xref: /openbsd-src/sys/net/if_loop.c (revision db3296cf5c1dd9058ceecc3a29fe4aaa0bd26000)
1 /*	$OpenBSD: if_loop.c,v 1.29 2003/06/02 23:28:12 millert 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 NS
142 #include <netns/ns.h>
143 #include <netns/ns_if.h>
144 #endif
145 
146 #ifdef IPX
147 #include <netipx/ipx.h>
148 #include <netipx/ipx_if.h>
149 #endif
150 
151 #ifdef ISO
152 #include <netiso/iso.h>
153 #include <netiso/iso_var.h>
154 #endif
155 
156 #ifdef NETATALK
157 #include <netinet/if_ether.h>
158 #include <netatalk/at.h>
159 #include <netatalk/at_var.h>
160 #endif
161 
162 #if NBPFILTER > 0
163 #include <net/bpf.h>
164 #endif
165 
166 #if defined(LARGE_LOMTU)
167 #define LOMTU	(131072 +  MHLEN + MLEN)
168 #else
169 #define	LOMTU	(32768 +  MHLEN + MLEN)
170 #endif
171 
172 #ifdef ALTQ
173 static void lo_altqstart(struct ifnet *);
174 #endif
175 
176 void
177 loopattach(n)
178 	int n;
179 {
180 	register int i;
181 	register struct ifnet *ifp;
182 
183 	for (i = n; i--; ) {
184 		MALLOC(ifp, struct ifnet *, sizeof(*ifp), M_DEVBUF, M_NOWAIT);
185 		if (ifp == NULL)
186 			return;
187 		bzero(ifp, sizeof(struct ifnet));
188 		if (i == 0)
189 			lo0ifp = ifp;
190 		snprintf(ifp->if_xname, sizeof ifp->if_xname, "lo%d", i);
191 		ifp->if_softc = NULL;
192 		ifp->if_mtu = LOMTU;
193 		ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST;
194 		ifp->if_ioctl = loioctl;
195 		ifp->if_output = looutput;
196 		ifp->if_type = IFT_LOOP;
197 		ifp->if_hdrlen = sizeof(u_int32_t);
198 		ifp->if_addrlen = 0;
199 		IFQ_SET_READY(&ifp->if_snd);
200 #ifdef ALTQ
201 		ifp->if_start = lo_altqstart;
202 #endif
203 		if_attachhead(ifp);
204 		if_alloc_sadl(ifp);
205 #if NBPFILTER > 0
206 		bpfattach(&ifp->if_bpf, ifp, DLT_LOOP, sizeof(u_int32_t));
207 #endif
208 	}
209 }
210 
211 int
212 looutput(ifp, m, dst, rt)
213 	struct ifnet *ifp;
214 	register struct mbuf *m;
215 	struct sockaddr *dst;
216 	register struct rtentry *rt;
217 {
218 	int s, isr;
219 	register struct ifqueue *ifq = 0;
220 
221 	if ((m->m_flags & M_PKTHDR) == 0)
222 		panic("looutput: no header mbuf");
223 #if NBPFILTER > 0
224 	/*
225 	 * only send packets to bpf if they are real loopback packets;
226 	 * looutput() is also called for SIMPLEX interfaces to duplicate
227 	 * packets for local use. But don't dup them to bpf.
228 	 */
229 	if (ifp->if_bpf && (ifp->if_flags&IFF_LOOPBACK)) {
230 		/*
231 		 * We need to prepend the address family as
232 		 * a four byte field.  Cons up a dummy header
233 		 * to pacify bpf.  This is safe because bpf
234 		 * will only read from the mbuf (i.e., it won't
235 		 * try to free it or keep a pointer to it).
236 		 */
237 		struct mbuf m0;
238 		u_int32_t af = htonl(dst->sa_family);
239 
240 		m0.m_flags = 0;
241 		m0.m_next = m;
242 		m0.m_len = sizeof(af);
243 		m0.m_data = (char *)&af;
244 
245 		bpf_mtap(ifp->if_bpf, &m0);
246 	}
247 #endif
248 	m->m_pkthdr.rcvif = ifp;
249 
250 	if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
251 		m_freem(m);
252 		return (rt->rt_flags & RTF_BLACKHOLE ? 0 :
253 			rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
254 	}
255 
256 	ifp->if_opackets++;
257 	ifp->if_obytes += m->m_pkthdr.len;
258 #ifdef ALTQ
259 	/*
260 	 * altq for loop is just for debugging.
261 	 * only used when called for loop interface (not for
262 	 * a simplex interface).
