1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Common framework for low-level network console, dump, and debugger code
4 *
5 * Sep 8 2003 Matt Mackall <mpm@selenic.com>
6 *
7 * based on the netconsole code from:
8 *
9 * Copyright (C) 2001 Ingo Molnar <mingo@redhat.com>
10 * Copyright (C) 2002 Red Hat, Inc.
11 */
12
13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14
15 #include <linux/moduleparam.h>
16 #include <linux/kernel.h>
17 #include <linux/netdevice.h>
18 #include <linux/etherdevice.h>
19 #include <linux/string.h>
20 #include <linux/if_arp.h>
21 #include <linux/inetdevice.h>
22 #include <linux/inet.h>
23 #include <linux/interrupt.h>
24 #include <linux/netpoll.h>
25 #include <linux/sched.h>
26 #include <linux/delay.h>
27 #include <linux/rcupdate.h>
28 #include <linux/workqueue.h>
29 #include <linux/slab.h>
30 #include <linux/export.h>
31 #include <linux/if_vlan.h>
32 #include <net/tcp.h>
33 #include <net/udp.h>
34 #include <net/addrconf.h>
35 #include <net/ndisc.h>
36 #include <net/ip6_checksum.h>
37 #include <asm/unaligned.h>
38 #include <trace/events/napi.h>
39 #include <linux/kconfig.h>
40
41 /*
42 * We maintain a small pool of fully-sized skbs, to make sure the
43 * message gets out even in extreme OOM situations.
44 */
45
46 #define MAX_UDP_CHUNK 1460
47 #define MAX_SKBS 32
48
49 static struct sk_buff_head skb_pool;
50
51 DEFINE_STATIC_SRCU(netpoll_srcu);
52
53 #define USEC_PER_POLL 50
54
55 #define MAX_SKB_SIZE \
56 (sizeof(struct ethhdr) + \
57 sizeof(struct iphdr) + \
58 sizeof(struct udphdr) + \
59 MAX_UDP_CHUNK)
60
61 static void zap_completion_queue(void);
62
63 static unsigned int carrier_timeout = 4;
64 module_param(carrier_timeout, uint, 0644);
65
66 #define np_info(np, fmt, ...) \
67 pr_info("%s: " fmt, np->name, ##__VA_ARGS__)
68 #define np_err(np, fmt, ...) \
69 pr_err("%s: " fmt, np->name, ##__VA_ARGS__)
70 #define np_notice(np, fmt, ...) \
71 pr_notice("%s: " fmt, np->name, ##__VA_ARGS__)
72
73 static netdev_tx_t netpoll_start_xmit(struct sk_buff *skb,
74 struct net_device *dev,
75 struct netdev_queue *txq)
76 {
77 netdev_tx_t status = NETDEV_TX_OK;
78 netdev_features_t features;
79
80 features = netif_skb_features(skb);
81
82 if (skb_vlan_tag_present(skb) &&
83 !vlan_hw_offload_capable(features, skb->vlan_proto)) {
84 skb = __vlan_hwaccel_push_inside(skb);
85 if (unlikely(!skb)) {
86 /* This is actually a packet drop, but we
87 * don't want the code that calls this
88 * function to try and operate on a NULL skb.
