bonding: Fix bonding drivers improper modification of netpoll structure
[linux-2.6.git] / net / core / netpoll.c
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/moduleparam.h>
13 #include <linux/netdevice.h>
14 #include <linux/etherdevice.h>
15 #include <linux/string.h>
16 #include <linux/if_arp.h>
17 #include <linux/inetdevice.h>
18 #include <linux/inet.h>
19 #include <linux/interrupt.h>
20 #include <linux/netpoll.h>
21 #include <linux/sched.h>
22 #include <linux/delay.h>
23 #include <linux/rcupdate.h>
24 #include <linux/workqueue.h>
25 #include <linux/slab.h>
26 #include <net/tcp.h>
27 #include <net/udp.h>
28 #include <asm/unaligned.h>
29 #include <trace/events/napi.h>
30
31 /*
32  * We maintain a small pool of fully-sized skbs, to make sure the
33  * message gets out even in extreme OOM situations.
34  */
35
36 #define MAX_UDP_CHUNK 1460
37 #define MAX_SKBS 32
38 #define MAX_QUEUE_DEPTH (MAX_SKBS / 2)
39
40 static struct sk_buff_head skb_pool;
41
42 static atomic_t trapped;
43
44 #define USEC_PER_POLL   50
45 #define NETPOLL_RX_ENABLED  1
46 #define NETPOLL_RX_DROP     2
47
48 #define MAX_SKB_SIZE \
49                 (MAX_UDP_CHUNK + sizeof(struct udphdr) + \
50                                 sizeof(struct iphdr) + sizeof(struct ethhdr))
51
52 static void zap_completion_queue(void);
53 static void arp_reply(struct sk_buff *skb);
54
55 static unsigned int carrier_timeout = 4;
56 module_param(carrier_timeout, uint, 0644);
57
58 static void queue_process(struct work_struct *work)
59 {
60         struct netpoll_info *npinfo =
61                 container_of(work, struct netpoll_info, tx_work.work);
62         struct sk_buff *skb;
63         unsigned long flags;
64
65         while ((skb = skb_dequeue(&npinfo->txq))) {
66                 struct net_device *dev = skb->dev;
67                 const struct net_device_ops *ops = dev->netdev_ops;
68                 struct netdev_queue *txq;
69
70                 if (!netif_device_present(dev) || !netif_running(dev)) {
71                         __kfree_skb(skb);
72                         continue;
73                 }
74
75                 txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb));
76
77                 local_irq_save(flags);
78                 __netif_tx_lock(txq, smp_processor_id());
79                 if (netif_tx_queue_stopped(txq) ||
80                     netif_tx_queue_frozen(txq) ||
81                     ops->ndo_start_xmit(skb, dev) != NETDEV_TX_OK) {
82                         skb_queue_head(&npinfo->txq, skb);
83                         __netif_tx_unlock(txq);
84                         local_irq_restore(flags);
85
86                         schedule_delayed_work(&npinfo->tx_work, HZ/10);
87                         return;
88                 }
89                 __netif_tx_unlock(txq);
90                 local_irq_restore(flags);
91         }
92 }
93
94 static __sum16 checksum_udp(struct sk_buff *skb, struct udphdr *uh,
95                             unsigned short ulen, __be32 saddr, __be32 daddr)
96 {
97         __wsum psum;
98
99         if (uh->check == 0 || skb_csum_unnecessary(skb))
100                 return 0;
101
102         psum = csum_tcpudp_nofold(saddr, daddr, ulen, IPPROTO_UDP, 0);
103
104         if (skb->ip_summed == CHECKSUM_COMPLETE &&
105             !csum_fold(csum_add(psum, skb->csum)))
106                 return 0;
107
108         skb->csum = psum;
109
110         return __skb_checksum_complete(skb);
111 }
112
113 /*
114  * Check whether delayed processing was scheduled for our NIC. If so,
115  * we attempt to grab the poll lock and use ->poll() to pump the card.
116  * If this fails, either we've recursed in ->poll() or it's already
117  * running on another CPU.
