xref: /netbsd/sys/net/if_loop.c (revision bf9ec67e) 
1 /*	$NetBSD: if_loop.c,v 1.40 2001/11/12 23:49:40 lukem 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 1.40 2001/11/12 23:49:40 lukem 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 
145 #ifdef ALTQ
146 void	lostart(struct ifnet *);
147 #endif
148 
149 void
150 loopattach(n)
151 	int n;
152 {
153 	int i;
154 	struct ifnet *ifp;
155 
156 	for (i = 0; i < NLOOP; i++) {
157 		ifp = &loif[i];
158 		sprintf(ifp->if_xname, "lo%d", i);
159 		ifp->if_softc = NULL;
160 		ifp->if_mtu = LOMTU;
161 		ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST;
162 		ifp->if_ioctl = loioctl;
163 		ifp->if_output = looutput;
164 #ifdef ALTQ
165 		ifp->if_start = lostart;
166 #endif
167 		ifp->if_type = IFT_LOOP;
168 		ifp->if_hdrlen = 0;
169 		ifp->if_addrlen = 0;
170 		ifp->if_dlt = DLT_NULL;
171 		IFQ_SET_READY(&ifp->if_snd);
172 		if_attach(ifp);
173 		if_alloc_sadl(ifp);
174 #if NBPFILTER > 0
175 		bpfattach(ifp, DLT_NULL, sizeof(u_int));
176 #endif
177 	}
178 }
179 
180 int
181 looutput(ifp, m, dst, rt)
182 	struct ifnet *ifp;
183 	struct mbuf *m;
184 	struct sockaddr *dst;
185 	struct rtentry *rt;
186 {
187 	int s, isr;
188 	struct ifqueue *ifq = 0;
189 
190 	if ((m->m_flags & M_PKTHDR) == 0)
191 		panic("looutput: no header mbuf");
192 #if NBPFILTER > 0
193 	if (ifp->if_bpf && (ifp->if_flags & IFF_LOOPBACK)) {
194 		/*
195 		 * We need to prepend the address family as
196 		 * a four byte field.  Cons up a dummy header
197 		 * to pacify bpf.  This is safe because bpf
198 		 * will only read from the mbuf (i.e., it won't
199 		 * try to free it or keep a pointer to it).
200 		 */
201 		struct mbuf m0;
202 		u_int32_t af = dst->sa_family;
203 
204 		m0.m_next = m;
205 		m0.m_len = 4;
206 		m0.m_data = (char *)&af;
207 
208 		bpf_mtap(ifp->if_bpf, &m0);
209 	}
210 #endif
211 	m->m_pkthdr.rcvif = ifp;
212 
213 	if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
214 		m_freem(m);
215 		return (rt->rt_flags & RTF_BLACKHOLE ? 0 :
216 			rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
217 	}
218 
219 #ifndef PULLDOWN_TEST
220 	/*
221 	 * KAME requires that the packet to be contiguous on the
222 	 * mbuf.  We need to make that sure.
223 	 * this kind of code should be avoided.
224 	 * XXX other conditions to avoid running this part?
