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/taskqueue.h>
62
63 #include <net/bpf.h>
64 #include <net/ethernet.h>
65 #include <net/if.h>
66 #include <net/if_var.h>
67 #include <net/if_clone.h>
68 #include <net/if_media.h>
69 #include <net/if_var.h>
70 #include <net/if_private.h>
71 #include <net/if_types.h>
72 #include <net/netisr.h>
73 #ifdef RSS
74 #include <net/rss_config.h>
75 #ifdef INET
76 #include <netinet/in_rss.h>
77 #endif
78 #ifdef INET6
79 #include <netinet6/in6_rss.h>
80 #endif
81 #endif
82 #include <net/vnet.h>
83
84 static const char epairname[] = "epair";
85 #define RXRSIZE 4096 /* Probably overkill by 4-8x. */
86
87 static MALLOC_DEFINE(M_EPAIR, epairname,
88 "Pair of virtual cross-over connected Ethernet-like interfaces");
89
90 VNET_DEFINE_STATIC(struct if_clone *, epair_cloner);
91 #define V_epair_cloner VNET(epair_cloner)
92
93 static unsigned int next_index = 0;
94 #define EPAIR_LOCK_INIT() mtx_init(&epair_n_index_mtx, "epairidx", \
95 NULL, MTX_DEF)
96 #define EPAIR_LOCK_DESTROY() mtx_destroy(&epair_n_index_mtx)
97 #define EPAIR_LOCK() mtx_lock(&epair_n_index_mtx)
98 #define EPAIR_UNLOCK() mtx_unlock(&epair_n_index_mtx)
99
100 struct epair_softc;
101 struct epair_queue {
102 struct mtx mtx;
103 struct mbufq q;
104 int id;
105 enum {
106 EPAIR_QUEUE_IDLE,
107 EPAIR_QUEUE_WAKING,
108 EPAIR_QUEUE_RUNNING,
109 } state;
110 struct task tx_task;
111 struct epair_softc *sc;
112 };
113
114 static struct mtx epair_n_index_mtx;
115 struct epair_softc {
116 struct ifnet *ifp; /* This ifp. */
117 struct ifnet *oifp; /* other ifp of pair. */
118 int num_queues;
119 struct epair_queue *queues;
120 struct ifmedia media; /* Media config (fake). */
121 STAILQ_ENTRY(epair_softc) entry;
122 };
123
124 struct epair_tasks_t {
125 int tasks;
126 struct taskqueue *tq[MAXCPU];
127 };
128
129 static struct epair_tasks_t epair_tasks;
130
131 static void
epair_clear_mbuf(struct mbuf * m)132 epair_clear_mbuf(struct mbuf *m)
133 {
134 M_ASSERTPKTHDR(m);
135
136 /* Remove any CSUM_SND_TAG as ether_input will barf. */
137 if (m->m_pkthdr.csum_flags & CSUM_SND_TAG) {
138 m_snd_tag_rele(m->m_pkthdr.snd_tag);
139 m->m_pkthdr.snd_tag = NULL;
140 m->m_pkthdr.csum_flags &= ~CSUM_SND_TAG;
141 }
142
143 /* Clear vlan information. */
144 m->m_flags &= ~M_VLANTAG;
145 m->m_pkthdr.ether_vtag = 0;
146
147 m_tag_delete_nonpersistent(m);
148 }
149
150 static void
epair_tx_start_deferred(void * arg,int pending)151 epair_tx_start_deferred(void *arg, int pending)
152 {
153 struct epair_queue *q = (struct epair_queue *)arg;
154 if_t ifp;
155 struct mbuf *m, *n;
156 bool resched;
157
158 ifp = q->sc->ifp;
159
160 if_ref(ifp);
161 CURVNET_SET(ifp->if_vnet);
162
163 mtx_lock(&q->mtx);
164 m = mbufq_flush(&q->q);
165 q->state = EPAIR_QUEUE_RUNNING;
166 mtx_unlock(&q->mtx);
167
168 while (m != NULL) {
169 n = STAILQ_NEXT(m, m_stailqpkt);
170 m->m_nextpkt = NULL;
171 if_input(ifp, m);
172 m = n;
173 }
174
175 /*
176 * Avoid flushing the queue more than once per task. We can otherwise
177 * end up starving ourselves in a multi-epair routing configuration.
