Simon Cooksey / mbed-os

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features/netsocket/nsapi_dns.cpp@0:fb7af294d5d9, 2016-11-17 (annotated)

Committer:
Simon Cooksey
Date:
Thu Nov 17 16:43:53 2016 +0000
Revision:
0:fb7af294d5d9
Initial commit

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Simon Cooksey 0:fb7af294d5d9 1 /* nsapi_dns.cpp
Simon Cooksey 0:fb7af294d5d9 2 * Original work Copyright (c) 2013 Henry Leinen (henry[dot]leinen [at] online [dot] de)
Simon Cooksey 0:fb7af294d5d9 3 * Modified work Copyright (c) 2015 ARM Limited
Simon Cooksey 0:fb7af294d5d9 4 *
Simon Cooksey 0:fb7af294d5d9 5 * Licensed under the Apache License, Version 2.0 (the "License");
Simon Cooksey 0:fb7af294d5d9 6 * you may not use this file except in compliance with the License.
Simon Cooksey 0:fb7af294d5d9 7 * You may obtain a copy of the License at
Simon Cooksey 0:fb7af294d5d9 8 *
Simon Cooksey 0:fb7af294d5d9 9 * http://www.apache.org/licenses/LICENSE-2.0
Simon Cooksey 0:fb7af294d5d9 10 *
Simon Cooksey 0:fb7af294d5d9 11 * Unless required by applicable law or agreed to in writing, software
Simon Cooksey 0:fb7af294d5d9 12 * distributed under the License is distributed on an "AS IS" BASIS,
Simon Cooksey 0:fb7af294d5d9 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
Simon Cooksey 0:fb7af294d5d9 14 * See the License for the specific language governing permissions and
Simon Cooksey 0:fb7af294d5d9 15 * limitations under the License.
Simon Cooksey 0:fb7af294d5d9 16 */
Simon Cooksey 0:fb7af294d5d9 17 #include "nsapi_dns.h"
Simon Cooksey 0:fb7af294d5d9 18 #include "netsocket/UDPSocket.h"
Simon Cooksey 0:fb7af294d5d9 19 #include <string.h>
Simon Cooksey 0:fb7af294d5d9 20 #include <stdlib.h>
Simon Cooksey 0:fb7af294d5d9 21 #include <stdio.h>
Simon Cooksey 0:fb7af294d5d9 22
Simon Cooksey 0:fb7af294d5d9 23 #define CLASS_IN 1
Simon Cooksey 0:fb7af294d5d9 24
Simon Cooksey 0:fb7af294d5d9 25 #define RR_A 1
Simon Cooksey 0:fb7af294d5d9 26 #define RR_AAAA 28
Simon Cooksey 0:fb7af294d5d9 27
Simon Cooksey 0:fb7af294d5d9 28 // DNS options
Simon Cooksey 0:fb7af294d5d9 29 #define DNS_BUFFER_SIZE 512
Simon Cooksey 0:fb7af294d5d9 30 #define DNS_TIMEOUT 5000
Simon Cooksey 0:fb7af294d5d9 31 #define DNS_SERVERS_SIZE 5
Simon Cooksey 0:fb7af294d5d9 32
Simon Cooksey 0:fb7af294d5d9 33 nsapi_addr_t dns_servers[DNS_SERVERS_SIZE] = {
Simon Cooksey 0:fb7af294d5d9 34 {NSAPI_IPv4, {8, 8, 8, 8}},
Simon Cooksey 0:fb7af294d5d9 35 {NSAPI_IPv4, {209, 244, 0, 3}},
Simon Cooksey 0:fb7af294d5d9 36 {NSAPI_IPv4, {84, 200, 69, 80}},
Simon Cooksey 0:fb7af294d5d9 37 {NSAPI_IPv4, {8, 26, 56, 26}},
Simon Cooksey 0:fb7af294d5d9 38 {NSAPI_IPv4, {208, 67, 222, 222}},
Simon Cooksey 0:fb7af294d5d9 39 };
Simon Cooksey 0:fb7af294d5d9 40
Simon Cooksey 0:fb7af294d5d9 41 // DNS server configuration
Simon Cooksey 0:fb7af294d5d9 42 extern "C" int nsapi_dns_add_server(nsapi_addr_t addr)
Simon Cooksey 0:fb7af294d5d9 43 {
