examples/platforms/posix/radio.c - nest-detect/1.0/openthread - Git at Google

 /*
  *  Copyright (c) 2016, The OpenThread Authors.
  *  All rights reserved.
  *
  *  Redistribution and use in source and binary forms, with or without
  *  modification, are permitted provided that the following conditions are met:
  *  1. Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  *  2. Redistributions in binary form must reproduce the above copyright
  *     notice, this list of conditions and the following disclaimer in the
  *     documentation and/or other materials provided with the distribution.
  *  3. Neither the name of the copyright holder nor the
  *     names of its contributors may be used to endorse or promote products
  *     derived from this software without specific prior written permission.
  *
  *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  *  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  *  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  *  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
  *  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  *  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  *  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  *  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  *  POSSIBILITY OF SUCH DAMAGE.
  */

 #include "platform-posix.h"

 #include <openthread/platform/diag.h>
 #include <openthread/platform/radio.h>

 #include "utils/code_utils.h"

 enum
 {
     IEEE802154_MIN_LENGTH         = 5,
     IEEE802154_MAX_LENGTH         = 127,
     IEEE802154_ACK_LENGTH         = 5,

     IEEE802154_BROADCAST          = 0xffff,

     IEEE802154_FRAME_TYPE_ACK     = 2 << 0,
     IEEE802154_FRAME_TYPE_MACCMD  = 3 << 0,
     IEEE802154_FRAME_TYPE_MASK    = 7 << 0,

     IEEE802154_SECURITY_ENABLED   = 1 << 3,
     IEEE802154_FRAME_PENDING      = 1 << 4,
     IEEE802154_ACK_REQUEST        = 1 << 5,
     IEEE802154_PANID_COMPRESSION  = 1 << 6,

     IEEE802154_DST_ADDR_NONE      = 0 << 2,
     IEEE802154_DST_ADDR_SHORT     = 2 << 2,
     IEEE802154_DST_ADDR_EXT       = 3 << 2,
     IEEE802154_DST_ADDR_MASK      = 3 << 2,

     IEEE802154_SRC_ADDR_NONE      = 0 << 6,
     IEEE802154_SRC_ADDR_SHORT     = 2 << 6,
     IEEE802154_SRC_ADDR_EXT       = 3 << 6,
     IEEE802154_SRC_ADDR_MASK      = 3 << 6,

     IEEE802154_DSN_OFFSET         = 2,
     IEEE802154_DSTPAN_OFFSET      = 3,
     IEEE802154_DSTADDR_OFFSET     = 5,

     IEEE802154_SEC_LEVEL_MASK     = 7 << 0,

     IEEE802154_KEY_ID_MODE_0      = 0 << 3,
     IEEE802154_KEY_ID_MODE_1      = 1 << 3,
     IEEE802154_KEY_ID_MODE_2      = 2 << 3,
     IEEE802154_KEY_ID_MODE_3      = 3 << 3,
     IEEE802154_KEY_ID_MODE_MASK   = 3 << 3,

     IEEE802154_MACCMD_DATA_REQ    = 4,
 };

 enum
 {
     POSIX_RECEIVE_SENSITIVITY = -100,  // dBm
 };

 OT_TOOL_PACKED_BEGIN
 struct RadioMessage
 {
     uint8_t mChannel;
     uint8_t mPsdu[OT_RADIO_FRAME_MAX_SIZE];
 } OT_TOOL_PACKED_END;

 static void radioTransmit(struct RadioMessage *msg, const struct otRadioFrame *pkt);
 static void radioSendMessage(otInstance *aInstance);
 static void radioSendAck(void);
 static void radioProcessFrame(otInstance *aInstance);

 static otRadioState sState = OT_RADIO_STATE_DISABLED;
 static struct RadioMessage sReceiveMessage;
 static struct RadioMessage sTransmitMessage;
 static struct RadioMessage sAckMessage;
 static otRadioFrame sReceiveFrame;
 static otRadioFrame sTransmitFrame;
 static otRadioFrame sAckFrame;

 static uint8_t sExtendedAddress[OT_EXT_ADDRESS_SIZE];
 static uint16_t sShortAddress;
 static uint16_t sPanid;
 static int sSockFd;
 static bool sPromiscuous = false;
 static bool sAckWait = false;
 static uint16_t sPortOffset = 0;

 static inline bool isFrameTypeAck(const uint8_t *frame)
 {
     return (frame[0] & IEEE802154_FRAME_TYPE_MASK) == IEEE802154_FRAME_TYPE_ACK;
 }

 static inline bool isFrameTypeMacCmd(const uint8_t *frame)
 {
     return (frame[0] & IEEE802154_FRAME_TYPE_MASK) == IEEE802154_FRAME_TYPE_MACCMD;
 }

 static inline bool isSecurityEnabled(const uint8_t *frame)
 {
     return (frame[0] & IEEE802154_SECURITY_ENABLED) != 0;
 }

 static inline bool isAckRequested(const uint8_t *frame)
 {
     return (frame[0] & IEEE802154_ACK_REQUEST) != 0;
 }

 static inline bool isPanIdCompressed(const uint8_t *frame)
 {
     return (frame[0] & IEEE802154_PANID_COMPRESSION) != 0;
 }

 static inline bool isDataRequest(const uint8_t *frame)
 {
     const uint8_t *cur = frame;
     uint8_t securityControl;
     bool rval;

     // FCF + DSN
     cur += 2 + 1;

     otEXPECT_ACTION(isFrameTypeMacCmd(frame), rval = false);

     // Destination PAN + Address
     switch (frame[1] & IEEE802154_DST_ADDR_MASK)
     {
     case IEEE802154_DST_ADDR_SHORT:
         cur += sizeof(otPanId) + sizeof(otShortAddress);
         break;

     case IEEE802154_DST_ADDR_EXT:
         cur += sizeof(otPanId) + sizeof(otExtAddress);
         break;

     default:
         rval = false;
         goto exit;
     }

     // Source PAN + Address
     switch (frame[1] & IEEE802154_SRC_ADDR_MASK)
     {
     case IEEE802154_SRC_ADDR_SHORT:
         if (!isPanIdCompressed(frame))
         {
             cur += sizeof(otPanId);
         }

         cur += sizeof(otShortAddress);
         break;

     case IEEE802154_SRC_ADDR_EXT:
         if (!isPanIdCompressed(frame))
         {
             cur += sizeof(otPanId);
         }

         cur += sizeof(otExtAddress);
         break;

     default:
         rval = false;
         goto exit;
     }

     // Security Control + Frame Counter + Key Identifier
     if (isSecurityEnabled(frame))
     {
         securityControl = *cur;

         if (securityControl & IEEE802154_SEC_LEVEL_MASK)
         {
             cur += 1 + 4;
         }

         switch (securityControl & IEEE802154_KEY_ID_MODE_MASK)
         {
         case IEEE802154_KEY_ID_MODE_0:
             cur += 0;
             break;

         case IEEE802154_KEY_ID_MODE_1:
             cur += 1;
             break;

         case IEEE802154_KEY_ID_MODE_2:
             cur += 5;
             break;

         case IEEE802154_KEY_ID_MODE_3:
             cur += 9;
             break;
         }
     }

