This source file includes following definitions.
- veth_get_link_ksettings
- veth_get_drvinfo
- veth_get_strings
- veth_get_sset_count
- veth_get_ethtool_stats
- veth_is_xdp_frame
- veth_ptr_to_xdp
- veth_xdp_to_ptr
- veth_ptr_free
- __veth_xdp_flush
- veth_xdp_rx
- veth_forward_skb
- veth_xmit
- veth_stats_tx
- veth_stats_rx
- veth_get_stats64
- veth_set_multicast_list
- veth_build_skb
- veth_select_rxq
- veth_xdp_xmit
- veth_xdp_flush_bq
- veth_xdp_flush
- veth_xdp_tx
- veth_xdp_rcv_one
- veth_xdp_rcv_skb
- veth_xdp_rcv
- veth_poll
- veth_napi_add
- veth_napi_del
- veth_enable_xdp
- veth_disable_xdp
- veth_open
- veth_close
- is_valid_veth_mtu
- veth_alloc_queues
- veth_free_queues
- veth_dev_init
- veth_dev_free
- veth_poll_controller
- veth_get_iflink
- veth_fix_features
- veth_set_rx_headroom
- veth_xdp_set
- veth_xdp_query
- veth_xdp
- veth_setup
- veth_validate
- veth_newlink
- veth_dellink
- veth_get_link_net
- veth_init
- veth_exit
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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
38 #define VETH_XDP_TX BIT(0)
39 #define VETH_XDP_REDIR BIT(1)
40
41 #define VETH_XDP_TX_BULK_SIZE 16
42
43 struct veth_rq_stats {
44 u64 xdp_packets;
45 u64 xdp_bytes;
46 u64 xdp_drops;
47 struct u64_stats_sync syncp;
48 };
49
50 struct veth_rq {
51 struct napi_struct xdp_napi;
52 struct net_device *dev;
53 struct bpf_prog __rcu *xdp_prog;
54 struct xdp_mem_info xdp_mem;
55 struct veth_rq_stats stats;
56 bool rx_notify_masked;
57 struct ptr_ring xdp_ring;
58 struct xdp_rxq_info xdp_rxq;
59 };
60
61 struct veth_priv {
62 struct net_device __rcu *peer;
63 atomic64_t dropped;
64 struct bpf_prog *_xdp_prog;
65 struct veth_rq *rq;
66 unsigned int requested_headroom;
67 };
68
69 struct veth_xdp_tx_bq {
70 struct xdp_frame *q[VETH_XDP_TX_BULK_SIZE];
71 unsigned int count;
72 };
73
74
75
76
77
78 struct veth_q_stat_desc {
79 char desc[ETH_GSTRING_LEN];
80 size_t offset;
81 };
82
83 #define VETH_RQ_STAT(m) offsetof(struct veth_rq_stats, m)
84
85 static const struct veth_q_stat_desc veth_rq_stats_desc[] = {
86 { "xdp_packets", VETH_RQ_STAT(xdp_packets) },
87 { "xdp_bytes", VETH_RQ_STAT(xdp_bytes) },
88 { "xdp_drops", VETH_RQ_STAT(xdp_drops) },
89 };
90
91 #define VETH_RQ_STATS_LEN ARRAY_SIZE(veth_rq_stats_desc)
92
93 static struct {
94 const char string[ETH_GSTRING_LEN];
95 } ethtool_stats_keys[] = {
96 { "peer_ifindex" },
97 };
98
99 static int veth_get_link_ksettings(struct net_device *dev,
100 struct ethtool_link_ksettings *cmd)
101 {
102 cmd->base.speed = SPEED_10000;
103 cmd->base.duplex = DUPLEX_FULL;
104 cmd->base.port = PORT_TP;
105 cmd->base.autoneg = AUTONEG_DISABLE;
106 return 0;
107 }
108
109 static void veth_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
110 {
111 strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
112 strlcpy(info->version, DRV_VERSION, sizeof(info->version));
113 }
114
115 static void veth_get_strings(struct net_device *dev, u32 stringset, u8 *buf)
116 {
117 char *p = (char *)buf;
118 int i, j;
119
120 switch(stringset) {
121 case ETH_SS_STATS:
122 memcpy(p, ðtool_stats_keys, sizeof(ethtool_stats_keys));
123 p += sizeof(ethtool_stats_keys);
124 for (i = 0; i < dev->real_num_rx_queues; i++) {
125 for (j = 0; j < VETH_RQ_STATS_LEN; j++) {
126 snprintf(p, ETH_GSTRING_LEN,
127 "rx_queue_%u_%.11s",
128 i, veth_rq_stats_desc[j].desc);
129 p += ETH_GSTRING_LEN;
130 }
131 }
132 break;
133 }
134 }
135
136 static int veth_get_sset_count(struct net_device *dev, int sset)
137 {
138 switch (sset) {
139 case ETH_SS_STATS:
140 return ARRAY_SIZE(ethtool_stats_keys) +
141 VETH_RQ_STATS_LEN * dev->real_num_rx_queues;
142 default:
143 return -EOPNOTSUPP;
144 }
145 }
146
147 static void veth_get_ethtool_stats(struct net_device *dev,
148 struct ethtool_stats *stats, u64 *data)
149 {
150 struct veth_priv *priv = netdev_priv(dev);
151 struct net_device *peer = rtnl_dereference(priv->peer);
152 int i, j, idx;
153
154 data[0] = peer ? peer->ifindex : 0;
155 idx = 1;
156 for (i = 0; i < dev->real_num_rx_queues; i++) {
157 const struct veth_rq_stats *rq_stats = &priv->rq[i].stats;
158 const void *stats_base = (void *)rq_stats;
159 unsigned int start;
160 size_t offset;
161
162 do {
163 start = u64_stats_fetch_begin_irq(&rq_stats->syncp);
164 for (j = 0; j < VETH_RQ_STATS_LEN; j++) {
165 offset = veth_rq_stats_desc[j].offset;
166 data[idx + j] = *(u64 *)(stats_base + offset);
