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Pull bugzilla-9429 into release branch
[wrt350n-kernel.git] / net / core / netpoll.c
blobc499b5c69bedbce96611baaec02eb9cfcb0798a6
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(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(flags);
75
76 schedule_delayed_work(&npinfo->tx_work, HZ/10);
77 return;
78 }
79 netif_tx_unlock(dev);
80 local_irq_restore(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 netpoll *np)
143 {
144 struct netpoll_info *npinfo = np->dev->npinfo;
145 struct napi_struct *napi;
146 int budget = 16;
147
148 list_for_each_entry(napi, &np->dev->napi_list, dev_list) {
149 if (napi->poll_owner != smp_processor_id() &&
150 spin_trylock(&napi->poll_lock)) {
151 budget = poll_one_napi(npinfo, napi, budget);
152 spin_unlock(&napi->poll_lock);
153
154 if (!budget)
155 break;
156 }
157 }
158 }
159
160 static void service_arp_queue(struct netpoll_info *npi)
161 {
162 struct sk_buff *skb;
163
164 if (unlikely(!npi))
165 return;
166
167 skb = skb_dequeue(&npi->arp_tx);
168
169 while (skb != NULL) {
170 arp_reply(skb);
171 skb = skb_dequeue(&npi->arp_tx);
172 }
173 }
174
175 void netpoll_poll(struct netpoll *np)
176 {
177 if (!np->dev || !netif_running(np->dev) || !np->dev->poll_controller)
178 return;
179
180 /* Process pending work on NIC */
181 np->dev->poll_controller(np->dev);
182 if (!list_empty(&np->dev->napi_list))
183 poll_napi(np);
184
185 service_arp_queue(np->dev->npinfo);
186
187 zap_completion_queue();
188 }
189
190 static void refill_skbs(void)
191 {
192 struct sk_buff *skb;
193 unsigned long flags;
194
195 spin_lock_irqsave(&skb_pool.lock, flags);
196 while (skb_pool.qlen < MAX_SKBS) {
197 skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC);
198 if (!skb)
199 break;
200
201 __skb_queue_tail(&skb_pool, skb);
202 }
203 spin_unlock_irqrestore(&skb_pool.lock, flags);
204 }
205
206 static void zap_completion_queue(void)
207 {
208 unsigned long flags;
209 struct softnet_data *sd = &get_cpu_var(softnet_data);
210
211 if (sd->completion_queue) {
212 struct sk_buff *clist;
213
214 local_irq_save(flags);
215 clist = sd->completion_queue;
216 sd->completion_queue = NULL;
217 local_irq_restore(flags);
218
219 while (clist != NULL) {
220 struct sk_buff *skb = clist;
221 clist = clist->next;
222 if (skb->destructor)
223 dev_kfree_skb_any(skb); /* put this one back */
224 else
225 __kfree_skb(skb);
226 }
227 }
228
229 put_cpu_var(softnet_data);
230 }
231
232 static struct sk_buff *find_skb(struct netpoll *np, int len, int reserve)
233 {
234 int count = 0;
235 struct sk_buff *skb;
236
237 zap_completion_queue();
238 refill_skbs();
239 repeat:
240
241 skb = alloc_skb(len, GFP_ATOMIC);
242 if (!skb)
243 skb = skb_dequeue(&skb_pool);
244
245 if (!skb) {
246 if (++count < 10) {
247 netpoll_poll(np);
248 goto repeat;
249 }
250 return NULL;
251 }
252
253 atomic_set(&skb->users, 1);
254 skb_reserve(skb, reserve);
255 return skb;
256 }
257
258 static int netpoll_owner_active(struct net_device *dev)
259 {
260 struct napi_struct *napi;
261
262 list_for_each_entry(napi, &dev->napi_list, dev_list) {
263 if (napi->poll_owner == smp_processor_id())
264 return 1;
265 }
266 return 0;
267 }
268
269 static void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
270 {
271 int status = NETDEV_TX_BUSY;
