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ipv6: Pull IPv6 GSO registration out of the module
[linux/fpc-iii.git] / net / core / netpoll.c
blob77a0388fc3beccbf39187e357c7a1b4c93f09d73
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 <linux/if_vlan.h>
30 #include <net/tcp.h>
31 #include <net/udp.h>
32 #include <asm/unaligned.h>
33 #include <trace/events/napi.h>
34
35 /*
36 * We maintain a small pool of fully-sized skbs, to make sure the
37 * message gets out even in extreme OOM situations.
38 */
39
40 #define MAX_UDP_CHUNK 1460
41 #define MAX_SKBS 32
42
43 static struct sk_buff_head skb_pool;
44
45 static atomic_t trapped;
46
47 #define USEC_PER_POLL 50
48 #define NETPOLL_RX_ENABLED 1
49 #define NETPOLL_RX_DROP 2
50
51 #define MAX_SKB_SIZE \
52 (sizeof(struct ethhdr) + \
53 sizeof(struct iphdr) + \
54 sizeof(struct udphdr) + \
55 MAX_UDP_CHUNK)
56
57 static void zap_completion_queue(void);
58 static void netpoll_arp_reply(struct sk_buff *skb, struct netpoll_info *npinfo);
59
60 static unsigned int carrier_timeout = 4;
61 module_param(carrier_timeout, uint, 0644);
62
63 #define np_info(np, fmt, ...) \
64 pr_info("%s: " fmt, np->name, ##__VA_ARGS__)
65 #define np_err(np, fmt, ...) \
66 pr_err("%s: " fmt, np->name, ##__VA_ARGS__)
67 #define np_notice(np, fmt, ...) \
68 pr_notice("%s: " fmt, np->name, ##__VA_ARGS__)
69
70 static void queue_process(struct work_struct *work)
71 {
72 struct netpoll_info *npinfo =
73 container_of(work, struct netpoll_info, tx_work.work);
74 struct sk_buff *skb;
75 unsigned long flags;
76
77 while ((skb = skb_dequeue(&npinfo->txq))) {
78 struct net_device *dev = skb->dev;
79 const struct net_device_ops *ops = dev->netdev_ops;
80 struct netdev_queue *txq;
81
82 if (!netif_device_present(dev) || !netif_running(dev)) {
83 __kfree_skb(skb);
84 continue;
85 }
86
87 txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb));
88
89 local_irq_save(flags);
90 __netif_tx_lock(txq, smp_processor_id());
91 if (netif_xmit_frozen_or_stopped(txq) ||
92 ops->ndo_start_xmit(skb, dev) != NETDEV_TX_OK) {
93 skb_queue_head(&npinfo->txq, skb);
94 __netif_tx_unlock(txq);
95 local_irq_restore(flags);
96
97 schedule_delayed_work(&npinfo->tx_work, HZ/10);
98 return;
99 }
100 __netif_tx_unlock(txq);
101 local_irq_restore(flags);
102 }
103 }
104
105 static __sum16 checksum_udp(struct sk_buff *skb, struct udphdr *uh,
106 unsigned short ulen, __be32 saddr, __be32 daddr)
107 {
108 __wsum psum;
109
110 if (uh->check == 0 || skb_csum_unnecessary(skb))
111 return 0;
112
113 psum = csum_tcpudp_nofold(saddr, daddr, ulen, IPPROTO_UDP, 0);
114
115 if (skb->ip_summed == CHECKSUM_COMPLETE &&
116 !csum_fold(csum_add(psum, skb->csum)))
117 return 0;
118
119 skb->csum = psum;
120
121 return __skb_checksum_complete(skb);
122 }
123
124 /*
125 * Check whether delayed processing was scheduled for our NIC. If so,
126 * we attempt to grab the poll lock and use ->poll() to pump the card.
127 * If this fails, either we've recursed in ->poll() or it's already
128 * running on another CPU.
129 *
130 * Note: we don't mask interrupts with this lock because we're using
131 * trylock here and interrupts are already disabled in the softirq
132 * case. Further, we test the poll_owner to avoid recursion on UP
133 * systems where the lock doesn't exist.
