DnsQuery for NetworkSocketAPI
Fork of DnsQuery by
DnsQuery.cpp@19:4c6f4b6036e6, 2016-08-30 (annotated)
- Committer:
- kaizen
- Date:
- Tue Aug 30 01:57:17 2016 +0000
- Revision:
- 19:4c6f4b6036e6
- Parent:
- 18:2cb1fffed50c
added some delay for waiting to receive response of query
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
Christopher Haster |
18:2cb1fffed50c | 1 | /* Copyright (c) 2013 Henry Leinen (henry[dot]leinen [at] online [dot] de) |
Christopher Haster |
18:2cb1fffed50c | 2 | * |
Christopher Haster |
18:2cb1fffed50c | 3 | * Permission is hereby granted, free of charge, to any person obtaining a copy of this software |
Christopher Haster |
18:2cb1fffed50c | 4 | * and associated documentation files (the "Software"), to deal in the Software without restriction, |
Christopher Haster |
18:2cb1fffed50c | 5 | * including without limitation the rights to use, copy, modify, merge, publish, distribute, |
Christopher Haster |
18:2cb1fffed50c | 6 | * sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is |
Christopher Haster |
18:2cb1fffed50c | 7 | * furnished to do so, subject to the following conditions: |
Christopher Haster |
18:2cb1fffed50c | 8 | * |
Christopher Haster |
18:2cb1fffed50c | 9 | * The above copyright notice and this permission notice shall be included in all copies or |
Christopher Haster |
18:2cb1fffed50c | 10 | * substantial portions of the Software. |
Christopher Haster |
18:2cb1fffed50c | 11 | * |
Christopher Haster |
18:2cb1fffed50c | 12 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING |
Christopher Haster |
18:2cb1fffed50c | 13 | * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND |
Christopher Haster |
18:2cb1fffed50c | 14 | * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, |
Christopher Haster |
18:2cb1fffed50c | 15 | * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
Christopher Haster |
18:2cb1fffed50c | 16 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. |
Christopher Haster |
18:2cb1fffed50c | 17 | */ |
Christopher Haster |
18:2cb1fffed50c | 18 | #include "DnsQuery.h" |
Christopher Haster |
18:2cb1fffed50c | 19 | #include <stdio.h> |
Christopher Haster |
18:2cb1fffed50c | 20 | #include <string.h> |
Christopher Haster |
18:2cb1fffed50c | 21 | |
Christopher Haster |
18:2cb1fffed50c | 22 | |
Christopher Haster |
18:2cb1fffed50c | 23 | #define DNS_COUNT (sizeof DNS_IPS / sizeof DNS_IPS[0]) |
Christopher Haster |
18:2cb1fffed50c | 24 | const char *DNS_IPS[] = { |
Christopher Haster |
18:2cb1fffed50c | 25 | "8.8.8.8", |
Christopher Haster |
18:2cb1fffed50c | 26 | "209.244.0.3", |
Christopher Haster |
18:2cb1fffed50c | 27 | "84.200.69.80", |
Christopher Haster |
18:2cb1fffed50c | 28 | "8.26.56.26", |
Christopher Haster |
18:2cb1fffed50c | 29 | "208.67.222.222" |
Christopher Haster |
18:2cb1fffed50c | 30 | }; |
Christopher Haster |
18:2cb1fffed50c | 31 | |
Christopher Haster |
18:2cb1fffed50c | 32 | static bool isIP(const char *host) |
Christopher Haster |
18:2cb1fffed50c | 33 | { |
Christopher Haster |
