FreeBSD/Linux Kernel Cross Reference
sys/net/if_epair.c
1 /*-
2 * Copyright (c) 2008 The FreeBSD Foundation
3 * Copyright (c) 2009-2010 Bjoern A. Zeeb <bz@FreeBSD.org>
4 * All rights reserved.
5 *
6 * This software was developed by CK Software GmbH under sponsorship
7 * from the FreeBSD Foundation.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 */
30
31 /*
32 * A pair of virtual back-to-back connected ethernet like interfaces
33 * (``two interfaces with a virtual cross-over cable'').
34 *
35 * This is mostly intended to be used to provide connectivity between
36 * different virtual network stack instances.
37 */
38 /*
39 * Things to re-think once we have more experience:
40 * - ifp->if_reassign function once we can test with vimage. Depending on
41 * how if_vmove() is going to be improved.
42 * - Real random etheraddrs that are checked to be uniquish; we would need
43 * to re-do them in case we move the interface between network stacks
44 * in a private if_reassign function.
45 * In case we bridge to a real interface/network or between indepedent
46 * epairs on multiple stacks/machines, we may need this.
47 * For now let the user handle that case.
48 */
49
50 #include <sys/cdefs.h>
51 __FBSDID("$FreeBSD: releng/11.2/sys/net/if_epair.c 328391 2018-01-25 07:19:07Z pkelsey $");
52
53 #include <sys/param.h>
54 #include <sys/kernel.h>
55 #include <sys/malloc.h>
56 #include <sys/mbuf.h>
57 #include <sys/module.h>
58 #include <sys/refcount.h>
59 #include <sys/queue.h>
60 #include <sys/smp.h>
61 #include <sys/socket.h>
62 #include <sys/sockio.h>
63 #include <sys/sysctl.h>
64 #include <sys/types.h>
65
66 #include <net/bpf.h>
67 #include <net/ethernet.h>
68 #include <net/if.h>
69 #include <net/if_var.h>
70 #include <net/if_clone.h>
71 #include <net/if_media.h>
72 #include <net/if_var.h>
73 #include <net/if_types.h>
74 #include <net/netisr.h>
75 #include <net/vnet.h>
76
77 SYSCTL_DECL(_net_link);
78 static SYSCTL_NODE(_net_link, OID_AUTO, epair, CTLFLAG_RW, 0, "epair sysctl");
79
80 #ifdef EPAIR_DEBUG
81 static int epair_debug = 0;
82 SYSCTL_INT(_net_link_epair, OID_AUTO, epair_debug, CTLFLAG_RW,
83 &epair_debug, 0, "if_epair(4) debugging.");
84 #define DPRINTF(fmt, arg...) \
85 if (epair_debug) \
86 printf("[%s:%d] " fmt, __func__, __LINE__, ##arg)
87 #else
88 #define DPRINTF(fmt, arg...)
89 #endif
90
91 static void epair_nh_sintr(struct mbuf *);
92 static struct mbuf *epair_nh_m2cpuid(struct mbuf *, uintptr_t, u_int *);
93 static void epair_nh_drainedcpu(u_int);
94
95 static void epair_start_locked(struct ifnet *);
96 static int epair_media_change(struct ifnet *);
97 static void epair_media_status(struct ifnet *, struct ifmediareq *);
98
99 static int epair_clone_match(struct if_clone *, const char *);
100 static int epair_clone_create(struct if_clone *, char *, size_t, caddr_t);
101 static int epair_clone_destroy(struct if_clone *, struct ifnet *);
102
103 static const char epairname[] = "epair";
104
105 /* Netisr related definitions and sysctl. */
106 static struct netisr_handler epair_nh = {
107 .nh_name = epairname,
108 .nh_proto = NETISR_EPAIR,
109 .nh_policy = NETISR_POLICY_CPU,
110 .nh_handler = epair_nh_sintr,
111 .nh_m2cpuid = epair_nh_m2cpuid,
112 .nh_drainedcpu = epair_nh_drainedcpu,
113 };
114
115 static int
116 sysctl_epair_netisr_maxqlen(SYSCTL_HANDLER_ARGS)
117 {
118 int error, qlimit;
119
120 netisr_getqlimit(&epair_nh, &qlimit);
121 error = sysctl_handle_int(oidp, &qlimit, 0, req);
122 if (error || !req->newptr)
123 return (error);
124 if (qlimit < 1)
125 return (EINVAL);
126 return (netisr_setqlimit(&epair_nh, qlimit));
127 }
128 SYSCTL_PROC(_net_link_epair, OID_AUTO, netisr_maxqlen, CTLTYPE_INT|CTLFLAG_RW,
129 0, 0, sysctl_epair_netisr_maxqlen, "I",
130 "Maximum if_epair(4) netisr \"hw\" queue length");
131
132 struct epair_softc {
133 struct ifnet *ifp; /* This ifp. */
134 struct ifnet *oifp; /* other ifp of pair. */
135 struct ifmedia media; /* Media config (fake). */
136 u_int refcount; /* # of mbufs in flight. */
137 u_int cpuid; /* CPU ID assigned upon creation. */
138 void (*if_qflush)(struct ifnet *);
139 /* Original if_qflush routine. */
140 };
141
142 /*
143 * Per-CPU list of ifps with data in the ifq that needs to be flushed
144 * to the netisr ``hw'' queue before we allow any further direct queuing
145 * to the ``hw'' queue.