263 	 */
264 	if ((ALTQ_IS_ENABLED(&ifp->if_snd) || TBR_IS_ENABLED(&ifp->if_snd))
265 	    && ifp->if_start == lo_altqstart) {
266 		int32_t *afp;
267 	        int error;
268 
269 		M_PREPEND(m, sizeof(int32_t), M_DONTWAIT);
270 		if (m == 0)
271 			return (ENOBUFS);
272 		afp = mtod(m, int32_t *);
273 		*afp = (int32_t)dst->sa_family;
274 
275 	        s = splimp();
276 		IFQ_ENQUEUE(&ifp->if_snd, m, NULL, error);
277 		(*ifp->if_start)(ifp);
278 		splx(s);
279 		return (error);
280 	}
281 #endif /* ALTQ */
282 	switch (dst->sa_family) {
283 
284 #ifdef INET
285 	case AF_INET:
286 		ifq = &ipintrq;
287 		isr = NETISR_IP;
288 		break;
289 #endif
290 #ifdef INET6
291 	case AF_INET6:
292 		ifq = &ip6intrq;
293 		isr = NETISR_IPV6;
294 		break;
295 #endif /* INET6 */
296 #ifdef NS
297 	case AF_NS:
298 		ifq = &nsintrq;
299 		isr = NETISR_NS;
300 		break;
301 #endif
302 #ifdef IPX
303 	case AF_IPX:
304 		ifq = &ipxintrq;
305 		isr = NETISR_IPX;
306 		break;
307 #endif
308 #ifdef ISO
309 	case AF_ISO:
310 		ifq = &clnlintrq;
311 		isr = NETISR_ISO;
312 		break;
313 #endif
314 #ifdef NETATALK
315 	case AF_APPLETALK:
316 		ifq = &atintrq2;
317 		isr = NETISR_ATALK;
318 		break;
319 #endif /* NETATALK */
320 	default:
321 		printf("%s: can't handle af%d\n", ifp->if_xname,
322 			dst->sa_family);
323 		m_freem(m);
324 		return (EAFNOSUPPORT);
325 	}
326 	s = splimp();
327 	if (IF_QFULL(ifq)) {
328 		IF_DROP(ifq);
329 		m_freem(m);
330 		splx(s);
331 		return (ENOBUFS);
332 	}
333 	IF_ENQUEUE(ifq, m);
334 	schednetisr(isr);
335 	ifp->if_ipackets++;
336 	ifp->if_ibytes += m->m_pkthdr.len;
337 	splx(s);
338 	return (0);
339 }
340 
341 #ifdef ALTQ
342 static void
343 lo_altqstart(ifp)
344 	struct ifnet *ifp;
345 {
346 	struct ifqueue *ifq;
347 	struct mbuf *m;
348 	int32_t af, *afp;
349 	int s, isr;
350 
351 	while (1) {
352 		s = splimp();
353 		IFQ_DEQUEUE(&ifp->if_snd, m);
354 		splx(s);
355 		if (m == NULL)
356 			return;
357 
358 		afp = mtod(m, int32_t *);
359 		af = *afp;
360 		m_adj(m, sizeof(int32_t));
361 
362 		switch (af) {
363 #ifdef INET
364 		case AF_INET:
365 			ifq = &ipintrq;
366 			isr = NETISR_IP;
367 			break;
368 #endif
369 #ifdef INET6
370 		case AF_INET6:
371 			m->m_flags |= M_LOOP;
372 			ifq = &ip6intrq;
373 			isr = NETISR_IPV6;
374 			break;
375 #endif
376 #ifdef IPX
377 		case AF_IPX:
378 			ifq = &ipxintrq;
379 			isr = NETISR_IPX;
380 			break;
381 #endif
382 #ifdef NS
383 		case AF_NS:
384 			ifq = &nsintrq;
385 			isr = NETISR_NS;
386 			break;
387 #endif
388 #ifdef ISO
389 		case AF_ISO:
390 			ifq = &clnlintrq;
391 			isr = NETISR_ISO;
392 			break;
393 #endif
394 #ifdef NETATALK
395 		case AF_APPLETALK:
396 			ifq = &atintrq2;
397 			isr = NETISR_ATALK;
398 			break;
399 #endif /* NETATALK */
400 		default:
401 			printf("lo_altqstart: can't handle af%d\n", af);
402 			m_freem(m);
403 			return;
404 		}
405 
406 		s = splimp();
407 		if (IF_QFULL(ifq)) {
408 			IF_DROP(ifq);
409 			m_freem(m);
410 			splx(s);
411 			return;
412 		}
413 		IF_ENQUEUE(ifq, m);
414 		schednetisr(isr);
415 		ifp->if_ipackets++;
416 		ifp->if_ibytes += m->m_pkthdr.len;
417 		splx(s);
418 	}
419 }
420 #endif /* ALTQ */
421 
422 /* ARGSUSED */
423 void
424 lortrequest(cmd, rt, info)
425 	int cmd;
426 	struct rtentry *rt;
427 	struct rt_addrinfo *info;
428 {
429 
430 	if (rt)
431 		rt->rt_rmx.rmx_mtu = LOMTU;
432 }
433 
434 /*
435  * Process an ioctl request.
436  */
437 /* ARGSUSED */
438 int
439 loioctl(ifp, cmd, data)
440 	register struct ifnet *ifp;
441 	u_long cmd;
442 	caddr_t data;
443 {
444 	register struct ifaddr *ifa;
445 	register struct ifreq *ifr;
446 	register int error = 0;
447 
448 	switch (cmd) {
449 
450 	case SIOCSIFADDR:
451 		ifp->if_flags |= IFF_UP | IFF_RUNNING;
452 		ifa = (struct ifaddr *)data;
453 		if (ifa != 0 /*&& ifa->ifa_addr->sa_family == AF_ISO*/)
454 			ifa->ifa_rtrequest = lortrequest;
455 		/*
456 		 * Everything else is done at a higher level.
457 		 */
458 		break;
459 
460 	case SIOCADDMULTI:
461 	case SIOCDELMULTI:
462 		ifr = (struct ifreq *)data;
463 		if (ifr == 0) {
464 			error = EAFNOSUPPORT;		/* XXX */
465 			break;
466 		}
467 		switch (ifr->ifr_addr.sa_family) {
468 
469 #ifdef INET
470 		case AF_INET:
471 			break;
472 #endif
473 #ifdef INET6
474 		case AF_INET6:
475 			break;
476 #endif /* INET6 */
477 
478 		default:
479 			error = EAFNOSUPPORT;
480 			break;
481 		}
482 		break;
483 
484 	case SIOCSIFMTU:
485 		ifr = (struct ifreq *)data;
486 		ifp->if_mtu = ifr->ifr_mtu;
487 		break;
488 
489 	default:
490 		error = EINVAL;
491 	}
492 	return (error);
493 }
494