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 #include <linux/kconfig.h> 40 41 /* 42 * We maintain a small pool of fully-sized skbs, to make sure the 43 * message gets out even in extreme OOM situations. 44 */ 45 46 #define MAX_UDP_CHUNK 1460 47 #define MAX_SKBS 32 48 49 static struct sk_buff_head skb_pool; 50 51 DEFINE_STATIC_SRCU(netpoll_srcu); 52 53 #define USEC_PER_POLL 50 54 55 #define MAX_SKB_SIZE \ 56 (sizeof(struct ethhdr) + \ 57 sizeof(struct iphdr) + \ 58 sizeof(struct udphdr) + \ 59 MAX_UDP_CHUNK) 60 61 static void zap_completion_queue(void); 62 63 static unsigned int carrier_timeout = 4; 64 module_param(carrier_timeout, uint, 0644); 65 66 #define np_info(np, fmt, ...) \ 67 pr_info("%s: " fmt, np->name, ##__VA_ARGS__) 68 #define np_err(np, fmt, ...) \ 69 pr_err("%s: " fmt, np->name, ##__VA_ARGS__) 70 #define np_notice(np, fmt, ...) \ 71 pr_notice("%s: " fmt, np->name, ##__VA_ARGS__) 72 73 static netdev_tx_t netpoll_start_xmit(struct sk_buff *skb, 74 struct net_device *dev, 75 struct netdev_queue *txq) 76 { 77 netdev_tx_t status = NETDEV_TX_OK; 78 netdev_features_t features; 79 80 features = netif_skb_features(skb); 81 82 if (skb_vlan_tag_present(skb) && 83 !vlan_hw_offload_capable(features, skb->vlan_proto)) { 84 skb = __vlan_hwaccel_push_inside(skb); 85 if (unlikely(!skb)) { 86 /* This is actually a packet drop, but we 87 * don't want the code that calls this 88 * function to try and operate on a NULL skb. 89 */ 90 goto out; 91 } 92 } 93 94 status = netdev_start_xmit(skb, dev, txq, false); 95 96 out: 97 return status; 98 } 99 100 static void queue_process(struct work_struct *work) 101 { 102 struct netpoll_info *npinfo = 103 container_of(work, struct netpoll_info, tx_work.work); 104 struct sk_buff *skb; 105 unsigned long flags; 106 107 while ((skb = skb_dequeue(&npinfo->txq))) { 108 struct net_device *dev = skb->dev; 109 struct netdev_queue *txq; 110 unsigned int q_index; 111 112 if (!netif_device_present(dev) || !netif_running(dev)) { 113 kfree_skb(skb); 114 continue; 115 } 116 117 local_irq_save(flags); 118 /* check if skb->queue_mapping is still valid */ 119 q_index = skb_get_queue_mapping(skb); 120 if (unlikely(q_index >= dev->real_num_tx_queues)) { 121 q_index = q_index % dev->real_num_tx_queues; 122 skb_set_queue_mapping(skb, q_index); 123 } 124 txq = netdev_get_tx_queue(dev, q_index); 125 HARD_TX_LOCK(dev, txq, smp_processor_id()); 126 if (netif_xmit_frozen_or_stopped(txq) || 127 !dev_xmit_complete(netpoll_start_xmit(skb, dev, txq))) { 128 skb_queue_head(&npinfo->txq, skb); 129 HARD_TX_UNLOCK(dev, txq); 130 local_irq_restore(flags); 131 132 schedule_delayed_work(&npinfo->tx_work, HZ/10); 133 return; 134 } 135 HARD_TX_UNLOCK(dev, txq); 136 local_irq_restore(flags); 137 } 138 } 139 140 static void poll_one_napi(struct napi_struct *napi) 141 { 142 int work; 143 144 /* If we set this bit but see that it has already been set, 145 * that indicates that napi has been disabled and we