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dmaengine: imx-sdma: Let the core do the device node validation
[linux/fpc-iii.git] / drivers / net / veth.c
blob09a1433b08332996163a5344d91f5de430890d2d
1 /*
2 * drivers/net/veth.c
3 *
4 * Copyright (C) 2007 OpenVZ http://openvz.org, SWsoft Inc
5 *
6 * Author: Pavel Emelianov <xemul@openvz.org>
7 * Ethtool interface from: Eric W. Biederman <ebiederm@xmission.com>
8 *
9 */
10
11 #include <linux/netdevice.h>
12 #include <linux/slab.h>
13 #include <linux/ethtool.h>
14 #include <linux/etherdevice.h>
15 #include <linux/u64_stats_sync.h>
16
17 #include <net/rtnetlink.h>
18 #include <net/dst.h>
19 #include <net/xfrm.h>
20 #include <net/xdp.h>
21 #include <linux/veth.h>
22 #include <linux/module.h>
23 #include <linux/bpf.h>
24 #include <linux/filter.h>
25 #include <linux/ptr_ring.h>
26 #include <linux/bpf_trace.h>
27 #include <linux/net_tstamp.h>
28
29 #define DRV_NAME "veth"
30 #define DRV_VERSION "1.0"
31
32 #define VETH_XDP_FLAG BIT(0)
33 #define VETH_RING_SIZE 256
34 #define VETH_XDP_HEADROOM (XDP_PACKET_HEADROOM + NET_IP_ALIGN)
35
36 /* Separating two types of XDP xmit */
37 #define VETH_XDP_TX BIT(0)
38 #define VETH_XDP_REDIR BIT(1)
39
40 struct veth_rq_stats {
41 u64 xdp_packets;
42 u64 xdp_bytes;
43 u64 xdp_drops;
44 struct u64_stats_sync syncp;
45 };
46
47 struct veth_rq {
48 struct napi_struct xdp_napi;
49 struct net_device *dev;
50 struct bpf_prog __rcu *xdp_prog;
51 struct xdp_mem_info xdp_mem;
52 struct veth_rq_stats stats;
53 bool rx_notify_masked;
54 struct ptr_ring xdp_ring;
55 struct xdp_rxq_info xdp_rxq;
56 };
57
58 struct veth_priv {
59 struct net_device __rcu *peer;
60 atomic64_t dropped;
61 struct bpf_prog *_xdp_prog;
62 struct veth_rq *rq;
63 unsigned int requested_headroom;
64 };
65
66 /*
67 * ethtool interface
68 */
69
70 struct veth_q_stat_desc {
71 char desc[ETH_GSTRING_LEN];
72 size_t offset;
73 };
74
75 #define VETH_RQ_STAT(m) offsetof(struct veth_rq_stats, m)
76
77 static const struct veth_q_stat_desc veth_rq_stats_desc[] = {
78 { "xdp_packets", VETH_RQ_STAT(xdp_packets) },
79 { "xdp_bytes", VETH_RQ_STAT(xdp_bytes) },
80 { "xdp_drops", VETH_RQ_STAT(xdp_drops) },
81 };
82
83 #define VETH_RQ_STATS_LEN ARRAY_SIZE(veth_rq_stats_desc)
84
85 static struct {
86 const char string[ETH_GSTRING_LEN];
87 } ethtool_stats_keys[] = {
88 { "peer_ifindex" },
89 };
90
91 static int veth_get_link_ksettings(struct net_device *dev,
92 struct ethtool_link_ksettings *cmd)
93 {
94 cmd->base.speed = SPEED_10000;
95 cmd->base.duplex = DUPLEX_FULL;
96 cmd->base.port = PORT_TP;
97 cmd->base.autoneg = AUTONEG_DISABLE;
98 return 0;
99 }
100
101 static void veth_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
102 {
103 strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
104 strlcpy(info->version, DRV_VERSION, sizeof(info->version));
105 }
106
107 static void veth_get_strings(struct net_device *dev, u32 stringset, u8 *buf)
108 {
109 char *p = (char *)buf;
110 int i, j;
111
112 switch(stringset) {
113 case ETH_SS_STATS:
114 memcpy(p, &ethtool_stats_keys, sizeof(ethtool_stats_keys));
115 p += sizeof(ethtool_stats_keys);
116 for (i = 0; i < dev->real_num_rx_queues; i++) {
117 for (j = 0; j < VETH_RQ_STATS_LEN; j++) {
118 snprintf(p, ETH_GSTRING_LEN,
119 "rx_queue_%u_%.11s",
120 i, veth_rq_stats_desc[j].desc);
121 p += ETH_GSTRING_LEN;
122 }
123 }
124 break;
125 }
126 }
127
128 static int veth_get_sset_count(struct net_device *dev, int sset)
129 {
130 switch (sset) {
131 case ETH_SS_STATS:
132 return ARRAY_SIZE(ethtool_stats_keys) +
133 VETH_RQ_STATS_LEN * dev->real_num_rx_queues;
134 default:
135 return -EOPNOTSUPP;
136 }
137 }
138
139 static void veth_get_ethtool_stats(struct net_device *dev,
140 struct ethtool_stats *stats, u64 *data)
141 {
142 struct veth_priv *priv = netdev_priv(dev);
143 struct net_device *peer = rtnl_dereference(priv->peer);
144 int i, j, idx;
145
146 data[0] = peer ? peer->ifindex : 0;
147 idx = 1;
148 for (i = 0; i < dev->real_num_rx_queues; i++) {
149 const struct veth_rq_stats *rq_stats = &priv->rq[i].stats;
150 const void *stats_base = (void *)rq_stats;
151 unsigned int start;
152 size_t offset;
153
154 do {
155 start = u64_stats_fetch_begin_irq(&rq_stats->syncp);
156 for (j = 0; j < VETH_RQ_STATS_LEN; j++) {
157 offset = veth_rq_stats_desc[j].offset;
158 data[idx + j] = *(u64 *)(stats_base + offset);
159 }
160 } while (u64_stats_fetch_retry_irq(&rq_stats->syncp, start));
161 idx += VETH_RQ_STATS_LEN;
162 }
163 }
164
165 static const struct ethtool_ops veth_ethtool_ops = {
166 .get_drvinfo = veth_get_drvinfo,
167 .get_link = ethtool_op_get_link,
168 .get_strings = veth_get_strings,
169 .get_sset_count = veth_get_sset_count,
170 .get_ethtool_stats = veth_get_ethtool_stats,
171 .get_link_ksettings = veth_get_link_ksettings,
172 .get_ts_info = ethtool_op_get_ts_info,
173 };
174
175 /* general routines */
176
177 static bool veth_is_xdp_frame(void *ptr)
178 {
179 return (unsigned long)ptr & VETH_XDP_FLAG;
180 }
181
182 static void *veth_ptr_to_xdp(void *ptr)
183 {
184 return (void *)((unsigned long)ptr & ~VETH_XDP_FLAG);
185 }
186
187 static void *veth_xdp_to_ptr(void *ptr)
188 {
189 return (void *)((unsigned long)ptr | VETH_XDP_FLAG);
190 }
191
192 static void veth_ptr_free(void *ptr)
193 {
194 if (veth_is_xdp_frame(ptr))
195 xdp_return_frame(veth_ptr_to_xdp(ptr));
196 else
197 kfree_skb(ptr);
198 }
199
200 static void __veth_xdp_flush(struct veth_rq *rq)
201 {
202 /* Write ptr_ring before reading rx_notify_masked */
203 smp_mb();
204 if (!rq->rx_notify_masked) {
205 rq->rx_notify_masked = true;
206 napi_schedule(&rq->xdp_napi);
207 }
208 }
209
210 static int veth_xdp_rx(struct veth_rq *rq, struct sk_buff *skb)
211 {
212 if (unlikely(ptr_ring_produce(&rq->xdp_ring, skb))) {
213 dev_kfree_skb_any(skb);
214 return NET_RX_DROP;
215 }
216
217 return NET_RX_SUCCESS;
218 }
219
220 static int veth_forward_skb(struct net_device *dev, struct sk_buff *skb,
221 struct veth_rq *rq, bool xdp)
222 {
223 return __dev_forward_skb(dev, skb) ?: xdp ?
224 veth_xdp_rx(rq, skb) :
225 netif_rx(skb);
226 }
227
228 static netdev_tx_t veth_xmit(struct sk_buff *skb, struct net_device *dev)
229 {
230 struct veth_priv *rcv_priv, *priv = netdev_priv(dev);
231 struct veth_rq *rq = NULL;
232 struct net_device *rcv;
233 int length = skb->len;
234 bool rcv_xdp = false;
235 int rxq;
236
237 rcu_read_lock();
238 rcv = rcu_dereference(priv->peer);
239 if (unlikely(!rcv)) {
240 kfree_skb(skb);
241 goto drop;
242 }
243
244 rcv_priv = netdev_priv(rcv);
245 rxq = skb_get_queue_mapping(skb);
246 if (rxq < rcv->real_num_rx_queues) {
247 rq = &rcv_priv->rq[rxq];
248 rcv_xdp = rcu_access_pointer(rq->xdp_prog);
249 if (rcv_xdp)
250 skb_record_rx_queue(skb, rxq);
251 }
252
253 skb_tx_timestamp(skb);
254 if (likely(veth_forward_skb(rcv, skb, rq, rcv_xdp) == NET_RX_SUCCESS)) {
255 if (!rcv_xdp) {
256 struct pcpu_lstats *stats = this_cpu_ptr(dev->lstats);
257
258 u64_stats_update_begin(&stats->syncp);
259 stats->bytes += length;
260 stats->packets++;
261 u64_stats_update_end(&stats->syncp);
262 }
263 } else {
264 drop:
265 atomic64_inc(&priv->dropped);
266 }
267
268 if (rcv_xdp)
269 __veth_xdp_flush(rq);
270
271 rcu_read_unlock();
272
273 return NETDEV_TX_OK;
274 }
275
276 static u64 veth_stats_tx(struct pcpu_lstats *result, struct net_device *dev)
277 {
278 struct veth_priv *priv = netdev_priv(dev);
279 int cpu;
280
281 result->packets = 0;
282 result->bytes = 0;
283 for_each_possible_cpu(cpu) {
284 struct pcpu_lstats *stats = per_cpu_ptr(dev->lstats, cpu);
285 u64 packets, bytes;
286 unsigned int start;
287
288 do {
289 start = u64_stats_fetch_begin_irq(&stats->syncp);
290 packets = stats->packets;
291 bytes = stats->bytes;
292 } while (u64_stats_fetch_retry_irq(&stats->syncp, start));
293 result->packets += packets;
294 result->bytes += bytes;
295 }
296 return atomic64_read(&priv->dropped);
297 }
298
299 static void veth_stats_rx(struct veth_rq_stats *result, struct net_device *dev)
300 {
301 struct veth_priv *priv = netdev_priv(dev);
302 int i;
303
304 result->xdp_packets = 0;
305 result->xdp_bytes = 0;
306 result->xdp_drops = 0;
307 for (i = 0; i < dev->num_rx_queues; i++) {
308 struct veth_rq_stats *stats = &priv->rq[i].stats;
309 u64 packets, bytes, drops;
310 unsigned int start;
311
312 do {
313 start = u64_stats_fetch_begin_irq(&stats->syncp);
314 packets = stats->xdp_packets;
315 bytes = stats->xdp_bytes;
316 drops = stats->xdp_drops;
317 } while (u64_stats_fetch_retry_irq(&stats->syncp, start));
318 result->xdp_packets += packets;
319 result->xdp_bytes += bytes;
320 result->xdp_drops += drops;
321 }
322 }
323
324 static void veth_get_stats64(struct net_device *dev,
325 struct rtnl_link_stats64 *tot)
326 {
327 struct veth_priv *priv = netdev_priv(dev);
328 struct net_device *peer;
329 struct veth_rq_stats rx;
330 struct pcpu_lstats tx;
331
332 tot->tx_dropped = veth_stats_tx(&tx, dev);
