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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#define VETH_XDP_TX_BULK_SIZE 16
42
43struct veth_rq_stats {
44 u64 xdp_packets;
45 u64 xdp_bytes;
46 u64 xdp_drops;
47 struct u64_stats_sync syncp;
48};
49
50struct 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
61struct 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
69struct veth_xdp_tx_bq {
70 struct xdp_frame *q[VETH_XDP_TX_BULK_SIZE];
71 unsigned int count;
72};
73
74/*
75 * ethtool interface
76 */
77
78struct 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
85static 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
93static struct {
94 const char string[ETH_GSTRING_LEN];
95} ethtool_stats_keys[] = {
96 { "peer_ifindex" },
97};
98
99static 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
109static 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
115static 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
136static 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
147static 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
173static 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/* general routines */
184
185static bool veth_is_xdp_frame(void *ptr)
186{
187 return (unsigned long)ptr & VETH_XDP_FLAG;
188}
189
190static void *veth_ptr_to_xdp(void *ptr)
191{
192 return (void *)((unsigned long)ptr & ~VETH_XDP_FLAG);
193}
194
195static void *veth_xdp_to_ptr(void *ptr)
196{
197 return (void *)((unsigned long)ptr | VETH_XDP_FLAG);
198}
199
200static 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
208static void __veth_xdp_flush(struct veth_rq *rq)
209{
210 /* Write ptr_ring before reading rx_notify_masked */
211 smp_mb();
212 if (!rq->rx_notify_masked) {
213 rq->rx_notify_masked = true;
214 napi_schedule(&rq->xdp_napi);
215 }
216}
217
218static 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
228static 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
236static 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 {
272drop:
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
284static 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
307static 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
332static 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/* fake multicast ability */
364static void veth_set_multicast_list(struct net_device *dev)
365{
366}
367
368static 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
387static int veth_select_rxq(struct net_device *dev)
388{
389 return smp_processor_id() % dev->real_num_rx_queues;
390}
391
392static 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 /* Non-NULL xdp_prog ensures that xdp_ring is initialized on receive
415 * side. This means an XDP program is loaded on the peer and the peer
416 * device is up.
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;
446drop:
447 atomic64_add(drops, &priv->dropped);
448
449 return ret;
450}
451
452static 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
468static 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 /* xdp_ring is initialized on receive side? */
483 if (unlikely(!rcu_access_pointer(rq->xdp_prog)))
484 goto out;
485
486 __veth_xdp_flush(rq);
487out:
488 rcu_read_unlock();
489}
490
491static 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
507static 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 /* fall through */
565 case XDP_ABORTED:
566 trace_xdp_exception(rq->dev, xdp_prog, act);
567 /* fall through */
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);
584err:
585 return skb;
586err_xdp:
587 rcu_read_unlock();
588 xdp_return_frame(frame);
589xdp_xmit:
590 return NULL;
591}
592
593static 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 /* fall through */
690 case XDP_ABORTED:
691 trace_xdp_exception(rq->dev, xdp_prog, act);
692 /* fall through */
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);
713out:
714 return skb;
715drop:
716 rcu_read_unlock();
717 kfree_skb(skb);
718 return NULL;
719err_xdp:
720 rcu_read_unlock();
721 page_frag_free(xdp.data);
722xdp_xmit:
723 return NULL;
724}
725
726static 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
768static 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 /* Write rx_notify_masked before reading ptr_ring */
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
799static 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;
820err_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
827static 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
849static 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 /* Save original mem info as it can be overwritten */
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;
881err_reg_mem:
882 xdp_rxq_info_unreg(&priv->rq[i].xdp_rxq);
883err_rxq_reg:
884 for (i--; i >= 0; i--)
885 xdp_rxq_info_unreg(&priv->rq[i].xdp_rxq);
886
887 return err;
888}
889
890static 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
906static 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
929static 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
944static int is_valid_veth_mtu(int mtu)
945{
946 return mtu >= ETH_MIN_MTU && mtu <= ETH_MAX_MTU;
947}
948
949static 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
966static void veth_free_queues(struct net_device *dev)
967{
968 struct veth_priv *priv = netdev_priv(dev);
969
970 kfree(priv->rq);
971}
972
973static 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
990static 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
997static void veth_poll_controller(struct net_device *dev)
998{
999 /* veth only receives frames when its peer sends one
1000 * Since it has nothing to do with disabling irqs, we are guaranteed
1001 * never to have pending data when we poll for it so
1002 * there is nothing to do here.
1003 *
1004 * We need this though so netpoll recognizes us as an interface that
1005 * supports polling, which enables bridge devices in virt setups to
1006 * still use netconsole
1007 */
1008}
1009#endif /* CONFIG_NET_POLL_CONTROLLER */
1010
1011static 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
1025static 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
1042static 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
1061out:
1062 rcu_read_unlock();
1063}
1064
1065static 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;
1131err:
1132 priv->_xdp_prog = old_prog;
1133
1134 return err;
1135}
1136
1137static 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
1149static 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
1162static 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
1187static 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 * netlink interface
1216 */
1217
1218static 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
1234static struct rtnl_link_ops veth_link_ops;
1235
1236static 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 * create and register peer first
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 * register dev last
1316 *
1317 * note, that since we've registered new device the dev's name
1318 * should be re-allocated
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 * tie the deviced together
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
1347err_register_dev:
1348 /* nothing to do */
1349err_configure_peer:
1350 unregister_netdevice(peer);
1351 return err;
1352
1353err_register_peer:
1354 free_netdev(peer);
1355 return err;
1356}
1357
1358static 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 /* Note : dellink() is called from default_device_exit_batch(),
1367 * before a rcu_synchronize() point. The devices are guaranteed
1368 * not being freed before one RCU grace period.
