xref: /netbsd-src/sys/net/if_loop.c (revision 1ffa7b76c40339c17a0fb2a09fac93f287cfc046)
1 /*	$NetBSD: if_loop.c,v 1.43 2003/05/01 07:52:58 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 <sys/cdefs.h>
72 __KERNEL_RCSID(0, "$NetBSD: if_loop.c,v 1.43 2003/05/01 07:52:58 itojun Exp $");
73 
74 #include "opt_inet.h"
75 #include "opt_atalk.h"
76 #include "opt_iso.h"
77 #include "opt_ns.h"
78 
79 #include "bpfilter.h"
80 #include "loop.h"
81 
82 #include <sys/param.h>
83 #include <sys/systm.h>
84 #include <sys/kernel.h>
85 #include <sys/mbuf.h>
86 #include <sys/socket.h>
87 #include <sys/errno.h>
88 #include <sys/ioctl.h>
89 #include <sys/time.h>
90 
91 #include <machine/cpu.h>
92 
93 #include <net/if.h>
94 #include <net/if_types.h>
95 #include <net/netisr.h>
96 #include <net/route.h>
97 
98 #ifdef	INET
99 #include <netinet/in.h>
100 #include <netinet/in_systm.h>
101 #include <netinet/in_var.h>
102 #include <netinet/ip.h>
103 #endif
104 
105 #ifdef INET6
106 #ifndef INET
107 #include <netinet/in.h>
108 #endif
109 #include <netinet6/in6_var.h>
110 #include <netinet/ip6.h>
111 #endif
112 
113 #ifdef NS
114 #include <netns/ns.h>
115 #include <netns/ns_if.h>
116 #endif
117 
118 #ifdef IPX
119 #include <netipx/ipx.h>
120 #include <netipx/ipx_if.h>
121 #endif
122 
123 #ifdef ISO
124 #include <netiso/iso.h>
125 #include <netiso/iso_var.h>
126 #endif
127 
128 #ifdef NETATALK
129 #include <netatalk/at.h>
130 #include <netatalk/at_var.h>
131 #endif
132 
133 #if NBPFILTER > 0
134 #include <net/bpf.h>
135 #endif
136 
137 #if defined(LARGE_LOMTU)
138 #define LOMTU	(131072 +  MHLEN + MLEN)
139 #else
140 #define	LOMTU	(32768 +  MHLEN + MLEN)
141 #endif
142 
143 struct	ifnet loif[NLOOP];
144 #ifdef MBUFTRACE
145 struct	mowner lomowner[NLOOP];
146 #endif
147 
148 #ifdef ALTQ
149 void	lostart(struct ifnet *);
150 #endif
151 
152 void
153 loopattach(n)
154 	int n;
155 {
156 	int i;
157 	struct ifnet *ifp;
158 
159 	for (i = 0; i < NLOOP; i++) {
160 		ifp = &loif[i];
161 		sprintf(ifp->if_xname, "lo%d", i);
162 		ifp->if_softc = NULL;
163 		ifp->if_mtu = LOMTU;
164 		ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST;
165 		ifp->if_ioctl = loioctl;
166 		ifp->if_output = looutput;
167 #ifdef ALTQ
168 		ifp->if_start = lostart;
169 #endif
170 		ifp->if_type = IFT_LOOP;
171 		ifp->if_hdrlen = 0;
172 		ifp->if_addrlen = 0;
173 		ifp->if_dlt = DLT_NULL;
174 		IFQ_SET_READY(&ifp->if_snd);
175 		if_attach(ifp);
176 		if_alloc_sadl(ifp);
177 #if NBPFILTER > 0
178 		bpfattach(ifp, DLT_NULL, sizeof(u_int));
179 #endif
180 #ifdef MBUFTRACE
181 		ifp->if_mowner = &lomowner[i];
182 		strcpy(ifp->if_mowner->mo_name, ifp->if_xname);
183 		MOWNER_ATTACH(&lomowner[i]);
184 #endif
185 	}
186 }
187 
188 int
189 looutput(ifp, m, dst, rt)
190 	struct ifnet *ifp;
191 	struct mbuf *m;
192 	struct sockaddr *dst;
193 	struct rtentry *rt;
194 {
195 	int s, isr;
196 	struct ifqueue *ifq = 0;
197 
198 	MCLAIM(m, ifp->if_mowner);
199 	if ((m->m_flags & M_PKTHDR) == 0)
200 		panic("looutput: no header mbuf");
201 #if NBPFILTER > 0
202 	if (ifp->if_bpf && (ifp->if_flags & IFF_LOOPBACK)) {
203 		/*
204 		 * We need to prepend the address family as
205 		 * a four byte field.  Cons up a dummy header
206 		 * to pacify bpf.  This is safe because bpf
207 		 * will only read from the mbuf (i.e., it won't
208 		 * try to free it or keep a pointer to it).
