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
41 struct 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
54 struct veth_rq_stats {
55 struct veth_stats vs;
56 struct u64_stats_sync syncp;
57 };
58
59 struct 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
72 struct 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
80 struct 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
89 struct 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
96 static 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
108 static 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
115 static struct {
116 const char string[ETH_GSTRING_LEN];
117 } ethtool_stats_keys[] = {
118 { "peer_ifindex" },
119 };
120
121 struct veth_xdp_buff {
122 struct xdp_buff xdp;
123 struct sk_buff *skb;
124 };
125
veth_get_link_ksettings(struct net_device * dev,struct ethtool_link_ksettings * cmd)126 static 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
veth_get_drvinfo(struct net_device * dev,struct ethtool_drvinfo * info)136 static 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
veth_get_strings(struct net_device * dev,u32 stringset,u8 * buf)142 static 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, ðtool_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(&p, "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(&p, "tx_queue_%u_%.18s",
159 i, veth_tq_stats_desc[j].desc);
160
161 page_pool_ethtool_stats_get_strings(p);
162 break;
163 }
164 }
165
veth_get_sset_count(struct net_device * dev,int sset)166 static 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
veth_get_page_pool_stats(struct net_device * dev,u64 * data)179 static 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(priv->rq[i].page_pool, &pp_stats);
190 }
191 page_pool_ethtool_stats_get(data, &pp_stats);
192 #endif /* CONFIG_PAGE_POOL_STATS */
193 }
194
veth_get_ethtool_stats(struct net_device * dev,struct ethtool_stats * stats,u64 * data)195 static 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(&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(&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(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(&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(&rq_stats->syncp, start));
239 }
240 pp_idx = idx + dev->real_num_tx_queues * VETH_TQ_STATS_LEN;
241
242 page_pool_stats:
243 veth_get_page_pool_stats(dev, &data[pp_idx]);
244 }
245
veth_get_channels(struct net_device * dev,struct ethtool_channels * channels)246 static 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
255 static int veth_set_channels(struct net_device *dev,
256 struct ethtool_channels *ch);
257
258 static 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
veth_is_xdp_frame(void * ptr)272 static bool veth_is_xdp_frame(void *ptr)
273 {
274 return (unsigned long)ptr & VETH_XDP_FLAG;
275 }
276
veth_ptr_to_xdp(void * ptr)277 static struct xdp_frame *veth_ptr_to_xdp(void *ptr)
278 {
279 return (void *)((unsigned long)ptr & ~VETH_XDP_FLAG);
280 }
281
veth_xdp_to_ptr(struct xdp_frame * xdp)282 static void *veth_xdp_to_ptr(struct xdp_frame *xdp)
283 {
284 return (void *)((unsigned long)xdp | VETH_XDP_FLAG);
285 }
286
veth_ptr_free(void * ptr)287 static void veth_ptr_free(void *ptr)
288 {
289 if (veth_is_xdp_frame(ptr))
290 xdp_return_frame(veth_ptr_to_xdp(ptr));
291 else
292 kfree_skb(ptr);
293 }
294
__veth_xdp_flush(struct veth_rq * rq)295 static 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(&rq->xdp_napi)) {
301 WRITE_ONCE(rq->rx_notify_masked, true);
302 __napi_schedule(&rq->xdp_napi);
303 }
304 }
305
veth_xdp_rx(struct veth_rq * rq,struct sk_buff * skb)306 static 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
veth_forward_skb(struct net_device * dev,struct sk_buff * skb,struct veth_rq * rq,bool xdp)316 static 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 */
veth_skb_is_eligible_for_gro(const struct net_device * dev,const struct net_device * rcv,const struct sk_buff * skb)334 static 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
veth_xmit(struct sk_buff * skb,struct net_device * dev)343 static 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(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, 1, length);
377 else
378 __veth_xdp_flush(rq);
379 } else {
380 drop:
381 atomic64_inc(&priv->dropped);
382 ret = NET_XMIT_DROP;
383 }
384
385 rcu_read_unlock();
386
387 return ret;
388 }
389
veth_stats_rx(struct veth_stats * result,struct net_device * dev)390 static 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(&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(&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
veth_get_stats64(struct net_device * dev,struct rtnl_link_stats64 * tot)421 static 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(&priv->dropped);
429 dev_fetch_sw_netstats(tot, dev->tstats);
430
431 veth_stats_rx(&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(&tot_peer, peer->tstats);
443 tot->rx_bytes += tot_peer.tx_bytes;
444 tot->rx_packets += tot_peer.tx_packets;
445
446 veth_stats_rx(&rx, 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 */
veth_set_multicast_list(struct net_device * dev)456 static void veth_set_multicast_list(struct net_device *dev)
457 {
458 }
459
veth_select_rxq(struct net_device * dev)460 static int veth_select_rxq(struct net_device *dev)
461 {
462 return smp_processor_id() % dev->real_num_rx_queues;
463 }
464
veth_peer_dev(struct net_device * dev)465 static 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
veth_xdp_xmit(struct net_device * dev,int n,struct xdp_frame ** frames,u32 flags,bool ndo_xmit)473 static 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(rcv);
492 rq = &rcv_priv->rq[veth_select_rxq(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(&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(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(&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(&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(&rq->stats.syncp);
522 }
523
524 out:
525 rcu_read_unlock();
526
527 return ret;
528 }
529
veth_ndo_xdp_xmit(struct net_device * dev,int n,struct xdp_frame ** frames,u32 flags)530 static 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, true);
536 if (err < 0) {
537 struct veth_priv *priv = netdev_priv(dev);
538
539 atomic64_add(n, &priv->dropped);
540 }
541
542 return err;
543 }
544
veth_xdp_flush_bq(struct veth_rq * rq,struct veth_xdp_tx_bq * bq)545 static 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(rq->dev, bq->count, bq->q, 0, 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(bq->q[i]);
557
558 drops = bq->count - sent;
559 trace_xdp_bulk_tx(rq->dev, sent, drops, err);
560
561 u64_stats_update_begin(&rq->stats.syncp);
562 rq->stats.vs.xdp_tx += sent;
563 rq->stats.vs.xdp_tx_err += drops;
564 u64_stats_update_end(&rq->stats.syncp);
565
566 bq->count = 0;
567 }
568
veth_xdp_flush(struct veth_rq * rq,struct veth_xdp_tx_bq * bq)569 static void veth_xdp_flush(struct veth_rq *rq, struct veth_xdp_tx_bq *bq)
570 {
571 struct veth_priv *rcv_priv, *priv = netdev_priv(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(rcv);
582 rcv_rq = &rcv_priv->rq[veth_select_rxq(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(rcv_rq);
588 out:
589 rcu_read_unlock();
590 }
591
veth_xdp_tx(struct veth_rq * rq,struct xdp_buff * xdp,struct veth_xdp_tx_bq * bq)592 static 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
veth_xdp_rcv_one(struct veth_rq * rq,struct xdp_frame * frame,struct veth_xdp_tx_bq * bq,struct veth_stats * stats)608 static 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(xdp_prog, xdp);
628
629 switch (act) {
630 case XDP_PASS:
631 if (xdp_update_frame_from_buff(xdp, 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(rq->dev, 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(rq->dev, xdp, 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(rq->dev, xdp_prog, act);
659 fallthrough;
660 case XDP_ABORTED:
661 trace_xdp_exception(rq->dev, 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;
671 err_xdp:
672 rcu_read_unlock();
673 xdp_return_frame(frame);
674 xdp_xmit:
675 return NULL;
676 }
677
678 /* frames array contains VETH_XDP_BATCH at most */
veth_xdp_rcv_bulk_skb(struct veth_rq * rq,void ** frames,int n_xdpf,struct veth_xdp_tx_bq * bq,struct veth_stats * stats)679 static 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_xdpf,
687 GFP_ATOMIC | __GFP_ZERO) < 0) {
688 for (i = 0; i < n_xdpf; i++)
689 xdp_return_frame(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(frames[i], skb,
699 rq->dev);
700 if (!skb) {
701 xdp_return_frame(frames[i]);
702 stats->rx_drops++;
703 continue;
704 }
705 napi_gro_receive(&rq->xdp_napi, skb);
706 }
707 }
708
veth_xdp_get(struct xdp_buff * xdp)709 static 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(&sinfo->frags[i]);
720 }
721
veth_convert_skb_to_xdp_buff(struct veth_rq * rq,struct xdp_buff * xdp,struct sk_buff ** pskb)722 static 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 u32 size, len, max_head_size, off;
733 struct sk_buff *nskb;
734 struct page *page;
735 int i, head_off;
736
737 /* We need a private copy of the skb and data buffers since
738 * the ebpf program can modify it. We segment the original skb
739 * into order-0 pages without linearize it.
