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_rcu(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_rcu(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 static netdev_tx_t __netpoll_send_skb(struct netpoll *np, struct sk_buff *skb) 309 { 310 netdev_tx_t status = NETDEV_TX_BUSY; 311 struct net_device *dev; 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 dev = np->dev; 319 npinfo = rcu_dereference_bh(dev->npinfo); 320 321 if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) { 322 dev_kfree_skb_irq(skb); 323 return NET_XMIT_DROP; 324 } 325 326 /* don't get messages out of order, and no recursion */ 327 if (skb_queue_len(&npinfo->txq) == 0 && !netpoll_owner_active(dev)) { 328 struct netdev_queue *txq; 329 330 txq = netdev_core_pick_tx(dev, skb, NULL); 331 332 /* try until next clock tick */ 333 for (tries = jiffies_to_usecs(1)/USEC_PER_POLL; 334 tries > 0; --tries) { 335 if (HARD_TX_TRYLOCK(dev, txq)) { 336 if (!netif_xmit_stopped(txq)) 337 status = netpoll_start_xmit(skb, dev, txq); 338 339 HARD_TX_UNLOCK(dev, txq); 340 341 if (dev_xmit_complete(status)) 342 break; 343 344 } 345 346 /* tickle device maybe there is some cleanup */ 347 netpoll_poll_dev(np->dev); 348 349 udelay(USEC_PER_POLL); 350 } 351 352 WARN_ONCE(!irqs_disabled(), 353 "netpoll_send_skb_on_dev(): %s enabled interrupts in poll (%pS)\n", 354 dev->name, dev->netdev_ops->ndo_start_xmit); 355 356 } 357 358 if (!dev_xmit_complete(status)) { 359 skb_queue_tail(&npinfo->txq, skb); 360 schedule_delayed_work(&npinfo->tx_work,0); 361 } 362 return NETDEV_TX_OK; 363 } 364 365 netdev_tx_t netpoll_send_skb(struct netpoll *np, struct sk_buff *skb) 366 { 367 unsigned long flags; 368 netdev_tx_t ret; 369 370 if (unlikely(!np)) { 371 dev_kfree_skb_irq(skb); 372 ret = NET_XMIT_DROP; 373 } else { 374 local_irq_save(flags); 375 ret = __netpoll_send_skb(np, skb); 376 local_irq_restore(flags); 377 } 378 return ret; 379 } 380 EXPORT_SYMBOL(netpoll_send_skb); 381 382 void netpoll_send_udp(struct netpoll *np, const char *msg, int len) 383 { 384 int total_len, ip_len, udp_len; 385 struct sk_buff *skb; 386 struct udphdr *udph; 387 struct iphdr *iph; 388 struct ethhdr *eth; 389 static atomic_t ip_ident; 390 struct ipv6hdr *ip6h; 391 392 WARN_ON_ONCE(!irqs_disabled()); 393 394 udp_len = len + sizeof(*udph); 395 if (np->ipv6) 396 ip_len = udp_len + sizeof(*ip6h); 397 else 398 ip_len = udp_len + sizeof(*iph); 399 400 total_len = ip_len + LL_RESERVED_SPACE(np->dev); 401 402 skb = find_skb(np, total_len + np->dev->needed_tailroom, 403 total_len - len); 404 if (!skb) 405 return; 406 407 skb_copy_to_linear_data(skb, msg, len); 408 skb_put(skb, len); 409 410 skb_push(skb, sizeof(*udph)); 411 skb_reset_transport_header(skb); 412 udph = udp_hdr(skb); 413 udph->source = htons(np->local_port); 414 udph->dest = htons(np->remote_port); 415 udph->len = htons(udp_len); 416 417 if (np->ipv6) { 418 udph->check = 0; 419 udph->check = csum_ipv6_magic(&np->local_ip.in6, 420 &np->remote_ip.in6, 421 udp_len, IPPROTO_UDP, 422 csum_partial(udph, udp_len, 0)); 423 if (udph->check == 0) 424 udph->check = CSUM_MANGLED_0; 425 426 skb_push(skb, sizeof(*ip6h)); 427 skb_reset_network_header(skb); 428 ip6h = ipv6_hdr(skb); 429 430 /* ip6h->version = 6; ip6h->priority = 0; */ 431 put_unaligned(0x60, (unsigned char *)ip6h); 432 ip6h->flow_lbl[0] = 0; 433 ip6h->flow_lbl[1] = 0; 434 ip6h->flow_lbl[2] = 0; 435 436 ip6h->payload_len = htons(sizeof(struct udphdr) + len); 437 