error_t samv71EthSendPacket(NetInterface *interface,
const NetBuffer *buffer, size_t offset)
{
size_t length;
//Retrieve the length of the packet
length = netBufferGetLength(buffer) - offset;
//Check the frame length
if(length > SAMV71_ETH_TX_BUFFER_SIZE)
{
//The transmitter can accept another packet
osSetEvent(&interface->nicTxEvent);
//Report an error
return ERROR_INVALID_LENGTH;
}
//Make sure the current buffer is available for writing
if(!(txBufferDesc[txBufferIndex].status & GMAC_TX_USED))
return ERROR_FAILURE;
//Copy user data to the transmit buffer
netBufferRead(txBuffer[txBufferIndex], buffer, offset, length);
//Set the necessary flags in the descriptor entry
if(txBufferIndex < (SAMV71_ETH_TX_BUFFER_COUNT - 1))
{
//Write the status word
txBufferDesc[txBufferIndex].status =
GMAC_TX_LAST | (length & GMAC_TX_LENGTH);
//Point to the next buffer
txBufferIndex++;
}
else
{
//Write the status word
txBufferDesc[txBufferIndex].status = GMAC_TX_WRAP |
GMAC_TX_LAST | (length & GMAC_TX_LENGTH);
//Wrap around
txBufferIndex = 0;
}
//Data synchronization barrier
__DSB();
//Set the TSTART bit to initiate transmission
GMAC->GMAC_NCR |= GMAC_NCR_TSTART;
//Check whether the next buffer is available for writing
if(txBufferDesc[txBufferIndex].status & GMAC_TX_USED)
{
//The transmitter can accept another packet
osSetEvent(&interface->nicTxEvent);
}
//Successful processing
return NO_ERROR;
}
error_t rx63nEthSendPacket(NetInterface *interface,
const NetBuffer *buffer, size_t offset)
{
//Retrieve the length of the packet
size_t length = netBufferGetLength(buffer) - offset;
//Check the frame length
if(length > RX63N_ETH_TX_BUFFER_SIZE)
{
//The transmitter can accept another packet
osSetEvent(&interface->nicTxEvent);
//Report an error
return ERROR_INVALID_LENGTH;
}
//Make sure the current buffer is available for writing
if(txDmaDesc[txIndex].td0 & EDMAC_TD0_TACT)
return ERROR_FAILURE;
//Copy user data to the transmit buffer
netBufferRead(txBuffer[txIndex], buffer, offset, length);
//Write the number of bytes to send
txDmaDesc[txIndex].td1 = (length << 16) & EDMAC_TD1_TBL;
//Check current index
if(txIndex < (RX63N_ETH_TX_BUFFER_COUNT - 1))
{
//Give the ownership of the descriptor to the DMA engine
txDmaDesc[txIndex].td0 = EDMAC_TD0_TACT | EDMAC_TD0_TFP_SOF |
EDMAC_TD0_TFP_EOF | EDMAC_TD0_TWBI;
//Point to the next descriptor
txIndex++;
}
else
{
//Give the ownership of the descriptor to the DMA engine
txDmaDesc[txIndex].td0 = EDMAC_TD0_TACT | EDMAC_TD0_TDLE |
EDMAC_TD0_TFP_SOF | EDMAC_TD0_TFP_EOF | EDMAC_TD0_TWBI;
//Wrap around
txIndex = 0;
}
//Instruct the DMA to poll the transmit descriptor list
EDMAC.EDTRR.BIT.TR = 1;
//Check whether the next buffer is available for writing
if(!(txDmaDesc[txIndex].td0 & EDMAC_TD0_TACT))
{
//The transmitter can accept another packet
osSetEvent(&interface->nicTxEvent);
}
//Successful write operation
return NO_ERROR;
}
void nbnsProcessMessage(NetInterface *interface, const IpPseudoHeader *pseudoHeader,
const UdpHeader *udpHeader, const NetBuffer *buffer, size_t offset, void *params)
{
size_t length;
NbnsHeader *message;
//Make sure the NBNS message was received from an IPv4 peer
if(pseudoHeader->length != sizeof(Ipv4PseudoHeader))
return;
//Retrieve the length of the NBNS message
length = netBufferGetLength(buffer) - offset;
//Ensure the NBNS message is valid
if(length < sizeof(NbnsHeader))
return;
if(length > DNS_MESSAGE_MAX_SIZE)
return;
//Point to the NBNS message header
message = netBufferAt(buffer, offset);
//Sanity check
if(message == NULL)
return;
//Debug message
TRACE_INFO("NBNS message received (%" PRIuSIZE " bytes)...\r\n", length);
//Dump message
dnsDumpMessage((DnsHeader *) message, length);
//NBNS messages received with an opcode other than zero must be silently ignored
if(message->opcode != DNS_OPCODE_QUERY)
return;
//NBNS messages received with non-zero response codes must be silently ignored
if(message->rcode != DNS_RCODE_NO_ERROR)
return;
//NBNS query received?
if(!message->qr)
{
#if (NBNS_RESPONDER_SUPPORT == ENABLED)
//Process incoming NBNS query message
nbnsProcessQuery(interface, &pseudoHeader->ipv4Data,
udpHeader, message, length);
#endif
}
//NBNS response received?
else
{
#if (NBNS_CLIENT_SUPPORT == ENABLED)
//Process incoming NBNS response message
nbnsProcessResponse(interface, &pseudoHeader->ipv4Data,
udpHeader, message, length);
#endif
}
}
error_t dm9000SendPacket(NetInterface *interface,
const NetBuffer *buffer, size_t offset)
{
size_t i;
uint16_t *p;
//Point to the driver context
Dm9000Context *context = (Dm9000Context *) interface->nicContext;
//Retrieve the length of the packet
size_t length = netBufferGetLength(buffer) - offset;
//Check the frame length
if(length > 1536)
{
//The transmitter can accept another packet
osSetEvent(&interface->nicTxEvent);
//Report an error
return ERROR_INVALID_LENGTH;
}
//Copy user data
netBufferRead(txBuffer, buffer, offset, length);
//A dummy write is required before accessing FIFO
dm9000WriteReg(DM9000_REG_MWCMDX, 0);
//Select MWCMD register
DM9000_INDEX_REG = DM9000_REG_MWCMD;
//Point to the beginning of the buffer
p = (uint16_t *) txBuffer;
//Write data to the FIFO using 16-bit mode
for(i = length; i > 1; i -= 2)
DM9000_DATA_REG = *(p++);
//Odd number of bytes?
