1/*
2 * Copyright (c) 1991, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * Edward Sze-Tyan Wang.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 4. Neither the name of the University nor the names of its contributors
17 *    may be used to endorse or promote products derived from this software
18 *    without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33#include <sys/types.h>
34#include <sys/stat.h>
35#include <sys/mman.h>
36
37#include <err.h>
38#include <errno.h>
39#include <stdio.h>
40#include <stdlib.h>
41#include <string.h>
42#include <unistd.h>
43
44#include "extern.h"
45
46void
47ierr(const char *fname)
48{
49	warn("%s", fname);
50	rval = 1;
51}
52
53void
54oerr(void)
55{
56	err(1, "stdout");
57}
58
59/*
60 * Print `len' bytes from the file associated with `mip', starting at
61 * absolute file offset `startoff'. May move map window.
62 */
63int
64mapprint(struct mapinfo *mip, off_t startoff, off_t len)
65{
66	int n;
67
68	while (len > 0) {
69		if (startoff < mip->mapoff || startoff >= mip->mapoff +
70		    (off_t)mip->maplen) {
71			if (maparound(mip, startoff) != 0)
72				return (1);
73		}
74		n = (mip->mapoff + mip->maplen) - startoff;
75		if (n > len)
76			n = len;
77		WR(mip->start + (startoff - mip->mapoff), n);
78		startoff += n;
79		len -= n;
80	}
81	return (0);
82}
83
84/*
85 * Move the map window so that it contains the byte at absolute file
86 * offset `offset'. The start of the map window will be TAILMAPLEN
87 * aligned.
88 */
89int
90maparound(struct mapinfo *mip, off_t offset)
91{
92
93	if (mip->start != NULL && munmap(mip->start, mip->maplen) != 0)
94		return (1);
95
96	mip->mapoff = offset & ~((off_t)TAILMAPLEN - 1);
97	mip->maplen = TAILMAPLEN;
98	if ((off_t)mip->maplen > mip->maxoff - mip->mapoff)
99		mip->maplen = mip->maxoff - mip->mapoff;
100	if (mip->maplen == 0)
101		abort();
102	if ((mip->start = mmap(NULL, mip->maplen, PROT_READ, MAP_SHARED,
103	    mip->fd, mip->mapoff)) == MAP_FAILED)
104		return (1);
105
106	return (0);
107}
108