Adding Ethernet.maintain() to update DHCP leases (Peter Magnusson)

returns:
    0: nothing happened
    1: renew failed
    2: renew success
    3: rebind fail
    4: rebind success

http://code.google.com/p/arduino/issues/detail?id=716
This commit is contained in:
David A. Mellis 2012-03-02 18:51:48 -05:00
parent a6eb9ea5eb
commit 9f3438c189
4 changed files with 193 additions and 25 deletions

View File

@ -11,13 +11,33 @@
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);
_dhcpLeaseTime=0;
_dhcpT1=0;
_dhcpT2=0;
_lastCheck=0;
_timeout = timeout;
_responseTimeout = responseTimeout;
// zero out _dhcpMacAddr
memset(_dhcpMacAddr, 0, 6);
reset_DHCP_lease();
memcpy((void*)_dhcpMacAddr, (void*)mac, 6);
_dhcp_state = STATE_DHCP_START;
return request_DHCP_lease();
}
void DhcpClass::reset_DHCP_lease(){
// zero out _dhcpSubnetMask, _dhcpGatewayIp, _dhcpLocalIp, _dhcpDhcpServerIp, _dhcpDnsServerIp
memset(_dhcpLocalIp, 0, 20);
}
//return:0 on error, 1 if request is sent and response is received
int DhcpClass::request_DHCP_lease(){
uint8_t messageType = 0;
// Pick an initial transaction ID
_dhcpTransactionId = random(1UL, 2000UL);
@ -35,55 +55,75 @@ int DhcpClass::beginWithDHCP(uint8_t *mac, unsigned long timeout, unsigned long
unsigned long startTime = millis();
while(dhcp_state != STATE_DHCP_LEASED)
while(_dhcp_state != STATE_DHCP_LEASED)
{
if(dhcp_state == STATE_DHCP_START)
if(_dhcp_state == STATE_DHCP_START)
{
_dhcpTransactionId++;
send_DHCP_MESSAGE(DHCP_DISCOVER, ((millis() - startTime) / 1000));
dhcp_state = STATE_DHCP_DISCOVER;
_dhcp_state = STATE_DHCP_DISCOVER;
}
else if(dhcp_state == STATE_DHCP_DISCOVER)
else if(_dhcp_state == STATE_DHCP_REREQUEST){
_dhcpTransactionId++;
send_DHCP_MESSAGE(DHCP_REQUEST, ((millis() - startTime)/1000));
_dhcp_state = STATE_DHCP_REQUEST;
}
else if(_dhcp_state == STATE_DHCP_DISCOVER)
{
uint32_t respId;
messageType = parseDHCPResponse(responseTimeout, 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;
_dhcp_state = STATE_DHCP_REQUEST;
}
}
else if(dhcp_state == STATE_DHCP_REQUEST)
else if(_dhcp_state == STATE_DHCP_REQUEST)
{
uint32_t respId;
messageType = parseDHCPResponse(responseTimeout, respId);
messageType = parseDHCPResponse(_responseTimeout, respId);
if(messageType == DHCP_ACK)
{
dhcp_state = STATE_DHCP_LEASED;
_dhcp_state = STATE_DHCP_LEASED;
result = 1;
//use default lease time if we didn't get it
if(_dhcpLeaseTime == 0){
_dhcpLeaseTime = DEFAULT_LEASE;
}
//calculate T1 & T2 if we didn't get it
if(_dhcpT1 == 0){
//T1 should be 50% of _dhcpLeaseTime
_dhcpT1 = _dhcpLeaseTime >> 1;
}
if(_dhcpT2 == 0){
//T2 should be 87.5% (7/8ths) of _dhcpLeaseTime
_dhcpT2 = _dhcpT1 << 1;
}
_renewInSec = _dhcpT1;
_rebindInSec = _dhcpT2;
}
else if(messageType == DHCP_NAK)
dhcp_state = STATE_DHCP_START;
_dhcp_state = STATE_DHCP_START;
}
