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#include <net/page_pool/helpers.h>
30
31#define DRV_NAME "veth"
32#define DRV_VERSION "1.0"
33
34#define VETH_XDP_FLAG BIT(0)
35#define VETH_RING_SIZE 256
36#define VETH_XDP_HEADROOM (XDP_PACKET_HEADROOM + NET_IP_ALIGN)
37
38#define VETH_XDP_TX_BULK_SIZE 16
39#define VETH_XDP_BATCH 16
40
41struct veth_stats {
42 u64 rx_drops;
43 /* xdp */
44 u64 xdp_packets;
45 u64 xdp_bytes;
46 u64 xdp_redirect;
47 u64 xdp_drops;
48 u64 xdp_tx;
49 u64 xdp_tx_err;
50 u64 peer_tq_xdp_xmit;
51 u64 peer_tq_xdp_xmit_err;
52};
53
54struct veth_rq_stats {
55 struct veth_stats vs;
56 struct u64_stats_sync syncp;
57};
58
59struct veth_rq {
60 struct napi_struct xdp_napi;
61 struct napi_struct __rcu *napi; /* points to xdp_napi when the latter is initialized */
62 struct net_device *dev;
63 struct bpf_prog __rcu *xdp_prog;
64 struct xdp_mem_info xdp_mem;
65 struct veth_rq_stats stats;
66 bool rx_notify_masked;
67 struct ptr_ring xdp_ring;
68 struct xdp_rxq_info xdp_rxq;
69 struct page_pool *page_pool;
70};
71
72struct veth_priv {
73 struct net_device __rcu *peer;
74 atomic64_t dropped;
75 struct bpf_prog *_xdp_prog;
76 struct veth_rq *rq;
77 unsigned int requested_headroom;
78};
79
80struct veth_xdp_tx_bq {
81 struct xdp_frame *q[VETH_XDP_TX_BULK_SIZE];
82 unsigned int count;
83};
84
85/*
86 * ethtool interface
87 */
88
89struct veth_q_stat_desc {
90 char desc[ETH_GSTRING_LEN];
91 size_t offset;
92};
93
94#define VETH_RQ_STAT(m) offsetof(struct veth_stats, m)
95
96static const struct veth_q_stat_desc veth_rq_stats_desc[] = {
97 { "xdp_packets", VETH_RQ_STAT(xdp_packets) },
98 { "xdp_bytes", VETH_RQ_STAT(xdp_bytes) },
99 { "drops", VETH_RQ_STAT(rx_drops) },
100 { "xdp_redirect", VETH_RQ_STAT(xdp_redirect) },
101 { "xdp_drops", VETH_RQ_STAT(xdp_drops) },
102 { "xdp_tx", VETH_RQ_STAT(xdp_tx) },
103 { "xdp_tx_errors", VETH_RQ_STAT(xdp_tx_err) },
104};
105
106#define VETH_RQ_STATS_LEN ARRAY_SIZE(veth_rq_stats_desc)
107
108static const struct veth_q_stat_desc veth_tq_stats_desc[] = {
109 { "xdp_xmit", VETH_RQ_STAT(peer_tq_xdp_xmit) },
110 { "xdp_xmit_errors", VETH_RQ_STAT(peer_tq_xdp_xmit_err) },
111};
112
113#define VETH_TQ_STATS_LEN ARRAY_SIZE(veth_tq_stats_desc)
114
115static struct {
116 const char string[ETH_GSTRING_LEN];
117} ethtool_stats_keys[] = {
118 { "peer_ifindex" },
119};
120
121struct veth_xdp_buff {
122 struct xdp_buff xdp;
123 struct sk_buff *skb;
124};
125
126static int veth_get_link_ksettings(struct net_device *dev,
127 struct ethtool_link_ksettings *cmd)
128{
129 cmd->base.speed = SPEED_10000;
130 cmd->base.duplex = DUPLEX_FULL;
131 cmd->base.port = PORT_TP;
132 cmd->base.autoneg = AUTONEG_DISABLE;
133 return 0;
134}
135
136static void veth_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
137{
138 strscpy(info->driver, DRV_NAME, sizeof(info->driver));
139 strscpy(info->version, DRV_VERSION, sizeof(info->version));
140}
141
142static void veth_get_strings(struct net_device *dev, u32 stringset, u8 *buf)
143{
144 u8 *p = buf;
145 int i, j;
146
147 switch(stringset) {
148 case ETH_SS_STATS:
149 memcpy(p, &ethtool_stats_keys, sizeof(ethtool_stats_keys));
150 p += sizeof(ethtool_stats_keys);
151 for (i = 0; i < dev->real_num_rx_queues; i++)
152 for (j = 0; j < VETH_RQ_STATS_LEN; j++)
153 ethtool_sprintf(data: &p, fmt: "rx_queue_%u_%.18s",
154 i, veth_rq_stats_desc[j].desc);
155
156 for (i = 0; i < dev->real_num_tx_queues; i++)
157 for (j = 0; j < VETH_TQ_STATS_LEN; j++)
158 ethtool_sprintf(data: &p, fmt: "tx_queue_%u_%.18s",
159 i, veth_tq_stats_desc[j].desc);
160
161 page_pool_ethtool_stats_get_strings(data: p);
162 break;
163 }
164}
165
166static int veth_get_sset_count(struct net_device *dev, int sset)
167{
168 switch (sset) {
169 case ETH_SS_STATS:
170 return ARRAY_SIZE(ethtool_stats_keys) +
171 VETH_RQ_STATS_LEN * dev->real_num_rx_queues +
172 VETH_TQ_STATS_LEN * dev->real_num_tx_queues +
173 page_pool_ethtool_stats_get_count();
174 default:
175 return -EOPNOTSUPP;
176 }
177}
178
179static void veth_get_page_pool_stats(struct net_device *dev, u64 *data)
180{
181#ifdef CONFIG_PAGE_POOL_STATS
182 struct veth_priv *priv = netdev_priv(dev);
183 struct page_pool_stats pp_stats = {};
184 int i;
185
186 for (i = 0; i < dev->real_num_rx_queues; i++) {
187 if (!priv->rq[i].page_pool)
188 continue;
189 page_pool_get_stats(pool: priv->rq[i].page_pool, stats: &pp_stats);
190 }
191 page_pool_ethtool_stats_get(data, stats: &pp_stats);
192#endif /* CONFIG_PAGE_POOL_STATS */
193}
194
195static void veth_get_ethtool_stats(struct net_device *dev,
196 struct ethtool_stats *stats, u64 *data)
197{
198 struct veth_priv *rcv_priv, *priv = netdev_priv(dev);
199 struct net_device *peer = rtnl_dereference(priv->peer);
200 int i, j, idx, pp_idx;
201
202 data[0] = peer ? peer->ifindex : 0;
203 idx = 1;
204 for (i = 0; i < dev->real_num_rx_queues; i++) {
205 const struct veth_rq_stats *rq_stats = &priv->rq[i].stats;
206 const void *stats_base = (void *)&rq_stats->vs;
207 unsigned int start;
208 size_t offset;
209
210 do {
211 start = u64_stats_fetch_begin(syncp: &rq_stats->syncp);
212 for (j = 0; j < VETH_RQ_STATS_LEN; j++) {
213 offset = veth_rq_stats_desc[j].offset;
214 data[idx + j] = *(u64 *)(stats_base + offset);
215 }
216 } while (u64_stats_fetch_retry(syncp: &rq_stats->syncp, start));
217 idx += VETH_RQ_STATS_LEN;
218 }
219 pp_idx = idx;
220
221 if (!peer)
222 goto page_pool_stats;
223
224 rcv_priv = netdev_priv(dev: peer);
225 for (i = 0; i < peer->real_num_rx_queues; i++) {
226 const struct veth_rq_stats *rq_stats = &rcv_priv->rq[i].stats;
227 const void *base = (void *)&rq_stats->vs;
228 unsigned int start, tx_idx = idx;
229 size_t offset;
230
231 tx_idx += (i % dev->real_num_tx_queues) * VETH_TQ_STATS_LEN;
232 do {
233 start = u64_stats_fetch_begin(syncp: &rq_stats->syncp);
234 for (j = 0; j < VETH_TQ_STATS_LEN; j++) {
235 offset = veth_tq_stats_desc[j].offset;
236 data[tx_idx + j] += *(u64 *)(base + offset);
237 }
238 } while (u64_stats_fetch_retry(syncp: &rq_stats->syncp, start));
239 }
240 pp_idx = idx + dev->real_num_tx_queues * VETH_TQ_STATS_LEN;
241
242page_pool_stats:
243 veth_get_page_pool_stats(dev, data: &data[pp_idx]);
244}
245
246static void veth_get_channels(struct net_device *dev,
247 struct ethtool_channels *channels)
248{
249 channels->tx_count = dev->real_num_tx_queues;
250 channels->rx_count = dev->real_num_rx_queues;
251 channels->max_tx = dev->num_tx_queues;
252 channels->max_rx = dev->num_rx_queues;
253}
254
255static int veth_set_channels(struct net_device *dev,
256 struct ethtool_channels *ch);
257
258static const struct ethtool_ops veth_ethtool_ops = {
259 .get_drvinfo = veth_get_drvinfo,
260 .get_link = ethtool_op_get_link,
261 .get_strings = veth_get_strings,
262 .get_sset_count = veth_get_sset_count,
263 .get_ethtool_stats = veth_get_ethtool_stats,
264 .get_link_ksettings = veth_get_link_ksettings,
265 .get_ts_info = ethtool_op_get_ts_info,
266 .get_channels = veth_get_channels,
267 .set_channels = veth_set_channels,
268};
269
270/* general routines */
271
272static bool veth_is_xdp_frame(void *ptr)
273{
274 return (unsigned long)ptr & VETH_XDP_FLAG;
275}
276
277static struct xdp_frame *veth_ptr_to_xdp(void *ptr)
278{
279 return (void *)((unsigned long)ptr & ~VETH_XDP_FLAG);
280}
281
282static void *veth_xdp_to_ptr(struct xdp_frame *xdp)
283{
284 return (void *)((unsigned long)xdp | VETH_XDP_FLAG);
285}
286
287static void veth_ptr_free(void *ptr)
288{
289 if (veth_is_xdp_frame(ptr))
290 xdp_return_frame(xdpf: veth_ptr_to_xdp(ptr));
291 else
292 kfree_skb(skb: ptr);
293}
294
295static void __veth_xdp_flush(struct veth_rq *rq)
296{
297 /* Write ptr_ring before reading rx_notify_masked */
298 smp_mb();
299 if (!READ_ONCE(rq->rx_notify_masked) &&
300 napi_schedule_prep(n: &rq->xdp_napi)) {
301 WRITE_ONCE(rq->rx_notify_masked, true);
302 __napi_schedule(n: &rq->xdp_napi);
303 }
304}
305
306static int veth_xdp_rx(struct veth_rq *rq, struct sk_buff *skb)
307{
308 if (unlikely(ptr_ring_produce(&rq->xdp_ring, skb))) {
309 dev_kfree_skb_any(skb);
310 return NET_RX_DROP;
311 }
312
313 return NET_RX_SUCCESS;
314}
315
316static int veth_forward_skb(struct net_device *dev, struct sk_buff *skb,
317 struct veth_rq *rq, bool xdp)
318{
319 return __dev_forward_skb(dev, skb) ?: xdp ?
