = toupper(ctab[cnt]); 175 } 176 } else { 177 if (ddflags & C_LCASE) { 178 for (cnt = 0; cnt < 0377; ++cnt) 179 casetab[cnt] = tolower(cnt); 180 } else { 181 for (cnt = 0; cnt < 0377; ++cnt) 182 casetab[cnt] = toupper(cnt); 183 } 184 } 185 186 ctab = casetab; 187 #endif /* NO_CONV */ 188 } 189 190 /* Statistics timestamp. */ 191 (void)gettimeofday(&st.startv, (struct timezone *)NULL); 192 } 193 194 static void 195 getfdtype(IO *io) 196 { 197 struct mtget mt; 198 struct stat sb; 199 200 if (fstat(io->fd, &sb)) 201 err(1, "%s", io->name); 202 if (S_ISCHR(sb.st_mode)) 203 io->flags |= ioctl(io->fd, MTIOCGET, &mt) ? ISCHR : ISTAPE; 204 if (S_ISFIFO(sb.st_mode) || S_ISSOCK(sb.st_mode)) 205 io->flags |= ISPIPE; 206 } 207 208 static void 209 dd_in(void) 210 { 211 ssize_t n; 212 213 for (;;) { 214 if (cpy_cnt && (st.in_full + st.in_part) >= cpy_cnt) 215 return; 216 217 /* 218 * Zero the buffer first if sync; if doing block operations 219 * use spaces. 220 */ 221 if (ddflags & C_SYNC) { 222 if (ddflags & (C_BLOCK|C_UNBLOCK)) 223 (void)memset(in.dbp, ' ', in.dbsz); 224 else 225 (void)memset(in.dbp, 0, in.dbsz); 226 } 227 228 n = read(in.fd, in.dbp, in.dbsz); 229 if (n == 0) { 230 in.dbrcnt = 0; 231 return; 232 } 233 234 /* Read error. */ 235 if (n < 0) { 236 /* 237 * If noerror not specified, die. POSIX requires that 238 * the warning message be followed by an I/O display. 239 */ 240 if (!(ddflags & C_NOERROR)) 241 err(1, "%s", in.name); 242 warn("%s", in.name); 243 summary(); 244 245 /* 246 * If it's not a tape drive or a pipe, seek past the 247 * error. If your OS doesn't do the right thing for 248 * raw disks this section should be modified to re-read 249 * in sector size chunks. 250 */ 251 if (!(in.flags & (ISPIPE|ISTAPE)) && 252 lseek(in.fd, (off_t)in.dbsz, SEEK_CUR)) 253 warn("%s", in.name); 254 255 /* If sync not specified, omit block and continue. */ 256 if (!(ddflags & C_SYNC)) 257 continue; 258 259 /* Read errors count as full blocks. */ 260 in.dbcnt += in.dbrcnt = in.dbsz; 261 ++st.in_full; 262 263 /* Handle full input blocks. */ 264 } else if (n == in.dbsz) { 265 in.dbcnt += in.dbrcnt = n; 266 ++st.in_full; 267 268 /* Handle partial input blocks. */ 269 } else { 270 /* If sync, use the entire block. */ 271 if (ddflags & C_SYNC) 272 in.dbcnt += in.dbrcnt = in.dbsz; 273 else 274 in.dbcnt += in.dbrcnt = n; 275 ++st.in_part; 276 } 277 278 /* 279 * POSIX states that if bs is set and no other conversions 280 * than noerror, notrunc or sync are specified, the block 281 * is output without buffering as it is read. 282 */ 283 if (ddflags & C_BS) { 284 out.dbcnt = in.dbcnt; 285 dd_out(1); 286 in.dbcnt = 0; 287 continue; 288 } 289 290 if (ddflags & C_SWAB) { 291 if ((n = in.dbcnt) & 1) { 292 ++st.swab; 293 --n; 294 } 295 swab(in.dbp, in.dbp, n); 296 } 297 298 in.dbp += in.dbrcnt; 299 (*cfunc)(); 300 } 301 } 302 303 /* 304 * Cleanup any remaining I/O and flush output. If necessary, output file 305 * is truncated. 306 */ 307 static void 308 dd_close(void) 309 { 310 if (cfunc == def) 311 def_close(); 312 else if (cfunc == block) 313 block_close(); 314 else if (cfunc == unblock) 315 unblock_close(); 316 if (ddflags & C_OSYNC && out.dbcnt && out.dbcnt < out.dbsz) { 317 if (ddflags & (C_BLOCK|C_UNBLOCK)) 318 memset(out.dbp, ' ', out.dbsz - out.dbcnt); 319 else 320 memset(out.dbp, 0, out.dbsz - out.dbcnt); 321 out.dbcnt = out.dbsz; 322 } 323 if (out.dbcnt) 324 dd_out(1); 325 } 326 327 void 328 dd_out(int force) 329 { 330 static int warned; 331 size_t cnt, n; 332 ssize_t nw; 333 u_char *outp; 334 335 /* 336 * Write one or more blocks out. The common case is writing a full 337 * output block in a single write; increment the full block stats. 338 * Otherwise, we're into partial block writes. If a partial write, 339 * and it's a character device, just warn. If a tape device, quit. 340 * 341 * The partial writes represent two cases. 1: Where the input block 342 * was less than expected so the output block was less than expected. 343 * 2: Where the input block was the right size but we were forced to 344 * write the block in multiple chunks. The original versions of dd(1) 345 * never wrote a block in more than a single write, so the latter case 346 * never happened. 347 * 348 * One special case is if we're forced to do the write -- in that case 349 * we play games with the buffer size, and it's usually a partial write. 350 */ 351 outp = out.db; 352 for (n = force ? out.dbcnt : out.dbsz;; n = out.dbsz) { 353 for (cnt = n;; cnt -= nw) { 354 nw = write(out.fd, outp, cnt); 355 if (nw <= 0) { 356 if (nw == 0) 357 errx(1, "%s: end of device", out.name); 358 if (errno != EINTR) 359 err(1, "%s", out.name); 360 nw = 0; 361 } 362 outp += nw; 363 st.bytes += nw; 364 if (nw == n) { 365 if (n != out.dbsz) 366 ++st.out_part; 367 else 368 ++st.out_full; 369 break; 370 } 371 ++st.out_part; 372 if (nw == cnt) 373 break; 374 if (out.flags & ISCHR && !warned) { 375 warned = 1; 376 warnx("%s: short write on character device", 377 out.name); 378 } 379 if (out.flags & ISTAPE) 380 errx(1, "%s: short write on tape device", out.name); 381 } 382 if ((out.dbcnt -= n) < out.dbsz) 383 break; 384 } 385 386 /* Reassemble the output block. */ 387 if (out.dbcnt) 388 (void)memmove(out.db, out.dbp - out.dbcnt, out.dbcnt); 389 out.dbp = out.db + out.dbcnt; 390 } 391