xref: /openbsd-src/sys/net/if_loop.c (revision 3a3fbb3f2e2521ab7c4a56b7ff7462ebd9095ec5)
1 /*	$OpenBSD: if_loop.c,v 1.22 2002/01/02 20:56:14 dugsong 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. All advertising materials mentioning features or use of this software
46  *    must display the following acknowledgement:
47  *	This product includes software developed by the University of
48  *	California, Berkeley and its contributors.
49  * 4. Neither the name of the University nor the names of its contributors
50  *    may be used to endorse or promote products derived from this software
51  *    without specific prior written permission.
52  *
53  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
54  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
55  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
56  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
57  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
58  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
59  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
60  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
61  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
62  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
63  * SUCH DAMAGE.
64  *
65  *	@(#)if_loop.c	8.1 (Berkeley) 6/10/93
66  */
67 
68 /*
69  *	@(#)COPYRIGHT	1.1 (NRL) 17 January 1995
70  *
71  * NRL grants permission for redistribution and use in source and binary
72  * forms, with or without modification, of the software and documentation
73  * created at NRL provided that the following conditions are met:
74  *
75  * 1. Redistributions of source code must retain the above copyright
76  *    notice, this list of conditions and the following disclaimer.
77  * 2. Redistributions in binary form must reproduce the above copyright
78  *    notice, this list of conditions and the following disclaimer in the
79  *    documentation and/or other materials provided with the distribution.
80  * 3. All advertising materials mentioning features or use of this software
81  *    must display the following acknowledgements:
82  * 	This product includes software developed by the University of
83  * 	California, Berkeley and its contributors.
84  * 	This product includes software developed at the Information
85  * 	Technology Division, US Naval Research Laboratory.
86  * 4. Neither the name of the NRL nor the names of its contributors
87  *    may be used to endorse or promote products derived from this software
88  *    without specific prior written permission.
89  *
90  * THE SOFTWARE PROVIDED BY NRL IS PROVIDED BY NRL AND CONTRIBUTORS ``AS
91  * IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
92  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
93  * PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL NRL OR
94  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
95  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
96  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
97  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
98  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
99  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
100  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
101  *
102  * The views and conclusions contained in the software and documentation
103  * are those of the authors and should not be interpreted as representing
104  * official policies, either expressed or implied, of the US Naval
105  * Research Laboratory (NRL).
106  */
107 
108 /*
109  * Loopback interface driver for protocol testing and timing.
110  */
111 
112 #include "bpfilter.h"
113 
114 #include <sys/param.h>
115 #include <sys/systm.h>
116 #include <sys/kernel.h>
117 #include <sys/mbuf.h>
118 #include <sys/socket.h>
119 #include <sys/errno.h>
120 #include <sys/ioctl.h>
121 #include <sys/time.h>
122 
123 #include <machine/cpu.h>
124 
125 #include <net/if.h>
126 #include <net/if_types.h>
127 #include <net/netisr.h>
128 #include <net/route.h>
129 
130 #ifdef	INET
131 #include <netinet/in.h>
132 #include <netinet/in_systm.h>
133 #include <netinet/in_var.h>
134 #include <netinet/ip.h>
135 #endif
136 
137 #ifdef INET6
138 #ifndef INET
139 #include <netinet/in.h>
140 #endif
141 #include <netinet6/in6_var.h>
142 #include <netinet/ip6.h>
143 #endif
144 
145 #ifdef NS
146 #include <netns/ns.h>
147 #include <netns/ns_if.h>
148 #endif
149 
150 #ifdef IPX
151 #include <netipx/ipx.h>
152 #include <netipx/ipx_if.h>
153 #endif
154 
155 #ifdef ISO
156 #include <netiso/iso.h>
157 #include <netiso/iso_var.h>
158 #endif
159 
160 #ifdef NETATALK
161 #include <netinet/if_ether.h>
162 #include <netatalk/at.h>
163 #include <netatalk/at_var.h>
164 #endif
165 
166 #if NBPFILTER > 0
167 #include <net/bpf.h>
168 #endif
169 
170 #if defined(LARGE_LOMTU)
171 #define LOMTU	(131072 +  MHLEN + MLEN)
172 #else
173 #define	LOMTU	(32768 +  MHLEN + MLEN)
174 #endif
175 
176 #ifdef ALTQ
177 static void lo_altqstart __P((struct ifnet *));
178 #endif
179 
180 void
181 loopattach(n)
182 	int n;
183 {
184 	register int i;
185 	register struct ifnet *ifp;
186 
187 	for (i = n; i--; ) {
188 		MALLOC(ifp, struct ifnet *, sizeof(*ifp), M_DEVBUF, M_NOWAIT);
189 		if (ifp == NULL)
190 			return;
191 		bzero(ifp, sizeof(struct ifnet));
192 		if (i == 0)
193 			lo0ifp = ifp;
194 		sprintf(ifp->if_xname, "lo%d", i);
195 		ifp->if_softc = NULL;
196 		ifp->if_mtu = LOMTU;
197 		ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST;
198 		ifp->if_ioctl = loioctl;
199 		ifp->if_output = looutput;
200 		ifp->if_type = IFT_LOOP;
201 		ifp->if_hdrlen = sizeof(u_int32_t);
202 		ifp->if_addrlen = 0;
203 		IFQ_SET_READY(&ifp->if_snd);
204 #ifdef ALTQ
205 		ifp->if_start = lo_altqstart;
206 #endif
207 		if_attachhead(ifp);
208 #if NBPFILTER > 0
209 		bpfattach(&ifp->if_bpf, ifp, DLT_LOOP, sizeof(u_int32_t));
210 #endif
211 	}
212 }
213 
214 int
215 looutput(ifp, m, dst, rt)
216 	struct ifnet *ifp;
217 	register struct mbuf *m;
218 	struct sockaddr *dst;
219 	register struct rtentry *rt;
220 {
221 	int s, isr;
222 	register struct ifqueue *ifq = 0;
223 
224 	if ((m->m_flags & M_PKTHDR) == 0)
225 		panic("looutput: no header mbuf");
226 #if NBPFILTER > 0
227 	/*
228 	 * only send packets to bpf if they are real loopback packets;
229 	 * looutput() is also called for SIMPLEX interfaces to duplicate
230 	 * packets for local use. But don't dup them to bpf.
