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 (vlan_tx_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 udp_len = len + sizeof(*udph); 384 if (np->ipv6) 385 ip_len = udp_len + sizeof(*ip6h); 386 else 387 ip_len = udp_len + sizeof(*iph); 388 389 total_len = ip_len + LL_RESERVED_SPACE(np->dev); 390 391 skb = find_skb(np, total_len + np->dev->needed_tailroom, 392 total_len - len); 393 if (!skb) 394 return; 395 396 skb_copy_to_linear_data(skb, msg, len); 397 skb_put(skb, len); 398 399 skb_push(skb, sizeof(*udph)); 400 skb_reset_transport_header(skb); 401 udph = udp_hdr(skb); 402 udph->source = htons(np->local_port); 403 udph->dest = htons(np->remote_port); 404 udph->len = htons(udp_len); 405 406 if (np->ipv6) { 407 udph->check = 0; 408 udph->check = csum_ipv6_magic(&np->local_ip.in6, 409 &np->remote_ip.in6, 410 udp_len, IPPROTO_UDP, 411 csum_partial(udph, udp_len, 0)); 412 if (udph->check == 0) 413 udph->check = CSUM_MANGLED_0; 414 415 skb_push(skb, sizeof(*ip6h)); 416 skb_reset_network_header(skb); 417 ip6h = ipv6_hdr(skb); 418 419 /* ip6h->version = 6; ip6h->priority = 0; */ 420 put_unaligned(0x60, (unsigned char *)ip6h); 421 ip6h->flow_lbl[0] = 0; 422 ip6h->flow_lbl[1] = 0; 423 ip6h->flow_lbl[2] = 0; 424 425 ip6h->payload_len = htons(sizeof(struct udphdr) + len); 426 ip6h->nexthdr = IPPROTO_UDP; 427 ip6h->hop_limit = 32; 428 ip6h->saddr = np->local_ip.in6; 429 ip6h->daddr = np->remote_ip.in6; 430 431 eth = (struct ethhdr *) skb_push(skb, ETH_HLEN); 432 skb_reset_mac_header(skb); 433 skb->protocol = eth->h_proto = htons(ETH_P_IPV6); 434 } else { 435 udph->check = 0; 436 udph->check = csum_tcpudp_magic(np->local_ip.ip, 437 np->remote_ip.ip, 438 udp_len, IPPROTO_UDP, 439 csum_partial(udph, udp_len, 0)); 440 if (udph->check == 0) 441 udph->check = CSUM_MANGLED_0; 442 443 skb_push(skb, sizeof(*iph)); 444 skb_reset_network_header(skb); 445 iph = ip_hdr(skb); 446 447 /* iph->version = 4; iph->ihl = 5; */ 448 put_unaligned(0x45, (unsigned char *)iph); 449 iph->tos = 0; 450 put_unaligned(htons(ip_len), &(iph->tot_len)); 451 iph->id = htons(atomic_inc_return(&ip_ident)); 452 iph->frag_off = 0; 453 iph->ttl = 64; 454 iph->protocol = IPPROTO_UDP; 455 iph->check = 0; 456 put_unaligned(np->local_ip.ip, &(iph->saddr)); 457 put_unaligned(np->remote_ip.ip, &(iph->daddr)); 458 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); 459 460 eth = (struct ethhdr *) skb_push(skb, ETH_HLEN); 461 skb_reset_mac_header(skb); 462 skb->protocol = eth->h_proto = htons(ETH_P_IP); 463 } 464 465 ether_addr_copy(eth->h_source, np->dev->dev_addr); 466 ether_addr_copy(eth->h_dest, np->remote_mac); 467 468 skb->dev = np->dev; 469 470 netpoll_send_skb(np, skb); 471 } 472 EXPORT_SYMBOL(netpoll_send_udp); 473 474 void netpoll_print_options(struct netpoll *np) 475 { 476 np_info(np, "local port %d\n", np->local_port); 477 if (np->ipv6) 478 np_info(np, "local IPv6 address %pI6c\n", &np->local_ip.in6); 479 else 480 np_info(np, "local IPv4 address %pI4\n", &np->local_ip.ip); 