1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2008 The FreeBSD Foundation
5 * Copyright (c) 2009-2021 Bjoern A. Zeeb <bz@FreeBSD.org>
6 *
7 * This software was developed by CK Software GmbH under sponsorship
8 * from the FreeBSD Foundation.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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 * A pair of virtual back-to-back connected ethernet like interfaces
34 * (``two interfaces with a virtual cross-over cable'').
35 *
36 * This is mostly intended to be used to provide connectivity between
37 * different virtual network stack instances.
38 */
39
40 #include <sys/cdefs.h>
41 #include "opt_rss.h"
42 #include "opt_inet.h"
43 #include "opt_inet6.h"
44
45 #include <sys/param.h>
46 #include <sys/bus.h>
47 #include <sys/hash.h>
48 #include <sys/interrupt.h>
49 #include <sys/jail.h>
50 #include <sys/kernel.h>
51 #include <sys/libkern.h>
52 #include <sys/malloc.h>
53 #include <sys/mbuf.h>
54 #include <sys/module.h>
55 #include <sys/proc.h>
56 #include <sys/queue.h>
57 #include <sys/sched.h>
58 #include <sys/smp.h>
59 #include <sys/socket.h>
60 #include <sys/sockio.h>
61 #include <sys/sysctl.h>
62 #include <sys/taskqueue.h>
63
64 #include <net/bpf.h>
65 #include <net/ethernet.h>
66 #include <net/if.h>
67 #include <net/if_var.h>
68 #include <net/if_clone.h>
69 #include <net/if_media.h>
70 #include <net/if_private.h>
71 #include <net/if_types.h>
72 #include <net/if_vlan_var.h>
73 #include <net/netisr.h>
74 #ifdef RSS
75 #include <net/rss_config.h>
76 #ifdef INET
77 #include <netinet/in_rss.h>
78 #endif
79 #ifdef INET6
80 #include <netinet6/in6_rss.h>
81 #endif
82 #endif
83 #include <net/vnet.h>
84
85 static const char epairname[] = "epair";
86 #define RXRSIZE 4096 /* Probably overkill by 4-8x. */
87
88 static MALLOC_DEFINE(M_EPAIR, epairname,
89 "Pair of virtual cross-over connected Ethernet-like interfaces");
90
91 VNET_DEFINE_STATIC(struct if_clone *, epair_cloner);
92 #define V_epair_cloner VNET(epair_cloner)
93
94 static unsigned int next_index = 0;
95 #define EPAIR_LOCK_INIT() mtx_init(&epair_n_index_mtx, "epairidx", \
96 NULL, MTX_DEF)
97 #define EPAIR_LOCK_DESTROY() mtx_destroy(&epair_n_index_mtx)
98 #define EPAIR_LOCK() mtx_lock(&epair_n_index_mtx)
99 #define EPAIR_UNLOCK() mtx_unlock(&epair_n_index_mtx)
100
101 SYSCTL_DECL(_net_link);
102 static SYSCTL_NODE(_net_link, OID_AUTO, epair, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
103 "Pair of virtual cross-over connected Ethernet-like interfaces");
104
105 static bool use_ether_gen_addr = true;
106 SYSCTL_BOOL(_net_link_epair, OID_AUTO, ether_gen_addr, CTLFLAG_RWTUN,
107 &use_ether_gen_addr, false,
108 "Generate MAC with FreeBSD OUI using ether_gen_addr(9)");
109
110 struct epair_softc;
111 struct epair_queue {
112 struct mtx mtx;
113 struct mbufq q;
114 int id;
115 enum {
116 EPAIR_QUEUE_IDLE,
117 EPAIR_QUEUE_WAKING,
118 EPAIR_QUEUE_RUNNING,
119 } state;
120 struct task tx_task;
121 struct epair_softc *sc;
122 };
123
124 static struct mtx epair_n_index_mtx;
125 struct epair_softc {
126 struct ifnet *ifp; /* This ifp. */
127 struct ifnet *oifp; /* other ifp of pair. */
128 int num_queues;
129 struct epair_queue *queues;
