dd.c revision 1.6
1 /* $NetBSD: dd.c,v 1.6 1996/02/20 19:29:06 jtc Exp $ */ 2 3 /*- 4 * Copyright (c) 1991, 1993, 1994 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Keith Muller of the University of California, San Diego and Lance 9 * Visser of Convex Computer Corporation. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. All advertising materials mentioning features or use of this software 20 * must display the following acknowledgement: 21 * This product includes software developed by the University of 22 * California, Berkeley and its contributors. 23 * 4. Neither the name of the University nor the names of its contributors 24 * may be used to endorse or promote products derived from this software 25 * without specific prior written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 30 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 37 * SUCH DAMAGE. 38 */ 39 40 #ifndef lint 41 static char copyright[] = 42 "@(#) Copyright (c) 1991, 1993, 1994\n\ 43 The Regents of the University of California. All rights reserved.\n"; 44 #endif /* not lint */ 45 46 #ifndef lint 47 #if 0 48 static char sccsid[] = "@(#)dd.c 8.5 (Berkeley) 4/2/94"; 49 #else 50 static char rcsid[] = "$NetBSD: dd.c,v 1.6 1996/02/20 19:29:06 jtc Exp $"; 51 #endif 52 #endif /* not lint */ 53 54 #include <sys/param.h> 55 #include <sys/stat.h> 56 #include <sys/ioctl.h> 57 #include <sys/mtio.h> 58 59 #include <ctype.h> 60 #include <err.h> 61 #include <errno.h> 62 #include <fcntl.h> 63 #include <signal.h> 64 #include <stdio.h> 65 #include <stdlib.h> 66 #include <string.h> 67 #include <unistd.h> 68 69 #include "dd.h" 70 #include "extern.h" 71 72 static void dd_close __P((void)); 73 static void dd_in __P((void)); 74 static void getfdtype __P((IO *)); 75 static void setup __P((void)); 76 77 IO in, out; /* input/output state */ 78 STAT st; /* statistics */ 79 void (*cfunc) __P((void)); /* conversion function */ 80 u_long cpy_cnt; /* # of blocks to copy */ 81 u_int ddflags; /* conversion options */ 82 u_int cbsz; /* conversion block size */ 83 u_int files_cnt = 1; /* # of files to copy */ 84 const u_char *ctab; /* conversion table */ 85 86 int 87 main(argc, argv) 88 int argc; 89 char *argv[]; 90 { 91 jcl(argv); 92 setup(); 93 94 (void)signal(SIGINFO, summaryx); 95 (void)signal(SIGINT, terminate); 96 97 atexit(summary); 98 99 while (files_cnt--) 100 dd_in(); 101 102 dd_close(); 103 exit(0); 104 } 105 106 static void 107 setup() 108 { 109 u_int cnt; 110 111 if (in.name == NULL) { 112 in.name = "stdin"; 113 in.fd = STDIN_FILENO; 114 } else { 115 in.fd = open(in.name, O_RDONLY, 0); 116 if (in.fd < 0) 117 err(1, "%s", in.name); 118 } 119 120 getfdtype(&in); 121 122 if (files_cnt > 1 && !(in.flags & ISTAPE)) 123 errx(1, "files is not supported for non-tape devices"); 124 125 if (out.name == NULL) { 126 /* No way to check for read access here. */ 127 out.fd = STDOUT_FILENO; 128 out.name = "stdout"; 129 } else { 130 #define OFLAGS \ 131 (O_CREAT | (ddflags & (C_SEEK | C_NOTRUNC) ? 0 : O_TRUNC)) 132 out.fd = open(out.name, O_RDWR | OFLAGS, DEFFILEMODE); 133 /* 134 * May not have read access, so try again with write only. 135 * Without read we may have a problem if output also does 136 * not support seeks. 137 */ 138 if (out.fd < 0) { 139 out.fd = open(out.name, O_WRONLY | OFLAGS, DEFFILEMODE); 140 out.flags |= NOREAD; 141 } 142 if (out.fd < 0) 143 err(1, "%s", out.name); 144 } 145 146 getfdtype(&out); 147 148 /* 149 * Allocate space for the input and output buffers. If not doing 150 * record oriented I/O, only need a single buffer. 151 */ 152 if (!(ddflags & (C_BLOCK|C_UNBLOCK))) { 153 if ((in.db = malloc(out.dbsz + in.dbsz - 1)) == NULL) 154 err(1, NULL); 155 out.db = in.db; 156 } else if ((in.db = 157 malloc((u_int)(MAX(in.dbsz, cbsz) + cbsz))) == NULL || 158 (out.db = malloc((u_int)(out.dbsz + cbsz))) == NULL) 159 err(1, NULL); 160 in.dbp = in.db; 161 out.dbp = out.db; 162 163 /* Position the input/output streams. */ 164 if (in.offset) 165 pos_in(); 166 if (out.offset) 167 pos_out(); 168 169 /* 170 * Truncate the output file; ignore errors because it fails on some 171 * kinds of output files, tapes, for example. 