netpoll.c revision 724800d61b8bc574a364707b6a6c6a6252e8cdb4
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 38static struct sk_buff_head skb_pool; 39 40static atomic_t trapped; 41 42#define USEC_PER_POLL 50 43#define NETPOLL_RX_ENABLED 1 44#define NETPOLL_RX_DROP 2 45 46#define MAX_SKB_SIZE \ 47 (MAX_UDP_CHUNK + sizeof(struct udphdr) + \ 48 sizeof(struct iphdr) + sizeof(struct ethhdr)) 49 50static void zap_completion_queue(void); 51static void arp_reply(struct sk_buff *skb); 52 53static void queue_process(struct work_struct *work) 54{ 55 struct netpoll_info *npinfo = 56 container_of(work, struct netpoll_info, tx_work.work); 57 struct sk_buff *skb; 58 unsigned long flags; 59 60 while ((skb = skb_dequeue(&npinfo->txq))) { 61 struct net_device *dev = skb->dev; 62 63 if (!netif_device_present(dev) || !netif_running(dev)) { 64 __kfree_skb(skb); 65 continue; 66 } 67 68 local_irq_save(flags); 69 netif_tx_lock(dev); 70 if (netif_queue_stopped(dev) || 71 dev->hard_start_xmit(skb, dev) != NETDEV_TX_OK) { 72 skb_queue_head(&npinfo->txq, skb); 73 netif_tx_unlock(dev); 74 local_irq_restore(flags); 75 76 schedule_delayed_work(&npinfo->tx_work, HZ/10); 77 return; 78 } 79 netif_tx_unlock(dev); 80 local_irq_restore(flags); 81 } 82} 83 84static __sum16 checksum_udp(struct sk_buff *skb, struct udphdr *uh, 85 unsigned short ulen, __be32 saddr, __be32 daddr) 86{ 87 __wsum psum; 88 89 if (uh->check == 0 || skb->ip_summed == CHECKSUM_UNNECESSARY) 90 return 0; 91 92 psum = csum_tcpudp_nofold(saddr, daddr, ulen, IPPROTO_UDP, 0); 93 94 if (skb->ip_summed == CHECKSUM_COMPLETE && 95 !csum_fold(csum_add(psum, skb->csum))) 96 return 0; 97 98 skb->csum = psum; 99 100 return __skb_checksum_complete(skb); 101} 102 103/* 104 * Check whether delayed processing was scheduled for our NIC. If so, 105 * we attempt to grab the poll lock and use ->poll() to pump the card. 106 * If this fails, either we've recursed in ->poll() or it's already 107 * running on another CPU. 108 * 109 * Note: we don't mask interrupts with this lock because we're using 110 * trylock here and interrupts are already disabled in the softirq 111 * case. Further, we test the poll_owner to avoid recursion on UP 112 * systems where the lock doesn't exist. 113 * 114 * In cases where there is bi-directional communications, reading only 115 * one message at a time can lead to packets being dropped by the 116 * network adapter, forcing superfluous retries and possibly timeouts. 117 * Thus, we set our budget to greater than 1. 118 */ 119static void poll_napi(struct netpoll *np) 120{ 121 struct netpoll_info *npinfo = np->dev->npinfo; 122 int budget = 16; 123 124 if (test_bit(__LINK_STATE_RX_SCHED, &np->dev->state) && 125 npinfo->poll_owner != smp_processor_id() && 126 spin_trylock(&npinfo->poll_lock)) { 127 npinfo->rx_flags |= NETPOLL_RX_DROP; 128 atomic_inc(&trapped); 129 130 np->dev->poll(np->dev, &budget); 131 132 atomic_dec(&trapped); 133 npinfo->rx_flags &= ~NETPOLL_RX_DROP; 134 spin_unlock(&npinfo->poll_lock); 135 } 136} 137 138static void service_arp_queue(struct netpoll_info *npi) 139{ 140 struct sk_buff *skb; 141 142 if (unlikely(!npi)) 143 return; 144 145 skb = skb_dequeue(&npi->arp_tx); 146 147 while (skb != NULL) { 148 arp_reply(skb); 149 skb = skb_dequeue(&npi->arp_tx); 