Marco Zecchini / Mbed OS Example_RTOS

Rtos API example

mbed-os/features/netsocket/nsapi_dns.cpp@0:9fca2b23d0ba, 2019-02-23 (annotated)

Committer:
marcozecchini
Date:
Sat Feb 23 12:13:36 2019 +0000
Revision:
0:9fca2b23d0ba
final commit

Who changed what in which revision?

UserRevisionLine numberNew contents of line
marcozecchini 0:9fca2b23d0ba 1 /* nsapi_dns.cpp
marcozecchini 0:9fca2b23d0ba 2 * Original work Copyright (c) 2013 Henry Leinen (henry[dot]leinen [at] online [dot] de)
marcozecchini 0:9fca2b23d0ba 3 * Modified work Copyright (c) 2015 ARM Limited
marcozecchini 0:9fca2b23d0ba 4 *
marcozecchini 0:9fca2b23d0ba 5 * Licensed under the Apache License, Version 2.0 (the "License");
marcozecchini 0:9fca2b23d0ba 6 * you may not use this file except in compliance with the License.
marcozecchini 0:9fca2b23d0ba 7 * You may obtain a copy of the License at
marcozecchini 0:9fca2b23d0ba 8 *
marcozecchini 0:9fca2b23d0ba 9 * http://www.apache.org/licenses/LICENSE-2.0
marcozecchini 0:9fca2b23d0ba 10 *
marcozecchini 0:9fca2b23d0ba 11 * Unless required by applicable law or agreed to in writing, software
marcozecchini 0:9fca2b23d0ba 12 * distributed under the License is distributed on an "AS IS" BASIS,
marcozecchini 0:9fca2b23d0ba 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
marcozecchini 0:9fca2b23d0ba 14 * See the License for the specific language governing permissions and
marcozecchini 0:9fca2b23d0ba 15 * limitations under the License.
marcozecchini 0:9fca2b23d0ba 16 */
marcozecchini 0:9fca2b23d0ba 17 #include "nsapi_dns.h"
marcozecchini 0:9fca2b23d0ba 18 #include "netsocket/UDPSocket.h"
marcozecchini 0:9fca2b23d0ba 19 #include <string.h>
marcozecchini 0:9fca2b23d0ba 20 #include <stdlib.h>
marcozecchini 0:9fca2b23d0ba 21 #include <stdio.h>
marcozecchini 0:9fca2b23d0ba 22
marcozecchini 0:9fca2b23d0ba 23 #define CLASS_IN 1
marcozecchini 0:9fca2b23d0ba 24
marcozecchini 0:9fca2b23d0ba 25 #define RR_A 1
marcozecchini 0:9fca2b23d0ba 26 #define RR_AAAA 28
marcozecchini 0:9fca2b23d0ba 27
marcozecchini 0:9fca2b23d0ba 28 // DNS options
marcozecchini 0:9fca2b23d0ba 29 #define DNS_BUFFER_SIZE 512
marcozecchini 0:9fca2b23d0ba 30 #define DNS_TIMEOUT 5000
marcozecchini 0:9fca2b23d0ba 31 #define DNS_SERVERS_SIZE 5
marcozecchini 0:9fca2b23d0ba 32
marcozecchini 0:9fca2b23d0ba 33 nsapi_addr_t dns_servers[DNS_SERVERS_SIZE] = {
marcozecchini 0:9fca2b23d0ba 34 {NSAPI_IPv4, {8, 8, 8, 8}}, // Google
marcozecchini 0:9fca2b23d0ba 35 {NSAPI_IPv4, {209, 244, 0, 3}}, // Level 3
marcozecchini 0:9fca2b23d0ba 36 {NSAPI_IPv4, {84, 200, 69, 80}}, // DNS.WATCH
marcozecchini 0:9fca2b23d0ba 37 {NSAPI_IPv6, {0x20,0x01, 0x48,0x60, 0x48,0x60, 0,0, // Google
marcozecchini 0:9fca2b23d0ba 38 0,0, 0,0, 0,0, 0x88,0x88}},
marcozecchini 0:9fca2b23d0ba 39 {NSAPI_IPv6, {0x20,0x01, 0x16,0x08, 0,0x10, 0,0x25, // DNS.WATCH
marcozecchini 0:9fca2b23d0ba 40 0,0, 0,0, 0x1c,0x04, 0xb1,0x2f}},
marcozecchini 0:9fca2b23d0ba 41 };
marcozecchini 0:9fca2b23d0ba 42
