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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
49static struct sk_buff_head skb_pool;
50
51DEFINE_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
61static void zap_completion_queue(void);
62
63static unsigned int carrier_timeout = 4;
64module_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
73static 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
96out:
97 return status;
98}
99
100static 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
140static 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
154static 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
175static 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
188void 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}
218EXPORT_SYMBOL(netpoll_poll_dev);
219
220void 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}
231EXPORT_SYMBOL(netpoll_poll_disable);
232
233void 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}
242EXPORT_SYMBOL(netpoll_poll_enable);
243
244static 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
260static 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
288static 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();
295repeat:
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
314static 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 (napi->poll_owner == smp_processor_id())
320 return 1;
321 }
322 return 0;
323}
324
325/* call with IRQ disabled */
326static netdev_tx_t __netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
327{
328 netdev_tx_t status = NETDEV_TX_BUSY;
329 struct net_device *dev;
330 unsigned long tries;
331 /* It is up to the caller to keep npinfo alive. */
332 struct netpoll_info *npinfo;
333
334 lockdep_assert_irqs_disabled();
335
336 dev = np->dev;
337 npinfo = rcu_dereference_bh(dev->npinfo);
338
339 if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) {
340 dev_kfree_skb_irq(skb);
341 return NET_XMIT_DROP;
342 }
343
344 /* don't get messages out of order, and no recursion */
345 if (skb_queue_len(&npinfo->txq) == 0 && !netpoll_owner_active(dev)) {
346 struct netdev_queue *txq;
347
348 txq = netdev_core_pick_tx(dev, skb, NULL);
349
350 /* try until next clock tick */
351 for (tries = jiffies_to_usecs(1)/USEC_PER_POLL;
352 tries > 0; --tries) {
353 if (HARD_TX_TRYLOCK(dev, txq)) {
354 if (!netif_xmit_stopped(txq))
355 status = netpoll_start_xmit(skb, dev, txq);
356
357 HARD_TX_UNLOCK(dev, txq);
358
359 if (dev_xmit_complete(status))
360 break;
361
362 }
363
364 /* tickle device maybe there is some cleanup */
365 netpoll_poll_dev(np->dev);
366
367 udelay(USEC_PER_POLL);
368 }
369
370 WARN_ONCE(!irqs_disabled(),
371 "netpoll_send_skb_on_dev(): %s enabled interrupts in poll (%pS)\n",
372 dev->name, dev->netdev_ops->ndo_start_xmit);
373
374 }
375
376 if (!dev_xmit_complete(status)) {
377 skb_queue_tail(&npinfo->txq, skb);
378 schedule_delayed_work(&npinfo->tx_work,0);
379 }
380 return NETDEV_TX_OK;
381}
382
383netdev_tx_t netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
384{
385 unsigned long flags;
386 netdev_tx_t ret;
387
388 if (unlikely(!np)) {
389 dev_kfree_skb_irq(skb);
390 ret = NET_XMIT_DROP;
391 } else {
392 local_irq_save(flags);
393 ret = __netpoll_send_skb(np, skb);
394 local_irq_restore(flags);
395 }
396 return ret;
397}
398EXPORT_SYMBOL(netpoll_send_skb);
399
400void netpoll_send_udp(struct netpoll *np, const char *msg, int len)
401{
402 int total_len, ip_len, udp_len;
403 struct sk_buff *skb;
404 struct udphdr *udph;
405 struct iphdr *iph;
406 struct ethhdr *eth;
407 static atomic_t ip_ident;
408 struct ipv6hdr *ip6h;
409
410 if (!IS_ENABLED(CONFIG_PREEMPT_RT))
411 WARN_ON_ONCE(!irqs_disabled());
412
413 udp_len = len + sizeof(*udph);
414 if (np->ipv6)
415 ip_len = udp_len + sizeof(*ip6h);
416 else
417 ip_len = udp_len + sizeof(*iph);
418
419 total_len = ip_len + LL_RESERVED_SPACE(np->dev);
420
421 skb = find_skb(np, total_len + np->dev->needed_tailroom,
422 total_len - len);
423 if (!skb)
424 return;
425
426 skb_copy_to_linear_data(skb, msg, len);
427 skb_put(skb, len);
428
429 skb_push(skb, sizeof(*udph));
430 skb_reset_transport_header(skb);
431 udph = udp_hdr(skb);
432 udph->source = htons(np->local_port);
433 udph->dest = htons(np->remote_port);
434 udph->len = htons(udp_len);
435
436 if (np->ipv6) {
437 udph->check = 0;
438 udph->check = csum_ipv6_magic(&np->local_ip.in6,
439 &np->remote_ip.in6,
