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/netdevice.h>
13 #include <linux/etherdevice.h>
14 #include <linux/string.h>
15 #include <linux/if_arp.h>
16 #include <linux/inetdevice.h>
17 #include <linux/inet.h>
18 #include <linux/interrupt.h>
19 #include <linux/netpoll.h>
20 #include <linux/sched.h>
21 #include <linux/delay.h>
22 #include <linux/rcupdate.h>
23 #include <linux/workqueue.h>
24 #include <net/tcp.h>
25 #include <net/udp.h>
26 #include <asm/unaligned.h>
27
28 /*
29 * We maintain a small pool of fully-sized skbs, to make sure the
30 * message gets out even in extreme OOM situations.
31 */
32
33 #define MAX_UDP_CHUNK 1460
34 #define MAX_SKBS 32
35 #define MAX_QUEUE_DEPTH (MAX_SKBS / 2)
36
37 static struct sk_buff_head skb_pool;
38
39 static atomic_t trapped;
40
41 #define USEC_PER_POLL 50
42 #define NETPOLL_RX_ENABLED 1
43 #define NETPOLL_RX_DROP 2
44
45 #define MAX_SKB_SIZE \
46 (MAX_UDP_CHUNK + sizeof(struct udphdr) + \
47 sizeof(struct iphdr) + sizeof(struct ethhdr))
48
49 static void zap_completion_queue(void);
50 static void arp_reply(struct sk_buff *skb);
51
52 static void queue_process(struct work_struct *work)
53 {
54 struct netpoll_info *npinfo =
55 container_of(work, struct netpoll_info, tx_work.work);
56 struct sk_buff *skb;
57 unsigned long flags;
58
59 while ((skb = skb_dequeue(&npinfo->txq))) {
60 struct net_device *dev = skb->dev;
61
62 if (!netif_device_present(dev) || !netif_running(dev)) {
63 __kfree_skb(skb);
64 continue;
65 }
66
67 local_irq_save_nort(flags);
68 netif_tx_lock(dev);
69 if ((netif_queue_stopped(dev) ||
70 netif_subqueue_stopped(dev, skb)) ||
71 dev->hard_start_xmit(skb, dev) != NETDEV_TX_OK) {
72 skb_queue_head(&npinfo->txq, skb);
73 netif_tx_unlock(dev);
74 local_irq_restore_nort(flags);
75
76 schedule_delayed_work(&npinfo->tx_work, HZ/10);
77 return;
78 }
79 netif_tx_unlock(dev);
80 local_irq_restore_nort(flags);
81 }
82 }
83
84 static __sum16 checksum_udp(struct sk_buff *skb, struct udphdr *uh,
85 unsigned short ulen, __be32 saddr, __be32 daddr)
86 {
87 __wsum psum;
88
89 if (uh->check == 0 || skb_csum_unnecessary(skb))
90 return 0;
91
92 psum = csum_tcpudp_nofold(saddr, daddr, ulen, IPPROTO_UDP, 0);
93
94 if (skb->ip_summed == CHECKSUM_COMPLETE &&
95 !csum_fold(csum_add(psum, skb->csum)))
96 return 0;
97
98 skb->csum = psum;
99
100 return __skb_checksum_complete(skb);
101 }
102
103 /*
104 * Check whether delayed processing was scheduled for our NIC. If so,
105 * we attempt to grab the poll lock and use ->poll() to pump the card.
106 * If this fails, either we've recursed in ->poll() or it's already
107 * running on another CPU.
108 *
109 * Note: we don't mask interrupts with this lock because we're using
110 * trylock here and interrupts are already disabled in the softirq
111 * case. Further, we test the poll_owner to avoid recursion on UP
112 * systems where the lock doesn't exist.
113 *
114 * In cases where there is bi-directional communications, reading only
115 * one message at a time can lead to packets being dropped by the
116 * network adapter, forcing superfluous retries and possibly timeouts.
117 * Thus, we set our budget to greater than 1.
118 */
119 static int poll_one_napi(struct netpoll_info *npinfo,
120 struct napi_struct *napi, int budget)
121 {
122 int work;
123
124 /* net_rx_action's ->poll() invocations and our's are
125 * synchronized by this test which is only made while
126 * holding the napi->poll_lock.