130 struct ifmedia media; /* Media config (fake). */
131 STAILQ_ENTRY(epair_softc) entry;
132 };
133
134 struct epair_tasks_t {
135 int tasks;
136 struct taskqueue *tq[MAXCPU];
137 };
138
139 static struct epair_tasks_t epair_tasks;
140
141 static void
epair_clear_mbuf(struct mbuf * m)142 epair_clear_mbuf(struct mbuf *m)
143 {
144 M_ASSERTPKTHDR(m);
145
146 /* Remove any CSUM_SND_TAG as ether_input will barf. */
147 if (m->m_pkthdr.csum_flags & CSUM_SND_TAG) {
148 m_snd_tag_rele(m->m_pkthdr.snd_tag);
149 m->m_pkthdr.snd_tag = NULL;
150 m->m_pkthdr.csum_flags &= ~CSUM_SND_TAG;
151 }
152
153 m_tag_delete_nonpersistent(m);
154 }
155
156 static void
epair_tx_start_deferred(void * arg,int pending)157 epair_tx_start_deferred(void *arg, int pending)
158 {
159 struct epair_queue *q = (struct epair_queue *)arg;
160 if_t ifp;
161 struct mbuf *m, *n;
162 bool resched;
163
164 ifp = q->sc->ifp;
165
166 if_ref(ifp);
167 CURVNET_SET(ifp->if_vnet);
168
169 mtx_lock(&q->mtx);
170 m = mbufq_flush(&q->q);
171 q->state = EPAIR_QUEUE_RUNNING;
172 mtx_unlock(&q->mtx);
173
174 while (m != NULL) {
175 n = STAILQ_NEXT(m, m_stailqpkt);
176 m->m_nextpkt = NULL;
177 if_input(ifp, m);
178 m = n;
179 }
180
181 /*
182 * Avoid flushing the queue more than once per task. We can otherwise
183 * end up starving ourselves in a multi-epair routing configuration.
184 */
185 mtx_lock(&q->mtx);
186 if (!mbufq_empty(&q->q)) {
187 resched = true;
188 q->state = EPAIR_QUEUE_WAKING;
189 } else {
190 resched = false;
191 q->state = EPAIR_QUEUE_IDLE;
192 }
193 mtx_unlock(&q->mtx);
194
195 if (resched)
196 taskqueue_enqueue(epair_tasks.tq[q->id], &q->tx_task);
197
198 CURVNET_RESTORE();
199 if_rele(ifp);
200 }
201
202 static struct epair_queue *
epair_select_queue(struct epair_softc * sc,struct mbuf * m)203 epair_select_queue(struct epair_softc *sc, struct mbuf *m)
204 {
205 uint32_t bucket;
206 #ifdef RSS
207 struct ether_header *eh;
208 int ret;
209
210 ret = rss_m2bucket(m, &bucket);
211 if (ret) {
212 /* Actually hash the packet. */
213 eh = mtod(m, struct ether_header *);
214
215 switch (ntohs(eh->ether_type)) {
216 #ifdef INET
217 case ETHERTYPE_IP:
218 rss_soft_m2cpuid_v4(m, 0, &bucket);
219 break;
220 #endif
221 #ifdef INET6
222 case ETHERTYPE_IPV6:
223 rss_soft_m2cpuid_v6(m, 0, &bucket);
224 break;
225 #endif
226 default:
227 bucket = 0;
228 break;
229 }
230 }
231 bucket %= sc->num_queues;
232 #else
233 bucket = 0;
234 #endif
235 return (&sc->queues[bucket]);
236 }
237
238 static void
epair_prepare_mbuf(struct mbuf * m,struct ifnet * src_ifp)239 epair_prepare_mbuf(struct mbuf *m, struct ifnet *src_ifp)
240 {
241 M_ASSERTPKTHDR(m);
242 epair_clear_mbuf(m);
243 if_setrcvif(m, src_ifp);
244 M_SETFIB(m, src_ifp->if_fib);
245
246 MPASS(m->m_nextpkt == NULL);
247 MPASS((m->m_pkthdr.csum_flags & CSUM_SND_TAG) == 0);
248 }
249
250 static void
epair_menq(struct mbuf * m,struct epair_softc * osc)251 epair_menq(struct mbuf *m, struct epair_softc *osc)
252 {
253 struct epair_queue *q;
254 struct ifnet *ifp, *oifp;
255 int error, len;
256 bool mcast;
257
258 /*
259 * I know this looks weird. We pass the "other sc" as we need that one
260 * and can get both ifps from it as well.
