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/*********************************************************************
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*
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* Dynamic Host Configuration Protocol (DHCP) Server
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* Module for Microchip TCP/IP Stack
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* -Provides automatic IP address, subnet mask, gateway address,
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* DNS server address, and other configuration parameters on DHCP
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* enabled networks.
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* -Reference: RFC 2131, 2132
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*
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*********************************************************************
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* FileName: DHCPs.c
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* Dependencies: UDP, ARP, Tick
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* Processor: PIC18, PIC24F, PIC24H, dsPIC30F, dsPIC33F
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* Complier: Microchip C18 v3.10 or higher
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* Microchip C30 v2.05 or higher
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* Company: Microchip Technology, Inc.
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*
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* Software License Agreement
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*
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* Copyright © 2002-2007 Microchip Technology Inc. All rights
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* reserved.
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*
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* Microchip licenses to you the right to use, modify, copy, and
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* distribute:
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* (i) the Software when embedded on a Microchip microcontroller or
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* digital signal controller product (“Device”) which is
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* integrated into Licensee’s product; or
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* (ii) ONLY the Software driver source files ENC28J60.c and
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* ENC28J60.h ported to a non-Microchip device used in
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* conjunction with a Microchip ethernet controller for the
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* sole purpose of interfacing with the ethernet controller.
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*
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* You should refer to the license agreement accompanying this
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* Software for additional information regarding your rights and
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* obligations.
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*
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* THE SOFTWARE AND DOCUMENTATION ARE PROVIDED “AS IS” WITHOUT
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* WARRANTY OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING WITHOUT
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* LIMITATION, ANY WARRANTY OF MERCHANTABILITY, FITNESS FOR A
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* PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT SHALL
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* MICROCHIP BE LIABLE FOR ANY INCIDENTAL, SPECIAL, INDIRECT OR
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* CONSEQUENTIAL DAMAGES, LOST PROFITS OR LOST DATA, COST OF
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* PROCUREMENT OF SUBSTITUTE GOODS, TECHNOLOGY OR SERVICES, ANY CLAIMS
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* BY THIRD PARTIES (INCLUDING BUT NOT LIMITED TO ANY DEFENSE
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* THEREOF), ANY CLAIMS FOR INDEMNITY OR CONTRIBUTION, OR OTHER
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* SIMILAR COSTS, WHETHER ASSERTED ON THE BASIS OF CONTRACT, TORT
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* (INCLUDING NEGLIGENCE), BREACH OF WARRANTY, OR OTHERWISE.
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*
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*
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* Author Date Comment
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*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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* Howard Schlunder 02/28/07 Original
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********************************************************************/
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#define __DHCPS_C
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#include "TCPIP Stack/TCPIP.h"
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#if defined(STACK_USE_DHCP_SERVER)
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#define DHCP_LEASE_DURATION 10ul // Seconds. This is extremely short so the client(s) won't use our IP address for long if we inadvertently give out a DHCP lease while there is another DHCP server on this network that we didn't know about.
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//#define DHCP_MAX_LEASES 2 // Not implemented
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// ClientMAC multicast bit is used to determine if a lease is given out or not.
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// Lease IP address is derived from index into DCB array
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typedef struct _DHCP_CONTROL_BLOCK
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{
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TICK LeaseExpires;
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MAC_ADDR ClientMAC;
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enum
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{
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LEASE_UNUSED = 0,
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LEASE_REQUESTED,
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LEASE_GRANTED
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} smLease;
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} DHCP_CONTROL_BLOCK;
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static UDP_SOCKET MySocket;
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static IP_ADDR DHCPNextLease;
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//static DHCP_CONTROL_BLOCK DCB[DHCP_MAX_LEASES]; // Not Implmented
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BOOL bDHCPServerEnabled = TRUE;
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static void DHCPReplyToDiscovery(BOOTP_HEADER *Header);
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static void DHCPReplyToRequest(BOOTP_HEADER *Header, BOOL bAccept);
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/*********************************************************************
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* Function: void DHCPServerTask(void)
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*
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* PreCondition: None
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*
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* Input: None
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*
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* Output: Processes DHCP requests and distributes IP
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* addresses
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*
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* Side Effects: None
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*
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* Overview: None
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*
