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/*********************************************************************
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*
|
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* Dynamic Host Configuration Protocol (DHCP) Client
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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: DHCP.c
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* Dependencies: StackTsk.h
|
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* UDP.h
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* Processor: PIC18, PIC24F, PIC24H, dsPIC30F, dsPIC33F
|
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* Complier: Microchip C18 v3.02 or higher
|
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* Microchip C30 v2.01 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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* Nilesh Rajbharti 3/21/01 Original (Rev 1.0)
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* Nilesh Rajbharti 7/10/02 Explicitly initialized tempIPAddress
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* (Rev 2.11)
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* Nilesh Rajbharti 5/16/03 Increased DHCP_TIMEOUT to 2 seconds.
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* Nilesh Rajbharti 5/16/03 Fixed SM_DHCP_BROADCAST logic
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* where UDPPut was called before setting
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* active socket.
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* Robert Sloan 5/29/03 Improved DHCP State machine to handle
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* NAK and renew existing IP address.
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* Nilesh Rajbharti 8/15/03 Modified _DHCPRecieve() to check for
|
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* chaddr field before accpting the packet.
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* Fixed DHCPTask() where it would not
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* reply to first OFFER.
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* Nilesh Rajbharti 3/1/04 Used tickDiff in DHCPTask() "bind"
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* state to adjust for irregular TICK_SECOND
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* Without this logic, actual lease time count
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* down may be incorrect.
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* Howard Schlunder 5/11/06 Fixed tickDiff usage, reducing
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* accumulated timing error. Fixed DHCP
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* state machine requesting IP 0.0.0.0
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* after lease expiration.
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* Howard Schlunder 6/01/06 Added DHCPFlags.bits.bOfferReceived flag to
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* allow operation on networks with multiple
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* DHCP servers offering multiple addresses
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* Howard Schlunder 8/01/06 Added DNS server option to DHCP request,
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* untested Host Name option to DHCP request
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* Howard Schlunder 1/09/06 Fixed a DHCP renewal not renewing lease time bug
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* Howard Schlunder 3/16/07 Rewrote DHCP state machine
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********************************************************************/
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#define __DHCP_C
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#include "TCPIP Stack/TCPIP.h"
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84 |
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#if defined(STACK_USE_DHCP_CLIENT)
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#define DHCP_TIMEOUT (TICK)(2*TICK_SECOND)
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SM_DHCP smDHCPState = SM_DHCP_GET_SOCKET;
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DHCP_CLIENT_FLAGS DHCPFlags = { 0x00 };
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BYTE DHCPBindCount = 0;
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static UDP_SOCKET DHCPSocket = INVALID_UDP_SOCKET;
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static DWORD_VAL DHCPServerID;
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static DWORD_VAL DHCPLeaseTime;
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static IP_ADDR tempIPAddress;
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static IP_ADDR tempGateway;
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static IP_ADDR tempMask;
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#if defined(STACK_USE_DNS)
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static IP_ADDR tempDNS;
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static IP_ADDR tempDNS2;
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#endif
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//static BYTE tempHostName[16];
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static union
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{
|
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struct
|
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{
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char IPAddress:1;
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char Gateway:1;
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char Mask:1;
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char DNS:1;
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char DNS2:1;
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char HostName:1;
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} bits;
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BYTE Val;
|
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} ValidValues;
|
119 |
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120 |
|
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static BYTE _DHCPReceive(void);
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static void _DHCPSend(BYTE messageType);
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123 |
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124 |
|
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/*********************************************************************
|
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* Function: void DHCPReset(void)
|
127 |
*
|
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* PreCondition: None
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*
|
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* Input: None
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131 |
*
|
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* Output: None
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*
|
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* Side Effects: None
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*
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* Overview: Resets the DHCP client, giving up any lease,
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* knowledge of DHCP servers, etc.