333 tot->tx_bytes = tx.bytes;
334 tot->tx_packets = tx.packets;
335
336 veth_stats_rx(&rx, dev);
337 tot->rx_dropped = rx.xdp_drops;
338 tot->rx_bytes = rx.xdp_bytes;
339 tot->rx_packets = rx.xdp_packets;
340
341 rcu_read_lock();
342 peer = rcu_dereference(priv->peer);
343 if (peer) {
344 tot->rx_dropped += veth_stats_tx(&tx, peer);
345 tot->rx_bytes += tx.bytes;
346 tot->rx_packets += tx.packets;
347
348 veth_stats_rx(&rx, peer);
349 tot->tx_bytes += rx.xdp_bytes;
350 tot->tx_packets += rx.xdp_packets;
351 }
352 rcu_read_unlock();
353 }
354
355 /* fake multicast ability */
356 static void veth_set_multicast_list(struct net_device *dev)
357 {
358 }
359
360 static struct sk_buff *veth_build_skb(void *head, int headroom, int len,
361 int buflen)
362 {
363 struct sk_buff *skb;
364
365 if (!buflen) {
366 buflen = SKB_DATA_ALIGN(headroom + len) +
367 SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
368 }
369 skb = build_skb(head, buflen);
370 if (!skb)
371 return NULL;
372
373 skb_reserve(skb, headroom);
374 skb_put(skb, len);
375
376 return skb;
377 }
378
379 static int veth_select_rxq(struct net_device *dev)
380 {
381 return smp_processor_id() % dev->real_num_rx_queues;
382 }
383
384 static int veth_xdp_xmit(struct net_device *dev, int n,
385 struct xdp_frame **frames, u32 flags)
386 {
387 struct veth_priv *rcv_priv, *priv = netdev_priv(dev);
388 struct net_device *rcv;
389 int i, ret, drops = n;
390 unsigned int max_len;
391 struct veth_rq *rq;
392
393 if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK)) {
394 ret = -EINVAL;
395 goto drop;
396 }
397
398 rcv = rcu_dereference(priv->peer);
399 if (unlikely(!rcv)) {
400 ret = -ENXIO;
401 goto drop;
402 }
403
404 rcv_priv = netdev_priv(rcv);
405 rq = &rcv_priv->rq[veth_select_rxq(rcv)];
406 /* Non-NULL xdp_prog ensures that xdp_ring is initialized on receive
407 * side. This means an XDP program is loaded on the peer and the peer
408 * device is up.
409 */
410 if (!rcu_access_pointer(rq->xdp_prog)) {
411 ret = -ENXIO;
412 goto drop;
413 }
414
415 drops = 0;
416 max_len = rcv->mtu + rcv->hard_header_len + VLAN_HLEN;
417
418 spin_lock(&rq->xdp_ring.producer_lock);
419 for (i = 0; i < n; i++) {
420 struct xdp_frame *frame = frames[i];
421 void *ptr = veth_xdp_to_ptr(frame);
422
423 if (unlikely(frame->len > max_len ||
424 __ptr_ring_produce(&rq->xdp_ring, ptr))) {
425 xdp_return_frame_rx_napi(frame);
426 drops++;
427 }
428 }
429 spin_unlock(&rq->xdp_ring.producer_lock);
430
431 if (flags & XDP_XMIT_FLUSH)
432 __veth_xdp_flush(rq);
433
434 if (likely(!drops))
435 return n;
436
437 ret = n - drops;
438 drop:
439 atomic64_add(drops, &priv->dropped);
440
441 return ret;
442 }
443
444 static void veth_xdp_flush(struct net_device *dev)
445 {
446 struct veth_priv *rcv_priv, *priv = netdev_priv(dev);
447 struct net_device *rcv;
448 struct veth_rq *rq;
449
450 rcu_read_lock();
451 rcv = rcu_dereference(priv->peer);
452 if (unlikely(!rcv))
453 goto out;
454
455 rcv_priv = netdev_priv(rcv);
456 rq = &rcv_priv->rq[veth_select_rxq(rcv)];
457 /* xdp_ring is initialized on receive side? */
458 if (unlikely(!rcu_access_pointer(rq->xdp_prog)))
459 goto out;
460
461 __veth_xdp_flush(rq);
462 out:
463 rcu_read_unlock();
464 }
465
466 static int veth_xdp_tx(struct net_device *dev, struct xdp_buff *xdp)
467 {
468 struct xdp_frame *frame = convert_to_xdp_frame(xdp);
469
470 if (unlikely(!frame))
471 return -EOVERFLOW;
472
473 return veth_xdp_xmit(dev, 1, &frame, 0);
474 }
475
476 static struct sk_buff *veth_xdp_rcv_one(struct veth_rq *rq,
477 struct xdp_frame *frame,
478 unsigned int *xdp_xmit)
479 {
480 void *hard_start = frame->data - frame->headroom;
481 void *head = hard_start - sizeof(struct xdp_frame);
482 int len = frame->len, delta = 0;
483 struct xdp_frame orig_frame;
484 struct bpf_prog *xdp_prog;
485 unsigned int headroom;
486 struct sk_buff *skb;
487
488 rcu_read_lock();
489 xdp_prog = rcu_dereference(rq->xdp_prog);
490 if (likely(xdp_prog)) {
491 struct xdp_buff xdp;
492 u32 act;
493
494 xdp.data_hard_start = hard_start;
495 xdp.data = frame->data;
496 xdp.data_end = frame->data + frame->len;
497 xdp.data_meta = frame->data - frame->metasize;
498 xdp.rxq = &rq->xdp_rxq;
499
500 act = bpf_prog_run_xdp(xdp_prog, &xdp);
501
502 switch (act) {
503 case XDP_PASS:
504 delta = frame->data - xdp.data;
505 len = xdp.data_end - xdp.data;
506 break;
507 case XDP_TX:
508 orig_frame = *frame;
509 xdp.data_hard_start = head;
510 xdp.rxq->mem = frame->mem;
