blob: 96fb0519eb7a2f50c3677ee3cd30461558e3c698 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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
Linus Torvalds1da177e2005-04-16 15:20:36 -070012#include <linux/netdevice.h>
13#include <linux/etherdevice.h>
14#include <linux/string.h>
Arnaldo Carvalho de Melo14c85022005-12-27 02:43:12 -020015#include <linux/if_arp.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070016#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
Stephen Hemmingera1bcfac2006-11-14 10:43:58 -080037static struct sk_buff_head skb_pool;
Linus Torvalds1da177e2005-04-16 15:20:36 -070038
39static atomic_t trapped;
40
Stephen Hemminger2bdfe0b2006-10-26 15:46:54 -070041#define USEC_PER_POLL 50
David S. Millerd9452e92008-03-04 12:28:49 -080042#define NETPOLL_RX_ENABLED 1
43#define NETPOLL_RX_DROP 2
Linus Torvalds1da177e2005-04-16 15:20:36 -070044
45#define MAX_SKB_SIZE \
46 (MAX_UDP_CHUNK + sizeof(struct udphdr) + \
47 sizeof(struct iphdr) + sizeof(struct ethhdr))
48
49static void zap_completion_queue(void);
Neil Horman068c6e92006-06-26 00:04:27 -070050static void arp_reply(struct sk_buff *skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -070051
David Howellsc4028952006-11-22 14:57:56 +000052static void queue_process(struct work_struct *work)
Linus Torvalds1da177e2005-04-16 15:20:36 -070053{
David Howells4c1ac1b2006-12-05 14:37:56 +000054 struct netpoll_info *npinfo =
55 container_of(work, struct netpoll_info, tx_work.work);
Linus Torvalds1da177e2005-04-16 15:20:36 -070056 struct sk_buff *skb;
Ingo Molnar36405432006-12-12 17:20:42 +010057 unsigned long flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -070058
Stephen Hemminger6c43ff12006-10-26 15:46:53 -070059 while ((skb = skb_dequeue(&npinfo->txq))) {
60 struct net_device *dev = skb->dev;
Stephen Hemminger00829822008-11-20 20:14:53 -080061 const struct net_device_ops *ops = dev->netdev_ops;
David S. Millerfd2ea0a2008-07-17 01:56:23 -070062 struct netdev_queue *txq;
Linus Torvalds1da177e2005-04-16 15:20:36 -070063
Stephen Hemminger6c43ff12006-10-26 15:46:53 -070064 if (!netif_device_present(dev) || !netif_running(dev)) {
65 __kfree_skb(skb);
66 continue;
67 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070068
David S. Millerfd2ea0a2008-07-17 01:56:23 -070069 txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb));
70
Ingo Molnar36405432006-12-12 17:20:42 +010071 local_irq_save(flags);
David S. Millerfd2ea0a2008-07-17 01:56:23 -070072 __netif_tx_lock(txq, smp_processor_id());
73 if (netif_tx_queue_stopped(txq) ||
David S. Millerc3f26a22008-07-31 16:58:50 -070074 netif_tx_queue_frozen(txq) ||
Stephen Hemminger00829822008-11-20 20:14:53 -080075 ops->ndo_start_xmit(skb, dev) != NETDEV_TX_OK) {
Stephen Hemminger6c43ff12006-10-26 15:46:53 -070076 skb_queue_head(&npinfo->txq, skb);
David S. Millerfd2ea0a2008-07-17 01:56:23 -070077 __netif_tx_unlock(txq);
Ingo Molnar36405432006-12-12 17:20:42 +010078 local_irq_restore(flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -070079
Jarek Poplawski25442ca2007-07-05 17:42:44 -070080 schedule_delayed_work(&npinfo->tx_work, HZ/10);
Stephen Hemminger6c43ff12006-10-26 15:46:53 -070081 return;
82 }
David S. Millerfd2ea0a2008-07-17 01:56:23 -070083 __netif_tx_unlock(txq);
Ingo Molnar36405432006-12-12 17:20:42 +010084 local_irq_restore(flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -070085 }
86}
87
Al Virob51655b2006-11-14 21:40:42 -080088static __sum16 checksum_udp(struct sk_buff *skb, struct udphdr *uh,
89 unsigned short ulen, __be32 saddr, __be32 daddr)
Linus Torvalds1da177e2005-04-16 15:20:36 -070090{
Al Virod6f5493c2006-11-14 21:26:08 -080091 __wsum psum;
Herbert Xufb286bb2005-11-10 13:01:24 -080092
Herbert Xu60476372007-04-09 11:59:39 -070093 if (uh->check == 0 || skb_csum_unnecessary(skb))
Linus Torvalds1da177e2005-04-16 15:20:36 -070094 return 0;
95
Herbert Xufb286bb2005-11-10 13:01:24 -080096 psum = csum_tcpudp_nofold(saddr, daddr, ulen, IPPROTO_UDP, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -070097
Patrick McHardy84fa7932006-08-29 16:44:56 -070098 if (skb->ip_summed == CHECKSUM_COMPLETE &&
Al Virod3bc23e2006-11-14 21:24:49 -080099 !csum_fold(csum_add(psum, skb->csum)))
Herbert Xufb286bb2005-11-10 13:01:24 -0800100 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101
Herbert Xufb286bb2005-11-10 13:01:24 -0800102 skb->csum = psum;
103
104 return __skb_checksum_complete(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700105}
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 */
David S. Miller0a7606c2007-10-29 21:28:47 -0700123static 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
David S. Millerd9452e92008-03-04 12:28:49 -0800135 npinfo->rx_flags |= NETPOLL_RX_DROP;
David S. Miller0a7606c2007-10-29 21:28:47 -0700136 atomic_inc(&trapped);
137
138 work = napi->poll(napi, budget);
139
140 atomic_dec(&trapped);
David S. Millerd9452e92008-03-04 12:28:49 -0800141 npinfo->rx_flags &= ~NETPOLL_RX_DROP;
David S. Miller0a7606c2007-10-29 21:28:47 -0700142
143 return budget - work;
144}
145
Stephen Hemminger51069302007-11-19 19:18:11 -0800146static void poll_napi(struct net_device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147{
Stephen Hemmingerbea33482007-10-03 16:41:36 -0700148 struct napi_struct *napi;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149 int budget = 16;
150
Stephen Hemminger51069302007-11-19 19:18:11 -0800151 list_for_each_entry(napi, &dev->napi_list, dev_list) {
David S. Miller0a7606c2007-10-29 21:28:47 -0700152 if (napi->poll_owner != smp_processor_id() &&
Stephen Hemmingerbea33482007-10-03 16:41:36 -0700153 spin_trylock(&napi->poll_lock)) {
Stephen Hemminger51069302007-11-19 19:18:11 -0800154 budget = poll_one_napi(dev->npinfo, napi, budget);
Stephen Hemmingerbea33482007-10-03 16:41:36 -0700155 spin_unlock(&napi->poll_lock);
David S. Miller0a7606c2007-10-29 21:28:47 -0700156
157 if (!budget)
158 break;
Stephen Hemmingerbea33482007-10-03 16:41:36 -0700159 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700160 }
161}
162
Neil Horman068c6e92006-06-26 00:04:27 -0700163static void service_arp_queue(struct netpoll_info *npi)
164{
Stephen Hemminger51069302007-11-19 19:18:11 -0800165 if (npi) {
166 struct sk_buff *skb;
Neil Horman068c6e92006-06-26 00:04:27 -0700167
Stephen Hemminger51069302007-11-19 19:18:11 -0800168 while ((skb = skb_dequeue(&npi->arp_tx)))
169 arp_reply(skb);
Neil Horman068c6e92006-06-26 00:04:27 -0700170 }
Neil Horman068c6e92006-06-26 00:04:27 -0700171}
172
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173void netpoll_poll(struct netpoll *np)
174{
Stephen Hemminger51069302007-11-19 19:18:11 -0800175 struct net_device *dev = np->dev;
Stephen Hemmingerd3147742008-11-19 21:32:24 -0800176 const struct net_device_ops *ops = dev->netdev_ops;
Stephen Hemminger51069302007-11-19 19:18:11 -0800177
Stephen Hemmingerd3147742008-11-19 21:32:24 -0800178 if (!dev || !netif_running(dev) || !ops->ndo_poll_controller)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179 return;
180
181 /* Process pending work on NIC */
Stephen Hemmingerd3147742008-11-19 21:32:24 -0800182 ops->ndo_poll_controller(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183
Stephen Hemminger51069302007-11-19 19:18:11 -0800184 poll_napi(dev);
185
186 service_arp_queue(dev->npinfo);
Neil Horman068c6e92006-06-26 00:04:27 -0700187
Linus Torvalds1da177e2005-04-16 15:20:36 -0700188 zap_completion_queue();
189}
190
191static void refill_skbs(void)
192{
193 struct sk_buff *skb;
194 unsigned long flags;
195
Stephen Hemmingera1bcfac2006-11-14 10:43:58 -0800196 spin_lock_irqsave(&skb_pool.lock, flags);
197 while (skb_pool.qlen < MAX_SKBS) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198 skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC);
199 if (!skb)
200 break;
201
Stephen Hemmingera1bcfac2006-11-14 10:43:58 -0800202 __skb_queue_tail(&skb_pool, skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203 }
Stephen Hemmingera1bcfac2006-11-14 10:43:58 -0800204 spin_unlock_irqrestore(&skb_pool.lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205}
206
207static void zap_completion_queue(void)
208{
209 unsigned long flags;
210 struct softnet_data *sd = &get_cpu_var(softnet_data);
211
212 if (sd->completion_queue) {
213 struct sk_buff *clist;
214
215 local_irq_save(flags);
216 clist = sd->completion_queue;
217 sd->completion_queue = NULL;
218 local_irq_restore(flags);
219
220 while (clist != NULL) {
221 struct sk_buff *skb = clist;
222 clist = clist->next;
Jarek Poplawski8a455b02008-03-20 16:07:27 -0700223 if (skb->destructor) {
224 atomic_inc(&skb->users);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225 dev_kfree_skb_any(skb); /* put this one back */
Jarek Poplawski8a455b02008-03-20 16:07:27 -0700226 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227 __kfree_skb(skb);
Jarek Poplawski8a455b02008-03-20 16:07:27 -0700228 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229 }
230 }
231
232 put_cpu_var(softnet_data);
233}
234
Stephen Hemmingera1bcfac2006-11-14 10:43:58 -0800235static struct sk_buff *find_skb(struct netpoll *np, int len, int reserve)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236{
Stephen Hemmingera1bcfac2006-11-14 10:43:58 -0800237 int count = 0;
238 struct sk_buff *skb;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700239
240 zap_completion_queue();
Stephen Hemmingera1bcfac2006-11-14 10:43:58 -0800241 refill_skbs();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242repeat:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700243
244 skb = alloc_skb(len, GFP_ATOMIC);
Stephen Hemmingera1bcfac2006-11-14 10:43:58 -0800245 if (!skb)
246 skb = skb_dequeue(&skb_pool);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247
248 if (!skb) {
Stephen Hemmingera1bcfac2006-11-14 10:43:58 -0800249 if (++count < 10) {
250 netpoll_poll(np);
251 goto repeat;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252 }
Stephen Hemmingera1bcfac2006-11-14 10:43:58 -0800253 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254 }
255
256 atomic_set(&skb->users, 1);
257 skb_reserve(skb, reserve);
258 return skb;
259}
260
Stephen Hemmingerbea33482007-10-03 16:41:36 -0700261static int netpoll_owner_active(struct net_device *dev)
262{
263 struct napi_struct *napi;
264
265 list_for_each_entry(napi, &dev->napi_list, dev_list) {
266 if (napi->poll_owner == smp_processor_id())
267 return 1;
268 }
269 return 0;
270}
271
Linus Torvalds1da177e2005-04-16 15:20:36 -0700272static void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
273{
Stephen Hemminger2bdfe0b2006-10-26 15:46:54 -0700274 int status = NETDEV_TX_BUSY;
275 unsigned long tries;
YOSHIFUJI Hideaki4ec93ed2007-02-09 23:24:36 +0900276 struct net_device *dev = np->dev;
Stephen Hemminger00829822008-11-20 20:14:53 -0800277 const struct net_device_ops *ops = dev->netdev_ops;
YOSHIFUJI Hideaki4ec93ed2007-02-09 23:24:36 +0900278 struct netpoll_info *npinfo = np->dev->npinfo;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279
YOSHIFUJI Hideaki4ec93ed2007-02-09 23:24:36 +0900280 if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) {
281 __kfree_skb(skb);
282 return;
283 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700284
Stephen Hemminger2bdfe0b2006-10-26 15:46:54 -0700285 /* don't get messages out of order, and no recursion */
Stephen Hemmingerbea33482007-10-03 16:41:36 -0700286 if (skb_queue_len(&npinfo->txq) == 0 && !netpoll_owner_active(dev)) {
David S. Millerfd2ea0a2008-07-17 01:56:23 -0700287 struct netdev_queue *txq;
Andrew Mortona49f99f2006-12-11 17:24:46 -0800288 unsigned long flags;
289
David S. Millerfd2ea0a2008-07-17 01:56:23 -0700290 txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb));
291
Andrew Mortona49f99f2006-12-11 17:24:46 -0800292 local_irq_save(flags);
Stephen Hemminger0db3dc72007-06-27 00:39:42 -0700293 /* try until next clock tick */
294 for (tries = jiffies_to_usecs(1)/USEC_PER_POLL;
295 tries > 0; --tries) {
David S. Millerfd2ea0a2008-07-17 01:56:23 -0700296 if (__netif_tx_trylock(txq)) {
297 if (!netif_tx_queue_stopped(txq))
Stephen Hemminger00829822008-11-20 20:14:53 -0800298 status = ops->ndo_start_xmit(skb, dev);
David S. Millerfd2ea0a2008-07-17 01:56:23 -0700299 __netif_tx_unlock(txq);
Matt Mackallf0d34592005-08-11 19:25:11 -0700300
Andrew Mortone37b8d92006-12-09 14:01:49 -0800301 if (status == NETDEV_TX_OK)
302 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700303
Andrew Mortone37b8d92006-12-09 14:01:49 -0800304 }
Stephen Hemminger0db3dc72007-06-27 00:39:42 -0700305
306 /* tickle device maybe there is some cleanup */
307 netpoll_poll(np);
308
309 udelay(USEC_PER_POLL);
Matt Mackall0db1d6f2005-08-11 19:25:54 -0700310 }
Andrew Mortona49f99f2006-12-11 17:24:46 -0800311 local_irq_restore(flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700312 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700313
Stephen Hemminger2bdfe0b2006-10-26 15:46:54 -0700314 if (status != NETDEV_TX_OK) {
Stephen Hemminger5de4a472006-10-26 15:46:55 -0700315 skb_queue_tail(&npinfo->txq, skb);
David Howells4c1ac1b2006-12-05 14:37:56 +0000316 schedule_delayed_work(&npinfo->tx_work,0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700317 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700318}
319
320void netpoll_send_udp(struct netpoll *np, const char *msg, int len)
321{
322 int total_len, eth_len, ip_len, udp_len;
323 struct sk_buff *skb;
324 struct udphdr *udph;
325 struct iphdr *iph;
326 struct ethhdr *eth;
327
328 udp_len = len + sizeof(*udph);
329 ip_len = eth_len = udp_len + sizeof(*iph);
330 total_len = eth_len + ETH_HLEN + NET_IP_ALIGN;
331
332 skb = find_skb(np, total_len, total_len - len);
333 if (!skb)
334 return;
335
Arnaldo Carvalho de Melo27d7ff42007-03-31 11:55:19 -0300336 skb_copy_to_linear_data(skb, msg, len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700337 skb->len += len;
338
Arnaldo Carvalho de Melo4bedb452007-03-13 14:28:48 -0300339 skb_push(skb, sizeof(*udph));
340 skb_reset_transport_header(skb);
341 udph = udp_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700342 udph->source = htons(np->local_port);
343 udph->dest = htons(np->remote_port);
344 udph->len = htons(udp_len);
345 udph->check = 0;
Chris Lalancette8e365ee2006-11-07 14:56:19 -0800346 udph->check = csum_tcpudp_magic(htonl(np->local_ip),
347 htonl(np->remote_ip),
348 udp_len, IPPROTO_UDP,
Joe Perches07f07572008-11-19 15:44:53 -0800349 csum_partial(udph, udp_len, 0));
Chris Lalancette8e365ee2006-11-07 14:56:19 -0800350 if (udph->check == 0)
