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 <linux/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 #define USEC_PER_POLL 50
49
50 #define MAX_SKB_SIZE \
51 (sizeof(struct ethhdr) + \
52 sizeof(struct iphdr) + \
53 sizeof(struct udphdr) + \
54 MAX_UDP_CHUNK)
55
56 static void zap_completion_queue(void);
57
58 static unsigned int carrier_timeout = 4;
59 module_param(carrier_timeout, uint, 0644);
60
61 #define np_info(np, fmt, ...) \
62 pr_info("%s: " fmt, np->name, ##__VA_ARGS__)
63 #define np_err(np, fmt, ...) \
64 pr_err("%s: " fmt, np->name, ##__VA_ARGS__)
65 #define np_notice(np, fmt, ...) \
66 pr_notice("%s: " fmt, np->name, ##__VA_ARGS__)
67
netpoll_start_xmit(struct sk_buff * skb,struct net_device * dev,struct netdev_queue * txq)68 static netdev_tx_t netpoll_start_xmit(struct sk_buff *skb,
69 struct net_device *dev,
70 struct netdev_queue *txq)
71 {
72 netdev_tx_t status = NETDEV_TX_OK;
73 netdev_features_t features;
74
75 features = netif_skb_features(skb);
76
77 if (skb_vlan_tag_present(skb) &&
78 !vlan_hw_offload_capable(features, skb->vlan_proto)) {
79 skb = __vlan_hwaccel_push_inside(skb);
80 if (unlikely(!skb)) {
81 /* This is actually a packet drop, but we
82 * don't want the code that calls this
83 * function to try and operate on a NULL skb.
84 */
85 goto out;
86 }
87 }
88
89 status = netdev_start_xmit(skb, dev, txq, false);
90
91 out:
92 return status;
93 }
94
queue_process(struct work_struct * work)95 static void queue_process(struct work_struct *work)
96 {
97 struct netpoll_info *npinfo =
98 container_of(work, struct netpoll_info, tx_work.work);
99 struct sk_buff *skb;
100 unsigned long flags;
101
102 while ((skb = skb_dequeue(&npinfo->txq))) {
103 struct net_device *dev = skb->dev;
104 struct netdev_queue *txq;
105 unsigned int q_index;
106
107 if (!netif_device_present(dev) || !netif_running(dev)) {
108 kfree_skb(skb);
109 continue;
110 }
111
112 local_irq_save(flags);
113 /* check if skb->queue_mapping is still valid */
114 q_index = skb_get_queue_mapping(skb);
115 if (unlikely(q_index >= dev->real_num_tx_queues)) {
116 q_index = q_index % dev->real_num_tx_queues;
117 skb_set_queue_mapping(skb, q_index);
118 }
119 txq = netdev_get_tx_queue(dev, q_index);
120 HARD_TX_LOCK(dev, txq, smp_processor_id());
121 if (netif_xmit_frozen_or_stopped(txq) ||
122 !dev_xmit_complete(netpoll_start_xmit(skb, dev, txq))) {
123 skb_queue_head(&npinfo->txq, skb);
124 HARD_TX_UNLOCK(dev, txq);
125 local_irq_restore(flags);
126
127 schedule_delayed_work(&npinfo->tx_work, HZ/10);
128 return;
129 }
130 HARD_TX_UNLOCK(dev, txq);
131 local_irq_restore(flags);
132 }
133 }
134
netif_local_xmit_active(struct net_device * dev)135 static int netif_local_xmit_active(struct net_device *dev)
136 {
137 int i;
138
139 for (i = 0; i < dev->num_tx_queues; i++) {
140 struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
141
142 if (READ_ONCE(txq->xmit_lock_owner) == smp_processor_id())
143 return 1;
144 }
145
146 return 0;
147 }
148
poll_one_napi(struct napi_struct * napi)149 static void poll_one_napi(struct napi_struct *napi)
150 {
151 int work;
152
153 /* If we set this bit but see that it has already been set,
154 * that indicates that napi has been disabled and we need
155 * to abort this operation
156 */
157 if (test_and_set_bit(NAPI_STATE_NPSVC, &napi->state))
158 return;
159
160 /* We explicitly pass the polling call a budget of 0 to
161 * indicate that we are clearing the Tx path only.
