Fix for issue 62, adding DHCP support. New begin() method added to EthernetClass which takes just a MAC address and gets the rest of its configuration information via DHCP. Examples updated to use the IPAddress class and some have been changed to get their config via DHCP.

Author: amcewen

libraries/Ethernet/Client.cpp

@@ -16,7 +16,7 @@ uint16_t Client::_srcport = 1024;
 Client::Client(uint8_t sock) : _sock(sock) {
 }
 
-Client::Client(uint8_t *ip, uint16_t port) : _ip(ip), _port(port), _sock(MAX_SOCK_NUM) {
+Client::Client(IPAddress& ip, uint16_t port) : _ip(ip), _port(port), _sock(MAX_SOCK_NUM) {
 }
 
 uint8_t Client::connect() {
@@ -38,7 +38,7 @@ uint8_t Client::connect() {
   if (_srcport == 0) _srcport = 1024;
   socket(_sock, SnMR::TCP, _srcport, 0);
 
-  if (!::connect(_sock, _ip, _port)) {
+  if (!::connect(_sock, _ip.raw_address(), _port)) {
     _sock = MAX_SOCK_NUM;
     return 0;
   }

libraries/Ethernet/Client.h

@@ -7,8 +7,8 @@ class Client : public Stream {
 
 public:
   Client();
-  Client(uint8_t);
-  Client(uint8_t *, uint16_t);
+  Client(uint8_t sock);
+  Client(IPAddress& ip, uint16_t port);
 
   uint8_t status();
   uint8_t connect();
@@ -31,7 +31,7 @@ class Client : public Stream {
 private:
   static uint16_t _srcport;
   uint8_t _sock;
-  uint8_t *_ip;
+  IPAddress _ip;
   uint16_t _port;
 };
 

