[unix-history] / usr / src / sys / netns / ns_input.c

/*
 * Copyright (c) 1984, 1985, 1986, 1987 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by the University of California, Berkeley.  The name of the
 * University may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 *
 *	@(#)ns_input.c	7.5 (Berkeley) %G%
 */

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

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

#include "ns.h"
#include "ns_if.h"
#include "ns_pcb.h"
#include "idp.h"
#include "idp_var.h"
#include "ns_error.h"

/*
 * NS initialization.
 */
union ns_host	ns_thishost;
union ns_host	ns_zerohost;
union ns_host	ns_broadhost;
union ns_net	ns_zeronet;
union ns_net	ns_broadnet;

static u_short allones[] = {-1, -1, -1};

struct nspcb nspcb;
struct nspcb nsrawpcb;

struct ifqueue	nsintrq;
int	nsqmaxlen = IFQ_MAXLEN;

int	idpcksum = 1;
long	ns_pexseq;

ns_init()
{
	extern struct timeval time;

	ns_broadhost = * (union ns_host *) allones;
	ns_broadnet = * (union ns_net *) allones;
	nspcb.nsp_next = nspcb.nsp_prev = &nspcb;
	nsrawpcb.nsp_next = nsrawpcb.nsp_prev = &nsrawpcb;
	nsintrq.ifq_maxlen = nsqmaxlen;
	ns_pexseq = time.tv_usec;
}

/*
 * Idp input routine.  Pass to next level.
 */
int nsintr_getpck = 0;
int nsintr_swtch = 0;
nsintr()
{
	register struct idp *idp;
	register struct mbuf *m;
	register struct nspcb *nsp;
	struct ifnet *ifp;
	struct mbuf *m0;
	register int i;
	int len, s, error;
	char oddpacketp;

next:
	/*
	 * Get next datagram off input queue and get IDP header
	 * in first mbuf.
	 */
	s = splimp();
	IF_DEQUEUE(&nsintrq, m);
	splx(s);
	nsintr_getpck++;
	if (m == 0)
		return;
	if ((m->m_flags & M_EXT || m->m_len < sizeof (struct idp)) &&
	    (m = m_pullup(m, sizeof (struct idp))) == 0) {
		idpstat.idps_toosmall++;
		goto next;
	}

	/*
	 * Give any raw listeners a crack at the packet
	 */
	for (nsp = nsrawpcb.nsp_next; nsp != &nsrawpcb; nsp = nsp->nsp_next) {
		struct mbuf *m1 = m_copy(m, 0, (int)M_COPYALL);
		if (m1) idp_input(m1, nsp);
	}

	idp = mtod(m, struct idp *);
	len = ntohs(idp->idp_len);
	if (oddpacketp = len & 1) {
		len++;		/* If this packet is of odd length,
				   preserve garbage byte for checksum */
	}

	/*
	 * Check that the amount of data in the buffers
	 * is as at least much as the IDP header would have us expect.
	 * Trim mbufs if longer than we expect.
	 * Drop packet if shorter than we expect.
	 */
	if (m->m_pkthdr.len < len) {
		idpstat.idps_tooshort++;
		goto bad;
	}
	if (m->m_pkthdr.len > len) {
		if (m->m_len == m->m_pkthdr.len) {
			m->m_len = len;
			m->m_pkthdr.len = len;
		} else
			m_adj(m, len - m->m_pkthdr.len);
	}
	if (idpcksum && ((i = idp->idp_sum)!=0xffff)) {
		idp->idp_sum = 0;
		if (i != (idp->idp_sum = ns_cksum(m, len))) {
			idpstat.idps_badsum++;
			idp->idp_sum = i;
			if (ns_hosteqnh(ns_thishost, idp->idp_dna.x_host))
				error = NS_ERR_BADSUM;
			else
				error = NS_ERR_BADSUM_T;
			ns_error(m, error, 0);
			goto next;
		}
	}
	/*
	 * Is this a directed broadcast?
	 */
	if (ns_hosteqnh(ns_broadhost,idp->idp_dna.x_host)) {
		if ((!ns_neteq(idp->idp_dna, idp->idp_sna)) &&
		    (!ns_neteqnn(idp->idp_dna.x_net, ns_broadnet)) &&
		    (!ns_neteqnn(idp->idp_sna.x_net, ns_zeronet)) &&
		    (!ns_neteqnn(idp->idp_dna.x_net, ns_zeronet)) ) {
			/*
			 * Look to see if I need to eat this packet.
			 * Algorithm is to forward all young packets
			 * and prematurely age any packets which will
			 * by physically broadcasted.
			 * Any very old packets eaten without forwarding
			 * would die anyway.
			 *
			 * Suggestion of Bill Nesheim, Cornell U.
			 */
			if (idp->idp_tc < NS_MAXHOPS) {
				idp_forward(m);
				goto next;
			}
		}
	/*
	 * Is this our packet? If not, forward.
	 */
	} else if (!ns_hosteqnh(ns_thishost,idp->idp_dna.x_host)) {
		idp_forward(m);
		goto next;
	}
	/*
	 * Locate pcb for datagram.
	 */
	nsp = ns_pcblookup(&idp->idp_sna, idp->idp_dna.x_port, NS_WILDCARD);
	/*
	 * Switch out to protocol's input routine.
	 */
	nsintr_swtch++;
	if (nsp) {
		if (oddpacketp) {
			m_adj(m, -1);
		}
		if ((nsp->nsp_flags & NSP_ALL_PACKETS)==0)
			switch (idp->idp_pt) {

