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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#include <linux/moduleparam.h>
13#include <linux/netdevice.h>
14#include <linux/etherdevice.h>
15#include <linux/string.h>
16#include <linux/if_arp.h>
17#include <linux/inetdevice.h>
18#include <linux/inet.h>
19#include <linux/interrupt.h>
20#include <linux/netpoll.h>
21#include <linux/sched.h>
22#include <linux/delay.h>
23#include <linux/rcupdate.h>
24#include <linux/workqueue.h>
25#include <linux/slab.h>
26#include <net/tcp.h>
27#include <net/udp.h>
28#include <asm/unaligned.h>
29#include <trace/events/napi.h>
30
31/*
32 * We maintain a small pool of fully-sized skbs, to make sure the
33 * message gets out even in extreme OOM situations.
34 */
35
36#define MAX_UDP_CHUNK 1460
37#define MAX_SKBS 32
38
39static struct sk_buff_head skb_pool;
40
41static atomic_t trapped;
42
43#define USEC_PER_POLL 50
44#define NETPOLL_RX_ENABLED 1
45#define NETPOLL_RX_DROP 2
46
47#define MAX_SKB_SIZE \
48 (MAX_UDP_CHUNK + sizeof(struct udphdr) + \
49 sizeof(struct iphdr) + sizeof(struct ethhdr))
50
51static void zap_completion_queue(void);
52static void arp_reply(struct sk_buff *skb);
53
54static unsigned int carrier_timeout = 4;
55module_param(carrier_timeout, uint, 0644);
56
57static void queue_process(struct work_struct *work)
58{
59 struct netpoll_info *npinfo =
60 container_of(work, struct netpoll_info, tx_work.work);
61 struct sk_buff *skb;
62 unsigned long flags;
63
64 while ((skb = skb_dequeue(&npinfo->txq))) {
65 struct net_device *dev = skb->dev;
66 const struct net_device_ops *ops = dev->netdev_ops;
67 struct netdev_queue *txq;
68
69 if (!netif_device_present(dev) || !netif_running(dev)) {
70 __kfree_skb(skb);
71 continue;
72 }
73
74 txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb));
75
76 local_irq_save(flags);
77 __netif_tx_lock(txq, smp_processor_id());
78 if (netif_tx_queue_frozen_or_stopped(txq) ||
79 ops->ndo_start_xmit(skb, dev) != NETDEV_TX_OK) {
80 skb_queue_head(&npinfo->txq, skb);
81 __netif_tx_unlock(txq);
82 local_irq_restore(flags);
83
84 schedule_delayed_work(&npinfo->tx_work, HZ/10);
85 return;
86 }
87 __netif_tx_unlock(txq);
88 local_irq_restore(flags);
89 }
90}
91
92static __sum16 checksum_udp(struct sk_buff *skb, struct udphdr *uh,
93 unsigned short ulen, __be32 saddr, __be32 daddr)
94{
95 __wsum psum;
96
97 if (uh->check == 0 || skb_csum_unnecessary(skb))
98 return 0;
99
100 psum = csum_tcpudp_nofold(saddr, daddr, ulen, IPPROTO_UDP, 0);
101
102 if (skb->ip_summed == CHECKSUM_COMPLETE &&
103 !csum_fold(csum_add(psum, skb->csum)))
104 return 0;
105
106 skb->csum = psum;
107
108 return __skb_checksum_complete(skb);
109}
110
111/*
112 * Check whether delayed processing was scheduled for our NIC. If so,
113 * we attempt to grab the poll lock and use ->poll() to pump the card.
114 * If this fails, either we've recursed in ->poll() or it's already
115 * running on another CPU.
116 *
117 * Note: we don't mask interrupts with this lock because we're using
118 * trylock here and interrupts are already disabled in the softirq
119 * case. Further, we test the poll_owner to avoid recursion on UP
120 * systems where the lock doesn't exist.
121 *
122 * In cases where there is bi-directional communications, reading only
123 * one message at a time can lead to packets being dropped by the
124 * network adapter, forcing superfluous retries and possibly timeouts.
125 * Thus, we set our budget to greater than 1.
126 */
127static int poll_one_napi(struct netpoll_info *npinfo,
128 struct napi_struct *napi, int budget)
129{
130 int work;
131
132 /* net_rx_action's ->poll() invocations and our's are
133 * synchronized by this test which is only made while
134 * holding the napi->poll_lock.
