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Linux 4.19.133
[linux/fpc-iii.git] / drivers / net / veth.c
blob2abbad1abaf2edf6824e8149c3e3cb250b22c0e2
1 /*
2 * drivers/net/veth.c
3 *
4 * Copyright (C) 2007 OpenVZ http://openvz.org, SWsoft Inc
5 *
6 * Author: Pavel Emelianov <xemul@openvz.org>
7 * Ethtool interface from: Eric W. Biederman <ebiederm@xmission.com>
8 *
9 */
10
11 #include <linux/netdevice.h>
12 #include <linux/slab.h>
13 #include <linux/ethtool.h>
14 #include <linux/etherdevice.h>
15 #include <linux/u64_stats_sync.h>
16
17 #include <net/rtnetlink.h>
18 #include <net/dst.h>
19 #include <net/xfrm.h>
20 #include <net/xdp.h>
21 #include <linux/veth.h>
22 #include <linux/module.h>
23 #include <linux/bpf.h>
24 #include <linux/filter.h>
25 #include <linux/ptr_ring.h>
26 #include <linux/bpf_trace.h>
27
28 #define DRV_NAME "veth"
29 #define DRV_VERSION "1.0"
30
31 #define VETH_XDP_FLAG BIT(0)
32 #define VETH_RING_SIZE 256
33 #define VETH_XDP_HEADROOM (XDP_PACKET_HEADROOM + NET_IP_ALIGN)
34
35 /* Separating two types of XDP xmit */
36 #define VETH_XDP_TX BIT(0)
37 #define VETH_XDP_REDIR BIT(1)
38
39 struct pcpu_vstats {
40 u64 packets;
41 u64 bytes;
42 struct u64_stats_sync syncp;
43 };
44
45 struct veth_rq {
46 struct napi_struct xdp_napi;
47 struct net_device *dev;
48 struct bpf_prog __rcu *xdp_prog;
49 struct xdp_mem_info xdp_mem;
50 bool rx_notify_masked;
51 struct ptr_ring xdp_ring;
52 struct xdp_rxq_info xdp_rxq;
53 };
54
55 struct veth_priv {
56 struct net_device __rcu *peer;
57 atomic64_t dropped;
58 struct bpf_prog *_xdp_prog;
59 struct veth_rq *rq;
60 unsigned int requested_headroom;
61 };
62
63 /*
64 * ethtool interface
65 */
66
67 static struct {
68 const char string[ETH_GSTRING_LEN];
69 } ethtool_stats_keys[] = {
70 { "peer_ifindex" },
71 };
72
73 static int veth_get_link_ksettings(struct net_device *dev,
74 struct ethtool_link_ksettings *cmd)
75 {
76 cmd->base.speed = SPEED_10000;
77 cmd->base.duplex = DUPLEX_FULL;
78 cmd->base.port = PORT_TP;
79 cmd->base.autoneg = AUTONEG_DISABLE;
80 return 0;
81 }
82
83 static void veth_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
84 {
85 strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
86 strlcpy(info->version, DRV_VERSION, sizeof(info->version));
87 }
88
89 static void veth_get_strings(struct net_device *dev, u32 stringset, u8 *buf)
90 {
91 switch(stringset) {
92 case ETH_SS_STATS:
93 memcpy(buf, &ethtool_stats_keys, sizeof(ethtool_stats_keys));
94 break;
95 }
96 }
97
98 static int veth_get_sset_count(struct net_device *dev, int sset)
99 {
100 switch (sset) {
101 case ETH_SS_STATS:
102 return ARRAY_SIZE(ethtool_stats_keys);
103 default:
104 return -EOPNOTSUPP;
105 }
106 }
107
108 static void veth_get_ethtool_stats(struct net_device *dev,
109 struct ethtool_stats *stats, u64 *data)
110 {
111 struct veth_priv *priv = netdev_priv(dev);
112 struct net_device *peer = rtnl_dereference(priv->peer);
113
114 data[0] = peer ? peer->ifindex : 0;
115 }
116
117 static const struct ethtool_ops veth_ethtool_ops = {
118 .get_drvinfo = veth_get_drvinfo,
119 .get_link = ethtool_op_get_link,
120 .get_strings = veth_get_strings,
121 .get_sset_count = veth_get_sset_count,
122 .get_ethtool_stats = veth_get_ethtool_stats,
123 .get_link_ksettings = veth_get_link_ksettings,
124 };
125
126 /* general routines */
127
128 static bool veth_is_xdp_frame(void *ptr)
129 {
130 return (unsigned long)ptr & VETH_XDP_FLAG;
131 }
132
133 static void *veth_ptr_to_xdp(void *ptr)
134 {
135 return (void *)((unsigned long)ptr & ~VETH_XDP_FLAG);
136 }
137
138 static void *veth_xdp_to_ptr(void *ptr)
139 {
140 return (void *)((unsigned long)ptr | VETH_XDP_FLAG);
141 }
142
143 static void veth_ptr_free(void *ptr)
144 {
145 if (veth_is_xdp_frame(ptr))
146 xdp_return_frame(veth_ptr_to_xdp(ptr));
147 else
148 kfree_skb(ptr);
149 }
150
151 static void __veth_xdp_flush(struct veth_rq *rq)
152 {
153 /* Write ptr_ring before reading rx_notify_masked */
154 smp_mb();
155 if (!rq->rx_notify_masked) {
156 rq->rx_notify_masked = true;
157 napi_schedule(&rq->xdp_napi);
158 }
159 }
160
161 static int veth_xdp_rx(struct veth_rq *rq, struct sk_buff *skb)
162 {
163 if (unlikely(ptr_ring_produce(&rq->xdp_ring, skb))) {
164 dev_kfree_skb_any(skb);
165 return NET_RX_DROP;
166 }
167
168 return NET_RX_SUCCESS;
169 }
170
171 static int veth_forward_skb(struct net_device *dev, struct sk_buff *skb,
172 struct veth_rq *rq, bool xdp)
173 {
174 return __dev_forward_skb(dev, skb) ?: xdp ?
