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Merge tag 'pci-v3.15-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaa...
[deliverable/linux.git] / net / core / netpoll.c
1 /*
2 * Common framework for low-level network console, dump, and debugger code
3 *
4 * Sep 8 2003 Matt Mackall <mpm@selenic.com>
5 *
6 * based on the netconsole code from:
7 *
8 * Copyright (C) 2001 Ingo Molnar <mingo@redhat.com>
9 * Copyright (C) 2002 Red Hat, Inc.
10 */
11
12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13
14 #include <linux/moduleparam.h>
15 #include <linux/kernel.h>
16 #include <linux/netdevice.h>
17 #include <linux/etherdevice.h>
18 #include <linux/string.h>
19 #include <linux/if_arp.h>
20 #include <linux/inetdevice.h>
21 #include <linux/inet.h>
22 #include <linux/interrupt.h>
23 #include <linux/netpoll.h>
24 #include <linux/sched.h>
25 #include <linux/delay.h>
26 #include <linux/rcupdate.h>
27 #include <linux/workqueue.h>
28 #include <linux/slab.h>
29 #include <linux/export.h>
30 #include <linux/if_vlan.h>
31 #include <net/tcp.h>
32 #include <net/udp.h>
33 #include <net/addrconf.h>
34 #include <net/ndisc.h>
35 #include <net/ip6_checksum.h>
36 #include <asm/unaligned.h>
37 #include <trace/events/napi.h>
38
39 /*
40 * We maintain a small pool of fully-sized skbs, to make sure the
41 * message gets out even in extreme OOM situations.
42 */
43
44 #define MAX_UDP_CHUNK 1460
45 #define MAX_SKBS 32
46
47 static struct sk_buff_head skb_pool;
48
49 static atomic_t trapped;
50
51 DEFINE_STATIC_SRCU(netpoll_srcu);
52
53 #define USEC_PER_POLL 50
54 #define NETPOLL_RX_ENABLED 1
55 #define NETPOLL_RX_DROP 2
56
57 #define MAX_SKB_SIZE \
58 (sizeof(struct ethhdr) + \
59 sizeof(struct iphdr) + \
60 sizeof(struct udphdr) + \
61 MAX_UDP_CHUNK)
62
63 static void zap_completion_queue(void);
64 static void netpoll_neigh_reply(struct sk_buff *skb, struct netpoll_info *npinfo);
65 static void netpoll_async_cleanup(struct work_struct *work);
66
67 static unsigned int carrier_timeout = 4;
68 module_param(carrier_timeout, uint, 0644);
69
70 #define np_info(np, fmt, ...) \
71 pr_info("%s: " fmt, np->name, ##__VA_ARGS__)
72 #define np_err(np, fmt, ...) \
73 pr_err("%s: " fmt, np->name, ##__VA_ARGS__)
74 #define np_notice(np, fmt, ...) \
75 pr_notice("%s: " fmt, np->name, ##__VA_ARGS__)
76
77 static void queue_process(struct work_struct *work)
78 {
79 struct netpoll_info *npinfo =
80 container_of(work, struct netpoll_info, tx_work.work);
81 struct sk_buff *skb;
82 unsigned long flags;
83
84 while ((skb = skb_dequeue(&npinfo->txq))) {
85 struct net_device *dev = skb->dev;
86 const struct net_device_ops *ops = dev->netdev_ops;
87 struct netdev_queue *txq;
88
89 if (!netif_device_present(dev) || !netif_running(dev)) {
90 __kfree_skb(skb);
91 continue;
92 }
93
94 txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb));
95
96 local_irq_save(flags);
97 __netif_tx_lock(txq, smp_processor_id());
98 if (netif_xmit_frozen_or_stopped(txq) ||
99 ops->ndo_start_xmit(skb, dev) != NETDEV_TX_OK) {
100 skb_queue_head(&npinfo->txq, skb);
101 __netif_tx_unlock(txq);
102 local_irq_restore(flags);
103
104 schedule_delayed_work(&npinfo->tx_work, HZ/10);
105 return;
106 }
107 __netif_tx_unlock(txq);
108 local_irq_restore(flags);
109 }
110 }
111
112 static __sum16 checksum_udp(struct sk_buff *skb, struct udphdr *uh,
113 unsigned short ulen, __be32 saddr, __be32 daddr)
114 {
115 __wsum psum;
116
117 if (uh->check == 0 || skb_csum_unnecessary(skb))
118 return 0;
119
120 psum = csum_tcpudp_nofold(saddr, daddr, ulen, IPPROTO_UDP, 0);
121
122 if (skb->ip_summed == CHECKSUM_COMPLETE &&
123 !csum_fold(csum_add(psum, skb->csum)))
124 return 0;
125
126 skb->csum = psum;
127
128 return __skb_checksum_complete(skb);
129 }
130
131 /*
132 * Check whether delayed processing was scheduled for our NIC. If so,
133 * we attempt to grab the poll lock and use ->poll() to pump the card.
134 * If this fails, either we've recursed in ->poll() or it's already
135 * running on another CPU.
136 *
137 * Note: we don't mask interrupts with this lock because we're using
138 * trylock here and interrupts are already disabled in the softirq
139 * case. Further, we test the poll_owner to avoid recursion on UP
140 * systems where the lock doesn't exist.
141 *
142 * In cases where there is bi-directional communications, reading only
143 * one message at a time can lead to packets being dropped by the
144 * network adapter, forcing superfluous retries and possibly timeouts.
145 * Thus, we set our budget to greater than 1.
146 */
147 static int poll_one_napi(struct netpoll_info *npinfo,
148 struct napi_struct *napi, int budget)
149 {
150 int work;
151
152 /* net_rx_action's ->poll() invocations and our's are
153 * synchronized by this test which is only made while
154 * holding the napi->poll_lock.