if(i > 0)
DM9000_DATA_REG = *((uint8_t *) p);
//Write the number of bytes to send
dm9000WriteReg(DM9000_REG_TXPLL, LSB(length));
dm9000WriteReg(DM9000_REG_TXPLH, MSB(length));
//Clear interrupt flag
dm9000WriteReg(DM9000_REG_ISR, ISR_PT);
//Start data transfer
dm9000WriteReg(DM9000_REG_TCR, TCR_TXREQ);
//The packet was successfully written to FIFO
context->queuedPackets++;
//Successful processing
return NO_ERROR;
}
error_t m2sxxxEthSendPacket(NetInterface *interface,
const NetBuffer *buffer, size_t offset)
{
//Retrieve the length of the packet
size_t length = netBufferGetLength(buffer) - offset;
//Check the frame length
if(length > M2SXXX_ETH_TX_BUFFER_SIZE)
{
//The transmitter can accept another packet
osSetEvent(&interface->nicTxEvent);
//Report an error
return ERROR_INVALID_LENGTH;
}
//Make sure the current buffer is available for writing
if(!(txCurDmaDesc->size & DMA_DESC_EMPTY_FLAG))
return ERROR_FAILURE;
//Copy user data to the transmit buffer
netBufferRead((uint8_t *) txCurDmaDesc->addr, buffer, offset, length);
//Set the packet length and give the ownership of the descriptor to the DMA
txCurDmaDesc->size = length & DMA_DESC_SIZE_MASK;
//Check whether DMA transfers are suspended
if(!(MAC->DMA_TX_CTRL & DMA_TX_CTRL_TX_EN))
{
//Set the start position in the ring buffer
MAC->DMA_TX_DESC = (uint32_t) txCurDmaDesc;
}
//Instruct the DMA controller to transfer the packet
MAC->DMA_TX_CTRL = DMA_TX_CTRL_TX_EN;
//Point to the next descriptor in the list
txCurDmaDesc = (M2sxxxTxDmaDesc *) txCurDmaDesc->next;
//Check whether the next buffer is available for writing
if(txCurDmaDesc->size & DMA_DESC_EMPTY_FLAG)
{
//The transmitter can accept another packet
osSetEvent(&interface->nicTxEvent);
}
//Data successfully written
return NO_ERROR;
}
error_t stm32f4x7EthSendPacket(NetInterface *interface,
const NetBuffer *buffer, size_t offset)
{
//Retrieve the length of the packet
size_t length = netBufferGetLength(buffer) - offset;
//Check the frame length
if(length > STM32F4X7_ETH_TX_BUFFER_SIZE)
{
//The transmitter can accept another packet
osSetEvent(&interface->nicTxEvent);
//Report an error
return ERROR_INVALID_LENGTH;
}
//Make sure the current buffer is available for writing
if(txCurDmaDesc->tdes0 & ETH_TDES0_OWN)
return ERROR_FAILURE;
//Copy user data to the transmit buffer
netBufferRead((uint8_t *) txCurDmaDesc->tdes2, buffer, offset, length);
//Write the number of bytes to send
txCurDmaDesc->tdes1 = length & ETH_TDES1_TBS1;
//Set LS and FS flags as the data fits in a single buffer
txCurDmaDesc->tdes0 |= ETH_TDES0_LS | ETH_TDES0_FS;
//Give the ownership of the descriptor to the DMA
txCurDmaDesc->tdes0 |= ETH_TDES0_OWN;
//Clear TBUS flag to resume processing
ETH->DMASR = ETH_DMASR_TBUS;
//Instruct the DMA to poll the transmit descriptor list
ETH->DMATPDR = 0;
//Point to the next descriptor in the list
txCurDmaDesc = (Stm32f4x7TxDmaDesc *) txCurDmaDesc->tdes3;
//Check whether the next buffer is available for writing
if(!(txCurDmaDesc->tdes0 & ETH_TDES0_OWN))
{
//The transmitter can accept another packet
osSetEvent(&interface->nicTxEvent);
}
//Data successfully written
return NO_ERROR;
}
error_t ipv4SendDatagram(NetInterface *interface, Ipv4PseudoHeader *pseudoHeader,
NetBuffer *buffer, size_t offset, uint8_t ttl)
{
error_t error;
size_t length;
uint16_t id;
//Retrieve the length of payload
length = netBufferGetLength(buffer) - offset;
//Check whether the TTL value is zero
if(ttl == 0)
{
//Use default Time-To-Live value
ttl = IPV4_DEFAULT_TTL;
}
//Identification field is primarily used to identify
//fragments of an original IP datagram
id = osAtomicInc16(&interface->ipv4Identification);
//If the payload length is smaller than the network
//interface MTU then no fragmentation is needed
if((length + sizeof(Ipv4Header)) <= interface->ipv4Config.mtu)
{
//Send data as is
error = ipv4SendPacket(interface,
pseudoHeader, id, 0, buffer, offset, ttl);
}
//If the payload length exceeds the network interface MTU
//then the device must fragment the data
else
{
#if (IPV4_FRAG_SUPPORT == ENABLED)
//Fragment IP datagram into smaller packets
error = ipv4FragmentDatagram(interface,
pseudoHeader, id, buffer, offset, ttl);
#else
//Fragmentation is not supported
error = ERROR_MESSAGE_TOO_LONG;
#endif
}
//Return status code
return error;
}
error_t a2fxxxm3EthSendPacket(NetInterface *interface,
const NetBuffer *buffer, size_t offset)
{
//Retrieve the length of the packet
size_t length = netBufferGetLength(buffer) - offset;
//Check the frame length
if(length > A2FXXXM3_ETH_TX_BUFFER_SIZE)
{
//The transmitter can accept another packet
osSetEvent(&interface->nicTxEvent);
//Report an error
return ERROR_INVALID_LENGTH;
}
//Make sure the current buffer is available for writing
if(txCurDmaDesc->tdes0 & TDES0_OWN)
return ERROR_FAILURE;
//Copy user data to the transmit buffer
netBufferRead((uint8_t *) txCurDmaDesc->tdes2, buffer, offset, length);
//Write the number of bytes to send
txCurDmaDesc->tdes1 = length & TDES1_TBS1_MASK;
//Set LS and FS flags as the data fits in a single buffer
txCurDmaDesc->tdes1 |= TDES1_IC | TDES1_LS | TDES1_FS | TDES1_TCH;
//Give the ownership of the descriptor to the DMA
txCurDmaDesc->tdes0 |= TDES0_OWN;
//Instruct the DMA to poll the transmit descriptor list
MAC->CSR1 = 1;
//Point to the next descriptor in the list
txCurDmaDesc = (A2fxxxm3TxDmaDesc *) txCurDmaDesc->tdes3;
//Check whether the next buffer is available for writing
if(!(txCurDmaDesc->tdes0 & TDES0_OWN))
{
//The transmitter can accept another packet
osSetEvent(&interface->nicTxEvent);
}
//Data successfully written
return NO_ERROR;
}
error_t wilc1000SendPacket(NetInterface *interface,
const NetBuffer *buffer, size_t offset)
{
int8_t status;
size_t length;
//Retrieve the length of the packet
length = netBufferGetLength(buffer) - offset;
//Check the frame length
if(length > WILC1000_TX_BUFFER_SIZE)
{
//The transmitter can accept another packet
osSetEvent(&interface->nicTxEvent);
//Report an error
return ERROR_INVALID_LENGTH;
}
//Copy user data to the transmit buffer
netBufferRead(txBuffer, buffer, offset, length);
//STA or AP mode?
if(interface == wilc1000StaInterface)
{
//Send packet
status = m2m_wifi_send_ethernet_pkt(txBuffer, length);
}
else
{
status = m2m_wifi_send_ethernet_pkt_ifc1(txBuffer, length);
}
//The transmitter can accept another packet
osSetEvent(&interface->nicTxEvent);
//Return status code
if(status == M2M_SUCCESS)
return NO_ERROR;
else
return ERROR_FAILURE;
}
error_t ipv4FragmentDatagram(NetInterface *interface, Ipv4PseudoHeader *pseudoHeader,
uint16_t id, const NetBuffer *payload, size_t payloadOffset, uint8_t timeToLive)
{
error_t error;
size_t offset;
size_t length;
size_t payloadLength;
size_t fragmentOffset;
size_t maxFragmentSize;
NetBuffer *fragment;
//Retrieve the length of the payload
payloadLength = netBufferGetLength(payload) - payloadOffset;
//Allocate a memory buffer to hold IP fragments
fragment = ipAllocBuffer(0, &fragmentOffset);
//Failed to allocate memory?
