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if_faith.c revision 1.41
      1 /*	$NetBSD: if_faith.c,v 1.41 2008/02/07 01:22:00 dyoung Exp $	*/
      2 /*	$KAME: if_faith.c,v 1.21 2001/02/20 07:59:26 itojun Exp $	*/
      3 
      4 /*
      5  * Copyright (c) 1982, 1986, 1993
      6  *	The Regents of the University of California.  All rights reserved.
      7  *
      8  * Redistribution and use in source and binary forms, with or without
      9  * modification, are permitted provided that the following conditions
     10  * are met:
     11  * 1. Redistributions of source code must retain the above copyright
     12  *    notice, this list of conditions and the following disclaimer.
     13  * 2. Redistributions in binary form must reproduce the above copyright
     14  *    notice, this list of conditions and the following disclaimer in the
     15  *    documentation and/or other materials provided with the distribution.
     16  * 3. Neither the name of the University nor the names of its contributors
     17  *    may be used to endorse or promote products derived from this software
     18  *    without specific prior written permission.
     19  *
     20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     30  * SUCH DAMAGE.
     31  */
     32 /*
     33  * derived from
     34  *	@(#)if_loop.c	8.1 (Berkeley) 6/10/93
     35  * Id: if_loop.c,v 1.22 1996/06/19 16:24:10 wollman Exp
     36  */
     37 
     38 /*
     39  * IPv6-to-IPv4 TCP relay capturing interface
     40  */
     41 
     42 #include <sys/cdefs.h>
     43 __KERNEL_RCSID(0, "$NetBSD: if_faith.c,v 1.41 2008/02/07 01:22:00 dyoung Exp $");
     44 
     45 #include "opt_inet.h"
     46 
     47 #include <sys/param.h>
     48 #include <sys/systm.h>
     49 #include <sys/kernel.h>
     50 #include <sys/mbuf.h>
     51 #include <sys/socket.h>
     52 #include <sys/errno.h>
     53 #include <sys/ioctl.h>
     54 #include <sys/time.h>
     55 #include <sys/queue.h>
     56 
     57 #include <sys/cpu.h>
     58 
     59 #include <net/if.h>
     60 #include <net/if_types.h>
     61 #include <net/netisr.h>
     62 #include <net/route.h>
     63 #include <net/bpf.h>
     64 #include <net/if_faith.h>
     65 
     66 #ifdef	INET
     67 #include <netinet/in.h>
     68 #include <netinet/in_systm.h>
     69 #include <netinet/in_var.h>
     70 #include <netinet/ip.h>
     71 #endif
     72 
     73 #ifdef INET6
     74 #ifndef INET
     75 #include <netinet/in.h>
     76 #endif
     77 #include <netinet6/in6_var.h>
     78 #include <netinet/ip6.h>
     79 #include <netinet6/ip6_var.h>
     80 #endif
     81 
     82 #include "bpfilter.h"
     83 
     84 #include <net/net_osdep.h>
     85 
     86 static int	faithioctl(struct ifnet *, u_long, void *);
     87 static int	faithoutput(struct ifnet *, struct mbuf *,
     88 		            const struct sockaddr *, struct rtentry *);
     89 static void	faithrtrequest(int, struct rtentry *, struct rt_addrinfo *);
     90 
     91 void	faithattach(int);
     92 
     93 static int	faith_clone_create(struct if_clone *, int);
     94 static int	faith_clone_destroy(struct ifnet *);
     95 
     96 static struct if_clone faith_cloner =
     97     IF_CLONE_INITIALIZER("faith", faith_clone_create, faith_clone_destroy);
     98 
     99 #define	FAITHMTU	1500
    100 
    101 /* ARGSUSED */
    102 void
    103 faithattach(int count)
    104 {
    105 
    106 	if_clone_attach(&faith_cloner);
    107 }
    108 
    109 static int
    110 faith_clone_create(struct if_clone *ifc, int unit)
    111 {
    112 	struct ifnet *ifp;
    113 
    114 	ifp = malloc(sizeof(*ifp), M_DEVBUF, M_WAITOK | M_ZERO);
    115 
    116 	snprintf(ifp->if_xname, sizeof(ifp->if_xname), "%s%d",
    117 	    ifc->ifc_name, unit);
    118 
    119 	ifp->if_mtu = FAITHMTU;
    120 	/* Change to BROADCAST experimentaly to announce its prefix. */
    121 	ifp->if_flags = /* IFF_LOOPBACK */ IFF_BROADCAST | IFF_MULTICAST;
    122 	ifp->if_ioctl = faithioctl;
    123 	ifp->if_output = faithoutput;
    124 	ifp->if_type = IFT_FAITH;
    125 	ifp->if_hdrlen = 0;
    126 	ifp->if_addrlen = 0;
    127 	ifp->if_dlt = DLT_NULL;
    128 	if_attach(ifp);
    129 	if_alloc_sadl(ifp);
    130 #if NBPFILTER > 0
    131 	bpfattach(ifp, DLT_NULL, sizeof(u_int));
    132 #endif
    133 	return (0);
    134 }
    135 
    136 int
    137 faith_clone_destroy(struct ifnet *ifp)