440 udp_len, IPPROTO_UDP,
441 csum_partial(udph, udp_len, 0));
442 if (udph->check == 0)
443 udph->check = CSUM_MANGLED_0;
444
445 skb_push(skb, sizeof(*ip6h));
446 skb_reset_network_header(skb);
447 ip6h = ipv6_hdr(skb);
448
449 /* ip6h->version = 6; ip6h->priority = 0; */
450 *(unsigned char *)ip6h = 0x60;
451 ip6h->flow_lbl[0] = 0;
452 ip6h->flow_lbl[1] = 0;
453 ip6h->flow_lbl[2] = 0;
454
455 ip6h->payload_len = htons(sizeof(struct udphdr) + len);
456 ip6h->nexthdr = IPPROTO_UDP;
457 ip6h->hop_limit = 32;
458 ip6h->saddr = np->local_ip.in6;
459 ip6h->daddr = np->remote_ip.in6;
460
461 eth = skb_push(skb, ETH_HLEN);
462 skb_reset_mac_header(skb);
463 skb->protocol = eth->h_proto = htons(ETH_P_IPV6);
464 } else {
465 udph->check = 0;
466 udph->check = csum_tcpudp_magic(np->local_ip.ip,
467 np->remote_ip.ip,
468 udp_len, IPPROTO_UDP,
469 csum_partial(udph, udp_len, 0));
470 if (udph->check == 0)
471 udph->check = CSUM_MANGLED_0;
472
473 skb_push(skb, sizeof(*iph));
474 skb_reset_network_header(skb);
475 iph = ip_hdr(skb);
476
477 /* iph->version = 4; iph->ihl = 5; */
478 *(unsigned char *)iph = 0x45;
479 iph->tos = 0;
480 put_unaligned(htons(ip_len), &(iph->tot_len));
481 iph->id = htons(atomic_inc_return(&ip_ident));
482 iph->frag_off = 0;
483 iph->ttl = 64;
484 iph->protocol = IPPROTO_UDP;
485 iph->check = 0;
486 put_unaligned(np->local_ip.ip, &(iph->saddr));
487 put_unaligned(np->remote_ip.ip, &(iph->daddr));
488 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl);
489
490 eth = skb_push(skb, ETH_HLEN);
491 skb_reset_mac_header(skb);
492 skb->protocol = eth->h_proto = htons(ETH_P_IP);
493 }
494
495 ether_addr_copy(eth->h_source, np->dev->dev_addr);
496 ether_addr_copy(eth->h_dest, np->remote_mac);
497
498 skb->dev = np->dev;
499
500 netpoll_send_skb(np, skb);
501}
502EXPORT_SYMBOL(netpoll_send_udp);
503
504void netpoll_print_options(struct netpoll *np)
505{
506 np_info(np, "local port %d\n", np->local_port);
507 if (np->ipv6)
508 np_info(np, "local IPv6 address %pI6c\n", &np->local_ip.in6);
509 else
510 np_info(np, "local IPv4 address %pI4\n", &np->local_ip.ip);
511 np_info(np, "interface '%s'\n", np->dev_name);
512 np_info(np, "remote port %d\n", np->remote_port);
513 if (np->ipv6)
514 np_info(np, "remote IPv6 address %pI6c\n", &np->remote_ip.in6);
515 else
516 np_info(np, "remote IPv4 address %pI4\n", &np->remote_ip.ip);
517 np_info(np, "remote ethernet address %pM\n", np->remote_mac);
518}
519EXPORT_SYMBOL(netpoll_print_options);
520
521static int netpoll_parse_ip_addr(const char *str, union inet_addr *addr)
522{
523 const char *end;
524
525 if (!strchr(str, ':') &&
526 in4_pton(str, -1, (void *)addr, -1, &end) > 0) {
527 if (!*end)
528 return 0;
529 }
530 if (in6_pton(str, -1, addr->in6.s6_addr, -1, &end) > 0) {
531#if IS_ENABLED(CONFIG_IPV6)
532 if (!*end)
533 return 1;
534#else
535 return -1;
536#endif
537 }
538 return -1;
539}
540
541int netpoll_parse_options(struct netpoll *np, char *opt)
542{
543 char *cur=opt, *delim;
544 int ipv6;
545 bool ipversion_set = false;
546
547 if (*cur != '@') {
548 if ((delim = strchr(cur, '@')) == NULL)
549 goto parse_failed;
550 *delim = 0;
551 if (kstrtou16(cur, 10, &np->local_port))
552 goto parse_failed;
553 cur = delim;
554 }
555 cur++;
556
557 if (*cur != '/') {
558 ipversion_set = true;
559 if ((delim = strchr(cur, '/')) == NULL)
560 goto parse_failed;
561 *delim = 0;
562 ipv6 = netpoll_parse_ip_addr(cur, &np->local_ip);
563 if (ipv6 < 0)
564 goto parse_failed;
565 else
566 np->ipv6 = (bool)ipv6;
567 cur = delim;
568 }
569 cur++;
570
571 if (*cur != ',') {
572 /* parse out dev name */
573 if ((delim = strchr(cur, ',')) == NULL)
574 goto parse_failed;
575 *delim = 0;
576 strscpy(np->dev_name, cur, sizeof(np->dev_name));
577 cur = delim;
578 }
579 cur++;
580
581 if (*cur != '@') {
582 /* dst port */
583 if ((delim = strchr(cur, '@')) == NULL)
584 goto parse_failed;
585 *delim = 0;
586 if (*cur == ' ' || *cur == '\t')
587 np_info(np, "warning: whitespace is not allowed\n");
588 if (kstrtou16(cur, 10, &np->remote_port))
589 goto parse_failed;
590 cur = delim;
591 }
592 cur++;
593
594 /* dst ip */
595 if ((delim = strchr(cur, '/')) == NULL)
596 goto parse_failed;
597 *delim = 0;
598 ipv6 = netpoll_parse_ip_addr(cur, &np->remote_ip);
599 if (ipv6 < 0)
600 goto parse_failed;
601 else if (ipversion_set && np->ipv6 != (bool)ipv6)
602 goto parse_failed;
603 else
604 np->ipv6 = (bool)ipv6;