Al Viro5e57dff2006-11-20 18:08:13 -0800351 udph->check = CSUM_MANGLED_0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700352
Arnaldo Carvalho de Meloe2d1bca2007-04-10 20:46:21 -0700353 skb_push(skb, sizeof(*iph));
354 skb_reset_network_header(skb);
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700355 iph = ip_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700356
357 /* iph->version = 4; iph->ihl = 5; */
358 put_unaligned(0x45, (unsigned char *)iph);
359 iph->tos = 0;
360 put_unaligned(htons(ip_len), &(iph->tot_len));
361 iph->id = 0;
362 iph->frag_off = 0;
363 iph->ttl = 64;
364 iph->protocol = IPPROTO_UDP;
365 iph->check = 0;
366 put_unaligned(htonl(np->local_ip), &(iph->saddr));
367 put_unaligned(htonl(np->remote_ip), &(iph->daddr));
368 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl);
369
370 eth = (struct ethhdr *) skb_push(skb, ETH_HLEN);
Arnaldo Carvalho de Melo459a98e2007-03-19 15:30:44 -0700371 skb_reset_mac_header(skb);
Stephen Hemminger206daaf2006-10-19 23:58:23 -0700372 skb->protocol = eth->h_proto = htons(ETH_P_IP);
Stephen Hemminger09538642007-11-19 19:23:29 -0800373 memcpy(eth->h_source, np->dev->dev_addr, ETH_ALEN);
374 memcpy(eth->h_dest, np->remote_mac, ETH_ALEN);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700375
376 skb->dev = np->dev;
377
378 netpoll_send_skb(np, skb);
379}
380
381static void arp_reply(struct sk_buff *skb)
382{
Jeff Moyer115c1d62005-06-22 22:05:31 -0700383 struct netpoll_info *npinfo = skb->dev->npinfo;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700384 struct arphdr *arp;
385 unsigned char *arp_ptr;
386 int size, type = ARPOP_REPLY, ptype = ETH_P_ARP;
Al Viro252e3342006-11-14 20:48:11 -0800387 __be32 sip, tip;
Neil Horman47bbec02006-12-08 00:05:55 -0800388 unsigned char *sha;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700389 struct sk_buff *send_skb;
Jeff Moyer115c1d62005-06-22 22:05:31 -0700390 struct netpoll *np = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700391
Jeff Moyerfbeec2e2005-06-22 22:05:59 -0700392 if (npinfo->rx_np && npinfo->rx_np->dev == skb->dev)
393 np = npinfo->rx_np;
Jeff Moyer115c1d62005-06-22 22:05:31 -0700394 if (!np)
395 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700396
397 /* No arp on this interface */
398 if (skb->dev->flags & IFF_NOARP)
399 return;
400
Pavel Emelyanov988b7052008-03-03 12:20:57 -0800401 if (!pskb_may_pull(skb, arp_hdr_len(skb->dev)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700402 return;
403
Arnaldo Carvalho de Meloc1d2bbe2007-04-10 20:45:18 -0700404 skb_reset_network_header(skb);
Arnaldo Carvalho de Melobadff6d2007-03-13 13:06:52 -0300405 skb_reset_transport_header(skb);
Arnaldo Carvalho de Melod0a92be2007-03-12 20:56:31 -0300406 arp = arp_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700407
408 if ((arp->ar_hrd != htons(ARPHRD_ETHER) &&
409 arp->ar_hrd != htons(ARPHRD_IEEE802)) ||
410 arp->ar_pro != htons(ETH_P_IP) ||
411 arp->ar_op != htons(ARPOP_REQUEST))
412 return;
413
Neil Horman47bbec02006-12-08 00:05:55 -0800414 arp_ptr = (unsigned char *)(arp+1);
415 /* save the location of the src hw addr */
416 sha = arp_ptr;
417 arp_ptr += skb->dev->addr_len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700418 memcpy(&sip, arp_ptr, 4);
Neil Horman47bbec02006-12-08 00:05:55 -0800419 arp_ptr += 4;
420 /* if we actually cared about dst hw addr, it would get copied here */
421 arp_ptr += skb->dev->addr_len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700422 memcpy(&tip, arp_ptr, 4);
423
424 /* Should we ignore arp? */
Joe Perches21cf2252007-12-16 13:44:00 -0800425 if (tip != htonl(np->local_ip) ||
426 ipv4_is_loopback(tip) || ipv4_is_multicast(tip))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700427 return;
428
Pavel Emelyanov988b7052008-03-03 12:20:57 -0800429 size = arp_hdr_len(skb->dev);
Johannes Bergf5184d22008-05-12 20:48:31 -0700430 send_skb = find_skb(np, size + LL_ALLOCATED_SPACE(np->dev),
Linus Torvalds1da177e2005-04-16 15:20:36 -0700431 LL_RESERVED_SPACE(np->dev));
432
433 if (!send_skb)
434 return;
435
Arnaldo Carvalho de Meloc1d2bbe2007-04-10 20:45:18 -0700436 skb_reset_network_header(send_skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700437 arp = (struct arphdr *) skb_put(send_skb, size);
438 send_skb->dev = skb->dev;
439 send_skb->protocol = htons(ETH_P_ARP);
440
441 /* Fill the device header for the ARP frame */
Stephen Hemminger0c4e8582007-10-09 01:36:32 -0700442 if (dev_hard_header(send_skb, skb->dev, ptype,
Stephen Hemminger09538642007-11-19 19:23:29 -0800443 sha, np->dev->dev_addr,
Stephen Hemminger0c4e8582007-10-09 01:36:32 -0700444 send_skb->len) < 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700445 kfree_skb(send_skb);
446 return;
447 }
448
449 /*
450 * Fill out the arp protocol part.
451 *
452 * we only support ethernet device type,
453 * which (according to RFC 1390) should always equal 1 (Ethernet).
454 */
455
456 arp->ar_hrd = htons(np->dev->type);
457 arp->ar_pro = htons(ETH_P_IP);
458 arp->ar_hln = np->dev->addr_len;
459 arp->ar_pln = 4;
460 arp->ar_op = htons(type);
461
462 arp_ptr=(unsigned char *)(arp + 1);
463 memcpy(arp_ptr, np->dev->dev_addr, np->dev->addr_len);
464 arp_ptr += np->dev->addr_len;
465 memcpy(arp_ptr, &tip, 4);
466 arp_ptr += 4;
Neil Horman47bbec02006-12-08 00:05:55 -0800467 memcpy(arp_ptr, sha, np->dev->addr_len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700468 arp_ptr += np->dev->addr_len;
469 memcpy(arp_ptr, &sip, 4);
470
471 netpoll_send_skb(np, send_skb);
472}
473
474int __netpoll_rx(struct sk_buff *skb)
475{
476 int proto, len, ulen;
477 struct iphdr *iph;
478 struct udphdr *uh;
Neil Horman068c6e92006-06-26 00:04:27 -0700479 struct netpoll_info *npi = skb->dev->npinfo;
480 struct netpoll *np = npi->rx_np;
481
Jeff Moyerfbeec2e2005-06-22 22:05:59 -0700482 if (!np)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700483 goto out;
484 if (skb->dev->type != ARPHRD_ETHER)
485 goto out;
486
David S. Millerd9452e92008-03-04 12:28:49 -0800487 /* check if netpoll clients need ARP */
YOSHIFUJI Hideaki724800d2007-03-25 20:13:04 -0700488 if (skb->protocol == htons(ETH_P_ARP) &&
Linus Torvalds1da177e2005-04-16 15:20:36 -0700489 atomic_read(&trapped)) {
Neil Horman068c6e92006-06-26 00:04:27 -0700490 skb_queue_tail(&npi->arp_tx, skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700491 return 1;
492 }
493
494 proto = ntohs(eth_hdr(skb)->h_proto);
495 if (proto != ETH_P_IP)
496 goto out;
497 if (skb->pkt_type == PACKET_OTHERHOST)
498 goto out;
499 if (skb_shared(skb))
500 goto out;
501
502 iph = (struct iphdr *)skb->data;
503 if (!pskb_may_pull(skb, sizeof(struct iphdr)))
504 goto out;
505 if (iph->ihl < 5 || iph->version != 4)
506 goto out;
507 if (!pskb_may_pull(skb, iph->ihl*4))
508 goto out;
509 if (ip_fast_csum((u8 *)iph, iph->ihl) != 0)
510 goto out;
511
512 len = ntohs(iph->tot_len);
513 if (skb->len < len || len < iph->ihl*4)
514 goto out;
515
Aubrey.Li5e7d7fa2007-04-17 12:40:20 -0700516 /*
517 * Our transport medium may have padded the buffer out.
518 * Now We trim to the true length of the frame.
