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/if_arp.h> 17 #include <linux/inetdevice.h> 18 #include <linux/inet.h> 19 #include <linux/interrupt.h> 20 #include <linux/netpoll.h> 21 #include <linux/sched.h> 22 #include <linux/delay.h> 23 #include <linux/rcupdate.h> 24 #include <linux/workqueue.h> 25 #include <net/tcp.h> 26 #include <net/udp.h> 27 #include <asm/unaligned.h> 28 29 /* 30 * We maintain a small pool of fully-sized skbs, to make sure the 31 * message gets out even in extreme OOM situations. 32 */ 33 34 #define MAX_UDP_CHUNK 1460 35 #define MAX_SKBS 32 36 #define MAX_QUEUE_DEPTH (MAX_SKBS / 2) 37 #define MAX_RETRIES 20000 38 39 static DEFINE_SPINLOCK(skb_list_lock); 40 static int nr_skbs; 41 static struct sk_buff *skbs; 42 43 static DEFINE_SPINLOCK(queue_lock); 44 static int queue_depth; 45 static struct sk_buff *queue_head, *queue_tail; 46 47 static atomic_t trapped; 48 49 #define NETPOLL_RX_ENABLED 1 50 #define NETPOLL_RX_DROP 2 51 52 #define MAX_SKB_SIZE \ 53 (MAX_UDP_CHUNK + sizeof(struct udphdr) + \ 54 sizeof(struct iphdr) + sizeof(struct ethhdr)) 55 56 static void zap_completion_queue(void); 57 58 static void queue_process(void *p) 59 { 60 unsigned long flags; 61 struct sk_buff *skb; 62 63 while (queue_head) { 64 spin_lock_irqsave(&queue_lock, flags); 65 66 skb = queue_head; 67 queue_head = skb->next; 68 if (skb == queue_tail) 69 queue_head = NULL; 70 71 queue_depth--; 72 73 spin_unlock_irqrestore(&queue_lock, flags); 74 75 dev_queue_xmit(skb); 76 } 77 } 78 79 static DECLARE_WORK(send_queue, queue_process, NULL); 80 81 void netpoll_queue(struct sk_buff *skb) 82 { 83 unsigned long flags; 84 85 if (queue_depth == MAX_QUEUE_DEPTH) { 86 __kfree_skb(skb); 87 return; 88 } 89 90 spin_lock_irqsave(&queue_lock, flags); 91 if (!queue_head) 92 queue_head = skb; 93 else 94 queue_tail->next = skb; 95 queue_tail = skb; 96 queue_depth++; 97 spin_unlock_irqrestore(&queue_lock, flags); 98 99 schedule_work(&send_queue); 100 } 101 102 static int checksum_udp(struct sk_buff *skb, struct udphdr *uh, 103 unsigned short ulen, u32 saddr, u32 daddr) 104 { 105 unsigned int psum; 106 107 if (uh->check == 0 || skb->ip_summed == CHECKSUM_UNNECESSARY) 108 return 0; 109 110 psum = csum_tcpudp_nofold(saddr, daddr, ulen, IPPROTO_UDP, 0); 111 112 if (skb->ip_summed == CHECKSUM_HW && 113 !(u16)csum_fold(csum_add(psum, skb->csum))) 114 return 0; 115 116 skb->csum = psum; 117 118 return __skb_checksum_complete(skb); 119 } 120 121 /* 122 * Check whether delayed processing was scheduled for our NIC. If so, 123 * we attempt to grab the poll lock and use ->poll() to pump the card. 124 * If this fails, either we've recursed in ->poll() or it's already 125 * running on another CPU. 126 * 127 * Note: we don't mask interrupts with this lock because we're using 128 * trylock here and interrupts are already disabled in the softirq 129 * case. Further, we test the poll_owner to avoid recursion on UP 130 * systems where the lock doesn't exist. 131 * 132 * In cases where there is bi-directional communications, reading only 133 * one message at a time can lead to packets being dropped by the 134 * network adapter, forcing superfluous retries and possibly timeouts. 