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if_gre.c revision 1.49.2.1
      1  1.49.2.1     grant /*	$NetBSD: if_gre.c,v 1.49.2.1 2004/05/20 12:24:05 grant Exp $ */
      2       1.4   thorpej 
      3       1.1       hwr /*
      4       1.4   thorpej  * Copyright (c) 1998 The NetBSD Foundation, Inc.
      5       1.1       hwr  * All rights reserved.
      6       1.1       hwr  *
      7       1.1       hwr  * This code is derived from software contributed to The NetBSD Foundation
      8       1.1       hwr  * by Heiko W.Rupp <hwr (at) pilhuhn.de>
      9       1.1       hwr  *
     10       1.1       hwr  * Redistribution and use in source and binary forms, with or without
     11       1.1       hwr  * modification, are permitted provided that the following conditions
     12       1.1       hwr  * are met:
     13       1.1       hwr  * 1. Redistributions of source code must retain the above copyright
     14       1.1       hwr  *    notice, this list of conditions and the following disclaimer.
     15       1.1       hwr  * 2. Redistributions in binary form must reproduce the above copyright
     16       1.1       hwr  *    notice, this list of conditions and the following disclaimer in the
     17       1.1       hwr  *    documentation and/or other materials provided with the distribution.
     18       1.1       hwr  * 3. All advertising materials mentioning features or use of this software
     19       1.1       hwr  *    must display the following acknowledgement:
     20       1.1       hwr  *        This product includes software developed by the NetBSD
     21       1.1       hwr  *        Foundation, Inc. and its contributors.
     22       1.1       hwr  * 4. Neither the name of The NetBSD Foundation nor the names of its
     23       1.1       hwr  *    contributors may be used to endorse or promote products derived
     24       1.1       hwr  *    from this software without specific prior written permission.
     25       1.1       hwr  *
     26       1.1       hwr  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     27       1.1       hwr  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     28       1.1       hwr  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     29       1.1       hwr  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     30       1.1       hwr  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     31       1.1       hwr  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     32       1.1       hwr  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     33       1.1       hwr  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     34       1.1       hwr  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     35       1.1       hwr  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     36       1.1       hwr  * POSSIBILITY OF SUCH DAMAGE.
     37       1.1       hwr  */
     38       1.1       hwr 
     39       1.1       hwr /*
     40       1.1       hwr  * Encapsulate L3 protocols into IP
     41       1.1       hwr  * See RFC 1701 and 1702 for more details.
     42       1.1       hwr  * If_gre is compatible with Cisco GRE tunnels, so you can
     43       1.1       hwr  * have a NetBSD box as the other end of a tunnel interface of a Cisco
     44       1.1       hwr  * router. See gre(4) for more details.
     45       1.6       hwr  * Also supported:  IP in IP encaps (proto 55) as of RFC 2004
     46       1.1       hwr  */
     47      1.22     lukem 
     48      1.22     lukem #include <sys/cdefs.h>
     49  1.49.2.1     grant __KERNEL_RCSID(0, "$NetBSD: if_gre.c,v 1.49.2.1 2004/05/20 12:24:05 grant Exp $");
     50       1.1       hwr 
     51       1.1       hwr #include "opt_inet.h"
     52       1.9  drochner #include "opt_ns.h"
     53       1.1       hwr #include "bpfilter.h"
     54       1.1       hwr 
     55       1.1       hwr #include <sys/param.h>
     56       1.1       hwr #include <sys/malloc.h>
     57       1.1       hwr #include <sys/mbuf.h>
     58      1.13    martin #include <sys/proc.h>
     59       1.1       hwr #include <sys/protosw.h>
     60       1.1       hwr #include <sys/socket.h>
     61       1.1       hwr #include <sys/ioctl.h>
     62      1.10   thorpej #include <sys/queue.h>
     63       1.1       hwr #if __NetBSD__
     64       1.1       hwr #include <sys/systm.h>
     65       1.1       hwr #endif
     66       1.1       hwr 
     67       1.1       hwr #include <machine/cpu.h>
     68       1.1       hwr 
     69       1.1       hwr #include <net/ethertypes.h>
     70       1.1       hwr #include <net/if.h>
     71       1.1       hwr #include <net/if_types.h>
     72       1.1       hwr #include <net/netisr.h>
     73       1.1       hwr #include <net/route.h>
     74       1.1       hwr 
     75       1.1       hwr #ifdef INET
     76       1.1       hwr #include <netinet/in.h>
     77       1.1       hwr #include <netinet/in_systm.h>
     78       1.1       hwr #include <netinet/in_var.h>
     79       1.1       hwr #include <netinet/ip.h>
     80       1.1       hwr #include <netinet/ip_var.h>
     81       1.1       hwr #else
     82       1.4   thorpej #error "Huh? if_gre without inet?"