605 cur = delim + 1;
606
607 if (*cur != 0) {
608 /* MAC address */
609 if (!mac_pton(cur, np->remote_mac))
610 goto parse_failed;
611 }
612
613 netpoll_print_options(np);
614
615 return 0;
616
617 parse_failed:
618 np_info(np, "couldn't parse config at '%s'!\n", cur);
619 return -1;
620}
621EXPORT_SYMBOL(netpoll_parse_options);
622
623int __netpoll_setup(struct netpoll *np, struct net_device *ndev)
624{
625 struct netpoll_info *npinfo;
626 const struct net_device_ops *ops;
627 int err;
628
629 np->dev = ndev;
630 strscpy(np->dev_name, ndev->name, IFNAMSIZ);
631
632 if (ndev->priv_flags & IFF_DISABLE_NETPOLL) {
633 np_err(np, "%s doesn't support polling, aborting\n",
634 np->dev_name);
635 err = -ENOTSUPP;
636 goto out;
637 }
638
639 if (!ndev->npinfo) {
640 npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL);
641 if (!npinfo) {
642 err = -ENOMEM;
643 goto out;
644 }
645
646 sema_init(&npinfo->dev_lock, 1);
647 skb_queue_head_init(&npinfo->txq);
648 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process);
649
650 refcount_set(&npinfo->refcnt, 1);
651
652 ops = np->dev->netdev_ops;
653 if (ops->ndo_netpoll_setup) {
654 err = ops->ndo_netpoll_setup(ndev, npinfo);
655 if (err)
656 goto free_npinfo;
657 }
658 } else {
659 npinfo = rtnl_dereference(ndev->npinfo);
660 refcount_inc(&npinfo->refcnt);
661 }
662
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
670free_npinfo:
671 kfree(npinfo);
672out:
673 return err;
674}
675EXPORT_SYMBOL_GPL(__netpoll_setup);
676
677int netpoll_setup(struct netpoll *np)
678{
679 struct net_device *ndev = NULL;
680 struct in_device *in_dev;
681 int err;
682
683 rtnl_lock();
684 if (np->dev_name[0]) {
685 struct net *net = current->nsproxy->net_ns;
686 ndev = __dev_get_by_name(net, np->dev_name);
687 }
688 if (!ndev) {
689 np_err(np, "%s doesn't exist, aborting\n", np->dev_name);
690 err = -ENODEV;
691 goto unlock;
692 }
693 netdev_hold(ndev, &np->dev_tracker, GFP_KERNEL);
694
695 if (netdev_master_upper_dev_get(ndev)) {
696 np_err(np, "%s is a slave device, aborting\n", np->dev_name);
697 err = -EBUSY;
698 goto put;
699 }
700
701 if (!netif_running(ndev)) {
702 unsigned long atmost;
703
704 np_info(np, "device %s not up yet, forcing it\n", np->dev_name);
705
706 err = dev_open(ndev, NULL);
707
708 if (err) {
709 np_err(np, "failed to open %s\n", ndev->name);
710 goto put;
711 }
712
713 rtnl_unlock();
714 atmost = jiffies + carrier_timeout * HZ;
715 while (!netif_carrier_ok(ndev)) {
716 if (time_after(jiffies, atmost)) {
717 np_notice(np, "timeout waiting for carrier\n");
718 break;
719 }
720 msleep(1);
721 }
722
723 rtnl_lock();
724 }
725
726 if (!np->local_ip.ip) {
727 if (!np->ipv6) {
728 const struct in_ifaddr *ifa;
729
730 in_dev = __in_dev_get_rtnl(ndev);
731 if (!in_dev)
732 goto put_noaddr;
733
734 ifa = rtnl_dereference(in_dev->ifa_list);
735 if (!ifa) {
736put_noaddr:
737 np_err(np, "no IP address for %s, aborting\n",
738 np->dev_name);
739 err = -EDESTADDRREQ;
740 goto put;
741 }
742
743 np->local_ip.ip = ifa->ifa_local;
744 np_info(np, "local IP %pI4\n", &np->local_ip.ip);
745 } else {
746#if IS_ENABLED(CONFIG_IPV6)
747 struct inet6_dev *idev;
748
749 err = -EDESTADDRREQ;
750 idev = __in6_dev_get(ndev);
751 if (idev) {
752 struct inet6_ifaddr *ifp;
753
754 read_lock_bh(&idev->lock);
755 list_for_each_entry(ifp, &idev->addr_list, if_list) {
756 if (!!(ipv6_addr_type(&ifp->addr) & IPV6_ADDR_LINKLOCAL) !=
757 !!(ipv6_addr_type(&np->remote_ip.in6) & IPV6_ADDR_LINKLOCAL))
758 continue;
759 np->local_ip.in6 = ifp->addr;
760 err = 0;
761 break;
762 }
763 read_unlock_bh(&idev->lock);
764 }
765 if (err) {
766 np_err(np, "no IPv6 address for %s, aborting\n",
767 np->dev_name);
768 goto put;
769 } else
770 np_info(np, "local IPv6 %pI6c\n", &np->local_ip.in6);
771#else
772 np_err(np, "IPv6 is not supported %s, aborting\n",
773 np->dev_name);
774 err = -EINVAL;
775 goto put;
776#endif
777 }
778 }
779
780 /* fill up the skb queue */
781 refill_skbs();
782
783 err = __netpoll_setup(np, ndev);
784 if (err)
785 goto put;
786 rtnl_unlock();
787 return 0;
788
789put:
790 netdev_put(ndev, &np->dev_tracker);
791unlock:
792 rtnl_unlock();
793 return err;
794}
795EXPORT_SYMBOL(netpoll_setup);
796
797static int __init netpoll_init(void)
798{
799 skb_queue_head_init(&skb_pool);
800 return 0;
801}
802core_initcall(netpoll_init);
803
804static void rcu_cleanup_netpoll_info(struct rcu_head *rcu_head)
805{
806 struct netpoll_info *npinfo =
