自学教程：C++ uip_arp_out函数代码示例

void Test_uip_arp_arpout(CuTest *tc) {	u8_t temp_buf[]= "/x11/x22/x33/x44/x55/x66/x77/x88/x99/x00/xAA/xBB/x08/x00"	"/x45"  //ipv4, 4*5=20byte	"/x00"	"/x00/x14" //fra	"/x00/x00"	"/x00/x00"	"/x11" //ttl	"/x06" //tcp	"/x00/x00"  //header checksum,dont fit now	"/xC0/xA8/x00/x02"	"/xff/xff/xff/x00" //ip broadcast,subnet broad cast	"/x00/x00/x00/x00/x00/x00/x00/x00/x00/x00/x00/x00/x00/x00/x00/x00"	"/x00/x00/x00/x00/x00/x00/x00/x00/x00/x00/x00/x00/x00/x00/x00/x00";	iprintf_s(temp_buf,sizeof(temp_buf));	uip_arp_init();	memcpy(uip_buf,temp_buf,60);//broad cast,=dest ip equeals mask	uip_arp_out();    CuAssertHexEquals_Msg(tc,"arp out 1",0xFF,IPBUF->ethhdr.dest.addr[0]);    IPBUF->destipaddr[0]=0xA8C0;    IPBUF->destipaddr[1]=0x0300;    uip_arp_out();    CuAssertHexEquals_Msg(tc,"arp out 2",0xFF,IPBUF->ethhdr.dest.addr[0]);    CuAssertHexEquals_Msg(tc,"arp out 3",0xFF,IPBUF->ethhdr.dest.addr[1]);    CuAssertHexEquals_Msg(tc,"arp out 4",0xFF,IPBUF->ethhdr.dest.addr[2]);    CuAssertHexEquals_Msg(tc,"arp out 5",0xFF,IPBUF->ethhdr.dest.addr[3]);    CuAssertHexEquals_Msg(tc,"arp out 6",0xFF,IPBUF->ethhdr.dest.addr[4]);    CuAssertHexEquals_Msg(tc,"arp out 7",0xFF,IPBUF->ethhdr.dest.addr[5]);    CuAssertHexEquals_Msg(tc,"arp out 8",HTONS(UIP_ETHTYPE_ARP),BUF->ethhdr.type);    CuAssertHexEquals_Msg(tc,"arp out 8",0x0608,BUF->ethhdr.type);}

void tcpip_periodic_timer(){	int i;    MT_TimerExpired();	if(timer_expired(&periodic_timer)) {		timer_reset(&periodic_timer);		for(i = 0; i < UIP_CONNS; i++) {			uip_periodic(i);			/* If the above function invocation resulted in data that			should be sent out on the network, the global variable			uip_len is set to a value > 0. */			if(uip_len > 0) {				uip_arp_out();				mt76xx_dev_send();			}		}#if UIP_UDP		for(i = 0; i < UIP_UDP_CONNS; i++) {			uip_udp_periodic(i);			/* If the above function invocation resulted in data that			should be sent out on the network, the global variable			uip_len is set to a value > 0. */			if(uip_len > 0) {				uip_arp_out();				mt76xx_dev_send();			}		}#endif /* UIP_UDP */		/* Call the ARP timer function every 10 seconds. */		if(timer_expired(&arp_timer)) {			timer_reset(&arp_timer);			uip_arp_timer();		}    }#if 0	if(timer_expired(&cli_timer)) {		clk = (clk > (CLOCK_SECOND*60))?clk:(clk*2);		timer_set(&cli_timer, clk);				if ((cli_fd == -1) && 			memcmp(uip_hostaddr, 0x00000000, sizeof(uip_hostaddr))) {			struct uip_conn *conn = NULL;			uip_ipaddr_t srv_ip;						uip_ipaddr(srv_ip, IoTpAd.ComCfg.IoT_ServeIP[0], IoTpAd.ComCfg.IoT_ServeIP[1],					IoTpAd.ComCfg.IoT_ServeIP[2], IoTpAd.ComCfg.IoT_ServeIP[3]);			conn = uip_connect(&srv_ip, HTONS(IoTpAd.ComCfg.IoT_TCP_Srv_Port));			if(conn) {				conn->lport = HTONS(7682);				cli_fd = conn->fd;			} else {				printf("connect fail/n");			}			}	}#endif	}