if(messageType == 255)
{
messageType = 0;
dhcp_state = STATE_DHCP_START;
_dhcp_state = STATE_DHCP_START;
}
if(result != 1 && ((millis() - startTime) > timeout))
if(result != 1 && ((millis() - startTime) > _timeout))
break;
}
// We're done with the socket now
_dhcpUdpSocket.stop();
_dhcpTransactionId++;
return result;
}
@ -302,8 +342,26 @@ uint8_t DhcpClass::parseDHCPResponse(unsigned long responseTimeout, uint32_t& tr
}
}
break;
case dhcpT1value :
opt_len = _dhcpUdpSocket.read();
_dhcpUdpSocket.read((uint8_t*)&_dhcpT1, sizeof(_dhcpT1));
_dhcpT1 = ntohl(_dhcpT1);
break;
case dhcpT2value :
opt_len = _dhcpUdpSocket.read();
_dhcpUdpSocket.read((uint8_t*)&_dhcpT2, sizeof(_dhcpT2));
_dhcpT2 = ntohl(_dhcpT2);
break;
case dhcpIPaddrLeaseTime :
opt_len = _dhcpUdpSocket.read();
_dhcpUdpSocket.read((uint8_t*)&_dhcpLeaseTime, sizeof(_dhcpLeaseTime));
_dhcpLeaseTime = ntohl(_dhcpLeaseTime);
_renewInSec = _dhcpLeaseTime;
break;
default :
opt_len = _dhcpUdpSocket.read();
// Skip over the rest of this option
@ -322,6 +380,68 @@ uint8_t DhcpClass::parseDHCPResponse(unsigned long responseTimeout, uint32_t& tr
return type;
}
/*
returns:
0/DHCP_CHECK_NONE: nothing happened
1/DHCP_CHECK_RENEW_FAIL: renew failed
2/DHCP_CHECK_RENEW_OK: renew success
3/DHCP_CHECK_REBIND_FAIL: rebind fail
4/DHCP_CHECK_REBIND_OK: rebind success
*/
int DhcpClass::checkLease(){
//this uses a signed / unsigned trick to deal with millis overflow
unsigned long now = millis();
signed long snow = (long)now;
int rc=DHCP_CHECK_NONE;
if (_lastCheck != 0){
signed long factor;
//calc how many ms past the timeout we are
factor = snow - (long)_secTimeout;
//if on or passed the timeout, reduce the counters
if ( factor >= 0 ){
//next timeout should be now plus 1000 ms minus parts of second in factor
_secTimeout = snow + 1000 - factor % 1000;
//how many seconds late are we, minimum 1
factor = factor / 1000 +1;
//reduce the counters by that mouch
//if we can assume that the cycle time (factor) is fairly constant
//and if the remainder is less than cycle time * 2
//do it early instead of late
if(_renewInSec < factor*2 )
_renewInSec = 0;
else
_renewInSec -= factor;
if(_rebindInSec < factor*2 )
_rebindInSec = 0;
else
_rebindInSec -= factor;
}
//if we have a lease but should renew, do it
if (_dhcp_state == STATE_DHCP_LEASED && _renewInSec <=0){
_dhcp_state = STATE_DHCP_REREQUEST;
rc = 1 + request_DHCP_lease();
}
//if we have a lease or is renewing but should bind, do it
if( (_dhcp_state == STATE_DHCP_LEASED || _dhcp_state == STATE_DHCP_START) && _rebindInSec <=0){
//this should basically restart completely
_dhcp_state = STATE_DHCP_START;
reset_DHCP_lease();
rc = 3 + request_DHCP_lease();
}
}
else{
_secTimeout = snow + 1000;
}
_lastCheck = now;
return rc;
}
IPAddress DhcpClass::getLocalIp()
{
return IPAddress(_dhcpLocalIp);