162 */
163 work = napi->poll(napi, 0);
164 WARN_ONCE(work, "%pS exceeded budget in poll\n", napi->poll);
165 trace_napi_poll(napi, work, 0);
166
167 clear_bit(NAPI_STATE_NPSVC, &napi->state);
168 }
169
poll_napi(struct net_device * dev)170 static void poll_napi(struct net_device *dev)
171 {
172 struct napi_struct *napi;
173 int cpu = smp_processor_id();
174
175 list_for_each_entry_rcu(napi, &dev->napi_list, dev_list) {
176 if (cmpxchg(&napi->poll_owner, -1, cpu) == -1) {
177 poll_one_napi(napi);
178 smp_store_release(&napi->poll_owner, -1);
179 }
180 }
181 }
182
netpoll_poll_dev(struct net_device * dev)183 void netpoll_poll_dev(struct net_device *dev)
184 {
185 struct netpoll_info *ni = rcu_dereference_bh(dev->npinfo);
186 const struct net_device_ops *ops;
187
188 /* Don't do any rx activity if the dev_lock mutex is held
189 * the dev_open/close paths use this to block netpoll activity
190 * while changing device state
191 */
192 if (!ni || down_trylock(&ni->dev_lock))
193 return;
194
195 /* Some drivers will take the same locks in poll and xmit,
196 * we can't poll if local CPU is already in xmit.
197 */
198 if (!netif_running(dev) || netif_local_xmit_active(dev)) {
199 up(&ni->dev_lock);
200 return;
201 }
202
203 ops = dev->netdev_ops;
204 if (ops->ndo_poll_controller)
205 ops->ndo_poll_controller(dev);
206
207 poll_napi(dev);
208
209 up(&ni->dev_lock);
210
211 zap_completion_queue();
212 }
213 EXPORT_SYMBOL(netpoll_poll_dev);
214
netpoll_poll_disable(struct net_device * dev)215 void netpoll_poll_disable(struct net_device *dev)
216 {
217 struct netpoll_info *ni;
218
219 might_sleep();
220 ni = rtnl_dereference(dev->npinfo);
221 if (ni)
222 down(&ni->dev_lock);
223 }
224
netpoll_poll_enable(struct net_device * dev)225 void netpoll_poll_enable(struct net_device *dev)
226 {
227 struct netpoll_info *ni;
228
229 ni = rtnl_dereference(dev->npinfo);
230 if (ni)
231 up(&ni->dev_lock);
232 }
233
refill_skbs(struct netpoll * np)234 static void refill_skbs(struct netpoll *np)
235 {
236 struct sk_buff_head *skb_pool;
237 struct sk_buff *skb;
238 unsigned long flags;
239
240 skb_pool = &np->skb_pool;
241
242 spin_lock_irqsave(&skb_pool->lock, flags);
243 while (skb_pool->qlen < MAX_SKBS) {
244 skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC);
245 if (!skb)
246 break;
247
248 __skb_queue_tail(skb_pool, skb);
249 }
250 spin_unlock_irqrestore(&skb_pool->lock, flags);
251 }
252
zap_completion_queue(void)253 static void zap_completion_queue(void)
254 {
255 unsigned long flags;
256 struct softnet_data *sd = &get_cpu_var(softnet_data);
257
258 if (sd->completion_queue) {
259 struct sk_buff *clist;
260
261 local_irq_save(flags);
262 clist = sd->completion_queue;
263 sd->completion_queue = NULL;
264 local_irq_restore(flags);
265
266 while (clist != NULL) {
267 struct sk_buff *skb = clist;
268 clist = clist->next;
269 if (!skb_irq_freeable(skb)) {