89 */
90 goto out;
91 }
92 }
93
94 status = netdev_start_xmit(skb, dev, txq, false);
95
96 out:
97 return status;
98 }
99
100 static void queue_process(struct work_struct *work)
101 {
102 struct netpoll_info *npinfo =
103 container_of(work, struct netpoll_info, tx_work.work);
104 struct sk_buff *skb;
105 unsigned long flags;
106
107 while ((skb = skb_dequeue(&npinfo->txq))) {
108 struct net_device *dev = skb->dev;
109 struct netdev_queue *txq;
110 unsigned int q_index;
111
112 if (!netif_device_present(dev) || !netif_running(dev)) {
113 kfree_skb(skb);
114 continue;
115 }
116
117 local_irq_save(flags);
118 /* check if skb->queue_mapping is still valid */
119 q_index = skb_get_queue_mapping(skb);
120 if (unlikely(q_index >= dev->real_num_tx_queues)) {
121 q_index = q_index % dev->real_num_tx_queues;
122 skb_set_queue_mapping(skb, q_index);
123 }
124 txq = netdev_get_tx_queue(dev, q_index);
125 HARD_TX_LOCK(dev, txq, smp_processor_id());
126 if (netif_xmit_frozen_or_stopped(txq) ||
127 !dev_xmit_complete(netpoll_start_xmit(skb, dev, txq))) {
128 skb_queue_head(&npinfo->txq, skb);
129 HARD_TX_UNLOCK(dev, txq);
130 local_irq_restore(flags);
131
132 schedule_delayed_work(&npinfo->tx_work, HZ/10);
133 return;
134 }
135 HARD_TX_UNLOCK(dev, txq);
136 local_irq_restore(flags);
137 }
138 }
139
140 static int netif_local_xmit_active(struct net_device *dev)
141 {
142 int i;
143
144 for (i = 0; i < dev->num_tx_queues; i++) {
145 struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
146
147 if (READ_ONCE(txq->xmit_lock_owner) == smp_processor_id())
148 return 1;
149 }
150
151 return 0;
152 }
153
154 static void poll_one_napi(struct napi_struct *napi)
155 {
156 int work;
157
158 /* If we set this bit but see that it has already been set,
159 * that indicates that napi has been disabled and we need
160 * to abort this operation
161 */
162 if (test_and_set_bit(NAPI_STATE_NPSVC, &napi->state))
163 return;
164
165 /* We explicilty pass the polling call a budget of 0 to
166 * indicate that we are clearing the Tx path only.
167 */
168 work = napi->poll(napi, 0);
169 WARN_ONCE(work, "%pS exceeded budget in poll\n", napi->poll);
170 trace_napi_poll(napi, work, 0);
171
172 clear_bit(NAPI_STATE_NPSVC, &napi->state);
173 }
174
175 static void poll_napi(struct net_device *dev)
176 {
177 struct napi_struct *napi;
178 int cpu = smp_processor_id();
179
180 list_for_each_entry_rcu(napi, &dev->napi_list, dev_list) {
181 if (cmpxchg(&napi->poll_owner, -1, cpu) == -1) {
182 poll_one_napi(napi);
183 smp_store_release(&napi->poll_owner, -1);
184 }
185 }
186 }
187
188 void netpoll_poll_dev(struct net_device *dev)
189 {
190 struct netpoll_info *ni = rcu_dereference_bh(dev->npinfo);
191 const struct net_device_ops *ops;
192
193 /* Don't do any rx activity if the dev_lock mutex is held
194 * the dev_open/close paths use this to block netpoll activity
195 * while changing device state
196 */
197 if (!ni || down_trylock(&ni->dev_lock))
198 return;
199
200 /* Some drivers will take the same locks in poll and xmit,
201 * we can't poll if local CPU is already in xmit.
202 */
203 if (!netif_running(dev) || netif_local_xmit_active(dev)) {
204 up(&ni->dev_lock);
205 return;
206 }
207
208 ops = dev->netdev_ops;
209 if (ops->ndo_poll_controller)