135 */
136 if (!test_bit(NAPI_STATE_SCHED, &napi->state))
137 return budget;
138
139 npinfo->rx_flags |= NETPOLL_RX_DROP;
140 atomic_inc(&trapped);
141 set_bit(NAPI_STATE_NPSVC, &napi->state);
142
143 work = napi->poll(napi, budget);
144 trace_napi_poll(napi);
145
146 clear_bit(NAPI_STATE_NPSVC, &napi->state);
147 atomic_dec(&trapped);
148 npinfo->rx_flags &= ~NETPOLL_RX_DROP;
149
150 return budget - work;
151}
152
153static void poll_napi(struct net_device *dev)
154{
155 struct napi_struct *napi;
156 int budget = 16;
157
158 list_for_each_entry(napi, &dev->napi_list, dev_list) {
159 if (napi->poll_owner != smp_processor_id() &&
160 spin_trylock(&napi->poll_lock)) {
161 budget = poll_one_napi(dev->npinfo, napi, budget);
162 spin_unlock(&napi->poll_lock);
163
164 if (!budget)
165 break;
166 }
167 }
168}
169
170static void service_arp_queue(struct netpoll_info *npi)
171{
172 if (npi) {
173 struct sk_buff *skb;
174
175 while ((skb = skb_dequeue(&npi->arp_tx)))
176 arp_reply(skb);
177 }
178}
179
180static void netpoll_poll_dev(struct net_device *dev)
181{
182 const struct net_device_ops *ops;
183
184 if (!dev || !netif_running(dev))
185 return;
186
187 ops = dev->netdev_ops;
188 if (!ops->ndo_poll_controller)
189 return;
190
191 /* Process pending work on NIC */
192 ops->ndo_poll_controller(dev);
193
194 poll_napi(dev);
195
196 if (dev->priv_flags & IFF_SLAVE) {
197 if (dev->npinfo) {
198 struct net_device *bond_dev = dev->master;
199 struct sk_buff *skb;
200 while ((skb = skb_dequeue(&dev->npinfo->arp_tx))) {
201 skb->dev = bond_dev;
202 skb_queue_tail(&bond_dev->npinfo->arp_tx, skb);
203 }
204 }
205 }
206
207 service_arp_queue(dev->npinfo);
208
209 zap_completion_queue();
210}
211
212static void refill_skbs(void)
213{
214 struct sk_buff *skb;
215 unsigned long flags;
216
217 spin_lock_irqsave(&skb_pool.lock, flags);
218 while (skb_pool.qlen < MAX_SKBS) {
219 skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC);
220 if (!skb)
221 break;
222
223 __skb_queue_tail(&skb_pool, skb);
224 }
225 spin_unlock_irqrestore(&skb_pool.lock, flags);
226}
227
228static void zap_completion_queue(void)
229{
230 unsigned long flags;
231 struct softnet_data *sd = &get_cpu_var(softnet_data);
232
233 if (sd->completion_queue) {
234 struct sk_buff *clist;
235
236 local_irq_save(flags);
237 clist = sd->completion_queue;
238 sd->completion_queue = NULL;
239 local_irq_restore(flags);
240
241 while (clist != NULL) {
242 struct sk_buff *skb = clist;
243 clist = clist->next;
244 if (skb->destructor) {
245 atomic_inc(&skb->users);
246 dev_kfree_skb_any(skb); /* put this one back */
247 } else {
248 __kfree_skb(skb);
249 }
250 }
251 }
252
253 put_cpu_var(softnet_data);
254}
255
256static struct sk_buff *find_skb(struct netpoll *np, int len, int reserve)
257{
258 int count = 0;
259 struct sk_buff *skb;
260
261 zap_completion_queue();
262 refill_skbs();
263repeat:
264
265 skb = alloc_skb(len, GFP_ATOMIC);
266 if (!skb)
267 skb = skb_dequeue(&skb_pool);
268
269 if (!skb) {
270 if (++count < 10) {
271 netpoll_poll_dev(np->dev);
272 goto repeat;
273 }
274 return NULL;
275 }
276
277 atomic_set(&skb->users, 1);
278 skb_reserve(skb, reserve);
279 return skb;
280}
281
282static int netpoll_owner_active(struct net_device *dev)
283{
284 struct napi_struct *napi;
285
286 list_for_each_entry(napi, &dev->napi_list, dev_list) {
287 if (napi->poll_owner == smp_processor_id())
288 return 1;
289 }
290 return 0;
291}
292
293void netpoll_send_skb_on_dev(struct netpoll *np, struct sk_buff *skb,
294 struct net_device *dev)
295{
296 int status = NETDEV_TX_BUSY;
297 unsigned long tries;
298 const struct net_device_ops *ops = dev->netdev_ops;
299 /* It is up to the caller to keep npinfo alive. */
300 struct netpoll_info *npinfo = np->dev->npinfo;
301
302 if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) {
303 __kfree_skb(skb);
304 return;
305 }
306
307 /* don't get messages out of order, and no recursion */
308 if (skb_queue_len(&npinfo->txq) == 0 && !netpoll_owner_active(dev)) {
309 struct netdev_queue *txq;
310 unsigned long flags;
311
312 txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb));
313
314 local_irq_save(flags);
315 /* try until next clock tick */
316 for (tries = jiffies_to_usecs(1)/USEC_PER_POLL;
317 tries > 0; --tries) {
318 if (__netif_tx_trylock(txq)) {
319 if (!netif_tx_queue_stopped(txq)) {
320 status = ops->ndo_start_xmit(skb, dev);
321 if (status == NETDEV_TX_OK)
322 txq_trans_update(txq);
323 }
324 __netif_tx_unlock(txq);
325
326 if (status == NETDEV_TX_OK)
327 break;
328
329 }
330
331 /* tickle device maybe there is some cleanup */
332 netpoll_poll_dev(np->dev);
333
334 udelay(USEC_PER_POLL);
335 }
336
337 WARN_ONCE(!irqs_disabled(),
338 "netpoll_send_skb(): %s enabled interrupts in poll (%pF)\n",
339 dev->name, ops->ndo_start_xmit);
340
341 local_irq_restore(flags);
342 }
343
344 if (status != NETDEV_TX_OK) {
345 skb_queue_tail(&npinfo->txq, skb);
346 schedule_delayed_work(&npinfo->tx_work,0);
347 }
348}
349EXPORT_SYMBOL(netpoll_send_skb_on_dev);
350
351void netpoll_send_udp(struct netpoll *np, const char *msg, int len)
352{
353 int total_len, eth_len, ip_len, udp_len;
354 struct sk_buff *skb;
355 struct udphdr *udph;
356 struct iphdr *iph;
357 struct ethhdr *eth;
358
359 udp_len = len + sizeof(*udph);
360 ip_len = eth_len = udp_len + sizeof(*iph);
361 total_len = eth_len + ETH_HLEN + NET_IP_ALIGN;
362
363 skb = find_skb(np, total_len, total_len - len);
364 if (!skb)
365 return;
366
367 skb_copy_to_linear_data(skb, msg, len);
368 skb->len += len;
369
370 skb_push(skb, sizeof(*udph));
371 skb_reset_transport_header(skb);
372 udph = udp_hdr(skb);
373 udph->source = htons(np->local_port);
374 udph->dest = htons(np->remote_port);
375 udph->len = htons(udp_len);
376 udph->check = 0;
377 udph->check = csum_tcpudp_magic(np->local_ip,
378 np->remote_ip,
379 udp_len, IPPROTO_UDP,
380 csum_partial(udph, udp_len, 0));
381 if (udph->check == 0)
382 udph->check = CSUM_MANGLED_0;
383
384 skb_push(skb, sizeof(*iph));
385 skb_reset_network_header(skb);
386 iph = ip_hdr(skb);
387
388 /* iph->version = 4; iph->ihl = 5; */
389 put_unaligned(0x45, (unsigned char *)iph);
390 iph->tos = 0;
391 put_unaligned(htons(ip_len), &(iph->tot_len));
392 iph->id = 0;
393 iph->frag_off = 0;
394 iph->ttl = 64;