			    case NSPROTO_SPP:
				    spp_input(m, nsp);
				    goto next;

			    case NSPROTO_ERROR:
				    ns_err_input(m);
				    goto next;
			}
		idp_input(m, nsp);
	} else {
		ns_error(m, NS_ERR_NOSOCK, 0);
	}
	goto next;

bad:
	m_freem(m);
	goto next;
}

u_char nsctlerrmap[PRC_NCMDS] = {
	ECONNABORTED,	ECONNABORTED,	0,		0,
	0,		0,		EHOSTDOWN,	EHOSTUNREACH,
	ENETUNREACH,	EHOSTUNREACH,	ECONNREFUSED,	ECONNREFUSED,
	EMSGSIZE,	0,		0,		0,
	0,		0,		0,		0
};

idp_donosocks = 1;

idp_ctlinput(cmd, arg)
	int cmd;
	caddr_t arg;
{
	struct ns_addr *ns;
	struct nspcb *nsp;
	struct ns_errp *errp;
	int idp_abort();
	extern struct nspcb *idp_drop();
	int type;

	if (cmd < 0 || cmd > PRC_NCMDS)
		return;
	if (nsctlerrmap[cmd] == 0)
		return;		/* XXX */
	type = NS_ERR_UNREACH_HOST;
	switch (cmd) {
		struct sockaddr_ns *sns;

	case PRC_IFDOWN:
	case PRC_HOSTDEAD:
	case PRC_HOSTUNREACH:
		sns = (struct sockaddr_ns *)arg;
		if (sns->sns_family != AF_INET)
			return;
		ns = &sns->sns_addr;
		break;

	default:
		errp = (struct ns_errp *)arg;
		ns = &errp->ns_err_idp.idp_dna;
		type = errp->ns_err_num;
		type = ntohs((u_short)type);
	}
	switch (type) {

	case NS_ERR_UNREACH_HOST:
		ns_pcbnotify(ns, (int)nsctlerrmap[cmd], idp_abort, (long)0);
		break;

	case NS_ERR_NOSOCK:
		nsp = ns_pcblookup(ns, errp->ns_err_idp.idp_sna.x_port,
			NS_WILDCARD);
		if(nsp && idp_donosocks && ! ns_nullhost(nsp->nsp_faddr))
			(void) idp_drop(nsp, (int)nsctlerrmap[cmd]);
	}
}

int	idpprintfs = 0;
int	idpforwarding = 1;
/*
 * Forward a packet.  If some error occurs return the sender
 * an error packet.  Note we can't always generate a meaningful
 * error message because the NS errors don't have a large enough repetoire
 * of codes and types.
 */
struct route idp_droute;
struct route idp_sroute;

idp_forward(m)
struct mbuf *m;
{
	register struct idp *idp = mtod(m, struct idp *);
	register int error, type, code;
	struct mbuf *mcopy = NULL;
	int agedelta = 1;
	int flags = NS_FORWARDING;
	int ok_there = 0;
	int ok_back = 0;

