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