xref: /netbsd-src/sys/net/if_loop.c (revision 8b0f9554ff8762542c4defc4f70e1eb76fb508fa)
1 /*	$NetBSD: if_loop.c,v 1.66 2007/10/19 12:16:44 ad 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 1.66 2007/10/19 12:16:44 ad 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 <sys/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 static int	loop_clone_create(struct if_clone *, int);
142 static int	loop_clone_destroy(struct ifnet *);
143 
144 static struct if_clone loop_cloner =
145     IF_CLONE_INITIALIZER("lo", loop_clone_create, loop_clone_destroy);
146 
147 void
148 loopattach(int n)
149 {
150 
151 	(void)loop_clone_create(&loop_cloner, 0);	/* lo0 always exists */
152 	if_clone_attach(&loop_cloner);
153 }
154 
155 static int
156 loop_clone_create(struct if_clone *ifc, int unit)
157 {
158 	struct ifnet *ifp;
159 
160 	ifp = malloc(sizeof(*ifp), M_DEVBUF, M_WAITOK | M_ZERO);
161 
162 	snprintf(ifp->if_xname, sizeof(ifp->if_xname), "%s%d",
163 	    ifc->ifc_name, unit);
164 
165 	ifp->if_mtu = LOMTU;
166 	ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST | IFF_RUNNING;
167 	ifp->if_ioctl = loioctl;
168 	ifp->if_output = looutput;
169 #ifdef ALTQ
170 	ifp->if_start = lostart;
171 #endif
172 	ifp->if_type = IFT_LOOP;
173 	ifp->if_hdrlen = 0;
174 	ifp->if_addrlen = 0;
175 	ifp->if_dlt = DLT_NULL;
176 	IFQ_SET_READY(&ifp->if_snd);
177 	if (unit == 0)
178 		lo0ifp = ifp;
179 	if_attach(ifp);
180 	if_alloc_sadl(ifp);
181 #if NBPFILTER > 0
182 	bpfattach(ifp, DLT_NULL, sizeof(u_int));
183 #endif
184 #ifdef MBUFTRACE
185 	ifp->if_mowner = malloc(sizeof(struct mowner), M_DEVBUF,
186 	    M_WAITOK | M_ZERO);
187 	strlcpy(ifp->if_mowner->mo_name, ifp->if_xname,
188 	    sizeof(ifp->if_mowner->mo_name));
189 	MOWNER_ATTACH(ifp->if_mowner);
190 #endif
191 
192 	return (0);
193 }
194 
195 static int
196 loop_clone_destroy(struct ifnet *ifp)
197 {
198 
199 	if (ifp == lo0ifp)
200 		return (EPERM);
201 
202 #ifdef MBUFTRACE
203 	MOWNER_DETACH(ifp->if_mowner);
204 	free(ifp->if_mowner, M_DEVBUF);
205 #endif
206 
207 #if NBPFILTER > 0
208 	bpfdetach(ifp);
209 #endif
210 	if_detach(ifp);
211 
212 	free(ifp, M_DEVBUF);
213 
214 	return (0);
215 }
216 
217 int
218 looutput(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
219     struct rtentry *rt)
220 {
221 	int s, isr;
222 	struct ifqueue *ifq = NULL;
223 
224 	MCLAIM(m, ifp->if_mowner);
225 	if ((m->m_flags & M_PKTHDR) == 0)
226 		panic("looutput: no header mbuf");
227 #if NBPFILTER > 0
228 	if (ifp->if_bpf && (ifp->if_flags & IFF_LOOPBACK))
229 		bpf_mtap_af(ifp->if_bpf, dst->sa_family, m);
230 #endif
231 	m->m_pkthdr.rcvif = ifp;
232 
233 	if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
234 		m_freem(m);
235 		return (rt->rt_flags & RTF_BLACKHOLE ? 0 :
236 			rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
237 	}
238 
239 	ifp->if_opackets++;
240 	ifp->if_obytes += m->m_pkthdr.len;
241 
242 #ifdef ALTQ
243 	/*
244 	 * ALTQ on the loopback interface is just for debugging.  It's
245 	 * used only for loopback interfaces, not for a simplex interface.
246 	 */
247 	if ((ALTQ_IS_ENABLED(&ifp->if_snd) || TBR_IS_ENABLED(&ifp->if_snd)) &&
248 	    ifp->if_start == lostart) {
249 		struct altq_pktattr pktattr;
250 		int error;
251 
252 		/*
253 		 * If the queueing discipline needs packet classification,
254 		 * do it before prepending the link headers.
