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Merge tag 'for-linus-3.11-merge-window-part-2' of git://git.kernel.org/pub/scm/linux...
[linux-2.6.git] / net / core / netpoll.c
blob2c637e9a0b277ff2a987edf139622d7580b43e02
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);
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 break;
391 skb->vlan_tci = 0;
392 }
393
394 status = ops->ndo_start_xmit(skb, dev);
395 if (status == NETDEV_TX_OK)
396 txq_trans_update(txq);
397 }
398 __netif_tx_unlock(txq);
399
400 if (status == NETDEV_TX_OK)
401 break;
402
403 }
404
405 /* tickle device maybe there is some cleanup */
406 netpoll_poll_dev(np->dev);
407
408 udelay(USEC_PER_POLL);
409 }
410
411 WARN_ONCE(!irqs_disabled(),
412 "netpoll_send_skb_on_dev(): %s enabled interrupts in poll (%pF)\n",
413 dev->name, ops->ndo_start_xmit);
414
415 }
416
417 if (status != NETDEV_TX_OK) {
418 skb_queue_tail(&npinfo->txq, skb);
419 schedule_delayed_work(&npinfo->tx_work,0);
420 }
421 }
422 EXPORT_SYMBOL(netpoll_send_skb_on_dev);
423
424 void netpoll_send_udp(struct netpoll *np, const char *msg, int len)
425 {
426 int total_len, ip_len, udp_len;
427 struct sk_buff *skb;
428 struct udphdr *udph;
429 struct iphdr *iph;
430 struct ethhdr *eth;
431 static atomic_t ip_ident;
432 struct ipv6hdr *ip6h;
433
434 udp_len = len + sizeof(*udph);
435 if (np->ipv6)
436 ip_len = udp_len + sizeof(*ip6h);
437 else
438 ip_len = udp_len + sizeof(*iph);
439
440 total_len = ip_len + LL_RESERVED_SPACE(np->dev);
441
442 skb = find_skb(np, total_len + np->dev->needed_tailroom,
443 total_len - len);
444 if (!skb)
445 return;
446
447 skb_copy_to_linear_data(skb, msg, len);
448 skb_put(skb, len);
449
450 skb_push(skb, sizeof(*udph));
451 skb_reset_transport_header(skb);
452 udph = udp_hdr(skb);
453 udph->source = htons(np->local_port);
454 udph->dest = htons(np->remote_port);
455 udph->len = htons(udp_len);
456
457 if (np->ipv6) {
458 udph->check = 0;
459 udph->check = csum_ipv6_magic(&np->local_ip.in6,
460 &np->remote_ip.in6,
461 udp_len, IPPROTO_UDP,
462 csum_partial(udph, udp_len, 0));
463 if (udph->check == 0)
464 udph->check = CSUM_MANGLED_0;
465
466 skb_push(skb, sizeof(*ip6h));
467 skb_reset_network_header(skb);
468 ip6h = ipv6_hdr(skb);
469
470 /* ip6h->version = 6; ip6h->priority = 0; */
471 put_unaligned(0x60, (unsigned char *)ip6h);
472 ip6h->flow_lbl[0] = 0;
473 ip6h->flow_lbl[1] = 0;
474 ip6h->flow_lbl[2] = 0;
475
476 ip6h->payload_len = htons(sizeof(struct udphdr) + len);
477 ip6h->nexthdr = IPPROTO_UDP;
478 ip6h->hop_limit = 32;
479 ip6h->saddr = np->local_ip.in6;
480 ip6h->daddr = np->remote_ip.in6;
481
482 eth = (struct ethhdr *) skb_push(skb, ETH_HLEN);
483 skb_reset_mac_header(skb);
484 skb->protocol = eth->h_proto = htons(ETH_P_IPV6);
485 } else {
486 udph->check = 0;
487 udph->check = csum_tcpudp_magic(np->local_ip.ip,
488 np->remote_ip.ip,
489 udp_len, IPPROTO_UDP,
490 csum_partial(udph, udp_len, 0));
491 if (udph->check == 0)
492 udph->check = CSUM_MANGLED_0;
493
494 skb_push(skb, sizeof(*iph));
495 skb_reset_network_header(skb);
496 iph = ip_hdr(skb);
497
498 /* iph->version = 4; iph->ihl = 5; */
499 put_unaligned(0x45, (unsigned char *)iph);
500 iph->tos = 0;
501 put_unaligned(htons(ip_len), &(iph->tot_len));
