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sysctl: ipv6 route flushing (kill binary path)
[wrt350n-kernel.git] / net / core / netpoll.c
blob95daba6249676dc8e466303279cadc1223e57d81
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->queue_mapping)) ||
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 void poll_napi(struct netpoll *np)
120 {
121 struct netpoll_info *npinfo = np->dev->npinfo;
122 struct napi_struct *napi;
123 int budget = 16;
124
125 list_for_each_entry(napi, &np->dev->napi_list, dev_list) {
126 if (test_bit(NAPI_STATE_SCHED, &napi->state) &&
127 napi->poll_owner != smp_processor_id() &&
128 spin_trylock(&napi->poll_lock)) {
129 npinfo->rx_flags |= NETPOLL_RX_DROP;
130 atomic_inc(&trapped);
131
132 napi->poll(napi, budget);
133
134 atomic_dec(&trapped);
135 npinfo->rx_flags &= ~NETPOLL_RX_DROP;
136 spin_unlock(&napi->poll_lock);
137 }
138 }
139 }
140
141 static void service_arp_queue(struct netpoll_info *npi)
142 {
143 struct sk_buff *skb;
144
145 if (unlikely(!npi))
146 return;
147
148 skb = skb_dequeue(&npi->arp_tx);
149
150 while (skb != NULL) {
151 arp_reply(skb);
152 skb = skb_dequeue(&npi->arp_tx);
153 }
154 }
155
156 void netpoll_poll(struct netpoll *np)
157 {
158 if (!np->dev || !netif_running(np->dev) || !np->dev->poll_controller)
159 return;
160
161 /* Process pending work on NIC */
162 np->dev->poll_controller(np->dev);
163 if (!list_empty(&np->dev->napi_list))
164 poll_napi(np);
165
166 service_arp_queue(np->dev->npinfo);
167
168 zap_completion_queue();
169 }
170
171 static void refill_skbs(void)
172 {
173 struct sk_buff *skb;
174 unsigned long flags;
175
176 spin_lock_irqsave(&skb_pool.lock, flags);
177 while (skb_pool.qlen < MAX_SKBS) {
178 skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC);
179 if (!skb)
180 break;
181
182 __skb_queue_tail(&skb_pool, skb);
183 }
184 spin_unlock_irqrestore(&skb_pool.lock, flags);
185 }
186
187 static void zap_completion_queue(void)
188 {
189 unsigned long flags;
190 struct softnet_data *sd = &get_cpu_var(softnet_data);
191
192 if (sd->completion_queue) {
193 struct sk_buff *clist;
194
195 local_irq_save(flags);
196 clist = sd->completion_queue;
197 sd->completion_queue = NULL;
198 local_irq_restore(flags);
199
200 while (clist != NULL) {
201 struct sk_buff *skb = clist;
202 clist = clist->next;
203 if (skb->destructor)
204 dev_kfree_skb_any(skb); /* put this one back */
205 else
206 __kfree_skb(skb);
207 }
208 }
209
210 put_cpu_var(softnet_data);
211 }
212
213 static struct sk_buff *find_skb(struct netpoll *np, int len, int reserve)
214 {
215 int count = 0;
216 struct sk_buff *skb;
217
218 zap_completion_queue();
219 refill_skbs();
220 repeat:
221
222 skb = alloc_skb(len, GFP_ATOMIC);
223 if (!skb)
224 skb = skb_dequeue(&skb_pool);
225
226 if (!skb) {
227 if (++count < 10) {
228 netpoll_poll(np);
229 goto repeat;
230 }
231 return NULL;
232 }
233
234 atomic_set(&skb->users, 1);
235 skb_reserve(skb, reserve);
236 return skb;
237 }
238
239 static int netpoll_owner_active(struct net_device *dev)
240 {
241 struct napi_struct *napi;
242
243 list_for_each_entry(napi, &dev->napi_list, dev_list) {
244 if (napi->poll_owner == smp_processor_id())
245 return 1;
246 }
247 return 0;
248 }
249
250 static void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
251 {
252 int status = NETDEV_TX_BUSY;
