xref: /netbsd-src/sys/net/if_loop.c (revision 3b01aba77a7a698587faaae455bbfe740923c1f5)
1 /*	$NetBSD: if_loop.c,v 1.39 2001/06/14 05:44:24 itojun 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 #if NBPFILTER > 0
190 	if (ifp->if_bpf && (ifp->if_flags & IFF_LOOPBACK)) {
191 		/*
192 		 * We need to prepend the address family as
193 		 * a four byte field.  Cons up a dummy header
194 		 * to pacify bpf.  This is safe because bpf
195 		 * will only read from the mbuf (i.e., it won't
196 		 * try to free it or keep a pointer to it).
197 		 */
198 		struct mbuf m0;
199 		u_int32_t af = dst->sa_family;
200 
201 		m0.m_next = m;
202 		m0.m_len = 4;
203 		m0.m_data = (char *)&af;
204 
205 		bpf_mtap(ifp->if_bpf, &m0);
206 	}
207 #endif
208 	m->m_pkthdr.rcvif = ifp;
209 
210 	if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
211 		m_freem(m);
212 		return (rt->rt_flags & RTF_BLACKHOLE ? 0 :
213 			rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
214 	}
215 
216 #ifndef PULLDOWN_TEST
217 	/*
218 	 * KAME requires that the packet to be contiguous on the
219 	 * mbuf.  We need to make that sure.
220 	 * this kind of code should be avoided.
221 	 * XXX other conditions to avoid running this part?
222 	 */
223 	if (m->m_len != m->m_pkthdr.len) {
224 		struct mbuf *n = NULL;
225 		int maxlen;
226 
227 		MGETHDR(n, M_DONTWAIT, MT_HEADER);
228 		maxlen = MHLEN;
229 		if (n)
230 			M_COPY_PKTHDR(n, m);
231 		if (n && m->m_pkthdr.len > maxlen) {
232 			MCLGET(n, M_DONTWAIT);
233 			maxlen = MCLBYTES;
234 			if ((n->m_flags & M_EXT) == 0) {
235 				m_free(n);
236 				n = NULL;
237 			}
238 		}
239 		if (!n) {
240 			printf("looutput: mbuf allocation failed\n");
241 			m_freem(m);
242 			return ENOBUFS;
243 		}
244 
245 		if (m->m_pkthdr.len <= maxlen) {
246 			m_copydata(m, 0, m->m_pkthdr.len, mtod(n, caddr_t));
247 			n->m_len = m->m_pkthdr.len;
248 			n->m_next = NULL;
249 			m_freem(m);
250 		} else {
251 			m_copydata(m, 0, maxlen, mtod(n, caddr_t));
252 			m_adj(m, maxlen);
253 			n->m_len = maxlen;
254 			n->m_next = m;
255 			m->m_flags &= ~M_PKTHDR;
256 		}
257 		m = n;
258 	}
259 #if 0
260 	if (m && m->m_next != NULL) {
261 		printf("loop: not contiguous...\n");
262 		m_freem(m);
263 		return ENOBUFS;
264 	}
265 #endif
266 #endif
267 
268 	ifp->if_opackets++;
269 	ifp->if_obytes += m->m_pkthdr.len;
270 
271 #ifdef ALTQ
272 	/*
273 	 * ALTQ on the loopback interface is just for debugging.  It's
274 	 * used only for loopback interfaces, not for a simplex interface.
275 	 */
276 	if ((ALTQ_IS_ENABLED(&ifp->if_snd) || TBR_IS_ENABLED(&ifp->if_snd)) &&
277 	    ifp->if_start == lostart) {
278 		struct altq_pktattr pktattr;
279 		int error;
280 
281 		/*
282 		 * If the queueing discipline needs packet classification,
283 		 * do it before prepending the link headers.
