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 const struct net_device_ops *ops = dev->netdev_ops; 76 int status = NETDEV_TX_OK; 77 netdev_features_t features; 78 79 features = netif_skb_features(skb); 80 81 if (vlan_tx_tag_present(skb) && 82 !vlan_hw_offload_capable(features, skb->vlan_proto)) { 83 skb = __vlan_put_tag(skb, skb->vlan_proto, 84 vlan_tx_tag_get(skb)); 85 if (unlikely(!skb)) { 86 /* This is actually a packet drop, but we 87 * don't want the code that calls this 88 * function to try and operate on a NULL skb. 89 */ 90 goto out; 91 } 92 skb->vlan_tci = 0; 93 } 94 95 status = ops->ndo_start_xmit(skb, dev); 96 if (status == NETDEV_TX_OK) 97 txq_trans_update(txq); 98 99 out: 100 return status; 101 } 102 103 static void queue_process(struct work_struct *work) 104 { 105 struct netpoll_info *npinfo = 106 container_of(work, struct netpoll_info, tx_work.work); 107 struct sk_buff *skb; 108 unsigned long flags; 109 110 while ((skb = skb_dequeue(&npinfo->txq))) { 111 struct net_device *dev = skb->dev; 112 struct netdev_queue *txq; 113 114 if (!netif_device_present(dev) || !netif_running(dev)) { 115 kfree_skb(skb); 116 continue; 117 } 118 119 txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb)); 120 121 local_irq_save(flags); 122 HARD_TX_LOCK(dev, txq, smp_processor_id()); 123 if (netif_xmit_frozen_or_stopped(txq) || 124 netpoll_start_xmit(skb, dev, txq) != NETDEV_TX_OK) { 125 skb_queue_head(&npinfo->txq, skb); 126 HARD_TX_UNLOCK(dev, txq); 127 local_irq_restore(flags); 128 129 schedule_delayed_work(&npinfo->tx_work, HZ/10); 130 return; 131 } 132 HARD_TX_UNLOCK(dev, txq); 133 local_irq_restore(flags); 134 } 135 } 136 137 /* 138 * Check whether delayed processing was scheduled for our NIC. If so, 139 * we attempt to grab the poll lock and use ->poll() to pump the card. 140 * If this fails, either we've recursed in ->poll() or it's already 141 * running on another CPU. 142 * 143 * Note: we don't mask interrupts with this lock because we're using 144 * trylock here and interrupts are already disabled in the softirq 145 * case. Further, we test the poll_owner to avoid recursion on UP 146 * systems where the lock doesn't exist. 147 */ 148 static int poll_one_napi(struct napi_struct *napi, int budget) 149 { 150 int work; 151 152 /* net_rx_action's ->poll() invocations and our's are 153 * synchronized by this test which is only made while 154 * holding the napi->poll_lock. 155 */ 156 if (!test_bit(NAPI_STATE_SCHED, &napi->state)) 157 return budget; 158 159 set_bit(NAPI_STATE_NPSVC, &napi->state); 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 return budget - work; 168 } 169 170 static void poll_napi(struct net_device *dev, int budget) 171 { 172 struct napi_struct *napi; 173 174 list_for_each_entry(napi, &dev->napi_list, dev_list) { 175 if (napi->poll_owner != smp_processor_id() && 176 spin_trylock(&napi->poll_lock)) { 177 budget = poll_one_napi(napi, budget); 178 spin_unlock(&napi->poll_lock); 179 } 180 } 181 } 182 183 static void netpoll_poll_dev(struct