134 *
135 * In cases where there is bi-directional communications, reading only
136 * one message at a time can lead to packets being dropped by the
137 * network adapter, forcing superfluous retries and possibly timeouts.
138 * Thus, we set our budget to greater than 1.
139 */
140 static int poll_one_napi(struct netpoll_info *npinfo,
141 struct napi_struct *napi, int budget)
142 {
143 int work;
144
145 /* net_rx_action's ->poll() invocations and our's are
146 * synchronized by this test which is only made while
147 * holding the napi->poll_lock.
148 */
149 if (!test_bit(NAPI_STATE_SCHED, &napi->state))
150 return budget;
151
152 npinfo->rx_flags |= NETPOLL_RX_DROP;
153 atomic_inc(&trapped);
154 set_bit(NAPI_STATE_NPSVC, &napi->state);
155
156 work = napi->poll(napi, budget);
157 trace_napi_poll(napi);
158
159 clear_bit(NAPI_STATE_NPSVC, &napi->state);
160 atomic_dec(&trapped);
161 npinfo->rx_flags &= ~NETPOLL_RX_DROP;
162
163 return budget - work;
164 }
165
166 static void poll_napi(struct net_device *dev)
167 {
168 struct napi_struct *napi;
169 int budget = 16;
170
171 list_for_each_entry(napi, &dev->napi_list, dev_list) {
172 if (napi->poll_owner != smp_processor_id() &&
173 spin_trylock(&napi->poll_lock)) {
174 budget = poll_one_napi(rcu_dereference_bh(dev->npinfo),
175 napi, budget);
176 spin_unlock(&napi->poll_lock);
177
178 if (!budget)
179 break;
180 }
181 }
182 }
183
184 static void service_arp_queue(struct netpoll_info *npi)
185 {
186 if (npi) {
187 struct sk_buff *skb;
188
189 while ((skb = skb_dequeue(&npi->arp_tx)))
190 netpoll_arp_reply(skb, npi);
191 }
192 }
193
194 static void netpoll_poll_dev(struct net_device *dev)
195 {
196 const struct net_device_ops *ops;
197 struct netpoll_info *ni = rcu_dereference_bh(dev->npinfo);
198
199 if (!dev || !netif_running(dev))
200 return;
201
202 ops = dev->netdev_ops;
203 if (!ops->ndo_poll_controller)
204 return;
205
206 /* Process pending work on NIC */
207 ops->ndo_poll_controller(dev);
208
209 poll_napi(dev);
210
211 if (dev->flags & IFF_SLAVE) {
212 if (ni) {
213 struct net_device *bond_dev = dev->master;
214 struct sk_buff *skb;
215 struct netpoll_info *bond_ni = rcu_dereference_bh(bond_dev->npinfo);
216 while ((skb = skb_dequeue(&ni->arp_tx))) {
217 skb->dev = bond_dev;
218 skb_queue_tail(&bond_ni->arp_tx, skb);
219 }
220 }
221 }
222
223 service_arp_queue(ni);
224
225 zap_completion_queue();
226 }
227
228 static void refill_skbs(void)
229 {
230 struct sk_buff *skb;
231 unsigned long flags;
232
233 spin_lock_irqsave(&skb_pool.lock, flags);
234 while (skb_pool.qlen < MAX_SKBS) {
235 skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC);
236 if (!skb)
237 break;
238
239 __skb_queue_tail(&skb_pool, skb);
240 }
241 spin_unlock_irqrestore(&skb_pool.lock, flags);
242 }
243
244 static void zap_completion_queue(void)
245 {
246 unsigned long flags;
247 struct softnet_data *sd = &get_cpu_var(softnet_data);
248
249 if (sd->completion_queue) {
250 struct sk_buff *clist;
251
252 local_irq_save(flags);
253 clist = sd->completion_queue;
254 sd->completion_queue = NULL;
255 local_irq_restore(flags);
256