118  *
119  * Note: we don't mask interrupts with this lock because we're using
120  * trylock here and interrupts are already disabled in the softirq
121  * case. Further, we test the poll_owner to avoid recursion on UP
122  * systems where the lock doesn't exist.
123  *
124  * In cases where there is bi-directional communications, reading only
125  * one message at a time can lead to packets being dropped by the
126  * network adapter, forcing superfluous retries and possibly timeouts.
127  * Thus, we set our budget to greater than 1.
128  */
129 static int poll_one_napi(struct netpoll_info *npinfo,
130                          struct napi_struct *napi, int budget)
131 {
132         int work;
133
134         /* net_rx_action's ->poll() invocations and our's are
135          * synchronized by this test which is only made while
136          * holding the napi->poll_lock.
137          */
138         if (!test_bit(NAPI_STATE_SCHED, &napi->state))
139                 return budget;
140
141         npinfo->rx_flags |= NETPOLL_RX_DROP;
142         atomic_inc(&trapped);
143         set_bit(NAPI_STATE_NPSVC, &napi->state);
144
145         work = napi->poll(napi, budget);
146         trace_napi_poll(napi);
147
148         clear_bit(NAPI_STATE_NPSVC, &napi->state);
149         atomic_dec(&trapped);
150         npinfo->rx_flags &= ~NETPOLL_RX_DROP;
151
152         return budget - work;
153 }
154
155 static void poll_napi(struct net_device *dev)
156 {
157         struct napi_struct *napi;
158         int budget = 16;
159
160         list_for_each_entry(napi, &dev->napi_list, dev_list) {
161                 if (napi->poll_owner != smp_processor_id() &&
162                     spin_trylock(&napi->poll_lock)) {
163                         budget = poll_one_napi(dev->npinfo, napi, budget);
164                         spin_unlock(&napi->poll_lock);
165
166                         if (!budget)
167                                 break;
168                 }
169         }
170 }
171
172 static void service_arp_queue(struct netpoll_info *npi)
173 {
174         if (npi) {
175                 struct sk_buff *skb;
176
177                 while ((skb = skb_dequeue(&npi->arp_tx)))
178                         arp_reply(skb);
179         }
180 }
181
182 void netpoll_poll_dev(struct net_device *dev)
183 {
184         const struct net_device_ops *ops;
185
186         if (!dev || !netif_running(dev))
187                 return;
188
189         ops = dev->netdev_ops;
190         if (!ops->ndo_poll_controller)
191                 return;
192
193         /* Process pending work on NIC */
194         ops->ndo_poll_controller(dev);
195
196         poll_napi(dev);
197
198         service_arp_queue(dev->npinfo);
199
200         zap_completion_queue();
201 }
202 EXPORT_SYMBOL(netpoll_poll_dev);
203
204 void netpoll_poll(struct netpoll *np)
205 {
206         netpoll_poll_dev(np->dev);
207 }
208 EXPORT_SYMBOL(netpoll_poll);
209
210 static void refill_skbs(void)
211 {
212         struct sk_buff *skb;
213         unsigned long flags;
214
215         spin_lock_irqsave(&skb_pool.lock, flags);
216         while (skb_pool.qlen < MAX_SKBS) {
217                 skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC);
218                 if (!skb)
219                         break;
220
221                 __skb_queue_tail(&skb_pool, skb);
222         }
223         spin_unlock_irqrestore(&skb_pool.lock, flags);
224 }
225
226 static void zap_completion_queue(void)
227 {
228         unsigned long flags;
229         struct softnet_data *sd = &get_cpu_var(softnet_data);
230
231         if (sd->completion_queue) {
232                 struct sk_buff *clist;
233
234                 local_irq_save(flags);
235                 clist = sd->completion_queue;
236                 sd->completion_queue = NULL;
237                 local_irq_restore(flags);
238
239                 while (clist != NULL) {
240                         struct sk_buff *skb = clist;
241                         clist = clist->next;
242                         if (skb->destructor) {
243                                 atomic_inc(&skb->users);
244                                 dev_kfree_skb_any(skb); /* put this one back */
245                         } else {
246                                 __kfree_skb(skb);
247                         }
248                 }
249         }
250
251         put_cpu_var(softnet_data);
252 }
253
254 static struct sk_buff *find_skb(struct netpoll *np, int len, int reserve)
255 {
256         int count = 0;
257         struct sk_buff *skb;