127 */
128 if (!test_bit(NAPI_STATE_SCHED, &napi->state))
129 return budget;
130
131 npinfo->rx_flags |= NETPOLL_RX_DROP;
132 atomic_inc(&trapped);
133
134 work = napi->poll(napi, budget);
135
136 atomic_dec(&trapped);
137 npinfo->rx_flags &= ~NETPOLL_RX_DROP;
138
139 return budget - work;
140 }
141
142 static void poll_napi(struct net_device *dev)
143 {
144 struct napi_struct *napi;
145 int budget = 16;
146
147 list_for_each_entry(napi, &dev->napi_list, dev_list) {
148 if (napi->poll_owner != raw_smp_processor_id() &&
149 spin_trylock(&napi->poll_lock)) {
150 budget = poll_one_napi(dev->npinfo, napi, budget);
151 spin_unlock(&napi->poll_lock);
152
153 if (!budget)
154 break;
155 }
156 }
157 }
158
159 static void service_arp_queue(struct netpoll_info *npi)
160 {
161 if (npi) {
162 struct sk_buff *skb;
163
164 while ((skb = skb_dequeue(&npi->arp_tx)))
165 arp_reply(skb);
166 }
167 }
168
169 void netpoll_poll(struct netpoll *np)
170 {
171 struct net_device *dev = np->dev;
172
173 if (!dev || !netif_running(dev) || !dev->poll_controller)
174 return;
175
176 /* Process pending work on NIC */
177 dev->poll_controller(dev);
178
179 poll_napi(dev);
180
181 service_arp_queue(dev->npinfo);
182
183 zap_completion_queue();
184 }
185
186 static void refill_skbs(void)
187 {
188 struct sk_buff *skb;
189 unsigned long flags;
190
191 spin_lock_irqsave(&skb_pool.lock, flags);
192 while (skb_pool.qlen < MAX_SKBS) {
193 skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC);
194 if (!skb)
195 break;
196
197 __skb_queue_tail(&skb_pool, skb);
198 }
199 spin_unlock_irqrestore(&skb_pool.lock, flags);
200 }
201
202 static void zap_completion_queue(void)
203 {
204 struct softnet_data *sd = &get_cpu_var(softnet_data);
205 struct sk_buff *clist = NULL;
206 unsigned long flags;
207
208 if (sd->completion_queue) {
209
210 local_irq_save(flags);
211 clist = sd->completion_queue;
212 sd->completion_queue = NULL;
213 local_irq_restore(flags);
214 }
215
216
217 /*
218 * Took the list private, can drop our softnet
219 * reference:
220 */
221 put_cpu_var(softnet_data);
222
223 while (clist != NULL) {
224 struct sk_buff *skb = clist;
225 clist = clist->next;
226 if (skb->destructor) {
227 atomic_inc(&skb->users);
228 dev_kfree_skb_any(skb); /* put this one back */
229 } else {
230 __kfree_skb(skb);
231 }
232 }
233 }
234
235 static struct sk_buff *find_skb(struct netpoll *np, int len, int reserve)
236 {
237 int count = 0;
238 struct sk_buff *skb;
239
240 #ifdef CONFIG_PREEMPT_RT
241 /*
242 * On -rt skb_pool.lock is schedulable, so if we are
243 * in an atomic context we just try to dequeue from the
244 * pool and fail if we cannot get one.
