/*  Low level AX.25 code:
 *  incoming frame processing (including digipeating)
 *  IP encapsulation
 *  digipeater routing
 *
 *  Copyright 1991 Phil Karn, KA9Q / 1991 Kevin Hil, G1EMM
 */
/* Mods by PA0GRI */

#include <stdio.h>
#include "global.h"
#include "config.h"
#include "mbuf.h"
#include "iface.h"
#include "arp.h"
#include "slip.h"
#include "ax25.h"
#include "lapb.h"
#include "netrom.h"
#include "ip.h"
#include "devparam.h"
#include "trace.h"
#include "pktdrvr.h"
#include "netuser.h"
#include "commands.h"
#include <ctype.h>

static int axsend __ARGS((struct iface *iface,char *dest,char *source,
	int cmdrsp,int ctl,struct mbuf *data));
static int axip_stop __ARGS((struct iface *iface));
static int axip_raw __ARGS((struct iface *iface,struct mbuf *bp));

/* List of AX.25 multicast addresses in network format (shifted ascii).
 * Only the first entry is used for transmissions, but any incoming
 * packet with any one of these destination addresses is recognized
 * as a multicast
 */
char Ax25multi[][AXALEN] = {
	'Q'<<1, 'S'<<1, 'T'<<1, ' '<<1, ' '<<1, ' '<<1, '0'<<1, /* QST */
	'M'<<1, 'A'<<1, 'I'<<1, 'L'<<1, ' '<<1, ' '<<1, '0'<<1, /* MAIL */
	'N'<<1, 'O'<<1, 'D'<<1, 'E'<<1, 'S'<<1, ' '<<1, '0'<<1, /* NODES */
	'I'<<1, 'D'<<1, ' '<<1, ' '<<1, ' '<<1, ' '<<1, '0'<<1, /* ID */
	'O'<<1, 'P'<<1, 'E'<<1, 'N'<<1, ' '<<1, ' '<<1, '0'<<1, /* OPEN */
	'C'<<1, 'Q'<<1, ' '<<1, ' '<<1, ' '<<1, ' '<<1, '0'<<1, /* CQ */
	'B'<<1, 'E'<<1, 'A'<<1, 'C'<<1, 'O'<<1, 'N'<<1, '0'<<1, /* BEACON */
	'R'<<1, 'M'<<1, 'N'<<1, 'C'<<1, ' '<<1, ' '<<1, '0'<<1, /* RMNC */
	'A'<<1, 'L'<<1, 'L'<<1, ' '<<1, ' '<<1, ' '<<1, '0'<<1, /* ALL */
	'\0',
};
char Mycall[AXALEN];
struct ax_route *Ax_routes;	/* Routing table header */
int Digipeat = 1;	/* Controls digipeating */
#ifdef AXIP
static int32 axipaddr[NAX25];	/* table of IP addresses of AX.25 interfaces */
#ifdef PPP
extern int16 fcstab[];		/* table used when calculating FCS */
#else
int16 fcstab[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
};
#endif
#endif

/* Send IP datagrams across an AX.25 link */
int
ax_send(bp,iface,gateway,prec,del,tput,rel)
struct mbuf *bp;
struct iface *iface;
int32 gateway;
int prec;
int del;
int tput;
int rel;
{
	char *hw_addr;
	struct ax25_cb *axp;
	struct mbuf *tbp;

	struct ax_route *axr;
	char mode = AX_DEFMODE;		/* default to interface mode */

	if(gateway == iface->broadcast) /* This is a broadcast IP datagram */
	     return (*iface->output)(iface,Ax25multi[0],iface->hwaddr,PID_IP,bp);

	if((hw_addr = res_arp(iface,ARP_AX25,gateway,bp)) == NULLCHAR)
		return 0;	/* Wait for address resolution */

