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
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
netif_local_xmit_active(struct net_device * dev)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
poll_one_napi(struct napi_struct * napi)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
poll_napi(struct net_device * dev)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
netpoll_poll_dev(struct net_device * dev)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
netpoll_poll_disable(struct net_device * dev)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 EXPORT_SYMBOL(netpoll_poll_disable);
232
netpoll_poll_enable(struct net_device * dev)233 void netpoll_poll_enable(struct net_device *dev)
234 {
235 struct netpoll_info *ni;
236 rcu_read_lock();
237 ni = rcu_dereference(dev->npinfo);
238 if (ni)
239 up(&ni->dev_lock);
240 rcu_read_unlock();
241 }
242 EXPORT_SYMBOL(netpoll_poll_enable);
243
refill_skbs(void)244 static void refill_skbs(void)
245 {
246 struct sk_buff *skb;
247 unsigned long flags;
248
249 spin_lock_irqsave(&skb_pool.lock, flags);
250 while (skb_pool.qlen < MAX_SKBS) {
251 skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC);
252 if (!skb)
253 break;
254
255 __skb_queue_tail(&skb_pool, skb);
256 }
257 spin_unlock_irqrestore(&skb_pool.lock, flags);
258 }
259
zap_completion_queue(void)260 static void zap_completion_queue(void)
261 {
262 unsigned long flags;
263 struct softnet_data *sd = &get_cpu_var(softnet_data);
264
265 if (sd->completion_queue) {
266 struct sk_buff *clist;
267
268 local_irq_save(flags);
269 clist = sd->completion_queue;
270 sd->completion_queue = NULL;
271 local_irq_restore(flags);
272
273 while (clist != NULL) {
274 struct sk_buff *skb = clist;
275 clist = clist->next;
276 if (!skb_irq_freeable(skb)) {
277 refcount_set(&skb->users, 1);
278 dev_kfree_skb_any(skb); /* put this one back */
279 } else {
280 __kfree_skb(skb);
281 }
282 }
283 }
284
285 put_cpu_var(softnet_data);
286 }
287
find_skb(struct netpoll * np,int len,int reserve)288 static struct sk_buff *find_skb(struct netpoll *np, int len, int reserve)
289 {
290 int count = 0;
291 struct sk_buff *skb;
292
293 zap_completion_queue();
294 refill_skbs();
295 repeat:
296
297 skb = alloc_skb(len, GFP_ATOMIC);
298 if (!skb)
299 skb = skb_dequeue(&skb_pool);
300
301 if (!skb) {
302 if (++count < 10) {
303 netpoll_poll_dev(np->dev);
304 goto repeat;
305 }
306 return NULL;
307 }
308
309 refcount_set(&skb->users, 1);
310 skb_reserve(skb, reserve);
311 return skb;
312 }
313
netpoll_owner_active(struct net_device * dev)314 static int netpoll_owner_active(struct net_device *dev)
315 {
316 struct napi_struct *napi;
317
318 list_for_each_entry_rcu(napi, &dev->napi_list, dev_list) {
319 if (READ_ONCE(napi->poll_owner) == smp_processor_id())
320 return 1;
321 }
322 return 0;
323 }
324
325 /* call with IRQ disabled */
__netpoll_send_skb(struct netpoll * np,struct sk_buff * skb)326 static netdev_tx_t __netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
327 {
328 netdev_tx_t status = NETDEV_TX_BUSY;
329 netdev_tx_t ret = NET_XMIT_DROP;
330 struct net_device *dev;
331 unsigned long tries;
332 /* It is up to the caller to keep npinfo alive. */
333 struct netpoll_info *npinfo;
334
335 lockdep_assert_irqs_disabled();
336
337 dev = np->dev;
338 rcu_read_lock();
339 npinfo = rcu_dereference_bh(dev->npinfo);
