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 DEFINE_STATIC_SRCU(netpoll_srcu);
50
51 #define USEC_PER_POLL 50
52
53 #define MAX_SKB_SIZE \
54 (sizeof(struct ethhdr) + \
55 sizeof(struct iphdr) + \
56 sizeof(struct udphdr) + \
57 MAX_UDP_CHUNK)
58
59 static void zap_completion_queue(void);
60 static void netpoll_async_cleanup(struct work_struct *work);
61
62 static unsigned int carrier_timeout = 4;
63 module_param(carrier_timeout, uint, 0644);
64
65 #define np_info(np, fmt, ...) \
66 pr_info("%s: " fmt, np->name, ##__VA_ARGS__)
67 #define np_err(np, fmt, ...) \
68 pr_err("%s: " fmt, np->name, ##__VA_ARGS__)
69 #define np_notice(np, fmt, ...) \
70 pr_notice("%s: " fmt, np->name, ##__VA_ARGS__)
71
netpoll_start_xmit(struct sk_buff * skb,struct net_device * dev,struct netdev_queue * txq)72 static int netpoll_start_xmit(struct sk_buff *skb, struct net_device *dev,
73 struct netdev_queue *txq)
74 {
75 int status = NETDEV_TX_OK;
76 netdev_features_t features;
77
78 features = netif_skb_features(skb);
79
80 if (skb_vlan_tag_present(skb) &&
81 !vlan_hw_offload_capable(features, skb->vlan_proto)) {
82 skb = __vlan_hwaccel_push_inside(skb);
83 if (unlikely(!skb)) {
84 /* This is actually a packet drop, but we
85 * don't want the code that calls this
86 * function to try and operate on a NULL skb.
87 */
88 goto out;
89 }
90 }
91
92 status = netdev_start_xmit(skb, dev, txq, false);
93
94 out:
95 return status;
96 }
97
queue_process(struct work_struct * work)98 static void queue_process(struct work_struct *work)
99 {
100 struct netpoll_info *npinfo =
101 container_of(work, struct netpoll_info, tx_work.work);
102 struct sk_buff *skb;
103 unsigned long flags;
104
105 while ((skb = skb_dequeue(&npinfo->txq))) {
106 struct net_device *dev = skb->dev;
107 struct netdev_queue *txq;
108 unsigned int q_index;
109
110 if (!netif_device_present(dev) || !netif_running(dev)) {
111 kfree_skb(skb);
112 continue;
113 }
114
115 local_irq_save(flags);
116 /* check if skb->queue_mapping is still valid */
117 q_index = skb_get_queue_mapping(skb);
118 if (unlikely(q_index >= dev->real_num_tx_queues)) {
119 q_index = q_index % dev->real_num_tx_queues;
120 skb_set_queue_mapping(skb, q_index);
121 }
122 txq = netdev_get_tx_queue(dev, q_index);
123 HARD_TX_LOCK(dev, txq, smp_processor_id());
124 if (netif_xmit_frozen_or_stopped(txq) ||
125 netpoll_start_xmit(skb, dev, txq) != NETDEV_TX_OK) {
126 skb_queue_head(&npinfo->txq, skb);
127 HARD_TX_UNLOCK(dev, txq);
128 local_irq_restore(flags);
129
130 schedule_delayed_work(&npinfo->tx_work, HZ/10);
131 return;
132 }
133 HARD_TX_UNLOCK(dev, txq);
134 local_irq_restore(flags);
135 }
136 }
137
poll_one_napi(struct napi_struct * napi)138 static void poll_one_napi(struct napi_struct *napi)
139 {
140 int work;
141
142 /* If we set this bit but see that it has already been set,
143 * that indicates that napi has been disabled and we need
144 * to abort this operation
145 */
146 if (test_and_set_bit(NAPI_STATE_NPSVC, &napi->state))
147 return;
148
149 /* We explicilty pass the polling call a budget of 0 to
150 * indicate that we are clearing the Tx path only.
