esis.c

早期freebsd实现

		}
		IFDEBUG(D_ESISINPUT)
			printf("esis_eshinput: esh: ht %d, naddr %d nsellength %d\n",
					ht, naddr, nsellength);
		ENDDEBUG
		while (naddr-- > 0) {
			struct iso_addr *nsap2; u_char *buf2;
			ESIS_EXTRACT_ADDR(nsap, buf);
			/* see if there is at least one more nsap in ESH differing
			   only by nsel */
			if (nsellength != 0) for (buf2 = buf; buf2 < buflim;) {
				ESIS_EXTRACT_ADDR(nsap2, buf2);
				IFDEBUG(D_ESISINPUT)
					printf("esis_eshinput: comparing %s ", 
						clnp_iso_addrp(nsap));
					printf("and %s\n", clnp_iso_addrp(nsap2));
				ENDDEBUG
				if (Bcmp(nsap->isoa_genaddr, nsap2->isoa_genaddr,
						 nsap->isoa_len - nsellength) == 0) {
					nlen = nsellength;
					break;
				}
			}
			new_entry |= snpac_add(shp->snh_ifp,
									nsap, shp->snh_shost, SNPA_ES, ht, nlen);
			nlen = 0;
		}
	}
	IFDEBUG(D_ESISINPUT)
		printf("esis_eshinput: nsap %s is %s\n", 
			clnp_iso_addrp(nsap), new_entry ? "new" : "old");
	ENDDEBUG
	if (new_entry && (iso_systype & SNPA_IS))
		esis_shoutput(shp->snh_ifp, ESIS_ISH, esis_holding_time,
						shp->snh_shost, 6, (struct iso_addr *)0);
bad:
	return;
}

/*
 * FUNCTION:		esis_ishinput
 *
 * PURPOSE:			process an incoming ISH pdu
 *
 * RETURNS:			
 *
 * SIDE EFFECTS:	
 *
 * NOTES:			
 */
esis_ishinput(m, shp)
struct mbuf		*m;	/* esh pdu */
struct snpa_hdr	*shp;	/* subnetwork header */
{
	struct esis_fixed	*pdu = mtod(m, struct esis_fixed *);
	u_short				ht, newct;			/* holding time */
	struct iso_addr		*nsap; 				/* Network Entity Title */
	register u_char		*buf = (u_char *) (pdu + 1);
	register u_char		*buflim = pdu->esis_hdr_len + (u_char *)pdu;
	int					new_entry;

	esis_stat.es_ishrcvd++;
	CTOH(pdu->esis_ht_msb, pdu->esis_ht_lsb, ht);

	IFDEBUG(D_ESISINPUT)
		printf("esis_ishinput: ish: ht %d\n", ht);
	ENDDEBUG
	if (ESHonly)
		goto bad;

	ESIS_EXTRACT_ADDR(nsap, buf);

	while (buf < buflim) {
		switch (*buf) {
		case ESISOVAL_ESCT:
			if (iso_systype & SNPA_IS)
				break;
			if (buf[1] != 2)
				goto bad;
			CTOH(buf[2], buf[3], newct);
			if (esis_config_time != newct) {
				untimeout(esis_config,0);
				esis_config_time = newct;
				esis_config();
			}
			break;
		
		default:
			printf("Unknown ISH option: %x\n", *buf);
		}
		ESIS_NEXT_OPTION(buf);
	}
	new_entry = snpac_add(shp->snh_ifp, nsap, shp->snh_shost, SNPA_IS, ht, 0);
	IFDEBUG(D_ESISINPUT)
		printf("esis_ishinput: nsap %s is %s\n", 
			clnp_iso_addrp(nsap), new_entry ? "new" : "old");
	ENDDEBUG

	if (new_entry)
		esis_shoutput(shp->snh_ifp, 
			iso_systype & SNPA_ES ? ESIS_ESH : ESIS_ISH,
			esis_holding_time, shp->snh_shost, 6, (struct iso_addr *)0);
bad:
	return;
}

/*
 * FUNCTION:		esis_rdinput
 *
 * PURPOSE:			Process an incoming RD pdu
 *
 * RETURNS:			
 *
 * SIDE EFFECTS:	
 *
 * NOTES:			
 */
esis_rdinput(m0, shp)
struct mbuf		*m0;	/* esh pdu */
struct snpa_hdr	*shp;	/* subnetwork header */
{
	struct esis_fixed	*pdu = mtod(m0, struct esis_fixed *);
	u_short				ht;		/* holding time */
	struct iso_addr		*da, *net = 0, *netmask = 0, *snpamask = 0;
	register struct iso_addr *bsnpa;
	register u_char		*buf = (u_char *)(pdu + 1);
	register u_char		*buflim = pdu->esis_hdr_len + (u_char *)pdu;

	esis_stat.es_rdrcvd++;

