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/dsa.h>
33 #include <net/tcp.h>
34 #include <net/udp.h>
35 #include <net/addrconf.h>
36 #include <net/ndisc.h>
37 #include <net/ip6_checksum.h>
38 #include <asm/unaligned.h>
39 #include <trace/events/napi.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
netpoll_start_xmit(struct sk_buff * skb,struct net_device * dev,struct netdev_queue * txq)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
queue_process(struct work_struct * work)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
poll_one_napi(struct napi_struct * napi)140 static void poll_one_napi(struct napi_struct *napi)
141 {
142 int work;
143
144 /* If we set this bit but see that it has already been set,
145 * that indicates that napi has been disabled and we need
146 * to abort this operation
147 */
148 if (test_and_set_bit(NAPI_STATE_NPSVC, &napi->state))
149 return;
150
151 /* We explicilty pass the polling call a budget of 0 to
152 * indicate that we are clearing the Tx path only.
153 */
154 work = napi->poll(napi, 0);
155 WARN_ONCE(work, "%pS exceeded budget in poll\n", napi->poll);
156 trace_napi_poll(napi, work, 0);
157
158 clear_bit(NAPI_STATE_NPSVC, &napi->state);
159 }
160
poll_napi(struct net_device * dev)161 static void poll_napi(struct net_device *dev)
162 {
163 struct napi_struct *napi;
164 int cpu = smp_processor_id();
165
166 list_for_each_entry_rcu(napi, &dev->napi_list, dev_list) {
167 if (cmpxchg(&napi->poll_owner, -1, cpu) == -1) {
168 poll_one_napi(napi);
169 smp_store_release(&napi->poll_owner, -1);
170 }
171 }
172 }
173
netpoll_poll_dev(struct net_device * dev)174 void netpoll_poll_dev(struct net_device *dev)
175 {
176 struct netpoll_info *ni = rcu_dereference_bh(dev->npinfo);
177 const struct net_device_ops *ops;
178
179 /* Don't do any rx activity if the dev_lock mutex is held
180 * the dev_open/close paths use this to block netpoll activity
181 * while changing device state
182 */
183 if (!ni || down_trylock(&ni->dev_lock))
184 return;
185
186 if (!netif_running(dev)) {
187 up(&ni->dev_lock);
188 return;
189 }
190
191 ops = dev->netdev_ops;
192 if (ops->ndo_poll_controller)
193 ops->ndo_poll_controller(dev);
194
195 poll_napi(dev);
196
197 up(&ni->dev_lock);
198
199 zap_completion_queue();
200 }
201 EXPORT_SYMBOL(netpoll_poll_dev);
202
netpoll_poll_disable(struct net_device * dev)203 void netpoll_poll_disable(struct net_device *dev)
204 {
205 struct netpoll_info *ni;
206 int idx;
207 might_sleep();
208 idx = srcu_read_lock(&netpoll_srcu);
209 ni = srcu_dereference(dev->npinfo, &netpoll_srcu);
210 if (ni)
211 down(&ni->dev_lock);
212 srcu_read_unlock(&netpoll_srcu, idx);
213 }
214 EXPORT_SYMBOL(netpoll_poll_disable);
215
netpoll_poll_enable(struct net_device * dev)216 void netpoll_poll_enable(struct net_device *dev)
217 {
218 struct netpoll_info *ni;
219 rcu_read_lock();
220 ni = rcu_dereference(dev->npinfo);
221 if (ni)
222 up(&ni->dev_lock);
223 rcu_read_unlock();
224 }
225 EXPORT_SYMBOL(netpoll_poll_enable);
226
refill_skbs(void)227 static void refill_skbs(void)
228 {
229 struct sk_buff *skb;
230 unsigned long flags;
231
232 spin_lock_irqsave(&skb_pool.lock, flags);
233 while (skb_pool.qlen < MAX_SKBS) {
