1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Common framework for low-level network console, dump, and debugger code 4 * 5 * Sep 8 2003 Matt Mackall <mpm@selenic.com> 6 * 7 * based on the netconsole code from: 8 * 9 * Copyright (C) 2001 Ingo Molnar <mingo@redhat.com> 10 * Copyright (C) 2002 Red Hat, Inc. 11 */ 12 13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 14 15 #include <linux/moduleparam.h> 16 #include <linux/kernel.h> 17 #include <linux/netdevice.h> 18 #include <linux/etherdevice.h> 19 #include <linux/string.h> 20 #include <linux/if_arp.h> 21 #include <linux/inetdevice.h> 22 #include <linux/inet.h> 23 #include <linux/interrupt.h> 24 #include <linux/netpoll.h> 25 #include <linux/sched.h> 26 #include <linux/delay.h> 27 #include <linux/rcupdate.h> 28 #include <linux/workqueue.h> 29 #include <linux/slab.h> 30 #include <linux/export.h> 31 #include <linux/if_vlan.h> 32 #include <net/tcp.h> 33 #include <net/udp.h> 34 #include <net/addrconf.h> 35 #include <net/ndisc.h> 36 #include <net/ip6_checksum.h> 37 #include <asm/unaligned.h> 38 #include <trace/events/napi.h> 39 40 /* 41 * We maintain a small pool of fully-sized skbs, to make sure the 42 * message gets out even in extreme OOM situations. 43 */ 44 45 #define MAX_UDP_CHUNK 1460 46 #define MAX_SKBS 32 47 48 static struct sk_buff_head skb_pool; 49 50 DEFINE_STATIC_SRCU(netpoll_srcu); 51 52 #define USEC_PER_POLL 50 53 54 #define MAX_SKB_SIZE \ 55 (sizeof(struct ethhdr) + \ 56 sizeof(struct iphdr) + \ 57 sizeof(struct udphdr) + \ 58 MAX_UDP_CHUNK) 59 60 static void zap_completion_queue(void); 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 netdev_tx_t netpoll_start_xmit(struct sk_buff *skb, 73 struct net_device *dev, 74 struct netdev_queue *txq) 75 { 76 netdev_tx_t status = NETDEV_TX_OK; 77 netdev_features_t features; 78 79 features = netif_skb_features(skb); 80 81 if (skb_vlan_tag_present(skb) && 82 !vlan_hw_offload_capable(features, skb->vlan_proto)) { 83 skb = __vlan_hwaccel_push_inside(skb); 84 if (unlikely(!skb)) { 85 /* This is actually a packet drop, but we 86 * don't want the code that calls this 87 * function to try and operate on a NULL skb. 88 */ 89 goto out; 90 } 91 } 92 93 status = netdev_start_xmit(skb, dev, txq, false); 94 95 out: 96 return status; 97 } 98 99 static void queue_process(struct work_struct *work) 100 { 101 struct netpoll_info *npinfo = 102 container_of(work, struct netpoll_info, tx_work.work); 103 struct sk_buff *skb; 104 unsigned long flags; 105 106 while ((skb = skb_dequeue(&npinfo->txq))) { 107 struct net_device *dev = skb->dev; 108 struct netdev_queue *txq; 109 unsigned int q_index; 110 111 if (!netif_device_present(dev) || !netif_running(dev)) { 112 kfree_skb(skb); 113 continue; 114 } 115 116 local_irq_save(flags); 117 /* check if skb->queue_mapping is still valid */ 118 q_index = skb_get_queue_mapping(skb); 119 if (unlikely(q_index >= dev->real_num_tx_queues)) { 120 q_index = q_index % dev->real_num_tx_queues; 121 skb_set_queue_mapping(skb, q_index); 122 } 123 txq = netdev_get_tx_queue(dev, q_index); 124 HARD_TX_LOCK(dev, txq, smp_processor_id()); 125 if (netif_xmit_frozen_or_stopped(txq) || 126 !dev_xmit_complete(netpoll_start_xmit(skb, dev, txq))) { 127 skb_queue_head(&npinfo->txq, skb); 128 HARD_TX_UNLOCK(dev, txq); 129 local_irq_restore(flags); 130 131 schedule_delayed_work(&npinfo->tx_work, HZ/10); 