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* Note: None
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********************************************************************/
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void DHCPServerTask(void)
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{
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BYTE i;
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BYTE Option, Len;
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BOOTP_HEADER BOOTPHeader;
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DWORD dw;
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BOOL bAccept;
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static enum
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{
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DHCP_OPEN_SOCKET,
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DHCP_LISTEN
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} smDHCPServer = DHCP_OPEN_SOCKET;
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#if defined(STACK_USE_DHCP_CLIENT)
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// Make sure we don't clobber anyone else's DHCP server
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if(DHCPFlags.bits.bDHCPServerDetected)
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return;
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#endif
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if(!bDHCPServerEnabled)
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return;
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switch(smDHCPServer)
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{
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case DHCP_OPEN_SOCKET:
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// Obtain a UDP socket to listen/transmit on
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MySocket = UDPOpen(DHCP_SERVER_PORT, NULL, DHCP_CLIENT_PORT);
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if(MySocket == INVALID_UDP_SOCKET)
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break;
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// Decide which address to lease out
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// Note that this needs to be changed if we are to
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// support more than one lease
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DHCPNextLease.Val = (AppConfig.MyIPAddr.Val & AppConfig.MyMask.Val) + 0x02000000;
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if(DHCPNextLease.v[3] == 255)
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DHCPNextLease.v[3] += 0x03000000;
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if(DHCPNextLease.v[3] == 0)
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DHCPNextLease.Val += 0x02000000;
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smDHCPServer++;
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case DHCP_LISTEN:
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// Check to see if a valid DHCP packet has arrived
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if(UDPIsGetReady(MySocket) < 241)
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break;
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// Retrieve the BOOTP header
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UDPGetArray((BYTE*)&BOOTPHeader, sizeof(BOOTPHeader));
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bAccept = (BOOTPHeader.ClientIP.Val == DHCPNextLease.Val) || (BOOTPHeader.ClientIP.Val == 0x00000000);
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// Validate first three fields
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if(BOOTPHeader.MessageType != 1u)
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break;
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if(BOOTPHeader.HardwareType != 1u)
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break;
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if(BOOTPHeader.HardwareLen != 6u)
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break;
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// Throw away 10 unused bytes of hardware address,
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// server host name, and boot file name -- unsupported/not needed.
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for(i = 0; i < 64+128+(16-sizeof(MAC_ADDR)); i++)
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UDPGet(&Option);
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// Obtain Magic Cookie and verify
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UDPGetArray((BYTE*)&dw, sizeof(DWORD));
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if(dw != 0x63538263ul)
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break;
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// Obtain options
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while(1)
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{
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// Get option type
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if(!UDPGet(&Option))
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break;
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if(Option == DHCP_END_OPTION)
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break;
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// Get option length
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UDPGet(&Len);
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// Process option
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switch(Option)
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{
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case DHCP_MESSAGE_TYPE:
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UDPGet(&i);
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switch(i)
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{
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case DHCP_DISCOVER_MESSAGE:
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DHCPReplyToDiscovery(&BOOTPHeader);
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break;
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case DHCP_REQUEST_MESSAGE:
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DHCPReplyToRequest(&BOOTPHeader, bAccept);
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break;
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// Need to handle these if supporting more than one DHCP lease
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case DHCP_RELEASE_MESSAGE:
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case DHCP_DECLINE_MESSAGE:
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break;
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}
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break;
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case DHCP_PARAM_REQUEST_IP_ADDRESS:
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if(Len == 4)
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{
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// Get the requested IP address and see if it is the one we have on offer.
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UDPGetArray((BYTE*)&dw, 4);
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bAccept = (dw == DHCPNextLease.Val);
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}
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break;
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case DHCP_END_OPTION:
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UDPDiscard();
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return;
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}
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// Remove any unprocessed bytes that we don't care about
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while(Len--)
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{
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UDPGet(&i);
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}
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}
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UDPDiscard();
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break;
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}