libraries/Ethernet/Dhcp.cpp

@@ -0,0 +1,341 @@
+// DHCP Library v0.3 - April 25, 2009
+// Author: Jordan Terrell - blog.jordanterrell.com
+
+#include "w5100.h"
+
+#include <string.h>
+#include <stdlib.h>
+#include "Dhcp.h"
+#include "wiring.h"
+#include "util.h"
+
+int DhcpClass::beginWithDHCP(uint8_t *mac, unsigned long timeout, unsigned long responseTimeout)
+{
+    uint8_t dhcp_state = STATE_DHCP_START;
+    uint8_t messageType = 0;
+  
+    // zero out _dhcpMacAddr, _dhcpSubnetMask, _dhcpGatewayIp, _dhcpLocalIp, _dhcpDhcpServerIp, _dhcpDnsServerIp
+    memset(_dhcpMacAddr, 0, 26); 
+
+    memcpy((void*)_dhcpMacAddr, (void*)mac, 6);
+  
+    // Pick an initial transaction ID
+    _dhcpTransactionId = random(1UL, 2000UL);
+    _dhcpInitialTransactionId = _dhcpTransactionId;
+
+    if (_dhcpUdpSocket.begin(DHCP_CLIENT_PORT) == 0)
+    {
+      // Couldn't get a socket
+      return 0;
+    }
+    
+    presend_DHCP();
+    
+    int result = 0;
+    
+    unsigned long startTime = millis();
+    
+    while(dhcp_state != STATE_DHCP_LEASED)
+    {
+        if(dhcp_state == STATE_DHCP_START)
+        {
+            _dhcpTransactionId++;
+            
+            send_DHCP_MESSAGE(DHCP_DISCOVER, ((millis() - startTime) / 1000));
+            dhcp_state = STATE_DHCP_DISCOVER;
+        }
+        else if(dhcp_state == STATE_DHCP_DISCOVER)
+        {
+            uint32_t respId;
+            messageType = parseDHCPResponse(responseTimeout, respId);
+            if(messageType == DHCP_OFFER)
+            {
+                // We'll use the transaction ID that the offer came with,
+                // rather than the one we were up to
+                _dhcpTransactionId = respId;
+                send_DHCP_MESSAGE(DHCP_REQUEST, ((millis() - startTime) / 1000));
+                dhcp_state = STATE_DHCP_REQUEST;
+            }
+        }
+        else if(dhcp_state == STATE_DHCP_REQUEST)
+        {
+            uint32_t respId;
+            messageType = parseDHCPResponse(responseTimeout, respId);
+            if(messageType == DHCP_ACK)
+            {
+                dhcp_state = STATE_DHCP_LEASED;
+                result = 1;
+            }
+            else if(messageType == DHCP_NAK)
+                dhcp_state = STATE_DHCP_START;
+        }
+        
+        if(messageType == 255)
+        {
+            messageType = 0;
+            dhcp_state = STATE_DHCP_START;
+        }
+        
+        if(result != 1 && ((millis() - startTime) > timeout))
+            break;
+    }
+    
+    // We're done with the socket now
+    _dhcpUdpSocket.stop();
+    _dhcpTransactionId++;
+    
+    return result;
+}
+
+void DhcpClass::presend_DHCP()
+{
+}
+
+void DhcpClass::send_DHCP_MESSAGE(uint8_t messageType, uint16_t secondsElapsed)
+{
+    uint8_t buffer[32];
+    memset(buffer, 0, 32);
+    IPAddress dest_addr( 255, 255, 255, 255 ); // Broadcast address
+
+    if (-1 == _dhcpUdpSocket.beginPacket(dest_addr, DHCP_SERVER_PORT))
+    {
+        // FIXME Need to return errors
+        return;
+    }
+
+    buffer[0] = DHCP_BOOTREQUEST;   // op
+    buffer[1] = DHCP_HTYPE10MB;     // htype
+    buffer[2] = DHCP_HLENETHERNET;  // hlen
+    buffer[3] = DHCP_HOPS;          // hops
+
+    // xid
+    unsigned long xid = htonl(_dhcpTransactionId);
+    memcpy(buffer + 4, &(xid), 4);
+
+    // 8, 9 - seconds elapsed
+    buffer[8] = ((secondsElapsed & 0xff00) >> 8);
+    buffer[9] = (secondsElapsed & 0x00ff);
+
+    // flags
+    unsigned short flags = htons(DHCP_FLAGSBROADCAST);
+    memcpy(buffer + 10, &(flags), 2);
+
+    // ciaddr: already zeroed
+    // yiaddr: already zeroed
+    // siaddr: already zeroed
+    // giaddr: already zeroed
+
+    //put data in W5100 transmit buffer
+    _dhcpUdpSocket.write(buffer, 28);
+
+    memset(buffer, 0, 32); // clear local buffer
+
+    memcpy(buffer, _dhcpMacAddr, 6); // chaddr
+
+    //put data in W5100 transmit buffer
+    _dhcpUdpSocket.write(buffer, 16);
+
+    memset(buffer, 0, 32); // clear local buffer
+
+    // leave zeroed out for sname && file
+    // put in W5100 transmit buffer x 6 (192 bytes)
+  
+    for(int i = 0; i < 6; i++) {
+        _dhcpUdpSocket.write(buffer, 32);
+    }
+  
+    // OPT - Magic Cookie
+    buffer[0] = (uint8_t)((MAGIC_COOKIE >> 24)& 0xFF);
+    buffer[1] = (uint8_t)((MAGIC_COOKIE >> 16)& 0xFF);
+    buffer[2] = (uint8_t)((MAGIC_COOKIE >> 8)& 0xFF);
+    buffer[3] = (uint8_t)(MAGIC_COOKIE& 0xFF);
+
+    // OPT - message type
+    buffer[4] = dhcpMessageType;
+    buffer[5] = 0x01;
+    buffer[6] = messageType; //DHCP_REQUEST;
+
+    // OPT - client identifier
+    buffer[7] = dhcpClientIdentifier;
+    buffer[8] = 0x07;
+    buffer[9] = 0x01;
+    memcpy(buffer + 10, _dhcpMacAddr, 6);
+
+    // OPT - host name
+    buffer[16] = hostName;
+    buffer[17] = strlen(HOST_NAME) + 3; // length of hostname + last 3 bytes of mac address
+    strcpy((char*)&(buffer[18]), HOST_NAME);
+
+    buffer[24] = _dhcpMacAddr[3];
+    buffer[25] = _dhcpMacAddr[4];
+    buffer[26] = _dhcpMacAddr[5];
+
+    //put data in W5100 transmit buffer
