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 unsigned int q_index; 109 110 if (!netif_device_present(dev) || !netif_running(dev)) { 111 kfree_skb(skb); 112 continue; 113 } 114 115 local_irq_save(flags); 116 /* check if skb->queue_mapping is still valid */ 117 q_index = skb_get_queue_mapping(skb); 118 if (unlikely(q_index >= dev->real_num_tx_queues)) { 119 q_index = q_index % dev->real_num_tx_queues; 120 skb_set_queue_mapping(skb, q_index); 121 } 122 txq = netdev_get_tx_queue(dev, q_index); 123 HARD_TX_LOCK(dev, txq, smp_processor_id()); 124 if (netif_xmit_frozen_or_stopped(txq) || 125 netpoll_start_xmit(skb, dev, txq) != NETDEV_TX_OK) { 126 skb_queue_head(&npinfo->txq, skb); 127 HARD_TX_UNLOCK(dev, txq); 128 local_irq_restore(flags); 129 130 schedule_delayed_work(&npinfo->tx_work, HZ/10); 131 return; 132 } 133 HARD_TX_UNLOCK(dev, txq); 134 local_irq_restore(flags); 135 } 136 } 137 138 /* 139 * Check whether delayed processing was scheduled for our NIC. If so, 140 * we attempt to grab the poll lock and use ->poll() to pump the card. 141 * If this fails, either we've recursed in ->poll() or it's already 142 * running on another CPU. 143 * 144 * Note: we don't mask interrupts with this lock because we're using 145 * trylock here and interrupts are already disabled in the softirq 146 * case. Further, we test the poll_owner to avoid recursion on UP 147 * systems where the lock doesn't exist. 148 */ 149 static void poll_one_napi(struct napi_struct *napi) 150 { 151 int work = 0; 152 153 /* net_rx_action's ->poll() invocations and our's are 154 * synchronized by this test which is only made while 155 * holding the napi->poll_lock. 156 */ 157 if (!test_bit(NAPI_STATE_SCHED, &napi->state)) 158 return; 159 160 /* If we set this bit but see that it has already been set, 161 * that indicates that napi has been disabled and we need 162 * to abort this operation 163 */ 164 if (test_and_set_bit(NAPI_STATE_NPSVC, &napi->state)) 165 return; 166 167 /* We explicilty pass the polling call a budget of 0 to 168 * indicate that we are clearing the Tx path only. 169 */ 170 work = napi->poll(napi, 0); 171 WARN_ONCE(work, "%pF exceeded budget in poll\n", napi->poll); 172 trace_napi_poll(napi, work, 0); 173 174 clear_bit(NAPI_STATE_NPSVC, &napi->state); 175 } 176 177 static void poll_napi(struct net_device *dev) 178 { 179 struct napi_struct *napi; 180 int cpu = smp_processor_id(); 181 182 list_for_each_entry(napi, &dev->napi_list, dev_list) { 183 if (cmpxchg(&napi->poll_owner, -1, cpu) == -1) { 184 poll_one_napi(napi); 185 smp_store_release(&napi->poll_owner, -1); 186 } 187 } 188 } 189 190 void netpoll_poll_dev(struct net_device *dev) 191 { 192 struct netpoll_info *ni = rcu_dereference_bh(dev->npinfo); 193 const struct net_device_ops *ops; 194 195 /* Don't do any rx activity if the dev_lock mutex is held 196 * the dev_open/close paths use this to block netpoll activity 197 * while changing device state 198 */ 199 if (!ni || down_trylock(&ni->dev_lock)) 200 return; 201 202 if (!netif_running(dev)) { 203 up(&ni->dev_lock); 204 return; 205 } 206 207 ops = dev->netdev_ops; 208 if (ops->ndo_poll_controller) 209 ops->ndo_poll_controller(dev); 210 211 poll_napi(dev); 212 213 up(&ni->dev_lock); 214 215 zap_completion_queue(); 216 } 217 EXPORT_SYMBOL(netpoll_poll_dev); 218 219 void netpoll_poll_disable(struct net_device *dev) 220 { 221 struct netpoll_info *ni; 222 int idx; 