     // Command ID
     rval = cur[0] == IEEE802154_MACCMD_DATA_REQ;

 exit:
     return rval;
 }

 static inline uint8_t getDsn(const uint8_t *frame)
 {
     return frame[IEEE802154_DSN_OFFSET];
 }

 static inline otPanId getDstPan(const uint8_t *frame)
 {
     return (otPanId)((frame[IEEE802154_DSTPAN_OFFSET + 1] << 8) | frame[IEEE802154_DSTPAN_OFFSET]);
 }

 static inline otShortAddress getShortAddress(const uint8_t *frame)
 {
     return (otShortAddress)((frame[IEEE802154_DSTADDR_OFFSET + 1] << 8) | frame[IEEE802154_DSTADDR_OFFSET]);
 }

 static inline void getExtAddress(const uint8_t *frame, otExtAddress *address)
 {
     size_t i;

     for (i = 0; i < sizeof(otExtAddress); i++)
     {
         address->m8[i] = frame[IEEE802154_DSTADDR_OFFSET + (sizeof(otExtAddress) - 1 - i)];
     }
 }

 static uint16_t crc16_citt(uint16_t aFcs, uint8_t aByte)
 {
     // CRC-16/CCITT, CRC-16/CCITT-TRUE, CRC-CCITT
     // width=16 poly=0x1021 init=0x0000 refin=true refout=true xorout=0x0000 check=0x2189 name="KERMIT"
     // http://reveng.sourceforge.net/crc-catalogue/16.htm#crc.cat.kermit
     static const uint16_t sFcsTable[256] =
     {
         0x0000, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf,
         0x8c48, 0x9dc1, 0xaf5a, 0xbed3, 0xca6c, 0xdbe5, 0xe97e, 0xf8f7,
         0x1081, 0x0108, 0x3393, 0x221a, 0x56a5, 0x472c, 0x75b7, 0x643e,
         0x9cc9, 0x8d40, 0xbfdb, 0xae52, 0xdaed, 0xcb64, 0xf9ff, 0xe876,
         0x2102, 0x308b, 0x0210, 0x1399, 0x6726, 0x76af, 0x4434, 0x55bd,
         0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e, 0xfae7, 0xc87c, 0xd9f5,
         0x3183, 0x200a, 0x1291, 0x0318, 0x77a7, 0x662e, 0x54b5, 0x453c,
         0xbdcb, 0xac42, 0x9ed9, 0x8f50, 0xfbef, 0xea66, 0xd8fd, 0xc974,
         0x4204, 0x538d, 0x6116, 0x709f, 0x0420, 0x15a9, 0x2732, 0x36bb,
         0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868, 0x99e1, 0xab7a, 0xbaf3,
         0x5285, 0x430c, 0x7197, 0x601e, 0x14a1, 0x0528, 0x37b3, 0x263a,
         0xdecd, 0xcf44, 0xfddf, 0xec56, 0x98e9, 0x8960, 0xbbfb, 0xaa72,
         0x6306, 0x728f, 0x4014, 0x519d, 0x2522, 0x34ab, 0x0630, 0x17b9,
         0xef4e, 0xfec7, 0xcc5c, 0xddd5, 0xa96a, 0xb8e3, 0x8a78, 0x9bf1,
         0x7387, 0x620e, 0x5095, 0x411c, 0x35a3, 0x242a, 0x16b1, 0x0738,
         0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb, 0xa862, 0x9af9, 0x8b70,
         0x8408, 0x9581, 0xa71a, 0xb693, 0xc22c, 0xd3a5, 0xe13e, 0xf0b7,
         0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64, 0x5fed, 0x6d76, 0x7cff,
         0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad, 0xc324, 0xf1bf, 0xe036,
         0x18c1, 0x0948, 0x3bd3, 0x2a5a, 0x5ee5, 0x4f6c, 0x7df7, 0x6c7e,
         0xa50a, 0xb483, 0x8618, 0x9791, 0xe32e, 0xf2a7, 0xc03c, 0xd1b5,
         0x2942, 0x38cb, 0x0a50, 0x1bd9, 0x6f66, 0x7eef, 0x4c74, 0x5dfd,
         0xb58b, 0xa402, 0x9699, 0x8710, 0xf3af, 0xe226, 0xd0bd, 0xc134,
         0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7, 0x6e6e, 0x5cf5, 0x4d7c,
         0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028, 0x91a1, 0xa33a, 0xb2b3,
         0x4a44, 0x5bcd, 0x6956, 0x78df, 0x0c60, 0x1de9, 0x2f72, 0x3efb,
         0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9, 0x8120, 0xb3bb, 0xa232,
         0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1, 0x0d68, 0x3ff3, 0x2e7a,
         0xe70e, 0xf687, 0xc41c, 0xd595, 0xa12a, 0xb0a3, 0x8238, 0x93b1,
         0x6b46, 0x7acf, 0x4854, 0x59dd, 0x2d62, 0x3ceb, 0x0e70, 0x1ff9,
         0xf78f, 0xe606, 0xd49d, 0xc514, 0xb1ab, 0xa022, 0x92b9, 0x8330,
         0x7bc7, 0x6a4e, 0x58d5, 0x495c, 0x3de3, 0x2c6a, 0x1ef1, 0x0f78
     };
     return (aFcs >> 8) ^ sFcsTable[(aFcs ^ aByte) & 0xff];
 }

 void otPlatRadioGetIeeeEui64(otInstance *aInstance, uint8_t *aIeeeEui64)
 {
     (void)aInstance;
     aIeeeEui64[0] = 0x18;
     aIeeeEui64[1] = 0xb4;
     aIeeeEui64[2] = 0x30;
     aIeeeEui64[3] = 0x00;
     aIeeeEui64[4] = (NODE_ID >> 24) & 0xff;
     aIeeeEui64[5] = (NODE_ID >> 16) & 0xff;
     aIeeeEui64[6] = (NODE_ID >> 8) & 0xff;
     aIeeeEui64[7] = NODE_ID & 0xff;
 }

 void otPlatRadioSetPanId(otInstance *aInstance, uint16_t panid)
 {
     (void)aInstance;
     sPanid = panid;
 }

 void otPlatRadioSetExtendedAddress(otInstance *aInstance, uint8_t *address)
 {
     (void)aInstance;