150 } 151} 152 153void netpoll_poll(struct netpoll *np) 154{ 155 if (!np->dev || !netif_running(np->dev) || !np->dev->poll_controller) 156 return; 157 158 /* Process pending work on NIC */ 159 np->dev->poll_controller(np->dev); 160 if (np->dev->poll) 161 poll_napi(np); 162 163 service_arp_queue(np->dev->npinfo); 164 165 zap_completion_queue(); 166} 167 168static void refill_skbs(void) 169{ 170 struct sk_buff *skb; 171 unsigned long flags; 172 173 spin_lock_irqsave(&skb_pool.lock, flags); 174 while (skb_pool.qlen < MAX_SKBS) { 175 skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC); 176 if (!skb) 177 break; 178 179 __skb_queue_tail(&skb_pool, skb); 180 } 181 spin_unlock_irqrestore(&skb_pool.lock, flags); 182} 183 184static void zap_completion_queue(void) 185{ 186 unsigned long flags; 187 struct softnet_data *sd = &get_cpu_var(softnet_data); 188 189 if (sd->completion_queue) { 190 struct sk_buff *clist; 191 192 local_irq_save(flags); 193 clist = sd->completion_queue; 194 sd->completion_queue = NULL; 195 local_irq_restore(flags); 196 197 while (clist != NULL) { 198 struct sk_buff *skb = clist; 199 clist = clist->next; 200 if (skb->destructor) 201 dev_kfree_skb_any(skb); /* put this one back */ 202 else 203 __kfree_skb(skb); 204 } 205 } 206 207 put_cpu_var(softnet_data); 208} 209 210static struct sk_buff *find_skb(struct netpoll *np, int len, int reserve) 211{ 212 int count = 0; 213 struct sk_buff *skb; 214 215 zap_completion_queue(); 216 refill_skbs(); 217repeat: 218 219 skb = alloc_skb(len, GFP_ATOMIC); 220 if (!skb) 221 skb = skb_dequeue(&skb_pool); 222 223 if (!skb) { 224 if (++count < 10) { 225 netpoll_poll(np); 226 goto repeat; 227 } 228 return NULL; 229 } 230 231 atomic_set(&skb->users, 1); 232 skb_reserve(skb, reserve); 233 return skb; 234} 235 236static void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb) 237{ 238 int status = NETDEV_TX_BUSY; 239 unsigned long tries; 240 struct net_device *dev = np->dev; 241 struct netpoll_info *npinfo = np->dev->npinfo; 242 243 if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) { 244 __kfree_skb(skb); 245 return; 246 } 247 248 /* don't get messages out of order, and no recursion */ 249 if (skb_queue_len(&npinfo->txq) == 0 && 250 npinfo->poll_owner != smp_processor_id()) { 251 unsigned long flags; 252 253 local_irq_save(flags); 254 if (netif_tx_trylock(dev)) { 255 /* try until next clock tick */ 256 for (tries = jiffies_to_usecs(1)/USEC_PER_POLL; 257 tries > 0; --tries) { 258 if (!netif_queue_stopped(dev)) 259 status = dev->hard_start_xmit(skb, dev); 260 261 if (status == NETDEV_TX_OK) 262 break; 263 264 /* tickle device maybe there is some cleanup */ 265 netpoll_poll(np); 266 267 udelay(USEC_PER_POLL); 268 } 269 netif_tx_unlock(dev); 270 } 271 local_irq_restore(flags); 272 } 273 274 if (status != NETDEV_TX_OK) { 275 skb_queue_tail(&npinfo->txq, skb); 276 schedule_delayed_work(&npinfo->tx_work,0); 277 } 278} 279 280void netpoll_send_udp(struct netpoll *np, const char *msg, int len) 281{ 282 int total_len, eth_len, ip_len, udp_len; 283 struct sk_buff *skb; 284 struct udphdr *udph; 285 struct iphdr *iph; 286 struct ethhdr *eth; 287 288 udp_len = len + sizeof(*udph); 289 ip_len = eth_len = udp_len + sizeof(*iph); 290 total_len = eth_len + ETH_HLEN + NET_IP_ALIGN; 291 292 skb = find_skb(np, total_len, total_len - len); 293 if (!skb) 294 return; 295 296 memcpy(skb->data, msg, len); 297 skb->len += len; 298 299 skb->h.uh = udph = (struct udphdr *) skb_push(skb, sizeof(*udph)); 300 udph->source = htons(np->local_port); 301 udph->dest = htons(np->remote_port); 302 udph->len = htons(udp_len); 303 udph->check = 0; 304 udph->check = csum_tcpudp_magic(htonl(np->local_ip), 305 htonl(np->remote_ip), 306 udp_len, IPPROTO_UDP, 307 csum_partial((unsigned char *)udph, udp_len, 0)); 308 if (udph->check == 0) 309 udph->check = CSUM_MANGLED_0; 310 311 skb->nh.iph = iph = (struct iphdr *)skb_push(skb, sizeof(*iph)); 312 313 /* iph->version = 4; iph->ihl = 5; */ 314 put_unaligned(0x45, (unsigned char *)iph); 315 iph->tos = 0; 316 put_unaligned(htons(ip_len), &(iph->tot_len)); 317 iph->id = 0; 318 iph->frag_off = 0; 319 iph->ttl = 64; 320 iph->protocol = IPPROTO_UDP; 321 iph->check = 0; 322 put_unaligned(htonl(np->local_ip), &(iph->saddr)); 323 put_unaligned(htonl(np->remote_ip), &(iph->daddr)); 324 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); 325 326 eth = (struct ethhdr *) skb_push(skb, ETH_HLEN); 327 skb->mac.raw = skb->data; 328 skb->protocol = eth->h_proto = htons(ETH_P_IP); 329 memcpy(eth->h_source, np->local_mac, 6); 330 memcpy(eth->h_dest, np->remote_mac, 6); 331 332 skb->dev = np->dev; 333 334 netpoll_send_skb(np, skb); 335} 336 337static void arp_reply(struct sk_buff *skb) 338{ 339 struct netpoll_info *npinfo = skb->dev->npinfo; 340 struct arphdr *arp; 341 unsigned char *arp_ptr; 342 int size, type = ARPOP_REPLY, ptype = ETH_P_ARP; 343 __be32 sip, tip; 344 unsigned char *sha; 345 struct sk_buff *send_skb; 346 struct netpoll *np = NULL; 347 348 if (npinfo->rx_np && npinfo->rx_np->dev == skb->dev) 349 np = npinfo->rx_np; 350 if (!np) 351 return; 352 353 /* No arp on this interface */ 354 if (skb->dev->flags & IFF_NOARP) 355 return; 356 357 if (!pskb_may_pull(skb, (sizeof(struct arphdr) + 358 (2 * skb->dev->addr_len) + 359 (2 * sizeof(u32))))) 360 return; 361 362 skb->h.raw = skb->nh.raw = skb->data; 363 arp = skb->nh.arph; 364 365 if ((arp->ar_hrd != htons(ARPHRD_ETHER) && 366 arp->ar_hrd != htons(ARPHRD_IEEE802)) || 367 arp->ar_pro != htons(ETH_P_IP) || 368 arp->ar_op != htons(ARPOP_REQUEST)) 369 return; 370 371 arp_ptr = (unsigned char *)(arp+1); 372 /* save the location of the src hw addr */ 373 sha = arp_ptr; 374 arp_ptr += skb->dev->addr_len; 375 memcpy(&sip, arp_ptr, 4); 376 arp_ptr += 4; 377 /* if we actually cared about dst hw addr, it would get copied here */ 378 arp_ptr += skb->dev->addr_len; 379 memcpy(&tip, arp_ptr, 4); 380 381 /* Should we ignore arp? */ 382 if (tip != htonl(np->local_ip) || LOOPBACK(tip) || MULTICAST(tip)) 383 return; 384 385 size = sizeof(struct arphdr) + 2 * (skb->dev->addr_len + 4); 386 send_skb = find_skb(np, size + LL_RESERVED_SPACE(np->dev), 387 LL_RESERVED_SPACE(np->dev)); 388 389 if (!send_skb) 390 return; 391 392 send_skb->nh.raw = send_skb->data; 393 arp = (struct arphdr *) skb_put(send_skb, size); 394 send_skb->dev = skb->dev; 395 send_skb->protocol = htons(ETH_P_ARP); 396 397 /* Fill the device header for the ARP frame */ 398 399 if (np->dev->hard_header && 400 np->dev->hard_header(send_skb, skb->dev, ptype, 401 sha, np->local_mac, 402 send_skb->len) < 0) { 403 kfree_skb(send_skb); 404 return; 405 } 406 407 /* 408 * Fill out the arp protocol part. 409 * 410 * we only support ethernet device type, 411 * which (according to RFC 1390) should always equal 1 (Ethernet). 