Mateusz Jaskula / Mbed 2 deprecated KL25Z_TangoIO

KL25 driver for Tango Control System

Dependencies:   mbed

DNSClient/DNSClient.cpp@2:9fe6f1e273b4, 2014-08-28 (annotated)

Committer:
jskl
Date:
Thu Aug 28 07:50:06 2014 +0000
Revision:
2:9fe6f1e273b4
Parent:
0:5d27c333afa6 
Fixed bugs in JSON format replies

Who changed what in which revision?

UserRevisionLine numberNew contents of line
jskl 0:5d27c333afa6 1 // DNSClient.cpp 2013/8/27
jskl 0:5d27c333afa6 2 #include "mbed.h"
jskl 0:5d27c333afa6 3 #include "mbed_debug.h"
jskl 0:5d27c333afa6 4 #include "DNSClient.h"
jskl 0:5d27c333afa6 5 #include "UDPSocket.h"
jskl 0:5d27c333afa6 6 #include "dnsname.h"
jskl 0:5d27c333afa6 7 #include "wiznet.h"
jskl 0:5d27c333afa6 8
jskl 0:5d27c333afa6 9 #define DBG_DNS 0
jskl 0:5d27c333afa6 10
jskl 0:5d27c333afa6 11 #if DBG_DNS
jskl 0:5d27c333afa6 12 #define DBG2(...) do{debug("[DNS]%p %d %s ", this,__LINE__,__PRETTY_FUNCTION__); debug(__VA_ARGS__); } while(0);
jskl 0:5d27c333afa6 13 #else
jskl 0:5d27c333afa6 14 #define DBG2(...) while(0);
jskl 0:5d27c333afa6 15 #endif
jskl 0:5d27c333afa6 16
jskl 0:5d27c333afa6 17 DNSClient::DNSClient(const char* hostname) : m_state(MYNETDNS_START), m_udp(NULL) {
jskl 0:5d27c333afa6 18 m_hostname = hostname;
jskl 0:5d27c333afa6 19 }
jskl 0:5d27c333afa6 20
jskl 0:5d27c333afa6 21 DNSClient::DNSClient(Endpoint* pHost) : m_state(MYNETDNS_START), m_udp(NULL) {
jskl 0:5d27c333afa6 22 }
jskl 0:5d27c333afa6 23
jskl 0:5d27c333afa6 24 DNSClient::~DNSClient() {
jskl 0:5d27c333afa6 25 if (m_udp) {
jskl 0:5d27c333afa6 26 delete m_udp;
jskl 0:5d27c333afa6 27 }
jskl 0:5d27c333afa6 28 }
jskl 0:5d27c333afa6 29
jskl 0:5d27c333afa6 30 void DNSClient::callback()
jskl 0:5d27c333afa6 31 {
jskl 0:5d27c333afa6 32 uint8_t buf[512];
jskl 0:5d27c333afa6 33 Endpoint host;
jskl 0:5d27c333afa6 34 int len = m_udp->receiveFrom(host, (char*)buf, sizeof(buf));
jskl 0:5d27c333afa6 35 if (len < 0) {
jskl 0:5d27c333afa6 36 return;
jskl 0:5d27c333afa6 37 }
jskl 0:5d27c333afa6 38 if (memcmp(buf+0, m_id, 2) != 0) { //verify
jskl 0:5d27c333afa6 39 return;
jskl 0:5d27c333afa6 40 }
jskl 0:5d27c333afa6 41 int rcode = response(buf, len);
jskl 0:5d27c333afa6 42 if (rcode == 0) {
jskl 0:5d27c333afa6 43 m_state = MYNETDNS_OK;
jskl 0:5d27c333afa6 44 } else {
jskl 0:5d27c333afa6 45 m_state = MYNETDNS_NOTFOUND;
jskl 0:5d27c333afa6 46 }
jskl 0:5d27c333afa6 47 }
jskl 0:5d27c333afa6 48
jskl 0:5d27c333afa6 49 int DNSClient::response(uint8_t buf[], int size) {
jskl 0:5d27c333afa6 50 int rcode = buf[3] & 0x0f;
jskl 0:5d27c333afa6 51 if (rcode != 0) {
jskl 0:5d27c333afa6 52 return rcode;
jskl 0:5d27c333afa6 53 }
jskl 0:5d27c333afa6 54 int qdcount = buf[4]<<8|buf[5];
jskl 0:5d27c333afa6 55 int ancount = buf[6]<<8|buf[7];
