src/dev/ethertap.cc - public/gem5 - Git at Google

 /*
  * Copyright (c) 2003-2005 The Regents of The University of Michigan
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met: redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer;
  * 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;
  * neither the name of the copyright holders 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
  * OWNER 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.
  *
  * Authors: Nathan Binkert
  */

 /* @file
  * Interface to connect a simulated ethernet device to the real world
  */

 #if defined(__OpenBSD__) || defined(__APPLE__)
 #include <sys/param.h>
 #endif
 #include <netinet/in.h>

 #include <unistd.h>

 #include <deque>
 #include <string>

 #include "base/misc.hh"
 #include "base/pollevent.hh"
 #include "base/socket.hh"
 #include "base/trace.hh"
 #include "dev/etherdump.hh"
 #include "dev/etherint.hh"
 #include "dev/etherpkt.hh"
 #include "dev/ethertap.hh"

 using namespace std;

 /**
  */
 class TapListener
 {
   protected:
     /**
      */
     class Event : public PollEvent
     {
       protected:
         TapListener *listener;

       public:
         Event(TapListener *l, int fd, int e)
             : PollEvent(fd, e), listener(l) {}

         virtual void process(int revent) { listener->accept(); }
     };

     friend class Event;
     Event *event;

   protected:
     ListenSocket listener;
     EtherTap *tap;
     int port;

   public:
     TapListener(EtherTap *t, int p)
         : event(NULL), tap(t), port(p) {}
     ~TapListener() { if (event) delete event; }

     void accept();
     void listen();
 };

 void
 TapListener::listen()
 {
     while (!listener.listen(port, true)) {
         DPRINTF(Ethernet, "TapListener(listen): Can't bind port %d\n", port);
         port++;
     }

     ccprintf(cerr, "Listening for tap connection on port %d\n", port);
     event = new Event(this, listener.getfd(), POLLIN|POLLERR);
     pollQueue.schedule(event);
 }

 void
 TapListener::accept()
 {
     if (!listener.islistening())
         panic("TapListener(accept): cannot accept if we're not listening!");

     int sfd = listener.accept(true);
     if (sfd != -1)
         tap->attach(sfd);
 }

 /**
  */
 class TapEvent : public PollEvent
 {
   protected:
     EtherTap *tap;

   public:
     TapEvent(EtherTap *_tap, int fd, int e)
         : PollEvent(fd, e), tap(_tap) {}
     virtual void process(int revent) { tap->process(revent); }
 };

 EtherTap::EtherTap(const Params *p)
     : EtherObject(p), event(NULL), socket(-1), buflen(p->bufsz), dump(p->dump),
       interface(NULL), txEvent(this)
 {
     buffer = new char[buflen];
     listener = new TapListener(this, p->port);
     listener->listen();
     interface = new EtherTapInt(name() + ".interface", this);
 }

 EtherTap::~EtherTap()
 {
     if (event)
         delete event;
     if (buffer)
         delete [] buffer;

     delete listener;
 }

 void
 EtherTap::attach(int fd)
 {
     if (socket != -1)
         close(fd);

     buffer_offset = 0;
     data_len = 0;
     socket = fd;
     DPRINTF(Ethernet, "EtherTap attached\n");
     event = new TapEvent(this, socket, POLLIN|POLLERR);
     pollQueue.schedule(event);
 }

 void
 EtherTap::detach()
 {
     DPRINTF(Ethernet, "EtherTap detached\n");
     delete event;
     event = 0;
     close(socket);
     socket = -1;
 }

 bool
 EtherTap::recvPacket(EthPacketPtr packet)
 {
     if (dump)
         dump->dump(packet);