167 }
168 } while (u64_stats_fetch_retry_irq(&rq_stats->syncp, start));
169 idx += VETH_RQ_STATS_LEN;
170 }
171 }
172
173 static const struct ethtool_ops veth_ethtool_ops = {
174 .get_drvinfo = veth_get_drvinfo,
175 .get_link = ethtool_op_get_link,
176 .get_strings = veth_get_strings,
177 .get_sset_count = veth_get_sset_count,
178 .get_ethtool_stats = veth_get_ethtool_stats,
179 .get_link_ksettings = veth_get_link_ksettings,
180 .get_ts_info = ethtool_op_get_ts_info,
181 };
182
183
184
185 static bool veth_is_xdp_frame(void *ptr)
186 {
187 return (unsigned long)ptr & VETH_XDP_FLAG;
188 }
189
190 static void *veth_ptr_to_xdp(void *ptr)
191 {
192 return (void *)((unsigned long)ptr & ~VETH_XDP_FLAG);
193 }
194
195 static void *veth_xdp_to_ptr(void *ptr)
196 {
197 return (void *)((unsigned long)ptr | VETH_XDP_FLAG);
198 }
199
200 static void veth_ptr_free(void *ptr)
201 {
202 if (veth_is_xdp_frame(ptr))
203 xdp_return_frame(veth_ptr_to_xdp(ptr));
204 else
205 kfree_skb(ptr);
206 }
207
208 static void __veth_xdp_flush(struct veth_rq *rq)
209 {
210
211 smp_mb();
212 if (!rq->rx_notify_masked) {
213 rq->rx_notify_masked = true;
214 napi_schedule(&rq->xdp_napi);
215 }
216 }
217
218 static int veth_xdp_rx(struct veth_rq *rq, struct sk_buff *skb)
219 {
220 if (unlikely(ptr_ring_produce(&rq->xdp_ring, skb))) {
221 dev_kfree_skb_any(skb);
222 return NET_RX_DROP;
223 }
224
225 return NET_RX_SUCCESS;
226 }
227
228 static int veth_forward_skb(struct net_device *dev, struct sk_buff *skb,
229 struct veth_rq *rq, bool xdp)
230 {
231 return __dev_forward_skb(dev, skb) ?: xdp ?
232 veth_xdp_rx(rq, skb) :
233 netif_rx(skb);
234 }
235
236 static netdev_tx_t veth_xmit(struct sk_buff *skb, struct net_device *dev)
237 {
238 struct veth_priv *rcv_priv, *priv = netdev_priv(dev);
239 struct veth_rq *rq = NULL;
240 struct net_device *rcv;
241 int length = skb->len;
242 bool rcv_xdp = false;
243 int rxq;
244
245 rcu_read_lock();
246 rcv = rcu_dereference(priv->peer);
247 if (unlikely(!rcv)) {
248 kfree_skb(skb);
249 goto drop;
250 }
251
252 rcv_priv = netdev_priv(rcv);
253 rxq = skb_get_queue_mapping(skb);
254 if (rxq < rcv->real_num_rx_queues) {
255 rq = &rcv_priv->rq[rxq];
256 rcv_xdp = rcu_access_pointer(rq->xdp_prog);
257 if (rcv_xdp)
258 skb_record_rx_queue(skb, rxq);
259 }
260
261 skb_tx_timestamp(skb);
262 if (likely(veth_forward_skb(rcv, skb, rq, rcv_xdp) == NET_RX_SUCCESS)) {
263 if (!rcv_xdp) {
264 struct pcpu_lstats *stats = this_cpu_ptr(dev->lstats);
265
266 u64_stats_update_begin(&stats->syncp);
267 stats->bytes += length;
268 stats->packets++;
269 u64_stats_update_end(&stats->syncp);
270 }
271 } else {
272 drop:
273 atomic64_inc(&priv->dropped);
274 }
275
276 if (rcv_xdp)
277 __veth_xdp_flush(rq);
278
279 rcu_read_unlock();
280
281 return NETDEV_TX_OK;
282 }
283
284 static u64 veth_stats_tx(struct pcpu_lstats *result, struct net_device *dev)
285 {
286 struct veth_priv *priv = netdev_priv(dev);
287 int cpu;
288
289 result->packets = 0;
290 result->bytes = 0;
291 for_each_possible_cpu(cpu) {
292 struct pcpu_lstats *stats = per_cpu_ptr(dev->lstats, cpu);
293 u64 packets, bytes;
294 unsigned int start;
295
296 do {
297 start = u64_stats_fetch_begin_irq(&stats->syncp);
298 packets = stats->packets;
299 bytes = stats->bytes;
300 } while (u64_stats_fetch_retry_irq(&stats->syncp, start));
301 result->packets += packets;
302 result->bytes += bytes;
303 }
304 return atomic64_read(&priv->dropped);
305 }
306
307 static void veth_stats_rx(struct veth_rq_stats *result, struct net_device *dev)
308 {
309 struct veth_priv *priv = netdev_priv(dev);
310 int i;
311
312 result->xdp_packets = 0;
313 result->xdp_bytes = 0;
314 result->xdp_drops = 0;
315 for (i = 0; i < dev->num_rx_queues; i++) {
316 struct veth_rq_stats *stats = &priv->rq[i].stats;
317 u64 packets, bytes, drops;
318 unsigned int start;
319
320 do {
321 start = u64_stats_fetch_begin_irq(&stats->syncp);
322 packets = stats->xdp_packets;
323 bytes = stats->xdp_bytes;
324 drops = stats->xdp_drops;
325 } while (u64_stats_fetch_retry_irq(&stats->syncp, start));
326 result->xdp_packets += packets;
327 result->xdp_bytes += bytes;
328 result->xdp_drops += drops;
329 }
330 }
331
332 static void veth_get_stats64(struct net_device *dev,
333 struct rtnl_link_stats64 *tot)
334 {
335 struct veth_priv *priv = netdev_priv(dev);
336 struct net_device *peer;
337 struct veth_rq_stats rx;
