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Merge tag 'timers-core-2020-08-14' of git://git.kernel.org/pub/scm/linux/kernel/git...
[mirror_ubuntu-jammy-kernel.git] / drivers / net / veth.c
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * drivers/net/veth.c
4 *
5 * Copyright (C) 2007 OpenVZ http://openvz.org, SWsoft Inc
6 *
7 * Author: Pavel Emelianov <xemul@openvz.org>
8 * Ethtool interface from: Eric W. Biederman <ebiederm@xmission.com>
9 *
10 */
11
12 #include <linux/netdevice.h>
13 #include <linux/slab.h>
14 #include <linux/ethtool.h>
15 #include <linux/etherdevice.h>
16 #include <linux/u64_stats_sync.h>
17
18 #include <net/rtnetlink.h>
19 #include <net/dst.h>
20 #include <net/xfrm.h>
21 #include <net/xdp.h>
22 #include <linux/veth.h>
23 #include <linux/module.h>
24 #include <linux/bpf.h>
25 #include <linux/filter.h>
26 #include <linux/ptr_ring.h>
27 #include <linux/bpf_trace.h>
28 #include <linux/net_tstamp.h>
29
30 #define DRV_NAME "veth"
31 #define DRV_VERSION "1.0"
32
33 #define VETH_XDP_FLAG BIT(0)
34 #define VETH_RING_SIZE 256
35 #define VETH_XDP_HEADROOM (XDP_PACKET_HEADROOM + NET_IP_ALIGN)
36
37 #define VETH_XDP_TX_BULK_SIZE 16
38
39 struct veth_stats {
40 u64 rx_drops;
41 /* xdp */
42 u64 xdp_packets;
43 u64 xdp_bytes;
44 u64 xdp_redirect;
45 u64 xdp_drops;
46 u64 xdp_tx;
47 u64 xdp_tx_err;
48 u64 peer_tq_xdp_xmit;
49 u64 peer_tq_xdp_xmit_err;
50 };
51
52 struct veth_rq_stats {
53 struct veth_stats vs;
54 struct u64_stats_sync syncp;
55 };
56
57 struct veth_rq {
58 struct napi_struct xdp_napi;
59 struct net_device *dev;
60 struct bpf_prog __rcu *xdp_prog;
61 struct xdp_mem_info xdp_mem;
62 struct veth_rq_stats stats;
63 bool rx_notify_masked;
64 struct ptr_ring xdp_ring;
65 struct xdp_rxq_info xdp_rxq;
66 };
67
68 struct veth_priv {
69 struct net_device __rcu *peer;
70 atomic64_t dropped;
71 struct bpf_prog *_xdp_prog;
72 struct veth_rq *rq;
73 unsigned int requested_headroom;
74 };
75
76 struct veth_xdp_tx_bq {
77 struct xdp_frame *q[VETH_XDP_TX_BULK_SIZE];
78 unsigned int count;
79 };
80
81 /*
82 * ethtool interface
83 */
84
85 struct veth_q_stat_desc {
86 char desc[ETH_GSTRING_LEN];
87 size_t offset;
88 };
89
90 #define VETH_RQ_STAT(m) offsetof(struct veth_stats, m)
91
92 static const struct veth_q_stat_desc veth_rq_stats_desc[] = {
93 { "xdp_packets", VETH_RQ_STAT(xdp_packets) },
94 { "xdp_bytes", VETH_RQ_STAT(xdp_bytes) },
95 { "drops", VETH_RQ_STAT(rx_drops) },
96 { "xdp_redirect", VETH_RQ_STAT(xdp_redirect) },
97 { "xdp_drops", VETH_RQ_STAT(xdp_drops) },
98 { "xdp_tx", VETH_RQ_STAT(xdp_tx) },
99 { "xdp_tx_errors", VETH_RQ_STAT(xdp_tx_err) },
100 };
101
102 #define VETH_RQ_STATS_LEN ARRAY_SIZE(veth_rq_stats_desc)
103
104 static const struct veth_q_stat_desc veth_tq_stats_desc[] = {
105 { "xdp_xmit", VETH_RQ_STAT(peer_tq_xdp_xmit) },
106 { "xdp_xmit_errors", VETH_RQ_STAT(peer_tq_xdp_xmit_err) },
107 };
108
109 #define VETH_TQ_STATS_LEN ARRAY_SIZE(veth_tq_stats_desc)
110
111 static struct {
112 const char string[ETH_GSTRING_LEN];
113 } ethtool_stats_keys[] = {
114 { "peer_ifindex" },
115 };
116
117 static int veth_get_link_ksettings(struct net_device *dev,
118 struct ethtool_link_ksettings *cmd)
119 {
120 cmd->base.speed = SPEED_10000;
121 cmd->base.duplex = DUPLEX_FULL;
122 cmd->base.port = PORT_TP;
123 cmd->base.autoneg = AUTONEG_DISABLE;
124 return 0;
125 }
126
127 static void veth_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
128 {
129 strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
130 strlcpy(info->version, DRV_VERSION, sizeof(info->version));
131 }
132
133 static void veth_get_strings(struct net_device *dev, u32 stringset, u8 *buf)
134 {
135 char *p = (char *)buf;
136 int i, j;
137
138 switch(stringset) {
139 case ETH_SS_STATS:
140 memcpy(p, &ethtool_stats_keys, sizeof(ethtool_stats_keys));
141 p += sizeof(ethtool_stats_keys);
142 for (i = 0; i < dev->real_num_rx_queues; i++) {
143 for (j = 0; j < VETH_RQ_STATS_LEN; j++) {
144 snprintf(p, ETH_GSTRING_LEN,
145 "rx_queue_%u_%.18s",
146 i, veth_rq_stats_desc[j].desc);
147 p += ETH_GSTRING_LEN;
148 }
149 }
150 for (i = 0; i < dev->real_num_tx_queues; i++) {
151 for (j = 0; j < VETH_TQ_STATS_LEN; j++) {
152 snprintf(p, ETH_GSTRING_LEN,
153 "tx_queue_%u_%.18s",
154 i, veth_tq_stats_desc[j].desc);
155 p += ETH_GSTRING_LEN;
156 }
157 }
158 break;
159 }
160 }
161
162 static int veth_get_sset_count(struct net_device *dev, int sset)
163 {
164 switch (sset) {
165 case ETH_SS_STATS:
166 return ARRAY_SIZE(ethtool_stats_keys) +
167 VETH_RQ_STATS_LEN * dev->real_num_rx_queues +
168 VETH_TQ_STATS_LEN * dev->real_num_tx_queues;
169 default:
170 return -EOPNOTSUPP;
171 }
172 }
173
174 static void veth_get_ethtool_stats(struct net_device *dev,
175 struct ethtool_stats *stats, u64 *data)
176 {
177 struct veth_priv *rcv_priv, *priv = netdev_priv(dev);
178 struct net_device *peer = rtnl_dereference(priv->peer);
179 int i, j, idx;
180
181 data[0] = peer ? peer->ifindex : 0;
182 idx = 1;
183 for (i = 0; i < dev->real_num_rx_queues; i++) {
184 const struct veth_rq_stats *rq_stats = &priv->rq[i].stats;
185 const void *stats_base = (void *)&rq_stats->vs;
186 unsigned int start;
187 size_t offset;
188
189 do {
190 start = u64_stats_fetch_begin_irq(&rq_stats->syncp);
191 for (j = 0; j < VETH_RQ_STATS_LEN; j++) {
192 offset = veth_rq_stats_desc[j].offset;
193 data[idx + j] = *(u64 *)(stats_base + offset);
194 }
195 } while (u64_stats_fetch_retry_irq(&rq_stats->syncp, start));
196 idx += VETH_RQ_STATS_LEN;
197 }
198
199 if (!peer)
200 return;
201
202 rcv_priv = netdev_priv(peer);
203 for (i = 0; i < peer->real_num_rx_queues; i++) {
204 const struct veth_rq_stats *rq_stats = &rcv_priv->rq[i].stats;
205 const void *base = (void *)&rq_stats->vs;
206 unsigned int start, tx_idx = idx;
207 size_t offset;
208
209 tx_idx += (i % dev->real_num_tx_queues) * VETH_TQ_STATS_LEN;
210 do {
211 start = u64_stats_fetch_begin_irq(&rq_stats->syncp);
212 for (j = 0; j < VETH_TQ_STATS_LEN; j++) {
213 offset = veth_tq_stats_desc[j].offset;
214 data[tx_idx + j] += *(u64 *)(base + offset);
215 }
216 } while (u64_stats_fetch_retry_irq(&rq_stats->syncp, start));
217 }
218 }
219
220 static const struct ethtool_ops veth_ethtool_ops = {
221 .get_drvinfo = veth_get_drvinfo,
222 .get_link = ethtool_op_get_link,
223 .get_strings = veth_get_strings,
224 .get_sset_count = veth_get_sset_count,
225 .get_ethtool_stats = veth_get_ethtool_stats,
226 .get_link_ksettings = veth_get_link_ksettings,
227 .get_ts_info = ethtool_op_get_ts_info,
228 };
229
230 /* general routines */
231
232 static bool veth_is_xdp_frame(void *ptr)
233 {
234 return (unsigned long)ptr & VETH_XDP_FLAG;
235 }
236
237 static void *veth_ptr_to_xdp(void *ptr)
238 {
239 return (void *)((unsigned long)ptr & ~VETH_XDP_FLAG);
240 }
241
242 static void *veth_xdp_to_ptr(void *ptr)
243 {
244 return (void *)((unsigned long)ptr | VETH_XDP_FLAG);
245 }
246
247 static void veth_ptr_free(void *ptr)
248 {
249 if (veth_is_xdp_frame(ptr))
250 xdp_return_frame(veth_ptr_to_xdp(ptr));
251 else
252 kfree_skb(ptr);
253 }
254
255 static void __veth_xdp_flush(struct veth_rq *rq)
256 {
257 /* Write ptr_ring before reading rx_notify_masked */
258 smp_mb();
259 if (!rq->rx_notify_masked) {
260 rq->rx_notify_masked = true;
261 napi_schedule(&rq->xdp_napi);
262 }
263 }
264
265 static int veth_xdp_rx(struct veth_rq *rq, struct sk_buff *skb)
266 {
267 if (unlikely(ptr_ring_produce(&rq->xdp_ring, skb))) {
268 dev_kfree_skb_any(skb);
269 return NET_RX_DROP;
270 }
271
272 return NET_RX_SUCCESS;
273 }
274
275 static int veth_forward_skb(struct net_device *dev, struct sk_buff *skb,
276 struct veth_rq *rq, bool xdp)
277 {
278 return __dev_forward_skb(dev, skb) ?: xdp ?
279 veth_xdp_rx(rq, skb) :
280 netif_rx(skb);
281 }
282
283 static netdev_tx_t veth_xmit(struct sk_buff *skb, struct net_device *dev)
284 {
285 struct veth_priv *rcv_priv, *priv = netdev_priv(dev);
286 struct veth_rq *rq = NULL;
287 struct net_device *rcv;
288 int length = skb->len;
289 bool rcv_xdp = false;
290 int rxq;
291
292 rcu_read_lock();
293 rcv = rcu_dereference(priv->peer);
294 if (unlikely(!rcv)) {
295 kfree_skb(skb);
296 goto drop;
297 }
298
299 rcv_priv = netdev_priv(rcv);
300 rxq = skb_get_queue_mapping(skb);
301 if (rxq < rcv->real_num_rx_queues) {
302 rq = &rcv_priv->rq[rxq];
303 rcv_xdp = rcu_access_pointer(rq->xdp_prog);
304 if (rcv_xdp)
305 skb_record_rx_queue(skb, rxq);
306 }
307
308 skb_tx_timestamp(skb);
309 if (likely(veth_forward_skb(rcv, skb, rq, rcv_xdp) == NET_RX_SUCCESS)) {
310 if (!rcv_xdp)
311 dev_lstats_add(dev, length);
312 } else {
313 drop:
314 atomic64_inc(&priv->dropped);
315 }
316
317 if (rcv_xdp)
318 __veth_xdp_flush(rq);
319
320 rcu_read_unlock();
321
322 return NETDEV_TX_OK;
323 }
324
325 static u64 veth_stats_tx(struct net_device *dev, u64 *packets, u64 *bytes)
326 {
327 struct veth_priv *priv = netdev_priv(dev);
328
329 dev_lstats_read(dev, packets, bytes);
330 return atomic64_read(&priv->dropped);
331 }
332
333 static void veth_stats_rx(struct veth_stats *result, struct net_device *dev)
334 {
335 struct veth_priv *priv = netdev_priv(dev);
336 int i;
337
338 result->peer_tq_xdp_xmit_err = 0;
339 result->xdp_packets = 0;
340 result->xdp_tx_err = 0;
341 result->xdp_bytes = 0;
