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 void poll_one_napi(struct napi_struct *napi) 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; 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 return; 160 161 /* We explicilty pass the polling call a budget of 0 to 162 * indicate that we are clearing the Tx path only. 163 */ 164 work = napi->poll(napi, 0); 165 WARN_ONCE(work, "%pF exceeded budget in poll\n", napi->poll); 166 trace_napi_poll(napi); 167 168 clear_bit(NAPI_STATE_NPSVC, &napi->state); 169 } 170 171 static void poll_napi(struct net_device *dev) 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 poll_one_napi(napi); 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); 188 189 /* Don't do any rx activity if the dev_lock mutex is held 190 * the dev_open/close paths use this to block netpoll activity 191 * while changing device state 192 */ 193 if (down_trylock(&ni->dev_lock)) 194 return; 195 196 if (!netif_running(dev)) { 197 up(&ni->dev_lock); 198 return; 199 } 200 201 ops = dev->netdev_ops; 202 if (!ops->ndo_poll_controller) { 203 up(&ni->dev_lock); 204 return; 205 } 206 207 /* Process pending work on NIC */ 208 ops->ndo_poll_controller(dev); 209 210 poll_napi(dev); 211 212 up(&ni->dev_lock); 213 214 zap_completion_queue(); 215 } 216 217 void netpoll_poll_disable(struct net_device *dev) 218 { 219 struct netpoll_info *ni; 220 int idx; 221 might_sleep(); 222 idx = srcu_read_lock(&netpoll_srcu); 223 ni = srcu_dereference(dev->npinfo, &netpoll_srcu); 224 if (ni) 225 down(&ni->dev_lock); 226 srcu_read_unlock(&netpoll_srcu, idx); 227 } 228 EXPORT_SYMBOL(netpoll_poll_disable); 229 230 void netpoll_poll_enable(struct net_device *dev) 231 { 232 struct netpoll_info *ni; 233 rcu_read_lock(); 234 ni = rcu_dereference(dev->npinfo); 235 if (ni) 236 up(&ni->dev_lock); 237 rcu_read_unlock(); 238 } 239 EXPORT_SYMBOL(netpoll_poll_enable); 240 241 static void refill_skbs(void) 242 { 243 struct sk_buff *skb; 244 unsigned long flags; 245 246 spin_lock_irqsave(&skb_pool.lock, flags); 247 while (skb_pool.qlen < MAX_SKBS) { 248 skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC); 249 if (!skb) 250 break; 251 252 __skb_queue_tail(&skb_pool, skb); 253 } 254 spin_unlock_irqrestore(&skb_pool.lock, flags); 255 } 256 257 static void zap_completion_queue(void) 258 { 259 unsigned long flags; 260 struct softnet_data *sd = &get_cpu_var(softnet_data); 261 262 if (sd->completion_queue) { 263 struct sk_buff *clist; 264 265 local_irq_save(flags); 266 clist = sd->completion_queue; 267 sd->completion_queue = NULL; 268 local_irq_restore(flags); 269 270 while (clist != NULL) { 271 struct sk_buff *skb = clist; 272 clist = clist->next; 273 if (!skb_irq_freeable(skb)) { 274 atomic_inc(&skb->users); 275 dev_kfree_skb_any(skb); /* put this one back */ 276 } else { 277 __kfree_skb(skb); 278 } 279 } 280 } 281 282 put_cpu_var(softnet_data); 283 } 284 285 static struct sk_buff *find_skb(struct netpoll *np, int len, int reserve) 286 { 287 int count = 0; 288 struct sk_buff *skb; 289 290 zap_completion_queue(); 291 refill_skbs(); 292 repeat: 293 294 skb = alloc_skb(len, GFP_ATOMIC); 295 if (!skb) 296 skb = skb_dequeue(&skb_pool); 297 298 if (!skb) { 299 if (++count < 10) { 300 netpoll_poll_dev(np->dev); 301 goto repeat; 302 } 303 return NULL; 304 } 305 306 atomic_set(&skb->users, 1); 307 skb_reserve(skb, reserve); 308 return skb; 309 } 310 311 static int netpoll_owner_active(struct net_device *dev) 312 { 313 struct