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 38 static struct sk_buff_head skb_pool; 39 40 static 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 50 static void zap_completion_queue(void); 51 static void arp_reply(struct sk_buff *skb); 52 53 static 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 84 static __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 */ 119 static 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 } 137 138 static 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 } 152 153 void 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 } 167 168 static 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 } 183 184 static 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 } 209 210 static 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(); 217 repeat: 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 } 235 236 static 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 } 279 280 void 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 } 336 337 static 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 } 431 432 int __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 == __constant_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 if (iph->protocol != IPPROTO_UDP) 475 goto out; 476 477 len -= iph->ihl*4; 478 uh = (struct udphdr *)(((char *)iph) + iph->ihl*4); 479 ulen = ntohs(uh->len); 480 481 if (ulen != len) 482 goto out; 483 if (checksum_udp(skb, uh, ulen, iph->saddr, iph->daddr)) 484 goto out; 485 if (np->local_ip && np->local_ip != ntohl(iph->daddr)) 486 goto out; 487 if (np->remote_ip && np->remote_ip != ntohl(iph->saddr)) 488 goto out; 489 if (np->local_port && np->local_port != ntohs(uh->dest)) 490 goto out; 491 492 np->rx_hook(np, ntohs(uh->source), 493 (char *)(uh+1), 494 ulen - sizeof(struct udphdr)); 495 496 kfree_skb(skb); 497 return 1; 498 499 out: 500 if (atomic_read(&trapped)) { 501 kfree_skb(skb); 502 return 1; 503 } 504 505 return 0; 506 } 507 508 int netpoll_parse_options(struct netpoll *np, char *opt) 509 { 510 char *cur=opt, *delim; 511 512 if (*cur != '@') { 513 if ((delim = strchr(cur, '@')) == NULL) 514 goto parse_failed; 515 *delim = 0; 516 np->local_port = simple_strtol(cur, NULL, 10); 517 cur = delim; 518 } 519 cur++; 520 printk(KERN_INFO "%s: local port %d\n", np->name, np->local_port); 521 522 if (*cur != '/') { 523 if ((delim = strchr(cur, '/')) == NULL) 524 goto parse_failed; 525 *delim = 0; 526 np->local_ip = ntohl(in_aton(cur)); 527 cur = delim; 528 529 printk(KERN_INFO "%s: local IP %d.%d.%d.%d\n", 530 np->name, HIPQUAD(np->local_ip)); 531 } 532 cur++; 533 534 if (*cur != ',') { 535 /* parse out dev name */ 536 if ((delim = strchr(cur, ',')) == NULL) 537 goto parse_failed; 538 *delim = 0; 539 strlcpy(np->dev_name, cur, sizeof(np->dev_name)); 540 cur = delim; 541 } 542 cur++; 543 544 printk(KERN_INFO "%s: interface %s\n", np->name, np->dev_name); 545 546 if (*cur != '@') { 547 /* dst port */ 548 if ((delim = strchr(cur, '@')) == NULL) 549 goto parse_failed; 550 *delim = 0; 551 np->remote_port = simple_strtol(cur, NULL, 10); 552 cur = delim; 553 } 554 cur++; 555 printk(KERN_INFO "%s: remote port %d\n", np->name, np->remote_port); 556 557 /* dst ip */ 558 if ((delim = strchr(cur, '/')) == NULL) 559 goto parse_failed; 560 *delim = 0; 561 np->remote_ip = ntohl(in_aton(cur)); 562 cur = delim + 1; 563 564 printk(KERN_INFO "%s: remote IP %d.%d.%d.%d\n", 565 np->name, HIPQUAD(np->remote_ip)); 566 567 if (*cur != 0) { 568 /* MAC address */ 569 if ((delim = strchr(cur, ':')) == NULL) 570 goto parse_failed; 571 *delim = 0; 572 np->remote_mac[0] = simple_strtol(cur, NULL, 16); 573 cur = delim + 1; 574 if ((delim = strchr(cur, ':')) == NULL) 575 goto parse_failed; 576 *delim = 0; 577 np->remote_mac[1] = simple_strtol(cur, NULL, 16); 578 cur = delim + 1; 579 if ((delim = strchr(cur, ':')) == NULL) 580 goto parse_failed; 581 *delim = 0; 582 np->remote_mac[2] = 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[3] = 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[4] = simple_strtol(cur, NULL, 16); 593 cur = delim + 1; 594 np->remote_mac[5] = simple_strtol(cur, NULL, 16); 595 } 596 597 printk(KERN_INFO "%s: remote ethernet address " 598 "%02x:%02x:%02x:%02x:%02x:%02x\n", 599 np->name, 600 np->remote_mac[0], 601 np->remote_mac[1], 602 np->remote_mac[2], 603 np->remote_mac[3], 604 np->remote_mac[4], 605 np->remote_mac[5]); 606 607 return 0; 608 609 parse_failed: 610 printk(KERN_INFO "%s: couldn't parse config at %s!