151 */
152 work = napi->poll(napi, 0);
153 WARN_ONCE(work, "%pF exceeded budget in poll\n", napi->poll);
154 trace_napi_poll(napi, work, 0);
155
156 clear_bit(NAPI_STATE_NPSVC, &napi->state);
157 }
158
poll_napi(struct net_device * dev)159 static void poll_napi(struct net_device *dev)
160 {
161 struct napi_struct *napi;
162 int cpu = smp_processor_id();
163
164 list_for_each_entry(napi, &dev->napi_list, dev_list) {
165 if (cmpxchg(&napi->poll_owner, -1, cpu) == -1) {
166 poll_one_napi(napi);
167 smp_store_release(&napi->poll_owner, -1);
168 }
169 }
170 }
171
netpoll_poll_dev(struct net_device * dev)172 void netpoll_poll_dev(struct net_device *dev)
173 {
174 struct netpoll_info *ni = rcu_dereference_bh(dev->npinfo);
175 const struct net_device_ops *ops;
176
177 /* Don't do any rx activity if the dev_lock mutex is held
178 * the dev_open/close paths use this to block netpoll activity
179 * while changing device state
180 */
181 if (!ni || down_trylock(&ni->dev_lock))
182 return;
183
184 if (!netif_running(dev)) {
185 up(&ni->dev_lock);
186 return;
187 }
188
189 ops = dev->netdev_ops;
190 if (ops->ndo_poll_controller)
191 ops->ndo_poll_controller(dev);
192
193 poll_napi(dev);
194
195 up(&ni->dev_lock);
196
197 zap_completion_queue();
198 }
199 EXPORT_SYMBOL(netpoll_poll_dev);
200
netpoll_poll_disable(struct net_device * dev)201 void netpoll_poll_disable(struct net_device *dev)
202 {
203 struct netpoll_info *ni;
204 int idx;
205 might_sleep();
206 idx = srcu_read_lock(&netpoll_srcu);
207 ni = srcu_dereference(dev->npinfo, &netpoll_srcu);
208 if (ni)
209 down(&ni->dev_lock);
210 srcu_read_unlock(&netpoll_srcu, idx);
211 }
212 EXPORT_SYMBOL(netpoll_poll_disable);
213
netpoll_poll_enable(struct net_device * dev)214 void netpoll_poll_enable(struct net_device *dev)
215 {
216 struct netpoll_info *ni;
217 rcu_read_lock();
218 ni = rcu_dereference(dev->npinfo);
219 if (ni)
220 up(&ni->dev_lock);
221 rcu_read_unlock();
222 }
223 EXPORT_SYMBOL(netpoll_poll_enable);
224
refill_skbs(void)225 static void refill_skbs(void)
226 {
227 struct sk_buff *skb;
228 unsigned long flags;
229
230 spin_lock_irqsave(&skb_pool.lock, flags);
231 while (skb_pool.qlen < MAX_SKBS) {
232 skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC);
233 if (!skb)
234 break;
235
236 __skb_queue_tail(&skb_pool, skb);
237 }
238 spin_unlock_irqrestore(&skb_pool.lock, flags);
239 }
240
zap_completion_queue(void)241 static void zap_completion_queue(void)
242 {
243 unsigned long flags;
244 struct softnet_data *sd = &get_cpu_var(softnet_data);
245
246 if (sd->completion_queue) {
247 struct sk_buff *clist;
248
249 local_irq_save(flags);
250 clist = sd->completion_queue;
251 sd->completion_queue = NULL;
252 local_irq_restore(flags);
253
254 while (clist != NULL) {
255 struct sk_buff *skb = clist;
256 clist = clist->next;
257 if (!skb_irq_freeable(skb)) {
258 refcount_set(&skb->users, 1);
259 dev_kfree_skb_any(skb); /* put this one back */
260 } else {
261 __kfree_skb(skb);
262 }
263 }
264 }
265
266 put_cpu_var(softnet_data);