    138 {
    139 
    140 #if NBPFILTER > 0
    141 	bpfdetach(ifp);
    142 #endif
    143 	if_detach(ifp);
    144 	free(ifp, M_DEVBUF);
    145 
    146 	return (0);
    147 }
    148 
    149 static int
    150 faithoutput(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
    151     struct rtentry *rt)
    152 {
    153 	int s, isr;
    154 	uint32_t af;
    155 	struct ifqueue *ifq = 0;
    156 
    157 	if ((m->m_flags & M_PKTHDR) == 0)
    158 		panic("faithoutput no HDR");
    159 	af = dst->sa_family;
    160 #if NBPFILTER > 0
    161 	/* BPF write needs to be handled specially */
    162 	if (af == AF_UNSPEC) {
    163 		af = *(mtod(m, int *));
    164 		m_adj(m, sizeof(int));
    165 	}
    166 
    167 	if (ifp->if_bpf)
    168 		bpf_mtap_af(ifp->if_bpf, af, m);
    169 #endif
    170 
    171 	if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
    172 		m_freem(m);
    173 		return (rt->rt_flags & RTF_BLACKHOLE ? 0 :
    174 		        rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
    175 	}
    176 	ifp->if_opackets++;
    177 	ifp->if_obytes += m->m_pkthdr.len;
    178 	switch (af) {
    179 #ifdef INET
    180 	case AF_INET:
    181 		ifq = &ipintrq;
    182 		isr = NETISR_IP;
    183 		break;
    184 #endif
    185 #ifdef INET6
    186 	case AF_INET6:
    187 		ifq = &ip6intrq;
    188 		isr = NETISR_IPV6;
    189 		break;
    190 #endif
    191 	default:
    192 		m_freem(m);
    193 		return EAFNOSUPPORT;
    194 	}
    195 
    196 	/* XXX do we need more sanity checks? */
    197 
    198 	m->m_pkthdr.rcvif = ifp;
    199 	s = splnet();
    200 	if (IF_QFULL(ifq)) {
    201 		IF_DROP(ifq);
    202 		m_freem(m);
    203 		splx(s);
    204 		return (ENOBUFS);
    205 	}
    206 	IF_ENQUEUE(ifq, m);
    207 	schednetisr(isr);
    208 	ifp->if_ipackets++;
    209 	ifp->if_ibytes += m->m_pkthdr.len;
    210 	splx(s);
    211 	return (0);
    212 }
    213 
    214 /* ARGSUSED */
    215 static void
    216 faithrtrequest(int cmd, struct rtentry *rt,
    217     struct rt_addrinfo *info)
    218 {
    219 	if (rt)
    220 		rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu; /* for ISO */
    221 }
    222 
    223 /*
    224  * Process an ioctl request.
    225  */
    226 /* ARGSUSED */
    227 static int
    228 faithioctl(struct ifnet *ifp, u_long cmd, void *data)
    229 {
    230 	struct ifaddr *ifa;
    231 	struct ifreq *ifr = (struct ifreq *)data;
    232 	int error = 0;
    233 
    234 	switch (cmd) {
    235 
    236 	case SIOCSIFADDR:
    237 		ifp->if_flags |= IFF_UP | IFF_RUNNING;
    238 		ifa = (struct ifaddr *)data;
    239 		ifa->ifa_rtrequest = faithrtrequest;
    240 		/*
    241 		 * Everything else is done at a higher level.
    242 		 */
    243 		break;
    244 
    245 	case SIOCADDMULTI:
    246 	case SIOCDELMULTI:
    247 		if (ifr == 0) {
    248 			error = EAFNOSUPPORT;		/* XXX */
    249 			break;
    250 		}
    251 		switch (ifr->ifr_addr.sa_family) {
    252 #ifdef INET
    253 		case AF_INET:
    254 			break;
    255 #endif
    256 #ifdef INET6
    257 		case AF_INET6:
    258 			break;
    259 #endif
    260 
    261 		default:
    262 			error = EAFNOSUPPORT;
    263 			break;
    264 		}
    265 		break;
    266 
    267 #ifdef SIOCSIFMTU
    268 	case SIOCSIFMTU:
    269 		if ((error = ifioctl_common(ifp, cmd, data)) == ENETRESET)
    270 			error = 0;
    271 		break;
    272 #endif
    273 
    274 	case SIOCSIFFLAGS:
    275 		break;
    276 
    277 	default:
    278 		error = EINVAL;
    279 	}
    280 	return (error);
    281 }
    282 
    283 #ifdef INET6
    284 /*
    285  * XXX could be slow
    286  * XXX could be layer violation to call sys/net from sys/netinet6
    287  */
    288 int
    289 faithprefix(struct in6_addr *in6)
    290 {
    291 	struct rtentry *rt;
    292 	struct sockaddr_in6 sin6;
    293 	int ret;
    294 
    295 	if (ip6_keepfaith == 0)
    296 		return 0;
    297 
    298 	memset(&sin6, 0, sizeof(sin6));
    299 	sin6.sin6_family = AF_INET6;
    300 	sin6.sin6_len = sizeof(struct sockaddr_in6);
    301 	sin6.sin6_addr = *in6;
    302 	rt = rtalloc1((struct sockaddr *)&sin6, 0);
    303 	if (rt && rt->rt_ifp && rt->rt_ifp->if_type == IFT_FAITH &&
    304 	    (rt->rt_ifp->if_flags & IFF_UP) != 0)
    305 		ret = 1;
    306 	else
    307 		ret = 0;
    308 	if (rt)
    309 		RTFREE(rt);
    310 	return ret;
    311 }
    312 #endif
    313