	/* intermediate systems ignore redirects */
	if (iso_systype & SNPA_IS)
		return;
	if (ESHonly)
		return;

	CTOH(pdu->esis_ht_msb, pdu->esis_ht_lsb, ht);
	if (buf >= buflim)
		return;

	/* Extract DA */
	ESIS_EXTRACT_ADDR(da, buf);

	/* Extract better snpa */
	ESIS_EXTRACT_ADDR(bsnpa, buf);

	/* Extract NET if present */
	if (buf < buflim) {
		if (*buf == 0)
			buf++; /* no NET present, skip NETL anyway */
		else
			ESIS_EXTRACT_ADDR(net, buf);
	}

	/* process options */
	while (buf < buflim) {
		switch (*buf) {
		case ESISOVAL_SNPAMASK:
			if (snpamask) /* duplicate */
				return;
			snpamask = (struct iso_addr *)(buf + 1);
			break;

		case ESISOVAL_NETMASK:
			if (netmask) /* duplicate */
				return;
			netmask = (struct iso_addr *)(buf + 1);
			break;

		default:
			printf("Unknown option in ESIS RD (0x%x)\n", buf[-1]);
		}
		ESIS_NEXT_OPTION(buf);
	}

	IFDEBUG(D_ESISINPUT)
		printf("esis_rdinput: rd: ht %d, da %s\n", ht, clnp_iso_addrp(da));
		if (net)
			printf("\t: net %s\n", clnp_iso_addrp(net));
	ENDDEBUG
	/*
	 *	If netl is zero, then redirect is to an ES. We need to add an entry
	 *	to the snpa cache for (destination, better snpa).
	 *	If netl is not zero, then the redirect is to an IS. In this
	 *	case, add an snpa cache entry for (net, better snpa).
	 *
	 *	If the redirect is to an IS, add a route entry towards that
	 *	IS.
	 */
	if (net == 0 || net->isoa_len == 0 || snpamask) {
		/* redirect to an ES */
		snpac_add(shp->snh_ifp, da,
				bsnpa->isoa_genaddr, SNPA_ES, ht, 0);
	} else {
		snpac_add(shp->snh_ifp, net,
				bsnpa->isoa_genaddr, SNPA_IS, ht, 0);
		snpac_addrt(shp->snh_ifp, da, net, netmask);
	}
bad: ;    /* Needed by ESIS_NEXT_OPTION */
}

/*
 * FUNCTION:		esis_config
 *
 * PURPOSE:			Report configuration
 *
 * RETURNS:			
 *
 * SIDE EFFECTS:	
 *
 * NOTES:			Called every esis_config_time seconds
 */
void
esis_config()
{
	register struct ifnet	*ifp;

	timeout(esis_config, (caddr_t)0, hz * esis_config_time);

	/* 
	 *	Report configuration for each interface that 
	 *	- is UP
	 *	- has BROADCAST capability
	 *	- has an ISO address
	 */
	/* Todo: a better way would be to construct the esh or ish
	 * once and copy it out for all devices, possibly calling
	 * a method in the iso_ifaddr structure to encapsulate and
	 * transmit it.  This could work to advantage for non-broadcast media
	 */
	
	for (ifp = ifnet; ifp; ifp = ifp->if_next) {
		if ((ifp->if_flags & IFF_UP) &&
		    (ifp->if_flags & IFF_BROADCAST)) {
			/* search for an ISO address family */
			struct ifaddr	*ia;

			for (ia = ifp->if_addrlist; ia; ia = ia->ifa_next) {
				if (ia->ifa_addr->sa_family == AF_ISO) {
					esis_shoutput(ifp, 
						iso_systype & SNPA_ES ? ESIS_ESH : ESIS_ISH,
						esis_holding_time,
						(caddr_t)(iso_systype & SNPA_ES ? all_is_snpa : 
						all_es_snpa), 6, (struct iso_addr *)0);
					break;
				}
			}
		}
	}
}

/*
 * FUNCTION:		esis_shoutput
 *
 * PURPOSE:			Transmit an esh or ish pdu
 *
 * RETURNS:			nothing
 *
 * SIDE EFFECTS:	
 *
 * NOTES:			
 */
esis_shoutput(ifp, type, ht, sn_addr, sn_len, isoa)
struct ifnet	*ifp;
int				type;
short			ht;
caddr_t 		sn_addr;
int				sn_len;
struct	iso_addr *isoa;
{
	struct mbuf			*m, *m0;
	caddr_t				cp, naddrp;
	int					naddr = 0;
	struct esis_fixed	*pdu;
	struct iso_ifaddr	*ia;
	int					len;
	struct sockaddr_iso	siso;

	if (type == ESIS_ESH)
		esis_stat.es_eshsent++;
	else if (type == ESIS_ISH) 
		esis_stat.es_ishsent++;
	else {
		printf("esis_shoutput: bad pdu type\n");
		return;
	}

