1262266Sbapt// SPDX-License-Identifier: GPL-2.0-only 2262266Sbapt/* 3289123Sbapt * Common framework for low-level network console, dump, and debugger code 4289123Sbapt * 5262266Sbapt * Sep 8 2003 Matt Mackall <mpm@selenic.com> 6289123Sbapt * 7262266Sbapt * based on the netconsole code from: 8262266Sbapt * 9262266Sbapt * Copyright (C) 2001 Ingo Molnar <mingo@redhat.com> 10262266Sbapt * Copyright (C) 2002 Red Hat, Inc. 11262266Sbapt */ 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 49static struct sk_buff_head skb_pool; 50 51DEFINE_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 61static void zap_completion_queue(void); 62 63static unsigned int carrier_timeout = 4; 64module_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 73static 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 96out: 97 return status; 98} 99 100static 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 140static int netif_local_xmit_active(struct net_device *dev) 141{ 142 int i; 143 144 for (i = 0; i < dev->num_tx_queues; i++) { 145 struct netdev_queue *txq = netdev_get_tx_queue(dev, i); 146 147 if (READ_ONCE(txq->xmit_lock_owner) == smp_processor_id()) 148 return 1; 149 } 150 151 return 0; 152} 153 154static void poll_one_napi(struct napi_struct *napi) 155{ 156 int work; 157 158 /* If we set this bit but see that it has already been set, 159 * that indicates that napi has been disabled and we need 160 * to abort this operation 161 */ 162 if (test_and_set_bit(NAPI_STATE_NPSVC, &napi->state)) 163 return; 164 165 /* We explicilty pass the polling call a budget of 0 to 166 * indicate that we are clearing the Tx path only. 167 */ 168 work = napi->poll(napi, 0); 169 WARN_ONCE(work, "%pS exceeded budget in poll\n", napi->poll); 170 trace_napi_poll(napi, work, 0); 171 172 clear_bit(NAPI_STATE_NPSVC, &napi->state); 173} 174 175static void poll_napi(struct net_device *dev) 176{ 177 struct napi_struct *napi; 178 int cpu = smp_processor_id(); 179 180 list_for_each_entry_rcu(napi, &dev->napi_list, dev_list) { 181 if (cmpxchg(&napi->poll_owner, -1, cpu) == -1) { 182 poll_one_napi(napi); 183 smp_store_release(&napi->poll_owner, -1); 184 } 185 } 186} 187 188void netpoll_poll_dev(struct net_device *dev) 189{ 190 struct netpoll_info *ni = rcu_dereference_bh(dev->npinfo); 191 const struct net_device_ops *ops; 192 193 /* Don't do any rx activity if the dev_lock mutex is held 194 * the dev_open/close paths use this to block netpoll activity 195 * while changing device state 196 */ 197 if (!ni || down_trylock(&ni->dev_lock)) 198 return; 199 200 /* Some drivers will take the same locks in poll and xmit, 201 * we can't poll if local CPU is already in xmit. 202 */ 203 if (!netif_running(dev) || netif_local_xmit_active(dev)) { 204 up(&ni->dev_lock); 205 return; 206 } 207 208 ops = dev->netdev_ops; 209 if (ops->ndo_poll_controller) 210 ops->ndo_poll_controller(dev); 211 212 poll_napi(dev); 213 214 up(&ni->dev_lock); 215 216 zap_completion_queue(); 217} 218EXPORT_SYMBOL(netpoll_poll_dev); 219 220void netpoll_poll_disable(struct net_device *dev) 221{ 222 struct netpoll_info *ni; 223 int idx; 224 might_sleep(); 225 idx = srcu_read_lock(&netpoll_srcu); 226 ni = srcu_dereference(dev->npinfo, &netpoll_srcu); 227 if (ni) 228 down(&ni->dev_lock); 229 srcu_read_unlock(&netpoll_srcu, idx); 230} 231EXPORT_SYMBOL(netpoll_poll_disable); 232 233void netpoll_poll_enable(struct net_device *dev) 234{ 235 struct netpoll_info *ni; 236 rcu_read_lock(); 237 ni = rcu_dereference(dev->npinfo); 238 if (ni) 239 up(&ni->dev_lock); 240 rcu_read_unlock(); 241} 242EXPORT_SYMBOL(netpoll_poll_enable); 243 244static void refill_skbs(void) 245{ 246 struct sk_buff *skb; 247 unsigned long flags; 248 249 spin_lock_irqsave(&skb_pool.lock, flags); 250 while (skb_pool.qlen < MAX_SKBS) { 251 skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC); 252 if (!skb) 253 break; 254 255 __skb_queue_tail(&skb_pool, skb); 256 } 257 spin_unlock_irqrestore(&skb_pool.lock, flags); 258} 259 260static void zap_completion_queue(void) 261{ 262 unsigned long flags; 263 struct softnet_data *sd = &get_cpu_var(softnet_data); 264 265 if (sd->completion_queue) { 266 struct sk_buff *clist; 267 268 local_irq_save(flags); 269 clist = sd->completion_queue; 270 sd->completion_queue = NULL; 