Loading...
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 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
161static 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
174void 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}
201EXPORT_SYMBOL(netpoll_poll_dev);
202
203void 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}
214EXPORT_SYMBOL(netpoll_poll_disable);
215
216void 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}
225EXPORT_SYMBOL(netpoll_poll_enable);
226
227static 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
243static 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
271static 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();
278repeat:
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
297static 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 */
309static 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
366netdev_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}
381EXPORT_SYMBOL(netpoll_send_skb);
382
383void 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 if (!IS_ENABLED(CONFIG_PREEMPT_RT))
394 WARN_ON_ONCE(!irqs_disabled());
395
396 udp_len = len + sizeof(*udph);
397 if (np->ipv6)
398 ip_len = udp_len + sizeof(*ip6h);
399 else
400 ip_len = udp_len + sizeof(*iph);
401
402 total_len = ip_len + LL_RESERVED_SPACE(np->dev);
403
404 skb = find_skb(np, total_len + np->dev->needed_tailroom,
405 total_len - len);
406 if (!skb)
407 return;
408
409 skb_copy_to_linear_data(skb, msg, len);
410 skb_put(skb, len);
411
412 skb_push(skb, sizeof(*udph));
413 skb_reset_transport_header(skb);
414 udph = udp_hdr(skb);
415 udph->source = htons(np->local_port);
416 udph->dest = htons(np->remote_port);
417 udph->len = htons(udp_len);
418
419 if (np->ipv6) {
420 udph->check = 0;
421 udph->check = csum_ipv6_magic(&np->local_ip.in6,
422 &np->remote_ip.in6,
423 udp_len, IPPROTO_UDP,
424 csum_partial(udph, udp_len, 0));
425 if (udph->check == 0)
426 udph->check = CSUM_MANGLED_0;
427
428 skb_push(skb, sizeof(*ip6h));
429 skb_reset_network_header(skb);
430 ip6h = ipv6_hdr(skb);
431
432 /* ip6h->version = 6; ip6h->priority = 0; */
433 *(unsigned char *)ip6h = 0x60;
434 ip6h->flow_lbl[0] = 0;
435 ip6h->flow_lbl[1] = 0;
436 ip6h->flow_lbl[2] = 0;
437
438 ip6h->payload_len = htons(sizeof(struct udphdr) + len);
439 ip6h->nexthdr = IPPROTO_UDP;
440 ip6h->hop_limit = 32;
441 ip6h->saddr = np->local_ip.in6;
442 ip6h->daddr = np->remote_ip.in6;
443
444 eth = skb_push(skb, ETH_HLEN);
445 skb_reset_mac_header(skb);
446 skb->protocol = eth->h_proto = htons(ETH_P_IPV6);
447 } else {
448 udph->check = 0;
449 udph->check = csum_tcpudp_magic(np->local_ip.ip,
450 np->remote_ip.ip,
451 udp_len, IPPROTO_UDP,
452 csum_partial(udph, udp_len, 0));
453 if (udph->check == 0)
454 udph->check = CSUM_MANGLED_0;
455
456 skb_push(skb, sizeof(*iph));
457 skb_reset_network_header(skb);
458 iph = ip_hdr(skb);
459
460 /* iph->version = 4; iph->ihl = 5; */
461 *(unsigned char *)iph = 0x45;
462 iph->tos = 0;
463 put_unaligned(htons(ip_len), &(iph->tot_len));
464 iph->id = htons(atomic_inc_return(&ip_ident));
465 iph->frag_off = 0;
466 iph->ttl = 64;
467 iph->protocol = IPPROTO_UDP;
468 iph->check = 0;
469 put_unaligned(np->local_ip.ip, &(iph->saddr));
470 put_unaligned(np->remote_ip.ip, &(iph->daddr));
471 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl);
472
473 eth = skb_push(skb, ETH_HLEN);
474 skb_reset_mac_header(skb);
475 skb->protocol = eth->h_proto = htons(ETH_P_IP);
476 }
477
478 ether_addr_copy(eth->h_source, np->dev->dev_addr);
479 ether_addr_copy(eth->h_dest, np->remote_mac);
480
481 skb->dev = np->dev;
482
483 netpoll_send_skb(np, skb);
484}
485EXPORT_SYMBOL(netpoll_send_udp);
486
487void netpoll_print_options(struct netpoll *np)
488{
489 np_info(np, "local port %d\n", np->local_port);
490 if (np->ipv6)
491 np_info(np, "local IPv6 address %pI6c\n", &np->local_ip.in6);
492 else
493 np_info(np, "local IPv4 address %pI4\n", &np->local_ip.ip);
494 np_info(np, "interface '%s'\n", np->dev_name);
495 np_info(np, "remote port %d\n", np->remote_port);
496 if (np->ipv6)
497 np_info(np, "remote IPv6 address %pI6c\n", &np->remote_ip.in6);
498 else
499 np_info(np, "remote IPv4 address %pI4\n", &np->remote_ip.ip);
500 np_info(np, "remote ethernet address %pM\n", np->remote_mac);
501}
502EXPORT_SYMBOL(netpoll_print_options);
503
504static int netpoll_parse_ip_addr(const char *str, union inet_addr *addr)
505{
506 const char *end;
507
508 if (!strchr(str, ':') &&
509 in4_pton(str, -1, (void *)addr, -1, &end) > 0) {
510 if (!*end)
511 return 0;
512 }