511 if (unlikely(veth_xdp_tx(rq->dev, &xdp) < 0)) {
512 trace_xdp_exception(rq->dev, xdp_prog, act);
513 frame = &orig_frame;
514 goto err_xdp;
515 }
516 *xdp_xmit |= VETH_XDP_TX;
517 rcu_read_unlock();
518 goto xdp_xmit;
519 case XDP_REDIRECT:
520 orig_frame = *frame;
521 xdp.data_hard_start = head;
522 xdp.rxq->mem = frame->mem;
523 if (xdp_do_redirect(rq->dev, &xdp, xdp_prog)) {
524 frame = &orig_frame;
525 goto err_xdp;
526 }
527 *xdp_xmit |= VETH_XDP_REDIR;
528 rcu_read_unlock();
529 goto xdp_xmit;
530 default:
531 bpf_warn_invalid_xdp_action(act);
532 /* fall through */
533 case XDP_ABORTED:
534 trace_xdp_exception(rq->dev, xdp_prog, act);
535 /* fall through */
536 case XDP_DROP:
537 goto err_xdp;
538 }
539 }
540 rcu_read_unlock();
541
542 headroom = sizeof(struct xdp_frame) + frame->headroom - delta;
543 skb = veth_build_skb(head, headroom, len, 0);
544 if (!skb) {
545 xdp_return_frame(frame);
546 goto err;
547 }
548
549 xdp_scrub_frame(frame);
550 skb->protocol = eth_type_trans(skb, rq->dev);
551 err:
552 return skb;
553 err_xdp:
554 rcu_read_unlock();
555 xdp_return_frame(frame);
556 xdp_xmit:
557 return NULL;
558 }
559
560 static struct sk_buff *veth_xdp_rcv_skb(struct veth_rq *rq, struct sk_buff *skb,
561 unsigned int *xdp_xmit)
562 {
563 u32 pktlen, headroom, act, metalen;
564 void *orig_data, *orig_data_end;
565 struct bpf_prog *xdp_prog;
566 int mac_len, delta, off;
567 struct xdp_buff xdp;
568
569 skb_orphan(skb);
570
571 rcu_read_lock();
572 xdp_prog = rcu_dereference(rq->xdp_prog);
573 if (unlikely(!xdp_prog)) {
574 rcu_read_unlock();
575 goto out;
576 }
577
578 mac_len = skb->data - skb_mac_header(skb);
579 pktlen = skb->len + mac_len;
580 headroom = skb_headroom(skb) - mac_len;
581
582 if (skb_shared(skb) || skb_head_is_locked(skb) ||
583 skb_is_nonlinear(skb) || headroom < XDP_PACKET_HEADROOM) {
584 struct sk_buff *nskb;
585 int size, head_off;
586 void *head, *start;
587 struct page *page;
588
589 size = SKB_DATA_ALIGN(VETH_XDP_HEADROOM + pktlen) +
590 SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
591 if (size > PAGE_SIZE)
592 goto drop;
593
594 page = alloc_page(GFP_ATOMIC | __GFP_NOWARN);
595 if (!page)
596 goto drop;
597
598 head = page_address(page);
599 start = head + VETH_XDP_HEADROOM;
600 if (skb_copy_bits(skb, -mac_len, start, pktlen)) {
601 page_frag_free(head);
602 goto drop;
603 }
604
605 nskb = veth_build_skb(head,
606 VETH_XDP_HEADROOM + mac_len, skb->len,
607 PAGE_SIZE);
608 if (!nskb) {
609 page_frag_free(head);
610 goto drop;
611 }
612
613 skb_copy_header(nskb, skb);
614 head_off = skb_headroom(nskb) - skb_headroom(skb);
615 skb_headers_offset_update(nskb, head_off);
616 consume_skb(skb);
617 skb = nskb;
618 }
619
620 xdp.data_hard_start = skb->head;
621 xdp.data = skb_mac_header(skb);
622 xdp.data_end = xdp.data + pktlen;
623 xdp.data_meta = xdp.data;
624 xdp.rxq = &rq->xdp_rxq;
625 orig_data = xdp.data;
626 orig_data_end = xdp.data_end;
627
628 act = bpf_prog_run_xdp(xdp_prog, &xdp);
629
630 switch (act) {
631 case XDP_PASS:
632 break;
633 case XDP_TX:
634 get_page(virt_to_page(xdp.data));
635 consume_skb(skb);
636 xdp.rxq->mem = rq->xdp_mem;
637 if (unlikely(veth_xdp_tx(rq->dev, &xdp) < 0)) {
638 trace_xdp_exception(rq->dev, xdp_prog, act);
639 goto err_xdp;
640 }
641 *xdp_xmit |= VETH_XDP_TX;
642 rcu_read_unlock();
643 goto xdp_xmit;
644 case XDP_REDIRECT:
645 get_page(virt_to_page(xdp.data));
646 consume_skb(skb);
647 xdp.rxq->mem = rq->xdp_mem;
648 if (xdp_do_redirect(rq->dev, &xdp, xdp_prog))
649 goto err_xdp;
650 *xdp_xmit |= VETH_XDP_REDIR;
651 rcu_read_unlock();
652 goto xdp_xmit;
653 default:
654 bpf_warn_invalid_xdp_action(act);
655 /* fall through */
656 case XDP_ABORTED:
657 trace_xdp_exception(rq->dev, xdp_prog, act);
658 /* fall through */
659 case XDP_DROP:
660 goto drop;
661 }
662 rcu_read_unlock();
663
664 delta = orig_data - xdp.data;
665 off = mac_len + delta;
666 if (off > 0)
667 __skb_push(skb, off);
668 else if (off < 0)
669 __skb_pull(skb, -off);
670 skb->mac_header -= delta;
671 off = xdp.data_end - orig_data_end;
672 if (off != 0)
673 __skb_put(skb, off);
674 skb->protocol = eth_type_trans(skb, rq->dev);
675
676 metalen = xdp.data - xdp.data_meta;
677 if (metalen)
678 skb_metadata_set(skb, metalen);
679 out:
680 return skb;
681 drop:
682 rcu_read_unlock();
683 kfree_skb(skb);
684 return NULL;
685 err_xdp:
686 rcu_read_unlock();
687 page_frag_free(xdp.data);
688 xdp_xmit:
689 return NULL;
690 }
