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 (vlan_tx_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
138 /*
139 * Check whether delayed processing was scheduled for our NIC. If so,
140 * we attempt to grab the poll lock and use ->poll() to pump the card.
141 * If this fails, either we've recursed in ->poll() or it's already
142 * running on another CPU.
143 *
144 * Note: we don't mask interrupts with this lock because we're using
145 * trylock here and interrupts are already disabled in the softirq
146 * case. Further, we test the poll_owner to avoid recursion on UP
147 * systems where the lock doesn't exist.
148 */
poll_one_napi(struct napi_struct * napi,int budget)149 static int poll_one_napi(struct napi_struct *napi, int budget)
150 {
151 int work;
152
153 /* net_rx_action's ->poll() invocations and our's are
154 * synchronized by this test which is only made while
155 * holding the napi->poll_lock.
156 */
157 if (!test_bit(NAPI_STATE_SCHED, &napi->state))
158 return budget;
159
160 set_bit(NAPI_STATE_NPSVC, &napi->state);
161
162 work = napi->poll(napi, budget);
163 WARN_ONCE(work > budget, "%pF exceeded budget in poll\n", napi->poll);
164 trace_napi_poll(napi);
165
166 clear_bit(NAPI_STATE_NPSVC, &napi->state);
167
168 return budget - work;
169 }
170
poll_napi(struct net_device * dev,int budget)171 static void poll_napi(struct net_device *dev, int budget)
172 {
173 struct napi_struct *napi;
174
175 list_for_each_entry(napi, &dev->napi_list, dev_list) {
176 if (napi->poll_owner != smp_processor_id() &&
177 spin_trylock(&napi->poll_lock)) {
178 budget = poll_one_napi(napi, budget);
179 spin_unlock(&napi->poll_lock);
180 }
181 }
182 }
183
netpoll_poll_dev(struct net_device * dev)184 static void netpoll_poll_dev(struct net_device *dev)
185 {
186 const struct net_device_ops *ops;
187 struct netpoll_info *ni = rcu_dereference_bh(dev->npinfo);
188 int budget = 0;
189
190 /* Don't do any rx activity if the dev_lock mutex is held
191 * the dev_open/close paths use this to block netpoll activity
192 * while changing device state
193 */
194 if (down_trylock(&ni->dev_lock))
195 return;
196
197 if (!netif_running(dev)) {
198 up(&ni->dev_lock);
199 return;
200 }
201
202 ops = dev->netdev_ops;
203 if (!ops->ndo_poll_controller) {
204 up(&ni->dev_lock);
205 return;
206 }
207
208 /* Process pending work on NIC */
209 ops->ndo_poll_controller(dev);
210
211 poll_napi(dev, budget);
212
213 up(&ni->dev_lock);
214
215 zap_completion_queue();
216 }
217
netpoll_poll_disable(struct net_device * dev)218 void netpoll_poll_disable(struct net_device *dev)
219 {
220 struct netpoll_info *ni;
221 int idx;
222 might_sleep();
223 idx = srcu_read_lock(&netpoll_srcu);
224 ni = srcu_dereference(dev->npinfo, &netpoll_srcu);
225 if (ni)
226 down(&ni->dev_lock);
227 srcu_read_unlock(&netpoll_srcu, idx);
228 }
229 EXPORT_SYMBOL(netpoll_poll_disable);
230
netpoll_poll_enable(struct net_device * dev)231 void netpoll_poll_enable(struct net_device *dev)
232 {
233 struct netpoll_info *ni;