253 unsigned long tries;
254 struct net_device *dev = np->dev;
255 struct netpoll_info *npinfo = np->dev->npinfo;
256
257 if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) {
258 __kfree_skb(skb);
259 return;
260 }
261
262 /* don't get messages out of order, and no recursion */
263 if (skb_queue_len(&npinfo->txq) == 0 && !netpoll_owner_active(dev)) {
264 unsigned long flags;
265
266 local_irq_save(flags);
267 /* try until next clock tick */
268 for (tries = jiffies_to_usecs(1)/USEC_PER_POLL;
269 tries > 0; --tries) {
270 if (netif_tx_trylock(dev)) {
271 if (!netif_queue_stopped(dev) &&
272 !netif_subqueue_stopped(dev, skb->queue_mapping))
273 status = dev->hard_start_xmit(skb, dev);
274 netif_tx_unlock(dev);
275
276 if (status == NETDEV_TX_OK)
277 break;
278
279 }
280
281 /* tickle device maybe there is some cleanup */
282 netpoll_poll(np);
283
284 udelay(USEC_PER_POLL);
285 }
286 local_irq_restore(flags);
287 }
288
289 if (status != NETDEV_TX_OK) {
290 skb_queue_tail(&npinfo->txq, skb);
291 schedule_delayed_work(&npinfo->tx_work,0);
292 }
293 }
294
295 void netpoll_send_udp(struct netpoll *np, const char *msg, int len)
296 {
297 int total_len, eth_len, ip_len, udp_len;
298 struct sk_buff *skb;
299 struct udphdr *udph;
300 struct iphdr *iph;
301 struct ethhdr *eth;
302
303 udp_len = len + sizeof(*udph);
304 ip_len = eth_len = udp_len + sizeof(*iph);
305 total_len = eth_len + ETH_HLEN + NET_IP_ALIGN;
306
307 skb = find_skb(np, total_len, total_len - len);
308 if (!skb)
309 return;
310
311 skb_copy_to_linear_data(skb, msg, len);
312 skb->len += len;
313
314 skb_push(skb, sizeof(*udph));
315 skb_reset_transport_header(skb);
316 udph = udp_hdr(skb);
317 udph->source = htons(np->local_port);
318 udph->dest = htons(np->remote_port);
319 udph->len = htons(udp_len);
320 udph->check = 0;
321 udph->check = csum_tcpudp_magic(htonl(np->local_ip),
322 htonl(np->remote_ip),
323 udp_len, IPPROTO_UDP,
324 csum_partial((unsigned char *)udph, udp_len, 0));
325 if (udph->check == 0)
326 udph->check = CSUM_MANGLED_0;
327
328 skb_push(skb, sizeof(*iph));
329 skb_reset_network_header(skb);
330 iph = ip_hdr(skb);
331
332 /* iph->version = 4; iph->ihl = 5; */
333 put_unaligned(0x45, (unsigned char *)iph);
334 iph->tos = 0;
335 put_unaligned(htons(ip_len), &(iph->tot_len));
336 iph->id = 0;
337 iph->frag_off = 0;
338 iph->ttl = 64;
339 iph->protocol = IPPROTO_UDP;
340 iph->check = 0;
341 put_unaligned(htonl(np->local_ip), &(iph->saddr));
342 put_unaligned(htonl(np->remote_ip), &(iph->daddr));
343 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl);
344
345 eth = (struct ethhdr *) skb_push(skb, ETH_HLEN);
346 skb_reset_mac_header(skb);
347 skb->protocol = eth->h_proto = htons(ETH_P_IP);
348 memcpy(eth->h_source, np->local_mac, 6);
349 memcpy(eth->h_dest, np->remote_mac, 6);
350
351 skb->dev = np->dev;
352
353 netpoll_send_skb(np, skb);
354 }
355
356 static void arp_reply(struct sk_buff *skb)
357 {
358 struct netpoll_info *npinfo = skb->dev->npinfo;
359 struct arphdr *arp;
360 unsigned char *arp_ptr;
361 int size, type = ARPOP_REPLY, ptype = ETH_P_ARP;
362 __be32 sip, tip;
363 unsigned char *sha;
364 struct sk_buff *send_skb;
365 struct netpoll *np = NULL;
366
367 if (npinfo->rx_np && npinfo->rx_np->dev == skb->dev)
368 np = npinfo->rx_np;
369 if (!np)
