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