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net: txq_trans_update() helper
[linux-2.6/verdex.git] / net / core / netpoll.c
blob7ab31a7576a17c3a7fe7560d11e78007d2bc6218
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 #include <trace/napi.h>
28
29 /*
30 * We maintain a small pool of fully-sized skbs, to make sure the
31 * message gets out even in extreme OOM situations.
32 */
33
34 #define MAX_UDP_CHUNK 1460
35 #define MAX_SKBS 32
36 #define MAX_QUEUE_DEPTH (MAX_SKBS / 2)
37
38 static struct sk_buff_head skb_pool;
39
40 static atomic_t trapped;
41
42 #define USEC_PER_POLL 50
43 #define NETPOLL_RX_ENABLED 1
44 #define NETPOLL_RX_DROP 2
45
46 #define MAX_SKB_SIZE \
47 (MAX_UDP_CHUNK + sizeof(struct udphdr) + \
48 sizeof(struct iphdr) + sizeof(struct ethhdr))
49
50 static void zap_completion_queue(void);
51 static void arp_reply(struct sk_buff *skb);
52
53 static void queue_process(struct work_struct *work)
54 {
55 struct netpoll_info *npinfo =
56 container_of(work, struct netpoll_info, tx_work.work);
57 struct sk_buff *skb;
58 unsigned long flags;
59
60 while ((skb = skb_dequeue(&npinfo->txq))) {
61 struct net_device *dev = skb->dev;
62 const struct net_device_ops *ops = dev->netdev_ops;
63 struct netdev_queue *txq;
64
65 if (!netif_device_present(dev) || !netif_running(dev)) {
66 __kfree_skb(skb);
67 continue;
68 }
69
70 txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb));
71
72 local_irq_save(flags);
73 __netif_tx_lock(txq, smp_processor_id());
74 if (netif_tx_queue_stopped(txq) ||
75 netif_tx_queue_frozen(txq) ||
76 ops->ndo_start_xmit(skb, dev) != NETDEV_TX_OK) {
77 skb_queue_head(&npinfo->txq, skb);
78 __netif_tx_unlock(txq);
79 local_irq_restore(flags);
80
81 schedule_delayed_work(&npinfo->tx_work, HZ/10);
82 return;
83 }
84 __netif_tx_unlock(txq);
85 local_irq_restore(flags);
86 }
87 }
88
89 static __sum16 checksum_udp(struct sk_buff *skb, struct udphdr *uh,
90 unsigned short ulen, __be32 saddr, __be32 daddr)
91 {
92 __wsum psum;
93
94 if (uh->check == 0 || skb_csum_unnecessary(skb))
95 return 0;
96
97 psum = csum_tcpudp_nofold(saddr, daddr, ulen, IPPROTO_UDP, 0);
98
99 if (skb->ip_summed == CHECKSUM_COMPLETE &&
100 !csum_fold(csum_add(psum, skb->csum)))
101 return 0;
102
103 skb->csum = psum;
104
105 return __skb_checksum_complete(skb);
106 }
107
108 /*
109 * Check whether delayed processing was scheduled for our NIC. If so,
110 * we attempt to grab the poll lock and use ->poll() to pump the card.
111 * If this fails, either we've recursed in ->poll() or it's already
112 * running on another CPU.
113 *
114 * Note: we don't mask interrupts with this lock because we're using
115 * trylock here and interrupts are already disabled in the softirq
116 * case. Further, we test the poll_owner to avoid recursion on UP
117 * systems where the lock doesn't exist.
118 *
119 * In cases where there is bi-directional communications, reading only
120 * one message at a time can lead to packets being dropped by the
121 * network adapter, forcing superfluous retries and possibly timeouts.
122 * Thus, we set our budget to greater than 1.
123 */
124 static int poll_one_napi(struct netpoll_info *npinfo,
125 struct napi_struct *napi, int budget)
126 {
127 int work;
128
129 /* net_rx_action's ->poll() invocations and our's are
130 * synchronized by this test which is only made while
131 * holding the napi->poll_lock.