void xtcpd_check_connection_poll(chanend mac_tx){	for (int i = 0; i < UIP_CONNS; i++) {		if (uip_conn_needs_poll(&uip_conns[i])) {			uip_poll_conn(&uip_conns[i]);#if UIP_CONF_IPV6            xtcpip_ipv6_output(mac_tx);#else /* UIP_CONF_IPV6 */            if (uip_len > 0) {                uip_arp_out( NULL);                xtcp_tx_buffer(mac_tx);            }#endif /* UIP_CONF_IPV6 */		}	}	for (int i = 0; i < UIP_UDP_CONNS; i++) {		if (uip_udp_conn_needs_poll(&uip_udp_conns[i])) {			uip_udp_periodic(i);#if UIP_CONF_IPV6             xtcpip_ipv6_output(mac_tx);#else            if (uip_len > 0) {                uip_arp_out(&uip_udp_conns[i]);                xtcp_tx_buffer(mac_tx);            }#endif		}	}}

void xtcp_process_incoming_packet(chanend mac_tx){	if (BUF->type == htons(UIP_ETHTYPE_IP)) {		uip_arp_ipin();		uip_input();		if (uip_len > 0) {			if (uip_udpconnection()				&& (TCPBUF->proto != UIP_PROTO_ICMP)				&& (TCPBUF->proto != UIP_PROTO_IGMP))				uip_arp_out( uip_udp_conn);			else				uip_arp_out( NULL);			xtcp_tx_buffer(mac_tx);		}	} else if (BUF->type == htons(UIP_ETHTYPE_ARP)) {		uip_arp_arpin();		if (uip_len > 0) {			xtcp_tx_buffer(mac_tx);		}		for (int i = 0; i < UIP_UDP_CONNS; i++) {			uip_udp_arp_event(i);			if (uip_len > 0) {				uip_arp_out(&uip_udp_conns[i]);				xtcp_tx_buffer(mac_tx);			}		}	}}

void Network::on_idle(void *argument){    if (!ethernet->isUp()) return;    int len= sizeof(uip_buf); // set maximum size    if (ethernet->_receive_frame(uip_buf, &len)) {        uip_len = len;        this->handlePacket();    } else {        if (timer_expired(&periodic_timer)) { /* no packet but periodic_timer time out (0.1s)*/            timer_reset(&periodic_timer);            for (int i = 0; i < UIP_CONNS; i++) {                uip_periodic(i);                /* If the above function invocation resulted in data that                   should be sent out on the network, the global variable                   uip_len is set to a value > 0. */                if (uip_len > 0) {                    uip_arp_out();                    tapdev_send(uip_buf, uip_len);                }            }#if UIP_CONF_UDP            for (int i = 0; i < UIP_UDP_CONNS; i++) {                uip_udp_periodic(i);                /* If the above function invocation resulted in data that                   should be sent out on the network, the global variable                   uip_len is set to a value > 0. */                if (uip_len > 0) {                    uip_arp_out();                    tapdev_send(uip_buf, uip_len);                }            }#endif        }/*        This didn't work actually made it worse,it should have worked though        else{            // TODO if the command queue is below a certain amount we should poll any stopped connections            if(command_q->size() < 4) {                for (struct uip_conn *connr = &uip_conns[0]; connr <= &uip_conns[UIP_CONNS - 1]; ++connr) {                    if(uip_stopped(connr)){                        // Force a poll of this                        printf("Force poll of connection/n");                        uip_poll_conn(connr);                    }                }            }        }*/        /* Call the ARP timer function every 10 seconds. */        if (timer_expired(&arp_timer)) {            timer_reset(&arp_timer);            uip_arp_timer();        }    }}

void ethernet_service(void) {	int i;	struct uip_eth_hdr *buf = (struct uip_eth_hdr *)&uip_buf[0];	etimer_request_poll();	process_run();	uip_len = liteethmac_poll();	if(uip_len > 0) {		if(buf->type == uip_htons(UIP_ETHTYPE_IP)) {			uip_arp_ipin();			uip_input();			if(uip_len > 0) {				uip_arp_out();				liteethmac_send();			}		} else if(buf->type == uip_htons(UIP_ETHTYPE_ARP)) {			uip_arp_arpin();			if(uip_len > 0)				liteethmac_send();		}	} else if (elapsed(&uip_periodic_event, uip_periodic_period)) {		for(i = 0; i < UIP_CONNS; i++) {			uip_periodic(i);			if(uip_len > 0) {				uip_arp_out();				liteethmac_send();			}		}	}	if (elapsed(&uip_arp_event, uip_arp_period)) {		uip_arp_timer();	}}