740 *
741 * Make sure we have enough space for linear and paged area
742 */
743 max_head_size = SKB_WITH_OVERHEAD(PAGE_SIZE -
744 VETH_XDP_HEADROOM);
745 if (skb->len > PAGE_SIZE * MAX_SKB_FRAGS + max_head_size)
746 goto drop;
747
748 /* Allocate skb head */
749 page = page_pool_dev_alloc_pages(rq->page_pool);
750 if (!page)
751 goto drop;
752
753 nskb = napi_build_skb(page_address(page), PAGE_SIZE);
754 if (!nskb) {
755 page_pool_put_full_page(rq->page_pool, page, true);
756 goto drop;
757 }
758
759 skb_reserve(nskb, VETH_XDP_HEADROOM);
760 skb_copy_header(nskb, skb);
761 skb_mark_for_recycle(nskb);
762
763 size = min_t(u32, skb->len, max_head_size);
764 if (skb_copy_bits(skb, 0, nskb->data, size)) {
765 consume_skb(nskb);
766 goto drop;
767 }
768 skb_put(nskb, size);
769
770 head_off = skb_headroom(nskb) - skb_headroom(skb);
771 skb_headers_offset_update(nskb, head_off);
772
773 /* Allocate paged area of new skb */
774 off = size;
775 len = skb->len - off;
776
777 for (i = 0; i < MAX_SKB_FRAGS && off < skb->len; i++) {
778 page = page_pool_dev_alloc_pages(rq->page_pool);
779 if (!page) {
780 consume_skb(nskb);
781 goto drop;
782 }
783
784 size = min_t(u32, len, PAGE_SIZE);
785 skb_add_rx_frag(nskb, i, page, 0, size, PAGE_SIZE);
786 if (skb_copy_bits(skb, off, page_address(page),
787 size)) {
788 consume_skb(nskb);
789 goto drop;
790 }
791
792 len -= size;
793 off += size;
794 }
795
796 consume_skb(skb);
797 skb = nskb;
798 }
799
800 /* SKB "head" area always have tailroom for skb_shared_info */
801 frame_sz = skb_end_pointer(skb) - skb->head;
802 frame_sz += SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
803 xdp_init_buff(xdp, frame_sz, &rq->xdp_rxq);
804 xdp_prepare_buff(xdp, skb->head, skb_headroom(skb),
805 skb_headlen(skb), true);
806
807 if (skb_is_nonlinear(skb)) {
808 skb_shinfo(skb)->xdp_frags_size = skb->data_len;
809 xdp_buff_set_frags_flag(xdp);
810 } else {
811 xdp_buff_clear_frags_flag(xdp);
812 }
813 *pskb = skb;
814
815 return 0;
816 drop:
817 consume_skb(skb);
818 *pskb = NULL;
819
820 return -ENOMEM;
821 }
822
veth_xdp_rcv_skb(struct veth_rq * rq,struct sk_buff * skb,struct veth_xdp_tx_bq * bq,struct veth_stats * stats)823 static struct sk_buff *veth_xdp_rcv_skb(struct veth_rq *rq,
824 struct sk_buff *skb,
825 struct veth_xdp_tx_bq *bq,
826 struct veth_stats *stats)
827 {
828 void *orig_data, *orig_data_end;
829 struct bpf_prog *xdp_prog;
830 struct veth_xdp_buff vxbuf;
831 struct xdp_buff *xdp = &vxbuf.xdp;
832 u32 act, metalen;
833 int off;
834
835 skb_prepare_for_gro(skb);
836
837 rcu_read_lock();
838 xdp_prog = rcu_dereference(rq->xdp_prog);
839 if (unlikely(!xdp_prog)) {
840 rcu_read_unlock();
841 goto out;
842 }
843
844 __skb_push(skb, skb->data - skb_mac_header(skb));
845 if (veth_convert_skb_to_xdp_buff(rq, xdp, &skb))
846 goto drop;
847 vxbuf.skb = skb;
848
849 orig_data = xdp->data;
850 orig_data_end = xdp->data_end;
851
852 act = bpf_prog_run_xdp(xdp_prog, xdp);
853
854 switch (act) {
855 case XDP_PASS:
856 break;
857 case XDP_TX:
858 veth_xdp_get(xdp);
859 consume_skb(skb);
860 xdp->rxq->mem = rq->xdp_mem;
861 if (unlikely(veth_xdp_tx(rq, xdp, bq) < 0)) {
862 trace_xdp_exception(rq->dev, xdp_prog, act);
863 stats->rx_drops++;
864 goto err_xdp;
865 }
866 stats->xdp_tx++;
867 rcu_read_unlock();
868 goto xdp_xmit;
869 case XDP_REDIRECT:
870 veth_xdp_get(xdp);
871 consume_skb(skb);
872 xdp->rxq->mem = rq->xdp_mem;
873 if (xdp_do_redirect(rq->dev, xdp, xdp_prog)) {
874 stats->rx_drops++;
875 goto err_xdp;
876 }
877 stats->xdp_redirect++;
878 rcu_read_unlock();
879 goto xdp_xmit;
880 default:
881 bpf_warn_invalid_xdp_action(rq->dev, xdp_prog, act);
882 fallthrough;
883 case XDP_ABORTED:
884 trace_xdp_exception(rq->dev, xdp_prog, act);
885 fallthrough;
886 case XDP_DROP:
887 stats->xdp_drops++;
888 goto xdp_drop;
889 }
890 rcu_read_unlock();
891
892 /* check if bpf_xdp_adjust_head was used */
893 off = orig_data - xdp->data;
894 if (off > 0)
895 __skb_push(skb, off);
896 else if (off < 0)
897 __skb_pull(skb, -off);
898
899 skb_reset_mac_header(skb);
900
901 /* check if bpf_xdp_adjust_tail was used */
902 off = xdp->data_end - orig_data_end;
903 if (off != 0)
904 __skb_put(skb, off); /* positive on grow, negative on shrink */
905
906 /* XDP frag metadata (e.g. nr_frags) are updated in eBPF helpers
907 * (e.g. bpf_xdp_adjust_tail), we need to update data_len here.