178 */
179 mtx_lock(&q->mtx);
180 if (!mbufq_empty(&q->q)) {
181 resched = true;
182 q->state = EPAIR_QUEUE_WAKING;
183 } else {
184 resched = false;
185 q->state = EPAIR_QUEUE_IDLE;
186 }
187 mtx_unlock(&q->mtx);
188
189 if (resched)
190 taskqueue_enqueue(epair_tasks.tq[q->id], &q->tx_task);
191
192 CURVNET_RESTORE();
193 if_rele(ifp);
194 }
195
196 static struct epair_queue *
epair_select_queue(struct epair_softc * sc,struct mbuf * m)197 epair_select_queue(struct epair_softc *sc, struct mbuf *m)
198 {
199 uint32_t bucket;
200 #ifdef RSS
201 struct ether_header *eh;
202 int ret;
203
204 ret = rss_m2bucket(m, &bucket);
205 if (ret) {
206 /* Actually hash the packet. */
207 eh = mtod(m, struct ether_header *);
208
209 switch (ntohs(eh->ether_type)) {
210 #ifdef INET
211 case ETHERTYPE_IP:
212 rss_soft_m2cpuid_v4(m, 0, &bucket);
213 break;
214 #endif
215 #ifdef INET6
216 case ETHERTYPE_IPV6:
217 rss_soft_m2cpuid_v6(m, 0, &bucket);
218 break;
219 #endif
220 default:
221 bucket = 0;
222 break;
223 }
224 }
225 bucket %= sc->num_queues;
226 #else
227 bucket = 0;
228 #endif
229 return (&sc->queues[bucket]);
230 }
231
232 static void
epair_prepare_mbuf(struct mbuf * m,struct ifnet * src_ifp)233 epair_prepare_mbuf(struct mbuf *m, struct ifnet *src_ifp)
234 {
235 M_ASSERTPKTHDR(m);
236 epair_clear_mbuf(m);
237 if_setrcvif(m, src_ifp);
238 M_SETFIB(m, src_ifp->if_fib);
239
240 MPASS(m->m_nextpkt == NULL);
241 MPASS((m->m_pkthdr.csum_flags & CSUM_SND_TAG) == 0);
242 }
243
244 static void
epair_menq(struct mbuf * m,struct epair_softc * osc)245 epair_menq(struct mbuf *m, struct epair_softc *osc)
246 {
247 struct epair_queue *q;
248 struct ifnet *ifp, *oifp;
249 int error, len;
250 bool mcast;
251
252 /*
253 * I know this looks weird. We pass the "other sc" as we need that one
254 * and can get both ifps from it as well.
255 */
256 oifp = osc->ifp;
257 ifp = osc->oifp;
258
259 epair_prepare_mbuf(m, oifp);
260
261 /* Save values as once the mbuf is queued, it's not ours anymore. */
262 len = m->m_pkthdr.len;
263 mcast = (m->m_flags & (M_BCAST | M_MCAST)) != 0;
264
265 q = epair_select_queue(osc, m);
266
267 mtx_lock(&q->mtx);
268 if (q->state == EPAIR_QUEUE_IDLE) {
269 q->state = EPAIR_QUEUE_WAKING;
270 taskqueue_enqueue(epair_tasks.tq[q->id], &q->tx_task);
271 }
272 error = mbufq_enqueue(&q->q, m);
273 mtx_unlock(&q->mtx);
274
275 if (error != 0) {
276 m_freem(m);
277 if_inc_counter(ifp, IFCOUNTER_OQDROPS, 1);
278 } else {
279 if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);
280 if_inc_counter(ifp, IFCOUNTER_OBYTES, len);
281 if (mcast)
282 if_inc_counter(ifp, IFCOUNTER_OMCASTS, 1);
283 if_inc_counter(oifp, IFCOUNTER_IPACKETS, 1);
284 }
285 }
286
287 static void
epair_start(struct ifnet * ifp)288 epair_start(struct ifnet *ifp)
289 {
290 struct mbuf *m;
291 struct epair_softc *sc;
292 struct ifnet *oifp;
293
294 /*
295 * We get packets here from ether_output via if_handoff()
296 * and need to put them into the input queue of the oifp
297 * and will put the packet into the receive-queue (rxq) of the
298 * other interface (oifp) of our pair.