225 	 */
226 	if (m->m_len != m->m_pkthdr.len) {
227 		struct mbuf *n = NULL;
228 		int maxlen;
229 
230 		MGETHDR(n, M_DONTWAIT, MT_HEADER);
231 		maxlen = MHLEN;
232 		if (n)
233 			M_COPY_PKTHDR(n, m);
234 		if (n && m->m_pkthdr.len > maxlen) {
235 			MCLGET(n, M_DONTWAIT);
236 			maxlen = MCLBYTES;
237 			if ((n->m_flags & M_EXT) == 0) {
238 				m_free(n);
239 				n = NULL;
240 			}
241 		}
242 		if (!n) {
243 			printf("looutput: mbuf allocation failed\n");
244 			m_freem(m);
245 			return ENOBUFS;
246 		}
247 
248 		if (m->m_pkthdr.len <= maxlen) {
249 			m_copydata(m, 0, m->m_pkthdr.len, mtod(n, caddr_t));
250 			n->m_len = m->m_pkthdr.len;
251 			n->m_next = NULL;
252 			m_freem(m);
253 		} else {
254 			m_copydata(m, 0, maxlen, mtod(n, caddr_t));
255 			m_adj(m, maxlen);
256 			n->m_len = maxlen;
257 			n->m_next = m;
258 			m->m_flags &= ~M_PKTHDR;
259 		}
260 		m = n;
261 	}
262 #if 0
263 	if (m && m->m_next != NULL) {
264 		printf("loop: not contiguous...\n");
265 		m_freem(m);
266 		return ENOBUFS;
267 	}
268 #endif
269 #endif
270 
271 	ifp->if_opackets++;
272 	ifp->if_obytes += m->m_pkthdr.len;
273 
274 #ifdef ALTQ
275 	/*
276 	 * ALTQ on the loopback interface is just for debugging.  It's
277 	 * used only for loopback interfaces, not for a simplex interface.
278 	 */
279 	if ((ALTQ_IS_ENABLED(&ifp->if_snd) || TBR_IS_ENABLED(&ifp->if_snd)) &&
280 	    ifp->if_start == lostart) {
281 		struct altq_pktattr pktattr;
282 		int error;
283 
284 		/*
285 		 * If the queueing discipline needs packet classification,
286 		 * do it before prepending the link headers.
287 		 */
288 		IFQ_CLASSIFY(&ifp->if_snd, m, dst->sa_family, &pktattr);
289 
290 		M_PREPEND(m, sizeof(uint32_t), M_DONTWAIT);
291 		if (m == NULL)
292 			return (ENOBUFS);
293 		*(mtod(m, uint32_t *)) = dst->sa_family;
294 
295 		s = splnet();
296 		IFQ_ENQUEUE(&ifp->if_snd, m, &pktattr, error);
297 		(*ifp->if_start)(ifp);
298 		splx(s);
299 		return (error);
300 	}
301 #endif /* ALTQ */
302 
303 	switch (dst->sa_family) {
304 
305 #ifdef INET
306 	case AF_INET:
307 		ifq = &ipintrq;
308 		isr = NETISR_IP;
309 		break;
310 #endif
311 #ifdef INET6
312 	case AF_INET6:
313 		m->m_flags |= M_LOOP;
314 		ifq = &ip6intrq;
315 		isr = NETISR_IPV6;
316 		break;
317 #endif
318 #ifdef NS
319 	case AF_NS:
320 		ifq = &nsintrq;
321 		isr = NETISR_NS;
322 		break;
323 #endif
324 #ifdef ISO
325 	case AF_ISO:
326 		ifq = &clnlintrq;
327 		isr = NETISR_ISO;
328 		break;
329 #endif
330 #ifdef IPX
331 	case AF_IPX:
332 		ifq = &ipxintrq;
333 		isr = NETISR_IPX;
334 		break;
335 #endif
336 #ifdef NETATALK
337 	case AF_APPLETALK:
338 	        ifq = &atintrq2;
339 		isr = NETISR_ATALK;
340 		break;
341 #endif
342 	default:
343 		printf("%s: can't handle af%d\n", ifp->if_xname,
344 		    dst->sa_family);
345 		m_freem(m);
346 		return (EAFNOSUPPORT);
347 	}
348 	s = splnet();
349 	if (IF_QFULL(ifq)) {
350 		IF_DROP(ifq);