void deal(){    int i;    if(uip_len > 0) {        if(BUF_IF->type == htons(UIP_ETHTYPE_IP)) {            uip_arp_ipin();            uip_input();            /* If the above function invocation resulted in data that               should be sent out on the network, the global variable               uip_len is set to a value > 0. */            if(uip_len > 0) {                uip_arp_out();                current_dev->eth_tx(current_dev, uip_buf, uip_len);            }        } else if(BUF_IF->type == htons(UIP_ETHTYPE_ARP)) {            uip_arp_arpin();            /* If the above function invocation resulted in data that               should be sent out on the network, the global variable               uip_len is set to a value > 0. */            if(uip_len > 0) {                current_dev->eth_tx(current_dev, uip_buf, uip_len);            }        }    } else if(timer_expired(&periodic_timer)) {        timer_reset(&periodic_timer);        for(i = 0; i < UIP_CONNS; i++) {            uip_periodic(i);            /* If the above function invocation resulted in data that               should be sent out on the network, the global variable               uip_len is set to a value > 0. */            if(uip_len > 0) {                uip_arp_out();                current_dev->eth_tx(current_dev, uip_buf, uip_len);	            }        }#if UIP_UDP        for(i = 0; i < UIP_UDP_CONNS; i++) {            uip_udp_periodic(i);            /* If the above function invocation resulted in data that               should be sent out on the network, the global variable               uip_len is set to a value > 0. */            if(uip_len > 0) {                uip_arp_out();                current_dev->eth_tx(current_dev, uip_buf, uip_len);	            }        }#endif /* UIP_UDP */        /* Call the ARP timer function every 10 seconds. */        if(timer_expired(&arp_timer)) {            timer_reset(&arp_timer);            uip_arp_timer();        }    }    //rt_exit_critical();    return 0;}

void NanodeUIP::poll(void) {  int i;  uip_len = enc28j60PacketReceive(UIP_BUFSIZE,uip_buf);  if(uip_len > 0) {    if(BUF->type == UIP_HTONS(UIP_ETHTYPE_IP)) {      uip_arp_ipin();      uip_input();      /* If the above function invocation resulted in data that	 should be sent out on the network, the global variable	 uip_len is set to a value > 0. */      if(uip_len > 0) {	uip_arp_out();	enc28j60PacketSend(uip_len,uip_buf);      }    } else if(BUF->type == UIP_HTONS(UIP_ETHTYPE_ARP)) {      uip_arp_arpin();      /* If the above function invocation resulted in data that	 should be sent out on the network, the global variable	 uip_len is set to a value > 0. */      if(uip_len > 0) {	enc28j60PacketSend(uip_len,uip_buf);      }    }  } else if(timer_expired(&periodic_timer)) {    timer_reset(&periodic_timer);    for(i = 0; i < UIP_CONNS; i++) {      uip_periodic(i);      /* If the above function invocation resulted in data that	 should be sent out on the network, the global variable	 uip_len is set to a value > 0. */      if(uip_len > 0) {	uip_arp_out();	enc28j60PacketSend(uip_len,uip_buf);      }    }#if UIP_UDP    for(i = 0; i < UIP_UDP_CONNS; i++) {      uip_udp_periodic(i);      /* If the above function invocation resulted in data that	 should be sent out on the network, the global variable	 uip_len is set to a value > 0. */      if(uip_len > 0) {	uip_arp_out();	enc28j60PacketSend(uip_len,uip_buf);      }    }#endif /* UIP_UDP */    /* Call the ARP timer function every 10 seconds. */    if(timer_expired(&arp_timer)) {      timer_reset(&arp_timer);      uip_arp_timer();    }  }}