807 container_of(rcu_head, struct netpoll_info, rcu);
808
809 skb_queue_purge(&npinfo->txq);
810
811 /* we can't call cancel_delayed_work_sync here, as we are in softirq */
812 cancel_delayed_work(&npinfo->tx_work);
813
814 /* clean after last, unfinished work */
815 __skb_queue_purge(&npinfo->txq);
816 /* now cancel it again */
817 cancel_delayed_work(&npinfo->tx_work);
818 kfree(npinfo);
819}
820
821void __netpoll_cleanup(struct netpoll *np)
822{
823 struct netpoll_info *npinfo;
824
825 npinfo = rtnl_dereference(np->dev->npinfo);
826 if (!npinfo)
827 return;
828
829 synchronize_srcu(&netpoll_srcu);
830
831 if (refcount_dec_and_test(&npinfo->refcnt)) {
832 const struct net_device_ops *ops;
833
834 ops = np->dev->netdev_ops;
835 if (ops->ndo_netpoll_cleanup)
836 ops->ndo_netpoll_cleanup(np->dev);
837
838 RCU_INIT_POINTER(np->dev->npinfo, NULL);
839 call_rcu(&npinfo->rcu, rcu_cleanup_netpoll_info);
840 } else
841 RCU_INIT_POINTER(np->dev->npinfo, NULL);
842}
843EXPORT_SYMBOL_GPL(__netpoll_cleanup);
844
845void __netpoll_free(struct netpoll *np)
846{
847 ASSERT_RTNL();
848
849 /* Wait for transmitting packets to finish before freeing. */
850 synchronize_rcu();
851 __netpoll_cleanup(np);
852 kfree(np);
853}
854EXPORT_SYMBOL_GPL(__netpoll_free);
855
856void netpoll_cleanup(struct netpoll *np)
857{
858 rtnl_lock();
859 if (!np->dev)
860 goto out;
861 __netpoll_cleanup(np);
862 netdev_put(np->dev, &np->dev_tracker);
863 np->dev = NULL;
864out:
865 rtnl_unlock();
866}
867EXPORT_SYMBOL(netpoll_cleanup);
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
40/*
41 * We maintain a small pool of fully-sized skbs, to make sure the
42 * message gets out even in extreme OOM situations.
43 */
44
45#define MAX_UDP_CHUNK 1460
46#define MAX_SKBS 32
47
48static struct sk_buff_head skb_pool;
49
50DEFINE_STATIC_SRCU(netpoll_srcu);
51
52#define USEC_PER_POLL 50
53
54#define MAX_SKB_SIZE \
55 (sizeof(struct ethhdr) + \
56 sizeof(struct iphdr) + \
57 sizeof(struct udphdr) + \
58 MAX_UDP_CHUNK)
59
60static void zap_completion_queue(void);
61
62static unsigned int carrier_timeout = 4;
63module_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
72static netdev_tx_t netpoll_start_xmit(struct sk_buff *skb,
73 struct net_device *dev,
74 struct netdev_queue *txq)
75{
76 netdev_tx_t status = NETDEV_TX_OK;
77 netdev_features_t features;
78
79 features = netif_skb_features(skb);
80
81 if (skb_vlan_tag_present(skb) &&
82 !vlan_hw_offload_capable(features, skb->vlan_proto)) {
83 skb = __vlan_hwaccel_push_inside(skb);
84 if (unlikely(!skb)) {
85 /* This is actually a packet drop, but we
86 * don't want the code that calls this
87 * function to try and operate on a NULL skb.
88 */
89 goto out;
90 }
91 }
92
93 status = netdev_start_xmit(skb, dev, txq, false);
94
95out:
96 return status;
97}
98
99static void queue_process(struct work_struct *work)
100{
101 struct netpoll_info *npinfo =
102 container_of(work, struct netpoll_info, tx_work.work);
103 struct sk_buff *skb;
104 unsigned long flags;
105
106 while ((skb = skb_dequeue(&npinfo->txq))) {
107 struct net_device *dev = skb->dev;
108 struct netdev_queue *txq;
109 unsigned int q_index;
110
111 if (!netif_device_present(dev) || !netif_running(dev)) {
112 kfree_skb(skb);
113 continue;
114 }
115
116 local_irq_save(flags);
117 /* check if skb->queue_mapping is still valid */
118 q_index = skb_get_queue_mapping(skb);
119 if (unlikely(q_index >= dev->real_num_tx_queues)) {
120 q_index = q_index % dev->real_num_tx_queues;
121 skb_set_queue_mapping(skb, q_index);
122 }
123 txq = netdev_get_tx_queue(dev, q_index);
124 HARD_TX_LOCK(dev, txq, smp_processor_id());
125 if (netif_xmit_frozen_or_stopped(txq) ||
126 !dev_xmit_complete(netpoll_start_xmit(skb, dev, txq))) {
127 skb_queue_head(&npinfo->txq, skb);
128 HARD_TX_UNLOCK(dev, txq);
129 local_irq_restore(flags);
130
131 schedule_delayed_work(&npinfo->tx_work, HZ/10);
132 return;
133 }
134 HARD_TX_UNLOCK(dev, txq);
135 local_irq_restore(flags);
136 }
137}
138
139static void poll_one_napi(struct napi_struct *napi)
140{
141 int work;
142
143 /* If we set this bit but see that it has already been set,
144 * that indicates that napi has been disabled and we need
145 * to abort this operation
146 */
147 if (test_and_set_bit(NAPI_STATE_NPSVC, &napi->state))
148 return;
149
150 /* We explicilty pass the polling call a budget of 0 to
151 * indicate that we are clearing the Tx path only.