210 ops->ndo_poll_controller(dev);
211
212 poll_napi(dev);
213
214 up(&ni->dev_lock);
215
216 zap_completion_queue();
217 }
218 EXPORT_SYMBOL(netpoll_poll_dev);
219
220 void netpoll_poll_disable(struct net_device *dev)
221 {
222 struct netpoll_info *ni;
223 int idx;
224 might_sleep();
225 idx = srcu_read_lock(&netpoll_srcu);
226 ni = srcu_dereference(dev->npinfo, &netpoll_srcu);
227 if (ni)
228 down(&ni->dev_lock);
229 srcu_read_unlock(&netpoll_srcu, idx);
230 }
231
232 void netpoll_poll_enable(struct net_device *dev)
233 {
234 struct netpoll_info *ni;
235 rcu_read_lock();
236 ni = rcu_dereference(dev->npinfo);
237 if (ni)
238 up(&ni->dev_lock);
239 rcu_read_unlock();
240 }
241
242 static void refill_skbs(void)
243 {
244 struct sk_buff *skb;
245 unsigned long flags;
246
247 spin_lock_irqsave(&skb_pool.lock, flags);
248 while (skb_pool.qlen < MAX_SKBS) {
249 skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC);
250 if (!skb)
251 break;
252
253 __skb_queue_tail(&skb_pool, skb);
254 }
255 spin_unlock_irqrestore(&skb_pool.lock, flags);
256 }
257
258 static void zap_completion_queue(void)
259 {
260 unsigned long flags;
261 struct softnet_data *sd = &get_cpu_var(softnet_data);
262
263 if (sd->completion_queue) {
264 struct sk_buff *clist;
265
266 local_irq_save(flags);
267 clist = sd->completion_queue;
268 sd->completion_queue = NULL;
269 local_irq_restore(flags);
270
271 while (clist != NULL) {
272 struct sk_buff *skb = clist;
273 clist = clist->next;
274 if (!skb_irq_freeable(skb)) {
275 refcount_set(&skb->users, 1);
276 dev_kfree_skb_any(skb); /* put this one back */
277 } else {
278 __kfree_skb(skb);
279 }
280 }
281 }
282
283 put_cpu_var(softnet_data);
284 }
285
286 static struct sk_buff *find_skb(struct netpoll *np, int len, int reserve)
287 {
288 int count = 0;
289 struct sk_buff *skb;
290
291 zap_completion_queue();
292 refill_skbs();
293 repeat:
294
295 skb = alloc_skb(len, GFP_ATOMIC);
296 if (!skb)
297 skb = skb_dequeue(&skb_pool);
298
299 if (!skb) {
300 if (++count < 10) {
301 netpoll_poll_dev(np->dev);
302 goto repeat;
303 }
304 return NULL;
305 }
306
307 refcount_set(&skb->users, 1);
308 skb_reserve(skb, reserve);
309 return skb;
310 }
311
312 static int netpoll_owner_active(struct net_device *dev)
313 {
314 struct napi_struct *napi;
315
316 list_for_each_entry_rcu(napi, &dev->napi_list, dev_list) {
317 if (READ_ONCE(napi->poll_owner) == smp_processor_id())
318 return 1;
319 }
320 return 0;
321 }
322
323 /* call with IRQ disabled */
324 static netdev_tx_t __netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
325 {
326 netdev_tx_t status = NETDEV_TX_BUSY;
327 struct net_device *dev;
328 unsigned long tries;
329 /* It is up to the caller to keep npinfo alive. */
330 struct netpoll_info *npinfo;
331
332 lockdep_assert_irqs_disabled();
333
334 dev = np->dev;
335 npinfo = rcu_dereference_bh(dev->npinfo);
336
337 if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) {
338 dev_kfree_skb_irq(skb);
339 return NET_XMIT_DROP;
340 }
341
342 /* don't get messages out of order, and no recursion */
343 if (skb_queue_len(&npinfo->txq) == 0 && !netpoll_owner_active(dev)) {
344 struct netdev_queue *txq;
345
346 txq = netdev_core_pick_tx(dev, skb, NULL);
347
348 /* try until next clock tick */
