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ACPICA: Reformat comments, no functional changes
[linux-2.6/mini2440.git] / net / core / netpoll.c
blobdadac6281f20392d0431d80a9001a6169ab94ca7
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 struct netdev_queue *txq;
62
63 if (!netif_device_present(dev) || !netif_running(dev)) {
64 __kfree_skb(skb);
65 continue;
66 }
67
68 txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb));
69
70 local_irq_save(flags);
71 __netif_tx_lock(txq, smp_processor_id());
72 if (netif_tx_queue_stopped(txq) ||
73 netif_tx_queue_frozen(txq) ||
74 dev->hard_start_xmit(skb, dev) != NETDEV_TX_OK) {
75 skb_queue_head(&npinfo->txq, skb);
76 __netif_tx_unlock(txq);
77 local_irq_restore(flags);
78
79 schedule_delayed_work(&npinfo->tx_work, HZ/10);
80 return;
81 }
82 __netif_tx_unlock(txq);
83 local_irq_restore(flags);
84 }
85 }
86
87 static __sum16 checksum_udp(struct sk_buff *skb, struct udphdr *uh,
88 unsigned short ulen, __be32 saddr, __be32 daddr)
89 {
90 __wsum psum;
91
92 if (uh->check == 0 || skb_csum_unnecessary(skb))
93 return 0;
94
95 psum = csum_tcpudp_nofold(saddr, daddr, ulen, IPPROTO_UDP, 0);
96
97 if (skb->ip_summed == CHECKSUM_COMPLETE &&
98 !csum_fold(csum_add(psum, skb->csum)))
99 return 0;
100
101 skb->csum = psum;
102
103 return __skb_checksum_complete(skb);
104 }
105
106 /*
107 * Check whether delayed processing was scheduled for our NIC. If so,
108 * we attempt to grab the poll lock and use ->poll() to pump the card.
109 * If this fails, either we've recursed in ->poll() or it's already
110 * running on another CPU.
111 *
112 * Note: we don't mask interrupts with this lock because we're using
113 * trylock here and interrupts are already disabled in the softirq
114 * case. Further, we test the poll_owner to avoid recursion on UP
115 * systems where the lock doesn't exist.
116 *
117 * In cases where there is bi-directional communications, reading only
118 * one message at a time can lead to packets being dropped by the
119 * network adapter, forcing superfluous retries and possibly timeouts.
120 * Thus, we set our budget to greater than 1.
121 */
122 static int poll_one_napi(struct netpoll_info *npinfo,
123 struct napi_struct *napi, int budget)
124 {
125 int work;
126
127 /* net_rx_action's ->poll() invocations and our's are
128 * synchronized by this test which is only made while
129 * holding the napi->poll_lock.
130 */
131 if (!test_bit(NAPI_STATE_SCHED, &napi->state))
132 return budget;
133
134 npinfo->rx_flags |= NETPOLL_RX_DROP;
135 atomic_inc(&trapped);
136 set_bit(NAPI_STATE_NPSVC, &napi->state);
137
138 work = napi->poll(napi, budget);
139
140 clear_bit(NAPI_STATE_NPSVC, &napi->state);
141 atomic_dec(&trapped);
142 npinfo->rx_flags &= ~NETPOLL_RX_DROP;
143
144 return budget - work;
145 }
146
147 static void poll_napi(struct net_device *dev)
148 {
149 struct napi_struct *napi;
150 int budget = 16;
151
152 list_for_each_entry(napi, &dev->napi_list, dev_list) {
153 if (napi->poll_owner != smp_processor_id() &&
154 spin_trylock(&napi->poll_lock)) {
155 budget = poll_one_napi(dev->npinfo, napi, budget);
156 spin_unlock(&napi->poll_lock);
157
158 if (!budget)
159 break;
160 }
161 }
162 }
163
164 static void service_arp_queue(struct netpoll_info *npi)
165 {
166 if (npi) {
167 struct sk_buff *skb;
168
169 while ((skb = skb_dequeue(&npi->arp_tx)))
170 arp_reply(skb);
171 }
172 }
173
174 void netpoll_poll(struct netpoll *np)
175 {
176 struct net_device *dev = np->dev;
177