342 result->rx_drops = 0;
343 for (i = 0; i < dev->num_rx_queues; i++) {
344 u64 packets, bytes, drops, xdp_tx_err, peer_tq_xdp_xmit_err;
345 struct veth_rq_stats *stats = &priv->rq[i].stats;
346 unsigned int start;
347
348 do {
349 start = u64_stats_fetch_begin_irq(&stats->syncp);
350 peer_tq_xdp_xmit_err = stats->vs.peer_tq_xdp_xmit_err;
351 xdp_tx_err = stats->vs.xdp_tx_err;
352 packets = stats->vs.xdp_packets;
353 bytes = stats->vs.xdp_bytes;
354 drops = stats->vs.rx_drops;
355 } while (u64_stats_fetch_retry_irq(&stats->syncp, start));
356 result->peer_tq_xdp_xmit_err += peer_tq_xdp_xmit_err;
357 result->xdp_tx_err += xdp_tx_err;
358 result->xdp_packets += packets;
359 result->xdp_bytes += bytes;
360 result->rx_drops += drops;
361 }
362 }
363
364 static void veth_get_stats64(struct net_device *dev,
365 struct rtnl_link_stats64 *tot)
366 {
367 struct veth_priv *priv = netdev_priv(dev);
368 struct net_device *peer;
369 struct veth_stats rx;
370 u64 packets, bytes;
371
372 tot->tx_dropped = veth_stats_tx(dev, &packets, &bytes);
373 tot->tx_bytes = bytes;
374 tot->tx_packets = packets;
375
376 veth_stats_rx(&rx, dev);
377 tot->tx_dropped += rx.xdp_tx_err;
378 tot->rx_dropped = rx.rx_drops + rx.peer_tq_xdp_xmit_err;
379 tot->rx_bytes = rx.xdp_bytes;
380 tot->rx_packets = rx.xdp_packets;
381
382 rcu_read_lock();
383 peer = rcu_dereference(priv->peer);
384 if (peer) {
385 veth_stats_tx(peer, &packets, &bytes);
386 tot->rx_bytes += bytes;
387 tot->rx_packets += packets;
388
389 veth_stats_rx(&rx, peer);
390 tot->tx_dropped += rx.peer_tq_xdp_xmit_err;
391 tot->rx_dropped += rx.xdp_tx_err;
392 tot->tx_bytes += rx.xdp_bytes;
393 tot->tx_packets += rx.xdp_packets;
394 }
395 rcu_read_unlock();
396 }
397
398 /* fake multicast ability */
399 static void veth_set_multicast_list(struct net_device *dev)
400 {
401 }
402
403 static struct sk_buff *veth_build_skb(void *head, int headroom, int len,
404 int buflen)
405 {
406 struct sk_buff *skb;
407
408 skb = build_skb(head, buflen);
409 if (!skb)
410 return NULL;
411
412 skb_reserve(skb, headroom);
413 skb_put(skb, len);
414
415 return skb;
416 }
417
418 static int veth_select_rxq(struct net_device *dev)
419 {
420 return smp_processor_id() % dev->real_num_rx_queues;
421 }
422
423 static int veth_xdp_xmit(struct net_device *dev, int n,
424 struct xdp_frame **frames,
425 u32 flags, bool ndo_xmit)
426 {
427 struct veth_priv *rcv_priv, *priv = netdev_priv(dev);
428 int i, ret = -ENXIO, drops = 0;
429 struct net_device *rcv;
430 unsigned int max_len;
431 struct veth_rq *rq;
432
433 if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK))
434 return -EINVAL;
435
436 rcu_read_lock();
437 rcv = rcu_dereference(priv->peer);
438 if (unlikely(!rcv))
439 goto out;
440
441 rcv_priv = netdev_priv(rcv);
442 rq = &rcv_priv->rq[veth_select_rxq(rcv)];
443 /* Non-NULL xdp_prog ensures that xdp_ring is initialized on receive
444 * side. This means an XDP program is loaded on the peer and the peer
445 * device is up.
446 */
447 if (!rcu_access_pointer(rq->xdp_prog))
448 goto out;
449
450 max_len = rcv->mtu + rcv->hard_header_len + VLAN_HLEN;
451
452 spin_lock(&rq->xdp_ring.producer_lock);
453 for (i = 0; i < n; i++) {
454 struct xdp_frame *frame = frames[i];
455 void *ptr = veth_xdp_to_ptr(frame);
456
457 if (unlikely(frame->len > max_len ||
458 __ptr_ring_produce(&rq->xdp_ring, ptr))) {
459 xdp_return_frame_rx_napi(frame);
460 drops++;
461 }
462 }
463 spin_unlock(&rq->xdp_ring.producer_lock);
464
465 if (flags & XDP_XMIT_FLUSH)
466 __veth_xdp_flush(rq);
467
468 ret = n - drops;
469 if (ndo_xmit) {
470 u64_stats_update_begin(&rq->stats.syncp);
471 rq->stats.vs.peer_tq_xdp_xmit += n - drops;
472 rq->stats.vs.peer_tq_xdp_xmit_err += drops;
473 u64_stats_update_end(&rq->stats.syncp);
474 }
475
476 out:
477 rcu_read_unlock();
478
479 return ret;
480 }
481
482 static int veth_ndo_xdp_xmit(struct net_device *dev, int n,
483 struct xdp_frame **frames, u32 flags)
484 {
485 int err;
486
487 err = veth_xdp_xmit(dev, n, frames, flags, true);
488 if (err < 0) {
489 struct veth_priv *priv = netdev_priv(dev);
490
491 atomic64_add(n, &priv->dropped);
492 }
493
494 return err;
495 }
496
497 static void veth_xdp_flush_bq(struct veth_rq *rq, struct veth_xdp_tx_bq *bq)
498 {
499 int sent, i, err = 0;
500
501 sent = veth_xdp_xmit(rq->dev, bq->count, bq->q, 0, false);
502 if (sent < 0) {
503 err = sent;
504 sent = 0;
505 for (i = 0; i < bq->count; i++)
506 xdp_return_frame(bq->q[i]);
507 }
508 trace_xdp_bulk_tx(rq->dev, sent, bq->count - sent, err);
509
510 u64_stats_update_begin(&rq->stats.syncp);
511 rq->stats.vs.xdp_tx += sent;