152 */
153 work = napi->poll(napi, 0);
154 WARN_ONCE(work, "%pS exceeded budget in poll\n", napi->poll);
155 trace_napi_poll(napi, work, 0);
156
157 clear_bit(NAPI_STATE_NPSVC, &napi->state);
158}
159
160static void poll_napi(struct net_device *dev)
161{
162 struct napi_struct *napi;
163 int cpu = smp_processor_id();
164
165 list_for_each_entry_rcu(napi, &dev->napi_list, dev_list) {
166 if (cmpxchg(&napi->poll_owner, -1, cpu) == -1) {
167 poll_one_napi(napi);
168 smp_store_release(&napi->poll_owner, -1);
169 }
170 }
171}
172
173void netpoll_poll_dev(struct net_device *dev)
174{
175 struct netpoll_info *ni = rcu_dereference_bh(dev->npinfo);
176 const struct net_device_ops *ops;
177
178 /* Don't do any rx activity if the dev_lock mutex is held
179 * the dev_open/close paths use this to block netpoll activity
180 * while changing device state
181 */
182 if (!ni || down_trylock(&ni->dev_lock))
183 return;
184
185 if (!netif_running(dev)) {
186 up(&ni->dev_lock);
187 return;
188 }
189
190 ops = dev->netdev_ops;
191 if (ops->ndo_poll_controller)
192 ops->ndo_poll_controller(dev);
193
194 poll_napi(dev);
195
196 up(&ni->dev_lock);
197
198 zap_completion_queue();
199}
200EXPORT_SYMBOL(netpoll_poll_dev);
201
202void netpoll_poll_disable(struct net_device *dev)
203{
204 struct netpoll_info *ni;
205 int idx;
206 might_sleep();
207 idx = srcu_read_lock(&netpoll_srcu);
208 ni = srcu_dereference(dev->npinfo, &netpoll_srcu);
209 if (ni)
210 down(&ni->dev_lock);
211 srcu_read_unlock(&netpoll_srcu, idx);
212}
213EXPORT_SYMBOL(netpoll_poll_disable);
214
215void netpoll_poll_enable(struct net_device *dev)
216{
217 struct netpoll_info *ni;
218 rcu_read_lock();
219 ni = rcu_dereference(dev->npinfo);
220 if (ni)
221 up(&ni->dev_lock);
222 rcu_read_unlock();
223}
224EXPORT_SYMBOL(netpoll_poll_enable);
225
226static void refill_skbs(void)
227{
228 struct sk_buff *skb;
229 unsigned long flags;
230
231 spin_lock_irqsave(&skb_pool.lock, flags);
232 while (skb_pool.qlen < MAX_SKBS) {
233 skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC);
234 if (!skb)
235 break;
236
237 __skb_queue_tail(&skb_pool, skb);
238 }
239 spin_unlock_irqrestore(&skb_pool.lock, flags);
240}
241
242static void zap_completion_queue(void)
243{
244 unsigned long flags;
245 struct softnet_data *sd = &get_cpu_var(softnet_data);
246
247 if (sd->completion_queue) {
248 struct sk_buff *clist;
249
250 local_irq_save(flags);
251 clist = sd->completion_queue;
252 sd->completion_queue = NULL;
253 local_irq_restore(flags);
254
255 while (clist != NULL) {
256 struct sk_buff *skb = clist;
257 clist = clist->next;
258 if (!skb_irq_freeable(skb)) {
259 refcount_set(&skb->users, 1);
260 dev_kfree_skb_any(skb); /* put this one back */
261 } else {
262 __kfree_skb(skb);
263 }
264 }
265 }
266
267 put_cpu_var(softnet_data);
268}
269
270static struct sk_buff *find_skb(struct netpoll *np, int len, int reserve)
271{
272 int count = 0;
273 struct sk_buff *skb;
274
275 zap_completion_queue();
276 refill_skbs();
277repeat:
278
279 skb = alloc_skb(len, GFP_ATOMIC);
280 if (!skb)
281 skb = skb_dequeue(&skb_pool);
282
283 if (!skb) {
284 if (++count < 10) {
285 netpoll_poll_dev(np->dev);
286 goto repeat;
287 }
288 return NULL;
289 }
290
291 refcount_set(&skb->users, 1);
292 skb_reserve(skb, reserve);
293 return skb;
294}
295
296static int netpoll_owner_active(struct net_device *dev)
297{
298 struct napi_struct *napi;
299
300 list_for_each_entry(napi, &dev->napi_list, dev_list) {
301 if (napi->poll_owner == smp_processor_id())
302 return 1;
303 }
304 return 0;
305}
306
307/* call with IRQ disabled */
308static netdev_tx_t __netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
309{
310 netdev_tx_t status = NETDEV_TX_BUSY;
311 struct net_device *dev;
312 unsigned long tries;
313 /* It is up to the caller to keep npinfo alive. */
314 struct netpoll_info *npinfo;
315
316 lockdep_assert_irqs_disabled();
317
318 dev = np->dev;
319 npinfo = rcu_dereference_bh(dev->npinfo);
320
321 if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) {
322 dev_kfree_skb_irq(skb);
323 return NET_XMIT_DROP;
324 }
325
326 /* don't get messages out of order, and no recursion */
327 if (skb_queue_len(&npinfo->txq) == 0 && !netpoll_owner_active(dev)) {
328 struct netdev_queue *txq;
329
330 txq = netdev_core_pick_tx(dev, skb, NULL);
331
332 /* try until next clock tick */
333 for (tries = jiffies_to_usecs(1)/USEC_PER_POLL;
334 tries > 0; --tries) {
335 if (HARD_TX_TRYLOCK(dev, txq)) {
336 if (!netif_xmit_stopped(txq))
337 status = netpoll_start_xmit(skb, dev, txq);
338
339 HARD_TX_UNLOCK(dev, txq);
340
341 if (dev_xmit_complete(status))