     for (size_t i = 0; i < sizeof(sExtendedAddress); i++)
     {
         sExtendedAddress[i] = address[sizeof(sExtendedAddress) - 1 - i];
     }
 }

 void otPlatRadioSetShortAddress(otInstance *aInstance, uint16_t address)
 {
     (void)aInstance;
     sShortAddress = address;
 }

 void otPlatRadioSetPromiscuous(otInstance *aInstance, bool aEnable)
 {
     (void)aInstance;
     sPromiscuous = aEnable;
 }

 void platformRadioInit(void)
 {
     struct sockaddr_in sockaddr;
     char *offset;
     memset(&sockaddr, 0, sizeof(sockaddr));
     sockaddr.sin_family = AF_INET;

     offset = getenv("PORT_OFFSET");

     if (offset)
     {
         char *endptr;

         sPortOffset = (uint16_t)strtol(offset, &endptr, 0);

         if (*endptr != '\0')
         {
             fprintf(stderr, "Invalid PORT_OFFSET: %s\n", offset);
             exit(1);
         }

         sPortOffset *= WELLKNOWN_NODE_ID;
     }

     if (sPromiscuous)
     {
         sockaddr.sin_port = htons(9000 + sPortOffset + WELLKNOWN_NODE_ID);
     }
     else
     {
         sockaddr.sin_port = htons(9000 + sPortOffset + NODE_ID);
     }

     sockaddr.sin_addr.s_addr = INADDR_ANY;

     sSockFd = (int)socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
     bind(sSockFd, (struct sockaddr *)&sockaddr, sizeof(sockaddr));

     sReceiveFrame.mPsdu = sReceiveMessage.mPsdu;
     sTransmitFrame.mPsdu = sTransmitMessage.mPsdu;
     sAckFrame.mPsdu = sAckMessage.mPsdu;
 }

 void platformRadioDeinit(void)
 {
     close(sSockFd);
 }

 bool otPlatRadioIsEnabled(otInstance *aInstance)
 {
     (void)aInstance;
     return (sState != OT_RADIO_STATE_DISABLED) ? true : false;
 }

 otError otPlatRadioEnable(otInstance *aInstance)
 {
     if (!otPlatRadioIsEnabled(aInstance))
     {
         sState = OT_RADIO_STATE_SLEEP;
     }

     return OT_ERROR_NONE;
 }

 otError otPlatRadioDisable(otInstance *aInstance)
 {
     if (otPlatRadioIsEnabled(aInstance))
     {
         sState = OT_RADIO_STATE_DISABLED;
     }

     return OT_ERROR_NONE;
 }

 otError otPlatRadioSleep(otInstance *aInstance)
 {
     otError error = OT_ERROR_INVALID_STATE;
     (void)aInstance;

     if (sState == OT_RADIO_STATE_SLEEP || sState == OT_RADIO_STATE_RECEIVE)
     {
         error = OT_ERROR_NONE;
         sState = OT_RADIO_STATE_SLEEP;
     }

     return error;
 }

 otError otPlatRadioReceive(otInstance *aInstance, uint8_t aChannel)
 {
     otError error = OT_ERROR_INVALID_STATE;
     (void)aInstance;

     if (sState != OT_RADIO_STATE_DISABLED)
     {
         error = OT_ERROR_NONE;
         sState = OT_RADIO_STATE_RECEIVE;
         sAckWait = false;
         sReceiveFrame.mChannel = aChannel;
     }

     return error;
 }

 otError otPlatRadioTransmit(otInstance *aInstance, otRadioFrame *aRadio)
 {
     otError error = OT_ERROR_INVALID_STATE;
     (void)aInstance;
     (void)aRadio;

     if (sState == OT_RADIO_STATE_RECEIVE)
     {
         error = OT_ERROR_NONE;
         sState = OT_RADIO_STATE_TRANSMIT;
     }

     return error;
 }

 otRadioFrame *otPlatRadioGetTransmitBuffer(otInstance *aInstance)
 {
     (void)aInstance;
     return &sTransmitFrame;
 }

 int8_t otPlatRadioGetRssi(otInstance *aInstance)
 {
     (void)aInstance;
     return 0;
 }

 otRadioCaps otPlatRadioGetCaps(otInstance *aInstance)
 {
     (void)aInstance;
     return OT_RADIO_CAPS_NONE;
 }

 bool otPlatRadioGetPromiscuous(otInstance *aInstance)
 {
     (void)aInstance;
     return sPromiscuous;
 }

 void radioReceive(otInstance *aInstance)
 {
     ssize_t rval = recvfrom(sSockFd, (char *)&sReceiveMessage, sizeof(sReceiveMessage), 0, NULL, NULL);

     if (rval < 0)
     {
         perror("recvfrom");
         exit(EXIT_FAILURE);
     }

     sReceiveFrame.mLength = (uint8_t)(rval - 1);

     if (sAckWait &&
         sTransmitFrame.mChannel == sReceiveMessage.mChannel &&
         isFrameTypeAck(sReceiveFrame.mPsdu) &&
         getDsn(sReceiveFrame.mPsdu) == getDsn(sTransmitFrame.mPsdu))
     {
         sState = OT_RADIO_STATE_RECEIVE;
         sAckWait = false;

         otPlatRadioTxDone(aInstance, &sTransmitFrame, &sReceiveFrame, OT_ERROR_NONE);
     }
     else if ((sState == OT_RADIO_STATE_RECEIVE || sState == OT_RADIO_STATE_TRANSMIT) &&
              (sReceiveFrame.mChannel == sReceiveMessage.mChannel))
     {
         radioProcessFrame(aInstance);
     }
 }

 void radioSendMessage(otInstance *aInstance)
 {
     sTransmitMessage.mChannel = sTransmitFrame.mChannel;

     radioTransmit(&sTransmitMessage, &sTransmitFrame);

     sAckWait = isAckRequested(sTransmitFrame.mPsdu);

     if (!sAckWait)
     {
         sState = OT_RADIO_STATE_RECEIVE;