need 146 * to abort this operation 147 */ 148 if (test_and_set_bit(NAPI_STATE_NPSVC, &napi->state)) 149 return; 150 151 /* We explicilty pass the polling call a budget of 0 to 152 * indicate that we are clearing the Tx path only. 153 */ 154 work = napi->poll(napi, 0); 155 WARN_ONCE(work, "%pS exceeded budget in poll\n", napi->poll); 156 trace_napi_poll(napi, work, 0); 157 158 clear_bit(NAPI_STATE_NPSVC, &napi->state); 159 } 160 161 static void poll_napi(struct net_device *dev) 162 { 163 struct napi_struct *napi; 164 int cpu = smp_processor_id(); 165 166 list_for_each_entry_rcu(napi, &dev->napi_list, dev_list) { 167 if (cmpxchg(&napi->poll_owner, -1, cpu) == -1) { 168 poll_one_napi(napi); 169 smp_store_release(&napi->poll_owner, -1); 170 } 171 } 172 } 173 174 void netpoll_poll_dev(struct net_device *dev) 175 { 176 struct netpoll_info *ni = rcu_dereference_bh(dev->npinfo); 177 const struct net_device_ops *ops; 178 179 /* Don't do any rx activity if the dev_lock mutex is held 180 * the dev_open/close paths use this to block netpoll activity 181 * while changing device state 182 */ 183 if (!ni || down_trylock(&ni->dev_lock)) 184 return; 185 186 if (!netif_running(dev)) { 187 up(&ni->dev_lock); 188 return; 189 } 190 191 ops = dev->netdev_ops; 192 if (ops->ndo_poll_controller) 193 ops->ndo_poll_controller(dev); 194 195 poll_napi(dev); 196 197 up(&ni->dev_lock); 198 199 zap_completion_queue(); 200 } 201 EXPORT_SYMBOL(netpoll_poll_dev); 202 203 void netpoll_poll_disable(struct net_device *dev) 204 { 205 struct netpoll_info *ni; 206 int idx; 207 might_sleep(); 208 idx = srcu_read_lock(&netpoll_srcu); 209 ni = srcu_dereference(dev->npinfo, &netpoll_srcu); 210 if (ni) 211 down(&ni->dev_lock); 212 srcu_read_unlock(&netpoll_srcu, idx); 213 } 214 EXPORT_SYMBOL(netpoll_poll_disable); 215 216 void netpoll_poll_enable(struct net_device *dev) 217 { 218 struct netpoll_info *ni; 219 rcu_read_lock(); 220 ni = rcu_dereference(dev->npinfo); 221 if (ni) 222 up(&ni->dev_lock); 223 rcu_read_unlock(); 224 } 225 EXPORT_SYMBOL(netpoll_poll_enable); 226 227 static void refill_skbs(void) 228 { 229 struct sk_buff *skb; 230 unsigned long flags; 231 232 spin_lock_irqsave(&skb_pool.lock, flags); 233 while (skb_pool.qlen < MAX_SKBS) { 234 skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC); 235 if (!skb) 236 break; 237 238 __skb_queue_tail(&skb_pool, skb); 239 } 240 spin_unlock_irqrestore(&skb_pool.lock, flags); 241 } 242 243 static void zap_completion_queue(void) 244 { 245 unsigned long flags; 246 struct softnet_data *sd = &get_cpu_var(softnet_data); 247 248 if (sd->completion_queue) { 249 struct sk_buff *clist; 250 251 local_irq_save(flags); 252 clist = sd->completion_queue; 253 sd->completion_queue = NULL; 254 local_irq_restore(flags); 255 256 while (clist != NULL) { 257 struct sk_buff *skb = clist; 258 clist = clist->next; 259 if (!skb_irq_freeable(skb)) { 260 refcount_set(&skb->users, 1); 261 dev_kfree_skb_any(skb); /* put this