// echo request
static TCPIP_MAC_PKT_ACK_RES _ICMPProcessEchoRequest(TCPIP_NET_IF* pNetIf, TCPIP_MAC_PACKET* pRxPkt, uint32_t destAdd, uint32_t srcAdd)
{
ICMP_HEADER *pTxHdr;
IPV4_PACKET *pTxPkt;
TCPIP_UINT16_VAL checksum;
uint8_t *pSrcData, *pDstData;
TCPIP_MAC_DATA_SEGMENT *pSrcSeg;
// allocate TX packet
pTxPkt = _ICMPAllocateTxPacketStruct(pRxPkt->totTransportLen);
if(pTxPkt != 0)
{ // succeeded
// copy the 1st segment payload
pSrcSeg = pRxPkt->pDSeg;
pSrcData = pRxPkt->pTransportLayer;
pDstData = pTxPkt->macPkt.pTransportLayer;
while(pSrcSeg)
{
memcpy(pDstData, pSrcData, pSrcSeg->segLen);
pDstData += pSrcSeg->segLen;
if((pSrcSeg = pSrcSeg->next) != 0)
{
pSrcData = pSrcSeg->segLoad;
}
}
// set the correct vType, vCode, and Checksum
pTxHdr = (ICMP_HEADER*)pTxPkt->macPkt.pTransportLayer;
pTxHdr->vType = ICMP_TYPE_ECHO_REPLY;
pTxHdr->vCode = ICMP_CODE_ECHO_REPLY;
checksum.Val = pTxHdr->wChecksum;
checksum.v[0] += 8; // Subtract 0x0800 from the checksum
if(checksum.v[0] < 8u)
{
checksum.v[1]++;
if(checksum.v[1] == 0u)
{
checksum.v[0]++;
}
}
pTxHdr->wChecksum = checksum.Val;
pTxPkt->srcAddress.Val = destAdd;
pTxPkt->destAddress.Val = srcAdd;
pTxPkt->netIfH = pNetIf;
pTxPkt->macPkt.pDSeg->segLen += pRxPkt->totTransportLen;
TCPIP_IPV4_PacketFormatTx(pTxPkt, IP_PROT_ICMP, pRxPkt->totTransportLen);
if(!TCPIP_IPV4_PacketTransmit(pTxPkt))
{
TCPIP_PKT_PacketFree(&pTxPkt->macPkt);
}
}
return TCPIP_MAC_PKT_ACK_RX_OK;
}
ICMP_ECHO_RESULT TCPIP_ICMP_EchoRequestSend (IPV4_ADDR * targetAddr, uint16_t sequenceNumber, uint16_t identifier)
{
IPV4_PACKET* pTxPkt;
ICMP_PACKET* pICMPPkt;
uint32_t payload = 0x44332211;
uint16_t pktSize = sizeof(ICMP_PACKET);
ICMP_ECHO_RESULT res;
while(true)
{
// allocate TX packet
pTxPkt = _ICMPAllocateTxPacketStruct(pktSize);
if(pTxPkt == 0)
{
res = ICMP_ECHO_ALLOC_ERROR;
break;
}
pICMPPkt = (ICMP_PACKET*)pTxPkt->macPkt.pTransportLayer;
pICMPPkt->vType = ICMP_TYPE_ECHO_REQUEST;
pICMPPkt->vCode = ICMP_CODE_ECHO_REQUEST;
pICMPPkt->wChecksum = 0x0000;
pICMPPkt->wIdentifier = identifier;
pICMPPkt->wSequenceNumber = sequenceNumber;
pICMPPkt->wData = payload;
pICMPPkt->wChecksum = TCPIP_Helper_CalcIPChecksum((uint8_t*)pICMPPkt, pktSize, 0);
pTxPkt->destAddress.Val = targetAddr->Val;
pTxPkt->netIfH = TCPIP_IPV4_SelectSourceInterface(0, targetAddr, &pTxPkt->srcAddress, false);
if(pTxPkt->netIfH == 0)
{ // could not find an route
res = ICMP_ECHO_ROUTE_ERROR;
break;
}
pTxPkt->macPkt.pDSeg->segLen += pktSize;
TCPIP_IPV4_PacketFormatTx(pTxPkt, IP_PROT_ICMP, pktSize);
if(!TCPIP_IPV4_PacketTransmit(pTxPkt))
{
res = ICMP_ECHO_TRANSMIT_ERROR;
break;
}
res = ICMP_ECHO_OK;
break;
}
if(res < 0 && pTxPkt != 0)
{
TCPIP_PKT_PacketFree(&pTxPkt->macPkt);
}
return res;
}
// echo request
static TCPIP_MAC_PKT_ACK_RES _ICMPProcessEchoRequest(TCPIP_NET_IF* pNetIf, TCPIP_MAC_PACKET* pRxPkt, uint32_t destAdd, uint32_t srcAdd)
{
ICMP_HEADER *pTxHdr;
IPV4_PACKET *pTxPkt;
TCPIP_UINT16_VAL checksum;
int16_t dataToCopy;
// allocate TX packet
dataToCopy = pRxPkt->totTransportLen;
pTxPkt = _ICMPAllocateTxPacketStruct(dataToCopy);
if(pTxPkt != 0)
{ // succeeded
uint8_t* pStartAdd = pRxPkt->pTransportLayer;
TCPIP_Helper_PacketCopy(pRxPkt, pTxPkt->macPkt.pTransportLayer, &pStartAdd, dataToCopy, true);
// set the correct vType, vCode, and Checksum
pTxHdr = (ICMP_HEADER*)pTxPkt->macPkt.pTransportLayer;
pTxHdr->vType = ICMP_TYPE_ECHO_REPLY;
pTxHdr->vCode = ICMP_CODE_ECHO_REPLY;
checksum.Val = pTxHdr->wChecksum;
checksum.v[0] += 8; // Subtract 0x0800 from the checksum
if(checksum.v[0] < 8u)
{
checksum.v[1]++;
if(checksum.v[1] == 0u)
{
checksum.v[0]++;
}
}
pTxHdr->wChecksum = checksum.Val;
pTxPkt->srcAddress.Val = destAdd;
pTxPkt->destAddress.Val = srcAdd;
pTxPkt->netIfH = pNetIf;
pTxPkt->macPkt.pDSeg->segLen += pRxPkt->totTransportLen;
TCPIP_IPV4_PacketFormatTx(pTxPkt, IP_PROT_ICMP, pRxPkt->totTransportLen);
if(!TCPIP_IPV4_PacketTransmit(pTxPkt))
{
TCPIP_PKT_PacketFree(&pTxPkt->macPkt);
}
}
return TCPIP_MAC_PKT_ACK_RX_OK;
}