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
1380static const struct nla_policy veth_policy[VETH_INFO_MAX + 1] = {
1381 [VETH_INFO_PEER] = { .len = sizeof(struct ifinfomsg) },
1382};
1383
1384static 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
1392static 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 * init/fini
1406 */
1407
1408static __init int veth_init(void)
1409{
1410 return rtnl_link_register(&veth_link_ops);
1411}
1412
1413static __exit void veth_exit(void)
1414{
1415 rtnl_link_unregister(&veth_link_ops);
1416}
1417
1418module_init(veth_init);
1419module_exit(veth_exit);
1420
1421MODULE_DESCRIPTION("Virtual Ethernet Tunnel");
1422MODULE_LICENSE("GPL v2");
1423MODULE_ALIAS_RTNL_LINK(DRV_NAME);
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#define VETH_XDP_TX_BULK_SIZE 16
38#define VETH_XDP_BATCH 16
39
40struct veth_stats {
41 u64 rx_drops;
42 /* xdp */
43 u64 xdp_packets;
44 u64 xdp_bytes;
45 u64 xdp_redirect;
46 u64 xdp_drops;
47 u64 xdp_tx;
48 u64 xdp_tx_err;
49 u64 peer_tq_xdp_xmit;
50 u64 peer_tq_xdp_xmit_err;
51};
52
53struct veth_rq_stats {
54 struct veth_stats vs;
55 struct u64_stats_sync syncp;
56};
57
58struct veth_rq {
59 struct napi_struct xdp_napi;
60 struct napi_struct __rcu *napi; /* points to xdp_napi when the latter is initialized */
61 struct net_device *dev;
62 struct bpf_prog __rcu *xdp_prog;
63 struct xdp_mem_info xdp_mem;
64 struct veth_rq_stats stats;
65 bool rx_notify_masked;
66 struct ptr_ring xdp_ring;
67 struct xdp_rxq_info xdp_rxq;
68};
69
70struct veth_priv {
71 struct net_device __rcu *peer;
72 atomic64_t dropped;
73 struct bpf_prog *_xdp_prog;
74 struct veth_rq *rq;
75 unsigned int requested_headroom;
76};
77
78struct veth_xdp_tx_bq {
79 struct xdp_frame *q[VETH_XDP_TX_BULK_SIZE];
80 unsigned int count;
81};
82
83/*
84 * ethtool interface
85 */
86
87struct veth_q_stat_desc {
88 char desc[ETH_GSTRING_LEN];
89 size_t offset;
90};
91
92#define VETH_RQ_STAT(m) offsetof(struct veth_stats, m)
93
94static const struct veth_q_stat_desc veth_rq_stats_desc[] = {
95 { "xdp_packets", VETH_RQ_STAT(xdp_packets) },
96 { "xdp_bytes", VETH_RQ_STAT(xdp_bytes) },
97 { "drops", VETH_RQ_STAT(rx_drops) },
98 { "xdp_redirect", VETH_RQ_STAT(xdp_redirect) },
99 { "xdp_drops", VETH_RQ_STAT(xdp_drops) },
100 { "xdp_tx", VETH_RQ_STAT(xdp_tx) },
101 { "xdp_tx_errors", VETH_RQ_STAT(xdp_tx_err) },
102};
103
104#define VETH_RQ_STATS_LEN ARRAY_SIZE(veth_rq_stats_desc)
105
106static const struct veth_q_stat_desc veth_tq_stats_desc[] = {
107 { "xdp_xmit", VETH_RQ_STAT(peer_tq_xdp_xmit) },
108 { "xdp_xmit_errors", VETH_RQ_STAT(peer_tq_xdp_xmit_err) },
109};
110
111#define VETH_TQ_STATS_LEN ARRAY_SIZE(veth_tq_stats_desc)
112
113static struct {
114 const char string[ETH_GSTRING_LEN];
115} ethtool_stats_keys[] = {
116 { "peer_ifindex" },
117};
118
119static int veth_get_link_ksettings(struct net_device *dev,
120 struct ethtool_link_ksettings *cmd)
121{
122 cmd->base.speed = SPEED_10000;
123 cmd->base.duplex = DUPLEX_FULL;
124 cmd->base.port = PORT_TP;
125 cmd->base.autoneg = AUTONEG_DISABLE;
126 return 0;
127}
128
129static void veth_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
130{
131 strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
132 strlcpy(info->version, DRV_VERSION, sizeof(info->version));
133}
134
135static void veth_get_strings(struct net_device *dev, u32 stringset, u8 *buf)
136{
137 char *p = (char *)buf;
138 int i, j;
139
140 switch(stringset) {
141 case ETH_SS_STATS:
142 memcpy(p, ðtool_stats_keys, sizeof(ethtool_stats_keys));
143 p += sizeof(ethtool_stats_keys);
144 for (i = 0; i < dev->real_num_rx_queues; i++) {
145 for (j = 0; j < VETH_RQ_STATS_LEN; j++) {
146 snprintf(p, ETH_GSTRING_LEN,
147 "rx_queue_%u_%.18s",
148 i, veth_rq_stats_desc[j].desc);
149 p += ETH_GSTRING_LEN;
150 }
151 }
152 for (i = 0; i < dev->real_num_tx_queues; i++) {
153 for (j = 0; j < VETH_TQ_STATS_LEN; j++) {
154 snprintf(p, ETH_GSTRING_LEN,
155 "tx_queue_%u_%.18s",
156 i, veth_tq_stats_desc[j].desc);
157 p += ETH_GSTRING_LEN;
158 }
159 }
160 break;
161 }
162}
163
164static int veth_get_sset_count(struct net_device *dev, int sset)
165{
166 switch (sset) {
167 case ETH_SS_STATS:
168 return ARRAY_SIZE(ethtool_stats_keys) +
169 VETH_RQ_STATS_LEN * dev->real_num_rx_queues +
170 VETH_TQ_STATS_LEN * dev->real_num_tx_queues;
171 default:
172 return -EOPNOTSUPP;
173 }
174}
175
176static void veth_get_ethtool_stats(struct net_device *dev,
177 struct ethtool_stats *stats, u64 *data)
178{
179 struct veth_priv *rcv_priv, *priv = netdev_priv(dev);
180 struct net_device *peer = rtnl_dereference(priv->peer);
181 int i, j, idx;
182
183 data[0] = peer ? peer->ifindex : 0;
184 idx = 1;
185 for (i = 0; i < dev->real_num_rx_queues; i++) {
186 const struct veth_rq_stats *rq_stats = &priv->rq[i].stats;
187 const void *stats_base = (void *)&rq_stats->vs;
188 unsigned int start;
189 size_t offset;
190
191 do {
192 start = u64_stats_fetch_begin_irq(&rq_stats->syncp);
193 for (j = 0; j < VETH_RQ_STATS_LEN; j++) {
194 offset = veth_rq_stats_desc[j].offset;
195 data[idx + j] = *(u64 *)(stats_base + offset);
196 }
197 } while (u64_stats_fetch_retry_irq(&rq_stats->syncp, start));
198 idx += VETH_RQ_STATS_LEN;
199 }
200
201 if (!peer)
202 return;
203
204 rcv_priv = netdev_priv(peer);
205 for (i = 0; i < peer->real_num_rx_queues; i++) {
206 const struct veth_rq_stats *rq_stats = &rcv_priv->rq[i].stats;
207 const void *base = (void *)&rq_stats->vs;
208 unsigned int start, tx_idx = idx;
209 size_t offset;
210
211 tx_idx += (i % dev->real_num_tx_queues) * VETH_TQ_STATS_LEN;
212 do {
213 start = u64_stats_fetch_begin_irq(&rq_stats->syncp);
214 for (j = 0; j < VETH_TQ_STATS_LEN; j++) {
215 offset = veth_tq_stats_desc[j].offset;
216 data[tx_idx + j] += *(u64 *)(base + offset);
217 }
218 } while (u64_stats_fetch_retry_irq(&rq_stats->syncp, start));
219 }
220}
221
222static void veth_get_channels(struct net_device *dev,
223 struct ethtool_channels *channels)
224{
225 channels->tx_count = dev->real_num_tx_queues;
226 channels->rx_count = dev->real_num_rx_queues;
227 channels->max_tx = dev->real_num_tx_queues;
228 channels->max_rx = dev->real_num_rx_queues;
229 channels->combined_count = min(dev->real_num_rx_queues, dev->real_num_tx_queues);
230 channels->max_combined = min(dev->real_num_rx_queues, dev->real_num_tx_queues);
231}
232
233static const struct ethtool_ops veth_ethtool_ops = {
234 .get_drvinfo = veth_get_drvinfo,
235 .get_link = ethtool_op_get_link,
236 .get_strings = veth_get_strings,
237 .get_sset_count = veth_get_sset_count,
238 .get_ethtool_stats = veth_get_ethtool_stats,
239 .get_link_ksettings = veth_get_link_ksettings,
240 .get_ts_info = ethtool_op_get_ts_info,
241 .get_channels = veth_get_channels,
242};
243
244/* general routines */
245
246static bool veth_is_xdp_frame(void *ptr)
247{
248 return (unsigned long)ptr & VETH_XDP_FLAG;
249}
250
251static struct xdp_frame *veth_ptr_to_xdp(void *ptr)
252{
253 return (void *)((unsigned long)ptr & ~VETH_XDP_FLAG);
254}
255
256static void *veth_xdp_to_ptr(struct xdp_frame *xdp)
257{
258 return (void *)((unsigned long)xdp | VETH_XDP_FLAG);
259}
260
261static void veth_ptr_free(void *ptr)
262{
263 if (veth_is_xdp_frame(ptr))
264 xdp_return_frame(veth_ptr_to_xdp(ptr));
265 else
266 kfree_skb(ptr);
267}
268
269static void __veth_xdp_flush(struct veth_rq *rq)
270{
271 /* Write ptr_ring before reading rx_notify_masked */
272 smp_mb();
273 if (!rq->rx_notify_masked) {
274 rq->rx_notify_masked = true;
275 napi_schedule(&rq->xdp_napi);
276 }
277}
278
279static int veth_xdp_rx(struct veth_rq *rq, struct sk_buff *skb)
280{
281 if (unlikely(ptr_ring_produce(&rq->xdp_ring, skb))) {
282 dev_kfree_skb_any(skb);
283 return NET_RX_DROP;
284 }
285
286 return NET_RX_SUCCESS;
287}
288
289static int veth_forward_skb(struct net_device *dev, struct sk_buff *skb,
290 struct veth_rq *rq, bool xdp)
291{
292 return __dev_forward_skb(dev, skb) ?: xdp ?