132 */
133 if (!test_bit(NAPI_STATE_SCHED, &napi->state))
134 return budget;
135
136 npinfo->rx_flags |= NETPOLL_RX_DROP;
137 atomic_inc(&trapped);
138 set_bit(NAPI_STATE_NPSVC, &napi->state);
139
140 work = napi->poll(napi, budget);
141 trace_napi_poll(napi);
142
143 clear_bit(NAPI_STATE_NPSVC, &napi->state);
144 atomic_dec(&trapped);
145 npinfo->rx_flags &= ~NETPOLL_RX_DROP;
146
147 return budget - work;
148 }
149
150 static void poll_napi(struct net_device *dev)
151 {
152 struct napi_struct *napi;
153 int budget = 16;
154
155 list_for_each_entry(napi, &dev->napi_list, dev_list) {
156 if (napi->poll_owner != smp_processor_id() &&
157 spin_trylock(&napi->poll_lock)) {
158 budget = poll_one_napi(dev->npinfo, napi, budget);
159 spin_unlock(&napi->poll_lock);
160
161 if (!budget)
162 break;
163 }
164 }
165 }
166
167 static void service_arp_queue(struct netpoll_info *npi)
168 {
169 if (npi) {
170 struct sk_buff *skb;
171
172 while ((skb = skb_dequeue(&npi->arp_tx)))
173 arp_reply(skb);
174 }
175 }
176
177 void netpoll_poll(struct netpoll *np)
178 {
179 struct net_device *dev = np->dev;
180 const struct net_device_ops *ops;
181
182 if (!dev || !netif_running(dev))
183 return;
184
185 ops = dev->netdev_ops;
186 if (!ops->ndo_poll_controller)
187 return;
188
189 /* Process pending work on NIC */
190 ops->ndo_poll_controller(dev);
191
192 poll_napi(dev);
193
194 service_arp_queue(dev->npinfo);
195
196 zap_completion_queue();
197 }
198
199 static void refill_skbs(void)
200 {
201 struct sk_buff *skb;
202 unsigned long flags;
203
204 spin_lock_irqsave(&skb_pool.lock, flags);
205 while (skb_pool.qlen < MAX_SKBS) {
206 skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC);
207 if (!skb)
208 break;
209
210 __skb_queue_tail(&skb_pool, skb);
211 }
212 spin_unlock_irqrestore(&skb_pool.lock, flags);
213 }
214
215 static void zap_completion_queue(void)
216 {
217 unsigned long flags;
218 struct softnet_data *sd = &get_cpu_var(softnet_data);
219
220 if (sd->completion_queue) {
221 struct sk_buff *clist;
222
223 local_irq_save(flags);
224 clist = sd->completion_queue;
225 sd->completion_queue = NULL;
226 local_irq_restore(flags);
227
228 while (clist != NULL) {
229 struct sk_buff *skb = clist;
230 clist = clist->next;
231 if (skb->destructor) {
232 atomic_inc(&skb->users);
233 dev_kfree_skb_any(skb); /* put this one back */
234 } else {
235 __kfree_skb(skb);
236 }
237 }
238 }
239
240 put_cpu_var(softnet_data);
241 }
242
243 static struct sk_buff *find_skb(struct netpoll *np, int len, int reserve)
244 {
245 int count = 0;
246 struct sk_buff *skb;
247
248 zap_completion_queue();
249 refill_skbs();
250 repeat:
251
252 skb = alloc_skb(len, GFP_ATOMIC);
253 if (!skb)
254 skb = skb_dequeue(&skb_pool);
255
256 if (!skb) {
257 if (++count < 10) {
258 netpoll_poll(np);
259 goto repeat;
260 }
261 return NULL;
262 }
263
264 atomic_set(&skb->users, 1);
265 skb_reserve(skb, reserve);
266 return skb;
267 }
268
269 static int netpoll_owner_active(struct net_device *dev)
270 {
271 struct napi_struct *napi;
272
273 list_for_each_entry(napi, &dev->napi_list, dev_list) {
274 if (napi->poll_owner == smp_processor_id())
275 return 1;
276 }
277 return 0;
278 }
279
280 static void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
281 {
282 int status = NETDEV_TX_BUSY;
283 unsigned long tries;