marcozecchini 0:9fca2b23d0ba 43 // DNS server configuration
marcozecchini 0:9fca2b23d0ba 44 extern "C" nsapi_error_t nsapi_dns_add_server(nsapi_addr_t addr)
marcozecchini 0:9fca2b23d0ba 45 {
marcozecchini 0:9fca2b23d0ba 46 memmove(&dns_servers[1], &dns_servers[0],
marcozecchini 0:9fca2b23d0ba 47 (DNS_SERVERS_SIZE-1)*sizeof(nsapi_addr_t));
marcozecchini 0:9fca2b23d0ba 48
marcozecchini 0:9fca2b23d0ba 49 dns_servers[0] = addr;
marcozecchini 0:9fca2b23d0ba 50 return NSAPI_ERROR_OK;
marcozecchini 0:9fca2b23d0ba 51 }
marcozecchini 0:9fca2b23d0ba 52
marcozecchini 0:9fca2b23d0ba 53
marcozecchini 0:9fca2b23d0ba 54 // DNS packet parsing
marcozecchini 0:9fca2b23d0ba 55 static void dns_append_byte(uint8_t **p, uint8_t byte)
marcozecchini 0:9fca2b23d0ba 56 {
marcozecchini 0:9fca2b23d0ba 57 *(*p)++ = byte;
marcozecchini 0:9fca2b23d0ba 58 }
marcozecchini 0:9fca2b23d0ba 59
marcozecchini 0:9fca2b23d0ba 60 static void dns_append_word(uint8_t **p, uint16_t word)
marcozecchini 0:9fca2b23d0ba 61 {
marcozecchini 0:9fca2b23d0ba 62
marcozecchini 0:9fca2b23d0ba 63 dns_append_byte(p, 0xff & (word >> 8));
marcozecchini 0:9fca2b23d0ba 64 dns_append_byte(p, 0xff & (word >> 0));
marcozecchini 0:9fca2b23d0ba 65 }
marcozecchini 0:9fca2b23d0ba 66
marcozecchini 0:9fca2b23d0ba 67 static void dns_append_name(uint8_t **p, const char *name, uint8_t len)
marcozecchini 0:9fca2b23d0ba 68 {
marcozecchini 0:9fca2b23d0ba 69 dns_append_byte(p, len);
marcozecchini 0:9fca2b23d0ba 70 memcpy(*p, name, len);
marcozecchini 0:9fca2b23d0ba 71 *p += len;
marcozecchini 0:9fca2b23d0ba 72 }
marcozecchini 0:9fca2b23d0ba 73
marcozecchini 0:9fca2b23d0ba 74 static uint8_t dns_scan_byte(const uint8_t **p)
marcozecchini 0:9fca2b23d0ba 75 {
marcozecchini 0:9fca2b23d0ba 76 return *(*p)++;
marcozecchini 0:9fca2b23d0ba 77 }
marcozecchini 0:9fca2b23d0ba 78
marcozecchini 0:9fca2b23d0ba 79 static uint16_t dns_scan_word(const uint8_t **p)
marcozecchini 0:9fca2b23d0ba 80 {
marcozecchini 0:9fca2b23d0ba 81 uint16_t a = dns_scan_byte(p);
marcozecchini 0:9fca2b23d0ba 82 uint16_t b = dns_scan_byte(p);
marcozecchini 0:9fca2b23d0ba 83 return (a << 8) | b;
marcozecchini 0:9fca2b23d0ba 84 }
marcozecchini 0:9fca2b23d0ba 85
marcozecchini 0:9fca2b23d0ba 86
marcozecchini 0:9fca2b23d0ba 87 static void dns_append_question(uint8_t **p, const char *host, nsapi_version_t version)
marcozecchini 0:9fca2b23d0ba 88 {
marcozecchini 0:9fca2b23d0ba 89 // fill the header
marcozecchini 0:9fca2b23d0ba 90 dns_append_word(p, 1); // id = 1
marcozecchini 0:9fca2b23d0ba 91 dns_append_word(p, 0x0100); // flags = recursion required
marcozecchini 0:9fca2b23d0ba 92 dns_append_word(p, 1); // qdcount = 1
marcozecchini 0:9fca2b23d0ba 93 dns_append_word(p, 0); // ancount = 0
marcozecchini 0:9fca2b23d0ba 94 dns_append_word(p, 0); // nscount = 0
marcozecchini 0:9fca2b23d0ba 95 dns_append_word(p, 0); // arcount = 0
marcozecchini 0:9fca2b23d0ba 96
marcozecchini 0:9fca2b23d0ba 97 // fill out the question names