146 */
147 struct epair_ifp_drain {
148 STAILQ_ENTRY(epair_ifp_drain) ifp_next;
149 struct ifnet *ifp;
150 };
151 STAILQ_HEAD(eid_list, epair_ifp_drain);
152
153 #define EPAIR_LOCK_INIT(dpcpu) mtx_init(&(dpcpu)->if_epair_mtx, \
154 "if_epair", NULL, MTX_DEF)
155 #define EPAIR_LOCK_DESTROY(dpcpu) mtx_destroy(&(dpcpu)->if_epair_mtx)
156 #define EPAIR_LOCK_ASSERT(dpcpu) mtx_assert(&(dpcpu)->if_epair_mtx, \
157 MA_OWNED)
158 #define EPAIR_LOCK(dpcpu) mtx_lock(&(dpcpu)->if_epair_mtx)
159 #define EPAIR_UNLOCK(dpcpu) mtx_unlock(&(dpcpu)->if_epair_mtx)
160
161 #ifdef INVARIANTS
162 #define EPAIR_REFCOUNT_INIT(r, v) refcount_init((r), (v))
163 #define EPAIR_REFCOUNT_AQUIRE(r) refcount_acquire((r))
164 #define EPAIR_REFCOUNT_RELEASE(r) refcount_release((r))
165 #define EPAIR_REFCOUNT_ASSERT(a, p) KASSERT(a, p)
166 #else
167 #define EPAIR_REFCOUNT_INIT(r, v)
168 #define EPAIR_REFCOUNT_AQUIRE(r)
169 #define EPAIR_REFCOUNT_RELEASE(r)
170 #define EPAIR_REFCOUNT_ASSERT(a, p)
171 #endif
172
173 static MALLOC_DEFINE(M_EPAIR, epairname,
174 "Pair of virtual cross-over connected Ethernet-like interfaces");
175
176 static VNET_DEFINE(struct if_clone *, epair_cloner);
177 #define V_epair_cloner VNET(epair_cloner)
178
179 /*
180 * DPCPU area and functions.
181 */
182 struct epair_dpcpu {
183 struct mtx if_epair_mtx; /* Per-CPU locking. */
184 int epair_drv_flags; /* Per-CPU ``hw'' drv flags. */
185 struct eid_list epair_ifp_drain_list; /* Per-CPU list of ifps with
186 * data in the ifq. */
187 };
188 DPCPU_DEFINE(struct epair_dpcpu, epair_dpcpu);
189
190 static void
191 epair_dpcpu_init(void)
192 {
193 struct epair_dpcpu *epair_dpcpu;
194 struct eid_list *s;
195 u_int cpuid;
196
197 CPU_FOREACH(cpuid) {
198 epair_dpcpu = DPCPU_ID_PTR(cpuid, epair_dpcpu);
199
200 /* Initialize per-cpu lock. */
201 EPAIR_LOCK_INIT(epair_dpcpu);
202
203 /* Driver flags are per-cpu as are our netisr "hw" queues. */
204 epair_dpcpu->epair_drv_flags = 0;
205
206 /*
207 * Initialize per-cpu drain list.
208 * Manually do what STAILQ_HEAD_INITIALIZER would do.
209 */
210 s = &epair_dpcpu->epair_ifp_drain_list;
211 s->stqh_first = NULL;
212 s->stqh_last = &s->stqh_first;
213 }
214 }
215
216 static void
217 epair_dpcpu_detach(void)
218 {
219 struct epair_dpcpu *epair_dpcpu;
220 u_int cpuid;
221
222 CPU_FOREACH(cpuid) {
223 epair_dpcpu = DPCPU_ID_PTR(cpuid, epair_dpcpu);
224
225 /* Destroy per-cpu lock. */
226 EPAIR_LOCK_DESTROY(epair_dpcpu);
227 }
228 }
229
230 /*
231 * Helper functions.
232 */
233 static u_int
234 cpuid_from_ifp(struct ifnet *ifp)
235 {
236 struct epair_softc *sc;
237
238 if (ifp == NULL)
239 return (0);
240 sc = ifp->if_softc;
241
242 return (sc->cpuid);
243 }
244
245 /*
246 * Netisr handler functions.