258
259         zap_completion_queue();
260         refill_skbs();
261 repeat:
262
263         skb = alloc_skb(len, GFP_ATOMIC);
264         if (!skb)
265                 skb = skb_dequeue(&skb_pool);
266
267         if (!skb) {
268                 if (++count < 10) {
269                         netpoll_poll(np);
270                         goto repeat;
271                 }
272                 return NULL;
273         }
274
275         atomic_set(&skb->users, 1);
276         skb_reserve(skb, reserve);
277         return skb;
278 }
279
280 static int netpoll_owner_active(struct net_device *dev)
281 {
282         struct napi_struct *napi;
283
284         list_for_each_entry(napi, &dev->napi_list, dev_list) {
285                 if (napi->poll_owner == smp_processor_id())
286                         return 1;
287         }
288         return 0;
289 }
290
291 void netpoll_send_skb_on_dev(struct netpoll *np, struct sk_buff *skb,
292                              struct net_device *dev)
293 {
294         int status = NETDEV_TX_BUSY;
295         unsigned long tries;
296         const struct net_device_ops *ops = dev->netdev_ops;
297         /* It is up to the caller to keep npinfo alive. */
298         struct netpoll_info *npinfo = np->dev->npinfo;
299
300         if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) {
301                 __kfree_skb(skb);
302                 return;
303         }
304
305         /* don't get messages out of order, and no recursion */
306         if (skb_queue_len(&npinfo->txq) == 0 && !netpoll_owner_active(dev)) {
307                 struct netdev_queue *txq;
308                 unsigned long flags;
309
310                 txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb));
311
312                 local_irq_save(flags);
313                 /* try until next clock tick */
314                 for (tries = jiffies_to_usecs(1)/USEC_PER_POLL;
315                      tries > 0; --tries) {
316                         if (__netif_tx_trylock(txq)) {
317                                 if (!netif_tx_queue_stopped(txq)) {
318                                         dev->priv_flags |= IFF_IN_NETPOLL;
319                                         status = ops->ndo_start_xmit(skb, dev);
320                                         dev->priv_flags &= ~IFF_IN_NETPOLL;
321                                         if (status == NETDEV_TX_OK)
322                                                 txq_trans_update(txq);
323                                 }
324                                 __netif_tx_unlock(txq);
325
326                                 if (status == NETDEV_TX_OK)
327                                         break;
328
329                         }
330
331                         /* tickle device maybe there is some cleanup */
332                         netpoll_poll(np);
333
334                         udelay(USEC_PER_POLL);
335                 }
336
337                 WARN_ONCE(!irqs_disabled(),
338                         "netpoll_send_skb(): %s enabled interrupts in poll (%pF)\n",
339                         dev->name, ops->ndo_start_xmit);
340
341                 local_irq_restore(flags);
342         }
343
344         if (status != NETDEV_TX_OK) {
345                 skb_queue_tail(&npinfo->txq, skb);
346                 schedule_delayed_work(&npinfo->tx_work,0);
347         }
348 }
349 EXPORT_SYMBOL(netpoll_send_skb_on_dev);
350
351 void netpoll_send_udp(struct netpoll *np, const char *msg, int len)
352 {
353         int total_len, eth_len, ip_len, udp_len;
354         struct sk_buff *skb;
355         struct udphdr *udph;
356         struct iphdr *iph;
357         struct ethhdr *eth;
358
359         udp_len = len + sizeof(*udph);
360         ip_len = eth_len = udp_len + sizeof(*iph);
361         total_len = eth_len + ETH_HLEN + NET_IP_ALIGN;
362
363         skb = find_skb(np, total_len, total_len - len);
364         if (!skb)
365                 return;
366
367         skb_copy_to_linear_data(skb, msg, len);
368         skb->len += len;
369
370         skb_push(skb, sizeof(*udph));
371         skb_reset_transport_header(skb);
372         udph = udp_hdr(skb);
373         udph->source = htons(np->local_port);
374         udph->dest = htons(np->remote_port);
375         udph->len = htons(udp_len);
376         udph->check = 0;
377         udph->check = csum_tcpudp_magic(np->local_ip,
378                                         np->remote_ip,
379                                         udp_len, IPPROTO_UDP,