234 skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC);
235 if (!skb)
236 break;
237
238 __skb_queue_tail(&skb_pool, skb);
239 }
240 spin_unlock_irqrestore(&skb_pool.lock, flags);
241 }
242
zap_completion_queue(void)243 static void zap_completion_queue(void)
244 {
245 unsigned long flags;
246 struct softnet_data *sd = &get_cpu_var(softnet_data);
247
248 if (sd->completion_queue) {
249 struct sk_buff *clist;
250
251 local_irq_save(flags);
252 clist = sd->completion_queue;
253 sd->completion_queue = NULL;
254 local_irq_restore(flags);
255
256 while (clist != NULL) {
257 struct sk_buff *skb = clist;
258 clist = clist->next;
259 if (!skb_irq_freeable(skb)) {
260 refcount_set(&skb->users, 1);
261 dev_kfree_skb_any(skb); /* put this one back */
262 } else {
263 __kfree_skb(skb);
264 }
265 }
266 }
267
268 put_cpu_var(softnet_data);
269 }
270
find_skb(struct netpoll * np,int len,int reserve)271 static struct sk_buff *find_skb(struct netpoll *np, int len, int reserve)
272 {
273 int count = 0;
274 struct sk_buff *skb;
275
276 zap_completion_queue();
277 refill_skbs();
278 repeat:
279
280 skb = alloc_skb(len, GFP_ATOMIC);
281 if (!skb)
282 skb = skb_dequeue(&skb_pool);
283
284 if (!skb) {
285 if (++count < 10) {
286 netpoll_poll_dev(np->dev);
287 goto repeat;
288 }
289 return NULL;
290 }
291
292 refcount_set(&skb->users, 1);
293 skb_reserve(skb, reserve);
294 return skb;
295 }
296
netpoll_owner_active(struct net_device * dev)297 static int netpoll_owner_active(struct net_device *dev)
298 {
299 struct napi_struct *napi;
300
301 list_for_each_entry_rcu(napi, &dev->napi_list, dev_list) {
302 if (napi->poll_owner == smp_processor_id())
303 return 1;
304 }
305 return 0;
306 }
307
308 /* call with IRQ disabled */
__netpoll_send_skb(struct netpoll * np,struct sk_buff * skb)309 static netdev_tx_t __netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
310 {
311 netdev_tx_t status = NETDEV_TX_BUSY;
312 struct net_device *dev;
313 unsigned long tries;
314 /* It is up to the caller to keep npinfo alive. */
315 struct netpoll_info *npinfo;
316
317 lockdep_assert_irqs_disabled();
318
319 dev = np->dev;
320 npinfo = rcu_dereference_bh(dev->npinfo);
321
322 if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) {
323 dev_kfree_skb_irq(skb);
324 return NET_XMIT_DROP;
325 }
326
327 /* don't get messages out of order, and no recursion */
328 if (skb_queue_len(&npinfo->txq) == 0 && !netpoll_owner_active(dev)) {
329 struct netdev_queue *txq;
330
331 txq = netdev_core_pick_tx(dev, skb, NULL);
332
333 /* try until next clock tick */
334 for (tries = jiffies_to_usecs(1)/USEC_PER_POLL;
335 tries > 0; --tries) {
336 if (HARD_TX_TRYLOCK(dev, txq)) {
337 if (!netif_xmit_stopped(txq))
338 status = netpoll_start_xmit(skb, dev, txq);
339
340 HARD_TX_UNLOCK(dev, txq);
341
342 if (dev_xmit_complete(status))
343 break;
344
345 }
346
347 /* tickle device maybe there is some cleanup */
348 netpoll_poll_dev(np->dev);
349
350 udelay(USEC_PER_POLL);
351 }
352
353 WARN_ONCE(!irqs_disabled(),
354 "netpoll_send_skb_on_dev(): %s enabled interrupts in poll (%pS)\n",
355 dev->name, dev->netdev_ops->ndo_start_xmit);
356
357 }
358
359 if (!dev_xmit_complete(status)) {