247 */
248 static void
249 epair_nh_sintr(struct mbuf *m)
250 {
251 struct ifnet *ifp;
252 struct epair_softc *sc;
253
254 ifp = m->m_pkthdr.rcvif;
255 (*ifp->if_input)(ifp, m);
256 sc = ifp->if_softc;
257 EPAIR_REFCOUNT_RELEASE(&sc->refcount);
258 EPAIR_REFCOUNT_ASSERT((int)sc->refcount >= 1,
259 ("%s: ifp=%p sc->refcount not >= 1: %d",
260 __func__, ifp, sc->refcount));
261 DPRINTF("ifp=%p refcount=%u\n", ifp, sc->refcount);
262 }
263
264 static struct mbuf *
265 epair_nh_m2cpuid(struct mbuf *m, uintptr_t source, u_int *cpuid)
266 {
267
268 *cpuid = cpuid_from_ifp(m->m_pkthdr.rcvif);
269
270 return (m);
271 }
272
273 static void
274 epair_nh_drainedcpu(u_int cpuid)
275 {
276 struct epair_dpcpu *epair_dpcpu;
277 struct epair_ifp_drain *elm, *tvar;
278 struct ifnet *ifp;
279
280 epair_dpcpu = DPCPU_ID_PTR(cpuid, epair_dpcpu);
281 EPAIR_LOCK(epair_dpcpu);
282 /*
283 * Assume our "hw" queue and possibly ifq will be emptied
284 * again. In case we will overflow the "hw" queue while
285 * draining, epair_start_locked will set IFF_DRV_OACTIVE
286 * again and we will stop and return.
287 */
288 STAILQ_FOREACH_SAFE(elm, &epair_dpcpu->epair_ifp_drain_list,
289 ifp_next, tvar) {
290 ifp = elm->ifp;
291 epair_dpcpu->epair_drv_flags &= ~IFF_DRV_OACTIVE;
292 ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
293 epair_start_locked(ifp);
294
295 IFQ_LOCK(&ifp->if_snd);
296 if (IFQ_IS_EMPTY(&ifp->if_snd)) {
297 struct epair_softc *sc;
298
299 STAILQ_REMOVE(&epair_dpcpu->epair_ifp_drain_list,
300 elm, epair_ifp_drain, ifp_next);
301 /* The cached ifp goes off the list. */
302 sc = ifp->if_softc;
303 EPAIR_REFCOUNT_RELEASE(&sc->refcount);
304 EPAIR_REFCOUNT_ASSERT((int)sc->refcount >= 1,
305 ("%s: ifp=%p sc->refcount not >= 1: %d",
306 __func__, ifp, sc->refcount));
307 free(elm, M_EPAIR);
308 }
309 IFQ_UNLOCK(&ifp->if_snd);
310
311 if ((ifp->if_drv_flags & IFF_DRV_OACTIVE) != 0) {
312 /* Our "hw"q overflew again. */
313 epair_dpcpu->epair_drv_flags |= IFF_DRV_OACTIVE;
314 DPRINTF("hw queue length overflow at %u\n",
315 epair_nh.nh_qlimit);
316 break;
317 }
318 }
319 EPAIR_UNLOCK(epair_dpcpu);
320 }
321
322 /*
323 * Network interface (`if') related functions.
324 */
325 static void
326 epair_remove_ifp_from_draining(struct ifnet *ifp)
327 {
328 struct epair_dpcpu *epair_dpcpu;
329 struct epair_ifp_drain *elm, *tvar;
330 u_int cpuid;
331
332 CPU_FOREACH(cpuid) {
333 epair_dpcpu = DPCPU_ID_PTR(cpuid, epair_dpcpu);
334 EPAIR_LOCK(epair_dpcpu);
335 STAILQ_FOREACH_SAFE(elm, &epair_dpcpu->epair_ifp_drain_list,
336 ifp_next, tvar) {
337 if (ifp == elm->ifp) {
338 struct epair_softc *sc;
339
340 STAILQ_REMOVE(
341 &epair_dpcpu->epair_ifp_drain_list, elm,
342 epair_ifp_drain, ifp_next);
343 /* The cached ifp goes off the list. */
344 sc = ifp->if_softc;
345 EPAIR_REFCOUNT_RELEASE(&sc->refcount);
346 EPAIR_REFCOUNT_ASSERT((int)sc->refcount >= 1,
347 ("%s: ifp=%p sc->refcount not >= 1: %d",
348 __func__, ifp, sc->refcount));
349 free(elm, M_EPAIR);
350 }
351 }
352 EPAIR_UNLOCK(epair_dpcpu);
353 }
354 }
355
356 static int
357 epair_add_ifp_for_draining(struct ifnet *ifp)
358 {
359 struct epair_dpcpu *epair_dpcpu;
360 struct epair_softc *sc;
361 struct epair_ifp_drain *elm = NULL;
362
363 sc = ifp->if_softc;
364 epair_dpcpu = DPCPU_ID_PTR(sc->cpuid, epair_dpcpu);
365 EPAIR_LOCK_ASSERT(epair_dpcpu);
366 STAILQ_FOREACH(elm, &epair_dpcpu->epair_ifp_drain_list, ifp_next)
367 if (elm->ifp == ifp)
368 break;
369 /* If the ifp is there already, return success. */
370 if (elm != NULL)
371 return (0);
372
373 elm = malloc(sizeof(struct epair_ifp_drain), M_EPAIR, M_NOWAIT|M_ZERO);
374 if (elm == NULL)
375 return (ENOMEM);
376
377 elm->ifp = ifp;
378 /* Add a reference for the ifp pointer on the list. */
379 EPAIR_REFCOUNT_AQUIRE(&sc->refcount);
380 STAILQ_INSERT_TAIL(&epair_dpcpu->epair_ifp_drain_list, elm, ifp_next);
381
382 return (0);
383 }
384
385 static void
386 epair_start_locked(struct ifnet *ifp)
387 {
388 struct epair_dpcpu *epair_dpcpu;
389 struct mbuf *m;
390 struct epair_softc *sc;
391 struct ifnet *oifp;
392 int error;
393
394 DPRINTF("ifp=%p\n", ifp);
395 sc = ifp->if_softc;
396 epair_dpcpu = DPCPU_ID_PTR(sc->cpuid, epair_dpcpu);
397 EPAIR_LOCK_ASSERT(epair_dpcpu);
398
399 if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0)
400 return;
401 if ((ifp->if_flags & IFF_UP) == 0)
402 return;
403
404 /*
405 * We get packets here from ether_output via if_handoff()
406 * and need to put them into the input queue of the oifp
407 * and call oifp->if_input() via netisr/epair_sintr().
