xref: /netbsd-src/sys/net/if_loop.c (revision d25ffa98a4bfca1fe272f3c182496ec9934faac7) 
1 /*	$NetBSD: if_loop.c,v 1.74 2011/06/17 09:15:24 kefren 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 1.74 2011/06/17 09:15:24 kefren 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 #include "opt_mpls.h"
76 
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/in_offload.h>
99 #include <netinet/ip.h>
100 #endif
101 
102 #ifdef INET6
103 #ifndef INET
104 #include <netinet/in.h>
105 #endif
106 #include <netinet6/in6_var.h>
107 #include <netinet6/in6_offload.h>
108 #include <netinet/ip6.h>
109 #endif
110 
111 #ifdef IPX
112 #include <netipx/ipx.h>
113 #include <netipx/ipx_if.h>
114 #endif
115 
116 #ifdef ISO
117 #include <netiso/iso.h>
118 #include <netiso/iso_var.h>
119 #endif
120 
121 #ifdef MPLS
122 #include <netmpls/mpls.h>
123 #include <netmpls/mpls_var.h>
124 #endif
125 
126 #ifdef NETATALK
127 #include <netatalk/at.h>
128 #include <netatalk/at_var.h>
129 #endif
130 
131 #include <net/bpf.h>
132 
133 #if defined(LARGE_LOMTU)
134 #define LOMTU	(131072 +  MHLEN + MLEN)
135 #define LOMTU_MAX LOMTU
136 #else
137 #define	LOMTU	(32768 +  MHLEN + MLEN)
138 #define	LOMTU_MAX	(65536 +  MHLEN + MLEN)
139 #endif
140 
141 #ifdef ALTQ
142 static void	lostart(struct ifnet *);
143 #endif
144 
145 static int	loop_clone_create(struct if_clone *, int);
146 static int	loop_clone_destroy(struct ifnet *);
147 
148 static struct if_clone loop_cloner =
149     IF_CLONE_INITIALIZER("lo", loop_clone_create, loop_clone_destroy);
150 
151 void
152 loopattach(int n)
153 {
154 
155 	(void)loop_clone_create(&loop_cloner, 0);	/* lo0 always exists */
156 	if_clone_attach(&loop_cloner);
157 }
158 
159 static int
160 loop_clone_create(struct if_clone *ifc, int unit)
161 {
162 	struct ifnet *ifp;
163 
164 	ifp = if_alloc(IFT_LOOP);
165 
166 	if_initname(ifp, ifc->ifc_name, unit);
167 
168 	ifp->if_mtu = LOMTU;
169 	ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST | IFF_RUNNING;
170 	ifp->if_ioctl = loioctl;
171 	ifp->if_output = looutput;
172 #ifdef ALTQ
173 	ifp->if_start = lostart;
174 #endif
175 	ifp->if_type = IFT_LOOP;
176 	ifp->if_hdrlen = 0;
177 	ifp->if_addrlen = 0;
178 	ifp->if_dlt = DLT_NULL;
179 	IFQ_SET_READY(&ifp->if_snd);
180 	if (unit == 0)
181 		lo0ifp = ifp;
182 	if_attach(ifp);
183 	if_alloc_sadl(ifp);
184 	bpf_attach(ifp, DLT_NULL, sizeof(u_int));
185 #ifdef MBUFTRACE
186 	ifp->if_mowner = malloc(sizeof(struct mowner), M_DEVBUF,
187 	    M_WAITOK | M_ZERO);
188 	strlcpy(ifp->if_mowner->mo_name, ifp->if_xname,
189 	    sizeof(ifp->if_mowner->mo_name));
190 	MOWNER_ATTACH(ifp->if_mowner);
191 #endif
192 
193 	return (0);
194 }
195 
196 static int
197 loop_clone_destroy(struct ifnet *ifp)
198 {
199 
200 	if (ifp == lo0ifp)
201 		return (EPERM);
202 
203 #ifdef MBUFTRACE
204 	MOWNER_DETACH(ifp->if_mowner);
205 	free(ifp->if_mowner, M_DEVBUF);
206 #endif
207 
208 	bpf_detach(ifp);
209 	if_detach(ifp);
210 
211 	free(ifp, M_DEVBUF);
212 
213 	return (0);
214 }
215 
216 int
217 looutput(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
218     struct rtentry *rt)
219 {
220 	int s, isr;
221 	struct ifqueue *ifq = NULL;
222 	int csum_flags;
223 
224 	MCLAIM(m, ifp->if_mowner);
225 	if ((m->m_flags & M_PKTHDR) == 0)
226 		panic("looutput: no header mbuf");
227 	if (ifp->if_flags & IFF_LOOPBACK)
228 		bpf_mtap_af(ifp, dst->sa_family, m);
229 	m->m_pkthdr.rcvif = ifp;
230 
231 	if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
232 		m_freem(m);
233 		return (rt->rt_flags & RTF_BLACKHOLE ? 0 :
234 			rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
235 	}
236 
237 	ifp->if_opackets++;
238 	ifp->if_obytes += m->m_pkthdr.len;
239 
240 #ifdef ALTQ
241 	/*
242 	 * ALTQ on the loopback interface is just for debugging.  It's
243 	 * used only for loopback interfaces, not for a simplex interface.
