xref: /netbsd-src/sys/net/if_loop.c (revision 1921cb5602567cfc8401cc953be22fe9d74238f2)
1 /*	$NetBSD: if_loop.c,v 1.58 2006/09/07 02:40:33 dogcow 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 1.58 2006/09/07 02:40:33 dogcow Exp $");
69 
70 #include "opt_inet.h"
71 #include "opt_atalk.h"
72 #include "opt_iso.h"
73 #include "opt_ipx.h"
74 #include "opt_mbuftrace.h"
75 
76 #include "bpfilter.h"
77 
78 #include <sys/param.h>
79 #include <sys/systm.h>
80 #include <sys/kernel.h>
81 #include <sys/mbuf.h>
82 #include <sys/socket.h>
83 #include <sys/errno.h>
84 #include <sys/ioctl.h>
85 #include <sys/time.h>
86 
87 #include <machine/cpu.h>
88 
89 #include <net/if.h>
90 #include <net/if_types.h>
91 #include <net/netisr.h>
92 #include <net/route.h>
93 
94 #ifdef	INET
95 #include <netinet/in.h>
96 #include <netinet/in_systm.h>
97 #include <netinet/in_var.h>
98 #include <netinet/ip.h>
99 #endif
100 
101 #ifdef INET6
102 #ifndef INET
103 #include <netinet/in.h>
104 #endif
105 #include <netinet6/in6_var.h>
106 #include <netinet/ip6.h>
107 #endif
108 
109 
110 #ifdef IPX
111 #include <netipx/ipx.h>
112 #include <netipx/ipx_if.h>
113 #endif
114 
115 #ifdef ISO
116 #include <netiso/iso.h>
117 #include <netiso/iso_var.h>
118 #endif
119 
120 #ifdef NETATALK
121 #include <netatalk/at.h>
122 #include <netatalk/at_var.h>
123 #endif
124 
125 #if NBPFILTER > 0
126 #include <net/bpf.h>
127 #endif
128 
129 #if defined(LARGE_LOMTU)
130 #define LOMTU	(131072 +  MHLEN + MLEN)
131 #define LOMTU_MAX LOMTU
132 #else
133 #define	LOMTU	(32768 +  MHLEN + MLEN)
134 #define	LOMTU_MAX	(65536 +  MHLEN + MLEN)
135 #endif
136 
137 #ifdef ALTQ
138 static void	lostart(struct ifnet *);
139 #endif
140 
141 struct loop_softc {
142 	LIST_ENTRY(loop_softc) sc_list;
143 	struct ifnet sc_if;
144 };
145 
146 static LIST_HEAD(, loop_softc) loop_softc_list;
147 
148 static int	loop_clone_create(struct if_clone *, int);
149 static int	loop_clone_destroy(struct ifnet *);
150 
151 static struct if_clone loop_cloner =
152     IF_CLONE_INITIALIZER("lo", loop_clone_create, loop_clone_destroy);
153 
154 void
155 loopattach(int n)
156 {
157 	LIST_INIT(&loop_softc_list);
158 
159 	(void)loop_clone_create(&loop_cloner, 0);	/* lo0 always exists */
160 	if_clone_attach(&loop_cloner);
161 }
162 
163 static int
164 loop_clone_create(struct if_clone *ifc, int unit)
165 {
166 	struct loop_softc *sc;
167 
168 	sc = malloc(sizeof(struct loop_softc), M_DEVBUF, M_WAITOK | M_ZERO);
169 
170 	snprintf(sc->sc_if.if_xname, sizeof(sc->sc_if.if_xname), "%s%d",
171 	    ifc->ifc_name, unit);
172 
173 	sc->sc_if.if_softc = sc;
174 	sc->sc_if.if_mtu = LOMTU;
175 	sc->sc_if.if_flags = IFF_LOOPBACK | IFF_MULTICAST;
176 	sc->sc_if.if_ioctl = loioctl;
177 	sc->sc_if.if_output = looutput;
178 #ifdef ALTQ
179 	sc->sc_if.if_start = lostart;
180 #endif
181 	sc->sc_if.if_type = IFT_LOOP;
182 	sc->sc_if.if_hdrlen = 0;
183 	sc->sc_if.if_addrlen = 0;
184 	sc->sc_if.if_dlt = DLT_NULL;
185 	IFQ_SET_READY(&sc->sc_if.if_snd);
186 	if (unit == 0)
187 		lo0ifp = &sc->sc_if;
188 	if_attach(&sc->sc_if);
189 	if_alloc_sadl(&sc->sc_if);
190 #if NBPFILTER > 0
191 	bpfattach(&sc->sc_if, DLT_NULL, sizeof(u_int));