513 if (in6_pton(str, -1, addr->in6.s6_addr, -1, &end) > 0) {
514#if IS_ENABLED(CONFIG_IPV6)
515 if (!*end)
516 return 1;
517#else
518 return -1;
519#endif
520 }
521 return -1;
522}
523
524int netpoll_parse_options(struct netpoll *np, char *opt)
525{
526 char *cur=opt, *delim;
527 int ipv6;
528 bool ipversion_set = false;
529
530 if (*cur != '@') {
531 if ((delim = strchr(cur, '@')) == NULL)
532 goto parse_failed;
533 *delim = 0;
534 if (kstrtou16(cur, 10, &np->local_port))
535 goto parse_failed;
536 cur = delim;
537 }
538 cur++;
539
540 if (*cur != '/') {
541 ipversion_set = true;
542 if ((delim = strchr(cur, '/')) == NULL)
543 goto parse_failed;
544 *delim = 0;
545 ipv6 = netpoll_parse_ip_addr(cur, &np->local_ip);
546 if (ipv6 < 0)
547 goto parse_failed;
548 else
549 np->ipv6 = (bool)ipv6;
550 cur = delim;
551 }
552 cur++;
553
554 if (*cur != ',') {
555 /* parse out dev name */
556 if ((delim = strchr(cur, ',')) == NULL)
557 goto parse_failed;
558 *delim = 0;
559 strlcpy(np->dev_name, cur, sizeof(np->dev_name));
560 cur = delim;
561 }
562 cur++;
563
564 if (*cur != '@') {
565 /* dst port */
566 if ((delim = strchr(cur, '@')) == NULL)
567 goto parse_failed;
568 *delim = 0;
569 if (*cur == ' ' || *cur == '\t')
570 np_info(np, "warning: whitespace is not allowed\n");
571 if (kstrtou16(cur, 10, &np->remote_port))
572 goto parse_failed;
573 cur = delim;
574 }
575 cur++;
576
577 /* dst ip */
578 if ((delim = strchr(cur, '/')) == NULL)
579 goto parse_failed;
580 *delim = 0;
581 ipv6 = netpoll_parse_ip_addr(cur, &np->remote_ip);
582 if (ipv6 < 0)
583 goto parse_failed;
584 else if (ipversion_set && np->ipv6 != (bool)ipv6)
585 goto parse_failed;
586 else
587 np->ipv6 = (bool)ipv6;
588 cur = delim + 1;
589
590 if (*cur != 0) {
591 /* MAC address */
592 if (!mac_pton(cur, np->remote_mac))
593 goto parse_failed;
594 }
595
596 netpoll_print_options(np);
597
598 return 0;
599
600 parse_failed:
601 np_info(np, "couldn't parse config at '%s'!\n", cur);
602 return -1;
603}
604EXPORT_SYMBOL(netpoll_parse_options);
605
606int __netpoll_setup(struct netpoll *np, struct net_device *ndev)
607{
608 struct netpoll_info *npinfo;
609 const struct net_device_ops *ops;
610 int err;
611
612 np->dev = ndev;
613 strlcpy(np->dev_name, ndev->name, IFNAMSIZ);
614
615 if (ndev->priv_flags & IFF_DISABLE_NETPOLL) {
616 np_err(np, "%s doesn't support polling, aborting\n",
617 np->dev_name);
618 err = -ENOTSUPP;
619 goto out;
620 }
621
622 if (!ndev->npinfo) {
623 npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL);
624 if (!npinfo) {
625 err = -ENOMEM;
626 goto out;
627 }
628
629 sema_init(&npinfo->dev_lock, 1);
630 skb_queue_head_init(&npinfo->txq);
631 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process);
632
633 refcount_set(&npinfo->refcnt, 1);
634
635 ops = np->dev->netdev_ops;
636 if (ops->ndo_netpoll_setup) {
637 err = ops->ndo_netpoll_setup(ndev, npinfo);
638 if (err)
639 goto free_npinfo;
640 }
641 } else {
642 npinfo = rtnl_dereference(ndev->npinfo);
643 refcount_inc(&npinfo->refcnt);
644 }
645
646 npinfo->netpoll = np;
647
648 /* last thing to do is link it to the net device structure */
649 rcu_assign_pointer(ndev->npinfo, npinfo);
650
651 return 0;
652
653free_npinfo:
654 kfree(npinfo);
655out:
656 return err;
657}
658EXPORT_SYMBOL_GPL(__netpoll_setup);
659
660int netpoll_setup(struct netpoll *np)
661{
662 struct net_device *ndev = NULL;
663 struct in_device *in_dev;
664 int err;
665
666 rtnl_lock();
667 if (np->dev_name[0]) {
668 struct net *net = current->nsproxy->net_ns;
669 ndev = __dev_get_by_name(net, np->dev_name);
670 }
671 if (!ndev) {
672 np_err(np, "%s doesn't exist, aborting\n", np->dev_name);
673 err = -ENODEV;
674 goto unlock;
675 }
676 dev_hold(ndev);
677
678 if (netdev_master_upper_dev_get(ndev)) {
679 np_err(np, "%s is a slave device, aborting\n", np->dev_name);
680 err = -EBUSY;
681 goto put;
682 }
683
684 if (!netif_running(ndev)) {
685 unsigned long atmost, atleast;
686
687 np_info(np, "device %s not up yet, forcing it\n", np->dev_name);
688
689 err = dev_open(ndev, NULL);
690
691 if (err) {
692 np_err(np, "failed to open %s\n", ndev->name);
693 goto put;
694 }
695
696 rtnl_unlock();
697 atleast = jiffies + HZ/10;
698 atmost = jiffies + carrier_timeout * HZ;
699 while (!netif_carrier_ok(ndev)) {
700 if (time_after(jiffies, atmost)) {
701 np_notice(np, "timeout waiting for carrier\n");
702 break;
703 }
704 msleep(1);
705 }
706
707 /* If carrier appears to come up instantly, we don't
708 * trust it and pause so that we don't pump all our
709 * queued console messages into the bitbucket.
