1/* $NetBSD: if_loop.c,v 1.93 2016/11/22 02:06:00 ozaki-r 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 1.93 2016/11/22 02:06:00 ozaki-r Exp $");
69
70#ifdef _KERNEL_OPT
71#include "opt_inet.h"
72#include "opt_atalk.h"
73#include "opt_mbuftrace.h"
74#include "opt_mpls.h"
75#include "opt_net_mpsafe.h"
76#endif
77
78#include <sys/param.h>
79#include <sys/systm.h>
80#include <sys/kernel.h>
81#include <sys/mbuf.h>
82#include <sys/socket.h>
83#include <sys/errno.h>
84#include <sys/ioctl.h>
85#include <sys/time.h>
86#include <sys/device.h>
87#include <sys/module.h>
88
89#include <sys/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/in_offload.h>
101#include <netinet/ip.h>
102#endif
103
104#ifdef INET6
105#ifndef INET
106#include <netinet/in.h>
107#endif
108#include <netinet6/in6_var.h>
109#include <netinet6/in6_offload.h>
110#include <netinet/ip6.h>
111#endif
112
113#ifdef MPLS
114#include <netmpls/mpls.h>
115#include <netmpls/mpls_var.h>
116#endif
117
118#ifdef NETATALK
119#include <netatalk/at.h>
120#include <netatalk/at_var.h>
121#endif
122
123#include <net/bpf.h>
124
125#if defined(LARGE_LOMTU)
126#define LOMTU (131072 + MHLEN + MLEN)
127#define LOMTU_MAX LOMTU
128#else
129#define LOMTU (32768 + MHLEN + MLEN)
130#define LOMTU_MAX (65536 + MHLEN + MLEN)
131#endif
132
133#ifdef ALTQ
134static void lostart(struct ifnet *);
135#endif
136
137static int loop_clone_create(struct if_clone *, int);
138static int loop_clone_destroy(struct ifnet *);
139
140static void loop_rtrequest(int, struct rtentry *, const struct rt_addrinfo *);
141
142static struct if_clone loop_cloner =
143 IF_CLONE_INITIALIZER("lo", loop_clone_create, loop_clone_destroy);
144
145void
146loopattach(int n)
147{
148
149 /*
150 * Nothing to do here, initialization is handled by the
151 * module initialization code in loopnit() below).
152 */
153}
154
155void
156loopinit(void)
157{
158
159 if (lo0ifp != NULL) /* can happen in rump kernel */
160 return;
161
162 (void)loop_clone_create(&loop_cloner, 0); /* lo0 always exists */
163 if_clone_attach(&loop_cloner);
164}
165
166static int
167loopdetach(void)
168{
169 /* no detach for now; we don't allow lo0 to be deleted */
170 return EBUSY;
171}
172
173static int
174loop_clone_create(struct if_clone *ifc, int unit)
175{
176 struct ifnet *ifp;
177
178 ifp = if_alloc(IFT_LOOP);
179
180 if_initname(ifp, ifc->ifc_name, unit);
181
182 ifp->if_mtu = LOMTU;
183 ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST | IFF_RUNNING;
184 ifp->if_extflags = IFEF_OUTPUT_MPSAFE;
185 ifp->if_ioctl = loioctl;
186 ifp->if_output = looutput;
187#ifdef ALTQ
188 ifp->if_start = lostart;
189#endif
190 ifp->if_type = IFT_LOOP;
191 ifp->if_hdrlen = 0;
192 ifp->if_addrlen = 0;
193 ifp->if_dlt = DLT_NULL;
194 IFQ_SET_READY(&ifp->if_snd);
195 if (unit == 0)
196 lo0ifp = ifp;
197 if_attach(ifp);
198 if_alloc_sadl(ifp);
199 bpf_attach(ifp, DLT_NULL, sizeof(u_int));
200#ifdef MBUFTRACE
201 ifp->if_mowner = malloc(sizeof(struct mowner), M_DEVBUF,
202 M_WAITOK | M_ZERO);
203 strlcpy(ifp->if_mowner->mo_name, ifp->if_xname,
204 sizeof(ifp->if_mowner->mo_name));
205 MOWNER_ATTACH(ifp->if_mowner);
206#endif
207
208 return (0);
209}
210
211static int
212loop_clone_destroy(struct ifnet *ifp)
213{
214
215 if (ifp == lo0ifp)
216 return (EPERM);
217
218#ifdef MBUFTRACE
219 MOWNER_DETACH(ifp->if_mowner);
220 free(ifp->if_mowner, M_DEVBUF);
221#endif
222
223 bpf_detach(ifp);
224 if_detach(ifp);
225
226 if_free(ifp);
227
228 return (0);
229}
230
231int
232looutput(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
233 const struct rtentry *rt)
234{
235 pktqueue_t *pktq = NULL;
236 struct ifqueue *ifq = NULL;
237 int s, isr = -1;
238 int csum_flags;
239 int error = 0;
240 size_t pktlen;
241
242 MCLAIM(m, ifp->if_mowner);
243
244 KERNEL_LOCK(1, NULL);
245
246 if ((m->m_flags & M_PKTHDR) == 0)
247 panic("looutput: no header mbuf");
248 if (ifp->if_flags & IFF_LOOPBACK)
249 bpf_mtap_af(ifp, dst->sa_family, m);
250 m_set_rcvif(m, ifp);
251
252 if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
253 m_freem(m);
254 error = (rt->rt_flags & RTF_BLACKHOLE ? 0 :
255 rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
256 goto out;
257 }
258
259 pktlen = m->m_pkthdr.len;
260 ifp->if_opackets++;
261 ifp->if_obytes += pktlen;
262
263#ifdef ALTQ
264 /*
265 * ALTQ on the loopback interface is just for debugging. It's
266 * used only for loopback interfaces, not for a simplex interface.