 #if OPENTHREAD_ENABLE_DIAG

         if (otPlatDiagModeGet())
         {
             otPlatDiagRadioTransmitDone(aInstance, &sTransmitFrame, OT_ERROR_NONE);
         }
         else
 #endif
         {
             otPlatRadioTxDone(aInstance, &sTransmitFrame, NULL, OT_ERROR_NONE);
         }
     }
 }

 void platformRadioUpdateFdSet(fd_set *aReadFdSet, fd_set *aWriteFdSet, int *aMaxFd)
 {
     if (aReadFdSet != NULL && (sState != OT_RADIO_STATE_TRANSMIT || sAckWait))
     {
         FD_SET(sSockFd, aReadFdSet);

         if (aMaxFd != NULL && *aMaxFd < sSockFd)
         {
             *aMaxFd = sSockFd;
         }
     }

     if (aWriteFdSet != NULL && sState == OT_RADIO_STATE_TRANSMIT && !sAckWait)
     {
         FD_SET(sSockFd, aWriteFdSet);

         if (aMaxFd != NULL && *aMaxFd < sSockFd)
         {
             *aMaxFd = sSockFd;
         }
     }
 }

 void platformRadioProcess(otInstance *aInstance)
 {
     const int flags = POLLIN | POLLRDNORM | POLLERR | POLLNVAL | POLLHUP;
     struct pollfd pollfd = { sSockFd, flags, 0 };

     if (POLL(&pollfd, 1, 0) > 0 && (pollfd.revents & flags) != 0)
     {
         radioReceive(aInstance);
     }

     if (sState == OT_RADIO_STATE_TRANSMIT && !sAckWait)
     {
         radioSendMessage(aInstance);
     }
 }

 void radioTransmit(struct RadioMessage *msg, const struct otRadioFrame *pkt)
 {
     uint32_t i;
     struct sockaddr_in sockaddr;

     uint16_t crc = 0;
     uint16_t crc_offset = pkt->mLength - sizeof(uint16_t);

     for (i = 0; i < crc_offset; i++)
     {
         crc = crc16_citt(crc, msg->mPsdu[i]);
     }

     msg->mPsdu[crc_offset] = crc & 0xff;
     msg->mPsdu[crc_offset + 1] = crc >> 8;

     memset(&sockaddr, 0, sizeof(sockaddr));
     sockaddr.sin_family = AF_INET;
     inet_pton(AF_INET, "127.0.0.1", &sockaddr.sin_addr);

     for (i = 1; i <= WELLKNOWN_NODE_ID; i++)
     {
         ssize_t rval;

         if (NODE_ID == i)
         {
             continue;
         }

         sockaddr.sin_port = htons(9000 + sPortOffset + i);
         rval = sendto(sSockFd, (const char *)msg, 1 + pkt->mLength,
                       0, (struct sockaddr *)&sockaddr, sizeof(sockaddr));

         if (rval < 0)
         {
             perror("recvfrom");
             exit(EXIT_FAILURE);
         }
     }
 }

 void radioSendAck(void)
 {
     sAckFrame.mLength = IEEE802154_ACK_LENGTH;
     sAckMessage.mPsdu[0] = IEEE802154_FRAME_TYPE_ACK;

     if (isDataRequest(sReceiveFrame.mPsdu))
     {
         sAckMessage.mPsdu[0] |= IEEE802154_FRAME_PENDING;
     }

     sAckMessage.mPsdu[1] = 0;
     sAckMessage.mPsdu[2] = getDsn(sReceiveFrame.mPsdu);

     sAckMessage.mChannel = sReceiveFrame.mChannel;

     radioTransmit(&sAckMessage, &sAckFrame);
 }

 void radioProcessFrame(otInstance *aInstance)
 {
     otError error = OT_ERROR_NONE;
     otPanId dstpan;
     otShortAddress short_address;
     otExtAddress ext_address;

     otEXPECT_ACTION(sPromiscuous == false, error = OT_ERROR_NONE);

     switch (sReceiveFrame.mPsdu[1] & IEEE802154_DST_ADDR_MASK)
     {
     case IEEE802154_DST_ADDR_NONE:
         break;

     case IEEE802154_DST_ADDR_SHORT:
         dstpan = getDstPan(sReceiveFrame.mPsdu);
         short_address = getShortAddress(sReceiveFrame.mPsdu);
         otEXPECT_ACTION((dstpan == IEEE802154_BROADCAST || dstpan == sPanid) &&
                         (short_address == IEEE802154_BROADCAST || short_address == sShortAddress),
                         error = OT_ERROR_ABORT);
         break;

     case IEEE802154_DST_ADDR_EXT:
         dstpan = getDstPan(sReceiveFrame.mPsdu);
         getExtAddress(sReceiveFrame.mPsdu, &ext_address);
         otEXPECT_ACTION((dstpan == IEEE802154_BROADCAST || dstpan == sPanid) &&
                         memcmp(&ext_address, sExtendedAddress, sizeof(ext_address)) == 0,
                         error = OT_ERROR_ABORT);
         break;

     default:
         error = OT_ERROR_ABORT;
         goto exit;
     }

     sReceiveFrame.mPower = -20;
     sReceiveFrame.mLqi = OT_RADIO_LQI_NONE;

     // generate acknowledgment
     if (isAckRequested(sReceiveFrame.mPsdu))
     {
         radioSendAck();
     }

 exit:

 #if OPENTHREAD_ENABLE_DIAG

     if (otPlatDiagModeGet())
     {
         otPlatDiagRadioReceiveDone(aInstance, error == OT_ERROR_NONE ? &sReceiveFrame : NULL, error);
     }
     else
 #endif
     {
         otPlatRadioReceiveDone(aInstance, error == OT_ERROR_NONE ? &sReceiveFrame : NULL, error);
     }
 }

 void otPlatRadioEnableSrcMatch(otInstance *aInstance, bool aEnable)
 {
     (void)aInstance;
     (void)aEnable;
 }

 otError otPlatRadioAddSrcMatchShortEntry(otInstance *aInstance, const uint16_t aShortAddress)
 {
     (void)aInstance;
     (void)aShortAddress;
     return OT_ERROR_NONE;
 }

 otError otPlatRadioAddSrcMatchExtEntry(otInstance *aInstance, const uint8_t *aExtAddress)
 {
     (void)aInstance;
     (void)aExtAddress;
     return OT_ERROR_NONE;
 }

 otError otPlatRadioClearSrcMatchShortEntry(otInstance *aInstance, const uint16_t aShortAddress)
 {
     (void)aInstance;
     (void)aShortAddress;
     return OT_ERROR_NONE;
 }

 otError otPlatRadioClearSrcMatchExtEntry(otInstance *aInstance, const uint8_t *aExtAddress)
 {
     (void)aInstance;
     (void)aExtAddress;
     return OT_ERROR_NONE;
 }

 void otPlatRadioClearSrcMatchShortEntries(otInstance *aInstance)
 {
     (void)aInstance;
 }

 void otPlatRadioClearSrcMatchExtEntries(otInstance *aInstance)
 {
     (void)aInstance;
 }

 otError otPlatRadioEnergyScan(otInstance *aInstance, uint8_t aScanChannel, uint16_t aScanDuration)
 {
     (void)aInstance;
     (void)aScanChannel;
     (void)aScanDuration;
     return OT_ERROR_NOT_IMPLEMENTED;
 }

 void otPlatRadioSetDefaultTxPower(otInstance *aInstance, int8_t aPower)
 {
     (void)aInstance;
     (void)aPower;
 }

 int8_t otPlatRadioGetReceiveSensitivity(otInstance *aInstance)
 {
     (void)aInstance;
     return POSIX_RECEIVE_SENSITIVITY;
 }
	/*
	* Copyright (c) 2016, The OpenThread Authors.
	* All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions are met:
	* 1. Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* 2. Redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in the
	* documentation and/or other materials provided with the distribution.
	* 3. Neither the name of the copyright holder nor the
	* names of its contributors may be used to endorse or promote products
	* derived from this software without specific prior written permission.
	*
	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
	* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
	* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
	* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
	* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
	* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
	* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
	* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
	* POSSIBILITY OF SUCH DAMAGE.
	*/