209 		 */
210 		struct mbuf m0;
211 		u_int32_t af = dst->sa_family;
212 
213 		m0.m_flags = 0;
214 		m0.m_next = m;
215 		m0.m_len = 4;
216 		m0.m_data = (char *)&af;
217 
218 		bpf_mtap(ifp->if_bpf, &m0);
219 	}
220 #endif
221 	m->m_pkthdr.rcvif = ifp;
222 
223 	if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
224 		m_freem(m);
225 		return (rt->rt_flags & RTF_BLACKHOLE ? 0 :
226 			rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
227 	}
228 
229 #ifndef PULLDOWN_TEST
230 	/*
231 	 * KAME requires that the packet to be contiguous on the
232 	 * mbuf.  We need to make that sure.
233 	 * this kind of code should be avoided.
234 	 * XXX other conditions to avoid running this part?
235 	 */
236 	if (m->m_len != m->m_pkthdr.len) {
237 		struct mbuf *n = NULL;
238 		int maxlen;
239 
240 		MGETHDR(n, M_DONTWAIT, MT_HEADER);
241 		maxlen = MHLEN;
242 		if (n)
243 			M_COPY_PKTHDR(n, m);
244 		if (n && m->m_pkthdr.len > maxlen) {
245 			MCLGET(n, M_DONTWAIT);
246 			maxlen = MCLBYTES;
247 			if ((n->m_flags & M_EXT) == 0) {
248 				m_free(n);
249 				n = NULL;
250 			}
251 		}
252 		if (!n) {
253 			printf("looutput: mbuf allocation failed\n");
254 			m_freem(m);
255 			return ENOBUFS;
256 		}
257 
258 		if (m->m_pkthdr.len <= maxlen) {
259 			m_copydata(m, 0, m->m_pkthdr.len, mtod(n, caddr_t));
260 			n->m_len = m->m_pkthdr.len;
261 			n->m_next = NULL;
262 			m_freem(m);
263 		} else {
264 			m_copydata(m, 0, maxlen, mtod(n, caddr_t));
265 			m_adj(m, maxlen);
266 			n->m_len = maxlen;
267 			n->m_next = m;
268 			m->m_flags &= ~M_PKTHDR;
269 		}
270 		m = n;
271 	}
272 #if 0
273 	if (m && m->m_next != NULL) {
274 		printf("loop: not contiguous...\n");
275 		m_freem(m);
276 		return ENOBUFS;
277 	}
278 #endif
279 #endif
280 
281 	ifp->if_opackets++;
282 	ifp->if_obytes += m->m_pkthdr.len;
283 
284 #ifdef ALTQ
285 	/*
286 	 * ALTQ on the loopback interface is just for debugging.  It's
287 	 * used only for loopback interfaces, not for a simplex interface.
288 	 */
289 	if ((ALTQ_IS_ENABLED(&ifp->if_snd) || TBR_IS_ENABLED(&ifp->if_snd)) &&
290 	    ifp->if_start == lostart) {
291 		struct altq_pktattr pktattr;
292 		int error;
293 
294 		/*
295 		 * If the queueing discipline needs packet classification,
296 		 * do it before prepending the link headers.
297 		 */
298 		IFQ_CLASSIFY(&ifp->if_snd, m, dst->sa_family, &pktattr);
299 
300 		M_PREPEND(m, sizeof(uint32_t), M_DONTWAIT);
301 		if (m == NULL)
302 			return (ENOBUFS);
303 		*(mtod(m, uint32_t *)) = dst->sa_family;
304 
305 		s = splnet();
306 		IFQ_ENQUEUE(&ifp->if_snd, m, &pktattr, error);
307 		(*ifp->if_start)(ifp);
308 		splx(s);
309 		return (error);
310 	}
311 #endif /* ALTQ */
312 
313 	switch (dst->sa_family) {
314 
315 #ifdef INET
316 	case AF_INET:
317 		ifq = &ipintrq;
318 		isr = NETISR_IP;
319 		break;
320 #endif
321 #ifdef INET6
322 	case AF_INET6:
323 		m->m_flags |= M_LOOP;
324 		ifq = &ip6intrq;
325 		isr = NETISR_IPV6;
326 		break;
327 #endif
328 #ifdef NS
329 	case AF_NS:
330 		ifq = &nsintrq;
331 		isr = NETISR_NS;
332 		break;
333 #endif
334 #ifdef ISO
335 	case AF_ISO:
336 		ifq = &clnlintrq;
337 		isr = NETISR_ISO;
338 		break;
339 #endif
340 #ifdef IPX
341 	case AF_IPX:
342 		ifq = &ipxintrq;
343 		isr = NETISR_IPX;
344 		break;