257 while (clist != NULL) {
258 struct sk_buff *skb = clist;
259 clist = clist->next;
260 if (skb->destructor) {
261 atomic_inc(&skb->users);
262 dev_kfree_skb_any(skb); /* put this one back */
263 } else {
264 __kfree_skb(skb);
265 }
266 }
267 }
268
269 put_cpu_var(softnet_data);
270 }
271
272 static struct sk_buff *find_skb(struct netpoll *np, int len, int reserve)
273 {
274 int count = 0;
275 struct sk_buff *skb;
276
277 zap_completion_queue();
278 refill_skbs();
279 repeat:
280
281 skb = alloc_skb(len, GFP_ATOMIC);
282 if (!skb)
283 skb = skb_dequeue(&skb_pool);
284
285 if (!skb) {
286 if (++count < 10) {
287 netpoll_poll_dev(np->dev);
288 goto repeat;
289 }
290 return NULL;
291 }
292
293 atomic_set(&skb->users, 1);
294 skb_reserve(skb, reserve);
295 return skb;
296 }
297
298 static int netpoll_owner_active(struct net_device *dev)
299 {
300 struct napi_struct *napi;
301
302 list_for_each_entry(napi, &dev->napi_list, dev_list) {
303 if (napi->poll_owner == smp_processor_id())
304 return 1;
305 }
306 return 0;
307 }
308
309 /* call with IRQ disabled */
310 void netpoll_send_skb_on_dev(struct netpoll *np, struct sk_buff *skb,
311 struct net_device *dev)
312 {
313 int status = NETDEV_TX_BUSY;
314 unsigned long tries;
315 const struct net_device_ops *ops = dev->netdev_ops;
316 /* It is up to the caller to keep npinfo alive. */
317 struct netpoll_info *npinfo;
318
319 WARN_ON_ONCE(!irqs_disabled());
320
321 npinfo = rcu_dereference_bh(np->dev->npinfo);
322 if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) {
323 __kfree_skb(skb);
324 return;
325 }
326
327 /* don't get messages out of order, and no recursion */
328 if (skb_queue_len(&npinfo->txq) == 0 && !netpoll_owner_active(dev)) {
329 struct netdev_queue *txq;
330
331 txq = netdev_pick_tx(dev, skb);
332
333 /* try until next clock tick */
334 for (tries = jiffies_to_usecs(1)/USEC_PER_POLL;
335 tries > 0; --tries) {
336 if (__netif_tx_trylock(txq)) {
337 if (!netif_xmit_stopped(txq)) {
338 if (vlan_tx_tag_present(skb) &&
339 !(netif_skb_features(skb) & NETIF_F_HW_VLAN_TX)) {
340 skb = __vlan_put_tag(skb, vlan_tx_tag_get(skb));
341 if (unlikely(!skb))
342 break;
343 skb->vlan_tci = 0;
344 }
345
346 status = ops->ndo_start_xmit(skb, dev);
347 if (status == NETDEV_TX_OK)
348 txq_trans_update(txq);
349 }
350 __netif_tx_unlock(txq);
351
352 if (status == NETDEV_TX_OK)
353 break;
354
355 }
356
357 /* tickle device maybe there is some cleanup */
358 netpoll_poll_dev(np->dev);
359
360 udelay(USEC_PER_POLL);
361 }
362
363 WARN_ONCE(!irqs_disabled(),
364 "netpoll_send_skb_on_dev(): %s enabled interrupts in poll (%pF)\n",
365 dev->name, ops->ndo_start_xmit);
366
367 }
368
369 if (status != NETDEV_TX_OK) {
370 skb_queue_tail(&npinfo->txq, skb);
371 schedule_delayed_work(&npinfo->tx_work,0);
372 }
373 }
374 EXPORT_SYMBOL(netpoll_send_skb_on_dev);
375
376 void netpoll_send_udp(struct netpoll *np, const char *msg, int len)
377 {
378 int total_len, ip_len, udp_len;
379 struct sk_buff *skb;
380 struct udphdr *udph;
381 struct iphdr *iph;
382 struct ethhdr *eth;
383 static atomic_t ip_ident;
384
385 udp_len = len + sizeof(*udph);