18:2cb1fffed50c | 34 | int i; |
Christopher Haster |
18:2cb1fffed50c | 35 | |
Christopher Haster |
18:2cb1fffed50c | 36 | for (i = 0; host[i]; i++) { |
Christopher Haster |
18:2cb1fffed50c | 37 | if (!(host[i] >= '0' && host[i] <= '9') && host[i] != '.') { |
Christopher Haster |
18:2cb1fffed50c | 38 | return false; |
Christopher Haster |
18:2cb1fffed50c | 39 | } |
Christopher Haster |
18:2cb1fffed50c | 40 | } |
Christopher Haster |
18:2cb1fffed50c | 41 | |
Christopher Haster |
18:2cb1fffed50c | 42 | // Ending with '.' garuntees host |
Christopher Haster |
18:2cb1fffed50c | 43 | if (i > 0 && host[i-1] == '.') { |
Christopher Haster |
18:2cb1fffed50c | 44 | return false; |
Christopher Haster |
18:2cb1fffed50c | 45 | } |
Christopher Haster |
18:2cb1fffed50c | 46 | |
Christopher Haster |
18:2cb1fffed50c | 47 | return true; |
Christopher Haster |
18:2cb1fffed50c | 48 | } |
Christopher Haster |
18:2cb1fffed50c | 49 | |
Christopher Haster |
18:2cb1fffed50c | 50 | |
Christopher Haster |
18:2cb1fffed50c | 51 | static bool parseRR(uint8_t *resp, int &c, char *adr) |
Christopher Haster |
18:2cb1fffed50c | 52 | { |
Christopher Haster |
18:2cb1fffed50c | 53 | int n = 0; |
Christopher Haster |
18:2cb1fffed50c | 54 | while((n=resp[c++]) != 0) { |
Christopher Haster |
18:2cb1fffed50c | 55 | if ((n & 0xc0) != 0) { |
Christopher Haster |
18:2cb1fffed50c | 56 | // This is a link |
Christopher Haster |
18:2cb1fffed50c | 57 | c++; |
Christopher Haster |
18:2cb1fffed50c | 58 | break; |
Christopher Haster |
18:2cb1fffed50c | 59 | } else { |
Christopher Haster |
18:2cb1fffed50c | 60 | // skip this segment, not interested in string domain names |
Christopher Haster |
18:2cb1fffed50c | 61 | c+= n; |
Christopher Haster |
18:2cb1fffed50c | 62 | } |
Christopher Haster |
18:2cb1fffed50c | 63 | } |
Christopher Haster |
18:2cb1fffed50c | 64 | |
Christopher Haster |
18:2cb1fffed50c | 65 | int TYPE = (((int)resp[c])<<8) + resp[c+1]; |
Christopher Haster |
18:2cb1fffed50c | 66 | int CLASS = (((int)resp[c+2])<<8) + resp[c+3]; |
Christopher Haster |
18:2cb1fffed50c | 67 | int RDLENGTH = (((int)resp[c+8])<<8) + resp[c+9]; |
Christopher Haster |
18:2cb1fffed50c | 68 | |
Christopher Haster |
18:2cb1fffed50c | 69 | c+= 10; |
Christopher Haster |
18:2cb1fffed50c | 70 | if ((CLASS == 1) && (TYPE == 1)) { |
Christopher Haster |
18:2cb1fffed50c | 71 | sprintf(adr,"%d.%d.%d.%d", resp[c], resp[c+1], resp[c+2], resp[c+3]); |
Christopher Haster |
18:2cb1fffed50c | 72 | c+= RDLENGTH; |
Christopher Haster |
18:2cb1fffed50c | 73 | return true; |
Christopher Haster |
18:2cb1fffed50c | 74 | } |
Christopher Haster |
18:2cb1fffed50c | 75 | c+= RDLENGTH; |
Christopher Haster |
18:2cb1fffed50c | 76 | |
Christopher Haster |
18:2cb1fffed50c | 77 | return false; |
Christopher Haster |
18:2cb1fffed50c | 78 | } |
Christopher Haster |
18:2cb1fffed50c | 79 | |
Christopher Haster |
18:2cb1fffed50c | 80 | |
Christopher Haster |
18:2cb1fffed50c | 81 | static bool resolve(unsigned char *resp, char *ipaddress) |