if(!fragment)
return ERROR_OUT_OF_MEMORY;
//Maximum payload size for fragmented packets
maxFragmentSize = interface->ipv4Config.mtu - sizeof(Ipv4Header);
//The size shall be a multiple of 8-byte blocks
maxFragmentSize -= (maxFragmentSize % 8);
//Split the payload into multiple IP fragments
for(offset = 0; offset < payloadLength; offset += length)
{
//Flush the contents of the fragment
error = netBufferSetLength(fragment, fragmentOffset);
//Sanity check
if(error) break;
//Process the last fragment?
if((payloadLength - offset) <= maxFragmentSize)
{
//Size of the current fragment
length = payloadLength - offset;
//Copy fragment data
netBufferConcat(fragment, payload, payloadOffset + offset, length);
//Do not set the MF flag for the last fragment
error = ipv4SendPacket(interface, pseudoHeader, id,
offset / 8, fragment, fragmentOffset, timeToLive);
}
else
{
//Size of the current fragment (must be a multiple of 8-byte blocks)
length = maxFragmentSize;
//Copy fragment data
netBufferConcat(fragment, payload, payloadOffset + offset, length);
//Fragmented packets must have the MF flag set
error = ipv4SendPacket(interface, pseudoHeader, id,
IPV4_FLAG_MF | (offset / 8), fragment, fragmentOffset, timeToLive);
}
//Failed to send current IP packet?
if(error) break;
}
//Free previously allocated memory
netBufferFree(fragment);
//Return status code
return error;
}
error_t udpSendDatagramEx(NetInterface *interface, uint16_t srcPort, const IpAddr *destIpAddr,
uint16_t destPort, NetBuffer *buffer, size_t offset, uint8_t ttl)
{
error_t error;
size_t length;
UdpHeader *header;
IpPseudoHeader pseudoHeader;
//Make room for the UDP header
offset -= sizeof(UdpHeader);
//Retrieve the length of the datagram
length = netBufferGetLength(buffer) - offset;
//Point to the UDP header
header = netBufferAt(buffer, offset);
//Sanity check
if(!header) return ERROR_FAILURE;
//Format UDP header
header->srcPort = htons(srcPort);
header->destPort = htons(destPort);
header->length = htons(length);
header->checksum = 0;
#if (IPV4_SUPPORT == ENABLED)
//Destination address is an IPv4 address?
if(destIpAddr->length == sizeof(Ipv4Addr))
{
Ipv4Addr srcIpAddr;
//Select the source IPv4 address and the relevant network interface
//to use when sending data to the specified destination host
error = ipv4SelectSourceAddr(&interface, destIpAddr->ipv4Addr, &srcIpAddr);
//Any error to report?
if(error) return error;
//Format IPv4 pseudo header
pseudoHeader.length = sizeof(Ipv4PseudoHeader);
pseudoHeader.ipv4Data.srcAddr = srcIpAddr;
pseudoHeader.ipv4Data.destAddr = destIpAddr->ipv4Addr;
pseudoHeader.ipv4Data.reserved = 0;
pseudoHeader.ipv4Data.protocol = IPV4_PROTOCOL_UDP;
pseudoHeader.ipv4Data.length = htons(length);
//Calculate UDP header checksum
header->checksum = ipCalcUpperLayerChecksumEx(&pseudoHeader.ipv4Data,
sizeof(Ipv4PseudoHeader), buffer, offset, length);
}
else
#endif
#if (IPV6_SUPPORT == ENABLED)
//Destination address is an IPv6 address?
if(destIpAddr->length == sizeof(Ipv6Addr))
{
//Select the source IPv6 address and the relevant network interface
//to use when sending data to the specified destination host
error = ipv6SelectSourceAddr(&interface,
&destIpAddr->ipv6Addr, &pseudoHeader.ipv6Data.srcAddr);
//Any error to report?
if(error) return error;
//Format IPv6 pseudo header
pseudoHeader.length = sizeof(Ipv6PseudoHeader);
pseudoHeader.ipv6Data.destAddr = destIpAddr->ipv6Addr;
pseudoHeader.ipv6Data.length = htonl(length);
pseudoHeader.ipv6Data.reserved = 0;
pseudoHeader.ipv6Data.nextHeader = IPV6_UDP_HEADER;
//Calculate UDP header checksum
header->checksum = ipCalcUpperLayerChecksumEx(&pseudoHeader.ipv6Data,
sizeof(Ipv6PseudoHeader), buffer, offset, length);
}
else
#endif
//Invalid destination address?
{
//An internal error has occurred
return ERROR_FAILURE;
}
//Debug message
TRACE_INFO("Sending UDP datagram (%" PRIuSIZE " bytes)\r\n", length);
//Dump UDP header contents for debugging purpose
udpDumpHeader(header);
//Send UDP datagram
return ipSendDatagram(interface, &pseudoHeader, buffer, offset, ttl);
}
error_t udpProcessDatagram(NetInterface *interface,
IpPseudoHeader *pseudoHeader, const NetBuffer *buffer, size_t offset)
{
error_t error;
uint_t i;
size_t length;
UdpHeader *header;
Socket *socket;
SocketQueueItem *queueItem;
NetBuffer *p;
//Retrieve the length of the UDP datagram
length = netBufferGetLength(buffer) - offset;
//Ensure the UDP header is valid
if(length < sizeof(UdpHeader))
{
//Debug message
TRACE_WARNING("UDP datagram length is invalid!\r\n");
//Report an error
return ERROR_INVALID_HEADER;
}
//Point to the UDP header
header = netBufferAt(buffer, offset);
//Sanity check
if(!header) return ERROR_FAILURE;
//Debug message
TRACE_INFO("UDP datagram received (%" PRIuSIZE " bytes)...\r\n", length);
//Dump UDP header contents for debugging purpose
udpDumpHeader(header);
//When UDP runs over IPv6, the checksum is mandatory
if(header->checksum || pseudoHeader->length == sizeof(Ipv6PseudoHeader))
{
//Verify UDP checksum
if(ipCalcUpperLayerChecksumEx(pseudoHeader->data,
pseudoHeader->length, buffer, offset, length) != 0xFFFF)
{
//Debug message
TRACE_WARNING("Wrong UDP header checksum!\r\n");
//Report an error
return ERROR_WRONG_CHECKSUM;
}
}
//Enter critical section
osAcquireMutex(&socketMutex);
//Loop through opened sockets
for(i = 0; i < SOCKET_MAX_COUNT; i++)
{
//Point to the current socket
socket = socketTable + i;
//UDP socket found?
if(socket->type != SOCKET_TYPE_DGRAM)
continue;
//Check whether the socket is bound to a particular interface
if(socket->interface && socket->interface != interface)
continue;
//Check destination port number
if(socket->localPort != ntohs(header->destPort))
continue;
//Source port number filtering
if(socket->remotePort && socket->remotePort != ntohs(header->srcPort))
continue;
#if (IPV4_SUPPORT == ENABLED)
//An IPv4 packet was received?
