?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
Merge tag 'gpio-v3.13-3' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw...
[linux-2.6.git] / net / core / netpoll.c
blob8f971990677cd48026f651b2dba01d01190bfff6
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_ARP) {
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_skb_hooks for the same
640 * address we're fine by sending a single reply
641 */
642 break;
643 }
644 spin_unlock_irqrestore(&npinfo->rx_lock, flags);
645 } else if( proto == ETH_P_IPV6) {
646 #if IS_ENABLED(CONFIG_IPV6)
647 struct nd_msg *msg;
648 u8 *lladdr = NULL;
649 struct ipv6hdr *hdr;
650 struct icmp6hdr *icmp6h;
651 const struct in6_addr *saddr;
652 const struct in6_addr *daddr;
653 struct inet6_dev *in6_dev = NULL;
654 struct in6_addr *target;
655
656 in6_dev = in6_dev_get(skb->dev);
657 if (!in6_dev || !in6_dev->cnf.accept_ra)
658 return;
659
660 if (!pskb_may_pull(skb, skb->len))
661 return;
662
663 msg = (struct nd_msg *)skb_transport_header(skb);
664
665 __skb_push(skb, skb->data - skb_transport_header(skb));
666
667 if (ipv6_hdr(skb)->hop_limit != 255)
668 return;
669 if (msg->icmph.icmp6_code != 0)
670 return;
671 if (msg->icmph.icmp6_type != NDISC_NEIGHBOUR_SOLICITATION)
672 return;
673
674 saddr = &ipv6_hdr(skb)->saddr;
675 daddr = &ipv6_hdr(skb)->daddr;
676
677 size = sizeof(struct icmp6hdr) + sizeof(struct in6_addr);
678
679 spin_lock_irqsave(&npinfo->rx_lock, flags);
680 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) {
681 if (!ipv6_addr_equal(daddr, &np->local_ip.in6))
682 continue;
683
684 hlen = LL_RESERVED_SPACE(np->dev);
685 tlen = np->dev->needed_tailroom;
686 send_skb = find_skb(np, size + hlen + tlen, hlen);
687 if (!send_skb)
688 continue;
689
690 send_skb->protocol = htons(ETH_P_IPV6);
691 send_skb->dev = skb->dev;
692
693 skb_reset_network_header(send_skb);
694 hdr = (struct ipv6hdr *) skb_put(send_skb, sizeof(struct ipv6hdr));
695 *(__be32*)hdr = htonl(0x60000000);
696 hdr->payload_len = htons(size);
697 hdr->nexthdr = IPPROTO_ICMPV6;
698 hdr->hop_limit = 255;
699 hdr->saddr = *saddr;
700 hdr->daddr = *daddr;
701
702 icmp6h = (struct icmp6hdr *) skb_put(send_skb, sizeof(struct icmp6hdr));
703 icmp6h->icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT;
704 icmp6h->icmp6_router = 0;
705 icmp6h->icmp6_solicited = 1;
706
707 target = (struct in6_addr *) skb_put(send_skb, sizeof(struct in6_addr));
708 *target = msg->target;
709 icmp6h->icmp6_cksum = csum_ipv6_magic(saddr, daddr, size,
710 IPPROTO_ICMPV6,
711 csum_partial(icmp6h,
712 size, 0));
713
714 if (dev_hard_header(send_skb, skb->dev, ETH_P_IPV6,
715 lladdr, np->dev->dev_addr,
716 send_skb->len) < 0) {
717 kfree_skb(send_skb);
718 continue;
719 }
720
721 netpoll_send_skb(np, send_skb);
722
723 /* If there are several rx_skb_hooks for the same
724 * address, we're fine by sending a single reply
725 */
726 break;
727 }
728 spin_unlock_irqrestore(&npinfo->rx_lock, flags);
729 #endif
730 }
731 }
732
