xref: /netbsd-src/sys/net/if_faith.c (revision 8b0f9554ff8762542c4defc4f70e1eb76fb508fa)
1 /*	$NetBSD: if_faith.c,v 1.40 2007/10/19 12:16:44 ad 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 1.40 2007/10/19 12:16:44 ad 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 		ifp->if_mtu = ifr->ifr_mtu;
270 		break;
271 #endif
272 
273 	case SIOCSIFFLAGS:
274 		break;
275 
276 	default:
277 		error = EINVAL;
278 	}
279 	return (error);
280 }
281 
282 #ifdef INET6
283 /*
284  * XXX could be slow
285  * XXX could be layer violation to call sys/net from sys/netinet6
286  */
287 int
288 faithprefix(struct in6_addr *in6)
289 {
290 	struct rtentry *rt;
291 	struct sockaddr_in6 sin6;
292 	int ret;
293 
294 	if (ip6_keepfaith == 0)
295 		return 0;
296 
297 	memset(&sin6, 0, sizeof(sin6));
298 	sin6.sin6_family = AF_INET6;
299 	sin6.sin6_len = sizeof(struct sockaddr_in6);
300 	sin6.sin6_addr = *in6;
301 	rt = rtalloc1((struct sockaddr *)&sin6, 0);
302 	if (rt && rt->rt_ifp && rt->rt_ifp->if_type == IFT_FAITH &&
303 	    (rt->rt_ifp->if_flags & IFF_UP) != 0)
304 		ret = 1;
305 	else
306 		ret = 0;
307 	if (rt)
308 		RTFREE(rt);
309 	return ret;
310 }
311 #endif
312