234 rcu_read_lock();
235 ni = rcu_dereference(dev->npinfo);
236 if (ni)
237 up(&ni->dev_lock);
238 rcu_read_unlock();
239 }
240 EXPORT_SYMBOL(netpoll_poll_enable);
241
refill_skbs(void)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
zap_completion_queue(void)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 atomic_inc(&skb->users);
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
find_skb(struct netpoll * np,int len,int reserve)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 atomic_set(&skb->users, 1);
308 skb_reserve(skb, reserve);
309 return skb;
310 }
311
netpoll_owner_active(struct net_device * dev)312 static int netpoll_owner_active(struct net_device *dev)
313 {
314 struct napi_struct *napi;
315
316 list_for_each_entry(napi, &dev->napi_list, dev_list) {
317 if (napi->poll_owner == smp_processor_id())
318 return 1;
319 }
320 return 0;
321 }
322
323 /* call with IRQ disabled */
netpoll_send_skb_on_dev(struct netpoll * np,struct sk_buff * skb,struct net_device * dev)324 void netpoll_send_skb_on_dev(struct netpoll *np, struct sk_buff *skb,
325 struct net_device *dev)
326 {
327 int status = NETDEV_TX_BUSY;
328 unsigned long tries;
329 /* It is up to the caller to keep npinfo alive. */
330 struct netpoll_info *npinfo;
331
332 WARN_ON_ONCE(!irqs_disabled());
333
334 npinfo = rcu_dereference_bh(np->dev->npinfo);
335 if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) {
336 dev_kfree_skb_irq(skb);
337 return;
338 }
339
340 /* don't get messages out of order, and no recursion */
341 if (skb_queue_len(&npinfo->txq) == 0 && !netpoll_owner_active(dev)) {
342 struct netdev_queue *txq;
343
344 txq = netdev_pick_tx(dev, skb, NULL);
345
346 /* try until next clock tick */
347 for (tries = jiffies_to_usecs(1)/USEC_PER_POLL;
348 tries > 0; --tries) {
349 if (HARD_TX_TRYLOCK(dev, txq)) {
350 if (!netif_xmit_stopped(txq))
351 status = netpoll_start_xmit(skb, dev, txq);
352
353 HARD_TX_UNLOCK(dev, txq);
354
355 if (status == NETDEV_TX_OK)
356 break;
357
358 }
359
360 /* tickle device maybe there is some cleanup */
361 netpoll_poll_dev(np->dev);
362
363 udelay(USEC_PER_POLL);
364 }
365
366 WARN_ONCE(!irqs_disabled(),
367 "netpoll_send_skb_on_dev(): %s enabled interrupts in poll (%pF)\n",
368 dev->name, dev->netdev_ops->ndo_start_xmit);
369
370 }
371
372 if (status != NETDEV_TX_OK) {
373 skb_queue_tail(&npinfo->txq, skb);
374 schedule_delayed_work(&npinfo->tx_work,0);
375 }
376 }
377 EXPORT_SYMBOL(netpoll_send_skb_on_dev);
378
netpoll_send_udp(struct netpoll * np,const char * msg,int len)379 void netpoll_send_udp(struct netpoll *np, const char *msg, int len)
380 {
381 int total_len, ip_len, udp_len;
382 struct sk_buff *skb;
383 struct udphdr *udph;
384 struct iphdr *iph;
385 struct ethhdr *eth;
386 static atomic_t ip_ident;
387 struct ipv6hdr *ip6h;
388
389 udp_len = len + sizeof(*udph);
390 if (np->ipv6)
391 ip_len = udp_len + sizeof(*ip6h);
392 else
393 ip_len = udp_len + sizeof(*iph);
394
395 total_len = ip_len + LL_RESERVED_SPACE(np->dev);
396