     83       1.1       hwr #endif
     84       1.1       hwr 
     85       1.1       hwr #ifdef NS
     86       1.1       hwr #include <netns/ns.h>
     87       1.1       hwr #include <netns/ns_if.h>
     88       1.1       hwr #endif
     89       1.1       hwr 
     90       1.1       hwr #ifdef NETATALK
     91       1.1       hwr #include <netatalk/at.h>
     92       1.1       hwr #include <netatalk/at_var.h>
     93       1.1       hwr #include <netatalk/at_extern.h>
     94       1.1       hwr #endif
     95       1.1       hwr 
     96       1.1       hwr #if NBPFILTER > 0
     97       1.1       hwr #include <sys/time.h>
     98       1.1       hwr #include <net/bpf.h>
     99       1.1       hwr #endif
    100       1.1       hwr 
    101       1.1       hwr #include <net/if_gre.h>
    102       1.1       hwr 
    103      1.20    itojun /*
    104      1.27    martin  * It is not easy to calculate the right value for a GRE MTU.
    105      1.27    martin  * We leave this task to the admin and use the same default that
    106      1.27    martin  * other vendors use.
    107      1.20    itojun  */
    108      1.27    martin #define GREMTU 1476
    109       1.1       hwr 
    110      1.11   thorpej struct gre_softc_head gre_softc_list;
    111      1.26    martin int ip_gre_ttl = GRE_TTL;
    112       1.1       hwr 
    113      1.10   thorpej int	gre_clone_create __P((struct if_clone *, int));
    114      1.10   thorpej void	gre_clone_destroy __P((struct ifnet *));
    115      1.10   thorpej 
    116      1.10   thorpej struct if_clone gre_cloner =
    117      1.10   thorpej     IF_CLONE_INITIALIZER("gre", gre_clone_create, gre_clone_destroy);
    118       1.1       hwr 
    119      1.25    martin int gre_compute_route(struct gre_softc *sc);
    120       1.1       hwr 
    121      1.10   thorpej void	greattach __P((int));
    122      1.10   thorpej 
    123      1.10   thorpej /* ARGSUSED */
    124       1.8  explorer void
    125      1.10   thorpej greattach(count)
    126      1.10   thorpej 	int count;
    127      1.10   thorpej {
    128      1.10   thorpej 
    129      1.10   thorpej 	LIST_INIT(&gre_softc_list);
    130      1.10   thorpej 	if_clone_attach(&gre_cloner);
    131      1.10   thorpej }
    132      1.10   thorpej 
    133      1.10   thorpej int
    134      1.10   thorpej gre_clone_create(ifc, unit)
    135      1.10   thorpej 	struct if_clone *ifc;
    136      1.10   thorpej 	int unit;
    137       1.1       hwr {
    138       1.8  explorer 	struct gre_softc *sc;
    139       1.1       hwr 
    140      1.10   thorpej 	sc = malloc(sizeof(struct gre_softc), M_DEVBUF, M_WAITOK);
    141      1.10   thorpej 	memset(sc, 0, sizeof(struct gre_softc));
    142      1.10   thorpej 
    143      1.10   thorpej 	sprintf(sc->sc_if.if_xname, "%s%d", ifc->ifc_name, unit);
    144      1.10   thorpej 	sc->sc_if.if_softc = sc;
    145  1.49.2.1     grant 	sc->sc_if.if_type = IFT_TUNNEL;
    146      1.34    itojun 	sc->sc_if.if_addrlen = 0;
    147      1.10   thorpej 	sc->sc_if.if_hdrlen = 24; /* IP + GRE */
    148      1.15   thorpej 	sc->sc_if.if_dlt = DLT_NULL;
    149      1.20    itojun 	sc->sc_if.if_mtu = GREMTU;
    150      1.10   thorpej 	sc->sc_if.if_flags = IFF_POINTOPOINT|IFF_MULTICAST;
    151      1.10   thorpej 	sc->sc_if.if_output = gre_output;
    152      1.10   thorpej 	sc->sc_if.if_ioctl = gre_ioctl;
    153      1.10   thorpej 	sc->g_dst.s_addr = sc->g_src.s_addr = INADDR_ANY;
    154      1.10   thorpej 	sc->g_proto = IPPROTO_GRE;
    155      1.35    itojun 	sc->sc_if.if_flags |= IFF_LINK0;
    156      1.10   thorpej 	if_attach(&sc->sc_if);
    157      1.16   thorpej 	if_alloc_sadl(&sc->sc_if);