284 		 */
285 		IFQ_CLASSIFY(&ifp->if_snd, m, dst->sa_family, &pktattr);
286 
287 		M_PREPEND(m, sizeof(uint32_t), M_DONTWAIT);
288 		if (m == NULL)
289 			return (ENOBUFS);
290 		*(mtod(m, uint32_t *)) = dst->sa_family;
291 
292 		s = splnet();
293 		IFQ_ENQUEUE(&ifp->if_snd, m, &pktattr, error);
294 		(*ifp->if_start)(ifp);
295 		splx(s);
296 		return (error);
297 	}
298 #endif /* ALTQ */
299 
300 	switch (dst->sa_family) {
301 
302 #ifdef INET
303 	case AF_INET:
304 		ifq = &ipintrq;
305 		isr = NETISR_IP;
306 		break;
307 #endif
308 #ifdef INET6
309 	case AF_INET6:
310 		m->m_flags |= M_LOOP;
311 		ifq = &ip6intrq;
312 		isr = NETISR_IPV6;
313 		break;
314 #endif
315 #ifdef NS
316 	case AF_NS:
317 		ifq = &nsintrq;
318 		isr = NETISR_NS;
319 		break;
320 #endif
321 #ifdef ISO
322 	case AF_ISO:
323 		ifq = &clnlintrq;
324 		isr = NETISR_ISO;
325 		break;
326 #endif
327 #ifdef IPX
328 	case AF_IPX:
329 		ifq = &ipxintrq;
330 		isr = NETISR_IPX;
331 		break;
332 #endif
333 #ifdef NETATALK
334 	case AF_APPLETALK:
335 	        ifq = &atintrq2;
336 		isr = NETISR_ATALK;
337 		break;
338 #endif
339 	default:
340 		printf("%s: can't handle af%d\n", ifp->if_xname,
341 		    dst->sa_family);
342 		m_freem(m);
343 		return (EAFNOSUPPORT);
344 	}
345 	s = splnet();
346 	if (IF_QFULL(ifq)) {
347 		IF_DROP(ifq);
348 		m_freem(m);
349 		splx(s);
350 		return (ENOBUFS);
351 	}
352 	IF_ENQUEUE(ifq, m);
353 	schednetisr(isr);
354 	ifp->if_ipackets++;
355 	ifp->if_ibytes += m->m_pkthdr.len;
356 	splx(s);
357 	return (0);
358 }
359 
360 #ifdef ALTQ
361 void
362 lostart(struct ifnet *ifp)
363 {
364 	struct ifqueue *ifq;
365 	struct mbuf *m;
366 	uint32_t af;
367 	int s, isr;
368 
369 	for (;;) {
370 		IFQ_DEQUEUE(&ifp->if_snd, m);
371 		if (m == NULL)
372 			return;
373 
374 		af = *(mtod(m, uint32_t *));
375 		m_adj(m, sizeof(uint32_t));
376 
377 		switch (af) {
378 #ifdef INET
379 		case AF_INET:
380 			ifq = &ipintrq;
381 			isr = NETISR_IP;
382 			break;
383 #endif
384 #ifdef INET6
385 		case AF_INET6:
386 			m->m_flags |= M_LOOP;
387 			ifq = &ip6intrq;
388 			isr = NETISR_IPV6;
389 			break;
390 #endif
391 #ifdef IPX
392 		case AF_IPX:
393 			ifq = &ipxintrq;
394 			isr = NETISR_IPX;
395 			break;
396 #endif
397 #ifdef NS
398 		case AF_NS:
399 			ifq = &nsintrq;
400 			isr = NETISR_NS;
401 			break;
402 #endif
403 #ifdef ISO
404 		case AF_ISO:
405 			ifq = &clnlintrq;
406 			isr = NETISR_ISO;
407 			break;
408 #endif
409 #ifdef NETATALK
410 		case AF_APPLETALK:
411 			ifq = &atintrq2;
412 			isr = NETISR_ATALK;
413 			break;
414 #endif
415 		default:
416 			printf("%s: can't handle af%d\n", ifp->if_xname, af);
417 			m_freem(m);
418 			return;
419 		}
420 
421 		s = splnet();
422 		if (IF_QFULL(ifq)) {
423 			IF_DROP(ifq);
424 			splx(s);
425 			m_freem(m);
426 			return;
427 		}
428 		IF_ENQUEUE(ifq, m);
429 		schednetisr(isr);
430 		ifp->if_ipackets++;
431 		ifp->if_ibytes += m->m_pkthdr.len;
432 		splx(s);
433 	}
434 }
435 #endif /* ALTQ */
436 
437 /* ARGSUSED */
438 void
439 lortrequest(cmd, rt, info)
440 	int cmd;
441 	struct rtentry *rt;
442 	struct rt_addrinfo *info;
443 {
444 
445 	if (rt)
446 		rt->rt_rmx.rmx_mtu = LOMTU;
447 }
448 
449 /*
450  * Process an ioctl request.
451  */
452 /* ARGSUSED */
453 int
454 loioctl(ifp, cmd, data)
455 	struct ifnet *ifp;
456 	u_long cmd;
457 	caddr_t data;
458 {
459 	struct ifaddr *ifa;
460 	struct ifreq *ifr;
461 	int error = 0;
462 
463 	switch (cmd) {
464 
465 	case SIOCSIFADDR:
466 		ifp->if_flags |= IFF_UP;
467 		ifa = (struct ifaddr *)data;
468 		if (ifa != 0 /*&& ifa->ifa_addr->sa_family == AF_ISO*/)
469 			ifa->ifa_rtrequest = lortrequest;
470 		/*
471 		 * Everything else is done at a higher level.
472 		 */
473 		break;
474 
475 	case SIOCADDMULTI:
476 	case SIOCDELMULTI:
477 		ifr = (struct ifreq *)data;
478 		if (ifr == 0) {
479 			error = EAFNOSUPPORT;		/* XXX */
480 			break;
481 		}
482 		switch (ifr->ifr_addr.sa_family) {
483 
484 #ifdef INET
485 		case AF_INET:
486 			break;
487 #endif
488 #ifdef INET6
489 		case AF_INET6:
490 			break;
491 #endif
492 
493 		default:
494 			error = EAFNOSUPPORT;
495 			break;
496 		}
497 		break;
498 
499 	default:
500 		error = EINVAL;
501 	}
502 	return (error);
503 }
504