255 		 */
256 		IFQ_CLASSIFY(&ifp->if_snd, m, dst->sa_family, &pktattr);
257 
258 		M_PREPEND(m, sizeof(uint32_t), M_DONTWAIT);
259 		if (m == NULL)
260 			return (ENOBUFS);
261 		*(mtod(m, uint32_t *)) = dst->sa_family;
262 
263 		s = splnet();
264 		IFQ_ENQUEUE(&ifp->if_snd, m, &pktattr, error);
265 		(*ifp->if_start)(ifp);
266 		splx(s);
267 		return (error);
268 	}
269 #endif /* ALTQ */
270 
271 	m_tag_delete_nonpersistent(m);
272 
273 	switch (dst->sa_family) {
274 
275 #ifdef INET
276 	case AF_INET:
277 		ifq = &ipintrq;
278 		isr = NETISR_IP;
279 		break;
280 #endif
281 #ifdef INET6
282 	case AF_INET6:
283 		m->m_flags |= M_LOOP;
284 		ifq = &ip6intrq;
285 		isr = NETISR_IPV6;
286 		break;
287 #endif
288 #ifdef ISO
289 	case AF_ISO:
290 		ifq = &clnlintrq;
291 		isr = NETISR_ISO;
292 		break;
293 #endif
294 #ifdef IPX
295 	case AF_IPX:
296 		ifq = &ipxintrq;
297 		isr = NETISR_IPX;
298 		break;
299 #endif
300 #ifdef NETATALK
301 	case AF_APPLETALK:
302 	        ifq = &atintrq2;
303 		isr = NETISR_ATALK;
304 		break;
305 #endif
306 	default:
307 		printf("%s: can't handle af%d\n", ifp->if_xname,
308 		    dst->sa_family);
309 		m_freem(m);
310 		return (EAFNOSUPPORT);
311 	}
312 	s = splnet();
313 	if (IF_QFULL(ifq)) {
314 		IF_DROP(ifq);
315 		m_freem(m);
316 		splx(s);
317 		return (ENOBUFS);
318 	}
319 	IF_ENQUEUE(ifq, m);
320 	schednetisr(isr);
321 	ifp->if_ipackets++;
322 	ifp->if_ibytes += m->m_pkthdr.len;
323 	splx(s);
324 	return (0);
325 }
326 
327 #ifdef ALTQ
328 static void
329 lostart(struct ifnet *ifp)
330 {
331 	struct ifqueue *ifq;
332 	struct mbuf *m;
333 	uint32_t af;
334 	int s, isr;
335 
336 	for (;;) {
337 		IFQ_DEQUEUE(&ifp->if_snd, m);
338 		if (m == NULL)
339 			return;
340 
341 		af = *(mtod(m, uint32_t *));
342 		m_adj(m, sizeof(uint32_t));
343 
344 		switch (af) {
345 #ifdef INET
346 		case AF_INET:
347 			ifq = &ipintrq;
348 			isr = NETISR_IP;
349 			break;
350 #endif
351 #ifdef INET6
352 		case AF_INET6:
353 			m->m_flags |= M_LOOP;
354 			ifq = &ip6intrq;
355 			isr = NETISR_IPV6;
356 			break;
357 #endif
358 #ifdef IPX
359 		case AF_IPX:
360 			ifq = &ipxintrq;
361 			isr = NETISR_IPX;
362 			break;
363 #endif
364 #ifdef ISO
365 		case AF_ISO:
366 			ifq = &clnlintrq;
367 			isr = NETISR_ISO;
368 			break;
369 #endif
370 #ifdef NETATALK
371 		case AF_APPLETALK:
372 			ifq = &atintrq2;
373 			isr = NETISR_ATALK;
374 			break;
375 #endif
376 		default:
377 			printf("%s: can't handle af%d\n", ifp->if_xname, af);
378 			m_freem(m);
379 			return;
380 		}
381 
382 		s = splnet();
383 		if (IF_QFULL(ifq)) {
384 			IF_DROP(ifq);
385 			splx(s);
386 			m_freem(m);
387 			return;
388 		}
389 		IF_ENQUEUE(ifq, m);
390 		schednetisr(isr);
391 		ifp->if_ipackets++;
392 		ifp->if_ibytes += m->m_pkthdr.len;
393 		splx(s);
394 	}
395 }
396 #endif /* ALTQ */
397 
398 /* ARGSUSED */
399 void
400 lortrequest(int cmd, struct rtentry *rt,
401     struct rt_addrinfo *info)
402 {
403 
404 	if (rt)
405 		rt->rt_rmx.rmx_mtu = lo0ifp->if_mtu;
406 }
407 
408 /*
409  * Process an ioctl request.
410  */
411 /* ARGSUSED */
412 int
413 loioctl(struct ifnet *ifp, u_long cmd, void *data)
414 {
415 	struct ifaddr *ifa;
416 	struct ifreq *ifr;
417 	int error = 0;
418 
419 	switch (cmd) {
420 
421 	case SIOCSIFADDR:
422 		ifp->if_flags |= IFF_UP;
423 		ifa = (struct ifaddr *)data;
424 		if (ifa != NULL /*&& ifa->ifa_addr->sa_family == AF_ISO*/)
425 			ifa->ifa_rtrequest = lortrequest;
426 		/*
427 		 * Everything else is done at a higher level.
428 		 */
429 		break;
430 
431 	case SIOCSIFMTU:
432 		ifr = (struct ifreq *)data;
433 		if ((unsigned)ifr->ifr_mtu > LOMTU_MAX)
434 			error = EINVAL;
435 		else {
436 			/* XXX update rt mtu for AF_ISO? */
437 			ifp->if_mtu = ifr->ifr_mtu;
438 		}
439 		break;
440 
441 	case SIOCADDMULTI:
442 	case SIOCDELMULTI:
443 		ifr = (struct ifreq *)data;
444 		if (ifr == NULL) {
445 			error = EAFNOSUPPORT;		/* XXX */
446 			break;
447 		}
448 		switch (ifreq_getaddr(cmd, ifr)->sa_family) {
449 
450 #ifdef INET
451 		case AF_INET:
452 			break;
453 #endif
454 #ifdef INET6
455 		case AF_INET6:
456 			break;
457 #endif
458 
459 		default:
460 			error = EAFNOSUPPORT;
461 			break;
462 		}
463 		break;
464 
465 	default:
466 		error = EINVAL;
467 	}
468 	return (error);
469 }
470