1
0
mirror of https://github.com/arduino/Arduino.git synced 2024-12-04 15:24:12 +01:00
Arduino/libraries/Ethernet/Dhcp.cpp

342 lines
9.9 KiB
C++
Raw Normal View History

// 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 "Arduino.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);
}