marcozecchini 0:9fca2b23d0ba 98 while (host[0]) {
marcozecchini 0:9fca2b23d0ba 99 size_t label_len = strcspn(host, ".");
marcozecchini 0:9fca2b23d0ba 100 dns_append_name(p, host, label_len);
marcozecchini 0:9fca2b23d0ba 101 host += label_len + (host[label_len] == '.');
marcozecchini 0:9fca2b23d0ba 102 }
marcozecchini 0:9fca2b23d0ba 103
marcozecchini 0:9fca2b23d0ba 104 dns_append_byte(p, 0);
marcozecchini 0:9fca2b23d0ba 105
marcozecchini 0:9fca2b23d0ba 106 // fill out question footer
marcozecchini 0:9fca2b23d0ba 107 if (version != NSAPI_IPv6) {
marcozecchini 0:9fca2b23d0ba 108 dns_append_word(p, RR_A); // qtype = ipv4
marcozecchini 0:9fca2b23d0ba 109 } else {
marcozecchini 0:9fca2b23d0ba 110 dns_append_word(p, RR_AAAA); // qtype = ipv6
marcozecchini 0:9fca2b23d0ba 111 }
marcozecchini 0:9fca2b23d0ba 112 dns_append_word(p, CLASS_IN);
marcozecchini 0:9fca2b23d0ba 113 }
marcozecchini 0:9fca2b23d0ba 114
marcozecchini 0:9fca2b23d0ba 115 static int dns_scan_response(const uint8_t **p, nsapi_addr_t *addr, unsigned addr_count)
marcozecchini 0:9fca2b23d0ba 116 {
marcozecchini 0:9fca2b23d0ba 117 // scan header
marcozecchini 0:9fca2b23d0ba 118 uint16_t id = dns_scan_word(p);
marcozecchini 0:9fca2b23d0ba 119 uint16_t flags = dns_scan_word(p);
marcozecchini 0:9fca2b23d0ba 120 bool qr = 0x1 & (flags >> 15);
marcozecchini 0:9fca2b23d0ba 121 uint8_t opcode = 0xf & (flags >> 11);
marcozecchini 0:9fca2b23d0ba 122 uint8_t rcode = 0xf & (flags >> 0);
marcozecchini 0:9fca2b23d0ba 123
marcozecchini 0:9fca2b23d0ba 124 uint16_t qdcount = dns_scan_word(p); // qdcount
marcozecchini 0:9fca2b23d0ba 125 uint16_t ancount = dns_scan_word(p); // ancount
marcozecchini 0:9fca2b23d0ba 126 dns_scan_word(p); // nscount
marcozecchini 0:9fca2b23d0ba 127 dns_scan_word(p); // arcount
marcozecchini 0:9fca2b23d0ba 128
marcozecchini 0:9fca2b23d0ba 129 // verify header is response to query
marcozecchini 0:9fca2b23d0ba 130 if (!(id == 1 && qr && opcode == 0 && rcode == 0)) {
marcozecchini 0:9fca2b23d0ba 131 return 0;
marcozecchini 0:9fca2b23d0ba 132 }
marcozecchini 0:9fca2b23d0ba 133
marcozecchini 0:9fca2b23d0ba 134 // skip questions
marcozecchini 0:9fca2b23d0ba 135 for (int i = 0; i < qdcount; i++) {
marcozecchini 0:9fca2b23d0ba 136 while (true) {
marcozecchini 0:9fca2b23d0ba 137 uint8_t len = dns_scan_byte(p);
marcozecchini 0:9fca2b23d0ba 138 if (len == 0) {
marcozecchini 0:9fca2b23d0ba 139 break;
marcozecchini 0:9fca2b23d0ba 140 }
marcozecchini 0:9fca2b23d0ba 141
marcozecchini 0:9fca2b23d0ba 142 *p += len;
marcozecchini 0:9fca2b23d0ba 143 }
marcozecchini 0:9fca2b23d0ba 144
marcozecchini 0:9fca2b23d0ba 145 dns_scan_word(p); // qtype
marcozecchini 0:9fca2b23d0ba 146 dns_scan_word(p); // qclass
marcozecchini 0:9fca2b23d0ba 147 }
marcozecchini 0:9fca2b23d0ba 148
marcozecchini 0:9fca2b23d0ba 149 // scan each response
marcozecchini 0:9fca2b23d0ba 150 unsigned count = 0;
marcozecchini 0:9fca2b23d0ba 151
marcozecchini 0:9fca2b23d0ba 152 for (int i = 0; i < ancount && count < addr_count; i++) {
