xref: /netbsd-src/sys/net/if_loop.c (revision 21e37cc72a480a47828990a439cde7ac9ffaf0c6)
1 /*	$NetBSD: if_loop.c,v 1.50 2004/04/21 18:40:39 itojun Exp $	*/
2 
3 /*
4  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the project nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 /*
33  * Copyright (c) 1982, 1986, 1993
34  *	The Regents of the University of California.  All rights reserved.
35  *
36  * Redistribution and use in source and binary forms, with or without
37  * modification, are permitted provided that the following conditions
38  * are met:
39  * 1. Redistributions of source code must retain the above copyright
40  *    notice, this list of conditions and the following disclaimer.
41  * 2. Redistributions in binary form must reproduce the above copyright
42  *    notice, this list of conditions and the following disclaimer in the
43  *    documentation and/or other materials provided with the distribution.
44  * 3. Neither the name of the University nor the names of its contributors
45  *    may be used to endorse or promote products derived from this software
46  *    without specific prior written permission.
47  *
48  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
49  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
50  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
51  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
52  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
53  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
54  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
55  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
56  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
57  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
58  * SUCH DAMAGE.
59  *
60  *	@(#)if_loop.c	8.2 (Berkeley) 1/9/95
61  */
62 
63 /*
64  * Loopback interface driver for protocol testing and timing.
65  */
66 
67 #include <sys/cdefs.h>
68 __KERNEL_RCSID(0, "$NetBSD: if_loop.c,v 1.50 2004/04/21 18:40:39 itojun Exp $");
69 
70 #include "opt_inet.h"
71 #include "opt_atalk.h"
72 #include "opt_iso.h"
73 #include "opt_ns.h"
74 #include "opt_ipx.h"
75 #include "opt_mbuftrace.h"
76 
77 #include "bpfilter.h"
78 #include "loop.h"
79 
80 #include <sys/param.h>
81 #include <sys/systm.h>
82 #include <sys/kernel.h>
83 #include <sys/mbuf.h>
84 #include <sys/socket.h>
85 #include <sys/errno.h>
86 #include <sys/ioctl.h>
87 #include <sys/time.h>
88 
89 #include <machine/cpu.h>
90 
91 #include <net/if.h>
92 #include <net/if_types.h>
93 #include <net/netisr.h>
94 #include <net/route.h>
95 
96 #ifdef	INET
97 #include <netinet/in.h>
98 #include <netinet/in_systm.h>
99 #include <netinet/in_var.h>
100 #include <netinet/ip.h>
101 #endif
102 
103 #ifdef INET6
104 #ifndef INET
105 #include <netinet/in.h>
106 #endif
107 #include <netinet6/in6_var.h>
108 #include <netinet/ip6.h>
109 #endif
110 
111 #ifdef NS
112 #include <netns/ns.h>
113 #include <netns/ns_if.h>
114 #endif
115 
116 #ifdef IPX
117 #include <netipx/ipx.h>
118 #include <netipx/ipx_if.h>
119 #endif
120 
121 #ifdef ISO
122 #include <netiso/iso.h>
123 #include <netiso/iso_var.h>
124 #endif
125 
126 #ifdef NETATALK
127 #include <netatalk/at.h>
128 #include <netatalk/at_var.h>
129 #endif
130 
131 #if NBPFILTER > 0
132 #include <net/bpf.h>
133 #endif
134 
135 #if defined(LARGE_LOMTU)
136 #define LOMTU	(131072 +  MHLEN + MLEN)
137 #define LOMTU_MAX LOMTU
138 #else
139 #define	LOMTU	(32768 +  MHLEN + MLEN)
140 #define	LOMTU_MAX	(65536 +  MHLEN + MLEN)
141 #endif
142 
143 struct	ifnet loif[NLOOP];
144 #ifdef MBUFTRACE
145 struct	mowner lomowner[NLOOP];
146 #endif
147 