Christopher Haster |
18:2cb1fffed50c | 82 | { |
Christopher Haster |
18:2cb1fffed50c | 83 | |
Christopher Haster |
18:2cb1fffed50c | 84 | int ID = (((int)resp[0]) <<8) + resp[1]; |
Christopher Haster |
18:2cb1fffed50c | 85 | int QR = resp[2] >>7; |
Christopher Haster |
18:2cb1fffed50c | 86 | int Opcode = (resp[2]>>3) & 0x0F; |
Christopher Haster |
18:2cb1fffed50c | 87 | int RCODE = (resp[3] & 0x0F); |
Christopher Haster |
18:2cb1fffed50c | 88 | int ANCOUNT = (((int)resp[6])<<8)+ resp[7]; |
Christopher Haster |
18:2cb1fffed50c | 89 | |
Christopher Haster |
18:2cb1fffed50c | 90 | if ((ID != 1) || (QR != 1) || (Opcode != 0) || (RCODE != 0)) { |
Christopher Haster |
18:2cb1fffed50c | 91 | return false; |
Christopher Haster |
18:2cb1fffed50c | 92 | } |
Christopher Haster |
18:2cb1fffed50c | 93 | |
Christopher Haster |
18:2cb1fffed50c | 94 | int c = 12; |
Christopher Haster |
18:2cb1fffed50c | 95 | int d; |
Christopher Haster |
18:2cb1fffed50c | 96 | // Skip domain question |
Christopher Haster |
18:2cb1fffed50c | 97 | while( (d=resp[c++]) != 0) { |
Christopher Haster |
18:2cb1fffed50c | 98 | c+=d; |
Christopher Haster |
18:2cb1fffed50c | 99 | } |
Christopher Haster |
18:2cb1fffed50c | 100 | c+= 4; // skip QTYPE and QCLASS |
Christopher Haster |
18:2cb1fffed50c | 101 | |
Christopher Haster |
18:2cb1fffed50c | 102 | // Here comes the resource record |
Christopher Haster |
18:2cb1fffed50c | 103 | for (int ans = 0 ; ans < ANCOUNT; ans++) { |
Christopher Haster |
18:2cb1fffed50c | 104 | if (parseRR(resp, c, ipaddress)) { |
Christopher Haster |
18:2cb1fffed50c | 105 | return true; |
Christopher Haster |
18:2cb1fffed50c | 106 | } |
Christopher Haster |
18:2cb1fffed50c | 107 | } |
Christopher Haster |
18:2cb1fffed50c | 108 | |
Christopher Haster |
18:2cb1fffed50c | 109 | return false; |
Christopher Haster |
18:2cb1fffed50c | 110 | } |
Christopher Haster |
18:2cb1fffed50c | 111 | |
Christopher Haster |
18:2cb1fffed50c | 112 | static int32_t query(UDPSocket *socket, const SocketAddress &addr, const char *hostname, char *ipaddress) |
Christopher Haster |
18:2cb1fffed50c | 113 | { |
Christopher Haster |
18:2cb1fffed50c | 114 | int len = 0; |
Christopher Haster |
18:2cb1fffed50c | 115 | if (hostname == NULL) { |
Christopher Haster |
18:2cb1fffed50c | 116 | return false; |
Christopher Haster |
18:2cb1fffed50c | 117 | } |
Christopher Haster |
18:2cb1fffed50c | 118 | len = strlen(hostname); |
Christopher Haster |
18:2cb1fffed50c | 119 | if ((len > 128) || (len == 0)) { |
Christopher Haster |
18:2cb1fffed50c | 120 | return false; |
Christopher Haster |
18:2cb1fffed50c | 121 | } |
Christopher Haster |
18:2cb1fffed50c | 122 | |
Christopher Haster |
18:2cb1fffed50c | 123 | int packetlen = /* size of HEADER structure */ 12 + /* size of QUESTION Structure */5 + len + 1; |
Christopher Haster |
18:2cb1fffed50c | 124 | uint8_t *packet = new uint8_t[packetlen]; /* this is the UDP packet to send to the DNS */ |
Christopher Haster |
18:2cb1fffed50c | 125 | if (packet == NULL) { |