+    _dhcpUdpSocket.write(buffer, 27);
+
+    if(messageType == DHCP_REQUEST)
+    {
+        buffer[0] = dhcpRequestedIPaddr;
+        buffer[1] = 0x04;
+        buffer[2] = _dhcpLocalIp[0];
+        buffer[3] = _dhcpLocalIp[1];
+        buffer[4] = _dhcpLocalIp[2];
+        buffer[5] = _dhcpLocalIp[3];
+
+        buffer[6] = dhcpServerIdentifier;
+        buffer[7] = 0x04;
+        buffer[8] = _dhcpDhcpServerIp[0];
+        buffer[9] = _dhcpDhcpServerIp[1];
+        buffer[10] = _dhcpDhcpServerIp[2];
+        buffer[11] = _dhcpDhcpServerIp[3];
+
+        //put data in W5100 transmit buffer
+        _dhcpUdpSocket.write(buffer, 12);
+    }
+    
+    buffer[0] = dhcpParamRequest;
+    buffer[1] = 0x06;
+    buffer[2] = subnetMask;
+    buffer[3] = routersOnSubnet;
+    buffer[4] = dns;
+    buffer[5] = domainName;
+    buffer[6] = dhcpT1value;
+    buffer[7] = dhcpT2value;
+    buffer[8] = endOption;
+    
+    //put data in W5100 transmit buffer
+    _dhcpUdpSocket.write(buffer, 9);
+
+    _dhcpUdpSocket.endPacket();
+}
+
+uint8_t DhcpClass::parseDHCPResponse(unsigned long responseTimeout, uint32_t& transactionId)
+{
+    uint8_t type = 0;
+    uint8_t opt_len = 0;
+     
+    unsigned long startTime = millis();
+
+    while(_dhcpUdpSocket.parsePacket() <= 0)
+    {
+        if((millis() - startTime) > responseTimeout)
+        {
+            return 255;
+        }
+        delay(50);
+    }
+    // start reading in the packet
+    RIP_MSG_FIXED fixedMsg;
+    _dhcpUdpSocket.read((uint8_t*)&fixedMsg, sizeof(RIP_MSG_FIXED));
+  
+    if(fixedMsg.op == DHCP_BOOTREPLY && _dhcpUdpSocket.remotePort() == DHCP_SERVER_PORT)
+    {
+        transactionId = ntohl(fixedMsg.xid);
+        if(memcmp(fixedMsg.chaddr, _dhcpMacAddr, 6) != 0 || (transactionId < _dhcpInitialTransactionId) || (transactionId > _dhcpTransactionId))
+        {
+            // Need to read the rest of the packet here regardless
+            _dhcpUdpSocket.flush();
+            return 0;
+        }
+
+        memcpy(_dhcpLocalIp, fixedMsg.yiaddr, 4);
+
+        // Skip to the option part
+        // Doing this a byte at a time so we don't have to put a big buffer
+        // on the stack (as we don't have lots of memory lying around)
+        for (int i =0; i < (240 - sizeof(RIP_MSG_FIXED)); i++)
+        {
+            _dhcpUdpSocket.read(); // we don't care about the returned byte
+        }
+
+        while (_dhcpUdpSocket.available() > 0) 
+        {
+            switch (_dhcpUdpSocket.read()) 
+            {
+                case endOption :
+                    break;
+                    
+                case padOption :
+                    break;
+                
+                case dhcpMessageType :
+                    opt_len = _dhcpUdpSocket.read();
+                    type = _dhcpUdpSocket.read();
+                    break;
+                
+                case subnetMask :
+                    opt_len = _dhcpUdpSocket.read();
+                    _dhcpUdpSocket.read(_dhcpSubnetMask, 4);
+                    break;
+                
+                case routersOnSubnet :
+                    opt_len = _dhcpUdpSocket.read();
+                    _dhcpUdpSocket.read(_dhcpGatewayIp, 4);
+                    break;
+                
+                case dns :
+                    opt_len = _dhcpUdpSocket.read();
+                    _dhcpUdpSocket.read(_dhcpDnsServerIp, 4);
+                    break;
+                
+                case dhcpServerIdentifier :
+                    opt_len = _dhcpUdpSocket.read();
+                    if( *((uint32_t*)_dhcpDhcpServerIp) == 0 || 
+                        IPAddress(_dhcpDhcpServerIp) == _dhcpUdpSocket.remoteIP() )
+                    {
+                        _dhcpUdpSocket.read(_dhcpDhcpServerIp, sizeof(_dhcpDhcpServerIp));
+                    }
+                    else
+                    {
+                        // Skip over the rest of this option
+                        while (opt_len--)
+                        {
+                            _dhcpUdpSocket.read();
+                        }
+                    }
+                    break;
+                
+                case dhcpIPaddrLeaseTime :
+                default :
+                    opt_len = _dhcpUdpSocket.read();
+                    // Skip over the rest of this option
+                    while (opt_len--)
+                    {
+                        _dhcpUdpSocket.read();
+                    }
+                    break;
+            }
+        }
+    }
+
+    // Need to skip to end of the packet regardless here
+    _dhcpUdpSocket.flush();
+
+    return type;
+}
+
+IPAddress DhcpClass::getLocalIp()
+{
+    return IPAddress(_dhcpLocalIp);
+}
+
+IPAddress DhcpClass::getSubnetMask()
+{
+    return IPAddress(_dhcpSubnetMask);
+}
+
+IPAddress DhcpClass::getGatewayIp()
+{
+    return IPAddress(_dhcpGatewayIp);
+}
+
+IPAddress DhcpClass::getDhcpServerIp()
+{
+    return IPAddress(_dhcpDhcpServerIp);
+}
+
+IPAddress DhcpClass::getDnsServerIp()
+{
+    return IPAddress(_dhcpDnsServerIp);
+}
+