	#include "platform-posix.h"

	#include <openthread/platform/diag.h>
	#include <openthread/platform/radio.h>

	#include "utils/code_utils.h"

	enum
	{
	IEEE802154_MIN_LENGTH = 5,
	IEEE802154_MAX_LENGTH = 127,
	IEEE802154_ACK_LENGTH = 5,

	IEEE802154_BROADCAST = 0xffff,

	IEEE802154_FRAME_TYPE_ACK = 2 << 0,
	IEEE802154_FRAME_TYPE_MACCMD = 3 << 0,
	IEEE802154_FRAME_TYPE_MASK = 7 << 0,

	IEEE802154_SECURITY_ENABLED = 1 << 3,
	IEEE802154_FRAME_PENDING = 1 << 4,
	IEEE802154_ACK_REQUEST = 1 << 5,
	IEEE802154_PANID_COMPRESSION = 1 << 6,

	IEEE802154_DST_ADDR_NONE = 0 << 2,
	IEEE802154_DST_ADDR_SHORT = 2 << 2,
	IEEE802154_DST_ADDR_EXT = 3 << 2,
	IEEE802154_DST_ADDR_MASK = 3 << 2,

	IEEE802154_SRC_ADDR_NONE = 0 << 6,
	IEEE802154_SRC_ADDR_SHORT = 2 << 6,
	IEEE802154_SRC_ADDR_EXT = 3 << 6,
	IEEE802154_SRC_ADDR_MASK = 3 << 6,

	IEEE802154_DSN_OFFSET = 2,
	IEEE802154_DSTPAN_OFFSET = 3,
	IEEE802154_DSTADDR_OFFSET = 5,

	IEEE802154_SEC_LEVEL_MASK = 7 << 0,

	IEEE802154_KEY_ID_MODE_0 = 0 << 3,
	IEEE802154_KEY_ID_MODE_1 = 1 << 3,
	IEEE802154_KEY_ID_MODE_2 = 2 << 3,
	IEEE802154_KEY_ID_MODE_3 = 3 << 3,
	IEEE802154_KEY_ID_MODE_MASK = 3 << 3,

	IEEE802154_MACCMD_DATA_REQ = 4,
	};

	enum
	{
	POSIX_RECEIVE_SENSITIVITY = -100, // dBm
	};

	OT_TOOL_PACKED_BEGIN
	struct RadioMessage
	{
	uint8_t mChannel;
	uint8_t mPsdu[OT_RADIO_FRAME_MAX_SIZE];
	} OT_TOOL_PACKED_END;

	static void radioTransmit(struct RadioMessage msg, const struct otRadioFrame pkt);
	static void radioSendMessage(otInstance *aInstance);
	static void radioSendAck(void);
	static void radioProcessFrame(otInstance *aInstance);

	static otRadioState sState = OT_RADIO_STATE_DISABLED;
	static struct RadioMessage sReceiveMessage;
	static struct RadioMessage sTransmitMessage;
	static struct RadioMessage sAckMessage;
	static otRadioFrame sReceiveFrame;
	static otRadioFrame sTransmitFrame;
	static otRadioFrame sAckFrame;

	static uint8_t sExtendedAddress[OT_EXT_ADDRESS_SIZE];
	static uint16_t sShortAddress;
	static uint16_t sPanid;
	static int sSockFd;
	static bool sPromiscuous = false;
	static bool sAckWait = false;
	static uint16_t sPortOffset = 0;

	static inline bool isFrameTypeAck(const uint8_t *frame)
	{
	return (frame[0] & IEEE802154_FRAME_TYPE_MASK) == IEEE802154_FRAME_TYPE_ACK;
	}

	static inline bool isFrameTypeMacCmd(const uint8_t *frame)
	{
	return (frame[0] & IEEE802154_FRAME_TYPE_MASK) == IEEE802154_FRAME_TYPE_MACCMD;
	}

	static inline bool isSecurityEnabled(const uint8_t *frame)
	{
	return (frame[0] & IEEE802154_SECURITY_ENABLED) != 0;
	}

	static inline bool isAckRequested(const uint8_t *frame)
	{
	return (frame[0] & IEEE802154_ACK_REQUEST) != 0;
	}

	static inline bool isPanIdCompressed(const uint8_t *frame)
	{
	return (frame[0] & IEEE802154_PANID_COMPRESSION) != 0;
	}

	static inline bool isDataRequest(const uint8_t *frame)
	{
	const uint8_t *cur = frame;
	uint8_t securityControl;
	bool rval;

	// FCF + DSN
	cur += 2 + 1;

	otEXPECT_ACTION(isFrameTypeMacCmd(frame), rval = false);

	// Destination PAN + Address
	switch (frame[1] & IEEE802154_DST_ADDR_MASK)
	{
	case IEEE802154_DST_ADDR_SHORT:
	cur += sizeof(otPanId) + sizeof(otShortAddress);
	break;

	case IEEE802154_DST_ADDR_EXT:
	cur += sizeof(otPanId) + sizeof(otExtAddress);
	break;

	default:
	rval = false;
	goto exit;
	}

	// Source PAN + Address
	switch (frame[1] & IEEE802154_SRC_ADDR_MASK)
	{
	case IEEE802154_SRC_ADDR_SHORT:
	if (!isPanIdCompressed(frame))
	{
	cur += sizeof(otPanId);
	}

	cur += sizeof(otShortAddress);
	break;

	case IEEE802154_SRC_ADDR_EXT:
	if (!isPanIdCompressed(frame))
	{
	cur += sizeof(otPanId);
	}

	cur += sizeof(otExtAddress);
	break;

	default:
	rval = false;
	goto exit;
	}

	// Security Control + Frame Counter + Key Identifier
	if (isSecurityEnabled(frame))
	{
	securityControl = *cur;

	if (securityControl & IEEE802154_SEC_LEVEL_MASK)
	{
	cur += 1 + 4;
	}

	switch (securityControl & IEEE802154_KEY_ID_MODE_MASK)
	{
	case IEEE802154_KEY_ID_MODE_0:
	cur += 0;
	break;

