ares_parse_into_addrinfo.c (5839B)
1 /* MIT License 2 * 3 * Copyright (c) 2019 Andrew Selivanov 4 * Copyright (c) 2023 Brad House 5 * 6 * Permission is hereby granted, free of charge, to any person obtaining a copy 7 * of this software and associated documentation files (the "Software"), to deal 8 * in the Software without restriction, including without limitation the rights 9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 10 * copies of the Software, and to permit persons to whom the Software is 11 * furnished to do so, subject to the following conditions: 12 * 13 * The above copyright notice and this permission notice (including the next 14 * paragraph) shall be included in all copies or substantial portions of the 15 * Software. 16 * 17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 20 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 22 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 23 * SOFTWARE. 24 * 25 * SPDX-License-Identifier: MIT 26 */ 27 #include "ares_private.h" 28 29 #ifdef HAVE_NETINET_IN_H 30 # include <netinet/in.h> 31 #endif 32 #ifdef HAVE_NETDB_H 33 # include <netdb.h> 34 #endif 35 #ifdef HAVE_ARPA_INET_H 36 # include <arpa/inet.h> 37 #endif 38 39 #ifdef HAVE_STRINGS_H 40 # include <strings.h> 41 #endif 42 43 #ifdef HAVE_LIMITS_H 44 # include <limits.h> 45 #endif 46 47 48 ares_status_t ares_parse_into_addrinfo(const ares_dns_record_t *dnsrec, 49 ares_bool_t cname_only_is_enodata, 50 unsigned short port, 51 struct ares_addrinfo *ai) 52 { 53 ares_status_t status; 54 size_t i; 55 size_t ancount; 56 const char *hostname = NULL; 57 ares_bool_t got_a = ARES_FALSE; 58 ares_bool_t got_aaaa = ARES_FALSE; 59 ares_bool_t got_cname = ARES_FALSE; 60 struct ares_addrinfo_cname *cnames = NULL; 61 struct ares_addrinfo_node *nodes = NULL; 62 63 /* Save question hostname */ 64 status = ares_dns_record_query_get(dnsrec, 0, &hostname, NULL, NULL); 65 if (status != ARES_SUCCESS) { 66 goto done; /* LCOV_EXCL_LINE: DefensiveCoding */ 67 } 68 69 ancount = ares_dns_record_rr_cnt(dnsrec, ARES_SECTION_ANSWER); 70 if (ancount == 0) { 71 status = ARES_ENODATA; 72 goto done; 73 } 74 75 for (i = 0; i < ancount; i++) { 76 ares_dns_rec_type_t rtype; 77 const ares_dns_rr_t *rr = 78 ares_dns_record_rr_get_const(dnsrec, ARES_SECTION_ANSWER, i); 79 80 if (ares_dns_rr_get_class(rr) != ARES_CLASS_IN) { 81 continue; 82 } 83 84 rtype = ares_dns_rr_get_type(rr); 85 86 /* Issue #683 87 * Old code did this hostname sanity check, however it appears this is 88 * flawed logic. Other resolvers don't do this sanity check. Leaving 89 * this code commented out for future reference. 90 * 91 * rname = ares_dns_rr_get_name(rr); 92 * if ((rtype == ARES_REC_TYPE_A || rtype == ARES_REC_TYPE_AAAA) && 93 * !ares_strcaseeq(rname, hostname)) { 94 * continue; 95 * } 96 */ 97 98 if (rtype == ARES_REC_TYPE_CNAME) { 99 struct ares_addrinfo_cname *cname; 100 101 got_cname = ARES_TRUE; 102 /* replace hostname with data from cname 103 * SA: Seems wrong as it introduces order dependency. */ 104 hostname = ares_dns_rr_get_str(rr, ARES_RR_CNAME_CNAME); 105 106 cname = ares_append_addrinfo_cname(&cnames); 107 if (cname == NULL) { 108 status = ARES_ENOMEM; /* LCOV_EXCL_LINE: OutOfMemory */ 109 goto done; /* LCOV_EXCL_LINE: OutOfMemory */ 110 } 111 cname->ttl = (int)ares_dns_rr_get_ttl(rr); 112 cname->alias = ares_strdup(ares_dns_rr_get_name(rr)); 113 if (cname->alias == NULL) { 114 status = ARES_ENOMEM; /* LCOV_EXCL_LINE: OutOfMemory */ 115 goto done; /* LCOV_EXCL_LINE: OutOfMemory */ 116 } 117 cname->name = ares_strdup(hostname); 118 if (cname->name == NULL) { 119 status = ARES_ENOMEM; /* LCOV_EXCL_LINE: OutOfMemory */ 120 goto done; /* LCOV_EXCL_LINE: OutOfMemory */ 121 } 122 } else if (rtype == ARES_REC_TYPE_A) { 123 got_a = ARES_TRUE; 124 status = 125 ares_append_ai_node(AF_INET, port, ares_dns_rr_get_ttl(rr), 126 ares_dns_rr_get_addr(rr, ARES_RR_A_ADDR), &nodes); 127 if (status != ARES_SUCCESS) { 128 goto done; /* LCOV_EXCL_LINE: OutOfMemory */ 129 } 130 } else if (rtype == ARES_REC_TYPE_AAAA) { 131 got_aaaa = ARES_TRUE; 132 status = ares_append_ai_node(AF_INET6, port, ares_dns_rr_get_ttl(rr), 133 ares_dns_rr_get_addr6(rr, ARES_RR_AAAA_ADDR), 134 &nodes); 135 if (status != ARES_SUCCESS) { 136 goto done; /* LCOV_EXCL_LINE: OutOfMemory */ 137 } 138 } else { 139 continue; 140 } 141 } 142 143 if (!got_a && !got_aaaa && 144 (!got_cname || (got_cname && cname_only_is_enodata))) { 145 status = ARES_ENODATA; 146 goto done; 147 } 148 149 /* save the hostname as ai->name */ 150 if (ai->name == NULL || !ares_strcaseeq(ai->name, hostname)) { 151 ares_free(ai->name); 152 ai->name = ares_strdup(hostname); 153 if (ai->name == NULL) { 154 status = ARES_ENOMEM; /* LCOV_EXCL_LINE: OutOfMemory */ 155 goto done; /* LCOV_EXCL_LINE: OutOfMemory */ 156 } 157 } 158 159 if (got_a || got_aaaa) { 160 ares_addrinfo_cat_nodes(&ai->nodes, nodes); 161 nodes = NULL; 162 } 163 164 if (got_cname) { 165 ares_addrinfo_cat_cnames(&ai->cnames, cnames); 166 cnames = NULL; 167 } 168 169 done: 170 ares_freeaddrinfo_cnames(cnames); 171 ares_freeaddrinfo_nodes(nodes); 172 173 /* compatibility */ 174 if (status == ARES_EBADNAME) { 175 status = ARES_EBADRESP; 176 } 177 178 return status; 179 }