512 rq->stats.vs.xdp_tx_err += bq->count - sent;
513 u64_stats_update_end(&rq->stats.syncp);
514
515 bq->count = 0;
516 }
517
518 static void veth_xdp_flush(struct veth_rq *rq, struct veth_xdp_tx_bq *bq)
519 {
520 struct veth_priv *rcv_priv, *priv = netdev_priv(rq->dev);
521 struct net_device *rcv;
522 struct veth_rq *rcv_rq;
523
524 rcu_read_lock();
525 veth_xdp_flush_bq(rq, bq);
526 rcv = rcu_dereference(priv->peer);
527 if (unlikely(!rcv))
528 goto out;
529
530 rcv_priv = netdev_priv(rcv);
531 rcv_rq = &rcv_priv->rq[veth_select_rxq(rcv)];
532 /* xdp_ring is initialized on receive side? */
533 if (unlikely(!rcu_access_pointer(rcv_rq->xdp_prog)))
534 goto out;
535
536 __veth_xdp_flush(rcv_rq);
537 out:
538 rcu_read_unlock();
539 }
540
541 static int veth_xdp_tx(struct veth_rq *rq, struct xdp_buff *xdp,
542 struct veth_xdp_tx_bq *bq)
543 {
544 struct xdp_frame *frame = xdp_convert_buff_to_frame(xdp);
545
546 if (unlikely(!frame))
547 return -EOVERFLOW;
548
549 if (unlikely(bq->count == VETH_XDP_TX_BULK_SIZE))
550 veth_xdp_flush_bq(rq, bq);
551
552 bq->q[bq->count++] = frame;
553
554 return 0;
555 }
556
557 static struct sk_buff *veth_xdp_rcv_one(struct veth_rq *rq,
558 struct xdp_frame *frame,
559 struct veth_xdp_tx_bq *bq,
560 struct veth_stats *stats)
561 {
562 void *hard_start = frame->data - frame->headroom;
563 int len = frame->len, delta = 0;
564 struct xdp_frame orig_frame;
565 struct bpf_prog *xdp_prog;
566 unsigned int headroom;
567 struct sk_buff *skb;
568
569 /* bpf_xdp_adjust_head() assures BPF cannot access xdp_frame area */
570 hard_start -= sizeof(struct xdp_frame);
571
572 rcu_read_lock();
573 xdp_prog = rcu_dereference(rq->xdp_prog);
574 if (likely(xdp_prog)) {
575 struct xdp_buff xdp;
576 u32 act;
577
578 xdp_convert_frame_to_buff(frame, &xdp);
579 xdp.rxq = &rq->xdp_rxq;
580
581 act = bpf_prog_run_xdp(xdp_prog, &xdp);
582
583 switch (act) {
584 case XDP_PASS:
585 delta = frame->data - xdp.data;
586 len = xdp.data_end - xdp.data;
587 break;
588 case XDP_TX:
589 orig_frame = *frame;
590 xdp.rxq->mem = frame->mem;
591 if (unlikely(veth_xdp_tx(rq, &xdp, bq) < 0)) {
592 trace_xdp_exception(rq->dev, xdp_prog, act);
593 frame = &orig_frame;
594 stats->rx_drops++;
595 goto err_xdp;
596 }
597 stats->xdp_tx++;
598 rcu_read_unlock();
599 goto xdp_xmit;
600 case XDP_REDIRECT:
601 orig_frame = *frame;
602 xdp.rxq->mem = frame->mem;
603 if (xdp_do_redirect(rq->dev, &xdp, xdp_prog)) {
604 frame = &orig_frame;
605 stats->rx_drops++;
606 goto err_xdp;
607 }
608 stats->xdp_redirect++;
609 rcu_read_unlock();
610 goto xdp_xmit;
611 default:
612 bpf_warn_invalid_xdp_action(act);
613 /* fall through */
614 case XDP_ABORTED:
615 trace_xdp_exception(rq->dev, xdp_prog, act);
616 /* fall through */
617 case XDP_DROP:
618 stats->xdp_drops++;
619 goto err_xdp;
620 }
621 }
622 rcu_read_unlock();
623
624 headroom = sizeof(struct xdp_frame) + frame->headroom - delta;
625 skb = veth_build_skb(hard_start, headroom, len, frame->frame_sz);
626 if (!skb) {
627 xdp_return_frame(frame);
628 stats->rx_drops++;
629 goto err;
630 }
631
632 xdp_release_frame(frame);
633 xdp_scrub_frame(frame);
634 skb->protocol = eth_type_trans(skb, rq->dev);
635 err:
636 return skb;
637 err_xdp:
638 rcu_read_unlock();
639 xdp_return_frame(frame);
640 xdp_xmit:
641 return NULL;
642 }
643
644 static struct sk_buff *veth_xdp_rcv_skb(struct veth_rq *rq,
645 struct sk_buff *skb,
646 struct veth_xdp_tx_bq *bq,
647 struct veth_stats *stats)
648 {
649 u32 pktlen, headroom, act, metalen;
650 void *orig_data, *orig_data_end;
651 struct bpf_prog *xdp_prog;
652 int mac_len, delta, off;
653 struct xdp_buff xdp;
654
655 skb_orphan(skb);
656
657 rcu_read_lock();
658 xdp_prog = rcu_dereference(rq->xdp_prog);
659 if (unlikely(!xdp_prog)) {
660 rcu_read_unlock();
661 goto out;
662 }
663
664 mac_len = skb->data - skb_mac_header(skb);
665 pktlen = skb->len + mac_len;
666 headroom = skb_headroom(skb) - mac_len;
667
668 if (skb_shared(skb) || skb_head_is_locked(skb) ||
669 skb_is_nonlinear(skb) || headroom < XDP_PACKET_HEADROOM) {
670 struct sk_buff *nskb;
671 int size, head_off;
672 void *head, *start;
673 struct page *page;
674
675 size = SKB_DATA_ALIGN(VETH_XDP_HEADROOM + pktlen) +
676 SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
677 if (size > PAGE_SIZE)
678 goto drop;
679
680 page = alloc_page(GFP_ATOMIC | __GFP_NOWARN);
681 if (!page)
682 goto drop;
683
684 head = page_address(page);
685 start = head + VETH_XDP_HEADROOM;
686 if (skb_copy_bits(skb, -mac_len, start, pktlen)) {
687 page_frag_free(head);
688 goto drop;
689 }
690
691 nskb = veth_build_skb(head, VETH_XDP_HEADROOM + mac_len,