293 veth_xdp_rx(rq, skb) :
294 netif_rx(skb);
295}
296
297/* return true if the specified skb has chances of GRO aggregation
298 * Don't strive for accuracy, but try to avoid GRO overhead in the most
299 * common scenarios.
300 * When XDP is enabled, all traffic is considered eligible, as the xmit
301 * device has TSO off.
302 * When TSO is enabled on the xmit device, we are likely interested only
303 * in UDP aggregation, explicitly check for that if the skb is suspected
304 * - the sock_wfree destructor is used by UDP, ICMP and XDP sockets -
305 * to belong to locally generated UDP traffic.
306 */
307static bool veth_skb_is_eligible_for_gro(const struct net_device *dev,
308 const struct net_device *rcv,
309 const struct sk_buff *skb)
310{
311 return !(dev->features & NETIF_F_ALL_TSO) ||
312 (skb->destructor == sock_wfree &&
313 rcv->features & (NETIF_F_GRO_FRAGLIST | NETIF_F_GRO_UDP_FWD));
314}
315
316static netdev_tx_t veth_xmit(struct sk_buff *skb, struct net_device *dev)
317{
318 struct veth_priv *rcv_priv, *priv = netdev_priv(dev);
319 struct veth_rq *rq = NULL;
320 struct net_device *rcv;
321 int length = skb->len;
322 bool use_napi = false;
323 int rxq;
324
325 rcu_read_lock();
326 rcv = rcu_dereference(priv->peer);
327 if (unlikely(!rcv)) {
328 kfree_skb(skb);
329 goto drop;
330 }
331
332 rcv_priv = netdev_priv(rcv);
333 rxq = skb_get_queue_mapping(skb);
334 if (rxq < rcv->real_num_rx_queues) {
335 rq = &rcv_priv->rq[rxq];
336
337 /* The napi pointer is available when an XDP program is
338 * attached or when GRO is enabled
339 * Don't bother with napi/GRO if the skb can't be aggregated
340 */
341 use_napi = rcu_access_pointer(rq->napi) &&
342 veth_skb_is_eligible_for_gro(dev, rcv, skb);
343 skb_record_rx_queue(skb, rxq);
344 }
345
346 skb_tx_timestamp(skb);
347 if (likely(veth_forward_skb(rcv, skb, rq, use_napi) == NET_RX_SUCCESS)) {
348 if (!use_napi)
349 dev_lstats_add(dev, length);
350 } else {
351drop:
352 atomic64_inc(&priv->dropped);
353 }
354
355 if (use_napi)
356 __veth_xdp_flush(rq);
357
358 rcu_read_unlock();
359
360 return NETDEV_TX_OK;
361}
362
363static u64 veth_stats_tx(struct net_device *dev, u64 *packets, u64 *bytes)
364{
365 struct veth_priv *priv = netdev_priv(dev);
366
367 dev_lstats_read(dev, packets, bytes);
368 return atomic64_read(&priv->dropped);
369}
370
371static void veth_stats_rx(struct veth_stats *result, struct net_device *dev)
372{
373 struct veth_priv *priv = netdev_priv(dev);
374 int i;
375
376 result->peer_tq_xdp_xmit_err = 0;
377 result->xdp_packets = 0;
378 result->xdp_tx_err = 0;
379 result->xdp_bytes = 0;
380 result->rx_drops = 0;
381 for (i = 0; i < dev->num_rx_queues; i++) {
382 u64 packets, bytes, drops, xdp_tx_err, peer_tq_xdp_xmit_err;
383 struct veth_rq_stats *stats = &priv->rq[i].stats;
384 unsigned int start;
385
386 do {
387 start = u64_stats_fetch_begin_irq(&stats->syncp);
388 peer_tq_xdp_xmit_err = stats->vs.peer_tq_xdp_xmit_err;
389 xdp_tx_err = stats->vs.xdp_tx_err;
390 packets = stats->vs.xdp_packets;
391 bytes = stats->vs.xdp_bytes;
392 drops = stats->vs.rx_drops;
393 } while (u64_stats_fetch_retry_irq(&stats->syncp, start));
394 result->peer_tq_xdp_xmit_err += peer_tq_xdp_xmit_err;
395 result->xdp_tx_err += xdp_tx_err;
396 result->xdp_packets += packets;
397 result->xdp_bytes += bytes;
398 result->rx_drops += drops;
399 }
400}
401
402static void veth_get_stats64(struct net_device *dev,
403 struct rtnl_link_stats64 *tot)
404{
405 struct veth_priv *priv = netdev_priv(dev);
406 struct net_device *peer;
407 struct veth_stats rx;
408 u64 packets, bytes;
409
410 tot->tx_dropped = veth_stats_tx(dev, &packets, &bytes);
411 tot->tx_bytes = bytes;
412 tot->tx_packets = packets;
413
414 veth_stats_rx(&rx, dev);
415 tot->tx_dropped += rx.xdp_tx_err;
416 tot->rx_dropped = rx.rx_drops + rx.peer_tq_xdp_xmit_err;
417 tot->rx_bytes = rx.xdp_bytes;
418 tot->rx_packets = rx.xdp_packets;
419
420 rcu_read_lock();
421 peer = rcu_dereference(priv->peer);
422 if (peer) {
423 veth_stats_tx(peer, &packets, &bytes);
424 tot->rx_bytes += bytes;
425 tot->rx_packets += packets;
426
427 veth_stats_rx(&rx, peer);
428 tot->tx_dropped += rx.peer_tq_xdp_xmit_err;
429 tot->rx_dropped += rx.xdp_tx_err;
430 tot->tx_bytes += rx.xdp_bytes;
431 tot->tx_packets += rx.xdp_packets;
432 }
433 rcu_read_unlock();
434}
435
436/* fake multicast ability */
437static void veth_set_multicast_list(struct net_device *dev)
438{
439}
440
441static struct sk_buff *veth_build_skb(void *head, int headroom, int len,
442 int buflen)
443{
444 struct sk_buff *skb;
445
446 skb = build_skb(head, buflen);
447 if (!skb)
448 return NULL;
449
450 skb_reserve(skb, headroom);
451 skb_put(skb, len);
452
453 return skb;
454}
455
456static int veth_select_rxq(struct net_device *dev)
457{
458 return smp_processor_id() % dev->real_num_rx_queues;
459}
460
461static struct net_device *veth_peer_dev(struct net_device *dev)
462{
463 struct veth_priv *priv = netdev_priv(dev);
464
465 /* Callers must be under RCU read side. */
466 return rcu_dereference(priv->peer);
467}
468
469static int veth_xdp_xmit(struct net_device *dev, int n,
470 struct xdp_frame **frames,
471 u32 flags, bool ndo_xmit)
472{
473 struct veth_priv *rcv_priv, *priv = netdev_priv(dev);
474 int i, ret = -ENXIO, nxmit = 0;
475 struct net_device *rcv;
476 unsigned int max_len;
477 struct veth_rq *rq;
478
479 if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK))
480 return -EINVAL;
481
482 rcu_read_lock();
483 rcv = rcu_dereference(priv->peer);
484 if (unlikely(!rcv))
485 goto out;
486
487 rcv_priv = netdev_priv(rcv);
488 rq = &rcv_priv->rq[veth_select_rxq(rcv)];
489 /* The napi pointer is set if NAPI is enabled, which ensures that
490 * xdp_ring is initialized on receive side and the peer device is up.