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}
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static void DHCPReplyToDiscovery(BOOTP_HEADER *Header)
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{
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BYTE i;
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// Set the correct socket to active and ensure that
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// enough space is available to generate the DHCP response
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if(UDPIsPutReady(MySocket) < 300)
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return;
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// Begin putting the BOOTP Header and DHCP options
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UDPPut(BOOT_REPLY); // Message Type: 2 (BOOTP Reply)
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// Reply with the same Hardware Type, Hardware Address Length, Hops, and Transaction ID fields
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UDPPutArray((BYTE*)&(Header->HardwareType), 7);
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UDPPut(0x00); // Seconds Elapsed: 0 (Not used)
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UDPPut(0x00); // Seconds Elapsed: 0 (Not used)
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UDPPutArray((BYTE*)&(Header->BootpFlags), sizeof(Header->BootpFlags));
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UDPPut(0x00); // Your (client) IP Address: 0.0.0.0 (none yet assigned)
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UDPPut(0x00); // Your (client) IP Address: 0.0.0.0 (none yet assigned)
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UDPPut(0x00); // Your (client) IP Address: 0.0.0.0 (none yet assigned)
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UDPPut(0x00); // Your (client) IP Address: 0.0.0.0 (none yet assigned)
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UDPPutArray((BYTE*)&DHCPNextLease, sizeof(IP_ADDR)); // Lease IP address to give out
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UDPPut(0x00); // Next Server IP Address: 0.0.0.0 (not used)
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UDPPut(0x00); // Next Server IP Address: 0.0.0.0 (not used)
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UDPPut(0x00); // Next Server IP Address: 0.0.0.0 (not used)
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UDPPut(0x00); // Next Server IP Address: 0.0.0.0 (not used)
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UDPPut(0x00); // Relay Agent IP Address: 0.0.0.0 (not used)
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UDPPut(0x00); // Relay Agent IP Address: 0.0.0.0 (not used)
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UDPPut(0x00); // Relay Agent IP Address: 0.0.0.0 (not used)
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UDPPut(0x00); // Relay Agent IP Address: 0.0.0.0 (not used)
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UDPPutArray((BYTE*)&(Header->ClientMAC), sizeof(MAC_ADDR)); // Client MAC address: Same as given by client
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for(i = 0; i < 64+128+(16-sizeof(MAC_ADDR)); i++) // Remaining 10 bytes of client hardware address, server host name: Null string (not used)
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UDPPut(0x00); // Boot filename: Null string (not used)
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UDPPut(0x63); // Magic Cookie: 0x63538263
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UDPPut(0x82); // Magic Cookie: 0x63538263
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UDPPut(0x53); // Magic Cookie: 0x63538263
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UDPPut(0x63); // Magic Cookie: 0x63538263
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// Options: DHCP Offer
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UDPPut(DHCP_MESSAGE_TYPE);
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UDPPut(1);
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UDPPut(DHCP_OFFER_MESSAGE);
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// Option: Subnet Mask
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UDPPut(DHCP_SUBNET_MASK);
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UDPPut(sizeof(IP_ADDR));
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UDPPutArray((BYTE*)&AppConfig.MyMask, sizeof(IP_ADDR));
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// Option: Lease duration
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UDPPut(DHCP_IP_LEASE_TIME);
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UDPPut(4);
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UDPPut((DHCP_LEASE_DURATION>>24) & 0xFF);
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UDPPut((DHCP_LEASE_DURATION>>16) & 0xFF);
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UDPPut((DHCP_LEASE_DURATION>>8) & 0xFF);
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UDPPut((DHCP_LEASE_DURATION) & 0xFF);
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// Option: Server identifier
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UDPPut(DHCP_SERVER_IDENTIFIER);
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UDPPut(sizeof(IP_ADDR));
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UDPPutArray((BYTE*)&AppConfig.MyIPAddr, sizeof(IP_ADDR));
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// Option: Router/Gateway address
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UDPPut(DHCP_ROUTER);
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UDPPut(sizeof(IP_ADDR));
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UDPPutArray((BYTE*)&AppConfig.MyIPAddr, sizeof(IP_ADDR));
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// No more options, mark ending
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UDPPut(DHCP_END_OPTION);
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// Transmit the packet
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UDPFlush();
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}
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// TODO: Handle more than one DHCP lease
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static void DHCPReplyToRequest(BOOTP_HEADER *Header, BOOL bAccept)
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{
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BYTE i;
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// Set the correct socket to active and ensure that
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// enough space is available to generate the DHCP response
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if(UDPIsPutReady(MySocket) < 300)
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return;
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// Search through all remaining options and look for the Requested IP address field
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// Obtain options
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while(UDPIsGetReady(MySocket))
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{
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BYTE Option, Len;
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DWORD dw;
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// Get option type
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if(!UDPGet(&Option))
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break;
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if(Option == DHCP_END_OPTION)
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break;
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// Get option length
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UDPGet(&Len);
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// Process option
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if((Option == DHCP_PARAM_REQUEST_IP_ADDRESS) && (Len == 4))
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{
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// Get the requested IP address and see if it is the one we have on offer. If not, we should send back a NAK, but since there could be some other DHCP server offering this address, we'll just silently ignore this request.