691
692 static int veth_xdp_rcv(struct veth_rq *rq, int budget, unsigned int *xdp_xmit)
693 {
694 int i, done = 0, drops = 0, bytes = 0;
695
696 for (i = 0; i < budget; i++) {
697 void *ptr = __ptr_ring_consume(&rq->xdp_ring);
698 unsigned int xdp_xmit_one = 0;
699 struct sk_buff *skb;
700
701 if (!ptr)
702 break;
703
704 if (veth_is_xdp_frame(ptr)) {
705 struct xdp_frame *frame = veth_ptr_to_xdp(ptr);
706
707 bytes += frame->len;
708 skb = veth_xdp_rcv_one(rq, frame, &xdp_xmit_one);
709 } else {
710 skb = ptr;
711 bytes += skb->len;
712 skb = veth_xdp_rcv_skb(rq, skb, &xdp_xmit_one);
713 }
714 *xdp_xmit |= xdp_xmit_one;
715
716 if (skb)
717 napi_gro_receive(&rq->xdp_napi, skb);
718 else if (!xdp_xmit_one)
719 drops++;
720
721 done++;
722 }
723
724 u64_stats_update_begin(&rq->stats.syncp);
725 rq->stats.xdp_packets += done;
726 rq->stats.xdp_bytes += bytes;
727 rq->stats.xdp_drops += drops;
728 u64_stats_update_end(&rq->stats.syncp);
729
730 return done;
731 }
732
733 static int veth_poll(struct napi_struct *napi, int budget)
734 {
735 struct veth_rq *rq =
736 container_of(napi, struct veth_rq, xdp_napi);
737 unsigned int xdp_xmit = 0;
738 int done;
739
740 xdp_set_return_frame_no_direct();
741 done = veth_xdp_rcv(rq, budget, &xdp_xmit);
742
743 if (done < budget && napi_complete_done(napi, done)) {
744 /* Write rx_notify_masked before reading ptr_ring */
745 smp_store_mb(rq->rx_notify_masked, false);
746 if (unlikely(!__ptr_ring_empty(&rq->xdp_ring))) {
747 rq->rx_notify_masked = true;
748 napi_schedule(&rq->xdp_napi);
749 }
750 }
751
752 if (xdp_xmit & VETH_XDP_TX)
753 veth_xdp_flush(rq->dev);
754 if (xdp_xmit & VETH_XDP_REDIR)
755 xdp_do_flush_map();
756 xdp_clear_return_frame_no_direct();
757
758 return done;
759 }
760
761 static int veth_napi_add(struct net_device *dev)
762 {
763 struct veth_priv *priv = netdev_priv(dev);
764 int err, i;
765
766 for (i = 0; i < dev->real_num_rx_queues; i++) {
767 struct veth_rq *rq = &priv->rq[i];
768
769 err = ptr_ring_init(&rq->xdp_ring, VETH_RING_SIZE, GFP_KERNEL);
770 if (err)
771 goto err_xdp_ring;
772 }
773
774 for (i = 0; i < dev->real_num_rx_queues; i++) {
775 struct veth_rq *rq = &priv->rq[i];
776
777 netif_napi_add(dev, &rq->xdp_napi, veth_poll, NAPI_POLL_WEIGHT);
778 napi_enable(&rq->xdp_napi);
779 }
780
781 return 0;
782 err_xdp_ring:
783 for (i--; i >= 0; i--)
784 ptr_ring_cleanup(&priv->rq[i].xdp_ring, veth_ptr_free);
785
786 return err;
787 }
788
789 static void veth_napi_del(struct net_device *dev)
790 {
791 struct veth_priv *priv = netdev_priv(dev);
792 int i;
793
794 for (i = 0; i < dev->real_num_rx_queues; i++) {
795 struct veth_rq *rq = &priv->rq[i];
796
797 napi_disable(&rq->xdp_napi);
798 napi_hash_del(&rq->xdp_napi);
799 }
800 synchronize_net();
801
802 for (i = 0; i < dev->real_num_rx_queues; i++) {
803 struct veth_rq *rq = &priv->rq[i];
804
805 netif_napi_del(&rq->xdp_napi);
806 rq->rx_notify_masked = false;
807 ptr_ring_cleanup(&rq->xdp_ring, veth_ptr_free);
808 }
809 }
810
811 static int veth_enable_xdp(struct net_device *dev)
812 {
813 struct veth_priv *priv = netdev_priv(dev);
814 int err, i;
815
816 if (!xdp_rxq_info_is_reg(&priv->rq[0].xdp_rxq)) {
817 for (i = 0; i < dev->real_num_rx_queues; i++) {
818 struct veth_rq *rq = &priv->rq[i];
819
820 err = xdp_rxq_info_reg(&rq->xdp_rxq, dev, i);
821 if (err < 0)
822 goto err_rxq_reg;
823
824 err = xdp_rxq_info_reg_mem_model(&rq->xdp_rxq,
825 MEM_TYPE_PAGE_SHARED,
826 NULL);
827 if (err < 0)
828 goto err_reg_mem;
829
830 /* Save original mem info as it can be overwritten */
831 rq->xdp_mem = rq->xdp_rxq.mem;
832 }
833
834 err = veth_napi_add(dev);
835 if (err)
836 goto err_rxq_reg;
837 }
838
839 for (i = 0; i < dev->real_num_rx_queues; i++)
840 rcu_assign_pointer(priv->rq[i].xdp_prog, priv->_xdp_prog);
841
842 return 0;
843 err_reg_mem:
844 xdp_rxq_info_unreg(&priv->rq[i].xdp_rxq);
845 err_rxq_reg:
846 for (i--; i >= 0; i--)
847 xdp_rxq_info_unreg(&priv->rq[i].xdp_rxq);
848
849 return err;
850 }
851
852 static void veth_disable_xdp(struct net_device *dev)
853 {
854 struct veth_priv *priv = netdev_priv(dev);
855 int i;
856
857 for (i = 0; i < dev->real_num_rx_queues; i++)
858 rcu_assign_pointer(priv->rq[i].xdp_prog, NULL);
859 veth_napi_del(dev);
860 for (i = 0; i < dev->real_num_rx_queues; i++) {
861 struct veth_rq *rq = &priv->rq[i];
862
863 rq->xdp_rxq.mem = rq->xdp_mem;
864 xdp_rxq_info_unreg(&rq->xdp_rxq);
865 }
866 }
867
868 static int veth_open(struct net_device *dev)