175 veth_xdp_rx(rq, skb) :
176 netif_rx(skb);
177 }
178
179 static netdev_tx_t veth_xmit(struct sk_buff *skb, struct net_device *dev)
180 {
181 struct veth_priv *rcv_priv, *priv = netdev_priv(dev);
182 struct veth_rq *rq = NULL;
183 struct net_device *rcv;
184 int length = skb->len;
185 bool rcv_xdp = false;
186 int rxq;
187
188 rcu_read_lock();
189 rcv = rcu_dereference(priv->peer);
190 if (unlikely(!rcv)) {
191 kfree_skb(skb);
192 goto drop;
193 }
194
195 rcv_priv = netdev_priv(rcv);
196 rxq = skb_get_queue_mapping(skb);
197 if (rxq < rcv->real_num_rx_queues) {
198 rq = &rcv_priv->rq[rxq];
199 rcv_xdp = rcu_access_pointer(rq->xdp_prog);
200 if (rcv_xdp)
201 skb_record_rx_queue(skb, rxq);
202 }
203
204 if (likely(veth_forward_skb(rcv, skb, rq, rcv_xdp) == NET_RX_SUCCESS)) {
205 struct pcpu_vstats *stats = this_cpu_ptr(dev->vstats);
206
207 u64_stats_update_begin(&stats->syncp);
208 stats->bytes += length;
209 stats->packets++;
210 u64_stats_update_end(&stats->syncp);
211 } else {
212 drop:
213 atomic64_inc(&priv->dropped);
214 }
215
216 if (rcv_xdp)
217 __veth_xdp_flush(rq);
218
219 rcu_read_unlock();
220
221 return NETDEV_TX_OK;
222 }
223
224 static u64 veth_stats_one(struct pcpu_vstats *result, struct net_device *dev)
225 {
226 struct veth_priv *priv = netdev_priv(dev);
227 int cpu;
228
229 result->packets = 0;
230 result->bytes = 0;
231 for_each_possible_cpu(cpu) {
232 struct pcpu_vstats *stats = per_cpu_ptr(dev->vstats, cpu);
233 u64 packets, bytes;
234 unsigned int start;
235
236 do {
237 start = u64_stats_fetch_begin_irq(&stats->syncp);
238 packets = stats->packets;
239 bytes = stats->bytes;
240 } while (u64_stats_fetch_retry_irq(&stats->syncp, start));
241 result->packets += packets;
242 result->bytes += bytes;
243 }
244 return atomic64_read(&priv->dropped);
245 }
246
247 static void veth_get_stats64(struct net_device *dev,
248 struct rtnl_link_stats64 *tot)
249 {
250 struct veth_priv *priv = netdev_priv(dev);
251 struct net_device *peer;
252 struct pcpu_vstats one;
253
254 tot->tx_dropped = veth_stats_one(&one, dev);
255 tot->tx_bytes = one.bytes;
256 tot->tx_packets = one.packets;
257
258 rcu_read_lock();
259 peer = rcu_dereference(priv->peer);
260 if (peer) {
261 tot->rx_dropped = veth_stats_one(&one, peer);
262 tot->rx_bytes = one.bytes;
263 tot->rx_packets = one.packets;
264 }
265 rcu_read_unlock();
266 }
267
268 /* fake multicast ability */
269 static void veth_set_multicast_list(struct net_device *dev)
270 {
271 }
272
273 static struct sk_buff *veth_build_skb(void *head, int headroom, int len,
274 int buflen)
275 {
276 struct sk_buff *skb;
277
278 if (!buflen) {
279 buflen = SKB_DATA_ALIGN(headroom + len) +
280 SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
281 }
282 skb = build_skb(head, buflen);
283 if (!skb)
284 return NULL;
285
286 skb_reserve(skb, headroom);
287 skb_put(skb, len);
288
289 return skb;
290 }
291
292 static int veth_select_rxq(struct net_device *dev)
293 {
294 return smp_processor_id() % dev->real_num_rx_queues;
295 }
296
297 static int veth_xdp_xmit(struct net_device *dev, int n,
298 struct xdp_frame **frames, u32 flags)
299 {
300 struct veth_priv *rcv_priv, *priv = netdev_priv(dev);
301 struct net_device *rcv;
302 unsigned int max_len;
303 struct veth_rq *rq;
304 int i, drops = 0;
305
306 if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK))
307 return -EINVAL;
308
309 rcv = rcu_dereference(priv->peer);
310 if (unlikely(!rcv))
311 return -ENXIO;
312
313 rcv_priv = netdev_priv(rcv);
314 rq = &rcv_priv->rq[veth_select_rxq(rcv)];
315 /* Non-NULL xdp_prog ensures that xdp_ring is initialized on receive
316 * side. This means an XDP program is loaded on the peer and the peer
317 * device is up.
