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/smp_lock.h>
  13 #include <linux/netdevice.h>
  14 #include <linux/etherdevice.h>
  15 #include <linux/string.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/rcupdate.h>
  22 #include <net/tcp.h>
  23 #include <net/udp.h>
  24 #include <asm/unaligned.h>
  25
  26 /*
  27  * We maintain a small pool of fully-sized skbs, to make sure the
  28  * message gets out even in extreme OOM situations.
  29  */
  30
  31 #define MAX_SKBS 32
  32 #define MAX_UDP_CHUNK 1460
  33
  34 static DEFINE_SPINLOCK(skb_list_lock);
  35 static int nr_skbs;
  36 static struct sk_buff *skbs;
  37
  38 static DEFINE_SPINLOCK(rx_list_lock);
  39 static LIST_HEAD(rx_list);
  40
  41 static atomic_t trapped;
  42 static DEFINE_SPINLOCK(netpoll_poll_lock);
  43
  44 #define NETPOLL_RX_ENABLED  1
  45 #define NETPOLL_RX_DROP     2
  46
  47 #define MAX_SKB_SIZE \
  48                 (MAX_UDP_CHUNK + sizeof(struct udphdr) + \
  49                                 sizeof(struct iphdr) + sizeof(struct ethhdr))
  50
  51 static void zap_completion_queue(void);
  52
  53 static int checksum_udp(struct sk_buff *skb, struct udphdr *uh,
  54                              unsigned short ulen, u32 saddr, u32 daddr)
  55 {
  56         if (uh->check == 0)
  57                 return 0;
  58
  59         if (skb->ip_summed == CHECKSUM_HW)
  60                 return csum_tcpudp_magic(
  61                         saddr, daddr, ulen, IPPROTO_UDP, skb->csum);
  62
  63         skb->csum = csum_tcpudp_nofold(saddr, daddr, ulen, IPPROTO_UDP, 0);
  64
  65         return csum_fold(skb_checksum(skb, 0, skb->len, skb->csum));
  66 }
  67
  68 /*
  69  * Check whether delayed processing was scheduled for our current CPU,
  70  * and then manually invoke NAPI polling to pump data off the card.
  71  *
  72  * In cases where there is bi-directional communications, reading only
  73  * one message at a time can lead to packets being dropped by the
  74  * network adapter, forcing superfluous retries and possibly timeouts.
  75  * Thus, we set our budget to greater than 1.
  76  */
  77 static void poll_napi(struct netpoll *np)
  78 {
  79         int budget = 16;
  80         unsigned long flags;
  81         struct softnet_data *queue;
  82
  83         spin_lock_irqsave(&netpoll_poll_lock, flags);
  84         queue = &__get_cpu_var(softnet_data);
  85         if (test_bit(__LINK_STATE_RX_SCHED, &np->dev->state) &&
  86             !list_empty(&queue->poll_list)) {
  87                 np->dev->netpoll_rx |= NETPOLL_RX_DROP;
  88                 atomic_inc(&trapped);
  89
  90                 np->dev->poll(np->dev, &budget);
  91
  92                 atomic_dec(&trapped);
  93                 np->dev->netpoll_rx &= ~NETPOLL_RX_DROP;
  94         }
  95         spin_unlock_irqrestore(&netpoll_poll_lock, flags);
  96 }
  97
  98 void netpoll_poll(struct netpoll *np)
  99 {
 100         if(!np->dev || !netif_running(np->dev) || !np->dev->poll_controller)
 101                 return;
 102
 103         /* Process pending work on NIC */
 104         np->dev->poll_controller(np->dev);
 105         if (np->dev->poll)
 106                 poll_napi(np);
 107
 108         zap_completion_queue();
 109 }
 110
 111 static void refill_skbs(void)
 112 {
 113         struct sk_buff *skb;
 114         unsigned long flags;
 115
 116         spin_lock_irqsave(&skb_list_lock, flags);
 117         while (nr_skbs < MAX_SKBS) {
 118                 skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC);
 119                 if (!skb)
 120                         break;
 121
 122                 skb->next = skbs;
 123                 skbs = skb;
 124                 nr_skbs++;
 125         }
 126         spin_unlock_irqrestore(&skb_list_lock, flags);
 127 }
 128