155 */
156 if (!test_bit(NAPI_STATE_SCHED, &napi->state))
157 return budget;
158
159 npinfo->rx_flags |= NETPOLL_RX_DROP;
160 atomic_inc(&trapped);
161 set_bit(NAPI_STATE_NPSVC, &napi->state);
162
163 work = napi->poll(napi, budget);
164 trace_napi_poll(napi);
165
166 clear_bit(NAPI_STATE_NPSVC, &napi->state);
167 atomic_dec(&trapped);
168 npinfo->rx_flags &= ~NETPOLL_RX_DROP;
169
170 return budget - work;
171 }
172
173 static void poll_napi(struct net_device *dev)
174 {
175 struct napi_struct *napi;
176 int budget = 16;
177
178 list_for_each_entry(napi, &dev->napi_list, dev_list) {
179 if (napi->poll_owner != smp_processor_id() &&
180 spin_trylock(&napi->poll_lock)) {
181 budget = poll_one_napi(rcu_dereference_bh(dev->npinfo),
182 napi, budget);
183 spin_unlock(&napi->poll_lock);
184
185 if (!budget)
186 break;
187 }
188 }
189 }
190
191 static void service_neigh_queue(struct netpoll_info *npi)
192 {
193 if (npi) {
194 struct sk_buff *skb;
195
196 while ((skb = skb_dequeue(&npi->neigh_tx)))
197 netpoll_neigh_reply(skb, npi);
198 }
199 }
200
201 static void netpoll_poll_dev(struct net_device *dev)
202 {
203 const struct net_device_ops *ops;
204 struct netpoll_info *ni = rcu_dereference_bh(dev->npinfo);
205
206 /* Don't do any rx activity if the dev_lock mutex is held
207 * the dev_open/close paths use this to block netpoll activity
208 * while changing device state
209 */
210 if (down_trylock(&ni->dev_lock))
211 return;
212
213 if (!netif_running(dev)) {
214 up(&ni->dev_lock);
215 return;
216 }
217
218 ops = dev->netdev_ops;
219 if (!ops->ndo_poll_controller) {
220 up(&ni->dev_lock);
221 return;
222 }
223
224 /* Process pending work on NIC */
225 ops->ndo_poll_controller(dev);
226
227 poll_napi(dev);
228
229 up(&ni->dev_lock);
230
231 if (dev->flags & IFF_SLAVE) {
232 if (ni) {
233 struct net_device *bond_dev;
234 struct sk_buff *skb;
235 struct netpoll_info *bond_ni;
236
237 bond_dev = netdev_master_upper_dev_get_rcu(dev);
238 bond_ni = rcu_dereference_bh(bond_dev->npinfo);
239 while ((skb = skb_dequeue(&ni->neigh_tx))) {
240 skb->dev = bond_dev;
241 skb_queue_tail(&bond_ni->neigh_tx, skb);
242 }
243 }
244 }
245
246 service_neigh_queue(ni);
247
248 zap_completion_queue();
249 }
250
251 void netpoll_rx_disable(struct net_device *dev)
252 {
253 struct netpoll_info *ni;
254 int idx;
255 might_sleep();
256 idx = srcu_read_lock(&netpoll_srcu);
257 ni = srcu_dereference(dev->npinfo, &netpoll_srcu);
258 if (ni)
259 down(&ni->dev_lock);
260 srcu_read_unlock(&netpoll_srcu, idx);
261 }
262 EXPORT_SYMBOL(netpoll_rx_disable);
263
264 void netpoll_rx_enable(struct net_device *dev)
265 {
266 struct netpoll_info *ni;
267 rcu_read_lock();
268 ni = rcu_dereference(dev->npinfo);
269 if (ni)
270 up(&ni->dev_lock);
271 rcu_read_unlock();
272 }
273 EXPORT_SYMBOL(netpoll_rx_enable);
274
275 static void refill_skbs(void)
276 {
277 struct sk_buff *skb;
278 unsigned long flags;
279
280 spin_lock_irqsave(&skb_pool.lock, flags);
281 while (skb_pool.qlen < MAX_SKBS) {
282 skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC);
283 if (!skb)
284 break;
285
286 __skb_queue_tail(&skb_pool, skb);
287 }
288 spin_unlock_irqrestore(&skb_pool.lock, flags);
289 }
290
291 static void zap_completion_queue(void)
292 {
293 unsigned long flags;
294 struct softnet_data *sd = &get_cpu_var(softnet_data);
295
296 if (sd->completion_queue) {
297 struct sk_buff *clist;
298
299 local_irq_save(flags);
300 clist = sd->completion_queue;
301 sd->completion_queue = NULL;
302 local_irq_restore(flags);
303
304 while (clist != NULL) {
305 struct sk_buff *skb = clist;
306 clist = clist->next;
307 if (skb->destructor) {
308 atomic_inc(&skb->users);
309 dev_kfree_skb_any(skb); /* put this one back */
310 } else {
311 __kfree_skb(skb);
312 }
313 }
314 }
315
316 put_cpu_var(softnet_data);
317 }
318
319 static struct sk_buff *find_skb(struct netpoll *np, int len, int reserve)
320 {
321 int count = 0;
322 struct sk_buff *skb;
323
324 zap_completion_queue();
325 refill_skbs();
326 repeat:
327
328 skb = alloc_skb(len, GFP_ATOMIC);
329 if (!skb)
330 skb = skb_dequeue(&skb_pool);
331
332 if (!skb) {
333 if (++count < 10) {
334 netpoll_poll_dev(np->dev);
335 goto repeat;
336 }
337 return NULL;
338 }
339
340 atomic_set(&skb->users, 1);
341 skb_reserve(skb, reserve);
342 return skb;
343 }
344
345 static int netpoll_owner_active(struct net_device *dev)
346 {
347 struct napi_struct *napi;
348
349 list_for_each_entry(napi, &dev->napi_list, dev_list) {
350 if (napi->poll_owner == smp_processor_id())
351 return 1;
352 }
353 return 0;
354 }
355
356 /* call with IRQ disabled */
357 void netpoll_send_skb_on_dev(struct netpoll *np, struct sk_buff *skb,
358 struct net_device *dev)
359 {
360 int status = NETDEV_TX_BUSY;
361 unsigned long tries;
362 const struct net_device_ops *ops = dev->netdev_ops;
363 /* It is up to the caller to keep npinfo alive. */
364 struct netpoll_info *npinfo;
365
366 WARN_ON_ONCE(!irqs_disabled());
367
368 npinfo = rcu_dereference_bh(np->dev->npinfo);
369 if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) {
370 __kfree_skb(skb);
371 return;
372 }
373
374 /* don't get messages out of order, and no recursion */
375 if (skb_queue_len(&npinfo->txq) == 0 && !netpoll_owner_active(dev)) {
376 struct netdev_queue *txq;
377
378 txq = netdev_pick_tx(dev, skb, NULL);
379
380 /* try until next clock tick */
381 for (tries = jiffies_to_usecs(1)/USEC_PER_POLL;
382 tries > 0; --tries) {
383 if (__netif_tx_trylock(txq)) {
384 if (!netif_xmit_stopped(txq)) {
385 if (vlan_tx_tag_present(skb) &&
386 !vlan_hw_offload_capable(netif_skb_features(skb),
387 skb->vlan_proto)) {
388 skb = __vlan_put_tag(skb, skb->vlan_proto, vlan_tx_tag_get(skb));
389 if (unlikely(!skb)) {
390 /* This is actually a packet drop, but we
391 * don't want the code at the end of this
392 * function to try and re-queue a NULL skb.