338 struct pcpu_lstats tx;
339
340 tot->tx_dropped = veth_stats_tx(&tx, dev);
341 tot->tx_bytes = tx.bytes;
342 tot->tx_packets = tx.packets;
343
344 veth_stats_rx(&rx, dev);
345 tot->rx_dropped = rx.xdp_drops;
346 tot->rx_bytes = rx.xdp_bytes;
347 tot->rx_packets = rx.xdp_packets;
348
349 rcu_read_lock();
350 peer = rcu_dereference(priv->peer);
351 if (peer) {
352 tot->rx_dropped += veth_stats_tx(&tx, peer);
353 tot->rx_bytes += tx.bytes;
354 tot->rx_packets += tx.packets;
355
356 veth_stats_rx(&rx, peer);
357 tot->tx_bytes += rx.xdp_bytes;
358 tot->tx_packets += rx.xdp_packets;
359 }
360 rcu_read_unlock();
361 }
362
363
364 static void veth_set_multicast_list(struct net_device *dev)
365 {
366 }
367
368 static struct sk_buff *veth_build_skb(void *head, int headroom, int len,
369 int buflen)
370 {
371 struct sk_buff *skb;
372
373 if (!buflen) {
374 buflen = SKB_DATA_ALIGN(headroom + len) +
375 SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
376 }
377 skb = build_skb(head, buflen);
378 if (!skb)
379 return NULL;
380
381 skb_reserve(skb, headroom);
382 skb_put(skb, len);
383
384 return skb;
385 }
386
387 static int veth_select_rxq(struct net_device *dev)
388 {
389 return smp_processor_id() % dev->real_num_rx_queues;
390 }
391
392 static int veth_xdp_xmit(struct net_device *dev, int n,
393 struct xdp_frame **frames, u32 flags)
394 {
395 struct veth_priv *rcv_priv, *priv = netdev_priv(dev);
396 struct net_device *rcv;
397 int i, ret, drops = n;
398 unsigned int max_len;
399 struct veth_rq *rq;
400
401 if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK)) {
402 ret = -EINVAL;
403 goto drop;
404 }
405
406 rcv = rcu_dereference(priv->peer);
407 if (unlikely(!rcv)) {
408 ret = -ENXIO;
409 goto drop;
410 }
411
412 rcv_priv = netdev_priv(rcv);
413 rq = &rcv_priv->rq[veth_select_rxq(rcv)];
414
415
416
417
418 if (!rcu_access_pointer(rq->xdp_prog)) {
419 ret = -ENXIO;
420 goto drop;
421 }
422
423 drops = 0;
424 max_len = rcv->mtu + rcv->hard_header_len + VLAN_HLEN;
425
426 spin_lock(&rq->xdp_ring.producer_lock);
427 for (i = 0; i < n; i++) {
428 struct xdp_frame *frame = frames[i];
429 void *ptr = veth_xdp_to_ptr(frame);
430
431 if (unlikely(frame->len > max_len ||
432 __ptr_ring_produce(&rq->xdp_ring, ptr))) {
433 xdp_return_frame_rx_napi(frame);
434 drops++;
435 }
436 }
437 spin_unlock(&rq->xdp_ring.producer_lock);
438
439 if (flags & XDP_XMIT_FLUSH)
440 __veth_xdp_flush(rq);
441
442 if (likely(!drops))
443 return n;
444
445 ret = n - drops;
446 drop:
447 atomic64_add(drops, &priv->dropped);
448
449 return ret;
450 }
451
452 static void veth_xdp_flush_bq(struct net_device *dev, struct veth_xdp_tx_bq *bq)
453 {
454 int sent, i, err = 0;
455
456 sent = veth_xdp_xmit(dev, bq->count, bq->q, 0);
457 if (sent < 0) {
458 err = sent;
459 sent = 0;
460 for (i = 0; i < bq->count; i++)
461 xdp_return_frame(bq->q[i]);
462 }
463 trace_xdp_bulk_tx(dev, sent, bq->count - sent, err);
464
465 bq->count = 0;
466 }
467
468 static void veth_xdp_flush(struct net_device *dev, struct veth_xdp_tx_bq *bq)
469 {
470 struct veth_priv *rcv_priv, *priv = netdev_priv(dev);
471 struct net_device *rcv;
472 struct veth_rq *rq;
473
474 rcu_read_lock();
475 veth_xdp_flush_bq(dev, bq);
476 rcv = rcu_dereference(priv->peer);
477 if (unlikely(!rcv))
478 goto out;
479
480 rcv_priv = netdev_priv(rcv);
481 rq = &rcv_priv->rq[veth_select_rxq(rcv)];
482
483 if (unlikely(!rcu_access_pointer(rq->xdp_prog)))
484 goto out;
485
486 __veth_xdp_flush(rq);
487 out:
488 rcu_read_unlock();
489 }
490
491 static int veth_xdp_tx(struct net_device *dev, struct xdp_buff *xdp,
492 struct veth_xdp_tx_bq *bq)
493 {
494 struct xdp_frame *frame = convert_to_xdp_frame(xdp);
495
496 if (unlikely(!frame))
497 return -EOVERFLOW;
498
499 if (unlikely(bq->count == VETH_XDP_TX_BULK_SIZE))
500 veth_xdp_flush_bq(dev, bq);
501
502 bq->q[bq->count++] = frame;
503
504 return 0;
505 }
506
507 static struct sk_buff *veth_xdp_rcv_one(struct veth_rq *rq,
508 struct xdp_frame *frame,
509 unsigned int *xdp_xmit,
510 struct veth_xdp_tx_bq *bq)
511 {
512 void *hard_start = frame->data - frame->headroom;
513 void *head = hard_start - sizeof(struct xdp_frame);
514 int len = frame->len, delta = 0;
515 struct xdp_frame orig_frame;
516 struct bpf_prog *xdp_prog;
517 unsigned int headroom;
518 struct sk_buff *skb;
519
520 rcu_read_lock();
521 xdp_prog = rcu_dereference(rq->xdp_prog);
