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 /* Clear vlan information. */
154 m->m_flags &= ~M_VLANTAG;
155 m->m_pkthdr.ether_vtag = 0;
156
157 m_tag_delete_nonpersistent(m);
158 }
159
160 static void
epair_tx_start_deferred(void * arg,int pending)161 epair_tx_start_deferred(void *arg, int pending)
162 {
163 struct epair_queue *q = (struct epair_queue *)arg;
164 if_t ifp;
165 struct mbuf *m, *n;
166 bool resched;
167
168 ifp = q->sc->ifp;
169
170 if_ref(ifp);
171 CURVNET_SET(ifp->if_vnet);
172
173 mtx_lock(&q->mtx);
174 m = mbufq_flush(&q->q);
175 q->state = EPAIR_QUEUE_RUNNING;
176 mtx_unlock(&q->mtx);
177
178 while (m != NULL) {
179 n = STAILQ_NEXT(m, m_stailqpkt);
180 m->m_nextpkt = NULL;
181 if_input(ifp, m);
182 m = n;
183 }
184
185 /*
186 * Avoid flushing the queue more than once per task. We can otherwise
187 * end up starving ourselves in a multi-epair routing configuration.
188 */
189 mtx_lock(&q->mtx);
190 if (!mbufq_empty(&q->q)) {
191 resched = true;
192 q->state = EPAIR_QUEUE_WAKING;
193 } else {
194 resched = false;
195 q->state = EPAIR_QUEUE_IDLE;
196 }
197 mtx_unlock(&q->mtx);
198
199 if (resched)
200 taskqueue_enqueue(epair_tasks.tq[q->id], &q->tx_task);
201
202 CURVNET_RESTORE();
203 if_rele(ifp);
204 }
205
206 static struct epair_queue *
epair_select_queue(struct epair_softc * sc,struct mbuf * m)207 epair_select_queue(struct epair_softc *sc, struct mbuf *m)
208 {
209 uint32_t bucket;
210 #ifdef RSS
211 struct ether_header *eh;
212 int ret;
213
214 ret = rss_m2bucket(m, &bucket);
215 if (ret) {
216 /* Actually hash the packet. */
217 eh = mtod(m, struct ether_header *);
218
219 switch (ntohs(eh->ether_type)) {
220 #ifdef INET
221 case ETHERTYPE_IP:
222 rss_soft_m2cpuid_v4(m, 0, &bucket);
223 break;
224 #endif
225 #ifdef INET6
226 case ETHERTYPE_IPV6:
227 rss_soft_m2cpuid_v6(m, 0, &bucket);
228 break;
229 #endif
230 default:
231 bucket = 0;
232 break;
233 }
234 }
235 bucket %= sc->num_queues;
236 #else
237 bucket = 0;
238 #endif
239 return (&sc->queues[bucket]);
240 }
241
242 static void
epair_prepare_mbuf(struct mbuf * m,struct ifnet * src_ifp)243 epair_prepare_mbuf(struct mbuf *m, struct ifnet *src_ifp)
244 {
245 M_ASSERTPKTHDR(m);
246 epair_clear_mbuf(m);
247 if_setrcvif(m, src_ifp);
248 M_SETFIB(m, src_ifp->if_fib);
249
250 MPASS(m->m_nextpkt == NULL);
251 MPASS((m->m_pkthdr.csum_flags & CSUM_SND_TAG) == 0);
252 }
253
254 static void
epair_menq(struct mbuf * m,struct epair_softc * osc)255 epair_menq(struct mbuf *m, struct epair_softc *osc)
256 {
257 struct epair_queue *q;
258 struct ifnet *ifp, *oifp;
259 int error, len;
260 bool mcast;
261
262 /*
263 * I know this looks weird. We pass the "other sc" as we need that one
264 * and can get both ifps from it as well.
