1 /* $NetBSD: forward.c,v 1.1 2024/02/18 20:57:31 christos Exp $ */
2
3 /*
4 * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
5 *
6 * SPDX-License-Identifier: MPL-2.0
7 *
8 * This Source Code Form is subject to the terms of the Mozilla Public
9 * License, v. 2.0. If a copy of the MPL was not distributed with this
10 * file, you can obtain one at https://mozilla.org/MPL/2.0/.
11 *
12 * See the COPYRIGHT file distributed with this work for additional
13 * information regarding copyright ownership.
14 */
15
16 /*! \file */
17
18 #include <isc/magic.h>
19 #include <isc/mem.h>
20 #include <isc/rwlock.h>
21 #include <isc/util.h>
22
23 #include <dns/forward.h>
24 #include <dns/rbt.h>
25 #include <dns/result.h>
26 #include <dns/types.h>
27
28 struct dns_fwdtable {
29 /* Unlocked. */
30 unsigned int magic;
31 isc_mem_t *mctx;
32 isc_rwlock_t rwlock;
33 /* Locked by lock. */
34 dns_rbt_t *table;
35 };
36
37 #define FWDTABLEMAGIC ISC_MAGIC('F', 'w', 'd', 'T')
38 #define VALID_FWDTABLE(ft) ISC_MAGIC_VALID(ft, FWDTABLEMAGIC)
39
40 static void
41 auto_detach(void *, void *);
42
43 isc_result_t
dns_fwdtable_create(isc_mem_t * mctx,dns_fwdtable_t ** fwdtablep)44 dns_fwdtable_create(isc_mem_t *mctx, dns_fwdtable_t **fwdtablep) {
45 dns_fwdtable_t *fwdtable;
46 isc_result_t result;
47
48 REQUIRE(fwdtablep != NULL && *fwdtablep == NULL);
49
50 fwdtable = isc_mem_get(mctx, sizeof(*fwdtable));
51
52 fwdtable->table = NULL;
53 result = dns_rbt_create(mctx, auto_detach, fwdtable, &fwdtable->table);
54 if (result != ISC_R_SUCCESS) {
55 goto cleanup_fwdtable;
56 }
57
58 isc_rwlock_init(&fwdtable->rwlock, 0, 0);
59 fwdtable->mctx = NULL;
60 isc_mem_attach(mctx, &fwdtable->mctx);
61 fwdtable->magic = FWDTABLEMAGIC;
62 *fwdtablep = fwdtable;
63
64 return (ISC_R_SUCCESS);
65
66 cleanup_fwdtable:
67 isc_mem_put(mctx, fwdtable, sizeof(*fwdtable));
68
69 return (result);
70 }
71
72 isc_result_t
dns_fwdtable_addfwd(dns_fwdtable_t * fwdtable,const dns_name_t * name,dns_forwarderlist_t * fwdrs,dns_fwdpolicy_t fwdpolicy)73 dns_fwdtable_addfwd(dns_fwdtable_t *fwdtable, const dns_name_t *name,
74 dns_forwarderlist_t *fwdrs, dns_fwdpolicy_t fwdpolicy) {
75 isc_result_t result;
76 dns_forwarders_t *forwarders;
77 dns_forwarder_t *fwd, *nfwd;
78
79 REQUIRE(VALID_FWDTABLE(fwdtable));
80
81 forwarders = isc_mem_get(fwdtable->mctx, sizeof(*forwarders));
82
83 ISC_LIST_INIT(forwarders->fwdrs);
84 for (fwd = ISC_LIST_HEAD(*fwdrs); fwd != NULL;
85 fwd = ISC_LIST_NEXT(fwd, link))
86 {
87 nfwd = isc_mem_get(fwdtable->mctx, sizeof(*nfwd));
88 *nfwd = *fwd;
89 ISC_LINK_INIT(nfwd, link);
90 ISC_LIST_APPEND(forwarders->fwdrs, nfwd, link);
91 }
92 forwarders->fwdpolicy = fwdpolicy;
93
94 RWLOCK(&fwdtable->rwlock, isc_rwlocktype_write);
95 result = dns_rbt_addname(fwdtable->table, name, forwarders);
96 RWUNLOCK(&fwdtable->rwlock, isc_rwlocktype_write);
97
98 if (result != ISC_R_SUCCESS) {
99 goto cleanup;
100 }
101
102 return (ISC_R_SUCCESS);
103
104 cleanup:
105 while (!ISC_LIST_EMPTY(forwarders->fwdrs)) {
106 fwd = ISC_LIST_HEAD(forwarders->fwdrs);
107 ISC_LIST_UNLINK(forwarders->fwdrs, fwd, link);
108 isc_mem_put(fwdtable->mctx, fwd, sizeof(*fwd));
109 }
110 isc_mem_put(fwdtable->mctx, forwarders, sizeof(*forwarders));
111 return (result);
112 }
113
114 isc_result_t
dns_fwdtable_add(dns_fwdtable_t * fwdtable,const dns_name_t * name,isc_sockaddrlist_t * addrs,dns_fwdpolicy_t fwdpolicy)115 dns_fwdtable_add(dns_fwdtable_t *fwdtable, const dns_name_t *name,