342 break;
343
344 }
345
346 /* tickle device maybe there is some cleanup */
347 netpoll_poll_dev(np->dev);
348
349 udelay(USEC_PER_POLL);
350 }
351
352 WARN_ONCE(!irqs_disabled(),
353 "netpoll_send_skb_on_dev(): %s enabled interrupts in poll (%pS)\n",
354 dev->name, dev->netdev_ops->ndo_start_xmit);
355
356 }
357
358 if (!dev_xmit_complete(status)) {
359 skb_queue_tail(&npinfo->txq, skb);
360 schedule_delayed_work(&npinfo->tx_work,0);
361 }
362 return NETDEV_TX_OK;
363}
364
365netdev_tx_t netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
366{
367 unsigned long flags;
368 netdev_tx_t ret;
369
370 if (unlikely(!np)) {
371 dev_kfree_skb_irq(skb);
372 ret = NET_XMIT_DROP;
373 } else {
374 local_irq_save(flags);
375 ret = __netpoll_send_skb(np, skb);
376 local_irq_restore(flags);
377 }
378 return ret;
379}
380EXPORT_SYMBOL(netpoll_send_skb);
381
382void netpoll_send_udp(struct netpoll *np, const char *msg, int len)
383{
384 int total_len, ip_len, udp_len;
385 struct sk_buff *skb;
386 struct udphdr *udph;
387 struct iphdr *iph;
388 struct ethhdr *eth;
389 static atomic_t ip_ident;
390 struct ipv6hdr *ip6h;
391
392 WARN_ON_ONCE(!irqs_disabled());
393
394 udp_len = len + sizeof(*udph);
395 if (np->ipv6)
396 ip_len = udp_len + sizeof(*ip6h);
397 else
398 ip_len = udp_len + sizeof(*iph);
399
400 total_len = ip_len + LL_RESERVED_SPACE(np->dev);
401
402 skb = find_skb(np, total_len + np->dev->needed_tailroom,
403 total_len - len);
404 if (!skb)
405 return;
406
407 skb_copy_to_linear_data(skb, msg, len);
408 skb_put(skb, len);
409
410 skb_push(skb, sizeof(*udph));
411 skb_reset_transport_header(skb);
412 udph = udp_hdr(skb);
413 udph->source = htons(np->local_port);
414 udph->dest = htons(np->remote_port);
415 udph->len = htons(udp_len);
416
417 if (np->ipv6) {
418 udph->check = 0;
419 udph->check = csum_ipv6_magic(&np->local_ip.in6,
420 &np->remote_ip.in6,
421 udp_len, IPPROTO_UDP,
422 csum_partial(udph, udp_len, 0));
423 if (udph->check == 0)
424 udph->check = CSUM_MANGLED_0;
425
426 skb_push(skb, sizeof(*ip6h));
427 skb_reset_network_header(skb);
428 ip6h = ipv6_hdr(skb);
429
430 /* ip6h->version = 6; ip6h->priority = 0; */
431 put_unaligned(0x60, (unsigned char *)ip6h);
432 ip6h->flow_lbl[0] = 0;
433 ip6h->flow_lbl[1] = 0;
434 ip6h->flow_lbl[2] = 0;
435
436 ip6h->payload_len = htons(sizeof(struct udphdr) + len);
437 ip6h->nexthdr = IPPROTO_UDP;
438 ip6h->hop_limit = 32;
439 ip6h->saddr = np->local_ip.in6;
440 ip6h->daddr = np->remote_ip.in6;
441
442 eth = skb_push(skb, ETH_HLEN);
443 skb_reset_mac_header(skb);
444 skb->protocol = eth->h_proto = htons(ETH_P_IPV6);
445 } else {
446 udph->check = 0;
447 udph->check = csum_tcpudp_magic(np->local_ip.ip,
448 np->remote_ip.ip,
449 udp_len, IPPROTO_UDP,
450 csum_partial(udph, udp_len, 0));
451 if (udph->check == 0)
452 udph->check = CSUM_MANGLED_0;
453
454 skb_push(skb, sizeof(*iph));
455 skb_reset_network_header(skb);
456 iph = ip_hdr(skb);
457
458 /* iph->version = 4; iph->ihl = 5; */
459 put_unaligned(0x45, (unsigned char *)iph);
460 iph->tos = 0;
461 put_unaligned(htons(ip_len), &(iph->tot_len));
462 iph->id = htons(atomic_inc_return(&ip_ident));
463 iph->frag_off = 0;
464 iph->ttl = 64;
465 iph->protocol = IPPROTO_UDP;
466 iph->check = 0;
467 put_unaligned(np->local_ip.ip, &(iph->saddr));
468 put_unaligned(np->remote_ip.ip, &(iph->daddr));
469 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl);
470
471 eth = skb_push(skb, ETH_HLEN);
472 skb_reset_mac_header(skb);
473 skb->protocol = eth->h_proto = htons(ETH_P_IP);
474 }
475
476 ether_addr_copy(eth->h_source, np->dev->dev_addr);
477 ether_addr_copy(eth->h_dest, np->remote_mac);
478
479 skb->dev = np->dev;
480
481 netpoll_send_skb(np, skb);
482}
483EXPORT_SYMBOL(netpoll_send_udp);
484
485void netpoll_print_options(struct netpoll *np)
486{
487 np_info(np, "local port %d\n", np->local_port);
488 if (np->ipv6)
489 np_info(np, "local IPv6 address %pI6c\n", &np->local_ip.in6);
490 else
491 np_info(np, "local IPv4 address %pI4\n", &np->local_ip.ip);
492 np_info(np, "interface '%s'\n", np->dev_name);
493 np_info(np, "remote port %d\n", np->remote_port);
494 if (np->ipv6)
495 np_info(np, "remote IPv6 address %pI6c\n", &np->remote_ip.in6);
496 else
497 np_info(np, "remote IPv4 address %pI4\n", &np->remote_ip.ip);
498 np_info(np, "remote ethernet address %pM\n", np->remote_mac);
499}
500EXPORT_SYMBOL(netpoll_print_options);
501
502static int netpoll_parse_ip_addr(const char *str, union inet_addr *addr)
503{
504 const char *end;
505
506 if (!strchr(str, ':') &&
507 in4_pton(str, -1, (void *)addr, -1, &end) > 0) {
508 if (!*end)
