xref: /openbsd-src/sys/net/if_loop.c (revision 50b7afb2c2c0993b0894d4e34bf857cb13ed9c80)
1 /*	$OpenBSD: if_loop.c,v 1.56 2014/07/12 18:44:22 tedu Exp $	*/
2 /*	$NetBSD: if_loop.c,v 1.15 1996/05/07 02:40:33 thorpej Exp $	*/
3 
4 /*
5  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
6  * 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 project 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 PROJECT 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 PROJECT 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 /*
34  * Copyright (c) 1982, 1986, 1993
35  *	The Regents of the University of California.  All rights reserved.
36  *
37  * Redistribution and use in source and binary forms, with or without
38  * modification, are permitted provided that the following conditions
39  * are met:
40  * 1. Redistributions of source code must retain the above copyright
41  *    notice, this list of conditions and the following disclaimer.
42  * 2. Redistributions in binary form must reproduce the above copyright
43  *    notice, this list of conditions and the following disclaimer in the
44  *    documentation and/or other materials provided with the distribution.
45  * 3. Neither the name of the University nor the names of its contributors
46  *    may be used to endorse or promote products derived from this software
47  *    without specific prior written permission.
48  *
49  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
50  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
51  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
52  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
53  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
54  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
55  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
56  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
57  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
58  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
59  * SUCH DAMAGE.
60  *
61  *	@(#)if_loop.c	8.1 (Berkeley) 6/10/93
62  */
63 
64 /*
65  *	@(#)COPYRIGHT	1.1 (NRL) 17 January 1995
66  *
67  * NRL grants permission for redistribution and use in source and binary
68  * forms, with or without modification, of the software and documentation
69  * created at NRL provided that the following conditions are met:
70  *
71  * 1. Redistributions of source code must retain the above copyright
72  *    notice, this list of conditions and the following disclaimer.
73  * 2. Redistributions in binary form must reproduce the above copyright
74  *    notice, this list of conditions and the following disclaimer in the
75  *    documentation and/or other materials provided with the distribution.
76  * 3. All advertising materials mentioning features or use of this software
77  *    must display the following acknowledgements:
78  * 	This product includes software developed by the University of
79  * 	California, Berkeley and its contributors.
80  * 	This product includes software developed at the Information
81  * 	Technology Division, US Naval Research Laboratory.
82  * 4. Neither the name of the NRL nor the names of its contributors
83  *    may be used to endorse or promote products derived from this software
84  *    without specific prior written permission.
85  *
86  * THE SOFTWARE PROVIDED BY NRL IS PROVIDED BY NRL AND CONTRIBUTORS ``AS
87  * IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
88  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
89  * PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL NRL OR
90  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
91  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
92  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
93  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
94  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
95  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
96  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
97  *
98  * The views and conclusions contained in the software and documentation
99  * are those of the authors and should not be interpreted as representing
100  * official policies, either expressed or implied, of the US Naval
101  * Research Laboratory (NRL).
102  */
103 
104 /*
105  * Loopback interface driver for protocol testing and timing.
106  */
107 
108 #include "bpfilter.h"
109 
110 #include <sys/param.h>
111 #include <sys/systm.h>
112 #include <sys/kernel.h>
113 #include <sys/mbuf.h>
114 #include <sys/socket.h>
115 #include <sys/errno.h>
116 #include <sys/ioctl.h>
117 #include <sys/time.h>
118 
119 