261 */
262 oifp = osc->ifp;
263 ifp = osc->oifp;
264
265 epair_prepare_mbuf(m, oifp);
266
267 /* Save values as once the mbuf is queued, it's not ours anymore. */
268 len = m->m_pkthdr.len;
269 mcast = (m->m_flags & (M_BCAST | M_MCAST)) != 0;
270
271 q = epair_select_queue(osc, m);
272
273 mtx_lock(&q->mtx);
274 if (q->state == EPAIR_QUEUE_IDLE) {
275 q->state = EPAIR_QUEUE_WAKING;
276 taskqueue_enqueue(epair_tasks.tq[q->id], &q->tx_task);
277 }
278 error = mbufq_enqueue(&q->q, m);
279 mtx_unlock(&q->mtx);
280
281 if (error != 0) {
282 m_freem(m);
283 if_inc_counter(ifp, IFCOUNTER_OQDROPS, 1);
284 } else {
285 if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);
286 if_inc_counter(ifp, IFCOUNTER_OBYTES, len);
287 if (mcast)
288 if_inc_counter(ifp, IFCOUNTER_OMCASTS, 1);
289 if_inc_counter(oifp, IFCOUNTER_IPACKETS, 1);
290 }
291 }
292
293 static void
epair_start(struct ifnet * ifp)294 epair_start(struct ifnet *ifp)
295 {
296 struct mbuf *m;
297 struct epair_softc *sc;
298 struct ifnet *oifp;
299
300 /*
301 * We get packets here from ether_output via if_handoff()
302 * and need to put them into the input queue of the oifp
303 * and will put the packet into the receive-queue (rxq) of the
304 * other interface (oifp) of our pair.
305 */
306 sc = ifp->if_softc;
307 oifp = sc->oifp;
308 sc = oifp->if_softc;
309 for (;;) {
310 IFQ_DEQUEUE(&ifp->if_snd, m);
311 if (m == NULL)
312 break;
313 M_ASSERTPKTHDR(m);
314 BPF_MTAP(ifp, m);
315
316 /* In case either interface is not usable drop the packet. */
317 if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0 ||
318 (ifp->if_flags & IFF_UP) == 0 ||
319 (oifp->if_drv_flags & IFF_DRV_RUNNING) == 0 ||
320 (oifp->if_flags & IFF_UP) == 0) {
321 m_freem(m);
322 continue;
323 }
324
325 epair_menq(m, sc);
326 }
327 }
328
329 static int
epair_transmit(struct ifnet * ifp,struct mbuf * m)330 epair_transmit(struct ifnet *ifp, struct mbuf *m)
331 {
332 struct epair_softc *sc;
333 struct ifnet *oifp;
334 #ifdef ALTQ
335 int len;
336 bool mcast;
337 #endif
338
339 if (m == NULL)
340 return (0);
341 M_ASSERTPKTHDR(m);
342
343 /*
344 * We could just transmit this, but it makes testing easier if we're a
345 * little bit more like real hardware.
346 * Allow just that little bit extra for ethernet (and vlan) headers.
347 */
348 if (m->m_pkthdr.len > (ifp->if_mtu + sizeof(struct ether_vlan_header))) {
349 m_freem(m);
350 if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
351 return (E2BIG);
352 }
353
354 /*
355 * We are not going to use the interface en/dequeue mechanism
356 * on the TX side. We are called from ether_output_frame()
357 * and will put the packet into the receive-queue (rxq) of the
358 * other interface (oifp) of our pair.
359 */
360 if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) {
361 m_freem(m);
362 if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
363 return (ENXIO);
364 }
365 if ((ifp->if_flags & IFF_UP) == 0) {
366 m_freem(m);
367 if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
368 return (ENETDOWN);
369 }
370
371 BPF_MTAP(ifp, m);
372
373 /*
374 * In case the outgoing interface is not usable,
375 * drop the packet.
376 */
377 sc = ifp->if_softc;
378 oifp = sc->oifp;
379 if ((oifp->if_drv_flags & IFF_DRV_RUNNING) == 0 ||
380 (oifp->if_flags & IFF_UP) == 0) {
381 if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
382 m_freem(m);
383 return (0);
384 }
385
386 #ifdef ALTQ
387 len = m->m_pkthdr.len;
388 mcast = (m->m_flags & (M_BCAST | M_MCAST)) != 0;
389 int error = 0;
390
391 /* Support ALTQ via the classic if_start() path. */
392 IF_LOCK(&ifp->if_snd);
393 if (ALTQ_IS_ENABLED(&ifp->if_snd)) {
394 ALTQ_ENQUEUE(&ifp->if_snd, m, NULL, error);
395 if (error)
396 if_inc_counter(ifp, IFCOUNTER_OQDROPS, 1);
397 IF_UNLOCK(&ifp->if_snd);
398 if (!error) {
399 if_inc_counter(ifp, IFCOUNTER_OBYTES, len);
400 if (mcast)
401 if_inc_counter(ifp, IFCOUNTER_OMCASTS, 1);
402 epair_start(ifp);
403 }
404 return (error);
405 }
406 IF_UNLOCK(&ifp->if_snd);
407 #endif
408
409 epair_menq(m, oifp->if_softc);
410 return (0);
411 }
412
413 static void
epair_qflush(struct ifnet * ifp __unused)414 epair_qflush(struct ifnet *ifp __unused)
415 {
416 }
417
418 static int
epair_media_change(struct ifnet * ifp __unused)419 epair_media_change(struct ifnet *ifp __unused)
420 {
421
422 /* Do nothing. */
423 return (0);
424 }
425
426 static void
epair_media_status(struct ifnet * ifp __unused,struct ifmediareq * imr)427 epair_media_status(struct ifnet *ifp __unused, struct ifmediareq *imr)
428 {
429
430 imr->ifm_status = IFM_AVALID | IFM_ACTIVE;
431 imr->ifm_active = IFM_ETHER | IFM_10G_T | IFM_FDX;
432 }
433
434 /*
435 * Update ifp->if_hwassist according to the current value of ifp->if_capenable.