178 if (!dev || !netif_running(dev) || !dev->poll_controller)
179 return;
180
181 /* Process pending work on NIC */
182 dev->poll_controller(dev);
183
184 poll_napi(dev);
185
186 service_arp_queue(dev->npinfo);
187
188 zap_completion_queue();
189 }
190
191 static void refill_skbs(void)
192 {
193 struct sk_buff *skb;
194 unsigned long flags;
195
196 spin_lock_irqsave(&skb_pool.lock, flags);
197 while (skb_pool.qlen < MAX_SKBS) {
198 skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC);
199 if (!skb)
200 break;
201
202 __skb_queue_tail(&skb_pool, skb);
203 }
204 spin_unlock_irqrestore(&skb_pool.lock, flags);
205 }
206
207 static void zap_completion_queue(void)
208 {
209 unsigned long flags;
210 struct softnet_data *sd = &get_cpu_var(softnet_data);
211
212 if (sd->completion_queue) {
213 struct sk_buff *clist;
214
215 local_irq_save(flags);
216 clist = sd->completion_queue;
217 sd->completion_queue = NULL;
218 local_irq_restore(flags);
219
220 while (clist != NULL) {
221 struct sk_buff *skb = clist;
222 clist = clist->next;
223 if (skb->destructor) {
224 atomic_inc(&skb->users);
225 dev_kfree_skb_any(skb); /* put this one back */
226 } else {
227 __kfree_skb(skb);
228 }
229 }
230 }
231
232 put_cpu_var(softnet_data);
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 zap_completion_queue();
241 refill_skbs();
242 repeat:
243
244 skb = alloc_skb(len, GFP_ATOMIC);
245 if (!skb)
246 skb = skb_dequeue(&skb_pool);
247
248 if (!skb) {
249 if (++count < 10) {
250 netpoll_poll(np);
251 goto repeat;
252 }
253 return NULL;
254 }
255
256 atomic_set(&skb->users, 1);
257 skb_reserve(skb, reserve);
258 return skb;
259 }
260
261 static int netpoll_owner_active(struct net_device *dev)
262 {
263 struct napi_struct *napi;
264
265 list_for_each_entry(napi, &dev->napi_list, dev_list) {
266 if (napi->poll_owner == smp_processor_id())
267 return 1;
268 }
269 return 0;
270 }
271
272 static void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
273 {
274 int status = NETDEV_TX_BUSY;
275 unsigned long tries;
276 struct net_device *dev = np->dev;
277 struct netpoll_info *npinfo = np->dev->npinfo;
278
279 if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) {
280 __kfree_skb(skb);
281 return;
282 }
283
284 /* don't get messages out of order, and no recursion */
285 if (skb_queue_len(&npinfo->txq) == 0 && !netpoll_owner_active(dev)) {
286 struct netdev_queue *txq;
287 unsigned long flags;
288
289 txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb));
290
291 local_irq_save(flags);
292 /* try until next clock tick */
293 for (tries = jiffies_to_usecs(1)/USEC_PER_POLL;
294 tries > 0; --tries) {
295 if (__netif_tx_trylock(txq)) {
296 if (!netif_tx_queue_stopped(txq))
297 status = dev->hard_start_xmit(skb, dev);
298 __netif_tx_unlock(txq);
299
300 if (status == NETDEV_TX_OK)
301 break;
302
303 }
304
305 /* tickle device maybe there is some cleanup */
306 netpoll_poll(np);
307
308 udelay(USEC_PER_POLL);
309 }
310 local_irq_restore(flags);
311 }
312
313 if (status != NETDEV_TX_OK) {
314 skb_queue_tail(&npinfo->txq, skb);
315 schedule_delayed_work(&npinfo->tx_work,0);
316 }
317 }
318
319 void netpoll_send_udp(struct netpoll *np, const char *msg, int len)
320 {
321 int total_len, eth_len, ip_len, udp_len;
322 struct sk_buff *skb;
323 struct udphdr *udph;
324 struct iphdr *iph;
325 struct ethhdr *eth;
326
327 udp_len = len + sizeof(*udph);
328 ip_len = eth_len = udp_len + sizeof(*iph);
329 total_len = eth_len + ETH_HLEN + NET_IP_ALIGN;
330