908 */
909 if (xdp_buff_has_frags(xdp))
910 skb->data_len = skb_shinfo(skb)->xdp_frags_size;
911 else
912 skb->data_len = 0;
913
914 skb->protocol = eth_type_trans(skb, rq->dev);
915
916 metalen = xdp->data - xdp->data_meta;
917 if (metalen)
918 skb_metadata_set(skb, metalen);
919 out:
920 return skb;
921 drop:
922 stats->rx_drops++;
923 xdp_drop:
924 rcu_read_unlock();
925 kfree_skb(skb);
926 return NULL;
927 err_xdp:
928 rcu_read_unlock();
929 xdp_return_buff(xdp);
930 xdp_xmit:
931 return NULL;
932 }
933
veth_xdp_rcv(struct veth_rq * rq,int budget,struct veth_xdp_tx_bq * bq,struct veth_stats * stats)934 static int veth_xdp_rcv(struct veth_rq *rq, int budget,
935 struct veth_xdp_tx_bq *bq,
936 struct veth_stats *stats)
937 {
938 int i, done = 0, n_xdpf = 0;
939 void *xdpf[VETH_XDP_BATCH];
940
941 for (i = 0; i < budget; i++) {
942 void *ptr = __ptr_ring_consume(&rq->xdp_ring);
943
944 if (!ptr)
945 break;
946
947 if (veth_is_xdp_frame(ptr)) {
948 /* ndo_xdp_xmit */
949 struct xdp_frame *frame = veth_ptr_to_xdp(ptr);
950
951 stats->xdp_bytes += xdp_get_frame_len(frame);
952 frame = veth_xdp_rcv_one(rq, frame, bq, stats);
953 if (frame) {
954 /* XDP_PASS */
955 xdpf[n_xdpf++] = frame;
956 if (n_xdpf == VETH_XDP_BATCH) {
957 veth_xdp_rcv_bulk_skb(rq, xdpf, n_xdpf,
958 bq, stats);
959 n_xdpf = 0;
960 }
961 }
962 } else {
963 /* ndo_start_xmit */
964 struct sk_buff *skb = ptr;
965
966 stats->xdp_bytes += skb->len;
967 skb = veth_xdp_rcv_skb(rq, skb, bq, stats);
968 if (skb) {
969 if (skb_shared(skb) || skb_unclone(skb, GFP_ATOMIC))
970 netif_receive_skb(skb);
971 else
972 napi_gro_receive(&rq->xdp_napi, skb);
973 }
974 }
975 done++;
976 }
977
978 if (n_xdpf)
979 veth_xdp_rcv_bulk_skb(rq, xdpf, n_xdpf, bq, stats);
980
981 u64_stats_update_begin(&rq->stats.syncp);
982 rq->stats.vs.xdp_redirect += stats->xdp_redirect;
983 rq->stats.vs.xdp_bytes += stats->xdp_bytes;
984 rq->stats.vs.xdp_drops += stats->xdp_drops;
985 rq->stats.vs.rx_drops += stats->rx_drops;
986 rq->stats.vs.xdp_packets += done;
987 u64_stats_update_end(&rq->stats.syncp);
988
989 return done;
990 }
991
veth_poll(struct napi_struct * napi,int budget)992 static int veth_poll(struct napi_struct *napi, int budget)
993 {
994 struct veth_rq *rq =
995 container_of(napi, struct veth_rq, xdp_napi);
996 struct veth_stats stats = {};
997 struct veth_xdp_tx_bq bq;
998 int done;
999
1000 bq.count = 0;
1001
1002 xdp_set_return_frame_no_direct();
1003 done = veth_xdp_rcv(rq, budget, &bq, &stats);
1004
1005 if (stats.xdp_redirect > 0)
1006 xdp_do_flush();
1007
1008 if (done < budget && napi_complete_done(napi, done)) {
1009 /* Write rx_notify_masked before reading ptr_ring */
1010 smp_store_mb(rq->rx_notify_masked, false);
1011 if (unlikely(!__ptr_ring_empty(&rq->xdp_ring))) {
1012 if (napi_schedule_prep(&rq->xdp_napi)) {
1013 WRITE_ONCE(rq->rx_notify_masked, true);
1014 __napi_schedule(&rq->xdp_napi);
1015 }
1016 }
1017 }
1018
1019 if (stats.xdp_tx > 0)
1020 veth_xdp_flush(rq, &bq);
1021 xdp_clear_return_frame_no_direct();
1022
1023 return done;
1024 }
1025
veth_create_page_pool(struct veth_rq * rq)1026 static int veth_create_page_pool(struct veth_rq *rq)
1027 {
1028 struct page_pool_params pp_params = {
1029 .order = 0,
1030 .pool_size = VETH_RING_SIZE,
1031 .nid = NUMA_NO_NODE,
1032 .dev = &rq->dev->dev,
1033 };
1034
1035 rq->page_pool = page_pool_create(&pp_params);
1036 if (IS_ERR(rq->page_pool)) {
1037 int err = PTR_ERR(rq->page_pool);
1038
1039 rq->page_pool = NULL;
1040 return err;
1041 }
1042
1043 return 0;
1044 }
1045
__veth_napi_enable_range(struct net_device * dev,int start,int end)1046 static int __veth_napi_enable_range(struct net_device *dev, int start, int end)
1047 {
1048 struct veth_priv *priv = netdev_priv(dev);
1049 int err, i;
1050
1051 for (i = start; i < end; i++) {
1052 err = veth_create_page_pool(&priv->rq[i]);
1053 if (err)
1054 goto err_page_pool;
1055 }
1056
1057 for (i = start; i < end; i++) {
1058 struct veth_rq *rq = &priv->rq[i];
1059
1060 err = ptr_ring_init(&rq->xdp_ring, VETH_RING_SIZE, GFP_KERNEL);
1061 if (err)
1062 goto err_xdp_ring;
1063 }
1064
1065 for (i = start; i < end; i++) {
1066 struct veth_rq *rq = &priv->rq[i];
1067
1068 napi_enable(&rq->xdp_napi);
1069 rcu_assign_pointer(priv->rq[i].napi, &priv->rq[i].xdp_napi);
1070 }
1071
1072 return 0;
1073
1074 err_xdp_ring:
1075 for (i--; i >= start; i--)
1076 ptr_ring_cleanup(&priv->rq[i].xdp_ring, veth_ptr_free);
1077 i = end;
1078 err_page_pool:
1079 for (i--; i >= start; i--) {
1080 page_pool_destroy(priv->rq[i].page_pool);
1081 priv->rq[i].page_pool = NULL;
1082 }
1083
1084 return err;
1085 }
1086
__veth_napi_enable(struct net_device * dev)1087 static int __veth_napi_enable(struct net_device *dev)
1088 {
1089 return __veth_napi_enable_range(dev, 0, dev->real_num_rx_queues);
1090 }
1091
veth_napi_del_range(struct net_device * dev,int start,int end)1092 static void veth_napi_del_range(struct net_device *dev, int start, int end)
1093 {
1094 struct veth_priv *priv = netdev_priv(dev);
1095 int i;
1096
1097 for (i = start; i < end; i++) {
1098 struct veth_rq *rq = &priv->rq[i];
1099
1100 rcu_assign_pointer(priv->rq[i].napi, NULL);
1101 napi_disable(&rq->xdp_napi);
1102 __netif_napi_del(&rq->xdp_napi);
1103 }
1104 synchronize_net();
1105
1106 for (i = start; i < end; i++) {
1107 struct veth_rq *rq = &priv->rq[i];
1108
1109 rq->rx_notify_masked = false;
1110 ptr_ring_cleanup(&rq->xdp_ring, veth_ptr_free);
1111 }
1112
1113 for (i = start; i < end; i++) {
1114 page_pool_destroy(priv->rq[i].page_pool);
1115 priv->rq[i].page_pool = NULL;