349 for (tries = jiffies_to_usecs(1)/USEC_PER_POLL;
350 tries > 0; --tries) {
351 if (HARD_TX_TRYLOCK(dev, txq)) {
352 if (!netif_xmit_stopped(txq))
353 status = netpoll_start_xmit(skb, dev, txq);
354
355 HARD_TX_UNLOCK(dev, txq);
356
357 if (dev_xmit_complete(status))
358 break;
359
360 }
361
362 /* tickle device maybe there is some cleanup */
363 netpoll_poll_dev(np->dev);
364
365 udelay(USEC_PER_POLL);
366 }
367
368 WARN_ONCE(!irqs_disabled(),
369 "netpoll_send_skb_on_dev(): %s enabled interrupts in poll (%pS)\n",
370 dev->name, dev->netdev_ops->ndo_start_xmit);
371
372 }
373
374 if (!dev_xmit_complete(status)) {
375 skb_queue_tail(&npinfo->txq, skb);
376 schedule_delayed_work(&npinfo->tx_work,0);
377 }
378 return NETDEV_TX_OK;
379 }
380
381 netdev_tx_t netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
382 {
383 unsigned long flags;
384 netdev_tx_t ret;
385
386 if (unlikely(!np)) {
387 dev_kfree_skb_irq(skb);
388 ret = NET_XMIT_DROP;
389 } else {
390 local_irq_save(flags);
391 ret = __netpoll_send_skb(np, skb);
392 local_irq_restore(flags);
393 }
394 return ret;
395 }
396 EXPORT_SYMBOL(netpoll_send_skb);
397
398 void netpoll_send_udp(struct netpoll *np, const char *msg, int len)
399 {
400 int total_len, ip_len, udp_len;
401 struct sk_buff *skb;
402 struct udphdr *udph;
403 struct iphdr *iph;
404 struct ethhdr *eth;
405 static atomic_t ip_ident;
406 struct ipv6hdr *ip6h;
407
408 if (!IS_ENABLED(CONFIG_PREEMPT_RT))
409 WARN_ON_ONCE(!irqs_disabled());
410
411 udp_len = len + sizeof(*udph);
412 if (np->ipv6)
413 ip_len = udp_len + sizeof(*ip6h);
414 else
415 ip_len = udp_len + sizeof(*iph);
416
417 total_len = ip_len + LL_RESERVED_SPACE(np->dev);
418
419 skb = find_skb(np, total_len + np->dev->needed_tailroom,
420 total_len - len);
421 if (!skb)
422 return;
423
424 skb_copy_to_linear_data(skb, msg, len);
425 skb_put(skb, len);
426
427 skb_push(skb, sizeof(*udph));
428 skb_reset_transport_header(skb);
429 udph = udp_hdr(skb);
430 udph->source = htons(np->local_port);
431 udph->dest = htons(np->remote_port);
432 udph->len = htons(udp_len);
433
434 if (np->ipv6) {
435 udph->check = 0;
436 udph->check = csum_ipv6_magic(&np->local_ip.in6,
437 &np->remote_ip.in6,
438 udp_len, IPPROTO_UDP,
439 csum_partial(udph, udp_len, 0));
440 if (udph->check == 0)
441 udph->check = CSUM_MANGLED_0;
442
443 skb_push(skb, sizeof(*ip6h));
444 skb_reset_network_header(skb);
445 ip6h = ipv6_hdr(skb);
446
447 /* ip6h->version = 6; ip6h->priority = 0; */
448 *(unsigned char *)ip6h = 0x60;
449 ip6h->flow_lbl[0] = 0;
450 ip6h->flow_lbl[1] = 0;
451 ip6h->flow_lbl[2] = 0;
452
453 ip6h->payload_len = htons(sizeof(struct udphdr) + len);
454 ip6h->nexthdr = IPPROTO_UDP;
455 ip6h->hop_limit = 32;
456 ip6h->saddr = np->local_ip.in6;
457 ip6h->daddr = np->remote_ip.in6;
458
459 eth = skb_push(skb, ETH_HLEN);
460 skb_reset_mac_header(skb);
461 skb->protocol = eth->h_proto = htons(ETH_P_IPV6);
462 } else {
463 udph->check = 0;
464 udph->check = csum_tcpudp_magic(np->local_ip.ip,
465 np->remote_ip.ip,
466 udp_len, IPPROTO_UDP,
467 csum_partial(udph, udp_len, 0));
468 if (udph->check == 0)
469 udph->check = CSUM_MANGLED_0;
470
471 skb_push(skb, sizeof(*iph));
472 skb_reset_network_header(skb);
473 iph = ip_hdr(skb);