408 */
409 oifp = sc->oifp;
410 sc = oifp->if_softc;
411 for (;;) {
412 IFQ_DEQUEUE(&ifp->if_snd, m);
413 if (m == NULL)
414 break;
415 BPF_MTAP(ifp, m);
416
417 /*
418 * In case the outgoing interface is not usable,
419 * drop the packet.
420 */
421 if ((oifp->if_drv_flags & IFF_DRV_RUNNING) == 0 ||
422 (oifp->if_flags & IFF_UP) ==0) {
423 if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
424 m_freem(m);
425 continue;
426 }
427 DPRINTF("packet %s -> %s\n", ifp->if_xname, oifp->if_xname);
428
429 /*
430 * Add a reference so the interface cannot go while the
431 * packet is in transit as we rely on rcvif to stay valid.
432 */
433 EPAIR_REFCOUNT_AQUIRE(&sc->refcount);
434 m->m_pkthdr.rcvif = oifp;
435 CURVNET_SET_QUIET(oifp->if_vnet);
436 error = netisr_queue(NETISR_EPAIR, m);
437 CURVNET_RESTORE();
438 if (!error) {
439 if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);
440 /* Someone else received the packet. */
441 if_inc_counter(oifp, IFCOUNTER_IPACKETS, 1);
442 } else {
443 /* The packet was freed already. */
444 epair_dpcpu->epair_drv_flags |= IFF_DRV_OACTIVE;
445 ifp->if_drv_flags |= IFF_DRV_OACTIVE;
446 (void) epair_add_ifp_for_draining(ifp);
447 if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
448 EPAIR_REFCOUNT_RELEASE(&sc->refcount);
449 EPAIR_REFCOUNT_ASSERT((int)sc->refcount >= 1,
450 ("%s: ifp=%p sc->refcount not >= 1: %d",
451 __func__, oifp, sc->refcount));
452 }
453 }
454 }
455
456 static void
457 epair_start(struct ifnet *ifp)
458 {
459 struct epair_dpcpu *epair_dpcpu;
460
461 epair_dpcpu = DPCPU_ID_PTR(cpuid_from_ifp(ifp), epair_dpcpu);
462 EPAIR_LOCK(epair_dpcpu);
463 epair_start_locked(ifp);
464 EPAIR_UNLOCK(epair_dpcpu);
465 }
466
467 static int
468 epair_transmit_locked(struct ifnet *ifp, struct mbuf *m)
469 {
470 struct epair_dpcpu *epair_dpcpu;
471 struct epair_softc *sc;
472 struct ifnet *oifp;
473 int error, len;
474 short mflags;
475
476 DPRINTF("ifp=%p m=%p\n", ifp, m);
477 sc = ifp->if_softc;
478 epair_dpcpu = DPCPU_ID_PTR(sc->cpuid, epair_dpcpu);
479 EPAIR_LOCK_ASSERT(epair_dpcpu);
480
481 if (m == NULL)
482 return (0);
483
484 /*
485 * We are not going to use the interface en/dequeue mechanism
486 * on the TX side. We are called from ether_output_frame()
487 * and will put the packet into the incoming queue of the
488 * other interface of our pair via the netsir.
489 */
490 if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) {
491 m_freem(m);
492 return (ENXIO);
493 }
494 if ((ifp->if_flags & IFF_UP) == 0) {
495 m_freem(m);
496 return (ENETDOWN);
497 }
498
499 BPF_MTAP(ifp, m);
500
501 /*
502 * In case the outgoing interface is not usable,
503 * drop the packet.