320 veth_xdp_rx(rq, skb) :
321 __netif_rx(skb);
322}
323
324/* return true if the specified skb has chances of GRO aggregation
325 * Don't strive for accuracy, but try to avoid GRO overhead in the most
326 * common scenarios.
327 * When XDP is enabled, all traffic is considered eligible, as the xmit
328 * device has TSO off.
329 * When TSO is enabled on the xmit device, we are likely interested only
330 * in UDP aggregation, explicitly check for that if the skb is suspected
331 * - the sock_wfree destructor is used by UDP, ICMP and XDP sockets -
332 * to belong to locally generated UDP traffic.
333 */
334static bool veth_skb_is_eligible_for_gro(const struct net_device *dev,
335 const struct net_device *rcv,
336 const struct sk_buff *skb)
337{
338 return !(dev->features & NETIF_F_ALL_TSO) ||
339 (skb->destructor == sock_wfree &&
340 rcv->features & (NETIF_F_GRO_FRAGLIST | NETIF_F_GRO_UDP_FWD));
341}
342
343static netdev_tx_t veth_xmit(struct sk_buff *skb, struct net_device *dev)
344{
345 struct veth_priv *rcv_priv, *priv = netdev_priv(dev);
346 struct veth_rq *rq = NULL;
347 int ret = NETDEV_TX_OK;
348 struct net_device *rcv;
349 int length = skb->len;
350 bool use_napi = false;
351 int rxq;
352
353 rcu_read_lock();
354 rcv = rcu_dereference(priv->peer);
355 if (unlikely(!rcv) || !pskb_may_pull(skb, ETH_HLEN)) {
356 kfree_skb(skb);
357 goto drop;
358 }
359
360 rcv_priv = netdev_priv(dev: rcv);
361 rxq = skb_get_queue_mapping(skb);
362 if (rxq < rcv->real_num_rx_queues) {
363 rq = &rcv_priv->rq[rxq];
364
365 /* The napi pointer is available when an XDP program is
366 * attached or when GRO is enabled
367 * Don't bother with napi/GRO if the skb can't be aggregated
368 */
369 use_napi = rcu_access_pointer(rq->napi) &&
370 veth_skb_is_eligible_for_gro(dev, rcv, skb);
371 }
372
373 skb_tx_timestamp(skb);
374 if (likely(veth_forward_skb(rcv, skb, rq, use_napi) == NET_RX_SUCCESS)) {
375 if (!use_napi)
376 dev_sw_netstats_tx_add(dev, packets: 1, len: length);
377 else
378 __veth_xdp_flush(rq);
379 } else {
380drop:
381 atomic64_inc(v: &priv->dropped);
382 ret = NET_XMIT_DROP;
383 }
384
385 rcu_read_unlock();
386
387 return ret;
388}
389
390static void veth_stats_rx(struct veth_stats *result, struct net_device *dev)
391{
392 struct veth_priv *priv = netdev_priv(dev);
393 int i;
394
395 result->peer_tq_xdp_xmit_err = 0;
396 result->xdp_packets = 0;
397 result->xdp_tx_err = 0;
398 result->xdp_bytes = 0;
399 result->rx_drops = 0;
400 for (i = 0; i < dev->num_rx_queues; i++) {
401 u64 packets, bytes, drops, xdp_tx_err, peer_tq_xdp_xmit_err;
402 struct veth_rq_stats *stats = &priv->rq[i].stats;
403 unsigned int start;
404
405 do {
406 start = u64_stats_fetch_begin(syncp: &stats->syncp);
407 peer_tq_xdp_xmit_err = stats->vs.peer_tq_xdp_xmit_err;
408 xdp_tx_err = stats->vs.xdp_tx_err;
409 packets = stats->vs.xdp_packets;
410 bytes = stats->vs.xdp_bytes;
411 drops = stats->vs.rx_drops;
412 } while (u64_stats_fetch_retry(syncp: &stats->syncp, start));
413 result->peer_tq_xdp_xmit_err += peer_tq_xdp_xmit_err;
414 result->xdp_tx_err += xdp_tx_err;
415 result->xdp_packets += packets;
416 result->xdp_bytes += bytes;
417 result->rx_drops += drops;
418 }
419}
420
421static void veth_get_stats64(struct net_device *dev,
422 struct rtnl_link_stats64 *tot)
423{
424 struct veth_priv *priv = netdev_priv(dev);
425 struct net_device *peer;
426 struct veth_stats rx;
427
428 tot->tx_dropped = atomic64_read(v: &priv->dropped);
429 dev_fetch_sw_netstats(s: tot, netstats: dev->tstats);
430
431 veth_stats_rx(result: &rx, dev);
432 tot->tx_dropped += rx.xdp_tx_err;
433 tot->rx_dropped = rx.rx_drops + rx.peer_tq_xdp_xmit_err;
434 tot->rx_bytes += rx.xdp_bytes;
435 tot->rx_packets += rx.xdp_packets;
436
437 rcu_read_lock();
438 peer = rcu_dereference(priv->peer);
439 if (peer) {
440 struct rtnl_link_stats64 tot_peer = {};
441
442 dev_fetch_sw_netstats(s: &tot_peer, netstats: peer->tstats);
443 tot->rx_bytes += tot_peer.tx_bytes;
444 tot->rx_packets += tot_peer.tx_packets;
445
446 veth_stats_rx(result: &rx, dev: peer);
447 tot->tx_dropped += rx.peer_tq_xdp_xmit_err;
448 tot->rx_dropped += rx.xdp_tx_err;
449 tot->tx_bytes += rx.xdp_bytes;
450 tot->tx_packets += rx.xdp_packets;
451 }
452 rcu_read_unlock();
453}
454
455/* fake multicast ability */
456static void veth_set_multicast_list(struct net_device *dev)
457{
458}
459
460static int veth_select_rxq(struct net_device *dev)
461{
462 return smp_processor_id() % dev->real_num_rx_queues;
463}
464
465static struct net_device *veth_peer_dev(struct net_device *dev)
466{
467 struct veth_priv *priv = netdev_priv(dev);
468
469 /* Callers must be under RCU read side. */
470 return rcu_dereference(priv->peer);
471}
472
473static int veth_xdp_xmit(struct net_device *dev, int n,
474 struct xdp_frame **frames,
475 u32 flags, bool ndo_xmit)
476{
477 struct veth_priv *rcv_priv, *priv = netdev_priv(dev);
478 int i, ret = -ENXIO, nxmit = 0;
479 struct net_device *rcv;
480 unsigned int max_len;
481 struct veth_rq *rq;
482
483 if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK))
484 return -EINVAL;
485
486 rcu_read_lock();
487 rcv = rcu_dereference(priv->peer);
488 if (unlikely(!rcv))
489 goto out;
490
491 rcv_priv = netdev_priv(dev: rcv);
492 rq = &rcv_priv->rq[veth_select_rxq(dev: rcv)];
493 /* The napi pointer is set if NAPI is enabled, which ensures that
494 * xdp_ring is initialized on receive side and the peer device is up.
