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Merge tag 'for-linus-20190706' of git://git.kernel.dk/linux-block
[linux/fpc-iii.git] / drivers / net / veth.c
blob52110e54e621fdd45ebab5560949f55c494053f6
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * drivers/net/veth.c
4 *
5 * Copyright (C) 2007 OpenVZ http://openvz.org, SWsoft Inc
6 *
7 * Author: Pavel Emelianov <xemul@openvz.org>
8 * Ethtool interface from: Eric W. Biederman <ebiederm@xmission.com>
9 *
10 */
11
12 #include <linux/netdevice.h>
13 #include <linux/slab.h>
14 #include <linux/ethtool.h>
15 #include <linux/etherdevice.h>
16 #include <linux/u64_stats_sync.h>
17
18 #include <net/rtnetlink.h>
19 #include <net/dst.h>
20 #include <net/xfrm.h>
21 #include <net/xdp.h>
22 #include <linux/veth.h>
23 #include <linux/module.h>
24 #include <linux/bpf.h>
25 #include <linux/filter.h>
26 #include <linux/ptr_ring.h>
27 #include <linux/bpf_trace.h>
28 #include <linux/net_tstamp.h>
29
30 #define DRV_NAME "veth"
31 #define DRV_VERSION "1.0"
32
33 #define VETH_XDP_FLAG BIT(0)
34 #define VETH_RING_SIZE 256
35 #define VETH_XDP_HEADROOM (XDP_PACKET_HEADROOM + NET_IP_ALIGN)
36
37 /* Separating two types of XDP xmit */
38 #define VETH_XDP_TX BIT(0)
39 #define VETH_XDP_REDIR BIT(1)
40
41 struct veth_rq_stats {
42 u64 xdp_packets;
43 u64 xdp_bytes;
44 u64 xdp_drops;
45 struct u64_stats_sync syncp;
46 };
47
48 struct veth_rq {
49 struct napi_struct xdp_napi;
50 struct net_device *dev;
51 struct bpf_prog __rcu *xdp_prog;
52 struct xdp_mem_info xdp_mem;
53 struct veth_rq_stats stats;
54 bool rx_notify_masked;
55 struct ptr_ring xdp_ring;
56 struct xdp_rxq_info xdp_rxq;
57 };
58
59 struct veth_priv {
60 struct net_device __rcu *peer;
61 atomic64_t dropped;
62 struct bpf_prog *_xdp_prog;
63 struct veth_rq *rq;
64 unsigned int requested_headroom;
65 };
66
67 /*
68 * ethtool interface
69 */
70
71 struct veth_q_stat_desc {
72 char desc[ETH_GSTRING_LEN];
73 size_t offset;
74 };
75
76 #define VETH_RQ_STAT(m) offsetof(struct veth_rq_stats, m)
77
78 static const struct veth_q_stat_desc veth_rq_stats_desc[] = {
79 { "xdp_packets", VETH_RQ_STAT(xdp_packets) },
80 { "xdp_bytes", VETH_RQ_STAT(xdp_bytes) },
81 { "xdp_drops", VETH_RQ_STAT(xdp_drops) },
82 };
83
84 #define VETH_RQ_STATS_LEN ARRAY_SIZE(veth_rq_stats_desc)
85
86 static struct {
87 const char string[ETH_GSTRING_LEN];
88 } ethtool_stats_keys[] = {
89 { "peer_ifindex" },
90 };
91
92 static int veth_get_link_ksettings(struct net_device *dev,
93 struct ethtool_link_ksettings *cmd)
94 {
95 cmd->base.speed = SPEED_10000;
96 cmd->base.duplex = DUPLEX_FULL;
97 cmd->base.port = PORT_TP;
98 cmd->base.autoneg = AUTONEG_DISABLE;
99 return 0;
100 }
101
102 static void veth_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
103 {
104 strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
105 strlcpy(info->version, DRV_VERSION, sizeof(info->version));
106 }
107
108 static void veth_get_strings(struct net_device *dev, u32 stringset, u8 *buf)
109 {
110 char *p = (char *)buf;
111 int i, j;
112
113 switch(stringset) {
114 case ETH_SS_STATS:
115 memcpy(p, &ethtool_stats_keys, sizeof(ethtool_stats_keys));
116 p += sizeof(ethtool_stats_keys);
117 for (i = 0; i < dev->real_num_rx_queues; i++) {
118 for (j = 0; j < VETH_RQ_STATS_LEN; j++) {
119 snprintf(p, ETH_GSTRING_LEN,
120 "rx_queue_%u_%.11s",
121 i, veth_rq_stats_desc[j].desc);
122 p += ETH_GSTRING_LEN;
123 }
124 }
125 break;
126 }
127 }
128
129 static int veth_get_sset_count(struct net_device *dev, int sset)
130 {
131 switch (sset) {
132 case ETH_SS_STATS:
133 return ARRAY_SIZE(ethtool_stats_keys) +
134 VETH_RQ_STATS_LEN * dev->real_num_rx_queues;
135 default:
136 return -EOPNOTSUPP;
137 }
138 }
139
140 static void veth_get_ethtool_stats(struct net_device *dev,
141 struct ethtool_stats *stats, u64 *data)
142 {
143 struct veth_priv *priv = netdev_priv(dev);
144 struct net_device *peer = rtnl_dereference(priv->peer);
145 int i, j, idx;
146
147 data[0] = peer ? peer->ifindex : 0;
148 idx = 1;
149 for (i = 0; i < dev->real_num_rx_queues; i++) {
150 const struct veth_rq_stats *rq_stats = &priv->rq[i].stats;
151 const void *stats_base = (void *)rq_stats;
152 unsigned int start;
153 size_t offset;
154
155 do {
156 start = u64_stats_fetch_begin_irq(&rq_stats->syncp);
157 for (j = 0; j < VETH_RQ_STATS_LEN; j++) {
158 offset = veth_rq_stats_desc[j].offset;
159 data[idx + j] = *(u64 *)(stats_base + offset);
160 }
161 } while (u64_stats_fetch_retry_irq(&rq_stats->syncp, start));