	if (idpprintfs) {
		printf("forward: src ");
		ns_printhost(&idp->idp_sna);
		printf(", dst ");
		ns_printhost(&idp->idp_dna);
		printf("hop count %d\n", idp->idp_tc);
	}
	if (idpforwarding == 0) {
		/* can't tell difference between net and host */
		type = NS_ERR_UNREACH_HOST, code = 0;
		goto senderror;
	}
	idp->idp_tc++;
	if (idp->idp_tc > NS_MAXHOPS) {
		type = NS_ERR_TOO_OLD, code = 0;
		goto senderror;
	}
	/*
	 * Save at most 42 bytes of the packet in case
	 * we need to generate an NS error message to the src.
	 */
	mcopy = m_copy(m, 0, imin((int)ntohs(idp->idp_len), 42));

	if ((ok_there = idp_do_route(&idp->idp_dna,&idp_droute))==0) {
		type = NS_ERR_UNREACH_HOST, code = 0;
		goto senderror;
	}
	/*
	 * Here we think about  forwarding  broadcast packets,
	 * so we try to insure that it doesn't go back out
	 * on the interface it came in on.  Also, if we
	 * are going to physically broadcast this, let us
	 * age the packet so we can eat it safely the second time around.
	 */
	if (idp->idp_dna.x_host.c_host[0] & 0x1) {
		struct ns_ifaddr *ia = ns_iaonnetof(&idp->idp_dna);
		struct ifnet *ifp;
		if (ia) {
			/* I'm gonna hafta eat this packet */
			agedelta += NS_MAXHOPS - idp->idp_tc;
			idp->idp_tc = NS_MAXHOPS;
		}
		if ((ok_back = idp_do_route(&idp->idp_sna,&idp_sroute))==0) {
			/* error = ENETUNREACH; He'll never get it! */
			m_freem(m);
			goto cleanup;
		}
		if (idp_droute.ro_rt &&
		    (ifp=idp_droute.ro_rt->rt_ifp) &&
		    idp_sroute.ro_rt &&
		    (ifp!=idp_sroute.ro_rt->rt_ifp)) {
			flags |= NS_ALLOWBROADCAST;
		} else {
			type = NS_ERR_UNREACH_HOST, code = 0;
			goto senderror;
		}
	}
	/* need to adjust checksum */
	if (idp->idp_sum!=0xffff) {
		union bytes {
			u_char c[4];
			u_short s[2];
			long l;
		} x;
		register int shift;
		x.l = 0; x.c[0] = agedelta;
		shift = (((((int)ntohs(idp->idp_len))+1)>>1)-2) & 0xf;
		x.l = idp->idp_sum + (x.s[0] << shift);
		x.l = x.s[0] + x.s[1];
		x.l = x.s[0] + x.s[1];
		if (x.l==0xffff) idp->idp_sum = 0; else idp->idp_sum = x.l;
	}
	if ((error = ns_output(m, &idp_droute, flags)) && 
	    (mcopy!=NULL)) {
		idp = mtod(mcopy, struct idp *);
		type = NS_ERR_UNSPEC_T, code = 0;
		switch (error) {

		case ENETUNREACH:
		case EHOSTDOWN:
		case EHOSTUNREACH:
		case ENETDOWN:
		case EPERM:
			type = NS_ERR_UNREACH_HOST;
			break;

		case EMSGSIZE:
			type = NS_ERR_TOO_BIG;
			code = 576; /* too hard to figure out mtu here */
			break;

		case ENOBUFS:
			type = NS_ERR_UNSPEC_T;
			break;
		}
		mcopy = NULL;
	senderror:
		ns_error(m, type, code);
	}
cleanup:
	if (ok_there)
		idp_undo_route(&idp_droute);
	if (ok_back)
		idp_undo_route(&idp_sroute);
	if (mcopy != NULL)
		m_freem(mcopy);
}

idp_do_route(src, ro)
struct ns_addr *src;
struct route *ro;
{
	
	struct sockaddr_ns *dst;

	bzero((caddr_t)ro, sizeof (*ro));
	dst = (struct sockaddr_ns *)&ro->ro_dst;

	dst->sns_family = AF_NS;
	dst->sns_addr = *src;
	dst->sns_addr.x_port = 0;
	rtalloc(ro);
	if (ro->ro_rt == 0 || ro->ro_rt->rt_ifp == 0) {
		return (0);
	}
	ro->ro_rt->rt_use++;
	return (1);
}

idp_undo_route(ro)
register struct route *ro;
{
	if (ro->ro_rt) {RTFREE(ro->ro_rt);}
}
static union ns_net
ns_zeronet;

ns_watch_output(m, ifp)
struct mbuf *m;
struct ifnet *ifp;
{
	register struct nspcb *nsp;
	register struct ifaddr *ia;
	/*
	 * Give any raw listeners a crack at the packet
	 */
	for (nsp = nsrawpcb.nsp_next; nsp != &nsrawpcb; nsp = nsp->nsp_next) {
		struct mbuf *m0 = m_copy(m, 0, (int)M_COPYALL);
		if (m0) {
			register struct idp *idp;