710 */
711
712 if (time_before(jiffies, atleast)) {
713 np_notice(np, "carrier detect appears untrustworthy, waiting 4 seconds\n");
714 msleep(4000);
715 }
716 rtnl_lock();
717 }
718
719 if (!np->local_ip.ip) {
720 if (!np->ipv6) {
721 const struct in_ifaddr *ifa;
722
723 in_dev = __in_dev_get_rtnl(ndev);
724 if (!in_dev)
725 goto put_noaddr;
726
727 ifa = rtnl_dereference(in_dev->ifa_list);
728 if (!ifa) {
729put_noaddr:
730 np_err(np, "no IP address for %s, aborting\n",
731 np->dev_name);
732 err = -EDESTADDRREQ;
733 goto put;
734 }
735
736 np->local_ip.ip = ifa->ifa_local;
737 np_info(np, "local IP %pI4\n", &np->local_ip.ip);
738 } else {
739#if IS_ENABLED(CONFIG_IPV6)
740 struct inet6_dev *idev;
741
742 err = -EDESTADDRREQ;
743 idev = __in6_dev_get(ndev);
744 if (idev) {
745 struct inet6_ifaddr *ifp;
746
747 read_lock_bh(&idev->lock);
748 list_for_each_entry(ifp, &idev->addr_list, if_list) {
749 if (!!(ipv6_addr_type(&ifp->addr) & IPV6_ADDR_LINKLOCAL) !=
750 !!(ipv6_addr_type(&np->remote_ip.in6) & IPV6_ADDR_LINKLOCAL))
751 continue;
752 np->local_ip.in6 = ifp->addr;
753 err = 0;
754 break;
755 }
756 read_unlock_bh(&idev->lock);
757 }
758 if (err) {
759 np_err(np, "no IPv6 address for %s, aborting\n",
760 np->dev_name);
761 goto put;
762 } else
763 np_info(np, "local IPv6 %pI6c\n", &np->local_ip.in6);
764#else
765 np_err(np, "IPv6 is not supported %s, aborting\n",
766 np->dev_name);
767 err = -EINVAL;
768 goto put;
769#endif
770 }
771 }
772
773 /* fill up the skb queue */
774 refill_skbs();
775
776 err = __netpoll_setup(np, ndev);
777 if (err)
778 goto put;
779
780 rtnl_unlock();
781 return 0;
782
783put:
784 dev_put(ndev);
785unlock:
786 rtnl_unlock();
787 return err;
788}
789EXPORT_SYMBOL(netpoll_setup);
790
791static int __init netpoll_init(void)
792{
793 skb_queue_head_init(&skb_pool);
794 return 0;
795}
796core_initcall(netpoll_init);
797
798static void rcu_cleanup_netpoll_info(struct rcu_head *rcu_head)
799{
800 struct netpoll_info *npinfo =
801 container_of(rcu_head, struct netpoll_info, rcu);
802
803 skb_queue_purge(&npinfo->txq);
804
805 /* we can't call cancel_delayed_work_sync here, as we are in softirq */
806 cancel_delayed_work(&npinfo->tx_work);
807
808 /* clean after last, unfinished work */
809 __skb_queue_purge(&npinfo->txq);
810 /* now cancel it again */
811 cancel_delayed_work(&npinfo->tx_work);
812 kfree(npinfo);
813}
814
815void __netpoll_cleanup(struct netpoll *np)
816{
817 struct netpoll_info *npinfo;
818
819 npinfo = rtnl_dereference(np->dev->npinfo);
820 if (!npinfo)
821 return;
822
823 synchronize_srcu(&netpoll_srcu);
824
825 if (refcount_dec_and_test(&npinfo->refcnt)) {
826 const struct net_device_ops *ops;
827
828 ops = np->dev->netdev_ops;
829 if (ops->ndo_netpoll_cleanup)
830 ops->ndo_netpoll_cleanup(np->dev);
831
832 RCU_INIT_POINTER(np->dev->npinfo, NULL);
833 call_rcu(&npinfo->rcu, rcu_cleanup_netpoll_info);
834 } else
835 RCU_INIT_POINTER(np->dev->npinfo, NULL);
836}
837EXPORT_SYMBOL_GPL(__netpoll_cleanup);
838
839void __netpoll_free(struct netpoll *np)
840{
841 ASSERT_RTNL();
842
843 /* Wait for transmitting packets to finish before freeing. */
844 synchronize_rcu();
845 __netpoll_cleanup(np);
846 kfree(np);
847}
848EXPORT_SYMBOL_GPL(__netpoll_free);
849
850void netpoll_cleanup(struct netpoll *np)
851{
852 rtnl_lock();
853 if (!np->dev)
854 goto out;
855 __netpoll_cleanup(np);
856 dev_put(np->dev);
857 np->dev = NULL;
858out:
859 rtnl_unlock();
860}
861EXPORT_SYMBOL(netpoll_cleanup);
1/*
2 * Common framework for low-level network console, dump, and debugger code
3 *
4 * Sep 8 2003 Matt Mackall <mpm@selenic.com>
5 *
6 * based on the netconsole code from:
7 *
8 * Copyright (C) 2001 Ingo Molnar <mingo@redhat.com>
9 * Copyright (C) 2002 Red Hat, Inc.