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UDPGetArray((BYTE*)&dw, 4);
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if(dw != DHCPNextLease.Val)
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{
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bAccept = FALSE;
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}
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break;
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}
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// Remove the unprocessed bytes that we don't care about
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while(Len--)
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{
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UDPGet(&i);
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}
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}
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#if defined(STACK_USE_DHCP_CLIENT)
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// Someone is using our DHCP server, start using a static
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// IP address and update the bind count so it displays on
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// the LCD
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AppConfig.Flags.bInConfigMode = FALSE;
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DHCPBindCount++;
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#endif
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// Begin putting the BOOTP Header and DHCP options
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UDPPut(BOOT_REPLY); // Message Type: 2 (BOOTP Reply)
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// Reply with the same Hardware Type, Hardware Address Length, Hops, and Transaction ID fields
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UDPPutArray((BYTE*)&(Header->HardwareType), 7);
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UDPPut(0x00); // Seconds Elapsed: 0 (Not used)
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UDPPut(0x00); // Seconds Elapsed: 0 (Not used)
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UDPPutArray((BYTE*)&(Header->BootpFlags), sizeof(Header->BootpFlags));
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UDPPutArray((BYTE*)&(Header->ClientIP), sizeof(IP_ADDR));// Your (client) IP Address:
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UDPPutArray((BYTE*)&DHCPNextLease, sizeof(IP_ADDR)); // Lease IP address to give out
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UDPPut(0x00); // Next Server IP Address: 0.0.0.0 (not used)
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UDPPut(0x00); // Next Server IP Address: 0.0.0.0 (not used)
|
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UDPPut(0x00); // Next Server IP Address: 0.0.0.0 (not used)
|
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UDPPut(0x00); // Next Server IP Address: 0.0.0.0 (not used)
|
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UDPPut(0x00); // Relay Agent IP Address: 0.0.0.0 (not used)
|
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UDPPut(0x00); // Relay Agent IP Address: 0.0.0.0 (not used)
|
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UDPPut(0x00); // Relay Agent IP Address: 0.0.0.0 (not used)
|
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UDPPut(0x00); // Relay Agent IP Address: 0.0.0.0 (not used)
|
377 |
UDPPutArray((BYTE*)&(Header->ClientMAC), sizeof(MAC_ADDR)); // Client MAC address: Same as given by client
|
378 |
for(i = 0; i < 64+128+(16-sizeof(MAC_ADDR)); i++) // Remaining 10 bytes of client hardware address, server host name: Null string (not used)
|
379 |
UDPPut(0x00); // Boot filename: Null string (not used)
|
380 |
UDPPut(0x63); // Magic Cookie: 0x63538263
|
381 |
UDPPut(0x82); // Magic Cookie: 0x63538263
|
382 |
UDPPut(0x53); // Magic Cookie: 0x63538263
|
383 |
UDPPut(0x63); // Magic Cookie: 0x63538263
|
384 |
|
385 |
// Options: DHCP lease ACKnowledge
|
386 |
if(bAccept)
|
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{
|
388 |
UDPPut(DHCP_OPTION_ACK_MESSAGE);
|
389 |
UDPPut(1);
|
390 |
UDPPut(DHCP_ACK_MESSAGE);
|
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}
|
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else // Send a NACK
|
393 |
{
|
394 |
UDPPut(DHCP_OPTION_ACK_MESSAGE);
|
395 |
UDPPut(1);
|
396 |
UDPPut(DHCP_NAK_MESSAGE);
|
397 |
}
|
398 |
|
399 |
// Option: Lease duration
|
400 |
UDPPut(DHCP_IP_LEASE_TIME);
|
401 |
UDPPut(4);
|
402 |
UDPPut((DHCP_LEASE_DURATION>>24) & 0xFF);
|
403 |
UDPPut((DHCP_LEASE_DURATION>>16) & 0xFF);
|
404 |
UDPPut((DHCP_LEASE_DURATION>>8) & 0xFF);
|
405 |
UDPPut((DHCP_LEASE_DURATION) & 0xFF);
|
406 |
|
407 |
// Option: Server identifier
|
408 |
UDPPut(DHCP_SERVER_IDENTIFIER);
|
409 |
UDPPut(sizeof(IP_ADDR));
|
410 |
UDPPutArray((BYTE*)&AppConfig.MyIPAddr, sizeof(IP_ADDR));
|
411 |
|
412 |
// Option: Subnet Mask
|
413 |
UDPPut(DHCP_SUBNET_MASK);
|
414 |
UDPPut(sizeof(IP_ADDR));
|
415 |
UDPPutArray((BYTE*)&AppConfig.MyMask, sizeof(IP_ADDR));
|
416 |
|
417 |
// Option: Router/Gateway address
|
418 |
UDPPut(DHCP_ROUTER);
|
419 |
UDPPut(sizeof(IP_ADDR));
|
420 |
UDPPutArray((BYTE*)&AppConfig.MyIPAddr, sizeof(IP_ADDR));
|
421 |
|
422 |
// No more options, mark ending
|
423 |
UDPPut(DHCP_END_OPTION);
|
424 |
|
425 |
// Transmit the packet
|
426 |
UDPFlush();
|
427 |
}
|
428 |
|
429 |
#endif //#if defined(STACK_USE_DHCP_SERVER)
|