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 #include <trace/events/napi.h> 28 29 /* 30 * We maintain a small pool of fully-sized skbs, to make sure the 31 * message gets out even in extreme OOM situations. 32 */ 33 34 #define MAX_UDP_CHUNK 1460 35 #define MAX_SKBS 32 36 #define MAX_QUEUE_DEPTH (MAX_SKBS / 2) 37 38 static struct sk_buff_head skb_pool; 39 40 static atomic_t trapped; 41 42 #define USEC_PER_POLL 50 43 #define NETPOLL_RX_ENABLED 1 44 #define NETPOLL_RX_DROP 2 45 46 #define MAX_SKB_SIZE \ 47 (MAX_UDP_CHUNK + sizeof(struct udphdr) + \ 48 sizeof(struct iphdr) + sizeof(struct ethhdr)) 49 50 static void zap_completion_queue(void); 51 static void arp_reply(struct sk_buff *skb); 52 53 static void queue_process(struct work_struct *work) 54 { 55 struct netpoll_info *npinfo = 56 container_of(work, struct netpoll_info, tx_work.work); 57 struct sk_buff *skb; 58 unsigned long flags; 59 60 while ((skb = skb_dequeue(&npinfo->txq))) { 61 struct net_device *dev = skb->dev; 62 const struct net_device_ops *ops = dev->netdev_ops; 63 struct netdev_queue *txq; 64 65 if (!netif_device_present(dev) || !netif_running(dev)) { 66 __kfree_skb(skb); 67 continue; 68 } 69 70 txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb)); 71 72 local_irq_save(flags); 73 __netif_tx_lock(txq, smp_processor_id()); 74 if (netif_tx_queue_stopped(txq) || 75 netif_tx_queue_frozen(txq) || 76 ops->ndo_start_xmit(skb, dev) != NETDEV_TX_OK) { 77 skb_queue_head(&npinfo->txq, skb); 78 __netif_tx_unlock(txq); 79 local_irq_restore(flags); 80 81 schedule_delayed_work(&npinfo->tx_work, HZ/10); 82 return; 83 } 84 __netif_tx_unlock(txq); 85 local_irq_restore(flags); 86 } 87 } 88 89 static __sum16 checksum_udp(struct sk_buff *skb, struct udphdr *uh, 90 unsigned short ulen, __be32 saddr, __be32 daddr) 91 { 92 __wsum psum; 93 94 if (uh->check == 0 || skb_csum_unnecessary(skb)) 95 return 0; 96 97 psum = csum_tcpudp_nofold(saddr, daddr, ulen, IPPROTO_UDP, 0); 98 99 if (skb->ip_summed == CHECKSUM_COMPLETE && 100 !csum_fold(csum_add(psum, skb->csum))) 101 return 0; 102 103 skb->csum = psum; 104 105 return __skb_checksum_complete(skb); 106 } 107 108 /* 109 * Check whether delayed processing was scheduled for our NIC. If so, 110 * we attempt to grab the poll lock and use ->poll() to pump the card. 111 * If this fails, either we've recursed in ->poll() or it's already 112 * running on another CPU. 113 * 114 * Note: we don't mask interrupts with this lock because we're using 115 * trylock here and interrupts are already disabled in the softirq 116 * case. Further, we test the poll_owner to avoid recursion on UP 117 * systems where the lock doesn't exist. 118 * 119 * In cases where there is bi-directional communications, reading only 120 * one message at a time can lead to packets being dropped by the 121 * network adapter, forcing superfluous retries and possibly timeouts. 122 * Thus, we set our budget to greater than 1. 