509 return 0;
510 }
511 if (in6_pton(str, -1, addr->in6.s6_addr, -1, &end) > 0) {
512#if IS_ENABLED(CONFIG_IPV6)
513 if (!*end)
514 return 1;
515#else
516 return -1;
517#endif
518 }
519 return -1;
520}
521
522int netpoll_parse_options(struct netpoll *np, char *opt)
523{
524 char *cur=opt, *delim;
525 int ipv6;
526 bool ipversion_set = false;
527
528 if (*cur != '@') {
529 if ((delim = strchr(cur, '@')) == NULL)
530 goto parse_failed;
531 *delim = 0;
532 if (kstrtou16(cur, 10, &np->local_port))
533 goto parse_failed;
534 cur = delim;
535 }
536 cur++;
537
538 if (*cur != '/') {
539 ipversion_set = true;
540 if ((delim = strchr(cur, '/')) == NULL)
541 goto parse_failed;
542 *delim = 0;
543 ipv6 = netpoll_parse_ip_addr(cur, &np->local_ip);
544 if (ipv6 < 0)
545 goto parse_failed;
546 else
547 np->ipv6 = (bool)ipv6;
548 cur = delim;
549 }
550 cur++;
551
552 if (*cur != ',') {
553 /* parse out dev name */
554 if ((delim = strchr(cur, ',')) == NULL)
555 goto parse_failed;
556 *delim = 0;
557 strlcpy(np->dev_name, cur, sizeof(np->dev_name));
558 cur = delim;
559 }
560 cur++;
561
562 if (*cur != '@') {
563 /* dst port */
564 if ((delim = strchr(cur, '@')) == NULL)
565 goto parse_failed;
566 *delim = 0;
567 if (*cur == ' ' || *cur == '\t')
568 np_info(np, "warning: whitespace is not allowed\n");
569 if (kstrtou16(cur, 10, &np->remote_port))
570 goto parse_failed;
571 cur = delim;
572 }
573 cur++;
574
575 /* dst ip */
576 if ((delim = strchr(cur, '/')) == NULL)
577 goto parse_failed;
578 *delim = 0;
579 ipv6 = netpoll_parse_ip_addr(cur, &np->remote_ip);
580 if (ipv6 < 0)
581 goto parse_failed;
582 else if (ipversion_set && np->ipv6 != (bool)ipv6)
583 goto parse_failed;
584 else
585 np->ipv6 = (bool)ipv6;
586 cur = delim + 1;
587
588 if (*cur != 0) {
589 /* MAC address */
590 if (!mac_pton(cur, np->remote_mac))
591 goto parse_failed;
592 }
593
594 netpoll_print_options(np);
595
596 return 0;
597
598 parse_failed:
599 np_info(np, "couldn't parse config at '%s'!\n", cur);
600 return -1;
601}
602EXPORT_SYMBOL(netpoll_parse_options);
603
604int __netpoll_setup(struct netpoll *np, struct net_device *ndev)
605{
606 struct netpoll_info *npinfo;
607 const struct net_device_ops *ops;
608 int err;
609
610 np->dev = ndev;
611 strlcpy(np->dev_name, ndev->name, IFNAMSIZ);
612
613 if (ndev->priv_flags & IFF_DISABLE_NETPOLL) {
614 np_err(np, "%s doesn't support polling, aborting\n",
615 np->dev_name);
616 err = -ENOTSUPP;
617 goto out;
618 }
619
620 if (!ndev->npinfo) {
621 npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL);
622 if (!npinfo) {
623 err = -ENOMEM;
624 goto out;
625 }
626
627 sema_init(&npinfo->dev_lock, 1);
628 skb_queue_head_init(&npinfo->txq);
629 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process);
630
631 refcount_set(&npinfo->refcnt, 1);
632
633 ops = np->dev->netdev_ops;
634 if (ops->ndo_netpoll_setup) {
635 err = ops->ndo_netpoll_setup(ndev, npinfo);
636 if (err)
637 goto free_npinfo;
638 }
639 } else {
640 npinfo = rtnl_dereference(ndev->npinfo);
641 refcount_inc(&npinfo->refcnt);
642 }
643
644 npinfo->netpoll = np;
645
646 /* last thing to do is link it to the net device structure */
647 rcu_assign_pointer(ndev->npinfo, npinfo);
648
649 return 0;
650
651free_npinfo:
652 kfree(npinfo);
653out:
654 return err;
655}
656EXPORT_SYMBOL_GPL(__netpoll_setup);
657
658int netpoll_setup(struct netpoll *np)
659{
660 struct net_device *ndev = NULL;
661 struct in_device *in_dev;
662 int err;
663
664 rtnl_lock();
665 if (np->dev_name[0]) {
666 struct net *net = current->nsproxy->net_ns;
667 ndev = __dev_get_by_name(net, np->dev_name);
668 }
669 if (!ndev) {
670 np_err(np, "%s doesn't exist, aborting\n", np->dev_name);
671 err = -ENODEV;
672 goto unlock;
673 }
674 dev_hold(ndev);
675
676 if (netdev_master_upper_dev_get(ndev)) {
677 np_err(np, "%s is a slave device, aborting\n", np->dev_name);
678 err = -EBUSY;
679 goto put;
680 }
681
682 if (!netif_running(ndev)) {
683 unsigned long atmost, atleast;
684
685 np_info(np, "device %s not up yet, forcing it\n", np->dev_name);
686
687 err = dev_open(ndev, NULL);
688
689 if (err) {
690 np_err(np, "failed to open %s\n", ndev->name);
691 goto put;
692 }
693
694 rtnl_unlock();
695 atleast = jiffies + HZ/10;
696 atmost = jiffies + carrier_timeout * HZ;
697 while (!netif_carrier_ok(ndev)) {
698 if (time_after(jiffies, atmost)) {
699 np_notice(np, "timeout waiting for carrier\n");
700 break;
701 }
702 msleep(1);
703 }
704
705 /* If carrier appears to come up instantly, we don't
706 * trust it and pause so that we don't pump all our
707 * queued console messages into the bitbucket.
