dd.c revision 1.4
1 /* $NetBSD: dd.c,v 1.4 1995/03/21 09:04:06 cgd 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 1.4 1995/03/21 09:04:06 cgd 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 if (ddflags & C_ASCII) 183 if (ddflags & C_LCASE) { 184 for (cnt = 0; cnt < 0377; ++cnt) 185 if (isupper(ctab[cnt])) 186 ctab[cnt] = tolower(ctab[cnt]); 187 } else { 188 for (cnt = 0; cnt < 0377; ++cnt) 189 if (islower(ctab[cnt])) 190 ctab[cnt] = toupper(ctab[cnt]); 191 } 192 else if (ddflags & C_EBCDIC) 193 if (ddflags & C_LCASE) { 194 for (cnt = 0; cnt < 0377; ++cnt) 195 if (isupper(cnt)) 196 ctab[cnt] = ctab[tolower(cnt)]; 197 } else { 198 for (cnt = 0; cnt < 0377; ++cnt) 199 if (islower(cnt)) 200 ctab[cnt] = ctab[toupper(cnt)]; 201 } 202 else 203 ctab = ddflags & C_LCASE ? u2l : l2u; 204 (void)time(&st.start); /* Statistics timestamp. */ 205 } 206 207 static void 208 getfdtype(io) 209 IO *io; 210 { 211 struct mtget mt; 212 struct stat sb; 213 214 if (fstat(io->fd, &sb)) 215 err(1, "%s", io->name); 216 if (S_ISCHR(sb.st_mode)) 217 io->flags |= ioctl(io->fd, MTIOCGET, &mt) ? ISCHR : ISTAPE; 218 else if (lseek(io->fd, (off_t)0, SEEK_CUR) == -1 && errno == ESPIPE) 219 io->flags |= ISPIPE; /* XXX fixed in 4.4BSD */ 220 } 221 222 static void 223 dd_in() 224 { 225 int flags, n; 226 227 for (flags = ddflags;;) { 228 if (cpy_cnt && (st.in_full + st.in_part) >= cpy_cnt) 229 return; 230 231 /* 232 * Zero the buffer first if trying to recover from errors so 233 * lose the minimum amount of data. If doing block operations 234 * use spaces. 235 */ 236 if ((flags & (C_NOERROR|C_SYNC)) == (C_NOERROR|C_SYNC)) 237 if (flags & (C_BLOCK|C_UNBLOCK)) 238 memset(in.dbp, ' ', in.dbsz); 239 else 240 memset(in.dbp, 0, in.dbsz); 241 242 n = read(in.fd, in.dbp, in.dbsz); 243 if (n == 0) { 244 in.dbrcnt = 0; 245 return; 246 } 247 248 /* Read error. */ 249 if (n < 0) { 250 /* 251 * If noerror not specified, die. POSIX requires that 252 * the warning message be followed by an I/O display. 253 */ 254 if (!(flags & C_NOERROR)) 255 err(1, "%s", in.name); 256 warn("%s", in.name); 257 summary(); 258 259 /* 260 * If it's not a tape drive or a pipe, seek past the 261 * error. If your OS doesn't do the right thing for 262 * raw disks this section should be modified to re-read 263 * in sector size chunks. 264 */ 265 if (!(in.flags & (ISPIPE|ISTAPE)) && 266 lseek(in.fd, (off_t)in.dbsz, SEEK_CUR)) 267 warn("%s", in.name); 268 269 /* If sync not specified, omit block and continue. */ 270 if (!(ddflags & C_SYNC)) 271 continue; 272 273 /* Read errors count as full blocks. */ 274 in.dbcnt += in.dbrcnt = in.dbsz; 275 ++st.in_full; 276 277 /* Handle full input blocks. */ 278 } else if (n == in.dbsz) { 279 in.dbcnt += in.dbrcnt = n; 280 ++st.in_full; 281 282 /* Handle partial input blocks. */ 283 } else { 284 /* If sync, use the entire block. */ 285 if (ddflags & C_SYNC) 286 in.dbcnt += in.dbrcnt = in.dbsz; 287 else 288 in.dbcnt += in.dbrcnt = n; 289 ++st.in_part; 290 } 291 292 /* 293 * POSIX states that if bs is set and no other conversions 294 * than noerror, notrunc or sync are specified, the block 295 * is output without buffering as it is read. 296 */ 297 if (ddflags & C_BS) { 298 out.dbcnt = in.dbcnt; 299 dd_out(1); 300 in.dbcnt = 0; 301 continue; 302 } 303 304 if (ddflags & C_SWAB) { 305 if ((n = in.dbcnt) & 1) { 306 ++st.swab; 307 --n; 308 } 309 swab(in.dbp, in.dbp, n); 310 } 311 312 in.dbp += in.dbrcnt; 313 (*cfunc)(); 314 } 315 } 316 317 /* 318 * Cleanup any remaining I/O and flush output. If necesssary, output file 319 * is truncated. 320 */ 321 static void 322 dd_close() 323 { 324 if (cfunc == def) 325 def_close(); 326 else if (cfunc == block) 327 block_close(); 328 else if (cfunc == unblock) 329 unblock_close(); 330 if (ddflags & C_OSYNC && out.dbcnt < out.dbsz) { 331 memset(out.dbp, 0, out.dbsz - out.dbcnt); 332 out.dbcnt = out.dbsz; 333 } 334 if (out.dbcnt) 335 dd_out(1); 336 } 337 338 void 339 dd_out(force) 340 int force; 341 { 342 static int warned; 343 int cnt, n, nw; 344 u_char *outp; 345 346 /* 347 * Write one or more blocks out. The common case is writing a full 348 * output block in a single write; increment the full block stats. 349 * Otherwise, we're into partial block writes. If a partial write, 350 * and it's a character device, just warn. If a tape device, quit. 351 * 352 * The partial writes represent two cases. 1: Where the input block 353 * was less than expected so the output block was less than expected. 354 * 2: Where the input block was the right size but we were forced to 355 * write the block in multiple chunks. The original versions of dd(1) 356 * never wrote a block in more than a single write, so the latter case 357 * never happened. 358 * 359 * One special case is if we're forced to do the write -- in that case 360 * we play games with the buffer size, and it's usually a partial write. 361 */ 362 outp = out.db; 363 for (n = force ? out.dbcnt : out.dbsz;; n = out.dbsz) { 364 for (cnt = n;; cnt -= nw) { 365 nw = write(out.fd, outp, cnt); 366 if (nw <= 0) { 367 if (nw == 0) 368 errx(1, "%s: end of device", out.name); 369 if (errno != EINTR) 370 err(1, "%s", out.name); 371 nw = 0; 372 } 373 outp += nw; 374 st.bytes += nw; 375 if (nw == n) { 376 if (n != out.dbsz) 377 ++st.out_part; 378 else 379 ++st.out_full; 380 break; 381 } 382 ++st.out_part; 383 if (nw == cnt) 384 break; 385 if (out.flags & ISCHR && !warned) { 386 warned = 1; 387 warnx("%s: short write on character device", 388 out.name); 389 } 390 if (out.flags & ISTAPE) 391 errx(1, "%s: short write on tape device", out.name); 392 } 393 if ((out.dbcnt -= n) < out.dbsz) 394 break; 395 } 396 397 /* Reassemble the output block. */ 398 if (out.dbcnt) 399 memmove(out.db, out.dbp - out.dbcnt, out.dbcnt); 400 out.dbp = out.db + out.dbcnt; 401 } 402
Indexes created Wed Sep 24 05:09:52 GMT 2025