395 iph->protocol = IPPROTO_UDP;
396 iph->check = 0;
397 put_unaligned(np->local_ip, &(iph->saddr));
398 put_unaligned(np->remote_ip, &(iph->daddr));
399 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl);
400
401 eth = (struct ethhdr *) skb_push(skb, ETH_HLEN);
402 skb_reset_mac_header(skb);
403 skb->protocol = eth->h_proto = htons(ETH_P_IP);
404 memcpy(eth->h_source, np->dev->dev_addr, ETH_ALEN);
405 memcpy(eth->h_dest, np->remote_mac, ETH_ALEN);
406
407 skb->dev = np->dev;
408
409 netpoll_send_skb(np, skb);
410}
411EXPORT_SYMBOL(netpoll_send_udp);
412
413static void arp_reply(struct sk_buff *skb)
414{
415 struct netpoll_info *npinfo = skb->dev->npinfo;
416 struct arphdr *arp;
417 unsigned char *arp_ptr;
418 int size, type = ARPOP_REPLY, ptype = ETH_P_ARP;
419 __be32 sip, tip;
420 unsigned char *sha;
421 struct sk_buff *send_skb;
422 struct netpoll *np, *tmp;
423 unsigned long flags;
424 int hits = 0;
425
426 if (list_empty(&npinfo->rx_np))
427 return;
428
429 /* Before checking the packet, we do some early
430 inspection whether this is interesting at all */
431 spin_lock_irqsave(&npinfo->rx_lock, flags);
432 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) {
433 if (np->dev == skb->dev)
434 hits++;
435 }
436 spin_unlock_irqrestore(&npinfo->rx_lock, flags);
437
438 /* No netpoll struct is using this dev */
439 if (!hits)
440 return;
441
442 /* No arp on this interface */
443 if (skb->dev->flags & IFF_NOARP)
444 return;
445
446 if (!pskb_may_pull(skb, arp_hdr_len(skb->dev)))
447 return;
448
449 skb_reset_network_header(skb);
450 skb_reset_transport_header(skb);
451 arp = arp_hdr(skb);
452
453 if ((arp->ar_hrd != htons(ARPHRD_ETHER) &&
454 arp->ar_hrd != htons(ARPHRD_IEEE802)) ||
455 arp->ar_pro != htons(ETH_P_IP) ||
456 arp->ar_op != htons(ARPOP_REQUEST))
457 return;
458
459 arp_ptr = (unsigned char *)(arp+1);
460 /* save the location of the src hw addr */
461 sha = arp_ptr;
462 arp_ptr += skb->dev->addr_len;
463 memcpy(&sip, arp_ptr, 4);
464 arp_ptr += 4;
465 /* If we actually cared about dst hw addr,
466 it would get copied here */
467 arp_ptr += skb->dev->addr_len;
468 memcpy(&tip, arp_ptr, 4);
469
470 /* Should we ignore arp? */
471 if (ipv4_is_loopback(tip) || ipv4_is_multicast(tip))
472 return;
473
474 size = arp_hdr_len(skb->dev);
475
476 spin_lock_irqsave(&npinfo->rx_lock, flags);
477 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) {
478 if (tip != np->local_ip)
479 continue;
480
481 send_skb = find_skb(np, size + LL_ALLOCATED_SPACE(np->dev),
482 LL_RESERVED_SPACE(np->dev));
483 if (!send_skb)
484 continue;
485
486 skb_reset_network_header(send_skb);
487 arp = (struct arphdr *) skb_put(send_skb, size);
488 send_skb->dev = skb->dev;
489 send_skb->protocol = htons(ETH_P_ARP);
490
491 /* Fill the device header for the ARP frame */
492 if (dev_hard_header(send_skb, skb->dev, ptype,
493 sha, np->dev->dev_addr,
494 send_skb->len) < 0) {
495 kfree_skb(send_skb);
496 continue;
497 }
498
499 /*
500 * Fill out the arp protocol part.
501 *
502 * we only support ethernet device type,
503 * which (according to RFC 1390) should
504 * always equal 1 (Ethernet).