if(pseudoHeader->length == sizeof(Ipv4PseudoHeader))
{
//Destination IP address filtering
if(socket->localIpAddr.length)
{
//An IPv4 address is expected
if(socket->localIpAddr.length != sizeof(Ipv4Addr))
continue;
//Filter out non-matching addresses
if(socket->localIpAddr.ipv4Addr != pseudoHeader->ipv4Data.destAddr)
continue;
}
//Source IP address filtering
if(socket->remoteIpAddr.length)
{
//An IPv4 address is expected
if(socket->remoteIpAddr.length != sizeof(Ipv4Addr))
continue;
//Filter out non-matching addresses
if(socket->remoteIpAddr.ipv4Addr != pseudoHeader->ipv4Data.srcAddr)
continue;
}
}
else
#endif
#if (IPV6_SUPPORT == ENABLED)
//An IPv6 packet was received?
if(pseudoHeader->length == sizeof(Ipv6PseudoHeader))
{
//Destination IP address filtering
if(socket->localIpAddr.length)
{
//An IPv6 address is expected
if(socket->localIpAddr.length != sizeof(Ipv6Addr))
continue;
//Filter out non-matching addresses
if(!ipv6CompAddr(&socket->localIpAddr.ipv6Addr, &pseudoHeader->ipv6Data.destAddr))
continue;
}
//Source IP address filtering
if(socket->remoteIpAddr.length)
{
//An IPv6 address is expected
if(socket->remoteIpAddr.length != sizeof(Ipv6Addr))
continue;
//Filter out non-matching addresses
if(!ipv6CompAddr(&socket->remoteIpAddr.ipv6Addr, &pseudoHeader->ipv6Data.srcAddr))
continue;
}
}
else
#endif
//An invalid packet was received?
{
//This should never occur...
continue;
}
//The current socket meets all the criteria
break;
}
//Point to the payload
offset += sizeof(UdpHeader);
length -= sizeof(UdpHeader);
//No matching socket found?
if(i >= SOCKET_MAX_COUNT)
{
//Leave critical section
osReleaseMutex(&socketMutex);
//Invoke user callback, if any
error = udpInvokeRxCallback(interface, pseudoHeader, header, buffer, offset);
//Return status code
return error;
}
//Empty receive queue?
if(!socket->receiveQueue)
{
//Allocate a memory buffer to hold the data and the associated descriptor
p = netBufferAlloc(sizeof(SocketQueueItem) + length);
//Successful memory allocation?
if(p != NULL)
{
//Point to the newly created item
queueItem = netBufferAt(p, 0);
queueItem->buffer = p;
//Add the newly created item to the queue
socket->receiveQueue = queueItem;
}
else
{
//Memory allocation failed
queueItem = NULL;
}
}
else
{
//Point to the very first item
queueItem = socket->receiveQueue;
//Reach the last item in the receive queue
for(i = 1; queueItem->next; i++)
queueItem = queueItem->next;
//Make sure the receive queue is not full
if(i >= UDP_RX_QUEUE_SIZE)
{
//Leave critical section
osReleaseMutex(&socketMutex);
//Notify the calling function that the queue is full
return ERROR_RECEIVE_QUEUE_FULL;
}
//Allocate a memory buffer to hold the data and the associated descriptor
p = netBufferAlloc(sizeof(SocketQueueItem) + length);
//Successful memory allocation?
if(p != NULL)
{
//Add the newly created item to the queue
queueItem->next = netBufferAt(p, 0);
//Point to the newly created item
queueItem = queueItem->next;
queueItem->buffer = p;
}
else
{
//Memory allocation failed
queueItem = NULL;
}
}
//Failed to allocate memory?
if(!queueItem)
{
//Leave critical section
osReleaseMutex(&socketMutex);
//Return error code
return ERROR_OUT_OF_MEMORY;
}
//Initialize next field
queueItem->next = NULL;
//Record the source port number
queueItem->srcPort = ntohs(header->srcPort);
#if (IPV4_SUPPORT == ENABLED)
//IPv4 remote address?
if(pseudoHeader->length == sizeof(Ipv4PseudoHeader))
{
//Save the source IPv4 address
queueItem->srcIpAddr.length = sizeof(Ipv4Addr);
queueItem->srcIpAddr.ipv4Addr = pseudoHeader->ipv4Data.srcAddr;
//Save the destination IPv4 address
queueItem->destIpAddr.length = sizeof(Ipv4Addr);
queueItem->destIpAddr.ipv4Addr = pseudoHeader->ipv4Data.destAddr;
}
#endif
#if (IPV6_SUPPORT == ENABLED)
//IPv6 remote address?
if(pseudoHeader->length == sizeof(Ipv6PseudoHeader))
{
//Save the source IPv6 address
queueItem->srcIpAddr.length = sizeof(Ipv6Addr);
queueItem->srcIpAddr.ipv6Addr = pseudoHeader->ipv6Data.srcAddr;
//Save the destination IPv6 address
queueItem->destIpAddr.length = sizeof(Ipv6Addr);
queueItem->destIpAddr.ipv6Addr = pseudoHeader->ipv6Data.destAddr;
}
#endif
//Offset to the payload
queueItem->offset = sizeof(SocketQueueItem);
//Copy the payload
netBufferCopy(queueItem->buffer, queueItem->offset, buffer, offset, length);
//Notify user that data is available
udpUpdateEvents(socket);
//Leave critical section
osReleaseMutex(&socketMutex);
//Successful processing
return NO_ERROR;
}
error_t rawSocketProcessIpPacket(NetInterface *interface,
IpPseudoHeader *pseudoHeader, const NetBuffer *buffer, size_t offset)
{
uint_t i;
size_t length;
Socket *socket;
SocketQueueItem *queueItem;
NetBuffer *p;
//Retrieve the length of the raw IP packet
length = netBufferGetLength(buffer) - offset;
//Enter critical section
osAcquireMutex(&socketMutex);
//Loop through opened sockets
for(i = 0; i < SOCKET_MAX_COUNT; i++)
{
//Point to the current socket
socket = socketTable + i;
//Raw socket found?
if(socket->type != SOCKET_TYPE_RAW_IP)
continue;
//Check whether the socket is bound to a particular interface
if(socket->interface && socket->interface != interface)
continue;
#if (IPV4_SUPPORT == ENABLED)
//An IPv4 packet was received?
if(pseudoHeader->length == sizeof(Ipv4PseudoHeader))
{
//Check protocol field
if(socket->protocol != pseudoHeader->ipv4Data.protocol)
continue;
//Destination IP address filtering
if(socket->localIpAddr.length)
{
//An IPv4 address is expected
if(socket->localIpAddr.length != sizeof(Ipv4Addr))
continue;
//Filter out non-matching addresses
if(socket->localIpAddr.ipv4Addr != pseudoHeader->ipv4Data.destAddr)
continue;
}
//Source IP address filtering
if(socket->remoteIpAddr.length)
{
//An IPv4 address is expected
if(socket->remoteIpAddr.length != sizeof(Ipv4Addr))
continue;
//Filter out non-matching addresses
if(socket->remoteIpAddr.ipv4Addr != pseudoHeader->ipv4Data.srcAddr)
continue;
}
}
else
#endif
#if (IPV6_SUPPORT == ENABLED)
//An IPv6 packet was received?