360 skb_queue_tail(&npinfo->txq, skb);
361 schedule_delayed_work(&npinfo->tx_work,0);
362 }
363 return NETDEV_TX_OK;
364 }
365
netpoll_send_skb(struct netpoll * np,struct sk_buff * skb)366 netdev_tx_t netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
367 {
368 unsigned long flags;
369 netdev_tx_t ret;
370
371 if (unlikely(!np)) {
372 dev_kfree_skb_irq(skb);
373 ret = NET_XMIT_DROP;
374 } else {
375 local_irq_save(flags);
376 ret = __netpoll_send_skb(np, skb);
377 local_irq_restore(flags);
378 }
379 return ret;
380 }
381 EXPORT_SYMBOL(netpoll_send_skb);
382
netpoll_send_udp(struct netpoll * np,const char * msg,int len)383 void netpoll_send_udp(struct netpoll *np, const char *msg, int len)
384 {
385 int total_len, ip_len, udp_len;
386 struct sk_buff *skb;
387 struct udphdr *udph;
388 struct iphdr *iph;
389 struct ethhdr *eth;
390 static atomic_t ip_ident;
391 struct ipv6hdr *ip6h;
392
393 WARN_ON_ONCE(!irqs_disabled());
394
395 udp_len = len + sizeof(*udph);
396 if (np->ipv6)
397 ip_len = udp_len + sizeof(*ip6h);
398 else
399 ip_len = udp_len + sizeof(*iph);
400
401 total_len = ip_len + LL_RESERVED_SPACE(np->dev);
402
403 skb = find_skb(np, total_len + np->dev->needed_tailroom,
404 total_len - len);
405 if (!skb)
406 return;
407
408 skb_copy_to_linear_data(skb, msg, len);
409 skb_put(skb, len);
410
411 skb_push(skb, sizeof(*udph));
412 skb_reset_transport_header(skb);
413 udph = udp_hdr(skb);
414 udph->source = htons(np->local_port);
415 udph->dest = htons(np->remote_port);
416 udph->len = htons(udp_len);
417
418 if (np->ipv6) {
419 udph->check = 0;
420 udph->check = csum_ipv6_magic(&np->local_ip.in6,
421 &np->remote_ip.in6,
422 udp_len, IPPROTO_UDP,
423 csum_partial(udph, udp_len, 0));
424 if (udph->check == 0)
425 udph->check = CSUM_MANGLED_0;
426
427 skb_push(skb, sizeof(*ip6h));
428 skb_reset_network_header(skb);
429 ip6h = ipv6_hdr(skb);
430
431 /* ip6h->version = 6; ip6h->priority = 0; */
432 put_unaligned(0x60, (unsigned char *)ip6h);
433 ip6h->flow_lbl[0] = 0;
434 ip6h->flow_lbl[1] = 0;
435 ip6h->flow_lbl[2] = 0;
436
437 ip6h->payload_len = htons(sizeof(struct udphdr) + len);
438 ip6h->nexthdr = IPPROTO_UDP;
439 ip6h->hop_limit = 32;
440 ip6h->saddr = np->local_ip.in6;
441 ip6h->daddr = np->remote_ip.in6;
442
443 eth = skb_push(skb, ETH_HLEN);
444 skb_reset_mac_header(skb);
445 skb->protocol = eth->h_proto = htons(ETH_P_IPV6);
446 } else {
447 udph->check = 0;
448 udph->check = csum_tcpudp_magic(np->local_ip.ip,
449 np->remote_ip.ip,
450 udp_len, IPPROTO_UDP,
451 csum_partial(udph, udp_len, 0));
452 if (udph->check == 0)
453 udph->check = CSUM_MANGLED_0;
454
455 skb_push(skb, sizeof(*iph));
456 skb_reset_network_header(skb);
457 iph = ip_hdr(skb);
458
459 /* iph->version = 4; iph->ihl = 5; */
460 put_unaligned(0x45, (unsigned char *)iph);
461 iph->tos = 0;
462 put_unaligned(htons(ip_len), &(iph->tot_len));
463 iph->id = htons(atomic_inc_return(&ip_ident));
464 iph->frag_off = 0;
465 iph->ttl = 64;
466 iph->protocol = IPPROTO_UDP;
467 iph->check = 0;
468 put_unaligned(np->local_ip.ip, &(iph->saddr));
469 put_unaligned(np->remote_ip.ip, &(iph->daddr));
470 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl);
471