/** * @brief   Process Network * @param   None * @retval  None */void Network_Process(void){	static uint8_t arp_counter = 0;	int i;	for (i = 0; i < UIP_CONNS; i++)	{		uip_periodic(i);		if (uip_len > 0)		{			uip_arp_out();			enc28j60_send_packet((uint8_t *)uip_buf, uip_len);		}	}	#if UIP_UDP		for (i = 0; i < UIP_UDP_CONNS; i++)		{			uip_udp_periodic(i);			if (uip_len > 0)			{				uip_arp_out();				network_send();			}		}	#endif /* UIP_UDP */	if (++arp_counter >= 50)	{		arp_counter = 0;		uip_arp_timer();	}	uip_len = enc28j60_recv_packet((uint8_t *)uip_buf, UIP_BUFSIZE);	if (uip_len > 0)	{		if (((struct uip_eth_hdr *)&uip_buf[0])->type == htons(UIP_ETHTYPE_IP))		{			uip_arp_ipin();			uip_input();			if (uip_len > 0)			{				uip_arp_out();				enc28j60_send_packet((uint8_t *)uip_buf, uip_len);			}		}		else if (((struct uip_eth_hdr *)&uip_buf[0])->type == htons(UIP_ETHTYPE_ARP))		{			uip_arp_arpin();			if (uip_len > 0)			{				enc28j60_send_packet((uint8_t *)uip_buf, uip_len);			}		}	}}

/** ******************************************************************************************* * @fn         void TcpIpMain(void) * @brief      Update the uIP stack. * @return     None * @attention ******************************************************************************************* */void TcpIpMain(void){   uint8_t                                 Index;   uip_len = nic_poll();   if (uip_len == 0)   {         // If timed out, call periodic function for each connection         if (TcpIpUipTimerCounter >= TCP_IP_CNT_TIME)         {            TcpIpUipTimerCounter = 0;            for (Index = 0; Index < UIP_CONNS; Index++)            {               uip_periodic(Index);               if (uip_len > 0)               {                  uip_arp_out();                  nic_send();               }            }            /* Call the ARP timer function every ~10 seconds. */            if (++TcpIpUipArpTimerCounter >= TCP_IP_ARP_CNT_TIME)            {               uip_arp_timer();               TcpIpUipArpTimerCounter = 0;            }         }   }   else                                                                        // packet received   {      // process an IP packet      if (TCP_IP_BUF->type == htons(UIP_ETHTYPE_IP))      {         uip_arp_ipin();         uip_input();         if (uip_len > 0)         {            uip_arp_out();            nic_send();         }      }      // process an ARP packet      else if (TCP_IP_BUF->type == htons(UIP_ETHTYPE_ARP))      {         uip_arp_arpin();         if (uip_len > 0)            nic_send();      }      TcpIpUipTimerCounter = 0;   }}

void uip_timeout_entry(void* parameter)//由于TIMEOUT函数，不参与调度{   // struct timer periodic_timer, arp_timer;    static uint8_t cnt;    int i;	/* post message to ethernet thread */    //if ((rt_sem_take(msg,RT_WAITING_NO)) != -RT_ETIMEOUT)     //if (timer_expired(&periodic_timer)) //5s enter once    {       //timer_reset(&periodic_timer);       for (i = 0; i < UIP_CONNS; i++)       {	  uip_periodic(i);	/* If the above function invocation resulted in data that	   should be sent out on the network, the global variable	   uip_len is set to a value > 0. */	  if (uip_len > 0)          {	      uip_arp_out();	      TransmitPacket();	  }       }#if UIP_UDP       for (i = 0; i < UIP_UDP_CONNS; i++) //       {	   uip_udp_periodic(i);	/* If the above function invocation resulted in data that	   should be sent out on the network, the global variable	   uip_len is set to a value > 0. */	   if (uip_len > 0)           {	      uip_arp_out();	      TransmitPacket();	    }        }#endif /* UIP_UDP */             /* Call the ARP timer function every 10 seconds. */       //if (timer_expired(&arp_timer))        if (++cnt >= 2) //t       {	  //timer_reset(&arp_timer);	  uip_arp_timer();          cnt = 0;       }    }  }

err_ttcpip_input(struct pbuf *p, struct netif *inp){    int i;    u8_t *pdata;    if (uip_len)    {        uip_arp_out();        if (( pdata =(u8_t*)malloc(1500*sizeof(u8_t))) == NULL)        {            pbuf_free(p);            return 1;        }        for (i=0; i < (UIP_LLH_LEN + 40); ++i) // 14+40 =54        {            pdata[i] =  uip_buf[i]; /* get dest an src ipaddr */        }        // Copy the data portion part        for(; i < uip_len; ++i)        {            pdata[i] =  uip_appdata[i - UIP_LLH_LEN - 40 ];        }        p ->payload = pdata;        p->len = uip_len;        inp->linkoutput(inp,p);        rt_free(pdata);        return 1;    }    else    {        pbuf_free(p);        return 0;    }}