318 */
319 if (!rcu_access_pointer(rq->xdp_prog))
320 return -ENXIO;
321
322 max_len = rcv->mtu + rcv->hard_header_len + VLAN_HLEN;
323
324 spin_lock(&rq->xdp_ring.producer_lock);
325 for (i = 0; i < n; i++) {
326 struct xdp_frame *frame = frames[i];
327 void *ptr = veth_xdp_to_ptr(frame);
328
329 if (unlikely(frame->len > max_len ||
330 __ptr_ring_produce(&rq->xdp_ring, ptr))) {
331 xdp_return_frame_rx_napi(frame);
332 drops++;
333 }
334 }
335 spin_unlock(&rq->xdp_ring.producer_lock);
336
337 if (flags & XDP_XMIT_FLUSH)
338 __veth_xdp_flush(rq);
339
340 return n - drops;
341 }
342
343 static void veth_xdp_flush(struct net_device *dev)
344 {
345 struct veth_priv *rcv_priv, *priv = netdev_priv(dev);
346 struct net_device *rcv;
347 struct veth_rq *rq;
348
349 rcu_read_lock();
350 rcv = rcu_dereference(priv->peer);
351 if (unlikely(!rcv))
352 goto out;
353
354 rcv_priv = netdev_priv(rcv);
355 rq = &rcv_priv->rq[veth_select_rxq(rcv)];
356 /* xdp_ring is initialized on receive side? */
357 if (unlikely(!rcu_access_pointer(rq->xdp_prog)))
358 goto out;
359
360 __veth_xdp_flush(rq);
361 out:
362 rcu_read_unlock();
363 }
364
365 static int veth_xdp_tx(struct net_device *dev, struct xdp_buff *xdp)
366 {
367 struct xdp_frame *frame = convert_to_xdp_frame(xdp);
368
369 if (unlikely(!frame))
370 return -EOVERFLOW;
371
372 return veth_xdp_xmit(dev, 1, &frame, 0);
373 }
374
375 static struct sk_buff *veth_xdp_rcv_one(struct veth_rq *rq,
376 struct xdp_frame *frame,
377 unsigned int *xdp_xmit)
378 {
379 void *hard_start = frame->data - frame->headroom;
380 int len = frame->len, delta = 0;
381 struct xdp_frame orig_frame;
382 struct bpf_prog *xdp_prog;
383 unsigned int headroom;
384 struct sk_buff *skb;
385
386 /* bpf_xdp_adjust_head() assures BPF cannot access xdp_frame area */
387 hard_start -= sizeof(struct xdp_frame);
388
389 rcu_read_lock();
390 xdp_prog = rcu_dereference(rq->xdp_prog);
391 if (likely(xdp_prog)) {
392 struct xdp_buff xdp;
393 u32 act;
394
395 xdp.data_hard_start = hard_start;
396 xdp.data = frame->data;
397 xdp.data_end = frame->data + frame->len;
398 xdp.data_meta = frame->data - frame->metasize;
399 xdp.rxq = &rq->xdp_rxq;
400
401 act = bpf_prog_run_xdp(xdp_prog, &xdp);
402
403 switch (act) {
404 case XDP_PASS:
405 delta = frame->data - xdp.data;
406 len = xdp.data_end - xdp.data;
407 break;
408 case XDP_TX:
409 orig_frame = *frame;
410 xdp.rxq->mem = frame->mem;
411 if (unlikely(veth_xdp_tx(rq->dev, &xdp) < 0)) {
412 trace_xdp_exception(rq->dev, xdp_prog, act);
413 frame = &orig_frame;
414 goto err_xdp;
415 }
416 *xdp_xmit |= VETH_XDP_TX;
417 rcu_read_unlock();
418 goto xdp_xmit;
419 case XDP_REDIRECT:
420 orig_frame = *frame;
421 xdp.rxq->mem = frame->mem;
422 if (xdp_do_redirect(rq->dev, &xdp, xdp_prog)) {
423 frame = &orig_frame;
424 goto err_xdp;
425 }
426 *xdp_xmit |= VETH_XDP_REDIR;
427 rcu_read_unlock();
428 goto xdp_xmit;
429 default:
430 bpf_warn_invalid_xdp_action(act);
431 case XDP_ABORTED:
432 trace_xdp_exception(rq->dev, xdp_prog, act);
433 case XDP_DROP:
434 goto err_xdp;
435 }
436 }
437 rcu_read_unlock();
438
439 headroom = sizeof(struct xdp_frame) + frame->headroom - delta;
440 skb = veth_build_skb(hard_start, headroom, len, 0);
441 if (!skb) {
442 xdp_return_frame(frame);
443 goto err;
444 }
445
446 xdp_scrub_frame(frame);
447 skb->protocol = eth_type_trans(skb, rq->dev);
448 err:
449 return skb;
450 err_xdp:
451 rcu_read_unlock();
452 xdp_return_frame(frame);
453 xdp_xmit:
454 return NULL;
455 }
456
457 static struct sk_buff *veth_xdp_rcv_skb(struct veth_rq *rq, struct sk_buff *skb,
458 unsigned int *xdp_xmit)
459 {
460 u32 pktlen, headroom, act, metalen;
461 void *orig_data, *orig_data_end;
462 struct bpf_prog *xdp_prog;
463 int mac_len, delta, off;
464 struct xdp_buff xdp;
465
466 skb_orphan(skb);
467
468 rcu_read_lock();
469 xdp_prog = rcu_dereference(rq->xdp_prog);
470 if (unlikely(!xdp_prog)) {
471 rcu_read_unlock();
472 goto out;
473 }
474
475 mac_len = skb->data - skb_mac_header(skb);
476 pktlen = skb->len + mac_len;
477 headroom = skb_headroom(skb) - mac_len;
478
479 if (skb_shared(skb) || skb_head_is_locked(skb) ||
480 skb_is_nonlinear(skb) || headroom < XDP_PACKET_HEADROOM) {
481 struct sk_buff *nskb;
482 int size, head_off;
483 void *head, *start;
484 struct page *page;
