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 61 static unsigned int carrier_timeout = 4; 62 module_param(carrier_timeout, uint, 0644); 63 64 #define np_info(np, fmt, ...) \ 65 pr_info("%s: " fmt, np->name, ##__VA_ARGS__) 66 #define np_err(np, fmt, ...) \ 67 pr_err("%s: " fmt, np->name, ##__VA_ARGS__) 68 #define np_notice(np, fmt, ...) \ 69 pr_notice("%s: " fmt, np->name, ##__VA_ARGS__) 70 71 static int netpoll_start_xmit(struct sk_buff *skb, struct net_device *dev, 72 struct netdev_queue *txq) 73 { 74 int status = NETDEV_TX_OK; 75 netdev_features_t features; 76 77 features = netif_skb_features(skb); 78 79 if (skb_vlan_tag_present(skb) && 80 !vlan_hw_offload_capable(features, skb->vlan_proto)) { 81 skb = __vlan_hwaccel_push_inside(skb); 82 if (unlikely(!skb)) { 83 /* This is actually a packet drop, but we 84 * don't want the code that calls this 85 * function to try and operate on a NULL skb. 86 */ 87 goto out; 88 } 89 } 90 91 status = netdev_start_xmit(skb, dev, txq, false); 92 93 out: 94 return status; 95 } 96 97 static void queue_process(struct work_struct *work) 98 { 99 struct netpoll_info *npinfo = 100 container_of(work, struct netpoll_info, tx_work.work); 101 struct sk_buff *skb; 102 unsigned long flags; 103 104 while ((skb = skb_dequeue(&npinfo->txq))) { 105 struct net_device *dev = skb->dev; 106 struct netdev_queue *txq; 107 unsigned int q_index; 108 109 if (!netif_device_present(dev) || !netif_running(dev)) { 110 kfree_skb(skb); 111 continue; 112 } 113 114 local_irq_save(flags); 115 /* check if skb->queue_mapping is still valid */ 116 q_index = skb_get_queue_mapping(skb); 117 if (unlikely(q_index >= dev->real_num_tx_queues)) { 118 q_index = q_index % dev->real_num_tx_queues; 119 skb_set_queue_mapping(skb, q_index); 120 } 121 txq = netdev_get_tx_queue(dev, q_index); 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 static void poll_one_napi(struct napi_struct *napi) 138 { 139 int work; 140 141 /* If we set this bit but see that it has already been set, 142 * that indicates that napi has been disabled and we need 143 * to abort this operation 144 */ 145 if (test_and_set_bit(NAPI_STATE_NPSVC, &napi->state)) 146 return; 147 148 /* We explicilty pass the polling call a budget of 0 to 149 * indicate that we are clearing the Tx path only. 150 */ 151 work = napi->poll(napi, 0); 152 WARN_ONCE(work, "%pF exceeded budget in poll\n", napi->poll); 153 trace_napi_poll(napi, work, 0); 154 155 clear_bit(NAPI_STATE_NPSVC, &napi->state); 156 } 157 158 static void poll_napi(struct net_device *dev) 159 { 160 struct napi_struct *napi; 161 int cpu = smp_processor_id(); 162 163 list_for_each_entry(napi, &dev->napi_list, dev_list) { 164 if (cmpxchg(&napi->poll_owner, -1, cpu) == -1) { 165 poll_one_napi(napi); 166 smp_store_release(&napi->poll_owner, -1); 167 } 168 } 169 } 170 171 void netpoll_poll_dev(struct net_device *dev) 172 { 173 struct netpoll_info *ni = rcu_dereference_bh(dev->npinfo); 174 const struct net_device_ops *ops; 175 176 /* Don't do any rx activity if the dev_lock mutex is held 177 * the dev_open/close paths use this to block netpoll activity 178 * while changing device state 179 */ 180 if (!ni || down_trylock(&ni->dev_lock)) 