xref: /netbsd-src/sys/net/if_loop.c (revision eb7c1594f145c931049e1fd9eb056a5987e87e59)
1 /*	$NetBSD: if_loop.c,v 1.47 2003/08/07 16:32:53 agc 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 1.47 2003/08/07 16:32:53 agc Exp $");
69 
70 #include "opt_inet.h"
71 #include "opt_atalk.h"
72 #include "opt_iso.h"
73 #include "opt_ns.h"
74 #include "opt_ipx.h"
75 #include "opt_mbuftrace.h"
76 
77 #include "bpfilter.h"
78 #include "loop.h"
79 
80 #include <sys/param.h>
81 #include <sys/systm.h>
82 #include <sys/kernel.h>
83 #include <sys/mbuf.h>
84 #include <sys/socket.h>
85 #include <sys/errno.h>
86 #include <sys/ioctl.h>
87 #include <sys/time.h>
88 
89 #include <machine/cpu.h>
90 
91 #include <net/if.h>
92 #include <net/if_types.h>
93 #include <net/netisr.h>
94 #include <net/route.h>
95 
96 #ifdef	INET
97 #include <netinet/in.h>
98 #include <netinet/in_systm.h>
99 #include <netinet/in_var.h>
100 #include <netinet/ip.h>
101 #endif
102 
103 #ifdef INET6
104 #ifndef INET
105 #include <netinet/in.h>
106 #endif
107 #include <netinet6/in6_var.h>
108 #include <netinet/ip6.h>
109 #endif
110 
111 #ifdef NS
112 #include <netns/ns.h>
113 #include <netns/ns_if.h>
114 #endif
115 
116 #ifdef IPX
117 #include <netipx/ipx.h>
118 #include <netipx/ipx_if.h>
119 #endif
120 
121 #ifdef ISO
122 #include <netiso/iso.h>
123 #include <netiso/iso_var.h>
124 #endif
125 
126 #ifdef NETATALK
127 #include <netatalk/at.h>
128 #include <netatalk/at_var.h>
129 #endif
130 
131 #if NBPFILTER > 0
132 #include <net/bpf.h>
133 #endif
134 
135 #if defined(LARGE_LOMTU)
136 #define LOMTU	(131072 +  MHLEN + MLEN)
137 #else
138 #define	LOMTU	(32768 +  MHLEN + MLEN)
139 #endif
140 
141 struct	ifnet loif[NLOOP];
142 #ifdef MBUFTRACE
143 struct	mowner lomowner[NLOOP];
144 #endif
145 
146 #ifdef ALTQ
147 void	lostart(struct ifnet *);
148 #endif
149 
150 void
151 loopattach(n)
152 	int n;
153 {
154 	int i;
155 	struct ifnet *ifp;
156 
157 	for (i = 0; i < NLOOP; i++) {
158 		ifp = &loif[i];
159 		sprintf(ifp->if_xname, "lo%d", i);
160 		ifp->if_softc = NULL;
161 		ifp->if_mtu = LOMTU;
162 		ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST;
163 		ifp->if_ioctl = loioctl;
164 		ifp->if_output = looutput;
165 #ifdef ALTQ
166 		ifp->if_start = lostart;
167 #endif
168 		ifp->if_type = IFT_LOOP;
169 		ifp->if_hdrlen = 0;
170 		ifp->if_addrlen = 0;
171 		ifp->if_dlt = DLT_NULL;
172 		IFQ_SET_READY(&ifp->if_snd);
173 		if_attach(ifp);
174 		if_alloc_sadl(ifp);
175 #if NBPFILTER > 0
176 		bpfattach(ifp, DLT_NULL, sizeof(u_int));
177 #endif
178 #ifdef MBUFTRACE
179 		ifp->if_mowner = &lomowner[i];
180 		strlcpy(ifp->if_mowner->mo_name, ifp->if_xname,
181 		    sizeof(ifp->if_mowner->mo_name));
182 		MOWNER_ATTACH(&lomowner[i]);
183 #endif
184 	}
185 }
186 
187 int
188 looutput(ifp, m, dst, rt)
189 	struct ifnet *ifp;
190 	struct mbuf *m;
191 	struct sockaddr *dst;
192 	struct rtentry *rt;
193 {
194 	int s, isr;
195 	struct ifqueue *ifq = 0;
196 
197 	MCLAIM(m, ifp->if_mowner);
198 	if ((m->m_flags & M_PKTHDR) == 0)
199 		panic("looutput: no header mbuf");
200 #if NBPFILTER > 0
201 	if (ifp->if_bpf && (ifp->if_flags & IFF_LOOPBACK)) {
202 		/*
203 		 * We need to prepend the address family as
204 		 * a four byte field.  Cons up a dummy header
205 		 * to pacify bpf.  This is safe because bpf
206 		 * will only read from the mbuf (i.e., it won't
207 		 * try to free it or keep a pointer to it).