132 return; 133 } 134 HARD_TX_UNLOCK(dev, txq); 135 local_irq_restore(flags); 136 } 137 } 138 139 static void poll_one_napi(struct napi_struct *napi) 140 { 141 int work; 142 143 /* If we set this bit but see that it has already been set, 144 * that indicates that napi has been disabled and we need 145 * to abort this operation 146 */ 147 if (test_and_set_bit(NAPI_STATE_NPSVC, &napi->state)) 148 return; 149 150 /* We explicilty pass the polling call a budget of 0 to 151 * indicate that we are clearing the Tx path only. 152 */ 153 work = napi->poll(napi, 0); 154 WARN_ONCE(work, "%pS exceeded budget in poll\n", napi->poll); 155 trace_napi_poll(napi, work, 0); 156 157 clear_bit(NAPI_STATE_NPSVC, &napi->state); 158 } 159 160 static void poll_napi(struct net_device *dev) 161 { 162 struct napi_struct *napi; 163 int cpu = smp_processor_id(); 164 165 list_for_each_entry(napi, &dev->napi_list, dev_list) { 166 if (cmpxchg(&napi->poll_owner, -1, cpu) == -1) { 167 poll_one_napi(napi); 168 smp_store_release(&napi->poll_owner, -1); 169 } 170 } 171 } 172 173 void netpoll_poll_dev(struct net_device *dev) 174 { 175 struct netpoll_info *ni = rcu_dereference_bh(dev->npinfo); 176 const struct net_device_ops *ops; 177 178 /* Don't do any rx activity if the dev_lock mutex is held 179 * the dev_open/close paths use this to block netpoll activity 180 * while changing device state 181 */ 182 if (!ni || down_trylock(&ni->dev_lock)) 183 return; 184 185 if (!netif_running(dev)) { 186 up(&ni->dev_lock); 187 return; 188 } 189 190 ops = dev->netdev_ops; 191 if (ops->ndo_poll_controller) 192 ops->ndo_poll_controller(dev); 193 194 poll_napi(dev); 195 196 up(&ni->dev_lock); 197 198 zap_completion_queue(); 199 } 200 EXPORT_SYMBOL(netpoll_poll_dev); 201 202 void netpoll_poll_disable(struct net_device *dev) 203 { 204 struct netpoll_info *ni; 205 int idx; 206 might_sleep(); 207 idx = srcu_read_lock(&netpoll_srcu); 208 ni = srcu_dereference(dev->npinfo, &netpoll_srcu); 209 if (ni) 210 down(&ni->dev_lock); 211 srcu_read_unlock(&netpoll_srcu, idx); 212 } 213 EXPORT_SYMBOL(netpoll_poll_disable); 214 215 void netpoll_poll_enable(struct net_device *dev) 216 { 217 struct netpoll_info *ni; 218 rcu_read_lock(); 219 ni = rcu_dereference(dev->npinfo); 220 if (ni) 221 up(&ni->dev_lock); 222 rcu_read_unlock(); 223 } 224 EXPORT_SYMBOL(netpoll_poll_enable); 225 226 static void refill_skbs(void) 227 { 228 struct sk_buff *skb; 229 unsigned long flags; 230 231 spin_lock_irqsave(&skb_pool.lock, flags); 232 while (skb_pool.qlen < MAX_SKBS) { 233 skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC); 234 if (!skb) 235 break; 236 237 __skb_queue_tail(&skb_pool, skb); 238 } 239 spin_unlock_irqrestore(&skb_pool.lock, flags); 240 } 241 242 static void zap_completion_queue(void) 243 { 244 unsigned long flags; 245 struct softnet_data *sd = &get_cpu_var(softnet_data); 246 247 if (sd->completion_queue) { 248 struct sk_buff *clist; 249 250 local_irq_save(flags); 251 clist = sd->completion_queue; 252 sd->completion_queue = NULL; 253 local_irq_restore(flags); 254 255 while (clist != NULL) { 256 struct sk_buff *skb = clist; 257 clist = clist->next; 258 if (!skb_irq_freeable(skb)) { 259 refcount_set(&skb->users, 1); 260 dev_kfree_skb_any(skb); /* put this one back */ 261 } else { 262 __kfree_skb(skb); 263 } 264 } 265 } 266 267 put_cpu_var(softnet_data); 