120 #include <net/if.h>
121 #include <net/if_types.h>
122 #include <net/netisr.h>
123 #include <net/route.h>
124 
125 #ifdef	INET
126 #include <netinet/in.h>
127 #include <netinet/in_systm.h>
128 #include <netinet/ip.h>
129 #endif
130 
131 #ifdef INET6
132 #ifndef INET
133 #include <netinet/in.h>
134 #endif
135 #include <netinet/ip6.h>
136 #endif
137 
138 #ifdef MPLS
139 #include <netmpls/mpls.h>
140 #endif
141 
142 #if NBPFILTER > 0
143 #include <net/bpf.h>
144 #endif
145 
146 #define	LOMTU	32768
147 
148 int	loop_clone_create(struct if_clone *, int);
149 int	loop_clone_destroy(struct ifnet *);
150 
151 struct if_clone loop_cloner =
152     IF_CLONE_INITIALIZER("lo", loop_clone_create, loop_clone_destroy);
153 
154 /* ARGSUSED */
155 void
156 loopattach(int n)
157 {
158 	(void) loop_clone_create(&loop_cloner, 0);
159 	if_clone_attach(&loop_cloner);
160 }
161 
162 int
163 loop_clone_create(struct if_clone *ifc, int unit)
164 {
165 	struct ifnet *ifp;
166 
167 	ifp = malloc(sizeof(*ifp), M_DEVBUF, M_NOWAIT|M_ZERO);
168 	if (ifp == NULL)
169 		return (ENOMEM);
170 
171 	snprintf(ifp->if_xname, sizeof ifp->if_xname, "lo%d", unit);
172 	ifp->if_softc = NULL;
173 	ifp->if_mtu = LOMTU;
174 	ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST;
175 	ifp->if_ioctl = loioctl;
176 	ifp->if_output = looutput;
177 	ifp->if_type = IFT_LOOP;
178 	ifp->if_hdrlen = sizeof(u_int32_t);
179 	ifp->if_addrlen = 0;
180 	IFQ_SET_READY(&ifp->if_snd);
181 	if (unit == 0) {
182 		lo0ifp = ifp;
183 		if_attachhead(ifp);
184 		if_addgroup(lo0ifp, ifc->ifc_name);
185 	} else
186 		if_attach(ifp);
187 	if_alloc_sadl(ifp);
188 #if NBPFILTER > 0
189 	bpfattach(&ifp->if_bpf, ifp, DLT_LOOP, sizeof(u_int32_t));
190 #endif
191 	return (0);
192 }
193 
194 int
195 loop_clone_destroy(struct ifnet *ifp)
196 {
197 	if (ifp == lo0ifp)
198 		return (EPERM);
199 
200 	if_detach(ifp);
201 
202 	free(ifp, M_DEVBUF, 0);
203 	return (0);
204 }
205 
206 int
207 looutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
208     struct rtentry *rt)
209 {
210 	int s, isr;
211 	struct ifqueue *ifq = 0;
212 
213 	if ((m->m_flags & M_PKTHDR) == 0)
214 		panic("looutput: no header mbuf");
215 #if NBPFILTER > 0
216 	/*
217 	 * only send packets to bpf if they are real loopback packets;
218 	 * looutput() is also called for SIMPLEX interfaces to duplicate
219 	 * packets for local use. But don't dup them to bpf.
220 	 */
221 	if (ifp->if_bpf && (ifp->if_flags & IFF_LOOPBACK))
222 		bpf_mtap_af(ifp->if_bpf, dst->sa_family, m, BPF_DIRECTION_OUT);
223 #endif
224 	m->m_pkthdr.rcvif = ifp;
225 
226 	if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
227 		m_freem(m);
228 		return (rt->rt_flags & RTF_BLACKHOLE ? 0 :
229 			rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
230 	}
231 
232 	ifp->if_opackets++;
233 	ifp->if_obytes += m->m_pkthdr.len;
234 	switch (dst->sa_family) {
235 
236 #ifdef INET
237 	case AF_INET:
238 		ifq = &ipintrq;
239 		isr = NETISR_IP;
240 		break;
241 #endif
242 #ifdef INET6
243 	case AF_INET6:
244 		ifq = &ip6intrq;
245 		isr = NETISR_IPV6;
246 		break;
247 #endif /* INET6 */
248 #ifdef MPLS
249 	case AF_MPLS:
250 		ifq = &mplsintrq;
251 		isr = NETISR_MPLS;
252 		break;
253 #endif /* MPLS */
254 	default:
255 		printf("%s: can't handle af%d\n", ifp->if_xname,
256 			dst->sa_family);
257 		m_freem(m);
258 		return (EAFNOSUPPORT);
259 	}
260 	s = splnet();
261 	if (IF_QFULL(ifq)) {
262 		IF_DROP(ifq);
263 		m_freem(m);
264 		splx(s);
265 		return (ENOBUFS);
266 	}
267 	IF_ENQUEUE(ifq, m);
268 	schednetisr(isr);
269 	ifp->if_ipackets++;
270 	ifp->if_ibytes += m->m_pkthdr.len;
271 	splx(s);
272 	return (0);
273 }
274 
275 /* ARGSUSED */
276 void
277 lortrequest(int cmd, struct rtentry *rt)
278 {
279 	if (rt)
280 		rt->rt_rmx.rmx_mtu = LOMTU;
281 }
282 
283 /*
284  * Process an ioctl request.
285  */
286 /* ARGSUSED */
287 int
288 loioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
289 {
290 	struct ifaddr *ifa;
291 	struct ifreq *ifr;
292 	int s, error = 0;
293 
294 	switch (cmd) {
295 
296 	case SIOCSIFADDR:
297 		s = splnet();
298 		ifp->if_flags |= IFF_RUNNING;
299 		if_up(ifp);		/* send up RTM_IFINFO */
300 		splx(s);
301 
302 		ifa = (struct ifaddr *)data;
303 		if (ifa != 0)
304 			ifa->ifa_rtrequest = lortrequest;
305 		/*
306 		 * Everything else is done at a higher level.
307 		 */
308 		break;
309 
310 	case SIOCADDMULTI:
311 	case SIOCDELMULTI:
312 		break;
313 
314 	case SIOCSIFMTU:
315 		ifr = (struct ifreq *)data;
316 		ifp->if_mtu = ifr->ifr_mtu;
317 		break;
318 
319 	default:
320 		error = ENOTTY;
321 	}
322 	return (error);
323 }
324