733 static bool pkt_is_ns(struct sk_buff *skb)
734 {
735 struct nd_msg *msg;
736 struct ipv6hdr *hdr;
737
738 if (skb->protocol != htons(ETH_P_ARP))
739 return false;
740 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr) + sizeof(struct nd_msg)))
741 return false;
742
743 msg = (struct nd_msg *)skb_transport_header(skb);
744 __skb_push(skb, skb->data - skb_transport_header(skb));
745 hdr = ipv6_hdr(skb);
746
747 if (hdr->nexthdr != IPPROTO_ICMPV6)
748 return false;
749 if (hdr->hop_limit != 255)
750 return false;
751 if (msg->icmph.icmp6_code != 0)
752 return false;
753 if (msg->icmph.icmp6_type != NDISC_NEIGHBOUR_SOLICITATION)
754 return false;
755
756 return true;
757 }
758
759 int __netpoll_rx(struct sk_buff *skb, struct netpoll_info *npinfo)
760 {
761 int proto, len, ulen, data_len;
762 int hits = 0, offset;
763 const struct iphdr *iph;
764 struct udphdr *uh;
765 struct netpoll *np, *tmp;
766 uint16_t source;
767
768 if (list_empty(&npinfo->rx_np))
769 goto out;
770
771 if (skb->dev->type != ARPHRD_ETHER)
772 goto out;
773
774 /* check if netpoll clients need ARP */
775 if (skb->protocol == htons(ETH_P_ARP) && atomic_read(&trapped)) {
776 skb_queue_tail(&npinfo->neigh_tx, skb);
777 return 1;
778 } else if (pkt_is_ns(skb) && atomic_read(&trapped)) {
779 skb_queue_tail(&npinfo->neigh_tx, skb);
780 return 1;
781 }
782
783 if (skb->protocol == cpu_to_be16(ETH_P_8021Q)) {
784 skb = vlan_untag(skb);
785 if (unlikely(!skb))
786 goto out;
787 }
788
789 proto = ntohs(eth_hdr(skb)->h_proto);
790 if (proto != ETH_P_IP && proto != ETH_P_IPV6)
791 goto out;
792 if (skb->pkt_type == PACKET_OTHERHOST)
793 goto out;
794 if (skb_shared(skb))
795 goto out;
796
797 if (proto == ETH_P_IP) {
798 if (!pskb_may_pull(skb, sizeof(struct iphdr)))
799 goto out;
800 iph = (struct iphdr *)skb->data;
801 if (iph->ihl < 5 || iph->version != 4)
802 goto out;
803 if (!pskb_may_pull(skb, iph->ihl*4))
804 goto out;
805 iph = (struct iphdr *)skb->data;
806 if (ip_fast_csum((u8 *)iph, iph->ihl) != 0)
807 goto out;
808
809 len = ntohs(iph->tot_len);
810 if (skb->len < len || len < iph->ihl*4)
811 goto out;
812
813 /*
814 * Our transport medium may have padded the buffer out.
815 * Now We trim to the true length of the frame.
816 */
817 if (pskb_trim_rcsum(skb, len))
818 goto out;
819
820 iph = (struct iphdr *)skb->data;
821 if (iph->protocol != IPPROTO_UDP)
822 goto out;
823
824 len -= iph->ihl*4;
825 uh = (struct udphdr *)(((char *)iph) + iph->ihl*4);
826 offset = (unsigned char *)(uh + 1) - skb->data;
827 ulen = ntohs(uh->len);
828 data_len = skb->len - offset;
829 source = ntohs(uh->source);
830
831 if (ulen != len)
832 goto out;
833 if (checksum_udp(skb, uh, ulen, iph->saddr, iph->daddr))
834 goto out;
835 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) {
836 if (np->local_ip.ip && np->local_ip.ip != iph->daddr)
837 continue;
838 if (np->remote_ip.ip && np->remote_ip.ip != iph->saddr)
839 continue;
840 if (np->local_port && np->local_port != ntohs(uh->dest))
841 continue;
842
843 np->rx_skb_hook(np, source, skb, offset, data_len);
844 hits++;
845 }
846 } else {
847 #if IS_ENABLED(CONFIG_IPV6)
848 const struct ipv6hdr *ip6h;
849
850 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
851 goto out;
852 ip6h = (struct ipv6hdr *)skb->data;
853 if (ip6h->version != 6)
854 goto out;
855 len = ntohs(ip6h->payload_len);
856 if (!len)
857 goto out;
858 if (len + sizeof(struct ipv6hdr) > skb->len)
859 goto out;
860 if (pskb_trim_rcsum(skb, len + sizeof(struct ipv6hdr)))
861 goto out;
862 ip6h = ipv6_hdr(skb);
863 if (!pskb_may_pull(skb, sizeof(struct udphdr)))
864 goto out;
865 uh = udp_hdr(skb);
866 offset = (unsigned char *)(uh + 1) - skb->data;
867 ulen = ntohs(uh->len);
868 data_len = skb->len - offset;
869 source = ntohs(uh->source);
870 if (ulen != skb->len)
871 goto out;
872 if (udp6_csum_init(skb, uh, IPPROTO_UDP))
873 goto out;
874 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) {
875 if (!ipv6_addr_equal(&np->local_ip.in6, &ip6h->daddr))
876 continue;
877 if (!ipv6_addr_equal(&np->remote_ip.in6, &ip6h->saddr))
878 continue;
879 if (np->local_port && np->local_port != ntohs(uh->dest))
880 continue;
881
882 np->rx_skb_hook(np, source, skb, offset, data_len);
883 hits++;
884 }
885 #endif
886 }
887
888 if (!hits)
889 goto out;
890
891 kfree_skb(skb);
892 return 1;
893
894 out:
895 if (atomic_read(&trapped)) {
896 kfree_skb(skb);
897 return 1;
898 }
899
900 return 0;
901 }
902
903 void netpoll_print_options(struct netpoll *np)
904 {
905 np_info(np, "local port %d\n", np->local_port);
906 if (np->ipv6)
907 np_info(np, "local IPv6 address %pI6c\n", &np->local_ip.in6);
908 else
909 np_info(np, "local IPv4 address %pI4\n", &np->local_ip.ip);
910 np_info(np, "interface '%s'\n", np->dev_name);
911 np_info(np, "remote port %d\n", np->remote_port);
912 if (np->ipv6)
913 np_info(np, "remote IPv6 address %pI6c\n", &np->remote_ip.in6);
914 else
915 np_info(np, "remote IPv4 address %pI4\n", &np->remote_ip.ip);
916 np_info(np, "remote ethernet address %pM\n", np->remote_mac);
917 }
918 EXPORT_SYMBOL(netpoll_print_options);
919
920 static int netpoll_parse_ip_addr(const char *str, union inet_addr *addr)
921 {
922 const char *end;
923
924 if (!strchr(str, ':') &&
925 in4_pton(str, -1, (void *)addr, -1, &end) > 0) {
926 if (!*end)
927 return 0;
928 }
929 if (in6_pton(str, -1, addr->in6.s6_addr, -1, &end) > 0) {
930 #if IS_ENABLED(CONFIG_IPV6)
931 if (!*end)
932 return 1;
933 #else
934 return -1;
935 #endif
936 }
937 return -1;
938 }
939
940 int netpoll_parse_options(struct netpoll *np, char *opt)
941 {
942 char *cur=opt, *delim;
943 int ipv6;
944
945 if (*cur != '@') {
946 if ((delim = strchr(cur, '@')) == NULL)
947 goto parse_failed;
948 *delim = 0;
949 if (kstrtou16(cur, 10, &np->local_port))
950 goto parse_failed;
951 cur = delim;
952 }
953 cur++;
954
955 if (*cur != '/') {
956 if ((delim = strchr(cur, '/')) == NULL)
957 goto parse_failed;
958 *delim = 0;