345 #endif
346 #ifdef NETATALK
347 	case AF_APPLETALK:
348 	        ifq = &atintrq2;
349 		isr = NETISR_ATALK;
350 		break;
351 #endif
352 	default:
353 		printf("%s: can't handle af%d\n", ifp->if_xname,
354 		    dst->sa_family);
355 		m_freem(m);
356 		return (EAFNOSUPPORT);
357 	}
358 	s = splnet();
359 	if (IF_QFULL(ifq)) {
360 		IF_DROP(ifq);
361 		m_freem(m);
362 		splx(s);
363 		return (ENOBUFS);
364 	}
365 	IF_ENQUEUE(ifq, m);
366 	schednetisr(isr);
367 	ifp->if_ipackets++;
368 	ifp->if_ibytes += m->m_pkthdr.len;
369 	splx(s);
370 	return (0);
371 }
372 
373 #ifdef ALTQ
374 void
375 lostart(struct ifnet *ifp)
376 {
377 	struct ifqueue *ifq;
378 	struct mbuf *m;
379 	uint32_t af;
380 	int s, isr;
381 
382 	for (;;) {
383 		IFQ_DEQUEUE(&ifp->if_snd, m);
384 		if (m == NULL)
385 			return;
386 
387 		af = *(mtod(m, uint32_t *));
388 		m_adj(m, sizeof(uint32_t));
389 
390 		switch (af) {
391 #ifdef INET
392 		case AF_INET:
393 			ifq = &ipintrq;
394 			isr = NETISR_IP;
395 			break;
396 #endif
397 #ifdef INET6
398 		case AF_INET6:
399 			m->m_flags |= M_LOOP;
400 			ifq = &ip6intrq;
401 			isr = NETISR_IPV6;
402 			break;
403 #endif
404 #ifdef IPX
405 		case AF_IPX:
406 			ifq = &ipxintrq;
407 			isr = NETISR_IPX;
408 			break;
409 #endif
410 #ifdef NS
411 		case AF_NS:
412 			ifq = &nsintrq;
413 			isr = NETISR_NS;
414 			break;
415 #endif
416 #ifdef ISO
417 		case AF_ISO:
418 			ifq = &clnlintrq;
419 			isr = NETISR_ISO;
420 			break;
421 #endif
422 #ifdef NETATALK
423 		case AF_APPLETALK:
424 			ifq = &atintrq2;
425 			isr = NETISR_ATALK;
426 			break;
427 #endif
428 		default:
429 			printf("%s: can't handle af%d\n", ifp->if_xname, af);
430 			m_freem(m);
431 			return;
432 		}
433 
434 		s = splnet();
435 		if (IF_QFULL(ifq)) {
436 			IF_DROP(ifq);
437 			splx(s);
438 			m_freem(m);
439 			return;
440 		}
441 		IF_ENQUEUE(ifq, m);
442 		schednetisr(isr);
443 		ifp->if_ipackets++;
444 		ifp->if_ibytes += m->m_pkthdr.len;
445 		splx(s);
446 	}
447 }
448 #endif /* ALTQ */
449 
450 /* ARGSUSED */
451 void
452 lortrequest(cmd, rt, info)
453 	int cmd;
454 	struct rtentry *rt;
455 	struct rt_addrinfo *info;
456 {
457 
458 	if (rt)
459 		rt->rt_rmx.rmx_mtu = LOMTU;
460 }
461 
462 /*
463  * Process an ioctl request.
464  */
465 /* ARGSUSED */
466 int
467 loioctl(ifp, cmd, data)
468 	struct ifnet *ifp;
469 	u_long cmd;
470 	caddr_t data;
471 {
472 	struct ifaddr *ifa;
473 	struct ifreq *ifr;
474 	int error = 0;
475 
476 	switch (cmd) {
477 
478 	case SIOCSIFADDR:
479 		ifp->if_flags |= IFF_UP;
480 		ifa = (struct ifaddr *)data;
481 		if (ifa != 0 /*&& ifa->ifa_addr->sa_family == AF_ISO*/)
482 			ifa->ifa_rtrequest = lortrequest;
483 		/*
484 		 * Everything else is done at a higher level.
485 		 */
486 		break;
487 
488 	case SIOCADDMULTI:
489 	case SIOCDELMULTI:
490 		ifr = (struct ifreq *)data;
491 		if (ifr == 0) {
492 			error = EAFNOSUPPORT;		/* XXX */
493 			break;
494 		}
495 		switch (ifr->ifr_addr.sa_family) {
496 
497 #ifdef INET
498 		case AF_INET:
499 			break;
500 #endif
501 #ifdef INET6
502 		case AF_INET6:
503 			break;
504 #endif
505 
506 		default:
507 			error = EAFNOSUPPORT;
508 			break;
509 		}
510 		break;
511 
512 	default:
513 		error = EINVAL;
514 	}
515 	return (error);
516 }
517