491 */
492 if (!rcu_access_pointer(rq->napi))
493 goto out;
494
495 max_len = rcv->mtu + rcv->hard_header_len + VLAN_HLEN;
496
497 spin_lock(&rq->xdp_ring.producer_lock);
498 for (i = 0; i < n; i++) {
499 struct xdp_frame *frame = frames[i];
500 void *ptr = veth_xdp_to_ptr(frame);
501
502 if (unlikely(frame->len > max_len ||
503 __ptr_ring_produce(&rq->xdp_ring, ptr)))
504 break;
505 nxmit++;
506 }
507 spin_unlock(&rq->xdp_ring.producer_lock);
508
509 if (flags & XDP_XMIT_FLUSH)
510 __veth_xdp_flush(rq);
511
512 ret = nxmit;
513 if (ndo_xmit) {
514 u64_stats_update_begin(&rq->stats.syncp);
515 rq->stats.vs.peer_tq_xdp_xmit += nxmit;
516 rq->stats.vs.peer_tq_xdp_xmit_err += n - nxmit;
517 u64_stats_update_end(&rq->stats.syncp);
518 }
519
520out:
521 rcu_read_unlock();
522
523 return ret;
524}
525
526static int veth_ndo_xdp_xmit(struct net_device *dev, int n,
527 struct xdp_frame **frames, u32 flags)
528{
529 int err;
530
531 err = veth_xdp_xmit(dev, n, frames, flags, true);
532 if (err < 0) {
533 struct veth_priv *priv = netdev_priv(dev);
534
535 atomic64_add(n, &priv->dropped);
536 }
537
538 return err;
539}
540
541static void veth_xdp_flush_bq(struct veth_rq *rq, struct veth_xdp_tx_bq *bq)
542{
543 int sent, i, err = 0, drops;
544
545 sent = veth_xdp_xmit(rq->dev, bq->count, bq->q, 0, false);
546 if (sent < 0) {
547 err = sent;
548 sent = 0;
549 }
550
551 for (i = sent; unlikely(i < bq->count); i++)
552 xdp_return_frame(bq->q[i]);
553
554 drops = bq->count - sent;
555 trace_xdp_bulk_tx(rq->dev, sent, drops, err);
556
557 u64_stats_update_begin(&rq->stats.syncp);
558 rq->stats.vs.xdp_tx += sent;
559 rq->stats.vs.xdp_tx_err += drops;
560 u64_stats_update_end(&rq->stats.syncp);
561
562 bq->count = 0;
563}
564
565static void veth_xdp_flush(struct veth_rq *rq, struct veth_xdp_tx_bq *bq)
566{
567 struct veth_priv *rcv_priv, *priv = netdev_priv(rq->dev);
568 struct net_device *rcv;
569 struct veth_rq *rcv_rq;
570
571 rcu_read_lock();
572 veth_xdp_flush_bq(rq, bq);
573 rcv = rcu_dereference(priv->peer);
574 if (unlikely(!rcv))
575 goto out;
576
577 rcv_priv = netdev_priv(rcv);
578 rcv_rq = &rcv_priv->rq[veth_select_rxq(rcv)];
579 /* xdp_ring is initialized on receive side? */
580 if (unlikely(!rcu_access_pointer(rcv_rq->xdp_prog)))
581 goto out;
582
583 __veth_xdp_flush(rcv_rq);
584out:
585 rcu_read_unlock();
586}
587
588static int veth_xdp_tx(struct veth_rq *rq, struct xdp_buff *xdp,
589 struct veth_xdp_tx_bq *bq)
590{
591 struct xdp_frame *frame = xdp_convert_buff_to_frame(xdp);
592
593 if (unlikely(!frame))
594 return -EOVERFLOW;
595
596 if (unlikely(bq->count == VETH_XDP_TX_BULK_SIZE))
597 veth_xdp_flush_bq(rq, bq);
598
599 bq->q[bq->count++] = frame;
600
601 return 0;
602}
603
604static struct xdp_frame *veth_xdp_rcv_one(struct veth_rq *rq,
605 struct xdp_frame *frame,
606 struct veth_xdp_tx_bq *bq,
607 struct veth_stats *stats)
608{
609 struct xdp_frame orig_frame;
610 struct bpf_prog *xdp_prog;
611
612 rcu_read_lock();
613 xdp_prog = rcu_dereference(rq->xdp_prog);
614 if (likely(xdp_prog)) {
615 struct xdp_buff xdp;
616 u32 act;
617
618 xdp_convert_frame_to_buff(frame, &xdp);
619 xdp.rxq = &rq->xdp_rxq;
620
621 act = bpf_prog_run_xdp(xdp_prog, &xdp);
622
623 switch (act) {
624 case XDP_PASS:
625 if (xdp_update_frame_from_buff(&xdp, frame))
626 goto err_xdp;
627 break;
628 case XDP_TX:
629 orig_frame = *frame;
630 xdp.rxq->mem = frame->mem;
631 if (unlikely(veth_xdp_tx(rq, &xdp, bq) < 0)) {
632 trace_xdp_exception(rq->dev, xdp_prog, act);
633 frame = &orig_frame;
634 stats->rx_drops++;
635 goto err_xdp;
636 }
637 stats->xdp_tx++;
638 rcu_read_unlock();
639 goto xdp_xmit;
640 case XDP_REDIRECT:
641 orig_frame = *frame;
642 xdp.rxq->mem = frame->mem;
643 if (xdp_do_redirect(rq->dev, &xdp, xdp_prog)) {
644 frame = &orig_frame;
645 stats->rx_drops++;
646 goto err_xdp;
647 }
648 stats->xdp_redirect++;
649 rcu_read_unlock();
650 goto xdp_xmit;
651 default:
652 bpf_warn_invalid_xdp_action(act);
653 fallthrough;
654 case XDP_ABORTED:
655 trace_xdp_exception(rq->dev, xdp_prog, act);
656 fallthrough;
657 case XDP_DROP:
658 stats->xdp_drops++;
659 goto err_xdp;
660 }
661 }
662 rcu_read_unlock();
663
664 return frame;
665err_xdp:
666 rcu_read_unlock();
667 xdp_return_frame(frame);
668xdp_xmit:
669 return NULL;
670}
671
672/* frames array contains VETH_XDP_BATCH at most */
673static void veth_xdp_rcv_bulk_skb(struct veth_rq *rq, void **frames,
674 int n_xdpf, struct veth_xdp_tx_bq *bq,
675 struct veth_stats *stats)
676{
677 void *skbs[VETH_XDP_BATCH];
678 int i;
679
680 if (xdp_alloc_skb_bulk(skbs, n_xdpf,
681 GFP_ATOMIC | __GFP_ZERO) < 0) {
682 for (i = 0; i < n_xdpf; i++)
683 xdp_return_frame(frames[i]);
684 stats->rx_drops += n_xdpf;
685
686 return;
687 }
688
689 for (i = 0; i < n_xdpf; i++) {
690 struct sk_buff *skb = skbs[i];
691
692 skb = __xdp_build_skb_from_frame(frames[i], skb,
693 rq->dev);
694 if (!skb) {
695 xdp_return_frame(frames[i]);
696 stats->rx_drops++;
697 continue;
698 }
699 napi_gro_receive(&rq->xdp_napi, skb);
700 }
701}
702
703static struct sk_buff *veth_xdp_rcv_skb(struct veth_rq *rq,
704 struct sk_buff *skb,
705 struct veth_xdp_tx_bq *bq,
706 struct veth_stats *stats)
707{
708 u32 pktlen, headroom, act, metalen, frame_sz;
709 void *orig_data, *orig_data_end;
710 struct bpf_prog *xdp_prog;
711 int mac_len, delta, off;
712 struct xdp_buff xdp;
713
714 skb_orphan_partial(skb);
715
716 rcu_read_lock();
717 xdp_prog = rcu_dereference(rq->xdp_prog);
718 if (unlikely(!xdp_prog)) {
719 rcu_read_unlock();
720 goto out;
721 }
722
723 mac_len = skb->data - skb_mac_header(skb);
724 pktlen = skb->len + mac_len;
725 headroom = skb_headroom(skb) - mac_len;
726
727 if (skb_shared(skb) || skb_head_is_locked(skb) ||
728 skb_is_nonlinear(skb) || headroom < XDP_PACKET_HEADROOM) {
729 struct sk_buff *nskb;
730 int size, head_off;
731 void *head, *start;
732 struct page *page;
733