if(pseudoHeader->length == sizeof(Ipv6PseudoHeader))
{
//Check protocol field
if(socket->protocol != pseudoHeader->ipv6Data.nextHeader)
continue;
//Destination IP address filtering
if(socket->localIpAddr.length)
{
//An IPv6 address is expected
if(socket->localIpAddr.length != sizeof(Ipv6Addr))
continue;
//Filter out non-matching addresses
if(!ipv6CompAddr(&socket->localIpAddr.ipv6Addr, &pseudoHeader->ipv6Data.destAddr))
continue;
}
//Source IP address filtering
if(socket->remoteIpAddr.length)
{
//An IPv6 address is expected
if(socket->remoteIpAddr.length != sizeof(Ipv6Addr))
continue;
//Filter out non-matching addresses
if(!ipv6CompAddr(&socket->remoteIpAddr.ipv6Addr, &pseudoHeader->ipv6Data.srcAddr))
continue;
}
}
else
#endif
//An invalid packet was received?
{
//This should never occur...
continue;
}
//The current socket meets all the criteria
break;
}
//Drop incoming packet if no matching socket was found
if(i >= SOCKET_MAX_COUNT)
{
//Leave critical section
osReleaseMutex(&socketMutex);
//Unreachable protocol...
return ERROR_PROTOCOL_UNREACHABLE;
}
//Empty receive queue?
if(!socket->receiveQueue)
{
//Allocate a memory buffer to hold the data and the associated descriptor
p = netBufferAlloc(sizeof(SocketQueueItem) + length);
//Successful memory allocation?
if(p != NULL)
{
//Point to the newly created item
queueItem = netBufferAt(p, 0);
queueItem->buffer = p;
//Add the newly created item to the queue
socket->receiveQueue = queueItem;
}
else
{
//Memory allocation failed
queueItem = NULL;
}
}
else
{
//Point to the very first item
queueItem = socket->receiveQueue;
//Reach the last item in the receive queue
for(i = 1; queueItem->next; i++)
queueItem = queueItem->next;
//Make sure the receive queue is not full
if(i >= RAW_SOCKET_RX_QUEUE_SIZE)
{
//Leave critical section
osReleaseMutex(&socketMutex);
//Notify the calling function that the queue is full
return ERROR_RECEIVE_QUEUE_FULL;
}
//Allocate a memory buffer to hold the data and the associated descriptor
p = netBufferAlloc(sizeof(SocketQueueItem) + length);
//Successful memory allocation?
if(p != NULL)
{
//Add the newly created item to the queue
queueItem->next = netBufferAt(p, 0);
//Point to the newly created item
queueItem = queueItem->next;
queueItem->buffer = p;
}
else
{
//Memory allocation failed
queueItem = NULL;
}
}
//Failed to allocate memory?
if(!queueItem)
{
//Leave critical section
osReleaseMutex(&socketMutex);
//Return error code
return ERROR_OUT_OF_MEMORY;
}
//Initialize next field
queueItem->next = NULL;
//Port number is unused
queueItem->srcPort = 0;
#if (IPV4_SUPPORT == ENABLED)
//IPv4 remote address?
if(pseudoHeader->length == sizeof(Ipv4PseudoHeader))
{
//Save the source IPv4 address
queueItem->srcIpAddr.length = sizeof(Ipv4Addr);
queueItem->srcIpAddr.ipv4Addr = pseudoHeader->ipv4Data.srcAddr;
//Save the destination IPv4 address
queueItem->destIpAddr.length = sizeof(Ipv4Addr);
queueItem->destIpAddr.ipv4Addr = pseudoHeader->ipv4Data.destAddr;
}
#endif
#if (IPV6_SUPPORT == ENABLED)
//IPv6 remote address?
if(pseudoHeader->length == sizeof(Ipv6PseudoHeader))
{
//Save the source IPv6 address
queueItem->srcIpAddr.length = sizeof(Ipv6Addr);
queueItem->srcIpAddr.ipv6Addr = pseudoHeader->ipv6Data.srcAddr;
//Save the destination IPv6 address
queueItem->destIpAddr.length = sizeof(Ipv6Addr);
queueItem->destIpAddr.ipv6Addr = pseudoHeader->ipv6Data.destAddr;
}
#endif
//Offset to the raw IP packet
queueItem->offset = sizeof(SocketQueueItem);
//Copy the raw data
netBufferCopy(queueItem->buffer, queueItem->offset, buffer, offset, length);
//Notify user that data is available
rawSocketUpdateEvents(socket);
//Leave critical section
osReleaseMutex(&socketMutex);
//Successful processing
return NO_ERROR;
}
void tcpProcessSegment(NetInterface *interface,
IpPseudoHeader *pseudoHeader, const NetBuffer *buffer, size_t offset)
{
uint_t i;
size_t length;
Socket *socket;
Socket *passiveSocket;
TcpHeader *segment;
//Total number of segments received, including those received in error
MIB2_INC_COUNTER32(mib2Base.tcpGroup.tcpInSegs, 1);
MIB2_INC_COUNTER64(mib2Base.tcpGroup.tcpHCInSegs, 1);
//A TCP implementation must silently discard an incoming
//segment that is addressed to a broadcast or multicast
//address (see RFC 1122 4.2.3.10)
#if (IPV4_SUPPORT == ENABLED)
if(pseudoHeader->length == sizeof(Ipv4PseudoHeader))
{
//Ensure the destination address is not a broadcast address
if(ipv4IsBroadcastAddr(interface, pseudoHeader->ipv4Data.destAddr))
return;
//Ensure the destination address is not a multicast address
if(ipv4IsMulticastAddr(pseudoHeader->ipv4Data.destAddr))
return;
}
else
#endif
#if (IPV6_SUPPORT == ENABLED)
if(pseudoHeader->length == sizeof(Ipv6PseudoHeader))
{
//Ensure the destination address is not a multicast address
if(ipv6IsMulticastAddr(&pseudoHeader->ipv6Data.destAddr))
return;
}
else
#endif
{
//This should never occur...
return;
}
//Retrieve the length of the TCP segment
length = netBufferGetLength(buffer) - offset;
//Point to the TCP header
segment = netBufferAt(buffer, offset);
//Sanity check
if(segment == NULL)
return;
//Ensure the TCP header is valid
if(length < sizeof(TcpHeader))
{
//Debug message
TRACE_WARNING("TCP segment length is invalid!\r\n");
//Total number of segments received in error
MIB2_INC_COUNTER32(mib2Base.tcpGroup.tcpInErrs, 1);
//Exit immediately
return;
}
//Check header length
if(segment->dataOffset < 5 || (segment->dataOffset * 4) > length)
{
//Debug message
TRACE_WARNING("TCP header length is invalid!\r\n");
//Total number of segments received in error
MIB2_INC_COUNTER32(mib2Base.tcpGroup.tcpInErrs, 1);
//Exit immediately
return;
}
//Verify TCP checksum
if(ipCalcUpperLayerChecksumEx(pseudoHeader->data,
pseudoHeader->length, buffer, offset, length) != 0x0000)
{
//Debug message
TRACE_WARNING("Wrong TCP header checksum!\r\n");
//Total number of segments received in error
MIB2_INC_COUNTER32(mib2Base.tcpGroup.tcpInErrs, 1);
//Exit immediately
return;
}
//No matching socket in the LISTEN state for the moment
passiveSocket = NULL;
//Look through opened sockets
for(i = 0; i < SOCKET_MAX_COUNT; i++)
{
//Point to the current socket
socket = socketTable + i;
//TCP socket found?