181 return; 182 183 if (!netif_running(dev)) { 184 up(&ni->dev_lock); 185 return; 186 } 187 188 ops = dev->netdev_ops; 189 if (ops->ndo_poll_controller) 190 ops->ndo_poll_controller(dev); 191 192 poll_napi(dev); 193 194 up(&ni->dev_lock); 195 196 zap_completion_queue(); 197 } 198 EXPORT_SYMBOL(netpoll_poll_dev); 199 200 void netpoll_poll_disable(struct net_device *dev) 201 { 202 struct netpoll_info *ni; 203 int idx; 204 might_sleep(); 205 idx = srcu_read_lock(&netpoll_srcu); 206 ni = srcu_dereference(dev->npinfo, &netpoll_srcu); 207 if (ni) 208 down(&ni->dev_lock); 209 srcu_read_unlock(&netpoll_srcu, idx); 210 } 211 EXPORT_SYMBOL(netpoll_poll_disable); 212 213 void netpoll_poll_enable(struct net_device *dev) 214 { 215 struct netpoll_info *ni; 216 rcu_read_lock(); 217 ni = rcu_dereference(dev->npinfo); 218 if (ni) 219 up(&ni->dev_lock); 220 rcu_read_unlock(); 221 } 222 EXPORT_SYMBOL(netpoll_poll_enable); 223 224 static void refill_skbs(void) 225 { 226 struct sk_buff *skb; 227 unsigned long flags; 228 229 spin_lock_irqsave(&skb_pool.lock, flags); 230 while (skb_pool.qlen < MAX_SKBS) { 231 skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC); 232 if (!skb) 233 break; 234 235 __skb_queue_tail(&skb_pool, skb); 236 } 237 spin_unlock_irqrestore(&skb_pool.lock, flags); 238 } 239 240 static void zap_completion_queue(void) 241 { 242 unsigned long flags; 243 struct softnet_data *sd = &get_cpu_var(softnet_data); 244 245 if (sd->completion_queue) { 246 struct sk_buff *clist; 247 248 local_irq_save(flags); 249 clist = sd->completion_queue; 250 sd->completion_queue = NULL; 251 local_irq_restore(flags); 252 253 while (clist != NULL) { 254 struct sk_buff *skb = clist; 255 clist = clist->next; 256 if (!skb_irq_freeable(skb)) { 257 refcount_set(&skb->users, 1); 258 dev_kfree_skb_any(skb); /* put this one back */ 259 } else { 260 __kfree_skb(skb); 261 } 262 } 263 } 264 265 put_cpu_var(softnet_data); 266 } 267 268 static struct sk_buff *find_skb(struct netpoll *np, int len, int reserve) 269 { 270 int count = 0; 271 struct sk_buff *skb; 272 273 zap_completion_queue(); 274 refill_skbs(); 275 repeat: 276 277 skb = alloc_skb(len, GFP_ATOMIC); 278 if (!skb) 279 skb = skb_dequeue(&skb_pool); 280 281 if (!skb) { 282 if (++count < 10) { 283 netpoll_poll_dev(np->dev); 284 goto repeat; 285 } 286 return NULL; 287 } 288 289 refcount_set(&skb->users, 1); 290 skb_reserve(skb, reserve); 291 return skb; 292 } 293 294 static int netpoll_owner_active(struct net_device *dev) 295 { 296 struct napi_struct *napi; 297 298 list_for_each_entry(napi, &dev->napi_list, dev_list) { 299 if (napi->poll_owner == smp_processor_id()) 300 return 1; 301 } 302 return 0; 303 } 304 305 /* call with IRQ disabled */ 306 void netpoll_send_skb_on_dev(struct netpoll *np, struct sk_buff *skb, 307 struct net_device *dev) 308 { 309 int status = NETDEV_TX_BUSY; 310 unsigned long tries; 311 /* It is up to the caller to keep npinfo alive. */ 312 struct netpoll_info *npinfo; 313 314 lockdep_assert_irqs_disabled(); 315 316 npinfo = rcu_dereference_bh(np->dev->npinfo); 317 if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) { 318 dev_kfree_skb_irq(skb); 319 return; 320 } 321 322 /* don't get