522 if (likely(xdp_prog)) {
523 struct xdp_buff xdp;
524 u32 act;
525
526 xdp.data_hard_start = hard_start;
527 xdp.data = frame->data;
528 xdp.data_end = frame->data + frame->len;
529 xdp.data_meta = frame->data - frame->metasize;
530 xdp.rxq = &rq->xdp_rxq;
531
532 act = bpf_prog_run_xdp(xdp_prog, &xdp);
533
534 switch (act) {
535 case XDP_PASS:
536 delta = frame->data - xdp.data;
537 len = xdp.data_end - xdp.data;
538 break;
539 case XDP_TX:
540 orig_frame = *frame;
541 xdp.data_hard_start = head;
542 xdp.rxq->mem = frame->mem;
543 if (unlikely(veth_xdp_tx(rq->dev, &xdp, bq) < 0)) {
544 trace_xdp_exception(rq->dev, xdp_prog, act);
545 frame = &orig_frame;
546 goto err_xdp;
547 }
548 *xdp_xmit |= VETH_XDP_TX;
549 rcu_read_unlock();
550 goto xdp_xmit;
551 case XDP_REDIRECT:
552 orig_frame = *frame;
553 xdp.data_hard_start = head;
554 xdp.rxq->mem = frame->mem;
555 if (xdp_do_redirect(rq->dev, &xdp, xdp_prog)) {
556 frame = &orig_frame;
557 goto err_xdp;
558 }
559 *xdp_xmit |= VETH_XDP_REDIR;
560 rcu_read_unlock();
561 goto xdp_xmit;
562 default:
563 bpf_warn_invalid_xdp_action(act);
564
565 case XDP_ABORTED:
566 trace_xdp_exception(rq->dev, xdp_prog, act);
567
568 case XDP_DROP:
569 goto err_xdp;
570 }
571 }
572 rcu_read_unlock();
573
574 headroom = sizeof(struct xdp_frame) + frame->headroom - delta;
575 skb = veth_build_skb(head, headroom, len, 0);
576 if (!skb) {
577 xdp_return_frame(frame);
578 goto err;
579 }
580
581 xdp_release_frame(frame);
582 xdp_scrub_frame(frame);
583 skb->protocol = eth_type_trans(skb, rq->dev);
584 err:
585 return skb;
586 err_xdp:
587 rcu_read_unlock();
588 xdp_return_frame(frame);
589 xdp_xmit:
590 return NULL;
591 }
592
593 static struct sk_buff *veth_xdp_rcv_skb(struct veth_rq *rq, struct sk_buff *skb,
594 unsigned int *xdp_xmit,
595 struct veth_xdp_tx_bq *bq)
596 {
597 u32 pktlen, headroom, act, metalen;
598 void *orig_data, *orig_data_end;
599 struct bpf_prog *xdp_prog;
600 int mac_len, delta, off;
601 struct xdp_buff xdp;
602
603 skb_orphan(skb);
604
605 rcu_read_lock();
606 xdp_prog = rcu_dereference(rq->xdp_prog);
607 if (unlikely(!xdp_prog)) {
608 rcu_read_unlock();
609 goto out;
610 }
611
612 mac_len = skb->data - skb_mac_header(skb);
613 pktlen = skb->len + mac_len;
614 headroom = skb_headroom(skb) - mac_len;
615
616 if (skb_shared(skb) || skb_head_is_locked(skb) ||
617 skb_is_nonlinear(skb) || headroom < XDP_PACKET_HEADROOM) {
618 struct sk_buff *nskb;
619 int size, head_off;
620 void *head, *start;
621 struct page *page;
622
623 size = SKB_DATA_ALIGN(VETH_XDP_HEADROOM + pktlen) +
624 SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
625 if (size > PAGE_SIZE)
626 goto drop;
627
628 page = alloc_page(GFP_ATOMIC | __GFP_NOWARN);
629 if (!page)
630 goto drop;
631
632 head = page_address(page);
633 start = head + VETH_XDP_HEADROOM;
634 if (skb_copy_bits(skb, -mac_len, start, pktlen)) {
635 page_frag_free(head);
636 goto drop;
637 }
638
639 nskb = veth_build_skb(head,
640 VETH_XDP_HEADROOM + mac_len, skb->len,
641 PAGE_SIZE);
642 if (!nskb) {
643 page_frag_free(head);
644 goto drop;
645 }
646
647 skb_copy_header(nskb, skb);
648 head_off = skb_headroom(nskb) - skb_headroom(skb);
649 skb_headers_offset_update(nskb, head_off);
650 consume_skb(skb);
651 skb = nskb;
652 }
653
654 xdp.data_hard_start = skb->head;
655 xdp.data = skb_mac_header(skb);
656 xdp.data_end = xdp.data + pktlen;
657 xdp.data_meta = xdp.data;
658 xdp.rxq = &rq->xdp_rxq;
659 orig_data = xdp.data;
660 orig_data_end = xdp.data_end;
661
662 act = bpf_prog_run_xdp(xdp_prog, &xdp);
663
664 switch (act) {
665 case XDP_PASS:
666 break;
667 case XDP_TX:
668 get_page(virt_to_page(xdp.data));
669 consume_skb(skb);
670 xdp.rxq->mem = rq->xdp_mem;
671 if (unlikely(veth_xdp_tx(rq->dev, &xdp, bq) < 0)) {
672 trace_xdp_exception(rq->dev, xdp_prog, act);
673 goto err_xdp;
674 }
675 *xdp_xmit |= VETH_XDP_TX;
676 rcu_read_unlock();
677 goto xdp_xmit;
678 case XDP_REDIRECT:
679 get_page(virt_to_page(xdp.data));
680 consume_skb(skb);
681 xdp.rxq->mem = rq->xdp_mem;
682 if (xdp_do_redirect(rq->dev, &xdp, xdp_prog))
683 goto err_xdp;
684 *xdp_xmit |= VETH_XDP_REDIR;
685 rcu_read_unlock();
686 goto xdp_xmit;
687 default:
688 bpf_warn_invalid_xdp_action(act);
689
690 case XDP_ABORTED:
691 trace_xdp_exception(rq->dev, xdp_prog, act);
692
693 case XDP_DROP:
694 goto drop;
695 }
696 rcu_read_unlock();
697
698 delta = orig_data - xdp.data;