162 idx += VETH_RQ_STATS_LEN;
163 }
164 }
165
166 static const struct ethtool_ops veth_ethtool_ops = {
167 .get_drvinfo = veth_get_drvinfo,
168 .get_link = ethtool_op_get_link,
169 .get_strings = veth_get_strings,
170 .get_sset_count = veth_get_sset_count,
171 .get_ethtool_stats = veth_get_ethtool_stats,
172 .get_link_ksettings = veth_get_link_ksettings,
173 .get_ts_info = ethtool_op_get_ts_info,
174 };
175
176 /* general routines */
177
178 static bool veth_is_xdp_frame(void *ptr)
179 {
180 return (unsigned long)ptr & VETH_XDP_FLAG;
181 }
182
183 static void *veth_ptr_to_xdp(void *ptr)
184 {
185 return (void *)((unsigned long)ptr & ~VETH_XDP_FLAG);
186 }
187
188 static void *veth_xdp_to_ptr(void *ptr)
189 {
190 return (void *)((unsigned long)ptr | VETH_XDP_FLAG);
191 }
192
193 static void veth_ptr_free(void *ptr)
194 {
195 if (veth_is_xdp_frame(ptr))
196 xdp_return_frame(veth_ptr_to_xdp(ptr));
197 else
198 kfree_skb(ptr);
199 }
200
201 static void __veth_xdp_flush(struct veth_rq *rq)
202 {
203 /* Write ptr_ring before reading rx_notify_masked */
204 smp_mb();
205 if (!rq->rx_notify_masked) {
206 rq->rx_notify_masked = true;
207 napi_schedule(&rq->xdp_napi);
208 }
209 }
210
211 static int veth_xdp_rx(struct veth_rq *rq, struct sk_buff *skb)
212 {
213 if (unlikely(ptr_ring_produce(&rq->xdp_ring, skb))) {
214 dev_kfree_skb_any(skb);
215 return NET_RX_DROP;
216 }
217
218 return NET_RX_SUCCESS;
219 }
220
221 static int veth_forward_skb(struct net_device *dev, struct sk_buff *skb,
222 struct veth_rq *rq, bool xdp)
223 {
224 return __dev_forward_skb(dev, skb) ?: xdp ?
225 veth_xdp_rx(rq, skb) :
226 netif_rx(skb);
227 }
228
229 static netdev_tx_t veth_xmit(struct sk_buff *skb, struct net_device *dev)
230 {
231 struct veth_priv *rcv_priv, *priv = netdev_priv(dev);
232 struct veth_rq *rq = NULL;
233 struct net_device *rcv;
234 int length = skb->len;
235 bool rcv_xdp = false;
236 int rxq;
237
238 rcu_read_lock();
239 rcv = rcu_dereference(priv->peer);
240 if (unlikely(!rcv)) {
241 kfree_skb(skb);
242 goto drop;
243 }
244
245 rcv_priv = netdev_priv(rcv);
246 rxq = skb_get_queue_mapping(skb);
247 if (rxq < rcv->real_num_rx_queues) {
248 rq = &rcv_priv->rq[rxq];
249 rcv_xdp = rcu_access_pointer(rq->xdp_prog);
250 if (rcv_xdp)
251 skb_record_rx_queue(skb, rxq);
252 }
253
254 skb_tx_timestamp(skb);
255 if (likely(veth_forward_skb(rcv, skb, rq, rcv_xdp) == NET_RX_SUCCESS)) {
256 if (!rcv_xdp) {
257 struct pcpu_lstats *stats = this_cpu_ptr(dev->lstats);
258
259 u64_stats_update_begin(&stats->syncp);
260 stats->bytes += length;
261 stats->packets++;
262 u64_stats_update_end(&stats->syncp);
263 }
264 } else {
265 drop:
266 atomic64_inc(&priv->dropped);
267 }
268
269 if (rcv_xdp)
270 __veth_xdp_flush(rq);
271
272 rcu_read_unlock();
273
274 return NETDEV_TX_OK;
275 }
276
277 static u64 veth_stats_tx(struct pcpu_lstats *result, struct net_device *dev)
278 {
279 struct veth_priv *priv = netdev_priv(dev);
280 int cpu;
281
282 result->packets = 0;
283 result->bytes = 0;
284 for_each_possible_cpu(cpu) {
285 struct pcpu_lstats *stats = per_cpu_ptr(dev->lstats, cpu);
286 u64 packets, bytes;
287 unsigned int start;
288
289 do {
290 start = u64_stats_fetch_begin_irq(&stats->syncp);
291 packets = stats->packets;
292 bytes = stats->bytes;
293 } while (u64_stats_fetch_retry_irq(&stats->syncp, start));
294 result->packets += packets;
295 result->bytes += bytes;
296 }
297 return atomic64_read(&priv->dropped);
298 }
299
300 static void veth_stats_rx(struct veth_rq_stats *result, struct net_device *dev)
301 {
302 struct veth_priv *priv = netdev_priv(dev);
303 int i;
304
305 result->xdp_packets = 0;
306 result->xdp_bytes = 0;
307 result->xdp_drops = 0;
308 for (i = 0; i < dev->num_rx_queues; i++) {
309 struct veth_rq_stats *stats = &priv->rq[i].stats;
310 u64 packets, bytes, drops;
311 unsigned int start;
312
313 do {
314 start = u64_stats_fetch_begin_irq(&stats->syncp);
315 packets = stats->xdp_packets;
316 bytes = stats->xdp_bytes;
317 drops = stats->xdp_drops;
318 } while (u64_stats_fetch_retry_irq(&stats->syncp, start));
319 result->xdp_packets += packets;
320 result->xdp_bytes += bytes;
321 result->xdp_drops += drops;
322 }
323 }
324
325 static void veth_get_stats64(struct net_device *dev,
326 struct rtnl_link_stats64 *tot)
327 {
328 struct veth_priv *priv = netdev_priv(dev);
329 struct net_device *peer;
330 struct veth_rq_stats rx;
331 struct pcpu_lstats tx;
332