marcozecchini 0:9fca2b23d0ba 153 while (true) {
marcozecchini 0:9fca2b23d0ba 154 uint8_t len = dns_scan_byte(p);
marcozecchini 0:9fca2b23d0ba 155 if (len == 0) {
marcozecchini 0:9fca2b23d0ba 156 break;
marcozecchini 0:9fca2b23d0ba 157 } else if (len & 0xc0) { // this is link
marcozecchini 0:9fca2b23d0ba 158 dns_scan_byte(p);
marcozecchini 0:9fca2b23d0ba 159 break;
marcozecchini 0:9fca2b23d0ba 160 }
marcozecchini 0:9fca2b23d0ba 161
marcozecchini 0:9fca2b23d0ba 162 *p += len;
marcozecchini 0:9fca2b23d0ba 163 }
marcozecchini 0:9fca2b23d0ba 164
marcozecchini 0:9fca2b23d0ba 165 uint16_t rtype = dns_scan_word(p); // rtype
marcozecchini 0:9fca2b23d0ba 166 uint16_t rclass = dns_scan_word(p); // rclass
marcozecchini 0:9fca2b23d0ba 167 *p += 4; // ttl
marcozecchini 0:9fca2b23d0ba 168 uint16_t rdlength = dns_scan_word(p); // rdlength
marcozecchini 0:9fca2b23d0ba 169
marcozecchini 0:9fca2b23d0ba 170 if (rtype == RR_A && rclass == CLASS_IN && rdlength == NSAPI_IPv4_BYTES) {
marcozecchini 0:9fca2b23d0ba 171 // accept A record
marcozecchini 0:9fca2b23d0ba 172 addr->version = NSAPI_IPv4;
marcozecchini 0:9fca2b23d0ba 173 for (int i = 0; i < NSAPI_IPv4_BYTES; i++) {
marcozecchini 0:9fca2b23d0ba 174 addr->bytes[i] = dns_scan_byte(p);
marcozecchini 0:9fca2b23d0ba 175 }
marcozecchini 0:9fca2b23d0ba 176
marcozecchini 0:9fca2b23d0ba 177 addr += 1;
marcozecchini 0:9fca2b23d0ba 178 count += 1;
marcozecchini 0:9fca2b23d0ba 179 } else if (rtype == RR_AAAA && rclass == CLASS_IN && rdlength == NSAPI_IPv6_BYTES) {
marcozecchini 0:9fca2b23d0ba 180 // accept AAAA record
marcozecchini 0:9fca2b23d0ba 181 addr->version = NSAPI_IPv6;
marcozecchini 0:9fca2b23d0ba 182 for (int i = 0; i < NSAPI_IPv6_BYTES; i++) {
marcozecchini 0:9fca2b23d0ba 183 addr->bytes[i] = dns_scan_byte(p);
marcozecchini 0:9fca2b23d0ba 184 }
marcozecchini 0:9fca2b23d0ba 185
marcozecchini 0:9fca2b23d0ba 186 addr += 1;
marcozecchini 0:9fca2b23d0ba 187 count += 1;
marcozecchini 0:9fca2b23d0ba 188 } else {
marcozecchini 0:9fca2b23d0ba 189 // skip unrecognized records
marcozecchini 0:9fca2b23d0ba 190 *p += rdlength;
marcozecchini 0:9fca2b23d0ba 191 }
marcozecchini 0:9fca2b23d0ba 192 }
marcozecchini 0:9fca2b23d0ba 193
marcozecchini 0:9fca2b23d0ba 194 return count;
marcozecchini 0:9fca2b23d0ba 195 }
marcozecchini 0:9fca2b23d0ba 196
marcozecchini 0:9fca2b23d0ba 197 // core query function
marcozecchini 0:9fca2b23d0ba 198 static nsapi_size_or_error_t nsapi_dns_query_multiple(NetworkStack *stack, const char *host,
marcozecchini 0:9fca2b23d0ba 199 nsapi_addr_t *addr, unsigned addr_count, nsapi_version_t version)
marcozecchini 0:9fca2b23d0ba 200 {
marcozecchini 0:9fca2b23d0ba 201 // check for valid host name
marcozecchini 0:9fca2b23d0ba 202 int host_len = host ? strlen(host) : 0;
marcozecchini 0:9fca2b23d0ba 203 if (host_len > 128 || host_len == 0) {
marcozecchini 0:9fca2b23d0ba 204 return NSAPI_ERROR_PARAMETER;
marcozecchini 0:9fca2b23d0ba 205 }