708 */
709
710 if (time_before(jiffies, atleast)) {
711 np_notice(np, "carrier detect appears untrustworthy, waiting 4 seconds\n");
712 msleep(4000);
713 }
714 rtnl_lock();
715 }
716
717 if (!np->local_ip.ip) {
718 if (!np->ipv6) {
719 const struct in_ifaddr *ifa;
720
721 in_dev = __in_dev_get_rtnl(ndev);
722 if (!in_dev)
723 goto put_noaddr;
724
725 ifa = rtnl_dereference(in_dev->ifa_list);
726 if (!ifa) {
727put_noaddr:
728 np_err(np, "no IP address for %s, aborting\n",
729 np->dev_name);
730 err = -EDESTADDRREQ;
731 goto put;
732 }
733
734 np->local_ip.ip = ifa->ifa_local;
735 np_info(np, "local IP %pI4\n", &np->local_ip.ip);
736 } else {
737#if IS_ENABLED(CONFIG_IPV6)
738 struct inet6_dev *idev;
739
740 err = -EDESTADDRREQ;
741 idev = __in6_dev_get(ndev);
742 if (idev) {
743 struct inet6_ifaddr *ifp;
744
745 read_lock_bh(&idev->lock);
746 list_for_each_entry(ifp, &idev->addr_list, if_list) {
747 if (!!(ipv6_addr_type(&ifp->addr) & IPV6_ADDR_LINKLOCAL) !=
748 !!(ipv6_addr_type(&np->remote_ip.in6) & IPV6_ADDR_LINKLOCAL))
749 continue;
750 np->local_ip.in6 = ifp->addr;
751 err = 0;
752 break;
753 }
754 read_unlock_bh(&idev->lock);
755 }
756 if (err) {
757 np_err(np, "no IPv6 address for %s, aborting\n",
758 np->dev_name);
759 goto put;
760 } else
761 np_info(np, "local IPv6 %pI6c\n", &np->local_ip.in6);
762#else
763 np_err(np, "IPv6 is not supported %s, aborting\n",
764 np->dev_name);
765 err = -EINVAL;
766 goto put;
767#endif
768 }
769 }
770
771 /* fill up the skb queue */
772 refill_skbs();
773
774 err = __netpoll_setup(np, ndev);
775 if (err)
776 goto put;
777
778 rtnl_unlock();
779 return 0;
780
781put:
782 dev_put(ndev);
783unlock:
784 rtnl_unlock();
785 return err;
786}
787EXPORT_SYMBOL(netpoll_setup);
788
789static int __init netpoll_init(void)
790{
791 skb_queue_head_init(&skb_pool);
792 return 0;
793}
794core_initcall(netpoll_init);
795
796static void rcu_cleanup_netpoll_info(struct rcu_head *rcu_head)
797{
798 struct netpoll_info *npinfo =
799 container_of(rcu_head, struct netpoll_info, rcu);
800
801 skb_queue_purge(&npinfo->txq);
802
803 /* we can't call cancel_delayed_work_sync here, as we are in softirq */
804 cancel_delayed_work(&npinfo->tx_work);
805
806 /* clean after last, unfinished work */
807 __skb_queue_purge(&npinfo->txq);
808 /* now cancel it again */
809 cancel_delayed_work(&npinfo->tx_work);
810 kfree(npinfo);
811}
812
813void __netpoll_cleanup(struct netpoll *np)
814{
815 struct netpoll_info *npinfo;
816
817 npinfo = rtnl_dereference(np->dev->npinfo);
818 if (!npinfo)
819 return;
820
821 synchronize_srcu(&netpoll_srcu);
822
823 if (refcount_dec_and_test(&npinfo->refcnt)) {
824 const struct net_device_ops *ops;
825
826 ops = np->dev->netdev_ops;
827 if (ops->ndo_netpoll_cleanup)
828 ops->ndo_netpoll_cleanup(np->dev);
829
830 RCU_INIT_POINTER(np->dev->npinfo, NULL);
831 call_rcu(&npinfo->rcu, rcu_cleanup_netpoll_info);
832 } else
833 RCU_INIT_POINTER(np->dev->npinfo, NULL);
834}
835EXPORT_SYMBOL_GPL(__netpoll_cleanup);
836
837void __netpoll_free(struct netpoll *np)
838{
839 ASSERT_RTNL();
840
841 /* Wait for transmitting packets to finish before freeing. */
842 synchronize_rcu();
843 __netpoll_cleanup(np);
844 kfree(np);
845}
846EXPORT_SYMBOL_GPL(__netpoll_free);
847
848void netpoll_cleanup(struct netpoll *np)
849{
850 rtnl_lock();
851 if (!np->dev)
852 goto out;
853 __netpoll_cleanup(np);
854 dev_put(np->dev);
855 np->dev = NULL;
856out:
857 rtnl_unlock();
858}
859EXPORT_SYMBOL(netpoll_cleanup);