/***************************************************************************** Function: static bool ARP_SendIfPkt(NET_CONFIG* pIf, uint16_t oper, uint32_t srcIP, uint32_t dstIP, MAC_ADDR* dstMAC) Description: Writes an ARP packet to the MAC using the interface pointer for src IP and MAC address. Precondition: None Parameters: Return Values: true - The ARP packet was generated properly false - otherwise ***************************************************************************/ static bool ARP_SendIfPkt(NET_CONFIG* pIf, uint16_t oper, uint32_t srcIP, uint32_t dstIP, MAC_ADDR* dstMAC) { ARP_PACKET packet; TCPIP_MAC_HANDLE hMac; packet.HardwareType = HW_ETHERNET; packet.Protocol = ARP_IP; packet.MACAddrLen = sizeof(MAC_ADDR); packet.ProtocolLen = sizeof(IP_ADDR); packet.Operation = oper; packet.SenderMACAddr = pIf->MyMACAddr; packet.SenderIPAddr.Val = srcIP; packet.TargetMACAddr = *dstMAC; packet.TargetIPAddr.Val = dstIP; SwapARPPacket(&packet); hMac = _TCPIPStackNetToMac(pIf); if(!MACIsTxReady(hMac)) { return false; } MACSetWritePtr(hMac, MACGetTxBaseAddr(hMac)); MACPutHeader(hMac, &packet.TargetMACAddr, ETHERTYPE_ARP, sizeof(packet)); MACPutArray(hMac, (uint8_t*)&packet, sizeof(packet)); MACFlush(hMac); return true; }
void AutoIPTasks(NET_CONFIG* pConfig) { // uint8_t i; TCPIP_MAC_HANDLE hMac; // for (i = 0; i < NETWORK_INTERFACES; i++) { LoadState(_TCPIPStackNetIx(pConfig)); hMac = _TCPIPStackNetToMac(pConfig); AutoIPClient.flags.bits.bCurrentLinkState = MACIsLinked(hMac); if(AutoIPClient.flags.bits.bCurrentLinkState != AutoIPClient.flags.bits.bLastLinkState) { AutoIPClient.flags.bits.bLastLinkState = AutoIPClient.flags.bits.bCurrentLinkState; if(!AutoIPClient.flags.bits.bCurrentLinkState) { AutoIPClient.flags.bits.bConfigureAutoIP = false; AutoIPClient.smAUTOIPState = SM_AUTOIP_DISABLED; pConfig->MyIPAddr.Val = pConfig->DefaultIPAddr.Val; pConfig->MyMask.Val = pConfig->DefaultMask.Val; } else { AutoIPClient.smAUTOIPState = SM_AUTOIP_INIT_RNG; } } #if defined (TCPIP_STACK_USE_DHCP_CLIENT) if (DHCPIsBound(pConfig)) { AutoIPClient.flags.bits.bConfigureAutoIP = false; AutoIPClient.smAUTOIPState = SM_AUTOIP_DISABLED; AutoIPClient.flags.bits.bLastDHCPState = true; } else { if (AutoIPClient.flags.bits.bLastDHCPState == true) { if (AutoIPClient.flags.bits.bCurrentLinkState) AutoIPClient.smAUTOIPState = SM_AUTOIP_INIT_RNG; } AutoIPClient.flags.bits.bLastDHCPState = false; } #endif if (AutoIPClient.flags.bits.gDisableAutoIP == true) { AutoIPClient.flags.bits.bConfigureAutoIP = false; AutoIPClient.smAUTOIPState = SM_AUTOIP_DISABLED; } switch (AutoIPClient.smAUTOIPState) { // Default no-AutoIP case case SM_AUTOIP_DISABLED: break; // Initializes the random number generator with a seed based on the MAC address case SM_AUTOIP_INIT_RNG: AutoIPRandSeed (((uint32_t)pConfig->MyMACAddr.v[0] + ((uint32_t)pConfig->MyMACAddr.v[1] << 8) + \ ((uint32_t)pConfig->MyMACAddr.v[2] << 16) + ((uint32_t)pConfig->MyMACAddr.v[3] << 24) + \ ((uint32_t)pConfig->MyMACAddr.v[4]) + ((uint32_t)pConfig->MyMACAddr.v[5] << 8)), pConfig); AutoIPClient.smAUTOIPState = SM_AUTOIP_CHECK_ADDRESS; // Check the address to see if it's in use before we write it into NetConfig case SM_AUTOIP_CHECK_ADDRESS: if (AutoIPClient.flags.bits.checkAddress == false) { AutoIPClient.flags.bits.checkAddress = true; pConfig->MyMask.Val = 0x00000000; // Generate a random IP address (based on the MAC address) to try and claim. // Dynamic link-local addresses can fall within the range: // 169.254.1.0 - 169.254.254.255 AutoIPClient.packet.TargetIPAddr.byte.MB = AutoIPRand(pConfig) % 256; AutoIPClient.packet.TargetIPAddr.byte.UB = (AutoIPRand(pConfig) % 254) + 1; AutoIPClient.packet.TargetIPAddr.word.LW = 0xFEA9; ARPResolve (pConfig, &AutoIPClient.packet.TargetIPAddr); AutoIPClient.eventTime = SYS_TICK_Get(); } if (!ARPIsResolved (pConfig, &AutoIPClient.packet.TargetIPAddr, &AutoIPClient.packet.TargetMACAddr)) { if (SYS_TICK_Get() - AutoIPClient.eventTime > SYS_TICK_TicksPerSecondGet()) { AutoIPClient.smAUTOIPState = SM_AUTOIP_SETUP_MESSAGE; } } else { AutoIPClient.flags.bits.checkAddress = false; } break; // Set up an ARP packet case SM_AUTOIP_SETUP_MESSAGE: AutoIPClient.flags.bits.checkAddress = false; // Set the bConfigureAutoIP flag- This flag will cause an AutoIP conflict // if a response packet is received from the address we're trying to claim. AutoIPClient.flags.bits.bConfigureAutoIP = true; // Configure the fields for a gratuitous ARP packet AutoIPClient.packet.Operation = ARP_OPERATION_REQ; AutoIPClient.packet.TargetMACAddr.v[0] = 0xff; AutoIPClient.packet.TargetMACAddr.v[1] = 0xff; AutoIPClient.packet.TargetMACAddr.v[2] = 0xff; AutoIPClient.packet.TargetMACAddr.v[3] = 0xff; AutoIPClient.packet.TargetMACAddr.v[4] = 0xff; AutoIPClient.packet.TargetMACAddr.v[5] = 0xff; pConfig->MyIPAddr = AutoIPClient.packet.TargetIPAddr; pConfig->MyMask.Val = 0x0000FFFF; memcpy(&AutoIPClient.packet.SenderMACAddr, (void*)&pConfig->MyMACAddr, sizeof(AutoIPClient.packet.SenderMACAddr)); AutoIPClient.packet.HardwareType = HW_ETHERNET; AutoIPClient.packet.Protocol = ARP_IP; AutoIPClient.packet.MACAddrLen = sizeof(MAC_ADDR); AutoIPClient.packet.ProtocolLen = sizeof(IP_ADDR); AutoIPClient.packet.SenderIPAddr.Val = AutoIPClient.packet.TargetIPAddr.Val; SwapARPPacket(&AutoIPClient.packet); // Generate a random delay between 0 and 1 second AutoIPClient.randomDelay = ((LFSRRand() % 20) * SYS_TICK_TicksPerSecondGet()) / 20; // Store the current time AutoIPClient.eventTime = SYS_TICK_Get(); // Set the state to send the ARP packet AutoIPClient.smAUTOIPState = SM_AUTOIP_GRATUITOUS_ARP1; break; // Send a gratuitous ARP packet to try and claim our address case SM_AUTOIP_GRATUITOUS_ARP1: case SM_AUTOIP_GRATUITOUS_ARP2: case SM_AUTOIP_GRATUITOUS_ARP3: // Check to ensure we've passed the delay time if (SYS_TICK_Get() - AutoIPClient.eventTime > AutoIPClient.randomDelay) { if(!MACIsTxReady(hMac)) { break; } // Store the new event time AutoIPClient.eventTime = SYS_TICK_Get(); // Generate a new random delay between 1 and 2 seconds AutoIPClient.randomDelay = SYS_TICK_TicksPerSecondGet() + (((LFSRRand() % 20) * SYS_TICK_TicksPerSecondGet()) / 20); // Transmit the packet MACSetWritePtr(hMac, MACGetTxBaseAddr(hMac)); MACPutHeader(hMac, &AutoIPClient.packet.TargetMACAddr, ETHERTYPE_ARP, sizeof(AutoIPClient.packet)); MACPutArray(hMac, (uint8_t*)&AutoIPClient.packet, sizeof(AutoIPClient.packet)); MACFlush(hMac); // Increment the probe iteration or increment to the delay state AutoIPClient.smAUTOIPState++; } break; // Delay for 1-2 seconds after sending the third ARP request before // entering the configured state case SM_AUTOIP_DELAY: if (SYS_TICK_Get() - AutoIPClient.eventTime > AutoIPClient.randomDelay) AutoIPClient.smAUTOIPState = SM_AUTOIP_CONFIGURED; break; // Configure the module to limit the rate at which packets are sent case SM_AUTOIP_RATE_LIMIT_SET: AutoIPClient.eventTime = SYS_TICK_Get(); pConfig->MyIPAddr.Val = pConfig->DefaultIPAddr.Val; AutoIPClient.smAUTOIPState = SM_AUTOIP_RATE_LIMIT_WAIT; break; // Ensure that we don't try more than one address every 60 seconds case SM_AUTOIP_RATE_LIMIT_WAIT: if (SYS_TICK_Get() - AutoIPClient.eventTime > SYS_TICK_TicksPerSecondGet() * 60) AutoIPClient.smAUTOIPState = SM_AUTOIP_CHECK_ADDRESS; break; // Configured state case SM_AUTOIP_CONFIGURED: AutoIPClient.flags.bits.bConfigureAutoIP = false; break; // Address defense state case SM_AUTOIP_DEFEND: // Prepare and send an ARP response if(!MACIsTxReady(hMac)) { break; } AutoIPClient.packet.Operation = ARP_OPERATION_RESP; AutoIPClient.packet.HardwareType = HW_ETHERNET; AutoIPClient.packet.Protocol = ARP_IP; SwapARPPacket(&AutoIPClient.packet); MACSetWritePtr(hMac, MACGetTxBaseAddr(hMac)); MACPutHeader(hMac, &AutoIPClient.packet.TargetMACAddr, ETHERTYPE_ARP, sizeof(AutoIPClient.packet)); MACPutArray(hMac, (uint8_t*)&AutoIPClient.packet, sizeof(AutoIPClient.packet)); MACFlush(hMac); AutoIPClient.smAUTOIPState = SM_AUTOIP_CONFIGURED; break; } } }