messages out of order, and no recursion */ 323 if (skb_queue_len(&npinfo->txq) == 0 && !netpoll_owner_active(dev)) { 324 struct netdev_queue *txq; 325 326 txq = netdev_pick_tx(dev, skb, NULL); 327 328 /* try until next clock tick */ 329 for (tries = jiffies_to_usecs(1)/USEC_PER_POLL; 330 tries > 0; --tries) { 331 if (HARD_TX_TRYLOCK(dev, txq)) { 332 if (!netif_xmit_stopped(txq)) 333 status = netpoll_start_xmit(skb, dev, txq); 334 335 HARD_TX_UNLOCK(dev, txq); 336 337 if (status == NETDEV_TX_OK) 338 break; 339 340 } 341 342 /* tickle device maybe there is some cleanup */ 343 netpoll_poll_dev(np->dev); 344 345 udelay(USEC_PER_POLL); 346 } 347 348 WARN_ONCE(!irqs_disabled(), 349 "netpoll_send_skb_on_dev(): %s enabled interrupts in poll (%pF)\n", 350 dev->name, dev->netdev_ops->ndo_start_xmit); 351 352 } 353 354 if (status != NETDEV_TX_OK) { 355 skb_queue_tail(&npinfo->txq, skb); 356 schedule_delayed_work(&npinfo->tx_work,0); 357 } 358 } 359 EXPORT_SYMBOL(netpoll_send_skb_on_dev); 360 361 void netpoll_send_udp(struct netpoll *np, const char *msg, int len) 362 { 363 int total_len, ip_len, udp_len; 364 struct sk_buff *skb; 365 struct udphdr *udph; 366 struct iphdr *iph; 367 struct ethhdr *eth; 368 static atomic_t ip_ident; 369 struct ipv6hdr *ip6h; 370 371 WARN_ON_ONCE(!irqs_disabled()); 372 373 udp_len = len + sizeof(*udph); 374 if (np->ipv6) 375 ip_len = udp_len + sizeof(*ip6h); 376 else 377 ip_len = udp_len + sizeof(*iph); 378 379 total_len = ip_len + LL_RESERVED_SPACE(np->dev); 380 381 skb = find_skb(np, total_len + np->dev->needed_tailroom, 382 total_len - len); 383 if (!skb) 384 return; 385 386 skb_copy_to_linear_data(skb, msg, len); 387 skb_put(skb, len); 388 389 skb_push(skb, sizeof(*udph)); 390 skb_reset_transport_header(skb); 391 udph = udp_hdr(skb); 392 udph->source = htons(np->local_port); 393 udph->dest = htons(np->remote_port); 394 udph->len = htons(udp_len); 395 396 if (np->ipv6) { 397 udph->check = 0; 398 udph->check = csum_ipv6_magic(&np->local_ip.in6, 399 &np->remote_ip.in6, 400 udp_len, IPPROTO_UDP, 401 csum_partial(udph, udp_len, 0)); 402 if (udph->check == 0) 403 udph->check = CSUM_MANGLED_0; 404 405 skb_push(skb, sizeof(*ip6h)); 406 skb_reset_network_header(skb); 407 ip6h = ipv6_hdr(skb); 408 409 /* ip6h->version = 6; ip6h->priority = 0; */ 410 put_unaligned(0x60, (unsigned char *)ip6h); 411 ip6h->flow_lbl[0] = 0; 412 ip6h->flow_lbl[1] = 0; 413 ip6h->flow_lbl[2] = 0; 414 415 ip6h->payload_len = htons(sizeof(struct udphdr) + len); 416 ip6h->nexthdr = IPPROTO_UDP; 417 ip6h->hop_limit = 32; 418 ip6h->saddr = np->local_ip.in6; 419 ip6h->daddr = np->remote_ip.in6; 420 421 eth = skb_push(skb, ETH_HLEN); 422 skb_reset_mac_header(skb); 423 skb->protocol = eth->h_proto = htons(ETH_P_IPV6); 424 } else { 425 udph->check = 0; 426 udph->check = csum_tcpudp_magic(np->local_ip.ip, 427 np->remote_ip.ip, 428 udp_len, IPPROTO_UDP, 429 csum_partial(udph, udp_len, 0)); 430 if (udph->check == 0) 431 udph->check = CSUM_MANGLED_0; 432 433 skb_push(skb, sizeof(*iph)); 434 skb_reset_network_header(skb); 435 iph = ip_hdr(skb); 436 437 /* iph->version = 4; iph->ihl = 5; */ 438 put_unaligned(0x45, (unsigned char *)iph); 439 iph->tos = 0; 440 