485
486 size = SKB_DATA_ALIGN(VETH_XDP_HEADROOM + pktlen) +
487 SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
488 if (size > PAGE_SIZE)
489 goto drop;
490
491 page = alloc_page(GFP_ATOMIC | __GFP_NOWARN);
492 if (!page)
493 goto drop;
494
495 head = page_address(page);
496 start = head + VETH_XDP_HEADROOM;
497 if (skb_copy_bits(skb, -mac_len, start, pktlen)) {
498 page_frag_free(head);
499 goto drop;
500 }
501
502 nskb = veth_build_skb(head,
503 VETH_XDP_HEADROOM + mac_len, skb->len,
504 PAGE_SIZE);
505 if (!nskb) {
506 page_frag_free(head);
507 goto drop;
508 }
509
510 skb_copy_header(nskb, skb);
511 head_off = skb_headroom(nskb) - skb_headroom(skb);
512 skb_headers_offset_update(nskb, head_off);
513 consume_skb(skb);
514 skb = nskb;
515 }
516
517 xdp.data_hard_start = skb->head;
518 xdp.data = skb_mac_header(skb);
519 xdp.data_end = xdp.data + pktlen;
520 xdp.data_meta = xdp.data;
521 xdp.rxq = &rq->xdp_rxq;
522 orig_data = xdp.data;
523 orig_data_end = xdp.data_end;
524
525 act = bpf_prog_run_xdp(xdp_prog, &xdp);
526
527 switch (act) {
528 case XDP_PASS:
529 break;
530 case XDP_TX:
531 get_page(virt_to_page(xdp.data));
532 consume_skb(skb);
533 xdp.rxq->mem = rq->xdp_mem;
534 if (unlikely(veth_xdp_tx(rq->dev, &xdp) < 0)) {
535 trace_xdp_exception(rq->dev, xdp_prog, act);
536 goto err_xdp;
537 }
538 *xdp_xmit |= VETH_XDP_TX;
539 rcu_read_unlock();
540 goto xdp_xmit;
541 case XDP_REDIRECT:
542 get_page(virt_to_page(xdp.data));
543 consume_skb(skb);
544 xdp.rxq->mem = rq->xdp_mem;
545 if (xdp_do_redirect(rq->dev, &xdp, xdp_prog))
546 goto err_xdp;
547 *xdp_xmit |= VETH_XDP_REDIR;
548 rcu_read_unlock();
549 goto xdp_xmit;
550 default:
551 bpf_warn_invalid_xdp_action(act);
552 case XDP_ABORTED:
553 trace_xdp_exception(rq->dev, xdp_prog, act);
554 case XDP_DROP:
555 goto drop;
556 }
557 rcu_read_unlock();
558
559 delta = orig_data - xdp.data;
560 off = mac_len + delta;
561 if (off > 0)
562 __skb_push(skb, off);
563 else if (off < 0)
564 __skb_pull(skb, -off);
565 skb->mac_header -= delta;
566 off = xdp.data_end - orig_data_end;
567 if (off != 0)
568 __skb_put(skb, off);
569 skb->protocol = eth_type_trans(skb, rq->dev);
570
571 metalen = xdp.data - xdp.data_meta;
572 if (metalen)
573 skb_metadata_set(skb, metalen);
574 out:
575 return skb;
576 drop:
577 rcu_read_unlock();
578 kfree_skb(skb);
579 return NULL;
580 err_xdp:
581 rcu_read_unlock();
582 page_frag_free(xdp.data);
583 xdp_xmit:
584 return NULL;
585 }
586
587 static int veth_xdp_rcv(struct veth_rq *rq, int budget, unsigned int *xdp_xmit)
588 {
589 int i, done = 0;
590
591 for (i = 0; i < budget; i++) {
592 void *ptr = __ptr_ring_consume(&rq->xdp_ring);
593 struct sk_buff *skb;
594
595 if (!ptr)
596 break;
597
598 if (veth_is_xdp_frame(ptr)) {
599 skb = veth_xdp_rcv_one(rq, veth_ptr_to_xdp(ptr),
600 xdp_xmit);
601 } else {
602 skb = veth_xdp_rcv_skb(rq, ptr, xdp_xmit);
603 }
604
605 if (skb)
606 napi_gro_receive(&rq->xdp_napi, skb);
607
608 done++;
609 }
610
611 return done;
612 }
613
614 static int veth_poll(struct napi_struct *napi, int budget)
615 {
616 struct veth_rq *rq =
617 container_of(napi, struct veth_rq, xdp_napi);
618 unsigned int xdp_xmit = 0;
619 int done;
620
621 xdp_set_return_frame_no_direct();
622 done = veth_xdp_rcv(rq, budget, &xdp_xmit);
623
624 if (done < budget && napi_complete_done(napi, done)) {
625 /* Write rx_notify_masked before reading ptr_ring */
626 smp_store_mb(rq->rx_notify_masked, false);
627 if (unlikely(!__ptr_ring_empty(&rq->xdp_ring))) {
628 rq->rx_notify_masked = true;
629 napi_schedule(&rq->xdp_napi);
630 }
631 }
632
633 if (xdp_xmit & VETH_XDP_TX)
634 veth_xdp_flush(rq->dev);
635 if (xdp_xmit & VETH_XDP_REDIR)
636 xdp_do_flush_map();
637 xdp_clear_return_frame_no_direct();
638
639 return done;
640 }
641
642 static int veth_napi_add(struct net_device *dev)
643 {
644 struct veth_priv *priv = netdev_priv(dev);
645 int err, i;
646
647 for (i = 0; i < dev->real_num_rx_queues; i++) {
648 struct veth_rq *rq = &priv->rq[i];
649
650 err = ptr_ring_init(&rq->xdp_ring, VETH_RING_SIZE, GFP_KERNEL);
651 if (err)
652 goto err_xdp_ring;
653 }
654
655 for (i = 0; i < dev->real_num_rx_queues; i++) {
656 struct veth_rq *rq = &priv->rq[i];
657
658 netif_napi_add(dev, &rq->xdp_napi, veth_poll, NAPI_POLL_WEIGHT);
