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