412 */ 413 414 arp->ar_hrd = htons(np->dev->type); 415 arp->ar_pro = htons(ETH_P_IP); 416 arp->ar_hln = np->dev->addr_len; 417 arp->ar_pln = 4; 418 arp->ar_op = htons(type); 419 420 arp_ptr=(unsigned char *)(arp + 1); 421 memcpy(arp_ptr, np->dev->dev_addr, np->dev->addr_len); 422 arp_ptr += np->dev->addr_len; 423 memcpy(arp_ptr, &tip, 4); 424 arp_ptr += 4; 425 memcpy(arp_ptr, sha, np->dev->addr_len); 426 arp_ptr += np->dev->addr_len; 427 memcpy(arp_ptr, &sip, 4); 428 429 netpoll_send_skb(np, send_skb); 430} 431 432int __netpoll_rx(struct sk_buff *skb) 433{ 434 int proto, len, ulen; 435 struct iphdr *iph; 436 struct udphdr *uh; 437 struct netpoll_info *npi = skb->dev->npinfo; 438 struct netpoll *np = npi->rx_np; 439 440 if (!np) 441 goto out; 442 if (skb->dev->type != ARPHRD_ETHER) 443 goto out; 444 445 /* check if netpoll clients need ARP */ 446 if (skb->protocol == htons(ETH_P_ARP) && 447 atomic_read(&trapped)) { 448 skb_queue_tail(&npi->arp_tx, skb); 449 return 1; 450 } 451 452 proto = ntohs(eth_hdr(skb)->h_proto); 453 if (proto != ETH_P_IP) 454 goto out; 455 if (skb->pkt_type == PACKET_OTHERHOST) 456 goto out; 457 if (skb_shared(skb)) 458 goto out; 459 460 iph = (struct iphdr *)skb->data; 461 if (!pskb_may_pull(skb, sizeof(struct iphdr))) 462 goto out; 463 if (iph->ihl < 5 || iph->version != 4) 464 goto out; 465 if (!pskb_may_pull(skb, iph->ihl*4)) 466 goto out; 467 if (ip_fast_csum((u8 *)iph, iph->ihl) != 0) 468 goto out; 469 470 len = ntohs(iph->tot_len); 471 if (skb->len < len || len < iph->ihl*4) 472 goto out; 473 474 /* 475 * Our transport medium may have padded the buffer out. 476 * Now We trim to the true length of the frame. 477 */ 478 if (pskb_trim_rcsum(skb, len)) 479 goto out; 480 481 if (iph->protocol != IPPROTO_UDP) 482 goto out; 483 484 len -= iph->ihl*4; 485 uh = (struct udphdr *)(((char *)iph) + iph->ihl*4); 486 ulen = ntohs(uh->len); 487 488 if (ulen != len) 489 goto out; 490 if (checksum_udp(skb, uh, ulen, iph->saddr, iph->daddr)) 491 goto out; 492 if (np->local_ip && np->local_ip != ntohl(iph->daddr)) 493 goto out; 494 if (np->remote_ip && np->remote_ip != ntohl(iph->saddr)) 495 goto out; 496 if (np->local_port && np->local_port != ntohs(uh->dest)) 497 goto out; 498 499 np->rx_hook(np, ntohs(uh->source), 500 (char *)(uh+1), 501 ulen - sizeof(struct udphdr)); 502 503 kfree_skb(skb); 504 return 1; 505 506out: 507 if (atomic_read(&trapped)) { 508 kfree_skb(skb); 509 return 1; 510 } 511 512 return 0; 513} 514 515int netpoll_parse_options(struct netpoll *np, char *opt) 516{ 517 char *cur=opt, *delim; 518 519 if (*cur != '@') { 520 if ((delim = strchr(cur, '@')) == NULL) 521 goto parse_failed; 522 *delim = 0; 523 np->local_port = simple_strtol(cur, NULL, 10); 524 cur = delim; 525 } 526 cur++; 527 printk(KERN_INFO "%s: local port %d\n", np->name, np->local_port); 528 529 if (*cur != '/') { 530 if ((delim = strchr(cur, '/')) == NULL) 531 goto parse_failed; 532 *delim = 0; 533 np->local_ip = ntohl(in_aton(cur)); 534 cur = delim; 535 536 printk(KERN_INFO "%s: local IP %d.