502 iph->id = htons(atomic_inc_return(&ip_ident));
503 iph->frag_off = 0;
504 iph->ttl = 64;
505 iph->protocol = IPPROTO_UDP;
506 iph->check = 0;
507 put_unaligned(np->local_ip.ip, &(iph->saddr));
508 put_unaligned(np->remote_ip.ip, &(iph->daddr));
509 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl);
510
511 eth = (struct ethhdr *) skb_push(skb, ETH_HLEN);
512 skb_reset_mac_header(skb);
513 skb->protocol = eth->h_proto = htons(ETH_P_IP);
514 }
515
516 memcpy(eth->h_source, np->dev->dev_addr, ETH_ALEN);
517 memcpy(eth->h_dest, np->remote_mac, ETH_ALEN);
518
519 skb->dev = np->dev;
520
521 netpoll_send_skb(np, skb);
522 }
523 EXPORT_SYMBOL(netpoll_send_udp);
524
525 static void netpoll_neigh_reply(struct sk_buff *skb, struct netpoll_info *npinfo)
526 {
527 int size, type = ARPOP_REPLY;
528 __be32 sip, tip;
529 unsigned char *sha;
530 struct sk_buff *send_skb;
531 struct netpoll *np, *tmp;
532 unsigned long flags;
533 int hlen, tlen;
534 int hits = 0, proto;
535
536 if (list_empty(&npinfo->rx_np))
537 return;
538
539 /* Before checking the packet, we do some early
540 inspection whether this is interesting at all */
541 spin_lock_irqsave(&npinfo->rx_lock, flags);
542 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) {
543 if (np->dev == skb->dev)
544 hits++;
545 }
546 spin_unlock_irqrestore(&npinfo->rx_lock, flags);
547
548 /* No netpoll struct is using this dev */
549 if (!hits)
550 return;
551
552 proto = ntohs(eth_hdr(skb)->h_proto);
553 if (proto == ETH_P_IP) {
554 struct arphdr *arp;
555 unsigned char *arp_ptr;
556 /* No arp on this interface */
557 if (skb->dev->flags & IFF_NOARP)
558 return;
559
560 if (!pskb_may_pull(skb, arp_hdr_len(skb->dev)))
561 return;
562
563 skb_reset_network_header(skb);
564 skb_reset_transport_header(skb);
565 arp = arp_hdr(skb);
566
567 if ((arp->ar_hrd != htons(ARPHRD_ETHER) &&
568 arp->ar_hrd != htons(ARPHRD_IEEE802)) ||
569 arp->ar_pro != htons(ETH_P_IP) ||
570 arp->ar_op != htons(ARPOP_REQUEST))
571 return;
572
573 arp_ptr = (unsigned char *)(arp+1);
574 /* save the location of the src hw addr */
575 sha = arp_ptr;
576 arp_ptr += skb->dev->addr_len;
577 memcpy(&sip, arp_ptr, 4);
578 arp_ptr += 4;
579 /* If we actually cared about dst hw addr,
580 it would get copied here */
581 arp_ptr += skb->dev->addr_len;
582 memcpy(&tip, arp_ptr, 4);
583
584 /* Should we ignore arp? */
585 if (ipv4_is_loopback(tip) || ipv4_is_multicast(tip))
586 return;
587
588 size = arp_hdr_len(skb->dev);
589
590 spin_lock_irqsave(&npinfo->rx_lock, flags);
591 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) {
592 if (tip != np->local_ip.ip)
593 continue;
594
595 hlen = LL_RESERVED_SPACE(np->dev);
596 tlen = np->dev->needed_tailroom;
597 send_skb = find_skb(np, size + hlen + tlen, hlen);
598 if (!send_skb)
599 continue;
600
601 skb_reset_network_header(send_skb);
602 arp = (struct arphdr *) skb_put(send_skb, size);
603 send_skb->dev = skb->dev;
604 send_skb->protocol = htons(ETH_P_ARP);
605
606 /* Fill the device header for the ARP frame */
607 if (dev_hard_header(send_skb, skb->dev, ETH_P_ARP,
608 sha, np->dev->dev_addr,
609 send_skb->len) < 0) {
610 kfree_skb(send_skb);
611 continue;
612 }
613
614 /*
615 * Fill out the arp protocol part.
