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/*
LUFA Library
Copyright (C) Dean Camera, 2010.
dean [at] fourwalledcubicle [dot] com
www.fourwalledcubicle.com
*/
/*
Copyright 2010 Dean Camera (dean [at] fourwalledcubicle [dot] com)
Permission to use, copy, modify, distribute, and sell this
software and its documentation for any purpose is hereby granted
without fee, provided that the above copyright notice appear in
all copies and that both that the copyright notice and this
permission notice and warranty disclaimer appear in supporting
documentation, and that the name of the author not be used in
advertising or publicity pertaining to distribution of the
software without specific, written prior permission.
The author disclaim all warranties with regard to this
software, including all implied warranties of merchantability
and fitness. In no event shall the author be liable for any
special, indirect or consequential damages or any damages
whatsoever resulting from loss of use, data or profits, whether
in an action of contract, negligence or other tortious action,
arising out of or in connection with the use or performance of
this software.
*/
/** \file
*
* DHCP Client Application. When connected to the uIP stack, this will retrieve IP configuration settings from the
* DHCP server on the network.
*/
#include "DHCPApp.h"
#if defined(ENABLE_DHCP)
/** Timer for managing the timeout period for a DHCP server to respond */
struct timer DHCPTimer;
/** Initialization function for the DHCP client. */
void DHCPApp_Init(void)
{
uip_udp_appstate_t* const AppState = &uip_udp_conn->appstate;
/* Create a new UDP connection to the DHCP server port for the DHCP solicitation */
uip_ipaddr_t DHCPServerIPAddress;
uip_ipaddr(&DHCPServerIPAddress, 255, 255, 255, 255);
AppState->Connection = uip_udp_new(&DHCPServerIPAddress, HTONS(DHCPC_SERVER_PORT));
/* If the connection was sucessfully created, bind it to the local DHCP client port */
if(AppState->Connection != NULL)
{
uip_udp_bind(AppState->Connection, HTONS(DHCPC_CLIENT_PORT));
AppState->CurrentState = DHCP_STATE_SendDiscover;
}
/* Set timeout period to half a second for a DHCP server to respond */
timer_set(&DHCPTimer, CLOCK_SECOND / 2);
}
/** uIP stack application callback for the DHCP client. This function must be called each time the TCP/IP stack
* needs a UDP packet to be processed.
*/
void DHCPApp_Callback(void)
{
uip_udp_appstate_t* const AppState = &uip_udp_conn->appstate;
DHCP_Header_t* const AppData = (DHCP_Header_t*)uip_appdata;
uint16_t AppDataSize = 0;
switch (AppState->CurrentState)
{
case DHCP_STATE_SendDiscover:
/* Clear all DHCP settings, reset client IP address */
memset(&AppState->DHCPOffer_Data, 0x00, sizeof(AppState->DHCPOffer_Data));
uip_sethostaddr(&AppState->DHCPOffer_Data.AllocatedIP);
/* Fill out the DHCP response header */
AppDataSize += DHCPApp_FillDHCPHeader(AppData, DHCP_DISCOVER, AppState);
/* Add the required DHCP options list to the packet */
uint8_t RequiredOptionList[] = {DHCP_OPTION_SUBNET_MASK, DHCP_OPTION_ROUTER, DHCP_OPTION_DNS_SERVER};
AppDataSize += DHCPApp_SetOption(AppData->Options, DHCP_OPTION_REQ_LIST, sizeof(RequiredOptionList),
RequiredOptionList);
/* Send the DHCP DISCOVER packet */
uip_send(AppData, AppDataSize);
/* Reset the timeout timer, progress to next state */
timer_reset(&DHCPTimer);
AppState->CurrentState = DHCP_STATE_WaitForResponse;
break;
case DHCP_STATE_WaitForResponse:
if (!(uip_newdata()))
{
/* Check if the DHCP timeout period has expired while waiting for a response */
if (timer_expired(&DHCPTimer))
AppState->CurrentState = DHCP_STATE_SendDiscover;
break;
}
uint8_t OfferResponse_MessageType;
if ((AppData->TransactionID == DHCP_TRANSACTION_ID) &&
DHCPApp_GetOption(AppData->Options, DHCP_OPTION_MSG_TYPE, &OfferResponse_MessageType) &&
(OfferResponse_MessageType == DHCP_OFFER))
{
/* Received a DHCP offer for an IP address, copy over values for later request */
memcpy(&AppState->DHCPOffer_Data.AllocatedIP, &AppData->YourIP, sizeof(uip_ipaddr_t));
DHCPApp_GetOption(AppData->Options, DHCP_OPTION_SUBNET_MASK, &AppState->DHCPOffer_Data.Netmask);
DHCPApp_GetOption(AppData->Options, DHCP_OPTION_ROUTER, &AppState->DHCPOffer_Data.GatewayIP);
DHCPApp_GetOption(AppData->Options, DHCP_OPTION_SERVER_ID, &AppState->DHCPOffer_Data.ServerIP);