340
341 if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) {
342 dev_kfree_skb_irq(skb);
343 goto out;
344 }
345
346 /* don't get messages out of order, and no recursion */
347 if (skb_queue_len(&npinfo->txq) == 0 && !netpoll_owner_active(dev)) {
348 struct netdev_queue *txq;
349
350 txq = netdev_core_pick_tx(dev, skb, NULL);
351
352 /* try until next clock tick */
353 for (tries = jiffies_to_usecs(1)/USEC_PER_POLL;
354 tries > 0; --tries) {
355 if (HARD_TX_TRYLOCK(dev, txq)) {
356 if (!netif_xmit_stopped(txq))
357 status = netpoll_start_xmit(skb, dev, txq);
358
359 HARD_TX_UNLOCK(dev, txq);
360
361 if (dev_xmit_complete(status))
362 break;
363
364 }
365
366 /* tickle device maybe there is some cleanup */
367 netpoll_poll_dev(np->dev);
368
369 udelay(USEC_PER_POLL);
370 }
371
372 WARN_ONCE(!irqs_disabled(),
373 "netpoll_send_skb_on_dev(): %s enabled interrupts in poll (%pS)\n",
374 dev->name, dev->netdev_ops->ndo_start_xmit);
375
376 }
377
378 if (!dev_xmit_complete(status)) {
379 skb_queue_tail(&npinfo->txq, skb);
380 schedule_delayed_work(&npinfo->tx_work,0);
381 }
382 ret = NETDEV_TX_OK;
383 out:
384 rcu_read_unlock();
385 return ret;
386 }
387
netpoll_send_skb(struct netpoll * np,struct sk_buff * skb)388 netdev_tx_t netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
389 {
390 unsigned long flags;
391 netdev_tx_t ret;
392
393 if (unlikely(!np)) {
394 dev_kfree_skb_irq(skb);
395 ret = NET_XMIT_DROP;
396 } else {
397 local_irq_save(flags);
398 ret = __netpoll_send_skb(np, skb);
399 local_irq_restore(flags);
400 }
401 return ret;
402 }
403 EXPORT_SYMBOL(netpoll_send_skb);
404
netpoll_send_udp(struct netpoll * np,const char * msg,int len)405 void netpoll_send_udp(struct netpoll *np, const char *msg, int len)
406 {
407 int total_len, ip_len, udp_len;
408 struct sk_buff *skb;
409 struct udphdr *udph;
410 struct iphdr *iph;
411 struct ethhdr *eth;
412 static atomic_t ip_ident;
413 struct ipv6hdr *ip6h;
414
415 if (!IS_ENABLED(CONFIG_PREEMPT_RT))
416 WARN_ON_ONCE(!irqs_disabled());
417
418 udp_len = len + sizeof(*udph);
419 if (np->ipv6)
420 ip_len = udp_len + sizeof(*ip6h);
421 else
422 ip_len = udp_len + sizeof(*iph);
423
424 total_len = ip_len + LL_RESERVED_SPACE(np->dev);
425
426 skb = find_skb(np, total_len + np->dev->needed_tailroom,
427 total_len - len);
428 if (!skb)
429 return;
430
431 skb_copy_to_linear_data(skb, msg, len);
432 skb_put(skb, len);
433
434 skb_push(skb, sizeof(*udph));
435 skb_reset_transport_header(skb);
436 udph = udp_hdr(skb);
437 udph->source = htons(np->local_port);
438 udph->dest = htons(np->remote_port);
439 udph->len = htons(udp_len);
440
441 if (np->ipv6) {
442 udph->check = 0;
443 udph->check = csum_ipv6_magic(&np->local_ip.in6,
444 &np->remote_ip.in6,
445 udp_len, IPPROTO_UDP,
446 csum_partial(udph, udp_len, 0));
447 if (udph->check == 0)
448 udph->check = CSUM_MANGLED_0;
449
450 skb_push(skb, sizeof(*ip6h));
451 skb_reset_network_header(skb);
452 ip6h = ipv6_hdr(skb);
453
454 /* ip6h->version = 6; ip6h->priority = 0; */
455 *(unsigned char *)ip6h = 0x60;
456 ip6h->flow_lbl[0] = 0;
457 ip6h->flow_lbl[1] = 0;
458 ip6h->flow_lbl[2] = 0;
459
460 ip6h->payload_len = htons(sizeof(struct udphdr) + len);
461 ip6h->nexthdr = IPPROTO_UDP;
462 ip6h->hop_limit = 32;
463 ip6h->saddr = np->local_ip.in6;
464 ip6h->daddr = np->remote_ip.in6;
