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