dd.c revision 1.5
1 /* $NetBSD: dd.c,v 1.5 1995/10/08 23:01:24 gwr 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 1.5 1995/10/08 23:01:24 gwr 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 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) 187 if (ddflags & C_LCASE) { 188 for (cnt = 0; cnt < 0377; ++cnt) 189 if (isupper(ctab[cnt])) 190 ctab[cnt] = tolower(ctab[cnt]); 191 } else { 192 for (cnt = 0; cnt < 0377; ++cnt) 193 if (islower(ctab[cnt])) 194 ctab[cnt] = toupper(ctab[cnt]); 195 } 196 else if (ddflags & C_EBCDIC) 197 if (ddflags & C_LCASE) { 198 for (cnt = 0; cnt < 0377; ++cnt) 199 if (isupper(cnt)) 200 ctab[cnt] = ctab[tolower(cnt)]; 201 } else { 202 for (cnt = 0; cnt < 0377; ++cnt) 203 if (islower(cnt)) 204 ctab[cnt] = ctab[toupper(cnt)]; 205 } 206 else 207 ctab = ddflags & C_LCASE ? u2l : l2u; 208 #endif /* NO_CONV */ 209 } 210 211 (void)time(&st.start); /* Statistics timestamp. */ 212 } 213 214 static void 215 getfdtype(io) 216 IO *io; 217 { 218 struct mtget mt; 219 struct stat sb; 220 221 if (fstat(io->fd, &sb)) 222 err(1, "%s", io->name); 223 if (S_ISCHR(sb.st_mode)) 224 io->flags |= ioctl(io->fd, MTIOCGET, &mt) ? ISCHR : ISTAPE; 225 else if (lseek(io->fd, (off_t)0, SEEK_CUR) == -1 && errno == ESPIPE) 226 io->flags |= ISPIPE; /* XXX fixed in 4.4BSD */ 227 } 228 229 static void 230 dd_in() 231 { 232 int flags, n; 233 234 for (flags = ddflags;;) { 235 if (cpy_cnt && (st.in_full + st.in_part) >= cpy_cnt) 236 return; 237 238 /* 239 * Zero the buffer first if trying to recover from errors so 240 * lose the minimum amount of data. If doing block operations 241 * use spaces. 242 */ 243 if ((flags & (C_NOERROR|C_SYNC)) == (C_NOERROR|C_SYNC)) 244 if (flags & (C_BLOCK|C_UNBLOCK)) 245 memset(in.dbp, ' ', in.dbsz); 246 else 247 memset(in.dbp, 0, in.dbsz); 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 (!(flags & 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.dbcnt) & 1) { 313 ++st.swab; 314 --n; 315 } 316 swab(in.dbp, 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 necesssary, output file 326 * is truncated. 327 */ 328 static void 329 dd_close() 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.dbsz) { 338 memset(out.dbp, 0, out.dbsz - out.dbcnt); 339 out.dbcnt = out.dbsz; 340 } 341 if (out.dbcnt) 342 dd_out(1); 343 } 344 345 void 346 dd_out(force) 347 int force; 348 { 349 static int warned; 350 int cnt, n, nw; 351 u_char *outp; 352 353 /* 354 * Write one or more blocks out. The common case is writing a full 355 * output block in a single write; increment the full block stats. 356 * Otherwise, we're into partial block writes. If a partial write, 357 * and it's a character device, just warn. If a tape device, quit. 358 * 359 * The partial writes represent two cases. 1: Where the input block 360 * was less than expected so the output block was less than expected. 361 * 2: Where the input block was the right size but we were forced to 362 * write the block in multiple chunks. The original versions of dd(1) 363 * never wrote a block in more than a single write, so the latter case 364 * never happened. 365 * 366 * One special case is if we're forced to do the write -- in that case 367 * we play games with the buffer size, and it's usually a partial write. 368 */ 369 outp = out.db; 370 for (n = force ? out.dbcnt : out.dbsz;; n = out.dbsz) { 371 for (cnt = n;; cnt -= nw) { 372 nw = write(out.fd, outp, cnt); 373 if (nw <= 0) { 374 if (nw == 0) 375 errx(1, "%s: end of device", out.name); 376 if (errno != EINTR) 377 err(1, "%s", out.name); 378 nw = 0; 379 } 380 outp += nw; 381 st.bytes += nw; 382 if (nw == n) { 383 if (n != out.dbsz) 384 ++st.out_part; 385 else 386 ++st.out_full; 387 break; 388 } 389 ++st.out_part; 390 if (nw == cnt) 391 break; 392 if (out.flags & ISCHR && !warned) { 393 warned = 1; 394 warnx("%s: short write on character device", 395 out.name); 396 } 397 if (out.flags & ISTAPE) 398 errx(1, "%s: short write on tape device", out.name); 399 } 400 if ((out.dbcnt -= n) < out.dbsz) 401 break; 402 } 403 404 /* Reassemble the output block. */ 405 if (out.dbcnt) 406 memmove(out.db, out.dbp - out.dbcnt, out.dbcnt); 407 out.dbp = out.db + out.dbcnt; 408 } 409
Indexes created Tue Sep 23 22:09:46 GMT 2025