692 skb->len, PAGE_SIZE);
693 if (!nskb) {
694 page_frag_free(head);
695 goto drop;
696 }
697
698 skb_copy_header(nskb, skb);
699 head_off = skb_headroom(nskb) - skb_headroom(skb);
700 skb_headers_offset_update(nskb, head_off);
701 consume_skb(skb);
702 skb = nskb;
703 }
704
705 xdp.data_hard_start = skb->head;
706 xdp.data = skb_mac_header(skb);
707 xdp.data_end = xdp.data + pktlen;
708 xdp.data_meta = xdp.data;
709 xdp.rxq = &rq->xdp_rxq;
710
711 /* SKB "head" area always have tailroom for skb_shared_info */
712 xdp.frame_sz = (void *)skb_end_pointer(skb) - xdp.data_hard_start;
713 xdp.frame_sz += SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
714
715 orig_data = xdp.data;
716 orig_data_end = xdp.data_end;
717
718 act = bpf_prog_run_xdp(xdp_prog, &xdp);
719
720 switch (act) {
721 case XDP_PASS:
722 break;
723 case XDP_TX:
724 get_page(virt_to_page(xdp.data));
725 consume_skb(skb);
726 xdp.rxq->mem = rq->xdp_mem;
727 if (unlikely(veth_xdp_tx(rq, &xdp, bq) < 0)) {
728 trace_xdp_exception(rq->dev, xdp_prog, act);
729 stats->rx_drops++;
730 goto err_xdp;
731 }
732 stats->xdp_tx++;
733 rcu_read_unlock();
734 goto xdp_xmit;
735 case XDP_REDIRECT:
736 get_page(virt_to_page(xdp.data));
737 consume_skb(skb);
738 xdp.rxq->mem = rq->xdp_mem;
739 if (xdp_do_redirect(rq->dev, &xdp, xdp_prog)) {
740 stats->rx_drops++;
741 goto err_xdp;
742 }
743 stats->xdp_redirect++;
744 rcu_read_unlock();
745 goto xdp_xmit;
746 default:
747 bpf_warn_invalid_xdp_action(act);
748 /* fall through */
749 case XDP_ABORTED:
750 trace_xdp_exception(rq->dev, xdp_prog, act);
751 /* fall through */
752 case XDP_DROP:
753 stats->xdp_drops++;
754 goto xdp_drop;
755 }
756 rcu_read_unlock();
757
758 /* check if bpf_xdp_adjust_head was used */
759 delta = orig_data - xdp.data;
760 off = mac_len + delta;
761 if (off > 0)
762 __skb_push(skb, off);
763 else if (off < 0)
764 __skb_pull(skb, -off);
765 skb->mac_header -= delta;
766
767 /* check if bpf_xdp_adjust_tail was used */
768 off = xdp.data_end - orig_data_end;
769 if (off != 0)
770 __skb_put(skb, off); /* positive on grow, negative on shrink */
771 skb->protocol = eth_type_trans(skb, rq->dev);
772
773 metalen = xdp.data - xdp.data_meta;
774 if (metalen)
775 skb_metadata_set(skb, metalen);
776 out:
777 return skb;
778 drop:
779 stats->rx_drops++;
780 xdp_drop:
781 rcu_read_unlock();
782 kfree_skb(skb);
783 return NULL;
784 err_xdp:
785 rcu_read_unlock();
786 page_frag_free(xdp.data);
787 xdp_xmit:
788 return NULL;
789 }
790
791 static int veth_xdp_rcv(struct veth_rq *rq, int budget,
792 struct veth_xdp_tx_bq *bq,
793 struct veth_stats *stats)
794 {
795 int i, done = 0;
796
797 for (i = 0; i < budget; i++) {
798 void *ptr = __ptr_ring_consume(&rq->xdp_ring);
799 struct sk_buff *skb;
800
801 if (!ptr)
802 break;
803
804 if (veth_is_xdp_frame(ptr)) {
805 struct xdp_frame *frame = veth_ptr_to_xdp(ptr);
806
807 stats->xdp_bytes += frame->len;
808 skb = veth_xdp_rcv_one(rq, frame, bq, stats);
809 } else {
810 skb = ptr;
811 stats->xdp_bytes += skb->len;
812 skb = veth_xdp_rcv_skb(rq, skb, bq, stats);
813 }
814
815 if (skb)
816 napi_gro_receive(&rq->xdp_napi, skb);
817
818 done++;
819 }
820
821 u64_stats_update_begin(&rq->stats.syncp);
822 rq->stats.vs.xdp_redirect += stats->xdp_redirect;
823 rq->stats.vs.xdp_bytes += stats->xdp_bytes;
824 rq->stats.vs.xdp_drops += stats->xdp_drops;
825 rq->stats.vs.rx_drops += stats->rx_drops;
826 rq->stats.vs.xdp_packets += done;
827 u64_stats_update_end(&rq->stats.syncp);
828
829 return done;
830 }
831
832 static int veth_poll(struct napi_struct *napi, int budget)
833 {
834 struct veth_rq *rq =
835 container_of(napi, struct veth_rq, xdp_napi);
836 struct veth_stats stats = {};
837 struct veth_xdp_tx_bq bq;
838 int done;
839
840 bq.count = 0;
841
842 xdp_set_return_frame_no_direct();
843 done = veth_xdp_rcv(rq, budget, &bq, &stats);
844
845 if (done < budget && napi_complete_done(napi, done)) {
846 /* Write rx_notify_masked before reading ptr_ring */
847 smp_store_mb(rq->rx_notify_masked, false);
848 if (unlikely(!__ptr_ring_empty(&rq->xdp_ring))) {
849 rq->rx_notify_masked = true;
850 napi_schedule(&rq->xdp_napi);
851 }
852 }
853
854 if (stats.xdp_tx > 0)
855 veth_xdp_flush(rq, &bq);
856 if (stats.xdp_redirect > 0)
857 xdp_do_flush();
858 xdp_clear_return_frame_no_direct();
859
860 return done;
861 }
862
863 static int veth_napi_add(struct net_device *dev)
864 {
865 struct veth_priv *priv = netdev_priv(dev);
866 int err, i;
867
868 for (i = 0; i < dev->real_num_rx_queues; i++) {
869 struct veth_rq *rq = &priv->rq[i];
870
871 err = ptr_ring_init(&rq->xdp_ring, VETH_RING_SIZE, GFP_KERNEL);
872 if (err)
