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 unsigned int psum; 105 106 if (uh->check == 0 || skb->ip_summed == CHECKSUM_UNNECESSARY) 107 return 0; 108 109 psum = csum_tcpudp_nofold(saddr, daddr, ulen, IPPROTO_UDP, 0); 110 111 if (skb->ip_summed == CHECKSUM_HW && 112 !(u16)csum_fold(csum_add(psum, skb->csum))) 113 return 0; 114 115 skb->csum = psum; 116 117 return __skb_checksum_complete(skb); 118 } 119 120 /* 121 * Check whether delayed processing was scheduled for our NIC. If so, 122 * we attempt to grab the poll lock and use ->poll() to pump the card. 123 * If this fails, either we've recursed in ->poll() or it's already 124 * running on another CPU. 125 * 126 * Note: we don't mask interrupts with this lock because we're using 127 * trylock here and interrupts are already disabled in the softirq 128 * case. Further, we test the poll_owner to avoid recursion on UP 129 * systems where the lock doesn't exist. 130 * 131 * In cases where there is bi-directional communications, reading only 132 * one message at a time can lead to packets being dropped by the 133 * network adapter, forcing superfluous retries and possibly timeouts. 134 * Thus, we set our budget to greater than 1. 135 */ 136 static void poll_napi(struct netpoll *np) 137 { 138 struct netpoll_info *npinfo = np->dev->npinfo; 139 int budget = 16; 140 141 if (test_bit(__LINK_STATE_RX_SCHED, &np->dev->state) && 142 npinfo->poll_owner != smp_processor_id() && 143 spin_trylock(&npinfo->poll_lock)) { 144 npinfo->rx_flags |= NETPOLL_RX_DROP; 145 atomic_inc(&trapped); 146 147 np->dev->poll(np->dev, &budget); 148 149 atomic_dec(&trapped); 150 npinfo->rx_flags &= ~NETPOLL_RX_DROP; 151 spin_unlock(&npinfo->poll_lock); 152 } 153 } 154 155 void netpoll_poll(struct netpoll *np) 156 { 157 if(!np->dev || !netif_running(np->dev) || !np->dev->poll_controller) 158 return; 159 160 /* Process pending work on NIC */ 161 np->dev->poll_controller(np->dev); 162 if (np->dev->poll) 163 poll_napi(np); 164 165 zap_completion_queue(); 166 } 167 168 static void refill_skbs(void) 169 { 170 struct sk_buff *skb; 171 unsigned long flags; 172 173 spin_lock_irqsave(&skb_list_lock, flags); 174 while (nr_skbs < MAX_SKBS) { 175 skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC); 176 if (!skb) 177 break; 178 179 skb->next = skbs; 180 skbs = skb; 181 nr_skbs++; 182 } 183 spin_unlock_irqrestore(&skb_list_lock, flags); 184 } 185 186 static void zap_completion_queue(void) 187 { 188 unsigned long flags; 189 struct softnet_data *sd = &get_cpu_var(softnet_data); 190 191 if (sd->completion_queue) { 192 struct sk_buff *clist; 193 194 local_irq_save(flags); 195 clist = sd->completion_queue; 196 sd->completion_queue = NULL; 197 local_irq_restore(flags); 198 199 while (clist != NULL) { 200 struct sk_buff *skb = clist; 201 clist = clist->next; 202 if(skb->destructor) 203 dev_kfree_skb_any(skb); /* put