699 off = mac_len + delta;
700 if (off > 0)
701 __skb_push(skb, off);
702 else if (off < 0)
703 __skb_pull(skb, -off);
704 skb->mac_header -= delta;
705 off = xdp.data_end - orig_data_end;
706 if (off != 0)
707 __skb_put(skb, off);
708 skb->protocol = eth_type_trans(skb, rq->dev);
709
710 metalen = xdp.data - xdp.data_meta;
711 if (metalen)
712 skb_metadata_set(skb, metalen);
713 out:
714 return skb;
715 drop:
716 rcu_read_unlock();
717 kfree_skb(skb);
718 return NULL;
719 err_xdp:
720 rcu_read_unlock();
721 page_frag_free(xdp.data);
722 xdp_xmit:
723 return NULL;
724 }
725
726 static int veth_xdp_rcv(struct veth_rq *rq, int budget, unsigned int *xdp_xmit,
727 struct veth_xdp_tx_bq *bq)
728 {
729 int i, done = 0, drops = 0, bytes = 0;
730
731 for (i = 0; i < budget; i++) {
732 void *ptr = __ptr_ring_consume(&rq->xdp_ring);
733 unsigned int xdp_xmit_one = 0;
734 struct sk_buff *skb;
735
736 if (!ptr)
737 break;
738
739 if (veth_is_xdp_frame(ptr)) {
740 struct xdp_frame *frame = veth_ptr_to_xdp(ptr);
741
742 bytes += frame->len;
743 skb = veth_xdp_rcv_one(rq, frame, &xdp_xmit_one, bq);
744 } else {
745 skb = ptr;
746 bytes += skb->len;
747 skb = veth_xdp_rcv_skb(rq, skb, &xdp_xmit_one, bq);
748 }
749 *xdp_xmit |= xdp_xmit_one;
750
751 if (skb)
752 napi_gro_receive(&rq->xdp_napi, skb);
753 else if (!xdp_xmit_one)
754 drops++;
755
756 done++;
757 }
758
759 u64_stats_update_begin(&rq->stats.syncp);
760 rq->stats.xdp_packets += done;
761 rq->stats.xdp_bytes += bytes;
762 rq->stats.xdp_drops += drops;
763 u64_stats_update_end(&rq->stats.syncp);
764
765 return done;
766 }
767
768 static int veth_poll(struct napi_struct *napi, int budget)
769 {
770 struct veth_rq *rq =
771 container_of(napi, struct veth_rq, xdp_napi);
772 unsigned int xdp_xmit = 0;
773 struct veth_xdp_tx_bq bq;
774 int done;
775
776 bq.count = 0;
777
778 xdp_set_return_frame_no_direct();
779 done = veth_xdp_rcv(rq, budget, &xdp_xmit, &bq);
780
781 if (done < budget && napi_complete_done(napi, done)) {
782
783 smp_store_mb(rq->rx_notify_masked, false);
784 if (unlikely(!__ptr_ring_empty(&rq->xdp_ring))) {
785 rq->rx_notify_masked = true;
786 napi_schedule(&rq->xdp_napi);
787 }
788 }
789
790 if (xdp_xmit & VETH_XDP_TX)
791 veth_xdp_flush(rq->dev, &bq);
792 if (xdp_xmit & VETH_XDP_REDIR)
793 xdp_do_flush_map();
794 xdp_clear_return_frame_no_direct();
795
796 return done;
797 }
798
799 static int veth_napi_add(struct net_device *dev)
800 {
801 struct veth_priv *priv = netdev_priv(dev);
802 int err, i;
803
804 for (i = 0; i < dev->real_num_rx_queues; i++) {
805 struct veth_rq *rq = &priv->rq[i];
806
807 err = ptr_ring_init(&rq->xdp_ring, VETH_RING_SIZE, GFP_KERNEL);
808 if (err)
809 goto err_xdp_ring;
810 }
811
812 for (i = 0; i < dev->real_num_rx_queues; i++) {
813 struct veth_rq *rq = &priv->rq[i];
814
815 netif_napi_add(dev, &rq->xdp_napi, veth_poll, NAPI_POLL_WEIGHT);
816 napi_enable(&rq->xdp_napi);
817 }
818
819 return 0;
820 err_xdp_ring:
821 for (i--; i >= 0; i--)
822 ptr_ring_cleanup(&priv->rq[i].xdp_ring, veth_ptr_free);
823
824 return err;
825 }
826
827 static void veth_napi_del(struct net_device *dev)
828 {
829 struct veth_priv *priv = netdev_priv(dev);
830 int i;
831
832 for (i = 0; i < dev->real_num_rx_queues; i++) {
833 struct veth_rq *rq = &priv->rq[i];
834
835 napi_disable(&rq->xdp_napi);
836 napi_hash_del(&rq->xdp_napi);
837 }
838 synchronize_net();
839
840 for (i = 0; i < dev->real_num_rx_queues; i++) {
841 struct veth_rq *rq = &priv->rq[i];
842
843 netif_napi_del(&rq->xdp_napi);
844 rq->rx_notify_masked = false;
845 ptr_ring_cleanup(&rq->xdp_ring, veth_ptr_free);
846 }
847 }
848
849 static int veth_enable_xdp(struct net_device *dev)
850 {
851 struct veth_priv *priv = netdev_priv(dev);
852 int err, i;
853
854 if (!xdp_rxq_info_is_reg(&priv->rq[0].xdp_rxq)) {
855 for (i = 0; i < dev->real_num_rx_queues; i++) {
856 struct veth_rq *rq = &priv->rq[i];
857
858 err = xdp_rxq_info_reg(&rq->xdp_rxq, dev, i);
859 if (err < 0)
860 goto err_rxq_reg;
861
862 err = xdp_rxq_info_reg_mem_model(&rq->xdp_rxq,
863 MEM_TYPE_PAGE_SHARED,
864 NULL);
865 if (err < 0)
866 goto err_reg_mem;
867
868
869 rq->xdp_mem = rq->xdp_rxq.mem;
870 }
871
872 err = veth_napi_add(dev);
873 if (err)
874 goto err_rxq_reg;
875 }
876
877 for (i = 0; i < dev->real_num_rx_queues; i++)
878 rcu_assign_pointer(priv->rq[i].xdp_prog, priv->_xdp_prog);
879
880 return 0;
881 err_reg_mem:
882 xdp_rxq_info_unreg(&priv->rq[i].xdp_rxq);
883 err_rxq_reg:
884 for (i--; i >= 0; i--)
885 xdp_rxq_info_unreg(&priv->rq[i].xdp_rxq);
886
887 return err;
888 }
889
890 static void veth_disable_xdp(struct net_device *dev)
891 {
892 struct veth_priv *priv = netdev_priv(dev);
893 int i;
894
895 for (i = 0; i < dev->real_num_rx_queues; i++)
896 rcu_assign_pointer(priv->rq[i].xdp_prog, NULL);
897 veth_napi_del(dev);
898 for (i = 0; i < dev->real_num_rx_queues; i++) {
899 struct veth_rq *rq = &priv->rq[i];
900
901 rq->xdp_rxq.mem = rq->xdp_mem;
902 xdp_rxq_info_unreg(&rq->xdp_rxq);
903 }
904 }
905
906 static int veth_open(struct net_device *dev)
907 {
908 struct veth_priv *priv = netdev_priv(dev);
909 struct net_device *peer = rtnl_dereference(priv->peer);
910 int err;
911
912 if (!peer)
913 return -ENOTCONN;
914
915 if (priv->_xdp_prog) {
916 err = veth_enable_xdp(dev);
917 if (err)
918 return err;
919 }
920
921 if (peer->flags & IFF_UP) {
922 netif_carrier_on(dev);
923 netif_carrier_on(peer);
924 }
925
926 return 0;
927 }
928
929 static int veth_close(struct net_device *dev)
930 {
931 struct veth_priv *priv = netdev_priv(dev);
932 struct net_device *peer = rtnl_dereference(priv->peer);
933
934 netif_carrier_off(dev);
935 if (peer)
936 netif_carrier_off(peer);
937
938 if (priv->_xdp_prog)
939 veth_disable_xdp(dev);
940
941 return 0;
942 }
943
944 static int is_valid_veth_mtu(int mtu)
945 {
946 return mtu >= ETH_MIN_MTU && mtu <= ETH_MAX_MTU;
947 }
948
949 static int veth_alloc_queues(struct net_device *dev)
950 {
951 struct veth_priv *priv = netdev_priv(dev);
952 int i;
953
954 priv->rq = kcalloc(dev->num_rx_queues, sizeof(*priv->rq), GFP_KERNEL);
955 if (!priv->rq)
956 return -ENOMEM;
957
958 for (i = 0; i < dev->num_rx_queues; i++) {
959 priv->rq[i].dev = dev;
960 u64_stats_init(&priv->rq[i].stats.syncp);
961 }
962
963 return 0;
964 }
965
966 static void veth_free_queues(struct net_device *dev)
967 {
968 struct veth_priv *priv = netdev_priv(dev);
969
970 kfree(priv->rq);
971 }
972
973 static int veth_dev_init(struct net_device *dev)
974 {
975 int err;
976
977 dev->lstats = netdev_alloc_pcpu_stats(struct pcpu_lstats);
978 if (!dev->lstats)
979 return -ENOMEM;
980
981 err = veth_alloc_queues(dev);
982 if (err) {
983 free_percpu(dev->lstats);
984 return err;
985 }
986
987 return 0;
988 }
989
990 static void veth_dev_free(struct net_device *dev)
991 {
992 veth_free_queues(dev);
993 free_percpu(dev->lstats);
994 }
995
996 #ifdef CONFIG_NET_POLL_CONTROLLER
997 static void veth_poll_controller(struct net_device *dev)
998 {
999
1000
1001
1002
1003
1004
1005
1006
1007
1008 }
1009 #endif
1010
1011 static int veth_get_iflink(const struct net_device *dev)
1012 {
1013 struct veth_priv *priv = netdev_priv(dev);
1014 struct net_device *peer;
1015 int iflink;
1016
1017 rcu_read_lock();
1018 peer = rcu_dereference(priv->peer);
1019 iflink = peer ? peer->ifindex : 0;
1020 rcu_read_unlock();
1021
1022 return iflink;
1023 }
1024
1025 static netdev_features_t veth_fix_features(struct net_device *dev,
1026 netdev_features_t features)
1027 {
1028 struct veth_priv *priv = netdev_priv(dev);
1029 struct net_device *peer;
1030
1031 peer = rtnl_dereference(priv->peer);
1032 if (peer) {
1033 struct veth_priv *peer_priv = netdev_priv(peer);
1034
1035 if (peer_priv->_xdp_prog)
1036 features &= ~NETIF_F_GSO_SOFTWARE;
1037 }
1038
1039 return features;
1040 }
1041
1042 static void veth_set_rx_headroom(struct net_device *dev, int new_hr)
1043 {
1044 struct veth_priv *peer_priv, *priv = netdev_priv(dev);
1045 struct net_device *peer;
1046
1047 if (new_hr < 0)
1048 new_hr = 0;
1049
1050 rcu_read_lock();
1051 peer = rcu_dereference(priv->peer);
1052 if (unlikely(!peer))
1053 goto out;
1054
1055 peer_priv = netdev_priv(peer);
1056 priv->requested_headroom = new_hr;
1057 new_hr = max(priv->requested_headroom, peer_priv->requested_headroom);
1058 dev->needed_headroom = new_hr;
1059 peer->needed_headroom = new_hr;
1060
1061 out:
1062 rcu_read_unlock();
1063 }
1064
1065 static int veth_xdp_set(struct net_device *dev, struct bpf_prog *prog,
1066 struct netlink_ext_ack *extack)
1067 {
1068 struct veth_priv *priv = netdev_priv(dev);
1069 struct bpf_prog *old_prog;
1070 struct net_device *peer;
1071 unsigned int max_mtu;
1072 int err;
1073
1074 old_prog = priv->_xdp_prog;
1075 priv->_xdp_prog = prog;
1076 peer = rtnl_dereference(priv->peer);
1077
