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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 13 14 #include <linux/moduleparam.h> 15 #include <linux/kernel.h> 16 #include <linux/netdevice.h> 17 #include <linux/etherdevice.h> 18 #include <linux/string.h> 19 #include <linux/if_arp.h> 20 #include <linux/inetdevice.h> 21 #include <linux/inet.h> 22 #include <linux/interrupt.h> 23 #include <linux/netpoll.h> 24 #include <linux/sched.h> 25 #include <linux/delay.h> 26 #include <linux/rcupdate.h> 27 #include <linux/workqueue.h> 28 #include <linux/slab.h> 29 #include <linux/export.h> 30 #include <linux/if_vlan.h> 31 #include <net/tcp.h> 32 #include <net/udp.h> 33 #include <net/addrconf.h> 34 #include <net/ndisc.h> 35 #include <net/ip6_checksum.h> 36 #include <asm/unaligned.h> 37 #include <trace/events/napi.h> 38 39 /* 40 * We maintain a small pool of fully-sized skbs, to make sure the 41 * message gets out even in extreme OOM situations. 42 */ 43 44 #define MAX_UDP_CHUNK 1460 45 #define MAX_SKBS 32 46 47 static struct sk_buff_head skb_pool; 48 49 DEFINE_STATIC_SRCU(netpoll_srcu); 50 51 #define USEC_PER_POLL 50 52 53 #define MAX_SKB_SIZE \ 54 (sizeof(struct ethhdr) + \ 55 sizeof(struct iphdr) + \ 56 sizeof(struct udphdr) + \ 57 MAX_UDP_CHUNK) 58 59 static void zap_completion_queue(void); 60 static void netpoll_async_cleanup(struct work_struct *work); 61 62 static unsigned int carrier_timeout = 4; 63 module_param(carrier_timeout, uint, 0644); 64 65 #define np_info(np, fmt, ...) \ 66 pr_info("%s: " fmt, np->name, ##__VA_ARGS__) 67 #define np_err(np, fmt, ...) \ 68 pr_err("%s: " fmt, np->name, ##__VA_ARGS__) 69 #define np_notice(np, fmt, ...) \ 70 pr_notice("%s: " fmt, np->name, ##__VA_ARGS__) 71 72 static int netpoll_start_xmit(struct sk_buff *skb, struct net_device *dev, 73 struct netdev_queue *txq) 74 { 75 int status = NETDEV_TX_OK; 76 netdev_features_t features; 77 78 features = netif_skb_features(skb); 79 80 if (skb_vlan_tag_present(skb) && 81 !vlan_hw_offload_capable(features, skb->vlan_proto)) { 82 skb = __vlan_hwaccel_push_inside(skb); 83 if (unlikely(!skb)) { 84 /* This is actually a packet drop, but we 85 * don't want the code that calls this 86 * function to try and operate on a NULL skb. 87 */ 88 goto out; 89 } 90 } 91 92 status = netdev_start_xmit(skb, dev, txq, false); 93 94 out: 95 return status; 96 } 97 98 static void queue_process(struct work_struct *work) 99 { 100 struct netpoll_info *npinfo = 101 container_of(work, struct netpoll_info, tx_work.work); 102 struct sk_buff *skb; 103 unsigned long flags; 104 105 while ((skb = skb_dequeue(&npinfo->txq))) { 106 struct net_device *dev = skb->dev; 107 struct netdev_queue *txq; 108 109 if (!netif_device_present(dev) || !netif_running(dev)) { 110 kfree_skb(skb); 111 continue; 112 } 113 114 txq = skb_get_tx_queue(dev, skb); 115 116 local_irq_save(flags); 117 HARD_TX_LOCK(dev, txq, smp_processor_id()); 118 if (netif_xmit_frozen_or_stopped(txq) || 119 netpoll_start_xmit(skb, dev, txq) != NETDEV_TX_OK) { 120 skb_queue_head(&npinfo->txq, skb); 121 HARD_TX_UNLOCK(dev, txq); 122 local_irq_restore(flags); 