959 ipv6 = netpoll_parse_ip_addr(cur, &np->local_ip);
960 if (ipv6 < 0)
961 goto parse_failed;
962 else
963 np->ipv6 = (bool)ipv6;
964 cur = delim;
965 }
966 cur++;
967
968 if (*cur != ',') {
969 /* parse out dev name */
970 if ((delim = strchr(cur, ',')) == NULL)
971 goto parse_failed;
972 *delim = 0;
973 strlcpy(np->dev_name, cur, sizeof(np->dev_name));
974 cur = delim;
975 }
976 cur++;
977
978 if (*cur != '@') {
979 /* dst port */
980 if ((delim = strchr(cur, '@')) == NULL)
981 goto parse_failed;
982 *delim = 0;
983 if (*cur == ' ' || *cur == '\t')
984 np_info(np, "warning: whitespace is not allowed\n");
985 if (kstrtou16(cur, 10, &np->remote_port))
986 goto parse_failed;
987 cur = delim;
988 }
989 cur++;
990
991 /* dst ip */
992 if ((delim = strchr(cur, '/')) == NULL)
993 goto parse_failed;
994 *delim = 0;
995 ipv6 = netpoll_parse_ip_addr(cur, &np->remote_ip);
996 if (ipv6 < 0)
997 goto parse_failed;
998 else if (np->ipv6 != (bool)ipv6)
999 goto parse_failed;
1000 else
1001 np->ipv6 = (bool)ipv6;
1002 cur = delim + 1;
1003
1004 if (*cur != 0) {
1005 /* MAC address */
1006 if (!mac_pton(cur, np->remote_mac))
1007 goto parse_failed;
1008 }
1009
1010 netpoll_print_options(np);
1011
1012 return 0;
1013
1014 parse_failed:
1015 np_info(np, "couldn't parse config at '%s'!\n", cur);
1016 return -1;
1017 }
1018 EXPORT_SYMBOL(netpoll_parse_options);
1019
1020 int __netpoll_setup(struct netpoll *np, struct net_device *ndev, gfp_t gfp)
1021 {
1022 struct netpoll_info *npinfo;
1023 const struct net_device_ops *ops;
1024 unsigned long flags;
1025 int err;
1026
1027 np->dev = ndev;
1028 strlcpy(np->dev_name, ndev->name, IFNAMSIZ);
1029 INIT_WORK(&np->cleanup_work, netpoll_async_cleanup);
1030
1031 if ((ndev->priv_flags & IFF_DISABLE_NETPOLL) ||
1032 !ndev->netdev_ops->ndo_poll_controller) {
1033 np_err(np, "%s doesn't support polling, aborting\n",
1034 np->dev_name);
1035 err = -ENOTSUPP;
1036 goto out;
1037 }
1038
1039 if (!ndev->npinfo) {
1040 npinfo = kmalloc(sizeof(*npinfo), gfp);
1041 if (!npinfo) {
1042 err = -ENOMEM;
1043 goto out;
1044 }
1045
1046 npinfo->rx_flags = 0;
1047 INIT_LIST_HEAD(&npinfo->rx_np);
1048
1049 spin_lock_init(&npinfo->rx_lock);
1050 sema_init(&npinfo->dev_lock, 1);
1051 skb_queue_head_init(&npinfo->neigh_tx);
1052 skb_queue_head_init(&npinfo->txq);
1053 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process);
1054
1055 atomic_set(&npinfo->refcnt, 1);
1056
1057 ops = np->dev->netdev_ops;
1058 if (ops->ndo_netpoll_setup) {
1059 err = ops->ndo_netpoll_setup(ndev, npinfo, gfp);
1060 if (err)
1061 goto free_npinfo;
1062 }
1063 } else {
1064 npinfo = rtnl_dereference(ndev->npinfo);
1065 atomic_inc(&npinfo->refcnt);
1066 }
1067
1068 npinfo->netpoll = np;
1069
1070 if (np->rx_skb_hook) {
1071 spin_lock_irqsave(&npinfo->rx_lock, flags);
1072 npinfo->rx_flags |= NETPOLL_RX_ENABLED;
1073 list_add_tail(&np->rx, &npinfo->rx_np);
1074 spin_unlock_irqrestore(&npinfo->rx_lock, flags);
1075 }
1076