net_device *dev) 184 { 185 const struct net_device_ops *ops; 186 struct netpoll_info *ni = rcu_dereference_bh(dev->npinfo); 187 int budget = 0; 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, budget); 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 udp_len = len + sizeof(*udph); 389 if (np->ipv6) 390 ip_len = udp_len + sizeof(*ip6h); 391 else 392 ip_len = udp_len + sizeof(*iph); 393 394 total_len = ip_len + LL_RESERVED_SPACE(np->dev); 395 396 skb = find_skb(np, total_len + np->dev->needed_tailroom, 397 total_len - len); 398 if (!skb) 399 return; 400 401 skb_copy_to_linear_data(skb, msg, len); 402 skb_put(skb, len); 403 404 skb_push(skb, sizeof(*udph)); 405 skb_reset_transport_header(skb); 406 udph = udp_hdr(skb); 407 udph->source = htons(np->local_port); 408 udph->dest = htons(np->remote_port); 409 udph->len = htons(udp_len); 410 411 if (np->ipv6) { 412 udph->check = 0; 413 udph->check = csum_ipv6_magic(&np->local_ip.in6, 414 &np->remote_ip.in6, 415 udp_len, IPPROTO_UDP, 416 csum_partial(udph, udp_len, 0)); 417 if (udph->check == 0) 418 udph->check = CSUM_MANGLED_0; 419 420 skb_push(skb, sizeof(*ip6h)); 421 skb_reset_network_header(skb); 422 ip6h = ipv6_hdr(skb); 423 424 /* ip6h->version = 6; ip6h->priority = 0; */ 425 put_unaligned(0x60, (unsigned char *)ip6h); 426 ip6h->flow_lbl[0] = 0; 427 ip6h->flow_lbl[1] = 0; 428 ip6h->flow_lbl[2] = 0; 429 430 ip6h->payload_len = htons(sizeof(struct udphdr) + len); 431 ip6h->nexthdr = IPPROTO_UDP; 432 ip6h->hop_limit = 32; 433 ip6h->saddr = np->local_ip.in6; 434 ip6h->daddr = np->remote_ip.in6; 435 436 eth = (struct ethhdr *) skb_push(skb, ETH_HLEN); 437 skb_reset_mac_header(skb); 438 skb->protocol = eth->h_proto = htons(ETH_P_IPV6); 439 } else { 440 udph->check = 0; 441 udph->check = csum_tcpudp_magic(np->local_ip.ip, 442 np->remote_ip.ip, 443 udp_len, IPPROTO_UDP, 444 csum_partial(udph, udp_len, 0)); 445 if (udph->check == 0) 446 udph->check = CSUM_MANGLED_0; 447 448 skb_push(skb, sizeof(*iph)); 449 skb_reset_network_header(skb); 450 iph = ip_hdr(skb); 451 452 /* iph->version = 4; iph->ihl = 5; */ 453 put_unaligned(0x45, (unsigned char *)iph); 454 iph->tos = 0; 455 put_unaligned(htons(ip_len), &(iph->tot_len)); 456 iph->id = htons(atomic_inc_return(&ip_ident)); 457 iph->frag_off = 0; 458 iph->ttl = 64; 459 iph->protocol = IPPROTO_UDP; 460 iph->check = 0; 461 put_unaligned(np->local_ip.ip, &(iph->saddr)); 462 put_unaligned(np->remote_ip.ip, &(iph->daddr)); 463 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); 464 465 eth = (struct ethhdr *) skb_push(skb, ETH_HLEN); 466 skb_reset_mac_header(skb); 467 skb->protocol = eth->h_proto = htons(ETH_P_IP); 468 } 469 470 ether_addr_copy(eth->h_source, np->dev->dev_addr); 471 ether_addr_copy(eth->h_dest, np->remote_mac); 472 473 skb->dev = np->dev; 474 475 netpoll_send_skb(np, skb); 476 } 477 EXPORT_SYMBOL(netpoll_send_udp); 478 479 void netpoll_print_options(struct netpoll *np) 480 { 481 np_info(np, "local port %d\n", np->local_port); 482 if (np->ipv6) 483 np_info(np, "local