napi_struct *napi; 314 315 list_for_each_entry(napi, &dev->napi_list, dev_list) { 316 if (napi->poll_owner == smp_processor_id()) 317 return 1; 318 } 319 return 0; 320 } 321 322 /* call with IRQ disabled */ 323 void netpoll_send_skb_on_dev(struct netpoll *np, struct sk_buff *skb, 324 struct net_device *dev) 325 { 326 int status = NETDEV_TX_BUSY; 327 unsigned long tries; 328 /* It is up to the caller to keep npinfo alive. */ 329 struct netpoll_info *npinfo; 330 331 WARN_ON_ONCE(!irqs_disabled()); 332 333 npinfo = rcu_dereference_bh(np->dev->npinfo); 334 if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) { 335 dev_kfree_skb_irq(skb); 336 return; 337 } 338 339 /* don't get messages out of order, and no recursion */ 340 if (skb_queue_len(&npinfo->txq) == 0 && !netpoll_owner_active(dev)) { 341 struct netdev_queue *txq; 342 343 txq = netdev_pick_tx(dev, skb, NULL); 344 345 /* try until next clock tick */ 346 for (tries = jiffies_to_usecs(1)/USEC_PER_POLL; 347 tries > 0; --tries) { 348 if (HARD_TX_TRYLOCK(dev, txq)) { 349 if (!netif_xmit_stopped(txq)) 350 status = netpoll_start_xmit(skb, dev, txq); 351 352 HARD_TX_UNLOCK(dev, txq); 353 354 if (status == NETDEV_TX_OK) 355 break; 356 357 } 358 359 /* tickle device maybe there is some cleanup */ 360 netpoll_poll_dev(np->dev); 361 362 udelay(USEC_PER_POLL); 363 } 364 365 WARN_ONCE(!irqs_disabled(), 366 "netpoll_send_skb_on_dev(): %s enabled interrupts in poll (%pF)\n", 367 dev->name, dev->netdev_ops->ndo_start_xmit); 368 369 } 370 371 if (status != NETDEV_TX_OK) { 372 skb_queue_tail(&npinfo->txq, skb); 373 schedule_delayed_work(&npinfo->tx_work,0); 374 } 375 } 376 EXPORT_SYMBOL(netpoll_send_skb_on_dev); 377 378 void netpoll_send_udp(struct netpoll *np, const char *msg, int len) 379 { 380 int total_len, ip_len, udp_len; 381 struct sk_buff *skb; 382 struct udphdr *udph; 383 struct iphdr *iph; 384 struct ethhdr *eth; 385 static atomic_t ip_ident; 386 struct ipv6hdr *ip6h; 387 388 WARN_ON_ONCE(!irqs_disabled()); 389 390 udp_len = len + sizeof(*udph); 391 if (np->ipv6) 392 ip_len = udp_len + sizeof(*ip6h); 393 else 394 ip_len = udp_len + sizeof(*iph); 395 396 total_len = ip_len + LL_RESERVED_SPACE(np->dev); 397 398 skb = find_skb(np, total_len + np->dev->needed_tailroom, 399 total_len - len); 400 if (!skb) 401 return; 402 403 skb_copy_to_linear_data(skb, msg, len); 404 skb_put(skb, len); 405 406 skb_push(skb, sizeof(*udph)); 407 skb_reset_transport_header(skb); 408 udph = udp_hdr(skb); 409 udph->source = htons(np->local_port); 410 udph->dest = htons(np->remote_port); 411 udph->len = htons(udp_len); 412 413 if (np->ipv6) { 414 udph->check = 0; 415 udph->check = csum_ipv6_magic(&np->local_ip.in6, 416 &np->remote_ip.in6, 417 udp_len, IPPROTO_UDP, 418 csum_partial(udph, udp_len, 0)); 419 if (udph->check == 0) 420 udph->check = CSUM_MANGLED_0; 421 422 skb_push(skb, sizeof(*ip6h)); 423 skb_reset_network_header(skb); 424 ip6h = ipv6_hdr(skb); 425 426 /* ip6h->version = 6; ip6h->priority = 0; */ 427 put_unaligned(0x60, (unsigned char *)ip6h); 428 ip6h->flow_lbl[0] = 0; 429 ip6h->flow_lbl[1] = 0; 430 ip6h->flow_lbl[2] = 0; 431 432 ip6h->payload_len = htons(sizeof(struct udphdr) + len); 433 ip6h->nexthdr = IPPROTO_UDP; 434 ip6h->hop_limit = 32; 435 ip6h->saddr = np->local_ip.in6; 436 ip6h->daddr = np->remote_ip.in6; 437 438 eth = (struct ethhdr *) skb_push(skb, ETH_HLEN); 439 skb_reset_mac_header(skb); 440 skb->protocol = eth->h_proto = htons(ETH_P_IPV6); 441 } else { 442 udph->check = 0; 443 udph->check = csum_tcpudp_magic(np->local_ip.ip, 444 np->remote_ip.ip, 445 udp_len, IPPROTO_UDP, 446 csum_partial(udph, udp_len, 0)); 447 if (udph->check == 0) 448 udph->check = CSUM_MANGLED_0; 449 450 skb_push(skb, sizeof(*iph)); 451 skb_reset_network_header(skb); 452 iph = ip_hdr(skb); 453 454 /* iph->version = 4; iph->ihl = 5; */ 455 put_unaligned(0x45, (unsigned char *)iph); 456 iph->tos = 0; 457 put_unaligned(htons(ip_len), &(iph->tot_len)); 458 iph->id = htons(atomic_inc_return(&ip_ident)); 459 iph->frag_off = 0; 460 iph->ttl = 64; 461 iph->protocol = IPPROTO_UDP; 462 iph->check = 0; 463 put_unaligned(np->local_ip.ip, &(iph->saddr)); 464 put_unaligned(np->remote_ip.ip, &(iph->daddr)); 465 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); 466 467 eth = (struct ethhdr *) skb_push(skb, ETH_HLEN); 468 skb_reset_mac_header(skb); 469 skb->protocol = eth->h_proto = htons(ETH_P_IP); 470 } 471 472 ether_addr_copy(eth->h_source, np->dev->dev_addr); 473 ether_addr_copy(eth->h_dest, np->remote_mac); 474 475 skb->dev = np->dev; 476 477 netpoll_send_skb(np, skb); 478 } 479 EXPORT_SYMBOL(netpoll_send_udp); 480 481 void netpoll_print_options(struct netpoll *np) 482 { 483 np_info(np, "local port %d\n", np->local_port); 484 if (np->ipv6) 485 np_info(np, "local IPv6 address %pI6c\n", &np->local_ip.in6); 486 else 487 np_info(np, "local IPv4 address %pI4\n", &np->local_ip.ip); 488 np_info(np, "interface '%s'\n", np->dev_name); 489 np_info(np, "remote port %d\n", np->remote_port); 490 if (np->ipv6) 491 np_info(np, "remote IPv6 address %pI6c\n", &np->remote_ip.in6); 492 else 493 np_info(np, "remote IPv4 address %pI4\n", &np->remote_ip.ip); 494 np_info(np, "remote ethernet address %pM\n", np->remote_mac); 495 } 496 EXPORT_SYMBOL(netpoll_print_options); 497 498 static int netpoll_parse_ip_addr(const char *str, union inet_addr *addr) 499 { 500 const char *end; 501 502 if (!strchr(str, ':') && 503 in4_pton(str, -1, (void *)addr, -1, &end) > 0) { 504 if (!*end) 505 return 0; 506 } 507 if (in6_pton(str, -1, addr->in6.s6_addr, -1, &end) > 0) { 508 #if IS_ENABLED(CONFIG_IPV6) 509 if (!*end) 510 return 1; 511 #else 512 return -1; 513 #endif 514 } 515 return -1; 516 } 517 518 int netpoll_parse_options(struct netpoll *np, char *opt) 519 { 520 char *cur=opt, *delim; 521 int ipv6; 522 bool ipversion_set = false; 523 524 if (*cur != '@') { 525 if ((delim = strchr(cur, '@')) == NULL) 526 goto parse_failed; 527 *delim = 0; 528 if (kstrtou16(cur, 10, &np->local_port)) 529 goto parse_failed; 530 cur = delim; 531 } 532 cur++; 533 534 if (*cur != '/') { 535 ipversion_set = true; 536 if ((delim = strchr(cur, '/')) == NULL) 537 goto parse_failed; 538 *delim = 0; 539 ipv6 = netpoll_parse_ip_addr(cur, &np->local_ip); 540 if (ipv6 < 0) 541 goto parse_failed; 542 else 543 np->ipv6 = (bool)ipv6; 544 cur = delim; 545 } 546 cur++; 547 548 if (*cur != ',') { 549 /* parse out dev name */ 550 if ((delim = strchr(cur, ',')) == NULL) 551 goto parse_failed; 552 *delim = 0; 553 strlcpy(np->dev_name, cur, sizeof(np->dev_name)); 554 cur = delim; 555 } 556 cur++; 557 558 if (*cur != '@') { 559 /* dst port */ 560 if ((delim = strchr(cur, '@')) == NULL) 561 goto parse_failed; 562 *delim = 0; 563 if (*cur == ' ' || *cur == '\t') 564 np_info(np, "warning: whitespace is not allowed\n"); 565 if (kstrtou16(cur, 10, &np->remote_port)) 566 goto parse_failed; 567 cur = delim; 568 } 569 cur++; 570 571 /* dst ip */ 572 if ((delim = strchr(cur, '/')) == NULL) 573 goto parse_failed; 574 *delim = 0; 575 ipv6 = netpoll_parse_ip_addr(cur, &np->remote_ip); 576 if (ipv6 < 0) 577 goto parse_failed; 578 else if (ipversion_set && np->ipv6 != (bool)ipv6) 579 goto parse_failed; 580 else 581 np->ipv6 = (bool)ipv6; 582 cur = delim + 1; 583 584 if (*cur != 0) { 585 /* MAC address */ 586 if (!mac_pton(cur, np->remote_mac)) 587 goto parse_failed; 588 } 589 590 netpoll_print_options(np); 591 592 return 0; 593 594 parse_failed: 595 np_info(np, "couldn't parse config at '%s'!\n", cur); 596 return -1; 597 } 598 EXPORT_SYMBOL(netpoll_parse_options); 599 600 int __netpoll_setup(struct netpoll *np, struct net_device *ndev) 601 { 602 struct netpoll_info *npinfo; 603 const struct net_device_ops *ops; 604 int err; 605 606 np->dev = ndev; 607 strlcpy(np->dev_name, ndev->name, IFNAMSIZ); 608 INIT_WORK(&np->cleanup_work, netpoll_async_cleanup); 609 610 if ((ndev->priv_flags & IFF_DISABLE_NETPOLL) || 611 !ndev->netdev_ops->ndo_poll_controller) { 612 np_err(np, "%s doesn't support polling, aborting\n", 613 np->dev_name); 614 err = -ENOTSUPP; 615 goto out; 616 } 617 618 if (!ndev->npinfo) { 619 npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL); 620 if (!npinfo) { 621 err = -ENOMEM; 622 goto out; 623 } 624 625 sema_init(&npinfo->dev_lock, 1); 626 skb_queue_head_init(&npinfo->txq); 627 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process); 628 629 atomic_set(&npinfo->refcnt, 1); 630 631 ops = np->dev->netdev_ops; 632 if (ops->ndo_netpoll_setup) { 633 err = ops->ndo_netpoll_setup(ndev, npinfo); 634 if (err) 635 goto free_npinfo; 636 } 637 } else { 638 npinfo = rtnl_dereference(ndev->npinfo); 639 atomic_inc(&npinfo->refcnt); 640 } 641 642 npinfo->netpoll = np; 643 644 /* last thing to do is link it to the net device structure */ 645 rcu_assign_pointer(ndev->npinfo, npinfo); 646 647 return 0; 648 649 free_npinfo: 650 kfree(npinfo); 651 out: 652 return err; 653 } 654 EXPORT_SYMBOL_GPL(__netpoll_setup); 655 656 int netpoll_setup(struct netpoll *np) 657 { 658 struct net_device *ndev = NULL; 659 struct in_device *in_dev; 660 int err; 661 662 rtnl_lock(); 663 if (np->dev_name) { 664 struct net *net = current->nsproxy->net_ns; 665 ndev = __dev_get_by_name(net, np->dev_name); 666 } 667 if (!ndev) { 668 np_err(np, "%s doesn't exist, aborting\n", np->dev_name); 669 err = -ENODEV; 670 goto unlock; 671 } 672 dev_hold(ndev); 673 674 if (netdev_master_upper_dev_get(ndev)) { 675 np_err(np, "%s is a slave device, aborting\n", np->dev_name); 676 err = -EBUSY; 677 goto put; 678 } 679 680 if (!netif_running(ndev)) { 681 unsigned long atmost, atleast; 682 683 np_info(np, "device %s not up yet, forcing it\n", np->dev_name); 684 685 err = dev_open(ndev); 686 687 if (err) { 688 np_err(np, "failed to open %s\n", ndev->name); 689 goto put; 690 } 691 692 rtnl_unlock(); 693 atleast = jiffies + HZ/10; 694 atmost = jiffies + carrier_timeout * HZ; 695 while (!netif_carrier_ok(ndev)) { 696 if (time_after(jiffies, atmost)) { 697 np_notice(np, "timeout waiting for carrier\n"); 698 break; 699 } 700 msleep(1); 701 } 702 703 /* If carrier appears to come up instantly, we don't 704 * trust it and pause so that we don't pump all our 705 * queued console messages into the bitbucket. 