ip6h->nexthdr = IPPROTO_UDP; 438 ip6h->hop_limit = 32; 439 ip6h->saddr = np->local_ip.in6; 440 ip6h->daddr = np->remote_ip.in6; 441 442 eth = skb_push(skb, ETH_HLEN); 443 skb_reset_mac_header(skb); 444 skb->protocol = eth->h_proto = htons(ETH_P_IPV6); 445 } else { 446 udph->check = 0; 447 udph->check = csum_tcpudp_magic(np->local_ip.ip, 448 np->remote_ip.ip, 449 udp_len, IPPROTO_UDP, 450 csum_partial(udph, udp_len, 0)); 451 if (udph->check == 0) 452 udph->check = CSUM_MANGLED_0; 453 454 skb_push(skb, sizeof(*iph)); 455 skb_reset_network_header(skb); 456 iph = ip_hdr(skb); 457 458 /* iph->version = 4; iph->ihl = 5; */ 459 put_unaligned(0x45, (unsigned char *)iph); 460 iph->tos = 0; 461 put_unaligned(htons(ip_len), &(iph->tot_len)); 462 iph->id = htons(atomic_inc_return(&ip_ident)); 463 iph->frag_off = 0; 464 iph->ttl = 64; 465 iph->protocol = IPPROTO_UDP; 466 iph->check = 0; 467 put_unaligned(np->local_ip.ip, &(iph->saddr)); 468 put_unaligned(np->remote_ip.ip, &(iph->daddr)); 469 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); 470 471 eth = skb_push(skb, ETH_HLEN); 472 skb_reset_mac_header(skb); 473 skb->protocol = eth->h_proto = htons(ETH_P_IP); 474 } 475 476 ether_addr_copy(eth->h_source, np->dev->dev_addr); 477 ether_addr_copy(eth->h_dest, np->remote_mac); 478 479 skb->dev = np->dev; 480 481 netpoll_send_skb(np, skb); 482 } 483 EXPORT_SYMBOL(netpoll_send_udp); 484 485 void netpoll_print_options(struct netpoll *np) 486 { 487 np_info(np, "local port %d\n", np->local_port); 488 if (np->ipv6) 489 np_info(np, "local IPv6 address %pI6c\n", &np->local_ip.in6); 490 else 491 np_info(np, "local IPv4 address %pI4\n", &np->local_ip.ip); 492 np_info(np, "interface '%s'\n", np->dev_name); 493 np_info(np, "remote port %d\n", np->remote_port); 494 if (np->ipv6) 495 np_info(np, "remote IPv6 address %pI6c\n", &np->remote_ip.in6); 496 else 497 np_info(np, "remote IPv4 address %pI4\n", &np->remote_ip.ip); 498 np_info(np, "remote ethernet address %pM\n", np->remote_mac); 499 } 500 EXPORT_SYMBOL(netpoll_print_options); 501 502 static int netpoll_parse_ip_addr(const char *str, union inet_addr *addr) 503 { 504 const char *end; 505 506 if (!strchr(str, ':') && 507 in4_pton(str, -1, (void *)addr, -1, &end) > 0) { 508 if (!*end) 509 return 0; 510 } 511 if (in6_pton(str, -1, addr->in6.s6_addr, -1, &end) > 0) { 512 #if IS_ENABLED(CONFIG_IPV6) 513 if (!*end) 514 return 1; 515 #else 516 return -1; 517 #endif 518 } 519 return -1; 520 } 521 522 int netpoll_parse_options(struct netpoll *np, char *opt) 523 { 524 char *cur=opt, *delim; 525 int ipv6; 526 bool ipversion_set = false; 527 528 if (*cur != '@') { 529 if ((delim = strchr(cur, '@')) == NULL) 530 goto parse_failed; 531 *delim = 0; 532 if (kstrtou16(cur, 10, &np->local_port)) 533 goto parse_failed; 534 cur = delim; 535 } 536 cur++; 537 538 if (*cur != '/') { 539 ipversion_set = true; 540 if ((delim = strchr(cur, '/')) == NULL) 541 goto parse_failed; 542 *delim = 0; 543 ipv6 = netpoll_parse_ip_addr(cur, &np->local_ip); 544 if (ipv6 < 0) 545 goto parse_failed; 546 else 547 np->ipv6 = (bool)ipv6; 548 cur = delim; 549 } 550 cur++; 551 552 if (*cur != ',') { 553 /* parse out dev name */ 554 if ((delim = strchr(cur, ',')) == NULL) 555 goto parse_failed; 556 *delim = 0; 557 strlcpy(np->dev_name, cur, sizeof(np->dev_name)); 558 cur = delim; 559 } 560 cur++; 561 562 if (*cur != '@') { 563 /* dst port */ 564 if ((delim = strchr(cur, '@')) == NULL) 565 goto parse_failed; 566 *delim = 0; 567 if (*cur == ' ' || *cur == '\t') 568 np_info(np, "warning: whitespace is not allowed\n"); 569 if (kstrtou16(cur, 10, &np->remote_port)) 570 goto parse_failed; 571 cur = delim; 572 } 573 cur++; 574 575 /* dst ip */ 576 if ((delim = strchr(cur, '/')) == NULL) 577 goto parse_failed; 578 *delim = 0; 579 ipv6 = netpoll_parse_ip_addr(cur, &np->remote_ip); 580 if (ipv6 < 0) 581 goto parse_failed; 582 else if (ipversion_set && np->ipv6 != (bool)ipv6) 583 goto parse_failed; 584 else 585 np->ipv6 = (bool)ipv6; 586 cur = delim + 1; 587 588 if (*cur != 0) { 589 /* MAC address */ 590 if (!mac_pton(cur, np->remote_mac)) 591 goto parse_failed; 592 } 593 594 netpoll_print_options(np); 595 596 return 0; 597 598 parse_failed: 599 np_info(np, "couldn't parse config at '%s'!\n", cur); 600 return -1; 601 } 602 EXPORT_SYMBOL(netpoll_parse_options); 603 604 int __netpoll_setup(struct netpoll *np, struct net_device *ndev) 605 { 606 struct netpoll_info *npinfo; 607 const struct net_device_ops *ops; 608 int err; 609 610 np->dev = ndev; 611 strlcpy(np->dev_name, ndev->name, IFNAMSIZ); 612 613 if (ndev->priv_flags & IFF_DISABLE_NETPOLL) { 614 np_err(np, "%s doesn't support polling, aborting\n", 615 np->dev_name); 616 err = -ENOTSUPP; 617 goto out; 618 } 619 620 if (!ndev->npinfo) { 621 npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL); 622 if (!npinfo) { 623 err = -ENOMEM; 624 goto out; 625 } 626 627 sema_init(&npinfo->dev_lock, 1); 628 skb_queue_head_init(&npinfo->txq); 629 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process); 630 631 refcount_set(&npinfo->refcnt, 1); 632 633 ops = np->dev->netdev_ops; 634 if (ops->ndo_netpoll_setup) { 635 err = ops->ndo_netpoll_setup(ndev, npinfo); 636 if (err) 637 goto free_npinfo; 638 } 639 } else { 640 npinfo = rtnl_dereference(ndev->npinfo); 641 refcount_inc(&npinfo->refcnt); 642 } 643 644 npinfo->netpoll = np; 645 646 /* last thing to do is link it to the net device structure */ 647 rcu_assign_pointer(ndev->npinfo, npinfo); 648 649 return 0; 650 651 free_npinfo: 652 kfree(npinfo); 653 out: 654 return err; 655 } 656 EXPORT_SYMBOL_GPL(__netpoll_setup); 657 658 int netpoll_setup(struct netpoll *np) 659 { 660 struct net_device *ndev = NULL; 661 struct in_device *in_dev; 662 int err; 663 664 rtnl_lock(); 665 if (np->dev_name[0]) { 666 struct net *net = current->nsproxy->net_ns; 667 ndev = __dev_get_by_name(net, np->dev_name); 668 } 669 if (!ndev) { 670 np_err(np, "%s doesn't exist, aborting\n", np->dev_name); 671 err = -ENODEV; 672 goto unlock; 673 } 674 dev_hold(ndev); 675 676 if (netdev_master_upper_dev_get(ndev)) { 677 np_err(np, "%s is a slave device, aborting\n", np->dev_name); 678 err = -EBUSY; 679 goto put; 680 } 681 682 if (!netif_running(ndev)) { 683 unsigned long atmost, atleast; 684 685 np_info(np, "device %s not up yet, forcing it\n", np->dev_name); 686 687 err = dev_open(ndev, NULL); 688 689 if (err) { 690 np_err(np, "failed to open %s\n", ndev->name); 691 goto put; 692 } 693 694 rtnl_unlock(); 695 atleast = jiffies + HZ/10; 696 atmost = jiffies + carrier_timeout * HZ; 697 while (!netif_carrier_ok(ndev)) { 698 if (time_after(jiffies, atmost)) { 699 np_notice(np, "timeout waiting for carrier\n"); 700 break; 701 } 702 msleep(1); 703 } 704 705 /* If carrier appears to come up instantly, we don't 706 * trust it and pause so that we don't pump all our 707 * queued console messages into the bitbucket. 