265 */
266 oifp = osc->ifp;
267 ifp = osc->oifp;
268
269 epair_prepare_mbuf(m, oifp);
270
271 /* Save values as once the mbuf is queued, it's not ours anymore. */
272 len = m->m_pkthdr.len;
273 mcast = (m->m_flags & (M_BCAST | M_MCAST)) != 0;
274
275 q = epair_select_queue(osc, m);
276
277 mtx_lock(&q->mtx);
278 if (q->state == EPAIR_QUEUE_IDLE) {
279 q->state = EPAIR_QUEUE_WAKING;
280 taskqueue_enqueue(epair_tasks.tq[q->id], &q->tx_task);
281 }
282 error = mbufq_enqueue(&q->q, m);
283 mtx_unlock(&q->mtx);
284
285 if (error != 0) {
286 m_freem(m);
287 if_inc_counter(ifp, IFCOUNTER_OQDROPS, 1);
288 } else {
289 if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);
290 if_inc_counter(ifp, IFCOUNTER_OBYTES, len);
291 if (mcast)
292 if_inc_counter(ifp, IFCOUNTER_OMCASTS, 1);
293 if_inc_counter(oifp, IFCOUNTER_IPACKETS, 1);
294 }
295 }
296
297 static void
epair_start(struct ifnet * ifp)298 epair_start(struct ifnet *ifp)
299 {
300 struct mbuf *m;
301 struct epair_softc *sc;
302 struct ifnet *oifp;
303
304 /*
305 * We get packets here from ether_output via if_handoff()
306 * and need to put them into the input queue of the oifp
307 * and will put the packet into the receive-queue (rxq) of the
308 * other interface (oifp) of our pair.
309 */
310 sc = ifp->if_softc;
311 oifp = sc->oifp;
312 sc = oifp->if_softc;
313 for (;;) {
314 IFQ_DEQUEUE(&ifp->if_snd, m);
315 if (m == NULL)
316 break;
317 M_ASSERTPKTHDR(m);
318 BPF_MTAP(ifp, m);
319
320 /* In case either interface is not usable drop the packet. */
321 if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0 ||
322 (ifp->if_flags & IFF_UP) == 0 ||
323 (oifp->if_drv_flags & IFF_DRV_RUNNING) == 0 ||
324 (oifp->if_flags & IFF_UP) == 0) {
325 m_freem(m);
326 continue;
327 }
328
329 epair_menq(m, sc);
330 }
331 }
332
333 static int
epair_transmit(struct ifnet * ifp,struct mbuf * m)334 epair_transmit(struct ifnet *ifp, struct mbuf *m)
335 {
336 struct epair_softc *sc;
337 struct ifnet *oifp;
338 #ifdef ALTQ
339 int len;
340 bool mcast;
341 #endif
342
343 if (m == NULL)
344 return (0);
345 M_ASSERTPKTHDR(m);
346
347 /*
348 * We could just transmit this, but it makes testing easier if we're a
349 * little bit more like real hardware.
350 * Allow just that little bit extra for ethernet (and vlan) headers.
351 */
352 if (m->m_pkthdr.len > (ifp->if_mtu + sizeof(struct ether_vlan_header))) {
353 m_freem(m);
354 if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
355 return (E2BIG);
356 }
357
358 /*
359 * We are not going to use the interface en/dequeue mechanism
360 * on the TX side. We are called from ether_output_frame()
361 * and will put the packet into the receive-queue (rxq) of the
362 * other interface (oifp) of our pair.
363 */
364 if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) {
365 m_freem(m);
366 if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
367 return (ENXIO);
368 }
369 if ((ifp->if_flags & IFF_UP) == 0) {
370 m_freem(m);
371 if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
372 return (ENETDOWN);
373 }
374
375 BPF_MTAP(ifp, m);
376
377 /*
378 * In case the outgoing interface is not usable,
379 * drop the packet.
