IDS.zip_ns2 code_ns2 ids_project

/************************************************************************************ * Copyright (C) 2013 * * TETCOS, Bangalore. India * * Tetcos owns the intellectual property rights in the Product and its content. * * The copying, redistribution, reselling or publication of any or all of the * * Product or its content without express prior written consent of Tetcos is * * prohibited. Ownership and / or any other right relating to the software and all * * intellectual property rights therein shall remain at all times with Tetcos. * * Author: Basamma YB * ************************************************************************************/ #include "main.h" #include "WLAN.h" #include "802_11n_ac.h" #include "watchdog.h" /** ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ This function is called when MAC_OUT_EVENT trigged when a packet buffer to process in the MAC layer carrier sense. It check the Medium, if Medium is BUSY, CS failed return 0. If Medium is IDLE, packets in the buffer, update arrival time, add CHECK NAV sub event, return 1 to indicate CS success. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ */ int fn_NetSim_WLAN_CarrierSense() { int nDestPresentFlag; NETSIM_ID nDeviceId = pstruEventDetails->nDeviceId; NETSIM_ID nInterfaceId = pstruEventDetails->nInterfaceId; MAC_VAR *pstruMac = DEVICE_MACVAR(nDeviceId,nInterfaceId); PHY_VAR *pstruPhy = DEVICE_PHYVAR(nDeviceId,nInterfaceId); NetSim_PACKET* pstruPacket; if(pstruMac->Medium != IDLE && pstruMac->CurrentState != MAC_IDLE)// && pstruPhy->RadioState == CHANNEL_IDLE) return 0; //CS failed if(pstruMac->pstruTempData) pstruPacket = pstruMac->pstruTempData; else { pstruPacket = fn_NetSim_WLAN_Packet_GetPacketFromBuffer(pstruMac->pstruQosList,0); if(!pstruPacket) return 0; //CS failed } //Check the destination is with in the BSS if device is an AP for unicast frames if(nDeviceId == pstruPhy->nBSSID && pstruPhy->BssType == INFRASTRUCTURE) { if(pstruPacket->nDestinationId) { nDestPresentFlag = fn_NetSim_WLAN_CheckDestDevicePresentWithinAP(nDeviceId,nInterfaceId,pstruPacket->nDestinationId); if(!nDestPresentFlag) { // Get packet from buffer and move to next packet pstruPacket = fn_NetSim_WLAN_Packet_GetPacketFromBuffer(pstruMac->pstruQosList,1); // Drop the packet fn_NetSim_Packet_FreePacket(pstruPacket); pstruPacket = NULL; // If buffer is not NULL add MAC OUT event to process the next packet pstruPacket = fn_NetSim_WLAN_Packet_GetPacketFromBuffer(pstruMac->pstruQosList,0); if(!pstruPacket) return 0; //CS failed pstruEventDetails->nPacketId = pstruPacket->nPacketId; if(pstruPacket->pstruAppData) pstruEventDetails->nSegmentId = pstruPacket->pstruAppData->nSegmentId; else pstruEventDetails->nSegmentId = 0; } } } // Set the Start and Arrival time if(pstruMac->nRetryCount == 0) { if(nDeviceId == pstruPhy->nBSSID && pstruPhy->BssType == INFRASTRUCTURE) // AP { pstruPacket->pstruMacData->dArrivalTime = pstruPacket->pstruMacData->dArrivalTime; } else // Wireless Nodes { pstruPacket->pstruMacData->dArrivalTime = pstruPacket->pstruNetworkData->dEndTime; } pstruPacket->pstruMacData->dStartTime = pstruEventDetails->dEventTime; } if(pstruMac->nCSFlag == 0) { // Add CHECK NAV sub event //pstruEventDetails->pPacket = pstruPacket; pstruEventDetails->nPacketId = pstruPacket->nPacketId; pstruEventDetails->nSubEventType = WLAN_SUBEVENT(CHECK_NAV,pstruEventDetails->nProtocolId); pstruMac->nCSFlag = 1; return 1; // CS successfull } return 0; } /** ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ This function called when CHECK_NAV subevent triggered. It is called if the Medium is IDLE and a packet in the Accessbuffer to transmit. If NAV <=0 then change the state to Wait_DIFS and add DIFS_END subevent. If NAV > 0 then change the state to WF_NAV and add NAV_END subevent. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ */ _declspec(dllexport) int fn_NetSim_WLAN_CheckNAV() { NETSIM_ID nDeviceId = pstruEventDetails->nDeviceId; NETSIM_ID nInterfaceId = pstruEventDetails->nInterfaceId; NETSIM_ID nProtocolId = pstruEventDetails->nProtocolId; MAC_VAR *pstruMacVar = DEVICE_MACVAR(nDeviceId,nInterfaceId); PHY_VAR *pstruPhyVar = DEVICE_PHYVAR(nDeviceId,nInterfaceId); if(pstruEventDetails->dEventTime >= pstruMacVar->dNAV) { // Change the State fn_NetSim_WLAN_ChangeMacState(pstruMacVar,Wait_DIFS); // Add DIFS_END subevent pstruEventDetails->dEventTime = pstruEventDetails->dEventTime + pstruPhyVar->nDIFS; pstruEventDetails->nSubEventType = WLAN_SUBEVENT(DIFS_END,nProtocolId); pstruEventDetails->pPacket = NULL; fnpAddEvent(pstruEventDetails); } else { // Change the State fn_NetSim_WLAN_ChangeMacState(pstruMacVar,MAC_IDLE); pstruMacVar->nCSFlag = 0; // Reset the CS flag } return 0; } /** ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ When the buffer has packet to transmit, the MAC LAYER sense the Medium. If it is IDLE, then it will wait for DCF Inter Frame Space (DIFS) time before start transmission. At the end of DIFS time check the Medium. If Medium is IDLE, then change the State to BACKING_OFF, call the function to start backoff. If Medium is BUSY, then change the state to IDLE. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ */ _declspec(dllexport) int fn_NetSim_WLAN_DIFS(fnIncreaseCW fnpIncreaseCW,fnRandomBackOffTimeCalculation fnpRandomBackOffTimeCalculation) { NETSIM_ID nDeviceId = pstruEventDetails->nDeviceId; NETSIM_ID nInterfaceId = pstruEventDetails->nInterfaceId; MAC_VAR *pstruMac = DEVICE_MACVAR(nDeviceId, nInterfaceId); // check the medium if(pstruMac->Medium == IDLE) { // Change the state fn_NetSim_WLAN_ChangeMacState(pstruMac,BACKING_OFF); // Start Backoff //pstruMac->BackOffFreezeFlag = 0; fn_NetSim_WLAN_StartBackOff(fnpIncreaseCW,fnpRandomBackOffTimeCalculation); } else { fn_NetSim_WLAN_ChangeMacState(pstruMac,MAC_IDLE); } pstruMac->nCSFlag = 0; // Reset cs flag return 0; } /** This function start the Backoff process. If backoff counter != 0,it adds the backoff event at (event time + backoff time) else it generate the random backoff time and add the backoff event. */ int fn_NetSim_WLAN_StartBackOff(fnIncreaseCW fnpIncreaseCW,fnRandomBackOffTimeCalculation fnpRandomBackOffTimeCalculation) { NETSIM_ID nDeviceId = pstruEventDetails->nDeviceId; NETSIM_ID nInterfaceId = pstruEventDetails->nInterfaceId; NETSIM_ID nProtocolId = pstruEventDetails->nProtocolId; MAC_VAR *pstruMac = DEVICE_MACVAR(nDeviceId, nInterfaceId); pstruMac->dBackOffStartTime = pstruEventDetails->dEventTime; if(pstruMac->dBackOffCounter == 0) { if(pstruMac->nRetryCount == 0) fnpIncreaseCW();// Expand the Contention Window fnpRandomBackOffTimeCalculation(); } pstruMac->dBackOffCounter = pstruMac->dBackOffTime; pstruMac->BackOffFreezeFlag = 0; //Set BackOffFreezFlag as Zero pstruEventDetails->dEventTime = pstruEventDetails->dEventTime + pstruMac->dBackOffTime; pstruEventDetails->nEventType = MAC_OUT_EVENT; pstruEventDetails->nSubEventType = WLAN_SUBEVENT(BACKOFF,nProtocolId); pstruEventDetails->pPacket = NULL; fnpAddEvent(pstruEventDetails); return 0; } /** ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ This function is used to expand the CW. If the RetryCount = 0, then CWcurrent is set to CWmin th