xref: /openbsd-src/sys/net/if_loop.c (revision a28daedfc357b214be5c701aa8ba8adb29a7f1c2)
1 /*	$OpenBSD: if_loop.c,v 1.44 2008/05/07 12:58:54 norby 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 #include <machine/cpu.h>
120 
121 #include <net/if.h>
122 #include <net/if_types.h>
123 #include <net/netisr.h>
124 #include <net/route.h>
125 
126 #ifdef	INET
127 #include <netinet/in.h>
128 #include <netinet/in_systm.h>
129 #include <netinet/in_var.h>
130 #include <netinet/ip.h>
131 #endif
132 
133 #ifdef INET6
134 #ifndef INET
135 #include <netinet/in.h>
136 #endif
137 #include <netinet6/in6_var.h>
138 #include <netinet/ip6.h>
139 #endif
140 
141 #ifdef NETATALK
142 #include <netinet/if_ether.h>
143 #include <netatalk/at.h>
144 #include <netatalk/at_var.h>
145 #endif
146 
147 #ifdef MPLS
148 #include <netmpls/mpls.h>
149 #endif
150 
151 #if NBPFILTER > 0
152 #include <net/bpf.h>
153 #endif
154 
155 #if defined(LARGE_LOMTU)
156 #define LOMTU	(131072 +  MHLEN + MLEN)
157 #else
158 #define	LOMTU	(32768 +  MHLEN + MLEN)
159 #endif
160 
161 #ifdef ALTQ
162 static void lo_altqstart(struct ifnet *);
163 #endif
164 
165 int	loop_clone_create(struct if_clone *, int);
166 int	loop_clone_destroy(struct ifnet *);
167 
168 struct if_clone loop_cloner =
169     IF_CLONE_INITIALIZER("lo", loop_clone_create, loop_clone_destroy);
170 
171 /* ARGSUSED */
172 void
173 loopattach(n)
174 	int n;
175 {
176 	(void) loop_clone_create(&loop_cloner, 0);
177 	if_clone_attach(&loop_cloner);
178 }
179 
180 int
181 loop_clone_create(ifc, unit)
182 	struct if_clone *ifc;
183 	int unit;
184 {
185 	struct ifnet *ifp;
186 
187 	ifp = malloc(sizeof(*ifp), M_DEVBUF, M_NOWAIT|M_ZERO);
188 	if (ifp == NULL)
189 		return (ENOMEM);
190 
191 	snprintf(ifp->if_xname, sizeof ifp->if_xname, "lo%d", unit);
192 	ifp->if_softc = NULL;
193 	ifp->if_mtu = LOMTU;
194 	ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST;
195 	ifp->if_ioctl = loioctl;
196 	ifp->if_output = looutput;
197 	ifp->if_type = IFT_LOOP;
198 	ifp->if_hdrlen = sizeof(u_int32_t);
199 	ifp->if_addrlen = 0;
200 	IFQ_SET_READY(&ifp->if_snd);
201 #ifdef ALTQ
202 	ifp->if_start = lo_altqstart;
203 #endif
204 	if (unit == 0) {
205 		lo0ifp = ifp;
206 		if_attachhead(ifp);
207 		if_addgroup(lo0ifp, ifc->ifc_name);
208 	} else
209 		if_attach(ifp);
210 	if_alloc_sadl(ifp);
211 #if NBPFILTER > 0
212 	bpfattach(&ifp->if_bpf, ifp, DLT_LOOP, sizeof(u_int32_t));
213 #endif
214 	return (0);
215 }
216 
217 int
218 loop_clone_destroy(ifp)
219 	struct ifnet *ifp;
220 {
221 	if (ifp == lo0ifp)
222 		return (EPERM);
223 
224 	if_detach(ifp);
225 
226 	free(ifp, M_DEVBUF);
227 	return (0);
228 }
229 
230 int
231 looutput(ifp, m, dst, rt)
232 	struct ifnet *ifp;
233 	struct mbuf *m;
234 	struct sockaddr *dst;
235 	struct rtentry *rt;
236 {
237 	int s, isr;
238 	struct ifqueue *ifq = 0;
239 
240 	if ((m->m_flags & M_PKTHDR) == 0)
241 		panic("looutput: no header mbuf");
242 #if NBPFILTER > 0
243 	/*
244 	 * only send packets to bpf if they are real loopback packets;
245 	 * looutput() is also called for SIMPLEX interfaces to duplicate
246 	 * packets for local use. But don't dup them to bpf.
247 	 */
248 	if (ifp->if_bpf && (ifp->if_flags & IFF_LOOPBACK))
249 		bpf_mtap_af(ifp->if_bpf, htonl(dst->sa_family), m,
250 		    BPF_DIRECTION_OUT);
251 #endif
252 	m->m_pkthdr.rcvif = ifp;
253 
254 	if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
255 		m_freem(m);
256 		return (rt->rt_flags & RTF_BLACKHOLE ? 0 :
257 			rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
258 	}
259 
260 	ifp->if_opackets++;
261 	ifp->if_obytes += m->m_pkthdr.len;
262 #ifdef ALTQ
263 	/*
264 	 * altq for loop is just for debugging.
265 	 * only used when called for loop interface (not for
266 	 * a simplex interface).