380 */
381 sc = ifp->if_softc;
382 oifp = sc->oifp;
383 if ((oifp->if_drv_flags & IFF_DRV_RUNNING) == 0 ||
384 (oifp->if_flags & IFF_UP) == 0) {
385 if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
386 m_freem(m);
387 return (0);
388 }
389
390 #ifdef ALTQ
391 len = m->m_pkthdr.len;
392 mcast = (m->m_flags & (M_BCAST | M_MCAST)) != 0;
393 int error = 0;
394
395 /* Support ALTQ via the classic if_start() path. */
396 IF_LOCK(&ifp->if_snd);
397 if (ALTQ_IS_ENABLED(&ifp->if_snd)) {
398 ALTQ_ENQUEUE(&ifp->if_snd, m, NULL, error);
399 if (error)
400 if_inc_counter(ifp, IFCOUNTER_OQDROPS, 1);
401 IF_UNLOCK(&ifp->if_snd);
402 if (!error) {
403 if_inc_counter(ifp, IFCOUNTER_OBYTES, len);
404 if (mcast)
405 if_inc_counter(ifp, IFCOUNTER_OMCASTS, 1);
406 epair_start(ifp);
407 }
408 return (error);
409 }
410 IF_UNLOCK(&ifp->if_snd);
411 #endif
412
413 epair_menq(m, oifp->if_softc);
414 return (0);
415 }
416
417 static void
epair_qflush(struct ifnet * ifp __unused)418 epair_qflush(struct ifnet *ifp __unused)
419 {
420 }
421
422 static int
epair_media_change(struct ifnet * ifp __unused)423 epair_media_change(struct ifnet *ifp __unused)
424 {
425
426 /* Do nothing. */
427 return (0);
428 }
429
430 static void
epair_media_status(struct ifnet * ifp __unused,struct ifmediareq * imr)431 epair_media_status(struct ifnet *ifp __unused, struct ifmediareq *imr)
432 {
433
434 imr->ifm_status = IFM_AVALID | IFM_ACTIVE;
435 imr->ifm_active = IFM_ETHER | IFM_10G_T | IFM_FDX;
436 }
437
438 /*
439 * Update ifp->if_hwassist according to the current value of ifp->if_capenable.
440 */
441 static void
epair_caps_changed(struct ifnet * ifp)442 epair_caps_changed(struct ifnet *ifp)
443 {
444 uint64_t hwassist = 0;
445
446 if (ifp->if_capenable & IFCAP_TXCSUM)
447 hwassist |= CSUM_IP_TCP | CSUM_IP_UDP;
448 if (ifp->if_capenable & IFCAP_TXCSUM_IPV6)
449 hwassist |= CSUM_IP6_TCP | CSUM_IP6_UDP;
450 ifp->if_hwassist = hwassist;
451 }
452
453 static int
epair_ioctl(struct ifnet * ifp,u_long cmd,caddr_t data)454 epair_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
455 {
456 struct epair_softc *sc;
457 struct ifreq *ifr;
458 int error;
459
460 ifr = (struct ifreq *)data;
461 switch (cmd) {
462 case SIOCSIFFLAGS:
463 case SIOCADDMULTI:
464 case SIOCDELMULTI:
465 error = 0;
466 break;
467
468 case SIOCSIFMEDIA:
469 case SIOCGIFMEDIA:
470 sc = ifp->if_softc;
471 error = ifmedia_ioctl(ifp, ifr, &sc->media, cmd);
472 break;
473
474 case SIOCSIFMTU:
475 /* We basically allow all kinds of MTUs. */
476 ifp->if_mtu = ifr->ifr_mtu;
477 error = 0;
478 break;
479
480 case SIOCGIFCAP:
481 ifr->ifr_reqcap = ifp->if_capabilities;
482 ifr->ifr_curcap = ifp->if_capenable;
483 error = 0;
484 break;
485 case SIOCSIFCAP:
486 /*
487 * Enable/disable capabilities as requested, besides
488 * IFCAP_RXCSUM(_IPV6), which always remain enabled.
489 * Incoming packets may have the mbuf flag CSUM_DATA_VALID set.