10 */
11
12#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13
14#include <linux/moduleparam.h>
15#include <linux/kernel.h>
16#include <linux/netdevice.h>
17#include <linux/etherdevice.h>
18#include <linux/string.h>
19#include <linux/if_arp.h>
20#include <linux/inetdevice.h>
21#include <linux/inet.h>
22#include <linux/interrupt.h>
23#include <linux/netpoll.h>
24#include <linux/sched.h>
25#include <linux/delay.h>
26#include <linux/rcupdate.h>
27#include <linux/workqueue.h>
28#include <linux/slab.h>
29#include <linux/export.h>
30#include <linux/if_vlan.h>
31#include <net/tcp.h>
32#include <net/udp.h>
33#include <net/addrconf.h>
34#include <net/ndisc.h>
35#include <net/ip6_checksum.h>
36#include <asm/unaligned.h>
37#include <trace/events/napi.h>
38
39/*
40 * We maintain a small pool of fully-sized skbs, to make sure the
41 * message gets out even in extreme OOM situations.
42 */
43
44#define MAX_UDP_CHUNK 1460
45#define MAX_SKBS 32
46
47static struct sk_buff_head skb_pool;
48
49DEFINE_STATIC_SRCU(netpoll_srcu);
50
51#define USEC_PER_POLL 50
52
53#define MAX_SKB_SIZE \
54 (sizeof(struct ethhdr) + \
55 sizeof(struct iphdr) + \
56 sizeof(struct udphdr) + \
57 MAX_UDP_CHUNK)
58
59static void zap_completion_queue(void);
60static void netpoll_async_cleanup(struct work_struct *work);
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 int netpoll_start_xmit(struct sk_buff *skb, struct net_device *dev,
73 struct netdev_queue *txq)
74{
75 int status = NETDEV_TX_OK;
76 netdev_features_t features;
77
78 features = netif_skb_features(skb);
79
80 if (skb_vlan_tag_present(skb) &&
81 !vlan_hw_offload_capable(features, skb->vlan_proto)) {
82 skb = __vlan_hwaccel_push_inside(skb);
83 if (unlikely(!skb)) {
84 /* This is actually a packet drop, but we
85 * don't want the code that calls this
86 * function to try and operate on a NULL skb.
87 */
88 goto out;
89 }
90 }
91
92 status = netdev_start_xmit(skb, dev, txq, false);
93
94out:
95 return status;
96}
97
98static void queue_process(struct work_struct *work)
99{
100 struct netpoll_info *npinfo =
101 container_of(work, struct netpoll_info, tx_work.work);
102 struct sk_buff *skb;
103 unsigned long flags;
104
105 while ((skb = skb_dequeue(&npinfo->txq))) {
106 struct net_device *dev = skb->dev;
107 struct netdev_queue *txq;
108 unsigned int q_index;
109
110 if (!netif_device_present(dev) || !netif_running(dev)) {
111 kfree_skb(skb);
112 continue;
113 }
114
115 local_irq_save(flags);
116 /* check if skb->queue_mapping is still valid */
117 q_index = skb_get_queue_mapping(skb);
118 if (unlikely(q_index >= dev->real_num_tx_queues)) {
119 q_index = q_index % dev->real_num_tx_queues;
120 skb_set_queue_mapping(skb, q_index);
121 }
122 txq = netdev_get_tx_queue(dev, q_index);
123 HARD_TX_LOCK(dev, txq, smp_processor_id());
124 if (netif_xmit_frozen_or_stopped(txq) ||
125 netpoll_start_xmit(skb, dev, txq) != NETDEV_TX_OK) {
126 skb_queue_head(&npinfo->txq, skb);
127 HARD_TX_UNLOCK(dev, txq);
128 local_irq_restore(flags);
129
130 schedule_delayed_work(&npinfo->tx_work, HZ/10);
131 return;
132 }
133 HARD_TX_UNLOCK(dev, txq);
134 local_irq_restore(flags);
135 }
136}
137
138/*
139 * Check whether delayed processing was scheduled for our NIC. If so,
140 * we attempt to grab the poll lock and use ->poll() to pump the card.
141 * If this fails, either we've recursed in ->poll() or it's already
142 * running on another CPU.
143 *
144 * Note: we don't mask interrupts with this lock because we're using
145 * trylock here and interrupts are already disabled in the softirq
146 * case. Further, we test the poll_owner to avoid recursion on UP
147 * systems where the lock doesn't exist.
148 */
149static void poll_one_napi(struct napi_struct *napi)
150{
151 int work = 0;
152
153 /* net_rx_action's ->poll() invocations and our's are
154 * synchronized by this test which is only made while
155 * holding the napi->poll_lock.
156 */
157 if (!test_bit(NAPI_STATE_SCHED, &napi->state))
158 return;
159
160 /* If we set this bit but see that it has already been set,
161 * that indicates that napi has been disabled and we need
162 * to abort this operation
163 */
164 if (test_and_set_bit(NAPI_STATE_NPSVC, &napi->state))
165 return;
166
167 /* We explicilty pass the polling call a budget of 0 to
168 * indicate that we are clearing the Tx path only.
169 */
170 work = napi->poll(napi, 0);
171 WARN_ONCE(work, "%pF exceeded budget in poll\n", napi->poll);
172 trace_napi_poll(napi, work, 0);
173
174 clear_bit(NAPI_STATE_NPSVC, &napi->state);
175}
176
177static void poll_napi(struct net_device *dev)
178{
179 struct napi_struct *napi;
180 int cpu = smp_processor_id();
181
182 list_for_each_entry(napi, &dev->napi_list, dev_list) {
183 if (cmpxchg(&napi->poll_owner, -1, cpu) == -1) {
184 poll_one_napi(napi);
185 smp_store_release(&napi->poll_owner, -1);
186 }
187 }
188}
189
190static void netpoll_poll_dev(struct net_device *dev)
191{
192 const struct net_device_ops *ops;
193 struct netpoll_info *ni = rcu_dereference_bh(dev->npinfo);
194
195 /* Don't do any rx activity if the dev_lock mutex is held
196 * the dev_open/close paths use this to block netpoll activity
197 * while changing device state
198 */
199 if (down_trylock(&ni->dev_lock))
200 return;
201
202 if (!netif_running(dev)) {
203 up(&ni->dev_lock);
204 return;
205 }
206
207 ops = dev->netdev_ops;
208 if (!ops->ndo_poll_controller) {
209 up(&ni->dev_lock);
210 return;
211 }
212
213 /* Process pending work on NIC */
214 ops->ndo_poll_controller(dev);
215
216 poll_napi(dev);
217
218 up(&ni->dev_lock);
219
220 zap_completion_queue();
221}
222
223void netpoll_poll_disable(struct net_device *dev)
224{
225 struct netpoll_info *ni;
226 int idx;
227 might_sleep();
228 idx = srcu_read_lock(&netpoll_srcu);
229 ni = srcu_dereference(dev->npinfo, &netpoll_srcu);
230 if (ni)
231 down(&ni->dev_lock);
232 srcu_read_unlock(&netpoll_srcu, idx);
233}
234EXPORT_SYMBOL(netpoll_poll_disable);
235
236void netpoll_poll_enable(struct net_device *dev)
237{
238 struct netpoll_info *ni;
239 rcu_read_lock();
240 ni = rcu_dereference(dev->npinfo);
241 if (ni)
242 up(&ni->dev_lock);
243 rcu_read_unlock();
244}
245EXPORT_SYMBOL(netpoll_poll_enable);
246
247static void refill_skbs(void)
248{
249 struct sk_buff *skb;
250 unsigned long flags;
251
252 spin_lock_irqsave(&skb_pool.lock, flags);
253 while (skb_pool.qlen < MAX_SKBS) {
254 skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC);
255 if (!skb)
256 break;
257
258 __skb_queue_tail(&skb_pool, skb);
259 }
260 spin_unlock_irqrestore(&skb_pool.lock, flags);
261}
262
263static void zap_completion_queue(void)
264{
265 unsigned long flags;
266 struct softnet_data *sd = &get_cpu_var(softnet_data);
267
268 if (sd->completion_queue) {
269 struct sk_buff *clist;
270
271 local_irq_save(flags);
272 clist = sd->completion_queue;
273 sd->completion_queue = NULL;
274 local_irq_restore(flags);
275
276 while (clist != NULL) {
277 struct sk_buff *skb = clist;
278 clist = clist->next;
279 if (!skb_irq_freeable(skb)) {
280 refcount_set(&skb->users, 1);
281 dev_kfree_skb_any(skb); /* put this one back */
282 } else {
283 __kfree_skb(skb);
284 }
285 }
286 }
287
288 put_cpu_var(softnet_data);
289}
290
291static struct sk_buff *find_skb(struct netpoll *np, int len, int reserve)
292{
293 int count = 0;
294 struct sk_buff *skb;
295
296 zap_completion_queue();
297 refill_skbs();
298repeat:
299
300 skb = alloc_skb(len, GFP_ATOMIC);
301 if (!skb)
302 skb = skb_dequeue(&skb_pool);
303
304 if (!skb) {
305 if (++count < 10) {
306 netpoll_poll_dev(np->dev);
307 goto repeat;
308 }
309 return NULL;
310 }
311
312 refcount_set(&skb->users, 1);
313 skb_reserve(skb, reserve);
314 return skb;
315}
316
317static int netpoll_owner_active(struct net_device *dev)
318{
319 struct napi_struct *napi;
320
321 list_for_each_entry(napi, &dev->napi_list, dev_list) {
322 if (napi->poll_owner == smp_processor_id())
323 return 1;
324 }
325 return 0;
326}
327
328/* call with IRQ disabled */
329void netpoll_send_skb_on_dev(struct netpoll *np, struct sk_buff *skb,
330 struct net_device *dev)
331{
332 int status = NETDEV_TX_BUSY;
333 unsigned long tries;
334 /* It is up to the caller to keep npinfo alive. */
335 struct netpoll_info *npinfo;
336
337 lockdep_assert_irqs_disabled();
338
339 npinfo = rcu_dereference_bh(np->dev->npinfo);
340 if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) {
341 dev_kfree_skb_irq(skb);
342 return;
343 }
344
345 /* don't get messages out of order, and no recursion */
346 if (skb_queue_len(&npinfo->txq) == 0 && !netpoll_owner_active(dev)) {
347 struct netdev_queue *txq;
348
349 txq = netdev_pick_tx(dev, skb, NULL);
350
351 /* try until next clock tick */
352 for (tries = jiffies_to_usecs(1)/USEC_PER_POLL;
353 tries > 0; --tries) {
354 if (HARD_TX_TRYLOCK(dev, txq)) {
355 if (!netif_xmit_stopped(txq))