     DPRINTF(Ethernet, "EtherTap output len=%d\n", packet->length);
     DDUMP(EthernetData, packet->data, packet->length);
     uint32_t len = htonl(packet->length);
     write(socket, &len, sizeof(len));
     write(socket, packet->data, packet->length);

     interface->recvDone();

     return true;
 }

 void
 EtherTap::sendDone()
 {}

 void
 EtherTap::process(int revent)
 {
     if (revent & POLLERR) {
         detach();
         return;
     }

     char *data = buffer + sizeof(uint32_t);
     if (!(revent & POLLIN))
         return;

     if (buffer_offset < data_len + sizeof(uint32_t)) {
         int len = read(socket, buffer + buffer_offset, buflen - buffer_offset);
         if (len == 0) {
             detach();
             return;
         }

         buffer_offset += len;

         if (data_len == 0)
             data_len = ntohl(*(uint32_t *)buffer);

         DPRINTF(Ethernet, "Received data from peer: len=%d buffer_offset=%d "
                 "data_len=%d\n", len, buffer_offset, data_len);
     }

     while (data_len != 0 && buffer_offset >= data_len + sizeof(uint32_t)) {
         EthPacketPtr packet;
         packet = new EthPacketData(data_len);
         packet->length = data_len;
         memcpy(packet->data, data, data_len);

         buffer_offset -= data_len + sizeof(uint32_t);
         assert(buffer_offset >= 0);
         if (buffer_offset > 0) {
             memmove(buffer, data + data_len, buffer_offset);
             data_len = ntohl(*(uint32_t *)buffer);
         } else
             data_len = 0;

         DPRINTF(Ethernet, "EtherTap input len=%d\n", packet->length);
         DDUMP(EthernetData, packet->data, packet->length);
         if (!interface->sendPacket(packet)) {
             DPRINTF(Ethernet, "bus busy...buffer for retransmission\n");
             packetBuffer.push(packet);
             if (!txEvent.scheduled())
                 txEvent.schedule(curTick + retryTime);
         } else if (dump) {
             dump->dump(packet);
         }
     }
 }

 void
 EtherTap::retransmit()
 {
     if (packetBuffer.empty())
         return;

     EthPacketPtr packet = packetBuffer.front();
     if (interface->sendPacket(packet)) {
         if (dump)
             dump->dump(packet);
         DPRINTF(Ethernet, "EtherTap retransmit\n");
         packetBuffer.front() = NULL;
         packetBuffer.pop();
     }

     if (!packetBuffer.empty() && !txEvent.scheduled())
         txEvent.schedule(curTick + retryTime);
 }

 EtherInt*
 EtherTap::getEthPort(const std::string &if_name, int idx)
 {
     if (if_name == "tap") {
         if (interface->getPeer())
             panic("Interface already connected to\n");
         return interface;
     }
     return NULL;
 }


 //=====================================================================

 void
 EtherTap::serialize(ostream &os)
 {
     SERIALIZE_SCALAR(socket);
     SERIALIZE_SCALAR(buflen);
     uint8_t *buffer = (uint8_t *)this->buffer;
     SERIALIZE_ARRAY(buffer, buflen);
     SERIALIZE_SCALAR(buffer_offset);
     SERIALIZE_SCALAR(data_len);

     bool tapevent_present = false;
     if (event) {
         tapevent_present = true;
         SERIALIZE_SCALAR(tapevent_present);
         event->serialize(os);
     }
     else {
         SERIALIZE_SCALAR(tapevent_present);
     }
 }

 void
 EtherTap::unserialize(Checkpoint *cp, const std::string &section)
 {
     UNSERIALIZE_SCALAR(socket);
     UNSERIALIZE_SCALAR(buflen);
     uint8_t *buffer = (uint8_t *)this->buffer;
     UNSERIALIZE_ARRAY(buffer, buflen);
     UNSERIALIZE_SCALAR(buffer_offset);
     UNSERIALIZE_SCALAR(data_len);

     bool tapevent_present;
     UNSERIALIZE_SCALAR(tapevent_present);
     if (tapevent_present) {
         event = new TapEvent(this, socket, POLLIN|POLLERR);

         event->unserialize(cp,section);

         if (event->queued()) {
             pollQueue.schedule(event);
         }
     }
 }