245 */
246 if (in_atomic() || irqs_disabled())
247 goto pick_atomic;
248 #endif
249 zap_completion_queue();
250 refill_skbs();
251 repeat:
252
253 skb = alloc_skb(len, GFP_ATOMIC);
254 if (!skb) {
255 #ifdef CONFIG_PREEMPT_RT
256 pick_atomic:
257 #endif
258 skb = skb_dequeue(&skb_pool);
259 }
260
261 if (!skb) {
262 if (++count < 10) {
263 netpoll_poll(np);
264 goto repeat;
265 }
266 return NULL;
267 }
268
269 atomic_set(&skb->users, 1);
270 skb_reserve(skb, reserve);
271 return skb;
272 }
273
274 static int netpoll_owner_active(struct net_device *dev)
275 {
276 struct napi_struct *napi;
277
278 list_for_each_entry(napi, &dev->napi_list, dev_list) {
279 if (napi->poll_owner == raw_smp_processor_id())
280 return 1;
281 }
282 return 0;
283 }
284
285 static void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
286 {
287 int status = NETDEV_TX_BUSY;
288 unsigned long tries;
289 struct net_device *dev = np->dev;
290 struct netpoll_info *npinfo = np->dev->npinfo;
291
292 if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) {
293 __kfree_skb(skb);
294 return;
295 }
296
297 /* don't get messages out of order, and no recursion */
298 if (skb_queue_len(&npinfo->txq) == 0 && !netpoll_owner_active(dev)) {
299 unsigned long flags;
300
301 local_irq_save_nort(flags);
302 /* try until next clock tick */
303 for (tries = jiffies_to_usecs(1)/USEC_PER_POLL;
304 tries > 0; --tries) {
305 if (netif_tx_trylock(dev)) {
306 if (!netif_queue_stopped(dev) &&
307 !netif_subqueue_stopped(dev, skb))
308 status = dev->hard_start_xmit(skb, dev);
309 netif_tx_unlock(dev);
310
311 if (status == NETDEV_TX_OK)
312 break;
313
314 }
315
316 /* tickle device maybe there is some cleanup */
317 netpoll_poll(np);
318
319 udelay(USEC_PER_POLL);
320 }
321 local_irq_restore_nort(flags);
322 }
323
324 if (status != NETDEV_TX_OK) {
325 skb_queue_tail(&npinfo->txq, skb);
326 schedule_delayed_work(&npinfo->tx_work,0);
327 }
328 }
329
330 void netpoll_send_udp(struct netpoll *np, const char *msg, int len)
331 {
332 int total_len, eth_len, ip_len, udp_len;
333 struct sk_buff *skb;
334 struct udphdr *udph;
335 struct iphdr *iph;
336 struct ethhdr *eth;
337
338 udp_len = len + sizeof(*udph);
339 ip_len = eth_len = udp_len + sizeof(*iph);
340 total_len = eth_len + ETH_HLEN + NET_IP_ALIGN;
341
342 skb = find_skb(np, total_len, total_len - len);
343 if (!skb)
344 return;
345
346 skb_copy_to_linear_data(skb, msg, len);
347 skb->len += len;
348
349 skb_push(skb, sizeof(*udph));
350 skb_reset_transport_header(skb);
351 udph = udp_hdr(skb);
352 udph->source = htons(np->local_port);
353 udph->dest = htons(np->remote_port);
354 udph->len = htons(udp_len);
355 udph->check = 0;
356 udph->check = csum_tcpudp_magic(htonl(np->local_ip),
357 htonl(np->remote_ip),
358 udp_len, IPPROTO_UDP,
359 csum_partial((unsigned char *)udph, udp_len, 0));
360 if (udph->check == 0)
361 udph->check = CSUM_MANGLED_0;
362
363 skb_push(skb, sizeof(*iph));
