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