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nl80211: allow enabling WoWLAN without triggers
[linux-2.6.git] / net / core / netpoll.c
blob3d84fb9d88739629b32c77f1a1d77c7f55ad7630
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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13
14 #include <linux/moduleparam.h>
15 #include <linux/netdevice.h>
16 #include <linux/etherdevice.h>
17 #include <linux/string.h>
18 #include <linux/if_arp.h>
19 #include <linux/inetdevice.h>
20 #include <linux/inet.h>
21 #include <linux/interrupt.h>
22 #include <linux/netpoll.h>
23 #include <linux/sched.h>
24 #include <linux/delay.h>
25 #include <linux/rcupdate.h>
26 #include <linux/workqueue.h>
27 #include <linux/slab.h>
28 #include <linux/export.h>
29 #include <net/tcp.h>
30 #include <net/udp.h>
31 #include <asm/unaligned.h>
32 #include <trace/events/napi.h>
33
34 /*
35 * We maintain a small pool of fully-sized skbs, to make sure the
36 * message gets out even in extreme OOM situations.
37 */
38
39 #define MAX_UDP_CHUNK 1460
40 #define MAX_SKBS 32
41
42 static struct sk_buff_head skb_pool;
43
44 static atomic_t trapped;
45
46 #define USEC_PER_POLL 50
47 #define NETPOLL_RX_ENABLED 1
48 #define NETPOLL_RX_DROP 2
49
50 #define MAX_SKB_SIZE \
51 (sizeof(struct ethhdr) + \
52 sizeof(struct iphdr) + \
53 sizeof(struct udphdr) + \
54 MAX_UDP_CHUNK)
55
56 static void zap_completion_queue(void);
57 static void arp_reply(struct sk_buff *skb);
58
59 static unsigned int carrier_timeout = 4;
60 module_param(carrier_timeout, uint, 0644);
61
62 #define np_info(np, fmt, ...) \
63 pr_info("%s: " fmt, np->name, ##__VA_ARGS__)
64 #define np_err(np, fmt, ...) \
65 pr_err("%s: " fmt, np->name, ##__VA_ARGS__)
66 #define np_notice(np, fmt, ...) \
67 pr_notice("%s: " fmt, np->name, ##__VA_ARGS__)
68
69 static void queue_process(struct work_struct *work)
70 {
71 struct netpoll_info *npinfo =
72 container_of(work, struct netpoll_info, tx_work.work);
73 struct sk_buff *skb;
74 unsigned long flags;
75
76 while ((skb = skb_dequeue(&npinfo->txq))) {
77 struct net_device *dev = skb->dev;
78 const struct net_device_ops *ops = dev->netdev_ops;
79 struct netdev_queue *txq;
80
81 if (!netif_device_present(dev) || !netif_running(dev)) {
82 __kfree_skb(skb);
83 continue;
84 }
85
86 txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb));
87
88 local_irq_save(flags);
89 __netif_tx_lock(txq, smp_processor_id());
90 if (netif_xmit_frozen_or_stopped(txq) ||
91 ops->ndo_start_xmit(skb, dev) != NETDEV_TX_OK) {
92 skb_queue_head(&npinfo->txq, skb);
93 __netif_tx_unlock(txq);
94 local_irq_restore(flags);
95
96 schedule_delayed_work(&npinfo->tx_work, HZ/10);
97 return;
98 }
99 __netif_tx_unlock(txq);
100 local_irq_restore(flags);
101 }
102 }
103
104 static __sum16 checksum_udp(struct sk_buff *skb, struct udphdr *uh,
105 unsigned short ulen, __be32 saddr, __be32 daddr)
106 {
107 __wsum psum;
108
109 if (uh->check == 0 || skb_csum_unnecessary(skb))
110 return 0;
111
112 psum = csum_tcpudp_nofold(saddr, daddr, ulen, IPPROTO_UDP, 0);
113
114 if (skb->ip_summed == CHECKSUM_COMPLETE &&
115 !csum_fold(csum_add(psum, skb->csum)))
116 return 0;
117
118 skb->csum = psum;
119
120 return __skb_checksum_complete(skb);
121 }
122
123 /*
124 * Check whether delayed processing was scheduled for our NIC. If so,
125 * we attempt to grab the poll lock and use ->poll() to pump the card.