284 struct net_device *dev = np->dev;
285 const struct net_device_ops *ops = dev->netdev_ops;
286 struct netpoll_info *npinfo = np->dev->npinfo;
287
288 if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) {
289 __kfree_skb(skb);
290 return;
291 }
292
293 /* don't get messages out of order, and no recursion */
294 if (skb_queue_len(&npinfo->txq) == 0 && !netpoll_owner_active(dev)) {
295 struct netdev_queue *txq;
296 unsigned long flags;
297
298 txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb));
299
300 local_irq_save(flags);
301 /* try until next clock tick */
302 for (tries = jiffies_to_usecs(1)/USEC_PER_POLL;
303 tries > 0; --tries) {
304 if (__netif_tx_trylock(txq)) {
305 if (!netif_tx_queue_stopped(txq)) {
306 status = ops->ndo_start_xmit(skb, dev);
307 if (status == NETDEV_TX_OK)
308 txq_trans_update(txq);
309 }
310 __netif_tx_unlock(txq);
311
312 if (status == NETDEV_TX_OK)
313 break;
314
315 }
316
317 /* tickle device maybe there is some cleanup */
318 netpoll_poll(np);
319
320 udelay(USEC_PER_POLL);
321 }
322 local_irq_restore(flags);
323 }
324
325 if (status != NETDEV_TX_OK) {
326 skb_queue_tail(&npinfo->txq, skb);
327 schedule_delayed_work(&npinfo->tx_work,0);
328 }
329 }
330
331 void netpoll_send_udp(struct netpoll *np, const char *msg, int len)
332 {
333 int total_len, eth_len, ip_len, udp_len;
334 struct sk_buff *skb;
335 struct udphdr *udph;
336 struct iphdr *iph;
337 struct ethhdr *eth;
338
339 udp_len = len + sizeof(*udph);
340 ip_len = eth_len = udp_len + sizeof(*iph);
341 total_len = eth_len + ETH_HLEN + NET_IP_ALIGN;
342
343 skb = find_skb(np, total_len, total_len - len);
344 if (!skb)
345 return;
346
347 skb_copy_to_linear_data(skb, msg, len);
348 skb->len += len;
349
350 skb_push(skb, sizeof(*udph));
351 skb_reset_transport_header(skb);
352 udph = udp_hdr(skb);
353 udph->source = htons(np->local_port);
354 udph->dest = htons(np->remote_port);
355 udph->len = htons(udp_len);
356 udph->check = 0;
357 udph->check = csum_tcpudp_magic(np->local_ip,
358 np->remote_ip,
359 udp_len, IPPROTO_UDP,
360 csum_partial(udph, udp_len, 0));
361 if (udph->check == 0)
362 udph->check = CSUM_MANGLED_0;
363
364 skb_push(skb, sizeof(*iph));
365 skb_reset_network_header(skb);
366 iph = ip_hdr(skb);
367
368 /* iph->version = 4; iph->ihl = 5; */
369 put_unaligned(0x45, (unsigned char *)iph);
370 iph->tos = 0;
371 put_unaligned(htons(ip_len), &(iph->tot_len));
372 iph->id = 0;
373 iph->frag_off = 0;
374 iph->ttl = 64;
375 iph->protocol = IPPROTO_UDP;
376 iph->check = 0;
377 put_unaligned(np->local_ip, &(iph->saddr));
378 put_unaligned(np->remote_ip, &(iph->daddr));
379 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl);
380
381 eth = (struct ethhdr *) skb_push(skb, ETH_HLEN);
382 skb_reset_mac_header(skb);
383 skb->protocol = eth->h_proto = htons(ETH_P_IP);
384 memcpy(eth->h_source, np->dev->dev_addr, ETH_ALEN);
385 memcpy(eth->h_dest, np->remote_mac, ETH_ALEN);
386
387 skb->dev = np->dev;
388
389 netpoll_send_skb(np, skb);
390 }
391
392 static void arp_reply(struct sk_buff *skb)
393 {
394 struct netpoll_info *npinfo = skb->dev->npinfo;
395 struct arphdr *arp;
396 unsigned char *arp_ptr;
397 int size, type = ARPOP_REPLY, ptype = ETH_P_ARP;
398 __be32 sip, tip;
399 unsigned char *sha;
400 struct sk_buff *send_skb;
401 struct netpoll *np = NULL;
402
