[unix-history] / sys / netiso / clnp_er.c

/*-
 * Copyright (c) 1991 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.
 *
 *	from: @(#)clnp_er.c	7.7 (Berkeley) 5/6/91
 *	$Id: clnp_er.c,v 1.3 1993/11/25 01:35:40 wollman Exp $
 */

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

#include "param.h"
#include "systm.h"
#include "mbuf.h"
#include "domain.h"
#include "protosw.h"
#include "socket.h"
#include "socketvar.h"
#include "errno.h"

#include "../net/if.h"
#include "../net/route.h"

#include "iso.h"
#include "iso_var.h"
#include "iso_pcb.h"
#define CLNP_ER_CODES
#include "clnp.h"
#include "clnp_stat.h"
#include "argo_debug.h"

static struct clnp_fixed er_template = {
	ISO8473_CLNP,	/* network identifier */
	0,				/* length */
	ISO8473_V1,		/* version */
	CLNP_TTL,		/* ttl */
	CLNP_ER,		/* type */
	0,				/* segment length */
	0				/* checksum */
};

/*
 * FUNCTION:		clnp_er_input
 *
 * PURPOSE:			Process an ER pdu.
 *
 * RETURNS:			
 *
 * SIDE EFFECTS:	
 *
 * NOTES:			
 */
void
clnp_er_input(m, src, reason)
	struct mbuf		*m;		/* ptr to packet itself */
	struct iso_addr	*src;	/* ptr to src of er */
	u_char			reason;	/* reason code of er */
{
	int	cmd = -1;
	extern u_char clnp_protox[];

	IFDEBUG(D_CTLINPUT)
		printf("clnp_er_input: m x%x, src %s, reason x%x\n", m, 
			clnp_iso_addrp(src), reason);
	ENDDEBUG

	INCSTAT(cns_er_inhist[clnp_er_index(reason)]);
	switch (reason) {
		case GEN_NOREAS:
		case GEN_PROTOERR:
			break;
		case GEN_BADCSUM:		
			cmd = PRC_PARAMPROB;
			break;
		case GEN_CONGEST:		
			cmd = PRC_QUENCH;
			break;
		case GEN_HDRSYNTAX:		
			cmd = PRC_PARAMPROB;
			break;
		case GEN_SEGNEEDED:		
			cmd = PRC_MSGSIZE; 
			break;
		case GEN_INCOMPLETE:	
			cmd = PRC_PARAMPROB; 		
			break;
		case GEN_DUPOPT:		
			cmd = PRC_PARAMPROB;		
			break;
		case ADDR_DESTUNREACH:	
			cmd = PRC_UNREACH_HOST; 	
			break;
		case ADDR_DESTUNKNOWN:	
			cmd = PRC_UNREACH_PROTOCOL; 
			break;
		case SRCRT_UNSPECERR:
		case SRCRT_SYNTAX:
		case SRCRT_UNKNOWNADDR:
		case SRCRT_BADPATH:
			cmd = PRC_UNREACH_SRCFAIL;
			break;
		case TTL_EXPTRANSIT:	
			cmd = PRC_TIMXCEED_INTRANS;	
			break;
		case TTL_EXPREASS:		
			cmd = PRC_TIMXCEED_REASS;	
			break;
		case DISC_UNSUPPOPT:
		case DISC_UNSUPPVERS:
		case DISC_UNSUPPSECURE:
		case DISC_UNSUPPSRCRT:
		case DISC_UNSUPPRECRT:
			cmd = PRC_PARAMPROB; 
			break;
		case REASS_INTERFERE:	
			cmd = PRC_TIMXCEED_REASS;
			break;
	}