223 might_sleep(); 224 idx = srcu_read_lock(&netpoll_srcu); 225 ni = srcu_dereference(dev->npinfo, &netpoll_srcu); 226 if (ni) 227 down(&ni->dev_lock); 228 srcu_read_unlock(&netpoll_srcu, idx); 229 } 230 EXPORT_SYMBOL(netpoll_poll_disable); 231 232 void netpoll_poll_enable(struct net_device *dev) 233 { 234 struct netpoll_info *ni; 235 rcu_read_lock(); 236 ni = rcu_dereference(dev->npinfo); 237 if (ni) 238 up(&ni->dev_lock); 239 rcu_read_unlock(); 240 } 241 EXPORT_SYMBOL(netpoll_poll_enable); 242 243 static void refill_skbs(void) 244 { 245 struct sk_buff *skb; 246 unsigned long flags; 247 248 spin_lock_irqsave(&skb_pool.lock, flags); 249 while (skb_pool.qlen < MAX_SKBS) { 250 skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC); 251 if (!skb) 252 break; 253 254 __skb_queue_tail(&skb_pool, skb); 255 } 256 spin_unlock_irqrestore(&skb_pool.lock, flags); 257 } 258 259 static void zap_completion_queue(void) 260 { 261 unsigned long flags; 262 struct softnet_data *sd = &get_cpu_var(softnet_data); 263 264 if (sd->completion_queue) { 265 struct sk_buff *clist; 266 267 local_irq_save(flags); 268 clist = sd->completion_queue; 269 sd->completion_queue = NULL; 270 local_irq_restore(flags); 271 272 while (clist != NULL) { 273 struct sk_buff *skb = clist; 274 clist = clist->next; 275 if (!skb_irq_freeable(skb)) { 276 refcount_set(&skb->users, 1); 277 dev_kfree_skb_any(skb); /* put this one back */ 278 } else { 279 __kfree_skb(skb); 280 } 281 } 282 } 283 284 put_cpu_var(softnet_data); 285 } 286 287 static struct sk_buff *find_skb(struct netpoll *np, int len, int reserve) 288 { 289 int count = 0; 290 struct sk_buff *skb; 291 292 zap_completion_queue(); 293 refill_skbs(); 294 repeat: 295 296 skb = alloc_skb(len, GFP_ATOMIC); 297 if (!skb) 298 skb = skb_dequeue(&skb_pool); 299 300 if (!skb) { 301 if (++count < 10) { 302 netpoll_poll_dev(np->dev); 303 goto repeat; 304 } 305 return NULL; 306 } 307 308 refcount_set(&skb->users, 1); 309 skb_reserve(skb, reserve); 310 return skb; 311 } 312 313 static int netpoll_owner_active(struct net_device *dev) 314 { 315 struct napi_struct *napi; 316 317 list_for_each_entry(napi, &dev->napi_list, dev_list) { 318 if (napi->poll_owner == smp_processor_id()) 319 return 1; 320 } 321 return 0; 322 } 323 324 /* call with IRQ disabled */ 325 void netpoll_send_skb_on_dev(struct netpoll *np, struct sk_buff *skb, 326 struct net_device *dev) 327 { 328 int status = NETDEV_TX_BUSY; 329 unsigned long tries; 330 /* It is up to the caller to keep npinfo alive. */ 331 struct netpoll_info *npinfo; 332 333 lockdep_assert_irqs_disabled(); 334 335 npinfo = rcu_dereference_bh(np->dev->npinfo); 336 if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) { 337 dev_kfree_skb_irq(skb); 338 return; 339 } 340 341 /* don't get messages out of order, and no recursion */ 342 if (skb_queue_len(&npinfo->txq) == 0 && !netpoll_owner_active(dev)) { 343 struct netdev_queue *txq; 344 345 txq = netdev_pick_tx(dev, skb, NULL); 346 347 /* try until next clock tick */ 348 for (tries = jiffies_to_usecs(1)/USEC_PER_POLL; 349 tries > 0; --tries) { 350 if (HARD_TX_TRYLOCK(dev, txq)) { 351 if (!netif_xmit_stopped(txq)) 352 status = netpoll_start_xmit(skb, dev, txq); 353 354 HARD_TX_UNLOCK(dev, txq); 355 356 if (status == NETDEV_TX_OK) 357 break; 358 359 } 360 361 /* tickle device maybe there is some cleanup */ 362 netpoll_poll_dev(np->dev); 363 364 udelay(USEC_PER_POLL); 