135 * Thus, we set our budget to greater than 1. 136 */ 137 static void poll_napi(struct netpoll *np) 138 { 139 struct netpoll_info *npinfo = np->dev->npinfo; 140 int budget = 16; 141 142 if (test_bit(__LINK_STATE_RX_SCHED, &np->dev->state) && 143 npinfo->poll_owner != smp_processor_id() && 144 spin_trylock(&npinfo->poll_lock)) { 145 npinfo->rx_flags |= NETPOLL_RX_DROP; 146 atomic_inc(&trapped); 147 148 np->dev->poll(np->dev, &budget); 149 150 atomic_dec(&trapped); 151 npinfo->rx_flags &= ~NETPOLL_RX_DROP; 152 spin_unlock(&npinfo->poll_lock); 153 } 154 } 155 156 void netpoll_poll(struct netpoll *np) 157 { 158 if(!np->dev || !netif_running(np->dev) || !np->dev->poll_controller) 159 return; 160 161 /* Process pending work on NIC */ 162 np->dev->poll_controller(np->dev); 163 if (np->dev->poll) 164 poll_napi(np); 165 166 zap_completion_queue(); 167 } 168 169 static void refill_skbs(void) 170 { 171 struct sk_buff *skb; 172 unsigned long flags; 173 174 spin_lock_irqsave(&skb_list_lock, flags); 175 while (nr_skbs < MAX_SKBS) { 176 skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC); 177 if (!skb) 178 break; 179 180 skb->next = skbs; 181 skbs = skb; 182 nr_skbs++; 183 } 184 spin_unlock_irqrestore(&skb_list_lock, flags); 185 } 186 187 static void zap_completion_queue(void) 188 { 189 unsigned long flags; 190 struct softnet_data *sd = &get_cpu_var(softnet_data); 191 192 if (sd->completion_queue) { 193 struct sk_buff *clist; 194 195 local_irq_save(flags); 196 clist = sd->completion_queue; 197 sd->completion_queue = NULL; 198 local_irq_restore(flags); 199 200 while (clist != NULL) { 201 struct sk_buff *skb = clist; 202 clist = clist->next; 203 if(skb->destructor) 204 dev_kfree_skb_any(skb); /* put this one back */ 205 else 206 __kfree_skb(skb); 207 } 208 } 209 210 put_cpu_var(softnet_data); 211 } 212 213 static struct sk_buff * find_skb(struct netpoll *np, int len, int reserve) 214 { 215 int once = 1, count = 0; 216 unsigned long flags; 217 struct sk_buff *skb = NULL; 218 219 zap_completion_queue(); 220 repeat: 221 if (nr_skbs < MAX_SKBS) 222 refill_skbs(); 223 224 skb = alloc_skb(len, GFP_ATOMIC); 225 226 if (!skb) { 227 spin_lock_irqsave(&skb_list_lock, flags); 228 skb = skbs; 229 if (skb) { 230 skbs = skb->next; 231 skb->next = NULL; 232 nr_skbs--; 233 } 234 spin_unlock_irqrestore(&skb_list_lock, flags); 235 } 236 237 if(!skb) { 238 count++; 239 if (once && (count == 1000000)) { 240 printk("out of netpoll skbs!\n"); 241 once = 0; 242 } 243 netpoll_poll(np); 244 goto repeat; 245 } 246 247 atomic_set(&skb->users, 1); 248 skb_reserve(skb, reserve); 249 return skb; 250 } 251 252 static void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb) 253 { 254 int status; 255 struct netpoll_info *npinfo; 256 257 if (!np || !np->dev || !netif_running(np->dev)) { 258 __kfree_skb(skb); 259 return; 260 } 261 262 npinfo = np->dev->npinfo; 263 264 /* avoid recursion */ 265 if (npinfo->poll_owner == smp_processor_id() || 266 np->dev->xmit_lock_owner == smp_processor_id()) { 267 if (np->drop) 268 np->drop(skb); 269 else 270 __kfree_skb(skb); 271 return; 272 } 273 274 do { 275 npinfo->tries--; 276 netif_tx_lock(np->dev); 277 278 /* 279 * network drivers do not expect to be called if the queue is 280 * stopped. 