1116 }
1117 }
1118
veth_napi_del(struct net_device * dev)1119 static void veth_napi_del(struct net_device *dev)
1120 {
1121 veth_napi_del_range(dev, 0, dev->real_num_rx_queues);
1122 }
1123
veth_gro_requested(const struct net_device * dev)1124 static bool veth_gro_requested(const struct net_device *dev)
1125 {
1126 return !!(dev->wanted_features & NETIF_F_GRO);
1127 }
1128
veth_enable_xdp_range(struct net_device * dev,int start,int end,bool napi_already_on)1129 static int veth_enable_xdp_range(struct net_device *dev, int start, int end,
1130 bool napi_already_on)
1131 {
1132 struct veth_priv *priv = netdev_priv(dev);
1133 int err, i;
1134
1135 for (i = start; i < end; i++) {
1136 struct veth_rq *rq = &priv->rq[i];
1137
1138 if (!napi_already_on)
1139 netif_napi_add(dev, &rq->xdp_napi, veth_poll);
1140 err = xdp_rxq_info_reg(&rq->xdp_rxq, dev, i, rq->xdp_napi.napi_id);
1141 if (err < 0)
1142 goto err_rxq_reg;
1143
1144 err = xdp_rxq_info_reg_mem_model(&rq->xdp_rxq,
1145 MEM_TYPE_PAGE_SHARED,
1146 NULL);
1147 if (err < 0)
1148 goto err_reg_mem;
1149
1150 /* Save original mem info as it can be overwritten */
1151 rq->xdp_mem = rq->xdp_rxq.mem;
1152 }
1153 return 0;
1154
1155 err_reg_mem:
1156 xdp_rxq_info_unreg(&priv->rq[i].xdp_rxq);
1157 err_rxq_reg:
1158 for (i--; i >= start; i--) {
1159 struct veth_rq *rq = &priv->rq[i];
1160
1161 xdp_rxq_info_unreg(&rq->xdp_rxq);
1162 if (!napi_already_on)
1163 netif_napi_del(&rq->xdp_napi);
1164 }
1165
1166 return err;
1167 }
1168
veth_disable_xdp_range(struct net_device * dev,int start,int end,bool delete_napi)1169 static void veth_disable_xdp_range(struct net_device *dev, int start, int end,
1170 bool delete_napi)
1171 {
1172 struct veth_priv *priv = netdev_priv(dev);
1173 int i;
1174
1175 for (i = start; i < end; i++) {
1176 struct veth_rq *rq = &priv->rq[i];
1177
1178 rq->xdp_rxq.mem = rq->xdp_mem;
1179 xdp_rxq_info_unreg(&rq->xdp_rxq);
1180
1181 if (delete_napi)
1182 netif_napi_del(&rq->xdp_napi);
1183 }
1184 }
1185
veth_enable_xdp(struct net_device * dev)1186 static int veth_enable_xdp(struct net_device *dev)
1187 {
1188 bool napi_already_on = veth_gro_requested(dev) && (dev->flags & IFF_UP);
1189 struct veth_priv *priv = netdev_priv(dev);
1190 int err, i;
1191
1192 if (!xdp_rxq_info_is_reg(&priv->rq[0].xdp_rxq)) {
1193 err = veth_enable_xdp_range(dev, 0, dev->real_num_rx_queues, napi_already_on);
1194 if (err)
1195 return err;
1196
1197 if (!napi_already_on) {
1198 err = __veth_napi_enable(dev);
1199 if (err) {
1200 veth_disable_xdp_range(dev, 0, dev->real_num_rx_queues, true);
1201 return err;
1202 }
1203 }
1204 }
1205
1206 for (i = 0; i < dev->real_num_rx_queues; i++) {
1207 rcu_assign_pointer(priv->rq[i].xdp_prog, priv->_xdp_prog);
1208 rcu_assign_pointer(priv->rq[i].napi, &priv->rq[i].xdp_napi);
1209 }
1210
1211 return 0;
1212 }
1213
veth_disable_xdp(struct net_device * dev)1214 static void veth_disable_xdp(struct net_device *dev)
1215 {
1216 struct veth_priv *priv = netdev_priv(dev);
1217 int i;
1218
1219 for (i = 0; i < dev->real_num_rx_queues; i++)
1220 rcu_assign_pointer(priv->rq[i].xdp_prog, NULL);
1221
1222 if (!netif_running(dev) || !veth_gro_requested(dev))
1223 veth_napi_del(dev);
1224
1225 veth_disable_xdp_range(dev, 0, dev->real_num_rx_queues, false);
1226 }
1227
veth_napi_enable_range(struct net_device * dev,int start,int end)1228 static int veth_napi_enable_range(struct net_device *dev, int start, int end)
1229 {
1230 struct veth_priv *priv = netdev_priv(dev);
1231 int err, i;
1232
1233 for (i = start; i < end; i++) {
1234 struct veth_rq *rq = &priv->rq[i];
1235
1236 netif_napi_add(dev, &rq->xdp_napi, veth_poll);
1237 }
1238
1239 err = __veth_napi_enable_range(dev, start, end);
1240 if (err) {
1241 for (i = start; i < end; i++) {
1242 struct veth_rq *rq = &priv->rq[i];
1243
1244 netif_napi_del(&rq->xdp_napi);
1245 }
1246 return err;
1247 }
1248 return err;
1249 }
1250
veth_napi_enable(struct net_device * dev)1251 static int veth_napi_enable(struct net_device *dev)
1252 {
1253 return veth_napi_enable_range(dev, 0, dev->real_num_rx_queues);
1254 }
1255
veth_disable_range_safe(struct net_device * dev,int start,int end)1256 static void veth_disable_range_safe(struct net_device *dev, int start, int end)
1257 {
1258 struct veth_priv *priv = netdev_priv(dev);
1259
1260 if (start >= end)
1261 return;
1262
1263 if (priv->_xdp_prog) {
1264 veth_napi_del_range(dev, start, end);
1265 veth_disable_xdp_range(dev, start, end, false);
1266 } else if (veth_gro_requested(dev)) {
1267 veth_napi_del_range(dev, start, end);
1268 }
1269 }
1270
veth_enable_range_safe(struct net_device * dev,int start,int end)1271 static int veth_enable_range_safe(struct net_device *dev, int start, int end)
1272 {
1273 struct veth_priv *priv = netdev_priv(dev);
1274 int err;
1275
1276 if (start >= end)
1277 return 0;
1278
1279 if (priv->_xdp_prog) {
1280 /* these channels are freshly initialized, napi is not on there even
1281 * when GRO is requeste
1282 */
1283 err = veth_enable_xdp_range(dev, start, end, false);
1284 if (err)
1285 return err;
1286
1287 err = __veth_napi_enable_range(dev, start, end);
1288 if (err) {
1289 /* on error always delete the newly added napis */
1290 veth_disable_xdp_range(dev, start, end, true);
1291 return err;
1292 }
1293 } else if (veth_gro_requested(dev)) {
1294 return veth_napi_enable_range(dev, start, end);
1295 }
1296 return 0;
1297 }
1298
veth_set_xdp_features(struct net_device * dev)1299 static void veth_set_xdp_features(struct net_device *dev)
1300 {
1301 struct veth_priv *priv = netdev_priv(dev);