386 ip_len = udp_len + sizeof(*iph);
387 total_len = ip_len + LL_RESERVED_SPACE(np->dev);
388
389 skb = find_skb(np, total_len + np->dev->needed_tailroom,
390 total_len - len);
391 if (!skb)
392 return;
393
394 skb_copy_to_linear_data(skb, msg, len);
395 skb_put(skb, len);
396
397 skb_push(skb, sizeof(*udph));
398 skb_reset_transport_header(skb);
399 udph = udp_hdr(skb);
400 udph->source = htons(np->local_port);
401 udph->dest = htons(np->remote_port);
402 udph->len = htons(udp_len);
403 udph->check = 0;
404 udph->check = csum_tcpudp_magic(np->local_ip,
405 np->remote_ip,
406 udp_len, IPPROTO_UDP,
407 csum_partial(udph, udp_len, 0));
408 if (udph->check == 0)
409 udph->check = CSUM_MANGLED_0;
410
411 skb_push(skb, sizeof(*iph));
412 skb_reset_network_header(skb);
413 iph = ip_hdr(skb);
414
415 /* iph->version = 4; iph->ihl = 5; */
416 put_unaligned(0x45, (unsigned char *)iph);
417 iph->tos = 0;
418 put_unaligned(htons(ip_len), &(iph->tot_len));
419 iph->id = htons(atomic_inc_return(&ip_ident));
420 iph->frag_off = 0;
421 iph->ttl = 64;
422 iph->protocol = IPPROTO_UDP;
423 iph->check = 0;
424 put_unaligned(np->local_ip, &(iph->saddr));
425 put_unaligned(np->remote_ip, &(iph->daddr));
426 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl);
427
428 eth = (struct ethhdr *) skb_push(skb, ETH_HLEN);
429 skb_reset_mac_header(skb);
430 skb->protocol = eth->h_proto = htons(ETH_P_IP);
431 memcpy(eth->h_source, np->dev->dev_addr, ETH_ALEN);
432 memcpy(eth->h_dest, np->remote_mac, ETH_ALEN);
433
434 skb->dev = np->dev;
435
436 netpoll_send_skb(np, skb);
437 }
438 EXPORT_SYMBOL(netpoll_send_udp);
439
440 static void netpoll_arp_reply(struct sk_buff *skb, struct netpoll_info *npinfo)
441 {
442 struct arphdr *arp;
443 unsigned char *arp_ptr;
444 int size, type = ARPOP_REPLY, ptype = ETH_P_ARP;
445 __be32 sip, tip;
446 unsigned char *sha;
447 struct sk_buff *send_skb;
448 struct netpoll *np, *tmp;
449 unsigned long flags;
450 int hlen, tlen;
451 int hits = 0;
452
453 if (list_empty(&npinfo->rx_np))
454 return;
455
456 /* Before checking the packet, we do some early
457 inspection whether this is interesting at all */
458 spin_lock_irqsave(&npinfo->rx_lock, flags);
459 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) {
460 if (np->dev == skb->dev)
461 hits++;
462 }
463 spin_unlock_irqrestore(&npinfo->rx_lock, flags);
464
465 /* No netpoll struct is using this dev */
466 if (!hits)
467 return;
468
469 /* No arp on this interface */
470 if (skb->dev->flags & IFF_NOARP)
471 return;
472
473 if (!pskb_may_pull(skb, arp_hdr_len(skb->dev)))
474 return;
475
476 skb_reset_network_header(skb);
477 skb_reset_transport_header(skb);
478 arp = arp_hdr(skb);
479
480 if ((arp->ar_hrd != htons(ARPHRD_ETHER) &&
481 arp->ar_hrd != htons(ARPHRD_IEEE802)) ||
482 arp->ar_pro != htons(ETH_P_IP) ||
483 arp->ar_op != htons(ARPOP_REQUEST))
484 return;
485
486 arp_ptr = (unsigned char *)(arp+1);
487 /* save the location of the src hw addr */
488 sha = arp_ptr;
489 arp_ptr += skb->dev->addr_len;
490 memcpy(&sip, arp_ptr, 4);
491 arp_ptr += 4;
492 /* If we actually cared about dst hw addr,