333 tot->tx_dropped = veth_stats_tx(&tx, dev);
334 tot->tx_bytes = tx.bytes;
335 tot->tx_packets = tx.packets;
336
337 veth_stats_rx(&rx, dev);
338 tot->rx_dropped = rx.xdp_drops;
339 tot->rx_bytes = rx.xdp_bytes;
340 tot->rx_packets = rx.xdp_packets;
341
342 rcu_read_lock();
343 peer = rcu_dereference(priv->peer);
344 if (peer) {
345 tot->rx_dropped += veth_stats_tx(&tx, peer);
346 tot->rx_bytes += tx.bytes;
347 tot->rx_packets += tx.packets;
348
349 veth_stats_rx(&rx, peer);
350 tot->tx_bytes += rx.xdp_bytes;
351 tot->tx_packets += rx.xdp_packets;
352 }
353 rcu_read_unlock();
354 }
355
356 /* fake multicast ability */
357 static void veth_set_multicast_list(struct net_device *dev)
358 {
359 }
360
361 static struct sk_buff *veth_build_skb(void *head, int headroom, int len,
362 int buflen)
363 {
364 struct sk_buff *skb;
365
366 if (!buflen) {
367 buflen = SKB_DATA_ALIGN(headroom + len) +
368 SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
369 }
370 skb = build_skb(head, buflen);
371 if (!skb)
372 return NULL;
373
374 skb_reserve(skb, headroom);
375 skb_put(skb, len);
376
377 return skb;
378 }
379
380 static int veth_select_rxq(struct net_device *dev)
381 {
382 return smp_processor_id() % dev->real_num_rx_queues;
383 }
384
385 static int veth_xdp_xmit(struct net_device *dev, int n,
386 struct xdp_frame **frames, u32 flags)
387 {
388 struct veth_priv *rcv_priv, *priv = netdev_priv(dev);
389 struct net_device *rcv;
390 int i, ret, drops = n;
391 unsigned int max_len;
392 struct veth_rq *rq;
393
394 if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK)) {
395 ret = -EINVAL;
396 goto drop;
397 }
398
399 rcv = rcu_dereference(priv->peer);
400 if (unlikely(!rcv)) {
401 ret = -ENXIO;
402 goto drop;
403 }
404
405 rcv_priv = netdev_priv(rcv);
406 rq = &rcv_priv->rq[veth_select_rxq(rcv)];
407 /* Non-NULL xdp_prog ensures that xdp_ring is initialized on receive
408 * side. This means an XDP program is loaded on the peer and the peer
409 * device is up.
410 */
411 if (!rcu_access_pointer(rq->xdp_prog)) {
412 ret = -ENXIO;
413 goto drop;
414 }
415
416 drops = 0;
417 max_len = rcv->mtu + rcv->hard_header_len + VLAN_HLEN;
418
419 spin_lock(&rq->xdp_ring.producer_lock);
420 for (i = 0; i < n; i++) {
421 struct xdp_frame *frame = frames[i];
422 void *ptr = veth_xdp_to_ptr(frame);
423
424 if (unlikely(frame->len > max_len ||
425 __ptr_ring_produce(&rq->xdp_ring, ptr))) {
426 xdp_return_frame_rx_napi(frame);
427 drops++;
428 }
429 }
430 spin_unlock(&rq->xdp_ring.producer_lock);
431
432 if (flags & XDP_XMIT_FLUSH)
433 __veth_xdp_flush(rq);
434
435 if (likely(!drops))
436 return n;
437
438 ret = n - drops;
439 drop:
440 atomic64_add(drops, &priv->dropped);
441
442 return ret;
443 }
444
445 static void veth_xdp_flush(struct net_device *dev)
446 {
447 struct veth_priv *rcv_priv, *priv = netdev_priv(dev);
448 struct net_device *rcv;
449 struct veth_rq *rq;
450
451 rcu_read_lock();
452 rcv = rcu_dereference(priv->peer);
453 if (unlikely(!rcv))
454 goto out;
455
456 rcv_priv = netdev_priv(rcv);
457 rq = &rcv_priv->rq[veth_select_rxq(rcv)];
458 /* xdp_ring is initialized on receive side? */
459 if (unlikely(!rcu_access_pointer(rq->xdp_prog)))
460 goto out;
461
462 __veth_xdp_flush(rq);
463 out:
464 rcu_read_unlock();
465 }
466
467 static int veth_xdp_tx(struct net_device *dev, struct xdp_buff *xdp)
468 {
469 struct xdp_frame *frame = convert_to_xdp_frame(xdp);
470
471 if (unlikely(!frame))
472 return -EOVERFLOW;
473
474 return veth_xdp_xmit(dev, 1, &frame, 0);
475 }
476
477 static struct sk_buff *veth_xdp_rcv_one(struct veth_rq *rq,
478 struct xdp_frame *frame,
479 unsigned int *xdp_xmit)
480 {
481 void *hard_start = frame->data - frame->headroom;
482 void *head = hard_start - sizeof(struct xdp_frame);
483 int len = frame->len, delta = 0;
484 struct xdp_frame orig_frame;
485 struct bpf_prog *xdp_prog;
486 unsigned int headroom;
487 struct sk_buff *skb;
488
489 rcu_read_lock();
490 xdp_prog = rcu_dereference(rq->xdp_prog);
491 if (likely(xdp_prog)) {
492 struct xdp_buff xdp;
493 u32 act;
494
495 xdp.data_hard_start = hard_start;
496 xdp.data = frame->data;
497 xdp.data_end = frame->data + frame->len;
498 xdp.data_meta = frame->data - frame->metasize;
499 xdp.rxq = &rq->xdp_rxq;
500
501 act = bpf_prog_run_xdp(xdp_prog, &xdp);
502
503 switch (act) {
504 case XDP_PASS:
505 delta = frame->data - xdp.data;
506 len = xdp.data_end - xdp.data;
507 break;
508 case XDP_TX:
509 orig_frame = *frame;
510 xdp.data_hard_start = head;
