Added functions for setting and getting the hostname.

src/Dhcp.cpp

@@ -6,6 +6,8 @@
 #include "Dhcp.h"
 #include "utility/w5100.h"
 
+char DhcpClass::_hostName[HOST_NAME_LENGTH] = HOST_NAME;
+
 int DhcpClass::beginWithDHCP(uint8_t *mac, unsigned long timeout, unsigned long responseTimeout)
 {
 	_dhcpLeaseTime=0;
@@ -188,15 +190,15 @@ void DhcpClass::send_DHCP_MESSAGE(uint8_t messageType, uint16_t secondsElapsed)
 
 	// OPT - host name
 	buffer[16] = hostName;
-	buffer[17] = strlen(HOST_NAME) + 6; // length of hostname + last 3 bytes of mac address
-	strcpy((char*)&(buffer[18]), HOST_NAME);
+    buffer[17] = strlen(_hostName) + 6; // length of hostname + last 3 bytes of mac address
+    strcpy((char*)&(buffer[18]), _hostName);
 
-	printByte((char*)&(buffer[24]), _dhcpMacAddr[3]);
-	printByte((char*)&(buffer[26]), _dhcpMacAddr[4]);
-	printByte((char*)&(buffer[28]), _dhcpMacAddr[5]);
+    printByte((char*)&(buffer[(18 + strlen(_hostName))]), _dhcpMacAddr[3]);
+    printByte((char*)&(buffer[(20 + strlen(_hostName))]), _dhcpMacAddr[4]);
+    printByte((char*)&(buffer[(22 + strlen(_hostName))]), _dhcpMacAddr[5]);
 
-	//put data in W5100 transmit buffer
-	_dhcpUdpSocket.write(buffer, 30);
+    //put data in W5100 transmit buffer
+    _dhcpUdpSocket.write(buffer, (24 + strlen(_hostName)));
 
 	if (messageType == DHCP_REQUEST) {
 		buffer[0] = dhcpRequestedIPaddr;
@@ -431,3 +433,13 @@ void DhcpClass::printByte(char * buf, uint8_t n )
 		*str-- = c < 10 ? c + '0' : c + 'A' - 10;
 	} while(n);
 }
+
+void DhcpClass::setHostName(const char * newHostName) 
+{
+    strncpy(_hostName, newHostName, HOST_NAME_LENGTH-1);
+}
+
+char * DhcpClass::getHostName() 
+{
+    return _hostName;
+}

src/Dhcp.h

@@ -42,6 +42,7 @@
 #define MAGIC_COOKIE		0x63825363
 #define MAX_DHCP_OPT		16
 
+#define HOST_NAME_LENGTH 13 
 #define HOST_NAME "WIZnet"
 #define DEFAULT_LEASE	(900) //default lease time in seconds
 

src/Ethernet.cpp

@@ -184,6 +184,16 @@ IPAddress EthernetClass::gatewayIP()
 	return ret;
 }
 
+void EthernetClass::setHostName(const char * newHostName) 
+{
+	_dhcp->setHostName(newHostName);
+}
+
+char * EthernetClass::getHostName() 
+{
+	return _dhcp->getHostName();
+}
+
 void EthernetClass::setMACAddress(const uint8_t *mac_address)
 {
 	SPI.beginTransaction(SPI_ETHERNET_SETTINGS);
@@ -239,4 +249,5 @@ void EthernetClass::setRetransmissionCount(uint8_t num)
 
 
 
+
 EthernetClass Ethernet;

src/Ethernet.h

@@ -47,11 +47,15 @@
 // does not always seem to work in practice (maybe Wiznet bugs?)
 //#define ETHERNET_LARGE_BUFFERS
 
+// This is used to check from outside, if there is a function 
+// to set the hostname in the library. Inside the library it is not used.
+#define SET_HOSTNAME_AVAILABLE
 
 #include <Arduino.h>
 #include "Client.h"
 #include "Server.h"
 #include "Udp.h"
+#include "Dhcp.h"
 
 enum EthernetLinkStatus {
 	Unknown,
@@ -108,6 +112,10 @@ class EthernetClass {
 	friend class EthernetClient;
 	friend class EthernetServer;
 	friend class EthernetUDP;
+
+	static void setHostName(const char * newHostName);
+	static char * getHostName();
+
 private:
 	// Opens a socket(TCP or UDP or IP_RAW mode)
 	static uint8_t socketBegin(uint8_t protocol, uint16_t port);
@@ -297,6 +305,8 @@ class DhcpClass {
 	uint8_t _dhcp_state;
 	EthernetUDP _dhcpUdpSocket;
 
+	static char _hostName[HOST_NAME_LENGTH];
+
 	int request_DHCP_lease();
 	void reset_DHCP_lease();
 	void presend_DHCP();
@@ -313,9 +323,11 @@ class DhcpClass {
 
 	int beginWithDHCP(uint8_t *, unsigned long timeout = 60000, unsigned long responseTimeout = 4000);
 	int checkLease();
-};
 
+	static void setHostName(const char * newHostName);
+	static char * getHostName();
 
+};