	/* If there's a defined route, get it */
	axr = ax_lookup(hw_addr);

	if(axr == NULLAXR) {
		if(iface->flags == DATAGRAM_MODE){
			mode = AX_DATMODE;
		} else {
			mode = AX_VC_MODE;
		}
	} else {
		mode = axr->mode;
		if(mode == AX_DEFMODE) {
			if(iface->flags == DATAGRAM_MODE){
				mode = AX_DATMODE;
			} else {
				mode = AX_VC_MODE;
			}
		}	
	}

	/* UI frames are used for any one of the following three conditions:
	 * 1. The "low delay" bit is set in the type-of-service field.
	 * 2. The "reliability" TOS bit is NOT set and the interface is in
	 *    datagram mode.
	 * 3. The destination is the broadcast address (this is helpful
	 *    when broadcasting on an interface that's in connected mode).
	 */
	if(del || (!rel && (mode == AX_DATMODE))
	 || addreq(hw_addr,Ax25multi[0])){
		/* Use UI frame */
		return (*iface->output)(iface,hw_addr,iface->hwaddr,PID_IP,bp);
	}


	/* Reliability is needed; use I-frames in AX.25 connection */
	if((axp = find_ax25(hw_addr)) == NULLAX25){
		/* Open a new connection */
		axp = open_ax25(iface,iface->hwaddr,hw_addr,
		 AX_ACTIVE,Axwindow,s_arcall,s_atcall,s_ascall,-1);
		if(axp == NULLAX25){
			free_p(bp);
			return -1;
		}
	}
	if(axp->state == LAPB_DISCONNECTED){
		est_link(axp);
		lapbstate(axp,LAPB_SETUP);
	}
	/* Insert the PID */
	if((tbp = pushdown(bp,1)) == NULLBUF){
		free_p(bp);
		return -1;
	}
	bp = tbp;
	bp->data[0] = PID_IP;
	if((tbp = segmenter(bp,axp->paclen)) == NULLBUF){
		free_p(bp);
		return -1;
	}
	return send_ax25(axp,tbp,-1);
}
/* Add header and send connectionless (UI) AX.25 packet.
 * Note that the calling order here must match enet_output
 * since ARP also uses it.
 */
int
ax_output(iface,dest,source,pid,data)
struct iface *iface;	/* Interface to use; overrides routing table */
char *dest;		/* Destination AX.25 address (7 bytes, shifted) */
char *source;		/* Source AX.25 address (7 bytes, shifted) */
int16 pid;		/* Protocol ID */
struct mbuf *data;	/* Data field (follows PID) */
{
	struct mbuf *bp;

	/* Prepend pid to data */
	bp = pushdown(data,1);
	if(bp == NULLBUF){
		free_p(data);
		return -1;
	}
	bp->data[0] = (char)pid;
	return axsend(iface,dest,source,LAPB_COMMAND,UI,bp);
}
/* Common subroutine for sendframe() and ax_output() */
static int
axsend(iface,dest,source,cmdrsp,ctl,data)
struct iface *iface;	/* Interface to use; overrides routing table */
char *dest;		/* Destination AX.25 address (7 bytes, shifted) */
char *source;		/* Source AX.25 address (7 bytes, shifted) */
int cmdrsp;		/* Command/response indication */
int ctl;		/* Control field */
struct mbuf *data;	/* Data field (includes PID) */
{
	struct mbuf *cbp;
	struct ax25 addr;
	struct ax_route *axr;
	char *idest;
	int rval;

	/* If the source addr is unspecified, use the interface address */
	if(source[0] == '\0')
		source = iface->hwaddr;

	/* If there's a digipeater route, get it */
	axr = ax_lookup(dest);

	memcpy(addr.dest,dest,AXALEN);
	memcpy(addr.source,source,AXALEN);
	addr.cmdrsp = cmdrsp;

	if(axr != NULLAXR){
		memcpy(addr.digis,axr->digis,axr->ndigis*AXALEN);
		addr.ndigis = axr->ndigis;
		idest = addr.digis[0];
	} else {
		addr.ndigis = 0;
		idest = dest;
	}

	addr.nextdigi = 0;