511 xdp.rxq->mem = frame->mem;
512 if (unlikely(veth_xdp_tx(rq->dev, &xdp) < 0)) {
513 trace_xdp_exception(rq->dev, xdp_prog, act);
514 frame = &orig_frame;
515 goto err_xdp;
516 }
517 *xdp_xmit |= VETH_XDP_TX;
518 rcu_read_unlock();
519 goto xdp_xmit;
520 case XDP_REDIRECT:
521 orig_frame = *frame;
522 xdp.data_hard_start = head;
523 xdp.rxq->mem = frame->mem;
524 if (xdp_do_redirect(rq->dev, &xdp, xdp_prog)) {
525 frame = &orig_frame;
526 goto err_xdp;
527 }
528 *xdp_xmit |= VETH_XDP_REDIR;
529 rcu_read_unlock();
530 goto xdp_xmit;
531 default:
532 bpf_warn_invalid_xdp_action(act);
533 /* fall through */
534 case XDP_ABORTED:
535 trace_xdp_exception(rq->dev, xdp_prog, act);
536 /* fall through */
537 case XDP_DROP:
538 goto err_xdp;
539 }
540 }
541 rcu_read_unlock();
542
543 headroom = sizeof(struct xdp_frame) + frame->headroom - delta;
544 skb = veth_build_skb(head, headroom, len, 0);
545 if (!skb) {
546 xdp_return_frame(frame);
547 goto err;
548 }
549
550 xdp_scrub_frame(frame);
551 skb->protocol = eth_type_trans(skb, rq->dev);
552 err:
553 return skb;
554 err_xdp:
555 rcu_read_unlock();
556 xdp_return_frame(frame);
557 xdp_xmit:
558 return NULL;
559 }
560
561 static struct sk_buff *veth_xdp_rcv_skb(struct veth_rq *rq, struct sk_buff *skb,
562 unsigned int *xdp_xmit)
563 {
564 u32 pktlen, headroom, act, metalen;
565 void *orig_data, *orig_data_end;
566 struct bpf_prog *xdp_prog;
567 int mac_len, delta, off;
568 struct xdp_buff xdp;
569
570 skb_orphan(skb);
571
572 rcu_read_lock();
573 xdp_prog = rcu_dereference(rq->xdp_prog);
574 if (unlikely(!xdp_prog)) {
575 rcu_read_unlock();
576 goto out;
577 }
578
579 mac_len = skb->data - skb_mac_header(skb);
580 pktlen = skb->len + mac_len;
581 headroom = skb_headroom(skb) - mac_len;
582
583 if (skb_shared(skb) || skb_head_is_locked(skb) ||
584 skb_is_nonlinear(skb) || headroom < XDP_PACKET_HEADROOM) {
585 struct sk_buff *nskb;
586 int size, head_off;
587 void *head, *start;
588 struct page *page;
589
590 size = SKB_DATA_ALIGN(VETH_XDP_HEADROOM + pktlen) +
591 SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
592 if (size > PAGE_SIZE)
593 goto drop;
594
595 page = alloc_page(GFP_ATOMIC | __GFP_NOWARN);
596 if (!page)
597 goto drop;
598
599 head = page_address(page);
600 start = head + VETH_XDP_HEADROOM;
601 if (skb_copy_bits(skb, -mac_len, start, pktlen)) {
602 page_frag_free(head);
603 goto drop;
604 }
605
606 nskb = veth_build_skb(head,
607 VETH_XDP_HEADROOM + mac_len, skb->len,
608 PAGE_SIZE);
609 if (!nskb) {
610 page_frag_free(head);
611 goto drop;
612 }
613
614 skb_copy_header(nskb, skb);
615 head_off = skb_headroom(nskb) - skb_headroom(skb);
616 skb_headers_offset_update(nskb, head_off);
617 consume_skb(skb);
618 skb = nskb;
619 }
620
621 xdp.data_hard_start = skb->head;
622 xdp.data = skb_mac_header(skb);
623 xdp.data_end = xdp.data + pktlen;
624 xdp.data_meta = xdp.data;
625 xdp.rxq = &rq->xdp_rxq;
626 orig_data = xdp.data;
627 orig_data_end = xdp.data_end;
628
629 act = bpf_prog_run_xdp(xdp_prog, &xdp);
630
631 switch (act) {
632 case XDP_PASS:
633 break;
634 case XDP_TX:
635 get_page(virt_to_page(xdp.data));
636 consume_skb(skb);
637 xdp.rxq->mem = rq->xdp_mem;
638 if (unlikely(veth_xdp_tx(rq->dev, &xdp) < 0)) {
639 trace_xdp_exception(rq->dev, xdp_prog, act);
640 goto err_xdp;
641 }
642 *xdp_xmit |= VETH_XDP_TX;
643 rcu_read_unlock();
644 goto xdp_xmit;
645 case XDP_REDIRECT:
646 get_page(virt_to_page(xdp.data));
647 consume_skb(skb);
648 xdp.rxq->mem = rq->xdp_mem;
649 if (xdp_do_redirect(rq->dev, &xdp, xdp_prog))
650 goto err_xdp;
651 *xdp_xmit |= VETH_XDP_REDIR;
652 rcu_read_unlock();
653 goto xdp_xmit;
654 default:
655 bpf_warn_invalid_xdp_action(act);
656 /* fall through */
657 case XDP_ABORTED:
658 trace_xdp_exception(rq->dev, xdp_prog, act);
659 /* fall through */
660 case XDP_DROP:
661 goto drop;
662 }
663 rcu_read_unlock();
664
665 delta = orig_data - xdp.data;
666 off = mac_len + delta;
667 if (off > 0)
668 __skb_push(skb, off);
669 else if (off < 0)
670 __skb_pull(skb, -off);
671 skb->mac_header -= delta;
672 off = xdp.data_end - orig_data_end;
673 if (off != 0)
674 __skb_put(skb, off);
675 skb->protocol = eth_type_trans(skb, rq->dev);
676
677 metalen = xdp.data - xdp.data_meta;
678 if (metalen)
679 skb_metadata_set(skb, metalen);
680 out:
681 return skb;
682 drop:
683 rcu_read_unlock();
684 kfree_skb(skb);
685 return NULL;
686 err_xdp:
687 rcu_read_unlock();
688 page_frag_free(xdp.data);
689 xdp_xmit:
