VOID ICMPTransmit(
PIP_PACKET IPPacket,
PIP_TRANSMIT_COMPLETE Complete,
PVOID Context)
/*
* FUNCTION: Transmits an ICMP packet
* ARGUMENTS:
* NTE = Pointer to net table entry to use (NULL if don't care)
* IPPacket = Pointer to IP packet to transmit
*/
{
PNEIGHBOR_CACHE_ENTRY NCE;
TI_DbgPrint(DEBUG_ICMP, ("Called.\n"));
/* Calculate checksum of ICMP header and data */
((PICMP_HEADER)IPPacket->Data)->Checksum = (USHORT)
IPv4Checksum(IPPacket->Data, IPPacket->TotalSize - IPPacket->HeaderSize, 0);
/* Get a route to the destination address */
if ((NCE = RouteGetRouteToDestination(&IPPacket->DstAddr))) {
/* Send the packet */
IPSendDatagram(IPPacket, NCE);
} else {
/* No route to destination (or no free resources) */
TI_DbgPrint(DEBUG_ICMP, ("No route to destination address 0x%X.\n",
IPPacket->DstAddr.Address.IPv4Address));
IPPacket->Free(IPPacket);
}
}
VOID ARPReceive(
PVOID Context,
PIP_PACKET Packet)
/*
* FUNCTION: Receives an ARP packet
* ARGUMENTS:
* Context = Pointer to context information (IP_INTERFACE)
* Packet = Pointer to packet
*/
{
PARP_HEADER Header;
IP_ADDRESS SrcAddress;
IP_ADDRESS DstAddress;
PCHAR SenderHWAddress, SenderProtoAddress, TargetProtoAddress;
PNEIGHBOR_CACHE_ENTRY NCE;
PNDIS_PACKET NdisPacket;
PIP_INTERFACE Interface = (PIP_INTERFACE)Context;
ULONG BytesCopied, DataSize;
PCHAR DataBuffer;
PAGED_CODE();
TI_DbgPrint(DEBUG_ARP, ("Called.\n"));
Packet->Header = ExAllocatePoolWithTag(PagedPool,
sizeof(ARP_HEADER),
PACKET_BUFFER_TAG);
if (!Packet->Header)
{
TI_DbgPrint(DEBUG_ARP, ("Unable to allocate header buffer\n"));
Packet->Free(Packet);
return;
}
Packet->MappedHeader = FALSE;
BytesCopied = CopyPacketToBuffer((PCHAR)Packet->Header,
Packet->NdisPacket,
Packet->Position,
sizeof(ARP_HEADER));
if (BytesCopied != sizeof(ARP_HEADER))
{
TI_DbgPrint(DEBUG_ARP, ("Unable to copy in header buffer\n"));
Packet->Free(Packet);
return;
}
Header = (PARP_HEADER)Packet->Header;
/* FIXME: Ethernet only */
if (WN2H(Header->HWType) != 1) {
TI_DbgPrint(DEBUG_ARP, ("Unknown ARP hardware type (0x%X).\n", WN2H(Header->HWType)));
Packet->Free(Packet);
return;
}
/* Check protocol type */
if (Header->ProtoType != ETYPE_IPv4) {
TI_DbgPrint(DEBUG_ARP, ("Unknown ARP protocol type (0x%X).\n", WN2H(Header->ProtoType)));
Packet->Free(Packet);
return;
}
DataSize = (2 * Header->HWAddrLen) + (2 * Header->ProtoAddrLen);
DataBuffer = ExAllocatePool(PagedPool,
DataSize);
if (!DataBuffer)
{
TI_DbgPrint(DEBUG_ARP, ("Unable to allocate data buffer\n"));
Packet->Free(Packet);
return;
}
BytesCopied = CopyPacketToBuffer(DataBuffer,
Packet->NdisPacket,
Packet->Position + sizeof(ARP_HEADER),
DataSize);
if (BytesCopied != DataSize)
{
TI_DbgPrint(DEBUG_ARP, ("Unable to copy in data buffer\n"));
ExFreePool(DataBuffer);
Packet->Free(Packet);
return;
}
SenderHWAddress = (PVOID)(DataBuffer);
SenderProtoAddress = (PVOID)(SenderHWAddress + Header->HWAddrLen);
TargetProtoAddress = (PVOID)(SenderProtoAddress + Header->ProtoAddrLen + Header->HWAddrLen);
AddrInitIPv4(&DstAddress, *((PULONG)TargetProtoAddress));
if (!AddrIsEqual(&DstAddress, &Interface->Unicast))
{
ExFreePool(DataBuffer);
Packet->Free(Packet);
return;
}
AddrInitIPv4(&SrcAddress, *((PULONG)SenderProtoAddress));
/* Check if we know the sender */
NCE = NBLocateNeighbor(&SrcAddress, Interface);
if (NCE) {
/* We know the sender. Update the hardware address
and state in our neighbor address cache */
NBUpdateNeighbor(NCE, SenderHWAddress, 0);
} else {
/* The packet had our protocol address as target. The sender
may want to communicate with us soon, so add his address
to our address cache */
NBAddNeighbor(Interface, &SrcAddress, SenderHWAddress,
Header->HWAddrLen, 0, ARP_COMPLETE_TIMEOUT);
}
if (Header->Opcode != ARP_OPCODE_REQUEST)
{
ExFreePool(DataBuffer);
Packet->Free(Packet);
return;
}
/* This is a request for our address. Swap the addresses and
send an ARP reply back to the sender */
NdisPacket = PrepareARPPacket(
Interface,
Header->HWType, /* Hardware type */
Header->ProtoType, /* Protocol type */
(UCHAR)Interface->AddressLength, /* Hardware address length */
(UCHAR)Header->ProtoAddrLen, /* Protocol address length */
Interface->Address, /* Sender's (local) hardware address */
&Interface->Unicast.Address.IPv4Address,/* Sender's (local) protocol address */
SenderHWAddress, /* Target's (remote) hardware address */
SenderProtoAddress, /* Target's (remote) protocol address */
ARP_OPCODE_REPLY); /* ARP reply */
if (NdisPacket) {
PC(NdisPacket)->DLComplete = ARPTransmitComplete;
(*Interface->Transmit)(Interface->Context,
NdisPacket,
0,
SenderHWAddress,
LAN_PROTO_ARP);
}
ExFreePool(DataBuffer);
Packet->Free(Packet);
}