474
475 /* iph->version = 4; iph->ihl = 5; */
476 *(unsigned char *)iph = 0x45;
477 iph->tos = 0;
478 put_unaligned(htons(ip_len), &(iph->tot_len));
479 iph->id = htons(atomic_inc_return(&ip_ident));
480 iph->frag_off = 0;
481 iph->ttl = 64;
482 iph->protocol = IPPROTO_UDP;
483 iph->check = 0;
484 put_unaligned(np->local_ip.ip, &(iph->saddr));
485 put_unaligned(np->remote_ip.ip, &(iph->daddr));
486 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl);
487
488 eth = skb_push(skb, ETH_HLEN);
489 skb_reset_mac_header(skb);
490 skb->protocol = eth->h_proto = htons(ETH_P_IP);
491 }
492
493 ether_addr_copy(eth->h_source, np->dev->dev_addr);
494 ether_addr_copy(eth->h_dest, np->remote_mac);
495
496 skb->dev = np->dev;
497
498 netpoll_send_skb(np, skb);
499 }
500 EXPORT_SYMBOL(netpoll_send_udp);
501
502 void netpoll_print_options(struct netpoll *np)
503 {
504 np_info(np, "local port %d\n", np->local_port);
505 if (np->ipv6)
506 np_info(np, "local IPv6 address %pI6c\n", &np->local_ip.in6);
507 else
508 np_info(np, "local IPv4 address %pI4\n", &np->local_ip.ip);
509 np_info(np, "interface '%s'\n", np->dev_name);
510 np_info(np, "remote port %d\n", np->remote_port);
511 if (np->ipv6)
512 np_info(np, "remote IPv6 address %pI6c\n", &np->remote_ip.in6);
513 else
514 np_info(np, "remote IPv4 address %pI4\n", &np->remote_ip.ip);
515 np_info(np, "remote ethernet address %pM\n", np->remote_mac);
516 }
517 EXPORT_SYMBOL(netpoll_print_options);
518
519 static int netpoll_parse_ip_addr(const char *str, union inet_addr *addr)
520 {
521 const char *end;
522
523 if (!strchr(str, ':') &&
524 in4_pton(str, -1, (void *)addr, -1, &end) > 0) {
525 if (!*end)
526 return 0;
527 }
528 if (in6_pton(str, -1, addr->in6.s6_addr, -1, &end) > 0) {
529 #if IS_ENABLED(CONFIG_IPV6)
530 if (!*end)
531 return 1;
532 #else
533 return -1;
534 #endif
535 }
536 return -1;
537 }
538
539 int netpoll_parse_options(struct netpoll *np, char *opt)
540 {
541 char *cur=opt, *delim;
542 int ipv6;
543 bool ipversion_set = false;
544
545 if (*cur != '@') {
546 if ((delim = strchr(cur, '@')) == NULL)
547 goto parse_failed;
548 *delim = 0;
549 if (kstrtou16(cur, 10, &np->local_port))
550 goto parse_failed;
551 cur = delim;
552 }
553 cur++;
554
555 if (*cur != '/') {
556 ipversion_set = true;
557 if ((delim = strchr(cur, '/')) == NULL)
558 goto parse_failed;
559 *delim = 0;
560 ipv6 = netpoll_parse_ip_addr(cur, &np->local_ip);
561 if (ipv6 < 0)
562 goto parse_failed;
563 else
564 np->ipv6 = (bool)ipv6;
565 cur = delim;
566 }
567 cur++;
568
569 if (*cur != ',') {
570 /* parse out dev name */
571 if ((delim = strchr(cur, ',')) == NULL)
572 goto parse_failed;
573 *delim = 0;
574 strscpy(np->dev_name, cur, sizeof(np->dev_name));
575 cur = delim;
576 }
577 cur++;
578
579 if (*cur != '@') {
580 /* dst port */
581 if ((delim = strchr(cur, '@')) == NULL)
582 goto parse_failed;
583 *delim = 0;
584 if (*cur == ' ' || *cur == '\t')
585 np_info(np, "warning: whitespace is not allowed\n");
586 if (kstrtou16(cur, 10, &np->remote_port))
587 goto parse_failed;
588 cur = delim;
589 }
590 cur++;
591
592 /* dst ip */
593 if ((delim = strchr(cur, '/')) == NULL)
594 goto parse_failed;
595 *delim = 0;
596 ipv6 = netpoll_parse_ip_addr(cur, &np->remote_ip);
597 if (ipv6 < 0)