%d.%d.%d\n", 537 np->name, HIPQUAD(np->local_ip)); 538 } 539 cur++; 540 541 if (*cur != ',') { 542 /* parse out dev name */ 543 if ((delim = strchr(cur, ',')) == NULL) 544 goto parse_failed; 545 *delim = 0; 546 strlcpy(np->dev_name, cur, sizeof(np->dev_name)); 547 cur = delim; 548 } 549 cur++; 550 551 printk(KERN_INFO "%s: interface %s\n", np->name, np->dev_name); 552 553 if (*cur != '@') { 554 /* dst port */ 555 if ((delim = strchr(cur, '@')) == NULL) 556 goto parse_failed; 557 *delim = 0; 558 np->remote_port = simple_strtol(cur, NULL, 10); 559 cur = delim; 560 } 561 cur++; 562 printk(KERN_INFO "%s: remote port %d\n", np->name, np->remote_port); 563 564 /* dst ip */ 565 if ((delim = strchr(cur, '/')) == NULL) 566 goto parse_failed; 567 *delim = 0; 568 np->remote_ip = ntohl(in_aton(cur)); 569 cur = delim + 1; 570 571 printk(KERN_INFO "%s: remote IP %d.%d.%d.%d\n", 572 np->name, HIPQUAD(np->remote_ip)); 573 574 if (*cur != 0) { 575 /* MAC address */ 576 if ((delim = strchr(cur, ':')) == NULL) 577 goto parse_failed; 578 *delim = 0; 579 np->remote_mac[0] = simple_strtol(cur, NULL, 16); 580 cur = delim + 1; 581 if ((delim = strchr(cur, ':')) == NULL) 582 goto parse_failed; 583 *delim = 0; 584 np->remote_mac[1] = 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[2] = 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[3] = 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[4] = simple_strtol(cur, NULL, 16); 600 cur = delim + 1; 601 np->remote_mac[5] = simple_strtol(cur, NULL, 16); 602 } 603 604 printk(KERN_INFO "%s: remote ethernet address " 605 "%02x:%02x:%02x:%02x:%02x:%02x\n", 606 np->name, 607 np->remote_mac[0], 608 np->remote_mac[1], 609 np->remote_mac[2], 610 np->remote_mac[3], 611 np->remote_mac[4], 612 np->remote_mac[5]); 613 614 return 0; 615 616 parse_failed: 617 printk(KERN_INFO "%s: couldn't parse config at %s!\n", 618 np->name, cur); 619 return -1; 620} 621 622int netpoll_setup(struct netpoll *np) 623{ 624 struct net_device *ndev = NULL; 625 struct in_device *in_dev; 626 struct netpoll_info *npinfo; 627 unsigned long flags; 628 int err; 629 630 if (np->dev_name) 631 ndev = dev_get_by_name(np->dev_name); 632 if (!ndev) { 633 printk(KERN_ERR "%s: %s doesn't exist, aborting.\n", 634 np->name, np->dev_name); 635 return -ENODEV; 636 } 637 638 np->dev = ndev; 639 if (!ndev->npinfo) { 640 npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL); 641 if (!npinfo) { 642 err = -ENOMEM; 643 goto release; 644 } 645 646 npinfo->rx_flags = 0; 647 npinfo->rx_np = NULL; 648 spin_lock_init(&npinfo->poll_lock); 649 npinfo->poll_owner = -1; 650 651 spin_lock_init(&npinfo->rx_lock); 652 skb_queue_head_init(&npinfo->arp_tx); 653 skb_queue_head_init(&npinfo->txq); 654 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process); 655 656 atomic_set(&npinfo->refcnt, 1); 657 } else { 658 npinfo = ndev->npinfo; 659 atomic_inc(&npinfo->refcnt); 660 } 661 662 if (!ndev->poll_controller) { 663 printk(KERN_ERR "%s: %s doesn't support polling, aborting.