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