472 eth = skb_push(skb, ETH_HLEN);
473 skb_reset_mac_header(skb);
474 skb->protocol = eth->h_proto = htons(ETH_P_IP);
475 }
476
477 ether_addr_copy(eth->h_source, np->dev->dev_addr);
478 ether_addr_copy(eth->h_dest, np->remote_mac);
479
480 skb->dev = np->dev;
481
482 netpoll_send_skb(np, skb);
483 }
484 EXPORT_SYMBOL(netpoll_send_udp);
485
netpoll_print_options(struct netpoll * np)486 void netpoll_print_options(struct netpoll *np)
487 {
488 np_info(np, "local port %d\n", np->local_port);
489 if (np->ipv6)
490 np_info(np, "local IPv6 address %pI6c\n", &np->local_ip.in6);
491 else
492 np_info(np, "local IPv4 address %pI4\n", &np->local_ip.ip);
493 np_info(np, "interface '%s'\n", np->dev_name);
494 np_info(np, "remote port %d\n", np->remote_port);
495 if (np->ipv6)
496 np_info(np, "remote IPv6 address %pI6c\n", &np->remote_ip.in6);
497 else
498 np_info(np, "remote IPv4 address %pI4\n", &np->remote_ip.ip);
499 np_info(np, "remote ethernet address %pM\n", np->remote_mac);
500 }
501 EXPORT_SYMBOL(netpoll_print_options);
502
netpoll_parse_ip_addr(const char * str,union inet_addr * addr)503 static int netpoll_parse_ip_addr(const char *str, union inet_addr *addr)
504 {
505 const char *end;
506
507 if (!strchr(str, ':') &&
508 in4_pton(str, -1, (void *)addr, -1, &end) > 0) {
509 if (!*end)
510 return 0;
511 }
512 if (in6_pton(str, -1, addr->in6.s6_addr, -1, &end) > 0) {
513 #if IS_ENABLED(CONFIG_IPV6)
514 if (!*end)
515 return 1;
516 #else
517 return -1;
518 #endif
519 }
520 return -1;
521 }
522
netpoll_parse_options(struct netpoll * np,char * opt)523 int netpoll_parse_options(struct netpoll *np, char *opt)
524 {
525 char *cur=opt, *delim;
526 int ipv6;
527 bool ipversion_set = false;
528
529 if (*cur != '@') {
530 if ((delim = strchr(cur, '@')) == NULL)
531 goto parse_failed;
532 *delim = 0;
533 if (kstrtou16(cur, 10, &np->local_port))
534 goto parse_failed;
535 cur = delim;
536 }
537 cur++;
538
539 if (*cur != '/') {
540 ipversion_set = true;
541 if ((delim = strchr(cur, '/')) == NULL)
542 goto parse_failed;
543 *delim = 0;
544 ipv6 = netpoll_parse_ip_addr(cur, &np->local_ip);
545 if (ipv6 < 0)
546 goto parse_failed;
547 else
548 np->ipv6 = (bool)ipv6;
549 cur = delim;
550 }
551 cur++;
552
553 if (*cur != ',') {
554 /* parse out dev name */
555 if ((delim = strchr(cur, ',')) == NULL)
556 goto parse_failed;
557 *delim = 0;
558 strlcpy(np->dev_name, cur, sizeof(np->dev_name));
559 cur = delim;
560 }
561 cur++;
562
563 if (*cur != '@') {
564 /* dst port */
565 if ((delim = strchr(cur, '@')) == NULL)
566 goto parse_failed;
567 *delim = 0;
568 if (*cur == ' ' || *cur == '\t')
569 np_info(np, "warning: whitespace is not allowed\n");
570 if (kstrtou16(cur, 10, &np->remote_port))
571 goto parse_failed;
572 cur = delim;
573 }
574 cur++;
575
576 /* dst ip */
577 if ((delim = strchr(cur, '/')) == NULL)
578 goto parse_failed;
579 *delim = 0;
580 ipv6 = netpoll_parse_ip_addr(cur, &np->remote_ip);
581 if (ipv6 < 0)
582 goto parse_failed;
583 else if (ipversion_set && np->ipv6 != (bool)ipv6)
584 goto parse_failed;
585 else
586 np->ipv6 = (bool)ipv6;
587 cur = delim + 1;
588
589 if (*cur != 0) {
590 /* MAC address */
591 if (!mac_pton(cur, np->remote_mac))