	/* Allocate mbuf for control field, and fill in */
	if((cbp = pushdown(data,1)) == NULLBUF){
		free_p(data);
		return -1;
	}
	cbp->data[0] = ctl;

	if((data = htonax25(&addr,cbp)) == NULLBUF){
		free_p(cbp);	/* Also frees data */
		return -1;
	}
	/* This shouldn't be necessary because redirection has already been
	 * done at the IP router layer, but just to be safe...
	 */
	if(iface->forw != NULLIF){
		logsrc(iface->forw,iface->forw->hwaddr);
		logdest(iface->forw,idest);
		rval = (*iface->forw->raw)(iface->forw,data);
	} else {
		logsrc(iface,iface->hwaddr);
		logdest(iface,idest);
		rval = (*iface->raw)(iface,data);
	}
	return rval;
}
#ifdef	AXIP
/* Handle AX.25 frames received inside IP according to RFC-1226 */
void
axip_input(iface,ip,bp,rxbroadcast)
struct iface *iface;    /* Input interface */
struct ip *ip;          /* IP header */
struct mbuf *bp;        /* AX.25 frame with FCS */
int rxbroadcast;	/* Accepted for now */
{
	int i;
	struct mbuf *tbp;
	int16 len, f, fcs = 0xffff;

	/* Since the AX.25 frame arrived on an interface that does
	   not necessarily support AX.25, we have to find a suitable
	   AX.25 interface, or drop the packet.
	 */
	/* Try to find a matching AX.25 pseudo interface */
	for(i=0; i < NAX25; ++i)
	     if(axipaddr[i] == ip->source)
		  break;
	if(i == NAX25) {
	     /* Here we could still try to pick a real AX.25 interface,
		but that would mean that we are accepting AX.25 frames
		from unknown IP hosts, so we'd rather drop it.
	      */
	     free_p(bp);
	     return;
	}
	iface = Ifaces;
	while (iface != NULLIF) {
	     if(iface->raw == axip_raw && iface->dev == i)
		  /* found the right AX.25 pseudo interface */
		  break;
	     iface = iface->next;
	}
	if(iface == NULLIF) {
	     free_p(bp);
	     return;
	}
	len = len_p(bp) - sizeof(fcs);
	if(dup_p(&tbp,bp,0,len) != len) {
	     free_p(bp);
	     return;
	}
	while(len--)
	     fcs = (fcs >> 8) ^ fcstab[(fcs ^ PULLCHAR(&bp)) & 0x00ff];
	fcs ^= 0xffff;
	f = PULLCHAR(&bp);
	f |= (PULLCHAR(&bp) << 8);
	if(fcs == f){
	     ax_recv(iface,tbp);
	} else
	     free_p(tbp);
}
#endif
/* Process incoming AX.25 packets.
 * After optional tracing, the address field is examined. If it is
 * directed to us as a digipeater, repeat it.  If it is addressed to
 * us or to QST-0, kick it upstairs depending on the protocol ID.
 */
void
ax_recv(iface,bp)
struct iface *iface;
struct mbuf *bp;
{
	struct mbuf *hbp;
	char control;
	struct ax25 hdr;
	struct ax25_cb *axp;
	struct ax_route *axr;
	struct iface *cross;
	char (*mpp)[AXALEN];
	int mcast;
	char *isrc,*idest;	/* "immediate" source and destination */

	/* Pull header off packet and convert to host structure */
	if(ntohax25(&hdr,&bp) < 0){
		/* Something wrong with the header */
		free_p(bp);
		return;
	}
	/* If there were digis in this packet and at least one has
	 * been passed, then the last passed digi is the immediate source.
	 * Otherwise it is the original source.
	 */
	if(hdr.ndigis != 0 && hdr.nextdigi != 0)
		isrc = hdr.digis[hdr.nextdigi-1];
	else
		isrc = hdr.source;