364 skb_reset_network_header(skb);
365 iph = ip_hdr(skb);
366
367 /* iph->version = 4; iph->ihl = 5; */
368 put_unaligned(0x45, (unsigned char *)iph);
369 iph->tos = 0;
370 put_unaligned(htons(ip_len), &(iph->tot_len));
371 iph->id = 0;
372 iph->frag_off = 0;
373 iph->ttl = 64;
374 iph->protocol = IPPROTO_UDP;
375 iph->check = 0;
376 put_unaligned(htonl(np->local_ip), &(iph->saddr));
377 put_unaligned(htonl(np->remote_ip), &(iph->daddr));
378 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl);
379
380 eth = (struct ethhdr *) skb_push(skb, ETH_HLEN);
381 skb_reset_mac_header(skb);
382 skb->protocol = eth->h_proto = htons(ETH_P_IP);
383 memcpy(eth->h_source, np->dev->dev_addr, ETH_ALEN);
384 memcpy(eth->h_dest, np->remote_mac, ETH_ALEN);
385
386 skb->dev = np->dev;
387
388 netpoll_send_skb(np, skb);
389 }
390
391 static void arp_reply(struct sk_buff *skb)
392 {
393 struct netpoll_info *npinfo = skb->dev->npinfo;
394 struct arphdr *arp;
395 unsigned char *arp_ptr;
396 int size, type = ARPOP_REPLY, ptype = ETH_P_ARP;
397 __be32 sip, tip;
398 unsigned char *sha;
399 struct sk_buff *send_skb;
400 struct netpoll *np = NULL;
401
402 if (npinfo->rx_np && npinfo->rx_np->dev == skb->dev)
403 np = npinfo->rx_np;
404 if (!np)
405 return;
406
407 /* No arp on this interface */
408 if (skb->dev->flags & IFF_NOARP)
409 return;
410
411 if (!pskb_may_pull(skb, (sizeof(struct arphdr) +
412 (2 * skb->dev->addr_len) +
413 (2 * sizeof(u32)))))
414 return;
415
416 skb_reset_network_header(skb);
417 skb_reset_transport_header(skb);
418 arp = arp_hdr(skb);
419
420 if ((arp->ar_hrd != htons(ARPHRD_ETHER) &&
421 arp->ar_hrd != htons(ARPHRD_IEEE802)) ||
422 arp->ar_pro != htons(ETH_P_IP) ||
423 arp->ar_op != htons(ARPOP_REQUEST))
424 return;
425
426 arp_ptr = (unsigned char *)(arp+1);
427 /* save the location of the src hw addr */
428 sha = arp_ptr;
429 arp_ptr += skb->dev->addr_len;
430 memcpy(&sip, arp_ptr, 4);
431 arp_ptr += 4;
432 /* if we actually cared about dst hw addr, it would get copied here */
433 arp_ptr += skb->dev->addr_len;
434 memcpy(&tip, arp_ptr, 4);
435
436 /* Should we ignore arp? */
437 if (tip != htonl(np->local_ip) ||
438 ipv4_is_loopback(tip) || ipv4_is_multicast(tip))
439 return;
440
441 size = sizeof(struct arphdr) + 2 * (skb->dev->addr_len + 4);
442 send_skb = find_skb(np, size + LL_RESERVED_SPACE(np->dev),
443 LL_RESERVED_SPACE(np->dev));
444
445 if (!send_skb)
446 return;
447
448 skb_reset_network_header(send_skb);
449 arp = (struct arphdr *) skb_put(send_skb, size);
450 send_skb->dev = skb->dev;
451 send_skb->protocol = htons(ETH_P_ARP);
452
453 /* Fill the device header for the ARP frame */
454 if (dev_hard_header(send_skb, skb->dev, ptype,
455 sha, np->dev->dev_addr,
456 send_skb->len) < 0) {
457 kfree_skb(send_skb);
458 return;
459 }
460
461 /*
462 * Fill out the arp protocol part.
463 *
464 * we only support ethernet device type,
465 * which (according to RFC 1390) should always equal 1 (Ethernet).