126 * If this fails, either we've recursed in ->poll() or it's already
127 * running on another CPU.
128 *
129 * Note: we don't mask interrupts with this lock because we're using
130 * trylock here and interrupts are already disabled in the softirq
131 * case. Further, we test the poll_owner to avoid recursion on UP
132 * systems where the lock doesn't exist.
133 *
134 * In cases where there is bi-directional communications, reading only
135 * one message at a time can lead to packets being dropped by the
136 * network adapter, forcing superfluous retries and possibly timeouts.
137 * Thus, we set our budget to greater than 1.
138 */
139 static int poll_one_napi(struct netpoll_info *npinfo,
140 struct napi_struct *napi, int budget)
141 {
142 int work;
143
144 /* net_rx_action's ->poll() invocations and our's are
145 * synchronized by this test which is only made while
146 * holding the napi->poll_lock.
147 */
148 if (!test_bit(NAPI_STATE_SCHED, &napi->state))
149 return budget;
150
151 npinfo->rx_flags |= NETPOLL_RX_DROP;
152 atomic_inc(&trapped);
153 set_bit(NAPI_STATE_NPSVC, &napi->state);
154
155 work = napi->poll(napi, budget);
156 trace_napi_poll(napi);
157
158 clear_bit(NAPI_STATE_NPSVC, &napi->state);
159 atomic_dec(&trapped);
160 npinfo->rx_flags &= ~NETPOLL_RX_DROP;
161
162 return budget - work;
163 }
164
165 static void poll_napi(struct net_device *dev)
166 {
167 struct napi_struct *napi;
168 int budget = 16;
169
170 list_for_each_entry(napi, &dev->napi_list, dev_list) {
171 if (napi->poll_owner != smp_processor_id() &&
172 spin_trylock(&napi->poll_lock)) {
173 budget = poll_one_napi(dev->npinfo, napi, budget);
174 spin_unlock(&napi->poll_lock);
175
176 if (!budget)
177 break;
178 }
179 }
180 }
181
182 static void service_arp_queue(struct netpoll_info *npi)
183 {
184 if (npi) {
185 struct sk_buff *skb;
186
187 while ((skb = skb_dequeue(&npi->arp_tx)))
188 arp_reply(skb);
189 }
190 }
191
192 static void netpoll_poll_dev(struct net_device *dev)
193 {
194 const struct net_device_ops *ops;
195
196 if (!dev || !netif_running(dev))
197 return;
198
199 ops = dev->netdev_ops;
200 if (!ops->ndo_poll_controller)
201 return;
202
203 /* Process pending work on NIC */
204 ops->ndo_poll_controller(dev);
205
206 poll_napi(dev);
207
208 if (dev->flags & IFF_SLAVE) {
209 if (dev->npinfo) {
210 struct net_device *bond_dev = dev->master;
211 struct sk_buff *skb;
212 while ((skb = skb_dequeue(&dev->npinfo->arp_tx))) {
213 skb->dev = bond_dev;
214 skb_queue_tail(&bond_dev->npinfo->arp_tx, skb);
215 }
216 }
217 }
218
219 service_arp_queue(dev->npinfo);
220
221 zap_completion_queue();
222 }
223
224 static void refill_skbs(void)
225 {
226 struct sk_buff *skb;
227 unsigned long flags;
228
229 spin_lock_irqsave(&skb_pool.lock, flags);
230 while (skb_pool.qlen < MAX_SKBS) {
231 skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC);
232 if (!skb)
233 break;
234
235 __skb_queue_tail(&skb_pool, skb);
236 }
237 spin_unlock_irqrestore(&skb_pool.lock, flags);
238 }
239
240 static void zap_completion_queue(void)
241 {
242 unsigned long flags;
