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 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 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);