466 */
467
468 arp->ar_hrd = htons(np->dev->type);
469 arp->ar_pro = htons(ETH_P_IP);
470 arp->ar_hln = np->dev->addr_len;
471 arp->ar_pln = 4;
472 arp->ar_op = htons(type);
473
474 arp_ptr=(unsigned char *)(arp + 1);
475 memcpy(arp_ptr, np->dev->dev_addr, np->dev->addr_len);
476 arp_ptr += np->dev->addr_len;
477 memcpy(arp_ptr, &tip, 4);
478 arp_ptr += 4;
479 memcpy(arp_ptr, sha, np->dev->addr_len);
480 arp_ptr += np->dev->addr_len;
481 memcpy(arp_ptr, &sip, 4);
482
483 netpoll_send_skb(np, send_skb);
484 }
485
486 int __netpoll_rx(struct sk_buff *skb)
487 {
488 int proto, len, ulen;
489 struct iphdr *iph;
490 struct udphdr *uh;
491 struct netpoll_info *npi = skb->dev->npinfo;
492 struct netpoll *np = npi->rx_np;
493
494 if (!np)
495 goto out;
496 if (skb->dev->type != ARPHRD_ETHER)
497 goto out;
498
499 /* check if netpoll clients need ARP */
500 if (skb->protocol == htons(ETH_P_ARP) &&
501 atomic_read(&trapped)) {
502 skb_queue_tail(&npi->arp_tx, skb);
503 return 1;
504 }
505
506 proto = ntohs(eth_hdr(skb)->h_proto);
507 if (proto != ETH_P_IP)
508 goto out;
509 if (skb->pkt_type == PACKET_OTHERHOST)
510 goto out;
511 if (skb_shared(skb))
512 goto out;
513
514 iph = (struct iphdr *)skb->data;
515 if (!pskb_may_pull(skb, sizeof(struct iphdr)))
516 goto out;
517 if (iph->ihl < 5 || iph->version != 4)
518 goto out;
519 if (!pskb_may_pull(skb, iph->ihl*4))
520 goto out;
521 if (ip_fast_csum((u8 *)iph, iph->ihl) != 0)
522 goto out;
523
524 len = ntohs(iph->tot_len);
525 if (skb->len < len || len < iph->ihl*4)
526 goto out;
527
528 /*
529 * Our transport medium may have padded the buffer out.
530 * Now We trim to the true length of the frame.
531 */
532 if (pskb_trim_rcsum(skb, len))
533 goto out;
534
535 if (iph->protocol != IPPROTO_UDP)
536 goto out;
537
538 len -= iph->ihl*4;
539 uh = (struct udphdr *)(((char *)iph) + iph->ihl*4);
540 ulen = ntohs(uh->len);
541
542 if (ulen != len)
543 goto out;
544 if (checksum_udp(skb, uh, ulen, iph->saddr, iph->daddr))
545 goto out;
546 if (np->local_ip && np->local_ip != ntohl(iph->daddr))
547 goto out;
548 if (np->remote_ip && np->remote_ip != ntohl(iph->saddr))
549 goto out;
550 if (np->local_port && np->local_port != ntohs(uh->dest))
551 goto out;
552
553 np->rx_hook(np, ntohs(uh->source),
554 (char *)(uh+1),
555 ulen - sizeof(struct udphdr));
556
557 kfree_skb(skb);
558 return 1;
559
560 out:
561 if (atomic_read(&trapped)) {
562 kfree_skb(skb);
563 return 1;
564 }
565
566 return 0;
567 }
568
569 void netpoll_print_options(struct netpoll *np)
570 {
571 DECLARE_MAC_BUF(mac);
572 printk(KERN_INFO "%s: local port %d\n",
573 np->name, np->local_port);
574 printk(KERN_INFO "%s: local IP %d.%d.%d.%d\n",
575 np->name, HIPQUAD(np->local_ip));
576 printk(KERN_INFO "%s: interface %s\n",
577 np->name, np->dev_name);
578 printk(KERN_INFO "%s: remote port %d\n",
579 np->name, np->remote_port);
580 printk(KERN_INFO "%s: remote IP %d.%d.%d.%d\n",
581 np->name, HIPQUAD(np->remote_ip));
582 printk(KERN_INFO "%s: remote ethernet address %s\n",
583 np->name, print_mac(mac, np->remote_mac));
584 }
585
586 int netpoll_parse_options(struct netpoll *np, char *opt)
587 {
588 char *cur=opt, *delim;
589
590 if (*cur != '@') {
591 if ((delim = strchr(cur, '@')) == NULL)
592 goto parse_failed;
593 *delim = 0;
594 np->local_port = simple_strtol(cur, NULL, 10);
595 cur = delim;
596 }
597 cur++;
598
599 if (*cur != '/') {
600 if ((delim = strchr(cur, '/')) == NULL)
601 goto parse_failed;
602 *delim = 0;
603 np->local_ip = ntohl(in_aton(cur));
604 cur = delim;
605 }
606 cur++;
607
608 if (*cur != ',') {