436 */
437 static void
epair_caps_changed(struct ifnet * ifp)438 epair_caps_changed(struct ifnet *ifp)
439 {
440 uint64_t hwassist = 0;
441
442 if (ifp->if_capenable & IFCAP_TXCSUM)
443 hwassist |= CSUM_IP_TCP | CSUM_IP_UDP;
444 if (ifp->if_capenable & IFCAP_TXCSUM_IPV6)
445 hwassist |= CSUM_IP6_TCP | CSUM_IP6_UDP;
446 ifp->if_hwassist = hwassist;
447 }
448
449 static int
epair_ioctl(struct ifnet * ifp,u_long cmd,caddr_t data)450 epair_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
451 {
452 struct epair_softc *sc;
453 struct ifreq *ifr;
454 int error;
455
456 ifr = (struct ifreq *)data;
457 switch (cmd) {
458 case SIOCSIFFLAGS:
459 case SIOCADDMULTI:
460 case SIOCDELMULTI:
461 error = 0;
462 break;
463
464 case SIOCSIFMEDIA:
465 case SIOCGIFMEDIA:
466 sc = ifp->if_softc;
467 error = ifmedia_ioctl(ifp, ifr, &sc->media, cmd);
468 break;
469
470 case SIOCSIFMTU:
471 /* We basically allow all kinds of MTUs. */
472 ifp->if_mtu = ifr->ifr_mtu;
473 error = 0;
474 break;
475
476 case SIOCGIFCAP:
477 ifr->ifr_reqcap = ifp->if_capabilities;
478 ifr->ifr_curcap = ifp->if_capenable;
479 error = 0;
480 break;
481 case SIOCSIFCAP:
482 /*
483 * Enable/disable capabilities as requested, besides
484 * IFCAP_RXCSUM(_IPV6), which always remain enabled.
485 * Incoming packets may have the mbuf flag CSUM_DATA_VALID set.
486 * Without IFCAP_RXCSUM(_IPV6), this flag would have to be
487 * removed, which does not seem helpful.
488 */
489 ifp->if_capenable = ifr->ifr_reqcap | IFCAP_RXCSUM |
490 IFCAP_RXCSUM_IPV6;
491 epair_caps_changed(ifp);
492 VLAN_CAPABILITIES(ifp);
493 /*
494 * If IFCAP_TXCSUM(_IPV6) has been changed, change it on the
495 * other epair interface as well.
496 * A bridge disables IFCAP_TXCSUM(_IPV6) when adding one epair
497 * interface if another interface in the bridge has it disabled.
498 * In that case this capability needs to be disabled on the
499 * other epair interface to avoid sending packets in the bridge
500 * that rely on this capability.
501 * Do the same for IFCAP_VLAN_HWTAGGING. If the sending epair
502 * end has this capability enabled, the other end has to have
503 * it enabled too. Otherwise, epair would have to add the VLAN
504 * tag in the Ethernet header.