299 */
300 sc = ifp->if_softc;
301 oifp = sc->oifp;
302 sc = oifp->if_softc;
303 for (;;) {
304 IFQ_DEQUEUE(&ifp->if_snd, m);
305 if (m == NULL)
306 break;
307 M_ASSERTPKTHDR(m);
308 BPF_MTAP(ifp, m);
309
310 /* In case either interface is not usable drop the packet. */
311 if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0 ||
312 (ifp->if_flags & IFF_UP) == 0 ||
313 (oifp->if_drv_flags & IFF_DRV_RUNNING) == 0 ||
314 (oifp->if_flags & IFF_UP) == 0) {
315 m_freem(m);
316 continue;
317 }
318
319 epair_menq(m, sc);
320 }
321 }
322
323 static int
epair_transmit(struct ifnet * ifp,struct mbuf * m)324 epair_transmit(struct ifnet *ifp, struct mbuf *m)
325 {
326 struct epair_softc *sc;
327 struct ifnet *oifp;
328 #ifdef ALTQ
329 int len;
330 bool mcast;
331 #endif
332
333 if (m == NULL)
334 return (0);
335 M_ASSERTPKTHDR(m);
336
337 /*
338 * We could just transmit this, but it makes testing easier if we're a
339 * little bit more like real hardware.
340 * Allow just that little bit extra for ethernet (and vlan) headers.
341 */
342 if (m->m_pkthdr.len > (ifp->if_mtu + sizeof(struct ether_vlan_header))) {
343 m_freem(m);
344 if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
345 return (E2BIG);
346 }
347
348 /*
349 * We are not going to use the interface en/dequeue mechanism
350 * on the TX side. We are called from ether_output_frame()
351 * and will put the packet into the receive-queue (rxq) of the
352 * other interface (oifp) of our pair.
353 */
354 if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) {
355 m_freem(m);
356 if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
357 return (ENXIO);
358 }
359 if ((ifp->if_flags & IFF_UP) == 0) {
360 m_freem(m);
361 if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
362 return (ENETDOWN);
363 }
364
365 BPF_MTAP(ifp, m);
366
367 /*
368 * In case the outgoing interface is not usable,
369 * drop the packet.