481 np_info(np, "interface '%s'\n", np->dev_name); 482 np_info(np, "remote port %d\n", np->remote_port); 483 if (np->ipv6) 484 np_info(np, "remote IPv6 address %pI6c\n", &np->remote_ip.in6); 485 else 486 np_info(np, "remote IPv4 address %pI4\n", &np->remote_ip.ip); 487 np_info(np, "remote ethernet address %pM\n", np->remote_mac); 488 } 489 EXPORT_SYMBOL(netpoll_print_options); 490 491 static int netpoll_parse_ip_addr(const char *str, union inet_addr *addr) 492 { 493 const char *end; 494 495 if (!strchr(str, ':') && 496 in4_pton(str, -1, (void *)addr, -1, &end) > 0) { 497 if (!*end) 498 return 0; 499 } 500 if (in6_pton(str, -1, addr->in6.s6_addr, -1, &end) > 0) { 501 #if IS_ENABLED(CONFIG_IPV6) 502 if (!*end) 503 return 1; 504 #else 505 return -1; 506 #endif 507 } 508 return -1; 509 } 510 511 int netpoll_parse_options(struct netpoll *np, char *opt) 512 { 513 char *cur=opt, *delim; 514 int ipv6; 515 bool ipversion_set = false; 516 517 if (*cur != '@') { 518 if ((delim = strchr(cur, '@')) == NULL) 519 goto parse_failed; 520 *delim = 0; 521 if (kstrtou16(cur, 10, &np->local_port)) 522 goto parse_failed; 523 cur = delim; 524 } 525 cur++; 526 527 if (*cur != '/') { 528 ipversion_set = true; 529 if ((delim = strchr(cur, '/')) == NULL) 530 goto parse_failed; 531 *delim = 0; 532 ipv6 = netpoll_parse_ip_addr(cur, &np->local_ip); 533 if (ipv6 < 0) 534 goto parse_failed; 535 else 536 np->ipv6 = (bool)ipv6; 537 cur = delim; 538 } 539 cur++; 540 541 if (*cur != ',') { 542 /* parse out dev name */ 543 if ((delim = strchr(cur, ',')) == NULL) 544 goto parse_failed; 545 *delim = 0; 546 strlcpy(np->dev_name, cur, sizeof(np->dev_name)); 547 cur = delim; 548 } 549 cur++; 550 551 if (*cur != '@') { 552 /* dst port */ 553 if ((delim = strchr(cur, '@')) == NULL) 554 goto parse_failed; 555 *delim = 0; 556 if (*cur == ' ' || *cur == '\t') 557 np_info(np, "warning: whitespace is not allowed\n"); 558 if (kstrtou16(cur, 10, &np->remote_port)) 559 goto parse_failed; 560 cur = delim; 561 } 562 cur++; 563 564 /* dst ip */ 565 if ((delim = strchr(cur, '/')) == NULL) 566 goto parse_failed; 567 *delim = 0; 568 ipv6 = netpoll_parse_ip_addr(cur, &np->remote_ip); 569 if (ipv6 < 0) 570 goto parse_failed; 571 else if (ipversion_set && np->ipv6 != (bool)ipv6) 572 goto parse_failed; 573 else 574 np->ipv6 = (bool)ipv6; 575 cur = delim + 1; 576 577 if (*cur != 0) { 578 /* MAC address */ 579 if (!mac_pton(cur, np->remote_mac)) 580 goto parse_failed; 581 } 582 583 netpoll_print_options(np); 584 585 return 0; 586 587 parse_failed: 588 np_info(np, "couldn't parse config at '%s'!