	/*
	 *	tpclnp_ctlinput1 is called directly so that we don't
	 *	have to build an iso_sockaddr out of src.
	 */
	if (cmd >= 0)
		tpclnp_ctlinput1(cmd, src);

	m_freem(m);
}

/*
 * FUNCTION:		clnp_discard
 *
 * PURPOSE:			Discard a clnp datagram
 *
 * RETURNS:			nothing
 *
 * SIDE EFFECTS:	Will emit an ER pdu if possible
 *
 * NOTES:			This code assumes that we have previously tried to pull
 *					up the header of the datagram into one mbuf.
 */
void
clnp_discard(m, reason)
	struct mbuf *m;		/* header of packet to discard */
	char reason;		/* reason for discard */
{
	IFDEBUG(D_DISCARD)
		printf("clnp_discard: m x%x, reason x%x\n", m, reason);
	ENDDEBUG

	if (m != NULL) {
		if (m->m_len >= sizeof(struct clnp_fixed)) {
			register struct clnp_fixed *clnp = mtod(m, struct clnp_fixed *);

			if (((clnp->cnf_type & CNF_TYPE) != CLNP_ER) &&
				(clnp->cnf_type & CNF_ERR_OK)) {
					clnp_emit_er(m, reason);
					return;
			}
		}
		m_freem(m);
	}
}

/*
 * FUNCTION:		clnp_emit_er
 *
 * PURPOSE:			Send an ER pdu.
 *					The src of the of the ER pdu is the host that is sending
 *					the ER (ie. us), *not* the original destination of the
 *					packet.
 *
 * RETURNS:			nothing
 *
 * SIDE EFFECTS:	
 *
 * NOTES:			Takes responsibility for freeing mbuf passed
 *					This function may be called with a packet that
 *					was created by us; in this case, do not send
 *					an ER.
 */
void
clnp_emit_er(m, reason)
	struct mbuf	*m;		/* header of packet to discard */
	char reason;		/* reason for discard */
{
	register struct clnp_fixed	*clnp = mtod(m, struct clnp_fixed *);
	register struct clnp_fixed	*er;
	struct route_iso			route;
	struct ifnet				*ifp;
	struct sockaddr				*first_hop;
	struct iso_addr				src, dst, *our_addr;
	caddr_t						hoff, hend;
	int							total_len;		/* total len of dg */
	struct mbuf 				*m0;			/* contains er pdu hdr */
	struct iso_ifaddr			*ia = 0;

	IFDEBUG(D_DISCARD)
		printf("clnp_emit_er: m x%x, hdr len %d\n", m, clnp->cnf_hdr_len);
	ENDDEBUG

	bzero((caddr_t)&route, sizeof(route));

	/*
	 *	If header length is incorrect, or entire header is not contained
	 *	in this mbuf, we punt
	 */
	if ((clnp->cnf_hdr_len < CLNP_HDR_MIN) ||
		(clnp->cnf_hdr_len > CLNP_HDR_MAX) ||
		(clnp->cnf_hdr_len > m->m_len))
		goto bad;
	
	/* extract src, dest address */
	hend = (caddr_t)clnp + clnp->cnf_hdr_len;
	hoff = (caddr_t)clnp + sizeof(struct clnp_fixed);
	CLNP_EXTRACT_ADDR(dst, hoff, hend);
	if (hoff == (caddr_t)0) {
		goto bad;
	}
	CLNP_EXTRACT_ADDR(src, hoff, hend);
	if (hoff == (caddr_t)0) {
		goto bad;
	}
	
	/*
	 *	Do not send ER if we generated the packet.
	 */
	if (clnp_ours(&src))
		goto bad;

	/* 
	 *	Trim mbuf to hold only the header.
	 *	This mbuf will be the 'data' of the er pdu
	 */
	if (m->m_next != NULL) {
		m_freem(m->m_next);
		m->m_next = NULL;
	}

	if (m->m_len > clnp->cnf_hdr_len)
		m_adj(m, (int)-(m->m_len - (int)clnp->cnf_hdr_len));

	/* route er pdu: note we send pkt to src of original packet  */
	if (clnp_route(&src, &route, /* flags */0, &first_hop, &ia) != 0)
		goto bad;

	/* compute our address based upon firsthop/ifp */
	if (ia)
			our_addr = &ia->ia_addr.siso_addr;
	else
			goto bad;
	ifp = ia->ia_ifp;

	IFDEBUG(D_DISCARD)
		printf("clnp_emit_er: to %s", clnp_iso_addrp(&src));
		printf(" from %s\n", clnp_iso_addrp(our_addr));
	ENDDEBUG