505 */
506 sc = ifp->if_softc;
507 if ((ifp->if_capenable ^ sc->oifp->if_capenable) &
508 (IFCAP_TXCSUM | IFCAP_TXCSUM_IPV6 | IFCAP_VLAN_HWTAGGING)) {
509 sc->oifp->if_capenable &=
510 ~(IFCAP_TXCSUM | IFCAP_TXCSUM_IPV6 |
511 IFCAP_VLAN_HWTAGGING);
512 sc->oifp->if_capenable |= ifp->if_capenable &
513 (IFCAP_TXCSUM | IFCAP_TXCSUM_IPV6 |
514 IFCAP_VLAN_HWTAGGING);
515 epair_caps_changed(sc->oifp);
516 VLAN_CAPABILITIES(sc->oifp);
517 }
518 error = 0;
519 break;
520
521 default:
522 /* Let the common ethernet handler process this. */
523 error = ether_ioctl(ifp, cmd, data);
524 break;
525 }
526
527 return (error);
528 }
529
530 static void
epair_init(void * dummy __unused)531 epair_init(void *dummy __unused)
532 {
533 }
534
535 /*
536 * Interface cloning functions.
537 * We use our private ones so that we can create/destroy our secondary
538 * device along with the primary one.
539 */
540 static int
epair_clone_match(struct if_clone * ifc,const char * name)541 epair_clone_match(struct if_clone *ifc, const char *name)
542 {
543 const char *cp;
544
545 /*
546 * Our base name is epair.
547 * Our interfaces will be named epair<n>[ab].
548 * So accept anything of the following list:
549 * - epair
550 * - epair<n>
551 * but not the epair<n>[ab] versions.
552 */
553 if (strncmp(epairname, name, sizeof(epairname)-1) != 0)
554 return (0);
555
556 for (cp = name + sizeof(epairname) - 1; *cp != '\0'; cp++) {
557 if (*cp < '0' || *cp > '9')
558 return (0);
559 }
560
561 return (1);
562 }
563
564 static void
epair_generate_mac_byname(struct epair_softc * sc,uint8_t eaddr[])565 epair_generate_mac_byname(struct epair_softc *sc, uint8_t eaddr[])
566 {
567 struct ether_addr gen_eaddr;
568 int i;
569
570 ether_gen_addr_byname(if_name(sc->ifp), &gen_eaddr);
571 for (i = 0; i < ETHER_ADDR_LEN; i++)
572 eaddr[i] = gen_eaddr.octet[i];
573 }
574
575 static void
epair_clone_add(struct if_clone * ifc,struct epair_softc * scb)576 epair_clone_add(struct if_clone *ifc, struct epair_softc *scb)
577 {
578 struct ifnet *ifp;
579 uint8_t eaddr[ETHER_ADDR_LEN]; /* 00:00:00:00:00:00 */
580
581 ifp = scb->ifp;
582 if (!use_ether_gen_addr) {
583 /* Copy epairNa etheraddr and change the last byte. */
584 memcpy(eaddr, scb->oifp->if_hw_addr, ETHER_ADDR_LEN);
585 eaddr[5] = 0x0b;
586 } else
587 epair_generate_mac_byname(scb, eaddr);
588 ether_ifattach(ifp, eaddr);
589
590 if_clone_addif(ifc, ifp);
591 }
592
593 static struct epair_softc *
epair_alloc_sc(struct if_clone * ifc)594 epair_alloc_sc(struct if_clone *ifc)
595 {
596 struct epair_softc *sc;
597
598 struct ifnet *ifp = if_alloc(IFT_ETHER);
599 sc = malloc(sizeof(struct epair_softc), M_EPAIR, M_WAITOK | M_ZERO);
600 sc->ifp = ifp;
601 sc->num_queues = epair_tasks.tasks;
602 sc->queues = mallocarray(sc->num_queues, sizeof(struct epair_queue),
603 M_EPAIR, M_WAITOK);
604 for (int i = 0; i < sc->num_queues; i++) {
605 struct epair_queue *q = &sc->queues[i];
606 q->id = i;
607 q->state = EPAIR_QUEUE_IDLE;
608 mtx_init(&q->mtx, "epairq", NULL, MTX_DEF | MTX_NEW);
609 mbufq_init(&q->q, RXRSIZE);
610 q->sc = sc;
611 NET_TASK_INIT(&q->tx_task, 0, epair_tx_start_deferred, q);
612 }
613
614 /* Initialise pseudo media types. */
615 ifmedia_init(&sc->media, 0, epair_media_change, epair_media_status);
616 ifmedia_add(&sc->media, IFM_ETHER | IFM_10G_T, 0, NULL);
617 ifmedia_set(&sc->media, IFM_ETHER | IFM_10G_T);
618
619 return (sc);
620 }
621
622 static void