Christopher Haster |
18:2cb1fffed50c | 126 | return false; |
Christopher Haster |
18:2cb1fffed50c | 127 | } |
Christopher Haster |
18:2cb1fffed50c | 128 | |
Christopher Haster |
18:2cb1fffed50c | 129 | // Fill the header |
Christopher Haster |
18:2cb1fffed50c | 130 | memset(packet, 0, packetlen); |
Christopher Haster |
18:2cb1fffed50c | 131 | packet[1] = 1; // ID = 1 |
Christopher Haster |
18:2cb1fffed50c | 132 | packet[5] = 1; // QDCOUNT = 1 (contains one question) |
Christopher Haster |
18:2cb1fffed50c | 133 | packet[2] = 1; // recursion requested |
Christopher Haster |
18:2cb1fffed50c | 134 | |
Christopher Haster |
18:2cb1fffed50c | 135 | int c = 13; // point to NAME element in question section or request |
Christopher Haster |
18:2cb1fffed50c | 136 | int cnt = 12; // points to the counter of |
Christopher Haster |
18:2cb1fffed50c | 137 | packet[cnt] = 0; |
Christopher Haster |
18:2cb1fffed50c | 138 | for (int i = 0 ; i < len ; i++) { |
Christopher Haster |
18:2cb1fffed50c | 139 | if (hostname[i] != '.') { |
Christopher Haster |
18:2cb1fffed50c | 140 | // Copy the character and increment the character counter |
Christopher Haster |
18:2cb1fffed50c | 141 | packet[cnt]++; |
Christopher Haster |
18:2cb1fffed50c | 142 | packet[c++] = hostname[i]; |
Christopher Haster |
18:2cb1fffed50c | 143 | } else { |
Christopher Haster |
18:2cb1fffed50c | 144 | // Finished with this part, so go to the next |
Christopher Haster |
18:2cb1fffed50c | 145 | cnt = c++; |
Christopher Haster |
18:2cb1fffed50c | 146 | packet[cnt] = 0; |
Christopher Haster |
18:2cb1fffed50c | 147 | } |
Christopher Haster |
18:2cb1fffed50c | 148 | } |
Christopher Haster |
18:2cb1fffed50c | 149 | |
Christopher Haster |
18:2cb1fffed50c | 150 | // Terminate this domain name with a zero entry |
Christopher Haster |
18:2cb1fffed50c | 151 | packet[c++] = 0; |
Christopher Haster |
18:2cb1fffed50c | 152 | |
Christopher Haster |
18:2cb1fffed50c | 153 | // Set QTYPE |
Christopher Haster |
18:2cb1fffed50c | 154 | packet[c++] = 0; |
Christopher Haster |
18:2cb1fffed50c | 155 | packet[c++] = 1; |
Christopher Haster |
18:2cb1fffed50c | 156 | // Set QCLASS |
Christopher Haster |
18:2cb1fffed50c | 157 | packet[c++] = 0; |
Christopher Haster |
18:2cb1fffed50c | 158 | packet[c++] = 1; |
Christopher Haster |
18:2cb1fffed50c | 159 | |
Christopher Haster |
18:2cb1fffed50c | 160 | |
Christopher Haster |
18:2cb1fffed50c | 161 | if (socket->sendto(addr, packet, packetlen) < 0) { |
Christopher Haster |
18:2cb1fffed50c | 162 | delete packet; |
Christopher Haster |
18:2cb1fffed50c | 163 | return false; |
Christopher Haster |
18:2cb1fffed50c | 164 | } |
Christopher Haster |
18:2cb1fffed50c | 165 | delete packet; |
kaizen | 19:4c6f4b6036e6 | 166 | wait_ms(500); |
Christopher Haster |
18:2cb1fffed50c | 167 | |
Christopher Haster |
18:2cb1fffed50c | 168 | packet = new uint8_t [1024]; |
Christopher Haster |
18:2cb1fffed50c | 169 | |
Christopher Haster |
18:2cb1fffed50c | 170 | // Receive the answer from DNS |
Christopher Haster |