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*
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* Note: None
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140 |
********************************************************************/
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141 |
void DHCPReset(void)
|
142 |
{
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143 |
// Do nothing if DHCP is disabled
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144 |
if(smDHCPState == SM_DHCP_DISABLED)
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return;
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146 |
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147 |
if(DHCPSocket != INVALID_UDP_SOCKET)
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smDHCPState = SM_DHCP_SEND_DISCOVERY;
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else
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smDHCPState = SM_DHCP_GET_SOCKET;
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151 |
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DHCPBindCount = 0;
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153 |
DHCPFlags.bits.bIsBound = FALSE;
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}
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155 |
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/*********************************************************************
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* Function: void DHCPTask(void)
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*
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* PreCondition: DHCPInit() is already called
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*
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* Input: None
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*
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* Output: None
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165 |
*
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* Side Effects: None
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*
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* Overview: Gets and generates DHCP messages to obtain a
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* lease and keep it from expiring
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*
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* Note: None
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172 |
********************************************************************/
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173 |
void DHCPTask(void)
|
174 |
{
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175 |
static TICK eventTime;
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176 |
|
177 |
switch(smDHCPState)
|
178 |
{
|
179 |
case SM_DHCP_DISABLED:
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180 |
if(DHCPSocket != INVALID_UDP_SOCKET)
|
181 |
{
|
182 |
UDPClose(DHCPSocket);
|
183 |
DHCPSocket = INVALID_UDP_SOCKET;
|
184 |
}
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185 |
break;
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186 |
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187 |
case SM_DHCP_GET_SOCKET:
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188 |
// Open a socket to send and receive broadcast messages on
|
189 |
DHCPSocket = UDPOpen(DHCP_CLIENT_PORT, NULL, DHCP_SERVER_PORT);
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190 |
if(DHCPSocket == INVALID_UDP_SOCKET)
|
191 |
break;
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192 |
|
193 |
smDHCPState = SM_DHCP_SEND_DISCOVERY;
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194 |
// No break
|
195 |
|
196 |
case SM_DHCP_SEND_DISCOVERY:
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197 |
if(UDPIsPutReady(DHCPSocket) < 258)
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198 |
break;
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199 |
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200 |
// Ensure that we transmit to the broadcast IP and MAC addresses
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201 |
// The UDP Socket remembers who it was last talking to
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202 |
memset((void*)&UDPSocketInfo[DHCPSocket].remoteNode, 0xFF, sizeof(UDPSocketInfo[DHCPSocket].remoteNode));
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203 |
|
204 |
// Assume default IP Lease time of 60 seconds.
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205 |
// This should be minimum possible to make sure that if
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206 |
// server did not specify lease time, we try again after this minimum time.