 129 static void zap_completion_queue(void)
 130 {
 131         unsigned long flags;
 132         struct softnet_data *sd = &get_cpu_var(softnet_data);
 133
 134         if (sd->completion_queue) {
 135                 struct sk_buff *clist;
 136
 137                 local_irq_save(flags);
 138                 clist = sd->completion_queue;
 139                 sd->completion_queue = NULL;
 140                 local_irq_restore(flags);
 141
 142                 while (clist != NULL) {
 143                         struct sk_buff *skb = clist;
 144                         clist = clist->next;
 145                         __kfree_skb(skb);
 146                 }
 147         }
 148
 149         put_cpu_var(softnet_data);
 150 }
 151
 152 static struct sk_buff * find_skb(struct netpoll *np, int len, int reserve)
 153 {
 154         int once = 1, count = 0;
 155         unsigned long flags;
 156         struct sk_buff *skb = NULL;
 157
 158         zap_completion_queue();
 159 repeat:
 160         if (nr_skbs < MAX_SKBS)
 161                 refill_skbs();
 162
 163         skb = alloc_skb(len, GFP_ATOMIC);
 164
 165         if (!skb) {
 166                 spin_lock_irqsave(&skb_list_lock, flags);
 167                 skb = skbs;
 168                 if (skb)
 169                         skbs = skb->next;
 170                 skb->next = NULL;
 171                 nr_skbs--;
 172                 spin_unlock_irqrestore(&skb_list_lock, flags);
 173         }
 174
 175         if(!skb) {
 176                 count++;
 177                 if (once && (count == 1000000)) {
 178                         printk("out of netpoll skbs!\n");
 179                         once = 0;
 180                 }
 181                 netpoll_poll(np);
 182                 goto repeat;
 183         }
 184
 185         atomic_set(&skb->users, 1);
 186         skb_reserve(skb, reserve);
 187         return skb;
 188 }
 189
 190 static void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
 191 {
 192         int status;
 193
 194 repeat:
 195         if(!np || !np->dev || !netif_running(np->dev)) {
 196                 __kfree_skb(skb);
 197                 return;
 198         }
 199
 200         spin_lock(&np->dev->xmit_lock);
 201         np->dev->xmit_lock_owner = smp_processor_id();
 202
 203         /*
 204          * network drivers do not expect to be called if the queue is
 205          * stopped.
 206          */
 207         if (netif_queue_stopped(np->dev)) {
 208                 np->dev->xmit_lock_owner = -1;
 209                 spin_unlock(&np->dev->xmit_lock);
 210
 211                 netpoll_poll(np);
 212                 goto repeat;
 213         }
 214
 215         status = np->dev->hard_start_xmit(skb, np->dev);
 216         np->dev->xmit_lock_owner = -1;
 217         spin_unlock(&np->dev->xmit_lock);
 218
 219         /* transmit busy */
 220         if(status) {
 221                 netpoll_poll(np);
 222                 goto repeat;
 223         }
 224 }
 225
 226 void netpoll_send_udp(struct netpoll *np, const char *msg, int len)
 227 {
 228         int total_len, eth_len, ip_len, udp_len;
 229         struct sk_buff *skb;
 230         struct udphdr *udph;
 231         struct iphdr *iph;
 232         struct ethhdr *eth;
 233
 234         udp_len = len + sizeof(*udph);
 235         ip_len = eth_len = udp_len + sizeof(*iph);
 236         total_len = eth_len + ETH_HLEN;
 237
 238         skb = find_skb(np, total_len, total_len - len);
 239         if (!skb)
 240                 return;
 241
 242         memcpy(skb->data, msg, len);
 243         skb->len += len;
 244
 245         udph = (struct udphdr *) skb_push(skb, sizeof(*udph));
 246         udph->source = htons(np->local_port);
 247         udph->dest = htons(np->remote_port);
 248         udph->len = htons(udp_len);
 249         udph->check = 0;