281 */ 282 if (netif_queue_stopped(np->dev)) { 283 netif_tx_unlock(np->dev); 284 netpoll_poll(np); 285 udelay(50); 286 continue; 287 } 288 289 status = np->dev->hard_start_xmit(skb, np->dev); 290 netif_tx_unlock(np->dev); 291 292 /* success */ 293 if(!status) { 294 npinfo->tries = MAX_RETRIES; /* reset */ 295 return; 296 } 297 298 /* transmit busy */ 299 netpoll_poll(np); 300 udelay(50); 301 } while (npinfo->tries > 0); 302 } 303 304 void netpoll_send_udp(struct netpoll *np, const char *msg, int len) 305 { 306 int total_len, eth_len, ip_len, udp_len; 307 struct sk_buff *skb; 308 struct udphdr *udph; 309 struct iphdr *iph; 310 struct ethhdr *eth; 311 312 udp_len = len + sizeof(*udph); 313 ip_len = eth_len = udp_len + sizeof(*iph); 314 total_len = eth_len + ETH_HLEN + NET_IP_ALIGN; 315 316 skb = find_skb(np, total_len, total_len - len); 317 if (!skb) 318 return; 319 320 memcpy(skb->data, msg, len); 321 skb->len += len; 322 323 udph = (struct udphdr *) skb_push(skb, sizeof(*udph)); 324 udph->source = htons(np->local_port); 325 udph->dest = htons(np->remote_port); 326 udph->len = htons(udp_len); 327 udph->check = 0; 328 329 iph = (struct iphdr *)skb_push(skb, sizeof(*iph)); 330 331 /* iph->version = 4; iph->ihl = 5; */ 332 put_unaligned(0x45, (unsigned char *)iph); 333 iph->tos = 0; 334 put_unaligned(htons(ip_len), &(iph->tot_len)); 335 iph->id = 0; 336 iph->frag_off = 0; 337 iph->ttl = 64; 338 iph->protocol = IPPROTO_UDP; 339 iph->check = 0; 340 put_unaligned(htonl(np->local_ip), &(iph->saddr)); 341 put_unaligned(htonl(np->remote_ip), &(iph->daddr)); 342 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); 343 344 eth = (struct ethhdr *) skb_push(skb, ETH_HLEN); 345 346 eth->h_proto = htons(ETH_P_IP); 347 memcpy(eth->h_source, np->local_mac, 6); 348 memcpy(eth->h_dest, np->remote_mac, 6); 349 350 skb->dev = np->dev; 351 352 netpoll_send_skb(np, skb); 353 } 354 355 static void arp_reply(struct sk_buff *skb) 356 { 357 struct netpoll_info *npinfo = skb->dev->npinfo; 358 struct arphdr *arp; 359 unsigned char *arp_ptr; 360 int size, type = ARPOP_REPLY, ptype = ETH_P_ARP; 361 u32 sip, tip; 362 struct sk_buff *send_skb; 363 struct netpoll *np = NULL; 364 365 if (npinfo->rx_np && npinfo->rx_np->dev == skb->dev) 366 np = npinfo->rx_np; 367 if (!np) 368 return; 369 370 /* No arp on this interface */ 371 if (skb->dev->flags & IFF_NOARP) 372 return; 373 374 if (!pskb_may_pull(skb, (sizeof(struct arphdr) + 375 (2 * skb->dev->addr_len) + 376 (2 * sizeof(u32))))) 377 return; 378 379 skb->h.raw = skb->nh.raw = skb->data; 380 arp = skb->nh.arph; 381 382 if ((arp->ar_hrd != htons(ARPHRD_ETHER) && 383 arp->ar_hrd != htons(ARPHRD_IEEE802)) || 384 arp->ar_pro != htons(ETH_P_IP) || 385 arp->ar_op != htons(ARPOP_REQUEST)) 386 return; 387 388 arp_ptr = (unsigned char *)(arp+1) + skb->dev->addr_len; 389 memcpy(&sip, arp_ptr, 4); 390 arp_ptr += 4 + skb->dev->addr_len; 391 memcpy(&tip, arp_ptr, 4); 392 393 /* Should we ignore arp? */ 394 if (tip != htonl(np->local_ip) || LOOPBACK(tip) || MULTICAST(tip)) 395 return; 396 397 size = sizeof(struct arphdr) + 2 * (skb->dev->addr_len + 4); 398 send_skb = find_skb(np, size + LL_RESERVED_SPACE(np->dev), 