1302 struct net_device *peer;
1303
1304 peer = rtnl_dereference(priv->peer);
1305 if (peer && peer->real_num_tx_queues <= dev->real_num_rx_queues) {
1306 struct veth_priv *priv_peer = netdev_priv(peer);
1307 xdp_features_t val = NETDEV_XDP_ACT_BASIC |
1308 NETDEV_XDP_ACT_REDIRECT |
1309 NETDEV_XDP_ACT_RX_SG;
1310
1311 if (priv_peer->_xdp_prog || veth_gro_requested(peer))
1312 val |= NETDEV_XDP_ACT_NDO_XMIT |
1313 NETDEV_XDP_ACT_NDO_XMIT_SG;
1314 xdp_set_features_flag(dev, val);
1315 } else {
1316 xdp_clear_features_flag(dev);
1317 }
1318 }
1319
veth_set_channels(struct net_device * dev,struct ethtool_channels * ch)1320 static int veth_set_channels(struct net_device *dev,
1321 struct ethtool_channels *ch)
1322 {
1323 struct veth_priv *priv = netdev_priv(dev);
1324 unsigned int old_rx_count, new_rx_count;
1325 struct veth_priv *peer_priv;
1326 struct net_device *peer;
1327 int err;
1328
1329 /* sanity check. Upper bounds are already enforced by the caller */
1330 if (!ch->rx_count || !ch->tx_count)
1331 return -EINVAL;
1332
1333 /* avoid braking XDP, if that is enabled */
1334 peer = rtnl_dereference(priv->peer);
1335 peer_priv = peer ? netdev_priv(peer) : NULL;
1336 if (priv->_xdp_prog && peer && ch->rx_count < peer->real_num_tx_queues)
1337 return -EINVAL;
1338
1339 if (peer && peer_priv && peer_priv->_xdp_prog && ch->tx_count > peer->real_num_rx_queues)
1340 return -EINVAL;
1341
1342 old_rx_count = dev->real_num_rx_queues;
1343 new_rx_count = ch->rx_count;
1344 if (netif_running(dev)) {
1345 /* turn device off */
1346 netif_carrier_off(dev);
1347 if (peer)
1348 netif_carrier_off(peer);
1349
1350 /* try to allocate new resurces, as needed*/
1351 err = veth_enable_range_safe(dev, old_rx_count, new_rx_count);
1352 if (err)
1353 goto out;
1354 }
1355
1356 err = netif_set_real_num_rx_queues(dev, ch->rx_count);
1357 if (err)
1358 goto revert;
1359
1360 err = netif_set_real_num_tx_queues(dev, ch->tx_count);
1361 if (err) {
1362 int err2 = netif_set_real_num_rx_queues(dev, old_rx_count);
1363
1364 /* this error condition could happen only if rx and tx change
1365 * in opposite directions (e.g. tx nr raises, rx nr decreases)
1366 * and we can't do anything to fully restore the original
1367 * status
1368 */
1369 if (err2)
1370 pr_warn("Can't restore rx queues config %d -> %d %d",
1371 new_rx_count, old_rx_count, err2);
1372 else
1373 goto revert;
1374 }
1375
1376 out:
1377 if (netif_running(dev)) {
1378 /* note that we need to swap the arguments WRT the enable part
1379 * to identify the range we have to disable
1380 */
1381 veth_disable_range_safe(dev, new_rx_count, old_rx_count);
1382 netif_carrier_on(dev);
1383 if (peer)
1384 netif_carrier_on(peer);
1385 }
1386
1387 /* update XDP supported features */
1388 veth_set_xdp_features(dev);
1389 if (peer)
1390 veth_set_xdp_features(peer);
1391
1392 return err;
1393
1394 revert:
1395 new_rx_count = old_rx_count;
1396 old_rx_count = ch->rx_count;
1397 goto out;
1398 }
1399
veth_open(struct net_device * dev)1400 static int veth_open(struct net_device *dev)
1401 {
1402 struct veth_priv *priv = netdev_priv(dev);
1403 struct net_device *peer = rtnl_dereference(priv->peer);
1404 int err;
1405
1406 if (!peer)
1407 return -ENOTCONN;
1408
1409 if (priv->_xdp_prog) {
1410 err = veth_enable_xdp(dev);
1411 if (err)
1412 return err;
1413 } else if (veth_gro_requested(dev)) {
1414 err = veth_napi_enable(dev);
1415 if (err)
1416 return err;
1417 }
1418
1419 if (peer->flags & IFF_UP) {
1420 netif_carrier_on(dev);
1421 netif_carrier_on(peer);
1422 }
1423
1424 veth_set_xdp_features(dev);
1425
1426 return 0;
1427 }
1428
veth_close(struct net_device * dev)1429 static int veth_close(struct net_device *dev)
1430 {
1431 struct veth_priv *priv = netdev_priv(dev);
1432 struct net_device *peer = rtnl_dereference(priv->peer);
1433
1434 netif_carrier_off(dev);
1435 if (peer)
1436 netif_carrier_off(peer);
1437
1438 if (priv->_xdp_prog)
1439 veth_disable_xdp(dev);
1440 else if (veth_gro_requested(dev))
1441 veth_napi_del(dev);
1442
1443 return 0;
1444 }
1445
is_valid_veth_mtu(int mtu)1446 static int is_valid_veth_mtu(int mtu)
1447 {
1448 return mtu >= ETH_MIN_MTU && mtu <= ETH_MAX_MTU;
1449 }
1450
veth_alloc_queues(struct net_device * dev)1451 static int veth_alloc_queues(struct net_device *dev)
1452 {
1453 struct veth_priv *priv = netdev_priv(dev);
1454 int i;
1455
1456 priv->rq = kvcalloc(dev->num_rx_queues, sizeof(*priv->rq),
1457 GFP_KERNEL_ACCOUNT | __GFP_RETRY_MAYFAIL);
1458 if (!priv->rq)
1459 return -ENOMEM;
1460
1461 for (i = 0; i < dev->num_rx_queues; i++) {
1462 priv->rq[i].dev = dev;
1463 u64_stats_init(&priv->rq[i].stats.syncp);
1464 }
1465
1466 return 0;
1467 }
1468
veth_free_queues(struct net_device * dev)1469 static void veth_free_queues(struct net_device *dev)
1470 {
1471 struct veth_priv *priv = netdev_priv(dev);
1472
1473 kvfree(priv->rq);
1474 }
1475
veth_dev_init(struct net_device * dev)1476 static int veth_dev_init(struct net_device *dev)
1477 {
1478 netdev_lockdep_set_classes(dev);
1479 return veth_alloc_queues(dev);
1480 }
1481
veth_dev_free(struct net_device * dev)1482 static void veth_dev_free(struct net_device *dev)
1483 {
1484 veth_free_queues(dev);
1485 }
1486
1487 #ifdef CONFIG_NET_POLL_CONTROLLER
veth_poll_controller(struct net_device * dev)1488 static void veth_poll_controller(struct net_device *dev)
1489 {
1490 /* veth only receives frames when its peer sends one
1491 * Since it has nothing to do with disabling irqs, we are guaranteed
1492 * never to have pending data when we poll for it so
1493 * there is nothing to do here.