495 */
496 if (!rcu_access_pointer(rq->napi))
497 goto out;
498
499 max_len = rcv->mtu + rcv->hard_header_len + VLAN_HLEN;
500
501 spin_lock(lock: &rq->xdp_ring.producer_lock);
502 for (i = 0; i < n; i++) {
503 struct xdp_frame *frame = frames[i];
504 void *ptr = veth_xdp_to_ptr(xdp: frame);
505
506 if (unlikely(xdp_get_frame_len(frame) > max_len ||
507 __ptr_ring_produce(&rq->xdp_ring, ptr)))
508 break;
509 nxmit++;
510 }
511 spin_unlock(lock: &rq->xdp_ring.producer_lock);
512
513 if (flags & XDP_XMIT_FLUSH)
514 __veth_xdp_flush(rq);
515
516 ret = nxmit;
517 if (ndo_xmit) {
518 u64_stats_update_begin(syncp: &rq->stats.syncp);
519 rq->stats.vs.peer_tq_xdp_xmit += nxmit;
520 rq->stats.vs.peer_tq_xdp_xmit_err += n - nxmit;
521 u64_stats_update_end(syncp: &rq->stats.syncp);
522 }
523
524out:
525 rcu_read_unlock();
526
527 return ret;
528}
529
530static int veth_ndo_xdp_xmit(struct net_device *dev, int n,
531 struct xdp_frame **frames, u32 flags)
532{
533 int err;
534
535 err = veth_xdp_xmit(dev, n, frames, flags, ndo_xmit: true);
536 if (err < 0) {
537 struct veth_priv *priv = netdev_priv(dev);
538
539 atomic64_add(i: n, v: &priv->dropped);
540 }
541
542 return err;
543}
544
545static void veth_xdp_flush_bq(struct veth_rq *rq, struct veth_xdp_tx_bq *bq)
546{
547 int sent, i, err = 0, drops;
548
549 sent = veth_xdp_xmit(dev: rq->dev, n: bq->count, frames: bq->q, flags: 0, ndo_xmit: false);
550 if (sent < 0) {
551 err = sent;
552 sent = 0;
553 }
554
555 for (i = sent; unlikely(i < bq->count); i++)
556 xdp_return_frame(xdpf: bq->q[i]);
557
558 drops = bq->count - sent;
559 trace_xdp_bulk_tx(dev: rq->dev, sent, drops, err);
560
561 u64_stats_update_begin(syncp: &rq->stats.syncp);
562 rq->stats.vs.xdp_tx += sent;
563 rq->stats.vs.xdp_tx_err += drops;
564 u64_stats_update_end(syncp: &rq->stats.syncp);
565
566 bq->count = 0;
567}
568
569static void veth_xdp_flush(struct veth_rq *rq, struct veth_xdp_tx_bq *bq)
570{
571 struct veth_priv *rcv_priv, *priv = netdev_priv(dev: rq->dev);
572 struct net_device *rcv;
573 struct veth_rq *rcv_rq;
574
575 rcu_read_lock();
576 veth_xdp_flush_bq(rq, bq);
577 rcv = rcu_dereference(priv->peer);
578 if (unlikely(!rcv))
579 goto out;
580
581 rcv_priv = netdev_priv(dev: rcv);
582 rcv_rq = &rcv_priv->rq[veth_select_rxq(dev: rcv)];
583 /* xdp_ring is initialized on receive side? */
584 if (unlikely(!rcu_access_pointer(rcv_rq->xdp_prog)))
585 goto out;
586
587 __veth_xdp_flush(rq: rcv_rq);
588out:
589 rcu_read_unlock();
590}
591
592static int veth_xdp_tx(struct veth_rq *rq, struct xdp_buff *xdp,
593 struct veth_xdp_tx_bq *bq)
594{
595 struct xdp_frame *frame = xdp_convert_buff_to_frame(xdp);
596
597 if (unlikely(!frame))
598 return -EOVERFLOW;
599
600 if (unlikely(bq->count == VETH_XDP_TX_BULK_SIZE))
601 veth_xdp_flush_bq(rq, bq);
602
603 bq->q[bq->count++] = frame;
604
605 return 0;
606}
607
608static struct xdp_frame *veth_xdp_rcv_one(struct veth_rq *rq,
609 struct xdp_frame *frame,
610 struct veth_xdp_tx_bq *bq,
611 struct veth_stats *stats)
612{
613 struct xdp_frame orig_frame;
614 struct bpf_prog *xdp_prog;
615
616 rcu_read_lock();
617 xdp_prog = rcu_dereference(rq->xdp_prog);
618 if (likely(xdp_prog)) {
619 struct veth_xdp_buff vxbuf;
620 struct xdp_buff *xdp = &vxbuf.xdp;
621 u32 act;
622
623 xdp_convert_frame_to_buff(frame, xdp);
624 xdp->rxq = &rq->xdp_rxq;
625 vxbuf.skb = NULL;
626
627 act = bpf_prog_run_xdp(prog: xdp_prog, xdp);
628
629 switch (act) {
630 case XDP_PASS:
631 if (xdp_update_frame_from_buff(xdp, xdp_frame: frame))
632 goto err_xdp;
633 break;
634 case XDP_TX:
635 orig_frame = *frame;
636 xdp->rxq->mem = frame->mem;
637 if (unlikely(veth_xdp_tx(rq, xdp, bq) < 0)) {
638 trace_xdp_exception(dev: rq->dev, xdp: xdp_prog, act);
639 frame = &orig_frame;
640 stats->rx_drops++;
641 goto err_xdp;
642 }
643 stats->xdp_tx++;
644 rcu_read_unlock();
645 goto xdp_xmit;
646 case XDP_REDIRECT:
647 orig_frame = *frame;
648 xdp->rxq->mem = frame->mem;
649 if (xdp_do_redirect(dev: rq->dev, xdp, prog: xdp_prog)) {
650 frame = &orig_frame;
651 stats->rx_drops++;
652 goto err_xdp;
653 }
654 stats->xdp_redirect++;
655 rcu_read_unlock();
656 goto xdp_xmit;
657 default:
658 bpf_warn_invalid_xdp_action(dev: rq->dev, prog: xdp_prog, act);
659 fallthrough;
660 case XDP_ABORTED:
661 trace_xdp_exception(dev: rq->dev, xdp: xdp_prog, act);
662 fallthrough;
663 case XDP_DROP:
664 stats->xdp_drops++;
665 goto err_xdp;
666 }
667 }
668 rcu_read_unlock();
669
670 return frame;
671err_xdp:
672 rcu_read_unlock();
673 xdp_return_frame(xdpf: frame);
674xdp_xmit:
675 return NULL;
676}
677
678/* frames array contains VETH_XDP_BATCH at most */
679static void veth_xdp_rcv_bulk_skb(struct veth_rq *rq, void **frames,
680 int n_xdpf, struct veth_xdp_tx_bq *bq,
681 struct veth_stats *stats)
682{
683 void *skbs[VETH_XDP_BATCH];
684 int i;
685
686 if (xdp_alloc_skb_bulk(skbs, n_skb: n_xdpf,
687 GFP_ATOMIC | __GFP_ZERO) < 0) {
688 for (i = 0; i < n_xdpf; i++)
689 xdp_return_frame(xdpf: frames[i]);
690 stats->rx_drops += n_xdpf;
691
692 return;
693 }
694
695 for (i = 0; i < n_xdpf; i++) {
696 struct sk_buff *skb = skbs[i];
697
698 skb = __xdp_build_skb_from_frame(xdpf: frames[i], skb,
699 dev: rq->dev);
700 if (!skb) {
701 xdp_return_frame(xdpf: frames[i]);
702 stats->rx_drops++;
703 continue;
704 }
705 napi_gro_receive(napi: &rq->xdp_napi, skb);
706 }
707}
708
709static void veth_xdp_get(struct xdp_buff *xdp)
710{
711 struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(xdp);
712 int i;
713
714 get_page(virt_to_page(xdp->data));
715 if (likely(!xdp_buff_has_frags(xdp)))
716 return;
717
718 for (i = 0; i < sinfo->nr_frags; i++)
719 __skb_frag_ref(frag: &sinfo->frags[i]);
720}
721
722static int veth_convert_skb_to_xdp_buff(struct veth_rq *rq,
723 struct xdp_buff *xdp,
724 struct sk_buff **pskb)
725{
726 struct sk_buff *skb = *pskb;
727 u32 frame_sz;
728
729 if (skb_shared(skb) || skb_head_is_locked(skb) ||
730 skb_shinfo(skb)->nr_frags ||
731 skb_headroom(skb) < XDP_PACKET_HEADROOM) {
732 if (skb_pp_cow_data(pool: rq->page_pool, pskb, XDP_PACKET_HEADROOM))
733 goto drop;
734
735 skb = *pskb;
736 }
737
738 /* SKB "head" area always have tailroom for skb_shared_info */
739 frame_sz = skb_end_pointer(skb) - skb->head;
740 frame_sz += SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
741 xdp_init_buff(xdp, frame_sz, rxq: &rq->xdp_rxq);
742 xdp_prepare_buff(xdp, hard_start: skb->head, headroom: skb_headroom(skb),
743 data_len: skb_headlen(skb), meta_valid: true);
744
745 if (skb_is_nonlinear(skb)) {
746 skb_shinfo(skb)->xdp_frags_size = skb->data_len;
747 xdp_buff_set_frags_flag(xdp);
748 } else {
749 xdp_buff_clear_frags_flag(xdp);
750 }
751 *pskb = skb;
752
753 return 0;
754drop:
755 consume_skb(skb);
756 *pskb = NULL;
757
758 return -ENOMEM;
759}
760
761static struct sk_buff *veth_xdp_rcv_skb(struct veth_rq *rq,
762 struct sk_buff *skb,
763 struct veth_xdp_tx_bq *bq,
764 struct veth_stats *stats)
765{
766 void *orig_data, *orig_data_end;