272 unsigned long tries;
273 struct net_device *dev = np->dev;
274 struct netpoll_info *npinfo = np->dev->npinfo;
275
276 if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) {
277 __kfree_skb(skb);
278 return;
279 }
280
281 /* don't get messages out of order, and no recursion */
282 if (skb_queue_len(&npinfo->txq) == 0 && !netpoll_owner_active(dev)) {
283 unsigned long flags;
284
285 local_irq_save(flags);
286 /* try until next clock tick */
287 for (tries = jiffies_to_usecs(1)/USEC_PER_POLL;
288 tries > 0; --tries) {
289 if (netif_tx_trylock(dev)) {
290 if (!netif_queue_stopped(dev) &&
291 !netif_subqueue_stopped(dev, skb))
292 status = dev->hard_start_xmit(skb, dev);
293 netif_tx_unlock(dev);
294
295 if (status == NETDEV_TX_OK)
296 break;
297
298 }
299
300 /* tickle device maybe there is some cleanup */
301 netpoll_poll(np);
302
303 udelay(USEC_PER_POLL);
304 }
305 local_irq_restore(flags);
306 }
307
308 if (status != NETDEV_TX_OK) {
309 skb_queue_tail(&npinfo->txq, skb);
310 schedule_delayed_work(&npinfo->tx_work,0);
311 }
312 }
313
314 void netpoll_send_udp(struct netpoll *np, const char *msg, int len)
315 {
316 int total_len, eth_len, ip_len, udp_len;
317 struct sk_buff *skb;
318 struct udphdr *udph;
319 struct iphdr *iph;
320 struct ethhdr *eth;
321
322 udp_len = len + sizeof(*udph);
323 ip_len = eth_len = udp_len + sizeof(*iph);
324 total_len = eth_len + ETH_HLEN + NET_IP_ALIGN;
325
326 skb = find_skb(np, total_len, total_len - len);
327 if (!skb)
328 return;
329
330 skb_copy_to_linear_data(skb, msg, len);
331 skb->len += len;
332
333 skb_push(skb, sizeof(*udph));
334 skb_reset_transport_header(skb);
335 udph = udp_hdr(skb);
336 udph->source = htons(np->local_port);
337 udph->dest = htons(np->remote_port);
338 udph->len = htons(udp_len);
339 udph->check = 0;
340 udph->check = csum_tcpudp_magic(htonl(np->local_ip),
341 htonl(np->remote_ip),
342 udp_len, IPPROTO_UDP,
343 csum_partial((unsigned char *)udph, udp_len, 0));
344 if (udph->check == 0)
345 udph->check = CSUM_MANGLED_0;
346
347 skb_push(skb, sizeof(*iph));
348 skb_reset_network_header(skb);
349 iph = ip_hdr(skb);
350
351 /* iph->version = 4; iph->ihl = 5; */
352 put_unaligned(0x45, (unsigned char *)iph);
353 iph->tos = 0;
354 put_unaligned(htons(ip_len), &(iph->tot_len));
355 iph->id = 0;
356 iph->frag_off = 0;
357 iph->ttl = 64;
358 iph->protocol = IPPROTO_UDP;
359 iph->check = 0;
360 put_unaligned(htonl(np->local_ip), &(iph->saddr));
361 put_unaligned(htonl(np->remote_ip), &(iph->daddr));
362 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl);
363
364 eth = (struct ethhdr *) skb_push(skb, ETH_HLEN);
365 skb_reset_mac_header(skb);
366 skb->protocol = eth->h_proto = htons(ETH_P_IP);
367 memcpy(eth->h_source, np->local_mac, 6);
368 memcpy(eth->h_dest, np->remote_mac, 6);
369
370 skb->dev = np->dev;
371
372 netpoll_send_skb(np, skb);
373 }
374
375 static void arp_reply(struct sk_buff *skb)
376 {
377 struct netpoll_info *npinfo = skb->dev->npinfo;
378 struct arphdr *arp;
379 unsigned char *arp_ptr;
380 int size, type = ARPOP_REPLY, ptype = ETH_P_ARP;
381 __be32 sip, tip;
382 unsigned char *sha;
383 struct sk_buff *send_skb;
384 struct netpoll *np = NULL;
385
386 if (npinfo->rx_np && npinfo->rx_np->dev == skb->dev)
387 np = npinfo->rx_np;
388 if (!np)
389 return;