 250
 251         iph = (struct iphdr *)skb_push(skb, sizeof(*iph));
 252
 253         /* iph->version = 4; iph->ihl = 5; */
 254         put_unaligned(0x45, (unsigned char *)iph);
 255         iph->tos      = 0;
 256         put_unaligned(htons(ip_len), &(iph->tot_len));
 257         iph->id       = 0;
 258         iph->frag_off = 0;
 259         iph->ttl      = 64;
 260         iph->protocol = IPPROTO_UDP;
 261         iph->check    = 0;
 262         put_unaligned(htonl(np->local_ip), &(iph->saddr));
 263         put_unaligned(htonl(np->remote_ip), &(iph->daddr));
 264         iph->check    = ip_fast_csum((unsigned char *)iph, iph->ihl);
 265
 266         eth = (struct ethhdr *) skb_push(skb, ETH_HLEN);
 267
 268         eth->h_proto = htons(ETH_P_IP);
 269         memcpy(eth->h_source, np->local_mac, 6);
 270         memcpy(eth->h_dest, np->remote_mac, 6);
 271
 272         netpoll_send_skb(np, skb);
 273 }
 274
 275 static void arp_reply(struct sk_buff *skb)
 276 {
 277         struct arphdr *arp;
 278         unsigned char *arp_ptr;
 279         int size, type = ARPOP_REPLY, ptype = ETH_P_ARP;
 280         u32 sip, tip;
 281         struct sk_buff *send_skb;
 282         unsigned long flags;
 283         struct list_head *p;
 284         struct netpoll *np = NULL;
 285
 286         spin_lock_irqsave(&rx_list_lock, flags);
 287         list_for_each(p, &rx_list) {
 288                 np = list_entry(p, struct netpoll, rx_list);
 289                 if ( np->dev == skb->dev )
 290                         break;
 291                 np = NULL;
 292         }
 293         spin_unlock_irqrestore(&rx_list_lock, flags);
 294
 295         if (!np) return;
 296
 297         /* No arp on this interface */
 298         if (skb->dev->flags & IFF_NOARP)
 299                 return;
 300
 301         if (!pskb_may_pull(skb, (sizeof(struct arphdr) +
 302                                  (2 * skb->dev->addr_len) +
 303                                  (2 * sizeof(u32)))))
 304                 return;
 305
 306         skb->h.raw = skb->nh.raw = skb->data;
 307         arp = skb->nh.arph;
 308
 309         if ((arp->ar_hrd != htons(ARPHRD_ETHER) &&
 310              arp->ar_hrd != htons(ARPHRD_IEEE802)) ||
 311             arp->ar_pro != htons(ETH_P_IP) ||
 312             arp->ar_op != htons(ARPOP_REQUEST))
 313                 return;
 314
 315         arp_ptr = (unsigned char *)(arp+1) + skb->dev->addr_len;
 316         memcpy(&sip, arp_ptr, 4);
 317         arp_ptr += 4 + skb->dev->addr_len;
 318         memcpy(&tip, arp_ptr, 4);
 319
 320         /* Should we ignore arp? */
 321         if (tip != htonl(np->local_ip) || LOOPBACK(tip) || MULTICAST(tip))
 322                 return;
 323
 324         size = sizeof(struct arphdr) + 2 * (skb->dev->addr_len + 4);
 325         send_skb = find_skb(np, size + LL_RESERVED_SPACE(np->dev),
 326                             LL_RESERVED_SPACE(np->dev));
 327
 328         if (!send_skb)
 329                 return;
 330
 331         send_skb->nh.raw = send_skb->data;
 332         arp = (struct arphdr *) skb_put(send_skb, size);
 333         send_skb->dev = skb->dev;
 334         send_skb->protocol = htons(ETH_P_ARP);
 335
 336         /* Fill the device header for the ARP frame */
 337
 338         if (np->dev->hard_header &&
 339             np->dev->hard_header(send_skb, skb->dev, ptype,
 340                                        np->remote_mac, np->local_mac,
 341                                        send_skb->len) < 0) {
 342                 kfree_skb(send_skb);
 343                 return;
 344         }
 345
 346         /*
 347          * Fill out the arp protocol part.
 348          *
 349          * we only support ethernet device type,
 350          * which (according to RFC 1390) should always equal 1 (Ethernet).