243 struct softnet_data *sd = &get_cpu_var(softnet_data);
244
245 if (sd->completion_queue) {
246 struct sk_buff *clist;
247
248 local_irq_save(flags);
249 clist = sd->completion_queue;
250 sd->completion_queue = NULL;
251 local_irq_restore(flags);
252
253 while (clist != NULL) {
254 struct sk_buff *skb = clist;
255 clist = clist->next;
256 if (skb->destructor) {
257 atomic_inc(&skb->users);
258 dev_kfree_skb_any(skb); /* put this one back */
259 } else {
260 __kfree_skb(skb);
261 }
262 }
263 }
264
265 put_cpu_var(softnet_data);
266 }
267
268 static struct sk_buff *find_skb(struct netpoll *np, int len, int reserve)
269 {
270 int count = 0;
271 struct sk_buff *skb;
272
273 zap_completion_queue();
274 refill_skbs();
275 repeat:
276
277 skb = alloc_skb(len, GFP_ATOMIC);
278 if (!skb)
279 skb = skb_dequeue(&skb_pool);
280
281 if (!skb) {
282 if (++count < 10) {
283 netpoll_poll_dev(np->dev);
284 goto repeat;
285 }
286 return NULL;
287 }
288
289 atomic_set(&skb->users, 1);
290 skb_reserve(skb, reserve);
291 return skb;
292 }
293
294 static int netpoll_owner_active(struct net_device *dev)
295 {
296 struct napi_struct *napi;
297
298 list_for_each_entry(napi, &dev->napi_list, dev_list) {
299 if (napi->poll_owner == smp_processor_id())
300 return 1;
301 }
302 return 0;
303 }
304
305 void netpoll_send_skb_on_dev(struct netpoll *np, struct sk_buff *skb,
306 struct net_device *dev)
307 {
308 int status = NETDEV_TX_BUSY;
309 unsigned long tries;
310 const struct net_device_ops *ops = dev->netdev_ops;
311 /* It is up to the caller to keep npinfo alive. */
312 struct netpoll_info *npinfo = np->dev->npinfo;
313
314 if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) {
315 __kfree_skb(skb);
316 return;
317 }
318
319 /* don't get messages out of order, and no recursion */
320 if (skb_queue_len(&npinfo->txq) == 0 && !netpoll_owner_active(dev)) {
321 struct netdev_queue *txq;
322 unsigned long flags;
323
324 txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb));
325
326 local_irq_save(flags);
327 /* try until next clock tick */
328 for (tries = jiffies_to_usecs(1)/USEC_PER_POLL;
329 tries > 0; --tries) {
330 if (__netif_tx_trylock(txq)) {
331 if (!netif_xmit_stopped(txq)) {
332 status = ops->ndo_start_xmit(skb, dev);
333 if (status == NETDEV_TX_OK)
334 txq_trans_update(txq);
335 }
336 __netif_tx_unlock(txq);
337
338 if (status == NETDEV_TX_OK)
339 break;
340
341 }
342
343 /* tickle device maybe there is some cleanup */
344 netpoll_poll_dev(np->dev);
345
346 udelay(USEC_PER_POLL);
347 }
348
349 WARN_ONCE(!irqs_disabled(),
350 "netpoll_send_skb(): %s enabled interrupts in poll (%pF)\n",
351 dev->name, ops->ndo_start_xmit);
352
353 local_irq_restore(flags);
354 }
355
356 if (status != NETDEV_TX_OK) {
357 skb_queue_tail(&npinfo->txq, skb);
358 schedule_delayed_work(&npinfo->tx_work,0);
359 }
360 }
361 EXPORT_SYMBOL(netpoll_send_skb_on_dev);
362
363 void netpoll_send_udp(struct netpoll *np, const char *msg, int len)
364 {
365 int total_len, eth_len, ip_len, udp_len;
366 struct sk_buff *skb;
367 struct udphdr *udph;