519 */
520 if (pskb_trim_rcsum(skb, len))
521 goto out;
522
Linus Torvalds1da177e2005-04-16 15:20:36 -0700523 if (iph->protocol != IPPROTO_UDP)
524 goto out;
525
526 len -= iph->ihl*4;
527 uh = (struct udphdr *)(((char *)iph) + iph->ihl*4);
528 ulen = ntohs(uh->len);
529
530 if (ulen != len)
531 goto out;
Herbert Xufb286bb2005-11-10 13:01:24 -0800532 if (checksum_udp(skb, uh, ulen, iph->saddr, iph->daddr))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700533 goto out;
534 if (np->local_ip && np->local_ip != ntohl(iph->daddr))
535 goto out;
536 if (np->remote_ip && np->remote_ip != ntohl(iph->saddr))
537 goto out;
538 if (np->local_port && np->local_port != ntohs(uh->dest))
539 goto out;
540
541 np->rx_hook(np, ntohs(uh->source),
542 (char *)(uh+1),
543 ulen - sizeof(struct udphdr));
544
545 kfree_skb(skb);
546 return 1;
547
548out:
549 if (atomic_read(&trapped)) {
550 kfree_skb(skb);
551 return 1;
552 }
553
554 return 0;
555}
556
Satyam Sharma0bcc1812007-08-10 15:35:05 -0700557void netpoll_print_options(struct netpoll *np)
558{
559 printk(KERN_INFO "%s: local port %d\n",
560 np->name, np->local_port);
561 printk(KERN_INFO "%s: local IP %d.%d.%d.%d\n",
562 np->name, HIPQUAD(np->local_ip));
563 printk(KERN_INFO "%s: interface %s\n",
564 np->name, np->dev_name);
565 printk(KERN_INFO "%s: remote port %d\n",
566 np->name, np->remote_port);
567 printk(KERN_INFO "%s: remote IP %d.%d.%d.%d\n",
568 np->name, HIPQUAD(np->remote_ip));
Johannes Berge1749612008-10-27 15:59:26 -0700569 printk(KERN_INFO "%s: remote ethernet address %pM\n",
570 np->name, np->remote_mac);
Satyam Sharma0bcc1812007-08-10 15:35:05 -0700571}
572
Linus Torvalds1da177e2005-04-16 15:20:36 -0700573int netpoll_parse_options(struct netpoll *np, char *opt)
574{
575 char *cur=opt, *delim;
576
David S. Millerc68b9072006-11-14 20:40:49 -0800577 if (*cur != '@') {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700578 if ((delim = strchr(cur, '@')) == NULL)
579 goto parse_failed;
David S. Millerc68b9072006-11-14 20:40:49 -0800580 *delim = 0;
581 np->local_port = simple_strtol(cur, NULL, 10);
582 cur = delim;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700583 }
584 cur++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700585
David S. Millerc68b9072006-11-14 20:40:49 -0800586 if (*cur != '/') {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700587 if ((delim = strchr(cur, '/')) == NULL)
588 goto parse_failed;
David S. Millerc68b9072006-11-14 20:40:49 -0800589 *delim = 0;
590 np->local_ip = ntohl(in_aton(cur));
591 cur = delim;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700592 }
593 cur++;
594
David S. Millerc68b9072006-11-14 20:40:49 -0800595 if (*cur != ',') {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700596 /* parse out dev name */
597 if ((delim = strchr(cur, ',')) == NULL)
598 goto parse_failed;
David S. Millerc68b9072006-11-14 20:40:49 -0800599 *delim = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700600 strlcpy(np->dev_name, cur, sizeof(np->dev_name));
David S. Millerc68b9072006-11-14 20:40:49 -0800601 cur = delim;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700602 }
603 cur++;
604
David S. Millerc68b9072006-11-14 20:40:49 -0800605 if (*cur != '@') {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700606 /* dst port */
607 if ((delim = strchr(cur, '@')) == NULL)
608 goto parse_failed;
David S. Millerc68b9072006-11-14 20:40:49 -0800609 *delim = 0;
610 np->remote_port = simple_strtol(cur, NULL, 10);
611 cur = delim;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700612 }
613 cur++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700614
615 /* dst ip */
616 if ((delim = strchr(cur, '/')) == NULL)
617 goto parse_failed;
David S. Millerc68b9072006-11-14 20:40:49 -0800618 *delim = 0;
619 np->remote_ip = ntohl(in_aton(cur));
620 cur = delim + 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700621
David S. Millerc68b9072006-11-14 20:40:49 -0800622 if (*cur != 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700623 /* MAC address */
624 if ((delim = strchr(cur, ':')) == NULL)
625 goto parse_failed;
David S. Millerc68b9072006-11-14 20:40:49 -0800626 *delim = 0;
627 np->remote_mac[0] = simple_strtol(cur, NULL, 16);
628 cur = delim + 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700629 if ((delim = strchr(cur, ':')) == NULL)
630 goto parse_failed;
David S. Millerc68b9072006-11-14 20:40:49 -0800631 *delim = 0;
632 np->remote_mac[1] = simple_strtol(cur, NULL, 16);
633 cur = delim + 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700634 if ((delim = strchr(cur, ':')) == NULL)
635 goto parse_failed;
David S. Millerc68b9072006-11-14 20:40:49 -0800636 *delim = 0;