172 */ 173 if (ddflags & (C_OF | C_SEEK | C_NOTRUNC) == (C_OF | C_SEEK)) 174 (void)ftruncate(out.fd, (off_t)out.offset * out.dbsz); 175 176 /* 177 * If converting case at the same time as another conversion, build a 178 * table that does both at once. If just converting case, use the 179 * built-in tables. 180 */ 181 if (ddflags & (C_LCASE|C_UCASE)) { 182 #ifdef NO_CONV 183 /* Should not get here, but just in case... */ 184 errx(1, "case conv and -DNO_CONV"); 185 #else /* NO_CONV */ 186 if (ddflags & C_ASCII || ddflags & C_EBCDIC) { 187 if (ddflags & C_LCASE) { 188 for (cnt = 0; cnt < 0377; ++cnt) 189 casetab[cnt] = tolower(ctab[cnt]); 190 } else { 191 for (cnt = 0; cnt < 0377; ++cnt) 192 casetab[cnt] = toupper(ctab[cnt]); 193 } 194 } else { 195 if (ddflags & C_LCASE) { 196 for (cnt = 0; cnt < 0377; ++cnt) 197 casetab[cnt] = tolower(cnt); 198 } else { 199 for (cnt = 0; cnt < 0377; ++cnt) 200 casetab[cnt] = toupper(cnt); 201 } 202 } 203 204 ctab = casetab; 205 #endif /* NO_CONV */ 206 } 207 208 (void)time(&st.start); /* Statistics timestamp. */ 209 } 210 211 static void 212 getfdtype(io) 213 IO *io; 214 { 215 struct mtget mt; 216 struct stat sb; 217 218 if (fstat(io->fd, &sb)) 219 err(1, "%s", io->name); 220 if (S_ISCHR(sb.st_mode)) 221 io->flags |= ioctl(io->fd, MTIOCGET, &mt) ? ISCHR : ISTAPE; 222 else if (lseek(io->fd, (off_t)0, SEEK_CUR) == -1 && errno == ESPIPE) 223 io->flags |= ISPIPE; /* XXX fixed in 4.4BSD */ 224 } 225 226 static void 227 dd_in() 228 { 229 int flags, n; 230 231 for (flags = ddflags;;) { 232 if (cpy_cnt && (st.in_full + st.in_part) >= cpy_cnt) 233 return; 234 235 /* 236 * Zero the buffer first if trying to recover from errors so 237 * lose the minimum amount of data. If doing block operations 238 * use spaces. 239 */ 240 if ((flags & (C_NOERROR|C_SYNC)) == (C_NOERROR|C_SYNC)) 241 if (flags & (C_BLOCK|C_UNBLOCK)) 242 memset(in.dbp, ' ', in.dbsz); 243 else 244 memset(in.dbp, 0, in.dbsz); 245 246 n = read(in.fd, in.dbp, in.dbsz); 247 if (n == 0) { 248 in.dbrcnt = 0; 249 return; 250 } 251 252 /* Read error. */ 253 if (n < 0) { 254 /* 255 * If noerror not specified, die. POSIX requires that 256 * the warning message be followed by an I/O display. 257 */ 258 if (!(flags & C_NOERROR)) 259 err(1, "%s", in.name); 260 warn("%s", in.name); 261 summary(); 262 263 /* 264 * If it's not a tape drive or a pipe, seek past the 265 * error. If your OS doesn't do the right thing for 266 * raw disks this section should be modified to re-read 267 * in sector size chunks. 268 */ 269 if (!(in.flags & (ISPIPE|ISTAPE)) && 270 lseek(in.fd, (off_t)in.dbsz, SEEK_CUR)) 271 warn("%s", in.name); 272 273 /* If sync not specified, omit block and continue. */ 274 if (!(ddflags & C_SYNC)) 275 continue; 276 277 /* Read errors count as full blocks. */ 278 in.dbcnt += in.dbrcnt = in.dbsz; 279 ++st.in_full; 280 281 /* Handle full input blocks. */ 282 } else if (n == in.dbsz) { 283 in.dbcnt += in.dbrcnt = n; 284 ++st.in_full; 285 286 /* Handle partial input blocks. */ 287 } else { 288 /* If sync, use the entire block. */ 289 if (ddflags & C_SYNC) 290 in.dbcnt += in.dbrcnt = in.dbsz; 291 else 292 in.dbcnt += in.dbrcnt = n; 293 ++st.in_part; 294 } 295 296 /* 297 * POSIX states that if bs is set and no other conversions 298 * than noerror, notrunc or sync are specified, the block 299 * is output without buffering as it is read. 300 */ 301 if (ddflags & C_BS) { 302 out.dbcnt = in.dbcnt; 303 dd_out(1); 304 in.dbcnt = 0; 305 continue; 306 } 307 308 if (ddflags & C_SWAB) { 309 if ((n = in.dbcnt) & 1) { 310 ++st.swab; 311 --n; 312 } 313 swab(in.dbp, in.dbp, n); 314 } 315 316 in.dbp += in.dbrcnt; 317 (*cfunc)(); 318 } 319 } 320 321 /* 322 * Cleanup any remaining I/O and flush output. If necesssary, output file 323 * is truncated. 324 */ 325 static void 326 dd_close() 327 { 328 if (cfunc == def) 329 def_close(); 330 else if (cfunc == block) 331 block_close(); 332 else if (cfunc == unblock) 333 unblock_close(); 334 if (ddflags & C_OSYNC && out.dbcnt < out.dbsz) { 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(force) 344 int force; 345 { 346 static int warned; 347 int cnt, n, 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 memmove(out.db, out.dbp - out.dbcnt, out.dbcnt); 404 out.dbp = out.db + out.dbcnt; 405 } 406
Indexes created Wed Sep 24 15:09:51 GMT 2025