380                                         csum_partial(udph, udp_len, 0));
381         if (udph->check == 0)
382                 udph->check = CSUM_MANGLED_0;
383
384         skb_push(skb, sizeof(*iph));
385         skb_reset_network_header(skb);
386         iph = ip_hdr(skb);
387
388         /* iph->version = 4; iph->ihl = 5; */
389         put_unaligned(0x45, (unsigned char *)iph);
390         iph->tos      = 0;
391         put_unaligned(htons(ip_len), &(iph->tot_len));
392         iph->id       = 0;
393         iph->frag_off = 0;
394         iph->ttl      = 64;
395         iph->protocol = IPPROTO_UDP;
396         iph->check    = 0;
397         put_unaligned(np->local_ip, &(iph->saddr));
398         put_unaligned(np->remote_ip, &(iph->daddr));
399         iph->check    = ip_fast_csum((unsigned char *)iph, iph->ihl);
400
401         eth = (struct ethhdr *) skb_push(skb, ETH_HLEN);
402         skb_reset_mac_header(skb);
403         skb->protocol = eth->h_proto = htons(ETH_P_IP);
404         memcpy(eth->h_source, np->dev->dev_addr, ETH_ALEN);
405         memcpy(eth->h_dest, np->remote_mac, ETH_ALEN);
406
407         skb->dev = np->dev;
408
409         netpoll_send_skb(np, skb);
410 }
411 EXPORT_SYMBOL(netpoll_send_udp);
412
413 static void arp_reply(struct sk_buff *skb)
414 {
415         struct netpoll_info *npinfo = skb->dev->npinfo;
416         struct arphdr *arp;
417         unsigned char *arp_ptr;
418         int size, type = ARPOP_REPLY, ptype = ETH_P_ARP;
419         __be32 sip, tip;
420         unsigned char *sha;
421         struct sk_buff *send_skb;
422         struct netpoll *np, *tmp;
423         unsigned long flags;
424         int hits = 0;
425
426         if (list_empty(&npinfo->rx_np))
427                 return;
428
429         /* Before checking the packet, we do some early
430            inspection whether this is interesting at all */
431         spin_lock_irqsave(&npinfo->rx_lock, flags);
432         list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) {
433                 if (np->dev == skb->dev)
434                         hits++;
435         }
436         spin_unlock_irqrestore(&npinfo->rx_lock, flags);
437
438         /* No netpoll struct is using this dev */
439         if (!hits)
440                 return;
441
442         /* No arp on this interface */
443         if (skb->dev->flags & IFF_NOARP)
444                 return;
445
446         if (!pskb_may_pull(skb, arp_hdr_len(skb->dev)))
447                 return;
448
449         skb_reset_network_header(skb);
450         skb_reset_transport_header(skb);
451         arp = arp_hdr(skb);
452
453         if ((arp->ar_hrd != htons(ARPHRD_ETHER) &&
454              arp->ar_hrd != htons(ARPHRD_IEEE802)) ||
455             arp->ar_pro != htons(ETH_P_IP) ||
456             arp->ar_op != htons(ARPOP_REQUEST))
457                 return;
458
459         arp_ptr = (unsigned char *)(arp+1);
460         /* save the location of the src hw addr */
461         sha = arp_ptr;
462         arp_ptr += skb->dev->addr_len;
463         memcpy(&sip, arp_ptr, 4);
464         arp_ptr += 4;
465         /* If we actually cared about dst hw addr,
466            it would get copied here */
467         arp_ptr += skb->dev->addr_len;
468         memcpy(&tip, arp_ptr, 4);
469
470         /* Should we ignore arp? */
471         if (ipv4_is_loopback(tip) || ipv4_is_multicast(tip))
472                 return;
473
474         size = arp_hdr_len(skb->dev);
475
476         spin_lock_irqsave(&npinfo->rx_lock, flags);
477         list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) {
478                 if (tip != np->local_ip)
479                         continue;
480
481                 send_skb = find_skb(np, size + LL_ALLOCATED_SPACE(np->dev),
482                                     LL_RESERVED_SPACE(np->dev));
483                 if (!send_skb)
484                         continue;
485
486                 skb_reset_network_header(send_skb);
487                 arp = (struct arphdr *) skb_put(send_skb, size);
488                 send_skb->dev = skb->dev;
489                 send_skb->protocol = htons(ETH_P_ARP);
490
491                 /* Fill the device header for the ARP frame */
492                 if (dev_hard_header(send_skb, skb->dev, ptype,
493                                     sha, np->dev->dev_addr,
494                                     send_skb->len) < 0) {
495                         kfree_skb(send_skb);
496                         continue;
497                 }
498
499                 /*
500                  * Fill out the arp protocol part.