 //=====================================================================

 EtherTap *
 EtherTapParams::create()
 {
     return new EtherTap(this);
 }
	/*
	* Copyright (c) 2003-2005 The Regents of The University of Michigan
	* All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions are
	* met: redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer;
	* 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;
	* neither the name of the copyright holders 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
	* OWNER 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.
	*
	* Authors: Nathan Binkert
	*/

	/* @file
	* Interface to connect a simulated ethernet device to the real world
	*/

	#if defined(__OpenBSD__) \|\| defined(__APPLE__)
	#include <sys/param.h>
	#endif
	#include <netinet/in.h>

	#include <unistd.h>

	#include <deque>
	#include <string>

	#include "base/misc.hh"
	#include "base/pollevent.hh"
	#include "base/socket.hh"
	#include "base/trace.hh"
	#include "dev/etherdump.hh"
	#include "dev/etherint.hh"
	#include "dev/etherpkt.hh"
	#include "dev/ethertap.hh"

	using namespace std;

	/**
	*/
	class TapListener
	{
	protected:
	/**
	*/
	class Event : public PollEvent
	{
	protected:
	TapListener *listener;

	public:
	Event(TapListener *l, int fd, int e)
	: PollEvent(fd, e), listener(l) {}

	virtual void process(int revent) { listener->accept(); }
	};

	friend class Event;
	Event *event;

	protected:
	ListenSocket listener;
	EtherTap *tap;
	int port;

	public:
	TapListener(EtherTap *t, int p)
	: event(NULL), tap(t), port(p) {}
	~TapListener() { if (event) delete event; }

	void accept();
	void listen();
	};

	void
	TapListener::listen()
	{
	while (!listener.listen(port, true)) {
	DPRINTF(Ethernet, "TapListener(listen): Can't bind port %d\n", port);
	port++;
	}

	ccprintf(cerr, "Listening for tap connection on port %d\n", port);
	event = new Event(this, listener.getfd(), POLLIN\|POLLERR);
	pollQueue.schedule(event);
	}

	void
	TapListener::accept()
	{
	if (!listener.islistening())
	panic("TapListener(accept): cannot accept if we're not listening!");

	int sfd = listener.accept(true);
	if (sfd != -1)
	tap->attach(sfd);
	}

	/**
	*/
	class TapEvent : public PollEvent
	{
	protected:
	EtherTap *tap;

	public:
	TapEvent(EtherTap *_tap, int fd, int e)
	: PollEvent(fd, e), tap(_tap) {}
	virtual void process(int revent) { tap->process(revent); }
	};

	EtherTap::EtherTap(const Params *p)
	: EtherObject(p), event(NULL), socket(-1), buflen(p->bufsz), dump(p->dump),
	interface(NULL), txEvent(this)
	{
	buffer = new char[buflen];
	listener = new TapListener(this, p->port);
	listener->listen();
	interface = new EtherTapInt(name() + ".interface", this);
	}

	EtherTap::~EtherTap()
	{
	if (event)
	delete event;
	if (buffer)
	delete [] buffer;

	delete listener;
	}

	void
	EtherTap::attach(int fd)
	{
	if (socket != -1)
	close(fd);

	buffer_offset = 0;
	data_len = 0;
	socket = fd;
	DPRINTF(Ethernet, "EtherTap attached\n");
	event = new TapEvent(this, socket, POLLIN\|POLLERR);
	pollQueue.schedule(event);
	}

	void
	EtherTap::detach()
	{
	DPRINTF(Ethernet, "EtherTap detached\n");
	delete event;
	event = 0;
	close(socket);
	socket = -1;
	}

	bool
	EtherTap::recvPacket(EthPacketPtr packet)
	{
	if (dump)
	dump->dump(packet);