one back */ 262 } else { 263 __kfree_skb(skb); 264 } 265 } 266 } 267 268 put_cpu_var(softnet_data); 269 } 270 271 static struct sk_buff *find_skb(struct netpoll *np, int len, int reserve) 272 { 273 int count = 0; 274 struct sk_buff *skb; 275 276 zap_completion_queue(); 277 refill_skbs(); 278 repeat: 279 280 skb = alloc_skb(len, GFP_ATOMIC); 281 if (!skb) 282 skb = skb_dequeue(&skb_pool); 283 284 if (!skb) { 285 if (++count < 10) { 286 netpoll_poll_dev(np->dev); 287 goto repeat; 288 } 289 return NULL; 290 } 291 292 refcount_set(&skb->users, 1); 293 skb_reserve(skb, reserve); 294 return skb; 295 } 296 297 static int netpoll_owner_active(struct net_device *dev) 298 { 299 struct napi_struct *napi; 300 301 list_for_each_entry_rcu(napi, &dev->napi_list, dev_list) { 302 if (napi->poll_owner == smp_processor_id()) 303 return 1; 304 } 305 return 0; 306 } 307 308 /* call with IRQ disabled */ 309 static netdev_tx_t __netpoll_send_skb(struct netpoll *np, struct sk_buff *skb) 310 { 311 netdev_tx_t status = NETDEV_TX_BUSY; 312 struct net_device *dev; 313 unsigned long tries; 314 /* It is up to the caller to keep npinfo alive. */ 315 struct netpoll_info *npinfo; 316 317 lockdep_assert_irqs_disabled(); 318 319 dev = np->dev; 320 npinfo = rcu_dereference_bh(dev->npinfo); 321 322 if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) { 323 dev_kfree_skb_irq(skb); 324 return NET_XMIT_DROP; 325 } 326 327 /* don't get messages out of order, and no recursion */ 328 if (skb_queue_len(&npinfo->txq) == 0 && !netpoll_owner_active(dev)) { 329 struct netdev_queue *txq; 330 331 txq = netdev_core_pick_tx(dev, skb, NULL); 332 333 /* try until next clock tick */ 334 for (tries = jiffies_to_usecs(1)/USEC_PER_POLL; 335 tries > 0; --tries) { 336 if (HARD_TX_TRYLOCK(dev, txq)) { 337 if (!netif_xmit_stopped(txq)) 338 status = netpoll_start_xmit(skb, dev, txq); 339 340 HARD_TX_UNLOCK(dev, txq); 341 342 if (dev_xmit_complete(status)) 343 break; 344 345 } 346 347 /* tickle device maybe there is some cleanup */ 348 netpoll_poll_dev(np->dev); 349 350 udelay(USEC_PER_POLL); 351 } 352 353 WARN_ONCE(!irqs_disabled(), 354 "netpoll_send_skb_on_dev(): %s enabled interrupts in poll (%pS)\n", 355 dev->name, dev->netdev_ops->ndo_start_xmit); 356 357 } 358 359 if (!dev_xmit_complete(status)) { 360 skb_queue_tail(&npinfo->txq, skb); 361 schedule_delayed_work(&npinfo->tx_work,0); 362 } 363 return NETDEV_TX_OK; 364 } 365 366 netdev_tx_t netpoll_send_skb(struct netpoll *np, struct sk_buff *skb) 367 { 368 unsigned long flags; 369 netdev_tx_t ret; 370 371 if (unlikely(!np)) { 372 dev_kfree_skb_irq(skb); 373 ret = NET_XMIT_DROP; 374 } else { 375 local_irq_save(flags); 376 ret = __netpoll_send_skb(np, skb); 377 local_irq_restore(flags); 378 } 379 return ret; 380 } 381 EXPORT_SYMBOL(netpoll_send_skb); 382 383 void netpoll_send_udp(struct netpoll *np, const char *msg, int len) 384 { 385 int total_len, ip_len, udp_len; 386 struct sk_buff *skb; 387 struct udphdr *udph; 388 struct iphdr *iph; 389 struct ethhdr *eth; 390 static atomic_t ip_ident; 391 struct ipv6hdr *ip6h; 392 393 if (!IS_ENABLED(CONFIG_PREEMPT_RT)) 394 WARN_ON_ONCE(!irqs_disabled()); 395 396 udp_len = len + sizeof(*udph); 397 if (np->ipv6) 398 ip_len = udp_len + sizeof(*ip6h); 399 else 400 ip_len = udp_len + sizeof(*iph); 401 402 total_len = ip_len + LL_RESERVED_SPACE(np->dev); 403 404 skb = find_skb(np, total_len + np->dev->needed_tailroom, 405 total_len - len); 406 if (!skb) 407 return; 408 409 skb_copy_to_linear_data(skb, msg, len); 410 skb_put(skb, len); 411 412 skb_push(skb, sizeof(*udph)); 413 skb_reset_transport_header(skb); 414 udph = udp_hdr(skb); 415 udph->source = htons(np->local_port); 416 udph->dest = htons(np->remote_port); 417 udph->len = htons(udp_len); 418 419 if (np->ipv6) { 420 udph->check = 0; 421 udph->check = csum_ipv6_magic(&np->local_ip.in6, 422 &np->remote_ip.in6, 423 udp_len, IPPROTO_UDP, 424 csum_partial(udph, udp_len, 0)); 425 if (udph->check == 0) 426 udph->check = CSUM_MANGLED_0; 427 428 skb_push(skb, sizeof(*ip6h)); 429 skb_reset_network_header(skb); 430 ip6h = ipv6_hdr(skb); 431 432 /* ip6h->version = 6; ip6h->priority = 0; */ 433 *(unsigned char *)ip6h = 0x60; 434 ip6h->flow_lbl[0] = 0; 435 ip6h->flow_lbl[1] = 0; 436 ip6h->flow_lbl[2] = 0; 437 438 ip6h->payload_len = htons(sizeof(struct udphdr) + len); 439 ip6h->nexthdr = IPPROTO_UDP; 440 ip6h->hop_limit = 32; 441 ip6h->saddr = np->local_ip.in6; 442 ip6h->daddr = np->remote_ip.in6; 443 444 eth = skb_push(skb, ETH_HLEN); 445 skb_reset_mac_header(skb); 446 skb->protocol = eth->h_proto = htons(ETH_P_IPV6); 447 } else { 448 udph->check = 0; 449 udph->check = csum_tcpudp_magic(np->local_ip.ip, 450 np->remote_ip.ip, 451 udp_len, IPPROTO_UDP, 452 csum_partial(udph, udp_len, 0)); 453 if (udph->check == 0) 454 udph->check = CSUM_MANGLED_0; 455 456 skb_push(skb, sizeof(*iph)); 457 skb_reset_network_header(skb); 458 iph = ip_hdr(skb); 459 460 /* iph->version = 4; iph->ihl = 5; */ 461 *(unsigned char *)iph = 0x45; 462 iph->tos = 0; 463 put_unaligned(htons(ip_len), &(iph->tot_len)); 464 iph->id = htons(atomic_inc_return(&ip_ident)); 465 iph->frag_off = 0; 466 iph->ttl = 64; 467 iph->protocol = IPPROTO_UDP; 468 iph->check = 0; 469 put_unaligned(np->local_ip.ip, &(iph->saddr)); 470 put_unaligned(np->remote_ip.ip, &(iph->daddr)); 471 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); 472 473 eth = skb_push(skb, ETH_HLEN); 474 skb_reset_mac_header(skb); 475 skb->protocol = eth->h_proto = htons(ETH_P_IP); 476 } 477 478 ether_addr_copy(eth->h_source, np->dev->dev_addr); 479 ether_addr_copy(eth->h_dest, np->remote_mac); 480 481 skb->dev = np->dev; 482 483 netpoll_send_skb(np, skb); 484 } 485 EXPORT_SYMBOL(netpoll_send_udp); 486 487 void netpoll_print_options(struct netpoll *np) 488 { 489 np_info(np, "local port %d\n", np->local_port); 490 if (np->ipv6) 491 np_info(np, "local IPv6 address %pI6c\n", &np->local_ip.in6); 492 else 