Simon Cooksey 0:fb7af294d5d9 44 memmove(&dns_servers[1], &dns_servers[0],
Simon Cooksey 0:fb7af294d5d9 45 (DNS_SERVERS_SIZE-1)*sizeof(nsapi_addr_t));
Simon Cooksey 0:fb7af294d5d9 46
Simon Cooksey 0:fb7af294d5d9 47 dns_servers[0] = addr;
Simon Cooksey 0:fb7af294d5d9 48 return 0;
Simon Cooksey 0:fb7af294d5d9 49 }
Simon Cooksey 0:fb7af294d5d9 50
Simon Cooksey 0:fb7af294d5d9 51
Simon Cooksey 0:fb7af294d5d9 52 // DNS packet parsing
Simon Cooksey 0:fb7af294d5d9 53 static void dns_append_byte(uint8_t **p, uint8_t byte)
Simon Cooksey 0:fb7af294d5d9 54 {
Simon Cooksey 0:fb7af294d5d9 55 *(*p)++ = byte;
Simon Cooksey 0:fb7af294d5d9 56 }
Simon Cooksey 0:fb7af294d5d9 57
Simon Cooksey 0:fb7af294d5d9 58 static void dns_append_word(uint8_t **p, uint16_t word)
Simon Cooksey 0:fb7af294d5d9 59 {
Simon Cooksey 0:fb7af294d5d9 60
Simon Cooksey 0:fb7af294d5d9 61 dns_append_byte(p, 0xff & (word >> 8));
Simon Cooksey 0:fb7af294d5d9 62 dns_append_byte(p, 0xff & (word >> 0));
Simon Cooksey 0:fb7af294d5d9 63 }
Simon Cooksey 0:fb7af294d5d9 64
Simon Cooksey 0:fb7af294d5d9 65 static void dns_append_name(uint8_t **p, const char *name, uint8_t len)
Simon Cooksey 0:fb7af294d5d9 66 {
Simon Cooksey 0:fb7af294d5d9 67 dns_append_byte(p, len);
Simon Cooksey 0:fb7af294d5d9 68 memcpy(*p, name, len);
Simon Cooksey 0:fb7af294d5d9 69 *p += len;
Simon Cooksey 0:fb7af294d5d9 70 }
Simon Cooksey 0:fb7af294d5d9 71
Simon Cooksey 0:fb7af294d5d9 72 static uint8_t dns_scan_byte(const uint8_t **p)
Simon Cooksey 0:fb7af294d5d9 73 {
Simon Cooksey 0:fb7af294d5d9 74 return *(*p)++;
Simon Cooksey 0:fb7af294d5d9 75 }
Simon Cooksey 0:fb7af294d5d9 76
Simon Cooksey 0:fb7af294d5d9 77 static uint16_t dns_scan_word(const uint8_t **p)
Simon Cooksey 0:fb7af294d5d9 78 {
Simon Cooksey 0:fb7af294d5d9 79 uint16_t a = dns_scan_byte(p);
Simon Cooksey 0:fb7af294d5d9 80 uint16_t b = dns_scan_byte(p);
Simon Cooksey 0:fb7af294d5d9 81 return (a << 8) | b;
Simon Cooksey 0:fb7af294d5d9 82 }
Simon Cooksey 0:fb7af294d5d9 83
Simon Cooksey 0:fb7af294d5d9 84
Simon Cooksey 0:fb7af294d5d9 85 static void dns_append_question(uint8_t **p, const char *host, nsapi_version_t version)
Simon Cooksey 0:fb7af294d5d9 86 {
Simon Cooksey 0:fb7af294d5d9 87 // fill the header
Simon Cooksey 0:fb7af294d5d9 88 dns_append_word(p, 1); // id = 1
Simon Cooksey 0:fb7af294d5d9 89 dns_append_word(p, 0x0100); // flags = recursion required
Simon Cooksey 0:fb7af294d5d9 90 dns_append_word(p, 1); // qdcount = 1
Simon Cooksey 0:fb7af294d5d9 91 dns_append_word(p, 0); // ancount = 0
Simon Cooksey 0:fb7af294d5d9 92 dns_append_word(p, 0); // nscount = 0
Simon Cooksey 0:fb7af294d5d9 93 dns_append_word(p, 0); // arcount = 0
Simon Cooksey 0:fb7af294d5d9 94
Simon Cooksey 0:fb7af294d5d9 95 // fill out the question names
Simon Cooksey 0:fb7af294d5d9 96 while (host[0]) {
Simon Cooksey 0:fb7af294d5d9 97 size_t label_len = strcspn(host, ".");
