esis.c

早期freebsd实现

/*-
 * Copyright (c) 1991, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University 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 REGENTS 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 REGENTS 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.
 *
 *	@(#)esis.c	8.1 (Berkeley) 6/10/93
 */

/***********************************************************
		Copyright IBM Corporation 1987

                      All Rights Reserved

Permission to use, copy, modify, and distribute this software and its 
documentation for any purpose and without fee is hereby granted, 
provided that the above copyright notice appear in all copies and that
both that copyright notice and this permission notice appear in 
supporting documentation, and that the name of IBM not be
used in advertising or publicity pertaining to distribution of the
software without specific, written prior permission.  

IBM DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING
ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL
IBM BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR
ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
SOFTWARE.

******************************************************************/

/*
 * ARGO Project, Computer Sciences Dept., University of Wisconsin - Madison
 */

#ifdef ISO

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/domain.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/errno.h>
#include <sys/kernel.h>

#include <net/if.h>
#include <net/if_dl.h>
#include <net/route.h>
#include <net/raw_cb.h>

#include <netiso/iso.h>
#include <netiso/iso_pcb.h>
#include <netiso/iso_var.h>
#include <netiso/iso_snpac.h>
#include <netiso/clnl.h>
#include <netiso/clnp.h>
#include <netiso/clnp_stat.h>
#include <netiso/esis.h>
#include <netiso/argo_debug.h>

/*
 *	Global variables to esis implementation
 *
 *	esis_holding_time - the holding time (sec) parameter for outgoing pdus
 *	esis_config_time  - the frequency (sec) that hellos are generated
 *	esis_esconfig_time - suggested es configuration time placed in the
 *						ish.
 *
 */
struct rawcb	esis_pcb;
void				esis_config(), snpac_age();
int				esis_sendspace = 2048;
int				esis_recvspace = 2048;
short			esis_holding_time = ESIS_HT;
short			esis_config_time = ESIS_CONFIG;
short			esis_esconfig_time = ESIS_CONFIG;
extern int		iso_systype;
struct sockaddr_dl	esis_dl = { sizeof(esis_dl), AF_LINK };
extern char		all_es_snpa[], all_is_snpa[];

#define EXTEND_PACKET(m, mhdr, cp)\
	if (((m)->m_next = m_getclr(M_DONTWAIT, MT_HEADER)) == NULL) {\
		esis_stat.es_nomem++;\
		m_freem(mhdr);\
		return;\
	} else {\
		(m) = (m)->m_next;\
		(cp) = mtod((m), caddr_t);\
	}
/*
 * FUNCTION:		esis_init
 *
 * PURPOSE:			Initialize the kernel portion of esis protocol
 *
 * RETURNS:			nothing
 *
 * SIDE EFFECTS:	
 *
 * NOTES:			
 */
esis_init()
{
	extern struct clnl_protosw clnl_protox[256];
	int	esis_input(), isis_input();
#ifdef	ISO_X25ESIS
	int	x25esis_input();
#endif	/* ISO_X25ESIS */

	esis_pcb.rcb_next = esis_pcb.rcb_prev = &esis_pcb;
	llinfo_llc.lc_next = llinfo_llc.lc_prev = &llinfo_llc;

	timeout(snpac_age, (caddr_t)0, hz);
	timeout(esis_config, (caddr_t)0, hz);

	clnl_protox[ISO9542_ESIS].clnl_input = esis_input;
	clnl_protox[ISO10589_ISIS].clnl_input = isis_input;
#ifdef	ISO_X25ESIS
	clnl_protox[ISO9542X25_ESIS].clnl_input = x25esis_input;
#endif	/* ISO_X25ESIS */
}