1077 /* last thing to do is link it to the net device structure */
1078 rcu_assign_pointer(ndev->npinfo, npinfo);
1079
1080 return 0;
1081
1082 free_npinfo:
1083 kfree(npinfo);
1084 out:
1085 return err;
1086 }
1087 EXPORT_SYMBOL_GPL(__netpoll_setup);
1088
1089 int netpoll_setup(struct netpoll *np)
1090 {
1091 struct net_device *ndev = NULL;
1092 struct in_device *in_dev;
1093 int err;
1094
1095 rtnl_lock();
1096 if (np->dev_name) {
1097 struct net *net = current->nsproxy->net_ns;
1098 ndev = __dev_get_by_name(net, np->dev_name);
1099 }
1100 if (!ndev) {
1101 np_err(np, "%s doesn't exist, aborting\n", np->dev_name);
1102 err = -ENODEV;
1103 goto unlock;
1104 }
1105 dev_hold(ndev);
1106
1107 if (netdev_master_upper_dev_get(ndev)) {
1108 np_err(np, "%s is a slave device, aborting\n", np->dev_name);
1109 err = -EBUSY;
1110 goto put;
1111 }
1112
1113 if (!netif_running(ndev)) {
1114 unsigned long atmost, atleast;
1115
1116 np_info(np, "device %s not up yet, forcing it\n", np->dev_name);
1117
1118 err = dev_open(ndev);
1119
1120 if (err) {
1121 np_err(np, "failed to open %s\n", ndev->name);
1122 goto put;
1123 }
1124
1125 rtnl_unlock();
1126 atleast = jiffies + HZ/10;
1127 atmost = jiffies + carrier_timeout * HZ;
1128 while (!netif_carrier_ok(ndev)) {
1129 if (time_after(jiffies, atmost)) {
1130 np_notice(np, "timeout waiting for carrier\n");
1131 break;
1132 }
1133 msleep(1);
1134 }
1135
1136 /* If carrier appears to come up instantly, we don't
1137 * trust it and pause so that we don't pump all our
1138 * queued console messages into the bitbucket.
1139 */
1140
1141 if (time_before(jiffies, atleast)) {
1142 np_notice(np, "carrier detect appears untrustworthy, waiting 4 seconds\n");
1143 msleep(4000);
1144 }
1145 rtnl_lock();
1146 }
1147
1148 if (!np->local_ip.ip) {
1149 if (!np->ipv6) {
1150 in_dev = __in_dev_get_rtnl(ndev);
1151
1152 if (!in_dev || !in_dev->ifa_list) {
1153 np_err(np, "no IP address for %s, aborting\n",
1154 np->dev_name);
1155 err = -EDESTADDRREQ;
1156 goto put;
1157 }
1158
1159 np->local_ip.ip = in_dev->ifa_list->ifa_local;
1160 np_info(np, "local IP %pI4\n", &np->local_ip.ip);
1161 } else {
1162 #if IS_ENABLED(CONFIG_IPV6)
1163 struct inet6_dev *idev;
1164
1165 err = -EDESTADDRREQ;
1166 idev = __in6_dev_get(ndev);
1167 if (idev) {
1168 struct inet6_ifaddr *ifp;
1169
1170 read_lock_bh(&idev->lock);
1171 list_for_each_entry(ifp, &idev->addr_list, if_list) {
1172 if (ipv6_addr_type(&ifp->addr) & IPV6_ADDR_LINKLOCAL)
1173 continue;
1174 np->local_ip.in6 = ifp->addr;
1175 err = 0;
1176 break;
1177 }
1178 read_unlock_bh(&idev->lock);
1179 }
1180 if (err) {
1181 np_err(np, "no IPv6 address for %s, aborting\n",
1182 np->dev_name);
1183 goto put;
1184 } else
1185 np_info(np, "local IPv6 %pI6c\n", &np->local_ip.in6);
1186 #else
1187 np_err(np, "IPv6 is not supported %s, aborting\n",
1188 np->dev_name);
1189 err = -EINVAL;
1190 goto put;
1191 #endif
1192 }
1193 }
1194
1195 /* fill up the skb queue */
1196 refill_skbs();
1197