	IFDEBUG(D_DISCARD)
		printf("clnp_emit_er: packet routed to %s\n", 
			clnp_iso_addrp(&((struct sockaddr_iso *)first_hop)->siso_addr));
	ENDDEBUG

	/* allocate mbuf for er pdu header: punt on no space */
	MGET(m0, M_DONTWAIT, MT_HEADER);
	if (m0 == 0)
		goto bad;
	
	m0->m_next = m;
	er = mtod(m0, struct clnp_fixed *);
	*er = er_template;

	/* setup src/dst on er pdu */
	/* NOTE REVERSAL OF SRC/DST */
	hoff = (caddr_t)er + sizeof(struct clnp_fixed);
	CLNP_INSERT_ADDR(hoff, src);
	CLNP_INSERT_ADDR(hoff, *our_addr);

	/*
	 *	TODO: if complete src rt was specified, then reverse path, and
	 *	copy into er as option.
	 */

	/* add er option */
	*hoff++ = CLNPOVAL_ERREAS;	/* code */
	*hoff++ = 2;				/* length */
	*hoff++ = reason;			/* discard reason */
	*hoff++ = 0;				/* error localization = not specified */

	/* set length */
	er->cnf_hdr_len = m0->m_len = (u_char)(hoff - (caddr_t)er);
	total_len = m0->m_len + m->m_len;
	HTOC(er->cnf_seglen_msb, er->cnf_seglen_lsb, total_len);

	/* compute checksum (on header only) */
	iso_gen_csum(m0, CLNP_CKSUM_OFF, (int)er->cnf_hdr_len);

	/* trim packet if too large for interface */
	if (total_len > ifp->if_mtu)
		m_adj(m0, -(total_len - ifp->if_mtu));
	
	/* send packet */
	INCSTAT(cns_er_outhist[clnp_er_index(reason)]);
	(void) (*ifp->if_output)(ifp, m0, first_hop, route.ro_rt);
	goto done;

bad:
	m_freem(m);

done:
	/* free route if it is a temp */
	if (route.ro_rt != NULL)
		RTFREE(route.ro_rt);
}