390
391 /* No arp on this interface */
392 if (skb->dev->flags & IFF_NOARP)
393 return;
394
395 if (!pskb_may_pull(skb, (sizeof(struct arphdr) +
396 (2 * skb->dev->addr_len) +
397 (2 * sizeof(u32)))))
398 return;
399
400 skb_reset_network_header(skb);
401 skb_reset_transport_header(skb);
402 arp = arp_hdr(skb);
403
404 if ((arp->ar_hrd != htons(ARPHRD_ETHER) &&
405 arp->ar_hrd != htons(ARPHRD_IEEE802)) ||
406 arp->ar_pro != htons(ETH_P_IP) ||
407 arp->ar_op != htons(ARPOP_REQUEST))
408 return;
409
410 arp_ptr = (unsigned char *)(arp+1);
411 /* save the location of the src hw addr */
412 sha = arp_ptr;
413 arp_ptr += skb->dev->addr_len;
414 memcpy(&sip, arp_ptr, 4);
415 arp_ptr += 4;
416 /* if we actually cared about dst hw addr, it would get copied here */
417 arp_ptr += skb->dev->addr_len;
418 memcpy(&tip, arp_ptr, 4);
419
420 /* Should we ignore arp? */
421 if (tip != htonl(np->local_ip) || LOOPBACK(tip) || MULTICAST(tip))
422 return;
423
424 size = sizeof(struct arphdr) + 2 * (skb->dev->addr_len + 4);
425 send_skb = find_skb(np, size + LL_RESERVED_SPACE(np->dev),
426 LL_RESERVED_SPACE(np->dev));
427
428 if (!send_skb)
429 return;
430
431 skb_reset_network_header(send_skb);
432 arp = (struct arphdr *) skb_put(send_skb, size);
433 send_skb->dev = skb->dev;
434 send_skb->protocol = htons(ETH_P_ARP);
435
436 /* Fill the device header for the ARP frame */
437 if (dev_hard_header(send_skb, skb->dev, ptype,
438 sha, np->local_mac,
439 send_skb->len) < 0) {
440 kfree_skb(send_skb);
441 return;
442 }
443
444 /*
445 * Fill out the arp protocol part.
446 *
447 * we only support ethernet device type,
448 * which (according to RFC 1390) should always equal 1 (Ethernet).
449 */
450
451 arp->ar_hrd = htons(np->dev->type);
452 arp->ar_pro = htons(ETH_P_IP);
453 arp->ar_hln = np->dev->addr_len;
454 arp->ar_pln = 4;
455 arp->ar_op = htons(type);
456
457 arp_ptr=(unsigned char *)(arp + 1);
458 memcpy(arp_ptr, np->dev->dev_addr, np->dev->addr_len);
459 arp_ptr += np->dev->addr_len;
460 memcpy(arp_ptr, &tip, 4);
461 arp_ptr += 4;
462 memcpy(arp_ptr, sha, np->dev->addr_len);
463 arp_ptr += np->dev->addr_len;
464 memcpy(arp_ptr, &sip, 4);
465
466 netpoll_send_skb(np, send_skb);
467 }
468
469 int __netpoll_rx(struct sk_buff *skb)
470 {
471 int proto, len, ulen;
472 struct iphdr *iph;
473 struct udphdr *uh;
474 struct netpoll_info *npi = skb->dev->npinfo;
475 struct netpoll *np = npi->rx_np;
476
477 if (!np)
478 goto out;
479 if (skb->dev->type != ARPHRD_ETHER)
480 goto out;
481
482 /* check if netpoll clients need ARP */
483 if (skb->protocol == htons(ETH_P_ARP) &&
484 atomic_read(&trapped)) {
485 skb_queue_tail(&npi->arp_tx, skb);
486 return 1;
487 }
488
489 proto = ntohs(eth_hdr(skb)->h_proto);
490 if (proto != ETH_P_IP)
491 goto out;
492 if (skb->pkt_type == PACKET_OTHERHOST)
493 goto out;
494 if (skb_shared(skb))
495 goto out;
496
497 iph = (struct iphdr *)skb->data;
498 if (!pskb_may_pull(skb, sizeof(struct iphdr)))
499 goto out;
500 if (iph->ihl < 5 || iph->version != 4)
501 goto out;
502 if (!pskb_may_pull(skb, iph->ihl*4))
503 goto out;
504 if (ip_fast_csum((u8 *)iph, iph->ihl) != 0)
505 goto out;
506
507 len = ntohs(iph->tot_len);
508 if (skb->len < len || len < iph->ihl*4)
509 goto out;
510
511 /*
512 * Our transport medium may have padded the buffer out.
