xref: /netbsd-src/sys/net/if_loop.c (revision e55cffd8e520e9b03f18a1bd98bb04223e79f69f)
1 /*	$NetBSD: if_loop.c,v 1.38 2001/04/13 23:30:14 thorpej 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. All advertising materials mentioning features or use of this software
45  *    must display the following acknowledgement:
46  *	This product includes software developed by the University of
47  *	California, Berkeley and its contributors.
48  * 4. Neither the name of the University nor the names of its contributors
49  *    may be used to endorse or promote products derived from this software
50  *    without specific prior written permission.
51  *
52  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
53  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
54  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
55  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
56  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
57  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
58  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
59  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
60  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
61  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
62  * SUCH DAMAGE.
63  *
64  *	@(#)if_loop.c	8.2 (Berkeley) 1/9/95
65  */
66 
67 /*
68  * Loopback interface driver for protocol testing and timing.
69  */
70 
71 #include "opt_inet.h"
72 #include "opt_atalk.h"
73 #include "opt_iso.h"
74 #include "opt_ns.h"
75 
76 #include "bpfilter.h"
77 #include "loop.h"
78 
79 #include <sys/param.h>
80 #include <sys/systm.h>
81 #include <sys/kernel.h>
82 #include <sys/mbuf.h>
83 #include <sys/socket.h>
84 #include <sys/errno.h>
85 #include <sys/ioctl.h>
86 #include <sys/time.h>
87 
88 #include <machine/cpu.h>
89 
90 #include <net/if.h>
91 #include <net/if_types.h>
92 #include <net/netisr.h>
93 #include <net/route.h>
94 
95 #ifdef	INET
96 #include <netinet/in.h>
97 #include <netinet/in_systm.h>
98 #include <netinet/in_var.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 <netinet/ip6.h>
108 #endif
109 
110 #ifdef NS
111 #include <netns/ns.h>
112 #include <netns/ns_if.h>
113 #endif
114 
115 #ifdef IPX
116 #include <netipx/ipx.h>
117 #include <netipx/ipx_if.h>
118 #endif
119 
120 #ifdef ISO
121 #include <netiso/iso.h>
122 #include <netiso/iso_var.h>
123 #endif
124 
125 #ifdef NETATALK
126 #include <netatalk/at.h>
127 #include <netatalk/at_var.h>
128 #endif
129 
130 #if NBPFILTER > 0
131 #include <net/bpf.h>
132 #endif
133 
134 #if defined(LARGE_LOMTU)
135 #define LOMTU	(131072 +  MHLEN + MLEN)
136 #else
137 #define	LOMTU	(32768 +  MHLEN + MLEN)
138 #endif
139 
140 struct	ifnet loif[NLOOP];
141 
142 #ifdef ALTQ
143 void	lostart(struct ifnet *);
144 #endif
145 
146 void
147 loopattach(n)
148 	int n;
149 {
150 	int i;
151 	struct ifnet *ifp;
152 
153 	for (i = 0; i < NLOOP; i++) {
154 		ifp = &loif[i];
155 		sprintf(ifp->if_xname, "lo%d", i);
156 		ifp->if_softc = NULL;
157 		ifp->if_mtu = LOMTU;
158 		ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST;
159 		ifp->if_ioctl = loioctl;
160 		ifp->if_output = looutput;
161 #ifdef ALTQ
162 		ifp->if_start = lostart;
163 #endif
164 		ifp->if_type = IFT_LOOP;
165 		ifp->if_hdrlen = 0;
166 		ifp->if_addrlen = 0;
167 		ifp->if_dlt = DLT_NULL;
168 		IFQ_SET_READY(&ifp->if_snd);
169 		if_attach(ifp);
170 		if_alloc_sadl(ifp);
171 #if NBPFILTER > 0
172 		bpfattach(ifp, DLT_NULL, sizeof(u_int));
173 #endif
174 	}
175 }
176 
177 int
178 looutput(ifp, m, dst, rt)
179 	struct ifnet *ifp;
180 	struct mbuf *m;
181 	struct sockaddr *dst;
182 	struct rtentry *rt;
183 {
184 	int s, isr;
185 	struct ifqueue *ifq = 0;
186 
187 	if ((m->m_flags & M_PKTHDR) == 0)
188 		panic("looutput: no header mbuf");
189 	ifp->if_lastchange = time;
190 #if NBPFILTER > 0
191 	if (ifp->if_bpf && (ifp->if_flags & IFF_LOOPBACK)) {
192 		/*
193 		 * We need to prepend the address family as
194 		 * a four byte field.  Cons up a dummy header
195 		 * to pacify bpf.  This is safe because bpf
196 		 * will only read from the mbuf (i.e., it won't
197 		 * try to free it or keep a pointer to it).