116 isc_sockaddrlist_t *addrs, dns_fwdpolicy_t fwdpolicy) {
117 isc_result_t result;
118 dns_forwarders_t *forwarders;
119 dns_forwarder_t *fwd;
120 isc_sockaddr_t *sa;
121
122 REQUIRE(VALID_FWDTABLE(fwdtable));
123
124 forwarders = isc_mem_get(fwdtable->mctx, sizeof(*forwarders));
125
126 ISC_LIST_INIT(forwarders->fwdrs);
127 for (sa = ISC_LIST_HEAD(*addrs); sa != NULL;
128 sa = ISC_LIST_NEXT(sa, link))
129 {
130 fwd = isc_mem_get(fwdtable->mctx, sizeof(*fwd));
131 fwd->addr = *sa;
132 fwd->dscp = -1;
133 ISC_LINK_INIT(fwd, link);
134 ISC_LIST_APPEND(forwarders->fwdrs, fwd, link);
135 }
136 forwarders->fwdpolicy = fwdpolicy;
137
138 RWLOCK(&fwdtable->rwlock, isc_rwlocktype_write);
139 result = dns_rbt_addname(fwdtable->table, name, forwarders);
140 RWUNLOCK(&fwdtable->rwlock, isc_rwlocktype_write);
141
142 if (result != ISC_R_SUCCESS) {
143 goto cleanup;
144 }
145
146 return (ISC_R_SUCCESS);
147
148 cleanup:
149 while (!ISC_LIST_EMPTY(forwarders->fwdrs)) {
150 fwd = ISC_LIST_HEAD(forwarders->fwdrs);
151 ISC_LIST_UNLINK(forwarders->fwdrs, fwd, link);
152 isc_mem_put(fwdtable->mctx, fwd, sizeof(*fwd));
153 }
154 isc_mem_put(fwdtable->mctx, forwarders, sizeof(*forwarders));
155 return (result);
156 }
157
158 isc_result_t
dns_fwdtable_delete(dns_fwdtable_t * fwdtable,const dns_name_t * name)159 dns_fwdtable_delete(dns_fwdtable_t *fwdtable, const dns_name_t *name) {
160 isc_result_t result;
161
162 REQUIRE(VALID_FWDTABLE(fwdtable));
163
164 RWLOCK(&fwdtable->rwlock, isc_rwlocktype_write);
165 result = dns_rbt_deletename(fwdtable->table, name, false);
166 RWUNLOCK(&fwdtable->rwlock, isc_rwlocktype_write);
167
168 if (result == DNS_R_PARTIALMATCH) {
169 result = ISC_R_NOTFOUND;
170 }
171
172 return (result);
173 }
174
175 isc_result_t
dns_fwdtable_find(dns_fwdtable_t * fwdtable,const dns_name_t * name,dns_name_t * foundname,dns_forwarders_t ** forwardersp)176 dns_fwdtable_find(dns_fwdtable_t *fwdtable, const dns_name_t *name,
177 dns_name_t *foundname, dns_forwarders_t **forwardersp) {
178 isc_result_t result;
179
180 REQUIRE(VALID_FWDTABLE(fwdtable));
181
182 RWLOCK(&fwdtable->rwlock, isc_rwlocktype_read);
183
184 result = dns_rbt_findname(fwdtable->table, name, 0, foundname,
185 (void **)forwardersp);
186 if (result == DNS_R_PARTIALMATCH) {
187 result = ISC_R_SUCCESS;
188 }
189
190 RWUNLOCK(&fwdtable->rwlock, isc_rwlocktype_read);
191
192 return (result);
193 }
194
195 void
dns_fwdtable_destroy(dns_fwdtable_t ** fwdtablep)196 dns_fwdtable_destroy(dns_fwdtable_t **fwdtablep) {
197 dns_fwdtable_t *fwdtable;
198
199 REQUIRE(fwdtablep != NULL && VALID_FWDTABLE(*fwdtablep));
200
201 fwdtable = *fwdtablep;
202 *fwdtablep = NULL;
203
204 dns_rbt_destroy(&fwdtable->table);
205 isc_rwlock_destroy(&fwdtable->rwlock);
206 fwdtable->magic = 0;
207
208 isc_mem_putanddetach(&fwdtable->mctx, fwdtable, sizeof(*fwdtable));
209 }
210
211 /***
212 *** Private
213 ***/
214
215 static void
auto_detach(void * data,void * arg)216 auto_detach(void *data, void *arg) {
217 dns_forwarders_t *forwarders = data;
218 dns_fwdtable_t *fwdtable = arg;
219 dns_forwarder_t *fwd;
220
221 UNUSED(arg);
222
223 while (!ISC_LIST_EMPTY(forwarders->fwdrs)) {
224 fwd = ISC_LIST_HEAD(forwarders->fwdrs);
225 ISC_LIST_UNLINK(forwarders->fwdrs, fwd, link);
226 isc_mem_put(fwdtable->mctx, fwd, sizeof(*fwd));
227 }
228 isc_mem_put(fwdtable->mctx, forwarders, sizeof(*forwarders));
229 }
230