399 LL_RESERVED_SPACE(np->dev)); 400 401 if (!send_skb) 402 return; 403 404 send_skb->nh.raw = send_skb->data; 405 arp = (struct arphdr *) skb_put(send_skb, size); 406 send_skb->dev = skb->dev; 407 send_skb->protocol = htons(ETH_P_ARP); 408 409 /* Fill the device header for the ARP frame */ 410 411 if (np->dev->hard_header && 412 np->dev->hard_header(send_skb, skb->dev, ptype, 413 np->remote_mac, np->local_mac, 414 send_skb->len) < 0) { 415 kfree_skb(send_skb); 416 return; 417 } 418 419 /* 420 * Fill out the arp protocol part. 421 * 422 * we only support ethernet device type, 423 * which (according to RFC 1390) should always equal 1 (Ethernet). 424 */ 425 426 arp->ar_hrd = htons(np->dev->type); 427 arp->ar_pro = htons(ETH_P_IP); 428 arp->ar_hln = np->dev->addr_len; 429 arp->ar_pln = 4; 430 arp->ar_op = htons(type); 431 432 arp_ptr=(unsigned char *)(arp + 1); 433 memcpy(arp_ptr, np->dev->dev_addr, np->dev->addr_len); 434 arp_ptr += np->dev->addr_len; 435 memcpy(arp_ptr, &tip, 4); 436 arp_ptr += 4; 437 memcpy(arp_ptr, np->remote_mac, np->dev->addr_len); 438 arp_ptr += np->dev->addr_len; 439 memcpy(arp_ptr, &sip, 4); 440 441 netpoll_send_skb(np, send_skb); 442 } 443 444 int __netpoll_rx(struct sk_buff *skb) 445 { 446 int proto, len, ulen; 447 struct iphdr *iph; 448 struct udphdr *uh; 449 struct netpoll *np = skb->dev->npinfo->rx_np; 450 451 if (!np) 452 goto out; 453 if (skb->dev->type != ARPHRD_ETHER) 454 goto out; 455 456 /* check if netpoll clients need ARP */ 457 if (skb->protocol == __constant_htons(ETH_P_ARP) && 458 atomic_read(&trapped)) { 459 arp_reply(skb); 460 return 1; 461 } 462 463 proto = ntohs(eth_hdr(skb)->h_proto); 464 if (proto != ETH_P_IP) 465 goto out; 466 if (skb->pkt_type == PACKET_OTHERHOST) 467 goto out; 468 if (skb_shared(skb)) 469 goto out; 470 471 iph = (struct iphdr *)skb->data; 472 if (!pskb_may_pull(skb, sizeof(struct iphdr))) 473 goto out; 474 if (iph->ihl < 5 || iph->version != 4) 475 goto out; 476 if (!pskb_may_pull(skb, iph->ihl*4)) 477 goto out; 478 if (ip_fast_csum((u8 *)iph, iph->ihl) != 0) 479 goto out; 480 481 len = ntohs(iph->tot_len); 482 if (skb->len < len || len < iph->ihl*4) 483 goto out; 484 485 if (iph->protocol != IPPROTO_UDP) 486 goto out; 487 488 len -= iph->ihl*4; 489 uh = (struct udphdr *)(((char *)iph) + iph->ihl*4); 490 ulen = ntohs(uh->len); 491 492 if (ulen != len) 493 goto out; 494 if (checksum_udp(skb, uh, ulen, iph->saddr, iph->daddr)) 495 goto out; 496 if (np->local_ip && np->local_ip != ntohl(iph->daddr)) 497 goto out; 498 if (np->remote_ip && np->remote_ip != ntohl(iph->saddr)) 499 goto out; 500 if (np->local_port && np->local_port != ntohs(uh->dest)) 501 goto out; 502 503 np->rx_hook(np, ntohs(uh->source), 504 (char *)(uh+1), 505 ulen - sizeof(struct udphdr)); 506 507 kfree_skb(skb); 508 return 1; 509 510 out: 511 if (atomic_read(&trapped)) { 512 kfree_skb(skb); 513 return 1; 514 } 515 516 return 0; 517 } 518 519 int netpoll_parse_options(struct netpoll *np, char *opt) 520 { 521 char *cur=opt, *delim; 522 523 if(*cur != '@') { 524 if ((delim = strchr(cur, '@')) == NULL) 525 goto parse_failed; 526 *delim=0; 527 np->local_port=simple_strtol(cur, NULL, 10); 528 cur=delim; 529 } 530 cur++; 531 printk(KERN_INFO "%s: local port %d\n", np->name, np->local_port); 532 533 if(*cur != '/') { 534 if ((delim = strchr(cur, '/')) == NULL) 535 goto parse_failed; 536 *delim=0; 537 np->local_ip=ntohl(in_aton(cur)); 538 cur=delim; 539 540 printk(KERN_INFO "%s: local IP %d.