/*
 * FUNCTION:		esis_usrreq
 *
 * PURPOSE:			Handle user level esis requests
 *
 * RETURNS:			0 or appropriate errno
 *
 * SIDE EFFECTS:	
 *
 */
/*ARGSUSED*/
esis_usrreq(so, req, m, nam, control)
struct socket	*so;		/* socket: used only to get to this code */
int				req;		/* request */
struct mbuf		*m;			/* data for request */
struct mbuf		*nam;		/* optional name */
struct mbuf		*control;	/* optional control */
{
	struct rawcb *rp = sotorawcb(so);
	int error = 0;

	if ((so->so_state & SS_PRIV) == 0) {
		error = EACCES;
		goto release;
	}
	if (rp == NULL && req != PRU_ATTACH) {
		error = EINVAL;
		goto release;
	}

	switch (req) {
	case PRU_ATTACH:
		if (rp != NULL) {
			error = EINVAL;
			break;
		}
		MALLOC(rp, struct rawcb *, sizeof(*rp), M_PCB, M_WAITOK);
		if (so->so_pcb = (caddr_t)rp) {
			bzero(so->so_pcb, sizeof(*rp));
			insque(rp, &esis_pcb);
			rp->rcb_socket = so;
			error = soreserve(so, esis_sendspace, esis_recvspace);
		} else
			error = ENOBUFS;
		break;

	case PRU_SEND:
		if (nam == NULL) {
			error = EINVAL;
			break;
		}
		/* error checking here */
		error = isis_output(mtod(nam,struct sockaddr_dl *), m);
		m = NULL;
		break;

	case PRU_DETACH:
		raw_detach(rp);
		break;

	case PRU_SHUTDOWN:
		socantsendmore(so);
		break;

	case PRU_ABORT:
		soisdisconnected(so);
		raw_detach(rp);
		break;

	case PRU_SENSE:
		return (0);

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

	return (error);
}

/*
 * FUNCTION:		esis_input
 *
 * PURPOSE:			Process an incoming esis packet
 *
 * RETURNS:			nothing
 *
 * SIDE EFFECTS:	
 *
 * NOTES:			
 */
esis_input(m0, shp)
struct mbuf		*m0;		/* ptr to first mbuf of pkt */
struct snpa_hdr	*shp;	/* subnetwork header */
{
	register struct esis_fixed	*pdu = mtod(m0, struct esis_fixed *);
	register int type;

	/*
	 *	check checksum if necessary
	 */
	if (ESIS_CKSUM_REQUIRED(pdu) && iso_check_csum(m0, (int)pdu->esis_hdr_len)) {
		esis_stat.es_badcsum++;
		goto bad;
	}

	/* check version */
	if (pdu->esis_vers != ESIS_VERSION) {
		esis_stat.es_badvers++;
		goto bad;
	}
	type = pdu->esis_type & 0x1f;
	switch (type) {
		case ESIS_ESH:
			esis_eshinput(m0, shp);
			break;

		case ESIS_ISH:
			esis_ishinput(m0, shp);
			break;

		case ESIS_RD:
			esis_rdinput(m0, shp);
			break;

		default:
			esis_stat.es_badtype++;
	}

bad:
	if (esis_pcb.rcb_next != &esis_pcb)
		isis_input(m0, shp);
	else
		m_freem(m0);
}

/*
 * FUNCTION:		esis_rdoutput
 *
 * PURPOSE:			Transmit a redirect pdu
 *
 * RETURNS:			nothing
 *
 * SIDE EFFECTS:	
 *
 * NOTES:			Assumes there is enough space for fixed part of header,
 *					DA, BSNPA and NET in first mbuf.
 */
esis_rdoutput(inbound_shp, inbound_m, inbound_oidx, rd_dstnsap, rt)
struct snpa_hdr		*inbound_shp;	/* snpa hdr from incoming packet */
struct mbuf			*inbound_m;		/* incoming pkt itself */
struct clnp_optidx	*inbound_oidx;	/* clnp options assoc with incoming pkt */
struct iso_addr		*rd_dstnsap;	/* ultimate destination of pkt */
struct rtentry		*rt;			/* snpa cache info regarding next hop of
										pkt */
{
	struct mbuf			*m, *m0;
	caddr_t				cp;
	struct esis_fixed	*pdu;
	int					len, total_len = 0;
	struct sockaddr_iso	siso;
	struct ifnet 		*ifp = inbound_shp->snh_ifp;
	struct sockaddr_dl *sdl;
	struct iso_addr *rd_gwnsap;