368 struct iphdr *iph;
369 struct ethhdr *eth;
370
371 udp_len = len + sizeof(*udph);
372 ip_len = eth_len = udp_len + sizeof(*iph);
373 total_len = eth_len + ETH_HLEN + NET_IP_ALIGN;
374
375 skb = find_skb(np, total_len, total_len - len);
376 if (!skb)
377 return;
378
379 skb_copy_to_linear_data(skb, msg, len);
380 skb->len += len;
381
382 skb_push(skb, sizeof(*udph));
383 skb_reset_transport_header(skb);
384 udph = udp_hdr(skb);
385 udph->source = htons(np->local_port);
386 udph->dest = htons(np->remote_port);
387 udph->len = htons(udp_len);
388 udph->check = 0;
389 udph->check = csum_tcpudp_magic(np->local_ip,
390 np->remote_ip,
391 udp_len, IPPROTO_UDP,
392 csum_partial(udph, udp_len, 0));
393 if (udph->check == 0)
394 udph->check = CSUM_MANGLED_0;
395
396 skb_push(skb, sizeof(*iph));
397 skb_reset_network_header(skb);
398 iph = ip_hdr(skb);
399
400 /* iph->version = 4; iph->ihl = 5; */
401 put_unaligned(0x45, (unsigned char *)iph);
402 iph->tos = 0;
403 put_unaligned(htons(ip_len), &(iph->tot_len));
404 iph->id = 0;
405 iph->frag_off = 0;
406 iph->ttl = 64;
407 iph->protocol = IPPROTO_UDP;
408 iph->check = 0;
409 put_unaligned(np->local_ip, &(iph->saddr));
410 put_unaligned(np->remote_ip, &(iph->daddr));
411 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl);
412
413 eth = (struct ethhdr *) skb_push(skb, ETH_HLEN);
414 skb_reset_mac_header(skb);
415 skb->protocol = eth->h_proto = htons(ETH_P_IP);
416 memcpy(eth->h_source, np->dev->dev_addr, ETH_ALEN);
417 memcpy(eth->h_dest, np->remote_mac, ETH_ALEN);
418
419 skb->dev = np->dev;
420
421 netpoll_send_skb(np, skb);
422 }
423 EXPORT_SYMBOL(netpoll_send_udp);
424
425 static void arp_reply(struct sk_buff *skb)
426 {
427 struct netpoll_info *npinfo = skb->dev->npinfo;
428 struct arphdr *arp;
429 unsigned char *arp_ptr;
430 int size, type = ARPOP_REPLY, ptype = ETH_P_ARP;
431 __be32 sip, tip;
432 unsigned char *sha;
433 struct sk_buff *send_skb;
434 struct netpoll *np, *tmp;
435 unsigned long flags;
436 int hlen, tlen;
437 int hits = 0;
438
439 if (list_empty(&npinfo->rx_np))
440 return;
441
442 /* Before checking the packet, we do some early
443 inspection whether this is interesting at all */
444 spin_lock_irqsave(&npinfo->rx_lock, flags);
445 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) {
446 if (np->dev == skb->dev)
447 hits++;
448 }
449 spin_unlock_irqrestore(&npinfo->rx_lock, flags);
450
451 /* No netpoll struct is using this dev */
452 if (!hits)
453 return;
454
455 /* No arp on this interface */
456 if (skb->dev->flags & IFF_NOARP)
457 return;
458
459 if (!pskb_may_pull(skb, arp_hdr_len(skb->dev)))
460 return;
461
462 skb_reset_network_header(skb);
463 skb_reset_transport_header(skb);
464 arp = arp_hdr(skb);
465
466 if ((arp->ar_hrd != htons(ARPHRD_ETHER) &&
467 arp->ar_hrd != htons(ARPHRD_IEEE802)) ||
468 arp->ar_pro != htons(ETH_P_IP) ||
469 arp->ar_op != htons(ARPOP_REQUEST))
470 return;
471
472 arp_ptr = (unsigned char *)(arp+1);
473 /* save the location of the src hw addr */
474 sha = arp_ptr;
475 arp_ptr += skb->dev->addr_len;
476 memcpy(&sip, arp_ptr, 4);