767 struct bpf_prog *xdp_prog;
768 struct veth_xdp_buff vxbuf;
769 struct xdp_buff *xdp = &vxbuf.xdp;
770 u32 act, metalen;
771 int off;
772
773 skb_prepare_for_gro(skb);
774
775 rcu_read_lock();
776 xdp_prog = rcu_dereference(rq->xdp_prog);
777 if (unlikely(!xdp_prog)) {
778 rcu_read_unlock();
779 goto out;
780 }
781
782 __skb_push(skb, len: skb->data - skb_mac_header(skb));
783 if (veth_convert_skb_to_xdp_buff(rq, xdp, pskb: &skb))
784 goto drop;
785 vxbuf.skb = skb;
786
787 orig_data = xdp->data;
788 orig_data_end = xdp->data_end;
789
790 act = bpf_prog_run_xdp(prog: xdp_prog, xdp);
791
792 switch (act) {
793 case XDP_PASS:
794 break;
795 case XDP_TX:
796 veth_xdp_get(xdp);
797 consume_skb(skb);
798 xdp->rxq->mem = rq->xdp_mem;
799 if (unlikely(veth_xdp_tx(rq, xdp, bq) < 0)) {
800 trace_xdp_exception(dev: rq->dev, xdp: xdp_prog, act);
801 stats->rx_drops++;
802 goto err_xdp;
803 }
804 stats->xdp_tx++;
805 rcu_read_unlock();
806 goto xdp_xmit;
807 case XDP_REDIRECT:
808 veth_xdp_get(xdp);
809 consume_skb(skb);
810 xdp->rxq->mem = rq->xdp_mem;
811 if (xdp_do_redirect(dev: rq->dev, xdp, prog: xdp_prog)) {
812 stats->rx_drops++;
813 goto err_xdp;
814 }
815 stats->xdp_redirect++;
816 rcu_read_unlock();
817 goto xdp_xmit;
818 default:
819 bpf_warn_invalid_xdp_action(dev: rq->dev, prog: xdp_prog, act);
820 fallthrough;
821 case XDP_ABORTED:
822 trace_xdp_exception(dev: rq->dev, xdp: xdp_prog, act);
823 fallthrough;
824 case XDP_DROP:
825 stats->xdp_drops++;
826 goto xdp_drop;
827 }
828 rcu_read_unlock();
829
830 /* check if bpf_xdp_adjust_head was used */
831 off = orig_data - xdp->data;
832 if (off > 0)
833 __skb_push(skb, len: off);
834 else if (off < 0)
835 __skb_pull(skb, len: -off);
836
837 skb_reset_mac_header(skb);
838
839 /* check if bpf_xdp_adjust_tail was used */
840 off = xdp->data_end - orig_data_end;
841 if (off != 0)
842 __skb_put(skb, len: off); /* positive on grow, negative on shrink */
843
844 /* XDP frag metadata (e.g. nr_frags) are updated in eBPF helpers
845 * (e.g. bpf_xdp_adjust_tail), we need to update data_len here.
846 */
847 if (xdp_buff_has_frags(xdp))
848 skb->data_len = skb_shinfo(skb)->xdp_frags_size;
849 else
850 skb->data_len = 0;
851
852 skb->protocol = eth_type_trans(skb, dev: rq->dev);
853
854 metalen = xdp->data - xdp->data_meta;
855 if (metalen)
856 skb_metadata_set(skb, meta_len: metalen);
857out:
858 return skb;
859drop:
860 stats->rx_drops++;
861xdp_drop:
862 rcu_read_unlock();
863 kfree_skb(skb);
864 return NULL;
865err_xdp:
866 rcu_read_unlock();
867 xdp_return_buff(xdp);
868xdp_xmit:
869 return NULL;
870}
871
872static int veth_xdp_rcv(struct veth_rq *rq, int budget,
873 struct veth_xdp_tx_bq *bq,
874 struct veth_stats *stats)
875{
876 int i, done = 0, n_xdpf = 0;
877 void *xdpf[VETH_XDP_BATCH];
878
879 for (i = 0; i < budget; i++) {
880 void *ptr = __ptr_ring_consume(r: &rq->xdp_ring);
881
882 if (!ptr)
883 break;
884
885 if (veth_is_xdp_frame(ptr)) {
886 /* ndo_xdp_xmit */
887 struct xdp_frame *frame = veth_ptr_to_xdp(ptr);
888
889 stats->xdp_bytes += xdp_get_frame_len(xdpf: frame);
890 frame = veth_xdp_rcv_one(rq, frame, bq, stats);
891 if (frame) {
892 /* XDP_PASS */
893 xdpf[n_xdpf++] = frame;
894 if (n_xdpf == VETH_XDP_BATCH) {
895 veth_xdp_rcv_bulk_skb(rq, frames: xdpf, n_xdpf,
896 bq, stats);
897 n_xdpf = 0;
898 }
899 }
900 } else {
901 /* ndo_start_xmit */
902 struct sk_buff *skb = ptr;
903
904 stats->xdp_bytes += skb->len;
905 skb = veth_xdp_rcv_skb(rq, skb, bq, stats);
906 if (skb) {
907 if (skb_shared(skb) || skb_unclone(skb, GFP_ATOMIC))
908 netif_receive_skb(skb);
909 else
910 napi_gro_receive(napi: &rq->xdp_napi, skb);
911 }
912 }
913 done++;
914 }
915
916 if (n_xdpf)
917 veth_xdp_rcv_bulk_skb(rq, frames: xdpf, n_xdpf, bq, stats);
918
919 u64_stats_update_begin(syncp: &rq->stats.syncp);
920 rq->stats.vs.xdp_redirect += stats->xdp_redirect;
921 rq->stats.vs.xdp_bytes += stats->xdp_bytes;
922 rq->stats.vs.xdp_drops += stats->xdp_drops;
923 rq->stats.vs.rx_drops += stats->rx_drops;
924 rq->stats.vs.xdp_packets += done;
925 u64_stats_update_end(syncp: &rq->stats.syncp);
926
927 return done;
928}
929
930static int veth_poll(struct napi_struct *napi, int budget)
931{
932 struct veth_rq *rq =
933 container_of(napi, struct veth_rq, xdp_napi);
934 struct veth_stats stats = {};
935 struct veth_xdp_tx_bq bq;
936 int done;
937
938 bq.count = 0;
939
940 xdp_set_return_frame_no_direct();
941 done = veth_xdp_rcv(rq, budget, bq: &bq, stats: &stats);
942
943 if (stats.xdp_redirect > 0)
944 xdp_do_flush();
945
946 if (done < budget && napi_complete_done(n: napi, work_done: done)) {
947 /* Write rx_notify_masked before reading ptr_ring */
948 smp_store_mb(rq->rx_notify_masked, false);
949 if (unlikely(!__ptr_ring_empty(&rq->xdp_ring))) {
950 if (napi_schedule_prep(n: &rq->xdp_napi)) {
951 WRITE_ONCE(rq->rx_notify_masked, true);
952 __napi_schedule(n: &rq->xdp_napi);
953 }
954 }
955 }
956
957 if (stats.xdp_tx > 0)
958 veth_xdp_flush(rq, bq: &bq);
959 xdp_clear_return_frame_no_direct();
960
961 return done;
962}
963
964static int veth_create_page_pool(struct veth_rq *rq)
965{
966 struct page_pool_params pp_params = {
967 .order = 0,
968 .pool_size = VETH_RING_SIZE,
969 .nid = NUMA_NO_NODE,
970 .dev = &rq->dev->dev,
971 };
972
973 rq->page_pool = page_pool_create(params: &pp_params);
974 if (IS_ERR(ptr: rq->page_pool)) {
975 int err = PTR_ERR(ptr: rq->page_pool);
976
977 rq->page_pool = NULL;
978 return err;
979 }
980
981 return 0;
982}
983
984static int __veth_napi_enable_range(struct net_device *dev, int start, int end)
985{
986 struct veth_priv *priv = netdev_priv(dev);
987 int err, i;
988
989 for (i = start; i < end; i++) {
990 err = veth_create_page_pool(rq: &priv->rq[i]);
991 if (err)
992 goto err_page_pool;
993 }
994
995 for (i = start; i < end; i++) {
996 struct veth_rq *rq = &priv->rq[i];
997
998 err = ptr_ring_init(r: &rq->xdp_ring, VETH_RING_SIZE, GFP_KERNEL);
999 if (err)
1000 goto err_xdp_ring;
1001 }
1002
1003 for (i = start; i < end; i++) {
1004 struct veth_rq *rq = &priv->rq[i];
1005
1006 napi_enable(n: &rq->xdp_napi);
1007 rcu_assign_pointer(priv->rq[i].napi, &priv->rq[i].xdp_napi);
1008 }
1009
1010 return 0;
1011
1012err_xdp_ring:
1013 for (i--; i >= start; i--)
1014 ptr_ring_cleanup(r: &priv->rq[i].xdp_ring, destroy: veth_ptr_free);
1015 i = end;
1016err_page_pool:
1017 for (i--; i >= start; i--) {
1018 page_pool_destroy(pool: priv->rq[i].page_pool);
1019 priv->rq[i].page_pool = NULL;
1020 }
1021
1022 return err;
1023}
1024
1025static int __veth_napi_enable(struct net_device *dev)
1026{
1027 return __veth_napi_enable_range(dev, start: 0, end: dev->real_num_rx_queues);
1028}
1029
1030static void veth_napi_del_range(struct net_device *dev, int start, int end)
1031{
1032 struct veth_priv *priv = netdev_priv(dev);
1033 int i;
1034
1035 for (i = start; i < end; i++) {
1036 struct veth_rq *rq = &priv->rq[i];
1037
1038 rcu_assign_pointer(priv->rq[i].napi, NULL);