\n", cur); 589 return -1; 590 } 591 EXPORT_SYMBOL(netpoll_parse_options); 592 593 int __netpoll_setup(struct netpoll *np, struct net_device *ndev) 594 { 595 struct netpoll_info *npinfo; 596 const struct net_device_ops *ops; 597 int err; 598 599 np->dev = ndev; 600 strlcpy(np->dev_name, ndev->name, IFNAMSIZ); 601 INIT_WORK(&np->cleanup_work, netpoll_async_cleanup); 602 603 if ((ndev->priv_flags & IFF_DISABLE_NETPOLL) || 604 !ndev->netdev_ops->ndo_poll_controller) { 605 np_err(np, "%s doesn't support polling, aborting\n", 606 np->dev_name); 607 err = -ENOTSUPP; 608 goto out; 609 } 610 611 if (!ndev->npinfo) { 612 npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL); 613 if (!npinfo) { 614 err = -ENOMEM; 615 goto out; 616 } 617 618 sema_init(&npinfo->dev_lock, 1); 619 skb_queue_head_init(&npinfo->txq); 620 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process); 621 622 atomic_set(&npinfo->refcnt, 1); 623 624 ops = np->dev->netdev_ops; 625 if (ops->ndo_netpoll_setup) { 626 err = ops->ndo_netpoll_setup(ndev, npinfo); 627 if (err) 628 goto free_npinfo; 629 } 630 } else { 631 npinfo = rtnl_dereference(ndev->npinfo); 632 atomic_inc(&npinfo->refcnt); 633 } 634 635 npinfo->netpoll = np; 636 637 /* last thing to do is link it to the net device structure */ 638 rcu_assign_pointer(ndev->npinfo, npinfo); 639 640 return 0; 641 642 free_npinfo: 643 kfree(npinfo); 644 out: 645 return err; 646 } 647 EXPORT_SYMBOL_GPL(__netpoll_setup); 648 649 int netpoll_setup(struct netpoll *np) 650 { 651 struct net_device *ndev = NULL; 652 struct in_device *in_dev; 653 int err; 654 655 rtnl_lock(); 656 if (np->dev_name) { 657 struct net *net = current->nsproxy->net_ns; 658 ndev = __dev_get_by_name(net, np->dev_name); 659 } 660 if (!ndev) { 661 np_err(np, "%s doesn't exist, aborting\n", np->dev_name); 662 err = -ENODEV; 663 goto unlock; 664 } 665 dev_hold(ndev); 666 667 if (netdev_master_upper_dev_get(ndev)) { 668 np_err(np, "%s is a slave device, aborting\n", np->dev_name); 669 err = -EBUSY; 670 goto put; 671 } 672 673 if (!netif_running(ndev)) { 674 unsigned long atmost, atleast; 675 676 np_info(np, "device %s not up yet, forcing it\n", np->dev_name); 677 678 err = dev_open(ndev); 679 680 if (err) { 681 np_err(np, "failed to open %s\n", ndev->name); 682 goto put; 683 } 684 685 rtnl_unlock(); 686 atleast = jiffies + HZ/10; 687 atmost = jiffies + carrier_timeout * HZ; 688 while (!netif_carrier_ok(ndev)) { 689 if (time_after(jiffies, atmost)) { 690 np_notice(np, "timeout waiting for carrier\n"); 691 break; 692 } 693 msleep(1); 694 } 695 696 /* If carrier appears to come up instantly, we don't 697 * trust it and pause so that we don't pump all our 698 * queued console messages into the bitbucket. 699 */ 700 701 if (time_before(jiffies, atleast)) { 702 np_notice(np, "carrier detect appears untrustworthy, waiting 4 seconds\n"); 703 msleep(4000); 704 } 705 rtnl_lock(); 706 } 707 708 if (!np->local_ip.ip) { 709 if (!np->ipv6) { 710 in_dev = __in_dev_get_rtnl(ndev); 711 712 if (!in_dev || !in_dev->ifa_list) { 713 np_err(np, "no IP address for %s, aborting\n", 714 np->dev_name); 715 err = -EDESTADDRREQ; 716 goto put; 717 } 718 719 np->local_ip.ip = in_dev->ifa_list->ifa_local; 720 np_info(np, "local IP %pI4\n", &np->local_ip.ip); 721 } else { 722 #if IS_ENABLED(CONFIG_IPV6) 723 struct inet6_dev *idev; 724 725 err = -EDESTADDRREQ; 726 idev = __in6_dev_get(ndev); 