			M_PREPEND(m0, sizeof (*idp), M_DONTWAIT);
			if (m0 == NULL)
				continue;
			idp = mtod(m0, struct idp *);
			idp->idp_sna.x_net = ns_zeronet;
			idp->idp_sna.x_host = ns_thishost;
			if (ifp && (ifp->if_flags & IFF_POINTOPOINT))
			    for(ia = ifp->if_addrlist; ia;
						ia = ia->ifa_next) {
				if (ia->ifa_addr.sa_family==AF_NS) {
				    idp->idp_sna = 
					satons_addr(ia->ifa_dstaddr);
				    break;
				}
			    }
			idp->idp_len = ntohl(m0->m_pkthdr.len);
			idp_input(m0, nsp);
		}
	}
}
Commit	Line	Data
8ae0e4b4	1	/*
240edf1f KS	2	* Copyright (c) 1984, 1985, 1986, 1987 Regents of the University of California.
240edf1f KS	3	* All rights reserved.
8ae0e4b4	4	*
240edf1f	5	* Redistribution and use in source and binary forms are permitted
616d42db KB	6	* provided that the above copyright notice and this paragraph are
	7	* duplicated in all such forms and that any documentation,
	8	* advertising materials, and other materials related to such
	9	* distribution and use acknowledge that the software was developed
	10	* by the University of California, Berkeley. The name of the
	11	* University may not be used to endorse or promote products derived
	12	* from this software without specific prior written permission.
	13	* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
	14	* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
	15	* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
240edf1f	16	*
bf8d7cff	17	* @(#)ns_input.c 7.5 (Berkeley) %G%
8ae0e4b4	18	*/
bbcda6f4 KS	19
	20	#include "param.h"
	21	#include "systm.h"
bf8d7cff	22	#include "malloc.h"
bbcda6f4 KS	23	#include "mbuf.h"
	24	#include "domain.h"
	25	#include "protosw.h"
	26	#include "socket.h"
	27	#include "socketvar.h"
	28	#include "errno.h"
	29	#include "time.h"
	30	#include "kernel.h"
	31
	32	#include "../net/if.h"
	33	#include "../net/route.h"
	34	#include "../net/raw_cb.h"
	35
	36	#include "ns.h"
	37	#include "ns_if.h"
	38	#include "ns_pcb.h"
	39	#include "idp.h"
	40	#include "idp_var.h"
	41	#include "ns_error.h"
	42
	43	/*
	44	* NS initialization.
	45	*/
	46	union ns_host ns_thishost;
	47	union ns_host ns_zerohost;
	48	union ns_host ns_broadhost;
f1e269d4 KS	49	union ns_net ns_zeronet;
f1e269d4 KS	50	union ns_net ns_broadnet;
bbcda6f4	51
f1e269d4	52	static u_short allones[] = {-1, -1, -1};
bbcda6f4 KS	53
	54	struct nspcb nspcb;
	55	struct nspcb nsrawpcb;
	56
	57	struct ifqueue nsintrq;
	58	int nsqmaxlen = IFQ_MAXLEN;
	59
350dbdec	60	int idpcksum = 1;
623533cc	61	long ns_pexseq;
bbcda6f4 KS	62
	63	ns_init()
	64	{
623533cc KS	65	extern struct timeval time;
623533cc KS	66
bbcda6f4	67	ns_broadhost = * (union ns_host *) allones;
f1e269d4	68	ns_broadnet = * (union ns_net *) allones;
bbcda6f4 KS	69	nspcb.nsp_next = nspcb.nsp_prev = &nspcb;
	70	nsrawpcb.nsp_next = nsrawpcb.nsp_prev = &nsrawpcb;
	71	nsintrq.ifq_maxlen = nsqmaxlen;
