1 /*
2 * SysDB - src/plugins/cname/dns.c
3 * Copyright (C) 2013 Sebastian 'tokkee' Harl <sh@tokkee.org>
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
17 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
18 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR
19 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
20 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
22 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
23 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
24 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
25 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
28 #include "sysdb.h"
29 #include "core/plugin.h"
30 #include "core/error.h"
32 #include <assert.h>
33 #include <string.h>
34 #include <syslog.h>
36 #include <sys/types.h>
37 #include <sys/socket.h>
38 #include <netdb.h>
40 /* make it a no-op if necessary */
41 #ifndef AI_IDN
42 # define AI_IDN 0
43 #endif
45 SDB_PLUGIN_MAGIC;
47 /*
48 * plugin API
49 */
51 static char *
52 sdb_dns_cname(const char *name,
53 sdb_object_t __attribute__((unused)) *user_data)
54 {
55 struct addrinfo hints;
56 struct addrinfo *ret = NULL;
57 char *cname;
58 int err;
60 memset(&hints, 0, sizeof(hints));
61 hints.ai_family = AF_UNSPEC;
62 hints.ai_flags = AI_CANONNAME | AI_IDN;
64 err = getaddrinfo(name, /* service = */ NULL, &hints, &ret);
65 if (err) {
66 /* XXX: what to do about EAI_AGAIN? */
67 sdb_plugin_logf(SDB_LOG_ERR, "cname::dns: Failed to resolve '%s': %s",
68 name, gai_strerror(err));
69 return NULL;
70 }
72 if ((! ret) || (! ret->ai_canonname))
73 return NULL;
75 cname = strdup(ret->ai_canonname);
76 freeaddrinfo(ret);
77 return cname;
78 } /* sdb_dns_cname */
80 int
81 sdb_module_init(sdb_plugin_info_t *info)
82 {
83 sdb_plugin_set_info(info, SDB_PLUGIN_INFO_NAME, "cname::dns");
84 sdb_plugin_set_info(info, SDB_PLUGIN_INFO_DESC,
85 "canonicalize hostnames by querying DNS");
86 sdb_plugin_set_info(info, SDB_PLUGIN_INFO_COPYRIGHT,
87 "Copyright (C) 2013 Sebastian 'tokkee' Harl <sh@tokkee.org>");
88 sdb_plugin_set_info(info, SDB_PLUGIN_INFO_LICENSE, "BSD");
89 sdb_plugin_set_info(info, SDB_PLUGIN_INFO_VERSION, SDB_VERSION);
90 sdb_plugin_set_info(info, SDB_PLUGIN_INFO_PLUGIN_VERSION, SDB_VERSION);
92 sdb_plugin_register_cname("cname::dns", sdb_dns_cname, NULL);
93 return 0;
94 } /* sdb_module_init */
96 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */