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Merge tag 'block-5.11-2021-01-10' of git://git.kernel.dk/linux-block
[linux/fpc-iii.git] / drivers / net / veth.c
blob02bfcdf50a7ac60e14aeeaec242eeba7c6b7c88c
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 struct xdp_frame *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(struct xdp_frame *xdp)
243 {
244 return (void *)((unsigned long)xdp | 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 struct net_device *veth_peer_dev(struct net_device *dev)
424 {
425 struct veth_priv *priv = netdev_priv(dev);
426
427 /* Callers must be under RCU read side. */
428 return rcu_dereference(priv->peer);
429 }
430
431 static int veth_xdp_xmit(struct net_device *dev, int n,
432 struct xdp_frame **frames,
433 u32 flags, bool ndo_xmit)
434 {
435 struct veth_priv *rcv_priv, *priv = netdev_priv(dev);
436 int i, ret = -ENXIO, drops = 0;
437 struct net_device *rcv;
438 unsigned int max_len;
439 struct veth_rq *rq;
440
441 if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK))
442 return -EINVAL;
443
444 rcu_read_lock();
445 rcv = rcu_dereference(priv->peer);
446 if (unlikely(!rcv))
447 goto out;
448
449 rcv_priv = netdev_priv(rcv);
450 rq = &rcv_priv->rq[veth_select_rxq(rcv)];
451 /* Non-NULL xdp_prog ensures that xdp_ring is initialized on receive
452 * side. This means an XDP program is loaded on the peer and the peer
453 * device is up.
454 */
455 if (!rcu_access_pointer(rq->xdp_prog))
456 goto out;
457
458 max_len = rcv->mtu + rcv->hard_header_len + VLAN_HLEN;
459
460 spin_lock(&rq->xdp_ring.producer_lock);
461 for (i = 0; i < n; i++) {
462 struct xdp_frame *frame = frames[i];
463 void *ptr = veth_xdp_to_ptr(frame);
464
465 if (unlikely(frame->len > max_len ||
466 __ptr_ring_produce(&rq->xdp_ring, ptr))) {
467 xdp_return_frame_rx_napi(frame);
468 drops++;
469 }
470 }
471 spin_unlock(&rq->xdp_ring.producer_lock);
472
473 if (flags & XDP_XMIT_FLUSH)
474 __veth_xdp_flush(rq);
475
476 ret = n - drops;
477 if (ndo_xmit) {
478 u64_stats_update_begin(&rq->stats.syncp);
479 rq->stats.vs.peer_tq_xdp_xmit += n - drops;
480 rq->stats.vs.peer_tq_xdp_xmit_err += drops;
481 u64_stats_update_end(&rq->stats.syncp);
482 }
483
484 out:
485 rcu_read_unlock();
486
487 return ret;
488 }
489
490 static int veth_ndo_xdp_xmit(struct net_device *dev, int n,
491 struct xdp_frame **frames, u32 flags)
492 {
493 int err;
494
495 err = veth_xdp_xmit(dev, n, frames, flags, true);
496 if (err < 0) {
497 struct veth_priv *priv = netdev_priv(dev);
498
499 atomic64_add(n, &priv->dropped);
500 }
501
502 return err;
503 }
504
505 static void veth_xdp_flush_bq(struct veth_rq *rq, struct veth_xdp_tx_bq *bq)
506 {
507 int sent, i, err = 0;
508
509 sent = veth_xdp_xmit(rq->dev, bq->count, bq->q, 0, false);
510 if (sent < 0) {
511 err = sent;
512 sent = 0;
513 for (i = 0; i < bq->count; i++)
514 xdp_return_frame(bq->q[i]);
515 }
516 trace_xdp_bulk_tx(rq->dev, sent, bq->count - sent, err);
517
518 u64_stats_update_begin(&rq->stats.syncp);
519 rq->stats.vs.xdp_tx += sent;
520 rq->stats.vs.xdp_tx_err += bq->count - sent;
521 u64_stats_update_end(&rq->stats.syncp);
522
523 bq->count = 0;
524 }
525
526 static void veth_xdp_flush(struct veth_rq *rq, struct veth_xdp_tx_bq *bq)
527 {
528 struct veth_priv *rcv_priv, *priv = netdev_priv(rq->dev);
529 struct net_device *rcv;
530 struct veth_rq *rcv_rq;
531
532 rcu_read_lock();
533 veth_xdp_flush_bq(rq, bq);
534 rcv = rcu_dereference(priv->peer);
535 if (unlikely(!rcv))
536 goto out;
537
538 rcv_priv = netdev_priv(rcv);
539 rcv_rq = &rcv_priv->rq[veth_select_rxq(rcv)];
540 /* xdp_ring is initialized on receive side? */
541 if (unlikely(!rcu_access_pointer(rcv_rq->xdp_prog)))
542 goto out;
543
544 __veth_xdp_flush(rcv_rq);
545 out:
546 rcu_read_unlock();
547 }
548
549 static int veth_xdp_tx(struct veth_rq *rq, struct xdp_buff *xdp,
550 struct veth_xdp_tx_bq *bq)
551 {
552 struct xdp_frame *frame = xdp_convert_buff_to_frame(xdp);
553
554 if (unlikely(!frame))
555 return -EOVERFLOW;
556
557 if (unlikely(bq->count == VETH_XDP_TX_BULK_SIZE))
558 veth_xdp_flush_bq(rq, bq);
559
560 bq->q[bq->count++] = frame;
561
562 return 0;
563 }
564
565 static struct sk_buff *veth_xdp_rcv_one(struct veth_rq *rq,
566 struct xdp_frame *frame,
567 struct veth_xdp_tx_bq *bq,
568 struct veth_stats *stats)
569 {
570 void *hard_start = frame->data - frame->headroom;
571 int len = frame->len, delta = 0;
572 struct xdp_frame orig_frame;
573 struct bpf_prog *xdp_prog;
574 unsigned int headroom;
575 struct sk_buff *skb;
576
577 /* bpf_xdp_adjust_head() assures BPF cannot access xdp_frame area */
578 hard_start -= sizeof(struct xdp_frame);
579
580 rcu_read_lock();
581 xdp_prog = rcu_dereference(rq->xdp_prog);
582 if (likely(xdp_prog)) {
583 struct xdp_buff xdp;
584 u32 act;
585
586 xdp_convert_frame_to_buff(frame, &xdp);
587 xdp.rxq = &rq->xdp_rxq;
588
589 act = bpf_prog_run_xdp(xdp_prog, &xdp);
590
591 switch (act) {
592 case XDP_PASS:
593 delta = frame->data - xdp.data;
594 len = xdp.data_end - xdp.data;
595 break;
596 case XDP_TX:
597 orig_frame = *frame;
598 xdp.rxq->mem = frame->mem;
599 if (unlikely(veth_xdp_tx(rq, &xdp, bq) < 0)) {
600 trace_xdp_exception(rq->dev, xdp_prog, act);
601 frame = &orig_frame;
602 stats->rx_drops++;
603 goto err_xdp;
604 }
605 stats->xdp_tx++;
606 rcu_read_unlock();
607 goto xdp_xmit;
608 case XDP_REDIRECT:
609 orig_frame = *frame;
610 xdp.rxq->mem = frame->mem;
611 if (xdp_do_redirect(rq->dev, &xdp, xdp_prog)) {
612 frame = &orig_frame;
613 stats->rx_drops++;
614 goto err_xdp;
615 }
616 stats->xdp_redirect++;
617 rcu_read_unlock();
618 goto xdp_xmit;
619 default:
620 bpf_warn_invalid_xdp_action(act);
621 fallthrough;
622 case XDP_ABORTED:
623 trace_xdp_exception(rq->dev, xdp_prog, act);
624 fallthrough;
625 case XDP_DROP:
626 stats->xdp_drops++;
627 goto err_xdp;
628 }
629 }
630 rcu_read_unlock();
631
632 headroom = sizeof(struct xdp_frame) + frame->headroom - delta;
633 skb = veth_build_skb(hard_start, headroom, len, frame->frame_sz);
634 if (!skb) {
635 xdp_return_frame(frame);
636 stats->rx_drops++;
637 goto err;
638 }
639
640 xdp_release_frame(frame);
641 xdp_scrub_frame(frame);
642 skb->protocol = eth_type_trans(skb, rq->dev);
643 err:
644 return skb;
645 err_xdp:
646 rcu_read_unlock();
647 xdp_return_frame(frame);
648 xdp_xmit:
649 return NULL;
650 }
651
652 static struct sk_buff *veth_xdp_rcv_skb(struct veth_rq *rq,
653 struct sk_buff *skb,
654 struct veth_xdp_tx_bq *bq,
655 struct veth_stats *stats)
656 {
657 u32 pktlen, headroom, act, metalen;
658 void *orig_data, *orig_data_end;
659 struct bpf_prog *xdp_prog;
660 int mac_len, delta, off;
661 struct xdp_buff xdp;
662
663 skb_orphan(skb);
664
665 rcu_read_lock();
666 xdp_prog = rcu_dereference(rq->xdp_prog);
667 if (unlikely(!xdp_prog)) {
668 rcu_read_unlock();
669 goto out;
670 }
671
672 mac_len = skb->data - skb_mac_header(skb);
673 pktlen = skb->len + mac_len;
674 headroom = skb_headroom(skb) - mac_len;
675
676 if (skb_shared(skb) || skb_head_is_locked(skb) ||
677 skb_is_nonlinear(skb) || headroom < XDP_PACKET_HEADROOM) {
678 struct sk_buff *nskb;
679 int size, head_off;
680 void *head, *start;
681 struct page *page;
682
683 size = SKB_DATA_ALIGN(VETH_XDP_HEADROOM + pktlen) +
684 SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
685 if (size > PAGE_SIZE)
686 goto drop;
687
688 page = alloc_page(GFP_ATOMIC | __GFP_NOWARN);
689 if (!page)
690 goto drop;
691
692 head = page_address(page);
693 start = head + VETH_XDP_HEADROOM;
694 if (skb_copy_bits(skb, -mac_len, start, pktlen)) {
695 page_frag_free(head);
696 goto drop;
697 }
698
699 nskb = veth_build_skb(head, VETH_XDP_HEADROOM + mac_len,
700 skb->len, PAGE_SIZE);
701 if (!nskb) {
702 page_frag_free(head);
703 goto drop;
704 }
705
706 skb_copy_header(nskb, skb);
707 head_off = skb_headroom(nskb) - skb_headroom(skb);
708 skb_headers_offset_update(nskb, head_off);
709 consume_skb(skb);
710 skb = nskb;
711 }
712
713 xdp.data_hard_start = skb->head;
714 xdp.data = skb_mac_header(skb);
715 xdp.data_end = xdp.data + pktlen;
716 xdp.data_meta = xdp.data;
717 xdp.rxq = &rq->xdp_rxq;
718
719 /* SKB "head" area always have tailroom for skb_shared_info */
720 xdp.frame_sz = (void *)skb_end_pointer(skb) - xdp.data_hard_start;
721 xdp.frame_sz += SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
722
723 orig_data = xdp.data;
724 orig_data_end = xdp.data_end;
725
726 act = bpf_prog_run_xdp(xdp_prog, &xdp);
727
728 switch (act) {
729 case XDP_PASS:
730 break;
731 case XDP_TX:
732 get_page(virt_to_page(xdp.data));
733 consume_skb(skb);
734 xdp.rxq->mem = rq->xdp_mem;
735 if (unlikely(veth_xdp_tx(rq, &xdp, bq) < 0)) {
736 trace_xdp_exception(rq->dev, xdp_prog, act);
737 stats->rx_drops++;
738 goto err_xdp;
739 }
740 stats->xdp_tx++;
741 rcu_read_unlock();
742 goto xdp_xmit;
743 case XDP_REDIRECT:
744 get_page(virt_to_page(xdp.data));
745 consume_skb(skb);
746 xdp.rxq->mem = rq->xdp_mem;
747 if (xdp_do_redirect(rq->dev, &xdp, xdp_prog)) {
748 stats->rx_drops++;
749 goto err_xdp;
750 }
751 stats->xdp_redirect++;
752 rcu_read_unlock();
753 goto xdp_xmit;
754 default:
755 bpf_warn_invalid_xdp_action(act);
756 fallthrough;
757 case XDP_ABORTED:
758 trace_xdp_exception(rq->dev, xdp_prog, act);
759 fallthrough;
760 case XDP_DROP:
761 stats->xdp_drops++;
762 goto xdp_drop;
763 }
764 rcu_read_unlock();
765
766 /* check if bpf_xdp_adjust_head was used */
767 delta = orig_data - xdp.data;
768 off = mac_len + delta;
769 if (off > 0)
770 __skb_push(skb, off);
771 else if (off < 0)
772 __skb_pull(skb, -off);
773 skb->mac_header -= delta;
774
775 /* check if bpf_xdp_adjust_tail was used */
776 off = xdp.data_end - orig_data_end;
777 if (off != 0)
778 __skb_put(skb, off); /* positive on grow, negative on shrink */
779 skb->protocol = eth_type_trans(skb, rq->dev);
780
781 metalen = xdp.data - xdp.data_meta;
782 if (metalen)
783 skb_metadata_set(skb, metalen);
784 out:
785 return skb;
786 drop:
787 stats->rx_drops++;
788 xdp_drop:
789 rcu_read_unlock();
790 kfree_skb(skb);
791 return NULL;
792 err_xdp:
793 rcu_read_unlock();
794 page_frag_free(xdp.data);
795 xdp_xmit:
796 return NULL;
797 }
798
799 static int veth_xdp_rcv(struct veth_rq *rq, int budget,
800 struct veth_xdp_tx_bq *bq,
801 struct veth_stats *stats)
802 {
803 int i, done = 0;
804
805 for (i = 0; i < budget; i++) {
806 void *ptr = __ptr_ring_consume(&rq->xdp_ring);
807 struct sk_buff *skb;
808
809 if (!ptr)
810 break;
811
812 if (veth_is_xdp_frame(ptr)) {
813 struct xdp_frame *frame = veth_ptr_to_xdp(ptr);
814
815 stats->xdp_bytes += frame->len;
816 skb = veth_xdp_rcv_one(rq, frame, bq, stats);
817 } else {
818 skb = ptr;
819 stats->xdp_bytes += skb->len;
820 skb = veth_xdp_rcv_skb(rq, skb, bq, stats);
821 }
822
823 if (skb)
824 napi_gro_receive(&rq->xdp_napi, skb);
825
826 done++;
827 }
828
829 u64_stats_update_begin(&rq->stats.syncp);
830 rq->stats.vs.xdp_redirect += stats->xdp_redirect;
831 rq->stats.vs.xdp_bytes += stats->xdp_bytes;
832 rq->stats.vs.xdp_drops += stats->xdp_drops;
833 rq->stats.vs.rx_drops += stats->rx_drops;
834 rq->stats.vs.xdp_packets += done;
835 u64_stats_update_end(&rq->stats.syncp);
836
837 return done;
838 }
839
840 static int veth_poll(struct napi_struct *napi, int budget)
841 {
842 struct veth_rq *rq =
843 container_of(napi, struct veth_rq, xdp_napi);
844 struct veth_stats stats = {};
845 struct veth_xdp_tx_bq bq;
846 int done;
847
848 bq.count = 0;
849
850 xdp_set_return_frame_no_direct();
851 done = veth_xdp_rcv(rq, budget, &bq, &stats);
852
853 if (done < budget && napi_complete_done(napi, done)) {
854 /* Write rx_notify_masked before reading ptr_ring */
855 smp_store_mb(rq->rx_notify_masked, false);
856 if (unlikely(!__ptr_ring_empty(&rq->xdp_ring))) {
857 rq->rx_notify_masked = true;
858 napi_schedule(&rq->xdp_napi);
859 }
860 }
861
862 if (stats.xdp_tx > 0)
863 veth_xdp_flush(rq, &bq);
864 if (stats.xdp_redirect > 0)
865 xdp_do_flush();
866 xdp_clear_return_frame_no_direct();
867
868 return done;
869 }
870
871 static int veth_napi_add(struct net_device *dev)
872 {
873 struct veth_priv *priv = netdev_priv(dev);
874 int err, i;
875
876 for (i = 0; i < dev->real_num_rx_queues; i++) {
877 struct veth_rq *rq = &priv->rq[i];
878
879 err = ptr_ring_init(&rq->xdp_ring, VETH_RING_SIZE, GFP_KERNEL);
880 if (err)
881 goto err_xdp_ring;
882 }
883
884 for (i = 0; i < dev->real_num_rx_queues; i++) {
885 struct veth_rq *rq = &priv->rq[i];
886
887 napi_enable(&rq->xdp_napi);
888 }
889
890 return 0;
891 err_xdp_ring:
892 for (i--; i >= 0; i--)
893 ptr_ring_cleanup(&priv->rq[i].xdp_ring, veth_ptr_free);
894
895 return err;
896 }
897
898 static void veth_napi_del(struct net_device *dev)
899 {
900 struct veth_priv *priv = netdev_priv(dev);
901 int i;
902
903 for (i = 0; i < dev->real_num_rx_queues; i++) {
904 struct veth_rq *rq = &priv->rq[i];
905
906 napi_disable(&rq->xdp_napi);
907 __netif_napi_del(&rq->xdp_napi);
908 }
909 synchronize_net();
910
911 for (i = 0; i < dev->real_num_rx_queues; i++) {
912 struct veth_rq *rq = &priv->rq[i];
913
914 rq->rx_notify_masked = false;
915 ptr_ring_cleanup(&rq->xdp_ring, veth_ptr_free);
916 }
917 }
918
919 static int veth_enable_xdp(struct net_device *dev)
920 {
921 struct veth_priv *priv = netdev_priv(dev);
922 int err, i;
923
924 if (!xdp_rxq_info_is_reg(&priv->rq[0].xdp_rxq)) {
925 for (i = 0; i < dev->real_num_rx_queues; i++) {
926 struct veth_rq *rq = &priv->rq[i];
927
928 netif_napi_add(dev, &rq->xdp_napi, veth_poll, NAPI_POLL_WEIGHT);
929 err = xdp_rxq_info_reg(&rq->xdp_rxq, dev, i, rq->xdp_napi.napi_id);
930 if (err < 0)
931 goto err_rxq_reg;
932
933 err = xdp_rxq_info_reg_mem_model(&rq->xdp_rxq,
934 MEM_TYPE_PAGE_SHARED,
935 NULL);
936 if (err < 0)
937 goto err_reg_mem;
938
939 /* Save original mem info as it can be overwritten */
940 rq->xdp_mem = rq->xdp_rxq.mem;
941 }
942
943 err = veth_napi_add(dev);
944 if (err)
945 goto err_rxq_reg;
946 }
947
948 for (i = 0; i < dev->real_num_rx_queues; i++)
949 rcu_assign_pointer(priv->rq[i].xdp_prog, priv->_xdp_prog);
950
951 return 0;
952 err_reg_mem:
953 xdp_rxq_info_unreg(&priv->rq[i].xdp_rxq);
954 err_rxq_reg:
955 for (i--; i >= 0; i--) {
956 struct veth_rq *rq = &priv->rq[i];
957
958 xdp_rxq_info_unreg(&rq->xdp_rxq);
959 netif_napi_del(&rq->xdp_napi);
960 }
961
962 return err;
963 }
964
965 static void veth_disable_xdp(struct net_device *dev)
966 {
967 struct veth_priv *priv = netdev_priv(dev);
968 int i;
969
970 for (i = 0; i < dev->real_num_rx_queues; i++)
971 rcu_assign_pointer(priv->rq[i].xdp_prog, NULL);
972 veth_napi_del(dev);
973 for (i = 0; i < dev->real_num_rx_queues; i++) {
974 struct veth_rq *rq = &priv->rq[i];
975
976 rq->xdp_rxq.mem = rq->xdp_mem;
977 xdp_rxq_info_unreg(&rq->xdp_rxq);
978 }
979 }
980
981 static int veth_open(struct net_device *dev)
982 {
983 struct veth_priv *priv = netdev_priv(dev);
984 struct net_device *peer = rtnl_dereference(priv->peer);
985 int err;
986
987 if (!peer)
988 return -ENOTCONN;
989
990 if (priv->_xdp_prog) {
991 err = veth_enable_xdp(dev);
992 if (err)
993 return err;
994 }
995
996 if (peer->flags & IFF_UP) {
997 netif_carrier_on(dev);
998 netif_carrier_on(peer);
999 }
1000
1001 return 0;
1002 }
1003
1004 static int veth_close(struct net_device *dev)
1005 {
1006 struct veth_priv *priv = netdev_priv(dev);
1007 struct net_device *peer = rtnl_dereference(priv->peer);
1008
1009 netif_carrier_off(dev);
1010 if (peer)
1011 netif_carrier_off(peer);
1012
1013 if (priv->_xdp_prog)
1014 veth_disable_xdp(dev);
1015
1016 return 0;
1017 }
1018
1019 static int is_valid_veth_mtu(int mtu)
1020 {
1021 return mtu >= ETH_MIN_MTU && mtu <= ETH_MAX_MTU;
1022 }
1023
1024 static int veth_alloc_queues(struct net_device *dev)
1025 {
1026 struct veth_priv *priv = netdev_priv(dev);
1027 int i;
1028
1029 priv->rq = kcalloc(dev->num_rx_queues, sizeof(*priv->rq), GFP_KERNEL);
1030 if (!priv->rq)
1031 return -ENOMEM;
1032
1033 for (i = 0; i < dev->num_rx_queues; i++) {
1034 priv->rq[i].dev = dev;
1035 u64_stats_init(&priv->rq[i].stats.syncp);
1036 }
1037
1038 return 0;
1039 }
1040
1041 static void veth_free_queues(struct net_device *dev)
1042 {
1043 struct veth_priv *priv = netdev_priv(dev);
1044
1045 kfree(priv->rq);
1046 }
1047
1048 static int veth_dev_init(struct net_device *dev)
1049 {
1050 int err;
1051
1052 dev->lstats = netdev_alloc_pcpu_stats(struct pcpu_lstats);
1053 if (!dev->lstats)
1054 return -ENOMEM;
1055
1056 err = veth_alloc_queues(dev);
1057 if (err) {
1058 free_percpu(dev->lstats);
1059 return err;
1060 }
1061
1062 return 0;
1063 }
1064
1065 static void veth_dev_free(struct net_device *dev)
1066 {
1067 veth_free_queues(dev);
1068 free_percpu(dev->lstats);
1069 }
1070
1071 #ifdef CONFIG_NET_POLL_CONTROLLER
1072 static void veth_poll_controller(struct net_device *dev)
1073 {
1074 /* veth only receives frames when its peer sends one
1075 * Since it has nothing to do with disabling irqs, we are guaranteed
1076 * never to have pending data when we poll for it so
1077 * there is nothing to do here.
1078 *
1079 * We need this though so netpoll recognizes us as an interface that
1080 * supports polling, which enables bridge devices in virt setups to
1081 * still use netconsole
1082 */
1083 }
1084 #endif /* CONFIG_NET_POLL_CONTROLLER */
1085
1086 static int veth_get_iflink(const struct net_device *dev)
1087 {
1088 struct veth_priv *priv = netdev_priv(dev);
1089 struct net_device *peer;
1090 int iflink;
1091
1092 rcu_read_lock();
1093 peer = rcu_dereference(priv->peer);
1094 iflink = peer ? peer->ifindex : 0;
1095 rcu_read_unlock();
1096
1097 return iflink;
1098 }
1099
1100 static netdev_features_t veth_fix_features(struct net_device *dev,
1101 netdev_features_t features)
1102 {
1103 struct veth_priv *priv = netdev_priv(dev);
1104 struct net_device *peer;
1105
1106 peer = rtnl_dereference(priv->peer);
1107 if (peer) {
1108 struct veth_priv *peer_priv = netdev_priv(peer);
1109
1110 if (peer_priv->_xdp_prog)
1111 features &= ~NETIF_F_GSO_SOFTWARE;
1112 }
1113
1114 return features;
1115 }
1116
1117 static void veth_set_rx_headroom(struct net_device *dev, int new_hr)
1118 {
1119 struct veth_priv *peer_priv, *priv = netdev_priv(dev);
1120 struct net_device *peer;
1121
1122 if (new_hr < 0)
1123 new_hr = 0;
1124
1125 rcu_read_lock();
1126 peer = rcu_dereference(priv->peer);
1127 if (unlikely(!peer))
1128 goto out;
1129
1130 peer_priv = netdev_priv(peer);
1131 priv->requested_headroom = new_hr;
1132 new_hr = max(priv->requested_headroom, peer_priv->requested_headroom);
1133 dev->needed_headroom = new_hr;
1134 peer->needed_headroom = new_hr;
1135
1136 out:
1137 rcu_read_unlock();
1138 }
1139
1140 static int veth_xdp_set(struct net_device *dev, struct bpf_prog *prog,
1141 struct netlink_ext_ack *extack)
1142 {
1143 struct veth_priv *priv = netdev_priv(dev);
1144 struct bpf_prog *old_prog;
1145 struct net_device *peer;
1146 unsigned int max_mtu;
1147 int err;
1148
1149 old_prog = priv->_xdp_prog;
1150 priv->_xdp_prog = prog;
1151 peer = rtnl_dereference(priv->peer);
1152
1153 if (prog) {
1154 if (!peer) {
1155 NL_SET_ERR_MSG_MOD(extack, "Cannot set XDP when peer is detached");
1156 err = -ENOTCONN;
1157 goto err;
1158 }
1159
1160 max_mtu = PAGE_SIZE - VETH_XDP_HEADROOM -
1161 peer->hard_header_len -
1162 SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
1163 if (peer->mtu > max_mtu) {
1164 NL_SET_ERR_MSG_MOD(extack, "Peer MTU is too large to set XDP");
1165 err = -ERANGE;
1166 goto err;
1167 }
1168
1169 if (dev->real_num_rx_queues < peer->real_num_tx_queues) {
1170 NL_SET_ERR_MSG_MOD(extack, "XDP expects number of rx queues not less than peer tx queues");
1171 err = -ENOSPC;
1172 goto err;
1173 }
1174
1175 if (dev->flags & IFF_UP) {
1176 err = veth_enable_xdp(dev);
1177 if (err) {
1178 NL_SET_ERR_MSG_MOD(extack, "Setup for XDP failed");
1179 goto err;
1180 }
1181 }
1182
1183 if (!old_prog) {
1184 peer->hw_features &= ~NETIF_F_GSO_SOFTWARE;
1185 peer->max_mtu = max_mtu;
1186 }
1187 }
1188
1189 if (old_prog) {
1190 if (!prog) {
1191 if (dev->flags & IFF_UP)
1192 veth_disable_xdp(dev);
1193
1194 if (peer) {
1195 peer->hw_features |= NETIF_F_GSO_SOFTWARE;
1196 peer->max_mtu = ETH_MAX_MTU;
1197 }
1198 }
1199 bpf_prog_put(old_prog);
1200 }
1201
1202 if ((!!old_prog ^ !!prog) && peer)
1203 netdev_update_features(peer);
1204
1205 return 0;
1206 err:
1207 priv->_xdp_prog = old_prog;
1208
1209 return err;
1210 }
1211
1212 static int veth_xdp(struct net_device *dev, struct netdev_bpf *xdp)
1213 {
1214 switch (xdp->command) {
1215 case XDP_SETUP_PROG:
1216 return veth_xdp_set(dev, xdp->prog, xdp->extack);
1217 default:
1218 return -EINVAL;
1219 }
1220 }
1221
1222 static const struct net_device_ops veth_netdev_ops = {
