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/netdevice.h> 13 #include <linux/etherdevice.h> 14 #include <linux/string.h> 15 #include <linux/if_arp.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 37 static struct sk_buff_head skb_pool; 38 39 static atomic_t trapped; 40 41 #define USEC_PER_POLL 50 42 #define NETPOLL_RX_ENABLED 1 43 #define NETPOLL_RX_DROP 2 44 45 #define MAX_SKB_SIZE \ 46 (MAX_UDP_CHUNK + sizeof(struct udphdr) + \ 47 sizeof(struct iphdr) + sizeof(struct ethhdr)) 48 49 static void zap_completion_queue(void); 50 static void arp_reply(struct sk_buff *skb); 51 52 static void queue_process(struct work_struct *work) 53 { 54 struct netpoll_info *npinfo = 55 container_of(work, struct netpoll_info, tx_work.work); 56 struct sk_buff *skb; 57 unsigned long flags; 58 59 while ((skb = skb_dequeue(&npinfo->txq))) { 60 struct net_device *dev = skb->dev; 61 const struct net_device_ops *ops = dev->netdev_ops; 62 struct netdev_queue *txq; 63 64 if (!netif_device_present(dev) || !netif_running(dev)) { 65 __kfree_skb(skb); 66 continue; 67 } 68 69 txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb)); 70 71 local_irq_save(flags); 72 __netif_tx_lock(txq, smp_processor_id()); 73 if (netif_tx_queue_stopped(txq) || 74 netif_tx_queue_frozen(txq) || 75 ops->ndo_start_xmit(skb, dev) != NETDEV_TX_OK) { 76 skb_queue_head(&npinfo->txq, skb); 77 __netif_tx_unlock(txq); 78 local_irq_restore(flags); 79 80 schedule_delayed_work(&npinfo->tx_work, HZ/10); 81 return; 82 } 83 __netif_tx_unlock(txq); 84 local_irq_restore(flags); 85 } 86 } 87 88 static __sum16 checksum_udp(struct sk_buff *skb, struct udphdr *uh, 89 unsigned short ulen, __be32 saddr, __be32 daddr) 90 { 91 __wsum psum; 92 93 if (uh->check == 0 || skb_csum_unnecessary(skb)) 94 return 0; 95 96 psum = csum_tcpudp_nofold(saddr, daddr, ulen, IPPROTO_UDP, 0); 97 98 if (skb->ip_summed == CHECKSUM_COMPLETE && 99 !csum_fold(csum_add(psum, skb->csum))) 100 return 0; 101 102 skb->csum = psum; 103 104 return __skb_checksum_complete(skb); 105 } 106 107 /* 108 * Check whether delayed processing was scheduled for our NIC. If so, 109 * we attempt to grab the poll lock and use ->poll() to pump the card. 110 * If this fails, either we've recursed in ->poll() or it's already 111 * running on another CPU. 112 * 113 * Note: we don't mask interrupts with this lock because we're using 114 * trylock here and interrupts are already disabled in the softirq 115 * case. Further, we test the poll_owner to avoid recursion on UP 116 * systems where the lock doesn't exist. 117 * 118 * In cases where there is bi-directional communications, reading only 119 * one message at a time can lead to packets being dropped by the 120 * network adapter, forcing superfluous retries and possibly timeouts. 121 * Thus, we set our budget to greater than 1. 