505 */
506
507 arp->ar_hrd = htons(np->dev->type);
508 arp->ar_pro = htons(ETH_P_IP);
509 arp->ar_hln = np->dev->addr_len;
510 arp->ar_pln = 4;
511 arp->ar_op = htons(type);
512
513 arp_ptr = (unsigned char *)(arp + 1);
514 memcpy(arp_ptr, np->dev->dev_addr, np->dev->addr_len);
515 arp_ptr += np->dev->addr_len;
516 memcpy(arp_ptr, &tip, 4);
517 arp_ptr += 4;
518 memcpy(arp_ptr, sha, np->dev->addr_len);
519 arp_ptr += np->dev->addr_len;
520 memcpy(arp_ptr, &sip, 4);
521
522 netpoll_send_skb(np, send_skb);
523
524 /* If there are several rx_hooks for the same address,
525 we're fine by sending a single reply */
526 break;
527 }
528 spin_unlock_irqrestore(&npinfo->rx_lock, flags);
529}
530
531int __netpoll_rx(struct sk_buff *skb)
532{
533 int proto, len, ulen;
534 int hits = 0;
535 const struct iphdr *iph;
536 struct udphdr *uh;
537 struct netpoll_info *npinfo = skb->dev->npinfo;
538 struct netpoll *np, *tmp;
539
540 if (list_empty(&npinfo->rx_np))
541 goto out;
542
543 if (skb->dev->type != ARPHRD_ETHER)
544 goto out;
545
546 /* check if netpoll clients need ARP */
547 if (skb->protocol == htons(ETH_P_ARP) &&
548 atomic_read(&trapped)) {
549 skb_queue_tail(&npinfo->arp_tx, skb);
550 return 1;
551 }
552
553 proto = ntohs(eth_hdr(skb)->h_proto);
554 if (proto != ETH_P_IP)
555 goto out;
556 if (skb->pkt_type == PACKET_OTHERHOST)
557 goto out;
558 if (skb_shared(skb))
559 goto out;
560
561 if (!pskb_may_pull(skb, sizeof(struct iphdr)))
562 goto out;
563 iph = (struct iphdr *)skb->data;
564 if (iph->ihl < 5 || iph->version != 4)
565 goto out;
566 if (!pskb_may_pull(skb, iph->ihl*4))
567 goto out;
568 iph = (struct iphdr *)skb->data;
569 if (ip_fast_csum((u8 *)iph, iph->ihl) != 0)
570 goto out;
571
572 len = ntohs(iph->tot_len);
573 if (skb->len < len || len < iph->ihl*4)
574 goto out;
575
576 /*
577 * Our transport medium may have padded the buffer out.
578 * Now We trim to the true length of the frame.
579 */
580 if (pskb_trim_rcsum(skb, len))
581 goto out;
582
583 iph = (struct iphdr *)skb->data;
584 if (iph->protocol != IPPROTO_UDP)
585 goto out;
586
587 len -= iph->ihl*4;
588 uh = (struct udphdr *)(((char *)iph) + iph->ihl*4);
589 ulen = ntohs(uh->len);
590
591 if (ulen != len)
592 goto out;
593 if (checksum_udp(skb, uh, ulen, iph->saddr, iph->daddr))
594 goto out;
595
596 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) {
597 if (np->local_ip && np->local_ip != iph->daddr)
598 continue;
599 if (np->remote_ip && np->remote_ip != iph->saddr)
600 continue;
601 if (np->local_port && np->local_port != ntohs(uh->dest))
602 continue;
603
604 np->rx_hook(np, ntohs(uh->source),
605 (char *)(uh+1),
606 ulen - sizeof(struct udphdr));
607 hits++;
608 }
609
610 if (!hits)
611 goto out;
612
613 kfree_skb(skb);
614 return 1;
615
616out:
617 if (atomic_read(&trapped)) {
618 kfree_skb(skb);
619 return 1;
620 }
621
622 return 0;
623}
624
625void netpoll_print_options(struct netpoll *np)
626{
627 printk(KERN_INFO "%s: local port %d\n",
628 np->name, np->local_port);
629 printk(KERN_INFO "%s: local IP %pI4\n",
630 np->name, &np->local_ip);
631 printk(KERN_INFO "%s: interface '%s'\n",
632 np->name, np->dev_name);
633 printk(KERN_INFO "%s: remote port %d\n",
634 np->name, np->remote_port);
635 printk(KERN_INFO "%s: remote IP %pI4\n",
636 np->name, &np->remote_ip);
637 printk(KERN_INFO "%s: remote ethernet address %pM\n",
638 np->name, np->remote_mac);
639}
640EXPORT_SYMBOL(netpoll_print_options);
641
642int netpoll_parse_options(struct netpoll *np, char *opt)
643{
644 char *cur=opt, *delim;
645
646 if (*cur != '@') {
647 if ((delim = strchr(cur, '@')) == NULL)
648 goto parse_failed;
649 *delim = 0;
650 np->local_port = simple_strtol(cur, NULL, 10);
651 cur = delim;
652 }
653 cur++;
654
655 if (*cur != '/') {
656 if ((delim = strchr(cur, '/')) == NULL)
657 goto parse_failed;
658 *delim = 0;
659 np->local_ip = in_aton(cur);
660 cur = delim;
661 }
662 cur++;
663
664 if (*cur != ',') {