609 /* parse out dev name */
610 if ((delim = strchr(cur, ',')) == NULL)
611 goto parse_failed;
612 *delim = 0;
613 strlcpy(np->dev_name, cur, sizeof(np->dev_name));
614 cur = delim;
615 }
616 cur++;
617
618 if (*cur != '@') {
619 /* dst port */
620 if ((delim = strchr(cur, '@')) == NULL)
621 goto parse_failed;
622 *delim = 0;
623 np->remote_port = simple_strtol(cur, NULL, 10);
624 cur = delim;
625 }
626 cur++;
627
628 /* dst ip */
629 if ((delim = strchr(cur, '/')) == NULL)
630 goto parse_failed;
631 *delim = 0;
632 np->remote_ip = ntohl(in_aton(cur));
633 cur = delim + 1;
634
635 if (*cur != 0) {
636 /* MAC address */
637 if ((delim = strchr(cur, ':')) == NULL)
638 goto parse_failed;
639 *delim = 0;
640 np->remote_mac[0] = simple_strtol(cur, NULL, 16);
641 cur = delim + 1;
642 if ((delim = strchr(cur, ':')) == NULL)
643 goto parse_failed;
644 *delim = 0;
645 np->remote_mac[1] = simple_strtol(cur, NULL, 16);
646 cur = delim + 1;
647 if ((delim = strchr(cur, ':')) == NULL)
648 goto parse_failed;
649 *delim = 0;
650 np->remote_mac[2] = simple_strtol(cur, NULL, 16);
651 cur = delim + 1;
652 if ((delim = strchr(cur, ':')) == NULL)
653 goto parse_failed;
654 *delim = 0;
655 np->remote_mac[3] = simple_strtol(cur, NULL, 16);
656 cur = delim + 1;
657 if ((delim = strchr(cur, ':')) == NULL)
658 goto parse_failed;
659 *delim = 0;
660 np->remote_mac[4] = simple_strtol(cur, NULL, 16);
661 cur = delim + 1;
662 np->remote_mac[5] = simple_strtol(cur, NULL, 16);
663 }
664
665 netpoll_print_options(np);
666
667 return 0;
668
669 parse_failed:
670 printk(KERN_INFO "%s: couldn't parse config at %s!\n",
671 np->name, cur);
672 return -1;
673 }
674
675 int netpoll_setup(struct netpoll *np)
676 {
677 struct net_device *ndev = NULL;
678 struct in_device *in_dev;
679 struct netpoll_info *npinfo;
680 unsigned long flags;
681 int err;
682
683 if (np->dev_name)
684 ndev = dev_get_by_name(&init_net, np->dev_name);
685 if (!ndev) {
686 printk(KERN_ERR "%s: %s doesn't exist, aborting.\n",
687 np->name, np->dev_name);
688 return -ENODEV;
689 }
690
691 np->dev = ndev;
692 if (!ndev->npinfo) {
693 npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL);
694 if (!npinfo) {
695 err = -ENOMEM;
696 goto release;
697 }
698
699 npinfo->rx_flags = 0;
700 npinfo->rx_np = NULL;
701
702 spin_lock_init(&npinfo->rx_lock);
703 skb_queue_head_init(&npinfo->arp_tx);
704 skb_queue_head_init(&npinfo->txq);
705 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process);
706
707 atomic_set(&npinfo->refcnt, 1);
708 } else {
709 npinfo = ndev->npinfo;
710 atomic_inc(&npinfo->refcnt);
711 }
712
713 if (!ndev->poll_controller) {
714 printk(KERN_ERR "%s: %s doesn't support polling, aborting.\n",
715 np->name, np->dev_name);
716 err = -ENOTSUPP;
717 goto release;
718 }
719
720 if (!netif_running(ndev)) {
721 unsigned long atmost, atleast;
722
723 printk(KERN_INFO "%s: device %s not up yet, forcing it\n",
724 np->name, np->dev_name);
725
726 rtnl_lock();
727 err = dev_open(ndev);
728 rtnl_unlock();
729
730 if (err) {
731 printk(KERN_ERR "%s: failed to open %s\n",
732 np->name, ndev->name);
733 goto release;
734 }
735
736 atleast = jiffies + HZ/10;
737 atmost = jiffies + 4*HZ;
738 while (!netif_carrier_ok(ndev)) {
739 if (time_after(jiffies, atmost)) {
740 printk(KERN_NOTICE
741 "%s: timeout waiting for carrier\n",
742 np->name);
743 break;
744 }
745 schedule_timeout_uninterruptible(1);
746 }
747
748 /* If carrier appears to come up instantly, we don't
749 * trust it and pause so that we don't pump all our
750 * queued console messages into the bitbucket.