365 } 366 367 WARN_ONCE(!irqs_disabled(), 368 "netpoll_send_skb_on_dev(): %s enabled interrupts in poll (%pF)\n", 369 dev->name, dev->netdev_ops->ndo_start_xmit); 370 371 } 372 373 if (status != NETDEV_TX_OK) { 374 skb_queue_tail(&npinfo->txq, skb); 375 schedule_delayed_work(&npinfo->tx_work,0); 376 } 377 } 378 EXPORT_SYMBOL(netpoll_send_skb_on_dev); 379 380 void netpoll_send_udp(struct netpoll *np, const char *msg, int len) 381 { 382 int total_len, ip_len, udp_len; 383 struct sk_buff *skb; 384 struct udphdr *udph; 385 struct iphdr *iph; 386 struct ethhdr *eth; 387 static atomic_t ip_ident; 388 struct ipv6hdr *ip6h; 389 390 WARN_ON_ONCE(!irqs_disabled()); 391 392 udp_len = len + sizeof(*udph); 393 if (np->ipv6) 394 ip_len = udp_len + sizeof(*ip6h); 395 else 396 ip_len = udp_len + sizeof(*iph); 397 398 total_len = ip_len + LL_RESERVED_SPACE(np->dev); 399 400 skb = find_skb(np, total_len + np->dev->needed_tailroom, 401 total_len - len); 402 if (!skb) 403 return; 404 405 skb_copy_to_linear_data(skb, msg, len); 406 skb_put(skb, len); 407 408 skb_push(skb, sizeof(*udph)); 409 skb_reset_transport_header(skb); 410 udph = udp_hdr(skb); 411 udph->source = htons(np->local_port); 412 udph->dest = htons(np->remote_port); 413 udph->len = htons(udp_len); 414 415 if (np->ipv6) { 416 udph->check = 0; 417 udph->check = csum_ipv6_magic(&np->local_ip.in6, 418 &np->remote_ip.in6, 419 udp_len, IPPROTO_UDP, 420 csum_partial(udph, udp_len, 0)); 421 if (udph->check == 0) 422 udph->check = CSUM_MANGLED_0; 423 424 skb_push(skb, sizeof(*ip6h)); 425 skb_reset_network_header(skb); 426 ip6h = ipv6_hdr(skb); 427 428 /* ip6h->version = 6; ip6h->priority = 0; */ 429 put_unaligned(0x60, (unsigned char *)ip6h); 430 ip6h->flow_lbl[0] = 0; 431 ip6h->flow_lbl[1] = 0; 432 ip6h->flow_lbl[2] = 0; 433 434 ip6h->payload_len = htons(sizeof(struct udphdr) + len); 435 ip6h->nexthdr = IPPROTO_UDP; 436 ip6h->hop_limit = 32; 437 ip6h->saddr = np->local_ip.in6; 438 ip6h->daddr = np->remote_ip.in6; 439 440 eth = skb_push(skb, ETH_HLEN); 441 skb_reset_mac_header(skb); 442 skb->protocol = eth->h_proto = htons(ETH_P_IPV6); 443 } else { 444 udph->check = 0; 445 udph->check = csum_tcpudp_magic(np->local_ip.ip, 446 np->remote_ip.ip, 447 udp_len, IPPROTO_UDP, 448 csum_partial(udph, udp_len, 0)); 449 if (udph->check == 0) 450 udph->check = CSUM_MANGLED_0; 451 452 skb_push(skb, sizeof(*iph)); 453 skb_reset_network_header(skb); 454 iph = ip_hdr(skb); 455 456 /* iph->version = 4; iph->ihl = 5; */ 457 put_unaligned(0x45, (unsigned char *)iph); 458 iph->tos = 0; 459 put_unaligned(htons(ip_len), &(iph->tot_len)); 460 iph->id = htons(atomic_inc_return(&ip_ident)); 461 iph->frag_off = 0; 462 iph->ttl = 64; 463 iph->protocol = IPPROTO_UDP; 464 iph->check = 0; 465 put_unaligned(np->local_ip.ip, &(iph->saddr)); 466 put_unaligned(np->remote_ip.ip, &(iph->daddr)); 467 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); 468 469 eth = skb_push(skb, ETH_HLEN); 470 skb_reset_mac_header(skb); 471 skb->protocol = eth->h_proto = htons(ETH_P_IP); 472 } 473 474 ether_addr_copy(eth->h_source, np->dev->dev_addr); 475 ether_addr_copy(eth->h_dest, np->remote_mac); 476 477 skb->dev = np->dev; 478 479 netpoll_send_skb(np, skb); 480 } 481 EXPORT_SYMBOL(netpoll_send_udp); 482 483 void netpoll_print_options(struct netpoll *np) 484 { 485 np_info(np, "local port %d\n", np->local_port); 486 if (np->ipv6) 487 np_info(np, "local IPv6 