244 	 */
245 	if ((ALTQ_IS_ENABLED(&ifp->if_snd) || TBR_IS_ENABLED(&ifp->if_snd)) &&
246 	    ifp->if_start == lostart) {
247 		struct altq_pktattr pktattr;
248 		int error;
249 
250 		/*
251 		 * If the queueing discipline needs packet classification,
252 		 * do it before prepending the link headers.
253 		 */
254 		IFQ_CLASSIFY(&ifp->if_snd, m, dst->sa_family, &pktattr);
255 
256 		M_PREPEND(m, sizeof(uint32_t), M_DONTWAIT);
257 		if (m == NULL)
258 			return (ENOBUFS);
259 		*(mtod(m, uint32_t *)) = dst->sa_family;
260 
261 		s = splnet();
262 		IFQ_ENQUEUE(&ifp->if_snd, m, &pktattr, error);
263 		(*ifp->if_start)(ifp);
264 		splx(s);
265 		return (error);
266 	}
267 #endif /* ALTQ */
268 
269 	m_tag_delete_nonpersistent(m);
270 
271 	switch (dst->sa_family) {
272 
273 #ifdef INET
274 	case AF_INET:
275 		csum_flags = m->m_pkthdr.csum_flags;
276 		KASSERT((csum_flags & ~(M_CSUM_IPv4|M_CSUM_UDPv4)) == 0);
277 		if (csum_flags != 0 && IN_LOOPBACK_NEED_CHECKSUM(csum_flags)) {
278 			ip_undefer_csum(m, 0, csum_flags);
279 		}
280 		m->m_pkthdr.csum_flags = 0;
281 		ifq = &ipintrq;
282 		isr = NETISR_IP;
283 		break;
284 #endif
285 #ifdef INET6
286 	case AF_INET6:
287 		csum_flags = m->m_pkthdr.csum_flags;
288 		KASSERT((csum_flags & ~M_CSUM_UDPv6) == 0);
289 		if (csum_flags != 0 &&
290 		    IN6_LOOPBACK_NEED_CHECKSUM(csum_flags)) {
291 			ip6_undefer_csum(m, 0, csum_flags);
292 		}
293 		m->m_pkthdr.csum_flags = 0;
294 		m->m_flags |= M_LOOP;
295 		ifq = &ip6intrq;
296 		isr = NETISR_IPV6;
297 		break;
298 #endif
299 #ifdef ISO
300 	case AF_ISO:
301 		ifq = &clnlintrq;
302 		isr = NETISR_ISO;
303 		break;
304 #endif
305 #ifdef IPX
306 	case AF_IPX:
307 		ifq = &ipxintrq;
308 		isr = NETISR_IPX;
309 		break;
310 #endif
311 #ifdef NETATALK
312 	case AF_APPLETALK:
313 	        ifq = &atintrq2;
314 		isr = NETISR_ATALK;
315 		break;
316 #endif
317 	default:
318 		printf("%s: can't handle af%d\n", ifp->if_xname,
319 		    dst->sa_family);
320 		m_freem(m);
321 		return (EAFNOSUPPORT);
322 	}
323 #ifdef MPLS
324 	if (rt != NULL && rt_gettag(rt) != NULL &&
325 	    rt_gettag(rt)->sa_family == AF_MPLS &&
326 	    (m->m_flags & (M_MCAST | M_BCAST)) == 0) {
327 		union mpls_shim msh;
328 		msh.s_addr = MPLS_GETSADDR(rt);
329 		if (msh.shim.label != MPLS_LABEL_IMPLNULL) {
330 			ifq = &mplsintrq;
331 			isr = NETISR_MPLS;
332 		}
333 	}
334 #endif
335 	s = splnet();
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 lostart(struct ifnet *ifp)
353 {
354 	struct ifqueue *ifq;
355 	struct mbuf *m;
356 	uint32_t af;
357 	int s, isr;
358 
359 	for (;;) {
360 		IFQ_DEQUEUE(&ifp->if_snd, m);