356 status = netpoll_start_xmit(skb, dev, txq);
357
358 HARD_TX_UNLOCK(dev, txq);
359
360 if (status == NETDEV_TX_OK)
361 break;
362
363 }
364
365 /* tickle device maybe there is some cleanup */
366 netpoll_poll_dev(np->dev);
367
368 udelay(USEC_PER_POLL);
369 }
370
371 WARN_ONCE(!irqs_disabled(),
372 "netpoll_send_skb_on_dev(): %s enabled interrupts in poll (%pF)\n",
373 dev->name, dev->netdev_ops->ndo_start_xmit);
374
375 }
376
377 if (status != NETDEV_TX_OK) {
378 skb_queue_tail(&npinfo->txq, skb);
379 schedule_delayed_work(&npinfo->tx_work,0);
380 }
381}
382EXPORT_SYMBOL(netpoll_send_skb_on_dev);
383
384void netpoll_send_udp(struct netpoll *np, const char *msg, int len)
385{
386 int total_len, ip_len, udp_len;
387 struct sk_buff *skb;
388 struct udphdr *udph;
389 struct iphdr *iph;
390 struct ethhdr *eth;
391 static atomic_t ip_ident;
392 struct ipv6hdr *ip6h;
393
394 WARN_ON_ONCE(!irqs_disabled());
395
396 udp_len = len + sizeof(*udph);
397 if (np->ipv6)
398 ip_len = udp_len + sizeof(*ip6h);
399 else
400 ip_len = udp_len + sizeof(*iph);
401
402 total_len = ip_len + LL_RESERVED_SPACE(np->dev);
403
404 skb = find_skb(np, total_len + np->dev->needed_tailroom,
405 total_len - len);
406 if (!skb)
407 return;
408
409 skb_copy_to_linear_data(skb, msg, len);
410 skb_put(skb, len);
411
412 skb_push(skb, sizeof(*udph));
413 skb_reset_transport_header(skb);
414 udph = udp_hdr(skb);
415 udph->source = htons(np->local_port);
416 udph->dest = htons(np->remote_port);
417 udph->len = htons(udp_len);
418
419 if (np->ipv6) {
420 udph->check = 0;
421 udph->check = csum_ipv6_magic(&np->local_ip.in6,
422 &np->remote_ip.in6,
423 udp_len, IPPROTO_UDP,
424 csum_partial(udph, udp_len, 0));
425 if (udph->check == 0)
426 udph->check = CSUM_MANGLED_0;
427
428 skb_push(skb, sizeof(*ip6h));
429 skb_reset_network_header(skb);
430 ip6h = ipv6_hdr(skb);
431
432 /* ip6h->version = 6; ip6h->priority = 0; */
433 put_unaligned(0x60, (unsigned char *)ip6h);
434 ip6h->flow_lbl[0] = 0;
435 ip6h->flow_lbl[1] = 0;
436 ip6h->flow_lbl[2] = 0;
437
438 ip6h->payload_len = htons(sizeof(struct udphdr) + len);
439 ip6h->nexthdr = IPPROTO_UDP;
440 ip6h->hop_limit = 32;
441 ip6h->saddr = np->local_ip.in6;
442 ip6h->daddr = np->remote_ip.in6;
443
444 eth = skb_push(skb, ETH_HLEN);
445 skb_reset_mac_header(skb);
446 skb->protocol = eth->h_proto = htons(ETH_P_IPV6);
447 } else {
448 udph->check = 0;
449 udph->check = csum_tcpudp_magic(np->local_ip.ip,
450 np->remote_ip.ip,
451 udp_len, IPPROTO_UDP,
452 csum_partial(udph, udp_len, 0));
453 if (udph->check == 0)
454 udph->check = CSUM_MANGLED_0;
455
456 skb_push(skb, sizeof(*iph));
457 skb_reset_network_header(skb);
458 iph = ip_hdr(skb);
459
460 /* iph->version = 4; iph->ihl = 5; */
461 put_unaligned(0x45, (unsigned char *)iph);
462 iph->tos = 0;
463 put_unaligned(htons(ip_len), &(iph->tot_len));
464 iph->id = htons(atomic_inc_return(&ip_ident));
465 iph->frag_off = 0;
466 iph->ttl = 64;
467 iph->protocol = IPPROTO_UDP;
468 iph->check = 0;
469 put_unaligned(np->local_ip.ip, &(iph->saddr));
470 put_unaligned(np->remote_ip.ip, &(iph->daddr));
471 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl);
472
473 eth = skb_push(skb, ETH_HLEN);
474 skb_reset_mac_header(skb);
475 skb->protocol = eth->h_proto = htons(ETH_P_IP);
476 }
477
478 ether_addr_copy(eth->h_source, np->dev->dev_addr);
479 ether_addr_copy(eth->h_dest, np->remote_mac);
480
481 skb->dev = np->dev;
482
483 netpoll_send_skb(np, skb);
484}
485EXPORT_SYMBOL(netpoll_send_udp);
486
487void netpoll_print_options(struct netpoll *np)
488{
489 np_info(np, "local port %d\n", np->local_port);
490 if (np->ipv6)
491 np_info(np, "local IPv6 address %pI6c\n", &np->local_ip.in6);
492 else
493 np_info(np, "local IPv4 address %pI4\n", &np->local_ip.ip);
494 np_info(np, "interface '%s'\n", np->dev_name);
495 np_info(np, "remote port %d\n", np->remote_port);
496 if (np->ipv6)
497 np_info(np, "remote IPv6 address %pI6c\n", &np->remote_ip.in6);
498 else
499 np_info(np, "remote IPv4 address %pI4\n", &np->remote_ip.ip);
500 np_info(np, "remote ethernet address %pM\n", np->remote_mac);
501}
502EXPORT_SYMBOL(netpoll_print_options);
503
504static int netpoll_parse_ip_addr(const char *str, union inet_addr *addr)
505{
506 const char *end;
507
508 if (!strchr(str, ':') &&
509 in4_pton(str, -1, (void *)addr, -1, &end) > 0) {
510 if (!*end)
511 return 0;
512 }
513 if (in6_pton(str, -1, addr->in6.s6_addr, -1, &end) > 0) {
514#if IS_ENABLED(CONFIG_IPV6)
515 if (!*end)
516 return 1;
517#else
518 return -1;
519#endif
520 }
