1 /* $OpenBSD: getnetnamadr.c,v 1.9 2015/01/16 16:48:51 deraadt 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/param.h> /* ALIGN */
19 #include <sys/types.h>
20 #include <sys/socket.h>
21 #include <netinet/in.h>
22 #include <netdb.h>
23
24 #include <asr.h>
25 #include <errno.h>
26 #include <resolv.h>
27 #include <stdlib.h>
28 #include <string.h>
29
30 static void _fillnetent(const struct netent *, struct netent *, char *buf,
31 size_t);
32
33 static struct netent _netent;
34 static char _entbuf[4096];
35
36 static char *_empty[] = { NULL, };
37
38 static void
_fillnetent(const struct netent * e,struct netent * r,char * buf,size_t len)39 _fillnetent(const struct netent *e, struct netent *r, char *buf, size_t len)
40 {
41 char **ptr, *end, *pos;
42 size_t n, i;
43 int naliases;
44
45 bzero(buf, len);
46 bzero(r, sizeof(*r));
47 r->n_aliases = _empty;
48
49 end = buf + len;
50 ptr = (char **)ALIGN(buf);
51
52 if ((char *)ptr >= end)
53 return;
54
55 for (naliases = 0; e->n_aliases[naliases]; naliases++)
56 ;
57
58 r->n_name = NULL;
59 r->n_addrtype = e->n_addrtype;
60 r->n_net = e->n_net;
61 r->n_aliases = ptr;
62
63 pos = (char *)(ptr + (naliases + 1));
64 if (pos > end)
65 r->n_aliases = _empty;
66
67 n = strlcpy(pos, e->n_name, end - pos);
68 if (n >= end - pos)
69 return;
70 r->n_name = pos;
71 pos += n + 1;
72
73 for (i = 0; i < naliases; i++) {
74 n = strlcpy(pos, e->n_aliases[i], end - pos);
75 if (n >= end - pos)
76 return;
77 r->n_aliases[i] = pos;
78 pos += n + 1;
79 }
80 }
81
82 struct netent *
getnetbyname(const char * name)83 getnetbyname(const char *name)
84 {
85 struct asr_query *as;
86 struct asr_result ar;
87
88 res_init();
89
90 as = getnetbyname_async(name, NULL);
91 if (as == NULL) {
92 h_errno = NETDB_INTERNAL;
93 return (NULL);
94 }
95
96 asr_run_sync(as, &ar);
97
98 errno = ar.ar_errno;
99 h_errno = ar.ar_h_errno;
100 if (ar.ar_netent == NULL)
101 return (NULL);
102
103 _fillnetent(ar.ar_netent, &_netent, _entbuf, sizeof(_entbuf));
104 free(ar.ar_netent);
105
106 return (&_netent);
107 }
108
109 struct netent *
getnetbyaddr(in_addr_t net,int type)110 getnetbyaddr(in_addr_t net, int type)
111 {
112 struct asr_query *as;
113 struct asr_result ar;
114
115 res_init();
116
117 as = getnetbyaddr_async(net, type, NULL);
118 if (as == NULL) {
119 h_errno = NETDB_INTERNAL;
120 return (NULL);
121 }
122
123 asr_run_sync(as, &ar);
124
125 errno = ar.ar_errno;
126 h_errno = ar.ar_h_errno;
127 if (ar.ar_netent == NULL)
128 return (NULL);
129
130 _fillnetent(ar.ar_netent, &_netent, _entbuf, sizeof(_entbuf));
131 free(ar.ar_netent);
132
133 return (&_netent);
134 }
135