270 refcount_set(&skb->users, 1);
271 dev_kfree_skb_any(skb); /* put this one back */
272 } else {
273 __kfree_skb(skb);
274 }
275 }
276 }
277
278 put_cpu_var(softnet_data);
279 }
280
find_skb(struct netpoll * np,int len,int reserve)281 static struct sk_buff *find_skb(struct netpoll *np, int len, int reserve)
282 {
283 int count = 0;
284 struct sk_buff *skb;
285
286 zap_completion_queue();
287 refill_skbs(np);
288 repeat:
289
290 skb = alloc_skb(len, GFP_ATOMIC);
291 if (!skb)
292 skb = skb_dequeue(&np->skb_pool);
293
294 if (!skb) {
295 if (++count < 10) {
296 netpoll_poll_dev(np->dev);
297 goto repeat;
298 }
299 return NULL;
300 }
301
302 refcount_set(&skb->users, 1);
303 skb_reserve(skb, reserve);
304 return skb;
305 }
306
netpoll_owner_active(struct net_device * dev)307 static int netpoll_owner_active(struct net_device *dev)
308 {
309 struct napi_struct *napi;
310
311 list_for_each_entry_rcu(napi, &dev->napi_list, dev_list) {
312 if (READ_ONCE(napi->poll_owner) == smp_processor_id())
313 return 1;
314 }
315 return 0;
316 }
317
318 /* call with IRQ disabled */
__netpoll_send_skb(struct netpoll * np,struct sk_buff * skb)319 static netdev_tx_t __netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
320 {
321 netdev_tx_t status = NETDEV_TX_BUSY;
322 struct net_device *dev;
323 unsigned long tries;
324 /* It is up to the caller to keep npinfo alive. */
325 struct netpoll_info *npinfo;
326
327 lockdep_assert_irqs_disabled();
328
329 dev = np->dev;
330 npinfo = rcu_dereference_bh(dev->npinfo);
331
332 if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) {
333 dev_kfree_skb_irq(skb);
334 return NET_XMIT_DROP;
335 }
336
337 /* don't get messages out of order, and no recursion */
338 if (skb_queue_len(&npinfo->txq) == 0 && !netpoll_owner_active(dev)) {
339 struct netdev_queue *txq;
340
341 txq = netdev_core_pick_tx(dev, skb, NULL);
342
343 /* try until next clock tick */
344 for (tries = jiffies_to_usecs(1)/USEC_PER_POLL;
345 tries > 0; --tries) {
346 if (HARD_TX_TRYLOCK(dev, txq)) {
347 if (!netif_xmit_stopped(txq))
348 status = netpoll_start_xmit(skb, dev, txq);
349
350 HARD_TX_UNLOCK(dev, txq);
351
352 if (dev_xmit_complete(status))
353 break;
354
355 }
356
357 /* tickle device maybe there is some cleanup */
358 netpoll_poll_dev(np->dev);
359
360 udelay(USEC_PER_POLL);
361 }
362
363 WARN_ONCE(!irqs_disabled(),
364 "netpoll_send_skb_on_dev(): %s enabled interrupts in poll (%pS)\n",
365 dev->name, dev->netdev_ops->ndo_start_xmit);
366
367 }
368
369 if (!dev_xmit_complete(status)) {
370 skb_queue_tail(&npinfo->txq, skb);
371 schedule_delayed_work(&npinfo->tx_work,0);
372 }
373 return NETDEV_TX_OK;
374 }
375
netpoll_send_skb(struct netpoll * np,struct sk_buff * skb)376 netdev_tx_t netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
377 {
378 unsigned long flags;
379 netdev_tx_t ret;
380
381 if (unlikely(!np)) {
382 dev_kfree_skb_irq(skb);