epair_setup_ifp(struct epair_softc * sc,char * name,int unit)623 epair_setup_ifp(struct epair_softc *sc, char *name, int unit)
624 {
625 struct ifnet *ifp = sc->ifp;
626
627 ifp->if_softc = sc;
628 strlcpy(ifp->if_xname, name, IFNAMSIZ);
629 ifp->if_dname = epairname;
630 ifp->if_dunit = unit;
631 ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
632 ifp->if_capabilities =
633 IFCAP_VLAN_MTU | IFCAP_VLAN_HWTAGGING |
634 IFCAP_TXCSUM | IFCAP_RXCSUM |
635 IFCAP_TXCSUM_IPV6 | IFCAP_RXCSUM_IPV6;
636 ifp->if_capenable = ifp->if_capabilities;
637 epair_caps_changed(ifp);
638 ifp->if_transmit = epair_transmit;
639 ifp->if_qflush = epair_qflush;
640 ifp->if_start = epair_start;
641 ifp->if_ioctl = epair_ioctl;
642 ifp->if_init = epair_init;
643 if_setsendqlen(ifp, ifqmaxlen);
644 if_setsendqready(ifp);
645
646 ifp->if_baudrate = IF_Gbps(10); /* arbitrary maximum */
647 }
648
649 static void
epair_generate_mac(struct epair_softc * sc,uint8_t * eaddr)650 epair_generate_mac(struct epair_softc *sc, uint8_t *eaddr)
651 {
652 uint32_t key[3];
653 uint32_t hash;
654 uint64_t hostid;
655
656 EPAIR_LOCK();
657 #ifdef SMP
658 /* Get an approximate distribution. */
659 hash = next_index % mp_ncpus;
660 #else
661 hash = 0;
662 #endif
663 EPAIR_UNLOCK();
664
665 /*
666 * Calculate the etheraddr hashing the hostid and the
667 * interface index. The result would be hopefully unique.
668 * Note that the "a" component of an epair instance may get moved
669 * to a different VNET after creation. In that case its index
670 * will be freed and the index can get reused by new epair instance.
671 * Make sure we do not create same etheraddr again.
672 */
673 getcredhostid(curthread->td_ucred, (unsigned long *)&hostid);
674 if (hostid == 0)
675 arc4rand(&hostid, sizeof(hostid), 0);
676
677 struct ifnet *ifp = sc->ifp;
678 EPAIR_LOCK();
679 if (ifp->if_index > next_index)
680 next_index = ifp->if_index;
681 else
682 next_index++;
683
684 key[0] = (uint32_t)next_index;
685 EPAIR_UNLOCK();
686 key[1] = (uint32_t)(hostid & 0xffffffff);
687 key[2] = (uint32_t)((hostid >> 32) & 0xfffffffff);
688 hash = jenkins_hash32(key, 3, 0);
689
690 eaddr[0] = 0x02;
691 memcpy(&eaddr[1], &hash, 4);
692 eaddr[5] = 0x0a;
693 }
694
695 static void
epair_free_sc(struct epair_softc * sc)696 epair_free_sc(struct epair_softc *sc)
697 {
698
699 if_free(sc->ifp);
700 ifmedia_removeall(&sc->media);
701 for (int i = 0; i < sc->num_queues; i++) {
702 struct epair_queue *q = &sc->queues[i];
703 mtx_destroy(&q->mtx);
704 }
705 free(sc->queues, M_EPAIR);
706 free(sc, M_EPAIR);
707 }
708
709 static void
epair_set_state(struct ifnet * ifp,bool running)710 epair_set_state(struct ifnet *ifp, bool running)
711 {
712 if (running) {
713 ifp->if_drv_flags |= IFF_DRV_RUNNING;
714 if_link_state_change(ifp, LINK_STATE_UP);
715 } else {
716 if_link_state_change(ifp, LINK_STATE_DOWN);
717 ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
718 }
719 }
720
721 static int
epair_handle_unit(struct if_clone * ifc,char * name,size_t len,int * punit)722 epair_handle_unit(struct if_clone *ifc, char *name, size_t len, int *punit)
723 {
724 int error = 0, unit, wildcard;
725 char *dp;
726
727 /* Try to see if a special unit was requested. */
728 error = ifc_name2unit(name, &unit);
729 if (error != 0)
730 return (error);
731 wildcard = (unit < 0);
732
733 error = ifc_alloc_unit(ifc, &unit);
734 if (error != 0)
735 return (error);
736
737 /*
738 * If no unit had been given, we need to adjust the ifName.
739 * Also make sure there is space for our extra [ab] suffix.
