1/*	$OpenBSD: mlinks.c,v 1.3 2016/11/05 16:43:50 schwarze Exp $ */
2/*
3 * Copyright (c) 2016 Ingo Schwarze <schwarze@openbsd.org>
4 *
5 * Permission to use, copy, modify, and distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16 *
17 * Some operating systems need MLINKS for pages with more than one name.
18 * Extract these in a format suitable for portable LibreSSL.
19 */
20#include <err.h>
21#include <regex.h>
22#include <stdint.h>
23#include <stdio.h>
24#include <string.h>
25
26#include "dbm_map.h"
27#include "dbm.h"
28
29int
30main(int argc, char *argv[])
31{
32	const int32_t	*pp;  /* Page record in the pages table. */
33	const char	*np;  /* Names of the page. */
34	const char	*fp;  /* Primary filename of the page. */
35	const char	*ep;  /* Filname extension including the dot. */
36	size_t		 flen, nlen;
37	int32_t		 i, npages;
38
39	if (argc != 2)
40		errx(1, "usage: mlinks filename");
41
42	if (dbm_open(argv[1]) == -1)
43		err(1, "%s", argv[1]);
44
45	pp = dbm_getint(4);
46	npages = be32toh(*pp++);
47	if (npages <= 0)
48		errx(1, "database empty or corrupt: %d pages", npages);
49
50	for (i = 0; i < npages; i++, pp += 5) {
51		np = dbm_get(pp[0]);
52		if (np == NULL)
53			errx(1, "database corrupt: bad name pointer");
54
55		/* Skip files with just one name. */
56		if (strchr(np, '\0')[1] == '\0')
57			continue;
58
59		fp = dbm_get(pp[4]);
60		if (fp == NULL)
61			errx(1, "database corrupt: bad file pointer");
62
63		/* Skip the file type byte. */
64		fp++;
65
66		/* Skip directory parts of filenames. */
67		ep = strrchr(fp, '/');
68		if (ep != NULL)
69			fp = ep + 1;
70
71		ep = strrchr(fp, '.');
72		if (ep == NULL)
73			errx(1, "no filename extension: %s", fp);
74		flen = ep - fp;
75
76		while (*np != '\0') {
77
78			/* Skip the name type byte. */
79			np++;
80
81			/* Skip the primary filename. */
82			nlen = strlen(np);
83			if (nlen == flen && strncmp(fp, np, nlen) == 0) {
84				np = strchr(np, '\0') + 1;
85				continue;
86			}
87
88			/* Describe the desired mlink. */
89			printf("%s,", fp);
90			while (*np != '\0')
91				putchar(*np++);
92			np++;
93			puts(ep);
94		}
95	}
96	dbm_close();
97	return 0;
98}
99