timer_reset(&DHCPTimer);
AppState->CurrentState = DHCP_STATE_SendRequest;
}
break;
case DHCP_STATE_SendRequest:
/* Fill out the DHCP response header */
AppDataSize += DHCPApp_FillDHCPHeader(AppData, DHCP_REQUEST, AppState);
/* Add the DHCP REQUESTED IP ADDRESS option to the packet */
AppDataSize += DHCPApp_SetOption(AppData->Options, DHCP_OPTION_REQ_IPADDR, sizeof(uip_ipaddr_t),
&AppState->DHCPOffer_Data.AllocatedIP);
/* Add the DHCP SERVER IP ADDRESS option to the packet */
AppDataSize += DHCPApp_SetOption(AppData->Options, DHCP_OPTION_SERVER_ID, sizeof(uip_ipaddr_t),
&AppState->DHCPOffer_Data.ServerIP);
/* Send the DHCP REQUEST packet */
uip_send(AppData, AppDataSize);
/* Reset the timeout timer, progress to next state */
timer_reset(&DHCPTimer);
AppState->CurrentState = DHCP_STATE_WaitForACK;
break;
case DHCP_STATE_WaitForACK:
if (!(uip_newdata()))
{
/* Check if the DHCP timeout period has expired while waiting for a response */
if (timer_expired(&DHCPTimer))
AppState->CurrentState = DHCP_STATE_SendDiscover;
break;
}
uint8_t RequestResponse_MessageType;
if ((AppData->TransactionID == DHCP_TRANSACTION_ID) &&
DHCPApp_GetOption(AppData->Options, DHCP_OPTION_MSG_TYPE, &RequestResponse_MessageType) &&
(RequestResponse_MessageType == DHCP_ACK))
{
/* Set the new network parameters from the DHCP server */
uip_sethostaddr(&AppState->DHCPOffer_Data.AllocatedIP);
uip_setnetmask(&AppState->DHCPOffer_Data.Netmask);
uip_setdraddr(&AppState->DHCPOffer_Data.GatewayIP);
AppState->CurrentState = DHCP_STATE_AddressLeased;
}
break;
}
}
uint16_t DHCPApp_FillDHCPHeader(DHCP_Header_t* DHCPHeader, uint8_t DHCPMessageType, uip_udp_appstate_t* AppState)
{
/* Erase existing packet data so that we start will all 0x00 DHCP header data */
memset(DHCPHeader, 0, sizeof(DHCP_Header_t));
/* Fill out the DHCP packet header */
DHCPHeader->Operation = DHCP_OP_BOOTREQUEST;
DHCPHeader->HardwareType = DHCP_HTYPE_ETHERNET;
DHCPHeader->HardwareAddressLength = sizeof(MACAddress);
DHCPHeader->Hops = 0;
DHCPHeader->TransactionID = DHCP_TRANSACTION_ID;
DHCPHeader->ElapsedSeconds = 0;
DHCPHeader->Flags = HTONS(BOOTP_BROADCAST);
memcpy(&DHCPHeader->ClientIP, &uip_hostaddr, sizeof(uip_ipaddr_t));
memcpy(&DHCPHeader->YourIP, &AppState->DHCPOffer_Data.AllocatedIP, sizeof(uip_ipaddr_t));
memcpy(&DHCPHeader->NextServerIP, &AppState->DHCPOffer_Data.ServerIP, sizeof(uip_ipaddr_t));
memcpy(&DHCPHeader->ClientHardwareAddress, &MACAddress, sizeof(struct uip_eth_addr));
DHCPHeader->Cookie = DHCP_MAGIC_COOKIE;
/* Add a DHCP type and terminator options to the start of the DHCP options field */
DHCPHeader->Options[0] = DHCP_OPTION_MSG_TYPE;
DHCPHeader->Options[1] = 1;
DHCPHeader->Options[2] = DHCPMessageType;
DHCPHeader->Options[3] = DHCP_OPTION_END;
/* Calculate the total number of bytes added to the outgoing packet */
return (sizeof(DHCP_Header_t) + 4);
}
uint8_t DHCPApp_SetOption(uint8_t* DHCPOptionList, uint8_t Option, uint8_t DataLen, void* Source)
{
/* Skip through the DHCP options list until the terminator option is found */
while (*DHCPOptionList != DHCP_OPTION_END)
DHCPOptionList += (DHCPOptionList[1] + 2);
/* Overwrite the existing terminator with the new option, add a new terminator at the end of the list */
DHCPOptionList[0] = Option;
DHCPOptionList[1] = DataLen;
memcpy(&DHCPOptionList[2], Source, DataLen);
DHCPOptionList[2 + DataLen] = DHCP_OPTION_END;
/* Calculate the total number of bytes added to the outgoing packet */
return (2 + DataLen);
}
bool DHCPApp_GetOption(uint8_t* DHCPOptionList, uint8_t Option, void* Destination)
{
/* Look through the incomming DHCP packet's options list for the requested option */
while (*DHCPOptionList != DHCP_OPTION_END)
{
/* Check if the current DHCP option in the packet is the one requested */
if (DHCPOptionList[0] == Option)
{
/* Copy request option's data to the destination buffer */
memcpy(Destination, &DHCPOptionList[2], DHCPOptionList[1]);
/* Indicate that the requested option data was sucessfully retrieved */
return true;
}
/* Skip to next DHCP option in the options list */
DHCPOptionList += (DHCPOptionList[1] + 2);
}
/* Requested option not found in the incomming packet's DHCP options list */
return false;
}
#endif
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