521 return -1;
522}
523
524int netpoll_parse_options(struct netpoll *np, char *opt)
525{
526 char *cur=opt, *delim;
527 int ipv6;
528 bool ipversion_set = false;
529
530 if (*cur != '@') {
531 if ((delim = strchr(cur, '@')) == NULL)
532 goto parse_failed;
533 *delim = 0;
534 if (kstrtou16(cur, 10, &np->local_port))
535 goto parse_failed;
536 cur = delim;
537 }
538 cur++;
539
540 if (*cur != '/') {
541 ipversion_set = true;
542 if ((delim = strchr(cur, '/')) == NULL)
543 goto parse_failed;
544 *delim = 0;
545 ipv6 = netpoll_parse_ip_addr(cur, &np->local_ip);
546 if (ipv6 < 0)
547 goto parse_failed;
548 else
549 np->ipv6 = (bool)ipv6;
550 cur = delim;
551 }
552 cur++;
553
554 if (*cur != ',') {
555 /* parse out dev name */
556 if ((delim = strchr(cur, ',')) == NULL)
557 goto parse_failed;
558 *delim = 0;
559 strlcpy(np->dev_name, cur, sizeof(np->dev_name));
560 cur = delim;
561 }
562 cur++;
563
564 if (*cur != '@') {
565 /* dst port */
566 if ((delim = strchr(cur, '@')) == NULL)
567 goto parse_failed;
568 *delim = 0;
569 if (*cur == ' ' || *cur == '\t')
570 np_info(np, "warning: whitespace is not allowed\n");
571 if (kstrtou16(cur, 10, &np->remote_port))
572 goto parse_failed;
573 cur = delim;
574 }
575 cur++;
576
577 /* dst ip */
578 if ((delim = strchr(cur, '/')) == NULL)
579 goto parse_failed;
580 *delim = 0;
581 ipv6 = netpoll_parse_ip_addr(cur, &np->remote_ip);
582 if (ipv6 < 0)
583 goto parse_failed;
584 else if (ipversion_set && np->ipv6 != (bool)ipv6)
585 goto parse_failed;
586 else
587 np->ipv6 = (bool)ipv6;
588 cur = delim + 1;
589
590 if (*cur != 0) {
591 /* MAC address */
592 if (!mac_pton(cur, np->remote_mac))
593 goto parse_failed;
594 }
595
596 netpoll_print_options(np);
597
598 return 0;
599
600 parse_failed:
601 np_info(np, "couldn't parse config at '%s'!\n", cur);
602 return -1;
603}
604EXPORT_SYMBOL(netpoll_parse_options);
605
606int __netpoll_setup(struct netpoll *np, struct net_device *ndev)
607{
608 struct netpoll_info *npinfo;
609 const struct net_device_ops *ops;
610 int err;
611
612 np->dev = ndev;
613 strlcpy(np->dev_name, ndev->name, IFNAMSIZ);
614 INIT_WORK(&np->cleanup_work, netpoll_async_cleanup);
615
616 if ((ndev->priv_flags & IFF_DISABLE_NETPOLL) ||
617 !ndev->netdev_ops->ndo_poll_controller) {
618 np_err(np, "%s doesn't support polling, aborting\n",
619 np->dev_name);
620 err = -ENOTSUPP;
621 goto out;
622 }
623
624 if (!ndev->npinfo) {
625 npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL);
626 if (!npinfo) {
627 err = -ENOMEM;
628 goto out;
629 }
630
631 sema_init(&npinfo->dev_lock, 1);
632 skb_queue_head_init(&npinfo->txq);
633 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process);
634
635 refcount_set(&npinfo->refcnt, 1);
636
637 ops = np->dev->netdev_ops;
638 if (ops->ndo_netpoll_setup) {
639 err = ops->ndo_netpoll_setup(ndev, npinfo);
640 if (err)
641 goto free_npinfo;
642 }
643 } else {
644 npinfo = rtnl_dereference(ndev->npinfo);
645 refcount_inc(&npinfo->refcnt);
646 }
647
648 npinfo->netpoll = np;
649
650 /* last thing to do is link it to the net device structure */
651 rcu_assign_pointer(ndev->npinfo, npinfo);
652
653 return 0;
654
655free_npinfo:
656 kfree(npinfo);
657out:
658 return err;
659}
660EXPORT_SYMBOL_GPL(__netpoll_setup);
661
662int netpoll_setup(struct netpoll *np)
663{
664 struct net_device *ndev = NULL;
665 struct in_device *in_dev;
666 int err;
667
668 rtnl_lock();
669 if (np->dev_name[0]) {
670 struct net *net = current->nsproxy->net_ns;
671 ndev = __dev_get_by_name(net, np->dev_name);
672 }
673 if (!ndev) {
674 np_err(np, "%s doesn't exist, aborting\n", np->dev_name);
675 err = -ENODEV;
676 goto unlock;
677 }
678 dev_hold(ndev);
679
680 if (netdev_master_upper_dev_get(ndev)) {
681 np_err(np, "%s is a slave device, aborting\n", np->dev_name);
682 err = -EBUSY;
683 goto put;
684 }
685
686 if (!netif_running(ndev)) {
687 unsigned long atmost, atleast;
688
689 np_info(np, "device %s not up yet, forcing it\n", np->dev_name);
690
691 err = dev_open(ndev);
692
693 if (err) {
694 np_err(np, "failed to open %s\n", ndev->name);
695 goto put;
696 }
697
698 rtnl_unlock();
699 atleast = jiffies + HZ/10;
700 atmost = jiffies + carrier_timeout * HZ;
701 while (!netif_carrier_ok(ndev)) {
702 if (time_after(jiffies, atmost)) {
703 np_notice(np, "timeout waiting for carrier\n");
704 break;
705 }
706 msleep(1);
707 }
708
709 /* If carrier appears to come up instantly, we don't
710 * trust it and pause so that we don't pump all our
711 * queued console messages into the bitbucket.