231 	 */
232 	if (ifp->if_bpf && (ifp->if_flags&IFF_LOOPBACK)) {
233 		/*
234 		 * We need to prepend the address family as
235 		 * a four byte field.  Cons up a dummy header
236 		 * to pacify bpf.  This is safe because bpf
237 		 * will only read from the mbuf (i.e., it won't
238 		 * try to free it or keep a pointer to it).
239 		 */
240 		struct mbuf m0;
241 		u_int32_t af = htonl(dst->sa_family);
242 
243 		m0.m_next = m;
244 		m0.m_len = sizeof(af);
245 		m0.m_data = (char *)&af;
246 
247 		bpf_mtap(ifp->if_bpf, &m0);
248 	}
249 #endif
250 	m->m_pkthdr.rcvif = ifp;
251 
252 	if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
253 		m_freem(m);
254 		return (rt->rt_flags & RTF_BLACKHOLE ? 0 :
255 			rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
256 	}
257 
258 	ifp->if_opackets++;
259 	ifp->if_obytes += m->m_pkthdr.len;
260 #ifdef ALTQ
261 	/*
262 	 * altq for loop is just for debugging.
263 	 * only used when called for loop interface (not for
264 	 * a simplex interface).
265 	 */
266 	if ((ALTQ_IS_ENABLED(&ifp->if_snd) || TBR_IS_ENABLED(&ifp->if_snd))
267 	    && ifp->if_start == lo_altqstart) {
268 		struct altq_pktattr pktattr;
269 		int32_t *afp;
270 	        int error;
271 
272 		/*
273 		 * if the queueing discipline needs packet classification,
274 		 * do it before prepending link headers.
275 		 */
276 		IFQ_CLASSIFY(&ifp->if_snd, m, dst->sa_family, &pktattr);
277 
278 		M_PREPEND(m, sizeof(int32_t), M_DONTWAIT);
279 		if (m == 0)
280 			return(ENOBUFS);
281 		afp = mtod(m, int32_t *);
282 		*afp = (int32_t)dst->sa_family;
283 
284 	        s = splimp();
285 		IFQ_ENQUEUE(&ifp->if_snd, m, &pktattr, error);
286 		(*ifp->if_start)(ifp);
287 		splx(s);
288 		return (error);
289 	}
290 #endif /* ALTQ */
291 	switch (dst->sa_family) {
292 
293 #ifdef INET
294 	case AF_INET:
295 		ifq = &ipintrq;
296 		isr = NETISR_IP;
297 		break;
298 #endif
299 #ifdef INET6
300 	case AF_INET6:
301 		ifq = &ip6intrq;
302 		isr = NETISR_IPV6;
303 		break;
304 #endif /* INET6 */
305 #ifdef NS
306 	case AF_NS:
307 		ifq = &nsintrq;
308 		isr = NETISR_NS;
309 		break;
310 #endif
311 #ifdef IPX
312 	case AF_IPX:
313 		ifq = &ipxintrq;
314 		isr = NETISR_IPX;
315 		break;
316 #endif
317 #ifdef ISO
318 	case AF_ISO:
319 		ifq = &clnlintrq;
320 		isr = NETISR_ISO;
321 		break;
322 #endif
323 #ifdef NETATALK
324 	case AF_APPLETALK:
325 		ifq = &atintrq2;
326 		isr = NETISR_ATALK;
327 		break;
328 #endif /* NETATALK */
329 	default:
330 		printf("%s: can't handle af%d\n", ifp->if_xname,
331 			dst->sa_family);
332 		m_freem(m);
333 		return (EAFNOSUPPORT);
334 	}
335 	s = splimp();
336 	if (IF_QFULL(ifq)) {
337 		IF_DROP(ifq);
338 		m_freem(m);
339 		splx(s);
340 		return (ENOBUFS);
341 	}
342 	IF_ENQUEUE(ifq, m);
343 	schednetisr(isr);
344 	ifp->if_ipackets++;
345 	ifp->if_ibytes += m->m_pkthdr.len;
346 	splx(s);
347 	return (0);
348 }
349 
350 #ifdef ALTQ
351 static void