    158       1.1       hwr #if NBPFILTER > 0
    159      1.14   thorpej 	bpfattach(&sc->sc_if, DLT_NULL, sizeof(u_int32_t));
    160       1.1       hwr #endif
    161      1.10   thorpej 	LIST_INSERT_HEAD(&gre_softc_list, sc, sc_list);
    162      1.10   thorpej 	return (0);
    163      1.10   thorpej }
    164       1.1       hwr 
    165      1.10   thorpej void
    166      1.10   thorpej gre_clone_destroy(ifp)
    167      1.10   thorpej 	struct ifnet *ifp;
    168      1.10   thorpej {
    169      1.10   thorpej 	struct gre_softc *sc = ifp->if_softc;
    170      1.10   thorpej 
    171      1.10   thorpej 	LIST_REMOVE(sc, sc_list);
    172      1.10   thorpej #if NBPFILTER > 0
    173      1.10   thorpej 	bpfdetach(ifp);
    174      1.10   thorpej #endif
    175      1.10   thorpej 	if_detach(ifp);
    176      1.10   thorpej 	free(sc, M_DEVBUF);
    177       1.1       hwr }
    178       1.1       hwr 
    179      1.20    itojun /*
    180       1.1       hwr  * The output routine. Takes a packet and encapsulates it in the protocol
    181       1.6       hwr  * given by sc->g_proto. See also RFC 1701 and RFC 2004
    182       1.1       hwr  */
    183       1.1       hwr int
    184       1.8  explorer gre_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
    185       1.8  explorer 	   struct rtentry *rt)
    186       1.1       hwr {
    187       1.8  explorer 	int error = 0;
    188      1.10   thorpej 	struct gre_softc *sc = ifp->if_softc;
    189       1.1       hwr 	struct greip *gh;
    190      1.41    itojun 	struct ip *ip;
    191      1.48    itojun 	u_int16_t etype = 0;
    192      1.20    itojun 	struct mobile_h mob_h;
    193      1.24    martin 
    194      1.39    itojun 	if ((ifp->if_flags & (IFF_UP | IFF_RUNNING)) == 0 ||
    195      1.37    itojun 	    sc->g_src.s_addr == INADDR_ANY || sc->g_dst.s_addr == INADDR_ANY) {
    196      1.37    itojun 		m_freem(m);
    197      1.38    itojun 		error = ENETDOWN;
    198      1.38    itojun 		goto end;
    199      1.37    itojun 	}
    200       1.1       hwr 
    201       1.8  explorer 	gh = NULL;
    202      1.41    itojun 	ip = NULL;
    203       1.1       hwr 
    204       1.1       hwr #if NBPFILTER >0
    205      1.14   thorpej 	if (ifp->if_bpf) {
    206       1.1       hwr 		/* see comment of other if_foo.c files */
    207       1.1       hwr 		struct mbuf m0;
    208      1.17    itojun 		u_int32_t af = dst->sa_family;
    209       1.1       hwr 
    210       1.8  explorer 		m0.m_next = m;
    211       1.8  explorer 		m0.m_len = 4;
    212       1.1       hwr 		m0.m_data = (char *)&af;
    213      1.20    itojun 
    214      1.14   thorpej 		bpf_mtap(ifp->if_bpf, &m0);
    215       1.1       hwr 	}
    216       1.1       hwr #endif
    217       1.1       hwr 
    218      1.26    martin 	m->m_flags &= ~(M_BCAST|M_MCAST);
    219       1.1       hwr 
    220       1.5   thorpej 	if (sc->g_proto == IPPROTO_MOBILE) {
    221       1.3       hwr 		if (dst->sa_family == AF_INET) {
    222       1.3       hwr 			struct mbuf *m0;
    223       1.3       hwr 			int msiz;
    224       1.3       hwr 
    225      1.41    itojun 			ip = mtod(m, struct ip *);
    226       1.3       hwr 
    227       1.8  explorer 			memset(&mob_h, 0, MOB_H_SIZ_L);
    228      1.41    itojun 			mob_h.proto = (ip->ip_p) << 8;
    229      1.41    itojun 			mob_h.odst = ip->ip_dst.s_addr;
    230      1.41    itojun 			ip->ip_dst.s_addr = sc->g_dst.s_addr;
    231       1.3       hwr 
    232       1.3       hwr 			/*
    233       1.8  explorer 			 * If the packet comes from our host, we only change
    234       1.8  explorer 			 * the destination address in the IP header.