267 }
268
find_skb(struct netpoll * np,int len,int reserve)269 static struct sk_buff *find_skb(struct netpoll *np, int len, int reserve)
270 {
271 int count = 0;
272 struct sk_buff *skb;
273
274 zap_completion_queue();
275 refill_skbs();
276 repeat:
277
278 skb = alloc_skb(len, GFP_ATOMIC);
279 if (!skb)
280 skb = skb_dequeue(&skb_pool);
281
282 if (!skb) {
283 if (++count < 10) {
284 netpoll_poll_dev(np->dev);
285 goto repeat;
286 }
287 return NULL;
288 }
289
290 refcount_set(&skb->users, 1);
291 skb_reserve(skb, reserve);
292 return skb;
293 }
294
netpoll_owner_active(struct net_device * dev)295 static int netpoll_owner_active(struct net_device *dev)
296 {
297 struct napi_struct *napi;
298
299 list_for_each_entry(napi, &dev->napi_list, dev_list) {
300 if (napi->poll_owner == smp_processor_id())
301 return 1;
302 }
303 return 0;
304 }
305
306 /* call with IRQ disabled */
netpoll_send_skb_on_dev(struct netpoll * np,struct sk_buff * skb,struct net_device * dev)307 void netpoll_send_skb_on_dev(struct netpoll *np, struct sk_buff *skb,
308 struct net_device *dev)
309 {
310 int status = NETDEV_TX_BUSY;
311 unsigned long tries;
312 /* It is up to the caller to keep npinfo alive. */
313 struct netpoll_info *npinfo;
314
315 lockdep_assert_irqs_disabled();
316
317 npinfo = rcu_dereference_bh(np->dev->npinfo);
318 if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) {
319 dev_kfree_skb_irq(skb);
320 return;
321 }
322
323 /* don't get messages out of order, and no recursion */
324 if (skb_queue_len(&npinfo->txq) == 0 && !netpoll_owner_active(dev)) {
325 struct netdev_queue *txq;
326
327 txq = netdev_pick_tx(dev, skb, NULL);
328
329 /* try until next clock tick */
330 for (tries = jiffies_to_usecs(1)/USEC_PER_POLL;
331 tries > 0; --tries) {
332 if (HARD_TX_TRYLOCK(dev, txq)) {
333 if (!netif_xmit_stopped(txq))
334 status = netpoll_start_xmit(skb, dev, txq);
335
336 HARD_TX_UNLOCK(dev, txq);
337
338 if (status == NETDEV_TX_OK)
339 break;
340
341 }
342
343 /* tickle device maybe there is some cleanup */
344 netpoll_poll_dev(np->dev);
345
346 udelay(USEC_PER_POLL);
347 }
348
349 WARN_ONCE(!irqs_disabled(),
350 "netpoll_send_skb_on_dev(): %s enabled interrupts in poll (%pF)\n",
351 dev->name, dev->netdev_ops->ndo_start_xmit);
352
353 }
354
355 if (status != NETDEV_TX_OK) {
356 skb_queue_tail(&npinfo->txq, skb);
357 schedule_delayed_work(&npinfo->tx_work,0);
358 }
359 }
360 EXPORT_SYMBOL(netpoll_send_skb_on_dev);
361
netpoll_send_udp(struct netpoll * np,const char * msg,int len)362 void netpoll_send_udp(struct netpoll *np, const char *msg, int len)
363 {
364 int total_len, ip_len, udp_len;
365 struct sk_buff *skb;
366 struct udphdr *udph;
367 struct iphdr *iph;
368 struct ethhdr *eth;
369 static atomic_t ip_ident;
370 struct ipv6hdr *ip6h;
371
372 WARN_ON_ONCE(!irqs_disabled());
373
374 udp_len = len + sizeof(*udph);
375 if (np->ipv6)
376 ip_len = udp_len + sizeof(*ip6h);
377 else
378 ip_len = udp_len + sizeof(*iph);
379
380 total_len = ip_len + LL_RESERVED_SPACE(np->dev);
381
382 skb = find_skb(np, total_len + np->dev->needed_tailroom,
383 total_len - len);
384 if (!skb)
385 return;
386
387 skb_copy_to_linear_data(skb, msg, len);
388 skb_put(skb, len);
389
390 skb_push(skb, sizeof(*udph));
391 skb_reset_transport_header(skb);
392 udph = udp_hdr(skb);
393 udph->source = htons(np->local_port);
394 udph->dest = htons(np->remote_port);
395 udph->len = htons(udp_len);
396
397 if (np->ipv6) {
398 udph->check = 0;
399 udph->check = csum_ipv6_magic(&np->local_ip.in6,
400 &np->remote_ip.in6,
401 udp_len, IPPROTO_UDP,
402 csum_partial(udph, udp_len, 0));
403 if (udph->check == 0)
404 udph->check = CSUM_MANGLED_0;
405
406 skb_push(skb, sizeof(*ip6h));
407 skb_reset_network_header(skb);
408 ip6h = ipv6_hdr(skb);
409
410 /* ip6h->version = 6; ip6h->priority = 0; */
411 put_unaligned(0x60, (unsigned char *)ip6h);
412 ip6h->flow_lbl[0] = 0;
413 ip6h->flow_lbl[1] = 0;
414 ip6h->flow_lbl[2] = 0;
415
416 ip6h->payload_len = htons(sizeof(struct udphdr) + len);
417 ip6h->nexthdr = IPPROTO_UDP;
418 ip6h->hop_limit = 32;
419 ip6h->saddr = np->local_ip.in6;
420 ip6h->daddr = np->remote_ip.in6;
421
422 eth = skb_push(skb, ETH_HLEN);
423 skb_reset_mac_header(skb);
424 skb->protocol = eth->h_proto = htons(ETH_P_IPV6);
425 } else {
426 udph->check = 0;
427 udph->check = csum_tcpudp_magic(np->local_ip.ip,
428 np->remote_ip.ip,
429 udp_len, IPPROTO_UDP,
430 csum_partial(udph, udp_len, 0));
431 if (udph->check == 0)
432 udph->check = CSUM_MANGLED_0;
433
434 skb_push(skb, sizeof(*iph));
435 skb_reset_network_header(skb);
436 iph = ip_hdr(skb);
437
438 /* iph->version = 4; iph->ihl = 5; */
439 put_unaligned(0x45, (unsigned char *)iph);
440 iph->tos = 0;
441 put_unaligned(htons(ip_len), &(iph->tot_len));
442 iph->id = htons(atomic_inc_return(&ip_ident));
443 iph->frag_off = 0;
444 iph->ttl = 64;
445 iph->protocol = IPPROTO_UDP;
446 iph->check = 0;
447 put_unaligned(np->local_ip.ip, &(iph->saddr));
448 put_unaligned(np->remote_ip.ip, &(iph->daddr));
449 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl);
450
451 eth = skb_push(skb, ETH_HLEN);
452 skb_reset_mac_header(skb);
453 skb->protocol = eth->h_proto = htons(ETH_P_IP);
454 }
455
456 ether_addr_copy(eth->h_source, np->dev->dev_addr);
457 ether_addr_copy(eth->h_dest, np->remote_mac);
458
459 skb->dev = np->dev;
460
461 netpoll_send_skb(np, skb);
462 }
463 EXPORT_SYMBOL(netpoll_send_udp);
464
netpoll_print_options(struct netpoll * np)465 void netpoll_print_options(struct netpoll *np)
466 {
467 np_info(np, "local port %d\n", np->local_port);
468 if (np->ipv6)
469 np_info(np, "local IPv6 address %pI6c\n", &np->local_ip.in6);
470 else
471 np_info(np, "local IPv4 address %pI4\n", &np->local_ip.ip);
472 np_info(np, "interface '%s'\n", np->dev_name);
473 np_info(np, "remote port %d\n", np->remote_port);
474 if (np->ipv6)
475 np_info(np, "remote IPv6 address %pI6c\n", &np->remote_ip.in6);
476 else
477 np_info(np, "remote IPv4 address %pI4\n", &np->remote_ip.ip);
478 np_info(np, "remote ethernet address %pM\n", np->remote_mac);
