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 
29 int
30 main(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