403 if (npinfo->rx_np && npinfo->rx_np->dev == skb->dev)
404 np = npinfo->rx_np;
405 if (!np)
406 return;
407
408 /* No arp on this interface */
409 if (skb->dev->flags & IFF_NOARP)
410 return;
411
412 if (!pskb_may_pull(skb, arp_hdr_len(skb->dev)))
413 return;
414
415 skb_reset_network_header(skb);
416 skb_reset_transport_header(skb);
417 arp = arp_hdr(skb);
418
419 if ((arp->ar_hrd != htons(ARPHRD_ETHER) &&
420 arp->ar_hrd != htons(ARPHRD_IEEE802)) ||
421 arp->ar_pro != htons(ETH_P_IP) ||
422 arp->ar_op != htons(ARPOP_REQUEST))
423 return;
424
425 arp_ptr = (unsigned char *)(arp+1);
426 /* save the location of the src hw addr */
427 sha = arp_ptr;
428 arp_ptr += skb->dev->addr_len;
429 memcpy(&sip, arp_ptr, 4);
430 arp_ptr += 4;
431 /* if we actually cared about dst hw addr, it would get copied here */
432 arp_ptr += skb->dev->addr_len;
433 memcpy(&tip, arp_ptr, 4);
434
435 /* Should we ignore arp? */
436 if (tip != np->local_ip ||
437 ipv4_is_loopback(tip) || ipv4_is_multicast(tip))
438 return;
439
440 size = arp_hdr_len(skb->dev);
441 send_skb = find_skb(np, size + LL_ALLOCATED_SPACE(np->dev),
442 LL_RESERVED_SPACE(np->dev));
443
444 if (!send_skb)
445 return;
446
447 skb_reset_network_header(send_skb);
448 arp = (struct arphdr *) skb_put(send_skb, size);
449 send_skb->dev = skb->dev;
450 send_skb->protocol = htons(ETH_P_ARP);
451
452 /* Fill the device header for the ARP frame */
453 if (dev_hard_header(send_skb, skb->dev, ptype,
454 sha, np->dev->dev_addr,
455 send_skb->len) < 0) {
456 kfree_skb(send_skb);
457 return;
458 }
459
460 /*
461 * Fill out the arp protocol part.
462 *
463 * we only support ethernet device type,
464 * which (according to RFC 1390) should always equal 1 (Ethernet).
465 */
466
467 arp->ar_hrd = htons(np->dev->type);
468 arp->ar_pro = htons(ETH_P_IP);
469 arp->ar_hln = np->dev->addr_len;
470 arp->ar_pln = 4;
471 arp->ar_op = htons(type);
472
473 arp_ptr=(unsigned char *)(arp + 1);
474 memcpy(arp_ptr, np->dev->dev_addr, np->dev->addr_len);
475 arp_ptr += np->dev->addr_len;
476 memcpy(arp_ptr, &tip, 4);
477 arp_ptr += 4;
478 memcpy(arp_ptr, sha, np->dev->addr_len);
479 arp_ptr += np->dev->addr_len;
480 memcpy(arp_ptr, &sip, 4);
481
482 netpoll_send_skb(np, send_skb);
483 }
484
485 int __netpoll_rx(struct sk_buff *skb)
486 {
487 int proto, len, ulen;
488 struct iphdr *iph;
489 struct udphdr *uh;
490 struct netpoll_info *npi = skb->dev->npinfo;
491 struct netpoll *np = npi->rx_np;
492
493 if (!np)
494 goto out;
495 if (skb->dev->type != ARPHRD_ETHER)
496 goto out;
497
498 /* check if netpoll clients need ARP */
499 if (skb->protocol == htons(ETH_P_ARP) &&
500 atomic_read(&trapped)) {
501 skb_queue_tail(&npi->arp_tx, skb);
502 return 1;
503 }
504
505 proto = ntohs(eth_hdr(skb)->h_proto);
506 if (proto != ETH_P_IP)
507 goto out;
508 if (skb->pkt_type == PACKET_OTHERHOST)
509 goto out;
510 if (skb_shared(skb))
511 goto out;
512
513 iph = (struct iphdr *)skb->data;
514 if (!pskb_may_pull(skb, sizeof(struct iphdr)))
515 goto out;
516 if (iph->ihl < 5 || iph->version != 4)
517 goto out;
518 if (!pskb_may_pull(skb, iph->ihl*4))
519 goto out;
520 if (ip_fast_csum((u8 *)iph, iph->ihl) != 0)
521 goto out;
522
523 len = ntohs(iph->tot_len);
524 if (skb->len < len || len < iph->ihl*4)
525 goto out;
526
527 /*
528 * Our transport medium may have padded the buffer out.