869 {
870 struct veth_priv *priv = netdev_priv(dev);
871 struct net_device *peer = rtnl_dereference(priv->peer);
872 int err;
873
874 if (!peer)
875 return -ENOTCONN;
876
877 if (priv->_xdp_prog) {
878 err = veth_enable_xdp(dev);
879 if (err)
880 return err;
881 }
882
883 if (peer->flags & IFF_UP) {
884 netif_carrier_on(dev);
885 netif_carrier_on(peer);
886 }
887
888 return 0;
889 }
890
891 static int veth_close(struct net_device *dev)
892 {
893 struct veth_priv *priv = netdev_priv(dev);
894 struct net_device *peer = rtnl_dereference(priv->peer);
895
896 netif_carrier_off(dev);
897 if (peer)
898 netif_carrier_off(peer);
899
900 if (priv->_xdp_prog)
901 veth_disable_xdp(dev);
902
903 return 0;
904 }
905
906 static int is_valid_veth_mtu(int mtu)
907 {
908 return mtu >= ETH_MIN_MTU && mtu <= ETH_MAX_MTU;
909 }
910
911 static int veth_alloc_queues(struct net_device *dev)
912 {
913 struct veth_priv *priv = netdev_priv(dev);
914 int i;
915
916 priv->rq = kcalloc(dev->num_rx_queues, sizeof(*priv->rq), GFP_KERNEL);
917 if (!priv->rq)
918 return -ENOMEM;
919
920 for (i = 0; i < dev->num_rx_queues; i++) {
921 priv->rq[i].dev = dev;
922 u64_stats_init(&priv->rq[i].stats.syncp);
923 }
924
925 return 0;
926 }
927
928 static void veth_free_queues(struct net_device *dev)
929 {
930 struct veth_priv *priv = netdev_priv(dev);
931
932 kfree(priv->rq);
933 }
934
935 static int veth_dev_init(struct net_device *dev)
936 {
937 int err;
938
939 dev->lstats = netdev_alloc_pcpu_stats(struct pcpu_lstats);
940 if (!dev->lstats)
941 return -ENOMEM;
942
943 err = veth_alloc_queues(dev);
944 if (err) {
945 free_percpu(dev->lstats);
946 return err;
947 }
948
949 return 0;
950 }
951
952 static void veth_dev_free(struct net_device *dev)
953 {
954 veth_free_queues(dev);
955 free_percpu(dev->lstats);
956 }
957
958 #ifdef CONFIG_NET_POLL_CONTROLLER
959 static void veth_poll_controller(struct net_device *dev)
960 {
961 /* veth only receives frames when its peer sends one
962 * Since it has nothing to do with disabling irqs, we are guaranteed
963 * never to have pending data when we poll for it so
964 * there is nothing to do here.
965 *
966 * We need this though so netpoll recognizes us as an interface that
967 * supports polling, which enables bridge devices in virt setups to
968 * still use netconsole
969 */
970 }
971 #endif /* CONFIG_NET_POLL_CONTROLLER */
972
973 static int veth_get_iflink(const struct net_device *dev)
974 {
975 struct veth_priv *priv = netdev_priv(dev);
976 struct net_device *peer;
977 int iflink;
978
979 rcu_read_lock();
980 peer = rcu_dereference(priv->peer);
981 iflink = peer ? peer->ifindex : 0;
982 rcu_read_unlock();
983
984 return iflink;
985 }
986
987 static netdev_features_t veth_fix_features(struct net_device *dev,
988 netdev_features_t features)
989 {
990 struct veth_priv *priv = netdev_priv(dev);
991 struct net_device *peer;
992
993 peer = rtnl_dereference(priv->peer);
994 if (peer) {
995 struct veth_priv *peer_priv = netdev_priv(peer);
996
997 if (peer_priv->_xdp_prog)
998 features &= ~NETIF_F_GSO_SOFTWARE;
999 }
1000
1001 return features;
1002 }
1003
1004 static void veth_set_rx_headroom(struct net_device *dev, int new_hr)
1005 {
1006 struct veth_priv *peer_priv, *priv = netdev_priv(dev);
1007 struct net_device *peer;
1008
1009 if (new_hr < 0)
1010 new_hr = 0;
1011
1012 rcu_read_lock();
1013 peer = rcu_dereference(priv->peer);
1014 if (unlikely(!peer))
1015 goto out;
1016
1017 peer_priv = netdev_priv(peer);
1018 priv->requested_headroom = new_hr;
1019 new_hr = max(priv->requested_headroom, peer_priv->requested_headroom);
1020 dev->needed_headroom = new_hr;
1021 peer->needed_headroom = new_hr;
1022
1023 out:
1024 rcu_read_unlock();
1025 }
1026
1027 static int veth_xdp_set(struct net_device *dev, struct bpf_prog *prog,
1028 struct netlink_ext_ack *extack)
1029 {
1030 struct veth_priv *priv = netdev_priv(dev);
1031 struct bpf_prog *old_prog;
1032 struct net_device *peer;
1033 unsigned int max_mtu;
1034 int err;
1035
1036 old_prog = priv->_xdp_prog;
1037 priv->_xdp_prog = prog;
1038 peer = rtnl_dereference(priv->peer);
1039
1040 if (prog) {
1041 if (!peer) {
1042 NL_SET_ERR_MSG_MOD(extack, "Cannot set XDP when peer is detached");
1043 err = -ENOTCONN;
1044 goto err;
1045 }
1046
1047 max_mtu = PAGE_SIZE - VETH_XDP_HEADROOM -
1048 peer->hard_header_len -
1049 SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
1050 if (peer->mtu > max_mtu) {