623533cc	72	ns_pexseq = time.tv_usec;
bbcda6f4 KS	73	}
	74
	75	/*
	76	* Idp input routine. Pass to next level.
	77	*/
	78	int nsintr_getpck = 0;
	79	int nsintr_swtch = 0;
	80	nsintr()
	81	{
	82	register struct idp *idp;
	83	register struct mbuf *m;
19d8bb77	84	register struct nspcb *nsp;
47685d3d	85	struct ifnet *ifp;
bbcda6f4 KS	86	struct mbuf *m0;
	87	register int i;
	88	int len, s, error;
	89	char oddpacketp;
	90
	91	next:
	92	/*
	93	* Get next datagram off input queue and get IDP header
	94	* in first mbuf.
	95	*/
	96	s = splimp();
bf8d7cff	97	IF_DEQUEUE(&nsintrq, m);
bbcda6f4 KS	98	splx(s);
	99	nsintr_getpck++;
	100	if (m == 0)
	101	return;
bf8d7cff	102	if ((m->m_flags & M_EXT \|\| m->m_len < sizeof (struct idp)) &&
bbcda6f4 KS	103	(m = m_pullup(m, sizeof (struct idp))) == 0) {
	104	idpstat.idps_toosmall++;
	105	goto next;
	106	}
	107
	108	/*
	109	* Give any raw listeners a crack at the packet
	110	*/
	111	for (nsp = nsrawpcb.nsp_next; nsp != &nsrawpcb; nsp = nsp->nsp_next) {
f97be0c9	112	struct mbuf *m1 = m_copy(m, 0, (int)M_COPYALL);
bf8d7cff	113	if (m1) idp_input(m1, nsp);
bbcda6f4 KS	114	}
	115
	116	idp = mtod(m, struct idp *);
	117	len = ntohs(idp->idp_len);
	118	if (oddpacketp = len & 1) {
	119	len++; /* If this packet is of odd length,
	120	preserve garbage byte for checksum */
	121	}
	122
	123	/*
	124	* Check that the amount of data in the buffers
	125	* is as at least much as the IDP header would have us expect.
	126	* Trim mbufs if longer than we expect.
	127	* Drop packet if shorter than we expect.
	128	*/
bf8d7cff KS	129	if (m->m_pkthdr.len < len) {
	130	idpstat.idps_tooshort++;
	131	goto bad;
bbcda6f4	132	}
bf8d7cff KS	133	if (m->m_pkthdr.len > len) {
	134	if (m->m_len == m->m_pkthdr.len) {
	135	m->m_len = len;
	136	m->m_pkthdr.len = len;
	137	} else
	138	m_adj(m, len - m->m_pkthdr.len);
bbcda6f4	139	}
bbcda6f4 KS	140	if (idpcksum && ((i = idp->idp_sum)!=0xffff)) {
bbcda6f4 KS	141	idp->idp_sum = 0;
bf8d7cff	142	if (i != (idp->idp_sum = ns_cksum(m, len))) {
bbcda6f4	143	idpstat.idps_badsum++;
623533cc	144	idp->idp_sum = i;
bbcda6f4 KS	145	if (ns_hosteqnh(ns_thishost, idp->idp_dna.x_host))
	146	error = NS_ERR_BADSUM;
	147	else
	148	error = NS_ERR_BADSUM_T;
	149	ns_error(m, error, 0);
	150	goto next;
	151	}
	152	}
	153	/*
	154	* Is this a directed broadcast?
	155	*/
	156	if (ns_hosteqnh(ns_broadhost,idp->idp_dna.x_host)) {
f1e269d4 KS	157	if ((!ns_neteq(idp->idp_dna, idp->idp_sna)) &&
	158	(!ns_neteqnn(idp->idp_dna.x_net, ns_broadnet)) &&
	159	(!ns_neteqnn(idp->idp_sna.x_net, ns_zeronet)) &&
	160	(!ns_neteqnn(idp->idp_dna.x_net, ns_zeronet)) ) {
bbcda6f4	161	/*
c7ea7bd3 KS	162	* Look to see if I need to eat this packet.
	163	* Algorithm is to forward all young packets
	164	* and prematurely age any packets which will
	165	* by physically broadcasted.
	166	* Any very old packets eaten without forwarding