490 * Without IFCAP_RXCSUM(_IPV6), this flag would have to be
491 * removed, which does not seem helpful.
492 */
493 ifp->if_capenable = ifr->ifr_reqcap | IFCAP_RXCSUM |
494 IFCAP_RXCSUM_IPV6;
495 epair_caps_changed(ifp);
496 /*
497 * If IFCAP_TXCSUM(_IPV6) has been changed, change it on the
498 * other epair interface as well.
499 * A bridge disables IFCAP_TXCSUM(_IPV6) when adding one epair
500 * interface if another interface in the bridge has it disabled.
501 * In that case this capability needs to be disabled on the
502 * other epair interface to avoid sending packets in the bridge
503 * that rely on this capability.
504 */
505 sc = ifp->if_softc;
506 if ((ifp->if_capenable ^ sc->oifp->if_capenable) &
507 (IFCAP_TXCSUM | IFCAP_TXCSUM_IPV6)) {
508 sc->oifp->if_capenable &=
509 ~(IFCAP_TXCSUM | IFCAP_TXCSUM_IPV6);
510 sc->oifp->if_capenable |= ifp->if_capenable &
511 (IFCAP_TXCSUM | IFCAP_TXCSUM_IPV6);
512 epair_caps_changed(sc->oifp);
513 }
514 VLAN_CAPABILITIES(ifp);
515 error = 0;
516 break;
517
518 default:
519 /* Let the common ethernet handler process this. */
520 error = ether_ioctl(ifp, cmd, data);
521 break;
522 }
523
524 return (error);
525 }
526
527 static void
epair_init(void * dummy __unused)528 epair_init(void *dummy __unused)
529 {
530 }
531
532 /*
533 * Interface cloning functions.
534 * We use our private ones so that we can create/destroy our secondary
535 * device along with the primary one.
536 */
537 static int
epair_clone_match(struct if_clone * ifc,const char * name)538 epair_clone_match(struct if_clone *ifc, const char *name)
539 {
540 const char *cp;
541
542 /*
543 * Our base name is epair.
544 * Our interfaces will be named epair<n>[ab].
545 * So accept anything of the following list:
546 * - epair
547 * - epair<n>
548 * but not the epair<n>[ab] versions.
549 */
550 if (strncmp(epairname, name, sizeof(epairname)-1) != 0)
551 return (0);
552
553 for (cp = name + sizeof(epairname) - 1; *cp != '\0'; cp++) {
554 if (*cp < '0' || *cp > '9')
555 return (0);
556 }
557
558 return (1);
559 }
560
561 static void
epair_generate_mac_byname(struct epair_softc * sc,uint8_t eaddr[])562 epair_generate_mac_byname(struct epair_softc *sc, uint8_t eaddr[])
563 {
564 struct ether_addr gen_eaddr;
565 int i;
566
567 ether_gen_addr_byname(if_name(sc->ifp), &gen_eaddr);
568 for (i = 0; i < ETHER_ADDR_LEN; i++)
569 eaddr[i] = gen_eaddr.octet[i];
570 }
571
572 static void
epair_clone_add(struct if_clone * ifc,struct epair_softc * scb)573 epair_clone_add(struct if_clone *ifc, struct epair_softc *scb)
574 {
575 struct ifnet *ifp;
576 uint8_t eaddr[ETHER_ADDR_LEN]; /* 00:00:00:00:00:00 */
577
578 ifp = scb->ifp;
579 if (!use_ether_gen_addr) {
580 /* Copy epairNa etheraddr and change the last byte. */
581 memcpy(eaddr, scb->oifp->if_hw_addr, ETHER_ADDR_LEN);
582 eaddr[5] = 0x0b;