static int vnet_uiptxpoll(struct uip_driver_s *dev){  FAR struct vnet_driver_s *vnet = (FAR struct vnet_driver_s *)dev->d_private;  /* If the polling resulted in data that should be sent out on the network,   * the field d_len is set to a value > 0.   */  if (vnet->sk_dev.d_len > 0)    {      uip_arp_out(&vnet->sk_dev);      vnet_transmit(vnet);      /* Check if there is room in the device to hold another packet. If not,       * return a non-zero value to terminate the poll.       */      if (vnet_is_txbuff_full(vnet->vnet))	  return 1;    }  /* If zero is returned, the polling will continue until all connections have   * been examined.   */  return 0;}

int netif_rx(u8_t *p, u16_t len){    /*avoid Rx packet length > UIP buffer size  and cause UIP buffer overflow*/    if (len <= UIP_BUFSIZE + 2) {        mt76xx_dev_read(p, len);    } else {        printf_high("netif_rx length error: %d > %d/n", len, UIP_BUFSIZE + 2);        return -1;    }    if (uip_len > 0) {        if (BUF->type == htons(UIP_ETHTYPE_IP)) {            uip_arp_ipin();            uip_input();            /* If the above function invocation resulted in data that            should be sent out on the network, the global variable            uip_len is set to a value > 0. */            if (uip_len > 0) {                uip_arp_out();                mt76xx_dev_send();            }        } else if (BUF->type == htons(UIP_ETHTYPE_ARP)) {            uip_arp_arpin();            /* If the above function invocation resulted in data that            should be sent out on the network, the global variable            uip_len is set to a value > 0. */            if (uip_len > 0) {                mt76xx_dev_send();            }        }    }    return 0;}

static int e1000_uiptxpoll(struct uip_driver_s *dev){    struct e1000_dev *e1000 = (struct e1000_dev *)dev->d_private;    int tail = e1000->tx_ring.tail;    /* If the polling resulted in data that should be sent out on the network,     * the field d_len is set to a value > 0.     */    if (e1000->uip_dev.d_len > 0) {		uip_arp_out(&e1000->uip_dev);		e1000_transmit(e1000);		/* Check if there is room in the device to hold another packet. If not,		 * return a non-zero value to terminate the poll.		 */		if (!e1000->tx_ring.desc[tail].desc_status)			return -1;    }    /* If zero is returned, the polling will continue until all connections have     * been examined.     */    return 0;}

uint8_ttapdev_output(void){   uip_arp_out();   tapdev_send();     return 0;}

void Network::handlePacket(void){    if (uip_len > 0) {  /* received packet */        //printf("handlePacket: %d/n", uip_len);        if (BUF->type == htons(UIP_ETHTYPE_IP)) { /* IP packet */            uip_arp_ipin();            uip_input();            /* If the above function invocation resulted in data that                should be sent out on the network, the global variable                uip_len is set to a value > 0. */            if (uip_len > 0) {                uip_arp_out();                network_device_send();            }        } else if (BUF->type == htons(UIP_ETHTYPE_ARP)) { /*ARP packet */            uip_arp_arpin();            /* If the above function invocation resulted in data that                should be sent out on the network, the global variable                uip_len is set to a value > 0. */            if (uip_len > 0) {                tapdev_send(uip_buf, uip_len);  /* ARP ack*/            }        } else {            printf("Unknown ethernet packet type %04X/n", htons(BUF->type));            uip_len = 0;        }    }}

/*---------------------------------------------------------------------------*/static voidoutput(u8_t *hdr, u16_t hdrlen, u8_t *data, u16_t datalen){  uip_arp_out();  lan91c96_send();  dump_packet();}

/*---------------------------------------------------------------------------*/uint8_tethernet_output(void){  uip_arp_out();  ethernet_send();    return 0;}

u8_twpcap_output(void){   uip_arp_out();   wpcap_send();     return 0;}

/*---------------------------------------------------------------------------*/static u8_toutput(void){  uip_arp_out();  cs8900a_send();    return 0;}