616 *
617 * we only support ethernet device type,
618 * which (according to RFC 1390) should
619 * always equal 1 (Ethernet).
620 */
621
622 arp->ar_hrd = htons(np->dev->type);
623 arp->ar_pro = htons(ETH_P_IP);
624 arp->ar_hln = np->dev->addr_len;
625 arp->ar_pln = 4;
626 arp->ar_op = htons(type);
627
628 arp_ptr = (unsigned char *)(arp + 1);
629 memcpy(arp_ptr, np->dev->dev_addr, np->dev->addr_len);
630 arp_ptr += np->dev->addr_len;
631 memcpy(arp_ptr, &tip, 4);
632 arp_ptr += 4;
633 memcpy(arp_ptr, sha, np->dev->addr_len);
634 arp_ptr += np->dev->addr_len;
635 memcpy(arp_ptr, &sip, 4);
636
637 netpoll_send_skb(np, send_skb);
638
639 /* If there are several rx_hooks for the same address,
640 we're fine by sending a single reply */
641 break;
642 }
643 spin_unlock_irqrestore(&npinfo->rx_lock, flags);
644 } else if( proto == ETH_P_IPV6) {
645 #if IS_ENABLED(CONFIG_IPV6)
646 struct nd_msg *msg;
647 u8 *lladdr = NULL;
648 struct ipv6hdr *hdr;
649 struct icmp6hdr *icmp6h;
650 const struct in6_addr *saddr;
651 const struct in6_addr *daddr;
652 struct inet6_dev *in6_dev = NULL;
653 struct in6_addr *target;
654
655 in6_dev = in6_dev_get(skb->dev);
656 if (!in6_dev || !in6_dev->cnf.accept_ra)
657 return;
658
659 if (!pskb_may_pull(skb, skb->len))
660 return;
661
662 msg = (struct nd_msg *)skb_transport_header(skb);
663
664 __skb_push(skb, skb->data - skb_transport_header(skb));
665
666 if (ipv6_hdr(skb)->hop_limit != 255)
667 return;
668 if (msg->icmph.icmp6_code != 0)
669 return;
670 if (msg->icmph.icmp6_type != NDISC_NEIGHBOUR_SOLICITATION)
671 return;
672
673 saddr = &ipv6_hdr(skb)->saddr;
674 daddr = &ipv6_hdr(skb)->daddr;
675
676 size = sizeof(struct icmp6hdr) + sizeof(struct in6_addr);
677
678 spin_lock_irqsave(&npinfo->rx_lock, flags);
679 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) {
680 if (!ipv6_addr_equal(daddr, &np->local_ip.in6))
681 continue;
682
683 hlen = LL_RESERVED_SPACE(np->dev);
684 tlen = np->dev->needed_tailroom;
685 send_skb = find_skb(np, size + hlen + tlen, hlen);
686 if (!send_skb)
687 continue;
688
689 send_skb->protocol = htons(ETH_P_IPV6);
690 send_skb->dev = skb->dev;
691
692 skb_reset_network_header(send_skb);
693 hdr = (struct ipv6hdr *) skb_put(send_skb, sizeof(struct ipv6hdr));
694 *(__be32*)hdr = htonl(0x60000000);
695 hdr->payload_len = htons(size);
696 hdr->nexthdr = IPPROTO_ICMPV6;
697 hdr->hop_limit = 255;
698 hdr->saddr = *saddr;
699 hdr->daddr = *daddr;
700
701 icmp6h = (struct icmp6hdr *) skb_put(send_skb, sizeof(struct icmp6hdr));
702 icmp6h->icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT;
703 icmp6h->icmp6_router = 0;
704 icmp6h->icmp6_solicited = 1;
705
706 target = (struct in6_addr *) skb_put(send_skb, sizeof(struct in6_addr));