1039 napi_disable(n: &rq->xdp_napi);
1040 __netif_napi_del(napi: &rq->xdp_napi);
1041 }
1042 synchronize_net();
1043
1044 for (i = start; i < end; i++) {
1045 struct veth_rq *rq = &priv->rq[i];
1046
1047 rq->rx_notify_masked = false;
1048 ptr_ring_cleanup(r: &rq->xdp_ring, destroy: veth_ptr_free);
1049 }
1050
1051 for (i = start; i < end; i++) {
1052 page_pool_destroy(pool: priv->rq[i].page_pool);
1053 priv->rq[i].page_pool = NULL;
1054 }
1055}
1056
1057static void veth_napi_del(struct net_device *dev)
1058{
1059 veth_napi_del_range(dev, start: 0, end: dev->real_num_rx_queues);
1060}
1061
1062static bool veth_gro_requested(const struct net_device *dev)
1063{
1064 return !!(dev->wanted_features & NETIF_F_GRO);
1065}
1066
1067static int veth_enable_xdp_range(struct net_device *dev, int start, int end,
1068 bool napi_already_on)
1069{
1070 struct veth_priv *priv = netdev_priv(dev);
1071 int err, i;
1072
1073 for (i = start; i < end; i++) {
1074 struct veth_rq *rq = &priv->rq[i];
1075
1076 if (!napi_already_on)
1077 netif_napi_add(dev, napi: &rq->xdp_napi, poll: veth_poll);
1078 err = xdp_rxq_info_reg(xdp_rxq: &rq->xdp_rxq, dev, queue_index: i, napi_id: rq->xdp_napi.napi_id);
1079 if (err < 0)
1080 goto err_rxq_reg;
1081
1082 err = xdp_rxq_info_reg_mem_model(xdp_rxq: &rq->xdp_rxq,
1083 type: MEM_TYPE_PAGE_SHARED,
1084 NULL);
1085 if (err < 0)
1086 goto err_reg_mem;
1087
1088 /* Save original mem info as it can be overwritten */
1089 rq->xdp_mem = rq->xdp_rxq.mem;
1090 }
1091 return 0;
1092
1093err_reg_mem:
1094 xdp_rxq_info_unreg(xdp_rxq: &priv->rq[i].xdp_rxq);
1095err_rxq_reg:
1096 for (i--; i >= start; i--) {
1097 struct veth_rq *rq = &priv->rq[i];
1098
1099 xdp_rxq_info_unreg(xdp_rxq: &rq->xdp_rxq);
1100 if (!napi_already_on)
1101 netif_napi_del(napi: &rq->xdp_napi);
1102 }
1103
1104 return err;
1105}
1106
1107static void veth_disable_xdp_range(struct net_device *dev, int start, int end,
1108 bool delete_napi)
1109{
1110 struct veth_priv *priv = netdev_priv(dev);
1111 int i;
1112
1113 for (i = start; i < end; i++) {
1114 struct veth_rq *rq = &priv->rq[i];
1115
1116 rq->xdp_rxq.mem = rq->xdp_mem;
1117 xdp_rxq_info_unreg(xdp_rxq: &rq->xdp_rxq);
1118
1119 if (delete_napi)
1120 netif_napi_del(napi: &rq->xdp_napi);
1121 }
1122}
1123
1124static int veth_enable_xdp(struct net_device *dev)
1125{
1126 bool napi_already_on = veth_gro_requested(dev) && (dev->flags & IFF_UP);
1127 struct veth_priv *priv = netdev_priv(dev);
1128 int err, i;
1129
1130 if (!xdp_rxq_info_is_reg(xdp_rxq: &priv->rq[0].xdp_rxq)) {
1131 err = veth_enable_xdp_range(dev, start: 0, end: dev->real_num_rx_queues, napi_already_on);
1132 if (err)
1133 return err;
1134
1135 if (!napi_already_on) {
1136 err = __veth_napi_enable(dev);
1137 if (err) {
1138 veth_disable_xdp_range(dev, start: 0, end: dev->real_num_rx_queues, delete_napi: true);
1139 return err;
1140 }
1141 }
1142 }
1143
1144 for (i = 0; i < dev->real_num_rx_queues; i++) {
1145 rcu_assign_pointer(priv->rq[i].xdp_prog, priv->_xdp_prog);
1146 rcu_assign_pointer(priv->rq[i].napi, &priv->rq[i].xdp_napi);
1147 }
1148
1149 return 0;
1150}
1151
1152static void veth_disable_xdp(struct net_device *dev)
1153{
1154 struct veth_priv *priv = netdev_priv(dev);
1155 int i;
1156
1157 for (i = 0; i < dev->real_num_rx_queues; i++)
1158 rcu_assign_pointer(priv->rq[i].xdp_prog, NULL);
1159
1160 if (!netif_running(dev) || !veth_gro_requested(dev))
1161 veth_napi_del(dev);
1162
1163 veth_disable_xdp_range(dev, start: 0, end: dev->real_num_rx_queues, delete_napi: false);
1164}
1165
1166static int veth_napi_enable_range(struct net_device *dev, int start, int end)
1167{
1168 struct veth_priv *priv = netdev_priv(dev);
1169 int err, i;
1170
1171 for (i = start; i < end; i++) {
1172 struct veth_rq *rq = &priv->rq[i];
1173
1174 netif_napi_add(dev, napi: &rq->xdp_napi, poll: veth_poll);
1175 }
1176
1177 err = __veth_napi_enable_range(dev, start, end);
1178 if (err) {
1179 for (i = start; i < end; i++) {
1180 struct veth_rq *rq = &priv->rq[i];
1181
1182 netif_napi_del(napi: &rq->xdp_napi);
1183 }
1184 return err;
1185 }
1186 return err;
1187}
1188
1189static int veth_napi_enable(struct net_device *dev)
1190{
1191 return veth_napi_enable_range(dev, start: 0, end: dev->real_num_rx_queues);
1192}
1193
1194static void veth_disable_range_safe(struct net_device *dev, int start, int end)
1195{
1196 struct veth_priv *priv = netdev_priv(dev);
1197
1198 if (start >= end)
1199 return;
1200
1201 if (priv->_xdp_prog) {
1202 veth_napi_del_range(dev, start, end);
1203 veth_disable_xdp_range(dev, start, end, delete_napi: false);
1204 } else if (veth_gro_requested(dev)) {
1205 veth_napi_del_range(dev, start, end);
1206 }
1207}
1208
1209static int veth_enable_range_safe(struct net_device *dev, int start, int end)
1210{
1211 struct veth_priv *priv = netdev_priv(dev);
1212 int err;
1213
1214 if (start >= end)
1215 return 0;
1216
1217 if (priv->_xdp_prog) {
1218 /* these channels are freshly initialized, napi is not on there even
1219 * when GRO is requeste
1220 */
1221 err = veth_enable_xdp_range(dev, start, end, napi_already_on: false);
1222 if (err)
1223 return err;
1224
1225 err = __veth_napi_enable_range(dev, start, end);
1226 if (err) {
1227 /* on error always delete the newly added napis */
1228 veth_disable_xdp_range(dev, start, end, delete_napi: true);
1229 return err;
1230 }
1231 } else if (veth_gro_requested(dev)) {
1232 return veth_napi_enable_range(dev, start, end);
1233 }
1234 return 0;
1235}
1236
1237static void veth_set_xdp_features(struct net_device *dev)
1238{
1239 struct veth_priv *priv = netdev_priv(dev);
1240 struct net_device *peer;
1241
1242 peer = rtnl_dereference(priv->peer);
1243 if (peer && peer->real_num_tx_queues <= dev->real_num_rx_queues) {
1244 struct veth_priv *priv_peer = netdev_priv(dev: peer);
1245 xdp_features_t val = NETDEV_XDP_ACT_BASIC |
1246 NETDEV_XDP_ACT_REDIRECT |
1247 NETDEV_XDP_ACT_RX_SG;
1248
1249 if (priv_peer->_xdp_prog || veth_gro_requested(dev: peer))
1250 val |= NETDEV_XDP_ACT_NDO_XMIT |
1251 NETDEV_XDP_ACT_NDO_XMIT_SG;
1252 xdp_set_features_flag(dev, val);
1253 } else {
1254 xdp_clear_features_flag(dev);
1255 }
1256}
1257
1258static int veth_set_channels(struct net_device *dev,
1259 struct ethtool_channels *ch)
1260{
1261 struct veth_priv *priv = netdev_priv(dev);
1262 unsigned int old_rx_count, new_rx_count;
1263 struct veth_priv *peer_priv;
1264 struct net_device *peer;
1265 int err;
1266
1267 /* sanity check. Upper bounds are already enforced by the caller */
1268 if (!ch->rx_count || !ch->tx_count)
1269 return -EINVAL;
1270
1271 /* avoid braking XDP, if that is enabled */
1272 peer = rtnl_dereference(priv->peer);
1273 peer_priv = peer ? netdev_priv(dev: peer) : NULL;
1274 if (priv->_xdp_prog && peer && ch->rx_count < peer->real_num_tx_queues)
1275 return -EINVAL;
1276
1277 if (peer && peer_priv && peer_priv->_xdp_prog && ch->tx_count > peer->real_num_rx_queues)
1278 return -EINVAL;
1279
1280 old_rx_count = dev->real_num_rx_queues;