    235       1.8  explorer 			 * Else we also need to save and change the source
    236       1.3       hwr 			 */
    237      1.41    itojun 			if (in_hosteq(ip->ip_src, sc->g_src)) {
    238       1.8  explorer 				msiz = MOB_H_SIZ_S;
    239       1.3       hwr 			} else {
    240       1.3       hwr 				mob_h.proto |= MOB_H_SBIT;
    241      1.41    itojun 				mob_h.osrc = ip->ip_src.s_addr;
    242      1.41    itojun 				ip->ip_src.s_addr = sc->g_src.s_addr;
    243       1.8  explorer 				msiz = MOB_H_SIZ_L;
    244       1.3       hwr 			}
    245       1.3       hwr 			HTONS(mob_h.proto);
    246      1.48    itojun 			mob_h.hcrc = gre_in_cksum((u_int16_t *)&mob_h, msiz);
    247       1.3       hwr 
    248       1.3       hwr 			if ((m->m_data - msiz) < m->m_pktdat) {
    249       1.3       hwr 				/* need new mbuf */
    250       1.3       hwr 				MGETHDR(m0, M_DONTWAIT, MT_HEADER);
    251       1.8  explorer 				if (m0 == NULL) {
    252       1.3       hwr 					IF_DROP(&ifp->if_snd);
    253       1.3       hwr 					m_freem(m);
    254      1.38    itojun 					error = ENOBUFS;
    255      1.38    itojun 					goto end;
    256       1.3       hwr 				}
    257       1.8  explorer 				m0->m_next = m;
    258       1.3       hwr 				m->m_data += sizeof(struct ip);
    259       1.3       hwr 				m->m_len -= sizeof(struct ip);
    260       1.8  explorer 				m0->m_pkthdr.len = m->m_pkthdr.len + msiz;
    261       1.3       hwr 				m0->m_len = msiz + sizeof(struct ip);
    262       1.3       hwr 				m0->m_data += max_linkhdr;
    263      1.41    itojun 				memcpy(mtod(m0, caddr_t), (caddr_t)ip,
    264       1.8  explorer 				       sizeof(struct ip));
    265       1.8  explorer 				m = m0;
    266      1.20    itojun 			} else {  /* we have some space left in the old one */
    267       1.8  explorer 				m->m_data -= msiz;
    268       1.8  explorer 				m->m_len += msiz;
    269       1.8  explorer 				m->m_pkthdr.len += msiz;
    270      1.41    itojun 				memmove(mtod(m, caddr_t), ip,
    271       1.8  explorer 					sizeof(struct ip));
    272       1.3       hwr 			}
    273      1.41    itojun 			ip = mtod(m, struct ip *);
    274      1.41    itojun 			memcpy((caddr_t)(ip + 1), &mob_h, (unsigned)msiz);
    275      1.42    itojun 			ip->ip_len = htons(ntohs(ip->ip_len) + msiz);
    276       1.3       hwr 		} else {  /* AF_INET */
    277       1.3       hwr 			IF_DROP(&ifp->if_snd);
    278       1.3       hwr 			m_freem(m);
    279      1.38    itojun 			error = EINVAL;
    280      1.38    itojun 			goto end;
    281       1.3       hwr 		}
    282       1.1       hwr 	} else if (sc->g_proto == IPPROTO_GRE) {
    283      1.20    itojun 		switch (dst->sa_family) {
    284       1.1       hwr 		case AF_INET:
    285      1.41    itojun 			ip = mtod(m, struct ip *);
    286       1.8  explorer 			etype = ETHERTYPE_IP;
    287       1.1       hwr 			break;
    288       1.1       hwr #ifdef NETATALK
    289       1.1       hwr 		case AF_APPLETALK:
    290       1.8  explorer 			etype = ETHERTYPE_ATALK;
    291       1.1       hwr 			break;
    292       1.1       hwr #endif
    293       1.1       hwr #ifdef NS
    294       1.1       hwr 		case AF_NS:
    295       1.8  explorer 			etype = ETHERTYPE_NS;
    296       1.1       hwr 			break;
    297       1.1       hwr #endif
    298       1.1       hwr 		default:
    299       1.1       hwr 			IF_DROP(&ifp->if_snd);
    300       1.1       hwr 			m_freem(m);
    301      1.38    itojun 			error = EAFNOSUPPORT;
    302      1.38    itojun 			goto end;
    303       1.1       hwr 		}
    304       1.8  explorer 		M_PREPEND(m, sizeof(struct greip), M_DONTWAIT);
    305       1.1       hwr 	} else {
    306       1.1       hwr 		IF_DROP(&ifp->if_snd);
    307       1.1       hwr 		m_freem(m);
    308      1.38    itojun 		error = EINVAL;
    309      1.38    itojun 		goto end;
    310       1.1       hwr 	}
    311       1.1       hwr 