727 if (idev) { 728 struct inet6_ifaddr *ifp; 729 730 read_lock_bh(&idev->lock); 731 list_for_each_entry(ifp, &idev->addr_list, if_list) { 732 if (ipv6_addr_type(&ifp->addr) & IPV6_ADDR_LINKLOCAL) 733 continue; 734 np->local_ip.in6 = ifp->addr; 735 err = 0; 736 break; 737 } 738 read_unlock_bh(&idev->lock); 739 } 740 if (err) { 741 np_err(np, "no IPv6 address for %s, aborting\n", 742 np->dev_name); 743 goto put; 744 } else 745 np_info(np, "local IPv6 %pI6c\n", &np->local_ip.in6); 746 #else 747 np_err(np, "IPv6 is not supported %s, aborting\n", 748 np->dev_name); 749 err = -EINVAL; 750 goto put; 751 #endif 752 } 753 } 754 755 /* fill up the skb queue */ 756 refill_skbs(); 757 758 err = __netpoll_setup(np, ndev); 759 if (err) 760 goto put; 761 762 rtnl_unlock(); 763 return 0; 764 765 put: 766 dev_put(ndev); 767 unlock: 768 rtnl_unlock(); 769 return err; 770 } 771 EXPORT_SYMBOL(netpoll_setup); 772 773 static int __init netpoll_init(void) 774 { 775 skb_queue_head_init(&skb_pool); 776 return 0; 777 } 778 core_initcall(netpoll_init); 779 780 static void rcu_cleanup_netpoll_info(struct rcu_head *rcu_head) 781 { 782 struct netpoll_info *npinfo = 783 container_of(rcu_head, struct netpoll_info, rcu); 784 785 skb_queue_purge(&npinfo->txq); 786 787 /* we can't call cancel_delayed_work_sync here, as we are in softirq */ 788 cancel_delayed_work(&npinfo->tx_work); 789 790 /* clean after last, unfinished work */ 791 __skb_queue_purge(&npinfo->txq); 792 /* now cancel it again */ 793 cancel_delayed_work(&npinfo->tx_work); 794 kfree(npinfo); 795 } 796 797 void __netpoll_cleanup(struct netpoll *np) 798 { 799 struct netpoll_info *npinfo; 800 801 /* rtnl_dereference would be preferable here but 802 * rcu_cleanup_netpoll path can put us in here safely without 803 * holding the rtnl, so plain rcu_dereference it is 804 */ 805 npinfo = rtnl_dereference(np->dev->npinfo); 806 if (!npinfo) 807 return; 808 809 synchronize_srcu(&netpoll_srcu); 810 811 if (atomic_dec_and_test(&npinfo->refcnt)) { 812 const struct net_device_ops *ops; 813 814 ops = np->dev->netdev_ops; 815 if (ops->ndo_netpoll_cleanup) 816 ops->ndo_netpoll_cleanup(np->dev); 817 818 RCU_INIT_POINTER(np->dev->npinfo, NULL); 819 call_rcu_bh(&npinfo->rcu, rcu_cleanup_netpoll_info); 820 } else 821 RCU_INIT_POINTER(np->dev->npinfo, NULL); 822 } 823 EXPORT_SYMBOL_GPL(__netpoll_cleanup); 824 825 static void netpoll_async_cleanup(struct work_struct *work) 826 { 827 struct netpoll *np = container_of(work, struct netpoll, cleanup_work); 828 829 rtnl_lock(); 830 __netpoll_cleanup(np); 831 rtnl_unlock(); 832 kfree(np); 833 } 834 835 void __netpoll_free_async(struct netpoll *np) 836 { 837 schedule_work(&np->cleanup_work); 838 } 839 EXPORT_SYMBOL_GPL(__netpoll_free_async); 840 841 void netpoll_cleanup(struct netpoll *np) 842 { 843 rtnl_lock(); 844 if (!np->dev) 845 goto out; 846 __netpoll_cleanup(np); 847 dev_put(np->dev); 848 np->dev = NULL; 849 out: 850 rtnl_unlock(); 851 } 852 EXPORT_SYMBOL(netpoll_cleanup); 853