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207 |
DHCPLeaseTime.Val = 60;
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208 |
ValidValues.Val = 0x00;
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209 |
DHCPBindCount = 0;
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210 |
DHCPFlags.bits.bIsBound = FALSE;
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211 |
DHCPFlags.bits.bOfferReceived = FALSE;
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// Send the DHCP Discover broadcast
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_DHCPSend(DHCP_DISCOVER_MESSAGE);
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215 |
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// Start a timer and begin looking for a response
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eventTime = TickGet() + DHCP_TIMEOUT;
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smDHCPState = SM_DHCP_GET_OFFER;
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break;
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220 |
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221 |
case SM_DHCP_GET_OFFER:
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// Check to see if a packet has arrived
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223 |
if(UDPIsGetReady(DHCPSocket) < 250)
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{
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225 |
// Go back and transmit a new discovery if we didn't get an offer after 2 seconds
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226 |
if((LONG)(eventTime - TickGet()) <= (LONG)0)
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227 |
smDHCPState = SM_DHCP_SEND_DISCOVERY;
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break;
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229 |
}
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230 |
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231 |
// Let the DHCP server module know that there is a DHCP server
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232 |
// on this network
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233 |
DHCPFlags.bits.bDHCPServerDetected = TRUE;
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234 |
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// Check to see if we received an offer
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if(_DHCPReceive() != DHCP_OFFER_MESSAGE)
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break;
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238 |
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smDHCPState = SM_DHCP_SEND_REQUEST;
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// No break
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241 |
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242 |
case SM_DHCP_SEND_REQUEST:
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243 |
if(UDPIsPutReady(DHCPSocket) < 258)
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break;
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245 |
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246 |
// Send the DHCP request message
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_DHCPSend(DHCP_REQUEST_MESSAGE);
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248 |
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249 |
// Start a timer and begin looking for a response
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eventTime = TickGet() + DHCP_TIMEOUT;
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smDHCPState = SM_DHCP_GET_REQUEST_ACK;
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252 |
break;
|
253 |
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254 |
case SM_DHCP_GET_REQUEST_ACK:
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// Check to see if a packet has arrived
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256 |
if(UDPIsGetReady(DHCPSocket) < 250)
|
257 |
{
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258 |
// Go back and transmit a new discovery if we didn't get an ACK after 2 seconds
|
259 |
if((LONG)(eventTime - TickGet()) <= (LONG)0)
|
260 |
smDHCPState = SM_DHCP_SEND_DISCOVERY;
|
261 |
break;
|
262 |
}
|
263 |
|
264 |
// Check to see if we received an offer
|
265 |
switch(_DHCPReceive())
|
266 |
{
|
267 |
case DHCP_ACK_MESSAGE:
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268 |
eventTime = TickGet() + TICK_SECOND;
|
269 |
smDHCPState = SM_DHCP_BOUND;
|
270 |
|
271 |
DHCPFlags.bits.bIsBound = TRUE;
|
272 |
DHCPBindCount++;
|
273 |
if(ValidValues.bits.IPAddress)
|
274 |
AppConfig.MyIPAddr = tempIPAddress;
|
275 |
if(ValidValues.bits.Mask)