this one back */ 204 else 205 __kfree_skb(skb); 206 } 207 } 208 209 put_cpu_var(softnet_data); 210 } 211 212 static struct sk_buff * find_skb(struct netpoll *np, int len, int reserve) 213 { 214 int once = 1, count = 0; 215 unsigned long flags; 216 struct sk_buff *skb = NULL; 217 218 zap_completion_queue(); 219 repeat: 220 if (nr_skbs < MAX_SKBS) 221 refill_skbs(); 222 223 skb = alloc_skb(len, GFP_ATOMIC); 224 225 if (!skb) { 226 spin_lock_irqsave(&skb_list_lock, flags); 227 skb = skbs; 228 if (skb) { 229 skbs = skb->next; 230 skb->next = NULL; 231 nr_skbs--; 232 } 233 spin_unlock_irqrestore(&skb_list_lock, flags); 234 } 235 236 if(!skb) { 237 count++; 238 if (once && (count == 1000000)) { 239 printk("out of netpoll skbs!\n"); 240 once = 0; 241 } 242 netpoll_poll(np); 243 goto repeat; 244 } 245 246 atomic_set(&skb->users, 1); 247 skb_reserve(skb, reserve); 248 return skb; 249 } 250 251 static void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb) 252 { 253 int status; 254 struct netpoll_info *npinfo; 255 256 if (!np || !np->dev || !netif_running(np->dev)) { 257 __kfree_skb(skb); 258 return; 259 } 260 261 npinfo = np->dev->npinfo; 262 263 /* avoid recursion */ 264 if (npinfo->poll_owner == smp_processor_id() || 265 np->dev->xmit_lock_owner == smp_processor_id()) { 266 if (np->drop) 267 np->drop(skb); 268 else 269 __kfree_skb(skb); 270 return; 271 } 272 273 do { 274 npinfo->tries--; 275 spin_lock(&np->dev->xmit_lock); 276 np->dev->xmit_lock_owner = smp_processor_id(); 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 np->dev->xmit_lock_owner = -1; 284 spin_unlock(&np->dev->xmit_lock); 285 netpoll_poll(np); 286 udelay(50); 287 continue; 288 } 289 290 status = np->dev->hard_start_xmit(skb, np->dev); 291 np->dev->xmit_lock_owner = -1; 292 spin_unlock(&np->dev->xmit_lock); 293 294 /* success */ 295 if(!status) { 296 npinfo->tries = MAX_RETRIES; /* reset */ 297 return; 298 } 299 300 /* transmit busy */ 301 netpoll_poll(np); 302 udelay(50); 303 } while (npinfo->tries > 0); 304 } 305 306 void netpoll_send_udp(struct netpoll *np, const char *msg, int len) 307 { 308 int total_len, eth_len, ip_len, udp_len; 309 struct sk_buff *skb; 310 struct udphdr *udph; 311 struct iphdr *iph; 312 struct ethhdr *eth; 313 314 udp_len = len + sizeof(*udph); 315 ip_len = eth_len = udp_len + sizeof(*iph); 316 total_len = eth_len + ETH_HLEN + NET_IP_ALIGN; 317 318 skb = find_skb(np, total_len, total_len - len); 319 if (!skb) 320 return; 321 322 memcpy(skb->data, msg, len); 323 skb->len += len; 324 325 udph = (struct udphdr *) skb_push(skb, sizeof(*udph)); 326 udph->source = htons(np->local_port); 327 udph->dest = htons(np->remote_port); 328 udph->len = htons(udp_len); 329 udph->check = 0; 330 331 iph = (struct iphdr *)skb_push(skb, sizeof(*iph)); 332 333 /* iph->version = 4; iph->ihl = 5; */ 334 put_unaligned(0x45, (unsigned char *)iph); 335 iph->tos = 0; 336 put_unaligned(htons(ip_len), &(iph->tot_len)); 337 iph->id = 0; 338 iph->frag_off = 0; 339 iph->ttl = 64; 340 iph->protocol = IPPROTO_UDP; 341 iph->check = 0; 342 put_unaligned(htonl(np->local_ip), &(iph->saddr)); 343 put_unaligned(htonl(np->remote_ip), &(iph->daddr)); 344 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); 345 346 eth = (struct ethhdr *) skb_push(skb, ETH_HLEN); 347 348 eth->h_proto = htons(ETH_P_IP); 349 memcpy(eth->h_source, np->local_mac, 6); 350 memcpy(eth->h_dest, np->remote_mac, 6); 351 352 skb->dev = np->dev; 353 354 netpoll_send_skb(np, skb); 355 } 356 357 static void arp_reply(struct sk_buff *skb) 358 { 359 struct netpoll_info *npinfo = skb->dev->npinfo; 360 struct arphdr *arp; 361 unsigned char *arp_ptr; 362 int size, type = ARPOP_REPLY, ptype = ETH_P_ARP; 363 u32 sip, tip; 364 struct sk_buff *send_skb; 365 struct netpoll *np = NULL; 366 367 if (npinfo->rx_np && npinfo->rx_np->dev == skb->dev) 368 np = npinfo->rx_np; 369 if (!np) 370 return; 371 372 /* No arp on this interface */ 373 if (skb->dev->flags & IFF_NOARP) 374 return; 375 376 if (!pskb_may_pull(skb, (sizeof(struct arphdr) + 377 (2 * skb->dev->addr_len) + 378 (2 * sizeof(u32))))) 379 return; 380 381 skb->h.raw = skb->nh.raw = skb->data; 382 arp = skb->nh.arph; 383 384 if ((arp->ar_hrd != htons(ARPHRD_ETHER) && 385 arp->ar_hrd != htons(ARPHRD_IEEE802)) || 386 arp->ar_pro != htons(ETH_P_IP) || 387 arp->ar_op != htons(ARPOP_REQUEST)) 388 return; 389 390 arp_ptr = (unsigned char *)(arp+1) + skb->dev->addr_len; 391 memcpy(&sip, arp_ptr, 4); 392 arp_ptr += 4 + skb->dev->addr_len; 393 memcpy(&tip, arp_ptr, 4); 394 395 /* Should we ignore arp? */ 396 if (tip != htonl(np->local_ip) || LOOPBACK(tip) || MULTICAST(tip)) 397 return; 398 399 size = sizeof(struct arphdr) + 2 * (skb->dev->addr_len + 4); 400 send_skb = find_skb(np, size + LL_RESERVED_SPACE(np->dev), 401 LL_RESERVED_SPACE(np->dev)); 402 403 if (!send_skb) 404 return; 405 406 send_skb->nh.raw = send_skb->data; 407 arp = (struct arphdr *) skb_put(send_skb, size); 408 send_skb->dev = skb->dev; 409 send_skb->protocol = htons(ETH_P_ARP); 410 411 /* Fill the device header for the ARP frame */ 412 413 if (np->dev->hard_header && 414 np->dev->hard_header(send_skb, skb->dev, ptype, 415 np->remote_mac, np->local_mac, 416 send_skb->len) < 0) { 417 kfree_skb(send_skb); 418 return; 419 } 420 421 /* 422 * Fill out the arp protocol part. 423 * 424 * we only support ethernet device type, 425 * which (according to RFC 1390) should always equal 1 (Ethernet). 