/*---------------------------------------------------------------------------*/u8_trtl8019_output(void){  uip_arp_out();  RTL8019dev_send();  return 0;}

static void maybe_send(void){  /* If the above function invocation resulted in data that     should be sent out on the network, the global variable     uip_len is set to a value > 0. */  if(uip_len > 0) {    uip_arp_out();    nic_send(NULL);  }}

void nethandler_periodic(){	int i;	times(UIP_CONNS, i) {		uip_periodic(i);		if (uip_len > 0) {			uip_arp_out();			network_send();		}	}

/*---------------------------------------------------------------------------*/static u8_toutput(void){    uip_arp_out();  lan91c96_send();  dump_packet();    return 0;}

void xtcp_process_udp_acks(chanend mac_tx){	for (int i = 0; i < UIP_UDP_CONNS; i++) {		if (uip_udp_conn_has_ack(&uip_udp_conns[i])) {			uip_udp_ackdata(i);			if (uip_len > 0) {				uip_arp_out(&uip_udp_conns[i]);				xtcp_tx_buffer(mac_tx);			}		}	}}

/* * TCP/IP periodic timer. */static void PeriodicTimerHandler(eventid_t id) {  int i;  (void)id;  for (i = 0; i < UIP_CONNS; i++) {    uip_periodic(i);    if (uip_len > 0) {      uip_arp_out();      network_device_send();    }  }}

/*-----------------------------------------------------------------------------------*/static voidtimer(void){  for(i = 0; i < UIP_CONNS; ++i) {    uip_periodic(i);    if(uip_len > 0) {      uip_arp_out();      rtl8019as_send();    }  }  for(i = 0; i < UIP_UDP_CONNS; i++) {    uip_udp_periodic(i);    /* If the above function invocation resulted in data that       should be sent out on the network, the global variable       uip_len is set to a value > 0. */    if(uip_len > 0) {      uip_arp_out();      rtl8019as_send();    }  }   }

void xtcpd_check_connection_poll(chanend mac_tx){	for (int i = 0; i < UIP_CONNS; i++) {		if (uip_conn_needs_poll(&uip_conns[i])) {			uip_poll_conn(&uip_conns[i]);			if (uip_len > 0) {				uip_arp_out( NULL);				xtcp_tx_buffer(mac_tx);			}		}	}	for (int i = 0; i < UIP_UDP_CONNS; i++) {		if (uip_udp_conn_needs_poll(&uip_udp_conns[i])) {			uip_udp_periodic(i);			if (uip_len > 0) {				uip_arp_out(&uip_udp_conns[i]);				xtcp_tx_buffer(mac_tx);			}		}	}}

void rtos_vnet_recv(struct rgmp_vnet *vnet_dummy, char *data, int len){    // now only support 1 vnet    struct vnet_driver_s *vnet = &g_vnet[0];    do {	/* Check for errors and update statistics */	/* Check if the packet is a valid size for the uIP buffer configuration */	if (len > CONFIG_NET_BUFSIZE || len < 14) {#ifdef CONFIG_DEBUG	    cprintf("VNET: receive invalid packet of size %d/n", len);#endif	    return;	}	// Copy the data data from the hardware to vnet->sk_dev.d_buf.  Set	// amount of data in vnet->sk_dev.d_len	memcpy(vnet->sk_dev.d_buf, data, len);	vnet->sk_dev.d_len = len;	/* We only accept IP packets of the configured type and ARP packets */#ifdef CONFIG_NET_IPv6	if (BUF->type == HTONS(UIP_ETHTYPE_IP6))#else	if (BUF->type == HTONS(UIP_ETHTYPE_IP))#endif	{	    uip_arp_ipin(&vnet->sk_dev);	    uip_input(&vnet->sk_dev);	    // If the above function invocation resulted in data that should be	    // sent out on the network, the field  d_len will set to a value > 0.	    if (vnet->sk_dev.d_len > 0) {		uip_arp_out(&vnet->sk_dev);		vnet_transmit(vnet);	    }	}	else if (BUF->type == htons(UIP_ETHTYPE_ARP)) {	    uip_arp_arpin(&vnet->sk_dev);	    // If the above function invocation resulted in data that should be	    // sent out on the network, the field  d_len will set to a value > 0.	    if (vnet->sk_dev.d_len > 0) {		vnet_transmit(vnet);	    }	}    }    while (0); /* While there are more packets to be processed */}