873 goto err_xdp_ring;
874 }
875
876 for (i = 0; i < dev->real_num_rx_queues; i++) {
877 struct veth_rq *rq = &priv->rq[i];
878
879 netif_napi_add(dev, &rq->xdp_napi, veth_poll, NAPI_POLL_WEIGHT);
880 napi_enable(&rq->xdp_napi);
881 }
882
883 return 0;
884 err_xdp_ring:
885 for (i--; i >= 0; i--)
886 ptr_ring_cleanup(&priv->rq[i].xdp_ring, veth_ptr_free);
887
888 return err;
889 }
890
891 static void veth_napi_del(struct net_device *dev)
892 {
893 struct veth_priv *priv = netdev_priv(dev);
894 int i;
895
896 for (i = 0; i < dev->real_num_rx_queues; i++) {
897 struct veth_rq *rq = &priv->rq[i];
898
899 napi_disable(&rq->xdp_napi);
900 napi_hash_del(&rq->xdp_napi);
901 }
902 synchronize_net();
903
904 for (i = 0; i < dev->real_num_rx_queues; i++) {
905 struct veth_rq *rq = &priv->rq[i];
906
907 netif_napi_del(&rq->xdp_napi);
908 rq->rx_notify_masked = false;
909 ptr_ring_cleanup(&rq->xdp_ring, veth_ptr_free);
910 }
911 }
912
913 static int veth_enable_xdp(struct net_device *dev)
914 {
915 struct veth_priv *priv = netdev_priv(dev);
916 int err, i;
917
918 if (!xdp_rxq_info_is_reg(&priv->rq[0].xdp_rxq)) {
919 for (i = 0; i < dev->real_num_rx_queues; i++) {
920 struct veth_rq *rq = &priv->rq[i];
921
922 err = xdp_rxq_info_reg(&rq->xdp_rxq, dev, i);
923 if (err < 0)
924 goto err_rxq_reg;
925
926 err = xdp_rxq_info_reg_mem_model(&rq->xdp_rxq,
927 MEM_TYPE_PAGE_SHARED,
928 NULL);
929 if (err < 0)
930 goto err_reg_mem;
931
932 /* Save original mem info as it can be overwritten */
933 rq->xdp_mem = rq->xdp_rxq.mem;
934 }
935
936 err = veth_napi_add(dev);
937 if (err)
938 goto err_rxq_reg;
939 }
940
941 for (i = 0; i < dev->real_num_rx_queues; i++)
942 rcu_assign_pointer(priv->rq[i].xdp_prog, priv->_xdp_prog);
943
944 return 0;
945 err_reg_mem:
946 xdp_rxq_info_unreg(&priv->rq[i].xdp_rxq);
947 err_rxq_reg:
948 for (i--; i >= 0; i--)
949 xdp_rxq_info_unreg(&priv->rq[i].xdp_rxq);
950
951 return err;
952 }
953
954 static void veth_disable_xdp(struct net_device *dev)
955 {
956 struct veth_priv *priv = netdev_priv(dev);
957 int i;
958
959 for (i = 0; i < dev->real_num_rx_queues; i++)
960 rcu_assign_pointer(priv->rq[i].xdp_prog, NULL);
961 veth_napi_del(dev);
962 for (i = 0; i < dev->real_num_rx_queues; i++) {
963 struct veth_rq *rq = &priv->rq[i];
964
965 rq->xdp_rxq.mem = rq->xdp_mem;
966 xdp_rxq_info_unreg(&rq->xdp_rxq);
967 }
968 }
969
970 static int veth_open(struct net_device *dev)
971 {
972 struct veth_priv *priv = netdev_priv(dev);
973 struct net_device *peer = rtnl_dereference(priv->peer);
974 int err;
975
976 if (!peer)
977 return -ENOTCONN;
978
979 if (priv->_xdp_prog) {
980 err = veth_enable_xdp(dev);
981 if (err)
982 return err;
983 }
984
985 if (peer->flags & IFF_UP) {
986 netif_carrier_on(dev);
987 netif_carrier_on(peer);
988 }
989
990 return 0;
991 }
992
993 static int veth_close(struct net_device *dev)
994 {
995 struct veth_priv *priv = netdev_priv(dev);
996 struct net_device *peer = rtnl_dereference(priv->peer);
997
998 netif_carrier_off(dev);
999 if (peer)
1000 netif_carrier_off(peer);
1001
1002 if (priv->_xdp_prog)
1003 veth_disable_xdp(dev);
1004
1005 return 0;
1006 }
1007
1008 static int is_valid_veth_mtu(int mtu)
1009 {
1010 return mtu >= ETH_MIN_MTU && mtu <= ETH_MAX_MTU;
1011 }
1012
1013 static int veth_alloc_queues(struct net_device *dev)
1014 {
1015 struct veth_priv *priv = netdev_priv(dev);
1016 int i;
1017
1018 priv->rq = kcalloc(dev->num_rx_queues, sizeof(*priv->rq), GFP_KERNEL);
1019 if (!priv->rq)
1020 return -ENOMEM;
1021
1022 for (i = 0; i < dev->num_rx_queues; i++) {
1023 priv->rq[i].dev = dev;
1024 u64_stats_init(&priv->rq[i].stats.syncp);
1025 }
1026
1027 return 0;
1028 }
1029
1030 static void veth_free_queues(struct net_device *dev)
1031 {
1032 struct veth_priv *priv = netdev_priv(dev);
1033
1034 kfree(priv->rq);
1035 }
1036
1037 static int veth_dev_init(struct net_device *dev)
1038 {
1039 int err;
1040
1041 dev->lstats = netdev_alloc_pcpu_stats(struct pcpu_lstats);
1042 if (!dev->lstats)
1043 return -ENOMEM;
1044
1045 err = veth_alloc_queues(dev);
1046 if (err) {
1047 free_percpu(dev->lstats);
1048 return err;
1049 }
1050
1051 return 0;
1052 }
1053
1054 static void veth_dev_free(struct net_device *dev)
1055 {
1056 veth_free_queues(dev);
1057 free_percpu(dev->lstats);
1058 }
1059
1060 #ifdef CONFIG_NET_POLL_CONTROLLER
1061 static void veth_poll_controller(struct net_device *dev)
1062 {
1063 /* veth only receives frames when its peer sends one
1064 * Since it has nothing to do with disabling irqs, we are guaranteed
1065 * never to have pending data when we poll for it so
1066 * there is nothing to do here.