jskl 0:5d27c333afa6 56 int pos = 12;
jskl 0:5d27c333afa6 57 while(qdcount-- > 0) {
jskl 0:5d27c333afa6 58 dnsname qname(buf);
jskl 0:5d27c333afa6 59 pos = qname.decode(pos); // qname
jskl 0:5d27c333afa6 60 pos += 4; // qtype qclass
jskl 0:5d27c333afa6 61 }
jskl 0:5d27c333afa6 62 while(ancount-- > 0) {
jskl 0:5d27c333afa6 63 dnsname name(buf);
jskl 0:5d27c333afa6 64 pos = name.decode(pos); // name
jskl 0:5d27c333afa6 65 int type = buf[pos]<<8|buf[pos+1];
jskl 0:5d27c333afa6 66 pos += 8; // type class TTL
jskl 0:5d27c333afa6 67 int rdlength = buf[pos]<<8|buf[pos+1]; pos += 2;
jskl 0:5d27c333afa6 68 int rdata_pos = pos;
jskl 0:5d27c333afa6 69 pos += rdlength;
jskl 0:5d27c333afa6 70 if (type == 1) { // A record
jskl 0:5d27c333afa6 71 ip = (buf[rdata_pos]<<24) | (buf[rdata_pos+1]<<16) | (buf[rdata_pos+2]<<8) | buf[rdata_pos+3];
jskl 0:5d27c333afa6 72 }
jskl 0:5d27c333afa6 73 #if DBG_DNS
jskl 0:5d27c333afa6 74 printf("%s", name.str.c_str());
jskl 0:5d27c333afa6 75 if (type == 1) {
jskl 0:5d27c333afa6 76 printf(" A %d.%d.%d.%d\n",
jskl 0:5d27c333afa6 77 buf[rdata_pos],buf[rdata_pos+1],buf[rdata_pos+2],buf[rdata_pos+3]);
jskl 0:5d27c333afa6 78 } else if (type == 5) {
jskl 0:5d27c333afa6 79 dnsname rdname(buf);
jskl 0:5d27c333afa6 80 rdname.decode(rdata_pos);
jskl 0:5d27c333afa6 81 printf(" CNAME %s\n", rdname.str.c_str());
jskl 0:5d27c333afa6 82 } else {
jskl 0:5d27c333afa6 83 printf(" TYPE:%d", type);
jskl 0:5d27c333afa6 84 printfBytes(" RDATA:", &buf[rdata_pos], rdlength);
jskl 0:5d27c333afa6 85 }
jskl 0:5d27c333afa6 86 #endif
jskl 0:5d27c333afa6 87 }
jskl 0:5d27c333afa6 88 return rcode;
jskl 0:5d27c333afa6 89 }
jskl 0:5d27c333afa6 90
jskl 0:5d27c333afa6 91 int DNSClient::query(uint8_t buf[], int size, const char* hostname) {
jskl 0:5d27c333afa6 92 const uint8_t header[] = {
jskl 0:5d27c333afa6 93 0x00,0x00,0x01,0x00, // id=0x0000 QR=0 rd=1 opcode=0 rcode=0
jskl 0:5d27c333afa6 94 0x00,0x01,0x00,0x00, // qdcount=1 ancount=0
jskl 0:5d27c333afa6 95 0x00,0x00,0x00,0x00};// nscount=0 arcount=0
jskl 0:5d27c333afa6 96 const uint8_t tail[] = {0x00,0x01,0x00,0x01}; // qtype=A qclass=IN
jskl 0:5d27c333afa6 97 memcpy(buf, header, sizeof(header));
jskl 0:5d27c333afa6 98 int t = rand();
jskl 0:5d27c333afa6 99 m_id[0] = t>>8;
jskl 0:5d27c333afa6 100 m_id[1] = t;
jskl 0:5d27c333afa6 101 memcpy(buf, m_id, 2);
jskl 0:5d27c333afa6 102 dnsname qname(buf);
jskl 0:5d27c333afa6 103 int pos = qname.encode(sizeof(header), (char*)hostname);
jskl 0:5d27c333afa6 104 memcpy(buf+pos, tail, sizeof(tail));
jskl 0:5d27c333afa6 105 pos += sizeof(tail);
jskl 0:5d27c333afa6 106 return pos;
jskl 0:5d27c333afa6 107 }
jskl 0:5d27c333afa6 108
jskl 0:5d27c333afa6 109 void DNSClient::resolve(const char* hostname) {
jskl 0:5d27c333afa6 110 if (m_udp == NULL) {
