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 static void poll_one_napi(struct napi_struct *napi) 139 { 140 int work; 141 142 /* If we set this bit but see that it has already been set, 143 * that indicates that napi has been disabled and we need 144 * to abort this operation 145 */ 146 if (test_and_set_bit(NAPI_STATE_NPSVC, &napi->state)) 147 return; 148 149 /* We explicilty pass the polling call a budget of 0 to 150 * indicate that we are clearing the Tx path only. 151 */ 152 work = napi->poll(napi, 0); 153 WARN_ONCE(work, "%pF exceeded budget in poll\n", napi->poll); 154 trace_napi_poll(napi, work, 0); 155 156 clear_bit(NAPI_STATE_NPSVC, &napi->state); 157 } 158 159 static void poll_napi(struct net_device *dev) 160 { 161 struct napi_struct *napi; 162 int cpu = smp_processor_id(); 163 164 list_for_each_entry(napi, &dev->napi_list, dev_list) { 165 if (cmpxchg(&napi->poll_owner, -1, cpu) == -1) { 166 poll_one_napi(napi); 167 smp_store_release(&napi->poll_owner, -1); 168 } 169 } 170 } 171 172 void netpoll_poll_dev(struct net_device *dev) 173 { 174 struct netpoll_info *ni = rcu_dereference_bh(dev->npinfo); 175 const struct net_device_ops *ops; 176 177 /* Don't do any rx activity if the dev_lock mutex is held 178 * the dev_open/close paths use this to block netpoll activity 179 * while changing device state 180 */ 181 if (!ni || down_trylock(&ni->dev_lock)) 182 return; 183 184 if (!netif_running(dev)) { 185 up(&ni->dev_lock); 186 return; 187 } 188 189 ops = dev->netdev_ops; 190 if (ops->ndo_poll_controller) 191 ops->ndo_poll_controller(dev); 192 193 poll_napi(dev); 194 195 up(&ni->dev_lock); 196 197 zap_completion_queue(); 198 } 199 EXPORT_SYMBOL(netpoll_poll_dev); 200 201 void netpoll_poll_disable(struct net_device *dev) 202 { 203 struct netpoll_info *ni; 204 int idx; 205 might_sleep(); 206 idx = srcu_read_lock(&netpoll_srcu); 207 ni = srcu_dereference(dev->npinfo, &netpoll_srcu); 208 if (ni) 209 down(&ni->dev_lock); 210 srcu_read_unlock(&netpoll_srcu, idx); 211 } 212 EXPORT_SYMBOL(netpoll_poll_disable); 213 214 void netpoll_poll_enable(struct net_device *dev) 215 { 216 struct netpoll_info *ni; 217 rcu_read_lock(); 218 ni = rcu_dereference(dev->npinfo); 219 if (ni) 220 up(&ni->dev_lock); 221 rcu_read_unlock(); 222 } 223 EXPORT_SYMBOL(netpoll_poll_enable); 224 225 static void refill_skbs(void) 226 { 227 struct sk_buff *skb; 228 unsigned long flags; 229 230 spin_lock_irqsave(&skb_pool.lock, flags); 231 while (skb_pool.qlen < MAX_SKBS) { 232 skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC); 233 if (!skb) 234 break; 235 236 __skb_queue_tail(&skb_pool, skb); 237 } 238 spin_unlock_irqrestore(&skb_pool.lock, flags); 239 } 240 241 static void zap_completion_queue(void) 242 { 243 unsigned long flags; 244 struct softnet_data *sd = &get_cpu_var(softnet_data); 245 246 if (sd->completion_queue) { 247 struct sk_buff *clist; 248 249 local_irq_save(flags); 250 clist = sd->completion_queue; 251 