IPv6 address %pI6c\n", &np->local_ip.in6); 484 else 485 np_info(np, "local IPv4 address %pI4\n", &np->local_ip.ip); 486 np_info(np, "interface '%s'\n", np->dev_name); 487 np_info(np, "remote port %d\n", np->remote_port); 488 if (np->ipv6) 489 np_info(np, "remote IPv6 address %pI6c\n", &np->remote_ip.in6); 490 else 491 np_info(np, "remote IPv4 address %pI4\n", &np->remote_ip.ip); 492 np_info(np, "remote ethernet address %pM\n", np->remote_mac); 493 } 494 EXPORT_SYMBOL(netpoll_print_options); 495 496 static int netpoll_parse_ip_addr(const char *str, union inet_addr *addr) 497 { 498 const char *end; 499 500 if (!strchr(str, ':') && 501 in4_pton(str, -1, (void *)addr, -1, &end) > 0) { 502 if (!*end) 503 return 0; 504 } 505 if (in6_pton(str, -1, addr->in6.s6_addr, -1, &end) > 0) { 506 #if IS_ENABLED(CONFIG_IPV6) 507 if (!*end) 508 return 1; 509 #else 510 return -1; 511 #endif 512 } 513 return -1; 514 } 515 516 int netpoll_parse_options(struct netpoll *np, char *opt) 517 { 518 char *cur=opt, *delim; 519 int ipv6; 520 bool ipversion_set = false; 521 522 if (*cur != '@') { 523 if ((delim = strchr(cur, '@')) == NULL) 524 goto parse_failed; 525 *delim = 0; 526 if (kstrtou16(cur, 10, &np->local_port)) 527 goto parse_failed; 528 cur = delim; 529 } 530 cur++; 531 532 if (*cur != '/') { 533 ipversion_set = true; 534 if ((delim = strchr(cur, '/')) == NULL) 535 goto parse_failed; 536 *delim = 0; 537 ipv6 = netpoll_parse_ip_addr(cur, &np->local_ip); 538 if (ipv6 < 0) 539 goto parse_failed; 540 else 541 np->ipv6 = (bool)ipv6; 542 cur = delim; 543 } 544 cur++; 545 546 if (*cur != ',') { 547 /* parse out dev name */ 548 if ((delim = strchr(cur, ',')) == NULL) 549 goto parse_failed; 550 *delim = 0; 551 strlcpy(np->dev_name, cur, sizeof(np->dev_name)); 552 cur = delim; 553 } 554 cur++; 555 556 if (*cur != '@') { 557 /* dst port */ 558 if ((delim = strchr(cur, '@')) == NULL) 559 goto parse_failed; 560 *delim = 0; 561 if (*cur == ' ' || *cur == '\t') 562 np_info(np, "warning: whitespace is not allowed\n"); 563 if (kstrtou16(cur, 10, &np->remote_port)) 564 goto parse_failed; 565 cur = delim; 566 } 567 cur++; 568 569 /* dst ip */ 570 if ((delim = strchr(cur, '/')) == NULL) 571 goto parse_failed; 572 *delim = 0; 573 ipv6 = netpoll_parse_ip_addr(cur, &np->remote_ip); 574 if (ipv6 < 0) 575 goto parse_failed; 576 else if (ipversion_set && np->ipv6 != (bool)ipv6) 577 goto parse_failed; 578 else 579 np->ipv6 = (bool)ipv6; 580 cur = delim + 1; 581 582 if (*cur != 0) { 583 /* MAC address */ 584 if (!mac_pton(cur, np->remote_mac)) 585 goto parse_failed; 586 } 587 588 netpoll_print_options(np); 589 590 return 0; 591 592 parse_failed: 593 np_info(np, "couldn't parse config at '%s'!