504 */
505 oifp = sc->oifp;
506 if ((oifp->if_drv_flags & IFF_DRV_RUNNING) == 0 ||
507 (oifp->if_flags & IFF_UP) ==0) {
508 if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
509 m_freem(m);
510 return (0);
511 }
512 len = m->m_pkthdr.len;
513 mflags = m->m_flags;
514 DPRINTF("packet %s -> %s\n", ifp->if_xname, oifp->if_xname);
515
516 #ifdef ALTQ
517 /* Support ALTQ via the classic if_start() path. */
518 IF_LOCK(&ifp->if_snd);
519 if (ALTQ_IS_ENABLED(&ifp->if_snd)) {
520 ALTQ_ENQUEUE(&ifp->if_snd, m, NULL, error);
521 if (error)
522 if_inc_counter(ifp, IFCOUNTER_OQDROPS, 1);
523 IF_UNLOCK(&ifp->if_snd);
524 if (!error) {
525 if_inc_counter(ifp, IFCOUNTER_OBYTES, len);
526 if (mflags & (M_BCAST|M_MCAST))
527 if_inc_counter(ifp, IFCOUNTER_OMCASTS, 1);
528
529 if ((ifp->if_drv_flags & IFF_DRV_OACTIVE) == 0)
530 epair_start_locked(ifp);
531 else
532 (void)epair_add_ifp_for_draining(ifp);
533 }
534 return (error);
535 }
536 IF_UNLOCK(&ifp->if_snd);
537 #endif
538
539 if ((epair_dpcpu->epair_drv_flags & IFF_DRV_OACTIVE) != 0) {
540 /*
541 * Our hardware queue is full, try to fall back
542 * queuing to the ifq but do not call ifp->if_start.
543 * Either we are lucky or the packet is gone.
544 */
545 IFQ_ENQUEUE(&ifp->if_snd, m, error);
546 if (!error)
547 (void)epair_add_ifp_for_draining(ifp);
548 return (error);
549 }
550 sc = oifp->if_softc;
551 /*
552 * Add a reference so the interface cannot go while the
553 * packet is in transit as we rely on rcvif to stay valid.
554 */
555 EPAIR_REFCOUNT_AQUIRE(&sc->refcount);
556 m->m_pkthdr.rcvif = oifp;
557 CURVNET_SET_QUIET(oifp->if_vnet);
558 error = netisr_queue(NETISR_EPAIR, m);
559 CURVNET_RESTORE();
560 if (!error) {
561 if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);
562 /*
563 * IFQ_HANDOFF_ADJ/ip_handoff() update statistics,
564 * but as we bypass all this we have to duplicate
565 * the logic another time.
566 */
567 if_inc_counter(ifp, IFCOUNTER_OBYTES, len);
568 if (mflags & (M_BCAST|M_MCAST))
569 if_inc_counter(ifp, IFCOUNTER_OMCASTS, 1);
570 /* Someone else received the packet. */
571 if_inc_counter(oifp, IFCOUNTER_IPACKETS, 1);
572 } else {
573 /* The packet was freed already. */
574 epair_dpcpu->epair_drv_flags |= IFF_DRV_OACTIVE;
575 ifp->if_drv_flags |= IFF_DRV_OACTIVE;
576 if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
577 EPAIR_REFCOUNT_RELEASE(&sc->refcount);
578 EPAIR_REFCOUNT_ASSERT((int)sc->refcount >= 1,
579 ("%s: ifp=%p sc->refcount not >= 1: %d",
580 __func__, oifp, sc->refcount));
581 }
582
583 return (error);
584 }
585
586 static int
587 epair_transmit(struct ifnet *ifp, struct mbuf *m)
588 {
589 struct epair_dpcpu *epair_dpcpu;
590 int error;
591
592 epair_dpcpu = DPCPU_ID_PTR(cpuid_from_ifp(ifp), epair_dpcpu);
593 EPAIR_LOCK(epair_dpcpu);
594 error = epair_transmit_locked(ifp, m);
595 EPAIR_UNLOCK(epair_dpcpu);
596 return (error);
597 }
598
599 static void
600 epair_qflush(struct ifnet *ifp)
601 {
602 struct epair_softc *sc;
603
604 sc = ifp->if_softc;
605 KASSERT(sc != NULL, ("%s: ifp=%p, epair_softc gone? sc=%p\n",
606 __func__, ifp, sc));
607 /*
608 * Remove this ifp from all backpointer lists. The interface will not
609 * usable for flushing anyway nor should it have anything to flush
610 * after if_qflush().