123 124 schedule_delayed_work(&npinfo->tx_work, HZ/10); 125 return; 126 } 127 HARD_TX_UNLOCK(dev, txq); 128 local_irq_restore(flags); 129 } 130 } 131 132 /* 133 * Check whether delayed processing was scheduled for our NIC. If so, 134 * we attempt to grab the poll lock and use ->poll() to pump the card. 135 * If this fails, either we've recursed in ->poll() or it's already 136 * running on another CPU. 137 * 138 * Note: we don't mask interrupts with this lock because we're using 139 * trylock here and interrupts are already disabled in the softirq 140 * case. Further, we test the poll_owner to avoid recursion on UP 141 * systems where the lock doesn't exist. 142 */ 143 static int poll_one_napi(struct napi_struct *napi, int budget) 144 { 145 int work = 0; 146 147 /* net_rx_action's ->poll() invocations and our's are 148 * synchronized by this test which is only made while 149 * holding the napi->poll_lock. 150 */ 151 if (!test_bit(NAPI_STATE_SCHED, &napi->state)) 152 return budget; 153 154 /* If we set this bit but see that it has already been set, 155 * that indicates that napi has been disabled and we need 156 * to abort this operation 157 */ 158 if (test_and_set_bit(NAPI_STATE_NPSVC, &napi->state)) 159 goto out; 160 161 work = napi->poll(napi, budget); 162 WARN_ONCE(work > budget, "%pF exceeded budget in poll\n", napi->poll); 163 trace_napi_poll(napi); 164 165 clear_bit(NAPI_STATE_NPSVC, &napi->state); 166 167 out: 168 return budget - work; 169 } 170 171 static void poll_napi(struct net_device *dev, int budget) 172 { 173 struct napi_struct *napi; 174 175 list_for_each_entry(napi, &dev->napi_list, dev_list) { 176 if (napi->poll_owner != smp_processor_id() && 177 spin_trylock(&napi->poll_lock)) { 178 budget = poll_one_napi(napi, budget); 179 spin_unlock(&napi->poll_lock); 180 } 181 } 182 } 183 184 static void netpoll_poll_dev(struct net_device *dev) 185 { 186 const struct net_device_ops *ops; 187 struct netpoll_info *ni = rcu_dereference_bh(dev->npinfo); 188 int budget = 0; 189 190 /* Don't do any rx activity if the dev_lock mutex is held 191 * the dev_open/close paths use this to block netpoll activity 192 * while changing device state 193 */ 194 if (down_trylock(&ni->dev_lock)) 195 return; 196 197 if (!netif_running(dev)) { 198 up(&ni->dev_lock); 199 return; 200 } 201 202 ops = dev->netdev_ops; 203 if (!ops->ndo_poll_controller) { 204 up(&ni->dev_lock); 205 return; 206 } 207 208 /* Process pending work on NIC */ 209 ops->ndo_poll_controller(dev); 210 211 poll_napi(dev, budget); 212 213 up(&ni->dev_lock); 214 215 zap_completion_queue(); 216 } 217 218 void netpoll_poll_disable(struct net_device *dev) 219 { 220 struct netpoll_info *ni; 221 int idx; 222 might_sleep(); 223 idx = srcu_read_lock(&netpoll_srcu); 224 ni = srcu_dereference(dev->npinfo, &netpoll_srcu); 225 if (ni) 226 down(&ni->dev_lock); 227 srcu_read_unlock(&netpoll_srcu, idx); 228 } 229 EXPORT_SYMBOL(netpoll_poll_disable); 230 231 void netpoll_poll_enable(struct net_device *dev) 232 { 233 struct netpoll_info *ni; 234 rcu_read_lock(); 235 ni = rcu_dereference(dev->npinfo); 236 if (ni) 237 up(&ni->dev_lock); 238 rcu_read_unlock(); 239 } 240 EXPORT_SYMBOL(netpoll_poll_enable); 241 242 static void refill_skbs(void) 243 { 244 struct sk_buff *skb; 245 unsigned long flags; 246 247 spin_lock_irqsave(&skb_pool.lock, flags); 248 while (skb_pool.qlen < MAX_SKBS) { 249 skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC); 250 if (!skb) 251 break; 252 253 __skb_queue_tail(&skb_pool, skb); 254 } 255 spin_unlock_irqrestore(&skb_pool.lock, flags); 256 } 257 258 static void zap_completion_queue(void) 259 { 260 unsigned long flags; 261 struct softnet_data *sd = &get_cpu_var(softnet_data); 262 263 if (sd->completion_queue) { 264 struct sk_buff *clist; 265 266 local_irq_save(flags); 267 clist = sd->completion_queue; 268 sd->completion_queue = NULL; 269 local_irq_restore(flags); 270 271 while (clist != NULL) { 272 struct sk_buff *skb = clist; 273 clist = clist->next; 274 if (!skb_irq_freeable(skb)) { 275 atomic_inc(&skb->users); 276 dev_kfree_skb_any(skb); /* put this one back */ 277 } else { 278 __kfree_skb(skb); 279 } 280 } 281 } 282 283 put_cpu_var(softnet_data); 284 } 285 286 static struct sk_buff *find_skb(struct netpoll *np, int len, int reserve) 287 { 288 int count = 0; 289 struct sk_buff *skb; 290 291 zap_completion_queue(); 292 refill_skbs(); 293 repeat: 294 295 skb = alloc_skb(len, GFP_ATOMIC); 296 if (!skb) 297 skb = skb_dequeue(&skb_pool); 298 299 if (!skb) { 300 if (++count < 10) { 301 netpoll_poll_dev(np->dev); 302 goto repeat; 303 } 304 return NULL; 305 } 306 307 atomic_set(&skb->users, 1); 308 skb_reserve(skb, reserve); 309 return skb; 310 } 311 312 static int netpoll_owner_active(struct net_device *dev) 313 { 314 struct napi_struct *napi; 315 316 list_for_each_entry(napi, &dev->napi_list, dev_list) { 317 if (napi->poll_owner == smp_processor_id()) 318 return 1; 319 } 320 return 0; 321 } 322 323 /* call with IRQ disabled */ 324 void netpoll_send_skb_on_dev(struct netpoll *np, struct sk_buff *skb, 325 struct net_device *dev) 326 { 327 int status = NETDEV_TX_BUSY; 328 unsigned long tries; 329 /* It is up to the caller to keep npinfo alive. */ 330 struct netpoll_info *npinfo; 331 332 WARN_ON_ONCE(!irqs_disabled()); 333 334 npinfo = rcu_dereference_bh(np->dev->npinfo); 335 if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) { 336 dev_kfree_skb_irq(skb); 337 return; 338 } 339 340 /* don't get messages out of order, and no recursion */ 341 if (skb_queue_len(&npinfo->txq) == 0 && !netpoll_owner_active(dev)) { 342 struct netdev_queue *txq; 343 344 txq = netdev_pick_tx(dev, skb, NULL); 345 346 /* try until next clock tick */ 347 for (tries = jiffies_to_usecs(1)/USEC_PER_POLL; 348 tries > 0; --tries) { 349 if (HARD_TX_TRYLOCK(dev, txq)) { 350 if (!netif_xmit_stopped(txq)) 351 status = netpoll_start_xmit(skb, dev, txq); 352 353 HARD_TX_UNLOCK(dev, txq); 354 355 if (status == NETDEV_TX_OK) 356 break; 357 358 } 359 360 /* tickle device maybe there is some cleanup */ 361 netpoll_poll_dev(np->dev); 362 363 udelay(USEC_PER_POLL); 364 } 365 366 WARN_ONCE(!irqs_disabled(), 367 "netpoll_send_skb_on_dev(): %s enabled interrupts in poll (%pF)\n", 368 dev->name, dev->netdev_ops->ndo_start_xmit); 369 370 } 371 372 if (status != NETDEV_TX_OK) { 373 skb_queue_tail(&npinfo->txq, skb); 374 schedule_delayed_work(&npinfo->tx_work,0); 375 } 376 } 377 EXPORT_SYMBOL(netpoll_send_skb_on_dev); 378 379 void netpoll_send_udp(struct netpoll *np, const char *msg, int len) 380 { 381 int total_len, ip_len, udp_len; 382 struct sk_buff *skb; 383 struct udphdr *udph; 384 struct iphdr *iph; 385 struct ethhdr *eth; 386 static atomic_t ip_ident; 387 struct ipv6hdr *ip6h; 388 389 WARN_ON_ONCE(!irqs_disabled()); 390 391 udp_len = len + sizeof(*udph); 392 if (np->ipv6) 393 ip_len = udp_len + sizeof(*ip6h); 394 else 395 ip_len = udp_len + sizeof(*iph); 396 397 total_len = ip_len + LL_RESERVED_SPACE(np->dev); 398 399 skb = find_skb(np, total_len + np->dev->needed_tailroom, 400 total_len - len); 401 if (!skb) 402 return; 403 404 skb_copy_to_linear_data(skb, msg, len); 405 skb_put(skb, len); 406 407 skb_push(skb, sizeof(*udph)); 408 skb_reset_transport_header(skb); 409 udph = udp_hdr(skb); 410 udph->source = htons(np->local_port); 411 udph->dest = htons(np->remote_port); 412 udph->len = htons(udp_len); 413 414 if (np->ipv6) { 415 udph->check = 0; 416 udph->check = csum_ipv6_magic(&np->local_ip.in6, 417 &np->remote_ip.in6, 418 udp_len, IPPROTO_UDP, 419 csum_partial(udph, udp_len, 0)); 420 if (udph->check == 0) 421 udph->check = CSUM_MANGLED_0; 422 423 skb_push(skb, sizeof(*ip6h)); 424 skb_reset_network_header(skb); 425 ip6h = ipv6_hdr(skb); 426 427 /* ip6h->version = 6; ip6h->priority = 0; */ 428 put_unaligned(0x60, (unsigned char *)ip6h); 429 ip6h->flow_lbl[0] = 0; 430 ip6h->flow_lbl[1] = 0; 431 ip6h->flow_lbl[2] = 0; 432 433 ip6h->payload_len = htons(sizeof(struct udphdr) + len); 434 ip6h->nexthdr = IPPROTO_UDP; 435 ip6h->hop_limit = 32; 436 ip6h->saddr = np->local_ip.in6; 437 ip6h->daddr = np->remote_ip.in6; 438 439 eth = (struct ethhdr *) skb_push(skb, ETH_HLEN); 440 skb_reset_mac_header(skb); 441 skb->protocol = eth->h_proto = htons(ETH_P_IPV6); 442 } else { 443 udph->check = 0; 444 udph->check = csum_tcpudp_magic(np->local_ip.ip, 445 np->remote_ip.ip, 446 udp_len, IPPROTO_UDP, 447 csum_partial(udph, udp_len, 0)); 448 if (udph->check == 0) 449 udph->check = CSUM_MANGLED_0; 450 451 skb_push(skb, sizeof(*iph)); 452 skb_reset_network_header(skb); 453 iph = ip_hdr(skb); 454 455 /* iph->version = 4; iph->ihl = 5; */ 456 put_unaligned(0x45, (unsigned char *)iph); 457 iph->tos = 0; 458 put_unaligned(htons(ip_len), &(iph->tot_len)); 459 iph->id = htons(atomic_inc_return(&ip_ident)); 460 iph->frag_off = 0; 461 iph->ttl = 64; 462 iph->protocol = IPPROTO_UDP; 463 iph->check = 0; 464 put_unaligned(np->local_ip.ip, &(iph->saddr)); 465 put_unaligned(np->remote_ip.ip, &(iph->daddr)); 466 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); 467 468 eth = (struct ethhdr *) skb_push(skb, ETH_HLEN); 469 skb_reset_mac_header(skb); 470 skb->protocol = eth->h_proto = htons(ETH_P_IP); 471 } 472 473 ether_addr_copy(eth->h_source, np->dev->dev_addr); 474 ether_addr_copy(eth->h_dest, np->remote_mac); 475 476 skb->dev = np->dev; 