|
276 |
AppConfig.MyMask = tempMask;
|
277 |
if(ValidValues.bits.Gateway)
|
278 |
AppConfig.MyGateway = tempGateway;
|
279 |
#if defined(STACK_USE_DNS)
|
280 |
if(ValidValues.bits.DNS)
|
281 |
AppConfig.PrimaryDNSServer = tempDNS;
|
282 |
if(ValidValues.bits.DNS2)
|
283 |
AppConfig.SecondaryDNSServer = tempDNS2;
|
284 |
#endif
|
285 |
// if(ValidValues.bits.HostName)
|
286 |
// memcpy(AppConfig.NetBIOSName, (void*)tempHostName, sizeof(AppConfig.NetBIOSName));
|
287 |
|
288 |
break;
|
289 |
|
290 |
case DHCP_NAK_MESSAGE:
|
291 |
smDHCPState = SM_DHCP_SEND_DISCOVERY;
|
292 |
break;
|
293 |
}
|
294 |
break;
|
295 |
|
296 |
case SM_DHCP_BOUND:
|
297 |
if((LONG)(eventTime - TickGet()) >= (LONG)0)
|
298 |
break;
|
299 |
|
300 |
// Check to see if our lease has nearly expired and we must renew
|
301 |
eventTime += TICK_SECOND;
|
302 |
DHCPLeaseTime.Val--;
|
303 |
if(DHCPLeaseTime.Val)
|
304 |
break;
|
305 |
|
306 |
smDHCPState = SM_DHCP_SEND_RENEW;
|
307 |
// No break
|
308 |
|
309 |
case SM_DHCP_SEND_RENEW:
|
310 |
case SM_DHCP_SEND_RENEW2:
|
311 |
case SM_DHCP_SEND_RENEW3:
|
312 |
if(UDPIsPutReady(DHCPSocket) < 258)
|
313 |
break;
|
314 |
|
315 |
// Send the DHCP request message
|
316 |
_DHCPSend(DHCP_REQUEST_MESSAGE);
|
317 |
DHCPFlags.bits.bOfferReceived = FALSE;
|
318 |
|
319 |
// Start a timer and begin looking for a response
|
320 |
eventTime = TickGet() + DHCP_TIMEOUT;
|
321 |
smDHCPState++;
|
322 |
break;
|
323 |
|
324 |
case SM_DHCP_GET_RENEW_ACK:
|
325 |
case SM_DHCP_GET_RENEW_ACK2:
|
326 |
case SM_DHCP_GET_RENEW_ACK3:
|
327 |
// Check to see if a packet has arrived
|
328 |
if(UDPIsGetReady(DHCPSocket) < 250)
|
329 |
{
|
330 |
// Go back and transmit a new discovery if we didn't get an ACK after 2 seconds
|
331 |
if((LONG)(eventTime - TickGet()) <= (LONG)0)
|
332 |
{
|
333 |
if(++smDHCPState > SM_DHCP_GET_RENEW_ACK3)
|
334 |
smDHCPState = SM_DHCP_SEND_DISCOVERY;
|
335 |
}
|
336 |
break;
|
337 |
}
|
338 |
|
339 |
// Check to see if we received an offer
|
340 |
switch(_DHCPReceive())
|
341 |
{
|
342 |
case DHCP_ACK_MESSAGE:
|
343 |
eventTime = TickGet() + TICK_SECOND;
|
344 |
DHCPBindCount++;
|
345 |
smDHCPState = SM_DHCP_BOUND;
|
346 |
break;
|
347 |
|
348 |
case DHCP_NAK_MESSAGE:
|
349 |
smDHCPState = SM_DHCP_SEND_DISCOVERY;
|
350 |
break;
|
351 |
}
|
352 |
break;
|
353 |
}
|
354 |
}
|
355 |
|
356 |
|
357 |
|
358 |
/*********************************************************************
|
359 |
DHCP PACKET FORMAT AS PER RFC 1541
|
360 |
|
361 |
0 1 2 3
|
362 |
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
|
363 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
364 |
| op (1) | htype (1) | hlen (1) | hops (1) |
|
365 |
+---------------+---------------+---------------+---------------+
|
366 |
| xid (4) |
|
367 |
+-------------------------------+-------------------------------+
|
368 |
| secs (2) | flags (2) |
|
369 |
+-------------------------------+-------------------------------+
|
370 |
| ciaddr (4) |
|
371 |
+---------------------------------------------------------------+
|
372 |
| yiaddr (4) |
|
373 |
+---------------------------------------------------------------+
|
374 |
| siaddr (4) |
|
375 |
+---------------------------------------------------------------+
|
376 |
| giaddr (4) |
|
377 |
+---------------------------------------------------------------+
|
378 |
| |
|
379 |
| chaddr (16) |
|
380 |
| |
|
381 |
| |
|
382 |
+---------------------------------------------------------------+
|
383 |
| |
|
384 |
| sname (64) |
|
385 |
+---------------------------------------------------------------+
|
386 |
| |
|
387 |
| file (128) |
|
388 |
+---------------------------------------------------------------+
|
389 |
| |
|
390 |
| options (312) |
|
391 |
+---------------------------------------------------------------+
|
392 |
|
393 |
********************************************************************/
|
394 |
static BYTE _DHCPReceive(void)
|
395 |
{
|
396 |
BYTE v;
|
397 |
BYTE i, j;
|
398 |
BYTE type;
|
399 |
BOOL lbDone;
|
400 |
DWORD_VAL tempServerID;
|
401 |
|
402 |
|
403 |
// Assume unknown message until proven otherwise.
|
404 |
type = DHCP_UNKNOWN_MESSAGE;
|
405 |
|
406 |
UDPGet(&v); // op
|
407 |
|
408 |
// Make sure this is BOOT_REPLY.
|
409 |
if ( v == BOOT_REPLY )
|
410 |
{
|
411 |
// Discard htype, hlen, hops, xid, secs, flags, ciaddr.
|
412 |
for ( i = 0; i < 15u; i++ )
|
413 |
UDPGet(&v);
|
414 |
|
415 |
// Check to see if this is the first offer
|
416 |
if(DHCPFlags.bits.bOfferReceived)
|
417 |
{
|
418 |
// Discard offered IP address, we already have an offer
|
419 |
for ( i = 0; i < 4u; i++ )
|
420 |
UDPGet(&v);
|
421 |
}
|
422 |
else
|
423 |
{
|
424 |
// Save offered IP address until we know for sure that we have it.