397 skb = find_skb(np, total_len + np->dev->needed_tailroom,
398 total_len - len);
399 if (!skb)
400 return;
401
402 skb_copy_to_linear_data(skb, msg, len);
403 skb_put(skb, len);
404
405 skb_push(skb, sizeof(*udph));
406 skb_reset_transport_header(skb);
407 udph = udp_hdr(skb);
408 udph->source = htons(np->local_port);
409 udph->dest = htons(np->remote_port);
410 udph->len = htons(udp_len);
411
412 if (np->ipv6) {
413 udph->check = 0;
414 udph->check = csum_ipv6_magic(&np->local_ip.in6,
415 &np->remote_ip.in6,
416 udp_len, IPPROTO_UDP,
417 csum_partial(udph, udp_len, 0));
418 if (udph->check == 0)
419 udph->check = CSUM_MANGLED_0;
420
421 skb_push(skb, sizeof(*ip6h));
422 skb_reset_network_header(skb);
423 ip6h = ipv6_hdr(skb);
424
425 /* ip6h->version = 6; ip6h->priority = 0; */
426 put_unaligned(0x60, (unsigned char *)ip6h);
427 ip6h->flow_lbl[0] = 0;
428 ip6h->flow_lbl[1] = 0;
429 ip6h->flow_lbl[2] = 0;
430
431 ip6h->payload_len = htons(sizeof(struct udphdr) + len);
432 ip6h->nexthdr = IPPROTO_UDP;
433 ip6h->hop_limit = 32;
434 ip6h->saddr = np->local_ip.in6;
435 ip6h->daddr = np->remote_ip.in6;
436
437 eth = (struct ethhdr *) skb_push(skb, ETH_HLEN);
438 skb_reset_mac_header(skb);
439 skb->protocol = eth->h_proto = htons(ETH_P_IPV6);
440 } else {
441 udph->check = 0;
442 udph->check = csum_tcpudp_magic(np->local_ip.ip,
443 np->remote_ip.ip,
444 udp_len, IPPROTO_UDP,
445 csum_partial(udph, udp_len, 0));
446 if (udph->check == 0)
447 udph->check = CSUM_MANGLED_0;
448
449 skb_push(skb, sizeof(*iph));
450 skb_reset_network_header(skb);
451 iph = ip_hdr(skb);
452
453 /* iph->version = 4; iph->ihl = 5; */
454 put_unaligned(0x45, (unsigned char *)iph);
455 iph->tos = 0;
456 put_unaligned(htons(ip_len), &(iph->tot_len));
457 iph->id = htons(atomic_inc_return(&ip_ident));
458 iph->frag_off = 0;
459 iph->ttl = 64;
460 iph->protocol = IPPROTO_UDP;
461 iph->check = 0;
462 put_unaligned(np->local_ip.ip, &(iph->saddr));
463 put_unaligned(np->remote_ip.ip, &(iph->daddr));
464 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl);
465
466 eth = (struct ethhdr *) skb_push(skb, ETH_HLEN);
467 skb_reset_mac_header(skb);
468 skb->protocol = eth->h_proto = htons(ETH_P_IP);
469 }
470
471 ether_addr_copy(eth->h_source, np->dev->dev_addr);
472 ether_addr_copy(eth->h_dest, np->remote_mac);
473
474 skb->dev = np->dev;
475
476 netpoll_send_skb(np, skb);
477 }
478 EXPORT_SYMBOL(netpoll_send_udp);
479
netpoll_print_options(struct netpoll * np)480 void netpoll_print_options(struct netpoll *np)
481 {
482 np_info(np, "local port %d\n", np->local_port);
483 if (np->ipv6)
484 np_info(np, "local IPv6 address %pI6c\n", &np->local_ip.in6);
485 else
486 np_info(np, "local IPv4 address %pI4\n", &np->local_ip.ip);
487 np_info(np, "interface '%s'\n", np->dev_name);
488 np_info(np, "remote port %d\n", np->remote_port);
489 if (np->ipv6)
490 np_info(np, "remote IPv6 address %pI6c\n", &np->remote_ip.in6);
491 else
492 np_info(np, "remote IPv4 address %pI4\n", &np->remote_ip.ip);
493 np_info(np, "remote ethernet address %pM\n", np->remote_mac);