393 */
394 status = NETDEV_TX_OK;
395 goto unlock_txq;
396 }
397 skb->vlan_tci = 0;
398 }
399
400 status = ops->ndo_start_xmit(skb, dev);
401 if (status == NETDEV_TX_OK)
402 txq_trans_update(txq);
403 }
404 unlock_txq:
405 __netif_tx_unlock(txq);
406
407 if (status == NETDEV_TX_OK)
408 break;
409
410 }
411
412 /* tickle device maybe there is some cleanup */
413 netpoll_poll_dev(np->dev);
414
415 udelay(USEC_PER_POLL);
416 }
417
418 WARN_ONCE(!irqs_disabled(),
419 "netpoll_send_skb_on_dev(): %s enabled interrupts in poll (%pF)\n",
420 dev->name, ops->ndo_start_xmit);
421
422 }
423
424 if (status != NETDEV_TX_OK) {
425 skb_queue_tail(&npinfo->txq, skb);
426 schedule_delayed_work(&npinfo->tx_work,0);
427 }
428 }
429 EXPORT_SYMBOL(netpoll_send_skb_on_dev);
430
431 void netpoll_send_udp(struct netpoll *np, const char *msg, int len)
432 {
433 int total_len, ip_len, udp_len;
434 struct sk_buff *skb;
435 struct udphdr *udph;
436 struct iphdr *iph;
437 struct ethhdr *eth;
438 static atomic_t ip_ident;
439 struct ipv6hdr *ip6h;
440
441 udp_len = len + sizeof(*udph);
442 if (np->ipv6)
443 ip_len = udp_len + sizeof(*ip6h);
444 else
445 ip_len = udp_len + sizeof(*iph);
446
447 total_len = ip_len + LL_RESERVED_SPACE(np->dev);
448
449 skb = find_skb(np, total_len + np->dev->needed_tailroom,
450 total_len - len);
451 if (!skb)
452 return;
453
454 skb_copy_to_linear_data(skb, msg, len);
455 skb_put(skb, len);
456
457 skb_push(skb, sizeof(*udph));
458 skb_reset_transport_header(skb);
459 udph = udp_hdr(skb);
460 udph->source = htons(np->local_port);
461 udph->dest = htons(np->remote_port);
462 udph->len = htons(udp_len);
463
464 if (np->ipv6) {
465 udph->check = 0;
466 udph->check = csum_ipv6_magic(&np->local_ip.in6,
467 &np->remote_ip.in6,
468 udp_len, IPPROTO_UDP,
469 csum_partial(udph, udp_len, 0));
470 if (udph->check == 0)
471 udph->check = CSUM_MANGLED_0;
472
473 skb_push(skb, sizeof(*ip6h));
474 skb_reset_network_header(skb);
475 ip6h = ipv6_hdr(skb);
476
477 /* ip6h->version = 6; ip6h->priority = 0; */
478 put_unaligned(0x60, (unsigned char *)ip6h);
479 ip6h->flow_lbl[0] = 0;
480 ip6h->flow_lbl[1] = 0;
481 ip6h->flow_lbl[2] = 0;
482
483 ip6h->payload_len = htons(sizeof(struct udphdr) + len);
484 ip6h->nexthdr = IPPROTO_UDP;
485 ip6h->hop_limit = 32;
486 ip6h->saddr = np->local_ip.in6;
487 ip6h->daddr = np->remote_ip.in6;
488
489 eth = (struct ethhdr *) skb_push(skb, ETH_HLEN);
490 skb_reset_mac_header(skb);
491 skb->protocol = eth->h_proto = htons(ETH_P_IPV6);
492 } else {
493 udph->check = 0;
494 udph->check = csum_tcpudp_magic(np->local_ip.ip,
495 np->remote_ip.ip,
496 udp_len, IPPROTO_UDP,
497 csum_partial(udph, udp_len, 0));
498 if (udph->check == 0)
499 udph->check = CSUM_MANGLED_0;
500
501 skb_push(skb, sizeof(*iph));
502 skb_reset_network_header(skb);
503 iph = ip_hdr(skb);
504
505 /* iph->version = 4; iph->ihl = 5; */
506 put_unaligned(0x45, (unsigned char *)iph);
507 iph->tos = 0;
508 put_unaligned(htons(ip_len), &(iph->tot_len));
509 iph->id = htons(atomic_inc_return(&ip_ident));
510 iph->frag_off = 0;
511 iph->ttl = 64;
512 iph->protocol = IPPROTO_UDP;
513 iph->check = 0;
514 put_unaligned(np->local_ip.ip, &(iph->saddr));
515 put_unaligned(np->remote_ip.ip, &(iph->daddr));
516 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl);
517
518 eth = (struct ethhdr *) skb_push(skb, ETH_HLEN);
519 skb_reset_mac_header(skb);
520 skb->protocol = eth->h_proto = htons(ETH_P_IP);
521 }
522
523 ether_addr_copy(eth->h_source, np->dev->dev_addr);
524 ether_addr_copy(eth->h_dest, np->remote_mac);
525
526 skb->dev = np->dev;
527
528 netpoll_send_skb(np, skb);
529 }
530 EXPORT_SYMBOL(netpoll_send_udp);
531
532 static void netpoll_neigh_reply(struct sk_buff *skb, struct netpoll_info *npinfo)
533 {
534 int size, type = ARPOP_REPLY;
535 __be32 sip, tip;
536 unsigned char *sha;
537 struct sk_buff *send_skb;
538 struct netpoll *np, *tmp;
539 unsigned long flags;
540 int hlen, tlen;
541 int hits = 0, proto;
542
543 if (list_empty(&npinfo->rx_np))
544 return;
545
546 /* Before checking the packet, we do some early
547 inspection whether this is interesting at all */
548 spin_lock_irqsave(&npinfo->rx_lock, flags);
549 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) {
550 if (np->dev == skb->dev)
551 hits++;
552 }
553 spin_unlock_irqrestore(&npinfo->rx_lock, flags);
554
555 /* No netpoll struct is using this dev */
556 if (!hits)
557 return;
558
559 proto = ntohs(eth_hdr(skb)->h_proto);
560 if (proto == ETH_P_ARP) {
561 struct arphdr *arp;
562 unsigned char *arp_ptr;
563 /* No arp on this interface */
564 if (skb->dev->flags & IFF_NOARP)
565 return;
566
567 if (!pskb_may_pull(skb, arp_hdr_len(skb->dev)))
568 return;
569
570 skb_reset_network_header(skb);
571 skb_reset_transport_header(skb);
572 arp = arp_hdr(skb);
573
574 if ((arp->ar_hrd != htons(ARPHRD_ETHER) &&
575 arp->ar_hrd != htons(ARPHRD_IEEE802)) ||
576 arp->ar_pro != htons(ETH_P_IP) ||
577 arp->ar_op != htons(ARPOP_REQUEST))
578 return;
579
580 arp_ptr = (unsigned char *)(arp+1);
581 /* save the location of the src hw addr */
582 sha = arp_ptr;
583 arp_ptr += skb->dev->addr_len;
584 memcpy(&sip, arp_ptr, 4);
585 arp_ptr += 4;
586 /* If we actually cared about dst hw addr,
587 it would get copied here */
588 arp_ptr += skb->dev->addr_len;
589 memcpy(&tip, arp_ptr, 4);
590
591 /* Should we ignore arp? */
592 if (ipv4_is_loopback(tip) || ipv4_is_multicast(tip))
593 return;
594
595 size = arp_hdr_len(skb->dev);
596
597 spin_lock_irqsave(&npinfo->rx_lock, flags);
598 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) {
599 if (tip != np->local_ip.ip)
600 continue;
601
602 hlen = LL_RESERVED_SPACE(np->dev);
603 tlen = np->dev->needed_tailroom;
604 send_skb = find_skb(np, size + hlen + tlen, hlen);
605 if (!send_skb)
606 continue;
607
608 skb_reset_network_header(send_skb);
609 arp = (struct arphdr *) skb_put(send_skb, size);
610 send_skb->dev = skb->dev;
611 send_skb->protocol = htons(ETH_P_ARP);
612
613 /* Fill the device header for the ARP frame */
614 if (dev_hard_header(send_skb, skb->dev, ETH_P_ARP,
615 sha, np->dev->dev_addr,
616 send_skb->len) < 0) {
617 kfree_skb(send_skb);
618 continue;
619 }
620
621 /*
622 * Fill out the arp protocol part.
623 *
624 * we only support ethernet device type,
625 * which (according to RFC 1390) should
626 * always equal 1 (Ethernet).
627 */
628
629 arp->ar_hrd = htons(np->dev->type);
630 arp->ar_pro = htons(ETH_P_IP);
631 arp->ar_hln = np->dev->addr_len;
632 arp->ar_pln = 4;
633 arp->ar_op = htons(type);
634
635 arp_ptr = (unsigned char *)(arp + 1);
636 memcpy(arp_ptr, np->dev->dev_addr, np->dev->addr_len);
637 arp_ptr += np->dev->addr_len;
638 memcpy(arp_ptr, &tip, 4);
639 arp_ptr += 4;
640 memcpy(arp_ptr, sha, np->dev->addr_len);
641 arp_ptr += np->dev->addr_len;
642 memcpy(arp_ptr, &sip, 4);
643
644 netpoll_send_skb(np, send_skb);
645
646 /* If there are several rx_skb_hooks for the same
647 * address we're fine by sending a single reply
648 */
649 break;
650 }
651 spin_unlock_irqrestore(&npinfo->rx_lock, flags);
652 } else if( proto == ETH_P_IPV6) {
653 #if IS_ENABLED(CONFIG_IPV6)
654 struct nd_msg *msg;
655 u8 *lladdr = NULL;
656 struct ipv6hdr *hdr;
657 struct icmp6hdr *icmp6h;
658 const struct in6_addr *saddr;
659 const struct in6_addr *daddr;
660 struct inet6_dev *in6_dev = NULL;
661 struct in6_addr *target;
662
663 in6_dev = in6_dev_get(skb->dev);
664 if (!in6_dev || !in6_dev->cnf.accept_ra)
665 return;
666
667 if (!pskb_may_pull(skb, skb->len))
668 return;
669
670 msg = (struct nd_msg *)skb_transport_header(skb);
671
672 __skb_push(skb, skb->data - skb_transport_header(skb));
673
674 if (ipv6_hdr(skb)->hop_limit != 255)
675 return;
676 if (msg->icmph.icmp6_code != 0)
677 return;
678 if (msg->icmph.icmp6_type != NDISC_NEIGHBOUR_SOLICITATION)
679 return;
680
681 saddr = &ipv6_hdr(skb)->saddr;
682 daddr = &ipv6_hdr(skb)->daddr;
683
684 size = sizeof(struct icmp6hdr) + sizeof(struct in6_addr);
685
686 spin_lock_irqsave(&npinfo->rx_lock, flags);
687 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) {
688 if (!ipv6_addr_equal(daddr, &np->local_ip.in6))
689 continue;
690
691 hlen = LL_RESERVED_SPACE(np->dev);
692 tlen = np->dev->needed_tailroom;
693 send_skb = find_skb(np, size + hlen + tlen, hlen);
694 if (!send_skb)
695 continue;
696
697 send_skb->protocol = htons(ETH_P_IPV6);
698 send_skb->dev = skb->dev;
699
700 skb_reset_network_header(send_skb);
701 hdr = (struct ipv6hdr *) skb_put(send_skb, sizeof(struct ipv6hdr));
702 *(__be32*)hdr = htonl(0x60000000);
703 hdr->payload_len = htons(size);
704 hdr->nexthdr = IPPROTO_ICMPV6;
705 hdr->hop_limit = 255;
706 hdr->saddr = *saddr;
707 hdr->daddr = *daddr;
708
709 icmp6h = (struct icmp6hdr *) skb_put(send_skb, sizeof(struct icmp6hdr));
710 icmp6h->icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT;
711 icmp6h->icmp6_router = 0;
712 icmp6h->icmp6_solicited = 1;
713
714 target = (struct in6_addr *) skb_put(send_skb, sizeof(struct in6_addr));
715 *target = msg->target;
716 icmp6h->icmp6_cksum = csum_ipv6_magic(saddr, daddr, size,
717 IPPROTO_ICMPV6,
718 csum_partial(icmp6h,
719 size, 0));
720
721 if (dev_hard_header(send_skb, skb->dev, ETH_P_IPV6,
722 lladdr, np->dev->dev_addr,
723 send_skb->len) < 0) {
724 kfree_skb(send_skb);
725 continue;
726 }
727
728 netpoll_send_skb(np, send_skb);
729
730 /* If there are several rx_skb_hooks for the same
731 * address, we're fine by sending a single reply
732 */
733 break;
734 }
735 spin_unlock_irqrestore(&npinfo->rx_lock, flags);
736 #endif
737 }
738 }
739
740 static bool pkt_is_ns(struct sk_buff *skb)
741 {
742 struct nd_msg *msg;
743 struct ipv6hdr *hdr;
744
745 if (skb->protocol != htons(ETH_P_IPV6))
746 return false;
747 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr) + sizeof(struct nd_msg)))
748 return false;
749
750 msg = (struct nd_msg *)skb_transport_header(skb);
751 __skb_push(skb, skb->data - skb_transport_header(skb));
752 hdr = ipv6_hdr(skb);
753
754 if (hdr->nexthdr != IPPROTO_ICMPV6)
755 return false;
756 if (hdr->hop_limit != 255)
757 return false;
758 if (msg->icmph.icmp6_code != 0)
759 return false;
760 if (msg->icmph.icmp6_type != NDISC_NEIGHBOUR_SOLICITATION)
761 return false;
762
763 return true;
764 }
765
766 int __netpoll_rx(struct sk_buff *skb, struct netpoll_info *npinfo)
767 {
768 int proto, len, ulen, data_len;
769 int hits = 0, offset;
770 const struct iphdr *iph;
771 struct udphdr *uh;
772 struct netpoll *np, *tmp;
773 uint16_t source;
774
775 if (list_empty(&npinfo->rx_np))
776 goto out;
777
778 if (skb->dev->type != ARPHRD_ETHER)
779 goto out;
780
781 /* check if netpoll clients need ARP */
782 if (skb->protocol == htons(ETH_P_ARP) && atomic_read(&trapped)) {
783 skb_queue_tail(&npinfo->neigh_tx, skb);
784 return 1;
785 } else if (pkt_is_ns(skb) && atomic_read(&trapped)) {
786 skb_queue_tail(&npinfo->neigh_tx, skb);
787 return 1;
788 }
789
790 if (skb->protocol == cpu_to_be16(ETH_P_8021Q)) {
791 skb = vlan_untag(skb);
792 if (unlikely(!skb))
793 goto out;
794 }
795
796 proto = ntohs(eth_hdr(skb)->h_proto);
797 if (proto != ETH_P_IP && proto != ETH_P_IPV6)
798 goto out;
799 if (skb->pkt_type == PACKET_OTHERHOST)
800 goto out;
801 if (skb_shared(skb))
802 goto out;
803
804 if (proto == ETH_P_IP) {
805 if (!pskb_may_pull(skb, sizeof(struct iphdr)))
806 goto out;
807 iph = (struct iphdr *)skb->data;
808 if (iph->ihl < 5 || iph->version != 4)
809 goto out;
810 if (!pskb_may_pull(skb, iph->ihl*4))
811 goto out;
812 iph = (struct iphdr *)skb->data;
813 if (ip_fast_csum((u8 *)iph, iph->ihl) != 0)
814 goto out;
815
816 len = ntohs(iph->tot_len);
817 if (skb->len < len || len < iph->ihl*4)
818 goto out;
819
820 /*
821 * Our transport medium may have padded the buffer out.
822 * Now We trim to the true length of the frame.
823 */
824 if (pskb_trim_rcsum(skb, len))
825 goto out;
826
827 iph = (struct iphdr *)skb->data;
828 if (iph->protocol != IPPROTO_UDP)
829 goto out;
830
831 len -= iph->ihl*4;
832 uh = (struct udphdr *)(((char *)iph) + iph->ihl*4);
833 offset = (unsigned char *)(uh + 1) - skb->data;
834 ulen = ntohs(uh->len);
835 data_len = skb->len - offset;
836 source = ntohs(uh->source);
837
838 if (ulen != len)
839 goto out;
840 if (checksum_udp(skb, uh, ulen, iph->saddr, iph->daddr))
841 goto out;
842 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) {
843 if (np->local_ip.ip && np->local_ip.ip != iph->daddr)
844 continue;
845 if (np->remote_ip.ip && np->remote_ip.ip != iph->saddr)
846 continue;
847 if (np->local_port && np->local_port != ntohs(uh->dest))
848 continue;
849
850 np->rx_skb_hook(np, source, skb, offset, data_len);
851 hits++;
852 }
853 } else {
854 #if IS_ENABLED(CONFIG_IPV6)
855 const struct ipv6hdr *ip6h;
856
857 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
858 goto out;
859 ip6h = (struct ipv6hdr *)skb->data;
860 if (ip6h->version != 6)
861 goto out;
862 len = ntohs(ip6h->payload_len);
863 if (!len)
864 goto out;
865 if (len + sizeof(struct ipv6hdr) > skb->len)
866 goto out;
867 if (pskb_trim_rcsum(skb, len + sizeof(struct ipv6hdr)))
868 goto out;
869 ip6h = ipv6_hdr(skb);
870 if (!pskb_may_pull(skb, sizeof(struct udphdr)))
871 goto out;
872 uh = udp_hdr(skb);
873 offset = (unsigned char *)(uh + 1) - skb->data;
874 ulen = ntohs(uh->len);
875 data_len = skb->len - offset;
876 source = ntohs(uh->source);
877 if (ulen != skb->len)
878 goto out;
879 if (udp6_csum_init(skb, uh, IPPROTO_UDP))
880 goto out;
881 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) {
882 if (!ipv6_addr_equal(&np->local_ip.in6, &ip6h->daddr))
883 continue;
884 if (!ipv6_addr_equal(&np->remote_ip.in6, &ip6h->saddr))
885 continue;
886 if (np->local_port && np->local_port != ntohs(uh->dest))
887 continue;
888
889 np->rx_skb_hook(np, source, skb, offset, data_len);
890 hits++;
891 }
892 #endif
893 }
894
895 if (!hits)
896 goto out;
897
898 kfree_skb(skb);
899 return 1;
900
901 out:
902 if (atomic_read(&trapped)) {
903 kfree_skb(skb);
904 return 1;
905 }
906
907 return 0;
908 }
909
910 void netpoll_print_options(struct netpoll *np)
911 {
912 np_info(np, "local port %d\n", np->local_port);
913 if (np->ipv6)
914 np_info(np, "local IPv6 address %pI6c\n", &np->local_ip.in6);
915 else
916 np_info(np, "local IPv4 address %pI4\n", &np->local_ip.ip);
917 np_info(np, "interface '%s'\n", np->dev_name);
918 np_info(np, "remote port %d\n", np->remote_port);
919 if (np->ipv6)
920 np_info(np, "remote IPv6 address %pI6c\n", &np->remote_ip.in6);
921 else
922 np_info(np, "remote IPv4 address %pI4\n", &np->remote_ip.ip);
923 np_info(np, "remote ethernet address %pM\n", np->remote_mac);
924 }
925 EXPORT_SYMBOL(netpoll_print_options);
926
927 static int netpoll_parse_ip_addr(const char *str, union inet_addr *addr)
928 {
929 const char *end;
930
931 if (!strchr(str, ':') &&
932 in4_pton(str, -1, (void *)addr, -1, &end) > 0) {
933 if (!*end)
934 return 0;
935 }
936 if (in6_pton(str, -1, addr->in6.s6_addr, -1, &end) > 0) {
937 #if IS_ENABLED(CONFIG_IPV6)
938 if (!*end)
939 return 1;
940 #else
941 return -1;
942 #endif
943 }
944 return -1;
945 }
946
947 int netpoll_parse_options(struct netpoll *np, char *opt)
948 {
949 char *cur=opt, *delim;
950 int ipv6;
951 bool ipversion_set = false;
952
953 if (*cur != '@') {
954 if ((delim = strchr(cur, '@')) == NULL)
955 goto parse_failed;
956 *delim = 0;
957 if (kstrtou16(cur, 10, &np->local_port))
958 goto parse_failed;
959 cur = delim;
960 }
961 cur++;
962
963 if (*cur != '/') {
964 ipversion_set = true;
965 if ((delim = strchr(cur, '/')) == NULL)
966 goto parse_failed;
967 *delim = 0;
968 ipv6 = netpoll_parse_ip_addr(cur, &np->local_ip);
969 if (ipv6 < 0)
970 goto parse_failed;
971 else
972 np->ipv6 = (bool)ipv6;
973 cur = delim;
974 }
975 cur++;
976
977 if (*cur != ',') {
978 /* parse out dev name */
979 if ((delim = strchr(cur, ',')) == NULL)
980 goto parse_failed;
981 *delim = 0;
982 strlcpy(np->dev_name, cur, sizeof(np->dev_name));
983 cur = delim;
984 }
985 cur++;
986
987 if (*cur != '@') {
988 /* dst port */
989 if ((delim = strchr(cur, '@')) == NULL)
990 goto parse_failed;
991 *delim = 0;
992 if (*cur == ' ' || *cur == '\t')
993 np_info(np, "warning: whitespace is not allowed\n");
994 if (kstrtou16(cur, 10, &np->remote_port))
995 goto parse_failed;
996 cur = delim;
997 }
998 cur++;
999
1000 /* dst ip */
1001 if ((delim = strchr(cur, '/')) == NULL)
1002 goto parse_failed;
1003 *delim = 0;
1004 ipv6 = netpoll_parse_ip_addr(cur, &np->remote_ip);
1005 if (ipv6 < 0)
1006 goto parse_failed;
1007 else if (ipversion_set && np->ipv6 != (bool)ipv6)
1008 goto parse_failed;
1009 else
1010 np->ipv6 = (bool)ipv6;
1011 cur = delim + 1;
1012
1013 if (*cur != 0) {
1014 /* MAC address */
1015 if (!mac_pton(cur, np->remote_mac))
1016 goto parse_failed;
1017 }
1018
1019 netpoll_print_options(np);
1020
1021 return 0;
1022
1023 parse_failed:
1024 np_info(np, "couldn't parse config at '%s'!\n", cur);
1025 return -1;
1026 }
1027 EXPORT_SYMBOL(netpoll_parse_options);
1028
1029 int __netpoll_setup(struct netpoll *np, struct net_device *ndev, gfp_t gfp)
1030 {
1031 struct netpoll_info *npinfo;
1032 const struct net_device_ops *ops;
1033 unsigned long flags;
1034 int err;
1035
1036 np->dev = ndev;
1037 strlcpy(np->dev_name, ndev->name, IFNAMSIZ);
1038 INIT_WORK(&np->cleanup_work, netpoll_async_cleanup);
1039
1040 if ((ndev->priv_flags & IFF_DISABLE_NETPOLL) ||
1041 !ndev->netdev_ops->ndo_poll_controller) {
1042 np_err(np, "%s doesn't support polling, aborting\n",
1043 np->dev_name);
1044 err = -ENOTSUPP;
1045 goto out;
1046 }
1047
1048 if (!ndev->npinfo) {
1049 npinfo = kmalloc(sizeof(*npinfo), gfp);
1050 if (!npinfo) {
1051 err = -ENOMEM;
1052 goto out;
1053 }
1054
1055 npinfo->rx_flags = 0;
1056 INIT_LIST_HEAD(&npinfo->rx_np);
1057
1058 spin_lock_init(&npinfo->rx_lock);
1059 sema_init(&npinfo->dev_lock, 1);
1060 skb_queue_head_init(&npinfo->neigh_tx);
1061 skb_queue_head_init(&npinfo->txq);
1062 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process);
1063
1064 atomic_set(&npinfo->refcnt, 1);
1065
1066 ops = np->dev->netdev_ops;
1067 if (ops->ndo_netpoll_setup) {
1068 err = ops->ndo_netpoll_setup(ndev, npinfo, gfp);
1069 if (err)
1070 goto free_npinfo;
1071 }
1072 } else {
1073 npinfo = rtnl_dereference(ndev->npinfo);
1074 atomic_inc(&npinfo->refcnt);
1075 }
1076
1077 npinfo->netpoll = np;
1078
1079 if (np->rx_skb_hook) {
1080 spin_lock_irqsave(&npinfo->rx_lock, flags);
1081 npinfo->rx_flags |= NETPOLL_RX_ENABLED;
1082 list_add_tail(&np->rx, &npinfo->rx_np);
1083 spin_unlock_irqrestore(&npinfo->rx_lock, flags);
1084 }
1085
1086 /* last thing to do is link it to the net device structure */
1087 rcu_assign_pointer(ndev->npinfo, npinfo);
1088
1089 return 0;
1090
1091 free_npinfo:
1092 kfree(npinfo);
1093 out:
1094 return err;
1095 }
1096 EXPORT_SYMBOL_GPL(__netpoll_setup);
1097
1098 int netpoll_setup(struct netpoll *np)
1099 {
1100 struct net_device *ndev = NULL;
1101 struct in_device *in_dev;
1102 int err;
1103
1104 rtnl_lock();
1105 if (np->dev_name) {
1106 struct net *net = current->nsproxy->net_ns;
1107 ndev = __dev_get_by_name(net, np->dev_name);
1108 }
1109 if (!ndev) {
1110 np_err(np, "%s doesn't exist, aborting\n", np->dev_name);
1111 err = -ENODEV;
1112 goto unlock;
1113 }
1114 dev_hold(ndev);
1115
1116 if (netdev_master_upper_dev_get(ndev)) {
1117 np_err(np, "%s is a slave device, aborting\n", np->dev_name);
1118 err = -EBUSY;
1119 goto put;
1120 }
1121
1122 if (!netif_running(ndev)) {
1123 unsigned long atmost, atleast;
1124
1125 np_info(np, "device %s not up yet, forcing it\n", np->dev_name);
1126
1127 err = dev_open(ndev);
1128
1129 if (err) {
1130 np_err(np, "failed to open %s\n", ndev->name);
1131 goto put;
1132 }
1133
1134 rtnl_unlock();
1135 atleast = jiffies + HZ/10;
1136 atmost = jiffies + carrier_timeout * HZ;
1137 while (!netif_carrier_ok(ndev)) {
1138 if (time_after(jiffies, atmost)) {
1139 np_notice(np, "timeout waiting for carrier\n");
1140 break;
1141 }
1142 msleep(1);
1143 }
1144
1145 /* If carrier appears to come up instantly, we don't
1146 * trust it and pause so that we don't pump all our
1147 * queued console messages into the bitbucket.
