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/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 DEFINE_SPINLOCK(skb_list_lock); 38 static int nr_skbs; 39 static struct sk_buff *skbs; 40 41 static DEFINE_SPINLOCK(queue_lock); 42 static int queue_depth; 43 static struct sk_buff *queue_head, *queue_tail; 44 45 static atomic_t trapped; 46 47 #define NETPOLL_RX_ENABLED 1 48 #define NETPOLL_RX_DROP 2 49 50 #define MAX_SKB_SIZE \ 51 (MAX_UDP_CHUNK + sizeof(struct udphdr) + \ 52 sizeof(struct iphdr) + sizeof(struct ethhdr)) 53 54 static void zap_completion_queue(void); 55 56 static void queue_process(void *p) 57 { 58 unsigned long flags; 59 struct sk_buff *skb; 60 61 while (queue_head) { 62 spin_lock_irqsave(&queue_lock, flags); 63 64 skb = queue_head; 65 queue_head = skb->next; 66 if (skb == queue_tail) 67 queue_head = NULL; 68 69 queue_depth--; 70 71 spin_unlock_irqrestore(&queue_lock, flags); 72 73 dev_queue_xmit(skb); 74 } 75 } 76 77 static DECLARE_WORK(send_queue, queue_process, NULL); 78 79 void netpoll_queue(struct sk_buff *skb) 80 { 81 unsigned long flags; 82 83 if (queue_depth == MAX_QUEUE_DEPTH) { 84 __kfree_skb(skb); 85 return; 86 } 87 88 spin_lock_irqsave(&queue_lock, flags); 89 if (!queue_head) 90 queue_head = skb; 91 else 92 queue_tail->next = skb; 93 queue_tail = skb; 94 queue_depth++; 95 spin_unlock_irqrestore(&queue_lock, flags); 96 97 schedule_work(&send_queue); 98 } 99 100 static int checksum_udp(struct sk_buff *skb, struct udphdr *uh, 101 unsigned short ulen, u32 saddr, u32 daddr) 102 { 103 if (uh->check == 0) 104 return 0; 105 106 if (skb->ip_summed == CHECKSUM_HW) 107 return csum_tcpudp_magic( 108 saddr, daddr, ulen, IPPROTO_UDP, skb->csum); 109 110 skb->csum = csum_tcpudp_nofold(saddr, daddr, ulen, IPPROTO_UDP, 0); 111 112 return csum_fold(skb_checksum(skb, 0, skb->len, skb->csum)); 113 } 114 115 /* 116 * Check whether delayed processing was scheduled for our NIC. If so, 117 * we attempt to grab the poll lock and use ->poll() to pump the card. 118 * If this fails, either we've recursed in ->poll() or it's already 119 * running on another CPU. 120 * 121 * Note: we don't mask interrupts with this lock because we're using 122 * trylock here and interrupts are already disabled in the softirq 123 * case. Further, we test the poll_owner to avoid recursion on UP 124 * systems where the lock doesn't exist. 125 * 126 * In cases where there is bi-directional communications, reading only 127 * one message at a time can lead to packets being dropped by the 128 * network adapter, forcing superfluous retries and possibly timeouts. 129 * Thus, we set our budget to greater than 1. 