	if (rt->rt_flags & RTF_GATEWAY) {
		rd_gwnsap = &((struct sockaddr_iso *)rt->rt_gateway)->siso_addr;
		rt = rtalloc1(rt->rt_gateway, 0);
	} else
		rd_gwnsap = &((struct sockaddr_iso *)rt_key(rt))->siso_addr;
	if (rt == 0 || (sdl = (struct sockaddr_dl *)rt->rt_gateway) == 0 ||
		sdl->sdl_family != AF_LINK) {
		/* maybe we should have a function that you
		   could put in the iso_ifaddr structure
		   which could translate iso_addrs into snpa's
		   where there is a known mapping for that address type */
		esis_stat.es_badtype++;
		return;
	}
	esis_stat.es_rdsent++;
	IFDEBUG(D_ESISOUTPUT)
		printf("esis_rdoutput: ifp x%x (%s%d), ht %d, m x%x, oidx x%x\n",
			ifp, ifp->if_name, ifp->if_unit, esis_holding_time, inbound_m,
			inbound_oidx);
		printf("\tdestination: %s\n", clnp_iso_addrp(rd_dstnsap));
		printf("\tredirected toward:%s\n", clnp_iso_addrp(rd_gwnsap));
	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 *);
	cp = (caddr_t)(pdu + 1); /*pointer arith.; 1st byte after header */
	len = sizeof(struct esis_fixed);

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

	/* Insert destination address */
	(void) esis_insert_addr(&cp, &len, rd_dstnsap, m, 0);

	/* Insert the snpa of better next hop */
	*cp++ = sdl->sdl_alen;
	bcopy(LLADDR(sdl), cp, sdl->sdl_alen);
	cp += sdl->sdl_alen;
	len += (sdl->sdl_alen + 1);

	/* 
	 *	If the next hop is not the destination, then it ought to be
	 *	an IS and it should be inserted next. Else, set the
	 *	NETL to 0
	 */
	/* PHASE2 use mask from ifp of outgoing interface */
	if (!iso_addrmatch1(rd_dstnsap, rd_gwnsap)) {
		/* this should not happen: 
		if ((nhop_sc->sc_flags & SNPA_IS) == 0) {
			printf("esis_rdoutput: next hop is not dst and not an IS\n");
			m_freem(m0);
			return;
		} */
		(void) esis_insert_addr(&cp, &len, rd_gwnsap, m, 0);
	} else {
		*cp++ = 0;	/* NETL */
		len++;
	}
	m->m_len = len;

	/*
	 *	PHASE2
	 *	If redirect is to an IS, add an address mask. The mask to be
	 *	used should be the mask present in the routing entry used to
	 *	forward the original data packet.
	 */
	
	/*
	 *	Copy Qos, priority, or security options present in original npdu
	 */
	if (inbound_oidx) {
		/* THIS CODE IS CURRENTLY (mostly) UNTESTED */
		int optlen = 0;
		if (inbound_oidx->cni_qos_formatp)
			optlen += (inbound_oidx->cni_qos_len + 2);
		if (inbound_oidx->cni_priorp)	/* priority option is 1 byte long */
			optlen += 3;
		if (inbound_oidx->cni_securep)
			optlen += (inbound_oidx->cni_secure_len + 2);
		if (M_TRAILINGSPACE(m) < optlen) {
			EXTEND_PACKET(m, m0, cp);
			m->m_len = 0;
			/* assumes MLEN > optlen */
		}
		/* assume MLEN-len > optlen */
		/* 
		 *	When copying options, copy from ptr - 2 in order to grab
		 *	the option code and length
		 */
		if (inbound_oidx->cni_qos_formatp) {
			bcopy(mtod(inbound_m, caddr_t) + inbound_oidx->cni_qos_formatp - 2,
				cp, (unsigned)(inbound_oidx->cni_qos_len + 2));
			cp += inbound_oidx->cni_qos_len + 2;
		}
		if (inbound_oidx->cni_priorp) {
			bcopy(mtod(inbound_m, caddr_t) + inbound_oidx->cni_priorp - 2,
					cp, 3);
			cp += 3;
		}
		if (inbound_oidx->cni_securep) {
			bcopy(mtod(inbound_m, caddr_t) + inbound_oidx->cni_securep - 2, cp, 
				(unsigned)(inbound_oidx->cni_secure_len + 2));
			cp += inbound_oidx->cni_secure_len + 2;
		}
		m->m_len += optlen;
		len += optlen;
	}