494 }
495 EXPORT_SYMBOL(netpoll_print_options);
496
netpoll_parse_ip_addr(const char * str,union inet_addr * addr)497 static int netpoll_parse_ip_addr(const char *str, union inet_addr *addr)
498 {
499 const char *end;
500
501 if (!strchr(str, ':') &&
502 in4_pton(str, -1, (void *)addr, -1, &end) > 0) {
503 if (!*end)
504 return 0;
505 }
506 if (in6_pton(str, -1, addr->in6.s6_addr, -1, &end) > 0) {
507 #if IS_ENABLED(CONFIG_IPV6)
508 if (!*end)
509 return 1;
510 #else
511 return -1;
512 #endif
513 }
514 return -1;
515 }
516
netpoll_parse_options(struct netpoll * np,char * opt)517 int netpoll_parse_options(struct netpoll *np, char *opt)
518 {
519 char *cur=opt, *delim;
520 int ipv6;
521 bool ipversion_set = false;
522
523 if (*cur != '@') {
524 if ((delim = strchr(cur, '@')) == NULL)
525 goto parse_failed;
526 *delim = 0;
527 if (kstrtou16(cur, 10, &np->local_port))
528 goto parse_failed;
529 cur = delim;
530 }
531 cur++;
532
533 if (*cur != '/') {
534 ipversion_set = true;
535 if ((delim = strchr(cur, '/')) == NULL)
536 goto parse_failed;
537 *delim = 0;
538 ipv6 = netpoll_parse_ip_addr(cur, &np->local_ip);
539 if (ipv6 < 0)
540 goto parse_failed;
541 else
542 np->ipv6 = (bool)ipv6;
543 cur = delim;
544 }
545 cur++;
546
547 if (*cur != ',') {
548 /* parse out dev name */
549 if ((delim = strchr(cur, ',')) == NULL)
550 goto parse_failed;
551 *delim = 0;
552 strlcpy(np->dev_name, cur, sizeof(np->dev_name));
553 cur = delim;
554 }
555 cur++;
556
557 if (*cur != '@') {
558 /* dst port */
559 if ((delim = strchr(cur, '@')) == NULL)
560 goto parse_failed;
561 *delim = 0;
562 if (*cur == ' ' || *cur == '\t')
563 np_info(np, "warning: whitespace is not allowed\n");
564 if (kstrtou16(cur, 10, &np->remote_port))
565 goto parse_failed;
566 cur = delim;
567 }
568 cur++;
569
570 /* dst ip */
571 if ((delim = strchr(cur, '/')) == NULL)
572 goto parse_failed;
573 *delim = 0;
574 ipv6 = netpoll_parse_ip_addr(cur, &np->remote_ip);
575 if (ipv6 < 0)
576 goto parse_failed;
577 else if (ipversion_set && np->ipv6 != (bool)ipv6)
578 goto parse_failed;
579 else
580 np->ipv6 = (bool)ipv6;
581 cur = delim + 1;
582
583 if (*cur != 0) {
584 /* MAC address */
585 if (!mac_pton(cur, np->remote_mac))
586 goto parse_failed;
587 }
588
589 netpoll_print_options(np);
590
591 return 0;
592
593 parse_failed:
594 np_info(np, "couldn't parse config at '%s'!\n", cur);
595 return -1;
596 }
597 EXPORT_SYMBOL(netpoll_parse_options);
598
__netpoll_setup(struct netpoll * np,struct net_device * ndev)599 int __netpoll_setup(struct netpoll *np, struct net_device *ndev)
600 {
601 struct netpoll_info *npinfo;
602 const struct net_device_ops *ops;
603 int err;
604
605 np->dev = ndev;
606 strlcpy(np->dev_name, ndev->name, IFNAMSIZ);
607 INIT_WORK(&np->cleanup_work, netpoll_async_cleanup);
608
609 if ((ndev->priv_flags & IFF_DISABLE_NETPOLL) ||
610 !ndev->netdev_ops->ndo_poll_controller) {
611 np_err(np, "%s doesn't support polling, aborting\n",
612 np->dev_name);
613 err = -ENOTSUPP;
614 goto out;
615 }
616