734 size = SKB_DATA_ALIGN(VETH_XDP_HEADROOM + pktlen) +
735 SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
736 if (size > PAGE_SIZE)
737 goto drop;
738
739 page = alloc_page(GFP_ATOMIC | __GFP_NOWARN);
740 if (!page)
741 goto drop;
742
743 head = page_address(page);
744 start = head + VETH_XDP_HEADROOM;
745 if (skb_copy_bits(skb, -mac_len, start, pktlen)) {
746 page_frag_free(head);
747 goto drop;
748 }
749
750 nskb = veth_build_skb(head, VETH_XDP_HEADROOM + mac_len,
751 skb->len, PAGE_SIZE);
752 if (!nskb) {
753 page_frag_free(head);
754 goto drop;
755 }
756
757 skb_copy_header(nskb, skb);
758 head_off = skb_headroom(nskb) - skb_headroom(skb);
759 skb_headers_offset_update(nskb, head_off);
760 consume_skb(skb);
761 skb = nskb;
762 }
763
764 /* SKB "head" area always have tailroom for skb_shared_info */
765 frame_sz = skb_end_pointer(skb) - skb->head;
766 frame_sz += SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
767 xdp_init_buff(&xdp, frame_sz, &rq->xdp_rxq);
768 xdp_prepare_buff(&xdp, skb->head, skb->mac_header, pktlen, true);
769
770 orig_data = xdp.data;
771 orig_data_end = xdp.data_end;
772
773 act = bpf_prog_run_xdp(xdp_prog, &xdp);
774
775 switch (act) {
776 case XDP_PASS:
777 break;
778 case XDP_TX:
779 get_page(virt_to_page(xdp.data));
780 consume_skb(skb);
781 xdp.rxq->mem = rq->xdp_mem;
782 if (unlikely(veth_xdp_tx(rq, &xdp, bq) < 0)) {
783 trace_xdp_exception(rq->dev, xdp_prog, act);
784 stats->rx_drops++;
785 goto err_xdp;
786 }
787 stats->xdp_tx++;
788 rcu_read_unlock();
789 goto xdp_xmit;
790 case XDP_REDIRECT:
791 get_page(virt_to_page(xdp.data));
792 consume_skb(skb);
793 xdp.rxq->mem = rq->xdp_mem;
794 if (xdp_do_redirect(rq->dev, &xdp, xdp_prog)) {
795 stats->rx_drops++;
796 goto err_xdp;
797 }
798 stats->xdp_redirect++;
799 rcu_read_unlock();
800 goto xdp_xmit;
801 default:
802 bpf_warn_invalid_xdp_action(act);
803 fallthrough;
804 case XDP_ABORTED:
805 trace_xdp_exception(rq->dev, xdp_prog, act);
806 fallthrough;
807 case XDP_DROP:
808 stats->xdp_drops++;
809 goto xdp_drop;
810 }
811 rcu_read_unlock();
812
813 /* check if bpf_xdp_adjust_head was used */
814 delta = orig_data - xdp.data;
815 off = mac_len + delta;
816 if (off > 0)
817 __skb_push(skb, off);
818 else if (off < 0)
819 __skb_pull(skb, -off);
820 skb->mac_header -= delta;
821
822 /* check if bpf_xdp_adjust_tail was used */
823 off = xdp.data_end - orig_data_end;
824 if (off != 0)
825 __skb_put(skb, off); /* positive on grow, negative on shrink */
826 skb->protocol = eth_type_trans(skb, rq->dev);
827
828 metalen = xdp.data - xdp.data_meta;
829 if (metalen)
830 skb_metadata_set(skb, metalen);
831out:
832 return skb;
833drop:
834 stats->rx_drops++;
835xdp_drop:
836 rcu_read_unlock();
837 kfree_skb(skb);
838 return NULL;
839err_xdp:
840 rcu_read_unlock();
841 page_frag_free(xdp.data);
842xdp_xmit:
843 return NULL;
844}
845
846static int veth_xdp_rcv(struct veth_rq *rq, int budget,
847 struct veth_xdp_tx_bq *bq,
848 struct veth_stats *stats)
849{
850 int i, done = 0, n_xdpf = 0;
851 void *xdpf[VETH_XDP_BATCH];
852
853 for (i = 0; i < budget; i++) {
854 void *ptr = __ptr_ring_consume(&rq->xdp_ring);
855
856 if (!ptr)
857 break;
858
859 if (veth_is_xdp_frame(ptr)) {
860 /* ndo_xdp_xmit */
861 struct xdp_frame *frame = veth_ptr_to_xdp(ptr);
862
863 stats->xdp_bytes += frame->len;
864 frame = veth_xdp_rcv_one(rq, frame, bq, stats);
865 if (frame) {
866 /* XDP_PASS */
867 xdpf[n_xdpf++] = frame;
868 if (n_xdpf == VETH_XDP_BATCH) {
869 veth_xdp_rcv_bulk_skb(rq, xdpf, n_xdpf,
870 bq, stats);
871 n_xdpf = 0;
872 }
873 }
874 } else {
875 /* ndo_start_xmit */
876 struct sk_buff *skb = ptr;
877
878 stats->xdp_bytes += skb->len;
879 skb = veth_xdp_rcv_skb(rq, skb, bq, stats);
880 if (skb)
881 napi_gro_receive(&rq->xdp_napi, skb);
882 }
883 done++;
884 }
885
886 if (n_xdpf)
887 veth_xdp_rcv_bulk_skb(rq, xdpf, n_xdpf, bq, stats);
888
889 u64_stats_update_begin(&rq->stats.syncp);
890 rq->stats.vs.xdp_redirect += stats->xdp_redirect;
891 rq->stats.vs.xdp_bytes += stats->xdp_bytes;
892 rq->stats.vs.xdp_drops += stats->xdp_drops;
893 rq->stats.vs.rx_drops += stats->rx_drops;
894 rq->stats.vs.xdp_packets += done;
895 u64_stats_update_end(&rq->stats.syncp);
896
897 return done;
898}
899
900static int veth_poll(struct napi_struct *napi, int budget)
901{
902 struct veth_rq *rq =
903 container_of(napi, struct veth_rq, xdp_napi);
904 struct veth_stats stats = {};
905 struct veth_xdp_tx_bq bq;
906 int done;
907
908 bq.count = 0;
909
910 xdp_set_return_frame_no_direct();
911 done = veth_xdp_rcv(rq, budget, &bq, &stats);
912
913 if (done < budget && napi_complete_done(napi, done)) {
914 /* Write rx_notify_masked before reading ptr_ring */
915 smp_store_mb(rq->rx_notify_masked, false);
916 if (unlikely(!__ptr_ring_empty(&rq->xdp_ring))) {
917 rq->rx_notify_masked = true;
918 napi_schedule(&rq->xdp_napi);
919 }
920 }
921
922 if (stats.xdp_tx > 0)
923 veth_xdp_flush(rq, &bq);
924 if (stats.xdp_redirect > 0)
925 xdp_do_flush();
926 xdp_clear_return_frame_no_direct();
927
928 return done;
929}
930
931static int __veth_napi_enable(struct net_device *dev)
932{
933 struct veth_priv *priv = netdev_priv(dev);
934 int err, i;
935
936 for (i = 0; i < dev->real_num_rx_queues; i++) {
937 struct veth_rq *rq = &priv->rq[i];
938
939 err = ptr_ring_init(&rq->xdp_ring, VETH_RING_SIZE, GFP_KERNEL);
940 if (err)
941 goto err_xdp_ring;
942 }
943
944 for (i = 0; i < dev->real_num_rx_queues; i++) {
945 struct veth_rq *rq = &priv->rq[i];
946
947 napi_enable(&rq->xdp_napi);
948 rcu_assign_pointer(priv->rq[i].napi, &priv->rq[i].xdp_napi);
949 }
950
951 return 0;
952err_xdp_ring:
953 for (i--; i >= 0; i--)
954 ptr_ring_cleanup(&priv->rq[i].xdp_ring, veth_ptr_free);
955
956 return err;
957}
958
959static void veth_napi_del(struct net_device *dev)
960{
961 struct veth_priv *priv = netdev_priv(dev);
962 int i;
963
964 for (i = 0; i < dev->real_num_rx_queues; i++) {