1051 NL_SET_ERR_MSG_MOD(extack, "Peer MTU is too large to set XDP");
1052 err = -ERANGE;
1053 goto err;
1054 }
1055
1056 if (dev->real_num_rx_queues < peer->real_num_tx_queues) {
1057 NL_SET_ERR_MSG_MOD(extack, "XDP expects number of rx queues not less than peer tx queues");
1058 err = -ENOSPC;
1059 goto err;
1060 }
1061
1062 if (dev->flags & IFF_UP) {
1063 err = veth_enable_xdp(dev);
1064 if (err) {
1065 NL_SET_ERR_MSG_MOD(extack, "Setup for XDP failed");
1066 goto err;
1067 }
1068 }
1069
1070 if (!old_prog) {
1071 peer->hw_features &= ~NETIF_F_GSO_SOFTWARE;
1072 peer->max_mtu = max_mtu;
1073 }
1074 }
1075
1076 if (old_prog) {
1077 if (!prog) {
1078 if (dev->flags & IFF_UP)
1079 veth_disable_xdp(dev);
1080
1081 if (peer) {
1082 peer->hw_features |= NETIF_F_GSO_SOFTWARE;
1083 peer->max_mtu = ETH_MAX_MTU;
1084 }
1085 }
1086 bpf_prog_put(old_prog);
1087 }
1088
1089 if ((!!old_prog ^ !!prog) && peer)
1090 netdev_update_features(peer);
1091
1092 return 0;
1093 err:
1094 priv->_xdp_prog = old_prog;
1095
1096 return err;
1097 }
1098
1099 static u32 veth_xdp_query(struct net_device *dev)
1100 {
1101 struct veth_priv *priv = netdev_priv(dev);
1102 const struct bpf_prog *xdp_prog;
1103
1104 xdp_prog = priv->_xdp_prog;
1105 if (xdp_prog)
1106 return xdp_prog->aux->id;
1107
1108 return 0;
1109 }
1110
1111 static int veth_xdp(struct net_device *dev, struct netdev_bpf *xdp)
1112 {
1113 switch (xdp->command) {
1114 case XDP_SETUP_PROG:
1115 return veth_xdp_set(dev, xdp->prog, xdp->extack);
1116 case XDP_QUERY_PROG:
1117 xdp->prog_id = veth_xdp_query(dev);
1118 return 0;
1119 default:
1120 return -EINVAL;
1121 }
1122 }
1123
1124 static const struct net_device_ops veth_netdev_ops = {
1125 .ndo_init = veth_dev_init,
1126 .ndo_open = veth_open,
1127 .ndo_stop = veth_close,
1128 .ndo_start_xmit = veth_xmit,
1129 .ndo_get_stats64 = veth_get_stats64,
1130 .ndo_set_rx_mode = veth_set_multicast_list,
1131 .ndo_set_mac_address = eth_mac_addr,
1132 #ifdef CONFIG_NET_POLL_CONTROLLER
1133 .ndo_poll_controller = veth_poll_controller,
1134 #endif
1135 .ndo_get_iflink = veth_get_iflink,
1136 .ndo_fix_features = veth_fix_features,
1137 .ndo_features_check = passthru_features_check,
1138 .ndo_set_rx_headroom = veth_set_rx_headroom,
1139 .ndo_bpf = veth_xdp,
1140 .ndo_xdp_xmit = veth_xdp_xmit,
1141 };
1142
1143 #define VETH_FEATURES (NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HW_CSUM | \
1144 NETIF_F_RXCSUM | NETIF_F_SCTP_CRC | NETIF_F_HIGHDMA | \
1145 NETIF_F_GSO_SOFTWARE | NETIF_F_GSO_ENCAP_ALL | \
1146 NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_CTAG_RX | \
1147 NETIF_F_HW_VLAN_STAG_TX | NETIF_F_HW_VLAN_STAG_RX )
1148
1149 static void veth_setup(struct net_device *dev)
1150 {
1151 ether_setup(dev);
1152
1153 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1154 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1155 dev->priv_flags |= IFF_NO_QUEUE;
1156 dev->priv_flags |= IFF_PHONY_HEADROOM;
1157
1158 dev->netdev_ops = &veth_netdev_ops;
1159 dev->ethtool_ops = &veth_ethtool_ops;
1160 dev->features |= NETIF_F_LLTX;
1161 dev->features |= VETH_FEATURES;
1162 dev->vlan_features = dev->features &
1163 ~(NETIF_F_HW_VLAN_CTAG_TX |
1164 NETIF_F_HW_VLAN_STAG_TX |
1165 NETIF_F_HW_VLAN_CTAG_RX |
1166 NETIF_F_HW_VLAN_STAG_RX);
1167 dev->needs_free_netdev = true;
1168 dev->priv_destructor = veth_dev_free;
1169 dev->max_mtu = ETH_MAX_MTU;
1170
1171 dev->hw_features = VETH_FEATURES;
1172 dev->hw_enc_features = VETH_FEATURES;
1173 dev->mpls_features = NETIF_F_HW_CSUM | NETIF_F_GSO_SOFTWARE;
1174 }
1175
1176 /*
1177 * netlink interface
1178 */
1179
1180 static int veth_validate(struct nlattr *tb[], struct nlattr *data[],
1181 struct netlink_ext_ack *extack)
1182 {
1183 if (tb[IFLA_ADDRESS]) {
1184 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1185 return -EINVAL;
1186 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1187 return -EADDRNOTAVAIL;
1188 }
1189 if (tb[IFLA_MTU]) {
1190 if (!is_valid_veth_mtu(nla_get_u32(tb[IFLA_MTU])))
1191 return -EINVAL;
1192 }
1193 return 0;
1194 }
1195
1196 static struct rtnl_link_ops veth_link_ops;
1197
1198 static int veth_newlink(struct net *src_net, struct net_device *dev,
1199 struct nlattr *tb[], struct nlattr *data[],
1200 struct netlink_ext_ack *extack)
1201 {
1202 int err;
1203 struct net_device *peer;
1204 struct veth_priv *priv;
1205 char ifname[IFNAMSIZ];
1206 struct nlattr *peer_tb[IFLA_MAX + 1], **tbp;
1207 unsigned char name_assign_type;