611 */
612 epair_remove_ifp_from_draining(ifp);
613
614 if (sc->if_qflush)
615 sc->if_qflush(ifp);
616 }
617
618 static int
619 epair_media_change(struct ifnet *ifp __unused)
620 {
621
622 /* Do nothing. */
623 return (0);
624 }
625
626 static void
627 epair_media_status(struct ifnet *ifp __unused, struct ifmediareq *imr)
628 {
629
630 imr->ifm_status = IFM_AVALID | IFM_ACTIVE;
631 imr->ifm_active = IFM_ETHER | IFM_10G_T | IFM_FDX;
632 }
633
634 static int
635 epair_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
636 {
637 struct epair_softc *sc;
638 struct ifreq *ifr;
639 int error;
640
641 ifr = (struct ifreq *)data;
642 switch (cmd) {
643 case SIOCSIFFLAGS:
644 case SIOCADDMULTI:
645 case SIOCDELMULTI:
646 error = 0;
647 break;
648
649 case SIOCSIFMEDIA:
650 case SIOCGIFMEDIA:
651 sc = ifp->if_softc;
652 error = ifmedia_ioctl(ifp, ifr, &sc->media, cmd);
653 break;
654
655 case SIOCSIFMTU:
656 /* We basically allow all kinds of MTUs. */
657 ifp->if_mtu = ifr->ifr_mtu;
658 error = 0;
659 break;
660
661 default:
662 /* Let the common ethernet handler process this. */
663 error = ether_ioctl(ifp, cmd, data);
664 break;
665 }
666
667 return (error);
668 }
669
670 static void
671 epair_init(void *dummy __unused)
672 {
673 }
674
675
676 /*
677 * Interface cloning functions.
678 * We use our private ones so that we can create/destroy our secondary
679 * device along with the primary one.
680 */
681 static int
682 epair_clone_match(struct if_clone *ifc, const char *name)
683 {
684 const char *cp;
685
686 DPRINTF("name='%s'\n", name);
687
688 /*
689 * Our base name is epair.
690 * Our interfaces will be named epair<n>[ab].
691 * So accept anything of the following list:
692 * - epair
693 * - epair<n>
694 * but not the epair<n>[ab] versions.
695 */
696 if (strncmp(epairname, name, sizeof(epairname)-1) != 0)
697 return (0);
698
699 for (cp = name + sizeof(epairname) - 1; *cp != '\0'; cp++) {
700 if (*cp < '' || *cp > '9')
701 return (0);
702 }
703
704 return (1);
705 }
706
707 static int
708 epair_clone_create(struct if_clone *ifc, char *name, size_t len, caddr_t params)
709 {
710 struct epair_softc *sca, *scb;
711 struct ifnet *ifp;
712 char *dp;
713 int error, unit, wildcard;
714 uint8_t eaddr[ETHER_ADDR_LEN]; /* 00:00:00:00:00:00 */
715
716 /*
717 * We are abusing params to create our second interface.
718 * Actually we already created it and called if_clone_create()
719 * for it to do the official insertion procedure the moment we knew
720 * it cannot fail anymore. So just do attach it here.
721 */
722 if (params) {
723 scb = (struct epair_softc *)params;
724 ifp = scb->ifp;
725 /* Assign a hopefully unique, locally administered etheraddr. */
726 eaddr[0] = 0x02;
727 eaddr[3] = (ifp->if_index >> 8) & 0xff;
728 eaddr[4] = ifp->if_index & 0xff;
729 eaddr[5] = 0x0b;
730 ether_ifattach(ifp, eaddr);
731 /* Correctly set the name for the cloner list. */
732 strlcpy(name, scb->ifp->if_xname, len);
733 return (0);
734 }
735
736 /* Try to see if a special unit was requested. */
737 error = ifc_name2unit(name, &unit);
738 if (error != 0)
739 return (error);
740 wildcard = (unit < 0);
741
742 error = ifc_alloc_unit(ifc, &unit);
743 if (error != 0)
744 return (error);
745
746 /*
747 * If no unit had been given, we need to adjust the ifName.
748 * Also make sure there is space for our extra [ab] suffix.
749 */
750 for (dp = name; *dp != '\0'; dp++);
751 if (wildcard) {
752 error = snprintf(dp, len - (dp - name), "%d", unit);
753 if (error > len - (dp - name) - 1) {
754 /* ifName too long. */
755 ifc_free_unit(ifc, unit);
756 return (ENOSPC);
757 }
758 dp += error;
759 }
760 if (len - (dp - name) - 1 < 1) {
761 /* No space left for our [ab] suffix. */
762 ifc_free_unit(ifc, unit);
763 return (ENOSPC);
764 }
765 *dp = 'b';
766 /* Must not change dp so we can replace 'a' by 'b' later. */
767 *(dp+1) = '\0';
768
769 /* Check if 'a' and 'b' interfaces already exist. */
770 if (ifunit(name) != NULL)
771 return (EEXIST);
772 *dp = 'a';
773 if (ifunit(name) != NULL)
774 return (EEXIST);
775
776 /* Allocate memory for both [ab] interfaces */
777 sca = malloc(sizeof(struct epair_softc), M_EPAIR, M_WAITOK | M_ZERO);
778 EPAIR_REFCOUNT_INIT(&sca->refcount, 1);
779 sca->ifp = if_alloc(IFT_ETHER);
780 if (sca->ifp == NULL) {
781 free(sca, M_EPAIR);
782 ifc_free_unit(ifc, unit);
783 return (ENOSPC);
784 }
785
786 scb = malloc(sizeof(struct epair_softc), M_EPAIR, M_WAITOK | M_ZERO);
787 EPAIR_REFCOUNT_INIT(&scb->refcount, 1);
788 scb->ifp = if_alloc(IFT_ETHER);
789 if (scb->ifp == NULL) {
790 free(scb, M_EPAIR);
791 if_free(sca->ifp);
792 free(sca, M_EPAIR);
793 ifc_free_unit(ifc, unit);
794 return (ENOSPC);
795 }
796
797 /*
798 * Cross-reference the interfaces so we will be able to free both.