123 */ 124 static int poll_one_napi(struct netpoll_info *npinfo, 125 struct napi_struct *napi, int budget) 126 { 127 int work; 128 129 /* net_rx_action's ->poll() invocations and our's are 130 * synchronized by this test which is only made while 131 * holding the napi->poll_lock. 132 */ 133 if (!test_bit(NAPI_STATE_SCHED, &napi->state)) 134 return budget; 135 136 npinfo->rx_flags |= NETPOLL_RX_DROP; 137 atomic_inc(&trapped); 138 set_bit(NAPI_STATE_NPSVC, &napi->state); 139 140 work = napi->poll(napi, budget); 141 trace_napi_poll(napi); 142 143 clear_bit(NAPI_STATE_NPSVC, &napi->state); 144 atomic_dec(&trapped); 145 npinfo->rx_flags &= ~NETPOLL_RX_DROP; 146 147 return budget - work; 148 } 149 150 static void poll_napi(struct net_device *dev) 151 { 152 struct napi_struct *napi; 153 int budget = 16; 154 155 list_for_each_entry(napi, &dev->napi_list, dev_list) { 156 if (napi->poll_owner != smp_processor_id() && 157 spin_trylock(&napi->poll_lock)) { 158 budget = poll_one_napi(dev->npinfo, napi, budget); 159 spin_unlock(&napi->poll_lock); 160 161 if (!budget) 162 break; 163 } 164 } 165 } 166 167 static void service_arp_queue(struct netpoll_info *npi) 168 { 169 if (npi) { 170 struct sk_buff *skb; 171 172 while ((skb = skb_dequeue(&npi->arp_tx))) 173 arp_reply(skb); 174 } 175 } 176 177 void netpoll_poll(struct netpoll *np) 178 { 179 struct net_device *dev = np->dev; 180 const struct net_device_ops *ops; 181 182 if (!dev || !netif_running(dev)) 183 return; 184 185 ops = dev->netdev_ops; 186 if (!ops->ndo_poll_controller) 187 return; 188 189 /* Process pending work on NIC */ 190 ops->ndo_poll_controller(dev); 191 192 poll_napi(dev); 193 194 service_arp_queue(dev->npinfo); 195 196 zap_completion_queue(); 197 } 198 199 static void refill_skbs(void) 200 { 201 struct sk_buff *skb; 202 unsigned long flags; 203 204 spin_lock_irqsave(&skb_pool.lock, flags); 205 while (skb_pool.qlen < MAX_SKBS) { 206 skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC); 207 if (!skb) 208 break; 209 210 __skb_queue_tail(&skb_pool, skb); 211 } 212 spin_unlock_irqrestore(&skb_pool.lock, flags); 213 } 214 215 static void zap_completion_queue(void) 216 { 217 unsigned long flags; 218 struct softnet_data *sd = &get_cpu_var(softnet_data); 219 220 if (sd->completion_queue) { 221 struct sk_buff *clist; 222 223 local_irq_save(flags); 224 clist = sd->completion_queue; 225 sd->completion_queue = NULL; 226 local_irq_restore(flags); 227 228 while (clist != NULL) { 229 struct sk_buff *skb = clist; 230 clist = clist->next; 231 if (skb->destructor) { 232 atomic_inc(&skb->users); 233 dev_kfree_skb_any(skb); /* put this one back */ 234 } else { 235 __kfree_skb(skb); 236 } 237 } 238 } 239 240 put_cpu_var(softnet_data); 241 } 242 243 static struct sk_buff *find_skb(struct netpoll *np, int len, int reserve) 244 { 245 int count = 0; 246 struct sk_buff *skb; 247 248 zap_completion_queue(); 249 refill_skbs(); 250 repeat: 251 252 skb = alloc_skb(len, GFP_ATOMIC); 253 if (!skb) 254 skb = skb_dequeue(&skb_pool); 255 256 if (!skb) { 257 if (++count < 10) { 