	DPRINTF(Ethernet, "EtherTap output len=%d\n", packet->length);
	DDUMP(EthernetData, packet->data, packet->length);
	uint32_t len = htonl(packet->length);
	write(socket, &len, sizeof(len));
	write(socket, packet->data, packet->length);

	interface->recvDone();

	return true;
	}

	void
	EtherTap::sendDone()
	{}

	void
	EtherTap::process(int revent)
	{
	if (revent & POLLERR) {
	detach();
	return;
	}

	char *data = buffer + sizeof(uint32_t);
	if (!(revent & POLLIN))
	return;

	if (buffer_offset < data_len + sizeof(uint32_t)) {
	int len = read(socket, buffer + buffer_offset, buflen - buffer_offset);
	if (len == 0) {
	detach();
	return;
	}

	buffer_offset += len;

	if (data_len == 0)
	data_len = ntohl((uint32_t )buffer);

	DPRINTF(Ethernet, "Received data from peer: len=%d buffer_offset=%d "
	"data_len=%d\n", len, buffer_offset, data_len);
	}

	while (data_len != 0 && buffer_offset >= data_len + sizeof(uint32_t)) {
	EthPacketPtr packet;
	packet = new EthPacketData(data_len);
	packet->length = data_len;
	memcpy(packet->data, data, data_len);

	buffer_offset -= data_len + sizeof(uint32_t);
	assert(buffer_offset >= 0);
	if (buffer_offset > 0) {
	memmove(buffer, data + data_len, buffer_offset);
	data_len = ntohl((uint32_t )buffer);
	} else
	data_len = 0;

	DPRINTF(Ethernet, "EtherTap input len=%d\n", packet->length);
	DDUMP(EthernetData, packet->data, packet->length);
	if (!interface->sendPacket(packet)) {
	DPRINTF(Ethernet, "bus busy...buffer for retransmission\n");
	packetBuffer.push(packet);
	if (!txEvent.scheduled())
	txEvent.schedule(curTick + retryTime);
	} else if (dump) {
	dump->dump(packet);
	}
	}
	}

	void
	EtherTap::retransmit()
	{
	if (packetBuffer.empty())
	return;

	EthPacketPtr packet = packetBuffer.front();
	if (interface->sendPacket(packet)) {
	if (dump)
	dump->dump(packet);
	DPRINTF(Ethernet, "EtherTap retransmit\n");
	packetBuffer.front() = NULL;
	packetBuffer.pop();
	}

	if (!packetBuffer.empty() && !txEvent.scheduled())
	txEvent.schedule(curTick + retryTime);
	}

	EtherInt*
	EtherTap::getEthPort(const std::string &if_name, int idx)
	{
	if (if_name == "tap") {
	if (interface->getPeer())
	panic("Interface already connected to\n");
	return interface;
	}
	return NULL;
	}


	//=====================================================================

	void
	EtherTap::serialize(ostream &os)
	{
	SERIALIZE_SCALAR(socket);
	SERIALIZE_SCALAR(buflen);
	uint8_t buffer = (uint8_t )this->buffer;
	SERIALIZE_ARRAY(buffer, buflen);
	SERIALIZE_SCALAR(buffer_offset);
	SERIALIZE_SCALAR(data_len);

	bool tapevent_present = false;
	if (event) {
	tapevent_present = true;
	SERIALIZE_SCALAR(tapevent_present);
	event->serialize(os);
	}
	else {
	SERIALIZE_SCALAR(tapevent_present);
	}
	}

	void
	EtherTap::unserialize(Checkpoint *cp, const std::string &section)
	{
	UNSERIALIZE_SCALAR(socket);
	UNSERIALIZE_SCALAR(buflen);
	uint8_t buffer = (uint8_t )this->buffer;
	UNSERIALIZE_ARRAY(buffer, buflen);
	UNSERIALIZE_SCALAR(buffer_offset);
	UNSERIALIZE_SCALAR(data_len);

	bool tapevent_present;
	UNSERIALIZE_SCALAR(tapevent_present);
	if (tapevent_present) {
	event = new TapEvent(this, socket, POLLIN\|POLLERR);

	event->unserialize(cp,section);

	if (event->queued()) {
	pollQueue.schedule(event);
	}
	}
	}

	//=====================================================================

	EtherTap *
	EtherTapParams::create()
	{
	return new EtherTap(this);
	}