|
425 |
UDPGetArray((BYTE*)&tempIPAddress, sizeof(tempIPAddress));
|
426 |
ValidValues.bits.IPAddress = 1;
|
427 |
}
|
428 |
|
429 |
// Ignore siaddr, giaddr
|
430 |
for ( i = 0; i < 8u; i++ )
|
431 |
UDPGet(&v);
|
432 |
|
433 |
// Check to see if chaddr (Client Hardware Address) belongs to us.
|
434 |
for ( i = 0; i < 6u; i++ )
|
435 |
{
|
436 |
UDPGet(&v);
|
437 |
if ( v != AppConfig.MyMACAddr.v[i])
|
438 |
goto UDPInvalid;
|
439 |
}
|
440 |
|
441 |
|
442 |
// Ignore part of chaddr, sname, file, magic cookie.
|
443 |
for ( i = 0; i < 206u; i++ )
|
444 |
UDPGet(&v);
|
445 |
|
446 |
lbDone = FALSE;
|
447 |
do
|
448 |
{
|
449 |
// Get the Option number
|
450 |
// Break out eventually in case if this is a malformed
|
451 |
// DHCP message, ie: missing DHCP_END_OPTION marker
|
452 |
if(!UDPGet(&v))
|
453 |
{
|
454 |
lbDone = TRUE;
|
455 |
break;
|
456 |
}
|
457 |
|
458 |
switch(v)
|
459 |
{
|
460 |
case DHCP_MESSAGE_TYPE:
|
461 |
UDPGet(&v); // Skip len
|
462 |
// Len must be 1.
|
463 |
if ( v == 1u )
|
464 |
{
|
465 |
UDPGet(&type); // Get type
|
466 |
|
467 |
// Throw away the packet if we know we don't need it (ie: another offer when we already have one)
|
468 |
if(DHCPFlags.bits.bOfferReceived && (type == DHCP_OFFER_MESSAGE))
|
469 |
{
|
470 |
goto UDPInvalid;
|
471 |
}
|
472 |
}
|
473 |
else
|
474 |
goto UDPInvalid;
|
475 |
break;
|
476 |
|
477 |
case DHCP_SUBNET_MASK:
|
478 |
UDPGet(&v); // Skip len
|
479 |
// Len must be 4.
|
480 |
if ( v == 4u )
|
481 |
{
|
482 |
// Check to see if this is the first offer
|
483 |
if(DHCPFlags.bits.bOfferReceived)
|
484 |
{
|
485 |
// Discard offered IP mask, we already have an offer
|
486 |
for ( i = 0; i < 4u; i++ )
|
487 |
UDPGet(&v);
|
488 |
}
|
489 |
else
|
490 |
{
|
491 |
UDPGetArray((BYTE*)&tempMask, sizeof(tempMask));
|
492 |
ValidValues.bits.Mask = 1;
|
493 |
}
|
494 |
}
|
495 |
else
|
496 |
goto UDPInvalid;
|
497 |
break;
|
498 |
|
499 |
case DHCP_ROUTER:
|
500 |
UDPGet(&j);
|
501 |
// Len must be >= 4.
|
502 |
if ( j >= 4u )
|
503 |
{
|
504 |
// Check to see if this is the first offer
|
505 |
if(DHCPFlags.bits.bOfferReceived)
|
506 |
{
|
507 |
// Discard offered Gateway address, we already have an offer
|
508 |
for ( i = 0; i < 4u; i++ )
|
509 |
UDPGet(&v);
|
510 |
}
|
511 |
else
|
512 |
{
|
513 |
UDPGetArray((BYTE*)&tempGateway, sizeof(tempGateway));
|
514 |
ValidValues.bits.Gateway = 1;
|
515 |
}
|
516 |
}
|
517 |
else
|
518 |
goto UDPInvalid;
|
519 |
|
520 |
// Discard any other router addresses.