331 skb = find_skb(np, total_len, total_len - len);
332 if (!skb)
333 return;
334
335 skb_copy_to_linear_data(skb, msg, len);
336 skb->len += len;
337
338 skb_push(skb, sizeof(*udph));
339 skb_reset_transport_header(skb);
340 udph = udp_hdr(skb);
341 udph->source = htons(np->local_port);
342 udph->dest = htons(np->remote_port);
343 udph->len = htons(udp_len);
344 udph->check = 0;
345 udph->check = csum_tcpudp_magic(htonl(np->local_ip),
346 htonl(np->remote_ip),
347 udp_len, IPPROTO_UDP,
348 csum_partial((unsigned char *)udph, udp_len, 0));
349 if (udph->check == 0)
350 udph->check = CSUM_MANGLED_0;
351
352 skb_push(skb, sizeof(*iph));
353 skb_reset_network_header(skb);
354 iph = ip_hdr(skb);
355
356 /* iph->version = 4; iph->ihl = 5; */
357 put_unaligned(0x45, (unsigned char *)iph);
358 iph->tos = 0;
359 put_unaligned(htons(ip_len), &(iph->tot_len));
360 iph->id = 0;
361 iph->frag_off = 0;
362 iph->ttl = 64;
363 iph->protocol = IPPROTO_UDP;
364 iph->check = 0;
365 put_unaligned(htonl(np->local_ip), &(iph->saddr));
366 put_unaligned(htonl(np->remote_ip), &(iph->daddr));
367 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl);
368
369 eth = (struct ethhdr *) skb_push(skb, ETH_HLEN);
370 skb_reset_mac_header(skb);
371 skb->protocol = eth->h_proto = htons(ETH_P_IP);
372 memcpy(eth->h_source, np->dev->dev_addr, ETH_ALEN);
373 memcpy(eth->h_dest, np->remote_mac, ETH_ALEN);
374
375 skb->dev = np->dev;
376
377 netpoll_send_skb(np, skb);
378 }
379
380 static void arp_reply(struct sk_buff *skb)
381 {
382 struct netpoll_info *npinfo = skb->dev->npinfo;
383 struct arphdr *arp;
384 unsigned char *arp_ptr;
385 int size, type = ARPOP_REPLY, ptype = ETH_P_ARP;
386 __be32 sip, tip;
387 unsigned char *sha;
388 struct sk_buff *send_skb;
389 struct netpoll *np = NULL;
390
391 if (npinfo->rx_np && npinfo->rx_np->dev == skb->dev)
392 np = npinfo->rx_np;
393 if (!np)
394 return;
395
396 /* No arp on this interface */
397 if (skb->dev->flags & IFF_NOARP)
398 return;
399
400 if (!pskb_may_pull(skb, arp_hdr_len(skb->dev)))
401 return;
402
403 skb_reset_network_header(skb);
404 skb_reset_transport_header(skb);
405 arp = arp_hdr(skb);
406
407 if ((arp->ar_hrd != htons(ARPHRD_ETHER) &&
408 arp->ar_hrd != htons(ARPHRD_IEEE802)) ||
409 arp->ar_pro != htons(ETH_P_IP) ||
410 arp->ar_op != htons(ARPOP_REQUEST))
411 return;
412
413 arp_ptr = (unsigned char *)(arp+1);
414 /* save the location of the src hw addr */
415 sha = arp_ptr;
416 arp_ptr += skb->dev->addr_len;
417 memcpy(&sip, arp_ptr, 4);
418 arp_ptr += 4;
419 /* if we actually cared about dst hw addr, it would get copied here */
420 arp_ptr += skb->dev->addr_len;
421 memcpy(&tip, arp_ptr, 4);
422
423 /* Should we ignore arp? */
424 if (tip != htonl(np->local_ip) ||
425 ipv4_is_loopback(tip) || ipv4_is_multicast(tip))
426 return;
427
428 size = arp_hdr_len(skb->dev);
429 send_skb = find_skb(np, size + LL_ALLOCATED_SPACE(np->dev),
430 LL_RESERVED_SPACE(np->dev));
431
432 if (!send_skb)
433 return;
434
435 skb_reset_network_header(send_skb);
436 arp = (struct arphdr *) skb_put(send_skb, size);
437 send_skb->dev = skb->dev;
438 send_skb->protocol = htons(ETH_P_ARP);
439
440 /* Fill the device header for the ARP frame */
441 if (dev_hard_header(send_skb, skb->dev, ptype,
442 sha, np->dev->dev_addr,
443 send_skb->len) < 0) {
444 kfree_skb(send_skb);
445 return;
446 }
447
448 /*
449 * Fill out the arp protocol part.
450 *
451 * we only support ethernet device type,
452 * which (according to RFC 1390) should always equal 1 (Ethernet).