258 netpoll_poll(np); 259 goto repeat; 260 } 261 return NULL; 262 } 263 264 atomic_set(&skb->users, 1); 265 skb_reserve(skb, reserve); 266 return skb; 267 } 268 269 static int netpoll_owner_active(struct net_device *dev) 270 { 271 struct napi_struct *napi; 272 273 list_for_each_entry(napi, &dev->napi_list, dev_list) { 274 if (napi->poll_owner == smp_processor_id()) 275 return 1; 276 } 277 return 0; 278 } 279 280 static void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb) 281 { 282 int status = NETDEV_TX_BUSY; 283 unsigned long tries; 284 struct net_device *dev = np->dev; 285 const struct net_device_ops *ops = dev->netdev_ops; 286 struct netpoll_info *npinfo = np->dev->npinfo; 287 288 if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) { 289 __kfree_skb(skb); 290 return; 291 } 292 293 /* don't get messages out of order, and no recursion */ 294 if (skb_queue_len(&npinfo->txq) == 0 && !netpoll_owner_active(dev)) { 295 struct netdev_queue *txq; 296 unsigned long flags; 297 298 txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb)); 299 300 local_irq_save(flags); 301 /* try until next clock tick */ 302 for (tries = jiffies_to_usecs(1)/USEC_PER_POLL; 303 tries > 0; --tries) { 304 if (__netif_tx_trylock(txq)) { 305 if (!netif_tx_queue_stopped(txq)) { 306 status = ops->ndo_start_xmit(skb, dev); 307 if (status == NETDEV_TX_OK) 308 txq_trans_update(txq); 309 } 310 __netif_tx_unlock(txq); 311 312 if (status == NETDEV_TX_OK) 313 break; 314 315 } 316 317 /* tickle device maybe there is some cleanup */ 318 netpoll_poll(np); 319 320 udelay(USEC_PER_POLL); 321 } 322 local_irq_restore(flags); 323 } 324 325 if (status != NETDEV_TX_OK) { 326 skb_queue_tail(&npinfo->txq, skb); 327 schedule_delayed_work(&npinfo->tx_work,0); 328 } 329 } 330 331 void netpoll_send_udp(struct netpoll *np, const char *msg, int len) 332 { 333 int total_len, eth_len, ip_len, udp_len; 334 struct sk_buff *skb; 335 struct udphdr *udph; 336 struct iphdr *iph; 337 struct ethhdr *eth; 338 339 udp_len = len + sizeof(*udph); 340 ip_len = eth_len = udp_len + sizeof(*iph); 341 total_len = eth_len + ETH_HLEN + NET_IP_ALIGN; 342 343 skb = find_skb(np, total_len, total_len - len); 344 if (!skb) 345 return; 346 347 skb_copy_to_linear_data(skb, msg, len); 348 skb->len += len; 349 350 skb_push(skb, sizeof(*udph)); 351 skb_reset_transport_header(skb); 352 udph = udp_hdr(skb); 353 udph->source = htons(np->local_port); 354 udph->dest = htons(np->remote_port); 355 udph->len = htons(udp_len); 356 udph->check = 0; 357 udph->check = csum_tcpudp_magic(np->local_ip, 358 np->remote_ip, 359 udp_len, IPPROTO_UDP, 360 csum_partial(udph, udp_len, 0)); 361 if (udph->check == 0) 362 udph->check = CSUM_MANGLED_0; 363 364 skb_push(skb, sizeof(*iph)); 365 skb_reset_network_header(skb); 366 iph = ip_hdr(skb); 367 368 /* iph->version = 4; iph->ihl = 5; */ 369 put_unaligned(0x45, (unsigned char *)iph); 370 iph->tos = 0; 371 put_unaligned(htons(ip_len), &(iph->tot_len)); 372 iph->id = 0; 373 iph->frag_off = 0; 374 iph->ttl = 64; 375 iph->protocol = IPPROTO_UDP; 376 iph->check = 0; 377 put_unaligned(np->local_ip, &(iph->saddr)); 378 put_unaligned(np->remote_ip, &(iph->daddr)); 379 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); 380 381 eth = (struct ethhdr *) skb_push(skb, ETH_HLEN); 382 skb_reset_mac_header(skb); 383 skb->protocol = eth->h_proto = htons(ETH_P_IP); 384 memcpy(eth->h_source, np->dev->dev_addr, ETH_ALEN); 385 memcpy(eth->h_dest, np->remote_mac, ETH_ALEN); 386 387 skb->dev = np->dev; 388 389 netpoll_send_skb(np, skb); 390 } 391 392 static void arp_reply(struct sk_buff *skb) 393 { 394 struct netpoll_info *npinfo = skb->dev->npinfo; 395 struct arphdr *arp; 396 unsigned char *arp_ptr; 397 int size, type = ARPOP_REPLY, ptype = ETH_P_ARP; 398 __be32 sip, tip; 399 unsigned char *sha; 400 struct sk_buff *send_skb; 401 struct netpoll *np = NULL; 402 403 if (npinfo->rx_np && npinfo->rx_np->dev == skb->dev) 404 np = npinfo->rx_np; 405 if (!np) 406 return; 407 408 /* No arp on this interface */ 409 if (skb->dev->flags & IFF_NOARP) 410 return; 411 412 if (!pskb_may_pull(skb, arp_hdr_len(skb->dev))) 413 return; 414 415 skb_reset_network_header(skb); 416 skb_reset_transport_header(skb); 417 arp = arp_hdr(skb); 418 419 if ((arp->ar_hrd != htons(ARPHRD_ETHER) && 420 arp->ar_hrd != htons(ARPHRD_IEEE802)) || 421 arp->ar_pro != htons(ETH_P_IP) || 422 arp->ar_op != htons(ARPOP_REQUEST)) 423 return; 424 425 arp_ptr = (unsigned char *)(arp+1); 426 /* save the location of the src hw addr */ 427 sha = arp_ptr; 428 arp_ptr += skb->dev->addr_len; 429 memcpy(&sip, arp_ptr, 4); 430 arp_ptr += 4; 431 /* if we actually cared about dst hw addr, it would get copied here */ 432 arp_ptr += skb->dev->addr_len; 433 memcpy(&tip, arp_ptr, 4); 434 435 /* Should we ignore arp? */ 436 if (tip != np->local_ip || 437 ipv4_is_loopback(tip) || ipv4_is_multicast(tip)) 438 return; 439 440 size = arp_hdr_len(skb->dev); 441 send_skb = find_skb(np, size + LL_ALLOCATED_SPACE(np->dev), 442 LL_RESERVED_SPACE(np->dev)); 443 444 if (!send_skb) 445 return; 446 447 skb_reset_network_header(send_skb); 448 arp = (struct arphdr *) skb_put(send_skb, size); 449 send_skb->dev = skb->dev; 450 send_skb->protocol = htons(ETH_P_ARP); 451 452 /* Fill the device header for the ARP frame */ 453 if (dev_hard_header(send_skb, skb->dev, ptype, 454 sha, np->dev->dev_addr, 455 send_skb->len) < 0) { 456 kfree_skb(send_skb); 457 return; 458 } 459 460 /* 461 * Fill out the arp protocol part. 462 * 463 * we only support ethernet device type, 464 * which (according to RFC 1390) should always equal 1 (Ethernet). 