965 struct veth_rq *rq = &priv->rq[i];
966
967 rcu_assign_pointer(priv->rq[i].napi, NULL);
968 napi_disable(&rq->xdp_napi);
969 __netif_napi_del(&rq->xdp_napi);
970 }
971 synchronize_net();
972
973 for (i = 0; i < dev->real_num_rx_queues; i++) {
974 struct veth_rq *rq = &priv->rq[i];
975
976 rq->rx_notify_masked = false;
977 ptr_ring_cleanup(&rq->xdp_ring, veth_ptr_free);
978 }
979}
980
981static bool veth_gro_requested(const struct net_device *dev)
982{
983 return !!(dev->wanted_features & NETIF_F_GRO);
984}
985
986static int veth_enable_xdp(struct net_device *dev)
987{
988 bool napi_already_on = veth_gro_requested(dev) && (dev->flags & IFF_UP);
989 struct veth_priv *priv = netdev_priv(dev);
990 int err, i;
991
992 if (!xdp_rxq_info_is_reg(&priv->rq[0].xdp_rxq)) {
993 for (i = 0; i < dev->real_num_rx_queues; i++) {
994 struct veth_rq *rq = &priv->rq[i];
995
996 if (!napi_already_on)
997 netif_napi_add(dev, &rq->xdp_napi, veth_poll, NAPI_POLL_WEIGHT);
998 err = xdp_rxq_info_reg(&rq->xdp_rxq, dev, i, rq->xdp_napi.napi_id);
999 if (err < 0)
1000 goto err_rxq_reg;
1001
1002 err = xdp_rxq_info_reg_mem_model(&rq->xdp_rxq,
1003 MEM_TYPE_PAGE_SHARED,
1004 NULL);
1005 if (err < 0)
1006 goto err_reg_mem;
1007
1008 /* Save original mem info as it can be overwritten */
1009 rq->xdp_mem = rq->xdp_rxq.mem;
1010 }
1011
1012 if (!napi_already_on) {
1013 err = __veth_napi_enable(dev);
1014 if (err)
1015 goto err_rxq_reg;
1016
1017 if (!veth_gro_requested(dev)) {
1018 /* user-space did not require GRO, but adding XDP
1019 * is supposed to get GRO working
1020 */
1021 dev->features |= NETIF_F_GRO;
1022 netdev_features_change(dev);
1023 }
1024 }
1025 }
1026
1027 for (i = 0; i < dev->real_num_rx_queues; i++) {
1028 rcu_assign_pointer(priv->rq[i].xdp_prog, priv->_xdp_prog);
1029 rcu_assign_pointer(priv->rq[i].napi, &priv->rq[i].xdp_napi);
1030 }
1031
1032 return 0;
1033err_reg_mem:
1034 xdp_rxq_info_unreg(&priv->rq[i].xdp_rxq);
1035err_rxq_reg:
1036 for (i--; i >= 0; i--) {
1037 struct veth_rq *rq = &priv->rq[i];
1038
1039 xdp_rxq_info_unreg(&rq->xdp_rxq);
1040 if (!napi_already_on)
1041 netif_napi_del(&rq->xdp_napi);
1042 }
1043
1044 return err;
1045}
1046
1047static void veth_disable_xdp(struct net_device *dev)
1048{
1049 struct veth_priv *priv = netdev_priv(dev);
1050 int i;
1051
1052 for (i = 0; i < dev->real_num_rx_queues; i++)
1053 rcu_assign_pointer(priv->rq[i].xdp_prog, NULL);
1054
1055 if (!netif_running(dev) || !veth_gro_requested(dev)) {
1056 veth_napi_del(dev);
1057
1058 /* if user-space did not require GRO, since adding XDP
1059 * enabled it, clear it now
1060 */
1061 if (!veth_gro_requested(dev) && netif_running(dev)) {
1062 dev->features &= ~NETIF_F_GRO;
1063 netdev_features_change(dev);
1064 }
1065 }
1066
1067 for (i = 0; i < dev->real_num_rx_queues; i++) {
1068 struct veth_rq *rq = &priv->rq[i];
1069
1070 rq->xdp_rxq.mem = rq->xdp_mem;
1071 xdp_rxq_info_unreg(&rq->xdp_rxq);
1072 }
1073}
1074
1075static int veth_napi_enable(struct net_device *dev)
1076{
1077 struct veth_priv *priv = netdev_priv(dev);
1078 int err, i;
1079
1080 for (i = 0; i < dev->real_num_rx_queues; i++) {
1081 struct veth_rq *rq = &priv->rq[i];
1082
1083 netif_napi_add(dev, &rq->xdp_napi, veth_poll, NAPI_POLL_WEIGHT);
1084 }
1085
1086 err = __veth_napi_enable(dev);
1087 if (err) {
1088 for (i = 0; i < dev->real_num_rx_queues; i++) {
1089 struct veth_rq *rq = &priv->rq[i];
1090
1091 netif_napi_del(&rq->xdp_napi);
1092 }
1093 return err;
1094 }
1095 return err;
1096}
1097
1098static int veth_open(struct net_device *dev)
1099{
1100 struct veth_priv *priv = netdev_priv(dev);
1101 struct net_device *peer = rtnl_dereference(priv->peer);
1102 int err;
1103
1104 if (!peer)
1105 return -ENOTCONN;
1106
1107 if (priv->_xdp_prog) {
1108 err = veth_enable_xdp(dev);
1109 if (err)
1110 return err;
1111 } else if (veth_gro_requested(dev)) {
1112 err = veth_napi_enable(dev);
1113 if (err)
1114 return err;
1115 }
1116
1117 if (peer->flags & IFF_UP) {
1118 netif_carrier_on(dev);
1119 netif_carrier_on(peer);
1120 }
1121
1122 return 0;
1123}
1124
1125static int veth_close(struct net_device *dev)
1126{
1127 struct veth_priv *priv = netdev_priv(dev);
1128 struct net_device *peer = rtnl_dereference(priv->peer);
1129
1130 netif_carrier_off(dev);
1131 if (peer)
1132 netif_carrier_off(peer);
1133
1134 if (priv->_xdp_prog)
1135 veth_disable_xdp(dev);
1136 else if (veth_gro_requested(dev))
1137 veth_napi_del(dev);
1138
1139 return 0;
1140}
1141
1142static int is_valid_veth_mtu(int mtu)
1143{
1144 return mtu >= ETH_MIN_MTU && mtu <= ETH_MAX_MTU;
1145}
1146
1147static int veth_alloc_queues(struct net_device *dev)
1148{
1149 struct veth_priv *priv = netdev_priv(dev);
1150 int i;
1151
1152 priv->rq = kcalloc(dev->num_rx_queues, sizeof(*priv->rq), GFP_KERNEL);
1153 if (!priv->rq)
1154 return -ENOMEM;
1155
1156 for (i = 0; i < dev->num_rx_queues; i++) {
1157 priv->rq[i].dev = dev;
1158 u64_stats_init(&priv->rq[i].stats.syncp);
1159 }
1160
1161 return 0;
1162}
1163
1164static void veth_free_queues(struct net_device *dev)
1165{
1166 struct veth_priv *priv = netdev_priv(dev);
1167
1168 kfree(priv->rq);
1169}
1170
1171static int veth_dev_init(struct net_device *dev)
1172{
1173 int err;
1174
1175 dev->lstats = netdev_alloc_pcpu_stats(struct pcpu_lstats);
1176 if (!dev->lstats)
1177 return -ENOMEM;
1178
1179 err = veth_alloc_queues(dev);
1180 if (err) {
1181 free_percpu(dev->lstats);
1182 return err;
1183 }
1184
1185 return 0;
1186}
1187
1188static void veth_dev_free(struct net_device *dev)
1189{
1190 veth_free_queues(dev);
1191 free_percpu(dev->lstats);
1192}
1193
1194#ifdef CONFIG_NET_POLL_CONTROLLER
1195static void veth_poll_controller(struct net_device *dev)
1196{
1197 /* veth only receives frames when its peer sends one
1198 * Since it has nothing to do with disabling irqs, we are guaranteed
1199 * never to have pending data when we poll for it so
1200 * there is nothing to do here.