465
466 eth = skb_push(skb, ETH_HLEN);
467 skb_reset_mac_header(skb);
468 skb->protocol = eth->h_proto = htons(ETH_P_IPV6);
469 } else {
470 udph->check = 0;
471 udph->check = csum_tcpudp_magic(np->local_ip.ip,
472 np->remote_ip.ip,
473 udp_len, IPPROTO_UDP,
474 csum_partial(udph, udp_len, 0));
475 if (udph->check == 0)
476 udph->check = CSUM_MANGLED_0;
477
478 skb_push(skb, sizeof(*iph));
479 skb_reset_network_header(skb);
480 iph = ip_hdr(skb);
481
482 /* iph->version = 4; iph->ihl = 5; */
483 *(unsigned char *)iph = 0x45;
484 iph->tos = 0;
485 put_unaligned(htons(ip_len), &(iph->tot_len));
486 iph->id = htons(atomic_inc_return(&ip_ident));
487 iph->frag_off = 0;
488 iph->ttl = 64;
489 iph->protocol = IPPROTO_UDP;
490 iph->check = 0;
491 put_unaligned(np->local_ip.ip, &(iph->saddr));
492 put_unaligned(np->remote_ip.ip, &(iph->daddr));
493 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl);
494
495 eth = skb_push(skb, ETH_HLEN);
496 skb_reset_mac_header(skb);
497 skb->protocol = eth->h_proto = htons(ETH_P_IP);
498 }
499
500 ether_addr_copy(eth->h_source, np->dev->dev_addr);
501 ether_addr_copy(eth->h_dest, np->remote_mac);
502
503 skb->dev = np->dev;
504
505 netpoll_send_skb(np, skb);
506 }
507 EXPORT_SYMBOL(netpoll_send_udp);
508
netpoll_print_options(struct netpoll * np)509 void netpoll_print_options(struct netpoll *np)
510 {
511 np_info(np, "local port %d\n", np->local_port);
512 if (np->ipv6)
513 np_info(np, "local IPv6 address %pI6c\n", &np->local_ip.in6);
514 else
515 np_info(np, "local IPv4 address %pI4\n", &np->local_ip.ip);
516 np_info(np, "interface '%s'\n", np->dev_name);
517 np_info(np, "remote port %d\n", np->remote_port);
518 if (np->ipv6)
519 np_info(np, "remote IPv6 address %pI6c\n", &np->remote_ip.in6);
520 else
521 np_info(np, "remote IPv4 address %pI4\n", &np->remote_ip.ip);
522 np_info(np, "remote ethernet address %pM\n", np->remote_mac);
523 }
524 EXPORT_SYMBOL(netpoll_print_options);
525
netpoll_parse_ip_addr(const char * str,union inet_addr * addr)526 static int netpoll_parse_ip_addr(const char *str, union inet_addr *addr)
527 {
528 const char *end;
529
530 if (!strchr(str, ':') &&
531 in4_pton(str, -1, (void *)addr, -1, &end) > 0) {
532 if (!*end)
533 return 0;
534 }
535 if (in6_pton(str, -1, addr->in6.s6_addr, -1, &end) > 0) {
536 #if IS_ENABLED(CONFIG_IPV6)
537 if (!*end)
538 return 1;
539 #else
540 return -1;
541 #endif
542 }
543 return -1;
544 }
545
netpoll_parse_options(struct netpoll * np,char * opt)546 int netpoll_parse_options(struct netpoll *np, char *opt)
547 {
548 char *cur=opt, *delim;
549 int ipv6;
550 bool ipversion_set = false;
551
552 if (*cur != '@') {
553 if ((delim = strchr(cur, '@')) == NULL)
554 goto parse_failed;
555 *delim = 0;
556 if (kstrtou16(cur, 10, &np->local_port))
557 goto parse_failed;
558 cur = delim;
559 }
560 cur++;
561
562 if (*cur != '/') {
563 ipversion_set = true;
564 if ((delim = strchr(cur, '/')) == NULL)
565 goto parse_failed;
566 *delim = 0;
567 ipv6 = netpoll_parse_ip_addr(cur, &np->local_ip);
568 if (ipv6 < 0)
569 goto parse_failed;
570 else
571 np->ipv6 = (bool)ipv6;
572 cur = delim;
573 }
574 cur++;
575
576 if (*cur != ',') {
577 /* parse out dev name */
578 if ((delim = strchr(cur, ',')) == NULL)
579 goto parse_failed;
580 *delim = 0;
581 strscpy(np->dev_name, cur, sizeof(np->dev_name));
582 cur = delim;