465 */ 466 467 arp->ar_hrd = htons(np->dev->type); 468 arp->ar_pro = htons(ETH_P_IP); 469 arp->ar_hln = np->dev->addr_len; 470 arp->ar_pln = 4; 471 arp->ar_op = htons(type); 472 473 arp_ptr=(unsigned char *)(arp + 1); 474 memcpy(arp_ptr, np->dev->dev_addr, np->dev->addr_len); 475 arp_ptr += np->dev->addr_len; 476 memcpy(arp_ptr, &tip, 4); 477 arp_ptr += 4; 478 memcpy(arp_ptr, sha, np->dev->addr_len); 479 arp_ptr += np->dev->addr_len; 480 memcpy(arp_ptr, &sip, 4); 481 482 netpoll_send_skb(np, send_skb); 483 } 484 485 int __netpoll_rx(struct sk_buff *skb) 486 { 487 int proto, len, ulen; 488 struct iphdr *iph; 489 struct udphdr *uh; 490 struct netpoll_info *npi = skb->dev->npinfo; 491 struct netpoll *np = npi->rx_np; 492 493 if (!np) 494 goto out; 495 if (skb->dev->type != ARPHRD_ETHER) 496 goto out; 497 498 /* check if netpoll clients need ARP */ 499 if (skb->protocol == htons(ETH_P_ARP) && 500 atomic_read(&trapped)) { 501 skb_queue_tail(&npi->arp_tx, skb); 502 return 1; 503 } 504 505 proto = ntohs(eth_hdr(skb)->h_proto); 506 if (proto != ETH_P_IP) 507 goto out; 508 if (skb->pkt_type == PACKET_OTHERHOST) 509 goto out; 510 if (skb_shared(skb)) 511 goto out; 512 513 iph = (struct iphdr *)skb->data; 514 if (!pskb_may_pull(skb, sizeof(struct iphdr))) 515 goto out; 516 if (iph->ihl < 5 || iph->version != 4) 517 goto out; 518 if (!pskb_may_pull(skb, iph->ihl*4)) 519 goto out; 520 if (ip_fast_csum((u8 *)iph, iph->ihl) != 0) 521 goto out; 522 523 len = ntohs(iph->tot_len); 524 if (skb->len < len || len < iph->ihl*4) 525 goto out; 526 527 /* 528 * Our transport medium may have padded the buffer out. 529 * Now We trim to the true length of the frame. 530 */ 531 if (pskb_trim_rcsum(skb, len)) 532 goto out; 533 534 if (iph->protocol != IPPROTO_UDP) 535 goto out; 536 537 len -= iph->ihl*4; 538 uh = (struct udphdr *)(((char *)iph) + iph->ihl*4); 539 ulen = ntohs(uh->len); 540 541 if (ulen != len) 542 goto out; 543 if (checksum_udp(skb, uh, ulen, iph->saddr, iph->daddr)) 544 goto out; 545 if (np->local_ip && np->local_ip != iph->daddr) 546 goto out; 547 if (np->remote_ip && np->remote_ip != iph->saddr) 548 goto out; 549 if (np->local_port && np->local_port != ntohs(uh->dest)) 550 goto out; 551 552 np->rx_hook(np, ntohs(uh->source), 553 (char *)(uh+1), 554 ulen - sizeof(struct udphdr)); 555 556 kfree_skb(skb); 557 return 1; 558 559 out: 560 if (atomic_read(&trapped)) { 561 kfree_skb(skb); 562 return 1; 563 } 564 565 return 0; 566 } 567 568 void netpoll_print_options(struct netpoll *np) 569 { 570 printk(KERN_INFO "%s: local port %d\n", 571 np->name, np->local_port); 572 printk(KERN_INFO "%s: local IP %pI4\n", 573 np->name, &np->local_ip); 574 printk(KERN_INFO "%s: interface %s\n", 575 np->name, np->dev_name); 576 printk(KERN_INFO "%s: remote port %d\n", 577 np->name, np->remote_port); 578 printk(KERN_INFO "%s: remote IP %pI4\n", 579 np->name, &np->remote_ip); 580 printk(KERN_INFO "%s: remote ethernet address %pM\n", 581 np->name, np->remote_mac); 582 } 583 584 int netpoll_parse_options(struct netpoll *np, char *opt) 585 { 586 char *cur=opt, *delim; 587 588 if (*cur != '@') { 589 if ((delim = strchr(cur, '@')) == NULL) 590 goto parse_failed; 591 *delim = 0; 592 np->local_port = simple_strtol(cur, NULL, 10); 593 cur = delim; 594 } 595 cur++; 596 597 if (*cur != '/') { 598 if ((delim = strchr(cur, '/')) == NULL) 599 goto parse_failed; 600 *delim = 0; 601 np->local_ip = in_aton(cur); 602 cur = delim; 603 } 604 cur++; 605 606 if (*cur != ',') { 607 /* parse out dev name */ 608 if ((delim = strchr(cur, ',')) == NULL) 609 goto parse_failed; 610 *delim = 0; 611 strlcpy(np->dev_name, cur, sizeof(np->dev_name)); 612 cur = delim; 613 } 614 cur++; 615 616 if (*cur != '@') { 617 /* dst port */ 618 if ((delim = strchr(cur, '@')) == NULL) 619 goto parse_failed; 620 *delim = 0; 621 np->remote_port = simple_strtol(cur, NULL, 10); 622 cur = delim; 623 } 624 cur++; 625 626 /* dst ip */ 627 if ((delim = strchr(cur, '/')) == NULL) 628 goto parse_failed; 629 *delim = 0; 630 np->remote_ip = in_aton(cur); 631 cur = delim + 1; 632 633 if (*cur != 0) { 634 /* MAC address */ 635 if ((delim = strchr(cur, ':')) == NULL) 636 goto parse_failed; 637 *delim = 0; 638 np->remote_mac[0] = 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[1] = 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[2] = 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[3] = simple_strtol(cur, NULL, 16); 654 cur = delim + 1; 655 if ((delim = strchr(cur, ':')) == NULL) 656 goto parse_failed; 657 *delim = 0; 658 np->remote_mac[4] = simple_strtol(cur, NULL, 16); 659 cur = delim + 1; 660 np->remote_mac[5] = simple_strtol(cur, NULL, 16); 661 } 662 663 netpoll_print_options(np); 664 665 return 0; 666 667 parse_failed: 668 printk(KERN_INFO "%s: couldn't parse config at %s!\n", 669 np->name, cur); 670 return -1; 671 } 672 673 int netpoll_setup(struct netpoll *np) 674 { 675 struct net_device *ndev = NULL; 676 struct in_device *in_dev; 677 struct netpoll_info *npinfo; 678 unsigned long flags; 679 int err; 680 681 if (np->dev_name) 682 ndev = dev_get_by_name(&init_net, np->dev_name); 683 if (!ndev) { 684 printk(KERN_ERR "%s: %s doesn't exist, aborting.\n", 685 np->name, np->dev_name); 686 return -ENODEV; 687 } 688 689 np->dev = ndev; 690 if (!ndev->npinfo) { 691 npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL); 692 if (!npinfo) { 693 err = -ENOMEM; 694 goto release; 695 } 696 697 npinfo->rx_flags = 0; 698 npinfo->rx_np = NULL; 699 700 spin_lock_init(&npinfo->rx_lock); 701 skb_queue_head_init(&npinfo->arp_tx); 702 skb_queue_head_init(&npinfo->txq); 703 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process); 704 705 atomic_set(&npinfo->refcnt, 1); 706 } else { 707 npinfo = ndev->npinfo; 708 atomic_inc(&npinfo->refcnt); 709 } 710 711 if (!ndev->netdev_ops->ndo_poll_controller) { 712 printk(KERN_ERR "%s: %s doesn't support polling, aborting.\n", 713 np->name, np->dev_name); 714 err = -ENOTSUPP; 715 goto release; 716 } 717 718 if (!netif_running(ndev)) { 719 unsigned long atmost, atleast; 720 721 printk(KERN_INFO "%s: device %s not up yet, forcing it\n", 722 np->name, np->dev_name); 723 724 rtnl_lock(); 725 err = dev_open(ndev); 726 rtnl_unlock(); 727 728 if (err) { 729 printk(KERN_ERR "%s: failed to open %s\n", 730 np->name, ndev->name); 731 goto release; 732 } 733 734 atleast = jiffies + HZ/10; 735 atmost = jiffies + 4*HZ; 736 while (!netif_carrier_ok(ndev)) { 737 if (time_after(jiffies, atmost)) { 738 printk(KERN_NOTICE 739 "%s: timeout waiting for carrier\n", 740 np->name); 741 break; 742 } 743 msleep(1); 744 } 745 746 /* If carrier appears to come up instantly, we don't 747 * trust it and pause so that we don't pump all our 748 * queued console messages into the bitbucket. 