1201 *
1202 * We need this though so netpoll recognizes us as an interface that
1203 * supports polling, which enables bridge devices in virt setups to
1204 * still use netconsole
1205 */
1206}
1207#endif /* CONFIG_NET_POLL_CONTROLLER */
1208
1209static int veth_get_iflink(const struct net_device *dev)
1210{
1211 struct veth_priv *priv = netdev_priv(dev);
1212 struct net_device *peer;
1213 int iflink;
1214
1215 rcu_read_lock();
1216 peer = rcu_dereference(priv->peer);
1217 iflink = peer ? peer->ifindex : 0;
1218 rcu_read_unlock();
1219
1220 return iflink;
1221}
1222
1223static netdev_features_t veth_fix_features(struct net_device *dev,
1224 netdev_features_t features)
1225{
1226 struct veth_priv *priv = netdev_priv(dev);
1227 struct net_device *peer;
1228
1229 peer = rtnl_dereference(priv->peer);
1230 if (peer) {
1231 struct veth_priv *peer_priv = netdev_priv(peer);
1232
1233 if (peer_priv->_xdp_prog)
1234 features &= ~NETIF_F_GSO_SOFTWARE;
1235 }
1236 if (priv->_xdp_prog)
1237 features |= NETIF_F_GRO;
1238
1239 return features;
1240}
1241
1242static int veth_set_features(struct net_device *dev,
1243 netdev_features_t features)
1244{
1245 netdev_features_t changed = features ^ dev->features;
1246 struct veth_priv *priv = netdev_priv(dev);
1247 int err;
1248
1249 if (!(changed & NETIF_F_GRO) || !(dev->flags & IFF_UP) || priv->_xdp_prog)
1250 return 0;
1251
1252 if (features & NETIF_F_GRO) {
1253 err = veth_napi_enable(dev);
1254 if (err)
1255 return err;
1256 } else {
1257 veth_napi_del(dev);
1258 }
1259 return 0;
1260}
1261
1262static void veth_set_rx_headroom(struct net_device *dev, int new_hr)
1263{
1264 struct veth_priv *peer_priv, *priv = netdev_priv(dev);
1265 struct net_device *peer;
1266
1267 if (new_hr < 0)
1268 new_hr = 0;
1269
1270 rcu_read_lock();
1271 peer = rcu_dereference(priv->peer);
1272 if (unlikely(!peer))
1273 goto out;
1274
1275 peer_priv = netdev_priv(peer);
1276 priv->requested_headroom = new_hr;
1277 new_hr = max(priv->requested_headroom, peer_priv->requested_headroom);
1278 dev->needed_headroom = new_hr;
1279 peer->needed_headroom = new_hr;
1280
1281out:
1282 rcu_read_unlock();
1283}
1284
1285static int veth_xdp_set(struct net_device *dev, struct bpf_prog *prog,
1286 struct netlink_ext_ack *extack)
1287{
1288 struct veth_priv *priv = netdev_priv(dev);
1289 struct bpf_prog *old_prog;
1290 struct net_device *peer;
1291 unsigned int max_mtu;
1292 int err;
1293
1294 old_prog = priv->_xdp_prog;
1295 priv->_xdp_prog = prog;
1296 peer = rtnl_dereference(priv->peer);
1297
1298 if (prog) {
1299 if (!peer) {
1300 NL_SET_ERR_MSG_MOD(extack, "Cannot set XDP when peer is detached");
1301 err = -ENOTCONN;
1302 goto err;
1303 }
1304
1305 max_mtu = PAGE_SIZE - VETH_XDP_HEADROOM -
1306 peer->hard_header_len -
1307 SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
1308 if (peer->mtu > max_mtu) {
1309 NL_SET_ERR_MSG_MOD(extack, "Peer MTU is too large to set XDP");
1310 err = -ERANGE;
1311 goto err;
1312 }
1313
1314 if (dev->real_num_rx_queues < peer->real_num_tx_queues) {
1315 NL_SET_ERR_MSG_MOD(extack, "XDP expects number of rx queues not less than peer tx queues");
1316 err = -ENOSPC;
1317 goto err;
1318 }
1319
1320 if (dev->flags & IFF_UP) {
1321 err = veth_enable_xdp(dev);
1322 if (err) {
1323 NL_SET_ERR_MSG_MOD(extack, "Setup for XDP failed");
1324 goto err;
1325 }
1326 }
1327
1328 if (!old_prog) {
1329 peer->hw_features &= ~NETIF_F_GSO_SOFTWARE;
1330 peer->max_mtu = max_mtu;
1331 }
1332 }
1333
1334 if (old_prog) {
1335 if (!prog) {
1336 if (dev->flags & IFF_UP)
1337 veth_disable_xdp(dev);
1338
1339 if (peer) {
1340 peer->hw_features |= NETIF_F_GSO_SOFTWARE;
1341 peer->max_mtu = ETH_MAX_MTU;
1342 }
1343 }
1344 bpf_prog_put(old_prog);
1345 }
1346
1347 if ((!!old_prog ^ !!prog) && peer)
1348 netdev_update_features(peer);
1349
1350 return 0;
1351err:
1352 priv->_xdp_prog = old_prog;
1353
1354 return err;
1355}
1356
1357static int veth_xdp(struct net_device *dev, struct netdev_bpf *xdp)
1358{
1359 switch (xdp->command) {
1360 case XDP_SETUP_PROG:
1361 return veth_xdp_set(dev, xdp->prog, xdp->extack);
1362 default:
1363 return -EINVAL;
1364 }
1365}
1366
1367static const struct net_device_ops veth_netdev_ops = {
1368 .ndo_init = veth_dev_init,
1369 .ndo_open = veth_open,
1370 .ndo_stop = veth_close,
1371 .ndo_start_xmit = veth_xmit,
1372 .ndo_get_stats64 = veth_get_stats64,
1373 .ndo_set_rx_mode = veth_set_multicast_list,
1374 .ndo_set_mac_address = eth_mac_addr,
1375#ifdef CONFIG_NET_POLL_CONTROLLER
1376 .ndo_poll_controller = veth_poll_controller,
1377#endif
1378 .ndo_get_iflink = veth_get_iflink,
1379 .ndo_fix_features = veth_fix_features,
1380 .ndo_set_features = veth_set_features,
1381 .ndo_features_check = passthru_features_check,
1382 .ndo_set_rx_headroom = veth_set_rx_headroom,
1383 .ndo_bpf = veth_xdp,
1384 .ndo_xdp_xmit = veth_ndo_xdp_xmit,
1385 .ndo_get_peer_dev = veth_peer_dev,
1386};
1387
1388#define VETH_FEATURES (NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HW_CSUM | \
1389 NETIF_F_RXCSUM | NETIF_F_SCTP_CRC | NETIF_F_HIGHDMA | \
1390 NETIF_F_GSO_SOFTWARE | NETIF_F_GSO_ENCAP_ALL | \
1391 NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_CTAG_RX | \
1392 NETIF_F_HW_VLAN_STAG_TX | NETIF_F_HW_VLAN_STAG_RX )
1393
1394static void veth_setup(struct net_device *dev)
1395{
1396 ether_setup(dev);
1397
1398 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1399 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1400 dev->priv_flags |= IFF_NO_QUEUE;
1401 dev->priv_flags |= IFF_PHONY_HEADROOM;
1402
1403 dev->netdev_ops = &veth_netdev_ops;
1404 dev->ethtool_ops = &veth_ethtool_ops;
1405 dev->features |= NETIF_F_LLTX;
1406 dev->features |= VETH_FEATURES;
1407 dev->vlan_features = dev->features &
1408 ~(NETIF_F_HW_VLAN_CTAG_TX |
1409 NETIF_F_HW_VLAN_STAG_TX |
1410 NETIF_F_HW_VLAN_CTAG_RX |
1411 NETIF_F_HW_VLAN_STAG_RX);
1412 dev->needs_free_netdev = true;