740 */
741 for (dp = name; *dp != '\0'; dp++);
742 if (wildcard) {
743 int slen = snprintf(dp, len - (dp - name), "%d", unit);
744 if (slen > len - (dp - name) - 1) {
745 /* ifName too long. */
746 error = ENOSPC;
747 goto done;
748 }
749 dp += slen;
750 }
751 if (len - (dp - name) - 1 < 1) {
752 /* No space left for our [ab] suffix. */
753 error = ENOSPC;
754 goto done;
755 }
756 *dp = 'b';
757 /* Must not change dp so we can replace 'a' by 'b' later. */
758 *(dp+1) = '\0';
759
760 /* Check if 'a' and 'b' interfaces already exist. */
761 if (ifunit(name) != NULL) {
762 error = EEXIST;
763 goto done;
764 }
765
766 *dp = 'a';
767 if (ifunit(name) != NULL) {
768 error = EEXIST;
769 goto done;
770 }
771 *punit = unit;
772 done:
773 if (error != 0)
774 ifc_free_unit(ifc, unit);
775
776 return (error);
777 }
778
779 static int
epair_clone_create(struct if_clone * ifc,char * name,size_t len,struct ifc_data * ifd,struct ifnet ** ifpp)780 epair_clone_create(struct if_clone *ifc, char *name, size_t len,
781 struct ifc_data *ifd, struct ifnet **ifpp)
782 {
783 struct epair_softc *sca, *scb;
784 struct ifnet *ifp;
785 char *dp;
786 int error, unit;
787 uint8_t eaddr[ETHER_ADDR_LEN]; /* 00:00:00:00:00:00 */
788
789 error = epair_handle_unit(ifc, name, len, &unit);
790 if (error != 0)
791 return (error);
792
793 /* Allocate memory for both [ab] interfaces */
794 sca = epair_alloc_sc(ifc);
795 scb = epair_alloc_sc(ifc);
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 /* Finish initialization of interface <n>a. */
804 ifp = sca->ifp;
805 epair_setup_ifp(sca, name, unit);
806 if (!use_ether_gen_addr)
807 epair_generate_mac(sca, eaddr);
808 else
809 epair_generate_mac_byname(sca, eaddr);
810
811 ether_ifattach(ifp, eaddr);
812
813 /* Swap the name and finish initialization of interface <n>b. */
814 dp = name + strlen(name) - 1;
815 *dp = 'b';
816
817 epair_setup_ifp(scb, name, unit);
818
819 ifp = scb->ifp;
820 /* We need to play some tricks here for the second interface. */
821 strlcpy(name, epairname, len);
822 /* Correctly set the name for the cloner list. */
823 strlcpy(name, scb->ifp->if_xname, len);
824
825 epair_clone_add(ifc, scb);
826
827 /*
828 * Restore name to <n>a as the ifp for this will go into the
829 * cloner list for the initial call.
830 */
831 strlcpy(name, sca->ifp->if_xname, len);
832
833 /* Tell the world, that we are ready to rock. */
834 epair_set_state(sca->ifp, true);
835 epair_set_state(scb->ifp, true);
836
837 *ifpp = sca->ifp;
838
839 return (0);
840 }
841
842 static void
epair_drain_rings(struct epair_softc * sc)843 epair_drain_rings(struct epair_softc *sc)
844 {
845 for (int i = 0; i < sc->num_queues; i++) {
846 struct epair_queue *q;
847 struct mbuf *m, *n;
848
849 q = &sc->queues[i];
850 mtx_lock(&q->mtx);
851 m = mbufq_flush(&q->q);
852 mtx_unlock(&q->mtx);
853
854 for (; m != NULL; m = n) {
855 n = m->m_nextpkt;
856 m_freem(m);
857 }
858 }
859 }
860
861 static int
epair_clone_destroy(struct if_clone * ifc,struct ifnet * ifp,uint32_t flags)862 epair_clone_destroy(struct if_clone *ifc, struct ifnet *ifp, uint32_t flags)
863 {
864 struct ifnet *oifp;
865 struct epair_softc *sca, *scb;
866 int unit, error;
867
868 /*
869 * In case we called into if_clone_destroyif() ourselves
870 * again to remove the second interface, the softc will be
871 * NULL. In that case so not do anything but return success.