1281 new_rx_count = ch->rx_count;
1282 if (netif_running(dev)) {
1283 /* turn device off */
1284 netif_carrier_off(dev);
1285 if (peer)
1286 netif_carrier_off(dev: peer);
1287
1288 /* try to allocate new resurces, as needed*/
1289 err = veth_enable_range_safe(dev, start: old_rx_count, end: new_rx_count);
1290 if (err)
1291 goto out;
1292 }
1293
1294 err = netif_set_real_num_rx_queues(dev, rxq: ch->rx_count);
1295 if (err)
1296 goto revert;
1297
1298 err = netif_set_real_num_tx_queues(dev, txq: ch->tx_count);
1299 if (err) {
1300 int err2 = netif_set_real_num_rx_queues(dev, rxq: old_rx_count);
1301
1302 /* this error condition could happen only if rx and tx change
1303 * in opposite directions (e.g. tx nr raises, rx nr decreases)
1304 * and we can't do anything to fully restore the original
1305 * status
1306 */
1307 if (err2)
1308 pr_warn("Can't restore rx queues config %d -> %d %d",
1309 new_rx_count, old_rx_count, err2);
1310 else
1311 goto revert;
1312 }
1313
1314out:
1315 if (netif_running(dev)) {
1316 /* note that we need to swap the arguments WRT the enable part
1317 * to identify the range we have to disable
1318 */
1319 veth_disable_range_safe(dev, start: new_rx_count, end: old_rx_count);
1320 netif_carrier_on(dev);
1321 if (peer)
1322 netif_carrier_on(dev: peer);
1323 }
1324
1325 /* update XDP supported features */
1326 veth_set_xdp_features(dev);
1327 if (peer)
1328 veth_set_xdp_features(dev: peer);
1329
1330 return err;
1331
1332revert:
1333 new_rx_count = old_rx_count;
1334 old_rx_count = ch->rx_count;
1335 goto out;
1336}
1337
1338static int veth_open(struct net_device *dev)
1339{
1340 struct veth_priv *priv = netdev_priv(dev);
1341 struct net_device *peer = rtnl_dereference(priv->peer);
1342 int err;
1343
1344 if (!peer)
1345 return -ENOTCONN;
1346
1347 if (priv->_xdp_prog) {
1348 err = veth_enable_xdp(dev);
1349 if (err)
1350 return err;
1351 } else if (veth_gro_requested(dev)) {
1352 err = veth_napi_enable(dev);
1353 if (err)
1354 return err;
1355 }
1356
1357 if (peer->flags & IFF_UP) {
1358 netif_carrier_on(dev);
1359 netif_carrier_on(dev: peer);
1360 }
1361
1362 veth_set_xdp_features(dev);
1363
1364 return 0;
1365}
1366
1367static int veth_close(struct net_device *dev)
1368{
1369 struct veth_priv *priv = netdev_priv(dev);
1370 struct net_device *peer = rtnl_dereference(priv->peer);
1371
1372 netif_carrier_off(dev);
1373 if (peer)
1374 netif_carrier_off(dev: peer);
1375
1376 if (priv->_xdp_prog)
1377 veth_disable_xdp(dev);
1378 else if (veth_gro_requested(dev))
1379 veth_napi_del(dev);
1380
1381 return 0;
1382}
1383
1384static int is_valid_veth_mtu(int mtu)
1385{
1386 return mtu >= ETH_MIN_MTU && mtu <= ETH_MAX_MTU;
1387}
1388
1389static int veth_alloc_queues(struct net_device *dev)
1390{
1391 struct veth_priv *priv = netdev_priv(dev);
1392 int i;
1393
1394 priv->rq = kvcalloc(n: dev->num_rx_queues, size: sizeof(*priv->rq),
1395 GFP_KERNEL_ACCOUNT | __GFP_RETRY_MAYFAIL);
1396 if (!priv->rq)
1397 return -ENOMEM;
1398
1399 for (i = 0; i < dev->num_rx_queues; i++) {
1400 priv->rq[i].dev = dev;
1401 u64_stats_init(syncp: &priv->rq[i].stats.syncp);
1402 }
1403
1404 return 0;
1405}
1406
1407static void veth_free_queues(struct net_device *dev)
1408{
1409 struct veth_priv *priv = netdev_priv(dev);
1410
1411 kvfree(addr: priv->rq);
1412}
1413
1414static int veth_dev_init(struct net_device *dev)
1415{
1416 netdev_lockdep_set_classes(dev);
1417 return veth_alloc_queues(dev);
1418}
1419
1420static void veth_dev_free(struct net_device *dev)
1421{
1422 veth_free_queues(dev);
1423}
1424
1425#ifdef CONFIG_NET_POLL_CONTROLLER
1426static void veth_poll_controller(struct net_device *dev)
1427{
1428 /* veth only receives frames when its peer sends one
1429 * Since it has nothing to do with disabling irqs, we are guaranteed
1430 * never to have pending data when we poll for it so
1431 * there is nothing to do here.
1432 *
1433 * We need this though so netpoll recognizes us as an interface that
1434 * supports polling, which enables bridge devices in virt setups to
1435 * still use netconsole
1436 */
1437}
1438#endif /* CONFIG_NET_POLL_CONTROLLER */
1439
1440static int veth_get_iflink(const struct net_device *dev)
1441{
1442 struct veth_priv *priv = netdev_priv(dev);
1443 struct net_device *peer;
1444 int iflink;
1445
1446 rcu_read_lock();
1447 peer = rcu_dereference(priv->peer);
1448 iflink = peer ? READ_ONCE(peer->ifindex) : 0;
1449 rcu_read_unlock();
1450
1451 return iflink;
1452}
1453
1454static netdev_features_t veth_fix_features(struct net_device *dev,
1455 netdev_features_t features)
1456{
1457 struct veth_priv *priv = netdev_priv(dev);
1458 struct net_device *peer;
1459
1460 peer = rtnl_dereference(priv->peer);
1461 if (peer) {
1462 struct veth_priv *peer_priv = netdev_priv(dev: peer);
1463
1464 if (peer_priv->_xdp_prog)
1465 features &= ~NETIF_F_GSO_SOFTWARE;
1466 }
1467
1468 return features;
1469}
1470
1471static int veth_set_features(struct net_device *dev,
1472 netdev_features_t features)
1473{
1474 netdev_features_t changed = features ^ dev->features;
1475 struct veth_priv *priv = netdev_priv(dev);
1476 struct net_device *peer;
1477 int err;
1478
1479 if (!(changed & NETIF_F_GRO) || !(dev->flags & IFF_UP) || priv->_xdp_prog)
1480 return 0;
1481
1482 peer = rtnl_dereference(priv->peer);
1483 if (features & NETIF_F_GRO) {
1484 err = veth_napi_enable(dev);
1485 if (err)
1486 return err;
1487
1488 if (peer)
1489 xdp_features_set_redirect_target(dev: peer, support_sg: true);
1490 } else {
1491 if (peer)
1492 xdp_features_clear_redirect_target(dev: peer);
1493 veth_napi_del(dev);
1494 }
1495 return 0;
1496}
1497
1498static void veth_set_rx_headroom(struct net_device *dev, int new_hr)
1499{
1500 struct veth_priv *peer_priv, *priv = netdev_priv(dev);
1501 struct net_device *peer;
1502
1503 if (new_hr < 0)
1504 new_hr = 0;
1505
1506 rcu_read_lock();
1507 peer = rcu_dereference(priv->peer);
1508 if (unlikely(!peer))
1509 goto out;
1510
1511 peer_priv = netdev_priv(dev: peer);
1512 priv->requested_headroom = new_hr;
1513 new_hr = max(priv->requested_headroom, peer_priv->requested_headroom);
1514 dev->needed_headroom = new_hr;
1515 peer->needed_headroom = new_hr;
1516
1517out:
1518 rcu_read_unlock();
1519}
1520
1521static int veth_xdp_set(struct net_device *dev, struct bpf_prog *prog,
1522 struct netlink_ext_ack *extack)
1523{
1524 struct veth_priv *priv = netdev_priv(dev);
1525 struct bpf_prog *old_prog;
1526 struct net_device *peer;
1527 unsigned int max_mtu;
1528 int err;
1529
1530 old_prog = priv->_xdp_prog;
1531 priv->_xdp_prog = prog;
1532 peer = rtnl_dereference(priv->peer);
1533
1534 if (prog) {
1535 if (!peer) {
1536 NL_SET_ERR_MSG_MOD(extack, "Cannot set XDP when peer is detached");
1537 err = -ENOTCONN;
1538 goto err;
1539 }
1540
1541 max_mtu = SKB_WITH_OVERHEAD(PAGE_SIZE - VETH_XDP_HEADROOM) -
1542 peer->hard_header_len;
1543 /* Allow increasing the max_mtu if the program supports
1544 * XDP fragments.