493 it would get copied here */
494 arp_ptr += skb->dev->addr_len;
495 memcpy(&tip, arp_ptr, 4);
496
497 /* Should we ignore arp? */
498 if (ipv4_is_loopback(tip) || ipv4_is_multicast(tip))
499 return;
500
501 size = arp_hdr_len(skb->dev);
502
503 spin_lock_irqsave(&npinfo->rx_lock, flags);
504 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) {
505 if (tip != np->local_ip)
506 continue;
507
508 hlen = LL_RESERVED_SPACE(np->dev);
509 tlen = np->dev->needed_tailroom;
510 send_skb = find_skb(np, size + hlen + tlen, hlen);
511 if (!send_skb)
512 continue;
513
514 skb_reset_network_header(send_skb);
515 arp = (struct arphdr *) skb_put(send_skb, size);
516 send_skb->dev = skb->dev;
517 send_skb->protocol = htons(ETH_P_ARP);
518
519 /* Fill the device header for the ARP frame */
520 if (dev_hard_header(send_skb, skb->dev, ptype,
521 sha, np->dev->dev_addr,
522 send_skb->len) < 0) {
523 kfree_skb(send_skb);
524 continue;
525 }
526
527 /*
528 * Fill out the arp protocol part.
529 *
530 * we only support ethernet device type,
531 * which (according to RFC 1390) should
532 * always equal 1 (Ethernet).
533 */
534
535 arp->ar_hrd = htons(np->dev->type);
536 arp->ar_pro = htons(ETH_P_IP);
537 arp->ar_hln = np->dev->addr_len;
538 arp->ar_pln = 4;
539 arp->ar_op = htons(type);
540
541 arp_ptr = (unsigned char *)(arp + 1);
542 memcpy(arp_ptr, np->dev->dev_addr, np->dev->addr_len);
543 arp_ptr += np->dev->addr_len;
544 memcpy(arp_ptr, &tip, 4);
545 arp_ptr += 4;
546 memcpy(arp_ptr, sha, np->dev->addr_len);
547 arp_ptr += np->dev->addr_len;
548 memcpy(arp_ptr, &sip, 4);
549
550 netpoll_send_skb(np, send_skb);
551
552 /* If there are several rx_hooks for the same address,
553 we're fine by sending a single reply */
554 break;
555 }
556 spin_unlock_irqrestore(&npinfo->rx_lock, flags);
557 }
558
559 int __netpoll_rx(struct sk_buff *skb, struct netpoll_info *npinfo)
560 {
561 int proto, len, ulen;
562 int hits = 0;
563 const struct iphdr *iph;
564 struct udphdr *uh;
565 struct netpoll *np, *tmp;
566
567 if (list_empty(&npinfo->rx_np))
568 goto out;
569
570 if (skb->dev->type != ARPHRD_ETHER)
571 goto out;
572
573 /* check if netpoll clients need ARP */
574 if (skb->protocol == htons(ETH_P_ARP) &&
575 atomic_read(&trapped)) {
576 skb_queue_tail(&npinfo->arp_tx, skb);
577 return 1;
578 }
579
580 if (skb->protocol == cpu_to_be16(ETH_P_8021Q)) {
581 skb = vlan_untag(skb);
582 if (unlikely(!skb))
583 goto out;
584 }
585
586 proto = ntohs(eth_hdr(skb)->h_proto);
587 if (proto != ETH_P_IP)
588 goto out;
589 if (skb->pkt_type == PACKET_OTHERHOST)
590 goto out;
591 if (skb_shared(skb))
592 goto out;
593
594 if (!pskb_may_pull(skb, sizeof(struct iphdr)))
595 goto out;
596 iph = (struct iphdr *)skb->data;
597 if (iph->ihl < 5 || iph->version != 4)
598 goto out;
599 if (!pskb_may_pull(skb, iph->ihl*4))
600 goto out;
601 iph = (struct iphdr *)skb->data;
602 if (ip_fast_csum((u8 *)iph, iph->ihl) != 0)
603 goto out;
604
605 len = ntohs(iph->tot_len);
606 if (skb->len < len || len < iph->ihl*4)
607 goto out;
608
609 /*
610 * Our transport medium may have padded the buffer out.