690 return NULL;
691 }
692
693 static int veth_xdp_rcv(struct veth_rq *rq, int budget, unsigned int *xdp_xmit)
694 {
695 int i, done = 0, drops = 0, bytes = 0;
696
697 for (i = 0; i < budget; i++) {
698 void *ptr = __ptr_ring_consume(&rq->xdp_ring);
699 unsigned int xdp_xmit_one = 0;
700 struct sk_buff *skb;
701
702 if (!ptr)
703 break;
704
705 if (veth_is_xdp_frame(ptr)) {
706 struct xdp_frame *frame = veth_ptr_to_xdp(ptr);
707
708 bytes += frame->len;
709 skb = veth_xdp_rcv_one(rq, frame, &xdp_xmit_one);
710 } else {
711 skb = ptr;
712 bytes += skb->len;
713 skb = veth_xdp_rcv_skb(rq, skb, &xdp_xmit_one);
714 }
715 *xdp_xmit |= xdp_xmit_one;
716
717 if (skb)
718 napi_gro_receive(&rq->xdp_napi, skb);
719 else if (!xdp_xmit_one)
720 drops++;
721
722 done++;
723 }
724
725 u64_stats_update_begin(&rq->stats.syncp);
726 rq->stats.xdp_packets += done;
727 rq->stats.xdp_bytes += bytes;
728 rq->stats.xdp_drops += drops;
729 u64_stats_update_end(&rq->stats.syncp);
730
731 return done;
732 }
733
734 static int veth_poll(struct napi_struct *napi, int budget)
735 {
736 struct veth_rq *rq =
737 container_of(napi, struct veth_rq, xdp_napi);
738 unsigned int xdp_xmit = 0;
739 int done;
740
741 xdp_set_return_frame_no_direct();
742 done = veth_xdp_rcv(rq, budget, &xdp_xmit);
743
744 if (done < budget && napi_complete_done(napi, done)) {
745 /* Write rx_notify_masked before reading ptr_ring */
746 smp_store_mb(rq->rx_notify_masked, false);
747 if (unlikely(!__ptr_ring_empty(&rq->xdp_ring))) {
748 rq->rx_notify_masked = true;
749 napi_schedule(&rq->xdp_napi);
750 }
751 }
752
753 if (xdp_xmit & VETH_XDP_TX)
754 veth_xdp_flush(rq->dev);
755 if (xdp_xmit & VETH_XDP_REDIR)
756 xdp_do_flush_map();
757 xdp_clear_return_frame_no_direct();
758
759 return done;
760 }
761
762 static int veth_napi_add(struct net_device *dev)
763 {
764 struct veth_priv *priv = netdev_priv(dev);
765 int err, i;
766
767 for (i = 0; i < dev->real_num_rx_queues; i++) {
768 struct veth_rq *rq = &priv->rq[i];
769
770 err = ptr_ring_init(&rq->xdp_ring, VETH_RING_SIZE, GFP_KERNEL);
771 if (err)
772 goto err_xdp_ring;
773 }
774
775 for (i = 0; i < dev->real_num_rx_queues; i++) {
776 struct veth_rq *rq = &priv->rq[i];
777
778 netif_napi_add(dev, &rq->xdp_napi, veth_poll, NAPI_POLL_WEIGHT);
779 napi_enable(&rq->xdp_napi);
780 }
781
782 return 0;
783 err_xdp_ring:
784 for (i--; i >= 0; i--)
785 ptr_ring_cleanup(&priv->rq[i].xdp_ring, veth_ptr_free);
786
787 return err;
788 }
789
790 static void veth_napi_del(struct net_device *dev)
791 {
792 struct veth_priv *priv = netdev_priv(dev);
793 int i;
794
795 for (i = 0; i < dev->real_num_rx_queues; i++) {
796 struct veth_rq *rq = &priv->rq[i];
797
798 napi_disable(&rq->xdp_napi);
799 napi_hash_del(&rq->xdp_napi);
800 }
801 synchronize_net();
802
803 for (i = 0; i < dev->real_num_rx_queues; i++) {
804 struct veth_rq *rq = &priv->rq[i];
805
806 netif_napi_del(&rq->xdp_napi);
807 rq->rx_notify_masked = false;
808 ptr_ring_cleanup(&rq->xdp_ring, veth_ptr_free);
809 }
810 }
811
812 static int veth_enable_xdp(struct net_device *dev)
813 {
814 struct veth_priv *priv = netdev_priv(dev);
815 int err, i;
816
817 if (!xdp_rxq_info_is_reg(&priv->rq[0].xdp_rxq)) {
818 for (i = 0; i < dev->real_num_rx_queues; i++) {
819 struct veth_rq *rq = &priv->rq[i];
820
821 err = xdp_rxq_info_reg(&rq->xdp_rxq, dev, i);
822 if (err < 0)
823 goto err_rxq_reg;
824
825 err = xdp_rxq_info_reg_mem_model(&rq->xdp_rxq,
826 MEM_TYPE_PAGE_SHARED,
827 NULL);
828 if (err < 0)
829 goto err_reg_mem;
830
831 /* Save original mem info as it can be overwritten */
832 rq->xdp_mem = rq->xdp_rxq.mem;
833 }
834
835 err = veth_napi_add(dev);
836 if (err)
837 goto err_rxq_reg;
838 }
839
840 for (i = 0; i < dev->real_num_rx_queues; i++)
841 rcu_assign_pointer(priv->rq[i].xdp_prog, priv->_xdp_prog);
842
843 return 0;
844 err_reg_mem:
845 xdp_rxq_info_unreg(&priv->rq[i].xdp_rxq);
846 err_rxq_reg:
847 for (i--; i >= 0; i--)
848 xdp_rxq_info_unreg(&priv->rq[i].xdp_rxq);
849
850 return err;
851 }
852
853 static void veth_disable_xdp(struct net_device *dev)
854 {
855 struct veth_priv *priv = netdev_priv(dev);
856 int i;
857
858 for (i = 0; i < dev->real_num_rx_queues; i++)
859 rcu_assign_pointer(priv->rq[i].xdp_prog, NULL);
860 veth_napi_del(dev);
861 for (i = 0; i < dev->real_num_rx_queues; i++) {
862 struct veth_rq *rq = &priv->rq[i];
863
864 rq->xdp_rxq.mem = rq->xdp_mem;
865 xdp_rxq_info_unreg(&rq->xdp_rxq);
866 }
867 }
868