 351          */
 352
 353         arp->ar_hrd = htons(np->dev->type);
 354         arp->ar_pro = htons(ETH_P_IP);
 355         arp->ar_hln = np->dev->addr_len;
 356         arp->ar_pln = 4;
 357         arp->ar_op = htons(type);
 358
 359         arp_ptr=(unsigned char *)(arp + 1);
 360         memcpy(arp_ptr, np->dev->dev_addr, np->dev->addr_len);
 361         arp_ptr += np->dev->addr_len;
 362         memcpy(arp_ptr, &tip, 4);
 363         arp_ptr += 4;
 364         memcpy(arp_ptr, np->remote_mac, np->dev->addr_len);
 365         arp_ptr += np->dev->addr_len;
 366         memcpy(arp_ptr, &sip, 4);
 367
 368         netpoll_send_skb(np, send_skb);
 369 }
 370
 371 int netpoll_rx(struct sk_buff *skb)
 372 {
 373         int proto, len, ulen;
 374         struct iphdr *iph;
 375         struct udphdr *uh;
 376         struct netpoll *np;
 377         struct list_head *p;
 378         unsigned long flags;
 379
 380         if (skb->dev->type != ARPHRD_ETHER)
 381                 goto out;
 382
 383         /* check if netpoll clients need ARP */
 384         if (skb->protocol == __constant_htons(ETH_P_ARP) &&
 385             atomic_read(&trapped)) {
 386                 arp_reply(skb);
 387                 return 1;
 388         }
 389
 390         proto = ntohs(eth_hdr(skb)->h_proto);
 391         if (proto != ETH_P_IP)
 392                 goto out;
 393         if (skb->pkt_type == PACKET_OTHERHOST)
 394                 goto out;
 395         if (skb_shared(skb))
 396                 goto out;
 397
 398         iph = (struct iphdr *)skb->data;
 399         if (!pskb_may_pull(skb, sizeof(struct iphdr)))
 400                 goto out;
 401         if (iph->ihl < 5 || iph->version != 4)
 402                 goto out;
 403         if (!pskb_may_pull(skb, iph->ihl*4))
 404                 goto out;
 405         if (ip_fast_csum((u8 *)iph, iph->ihl) != 0)
 406                 goto out;
 407
 408         len = ntohs(iph->tot_len);
 409         if (skb->len < len || len < iph->ihl*4)
 410                 goto out;
 411
 412         if (iph->protocol != IPPROTO_UDP)
 413                 goto out;
 414
 415         len -= iph->ihl*4;
 416         uh = (struct udphdr *)(((char *)iph) + iph->ihl*4);
 417         ulen = ntohs(uh->len);
 418
 419         if (ulen != len)
 420                 goto out;
 421         if (checksum_udp(skb, uh, ulen, iph->saddr, iph->daddr) < 0)
 422                 goto out;
 423
 424         spin_lock_irqsave(&rx_list_lock, flags);
 425         list_for_each(p, &rx_list) {
 426                 np = list_entry(p, struct netpoll, rx_list);
 427                 if (np->dev && np->dev != skb->dev)
 428                         continue;
 429                 if (np->local_ip && np->local_ip != ntohl(iph->daddr))
 430                         continue;
 431                 if (np->remote_ip && np->remote_ip != ntohl(iph->saddr))
 432                         continue;
 433                 if (np->local_port && np->local_port != ntohs(uh->dest))
 434                         continue;
 435
 436                 spin_unlock_irqrestore(&rx_list_lock, flags);
 437
 438                 if (np->rx_hook)
 439                         np->rx_hook(np, ntohs(uh->source),
 440                                     (char *)(uh+1),
 441                                     ulen - sizeof(struct udphdr));
 442
 443                 return 1;
 444         }
 445         spin_unlock_irqrestore(&rx_list_lock, flags);
 446
 447 out:
 448         return atomic_read(&trapped);
 449 }
 450
 451 int netpoll_parse_options(struct netpoll *np, char *opt)
 452 {
 453         char *cur=opt, *delim;
 454
 455         if(*cur != '@') {
 456                 if ((delim = strchr(cur, '@')) == NULL)
 457                         goto parse_failed;
 458                 *delim=0;
 459                 np->local_port=simple_strtol(cur, NULL, 10);
 460                 cur=delim;
 461         }
 462         cur++;
 463         printk(KERN_INFO "%s: local port %d\n", np->name, np->local_port);
 464
 465         if(*cur != '/') {
 466                 if ((delim = strchr(cur, '/')) == NULL)