198 		 */
199 		struct mbuf m0;
200 		u_int32_t af = dst->sa_family;
201 
202 		m0.m_next = m;
203 		m0.m_len = 4;
204 		m0.m_data = (char *)&af;
205 
206 		bpf_mtap(ifp->if_bpf, &m0);
207 	}
208 #endif
209 	m->m_pkthdr.rcvif = ifp;
210 
211 	if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
212 		m_freem(m);
213 		return (rt->rt_flags & RTF_BLACKHOLE ? 0 :
214 			rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
215 	}
216 
217 #ifndef PULLDOWN_TEST
218 	/*
219 	 * KAME requires that the packet to be contiguous on the
220 	 * mbuf.  We need to make that sure.
221 	 * this kind of code should be avoided.
222 	 * XXX other conditions to avoid running this part?
223 	 */
224 	if (m->m_len != m->m_pkthdr.len) {
225 		struct mbuf *n = NULL;
226 		int maxlen;
227 
228 		MGETHDR(n, M_DONTWAIT, MT_HEADER);
229 		maxlen = MHLEN;
230 		if (n)
231 			M_COPY_PKTHDR(n, m);
232 		if (n && m->m_pkthdr.len > maxlen) {
233 			MCLGET(n, M_DONTWAIT);
234 			maxlen = MCLBYTES;
235 			if ((n->m_flags & M_EXT) == 0) {
236 				m_free(n);
237 				n = NULL;
238 			}
239 		}
240 		if (!n) {
241 			printf("looutput: mbuf allocation failed\n");
242 			m_freem(m);
243 			return ENOBUFS;
244 		}
245 
246 		if (m->m_pkthdr.len <= maxlen) {
247 			m_copydata(m, 0, m->m_pkthdr.len, mtod(n, caddr_t));
248 			n->m_len = m->m_pkthdr.len;
249 			n->m_next = NULL;
250 			m_freem(m);
251 		} else {
252 			m_copydata(m, 0, maxlen, mtod(n, caddr_t));
253 			m_adj(m, maxlen);
254 			n->m_len = maxlen;
255 			n->m_next = m;
256 			m->m_flags &= ~M_PKTHDR;
257 		}
258 		m = n;
259 	}
260 #if 0
261 	if (m && m->m_next != NULL) {
262 		printf("loop: not contiguous...\n");
263 		m_freem(m);
264 		return ENOBUFS;
265 	}
266 #endif
267 #endif
268 
269 	ifp->if_opackets++;
270 	ifp->if_obytes += m->m_pkthdr.len;
271 
272 #ifdef ALTQ
273 	/*
274 	 * ALTQ on the loopback interface is just for debugging.  It's
275 	 * used only for loopback interfaces, not for a simplex interface.
276 	 */
277 	if ((ALTQ_IS_ENABLED(&ifp->if_snd) || TBR_IS_ENABLED(&ifp->if_snd)) &&
278 	    ifp->if_start == lostart) {
279 		struct altq_pktattr pktattr;
280 		int error;
281 
282 		/*
283 		 * If the queueing discipline needs packet classification,
284 		 * do it before prepending the link headers.
285 		 */
286 		IFQ_CLASSIFY(&ifp->if_snd, m, dst->sa_family, &pktattr);
287 
288 		M_PREPEND(m, sizeof(uint32_t), M_DONTWAIT);
289 		if (m == NULL)
290 			return (ENOBUFS);
291 		*(mtod(m, uint32_t *)) = dst->sa_family;
292 
293 		s = splnet();
294 		IFQ_ENQUEUE(&ifp->if_snd, m, &pktattr, error);
295 		(*ifp->if_start)(ifp);
296 		splx(s);
297 		return (error);
298 	}
299 #endif /* ALTQ */
300 
301 	switch (dst->sa_family) {
302 
303 #ifdef INET
304 	case AF_INET:
305 		ifq = &ipintrq;
306 		isr = NETISR_IP;
307 		break;
308 #endif
309 #ifdef INET6
310 	case AF_INET6:
311 		m->m_flags |= M_LOOP;
312 		ifq = &ip6intrq;
313 		isr = NETISR_IPV6;
314 		break;
315 #endif
316 #ifdef NS
317 	case AF_NS:
318 		ifq = &nsintrq;
319 		isr = NETISR_NS;
320 		break;
321 #endif
322 #ifdef ISO
323 	case AF_ISO:
324 		ifq = &clnlintrq;
325 		isr = NETISR_ISO;
326 		break;
327 #endif
328 #ifdef IPX
329 	case AF_IPX:
330 		ifq = &ipxintrq;
331 		isr = NETISR_IPX;
332 		break;