869 static int veth_open(struct net_device *dev)
870 {
871 struct veth_priv *priv = netdev_priv(dev);
872 struct net_device *peer = rtnl_dereference(priv->peer);
873 int err;
874
875 if (!peer)
876 return -ENOTCONN;
877
878 if (priv->_xdp_prog) {
879 err = veth_enable_xdp(dev);
880 if (err)
881 return err;
882 }
883
884 if (peer->flags & IFF_UP) {
885 netif_carrier_on(dev);
886 netif_carrier_on(peer);
887 }
888
889 return 0;
890 }
891
892 static int veth_close(struct net_device *dev)
893 {
894 struct veth_priv *priv = netdev_priv(dev);
895 struct net_device *peer = rtnl_dereference(priv->peer);
896
897 netif_carrier_off(dev);
898 if (peer)
899 netif_carrier_off(peer);
900
901 if (priv->_xdp_prog)
902 veth_disable_xdp(dev);
903
904 return 0;
905 }
906
907 static int is_valid_veth_mtu(int mtu)
908 {
909 return mtu >= ETH_MIN_MTU && mtu <= ETH_MAX_MTU;
910 }
911
912 static int veth_alloc_queues(struct net_device *dev)
913 {
914 struct veth_priv *priv = netdev_priv(dev);
915 int i;
916
917 priv->rq = kcalloc(dev->num_rx_queues, sizeof(*priv->rq), GFP_KERNEL);
918 if (!priv->rq)
919 return -ENOMEM;
920
921 for (i = 0; i < dev->num_rx_queues; i++) {
922 priv->rq[i].dev = dev;
923 u64_stats_init(&priv->rq[i].stats.syncp);
924 }
925
926 return 0;
927 }
928
929 static void veth_free_queues(struct net_device *dev)
930 {
931 struct veth_priv *priv = netdev_priv(dev);
932
933 kfree(priv->rq);
934 }
935
936 static int veth_dev_init(struct net_device *dev)
937 {
938 int err;
939
940 dev->lstats = netdev_alloc_pcpu_stats(struct pcpu_lstats);
941 if (!dev->lstats)
942 return -ENOMEM;
943
944 err = veth_alloc_queues(dev);
945 if (err) {
946 free_percpu(dev->lstats);
947 return err;
948 }
949
950 return 0;
951 }
952
953 static void veth_dev_free(struct net_device *dev)
954 {
955 veth_free_queues(dev);
956 free_percpu(dev->lstats);
957 }
958
959 #ifdef CONFIG_NET_POLL_CONTROLLER
960 static void veth_poll_controller(struct net_device *dev)
961 {
962 /* veth only receives frames when its peer sends one
963 * Since it has nothing to do with disabling irqs, we are guaranteed
964 * never to have pending data when we poll for it so
965 * there is nothing to do here.
966 *
967 * We need this though so netpoll recognizes us as an interface that
968 * supports polling, which enables bridge devices in virt setups to
969 * still use netconsole
970 */
971 }
972 #endif /* CONFIG_NET_POLL_CONTROLLER */
973
974 static int veth_get_iflink(const struct net_device *dev)
975 {
976 struct veth_priv *priv = netdev_priv(dev);
977 struct net_device *peer;
978 int iflink;
979
980 rcu_read_lock();
981 peer = rcu_dereference(priv->peer);
982 iflink = peer ? peer->ifindex : 0;
983 rcu_read_unlock();
984
985 return iflink;
986 }
987
988 static netdev_features_t veth_fix_features(struct net_device *dev,
989 netdev_features_t features)
990 {
991 struct veth_priv *priv = netdev_priv(dev);
992 struct net_device *peer;
993
994 peer = rtnl_dereference(priv->peer);
995 if (peer) {
996 struct veth_priv *peer_priv = netdev_priv(peer);
997
998 if (peer_priv->_xdp_prog)
999 features &= ~NETIF_F_GSO_SOFTWARE;
1000 }
1001
1002 return features;
1003 }
1004
1005 static void veth_set_rx_headroom(struct net_device *dev, int new_hr)
1006 {
1007 struct veth_priv *peer_priv, *priv = netdev_priv(dev);
1008 struct net_device *peer;
1009
1010 if (new_hr < 0)
1011 new_hr = 0;
1012
1013 rcu_read_lock();
1014 peer = rcu_dereference(priv->peer);
1015 if (unlikely(!peer))
1016 goto out;
1017
1018 peer_priv = netdev_priv(peer);
1019 priv->requested_headroom = new_hr;
1020 new_hr = max(priv->requested_headroom, peer_priv->requested_headroom);
1021 dev->needed_headroom = new_hr;
1022 peer->needed_headroom = new_hr;
1023
1024 out:
1025 rcu_read_unlock();
1026 }
1027
1028 static int veth_xdp_set(struct net_device *dev, struct bpf_prog *prog,
1029 struct netlink_ext_ack *extack)
1030 {
1031 struct veth_priv *priv = netdev_priv(dev);
1032 struct bpf_prog *old_prog;
1033 struct net_device *peer;
1034 unsigned int max_mtu;
1035 int err;
1036
1037 old_prog = priv->_xdp_prog;
1038 priv->_xdp_prog = prog;
1039 peer = rtnl_dereference(priv->peer);
1040
1041 if (prog) {
1042 if (!peer) {
1043 NL_SET_ERR_MSG_MOD(extack, "Cannot set XDP when peer is detached");
1044 err = -ENOTCONN;
1045 goto err;
1046 }
1047
1048 max_mtu = PAGE_SIZE - VETH_XDP_HEADROOM -
1049 peer->hard_header_len -
1050 SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
1051 if (peer->mtu > max_mtu) {