put_unaligned(htons(ip_len), &(iph->tot_len)); 441 iph->id = htons(atomic_inc_return(&ip_ident)); 442 iph->frag_off = 0; 443 iph->ttl = 64; 444 iph->protocol = IPPROTO_UDP; 445 iph->check = 0; 446 put_unaligned(np->local_ip.ip, &(iph->saddr)); 447 put_unaligned(np->remote_ip.ip, &(iph->daddr)); 448 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); 449 450 eth = skb_push(skb, ETH_HLEN); 451 skb_reset_mac_header(skb); 452 skb->protocol = eth->h_proto = htons(ETH_P_IP); 453 } 454 455 ether_addr_copy(eth->h_source, np->dev->dev_addr); 456 ether_addr_copy(eth->h_dest, np->remote_mac); 457 458 skb->dev = np->dev; 459 460 netpoll_send_skb(np, skb); 461 } 462 EXPORT_SYMBOL(netpoll_send_udp); 463 464 void netpoll_print_options(struct netpoll *np) 465 { 466 np_info(np, "local port %d\n", np->local_port); 467 if (np->ipv6) 468 np_info(np, "local IPv6 address %pI6c\n", &np->local_ip.in6); 469 else 470 np_info(np, "local IPv4 address %pI4\n", &np->local_ip.ip); 471 np_info(np, "interface '%s'\n", np->dev_name); 472 np_info(np, "remote port %d\n", np->remote_port); 473 if (np->ipv6) 474 np_info(np, "remote IPv6 address %pI6c\n", &np->remote_ip.in6); 475 else 476 np_info(np, "remote IPv4 address %pI4\n", &np->remote_ip.ip); 477 np_info(np, "remote ethernet address %pM\n", np->remote_mac); 478 } 479 EXPORT_SYMBOL(netpoll_print_options); 480 481 static int netpoll_parse_ip_addr(const char *str, union inet_addr *addr) 482 { 483 const char *end; 484 485 if (!strchr(str, ':') && 486 in4_pton(str, -1, (void *)addr, -1, &end) > 0) { 487 if (!*end) 488 return 0; 489 } 490 if (in6_pton(str, -1, addr->in6.s6_addr, -1, &end) > 0) { 491 #if IS_ENABLED(CONFIG_IPV6) 492 if (!*end) 493 return 1; 494 #else 495 return -1; 496 #endif 497 } 498 return -1; 499 } 500 501 int netpoll_parse_options(struct netpoll *np, char *opt) 502 { 503 char *cur=opt, *delim; 504 int ipv6; 505 bool ipversion_set = false; 506 507 if (*cur != '@') { 508 if ((delim = strchr(cur, '@')) == NULL) 509 goto parse_failed; 510 *delim = 0; 511 if (kstrtou16(cur, 10, &np->local_port)) 512 goto parse_failed; 513 cur = delim; 514 } 515 cur++; 516 517 if (*cur != '/') { 518 ipversion_set = true; 519 if ((delim = strchr(cur, '/')) == NULL) 520 goto parse_failed; 521 *delim = 0; 522 ipv6 = netpoll_parse_ip_addr(cur, &np->local_ip); 523 if (ipv6 < 0) 524 goto parse_failed; 525 else 526 np->ipv6 = (bool)ipv6; 527 cur = delim; 528 } 529 cur++; 530 531 if (*cur != ',') { 532 /* parse out dev name */ 533 if ((delim = strchr(cur, ',')) == NULL) 534 goto parse_failed; 535 *delim = 0; 536 strlcpy(np->dev_name, cur, sizeof(np->dev_name)); 537 cur = delim; 538 } 539 cur++; 540 541 if (*cur != '@') { 542 /* dst port */ 543 if ((delim = strchr(cur, '@')) == NULL) 544 goto parse_failed; 545 *delim = 0; 546 if (*cur == ' ' || *cur == '\t') 547 np_info(np, "warning: whitespace is not allowed\n"); 548 if (kstrtou16(cur, 10, &np->remote_port)) 549 goto parse_failed; 550 cur = delim; 551 } 552 cur++; 553 554 /* dst ip */ 555 if ((delim = strchr(cur, '/')) == NULL) 556 goto parse_failed; 557 *delim = 0; 558 ipv6 = netpoll_parse_ip_addr(cur, &np->remote_ip); 559 if (ipv6 < 0) 560 goto parse_failed; 561 else if (ipversion_set && np->ipv6 != (bool)ipv6) 562 goto parse_failed; 563 else 564 np->ipv6 = (bool)ipv6; 565 cur = delim + 1; 566 567 if (*cur != 0) { 568 /* MAC address */ 569 if (!mac_pton(cur, np->remote_mac)) 570 goto parse_failed; 571 } 572 573 netpoll_print_options(np); 574 575 return 0; 576 577 parse_failed: 578 np_info(np, "couldn't parse config at '%s'!