View File

@ -45,6 +45,13 @@
#define MAX_DHCP_OPT 16
#define HOST_NAME "WIZnet"
#define DEFAULT_LEASE (900) //default lease time in seconds
#define DHCP_CHECK_NONE (0)
#define DHCP_CHECK_RENEW_FAIL (1)
#define DHCP_CHECK_RENEW_OK (2)
#define DHCP_CHECK_REBIND_FAIL (3)
#define DHCP_CHECK_REBIND_OK (4)
enum
{
@ -139,8 +146,19 @@ private:
uint8_t _dhcpGatewayIp[4];
uint8_t _dhcpDhcpServerIp[4];
uint8_t _dhcpDnsServerIp[4];
uint32_t _dhcpLeaseTime;
uint32_t _dhcpT1, _dhcpT2;
signed long _renewInSec;
signed long _rebindInSec;
signed long _lastCheck;
unsigned long _timeout;
unsigned long _responseTimeout;
unsigned long _secTimeout;
uint8_t _dhcp_state;
EthernetUDP _dhcpUdpSocket;
int request_DHCP_lease();
void reset_DHCP_lease();
void presend_DHCP();
void send_DHCP_MESSAGE(uint8_t, uint16_t);
void printByte(char *, uint8_t);
@ -154,6 +172,7 @@ public:
IPAddress getDnsServerIp();
int beginWithDHCP(uint8_t *, unsigned long timeout = 60000, unsigned long responseTimeout = 4000);
int checkLease();
};
#endif

View File

@ -10,7 +10,8 @@ uint16_t EthernetClass::_server_port[MAX_SOCK_NUM] = {
int EthernetClass::begin(uint8_t *mac_address)
{
DhcpClass dhcp;
_dhcp = new DhcpClass();
// Initialise the basic info
W5100.init();
@ -18,15 +19,15 @@ int EthernetClass::begin(uint8_t *mac_address)
W5100.setIPAddress(IPAddress(0,0,0,0).raw_address());
// Now try to get our config info from a DHCP server
int ret = dhcp.beginWithDHCP(mac_address);
int ret = _dhcp->beginWithDHCP(mac_address);
if(ret == 1)
{
// We've successfully found a DHCP server and got our configuration info, so set things
// accordingly
W5100.setIPAddress(dhcp.getLocalIp().raw_address());
W5100.setGatewayIp(dhcp.getGatewayIp().raw_address());
W5100.setSubnetMask(dhcp.getSubnetMask().raw_address());
_dnsServerAddress = dhcp.getDnsServerIp();
W5100.setIPAddress(_dhcp->getLocalIp().raw_address());
W5100.setGatewayIp(_dhcp->getGatewayIp().raw_address());
W5100.setSubnetMask(_dhcp->getSubnetMask().raw_address());
_dnsServerAddress = _dhcp->getDnsServerIp();
}
return ret;
@ -66,6 +67,31 @@ void EthernetClass::begin(uint8_t *mac, IPAddress local_ip, IPAddress dns_server
_dnsServerAddress = dns_server;
}
int EthernetClass::maintain(){
int rc = DHCP_CHECK_NONE;
if(_dhcp != NULL){
//we have a pointer to dhcp, use it
rc = _dhcp->checkLease();
switch ( rc ){
case DHCP_CHECK_NONE:
//nothing done
break;
case DHCP_CHECK_RENEW_OK:
case DHCP_CHECK_REBIND_OK:
//we might have got a new IP.
W5100.setIPAddress(_dhcp->getLocalIp().raw_address());
W5100.setGatewayIp(_dhcp->getGatewayIp().raw_address());
W5100.setSubnetMask(_dhcp->getSubnetMask().raw_address());
_dnsServerAddress = _dhcp->getDnsServerIp();
break;
default:
//this is actually a error, it will retry though
break;
}
}
return rc;
}
IPAddress EthernetClass::localIP()
{
IPAddress ret;

View File

@ -6,12 +6,14 @@
#include "IPAddress.h"
#include "EthernetClient.h"
#include "EthernetServer.h"
#include "Dhcp.h"
#define MAX_SOCK_NUM 4
class EthernetClass {
private:
IPAddress _dnsServerAddress;
DhcpClass* _dhcp;
public:
static uint8_t _state[MAX_SOCK_NUM];
static uint16_t _server_port[MAX_SOCK_NUM];
@ -23,6 +25,7 @@ public:
void begin(uint8_t *mac_address, IPAddress local_ip, IPAddress dns_server);
void begin(uint8_t *mac_address, IPAddress local_ip, IPAddress dns_server, IPAddress gateway);
void begin(uint8_t *mac_address, IPAddress local_ip, IPAddress dns_server, IPAddress gateway, IPAddress subnet);
int maintain();
IPAddress localIP();
IPAddress subnetMask();