370 */
371 sc = ifp->if_softc;
372 oifp = sc->oifp;
373 if ((oifp->if_drv_flags & IFF_DRV_RUNNING) == 0 ||
374 (oifp->if_flags & IFF_UP) == 0) {
375 if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
376 m_freem(m);
377 return (0);
378 }
379
380 #ifdef ALTQ
381 len = m->m_pkthdr.len;
382 mcast = (m->m_flags & (M_BCAST | M_MCAST)) != 0;
383 int error = 0;
384
385 /* Support ALTQ via the classic if_start() path. */
386 IF_LOCK(&ifp->if_snd);
387 if (ALTQ_IS_ENABLED(&ifp->if_snd)) {
388 ALTQ_ENQUEUE(&ifp->if_snd, m, NULL, error);
389 if (error)
390 if_inc_counter(ifp, IFCOUNTER_OQDROPS, 1);
391 IF_UNLOCK(&ifp->if_snd);
392 if (!error) {
393 if_inc_counter(ifp, IFCOUNTER_OBYTES, len);
394 if (mcast)
395 if_inc_counter(ifp, IFCOUNTER_OMCASTS, 1);
396 epair_start(ifp);
397 }
398 return (error);
399 }
400 IF_UNLOCK(&ifp->if_snd);
401 #endif
402
403 epair_menq(m, oifp->if_softc);
404 return (0);
405 }
406
407 static void
epair_qflush(struct ifnet * ifp __unused)408 epair_qflush(struct ifnet *ifp __unused)
409 {
410 }
411
412 static int
epair_media_change(struct ifnet * ifp __unused)413 epair_media_change(struct ifnet *ifp __unused)
414 {
415
416 /* Do nothing. */
417 return (0);
418 }
419
420 static void
epair_media_status(struct ifnet * ifp __unused,struct ifmediareq * imr)421 epair_media_status(struct ifnet *ifp __unused, struct ifmediareq *imr)
422 {
423
424 imr->ifm_status = IFM_AVALID | IFM_ACTIVE;
425 imr->ifm_active = IFM_ETHER | IFM_10G_T | IFM_FDX;
426 }
427
428 static int
epair_ioctl(struct ifnet * ifp,u_long cmd,caddr_t data)429 epair_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
430 {
431 struct epair_softc *sc;
432 struct ifreq *ifr;
433 int error;
434
435 ifr = (struct ifreq *)data;
436 switch (cmd) {
437 case SIOCSIFFLAGS:
438 case SIOCADDMULTI:
439 case SIOCDELMULTI:
440 error = 0;
441 break;
442
443 case SIOCSIFMEDIA:
444 case SIOCGIFMEDIA:
445 sc = ifp->if_softc;
446 error = ifmedia_ioctl(ifp, ifr, &sc->media, cmd);
447 break;
448
449 case SIOCSIFMTU:
450 /* We basically allow all kinds of MTUs. */
451 ifp->if_mtu = ifr->ifr_mtu;
452 error = 0;
453 break;
454
455 default:
456 /* Let the common ethernet handler process this. */
457 error = ether_ioctl(ifp, cmd, data);
458 break;
459 }
460
461 return (error);
462 }
463
464 static void
epair_init(void * dummy __unused)465 epair_init(void *dummy __unused)
466 {
467 }
468
469 /*
470 * Interface cloning functions.
471 * We use our private ones so that we can create/destroy our secondary
472 * device along with the primary one.
473 */
474 static int
epair_clone_match(struct if_clone * ifc,const char * name)475 epair_clone_match(struct if_clone *ifc, const char *name)
476 {
477 const char *cp;
478
479 /*
480 * Our base name is epair.
481 * Our interfaces will be named epair<n>[ab].
482 * So accept anything of the following list:
483 * - epair
484 * - epair<n>
485 * but not the epair<n>[ab] versions.