    312      1.38    itojun 	if (m == NULL) {	/* impossible */
    313       1.1       hwr 		IF_DROP(&ifp->if_snd);
    314      1.38    itojun 		error = ENOBUFS;
    315      1.38    itojun 		goto end;
    316       1.1       hwr 	}
    317       1.1       hwr 
    318       1.8  explorer 	gh = mtod(m, struct greip *);
    319       1.8  explorer 	if (sc->g_proto == IPPROTO_GRE) {
    320       1.1       hwr 		/* we don't have any GRE flags for now */
    321       1.1       hwr 
    322       1.8  explorer 		memset((void *)&gh->gi_g, 0, sizeof(struct gre_h));
    323       1.8  explorer 		gh->gi_ptype = htons(etype);
    324       1.1       hwr 	}
    325       1.1       hwr 
    326       1.1       hwr 	gh->gi_pr = sc->g_proto;
    327       1.3       hwr 	if (sc->g_proto != IPPROTO_MOBILE) {
    328       1.3       hwr 		gh->gi_src = sc->g_src;
    329       1.3       hwr 		gh->gi_dst = sc->g_dst;
    330      1.20    itojun 		((struct ip*)gh)->ip_hl = (sizeof(struct ip)) >> 2;
    331      1.26    martin 		((struct ip*)gh)->ip_ttl = ip_gre_ttl;
    332      1.41    itojun 		((struct ip*)gh)->ip_tos = ip->ip_tos;
    333      1.49    itojun 		gh->gi_len = htons(m->m_pkthdr.len);
    334       1.3       hwr 	}
    335       1.1       hwr 
    336       1.1       hwr 	ifp->if_opackets++;
    337       1.8  explorer 	ifp->if_obytes += m->m_pkthdr.len;
    338       1.1       hwr 	/* send it off */
    339      1.46  jonathan 	error = ip_output(m, NULL, &sc->route, 0,
    340      1.47    itojun 	    (struct ip_moptions *)NULL, (struct socket *)NULL);
    341      1.38    itojun   end:
    342       1.8  explorer 	if (error)
    343       1.1       hwr 		ifp->if_oerrors++;
    344       1.8  explorer 	return (error);
    345       1.1       hwr }
    346       1.1       hwr 
    347       1.1       hwr int
    348       1.8  explorer gre_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
    349       1.1       hwr {
    350      1.13    martin 	struct proc *p = curproc;	/* XXX */
    351       1.8  explorer 	struct ifreq *ifr = (struct ifreq *)data;
    352      1.28    itojun 	struct if_laddrreq *lifr = (struct if_laddrreq *)data;
    353       1.8  explorer 	struct gre_softc *sc = ifp->if_softc;
    354       1.1       hwr 	int s;
    355       1.1       hwr 	struct sockaddr_in si;
    356       1.8  explorer 	struct sockaddr *sa = NULL;
    357       1.1       hwr 	int error;
    358       1.1       hwr 
    359       1.8  explorer 	error = 0;
    360       1.1       hwr 
    361      1.18   thorpej 	s = splnet();
    362      1.20    itojun 	switch (cmd) {
    363      1.20    itojun 	case SIOCSIFADDR:
    364      1.36    itojun 		ifp->if_flags |= IFF_UP;
    365      1.36    itojun 		break;
    366      1.20    itojun 	case SIOCSIFDSTADDR:
    367       1.1       hwr 		break;
    368       1.1       hwr 	case SIOCSIFFLAGS:
    369      1.13    martin 		if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
    370      1.13    martin 			break;
    371      1.35    itojun 		if ((ifr->ifr_flags & IFF_LINK0) != 0)
    372      1.35    itojun 			sc->g_proto = IPPROTO_GRE;
    373      1.35    itojun 		else
    374      1.35    itojun 			sc->g_proto = IPPROTO_MOBILE;
    375       1.1       hwr 		break;
    376      1.20    itojun 	case SIOCSIFMTU:
    377      1.13    martin 		if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
    378      1.13    martin 			break;
    379      1.27    martin 		if (ifr->ifr_mtu < 576) {
    380       1.1       hwr 			error = EINVAL;
    381       1.1       hwr 			break;
    382       1.1       hwr 		}
    383       1.1       hwr 		ifp->if_mtu = ifr->ifr_mtu;
    384       1.1       hwr 		break;
    385       1.1       hwr 	case SIOCGIFMTU:
    386       1.1       hwr 		ifr->ifr_mtu = sc->sc_if.if_mtu;
    387       1.1       hwr 		break;
    388       1.1       hwr 	case SIOCADDMULTI:
    389       1.1       hwr 	case SIOCDELMULTI:
    390      1.13    martin 		if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
