A stack which works with or without an Mbed os library. Provides IPv4 or IPv6 with a full 1500 byte buffer.
Dependents: oldheating gps motorhome heating
eth/arp.cpp
- Committer:
- andrewboyson
- Date:
- 2017-09-22
- Revision:
- 35:93c39d260a83
- Parent:
- 30:e34173b7585c
- Child:
- 36:900e24b27bfb
File content as of revision 35:93c39d260a83:
#include "mbed.h" #include "log.h" #include "net.h" #include "eth.h" #include "mac.h" #include "dhcp.h" #include "ar.h" #include "nr.h" #include "io.h" #define REQUEST 1 #define REPLY 2 #define DEBUG false uint32_t ArpAddressToResolve; bool ArpResolveRequestFlag = false; __packed struct header { int16_t hardwareType; //16.bit: (ar$hrd) Hardware address space (e.g., Ethernet, Packet Radio Net). Always 1. int16_t protocolType; //16.bit: (ar$pro) Protocol address space. For Ethernet hardware, this is from the set of type fields ether_typ$<protocol>. As held in eth.h, eg IPv4 = 0x8000. int8_t hardwareLength; // 8.bit: (ar$hln) byte length of each hardware address. Always 6 bytes. int8_t protocolLength; // 8.bit: (ar$pln) byte length of each protocol address. Always 4 bytes. int16_t opCode; //16.bit: (ar$op) opcode (ares_op$REQUEST = 1 | ares_op$REPLY = 2), high byte transmitted first. char senderHardwareAddress[6]; //nbytes: (ar$sha) Hardware address of sender of this packet, n from the ar$hln field. uint32_t senderProtocolAddress; //mbytes: (ar$spa) Protocol address of sender of this packet, m from the ar$pln field. char targetHardwareAddress[6]; //nbytes: (ar$tha) Hardware address of target of this packet (if known). uint32_t targetProtocolAddress; //mbytes: (ar$tpa) Protocol address of target. }; int ArpHandleReceivedPacket(char* pSrcMac, void * pPacket, int* pSize, char* pDstMac) { struct header* pHeader = (header*)pPacket; int16_t hardwareType = NetToHost16(pHeader->hardwareType); int16_t protocolType = NetToHost16(pHeader->protocolType); int8_t hardwareLength = pHeader->hardwareLength; int8_t protocolLength = pHeader->protocolLength; int16_t opCode = NetToHost16(pHeader->opCode); uint32_t targetProtocolAddress = pHeader->targetProtocolAddress; if (hardwareType != ETHERNET ) return DO_NOTHING; //This is not ethernet if (protocolType != IPV4 ) return DO_NOTHING; //This is not IPv4 if (hardwareLength != 6 ) return DO_NOTHING; //This is not a MAC hardware address if (protocolLength != 4 ) return DO_NOTHING; //This is not an IPv4 IP address if (targetProtocolAddress != DhcpLocalIp ) return DO_NOTHING; //This packet was not addressed to us switch (opCode) { case REQUEST: memcpy(pHeader->targetHardwareAddress, pHeader->senderHardwareAddress, 6); pHeader->targetProtocolAddress = pHeader->senderProtocolAddress; memcpy(pHeader->senderHardwareAddress, MacLocal,6); pHeader->senderProtocolAddress = DhcpLocalIp; pHeader->opCode = NetToHost16(REPLY); memcpy(pDstMac, pSrcMac, 6); return UNICAST; case REPLY: ArAddIp4Record(pHeader->senderHardwareAddress, pHeader->senderProtocolAddress); NrMakeRequestForNameFromIp4(pHeader->senderProtocolAddress); return DO_NOTHING; default: return DO_NOTHING; } } int ArpPollForPacketToSend(void* pPacket, int* pSize) { if (!ArpResolveRequestFlag) return DO_NOTHING; ArpResolveRequestFlag = false; struct header* pHeader = (header*)pPacket; pHeader->hardwareType = NetToHost16(ETHERNET); pHeader->protocolType = NetToHost16(IPV4); pHeader->hardwareLength = 6; pHeader->protocolLength = 4; pHeader->opCode = NetToHost16(REQUEST); memset(pHeader->targetHardwareAddress, 0, 6); pHeader->targetProtocolAddress = ArpAddressToResolve; memcpy(pHeader->senderHardwareAddress, MacLocal,6); pHeader->senderProtocolAddress = DhcpLocalIp; *pSize = sizeof(header); return BROADCAST; }