751 */
752
753 if (time_before(jiffies, atleast)) {
754 printk(KERN_NOTICE "%s: carrier detect appears"
755 " untrustworthy, waiting 4 seconds\n",
756 np->name);
757 msleep(4000);
758 }
759 }
760
761 if (!np->local_ip) {
762 rcu_read_lock();
763 in_dev = __in_dev_get_rcu(ndev);
764
765 if (!in_dev || !in_dev->ifa_list) {
766 rcu_read_unlock();
767 printk(KERN_ERR "%s: no IP address for %s, aborting\n",
768 np->name, np->dev_name);
769 err = -EDESTADDRREQ;
770 goto release;
771 }
772
773 np->local_ip = ntohl(in_dev->ifa_list->ifa_local);
774 rcu_read_unlock();
775 printk(KERN_INFO "%s: local IP %d.%d.%d.%d\n",
776 np->name, HIPQUAD(np->local_ip));
777 }
778
779 if (np->rx_hook) {
780 spin_lock_irqsave(&npinfo->rx_lock, flags);
781 npinfo->rx_flags |= NETPOLL_RX_ENABLED;
782 npinfo->rx_np = np;
783 spin_unlock_irqrestore(&npinfo->rx_lock, flags);
784 }
785
786 /* fill up the skb queue */
787 refill_skbs();
788
789 /* last thing to do is link it to the net device structure */
790 ndev->npinfo = npinfo;
791
792 /* avoid racing with NAPI reading npinfo */
793 synchronize_rcu();
794
795 return 0;
796
797 release:
798 if (!ndev->npinfo)
799 kfree(npinfo);
800 np->dev = NULL;
801 dev_put(ndev);
802 return err;
803 }
804
805 static int __init netpoll_init(void)
806 {
807 skb_queue_head_init(&skb_pool);
808 return 0;
809 }
810 core_initcall(netpoll_init);
811
812 void netpoll_cleanup(struct netpoll *np)
813 {
814 struct netpoll_info *npinfo;
815 unsigned long flags;
816
817 if (np->dev) {
818 npinfo = np->dev->npinfo;
819 if (npinfo) {
820 if (npinfo->rx_np == np) {
821 spin_lock_irqsave(&npinfo->rx_lock, flags);
822 npinfo->rx_np = NULL;
823 npinfo->rx_flags &= ~NETPOLL_RX_ENABLED;
824 spin_unlock_irqrestore(&npinfo->rx_lock, flags);
825 }
826
827 if (atomic_dec_and_test(&npinfo->refcnt)) {
828 skb_queue_purge(&npinfo->arp_tx);
829 skb_queue_purge(&npinfo->txq);
830 cancel_rearming_delayed_work(&npinfo->tx_work);
831
832 /* clean after last, unfinished work */
833 __skb_queue_purge(&npinfo->txq);
834 kfree(npinfo);
835 np->dev->npinfo = NULL;
836 }
837 }
838
839 dev_put(np->dev);
840 }
841
842 np->dev = NULL;
843 }
844
845 int netpoll_trap(void)
846 {
847 return atomic_read(&trapped);
848 }
849
850 void netpoll_set_trap(int trap)
851 {
852 if (trap)
853 atomic_inc(&trapped);
854 else
855 atomic_dec(&trapped);
856 }
857
858 EXPORT_SYMBOL(netpoll_set_trap);
859 EXPORT_SYMBOL(netpoll_trap);
860 EXPORT_SYMBOL(netpoll_print_options);
861 EXPORT_SYMBOL(netpoll_parse_options);
862 EXPORT_SYMBOL(netpoll_setup);
863 EXPORT_SYMBOL(netpoll_cleanup);
864 EXPORT_SYMBOL(netpoll_send_udp);
865 EXPORT_SYMBOL(netpoll_poll);
866
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