659 napi_enable(&rq->xdp_napi);
660 }
661
662 return 0;
663 err_xdp_ring:
664 for (i--; i >= 0; i--)
665 ptr_ring_cleanup(&priv->rq[i].xdp_ring, veth_ptr_free);
666
667 return err;
668 }
669
670 static void veth_napi_del(struct net_device *dev)
671 {
672 struct veth_priv *priv = netdev_priv(dev);
673 int i;
674
675 for (i = 0; i < dev->real_num_rx_queues; i++) {
676 struct veth_rq *rq = &priv->rq[i];
677
678 napi_disable(&rq->xdp_napi);
679 napi_hash_del(&rq->xdp_napi);
680 }
681 synchronize_net();
682
683 for (i = 0; i < dev->real_num_rx_queues; i++) {
684 struct veth_rq *rq = &priv->rq[i];
685
686 netif_napi_del(&rq->xdp_napi);
687 rq->rx_notify_masked = false;
688 ptr_ring_cleanup(&rq->xdp_ring, veth_ptr_free);
689 }
690 }
691
692 static int veth_enable_xdp(struct net_device *dev)
693 {
694 struct veth_priv *priv = netdev_priv(dev);
695 int err, i;
696
697 if (!xdp_rxq_info_is_reg(&priv->rq[0].xdp_rxq)) {
698 for (i = 0; i < dev->real_num_rx_queues; i++) {
699 struct veth_rq *rq = &priv->rq[i];
700
701 err = xdp_rxq_info_reg(&rq->xdp_rxq, dev, i);
702 if (err < 0)
703 goto err_rxq_reg;
704
705 err = xdp_rxq_info_reg_mem_model(&rq->xdp_rxq,
706 MEM_TYPE_PAGE_SHARED,
707 NULL);
708 if (err < 0)
709 goto err_reg_mem;
710
711 /* Save original mem info as it can be overwritten */
712 rq->xdp_mem = rq->xdp_rxq.mem;
713 }
714
715 err = veth_napi_add(dev);
716 if (err)
717 goto err_rxq_reg;
718 }
719
720 for (i = 0; i < dev->real_num_rx_queues; i++)
721 rcu_assign_pointer(priv->rq[i].xdp_prog, priv->_xdp_prog);
722
723 return 0;
724 err_reg_mem:
725 xdp_rxq_info_unreg(&priv->rq[i].xdp_rxq);
726 err_rxq_reg:
727 for (i--; i >= 0; i--)
728 xdp_rxq_info_unreg(&priv->rq[i].xdp_rxq);
729
730 return err;
731 }
732
733 static void veth_disable_xdp(struct net_device *dev)
734 {
735 struct veth_priv *priv = netdev_priv(dev);
736 int i;
737
738 for (i = 0; i < dev->real_num_rx_queues; i++)
739 rcu_assign_pointer(priv->rq[i].xdp_prog, NULL);
740 veth_napi_del(dev);
741 for (i = 0; i < dev->real_num_rx_queues; i++) {
742 struct veth_rq *rq = &priv->rq[i];
743
744 rq->xdp_rxq.mem = rq->xdp_mem;
745 xdp_rxq_info_unreg(&rq->xdp_rxq);
746 }
747 }
748
749 static int veth_open(struct net_device *dev)
750 {
751 struct veth_priv *priv = netdev_priv(dev);
752 struct net_device *peer = rtnl_dereference(priv->peer);
753 int err;
754
755 if (!peer)
756 return -ENOTCONN;
757
758 if (priv->_xdp_prog) {
759 err = veth_enable_xdp(dev);
760 if (err)
761 return err;
762 }
763
764 if (peer->flags & IFF_UP) {
765 netif_carrier_on(dev);
766 netif_carrier_on(peer);
767 }
768
769 return 0;
770 }
771
772 static int veth_close(struct net_device *dev)
773 {
774 struct veth_priv *priv = netdev_priv(dev);
775 struct net_device *peer = rtnl_dereference(priv->peer);
776
777 netif_carrier_off(dev);
778 if (peer)
779 netif_carrier_off(peer);
780
781 if (priv->_xdp_prog)
782 veth_disable_xdp(dev);
783
784 return 0;
785 }
786
787 static int is_valid_veth_mtu(int mtu)
788 {
789 return mtu >= ETH_MIN_MTU && mtu <= ETH_MAX_MTU;
790 }
791
792 static int veth_alloc_queues(struct net_device *dev)
793 {
794 struct veth_priv *priv = netdev_priv(dev);
795 int i;
796
797 priv->rq = kcalloc(dev->num_rx_queues, sizeof(*priv->rq), GFP_KERNEL);
798 if (!priv->rq)
799 return -ENOMEM;
800
801 for (i = 0; i < dev->num_rx_queues; i++)
802 priv->rq[i].dev = dev;
803
804 return 0;
805 }
806
807 static void veth_free_queues(struct net_device *dev)
808 {
809 struct veth_priv *priv = netdev_priv(dev);
810
811 kfree(priv->rq);
812 }
813
814 static int veth_dev_init(struct net_device *dev)
815 {
816 int err;
817
818 dev->vstats = netdev_alloc_pcpu_stats(struct pcpu_vstats);
819 if (!dev->vstats)
820 return -ENOMEM;
821
822 err = veth_alloc_queues(dev);
823 if (err) {
824 free_percpu(dev->vstats);
825 return err;
826 }
827
828 return 0;
829 }
830
831 static void veth_dev_free(struct net_device *dev)
832 {
833 veth_free_queues(dev);
834 free_percpu(dev->vstats);
835 }
836
837 #ifdef CONFIG_NET_POLL_CONTROLLER
838 static void veth_poll_controller(struct net_device *dev)
839 {
840 /* veth only receives frames when its peer sends one
841 * Since it has nothing to do with disabling irqs, we are guaranteed
842 * never to have pending data when we poll for it so
843 * there is nothing to do here.