383 ret = NET_XMIT_DROP;
384 } else {
385 local_irq_save(flags);
386 ret = __netpoll_send_skb(np, skb);
387 local_irq_restore(flags);
388 }
389 return ret;
390 }
391 EXPORT_SYMBOL(netpoll_send_skb);
392
netpoll_send_udp(struct netpoll * np,const char * msg,int len)393 void netpoll_send_udp(struct netpoll *np, const char *msg, int len)
394 {
395 int total_len, ip_len, udp_len;
396 struct sk_buff *skb;
397 struct udphdr *udph;
398 struct iphdr *iph;
399 struct ethhdr *eth;
400 static atomic_t ip_ident;
401 struct ipv6hdr *ip6h;
402
403 if (!IS_ENABLED(CONFIG_PREEMPT_RT))
404 WARN_ON_ONCE(!irqs_disabled());
405
406 udp_len = len + sizeof(*udph);
407 if (np->ipv6)
408 ip_len = udp_len + sizeof(*ip6h);
409 else
410 ip_len = udp_len + sizeof(*iph);
411
412 total_len = ip_len + LL_RESERVED_SPACE(np->dev);
413
414 skb = find_skb(np, total_len + np->dev->needed_tailroom,
415 total_len - len);
416 if (!skb)
417 return;
418
419 skb_copy_to_linear_data(skb, msg, len);
420 skb_put(skb, len);
421
422 skb_push(skb, sizeof(*udph));
423 skb_reset_transport_header(skb);
424 udph = udp_hdr(skb);
425 udph->source = htons(np->local_port);
426 udph->dest = htons(np->remote_port);
427 udph->len = htons(udp_len);
428
429 if (np->ipv6) {
430 udph->check = 0;
431 udph->check = csum_ipv6_magic(&np->local_ip.in6,
432 &np->remote_ip.in6,
433 udp_len, IPPROTO_UDP,
434 csum_partial(udph, udp_len, 0));
435 if (udph->check == 0)
436 udph->check = CSUM_MANGLED_0;
437
438 skb_push(skb, sizeof(*ip6h));
439 skb_reset_network_header(skb);
440 ip6h = ipv6_hdr(skb);
441
442 /* ip6h->version = 6; ip6h->priority = 0; */
443 *(unsigned char *)ip6h = 0x60;
444 ip6h->flow_lbl[0] = 0;
445 ip6h->flow_lbl[1] = 0;
446 ip6h->flow_lbl[2] = 0;
447
448 ip6h->payload_len = htons(sizeof(struct udphdr) + len);
449 ip6h->nexthdr = IPPROTO_UDP;
450 ip6h->hop_limit = 32;
451 ip6h->saddr = np->local_ip.in6;
452 ip6h->daddr = np->remote_ip.in6;
453
454 eth = skb_push(skb, ETH_HLEN);
455 skb_reset_mac_header(skb);
456 skb->protocol = eth->h_proto = htons(ETH_P_IPV6);
457 } else {
458 udph->check = 0;
459 udph->check = csum_tcpudp_magic(np->local_ip.ip,
460 np->remote_ip.ip,
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(*iph));
467 skb_reset_network_header(skb);
468 iph = ip_hdr(skb);
469
470 /* iph->version = 4; iph->ihl = 5; */
471 *(unsigned char *)iph = 0x45;
472 iph->tos = 0;
473 put_unaligned(htons(ip_len), &(iph->tot_len));
474 iph->id = htons(atomic_inc_return(&ip_ident));
475 iph->frag_off = 0;
476 iph->ttl = 64;
477 iph->protocol = IPPROTO_UDP;
478 iph->check = 0;
479 put_unaligned(np->local_ip.ip, &(iph->saddr));
480 put_unaligned(np->remote_ip.ip, &(iph->daddr));
481 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl);
482
483 eth = skb_push(skb, ETH_HLEN);
484 skb_reset_mac_header(skb);
485 skb->protocol = eth->h_proto = htons(ETH_P_IP);
486 }
487
488 ether_addr_copy(eth->h_source, np->dev->dev_addr);