1223 .ndo_init = veth_dev_init,
1224 .ndo_open = veth_open,
1225 .ndo_stop = veth_close,
1226 .ndo_start_xmit = veth_xmit,
1227 .ndo_get_stats64 = veth_get_stats64,
1228 .ndo_set_rx_mode = veth_set_multicast_list,
1229 .ndo_set_mac_address = eth_mac_addr,
1230 #ifdef CONFIG_NET_POLL_CONTROLLER
1231 .ndo_poll_controller = veth_poll_controller,
1232 #endif
1233 .ndo_get_iflink = veth_get_iflink,
1234 .ndo_fix_features = veth_fix_features,
1235 .ndo_features_check = passthru_features_check,
1236 .ndo_set_rx_headroom = veth_set_rx_headroom,
1237 .ndo_bpf = veth_xdp,
1238 .ndo_xdp_xmit = veth_ndo_xdp_xmit,
1239 .ndo_get_peer_dev = veth_peer_dev,
1240 };
1241
1242 #define VETH_FEATURES (NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HW_CSUM | \
1243 NETIF_F_RXCSUM | NETIF_F_SCTP_CRC | NETIF_F_HIGHDMA | \
1244 NETIF_F_GSO_SOFTWARE | NETIF_F_GSO_ENCAP_ALL | \
1245 NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_CTAG_RX | \
1246 NETIF_F_HW_VLAN_STAG_TX | NETIF_F_HW_VLAN_STAG_RX )
1247
1248 static void veth_setup(struct net_device *dev)
1249 {
1250 ether_setup(dev);
1251
1252 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1253 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1254 dev->priv_flags |= IFF_NO_QUEUE;
1255 dev->priv_flags |= IFF_PHONY_HEADROOM;
1256
1257 dev->netdev_ops = &veth_netdev_ops;
1258 dev->ethtool_ops = &veth_ethtool_ops;
1259 dev->features |= NETIF_F_LLTX;
1260 dev->features |= VETH_FEATURES;
1261 dev->vlan_features = dev->features &
1262 ~(NETIF_F_HW_VLAN_CTAG_TX |
1263 NETIF_F_HW_VLAN_STAG_TX |
1264 NETIF_F_HW_VLAN_CTAG_RX |
1265 NETIF_F_HW_VLAN_STAG_RX);
1266 dev->needs_free_netdev = true;
1267 dev->priv_destructor = veth_dev_free;
1268 dev->max_mtu = ETH_MAX_MTU;
1269
1270 dev->hw_features = VETH_FEATURES;
1271 dev->hw_enc_features = VETH_FEATURES;
1272 dev->mpls_features = NETIF_F_HW_CSUM | NETIF_F_GSO_SOFTWARE;
1273 }
1274
1275 /*
1276 * netlink interface
1277 */
1278
1279 static int veth_validate(struct nlattr *tb[], struct nlattr *data[],
1280 struct netlink_ext_ack *extack)
1281 {
1282 if (tb[IFLA_ADDRESS]) {
1283 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1284 return -EINVAL;
1285 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1286 return -EADDRNOTAVAIL;
1287 }
1288 if (tb[IFLA_MTU]) {
1289 if (!is_valid_veth_mtu(nla_get_u32(tb[IFLA_MTU])))
1290 return -EINVAL;
1291 }
1292 return 0;
1293 }
1294
1295 static struct rtnl_link_ops veth_link_ops;
1296
1297 static int veth_newlink(struct net *src_net, struct net_device *dev,
1298 struct nlattr *tb[], struct nlattr *data[],
1299 struct netlink_ext_ack *extack)
1300 {
1301 int err;
1302 struct net_device *peer;
1303 struct veth_priv *priv;
1304 char ifname[IFNAMSIZ];
1305 struct nlattr *peer_tb[IFLA_MAX + 1], **tbp;
1306 unsigned char name_assign_type;
1307 struct ifinfomsg *ifmp;
1308 struct net *net;
1309
1310 /*
1311 * create and register peer first
1312 */
1313 if (data != NULL && data[VETH_INFO_PEER] != NULL) {
1314 struct nlattr *nla_peer;
1315
1316 nla_peer = data[VETH_INFO_PEER];
1317 ifmp = nla_data(nla_peer);
1318 err = rtnl_nla_parse_ifla(peer_tb,
1319 nla_data(nla_peer) + sizeof(struct ifinfomsg),
1320 nla_len(nla_peer) - sizeof(struct ifinfomsg),
1321 NULL);
1322 if (err < 0)
1323 return err;
1324
1325 err = veth_validate(peer_tb, NULL, extack);
1326 if (err < 0)
1327 return err;
1328
1329 tbp = peer_tb;
1330 } else {
1331 ifmp = NULL;
1332 tbp = tb;
1333 }
1334
1335 if (ifmp && tbp[IFLA_IFNAME]) {
1336 nla_strscpy(ifname, tbp[IFLA_IFNAME], IFNAMSIZ);
1337 name_assign_type = NET_NAME_USER;
1338 } else {
1339 snprintf(ifname, IFNAMSIZ, DRV_NAME "%%d");