592 goto parse_failed;
593 }
594
595 netpoll_print_options(np);
596
597 return 0;
598
599 parse_failed:
600 np_info(np, "couldn't parse config at '%s'!\n", cur);
601 return -1;
602 }
603 EXPORT_SYMBOL(netpoll_parse_options);
604
__netpoll_setup(struct netpoll * np,struct net_device * ndev)605 int __netpoll_setup(struct netpoll *np, struct net_device *ndev)
606 {
607 struct netpoll_info *npinfo;
608 const struct net_device_ops *ops;
609 int err;
610
611 np->dev = ndev;
612 strlcpy(np->dev_name, ndev->name, IFNAMSIZ);
613
614 if (ndev->priv_flags & IFF_DISABLE_NETPOLL) {
615 np_err(np, "%s doesn't support polling, aborting\n",
616 np->dev_name);
617 err = -ENOTSUPP;
618 goto out;
619 }
620
621 if (!ndev->npinfo) {
622 npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL);
623 if (!npinfo) {
624 err = -ENOMEM;
625 goto out;
626 }
627
628 sema_init(&npinfo->dev_lock, 1);
629 skb_queue_head_init(&npinfo->txq);
630 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process);
631
632 refcount_set(&npinfo->refcnt, 1);
633
634 ops = np->dev->netdev_ops;
635 if (ops->ndo_netpoll_setup) {
636 err = ops->ndo_netpoll_setup(ndev, npinfo);
637 if (err)
638 goto free_npinfo;
639 }
640 } else {
641 npinfo = rtnl_dereference(ndev->npinfo);
642 refcount_inc(&npinfo->refcnt);
643 }
644
645 npinfo->netpoll = np;
646
647 /* last thing to do is link it to the net device structure */
648 rcu_assign_pointer(ndev->npinfo, npinfo);
649
650 return 0;
651
652 free_npinfo:
653 kfree(npinfo);
654 out:
655 return err;
656 }
657 EXPORT_SYMBOL_GPL(__netpoll_setup);
658
netpoll_setup(struct netpoll * np)659 int netpoll_setup(struct netpoll *np)
660 {
661 struct net_device *ndev = NULL, *dev = NULL;
662 struct net *net = current->nsproxy->net_ns;
663 struct in_device *in_dev;
664 int err;
665
666 rtnl_lock();
667 if (np->dev_name[0])
668 ndev = __dev_get_by_name(net, np->dev_name);
669
670 if (!ndev) {
671 np_err(np, "%s doesn't exist, aborting\n", np->dev_name);
672 err = -ENODEV;
673 goto unlock;
674 }
675 dev_hold(ndev);
676
677 /* bring up DSA management network devices up first */
678 for_each_netdev(net, dev) {
679 if (!netdev_uses_dsa(dev))
680 continue;
681
682 err = dev_change_flags(dev, dev->flags | IFF_UP, NULL);
683 if (err < 0) {
684 np_err(np, "%s failed to open %s\n",
685 np->dev_name, dev->name);
686 goto put;
687 }
688 }
689
690 if (netdev_master_upper_dev_get(ndev)) {
691 np_err(np, "%s is a slave device, aborting\n", np->dev_name);
692 err = -EBUSY;
693 goto put;
694 }
695
696 if (!netif_running(ndev)) {
697 unsigned long atmost, atleast;
698
699 np_info(np, "device %s not up yet, forcing it\n", np->dev_name);
700
701 err = dev_open(ndev, NULL);
702
703 if (err) {
704 np_err(np, "failed to open %s\n", ndev->name);
705 goto put;
706 }
707
708 rtnl_unlock();
709 atleast = jiffies + HZ/10;
710 atmost = jiffies + carrier_timeout * HZ;
711 while (!netif_carrier_ok(ndev)) {
712 if (time_after(jiffies, atmost)) {
713 np_notice(np, "timeout waiting for carrier\n");
714 break;
715 }
716 msleep(1);
717 }
718
719 /* If carrier appears to come up instantly, we don't
720 * trust it and pause so that we don't pump all our
721 * queued console messages into the bitbucket.
