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