18:2cb1fffed50c | 171 | int response_length = 0; |
Christopher Haster |
18:2cb1fffed50c | 172 | response_length = socket->recvfrom(NULL, packet, 1024); |
Christopher Haster |
18:2cb1fffed50c | 173 | |
Christopher Haster |
18:2cb1fffed50c | 174 | if (response_length > 0 ) { |
Christopher Haster |
18:2cb1fffed50c | 175 | if (!resolve(packet, ipaddress)) { |
Christopher Haster |
18:2cb1fffed50c | 176 | delete packet; |
Christopher Haster |
18:2cb1fffed50c | 177 | return NSAPI_ERROR_DNS_FAILURE; |
Christopher Haster |
18:2cb1fffed50c | 178 | } |
Christopher Haster |
18:2cb1fffed50c | 179 | |
Christopher Haster |
18:2cb1fffed50c | 180 | // cleanup and return |
Christopher Haster |
18:2cb1fffed50c | 181 | delete packet; |
Christopher Haster |
18:2cb1fffed50c | 182 | return 0; |
Christopher Haster |
18:2cb1fffed50c | 183 | } |
Christopher Haster |
18:2cb1fffed50c | 184 | |
Christopher Haster |
18:2cb1fffed50c | 185 | delete packet; |
Christopher Haster |
18:2cb1fffed50c | 186 | return NSAPI_ERROR_DNS_FAILURE; |
Christopher Haster |
18:2cb1fffed50c | 187 | } |
Christopher Haster |
18:2cb1fffed50c | 188 | |
Christopher Haster |
18:2cb1fffed50c | 189 | int32_t dnsQuery(NetworkStack *iface, const char *host, char *ip) |
Christopher Haster |
18:2cb1fffed50c | 190 | { |
Christopher Haster |
18:2cb1fffed50c | 191 | if (isIP(host)) { |
Christopher Haster |
18:2cb1fffed50c | 192 | strcpy(ip, host); |
Christopher Haster |
18:2cb1fffed50c | 193 | return 0; |
Christopher Haster |
18:2cb1fffed50c | 194 | } |
Christopher Haster |
18:2cb1fffed50c | 195 | |
Christopher Haster |
18:2cb1fffed50c | 196 | UDPSocket sock(iface); |
Christopher Haster |
18:2cb1fffed50c | 197 | |
Christopher Haster |
18:2cb1fffed50c | 198 | for (unsigned i = 0; i < DNS_COUNT; i++) { |
Christopher Haster |
18:2cb1fffed50c | 199 | return query(&sock, SocketAddress(DNS_IPS[0], 53), host, ip); |
Christopher Haster |
18:2cb1fffed50c | 200 | } |
Christopher Haster |
18:2cb1fffed50c | 201 | |
Christopher Haster |
18:2cb1fffed50c | 202 | return NSAPI_ERROR_DNS_FAILURE; |
Christopher Haster |
18:2cb1fffed50c | 203 | } |
Christopher Haster |
18:2cb1fffed50c | 204 | |
Christopher Haster |
18:2cb1fffed50c | 205 | int32_t dnsQuery(UDPSocket *socket, const char *host, char *ip) |
Christopher Haster |
18:2cb1fffed50c | 206 | { |
Christopher Haster |
18:2cb1fffed50c | 207 | if (isIP(host)) { |
Christopher Haster |
18:2cb1fffed50c | 208 | strcpy(ip, host); |
Christopher Haster |
18:2cb1fffed50c | 209 | return 0; |
Christopher Haster |
18:2cb1fffed50c | 210 | } |
Christopher Haster |
18:2cb1fffed50c | 211 | |
Christopher Haster |
18:2cb1fffed50c | 212 | for (unsigned i = 0; i < DNS_COUNT; i++) { |
Christopher Haster |
18:2cb1fffed50c | 213 | return query(socket, SocketAddress(DNS_IPS[0], 53), host, ip); |
Christopher Haster |
18:2cb1fffed50c | 214 | } |
Christopher Haster |
18:2cb1fffed50c | 215 | |
Christopher Haster |
18:2cb1fffed50c | 216 | return NSAPI_ERROR_DNS_FAILURE; |
Christopher Haster |
18:2cb1fffed50c | 217 | } |