208 		 */
209 		struct mbuf m0;
210 		u_int32_t af = dst->sa_family;
211 
212 		m0.m_flags = 0;
213 		m0.m_next = m;
214 		m0.m_len = 4;
215 		m0.m_data = (char *)&af;
216 
217 		bpf_mtap(ifp->if_bpf, &m0);
218 	}
219 #endif
220 	m->m_pkthdr.rcvif = ifp;
221 
222 	if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
223 		m_freem(m);
224 		return (rt->rt_flags & RTF_BLACKHOLE ? 0 :
225 			rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
226 	}
227 
228 	ifp->if_opackets++;
229 	ifp->if_obytes += m->m_pkthdr.len;
230 
231 #ifdef ALTQ
232 	/*
233 	 * ALTQ on the loopback interface is just for debugging.  It's
234 	 * used only for loopback interfaces, not for a simplex interface.
235 	 */
236 	if ((ALTQ_IS_ENABLED(&ifp->if_snd) || TBR_IS_ENABLED(&ifp->if_snd)) &&
237 	    ifp->if_start == lostart) {
238 		struct altq_pktattr pktattr;
239 		int error;
240 
241 		/*
242 		 * If the queueing discipline needs packet classification,
243 		 * do it before prepending the link headers.
244 		 */
245 		IFQ_CLASSIFY(&ifp->if_snd, m, dst->sa_family, &pktattr);
246 
247 		M_PREPEND(m, sizeof(uint32_t), M_DONTWAIT);
248 		if (m == NULL)
249 			return (ENOBUFS);
250 		*(mtod(m, uint32_t *)) = dst->sa_family;
251 
252 		s = splnet();
253 		IFQ_ENQUEUE(&ifp->if_snd, m, &pktattr, error);
254 		(*ifp->if_start)(ifp);
255 		splx(s);
256 		return (error);
257 	}
258 #endif /* ALTQ */
259 
260 	switch (dst->sa_family) {
261 
262 #ifdef INET
263 	case AF_INET:
264 		ifq = &ipintrq;
265 		isr = NETISR_IP;
266 		break;
267 #endif
268 #ifdef INET6
269 	case AF_INET6:
270 		m->m_flags |= M_LOOP;
271 		ifq = &ip6intrq;
272 		isr = NETISR_IPV6;
273 		break;
274 #endif
275 #ifdef NS
276 	case AF_NS:
277 		ifq = &nsintrq;
278 		isr = NETISR_NS;
279 		break;
280 #endif
281 #ifdef ISO
282 	case AF_ISO:
283 		ifq = &clnlintrq;
284 		isr = NETISR_ISO;
285 		break;
286 #endif
287 #ifdef IPX
288 	case AF_IPX:
289 		ifq = &ipxintrq;
290 		isr = NETISR_IPX;
291 		break;
292 #endif
293 #ifdef NETATALK
294 	case AF_APPLETALK:
295 	        ifq = &atintrq2;
296 		isr = NETISR_ATALK;
297 		break;
298 #endif
299 	default:
300 		printf("%s: can't handle af%d\n", ifp->if_xname,
301 		    dst->sa_family);
302 		m_freem(m);
303 		return (EAFNOSUPPORT);
304 	}
305 	s = splnet();
306 	if (IF_QFULL(ifq)) {
307 		IF_DROP(ifq);
308 		m_freem(m);
309 		splx(s);
310 		return (ENOBUFS);
311 	}
312 	IF_ENQUEUE(ifq, m);
313 	schednetisr(isr);
314 	ifp->if_ipackets++;
315 	ifp->if_ibytes += m->m_pkthdr.len;
316 	splx(s);
317 	return (0);
318 }
319 
320 #ifdef ALTQ
321 void
322 lostart(struct ifnet *ifp)
323 {
324 	struct ifqueue *ifq;