707 *target = msg->target;
708 icmp6h->icmp6_cksum = csum_ipv6_magic(saddr, daddr, size,
709 IPPROTO_ICMPV6,
710 csum_partial(icmp6h,
711 size, 0));
712
713 if (dev_hard_header(send_skb, skb->dev, ETH_P_IPV6,
714 lladdr, np->dev->dev_addr,
715 send_skb->len) < 0) {
716 kfree_skb(send_skb);
717 continue;
718 }
719
720 netpoll_send_skb(np, send_skb);
721
722 /* If there are several rx_hooks for the same address,
723 we're fine by sending a single reply */
724 break;
725 }
726 spin_unlock_irqrestore(&npinfo->rx_lock, flags);
727 #endif
728 }
729 }
730
731 static bool pkt_is_ns(struct sk_buff *skb)
732 {
733 struct nd_msg *msg;
734 struct ipv6hdr *hdr;
735
736 if (skb->protocol != htons(ETH_P_ARP))
737 return false;
738 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr) + sizeof(struct nd_msg)))
739 return false;
740
741 msg = (struct nd_msg *)skb_transport_header(skb);
742 __skb_push(skb, skb->data - skb_transport_header(skb));
743 hdr = ipv6_hdr(skb);
744
745 if (hdr->nexthdr != IPPROTO_ICMPV6)
746 return false;
747 if (hdr->hop_limit != 255)
748 return false;
749 if (msg->icmph.icmp6_code != 0)
750 return false;
751 if (msg->icmph.icmp6_type != NDISC_NEIGHBOUR_SOLICITATION)
752 return false;
753
754 return true;
755 }
756
757 int __netpoll_rx(struct sk_buff *skb, struct netpoll_info *npinfo)
758 {
759 int proto, len, ulen;
760 int hits = 0;
761 const struct iphdr *iph;
762 struct udphdr *uh;
763 struct netpoll *np, *tmp;
764
765 if (list_empty(&npinfo->rx_np))
766 goto out;
767
768 if (skb->dev->type != ARPHRD_ETHER)
769 goto out;
770
771 /* check if netpoll clients need ARP */
772 if (skb->protocol == htons(ETH_P_ARP) && atomic_read(&trapped)) {
773 skb_queue_tail(&npinfo->neigh_tx, skb);
774 return 1;
775 } else if (pkt_is_ns(skb) && atomic_read(&trapped)) {
776 skb_queue_tail(&npinfo->neigh_tx, skb);
777 return 1;
778 }
779
780 if (skb->protocol == cpu_to_be16(ETH_P_8021Q)) {
781 skb = vlan_untag(skb);
782 if (unlikely(!skb))
783 goto out;
784 }
785
786 proto = ntohs(eth_hdr(skb)->h_proto);
787 if (proto != ETH_P_IP && proto != ETH_P_IPV6)
788 goto out;
789 if (skb->pkt_type == PACKET_OTHERHOST)
790 goto out;
791 if (skb_shared(skb))
792 goto out;
793
794 if (proto == ETH_P_IP) {
795 if (!pskb_may_pull(skb, sizeof(struct iphdr)))
796 goto out;
797 iph = (struct iphdr *)skb->data;
798 if (iph->ihl < 5 || iph->version != 4)
799 goto out;
800 if (!pskb_may_pull(skb, iph->ihl*4))
801 goto out;
802 iph = (struct iphdr *)skb->data;
803 if (ip_fast_csum((u8 *)iph, iph->ihl) != 0)
804 goto out;
805
806 len = ntohs(iph->tot_len);
807 if (skb->len < len || len < iph->ihl*4)
808 goto out;
809
810 /*
811 * Our transport medium may have padded the buffer out.
812 * Now We trim to the true length of the frame.
813 */
814 if (pskb_trim_rcsum(skb, len))
815 goto out;
816
817 iph = (struct iphdr *)skb->data;
818 if (iph->protocol != IPPROTO_UDP)
819 goto out;
820
821 len -= iph->ihl*4;
822 uh = (struct udphdr *)(((char *)iph) + iph->ihl*4);
823 ulen = ntohs(uh->len);
824
825 if (ulen != len)
826 goto out;
827 if (checksum_udp(skb, uh, ulen, iph->saddr, iph->daddr))
828 goto out;
829 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) {
830 if (np->local_ip.ip && np->local_ip.ip != iph->daddr)
831 continue;
832 if (np->remote_ip.ip && np->remote_ip.ip != iph->saddr)
833 continue;
834 if (np->local_port && np->local_port != ntohs(uh->dest))
835 continue;
836
837 np->rx_hook(np, ntohs(uh->source),
838 (char *)(uh+1),
839 ulen - sizeof(struct udphdr));
840 hits++;
841 }
842 } else {
843 #if IS_ENABLED(CONFIG_IPV6)
844 const struct ipv6hdr *ip6h;
845
846 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
847 goto out;
848 ip6h = (struct ipv6hdr *)skb->data;
849 if (ip6h->version != 6)
850 goto out;
851 len = ntohs(ip6h->payload_len);
852 if (!len)
853 goto out;
854 if (len + sizeof(struct ipv6hdr) > skb->len)
855 goto out;
856 if (pskb_trim_rcsum(skb, len + sizeof(struct ipv6hdr)))
857 goto out;
858 ip6h = ipv6_hdr(skb);
859 if (!pskb_may_pull(skb, sizeof(struct udphdr)))
860 goto out;
861 uh = udp_hdr(skb);
862 ulen = ntohs(uh->len);
863 if (ulen != skb->len)
864 goto out;
865 if (udp6_csum_init(skb, uh, IPPROTO_UDP))
866 goto out;
867 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) {
868 if (!ipv6_addr_equal(&np->local_ip.in6, &ip6h->daddr))
869 continue;
870 if (!ipv6_addr_equal(&np->remote_ip.in6, &ip6h->saddr))
871 continue;
872 if (np->local_port && np->local_port != ntohs(uh->dest))
873 continue;
874
875 np->rx_hook(np, ntohs(uh->source),
876 (char *)(uh+1),
877 ulen - sizeof(struct udphdr));
878 hits++;
879 }
880 #endif
881 }
882
883 if (!hits)
884 goto out;
885
886 kfree_skb(skb);
887 return 1;
888
889 out:
890 if (atomic_read(&trapped)) {
891 kfree_skb(skb);
892 return 1;
893 }
894
895 return 0;
896 }
897
898 void netpoll_print_options(struct netpoll *np)
899 {
900 np_info(np, "local port %d\n", np->local_port);
901 if (np->ipv6)
902 np_info(np, "local IPv6 address %pI6c\n", &np->local_ip.in6);
903 else
904 np_info(np, "local IPv4 address %pI4\n", &np->local_ip.ip);
905 np_info(np, "interface '%s'\n", np->dev_name);
906 np_info(np, "remote port %d\n", np->remote_port);
907 if (np->ipv6)
908 np_info(np, "remote IPv6 address %pI6c\n", &np->remote_ip.in6);
909 else
910 np_info(np, "remote IPv4 address %pI4\n", &np->remote_ip.ip);
911 np_info(np, "remote ethernet address %pM\n", np->remote_mac);
912 }
913 EXPORT_SYMBOL(netpoll_print_options);
914
915 static int netpoll_parse_ip_addr(const char *str, union inet_addr *addr)
916 {
917 const char *end;
918
919 if (!strchr(str, ':') &&
920 in4_pton(str, -1, (void *)addr, -1, &end) > 0) {
921 if (!*end)
922 return 0;
923 }
924 if (in6_pton(str, -1, addr->in6.s6_addr, -1, &end) > 0) {
925 #if IS_ENABLED(CONFIG_IPV6)
926 if (!*end)
927 return 1;
928 #else
929 return -1;
930 #endif
931 }
932 return -1;
933 }
934