637 np->remote_mac[2] = simple_strtol(cur, NULL, 16);
638 cur = delim + 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700639 if ((delim = strchr(cur, ':')) == NULL)
640 goto parse_failed;
David S. Millerc68b9072006-11-14 20:40:49 -0800641 *delim = 0;
642 np->remote_mac[3] = simple_strtol(cur, NULL, 16);
643 cur = delim + 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700644 if ((delim = strchr(cur, ':')) == NULL)
645 goto parse_failed;
David S. Millerc68b9072006-11-14 20:40:49 -0800646 *delim = 0;
647 np->remote_mac[4] = simple_strtol(cur, NULL, 16);
648 cur = delim + 1;
649 np->remote_mac[5] = simple_strtol(cur, NULL, 16);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700650 }
651
Satyam Sharma0bcc1812007-08-10 15:35:05 -0700652 netpoll_print_options(np);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700653
654 return 0;
655
656 parse_failed:
657 printk(KERN_INFO "%s: couldn't parse config at %s!\n",
658 np->name, cur);
659 return -1;
660}
661
662int netpoll_setup(struct netpoll *np)
663{
664 struct net_device *ndev = NULL;
665 struct in_device *in_dev;
Jeff Moyer115c1d62005-06-22 22:05:31 -0700666 struct netpoll_info *npinfo;
Jeff Moyerfbeec2e2005-06-22 22:05:59 -0700667 unsigned long flags;
Stephen Hemmingerb41848b2006-10-26 15:46:52 -0700668 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700669
670 if (np->dev_name)
Eric W. Biederman881d9662007-09-17 11:56:21 -0700671 ndev = dev_get_by_name(&init_net, np->dev_name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700672 if (!ndev) {
673 printk(KERN_ERR "%s: %s doesn't exist, aborting.\n",
674 np->name, np->dev_name);
Stephen Hemmingerb41848b2006-10-26 15:46:52 -0700675 return -ENODEV;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700676 }
677
678 np->dev = ndev;
Jeff Moyer115c1d62005-06-22 22:05:31 -0700679 if (!ndev->npinfo) {
680 npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL);
Stephen Hemmingerb41848b2006-10-26 15:46:52 -0700681 if (!npinfo) {
682 err = -ENOMEM;
Jeff Moyer115c1d62005-06-22 22:05:31 -0700683 goto release;
Stephen Hemmingerb41848b2006-10-26 15:46:52 -0700684 }
Jeff Moyer115c1d62005-06-22 22:05:31 -0700685
David S. Millerd9452e92008-03-04 12:28:49 -0800686 npinfo->rx_flags = 0;
Jeff Moyerfbeec2e2005-06-22 22:05:59 -0700687 npinfo->rx_np = NULL;
Stephen Hemminger2bdfe0b2006-10-26 15:46:54 -0700688
Ingo Molnara9f6a0d2005-09-09 13:10:41 -0700689 spin_lock_init(&npinfo->rx_lock);
Neil Horman068c6e92006-06-26 00:04:27 -0700690 skb_queue_head_init(&npinfo->arp_tx);
Stephen Hemmingerb6cd27e2006-10-26 15:46:51 -0700691 skb_queue_head_init(&npinfo->txq);
David Howells4c1ac1b2006-12-05 14:37:56 +0000692 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process);
Stephen Hemmingerb6cd27e2006-10-26 15:46:51 -0700693
Stephen Hemminger93ec2c72006-10-26 15:46:50 -0700694 atomic_set(&npinfo->refcnt, 1);
695 } else {
Jeff Moyer115c1d62005-06-22 22:05:31 -0700696 npinfo = ndev->npinfo;
Stephen Hemminger93ec2c72006-10-26 15:46:50 -0700697 atomic_inc(&npinfo->refcnt);
698 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700699
Stephen Hemmingerd3147742008-11-19 21:32:24 -0800700 if (!ndev->netdev_ops->ndo_poll_controller) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700701 printk(KERN_ERR "%s: %s doesn't support polling, aborting.\n",
702 np->name, np->dev_name);
Stephen Hemmingerb41848b2006-10-26 15:46:52 -0700703 err = -ENOTSUPP;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700704 goto release;
705 }
706
707 if (!netif_running(ndev)) {
708 unsigned long atmost, atleast;
709
710 printk(KERN_INFO "%s: device %s not up yet, forcing it\n",
711 np->name, np->dev_name);
712
Stephen Hemminger6756ae42006-03-20 22:23:58 -0800713 rtnl_lock();
Stephen Hemmingerb41848b2006-10-26 15:46:52 -0700714 err = dev_open(ndev);
715 rtnl_unlock();
716
717 if (err) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700718 printk(KERN_ERR "%s: failed to open %s\n",
Stephen Hemmingerb41848b2006-10-26 15:46:52 -0700719 np->name, ndev->name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700720 goto release;
721 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700722
723 atleast = jiffies + HZ/10;
YOSHIFUJI Hideaki4ec93ed2007-02-09 23:24:36 +0900724 atmost = jiffies + 4*HZ;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700725 while (!netif_carrier_ok(ndev)) {
726 if (time_after(jiffies, atmost)) {
727 printk(KERN_NOTICE
728 "%s: timeout waiting for carrier\n",
729 np->name);
730 break;
731 }
732 cond_resched();
733 }
734
735 /* If carrier appears to come up instantly, we don't
736 * trust it and pause so that we don't pump all our
737 * queued console messages into the bitbucket.