1413 dev->priv_destructor = veth_dev_free;
1414 dev->max_mtu = ETH_MAX_MTU;
1415
1416 dev->hw_features = VETH_FEATURES;
1417 dev->hw_enc_features = VETH_FEATURES;
1418 dev->mpls_features = NETIF_F_HW_CSUM | NETIF_F_GSO_SOFTWARE;
1419}
1420
1421/*
1422 * netlink interface
1423 */
1424
1425static int veth_validate(struct nlattr *tb[], struct nlattr *data[],
1426 struct netlink_ext_ack *extack)
1427{
1428 if (tb[IFLA_ADDRESS]) {
1429 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1430 return -EINVAL;
1431 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1432 return -EADDRNOTAVAIL;
1433 }
1434 if (tb[IFLA_MTU]) {
1435 if (!is_valid_veth_mtu(nla_get_u32(tb[IFLA_MTU])))
1436 return -EINVAL;
1437 }
1438 return 0;
1439}
1440
1441static struct rtnl_link_ops veth_link_ops;
1442
1443static void veth_disable_gro(struct net_device *dev)
1444{
1445 dev->features &= ~NETIF_F_GRO;
1446 dev->wanted_features &= ~NETIF_F_GRO;
1447 netdev_update_features(dev);
1448}
1449
1450static int veth_newlink(struct net *src_net, struct net_device *dev,
1451 struct nlattr *tb[], struct nlattr *data[],
1452 struct netlink_ext_ack *extack)
1453{
1454 int err;
1455 struct net_device *peer;
1456 struct veth_priv *priv;
1457 char ifname[IFNAMSIZ];
1458 struct nlattr *peer_tb[IFLA_MAX + 1], **tbp;
1459 unsigned char name_assign_type;
1460 struct ifinfomsg *ifmp;
1461 struct net *net;
1462
1463 /*
1464 * create and register peer first
1465 */
1466 if (data != NULL && data[VETH_INFO_PEER] != NULL) {
1467 struct nlattr *nla_peer;
1468
1469 nla_peer = data[VETH_INFO_PEER];
1470 ifmp = nla_data(nla_peer);
1471 err = rtnl_nla_parse_ifla(peer_tb,
1472 nla_data(nla_peer) + sizeof(struct ifinfomsg),
1473 nla_len(nla_peer) - sizeof(struct ifinfomsg),
1474 NULL);
1475 if (err < 0)
1476 return err;
1477
1478 err = veth_validate(peer_tb, NULL, extack);
1479 if (err < 0)
1480 return err;
1481
1482 tbp = peer_tb;
1483 } else {
1484 ifmp = NULL;
1485 tbp = tb;
1486 }
1487
1488 if (ifmp && tbp[IFLA_IFNAME]) {
1489 nla_strscpy(ifname, tbp[IFLA_IFNAME], IFNAMSIZ);
1490 name_assign_type = NET_NAME_USER;
1491 } else {
1492 snprintf(ifname, IFNAMSIZ, DRV_NAME "%%d");
1493 name_assign_type = NET_NAME_ENUM;
1494 }
1495
1496 net = rtnl_link_get_net(src_net, tbp);
1497 if (IS_ERR(net))
1498 return PTR_ERR(net);
1499
1500 peer = rtnl_create_link(net, ifname, name_assign_type,
1501 &veth_link_ops, tbp, extack);
1502 if (IS_ERR(peer)) {
1503 put_net(net);
1504 return PTR_ERR(peer);
1505 }
1506
1507 if (!ifmp || !tbp[IFLA_ADDRESS])
1508 eth_hw_addr_random(peer);
1509
1510 if (ifmp && (dev->ifindex != 0))
1511 peer->ifindex = ifmp->ifi_index;
1512
1513 peer->gso_max_size = dev->gso_max_size;
1514 peer->gso_max_segs = dev->gso_max_segs;
1515
1516 err = register_netdevice(peer);
1517 put_net(net);
1518 net = NULL;
1519 if (err < 0)
1520 goto err_register_peer;
1521
1522 /* keep GRO disabled by default to be consistent with the established
1523 * veth behavior
1524 */
1525 veth_disable_gro(peer);
1526 netif_carrier_off(peer);
1527
1528 err = rtnl_configure_link(peer, ifmp);
1529 if (err < 0)
1530 goto err_configure_peer;
1531
1532 /*
1533 * register dev last
1534 *
1535 * note, that since we've registered new device the dev's name
1536 * should be re-allocated
1537 */
1538
1539 if (tb[IFLA_ADDRESS] == NULL)
1540 eth_hw_addr_random(dev);
1541
1542 if (tb[IFLA_IFNAME])
1543 nla_strscpy(dev->name, tb[IFLA_IFNAME], IFNAMSIZ);
1544 else
1545 snprintf(dev->name, IFNAMSIZ, DRV_NAME "%%d");
1546
1547 err = register_netdevice(dev);
1548 if (err < 0)
1549 goto err_register_dev;
1550
1551 netif_carrier_off(dev);
1552
1553 /*
1554 * tie the deviced together
1555 */
1556
1557 priv = netdev_priv(dev);
1558 rcu_assign_pointer(priv->peer, peer);
1559
1560 priv = netdev_priv(peer);
1561 rcu_assign_pointer(priv->peer, dev);
1562
1563 veth_disable_gro(dev);
1564 return 0;
1565
1566err_register_dev:
1567 /* nothing to do */
1568err_configure_peer:
1569 unregister_netdevice(peer);
1570 return err;
1571
1572err_register_peer:
1573 free_netdev(peer);
1574 return err;
1575}
1576
1577static void veth_dellink(struct net_device *dev, struct list_head *head)
1578{
1579 struct veth_priv *priv;
1580 struct net_device *peer;
1581
1582 priv = netdev_priv(dev);
1583 peer = rtnl_dereference(priv->peer);
1584
1585 /* Note : dellink() is called from default_device_exit_batch(),
1586 * before a rcu_synchronize() point. The devices are guaranteed
1587 * not being freed before one RCU grace period.
1588 */
1589 RCU_INIT_POINTER(priv->peer, NULL);
1590 unregister_netdevice_queue(dev, head);
1591
1592 if (peer) {
1593 priv = netdev_priv(peer);
1594 RCU_INIT_POINTER(priv->peer, NULL);
1595 unregister_netdevice_queue(peer, head);
1596 }
1597}
1598
1599static const struct nla_policy veth_policy[VETH_INFO_MAX + 1] = {
1600 [VETH_INFO_PEER] = { .len = sizeof(struct ifinfomsg) },
1601};
1602
1603static struct net *veth_get_link_net(const struct net_device *dev)
1604{
1605 struct veth_priv *priv = netdev_priv(dev);
1606 struct net_device *peer = rtnl_dereference(priv->peer);
1607
1608 return peer ? dev_net(peer) : dev_net(dev);
1609}
1610
1611static struct rtnl_link_ops veth_link_ops = {
1612 .kind = DRV_NAME,
1613 .priv_size = sizeof(struct veth_priv),
1614 .setup = veth_setup,
1615 .validate = veth_validate,
1616 .newlink = veth_newlink,
1617 .dellink = veth_dellink,
1618 .policy = veth_policy,
1619 .maxtype = VETH_INFO_MAX,
1620 .get_link_net = veth_get_link_net,
1621};
1622
1623/*
1624 * init/fini
1625 */
1626
1627static __init int veth_init(void)
1628{
1629 return rtnl_link_register(&veth_link_ops);
1630}
1631
1632static __exit void veth_exit(void)
1633{
1634 rtnl_link_unregister(&veth_link_ops);
1635}
1636
1637module_init(veth_init);
1638module_exit(veth_exit);
1639
1640MODULE_DESCRIPTION("Virtual Ethernet Tunnel");
1641MODULE_LICENSE("GPL v2");
1642MODULE_ALIAS_RTNL_LINK(DRV_NAME);