	pdu->esis_hdr_len = m0->m_pkthdr.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 = 6 + 1;	/* should be taken from snpa_hdr */
										/* +1 is for AFI */
	bcopy(inbound_shp->snh_shost, siso.siso_data + 1, 6);
	(ifp->if_output)(ifp, m0, (struct sockaddr *)&siso, 0);
}

/*
 * FUNCTION:		esis_insert_addr
 *
 * PURPOSE:			Insert an iso_addr into a buffer
 *
 * RETURNS:			true if buffer was big enough, else false
 *
 * SIDE EFFECTS:	Increment buf & len according to size of iso_addr
 *
 * NOTES:			Plus 1 here is for length byte
 */
esis_insert_addr(buf, len, isoa, m, nsellen)
register caddr_t			*buf;		/* ptr to buffer to put address into */
int							*len;		/* ptr to length of buffer so far */
register struct iso_addr	*isoa;		/* ptr to address */
register struct mbuf		*m;			/* determine if there remains space */
int							nsellen;
{
	register int newlen, result = 0;

	isoa->isoa_len -= nsellen;
	newlen = isoa->isoa_len + 1;
	if (newlen <=  M_TRAILINGSPACE(m)) {
		bcopy((caddr_t)isoa, *buf, newlen);
		*len += newlen;
		*buf += newlen;
		m->m_len += newlen;
		result = 1;
	}
	isoa->isoa_len += nsellen;
	return (result);
}

#define ESIS_EXTRACT_ADDR(d, b) { d = (struct iso_addr *)(b); b += (1 + *b); \
	    if (b > buflim) {esis_stat.es_toosmall++; goto bad;}}
#define ESIS_NEXT_OPTION(b)	{ b += (2 + b[1]); \
	    if (b > buflim) {esis_stat.es_toosmall++; goto bad;}}
int ESHonly = 0;
/*
 
/*
 * FUNCTION:		esis_eshinput
 *
 * PURPOSE:			Process an incoming ESH pdu
 *
 * RETURNS:			nothing
 *
 * SIDE EFFECTS:	
 *
 * NOTES:			
 */
esis_eshinput(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;		/* holding time */
	struct	iso_addr	*nsap;
	int					naddr;
	u_char				*buf = (u_char *)(pdu + 1);
	u_char				*buflim = pdu->esis_hdr_len + (u_char *)pdu;
	int					new_entry = 0;

	esis_stat.es_eshrcvd++;

	CTOH(pdu->esis_ht_msb, pdu->esis_ht_lsb, ht);

	naddr = *buf++;
	if (buf >= buflim)
		goto bad;
	if (naddr == 1) {
		ESIS_EXTRACT_ADDR(nsap, buf);
		new_entry = snpac_add(shp->snh_ifp,
								 nsap, shp->snh_shost, SNPA_ES, ht, 0);
	} else {
		int nsellength = 0, nlen = 0;
		{
		/* See if we want to compress out multiple nsaps differing
		   only by nsel */
			register struct ifaddr *ifa = shp->snh_ifp->if_addrlist;
			for (; ifa; ifa = ifa->ifa_next)
				if (ifa->ifa_addr->sa_family == AF_ISO) {
					nsellength = ((struct iso_ifaddr *)ifa)->ia_addr.siso_tlen;
					break;
			}