Simon Cooksey 0:fb7af294d5d9 98 dns_append_name(p, host, label_len);
Simon Cooksey 0:fb7af294d5d9 99 host += label_len + (host[label_len] == '.');
Simon Cooksey 0:fb7af294d5d9 100 }
Simon Cooksey 0:fb7af294d5d9 101
Simon Cooksey 0:fb7af294d5d9 102 dns_append_byte(p, 0);
Simon Cooksey 0:fb7af294d5d9 103
Simon Cooksey 0:fb7af294d5d9 104 // fill out question footer
Simon Cooksey 0:fb7af294d5d9 105 if (version != NSAPI_IPv6) {
Simon Cooksey 0:fb7af294d5d9 106 dns_append_word(p, RR_A); // qtype = ipv4
Simon Cooksey 0:fb7af294d5d9 107 } else {
Simon Cooksey 0:fb7af294d5d9 108 dns_append_word(p, RR_AAAA); // qtype = ipv6
Simon Cooksey 0:fb7af294d5d9 109 }
Simon Cooksey 0:fb7af294d5d9 110 dns_append_word(p, CLASS_IN);
Simon Cooksey 0:fb7af294d5d9 111 }
Simon Cooksey 0:fb7af294d5d9 112
Simon Cooksey 0:fb7af294d5d9 113 static int dns_scan_response(const uint8_t **p, nsapi_addr_t *addr, unsigned addr_count)
Simon Cooksey 0:fb7af294d5d9 114 {
Simon Cooksey 0:fb7af294d5d9 115 // scan header
Simon Cooksey 0:fb7af294d5d9 116 uint16_t id = dns_scan_word(p);
Simon Cooksey 0:fb7af294d5d9 117 uint16_t flags = dns_scan_word(p);
Simon Cooksey 0:fb7af294d5d9 118 bool qr = 0x1 & (flags >> 15);
Simon Cooksey 0:fb7af294d5d9 119 uint8_t opcode = 0xf & (flags >> 11);
Simon Cooksey 0:fb7af294d5d9 120 uint8_t rcode = 0xf & (flags >> 0);
Simon Cooksey 0:fb7af294d5d9 121
Simon Cooksey 0:fb7af294d5d9 122 uint16_t qdcount = dns_scan_word(p); // qdcount
Simon Cooksey 0:fb7af294d5d9 123 uint16_t ancount = dns_scan_word(p); // ancount
Simon Cooksey 0:fb7af294d5d9 124 dns_scan_word(p); // nscount
Simon Cooksey 0:fb7af294d5d9 125 dns_scan_word(p); // arcount
Simon Cooksey 0:fb7af294d5d9 126
Simon Cooksey 0:fb7af294d5d9 127 // verify header is response to query
Simon Cooksey 0:fb7af294d5d9 128 if (!(id == 1 && qr && opcode == 0 && rcode == 0)) {
Simon Cooksey 0:fb7af294d5d9 129 return 0;
Simon Cooksey 0:fb7af294d5d9 130 }
Simon Cooksey 0:fb7af294d5d9 131
Simon Cooksey 0:fb7af294d5d9 132 // skip questions
Simon Cooksey 0:fb7af294d5d9 133 for (int i = 0; i < qdcount; i++) {
Simon Cooksey 0:fb7af294d5d9 134 while (true) {
Simon Cooksey 0:fb7af294d5d9 135 uint8_t len = dns_scan_byte(p);
Simon Cooksey 0:fb7af294d5d9 136 if (len == 0) {
Simon Cooksey 0:fb7af294d5d9 137 break;
Simon Cooksey 0:fb7af294d5d9 138 }
Simon Cooksey 0:fb7af294d5d9 139
Simon Cooksey 0:fb7af294d5d9 140 *p += len;
Simon Cooksey 0:fb7af294d5d9 141 }
Simon Cooksey 0:fb7af294d5d9 142
Simon Cooksey 0:fb7af294d5d9 143 dns_scan_word(p); // qtype
Simon Cooksey 0:fb7af294d5d9 144 dns_scan_word(p); // qclass
Simon Cooksey 0:fb7af294d5d9 145 }
Simon Cooksey 0:fb7af294d5d9 146
Simon Cooksey 0:fb7af294d5d9 147 // scan each response
Simon Cooksey 0:fb7af294d5d9 148 unsigned count = 0;
Simon Cooksey 0:fb7af294d5d9 149
Simon Cooksey 0:fb7af294d5d9 150 for (int i = 0; i < ancount && count < addr_count; i++) {
Simon Cooksey 0:fb7af294d5d9 151 while (true) {