583 }
584 cur++;
585
586 if (*cur != '@') {
587 /* dst port */
588 if ((delim = strchr(cur, '@')) == NULL)
589 goto parse_failed;
590 *delim = 0;
591 if (*cur == ' ' || *cur == '\t')
592 np_info(np, "warning: whitespace is not allowed\n");
593 if (kstrtou16(cur, 10, &np->remote_port))
594 goto parse_failed;
595 cur = delim;
596 }
597 cur++;
598
599 /* dst ip */
600 if ((delim = strchr(cur, '/')) == NULL)
601 goto parse_failed;
602 *delim = 0;
603 ipv6 = netpoll_parse_ip_addr(cur, &np->remote_ip);
604 if (ipv6 < 0)
605 goto parse_failed;
606 else if (ipversion_set && np->ipv6 != (bool)ipv6)
607 goto parse_failed;
608 else
609 np->ipv6 = (bool)ipv6;
610 cur = delim + 1;
611
612 if (*cur != 0) {
613 /* MAC address */
614 if (!mac_pton(cur, np->remote_mac))
615 goto parse_failed;
616 }
617
618 netpoll_print_options(np);
619
620 return 0;
621
622 parse_failed:
623 np_info(np, "couldn't parse config at '%s'!\n", cur);
624 return -1;
625 }
626 EXPORT_SYMBOL(netpoll_parse_options);
627
__netpoll_setup(struct netpoll * np,struct net_device * ndev)628 int __netpoll_setup(struct netpoll *np, struct net_device *ndev)
629 {
630 struct netpoll_info *npinfo;
631 const struct net_device_ops *ops;
632 int err;
633
634 if (ndev->priv_flags & IFF_DISABLE_NETPOLL) {
635 np_err(np, "%s doesn't support polling, aborting\n",
636 ndev->name);
637 err = -ENOTSUPP;
638 goto out;
639 }
640
641 if (!rcu_access_pointer(ndev->npinfo)) {
642 npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL);
643 if (!npinfo) {
644 err = -ENOMEM;
645 goto out;
646 }
647
648 sema_init(&npinfo->dev_lock, 1);
649 skb_queue_head_init(&npinfo->txq);
650 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process);
651
652 refcount_set(&npinfo->refcnt, 1);
653
654 ops = ndev->netdev_ops;
655 if (ops->ndo_netpoll_setup) {
656 err = ops->ndo_netpoll_setup(ndev, npinfo);
657 if (err)
658 goto free_npinfo;
659 }
660 } else {
661 npinfo = rtnl_dereference(ndev->npinfo);
662 refcount_inc(&npinfo->refcnt);
663 }
664
665 np->dev = ndev;
666 strscpy(np->dev_name, ndev->name, IFNAMSIZ);
667 npinfo->netpoll = np;
668
669 /* last thing to do is link it to the net device structure */
670 rcu_assign_pointer(ndev->npinfo, npinfo);
671
672 return 0;
673
674 free_npinfo:
675 kfree(npinfo);
676 out:
677 return err;
678 }
679 EXPORT_SYMBOL_GPL(__netpoll_setup);
680
netpoll_setup(struct netpoll * np)681 int netpoll_setup(struct netpoll *np)
682 {
683 struct net_device *ndev = NULL;
684 bool ip_overwritten = false;
685 struct in_device *in_dev;
686 int err;
687
688 rtnl_lock();
689 if (np->dev_name[0]) {
690 struct net *net = current->nsproxy->net_ns;
691 ndev = __dev_get_by_name(net, np->dev_name);
692 }
693 if (!ndev) {
694 np_err(np, "%s doesn't exist, aborting\n", np->dev_name);
695 err = -ENODEV;
696 goto unlock;
697 }
698 netdev_hold(ndev, &np->dev_tracker, GFP_KERNEL);
699
700 if (netdev_master_upper_dev_get(ndev)) {
701 np_err(np, "%s is a slave device, aborting\n", np->dev_name);
702 err = -EBUSY;
703 goto put;
704 }
705
706 if (!netif_running(ndev)) {
707 unsigned long atmost;
708
709 np_info(np, "device %s not up yet, forcing it\n", np->dev_name);
710
711 err = dev_open(ndev, NULL);
712
713 if (err) {
714 np_err(np, "failed to open %s\n", ndev->name);
715 goto put;
716 }
717
718 rtnl_unlock();
719 atmost = jiffies + carrier_timeout * HZ;