	/* If there are digis in this packet and not all have been passed,
	 * then the immediate destination is the next digi. Otherwise it
	 * is the final destination.
	 */
	cross = NULLIF;
	if(hdr.ndigis != 0 && hdr.nextdigi != hdr.ndigis){
		idest = hdr.digis[hdr.nextdigi];
		if(!addreq(idest,iface->hwaddr)){
			/* Check if digi matches callsign of any other
			 * interface for crossband digipeating.
			 */
			for(cross = Ifaces; cross != NULLIF; cross = cross->next){
				if(cross->type == CL_AX25 &&
					addreq(idest,cross->hwaddr)) {
					/* Swap callsigns so that the reply
					 * can be crossband digipeated in
					 * the other direction.
					 */
					memcpy(idest,iface->hwaddr,AXALEN);
					break;
				}
			}
		}
	}
	else
		idest = hdr.dest;

	/* Don't log our own packets if we overhear them, as they're
	 * already logged by axsend() and by the digipeater code.
	 */
	if(!addreq(isrc,iface->hwaddr)){
		logsrc(iface,isrc);
		logdest(iface,idest);
	}
	/* Examine immediate destination for a multicast address */
	mcast = 0;
	for(mpp = Ax25multi;(*mpp)[0] != '\0';mpp++){
		if(addreq(idest,*mpp)){
			mcast = 1;
			break;
		}
	}
	if(!mcast && !cross && !addreq(idest,iface->hwaddr)){
		/* Not a broadcast, and not addressed to us. Inhibit
		 * transmitter to avoid colliding with addressed station's
		 * response, and discard packet.
		 */
		if(iface->ioctl != NULL){
			(*iface->ioctl)(iface,PARAM_MUTE,1,-1L);
		}
		free_p(bp);
		return;
	}
	if(!mcast && !cross && iface->ioctl != NULL){
		/* Packet was sent to us; abort transmit inhibit */
		(*iface->ioctl)(iface,PARAM_MUTE,1,0L);
	}
	/* At this point, packet is either addressed to us, or is
	 * a multicast.
	 */
	if(hdr.nextdigi < hdr.ndigis){
		/* Packet requests digipeating. See if we can repeat it. */
		if(Digipeat && !mcast){
			/* Yes, kick it back out. htonax25 will set the
			 * repeated bit.
			 */
			hdr.nextdigi++;
			if((hbp = htonax25(&hdr,bp)) != NULLBUF){
				logsrc(iface,iface->hwaddr);
				if(cross)	/* Crossband digipeat */
					iface = cross;
				if(iface->forw != NULLIF){
					logdest(iface->forw,hdr.digis[hdr.nextdigi]);
					(*iface->forw->raw)(iface->forw,hbp);
				} else {
					logdest(iface,hdr.digis[hdr.nextdigi]);
					(*iface->raw)(iface,hbp);
				}
				bp = NULLBUF;
			}
		}
		free_p(bp);	/* Dispose if not forwarded */
		return;
	}
	/* If we reach this point, then the packet has passed all digis,
	 * and is either addressed to us or is a multicast
	 */
	if(bp == NULLBUF){
		return;		 /* Nothing left */
	}

	/* If there's no locally-set entry in the routing table and
	 * this packet has digipeaters, create or update it. Leave
	 * local routes alone.
	 */
	if(((axr = ax_lookup(hdr.source)) == NULLAXR || axr->type == AX_AUTO)
	 && hdr.ndigis > 0){
		char digis[MAXDIGIS][AXALEN];
		int i,j;

		/* Construct reverse digipeater path */
		for(i=hdr.ndigis-1,j=0;i >= 0;i--,j++){
			memcpy(digis[j],hdr.digis[i],AXALEN);
			digis[j][ALEN] &= ~(E|REPEATED);
		}
		ax_add(hdr.source,AX_AUTO,digis,hdr.ndigis);
	}
	/* Sneak a peek at the control field. This kludge is necessary because
	 * AX.25 lacks a proper protocol ID field between the address and LAPB
	 * sublayers; a control value of UI indicates that LAPB is to be
	 * bypassed.
	 */
	control = *bp->data & ~PF;

	if(uchar(control) == UI){
		int pid;
		struct axlink *ipp;