935 int netpoll_parse_options(struct netpoll *np, char *opt)
936 {
937 char *cur=opt, *delim;
938 int ipv6;
939
940 if (*cur != '@') {
941 if ((delim = strchr(cur, '@')) == NULL)
942 goto parse_failed;
943 *delim = 0;
944 if (kstrtou16(cur, 10, &np->local_port))
945 goto parse_failed;
946 cur = delim;
947 }
948 cur++;
949
950 if (*cur != '/') {
951 if ((delim = strchr(cur, '/')) == NULL)
952 goto parse_failed;
953 *delim = 0;
954 ipv6 = netpoll_parse_ip_addr(cur, &np->local_ip);
955 if (ipv6 < 0)
956 goto parse_failed;
957 else
958 np->ipv6 = (bool)ipv6;
959 cur = delim;
960 }
961 cur++;
962
963 if (*cur != ',') {
964 /* parse out dev name */
965 if ((delim = strchr(cur, ',')) == NULL)
966 goto parse_failed;
967 *delim = 0;
968 strlcpy(np->dev_name, cur, sizeof(np->dev_name));
969 cur = delim;
970 }
971 cur++;
972
973 if (*cur != '@') {
974 /* dst port */
975 if ((delim = strchr(cur, '@')) == NULL)
976 goto parse_failed;
977 *delim = 0;
978 if (*cur == ' ' || *cur == '\t')
979 np_info(np, "warning: whitespace is not allowed\n");
980 if (kstrtou16(cur, 10, &np->remote_port))
981 goto parse_failed;
982 cur = delim;
983 }
984 cur++;
985
986 /* dst ip */
987 if ((delim = strchr(cur, '/')) == NULL)
988 goto parse_failed;
989 *delim = 0;
990 ipv6 = netpoll_parse_ip_addr(cur, &np->remote_ip);
991 if (ipv6 < 0)
992 goto parse_failed;
993 else if (np->ipv6 != (bool)ipv6)
994 goto parse_failed;
995 else
996 np->ipv6 = (bool)ipv6;
997 cur = delim + 1;
998
999 if (*cur != 0) {
1000 /* MAC address */
1001 if (!mac_pton(cur, np->remote_mac))
1002 goto parse_failed;
1003 }
1004
1005 netpoll_print_options(np);
1006
1007 return 0;
1008
1009 parse_failed:
1010 np_info(np, "couldn't parse config at '%s'!\n", cur);
1011 return -1;
1012 }
1013 EXPORT_SYMBOL(netpoll_parse_options);
1014
1015 int __netpoll_setup(struct netpoll *np, struct net_device *ndev, gfp_t gfp)
1016 {
1017 struct netpoll_info *npinfo;
1018 const struct net_device_ops *ops;
1019 unsigned long flags;
1020 int err;
1021
1022 np->dev = ndev;
1023 strlcpy(np->dev_name, ndev->name, IFNAMSIZ);
1024 INIT_WORK(&np->cleanup_work, netpoll_async_cleanup);
1025
1026 if ((ndev->priv_flags & IFF_DISABLE_NETPOLL) ||
1027 !ndev->netdev_ops->ndo_poll_controller) {
1028 np_err(np, "%s doesn't support polling, aborting\n",
1029 np->dev_name);
1030 err = -ENOTSUPP;
1031 goto out;
1032 }
1033
1034 if (!ndev->npinfo) {
1035 npinfo = kmalloc(sizeof(*npinfo), gfp);
1036 if (!npinfo) {
1037 err = -ENOMEM;
1038 goto out;
1039 }
1040
1041 npinfo->rx_flags = 0;
1042 INIT_LIST_HEAD(&npinfo->rx_np);
1043
1044 spin_lock_init(&npinfo->rx_lock);
1045 sema_init(&npinfo->dev_lock, 1);
1046 skb_queue_head_init(&npinfo->neigh_tx);
1047 skb_queue_head_init(&npinfo->txq);
1048 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process);
1049
1050 atomic_set(&npinfo->refcnt, 1);
1051
1052 ops = np->dev->netdev_ops;
1053 if (ops->ndo_netpoll_setup) {
1054 err = ops->ndo_netpoll_setup(ndev, npinfo, gfp);
1055 if (err)
1056 goto free_npinfo;
1057 }
1058 } else {
1059 npinfo = rtnl_dereference(ndev->npinfo);
1060 atomic_inc(&npinfo->refcnt);
1061 }
1062
