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if_faith.c revision 1.54 
      1 /*	$NetBSD: if_faith.c,v 1.54 2016/08/07 17:38:33 christos 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 1.54 2016/08/07 17:38:33 christos Exp $");
     44 
     45 #ifdef _KERNEL_OPT
     46 #include "opt_inet.h"
     47 #endif
     48 
     49 #include <sys/param.h>
     50 #include <sys/systm.h>
     51 #include <sys/kernel.h>
     52 #include <sys/mbuf.h>
     53 #include <sys/socket.h>
     54 #include <sys/errno.h>
     55 #include <sys/ioctl.h>
     56 #include <sys/time.h>
     57 #include <sys/queue.h>
     58 #include <sys/device.h>
     59 #include <sys/module.h>
     60 #include <sys/atomic.h>
     61 
     62 #include <sys/cpu.h>
     63 
     64 #include <net/if.h>
     65 #include <net/if_types.h>
     66 #include <net/netisr.h>
     67 #include <net/route.h>
     68 #include <net/bpf.h>
     69 #include <net/if_faith.h>
     70 
     71 #ifdef	INET
     72 #include <netinet/in.h>
     73 #include <netinet/in_systm.h>
     74 #include <netinet/in_var.h>
     75 #include <netinet/ip.h>
     76 #endif
     77 
     78 #ifdef INET6
     79 #ifndef INET
     80 #include <netinet/in.h>
     81 #endif
     82 #include <netinet6/in6_var.h>
     83 #include <netinet/ip6.h>
     84 #include <netinet6/ip6_var.h>
     85 #endif
     86 
     87 
     88 #include <net/net_osdep.h>
     89 
     90 #include "ioconf.h"
     91 
     92 static int	faithioctl(struct ifnet *, u_long, void *);
     93 static int	faithoutput(struct ifnet *, struct mbuf *,
     94 		            const struct sockaddr *, const struct rtentry *);
     95 static void	faithrtrequest(int, struct rtentry *,
     96 		               const struct rt_addrinfo *);
     97 
     98 static int	faith_clone_create(struct if_clone *, int);
     99 static int	faith_clone_destroy(struct ifnet *);
    100 
    101 static struct if_clone faith_cloner =
    102     IF_CLONE_INITIALIZER("faith", faith_clone_create, faith_clone_destroy);
    103 
    104 #define	FAITHMTU	1500
    105 
    106 static u_int faith_count;
    107 
    108 /* ARGSUSED */
    109 void
    110 faithattach(int count)
    111 {
    112 
    113 	/*
    114 	 * Nothing to do here, initialization is handled by the
    115 	 * module initialization code in faithinit() below).
    116 	 */
    117 }
    118 
    119 static void
    120 faithinit(void)
    121 {
    122 	if_clone_attach(&faith_cloner);
    123 }
    124 
    125 static int
    126 faithdetach(void)
    127 {
    128 	int error = 0;
    129 
    130 	if (faith_count != 0)
    131 		error = EBUSY;
    132 
    133 	if (error == 0)
    134 		if_clone_detach(&faith_cloner);
    135 
    136 	return error;
    137 }
    138 
    139 static int
    140 faith_clone_create(struct if_clone *ifc, int unit)
    141 {
    142 	struct ifnet *ifp;
    143 
    144 	ifp = if_alloc(IFT_FAITH);
    145 
    146 	if_initname(ifp, ifc->ifc_name, unit);
    147 
    148 	ifp->if_mtu = FAITHMTU;
    149 	/* Change to BROADCAST experimentaly to announce its prefix. */
    150 	ifp->if_flags = /* IFF_LOOPBACK */ IFF_BROADCAST | IFF_MULTICAST;
    151 	ifp->if_ioctl = faithioctl;
    152 	ifp->if_output = faithoutput;
    153 	ifp->if_type = IFT_FAITH;
    154 	ifp->if_hdrlen = 0;
    155 	ifp->if_addrlen = 0;
    156 	ifp->if_dlt = DLT_NULL;
    157 	if_attach(ifp);
    158 	if_alloc_sadl(ifp);
    159 	bpf_attach(ifp, DLT_NULL, sizeof(u_int));
    160 	atomic_inc_uint(&faith_count);
    161 	return (0);
    162 }
    163 
    164 int
    165 faith_clone_destroy(struct ifnet *ifp)
    166 {
    167 
    168 	bpf_detach(ifp);
    169 	if_detach(ifp);
    170 	if_free(ifp);
    171 
    172 	atomic_dec_uint(&faith_count);
    173 	return (0);
    174 }
    175 
    176 static int
    177 faithoutput(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
    178     const struct rtentry *rt)
    179 {
    180 	pktqueue_t *pktq;
    181 	size_t pktlen;