611 * Now We trim to the true length of the frame.
612 */
613 if (pskb_trim_rcsum(skb, len))
614 goto out;
615
616 iph = (struct iphdr *)skb->data;
617 if (iph->protocol != IPPROTO_UDP)
618 goto out;
619
620 len -= iph->ihl*4;
621 uh = (struct udphdr *)(((char *)iph) + iph->ihl*4);
622 ulen = ntohs(uh->len);
623
624 if (ulen != len)
625 goto out;
626 if (checksum_udp(skb, uh, ulen, iph->saddr, iph->daddr))
627 goto out;
628
629 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) {
630 if (np->local_ip && np->local_ip != iph->daddr)
631 continue;
632 if (np->remote_ip && np->remote_ip != iph->saddr)
633 continue;
634 if (np->local_port && np->local_port != ntohs(uh->dest))
635 continue;
636
637 np->rx_hook(np, ntohs(uh->source),
638 (char *)(uh+1),
639 ulen - sizeof(struct udphdr));
640 hits++;
641 }
642
643 if (!hits)
644 goto out;
645
646 kfree_skb(skb);
647 return 1;
648
649 out:
650 if (atomic_read(&trapped)) {
651 kfree_skb(skb);
652 return 1;
653 }
654
655 return 0;
656 }
657
658 void netpoll_print_options(struct netpoll *np)
659 {
660 np_info(np, "local port %d\n", np->local_port);
661 np_info(np, "local IP %pI4\n", &np->local_ip);
662 np_info(np, "interface '%s'\n", np->dev_name);
663 np_info(np, "remote port %d\n", np->remote_port);
664 np_info(np, "remote IP %pI4\n", &np->remote_ip);
665 np_info(np, "remote ethernet address %pM\n", np->remote_mac);
666 }
667 EXPORT_SYMBOL(netpoll_print_options);
668
669 int netpoll_parse_options(struct netpoll *np, char *opt)
670 {
671 char *cur=opt, *delim;
672
673 if (*cur != '@') {
674 if ((delim = strchr(cur, '@')) == NULL)
675 goto parse_failed;
676 *delim = 0;
677 np->local_port = simple_strtol(cur, NULL, 10);
678 cur = delim;
679 }
680 cur++;
681
682 if (*cur != '/') {
683 if ((delim = strchr(cur, '/')) == NULL)
684 goto parse_failed;
685 *delim = 0;
686 np->local_ip = in_aton(cur);
687 cur = delim;
688 }
689 cur++;
690
691 if (*cur != ',') {
692 /* parse out dev name */
693 if ((delim = strchr(cur, ',')) == NULL)
694 goto parse_failed;
695 *delim = 0;
696 strlcpy(np->dev_name, cur, sizeof(np->dev_name));
697 cur = delim;
698 }
699 cur++;
700
701 if (*cur != '@') {
702 /* dst port */
703 if ((delim = strchr(cur, '@')) == NULL)
704 goto parse_failed;
705 *delim = 0;
706 if (*cur == ' ' || *cur == '\t')
707 np_info(np, "warning: whitespace is not allowed\n");
708 np->remote_port = simple_strtol(cur, NULL, 10);
709 cur = delim;
710 }
711 cur++;
712
713 /* dst ip */
714 if ((delim = strchr(cur, '/')) == NULL)
715 goto parse_failed;
716 *delim = 0;
717 np->remote_ip = in_aton(cur);
718 cur = delim + 1;
719
720 if (*cur != 0) {
721 /* MAC address */
722 if (!mac_pton(cur, np->remote_mac))
723 goto parse_failed;
724 }
725
726 netpoll_print_options(np);
727
728 return 0;
729
730 parse_failed:
731 np_info(np, "couldn't parse config at '%s'!\n", cur);
732 return -1;