486 */
487 if (strncmp(epairname, name, sizeof(epairname)-1) != 0)
488 return (0);
489
490 for (cp = name + sizeof(epairname) - 1; *cp != '\0'; cp++) {
491 if (*cp < '0' || *cp > '9')
492 return (0);
493 }
494
495 return (1);
496 }
497
498 static void
epair_clone_add(struct if_clone * ifc,struct epair_softc * scb)499 epair_clone_add(struct if_clone *ifc, struct epair_softc *scb)
500 {
501 struct ifnet *ifp;
502 uint8_t eaddr[ETHER_ADDR_LEN]; /* 00:00:00:00:00:00 */
503
504 ifp = scb->ifp;
505 /* Copy epairNa etheraddr and change the last byte. */
506 memcpy(eaddr, scb->oifp->if_hw_addr, ETHER_ADDR_LEN);
507 eaddr[5] = 0x0b;
508 ether_ifattach(ifp, eaddr);
509
510 if_clone_addif(ifc, ifp);
511 }
512
513 static struct epair_softc *
epair_alloc_sc(struct if_clone * ifc)514 epair_alloc_sc(struct if_clone *ifc)
515 {
516 struct epair_softc *sc;
517
518 struct ifnet *ifp = if_alloc(IFT_ETHER);
519 if (ifp == NULL)
520 return (NULL);
521
522 sc = malloc(sizeof(struct epair_softc), M_EPAIR, M_WAITOK | M_ZERO);
523 sc->ifp = ifp;
524 sc->num_queues = epair_tasks.tasks;
525 sc->queues = mallocarray(sc->num_queues, sizeof(struct epair_queue),
526 M_EPAIR, M_WAITOK);
527 for (int i = 0; i < sc->num_queues; i++) {
528 struct epair_queue *q = &sc->queues[i];
529 q->id = i;
530 q->state = EPAIR_QUEUE_IDLE;
531 mtx_init(&q->mtx, "epairq", NULL, MTX_DEF | MTX_NEW);
532 mbufq_init(&q->q, RXRSIZE);
533 q->sc = sc;
534 NET_TASK_INIT(&q->tx_task, 0, epair_tx_start_deferred, q);
535 }
536
537 /* Initialise pseudo media types. */
538 ifmedia_init(&sc->media, 0, epair_media_change, epair_media_status);
539 ifmedia_add(&sc->media, IFM_ETHER | IFM_10G_T, 0, NULL);
540 ifmedia_set(&sc->media, IFM_ETHER | IFM_10G_T);
541
542 return (sc);
543 }
544
545 static void
epair_setup_ifp(struct epair_softc * sc,char * name,int unit)546 epair_setup_ifp(struct epair_softc *sc, char *name, int unit)
547 {
548 struct ifnet *ifp = sc->ifp;
549
550 ifp->if_softc = sc;
551 strlcpy(ifp->if_xname, name, IFNAMSIZ);
552 ifp->if_dname = epairname;
553 ifp->if_dunit = unit;
554 ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
555 ifp->if_capabilities = IFCAP_VLAN_MTU;
556 ifp->if_capenable = IFCAP_VLAN_MTU;
557 ifp->if_transmit = epair_transmit;
558 ifp->if_qflush = epair_qflush;
559 ifp->if_start = epair_start;
560 ifp->if_ioctl = epair_ioctl;
561 ifp->if_init = epair_init;
562 if_setsendqlen(ifp, ifqmaxlen);
563 if_setsendqready(ifp);
564
565 ifp->if_baudrate = IF_Gbps(10); /* arbitrary maximum */
566 }
567
568 static void
epair_generate_mac(struct epair_softc * sc,uint8_t * eaddr)569 epair_generate_mac(struct epair_softc *sc, uint8_t *eaddr)
570 {
571 uint32_t key[3];
572 uint32_t hash;
573 uint64_t hostid;
574
575 EPAIR_LOCK();
576 #ifdef SMP
577 /* Get an approximate distribution. */
578 hash = next_index % mp_ncpus;
579 #else
580 hash = 0;
581 #endif
582 EPAIR_UNLOCK();
583
584 /*
585 * Calculate the etheraddr hashing the hostid and the
586 * interface index. The result would be hopefully unique.
587 * Note that the "a" component of an epair instance may get moved
588 * to a different VNET after creation. In that case its index
589 * will be freed and the index can get reused by new epair instance.
590 * Make sure we do not create same etheraddr again.