1078 if (prog) {
1079 if (!peer) {
1080 NL_SET_ERR_MSG_MOD(extack, "Cannot set XDP when peer is detached");
1081 err = -ENOTCONN;
1082 goto err;
1083 }
1084
1085 max_mtu = PAGE_SIZE - VETH_XDP_HEADROOM -
1086 peer->hard_header_len -
1087 SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
1088 if (peer->mtu > max_mtu) {
1089 NL_SET_ERR_MSG_MOD(extack, "Peer MTU is too large to set XDP");
1090 err = -ERANGE;
1091 goto err;
1092 }
1093
1094 if (dev->real_num_rx_queues < peer->real_num_tx_queues) {
1095 NL_SET_ERR_MSG_MOD(extack, "XDP expects number of rx queues not less than peer tx queues");
1096 err = -ENOSPC;
1097 goto err;
1098 }
1099
1100 if (dev->flags & IFF_UP) {
1101 err = veth_enable_xdp(dev);
1102 if (err) {
1103 NL_SET_ERR_MSG_MOD(extack, "Setup for XDP failed");
1104 goto err;
1105 }
1106 }
1107
1108 if (!old_prog) {
1109 peer->hw_features &= ~NETIF_F_GSO_SOFTWARE;
1110 peer->max_mtu = max_mtu;
1111 }
1112 }
1113
1114 if (old_prog) {
1115 if (!prog) {
1116 if (dev->flags & IFF_UP)
1117 veth_disable_xdp(dev);
1118
1119 if (peer) {
1120 peer->hw_features |= NETIF_F_GSO_SOFTWARE;
1121 peer->max_mtu = ETH_MAX_MTU;
1122 }
1123 }
1124 bpf_prog_put(old_prog);
1125 }
1126
1127 if ((!!old_prog ^ !!prog) && peer)
1128 netdev_update_features(peer);
1129
1130 return 0;
1131 err:
1132 priv->_xdp_prog = old_prog;
1133
1134 return err;
1135 }
1136
1137 static u32 veth_xdp_query(struct net_device *dev)
1138 {
1139 struct veth_priv *priv = netdev_priv(dev);
1140 const struct bpf_prog *xdp_prog;
1141
1142 xdp_prog = priv->_xdp_prog;
1143 if (xdp_prog)
1144 return xdp_prog->aux->id;
1145
1146 return 0;
1147 }
1148
1149 static int veth_xdp(struct net_device *dev, struct netdev_bpf *xdp)
1150 {
1151 switch (xdp->command) {
1152 case XDP_SETUP_PROG:
1153 return veth_xdp_set(dev, xdp->prog, xdp->extack);
1154 case XDP_QUERY_PROG:
1155 xdp->prog_id = veth_xdp_query(dev);
1156 return 0;
1157 default:
1158 return -EINVAL;
1159 }
1160 }
1161
1162 static const struct net_device_ops veth_netdev_ops = {
1163 .ndo_init = veth_dev_init,
1164 .ndo_open = veth_open,
1165 .ndo_stop = veth_close,
1166 .ndo_start_xmit = veth_xmit,
1167 .ndo_get_stats64 = veth_get_stats64,
1168 .ndo_set_rx_mode = veth_set_multicast_list,
1169 .ndo_set_mac_address = eth_mac_addr,
1170 #ifdef CONFIG_NET_POLL_CONTROLLER
1171 .ndo_poll_controller = veth_poll_controller,
1172 #endif
1173 .ndo_get_iflink = veth_get_iflink,
1174 .ndo_fix_features = veth_fix_features,
1175 .ndo_features_check = passthru_features_check,
1176 .ndo_set_rx_headroom = veth_set_rx_headroom,
1177 .ndo_bpf = veth_xdp,
1178 .ndo_xdp_xmit = veth_xdp_xmit,
1179 };
1180
1181 #define VETH_FEATURES (NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HW_CSUM | \
1182 NETIF_F_RXCSUM | NETIF_F_SCTP_CRC | NETIF_F_HIGHDMA | \
1183 NETIF_F_GSO_SOFTWARE | NETIF_F_GSO_ENCAP_ALL | \
1184 NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_CTAG_RX | \
1185 NETIF_F_HW_VLAN_STAG_TX | NETIF_F_HW_VLAN_STAG_RX )
1186
1187 static void veth_setup(struct net_device *dev)
1188 {
1189 ether_setup(dev);
1190
1191 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1192 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1193 dev->priv_flags |= IFF_NO_QUEUE;
1194 dev->priv_flags |= IFF_PHONY_HEADROOM;
1195
1196 dev->netdev_ops = &veth_netdev_ops;
1197 dev->ethtool_ops = &veth_ethtool_ops;
1198 dev->features |= NETIF_F_LLTX;
1199 dev->features |= VETH_FEATURES;
1200 dev->vlan_features = dev->features &
1201 ~(NETIF_F_HW_VLAN_CTAG_TX |
1202 NETIF_F_HW_VLAN_STAG_TX |
1203 NETIF_F_HW_VLAN_CTAG_RX |
1204 NETIF_F_HW_VLAN_STAG_RX);
1205 dev->needs_free_netdev = true;
1206 dev->priv_destructor = veth_dev_free;
1207 dev->max_mtu = ETH_MAX_MTU;
1208
1209 dev->hw_features = VETH_FEATURES;
1210 dev->hw_enc_features = VETH_FEATURES;
1211 dev->mpls_features = NETIF_F_HW_CSUM | NETIF_F_GSO_SOFTWARE;
1212 }
1213
1214
1215
1216
1217
1218 static int veth_validate(struct nlattr *tb[], struct nlattr *data[],
1219 struct netlink_ext_ack *extack)
1220 {
1221 if (tb[IFLA_ADDRESS]) {
1222 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1223 return -EINVAL;
1224 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1225 return -EADDRNOTAVAIL;
1226 }
1227 if (tb[IFLA_MTU]) {
1228 if (!is_valid_veth_mtu(nla_get_u32(tb[IFLA_MTU])))
1229 return -EINVAL;
1230 }
1231 return 0;
1232 }
1233
1234 static struct rtnl_link_ops veth_link_ops;