	167	* would die anyway.
	168	*
	169	* Suggestion of Bill Nesheim, Cornell U.
bbcda6f4	170	*/
350dbdec	171	if (idp->idp_tc < NS_MAXHOPS) {
bf8d7cff	172	idp_forward(m);
bbcda6f4	173	goto next;
c7ea7bd3	174	}
bbcda6f4 KS	175	}
	176	/*
	177	* Is this our packet? If not, forward.
	178	*/
	179	} else if (!ns_hosteqnh(ns_thishost,idp->idp_dna.x_host)) {
bf8d7cff	180	idp_forward(m);
bbcda6f4 KS	181	goto next;
bbcda6f4 KS	182	}
19d8bb77 KS	183	/*
	184	* Locate pcb for datagram.
	185	*/
	186	nsp = ns_pcblookup(&idp->idp_sna, idp->idp_dna.x_port, NS_WILDCARD);
	187	/*
	188	* Switch out to protocol's input routine.
	189	*/
	190	nsintr_swtch++;
	191	if (nsp) {
	192	if (oddpacketp) {
bf8d7cff	193	m_adj(m, -1);
19d8bb77 KS	194	}
	195	if ((nsp->nsp_flags & NSP_ALL_PACKETS)==0)
	196	switch (idp->idp_pt) {
350dbdec	197
19d8bb77	198	case NSPROTO_SPP:
bf8d7cff	199	spp_input(m, nsp);
19d8bb77	200	goto next;
350dbdec	201
19d8bb77 KS	202	case NSPROTO_ERROR:
	203	ns_err_input(m);
	204	goto next;
	205	}
bf8d7cff	206	idp_input(m, nsp);
19d8bb77 KS	207	} else {
19d8bb77 KS	208	ns_error(m, NS_ERR_NOSOCK, 0);
bbcda6f4 KS	209	}
	210	goto next;
	211
	212	bad:
	213	m_freem(m);
	214	goto next;
	215	}
	216
	217	u_char nsctlerrmap[PRC_NCMDS] = {
	218	ECONNABORTED, ECONNABORTED, 0, 0,
	219	0, 0, EHOSTDOWN, EHOSTUNREACH,
	220	ENETUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED,
	221	EMSGSIZE, 0, 0, 0,
	222	0, 0, 0, 0
	223	};
	224
623533cc KS	225	idp_donosocks = 1;
623533cc KS	226
bbcda6f4 KS	227	idp_ctlinput(cmd, arg)
	228	int cmd;
	229	caddr_t arg;
	230	{
	231	struct ns_addr *ns;
623533cc KS	232	struct nspcb *nsp;
623533cc KS	233	struct ns_errp *errp;
bbcda6f4	234	int idp_abort();
f97be0c9	235	extern struct nspcb *idp_drop();
bbcda6f4 KS	236	int type;
	237
	238	if (cmd < 0 \|\| cmd > PRC_NCMDS)
	239	return;
	240	if (nsctlerrmap[cmd] == 0)
	241	return; /* XXX */
	242	type = NS_ERR_UNREACH_HOST;
d2ec0713 KS	243	switch (cmd) {
	244	struct sockaddr_ns *sns;
	245
	246	case PRC_IFDOWN:
	247	case PRC_HOSTDEAD:
	248	case PRC_HOSTUNREACH:
	249	sns = (struct sockaddr_ns *)arg;
	250	if (sns->sns_family != AF_INET)
	251	return;
	252	ns = &sns->sns_addr;
	253	break;
	254
	255	default:
623533cc KS	256	errp = (struct ns_errp *)arg;
	257	ns = &errp->ns_err_idp.idp_dna;
	258	type = errp->ns_err_num;
f97be0c9	259	type = ntohs((u_short)type);
bbcda6f4 KS	260	}
bbcda6f4 KS	261	switch (type) {
350dbdec	262
bbcda6f4	263	case NS_ERR_UNREACH_HOST:
f97be0c9	264	ns_pcbnotify(ns, (int)nsctlerrmap[cmd], idp_abort, (long)0);
623533cc KS	265	break;
	266
	267	case NS_ERR_NOSOCK:
	268	nsp = ns_pcblookup(ns, errp->ns_err_idp.idp_sna.x_port,
	269	NS_WILDCARD);
	270	if(nsp && idp_donosocks && ! ns_nullhost(nsp->nsp_faddr))
f97be0c9	271	(void) idp_drop(nsp, (int)nsctlerrmap[cmd]);
bbcda6f4 KS	272	}
	273	}
	274
	275	int idpprintfs = 0;