617 if (!ndev->npinfo) {
618 npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL);
619 if (!npinfo) {
620 err = -ENOMEM;
621 goto out;
622 }
623
624 sema_init(&npinfo->dev_lock, 1);
625 skb_queue_head_init(&npinfo->txq);
626 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process);
627
628 atomic_set(&npinfo->refcnt, 1);
629
630 ops = np->dev->netdev_ops;
631 if (ops->ndo_netpoll_setup) {
632 err = ops->ndo_netpoll_setup(ndev, npinfo);
633 if (err)
634 goto free_npinfo;
635 }
636 } else {
637 npinfo = rtnl_dereference(ndev->npinfo);
638 atomic_inc(&npinfo->refcnt);
639 }
640
641 npinfo->netpoll = np;
642
643 /* last thing to do is link it to the net device structure */
644 rcu_assign_pointer(ndev->npinfo, npinfo);
645
646 return 0;
647
648 free_npinfo:
649 kfree(npinfo);
650 out:
651 return err;
652 }
653 EXPORT_SYMBOL_GPL(__netpoll_setup);
654
netpoll_setup(struct netpoll * np)655 int netpoll_setup(struct netpoll *np)
656 {
657 struct net_device *ndev = NULL;
658 struct in_device *in_dev;
659 int err;
660
661 rtnl_lock();
662 if (np->dev_name) {
663 struct net *net = current->nsproxy->net_ns;
664 ndev = __dev_get_by_name(net, np->dev_name);
665 }
666 if (!ndev) {
667 np_err(np, "%s doesn't exist, aborting\n", np->dev_name);
668 err = -ENODEV;
669 goto unlock;
670 }
671 dev_hold(ndev);
672
673 if (netdev_master_upper_dev_get(ndev)) {
674 np_err(np, "%s is a slave device, aborting\n", np->dev_name);
675 err = -EBUSY;
676 goto put;
677 }
678
679 if (!netif_running(ndev)) {
680 unsigned long atmost, atleast;
681
682 np_info(np, "device %s not up yet, forcing it\n", np->dev_name);
683
684 err = dev_open(ndev);
685
686 if (err) {
687 np_err(np, "failed to open %s\n", ndev->name);
688 goto put;
689 }
690
691 rtnl_unlock();
692 atleast = jiffies + HZ/10;
693 atmost = jiffies + carrier_timeout * HZ;
694 while (!netif_carrier_ok(ndev)) {
695 if (time_after(jiffies, atmost)) {
696 np_notice(np, "timeout waiting for carrier\n");
697 break;
698 }
699 msleep(1);
700 }
701
702 /* If carrier appears to come up instantly, we don't
703 * trust it and pause so that we don't pump all our
704 * queued console messages into the bitbucket.
705 */
706
707 if (time_before(jiffies, atleast)) {
708 np_notice(np, "carrier detect appears untrustworthy, waiting 4 seconds\n");
709 msleep(4000);
710 }
711 rtnl_lock();
712 }
713
714 if (!np->local_ip.ip) {
715 if (!np->ipv6) {
716 in_dev = __in_dev_get_rtnl(ndev);
717
718 if (!in_dev || !in_dev->ifa_list) {
719 np_err(np, "no IP address for %s, aborting\n",
720 np->dev_name);
721 err = -EDESTADDRREQ;
722 goto put;
723 }
724
725 np->local_ip.ip = in_dev->ifa_list->ifa_local;
726 np_info(np, "local IP %pI4\n", &np->local_ip.ip);
727 } else {
728 #if IS_ENABLED(CONFIG_IPV6)
729 struct inet6_dev *idev;
730
731 err = -EDESTADDRREQ;
732 idev = __in6_dev_get(ndev);
733 if (idev) {
734 struct inet6_ifaddr *ifp;
735
736 read_lock_bh(&idev->lock);
737 list_for_each_entry(ifp, &idev->addr_list, if_list) {
738 if (ipv6_addr_type(&ifp->addr) & IPV6_ADDR_LINKLOCAL)