\n", cur); 579 return -1; 580 } 581 EXPORT_SYMBOL(netpoll_parse_options); 582 583 int __netpoll_setup(struct netpoll *np, struct net_device *ndev) 584 { 585 struct netpoll_info *npinfo; 586 const struct net_device_ops *ops; 587 int err; 588 589 np->dev = ndev; 590 strlcpy(np->dev_name, ndev->name, IFNAMSIZ); 591 592 if (ndev->priv_flags & IFF_DISABLE_NETPOLL) { 593 np_err(np, "%s doesn't support polling, aborting\n", 594 np->dev_name); 595 err = -ENOTSUPP; 596 goto out; 597 } 598 599 if (!ndev->npinfo) { 600 npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL); 601 if (!npinfo) { 602 err = -ENOMEM; 603 goto out; 604 } 605 606 sema_init(&npinfo->dev_lock, 1); 607 skb_queue_head_init(&npinfo->txq); 608 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process); 609 610 refcount_set(&npinfo->refcnt, 1); 611 612 ops = np->dev->netdev_ops; 613 if (ops->ndo_netpoll_setup) { 614 err = ops->ndo_netpoll_setup(ndev, npinfo); 615 if (err) 616 goto free_npinfo; 617 } 618 } else { 619 npinfo = rtnl_dereference(ndev->npinfo); 620 refcount_inc(&npinfo->refcnt); 621 } 622 623 npinfo->netpoll = np; 624 625 /* last thing to do is link it to the net device structure */ 626 rcu_assign_pointer(ndev->npinfo, npinfo); 627 628 return 0; 629 630 free_npinfo: 631 kfree(npinfo); 632 out: 633 return err; 634 } 635 EXPORT_SYMBOL_GPL(__netpoll_setup); 636 637 int netpoll_setup(struct netpoll *np) 638 { 639 struct net_device *ndev = NULL; 640 struct in_device *in_dev; 641 int err; 642 643 rtnl_lock(); 644 if (np->dev_name[0]) { 645 struct net *net = current->nsproxy->net_ns; 646 ndev = __dev_get_by_name(net, np->dev_name); 647 } 648 if (!ndev) { 649 np_err(np, "%s doesn't exist, aborting\n", np->dev_name); 650 err = -ENODEV; 651 goto unlock; 652 } 653 dev_hold(ndev); 654 655 if (netdev_master_upper_dev_get(ndev)) { 656 np_err(np, "%s is a slave device, aborting\n", np->dev_name); 657 err = -EBUSY; 658 goto put; 659 } 660 661 if (!netif_running(ndev)) { 662 unsigned long atmost, atleast; 663 664 np_info(np, "device %s not up yet, forcing it\n", np->dev_name); 665 666 err = dev_open(ndev); 667 668 if (err) { 669 np_err(np, "failed to open %s\n", ndev->name); 670 goto put; 671 } 672 673 rtnl_unlock(); 674 atleast = jiffies + HZ/10; 675 atmost = jiffies + carrier_timeout * HZ; 676 while (!netif_carrier_ok(ndev)) { 677 if (time_after(jiffies, atmost)) { 678 np_notice(np, "timeout waiting for carrier\n"); 679 break; 680 } 681 msleep(1); 682 } 683 684 /* If carrier appears to come up instantly, we don't 685 * trust it and pause so that we don't pump all our 686 * queued console messages into the bitbucket. 