sd->completion_queue = NULL; 252 local_irq_restore(flags); 253 254 while (clist != NULL) { 255 struct sk_buff *skb = clist; 256 clist = clist->next; 257 if (!skb_irq_freeable(skb)) { 258 refcount_set(&skb->users, 1); 259 dev_kfree_skb_any(skb); /* put this one back */ 260 } else { 261 __kfree_skb(skb); 262 } 263 } 264 } 265 266 put_cpu_var(softnet_data); 267 } 268 269 static struct sk_buff *find_skb(struct netpoll *np, int len, int reserve) 270 { 271 int count = 0; 272 struct sk_buff *skb; 273 274 zap_completion_queue(); 275 refill_skbs(); 276 repeat: 277 278 skb = alloc_skb(len, GFP_ATOMIC); 279 if (!skb) 280 skb = skb_dequeue(&skb_pool); 281 282 if (!skb) { 283 if (++count < 10) { 284 netpoll_poll_dev(np->dev); 285 goto repeat; 286 } 287 return NULL; 288 } 289 290 refcount_set(&skb->users, 1); 291 skb_reserve(skb, reserve); 292 return skb; 293 } 294 295 static int netpoll_owner_active(struct net_device *dev) 296 { 297 struct napi_struct *napi; 298 299 list_for_each_entry(napi, &dev->napi_list, dev_list) { 300 if (napi->poll_owner == smp_processor_id()) 301 return 1; 302 } 303 return 0; 304 } 305 306 /* call with IRQ disabled */ 307 void netpoll_send_skb_on_dev(struct netpoll *np, struct sk_buff *skb, 308 struct net_device *dev) 309 { 310 int status = NETDEV_TX_BUSY; 311 unsigned long tries; 312 /* It is up to the caller to keep npinfo alive. */ 313 struct netpoll_info *npinfo; 314 315 rcu_read_lock_bh(); 316 lockdep_assert_irqs_disabled(); 317 318 npinfo = rcu_dereference_bh(np->dev->npinfo); 319 if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) { 320 dev_kfree_skb_irq(skb); 321 return; 322 } 323 324 /* don't get messages out of order, and no recursion */ 325 if (skb_queue_len(&npinfo->txq) == 0 && !netpoll_owner_active(dev)) { 326 struct netdev_queue *txq; 327 328 txq = netdev_pick_tx(dev, skb, NULL); 329 330 /* try until next clock tick */ 331 for (tries = jiffies_to_usecs(1)/USEC_PER_POLL; 332 tries > 0; --tries) { 333 if (HARD_TX_TRYLOCK(dev, txq)) { 334 if (!netif_xmit_stopped(txq)) 335 status = netpoll_start_xmit(skb, dev, txq); 336 337 HARD_TX_UNLOCK(dev, txq); 338 339 if (status == NETDEV_TX_OK) 340 break; 341 342 } 343 344 /* tickle device maybe there is some cleanup */ 345 netpoll_poll_dev(np->dev); 346 347 udelay(USEC_PER_POLL); 348 } 349 350 WARN_ONCE(!irqs_disabled(), 351 "netpoll_send_skb_on_dev(): %s enabled interrupts in poll (%pF)\n", 352 dev->name, dev->netdev_ops->ndo_start_xmit); 353 354 } 355 356 if (status != NETDEV_TX_OK) { 357 skb_queue_tail(&npinfo->txq, skb); 358 schedule_delayed_work(&npinfo->tx_work,0); 359 } 360 rcu_read_unlock_bh(); 361 } 362 EXPORT_SYMBOL(netpoll_send_skb_on_dev); 363 364 void netpoll_send_udp(struct netpoll *np, const char *msg, int len) 365 { 366 int total_len, ip_len, udp_len; 367 struct sk_buff *skb; 368 struct udphdr *udph; 369 struct iphdr *iph; 370 struct ethhdr *eth; 371 static atomic_t ip_ident; 372 struct ipv6hdr *ip6h; 373 374 