\n", cur); 594 return -1; 595 } 596 EXPORT_SYMBOL(netpoll_parse_options); 597 598 int __netpoll_setup(struct netpoll *np, struct net_device *ndev) 599 { 600 struct netpoll_info *npinfo; 601 const struct net_device_ops *ops; 602 int err; 603 604 np->dev = ndev; 605 strlcpy(np->dev_name, ndev->name, IFNAMSIZ); 606 INIT_WORK(&np->cleanup_work, netpoll_async_cleanup); 607 608 if ((ndev->priv_flags & IFF_DISABLE_NETPOLL) || 609 !ndev->netdev_ops->ndo_poll_controller) { 610 np_err(np, "%s doesn't support polling, aborting\n", 611 np->dev_name); 612 err = -ENOTSUPP; 613 goto out; 614 } 615 616 if (!ndev->npinfo) { 617 npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL); 618 if (!npinfo) { 619 err = -ENOMEM; 620 goto out; 621 } 622 623 sema_init(&npinfo->dev_lock, 1); 624 skb_queue_head_init(&npinfo->txq); 625 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process); 626 627 atomic_set(&npinfo->refcnt, 1); 628 629 ops = np->dev->netdev_ops; 630 if (ops->ndo_netpoll_setup) { 631 err = ops->ndo_netpoll_setup(ndev, npinfo); 632 if (err) 633 goto free_npinfo; 634 } 635 } else { 636 npinfo = rtnl_dereference(ndev->npinfo); 637 atomic_inc(&npinfo->refcnt); 638 } 639 640 npinfo->netpoll = np; 641 642 /* last thing to do is link it to the net device structure */ 643 rcu_assign_pointer(ndev->npinfo, npinfo); 644 645 return 0; 646 647 free_npinfo: 648 kfree(npinfo); 649 out: 650 return err; 651 } 652 EXPORT_SYMBOL_GPL(__netpoll_setup); 653 654 int netpoll_setup(struct netpoll *np) 655 { 656 struct net_device *ndev = NULL; 657 struct in_device *in_dev; 658 int err; 659 660 rtnl_lock(); 661 if (np->dev_name) { 662 struct net *net = current->nsproxy->net_ns; 663 ndev = __dev_get_by_name(net, np->dev_name); 664 } 665 if (!ndev) { 666 np_err(np, "%s doesn't exist, aborting\n", np->dev_name); 667 err = -ENODEV; 668 goto unlock; 669 } 670 dev_hold(ndev); 671 672 if (netdev_master_upper_dev_get(ndev)) { 673 np_err(np, "%s is a slave device, aborting\n", np->dev_name); 674 err = -EBUSY; 675 goto put; 676 } 677 678 if (!netif_running(ndev)) { 679 unsigned long atmost, atleast; 680 681 np_info(np, "device %s not up yet, forcing it\n", np->dev_name); 682 683 err = dev_open(ndev); 684 685 if (err) { 686 np_err(np, "failed to open %s\n", ndev->name); 687 goto put; 688 } 689 690 rtnl_unlock(); 691 atleast = jiffies + HZ/10; 692 atmost = jiffies + carrier_timeout * HZ; 693 while (!netif_carrier_ok(ndev)) { 694 if (time_after(jiffies, atmost)) { 695 np_notice(np, "timeout waiting for carrier\n"); 696 break; 697 } 698 msleep(1); 699 } 700 701 /* If carrier appears to come up instantly, we don't 702 * trust it and pause so that we don't pump all our 703 * queued console messages into the bitbucket. 704 */ 705 706 if (time_before(jiffies, atleast)) { 707 np_notice(np, "carrier detect appears untrustworthy, waiting 4 seconds\n"); 708 msleep(4000); 709 } 710 rtnl_lock(); 711 } 712 713 if (!np->local_ip.ip) { 714 if (!np->ipv6) { 715 in_dev = __in_dev_get_rtnl(ndev); 716 717 if (!in_dev || !in_dev->ifa_list) { 718 np_err(np, "no IP address for %s, aborting\n", 719 np->dev_name); 720 err = -EDESTADDRREQ; 721 goto put; 722 } 723 724 np->local_ip.ip = in_dev->ifa_list->ifa_local; 725 np_info(np, "local IP %pI4\n", &np->local_ip.ip); 726 } else { 727 #if IS_ENABLED(CONFIG_IPV6) 728 struct inet6_dev *idev; 729 730 err = -EDESTADDRREQ; 