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