if(socket->type != SOCKET_TYPE_STREAM)
continue;
//Check whether the socket is bound to a particular interface
if(socket->interface && socket->interface != interface)
continue;
//Check destination port number
if(socket->localPort != ntohs(segment->destPort))
continue;
#if (IPV4_SUPPORT == ENABLED)
//An IPv4 packet was received?
if(pseudoHeader->length == sizeof(Ipv4PseudoHeader))
{
//Destination IP address filtering
if(socket->localIpAddr.length)
{
//An IPv4 address is expected
if(socket->localIpAddr.length != sizeof(Ipv4Addr))
continue;
//Filter out non-matching addresses
if(socket->localIpAddr.ipv4Addr != pseudoHeader->ipv4Data.destAddr)
continue;
}
//Source IP address filtering
if(socket->remoteIpAddr.length)
{
//An IPv4 address is expected
if(socket->remoteIpAddr.length != sizeof(Ipv4Addr))
continue;
//Filter out non-matching addresses
if(socket->remoteIpAddr.ipv4Addr != pseudoHeader->ipv4Data.srcAddr)
continue;
}
}
else
#endif
#if (IPV6_SUPPORT == ENABLED)
//An IPv6 packet was received?
if(pseudoHeader->length == sizeof(Ipv6PseudoHeader))
{
//Destination IP address filtering
if(socket->localIpAddr.length)
{
//An IPv6 address is expected
if(socket->localIpAddr.length != sizeof(Ipv6Addr))
continue;
//Filter out non-matching addresses
if(!ipv6CompAddr(&socket->localIpAddr.ipv6Addr, &pseudoHeader->ipv6Data.destAddr))
continue;
}
//Source IP address filtering
if(socket->remoteIpAddr.length)
{
//An IPv6 address is expected
if(socket->remoteIpAddr.length != sizeof(Ipv6Addr))
continue;
//Filter out non-matching addresses
if(!ipv6CompAddr(&socket->remoteIpAddr.ipv6Addr, &pseudoHeader->ipv6Data.srcAddr))
continue;
}
}
else
#endif
//An invalid packet was received?
{
//This should never occur...
continue;
}
//Keep track of the first matching socket in the LISTEN state
if(socket->state == TCP_STATE_LISTEN && !passiveSocket)
passiveSocket = socket;
//Source port filtering
if(socket->remotePort != ntohs(segment->srcPort))
continue;
//A matching socket has been found
break;
}
//If no matching socket has been found then try to
//use the first matching socket in the LISTEN state
if(i >= SOCKET_MAX_COUNT) socket = passiveSocket;
//Offset to the first data byte
offset += segment->dataOffset * 4;
//Calculate the length of the data
length -= segment->dataOffset * 4;
//Debug message
TRACE_DEBUG("%s: TCP segment received (%" PRIuSIZE " data bytes)...\r\n",
formatSystemTime(osGetSystemTime(), NULL), length);
//Dump TCP header contents for debugging purpose
if(!socket)
tcpDumpHeader(segment, length, 0, 0);
else
tcpDumpHeader(segment, length, socket->irs, socket->iss);
//Convert from network byte order to host byte order
segment->srcPort = ntohs(segment->srcPort);
segment->destPort = ntohs(segment->destPort);
segment->seqNum = ntohl(segment->seqNum);
segment->ackNum = ntohl(segment->ackNum);
segment->window = ntohs(segment->window);
segment->urgentPointer = ntohs(segment->urgentPointer);
//Specified port is unreachable?
if(!socket)
{
//An incoming segment not containing a RST causes
//a reset to be sent in response
if(!(segment->flags & TCP_FLAG_RST))
tcpSendResetSegment(interface, pseudoHeader, segment, length);
//Return immediately
return;
}
//Check current state
switch(socket->state)
{
//Process CLOSED state
case TCP_STATE_CLOSED:
//This is the default state that each connection starts in before
//the process of establishing it begins
tcpStateClosed(interface, pseudoHeader, segment, length);
break;
//Process LISTEN state
case TCP_STATE_LISTEN:
//A device (normally a server) is waiting to receive a synchronize (SYN)
//message from a client. It has not yet sent its own SYN message
tcpStateListen(socket, interface, pseudoHeader, segment, length);
break;
//Process SYN_SENT state
case TCP_STATE_SYN_SENT:
//The device (normally a client) has sent a synchronize (SYN) message and
//is waiting for a matching SYN from the other device (usually a server)
tcpStateSynSent(socket, segment, length);
break;
//Process SYN_RECEIVED state
case TCP_STATE_SYN_RECEIVED:
//The device has both received a SYN from its partner and sent its own SYN.
//It is now waiting for an ACK to its SYN to finish connection setup
tcpStateSynReceived(socket, segment, buffer, offset, length);
break;
//Process ESTABLISHED state
case TCP_STATE_ESTABLISHED:
//Data can be exchanged freely once both devices in the connection enter
//this state. This will continue until the connection is closed
tcpStateEstablished(socket, segment, buffer, offset, length);
break;
//Process CLOSE_WAIT state
case TCP_STATE_CLOSE_WAIT:
//The device has received a close request (FIN) from the other device. It
//must now wait for the application to acknowledge this request and
//generate a matching request
tcpStateCloseWait(socket, segment, length);
break;
//Process LAST_ACK state
case TCP_STATE_LAST_ACK:
//A device that has already received a close request and acknowledged it,
//has sent its own FIN and is waiting for an ACK to this request
tcpStateLastAck(socket, segment, length);
break;
//Process FIN_WAIT_1 state
case TCP_STATE_FIN_WAIT_1:
//A device in this state is waiting for an ACK for a FIN it has sent, or
//is waiting for a connection termination request from the other device
tcpStateFinWait1(socket, segment, buffer, offset, length);
break;
//Process FIN_WAIT_2 state
case TCP_STATE_FIN_WAIT_2:
//A device in this state has received an ACK for its request to terminate the
//connection and is now waiting for a matching FIN from the other device
tcpStateFinWait2(socket, segment, buffer, offset, length);
break;
//Process CLOSING state
case TCP_STATE_CLOSING:
//The device has received a FIN from the other device and sent an ACK for
//it, but not yet received an ACK for its own FIN message
tcpStateClosing(socket, segment, length);
break;
//Process TIME_WAIT state
case TCP_STATE_TIME_WAIT:
//The device has now received a FIN from the other device and acknowledged
//it, and sent its own FIN and received an ACK for it. We are done, except
//for waiting to ensure the ACK is received and prevent potential overlap
//with new connections
tcpStateTimeWait(socket, segment, length);
break;
//Invalid state...