749 */ 750 751 if (time_before(jiffies, atleast)) { 752 printk(KERN_NOTICE "%s: carrier detect appears" 753 " untrustworthy, waiting 4 seconds\n", 754 np->name); 755 msleep(4000); 756 } 757 } 758 759 if (!np->local_ip) { 760 rcu_read_lock(); 761 in_dev = __in_dev_get_rcu(ndev); 762 763 if (!in_dev || !in_dev->ifa_list) { 764 rcu_read_unlock(); 765 printk(KERN_ERR "%s: no IP address for %s, aborting\n", 766 np->name, np->dev_name); 767 err = -EDESTADDRREQ; 768 goto release; 769 } 770 771 np->local_ip = in_dev->ifa_list->ifa_local; 772 rcu_read_unlock(); 773 printk(KERN_INFO "%s: local IP %pI4\n", np->name, &np->local_ip); 774 } 775 776 if (np->rx_hook) { 777 spin_lock_irqsave(&npinfo->rx_lock, flags); 778 npinfo->rx_flags |= NETPOLL_RX_ENABLED; 779 npinfo->rx_np = np; 780 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 781 } 782 783 /* fill up the skb queue */ 784 refill_skbs(); 785 786 /* last thing to do is link it to the net device structure */ 787 ndev->npinfo = npinfo; 788 789 /* avoid racing with NAPI reading npinfo */ 790 synchronize_rcu(); 791 792 return 0; 793 794 release: 795 if (!ndev->npinfo) 796 kfree(npinfo); 797 np->dev = NULL; 798 dev_put(ndev); 799 return err; 800 } 801 802 static int __init netpoll_init(void) 803 { 804 skb_queue_head_init(&skb_pool); 805 return 0; 806 } 807 core_initcall(netpoll_init); 808 809 void netpoll_cleanup(struct netpoll *np) 810 { 811 struct netpoll_info *npinfo; 812 unsigned long flags; 813 814 if (np->dev) { 815 npinfo = np->dev->npinfo; 816 if (npinfo) { 817 if (npinfo->rx_np == np) { 818 spin_lock_irqsave(&npinfo->rx_lock, flags); 819 npinfo->rx_np = NULL; 820 npinfo->rx_flags &= ~NETPOLL_RX_ENABLED; 821 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 822 } 823 824 if (atomic_dec_and_test(&npinfo->refcnt)) { 825 skb_queue_purge(&npinfo->arp_tx); 826 skb_queue_purge(&npinfo->txq); 827 cancel_rearming_delayed_work(&npinfo->tx_work); 828 829 /* clean after last, unfinished work */ 830 __skb_queue_purge(&npinfo->txq); 831 kfree(npinfo); 832 np->dev->npinfo = NULL; 833 } 834 } 835 836 dev_put(np->dev); 837 } 838 839 np->dev = NULL; 840 } 841 842 int netpoll_trap(void) 843 { 844 return atomic_read(&trapped); 845 } 846 847 void netpoll_set_trap(int trap) 848 { 849 if (trap) 850 atomic_inc(&trapped); 851 else 852 atomic_dec(&trapped); 853 } 854 855 EXPORT_SYMBOL(netpoll_set_trap); 856 EXPORT_SYMBOL(netpoll_trap); 857 EXPORT_SYMBOL(netpoll_print_options); 858 EXPORT_SYMBOL(netpoll_parse_options); 859 EXPORT_SYMBOL(netpoll_setup); 860 EXPORT_SYMBOL(netpoll_cleanup); 861 EXPORT_SYMBOL(netpoll_send_udp); 862 EXPORT_SYMBOL(netpoll_poll); 863