Annotation of src/bin/dd/position.c, Revision 1.18
1.18 ! pooka 1: /* $NetBSD: position.c,v 1.17 2009/02/14 07:13:40 lukem Exp $ */
1.4 cgd 2:
1.1 glass 3: /*-
1.3 mycroft 4: * Copyright (c) 1991, 1993, 1994
5: * The Regents of the University of California. All rights reserved.
1.1 glass 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.
1.14 agc 19: * 3. Neither the name of the University nor the names of its contributors
1.1 glass 20: * may be used to endorse or promote products derived from this software
21: * without specific prior written permission.
22: *
23: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33: * SUCH DAMAGE.
34: */
35:
1.5 christos 36: #include <sys/cdefs.h>
1.1 glass 37: #ifndef lint
1.4 cgd 38: #if 0
39: static char sccsid[] = "@(#)position.c 8.3 (Berkeley) 4/2/94";
40: #else
1.18 ! pooka 41: __RCSID("$NetBSD: position.c,v 1.17 2009/02/14 07:13:40 lukem Exp $");
1.4 cgd 42: #endif
1.1 glass 43: #endif /* not lint */
44:
45: #include <sys/types.h>
46: #include <sys/stat.h>
47: #include <sys/ioctl.h>
48: #include <sys/mtio.h>
1.10 ross 49: #include <sys/time.h>
1.3 mycroft 50:
51: #include <err.h>
1.1 glass 52: #include <errno.h>
1.13 jschauma 53: #include <stdlib.h>
1.3 mycroft 54: #include <string.h>
1.1 glass 55: #include <unistd.h>
1.3 mycroft 56:
1.1 glass 57: #include "dd.h"
58: #include "extern.h"
59:
60: /*
61: * Position input/output data streams before starting the copy. Device type
62: * dependent. Seekable devices use lseek, and the rest position by reading.
63: * Seeking past the end of file can cause null blocks to be written to the
64: * output.
65: */
66: void
1.11 lukem 67: pos_in(void)
1.1 glass 68: {
1.3 mycroft 69: int bcnt, cnt, nr, warned;
1.1 glass 70:
1.8 jtk 71: /* If not a pipe or tape device, try to seek on it. */
1.7 mycroft 72: if (!(in.flags & (ISPIPE|ISTAPE))) {
1.18 ! pooka 73: if (ddop_lseek(in, in.fd,
1.13 jschauma 74: (off_t)in.offset * (off_t)in.dbsz, SEEK_CUR) == -1) {
1.16 jschauma 75: err(EXIT_FAILURE, "%s", in.name);
1.13 jschauma 76: /* NOTREACHED */
77: }
1.1 glass 78: return;
1.13 jschauma 79: /* NOTREACHED */
1.1 glass 80: }
81:
82: /*
83: * Read the data. If a pipe, read until satisfy the number of bytes
84: * being skipped. No differentiation for reading complete and partial
85: * blocks for other devices.
86: */
87: for (bcnt = in.dbsz, cnt = in.offset, warned = 0; cnt;) {
1.18 ! pooka 88: if ((nr = ddop_read(in, in.fd, in.db, bcnt)) > 0) {
1.1 glass 89: if (in.flags & ISPIPE) {
90: if (!(bcnt -= nr)) {
91: bcnt = in.dbsz;
92: --cnt;
93: }
94: } else
95: --cnt;
96: continue;
97: }
98:
99: if (nr == 0) {
100: if (files_cnt > 1) {
101: --files_cnt;
102: continue;
103: }
1.13 jschauma 104: errx(EXIT_FAILURE, "skip reached end of input");
105: /* NOTREACHED */
1.1 glass 106: }
107:
108: /*
109: * Input error -- either EOF with no more files, or I/O error.
110: * If noerror not set die. POSIX requires that the warning
111: * message be followed by an I/O display.
112: */
113: if (ddflags & C_NOERROR) {
114: if (!warned) {
1.15 kleink 115:
1.16 jschauma 116: warn("%s", in.name);
1.1 glass 117: warned = 1;
1.3 mycroft 118: summary();
1.1 glass 119: }
120: continue;
121: }
1.16 jschauma 122: err(EXIT_FAILURE, "%s", in.name);
1.13 jschauma 123: /* NOTREACHED */
1.1 glass 124: }
125: }
126:
127: void
1.11 lukem 128: pos_out(void)
1.1 glass 129: {
130: struct mtop t_op;
1.17 lukem 131: int n;
132: uint64_t cnt;
1.1 glass 133:
134: /*
135: * If not a tape, try seeking on the file. Seeking on a pipe is
136: * going to fail, but don't protect the user -- they shouldn't
137: * have specified the seek operand.
138: */
139: if (!(out.flags & ISTAPE)) {
1.18 ! pooka 140: if (ddop_lseek(out, out.fd,
1.6 phil 141: (off_t)out.offset * (off_t)out.dbsz, SEEK_SET) == -1)
1.16 jschauma 142: err(EXIT_FAILURE, "%s", out.name);
1.13 jschauma 143: /* NOTREACHED */
1.1 glass 144: return;
145: }
146:
147: /* If no read access, try using mtio. */
148: if (out.flags & NOREAD) {
149: t_op.mt_op = MTFSR;
150: t_op.mt_count = out.offset;
151:
1.18 ! pooka 152: if (ddop_ioctl(out, out.fd, MTIOCTOP, &t_op) < 0)
1.16 jschauma 153: err(EXIT_FAILURE, "%s", out.name);
1.13 jschauma 154: /* NOTREACHED */
1.1 glass 155: return;
156: }
157:
158: /* Read it. */
159: for (cnt = 0; cnt < out.offset; ++cnt) {
1.18 ! pooka 160: if ((n = ddop_read(out, out.fd, out.db, out.dbsz)) > 0)
1.1 glass 161: continue;
162:
163: if (n < 0)
1.16 jschauma 164: err(EXIT_FAILURE, "%s", out.name);
1.13 jschauma 165: /* NOTREACHED */
1.1 glass 166:
167: /*
168: * If reach EOF, fill with NUL characters; first, back up over
169: * the EOF mark. Note, cnt has not yet been incremented, so
170: * the EOF read does not count as a seek'd block.
171: */
172: t_op.mt_op = MTBSR;
173: t_op.mt_count = 1;
1.18 ! pooka 174: if (ddop_ioctl(out, out.fd, MTIOCTOP, &t_op) == -1)
1.16 jschauma 175: err(EXIT_FAILURE, "%s", out.name);
1.13 jschauma 176: /* NOTREACHED */
1.1 glass 177:
178: while (cnt++ < out.offset)
1.18 ! pooka 179: if ((uint64_t)(n = bwrite(&out,
! 180: out.db, out.dbsz)) != out.dbsz)
1.16 jschauma 181: err(EXIT_FAILURE, "%s", out.name);
1.13 jschauma 182: /* NOTREACHED */
1.1 glass 183: break;
184: }
185: }
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