148 #ifdef ALTQ
149 void	lostart(struct ifnet *);
150 #endif
151 
152 void
153 loopattach(n)
154 	int n;
155 {
156 	int i;
157 	struct ifnet *ifp;
158 
159 	for (i = 0; i < NLOOP; i++) {
160 		ifp = &loif[i];
161 		snprintf(ifp->if_xname, sizeof(ifp->if_xname), "lo%d", i);
162 		ifp->if_softc = NULL;
163 		ifp->if_mtu = LOMTU;
164 		ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST;
165 		ifp->if_ioctl = loioctl;
166 		ifp->if_output = looutput;
167 #ifdef ALTQ
168 		ifp->if_start = lostart;
169 #endif
170 		ifp->if_type = IFT_LOOP;
171 		ifp->if_hdrlen = 0;
172 		ifp->if_addrlen = 0;
173 		ifp->if_dlt = DLT_NULL;
174 		IFQ_SET_READY(&ifp->if_snd);
175 		if_attach(ifp);
176 		if_alloc_sadl(ifp);
177 #if NBPFILTER > 0
178 		bpfattach(ifp, DLT_NULL, sizeof(u_int));
179 #endif
180 #ifdef MBUFTRACE
181 		ifp->if_mowner = &lomowner[i];
182 		strlcpy(ifp->if_mowner->mo_name, ifp->if_xname,
183 		    sizeof(ifp->if_mowner->mo_name));
184 		MOWNER_ATTACH(&lomowner[i]);
185 #endif
186 	}
187 }
188 
189 int
190 looutput(ifp, m, dst, rt)
191 	struct ifnet *ifp;
192 	struct mbuf *m;
193 	struct sockaddr *dst;
194 	struct rtentry *rt;
195 {
196 	int s, isr;
197 	struct ifqueue *ifq = 0;
198 
199 	MCLAIM(m, ifp->if_mowner);
200 	if ((m->m_flags & M_PKTHDR) == 0)
201 		panic("looutput: no header mbuf");
202 #if NBPFILTER > 0
203 	if (ifp->if_bpf && (ifp->if_flags & IFF_LOOPBACK)) {
204 		/*
205 		 * We need to prepend the address family as
206 		 * a four byte field.  Cons up a dummy header
207 		 * to pacify bpf.  This is safe because bpf
208 		 * will only read from the mbuf (i.e., it won't
209 		 * try to free it or keep a pointer to it).
210 		 */
211 		struct mbuf m0;
212 		u_int32_t af = dst->sa_family;
213 
214 		m0.m_flags = 0;
215 		m0.m_next = m;
216 		m0.m_len = 4;
217 		m0.m_data = (char *)&af;
218 
219 		bpf_mtap(ifp->if_bpf, &m0);
220 	}
221 #endif
222 	m->m_pkthdr.rcvif = ifp;
223 
224 	if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
225 		m_freem(m);
226 		return (rt->rt_flags & RTF_BLACKHOLE ? 0 :
227 			rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
228 	}
229 
230 	ifp->if_opackets++;
231 	ifp->if_obytes += m->m_pkthdr.len;
232 
233 #ifdef ALTQ
234 	/*
235 	 * ALTQ on the loopback interface is just for debugging.  It's
236 	 * used only for loopback interfaces, not for a simplex interface.
237 	 */
238 	if ((ALTQ_IS_ENABLED(&ifp->if_snd) || TBR_IS_ENABLED(&ifp->if_snd)) &&
239 	    ifp->if_start == lostart) {
240 		struct altq_pktattr pktattr;
241 		int error;
242 
243 		/*
244 		 * If the queueing discipline needs packet classification,
245 		 * do it before prepending the link headers.
246 		 */
247 		IFQ_CLASSIFY(&ifp->if_snd, m, dst->sa_family, &pktattr);
248 
249 		M_PREPEND(m, sizeof(uint32_t), M_DONTWAIT);
250 		if (m == NULL)
251 			return (ENOBUFS);
252 		*(mtod(m, uint32_t *)) = dst->sa_family;
253 
254 		s = splnet();
255 		IFQ_ENQUEUE(&ifp->if_snd, m, &pktattr, error);
256 		(*ifp->if_start)(ifp);
257 		splx(s);
258 		return (error);
259 	}
260 #endif /* ALTQ */
261 
262 	m_tag_delete_nonpersistent(m);
263 
264 	switch (dst->sa_family) {
265 
266 #ifdef INET
267 	case AF_INET:
268 		ifq = &ipintrq;
269 		isr = NETISR_IP;
270 		break;
271 #endif
272 #ifdef INET6
273 	case AF_INET6:
274 		m->m_flags |= M_LOOP;
275 		ifq = &ip6intrq;
276 		isr = NETISR_IPV6;
277 		break;
278 #endif
279 #ifdef NS
280 	case AF_NS:
281 		ifq = &nsintrq;
282 		isr = NETISR_NS;
283 		break;
284 #endif
285 #ifdef ISO
286 	case AF_ISO:
287 		ifq = &clnlintrq;
288 		isr = NETISR_ISO;
289 		break;
290 #endif
291 #ifdef IPX
292 	case AF_IPX:
293 		ifq = &ipxintrq;
294 		isr = NETISR_IPX;
295 		break;
296 #endif
297 #ifdef NETATALK
298 	case AF_APPLETALK:
299 	        ifq = &atintrq2;
300 		isr = NETISR_ATALK;
301 		break;
302 #endif
303 	default:
304 		printf("%s: can't handle af%d\n", ifp->if_xname,
305 		    dst->sa_family);
306 		m_freem(m);
307 		return (EAFNOSUPPORT);
308 	}
309 	s = splnet();
310 	if (IF_QFULL(ifq)) {
311 		IF_DROP(ifq);
312 		m_freem(m);
313 		splx(s);
314 		return (ENOBUFS);
315 	}
316 	IF_ENQUEUE(ifq, m);
317 	schednetisr(isr);
318 	ifp->if_ipackets++;
319 	ifp->if_ibytes += m->m_pkthdr.len;
320 	splx(s);
321 	return (0);
322 }
323 
324 #ifdef ALTQ
325 void
326 lostart(struct ifnet *ifp)
327 {
328 	struct ifqueue *ifq;
329 	struct mbuf *m;
330 	uint32_t af;
331 	int s, isr;
332 
333 	for (;;) {
334 		IFQ_DEQUEUE(&ifp->if_snd, m);
335 		if (m == NULL)
336 			return;
337 
338 		af = *(mtod(m, uint32_t *));
339 		m_adj(m, sizeof(uint32_t));
340 
341 		switch (af) {
342 #ifdef INET
343 		case AF_INET:
344 			ifq = &ipintrq;
345 			isr = NETISR_IP;
346 			break;
347 #endif
348 #ifdef INET6
349 		case AF_INET6:
350 			m->m_flags |= M_LOOP;
351 			ifq = &ip6intrq;
352 			isr = NETISR_IPV6;
353 			break;
354 #endif
355 #ifdef IPX
356 		case AF_IPX:
357 			ifq = &ipxintrq;
358 			isr = NETISR_IPX;
359 			break;
360 #endif
361 #ifdef NS
362 		case AF_NS:
363 			ifq = &nsintrq;
364 			isr = NETISR_NS;
365 			break;
366 #endif
367 #ifdef ISO
368 		case AF_ISO:
369 			ifq = &clnlintrq;
370 			isr = NETISR_ISO;
371 			break;
372 #endif
373 #ifdef NETATALK
374 		case AF_APPLETALK:
375 			ifq = &atintrq2;
376 			isr = NETISR_ATALK;
377 			break;
378 #endif
379 		default:
380 			printf("%s: can't handle af%d\n", ifp->if_xname, af);
381 			m_freem(m);
382 			return;
383 		}
384 
385 		s = splnet();
386 		if (IF_QFULL(ifq)) {
387 			IF_DROP(ifq);
388 			splx(s);
389 			m_freem(m);
390 			return;
391 		}
392 		IF_ENQUEUE(ifq, m);
393 		schednetisr(isr);
394 		ifp->if_ipackets++;
395 		ifp->if_ibytes += m->m_pkthdr.len;
396 		splx(s);
397 	}
398 }
399 #endif /* ALTQ */
400 
401 /* ARGSUSED */
402 void
403 lortrequest(cmd, rt, info)
404 	int cmd;
405 	struct rtentry *rt;
406 	struct rt_addrinfo *info;
407 {
408 
409 	struct ifnet *ifp = &loif[0];
410 	if (rt)
411 		rt->rt_rmx.rmx_mtu = ifp->if_mtu;
412 
413 }
414 
415 /*
416  * Process an ioctl request.
417  */
418 /* ARGSUSED */
419 int
420 loioctl(ifp, cmd, data)
421 	struct ifnet *ifp;
422 	u_long cmd;
423 	caddr_t data;
424 {
425 	struct ifaddr *ifa;
426 	struct ifreq *ifr;
427 	int error = 0;
428 
429 	switch (cmd) {
430 
431 	case SIOCSIFADDR:
432 		ifp->if_flags |= IFF_UP;
433 		ifa = (struct ifaddr *)data;
434 		if (ifa != 0 /*&& ifa->ifa_addr->sa_family == AF_ISO*/)
435 			ifa->ifa_rtrequest = lortrequest;
436 		/*
437 		 * Everything else is done at a higher level.
438 		 */
439 		break;
440 
441 	case SIOCSIFMTU:
442 		ifr = (struct ifreq *)data;
443 		if ((unsigned)ifr->ifr_mtu > LOMTU_MAX)
444 			error = EINVAL;
445 		else {
446 			/* XXX update rt mtu for AF_ISO? */
447 			ifp->if_mtu = ifr->ifr_mtu;
448 		}
449 		break;
450 
451 	case SIOCADDMULTI:
452 	case SIOCDELMULTI:
453 		ifr = (struct ifreq *)data;
454 		if (ifr == 0) {
455 			error = EAFNOSUPPORT;		/* XXX */
456 			break;
457 		}
458 		switch (ifr->ifr_addr.sa_family) {
459 
460 #ifdef INET
461 		case AF_INET:
462 			break;
463 #endif
464 #ifdef INET6
465 		case AF_INET6:
466 			break;
467 #endif
468 
469 		default:
470 			error = EAFNOSUPPORT;
471 			break;
472 		}
473 		break;
474 
475 	default:
476 		error = EINVAL;
477 	}
478 	return (error);
479 }
480