479 }
480 EXPORT_SYMBOL(netpoll_print_options);
481
netpoll_parse_ip_addr(const char * str,union inet_addr * addr)482 static int netpoll_parse_ip_addr(const char *str, union inet_addr *addr)
483 {
484 const char *end;
485
486 if (!strchr(str, ':') &&
487 in4_pton(str, -1, (void *)addr, -1, &end) > 0) {
488 if (!*end)
489 return 0;
490 }
491 if (in6_pton(str, -1, addr->in6.s6_addr, -1, &end) > 0) {
492 #if IS_ENABLED(CONFIG_IPV6)
493 if (!*end)
494 return 1;
495 #else
496 return -1;
497 #endif
498 }
499 return -1;
500 }
501
netpoll_parse_options(struct netpoll * np,char * opt)502 int netpoll_parse_options(struct netpoll *np, char *opt)
503 {
504 char *cur=opt, *delim;
505 int ipv6;
506 bool ipversion_set = false;
507
508 if (*cur != '@') {
509 if ((delim = strchr(cur, '@')) == NULL)
510 goto parse_failed;
511 *delim = 0;
512 if (kstrtou16(cur, 10, &np->local_port))
513 goto parse_failed;
514 cur = delim;
515 }
516 cur++;
517
518 if (*cur != '/') {
519 ipversion_set = true;
520 if ((delim = strchr(cur, '/')) == NULL)
521 goto parse_failed;
522 *delim = 0;
523 ipv6 = netpoll_parse_ip_addr(cur, &np->local_ip);
524 if (ipv6 < 0)
525 goto parse_failed;
526 else
527 np->ipv6 = (bool)ipv6;
528 cur = delim;
529 }
530 cur++;
531
532 if (*cur != ',') {
533 /* parse out dev name */
534 if ((delim = strchr(cur, ',')) == NULL)
535 goto parse_failed;
536 *delim = 0;
537 strlcpy(np->dev_name, cur, sizeof(np->dev_name));
538 cur = delim;
539 }
540 cur++;
541
542 if (*cur != '@') {
543 /* dst port */
544 if ((delim = strchr(cur, '@')) == NULL)
545 goto parse_failed;
546 *delim = 0;
547 if (*cur == ' ' || *cur == '\t')
548 np_info(np, "warning: whitespace is not allowed\n");
549 if (kstrtou16(cur, 10, &np->remote_port))
550 goto parse_failed;
551 cur = delim;
552 }
553 cur++;
554
555 /* dst ip */
556 if ((delim = strchr(cur, '/')) == NULL)
557 goto parse_failed;
558 *delim = 0;
559 ipv6 = netpoll_parse_ip_addr(cur, &np->remote_ip);
560 if (ipv6 < 0)
561 goto parse_failed;
562 else if (ipversion_set && np->ipv6 != (bool)ipv6)
563 goto parse_failed;
564 else
565 np->ipv6 = (bool)ipv6;
566 cur = delim + 1;
567
568 if (*cur != 0) {
569 /* MAC address */
570 if (!mac_pton(cur, np->remote_mac))
571 goto parse_failed;
572 }
573
574 netpoll_print_options(np);
575
576 return 0;
577
578 parse_failed:
579 np_info(np, "couldn't parse config at '%s'!\n", cur);
580 return -1;
581 }
582 EXPORT_SYMBOL(netpoll_parse_options);
583
__netpoll_setup(struct netpoll * np,struct net_device * ndev)584 int __netpoll_setup(struct netpoll *np, struct net_device *ndev)
585 {
586 struct netpoll_info *npinfo;
587 const struct net_device_ops *ops;
588 int err;
589
590 np->dev = ndev;
591 strlcpy(np->dev_name, ndev->name, IFNAMSIZ);
592 INIT_WORK(&np->cleanup_work, netpoll_async_cleanup);
593
594 if (ndev->priv_flags & IFF_DISABLE_NETPOLL) {
595 np_err(np, "%s doesn't support polling, aborting\n",
596 np->dev_name);
597 err = -ENOTSUPP;
598 goto out;
599 }
600
601 if (!ndev->npinfo) {