	IFDEBUG(D_ESISOUTPUT)
		int	i;
		printf("esis_shoutput: ifp x%x (%s%d), %s, ht %d, to: [%d] ",
			ifp, ifp->if_name, ifp->if_unit, type == ESIS_ESH ? "esh" : "ish",
			ht, sn_len);
		for (i=0; i<sn_len; i++)
			printf("%x%c", *(sn_addr+i), i < (sn_len-1) ? ':' : ' ');
		printf("\n");
	ENDDEBUG

	if ((m0 = m = m_gethdr(M_DONTWAIT, MT_HEADER)) == NULL) {
		esis_stat.es_nomem++;
		return;
	}
	bzero(mtod(m, caddr_t), MHLEN);

	pdu = mtod(m, struct esis_fixed *);
	naddrp = cp = (caddr_t)(pdu + 1);
	len = sizeof(struct esis_fixed);

	/*
	 *	Build fixed part of header
	 */
	pdu->esis_proto_id = ISO9542_ESIS;
	pdu->esis_vers = ESIS_VERSION;
	pdu->esis_type = type;
	HTOC(pdu->esis_ht_msb, pdu->esis_ht_lsb, ht);

	if (type == ESIS_ESH) {
		cp++;
		len++;
	}

	m->m_len = len;
	if (isoa) {
		/*
		 * Here we are responding to a clnp packet sent to an NSAP
		 * that is ours which was sent to the MAC addr all_es's.
		 * It is possible that we did not specifically advertise this
		 * NSAP, even though it is ours, so we will respond
		 * directly to the sender that we are here.  If we do have
		 * multiple NSEL's we'll tack them on so he can compress them out.
		 */
		(void) esis_insert_addr(&cp, &len, isoa, m, 0);
		naddr = 1;
	}
	for (ia = iso_ifaddr; ia; ia = ia->ia_next) {
		int nsellen = (type == ESIS_ISH ? ia->ia_addr.siso_tlen : 0); 
		int n = ia->ia_addr.siso_nlen;
		register struct iso_ifaddr *ia2;

		if (type == ESIS_ISH && naddr > 0)
			break;
		for (ia2 = iso_ifaddr; ia2 != ia; ia2 = ia2->ia_next)
			if (Bcmp(ia->ia_addr.siso_data, ia2->ia_addr.siso_data, n) == 0)
					break;
		if (ia2 != ia)
			continue;	/* Means we have previously copied this nsap */
		if (isoa && Bcmp(ia->ia_addr.siso_data, isoa->isoa_genaddr, n) == 0) {
			isoa = 0;
			continue;	/* Ditto */
		}
		IFDEBUG(D_ESISOUTPUT)
			printf("esis_shoutput: adding NSAP %s\n", 
				clnp_iso_addrp(&ia->ia_addr.siso_addr));
		ENDDEBUG
		if (!esis_insert_addr(&cp, &len,
							  &ia->ia_addr.siso_addr, m, nsellen)) {
			EXTEND_PACKET(m, m0, cp);
			(void) esis_insert_addr(&cp, &len, &ia->ia_addr.siso_addr, m,
									nsellen);
		}
		naddr++;
	}

	if (type == ESIS_ESH)
		*naddrp = naddr;
	else {
		/* add suggested es config timer option to ISH */
		if (M_TRAILINGSPACE(m) < 4) {
			printf("esis_shoutput: extending packet\n");
			EXTEND_PACKET(m, m0, cp);
		}
		*cp++ = ESISOVAL_ESCT;
		*cp++ = 2;
		HTOC(*cp, *(cp+1), esis_esconfig_time);
		len += 4;
		m->m_len += 4;
		IFDEBUG(D_ESISOUTPUT)
			printf("m0 0x%x, m 0x%x, data 0x%x, len %d, cp 0x%x\n",
			m0, m, m->m_data, m->m_len, cp);
		ENDDEBUG
	}

	m0->m_pkthdr.len = len;
	pdu->esis_hdr_len = len;
	iso_gen_csum(m0, ESIS_CKSUM_OFF, (int)pdu->esis_hdr_len);

	bzero((caddr_t)&siso, sizeof(siso));
	siso.siso_family = AF_ISO;
	siso.siso_data[0] = AFI_SNA;
	siso.siso_nlen = sn_len + 1;
	bcopy(sn_addr, siso.siso_data + 1, (unsigned)sn_len);
	(ifp->if_output)(ifp, m0, (struct sockaddr *)&siso, 0);
}