529 * Now We trim to the true length of the frame.
530 */
531 if (pskb_trim_rcsum(skb, len))
532 goto out;
533
534 if (iph->protocol != IPPROTO_UDP)
535 goto out;
536
537 len -= iph->ihl*4;
538 uh = (struct udphdr *)(((char *)iph) + iph->ihl*4);
539 ulen = ntohs(uh->len);
540
541 if (ulen != len)
542 goto out;
543 if (checksum_udp(skb, uh, ulen, iph->saddr, iph->daddr))
544 goto out;
545 if (np->local_ip && np->local_ip != iph->daddr)
546 goto out;
547 if (np->remote_ip && np->remote_ip != iph->saddr)
548 goto out;
549 if (np->local_port && np->local_port != ntohs(uh->dest))
550 goto out;
551
552 np->rx_hook(np, ntohs(uh->source),
553 (char *)(uh+1),
554 ulen - sizeof(struct udphdr));
555
556 kfree_skb(skb);
557 return 1;
558
559 out:
560 if (atomic_read(&trapped)) {
561 kfree_skb(skb);
562 return 1;
563 }
564
565 return 0;
566 }
567
568 void netpoll_print_options(struct netpoll *np)
569 {
570 printk(KERN_INFO "%s: local port %d\n",
571 np->name, np->local_port);
572 printk(KERN_INFO "%s: local IP %pI4\n",
573 np->name, &np->local_ip);
574 printk(KERN_INFO "%s: interface %s\n",
575 np->name, np->dev_name);
576 printk(KERN_INFO "%s: remote port %d\n",
577 np->name, np->remote_port);
578 printk(KERN_INFO "%s: remote IP %pI4\n",
579 np->name, &np->remote_ip);
580 printk(KERN_INFO "%s: remote ethernet address %pM\n",
581 np->name, np->remote_mac);
582 }
583
584 int netpoll_parse_options(struct netpoll *np, char *opt)
585 {
586 char *cur=opt, *delim;
587
588 if (*cur != '@') {
589 if ((delim = strchr(cur, '@')) == NULL)
590 goto parse_failed;
591 *delim = 0;
592 np->local_port = simple_strtol(cur, NULL, 10);
593 cur = delim;
594 }
595 cur++;
596
597 if (*cur != '/') {
598 if ((delim = strchr(cur, '/')) == NULL)
599 goto parse_failed;
600 *delim = 0;
601 np->local_ip = in_aton(cur);
602 cur = delim;
603 }
604 cur++;
605
606 if (*cur != ',') {
607 /* parse out dev name */
608 if ((delim = strchr(cur, ',')) == NULL)
609 goto parse_failed;
610 *delim = 0;
611 strlcpy(np->dev_name, cur, sizeof(np->dev_name));
612 cur = delim;
613 }
614 cur++;
615
616 if (*cur != '@') {
617 /* dst port */
618 if ((delim = strchr(cur, '@')) == NULL)
619 goto parse_failed;
620 *delim = 0;
621 np->remote_port = simple_strtol(cur, NULL, 10);
622 cur = delim;
623 }
624 cur++;
625
626 /* dst ip */
627 if ((delim = strchr(cur, '/')) == NULL)
628 goto parse_failed;
629 *delim = 0;
630 np->remote_ip = in_aton(cur);
631 cur = delim + 1;
632
633 if (*cur != 0) {
634 /* MAC address */
635 if ((delim = strchr(cur, ':')) == NULL)
636 goto parse_failed;
637 *delim = 0;
638 np->remote_mac[0] = simple_strtol(cur, NULL, 16);
639 cur = delim + 1;
640 if ((delim = strchr(cur, ':')) == NULL)
641 goto parse_failed;
