/*********************************************************************
*
* ICMP Module for Microchip TCP/IP Stack
*
*********************************************************************
* FileName: ICMP.c
* Dependencies: ICMP.h
* string.h
* StackTsk.h
* Helpers.h
* IP.h
* MAC.h
* Processor: PIC18, PIC24F, PIC24H, dsPIC30F, dsPIC33F
* Complier: Microchip C18 v3.02 or higher
* Microchip C30 v2.01 or higher
* Company: Microchip Technology, Inc.
*
* Software License Agreement
*
* This software is owned by Microchip Technology Inc. ("Microchip")
* and is supplied to you for use exclusively as described in the
* associated software agreement. This software is protected by
* software and other intellectual property laws. Any use in
* violation of the software license may subject the user to criminal
* sanctions as well as civil liability. Copyright 2006 Microchip
* Technology Inc. All rights reserved.
*
* This software is provided "AS IS." MICROCHIP DISCLAIMS ALL
* WARRANTIES, EXPRESS, IMPLIED, STATUTORY OR OTHERWISE, NOT LIMITED
* TO MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND
* INFRINGEMENT. Microchip shall in no event be liable for special,
* incidental, or consequential damages.
*
*
* Author Date Comment
*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
* Nilesh Rajbharti 4/30/01 Original (Rev 1.0)
* Nilesh Rajbharti 2/9/02 Cleanup
* Nilesh Rajbharti 5/22/02 Rev 2.0 (See version.log for detail)
* Howard Schlunder 9/9/04 Added ENC28J60 DMA checksum support
* Howard Schlunder 1/5/06 Increased DMA checksum efficiency
********************************************************************/
#include <string.h>
#include "..\Include\StackTsk.h"
#include "..\Include\Helpers.h"
#include "..\Include\ICMP.h"
#include "..\Include\IP.h"
#include "..\Include\MAC.h"
#if defined(STACK_USE_ICMP)
// ICMP packet definition
typedef struct _ICMP_PACKET
{
BYTE Type;
BYTE Code;
WORD Checksum;
WORD Identifier;
WORD SequenceNumber;
BYTE Data[MAX_ICMP_DATA];
} ICMP_PACKET;
#define ICMP_HEADER_SIZE (sizeof(ICMP_PACKET) - MAX_ICMP_DATA)
static void SwapICMPPacket(ICMP_PACKET* p);
/*********************************************************************
* Function: BOOL ICMPGet(ICMP_CODE *code,
* BYTE *data,
* BYTE *len,
* WORD *id,
* WORD *seq)
*
* PreCondition: MAC buffer contains ICMP type packet.
*
* Input: code - Buffer to hold ICMP code value
* data - Buffer to hold ICMP data
* len - Buffer to hold ICMP data length
* id - Buffer to hold ICMP id
* seq - Buffer to hold ICMP seq
*
* Output: TRUE if valid ICMP packet was received
* FALSE otherwise.
*
* Side Effects: None
*
* Overview: None
*
* Note: None
********************************************************************/
BOOL ICMPGet(ICMP_CODE *code,
BYTE *data,
BYTE *len,
WORD *id,
WORD *seq)
{
ICMP_PACKET packet;
WORD CalcChecksum;
WORD ReceivedChecksum;
#if defined(NON_MCHP_MAC)
WORD checksums[2];
#endif
// Obtain the ICMP Header
MACGetArray((BYTE*)&packet, ICMP_HEADER_SIZE);
#if !defined(NON_MCHP_MAC)
// Calculate the checksum using the Microchip MAC's DMA module
// The checksum data includes the precomputed checksum in the
// header, so a valid packet will always have a checksum of
// 0x0000 if the packet is not disturbed.
ReceivedChecksum = 0x0000;
CalcChecksum = MACCalcRxChecksum(0+sizeof(IP_HEADER), *len);
#endif
// Obtain the ICMP data payload
*len -= ICMP_HEADER_SIZE;
MACGetArray(data, *len);
#if defined(NON_MCHP_MAC)
// Calculte the checksum in local memory without hardware help
ReceivedChecksum = packet.Checksum;
packet.Checksum = 0;
checksums[0] = ~CalcIPChecksum((BYTE*)&packet, ICMP_HEADER_SIZE);
checksums[1] = ~CalcIPChecksum(data, *len);
CalcChecksum = CalcIPChecksum((BYTE*)checksums, 2 * sizeof(WORD));
#endif
SwapICMPPacket(&packet);
*code = packet.Type;
*id = packet.Identifier;
*seq = packet.SequenceNumber;
return ( CalcChecksum == ReceivedChecksum );
}
/*********************************************************************
* Function: void ICMPPut(NODE_INFO *remote,
* ICMP_CODE code,
* BYTE *data,
* BYTE len,
* WORD id,
* WORD seq)
*
* PreCondition: ICMPIsTxReady() == TRUE
*
* Input: remote - Remote node info
* code - ICMP_ECHO_REPLY or ICMP_ECHO_REQUEST
* data - Data bytes
* len - Number of bytes to send
* id - ICMP identifier
* seq - ICMP sequence number
*
* Output: None
*
* Side Effects: None
*
* Note: A ICMP packet is created and put on MAC.
*
********************************************************************/
void ICMPPut(NODE_INFO *remote,
ICMP_CODE code,
BYTE *data,
BYTE len,
WORD id,
WORD seq)
{
ICMP_PACKET packet;
WORD ICMPLen;
BUFFER MyTxBuffer = MACGetTxBuffer(TRUE);
// Abort if there is no where in the Ethernet controller to
// store this packet.
if(MyTxBuffer == INVALID_BUFFER)
return;
IPSetTxBuffer(MyTxBuffer, 0);
ICMPLen = ICMP_HEADER_SIZE + (WORD)len;
packet.Code = 0;
packet.Type = code;
packet.Checksum = 0;
packet.Identifier = id;
packet.SequenceNumber = seq;
memcpy((void*)packet.
Data, (void*)data
, len
);
SwapICMPPacket(&packet);
#if defined(NON_MCHP_MAC)
packet.Checksum = CalcIPChecksum((BYTE*)&packet,
ICMPLen);
#endif
IPPutHeader(remote,
IP_PROT_ICMP,
(WORD)(ICMP_HEADER_SIZE + len));
IPPutArray((BYTE*)&packet, ICMPLen);
#if !defined(NON_MCHP_MAC)
// Calculate and write the ICMP checksum using the Microchip MAC's DMA
packet.Checksum = MACCalcTxChecksum(sizeof(IP_HEADER), ICMPLen);
IPSetTxBuffer(MyTxBuffer, 2);
MACPutArray((BYTE*)&packet.Checksum, 2);
#endif
MACFlush();
}
/*********************************************************************
* Function: void SwapICMPPacket(ICMP_PACKET* p)
*
* PreCondition: None
*
* Input: p - ICMP packet header
*
* Output: ICMP packet is swapped
*
* Side Effects: None
*
* Overview: None
*
* Note: None
********************************************************************/
static void SwapICMPPacket(ICMP_PACKET* p)
{
p->Identifier = swaps(p->Identifier);
p->SequenceNumber = swaps(p->SequenceNumber);
p->Checksum = swaps(p->Checksum);
}
#endif //#if defined(STACK_USE_ICMP)