    391      1.13    martin 			break;
    392       1.8  explorer 		if (ifr == 0) {
    393       1.1       hwr 			error = EAFNOSUPPORT;
    394       1.1       hwr 			break;
    395       1.1       hwr 		}
    396       1.8  explorer 		switch (ifr->ifr_addr.sa_family) {
    397       1.1       hwr #ifdef INET
    398       1.1       hwr 		case AF_INET:
    399       1.1       hwr 			break;
    400       1.1       hwr #endif
    401       1.1       hwr 		default:
    402       1.1       hwr 			error = EAFNOSUPPORT;
    403       1.1       hwr 			break;
    404       1.1       hwr 		}
    405       1.1       hwr 		break;
    406       1.1       hwr 	case GRESPROTO:
    407      1.13    martin 		if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
    408      1.13    martin 			break;
    409       1.1       hwr 		sc->g_proto = ifr->ifr_flags;
    410       1.1       hwr 		switch (sc->g_proto) {
    411      1.40    itojun 		case IPPROTO_GRE:
    412       1.3       hwr 			ifp->if_flags |= IFF_LINK0;
    413       1.1       hwr 			break;
    414      1.40    itojun 		case IPPROTO_MOBILE:
    415      1.35    itojun 			ifp->if_flags &= ~IFF_LINK0;
    416       1.1       hwr 			break;
    417       1.1       hwr 		default:
    418      1.40    itojun 			error = EPROTONOSUPPORT;
    419      1.35    itojun 			break;
    420       1.1       hwr 		}
    421       1.1       hwr 		break;
    422       1.1       hwr 	case GREGPROTO:
    423       1.1       hwr 		ifr->ifr_flags = sc->g_proto;
    424       1.1       hwr 		break;
    425       1.1       hwr 	case GRESADDRS:
    426       1.1       hwr 	case GRESADDRD:
    427      1.13    martin 		if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
    428      1.13    martin 			break;
    429       1.1       hwr 		/*
    430      1.20    itojun 		 * set tunnel endpoints, compute a less specific route
    431      1.20    itojun 		 * to the remote end and mark if as up
    432      1.20    itojun 		 */
    433       1.1       hwr 		sa = &ifr->ifr_addr;
    434      1.30    itojun 		if (cmd == GRESADDRS)
    435       1.1       hwr 			sc->g_src = (satosin(sa))->sin_addr;
    436      1.30    itojun 		if (cmd == GRESADDRD)
    437       1.1       hwr 			sc->g_dst = (satosin(sa))->sin_addr;
    438      1.30    itojun 	recompute:
    439       1.1       hwr 		if ((sc->g_src.s_addr != INADDR_ANY) &&
    440       1.1       hwr 		    (sc->g_dst.s_addr != INADDR_ANY)) {
    441       1.1       hwr 			if (sc->route.ro_rt != 0) /* free old route */
    442       1.1       hwr 				RTFREE(sc->route.ro_rt);
    443      1.25    martin 			if (gre_compute_route(sc) == 0)
    444      1.39    itojun 				ifp->if_flags |= IFF_RUNNING;
    445      1.39    itojun 			else
    446      1.39    itojun 				ifp->if_flags &= ~IFF_RUNNING;
    447       1.1       hwr 		}
    448       1.1       hwr 		break;
    449       1.1       hwr 	case GREGADDRS:
    450      1.33    itojun 		memset(&si, 0, sizeof(si));
    451      1.28    itojun 		si.sin_family = AF_INET;
    452      1.28    itojun 		si.sin_len = sizeof(struct sockaddr_in);
    453       1.1       hwr 		si.sin_addr.s_addr = sc->g_src.s_addr;
    454       1.8  explorer 		sa = sintosa(&si);
    455       1.1       hwr 		ifr->ifr_addr = *sa;
    456       1.1       hwr 		break;
    457       1.1       hwr 	case GREGADDRD:
    458      1.33    itojun 		memset(&si, 0, sizeof(si));
    459      1.28    itojun 		si.sin_family = AF_INET;
    460      1.28    itojun 		si.sin_len = sizeof(struct sockaddr_in);
    461       1.1       hwr 		si.sin_addr.s_addr = sc->g_dst.s_addr;
    462       1.8  explorer 		sa = sintosa(&si);
    463       1.1       hwr 		ifr->ifr_addr = *sa;
    464      1.28    itojun 		break;
    465      1.28    itojun 	case SIOCSLIFPHYADDR:
    466      1.28    itojun 		if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
    467      1.28    itojun 			break;
    468      1.28    itojun 		if (lifr->addr.ss_family != AF_INET ||