1063 npinfo->netpoll = np;
1064
1065 if (np->rx_hook) {
1066 spin_lock_irqsave(&npinfo->rx_lock, flags);
1067 npinfo->rx_flags |= NETPOLL_RX_ENABLED;
1068 list_add_tail(&np->rx, &npinfo->rx_np);
1069 spin_unlock_irqrestore(&npinfo->rx_lock, flags);
1070 }
1071
1072 /* last thing to do is link it to the net device structure */
1073 rcu_assign_pointer(ndev->npinfo, npinfo);
1074
1075 return 0;
1076
1077 free_npinfo:
1078 kfree(npinfo);
1079 out:
1080 return err;
1081 }
1082 EXPORT_SYMBOL_GPL(__netpoll_setup);
1083
1084 int netpoll_setup(struct netpoll *np)
1085 {
1086 struct net_device *ndev = NULL;
1087 struct in_device *in_dev;
1088 int err;
1089
1090 rtnl_lock();
1091 if (np->dev_name) {
1092 struct net *net = current->nsproxy->net_ns;
1093 ndev = __dev_get_by_name(net, np->dev_name);
1094 }
1095 if (!ndev) {
1096 np_err(np, "%s doesn't exist, aborting\n", np->dev_name);
1097 err = -ENODEV;
1098 goto unlock;
1099 }
1100 dev_hold(ndev);
1101
1102 if (netdev_master_upper_dev_get(ndev)) {
1103 np_err(np, "%s is a slave device, aborting\n", np->dev_name);
1104 err = -EBUSY;
1105 goto put;
1106 }
1107
1108 if (!netif_running(ndev)) {
1109 unsigned long atmost, atleast;
1110
1111 np_info(np, "device %s not up yet, forcing it\n", np->dev_name);
1112
1113 err = dev_open(ndev);
1114
1115 if (err) {
1116 np_err(np, "failed to open %s\n", ndev->name);
1117 goto put;
1118 }
1119
1120 rtnl_unlock();
1121 atleast = jiffies + HZ/10;
1122 atmost = jiffies + carrier_timeout * HZ;
1123 while (!netif_carrier_ok(ndev)) {
1124 if (time_after(jiffies, atmost)) {
1125 np_notice(np, "timeout waiting for carrier\n");
1126 break;
1127 }
1128 msleep(1);
1129 }
1130
1131 /* If carrier appears to come up instantly, we don't
1132 * trust it and pause so that we don't pump all our
1133 * queued console messages into the bitbucket.
1134 */
1135
1136 if (time_before(jiffies, atleast)) {
1137 np_notice(np, "carrier detect appears untrustworthy, waiting 4 seconds\n");
1138 msleep(4000);
1139 }
1140 rtnl_lock();
1141 }
1142
1143 if (!np->local_ip.ip) {
1144 if (!np->ipv6) {
1145 in_dev = __in_dev_get_rtnl(ndev);
1146
1147 if (!in_dev || !in_dev->ifa_list) {
1148 np_err(np, "no IP address for %s, aborting\n",
1149 np->dev_name);
1150 err = -EDESTADDRREQ;
1151 goto put;
1152 }
1153
1154 np->local_ip.ip = in_dev->ifa_list->ifa_local;
1155 np_info(np, "local IP %pI4\n", &np->local_ip.ip);
1156 } else {
1157 #if IS_ENABLED(CONFIG_IPV6)
1158 struct inet6_dev *idev;
1159
1160 err = -EDESTADDRREQ;
1161 idev = __in6_dev_get(ndev);
1162 if (idev) {
1163 struct inet6_ifaddr *ifp;
1164
1165 read_lock_bh(&idev->lock);
1166 list_for_each_entry(ifp, &idev->addr_list, if_list) {
1167 if (ipv6_addr_type(&ifp->addr) & IPV6_ADDR_LINKLOCAL)
1168 continue;
1169 np->local_ip.in6 = ifp->addr;
1170 err = 0;
1171 break;
1172 }
1173 read_unlock_bh(&idev->lock);
1174 }
1175 if (err) {
1176 np_err(np, "no IPv6 address for %s, aborting\n",
1177 np->dev_name);
1178 goto put;
1179 } else
1180 np_info(np, "local IPv6 %pI6c\n", &np->local_ip.in6);
1181 #else
1182 np_err(np, "IPv6 is not supported %s, aborting\n",
1183 np->dev_name);