default:
//Back to the CLOSED state
tcpChangeState(socket, TCP_STATE_CLOSED);
//Silently discard incoming packet
break;
}
}
void ipv4ProcessDatagram(NetInterface *interface, const NetBuffer *buffer)
{
error_t error;
size_t offset;
size_t length;
Ipv4Header *header;
IpPseudoHeader pseudoHeader;
//Retrieve the length of the IPv4 datagram
length = netBufferGetLength(buffer);
//Point to the IPv4 header
header = netBufferAt(buffer, 0);
//Sanity check
if(!header) return;
//Debug message
TRACE_INFO("IPv4 datagram received (%" PRIuSIZE " bytes)...\r\n", length);
//Dump IP header contents for debugging purpose
ipv4DumpHeader(header);
//Get the offset to the payload
offset = header->headerLength * 4;
//Compute the length of the payload
length -= header->headerLength * 4;
//Form the IPv4 pseudo header
pseudoHeader.length = sizeof(Ipv4PseudoHeader);
pseudoHeader.ipv4Data.srcAddr = header->srcAddr;
pseudoHeader.ipv4Data.destAddr = header->destAddr;
pseudoHeader.ipv4Data.reserved = 0;
pseudoHeader.ipv4Data.protocol = header->protocol;
pseudoHeader.ipv4Data.length = htons(length);
#if defined(IPV4_DATAGRAM_FORWARD_HOOK)
IPV4_DATAGRAM_FORWARD_HOOK(interface, &pseudoHeader, buffer, offset);
#endif
//Check the protocol field
switch(header->protocol)
{
//ICMP protocol?
case IPV4_PROTOCOL_ICMP:
//Process incoming ICMP message
icmpProcessMessage(interface, header->srcAddr, buffer, offset);
#if (RAW_SOCKET_SUPPORT == ENABLED)
//Allow raw sockets to process ICMP messages
rawSocketProcessIpPacket(interface, &pseudoHeader, buffer, offset);
#endif
//No error to report
error = NO_ERROR;
//Continue processing
break;
#if (IGMP_SUPPORT == ENABLED)
//IGMP protocol?
case IPV4_PROTOCOL_IGMP:
//Process incoming IGMP message
igmpProcessMessage(interface, buffer, offset);
#if (RAW_SOCKET_SUPPORT == ENABLED)
//Allow raw sockets to process IGMP messages
rawSocketProcessIpPacket(interface, &pseudoHeader, buffer, offset);
#endif
//No error to report
error = NO_ERROR;
//Continue processing
break;
#endif
#if (TCP_SUPPORT == ENABLED)
//TCP protocol?
case IPV4_PROTOCOL_TCP:
//Process incoming TCP segment
tcpProcessSegment(interface, &pseudoHeader, buffer, offset);
//No error to report
error = NO_ERROR;
//Continue processing
break;
#endif
#if (UDP_SUPPORT == ENABLED)
//UDP protocol?
case IPV4_PROTOCOL_UDP:
//Process incoming UDP datagram
error = udpProcessDatagram(interface, &pseudoHeader, buffer, offset);
//Continue processing
break;
#endif
//Unknown protocol?
default:
#if (RAW_SOCKET_SUPPORT == ENABLED)
//Allow raw sockets to process IPv4 packets
error = rawSocketProcessIpPacket(interface, &pseudoHeader, buffer, offset);
#else
//Report an error
error = ERROR_PROTOCOL_UNREACHABLE;
#endif
//Continue processing
break;
}
//Unreachable protocol?
if(error == ERROR_PROTOCOL_UNREACHABLE)
{
//Send a Destination Unreachable message
icmpSendErrorMessage(interface, ICMP_TYPE_DEST_UNREACHABLE,
ICMP_CODE_PROTOCOL_UNREACHABLE, 0, buffer);
}
//Unreachable port?
else if(error == ERROR_PORT_UNREACHABLE)
{
//Send a Destination Unreachable message
icmpSendErrorMessage(interface, ICMP_TYPE_DEST_UNREACHABLE,
ICMP_CODE_PORT_UNREACHABLE, 0, buffer);
}
}
void dnsProcessResponse(NetInterface *interface, const IpPseudoHeader *pseudoHeader,
const UdpHeader *udpHeader, const NetBuffer *buffer, size_t offset, void *params)
{
uint_t i;
uint_t j;
size_t pos;
size_t length;
DnsHeader *message;
DnsQuestion *question;
DnsResourceRecord *resourceRecord;
DnsCacheEntry *entry;
//Retrieve the length of the DNS message
length = netBufferGetLength(buffer) - offset;
//Ensure the DNS message is valid
if(length < sizeof(DnsHeader))
return;
if(length > DNS_MESSAGE_MAX_SIZE)
return;
//Point to the DNS message header
message = netBufferAt(buffer, offset);
//Sanity check
if(!message) return;
//Debug message
TRACE_INFO("DNS message received (%" PRIuSIZE " bytes)...\r\n", length);
//Dump message
dnsDumpMessage(message, length);
//Check message type
if(!message->qr)
return;
//The DNS message shall contain one question
if(ntohs(message->qdcount) != 1)
return;
//Acquire exclusive access to the DNS cache
osAcquireMutex(&dnsCacheMutex);
//Loop through DNS cache entries
for(i = 0; i < DNS_CACHE_SIZE; i++)
{
//Point to the current entry
entry = &dnsCache[i];
//DNS name resolution in progress?
if(entry->state == DNS_STATE_IN_PROGRESS &&
entry->protocol == HOST_NAME_RESOLVER_DNS)
{
//Check destination port number
if(entry->port == ntohs(udpHeader->destPort))
{
//Compare identifier against the expected one
if(ntohs(message->id) != entry->id)
break;
//Point to the first question
pos = sizeof(DnsHeader);
//Parse domain name
pos = dnsParseName(message, length, pos, NULL, 0);
//Invalid name?
if(!pos)
break;
//Malformed mDNS message?
if((pos + sizeof(DnsQuestion)) > length)
break;
//Compare domain name
if(!dnsCompareName(message, length, sizeof(DnsHeader), entry->name, 0))
break;
//Point to the corresponding entry
question = DNS_GET_QUESTION(message, pos);
//Check the class of the query
if(ntohs(question->qclass) != DNS_RR_CLASS_IN)
break;
//Check the type of the query
if(entry->type == HOST_TYPE_IPV4 && ntohs(question->qtype) != DNS_RR_TYPE_A)
break;
if(entry->type == HOST_TYPE_IPV6 && ntohs(question->qtype) != DNS_RR_TYPE_AAAA)
break;
//Make sure recursion is available
if(!message->ra)
{
//The entry should be deleted since name resolution has failed
dnsDeleteEntry(entry);
//Exit immediately
break;
}
//Check return code
if(message->rcode != DNS_RCODE_NO_ERROR)
{
//The entry should be deleted since name resolution has failed
dnsDeleteEntry(entry);
//Exit immediately
break;
}
//Point to the first answer
pos += sizeof(DnsQuestion);
//Parse answer resource records
for(j = 0; j < ntohs(message->ancount); j++)
{
//Parse domain name
pos = dnsParseName(message, length, pos, NULL, 0);
//Invalid name?
if(!pos) break;
//Point to the associated resource record
resourceRecord = DNS_GET_RESOURCE_RECORD(message, pos);
//Point to the resource data
pos += sizeof(DnsResourceRecord);
//Make sure the resource record is valid
if(pos > length)
break;
if((pos + ntohs(resourceRecord->rdlength)) > length)
break;
#if (IPV4_SUPPORT == ENABLED)
//IPv4 address expected?
if(entry->type == HOST_TYPE_IPV4)
{
//A resource record found?
