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if_faith.c revision 1.47
      1 /*	$NetBSD: if_faith.c,v 1.47 2010/04/05 07:22:23 joerg 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 1.47 2010/04/05 07:22:23 joerg 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 
     83 #include <net/net_osdep.h>
     84 
     85 static int	faithioctl(struct ifnet *, u_long, void *);
     86 static int	faithoutput(struct ifnet *, struct mbuf *,
     87 		            const struct sockaddr *, struct rtentry *);
     88 static void	faithrtrequest(int, struct rtentry *,
     89 		               const 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 = if_alloc(IFT_FAITH);
    115 
    116 	if_initname(ifp, ifc->ifc_name, unit);
    117 
    118 	ifp->if_mtu = FAITHMTU;
    119 	/* Change to BROADCAST experimentaly to announce its prefix. */
    120 	ifp->if_flags = /* IFF_LOOPBACK */ IFF_BROADCAST | IFF_MULTICAST;
    121 	ifp->if_ioctl = faithioctl;
    122 	ifp->if_output = faithoutput;
    123 	ifp->if_type = IFT_FAITH;
    124 	ifp->if_hdrlen = 0;
    125 	ifp->if_addrlen = 0;
    126 	ifp->if_dlt = DLT_NULL;
    127 	if_attach(ifp);
    128 	if_alloc_sadl(ifp);
    129 	bpf_attach(ifp, DLT_NULL, sizeof(u_int));
    130 	return (0);
    131 }
    132 
    133 int
    134 faith_clone_destroy(struct ifnet *ifp)
    135 {
    136 
    137 	bpf_detach(ifp);
    138 	if_detach(ifp);
    139 	free(ifp, M_DEVBUF);
    140 
    141 	return (0);
    142 }
    143 
    144 static int
    145 faithoutput(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
    146     struct rtentry *rt)
    147 {
    148 	int s, isr;
    149 	uint32_t af;
    150 	struct ifqueue *ifq = 0;
    151 
    152 	if ((m->m_flags & M_PKTHDR) == 0)
    153 		panic("faithoutput no HDR");
    154 	af = dst->sa_family;
    155 	/* BPF write needs to be handled specially */
    156 	if (af == AF_UNSPEC) {
    157 		af = *(mtod(m, int *));
    158 		m_adj(m, sizeof(int));
    159 	}
    160 
    161 	bpf_mtap_af(ifp, af, m);
    162 
    163 	if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
    164 		m_freem(m);
    165 		return (rt->rt_flags & RTF_BLACKHOLE ? 0 :
    166 		        rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
    167 	}
    168 	ifp->if_opackets++;
    169 	ifp->if_obytes += m->m_pkthdr.len;
    170 	switch (af) {
    171 #ifdef INET
    172 	case AF_INET:
    173 		ifq = &ipintrq;
    174 		isr = NETISR_IP;
    175 		break;
    176 #endif
    177 #ifdef INET6
    178 	case AF_INET6:
    179 		ifq = &ip6intrq;
    180 		isr = NETISR_IPV6;
    181 		break;
    182 #endif
    183 	default:
    184 		m_freem(m);
    185 		return EAFNOSUPPORT;
    186 	}
    187 
    188 	/* XXX do we need more sanity checks? */
    189 
    190 	m->m_pkthdr.rcvif = ifp;
    191 	s = splnet();
    192 	if (IF_QFULL(ifq)) {
    193 		IF_DROP(ifq);
    194 		m_freem(m);
    195 		splx(s);
    196 		return (ENOBUFS);
    197 	}
    198 	IF_ENQUEUE(ifq, m);
    199 	schednetisr(isr);
    200 	ifp->if_ipackets++;
    201 	ifp->if_ibytes += m->m_pkthdr.len;
    202 	splx(s);
    203 	return (0);
    204 }
    205 
    206 /* ARGSUSED */
    207 static void
    208 faithrtrequest(int cmd, struct rtentry *rt,
    209     const struct rt_addrinfo *info)
    210 {
    211 	if (rt)
    212 		rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu; /* for ISO */
    213 }
    214 
    215 /*
    216  * Process an ioctl request.
    217  */
    218 /* ARGSUSED */
    219 static int
    220 faithioctl(struct ifnet *ifp, u_long cmd, void *data)
    221 {
    222 	struct ifaddr *ifa;
    223 	struct ifreq *ifr = (struct ifreq *)data;
    224 	int error = 0;
    225 
    226 	switch (cmd) {
    227 
    228 	case SIOCINITIFADDR:
    229 		ifp->if_flags |= IFF_UP | IFF_RUNNING;
    230 		ifa = (struct ifaddr *)data;
    231 		ifa->ifa_rtrequest = faithrtrequest;
    232 		/*
    233 		 * Everything else is done at a higher level.
    234 		 */
    235 		break;
    236 
    237 	case SIOCADDMULTI:
    238 	case SIOCDELMULTI:
    239 		if (ifr == 0) {
    240 			error = EAFNOSUPPORT;		/* XXX */
    241 			break;
    242 		}
    243 		switch (ifr->ifr_addr.sa_family) {
    244 #ifdef INET
    245 		case AF_INET:
    246 			break;
    247 #endif
    248 #ifdef INET6
    249 		case AF_INET6:
    250 			break;
    251 #endif
    252 
    253 		default:
    254 			error = EAFNOSUPPORT;
    255 			break;
    256 		}
    257 		break;
    258 
    259 	default:
    260 		if ((error = ifioctl_common(ifp, cmd, data)) == ENETRESET)
    261 			error = 0;
    262 		break;
    263 	}
    264 	return (error);
    265 }
    266 
    267 #ifdef INET6
    268 /*
    269  * XXX could be slow
    270  * XXX could be layer violation to call sys/net from sys/netinet6
    271  */
    272 int
    273 faithprefix(struct in6_addr *in6)
    274 {
    275 	struct rtentry *rt;
    276 	struct sockaddr_in6 sin6;
    277 	int ret;
    278 
    279 	if (ip6_keepfaith == 0)
    280 		return 0;
    281 
    282 	memset(&sin6, 0, sizeof(sin6));
    283 	sin6.sin6_family = AF_INET6;
    284 	sin6.sin6_len = sizeof(struct sockaddr_in6);
    285 	sin6.sin6_addr = *in6;
    286 	rt = rtalloc1((struct sockaddr *)&sin6, 0);
    287 	if (rt && rt->rt_ifp && rt->rt_ifp->if_type == IFT_FAITH &&
    288 	    (rt->rt_ifp->if_flags & IFF_UP) != 0)
    289 		ret = 1;
    290 	else
    291 		ret = 0;
    292 	if (rt)
    293 		RTFREE(rt);
    294 	return ret;
    295 }
    296 #endif
    297