1148 */
1149
1150 if (time_before(jiffies, atleast)) {
1151 np_notice(np, "carrier detect appears untrustworthy, waiting 4 seconds\n");
1152 msleep(4000);
1153 }
1154 rtnl_lock();
1155 }
1156
1157 if (!np->local_ip.ip) {
1158 if (!np->ipv6) {
1159 in_dev = __in_dev_get_rtnl(ndev);
1160
1161 if (!in_dev || !in_dev->ifa_list) {
1162 np_err(np, "no IP address for %s, aborting\n",
1163 np->dev_name);
1164 err = -EDESTADDRREQ;
1165 goto put;
1166 }
1167
1168 np->local_ip.ip = in_dev->ifa_list->ifa_local;
1169 np_info(np, "local IP %pI4\n", &np->local_ip.ip);
1170 } else {
1171 #if IS_ENABLED(CONFIG_IPV6)
1172 struct inet6_dev *idev;
1173
1174 err = -EDESTADDRREQ;
1175 idev = __in6_dev_get(ndev);
1176 if (idev) {
1177 struct inet6_ifaddr *ifp;
1178
1179 read_lock_bh(&idev->lock);
1180 list_for_each_entry(ifp, &idev->addr_list, if_list) {
1181 if (ipv6_addr_type(&ifp->addr) & IPV6_ADDR_LINKLOCAL)
1182 continue;
1183 np->local_ip.in6 = ifp->addr;
1184 err = 0;
1185 break;
1186 }
1187 read_unlock_bh(&idev->lock);
1188 }
1189 if (err) {
1190 np_err(np, "no IPv6 address for %s, aborting\n",
1191 np->dev_name);
1192 goto put;
1193 } else
1194 np_info(np, "local IPv6 %pI6c\n", &np->local_ip.in6);
1195 #else
1196 np_err(np, "IPv6 is not supported %s, aborting\n",
1197 np->dev_name);
1198 err = -EINVAL;
1199 goto put;
1200 #endif
1201 }
1202 }
1203
1204 /* fill up the skb queue */
1205 refill_skbs();
1206
1207 err = __netpoll_setup(np, ndev, GFP_KERNEL);
1208 if (err)
1209 goto put;
1210
1211 rtnl_unlock();
1212 return 0;
1213
1214 put:
1215 dev_put(ndev);
1216 unlock:
1217 rtnl_unlock();
1218 return err;
1219 }
1220 EXPORT_SYMBOL(netpoll_setup);
1221
1222 static int __init netpoll_init(void)
1223 {
1224 skb_queue_head_init(&skb_pool);
1225 return 0;
1226 }
1227 core_initcall(netpoll_init);
1228
1229 static void rcu_cleanup_netpoll_info(struct rcu_head *rcu_head)
1230 {
1231 struct netpoll_info *npinfo =
1232 container_of(rcu_head, struct netpoll_info, rcu);
1233
1234 skb_queue_purge(&npinfo->neigh_tx);
1235 skb_queue_purge(&npinfo->txq);
1236
1237 /* we can't call cancel_delayed_work_sync here, as we are in softirq */
1238 cancel_delayed_work(&npinfo->tx_work);
1239
1240 /* clean after last, unfinished work */
1241 __skb_queue_purge(&npinfo->txq);
1242 /* now cancel it again */
1243 cancel_delayed_work(&npinfo->tx_work);
1244 kfree(npinfo);
1245 }
1246
1247 void __netpoll_cleanup(struct netpoll *np)
1248 {
1249 struct netpoll_info *npinfo;
1250 unsigned long flags;
1251
1252 /* rtnl_dereference would be preferable here but
1253 * rcu_cleanup_netpoll path can put us in here safely without
1254 * holding the rtnl, so plain rcu_dereference it is
1255 */
1256 npinfo = rtnl_dereference(np->dev->npinfo);
1257 if (!npinfo)
1258 return;
1259
1260 if (!list_empty(&npinfo->rx_np)) {
1261 spin_lock_irqsave(&npinfo->rx_lock, flags);
1262 list_del(&np->rx);
1263 if (list_empty(&npinfo->rx_np))
1264 npinfo->rx_flags &= ~NETPOLL_RX_ENABLED;
1265 spin_unlock_irqrestore(&npinfo->rx_lock, flags);
1266 }
1267
1268 synchronize_srcu(&netpoll_srcu);
1269
1270 if (atomic_dec_and_test(&npinfo->refcnt)) {
1271 const struct net_device_ops *ops;
1272
1273 ops = np->dev->netdev_ops;
1274 if (ops->ndo_netpoll_cleanup)
1275 ops->ndo_netpoll_cleanup(np->dev);
1276
1277 rcu_assign_pointer(np->dev->npinfo, NULL);
1278 call_rcu_bh(&npinfo->rcu, rcu_cleanup_netpoll_info);
1279 }
1280 }
1281 EXPORT_SYMBOL_GPL(__netpoll_cleanup);
1282
1283 static void netpoll_async_cleanup(struct work_struct *work)
1284 {
1285 struct netpoll *np = container_of(work, struct netpoll, cleanup_work);
1286
1287 rtnl_lock();
1288 __netpoll_cleanup(np);
1289 rtnl_unlock();
1290 kfree(np);
1291 }
1292
1293 void __netpoll_free_async(struct netpoll *np)
1294 {
1295 schedule_work(&np->cleanup_work);
1296 }
1297 EXPORT_SYMBOL_GPL(__netpoll_free_async);
1298
1299 void netpoll_cleanup(struct netpoll *np)
1300 {
1301 rtnl_lock();
1302 if (!np->dev)
1303 goto out;
1304 __netpoll_cleanup(np);
1305 dev_put(np->dev);
1306 np->dev = NULL;
1307 out:
1308 rtnl_unlock();
1309 }
1310 EXPORT_SYMBOL(netpoll_cleanup);
1311
1312 int netpoll_trap(void)
1313 {
1314 return atomic_read(&trapped);
1315 }
1316 EXPORT_SYMBOL(netpoll_trap);
1317
1318 void netpoll_set_trap(int trap)
1319 {
1320 if (trap)
1321 atomic_inc(&trapped);
1322 else
1323 atomic_dec(&trapped);
1324 }
1325 EXPORT_SYMBOL(netpoll_set_trap);
Linux kernel - Deliverables
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