1067 *
1068 * We need this though so netpoll recognizes us as an interface that
1069 * supports polling, which enables bridge devices in virt setups to
1070 * still use netconsole
1071 */
1072 }
1073 #endif /* CONFIG_NET_POLL_CONTROLLER */
1074
1075 static int veth_get_iflink(const struct net_device *dev)
1076 {
1077 struct veth_priv *priv = netdev_priv(dev);
1078 struct net_device *peer;
1079 int iflink;
1080
1081 rcu_read_lock();
1082 peer = rcu_dereference(priv->peer);
1083 iflink = peer ? peer->ifindex : 0;
1084 rcu_read_unlock();
1085
1086 return iflink;
1087 }
1088
1089 static netdev_features_t veth_fix_features(struct net_device *dev,
1090 netdev_features_t features)
1091 {
1092 struct veth_priv *priv = netdev_priv(dev);
1093 struct net_device *peer;
1094
1095 peer = rtnl_dereference(priv->peer);
1096 if (peer) {
1097 struct veth_priv *peer_priv = netdev_priv(peer);
1098
1099 if (peer_priv->_xdp_prog)
1100 features &= ~NETIF_F_GSO_SOFTWARE;
1101 }
1102
1103 return features;
1104 }
1105
1106 static void veth_set_rx_headroom(struct net_device *dev, int new_hr)
1107 {
1108 struct veth_priv *peer_priv, *priv = netdev_priv(dev);
1109 struct net_device *peer;
1110
1111 if (new_hr < 0)
1112 new_hr = 0;
1113
1114 rcu_read_lock();
1115 peer = rcu_dereference(priv->peer);
1116 if (unlikely(!peer))
1117 goto out;
1118
1119 peer_priv = netdev_priv(peer);
1120 priv->requested_headroom = new_hr;
1121 new_hr = max(priv->requested_headroom, peer_priv->requested_headroom);
1122 dev->needed_headroom = new_hr;
1123 peer->needed_headroom = new_hr;
1124
1125 out:
1126 rcu_read_unlock();
1127 }
1128
1129 static int veth_xdp_set(struct net_device *dev, struct bpf_prog *prog,
1130 struct netlink_ext_ack *extack)
1131 {
1132 struct veth_priv *priv = netdev_priv(dev);
1133 struct bpf_prog *old_prog;
1134 struct net_device *peer;
1135 unsigned int max_mtu;
1136 int err;
1137
1138 old_prog = priv->_xdp_prog;
1139 priv->_xdp_prog = prog;
1140 peer = rtnl_dereference(priv->peer);
1141
1142 if (prog) {
1143 if (!peer) {
1144 NL_SET_ERR_MSG_MOD(extack, "Cannot set XDP when peer is detached");
1145 err = -ENOTCONN;
1146 goto err;
1147 }
1148
1149 max_mtu = PAGE_SIZE - VETH_XDP_HEADROOM -
1150 peer->hard_header_len -
1151 SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
1152 if (peer->mtu > max_mtu) {
1153 NL_SET_ERR_MSG_MOD(extack, "Peer MTU is too large to set XDP");
1154 err = -ERANGE;
1155 goto err;
1156 }
1157
1158 if (dev->real_num_rx_queues < peer->real_num_tx_queues) {
1159 NL_SET_ERR_MSG_MOD(extack, "XDP expects number of rx queues not less than peer tx queues");
1160 err = -ENOSPC;
1161 goto err;
1162 }
1163
1164 if (dev->flags & IFF_UP) {
1165 err = veth_enable_xdp(dev);
1166 if (err) {
1167 NL_SET_ERR_MSG_MOD(extack, "Setup for XDP failed");
1168 goto err;
1169 }
1170 }
1171
1172 if (!old_prog) {
1173 peer->hw_features &= ~NETIF_F_GSO_SOFTWARE;
1174 peer->max_mtu = max_mtu;
1175 }
1176 }
1177
1178 if (old_prog) {
1179 if (!prog) {
1180 if (dev->flags & IFF_UP)
1181 veth_disable_xdp(dev);
1182
1183 if (peer) {
1184 peer->hw_features |= NETIF_F_GSO_SOFTWARE;
1185 peer->max_mtu = ETH_MAX_MTU;
1186 }
1187 }
1188 bpf_prog_put(old_prog);
1189 }
1190
1191 if ((!!old_prog ^ !!prog) && peer)
1192 netdev_update_features(peer);
1193
1194 return 0;
1195 err:
1196 priv->_xdp_prog = old_prog;
1197
1198 return err;
1199 }
1200
1201 static int veth_xdp(struct net_device *dev, struct netdev_bpf *xdp)
1202 {
1203 switch (xdp->command) {
1204 case XDP_SETUP_PROG:
1205 return veth_xdp_set(dev, xdp->prog, xdp->extack);
1206 default:
1207 return -EINVAL;
1208 }
1209 }
1210
1211 static const struct net_device_ops veth_netdev_ops = {
1212 .ndo_init = veth_dev_init,
1213 .ndo_open = veth_open,
1214 .ndo_stop = veth_close,
1215 .ndo_start_xmit = veth_xmit,
1216 .ndo_get_stats64 = veth_get_stats64,
1217 .ndo_set_rx_mode = veth_set_multicast_list,
1218 .ndo_set_mac_address = eth_mac_addr,
1219 #ifdef CONFIG_NET_POLL_CONTROLLER
1220 .ndo_poll_controller = veth_poll_controller,
1221 #endif
1222 .ndo_get_iflink = veth_get_iflink,
1223 .ndo_fix_features = veth_fix_features,
1224 .ndo_features_check = passthru_features_check,
1225 .ndo_set_rx_headroom = veth_set_rx_headroom,
1226 .ndo_bpf = veth_xdp,
1227 .ndo_xdp_xmit = veth_ndo_xdp_xmit,
1228 };
1229
1230 #define VETH_FEATURES (NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HW_CSUM | \
1231 NETIF_F_RXCSUM | NETIF_F_SCTP_CRC | NETIF_F_HIGHDMA | \
1232 NETIF_F_GSO_SOFTWARE | NETIF_F_GSO_ENCAP_ALL | \
1233 NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_CTAG_RX | \
1234 NETIF_F_HW_VLAN_STAG_TX | NETIF_F_HW_VLAN_STAG_RX )
1235
1236 static void veth_setup(struct net_device *dev)
1237 {
1238 ether_setup(dev);
1239
1240 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1241 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1242 dev->priv_flags |= IFF_NO_QUEUE;
1243 dev->priv_flags |= IFF_PHONY_HEADROOM;
1244
1245 dev->netdev_ops = &veth_netdev_ops;
1246 dev->ethtool_ops = &veth_ethtool_ops;
1247 dev->features |= NETIF_F_LLTX;
1248 dev->features |= VETH_FEATURES;
1249 dev->vlan_features = dev->features &
1250 ~(NETIF_F_HW_VLAN_CTAG_TX |
1251 NETIF_F_HW_VLAN_STAG_TX |
1252 NETIF_F_HW_VLAN_CTAG_RX |
1253 NETIF_F_HW_VLAN_STAG_RX);
1254 dev->needs_free_netdev = true;
1255 dev->priv_destructor = veth_dev_free;
1256 dev->max_mtu = ETH_MAX_MTU;
1257
1258 dev->hw_features = VETH_FEATURES;
1259 dev->hw_enc_features = VETH_FEATURES;