268 } 269 270 static struct sk_buff *find_skb(struct netpoll *np, int len, int reserve) 271 { 272 int count = 0; 273 struct sk_buff *skb; 274 275 zap_completion_queue(); 276 refill_skbs(); 277 repeat: 278 279 skb = alloc_skb(len, GFP_ATOMIC); 280 if (!skb) 281 skb = skb_dequeue(&skb_pool); 282 283 if (!skb) { 284 if (++count < 10) { 285 netpoll_poll_dev(np->dev); 286 goto repeat; 287 } 288 return NULL; 289 } 290 291 refcount_set(&skb->users, 1); 292 skb_reserve(skb, reserve); 293 return skb; 294 } 295 296 static int netpoll_owner_active(struct net_device *dev) 297 { 298 struct napi_struct *napi; 299 300 list_for_each_entry(napi, &dev->napi_list, dev_list) { 301 if (napi->poll_owner == smp_processor_id()) 302 return 1; 303 } 304 return 0; 305 } 306 307 /* call with IRQ disabled */ 308 void netpoll_send_skb_on_dev(struct netpoll *np, struct sk_buff *skb, 309 struct net_device *dev) 310 { 311 netdev_tx_t status = NETDEV_TX_BUSY; 312 unsigned long tries; 313 /* It is up to the caller to keep npinfo alive. */ 314 struct netpoll_info *npinfo; 315 316 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_core_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 (dev_xmit_complete(status)) 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 (%pS)\n", 352 dev->name, dev->netdev_ops->ndo_start_xmit); 353 354 } 355 356 if (!dev_xmit_complete(status)) { 357 skb_queue_tail(&npinfo->txq, skb); 358 schedule_delayed_work(&npinfo->tx_work,0); 359 } 360 } 361 EXPORT_SYMBOL(netpoll_send_skb_on_dev); 362 363 void netpoll_send_udp(struct netpoll *np, const char *msg, int len) 364 { 365 int total_len, ip_len, udp_len; 366 struct sk_buff *skb; 367 struct udphdr *udph; 368 struct iphdr *iph; 369 struct ethhdr *eth; 370 static atomic_t ip_ident; 371 struct ipv6hdr *ip6h; 372 373 WARN_ON_ONCE(!irqs_disabled()); 374 375 udp_len = len + sizeof(*udph); 376 if (np->ipv6) 377 ip_len = udp_len + sizeof(*ip6h); 378 else 379 ip_len = udp_len + sizeof(*iph); 380 381 total_len = ip_len + LL_RESERVED_SPACE(np->dev); 382 383 skb = find_skb(np, total_len + np->dev->needed_tailroom, 384 total_len - len); 385 if (!skb) 386 return; 387 388 skb_copy_to_linear_data(skb, msg, len); 389 skb_put(skb, len); 390 391 skb_push(skb, sizeof(*udph)); 392 skb_reset_transport_header(skb); 393 udph = udp_hdr(skb); 394 udph->source = htons(np->local_port); 395 udph->dest = htons(np->remote_port); 396 udph->len = htons(udp_len); 397 398 if (np->ipv6) { 399 udph->check = 0; 400 udph->check = csum_ipv6_magic(&np->local_ip.in6, 401 &np->remote_ip.in6, 402 udp_len, IPPROTO_UDP, 403 csum_partial(udph, udp_len, 0)); 404 if (udph->check == 0) 405 udph->check = CSUM_MANGLED_0; 406 407 skb_push(skb, sizeof(*ip6h)); 408 skb_reset_network_header(skb); 409 ip6h = ipv6_hdr(skb); 410 411 /* ip6h->version = 6; ip6h->priority = 0; */ 412 put_unaligned(0x60, (unsigned char *)ip6h); 413 ip6h->flow_lbl[0] = 0; 414 ip6h->flow_lbl[1] = 0; 415 ip6h->flow_lbl[2] = 0; 416 417 ip6h->payload_len = htons(sizeof(struct udphdr) + len); 418 ip6h->nexthdr = IPPROTO_UDP; 419 ip6h->hop_limit = 32; 420 ip6h->saddr = np->local_ip.in6; 421 ip6h->daddr = np->remote_ip.in6; 422 423 eth = skb_push(skb, ETH_HLEN); 424 skb_reset_mac_header(skb); 425 skb->protocol = eth->h_proto = htons(ETH_P_IPV6); 426 } else { 427 udph->check = 0; 428 udph->check = csum_tcpudp_magic(np->local_ip.ip, 