267 	 */
268 	if ((ALTQ_IS_ENABLED(&ifp->if_snd) || TBR_IS_ENABLED(&ifp->if_snd))
269 	    && ifp->if_start == lo_altqstart) {
270 		int32_t *afp;
271 	        int error;
272 
273 		M_PREPEND(m, sizeof(int32_t), M_DONTWAIT);
274 		if (m == 0)
275 			return (ENOBUFS);
276 		afp = mtod(m, int32_t *);
277 		*afp = (int32_t)dst->sa_family;
278 
279 	        s = splnet();
280 		IFQ_ENQUEUE(&ifp->if_snd, m, NULL, error);
281 		(*ifp->if_start)(ifp);
282 		splx(s);
283 		return (error);
284 	}
285 #endif /* ALTQ */
286 	switch (dst->sa_family) {
287 
288 #ifdef INET
289 	case AF_INET:
290 		ifq = &ipintrq;
291 		isr = NETISR_IP;
292 		break;
293 #endif
294 #ifdef INET6
295 	case AF_INET6:
296 		ifq = &ip6intrq;
297 		isr = NETISR_IPV6;
298 		break;
299 #endif /* INET6 */
300 #ifdef NETATALK
301 	case AF_APPLETALK:
302 		ifq = &atintrq2;
303 		isr = NETISR_ATALK;
304 		break;
305 #endif /* NETATALK */
306 #ifdef MPLS
307 	case AF_MPLS:
308 		ifq = &mplsintrq;
309 		isr = NETISR_MPLS;
310 		break;
311 #endif /* MPLS */
312 	default:
313 		printf("%s: can't handle af%d\n", ifp->if_xname,
314 			dst->sa_family);
315 		m_freem(m);
316 		return (EAFNOSUPPORT);
317 	}
318 	s = splnet();
319 	if (IF_QFULL(ifq)) {
320 		IF_DROP(ifq);
321 		m_freem(m);
322 		splx(s);
323 		return (ENOBUFS);
324 	}
325 	IF_ENQUEUE(ifq, m);
326 	schednetisr(isr);
327 	ifp->if_ipackets++;
328 	ifp->if_ibytes += m->m_pkthdr.len;
329 	splx(s);
330 	return (0);
331 }
332 
333 #ifdef ALTQ
334 static void
335 lo_altqstart(ifp)
336 	struct ifnet *ifp;
337 {
338 	struct ifqueue *ifq;
339 	struct mbuf *m;
340 	int32_t af, *afp;
341 	int s, isr;
342 
343 	while (1) {
344 		s = splnet();
345 		IFQ_DEQUEUE(&ifp->if_snd, m);
346 		splx(s);
347 		if (m == NULL)
348 			return;
349 
350 		afp = mtod(m, int32_t *);
351 		af = *afp;
352 		m_adj(m, sizeof(int32_t));
353 
354 		switch (af) {
355 #ifdef INET
356 		case AF_INET:
357 			ifq = &ipintrq;
358 			isr = NETISR_IP;
359 			break;
360 #endif
361 #ifdef INET6
362 		case AF_INET6:
363 			m->m_flags |= M_LOOP;
364 			ifq = &ip6intrq;
365 			isr = NETISR_IPV6;
366 			break;
367 #endif
368 #ifdef MPLS
369 		case AF_MPLS:
370 			ifq = &mplsintrq;
371 			isr = NETISR_MPLS;
372 			break;
373 #endif
374 #ifdef NETATALK
375 		case AF_APPLETALK:
376 			ifq = &atintrq2;
377 			isr = NETISR_ATALK;
378 			break;
379 #endif /* NETATALK */
380 		default:
381 			printf("lo_altqstart: can't handle af%d\n", af);
382 			m_freem(m);
383 			return;
384 		}
385 
386 		s = splnet();
387 		if (IF_QFULL(ifq)) {
388 			IF_DROP(ifq);
389 			m_freem(m);
390 			splx(s);
391 			return;
392 		}
393 		IF_ENQUEUE(ifq, m);
394 		schednetisr(isr);
395 		ifp->if_ipackets++;
396 		ifp->if_ibytes += m->m_pkthdr.len;
397 		splx(s);
398 	}
399 }
400 #endif /* ALTQ */
401 
402 /* ARGSUSED */
403 void
404 lortrequest(cmd, rt, info)
405 	int cmd;
406 	struct rtentry *rt;
407 	struct rt_addrinfo *info;
408 {
409 
410 	if (rt)
411 		rt->rt_rmx.rmx_mtu = LOMTU;
412 }
413 
414 /*
415  * Process an ioctl request.
416  */
417 /* ARGSUSED */
418 int
419 loioctl(ifp, cmd, data)
420 	struct ifnet *ifp;
421 	u_long cmd;
422 	caddr_t data;
423 {
424 	struct ifaddr *ifa;
425 	struct ifreq *ifr;
426 	int error = 0;
427 
428 	switch (cmd) {
429 
430 	case SIOCSIFADDR:
431 		ifp->if_flags |= IFF_UP | IFF_RUNNING;
432 		ifa = (struct ifaddr *)data;
433 		if (ifa != 0)
434 			ifa->ifa_rtrequest = lortrequest;
435 		/*
436 		 * Everything else is done at a higher level.
437 		 */
438 		break;
439 
440 	case SIOCADDMULTI:
441 	case SIOCDELMULTI:
442 		ifr = (struct ifreq *)data;
443 		if (ifr == 0) {
444 			error = EAFNOSUPPORT;		/* XXX */
445 			break;
446 		}
447 		switch (ifr->ifr_addr.sa_family) {
448 
449 #ifdef INET
450 		case AF_INET:
451 			break;
452 #endif
453 #ifdef INET6
454 		case AF_INET6:
455 			break;
456 #endif /* INET6 */
457 
458 		default:
459 			error = EAFNOSUPPORT;
460 			break;
461 		}
462 		break;
463 
464 	case SIOCSIFMTU:
465 		ifr = (struct ifreq *)data;
466 		ifp->if_mtu = ifr->ifr_mtu;
467 		break;
468 
469 	default:
470 		error = ENOTTY;
471 	}
472 	return (error);
473 }
474