1052 NL_SET_ERR_MSG_MOD(extack, "Peer MTU is too large to set XDP");
1053 err = -ERANGE;
1054 goto err;
1055 }
1056
1057 if (dev->real_num_rx_queues < peer->real_num_tx_queues) {
1058 NL_SET_ERR_MSG_MOD(extack, "XDP expects number of rx queues not less than peer tx queues");
1059 err = -ENOSPC;
1060 goto err;
1061 }
1062
1063 if (dev->flags & IFF_UP) {
1064 err = veth_enable_xdp(dev);
1065 if (err) {
1066 NL_SET_ERR_MSG_MOD(extack, "Setup for XDP failed");
1067 goto err;
1068 }
1069 }
1070
1071 if (!old_prog) {
1072 peer->hw_features &= ~NETIF_F_GSO_SOFTWARE;
1073 peer->max_mtu = max_mtu;
1074 }
1075 }
1076
1077 if (old_prog) {
1078 if (!prog) {
1079 if (dev->flags & IFF_UP)
1080 veth_disable_xdp(dev);
1081
1082 if (peer) {
1083 peer->hw_features |= NETIF_F_GSO_SOFTWARE;
1084 peer->max_mtu = ETH_MAX_MTU;
1085 }
1086 }
1087 bpf_prog_put(old_prog);
1088 }
1089
1090 if ((!!old_prog ^ !!prog) && peer)
1091 netdev_update_features(peer);
1092
1093 return 0;
1094 err:
1095 priv->_xdp_prog = old_prog;
1096
1097 return err;
1098 }
1099
1100 static u32 veth_xdp_query(struct net_device *dev)
1101 {
1102 struct veth_priv *priv = netdev_priv(dev);
1103 const struct bpf_prog *xdp_prog;
1104
1105 xdp_prog = priv->_xdp_prog;
1106 if (xdp_prog)
1107 return xdp_prog->aux->id;
1108
1109 return 0;
1110 }
1111
1112 static int veth_xdp(struct net_device *dev, struct netdev_bpf *xdp)
1113 {
1114 switch (xdp->command) {
1115 case XDP_SETUP_PROG:
1116 return veth_xdp_set(dev, xdp->prog, xdp->extack);
1117 case XDP_QUERY_PROG:
1118 xdp->prog_id = veth_xdp_query(dev);
1119 return 0;
1120 default:
1121 return -EINVAL;
1122 }
1123 }
1124
1125 static const struct net_device_ops veth_netdev_ops = {
1126 .ndo_init = veth_dev_init,
1127 .ndo_open = veth_open,
1128 .ndo_stop = veth_close,
1129 .ndo_start_xmit = veth_xmit,
1130 .ndo_get_stats64 = veth_get_stats64,
1131 .ndo_set_rx_mode = veth_set_multicast_list,
1132 .ndo_set_mac_address = eth_mac_addr,
1133 #ifdef CONFIG_NET_POLL_CONTROLLER
1134 .ndo_poll_controller = veth_poll_controller,
1135 #endif
1136 .ndo_get_iflink = veth_get_iflink,
1137 .ndo_fix_features = veth_fix_features,
1138 .ndo_features_check = passthru_features_check,
1139 .ndo_set_rx_headroom = veth_set_rx_headroom,
1140 .ndo_bpf = veth_xdp,
1141 .ndo_xdp_xmit = veth_xdp_xmit,
1142 };
1143
1144 #define VETH_FEATURES (NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HW_CSUM | \
1145 NETIF_F_RXCSUM | NETIF_F_SCTP_CRC | NETIF_F_HIGHDMA | \
1146 NETIF_F_GSO_SOFTWARE | NETIF_F_GSO_ENCAP_ALL | \
1147 NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_CTAG_RX | \
1148 NETIF_F_HW_VLAN_STAG_TX | NETIF_F_HW_VLAN_STAG_RX )
1149
1150 static void veth_setup(struct net_device *dev)
1151 {
1152 ether_setup(dev);
1153
1154 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1155 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1156 dev->priv_flags |= IFF_NO_QUEUE;
1157 dev->priv_flags |= IFF_PHONY_HEADROOM;
1158
1159 dev->netdev_ops = &veth_netdev_ops;
1160 dev->ethtool_ops = &veth_ethtool_ops;
1161 dev->features |= NETIF_F_LLTX;
1162 dev->features |= VETH_FEATURES;
1163 dev->vlan_features = dev->features &
1164 ~(NETIF_F_HW_VLAN_CTAG_TX |
1165 NETIF_F_HW_VLAN_STAG_TX |
1166 NETIF_F_HW_VLAN_CTAG_RX |
1167 NETIF_F_HW_VLAN_STAG_RX);
1168 dev->needs_free_netdev = true;
1169 dev->priv_destructor = veth_dev_free;
1170 dev->max_mtu = ETH_MAX_MTU;
1171
1172 dev->hw_features = VETH_FEATURES;
1173 dev->hw_enc_features = VETH_FEATURES;
1174 dev->mpls_features = NETIF_F_HW_CSUM | NETIF_F_GSO_SOFTWARE;
1175 }
1176
1177 /*
1178 * netlink interface
1179 */
1180
1181 static int veth_validate(struct nlattr *tb[], struct nlattr *data[],
1182 struct netlink_ext_ack *extack)
1183 {
1184 if (tb[IFLA_ADDRESS]) {
1185 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1186 return -EINVAL;
1187 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1188 return -EADDRNOTAVAIL;
1189 }
1190 if (tb[IFLA_MTU]) {
1191 if (!is_valid_veth_mtu(nla_get_u32(tb[IFLA_MTU])))
1192 return -EINVAL;
1193 }
1194 return 0;
1195 }
1196
1197 static struct rtnl_link_ops veth_link_ops;
1198
1199 static int veth_newlink(struct net *src_net, struct net_device *dev,
1200 struct nlattr *tb[], struct nlattr *data[],
1201 struct netlink_ext_ack *extack)
1202 {
1203 int err;
1204 struct net_device *peer;
1205 struct veth_priv *priv;
1206 char ifname[IFNAMSIZ];
1207 struct nlattr *peer_tb[IFLA_MAX + 1], **tbp;
1208 unsigned char name_assign_type;