192 #endif
193 #ifdef MBUFTRACE
194 	sc->sc_if.if_mowner = malloc(sizeof(struct mowner), M_DEVBUF,
195 	    M_WAITOK | M_ZERO);
196 	strlcpy(sc->sc_if.if_mowner->mo_name, sc->sc_if.if_xname,
197 	    sizeof(sc->sc_if.if_mowner->mo_name));
198 	MOWNER_ATTACH(sc->sc_if.if_mowner);
199 #endif
200 	LIST_INSERT_HEAD(&loop_softc_list, sc, sc_list);
201 
202 	return (0);
203 }
204 
205 static int
206 loop_clone_destroy(struct ifnet *ifp)
207 {
208 	struct loop_softc *sc = ifp->if_softc;
209 
210 	if (ifp == lo0ifp)
211 		return (EPERM);
212 
213 #ifdef MBUFTRACE
214 	MOWNER_DETACH(ifp->if_mowner);
215 	free(ifp->if_mowner, M_DEVBUF);
216 #endif
217 
218 #if NBPFILTER > 0
219 	bpfdetach(ifp);
220 #endif
221 	if_detach(ifp);
222 
223 	LIST_REMOVE(sc, sc_list);
224 	free(sc, M_DEVBUF);
225 
226 	return (0);
227 }
228 
229 int
230 looutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
231     struct rtentry *rt)
232 {
233 	int s, isr;
234 	struct ifqueue *ifq = NULL;
235 
236 	MCLAIM(m, ifp->if_mowner);
237 	if ((m->m_flags & M_PKTHDR) == 0)
238 		panic("looutput: no header mbuf");
239 #if NBPFILTER > 0
240 	if (ifp->if_bpf && (ifp->if_flags & IFF_LOOPBACK))
241 		bpf_mtap_af(ifp->if_bpf, dst->sa_family, m);
242 #endif
243 	m->m_pkthdr.rcvif = ifp;
244 
245 	if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
246 		m_freem(m);
247 		return (rt->rt_flags & RTF_BLACKHOLE ? 0 :
248 			rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
249 	}
250 
251 	ifp->if_opackets++;
252 	ifp->if_obytes += m->m_pkthdr.len;
253 
254 #ifdef ALTQ
255 	/*
256 	 * ALTQ on the loopback interface is just for debugging.  It's
257 	 * used only for loopback interfaces, not for a simplex interface.
258 	 */
259 	if ((ALTQ_IS_ENABLED(&ifp->if_snd) || TBR_IS_ENABLED(&ifp->if_snd)) &&
260 	    ifp->if_start == lostart) {
261 		struct altq_pktattr pktattr;
262 		int error;
263 
264 		/*
265 		 * If the queueing discipline needs packet classification,
266 		 * do it before prepending the link headers.
267 		 */
268 		IFQ_CLASSIFY(&ifp->if_snd, m, dst->sa_family, &pktattr);
269 
270 		M_PREPEND(m, sizeof(uint32_t), M_DONTWAIT);
271 		if (m == NULL)
272 			return (ENOBUFS);
273 		*(mtod(m, uint32_t *)) = dst->sa_family;
274 
275 		s = splnet();
276 		IFQ_ENQUEUE(&ifp->if_snd, m, &pktattr, error);
277 		(*ifp->if_start)(ifp);
278 		splx(s);
279 		return (error);
280 	}
281 #endif /* ALTQ */
282 
283 	m_tag_delete_nonpersistent(m);
284 
285 	switch (dst->sa_family) {
286 
287 #ifdef INET
288 	case AF_INET:
289 		ifq = &ipintrq;
290 		isr = NETISR_IP;
291 		break;
292 #endif
293 #ifdef INET6
294 	case AF_INET6:
295 		m->m_flags |= M_LOOP;
296 		ifq = &ip6intrq;
297 		isr = NETISR_IPV6;
298 		break;
299 #endif
300 #ifdef ISO
301 	case AF_ISO:
302 		ifq = &clnlintrq;
303 		isr = NETISR_ISO;
304 		break;
305 #endif
306 #ifdef IPX
307 	case AF_IPX:
308 		ifq = &ipxintrq;
309 		isr = NETISR_IPX;
310 		break;
311 #endif
312 #ifdef NETATALK
313 	case AF_APPLETALK:
314 	        ifq = &atintrq2;
315 		isr = NETISR_ATALK;
316 		break;
317 #endif
318 	default:
319 		printf("%s: can't handle af%d\n", ifp->if_xname,