	276	int idpforwarding = 1;
	277	/*
	278	* Forward a packet. If some error occurs return the sender
	279	* an error packet. Note we can't always generate a meaningful
	280	* error message because the NS errors don't have a large enough repetoire
	281	* of codes and types.
	282	*/
	283	struct route idp_droute;
	284	struct route idp_sroute;
	285
bf8d7cff KS	286	idp_forward(m)
bf8d7cff KS	287	struct mbuf *m;
bbcda6f4	288	{
bf8d7cff	289	register struct idp idp = mtod(m, struct idp );
bbcda6f4	290	register int error, type, code;
c7ea7bd3 KS	291	struct mbuf *mcopy = NULL;
	292	int agedelta = 1;
	293	int flags = NS_FORWARDING;
	294	int ok_there = 0;
	295	int ok_back = 0;
bbcda6f4 KS	296
	297	if (idpprintfs) {
	298	printf("forward: src ");
	299	ns_printhost(&idp->idp_sna);
	300	printf(", dst ");
	301	ns_printhost(&idp->idp_dna);
	302	printf("hop count %d\n", idp->idp_tc);
	303	}
	304	if (idpforwarding == 0) {
	305	/* can't tell difference between net and host */
	306	type = NS_ERR_UNREACH_HOST, code = 0;
	307	goto senderror;
	308	}
	309	idp->idp_tc++;
	310	if (idp->idp_tc > NS_MAXHOPS) {
	311	type = NS_ERR_TOO_OLD, code = 0;
	312	goto senderror;
	313	}
c7ea7bd3 KS	314	/*
	315	* Save at most 42 bytes of the packet in case
	316	* we need to generate an NS error message to the src.
	317	*/
bf8d7cff	318	mcopy = m_copy(m, 0, imin((int)ntohs(idp->idp_len), 42));
c7ea7bd3	319
350dbdec	320	if ((ok_there = idp_do_route(&idp->idp_dna,&idp_droute))==0) {
c7ea7bd3 KS	321	type = NS_ERR_UNREACH_HOST, code = 0;
	322	goto senderror;
	323	}
	324	/*
	325	* Here we think about forwarding broadcast packets,
	326	* so we try to insure that it doesn't go back out
	327	* on the interface it came in on. Also, if we
	328	* are going to physically broadcast this, let us
	329	* age the packet so we can eat it safely the second time around.
	330	*/
	331	if (idp->idp_dna.x_host.c_host[0] & 0x1) {
b59145f1	332	struct ns_ifaddr *ia = ns_iaonnetof(&idp->idp_dna);
c7ea7bd3 KS	333	struct ifnet *ifp;
	334	if (ia) {
	335	/* I'm gonna hafta eat this packet */
	336	agedelta += NS_MAXHOPS - idp->idp_tc;
	337	idp->idp_tc = NS_MAXHOPS;
	338	}
	339	if ((ok_back = idp_do_route(&idp->idp_sna,&idp_sroute))==0) {
	340	/* error = ENETUNREACH; He'll never get it! */
bf8d7cff	341	m_freem(m);
c7ea7bd3 KS	342	goto cleanup;
	343	}
	344	if (idp_droute.ro_rt &&
	345	(ifp=idp_droute.ro_rt->rt_ifp) &&
	346	idp_sroute.ro_rt &&
	347	(ifp!=idp_sroute.ro_rt->rt_ifp)) {
	348	flags \|= NS_ALLOWBROADCAST;
	349	} else {
	350	type = NS_ERR_UNREACH_HOST, code = 0;
	351	goto senderror;
	352	}
	353	}
bbcda6f4 KS	354	/* need to adjust checksum */
	355	if (idp->idp_sum!=0xffff) {
	356	union bytes {
	357	u_char c[4];
	358	u_short s[2];
	359	long l;
	360	} x;
	361	register int shift;
c7ea7bd3	362	x.l = 0; x.c[0] = agedelta;
bbcda6f4	363	shift = (((((int)ntohs(idp->idp_len))+1)>>1)-2) & 0xf;