|
521 |
j -= 4;
|
522 |
while(j--)
|
523 |
UDPGet(&v);
|
524 |
break;
|
525 |
|
526 |
#if defined(STACK_USE_DNS)
|
527 |
case DHCP_DNS:
|
528 |
UDPGet(&j);
|
529 |
// Len must be >= 4.
|
530 |
if(j < 4u)
|
531 |
goto UDPInvalid;
|
532 |
|
533 |
// Check to see if this is the first offer
|
534 |
if(!DHCPFlags.bits.bOfferReceived)
|
535 |
{
|
536 |
UDPGetArray((BYTE*)&tempDNS, sizeof(tempDNS));
|
537 |
ValidValues.bits.DNS = 1;
|
538 |
j -= 4;
|
539 |
}
|
540 |
|
541 |
// Len must be >= 4 for a secondary DNS server address
|
542 |
if(j >= 4u)
|
543 |
{
|
544 |
// Check to see if this is the first offer
|
545 |
if(!DHCPFlags.bits.bOfferReceived)
|
546 |
{
|
547 |
UDPGetArray((BYTE*)&tempDNS2, sizeof(tempDNS2));
|
548 |
ValidValues.bits.DNS2 = 1;
|
549 |
j -= 4;
|
550 |
}
|
551 |
}
|
552 |
|
553 |
// Discard any other DNS server addresses
|
554 |
while(j--)
|
555 |
UDPGet(&v);
|
556 |
break;
|
557 |
#endif
|
558 |
|
559 |
// case DHCP_HOST_NAME:
|
560 |
// UDPGet(&j);
|
561 |
// // Len must be >= 4.
|
562 |
// if(j < 1u)
|
563 |
// goto UDPInvalid;
|
564 |
//
|
565 |
// // Check to see if this is the first offer
|
566 |
// if(DHCPFlags.bits.bOfferReceived)
|
567 |
// {
|
568 |
// // Discard offered host name, we already have an offer
|
569 |
// while(j--)
|
570 |
// UDPGet(&v);
|
571 |
// }
|
572 |
// else
|
573 |
// {
|
574 |
// for(i = 0; j, i < sizeof(tempHostName); i++, j--)
|
575 |
// {
|
576 |
// UDPGet(&tempHostName[i]);
|
577 |
// }
|
578 |
// while(j--)
|
579 |
// {
|
580 |
// UDPGet(&v);
|
581 |
// }
|
582 |
// ValidValues.bits.HostName = 1;
|
583 |
// }
|
584 |
//
|
585 |
// break;
|
586 |
|
587 |
case DHCP_SERVER_IDENTIFIER:
|
588 |
UDPGet(&v); // Get len
|
589 |
// Len must be 4.
|
590 |
if ( v == 4u )
|
591 |
{
|
592 |
UDPGet(&tempServerID.v[3]); // Get the id
|
593 |
UDPGet(&tempServerID.v[2]);
|
594 |
UDPGet(&tempServerID.v[1]);
|
595 |
UDPGet(&tempServerID.v[0]);
|
596 |
}
|
597 |
else
|
598 |
goto UDPInvalid;
|
599 |
break;
|
600 |
|
601 |
case DHCP_END_OPTION:
|
602 |
lbDone = TRUE;
|
603 |
break;
|
604 |
|
605 |
case DHCP_IP_LEASE_TIME:
|
606 |
UDPGet(&v); // Get len
|
607 |
// Len must be 4.