130 */ 131 static void poll_napi(struct netpoll *np) 132 { 133 struct netpoll_info *npinfo = np->dev->npinfo; 134 int budget = 16; 135 136 if (test_bit(__LINK_STATE_RX_SCHED, &np->dev->state) && 137 npinfo->poll_owner != smp_processor_id() && 138 spin_trylock(&npinfo->poll_lock)) { 139 npinfo->rx_flags |= NETPOLL_RX_DROP; 140 atomic_inc(&trapped); 141 142 np->dev->poll(np->dev, &budget); 143 144 atomic_dec(&trapped); 145 npinfo->rx_flags &= ~NETPOLL_RX_DROP; 146 spin_unlock(&npinfo->poll_lock); 147 } 148 } 149 150 void netpoll_poll(struct netpoll *np) 151 { 152 if(!np->dev || !netif_running(np->dev) || !np->dev->poll_controller) 153 return; 154 155 /* Process pending work on NIC */ 156 np->dev->poll_controller(np->dev); 157 if (np->dev->poll) 158 poll_napi(np); 159 160 zap_completion_queue(); 161 } 162 163 static void refill_skbs(void) 164 { 165 struct sk_buff *skb; 166 unsigned long flags; 167 168 spin_lock_irqsave(&skb_list_lock, flags); 169 while (nr_skbs < MAX_SKBS) { 170 skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC); 171 if (!skb) 172 break; 173 174 skb->next = skbs; 175 skbs = skb; 176 nr_skbs++; 177 } 178 spin_unlock_irqrestore(&skb_list_lock, flags); 179 } 180 181 static void zap_completion_queue(void) 182 { 183 unsigned long flags; 184 struct softnet_data *sd = &get_cpu_var(softnet_data); 185 186 if (sd->completion_queue) { 187 struct sk_buff *clist; 188 189 local_irq_save(flags); 190 clist = sd->completion_queue; 191 sd->completion_queue = NULL; 192 local_irq_restore(flags); 193 194 while (clist != NULL) { 195 struct sk_buff *skb = clist; 196 clist = clist->next; 197 if(skb->destructor) 198 dev_kfree_skb_any(skb); /* put this one back */ 199 else 200 __kfree_skb(skb); 201 } 202 } 203 204 put_cpu_var(softnet_data); 205 } 206 207 static struct sk_buff * find_skb(struct netpoll *np, int len, int reserve) 208 { 209 int once = 1, count = 0; 210 unsigned long flags; 211 struct sk_buff *skb = NULL; 212 213 zap_completion_queue(); 214 repeat: 215 if (nr_skbs < MAX_SKBS) 216 refill_skbs(); 217 218 skb = alloc_skb(len, GFP_ATOMIC); 219 220 if (!skb) { 221 spin_lock_irqsave(&skb_list_lock, flags); 222 skb = skbs; 223 if (skb) { 224 skbs = skb->next; 225 skb->next = NULL; 226 nr_skbs--; 227 } 228 spin_unlock_irqrestore(&skb_list_lock, flags); 229 } 230 231 if(!skb) { 232 count++; 233 if (once && (count == 1000000)) { 234 printk("out of netpoll skbs!\n"); 235 once = 0; 236 } 237 netpoll_poll(np); 238 goto repeat; 239 } 240 241 atomic_set(&skb->users, 1); 242 skb_reserve(skb, reserve); 243 return skb; 244 } 245 246 static void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb) 247 { 248 int status; 249 struct netpoll_info *npinfo; 250 251 repeat: 252 if(!np || !np->dev || !netif_running(np->dev)) { 253 __kfree_skb(skb); 254 return; 255 } 256 257 /* avoid recursion */ 258 npinfo = np->dev->npinfo; 259 if (npinfo->poll_owner == smp_processor_id() || 260 np->dev->xmit_lock_owner == smp_processor_id()) { 261 if (np->drop) 262 np->drop(skb); 263 else 264 __kfree_skb(skb); 265 return; 266 } 267 268 spin_lock(&np->dev->xmit_lock); 269 np->dev->xmit_lock_owner = smp_processor_id(); 270 271 /* 272 * network drivers do not expect to be called if the queue is 273 * stopped. 