1545 */
1546 if (prog->aux->xdp_has_frags)
1547 max_mtu += PAGE_SIZE * MAX_SKB_FRAGS;
1548
1549 if (peer->mtu > max_mtu) {
1550 NL_SET_ERR_MSG_MOD(extack, "Peer MTU is too large to set XDP");
1551 err = -ERANGE;
1552 goto err;
1553 }
1554
1555 if (dev->real_num_rx_queues < peer->real_num_tx_queues) {
1556 NL_SET_ERR_MSG_MOD(extack, "XDP expects number of rx queues not less than peer tx queues");
1557 err = -ENOSPC;
1558 goto err;
1559 }
1560
1561 if (dev->flags & IFF_UP) {
1562 err = veth_enable_xdp(dev);
1563 if (err) {
1564 NL_SET_ERR_MSG_MOD(extack, "Setup for XDP failed");
1565 goto err;
1566 }
1567 }
1568
1569 if (!old_prog) {
1570 peer->hw_features &= ~NETIF_F_GSO_SOFTWARE;
1571 peer->max_mtu = max_mtu;
1572 }
1573
1574 xdp_features_set_redirect_target(dev: peer, support_sg: true);
1575 }
1576
1577 if (old_prog) {
1578 if (!prog) {
1579 if (peer && !veth_gro_requested(dev))
1580 xdp_features_clear_redirect_target(dev: peer);
1581
1582 if (dev->flags & IFF_UP)
1583 veth_disable_xdp(dev);
1584
1585 if (peer) {
1586 peer->hw_features |= NETIF_F_GSO_SOFTWARE;
1587 peer->max_mtu = ETH_MAX_MTU;
1588 }
1589 }
1590 bpf_prog_put(prog: old_prog);
1591 }
1592
1593 if ((!!old_prog ^ !!prog) && peer)
1594 netdev_update_features(dev: peer);
1595
1596 return 0;
1597err:
1598 priv->_xdp_prog = old_prog;
1599
1600 return err;
1601}
1602
1603static int veth_xdp(struct net_device *dev, struct netdev_bpf *xdp)
1604{
1605 switch (xdp->command) {
1606 case XDP_SETUP_PROG:
1607 return veth_xdp_set(dev, prog: xdp->prog, extack: xdp->extack);
1608 default:
1609 return -EINVAL;
1610 }
1611}
1612
1613static int veth_xdp_rx_timestamp(const struct xdp_md *ctx, u64 *timestamp)
1614{
1615 struct veth_xdp_buff *_ctx = (void *)ctx;
1616
1617 if (!_ctx->skb)
1618 return -ENODATA;
1619
1620 *timestamp = skb_hwtstamps(skb: _ctx->skb)->hwtstamp;
1621 return 0;
1622}
1623
1624static int veth_xdp_rx_hash(const struct xdp_md *ctx, u32 *hash,
1625 enum xdp_rss_hash_type *rss_type)
1626{
1627 struct veth_xdp_buff *_ctx = (void *)ctx;
1628 struct sk_buff *skb = _ctx->skb;
1629
1630 if (!skb)
1631 return -ENODATA;
1632
1633 *hash = skb_get_hash(skb);
1634 *rss_type = skb->l4_hash ? XDP_RSS_TYPE_L4_ANY : XDP_RSS_TYPE_NONE;
1635
1636 return 0;
1637}
1638
1639static int veth_xdp_rx_vlan_tag(const struct xdp_md *ctx, __be16 *vlan_proto,
1640 u16 *vlan_tci)
1641{
1642 const struct veth_xdp_buff *_ctx = (void *)ctx;
1643 const struct sk_buff *skb = _ctx->skb;
1644 int err;
1645
1646 if (!skb)
1647 return -ENODATA;
1648
1649 err = __vlan_hwaccel_get_tag(skb, vlan_tci);
1650 if (err)
1651 return err;
1652
1653 *vlan_proto = skb->vlan_proto;
1654 return err;
1655}
1656
1657static const struct net_device_ops veth_netdev_ops = {
1658 .ndo_init = veth_dev_init,
1659 .ndo_open = veth_open,
1660 .ndo_stop = veth_close,
1661 .ndo_start_xmit = veth_xmit,
1662 .ndo_get_stats64 = veth_get_stats64,
1663 .ndo_set_rx_mode = veth_set_multicast_list,
1664 .ndo_set_mac_address = eth_mac_addr,
1665#ifdef CONFIG_NET_POLL_CONTROLLER
1666 .ndo_poll_controller = veth_poll_controller,
1667#endif
1668 .ndo_get_iflink = veth_get_iflink,
1669 .ndo_fix_features = veth_fix_features,
1670 .ndo_set_features = veth_set_features,
1671 .ndo_features_check = passthru_features_check,
1672 .ndo_set_rx_headroom = veth_set_rx_headroom,
1673 .ndo_bpf = veth_xdp,
1674 .ndo_xdp_xmit = veth_ndo_xdp_xmit,
1675 .ndo_get_peer_dev = veth_peer_dev,
1676};
1677
1678static const struct xdp_metadata_ops veth_xdp_metadata_ops = {
1679 .xmo_rx_timestamp = veth_xdp_rx_timestamp,
1680 .xmo_rx_hash = veth_xdp_rx_hash,
1681 .xmo_rx_vlan_tag = veth_xdp_rx_vlan_tag,
1682};
1683
1684#define VETH_FEATURES (NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HW_CSUM | \
1685 NETIF_F_RXCSUM | NETIF_F_SCTP_CRC | NETIF_F_HIGHDMA | \
1686 NETIF_F_GSO_SOFTWARE | NETIF_F_GSO_ENCAP_ALL | \
1687 NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_CTAG_RX | \
1688 NETIF_F_HW_VLAN_STAG_TX | NETIF_F_HW_VLAN_STAG_RX )
1689
1690static void veth_setup(struct net_device *dev)
1691{
1692 ether_setup(dev);
1693
1694 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1695 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1696 dev->priv_flags |= IFF_NO_QUEUE;
1697 dev->priv_flags |= IFF_PHONY_HEADROOM;
1698
1699 dev->netdev_ops = &veth_netdev_ops;
1700 dev->xdp_metadata_ops = &veth_xdp_metadata_ops;
1701 dev->ethtool_ops = &veth_ethtool_ops;
1702 dev->features |= NETIF_F_LLTX;
1703 dev->features |= VETH_FEATURES;
1704 dev->vlan_features = dev->features &
1705 ~(NETIF_F_HW_VLAN_CTAG_TX |
1706 NETIF_F_HW_VLAN_STAG_TX |
1707 NETIF_F_HW_VLAN_CTAG_RX |
1708 NETIF_F_HW_VLAN_STAG_RX);
1709 dev->needs_free_netdev = true;
1710 dev->priv_destructor = veth_dev_free;
1711 dev->pcpu_stat_type = NETDEV_PCPU_STAT_TSTATS;
1712 dev->max_mtu = ETH_MAX_MTU;
1713
1714 dev->hw_features = VETH_FEATURES;
1715 dev->hw_enc_features = VETH_FEATURES;
1716 dev->mpls_features = NETIF_F_HW_CSUM | NETIF_F_GSO_SOFTWARE;
1717 netif_set_tso_max_size(dev, GSO_MAX_SIZE);
1718}
1719
1720/*
1721 * netlink interface
1722 */
1723
1724static int veth_validate(struct nlattr *tb[], struct nlattr *data[],
1725 struct netlink_ext_ack *extack)
1726{
1727 if (tb[IFLA_ADDRESS]) {
1728 if (nla_len(nla: tb[IFLA_ADDRESS]) != ETH_ALEN)
1729 return -EINVAL;
1730 if (!is_valid_ether_addr(addr: nla_data(nla: tb[IFLA_ADDRESS])))
1731 return -EADDRNOTAVAIL;
1732 }
1733 if (tb[IFLA_MTU]) {
1734 if (!is_valid_veth_mtu(mtu: nla_get_u32(nla: tb[IFLA_MTU])))
1735 return -EINVAL;
1736 }
1737 return 0;
1738}
1739
1740static struct rtnl_link_ops veth_link_ops;
1741
1742static void veth_disable_gro(struct net_device *dev)
1743{
1744 dev->features &= ~NETIF_F_GRO;
1745 dev->wanted_features &= ~NETIF_F_GRO;
1746 netdev_update_features(dev);
1747}
1748
1749static int veth_init_queues(struct net_device *dev, struct nlattr *tb[])
1750{
1751 int err;
1752
1753 if (!tb[IFLA_NUM_TX_QUEUES] && dev->num_tx_queues > 1) {