122 */ 123 static int poll_one_napi(struct netpoll_info *npinfo, 124 struct napi_struct *napi, int budget) 125 { 126 int work; 127 128 /* net_rx_action's ->poll() invocations and our's are 129 * synchronized by this test which is only made while 130 * holding the napi->poll_lock. 131 */ 132 if (!test_bit(NAPI_STATE_SCHED, &napi->state)) 133 return budget; 134 135 npinfo->rx_flags |= NETPOLL_RX_DROP; 136 atomic_inc(&trapped); 137 set_bit(NAPI_STATE_NPSVC, &napi->state); 138 139 work = napi->poll(napi, budget); 140 141 clear_bit(NAPI_STATE_NPSVC, &napi->state); 142 atomic_dec(&trapped); 143 npinfo->rx_flags &= ~NETPOLL_RX_DROP; 144 145 return budget - work; 146 } 147 148 static void poll_napi(struct net_device *dev) 149 { 150 struct napi_struct *napi; 151 int budget = 16; 152 153 list_for_each_entry(napi, &dev->napi_list, dev_list) { 154 if (napi->poll_owner != smp_processor_id() && 155 spin_trylock(&napi->poll_lock)) { 156 budget = poll_one_napi(dev->npinfo, napi, budget); 157 spin_unlock(&napi->poll_lock); 158 159 if (!budget) 160 break; 161 } 162 } 163 } 164 165 static void service_arp_queue(struct netpoll_info *npi) 166 { 167 if (npi) { 168 struct sk_buff *skb; 169 170 while ((skb = skb_dequeue(&npi->arp_tx))) 171 arp_reply(skb); 172 } 173 } 174 175 void netpoll_poll(struct netpoll *np) 176 { 177 struct net_device *dev = np->dev; 178 const struct net_device_ops *ops; 179 180 if (!dev || !netif_running(dev)) 181 return; 182 183 ops = dev->netdev_ops; 184 if (!ops->ndo_poll_controller) 185 return; 186 187 /* Process pending work on NIC */ 188 ops->ndo_poll_controller(dev); 189 190 poll_napi(dev); 191 192 service_arp_queue(dev->npinfo); 193 194 zap_completion_queue(); 195 } 196 197 static void refill_skbs(void) 198 { 199 struct sk_buff *skb; 200 unsigned long flags; 201 202 spin_lock_irqsave(&skb_pool.lock, flags); 203 while (skb_pool.qlen < MAX_SKBS) { 204 skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC); 205 if (!skb) 206 break; 207 208 __skb_queue_tail(&skb_pool, skb); 209 } 210 spin_unlock_irqrestore(&skb_pool.lock, flags); 211 } 212 213 static void zap_completion_queue(void) 214 { 215 unsigned long flags; 216 struct softnet_data *sd = &get_cpu_var(softnet_data); 217 218 if (sd->completion_queue) { 219 struct sk_buff *clist; 220 221 local_irq_save(flags); 222 clist = sd->completion_queue; 223 sd->completion_queue = NULL; 224 local_irq_restore(flags); 225 226 while (clist != NULL) { 227 struct sk_buff *skb = clist; 228 clist = clist->next; 229 if (skb->destructor) { 230 atomic_inc(&skb->users); 231 dev_kfree_skb_any(skb); /* put this one back */ 232 } else { 233 __kfree_skb(skb); 234 } 235 } 236 } 237 238 put_cpu_var(softnet_data); 239 } 240 241 static struct sk_buff *find_skb(struct netpoll *np, int len, int reserve) 242 { 243 int count = 0; 244 struct sk_buff *skb; 245 246 zap_completion_queue(); 247 refill_skbs(); 248 repeat: 249 250 skb = alloc_skb(len, GFP_ATOMIC); 251 if (!skb) 252 skb = skb_dequeue(&skb_pool); 253 254 if (!skb) { 255 if (++count < 10) { 256 netpoll_poll(np); 257 goto repeat; 258 } 259 return NULL; 260 } 261 262 atomic_set(&skb->users, 1); 263 skb_reserve(skb, reserve); 264 return skb; 265 } 266 267 static