477 arp_ptr += 4;
478 /* If we actually cared about dst hw addr,
479 it would get copied here */
480 arp_ptr += skb->dev->addr_len;
481 memcpy(&tip, arp_ptr, 4);
482
483 /* Should we ignore arp? */
484 if (ipv4_is_loopback(tip) || ipv4_is_multicast(tip))
485 return;
486
487 size = arp_hdr_len(skb->dev);
488
489 spin_lock_irqsave(&npinfo->rx_lock, flags);
490 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) {
491 if (tip != np->local_ip)
492 continue;
493
494 hlen = LL_RESERVED_SPACE(np->dev);
495 tlen = np->dev->needed_tailroom;
496 send_skb = find_skb(np, size + hlen + tlen, hlen);
497 if (!send_skb)
498 continue;
499
500 skb_reset_network_header(send_skb);
501 arp = (struct arphdr *) skb_put(send_skb, size);
502 send_skb->dev = skb->dev;
503 send_skb->protocol = htons(ETH_P_ARP);
504
505 /* Fill the device header for the ARP frame */
506 if (dev_hard_header(send_skb, skb->dev, ptype,
507 sha, np->dev->dev_addr,
508 send_skb->len) < 0) {
509 kfree_skb(send_skb);
510 continue;
511 }
512
513 /*
514 * Fill out the arp protocol part.
515 *
516 * we only support ethernet device type,
517 * which (according to RFC 1390) should
518 * always equal 1 (Ethernet).
519 */
520
521 arp->ar_hrd = htons(np->dev->type);
522 arp->ar_pro = htons(ETH_P_IP);
523 arp->ar_hln = np->dev->addr_len;
524 arp->ar_pln = 4;
525 arp->ar_op = htons(type);
526
527 arp_ptr = (unsigned char *)(arp + 1);
528 memcpy(arp_ptr, np->dev->dev_addr, np->dev->addr_len);
529 arp_ptr += np->dev->addr_len;
530 memcpy(arp_ptr, &tip, 4);
531 arp_ptr += 4;
532 memcpy(arp_ptr, sha, np->dev->addr_len);
533 arp_ptr += np->dev->addr_len;
534 memcpy(arp_ptr, &sip, 4);
535
536 netpoll_send_skb(np, send_skb);
537
538 /* If there are several rx_hooks for the same address,
539 we're fine by sending a single reply */
540 break;
541 }
542 spin_unlock_irqrestore(&npinfo->rx_lock, flags);
543 }
544
545 int __netpoll_rx(struct sk_buff *skb)
546 {
547 int proto, len, ulen;
548 int hits = 0;
549 const struct iphdr *iph;
550 struct udphdr *uh;
551 struct netpoll_info *npinfo = skb->dev->npinfo;
552 struct netpoll *np, *tmp;
553
554 if (list_empty(&npinfo->rx_np))
555 goto out;
556
557 if (skb->dev->type != ARPHRD_ETHER)
558 goto out;
559
560 /* check if netpoll clients need ARP */
561 if (skb->protocol == htons(ETH_P_ARP) &&
562 atomic_read(&trapped)) {
563 skb_queue_tail(&npinfo->arp_tx, skb);
564 return 1;
565 }
566
567 proto = ntohs(eth_hdr(skb)->h_proto);
568 if (proto != ETH_P_IP)
569 goto out;
570 if (skb->pkt_type == PACKET_OTHERHOST)
571 goto out;
572 if (skb_shared(skb))
573 goto out;
574
575 if (!pskb_may_pull(skb, sizeof(struct iphdr)))
576 goto out;
577 iph = (struct iphdr *)skb->data;
578 if (iph->ihl < 5 || iph->version != 4)
579 goto out;
580 if (!pskb_may_pull(skb, iph->ihl*4))
581 goto out;
582 iph = (struct iphdr *)skb->data;
583 if (ip_fast_csum((u8 *)iph, iph->ihl) != 0)
584 goto out;
585
586 len = ntohs(iph->tot_len);
587 if (skb->len < len || len < iph->ihl*4)
588 goto out;
589
590 /*
591 * Our transport medium may have padded the buffer out.