address %pI6c\n", &np->local_ip.in6); 488 else 489 np_info(np, "local IPv4 address %pI4\n", &np->local_ip.ip); 490 np_info(np, "interface '%s'\n", np->dev_name); 491 np_info(np, "remote port %d\n", np->remote_port); 492 if (np->ipv6) 493 np_info(np, "remote IPv6 address %pI6c\n", &np->remote_ip.in6); 494 else 495 np_info(np, "remote IPv4 address %pI4\n", &np->remote_ip.ip); 496 np_info(np, "remote ethernet address %pM\n", np->remote_mac); 497 } 498 EXPORT_SYMBOL(netpoll_print_options); 499 500 static int netpoll_parse_ip_addr(const char *str, union inet_addr *addr) 501 { 502 const char *end; 503 504 if (!strchr(str, ':') && 505 in4_pton(str, -1, (void *)addr, -1, &end) > 0) { 506 if (!*end) 507 return 0; 508 } 509 if (in6_pton(str, -1, addr->in6.s6_addr, -1, &end) > 0) { 510 #if IS_ENABLED(CONFIG_IPV6) 511 if (!*end) 512 return 1; 513 #else 514 return -1; 515 #endif 516 } 517 return -1; 518 } 519 520 int netpoll_parse_options(struct netpoll *np, char *opt) 521 { 522 char *cur=opt, *delim; 523 int ipv6; 524 bool ipversion_set = false; 525 526 if (*cur != '@') { 527 if ((delim = strchr(cur, '@')) == NULL) 528 goto parse_failed; 529 *delim = 0; 530 if (kstrtou16(cur, 10, &np->local_port)) 531 goto parse_failed; 532 cur = delim; 533 } 534 cur++; 535 536 if (*cur != '/') { 537 ipversion_set = true; 538 if ((delim = strchr(cur, '/')) == NULL) 539 goto parse_failed; 540 *delim = 0; 541 ipv6 = netpoll_parse_ip_addr(cur, &np->local_ip); 542 if (ipv6 < 0) 543 goto parse_failed; 544 else 545 np->ipv6 = (bool)ipv6; 546 cur = delim; 547 } 548 cur++; 549 550 if (*cur != ',') { 551 /* parse out dev name */ 552 if ((delim = strchr(cur, ',')) == NULL) 553 goto parse_failed; 554 *delim = 0; 555 strlcpy(np->dev_name, cur, sizeof(np->dev_name)); 556 cur = delim; 557 } 558 cur++; 559 560 if (*cur != '@') { 561 /* dst port */ 562 if ((delim = strchr(cur, '@')) == NULL) 563 goto parse_failed; 564 *delim = 0; 565 if (*cur == ' ' || *cur == '\t') 566 np_info(np, "warning: whitespace is not allowed\n"); 567 if (kstrtou16(cur, 10, &np->remote_port)) 568 goto parse_failed; 569 cur = delim; 570 } 571 cur++; 572 573 /* dst ip */ 574 if ((delim = strchr(cur, '/')) == NULL) 575 goto parse_failed; 576 *delim = 0; 577 ipv6 = netpoll_parse_ip_addr(cur, &np->remote_ip); 578 if (ipv6 < 0) 579 goto parse_failed; 580 else if (ipversion_set && np->ipv6 != (bool)ipv6) 581 goto parse_failed; 582 else 583 np->ipv6 = (bool)ipv6; 584 cur = delim + 1; 585 586 if (*cur != 0) { 587 /* MAC address */ 588 if (!mac_pton(cur, np->remote_mac)) 589 goto parse_failed; 590 } 591 592 netpoll_print_options(np); 593 594 return 0; 595 596 parse_failed: 597 np_info(np, "couldn't parse config at '%s'!\n", cur); 598 return -1; 599 } 600 EXPORT_SYMBOL(netpoll_parse_options); 601 602 int __netpoll_setup(struct netpoll *np, struct net_device *ndev) 603 { 604 struct netpoll_info *npinfo; 605 const struct net_device_ops *ops; 606 int err; 607 608 np->dev = ndev; 609 strlcpy(np->dev_name, ndev->name, IFNAMSIZ); 610 INIT_WORK(&np->cleanup_work, netpoll_async_cleanup); 611 612 if (ndev->priv_flags & IFF_DISABLE_NETPOLL) { 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 refcount_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 refcount_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[0]) { 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 (refcount_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