370 return;
371
372 /* No arp on this interface */
373 if (skb->dev->flags & IFF_NOARP)
374 return;
375
376 if (!pskb_may_pull(skb, (sizeof(struct arphdr) +
377 (2 * skb->dev->addr_len) +
378 (2 * sizeof(u32)))))
379 return;
380
381 skb_reset_network_header(skb);
382 skb_reset_transport_header(skb);
383 arp = arp_hdr(skb);
384
385 if ((arp->ar_hrd != htons(ARPHRD_ETHER) &&
386 arp->ar_hrd != htons(ARPHRD_IEEE802)) ||
387 arp->ar_pro != htons(ETH_P_IP) ||
388 arp->ar_op != htons(ARPOP_REQUEST))
389 return;
390
391 arp_ptr = (unsigned char *)(arp+1);
392 /* save the location of the src hw addr */
393 sha = arp_ptr;
394 arp_ptr += skb->dev->addr_len;
395 memcpy(&sip, arp_ptr, 4);
396 arp_ptr += 4;
397 /* if we actually cared about dst hw addr, it would get copied here */
398 arp_ptr += skb->dev->addr_len;
399 memcpy(&tip, arp_ptr, 4);
400
401 /* Should we ignore arp? */
402 if (tip != htonl(np->local_ip) || LOOPBACK(tip) || MULTICAST(tip))
403 return;
404
405 size = sizeof(struct arphdr) + 2 * (skb->dev->addr_len + 4);
406 send_skb = find_skb(np, size + LL_RESERVED_SPACE(np->dev),
407 LL_RESERVED_SPACE(np->dev));
408
409 if (!send_skb)
410 return;
411
412 skb_reset_network_header(send_skb);
413 arp = (struct arphdr *) skb_put(send_skb, size);
414 send_skb->dev = skb->dev;
415 send_skb->protocol = htons(ETH_P_ARP);
416
417 /* Fill the device header for the ARP frame */
418 if (dev_hard_header(send_skb, skb->dev, ptype,
419 sha, np->local_mac,
420 send_skb->len) < 0) {
421 kfree_skb(send_skb);
422 return;
423 }
424
425 /*
426 * Fill out the arp protocol part.
427 *
428 * we only support ethernet device type,
429 * which (according to RFC 1390) should always equal 1 (Ethernet).
430 */
431
432 arp->ar_hrd = htons(np->dev->type);
433 arp->ar_pro = htons(ETH_P_IP);
434 arp->ar_hln = np->dev->addr_len;
435 arp->ar_pln = 4;
436 arp->ar_op = htons(type);
437
438 arp_ptr=(unsigned char *)(arp + 1);
439 memcpy(arp_ptr, np->dev->dev_addr, np->dev->addr_len);
440 arp_ptr += np->dev->addr_len;
441 memcpy(arp_ptr, &tip, 4);
442 arp_ptr += 4;
443 memcpy(arp_ptr, sha, np->dev->addr_len);
444 arp_ptr += np->dev->addr_len;
445 memcpy(arp_ptr, &sip, 4);
446
447 netpoll_send_skb(np, send_skb);
448 }
449
450 int __netpoll_rx(struct sk_buff *skb)
451 {
452 int proto, len, ulen;
453 struct iphdr *iph;
454 struct udphdr *uh;
455 struct netpoll_info *npi = skb->dev->npinfo;
456 struct netpoll *np = npi->rx_np;
457
458 if (!np)
459 goto out;
460 if (skb->dev->type != ARPHRD_ETHER)
461 goto out;
462
463 /* check if netpoll clients need ARP */
464 if (skb->protocol == htons(ETH_P_ARP) &&
465 atomic_read(&trapped)) {
466 skb_queue_tail(&npi->arp_tx, skb);
467 return 1;
468 }
469
470 proto = ntohs(eth_hdr(skb)->h_proto);
471 if (proto != ETH_P_IP)
472 goto out;
473 if (skb->pkt_type == PACKET_OTHERHOST)
474 goto out;
475 if (skb_shared(skb))
476 goto out;
477
478 iph = (struct iphdr *)skb->data;
479 if (!pskb_may_pull(skb, sizeof(struct iphdr)))
480 goto out;
481 if (iph->ihl < 5 || iph->version != 4)
482 goto out;
483 if (!pskb_may_pull(skb, iph->ihl*4))
484 goto out;
485 if (ip_fast_csum((u8 *)iph, iph->ihl) != 0)
486 goto out;
487
488 len = ntohs(iph->tot_len);
489 if (skb->len < len || len < iph->ihl*4)
490 goto out;
491
492 /*
493 * Our transport medium may have padded the buffer out.