592 * Now We trim to the true length of the frame.
593 */
594 if (pskb_trim_rcsum(skb, len))
595 goto out;
596
597 iph = (struct iphdr *)skb->data;
598 if (iph->protocol != IPPROTO_UDP)
599 goto out;
600
601 len -= iph->ihl*4;
602 uh = (struct udphdr *)(((char *)iph) + iph->ihl*4);
603 ulen = ntohs(uh->len);
604
605 if (ulen != len)
606 goto out;
607 if (checksum_udp(skb, uh, ulen, iph->saddr, iph->daddr))
608 goto out;
609
610 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) {
611 if (np->local_ip && np->local_ip != iph->daddr)
612 continue;
613 if (np->remote_ip && np->remote_ip != iph->saddr)
614 continue;
615 if (np->local_port && np->local_port != ntohs(uh->dest))
616 continue;
617
618 np->rx_hook(np, ntohs(uh->source),
619 (char *)(uh+1),
620 ulen - sizeof(struct udphdr));
621 hits++;
622 }
623
624 if (!hits)
625 goto out;
626
627 kfree_skb(skb);
628 return 1;
629
630 out:
631 if (atomic_read(&trapped)) {
632 kfree_skb(skb);
633 return 1;
634 }
635
636 return 0;
637 }
638
639 void netpoll_print_options(struct netpoll *np)
640 {
641 np_info(np, "local port %d\n", np->local_port);
642 np_info(np, "local IP %pI4\n", &np->local_ip);
643 np_info(np, "interface '%s'\n", np->dev_name);
644 np_info(np, "remote port %d\n", np->remote_port);
645 np_info(np, "remote IP %pI4\n", &np->remote_ip);
646 np_info(np, "remote ethernet address %pM\n", np->remote_mac);
647 }
648 EXPORT_SYMBOL(netpoll_print_options);
649
650 int netpoll_parse_options(struct netpoll *np, char *opt)
651 {
652 char *cur=opt, *delim;
653
654 if (*cur != '@') {
655 if ((delim = strchr(cur, '@')) == NULL)
656 goto parse_failed;
657 *delim = 0;
658 np->local_port = simple_strtol(cur, NULL, 10);
659 cur = delim;
660 }
661 cur++;
662
663 if (*cur != '/') {
664 if ((delim = strchr(cur, '/')) == NULL)
665 goto parse_failed;
666 *delim = 0;
667 np->local_ip = in_aton(cur);
668 cur = delim;
669 }
670 cur++;
671
672 if (*cur != ',') {
673 /* parse out dev name */
674 if ((delim = strchr(cur, ',')) == NULL)
675 goto parse_failed;
676 *delim = 0;
677 strlcpy(np->dev_name, cur, sizeof(np->dev_name));
678 cur = delim;
679 }
680 cur++;
681
682 if (*cur != '@') {
683 /* dst port */
684 if ((delim = strchr(cur, '@')) == NULL)
685 goto parse_failed;
686 *delim = 0;
687 if (*cur == ' ' || *cur == '\t')
688 np_info(np, "warning: whitespace is not allowed\n");
689 np->remote_port = simple_strtol(cur, NULL, 10);
690 cur = delim;
691 }
692 cur++;
693
694 /* dst ip */
695 if ((delim = strchr(cur, '/')) == NULL)
696 goto parse_failed;
697 *delim = 0;
698 np->remote_ip = in_aton(cur);
699 cur = delim + 1;
700
701 if (*cur != 0) {
702 /* MAC address */
703 if (!mac_pton(cur, np->remote_mac))
704 goto parse_failed;
705 }
706
707 netpoll_print_options(np);
708
709 return 0;
710
711 parse_failed:
712 np_info(np, "couldn't parse config at '%s'!\n", cur);
