xref: /netbsd-src/sys/net/if_loop.c (revision a536ee5124e62c9a0051a252f7833dc8f50f44c9) 
1 /*	$NetBSD: if_loop.c,v 1.75 2011/06/20 09:43:27 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 1.75 2011/06/20 09:43:27 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 = -1;
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 #ifdef MPLS
272 	if (rt != NULL && rt_gettag(rt) != NULL &&
273 	    rt_gettag(rt)->sa_family == AF_MPLS &&
274 	    (m->m_flags & (M_MCAST | M_BCAST)) == 0) {
275 		union mpls_shim msh;
276 		msh.s_addr = MPLS_GETSADDR(rt);
277 		if (msh.shim.label != MPLS_LABEL_IMPLNULL) {
278 			ifq = &mplsintrq;
279 			isr = NETISR_MPLS;
280 		}
281 	}
282 	if (isr != NETISR_MPLS)
283 #endif
284 	switch (dst->sa_family) {
285 
286 #ifdef INET
287 	case AF_INET:
288 		csum_flags = m->m_pkthdr.csum_flags;
289 		KASSERT((csum_flags & ~(M_CSUM_IPv4|M_CSUM_UDPv4)) == 0);
290 		if (csum_flags != 0 && IN_LOOPBACK_NEED_CHECKSUM(csum_flags)) {
291 			ip_undefer_csum(m, 0, csum_flags);
292 		}
293 		m->m_pkthdr.csum_flags = 0;
294 		ifq = &ipintrq;
295 		isr = NETISR_IP;
296 		break;
297 #endif
298 #ifdef INET6
299 	case AF_INET6:
300 		csum_flags = m->m_pkthdr.csum_flags;
301 		KASSERT((csum_flags & ~M_CSUM_UDPv6) == 0);
302 		if (csum_flags != 0 &&
303 		    IN6_LOOPBACK_NEED_CHECKSUM(csum_flags)) {
304 			ip6_undefer_csum(m, 0, csum_flags);
305 		}
306 		m->m_pkthdr.csum_flags = 0;
307 		m->m_flags |= M_LOOP;
308 		ifq = &ip6intrq;
309 		isr = NETISR_IPV6;
310 		break;
311 #endif
312 #ifdef ISO
313 	case AF_ISO:
314 		ifq = &clnlintrq;
315 		isr = NETISR_ISO;
316 		break;
317 #endif
318 #ifdef IPX
319 	case AF_IPX:
320 		ifq = &ipxintrq;
321 		isr = NETISR_IPX;
322 		break;
323 #endif
324 #ifdef NETATALK
325 	case AF_APPLETALK:
326 	        ifq = &atintrq2;
327 		isr = NETISR_ATALK;
328 		break;
329 #endif
330 	default:
331 		printf("%s: can't handle af%d\n", ifp->if_xname,
332 		    dst->sa_family);
333 		m_freem(m);
334 		return (EAFNOSUPPORT);
335 	}
336 	s = splnet();
337 	if (IF_QFULL(ifq)) {
338 		IF_DROP(ifq);
339 		m_freem(m);
340 		splx(s);
341 		return (ENOBUFS);
342 	}
343 	IF_ENQUEUE(ifq, m);
344 	schednetisr(isr);
345 	ifp->if_ipackets++;
346 	ifp->if_ibytes += m->m_pkthdr.len;
347 	splx(s);
348 	return (0);
349 }
350 
351 #ifdef ALTQ
352 static void
353 lostart(struct ifnet *ifp)
354 {
355 	struct ifqueue *ifq;
356 	struct mbuf *m;
357 	uint32_t af;
358 	int s, isr;
359 
360 	for (;;) {
361 		IFQ_DEQUEUE(&ifp->if_snd, m);
362 		if (m == NULL)
363 			return;
364 
365 		af = *(mtod(m, uint32_t *));
366 		m_adj(m, sizeof(uint32_t));
367 
368 		switch (af) {
369 #ifdef INET
370 		case AF_INET:
371 			ifq = &ipintrq;
372 			isr = NETISR_IP;
373 			break;
374 #endif
375 #ifdef INET6
376 		case AF_INET6:
377 			m->m_flags |= M_LOOP;
378 			ifq = &ip6intrq;
379 			isr = NETISR_IPV6;
380 			break;
381 #endif
382 #ifdef IPX
383 		case AF_IPX:
384 			ifq = &ipxintrq;
385 			isr = NETISR_IPX;
386 			break;
387 #endif
388 #ifdef ISO
389 		case AF_ISO:
390 			ifq = &clnlintrq;
391 			isr = NETISR_ISO;
392 			break;
393 #endif
394 #ifdef NETATALK
395 		case AF_APPLETALK:
396 			ifq = &atintrq2;
397 			isr = NETISR_ATALK;
398 			break;
399 #endif
400 		default:
401 			printf("%s: can't handle af%d\n", ifp->if_xname, af);
402 			m_freem(m);
403 			return;
404 		}
405 
406 		s = splnet();
407 		if (IF_QFULL(ifq)) {
408 			IF_DROP(ifq);
409 			splx(s);
410 			m_freem(m);
411 			return;
412 		}
413 		IF_ENQUEUE(ifq, m);
414 		schednetisr(isr);
415 		ifp->if_ipackets++;
416 		ifp->if_ibytes += m->m_pkthdr.len;
417 		splx(s);
418 	}
419 }
420 #endif /* ALTQ */
421 
422 /* ARGSUSED */
423 void
424 lortrequest(int cmd, struct rtentry *rt,
425     const struct rt_addrinfo *info)
426 {
427 
428 	if (rt)
429 		rt->rt_rmx.rmx_mtu = lo0ifp->if_mtu;
430 }
431 
432 /*
433  * Process an ioctl request.
434  */
435 /* ARGSUSED */
436 int
437 loioctl(struct ifnet *ifp, u_long cmd, void *data)
438 {
439 	struct ifaddr *ifa;
440 	struct ifreq *ifr = data;
441 	int error = 0;
442 
443 	switch (cmd) {
444 
445 	case SIOCINITIFADDR:
446 		ifp->if_flags |= IFF_UP;
447 		ifa = (struct ifaddr *)data;
448 		if (ifa != NULL /*&& ifa->ifa_addr->sa_family == AF_ISO*/)
449 			ifa->ifa_rtrequest = lortrequest;
450 		/*
451 		 * Everything else is done at a higher level.
452 		 */
453 		break;
454 
455 	case SIOCSIFMTU:
456 		if ((unsigned)ifr->ifr_mtu > LOMTU_MAX)
457 			error = EINVAL;
458 		else if ((error = ifioctl_common(ifp, cmd, data)) == ENETRESET){
459 			/* XXX update rt mtu for AF_ISO? */
460 			error = 0;
461 		}
462 		break;
463 
464 	case SIOCADDMULTI:
465 	case SIOCDELMULTI:
466 		if (ifr == NULL) {
467 			error = EAFNOSUPPORT;		/* XXX */
468 			break;
469 		}
470 		switch (ifreq_getaddr(cmd, ifr)->sa_family) {
471 
472 #ifdef INET
473 		case AF_INET:
474 			break;
475 #endif
476 #ifdef INET6
477 		case AF_INET6:
478 			break;
479 #endif
480 
481 		default:
482 			error = EAFNOSUPPORT;
483 			break;
484 		}
485 		break;
486 
487 	default:
488 		error = ifioctl_common(ifp, cmd, data);
489 	}
490 	return (error);
491 }
492