267 */
268 if ((ALTQ_IS_ENABLED(&ifp->if_snd) || TBR_IS_ENABLED(&ifp->if_snd)) &&
269 ifp->if_start == lostart) {
270 /*
271 * If the queueing discipline needs packet classification,
272 * do it before prepending the link headers.
273 */
274 IFQ_CLASSIFY(&ifp->if_snd, m, dst->sa_family);
275
276 M_PREPEND(m, sizeof(uint32_t), M_DONTWAIT);
277 if (m == NULL) {
278 error = ENOBUFS;
279 goto out;
280 }
281 *(mtod(m, uint32_t *)) = dst->sa_family;
282
283 error = if_transmit_lock(ifp, m);
284 goto out;
285 }
286#endif /* ALTQ */
287
288 m_tag_delete_nonpersistent(m);
289
290#ifdef MPLS
291 if (rt != NULL && rt_gettag(rt) != NULL &&
292 rt_gettag(rt)->sa_family == AF_MPLS &&
293 (m->m_flags & (M_MCAST | M_BCAST)) == 0) {
294 union mpls_shim msh;
295 msh.s_addr = MPLS_GETSADDR(rt);
296 if (msh.shim.label != MPLS_LABEL_IMPLNULL) {
297 ifq = &mplsintrq;
298 isr = NETISR_MPLS;
299 }
300 }
301 if (isr != NETISR_MPLS)
302#endif
303 switch (dst->sa_family) {
304
305#ifdef INET
306 case AF_INET:
307 csum_flags = m->m_pkthdr.csum_flags;
308 KASSERT((csum_flags & ~(M_CSUM_IPv4|M_CSUM_UDPv4)) == 0);
309 if (csum_flags != 0 && IN_LOOPBACK_NEED_CHECKSUM(csum_flags)) {
310 ip_undefer_csum(m, 0, csum_flags);
311 }
312 m->m_pkthdr.csum_flags = 0;
313 pktq = ip_pktq;
314 break;
315#endif
316#ifdef INET6
317 case AF_INET6:
318 csum_flags = m->m_pkthdr.csum_flags;
319 KASSERT((csum_flags & ~M_CSUM_UDPv6) == 0);
320 if (csum_flags != 0 &&
321 IN6_LOOPBACK_NEED_CHECKSUM(csum_flags)) {
322 ip6_undefer_csum(m, 0, csum_flags);
323 }
324 m->m_pkthdr.csum_flags = 0;
325 m->m_flags |= M_LOOP;
326 pktq = ip6_pktq;
327 break;
328#endif
329#ifdef NETATALK
330 case AF_APPLETALK:
331 ifq = &atintrq2;
332 isr = NETISR_ATALK;
333 break;
334#endif
335 default:
336 printf("%s: can't handle af%d\n", ifp->if_xname,
337 dst->sa_family);
338 m_freem(m);
339 error = EAFNOSUPPORT;
340 goto out;
341 }
342
343 s = splnet();
344 if (__predict_true(pktq)) {
345 error = 0;
346
347 if (__predict_true(pktq_enqueue(pktq, m, 0))) {
348 ifp->if_ipackets++;
349 ifp->if_ibytes += pktlen;
350 } else {
351 m_freem(m);
352 error = ENOBUFS;
353 }
354 splx(s);
355 goto out;
356 }
357 if (IF_QFULL(ifq)) {
358 IF_DROP(ifq);
359 m_freem(m);
360 splx(s);
361 error = ENOBUFS;
362 goto out;
363 }
364 IF_ENQUEUE(ifq, m);
365 schednetisr(isr);
366 ifp->if_ipackets++;
367 ifp->if_ibytes += m->m_pkthdr.len;
368 splx(s);
369out:
370 KERNEL_UNLOCK_ONE(NULL);
371 return error;
372}
373
374#ifdef ALTQ
375static void
376lostart(struct ifnet *ifp)
377{
378 for (;;) {
379 pktqueue_t *pktq = NULL;