1184 err = -EINVAL;
1185 goto put;
1186 #endif
1187 }
1188 }
1189
1190 /* fill up the skb queue */
1191 refill_skbs();
1192
1193 err = __netpoll_setup(np, ndev, GFP_KERNEL);
1194 if (err)
1195 goto put;
1196
1197 rtnl_unlock();
1198 return 0;
1199
1200 put:
1201 dev_put(ndev);
1202 unlock:
1203 rtnl_unlock();
1204 return err;
1205 }
1206 EXPORT_SYMBOL(netpoll_setup);
1207
1208 static int __init netpoll_init(void)
1209 {
1210 skb_queue_head_init(&skb_pool);
1211 return 0;
1212 }
1213 core_initcall(netpoll_init);
1214
1215 static void rcu_cleanup_netpoll_info(struct rcu_head *rcu_head)
1216 {
1217 struct netpoll_info *npinfo =
1218 container_of(rcu_head, struct netpoll_info, rcu);
1219
1220 skb_queue_purge(&npinfo->neigh_tx);
1221 skb_queue_purge(&npinfo->txq);
1222
1223 /* we can't call cancel_delayed_work_sync here, as we are in softirq */
1224 cancel_delayed_work(&npinfo->tx_work);
1225
1226 /* clean after last, unfinished work */
1227 __skb_queue_purge(&npinfo->txq);
1228 /* now cancel it again */
1229 cancel_delayed_work(&npinfo->tx_work);
1230 kfree(npinfo);
1231 }
1232
1233 void __netpoll_cleanup(struct netpoll *np)
1234 {
1235 struct netpoll_info *npinfo;
1236 unsigned long flags;
1237
1238 /* rtnl_dereference would be preferable here but
1239 * rcu_cleanup_netpoll path can put us in here safely without
1240 * holding the rtnl, so plain rcu_dereference it is
1241 */
1242 npinfo = rtnl_dereference(np->dev->npinfo);
1243 if (!npinfo)
1244 return;
1245
1246 if (!list_empty(&npinfo->rx_np)) {
1247 spin_lock_irqsave(&npinfo->rx_lock, flags);
1248 list_del(&np->rx);
1249 if (list_empty(&npinfo->rx_np))
1250 npinfo->rx_flags &= ~NETPOLL_RX_ENABLED;
1251 spin_unlock_irqrestore(&npinfo->rx_lock, flags);
1252 }
1253
1254 synchronize_srcu(&netpoll_srcu);
1255
1256 if (atomic_dec_and_test(&npinfo->refcnt)) {
1257 const struct net_device_ops *ops;
1258
1259 ops = np->dev->netdev_ops;
1260 if (ops->ndo_netpoll_cleanup)
1261 ops->ndo_netpoll_cleanup(np->dev);
1262
1263 rcu_assign_pointer(np->dev->npinfo, NULL);
1264 call_rcu_bh(&npinfo->rcu, rcu_cleanup_netpoll_info);
1265 }
1266 }
1267 EXPORT_SYMBOL_GPL(__netpoll_cleanup);
1268
1269 static void netpoll_async_cleanup(struct work_struct *work)
1270 {
1271 struct netpoll *np = container_of(work, struct netpoll, cleanup_work);
1272
1273 rtnl_lock();
1274 __netpoll_cleanup(np);
1275 rtnl_unlock();
1276 kfree(np);
1277 }
1278
1279 void __netpoll_free_async(struct netpoll *np)
1280 {
1281 schedule_work(&np->cleanup_work);
1282 }
1283 EXPORT_SYMBOL_GPL(__netpoll_free_async);
1284
1285 void netpoll_cleanup(struct netpoll *np)
1286 {
1287 if (!np->dev)
1288 return;
1289
1290 rtnl_lock();
1291 __netpoll_cleanup(np);
1292 rtnl_unlock();
1293
1294 dev_put(np->dev);
1295 np->dev = NULL;
1296 }
1297 EXPORT_SYMBOL(netpoll_cleanup);
1298
1299 int netpoll_trap(void)
1300 {
1301 return atomic_read(&trapped);
1302 }
1303 EXPORT_SYMBOL(netpoll_trap);
1304
1305 void netpoll_set_trap(int trap)
1306 {
1307 if (trap)
1308 atomic_inc(&trapped);
1309 else
1310 atomic_dec(&trapped);
1311 }
1312 EXPORT_SYMBOL(netpoll_set_trap);
Linus' kernel tree