708 */ 709 710 if (time_before(jiffies, atleast)) { 711 np_notice(np, "carrier detect appears untrustworthy, waiting 4 seconds\n"); 712 msleep(4000); 713 } 714 rtnl_lock(); 715 } 716 717 if (!np->local_ip.ip) { 718 if (!np->ipv6) { 719 const struct in_ifaddr *ifa; 720 721 in_dev = __in_dev_get_rtnl(ndev); 722 if (!in_dev) 723 goto put_noaddr; 724 725 ifa = rtnl_dereference(in_dev->ifa_list); 726 if (!ifa) { 727 put_noaddr: 728 np_err(np, "no IP address for %s, aborting\n", 729 np->dev_name); 730 err = -EDESTADDRREQ; 731 goto put; 732 } 733 734 np->local_ip.ip = ifa->ifa_local; 735 np_info(np, "local IP %pI4\n", &np->local_ip.ip); 736 } else { 737 #if IS_ENABLED(CONFIG_IPV6) 738 struct inet6_dev *idev; 739 740 err = -EDESTADDRREQ; 741 idev = __in6_dev_get(ndev); 742 if (idev) { 743 struct inet6_ifaddr *ifp; 744 745 read_lock_bh(&idev->lock); 746 list_for_each_entry(ifp, &idev->addr_list, if_list) { 747 if (!!(ipv6_addr_type(&ifp->addr) & IPV6_ADDR_LINKLOCAL) != 748 !!(ipv6_addr_type(&np->remote_ip.in6) & IPV6_ADDR_LINKLOCAL)) 749 continue; 750 np->local_ip.in6 = ifp->addr; 751 err = 0; 752 break; 753 } 754 read_unlock_bh(&idev->lock); 755 } 756 if (err) { 757 np_err(np, "no IPv6 address for %s, aborting\n", 758 np->dev_name); 759 goto put; 760 } else 761 np_info(np, "local IPv6 %pI6c\n", &np->local_ip.in6); 762 #else 763 np_err(np, "IPv6 is not supported %s, aborting\n", 764 np->dev_name); 765 err = -EINVAL; 766 goto put; 767 #endif 768 } 769 } 770 771 /* fill up the skb queue */ 772 refill_skbs(); 773 774 err = __netpoll_setup(np, ndev); 775 if (err) 776 goto put; 777 778 rtnl_unlock(); 779 return 0; 780 781 put: 782 dev_put(ndev); 783 unlock: 784 rtnl_unlock(); 785 return err; 786 } 787 EXPORT_SYMBOL(netpoll_setup); 788 789 static int __init netpoll_init(void) 790 { 791 skb_queue_head_init(&skb_pool); 792 return 0; 793 } 794 core_initcall(netpoll_init); 795 796 static void rcu_cleanup_netpoll_info(struct rcu_head *rcu_head) 797 { 798 struct netpoll_info *npinfo = 799 container_of(rcu_head, struct netpoll_info, rcu); 800 801 skb_queue_purge(&npinfo->txq); 802 803 /* we can't call cancel_delayed_work_sync here, as we are in softirq */ 804 cancel_delayed_work(&npinfo->tx_work); 805 806 /* clean after last, unfinished work */ 807 __skb_queue_purge(&npinfo->txq); 808 /* now cancel it again */ 809 cancel_delayed_work(&npinfo->tx_work); 810 kfree(npinfo); 811 } 812 813 void __netpoll_cleanup(struct netpoll *np) 814 { 815 struct netpoll_info *npinfo; 816 817 npinfo = rtnl_dereference(np->dev->npinfo); 818 if (!npinfo) 819 return; 820 821 synchronize_srcu(&netpoll_srcu); 822 823 if (refcount_dec_and_test(&npinfo->refcnt)) { 824 const struct net_device_ops *ops; 825 826 ops = np->dev->netdev_ops; 827 if (ops->ndo_netpoll_cleanup) 828 ops->ndo_netpoll_cleanup(np->dev); 829 830 RCU_INIT_POINTER(np->dev->npinfo, NULL); 831 call_rcu(&npinfo->rcu, rcu_cleanup_netpoll_info); 832 } else 833 RCU_INIT_POINTER(np->dev->npinfo, NULL); 834 } 835 EXPORT_SYMBOL_GPL(__netpoll_cleanup); 836 837 void __netpoll_free(struct netpoll *np) 838 { 839 ASSERT_RTNL(); 840 841 /* Wait for transmitting packets to finish before freeing. */ 842 synchronize_rcu(); 843 __netpoll_cleanup(np); 844 kfree(np); 845 } 846 EXPORT_SYMBOL_GPL(__netpoll_free); 847 848 void netpoll_cleanup(struct netpoll *np) 849 { 850 rtnl_lock(); 851 if (!np->dev) 852 goto out; 853 __netpoll_cleanup(np); 854 dev_put(np->dev); 855 np->dev = NULL; 856 out: 857 rtnl_unlock(); 858 } 859 EXPORT_SYMBOL(netpoll_cleanup); 860