|
608 |
if ( v == 4u )
|
609 |
{
|
610 |
// Check to see if this is the first offer
|
611 |
if(DHCPFlags.bits.bOfferReceived)
|
612 |
{
|
613 |
// Discard offered lease time, we already have an offer
|
614 |
for ( i = 0; i < 4u; i++ )
|
615 |
UDPGet(&v);
|
616 |
}
|
617 |
else
|
618 |
{
|
619 |
UDPGet(&DHCPLeaseTime.v[3]);
|
620 |
UDPGet(&DHCPLeaseTime.v[2]);
|
621 |
UDPGet(&DHCPLeaseTime.v[1]);
|
622 |
UDPGet(&DHCPLeaseTime.v[0]);
|
623 |
|
624 |
// In case if our clock is not as accurate as the remote
|
625 |
// DHCP server's clock, let's treat the lease time as only
|
626 |
// 96.875% of the value given
|
627 |
DHCPLeaseTime.Val -= DHCPLeaseTime.Val>>5;
|
628 |
}
|
629 |
}
|
630 |
else
|
631 |
goto UDPInvalid;
|
632 |
break;
|
633 |
|
634 |
default:
|
635 |
// Ignore all unsupport tags.
|
636 |
UDPGet(&j); // Get option len
|
637 |
while( j-- ) // Ignore option values
|
638 |
UDPGet(&v);
|
639 |
}
|
640 |
} while( !lbDone );
|
641 |
}
|
642 |
|
643 |
// If this is an OFFER message, remember current server id.
|
644 |
if ( type == DHCP_OFFER_MESSAGE )
|
645 |
{
|
646 |
DHCPServerID.Val = tempServerID.Val;
|
647 |
DHCPFlags.bits.bOfferReceived = TRUE;
|
648 |
}
|
649 |
else
|
650 |
{
|
651 |
// For other types of messages, make sure that received
|
652 |
// server id matches with our previous one.
|
653 |
if ( DHCPServerID.Val != tempServerID.Val )
|
654 |
type = DHCP_UNKNOWN_MESSAGE;
|
655 |
}
|
656 |
|
657 |
UDPDiscard(); // We are done with this packet
|
658 |
return type;
|
659 |
|
660 |
UDPInvalid:
|
661 |
UDPDiscard();
|
662 |
return DHCP_UNKNOWN_MESSAGE;
|
663 |
|
664 |
}
|
665 |
|
666 |
|
667 |
|
668 |
|
669 |
|
670 |
static void _DHCPSend(BYTE messageType)
|
671 |
{
|
672 |
BYTE i;
|
673 |
IP_ADDR MyIP;
|
674 |
|
675 |
|
676 |
UDPPut(BOOT_REQUEST); // op
|
677 |
UDPPut(BOOT_HW_TYPE); // htype
|
678 |
UDPPut(BOOT_LEN_OF_HW_TYPE); // hlen
|
679 |
UDPPut(0); // hops
|
680 |
UDPPut(0x12); // xid[0]
|
681 |
UDPPut(0x23); // xid[1]
|
682 |
UDPPut(0x34); // xid[2]
|
683 |
UDPPut(0x56); // xid[3]
|
684 |
UDPPut(0); // secs[0]
|
685 |
UDPPut(0); // secs[1]
|
686 |
UDPPut(0x80); // flags[0] with BF set
|
687 |
UDPPut(0); // flags[1]
|
688 |
|
689 |
// If this is DHCP REQUEST message, use previously allocated IP address.
|
690 |
#if 0
|
691 |
if ( messageType == DHCP_REQUEST_MESSAGE )
|
692 |
{
|
693 |
UDPPutArray((BYTE*)&tempIPAddress, sizeof(tempIPAddress));
|
694 |
}
|
695 |
else
|
696 |
#endif
|
697 |
{
|
698 |
UDPPut(0x00);
|
699 |
UDPPut(0x00);
|
700 |
UDPPut(0x00);
|
701 |
UDPPut(0x00);
|
702 |
}
|
703 |
|
704 |
// Set yiaddr, siaddr, giaddr as zeros,
|
705 |
for ( i = 0; i < 12u; i++ )
|
706 |
UDPPut(0x00);
|
707 |
|
708 |
// Load chaddr - Client hardware address.
|
709 |
UDPPutArray((BYTE*)&AppConfig.MyMACAddr, sizeof(AppConfig.MyMACAddr));
|
710 |
|
711 |
// Set chaddr[6..15], sname and file as zeros.
