1 /* $NetBSD: forward.c,v 1.9 2024/02/21 22:52:06 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/result.h> 21 #include <isc/rwlock.h> 22 #include <isc/util.h> 23 24 #include <dns/forward.h> 25 #include <dns/rbt.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 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 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 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 ISC_LINK_INIT(fwd, link); 133 ISC_LIST_APPEND(forwarders->fwdrs, fwd, link); 134 } 135 forwarders->fwdpolicy = fwdpolicy; 136 137 RWLOCK(&fwdtable->rwlock, isc_rwlocktype_write); 138 result = dns_rbt_addname(fwdtable->table, name, forwarders); 139 RWUNLOCK(&fwdtable->rwlock, isc_rwlocktype_write); 140 141 if (result != ISC_R_SUCCESS) { 142 goto cleanup; 143 } 144 145 return (ISC_R_SUCCESS); 146 147 cleanup: 148 while (!ISC_LIST_EMPTY(forwarders->fwdrs)) { 149 fwd = ISC_LIST_HEAD(forwarders->fwdrs); 150 ISC_LIST_UNLINK(forwarders->fwdrs, fwd, link); 151 isc_mem_put(fwdtable->mctx, fwd, sizeof(*fwd)); 152 } 153 isc_mem_put(fwdtable->mctx, forwarders, sizeof(*forwarders)); 154 return (result); 155 } 156 157 isc_result_t 158 dns_fwdtable_delete(dns_fwdtable_t *fwdtable, const dns_name_t *name) { 159 isc_result_t result; 160 161 REQUIRE(VALID_FWDTABLE(fwdtable)); 162 163 RWLOCK(&fwdtable->rwlock, isc_rwlocktype_write); 164 result = dns_rbt_deletename(fwdtable->table, name, false); 165 RWUNLOCK(&fwdtable->rwlock, isc_rwlocktype_write); 166 167 return (result); 168 } 169 170 isc_result_t 171 dns_fwdtable_find(dns_fwdtable_t *fwdtable, const dns_name_t *name, 172 dns_name_t *foundname, dns_forwarders_t **forwardersp) { 173 isc_result_t result; 174 175 REQUIRE(VALID_FWDTABLE(fwdtable)); 176 177 RWLOCK(&fwdtable->rwlock, isc_rwlocktype_read); 178 result = dns_rbt_findname(fwdtable->table, name, 0, foundname, 179 (void **)forwardersp); 180 RWUNLOCK(&fwdtable->rwlock, isc_rwlocktype_read); 181 182 return (result); 183 } 184 185 void 186 dns_fwdtable_destroy(dns_fwdtable_t **fwdtablep) { 187 dns_fwdtable_t *fwdtable; 188 189 REQUIRE(fwdtablep != NULL && VALID_FWDTABLE(*fwdtablep)); 190 191 fwdtable = *fwdtablep; 192 *fwdtablep = NULL; 193 194 dns_rbt_destroy(&fwdtable->table); 195 isc_rwlock_destroy(&fwdtable->rwlock); 196 fwdtable->magic = 0; 197 198 isc_mem_putanddetach(&fwdtable->mctx, fwdtable, sizeof(*fwdtable)); 199 } 200 201 /*** 202 *** Private 203 ***/ 204 205 static void 206 auto_detach(void *data, void *arg) { 207 dns_forwarders_t *forwarders = data; 208 dns_fwdtable_t *fwdtable = arg; 209 dns_forwarder_t *fwd; 210 211 UNUSED(arg); 212 213 while (!ISC_LIST_EMPTY(forwarders->fwdrs)) { 214 fwd = ISC_LIST_HEAD(forwarders->fwdrs); 215 ISC_LIST_UNLINK(forwarders->fwdrs, fwd, link); 216 isc_mem_put(fwdtable->mctx, fwd, sizeof(*fwd)); 217 } 218 isc_mem_put(fwdtable->mctx, forwarders, sizeof(*forwarders)); 219 } 220