602 npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL);
603 if (!npinfo) {
604 err = -ENOMEM;
605 goto out;
606 }
607
608 sema_init(&npinfo->dev_lock, 1);
609 skb_queue_head_init(&npinfo->txq);
610 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process);
611
612 refcount_set(&npinfo->refcnt, 1);
613
614 ops = np->dev->netdev_ops;
615 if (ops->ndo_netpoll_setup) {
616 err = ops->ndo_netpoll_setup(ndev, npinfo);
617 if (err)
618 goto free_npinfo;
619 }
620 } else {
621 npinfo = rtnl_dereference(ndev->npinfo);
622 refcount_inc(&npinfo->refcnt);
623 }
624
625 npinfo->netpoll = np;
626
627 /* last thing to do is link it to the net device structure */
628 rcu_assign_pointer(ndev->npinfo, npinfo);
629
630 return 0;
631
632 free_npinfo:
633 kfree(npinfo);
634 out:
635 return err;
636 }
637 EXPORT_SYMBOL_GPL(__netpoll_setup);
638
netpoll_setup(struct netpoll * np)639 int netpoll_setup(struct netpoll *np)
640 {
641 struct net_device *ndev = NULL;
642 struct in_device *in_dev;
643 int err;
644
645 rtnl_lock();
646 if (np->dev_name[0]) {
647 struct net *net = current->nsproxy->net_ns;
648 ndev = __dev_get_by_name(net, np->dev_name);
649 }
650 if (!ndev) {
651 np_err(np, "%s doesn't exist, aborting\n", np->dev_name);
652 err = -ENODEV;
653 goto unlock;
654 }
655 dev_hold(ndev);
656
657 if (netdev_master_upper_dev_get(ndev)) {
658 np_err(np, "%s is a slave device, aborting\n", np->dev_name);
659 err = -EBUSY;
660 goto put;
661 }
662
663 if (!netif_running(ndev)) {
664 unsigned long atmost, atleast;
665
666 np_info(np, "device %s not up yet, forcing it\n", np->dev_name);
667
668 err = dev_open(ndev);
669
670 if (err) {
671 np_err(np, "failed to open %s\n", ndev->name);
672 goto put;
673 }
674
675 rtnl_unlock();
676 atleast = jiffies + HZ/10;
677 atmost = jiffies + carrier_timeout * HZ;
678 while (!netif_carrier_ok(ndev)) {
679 if (time_after(jiffies, atmost)) {
680 np_notice(np, "timeout waiting for carrier\n");
681 break;
682 }
683 msleep(1);
684 }
685
686 /* If carrier appears to come up instantly, we don't
687 * trust it and pause so that we don't pump all our
688 * queued console messages into the bitbucket.
689 */
690
691 if (time_before(jiffies, atleast)) {
692 np_notice(np, "carrier detect appears untrustworthy, waiting 4 seconds\n");
693 msleep(4000);
694 }
695 rtnl_lock();
696 }
697
698 if (!np->local_ip.ip) {
699 if (!np->ipv6) {
700 in_dev = __in_dev_get_rtnl(ndev);
701
702 if (!in_dev || !in_dev->ifa_list) {
703 np_err(np, "no IP address for %s, aborting\n",
704 np->dev_name);
705 err = -EDESTADDRREQ;
706 goto put;
707 }
708
709 np->local_ip.ip = in_dev->ifa_list->ifa_local;
710 np_info(np, "local IP %pI4\n", &np->local_ip.ip);
711 } else {
712 #if IS_ENABLED(CONFIG_IPV6)
713 struct inet6_dev *idev;
714
715 err = -EDESTADDRREQ;
716 idev = __in6_dev_get(ndev);
717 if (idev) {
718 struct inet6_ifaddr *ifp;
719
720 read_lock_bh(&idev->lock);
721 list_for_each_entry(ifp, &idev->addr_list, if_list) {
722 if (ipv6_addr_type(&ifp->addr) & IPV6_ADDR_LINKLOCAL)
723 continue;