738 */
739
740 if (time_before(jiffies, atleast)) {
741 printk(KERN_NOTICE "%s: carrier detect appears"
742 " untrustworthy, waiting 4 seconds\n",
743 np->name);
744 msleep(4000);
745 }
746 }
747
Linus Torvalds1da177e2005-04-16 15:20:36 -0700748 if (!np->local_ip) {
749 rcu_read_lock();
Herbert Xue5ed6392005-10-03 14:35:55 -0700750 in_dev = __in_dev_get_rcu(ndev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700751
752 if (!in_dev || !in_dev->ifa_list) {
753 rcu_read_unlock();
754 printk(KERN_ERR "%s: no IP address for %s, aborting\n",
755 np->name, np->dev_name);
Stephen Hemmingerb41848b2006-10-26 15:46:52 -0700756 err = -EDESTADDRREQ;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700757 goto release;
758 }
759
760 np->local_ip = ntohl(in_dev->ifa_list->ifa_local);
761 rcu_read_unlock();
762 printk(KERN_INFO "%s: local IP %d.%d.%d.%d\n",
763 np->name, HIPQUAD(np->local_ip));
764 }
765
Jeff Moyerfbeec2e2005-06-22 22:05:59 -0700766 if (np->rx_hook) {
767 spin_lock_irqsave(&npinfo->rx_lock, flags);
David S. Millerd9452e92008-03-04 12:28:49 -0800768 npinfo->rx_flags |= NETPOLL_RX_ENABLED;
Jeff Moyerfbeec2e2005-06-22 22:05:59 -0700769 npinfo->rx_np = np;
770 spin_unlock_irqrestore(&npinfo->rx_lock, flags);
771 }
Ingo Molnar26520762005-08-11 19:26:42 -0700772
773 /* fill up the skb queue */
774 refill_skbs();
775
Jeff Moyerfbeec2e2005-06-22 22:05:59 -0700776 /* last thing to do is link it to the net device structure */
Jeff Moyer115c1d62005-06-22 22:05:31 -0700777 ndev->npinfo = npinfo;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700778
Matt Mackall53fb95d2005-08-11 19:27:43 -0700779 /* avoid racing with NAPI reading npinfo */
780 synchronize_rcu();
781
Linus Torvalds1da177e2005-04-16 15:20:36 -0700782 return 0;
783
784 release:
Jeff Moyer115c1d62005-06-22 22:05:31 -0700785 if (!ndev->npinfo)
786 kfree(npinfo);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700787 np->dev = NULL;
788 dev_put(ndev);
Stephen Hemmingerb41848b2006-10-26 15:46:52 -0700789 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700790}
791
David S. Millerc68b9072006-11-14 20:40:49 -0800792static int __init netpoll_init(void)
793{
Stephen Hemmingera1bcfac2006-11-14 10:43:58 -0800794 skb_queue_head_init(&skb_pool);
795 return 0;
796}
797core_initcall(netpoll_init);
798
Linus Torvalds1da177e2005-04-16 15:20:36 -0700799void netpoll_cleanup(struct netpoll *np)
800{
Jeff Moyerfbeec2e2005-06-22 22:05:59 -0700801 struct netpoll_info *npinfo;
802 unsigned long flags;
803
Jeff Moyer115c1d62005-06-22 22:05:31 -0700804 if (np->dev) {
Jeff Moyerfbeec2e2005-06-22 22:05:59 -0700805 npinfo = np->dev->npinfo;
Stephen Hemminger93ec2c72006-10-26 15:46:50 -0700806 if (npinfo) {
807 if (npinfo->rx_np == np) {
808 spin_lock_irqsave(&npinfo->rx_lock, flags);
809 npinfo->rx_np = NULL;
David S. Millerd9452e92008-03-04 12:28:49 -0800810 npinfo->rx_flags &= ~NETPOLL_RX_ENABLED;
Stephen Hemminger93ec2c72006-10-26 15:46:50 -0700811 spin_unlock_irqrestore(&npinfo->rx_lock, flags);
812 }
813
Stephen Hemminger93ec2c72006-10-26 15:46:50 -0700814 if (atomic_dec_and_test(&npinfo->refcnt)) {
815 skb_queue_purge(&npinfo->arp_tx);
YOSHIFUJI Hideaki4ec93ed2007-02-09 23:24:36 +0900816 skb_queue_purge(&npinfo->txq);
Jarek Poplawski25442ca2007-07-05 17:42:44 -0700817 cancel_rearming_delayed_work(&npinfo->tx_work);
Stephen Hemminger93ec2c72006-10-26 15:46:50 -0700818
Jarek Poplawski17200812007-06-28 22:11:47 -0700819 /* clean after last, unfinished work */
Stephen Hemminger0adc9ad2007-11-19 19:15:03 -0800820 __skb_queue_purge(&npinfo->txq);
Stephen Hemminger93ec2c72006-10-26 15:46:50 -0700821 kfree(npinfo);
Satyam Sharma1498b3f2007-07-09 15:22:23 -0700822 np->dev->npinfo = NULL;
Stephen Hemminger93ec2c72006-10-26 15:46:50 -0700823 }
Jeff Moyerfbeec2e2005-06-22 22:05:59 -0700824 }
Stephen Hemminger93ec2c72006-10-26 15:46:50 -0700825
Jeff Moyer115c1d62005-06-22 22:05:31 -0700826 dev_put(np->dev);
827 }
Jeff Moyerfbeec2e2005-06-22 22:05:59 -0700828
Linus Torvalds1da177e2005-04-16 15:20:36 -0700829 np->dev = NULL;
830}
831
832int netpoll_trap(void)
833{
834 return atomic_read(&trapped);
835}
836
837void netpoll_set_trap(int trap)
838{
839 if (trap)
840 atomic_inc(&trapped);
841 else
842 atomic_dec(&trapped);
843}
844
845EXPORT_SYMBOL(netpoll_set_trap);
846EXPORT_SYMBOL(netpoll_trap);
Satyam Sharma0bcc1812007-08-10 15:35:05 -0700847EXPORT_SYMBOL(netpoll_print_options);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700848EXPORT_SYMBOL(netpoll_parse_options);
849EXPORT_SYMBOL(netpoll_setup);
850EXPORT_SYMBOL(netpoll_cleanup);
851EXPORT_SYMBOL(netpoll_send_udp);
852EXPORT_SYMBOL(netpoll_poll);