733 }
734 EXPORT_SYMBOL(netpoll_parse_options);
735
736 int __netpoll_setup(struct netpoll *np, struct net_device *ndev, gfp_t gfp)
737 {
738 struct netpoll_info *npinfo;
739 const struct net_device_ops *ops;
740 unsigned long flags;
741 int err;
742
743 np->dev = ndev;
744 strlcpy(np->dev_name, ndev->name, IFNAMSIZ);
745
746 if ((ndev->priv_flags & IFF_DISABLE_NETPOLL) ||
747 !ndev->netdev_ops->ndo_poll_controller) {
748 np_err(np, "%s doesn't support polling, aborting\n",
749 np->dev_name);
750 err = -ENOTSUPP;
751 goto out;
752 }
753
754 if (!ndev->npinfo) {
755 npinfo = kmalloc(sizeof(*npinfo), gfp);
756 if (!npinfo) {
757 err = -ENOMEM;
758 goto out;
759 }
760
761 npinfo->rx_flags = 0;
762 INIT_LIST_HEAD(&npinfo->rx_np);
763
764 spin_lock_init(&npinfo->rx_lock);
765 skb_queue_head_init(&npinfo->arp_tx);
766 skb_queue_head_init(&npinfo->txq);
767 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process);
768
769 atomic_set(&npinfo->refcnt, 1);
770
771 ops = np->dev->netdev_ops;
772 if (ops->ndo_netpoll_setup) {
773 err = ops->ndo_netpoll_setup(ndev, npinfo, gfp);
774 if (err)
775 goto free_npinfo;
776 }
777 } else {
778 npinfo = ndev->npinfo;
779 atomic_inc(&npinfo->refcnt);
780 }
781
782 npinfo->netpoll = np;
783
784 if (np->rx_hook) {
785 spin_lock_irqsave(&npinfo->rx_lock, flags);
786 npinfo->rx_flags |= NETPOLL_RX_ENABLED;
787 list_add_tail(&np->rx, &npinfo->rx_np);
788 spin_unlock_irqrestore(&npinfo->rx_lock, flags);
789 }
790
791 /* last thing to do is link it to the net device structure */
792 rcu_assign_pointer(ndev->npinfo, npinfo);
793
794 return 0;
795
796 free_npinfo:
797 kfree(npinfo);
798 out:
799 return err;
800 }
801 EXPORT_SYMBOL_GPL(__netpoll_setup);
802
803 int netpoll_setup(struct netpoll *np)
804 {
805 struct net_device *ndev = NULL;
806 struct in_device *in_dev;
807 int err;
808
809 if (np->dev_name)
810 ndev = dev_get_by_name(&init_net, np->dev_name);
811 if (!ndev) {
812 np_err(np, "%s doesn't exist, aborting\n", np->dev_name);
813 return -ENODEV;
814 }
815
816 if (ndev->master) {
817 np_err(np, "%s is a slave device, aborting\n", np->dev_name);
818 err = -EBUSY;
819 goto put;
820 }
821
822 if (!netif_running(ndev)) {
823 unsigned long atmost, atleast;
824
825 np_info(np, "device %s not up yet, forcing it\n", np->dev_name);
826
827 rtnl_lock();
828 err = dev_open(ndev);
829 rtnl_unlock();
830
831 if (err) {
832 np_err(np, "failed to open %s\n", ndev->name);
833 goto put;
834 }
835
836 atleast = jiffies + HZ/10;
837 atmost = jiffies + carrier_timeout * HZ;
838 while (!netif_carrier_ok(ndev)) {
839 if (time_after(jiffies, atmost)) {
840 np_notice(np, "timeout waiting for carrier\n");
841 break;
842 }
843 msleep(1);
844 }
845
846 /* If carrier appears to come up instantly, we don't
847 * trust it and pause so that we don't pump all our
848 * queued console messages into the bitbucket.