int
clnp_er_index(p)
	u_char p;
{
	register u_char *cp = clnp_er_codes + CLNP_ERRORS;
	while (cp > clnp_er_codes) {
		cp--;
		if (*cp == p)
			return (cp - clnp_er_codes);
	}
	return (CLNP_ERRORS + 1);
}
Commit	Line	Data
15637ed4 RG	1	/*-
	2	* Copyright (c) 1991 The Regents of the University of California.
	3	* All rights reserved.
	4	*
	5	* Redistribution and use in source and binary forms, with or without
	6	* modification, are permitted provided that the following conditions
	7	* are met:
	8	* 1. Redistributions of source code must retain the above copyright
	9	* notice, this list of conditions and the following disclaimer.
	10	* 2. Redistributions in binary form must reproduce the above copyright
	11	* notice, this list of conditions and the following disclaimer in the
	12	* documentation and/or other materials provided with the distribution.
	13	* 3. All advertising materials mentioning features or use of this software
	14	* must display the following acknowledgement:
	15	* This product includes software developed by the University of
	16	* California, Berkeley and its contributors.
	17	* 4. Neither the name of the University nor the names of its contributors
	18	* may be used to endorse or promote products derived from this software
	19	* without specific prior written permission.
	20	*
	21	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	22	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	23	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	24	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	25	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	26	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	27	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	28	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	29	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	30	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	31	* SUCH DAMAGE.
	32	*
43371f85	33	* from: @(#)clnp_er.c 7.7 (Berkeley) 5/6/91
fde1aeb2	34	* $Id: clnp_er.c,v 1.3 1993/11/25 01:35:40 wollman Exp $
15637ed4 RG	35	*/
	36
	37	/***********************************************************
	38	Copyright IBM Corporation 1987
	39
	40	All Rights Reserved
	41
	42	Permission to use, copy, modify, and distribute this software and its
	43	documentation for any purpose and without fee is hereby granted,
	44	provided that the above copyright notice appear in all copies and that
	45	both that copyright notice and this permission notice appear in
	46	supporting documentation, and that the name of IBM not be
	47	used in advertising or publicity pertaining to distribution of the
	48	software without specific, written prior permission.
	49
	50	IBM DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING
	51	ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL
	52	IBM BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR
	53	ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
	54	WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
	55	ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
	56	SOFTWARE.
	57
	58	******************************************************************/
	59
	60	/*
	61	* ARGO Project, Computer Sciences Dept., University of Wisconsin - Madison
	62	*/
15637ed4 RG	63
15637ed4 RG	64	#include "param.h"
fde1aeb2	65	#include "systm.h"
15637ed4 RG	66	#include "mbuf.h"
	67	#include "domain.h"
	68	#include "protosw.h"
	69	#include "socket.h"
	70	#include "socketvar.h"
	71	#include "errno.h"
	72
	73	#include "../net/if.h"
	74	#include "../net/route.h"
	75
	76	#include "iso.h"
	77	#include "iso_var.h"
	78	#include "iso_pcb.h"
	79	#define CLNP_ER_CODES
	80	#include "clnp.h"
	81	#include "clnp_stat.h"
	82	#include "argo_debug.h"
	83
	84	static struct clnp_fixed er_template = {
	85	ISO8473_CLNP, /* network identifier */
	86	0, /* length */