513 * Now We trim to the true length of the frame.
514 */
515 if (pskb_trim_rcsum(skb, len))
516 goto out;
517
518 if (iph->protocol != IPPROTO_UDP)
519 goto out;
520
521 len -= iph->ihl*4;
522 uh = (struct udphdr *)(((char *)iph) + iph->ihl*4);
523 ulen = ntohs(uh->len);
524
525 if (ulen != len)
526 goto out;
527 if (checksum_udp(skb, uh, ulen, iph->saddr, iph->daddr))
528 goto out;
529 if (np->local_ip && np->local_ip != ntohl(iph->daddr))
530 goto out;
531 if (np->remote_ip && np->remote_ip != ntohl(iph->saddr))
532 goto out;
533 if (np->local_port && np->local_port != ntohs(uh->dest))
534 goto out;
535
536 np->rx_hook(np, ntohs(uh->source),
537 (char *)(uh+1),
538 ulen - sizeof(struct udphdr));
539
540 kfree_skb(skb);
541 return 1;
542
543 out:
544 if (atomic_read(&trapped)) {
545 kfree_skb(skb);
546 return 1;
547 }
548
549 return 0;
550 }
551
552 void netpoll_print_options(struct netpoll *np)
553 {
554 DECLARE_MAC_BUF(mac);
555 printk(KERN_INFO "%s: local port %d\n",
556 np->name, np->local_port);
557 printk(KERN_INFO "%s: local IP %d.%d.%d.%d\n",
558 np->name, HIPQUAD(np->local_ip));
559 printk(KERN_INFO "%s: interface %s\n",
560 np->name, np->dev_name);
561 printk(KERN_INFO "%s: remote port %d\n",
562 np->name, np->remote_port);
563 printk(KERN_INFO "%s: remote IP %d.%d.%d.%d\n",
564 np->name, HIPQUAD(np->remote_ip));
565 printk(KERN_INFO "%s: remote ethernet address %s\n",
566 np->name, print_mac(mac, np->remote_mac));
567 }
568
569 int netpoll_parse_options(struct netpoll *np, char *opt)
570 {
571 char *cur=opt, *delim;
572
573 if (*cur != '@') {
574 if ((delim = strchr(cur, '@')) == NULL)
575 goto parse_failed;
576 *delim = 0;
577 np->local_port = simple_strtol(cur, NULL, 10);
578 cur = delim;
579 }
580 cur++;
581
582 if (*cur != '/') {
583 if ((delim = strchr(cur, '/')) == NULL)
584 goto parse_failed;
585 *delim = 0;
586 np->local_ip = ntohl(in_aton(cur));
587 cur = delim;
588 }
589 cur++;
590
591 if (*cur != ',') {
592 /* parse out dev name */
593 if ((delim = strchr(cur, ',')) == NULL)
594 goto parse_failed;
595 *delim = 0;
596 strlcpy(np->dev_name, cur, sizeof(np->dev_name));
597 cur = delim;
598 }
599 cur++;
600
601 if (*cur != '@') {
602 /* dst port */
603 if ((delim = strchr(cur, '@')) == NULL)
604 goto parse_failed;
605 *delim = 0;
606 np->remote_port = simple_strtol(cur, NULL, 10);
607 cur = delim;
608 }
609 cur++;
610
611 /* dst ip */
612 if ((delim = strchr(cur, '/')) == NULL)
613 goto parse_failed;
614 *delim = 0;
615 np->remote_ip = ntohl(in_aton(cur));
616 cur = delim + 1;
617
618 if (*cur != 0) {
619 /* MAC address */
620 if ((delim = strchr(cur, ':')) == NULL)
621 goto parse_failed;
622 *delim = 0;
623 np->remote_mac[0] = simple_strtol(cur, NULL, 16);