\n", 611 np->name, cur); 612 return -1; 613 } 614 615 int netpoll_setup(struct netpoll *np) 616 { 617 struct net_device *ndev = NULL; 618 struct in_device *in_dev; 619 struct netpoll_info *npinfo; 620 unsigned long flags; 621 int err; 622 623 if (np->dev_name) 624 ndev = dev_get_by_name(np->dev_name); 625 if (!ndev) { 626 printk(KERN_ERR "%s: %s doesn't exist, aborting.\n", 627 np->name, np->dev_name); 628 return -ENODEV; 629 } 630 631 np->dev = ndev; 632 if (!ndev->npinfo) { 633 npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL); 634 if (!npinfo) { 635 err = -ENOMEM; 636 goto release; 637 } 638 639 npinfo->rx_flags = 0; 640 npinfo->rx_np = NULL; 641 spin_lock_init(&npinfo->poll_lock); 642 npinfo->poll_owner = -1; 643 644 spin_lock_init(&npinfo->rx_lock); 645 skb_queue_head_init(&npinfo->arp_tx); 646 skb_queue_head_init(&npinfo->txq); 647 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process); 648 649 atomic_set(&npinfo->refcnt, 1); 650 } else { 651 npinfo = ndev->npinfo; 652 atomic_inc(&npinfo->refcnt); 653 } 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 err = -ENOTSUPP; 659 goto release; 660 } 661 662 if (!netif_running(ndev)) { 663 unsigned long atmost, atleast; 664 665 printk(KERN_INFO "%s: device %s not up yet, forcing it\n", 666 np->name, np->dev_name); 667 668 rtnl_lock(); 669 err = dev_open(ndev); 670 rtnl_unlock(); 671 672 if (err) { 673 printk(KERN_ERR "%s: failed to open %s\n", 674 np->name, ndev->name); 675 goto release; 676 } 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 err = -EDESTADDRREQ; 715 goto release; 716 } 717 718 np->local_ip = ntohl(in_dev->ifa_list->ifa_local); 719 rcu_read_unlock(); 720 printk(KERN_INFO "%s: local IP %d.%d.%d.%d\n", 721 np->name, HIPQUAD(np->local_ip)); 722 } 723 724 if (np->rx_hook) { 725 spin_lock_irqsave(&npinfo->rx_lock, flags); 726 npinfo->rx_flags |= NETPOLL_RX_ENABLED; 727 npinfo->rx_np = np; 728 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 729 } 730 731 /* fill up the skb queue */ 732 refill_skbs(); 733 734 /* last thing to do is link it to the net device structure */ 735 ndev->npinfo = npinfo; 736 737 /* avoid racing with NAPI reading npinfo */ 738 synchronize_rcu(); 739 740 return 0; 741 742 release: 743 if (!ndev->npinfo) 744 kfree(npinfo); 745 np->dev = NULL; 746 dev_put(ndev); 747 return err; 748 } 749 750 static int __init netpoll_init(void) 751 { 752 skb_queue_head_init(&skb_pool); 753 return 0; 754 } 755 core_initcall(netpoll_init); 756 757 void netpoll_cleanup(struct netpoll *np) 758 { 759 struct netpoll_info *npinfo; 760 unsigned long flags; 761 762 if (np->dev) { 763 npinfo = np->dev->npinfo; 764 if (npinfo) { 765 if (npinfo->rx_np == np) { 766 spin_lock_irqsave(&npinfo->rx_lock, flags); 767 npinfo->rx_np = NULL; 768 npinfo->rx_flags &= ~NETPOLL_RX_ENABLED; 769 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 770 } 771 772 np->dev->npinfo = NULL; 773 if (atomic_dec_and_test(&npinfo->refcnt)) { 774 skb_queue_purge(&npinfo->arp_tx); 775 skb_queue_purge(&npinfo->txq); 776 cancel_rearming_delayed_work(&npinfo->tx_work); 777 flush_scheduled_work(); 778 779 kfree(npinfo); 780 } 781 } 782 783 dev_put(np->dev); 784 } 785 786 np->dev = NULL; 787 } 788 789 int netpoll_trap(void) 790 { 791 return atomic_read(&trapped); 792 } 793 794 void netpoll_set_trap(int trap) 795 { 796 if (trap) 797 atomic_inc(&trapped); 798 else 799 atomic_dec(&trapped); 800 } 801 802 EXPORT_SYMBOL(netpoll_set_trap); 803 EXPORT_SYMBOL(netpoll_trap); 804 EXPORT_SYMBOL(netpoll_parse_options); 805 EXPORT_SYMBOL(netpoll_setup); 806 EXPORT_SYMBOL(netpoll_cleanup); 807 EXPORT_SYMBOL(netpoll_send_udp); 808 EXPORT_SYMBOL(netpoll_poll); 809