274 */ 275 if (netif_queue_stopped(np->dev)) { 276 np->dev->xmit_lock_owner = -1; 277 spin_unlock(&np->dev->xmit_lock); 278 279 netpoll_poll(np); 280 goto repeat; 281 } 282 283 status = np->dev->hard_start_xmit(skb, np->dev); 284 np->dev->xmit_lock_owner = -1; 285 spin_unlock(&np->dev->xmit_lock); 286 287 /* transmit busy */ 288 if(status) { 289 netpoll_poll(np); 290 goto repeat; 291 } 292 } 293 294 void netpoll_send_udp(struct netpoll *np, const char *msg, int len) 295 { 296 int total_len, eth_len, ip_len, udp_len; 297 struct sk_buff *skb; 298 struct udphdr *udph; 299 struct iphdr *iph; 300 struct ethhdr *eth; 301 302 udp_len = len + sizeof(*udph); 303 ip_len = eth_len = udp_len + sizeof(*iph); 304 total_len = eth_len + ETH_HLEN + NET_IP_ALIGN; 305 306 skb = find_skb(np, total_len, total_len - len); 307 if (!skb) 308 return; 309 310 memcpy(skb->data, msg, len); 311 skb->len += len; 312 313 udph = (struct udphdr *) skb_push(skb, sizeof(*udph)); 314 udph->source = htons(np->local_port); 315 udph->dest = htons(np->remote_port); 316 udph->len = htons(udp_len); 317 udph->check = 0; 318 319 iph = (struct iphdr *)skb_push(skb, sizeof(*iph)); 320 321 /* iph->version = 4; iph->ihl = 5; */ 322 put_unaligned(0x45, (unsigned char *)iph); 323 iph->tos = 0; 324 put_unaligned(htons(ip_len), &(iph->tot_len)); 325 iph->id = 0; 326 iph->frag_off = 0; 327 iph->ttl = 64; 328 iph->protocol = IPPROTO_UDP; 329 iph->check = 0; 330 put_unaligned(htonl(np->local_ip), &(iph->saddr)); 331 put_unaligned(htonl(np->remote_ip), &(iph->daddr)); 332 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); 333 334 eth = (struct ethhdr *) skb_push(skb, ETH_HLEN); 335 336 eth->h_proto = htons(ETH_P_IP); 337 memcpy(eth->h_source, np->local_mac, 6); 338 memcpy(eth->h_dest, np->remote_mac, 6); 339 340 skb->dev = np->dev; 341 342 netpoll_send_skb(np, skb); 343 } 344 345 static void arp_reply(struct sk_buff *skb) 346 { 347 struct netpoll_info *npinfo = skb->dev->npinfo; 348 struct arphdr *arp; 349 unsigned char *arp_ptr; 350 int size, type = ARPOP_REPLY, ptype = ETH_P_ARP; 351 u32 sip, tip; 352 unsigned long flags; 353 struct sk_buff *send_skb; 354 struct netpoll *np = NULL; 355 356 spin_lock_irqsave(&npinfo->rx_lock, flags); 357 if (npinfo->rx_np && npinfo->rx_np->dev == skb->dev) 358 np = npinfo->rx_np; 359 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 360 361 if (!np) 362 return; 363 364 /* No arp on this interface */ 365 if (skb->dev->flags & IFF_NOARP) 366 return; 367 368 if (!pskb_may_pull(skb, (sizeof(struct arphdr) + 369 (2 * skb->dev->addr_len) + 370 (2 * sizeof(u32))))) 371 return; 372 373 skb->h.raw = skb->nh.raw = skb->data; 374 arp = skb->nh.arph; 375 376 if ((arp->ar_hrd != htons(ARPHRD_ETHER) && 377 arp->ar_hrd != htons(ARPHRD_IEEE802)) || 378 arp->ar_pro != htons(ETH_P_IP) || 379 arp->ar_op != htons(ARPOP_REQUEST)) 380 return; 381 382 arp_ptr = (unsigned char *)(arp+1) + skb->dev->addr_len; 383 memcpy(&sip, arp_ptr, 4); 384 arp_ptr += 4 + skb->dev->addr_len; 385 memcpy(&tip, arp_ptr, 4); 386 387 /* Should we ignore arp? */ 388 if (tip != htonl(np->local_ip) || LOOPBACK(tip) || MULTICAST(tip)) 389 return; 390 391 size = sizeof(struct arphdr) + 2 * (skb->dev->addr_len + 4); 392 send_skb = find_skb(np, size + LL_RESERVED_SPACE(np->dev), 393 LL_RESERVED_SPACE(np->dev)); 394 395 if (!send_skb) 396 return; 397 398 send_skb->nh.raw = send_skb->data; 399 arp = (struct arphdr *) skb_put(send_skb, size); 400 send_skb->dev = skb->dev; 401 send_skb->protocol = htons(ETH_P_ARP); 402 403 /* Fill the device header for the ARP frame */ 404 405 if (np->dev->hard_header && 406 np->dev->hard_header(send_skb, skb->dev, ptype, 407 np->remote_mac, np->local_mac, 408 send_skb->len) < 0) { 409 kfree_skb(send_skb); 410 return; 411 } 412 413 /* 414 * Fill out the arp protocol part. 415 * 416 * we only support ethernet device type, 417 * which (according to RFC 1390) should always equal 1 (Ethernet). 418 */ 419 420 arp->ar_hrd = htons(np->dev->type); 421 arp->ar_pro = htons(ETH_P_IP); 422 arp->ar_hln = np->dev->addr_len; 423 arp->ar_pln = 4; 424 arp->ar_op = htons(type); 425 426 arp_ptr=(unsigned char *)(arp + 1); 427 memcpy(arp_ptr, np->dev->dev_addr, np->dev->addr_len); 428 arp_ptr += np->dev->addr_len; 429 memcpy(arp_ptr, &tip, 4); 430 arp_ptr += 4; 431 memcpy(arp_ptr, np->remote_mac, np->dev->addr_len); 432 arp_ptr += np->dev->addr_len; 433 memcpy(arp_ptr, &sip, 4); 434 435 netpoll_send_skb(np, send_skb); 436 } 437 438 int __netpoll_rx(struct sk_buff *skb) 439 { 440 int proto, len, ulen; 441 struct iphdr *iph; 442 struct udphdr *uh; 443 struct netpoll *np = skb->dev->npinfo->rx_np; 444 445 if (!np) 446 goto out; 447 if (skb->dev->type != ARPHRD_ETHER) 448 goto out; 449 450 /* check if netpoll clients need ARP */ 451 if (skb->protocol == __constant_htons(ETH_P_ARP) && 452 atomic_read(&trapped)) { 453 arp_reply(skb); 454 return 1; 455 } 456 457 proto = ntohs(eth_hdr(skb)->h_proto); 458 if (proto != ETH_P_IP) 459 goto out; 460 if (skb->pkt_type == PACKET_OTHERHOST) 461 goto out; 462 if (skb_shared(skb)) 463 goto out; 464 465 iph = (struct iphdr *)skb->data; 466 if (!pskb_may_pull(skb, sizeof(struct iphdr))) 467 goto out; 468 if (iph->ihl < 5 || iph->version != 4) 469 goto out; 470 if (!pskb_may_pull(skb, iph->ihl*4)) 471 goto out; 472 if (ip_fast_csum((u8 *)iph, iph->ihl) != 0) 473 goto out; 474 475 len = ntohs(iph->tot_len); 476 if (skb->len < len || len < iph->ihl*4) 477 goto out; 478 479 if (iph->protocol != IPPROTO_UDP) 480 goto out; 481 482 len -= iph->ihl*4; 483 uh = (struct udphdr *)(((char *)iph) + iph->ihl*4); 484 ulen = ntohs(uh->len); 485 486 if (ulen != len) 487 goto out; 488 if (checksum_udp(skb, uh, ulen, iph->saddr, iph->daddr) < 0) 489 goto out; 490 if (np->local_ip && np->local_ip != ntohl(iph->daddr)) 491 goto out; 492 if (np->remote_ip && np->remote_ip != ntohl(iph->saddr)) 493 goto out; 494 if (np->local_port && np->local_port != ntohs(uh->dest)) 495 goto out; 496 497 np->rx_hook(np, ntohs(uh->source), 498 (char *)(uh+1), 499 ulen - sizeof(struct udphdr)); 500 501 kfree_skb(skb); 502 return 1; 503 504 out: 505 if (atomic_read(&trapped)) { 506 kfree_skb(skb); 507 return 1; 508 } 509 510 return 0; 511 } 512 513 int netpoll_parse_options(struct netpoll *np, char *opt) 514 { 515 char *cur=opt, *delim; 516 517 if(*cur != '@') { 518 if ((delim = strchr(cur, '@')) == NULL) 519 goto parse_failed; 520 *delim=0; 521 np->local_port=simple_strtol(cur, NULL, 10); 522 cur=delim; 523 } 524 cur++; 525 printk(KERN_INFO "%s: local port %d\n", np->name, np->local_port); 526 527 if(*cur != '/') { 528 if ((delim = strchr(cur, '/')) == NULL) 529 goto parse_failed; 530 *delim=0; 531 np->local_ip=ntohl(in_aton(cur)); 532 cur=delim; 533 534 printk(KERN_INFO "%s: local IP %d.