583 } else
584 epair_generate_mac_byname(scb, eaddr);
585 ether_ifattach(ifp, eaddr);
586
587 if_clone_addif(ifc, ifp);
588 }
589
590 static struct epair_softc *
epair_alloc_sc(struct if_clone * ifc)591 epair_alloc_sc(struct if_clone *ifc)
592 {
593 struct epair_softc *sc;
594
595 struct ifnet *ifp = if_alloc(IFT_ETHER);
596 sc = malloc(sizeof(struct epair_softc), M_EPAIR, M_WAITOK | M_ZERO);
597 sc->ifp = ifp;
598 sc->num_queues = epair_tasks.tasks;
599 sc->queues = mallocarray(sc->num_queues, sizeof(struct epair_queue),
600 M_EPAIR, M_WAITOK);
601 for (int i = 0; i < sc->num_queues; i++) {
602 struct epair_queue *q = &sc->queues[i];
603 q->id = i;
604 q->state = EPAIR_QUEUE_IDLE;
605 mtx_init(&q->mtx, "epairq", NULL, MTX_DEF | MTX_NEW);
606 mbufq_init(&q->q, RXRSIZE);
607 q->sc = sc;
608 NET_TASK_INIT(&q->tx_task, 0, epair_tx_start_deferred, q);
609 }
610
611 /* Initialise pseudo media types. */
612 ifmedia_init(&sc->media, 0, epair_media_change, epair_media_status);
613 ifmedia_add(&sc->media, IFM_ETHER | IFM_10G_T, 0, NULL);
614 ifmedia_set(&sc->media, IFM_ETHER | IFM_10G_T);
615
616 return (sc);
617 }
618
619 static void
epair_setup_ifp(struct epair_softc * sc,char * name,int unit)620 epair_setup_ifp(struct epair_softc *sc, char *name, int unit)
621 {
622 struct ifnet *ifp = sc->ifp;
623
624 ifp->if_softc = sc;
625 strlcpy(ifp->if_xname, name, IFNAMSIZ);
626 ifp->if_dname = epairname;
627 ifp->if_dunit = unit;
628 ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
629 ifp->if_capabilities = IFCAP_VLAN_MTU | IFCAP_TXCSUM |
630 IFCAP_TXCSUM_IPV6 | IFCAP_RXCSUM | IFCAP_RXCSUM_IPV6;
631 ifp->if_capenable = IFCAP_VLAN_MTU | IFCAP_TXCSUM |
632 IFCAP_TXCSUM_IPV6 | IFCAP_RXCSUM | IFCAP_RXCSUM_IPV6;
633 epair_caps_changed(ifp);
634 ifp->if_transmit = epair_transmit;
635 ifp->if_qflush = epair_qflush;
636 ifp->if_start = epair_start;
637 ifp->if_ioctl = epair_ioctl;
638 ifp->if_init = epair_init;
639 if_setsendqlen(ifp, ifqmaxlen);
640 if_setsendqready(ifp);
641
642 ifp->if_baudrate = IF_Gbps(10); /* arbitrary maximum */
643 }
644
645 static void
epair_generate_mac(struct epair_softc * sc,uint8_t * eaddr)646 epair_generate_mac(struct epair_softc *sc, uint8_t *eaddr)
647 {
648 uint32_t key[3];
649 uint32_t hash;
650 uint64_t hostid;
651
652 EPAIR_LOCK();
653 #ifdef SMP
654 /* Get an approximate distribution. */
655 hash = next_index % mp_ncpus;
656 #else
657 hash = 0;
658 #endif
659 EPAIR_UNLOCK();
660
661 /*
662 * Calculate the etheraddr hashing the hostid and the
663 * interface index. The result would be hopefully unique.
664 * Note that the "a" component of an epair instance may get moved
665 * to a different VNET after creation. In that case its index
666 * will be freed and the index can get reused by new epair instance.
667 * Make sure we do not create same etheraddr again.