380 struct ifqueue *ifq = NULL;
381 struct mbuf *m;
382 size_t pktlen;
383 uint32_t af;
384 int s, isr = 0;
385
386 IFQ_DEQUEUE(&ifp->if_snd, m);
387 if (m == NULL)
388 return;
389
390 af = *(mtod(m, uint32_t *));
391 m_adj(m, sizeof(uint32_t));
392
393 switch (af) {
394#ifdef INET
395 case AF_INET:
396 pktq = ip_pktq;
397 break;
398#endif
399#ifdef INET6
400 case AF_INET6:
401 m->m_flags |= M_LOOP;
402 pktq = ip6_pktq;
403 break;
404#endif
405#ifdef NETATALK
406 case AF_APPLETALK:
407 ifq = &atintrq2;
408 isr = NETISR_ATALK;
409 break;
410#endif
411 default:
412 printf("%s: can't handle af%d\n", ifp->if_xname, af);
413 m_freem(m);
414 return;
415 }
416 pktlen = m->m_pkthdr.len;
417
418 s = splnet();
419 if (__predict_true(pktq)) {
420 if (__predict_false(pktq_enqueue(pktq, m, 0))) {
421 m_freem(m);
422 splx(s);
423 return;
424 }
425 ifp->if_ipackets++;
426 ifp->if_ibytes += pktlen;
427 splx(s);
428 continue;
429 }
430 if (IF_QFULL(ifq)) {
431 IF_DROP(ifq);
432 splx(s);
433 m_freem(m);
434 return;
435 }
436 IF_ENQUEUE(ifq, m);
437 schednetisr(isr);
438 ifp->if_ipackets++;
439 ifp->if_ibytes += pktlen;
440 splx(s);
441 }
442}
443#endif /* ALTQ */
444
445/* ARGSUSED */
446static void
447loop_rtrequest(int cmd, struct rtentry *rt,
448 const struct rt_addrinfo *info)
449{
450
451 if (rt)
452 rt->rt_rmx.rmx_mtu = lo0ifp->if_mtu;
453}
454
455/*
456 * Process an ioctl request.
457 */
458/* ARGSUSED */
459int
460loioctl(struct ifnet *ifp, u_long cmd, void *data)
461{
462 struct ifaddr *ifa;
463 struct ifreq *ifr = data;
464 int error = 0;
465
466 switch (cmd) {
467
468 case SIOCINITIFADDR:
469 ifp->if_flags |= IFF_UP;
470 ifa = (struct ifaddr *)data;
471 if (ifa != NULL)
472 ifa->ifa_rtrequest = loop_rtrequest;
473 /*
474 * Everything else is done at a higher level.
475 */
476 break;
477
478 case SIOCSIFMTU:
479 if ((unsigned)ifr->ifr_mtu > LOMTU_MAX)
480 error = EINVAL;
481 else if ((error = ifioctl_common(ifp, cmd, data)) == ENETRESET){
482 error = 0;
483 }
484 break;
485
486 case SIOCADDMULTI:
487 case SIOCDELMULTI:
488 if (ifr == NULL) {
489 error = EAFNOSUPPORT; /* XXX */
490 break;
491 }
492 switch (ifreq_getaddr(cmd, ifr)->sa_family) {
493
494#ifdef INET
495 case AF_INET:
496 break;
497#endif
498#ifdef INET6
499 case AF_INET6:
500 break;
501#endif
502
503 default:
504 error = EAFNOSUPPORT;
505 break;
506 }
507 break;
508
509 default:
510 error = ifioctl_common(ifp, cmd, data);
511 }
512 return (error);
513}
514
515/*
516 * Module infrastructure
517 */
518#include "if_module.h"
519
520IF_MODULE(MODULE_CLASS_DRIVER, loop, "")
521