687 */ 688 689 if (time_before(jiffies, atleast)) { 690 np_notice(np, "carrier detect appears untrustworthy, waiting 4 seconds\n"); 691 msleep(4000); 692 } 693 rtnl_lock(); 694 } 695 696 if (!np->local_ip.ip) { 697 if (!np->ipv6) { 698 in_dev = __in_dev_get_rtnl(ndev); 699 700 if (!in_dev || !in_dev->ifa_list) { 701 np_err(np, "no IP address for %s, aborting\n", 702 np->dev_name); 703 err = -EDESTADDRREQ; 704 goto put; 705 } 706 707 np->local_ip.ip = in_dev->ifa_list->ifa_local; 708 np_info(np, "local IP %pI4\n", &np->local_ip.ip); 709 } else { 710 #if IS_ENABLED(CONFIG_IPV6) 711 struct inet6_dev *idev; 712 713 err = -EDESTADDRREQ; 714 idev = __in6_dev_get(ndev); 715 if (idev) { 716 struct inet6_ifaddr *ifp; 717 718 read_lock_bh(&idev->lock); 719 list_for_each_entry(ifp, &idev->addr_list, if_list) { 720 if (!!(ipv6_addr_type(&ifp->addr) & IPV6_ADDR_LINKLOCAL) != 721 !!(ipv6_addr_type(&np->remote_ip.in6) & IPV6_ADDR_LINKLOCAL)) 722 continue; 723 np->local_ip.in6 = ifp->addr; 724 err = 0; 725 break; 726 } 727 read_unlock_bh(&idev->lock); 728 } 729 if (err) { 730 np_err(np, "no IPv6 address for %s, aborting\n", 731 np->dev_name); 732 goto put; 733 } else 734 np_info(np, "local IPv6 %pI6c\n", &np->local_ip.in6); 735 #else 736 np_err(np, "IPv6 is not supported %s, aborting\n", 737 np->dev_name); 738 err = -EINVAL; 739 goto put; 740 #endif 741 } 742 } 743 744 /* fill up the skb queue */ 745 refill_skbs(); 746 747 err = __netpoll_setup(np, ndev); 748 if (err) 749 goto put; 750 751 rtnl_unlock(); 752 return 0; 753 754 put: 755 dev_put(ndev); 756 unlock: 757 rtnl_unlock(); 758 return err; 759 } 760 EXPORT_SYMBOL(netpoll_setup); 761 762 static int __init netpoll_init(void) 763 { 764 skb_queue_head_init(&skb_pool); 765 return 0; 766 } 767 core_initcall(netpoll_init); 768 769 static void rcu_cleanup_netpoll_info(struct rcu_head *rcu_head) 770 { 771 struct netpoll_info *npinfo = 772 container_of(rcu_head, struct netpoll_info, rcu); 773 774 skb_queue_purge(&npinfo->txq); 775 776 /* we can't call cancel_delayed_work_sync here, as we are in softirq */ 777 cancel_delayed_work(&npinfo->tx_work); 778 779 /* clean after last, unfinished work */ 780 __skb_queue_purge(&npinfo->txq); 781 /* now cancel it again */ 782 cancel_delayed_work(&npinfo->tx_work); 783 kfree(npinfo); 784 } 785 786 void __netpoll_cleanup(struct netpoll *np) 787 { 788 struct netpoll_info *npinfo; 789 790 npinfo = rtnl_dereference(np->dev->npinfo); 791 if (!npinfo) 792 return; 793 794 synchronize_srcu(&netpoll_srcu); 795 796 if (refcount_dec_and_test(&npinfo->refcnt)) { 797 const struct net_device_ops *ops; 798 799 ops = np->dev->netdev_ops; 800 if (ops->ndo_netpoll_cleanup) 801 ops->ndo_netpoll_cleanup(np->dev); 802 803 RCU_INIT_POINTER(np->dev->npinfo, NULL); 804 call_rcu_bh(&npinfo->rcu, rcu_cleanup_netpoll_info); 805 } else 806 RCU_INIT_POINTER(np->dev->npinfo, NULL); 807 } 808 EXPORT_SYMBOL_GPL(__netpoll_cleanup); 809 810 void __netpoll_free(struct netpoll *np) 811 { 812 ASSERT_RTNL(); 813 814 /* Wait for transmitting packets to finish before freeing. */ 815 synchronize_rcu_bh(); 816 __netpoll_cleanup(np); 817 kfree(np); 818 } 819 EXPORT_SYMBOL_GPL(__netpoll_free); 820 821 void netpoll_cleanup(struct netpoll *np) 822 { 823 rtnl_lock(); 824 if (!np->dev) 825 goto out; 826 __netpoll_cleanup(np); 827 dev_put(np->dev); 828 np->dev = NULL; 829 out: 830 rtnl_unlock(); 831 } 832 EXPORT_SYMBOL(netpoll_cleanup); 833