668 */
669 getcredhostid(curthread->td_ucred, (unsigned long *)&hostid);
670 if (hostid == 0)
671 arc4rand(&hostid, sizeof(hostid), 0);
672
673 struct ifnet *ifp = sc->ifp;
674 EPAIR_LOCK();
675 if (ifp->if_index > next_index)
676 next_index = ifp->if_index;
677 else
678 next_index++;
679
680 key[0] = (uint32_t)next_index;
681 EPAIR_UNLOCK();
682 key[1] = (uint32_t)(hostid & 0xffffffff);
683 key[2] = (uint32_t)((hostid >> 32) & 0xfffffffff);
684 hash = jenkins_hash32(key, 3, 0);
685
686 eaddr[0] = 0x02;
687 memcpy(&eaddr[1], &hash, 4);
688 eaddr[5] = 0x0a;
689 }
690
691 static void
epair_free_sc(struct epair_softc * sc)692 epair_free_sc(struct epair_softc *sc)
693 {
694
695 if_free(sc->ifp);
696 ifmedia_removeall(&sc->media);
697 for (int i = 0; i < sc->num_queues; i++) {
698 struct epair_queue *q = &sc->queues[i];
699 mtx_destroy(&q->mtx);
700 }
701 free(sc->queues, M_EPAIR);
702 free(sc, M_EPAIR);
703 }
704
705 static void
epair_set_state(struct ifnet * ifp,bool running)706 epair_set_state(struct ifnet *ifp, bool running)
707 {
708 if (running) {
709 ifp->if_drv_flags |= IFF_DRV_RUNNING;
710 if_link_state_change(ifp, LINK_STATE_UP);
711 } else {
712 if_link_state_change(ifp, LINK_STATE_DOWN);
713 ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
714 }
715 }
716
717 static int
epair_handle_unit(struct if_clone * ifc,char * name,size_t len,int * punit)718 epair_handle_unit(struct if_clone *ifc, char *name, size_t len, int *punit)
719 {
720 int error = 0, unit, wildcard;
721 char *dp;
722
723 /* Try to see if a special unit was requested. */
724 error = ifc_name2unit(name, &unit);
725 if (error != 0)
726 return (error);
727 wildcard = (unit < 0);
728
729 error = ifc_alloc_unit(ifc, &unit);
730 if (error != 0)
731 return (error);
732
733 /*
734 * If no unit had been given, we need to adjust the ifName.
735 * Also make sure there is space for our extra [ab] suffix.
736 */
737 for (dp = name; *dp != '\0'; dp++);
738 if (wildcard) {
739 int slen = snprintf(dp, len - (dp - name), "%d", unit);
740 if (slen > len - (dp - name) - 1) {
741 /* ifName too long. */
742 error = ENOSPC;
743 goto done;
744 }
745 dp += slen;
746 }
747 if (len - (dp - name) - 1 < 1) {
748 /* No space left for our [ab] suffix. */
749 error = ENOSPC;
750 goto done;
751 }
752 *dp = 'b';
753 /* Must not change dp so we can replace 'a' by 'b' later. */
754 *(dp+1) = '\0';
755
756 /* Check if 'a' and 'b' interfaces already exist. */
757 if (ifunit(name) != NULL) {
758 error = EEXIST;
759 goto done;
760 }
761
762 *dp = 'a';
763 if (ifunit(name) != NULL) {
764 error = EEXIST;
765 goto done;
766 }
767 *punit = unit;
768 done:
769 if (error != 0)
770 ifc_free_unit(ifc, unit);
771
772 return (error);
773 }
774
775 static int
epair_clone_create(struct if_clone * ifc,char * name,size_t len,struct ifc_data * ifd,struct ifnet ** ifpp)776 epair_clone_create(struct if_clone *ifc, char *name, size_t len,
777 struct ifc_data *ifd, struct ifnet **ifpp)
778 {
779 struct epair_softc *sca, *scb;
780 struct ifnet *ifp;
781 char *dp;
782 int error, unit;
783 uint8_t eaddr[ETHER_ADDR_LEN]; /* 00:00:00:00:00:00 */
784
785 error = epair_handle_unit(ifc, name, len, &unit);
786 if (error != 0)
787 return (error);
788
789 /* Allocate memory for both [ab] interfaces */
790 sca = epair_alloc_sc(ifc);
791 scb = epair_alloc_sc(ifc);
792
793 /*
794 * Cross-reference the interfaces so we will be able to free both.