325 	struct mbuf *m;
326 	uint32_t af;
327 	int s, isr;
328 
329 	for (;;) {
330 		IFQ_DEQUEUE(&ifp->if_snd, m);
331 		if (m == NULL)
332 			return;
333 
334 		af = *(mtod(m, uint32_t *));
335 		m_adj(m, sizeof(uint32_t));
336 
337 		switch (af) {
338 #ifdef INET
339 		case AF_INET:
340 			ifq = &ipintrq;
341 			isr = NETISR_IP;
342 			break;
343 #endif
344 #ifdef INET6
345 		case AF_INET6:
346 			m->m_flags |= M_LOOP;
347 			ifq = &ip6intrq;
348 			isr = NETISR_IPV6;
349 			break;
350 #endif
351 #ifdef IPX
352 		case AF_IPX:
353 			ifq = &ipxintrq;
354 			isr = NETISR_IPX;
355 			break;
356 #endif
357 #ifdef NS
358 		case AF_NS:
359 			ifq = &nsintrq;
360 			isr = NETISR_NS;
361 			break;
362 #endif
363 #ifdef ISO
364 		case AF_ISO:
365 			ifq = &clnlintrq;
366 			isr = NETISR_ISO;
367 			break;
368 #endif
369 #ifdef NETATALK
370 		case AF_APPLETALK:
371 			ifq = &atintrq2;
372 			isr = NETISR_ATALK;
373 			break;
374 #endif
375 		default:
376 			printf("%s: can't handle af%d\n", ifp->if_xname, af);
377 			m_freem(m);
378 			return;
379 		}
380 
381 		s = splnet();
382 		if (IF_QFULL(ifq)) {
383 			IF_DROP(ifq);
384 			splx(s);
385 			m_freem(m);
386 			return;
387 		}
388 		IF_ENQUEUE(ifq, m);
389 		schednetisr(isr);
390 		ifp->if_ipackets++;
391 		ifp->if_ibytes += m->m_pkthdr.len;
392 		splx(s);
393 	}
394 }
395 #endif /* ALTQ */
396 
397 /* ARGSUSED */
398 void
399 lortrequest(cmd, rt, info)
400 	int cmd;
401 	struct rtentry *rt;
402 	struct rt_addrinfo *info;
403 {
404 
405 	if (rt)
406 		rt->rt_rmx.rmx_mtu = LOMTU;
407 }
408 
409 /*
410  * Process an ioctl request.
411  */
412 /* ARGSUSED */
413 int
414 loioctl(ifp, cmd, data)
415 	struct ifnet *ifp;
416 	u_long cmd;
417 	caddr_t data;
418 {
419 	struct ifaddr *ifa;
420 	struct ifreq *ifr;
421 	int error = 0;
422 
423 	switch (cmd) {
424 
425 	case SIOCSIFADDR:
426 		ifp->if_flags |= IFF_UP;
427 		ifa = (struct ifaddr *)data;
428 		if (ifa != 0 /*&& ifa->ifa_addr->sa_family == AF_ISO*/)
429 			ifa->ifa_rtrequest = lortrequest;
430 		/*
431 		 * Everything else is done at a higher level.
432 		 */
433 		break;
434 
435 	case SIOCADDMULTI:
436 	case SIOCDELMULTI:
437 		ifr = (struct ifreq *)data;
438 		if (ifr == 0) {
439 			error = EAFNOSUPPORT;		/* XXX */
440 			break;
441 		}
442 		switch (ifr->ifr_addr.sa_family) {
443 
444 #ifdef INET
445 		case AF_INET:
446 			break;
447 #endif
448 #ifdef INET6
449 		case AF_INET6:
450 			break;
451 #endif
452 
453 		default:
454 			error = EAFNOSUPPORT;
455 			break;
456 		}
457 		break;
458 
459 	default:
460 		error = EINVAL;
461 	}
462 	return (error);
463 }
464