Simon Cooksey 0:fb7af294d5d9 152 uint8_t len = dns_scan_byte(p);
Simon Cooksey 0:fb7af294d5d9 153 if (len == 0) {
Simon Cooksey 0:fb7af294d5d9 154 break;
Simon Cooksey 0:fb7af294d5d9 155 } else if (len & 0xc0) { // this is link
Simon Cooksey 0:fb7af294d5d9 156 dns_scan_byte(p);
Simon Cooksey 0:fb7af294d5d9 157 break;
Simon Cooksey 0:fb7af294d5d9 158 }
Simon Cooksey 0:fb7af294d5d9 159
Simon Cooksey 0:fb7af294d5d9 160 *p += len;
Simon Cooksey 0:fb7af294d5d9 161 }
Simon Cooksey 0:fb7af294d5d9 162
Simon Cooksey 0:fb7af294d5d9 163 uint16_t rtype = dns_scan_word(p); // rtype
Simon Cooksey 0:fb7af294d5d9 164 uint16_t rclass = dns_scan_word(p); // rclass
Simon Cooksey 0:fb7af294d5d9 165 *p += 4; // ttl
Simon Cooksey 0:fb7af294d5d9 166 uint16_t rdlength = dns_scan_word(p); // rdlength
Simon Cooksey 0:fb7af294d5d9 167
Simon Cooksey 0:fb7af294d5d9 168 if (rtype == RR_A && rclass == CLASS_IN && rdlength == NSAPI_IPv4_BYTES) {
Simon Cooksey 0:fb7af294d5d9 169 // accept A record
Simon Cooksey 0:fb7af294d5d9 170 addr->version = NSAPI_IPv4;
Simon Cooksey 0:fb7af294d5d9 171 for (int i = 0; i < NSAPI_IPv4_BYTES; i++) {
Simon Cooksey 0:fb7af294d5d9 172 addr->bytes[i] = dns_scan_byte(p);
Simon Cooksey 0:fb7af294d5d9 173 }
Simon Cooksey 0:fb7af294d5d9 174
Simon Cooksey 0:fb7af294d5d9 175 addr += 1;
Simon Cooksey 0:fb7af294d5d9 176 count += 1;
Simon Cooksey 0:fb7af294d5d9 177 } else if (rtype == RR_AAAA && rclass == CLASS_IN && rdlength == NSAPI_IPv6_BYTES) {
Simon Cooksey 0:fb7af294d5d9 178 // accept AAAA record
Simon Cooksey 0:fb7af294d5d9 179 addr->version = NSAPI_IPv6;
Simon Cooksey 0:fb7af294d5d9 180 for (int i = 0; i < NSAPI_IPv6_BYTES; i++) {
Simon Cooksey 0:fb7af294d5d9 181 addr->bytes[i] = dns_scan_byte(p);
Simon Cooksey 0:fb7af294d5d9 182 }
Simon Cooksey 0:fb7af294d5d9 183
Simon Cooksey 0:fb7af294d5d9 184 addr += 1;
Simon Cooksey 0:fb7af294d5d9 185 count += 1;
Simon Cooksey 0:fb7af294d5d9 186 } else {
Simon Cooksey 0:fb7af294d5d9 187 // skip unrecognized records
Simon Cooksey 0:fb7af294d5d9 188 *p += rdlength;
Simon Cooksey 0:fb7af294d5d9 189 }
Simon Cooksey 0:fb7af294d5d9 190 }
Simon Cooksey 0:fb7af294d5d9 191
Simon Cooksey 0:fb7af294d5d9 192 return count;
Simon Cooksey 0:fb7af294d5d9 193 }
Simon Cooksey 0:fb7af294d5d9 194
Simon Cooksey 0:fb7af294d5d9 195 // core query function
Simon Cooksey 0:fb7af294d5d9 196 static int nsapi_dns_query_multiple(NetworkStack *stack, const char *host,
Simon Cooksey 0:fb7af294d5d9 197 nsapi_addr_t *addr, unsigned addr_count, nsapi_version_t version)
Simon Cooksey 0:fb7af294d5d9 198 {
Simon Cooksey 0:fb7af294d5d9 199 // check for valid host name
Simon Cooksey 0:fb7af294d5d9 200 int host_len = host ? strlen(host) : 0;
Simon Cooksey 0:fb7af294d5d9 201 if (host_len > 128 || host_len == 0) {
Simon Cooksey 0:fb7af294d5d9 202 return NSAPI_ERROR_PARAMETER;
Simon Cooksey 0:fb7af294d5d9 203 }