598 goto parse_failed;
599 else if (ipversion_set && np->ipv6 != (bool)ipv6)
600 goto parse_failed;
601 else
602 np->ipv6 = (bool)ipv6;
603 cur = delim + 1;
604
605 if (*cur != 0) {
606 /* MAC address */
607 if (!mac_pton(cur, np->remote_mac))
608 goto parse_failed;
609 }
610
611 netpoll_print_options(np);
612
613 return 0;
614
615 parse_failed:
616 np_info(np, "couldn't parse config at '%s'!\n", cur);
617 return -1;
618 }
619 EXPORT_SYMBOL(netpoll_parse_options);
620
621 int __netpoll_setup(struct netpoll *np, struct net_device *ndev)
622 {
623 struct netpoll_info *npinfo;
624 const struct net_device_ops *ops;
625 int err;
626
627 if (ndev->priv_flags & IFF_DISABLE_NETPOLL) {
628 np_err(np, "%s doesn't support polling, aborting\n",
629 ndev->name);
630 err = -ENOTSUPP;
631 goto out;
632 }
633
634 if (!ndev->npinfo) {
635 npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL);
636 if (!npinfo) {
637 err = -ENOMEM;
638 goto out;
639 }
640
641 sema_init(&npinfo->dev_lock, 1);
642 skb_queue_head_init(&npinfo->txq);
643 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process);
644
645 refcount_set(&npinfo->refcnt, 1);
646
647 ops = ndev->netdev_ops;
648 if (ops->ndo_netpoll_setup) {
649 err = ops->ndo_netpoll_setup(ndev, npinfo);
650 if (err)
651 goto free_npinfo;
652 }
653 } else {
654 npinfo = rtnl_dereference(ndev->npinfo);
655 refcount_inc(&npinfo->refcnt);
656 }
657
658 np->dev = ndev;
659 strscpy(np->dev_name, ndev->name, IFNAMSIZ);
660 npinfo->netpoll = np;
661
662 /* last thing to do is link it to the net device structure */
663 rcu_assign_pointer(ndev->npinfo, npinfo);
664
665 return 0;
666
667 free_npinfo:
668 kfree(npinfo);
669 out:
670 return err;
671 }
672 EXPORT_SYMBOL_GPL(__netpoll_setup);
673
674 int netpoll_setup(struct netpoll *np)
675 {
676 struct net_device *ndev = NULL;
677 bool ip_overwritten = false;
678 struct in_device *in_dev;
679 int err;
680
681 rtnl_lock();
682 if (np->dev_name[0]) {
683 struct net *net = current->nsproxy->net_ns;
684 ndev = __dev_get_by_name(net, np->dev_name);
685 }
686 if (!ndev) {
687 np_err(np, "%s doesn't exist, aborting\n", np->dev_name);
688 err = -ENODEV;
689 goto unlock;
690 }
691 netdev_hold(ndev, &np->dev_tracker, GFP_KERNEL);
692
693 if (netdev_master_upper_dev_get(ndev)) {
694 np_err(np, "%s is a slave device, aborting\n", np->dev_name);
695 err = -EBUSY;
696 goto put;
697 }
698
699 if (!netif_running(ndev)) {
700 unsigned long atmost;
701
702 np_info(np, "device %s not up yet, forcing it\n", np->dev_name);
703
704 err = dev_open(ndev, NULL);
705
706 if (err) {
707 np_err(np, "failed to open %s\n", ndev->name);
708 goto put;
709 }
710
711 rtnl_unlock();
712 atmost = jiffies + carrier_timeout * HZ;
713 while (!netif_carrier_ok(ndev)) {
714 if (time_after(jiffies, atmost)) {
715 np_notice(np, "timeout waiting for carrier\n");
716 break;
717 }
718 msleep(1);
719 }
720
721 rtnl_lock();
722 }
723
724 if (!np->local_ip.ip) {
725 if (!np->ipv6) {
726 const struct in_ifaddr *ifa;
727
728 in_dev = __in_dev_get_rtnl(ndev);
729 if (!in_dev)
730 goto put_noaddr;
731
732 ifa = rtnl_dereference(in_dev->ifa_list);
733 if (!ifa) {
734 put_noaddr:
735 np_err(np, "no IP address for %s, aborting\n",
736 np->dev_name);
737 err = -EDESTADDRREQ;