%d.%d.%d\n", 535 np->name, HIPQUAD(np->local_ip)); 536 } 537 cur++; 538 539 if ( *cur != ',') { 540 /* parse out dev name */ 541 if ((delim = strchr(cur, ',')) == NULL) 542 goto parse_failed; 543 *delim=0; 544 strlcpy(np->dev_name, cur, sizeof(np->dev_name)); 545 cur=delim; 546 } 547 cur++; 548 549 printk(KERN_INFO "%s: interface %s\n", np->name, np->dev_name); 550 551 if ( *cur != '@' ) { 552 /* dst port */ 553 if ((delim = strchr(cur, '@')) == NULL) 554 goto parse_failed; 555 *delim=0; 556 np->remote_port=simple_strtol(cur, NULL, 10); 557 cur=delim; 558 } 559 cur++; 560 printk(KERN_INFO "%s: remote port %d\n", np->name, np->remote_port); 561 562 /* dst ip */ 563 if ((delim = strchr(cur, '/')) == NULL) 564 goto parse_failed; 565 *delim=0; 566 np->remote_ip=ntohl(in_aton(cur)); 567 cur=delim+1; 568 569 printk(KERN_INFO "%s: remote IP %d.%d.%d.%d\n", 570 np->name, HIPQUAD(np->remote_ip)); 571 572 if( *cur != 0 ) 573 { 574 /* MAC address */ 575 if ((delim = strchr(cur, ':')) == NULL) 576 goto parse_failed; 577 *delim=0; 578 np->remote_mac[0]=simple_strtol(cur, NULL, 16); 579 cur=delim+1; 580 if ((delim = strchr(cur, ':')) == NULL) 581 goto parse_failed; 582 *delim=0; 583 np->remote_mac[1]=simple_strtol(cur, NULL, 16); 584 cur=delim+1; 585 if ((delim = strchr(cur, ':')) == NULL) 586 goto parse_failed; 587 *delim=0; 588 np->remote_mac[2]=simple_strtol(cur, NULL, 16); 589 cur=delim+1; 590 if ((delim = strchr(cur, ':')) == NULL) 591 goto parse_failed; 592 *delim=0; 593 np->remote_mac[3]=simple_strtol(cur, NULL, 16); 594 cur=delim+1; 595 if ((delim = strchr(cur, ':')) == NULL) 596 goto parse_failed; 597 *delim=0; 598 np->remote_mac[4]=simple_strtol(cur, NULL, 16); 599 cur=delim+1; 600 np->remote_mac[5]=simple_strtol(cur, NULL, 16); 601 } 602 603 printk(KERN_INFO "%s: remote ethernet address " 604 "%02x:%02x:%02x:%02x:%02x:%02x\n", 605 np->name, 606 np->remote_mac[0], 607 np->remote_mac[1], 608 np->remote_mac[2], 609 np->remote_mac[3], 610 np->remote_mac[4], 611 np->remote_mac[5]); 612 613 return 0; 614 615 parse_failed: 616 printk(KERN_INFO "%s: couldn't parse config at %s!\n", 617 np->name, cur); 618 return -1; 619 } 620 621 int netpoll_setup(struct netpoll *np) 622 { 623 struct net_device *ndev = NULL; 624 struct in_device *in_dev; 625 struct netpoll_info *npinfo; 626 unsigned long flags; 627 628 if (np->dev_name) 629 ndev = dev_get_by_name(np->dev_name); 630 if (!ndev) { 631 printk(KERN_ERR "%s: %s doesn't exist, aborting.\n", 632 np->name, np->dev_name); 633 return -1; 634 } 635 636 np->dev = ndev; 637 if (!ndev->npinfo) { 638 npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL); 639 if (!npinfo) 640 goto release; 641 642 npinfo->rx_np = NULL; 643 npinfo->poll_lock = SPIN_LOCK_UNLOCKED; 644 npinfo->poll_owner = -1; 645 npinfo->rx_lock = SPIN_LOCK_UNLOCKED; 646 } else 647 npinfo = ndev->npinfo; 648 649 if (!ndev->poll_controller) { 650 printk(KERN_ERR "%s: %s doesn't support polling, aborting.