1198 err = __netpoll_setup(np, ndev, GFP_KERNEL);
1199 if (err)
1200 goto put;
1201
1202 rtnl_unlock();
1203 return 0;
1204
1205 put:
1206 dev_put(ndev);
1207 unlock:
1208 rtnl_unlock();
1209 return err;
1210 }
1211 EXPORT_SYMBOL(netpoll_setup);
1212
1213 static int __init netpoll_init(void)
1214 {
1215 skb_queue_head_init(&skb_pool);
1216 return 0;
1217 }
1218 core_initcall(netpoll_init);
1219
1220 static void rcu_cleanup_netpoll_info(struct rcu_head *rcu_head)
1221 {
1222 struct netpoll_info *npinfo =
1223 container_of(rcu_head, struct netpoll_info, rcu);
1224
1225 skb_queue_purge(&npinfo->neigh_tx);
1226 skb_queue_purge(&npinfo->txq);
1227
1228 /* we can't call cancel_delayed_work_sync here, as we are in softirq */
1229 cancel_delayed_work(&npinfo->tx_work);
1230
1231 /* clean after last, unfinished work */
1232 __skb_queue_purge(&npinfo->txq);
1233 /* now cancel it again */
1234 cancel_delayed_work(&npinfo->tx_work);
1235 kfree(npinfo);
1236 }
1237
1238 void __netpoll_cleanup(struct netpoll *np)
1239 {
1240 struct netpoll_info *npinfo;
1241 unsigned long flags;
1242
1243 /* rtnl_dereference would be preferable here but
1244 * rcu_cleanup_netpoll path can put us in here safely without
1245 * holding the rtnl, so plain rcu_dereference it is
1246 */
1247 npinfo = rtnl_dereference(np->dev->npinfo);
1248 if (!npinfo)
1249 return;
1250
1251 if (!list_empty(&npinfo->rx_np)) {
1252 spin_lock_irqsave(&npinfo->rx_lock, flags);
1253 list_del(&np->rx);
1254 if (list_empty(&npinfo->rx_np))
1255 npinfo->rx_flags &= ~NETPOLL_RX_ENABLED;
1256 spin_unlock_irqrestore(&npinfo->rx_lock, flags);
1257 }
1258
1259 synchronize_srcu(&netpoll_srcu);
1260
1261 if (atomic_dec_and_test(&npinfo->refcnt)) {
1262 const struct net_device_ops *ops;
1263
1264 ops = np->dev->netdev_ops;
1265 if (ops->ndo_netpoll_cleanup)
1266 ops->ndo_netpoll_cleanup(np->dev);
1267
1268 rcu_assign_pointer(np->dev->npinfo, NULL);
1269 call_rcu_bh(&npinfo->rcu, rcu_cleanup_netpoll_info);
1270 }
1271 }
1272 EXPORT_SYMBOL_GPL(__netpoll_cleanup);
1273
1274 static void netpoll_async_cleanup(struct work_struct *work)
1275 {
1276 struct netpoll *np = container_of(work, struct netpoll, cleanup_work);
1277
1278 rtnl_lock();
1279 __netpoll_cleanup(np);
1280 rtnl_unlock();
1281 kfree(np);
1282 }
1283
1284 void __netpoll_free_async(struct netpoll *np)
1285 {
1286 schedule_work(&np->cleanup_work);
1287 }
1288 EXPORT_SYMBOL_GPL(__netpoll_free_async);
1289
1290 void netpoll_cleanup(struct netpoll *np)
1291 {
1292 rtnl_lock();
1293 if (!np->dev)
1294 goto out;
1295 __netpoll_cleanup(np);
1296 dev_put(np->dev);
1297 np->dev = NULL;
1298 out:
1299 rtnl_unlock();
1300 }
1301 EXPORT_SYMBOL(netpoll_cleanup);
1302
1303 int netpoll_trap(void)
1304 {
1305 return atomic_read(&trapped);
1306 }
1307 EXPORT_SYMBOL(netpoll_trap);
1308
1309 void netpoll_set_trap(int trap)
1310 {
1311 if (trap)
1312 atomic_inc(&trapped);
1313 else
1314 atomic_dec(&trapped);
1315 }
1316 EXPORT_SYMBOL(netpoll_set_trap);
Linus' kernel tree