	case IEEE802154_KEY_ID_MODE_1:
	cur += 1;
	break;

	case IEEE802154_KEY_ID_MODE_2:
	cur += 5;
	break;

	case IEEE802154_KEY_ID_MODE_3:
	cur += 9;
	break;
	}
	}

	// Command ID
	rval = cur[0] == IEEE802154_MACCMD_DATA_REQ;

	exit:
	return rval;
	}

	static inline uint8_t getDsn(const uint8_t *frame)
	{
	return frame[IEEE802154_DSN_OFFSET];
	}

	static inline otPanId getDstPan(const uint8_t *frame)
	{
	return (otPanId)((frame[IEEE802154_DSTPAN_OFFSET + 1] << 8) \| frame[IEEE802154_DSTPAN_OFFSET]);
	}

	static inline otShortAddress getShortAddress(const uint8_t *frame)
	{
	return (otShortAddress)((frame[IEEE802154_DSTADDR_OFFSET + 1] << 8) \| frame[IEEE802154_DSTADDR_OFFSET]);
	}

	static inline void getExtAddress(const uint8_t frame, otExtAddress address)
	{
	size_t i;

	for (i = 0; i < sizeof(otExtAddress); i++)
	{
	address->m8[i] = frame[IEEE802154_DSTADDR_OFFSET + (sizeof(otExtAddress) - 1 - i)];
	}
	}

	static uint16_t crc16_citt(uint16_t aFcs, uint8_t aByte)
	{
	// CRC-16/CCITT, CRC-16/CCITT-TRUE, CRC-CCITT
	// width=16 poly=0x1021 init=0x0000 refin=true refout=true xorout=0x0000 check=0x2189 name="KERMIT"
	// http://reveng.sourceforge.net/crc-catalogue/16.htm#crc.cat.kermit
	static const uint16_t sFcsTable[256] =
	{
	0x0000, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf,
	0x8c48, 0x9dc1, 0xaf5a, 0xbed3, 0xca6c, 0xdbe5, 0xe97e, 0xf8f7,
	0x1081, 0x0108, 0x3393, 0x221a, 0x56a5, 0x472c, 0x75b7, 0x643e,
	0x9cc9, 0x8d40, 0xbfdb, 0xae52, 0xdaed, 0xcb64, 0xf9ff, 0xe876,
	0x2102, 0x308b, 0x0210, 0x1399, 0x6726, 0x76af, 0x4434, 0x55bd,
	0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e, 0xfae7, 0xc87c, 0xd9f5,
	0x3183, 0x200a, 0x1291, 0x0318, 0x77a7, 0x662e, 0x54b5, 0x453c,
	0xbdcb, 0xac42, 0x9ed9, 0x8f50, 0xfbef, 0xea66, 0xd8fd, 0xc974,
	0x4204, 0x538d, 0x6116, 0x709f, 0x0420, 0x15a9, 0x2732, 0x36bb,
	0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868, 0x99e1, 0xab7a, 0xbaf3,
	0x5285, 0x430c, 0x7197, 0x601e, 0x14a1, 0x0528, 0x37b3, 0x263a,
	0xdecd, 0xcf44, 0xfddf, 0xec56, 0x98e9, 0x8960, 0xbbfb, 0xaa72,
	0x6306, 0x728f, 0x4014, 0x519d, 0x2522, 0x34ab, 0x0630, 0x17b9,
	0xef4e, 0xfec7, 0xcc5c, 0xddd5, 0xa96a, 0xb8e3, 0x8a78, 0x9bf1,
	0x7387, 0x620e, 0x5095, 0x411c, 0x35a3, 0x242a, 0x16b1, 0x0738,
	0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb, 0xa862, 0x9af9, 0x8b70,
	0x8408, 0x9581, 0xa71a, 0xb693, 0xc22c, 0xd3a5, 0xe13e, 0xf0b7,
	0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64, 0x5fed, 0x6d76, 0x7cff,
	0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad, 0xc324, 0xf1bf, 0xe036,
	0x18c1, 0x0948, 0x3bd3, 0x2a5a, 0x5ee5, 0x4f6c, 0x7df7, 0x6c7e,
	0xa50a, 0xb483, 0x8618, 0x9791, 0xe32e, 0xf2a7, 0xc03c, 0xd1b5,
	0x2942, 0x38cb, 0x0a50, 0x1bd9, 0x6f66, 0x7eef, 0x4c74, 0x5dfd,
	0xb58b, 0xa402, 0x9699, 0x8710, 0xf3af, 0xe226, 0xd0bd, 0xc134,
	0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7, 0x6e6e, 0x5cf5, 0x4d7c,
	0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028, 0x91a1, 0xa33a, 0xb2b3,
	0x4a44, 0x5bcd, 0x6956, 0x78df, 0x0c60, 0x1de9, 0x2f72, 0x3efb,
	0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9, 0x8120, 0xb3bb, 0xa232,
	0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1, 0x0d68, 0x3ff3, 0x2e7a,
	0xe70e, 0xf687, 0xc41c, 0xd595, 0xa12a, 0xb0a3, 0x8238, 0x93b1,
	0x6b46, 0x7acf, 0x4854, 0x59dd, 0x2d62, 0x3ceb, 0x0e70, 0x1ff9,
	0xf78f, 0xe606, 0xd49d, 0xc514, 0xb1ab, 0xa022, 0x92b9, 0x8330,
	0x7bc7, 0x6a4e, 0x58d5, 0x495c, 0x3de3, 0x2c6a, 0x1ef1, 0x0f78
	};
	return (aFcs >> 8) ^ sFcsTable[(aFcs ^ aByte) & 0xff];
	}

	void otPlatRadioGetIeeeEui64(otInstance aInstance, uint8_t aIeeeEui64)
	{
	(void)aInstance;
	aIeeeEui64[0] = 0x18;
	aIeeeEui64[1] = 0xb4;
	aIeeeEui64[2] = 0x30;
	aIeeeEui64[3] = 0x00;
	aIeeeEui64[4] = (NODE_ID >> 24) & 0xff;
	aIeeeEui64[5] = (NODE_ID >> 16) & 0xff;
	aIeeeEui64[6] = (NODE_ID >> 8) & 0xff;
	aIeeeEui64[7] = NODE_ID & 0xff;
	}

	void otPlatRadioSetPanId(otInstance *aInstance, uint16_t panid)
	{
	(void)aInstance;
	sPanid = panid;
	}

	void otPlatRadioSetExtendedAddress(otInstance aInstance, uint8_t address)
	{
	(void)aInstance;

	for (size_t i = 0; i < sizeof(sExtendedAddress); i++)
	{
	sExtendedAddress[i] = address[sizeof(sExtendedAddress) - 1 - i];
	}
	}