591 */
592 getcredhostid(curthread->td_ucred, (unsigned long *)&hostid);
593 if (hostid == 0)
594 arc4rand(&hostid, sizeof(hostid), 0);
595
596 struct ifnet *ifp = sc->ifp;
597 EPAIR_LOCK();
598 if (ifp->if_index > next_index)
599 next_index = ifp->if_index;
600 else
601 next_index++;
602
603 key[0] = (uint32_t)next_index;
604 EPAIR_UNLOCK();
605 key[1] = (uint32_t)(hostid & 0xffffffff);
606 key[2] = (uint32_t)((hostid >> 32) & 0xfffffffff);
607 hash = jenkins_hash32(key, 3, 0);
608
609 eaddr[0] = 0x02;
610 memcpy(&eaddr[1], &hash, 4);
611 eaddr[5] = 0x0a;
612 }
613
614 static void
epair_free_sc(struct epair_softc * sc)615 epair_free_sc(struct epair_softc *sc)
616 {
617 if (sc == NULL)
618 return;
619
620 if_free(sc->ifp);
621 ifmedia_removeall(&sc->media);
622 for (int i = 0; i < sc->num_queues; i++) {
623 struct epair_queue *q = &sc->queues[i];
624 mtx_destroy(&q->mtx);
625 }
626 free(sc->queues, M_EPAIR);
627 free(sc, M_EPAIR);
628 }
629
630 static void
epair_set_state(struct ifnet * ifp,bool running)631 epair_set_state(struct ifnet *ifp, bool running)
632 {
633 if (running) {
634 ifp->if_drv_flags |= IFF_DRV_RUNNING;
635 if_link_state_change(ifp, LINK_STATE_UP);
636 } else {
637 if_link_state_change(ifp, LINK_STATE_DOWN);
638 ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
639 }
640 }
641
642 static int
epair_handle_unit(struct if_clone * ifc,char * name,size_t len,int * punit)643 epair_handle_unit(struct if_clone *ifc, char *name, size_t len, int *punit)
644 {
645 int error = 0, unit, wildcard;
646 char *dp;
647
648 /* Try to see if a special unit was requested. */
649 error = ifc_name2unit(name, &unit);
650 if (error != 0)
651 return (error);
652 wildcard = (unit < 0);
653
654 error = ifc_alloc_unit(ifc, &unit);
655 if (error != 0)
656 return (error);
657
658 /*
659 * If no unit had been given, we need to adjust the ifName.
660 * Also make sure there is space for our extra [ab] suffix.
661 */
662 for (dp = name; *dp != '\0'; dp++);
663 if (wildcard) {
664 int slen = snprintf(dp, len - (dp - name), "%d", unit);
665 if (slen > len - (dp - name) - 1) {
666 /* ifName too long. */
667 error = ENOSPC;
668 goto done;
669 }
670 dp += slen;
671 }
672 if (len - (dp - name) - 1 < 1) {
673 /* No space left for our [ab] suffix. */
674 error = ENOSPC;
675 goto done;
676 }
677 *dp = 'b';
678 /* Must not change dp so we can replace 'a' by 'b' later. */
679 *(dp+1) = '\0';
680
681 /* Check if 'a' and 'b' interfaces already exist. */
682 if (ifunit(name) != NULL) {
683 error = EEXIST;
684 goto done;
685 }
686
687 *dp = 'a';
688 if (ifunit(name) != NULL) {
689 error = EEXIST;
690 goto done;
691 }
692 *punit = unit;
693 done:
694 if (error != 0)
695 ifc_free_unit(ifc, unit);
696
697 return (error);
698 }
699
700 static int
epair_clone_create(struct if_clone * ifc,char * name,size_t len,struct ifc_data * ifd,struct ifnet ** ifpp)701 epair_clone_create(struct if_clone *ifc, char *name, size_t len,
702 struct ifc_data *ifd, struct ifnet **ifpp)
703 {
704 struct epair_softc *sca, *scb;
705 struct ifnet *ifp;
706 char *dp;
707 int error, unit;
708 uint8_t eaddr[ETHER_ADDR_LEN]; /* 00:00:00:00:00:00 */
709
710 error = epair_handle_unit(ifc, name, len, &unit);
711 if (error != 0)
712 return (error);
713
714 /* Allocate memory for both [ab] interfaces */
715 sca = epair_alloc_sc(ifc);
716 scb = epair_alloc_sc(ifc);
717 if (sca == NULL || scb == NULL) {
718 epair_free_sc(sca);
719 epair_free_sc(scb);
720 ifc_free_unit(ifc, unit);
721 return (ENOSPC);
722 }
723
724 /*
725 * Cross-reference the interfaces so we will be able to free both.