%d.%d.%d\n", 541 np->name, HIPQUAD(np->local_ip)); 542 } 543 cur++; 544 545 if ( *cur != ',') { 546 /* parse out dev name */ 547 if ((delim = strchr(cur, ',')) == NULL) 548 goto parse_failed; 549 *delim=0; 550 strlcpy(np->dev_name, cur, sizeof(np->dev_name)); 551 cur=delim; 552 } 553 cur++; 554 555 printk(KERN_INFO "%s: interface %s\n", np->name, np->dev_name); 556 557 if ( *cur != '@' ) { 558 /* dst port */ 559 if ((delim = strchr(cur, '@')) == NULL) 560 goto parse_failed; 561 *delim=0; 562 np->remote_port=simple_strtol(cur, NULL, 10); 563 cur=delim; 564 } 565 cur++; 566 printk(KERN_INFO "%s: remote port %d\n", np->name, np->remote_port); 567 568 /* dst ip */ 569 if ((delim = strchr(cur, '/')) == NULL) 570 goto parse_failed; 571 *delim=0; 572 np->remote_ip=ntohl(in_aton(cur)); 573 cur=delim+1; 574 575 printk(KERN_INFO "%s: remote IP %d.%d.%d.%d\n", 576 np->name, HIPQUAD(np->remote_ip)); 577 578 if( *cur != 0 ) 579 { 580 /* MAC address */ 581 if ((delim = strchr(cur, ':')) == NULL) 582 goto parse_failed; 583 *delim=0; 584 np->remote_mac[0]=simple_strtol(cur, NULL, 16); 585 cur=delim+1; 586 if ((delim = strchr(cur, ':')) == NULL) 587 goto parse_failed; 588 *delim=0; 589 np->remote_mac[1]=simple_strtol(cur, NULL, 16); 590 cur=delim+1; 591 if ((delim = strchr(cur, ':')) == NULL) 592 goto parse_failed; 593 *delim=0; 594 np->remote_mac[2]=simple_strtol(cur, NULL, 16); 595 cur=delim+1; 596 if ((delim = strchr(cur, ':')) == NULL) 597 goto parse_failed; 598 *delim=0; 599 np->remote_mac[3]=simple_strtol(cur, NULL, 16); 600 cur=delim+1; 601 if ((delim = strchr(cur, ':')) == NULL) 602 goto parse_failed; 603 *delim=0; 604 np->remote_mac[4]=simple_strtol(cur, NULL, 16); 605 cur=delim+1; 606 np->remote_mac[5]=simple_strtol(cur, NULL, 16); 607 } 608 609 printk(KERN_INFO "%s: remote ethernet address " 610 "%02x:%02x:%02x:%02x:%02x:%02x\n", 611 np->name, 612 np->remote_mac[0], 613 np->remote_mac[1], 614 np->remote_mac[2], 615 np->remote_mac[3], 616 np->remote_mac[4], 617 np->remote_mac[5]); 618 619 return 0; 620 621 parse_failed: 622 printk(KERN_INFO "%s: couldn't parse config at %s!\n", 623 np->name, cur); 624 return -1; 625 } 626 627 int netpoll_setup(struct netpoll *np) 628 { 629 struct net_device *ndev = NULL; 630 struct in_device *in_dev; 631 struct netpoll_info *npinfo; 632 unsigned long flags; 633 634 if (np->dev_name) 635 ndev = dev_get_by_name(np->dev_name); 636 if (!ndev) { 637 printk(KERN_ERR "%s: %s doesn't exist, aborting.\n", 638 np->name, np->dev_name); 639 return -1; 640 } 641 642 np->dev = ndev; 643 if (!ndev->npinfo) { 644 npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL); 645 if (!npinfo) 646 goto release; 647 648 npinfo->rx_flags = 0; 649 npinfo->rx_np = NULL; 650 spin_lock_init(&npinfo->poll_lock); 651 npinfo->poll_owner = -1; 652 npinfo->tries = MAX_RETRIES; 653 spin_lock_init(&npinfo->rx_lock); 654 } else 655 npinfo = ndev->npinfo; 656 657 if (!ndev->poll_controller) { 658 printk(KERN_ERR "%s: %s doesn't support polling, aborting.