 467                         goto parse_failed;
 468                 *delim=0;
 469                 np->local_ip=ntohl(in_aton(cur));
 470                 cur=delim;
 471
 472                 printk(KERN_INFO "%s: local IP %d.%d.%d.%d\n",
 473                        np->name, HIPQUAD(np->local_ip));
 474         }
 475         cur++;
 476
 477         if ( *cur != ',') {
 478                 /* parse out dev name */
 479                 if ((delim = strchr(cur, ',')) == NULL)
 480                         goto parse_failed;
 481                 *delim=0;
 482                 strlcpy(np->dev_name, cur, sizeof(np->dev_name));
 483                 cur=delim;
 484         }
 485         cur++;
 486
 487         printk(KERN_INFO "%s: interface %s\n", np->name, np->dev_name);
 488
 489         if ( *cur != '@' ) {
 490                 /* dst port */
 491                 if ((delim = strchr(cur, '@')) == NULL)
 492                         goto parse_failed;
 493                 *delim=0;
 494                 np->remote_port=simple_strtol(cur, NULL, 10);
 495                 cur=delim;
 496         }
 497         cur++;
 498         printk(KERN_INFO "%s: remote port %d\n", np->name, np->remote_port);
 499
 500         /* dst ip */
 501         if ((delim = strchr(cur, '/')) == NULL)
 502                 goto parse_failed;
 503         *delim=0;
 504         np->remote_ip=ntohl(in_aton(cur));
 505         cur=delim+1;
 506
 507         printk(KERN_INFO "%s: remote IP %d.%d.%d.%d\n",
 508                        np->name, HIPQUAD(np->remote_ip));
 509
 510         if( *cur != 0 )
 511         {
 512                 /* MAC address */
 513                 if ((delim = strchr(cur, ':')) == NULL)
 514                         goto parse_failed;
 515                 *delim=0;
 516                 np->remote_mac[0]=simple_strtol(cur, NULL, 16);
 517                 cur=delim+1;
 518                 if ((delim = strchr(cur, ':')) == NULL)
 519                         goto parse_failed;
 520                 *delim=0;
 521                 np->remote_mac[1]=simple_strtol(cur, NULL, 16);
 522                 cur=delim+1;
 523                 if ((delim = strchr(cur, ':')) == NULL)
 524                         goto parse_failed;
 525                 *delim=0;
 526                 np->remote_mac[2]=simple_strtol(cur, NULL, 16);
 527                 cur=delim+1;
 528                 if ((delim = strchr(cur, ':')) == NULL)
 529                         goto parse_failed;
 530                 *delim=0;
 531                 np->remote_mac[3]=simple_strtol(cur, NULL, 16);
 532                 cur=delim+1;
 533                 if ((delim = strchr(cur, ':')) == NULL)
 534                         goto parse_failed;
 535                 *delim=0;
 536                 np->remote_mac[4]=simple_strtol(cur, NULL, 16);
 537                 cur=delim+1;
 538                 np->remote_mac[5]=simple_strtol(cur, NULL, 16);
 539         }
 540
 541         printk(KERN_INFO "%s: remote ethernet address "
 542                "%02x:%02x:%02x:%02x:%02x:%02x\n",
 543                np->name,
 544                np->remote_mac[0],
 545                np->remote_mac[1],
 546                np->remote_mac[2],
 547                np->remote_mac[3],
 548                np->remote_mac[4],
 549                np->remote_mac[5]);
 550
 551         return 0;
 552
 553  parse_failed:
 554         printk(KERN_INFO "%s: couldn't parse config at %s!\n",
 555                np->name, cur);
 556         return -1;
 557 }
 558
 559 int netpoll_setup(struct netpoll *np)
 560 {
 561         struct net_device *ndev = NULL;
 562         struct in_device *in_dev;
 563
 564         if (np->dev_name)
 565                 ndev = dev_get_by_name(np->dev_name);
 566         if (!ndev) {
 567                 printk(KERN_ERR "%s: %s doesn't exist, aborting.\n",
 568                        np->name, np->dev_name);
 569                 return -1;
 570         }
 571         if (!ndev->poll_controller) {
 572                 printk(KERN_ERR "%s: %s doesn't support polling, aborting.\n",