501                  *
502                  * we only support ethernet device type,
503                  * which (according to RFC 1390) should
504                  * always equal 1 (Ethernet).
505                  */
506
507                 arp->ar_hrd = htons(np->dev->type);
508                 arp->ar_pro = htons(ETH_P_IP);
509                 arp->ar_hln = np->dev->addr_len;
510                 arp->ar_pln = 4;
511                 arp->ar_op = htons(type);
512
513                 arp_ptr = (unsigned char *)(arp + 1);
514                 memcpy(arp_ptr, np->dev->dev_addr, np->dev->addr_len);
515                 arp_ptr += np->dev->addr_len;
516                 memcpy(arp_ptr, &tip, 4);
517                 arp_ptr += 4;
518                 memcpy(arp_ptr, sha, np->dev->addr_len);
519                 arp_ptr += np->dev->addr_len;
520                 memcpy(arp_ptr, &sip, 4);
521
522                 netpoll_send_skb(np, send_skb);
523
524                 /* If there are several rx_hooks for the same address,
525                    we're fine by sending a single reply */
526                 break;
527         }
528         spin_unlock_irqrestore(&npinfo->rx_lock, flags);
529 }
530
531 int __netpoll_rx(struct sk_buff *skb)
532 {
533         int proto, len, ulen;
534         int hits = 0;
535         struct iphdr *iph;
536         struct udphdr *uh;
537         struct netpoll_info *npinfo = skb->dev->npinfo;
538         struct netpoll *np, *tmp;
539
540         if (list_empty(&npinfo->rx_np))
541                 goto out;
542
543         if (skb->dev->type != ARPHRD_ETHER)
544                 goto out;
545
546         /* check if netpoll clients need ARP */
547         if (skb->protocol == htons(ETH_P_ARP) &&
548             atomic_read(&trapped)) {
549                 skb_queue_tail(&npinfo->arp_tx, skb);
550                 return 1;
551         }
552
553         proto = ntohs(eth_hdr(skb)->h_proto);
554         if (proto != ETH_P_IP)
555                 goto out;
556         if (skb->pkt_type == PACKET_OTHERHOST)
557                 goto out;
558         if (skb_shared(skb))
559                 goto out;
560
561         iph = (struct iphdr *)skb->data;
562         if (!pskb_may_pull(skb, sizeof(struct iphdr)))
563                 goto out;
564         if (iph->ihl < 5 || iph->version != 4)
565                 goto out;
566         if (!pskb_may_pull(skb, iph->ihl*4))
567                 goto out;
568         if (ip_fast_csum((u8 *)iph, iph->ihl) != 0)
569                 goto out;
570
571         len = ntohs(iph->tot_len);
572         if (skb->len < len || len < iph->ihl*4)
573                 goto out;
574
575         /*
576          * Our transport medium may have padded the buffer out.
577          * Now We trim to the true length of the frame.