426 */ 427 428 arp->ar_hrd = htons(np->dev->type); 429 arp->ar_pro = htons(ETH_P_IP); 430 arp->ar_hln = np->dev->addr_len; 431 arp->ar_pln = 4; 432 arp->ar_op = htons(type); 433 434 arp_ptr=(unsigned char *)(arp + 1); 435 memcpy(arp_ptr, np->dev->dev_addr, np->dev->addr_len); 436 arp_ptr += np->dev->addr_len; 437 memcpy(arp_ptr, &tip, 4); 438 arp_ptr += 4; 439 memcpy(arp_ptr, np->remote_mac, np->dev->addr_len); 440 arp_ptr += np->dev->addr_len; 441 memcpy(arp_ptr, &sip, 4); 442 443 netpoll_send_skb(np, send_skb); 444 } 445 446 int __netpoll_rx(struct sk_buff *skb) 447 { 448 int proto, len, ulen; 449 struct iphdr *iph; 450 struct udphdr *uh; 451 struct netpoll *np = skb->dev->npinfo->rx_np; 452 453 if (!np) 454 goto out; 455 if (skb->dev->type != ARPHRD_ETHER) 456 goto out; 457 458 /* check if netpoll clients need ARP */ 459 if (skb->protocol == __constant_htons(ETH_P_ARP) && 460 atomic_read(&trapped)) { 461 arp_reply(skb); 462 return 1; 463 } 464 465 proto = ntohs(eth_hdr(skb)->h_proto); 466 if (proto != ETH_P_IP) 467 goto out; 468 if (skb->pkt_type == PACKET_OTHERHOST) 469 goto out; 470 if (skb_shared(skb)) 471 goto out; 472 473 iph = (struct iphdr *)skb->data; 474 if (!pskb_may_pull(skb, sizeof(struct iphdr))) 475 goto out; 476 if (iph->ihl < 5 || iph->version != 4) 477 goto out; 478 if (!pskb_may_pull(skb, iph->ihl*4)) 479 goto out; 480 if (ip_fast_csum((u8 *)iph, iph->ihl) != 0) 481 goto out; 482 483 len = ntohs(iph->tot_len); 484 if (skb->len < len || len < iph->ihl*4) 485 goto out; 486 487 if (iph->protocol != IPPROTO_UDP) 488 goto out; 489 490 len -= iph->ihl*4; 491 uh = (struct udphdr *)(((char *)iph) + iph->ihl*4); 492 ulen = ntohs(uh->len); 493 494 if (ulen != len) 495 goto out; 496 if (checksum_udp(skb, uh, ulen, iph->saddr, iph->daddr)) 497 goto out; 498 if (np->local_ip && np->local_ip != ntohl(iph->daddr)) 499 goto out; 500 if (np->remote_ip && np->remote_ip != ntohl(iph->saddr)) 501 goto out; 502 if (np->local_port && np->local_port != ntohs(uh->dest)) 503 goto out; 504 505 np->rx_hook(np, ntohs(uh->source), 506 (char *)(uh+1), 507 ulen - sizeof(struct udphdr)); 508 509 kfree_skb(skb); 510 return 1; 511 512 out: 513 if (atomic_read(&trapped)) { 514 kfree_skb(skb); 515 return 1; 516 } 517 518 return 0; 519 } 520 521 int netpoll_parse_options(struct netpoll *np, char *opt) 522 { 523 char *cur=opt, *delim; 524 525 if(*cur != '@') { 526 if ((delim = strchr(cur, '@')) == NULL) 527 goto parse_failed; 528 *delim=0; 529 np->local_port=simple_strtol(cur, NULL, 10); 530 cur=delim; 531 } 532 cur++; 533 printk(KERN_INFO "%s: local port %d\n", np->name, np->local_port); 534 535 if(*cur != '/') { 536 if ((delim = strchr(cur, '/')) == NULL) 537 goto parse_failed; 538 *delim=0; 539 np->local_ip=ntohl(in_aton(cur)); 540 cur=delim; 541 542 printk(KERN_INFO "%s: local IP %d.%d.%d.