642 *delim = 0;
643 np->remote_mac[1] = simple_strtol(cur, NULL, 16);
644 cur = delim + 1;
645 if ((delim = strchr(cur, ':')) == NULL)
646 goto parse_failed;
647 *delim = 0;
648 np->remote_mac[2] = simple_strtol(cur, NULL, 16);
649 cur = delim + 1;
650 if ((delim = strchr(cur, ':')) == NULL)
651 goto parse_failed;
652 *delim = 0;
653 np->remote_mac[3] = simple_strtol(cur, NULL, 16);
654 cur = delim + 1;
655 if ((delim = strchr(cur, ':')) == NULL)
656 goto parse_failed;
657 *delim = 0;
658 np->remote_mac[4] = simple_strtol(cur, NULL, 16);
659 cur = delim + 1;
660 np->remote_mac[5] = simple_strtol(cur, NULL, 16);
661 }
662
663 netpoll_print_options(np);
664
665 return 0;
666
667 parse_failed:
668 printk(KERN_INFO "%s: couldn't parse config at %s!\n",
669 np->name, cur);
670 return -1;
671 }
672
673 int netpoll_setup(struct netpoll *np)
674 {
675 struct net_device *ndev = NULL;
676 struct in_device *in_dev;
677 struct netpoll_info *npinfo;
678 unsigned long flags;
679 int err;
680
681 if (np->dev_name)
682 ndev = dev_get_by_name(&init_net, np->dev_name);
683 if (!ndev) {
684 printk(KERN_ERR "%s: %s doesn't exist, aborting.\n",
685 np->name, np->dev_name);
686 return -ENODEV;
687 }
688
689 np->dev = ndev;
690 if (!ndev->npinfo) {
691 npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL);
692 if (!npinfo) {
693 err = -ENOMEM;
694 goto release;
695 }
696
697 npinfo->rx_flags = 0;
698 npinfo->rx_np = NULL;
699
700 spin_lock_init(&npinfo->rx_lock);
701 skb_queue_head_init(&npinfo->arp_tx);
702 skb_queue_head_init(&npinfo->txq);
703 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process);
704
705 atomic_set(&npinfo->refcnt, 1);
706 } else {
707 npinfo = ndev->npinfo;
708 atomic_inc(&npinfo->refcnt);
709 }
710
711 if (!ndev->netdev_ops->ndo_poll_controller) {
712 printk(KERN_ERR "%s: %s doesn't support polling, aborting.\n",
713 np->name, np->dev_name);
714 err = -ENOTSUPP;
715 goto release;
716 }
717
718 if (!netif_running(ndev)) {
719 unsigned long atmost, atleast;
720
721 printk(KERN_INFO "%s: device %s not up yet, forcing it\n",
722 np->name, np->dev_name);
723
724 rtnl_lock();
725 err = dev_open(ndev);
726 rtnl_unlock();
727
728 if (err) {
729 printk(KERN_ERR "%s: failed to open %s\n",
730 np->name, ndev->name);
731 goto release;
732 }
733
734 atleast = jiffies + HZ/10;
735 atmost = jiffies + 4*HZ;
736 while (!netif_carrier_ok(ndev)) {
737 if (time_after(jiffies, atmost)) {
738 printk(KERN_NOTICE
739 "%s: timeout waiting for carrier\n",
740 np->name);
741 break;
742 }
743 cond_resched();
744 }
745
746 /* If carrier appears to come up instantly, we don't
747 * trust it and pause so that we don't pump all our
748 * queued console messages into the bitbucket.