493 np_info(np, "local IPv4 address %pI4\n", &np->local_ip.ip); 494 np_info(np, "interface '%s'\n", np->dev_name); 495 np_info(np, "remote port %d\n", np->remote_port); 496 if (np->ipv6) 497 np_info(np, "remote IPv6 address %pI6c\n", &np->remote_ip.in6); 498 else 499 np_info(np, "remote IPv4 address %pI4\n", &np->remote_ip.ip); 500 np_info(np, "remote ethernet address %pM\n", np->remote_mac); 501 } 502 EXPORT_SYMBOL(netpoll_print_options); 503 504 static int netpoll_parse_ip_addr(const char *str, union inet_addr *addr) 505 { 506 const char *end; 507 508 if (!strchr(str, ':') && 509 in4_pton(str, -1, (void *)addr, -1, &end) > 0) { 510 if (!*end) 511 return 0; 512 } 513 if (in6_pton(str, -1, addr->in6.s6_addr, -1, &end) > 0) { 514 #if IS_ENABLED(CONFIG_IPV6) 515 if (!*end) 516 return 1; 517 #else 518 return -1; 519 #endif 520 } 521 return -1; 522 } 523 524 int netpoll_parse_options(struct netpoll *np, char *opt) 525 { 526 char *cur=opt, *delim; 527 int ipv6; 528 bool ipversion_set = false; 529 530 if (*cur != '@') { 531 if ((delim = strchr(cur, '@')) == NULL) 532 goto parse_failed; 533 *delim = 0; 534 if (kstrtou16(cur, 10, &np->local_port)) 535 goto parse_failed; 536 cur = delim; 537 } 538 cur++; 539 540 if (*cur != '/') { 541 ipversion_set = true; 542 if ((delim = strchr(cur, '/')) == NULL) 543 goto parse_failed; 544 *delim = 0; 545 ipv6 = netpoll_parse_ip_addr(cur, &np->local_ip); 546 if (ipv6 < 0) 547 goto parse_failed; 548 else 549 np->ipv6 = (bool)ipv6; 550 cur = delim; 551 } 552 cur++; 553 554 if (*cur != ',') { 555 /* parse out dev name */ 556 if ((delim = strchr(cur, ',')) == NULL) 557 goto parse_failed; 558 *delim = 0; 559 strlcpy(np->dev_name, cur, sizeof(np->dev_name)); 560 cur = delim; 561 } 562 cur++; 563 564 if (*cur != '@') { 565 /* dst port */ 566 if ((delim = strchr(cur, '@')) == NULL) 567 goto parse_failed; 568 *delim = 0; 569 if (*cur == ' ' || *cur == '\t') 570 np_info(np, "warning: whitespace is not allowed\n"); 571 if (kstrtou16(cur, 10, &np->remote_port)) 572 goto parse_failed; 573 cur = delim; 574 } 575 cur++; 576 577 /* dst ip */ 578 if ((delim = strchr(cur, '/')) == NULL) 579 goto parse_failed; 580 *delim = 0; 581 ipv6 = netpoll_parse_ip_addr(cur, &np->remote_ip); 582 if (ipv6 < 0) 583 goto parse_failed; 584 else if (ipversion_set && np->ipv6 != (bool)ipv6) 585 goto parse_failed; 586 else 587 np->ipv6 = (bool)ipv6; 588 cur = delim + 1; 589 590 if (*cur != 0) { 591 /* MAC address */ 592 if (!mac_pton(cur, np->remote_mac)) 593 goto parse_failed; 594 } 595 596 netpoll_print_options(np); 597 598 return 0; 599 600 parse_failed: 601 np_info(np, "couldn't parse config at '%s'!