731 idev = __in6_dev_get(ndev); 732 if (idev) { 733 struct inet6_ifaddr *ifp; 734 735 read_lock_bh(&idev->lock); 736 list_for_each_entry(ifp, &idev->addr_list, if_list) { 737 if (ipv6_addr_type(&ifp->addr) & IPV6_ADDR_LINKLOCAL) 738 continue; 739 np->local_ip.in6 = ifp->addr; 740 err = 0; 741 break; 742 } 743 read_unlock_bh(&idev->lock); 744 } 745 if (err) { 746 np_err(np, "no IPv6 address for %s, aborting\n", 747 np->dev_name); 748 goto put; 749 } else 750 np_info(np, "local IPv6 %pI6c\n", &np->local_ip.in6); 751 #else 752 np_err(np, "IPv6 is not supported %s, aborting\n", 753 np->dev_name); 754 err = -EINVAL; 755 goto put; 756 #endif 757 } 758 } 759 760 /* fill up the skb queue */ 761 refill_skbs(); 762 763 err = __netpoll_setup(np, ndev); 764 if (err) 765 goto put; 766 767 rtnl_unlock(); 768 return 0; 769 770 put: 771 dev_put(ndev); 772 unlock: 773 rtnl_unlock(); 774 return err; 775 } 776 EXPORT_SYMBOL(netpoll_setup); 777 778 static int __init netpoll_init(void) 779 { 780 skb_queue_head_init(&skb_pool); 781 return 0; 782 } 783 core_initcall(netpoll_init); 784 785 static void rcu_cleanup_netpoll_info(struct rcu_head *rcu_head) 786 { 787 struct netpoll_info *npinfo = 788 container_of(rcu_head, struct netpoll_info, rcu); 789 790 skb_queue_purge(&npinfo->txq); 791 792 /* we can't call cancel_delayed_work_sync here, as we are in softirq */ 793 cancel_delayed_work(&npinfo->tx_work); 794 795 /* clean after last, unfinished work */ 796 __skb_queue_purge(&npinfo->txq); 797 /* now cancel it again */ 798 cancel_delayed_work(&npinfo->tx_work); 799 kfree(npinfo); 800 } 801 802 void __netpoll_cleanup(struct netpoll *np) 803 { 804 struct netpoll_info *npinfo; 805 806 /* rtnl_dereference would be preferable here but 807 * rcu_cleanup_netpoll path can put us in here safely without 808 * holding the rtnl, so plain rcu_dereference it is 809 */ 810 npinfo = rtnl_dereference(np->dev->npinfo); 811 if (!npinfo) 812 return; 813 814 synchronize_srcu(&netpoll_srcu); 815 816 if (atomic_dec_and_test(&npinfo->refcnt)) { 817 const struct net_device_ops *ops; 818 819 ops = np->dev->netdev_ops; 820 if (ops->ndo_netpoll_cleanup) 821 ops->ndo_netpoll_cleanup(np->dev); 822 823 RCU_INIT_POINTER(np->dev->npinfo, NULL); 824 call_rcu_bh(&npinfo->rcu, rcu_cleanup_netpoll_info); 825 } else 826 RCU_INIT_POINTER(np->dev->npinfo, NULL); 827 } 828 EXPORT_SYMBOL_GPL(__netpoll_cleanup); 829 830 static void netpoll_async_cleanup(struct work_struct *work) 831 { 832 struct netpoll *np = container_of(work, struct netpoll, cleanup_work); 833 834 rtnl_lock(); 835 __netpoll_cleanup(np); 836 rtnl_unlock(); 837 kfree(np); 838 } 839 840 void __netpoll_free_async(struct netpoll *np) 841 { 842 schedule_work(&np->cleanup_work); 843 } 844 EXPORT_SYMBOL_GPL(__netpoll_free_async); 845 846 void netpoll_cleanup(struct netpoll *np) 847 { 848 rtnl_lock(); 849 if (!np->dev) 850 goto out; 851 __netpoll_cleanup(np); 852 dev_put(np->dev); 853 np->dev = NULL; 854 out: 855 rtnl_unlock(); 856 } 857 EXPORT_SYMBOL(netpoll_cleanup); 858