453 */
454
455 arp->ar_hrd = htons(np->dev->type);
456 arp->ar_pro = htons(ETH_P_IP);
457 arp->ar_hln = np->dev->addr_len;
458 arp->ar_pln = 4;
459 arp->ar_op = htons(type);
460
461 arp_ptr=(unsigned char *)(arp + 1);
462 memcpy(arp_ptr, np->dev->dev_addr, np->dev->addr_len);
463 arp_ptr += np->dev->addr_len;
464 memcpy(arp_ptr, &tip, 4);
465 arp_ptr += 4;
466 memcpy(arp_ptr, sha, np->dev->addr_len);
467 arp_ptr += np->dev->addr_len;
468 memcpy(arp_ptr, &sip, 4);
469
470 netpoll_send_skb(np, send_skb);
471 }
472
473 int __netpoll_rx(struct sk_buff *skb)
474 {
475 int proto, len, ulen;
476 struct iphdr *iph;
477 struct udphdr *uh;
478 struct netpoll_info *npi = skb->dev->npinfo;
479 struct netpoll *np = npi->rx_np;
480
481 if (!np)
482 goto out;
483 if (skb->dev->type != ARPHRD_ETHER)
484 goto out;
485
486 /* check if netpoll clients need ARP */
487 if (skb->protocol == htons(ETH_P_ARP) &&
488 atomic_read(&trapped)) {
489 skb_queue_tail(&npi->arp_tx, skb);
490 return 1;
491 }
492
493 proto = ntohs(eth_hdr(skb)->h_proto);
494 if (proto != ETH_P_IP)
495 goto out;
496 if (skb->pkt_type == PACKET_OTHERHOST)
497 goto out;
498 if (skb_shared(skb))
499 goto out;
500
501 iph = (struct iphdr *)skb->data;
502 if (!pskb_may_pull(skb, sizeof(struct iphdr)))
503 goto out;
504 if (iph->ihl < 5 || iph->version != 4)
505 goto out;
506 if (!pskb_may_pull(skb, iph->ihl*4))
507 goto out;
508 if (ip_fast_csum((u8 *)iph, iph->ihl) != 0)
509 goto out;
510
511 len = ntohs(iph->tot_len);
512 if (skb->len < len || len < iph->ihl*4)
513 goto out;
514
515 /*
516 * Our transport medium may have padded the buffer out.
517 * Now We trim to the true length of the frame.
518 */
519 if (pskb_trim_rcsum(skb, len))
520 goto out;
521
522 if (iph->protocol != IPPROTO_UDP)
523 goto out;
524
525 len -= iph->ihl*4;
526 uh = (struct udphdr *)(((char *)iph) + iph->ihl*4);
527 ulen = ntohs(uh->len);
528
529 if (ulen != len)
530 goto out;
531 if (checksum_udp(skb, uh, ulen, iph->saddr, iph->daddr))
532 goto out;
533 if (np->local_ip && np->local_ip != ntohl(iph->daddr))
534 goto out;
535 if (np->remote_ip && np->remote_ip != ntohl(iph->saddr))
536 goto out;
537 if (np->local_port && np->local_port != ntohs(uh->dest))
538 goto out;
539
540 np->rx_hook(np, ntohs(uh->source),
541 (char *)(uh+1),
542 ulen - sizeof(struct udphdr));
543
544 kfree_skb(skb);
545 return 1;
546
547 out:
548 if (atomic_read(&trapped)) {
549 kfree_skb(skb);
550 return 1;
551 }
552
553 return 0;
554 }
555
556 void netpoll_print_options(struct netpoll *np)
557 {
558 DECLARE_MAC_BUF(mac);
559 printk(KERN_INFO "%s: local port %d\n",
560 np->name, np->local_port);
561 printk(KERN_INFO "%s: local IP %d.%d.%d.%d\n",
562 np->name, HIPQUAD(np->local_ip));
563 printk(KERN_INFO "%s: interface %s\n",
564 np->name, np->dev_name);
565 printk(KERN_INFO "%s: remote port %d\n",
566 np->name, np->remote_port);
567 printk(KERN_INFO "%s: remote IP %d.%d.%d.%d\n",
568 np->name, HIPQUAD(np->remote_ip));
569 printk(KERN_INFO "%s: remote ethernet address %s\n",
570 np->name, print_mac(mac, np->remote_mac));
571 }
572
573 int netpoll_parse_options(struct netpoll *np, char *opt)
574 {
575 char *cur=opt, *delim;
576
577 if (*cur != '@') {
578 if ((delim = strchr(cur, '@')) == NULL)
579 goto parse_failed;
580 *delim = 0;
581 np->local_port = simple_strtol(cur, NULL, 10);
582 cur = delim;
583 }
584 cur++;
585
586 if (*cur != '/') {
587 if ((delim = strchr(cur, '/')) == NULL)
588 goto parse_failed;
589 *delim = 0;
590 np->local_ip = ntohl(in_aton(cur));
591 cur = delim;
592 }
593 cur++;
594
