Revision 2:12d08f0f20cf, committed 2015-08-05

Comitter:

sarahmarshy

Date:

Wed Aug 05 21:58:57 2015 +0000

Parent:

1:5d978992a518

Child:

3:5705fdae6185

Commit message:

Removed ipAdress struct. Compatible with NetworkSocket API

Changed in this revision

--- a/DnsQuery.cpp	Fri Jul 24 22:43:25 2015 +0000
+++ b/DnsQuery.cpp	Wed Aug 05 21:58:57 2015 +0000
@@ -42,22 +42,18 @@
     socket = sock;
 }
 
-bool DnsQuery::gethostbyname(const char* hostname, IPADDRESS_t &ipaddress)
+bool DnsQuery::gethostbyname(const char* hostname, char* resolvedIp)
 {
-    IPADDRESS_t dnsIp_1 = {209,244,0,3};
-    IPADDRESS_t dnsIp_2 = {8,8,8,8};
-    IPADDRESS_t dnsIp_3 = {84,200,69,80};
-    IPADDRESS_t dnsIp_4 = {8,26,56,26};
-    IPADDRESS_t dnsIp_5 = {208,67,222,222};
+    char * dnsIPs[] = {
+        "8.8.8.8",
+        "209.244.0.3",
+        "84.200.69.80",
+        "8.26.56.26",
+        "208.67.222.222"
+    };
     for(int i = 0; i<5; i++){
-        switch(i) {
-            case 0 : _dnsip= dnsIp_1; break ;
-            case 1 : _dnsip= dnsIp_2;  break ;
-            case 2 : _dnsip= dnsIp_3;  break ;           
-            case 3 : _dnsip= dnsIp_4;  break ;      
-            case 4 : _dnsip= dnsIp_5;  break ;  
-        }
-        if(this->getIP(hostname, ipaddress)){
+        _dnsip = dnsIPs[i];
+        if(this->getIP(hostname, resolvedIp)){
             return true;   
         }
            
@@ -66,7 +62,7 @@
     
 }
 
-bool DnsQuery::getIP(const char* hostname, IPADDRESS_t &ipaddress)
+bool DnsQuery::getIP(const char* hostname, char* ipaddress)
 {
     INFO("%s", hostname);
     int len = 0;
@@ -75,7 +71,6 @@
     len = strlen(hostname);
     if ((len >128) || (len == 0))
         return false;
-    memset (&ipaddress, 0, sizeof(ipaddress));
     
     int packetlen = /* size of HEADER structure */ 12 + /* size of QUESTION Structure */5 + len + 1;
     char *packet = new char[packetlen]; /* this is the UDP packet to send to the DNS */
@@ -115,7 +110,7 @@
     
     
     //  Ready to send to DNS
-    socket->setAddressPort(_dnsip.string_format(), 53);
+    socket->setAddressPort(_dnsip, 53);
     socket->open();
    
     INFO("Sending packet of length %d",packetlen);
@@ -128,40 +123,34 @@
         delete packet;
         return false;
     }
-    
     delete packet;
     
     packet = new char [1024];
-    if (packet == NULL) {
-        return false;
-    }
     
     //  Receive the answer from DNS
-    Timer t;
-    t.start();
     int response_length = 0;
-    while (t.read_ms() < 10000) {
-        INFO("Recieving");
-        response_length = socket->recv(packet, 1024);
+    INFO("Recieving");
+    response_length = socket->recv(packet, 1024);
         /*
         for( int i = 0 ; i < 1024; i++) {
             printf("%02x ", packet[i]);
         }
         */
-        if (response_length > 0 ) {
-            if (!resolve(packet, ipaddress)) {
-                break;
-            }
-                        
-            //  cleanup and return
+    if (response_length > 0 ) {
+        if (!resolve(packet, ipaddress)) {
+            socket->close();
             delete packet;
-            socket->close();
-            //INFO("Found this IP:%s",ipaddress.string_format());
-            return true;
-        } else {
-            ERR("SocketRecvFrom returned %d !", response_length);
+            ERR("NO IP FOUND\n");
+            return false;
         }
-    }    
+                        
+        //  cleanup and return
+        delete packet;
+        socket->close();
+        return true;
+    } else {
+        ERR("SocketRecvFrom returned %d !", response_length);
+    }
     socket->close();
     delete packet;
     ERR("NO IP FOUND\n");
@@ -169,7 +158,7 @@
 }
 
 
-bool DnsQuery::resolve(char* resp, IPADDRESS_t &ipaddress)
+bool DnsQuery::resolve(char* resp, char* ipaddress)
 {
     
     int ID = (((int)resp[0]) <<8) + resp[1];
@@ -202,10 +191,9 @@
     return false;
 }
 