849 */
850
851 if (time_before(jiffies, atleast)) {
852 np_notice(np, "carrier detect appears untrustworthy, waiting 4 seconds\n");
853 msleep(4000);
854 }
855 }
856
857 if (!np->local_ip) {
858 rcu_read_lock();
859 in_dev = __in_dev_get_rcu(ndev);
860
861 if (!in_dev || !in_dev->ifa_list) {
862 rcu_read_unlock();
863 np_err(np, "no IP address for %s, aborting\n",
864 np->dev_name);
865 err = -EDESTADDRREQ;
866 goto put;
867 }
868
869 np->local_ip = in_dev->ifa_list->ifa_local;
870 rcu_read_unlock();
871 np_info(np, "local IP %pI4\n", &np->local_ip);
872 }
873
874 /* fill up the skb queue */
875 refill_skbs();
876
877 rtnl_lock();
878 err = __netpoll_setup(np, ndev, GFP_KERNEL);
879 rtnl_unlock();
880
881 if (err)
882 goto put;
883
884 return 0;
885
886 put:
887 dev_put(ndev);
888 return err;
889 }
890 EXPORT_SYMBOL(netpoll_setup);
891
892 static int __init netpoll_init(void)
893 {
894 skb_queue_head_init(&skb_pool);
895 return 0;
896 }
897 core_initcall(netpoll_init);
898
899 static void rcu_cleanup_netpoll_info(struct rcu_head *rcu_head)
900 {
901 struct netpoll_info *npinfo =
902 container_of(rcu_head, struct netpoll_info, rcu);
903
904 skb_queue_purge(&npinfo->arp_tx);
905 skb_queue_purge(&npinfo->txq);
906
907 /* we can't call cancel_delayed_work_sync here, as we are in softirq */
908 cancel_delayed_work(&npinfo->tx_work);
909
910 /* clean after last, unfinished work */
911 __skb_queue_purge(&npinfo->txq);
912 /* now cancel it again */
913 cancel_delayed_work(&npinfo->tx_work);
914 kfree(npinfo);
915 }
916
917 void __netpoll_cleanup(struct netpoll *np)
918 {
919 struct netpoll_info *npinfo;
920 unsigned long flags;
921
922 npinfo = np->dev->npinfo;
923 if (!npinfo)
924 return;
925
926 if (!list_empty(&npinfo->rx_np)) {
927 spin_lock_irqsave(&npinfo->rx_lock, flags);
928 list_del(&np->rx);
929 if (list_empty(&npinfo->rx_np))
930 npinfo->rx_flags &= ~NETPOLL_RX_ENABLED;
931 spin_unlock_irqrestore(&npinfo->rx_lock, flags);
932 }
933
934 if (atomic_dec_and_test(&npinfo->refcnt)) {
935 const struct net_device_ops *ops;
936
937 ops = np->dev->netdev_ops;
938 if (ops->ndo_netpoll_cleanup)
939 ops->ndo_netpoll_cleanup(np->dev);
940
941 RCU_INIT_POINTER(np->dev->npinfo, NULL);
942 call_rcu_bh(&npinfo->rcu, rcu_cleanup_netpoll_info);
943 }
944 }
945 EXPORT_SYMBOL_GPL(__netpoll_cleanup);
946
947 static void rcu_cleanup_netpoll(struct rcu_head *rcu_head)
948 {
949 struct netpoll *np = container_of(rcu_head, struct netpoll, rcu);
950
951 __netpoll_cleanup(np);
952 kfree(np);
953 }
954
955 void __netpoll_free_rcu(struct netpoll *np)
956 {
957 call_rcu_bh(&np->rcu, rcu_cleanup_netpoll);
958 }
959 EXPORT_SYMBOL_GPL(__netpoll_free_rcu);
960
961 void netpoll_cleanup(struct netpoll *np)
962 {
963 if (!np->dev)
964 return;
965
966 rtnl_lock();
967 __netpoll_cleanup(np);
968 rtnl_unlock();
969
970 dev_put(np->dev);
971 np->dev = NULL;
972 }
973 EXPORT_SYMBOL(netpoll_cleanup);
974
975 int netpoll_trap(void)
976 {
977 return atomic_read(&trapped);
978 }
979 EXPORT_SYMBOL(netpoll_trap);
980
981 void netpoll_set_trap(int trap)
982 {
983 if (trap)
984 atomic_inc(&trapped);
985 else
986 atomic_dec(&trapped);
987 }
988 EXPORT_SYMBOL(netpoll_set_trap);
Linux with added FPC-III support