int netpoll_owner_active(struct net_device *dev) 268 { 269 struct napi_struct *napi; 270 271 list_for_each_entry(napi, &dev->napi_list, dev_list) { 272 if (napi->poll_owner == smp_processor_id()) 273 return 1; 274 } 275 return 0; 276 } 277 278 static void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb) 279 { 280 int status = NETDEV_TX_BUSY; 281 unsigned long tries; 282 struct net_device *dev = np->dev; 283 const struct net_device_ops *ops = dev->netdev_ops; 284 struct netpoll_info *npinfo = np->dev->npinfo; 285 286 if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) { 287 __kfree_skb(skb); 288 return; 289 } 290 291 /* don't get messages out of order, and no recursion */ 292 if (skb_queue_len(&npinfo->txq) == 0 && !netpoll_owner_active(dev)) { 293 struct netdev_queue *txq; 294 unsigned long flags; 295 296 txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb)); 297 298 local_irq_save(flags); 299 /* try until next clock tick */ 300 for (tries = jiffies_to_usecs(1)/USEC_PER_POLL; 301 tries > 0; --tries) { 302 if (__netif_tx_trylock(txq)) { 303 if (!netif_tx_queue_stopped(txq)) 304 status = ops->ndo_start_xmit(skb, dev); 305 __netif_tx_unlock(txq); 306 307 if (status == NETDEV_TX_OK) 308 break; 309 310 } 311 312 /* tickle device maybe there is some cleanup */ 313 netpoll_poll(np); 314 315 udelay(USEC_PER_POLL); 316 } 317 local_irq_restore(flags); 318 } 319 320 if (status != NETDEV_TX_OK) { 321 skb_queue_tail(&npinfo->txq, skb); 322 schedule_delayed_work(&npinfo->tx_work,0); 323 } 324 } 325 326 void netpoll_send_udp(struct netpoll *np, const char *msg, int len) 327 { 328 int total_len, eth_len, ip_len, udp_len; 329 struct sk_buff *skb; 330 struct udphdr *udph; 331 struct iphdr *iph; 332 struct ethhdr *eth; 333 334 udp_len = len + sizeof(*udph); 335 ip_len = eth_len = udp_len + sizeof(*iph); 336 total_len = eth_len + ETH_HLEN + NET_IP_ALIGN; 337 338 skb = find_skb(np, total_len, total_len - len); 339 if (!skb) 340 return; 341 342 skb_copy_to_linear_data(skb, msg, len); 343 skb->len += len; 344 345 skb_push(skb, sizeof(*udph)); 346 skb_reset_transport_header(skb); 347 udph = udp_hdr(skb); 348 udph->source = htons(np->local_port); 349 udph->dest = htons(np->remote_port); 350 udph->len = htons(udp_len); 351 udph->check = 0; 352 udph->check = csum_tcpudp_magic(np->local_ip, 353 np->remote_ip, 354 udp_len, IPPROTO_UDP, 355 csum_partial(udph, udp_len, 0)); 356 if (udph->check == 0) 357 udph->check = CSUM_MANGLED_0; 358 359 skb_push(skb, sizeof(*iph)); 360 skb_reset_network_header(skb); 361 iph = ip_hdr(skb); 362 363 /* iph->version = 4; iph->ihl = 5; */ 364 put_unaligned(0x45, (unsigned char *)iph); 365 iph->tos = 0; 366 put_unaligned(htons(ip_len), &(iph->tot_len)); 367 iph->id = 0; 368 iph->frag_off = 0; 369 iph->ttl = 64; 370 iph->protocol = IPPROTO_UDP; 371 iph->check = 0; 372 put_unaligned(np->local_ip, &(iph->saddr)); 373 put_unaligned(np->remote_ip, &(iph->daddr)); 374 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); 375 376 eth = (struct ethhdr *) skb_push(skb, ETH_HLEN); 377 skb_reset_mac_header(skb); 378 skb->protocol = eth->h_proto = htons(ETH_P_IP); 379 memcpy(eth->h_source, np->dev->dev_addr, ETH_ALEN); 380 memcpy(eth->h_dest, np->remote_mac, ETH_ALEN); 381 382 skb->dev = np->dev; 383 384 netpoll_send_skb(np, skb); 385 } 386 387 static void arp_reply(struct sk_buff *skb) 388 { 389 struct netpoll_info *npinfo = skb->dev->npinfo; 390 struct arphdr *arp; 391 unsigned char *arp_ptr; 392 int size, type = ARPOP_REPLY, ptype = ETH_P_ARP; 393 __be32 sip, tip; 394 unsigned char *sha; 395 struct sk_buff *send_skb; 396 struct netpoll *np = NULL; 397 398 if (npinfo->rx_np && npinfo->rx_np->dev == skb->dev) 399 np = npinfo->rx_np; 400 if (!np) 401 return; 402 403 /* No arp on this interface */ 404 if (skb->dev->flags & IFF_NOARP) 405 return; 406 407 if (!pskb_may_pull(skb, arp_hdr_len(skb->dev))) 408 return; 409 410 skb_reset_network_header(skb); 411 skb_reset_transport_header(skb); 412 arp = arp_hdr(skb); 413 414 if ((arp->ar_hrd != htons(ARPHRD_ETHER) && 415 arp->ar_hrd != htons(ARPHRD_IEEE802)) || 416 arp->ar_pro != htons(ETH_P_IP) || 417 arp->ar_op != htons(ARPOP_REQUEST)) 418 return; 419 420 arp_ptr = (unsigned char *)(arp+1); 421 /* save the location of the src hw addr */ 422 sha = arp_ptr; 423 arp_ptr += skb->dev->addr_len; 424 memcpy(&sip, arp_ptr, 4); 425 arp_ptr += 4; 426 /* if we actually cared about dst hw addr, it would get copied here */ 427 arp_ptr += skb->dev->addr_len; 428 memcpy(&tip, arp_ptr, 4); 429 430 /* Should we ignore arp? */ 431 if (tip != np->local_ip || 432 ipv4_is_loopback(tip) || ipv4_is_multicast(tip)) 433 return; 434 435 size = arp_hdr_len(skb->dev); 436 send_skb = find_skb(np, size + LL_ALLOCATED_SPACE(np->dev), 437 LL_RESERVED_SPACE(np->dev)); 438 439 if (!send_skb) 440 return; 441 442 skb_reset_network_header(send_skb); 443 arp = (struct arphdr *) skb_put(send_skb, size); 444 send_skb->dev = skb->dev; 445 send_skb->protocol = htons(ETH_P_ARP); 446 447 /* Fill the device header for the ARP frame */ 448 if (dev_hard_header(send_skb, skb->dev, ptype, 449 sha, np->dev->dev_addr, 450 send_skb->len) < 0) { 451 kfree_skb(send_skb); 452 return; 453 } 454 455 /* 456 * Fill out the arp protocol part. 457 * 458 * we only support ethernet device type, 459 * which (according to RFC 1390) should always equal 1 (Ethernet). 460 */ 461 462 arp->ar_hrd = htons(np->dev->type); 463 arp->ar_pro = htons(ETH_P_IP); 464 arp->ar_hln = np->dev->addr_len; 465 arp->ar_pln = 4; 466 arp->ar_op = htons(type); 467 468 arp_ptr=(unsigned char *)(arp + 1); 469 memcpy(arp_ptr, np->dev->dev_addr, np->dev->addr_len); 470 arp_ptr += np->dev->addr_len; 471 memcpy(arp_ptr, &tip, 4); 472 arp_ptr += 4; 473 memcpy(arp_ptr, sha, np->dev->addr_len); 474 arp_ptr += np->dev->addr_len; 475 memcpy(arp_ptr, &sip, 4); 476 477 netpoll_send_skb(np, send_skb); 478 } 479 480 int __netpoll_rx(struct sk_buff *skb) 481 { 482 int proto, len, ulen; 483 struct iphdr *iph; 484 struct udphdr *uh; 485 struct netpoll_info *npi = skb->dev->npinfo; 486 struct netpoll *np = npi->rx_np; 487 488 if (!np) 489 goto out; 490 if (skb->dev->type != ARPHRD_ETHER) 491 goto out; 492 493 /* check if netpoll clients need ARP */ 494 if (skb->protocol == htons(ETH_P_ARP) && 495 atomic_read(&trapped)) { 496 skb_queue_tail(&npi->arp_tx, skb); 497 return 1; 498 } 499 500 proto = ntohs(eth_hdr(skb)->h_proto); 501 if (proto != ETH_P_IP) 502 goto out; 503 if (skb->pkt_type == PACKET_OTHERHOST) 504 goto out; 505 if (skb_shared(skb)) 506 goto out; 507 508 iph = (struct iphdr *)skb->data; 509 if (!pskb_may_pull(skb, sizeof(struct iphdr))) 510 goto out; 511 if (iph->ihl < 5 || iph->version != 4) 512 goto out; 513 if (!pskb_may_pull(skb, iph->ihl*4)) 514 goto out; 515 if (ip_fast_csum((u8 *)iph, iph->ihl) != 0) 516 goto out; 517 518 len = ntohs(iph->tot_len); 519 if (skb->len < len || len < iph->ihl*4) 520 goto out; 521 522 /* 523 * Our transport medium may have padded the buffer out. 524 * Now We trim to the true length of the frame. 525 */ 526 if (pskb_trim_rcsum(skb, len)) 527 goto out; 528 529 if (iph->protocol != IPPROTO_UDP) 530 goto out; 531 532 len -= iph->ihl*4; 533 uh = (struct udphdr *)(((char *)iph) + iph->ihl*4); 534 ulen = ntohs(uh->len); 535 536 if (ulen != len) 537 goto out; 538 if (checksum_udp(skb, uh, ulen, iph->saddr, iph->daddr)) 539 goto out; 540 if (np->local_ip && np->local_ip != iph->daddr) 541 goto out; 542 if (np->remote_ip && np->remote_ip != iph->saddr) 543 goto out; 544 if (np->local_port && np->local_port != ntohs(uh->dest)) 545 goto out; 546 547 np->rx_hook(np, ntohs(uh->source), 548 (char *)(uh+1), 549 ulen - sizeof(struct udphdr)); 550 551 kfree_skb(skb); 552 return 1; 553 554 out: 555 if (atomic_read(&trapped)) { 556 kfree_skb(skb); 557 return 1; 558 } 559 560 return 0; 561 } 562 563 void netpoll_print_options(struct netpoll *np) 564 { 565 printk(KERN_INFO "%s: local port %d\n", 566 np->name, np->local_port); 567 printk(KERN_INFO "%s: local IP %pI4\n", 568 np->name, &np->local_ip); 569 printk(KERN_INFO "%s: interface %s\n", 570 np->name, np->dev_name); 571 printk(KERN_INFO "%s: remote port %d\n", 572 np->name, np->remote_port); 573 printk(KERN_INFO "%s: remote IP %pI4\n", 574 np->name, &np->remote_ip); 575 printk(KERN_INFO "%s: remote ethernet address %pM\n", 576 np->name, np->remote_mac); 577 } 578 579 int netpoll_parse_options(struct netpoll *np, char *opt) 580 { 581 char *cur=opt, *delim; 582 583 if (*cur != '@') { 584 if ((delim = strchr(cur, '@')) == NULL) 585 goto parse_failed; 586 *delim = 0; 587 np->local_port = simple_strtol(cur, NULL, 10); 588 cur = delim; 589 } 590 cur++; 591 592 if (*cur != '/') { 593 if ((delim = strchr(cur, '/')) == NULL) 594 goto parse_failed; 595 *delim = 0; 596 np->local_ip = in_aton(cur); 597 cur = delim; 598 } 599 cur++; 600 601 if (*cur != ',') { 602 /* parse out dev name */ 603 if ((delim = strchr(cur, ',')) == NULL) 604 goto parse_failed; 605 *delim = 0; 606 strlcpy(np->dev_name, cur, sizeof(np->dev_name)); 607 cur = delim; 608 } 609 cur++; 610 611 if (*cur != '@') { 612 /* dst port */ 613 if ((delim = strchr(cur, '@')) == NULL) 614 goto parse_failed; 615 *delim = 0; 616 np->remote_port = simple_strtol(cur, NULL, 10); 617 cur = delim; 618 } 619 cur++; 620 621 /* dst ip */ 622 if ((delim = strchr(cur, '/')) == NULL) 623 goto parse_failed; 624 *delim = 0; 625 np->remote_ip = in_aton(cur); 626 cur = delim + 1; 627 628 if (*cur != 0) { 629 /* MAC address */ 630 if ((delim = strchr(cur, ':')) == NULL) 631 goto parse_failed; 632 *delim = 0; 633 np->remote_mac[0] = simple_strtol(cur, NULL, 16); 634 cur = delim + 1; 635 if ((delim = strchr(cur, ':')) == NULL) 636 goto parse_failed; 637 *delim = 0; 638 np->remote_mac[1] = simple_strtol(cur, NULL, 16); 639 cur = delim + 1; 640 if ((delim = strchr(cur, ':')) == NULL) 641 goto parse_failed; 642 *delim = 0; 643 np->remote_mac[2] = simple_strtol(cur, NULL, 16); 644 cur = delim + 1; 645 if ((delim = strchr(cur, ':')) == NULL) 646 goto parse_failed; 647 *delim = 0; 648 np->remote_mac[3] = simple_strtol(cur, NULL, 16); 649 cur = delim + 1; 650 if ((delim = strchr(cur, ':')) == NULL) 651 goto parse_failed; 652 *delim = 0; 653 np->remote_mac[4] = simple_strtol(cur, NULL, 16); 654 cur = delim + 1; 655 np->remote_mac[5] = simple_strtol(cur, NULL, 16); 656 } 657 658 netpoll_print_options(np); 659 660 return 0; 661 662 parse_failed: 663 printk(KERN_INFO "%s: couldn't parse config at %s!\n", 664 np->name, cur); 665 return -1; 666 } 667 668 int netpoll_setup(struct netpoll *np) 669 { 670 struct net_device *ndev = NULL; 671 struct in_device *in_dev; 672 struct netpoll_info *npinfo; 673 unsigned long flags; 674 int err; 675 676 if (np->dev_name) 677 ndev = dev_get_by_name(&init_net, np->dev_name); 678 if (!ndev) { 679 printk(KERN_ERR "%s: %s doesn't exist, aborting.\n", 680 np->name, np->dev_name); 681 return -ENODEV; 682 } 683 684 np->dev = ndev; 685 if (!ndev->npinfo) { 686 npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL); 687 if (!npinfo) { 688 err = -ENOMEM; 689 goto release; 690 } 691 692 npinfo->rx_flags = 0; 693 npinfo->rx_np = NULL; 694 695 spin_lock_init(&npinfo->rx_lock); 696 skb_queue_head_init(&npinfo->arp_tx); 697 skb_queue_head_init(&npinfo->txq); 698 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process); 699 700 atomic_set(&npinfo->refcnt, 1); 701 } else { 702 npinfo = ndev->npinfo; 703 atomic_inc(&npinfo->refcnt); 704 } 705 706 if (!ndev->netdev_ops->ndo_poll_controller) { 707 printk(KERN_ERR "%s: %s doesn't support polling, aborting.\n", 708 np->name, np->dev_name); 709 err = -ENOTSUPP; 710 goto release; 711 } 712 713 if (!netif_running(ndev)) { 714 unsigned long atmost, atleast; 715 716 printk(KERN_INFO "%s: device %s not up yet, forcing it\n", 717 np->name, np->dev_name); 718 719 rtnl_lock(); 720 err = dev_open(ndev); 721 rtnl_unlock(); 722 723 if (err) { 724 printk(KERN_ERR "%s: failed to open %s\n", 725 np->name, ndev->name); 726 goto release; 727 } 728 729 atleast = jiffies + HZ/10; 730 atmost = jiffies + 4*HZ; 731 while (!netif_carrier_ok(ndev)) { 732 if (time_after(jiffies, atmost)) { 733 printk(KERN_NOTICE 734 "%s: timeout waiting for carrier\n", 735 np->name); 736 break; 737 } 738 cond_resched(); 739 } 740 741 /* If carrier appears to come up instantly, we don't 742 * trust it and pause so that we don't pump all our 743 * queued console messages into the bitbucket. 