429 np->remote_ip.ip, 430 udp_len, IPPROTO_UDP, 431 csum_partial(udph, udp_len, 0)); 432 if (udph->check == 0) 433 udph->check = CSUM_MANGLED_0; 434 435 skb_push(skb, sizeof(*iph)); 436 skb_reset_network_header(skb); 437 iph = ip_hdr(skb); 438 439 /* iph->version = 4; iph->ihl = 5; */ 440 put_unaligned(0x45, (unsigned char *)iph); 441 iph->tos = 0; 442 put_unaligned(htons(ip_len), &(iph->tot_len)); 443 iph->id = htons(atomic_inc_return(&ip_ident)); 444 iph->frag_off = 0; 445 iph->ttl = 64; 446 iph->protocol = IPPROTO_UDP; 447 iph->check = 0; 448 put_unaligned(np->local_ip.ip, &(iph->saddr)); 449 put_unaligned(np->remote_ip.ip, &(iph->daddr)); 450 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); 451 452 eth = skb_push(skb, ETH_HLEN); 453 skb_reset_mac_header(skb); 454 skb->protocol = eth->h_proto = htons(ETH_P_IP); 455 } 456 457 ether_addr_copy(eth->h_source, np->dev->dev_addr); 458 ether_addr_copy(eth->h_dest, np->remote_mac); 459 460 skb->dev = np->dev; 461 462 netpoll_send_skb(np, skb); 463 } 464 EXPORT_SYMBOL(netpoll_send_udp); 465 466 void netpoll_print_options(struct netpoll *np) 467 { 468 np_info(np, "local port %d\n", np->local_port); 469 if (np->ipv6) 470 np_info(np, "local IPv6 address %pI6c\n", &np->local_ip.in6); 471 else 472 np_info(np, "local IPv4 address %pI4\n", &np->local_ip.ip); 473 np_info(np, "interface '%s'\n", np->dev_name); 474 np_info(np, "remote port %d\n", np->remote_port); 475 if (np->ipv6) 476 np_info(np, "remote IPv6 address %pI6c\n", &np->remote_ip.in6); 477 else 478 np_info(np, "remote IPv4 address %pI4\n", &np->remote_ip.ip); 479 np_info(np, "remote ethernet address %pM\n", np->remote_mac); 480 } 481 EXPORT_SYMBOL(netpoll_print_options); 482 483 static int netpoll_parse_ip_addr(const char *str, union inet_addr *addr) 484 { 485 const char *end; 486 487 if (!strchr(str, ':') && 488 in4_pton(str, -1, (void *)addr, -1, &end) > 0) { 489 if (!*end) 490 return 0; 491 } 492 if (in6_pton(str, -1, addr->in6.s6_addr, -1, &end) > 0) { 493 #if IS_ENABLED(CONFIG_IPV6) 494 if (!*end) 495 return 1; 496 #else 497 return -1; 498 #endif 499 } 500 return -1; 501 } 502 503 int netpoll_parse_options(struct netpoll *np, char *opt) 504 { 505 char *cur=opt, *delim; 506 int ipv6; 507 bool ipversion_set = false; 508 509 if (*cur != '@') { 510 if ((delim = strchr(cur, '@')) == NULL) 511 goto parse_failed; 512 *delim = 0; 513 if (kstrtou16(cur, 10, &np->local_port)) 514 goto parse_failed; 515 cur = delim; 516 } 517 cur++; 518 519 if (*cur != '/') { 520 ipversion_set = true; 521 if ((delim = strchr(cur, '/')) == NULL) 522 goto parse_failed; 523 *delim = 0; 524 ipv6 = netpoll_parse_ip_addr(cur, &np->local_ip); 525 if (ipv6 < 0) 526 goto parse_failed; 527 else 528 np->ipv6 = (bool)ipv6; 529 cur = delim; 530 } 531 cur++; 532 533 if (*cur != ',') { 534 /* parse out dev name */ 535 if ((delim = strchr(cur, ',')) == NULL) 536 goto parse_failed; 537 *delim = 0; 538 strlcpy(np->dev_name, cur, sizeof(np->dev_name)); 539 cur = delim; 540 } 541 cur++; 542 543 if (*cur != '@') { 544 /* dst port */ 545 if ((delim = strchr(cur, '@')) == NULL) 546 goto parse_failed; 547 *delim = 0; 548 if (*cur == ' ' || *cur == '\t') 549 np_info(np, "warning: whitespace is not allowed\n"); 550 if (kstrtou16(cur, 10, &np->remote_port)) 551 goto parse_failed; 552 cur = delim; 553 } 554 cur++; 555 556 /* dst