799 */
800 sca->oifp = scb->ifp;
801 scb->oifp = sca->ifp;
802
803 /*
804 * Calculate the cpuid for netisr queueing based on the
805 * ifIndex of the interfaces. As long as we cannot configure
806 * this or use cpuset information easily we cannot guarantee
807 * cache locality but we can at least allow parallelism.
808 */
809 sca->cpuid =
810 netisr_get_cpuid(sca->ifp->if_index);
811 scb->cpuid =
812 netisr_get_cpuid(scb->ifp->if_index);
813
814 /* Initialise pseudo media types. */
815 ifmedia_init(&sca->media, 0, epair_media_change, epair_media_status);
816 ifmedia_add(&sca->media, IFM_ETHER | IFM_10G_T, 0, NULL);
817 ifmedia_set(&sca->media, IFM_ETHER | IFM_10G_T);
818 ifmedia_init(&scb->media, 0, epair_media_change, epair_media_status);
819 ifmedia_add(&scb->media, IFM_ETHER | IFM_10G_T, 0, NULL);
820 ifmedia_set(&scb->media, IFM_ETHER | IFM_10G_T);
821
822 /* Finish initialization of interface <n>a. */
823 ifp = sca->ifp;
824 ifp->if_softc = sca;
825 strlcpy(ifp->if_xname, name, IFNAMSIZ);
826 ifp->if_dname = epairname;
827 ifp->if_dunit = unit;
828 ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
829 ifp->if_capabilities = IFCAP_VLAN_MTU;
830 ifp->if_capenable = IFCAP_VLAN_MTU;
831 ifp->if_start = epair_start;
832 ifp->if_ioctl = epair_ioctl;
833 ifp->if_init = epair_init;
834 ifp->if_snd.ifq_maxlen = ifqmaxlen;
835 /* Assign a hopefully unique, locally administered etheraddr. */
836 eaddr[0] = 0x02;
837 eaddr[3] = (ifp->if_index >> 8) & 0xff;
838 eaddr[4] = ifp->if_index & 0xff;
839 eaddr[5] = 0x0a;
840 ether_ifattach(ifp, eaddr);
841 sca->if_qflush = ifp->if_qflush;
842 ifp->if_qflush = epair_qflush;
843 ifp->if_transmit = epair_transmit;
844 ifp->if_baudrate = IF_Gbps(10); /* arbitrary maximum */
845
846 /* Swap the name and finish initialization of interface <n>b. */
847 *dp = 'b';
848
849 ifp = scb->ifp;
850 ifp->if_softc = scb;
851 strlcpy(ifp->if_xname, name, IFNAMSIZ);
852 ifp->if_dname = epairname;
853 ifp->if_dunit = unit;
854 ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
855 ifp->if_capabilities = IFCAP_VLAN_MTU;
856 ifp->if_capenable = IFCAP_VLAN_MTU;
857 ifp->if_start = epair_start;
858 ifp->if_ioctl = epair_ioctl;
859 ifp->if_init = epair_init;
860 ifp->if_snd.ifq_maxlen = ifqmaxlen;
861 /* We need to play some tricks here for the second interface. */
862 strlcpy(name, epairname, len);
863 error = if_clone_create(name, len, (caddr_t)scb);
864 if (error)
865 panic("%s: if_clone_create() for our 2nd iface failed: %d",
866 __func__, error);
867 scb->if_qflush = ifp->if_qflush;
868 ifp->if_qflush = epair_qflush;
869 ifp->if_transmit = epair_transmit;
870 ifp->if_baudrate = IF_Gbps(10); /* arbitrary maximum */
871
872 /*
873 * Restore name to <n>a as the ifp for this will go into the
874 * cloner list for the initial call.
875 */
876 strlcpy(name, sca->ifp->if_xname, len);
877 DPRINTF("name='%s/%db' created sca=%p scb=%p\n", name, unit, sca, scb);
878
879 /* Tell the world, that we are ready to rock. */
880 sca->ifp->if_drv_flags |= IFF_DRV_RUNNING;
881 scb->ifp->if_drv_flags |= IFF_DRV_RUNNING;
882 if_link_state_change(sca->ifp, LINK_STATE_UP);
883 if_link_state_change(scb->ifp, LINK_STATE_UP);
884
885 return (0);
886 }
887
888 static int
889 epair_clone_destroy(struct if_clone *ifc, struct ifnet *ifp)
890 {
891 struct ifnet *oifp;
892 struct epair_softc *sca, *scb;
893 int unit, error;
894
895 DPRINTF("ifp=%p\n", ifp);
896
897 /*
898 * In case we called into if_clone_destroyif() ourselves
899 * again to remove the second interface, the softc will be
900 * NULL. In that case so not do anything but return success.