320 		    dst->sa_family);
321 		m_freem(m);
322 		return (EAFNOSUPPORT);
323 	}
324 	s = splnet();
325 	if (IF_QFULL(ifq)) {
326 		IF_DROP(ifq);
327 		m_freem(m);
328 		splx(s);
329 		return (ENOBUFS);
330 	}
331 	IF_ENQUEUE(ifq, m);
332 	schednetisr(isr);
333 	ifp->if_ipackets++;
334 	ifp->if_ibytes += m->m_pkthdr.len;
335 	splx(s);
336 	return (0);
337 }
338 
339 #ifdef ALTQ
340 static void
341 lostart(struct ifnet *ifp)
342 {
343 	struct ifqueue *ifq;
344 	struct mbuf *m;
345 	uint32_t af;
346 	int s, isr;
347 
348 	for (;;) {
349 		IFQ_DEQUEUE(&ifp->if_snd, m);
350 		if (m == NULL)
351 			return;
352 
353 		af = *(mtod(m, uint32_t *));
354 		m_adj(m, sizeof(uint32_t));
355 
356 		switch (af) {
357 #ifdef INET
358 		case AF_INET:
359 			ifq = &ipintrq;
360 			isr = NETISR_IP;
361 			break;
362 #endif
363 #ifdef INET6
364 		case AF_INET6:
365 			m->m_flags |= M_LOOP;
366 			ifq = &ip6intrq;
367 			isr = NETISR_IPV6;
368 			break;
369 #endif
370 #ifdef IPX
371 		case AF_IPX:
372 			ifq = &ipxintrq;
373 			isr = NETISR_IPX;
374 			break;
375 #endif
376 #ifdef ISO
377 		case AF_ISO:
378 			ifq = &clnlintrq;
379 			isr = NETISR_ISO;
380 			break;
381 #endif
382 #ifdef NETATALK
383 		case AF_APPLETALK:
384 			ifq = &atintrq2;
385 			isr = NETISR_ATALK;
386 			break;
387 #endif
388 		default:
389 			printf("%s: can't handle af%d\n", ifp->if_xname, af);
390 			m_freem(m);
391 			return;
392 		}
393 
394 		s = splnet();
395 		if (IF_QFULL(ifq)) {
396 			IF_DROP(ifq);
397 			splx(s);
398 			m_freem(m);
399 			return;
400 		}
401 		IF_ENQUEUE(ifq, m);
402 		schednetisr(isr);
403 		ifp->if_ipackets++;
404 		ifp->if_ibytes += m->m_pkthdr.len;
405 		splx(s);
406 	}
407 }
408 #endif /* ALTQ */
409 
410 /* ARGSUSED */
411 void
412 lortrequest(int cmd, struct rtentry *rt, struct rt_addrinfo *info)
413 {
414 
415 	if (rt)
416 		rt->rt_rmx.rmx_mtu = lo0ifp->if_mtu;
417 }
418 
419 /*
420  * Process an ioctl request.
421  */
422 /* ARGSUSED */
423 int
424 loioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
425 {
426 	struct ifaddr *ifa;
427 	struct ifreq *ifr;
428 	int error = 0;
429 
430 	switch (cmd) {
431 
432 	case SIOCSIFADDR:
433 		ifp->if_flags |= IFF_UP;
434 		ifa = (struct ifaddr *)data;
435 		if (ifa != NULL /*&& ifa->ifa_addr->sa_family == AF_ISO*/)
436 			ifa->ifa_rtrequest = lortrequest;
437 		/*
438 		 * Everything else is done at a higher level.
439 		 */
440 		break;
441 
442 	case SIOCSIFMTU:
443 		ifr = (struct ifreq *)data;
444 		if ((unsigned)ifr->ifr_mtu > LOMTU_MAX)
445 			error = EINVAL;
446 		else {
447 			/* XXX update rt mtu for AF_ISO? */
448 			ifp->if_mtu = ifr->ifr_mtu;
449 		}
450 		break;
451 
452 	case SIOCADDMULTI:
453 	case SIOCDELMULTI:
454 		ifr = (struct ifreq *)data;
455 		if (ifr == NULL) {
456 			error = EAFNOSUPPORT;		/* XXX */
457 			break;
458 		}
459 		switch (ifr->ifr_addr.sa_family) {
460 
461 #ifdef INET
462 		case AF_INET:
463 			break;
464 #endif
465 #ifdef INET6
466 		case AF_INET6:
467 			break;
468 #endif
469 
470 		default:
471 			error = EAFNOSUPPORT;
472 			break;
473 		}
474 		break;
475 
476 	default:
477 		error = EINVAL;
478 	}
479 	return (error);
480 }
481