1209 struct ifinfomsg *ifmp;
1210 struct net *net;
1211
1212 /*
1213 * create and register peer first
1214 */
1215 if (data != NULL && data[VETH_INFO_PEER] != NULL) {
1216 struct nlattr *nla_peer;
1217
1218 nla_peer = data[VETH_INFO_PEER];
1219 ifmp = nla_data(nla_peer);
1220 err = rtnl_nla_parse_ifla(peer_tb,
1221 nla_data(nla_peer) + sizeof(struct ifinfomsg),
1222 nla_len(nla_peer) - sizeof(struct ifinfomsg),
1223 NULL);
1224 if (err < 0)
1225 return err;
1226
1227 err = veth_validate(peer_tb, NULL, extack);
1228 if (err < 0)
1229 return err;
1230
1231 tbp = peer_tb;
1232 } else {
1233 ifmp = NULL;
1234 tbp = tb;
1235 }
1236
1237 if (ifmp && tbp[IFLA_IFNAME]) {
1238 nla_strlcpy(ifname, tbp[IFLA_IFNAME], IFNAMSIZ);
1239 name_assign_type = NET_NAME_USER;
1240 } else {
1241 snprintf(ifname, IFNAMSIZ, DRV_NAME "%%d");
1242 name_assign_type = NET_NAME_ENUM;
1243 }
1244
1245 net = rtnl_link_get_net(src_net, tbp);
1246 if (IS_ERR(net))
1247 return PTR_ERR(net);
1248
1249 peer = rtnl_create_link(net, ifname, name_assign_type,
1250 &veth_link_ops, tbp, extack);
1251 if (IS_ERR(peer)) {
1252 put_net(net);
1253 return PTR_ERR(peer);
1254 }
1255
1256 if (!ifmp || !tbp[IFLA_ADDRESS])
1257 eth_hw_addr_random(peer);
1258
1259 if (ifmp && (dev->ifindex != 0))
1260 peer->ifindex = ifmp->ifi_index;
1261
1262 peer->gso_max_size = dev->gso_max_size;
1263 peer->gso_max_segs = dev->gso_max_segs;
1264
1265 err = register_netdevice(peer);
1266 put_net(net);
1267 net = NULL;
1268 if (err < 0)
1269 goto err_register_peer;
1270
1271 netif_carrier_off(peer);
1272
1273 err = rtnl_configure_link(peer, ifmp);
1274 if (err < 0)
1275 goto err_configure_peer;
1276
1277 /*
1278 * register dev last
1279 *
1280 * note, that since we've registered new device the dev's name
1281 * should be re-allocated
1282 */
1283
1284 if (tb[IFLA_ADDRESS] == NULL)
1285 eth_hw_addr_random(dev);
1286
1287 if (tb[IFLA_IFNAME])
1288 nla_strlcpy(dev->name, tb[IFLA_IFNAME], IFNAMSIZ);
1289 else
1290 snprintf(dev->name, IFNAMSIZ, DRV_NAME "%%d");
1291
1292 err = register_netdevice(dev);
1293 if (err < 0)
1294 goto err_register_dev;
1295
1296 netif_carrier_off(dev);
1297
1298 /*
1299 * tie the deviced together
1300 */
1301
1302 priv = netdev_priv(dev);
1303 rcu_assign_pointer(priv->peer, peer);
1304
1305 priv = netdev_priv(peer);
1306 rcu_assign_pointer(priv->peer, dev);
1307
1308 return 0;
1309
1310 err_register_dev:
1311 /* nothing to do */
1312 err_configure_peer:
1313 unregister_netdevice(peer);
1314 return err;
1315
1316 err_register_peer:
1317 free_netdev(peer);
1318 return err;
1319 }
1320
1321 static void veth_dellink(struct net_device *dev, struct list_head *head)
1322 {
1323 struct veth_priv *priv;
1324 struct net_device *peer;
1325
1326 priv = netdev_priv(dev);
1327 peer = rtnl_dereference(priv->peer);
1328
1329 /* Note : dellink() is called from default_device_exit_batch(),
1330 * before a rcu_synchronize() point. The devices are guaranteed
1331 * not being freed before one RCU grace period.
1332 */
1333 RCU_INIT_POINTER(priv->peer, NULL);
1334 unregister_netdevice_queue(dev, head);
1335
1336 if (peer) {
1337 priv = netdev_priv(peer);
1338 RCU_INIT_POINTER(priv->peer, NULL);
1339 unregister_netdevice_queue(peer, head);
1340 }
1341 }
1342
1343 static const struct nla_policy veth_policy[VETH_INFO_MAX + 1] = {
1344 [VETH_INFO_PEER] = { .len = sizeof(struct ifinfomsg) },
1345 };
1346
1347 static struct net *veth_get_link_net(const struct net_device *dev)
1348 {
1349 struct veth_priv *priv = netdev_priv(dev);
1350 struct net_device *peer = rtnl_dereference(priv->peer);
1351
1352 return peer ? dev_net(peer) : dev_net(dev);
1353 }
1354
1355 static struct rtnl_link_ops veth_link_ops = {
1356 .kind = DRV_NAME,
1357 .priv_size = sizeof(struct veth_priv),
1358 .setup = veth_setup,
1359 .validate = veth_validate,
1360 .newlink = veth_newlink,
1361 .dellink = veth_dellink,
1362 .policy = veth_policy,
1363 .maxtype = VETH_INFO_MAX,
1364 .get_link_net = veth_get_link_net,
1365 };
1366
1367 /*
1368 * init/fini
1369 */
1370
1371 static __init int veth_init(void)
1372 {
1373 return rtnl_link_register(&veth_link_ops);
1374 }
1375
1376 static __exit void veth_exit(void)
1377 {
1378 rtnl_link_unregister(&veth_link_ops);
1379 }
1380
1381 module_init(veth_init);
1382 module_exit(veth_exit);
1383
1384 MODULE_DESCRIPTION("Virtual Ethernet Tunnel");
1385 MODULE_LICENSE("GPL v2");
1386 MODULE_ALIAS_RTNL_LINK(DRV_NAME);
Linux with added FPC-III support