%d\n", 543 np->name, HIPQUAD(np->local_ip)); 544 } 545 cur++; 546 547 if ( *cur != ',') { 548 /* parse out dev name */ 549 if ((delim = strchr(cur, ',')) == NULL) 550 goto parse_failed; 551 *delim=0; 552 strlcpy(np->dev_name, cur, sizeof(np->dev_name)); 553 cur=delim; 554 } 555 cur++; 556 557 printk(KERN_INFO "%s: interface %s\n", np->name, np->dev_name); 558 559 if ( *cur != '@' ) { 560 /* dst port */ 561 if ((delim = strchr(cur, '@')) == NULL) 562 goto parse_failed; 563 *delim=0; 564 np->remote_port=simple_strtol(cur, NULL, 10); 565 cur=delim; 566 } 567 cur++; 568 printk(KERN_INFO "%s: remote port %d\n", np->name, np->remote_port); 569 570 /* dst ip */ 571 if ((delim = strchr(cur, '/')) == NULL) 572 goto parse_failed; 573 *delim=0; 574 np->remote_ip=ntohl(in_aton(cur)); 575 cur=delim+1; 576 577 printk(KERN_INFO "%s: remote IP %d.%d.%d.%d\n", 578 np->name, HIPQUAD(np->remote_ip)); 579 580 if( *cur != 0 ) 581 { 582 /* MAC address */ 583 if ((delim = strchr(cur, ':')) == NULL) 584 goto parse_failed; 585 *delim=0; 586 np->remote_mac[0]=simple_strtol(cur, NULL, 16); 587 cur=delim+1; 588 if ((delim = strchr(cur, ':')) == NULL) 589 goto parse_failed; 590 *delim=0; 591 np->remote_mac[1]=simple_strtol(cur, NULL, 16); 592 cur=delim+1; 593 if ((delim = strchr(cur, ':')) == NULL) 594 goto parse_failed; 595 *delim=0; 596 np->remote_mac[2]=simple_strtol(cur, NULL, 16); 597 cur=delim+1; 598 if ((delim = strchr(cur, ':')) == NULL) 599 goto parse_failed; 600 *delim=0; 601 np->remote_mac[3]=simple_strtol(cur, NULL, 16); 602 cur=delim+1; 603 if ((delim = strchr(cur, ':')) == NULL) 604 goto parse_failed; 605 *delim=0; 606 np->remote_mac[4]=simple_strtol(cur, NULL, 16); 607 cur=delim+1; 608 np->remote_mac[5]=simple_strtol(cur, NULL, 16); 609 } 610 611 printk(KERN_INFO "%s: remote ethernet address " 612 "%02x:%02x:%02x:%02x:%02x:%02x\n", 613 np->name, 614 np->remote_mac[0], 615 np->remote_mac[1], 616 np->remote_mac[2], 617 np->remote_mac[3], 618 np->remote_mac[4], 619 np->remote_mac[5]); 620 621 return 0; 622 623 parse_failed: 624 printk(KERN_INFO "%s: couldn't parse config at %s!\n", 625 np->name, cur); 626 return -1; 627 } 628 629 int netpoll_setup(struct netpoll *np) 630 { 631 struct net_device *ndev = NULL; 632 struct in_device *in_dev; 633 struct netpoll_info *npinfo; 634 unsigned long flags; 635 636 if (np->dev_name) 637 ndev = dev_get_by_name(np->dev_name); 638 if (!ndev) { 639 printk(KERN_ERR "%s: %s doesn't exist, aborting.\n", 640 np->name, np->dev_name); 641 return -1; 642 } 643 644 np->dev = ndev; 645 if (!ndev->npinfo) { 646 npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL); 647 if (!npinfo) 648 goto release; 649 650 npinfo->rx_flags = 0; 651 npinfo->rx_np = NULL; 652 spin_lock_init(&npinfo->poll_lock); 653 npinfo->poll_owner = -1; 654 npinfo->tries = MAX_RETRIES; 655 spin_lock_init(&npinfo->rx_lock); 656 } else 657 npinfo = ndev->npinfo; 658 659 if (!ndev->poll_controller) { 660 printk(KERN_ERR "%s: %s doesn't support polling, aborting.