/** Decodes an Ethernet frame header and prints its contents to through the USART in a human readable format.
*
* \param[in] InDataStart Pointer to the start of an Ethernet frame of data
*/
void DecodeEthernetFrameHeader(void* InDataStart)
{
#if !defined(NO_DECODE_ETHERNET)
Ethernet_Frame_Header_t* FrameHeader = (Ethernet_Frame_Header_t*)InDataStart;
printf_P(PSTR("\r\n"));
printf_P(PSTR(" ETHERNET\r\n"));
printf_P(PSTR(" + Frame Size: %u\r\n"), FrameINData->FrameLength);
if (!(MAC_COMPARE(&FrameHeader->Destination, &ServerMACAddress)) &&
!(MAC_COMPARE(&FrameHeader->Destination, &BroadcastMACAddress)))
{
printf_P(PSTR(" + NOT ADDRESSED TO DEVICE\r\n"));
return;
}
printf_P(PSTR(" + MAC Source : %02X:%02X:%02X:%02X:%02X:%02X\r\n"), FrameHeader->Source.Octets[0],
FrameHeader->Source.Octets[1],
FrameHeader->Source.Octets[2],
FrameHeader->Source.Octets[3],
FrameHeader->Source.Octets[4],
FrameHeader->Source.Octets[5]);
printf_P(PSTR(" + MAC Dest: %02X:%02X:%02X:%02X:%02X:%02X\r\n"), FrameHeader->Destination.Octets[0],
FrameHeader->Destination.Octets[1],
FrameHeader->Destination.Octets[2],
FrameHeader->Destination.Octets[3],
FrameHeader->Destination.Octets[4],
FrameHeader->Destination.Octets[5]);
printf_P(PSTR(" + Protocol: 0x%04x\r\n"), SwapEndian_16(FrameHeader->EtherType));
#endif
}
/** Decodes an ARP header and prints its contents to through the USART in a human readable format.
*
* \param[in] InDataStart Pointer to the start of an ARP packet header
*/
void DecodeARPHeader(void* InDataStart)
{
#if !defined(NO_DECODE_ARP)
ARP_Header_t* ARPHeader = (ARP_Header_t*)InDataStart;
printf_P(PSTR(" \\\r\n ARP\r\n"));
if (!(IP_COMPARE(&ARPHeader->TPA, &ServerIPAddress)) &&
!(MAC_COMPARE(&ARPHeader->THA, &ServerMACAddress)))
{
printf_P(PSTR(" + NOT ADDRESSED TO DEVICE\r\n"));
return;
}
printf_P(PSTR(" + Protocol: %x\r\n"), SwapEndian_16(ARPHeader->ProtocolType));
printf_P(PSTR(" + Operation: %u\r\n"), SwapEndian_16(ARPHeader->Operation));
if (SwapEndian_16(ARPHeader->ProtocolType) == ETHERTYPE_IPV4)
{
printf_P(PSTR(" + SHA MAC: %02X:%02X:%02X:%02X:%02X:%02X\r\n"), ARPHeader->SHA.Octets[0],
ARPHeader->SHA.Octets[1],
ARPHeader->SHA.Octets[2],
ARPHeader->SHA.Octets[3],
ARPHeader->SHA.Octets[4],
ARPHeader->SHA.Octets[5]);
printf_P(PSTR(" + SPA IP: %u.%u.%u.%u\r\n"), ARPHeader->SPA.Octets[0],
ARPHeader->SPA.Octets[1],
ARPHeader->SPA.Octets[2],
ARPHeader->SPA.Octets[3]);
printf_P(PSTR(" + THA MAC: %02X:%02X:%02X:%02X:%02X:%02X\r\n"), ARPHeader->THA.Octets[0],
ARPHeader->THA.Octets[1],
ARPHeader->THA.Octets[2],
ARPHeader->THA.Octets[3],
ARPHeader->THA.Octets[4],
ARPHeader->THA.Octets[5]);
printf_P(PSTR(" + TPA IP: %u.%u.%u.%u\r\n"), ARPHeader->TPA.Octets[0],
ARPHeader->TPA.Octets[1],
ARPHeader->TPA.Octets[2],
ARPHeader->TPA.Octets[3]);
}
#endif
}
/** Processes an ARP packet inside an Ethernet frame, and writes the appropriate response
* to the output Ethernet frame if the host is requesting the IP or MAC address of the
* virtual server device on the network.
*
* \param[in] InDataStart Pointer to the start of the incoming packet's ARP header
* \param[out] OutDataStart Pointer to the start of the outgoing packet's ARP header
*
* \return The number of bytes written to the out Ethernet frame if any, NO_RESPONSE otherwise
*/
int16_t ARP_ProcessARPPacket(void* InDataStart,
void* OutDataStart)
{
DecodeARPHeader(InDataStart);
ARP_Header_t* ARPHeaderIN = (ARP_Header_t*)InDataStart;
ARP_Header_t* ARPHeaderOUT = (ARP_Header_t*)OutDataStart;
/* Ensure that the ARP request is a IPv4 request packet */
if ((SwapEndian_16(ARPHeaderIN->ProtocolType) == ETHERTYPE_IPV4) &&
(SwapEndian_16(ARPHeaderIN->Operation) == ARP_OPERATION_REQUEST))
{
/* If the ARP packet is requesting the MAC or IP of the virtual webserver, return the response */
if (IP_COMPARE(&ARPHeaderIN->TPA, &ServerIPAddress) ||
MAC_COMPARE(&ARPHeaderIN->THA, &ServerMACAddress))
{
/* Fill out the ARP response header */
ARPHeaderOUT->HardwareType = ARPHeaderIN->HardwareType;
ARPHeaderOUT->ProtocolType = ARPHeaderIN->ProtocolType;
ARPHeaderOUT->HLEN = ARPHeaderIN->HLEN;
ARPHeaderOUT->PLEN = ARPHeaderIN->PLEN;
ARPHeaderOUT->Operation = SwapEndian_16(ARP_OPERATION_REPLY);
/* Copy over the sender MAC/IP to the target fields for the response */
ARPHeaderOUT->THA = ARPHeaderIN->SHA;
ARPHeaderOUT->TPA = ARPHeaderIN->SPA;
/* Copy over the new sender MAC/IP - MAC and IP addresses of the virtual webserver */
ARPHeaderOUT->SHA = ServerMACAddress;
ARPHeaderOUT->SPA = ServerIPAddress;
/* Return the size of the response so far */
return sizeof(ARP_Header_t);
}
}
return NO_RESPONSE;
}