	void otPlatRadioSetShortAddress(otInstance *aInstance, uint16_t address)
	{
	(void)aInstance;
	sShortAddress = address;
	}

	void otPlatRadioSetPromiscuous(otInstance *aInstance, bool aEnable)
	{
	(void)aInstance;
	sPromiscuous = aEnable;
	}

	void platformRadioInit(void)
	{
	struct sockaddr_in sockaddr;
	char *offset;
	memset(&sockaddr, 0, sizeof(sockaddr));
	sockaddr.sin_family = AF_INET;

	offset = getenv("PORT_OFFSET");

	if (offset)
	{
	char *endptr;

	sPortOffset = (uint16_t)strtol(offset, &endptr, 0);

	if (*endptr != '\0')
	{
	fprintf(stderr, "Invalid PORT_OFFSET: %s\n", offset);
	exit(1);
	}

	sPortOffset *= WELLKNOWN_NODE_ID;
	}

	if (sPromiscuous)
	{
	sockaddr.sin_port = htons(9000 + sPortOffset + WELLKNOWN_NODE_ID);
	}
	else
	{
	sockaddr.sin_port = htons(9000 + sPortOffset + NODE_ID);
	}

	sockaddr.sin_addr.s_addr = INADDR_ANY;

	sSockFd = (int)socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
	bind(sSockFd, (struct sockaddr *)&sockaddr, sizeof(sockaddr));

	sReceiveFrame.mPsdu = sReceiveMessage.mPsdu;
	sTransmitFrame.mPsdu = sTransmitMessage.mPsdu;
	sAckFrame.mPsdu = sAckMessage.mPsdu;
	}

	void platformRadioDeinit(void)
	{
	close(sSockFd);
	}

	bool otPlatRadioIsEnabled(otInstance *aInstance)
	{
	(void)aInstance;
	return (sState != OT_RADIO_STATE_DISABLED) ? true : false;
	}

	otError otPlatRadioEnable(otInstance *aInstance)
	{
	if (!otPlatRadioIsEnabled(aInstance))
	{
	sState = OT_RADIO_STATE_SLEEP;
	}

	return OT_ERROR_NONE;
	}

	otError otPlatRadioDisable(otInstance *aInstance)
	{
	if (otPlatRadioIsEnabled(aInstance))
	{
	sState = OT_RADIO_STATE_DISABLED;
	}

	return OT_ERROR_NONE;
	}

	otError otPlatRadioSleep(otInstance *aInstance)
	{
	otError error = OT_ERROR_INVALID_STATE;
	(void)aInstance;

	if (sState == OT_RADIO_STATE_SLEEP \|\| sState == OT_RADIO_STATE_RECEIVE)
	{
	error = OT_ERROR_NONE;
	sState = OT_RADIO_STATE_SLEEP;
	}

	return error;
	}

	otError otPlatRadioReceive(otInstance *aInstance, uint8_t aChannel)
	{
	otError error = OT_ERROR_INVALID_STATE;
	(void)aInstance;

	if (sState != OT_RADIO_STATE_DISABLED)
	{
	error = OT_ERROR_NONE;
	sState = OT_RADIO_STATE_RECEIVE;
	sAckWait = false;
	sReceiveFrame.mChannel = aChannel;
	}

	return error;
	}

	otError otPlatRadioTransmit(otInstance aInstance, otRadioFrame aRadio)
	{
	otError error = OT_ERROR_INVALID_STATE;
	(void)aInstance;
	(void)aRadio;

	if (sState == OT_RADIO_STATE_RECEIVE)
	{
	error = OT_ERROR_NONE;
	sState = OT_RADIO_STATE_TRANSMIT;
	}

	return error;
	}

	otRadioFrame otPlatRadioGetTransmitBuffer(otInstance aInstance)
	{
	(void)aInstance;
	return &sTransmitFrame;
	}

	int8_t otPlatRadioGetRssi(otInstance *aInstance)
	{
	(void)aInstance;
	return 0;
	}

	otRadioCaps otPlatRadioGetCaps(otInstance *aInstance)
	{
	(void)aInstance;
	return OT_RADIO_CAPS_NONE;
	}

	bool otPlatRadioGetPromiscuous(otInstance *aInstance)
	{
	(void)aInstance;
	return sPromiscuous;
	}

	void radioReceive(otInstance *aInstance)
	{
	ssize_t rval = recvfrom(sSockFd, (char *)&sReceiveMessage, sizeof(sReceiveMessage), 0, NULL, NULL);

	if (rval < 0)
	{
	perror("recvfrom");
	exit(EXIT_FAILURE);
	}

	sReceiveFrame.mLength = (uint8_t)(rval - 1);

	if (sAckWait &&
	sTransmitFrame.mChannel == sReceiveMessage.mChannel &&
	isFrameTypeAck(sReceiveFrame.mPsdu) &&
	getDsn(sReceiveFrame.mPsdu) == getDsn(sTransmitFrame.mPsdu))
	{
	sState = OT_RADIO_STATE_RECEIVE;
	sAckWait = false;

	otPlatRadioTxDone(aInstance, &sTransmitFrame, &sReceiveFrame, OT_ERROR_NONE);
	}
	else if ((sState == OT_RADIO_STATE_RECEIVE \|\| sState == OT_RADIO_STATE_TRANSMIT) &&
	(sReceiveFrame.mChannel == sReceiveMessage.mChannel))
	{
	radioProcessFrame(aInstance);
	}
	}

	void radioSendMessage(otInstance *aInstance)
	{
	sTransmitMessage.mChannel = sTransmitFrame.mChannel;

	radioTransmit(&sTransmitMessage, &sTransmitFrame);

	sAckWait = isAckRequested(sTransmitFrame.mPsdu);

	if (!sAckWait)
	{
	sState = OT_RADIO_STATE_RECEIVE;

