1 /*
2  * Copyright (C) 2004, 2005, 2007, 2009  Internet Systems Consortium, Inc. ("ISC")
3  * Copyright (C) 1999-2001  Internet Software Consortium.
4  *
5  * Permission to use, copy, modify, and/or 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 ISC DISCLAIMS ALL WARRANTIES WITH
10  * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
11  * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
12  * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
13  * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
14  * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
15  * PERFORMANCE OF THIS SOFTWARE.
16  */
17 
18 /* $Id: lib.c,v 1.19 2009/09/03 00:12:23 each Exp $ */
19 
20 /*! \file */
21 
22 #include <config.h>
23 
24 #include <stddef.h>
25 
26 #include <isc/hash.h>
27 #include <isc/mem.h>
28 #include <isc/msgcat.h>
29 #include <isc/mutex.h>
30 #include <isc/once.h>
31 #include <isc/util.h>
32 
33 #include <dns/db.h>
34 #include <dns/ecdb.h>
35 #include <dns/lib.h>
36 #include <dns/result.h>
37 
38 #include <dst/dst.h>
39 
40 
41 /***
42  *** Globals
43  ***/
44 
45 LIBDNS_EXTERNAL_DATA unsigned int			dns_pps = 0U;
46 LIBDNS_EXTERNAL_DATA isc_msgcat_t *			dns_msgcat = NULL;
47 
48 
49 /***
50  *** Private
51  ***/
52 
53 static isc_once_t		msgcat_once = ISC_ONCE_INIT;
54 
55 
56 /***
57  *** Functions
58  ***/
59 
60 static void
open_msgcat(void)61 open_msgcat(void) {
62 	isc_msgcat_open("libdns.cat", &dns_msgcat);
63 }
64 
65 void
dns_lib_initmsgcat(void)66 dns_lib_initmsgcat(void) {
67 
68 	/*
69 	 * Initialize the DNS library's message catalog, dns_msgcat, if it
70 	 * has not already been initialized.
71 	 */
72 
73 	RUNTIME_CHECK(isc_once_do(&msgcat_once, open_msgcat) == ISC_R_SUCCESS);
74 }
75 
76 static isc_once_t init_once = ISC_ONCE_INIT;
77 static isc_mem_t *dns_g_mctx = NULL;
78 #ifndef BIND9
79 static dns_dbimplementation_t *dbimp = NULL;
80 #endif
81 static isc_boolean_t initialize_done = ISC_FALSE;
82 static isc_mutex_t reflock;
83 static unsigned int references = 0;
84 
85 static void
initialize(void)86 initialize(void) {
87 	isc_result_t result;
88 
89 	REQUIRE(initialize_done == ISC_FALSE);
90 
91 	result = isc_mem_create(0, 0, &dns_g_mctx);
92 	if (result != ISC_R_SUCCESS)
93 		return;
94 	dns_result_register();
95 #ifndef BIND9
96 	result = dns_ecdb_register(dns_g_mctx, &dbimp);
97 	if (result != ISC_R_SUCCESS)
98 		goto cleanup_mctx;
99 #endif
100 	result = isc_hash_create(dns_g_mctx, NULL, DNS_NAME_MAXWIRE);
101 	if (result != ISC_R_SUCCESS)
102 		goto cleanup_db;
103 
104 	result = dst_lib_init(dns_g_mctx, NULL, 0);
105 	if (result != ISC_R_SUCCESS)
106 		goto cleanup_hash;
107 
108 	result = isc_mutex_init(&reflock);
109 	if (result != ISC_R_SUCCESS)
110 		goto cleanup_dst;
111 
112 	initialize_done = ISC_TRUE;
113 	return;
114 
115   cleanup_dst:
116 	dst_lib_destroy();
117   cleanup_hash:
118 	isc_hash_destroy();
119   cleanup_db:
120 #ifndef BIND9
121 	dns_ecdb_unregister(&dbimp);
122   cleanup_mctx:
123 #endif
124 	isc_mem_detach(&dns_g_mctx);
125 }
126 
127 isc_result_t
dns_lib_init(void)128 dns_lib_init(void) {
129 	isc_result_t result;
130 
131 	/*
132 	 * Since this routine is expected to be used by a normal application,
133 	 * it should be better to return an error, instead of an emergency
134 	 * abort, on any failure.
135 	 */
136 	result = isc_once_do(&init_once, initialize);
137 	if (result != ISC_R_SUCCESS)
138 		return (result);
139 
140 	if (!initialize_done)
141 		return (ISC_R_FAILURE);
142 
143 	LOCK(&reflock);
144 	references++;
145 	UNLOCK(&reflock);
146 
147 	return (ISC_R_SUCCESS);
148 }
149 
150 void
dns_lib_shutdown(void)151 dns_lib_shutdown(void) {
152 	isc_boolean_t cleanup_ok = ISC_FALSE;
153 
154 	LOCK(&reflock);
155 	if (--references == 0)
156 		cleanup_ok = ISC_TRUE;
157 	UNLOCK(&reflock);
158 
159 	if (!cleanup_ok)
160 		return;
161 
162 	dst_lib_destroy();
163 	isc_hash_destroy();
164 #ifndef BIND9
165 	dns_ecdb_unregister(&dbimp);
166 #endif
167 	isc_mem_detach(&dns_g_mctx);
168 }
169