\n", 661 np->name, np->dev_name); 662 goto release; 663 } 664 665 if (!netif_running(ndev)) { 666 unsigned long atmost, atleast; 667 668 printk(KERN_INFO "%s: device %s not up yet, forcing it\n", 669 np->name, np->dev_name); 670 671 rtnl_shlock(); 672 if (dev_change_flags(ndev, ndev->flags | IFF_UP) < 0) { 673 printk(KERN_ERR "%s: failed to open %s\n", 674 np->name, np->dev_name); 675 rtnl_shunlock(); 676 goto release; 677 } 678 rtnl_shunlock(); 679 680 atleast = jiffies + HZ/10; 681 atmost = jiffies + 4*HZ; 682 while (!netif_carrier_ok(ndev)) { 683 if (time_after(jiffies, atmost)) { 684 printk(KERN_NOTICE 685 "%s: timeout waiting for carrier\n", 686 np->name); 687 break; 688 } 689 cond_resched(); 690 } 691 692 /* If carrier appears to come up instantly, we don't 693 * trust it and pause so that we don't pump all our 694 * queued console messages into the bitbucket. 695 */ 696 697 if (time_before(jiffies, atleast)) { 698 printk(KERN_NOTICE "%s: carrier detect appears" 699 " untrustworthy, waiting 4 seconds\n", 700 np->name); 701 msleep(4000); 702 } 703 } 704 705 if (!memcmp(np->local_mac, "\0\0\0\0\0\0", 6) && ndev->dev_addr) 706 memcpy(np->local_mac, ndev->dev_addr, 6); 707 708 if (!np->local_ip) { 709 rcu_read_lock(); 710 in_dev = __in_dev_get_rcu(ndev); 711 712 if (!in_dev || !in_dev->ifa_list) { 713 rcu_read_unlock(); 714 printk(KERN_ERR "%s: no IP address for %s, aborting\n", 715 np->name, np->dev_name); 716 goto release; 717 } 718 719 np->local_ip = ntohl(in_dev->ifa_list->ifa_local); 720 rcu_read_unlock(); 721 printk(KERN_INFO "%s: local IP %d.%d.%d.%d\n", 722 np->name, HIPQUAD(np->local_ip)); 723 } 724 725 if (np->rx_hook) { 726 spin_lock_irqsave(&npinfo->rx_lock, flags); 727 npinfo->rx_flags |= NETPOLL_RX_ENABLED; 728 npinfo->rx_np = np; 729 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 730 } 731 732 /* fill up the skb queue */ 733 refill_skbs(); 734 735 /* last thing to do is link it to the net device structure */ 736 ndev->npinfo = npinfo; 737 738 /* avoid racing with NAPI reading npinfo */ 739 synchronize_rcu(); 740 741 return 0; 742 743 release: 744 if (!ndev->npinfo) 745 kfree(npinfo); 746 np->dev = NULL; 747 dev_put(ndev); 748 return -1; 749 } 750 751 void netpoll_cleanup(struct netpoll *np) 752 { 753 struct netpoll_info *npinfo; 754 unsigned long flags; 755 756 if (np->dev) { 757 npinfo = np->dev->npinfo; 758 if (npinfo && npinfo->rx_np == np) { 759 spin_lock_irqsave(&npinfo->rx_lock, flags); 760 npinfo->rx_np = NULL; 761 npinfo->rx_flags &= ~NETPOLL_RX_ENABLED; 762 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 763 } 764 dev_put(np->dev); 765 } 766 767 np->dev = NULL; 768 } 769 770 int netpoll_trap(void) 771 { 772 return atomic_read(&trapped); 773 } 774 775 void netpoll_set_trap(int trap) 776 { 777 if (trap) 778 atomic_inc(&trapped); 779 else 780 atomic_dec(&trapped); 781 } 782 783 EXPORT_SYMBOL(netpoll_set_trap); 784 EXPORT_SYMBOL(netpoll_trap); 785 EXPORT_SYMBOL(netpoll_parse_options); 786 EXPORT_SYMBOL(netpoll_setup); 787 EXPORT_SYMBOL(netpoll_cleanup); 788 EXPORT_SYMBOL(netpoll_send_udp); 789 EXPORT_SYMBOL(netpoll_poll); 790 EXPORT_SYMBOL(netpoll_queue); 791