578          */
579         if (pskb_trim_rcsum(skb, len))
580                 goto out;
581
582         if (iph->protocol != IPPROTO_UDP)
583                 goto out;
584
585         len -= iph->ihl*4;
586         uh = (struct udphdr *)(((char *)iph) + iph->ihl*4);
587         ulen = ntohs(uh->len);
588
589         if (ulen != len)
590                 goto out;
591         if (checksum_udp(skb, uh, ulen, iph->saddr, iph->daddr))
592                 goto out;
593
594         list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) {
595                 if (np->local_ip && np->local_ip != iph->daddr)
596                         continue;
597                 if (np->remote_ip && np->remote_ip != iph->saddr)
598                         continue;
599                 if (np->local_port && np->local_port != ntohs(uh->dest))
600                         continue;
601
602                 np->rx_hook(np, ntohs(uh->source),
603                                (char *)(uh+1),
604                                ulen - sizeof(struct udphdr));
605                 hits++;
606         }
607
608         if (!hits)
609                 goto out;
610
611         kfree_skb(skb);
612         return 1;
613
614 out:
615         if (atomic_read(&trapped)) {
616                 kfree_skb(skb);
617                 return 1;
618         }
619
620         return 0;
621 }
622
623 void netpoll_print_options(struct netpoll *np)
624 {
625         printk(KERN_INFO "%s: local port %d\n",
626                          np->name, np->local_port);
627         printk(KERN_INFO "%s: local IP %pI4\n",
628                          np->name, &np->local_ip);
629         printk(KERN_INFO "%s: interface '%s'\n",
630                          np->name, np->dev_name);
631         printk(KERN_INFO "%s: remote port %d\n",
632                          np->name, np->remote_port);
633         printk(KERN_INFO "%s: remote IP %pI4\n",
634                          np->name, &np->remote_ip);
635         printk(KERN_INFO "%s: remote ethernet address %pM\n",
636                          np->name, np->remote_mac);
637 }
638 EXPORT_SYMBOL(netpoll_print_options);
639
640 int netpoll_parse_options(struct netpoll *np, char *opt)
641 {
642         char *cur=opt, *delim;
643
644         if (*cur != '@') {
645                 if ((delim = strchr(cur, '@')) == NULL)
646                         goto parse_failed;
647                 *delim = 0;
648                 np->local_port = simple_strtol(cur, NULL, 10);
649                 cur = delim;
650         }
651         cur++;
652
653         if (*cur != '/') {
654                 if ((delim = strchr(cur, '/')) == NULL)
655                         goto parse_failed;
656                 *delim = 0;
657                 np->local_ip = in_aton(cur);
658                 cur = delim;
659         }
660         cur++;
661
662         if (*cur != ',') {
663                 /* parse out dev name */
664                 if ((delim = strchr(cur, ',')) == NULL)
665                         goto parse_failed;
666                 *delim = 0;
667                 strlcpy(np->dev_name, cur, sizeof(np->dev_name));
668                 cur = delim;
669         }
670         cur++;
671
672         if (*cur != '@') {
673                 /* dst port */
674                 if ((delim = strchr(cur, '@')) == NULL)
675                         goto parse_failed;
676                 *delim = 0;
677                 if (*cur == ' ' || *cur == '\t')
678                         printk(KERN_INFO "%s: warning: whitespace"
679                                         "is not allowed\n", np->name);
680                 np->remote_port = simple_strtol(cur, NULL, 10);
681                 cur = delim;
682         }
683         cur++;
684
685         /* dst ip */
686         if ((delim = strchr(cur, '/')) == NULL)
687                 goto parse_failed;
688         *delim = 0;
689         np->remote_ip = in_aton(cur);
690         cur = delim + 1;
691
692         if (*cur != 0) {
693                 /* MAC address */
694                 if ((delim = strchr(cur, ':')) == NULL)
695                         goto parse_failed;
696                 *delim = 0;
697                 np->remote_mac[0] = simple_strtol(cur, NULL, 16);
698                 cur = delim + 1;
699                 if ((delim = strchr(cur, ':')) == NULL)
700                         goto parse_failed;
701                 *delim = 0;
702                 np->remote_mac[1] = simple_strtol(cur, NULL, 16);
703                 cur = delim + 1;
704                 if ((delim = strchr(cur, ':')) == NULL)
705                         goto parse_failed;
706                 *delim = 0;
707                 np->remote_mac[2] = simple_strtol(cur, NULL, 16);
708                 cur = delim + 1;
709                 if ((delim = strchr(cur, ':')) == NULL)