351 		m_freem(m);
352 		splx(s);
353 		return (ENOBUFS);
354 	}
355 	IF_ENQUEUE(ifq, m);
356 	schednetisr(isr);
357 	ifp->if_ipackets++;
358 	ifp->if_ibytes += m->m_pkthdr.len;
359 	splx(s);
360 	return (0);
361 }
362 
363 #ifdef ALTQ
364 void
365 lostart(struct ifnet *ifp)
366 {
367 	struct ifqueue *ifq;
368 	struct mbuf *m;
369 	uint32_t af;
370 	int s, isr;
371 
372 	for (;;) {
373 		IFQ_DEQUEUE(&ifp->if_snd, m);
374 		if (m == NULL)
375 			return;
376 
377 		af = *(mtod(m, uint32_t *));
378 		m_adj(m, sizeof(uint32_t));
379 
380 		switch (af) {
381 #ifdef INET
382 		case AF_INET:
383 			ifq = &ipintrq;
384 			isr = NETISR_IP;
385 			break;
386 #endif
387 #ifdef INET6
388 		case AF_INET6:
389 			m->m_flags |= M_LOOP;
390 			ifq = &ip6intrq;
391 			isr = NETISR_IPV6;
392 			break;
393 #endif
394 #ifdef IPX
395 		case AF_IPX:
396 			ifq = &ipxintrq;
397 			isr = NETISR_IPX;
398 			break;
399 #endif
400 #ifdef NS
401 		case AF_NS:
402 			ifq = &nsintrq;
403 			isr = NETISR_NS;
404 			break;
405 #endif
406 #ifdef ISO
407 		case AF_ISO:
408 			ifq = &clnlintrq;
409 			isr = NETISR_ISO;
410 			break;
411 #endif
412 #ifdef NETATALK
413 		case AF_APPLETALK:
414 			ifq = &atintrq2;
415 			isr = NETISR_ATALK;
416 			break;
417 #endif
418 		default:
419 			printf("%s: can't handle af%d\n", ifp->if_xname, af);
420 			m_freem(m);
421 			return;
422 		}
423 
424 		s = splnet();
425 		if (IF_QFULL(ifq)) {
426 			IF_DROP(ifq);
427 			splx(s);
428 			m_freem(m);
429 			return;
430 		}
431 		IF_ENQUEUE(ifq, m);
432 		schednetisr(isr);
433 		ifp->if_ipackets++;
434 		ifp->if_ibytes += m->m_pkthdr.len;
435 		splx(s);
436 	}
437 }
438 #endif /* ALTQ */
439 
440 /* ARGSUSED */
441 void
442 lortrequest(cmd, rt, info)
443 	int cmd;
444 	struct rtentry *rt;
445 	struct rt_addrinfo *info;
446 {
447 
448 	if (rt)
449 		rt->rt_rmx.rmx_mtu = LOMTU;
450 }
451 
452 /*
453  * Process an ioctl request.
454  */
455 /* ARGSUSED */
456 int
457 loioctl(ifp, cmd, data)
458 	struct ifnet *ifp;
459 	u_long cmd;
460 	caddr_t data;
461 {
462 	struct ifaddr *ifa;
463 	struct ifreq *ifr;
464 	int error = 0;
465 
466 	switch (cmd) {
467 
468 	case SIOCSIFADDR:
469 		ifp->if_flags |= IFF_UP;
470 		ifa = (struct ifaddr *)data;
471 		if (ifa != 0 /*&& ifa->ifa_addr->sa_family == AF_ISO*/)
472 			ifa->ifa_rtrequest = lortrequest;
473 		/*
474 		 * Everything else is done at a higher level.
475 		 */
476 		break;
477 
478 	case SIOCADDMULTI:
479 	case SIOCDELMULTI:
480 		ifr = (struct ifreq *)data;
481 		if (ifr == 0) {
482 			error = EAFNOSUPPORT;		/* XXX */
483 			break;
484 		}
485 		switch (ifr->ifr_addr.sa_family) {
486 
487 #ifdef INET
488 		case AF_INET:
489 			break;
490 #endif
491 #ifdef INET6
492 		case AF_INET6:
493 			break;
494 #endif
495 
496 		default:
497 			error = EAFNOSUPPORT;
498 			break;
499 		}
500 		break;
501 
502 	default:
503 		error = EINVAL;
504 	}
505 	return (error);
506 }
507