    469      1.31    itojun 		    lifr->dstaddr.ss_family != AF_INET) {
    470      1.31    itojun 			error = EAFNOSUPPORT;
    471      1.31    itojun 			break;
    472      1.31    itojun 		}
    473      1.28    itojun 		if (lifr->addr.ss_len != sizeof(si) ||
    474      1.31    itojun 		    lifr->dstaddr.ss_len != sizeof(si)) {
    475      1.31    itojun 			error = EINVAL;
    476      1.31    itojun 			break;
    477      1.31    itojun 		}
    478      1.28    itojun 		sc->g_src = (satosin((struct sockadrr *)&lifr->addr))->sin_addr;
    479      1.28    itojun 		sc->g_dst =
    480      1.28    itojun 		    (satosin((struct sockadrr *)&lifr->dstaddr))->sin_addr;
    481      1.30    itojun 		goto recompute;
    482      1.28    itojun 	case SIOCDIFPHYADDR:
    483      1.28    itojun 		if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
    484      1.28    itojun 			break;
    485      1.28    itojun 		sc->g_src.s_addr = INADDR_ANY;
    486      1.28    itojun 		sc->g_dst.s_addr = INADDR_ANY;
    487      1.28    itojun 		break;
    488      1.28    itojun 	case SIOCGLIFPHYADDR:
    489      1.28    itojun 		if (sc->g_src.s_addr == INADDR_ANY ||
    490      1.28    itojun 		    sc->g_dst.s_addr == INADDR_ANY) {
    491      1.28    itojun 			error = EADDRNOTAVAIL;
    492      1.28    itojun 			break;
    493      1.28    itojun 		}
    494      1.33    itojun 		memset(&si, 0, sizeof(si));
    495      1.28    itojun 		si.sin_family = AF_INET;
    496      1.28    itojun 		si.sin_len = sizeof(struct sockaddr_in);
    497      1.28    itojun 		si.sin_addr.s_addr = sc->g_src.s_addr;
    498      1.33    itojun 		memcpy(&lifr->addr, &si, sizeof(si));
    499      1.28    itojun 		si.sin_addr.s_addr = sc->g_dst.s_addr;
    500      1.33    itojun 		memcpy(&lifr->dstaddr, &si, sizeof(si));
    501       1.1       hwr 		break;
    502       1.1       hwr 	default:
    503       1.1       hwr 		error = EINVAL;
    504      1.31    itojun 		break;
    505       1.1       hwr 	}
    506       1.1       hwr 
    507       1.1       hwr 	splx(s);
    508       1.8  explorer 	return (error);
    509       1.1       hwr }
    510       1.1       hwr 
    511      1.20    itojun /*
    512       1.1       hwr  * computes a route to our destination that is not the one
    513       1.1       hwr  * which would be taken by ip_output(), as this one will loop back to
    514       1.1       hwr  * us. If the interface is p2p as  a--->b, then a routing entry exists
    515       1.1       hwr  * If we now send a packet to b (e.g. ping b), this will come down here
    516      1.43       wiz  * gets src=a, dst=b tacked on and would from ip_output() sent back to
    517       1.1       hwr  * if_gre.
    518       1.1       hwr  * Goal here is to compute a route to b that is less specific than
    519       1.1       hwr  * a-->b. We know that this one exists as in normal operation we have
    520       1.1       hwr  * at least a default route which matches.
    521       1.1       hwr  */
    522      1.25    martin int
    523       1.8  explorer gre_compute_route(struct gre_softc *sc)
    524       1.1       hwr {
    525       1.1       hwr 	struct route *ro;
    526       1.8  explorer 	u_int32_t a, b, c;
    527       1.1       hwr 
    528       1.8  explorer 	ro = &sc->route;
    529      1.20    itojun 
    530       1.8  explorer 	memset(ro, 0, sizeof(struct route));
    531       1.8  explorer 	((struct sockaddr_in *)&ro->ro_dst)->sin_addr = sc->g_dst;
    532       1.8  explorer 	ro->ro_dst.sa_family = AF_INET;
    533       1.8  explorer 	ro->ro_dst.sa_len = sizeof(ro->ro_dst);
    534       1.8  explorer 
    535       1.1       hwr 	/*
    536       1.1       hwr 	 * toggle last bit, so our interface is not found, but a less
    537      1.20    itojun 	 * specific route. I'd rather like to specify a shorter mask,
    538      1.20    itojun 	 * but this is not possible. Should work though. XXX
    539       1.1       hwr 	 * there is a simpler way ...