722 */
723
724 if (time_before(jiffies, atleast)) {
725 np_notice(np, "carrier detect appears untrustworthy, waiting 4 seconds\n");
726 msleep(4000);
727 }
728 rtnl_lock();
729 }
730
731 if (!np->local_ip.ip) {
732 if (!np->ipv6) {
733 const struct in_ifaddr *ifa;
734
735 in_dev = __in_dev_get_rtnl(ndev);
736 if (!in_dev)
737 goto put_noaddr;
738
739 ifa = rtnl_dereference(in_dev->ifa_list);
740 if (!ifa) {
741 put_noaddr:
742 np_err(np, "no IP address for %s, aborting\n",
743 np->dev_name);
744 err = -EDESTADDRREQ;
745 goto put;
746 }
747
748 np->local_ip.ip = ifa->ifa_local;
749 np_info(np, "local IP %pI4\n", &np->local_ip.ip);
750 } else {
751 #if IS_ENABLED(CONFIG_IPV6)
752 struct inet6_dev *idev;
753
754 err = -EDESTADDRREQ;
755 idev = __in6_dev_get(ndev);
756 if (idev) {
757 struct inet6_ifaddr *ifp;
758
759 read_lock_bh(&idev->lock);
760 list_for_each_entry(ifp, &idev->addr_list, if_list) {
761 if (!!(ipv6_addr_type(&ifp->addr) & IPV6_ADDR_LINKLOCAL) !=
762 !!(ipv6_addr_type(&np->remote_ip.in6) & IPV6_ADDR_LINKLOCAL))
763 continue;
764 np->local_ip.in6 = ifp->addr;
765 err = 0;
766 break;
767 }
768 read_unlock_bh(&idev->lock);
769 }
770 if (err) {
771 np_err(np, "no IPv6 address for %s, aborting\n",
772 np->dev_name);
773 goto put;
774 } else
775 np_info(np, "local IPv6 %pI6c\n", &np->local_ip.in6);
776 #else
777 np_err(np, "IPv6 is not supported %s, aborting\n",
778 np->dev_name);
779 err = -EINVAL;
780 goto put;
781 #endif
782 }
783 }
784
785 /* fill up the skb queue */
786 refill_skbs();
787
788 err = __netpoll_setup(np, ndev);
789 if (err)
790 goto put;
791
792 rtnl_unlock();
793 return 0;
794
795 put:
796 dev_put(ndev);
797 unlock:
798 rtnl_unlock();
799 return err;
800 }
801 EXPORT_SYMBOL(netpoll_setup);
802
netpoll_init(void)803 static int __init netpoll_init(void)
804 {
805 skb_queue_head_init(&skb_pool);
806 return 0;
807 }
808 core_initcall(netpoll_init);
809
rcu_cleanup_netpoll_info(struct rcu_head * rcu_head)810 static void rcu_cleanup_netpoll_info(struct rcu_head *rcu_head)
811 {
812 struct netpoll_info *npinfo =
813 container_of(rcu_head, struct netpoll_info, rcu);
814
815 skb_queue_purge(&npinfo->txq);
816
817 /* we can't call cancel_delayed_work_sync here, as we are in softirq */
818 cancel_delayed_work(&npinfo->tx_work);
819
820 /* clean after last, unfinished work */
821 __skb_queue_purge(&npinfo->txq);
822 /* now cancel it again */
823 cancel_delayed_work(&npinfo->tx_work);
824 kfree(npinfo);
825 }
826
__netpoll_cleanup(struct netpoll * np)827 void __netpoll_cleanup(struct netpoll *np)
828 {
829 struct netpoll_info *npinfo;
830
831 npinfo = rtnl_dereference(np->dev->npinfo);
832 if (!npinfo)
833 return;
834
835 synchronize_srcu(&netpoll_srcu);
836
837 if (refcount_dec_and_test(&npinfo->refcnt)) {
838 const struct net_device_ops *ops;
839
840 ops = np->dev->netdev_ops;
841 if (ops->ndo_netpoll_cleanup)
842 ops->ndo_netpoll_cleanup(np->dev);
843
844 RCU_INIT_POINTER(np->dev->npinfo, NULL);
845 call_rcu(&npinfo->rcu, rcu_cleanup_netpoll_info);
846 } else
847 RCU_INIT_POINTER(np->dev->npinfo, NULL);
848 }
849 EXPORT_SYMBOL_GPL(__netpoll_cleanup);
850
__netpoll_free(struct netpoll * np)851 void __netpoll_free(struct netpoll *np)
852 {
853 ASSERT_RTNL();
854
855 /* Wait for transmitting packets to finish before freeing. */
856 synchronize_rcu();
857 __netpoll_cleanup(np);
858 kfree(np);
859 }
860 EXPORT_SYMBOL_GPL(__netpoll_free);
861
netpoll_cleanup(struct netpoll * np)862 void netpoll_cleanup(struct netpoll *np)
863 {
864 rtnl_lock();
865 if (!np->dev)
866 goto out;
867 __netpoll_cleanup(np);
868 dev_put(np->dev);
869 np->dev = NULL;
870 out:
871 rtnl_unlock();
872 }
873 EXPORT_SYMBOL(netpoll_cleanup);
874