624 cur = delim + 1;
625 if ((delim = strchr(cur, ':')) == NULL)
626 goto parse_failed;
627 *delim = 0;
628 np->remote_mac[1] = simple_strtol(cur, NULL, 16);
629 cur = delim + 1;
630 if ((delim = strchr(cur, ':')) == NULL)
631 goto parse_failed;
632 *delim = 0;
633 np->remote_mac[2] = simple_strtol(cur, NULL, 16);
634 cur = delim + 1;
635 if ((delim = strchr(cur, ':')) == NULL)
636 goto parse_failed;
637 *delim = 0;
638 np->remote_mac[3] = 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[4] = simple_strtol(cur, NULL, 16);
644 cur = delim + 1;
645 np->remote_mac[5] = simple_strtol(cur, NULL, 16);
646 }
647
648 netpoll_print_options(np);
649
650 return 0;
651
652 parse_failed:
653 printk(KERN_INFO "%s: couldn't parse config at %s!\n",
654 np->name, cur);
655 return -1;
656 }
657
658 int netpoll_setup(struct netpoll *np)
659 {
660 struct net_device *ndev = NULL;
661 struct in_device *in_dev;
662 struct netpoll_info *npinfo;
663 unsigned long flags;
664 int err;
665
666 if (np->dev_name)
667 ndev = dev_get_by_name(&init_net, np->dev_name);
668 if (!ndev) {
669 printk(KERN_ERR "%s: %s doesn't exist, aborting.\n",
670 np->name, np->dev_name);
671 return -ENODEV;
672 }
673
674 np->dev = ndev;
675 if (!ndev->npinfo) {
676 npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL);
677 if (!npinfo) {
678 err = -ENOMEM;
679 goto release;
680 }
681
682 npinfo->rx_flags = 0;
683 npinfo->rx_np = NULL;
684
685 spin_lock_init(&npinfo->rx_lock);
686 skb_queue_head_init(&npinfo->arp_tx);
687 skb_queue_head_init(&npinfo->txq);
688 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process);
689
690 atomic_set(&npinfo->refcnt, 1);
691 } else {
692 npinfo = ndev->npinfo;
693 atomic_inc(&npinfo->refcnt);
694 }
695
696 if (!ndev->poll_controller) {
697 printk(KERN_ERR "%s: %s doesn't support polling, aborting.\n",
698 np->name, np->dev_name);
699 err = -ENOTSUPP;
700 goto release;
701 }
702
703 if (!netif_running(ndev)) {
704 unsigned long atmost, atleast;
705
706 printk(KERN_INFO "%s: device %s not up yet, forcing it\n",
707 np->name, np->dev_name);
708
709 rtnl_lock();
710 err = dev_open(ndev);
711 rtnl_unlock();
712
713 if (err) {
714 printk(KERN_ERR "%s: failed to open %s\n",
715 np->name, ndev->name);
716 goto release;
717 }
718
719 atleast = jiffies + HZ/10;
720 atmost = jiffies + 4*HZ;
721 while (!netif_carrier_ok(ndev)) {
722 if (time_after(jiffies, atmost)) {
723 printk(KERN_NOTICE
724 "%s: timeout waiting for carrier\n",
725 np->name);
726 break;
727 }
728 cond_resched();
729 }
730
731 /* If carrier appears to come up instantly, we don't
732 * trust it and pause so that we don't pump all our
733 * queued console messages into the bitbucket.