665 /* parse out dev name */
666 if ((delim = strchr(cur, ',')) == NULL)
667 goto parse_failed;
668 *delim = 0;
669 strlcpy(np->dev_name, cur, sizeof(np->dev_name));
670 cur = delim;
671 }
672 cur++;
673
674 if (*cur != '@') {
675 /* dst port */
676 if ((delim = strchr(cur, '@')) == NULL)
677 goto parse_failed;
678 *delim = 0;
679 if (*cur == ' ' || *cur == '\t')
680 printk(KERN_INFO "%s: warning: whitespace"
681 "is not allowed\n", np->name);
682 np->remote_port = simple_strtol(cur, NULL, 10);
683 cur = delim;
684 }
685 cur++;
686
687 /* dst ip */
688 if ((delim = strchr(cur, '/')) == NULL)
689 goto parse_failed;
690 *delim = 0;
691 np->remote_ip = in_aton(cur);
692 cur = delim + 1;
693
694 if (*cur != 0) {
695 /* MAC address */
696 if (!mac_pton(cur, np->remote_mac))
697 goto parse_failed;
698 }
699
700 netpoll_print_options(np);
701
702 return 0;
703
704 parse_failed:
705 printk(KERN_INFO "%s: couldn't parse config at '%s'!\n",
706 np->name, cur);
707 return -1;
708}
709EXPORT_SYMBOL(netpoll_parse_options);
710
711int __netpoll_setup(struct netpoll *np)
712{
713 struct net_device *ndev = np->dev;
714 struct netpoll_info *npinfo;
715 const struct net_device_ops *ops;
716 unsigned long flags;
717 int err;
718
719 if ((ndev->priv_flags & IFF_DISABLE_NETPOLL) ||
720 !ndev->netdev_ops->ndo_poll_controller) {
721 printk(KERN_ERR "%s: %s doesn't support polling, aborting.\n",
722 np->name, np->dev_name);
723 err = -ENOTSUPP;
724 goto out;
725 }
726
727 if (!ndev->npinfo) {
728 npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL);
729 if (!npinfo) {
730 err = -ENOMEM;
731 goto out;
732 }
733
734 npinfo->rx_flags = 0;
735 INIT_LIST_HEAD(&npinfo->rx_np);
736
737 spin_lock_init(&npinfo->rx_lock);
738 skb_queue_head_init(&npinfo->arp_tx);
739 skb_queue_head_init(&npinfo->txq);
740 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process);
741
742 atomic_set(&npinfo->refcnt, 1);
743
744 ops = np->dev->netdev_ops;
745 if (ops->ndo_netpoll_setup) {
746 err = ops->ndo_netpoll_setup(ndev, npinfo);
747 if (err)
748 goto free_npinfo;
749 }
750 } else {
751 npinfo = ndev->npinfo;
752 atomic_inc(&npinfo->refcnt);
753 }
754
755 npinfo->netpoll = np;
756
757 if (np->rx_hook) {
758 spin_lock_irqsave(&npinfo->rx_lock, flags);
759 npinfo->rx_flags |= NETPOLL_RX_ENABLED;
760 list_add_tail(&np->rx, &npinfo->rx_np);
761 spin_unlock_irqrestore(&npinfo->rx_lock, flags);
762 }
763
764 /* last thing to do is link it to the net device structure */
765 rcu_assign_pointer(ndev->npinfo, npinfo);
766
767 return 0;
768
769free_npinfo:
770 kfree(npinfo);
771out:
772 return err;
773}
774EXPORT_SYMBOL_GPL(__netpoll_setup);
775
776int netpoll_setup(struct netpoll *np)
777{
778 struct net_device *ndev = NULL;
779 struct in_device *in_dev;
780 int err;
781
782 if (np->dev_name)
783 ndev = dev_get_by_name(&init_net, np->dev_name);
784 if (!ndev) {
785 printk(KERN_ERR "%s: %s doesn't exist, aborting.\n",
786 np->name, np->dev_name);
787 return -ENODEV;
788 }
789
790 if (ndev->master) {
791 printk(KERN_ERR "%s: %s is a slave device, aborting.\n",
792 np->name, np->dev_name);
793 err = -EBUSY;
794 goto put;
795 }
796
797 if (!netif_running(ndev)) {
798 unsigned long atmost, atleast;
799
800 printk(KERN_INFO "%s: device %s not up yet, forcing it\n",
801 np->name, np->dev_name);
802
803 rtnl_lock();
804 err = dev_open(ndev);
805 rtnl_unlock();
806
807 if (err) {
808 printk(KERN_ERR "%s: failed to open %s\n",
809 np->name, ndev->name);
810 goto put;
811 }
812
813 atleast = jiffies + HZ/10;
814 atmost = jiffies + carrier_timeout * HZ;
815 while (!netif_carrier_ok(ndev)) {
816 if (time_after(jiffies, atmost)) {
817 printk(KERN_NOTICE
818 "%s: timeout waiting for carrier\n",
819 np->name);
820 break;
821 }
822 msleep(1);
823 }
824
825 /* If carrier appears to come up instantly, we don't
826 * trust it and pause so that we don't pump all our
827 * queued console messages into the bitbucket.