494 * Now We trim to the true length of the frame.
495 */
496 if (pskb_trim_rcsum(skb, len))
497 goto out;
498
499 if (iph->protocol != IPPROTO_UDP)
500 goto out;
501
502 len -= iph->ihl*4;
503 uh = (struct udphdr *)(((char *)iph) + iph->ihl*4);
504 ulen = ntohs(uh->len);
505
506 if (ulen != len)
507 goto out;
508 if (checksum_udp(skb, uh, ulen, iph->saddr, iph->daddr))
509 goto out;
510 if (np->local_ip && np->local_ip != ntohl(iph->daddr))
511 goto out;
512 if (np->remote_ip && np->remote_ip != ntohl(iph->saddr))
513 goto out;
514 if (np->local_port && np->local_port != ntohs(uh->dest))
515 goto out;
516
517 np->rx_hook(np, ntohs(uh->source),
518 (char *)(uh+1),
519 ulen - sizeof(struct udphdr));
520
521 kfree_skb(skb);
522 return 1;
523
524 out:
525 if (atomic_read(&trapped)) {
526 kfree_skb(skb);
527 return 1;
528 }
529
530 return 0;
531 }
532
533 void netpoll_print_options(struct netpoll *np)
534 {
535 DECLARE_MAC_BUF(mac);
536 printk(KERN_INFO "%s: local port %d\n",
537 np->name, np->local_port);
538 printk(KERN_INFO "%s: local IP %d.%d.%d.%d\n",
539 np->name, HIPQUAD(np->local_ip));
540 printk(KERN_INFO "%s: interface %s\n",
541 np->name, np->dev_name);
542 printk(KERN_INFO "%s: remote port %d\n",
543 np->name, np->remote_port);
544 printk(KERN_INFO "%s: remote IP %d.%d.%d.%d\n",
545 np->name, HIPQUAD(np->remote_ip));
546 printk(KERN_INFO "%s: remote ethernet address %s\n",
547 np->name, print_mac(mac, np->remote_mac));
548 }
549
550 int netpoll_parse_options(struct netpoll *np, char *opt)
551 {
552 char *cur=opt, *delim;
553
554 if (*cur != '@') {
555 if ((delim = strchr(cur, '@')) == NULL)
556 goto parse_failed;
557 *delim = 0;
558 np->local_port = simple_strtol(cur, NULL, 10);
559 cur = delim;
560 }
561 cur++;
562
563 if (*cur != '/') {
564 if ((delim = strchr(cur, '/')) == NULL)
565 goto parse_failed;
566 *delim = 0;
567 np->local_ip = ntohl(in_aton(cur));
568 cur = delim;
569 }
570 cur++;
571
572 if (*cur != ',') {
573 /* parse out dev name */
574 if ((delim = strchr(cur, ',')) == NULL)
575 goto parse_failed;
576 *delim = 0;
577 strlcpy(np->dev_name, cur, sizeof(np->dev_name));
578 cur = delim;
579 }
580 cur++;
581
582 if (*cur != '@') {
583 /* dst port */
584 if ((delim = strchr(cur, '@')) == NULL)
585 goto parse_failed;
586 *delim = 0;
587 np->remote_port = simple_strtol(cur, NULL, 10);
588 cur = delim;
589 }
590 cur++;
591
592 /* dst ip */
593 if ((delim = strchr(cur, '/')) == NULL)
594 goto parse_failed;
595 *delim = 0;
596 np->remote_ip = ntohl(in_aton(cur));
597 cur = delim + 1;
598
599 if (*cur != 0) {
600 /* MAC address */
601 if ((delim = strchr(cur, ':')) == NULL)
602 goto parse_failed;
603 *delim = 0;
604 np->remote_mac[0] = simple_strtol(cur, NULL, 16);
605 cur = delim + 1;