712 */
713
714 if (time_before(jiffies, atleast)) {
715 np_notice(np, "carrier detect appears untrustworthy, waiting 4 seconds\n");
716 msleep(4000);
717 }
718 rtnl_lock();
719 }
720
721 if (!np->local_ip.ip) {
722 if (!np->ipv6) {
723 in_dev = __in_dev_get_rtnl(ndev);
724
725 if (!in_dev || !in_dev->ifa_list) {
726 np_err(np, "no IP address for %s, aborting\n",
727 np->dev_name);
728 err = -EDESTADDRREQ;
729 goto put;
730 }
731
732 np->local_ip.ip = in_dev->ifa_list->ifa_local;
733 np_info(np, "local IP %pI4\n", &np->local_ip.ip);
734 } else {
735#if IS_ENABLED(CONFIG_IPV6)
736 struct inet6_dev *idev;
737
738 err = -EDESTADDRREQ;
739 idev = __in6_dev_get(ndev);
740 if (idev) {
741 struct inet6_ifaddr *ifp;
742
743 read_lock_bh(&idev->lock);
744 list_for_each_entry(ifp, &idev->addr_list, if_list) {
745 if (ipv6_addr_type(&ifp->addr) & IPV6_ADDR_LINKLOCAL)
746 continue;
747 np->local_ip.in6 = ifp->addr;
748 err = 0;
749 break;
750 }
751 read_unlock_bh(&idev->lock);
752 }
753 if (err) {
754 np_err(np, "no IPv6 address for %s, aborting\n",
755 np->dev_name);
756 goto put;
757 } else
758 np_info(np, "local IPv6 %pI6c\n", &np->local_ip.in6);
759#else
760 np_err(np, "IPv6 is not supported %s, aborting\n",
761 np->dev_name);
762 err = -EINVAL;
763 goto put;
764#endif
765 }
766 }
767
768 /* fill up the skb queue */
769 refill_skbs();
770
771 err = __netpoll_setup(np, ndev);
772 if (err)
773 goto put;
774
775 rtnl_unlock();
776 return 0;
777
778put:
779 dev_put(ndev);
780unlock:
781 rtnl_unlock();
782 return err;
783}
784EXPORT_SYMBOL(netpoll_setup);
785
786static int __init netpoll_init(void)
787{
788 skb_queue_head_init(&skb_pool);
789 return 0;
790}
791core_initcall(netpoll_init);
792
793static void rcu_cleanup_netpoll_info(struct rcu_head *rcu_head)
794{
795 struct netpoll_info *npinfo =
796 container_of(rcu_head, struct netpoll_info, rcu);
797
798 skb_queue_purge(&npinfo->txq);
799
800 /* we can't call cancel_delayed_work_sync here, as we are in softirq */
801 cancel_delayed_work(&npinfo->tx_work);
802
803 /* clean after last, unfinished work */
804 __skb_queue_purge(&npinfo->txq);
805 /* now cancel it again */
806 cancel_delayed_work(&npinfo->tx_work);
807 kfree(npinfo);
808}
809
810void __netpoll_cleanup(struct netpoll *np)
811{
812 struct netpoll_info *npinfo;
813
814 /* rtnl_dereference would be preferable here but
815 * rcu_cleanup_netpoll path can put us in here safely without
816 * holding the rtnl, so plain rcu_dereference it is
817 */
818 npinfo = rtnl_dereference(np->dev->npinfo);
819 if (!npinfo)
820 return;
821
822 synchronize_srcu(&netpoll_srcu);
823
824 if (refcount_dec_and_test(&npinfo->refcnt)) {
825 const struct net_device_ops *ops;
826
827 ops = np->dev->netdev_ops;
828 if (ops->ndo_netpoll_cleanup)
829 ops->ndo_netpoll_cleanup(np->dev);
830
831 RCU_INIT_POINTER(np->dev->npinfo, NULL);
832 call_rcu_bh(&npinfo->rcu, rcu_cleanup_netpoll_info);
833 } else
834 RCU_INIT_POINTER(np->dev->npinfo, NULL);
835}
836EXPORT_SYMBOL_GPL(__netpoll_cleanup);
837
838static void netpoll_async_cleanup(struct work_struct *work)
839{
840 struct netpoll *np = container_of(work, struct netpoll, cleanup_work);
841
842 rtnl_lock();
843 __netpoll_cleanup(np);
844 rtnl_unlock();
845 kfree(np);
846}
847
848void __netpoll_free_async(struct netpoll *np)
849{
850 schedule_work(&np->cleanup_work);
851}
852EXPORT_SYMBOL_GPL(__netpoll_free_async);
853
854void netpoll_cleanup(struct netpoll *np)
855{
856 rtnl_lock();
857 if (!np->dev)
858 goto out;
859 __netpoll_cleanup(np);
860 dev_put(np->dev);
861 np->dev = NULL;
862out:
863 rtnl_unlock();
864}
865EXPORT_SYMBOL(netpoll_cleanup);