WARN_ON_ONCE(!irqs_disabled()); 375 376 udp_len = len + sizeof(*udph); 377 if (np->ipv6) 378 ip_len = udp_len + sizeof(*ip6h); 379 else 380 ip_len = udp_len + sizeof(*iph); 381 382 total_len = ip_len + LL_RESERVED_SPACE(np->dev); 383 384 skb = find_skb(np, total_len + np->dev->needed_tailroom, 385 total_len - len); 386 if (!skb) 387 return; 388 389 skb_copy_to_linear_data(skb, msg, len); 390 skb_put(skb, len); 391 392 skb_push(skb, sizeof(*udph)); 393 skb_reset_transport_header(skb); 394 udph = udp_hdr(skb); 395 udph->source = htons(np->local_port); 396 udph->dest = htons(np->remote_port); 397 udph->len = htons(udp_len); 398 399 if (np->ipv6) { 400 udph->check = 0; 401 udph->check = csum_ipv6_magic(&np->local_ip.in6, 402 &np->remote_ip.in6, 403 udp_len, IPPROTO_UDP, 404 csum_partial(udph, udp_len, 0)); 405 if (udph->check == 0) 406 udph->check = CSUM_MANGLED_0; 407 408 skb_push(skb, sizeof(*ip6h)); 409 skb_reset_network_header(skb); 410 ip6h = ipv6_hdr(skb); 411 412 /* ip6h->version = 6; ip6h->priority = 0; */ 413 put_unaligned(0x60, (unsigned char *)ip6h); 414 ip6h->flow_lbl[0] = 0; 415 ip6h->flow_lbl[1] = 0; 416 ip6h->flow_lbl[2] = 0; 417 418 ip6h->payload_len = htons(sizeof(struct udphdr) + len); 419 ip6h->nexthdr = IPPROTO_UDP; 420 ip6h->hop_limit = 32; 421 ip6h->saddr = np->local_ip.in6; 422 ip6h->daddr = np->remote_ip.in6; 423 424 eth = skb_push(skb, ETH_HLEN); 425 skb_reset_mac_header(skb); 426 skb->protocol = eth->h_proto = htons(ETH_P_IPV6); 427 } else { 428 udph->check = 0; 429 udph->check = csum_tcpudp_magic(np->local_ip.ip, 430 np->remote_ip.ip, 431 udp_len, IPPROTO_UDP, 432 csum_partial(udph, udp_len, 0)); 433 if (udph->check == 0) 434 udph->check = CSUM_MANGLED_0; 435 436 skb_push(skb, sizeof(*iph)); 437 skb_reset_network_header(skb); 438 iph = ip_hdr(skb); 439 440 /* iph->version = 4; iph->ihl = 5; */ 441 put_unaligned(0x45, (unsigned char *)iph); 442 iph->tos = 0; 443 put_unaligned(htons(ip_len), &(iph->tot_len)); 444 iph->id = htons(atomic_inc_return(&ip_ident)); 445 iph->frag_off = 0; 446 iph->ttl = 64; 447 iph->protocol = IPPROTO_UDP; 448 iph->check = 0; 449 put_unaligned(np->local_ip.ip, &(iph->saddr)); 450 put_unaligned(np->remote_ip.ip, &(iph->daddr)); 451 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); 452 453 eth = skb_push(skb, ETH_HLEN); 454 skb_reset_mac_header(skb); 455 skb->protocol = eth->h_proto = htons(ETH_P_IP); 456 } 457 458 ether_addr_copy(eth->h_source, np->dev->dev_addr); 459 ether_addr_copy(eth->h_dest, np->remote_mac); 460 461 skb->dev = np->dev; 462 463 netpoll_send_skb(np, skb); 464 } 465 EXPORT_SYMBOL(netpoll_send_udp); 466 467 void netpoll_print_options(struct netpoll *np) 468 { 469 np_info(np, "local port %d\n", np->local_port); 470 if (np->ipv6) 471 np_info(np, "local IPv6 address %pI6c\n", &np->local_ip.in6); 472 else 473 np_info(np, "local IPv4 address %pI4\n", &np->local_ip.ip); 474 np_info(np, "interface '%s'\n", np->dev_name); 475 np_info(np, "remote