333 #endif
334 #ifdef NETATALK
335 	case AF_APPLETALK:
336 	        ifq = &atintrq2;
337 		isr = NETISR_ATALK;
338 		break;
339 #endif
340 	default:
341 		printf("%s: can't handle af%d\n", ifp->if_xname,
342 		    dst->sa_family);
343 		m_freem(m);
344 		return (EAFNOSUPPORT);
345 	}
346 	s = splnet();
347 	if (IF_QFULL(ifq)) {
348 		IF_DROP(ifq);
349 		m_freem(m);
350 		splx(s);
351 		return (ENOBUFS);
352 	}
353 	IF_ENQUEUE(ifq, m);
354 	schednetisr(isr);
355 	ifp->if_ipackets++;
356 	ifp->if_ibytes += m->m_pkthdr.len;
357 	splx(s);
358 	return (0);
359 }
360 
361 #ifdef ALTQ
362 void
363 lostart(struct ifnet *ifp)
364 {
365 	struct ifqueue *ifq;
366 	struct mbuf *m;
367 	uint32_t af;
368 	int s, isr;
369 
370 	for (;;) {
371 		IFQ_DEQUEUE(&ifp->if_snd, m);
372 		if (m == NULL)
373 			return;
374 
375 		af = *(mtod(m, uint32_t *));
376 		m_adj(m, sizeof(uint32_t));
377 
378 		switch (af) {
379 #ifdef INET
380 		case AF_INET:
381 			ifq = &ipintrq;
382 			isr = NETISR_IP;
383 			break;
384 #endif
385 #ifdef INET6
386 		case AF_INET6:
387 			m->m_flags |= M_LOOP;
388 			ifq = &ip6intrq;
389 			isr = NETISR_IPV6;
390 			break;
391 #endif
392 #ifdef IPX
393 		case AF_IPX:
394 			ifq = &ipxintrq;
395 			isr = NETISR_IPX;
396 			break;
397 #endif
398 #ifdef NS
399 		case AF_NS:
400 			ifq = &nsintrq;
401 			isr = NETISR_NS;
402 			break;
403 #endif
404 #ifdef ISO
405 		case AF_ISO:
406 			ifq = &clnlintrq;
407 			isr = NETISR_ISO;
408 			break;
409 #endif
410 #ifdef NETATALK
411 		case AF_APPLETALK:
412 			ifq = &atintrq2;
413 			isr = NETISR_ATALK;
414 			break;
415 #endif
416 		default:
417 			printf("%s: can't handle af%d\n", ifp->if_xname, af);
418 			m_freem(m);
419 			return;
420 		}
421 
422 		s = splnet();
423 		if (IF_QFULL(ifq)) {
424 			IF_DROP(ifq);
425 			splx(s);
426 			m_freem(m);
427 			return;
428 		}
429 		IF_ENQUEUE(ifq, m);
430 		schednetisr(isr);
431 		ifp->if_ipackets++;
432 		ifp->if_ibytes += m->m_pkthdr.len;
433 		splx(s);
434 	}
435 }
436 #endif /* ALTQ */
437 
438 /* ARGSUSED */
439 void
440 lortrequest(cmd, rt, info)
441 	int cmd;
442 	struct rtentry *rt;
443 	struct rt_addrinfo *info;
444 {
445 
446 	if (rt)
447 		rt->rt_rmx.rmx_mtu = LOMTU;
448 }
449 
450 /*
451  * Process an ioctl request.
452  */
453 /* ARGSUSED */
454 int
455 loioctl(ifp, cmd, data)
456 	struct ifnet *ifp;
457 	u_long cmd;
458 	caddr_t data;
459 {
460 	struct ifaddr *ifa;
461 	struct ifreq *ifr;
462 	int error = 0;
463 
464 	switch (cmd) {
465 
466 	case SIOCSIFADDR:
467 		ifp->if_flags |= IFF_UP;
468 		ifa = (struct ifaddr *)data;
469 		if (ifa != 0 /*&& ifa->ifa_addr->sa_family == AF_ISO*/)
470 			ifa->ifa_rtrequest = lortrequest;
471 		/*
472 		 * Everything else is done at a higher level.
473 		 */
474 		break;
475 
476 	case SIOCADDMULTI:
477 	case SIOCDELMULTI:
478 		ifr = (struct ifreq *)data;
479 		if (ifr == 0) {
480 			error = EAFNOSUPPORT;		/* XXX */
481 			break;
482 		}
483 		switch (ifr->ifr_addr.sa_family) {
484 
485 #ifdef INET
486 		case AF_INET:
487 			break;
488 #endif
489 #ifdef INET6
490 		case AF_INET6:
491 			break;
492 #endif
493 
494 		default:
495 			error = EAFNOSUPPORT;
496 			break;
497 		}
498 		break;
499 
500 	default:
501 		error = EINVAL;
502 	}
503 	return (error);
504 }
505