1260 dev->mpls_features = NETIF_F_HW_CSUM | NETIF_F_GSO_SOFTWARE;
1261 }
1262
1263 /*
1264 * netlink interface
1265 */
1266
1267 static int veth_validate(struct nlattr *tb[], struct nlattr *data[],
1268 struct netlink_ext_ack *extack)
1269 {
1270 if (tb[IFLA_ADDRESS]) {
1271 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1272 return -EINVAL;
1273 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1274 return -EADDRNOTAVAIL;
1275 }
1276 if (tb[IFLA_MTU]) {
1277 if (!is_valid_veth_mtu(nla_get_u32(tb[IFLA_MTU])))
1278 return -EINVAL;
1279 }
1280 return 0;
1281 }
1282
1283 static struct rtnl_link_ops veth_link_ops;
1284
1285 static int veth_newlink(struct net *src_net, struct net_device *dev,
1286 struct nlattr *tb[], struct nlattr *data[],
1287 struct netlink_ext_ack *extack)
1288 {
1289 int err;
1290 struct net_device *peer;
1291 struct veth_priv *priv;
1292 char ifname[IFNAMSIZ];
1293 struct nlattr *peer_tb[IFLA_MAX + 1], **tbp;
1294 unsigned char name_assign_type;
1295 struct ifinfomsg *ifmp;
1296 struct net *net;
1297
1298 /*
1299 * create and register peer first
1300 */
1301 if (data != NULL && data[VETH_INFO_PEER] != NULL) {
1302 struct nlattr *nla_peer;
1303
1304 nla_peer = data[VETH_INFO_PEER];
1305 ifmp = nla_data(nla_peer);
1306 err = rtnl_nla_parse_ifla(peer_tb,
1307 nla_data(nla_peer) + sizeof(struct ifinfomsg),
1308 nla_len(nla_peer) - sizeof(struct ifinfomsg),
1309 NULL);
1310 if (err < 0)
1311 return err;
1312
1313 err = veth_validate(peer_tb, NULL, extack);
1314 if (err < 0)
1315 return err;
1316
1317 tbp = peer_tb;
1318 } else {
1319 ifmp = NULL;
1320 tbp = tb;
1321 }
1322
1323 if (ifmp && tbp[IFLA_IFNAME]) {
1324 nla_strlcpy(ifname, tbp[IFLA_IFNAME], IFNAMSIZ);
1325 name_assign_type = NET_NAME_USER;
1326 } else {
1327 snprintf(ifname, IFNAMSIZ, DRV_NAME "%%d");
1328 name_assign_type = NET_NAME_ENUM;
1329 }
1330
1331 net = rtnl_link_get_net(src_net, tbp);
1332 if (IS_ERR(net))
1333 return PTR_ERR(net);
1334
1335 peer = rtnl_create_link(net, ifname, name_assign_type,
1336 &veth_link_ops, tbp, extack);
1337 if (IS_ERR(peer)) {
1338 put_net(net);
1339 return PTR_ERR(peer);
1340 }
1341
1342 if (!ifmp || !tbp[IFLA_ADDRESS])
1343 eth_hw_addr_random(peer);
1344
1345 if (ifmp && (dev->ifindex != 0))
1346 peer->ifindex = ifmp->ifi_index;
1347
1348 peer->gso_max_size = dev->gso_max_size;
1349 peer->gso_max_segs = dev->gso_max_segs;
1350
1351 err = register_netdevice(peer);
1352 put_net(net);
1353 net = NULL;
1354 if (err < 0)
1355 goto err_register_peer;
1356
1357 netif_carrier_off(peer);
1358
1359 err = rtnl_configure_link(peer, ifmp);
1360 if (err < 0)
1361 goto err_configure_peer;
1362
1363 /*
1364 * register dev last
1365 *
1366 * note, that since we've registered new device the dev's name
1367 * should be re-allocated
1368 */
1369
1370 if (tb[IFLA_ADDRESS] == NULL)
1371 eth_hw_addr_random(dev);
1372
1373 if (tb[IFLA_IFNAME])
1374 nla_strlcpy(dev->name, tb[IFLA_IFNAME], IFNAMSIZ);
1375 else
1376 snprintf(dev->name, IFNAMSIZ, DRV_NAME "%%d");
1377
1378 err = register_netdevice(dev);
1379 if (err < 0)
1380 goto err_register_dev;
1381
1382 netif_carrier_off(dev);
1383
1384 /*
1385 * tie the deviced together
1386 */
1387
1388 priv = netdev_priv(dev);
1389 rcu_assign_pointer(priv->peer, peer);
1390
1391 priv = netdev_priv(peer);
1392 rcu_assign_pointer(priv->peer, dev);
1393
1394 return 0;
1395
1396 err_register_dev:
1397 /* nothing to do */
1398 err_configure_peer:
1399 unregister_netdevice(peer);
1400 return err;
1401
1402 err_register_peer:
1403 free_netdev(peer);
1404 return err;
1405 }
1406
1407 static void veth_dellink(struct net_device *dev, struct list_head *head)
1408 {
1409 struct veth_priv *priv;
1410 struct net_device *peer;
1411
1412 priv = netdev_priv(dev);
1413 peer = rtnl_dereference(priv->peer);
1414
1415 /* Note : dellink() is called from default_device_exit_batch(),
1416 * before a rcu_synchronize() point. The devices are guaranteed
1417 * not being freed before one RCU grace period.
1418 */
1419 RCU_INIT_POINTER(priv->peer, NULL);
1420 unregister_netdevice_queue(dev, head);
1421
1422 if (peer) {
1423 priv = netdev_priv(peer);
1424 RCU_INIT_POINTER(priv->peer, NULL);
1425 unregister_netdevice_queue(peer, head);
1426 }
1427 }
1428
1429 static const struct nla_policy veth_policy[VETH_INFO_MAX + 1] = {
1430 [VETH_INFO_PEER] = { .len = sizeof(struct ifinfomsg) },
1431 };
1432
1433 static struct net *veth_get_link_net(const struct net_device *dev)
1434 {
1435 struct veth_priv *priv = netdev_priv(dev);
1436 struct net_device *peer = rtnl_dereference(priv->peer);
1437
1438 return peer ? dev_net(peer) : dev_net(dev);
1439 }
1440
1441 static struct rtnl_link_ops veth_link_ops = {
1442 .kind = DRV_NAME,
1443 .priv_size = sizeof(struct veth_priv),
1444 .setup = veth_setup,
1445 .validate = veth_validate,
1446 .newlink = veth_newlink,
1447 .dellink = veth_dellink,
1448 .policy = veth_policy,
1449 .maxtype = VETH_INFO_MAX,
1450 .get_link_net = veth_get_link_net,
1451 };
1452
1453 /*
1454 * init/fini
1455 */
1456
1457 static __init int veth_init(void)
1458 {
1459 return rtnl_link_register(&veth_link_ops);
1460 }
1461
1462 static __exit void veth_exit(void)
1463 {
1464 rtnl_link_unregister(&veth_link_ops);
1465 }
1466
1467 module_init(veth_init);
1468 module_exit(veth_exit);
1469
1470 MODULE_DESCRIPTION("Virtual Ethernet Tunnel");
1471 MODULE_LICENSE("GPL v2");
1472 MODULE_ALIAS_RTNL_LINK(DRV_NAME);
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