726 */
727 sca->oifp = scb->ifp;
728 scb->oifp = sca->ifp;
729
730 /* Finish initialization of interface <n>a. */
731 ifp = sca->ifp;
732 epair_setup_ifp(sca, name, unit);
733 epair_generate_mac(sca, eaddr);
734
735 ether_ifattach(ifp, eaddr);
736
737 /* Swap the name and finish initialization of interface <n>b. */
738 dp = name + strlen(name) - 1;
739 *dp = 'b';
740
741 epair_setup_ifp(scb, name, unit);
742
743 ifp = scb->ifp;
744 /* We need to play some tricks here for the second interface. */
745 strlcpy(name, epairname, len);
746 /* Correctly set the name for the cloner list. */
747 strlcpy(name, scb->ifp->if_xname, len);
748
749 epair_clone_add(ifc, scb);
750
751 /*
752 * Restore name to <n>a as the ifp for this will go into the
753 * cloner list for the initial call.
754 */
755 strlcpy(name, sca->ifp->if_xname, len);
756
757 /* Tell the world, that we are ready to rock. */
758 epair_set_state(sca->ifp, true);
759 epair_set_state(scb->ifp, true);
760
761 *ifpp = sca->ifp;
762
763 return (0);
764 }
765
766 static void
epair_drain_rings(struct epair_softc * sc)767 epair_drain_rings(struct epair_softc *sc)
768 {
769 for (int i = 0; i < sc->num_queues; i++) {
770 struct epair_queue *q;
771 struct mbuf *m, *n;
772
773 q = &sc->queues[i];
774 mtx_lock(&q->mtx);
775 m = mbufq_flush(&q->q);
776 mtx_unlock(&q->mtx);
777
778 for (; m != NULL; m = n) {
779 n = m->m_nextpkt;
780 m_freem(m);
781 }
782 }
783 }
784
785 static int
epair_clone_destroy(struct if_clone * ifc,struct ifnet * ifp,uint32_t flags)786 epair_clone_destroy(struct if_clone *ifc, struct ifnet *ifp, uint32_t flags)
787 {
788 struct ifnet *oifp;
789 struct epair_softc *sca, *scb;
790 int unit, error;
791
792 /*
793 * In case we called into if_clone_destroyif() ourselves
794 * again to remove the second interface, the softc will be
795 * NULL. In that case so not do anything but return success.