marcozecchini 0:9fca2b23d0ba 206
marcozecchini 0:9fca2b23d0ba 207 // create a udp socket
marcozecchini 0:9fca2b23d0ba 208 UDPSocket socket;
marcozecchini 0:9fca2b23d0ba 209 int err = socket.open(stack);
marcozecchini 0:9fca2b23d0ba 210 if (err) {
marcozecchini 0:9fca2b23d0ba 211 return err;
marcozecchini 0:9fca2b23d0ba 212 }
marcozecchini 0:9fca2b23d0ba 213
marcozecchini 0:9fca2b23d0ba 214 socket.set_timeout(DNS_TIMEOUT);
marcozecchini 0:9fca2b23d0ba 215
marcozecchini 0:9fca2b23d0ba 216 // create network packet
marcozecchini 0:9fca2b23d0ba 217 uint8_t *packet = (uint8_t *)malloc(DNS_BUFFER_SIZE);
marcozecchini 0:9fca2b23d0ba 218 if (!packet) {
marcozecchini 0:9fca2b23d0ba 219 return NSAPI_ERROR_NO_MEMORY;
marcozecchini 0:9fca2b23d0ba 220 }
marcozecchini 0:9fca2b23d0ba 221
marcozecchini 0:9fca2b23d0ba 222 nsapi_size_or_error_t result = NSAPI_ERROR_DNS_FAILURE;
marcozecchini 0:9fca2b23d0ba 223
marcozecchini 0:9fca2b23d0ba 224 // check against each dns server
marcozecchini 0:9fca2b23d0ba 225 for (unsigned i = 0; i < DNS_SERVERS_SIZE; i++) {
marcozecchini 0:9fca2b23d0ba 226 // send the question
marcozecchini 0:9fca2b23d0ba 227 uint8_t *question = packet;
marcozecchini 0:9fca2b23d0ba 228 dns_append_question(&question, host, version);
marcozecchini 0:9fca2b23d0ba 229
marcozecchini 0:9fca2b23d0ba 230 err = socket.sendto(SocketAddress(dns_servers[i], 53), packet, question - packet);
marcozecchini 0:9fca2b23d0ba 231 // send may fail for various reasons, including wrong address type - move on
marcozecchini 0:9fca2b23d0ba 232 if (err < 0) {
marcozecchini 0:9fca2b23d0ba 233 continue;
marcozecchini 0:9fca2b23d0ba 234 }
marcozecchini 0:9fca2b23d0ba 235
marcozecchini 0:9fca2b23d0ba 236 // recv the response
marcozecchini 0:9fca2b23d0ba 237 err = socket.recvfrom(NULL, packet, DNS_BUFFER_SIZE);
marcozecchini 0:9fca2b23d0ba 238 if (err == NSAPI_ERROR_WOULD_BLOCK) {
marcozecchini 0:9fca2b23d0ba 239 continue;
marcozecchini 0:9fca2b23d0ba 240 } else if (err < 0) {
marcozecchini 0:9fca2b23d0ba 241 result = err;
marcozecchini 0:9fca2b23d0ba 242 break;
marcozecchini 0:9fca2b23d0ba 243 }
marcozecchini 0:9fca2b23d0ba 244
marcozecchini 0:9fca2b23d0ba 245 const uint8_t *response = packet;
marcozecchini 0:9fca2b23d0ba 246 if (dns_scan_response(&response, addr, addr_count) > 0) {
marcozecchini 0:9fca2b23d0ba 247 result = NSAPI_ERROR_OK;
marcozecchini 0:9fca2b23d0ba 248 }
marcozecchini 0:9fca2b23d0ba 249
marcozecchini 0:9fca2b23d0ba 250 /* The DNS response is final, no need to check other servers */
marcozecchini 0:9fca2b23d0ba 251 break;
marcozecchini 0:9fca2b23d0ba 252 }
marcozecchini 0:9fca2b23d0ba 253
marcozecchini 0:9fca2b23d0ba 254 // clean up packet
marcozecchini 0:9fca2b23d0ba 255 free(packet);
marcozecchini 0:9fca2b23d0ba 256
marcozecchini 0:9fca2b23d0ba 257 // clean up udp
marcozecchini 0:9fca2b23d0ba 258 err = socket.close();
marcozecchini 0:9fca2b23d0ba 259 if (err) {
marcozecchini 0:9fca2b23d0ba 260 return err;