489 ether_addr_copy(eth->h_dest, np->remote_mac);
490
491 skb->dev = np->dev;
492
493 netpoll_send_skb(np, skb);
494 }
495 EXPORT_SYMBOL(netpoll_send_udp);
496
netpoll_print_options(struct netpoll * np)497 void netpoll_print_options(struct netpoll *np)
498 {
499 np_info(np, "local port %d\n", np->local_port);
500 if (np->ipv6)
501 np_info(np, "local IPv6 address %pI6c\n", &np->local_ip.in6);
502 else
503 np_info(np, "local IPv4 address %pI4\n", &np->local_ip.ip);
504 np_info(np, "interface '%s'\n", np->dev_name);
505 np_info(np, "remote port %d\n", np->remote_port);
506 if (np->ipv6)
507 np_info(np, "remote IPv6 address %pI6c\n", &np->remote_ip.in6);
508 else
509 np_info(np, "remote IPv4 address %pI4\n", &np->remote_ip.ip);
510 np_info(np, "remote ethernet address %pM\n", np->remote_mac);
511 }
512 EXPORT_SYMBOL(netpoll_print_options);
513
netpoll_parse_ip_addr(const char * str,union inet_addr * addr)514 static int netpoll_parse_ip_addr(const char *str, union inet_addr *addr)
515 {
516 const char *end;
517
518 if (!strchr(str, ':') &&
519 in4_pton(str, -1, (void *)addr, -1, &end) > 0) {
520 if (!*end)
521 return 0;
522 }
523 if (in6_pton(str, -1, addr->in6.s6_addr, -1, &end) > 0) {
524 #if IS_ENABLED(CONFIG_IPV6)
525 if (!*end)
526 return 1;
527 #else
528 return -1;
529 #endif
530 }
531 return -1;
532 }
533
skb_pool_flush(struct netpoll * np)534 static void skb_pool_flush(struct netpoll *np)
535 {
536 struct sk_buff_head *skb_pool;
537
538 skb_pool = &np->skb_pool;
539 skb_queue_purge_reason(skb_pool, SKB_CONSUMED);
540 }
541
netpoll_parse_options(struct netpoll * np,char * opt)542 int netpoll_parse_options(struct netpoll *np, char *opt)
543 {
544 char *cur=opt, *delim;
545 int ipv6;
546 bool ipversion_set = false;
547
548 if (*cur != '@') {
549 if ((delim = strchr(cur, '@')) == NULL)
550 goto parse_failed;
551 *delim = 0;
552 if (kstrtou16(cur, 10, &np->local_port))
553 goto parse_failed;
554 cur = delim;
555 }
556 cur++;
557
558 if (*cur != '/') {
559 ipversion_set = true;
560 if ((delim = strchr(cur, '/')) == NULL)
561 goto parse_failed;
562 *delim = 0;
563 ipv6 = netpoll_parse_ip_addr(cur, &np->local_ip);
564 if (ipv6 < 0)
565 goto parse_failed;
566 else
567 np->ipv6 = (bool)ipv6;
568 cur = delim;
569 }
570 cur++;
571
572 if (*cur != ',') {
573 /* parse out dev name */
574 if ((delim = strchr(cur, ',')) == NULL)
575 goto parse_failed;
576 *delim = 0;
577 strscpy(np->dev_name, cur, sizeof(np->dev_name));
578 cur = delim;
579 }
580 cur++;
581
582 if (*cur != '@') {
583 /* dst port */
584 if ((delim = strchr(cur, '@')) == NULL)
585 goto parse_failed;
586 *delim = 0;
587 if (*cur == ' ' || *cur == '\t')
588 np_info(np, "warning: whitespace is not allowed\n");
589 if (kstrtou16(cur, 10, &np->remote_port))
590 goto parse_failed;
591 cur = delim;
592 }
593 cur++;
594
595 /* dst ip */
596 if ((delim = strchr(cur, '/')) == NULL)