	87	ISO8473_V1, /* version */
	88	CLNP_TTL, /* ttl */
	89	CLNP_ER, /* type */
	90	0, /* segment length */
	91	0 /* checksum */
	92	};
	93
	94	/*
	95	* FUNCTION: clnp_er_input
	96	*
	97	* PURPOSE: Process an ER pdu.
	98	*
	99	* RETURNS:
	100	*
	101	* SIDE EFFECTS:
	102	*
	103	* NOTES:
	104	*/
4c45483e	105	void
15637ed4	106	clnp_er_input(m, src, reason)
4c45483e GW	107	struct mbuf m; / ptr to packet itself */
	108	struct iso_addr src; / ptr to src of er */
	109	u_char reason; /* reason code of er */
15637ed4 RG	110	{
	111	int cmd = -1;
	112	extern u_char clnp_protox[];
	113
	114	IFDEBUG(D_CTLINPUT)
	115	printf("clnp_er_input: m x%x, src %s, reason x%x\n", m,
	116	clnp_iso_addrp(src), reason);
	117	ENDDEBUG
	118
	119	INCSTAT(cns_er_inhist[clnp_er_index(reason)]);
	120	switch (reason) {
	121	case GEN_NOREAS:
	122	case GEN_PROTOERR:
	123	break;
	124	case GEN_BADCSUM:
	125	cmd = PRC_PARAMPROB;
	126	break;
	127	case GEN_CONGEST:
	128	cmd = PRC_QUENCH;
	129	break;
	130	case GEN_HDRSYNTAX:
	131	cmd = PRC_PARAMPROB;
	132	break;
	133	case GEN_SEGNEEDED:
	134	cmd = PRC_MSGSIZE;
	135	break;
	136	case GEN_INCOMPLETE:
	137	cmd = PRC_PARAMPROB;
	138	break;
	139	case GEN_DUPOPT:
	140	cmd = PRC_PARAMPROB;
	141	break;
	142	case ADDR_DESTUNREACH:
	143	cmd = PRC_UNREACH_HOST;
	144	break;
	145	case ADDR_DESTUNKNOWN:
	146	cmd = PRC_UNREACH_PROTOCOL;
	147	break;
	148	case SRCRT_UNSPECERR:
	149	case SRCRT_SYNTAX:
	150	case SRCRT_UNKNOWNADDR:
	151	case SRCRT_BADPATH:
	152	cmd = PRC_UNREACH_SRCFAIL;
	153	break;
	154	case TTL_EXPTRANSIT:
	155	cmd = PRC_TIMXCEED_INTRANS;
	156	break;
	157	case TTL_EXPREASS:
	158	cmd = PRC_TIMXCEED_REASS;
	159	break;
	160	case DISC_UNSUPPOPT:
	161	case DISC_UNSUPPVERS:
	162	case DISC_UNSUPPSECURE:
	163	case DISC_UNSUPPSRCRT:
	164	case DISC_UNSUPPRECRT:
	165	cmd = PRC_PARAMPROB;
	166	break;
	167	case REASS_INTERFERE:
	168	cmd = PRC_TIMXCEED_REASS;
	169	break;
	170	}
	171
	172	/*
	173	* tpclnp_ctlinput1 is called directly so that we don't
174	* have to build an iso_sockaddr out of src.
175	*/
176	if (cmd >= 0)
177	tpclnp_ctlinput1(cmd, src);
178
179	m_freem(m);
180	}
181
182	/*
183	* FUNCTION: clnp_discard
184	*
185	* PURPOSE: Discard a clnp datagram
186	*
187	* RETURNS: nothing
188	*
189	* SIDE EFFECTS: Will emit an ER pdu if possible
190	*
191	* NOTES: This code assumes that we have previously tried to pull
192	* up the header of the datagram into one mbuf.
193	*/
4c45483e	194	void
15637ed4	195	clnp_discard(m, reason)
4c45483e GW	196	struct mbuf m; / header of packet to discard */
4c45483e GW	197	char reason; /* reason for discard */
15637ed4 RG	198	{
	199	IFDEBUG(D_DISCARD)
	200	printf("clnp_discard: m x%x, reason x%x\n", m, reason);
	201	ENDDEBUG
	202
	203	if (m != NULL) {
	204	if (m->m_len >= sizeof(struct clnp_fixed)) {
	205	register struct clnp_fixed clnp = mtod(m, struct clnp_fixed );
	206
	207	if (((clnp->cnf_type & CNF_TYPE) != CLNP_ER) &&
	208	(clnp->cnf_type & CNF_ERR_OK)) {
	209	clnp_emit_er(m, reason);
	210	return;
	211	}
	212	}
	213	m_freem(m);
	214	}
	215	}
	216
	217	/*
	218	* FUNCTION: clnp_emit_er
	219	*
	220	* PURPOSE: Send an ER pdu.
	221	* The src of the of the ER pdu is the host that is sending
	222	* the ER (ie. us), not the original destination of the
	223	* packet.
	224	*
	225	* RETURNS: nothing
	226	*
	227	* SIDE EFFECTS:
	228	*
	229	* NOTES: Takes responsibility for freeing mbuf passed
	230	* This function may be called with a packet that
	231	* was created by us; in this case, do not send
	232	* an ER.
	233	*/
4c45483e	234	void
15637ed4	235	clnp_emit_er(m, reason)
4c45483e GW	236	struct mbuf m; / header of packet to discard */
4c45483e GW	237	char reason; /* reason for discard */
15637ed4 RG	238	{
	239	register struct clnp_fixed clnp = mtod(m, struct clnp_fixed );
	240	register struct clnp_fixed *er;