844 *
845 * We need this though so netpoll recognizes us as an interface that
846 * supports polling, which enables bridge devices in virt setups to
847 * still use netconsole
848 */
849 }
850 #endif /* CONFIG_NET_POLL_CONTROLLER */
851
852 static int veth_get_iflink(const struct net_device *dev)
853 {
854 struct veth_priv *priv = netdev_priv(dev);
855 struct net_device *peer;
856 int iflink;
857
858 rcu_read_lock();
859 peer = rcu_dereference(priv->peer);
860 iflink = peer ? peer->ifindex : 0;
861 rcu_read_unlock();
862
863 return iflink;
864 }
865
866 static netdev_features_t veth_fix_features(struct net_device *dev,
867 netdev_features_t features)
868 {
869 struct veth_priv *priv = netdev_priv(dev);
870 struct net_device *peer;
871
872 peer = rtnl_dereference(priv->peer);
873 if (peer) {
874 struct veth_priv *peer_priv = netdev_priv(peer);
875
876 if (peer_priv->_xdp_prog)
877 features &= ~NETIF_F_GSO_SOFTWARE;
878 }
879
880 return features;
881 }
882
883 static void veth_set_rx_headroom(struct net_device *dev, int new_hr)
884 {
885 struct veth_priv *peer_priv, *priv = netdev_priv(dev);
886 struct net_device *peer;
887
888 if (new_hr < 0)
889 new_hr = 0;
890
891 rcu_read_lock();
892 peer = rcu_dereference(priv->peer);
893 if (unlikely(!peer))
894 goto out;
895
896 peer_priv = netdev_priv(peer);
897 priv->requested_headroom = new_hr;
898 new_hr = max(priv->requested_headroom, peer_priv->requested_headroom);
899 dev->needed_headroom = new_hr;
900 peer->needed_headroom = new_hr;
901
902 out:
903 rcu_read_unlock();
904 }
905
906 static int veth_xdp_set(struct net_device *dev, struct bpf_prog *prog,
907 struct netlink_ext_ack *extack)
908 {
909 struct veth_priv *priv = netdev_priv(dev);
910 struct bpf_prog *old_prog;
911 struct net_device *peer;
912 unsigned int max_mtu;
913 int err;
914
915 old_prog = priv->_xdp_prog;
916 priv->_xdp_prog = prog;
917 peer = rtnl_dereference(priv->peer);
918
919 if (prog) {
920 if (!peer) {
921 NL_SET_ERR_MSG_MOD(extack, "Cannot set XDP when peer is detached");
922 err = -ENOTCONN;
923 goto err;
924 }
925
926 max_mtu = PAGE_SIZE - VETH_XDP_HEADROOM -
927 peer->hard_header_len -
928 SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
929 if (peer->mtu > max_mtu) {
930 NL_SET_ERR_MSG_MOD(extack, "Peer MTU is too large to set XDP");
931 err = -ERANGE;
932 goto err;
933 }
934
935 if (dev->real_num_rx_queues < peer->real_num_tx_queues) {
936 NL_SET_ERR_MSG_MOD(extack, "XDP expects number of rx queues not less than peer tx queues");
937 err = -ENOSPC;
938 goto err;
939 }
940
941 if (dev->flags & IFF_UP) {
942 err = veth_enable_xdp(dev);
943 if (err) {
944 NL_SET_ERR_MSG_MOD(extack, "Setup for XDP failed");
945 goto err;
946 }
947 }
948
949 if (!old_prog) {
950 peer->hw_features &= ~NETIF_F_GSO_SOFTWARE;
951 peer->max_mtu = max_mtu;
952 }
953 }
954
955 if (old_prog) {
956 if (!prog) {
957 if (dev->flags & IFF_UP)
958 veth_disable_xdp(dev);
959
960 if (peer) {
961 peer->hw_features |= NETIF_F_GSO_SOFTWARE;
962 peer->max_mtu = ETH_MAX_MTU;
963 }
964 }
965 bpf_prog_put(old_prog);
966 }
967
968 if ((!!old_prog ^ !!prog) && peer)
969 netdev_update_features(peer);
970
971 return 0;
972 err:
973 priv->_xdp_prog = old_prog;
974
975 return err;
976 }
977
978 static u32 veth_xdp_query(struct net_device *dev)
979 {
980 struct veth_priv *priv = netdev_priv(dev);
981 const struct bpf_prog *xdp_prog;
982
983 xdp_prog = priv->_xdp_prog;
984 if (xdp_prog)
985 return xdp_prog->aux->id;
986
987 return 0;
988 }
989
990 static int veth_xdp(struct net_device *dev, struct netdev_bpf *xdp)
991 {
992 switch (xdp->command) {
993 case XDP_SETUP_PROG:
994 return veth_xdp_set(dev, xdp->prog, xdp->extack);
995 case XDP_QUERY_PROG:
996 xdp->prog_id = veth_xdp_query(dev);
997 return 0;
998 default:
999 return -EINVAL;
1000 }
1001 }
1002
1003 static const struct net_device_ops veth_netdev_ops = {
1004 .ndo_init = veth_dev_init,
1005 .ndo_open = veth_open,
1006 .ndo_stop = veth_close,
1007 .ndo_start_xmit = veth_xmit,
1008 .ndo_get_stats64 = veth_get_stats64,
1009 .ndo_set_rx_mode = veth_set_multicast_list,
1010 .ndo_set_mac_address = eth_mac_addr,
1011 #ifdef CONFIG_NET_POLL_CONTROLLER
1012 .ndo_poll_controller = veth_poll_controller,
1013 #endif
1014 .ndo_get_iflink = veth_get_iflink,
1015 .ndo_fix_features = veth_fix_features,
1016 .ndo_features_check = passthru_features_check,
1017 .ndo_set_rx_headroom = veth_set_rx_headroom,
1018 .ndo_bpf = veth_xdp,
1019 .ndo_xdp_xmit = veth_xdp_xmit,
1020 };
1021
1022 #define VETH_FEATURES (NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HW_CSUM | \
1023 NETIF_F_RXCSUM | NETIF_F_SCTP_CRC | NETIF_F_HIGHDMA | \
1024 NETIF_F_GSO_SOFTWARE | NETIF_F_GSO_ENCAP_ALL | \
1025 NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_CTAG_RX | \
1026 NETIF_F_HW_VLAN_STAG_TX | NETIF_F_HW_VLAN_STAG_RX )
1027
1028 static void veth_setup(struct net_device *dev)
1029 {
1030 ether_setup(dev);
1031
1032 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1033 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1034 dev->priv_flags |= IFF_NO_QUEUE;
1035 dev->priv_flags |= IFF_PHONY_HEADROOM;
1036
1037 dev->netdev_ops = &veth_netdev_ops;
1038 dev->ethtool_ops = &veth_ethtool_ops;
1039 dev->features |= NETIF_F_LLTX;
1040 dev->features |= VETH_FEATURES;
1041 dev->vlan_features = dev->features &
1042 ~(NETIF_F_HW_VLAN_CTAG_TX |
1043 NETIF_F_HW_VLAN_STAG_TX |
1044 NETIF_F_HW_VLAN_CTAG_RX |
1045 NETIF_F_HW_VLAN_STAG_RX);
1046 dev->needs_free_netdev = true;
1047 dev->priv_destructor = veth_dev_free;
1048 dev->max_mtu = ETH_MAX_MTU;
1049
1050 dev->hw_features = VETH_FEATURES;
1051 dev->hw_enc_features = VETH_FEATURES;
1052 dev->mpls_features = NETIF_F_HW_CSUM | NETIF_F_GSO_SOFTWARE;
1053 }
1054
1055 /*
1056 * netlink interface
1057 */
1058
1059 static int veth_validate(struct nlattr *tb[], struct nlattr *data[],
1060 struct netlink_ext_ack *extack)
1061 {
1062 if (tb[IFLA_ADDRESS]) {
1063 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1064 return -EINVAL;
1065 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1066 return -EADDRNOTAVAIL;
1067 }
1068 if (tb[IFLA_MTU]) {
1069 if (!is_valid_veth_mtu(nla_get_u32(tb[IFLA_MTU])))
1070 return -EINVAL;
1071 }
1072 return 0;
1073 }
1074
1075 static struct rtnl_link_ops veth_link_ops;
1076
1077 static int veth_newlink(struct net *src_net, struct net_device *dev,
1078 struct nlattr *tb[], struct nlattr *data[],
1079 struct netlink_ext_ack *extack)
1080 {
1081 int err;
1082 struct net_device *peer;
1083 struct veth_priv *priv;
1084 char ifname[IFNAMSIZ];
1085 struct nlattr *peer_tb[IFLA_MAX + 1], **tbp;
1086 unsigned char name_assign_type;
1087 struct ifinfomsg *ifmp;
1088 struct net *net;
1089
1090 /*
1091 * create and register peer first
1092 */
1093 if (data != NULL && data[VETH_INFO_PEER] != NULL) {
1094 struct nlattr *nla_peer;
1095
1096 nla_peer = data[VETH_INFO_PEER];
1097 ifmp = nla_data(nla_peer);
1098 err = rtnl_nla_parse_ifla(peer_tb,
1099 nla_data(nla_peer) + sizeof(struct ifinfomsg),
1100 nla_len(nla_peer) - sizeof(struct ifinfomsg),
1101 NULL);
1102 if (err < 0)
1103 return err;
1104
1105 err = veth_validate(peer_tb, NULL, extack);
1106 if (err < 0)
1107 return err;
1108
1109 tbp = peer_tb;
1110 } else {
1111 ifmp = NULL;
1112 tbp = tb;
1113 }
1114
1115 if (ifmp && tbp[IFLA_IFNAME]) {
1116 nla_strlcpy(ifname, tbp[IFLA_IFNAME], IFNAMSIZ);
1117 name_assign_type = NET_NAME_USER;