713 return -1;
714 }
715 EXPORT_SYMBOL(netpoll_parse_options);
716
717 int __netpoll_setup(struct netpoll *np)
718 {
719 struct net_device *ndev = np->dev;
720 struct netpoll_info *npinfo;
721 const struct net_device_ops *ops;
722 unsigned long flags;
723 int err;
724
725 if ((ndev->priv_flags & IFF_DISABLE_NETPOLL) ||
726 !ndev->netdev_ops->ndo_poll_controller) {
727 np_err(np, "%s doesn't support polling, aborting\n",
728 np->dev_name);
729 err = -ENOTSUPP;
730 goto out;
731 }
732
733 if (!ndev->npinfo) {
734 npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL);
735 if (!npinfo) {
736 err = -ENOMEM;
737 goto out;
738 }
739
740 npinfo->rx_flags = 0;
741 INIT_LIST_HEAD(&npinfo->rx_np);
742
743 spin_lock_init(&npinfo->rx_lock);
744 skb_queue_head_init(&npinfo->arp_tx);
745 skb_queue_head_init(&npinfo->txq);
746 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process);
747
748 atomic_set(&npinfo->refcnt, 1);
749
750 ops = np->dev->netdev_ops;
751 if (ops->ndo_netpoll_setup) {
752 err = ops->ndo_netpoll_setup(ndev, npinfo);
753 if (err)
754 goto free_npinfo;
755 }
756 } else {
757 npinfo = ndev->npinfo;
758 atomic_inc(&npinfo->refcnt);
759 }
760
761 npinfo->netpoll = np;
762
763 if (np->rx_hook) {
764 spin_lock_irqsave(&npinfo->rx_lock, flags);
765 npinfo->rx_flags |= NETPOLL_RX_ENABLED;
766 list_add_tail(&np->rx, &npinfo->rx_np);
767 spin_unlock_irqrestore(&npinfo->rx_lock, flags);
768 }
769
770 /* last thing to do is link it to the net device structure */
771 rcu_assign_pointer(ndev->npinfo, npinfo);
772
773 return 0;
774
775 free_npinfo:
776 kfree(npinfo);
777 out:
778 return err;
779 }
780 EXPORT_SYMBOL_GPL(__netpoll_setup);
781
782 int netpoll_setup(struct netpoll *np)
783 {
784 struct net_device *ndev = NULL;
785 struct in_device *in_dev;
786 int err;
787
788 if (np->dev_name)
789 ndev = dev_get_by_name(&init_net, np->dev_name);
790 if (!ndev) {
791 np_err(np, "%s doesn't exist, aborting\n", np->dev_name);
792 return -ENODEV;
793 }
794
795 if (ndev->master) {
796 np_err(np, "%s is a slave device, aborting\n", np->dev_name);
797 err = -EBUSY;
798 goto put;
799 }
800
801 if (!netif_running(ndev)) {
802 unsigned long atmost, atleast;
803
804 np_info(np, "device %s not up yet, forcing it\n", np->dev_name);
805
806 rtnl_lock();
807 err = dev_open(ndev);
808 rtnl_unlock();
809
810 if (err) {
811 np_err(np, "failed to open %s\n", ndev->name);
812 goto put;
813 }
814
815 atleast = jiffies + HZ/10;
816 atmost = jiffies + carrier_timeout * HZ;
817 while (!netif_carrier_ok(ndev)) {
818 if (time_after(jiffies, atmost)) {
819 np_notice(np, "timeout waiting for carrier\n");
820 break;
821 }
822 msleep(1);
823 }
824
825 /* If carrier appears to come up instantly, we don't
826 * trust it and pause so that we don't pump all our
827 * queued console messages into the bitbucket.