606 if ((delim = strchr(cur, ':')) == NULL)
607 goto parse_failed;
608 *delim = 0;
609 np->remote_mac[1] = simple_strtol(cur, NULL, 16);
610 cur = delim + 1;
611 if ((delim = strchr(cur, ':')) == NULL)
612 goto parse_failed;
613 *delim = 0;
614 np->remote_mac[2] = simple_strtol(cur, NULL, 16);
615 cur = delim + 1;
616 if ((delim = strchr(cur, ':')) == NULL)
617 goto parse_failed;
618 *delim = 0;
619 np->remote_mac[3] = simple_strtol(cur, NULL, 16);
620 cur = delim + 1;
621 if ((delim = strchr(cur, ':')) == NULL)
622 goto parse_failed;
623 *delim = 0;
624 np->remote_mac[4] = simple_strtol(cur, NULL, 16);
625 cur = delim + 1;
626 np->remote_mac[5] = simple_strtol(cur, NULL, 16);
627 }
628
629 netpoll_print_options(np);
630
631 return 0;
632
633 parse_failed:
634 printk(KERN_INFO "%s: couldn't parse config at %s!\n",
635 np->name, cur);
636 return -1;
637 }
638
639 int netpoll_setup(struct netpoll *np)
640 {
641 struct net_device *ndev = NULL;
642 struct in_device *in_dev;
643 struct netpoll_info *npinfo;
644 unsigned long flags;
645 int err;
646
647 if (np->dev_name)
648 ndev = dev_get_by_name(&init_net, np->dev_name);
649 if (!ndev) {
650 printk(KERN_ERR "%s: %s doesn't exist, aborting.\n",
651 np->name, np->dev_name);
652 return -ENODEV;
653 }
654
655 np->dev = ndev;
656 if (!ndev->npinfo) {
657 npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL);
658 if (!npinfo) {
659 err = -ENOMEM;
660 goto release;
661 }
662
663 npinfo->rx_flags = 0;
664 npinfo->rx_np = NULL;
665
666 spin_lock_init(&npinfo->rx_lock);
667 skb_queue_head_init(&npinfo->arp_tx);
668 skb_queue_head_init(&npinfo->txq);
669 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process);
670
671 atomic_set(&npinfo->refcnt, 1);
672 } else {
673 npinfo = ndev->npinfo;
674 atomic_inc(&npinfo->refcnt);
675 }
676
677 if (!ndev->poll_controller) {
678 printk(KERN_ERR "%s: %s doesn't support polling, aborting.\n",
679 np->name, np->dev_name);
680 err = -ENOTSUPP;
681 goto release;
682 }
683
684 if (!netif_running(ndev)) {
685 unsigned long atmost, atleast;
686
687 printk(KERN_INFO "%s: device %s not up yet, forcing it\n",
688 np->name, np->dev_name);
689
690 rtnl_lock();
691 err = dev_open(ndev);
692 rtnl_unlock();
693
694 if (err) {
695 printk(KERN_ERR "%s: failed to open %s\n",
696 np->name, ndev->name);
697 goto release;
698 }
699
700 atleast = jiffies + HZ/10;
701 atmost = jiffies + 4*HZ;
702 while (!netif_carrier_ok(ndev)) {
703 if (time_after(jiffies, atmost)) {
704 printk(KERN_NOTICE
705 "%s: timeout waiting for carrier\n",
706 np->name);
707 break;
708 }
709 cond_resched();
710 }
711
712 /* If carrier appears to come up instantly, we don't
713 * trust it and pause so that we don't pump all our
714 * queued console messages into the bitbucket.