    182 	int s, error;
    183 	uint32_t af;
    184 
    185 	if ((m->m_flags & M_PKTHDR) == 0)
    186 		panic("faithoutput no HDR");
    187 	af = dst->sa_family;
    188 	/* BPF write needs to be handled specially */
    189 	if (af == AF_UNSPEC) {
    190 		af = *(mtod(m, int *));
    191 		m_adj(m, sizeof(int));
    192 	}
    193 
    194 	bpf_mtap_af(ifp, af, m);
    195 
    196 	if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
    197 		m_freem(m);
    198 		return (rt->rt_flags & RTF_BLACKHOLE ? 0 :
    199 		        rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
    200 	}
    201 	pktlen = m->m_pkthdr.len;
    202 	ifp->if_opackets++;
    203 	ifp->if_obytes += pktlen;
    204 	switch (af) {
    205 #ifdef INET
    206 	case AF_INET:
    207 		pktq = ip_pktq;
    208 		break;
    209 #endif
    210 #ifdef INET6
    211 	case AF_INET6:
    212 		pktq = ip6_pktq;
    213 		break;
    214 #endif
    215 	default:
    216 		m_freem(m);
    217 		return EAFNOSUPPORT;
    218 	}
    219 
    220 	/* XXX do we need more sanity checks? */
    221 	KASSERT(pktq != NULL);
    222 	m_set_rcvif(m, ifp);
    223 
    224 	s = splnet();
    225 	if (__predict_true(pktq_enqueue(pktq, m, 0))) {
    226 		ifp->if_ipackets++;
    227 		ifp->if_ibytes += pktlen;
    228 		error = 0;
    229 	} else {
    230 		m_freem(m);
    231 		error = ENOBUFS;
    232 	}
    233 	splx(s);
    234 
    235 	return error;
    236 }
    237 
    238 /* ARGSUSED */
    239 static void
    240 faithrtrequest(int cmd, struct rtentry *rt,
    241     const struct rt_addrinfo *info)
    242 {
    243 	if (rt)
    244 		rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu; /* for ISO */
    245 }
    246 
    247 /*
    248  * Process an ioctl request.
    249  */
    250 /* ARGSUSED */
    251 static int
    252 faithioctl(struct ifnet *ifp, u_long cmd, void *data)
    253 {
    254 	struct ifaddr *ifa;
    255 	struct ifreq *ifr = (struct ifreq *)data;
    256 	int error = 0;
    257 
    258 	switch (cmd) {
    259 
    260 	case SIOCINITIFADDR:
    261 		ifp->if_flags |= IFF_UP | IFF_RUNNING;
    262 		ifa = (struct ifaddr *)data;
    263 		ifa->ifa_rtrequest = faithrtrequest;
    264 		/*
    265 		 * Everything else is done at a higher level.
    266 		 */
    267 		break;
    268 
    269 	case SIOCADDMULTI:
    270 	case SIOCDELMULTI:
    271 		if (ifr == 0) {
    272 			error = EAFNOSUPPORT;		/* XXX */
    273 			break;
    274 		}
    275 		switch (ifr->ifr_addr.sa_family) {
    276 #ifdef INET
    277 		case AF_INET:
    278 			break;
    279 #endif
    280 #ifdef INET6
    281 		case AF_INET6:
    282 			break;
    283 #endif
    284 
    285 		default:
    286 			error = EAFNOSUPPORT;
    287 			break;
    288 		}
    289 		break;
    290 
    291 	default:
    292 		if ((error = ifioctl_common(ifp, cmd, data)) == ENETRESET)
    293 			error = 0;
    294 		break;
    295 	}
    296 	return (error);
    297 }
    298 
    299 #ifdef INET6
    300 /*
    301  * XXX could be slow
    302  * XXX could be layer violation to call sys/net from sys/netinet6
    303  */
    304 int
    305 faithprefix(struct in6_addr *in6)
    306 {
    307 	struct rtentry *rt;
    308 	struct sockaddr_in6 sin6;
    309 	int ret;
    310 
    311 	if (ip6_keepfaith == 0)
    312 		return 0;
    313 
    314 	memset(&sin6, 0, sizeof(sin6));
    315 	sin6.sin6_family = AF_INET6;
    316 	sin6.sin6_len = sizeof(struct sockaddr_in6);
    317 	sin6.sin6_addr = *in6;
    318 	rt = rtalloc1((struct sockaddr *)&sin6, 0);
    319 	if (rt && rt->rt_ifp && rt->rt_ifp->if_type == IFT_FAITH &&
    320 	    (rt->rt_ifp->if_flags & IFF_UP) != 0)
    321 		ret = 1;
    322 	else
    323 		ret = 0;
    324 	if (rt)
    325 		rtfree(rt);
    326 	return ret;
    327 }
    328 #endif
    329 
    330 /*
    331  * Module infrastructure
    332  */
    333 #include "if_module.h"
    334 
    335 IF_MODULE(MODULE_CLASS_DRIVER, faith, "")
    336