		(void) PULLCHAR(&bp);
		if((pid = PULLCHAR(&bp)) == -1)
			return;		/* No PID */
		/* Find network level protocol and hand it off */
		for(ipp = Axlink;ipp->funct != NULL;ipp++){
			if(ipp->pid == pid)
				break;
		}
		if(ipp->funct != NULL)
			(*ipp->funct)(iface,NULLAX25,hdr.source,hdr.dest,bp,mcast);
		else
			free_p(bp);
		return;
	}
	/* Everything from here down is connected-mode LAPB, so ignore
	 * multicasts
	 */
	if(mcast){
		free_p(bp);
		return;
	}
	/* Find the source address in hash table */
	if((axp = find_ax25(hdr.source)) == NULLAX25){
		/* Create a new ax25 entry for this guy,
		 * insert into hash table keyed on his address,
		 * and initialize table entries
		 */
		if((axp = cr_ax25(hdr.source)) == NULLAX25){
			free_p(bp);
			return;
		}
		/* Swap source and destination */
		memcpy(axp->remote,hdr.source,AXALEN);
		memcpy(axp->local,hdr.dest,AXALEN);
		axp->iface = iface;
	}
	if(hdr.cmdrsp == LAPB_UNKNOWN)
		axp->proto = V1;	/* Old protocol in use */

	lapb_input(axp,hdr.cmdrsp,bp);
}
/* General purpose AX.25 frame output */
int
sendframe(axp,cmdrsp,ctl,data)
struct ax25_cb *axp;
int cmdrsp;
int ctl;
struct mbuf *data;
{
	return axsend(axp->iface,axp->remote,axp->local,cmdrsp,ctl,data);
}
/* Find a route for an AX.25 address */
struct ax_route *
ax_lookup(target)
char *target;
{
	register struct ax_route *axr;
	struct ax_route *axlast = NULLAXR;

	for(axr = Ax_routes; axr != NULLAXR; axlast = axr,axr = axr->next){
		if(memcmp(axr->target,target,AXALEN) == 0){
			if(axr != Ax_routes){
				/* Move entry to top of list to speed
				 * future searches
				 */
				axlast->next = axr->next;
				axr->next = Ax_routes;
				Ax_routes = axr;

			}
			return axr;
		}
	}
	return axr;
}
/* Add an entry to the AX.25 routing table */
struct ax_route *
ax_add(target,type,digis,ndigis)
char *target;
int type;
char digis[][AXALEN];
int ndigis;
{
	register struct ax_route *axr;

	if(ndigis < 0 || ndigis > MAXDIGIS)
		return NULLAXR;

	if((axr = ax_lookup(target)) == NULLAXR){
		axr = (struct ax_route *)callocw(1,sizeof(struct ax_route));
		axr->next = Ax_routes;
		Ax_routes = axr;
		memcpy(axr->target,target,AXALEN);
		axr->ndigis = ndigis;
	}
	axr->type = type;
	axr->mode = AX_DEFMODE;		/* set mode to default */
	if(axr->ndigis != ndigis)
		axr->ndigis = ndigis;

	memcpy(axr->digis,digis[0],ndigis*AXALEN);
	return axr;
}
int
ax_drop(target)
char *target;
{
	register struct ax_route *axr;
	struct ax_route *axlast = NULLAXR;

	for(axr = Ax_routes;axr != NULLAXR;axlast=axr,axr = axr->next)
		if(memcmp(axr->target,target,AXALEN) == 0)	
			break;
	if(axr == NULLAXR)
		return -1;	/* Not in table! */
	if(axlast != NULLAXR)
		axlast->next = axr->next;
	else
		Ax_routes = axr->next;