595 if (*cur != ',') {
596 /* parse out dev name */
597 if ((delim = strchr(cur, ',')) == NULL)
598 goto parse_failed;
599 *delim = 0;
600 strlcpy(np->dev_name, cur, sizeof(np->dev_name));
601 cur = delim;
602 }
603 cur++;
604
605 if (*cur != '@') {
606 /* dst port */
607 if ((delim = strchr(cur, '@')) == NULL)
608 goto parse_failed;
609 *delim = 0;
610 np->remote_port = simple_strtol(cur, NULL, 10);
611 cur = delim;
612 }
613 cur++;
614
615 /* dst ip */
616 if ((delim = strchr(cur, '/')) == NULL)
617 goto parse_failed;
618 *delim = 0;
619 np->remote_ip = ntohl(in_aton(cur));
620 cur = delim + 1;
621
622 if (*cur != 0) {
623 /* MAC address */
624 if ((delim = strchr(cur, ':')) == NULL)
625 goto parse_failed;
626 *delim = 0;
627 np->remote_mac[0] = simple_strtol(cur, NULL, 16);
628 cur = delim + 1;
629 if ((delim = strchr(cur, ':')) == NULL)
630 goto parse_failed;
631 *delim = 0;
632 np->remote_mac[1] = simple_strtol(cur, NULL, 16);
633 cur = delim + 1;
634 if ((delim = strchr(cur, ':')) == NULL)
635 goto parse_failed;
636 *delim = 0;
637 np->remote_mac[2] = simple_strtol(cur, NULL, 16);
638 cur = delim + 1;
639 if ((delim = strchr(cur, ':')) == NULL)
640 goto parse_failed;
641 *delim = 0;
642 np->remote_mac[3] = simple_strtol(cur, NULL, 16);
643 cur = delim + 1;
644 if ((delim = strchr(cur, ':')) == NULL)
645 goto parse_failed;
646 *delim = 0;
647 np->remote_mac[4] = simple_strtol(cur, NULL, 16);
648 cur = delim + 1;
649 np->remote_mac[5] = simple_strtol(cur, NULL, 16);
650 }
651
652 netpoll_print_options(np);
653
654 return 0;
655
656 parse_failed:
657 printk(KERN_INFO "%s: couldn't parse config at %s!\n",
658 np->name, cur);
659 return -1;
660 }
661
662 int netpoll_setup(struct netpoll *np)
663 {
664 struct net_device *ndev = NULL;
665 struct in_device *in_dev;
666 struct netpoll_info *npinfo;
667 unsigned long flags;
668 int err;
669
670 if (np->dev_name)
671 ndev = dev_get_by_name(&init_net, np->dev_name);
672 if (!ndev) {
673 printk(KERN_ERR "%s: %s doesn't exist, aborting.\n",
674 np->name, np->dev_name);
675 return -ENODEV;
676 }
677
678 np->dev = ndev;
679 if (!ndev->npinfo) {
680 npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL);
681 if (!npinfo) {
682 err = -ENOMEM;
683 goto release;
684 }
685
686 npinfo->rx_flags = 0;
687 npinfo->rx_np = NULL;
688
689 spin_lock_init(&npinfo->rx_lock);
690 skb_queue_head_init(&npinfo->arp_tx);
691 skb_queue_head_init(&npinfo->txq);
692 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process);
693
694 atomic_set(&npinfo->refcnt, 1);
695 } else {
696 npinfo = ndev->npinfo;
697 atomic_inc(&npinfo->refcnt);
698 }
699
700 if (!ndev->poll_controller) {
701 printk(KERN_ERR "%s: %s doesn't support polling, aborting.\n",
702 np->name, np->dev_name);
703 err = -ENOTSUPP;
704 goto release;
705 }
706
707 if (!netif_running(ndev)) {
708 unsigned long atmost, atleast;
709
710 printk(KERN_INFO "%s: device %s not up yet, forcing it\n",
711 np->name, np->dev_name);
712
713 rtnl_lock();
714 err = dev_open(ndev);
715 rtnl_unlock();
716
717 if (err) {
718 printk(KERN_ERR "%s: failed to open %s\n",
719 np->name, ndev->name);
720 goto release;
721 }
722
723 atleast = jiffies + HZ/10;
724 atmost = jiffies + 4*HZ;
725 while (!netif_carrier_ok(ndev)) {
726 if (time_after(jiffies, atmost)) {
727 printk(KERN_NOTICE
728 "%s: timeout waiting for carrier\n",
729 np->name);
730 break;
731 }
732 cond_resched();
733 }
734
735 /* If carrier appears to come up instantly, we don't
736 * trust it and pause so that we don't pump all our
737 * queued console messages into the bitbucket.