1208 struct ifinfomsg *ifmp;
1209 struct net *net;
1210
1211 /*
1212 * create and register peer first
1213 */
1214 if (data != NULL && data[VETH_INFO_PEER] != NULL) {
1215 struct nlattr *nla_peer;
1216
1217 nla_peer = data[VETH_INFO_PEER];
1218 ifmp = nla_data(nla_peer);
1219 err = rtnl_nla_parse_ifla(peer_tb,
1220 nla_data(nla_peer) + sizeof(struct ifinfomsg),
1221 nla_len(nla_peer) - sizeof(struct ifinfomsg),
1222 NULL);
1223 if (err < 0)
1224 return err;
1225
1226 err = veth_validate(peer_tb, NULL, extack);
1227 if (err < 0)
1228 return err;
1229
1230 tbp = peer_tb;
1231 } else {
1232 ifmp = NULL;
1233 tbp = tb;
1234 }
1235
1236 if (ifmp && tbp[IFLA_IFNAME]) {
1237 nla_strlcpy(ifname, tbp[IFLA_IFNAME], IFNAMSIZ);
1238 name_assign_type = NET_NAME_USER;
1239 } else {
1240 snprintf(ifname, IFNAMSIZ, DRV_NAME "%%d");
1241 name_assign_type = NET_NAME_ENUM;
1242 }
1243
1244 net = rtnl_link_get_net(src_net, tbp);
1245 if (IS_ERR(net))
1246 return PTR_ERR(net);
1247
1248 peer = rtnl_create_link(net, ifname, name_assign_type,
1249 &veth_link_ops, tbp, extack);
1250 if (IS_ERR(peer)) {
1251 put_net(net);
1252 return PTR_ERR(peer);
1253 }
1254
1255 if (!ifmp || !tbp[IFLA_ADDRESS])
1256 eth_hw_addr_random(peer);
1257
1258 if (ifmp && (dev->ifindex != 0))
1259 peer->ifindex = ifmp->ifi_index;
1260
1261 peer->gso_max_size = dev->gso_max_size;
1262 peer->gso_max_segs = dev->gso_max_segs;
1263
1264 err = register_netdevice(peer);
1265 put_net(net);
1266 net = NULL;
1267 if (err < 0)
1268 goto err_register_peer;
1269
1270 netif_carrier_off(peer);
1271
1272 err = rtnl_configure_link(peer, ifmp);
1273 if (err < 0)
1274 goto err_configure_peer;
1275
1276 /*
1277 * register dev last
1278 *
1279 * note, that since we've registered new device the dev's name
1280 * should be re-allocated
1281 */
1282
1283 if (tb[IFLA_ADDRESS] == NULL)
1284 eth_hw_addr_random(dev);
1285
1286 if (tb[IFLA_IFNAME])
1287 nla_strlcpy(dev->name, tb[IFLA_IFNAME], IFNAMSIZ);
1288 else
1289 snprintf(dev->name, IFNAMSIZ, DRV_NAME "%%d");
1290
1291 err = register_netdevice(dev);
1292 if (err < 0)
1293 goto err_register_dev;
1294
1295 netif_carrier_off(dev);
1296
1297 /*
1298 * tie the deviced together
1299 */
1300
1301 priv = netdev_priv(dev);
1302 rcu_assign_pointer(priv->peer, peer);
1303
1304 priv = netdev_priv(peer);
1305 rcu_assign_pointer(priv->peer, dev);
1306
1307 return 0;
1308
1309 err_register_dev:
1310 /* nothing to do */
1311 err_configure_peer:
1312 unregister_netdevice(peer);
1313 return err;
1314
1315 err_register_peer:
1316 free_netdev(peer);
1317 return err;
1318 }
1319
1320 static void veth_dellink(struct net_device *dev, struct list_head *head)
1321 {
1322 struct veth_priv *priv;
1323 struct net_device *peer;
1324
1325 priv = netdev_priv(dev);
1326 peer = rtnl_dereference(priv->peer);
1327
1328 /* Note : dellink() is called from default_device_exit_batch(),
1329 * before a rcu_synchronize() point. The devices are guaranteed
1330 * not being freed before one RCU grace period.
1331 */
1332 RCU_INIT_POINTER(priv->peer, NULL);
1333 unregister_netdevice_queue(dev, head);
1334
1335 if (peer) {
1336 priv = netdev_priv(peer);
1337 RCU_INIT_POINTER(priv->peer, NULL);
1338 unregister_netdevice_queue(peer, head);
1339 }
1340 }
1341
1342 static const struct nla_policy veth_policy[VETH_INFO_MAX + 1] = {
1343 [VETH_INFO_PEER] = { .len = sizeof(struct ifinfomsg) },
1344 };
1345
1346 static struct net *veth_get_link_net(const struct net_device *dev)
1347 {
1348 struct veth_priv *priv = netdev_priv(dev);
1349 struct net_device *peer = rtnl_dereference(priv->peer);
1350
1351 return peer ? dev_net(peer) : dev_net(dev);
1352 }
1353
1354 static struct rtnl_link_ops veth_link_ops = {
1355 .kind = DRV_NAME,
1356 .priv_size = sizeof(struct veth_priv),
1357 .setup = veth_setup,
1358 .validate = veth_validate,
1359 .newlink = veth_newlink,
1360 .dellink = veth_dellink,
1361 .policy = veth_policy,
1362 .maxtype = VETH_INFO_MAX,
1363 .get_link_net = veth_get_link_net,
1364 };
1365
1366 /*
1367 * init/fini
1368 */
1369
1370 static __init int veth_init(void)
1371 {
1372 return rtnl_link_register(&veth_link_ops);
1373 }
1374
1375 static __exit void veth_exit(void)
1376 {
1377 rtnl_link_unregister(&veth_link_ops);
1378 }
1379
1380 module_init(veth_init);
1381 module_exit(veth_exit);
1382
1383 MODULE_DESCRIPTION("Virtual Ethernet Tunnel");
1384 MODULE_LICENSE("GPL v2");
1385 MODULE_ALIAS_RTNL_LINK(DRV_NAME);
Linux with added FPC-III support