710                         goto parse_failed;
711                 *delim = 0;
712                 np->remote_mac[3] = simple_strtol(cur, NULL, 16);
713                 cur = delim + 1;
714                 if ((delim = strchr(cur, ':')) == NULL)
715                         goto parse_failed;
716                 *delim = 0;
717                 np->remote_mac[4] = simple_strtol(cur, NULL, 16);
718                 cur = delim + 1;
719                 np->remote_mac[5] = simple_strtol(cur, NULL, 16);
720         }
721
722         netpoll_print_options(np);
723
724         return 0;
725
726  parse_failed:
727         printk(KERN_INFO "%s: couldn't parse config at '%s'!\n",
728                np->name, cur);
729         return -1;
730 }
731 EXPORT_SYMBOL(netpoll_parse_options);
732
733 int __netpoll_setup(struct netpoll *np)
734 {
735         struct net_device *ndev = np->dev;
736         struct netpoll_info *npinfo;
737         const struct net_device_ops *ops;
738         unsigned long flags;
739         int err;
740
741         if ((ndev->priv_flags & IFF_DISABLE_NETPOLL) ||
742             !ndev->netdev_ops->ndo_poll_controller) {
743                 printk(KERN_ERR "%s: %s doesn't support polling, aborting.\n",
744                        np->name, np->dev_name);
745                 err = -ENOTSUPP;
746                 goto out;
747         }
748
749         if (!ndev->npinfo) {
750                 npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL);
751                 if (!npinfo) {
752                         err = -ENOMEM;
753                         goto out;
754                 }
755
756                 npinfo->rx_flags = 0;
757                 INIT_LIST_HEAD(&npinfo->rx_np);
758
759                 spin_lock_init(&npinfo->rx_lock);
760                 skb_queue_head_init(&npinfo->arp_tx);
761                 skb_queue_head_init(&npinfo->txq);
762                 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process);
763
764                 atomic_set(&npinfo->refcnt, 1);
765
766                 ops = np->dev->netdev_ops;
767                 if (ops->ndo_netpoll_setup) {
768                         err = ops->ndo_netpoll_setup(ndev, npinfo);
769                         if (err)
770                                 goto free_npinfo;
771                 }
772         } else {
773                 npinfo = ndev->npinfo;
774                 atomic_inc(&npinfo->refcnt);
775         }
776
777         npinfo->netpoll = np;
778
779         if (np->rx_hook) {
780                 spin_lock_irqsave(&npinfo->rx_lock, flags);
781                 npinfo->rx_flags |= NETPOLL_RX_ENABLED;
782                 list_add_tail(&np->rx, &npinfo->rx_np);
783                 spin_unlock_irqrestore(&npinfo->rx_lock, flags);
784         }
785
786         /* last thing to do is link it to the net device structure */
787         rcu_assign_pointer(ndev->npinfo, npinfo);
788
789         return 0;
790
791 free_npinfo:
792         kfree(npinfo);
793 out:
794         return err;
795 }
796 EXPORT_SYMBOL_GPL(__netpoll_setup);
797
798 int netpoll_setup(struct netpoll *np)
799 {
800         struct net_device *ndev = NULL;
801         struct in_device *in_dev;
802         int err;
803
804         if (np->dev_name)
805                 ndev = dev_get_by_name(&init_net, np->dev_name);
806         if (!ndev) {
807                 printk(KERN_ERR "%s: %s doesn't exist, aborting.\n",
808                        np->name, np->dev_name);
809                 return -ENODEV;
810         }
811
812         if (!netif_running(ndev)) {
813                 unsigned long atmost, atleast;
814
815                 printk(KERN_INFO "%s: device %s not up yet, forcing it\n",
816                        np->name, np->dev_name);
817
818                 rtnl_lock();
819                 err = dev_open(ndev);
820                 rtnl_unlock();
821
822                 if (err) {
823                         printk(KERN_ERR "%s: failed to open %s\n",
824                                np->name, ndev->name);
825                         goto put;
826                 }
827
828                 atleast = jiffies + HZ/10;
829                 atmost = jiffies + carrier_timeout * HZ;
830                 while (!netif_carrier_ok(ndev)) {
831                         if (time_after(jiffies, atmost)) {
832                                 printk(KERN_NOTICE
833                                        "%s: timeout waiting for carrier\n",
834                                        np->name);
835                                 break;
836                         }
837                         msleep(1);
838                 }
839
840                 /* If carrier appears to come up instantly, we don't
841                  * trust it and pause so that we don't pump all our
842                  * queued console messages into the bitbucket.