ip */ 557 if ((delim = strchr(cur, '/')) == NULL) 558 goto parse_failed; 559 *delim = 0; 560 ipv6 = netpoll_parse_ip_addr(cur, &np->remote_ip); 561 if (ipv6 < 0) 562 goto parse_failed; 563 else if (ipversion_set && np->ipv6 != (bool)ipv6) 564 goto parse_failed; 565 else 566 np->ipv6 = (bool)ipv6; 567 cur = delim + 1; 568 569 if (*cur != 0) { 570 /* MAC address */ 571 if (!mac_pton(cur, np->remote_mac)) 572 goto parse_failed; 573 } 574 575 netpoll_print_options(np); 576 577 return 0; 578 579 parse_failed: 580 np_info(np, "couldn't parse config at '%s'!\n", cur); 581 return -1; 582 } 583 EXPORT_SYMBOL(netpoll_parse_options); 584 585 int __netpoll_setup(struct netpoll *np, struct net_device *ndev) 586 { 587 struct netpoll_info *npinfo; 588 const struct net_device_ops *ops; 589 int err; 590 591 np->dev = ndev; 592 strlcpy(np->dev_name, ndev->name, IFNAMSIZ); 593 594 if (ndev->priv_flags & IFF_DISABLE_NETPOLL) { 595 np_err(np, "%s doesn't support polling, aborting\n", 596 np->dev_name); 597 err = -ENOTSUPP; 598 goto out; 599 } 600 601 if (!ndev->npinfo) { 602 npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL); 603 if (!npinfo) { 604 err = -ENOMEM; 605 goto out; 606 } 607 608 sema_init(&npinfo->dev_lock, 1); 609 skb_queue_head_init(&npinfo->txq); 610 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process); 611 612 refcount_set(&npinfo->refcnt, 1); 613 614 ops = np->dev->netdev_ops; 615 if (ops->ndo_netpoll_setup) { 616 err = ops->ndo_netpoll_setup(ndev, npinfo); 617 if (err) 618 goto free_npinfo; 619 } 620 } else { 621 npinfo = rtnl_dereference(ndev->npinfo); 622 refcount_inc(&npinfo->refcnt); 623 } 624 625 npinfo->netpoll = np; 626 627 /* last thing to do is link it to the net device structure */ 628 rcu_assign_pointer(ndev->npinfo, npinfo); 629 630 return 0; 631 632 free_npinfo: 633 kfree(npinfo); 634 out: 635 return err; 636 } 637 EXPORT_SYMBOL_GPL(__netpoll_setup); 638 639 int netpoll_setup(struct netpoll *np) 640 { 641 struct net_device *ndev = NULL; 642 struct in_device *in_dev; 643 int err; 644 645 rtnl_lock(); 646 if (np->dev_name[0]) { 647 struct net *net = current->nsproxy->net_ns; 648 ndev = __dev_get_by_name(net, np->dev_name); 649 } 650 if (!ndev) { 651 np_err(np, "%s doesn't exist, aborting\n", np->dev_name); 652 err = -ENODEV; 653 goto unlock; 654 } 655 dev_hold(ndev); 656 657 if (netdev_master_upper_dev_get(ndev)) { 658 np_err(np, "%s is a slave device, aborting\n", np->dev_name); 659 err = -EBUSY; 660 goto put; 661 } 662 663 if (!netif_running(ndev)) { 664 unsigned long atmost, atleast; 665 666 np_info(np, "device %s not up yet, forcing it\n", np->dev_name); 667 668 err = dev_open(ndev, NULL); 669 670 if (err) { 671 np_err(np, "failed to open %s\n", ndev->name); 672 goto put; 673 } 674 675 rtnl_unlock(); 676 atleast = jiffies + HZ/10; 677 atmost = jiffies + carrier_timeout * HZ; 678 while (!netif_carrier_ok(ndev)) { 679 if (time_after(jiffies, atmost)) { 680 np_notice(np, "timeout waiting for carrier\n"); 681 break; 682 } 683 msleep(1); 684 } 685 686 /* If carrier appears to come up instantly, we don't 687 * trust it and pause so that we don't pump all our 688 * queued console messages into the bitbucket. 