port %d\n", np->remote_port); 476 if (np->ipv6) 477 np_info(np, "remote IPv6 address %pI6c\n", &np->remote_ip.in6); 478 else 479 np_info(np, "remote IPv4 address %pI4\n", &np->remote_ip.ip); 480 np_info(np, "remote ethernet address %pM\n", np->remote_mac); 481 } 482 EXPORT_SYMBOL(netpoll_print_options); 483 484 static int netpoll_parse_ip_addr(const char *str, union inet_addr *addr) 485 { 486 const char *end; 487 488 if (!strchr(str, ':') && 489 in4_pton(str, -1, (void *)addr, -1, &end) > 0) { 490 if (!*end) 491 return 0; 492 } 493 if (in6_pton(str, -1, addr->in6.s6_addr, -1, &end) > 0) { 494 #if IS_ENABLED(CONFIG_IPV6) 495 if (!*end) 496 return 1; 497 #else 498 return -1; 499 #endif 500 } 501 return -1; 502 } 503 504 int netpoll_parse_options(struct netpoll *np, char *opt) 505 { 506 char *cur=opt, *delim; 507 int ipv6; 508 bool ipversion_set = false; 509 510 if (*cur != '@') { 511 if ((delim = strchr(cur, '@')) == NULL) 512 goto parse_failed; 513 *delim = 0; 514 if (kstrtou16(cur, 10, &np->local_port)) 515 goto parse_failed; 516 cur = delim; 517 } 518 cur++; 519 520 if (*cur != '/') { 521 ipversion_set = true; 522 if ((delim = strchr(cur, '/')) == NULL) 523 goto parse_failed; 524 *delim = 0; 525 ipv6 = netpoll_parse_ip_addr(cur, &np->local_ip); 526 if (ipv6 < 0) 527 goto parse_failed; 528 else 529 np->ipv6 = (bool)ipv6; 530 cur = delim; 531 } 532 cur++; 533 534 if (*cur != ',') { 535 /* parse out dev name */ 536 if ((delim = strchr(cur, ',')) == NULL) 537 goto parse_failed; 538 *delim = 0; 539 strlcpy(np->dev_name, cur, sizeof(np->dev_name)); 540 cur = delim; 541 } 542 cur++; 543 544 if (*cur != '@') { 545 /* dst port */ 546 if ((delim = strchr(cur, '@')) == NULL) 547 goto parse_failed; 548 *delim = 0; 549 if (*cur == ' ' || *cur == '\t') 550 np_info(np, "warning: whitespace is not allowed\n"); 551 if (kstrtou16(cur, 10, &np->remote_port)) 552 goto parse_failed; 553 cur = delim; 554 } 555 cur++; 556 557 /* dst ip */ 558 if ((delim = strchr(cur, '/')) == NULL) 559 goto parse_failed; 560 *delim = 0; 561 ipv6 = netpoll_parse_ip_addr(cur, &np->remote_ip); 562 if (ipv6 < 0) 563 goto parse_failed; 564 else if (ipversion_set && np->ipv6 != (bool)ipv6) 565 goto parse_failed; 566 else 567 np->ipv6 = (bool)ipv6; 568 cur = delim + 1; 569 570 if (*cur != 0) { 571 /* MAC address */ 572 if (!mac_pton(cur, np->remote_mac)) 573 goto parse_failed; 574 } 575 576 netpoll_print_options(np); 577 578 return 0; 579 580 parse_failed: 581 np_info(np, "couldn't parse config at '%s'!