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
46 void
ierr(const char * fname)47 ierr(const char *fname)
48 {
49 warn("%s", fname);
50 rval = 1;
51 }
52
53 void
oerr(void)54 oerr(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 */
63 int
mapprint(struct mapinfo * mip,off_t startoff,off_t len)64 mapprint(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 */
89 int
maparound(struct mapinfo * mip,off_t offset)90 maparound(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