	free((char *)axr);
	return 0;
}
/* Handle ordinary incoming data (no network protocol) */
void
axnl3(iface,axp,src,dest,bp,mcast)
struct iface *iface;
struct ax25_cb *axp;
char *src;
char *dest;
struct mbuf *bp;
int mcast;
{
	if(axp == NULLAX25){
		beac_input(iface,src,bp);
	} else {
		append(&axp->rxq,bp);
		if(axp->r_upcall != NULLVFP)
			(*axp->r_upcall)(axp,len_p(axp->rxq));
	}
}

#ifdef	AXIP
/* attach a fake AX.25 interface for AX.25 on top of IP */
/* argv[0] == "axip"
 * argv[1] == name of new interface
 * argv[2] == MTU
 * argv[3] == hostname of remote end of wormhole
 * argv[4] == optional AX.25 callsign for this interface, must be specified
 *	      and be different from any other interface callsign if crossband
 *   	      digipeating is going to work properly
 */
int
axip_attach(argc,argv,p)
int argc;
char *argv[];
void *p;
{
     int i;
     struct iface *ifp;

     if(if_lookup(argv[1]) != NULLIF) {
	  tprintf("interface %s already attached\n",argv[1]);
	  return -1;
     }
     for(i=0; i < NAX25; ++i)
	  if(axipaddr[i] == 0)
	       break;
     if(i == NAX25) {
	  tprintf("too many AX25 interfaces attached\n");
	  return -1;
     }
     if((axipaddr[i] = resolve(argv[3])) == 0) {
	  tprintf("invalid address\n");
	  return -1;
     }
     if(!Digipeat)
	  tprintf("Warning: AX.25 Digipeating is still disabeled!\n");
     ifp = (struct iface *)callocw(1,sizeof(struct iface));
     ifp->dev = i;
     ifp->addr = Ip_addr;
     ifp->name = strdup(argv[1]);
     ifp->hwaddr = mallocw(AXALEN);
     memcpy(ifp->hwaddr,Mycall,AXALEN);
     ifp->mtu = atoi(argv[2]);
     setencap(ifp,"AX25");
     if(argc > 4) {
	  ifp->hwaddr = mallocw(ifp->iftype->hwalen);
	  (*ifp->iftype->scan)(ifp->hwaddr,argv[4]);
     }
     ifp->raw = axip_raw;
     ifp->stop = axip_stop;
     ifp->next = Ifaces;
     Ifaces = ifp;
     return 0;
}
static int
axip_stop(iface)
struct iface *iface;
{
     axipaddr[iface->dev] = 0;
     return 0;
}

/* raw routine for sending AX.25 on top of IP */
static int
axip_raw(iface,bp)
struct iface *iface;    /* Pointer to interface control block */
struct mbuf *bp;        /* Data field */
{
     int16 len, fcs = 0xffff;
     struct mbuf *bp1;

     dump(iface,IF_TRACE_OUT,iface->type,bp);
     iface->rawsndcnt++;
     iface->lastsent = secclock();
     len = len_p(bp);
     if(dup_p(&bp1,bp,0,len) != len) {
	  free_p(bp);
	  return -1;
     }
     while (len--)		/* calculate FCS */
	  fcs = (fcs >> 8) ^ fcstab[(fcs ^ PULLCHAR(&bp1)) & 0x00ff];

     fcs ^= 0xffff;	/* final FCS (is this right?) */
     if((bp1 = alloc_mbuf(sizeof (fcs))) == NULLBUF) {
	  free_p(bp);
	  return -1;
     }
     *bp1->data = fcs & 0xff;
     *(bp1->data+1) = (fcs >> 8) & 0xff;
     bp1->cnt += sizeof(fcs);
     append(&bp,bp1);
     return ip_send(INADDR_ANY,axipaddr[iface->dev],AX25_PTCL,0,0,bp,0,0,0);
}
#endif