597 goto parse_failed;
598 *delim = 0;
599 ipv6 = netpoll_parse_ip_addr(cur, &np->remote_ip);
600 if (ipv6 < 0)
601 goto parse_failed;
602 else if (ipversion_set && np->ipv6 != (bool)ipv6)
603 goto parse_failed;
604 else
605 np->ipv6 = (bool)ipv6;
606 cur = delim + 1;
607
608 if (*cur != 0) {
609 /* MAC address */
610 if (!mac_pton(cur, np->remote_mac))
611 goto parse_failed;
612 }
613
614 netpoll_print_options(np);
615
616 return 0;
617
618 parse_failed:
619 np_info(np, "couldn't parse config at '%s'!\n", cur);
620 return -1;
621 }
622 EXPORT_SYMBOL(netpoll_parse_options);
623
__netpoll_setup(struct netpoll * np,struct net_device * ndev)624 int __netpoll_setup(struct netpoll *np, struct net_device *ndev)
625 {
626 struct netpoll_info *npinfo;
627 const struct net_device_ops *ops;
628 int err;
629
630 if (ndev->priv_flags & IFF_DISABLE_NETPOLL) {
631 np_err(np, "%s doesn't support polling, aborting\n",
632 ndev->name);
633 err = -ENOTSUPP;
634 goto out;
635 }
636
637 if (!rcu_access_pointer(ndev->npinfo)) {
638 npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL);
639 if (!npinfo) {
640 err = -ENOMEM;
641 goto out;
642 }
643
644 sema_init(&npinfo->dev_lock, 1);
645 skb_queue_head_init(&npinfo->txq);
646 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process);
647
648 refcount_set(&npinfo->refcnt, 1);
649
650 ops = ndev->netdev_ops;
651 if (ops->ndo_netpoll_setup) {
652 err = ops->ndo_netpoll_setup(ndev);
653 if (err)
654 goto free_npinfo;
655 }
656 } else {
657 npinfo = rtnl_dereference(ndev->npinfo);
658 refcount_inc(&npinfo->refcnt);
659 }
660
661 np->dev = ndev;
662 strscpy(np->dev_name, ndev->name, IFNAMSIZ);
663 npinfo->netpoll = np;
664
665 /* last thing to do is link it to the net device structure */
666 rcu_assign_pointer(ndev->npinfo, npinfo);
667
668 return 0;
669
670 free_npinfo:
671 kfree(npinfo);
672 out:
673 return err;
674 }
675 EXPORT_SYMBOL_GPL(__netpoll_setup);
676
netpoll_setup(struct netpoll * np)677 int netpoll_setup(struct netpoll *np)
678 {
679 struct net_device *ndev = NULL;
680 bool ip_overwritten = false;
681 struct in_device *in_dev;
682 int err;
683
684 skb_queue_head_init(&np->skb_pool);
685
686 rtnl_lock();
687 if (np->dev_name[0]) {
688 struct net *net = current->nsproxy->net_ns;
689 ndev = __dev_get_by_name(net, np->dev_name);
690 }
691 if (!ndev) {
692 np_err(np, "%s doesn't exist, aborting\n", np->dev_name);
693 err = -ENODEV;
694 goto unlock;
695 }
696 netdev_hold(ndev, &np->dev_tracker, GFP_KERNEL);
697
698 if (netdev_master_upper_dev_get(ndev)) {
699 np_err(np, "%s is a slave device, aborting\n", np->dev_name);
700 err = -EBUSY;
701 goto put;
702 }
703
704 if (!netif_running(ndev)) {
705 unsigned long atmost;
706
707 np_info(np, "device %s not up yet, forcing it\n", np->dev_name);
708
709 err = dev_open(ndev, NULL);
710
711 if (err) {
712 np_err(np, "failed to open %s\n", ndev->name);