1494 *
1495 * We need this though so netpoll recognizes us as an interface that
1496 * supports polling, which enables bridge devices in virt setups to
1497 * still use netconsole
1498 */
1499 }
1500 #endif /* CONFIG_NET_POLL_CONTROLLER */
1501
veth_get_iflink(const struct net_device * dev)1502 static int veth_get_iflink(const struct net_device *dev)
1503 {
1504 struct veth_priv *priv = netdev_priv(dev);
1505 struct net_device *peer;
1506 int iflink;
1507
1508 rcu_read_lock();
1509 peer = rcu_dereference(priv->peer);
1510 iflink = peer ? peer->ifindex : 0;
1511 rcu_read_unlock();
1512
1513 return iflink;
1514 }
1515
veth_fix_features(struct net_device * dev,netdev_features_t features)1516 static netdev_features_t veth_fix_features(struct net_device *dev,
1517 netdev_features_t features)
1518 {
1519 struct veth_priv *priv = netdev_priv(dev);
1520 struct net_device *peer;
1521
1522 peer = rtnl_dereference(priv->peer);
1523 if (peer) {
1524 struct veth_priv *peer_priv = netdev_priv(peer);
1525
1526 if (peer_priv->_xdp_prog)
1527 features &= ~NETIF_F_GSO_SOFTWARE;
1528 }
1529
1530 return features;
1531 }
1532
veth_set_features(struct net_device * dev,netdev_features_t features)1533 static int veth_set_features(struct net_device *dev,
1534 netdev_features_t features)
1535 {
1536 netdev_features_t changed = features ^ dev->features;
1537 struct veth_priv *priv = netdev_priv(dev);
1538 struct net_device *peer;
1539 int err;
1540
1541 if (!(changed & NETIF_F_GRO) || !(dev->flags & IFF_UP) || priv->_xdp_prog)
1542 return 0;
1543
1544 peer = rtnl_dereference(priv->peer);
1545 if (features & NETIF_F_GRO) {
1546 err = veth_napi_enable(dev);
1547 if (err)
1548 return err;
1549
1550 if (peer)
1551 xdp_features_set_redirect_target(peer, true);
1552 } else {
1553 if (peer)
1554 xdp_features_clear_redirect_target(peer);
1555 veth_napi_del(dev);
1556 }
1557 return 0;
1558 }
1559
veth_set_rx_headroom(struct net_device * dev,int new_hr)1560 static void veth_set_rx_headroom(struct net_device *dev, int new_hr)
1561 {
1562 struct veth_priv *peer_priv, *priv = netdev_priv(dev);
1563 struct net_device *peer;
1564
1565 if (new_hr < 0)
1566 new_hr = 0;
1567
1568 rcu_read_lock();
1569 peer = rcu_dereference(priv->peer);
1570 if (unlikely(!peer))
1571 goto out;
1572
1573 peer_priv = netdev_priv(peer);
1574 priv->requested_headroom = new_hr;
1575 new_hr = max(priv->requested_headroom, peer_priv->requested_headroom);
1576 dev->needed_headroom = new_hr;
1577 peer->needed_headroom = new_hr;
1578
1579 out:
1580 rcu_read_unlock();
1581 }
1582
veth_xdp_set(struct net_device * dev,struct bpf_prog * prog,struct netlink_ext_ack * extack)1583 static int veth_xdp_set(struct net_device *dev, struct bpf_prog *prog,
1584 struct netlink_ext_ack *extack)
1585 {
1586 struct veth_priv *priv = netdev_priv(dev);
1587 struct bpf_prog *old_prog;
1588 struct net_device *peer;
1589 unsigned int max_mtu;
1590 int err;
1591
1592 old_prog = priv->_xdp_prog;
1593 priv->_xdp_prog = prog;
1594 peer = rtnl_dereference(priv->peer);
1595
1596 if (prog) {
1597 if (!peer) {
1598 NL_SET_ERR_MSG_MOD(extack, "Cannot set XDP when peer is detached");
1599 err = -ENOTCONN;
1600 goto err;
1601 }
1602
1603 max_mtu = SKB_WITH_OVERHEAD(PAGE_SIZE - VETH_XDP_HEADROOM) -
1604 peer->hard_header_len;
1605 /* Allow increasing the max_mtu if the program supports
1606 * XDP fragments.