3364af6f	364	x.l = idp->idp_sum + (x.s[0] << shift);
bbcda6f4 KS	365	x.l = x.s[0] + x.s[1];
	366	x.l = x.s[0] + x.s[1];
	367	if (x.l==0xffff) idp->idp_sum = 0; else idp->idp_sum = x.l;
	368	}
bf8d7cff	369	if ((error = ns_output(m, &idp_droute, flags)) &&
c7ea7bd3 KS	370	(mcopy!=NULL)) {
	371	idp = mtod(mcopy, struct idp *);
	372	type = NS_ERR_UNSPEC_T, code = 0;
	373	switch (error) {
	374
	375	case ENETUNREACH:
	376	case EHOSTDOWN:
	377	case EHOSTUNREACH:
	378	case ENETDOWN:
	379	case EPERM:
	380	type = NS_ERR_UNREACH_HOST;
	381	break;
bbcda6f4	382
c7ea7bd3 KS	383	case EMSGSIZE:
	384	type = NS_ERR_TOO_BIG;
	385	code = 576; /* too hard to figure out mtu here */
	386	break;
bbcda6f4	387
c7ea7bd3 KS	388	case ENOBUFS:
	389	type = NS_ERR_UNSPEC_T;
	390	break;
bbcda6f4	391	}
0ff552c7 KS	392	mcopy = NULL;
0ff552c7 KS	393	senderror:
bf8d7cff	394	ns_error(m, type, code);
bbcda6f4	395	}
c7ea7bd3 KS	396	cleanup:
	397	if (ok_there)
	398	idp_undo_route(&idp_droute);
	399	if (ok_back)
	400	idp_undo_route(&idp_sroute);
	401	if (mcopy != NULL)
	402	m_freem(mcopy);
bbcda6f4 KS	403	}
	404
	405	idp_do_route(src, ro)
	406	struct ns_addr *src;
	407	struct route *ro;
	408	{
	409
	410	struct sockaddr_ns *dst;
	411
	412	bzero((caddr_t)ro, sizeof (*ro));
	413	dst = (struct sockaddr_ns *)&ro->ro_dst;
	414
	415	dst->sns_family = AF_NS;
	416	dst->sns_addr = *src;
350dbdec	417	dst->sns_addr.x_port = 0;
bbcda6f4 KS	418	rtalloc(ro);
bbcda6f4 KS	419	if (ro->ro_rt == 0 \|\| ro->ro_rt->rt_ifp == 0) {
350dbdec	420	return (0);
bbcda6f4 KS	421	}
bbcda6f4 KS	422	ro->ro_rt->rt_use++;
350dbdec	423	return (1);
bbcda6f4 KS	424	}
	425
	426	idp_undo_route(ro)
	427	register struct route *ro;
	428	{
	429	if (ro->ro_rt) {RTFREE(ro->ro_rt);}
	430	}
b59145f1 KS	431	static union ns_net
	432	ns_zeronet;
	433
	434	ns_watch_output(m, ifp)
bbcda6f4	435	struct mbuf *m;
b59145f1	436	struct ifnet *ifp;
bbcda6f4 KS	437	{
bbcda6f4 KS	438	register struct nspcb *nsp;
b59145f1	439	register struct ifaddr *ia;
bbcda6f4 KS	440	/*
	441	* Give any raw listeners a crack at the packet
	442	*/
	443	for (nsp = nsrawpcb.nsp_next; nsp != &nsrawpcb; nsp = nsp->nsp_next) {
b59145f1 KS	444	struct mbuf *m0 = m_copy(m, 0, (int)M_COPYALL);
b59145f1 KS	445	if (m0) {
bf8d7cff KS	446	register struct idp *idp;
	447
	448	M_PREPEND(m0, sizeof (*idp), M_DONTWAIT);
	449	if (m0 == NULL)
	450	continue;
	451	idp = mtod(m0, struct idp *);
	452	idp->idp_sna.x_net = ns_zeronet;
	453	idp->idp_sna.x_host = ns_thishost;
	454	if (ifp && (ifp->if_flags & IFF_POINTOPOINT))
	455	for(ia = ifp->if_addrlist; ia;
	456	ia = ia->ifa_next) {
	457	if (ia->ifa_addr.sa_family==AF_NS) {
	458	idp->idp_sna =
	459	satons_addr(ia->ifa_dstaddr);
	460	break;
	461	}
	462	}
	463	idp->idp_len = ntohl(m0->m_pkthdr.len);
	464	idp_input(m0, nsp);
b59145f1	465	}
bbcda6f4 KS	466	}
bbcda6f4 KS	467	}