352 lo_altqstart(ifp)
353 	struct ifnet *ifp;
354 {
355 	struct ifqueue *ifq;
356 	struct mbuf *m;
357 	int32_t af, *afp;
358 	int s, isr;
359 
360 	while (1) {
361 		s = splimp();
362 		IFQ_DEQUEUE(&ifp->if_snd, m);
363 		splx(s);
364 		if (m == NULL)
365 			return;
366 
367 		afp = mtod(m, int32_t *);
368 		af = *afp;
369 		m_adj(m, sizeof(int32_t));
370 
371 		switch (af) {
372 #ifdef INET
373 		case AF_INET:
374 			ifq = &ipintrq;
375 			isr = NETISR_IP;
376 			break;
377 #endif
378 #ifdef INET6
379 		case AF_INET6:
380 			m->m_flags |= M_LOOP;
381 			ifq = &ip6intrq;
382 			isr = NETISR_IPV6;
383 			break;
384 #endif
385 #ifdef IPX
386 		case AF_IPX:
387 			ifq = &ipxintrq;
388 			isr = NETISR_IPX;
389 			break;
390 #endif
391 #ifdef NS
392 		case AF_NS:
393 			ifq = &nsintrq;
394 			isr = NETISR_NS;
395 			break;
396 #endif
397 #ifdef ISO
398 		case AF_ISO:
399 			ifq = &clnlintrq;
400 			isr = NETISR_ISO;
401 			break;
402 #endif
403 #ifdef NETATALK
404 		case AF_APPLETALK:
405 			ifq = &atintrq2;
406 			isr = NETISR_ATALK;
407 			break;
408 #endif /* NETATALK */
409 		default:
410 			printf("lo_altqstart: can't handle af%d\n", af);
411 			m_freem(m);
412 			return;
413 		}
414 
415 		s = splimp();
416 		if (IF_QFULL(ifq)) {
417 			IF_DROP(ifq);
418 			m_freem(m);
419 			splx(s);
420 			return;
421 		}
422 		IF_ENQUEUE(ifq, m);
423 		schednetisr(isr);
424 		ifp->if_ipackets++;
425 		ifp->if_ibytes += m->m_pkthdr.len;
426 		splx(s);
427 	}
428 }
429 #endif /* ALTQ */
430 
431 /* ARGSUSED */
432 void
433 lortrequest(cmd, rt, info)
434 	int cmd;
435 	struct rtentry *rt;
436 	struct rt_addrinfo *info;
437 {
438 
439 	if (rt)
440 		rt->rt_rmx.rmx_mtu = LOMTU;
441 }
442 
443 /*
444  * Process an ioctl request.
445  */
446 /* ARGSUSED */
447 int
448 loioctl(ifp, cmd, data)
449 	register struct ifnet *ifp;
450 	u_long cmd;
451 	caddr_t data;
452 {
453 	register struct ifaddr *ifa;
454 	register struct ifreq *ifr;
455 	register int error = 0;
456 
457 	switch (cmd) {
458 
459 	case SIOCSIFADDR:
460 		ifp->if_flags |= IFF_UP | IFF_RUNNING;
461 		ifa = (struct ifaddr *)data;
462 		if (ifa != 0 /*&& ifa->ifa_addr->sa_family == AF_ISO*/)
463 			ifa->ifa_rtrequest = lortrequest;
464 		/*
465 		 * Everything else is done at a higher level.
466 		 */
467 		break;
468 
469 	case SIOCADDMULTI:
470 	case SIOCDELMULTI:
471 		ifr = (struct ifreq *)data;
472 		if (ifr == 0) {
473 			error = EAFNOSUPPORT;		/* XXX */
474 			break;
475 		}
476 		switch (ifr->ifr_addr.sa_family) {
477 
478 #ifdef INET
479 		case AF_INET:
480 			break;
481 #endif
482 #ifdef INET6
483 		case AF_INET6:
484 			break;
485 #endif /* INET6 */
486 
487 		default:
488 			error = EAFNOSUPPORT;
489 			break;
490 		}
491 		break;
492 
493 	case SIOCSIFMTU:
494 		ifr = (struct ifreq *)data;
495 		ifp->if_mtu = ifr->ifr_mtu;
496 		break;
497 
498 	default:
499 		error = EINVAL;
500 	}
501 	return (error);
502 }
503