/*
 * FUNCTION:		isis_input
 *
 * PURPOSE:			Process an incoming isis packet
 *
 * RETURNS:			nothing
 *
 * SIDE EFFECTS:	
 *
 * NOTES:			
 */
isis_input(m0, shp)
struct mbuf		*m0;		/* ptr to first mbuf of pkt */
struct snpa_hdr	*shp;	/* subnetwork header */
{
	register int type;
	register struct rawcb *rp, *first_rp = 0;
	struct ifnet *ifp = shp->snh_ifp;
	char workbuf[16];
	struct mbuf *mm;

	IFDEBUG(D_ISISINPUT)
		int i;

		printf("isis_input: pkt on ifp x%x (%s%d): from:", ifp, 
			ifp->if_name, ifp->if_unit);
		for (i=0; i<6; i++)
			printf("%x%c", shp->snh_shost[i]&0xff, (i<5) ? ':' : ' ');
		printf(" to:");
		for (i=0; i<6; i++)
			printf("%x%c", shp->snh_dhost[i]&0xff, (i<5) ? ':' : ' ');
		printf("\n");
	ENDDEBUG
	esis_dl.sdl_alen = ifp->if_addrlen;
	esis_dl.sdl_index = ifp->if_index;
	bcopy(shp->snh_shost, (caddr_t)esis_dl.sdl_data, esis_dl.sdl_alen);
	for (rp = esis_pcb.rcb_next; rp != &esis_pcb; rp = rp->rcb_next) {
		if (first_rp == 0) {
			first_rp = rp;
			continue;
		}
		if (mm = m_copy(m0, 0, M_COPYALL)) { /*can't block at interrupt level */
			if (sbappendaddr(&rp->rcb_socket->so_rcv,
							  &esis_dl, mm, (struct mbuf *)0) != 0) {
				sorwakeup(rp->rcb_socket);
			 } else {
				IFDEBUG(D_ISISINPUT)
					printf("Error in sbappenaddr, mm = 0x%x\n", mm);
				ENDDEBUG
				m_freem(mm);
			}
		}
	}
	if (first_rp && sbappendaddr(&first_rp->rcb_socket->so_rcv,
							  &esis_dl, m0, (struct mbuf *)0) != 0) {
		sorwakeup(first_rp->rcb_socket);
		return;
	}
	m_freem(m0);
}

isis_output(sdl, m)
register struct sockaddr_dl	*sdl;
struct mbuf *m;
{
	register struct ifnet *ifp;
	struct ifaddr *ifa, *ifa_ifwithnet();
	struct sockaddr_iso siso;
	int error = 0;
	unsigned sn_len;

	ifa = ifa_ifwithnet((struct sockaddr *)sdl);	/* get ifp from sdl */
	if (ifa == 0) {
		IFDEBUG(D_ISISOUTPUT)
			printf("isis_output: interface not found\n");
		ENDDEBUG
		error = EINVAL;
		goto release;
	}
	ifp = ifa->ifa_ifp;
	sn_len = sdl->sdl_alen;
	IFDEBUG(D_ISISOUTPUT)
		u_char *cp = (u_char *)LLADDR(sdl), *cplim = cp + sn_len;
		printf("isis_output: ifp 0x%x (%s%d), to: ",
			ifp, ifp->if_name, ifp->if_unit);
		while (cp < cplim) {
			printf("%x", *cp++);
			printf("%c", (cp < cplim) ? ':' : ' ');
		}
		printf("\n");
	ENDDEBUG
	bzero((caddr_t)&siso, sizeof(siso));
	siso.siso_family = AF_ISO; /* This convention may be useful for X.25 */
	siso.siso_data[0] = AFI_SNA;
	siso.siso_nlen = sn_len + 1;
	bcopy(LLADDR(sdl), siso.siso_data + 1, sn_len);
	error = (ifp->if_output)(ifp, m, (struct sockaddr *)&siso, 0);
	if (error) {
		IFDEBUG(D_ISISOUTPUT)
			printf("isis_output: error from ether_output is %d\n", error);
		ENDDEBUG
	}
	return (error);

release:
	if (m != NULL)
		m_freem(m);
	return(error);
}


/*
 * FUNCTION:		esis_ctlinput
 *
 * PURPOSE:			Handle the PRC_IFDOWN transition
 *
 * RETURNS:			nothing
 *
 * SIDE EFFECTS:	
 *
 * NOTES:			Calls snpac_flush for interface specified.
 *					The loop through iso_ifaddr is stupid because
 *					back in if_down, we knew the ifp...
 */
esis_ctlinput(req, siso)
int						req;		/* request: we handle only PRC_IFDOWN */
struct sockaddr_iso		*siso;		/* address of ifp */
{
	register struct iso_ifaddr *ia;	/* scan through interface addresses */

	if (req == PRC_IFDOWN)
		for (ia = iso_ifaddr; ia; ia = ia->ia_next) {
			if (iso_addrmatch(IA_SIS(ia), siso))
				snpac_flushifp(ia->ia_ifp);
		}
}

#endif	/* ISO */