/*
    Copyright 2000 (c) by David Schweikert,
    Swiss Federal Institute of Technology,
    Computer Engineering and Networks Laboratory.

    TOPSY -- A Teachable Operating System.
             Implementation of a tiny and simple
             micro kernel for teaching purposes.

    For further information, please visit http://www.tik.ee.ethz.ch/~topsy

    This software is provided under the terms of the GNU General Public 
    Licence. A full copy of the GNU GPL is provided in the file COPYING 
    found in the development root of Topsy.
*/
/*
	
    File:                  $Source: /usr/drwho/vault/cvs/topsy/Topsy/Net/Ethertap/NetEthertap.c,v $
    Author(s):             
    Affiliation:           ETH Zuerich, TIK
    Version:               $Revision: 1.1 $
    Creation Date:         
    Last Date of Change:   $Date: 2000/03/31 17:50:36 $      by: $Author: gfa $


    $Log: NetEthertap.c,v $
    Revision 1.1  2000/03/31 17:50:36  gfa
    Merged with /Net from several term projects


*/
#include <Topsy.h>
#include <Messages.h>
#include <Syscall.h>
#include <NetAttr.h>
#include <NetBuf.h>
#include <NetConfig.h>
#include <NetDebug.h>
#include <NetIface.h>
#include <NetIO.h>
#include <NetModules.h>
#include <Ethertap/NetEthertap.h>

static void nettapRead(ThreadId dev, unsigned long int length, NetIfDesc *iface);
static void nettapDown(ThreadId dev, NetBuf buf, NetAttrs attrs);

static void nettap_setaddr(NetAttrs config, char *addr)
{
	unsigned short tmp;

	netdbgPrintf(NETDEBUG_ETHERTAP, "nettap: hw-address: %02x:%02x:%02x:%02x:%02x:%02x\n",
		     addr[0],addr[1],addr[2],addr[3],addr[4],addr[5]);
	
	tmp = addr[1]; tmp<<=8; tmp+=addr[0];
	netattrSet(config, NETATTR_ETH_FROM_0, tmp);

	tmp = addr[3]; tmp<<=8; tmp+=addr[2];
	netattrSet(config, NETATTR_ETH_FROM_1, tmp);

	tmp = addr[5]; tmp<<=8; tmp+=addr[4];
	netattrSet(config, NETATTR_ETH_FROM_2, tmp);
}

void nettapMain(NetIfDesc *iface)
{
	ThreadId ethertapMainId, ethertapDeviceId, parentid;
	NetAttrs config = iface->config;
	NetModMsg msg;
	Message *mmsg;
	char addr[6];

	tmGetInfo(SELF, &ethertapMainId, &parentid);
	
	/* Open/initialize device */
	ioOpen(IO_ETHERTAP, &ethertapDeviceId);
	ioInit(ethertapDeviceId);

	/* Subscribe to Ethertap kernel device driver */
	ioSubscribe(ethertapDeviceId, ethertapMainId);

	/* Get HW address / set attr */
	ioGetAddr(ethertapDeviceId, addr, 6);
	nettap_setaddr(config, addr);
 
	/* Add to list of modules */
	netmodAdd(NETMODULE_ETHERTAP, ethertapMainId);
	
	netdbgDisplay(NETDEBUG_ETHERTAP, "Ethertap module started.\n");

	while (1) {
		if(!netmodMsgRecv(&msg)) return;
		
		switch (msg.id) {
		case IO_NOTIFY:
			netdbgPrintf(NETDEBUG_ETHERTAP, "nettap: NOTIFY!\n");
			mmsg = (Message *) &msg;
			nettapRead(msg.from, mmsg->msg.ioNotify.length, iface);
			break;
		case NETMOD_SENDDOWN:
			nettapDown(ethertapDeviceId, msg.buf, msg.attrs);
			break;
		default:
			netdbgPrintf(NETDEBUG_ETHERTAP, "nettap: Unknown syscall!\n");
			break;
		}
	}
}

static void nettapRead(ThreadId id, unsigned long int length, NetIfDesc *iface)
{
	NetBuf buf;
	NetAttrs attrs;
	
	if (!netbufAlloc(&buf, length+2)) {
		netdbgDisplay(NETDEBUG_GENERIC, "*** ERROR: Ethertap: netbufAlloc failed.\n");
		return;
	}
	buf->start+=2; // hack for TCP aligned structure access

	/* ioOpen isn't needed because threadId is already known... */
	ioRead(id, NETBUF_DATA(buf), &length);
	buf->end = buf->start + length;

	netdbgPrintf(NETDEBUG_ETHERTAP, "nettap: got %d bytes.\n", length);

	/* set attributes */
	if(!netattrNew(&attrs)) {
		netdbgDisplay(NETDEBUG_GENERIC, "*** ERROR: Ethertap: netattrNew failed.\n");
		netbufFree(buf);
		return;
	}
	netattrSet(attrs, NETATTR_IF_FROM, iface->nr);
	
	netcfgSendNextUp(NETMODULE_ETHERTAP, buf, attrs);
}

static void nettapDown(ThreadId dev, NetBuf buf, NetAttrs attrs)
{
	netdbgPrintf(NETDEBUG_ETHERTAP, "nettap: Sending down packet (len=%d)\n",
		     netbufLen(buf));
	netioWrite(dev, buf);
	
	netbufFree(buf);
	netbufFree((NetBuf)attrs);
}