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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#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);