738 goto put;
739 }
740
741 np->local_ip.ip = ifa->ifa_local;
742 ip_overwritten = true;
743 np_info(np, "local IP %pI4\n", &np->local_ip.ip);
744 } else {
745 #if IS_ENABLED(CONFIG_IPV6)
746 struct inet6_dev *idev;
747
748 err = -EDESTADDRREQ;
749 idev = __in6_dev_get(ndev);
750 if (idev) {
751 struct inet6_ifaddr *ifp;
752
753 read_lock_bh(&idev->lock);
754 list_for_each_entry(ifp, &idev->addr_list, if_list) {
755 if (!!(ipv6_addr_type(&ifp->addr) & IPV6_ADDR_LINKLOCAL) !=
756 !!(ipv6_addr_type(&np->remote_ip.in6) & IPV6_ADDR_LINKLOCAL))
757 continue;
758 np->local_ip.in6 = ifp->addr;
759 ip_overwritten = true;
760 err = 0;
761 break;
762 }
763 read_unlock_bh(&idev->lock);
764 }
765 if (err) {
766 np_err(np, "no IPv6 address for %s, aborting\n",
767 np->dev_name);
768 goto put;
769 } else
770 np_info(np, "local IPv6 %pI6c\n", &np->local_ip.in6);
771 #else
772 np_err(np, "IPv6 is not supported %s, aborting\n",
773 np->dev_name);
774 err = -EINVAL;
775 goto put;
776 #endif
777 }
778 }
779
780 /* fill up the skb queue */
781 refill_skbs();
782
783 err = __netpoll_setup(np, ndev);
784 if (err)
785 goto put;
786 rtnl_unlock();
787 return 0;
788
789 put:
790 DEBUG_NET_WARN_ON_ONCE(np->dev);
791 if (ip_overwritten)
792 memset(&np->local_ip, 0, sizeof(np->local_ip));
793 netdev_put(ndev, &np->dev_tracker);
794 unlock:
795 rtnl_unlock();
796 return err;
797 }
798 EXPORT_SYMBOL(netpoll_setup);
799
800 static int __init netpoll_init(void)
801 {
802 skb_queue_head_init(&skb_pool);
803 return 0;
804 }
805 core_initcall(netpoll_init);
806
807 static void rcu_cleanup_netpoll_info(struct rcu_head *rcu_head)
808 {
809 struct netpoll_info *npinfo =
810 container_of(rcu_head, struct netpoll_info, rcu);
811
812 skb_queue_purge(&npinfo->txq);
813
814 /* we can't call cancel_delayed_work_sync here, as we are in softirq */
815 cancel_delayed_work(&npinfo->tx_work);
816
817 /* clean after last, unfinished work */
818 __skb_queue_purge(&npinfo->txq);
819 /* now cancel it again */
820 cancel_delayed_work(&npinfo->tx_work);
821 kfree(npinfo);
822 }
823
824 void __netpoll_cleanup(struct netpoll *np)
825 {
826 struct netpoll_info *npinfo;
827
828 npinfo = rtnl_dereference(np->dev->npinfo);
829 if (!npinfo)
830 return;
831
832 synchronize_srcu(&netpoll_srcu);
833
834 if (refcount_dec_and_test(&npinfo->refcnt)) {
835 const struct net_device_ops *ops;
836
837 ops = np->dev->netdev_ops;
838 if (ops->ndo_netpoll_cleanup)
839 ops->ndo_netpoll_cleanup(np->dev);
840
841 RCU_INIT_POINTER(np->dev->npinfo, NULL);
842 call_rcu(&npinfo->rcu, rcu_cleanup_netpoll_info);
843 } else
844 RCU_INIT_POINTER(np->dev->npinfo, NULL);
845 }
846 EXPORT_SYMBOL_GPL(__netpoll_cleanup);
847
848 void __netpoll_free(struct netpoll *np)
849 {
850 ASSERT_RTNL();
851
852 /* Wait for transmitting packets to finish before freeing. */
853 synchronize_rcu();
854 __netpoll_cleanup(np);
855 kfree(np);
856 }
857 EXPORT_SYMBOL_GPL(__netpoll_free);
858
859 void netpoll_cleanup(struct netpoll *np)
860 {
861 rtnl_lock();
862 if (!np->dev)
863 goto out;
864 __netpoll_cleanup(np);
865 netdev_put(np->dev, &np->dev_tracker);
866 np->dev = NULL;
867 out:
868 rtnl_unlock();
869 }
870 EXPORT_SYMBOL(netpoll_cleanup);
871
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