\n", 659 np->name, np->dev_name); 660 goto release; 661 } 662 663 if (!netif_running(ndev)) { 664 unsigned long atmost, atleast; 665 666 printk(KERN_INFO "%s: device %s not up yet, forcing it\n", 667 np->name, np->dev_name); 668 669 rtnl_lock(); 670 if (dev_change_flags(ndev, ndev->flags | IFF_UP) < 0) { 671 printk(KERN_ERR "%s: failed to open %s\n", 672 np->name, np->dev_name); 673 rtnl_unlock(); 674 goto release; 675 } 676 rtnl_unlock(); 677 678 atleast = jiffies + HZ/10; 679 atmost = jiffies + 4*HZ; 680 while (!netif_carrier_ok(ndev)) { 681 if (time_after(jiffies, atmost)) { 682 printk(KERN_NOTICE 683 "%s: timeout waiting for carrier\n", 684 np->name); 685 break; 686 } 687 cond_resched(); 688 } 689 690 /* If carrier appears to come up instantly, we don't 691 * trust it and pause so that we don't pump all our 692 * queued console messages into the bitbucket. 693 */ 694 695 if (time_before(jiffies, atleast)) { 696 printk(KERN_NOTICE "%s: carrier detect appears" 697 " untrustworthy, waiting 4 seconds\n", 698 np->name); 699 msleep(4000); 700 } 701 } 702 703 if (is_zero_ether_addr(np->local_mac) && ndev->dev_addr) 704 memcpy(np->local_mac, ndev->dev_addr, 6); 705 706 if (!np->local_ip) { 707 rcu_read_lock(); 708 in_dev = __in_dev_get_rcu(ndev); 709 710 if (!in_dev || !in_dev->ifa_list) { 711 rcu_read_unlock(); 712 printk(KERN_ERR "%s: no IP address for %s, aborting\n", 713 np->name, np->dev_name); 714 goto release; 715 } 716 717 np->local_ip = ntohl(in_dev->ifa_list->ifa_local); 718 rcu_read_unlock(); 719 printk(KERN_INFO "%s: local IP %d.%d.%d.%d\n", 720 np->name, HIPQUAD(np->local_ip)); 721 } 722 723 if (np->rx_hook) { 724 spin_lock_irqsave(&npinfo->rx_lock, flags); 725 npinfo->rx_flags |= NETPOLL_RX_ENABLED; 726 npinfo->rx_np = np; 727 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 728 } 729 730 /* fill up the skb queue */ 731 refill_skbs(); 732 733 /* last thing to do is link it to the net device structure */ 734 ndev->npinfo = npinfo; 735 736 /* avoid racing with NAPI reading npinfo */ 737 synchronize_rcu(); 738 739 return 0; 740 741 release: 742 if (!ndev->npinfo) 743 kfree(npinfo); 744 np->dev = NULL; 745 dev_put(ndev); 746 return -1; 747 } 748 749 void netpoll_cleanup(struct netpoll *np) 750 { 751 struct netpoll_info *npinfo; 752 unsigned long flags; 753 754 if (np->dev) { 755 npinfo = np->dev->npinfo; 756 if (npinfo && npinfo->rx_np == np) { 757 spin_lock_irqsave(&npinfo->rx_lock, flags); 758 npinfo->rx_np = NULL; 759 npinfo->rx_flags &= ~NETPOLL_RX_ENABLED; 760 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 761 } 762 dev_put(np->dev); 763 } 764 765 np->dev = NULL; 766 } 767 768 int netpoll_trap(void) 769 { 770 return atomic_read(&trapped); 771 } 772 773 void netpoll_set_trap(int trap) 774 { 775 if (trap) 776 atomic_inc(&trapped); 777 else 778 atomic_dec(&trapped); 779 } 780 781 EXPORT_SYMBOL(netpoll_set_trap); 782 EXPORT_SYMBOL(netpoll_trap); 783 EXPORT_SYMBOL(netpoll_parse_options); 784 EXPORT_SYMBOL(netpoll_setup); 785 EXPORT_SYMBOL(netpoll_cleanup); 786 EXPORT_SYMBOL(netpoll_send_udp); 787 EXPORT_SYMBOL(netpoll_poll); 788 EXPORT_SYMBOL(netpoll_queue); 789