724 np->local_ip.in6 = ifp->addr;
725 err = 0;
726 break;
727 }
728 read_unlock_bh(&idev->lock);
729 }
730 if (err) {
731 np_err(np, "no IPv6 address for %s, aborting\n",
732 np->dev_name);
733 goto put;
734 } else
735 np_info(np, "local IPv6 %pI6c\n", &np->local_ip.in6);
736 #else
737 np_err(np, "IPv6 is not supported %s, aborting\n",
738 np->dev_name);
739 err = -EINVAL;
740 goto put;
741 #endif
742 }
743 }
744
745 /* fill up the skb queue */
746 refill_skbs();
747
748 err = __netpoll_setup(np, ndev);
749 if (err)
750 goto put;
751
752 rtnl_unlock();
753 return 0;
754
755 put:
756 dev_put(ndev);
757 unlock:
758 rtnl_unlock();
759 return err;
760 }
761 EXPORT_SYMBOL(netpoll_setup);
762
netpoll_init(void)763 static int __init netpoll_init(void)
764 {
765 skb_queue_head_init(&skb_pool);
766 return 0;
767 }
768 core_initcall(netpoll_init);
769
rcu_cleanup_netpoll_info(struct rcu_head * rcu_head)770 static void rcu_cleanup_netpoll_info(struct rcu_head *rcu_head)
771 {
772 struct netpoll_info *npinfo =
773 container_of(rcu_head, struct netpoll_info, rcu);
774
775 skb_queue_purge(&npinfo->txq);
776
777 /* we can't call cancel_delayed_work_sync here, as we are in softirq */
778 cancel_delayed_work(&npinfo->tx_work);
779
780 /* clean after last, unfinished work */
781 __skb_queue_purge(&npinfo->txq);
782 /* now cancel it again */
783 cancel_delayed_work(&npinfo->tx_work);
784 kfree(npinfo);
785 }
786
__netpoll_cleanup(struct netpoll * np)787 void __netpoll_cleanup(struct netpoll *np)
788 {
789 struct netpoll_info *npinfo;
790
791 /* rtnl_dereference would be preferable here but
792 * rcu_cleanup_netpoll path can put us in here safely without
793 * holding the rtnl, so plain rcu_dereference it is
794 */
795 npinfo = rtnl_dereference(np->dev->npinfo);
796 if (!npinfo)
797 return;
798
799 synchronize_srcu(&netpoll_srcu);
800
801 if (refcount_dec_and_test(&npinfo->refcnt)) {
802 const struct net_device_ops *ops;
803
804 ops = np->dev->netdev_ops;
805 if (ops->ndo_netpoll_cleanup)
806 ops->ndo_netpoll_cleanup(np->dev);
807
808 RCU_INIT_POINTER(np->dev->npinfo, NULL);
809 call_rcu_bh(&npinfo->rcu, rcu_cleanup_netpoll_info);
810 } else
811 RCU_INIT_POINTER(np->dev->npinfo, NULL);
812 }
813 EXPORT_SYMBOL_GPL(__netpoll_cleanup);
814
netpoll_async_cleanup(struct work_struct * work)815 static void netpoll_async_cleanup(struct work_struct *work)
816 {
817 struct netpoll *np = container_of(work, struct netpoll, cleanup_work);
818
819 rtnl_lock();
820 __netpoll_cleanup(np);
821 rtnl_unlock();
822 kfree(np);
823 }
824
__netpoll_free_async(struct netpoll * np)825 void __netpoll_free_async(struct netpoll *np)
826 {
827 schedule_work(&np->cleanup_work);
828 }
829 EXPORT_SYMBOL_GPL(__netpoll_free_async);
830
netpoll_cleanup(struct netpoll * np)831 void netpoll_cleanup(struct netpoll *np)
832 {
833 rtnl_lock();
834 if (!np->dev)
835 goto out;
836 __netpoll_cleanup(np);
837 dev_put(np->dev);
838 np->dev = NULL;
839 out:
840 rtnl_unlock();
841 }
842 EXPORT_SYMBOL(netpoll_cleanup);
843