738 */
739
740 if (time_before(jiffies, atleast)) {
741 printk(KERN_NOTICE "%s: carrier detect appears"
742 " untrustworthy, waiting 4 seconds\n",
743 np->name);
744 msleep(4000);
745 }
746 }
747
748 if (!np->local_ip) {
749 rcu_read_lock();
750 in_dev = __in_dev_get_rcu(ndev);
751
752 if (!in_dev || !in_dev->ifa_list) {
753 rcu_read_unlock();
754 printk(KERN_ERR "%s: no IP address for %s, aborting\n",
755 np->name, np->dev_name);
756 err = -EDESTADDRREQ;
757 goto release;
758 }
759
760 np->local_ip = ntohl(in_dev->ifa_list->ifa_local);
761 rcu_read_unlock();
762 printk(KERN_INFO "%s: local IP %d.%d.%d.%d\n",
763 np->name, HIPQUAD(np->local_ip));
764 }
765
766 if (np->rx_hook) {
767 spin_lock_irqsave(&npinfo->rx_lock, flags);
768 npinfo->rx_flags |= NETPOLL_RX_ENABLED;
769 npinfo->rx_np = np;
770 spin_unlock_irqrestore(&npinfo->rx_lock, flags);
771 }
772
773 /* fill up the skb queue */
774 refill_skbs();
775
776 /* last thing to do is link it to the net device structure */
777 ndev->npinfo = npinfo;
778
779 /* avoid racing with NAPI reading npinfo */
780 synchronize_rcu();
781
782 return 0;
783
784 release:
785 if (!ndev->npinfo)
786 kfree(npinfo);
787 np->dev = NULL;
788 dev_put(ndev);
789 return err;
790 }
791
792 static int __init netpoll_init(void)
793 {
794 skb_queue_head_init(&skb_pool);
795 return 0;
796 }
797 core_initcall(netpoll_init);
798
799 void netpoll_cleanup(struct netpoll *np)
800 {
801 struct netpoll_info *npinfo;
802 unsigned long flags;
803
804 if (np->dev) {
805 npinfo = np->dev->npinfo;
806 if (npinfo) {
807 if (npinfo->rx_np == np) {
808 spin_lock_irqsave(&npinfo->rx_lock, flags);
809 npinfo->rx_np = NULL;
810 npinfo->rx_flags &= ~NETPOLL_RX_ENABLED;
811 spin_unlock_irqrestore(&npinfo->rx_lock, flags);
812 }
813
814 if (atomic_dec_and_test(&npinfo->refcnt)) {
815 skb_queue_purge(&npinfo->arp_tx);
816 skb_queue_purge(&npinfo->txq);
817 cancel_rearming_delayed_work(&npinfo->tx_work);
818
819 /* clean after last, unfinished work */
820 __skb_queue_purge(&npinfo->txq);
821 kfree(npinfo);
822 np->dev->npinfo = NULL;
823 }
824 }
825
826 dev_put(np->dev);
827 }
828
829 np->dev = NULL;
830 }
831
832 int netpoll_trap(void)
833 {
834 return atomic_read(&trapped);
835 }
836
837 void netpoll_set_trap(int trap)
838 {
839 if (trap)
840 atomic_inc(&trapped);
841 else
842 atomic_dec(&trapped);
843 }
844
845 EXPORT_SYMBOL(netpoll_set_trap);
846 EXPORT_SYMBOL(netpoll_trap);
847 EXPORT_SYMBOL(netpoll_print_options);
848 EXPORT_SYMBOL(netpoll_parse_options);
849 EXPORT_SYMBOL(netpoll_setup);
850 EXPORT_SYMBOL(netpoll_cleanup);
851 EXPORT_SYMBOL(netpoll_send_udp);
852 EXPORT_SYMBOL(netpoll_poll);
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