xref: /openbsd-src/lib/libc/asr/getnetnamadr.c (revision b55974ed076dc056de6e8fcead6a3176b51ffd83)
1 /*	$OpenBSD: getnetnamadr.c,v 1.4 2013/04/04 17:50:19 eric Exp $	*/
2 /*
3  * Copyright (c) 2012 Eric Faurot <eric@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 
18 #include <sys/types.h>
19 #include <netinet/in.h>
20 
21 #include <errno.h>
22 #include <resolv.h>
23 #include <stdlib.h>
24 #include <string.h>
25 
26 #include "asr.h"
27 
28 static void _fillnetent(const struct netent *, struct netent *, char *buf,
29     size_t);
30 
31 static struct netent	 _netent;
32 static char		 _entbuf[4096];
33 
34 static char *_empty[] = { NULL, };
35 
36 static void
37 _fillnetent(const struct netent *e, struct netent *r, char *buf, size_t len)
38 {
39 	char	**ptr, *end, *pos;
40 	size_t	n, i;
41 	int	naliases;
42 
43 	bzero(buf, len);
44 	bzero(r, sizeof(*r));
45 	r->n_aliases = _empty;
46 
47 	end = buf + len;
48 	ptr = (char **)ALIGN(buf);
49 
50 	if ((char *)ptr >= end)
51 		return;
52 
53 	for (naliases = 0; e->n_aliases[naliases]; naliases++)
54 		;
55 
56 	r->n_name = NULL;
57 	r->n_addrtype = e->n_addrtype;
58 	r->n_net = e->n_net;
59 	r->n_aliases = ptr;
60 
61 	pos = (char *)(ptr + (naliases + 1));
62 	if (pos > end)
63 		r->n_aliases = _empty;
64 
65 	n = strlcpy(pos, e->n_name, end - pos);
66 	if (n >= end - pos)
67 		return;
68 	r->n_name = pos;
69 	pos += n + 1;
70 
71 	for (i = 0; i < naliases; i++) {
72 		n = strlcpy(pos, e->n_aliases[i], end - pos);
73 		if (n >= end - pos)
74 			return;
75 		r->n_aliases[i] = pos;
76 		pos += n + 1;
77 	}
78 }
79 
80 struct netent *
81 getnetbyname(const char *name)
82 {
83 	struct async	*as;
84 	struct async_res ar;
85 
86 	as = getnetbyname_async(name, NULL);
87 	if (as == NULL) {
88 		h_errno = NETDB_INTERNAL;
89 		return (NULL);
90 	}
91 
92 	async_run_sync(as, &ar);
93 
94 	errno = ar.ar_errno;
95 	h_errno = ar.ar_h_errno;
96 	if (ar.ar_netent == NULL)
97 		return (NULL);
98 
99 	_fillnetent(ar.ar_netent, &_netent, _entbuf, sizeof(_entbuf));
100 	free(ar.ar_netent);
101 
102 	return (&_netent);
103 }
104 
105 struct netent *
106 getnetbyaddr(in_addr_t net, int type)
107 {
108 	struct async	*as;
109 	struct async_res ar;
110 
111 	as = getnetbyaddr_async(net, type, NULL);
112 	if (as == NULL) {
113 		h_errno = NETDB_INTERNAL;
114 		return (NULL);
115 	}
116 
117 	async_run_sync(as, &ar);
118 
119 	errno = ar.ar_errno;
120 	h_errno = ar.ar_h_errno;
121 	if (ar.ar_netent == NULL)
122 		return (NULL);
123 
124 	_fillnetent(ar.ar_netent, &_netent, _entbuf, sizeof(_entbuf));
125 	free(ar.ar_netent);
126 
127 	return (&_netent);
128 }
129