1607 */
1608 if (prog->aux->xdp_has_frags)
1609 max_mtu += PAGE_SIZE * MAX_SKB_FRAGS;
1610
1611 if (peer->mtu > max_mtu) {
1612 NL_SET_ERR_MSG_MOD(extack, "Peer MTU is too large to set XDP");
1613 err = -ERANGE;
1614 goto err;
1615 }
1616
1617 if (dev->real_num_rx_queues < peer->real_num_tx_queues) {
1618 NL_SET_ERR_MSG_MOD(extack, "XDP expects number of rx queues not less than peer tx queues");
1619 err = -ENOSPC;
1620 goto err;
1621 }
1622
1623 if (dev->flags & IFF_UP) {
1624 err = veth_enable_xdp(dev);
1625 if (err) {
1626 NL_SET_ERR_MSG_MOD(extack, "Setup for XDP failed");
1627 goto err;
1628 }
1629 }
1630
1631 if (!old_prog) {
1632 peer->hw_features &= ~NETIF_F_GSO_SOFTWARE;
1633 peer->max_mtu = max_mtu;
1634 }
1635
1636 xdp_features_set_redirect_target(peer, true);
1637 }
1638
1639 if (old_prog) {
1640 if (!prog) {
1641 if (peer && !veth_gro_requested(dev))
1642 xdp_features_clear_redirect_target(peer);
1643
1644 if (dev->flags & IFF_UP)
1645 veth_disable_xdp(dev);
1646
1647 if (peer) {
1648 peer->hw_features |= NETIF_F_GSO_SOFTWARE;
1649 peer->max_mtu = ETH_MAX_MTU;
1650 }
1651 }
1652 bpf_prog_put(old_prog);
1653 }
1654
1655 if ((!!old_prog ^ !!prog) && peer)
1656 netdev_update_features(peer);
1657
1658 return 0;
1659 err:
1660 priv->_xdp_prog = old_prog;
1661
1662 return err;
1663 }
1664
veth_xdp(struct net_device * dev,struct netdev_bpf * xdp)1665 static int veth_xdp(struct net_device *dev, struct netdev_bpf *xdp)
1666 {
1667 switch (xdp->command) {
1668 case XDP_SETUP_PROG:
1669 return veth_xdp_set(dev, xdp->prog, xdp->extack);
1670 default:
1671 return -EINVAL;
1672 }
1673 }
1674
veth_xdp_rx_timestamp(const struct xdp_md * ctx,u64 * timestamp)1675 static int veth_xdp_rx_timestamp(const struct xdp_md *ctx, u64 *timestamp)
1676 {
1677 struct veth_xdp_buff *_ctx = (void *)ctx;
1678
1679 if (!_ctx->skb)
1680 return -ENODATA;
1681
1682 *timestamp = skb_hwtstamps(_ctx->skb)->hwtstamp;
1683 return 0;
1684 }
1685
veth_xdp_rx_hash(const struct xdp_md * ctx,u32 * hash,enum xdp_rss_hash_type * rss_type)1686 static int veth_xdp_rx_hash(const struct xdp_md *ctx, u32 *hash,
1687 enum xdp_rss_hash_type *rss_type)
1688 {
1689 struct veth_xdp_buff *_ctx = (void *)ctx;
1690 struct sk_buff *skb = _ctx->skb;
1691
1692 if (!skb)
1693 return -ENODATA;
1694
1695 *hash = skb_get_hash(skb);
1696 *rss_type = skb->l4_hash ? XDP_RSS_TYPE_L4_ANY : XDP_RSS_TYPE_NONE;
1697
1698 return 0;
1699 }
1700
1701 static const struct net_device_ops veth_netdev_ops = {
1702 .ndo_init = veth_dev_init,
1703 .ndo_open = veth_open,
1704 .ndo_stop = veth_close,
1705 .ndo_start_xmit = veth_xmit,
1706 .ndo_get_stats64 = veth_get_stats64,
1707 .ndo_set_rx_mode = veth_set_multicast_list,
1708 .ndo_set_mac_address = eth_mac_addr,
1709 #ifdef CONFIG_NET_POLL_CONTROLLER
1710 .ndo_poll_controller = veth_poll_controller,
1711 #endif
1712 .ndo_get_iflink = veth_get_iflink,
1713 .ndo_fix_features = veth_fix_features,
1714 .ndo_set_features = veth_set_features,
1715 .ndo_features_check = passthru_features_check,
1716 .ndo_set_rx_headroom = veth_set_rx_headroom,
1717 .ndo_bpf = veth_xdp,
1718 .ndo_xdp_xmit = veth_ndo_xdp_xmit,
1719 .ndo_get_peer_dev = veth_peer_dev,
1720 };
1721
1722 static const struct xdp_metadata_ops veth_xdp_metadata_ops = {
1723 .xmo_rx_timestamp = veth_xdp_rx_timestamp,
1724 .xmo_rx_hash = veth_xdp_rx_hash,
1725 };
1726
1727 #define VETH_FEATURES (NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HW_CSUM | \
1728 NETIF_F_RXCSUM | NETIF_F_SCTP_CRC | NETIF_F_HIGHDMA | \
1729 NETIF_F_GSO_SOFTWARE | NETIF_F_GSO_ENCAP_ALL | \
1730 NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_CTAG_RX | \
1731 NETIF_F_HW_VLAN_STAG_TX | NETIF_F_HW_VLAN_STAG_RX )
1732
veth_setup(struct net_device * dev)1733 static void veth_setup(struct net_device *dev)
1734 {
1735 ether_setup(dev);
1736
1737 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1738 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1739 dev->priv_flags |= IFF_NO_QUEUE;
1740 dev->priv_flags |= IFF_PHONY_HEADROOM;
1741
1742 dev->netdev_ops = &veth_netdev_ops;
1743 dev->xdp_metadata_ops = &veth_xdp_metadata_ops;
1744 dev->ethtool_ops = &veth_ethtool_ops;
1745 dev->features |= NETIF_F_LLTX;
1746 dev->features |= VETH_FEATURES;
1747 dev->vlan_features = dev->features &
1748 ~(NETIF_F_HW_VLAN_CTAG_TX |
1749 NETIF_F_HW_VLAN_STAG_TX |
1750 NETIF_F_HW_VLAN_CTAG_RX |
1751 NETIF_F_HW_VLAN_STAG_RX);
1752 dev->needs_free_netdev = true;
1753 dev->priv_destructor = veth_dev_free;
1754 dev->pcpu_stat_type = NETDEV_PCPU_STAT_TSTATS;
1755 dev->max_mtu = ETH_MAX_MTU;
1756
1757 dev->hw_features = VETH_FEATURES;
1758 dev->hw_enc_features = VETH_FEATURES;
1759 dev->mpls_features = NETIF_F_HW_CSUM | NETIF_F_GSO_SOFTWARE;
1760 netif_set_tso_max_size(dev, GSO_MAX_SIZE);
1761 }
1762
1763 /*
1764 * netlink interface
1765 */
1766
veth_validate(struct nlattr * tb[],struct nlattr * data[],struct netlink_ext_ack * extack)1767 static int veth_validate(struct nlattr *tb[], struct nlattr *data[],
1768 struct netlink_ext_ack *extack)
1769 {
1770 if (tb[IFLA_ADDRESS]) {
1771 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1772 return -EINVAL;
1773 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1774 return -EADDRNOTAVAIL;
1775 }
1776 if (tb[IFLA_MTU]) {
1777 if (!is_valid_veth_mtu(nla_get_u32(tb[IFLA_MTU])))
1778 return -EINVAL;
1779 }
1780 return 0;
1781 }
1782
1783 static struct rtnl_link_ops veth_link_ops;
1784
veth_disable_gro(struct net_device * dev)1785 static void veth_disable_gro(struct net_device *dev)
1786 {
1787 dev->features &= ~NETIF_F_GRO;
1788 dev->wanted_features &= ~NETIF_F_GRO;
1789 netdev_update_features(dev);
1790 }
1791
veth_init_queues(struct net_device * dev,struct nlattr * tb[])1792 static int veth_init_queues(struct net_device *dev, struct nlattr *tb[])
1793 {
1794 int err;
1795
1796 if (!tb[IFLA_NUM_TX_QUEUES] && dev->num_tx_queues > 1) {
1797 err = netif_set_real_num_tx_queues(dev, 1);
1798 if (err)