713 goto put;
714 }
715
716 rtnl_unlock();
717 atmost = jiffies + carrier_timeout * HZ;
718 while (!netif_carrier_ok(ndev)) {
719 if (time_after(jiffies, atmost)) {
720 np_notice(np, "timeout waiting for carrier\n");
721 break;
722 }
723 msleep(1);
724 }
725
726 rtnl_lock();
727 }
728
729 if (!np->local_ip.ip) {
730 if (!np->ipv6) {
731 const struct in_ifaddr *ifa;
732
733 in_dev = __in_dev_get_rtnl(ndev);
734 if (!in_dev)
735 goto put_noaddr;
736
737 ifa = rtnl_dereference(in_dev->ifa_list);
738 if (!ifa) {
739 put_noaddr:
740 np_err(np, "no IP address for %s, aborting\n",
741 np->dev_name);
742 err = -EDESTADDRREQ;
743 goto put;
744 }
745
746 np->local_ip.ip = ifa->ifa_local;
747 ip_overwritten = true;
748 np_info(np, "local IP %pI4\n", &np->local_ip.ip);
749 } else {
750 #if IS_ENABLED(CONFIG_IPV6)
751 struct inet6_dev *idev;
752
753 err = -EDESTADDRREQ;
754 idev = __in6_dev_get(ndev);
755 if (idev) {
756 struct inet6_ifaddr *ifp;
757
758 read_lock_bh(&idev->lock);
759 list_for_each_entry(ifp, &idev->addr_list, if_list) {
760 if (!!(ipv6_addr_type(&ifp->addr) & IPV6_ADDR_LINKLOCAL) !=
761 !!(ipv6_addr_type(&np->remote_ip.in6) & IPV6_ADDR_LINKLOCAL))
762 continue;
763 np->local_ip.in6 = ifp->addr;
764 ip_overwritten = true;
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(np);
787
788 err = __netpoll_setup(np, ndev);
789 if (err)
790 goto flush;
791 rtnl_unlock();
792 return 0;
793
794 flush:
795 skb_pool_flush(np);
796 put:
797 DEBUG_NET_WARN_ON_ONCE(np->dev);
798 if (ip_overwritten)
799 memset(&np->local_ip, 0, sizeof(np->local_ip));
800 netdev_put(ndev, &np->dev_tracker);
801 unlock:
802 rtnl_unlock();
803 return err;
804 }
805 EXPORT_SYMBOL(netpoll_setup);
806
rcu_cleanup_netpoll_info(struct rcu_head * rcu_head)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
__netpoll_cleanup(struct netpoll * np)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 if (refcount_dec_and_test(&npinfo->refcnt)) {
833 const struct net_device_ops *ops;
834
835 ops = np->dev->netdev_ops;
836 if (ops->ndo_netpoll_cleanup)
837 ops->ndo_netpoll_cleanup(np->dev);
838
839 RCU_INIT_POINTER(np->dev->npinfo, NULL);
840 call_rcu(&npinfo->rcu, rcu_cleanup_netpoll_info);
841 } else
842 RCU_INIT_POINTER(np->dev->npinfo, NULL);
843
844 skb_pool_flush(np);
845 }
846 EXPORT_SYMBOL_GPL(__netpoll_cleanup);
847
__netpoll_free(struct netpoll * np)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
do_netpoll_cleanup(struct netpoll * np)859 void do_netpoll_cleanup(struct netpoll *np)
860 {
861 __netpoll_cleanup(np);
862 netdev_put(np->dev, &np->dev_tracker);
863 np->dev = NULL;
864 }
865 EXPORT_SYMBOL(do_netpoll_cleanup);
866
netpoll_cleanup(struct netpoll * np)867 void netpoll_cleanup(struct netpoll *np)
868 {
869 rtnl_lock();
870 if (!np->dev)
871 goto out;
872 do_netpoll_cleanup(np);
873 out:
874 rtnl_unlock();
875 }
876 EXPORT_SYMBOL(netpoll_cleanup);
877