477 478 netpoll_send_skb(np, skb); 479 } 480 EXPORT_SYMBOL(netpoll_send_udp); 481 482 void netpoll_print_options(struct netpoll *np) 483 { 484 np_info(np, "local port %d\n", np->local_port); 485 if (np->ipv6) 486 np_info(np, "local IPv6 address %pI6c\n", &np->local_ip.in6); 487 else 488 np_info(np, "local IPv4 address %pI4\n", &np->local_ip.ip); 489 np_info(np, "interface '%s'\n", np->dev_name); 490 np_info(np, "remote port %d\n", np->remote_port); 491 if (np->ipv6) 492 np_info(np, "remote IPv6 address %pI6c\n", &np->remote_ip.in6); 493 else 494 np_info(np, "remote IPv4 address %pI4\n", &np->remote_ip.ip); 495 np_info(np, "remote ethernet address %pM\n", np->remote_mac); 496 } 497 EXPORT_SYMBOL(netpoll_print_options); 498 499 static int netpoll_parse_ip_addr(const char *str, union inet_addr *addr) 500 { 501 const char *end; 502 503 if (!strchr(str, ':') && 504 in4_pton(str, -1, (void *)addr, -1, &end) > 0) { 505 if (!*end) 506 return 0; 507 } 508 if (in6_pton(str, -1, addr->in6.s6_addr, -1, &end) > 0) { 509 #if IS_ENABLED(CONFIG_IPV6) 510 if (!*end) 511 return 1; 512 #else 513 return -1; 514 #endif 515 } 516 return -1; 517 } 518 519 int netpoll_parse_options(struct netpoll *np, char *opt) 520 { 521 char *cur=opt, *delim; 522 int ipv6; 523 bool ipversion_set = false; 524 525 if (*cur != '@') { 526 if ((delim = strchr(cur, '@')) == NULL) 527 goto parse_failed; 528 *delim = 0; 529 if (kstrtou16(cur, 10, &np->local_port)) 530 goto parse_failed; 531 cur = delim; 532 } 533 cur++; 534 535 if (*cur != '/') { 536 ipversion_set = true; 537 if ((delim = strchr(cur, '/')) == NULL) 538 goto parse_failed; 539 *delim = 0; 540 ipv6 = netpoll_parse_ip_addr(cur, &np->local_ip); 541 if (ipv6 < 0) 542 goto parse_failed; 543 else 544 np->ipv6 = (bool)ipv6; 545 cur = delim; 546 } 547 cur++; 548 549 if (*cur != ',') { 550 /* parse out dev name */ 551 if ((delim = strchr(cur, ',')) == NULL) 552 goto parse_failed; 553 *delim = 0; 554 strlcpy(np->dev_name, cur, sizeof(np->dev_name)); 555 cur = delim; 556 } 557 cur++; 558 559 if (*cur != '@') { 560 /* dst port */ 561 if ((delim = strchr(cur, '@')) == NULL) 562 goto parse_failed; 563 *delim = 0; 564 if (*cur == ' ' || *cur == '\t') 565 np_info(np, "warning: whitespace is not allowed\n"); 566 if (kstrtou16(cur, 10, &np->remote_port)) 567 goto parse_failed; 568 cur = delim; 569 } 570 cur++; 571 572 /* dst ip */ 573 if ((delim = strchr(cur, '/')) == NULL) 574 goto parse_failed; 575 *delim = 0; 576 ipv6 = netpoll_parse_ip_addr(cur, &np->remote_ip); 577 if (ipv6 < 0) 578 goto parse_failed; 579 else if (ipversion_set && np->ipv6 != (bool)ipv6) 580 goto parse_failed; 581 else 582 np->ipv6 = (bool)ipv6; 583 cur = delim + 1; 584 585 if (*cur != 0) { 586 /* MAC address */ 587 if (!mac_pton(cur, np->remote_mac)) 588 goto parse_failed; 589 } 590 591 netpoll_print_options(np); 592 593 return 0; 594 595 parse_failed: 596 np_info(np, "couldn't parse config at '%s'!