-bool DnsQuery::parseRR(char *resp, int& c, IPADDRESS_t& adr )
+bool DnsQuery::parseRR(char *resp, int& c, char* adr )
 {
     int n = 0;
-    
     while( (n=resp[c++]) != 0) {
         if ((n & 0xc0) != 0) {
             //  This is a link
@@ -223,10 +211,7 @@
     INFO("Record of TYPE=%d and CLASS=%d detected !", TYPE, CLASS);
     c+= 10;
     if ((CLASS == 1) && (TYPE == 1)) {
-        adr.sin_addr.o1 = resp[c];
-        adr.sin_addr.o2 = resp[c+1];
-        adr.sin_addr.o3 = resp[c+2];
-        adr.sin_addr.o4 = resp[c+3];
+        sprintf(adr,"%d.%d.%d.%d", resp[c], resp[c+1], resp[c+2], resp[c+3]);
         c+= RDLENGTH;
         return true;
     } else {

--- a/DnsQuery.h	Fri Jul 24 22:43:25 2015 +0000
+++ b/DnsQuery.h	Wed Aug 05 21:58:57 2015 +0000
@@ -1,4 +1,4 @@
-/* Copyright (c) 2013 Henry Leinen (henry[dot]leinen [at] online [dot] de)
+/* 
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy of this software
  * and associated documentation files (the "Software"), to deal in the Software without restriction,
@@ -19,70 +19,33 @@
 #define __DNSQUERY_H__
 
 #include "SocketInterface.h"
-
-typedef struct {
-    union {
-        struct {
-            char o1, o2, o3, o4;
-        };
-        char o[4];
-    } sin_addr;
-    operator char* () { return (char*)this; }
-    char* string_format() { 
-        char ip[7];
-        sprintf(ip,"%d.%d.%d.%d", this->sin_addr.o1, this->sin_addr.o2, this->sin_addr.o3, this->sin_addr.o4);
-        return ip;
-    }
-} IPADDRESS_t;
-
-/** Class DnsQuery implements DNS over UDP functionality.
-  * Example as a typical use case :
-  * @code
-  * #include "mbed.h"
-  * #include "DnsQuery.h"
-  *
-  * void main(void)
-  * {
-  *     IPADDRESS_t ipAddress;  // will receive the ip address of the host
-  *     IPADDRESS_t dnsIp = { 192, 168, 178, 1 };      // Ip Address of the DNS server
-  *     
-  *     DnsQuery dns(Wifi::getInstance(), &dnsIp);
-  *     if (dns.gethostbyname("mbed.org", ipAddress)) {
-  *         printf("Ip-Address of mbed.org is %d.%d.%d.%d\n", ipAddress.sin_addr.o1, ipAddress.sin_addr.o2, ipAddress.sin_addr.o3, ipAddress.sin_addr.o4);
-  *     } else {
-  *         printf("Unable to obtain IP-Address\n");
-  *     }
-  * }
-  * @endcode
-  */
 class DnsQuery
 {
 public:
     /** Constructor to instantiate a DnsQuery object.
-      * @param wifi : A valid pointer to a Wifi Object, which can be used to obtain a UDP socket object.
-      * @param dnsip : A valid pointer which holds the IPAddress of the DNS server to query.
+      * @param wifi : A valid pointer to a UDP socket
       */
     DnsQuery(SocketInterface* sock);
     
     
     /** Function gethostbyname implements the functionality to query a domain name server for an IP-Address of a given hostname.
-      * @param hostname : the hostname of interest as a string.
+      * @param hostname : the hostname of interest as a string - format must be without http:// or www. IE google.com, mbed.org, etc
       * @param ipaddress : a reference to a IPADDRESS_t object which will receive the resolved IP Address of the host in question.
-      * @returns true if successfull, or false otherwise.
+      * @returns true if successful, or false otherwise.
       */
-    bool gethostbyname(const char* hostname, IPADDRESS_t &ipaddress);
+    bool gethostbyname(const char* hostname, char* ipaddress);
     /** Function gethostbyname implements the functionality to query a domain name server for an IP-Address of a given hostname.
       * @param hostname : the hostname of interest as a string.
       * @param ipaddress : a reference to a IPADDRESS_t object which will receive the resolved IP Address of the host in question.
-      * @returns true if successfull, or false otherwise.
+      * @returns true if successful, or false otherwise.
       */
-    bool getIP(const char* hostname, IPADDRESS_t &ipaddress);
+    bool getIP(const char* hostname, char* ipaddress);
 protected:
-    bool resolve(char* resp, IPADDRESS_t &ipaddress);
-    bool parseRR(char *resp, int& c, IPADDRESS_t& adr );
+    bool resolve(char* resp, char* ipaddress);
+    bool parseRR(char *resp, int& c, char* adr );
 
 protected:
-    IPADDRESS_t _dnsip;
+    char* _dnsip;
     char* _string_ip;
     SocketInterface* socket;