689 */ 690 691 if (time_before(jiffies, atleast)) { 692 np_notice(np, "carrier detect appears untrustworthy, waiting 4 seconds\n"); 693 msleep(4000); 694 } 695 rtnl_lock(); 696 } 697 698 if (!np->local_ip.ip) { 699 if (!np->ipv6) { 700 const struct in_ifaddr *ifa; 701 702 in_dev = __in_dev_get_rtnl(ndev); 703 if (!in_dev) 704 goto put_noaddr; 705 706 ifa = rtnl_dereference(in_dev->ifa_list); 707 if (!ifa) { 708 put_noaddr: 709 np_err(np, "no IP address for %s, aborting\n", 710 np->dev_name); 711 err = -EDESTADDRREQ; 712 goto put; 713 } 714 715 np->local_ip.ip = ifa->ifa_local; 716 np_info(np, "local IP %pI4\n", &np->local_ip.ip); 717 } else { 718 #if IS_ENABLED(CONFIG_IPV6) 719 struct inet6_dev *idev; 720 721 err = -EDESTADDRREQ; 722 idev = __in6_dev_get(ndev); 723 if (idev) { 724 struct inet6_ifaddr *ifp; 725 726 read_lock_bh(&idev->lock); 727 list_for_each_entry(ifp, &idev->addr_list, if_list) { 728 if (!!(ipv6_addr_type(&ifp->addr) & IPV6_ADDR_LINKLOCAL) != 729 !!(ipv6_addr_type(&np->remote_ip.in6) & IPV6_ADDR_LINKLOCAL)) 730 continue; 731 np->local_ip.in6 = ifp->addr; 732 err = 0; 733 break; 734 } 735 read_unlock_bh(&idev->lock); 736 } 737 if (err) { 738 np_err(np, "no IPv6 address for %s, aborting\n", 739 np->dev_name); 740 goto put; 741 } else 742 np_info(np, "local IPv6 %pI6c\n", &np->local_ip.in6); 743 #else 744 np_err(np, "IPv6 is not supported %s, aborting\n", 745 np->dev_name); 746 err = -EINVAL; 747 goto put; 748 #endif 749 } 750 } 751 752 /* fill up the skb queue */ 753 refill_skbs(); 754 755 err = __netpoll_setup(np, ndev); 756 if (err) 757 goto put; 758 759 rtnl_unlock(); 760 return 0; 761 762 put: 763 dev_put(ndev); 764 unlock: 765 rtnl_unlock(); 766 return err; 767 } 768 EXPORT_SYMBOL(netpoll_setup); 769 770 static int __init netpoll_init(void) 771 { 772 skb_queue_head_init(&skb_pool); 773 return 0; 774 } 775 core_initcall(netpoll_init); 776 777 static void rcu_cleanup_netpoll_info(struct rcu_head *rcu_head) 778 { 779 struct netpoll_info *npinfo = 780 container_of(rcu_head, struct netpoll_info, rcu); 781 782 skb_queue_purge(&npinfo->txq); 783 784 /* we can't call cancel_delayed_work_sync here, as we are in softirq */ 785 cancel_delayed_work(&npinfo->tx_work); 786 787 /* clean after last, unfinished work */ 788 __skb_queue_purge(&npinfo->txq); 789 /* now cancel it again */ 790 cancel_delayed_work(&npinfo->tx_work); 791 kfree(npinfo); 792 } 793 794 void __netpoll_cleanup(struct netpoll *np) 795 { 796 struct netpoll_info *npinfo; 797 798 npinfo = rtnl_dereference(np->dev->npinfo); 799 if (!npinfo) 800 return; 801 802 synchronize_srcu(&netpoll_srcu); 803 804 if (refcount_dec_and_test(&npinfo->refcnt)) { 805 const struct net_device_ops *ops; 806 807 ops = np->dev->netdev_ops; 808 if (ops->ndo_netpoll_cleanup) 809 ops->ndo_netpoll_cleanup(np->dev); 810 811 RCU_INIT_POINTER(np->dev->npinfo, NULL); 812 call_rcu(&npinfo->rcu, rcu_cleanup_netpoll_info); 813 } else 814 RCU_INIT_POINTER(np->dev->npinfo, NULL); 815 } 816 EXPORT_SYMBOL_GPL(__netpoll_cleanup); 817 818 void __netpoll_free(struct netpoll *np) 819 { 820 ASSERT_RTNL(); 821 822 /* Wait for transmitting packets to finish before freeing. */ 823 synchronize_rcu(); 824 __netpoll_cleanup(np); 825 kfree(np); 826 } 827 EXPORT_SYMBOL_GPL(__netpoll_free); 828 829 void netpoll_cleanup(struct netpoll *np) 830 { 831 rtnl_lock(); 832 if (!np->dev) 833 goto out; 834 __netpoll_cleanup(np); 835 dev_put(np->dev); 836 np->dev = NULL; 837 out: 838 rtnl_unlock(); 839 } 840 EXPORT_SYMBOL(netpoll_cleanup); 841