\n", 664 np->name, np->dev_name); 665 err = -ENOTSUPP; 666 goto release; 667 } 668 669 if (!netif_running(ndev)) { 670 unsigned long atmost, atleast; 671 672 printk(KERN_INFO "%s: device %s not up yet, forcing it\n", 673 np->name, np->dev_name); 674 675 rtnl_lock(); 676 err = dev_open(ndev); 677 rtnl_unlock(); 678 679 if (err) { 680 printk(KERN_ERR "%s: failed to open %s\n", 681 np->name, ndev->name); 682 goto release; 683 } 684 685 atleast = jiffies + HZ/10; 686 atmost = jiffies + 4*HZ; 687 while (!netif_carrier_ok(ndev)) { 688 if (time_after(jiffies, atmost)) { 689 printk(KERN_NOTICE 690 "%s: timeout waiting for carrier\n", 691 np->name); 692 break; 693 } 694 cond_resched(); 695 } 696 697 /* If carrier appears to come up instantly, we don't 698 * trust it and pause so that we don't pump all our 699 * queued console messages into the bitbucket. 700 */ 701 702 if (time_before(jiffies, atleast)) { 703 printk(KERN_NOTICE "%s: carrier detect appears" 704 " untrustworthy, waiting 4 seconds\n", 705 np->name); 706 msleep(4000); 707 } 708 } 709 710 if (is_zero_ether_addr(np->local_mac) && ndev->dev_addr) 711 memcpy(np->local_mac, ndev->dev_addr, 6); 712 713 if (!np->local_ip) { 714 rcu_read_lock(); 715 in_dev = __in_dev_get_rcu(ndev); 716 717 if (!in_dev || !in_dev->ifa_list) { 718 rcu_read_unlock(); 719 printk(KERN_ERR "%s: no IP address for %s, aborting\n", 720 np->name, np->dev_name); 721 err = -EDESTADDRREQ; 722 goto release; 723 } 724 725 np->local_ip = ntohl(in_dev->ifa_list->ifa_local); 726 rcu_read_unlock(); 727 printk(KERN_INFO "%s: local IP %d.%d.%d.%d\n", 728 np->name, HIPQUAD(np->local_ip)); 729 } 730 731 if (np->rx_hook) { 732 spin_lock_irqsave(&npinfo->rx_lock, flags); 733 npinfo->rx_flags |= NETPOLL_RX_ENABLED; 734 npinfo->rx_np = np; 735 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 736 } 737 738 /* fill up the skb queue */ 739 refill_skbs(); 740 741 /* last thing to do is link it to the net device structure */ 742 ndev->npinfo = npinfo; 743 744 /* avoid racing with NAPI reading npinfo */ 745 synchronize_rcu(); 746 747 return 0; 748 749 release: 750 if (!ndev->npinfo) 751 kfree(npinfo); 752 np->dev = NULL; 753 dev_put(ndev); 754 return err; 755} 756 757static int __init netpoll_init(void) 758{ 759 skb_queue_head_init(&skb_pool); 760 return 0; 761} 762core_initcall(netpoll_init); 763 764void netpoll_cleanup(struct netpoll *np) 765{ 766 struct netpoll_info *npinfo; 767 unsigned long flags; 768 769 if (np->dev) { 770 npinfo = np->dev->npinfo; 771 if (npinfo) { 772 if (npinfo->rx_np == np) { 773 spin_lock_irqsave(&npinfo->rx_lock, flags); 774 npinfo->rx_np = NULL; 775 npinfo->rx_flags &= ~NETPOLL_RX_ENABLED; 776 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 777 } 778 779 np->dev->npinfo = NULL; 780 if (atomic_dec_and_test(&npinfo->refcnt)) { 781 skb_queue_purge(&npinfo->arp_tx); 782 skb_queue_purge(&npinfo->txq); 783 cancel_rearming_delayed_work(&npinfo->tx_work); 784 flush_scheduled_work(); 785 786 kfree(npinfo); 787 } 788 } 789 790 dev_put(np->dev); 791 } 792 793 np->dev = NULL; 794} 795 796int netpoll_trap(void) 797{ 798 return atomic_read(&trapped); 799} 800 801void netpoll_set_trap(int trap) 802{ 803 if (trap) 804 atomic_inc(&trapped); 805 else 806 atomic_dec(&trapped); 807} 808 809EXPORT_SYMBOL(netpoll_set_trap); 810EXPORT_SYMBOL(netpoll_trap); 811EXPORT_SYMBOL(netpoll_parse_options); 812EXPORT_SYMBOL(netpoll_setup); 813EXPORT_SYMBOL(netpoll_cleanup); 814EXPORT_SYMBOL(netpoll_send_udp); 815EXPORT_SYMBOL(netpoll_poll); 816