706 */ 707 708 if (time_before(jiffies, atleast)) { 709 np_notice(np, "carrier detect appears untrustworthy, waiting 4 seconds\n"); 710 msleep(4000); 711 } 712 rtnl_lock(); 713 } 714 715 if (!np->local_ip.ip) { 716 if (!np->ipv6) { 717 in_dev = __in_dev_get_rtnl(ndev); 718 719 if (!in_dev || !in_dev->ifa_list) { 720 np_err(np, "no IP address for %s, aborting\n", 721 np->dev_name); 722 err = -EDESTADDRREQ; 723 goto put; 724 } 725 726 np->local_ip.ip = in_dev->ifa_list->ifa_local; 727 np_info(np, "local IP %pI4\n", &np->local_ip.ip); 728 } else { 729 #if IS_ENABLED(CONFIG_IPV6) 730 struct inet6_dev *idev; 731 732 err = -EDESTADDRREQ; 733 idev = __in6_dev_get(ndev); 734 if (idev) { 735 struct inet6_ifaddr *ifp; 736 737 read_lock_bh(&idev->lock); 738 list_for_each_entry(ifp, &idev->addr_list, if_list) { 739 if (ipv6_addr_type(&ifp->addr) & IPV6_ADDR_LINKLOCAL) 740 continue; 741 np->local_ip.in6 = ifp->addr; 742 err = 0; 743 break; 744 } 745 read_unlock_bh(&idev->lock); 746 } 747 if (err) { 748 np_err(np, "no IPv6 address for %s, aborting\n", 749 np->dev_name); 750 goto put; 751 } else 752 np_info(np, "local IPv6 %pI6c\n", &np->local_ip.in6); 753 #else 754 np_err(np, "IPv6 is not supported %s, aborting\n", 755 np->dev_name); 756 err = -EINVAL; 757 goto put; 758 #endif 759 } 760 } 761 762 /* fill up the skb queue */ 763 refill_skbs(); 764 765 err = __netpoll_setup(np, ndev); 766 if (err) 767 goto put; 768 769 rtnl_unlock(); 770 return 0; 771 772 put: 773 dev_put(ndev); 774 unlock: 775 rtnl_unlock(); 776 return err; 777 } 778 EXPORT_SYMBOL(netpoll_setup); 779 780 static int __init netpoll_init(void) 781 { 782 skb_queue_head_init(&skb_pool); 783 return 0; 784 } 785 core_initcall(netpoll_init); 786 787 static void rcu_cleanup_netpoll_info(struct rcu_head *rcu_head) 788 { 789 struct netpoll_info *npinfo = 790 container_of(rcu_head, struct netpoll_info, rcu); 791 792 skb_queue_purge(&npinfo->txq); 793 794 /* we can't call cancel_delayed_work_sync here, as we are in softirq */ 795 cancel_delayed_work(&npinfo->tx_work); 796 797 /* clean after last, unfinished work */ 798 __skb_queue_purge(&npinfo->txq); 799 /* now cancel it again */ 800 cancel_delayed_work(&npinfo->tx_work); 801 kfree(npinfo); 802 } 803 804 void __netpoll_cleanup(struct netpoll *np) 805 { 806 struct netpoll_info *npinfo; 807 808 /* rtnl_dereference would be preferable here but 809 * rcu_cleanup_netpoll path can put us in here safely without 810 * holding the rtnl, so plain rcu_dereference it is 811 */ 812 npinfo = rtnl_dereference(np->dev->npinfo); 813 if (!npinfo) 814 return; 815 816 synchronize_srcu(&netpoll_srcu); 817 818 if (atomic_dec_and_test(&npinfo->refcnt)) { 819 const struct net_device_ops *ops; 820 821 ops = np->dev->netdev_ops; 822 if (ops->ndo_netpoll_cleanup) 823 ops->ndo_netpoll_cleanup(np->dev); 824 825 RCU_INIT_POINTER(np->dev->npinfo, NULL); 826 call_rcu_bh(&npinfo->rcu, rcu_cleanup_netpoll_info); 827 } else 828 RCU_INIT_POINTER(np->dev->npinfo, NULL); 829 } 830 EXPORT_SYMBOL_GPL(__netpoll_cleanup); 831 832 static void netpoll_async_cleanup(struct work_struct *work) 833 { 834 struct netpoll *np = container_of(work, struct netpoll, cleanup_work); 835 836 rtnl_lock(); 837 __netpoll_cleanup(np); 838 rtnl_unlock(); 839 kfree(np); 840 } 841 842 void __netpoll_free_async(struct netpoll *np) 843 { 844 schedule_work(&np->cleanup_work); 845 } 846 EXPORT_SYMBOL_GPL(__netpoll_free_async); 847 848 void netpoll_cleanup(struct netpoll *np) 849 { 850 rtnl_lock(); 851 if (!np->dev) 852 goto out; 853 __netpoll_cleanup(np); 854 dev_put(np->dev); 855 np->dev = NULL; 856 out: 857 rtnl_unlock(); 858 } 859 EXPORT_SYMBOL(netpoll_cleanup); 860