jskl 0:5d27c333afa6 111 m_udp = new UDPSocket;
jskl 0:5d27c333afa6 112 }
jskl 0:5d27c333afa6 113 m_udp->init();
jskl 0:5d27c333afa6 114 m_udp->set_blocking(false);
jskl 0:5d27c333afa6 115 Endpoint server;
jskl 0:5d27c333afa6 116 server.set_address("8.8.8.8", 53); // DNS
jskl 0:5d27c333afa6 117 m_udp->bind(rand()&0x7fff);
jskl 0:5d27c333afa6 118 uint8_t buf[256];
jskl 0:5d27c333afa6 119 int size = query(buf, sizeof(buf), hostname);
jskl 0:5d27c333afa6 120 #if DBG_DNS
jskl 0:5d27c333afa6 121 printf("hostname:[%s]\n", hostname);
jskl 0:5d27c333afa6 122 printHex(buf, size);
jskl 0:5d27c333afa6 123 #endif
jskl 0:5d27c333afa6 124 m_udp->sendTo(server, (char*)buf, size);
jskl 0:5d27c333afa6 125 m_interval.reset();
jskl 0:5d27c333afa6 126 m_interval.start();
jskl 0:5d27c333afa6 127 }
jskl 0:5d27c333afa6 128
jskl 0:5d27c333afa6 129 void DNSClient::poll() {
jskl 0:5d27c333afa6 130 #if DBG_DNS
jskl 0:5d27c333afa6 131 printf("%p m_state: %d, m_udp: %p\n", this, m_state, m_udp);
jskl 0:5d27c333afa6 132 wait_ms(400);
jskl 0:5d27c333afa6 133 #endif
jskl 0:5d27c333afa6 134 switch(m_state) {
jskl 0:5d27c333afa6 135 case MYNETDNS_START:
jskl 0:5d27c333afa6 136 m_retry = 0;
jskl 0:5d27c333afa6 137 resolve(m_hostname);
jskl 0:5d27c333afa6 138 m_state = MYNETDNS_PROCESSING;
jskl 0:5d27c333afa6 139 break;
jskl 0:5d27c333afa6 140 case MYNETDNS_PROCESSING:
jskl 0:5d27c333afa6 141 break;
jskl 0:5d27c333afa6 142 case MYNETDNS_NOTFOUND:
jskl 0:5d27c333afa6 143 break;
jskl 0:5d27c333afa6 144 case MYNETDNS_ERROR:
jskl 0:5d27c333afa6 145 break;
jskl 0:5d27c333afa6 146 case MYNETDNS_OK:
jskl 0:5d27c333afa6 147 DBG2("m_retry=%d, m_interval=%d\n", m_retry, m_interval.read_ms());
jskl 0:5d27c333afa6 148 break;
jskl 0:5d27c333afa6 149 }
jskl 0:5d27c333afa6 150 if (m_interval.read_ms() > 1000) {
jskl 0:5d27c333afa6 151 m_interval.stop();
jskl 0:5d27c333afa6 152 DBG2("timeout m_retry=%d\n", m_retry);
jskl 0:5d27c333afa6 153 if (++m_retry >= 2) {
jskl 0:5d27c333afa6 154 m_state = MYNETDNS_ERROR;
jskl 0:5d27c333afa6 155 } else {
jskl 0:5d27c333afa6 156 resolve(m_hostname);
jskl 0:5d27c333afa6 157 m_state = MYNETDNS_PROCESSING;
jskl 0:5d27c333afa6 158 }
jskl 0:5d27c333afa6 159 }
jskl 0:5d27c333afa6 160 }
jskl 0:5d27c333afa6 161
jskl 0:5d27c333afa6 162 bool DNSClient::lookup(const char* hostname) {
jskl 0:5d27c333afa6 163 m_hostname = hostname;
jskl 0:5d27c333afa6 164 m_state = MYNETDNS_START;
jskl 0:5d27c333afa6 165 while(1) {
jskl 0:5d27c333afa6 166 poll();
jskl 0:5d27c333afa6 167 callback();
jskl 0:5d27c333afa6 168 if (m_state != MYNETDNS_PROCESSING) {
jskl 0:5d27c333afa6 169 break;
jskl 0:5d27c333afa6 170 }
jskl 0:5d27c333afa6 171 }
jskl 0:5d27c333afa6 172 return m_state == MYNETDNS_OK;
jskl 0:5d27c333afa6 173 }
jskl 0:5d27c333afa6 174