1754 err = netif_set_real_num_tx_queues(dev, txq: 1);
1755 if (err)
1756 return err;
1757 }
1758 if (!tb[IFLA_NUM_RX_QUEUES] && dev->num_rx_queues > 1) {
1759 err = netif_set_real_num_rx_queues(dev, rxq: 1);
1760 if (err)
1761 return err;
1762 }
1763 return 0;
1764}
1765
1766static int veth_newlink(struct net *src_net, struct net_device *dev,
1767 struct nlattr *tb[], struct nlattr *data[],
1768 struct netlink_ext_ack *extack)
1769{
1770 int err;
1771 struct net_device *peer;
1772 struct veth_priv *priv;
1773 char ifname[IFNAMSIZ];
1774 struct nlattr *peer_tb[IFLA_MAX + 1], **tbp;
1775 unsigned char name_assign_type;
1776 struct ifinfomsg *ifmp;
1777 struct net *net;
1778
1779 /*
1780 * create and register peer first
1781 */
1782 if (data != NULL && data[VETH_INFO_PEER] != NULL) {
1783 struct nlattr *nla_peer;
1784
1785 nla_peer = data[VETH_INFO_PEER];
1786 ifmp = nla_data(nla: nla_peer);
1787 err = rtnl_nla_parse_ifinfomsg(tb: peer_tb, nla_peer, exterr: extack);
1788 if (err < 0)
1789 return err;
1790
1791 err = veth_validate(tb: peer_tb, NULL, extack);
1792 if (err < 0)
1793 return err;
1794
1795 tbp = peer_tb;
1796 } else {
1797 ifmp = NULL;
1798 tbp = tb;
1799 }
1800
1801 if (ifmp && tbp[IFLA_IFNAME]) {
1802 nla_strscpy(dst: ifname, nla: tbp[IFLA_IFNAME], IFNAMSIZ);
1803 name_assign_type = NET_NAME_USER;
1804 } else {
1805 snprintf(buf: ifname, IFNAMSIZ, DRV_NAME "%%d");
1806 name_assign_type = NET_NAME_ENUM;
1807 }
1808
1809 net = rtnl_link_get_net(src_net, tb: tbp);
1810 if (IS_ERR(ptr: net))
1811 return PTR_ERR(ptr: net);
1812
1813 peer = rtnl_create_link(net, ifname, name_assign_type,
1814 ops: &veth_link_ops, tb: tbp, extack);
1815 if (IS_ERR(ptr: peer)) {
1816 put_net(net);
1817 return PTR_ERR(ptr: peer);
1818 }
1819
1820 if (!ifmp || !tbp[IFLA_ADDRESS])
1821 eth_hw_addr_random(dev: peer);
1822
1823 if (ifmp && (dev->ifindex != 0))
1824 peer->ifindex = ifmp->ifi_index;
1825
1826 netif_inherit_tso_max(to: peer, from: dev);
1827
1828 err = register_netdevice(dev: peer);
1829 put_net(net);
1830 net = NULL;
1831 if (err < 0)
1832 goto err_register_peer;
1833
1834 /* keep GRO disabled by default to be consistent with the established
1835 * veth behavior
1836 */
1837 veth_disable_gro(dev: peer);
1838 netif_carrier_off(dev: peer);
1839
1840 err = rtnl_configure_link(dev: peer, ifm: ifmp, portid: 0, NULL);
1841 if (err < 0)
1842 goto err_configure_peer;
1843
1844 /*
1845 * register dev last
1846 *
1847 * note, that since we've registered new device the dev's name
1848 * should be re-allocated
1849 */
1850
1851 if (tb[IFLA_ADDRESS] == NULL)
1852 eth_hw_addr_random(dev);
1853
1854 if (tb[IFLA_IFNAME])
1855 nla_strscpy(dst: dev->name, nla: tb[IFLA_IFNAME], IFNAMSIZ);
1856 else
1857 snprintf(buf: dev->name, IFNAMSIZ, DRV_NAME "%%d");
1858
1859 err = register_netdevice(dev);
1860 if (err < 0)
1861 goto err_register_dev;
1862
1863 netif_carrier_off(dev);
1864
1865 /*
1866 * tie the deviced together
1867 */
1868
1869 priv = netdev_priv(dev);
1870 rcu_assign_pointer(priv->peer, peer);
1871 err = veth_init_queues(dev, tb);
1872 if (err)
1873 goto err_queues;
1874
1875 priv = netdev_priv(dev: peer);
1876 rcu_assign_pointer(priv->peer, dev);
1877 err = veth_init_queues(dev: peer, tb);
1878 if (err)
1879 goto err_queues;
1880
1881 veth_disable_gro(dev);
1882 /* update XDP supported features */
1883 veth_set_xdp_features(dev);
1884 veth_set_xdp_features(dev: peer);
1885
1886 return 0;
1887
1888err_queues:
1889 unregister_netdevice(dev);
1890err_register_dev:
1891 /* nothing to do */
1892err_configure_peer:
1893 unregister_netdevice(dev: peer);
1894 return err;
1895
1896err_register_peer:
1897 free_netdev(dev: peer);
1898 return err;
1899}
1900
1901static void veth_dellink(struct net_device *dev, struct list_head *head)
1902{
1903 struct veth_priv *priv;
1904 struct net_device *peer;
1905
1906 priv = netdev_priv(dev);
1907 peer = rtnl_dereference(priv->peer);
1908
1909 /* Note : dellink() is called from default_device_exit_batch(),
1910 * before a rcu_synchronize() point. The devices are guaranteed
1911 * not being freed before one RCU grace period.
1912 */
1913 RCU_INIT_POINTER(priv->peer, NULL);
1914 unregister_netdevice_queue(dev, head);
1915
1916 if (peer) {
1917 priv = netdev_priv(dev: peer);
1918 RCU_INIT_POINTER(priv->peer, NULL);
1919 unregister_netdevice_queue(dev: peer, head);
1920 }
1921}
1922
1923static const struct nla_policy veth_policy[VETH_INFO_MAX + 1] = {
1924 [VETH_INFO_PEER] = { .len = sizeof(struct ifinfomsg) },
1925};
1926
1927static struct net *veth_get_link_net(const struct net_device *dev)
1928{
1929 struct veth_priv *priv = netdev_priv(dev);
1930 struct net_device *peer = rtnl_dereference(priv->peer);
1931
1932 return peer ? dev_net(dev: peer) : dev_net(dev);
1933}
1934
1935static unsigned int veth_get_num_queues(void)
1936{
1937 /* enforce the same queue limit as rtnl_create_link */
1938 int queues = num_possible_cpus();
1939
1940 if (queues > 4096)
1941 queues = 4096;
1942 return queues;
1943}
1944
1945static struct rtnl_link_ops veth_link_ops = {
1946 .kind = DRV_NAME,
1947 .priv_size = sizeof(struct veth_priv),
1948 .setup = veth_setup,
1949 .validate = veth_validate,
1950 .newlink = veth_newlink,
1951 .dellink = veth_dellink,
1952 .policy = veth_policy,
1953 .maxtype = VETH_INFO_MAX,
1954 .get_link_net = veth_get_link_net,
1955 .get_num_tx_queues = veth_get_num_queues,
1956 .get_num_rx_queues = veth_get_num_queues,
1957};
1958
1959/*
1960 * init/fini
1961 */
1962
1963static __init int veth_init(void)
1964{
1965 return rtnl_link_register(ops: &veth_link_ops);
1966}
1967
1968static __exit void veth_exit(void)
1969{
1970 rtnl_link_unregister(ops: &veth_link_ops);
1971}
1972
1973module_init(veth_init);
1974module_exit(veth_exit);
1975
1976MODULE_DESCRIPTION("Virtual Ethernet Tunnel");
1977MODULE_LICENSE("GPL v2");
1978MODULE_ALIAS_RTNL_LINK(DRV_NAME);
1979

source code of linux/drivers/net/veth.c