739 continue;
740 np->local_ip.in6 = ifp->addr;
741 err = 0;
742 break;
743 }
744 read_unlock_bh(&idev->lock);
745 }
746 if (err) {
747 np_err(np, "no IPv6 address for %s, aborting\n",
748 np->dev_name);
749 goto put;
750 } else
751 np_info(np, "local IPv6 %pI6c\n", &np->local_ip.in6);
752 #else
753 np_err(np, "IPv6 is not supported %s, aborting\n",
754 np->dev_name);
755 err = -EINVAL;
756 goto put;
757 #endif
758 }
759 }
760
761 /* fill up the skb queue */
762 refill_skbs();
763
764 err = __netpoll_setup(np, ndev);
765 if (err)
766 goto put;
767
768 rtnl_unlock();
769 return 0;
770
771 put:
772 dev_put(ndev);
773 unlock:
774 rtnl_unlock();
775 return err;
776 }
777 EXPORT_SYMBOL(netpoll_setup);
778
netpoll_init(void)779 static int __init netpoll_init(void)
780 {
781 skb_queue_head_init(&skb_pool);
782 return 0;
783 }
784 core_initcall(netpoll_init);
785
rcu_cleanup_netpoll_info(struct rcu_head * rcu_head)786 static void rcu_cleanup_netpoll_info(struct rcu_head *rcu_head)
787 {
788 struct netpoll_info *npinfo =
789 container_of(rcu_head, struct netpoll_info, rcu);
790
791 skb_queue_purge(&npinfo->txq);
792
793 /* we can't call cancel_delayed_work_sync here, as we are in softirq */
794 cancel_delayed_work(&npinfo->tx_work);
795
796 /* clean after last, unfinished work */
797 __skb_queue_purge(&npinfo->txq);
798 /* now cancel it again */
799 cancel_delayed_work(&npinfo->tx_work);
800 kfree(npinfo);
801 }
802
__netpoll_cleanup(struct netpoll * np)803 void __netpoll_cleanup(struct netpoll *np)
804 {
805 struct netpoll_info *npinfo;
806
807 /* rtnl_dereference would be preferable here but
808 * rcu_cleanup_netpoll path can put us in here safely without
809 * holding the rtnl, so plain rcu_dereference it is
810 */
811 npinfo = rtnl_dereference(np->dev->npinfo);
812 if (!npinfo)
813 return;
814
815 synchronize_srcu(&netpoll_srcu);
816
817 if (atomic_dec_and_test(&npinfo->refcnt)) {
818 const struct net_device_ops *ops;
819
820 ops = np->dev->netdev_ops;
821 if (ops->ndo_netpoll_cleanup)
822 ops->ndo_netpoll_cleanup(np->dev);
823
824 RCU_INIT_POINTER(np->dev->npinfo, NULL);
825 call_rcu_bh(&npinfo->rcu, rcu_cleanup_netpoll_info);
826 } else
827 RCU_INIT_POINTER(np->dev->npinfo, NULL);
828 }
829 EXPORT_SYMBOL_GPL(__netpoll_cleanup);
830
netpoll_async_cleanup(struct work_struct * work)831 static void netpoll_async_cleanup(struct work_struct *work)
832 {
833 struct netpoll *np = container_of(work, struct netpoll, cleanup_work);
834
835 rtnl_lock();
836 __netpoll_cleanup(np);
837 rtnl_unlock();
838 kfree(np);
839 }
840
__netpoll_free_async(struct netpoll * np)841 void __netpoll_free_async(struct netpoll *np)
842 {
843 schedule_work(&np->cleanup_work);
844 }
845 EXPORT_SYMBOL_GPL(__netpoll_free_async);
846
netpoll_cleanup(struct netpoll * np)847 void netpoll_cleanup(struct netpoll *np)
848 {
849 rtnl_lock();
850 if (!np->dev)
851 goto out;
852 __netpoll_cleanup(np);
853 dev_put(np->dev);
854 np->dev = NULL;
855 out:
856 rtnl_unlock();
857 }
858 EXPORT_SYMBOL(netpoll_cleanup);
859