Simon Cooksey 0:fb7af294d5d9 204
Simon Cooksey 0:fb7af294d5d9 205 // create a udp socket
Simon Cooksey 0:fb7af294d5d9 206 UDPSocket socket;
Simon Cooksey 0:fb7af294d5d9 207 int err = socket.open(stack);
Simon Cooksey 0:fb7af294d5d9 208 if (err) {
Simon Cooksey 0:fb7af294d5d9 209 return err;
Simon Cooksey 0:fb7af294d5d9 210 }
Simon Cooksey 0:fb7af294d5d9 211
Simon Cooksey 0:fb7af294d5d9 212 socket.set_timeout(DNS_TIMEOUT);
Simon Cooksey 0:fb7af294d5d9 213
Simon Cooksey 0:fb7af294d5d9 214 // create network packet
Simon Cooksey 0:fb7af294d5d9 215 uint8_t *packet = (uint8_t *)malloc(DNS_BUFFER_SIZE);
Simon Cooksey 0:fb7af294d5d9 216 if (!packet) {
Simon Cooksey 0:fb7af294d5d9 217 return NSAPI_ERROR_NO_MEMORY;
Simon Cooksey 0:fb7af294d5d9 218 }
Simon Cooksey 0:fb7af294d5d9 219
Simon Cooksey 0:fb7af294d5d9 220 int result = NSAPI_ERROR_DNS_FAILURE;
Simon Cooksey 0:fb7af294d5d9 221
Simon Cooksey 0:fb7af294d5d9 222 // check against each dns server
Simon Cooksey 0:fb7af294d5d9 223 for (unsigned i = 0; i < DNS_SERVERS_SIZE; i++) {
Simon Cooksey 0:fb7af294d5d9 224 // send the question
Simon Cooksey 0:fb7af294d5d9 225 uint8_t *question = packet;
Simon Cooksey 0:fb7af294d5d9 226 dns_append_question(&question, host, version);
Simon Cooksey 0:fb7af294d5d9 227
Simon Cooksey 0:fb7af294d5d9 228 err = socket.sendto(SocketAddress(dns_servers[i], 53), packet, DNS_BUFFER_SIZE);
Simon Cooksey 0:fb7af294d5d9 229 if (err == NSAPI_ERROR_WOULD_BLOCK) {
Simon Cooksey 0:fb7af294d5d9 230 continue;
Simon Cooksey 0:fb7af294d5d9 231 } else if (err < 0) {
Simon Cooksey 0:fb7af294d5d9 232 result = err;
Simon Cooksey 0:fb7af294d5d9 233 break;
Simon Cooksey 0:fb7af294d5d9 234 }
Simon Cooksey 0:fb7af294d5d9 235
Simon Cooksey 0:fb7af294d5d9 236 // recv the response
Simon Cooksey 0:fb7af294d5d9 237 err = socket.recvfrom(NULL, packet, DNS_BUFFER_SIZE);
Simon Cooksey 0:fb7af294d5d9 238 if (err == NSAPI_ERROR_WOULD_BLOCK) {
Simon Cooksey 0:fb7af294d5d9 239 continue;
Simon Cooksey 0:fb7af294d5d9 240 } else if (err < 0) {
Simon Cooksey 0:fb7af294d5d9 241 result = err;
Simon Cooksey 0:fb7af294d5d9 242 break;
Simon Cooksey 0:fb7af294d5d9 243 }
Simon Cooksey 0:fb7af294d5d9 244
Simon Cooksey 0:fb7af294d5d9 245 const uint8_t *response = packet;
Simon Cooksey 0:fb7af294d5d9 246 if (dns_scan_response(&response, addr, addr_count) > 0) {
Simon Cooksey 0:fb7af294d5d9 247 result = NSAPI_ERROR_OK;
Simon Cooksey 0:fb7af294d5d9 248 }
Simon Cooksey 0:fb7af294d5d9 249
Simon Cooksey 0:fb7af294d5d9 250 /* The DNS response is final, no need to check other servers */
Simon Cooksey 0:fb7af294d5d9 251 break;
Simon Cooksey 0:fb7af294d5d9 252 }
Simon Cooksey 0:fb7af294d5d9 253
Simon Cooksey 0:fb7af294d5d9 254 // clean up packet
Simon Cooksey 0:fb7af294d5d9 255 free(packet);
Simon Cooksey 0:fb7af294d5d9 256
Simon Cooksey 0:fb7af294d5d9 257 // clean up udp
Simon Cooksey 0:fb7af294d5d9 258 err = socket.close();