795 */
796 sca->oifp = scb->ifp;
797 scb->oifp = sca->ifp;
798
799 /* Finish initialization of interface <n>a. */
800 ifp = sca->ifp;
801 epair_setup_ifp(sca, name, unit);
802 if (!use_ether_gen_addr)
803 epair_generate_mac(sca, eaddr);
804 else
805 epair_generate_mac_byname(sca, eaddr);
806
807 ether_ifattach(ifp, eaddr);
808
809 /* Swap the name and finish initialization of interface <n>b. */
810 dp = name + strlen(name) - 1;
811 *dp = 'b';
812
813 epair_setup_ifp(scb, name, unit);
814
815 ifp = scb->ifp;
816 /* We need to play some tricks here for the second interface. */
817 strlcpy(name, epairname, len);
818 /* Correctly set the name for the cloner list. */
819 strlcpy(name, scb->ifp->if_xname, len);
820
821 epair_clone_add(ifc, scb);
822
823 /*
824 * Restore name to <n>a as the ifp for this will go into the
825 * cloner list for the initial call.
826 */
827 strlcpy(name, sca->ifp->if_xname, len);
828
829 /* Tell the world, that we are ready to rock. */
830 epair_set_state(sca->ifp, true);
831 epair_set_state(scb->ifp, true);
832
833 *ifpp = sca->ifp;
834
835 return (0);
836 }
837
838 static void
epair_drain_rings(struct epair_softc * sc)839 epair_drain_rings(struct epair_softc *sc)
840 {
841 for (int i = 0; i < sc->num_queues; i++) {
842 struct epair_queue *q;
843 struct mbuf *m, *n;
844
845 q = &sc->queues[i];
846 mtx_lock(&q->mtx);
847 m = mbufq_flush(&q->q);
848 mtx_unlock(&q->mtx);
849
850 for (; m != NULL; m = n) {
851 n = m->m_nextpkt;
852 m_freem(m);
853 }
854 }
855 }
856
857 static int
epair_clone_destroy(struct if_clone * ifc,struct ifnet * ifp,uint32_t flags)858 epair_clone_destroy(struct if_clone *ifc, struct ifnet *ifp, uint32_t flags)
859 {
860 struct ifnet *oifp;
861 struct epair_softc *sca, *scb;
862 int unit, error;
863
864 /*
865 * In case we called into if_clone_destroyif() ourselves
866 * again to remove the second interface, the softc will be
867 * NULL. In that case so not do anything but return success.