marcozecchini 0:9fca2b23d0ba 261 }
marcozecchini 0:9fca2b23d0ba 262
marcozecchini 0:9fca2b23d0ba 263 // return result
marcozecchini 0:9fca2b23d0ba 264 return result;
marcozecchini 0:9fca2b23d0ba 265 }
marcozecchini 0:9fca2b23d0ba 266
marcozecchini 0:9fca2b23d0ba 267 // convenience functions for other forms of queries
marcozecchini 0:9fca2b23d0ba 268 extern "C" nsapi_size_or_error_t nsapi_dns_query_multiple(nsapi_stack_t *stack, const char *host,
marcozecchini 0:9fca2b23d0ba 269 nsapi_addr_t *addr, nsapi_size_t addr_count, nsapi_version_t version)
marcozecchini 0:9fca2b23d0ba 270 {
marcozecchini 0:9fca2b23d0ba 271 NetworkStack *nstack = nsapi_create_stack(stack);
marcozecchini 0:9fca2b23d0ba 272 return nsapi_dns_query_multiple(nstack, host, addr, addr_count, version);
marcozecchini 0:9fca2b23d0ba 273 }
marcozecchini 0:9fca2b23d0ba 274
marcozecchini 0:9fca2b23d0ba 275 nsapi_size_or_error_t nsapi_dns_query_multiple(NetworkStack *stack, const char *host,
marcozecchini 0:9fca2b23d0ba 276 SocketAddress *addresses, nsapi_size_t addr_count, nsapi_version_t version)
marcozecchini 0:9fca2b23d0ba 277 {
marcozecchini 0:9fca2b23d0ba 278 nsapi_addr_t *addrs = new nsapi_addr_t[addr_count];
marcozecchini 0:9fca2b23d0ba 279 nsapi_size_or_error_t result = nsapi_dns_query_multiple(stack, host, addrs, addr_count, version);
marcozecchini 0:9fca2b23d0ba 280
marcozecchini 0:9fca2b23d0ba 281 if (result > 0) {
marcozecchini 0:9fca2b23d0ba 282 for (int i = 0; i < result; i++) {
marcozecchini 0:9fca2b23d0ba 283 addresses[i].set_addr(addrs[i]);
marcozecchini 0:9fca2b23d0ba 284 }
marcozecchini 0:9fca2b23d0ba 285 }
marcozecchini 0:9fca2b23d0ba 286
marcozecchini 0:9fca2b23d0ba 287 delete[] addrs;
marcozecchini 0:9fca2b23d0ba 288 return result;
marcozecchini 0:9fca2b23d0ba 289 }
marcozecchini 0:9fca2b23d0ba 290
marcozecchini 0:9fca2b23d0ba 291 extern "C" nsapi_error_t nsapi_dns_query(nsapi_stack_t *stack, const char *host,
marcozecchini 0:9fca2b23d0ba 292 nsapi_addr_t *addr, nsapi_version_t version)
marcozecchini 0:9fca2b23d0ba 293 {
marcozecchini 0:9fca2b23d0ba 294 NetworkStack *nstack = nsapi_create_stack(stack);
marcozecchini 0:9fca2b23d0ba 295 nsapi_size_or_error_t result = nsapi_dns_query_multiple(nstack, host, addr, 1, version);
marcozecchini 0:9fca2b23d0ba 296 return (nsapi_error_t)((result > 0) ? 0 : result);
marcozecchini 0:9fca2b23d0ba 297 }
marcozecchini 0:9fca2b23d0ba 298
marcozecchini 0:9fca2b23d0ba 299 nsapi_error_t nsapi_dns_query(NetworkStack *stack, const char *host,
marcozecchini 0:9fca2b23d0ba 300 SocketAddress *address, nsapi_version_t version)
marcozecchini 0:9fca2b23d0ba 301 {
marcozecchini 0:9fca2b23d0ba 302 nsapi_addr_t addr;
marcozecchini 0:9fca2b23d0ba 303 nsapi_size_or_error_t result = nsapi_dns_query_multiple(stack, host, &addr, 1, version);
marcozecchini 0:9fca2b23d0ba 304 address->set_addr(addr);
marcozecchini 0:9fca2b23d0ba 305 return (nsapi_error_t)((result > 0) ? 0 : result);
marcozecchini 0:9fca2b23d0ba 306 }