720 while (!netif_carrier_ok(ndev)) {
721 if (time_after(jiffies, atmost)) {
722 np_notice(np, "timeout waiting for carrier\n");
723 break;
724 }
725 msleep(1);
726 }
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 ip_overwritten = true;
750 np_info(np, "local IP %pI4\n", &np->local_ip.ip);
751 } else {
752 #if IS_ENABLED(CONFIG_IPV6)
753 struct inet6_dev *idev;
754
755 err = -EDESTADDRREQ;
756 idev = __in6_dev_get(ndev);
757 if (idev) {
758 struct inet6_ifaddr *ifp;
759
760 read_lock_bh(&idev->lock);
761 list_for_each_entry(ifp, &idev->addr_list, if_list) {
762 if (!!(ipv6_addr_type(&ifp->addr) & IPV6_ADDR_LINKLOCAL) !=
763 !!(ipv6_addr_type(&np->remote_ip.in6) & IPV6_ADDR_LINKLOCAL))
764 continue;
765 np->local_ip.in6 = ifp->addr;
766 ip_overwritten = true;
767 err = 0;
768 break;
769 }
770 read_unlock_bh(&idev->lock);
771 }
772 if (err) {
773 np_err(np, "no IPv6 address for %s, aborting\n",
774 np->dev_name);
775 goto put;
776 } else
777 np_info(np, "local IPv6 %pI6c\n", &np->local_ip.in6);
778 #else
779 np_err(np, "IPv6 is not supported %s, aborting\n",
780 np->dev_name);
781 err = -EINVAL;
782 goto put;
783 #endif
784 }
785 }
786
787 /* fill up the skb queue */
788 refill_skbs();
789
790 err = __netpoll_setup(np, ndev);
791 if (err)
792 goto put;
793 rtnl_unlock();
794 return 0;
795
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
netpoll_init(void)807 static int __init netpoll_init(void)
808 {
809 skb_queue_head_init(&skb_pool);
810 return 0;
811 }
812 core_initcall(netpoll_init);
813
rcu_cleanup_netpoll_info(struct rcu_head * rcu_head)814 static void rcu_cleanup_netpoll_info(struct rcu_head *rcu_head)
815 {
816 struct netpoll_info *npinfo =
817 container_of(rcu_head, struct netpoll_info, rcu);
818
819 skb_queue_purge(&npinfo->txq);
820
821 /* we can't call cancel_delayed_work_sync here, as we are in softirq */
822 cancel_delayed_work(&npinfo->tx_work);
823
824 /* clean after last, unfinished work */
825 __skb_queue_purge(&npinfo->txq);
826 /* now cancel it again */
827 cancel_delayed_work(&npinfo->tx_work);
828 kfree(npinfo);
829 }
830
__netpoll_cleanup(struct netpoll * np)831 void __netpoll_cleanup(struct netpoll *np)
832 {
833 struct netpoll_info *npinfo;
834
835 npinfo = rtnl_dereference(np->dev->npinfo);
836 if (!npinfo)
837 return;
838
839 synchronize_srcu(&netpoll_srcu);
840
841 if (refcount_dec_and_test(&npinfo->refcnt)) {
842 const struct net_device_ops *ops;
843
844 ops = np->dev->netdev_ops;
845 if (ops->ndo_netpoll_cleanup)
846 ops->ndo_netpoll_cleanup(np->dev);
847
848 RCU_INIT_POINTER(np->dev->npinfo, NULL);
849 call_rcu(&npinfo->rcu, rcu_cleanup_netpoll_info);
850 } else
851 RCU_INIT_POINTER(np->dev->npinfo, NULL);
852 }
853 EXPORT_SYMBOL_GPL(__netpoll_cleanup);
854
__netpoll_free(struct netpoll * np)855 void __netpoll_free(struct netpoll *np)
856 {
857 ASSERT_RTNL();
858
859 /* Wait for transmitting packets to finish before freeing. */
860 synchronize_rcu();
861 __netpoll_cleanup(np);
862 kfree(np);
863 }
864 EXPORT_SYMBOL_GPL(__netpoll_free);
865
netpoll_cleanup(struct netpoll * np)866 void netpoll_cleanup(struct netpoll *np)
867 {
868 rtnl_lock();
869 if (!np->dev)
870 goto out;
871 __netpoll_cleanup(np);
872 netdev_put(np->dev, &np->dev_tracker);
873 np->dev = NULL;
874 out:
875 rtnl_unlock();
876 }
877 EXPORT_SYMBOL(netpoll_cleanup);
878