1799 return err;
1800 }
1801 if (!tb[IFLA_NUM_RX_QUEUES] && dev->num_rx_queues > 1) {
1802 err = netif_set_real_num_rx_queues(dev, 1);
1803 if (err)
1804 return err;
1805 }
1806 return 0;
1807 }
1808
veth_newlink(struct net * src_net,struct net_device * dev,struct nlattr * tb[],struct nlattr * data[],struct netlink_ext_ack * extack)1809 static int veth_newlink(struct net *src_net, struct net_device *dev,
1810 struct nlattr *tb[], struct nlattr *data[],
1811 struct netlink_ext_ack *extack)
1812 {
1813 int err;
1814 struct net_device *peer;
1815 struct veth_priv *priv;
1816 char ifname[IFNAMSIZ];
1817 struct nlattr *peer_tb[IFLA_MAX + 1], **tbp;
1818 unsigned char name_assign_type;
1819 struct ifinfomsg *ifmp;
1820 struct net *net;
1821
1822 /*
1823 * create and register peer first
1824 */
1825 if (data != NULL && data[VETH_INFO_PEER] != NULL) {
1826 struct nlattr *nla_peer;
1827
1828 nla_peer = data[VETH_INFO_PEER];
1829 ifmp = nla_data(nla_peer);
1830 err = rtnl_nla_parse_ifinfomsg(peer_tb, nla_peer, extack);
1831 if (err < 0)
1832 return err;
1833
1834 err = veth_validate(peer_tb, NULL, extack);
1835 if (err < 0)
1836 return err;
1837
1838 tbp = peer_tb;
1839 } else {
1840 ifmp = NULL;
1841 tbp = tb;
1842 }
1843
1844 if (ifmp && tbp[IFLA_IFNAME]) {
1845 nla_strscpy(ifname, tbp[IFLA_IFNAME], IFNAMSIZ);
1846 name_assign_type = NET_NAME_USER;
1847 } else {
1848 snprintf(ifname, IFNAMSIZ, DRV_NAME "%%d");
1849 name_assign_type = NET_NAME_ENUM;
1850 }
1851
1852 net = rtnl_link_get_net(src_net, tbp);
1853 if (IS_ERR(net))
1854 return PTR_ERR(net);
1855
1856 peer = rtnl_create_link(net, ifname, name_assign_type,
1857 &veth_link_ops, tbp, extack);
1858 if (IS_ERR(peer)) {
1859 put_net(net);
1860 return PTR_ERR(peer);
1861 }
1862
1863 if (!ifmp || !tbp[IFLA_ADDRESS])
1864 eth_hw_addr_random(peer);
1865
1866 if (ifmp && (dev->ifindex != 0))
1867 peer->ifindex = ifmp->ifi_index;
1868
1869 netif_inherit_tso_max(peer, dev);
1870
1871 err = register_netdevice(peer);
1872 put_net(net);
1873 net = NULL;
1874 if (err < 0)
1875 goto err_register_peer;
1876
1877 /* keep GRO disabled by default to be consistent with the established
1878 * veth behavior
1879 */
1880 veth_disable_gro(peer);
1881 netif_carrier_off(peer);
1882
1883 err = rtnl_configure_link(peer, ifmp, 0, NULL);
1884 if (err < 0)
1885 goto err_configure_peer;
1886
1887 /*
1888 * register dev last
1889 *
1890 * note, that since we've registered new device the dev's name
1891 * should be re-allocated
1892 */
1893
1894 if (tb[IFLA_ADDRESS] == NULL)
1895 eth_hw_addr_random(dev);
1896
1897 if (tb[IFLA_IFNAME])
1898 nla_strscpy(dev->name, tb[IFLA_IFNAME], IFNAMSIZ);
1899 else
1900 snprintf(dev->name, IFNAMSIZ, DRV_NAME "%%d");
1901
1902 err = register_netdevice(dev);
1903 if (err < 0)
1904 goto err_register_dev;
1905
1906 netif_carrier_off(dev);
1907
1908 /*
1909 * tie the deviced together
1910 */
1911
1912 priv = netdev_priv(dev);
1913 rcu_assign_pointer(priv->peer, peer);
1914 err = veth_init_queues(dev, tb);
1915 if (err)
1916 goto err_queues;
1917
1918 priv = netdev_priv(peer);
1919 rcu_assign_pointer(priv->peer, dev);
1920 err = veth_init_queues(peer, tb);
1921 if (err)
1922 goto err_queues;
1923
1924 veth_disable_gro(dev);
1925 /* update XDP supported features */
1926 veth_set_xdp_features(dev);
1927 veth_set_xdp_features(peer);
1928
1929 return 0;
1930
1931 err_queues:
1932 unregister_netdevice(dev);
1933 err_register_dev:
1934 /* nothing to do */
1935 err_configure_peer:
1936 unregister_netdevice(peer);
1937 return err;
1938
1939 err_register_peer:
1940 free_netdev(peer);
1941 return err;
1942 }
1943
veth_dellink(struct net_device * dev,struct list_head * head)1944 static void veth_dellink(struct net_device *dev, struct list_head *head)
1945 {
1946 struct veth_priv *priv;
1947 struct net_device *peer;
1948
1949 priv = netdev_priv(dev);
1950 peer = rtnl_dereference(priv->peer);
1951
1952 /* Note : dellink() is called from default_device_exit_batch(),
1953 * before a rcu_synchronize() point. The devices are guaranteed
1954 * not being freed before one RCU grace period.
1955 */
1956 RCU_INIT_POINTER(priv->peer, NULL);
1957 unregister_netdevice_queue(dev, head);
1958
1959 if (peer) {
1960 priv = netdev_priv(peer);
1961 RCU_INIT_POINTER(priv->peer, NULL);
1962 unregister_netdevice_queue(peer, head);
1963 }
1964 }
1965
1966 static const struct nla_policy veth_policy[VETH_INFO_MAX + 1] = {
1967 [VETH_INFO_PEER] = { .len = sizeof(struct ifinfomsg) },
1968 };
1969
veth_get_link_net(const struct net_device * dev)1970 static struct net *veth_get_link_net(const struct net_device *dev)
1971 {
1972 struct veth_priv *priv = netdev_priv(dev);
1973 struct net_device *peer = rtnl_dereference(priv->peer);
1974
1975 return peer ? dev_net(peer) : dev_net(dev);
1976 }
1977
veth_get_num_queues(void)1978 static unsigned int veth_get_num_queues(void)
1979 {
1980 /* enforce the same queue limit as rtnl_create_link */
1981 int queues = num_possible_cpus();
1982
1983 if (queues > 4096)
1984 queues = 4096;
1985 return queues;
1986 }
1987
1988 static struct rtnl_link_ops veth_link_ops = {
1989 .kind = DRV_NAME,
1990 .priv_size = sizeof(struct veth_priv),
1991 .setup = veth_setup,
1992 .validate = veth_validate,
1993 .newlink = veth_newlink,
1994 .dellink = veth_dellink,
1995 .policy = veth_policy,
1996 .maxtype = VETH_INFO_MAX,
1997 .get_link_net = veth_get_link_net,
1998 .get_num_tx_queues = veth_get_num_queues,
1999 .get_num_rx_queues = veth_get_num_queues,
2000 };
2001
2002 /*
2003 * init/fini
2004 */
2005
veth_init(void)2006 static __init int veth_init(void)
2007 {
2008 return rtnl_link_register(&veth_link_ops);
2009 }
2010
veth_exit(void)2011 static __exit void veth_exit(void)
2012 {
2013 rtnl_link_unregister(&veth_link_ops);
2014 }
2015
2016 module_init(veth_init);
2017 module_exit(veth_exit);
2018
2019 MODULE_DESCRIPTION("Virtual Ethernet Tunnel");
2020 MODULE_LICENSE("GPL v2");
2021 MODULE_ALIAS_RTNL_LINK(DRV_NAME);
2022