Simon Cooksey 0:fb7af294d5d9 259 if (err) {
Simon Cooksey 0:fb7af294d5d9 260 return err;
Simon Cooksey 0:fb7af294d5d9 261 }
Simon Cooksey 0:fb7af294d5d9 262
Simon Cooksey 0:fb7af294d5d9 263 // return result
Simon Cooksey 0:fb7af294d5d9 264 return result;
Simon Cooksey 0:fb7af294d5d9 265 }
Simon Cooksey 0:fb7af294d5d9 266
Simon Cooksey 0:fb7af294d5d9 267 // convenience functions for other forms of queries
Simon Cooksey 0:fb7af294d5d9 268 extern "C" int nsapi_dns_query_multiple(nsapi_stack_t *stack, const char *host,
Simon Cooksey 0:fb7af294d5d9 269 nsapi_addr_t *addr, unsigned addr_count, nsapi_version_t version)
Simon Cooksey 0:fb7af294d5d9 270 {
Simon Cooksey 0:fb7af294d5d9 271 NetworkStack *nstack = nsapi_create_stack(stack);
Simon Cooksey 0:fb7af294d5d9 272 return nsapi_dns_query_multiple(nstack, host, addr, addr_count, version);
Simon Cooksey 0:fb7af294d5d9 273 }
Simon Cooksey 0:fb7af294d5d9 274
Simon Cooksey 0:fb7af294d5d9 275 int nsapi_dns_query_multiple(NetworkStack *stack, const char *host,
Simon Cooksey 0:fb7af294d5d9 276 SocketAddress *addresses, unsigned addr_count, nsapi_version_t version)
Simon Cooksey 0:fb7af294d5d9 277 {
Simon Cooksey 0:fb7af294d5d9 278 nsapi_addr_t *addrs = new nsapi_addr_t[addr_count];
Simon Cooksey 0:fb7af294d5d9 279 int result = nsapi_dns_query_multiple(stack, host, addrs, addr_count, version);
Simon Cooksey 0:fb7af294d5d9 280
Simon Cooksey 0:fb7af294d5d9 281 if (result > 0) {
Simon Cooksey 0:fb7af294d5d9 282 for (int i = 0; i < result; i++) {
Simon Cooksey 0:fb7af294d5d9 283 addresses[i].set_addr(addrs[i]);
Simon Cooksey 0:fb7af294d5d9 284 }
Simon Cooksey 0:fb7af294d5d9 285 }
Simon Cooksey 0:fb7af294d5d9 286
Simon Cooksey 0:fb7af294d5d9 287 delete[] addrs;
Simon Cooksey 0:fb7af294d5d9 288 return result;
Simon Cooksey 0:fb7af294d5d9 289 }
Simon Cooksey 0:fb7af294d5d9 290
Simon Cooksey 0:fb7af294d5d9 291 extern "C" int nsapi_dns_query(nsapi_stack_t *stack, const char *host,
Simon Cooksey 0:fb7af294d5d9 292 nsapi_addr_t *addr, nsapi_version_t version)
Simon Cooksey 0:fb7af294d5d9 293 {
Simon Cooksey 0:fb7af294d5d9 294 NetworkStack *nstack = nsapi_create_stack(stack);
Simon Cooksey 0:fb7af294d5d9 295 int result = nsapi_dns_query_multiple(nstack, host, addr, 1, version);
Simon Cooksey 0:fb7af294d5d9 296 return (result > 0) ? 0 : result;
Simon Cooksey 0:fb7af294d5d9 297 }
Simon Cooksey 0:fb7af294d5d9 298
Simon Cooksey 0:fb7af294d5d9 299 int nsapi_dns_query(NetworkStack *stack, const char *host,
Simon Cooksey 0:fb7af294d5d9 300 SocketAddress *address, nsapi_version_t version)
Simon Cooksey 0:fb7af294d5d9 301 {
Simon Cooksey 0:fb7af294d5d9 302 nsapi_addr_t addr;
Simon Cooksey 0:fb7af294d5d9 303 int result = nsapi_dns_query_multiple(stack, host, &addr, 1, version);
Simon Cooksey 0:fb7af294d5d9 304 address->set_addr(addr);
Simon Cooksey 0:fb7af294d5d9 305 return (result > 0) ? 0 : result;
Simon Cooksey 0:fb7af294d5d9 306 }