\n", cur); 602 return -1; 603 } 604 EXPORT_SYMBOL(netpoll_parse_options); 605 606 int __netpoll_setup(struct netpoll *np, struct net_device *ndev) 607 { 608 struct netpoll_info *npinfo; 609 const struct net_device_ops *ops; 610 int err; 611 612 np->dev = ndev; 613 strlcpy(np->dev_name, ndev->name, IFNAMSIZ); 614 615 if (ndev->priv_flags & IFF_DISABLE_NETPOLL) { 616 np_err(np, "%s doesn't support polling, aborting\n", 617 np->dev_name); 618 err = -ENOTSUPP; 619 goto out; 620 } 621 622 if (!ndev->npinfo) { 623 npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL); 624 if (!npinfo) { 625 err = -ENOMEM; 626 goto out; 627 } 628 629 sema_init(&npinfo->dev_lock, 1); 630 skb_queue_head_init(&npinfo->txq); 631 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process); 632 633 refcount_set(&npinfo->refcnt, 1); 634 635 ops = np->dev->netdev_ops; 636 if (ops->ndo_netpoll_setup) { 637 err = ops->ndo_netpoll_setup(ndev, npinfo); 638 if (err) 639 goto free_npinfo; 640 } 641 } else { 642 npinfo = rtnl_dereference(ndev->npinfo); 643 refcount_inc(&npinfo->refcnt); 644 } 645 646 npinfo->netpoll = np; 647 648 /* last thing to do is link it to the net device structure */ 649 rcu_assign_pointer(ndev->npinfo, npinfo); 650 651 return 0; 652 653 free_npinfo: 654 kfree(npinfo); 655 out: 656 return err; 657 } 658 EXPORT_SYMBOL_GPL(__netpoll_setup); 659 660 int netpoll_setup(struct netpoll *np) 661 { 662 struct net_device *ndev = NULL; 663 struct in_device *in_dev; 664 int err; 665 666 rtnl_lock(); 667 if (np->dev_name[0]) { 668 struct net *net = current->nsproxy->net_ns; 669 ndev = __dev_get_by_name(net, np->dev_name); 670 } 671 if (!ndev) { 672 np_err(np, "%s doesn't exist, aborting\n", np->dev_name); 673 err = -ENODEV; 674 goto unlock; 675 } 676 dev_hold(ndev); 677 678 if (netdev_master_upper_dev_get(ndev)) { 679 np_err(np, "%s is a slave device, aborting\n", np->dev_name); 680 err = -EBUSY; 681 goto put; 682 } 683 684 if (!netif_running(ndev)) { 685 unsigned long atmost, atleast; 686 687 np_info(np, "device %s not up yet, forcing it\n", np->dev_name); 688 689 err = dev_open(ndev, NULL); 690 691 if (err) { 692 np_err(np, "failed to open %s\n", ndev->name); 693 goto put; 694 } 695 696 rtnl_unlock(); 697 atleast = jiffies + HZ/10; 698 atmost = jiffies + carrier_timeout * HZ; 699 while (!netif_carrier_ok(ndev)) { 700 if (time_after(jiffies, atmost)) { 701 np_notice(np, "timeout waiting for carrier\n"); 702 break; 703 } 704 msleep(1); 705 } 706 707 /* If carrier appears to come up instantly, we don't 708 * trust it and pause so that we don't pump all our 709 * queued console messages into the bitbucket. 710 */ 711 712 if (time_before(jiffies, atleast)) { 713 np_notice(np, "carrier detect appears untrustworthy, waiting 4 seconds\n"); 714 msleep(4000); 715 } 716 rtnl_lock(); 717 } 718 719 if (!np->local_ip.ip) { 720 if (!np->ipv6) { 721 const struct in_ifaddr *ifa; 722 723 in_dev = __in_dev_get_rtnl(ndev); 724 if (!in_dev) 725 goto put_noaddr; 726 727 ifa = rtnl_dereference(in_dev->ifa_list); 728 if (!ifa) { 729 put_noaddr: 730 np_err(np, "no IP address for %s, aborting\n", 731 np->dev_name); 732 err = -EDESTADDRREQ; 733 goto put; 734 } 735 736 np->local_ip.ip = ifa->ifa_local; 737 np_info(np, "local IP %pI4\n", &np->local_ip.ip); 738 } else { 739 #if IS_ENABLED(CONFIG_IPV6) 740 struct inet6_dev *idev; 741 742 err = -EDESTADDRREQ; 743 idev = __in6_dev_get(ndev); 744 if (idev) { 745 struct inet6_ifaddr *ifp; 746 747 read_lock_bh(&idev->lock); 748 list_for_each_entry(ifp, &idev->addr_list, if_list) { 749 if (!!