|
712 |
for ( i = 0; i < 202u; i++ )
|
713 |
UDPPut(0);
|
714 |
|
715 |
// Load magic cookie as per RFC 1533.
|
716 |
UDPPut(99);
|
717 |
UDPPut(130);
|
718 |
UDPPut(83);
|
719 |
UDPPut(99);
|
720 |
|
721 |
// Load message type.
|
722 |
UDPPut(DHCP_MESSAGE_TYPE);
|
723 |
UDPPut(DHCP_MESSAGE_TYPE_LEN);
|
724 |
UDPPut(messageType);
|
725 |
|
726 |
if(messageType == DHCP_DISCOVER_MESSAGE)
|
727 |
{
|
728 |
// Reset offered flag so we know to act upon the next valid offer
|
729 |
DHCPFlags.bits.bOfferReceived = FALSE;
|
730 |
}
|
731 |
|
732 |
|
733 |
if ( messageType != DHCP_DISCOVER_MESSAGE && tempIPAddress.Val != 0x0000u )
|
734 |
{
|
735 |
// DHCP REQUEST message may include server identifier,
|
736 |
// to identify the server we are talking to.
|
737 |
// DHCP ACK may include it too. To simplify logic,
|
738 |
// we will include server identifier in DHCP ACK message too.
|
739 |
// _DHCPReceive() would populate "serverID" when it
|
740 |
// receives DHCP OFFER message. We will simply use that
|
741 |
// when we are replying to server.
|
742 |
// If this is a renwal request, do not include server id.
|
743 |
UDPPut(DHCP_SERVER_IDENTIFIER);
|
744 |
UDPPut(DHCP_SERVER_IDENTIFIER_LEN);
|
745 |
UDPPut(DHCPServerID.v[3]);
|
746 |
UDPPut(DHCPServerID.v[2]);
|
747 |
UDPPut(DHCPServerID.v[1]);
|
748 |
UDPPut(DHCPServerID.v[0]);
|
749 |
}
|
750 |
|
751 |
// Load our interested parameters
|
752 |
// This is hardcoded list. If any new parameters are desired,
|
753 |
// new lines must be added here.
|
754 |
UDPPut(DHCP_PARAM_REQUEST_LIST);
|
755 |
UDPPut(DHCP_PARAM_REQUEST_LIST_LEN);
|
756 |
UDPPut(DHCP_SUBNET_MASK);
|
757 |
UDPPut(DHCP_ROUTER);
|
758 |
UDPPut(DHCP_DNS);
|
759 |
UDPPut(DHCP_HOST_NAME);
|
760 |
|
761 |
// Add requested IP address to DHCP Request Message
|
762 |
if ( messageType == DHCP_REQUEST_MESSAGE )
|
763 |
{
|
764 |
UDPPut(DHCP_PARAM_REQUEST_IP_ADDRESS);
|
765 |
UDPPut(DHCP_PARAM_REQUEST_IP_ADDRESS_LEN);
|
766 |
UDPPutArray((BYTE*)&tempIPAddress, DHCP_PARAM_REQUEST_IP_ADDRESS_LEN);
|
767 |
}
|
768 |
|
769 |
// Add any new paramter request here.
|
770 |
|
771 |
// End of Options.
|
772 |
UDPPut(DHCP_END_OPTION);
|
773 |
|
774 |
// Make sure we advirtise a 0.0.0.0 IP address so all DHCP servers will respond. If we have a static IP outside the DHCP server's scope, it may simply ignore discover messages.
|
775 |
MyIP.Val = AppConfig.MyIPAddr.Val;
|
776 |
AppConfig.MyIPAddr.Val = 0x00000000;
|
777 |
UDPFlush();
|
778 |
AppConfig.MyIPAddr.Val = MyIP.Val;
|
779 |
|
780 |
}
|
781 |
|
782 |
|
783 |
#endif //#if defined(STACK_USE_DHCP_CLIENT)
|