1235
1236 static int veth_newlink(struct net *src_net, struct net_device *dev,
1237 struct nlattr *tb[], struct nlattr *data[],
1238 struct netlink_ext_ack *extack)
1239 {
1240 int err;
1241 struct net_device *peer;
1242 struct veth_priv *priv;
1243 char ifname[IFNAMSIZ];
1244 struct nlattr *peer_tb[IFLA_MAX + 1], **tbp;
1245 unsigned char name_assign_type;
1246 struct ifinfomsg *ifmp;
1247 struct net *net;
1248
1249
1250
1251
1252 if (data != NULL && data[VETH_INFO_PEER] != NULL) {
1253 struct nlattr *nla_peer;
1254
1255 nla_peer = data[VETH_INFO_PEER];
1256 ifmp = nla_data(nla_peer);
1257 err = rtnl_nla_parse_ifla(peer_tb,
1258 nla_data(nla_peer) + sizeof(struct ifinfomsg),
1259 nla_len(nla_peer) - sizeof(struct ifinfomsg),
1260 NULL);
1261 if (err < 0)
1262 return err;
1263
1264 err = veth_validate(peer_tb, NULL, extack);
1265 if (err < 0)
1266 return err;
1267
1268 tbp = peer_tb;
1269 } else {
1270 ifmp = NULL;
1271 tbp = tb;
1272 }
1273
1274 if (ifmp && tbp[IFLA_IFNAME]) {
1275 nla_strlcpy(ifname, tbp[IFLA_IFNAME], IFNAMSIZ);
1276 name_assign_type = NET_NAME_USER;
1277 } else {
1278 snprintf(ifname, IFNAMSIZ, DRV_NAME "%%d");
1279 name_assign_type = NET_NAME_ENUM;
1280 }
1281
1282 net = rtnl_link_get_net(src_net, tbp);
1283 if (IS_ERR(net))
1284 return PTR_ERR(net);
1285
1286 peer = rtnl_create_link(net, ifname, name_assign_type,
1287 &veth_link_ops, tbp, extack);
1288 if (IS_ERR(peer)) {
1289 put_net(net);
1290 return PTR_ERR(peer);
1291 }
1292
1293 if (!ifmp || !tbp[IFLA_ADDRESS])
1294 eth_hw_addr_random(peer);
1295
1296 if (ifmp && (dev->ifindex != 0))
1297 peer->ifindex = ifmp->ifi_index;
1298
1299 peer->gso_max_size = dev->gso_max_size;
1300 peer->gso_max_segs = dev->gso_max_segs;
1301
1302 err = register_netdevice(peer);
1303 put_net(net);
1304 net = NULL;
1305 if (err < 0)
1306 goto err_register_peer;
1307
1308 netif_carrier_off(peer);
1309
1310 err = rtnl_configure_link(peer, ifmp);
1311 if (err < 0)
1312 goto err_configure_peer;
1313
1314
1315
1316
1317
1318
1319
1320
1321 if (tb[IFLA_ADDRESS] == NULL)
1322 eth_hw_addr_random(dev);
1323
1324 if (tb[IFLA_IFNAME])
1325 nla_strlcpy(dev->name, tb[IFLA_IFNAME], IFNAMSIZ);
1326 else
1327 snprintf(dev->name, IFNAMSIZ, DRV_NAME "%%d");
1328
1329 err = register_netdevice(dev);
1330 if (err < 0)
1331 goto err_register_dev;
1332
1333 netif_carrier_off(dev);
1334
1335
1336
1337
1338
1339 priv = netdev_priv(dev);
1340 rcu_assign_pointer(priv->peer, peer);
1341
1342 priv = netdev_priv(peer);
1343 rcu_assign_pointer(priv->peer, dev);
1344
1345 return 0;
1346
1347 err_register_dev:
1348
1349 err_configure_peer:
1350 unregister_netdevice(peer);
1351 return err;
1352
1353 err_register_peer:
1354 free_netdev(peer);
1355 return err;
1356 }
1357
1358 static void veth_dellink(struct net_device *dev, struct list_head *head)
1359 {
1360 struct veth_priv *priv;
1361 struct net_device *peer;
1362
1363 priv = netdev_priv(dev);
1364 peer = rtnl_dereference(priv->peer);
1365
1366
1367
1368
1369
1370 RCU_INIT_POINTER(priv->peer, NULL);
1371 unregister_netdevice_queue(dev, head);
1372
1373 if (peer) {
1374 priv = netdev_priv(peer);
1375 RCU_INIT_POINTER(priv->peer, NULL);
1376 unregister_netdevice_queue(peer, head);
1377 }
1378 }
1379
1380 static const struct nla_policy veth_policy[VETH_INFO_MAX + 1] = {
1381 [VETH_INFO_PEER] = { .len = sizeof(struct ifinfomsg) },
1382 };
1383
1384 static struct net *veth_get_link_net(const struct net_device *dev)
1385 {
1386 struct veth_priv *priv = netdev_priv(dev);
1387 struct net_device *peer = rtnl_dereference(priv->peer);
1388
1389 return peer ? dev_net(peer) : dev_net(dev);
1390 }
1391
1392 static struct rtnl_link_ops veth_link_ops = {
1393 .kind = DRV_NAME,
1394 .priv_size = sizeof(struct veth_priv),
1395 .setup = veth_setup,
1396 .validate = veth_validate,
1397 .newlink = veth_newlink,
1398 .dellink = veth_dellink,
1399 .policy = veth_policy,
1400 .maxtype = VETH_INFO_MAX,
1401 .get_link_net = veth_get_link_net,
1402 };
1403
1404
1405
1406
1407
1408 static __init int veth_init(void)
1409 {
1410 return rtnl_link_register(&veth_link_ops);
1411 }
1412
1413 static __exit void veth_exit(void)
1414 {
1415 rtnl_link_unregister(&veth_link_ops);
1416 }
1417
1418 module_init(veth_init);
1419 module_exit(veth_exit);
1420
1421 MODULE_DESCRIPTION("Virtual Ethernet Tunnel");
1422 MODULE_LICENSE("GPL v2");
1423 MODULE_ALIAS_RTNL_LINK(DRV_NAME);