872 */
873 if (ifp->if_softc == NULL)
874 return (0);
875
876 unit = ifp->if_dunit;
877 sca = ifp->if_softc;
878 oifp = sca->oifp;
879 scb = oifp->if_softc;
880
881 /* Frist get the interfaces down and detached. */
882 epair_set_state(ifp, false);
883 epair_set_state(oifp, false);
884
885 ether_ifdetach(ifp);
886 ether_ifdetach(oifp);
887
888 /* Third free any queued packets and all the resources. */
889 CURVNET_SET_QUIET(oifp->if_vnet);
890 epair_drain_rings(scb);
891 oifp->if_softc = NULL;
892 error = if_clone_destroyif(ifc, oifp);
893 if (error)
894 panic("%s: if_clone_destroyif() for our 2nd iface failed: %d",
895 __func__, error);
896 epair_free_sc(scb);
897 CURVNET_RESTORE();
898
899 epair_drain_rings(sca);
900 epair_free_sc(sca);
901
902 /* Last free the cloner unit. */
903 ifc_free_unit(ifc, unit);
904
905 return (0);
906 }
907
908 static void
vnet_epair_init(const void * unused __unused)909 vnet_epair_init(const void *unused __unused)
910 {
911 struct if_clone_addreq req = {
912 .match_f = epair_clone_match,
913 .create_f = epair_clone_create,
914 .destroy_f = epair_clone_destroy,
915 };
916 V_epair_cloner = ifc_attach_cloner(epairname, &req);
917 }
918 VNET_SYSINIT(vnet_epair_init, SI_SUB_PSEUDO, SI_ORDER_ANY,
919 vnet_epair_init, NULL);
920
921 static void
vnet_epair_uninit(const void * unused __unused)922 vnet_epair_uninit(const void *unused __unused)
923 {
924
925 ifc_detach_cloner(V_epair_cloner);
926 }
927 VNET_SYSUNINIT(vnet_epair_uninit, SI_SUB_INIT_IF, SI_ORDER_ANY,
928 vnet_epair_uninit, NULL);
929
930 static int
epair_mod_init(void)931 epair_mod_init(void)
932 {
933 char name[32];
934 epair_tasks.tasks = 0;
935
936 #ifdef RSS
937 int cpu;
938
939 CPU_FOREACH(cpu) {
940 cpuset_t cpu_mask;
941
942 /* Pin to this CPU so we get appropriate NUMA allocations. */
943 thread_lock(curthread);
944 sched_bind(curthread, cpu);
945 thread_unlock(curthread);
946
947 snprintf(name, sizeof(name), "epair_task_%d", cpu);
948
949 epair_tasks.tq[cpu] = taskqueue_create(name, M_WAITOK,
950 taskqueue_thread_enqueue,
951 &epair_tasks.tq[cpu]);
952 CPU_SETOF(cpu, &cpu_mask);
953 taskqueue_start_threads_cpuset(&epair_tasks.tq[cpu], 1, PI_NET,
954 &cpu_mask, "%s", name);
955
956 epair_tasks.tasks++;
957 }
958 thread_lock(curthread);
959 sched_unbind(curthread);
960 thread_unlock(curthread);
961 #else
962 snprintf(name, sizeof(name), "epair_task");
963
964 epair_tasks.tq[0] = taskqueue_create(name, M_WAITOK,
965 taskqueue_thread_enqueue,
966 &epair_tasks.tq[0]);
967 taskqueue_start_threads(&epair_tasks.tq[0], 1, PI_NET, "%s", name);
968
969 epair_tasks.tasks = 1;
970 #endif
971
972 return (0);
973 }
974
975 static void
epair_mod_cleanup(void)976 epair_mod_cleanup(void)
977 {
978
979 for (int i = 0; i < epair_tasks.tasks; i++) {
980 taskqueue_drain_all(epair_tasks.tq[i]);
981 taskqueue_free(epair_tasks.tq[i]);
982 }
983 }
984
985 static int
epair_modevent(module_t mod,int type,void * data)986 epair_modevent(module_t mod, int type, void *data)
987 {
988 int ret;
989
990 switch (type) {
991 case MOD_LOAD:
992 EPAIR_LOCK_INIT();
993 ret = epair_mod_init();
994 if (ret != 0)
995 return (ret);
996 if (bootverbose)
997 printf("%s: %s initialized.\n", __func__, epairname);
998 break;
999 case MOD_UNLOAD:
1000 epair_mod_cleanup();
1001 EPAIR_LOCK_DESTROY();
1002 if (bootverbose)
1003 printf("%s: %s unloaded.\n", __func__, epairname);
1004 break;
1005 default:
1006 return (EOPNOTSUPP);
1007 }
1008 return (0);
1009 }
1010
1011 static moduledata_t epair_mod = {
1012 "if_epair",
1013 epair_modevent,
1014 0
1015 };
1016
1017 DECLARE_MODULE(if_epair, epair_mod, SI_SUB_PSEUDO, SI_ORDER_MIDDLE);
1018 MODULE_VERSION(if_epair, 3);
1019