361 		if (m == NULL)
362 			return;
363 
364 		af = *(mtod(m, uint32_t *));
365 		m_adj(m, sizeof(uint32_t));
366 
367 		switch (af) {
368 #ifdef INET
369 		case AF_INET:
370 			ifq = &ipintrq;
371 			isr = NETISR_IP;
372 			break;
373 #endif
374 #ifdef INET6
375 		case AF_INET6:
376 			m->m_flags |= M_LOOP;
377 			ifq = &ip6intrq;
378 			isr = NETISR_IPV6;
379 			break;
380 #endif
381 #ifdef IPX
382 		case AF_IPX:
383 			ifq = &ipxintrq;
384 			isr = NETISR_IPX;
385 			break;
386 #endif
387 #ifdef ISO
388 		case AF_ISO:
389 			ifq = &clnlintrq;
390 			isr = NETISR_ISO;
391 			break;
392 #endif
393 #ifdef NETATALK
394 		case AF_APPLETALK:
395 			ifq = &atintrq2;
396 			isr = NETISR_ATALK;
397 			break;
398 #endif
399 		default:
400 			printf("%s: can't handle af%d\n", ifp->if_xname, af);
401 			m_freem(m);
402 			return;
403 		}
404 
405 		s = splnet();
406 		if (IF_QFULL(ifq)) {
407 			IF_DROP(ifq);
408 			splx(s);
409 			m_freem(m);
410 			return;
411 		}
412 		IF_ENQUEUE(ifq, m);
413 		schednetisr(isr);
414 		ifp->if_ipackets++;
415 		ifp->if_ibytes += m->m_pkthdr.len;
416 		splx(s);
417 	}
418 }
419 #endif /* ALTQ */
420 
421 /* ARGSUSED */
422 void
423 lortrequest(int cmd, struct rtentry *rt,
424     const struct rt_addrinfo *info)
425 {
426 
427 	if (rt)
428 		rt->rt_rmx.rmx_mtu = lo0ifp->if_mtu;
429 }
430 
431 /*
432  * Process an ioctl request.
433  */
434 /* ARGSUSED */
435 int
436 loioctl(struct ifnet *ifp, u_long cmd, void *data)
437 {
438 	struct ifaddr *ifa;
439 	struct ifreq *ifr = data;
440 	int error = 0;
441 
442 	switch (cmd) {
443 
444 	case SIOCINITIFADDR:
445 		ifp->if_flags |= IFF_UP;
446 		ifa = (struct ifaddr *)data;
447 		if (ifa != NULL /*&& ifa->ifa_addr->sa_family == AF_ISO*/)
448 			ifa->ifa_rtrequest = lortrequest;
449 		/*
450 		 * Everything else is done at a higher level.
451 		 */
452 		break;
453 
454 	case SIOCSIFMTU:
455 		if ((unsigned)ifr->ifr_mtu > LOMTU_MAX)
456 			error = EINVAL;
457 		else if ((error = ifioctl_common(ifp, cmd, data)) == ENETRESET){
458 			/* XXX update rt mtu for AF_ISO? */
459 			error = 0;
460 		}
461 		break;
462 
463 	case SIOCADDMULTI:
464 	case SIOCDELMULTI:
465 		if (ifr == NULL) {
466 			error = EAFNOSUPPORT;		/* XXX */
467 			break;
468 		}
469 		switch (ifreq_getaddr(cmd, ifr)->sa_family) {
470 
471 #ifdef INET
472 		case AF_INET:
473 			break;
474 #endif
475 #ifdef INET6
476 		case AF_INET6:
477 			break;
478 #endif
479 
480 		default:
481 			error = EAFNOSUPPORT;
482 			break;
483 		}
484 		break;
485 
486 	default:
487 		error = ifioctl_common(ifp, cmd, data);
488 	}
489 	return (error);
490 }
491