\n", cur); 582 return -1; 583 } 584 EXPORT_SYMBOL(netpoll_parse_options); 585 586 int __netpoll_setup(struct netpoll *np, struct net_device *ndev) 587 { 588 struct netpoll_info *npinfo; 589 const struct net_device_ops *ops; 590 int err; 591 592 np->dev = ndev; 593 strlcpy(np->dev_name, ndev->name, IFNAMSIZ); 594 INIT_WORK(&np->cleanup_work, netpoll_async_cleanup); 595 596 if (ndev->priv_flags & IFF_DISABLE_NETPOLL) { 597 np_err(np, "%s doesn't support polling, aborting\n", 598 np->dev_name); 599 err = -ENOTSUPP; 600 goto out; 601 } 602 603 if (!ndev->npinfo) { 604 npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL); 605 if (!npinfo) { 606 err = -ENOMEM; 607 goto out; 608 } 609 610 sema_init(&npinfo->dev_lock, 1); 611 skb_queue_head_init(&npinfo->txq); 612 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process); 613 614 refcount_set(&npinfo->refcnt, 1); 615 616 ops = np->dev->netdev_ops; 617 if (ops->ndo_netpoll_setup) { 618 err = ops->ndo_netpoll_setup(ndev, npinfo); 619 if (err) 620 goto free_npinfo; 621 } 622 } else { 623 npinfo = rtnl_dereference(ndev->npinfo); 624 refcount_inc(&npinfo->refcnt); 625 } 626 627 npinfo->netpoll = np; 628 629 /* last thing to do is link it to the net device structure */ 630 rcu_assign_pointer(ndev->npinfo, npinfo); 631 632 return 0; 633 634 free_npinfo: 635 kfree(npinfo); 636 out: 637 return err; 638 } 639 EXPORT_SYMBOL_GPL(__netpoll_setup); 640 641 int netpoll_setup(struct netpoll *np) 642 { 643 struct net_device *ndev = NULL; 644 struct in_device *in_dev; 645 int err; 646 647 rtnl_lock(); 648 if (np->dev_name[0]) { 649 struct net *net = current->nsproxy->net_ns; 650 ndev = __dev_get_by_name(net, np->dev_name); 651 } 652 if (!ndev) { 653 np_err(np, "%s doesn't exist, aborting\n", np->dev_name); 654 err = -ENODEV; 655 goto unlock; 656 } 657 dev_hold(ndev); 658 659 if (netdev_master_upper_dev_get(ndev)) { 660 np_err(np, "%s is a slave device, aborting\n", np->dev_name); 661 err = -EBUSY; 662 goto put; 663 } 664 665 if (!netif_running(ndev)) { 666 unsigned long atmost, atleast; 667 668 np_info(np, "device %s not up yet, forcing it\n", np->dev_name); 669 670 err = dev_open(ndev); 671 672 if (err) { 673 np_err(np, "failed to open %s\n", ndev->name); 674 goto put; 675 } 676 677 rtnl_unlock(); 678 atleast = jiffies + HZ/10; 679 atmost = jiffies + carrier_timeout * HZ; 680 while (!netif_carrier_ok(ndev)) { 681 if (time_after(jiffies, atmost)) { 682 np_notice(np, "timeout waiting for carrier\n"); 683 break; 684 } 685 msleep(1); 686 } 687 688 /* If carrier appears to come up instantly, we don't 689 * trust it and pause so that we don't pump all our 690 * queued console messages into the bitbucket. 691 */ 692 693 if (time_before(jiffies, atleast)) { 694 np_notice(np, "carrier detect appears untrustworthy, waiting 4 seconds\n"); 695 msleep(4000); 696 } 697 rtnl_lock(); 698 } 699 700 if (!np->local_ip.ip) { 701 if (!np->ipv6) { 702 in_dev = __in_dev_get_rtnl(ndev); 703 704 if (!in_dev || !in_dev->ifa_list) { 705 np_err(np, "no IP address for %s, aborting\n", 706 np->dev_name); 707 err = -EDESTADDRREQ; 708 goto put; 709 } 710 711 np->local_ip.ip = in_dev->ifa_list->ifa_local; 712 np_info(np, "local IP %pI4\n", &np->local_ip.ip); 713 } else { 714 #if IS_ENABLED(CONFIG_IPV6) 715 struct inet6_dev *idev; 716 717 err = -EDESTADDRREQ; 718 idev = __in6_dev_get(ndev); 719 if (idev) { 720 struct inet6_ifaddr *ifp; 721 722 read_lock_bh(&idev->lock); 723 list_for_each_entry(ifp, &idev->addr_list, if_list) { 724 if (ipv6_addr_type(&ifp->addr) & IPV6_ADDR_LINKLOCAL) 725 continue; 726 np->local_ip.in6 = ifp->addr; 727 err = 0; 728 break; 729 } 730 read_unlock_bh(&idev->lock); 731 } 732 if (err) { 733 np_err(np, "no IPv6 address for %s, aborting\n", 734 np->dev_name); 735 goto put; 736 } else 737 np_info(np, "local IPv6 %pI6c\n", &np->local_ip.in6); 738 #else 739 np_err(np, "IPv6 is not supported %s, aborting\n", 740 np->dev_name); 741 err = -EINVAL; 742 goto put; 743 #endif 744 } 745 } 746 747 /* fill up the skb queue */ 748 refill_skbs(); 749 750 err = __netpoll_setup(np, ndev); 751 if (err) 752 goto put; 753 754 rtnl_unlock(); 755 return 0; 756 757 put: 758 dev_put(ndev); 759 unlock: 760 rtnl_unlock(); 761 return err; 762 } 763 EXPORT_SYMBOL(netpoll_setup); 764 765 static int __init netpoll_init(void) 766 { 767 skb_queue_head_init(&skb_pool); 768 return 0; 769 } 770 core_initcall(netpoll_init); 771 772 static void rcu_cleanup_netpoll_info(struct rcu_head *rcu_head) 773 { 774 struct netpoll_info *npinfo = 775 container_of(rcu_head, struct netpoll_info, rcu); 776 777 skb_queue_purge(&npinfo->txq); 778 779 /* we can't call cancel_delayed_work_sync here, as we are in softirq */ 780 cancel_delayed_work(&npinfo->tx_work); 781 782 /* clean after last, unfinished work */ 783 __skb_queue_purge(&npinfo->txq); 784 /* now cancel it again */ 785 cancel_delayed_work(&npinfo->tx_work); 786 kfree(npinfo); 787 } 788 789 void __netpoll_cleanup(struct netpoll *np) 790 { 791 struct netpoll_info *npinfo; 792 793 /* rtnl_dereference would be preferable here but 794 * rcu_cleanup_netpoll path can put us in here safely without 795 * holding the rtnl, so plain rcu_dereference it is 796 */ 797 npinfo = rtnl_dereference(np->dev->npinfo); 798 if (!npinfo) 799 return; 800 801 synchronize_srcu(&netpoll_srcu); 802 803 if (refcount_dec_and_test(&npinfo->refcnt)) { 804 const struct net_device_ops *ops; 805 806 ops = np->dev->netdev_ops; 807 if (ops->ndo_netpoll_cleanup) 808 ops->ndo_netpoll_cleanup(np->dev); 809 810 RCU_INIT_POINTER(np->dev->npinfo, NULL); 811 call_rcu_bh(&npinfo->rcu, rcu_cleanup_netpoll_info); 812 } else 813 RCU_INIT_POINTER(np->dev->npinfo, NULL); 814 } 815 EXPORT_SYMBOL_GPL(__netpoll_cleanup); 816 817 static void netpoll_async_cleanup(struct work_struct *work) 818 { 819 struct netpoll *np = container_of(work, struct netpoll, cleanup_work); 820 821 rtnl_lock(); 822 __netpoll_cleanup(np); 823 rtnl_unlock(); 824 kfree(np); 825 } 826 827 void __netpoll_free_async(struct netpoll *np) 828 { 829 schedule_work(&np->cleanup_work); 830 } 831 EXPORT_SYMBOL_GPL(__netpoll_free_async); 832 833 void netpoll_cleanup(struct netpoll *np) 834 { 835 rtnl_lock(); 836 if (!np->dev) 837 goto out; 838 __netpoll_cleanup(np); 839 dev_put(np->dev); 840 np->dev = NULL; 841 out: 842 rtnl_unlock(); 843 } 844 EXPORT_SYMBOL(netpoll_cleanup); 845