744 */ 745 746 if (time_before(jiffies, atleast)) { 747 printk(KERN_NOTICE "%s: carrier detect appears" 748 " untrustworthy, waiting 4 seconds\n", 749 np->name); 750 msleep(4000); 751 } 752 } 753 754 if (!np->local_ip) { 755 rcu_read_lock(); 756 in_dev = __in_dev_get_rcu(ndev); 757 758 if (!in_dev || !in_dev->ifa_list) { 759 rcu_read_unlock(); 760 printk(KERN_ERR "%s: no IP address for %s, aborting\n", 761 np->name, np->dev_name); 762 err = -EDESTADDRREQ; 763 goto release; 764 } 765 766 np->local_ip = in_dev->ifa_list->ifa_local; 767 rcu_read_unlock(); 768 printk(KERN_INFO "%s: local IP %pI4\n", np->name, &np->local_ip); 769 } 770 771 if (np->rx_hook) { 772 spin_lock_irqsave(&npinfo->rx_lock, flags); 773 npinfo->rx_flags |= NETPOLL_RX_ENABLED; 774 npinfo->rx_np = np; 775 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 776 } 777 778 /* fill up the skb queue */ 779 refill_skbs(); 780 781 /* last thing to do is link it to the net device structure */ 782 ndev->npinfo = npinfo; 783 784 /* avoid racing with NAPI reading npinfo */ 785 synchronize_rcu(); 786 787 return 0; 788 789 release: 790 if (!ndev->npinfo) 791 kfree(npinfo); 792 np->dev = NULL; 793 dev_put(ndev); 794 return err; 795 } 796 797 static int __init netpoll_init(void) 798 { 799 skb_queue_head_init(&skb_pool); 800 return 0; 801 } 802 core_initcall(netpoll_init); 803 804 void netpoll_cleanup(struct netpoll *np) 805 { 806 struct netpoll_info *npinfo; 807 unsigned long flags; 808 809 if (np->dev) { 810 npinfo = np->dev->npinfo; 811 if (npinfo) { 812 if (npinfo->rx_np == np) { 813 spin_lock_irqsave(&npinfo->rx_lock, flags); 814 npinfo->rx_np = NULL; 815 npinfo->rx_flags &= ~NETPOLL_RX_ENABLED; 816 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 817 } 818 819 if (atomic_dec_and_test(&npinfo->refcnt)) { 820 skb_queue_purge(&npinfo->arp_tx); 821 skb_queue_purge(&npinfo->txq); 822 cancel_rearming_delayed_work(&npinfo->tx_work); 823 824 /* clean after last, unfinished work */ 825 __skb_queue_purge(&npinfo->txq); 826 kfree(npinfo); 827 np->dev->npinfo = NULL; 828 } 829 } 830 831 dev_put(np->dev); 832 } 833 834 np->dev = NULL; 835 } 836 837 int netpoll_trap(void) 838 { 839 return atomic_read(&trapped); 840 } 841 842 void netpoll_set_trap(int trap) 843 { 844 if (trap) 845 atomic_inc(&trapped); 846 else 847 atomic_dec(&trapped); 848 } 849 850 EXPORT_SYMBOL(netpoll_set_trap); 851 EXPORT_SYMBOL(netpoll_trap); 852 EXPORT_SYMBOL(netpoll_print_options); 853 EXPORT_SYMBOL(netpoll_parse_options); 854 EXPORT_SYMBOL(netpoll_setup); 855 EXPORT_SYMBOL(netpoll_cleanup); 856 EXPORT_SYMBOL(netpoll_send_udp); 857 EXPORT_SYMBOL(netpoll_poll); 858