843                  */
844
845                 if (time_before(jiffies, atleast)) {
846                         printk(KERN_NOTICE "%s: carrier detect appears"
847                                " untrustworthy, waiting 4 seconds\n",
848                                np->name);
849                         msleep(4000);
850                 }
851         }
852
853         if (!np->local_ip) {
854                 rcu_read_lock();
855                 in_dev = __in_dev_get_rcu(ndev);
856
857                 if (!in_dev || !in_dev->ifa_list) {
858                         rcu_read_unlock();
859                         printk(KERN_ERR "%s: no IP address for %s, aborting\n",
860                                np->name, np->dev_name);
861                         err = -EDESTADDRREQ;
862                         goto put;
863                 }
864
865                 np->local_ip = in_dev->ifa_list->ifa_local;
866                 rcu_read_unlock();
867                 printk(KERN_INFO "%s: local IP %pI4\n", np->name, &np->local_ip);
868         }
869
870         np->dev = ndev;
871
872         /* fill up the skb queue */
873         refill_skbs();
874
875         rtnl_lock();
876         err = __netpoll_setup(np);
877         rtnl_unlock();
878
879         if (err)
880                 goto put;
881
882         return 0;
883
884 put:
885         dev_put(ndev);
886         return err;
887 }
888 EXPORT_SYMBOL(netpoll_setup);
889
890 static int __init netpoll_init(void)
891 {
892         skb_queue_head_init(&skb_pool);
893         return 0;
894 }
895 core_initcall(netpoll_init);
896
897 void __netpoll_cleanup(struct netpoll *np)
898 {
899         struct netpoll_info *npinfo;
900         unsigned long flags;
901
902         npinfo = np->dev->npinfo;
903         if (!npinfo)
904                 return;
905
906         if (!list_empty(&npinfo->rx_np)) {
907                 spin_lock_irqsave(&npinfo->rx_lock, flags);
908                 list_del(&np->rx);
909                 if (list_empty(&npinfo->rx_np))
910                         npinfo->rx_flags &= ~NETPOLL_RX_ENABLED;
911                 spin_unlock_irqrestore(&npinfo->rx_lock, flags);
912         }
913
914         if (atomic_dec_and_test(&npinfo->refcnt)) {
915                 const struct net_device_ops *ops;
916
917                 ops = np->dev->netdev_ops;
918                 if (ops->ndo_netpoll_cleanup)
919                         ops->ndo_netpoll_cleanup(np->dev);
920
921                 rcu_assign_pointer(np->dev->npinfo, NULL);
922
923                 /* avoid racing with NAPI reading npinfo */
924                 synchronize_rcu_bh();
925
926                 skb_queue_purge(&npinfo->arp_tx);
927                 skb_queue_purge(&npinfo->txq);
928                 cancel_rearming_delayed_work(&npinfo->tx_work);
929
930                 /* clean after last, unfinished work */
931                 __skb_queue_purge(&npinfo->txq);
932                 kfree(npinfo);
933         }
934 }
935 EXPORT_SYMBOL_GPL(__netpoll_cleanup);
936
937 void netpoll_cleanup(struct netpoll *np)
938 {
939         if (!np->dev)
940                 return;
941
942         rtnl_lock();
943         __netpoll_cleanup(np);
944         rtnl_unlock();
945
946         dev_put(np->dev);
947         np->dev = NULL;
948 }
949 EXPORT_SYMBOL(netpoll_cleanup);
950
951 int netpoll_trap(void)
952 {
953         return atomic_read(&trapped);
954 }
955 EXPORT_SYMBOL(netpoll_trap);
956
957 void netpoll_set_trap(int trap)
958 {
959         if (trap)
960                 atomic_inc(&trapped);
961         else
962                 atomic_dec(&trapped);
963 }
964 EXPORT_SYMBOL(netpoll_set_trap);