	241	struct route_iso route;
	242	struct ifnet *ifp;
	243	struct sockaddr *first_hop;
	244	struct iso_addr src, dst, *our_addr;
	245	caddr_t hoff, hend;
	246	int total_len; /* total len of dg */
	247	struct mbuf m0; / contains er pdu hdr */
	248	struct iso_ifaddr *ia = 0;
	249
	250	IFDEBUG(D_DISCARD)
	251	printf("clnp_emit_er: m x%x, hdr len %d\n", m, clnp->cnf_hdr_len);
	252	ENDDEBUG
	253
	254	bzero((caddr_t)&route, sizeof(route));
	255
	256	/*
	257	* If header length is incorrect, or entire header is not contained
	258	* in this mbuf, we punt
	259	*/
	260	if ((clnp->cnf_hdr_len < CLNP_HDR_MIN) \|\|
	261	(clnp->cnf_hdr_len > CLNP_HDR_MAX) \|\|
	262	(clnp->cnf_hdr_len > m->m_len))
	263	goto bad;
	264
	265	/* extract src, dest address */
	266	hend = (caddr_t)clnp + clnp->cnf_hdr_len;
	267	hoff = (caddr_t)clnp + sizeof(struct clnp_fixed);
	268	CLNP_EXTRACT_ADDR(dst, hoff, hend);
	269	if (hoff == (caddr_t)0) {
	270	goto bad;
	271	}
	272	CLNP_EXTRACT_ADDR(src, hoff, hend);
	273	if (hoff == (caddr_t)0) {
	274	goto bad;
	275	}
	276
	277	/*
	278	* Do not send ER if we generated the packet.
	279	*/
	280	if (clnp_ours(&src))
	281	goto bad;
	282
	283	/*
	284	* Trim mbuf to hold only the header.
	285	* This mbuf will be the 'data' of the er pdu
	286	*/
	287	if (m->m_next != NULL) {
	288	m_freem(m->m_next);
	289	m->m_next = NULL;
	290	}
	291
	292	if (m->m_len > clnp->cnf_hdr_len)
	293	m_adj(m, (int)-(m->m_len - (int)clnp->cnf_hdr_len));
	294
	295	/* route er pdu: note we send pkt to src of original packet */
	296	if (clnp_route(&src, &route, /* flags */0, &first_hop, &ia) != 0)
	297	goto bad;
	298
	299	/* compute our address based upon firsthop/ifp */
	300	if (ia)
	301	our_addr = &ia->ia_addr.siso_addr;
302	else
303	goto bad;
304	ifp = ia->ia_ifp;
305
306	IFDEBUG(D_DISCARD)
307	printf("clnp_emit_er: to %s", clnp_iso_addrp(&src));
308	printf(" from %s\n", clnp_iso_addrp(our_addr));
309	ENDDEBUG
310
311	IFDEBUG(D_DISCARD)
312	printf("clnp_emit_er: packet routed to %s\n",
313	clnp_iso_addrp(&((struct sockaddr_iso *)first_hop)->siso_addr));
314	ENDDEBUG
315
316	/* allocate mbuf for er pdu header: punt on no space */
317	MGET(m0, M_DONTWAIT, MT_HEADER);
318	if (m0 == 0)
319	goto bad;
320
321	m0->m_next = m;
322	er = mtod(m0, struct clnp_fixed *);
323	*er = er_template;
324
325	/* setup src/dst on er pdu */
326	/* NOTE REVERSAL OF SRC/DST */
327	hoff = (caddr_t)er + sizeof(struct clnp_fixed);
328	CLNP_INSERT_ADDR(hoff, src);
329	CLNP_INSERT_ADDR(hoff, *our_addr);
330
331	/*
332	* TODO: if complete src rt was specified, then reverse path, and
333	* copy into er as option.
334	*/
335
336	/* add er option */
337	hoff++ = CLNPOVAL_ERREAS; / code */
338	hoff++ = 2; / length */
339	hoff++ = reason; / discard reason */
340	hoff++ = 0; / error localization = not specified */
341
342	/* set length */
343	er->cnf_hdr_len = m0->m_len = (u_char)(hoff - (caddr_t)er);
344	total_len = m0->m_len + m->m_len;
345	HTOC(er->cnf_seglen_msb, er->cnf_seglen_lsb, total_len);
346
347	/* compute checksum (on header only) */
348	iso_gen_csum(m0, CLNP_CKSUM_OFF, (int)er->cnf_hdr_len);
349
350	/* trim packet if too large for interface */
351	if (total_len > ifp->if_mtu)
352	m_adj(m0, -(total_len - ifp->if_mtu));
353
354	/* send packet */
355	INCSTAT(cns_er_outhist[clnp_er_index(reason)]);
356	(void) (*ifp->if_output)(ifp, m0, first_hop, route.ro_rt);
357	goto done;
358
359	bad:
360	m_freem(m);
361
362	done:
363	/* free route if it is a temp */
364	if (route.ro_rt != NULL)
365	RTFREE(route.ro_rt);
366	}
367
4c45483e	368	int
15637ed4	369	clnp_er_index(p)
4c45483e	370	u_char p;
15637ed4 RG	371	{
	372	register u_char *cp = clnp_er_codes + CLNP_ERRORS;
	373	while (cp > clnp_er_codes) {
	374	cp--;
	375	if (*cp == p)
	376	return (cp - clnp_er_codes);
	377	}
	378	return (CLNP_ERRORS + 1);
	379	}