\n", cur); 597 return -1; 598 } 599 EXPORT_SYMBOL(netpoll_parse_options); 600 601 int __netpoll_setup(struct netpoll *np, struct net_device *ndev) 602 { 603 struct netpoll_info *npinfo; 604 const struct net_device_ops *ops; 605 int err; 606 607 np->dev = ndev; 608 strlcpy(np->dev_name, ndev->name, IFNAMSIZ); 609 INIT_WORK(&np->cleanup_work, netpoll_async_cleanup); 610 611 if ((ndev->priv_flags & IFF_DISABLE_NETPOLL) || 612 !ndev->netdev_ops->ndo_poll_controller) { 613 np_err(np, "%s doesn't support polling, aborting\n", 614 np->dev_name); 615 err = -ENOTSUPP; 616 goto out; 617 } 618 619 if (!ndev->npinfo) { 620 npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL); 621 if (!npinfo) { 622 err = -ENOMEM; 623 goto out; 624 } 625 626 sema_init(&npinfo->dev_lock, 1); 627 skb_queue_head_init(&npinfo->txq); 628 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process); 629 630 atomic_set(&npinfo->refcnt, 1); 631 632 ops = np->dev->netdev_ops; 633 if (ops->ndo_netpoll_setup) { 634 err = ops->ndo_netpoll_setup(ndev, npinfo); 635 if (err) 636 goto free_npinfo; 637 } 638 } else { 639 npinfo = rtnl_dereference(ndev->npinfo); 640 atomic_inc(&npinfo->refcnt); 641 } 642 643 npinfo->netpoll = np; 644 645 /* last thing to do is link it to the net device structure */ 646 rcu_assign_pointer(ndev->npinfo, npinfo); 647 648 return 0; 649 650 free_npinfo: 651 kfree(npinfo); 652 out: 653 return err; 654 } 655 EXPORT_SYMBOL_GPL(__netpoll_setup); 656 657 int netpoll_setup(struct netpoll *np) 658 { 659 struct net_device *ndev = NULL; 660 struct in_device *in_dev; 661 int err; 662 663 rtnl_lock(); 664 if (np->dev_name) { 665 struct net *net = current->nsproxy->net_ns; 666 ndev = __dev_get_by_name(net, np->dev_name); 667 } 668 if (!ndev) { 669 np_err(np, "%s doesn't exist, aborting\n", np->dev_name); 670 err = -ENODEV; 671 goto unlock; 672 } 673 dev_hold(ndev); 674 675 if (netdev_master_upper_dev_get(ndev)) { 676 np_err(np, "%s is a slave device, aborting\n", np->dev_name); 677 err = -EBUSY; 678 goto put; 679 } 680 681 if (!netif_running(ndev)) { 682 unsigned long atmost, atleast; 683 684 np_info(np, "device %s not up yet, forcing it\n", np->dev_name); 685 686 err = dev_open(ndev); 687 688 if (err) { 689 np_err(np, "failed to open %s\n", ndev->name); 690 goto put; 691 } 692 693 rtnl_unlock(); 694 atleast = jiffies + HZ/10; 695 atmost = jiffies + carrier_timeout * HZ; 696 while (!netif_carrier_ok(ndev)) { 697 if (time_after(jiffies, atmost)) { 698 np_notice(np, "timeout waiting for carrier\n"); 699 break; 700 } 701 msleep(1); 702 } 703 704 /* If carrier appears to come up instantly, we don't 705 * trust it and pause so that we don't pump all our 706 * queued console messages into the bitbucket. 707 */ 708 709 if (time_before(jiffies, atleast)) { 710 np_notice(np, "carrier detect appears untrustworthy, waiting 4 seconds\n"); 711 msleep(4000); 712 } 713 rtnl_lock(); 714 } 715 716 if (!np->local_ip.ip) { 717 if (!np->ipv6) { 718 in_dev = __in_dev_get_rtnl(ndev); 719 720 if (!in_dev || !in_dev->ifa_list) { 721 np_err(np, "no IP address for %s, aborting\n", 722 np->dev_name); 723 err = -EDESTADDRREQ; 724 goto put; 725 } 726 727 np->local_ip.ip = in_dev->ifa_list->ifa_local; 728 np_info(np, "local IP %pI4\n", &np->local_ip.ip); 729 } else { 730 #if IS_ENABLED(CONFIG_IPV6) 731 struct inet6_dev *idev; 732 733 err = -EDESTADDRREQ; 734 idev = __in6_dev_get(ndev); 735 if (idev) { 736 struct inet6_ifaddr *ifp; 737 738 read_lock_bh(&idev->lock); 739 list_for_each_entry(ifp, &idev->addr_list, if_list) { 740 if (ipv6_addr_type(&ifp->addr) & IPV6_ADDR_LINKLOCAL) 741 continue; 742 np->local_ip.in6 = ifp->addr; 743 err = 0; 744 break; 745 } 746 read_unlock_bh(&idev->lock); 747 } 748 if (err) { 749 np_err(np, "no IPv6 address for %s, aborting\n", 750 np->dev_name); 751 goto put; 752 } else 753 np_info(np, "local IPv6 %pI6c\n", &np->local_ip.in6); 754 #else 755 np_err(np, "IPv6 is not supported %s, aborting\n", 756 np->dev_name); 757 err = -EINVAL; 758 goto put; 759 #endif 760 } 761 } 762 763 /* fill up the skb queue */ 764 refill_skbs(); 765 766 err = __netpoll_setup(np, ndev); 767 if (err) 768 goto put; 769 770 rtnl_unlock(); 771 return 0; 772 773 put: 774 dev_put(ndev); 775 unlock: 776 rtnl_unlock(); 777 return err; 778 } 779 EXPORT_SYMBOL(netpoll_setup); 780 781 static int __init netpoll_init(void) 782 { 783 skb_queue_head_init(&skb_pool); 784 return 0; 785 } 786 core_initcall(netpoll_init); 787 788 static void rcu_cleanup_netpoll_info(struct rcu_head *rcu_head) 789 { 790 struct netpoll_info *npinfo = 791 container_of(rcu_head, struct netpoll_info, rcu); 792 793 skb_queue_purge(&npinfo->txq); 794 795 /* we can't call cancel_delayed_work_sync here, as we are in softirq */ 796 cancel_delayed_work(&npinfo->tx_work); 797 798 /* clean after last, unfinished work */ 799 __skb_queue_purge(&npinfo->txq); 800 /* now cancel it again */ 801 cancel_delayed_work(&npinfo->tx_work); 802 kfree(npinfo); 803 } 804 805 void __netpoll_cleanup(struct netpoll *np) 806 { 807 struct netpoll_info *npinfo; 808 809 /* rtnl_dereference would be preferable here but 810 * rcu_cleanup_netpoll path can put us in here safely without 811 * holding the rtnl, so plain rcu_dereference it is 812 */ 813 npinfo = rtnl_dereference(np->dev->npinfo); 814 if (!npinfo) 815 return; 816 817 synchronize_srcu(&netpoll_srcu); 818 819 if (atomic_dec_and_test(&npinfo->refcnt)) { 820 const struct net_device_ops *ops; 821 822 ops = np->dev->netdev_ops; 823 if (ops->ndo_netpoll_cleanup) 824 ops->ndo_netpoll_cleanup(np->dev); 825 826 RCU_INIT_POINTER(np->dev->npinfo, NULL); 827 call_rcu_bh(&npinfo->rcu, rcu_cleanup_netpoll_info); 828 } else 829 RCU_INIT_POINTER(np->dev->npinfo, NULL); 830 } 831 EXPORT_SYMBOL_GPL(__netpoll_cleanup); 832 833 static void netpoll_async_cleanup(struct work_struct *work) 834 { 835 struct netpoll *np = container_of(work, struct netpoll, cleanup_work); 836 837 rtnl_lock(); 838 __netpoll_cleanup(np); 839 rtnl_unlock(); 840 kfree(np); 841 } 842 843 void __netpoll_free_async(struct netpoll *np) 844 { 845 schedule_work(&np->cleanup_work); 846 } 847 EXPORT_SYMBOL_GPL(__netpoll_free_async); 848 849 void netpoll_cleanup(struct netpoll *np) 850 { 851 rtnl_lock(); 852 if (!np->dev) 853 goto out; 854 __netpoll_cleanup(np); 855 dev_put(np->dev); 856 np->dev = NULL; 857 out: 858 rtnl_unlock(); 859 } 860 EXPORT_SYMBOL(netpoll_cleanup); 861