    540      1.20    itojun 	 */
    541       1.8  explorer 	if ((sc->sc_if.if_flags & IFF_LINK1) == 0) {
    542       1.8  explorer 		a = ntohl(sc->g_dst.s_addr);
    543       1.8  explorer 		b = a & 0x01;
    544       1.8  explorer 		c = a & 0xfffffffe;
    545       1.8  explorer 		b = b ^ 0x01;
    546       1.8  explorer 		a = b | c;
    547       1.8  explorer 		((struct sockaddr_in *)&ro->ro_dst)->sin_addr.s_addr
    548      1.20    itojun 		    = htonl(a);
    549       1.8  explorer 	}
    550       1.1       hwr 
    551       1.1       hwr #ifdef DIAGNOSTIC
    552      1.45     grant 	printf("%s: searching for a route to %s", sc->sc_if.if_xname,
    553      1.19    itojun 	    inet_ntoa(((struct sockaddr_in *)&ro->ro_dst)->sin_addr));
    554       1.1       hwr #endif
    555       1.1       hwr 
    556       1.1       hwr 	rtalloc(ro);
    557       1.1       hwr 
    558       1.1       hwr 	/*
    559      1.25    martin 	 * check if this returned a route at all and this route is no
    560      1.25    martin 	 * recursion to ourself
    561      1.25    martin 	 */
    562      1.25    martin 	if (ro->ro_rt == NULL || ro->ro_rt->rt_ifp->if_softc == sc) {
    563      1.25    martin #ifdef DIAGNOSTIC
    564      1.25    martin 		if (ro->ro_rt == NULL)
    565      1.25    martin 			printf(" - no route found!\n");
    566      1.25    martin 		else
    567      1.25    martin 			printf(" - route loops back to ourself!\n");
    568      1.25    martin #endif
    569      1.25    martin 		return EADDRNOTAVAIL;
    570      1.25    martin 	}
    571      1.25    martin 
    572      1.25    martin 	/*
    573      1.20    itojun 	 * now change it back - else ip_output will just drop
    574      1.20    itojun 	 * the route and search one to this interface ...
    575      1.20    itojun 	 */
    576       1.8  explorer 	if ((sc->sc_if.if_flags & IFF_LINK1) == 0)
    577       1.8  explorer 		((struct sockaddr_in *)&ro->ro_dst)->sin_addr = sc->g_dst;
    578       1.1       hwr 
    579       1.1       hwr #ifdef DIAGNOSTIC
    580      1.19    itojun 	printf(", choosing %s with gateway %s", ro->ro_rt->rt_ifp->if_xname,
    581      1.19    itojun 	    inet_ntoa(((struct sockaddr_in *)(ro->ro_rt->rt_gateway))->sin_addr));
    582       1.8  explorer 	printf("\n");
    583       1.1       hwr #endif
    584      1.25    martin 
    585      1.25    martin 	return 0;
    586       1.1       hwr }
    587       1.1       hwr 
    588       1.3       hwr /*
    589      1.20    itojun  * do a checksum of a buffer - much like in_cksum, which operates on
    590      1.20    itojun  * mbufs.
    591       1.3       hwr  */
    592      1.48    itojun u_int16_t
    593      1.48    itojun gre_in_cksum(u_int16_t *p, u_int len)
    594       1.3       hwr {
    595      1.48    itojun 	u_int32_t sum = 0;
    596       1.3       hwr 	int nwords = len >> 1;
    597      1.20    itojun 
    598       1.3       hwr 	while (nwords-- != 0)
    599       1.3       hwr 		sum += *p++;
    600      1.20    itojun 
    601      1.20    itojun 	if (len & 1) {
    602      1.20    itojun 		union {
    603      1.20    itojun 			u_short w;
    604      1.20    itojun 			u_char c[2];
    605      1.20    itojun 		} u;
    606      1.20    itojun 		u.c[0] = *(u_char *)p;
    607      1.20    itojun 		u.c[1] = 0;
    608      1.20    itojun 		sum += u.w;
    609      1.20    itojun 	}
    610      1.20    itojun 
    611      1.20    itojun 	/* end-around-carry */
    612      1.20    itojun 	sum = (sum >> 16) + (sum & 0xffff);
    613      1.20    itojun 	sum += (sum >> 16);
    614      1.20    itojun 	return (~sum);
    615       1.3       hwr }
    616