828 */
829
830 if (time_before(jiffies, atleast)) {
831 np_notice(np, "carrier detect appears untrustworthy, waiting 4 seconds\n");
832 msleep(4000);
833 }
834 }
835
836 if (!np->local_ip) {
837 rcu_read_lock();
838 in_dev = __in_dev_get_rcu(ndev);
839
840 if (!in_dev || !in_dev->ifa_list) {
841 rcu_read_unlock();
842 np_err(np, "no IP address for %s, aborting\n",
843 np->dev_name);
844 err = -EDESTADDRREQ;
845 goto put;
846 }
847
848 np->local_ip = in_dev->ifa_list->ifa_local;
849 rcu_read_unlock();
850 np_info(np, "local IP %pI4\n", &np->local_ip);
851 }
852
853 np->dev = ndev;
854
855 /* fill up the skb queue */
856 refill_skbs();
857
858 rtnl_lock();
859 err = __netpoll_setup(np);
860 rtnl_unlock();
861
862 if (err)
863 goto put;
864
865 return 0;
866
867 put:
868 dev_put(ndev);
869 return err;
870 }
871 EXPORT_SYMBOL(netpoll_setup);
872
873 static int __init netpoll_init(void)
874 {
875 skb_queue_head_init(&skb_pool);
876 return 0;
877 }
878 core_initcall(netpoll_init);
879
880 void __netpoll_cleanup(struct netpoll *np)
881 {
882 struct netpoll_info *npinfo;
883 unsigned long flags;
884
885 npinfo = np->dev->npinfo;
886 if (!npinfo)
887 return;
888
889 if (!list_empty(&npinfo->rx_np)) {
890 spin_lock_irqsave(&npinfo->rx_lock, flags);
891 list_del(&np->rx);
892 if (list_empty(&npinfo->rx_np))
893 npinfo->rx_flags &= ~NETPOLL_RX_ENABLED;
894 spin_unlock_irqrestore(&npinfo->rx_lock, flags);
895 }
896
897 if (atomic_dec_and_test(&npinfo->refcnt)) {
898 const struct net_device_ops *ops;
899
900 ops = np->dev->netdev_ops;
901 if (ops->ndo_netpoll_cleanup)
902 ops->ndo_netpoll_cleanup(np->dev);
903
904 RCU_INIT_POINTER(np->dev->npinfo, NULL);
905
906 /* avoid racing with NAPI reading npinfo */
907 synchronize_rcu_bh();
908
909 skb_queue_purge(&npinfo->arp_tx);
910 skb_queue_purge(&npinfo->txq);
911 cancel_delayed_work_sync(&npinfo->tx_work);
912
913 /* clean after last, unfinished work */
914 __skb_queue_purge(&npinfo->txq);
915 kfree(npinfo);
916 }
917 }
918 EXPORT_SYMBOL_GPL(__netpoll_cleanup);
919
920 void netpoll_cleanup(struct netpoll *np)
921 {
922 if (!np->dev)
923 return;
924
925 rtnl_lock();
926 __netpoll_cleanup(np);
927 rtnl_unlock();
928
929 dev_put(np->dev);
930 np->dev = NULL;
931 }
932 EXPORT_SYMBOL(netpoll_cleanup);
933
934 int netpoll_trap(void)
935 {
936 return atomic_read(&trapped);
937 }
938 EXPORT_SYMBOL(netpoll_trap);
939
940 void netpoll_set_trap(int trap)
941 {
942 if (trap)
943 atomic_inc(&trapped);
944 else
945 atomic_dec(&trapped);
946 }
947 EXPORT_SYMBOL(netpoll_set_trap);
Linus' kernel tree