749 */
750
751 if (time_before(jiffies, atleast)) {
752 printk(KERN_NOTICE "%s: carrier detect appears"
753 " untrustworthy, waiting 4 seconds\n",
754 np->name);
755 msleep(4000);
756 }
757 }
758
759 if (!np->local_ip) {
760 rcu_read_lock();
761 in_dev = __in_dev_get_rcu(ndev);
762
763 if (!in_dev || !in_dev->ifa_list) {
764 rcu_read_unlock();
765 printk(KERN_ERR "%s: no IP address for %s, aborting\n",
766 np->name, np->dev_name);
767 err = -EDESTADDRREQ;
768 goto release;
769 }
770
771 np->local_ip = in_dev->ifa_list->ifa_local;
772 rcu_read_unlock();
773 printk(KERN_INFO "%s: local IP %pI4\n", np->name, &np->local_ip);
774 }
775
776 if (np->rx_hook) {
777 spin_lock_irqsave(&npinfo->rx_lock, flags);
778 npinfo->rx_flags |= NETPOLL_RX_ENABLED;
779 npinfo->rx_np = np;
780 spin_unlock_irqrestore(&npinfo->rx_lock, flags);
781 }
782
783 /* fill up the skb queue */
784 refill_skbs();
785
786 /* last thing to do is link it to the net device structure */
787 ndev->npinfo = npinfo;
788
789 /* avoid racing with NAPI reading npinfo */
790 synchronize_rcu();
791
792 return 0;
793
794 release:
795 if (!ndev->npinfo)
796 kfree(npinfo);
797 np->dev = NULL;
798 dev_put(ndev);
799 return err;
800 }
801
802 static int __init netpoll_init(void)
803 {
804 skb_queue_head_init(&skb_pool);
805 return 0;
806 }
807 core_initcall(netpoll_init);
808
809 void netpoll_cleanup(struct netpoll *np)
810 {
811 struct netpoll_info *npinfo;
812 unsigned long flags;
813
814 if (np->dev) {
815 npinfo = np->dev->npinfo;
816 if (npinfo) {
817 if (npinfo->rx_np == np) {
818 spin_lock_irqsave(&npinfo->rx_lock, flags);
819 npinfo->rx_np = NULL;
820 npinfo->rx_flags &= ~NETPOLL_RX_ENABLED;
821 spin_unlock_irqrestore(&npinfo->rx_lock, flags);
822 }
823
824 if (atomic_dec_and_test(&npinfo->refcnt)) {
825 skb_queue_purge(&npinfo->arp_tx);
826 skb_queue_purge(&npinfo->txq);
827 cancel_rearming_delayed_work(&npinfo->tx_work);
828
829 /* clean after last, unfinished work */
830 __skb_queue_purge(&npinfo->txq);
831 kfree(npinfo);
832 np->dev->npinfo = NULL;
833 }
834 }
835
836 dev_put(np->dev);
837 }
838
839 np->dev = NULL;
840 }
841
842 int netpoll_trap(void)
843 {
844 return atomic_read(&trapped);
845 }
846
847 void netpoll_set_trap(int trap)
848 {
849 if (trap)
850 atomic_inc(&trapped);
851 else
852 atomic_dec(&trapped);
853 }
854
855 EXPORT_SYMBOL(netpoll_set_trap);
856 EXPORT_SYMBOL(netpoll_trap);
857 EXPORT_SYMBOL(netpoll_print_options);
858 EXPORT_SYMBOL(netpoll_parse_options);
859 EXPORT_SYMBOL(netpoll_setup);
860 EXPORT_SYMBOL(netpoll_cleanup);
861 EXPORT_SYMBOL(netpoll_send_udp);
862 EXPORT_SYMBOL(netpoll_poll);
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