if(ntohs(resourceRecord->rtype) == DNS_RR_TYPE_A &&
ntohs(resourceRecord->rdlength) == sizeof(Ipv4Addr))
{
//Copy the IPv4 address
entry->ipAddr.length = sizeof(Ipv4Addr);
ipv4CopyAddr(&entry->ipAddr.ipv4Addr, resourceRecord->rdata);
//Save current time
entry->timestamp = osGetSystemTime();
//Save TTL value
entry->timeout = ntohl(resourceRecord->ttl) * 1000;
//Limit the lifetime of the DNS cache entries
entry->timeout = MIN(entry->timeout, DNS_MAX_LIFETIME);
//Unregister UDP callback function
udpDetachRxCallback(interface, entry->port);
//Host name successfully resolved
entry->state = DNS_STATE_RESOLVED;
//Exit immediately
break;
}
}
#endif
#if (IPV6_SUPPORT == ENABLED)
//IPv6 address expected?
if(entry->type == HOST_TYPE_IPV6)
{
//AAAA resource record found?
if(ntohs(resourceRecord->rtype) == DNS_RR_TYPE_AAAA &&
ntohs(resourceRecord->rdlength) == sizeof(Ipv6Addr))
{
//Copy the IPv6 address
entry->ipAddr.length = sizeof(Ipv6Addr);
ipv6CopyAddr(&entry->ipAddr.ipv6Addr, resourceRecord->rdata);
//Save current time
entry->timestamp = osGetSystemTime();
//Save TTL value
entry->timeout = ntohl(resourceRecord->ttl) * 1000;
//Limit the lifetime of the DNS cache entries
entry->timeout = MIN(entry->timeout, DNS_MAX_LIFETIME);
//Unregister UDP callback function
udpDetachRxCallback(interface, entry->port);
//Host name successfully resolved
entry->state = DNS_STATE_RESOLVED;
//Exit immediately
break;
}
}
#endif
//Point to the next resource record
pos += ntohs(resourceRecord->rdlength);
}
//We are done
break;
}
}
}
//Release exclusive access to the DNS cache
osReleaseMutex(&dnsCacheMutex);
}
error_t ipv4SendPacket(NetInterface *interface, Ipv4PseudoHeader *pseudoHeader,
uint16_t fragId, uint16_t fragOffset, NetBuffer *buffer, size_t offset, uint8_t ttl)
{
error_t error;
size_t length;
Ipv4Header *packet;
//Is there enough space for the IPv4 header?
if(offset < sizeof(Ipv4Header))
return ERROR_INVALID_PARAMETER;
//Make room for the header
offset -= sizeof(Ipv4Header);
//Calculate the size of the entire packet, including header and data
length = netBufferGetLength(buffer) - offset;
//Point to the IPv4 header
packet = netBufferAt(buffer, offset);
//Format IPv4 header
packet->version = IPV4_VERSION;
packet->headerLength = 5;
packet->typeOfService = 0;
packet->totalLength = htons(length);
packet->identification = htons(fragId);
packet->fragmentOffset = htons(fragOffset);
packet->timeToLive = ttl;
packet->protocol = pseudoHeader->protocol;
packet->headerChecksum = 0;
packet->srcAddr = pseudoHeader->srcAddr;
packet->destAddr = pseudoHeader->destAddr;
//Calculate IP header checksum
packet->headerChecksum = ipCalcChecksumEx(buffer, offset, packet->headerLength * 4);
//Ensure the source address is valid
error = ipv4CheckSourceAddr(interface, pseudoHeader->srcAddr);
//Invalid source address?
if(error) return error;
//Destination address is the unspecified address?
if(pseudoHeader->destAddr == IPV4_UNSPECIFIED_ADDR)
{
//Destination address is not acceptable
return ERROR_INVALID_ADDRESS;
}
//Destination address is the loopback address?
else if(pseudoHeader->destAddr == IPV4_LOOPBACK_ADDR)
{
//Not yet implemented...
return ERROR_NOT_IMPLEMENTED;
}
#if (ETH_SUPPORT == ENABLED)
//Ethernet interface?
if(interface->nicDriver->type == NIC_TYPE_ETHERNET)
{
Ipv4Addr destIpAddr;
MacAddr destMacAddr;
//Destination address is a broadcast address?
if(ipv4IsBroadcastAddr(interface, pseudoHeader->destAddr))
{
//Destination IPv4 address
destIpAddr = pseudoHeader->destAddr;
//Make use of the broadcast MAC address
destMacAddr = MAC_BROADCAST_ADDR;
//No error to report
error = NO_ERROR;
}
//Destination address is a multicast address?
else if(ipv4IsMulticastAddr(pseudoHeader->destAddr))
{
//Destination IPv4 address
destIpAddr = pseudoHeader->destAddr;
//Map IPv4 multicast address to MAC-layer multicast address
error = ipv4MapMulticastAddrToMac(pseudoHeader->destAddr, &destMacAddr);
}
//Destination host is in the local subnet?
else if(ipv4IsInLocalSubnet(interface, pseudoHeader->destAddr))
{
//Destination IPv4 address
destIpAddr = pseudoHeader->destAddr;
//Resolve host address before sending the packet
error = arpResolve(interface, pseudoHeader->destAddr, &destMacAddr);
}
//Destination host is outside the local subnet?
else
{
//Make sure the default gateway is properly set
if(interface->ipv4Config.defaultGateway != IPV4_UNSPECIFIED_ADDR)
{
//Use the default gateway to forward the packet
destIpAddr = interface->ipv4Config.defaultGateway;
//Perform address resolution
error = arpResolve(interface, interface->ipv4Config.defaultGateway, &destMacAddr);
}
else
{
//There is no route to the outside world...
error = ERROR_NO_ROUTE;
}
}
//Successful address resolution?
if(!error)
{
//Debug message
TRACE_INFO("Sending IPv4 packet (%" PRIuSIZE " bytes)...\r\n", length);
//Dump IP header contents for debugging purpose
ipv4DumpHeader(packet);
//Send Ethernet frame
error = ethSendFrame(interface, &destMacAddr, buffer, offset, ETH_TYPE_IPV4);
}
//Address resolution is in progress?
else if(error == ERROR_IN_PROGRESS)
{
//Debug message
TRACE_INFO("Enqueuing IPv4 packet (%" PRIuSIZE " bytes)...\r\n", length);
//Dump IP header contents for debugging purpose
ipv4DumpHeader(packet);
//Enqueue packets waiting for address resolution
error = arpEnqueuePacket(interface, destIpAddr, buffer, offset);
}
//Address resolution failed?
else
{
//Debug message
TRACE_WARNING("Cannot map IPv4 address to Ethernet address!\r\n");
}
}
else
#endif
#if (PPP_SUPPORT == ENABLED)
//PPP interface?
if(interface->nicDriver->type == NIC_TYPE_PPP)
{
//Debug message
TRACE_INFO("Sending IPv4 packet (%" PRIuSIZE " bytes)...\r\n", length);
//Dump IP header contents for debugging purpose
ipv4DumpHeader(packet);
//Send PPP frame
error = pppSendFrame(interface, buffer, offset, PPP_PROTOCOL_IP);
}
else
#endif
//Unknown interface type?
{
//Report an error
error = ERROR_INVALID_INTERFACE;
}
//Return status code
return error;
}