734 */
735
736 if (time_before(jiffies, atleast)) {
737 printk(KERN_NOTICE "%s: carrier detect appears"
738 " untrustworthy, waiting 4 seconds\n",
739 np->name);
740 msleep(4000);
741 }
742 }
743
744 if (is_zero_ether_addr(np->local_mac) && ndev->dev_addr)
745 memcpy(np->local_mac, ndev->dev_addr, 6);
746
747 if (!np->local_ip) {
748 rcu_read_lock();
749 in_dev = __in_dev_get_rcu(ndev);
750
751 if (!in_dev || !in_dev->ifa_list) {
752 rcu_read_unlock();
753 printk(KERN_ERR "%s: no IP address for %s, aborting\n",
754 np->name, np->dev_name);
755 err = -EDESTADDRREQ;
756 goto release;
757 }
758
759 np->local_ip = ntohl(in_dev->ifa_list->ifa_local);
760 rcu_read_unlock();
761 printk(KERN_INFO "%s: local IP %d.%d.%d.%d\n",
762 np->name, HIPQUAD(np->local_ip));
763 }
764
765 if (np->rx_hook) {
766 spin_lock_irqsave(&npinfo->rx_lock, flags);
767 npinfo->rx_flags |= NETPOLL_RX_ENABLED;
768 npinfo->rx_np = np;
769 spin_unlock_irqrestore(&npinfo->rx_lock, flags);
770 }
771
772 /* fill up the skb queue */
773 refill_skbs();
774
775 /* last thing to do is link it to the net device structure */
776 ndev->npinfo = npinfo;
777
778 /* avoid racing with NAPI reading npinfo */
779 synchronize_rcu();
780
781 return 0;
782
783 release:
784 if (!ndev->npinfo)
785 kfree(npinfo);
786 np->dev = NULL;
787 dev_put(ndev);
788 return err;
789 }
790
791 static int __init netpoll_init(void)
792 {
793 skb_queue_head_init(&skb_pool);
794 return 0;
795 }
796 core_initcall(netpoll_init);
797
798 void netpoll_cleanup(struct netpoll *np)
799 {
800 struct netpoll_info *npinfo;
801 unsigned long flags;
802
803 if (np->dev) {
804 npinfo = np->dev->npinfo;
805 if (npinfo) {
806 if (npinfo->rx_np == np) {
807 spin_lock_irqsave(&npinfo->rx_lock, flags);
808 npinfo->rx_np = NULL;
809 npinfo->rx_flags &= ~NETPOLL_RX_ENABLED;
810 spin_unlock_irqrestore(&npinfo->rx_lock, flags);
811 }
812
813 if (atomic_dec_and_test(&npinfo->refcnt)) {
814 skb_queue_purge(&npinfo->arp_tx);
815 skb_queue_purge(&npinfo->txq);
816 cancel_rearming_delayed_work(&npinfo->tx_work);
817
818 /* clean after last, unfinished work */
819 if (!skb_queue_empty(&npinfo->txq)) {
820 struct sk_buff *skb;
821 skb = __skb_dequeue(&npinfo->txq);
822 kfree_skb(skb);
823 }
824 kfree(npinfo);
825 np->dev->npinfo = NULL;
826 }
827 }
828
829 dev_put(np->dev);
830 }
831
832 np->dev = NULL;
833 }
834
835 int netpoll_trap(void)
836 {
837 return atomic_read(&trapped);
838 }
839
840 void netpoll_set_trap(int trap)
841 {
842 if (trap)
843 atomic_inc(&trapped);
844 else
845 atomic_dec(&trapped);
846 }
847
848 EXPORT_SYMBOL(netpoll_set_trap);
849 EXPORT_SYMBOL(netpoll_trap);
850 EXPORT_SYMBOL(netpoll_print_options);
851 EXPORT_SYMBOL(netpoll_parse_options);
852 EXPORT_SYMBOL(netpoll_setup);
853 EXPORT_SYMBOL(netpoll_cleanup);
854 EXPORT_SYMBOL(netpoll_send_udp);
855 EXPORT_SYMBOL(netpoll_poll);
WRT350N Kernel Patches