 573                        np->name, np->dev_name);
 574                 goto release;
 575         }
 576
 577         if (!netif_running(ndev)) {
 578                 unsigned short oflags;
 579                 unsigned long atmost, atleast;
 580
 581                 printk(KERN_INFO "%s: device %s not up yet, forcing it\n",
 582                        np->name, np->dev_name);
 583
 584                 oflags = ndev->flags;
 585
 586                 rtnl_shlock();
 587                 if (dev_change_flags(ndev, oflags | IFF_UP) < 0) {
 588                         printk(KERN_ERR "%s: failed to open %s\n",
 589                                np->name, np->dev_name);
 590                         rtnl_shunlock();
 591                         goto release;
 592                 }
 593                 rtnl_shunlock();
 594
 595                 atleast = jiffies + HZ/10;
 596                 atmost = jiffies + 10*HZ;
 597                 while (!netif_carrier_ok(ndev)) {
 598                         if (time_after(jiffies, atmost)) {
 599                                 printk(KERN_NOTICE
 600                                        "%s: timeout waiting for carrier\n",
 601                                        np->name);
 602                                 break;
 603                         }
 604                         cond_resched();
 605                 }
 606
 607                 if (time_before(jiffies, atleast)) {
 608                         printk(KERN_NOTICE "%s: carrier detect appears flaky,"
 609                                " waiting 10 seconds\n",
 610                                np->name);
 611                         while (time_before(jiffies, atmost))
 612                                 cond_resched();
 613                 }
 614         }
 615
 616         if (!memcmp(np->local_mac, "\0\0\0\0\0\0", 6) && ndev->dev_addr)
 617                 memcpy(np->local_mac, ndev->dev_addr, 6);
 618
 619         if (!np->local_ip) {
 620                 rcu_read_lock();
 621                 in_dev = __in_dev_get(ndev);
 622
 623                 if (!in_dev || !in_dev->ifa_list) {
 624                         rcu_read_unlock();
 625                         printk(KERN_ERR "%s: no IP address for %s, aborting\n",
 626                                np->name, np->dev_name);
 627                         goto release;
 628                 }
 629
 630                 np->local_ip = ntohl(in_dev->ifa_list->ifa_local);
 631                 rcu_read_unlock();
 632                 printk(KERN_INFO "%s: local IP %d.%d.%d.%d\n",
 633                        np->name, HIPQUAD(np->local_ip));
 634         }
 635
 636         np->dev = ndev;
 637
 638         if(np->rx_hook) {
 639                 unsigned long flags;
 640
 641                 np->dev->netpoll_rx = NETPOLL_RX_ENABLED;
 642
 643                 spin_lock_irqsave(&rx_list_lock, flags);
 644                 list_add(&np->rx_list, &rx_list);
 645                 spin_unlock_irqrestore(&rx_list_lock, flags);
 646         }
 647
 648         return 0;
 649  release:
 650         dev_put(ndev);
 651         return -1;
 652 }
 653
 654 void netpoll_cleanup(struct netpoll *np)
 655 {
 656         if (np->rx_hook) {
 657                 unsigned long flags;
 658
 659                 spin_lock_irqsave(&rx_list_lock, flags);
 660                 list_del(&np->rx_list);
 661                 spin_unlock_irqrestore(&rx_list_lock, flags);
 662         }
 663
 664         if (np->dev)
 665                 np->dev->netpoll_rx = 0;
 666         dev_put(np->dev);
 667         np->dev = NULL;
 668 }
 669
 670 int netpoll_trap(void)
 671 {
 672         return atomic_read(&trapped);
 673 }
 674
 675 void netpoll_set_trap(int trap)
 676 {
 677         if (trap)
 678                 atomic_inc(&trapped);
 679         else
 680                 atomic_dec(&trapped);
 681 }
 682
 683 EXPORT_SYMBOL(netpoll_set_trap);
 684 EXPORT_SYMBOL(netpoll_trap);
 685 EXPORT_SYMBOL(netpoll_parse_options);
 686 EXPORT_SYMBOL(netpoll_setup);
 687 EXPORT_SYMBOL(netpoll_cleanup);
 688 EXPORT_SYMBOL(netpoll_send_udp);
 689 EXPORT_SYMBOL(netpoll_poll);