828 */
829
830 if (time_before(jiffies, atleast)) {
831 printk(KERN_NOTICE "%s: carrier detect appears"
832 " untrustworthy, waiting 4 seconds\n",
833 np->name);
834 msleep(4000);
835 }
836 }
837
838 if (!np->local_ip) {
839 rcu_read_lock();
840 in_dev = __in_dev_get_rcu(ndev);
841
842 if (!in_dev || !in_dev->ifa_list) {
843 rcu_read_unlock();
844 printk(KERN_ERR "%s: no IP address for %s, aborting\n",
845 np->name, np->dev_name);
846 err = -EDESTADDRREQ;
847 goto put;
848 }
849
850 np->local_ip = in_dev->ifa_list->ifa_local;
851 rcu_read_unlock();
852 printk(KERN_INFO "%s: local IP %pI4\n", np->name, &np->local_ip);
853 }
854
855 np->dev = ndev;
856
857 /* fill up the skb queue */
858 refill_skbs();
859
860 rtnl_lock();
861 err = __netpoll_setup(np);
862 rtnl_unlock();
863
864 if (err)
865 goto put;
866
867 return 0;
868
869put:
870 dev_put(ndev);
871 return err;
872}
873EXPORT_SYMBOL(netpoll_setup);
874
875static int __init netpoll_init(void)
876{
877 skb_queue_head_init(&skb_pool);
878 return 0;
879}
880core_initcall(netpoll_init);
881
882void __netpoll_cleanup(struct netpoll *np)
883{
884 struct netpoll_info *npinfo;
885 unsigned long flags;
886
887 npinfo = np->dev->npinfo;
888 if (!npinfo)
889 return;
890
891 if (!list_empty(&npinfo->rx_np)) {
892 spin_lock_irqsave(&npinfo->rx_lock, flags);
893 list_del(&np->rx);
894 if (list_empty(&npinfo->rx_np))
895 npinfo->rx_flags &= ~NETPOLL_RX_ENABLED;
896 spin_unlock_irqrestore(&npinfo->rx_lock, flags);
897 }
898
899 if (atomic_dec_and_test(&npinfo->refcnt)) {
900 const struct net_device_ops *ops;
901
902 ops = np->dev->netdev_ops;
903 if (ops->ndo_netpoll_cleanup)
904 ops->ndo_netpoll_cleanup(np->dev);
905
906 rcu_assign_pointer(np->dev->npinfo, NULL);
907
908 /* avoid racing with NAPI reading npinfo */
909 synchronize_rcu_bh();
910
911 skb_queue_purge(&npinfo->arp_tx);
912 skb_queue_purge(&npinfo->txq);
913 cancel_delayed_work_sync(&npinfo->tx_work);
914
915 /* clean after last, unfinished work */
916 __skb_queue_purge(&npinfo->txq);
917 kfree(npinfo);
918 }
919}
920EXPORT_SYMBOL_GPL(__netpoll_cleanup);
921
922void netpoll_cleanup(struct netpoll *np)
923{
924 if (!np->dev)
925 return;
926
927 rtnl_lock();
928 __netpoll_cleanup(np);
929 rtnl_unlock();
930
931 dev_put(np->dev);
932 np->dev = NULL;
933}
934EXPORT_SYMBOL(netpoll_cleanup);
935
936int netpoll_trap(void)
937{
938 return atomic_read(&trapped);
939}
940EXPORT_SYMBOL(netpoll_trap);
941
942void netpoll_set_trap(int trap)
943{
944 if (trap)
945 atomic_inc(&trapped);
946 else
947 atomic_dec(&trapped);
948}
949EXPORT_SYMBOL(netpoll_set_trap);
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);