868 */
869 if (ifp->if_softc == NULL)
870 return (0);
871
872 unit = ifp->if_dunit;
873 sca = ifp->if_softc;
874 oifp = sca->oifp;
875 scb = oifp->if_softc;
876
877 /* Frist get the interfaces down and detached. */
878 epair_set_state(ifp, false);
879 epair_set_state(oifp, false);
880
881 ether_ifdetach(ifp);
882 ether_ifdetach(oifp);
883
884 /* Third free any queued packets and all the resources. */
885 CURVNET_SET_QUIET(oifp->if_vnet);
886 epair_drain_rings(scb);
887 oifp->if_softc = NULL;
888 error = if_clone_destroyif(ifc, oifp);
889 if (error)
890 panic("%s: if_clone_destroyif() for our 2nd iface failed: %d",
891 __func__, error);
892 epair_free_sc(scb);
893 CURVNET_RESTORE();
894
895 epair_drain_rings(sca);
896 epair_free_sc(sca);
897
898 /* Last free the cloner unit. */
899 ifc_free_unit(ifc, unit);
900
901 return (0);
902 }
903
904 static void
vnet_epair_init(const void * unused __unused)905 vnet_epair_init(const void *unused __unused)
906 {
907 struct if_clone_addreq req = {
908 .match_f = epair_clone_match,
909 .create_f = epair_clone_create,
910 .destroy_f = epair_clone_destroy,
911 };
912 V_epair_cloner = ifc_attach_cloner(epairname, &req);
913 }
914 VNET_SYSINIT(vnet_epair_init, SI_SUB_PSEUDO, SI_ORDER_ANY,
915 vnet_epair_init, NULL);
916
917 static void
vnet_epair_uninit(const void * unused __unused)918 vnet_epair_uninit(const void *unused __unused)
919 {
920
921 ifc_detach_cloner(V_epair_cloner);
922 }
923 VNET_SYSUNINIT(vnet_epair_uninit, SI_SUB_INIT_IF, SI_ORDER_ANY,
924 vnet_epair_uninit, NULL);
925
926 static int
epair_mod_init(void)927 epair_mod_init(void)
928 {
929 char name[32];
930 epair_tasks.tasks = 0;
931
932 #ifdef RSS
933 int cpu;
934
935 CPU_FOREACH(cpu) {
936 cpuset_t cpu_mask;
937
938 /* Pin to this CPU so we get appropriate NUMA allocations. */
939 thread_lock(curthread);
940 sched_bind(curthread, cpu);
941 thread_unlock(curthread);
942
943 snprintf(name, sizeof(name), "epair_task_%d", cpu);
944
945 epair_tasks.tq[cpu] = taskqueue_create(name, M_WAITOK,
946 taskqueue_thread_enqueue,
947 &epair_tasks.tq[cpu]);
948 CPU_SETOF(cpu, &cpu_mask);
949 taskqueue_start_threads_cpuset(&epair_tasks.tq[cpu], 1, PI_NET,
950 &cpu_mask, "%s", name);
951
952 epair_tasks.tasks++;
953 }
954 thread_lock(curthread);
955 sched_unbind(curthread);
956 thread_unlock(curthread);
957 #else
958 snprintf(name, sizeof(name), "epair_task");
959
960 epair_tasks.tq[0] = taskqueue_create(name, M_WAITOK,
961 taskqueue_thread_enqueue,
962 &epair_tasks.tq[0]);
963 taskqueue_start_threads(&epair_tasks.tq[0], 1, PI_NET, "%s", name);
964
965 epair_tasks.tasks = 1;
966 #endif
967
968 return (0);
969 }
970
971 static void
epair_mod_cleanup(void)972 epair_mod_cleanup(void)
973 {
974
975 for (int i = 0; i < epair_tasks.tasks; i++) {
976 taskqueue_drain_all(epair_tasks.tq[i]);
977 taskqueue_free(epair_tasks.tq[i]);
978 }
979 }
980
981 static int
epair_modevent(module_t mod,int type,void * data)982 epair_modevent(module_t mod, int type, void *data)
983 {
984 int ret;
985
986 switch (type) {
987 case MOD_LOAD:
988 EPAIR_LOCK_INIT();
989 ret = epair_mod_init();
990 if (ret != 0)
991 return (ret);
992 if (bootverbose)
993 printf("%s: %s initialized.\n", __func__, epairname);
994 break;
995 case MOD_UNLOAD:
996 epair_mod_cleanup();
997 EPAIR_LOCK_DESTROY();
998 if (bootverbose)
999 printf("%s: %s unloaded.\n", __func__, epairname);
1000 break;
1001 default:
1002 return (EOPNOTSUPP);
1003 }
1004 return (0);
1005 }
1006
1007 static moduledata_t epair_mod = {
1008 "if_epair",
1009 epair_modevent,
1010 0
1011 };
1012
1013 DECLARE_MODULE(if_epair, epair_mod, SI_SUB_PSEUDO, SI_ORDER_MIDDLE);
1014 MODULE_VERSION(if_epair, 3);
1015