901 */
902 if (ifp->if_softc == NULL)
903 return (0);
904
905 unit = ifp->if_dunit;
906 sca = ifp->if_softc;
907 oifp = sca->oifp;
908 scb = oifp->if_softc;
909
910 DPRINTF("ifp=%p oifp=%p\n", ifp, oifp);
911 if_link_state_change(ifp, LINK_STATE_DOWN);
912 if_link_state_change(oifp, LINK_STATE_DOWN);
913 ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
914 oifp->if_drv_flags &= ~IFF_DRV_RUNNING;
915
916 /*
917 * Get rid of our second half. As the other of the two
918 * interfaces may reside in a different vnet, we need to
919 * switch before freeing them.
920 */
921 CURVNET_SET_QUIET(oifp->if_vnet);
922 ether_ifdetach(oifp);
923 /*
924 * Wait for all packets to be dispatched to if_input.
925 * The numbers can only go down as the interface is
926 * detached so there is no need to use atomics.
927 */
928 DPRINTF("scb refcnt=%u\n", scb->refcount);
929 EPAIR_REFCOUNT_ASSERT(scb->refcount == 1,
930 ("%s: ifp=%p scb->refcount!=1: %d", __func__, oifp, scb->refcount));
931 oifp->if_softc = NULL;
932 error = if_clone_destroyif(ifc, oifp);
933 if (error)
934 panic("%s: if_clone_destroyif() for our 2nd iface failed: %d",
935 __func__, error);
936 if_free(oifp);
937 ifmedia_removeall(&scb->media);
938 free(scb, M_EPAIR);
939 CURVNET_RESTORE();
940
941 ether_ifdetach(ifp);
942 /*
943 * Wait for all packets to be dispatched to if_input.
944 */
945 DPRINTF("sca refcnt=%u\n", sca->refcount);
946 EPAIR_REFCOUNT_ASSERT(sca->refcount == 1,
947 ("%s: ifp=%p sca->refcount!=1: %d", __func__, ifp, sca->refcount));
948 if_free(ifp);
949 ifmedia_removeall(&sca->media);
950 free(sca, M_EPAIR);
951 ifc_free_unit(ifc, unit);
952
953 return (0);
954 }
955
956 static void
957 vnet_epair_init(const void *unused __unused)
958 {
959
960 V_epair_cloner = if_clone_advanced(epairname, 0,
961 epair_clone_match, epair_clone_create, epair_clone_destroy);
962 #ifdef VIMAGE
963 netisr_register_vnet(&epair_nh);
964 #endif
965 }
966 VNET_SYSINIT(vnet_epair_init, SI_SUB_PSEUDO, SI_ORDER_ANY,
967 vnet_epair_init, NULL);
968
969 static void
970 vnet_epair_uninit(const void *unused __unused)
971 {
972
973 #ifdef VIMAGE
974 netisr_unregister_vnet(&epair_nh);
975 #endif
976 if_clone_detach(V_epair_cloner);
977 }
978 VNET_SYSUNINIT(vnet_epair_uninit, SI_SUB_INIT_IF, SI_ORDER_ANY,
979 vnet_epair_uninit, NULL);
980
981 static int
982 epair_modevent(module_t mod, int type, void *data)
983 {
984 int qlimit;
985
986 switch (type) {
987 case MOD_LOAD:
988 /* For now limit us to one global mutex and one inq. */
989 epair_dpcpu_init();
990 epair_nh.nh_qlimit = 42 * ifqmaxlen; /* 42 shall be the number. */
991 if (TUNABLE_INT_FETCH("net.link.epair.netisr_maxqlen", &qlimit))
992 epair_nh.nh_qlimit = qlimit;
993 netisr_register(&epair_nh);
994 if (bootverbose)
995 printf("%s initialized.\n", epairname);
996 break;
997 case MOD_UNLOAD:
998 netisr_unregister(&epair_nh);
999 epair_dpcpu_detach();
1000 if (bootverbose)
1001 printf("%s unloaded.\n", epairname);
1002 break;
1003 default:
1004 return (EOPNOTSUPP);
1005 }
1006 return (0);
1007 }
1008
1009 static moduledata_t epair_mod = {
1010 "if_epair",
1011 epair_modevent,
1012 0
1013 };
1014
1015 DECLARE_MODULE(if_epair, epair_mod, SI_SUB_PSEUDO, SI_ORDER_MIDDLE);
1016 MODULE_VERSION(if_epair, 1);
Cache object: 2ecf86a09a3a5137a7ceefecf4153848
|