1340 name_assign_type = NET_NAME_ENUM;
1341 }
1342
1343 net = rtnl_link_get_net(src_net, tbp);
1344 if (IS_ERR(net))
1345 return PTR_ERR(net);
1346
1347 peer = rtnl_create_link(net, ifname, name_assign_type,
1348 &veth_link_ops, tbp, extack);
1349 if (IS_ERR(peer)) {
1350 put_net(net);
1351 return PTR_ERR(peer);
1352 }
1353
1354 if (!ifmp || !tbp[IFLA_ADDRESS])
1355 eth_hw_addr_random(peer);
1356
1357 if (ifmp && (dev->ifindex != 0))
1358 peer->ifindex = ifmp->ifi_index;
1359
1360 peer->gso_max_size = dev->gso_max_size;
1361 peer->gso_max_segs = dev->gso_max_segs;
1362
1363 err = register_netdevice(peer);
1364 put_net(net);
1365 net = NULL;
1366 if (err < 0)
1367 goto err_register_peer;
1368
1369 netif_carrier_off(peer);
1370
1371 err = rtnl_configure_link(peer, ifmp);
1372 if (err < 0)
1373 goto err_configure_peer;
1374
1375 /*
1376 * register dev last
1377 *
1378 * note, that since we've registered new device the dev's name
1379 * should be re-allocated
1380 */
1381
1382 if (tb[IFLA_ADDRESS] == NULL)
1383 eth_hw_addr_random(dev);
1384
1385 if (tb[IFLA_IFNAME])
1386 nla_strscpy(dev->name, tb[IFLA_IFNAME], IFNAMSIZ);
1387 else
1388 snprintf(dev->name, IFNAMSIZ, DRV_NAME "%%d");
1389
1390 err = register_netdevice(dev);
1391 if (err < 0)
1392 goto err_register_dev;
1393
1394 netif_carrier_off(dev);
1395
1396 /*
1397 * tie the deviced together
1398 */
1399
1400 priv = netdev_priv(dev);
1401 rcu_assign_pointer(priv->peer, peer);
1402
1403 priv = netdev_priv(peer);
1404 rcu_assign_pointer(priv->peer, dev);
1405
1406 return 0;
1407
1408 err_register_dev:
1409 /* nothing to do */
1410 err_configure_peer:
1411 unregister_netdevice(peer);
1412 return err;
1413
1414 err_register_peer:
1415 free_netdev(peer);
1416 return err;
1417 }
1418
1419 static void veth_dellink(struct net_device *dev, struct list_head *head)
1420 {
1421 struct veth_priv *priv;
1422 struct net_device *peer;
1423
1424 priv = netdev_priv(dev);
1425 peer = rtnl_dereference(priv->peer);
1426
1427 /* Note : dellink() is called from default_device_exit_batch(),
1428 * before a rcu_synchronize() point. The devices are guaranteed
1429 * not being freed before one RCU grace period.
1430 */
1431 RCU_INIT_POINTER(priv->peer, NULL);
1432 unregister_netdevice_queue(dev, head);
1433
1434 if (peer) {
1435 priv = netdev_priv(peer);
1436 RCU_INIT_POINTER(priv->peer, NULL);
1437 unregister_netdevice_queue(peer, head);
1438 }
1439 }
1440
1441 static const struct nla_policy veth_policy[VETH_INFO_MAX + 1] = {
1442 [VETH_INFO_PEER] = { .len = sizeof(struct ifinfomsg) },
1443 };
1444
1445 static struct net *veth_get_link_net(const struct net_device *dev)
1446 {
1447 struct veth_priv *priv = netdev_priv(dev);
1448 struct net_device *peer = rtnl_dereference(priv->peer);
1449
1450 return peer ? dev_net(peer) : dev_net(dev);
1451 }
1452
1453 static struct rtnl_link_ops veth_link_ops = {
1454 .kind = DRV_NAME,
1455 .priv_size = sizeof(struct veth_priv),
1456 .setup = veth_setup,
1457 .validate = veth_validate,
1458 .newlink = veth_newlink,
1459 .dellink = veth_dellink,
1460 .policy = veth_policy,
1461 .maxtype = VETH_INFO_MAX,
1462 .get_link_net = veth_get_link_net,
1463 };
1464
1465 /*
1466 * init/fini
1467 */
1468
1469 static __init int veth_init(void)
1470 {
1471 return rtnl_link_register(&veth_link_ops);
1472 }
1473
1474 static __exit void veth_exit(void)
1475 {
1476 rtnl_link_unregister(&veth_link_ops);
1477 }
1478
1479 module_init(veth_init);
1480 module_exit(veth_exit);
1481
1482 MODULE_DESCRIPTION("Virtual Ethernet Tunnel");
1483 MODULE_LICENSE("GPL v2");
1484 MODULE_ALIAS_RTNL_LINK(DRV_NAME);
Linux with added FPC-III support