715 */
716
717 if (time_before(jiffies, atleast)) {
718 printk(KERN_NOTICE "%s: carrier detect appears"
719 " untrustworthy, waiting 4 seconds\n",
720 np->name);
721 msleep(4000);
722 }
723 }
724
725 if (is_zero_ether_addr(np->local_mac) && ndev->dev_addr)
726 memcpy(np->local_mac, ndev->dev_addr, 6);
727
728 if (!np->local_ip) {
729 rcu_read_lock();
730 in_dev = __in_dev_get_rcu(ndev);
731
732 if (!in_dev || !in_dev->ifa_list) {
733 rcu_read_unlock();
734 printk(KERN_ERR "%s: no IP address for %s, aborting\n",
735 np->name, np->dev_name);
736 err = -EDESTADDRREQ;
737 goto release;
738 }
739
740 np->local_ip = ntohl(in_dev->ifa_list->ifa_local);
741 rcu_read_unlock();
742 printk(KERN_INFO "%s: local IP %d.%d.%d.%d\n",
743 np->name, HIPQUAD(np->local_ip));
744 }
745
746 if (np->rx_hook) {
747 spin_lock_irqsave(&npinfo->rx_lock, flags);
748 npinfo->rx_flags |= NETPOLL_RX_ENABLED;
749 npinfo->rx_np = np;
750 spin_unlock_irqrestore(&npinfo->rx_lock, flags);
751 }
752
753 /* fill up the skb queue */
754 refill_skbs();
755
756 /* last thing to do is link it to the net device structure */
757 ndev->npinfo = npinfo;
758
759 /* avoid racing with NAPI reading npinfo */
760 synchronize_rcu();
761
762 return 0;
763
764 release:
765 if (!ndev->npinfo)
766 kfree(npinfo);
767 np->dev = NULL;
768 dev_put(ndev);
769 return err;
770 }
771
772 static int __init netpoll_init(void)
773 {
774 skb_queue_head_init(&skb_pool);
775 return 0;
776 }
777 core_initcall(netpoll_init);
778
779 void netpoll_cleanup(struct netpoll *np)
780 {
781 struct netpoll_info *npinfo;
782 unsigned long flags;
783
784 if (np->dev) {
785 npinfo = np->dev->npinfo;
786 if (npinfo) {
787 if (npinfo->rx_np == np) {
788 spin_lock_irqsave(&npinfo->rx_lock, flags);
789 npinfo->rx_np = NULL;
790 npinfo->rx_flags &= ~NETPOLL_RX_ENABLED;
791 spin_unlock_irqrestore(&npinfo->rx_lock, flags);
792 }
793
794 if (atomic_dec_and_test(&npinfo->refcnt)) {
795 skb_queue_purge(&npinfo->arp_tx);
796 skb_queue_purge(&npinfo->txq);
797 cancel_rearming_delayed_work(&npinfo->tx_work);
798
799 /* clean after last, unfinished work */
800 if (!skb_queue_empty(&npinfo->txq)) {
801 struct sk_buff *skb;
802 skb = __skb_dequeue(&npinfo->txq);
803 kfree_skb(skb);
804 }
805 kfree(npinfo);
806 np->dev->npinfo = NULL;
807 }
808 }
809
810 dev_put(np->dev);
811 }
812
813 np->dev = NULL;
814 }
815
816 int netpoll_trap(void)
817 {
818 return atomic_read(&trapped);
819 }
820
821 void netpoll_set_trap(int trap)
822 {
823 if (trap)
824 atomic_inc(&trapped);
825 else
826 atomic_dec(&trapped);
827 }
828
829 EXPORT_SYMBOL(netpoll_set_trap);
830 EXPORT_SYMBOL(netpoll_trap);
831 EXPORT_SYMBOL(netpoll_print_options);
832 EXPORT_SYMBOL(netpoll_parse_options);
833 EXPORT_SYMBOL(netpoll_setup);
834 EXPORT_SYMBOL(netpoll_cleanup);
835 EXPORT_SYMBOL(netpoll_send_udp);
836 EXPORT_SYMBOL(netpoll_poll);
WRT350N Kernel Patches