(ipv6_addr_type(&ifp->addr) & IPV6_ADDR_LINKLOCAL) != 750 !!(ipv6_addr_type(&np->remote_ip.in6) & IPV6_ADDR_LINKLOCAL)) 751 continue; 752 np->local_ip.in6 = ifp->addr; 753 err = 0; 754 break; 755 } 756 read_unlock_bh(&idev->lock); 757 } 758 if (err) { 759 np_err(np, "no IPv6 address for %s, aborting\n", 760 np->dev_name); 761 goto put; 762 } else 763 np_info(np, "local IPv6 %pI6c\n", &np->local_ip.in6); 764 #else 765 np_err(np, "IPv6 is not supported %s, aborting\n", 766 np->dev_name); 767 err = -EINVAL; 768 goto put; 769 #endif 770 } 771 } 772 773 /* fill up the skb queue */ 774 refill_skbs(); 775 776 err = __netpoll_setup(np, ndev); 777 if (err) 778 goto put; 779 netdev_tracker_alloc(ndev, &np->dev_tracker, GFP_KERNEL); 780 rtnl_unlock(); 781 return 0; 782 783 put: 784 dev_put(ndev); 785 unlock: 786 rtnl_unlock(); 787 return err; 788 } 789 EXPORT_SYMBOL(netpoll_setup); 790 791 static int __init netpoll_init(void) 792 { 793 skb_queue_head_init(&skb_pool); 794 return 0; 795 } 796 core_initcall(netpoll_init); 797 798 static void rcu_cleanup_netpoll_info(struct rcu_head *rcu_head) 799 { 800 struct netpoll_info *npinfo = 801 container_of(rcu_head, struct netpoll_info, rcu); 802 803 skb_queue_purge(&npinfo->txq); 804 805 /* we can't call cancel_delayed_work_sync here, as we are in softirq */ 806 cancel_delayed_work(&npinfo->tx_work); 807 808 /* clean after last, unfinished work */ 809 __skb_queue_purge(&npinfo->txq); 810 /* now cancel it again */ 811 cancel_delayed_work(&npinfo->tx_work); 812 kfree(npinfo); 813 } 814 815 void __netpoll_cleanup(struct netpoll *np) 816 { 817 struct netpoll_info *npinfo; 818 819 npinfo = rtnl_dereference(np->dev->npinfo); 820 if (!npinfo) 821 return; 822 823 synchronize_srcu(&netpoll_srcu); 824 825 if (refcount_dec_and_test(&npinfo->refcnt)) { 826 const struct net_device_ops *ops; 827 828 ops = np->dev->netdev_ops; 829 if (ops->ndo_netpoll_cleanup) 830 ops->ndo_netpoll_cleanup(np->dev); 831 832 RCU_INIT_POINTER(np->dev->npinfo, NULL); 833 call_rcu(&npinfo->rcu, rcu_cleanup_netpoll_info); 834 } else 835 RCU_INIT_POINTER(np->dev->npinfo, NULL); 836 } 837 EXPORT_SYMBOL_GPL(__netpoll_cleanup); 838 839 void __netpoll_free(struct netpoll *np) 840 { 841 ASSERT_RTNL(); 842 843 /* Wait for transmitting packets to finish before freeing. */ 844 synchronize_rcu(); 845 __netpoll_cleanup(np); 846 kfree(np); 847 } 848 EXPORT_SYMBOL_GPL(__netpoll_free); 849 850 void netpoll_cleanup(struct netpoll *np) 851 { 852 rtnl_lock(); 853 if (!np->dev) 854 goto out; 855 __netpoll_cleanup(np); 856 dev_put_track(np->dev, &np->dev_tracker); 857 np->dev = NULL; 858 out: 859 rtnl_unlock(); 860 } 861 EXPORT_SYMBOL(netpoll_cleanup); 862