xref: /netbsd-src/sys/net/if_faith.c (revision b7b7574d3bf8eeb51a1fa3977b59142ec6434a55)
1 /*	$NetBSD: if_faith.c,v 1.49 2014/06/06 01:02:47 rmind 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 1.49 2014/06/06 01:02:47 rmind 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 	pktqueue_t *pktq;
149 	size_t pktlen;
150 	int s, error;
151 	uint32_t af;
152 
153 	if ((m->m_flags & M_PKTHDR) == 0)
154 		panic("faithoutput no HDR");
155 	af = dst->sa_family;
156 	/* BPF write needs to be handled specially */
157 	if (af == AF_UNSPEC) {
158 		af = *(mtod(m, int *));
159 		m_adj(m, sizeof(int));
160 	}
161 
162 	bpf_mtap_af(ifp, af, m);
163 
164 	if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
165 		m_freem(m);
166 		return (rt->rt_flags & RTF_BLACKHOLE ? 0 :
167 		        rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
168 	}
169 	pktlen = m->m_pkthdr.len;
170 	ifp->if_opackets++;
171 	ifp->if_obytes += pktlen;
172 	switch (af) {
173 #ifdef INET
174 	case AF_INET:
175 		pktq = ip_pktq;
176 		break;
177 #endif
178 #ifdef INET6
179 	case AF_INET6:
180 		pktq = ip6_pktq;
181 		break;
182 #endif
183 	default:
184 		m_freem(m);
185 		return EAFNOSUPPORT;
186 	}
187 
188 	/* XXX do we need more sanity checks? */
189 	KASSERT(pktq != NULL);
190 	m->m_pkthdr.rcvif = ifp;
191 
192 	s = splnet();
193 	if (__predict_true(pktq_enqueue(pktq, m, 0))) {
194 		ifp->if_ipackets++;
195 		ifp->if_ibytes += pktlen;
196 		error = 0;
197 	} else {
198 		m_freem(m);
199 		error = ENOBUFS;
200 	}
201 	splx(s);
202 
203 	return error;
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