796 */
797 if (ifp->if_softc == NULL)
798 return (0);
799
800 unit = ifp->if_dunit;
801 sca = ifp->if_softc;
802 oifp = sca->oifp;
803 scb = oifp->if_softc;
804
805 /* Frist get the interfaces down and detached. */
806 epair_set_state(ifp, false);
807 epair_set_state(oifp, false);
808
809 ether_ifdetach(ifp);
810 ether_ifdetach(oifp);
811
812 /* Third free any queued packets and all the resources. */
813 CURVNET_SET_QUIET(oifp->if_vnet);
814 epair_drain_rings(scb);
815 oifp->if_softc = NULL;
816 error = if_clone_destroyif(ifc, oifp);
817 if (error)
818 panic("%s: if_clone_destroyif() for our 2nd iface failed: %d",
819 __func__, error);
820 epair_free_sc(scb);
821 CURVNET_RESTORE();
822
823 epair_drain_rings(sca);
824 epair_free_sc(sca);
825
826 /* Last free the cloner unit. */
827 ifc_free_unit(ifc, unit);
828
829 return (0);
830 }
831
832 static void
vnet_epair_init(const void * unused __unused)833 vnet_epair_init(const void *unused __unused)
834 {
835 struct if_clone_addreq req = {
836 .match_f = epair_clone_match,
837 .create_f = epair_clone_create,
838 .destroy_f = epair_clone_destroy,
839 };
840 V_epair_cloner = ifc_attach_cloner(epairname, &req);
841 }
842 VNET_SYSINIT(vnet_epair_init, SI_SUB_PSEUDO, SI_ORDER_ANY,
843 vnet_epair_init, NULL);
844
845 static void
vnet_epair_uninit(const void * unused __unused)846 vnet_epair_uninit(const void *unused __unused)
847 {
848
849 ifc_detach_cloner(V_epair_cloner);
850 }
851 VNET_SYSUNINIT(vnet_epair_uninit, SI_SUB_INIT_IF, SI_ORDER_ANY,
852 vnet_epair_uninit, NULL);
853
854 static int
epair_mod_init(void)855 epair_mod_init(void)
856 {
857 char name[32];
858 epair_tasks.tasks = 0;
859
860 #ifdef RSS
861 int cpu;
862
863 CPU_FOREACH(cpu) {
864 cpuset_t cpu_mask;
865
866 /* Pin to this CPU so we get appropriate NUMA allocations. */
867 thread_lock(curthread);
868 sched_bind(curthread, cpu);
869 thread_unlock(curthread);
870
871 snprintf(name, sizeof(name), "epair_task_%d", cpu);
872
873 epair_tasks.tq[cpu] = taskqueue_create(name, M_WAITOK,
874 taskqueue_thread_enqueue,
875 &epair_tasks.tq[cpu]);
876 CPU_SETOF(cpu, &cpu_mask);
877 taskqueue_start_threads_cpuset(&epair_tasks.tq[cpu], 1, PI_NET,
878 &cpu_mask, "%s", name);
879
880 epair_tasks.tasks++;
881 }
882 thread_lock(curthread);
883 sched_unbind(curthread);
884 thread_unlock(curthread);
885 #else
886 snprintf(name, sizeof(name), "epair_task");
887
888 epair_tasks.tq[0] = taskqueue_create(name, M_WAITOK,
889 taskqueue_thread_enqueue,
890 &epair_tasks.tq[0]);
891 taskqueue_start_threads(&epair_tasks.tq[0], 1, PI_NET, "%s", name);
892
893 epair_tasks.tasks = 1;
894 #endif
895
896 return (0);
897 }
898
899 static void
epair_mod_cleanup(void)900 epair_mod_cleanup(void)
901 {
902
903 for (int i = 0; i < epair_tasks.tasks; i++) {
904 taskqueue_drain_all(epair_tasks.tq[i]);
905 taskqueue_free(epair_tasks.tq[i]);
906 }
907 }
908
909 static int
epair_modevent(module_t mod,int type,void * data)910 epair_modevent(module_t mod, int type, void *data)
911 {
912 int ret;
913
914 switch (type) {
915 case MOD_LOAD:
916 EPAIR_LOCK_INIT();
917 ret = epair_mod_init();
918 if (ret != 0)
919 return (ret);
920 if (bootverbose)
921 printf("%s: %s initialized.\n", __func__, epairname);
922 break;
923 case MOD_UNLOAD:
924 epair_mod_cleanup();
925 EPAIR_LOCK_DESTROY();
926 if (bootverbose)
927 printf("%s: %s unloaded.\n", __func__, epairname);
928 break;
929 default:
930 return (EOPNOTSUPP);
931 }
932 return (0);
933 }
934
935 static moduledata_t epair_mod = {
936 "if_epair",
937 epair_modevent,
938 0
939 };
940
941 DECLARE_MODULE(if_epair, epair_mod, SI_SUB_PSEUDO, SI_ORDER_MIDDLE);
942 MODULE_VERSION(if_epair, 3);
943