1118 } else {
1119 snprintf(ifname, IFNAMSIZ, DRV_NAME "%%d");
1120 name_assign_type = NET_NAME_ENUM;
1121 }
1122
1123 net = rtnl_link_get_net(src_net, tbp);
1124 if (IS_ERR(net))
1125 return PTR_ERR(net);
1126
1127 peer = rtnl_create_link(net, ifname, name_assign_type,
1128 &veth_link_ops, tbp);
1129 if (IS_ERR(peer)) {
1130 put_net(net);
1131 return PTR_ERR(peer);
1132 }
1133
1134 if (!ifmp || !tbp[IFLA_ADDRESS])
1135 eth_hw_addr_random(peer);
1136
1137 if (ifmp && (dev->ifindex != 0))
1138 peer->ifindex = ifmp->ifi_index;
1139
1140 peer->gso_max_size = dev->gso_max_size;
1141 peer->gso_max_segs = dev->gso_max_segs;
1142
1143 err = register_netdevice(peer);
1144 put_net(net);
1145 net = NULL;
1146 if (err < 0)
1147 goto err_register_peer;
1148
1149 netif_carrier_off(peer);
1150
1151 err = rtnl_configure_link(peer, ifmp);
1152 if (err < 0)
1153 goto err_configure_peer;
1154
1155 /*
1156 * register dev last
1157 *
1158 * note, that since we've registered new device the dev's name
1159 * should be re-allocated
1160 */
1161
1162 if (tb[IFLA_ADDRESS] == NULL)
1163 eth_hw_addr_random(dev);
1164
1165 if (tb[IFLA_IFNAME])
1166 nla_strlcpy(dev->name, tb[IFLA_IFNAME], IFNAMSIZ);
1167 else
1168 snprintf(dev->name, IFNAMSIZ, DRV_NAME "%%d");
1169
1170 err = register_netdevice(dev);
1171 if (err < 0)
1172 goto err_register_dev;
1173
1174 netif_carrier_off(dev);
1175
1176 /*
1177 * tie the deviced together
1178 */
1179
1180 priv = netdev_priv(dev);
1181 rcu_assign_pointer(priv->peer, peer);
1182
1183 priv = netdev_priv(peer);
1184 rcu_assign_pointer(priv->peer, dev);
1185
1186 return 0;
1187
1188 err_register_dev:
1189 /* nothing to do */
1190 err_configure_peer:
1191 unregister_netdevice(peer);
1192 return err;
1193
1194 err_register_peer:
1195 free_netdev(peer);
1196 return err;
1197 }
1198
1199 static void veth_dellink(struct net_device *dev, struct list_head *head)
1200 {
1201 struct veth_priv *priv;
1202 struct net_device *peer;
1203
1204 priv = netdev_priv(dev);
1205 peer = rtnl_dereference(priv->peer);
1206
1207 /* Note : dellink() is called from default_device_exit_batch(),
1208 * before a rcu_synchronize() point. The devices are guaranteed
1209 * not being freed before one RCU grace period.
1210 */
1211 RCU_INIT_POINTER(priv->peer, NULL);
1212 unregister_netdevice_queue(dev, head);
1213
1214 if (peer) {
1215 priv = netdev_priv(peer);
1216 RCU_INIT_POINTER(priv->peer, NULL);
1217 unregister_netdevice_queue(peer, head);
1218 }
1219 }
1220
1221 static const struct nla_policy veth_policy[VETH_INFO_MAX + 1] = {
1222 [VETH_INFO_PEER] = { .len = sizeof(struct ifinfomsg) },
1223 };
1224
1225 static struct net *veth_get_link_net(const struct net_device *dev)
1226 {
1227 struct veth_priv *priv = netdev_priv(dev);
1228 struct net_device *peer = rtnl_dereference(priv->peer);
1229
1230 return peer ? dev_net(peer) : dev_net(dev);
1231 }
1232
1233 static struct rtnl_link_ops veth_link_ops = {
1234 .kind = DRV_NAME,
1235 .priv_size = sizeof(struct veth_priv),
1236 .setup = veth_setup,
1237 .validate = veth_validate,
1238 .newlink = veth_newlink,
1239 .dellink = veth_dellink,
1240 .policy = veth_policy,
1241 .maxtype = VETH_INFO_MAX,
1242 .get_link_net = veth_get_link_net,
1243 };
1244
1245 /*
1246 * init/fini
1247 */
1248
1249 static __init int veth_init(void)
1250 {
1251 return rtnl_link_register(&veth_link_ops);
1252 }
1253
1254 static __exit void veth_exit(void)
1255 {
1256 rtnl_link_unregister(&veth_link_ops);
1257 }
1258
1259 module_init(veth_init);
1260 module_exit(veth_exit);
1261
1262 MODULE_DESCRIPTION("Virtual Ethernet Tunnel");
1263 MODULE_LICENSE("GPL v2");
1264 MODULE_ALIAS_RTNL_LINK(DRV_NAME);
Linux with added FPC-III support