\n", 651 np->name, np->dev_name); 652 goto release; 653 } 654 655 if (!netif_running(ndev)) { 656 unsigned long atmost, atleast; 657 658 printk(KERN_INFO "%s: device %s not up yet, forcing it\n", 659 np->name, np->dev_name); 660 661 rtnl_shlock(); 662 if (dev_change_flags(ndev, ndev->flags | IFF_UP) < 0) { 663 printk(KERN_ERR "%s: failed to open %s\n", 664 np->name, np->dev_name); 665 rtnl_shunlock(); 666 goto release; 667 } 668 rtnl_shunlock(); 669 670 atleast = jiffies + HZ/10; 671 atmost = jiffies + 4*HZ; 672 while (!netif_carrier_ok(ndev)) { 673 if (time_after(jiffies, atmost)) { 674 printk(KERN_NOTICE 675 "%s: timeout waiting for carrier\n", 676 np->name); 677 break; 678 } 679 cond_resched(); 680 } 681 682 /* If carrier appears to come up instantly, we don't 683 * trust it and pause so that we don't pump all our 684 * queued console messages into the bitbucket. 685 */ 686 687 if (time_before(jiffies, atleast)) { 688 printk(KERN_NOTICE "%s: carrier detect appears" 689 " untrustworthy, waiting 4 seconds\n", 690 np->name); 691 msleep(4000); 692 } 693 } 694 695 if (!memcmp(np->local_mac, "\0\0\0\0\0\0", 6) && ndev->dev_addr) 696 memcpy(np->local_mac, ndev->dev_addr, 6); 697 698 if (!np->local_ip) { 699 rcu_read_lock(); 700 in_dev = __in_dev_get(ndev); 701 702 if (!in_dev || !in_dev->ifa_list) { 703 rcu_read_unlock(); 704 printk(KERN_ERR "%s: no IP address for %s, aborting\n", 705 np->name, np->dev_name); 706 goto release; 707 } 708 709 np->local_ip = ntohl(in_dev->ifa_list->ifa_local); 710 rcu_read_unlock(); 711 printk(KERN_INFO "%s: local IP %d.%d.%d.%d\n", 712 np->name, HIPQUAD(np->local_ip)); 713 } 714 715 if (np->rx_hook) { 716 spin_lock_irqsave(&npinfo->rx_lock, flags); 717 npinfo->rx_flags |= NETPOLL_RX_ENABLED; 718 npinfo->rx_np = np; 719 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 720 } 721 /* last thing to do is link it to the net device structure */ 722 ndev->npinfo = npinfo; 723 724 return 0; 725 726 release: 727 if (!ndev->npinfo) 728 kfree(npinfo); 729 np->dev = NULL; 730 dev_put(ndev); 731 return -1; 732 } 733 734 void netpoll_cleanup(struct netpoll *np) 735 { 736 struct netpoll_info *npinfo; 737 unsigned long flags; 738 739 if (np->dev) { 740 npinfo = np->dev->npinfo; 741 if (npinfo && npinfo->rx_np == np) { 742 spin_lock_irqsave(&npinfo->rx_lock, flags); 743 npinfo->rx_np = NULL; 744 npinfo->rx_flags &= ~NETPOLL_RX_ENABLED; 745 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 746 } 747 dev_put(np->dev); 748 } 749 750 np->dev = NULL; 751 } 752 753 int netpoll_trap(void) 754 { 755 return atomic_read(&trapped); 756 } 757 758 void netpoll_set_trap(int trap) 759 { 760 if (trap) 761 atomic_inc(&trapped); 762 else 763 atomic_dec(&trapped); 764 } 765 766 EXPORT_SYMBOL(netpoll_set_trap); 767 EXPORT_SYMBOL(netpoll_trap); 768 EXPORT_SYMBOL(netpoll_parse_options); 769 EXPORT_SYMBOL(netpoll_setup); 770 EXPORT_SYMBOL(netpoll_cleanup); 771 EXPORT_SYMBOL(netpoll_send_udp); 772 EXPORT_SYMBOL(netpoll_poll); 773 EXPORT_SYMBOL(netpoll_queue); 774