	#if OPENTHREAD_ENABLE_DIAG

	if (otPlatDiagModeGet())
	{
	otPlatDiagRadioTransmitDone(aInstance, &sTransmitFrame, OT_ERROR_NONE);
	}
	else
	#endif
	{
	otPlatRadioTxDone(aInstance, &sTransmitFrame, NULL, OT_ERROR_NONE);
	}
	}
	}

	void platformRadioUpdateFdSet(fd_set aReadFdSet, fd_set aWriteFdSet, int *aMaxFd)
	{
	if (aReadFdSet != NULL && (sState != OT_RADIO_STATE_TRANSMIT \|\| sAckWait))
	{
	FD_SET(sSockFd, aReadFdSet);

	if (aMaxFd != NULL && *aMaxFd < sSockFd)
	{
	*aMaxFd = sSockFd;
	}
	}

	if (aWriteFdSet != NULL && sState == OT_RADIO_STATE_TRANSMIT && !sAckWait)
	{
	FD_SET(sSockFd, aWriteFdSet);

	if (aMaxFd != NULL && *aMaxFd < sSockFd)
	{
	*aMaxFd = sSockFd;
	}
	}
	}

	void platformRadioProcess(otInstance *aInstance)
	{
	const int flags = POLLIN \| POLLRDNORM \| POLLERR \| POLLNVAL \| POLLHUP;
	struct pollfd pollfd = { sSockFd, flags, 0 };

	if (POLL(&pollfd, 1, 0) > 0 && (pollfd.revents & flags) != 0)
	{
	radioReceive(aInstance);
	}

	if (sState == OT_RADIO_STATE_TRANSMIT && !sAckWait)
	{
	radioSendMessage(aInstance);
	}
	}

	void radioTransmit(struct RadioMessage msg, const struct otRadioFrame pkt)
	{
	uint32_t i;
	struct sockaddr_in sockaddr;

	uint16_t crc = 0;
	uint16_t crc_offset = pkt->mLength - sizeof(uint16_t);

	for (i = 0; i < crc_offset; i++)
	{
	crc = crc16_citt(crc, msg->mPsdu[i]);
	}

	msg->mPsdu[crc_offset] = crc & 0xff;
	msg->mPsdu[crc_offset + 1] = crc >> 8;

	memset(&sockaddr, 0, sizeof(sockaddr));
	sockaddr.sin_family = AF_INET;
	inet_pton(AF_INET, "127.0.0.1", &sockaddr.sin_addr);

	for (i = 1; i <= WELLKNOWN_NODE_ID; i++)
	{
	ssize_t rval;

	if (NODE_ID == i)
	{
	continue;
	}

	sockaddr.sin_port = htons(9000 + sPortOffset + i);
	rval = sendto(sSockFd, (const char *)msg, 1 + pkt->mLength,
	0, (struct sockaddr *)&sockaddr, sizeof(sockaddr));

	if (rval < 0)
	{
	perror("recvfrom");
	exit(EXIT_FAILURE);
	}
	}
	}

	void radioSendAck(void)
	{
	sAckFrame.mLength = IEEE802154_ACK_LENGTH;
	sAckMessage.mPsdu[0] = IEEE802154_FRAME_TYPE_ACK;

	if (isDataRequest(sReceiveFrame.mPsdu))
	{
	sAckMessage.mPsdu[0] \|= IEEE802154_FRAME_PENDING;
	}

	sAckMessage.mPsdu[1] = 0;
	sAckMessage.mPsdu[2] = getDsn(sReceiveFrame.mPsdu);

	sAckMessage.mChannel = sReceiveFrame.mChannel;

	radioTransmit(&sAckMessage, &sAckFrame);
	}

	void radioProcessFrame(otInstance *aInstance)
	{
	otError error = OT_ERROR_NONE;
	otPanId dstpan;
	otShortAddress short_address;
	otExtAddress ext_address;

	otEXPECT_ACTION(sPromiscuous == false, error = OT_ERROR_NONE);

	switch (sReceiveFrame.mPsdu[1] & IEEE802154_DST_ADDR_MASK)
	{
	case IEEE802154_DST_ADDR_NONE:
	break;

	case IEEE802154_DST_ADDR_SHORT:
	dstpan = getDstPan(sReceiveFrame.mPsdu);
	short_address = getShortAddress(sReceiveFrame.mPsdu);
	otEXPECT_ACTION((dstpan == IEEE802154_BROADCAST \|\| dstpan == sPanid) &&
	(short_address == IEEE802154_BROADCAST \|\| short_address == sShortAddress),
	error = OT_ERROR_ABORT);
	break;

	case IEEE802154_DST_ADDR_EXT:
	dstpan = getDstPan(sReceiveFrame.mPsdu);
	getExtAddress(sReceiveFrame.mPsdu, &ext_address);
	otEXPECT_ACTION((dstpan == IEEE802154_BROADCAST \|\| dstpan == sPanid) &&
	memcmp(&ext_address, sExtendedAddress, sizeof(ext_address)) == 0,
	error = OT_ERROR_ABORT);
	break;

	default:
	error = OT_ERROR_ABORT;
	goto exit;
	}

	sReceiveFrame.mPower = -20;
	sReceiveFrame.mLqi = OT_RADIO_LQI_NONE;

	// generate acknowledgment
	if (isAckRequested(sReceiveFrame.mPsdu))
	{
	radioSendAck();
	}

	exit:

	#if OPENTHREAD_ENABLE_DIAG

	if (otPlatDiagModeGet())
	{
	otPlatDiagRadioReceiveDone(aInstance, error == OT_ERROR_NONE ? &sReceiveFrame : NULL, error);
	}
	else
	#endif
	{
	otPlatRadioReceiveDone(aInstance, error == OT_ERROR_NONE ? &sReceiveFrame : NULL, error);
	}
	}

	void otPlatRadioEnableSrcMatch(otInstance *aInstance, bool aEnable)
	{
	(void)aInstance;
	(void)aEnable;
	}

	otError otPlatRadioAddSrcMatchShortEntry(otInstance *aInstance, const uint16_t aShortAddress)
	{
	(void)aInstance;
	(void)aShortAddress;
	return OT_ERROR_NONE;
	}

	otError otPlatRadioAddSrcMatchExtEntry(otInstance aInstance, const uint8_t aExtAddress)
	{
	(void)aInstance;
	(void)aExtAddress;
	return OT_ERROR_NONE;
	}

	otError otPlatRadioClearSrcMatchShortEntry(otInstance *aInstance, const uint16_t aShortAddress)
	{
	(void)aInstance;
	(void)aShortAddress;
	return OT_ERROR_NONE;
	}

	otError otPlatRadioClearSrcMatchExtEntry(otInstance aInstance, const uint8_t aExtAddress)
	{
	(void)aInstance;
	(void)aExtAddress;
	return OT_ERROR_NONE;
	}

	void otPlatRadioClearSrcMatchShortEntries(otInstance *aInstance)
	{
	(void)aInstance;
	}

	void otPlatRadioClearSrcMatchExtEntries(otInstance *aInstance)
	{
	(void)aInstance;
	}

	otError otPlatRadioEnergyScan(otInstance *aInstance, uint8_t aScanChannel, uint16_t aScanDuration)
	{
	(void)aInstance;
	(void)aScanChannel;
	(void)aScanDuration;
	return OT_ERROR_NOT_IMPLEMENTED;
	}

	void otPlatRadioSetDefaultTxPower(otInstance *aInstance, int8_t aPower)
	{
	(void)aInstance;
	(void)aPower;
	}

	int8_t otPlatRadioGetReceiveSensitivity(otInstance *aInstance)
	{
	(void)aInstance;
	return POSIX_RECEIVE_SENSITIVITY;
	}