271 local_irq_restore(flags); 272 273 while (clist != NULL) { 274 struct sk_buff *skb = clist; 275 clist = clist->next; 276 if (!skb_irq_freeable(skb)) { 277 refcount_set(&skb->users, 1); 278 dev_kfree_skb_any(skb); /* put this one back */ 279 } else { 280 __kfree_skb(skb); 281 } 282 } 283 } 284 285 put_cpu_var(softnet_data); 286} 287 288static struct sk_buff *find_skb(struct netpoll *np, int len, int reserve) 289{ 290 int count = 0; 291 struct sk_buff *skb; 292 293 zap_completion_queue(); 294 refill_skbs(); 295repeat: 296 297 skb = alloc_skb(len, GFP_ATOMIC); 298 if (!skb) 299 skb = skb_dequeue(&skb_pool); 300 301 if (!skb) { 302 if (++count < 10) { 303 netpoll_poll_dev(np->dev); 304 goto repeat; 305 } 306 return NULL; 307 } 308 309 refcount_set(&skb->users, 1); 310 skb_reserve(skb, reserve); 311 return skb; 312} 313 314static int netpoll_owner_active(struct net_device *dev) 315{ 316 struct napi_struct *napi; 317 318 list_for_each_entry_rcu(napi, &dev->napi_list, dev_list) { 319 if (napi->poll_owner == smp_processor_id()) 320 return 1; 321 } 322 return 0; 323} 324 325/* call with IRQ disabled */ 326static netdev_tx_t __netpoll_send_skb(struct netpoll *np, struct sk_buff *skb) 327{ 328 netdev_tx_t status = NETDEV_TX_BUSY; 329 struct net_device *dev; 330 unsigned long tries; 331 /* It is up to the caller to keep npinfo alive. */ 332 struct netpoll_info *npinfo; 333 334 lockdep_assert_irqs_disabled(); 335 336 dev = np->dev; 337 npinfo = rcu_dereference_bh(dev->npinfo); 338 339 if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) { 340 dev_kfree_skb_irq(skb); 341 return NET_XMIT_DROP; 342 } 343 344 /* don't get messages out of order, and no recursion */ 345 if (skb_queue_len(&npinfo->txq) == 0 && !netpoll_owner_active(dev)) { 346 struct netdev_queue *txq; 347 348 txq = netdev_core_pick_tx(dev, skb, NULL); 349 350 /* try until next clock tick */ 351 for (tries = jiffies_to_usecs(1)/USEC_PER_POLL; 352 tries > 0; --tries) { 353 if (HARD_TX_TRYLOCK(dev, txq)) { 354 if (!netif_xmit_stopped(txq)) 355 status = netpoll_start_xmit(skb, dev, txq); 356 357 HARD_TX_UNLOCK(dev, txq); 358 359 if (dev_xmit_complete(status)) 360 break; 361 362 } 363 364 /* tickle device maybe there is some cleanup */ 365 netpoll_poll_dev(np->dev); 366 367 udelay(USEC_PER_POLL); 368 } 369 370 WARN_ONCE(!irqs_disabled(), 371 "netpoll_send_skb_on_dev(): %s enabled interrupts in poll (%pS)\n", 372 dev->name, dev->netdev_ops->ndo_start_xmit); 373 374 } 375 376 if (!dev_xmit_complete(status)) { 377 skb_queue_tail(&npinfo->txq, skb); 378 schedule_delayed_work(&npinfo->tx_work,0); 379 } 380 return NETDEV_TX_OK; 381} 382 383netdev_tx_t netpoll_send_skb(struct netpoll *np, struct sk_buff *skb) 384{ 385 unsigned long flags; 386 netdev_tx_t ret; 387 388 if (unlikely(!np)) { 389 dev_kfree_skb_irq(skb); 390 ret = NET_XMIT_DROP; 391 } else { 392 local_irq_save(flags); 393 ret = __netpoll_send_skb(np, skb); 394 local_irq_restore(flags); 395 } 396 return ret; 397} 398EXPORT_SYMBOL(netpoll_send_skb); 399 400void netpoll_send_udp(struct netpoll *np, const char *msg, int len) 401{ 402 int total_len, ip_len, udp_len; 403 struct sk_buff *skb; 404 struct udphdr *udph; 405 struct iphdr *iph; 406 struct ethhdr *eth; 407 static atomic_t ip_ident; 408 struct ipv6hdr *ip6h; 409 410 if (!IS_ENABLED(CONFIG_PREEMPT_RT)) 411 WARN_ON_ONCE(!irqs_disabled()); 412 413 udp_len = len + sizeof(*udph); 414 if (np->ipv6) 415 ip_len = udp_len + sizeof(*ip6h); 416 else 417 ip_len = udp_len + sizeof(*iph); 418 419 total_len = ip_len + LL_RESERVED_SPACE(np->dev); 420 421 skb = find_skb(np, total_len + np->dev->needed_tailroom, 422 total_len - len); 423 if (!skb) 424 return; 425 426 skb_copy_to_linear_data(skb, msg, len); 427 skb_put(skb, len); 428 429 skb_push(skb, sizeof(*udph)); 430 skb_reset_transport_header(skb); 431 udph = udp_hdr(skb); 432 udph->source = htons(np->local_port); 433 udph->dest = htons(np->remote_port); 434 udph->len = htons(udp_len); 435 436 if (np->ipv6) { 437 udph->check = 0; 438 udph->check = csum_ipv6_magic(&np->local_ip.in6, 439 &np->remote_ip.in6, 440 udp_len, IPPROTO_UDP, 441 csum_partial(udph, udp_len, 0)); 442 if (udph->check == 0) 443 udph->check = CSUM_MANGLED_0; 444 445 skb_push(skb, sizeof(*ip6h)); 446 skb_reset_network_header(skb); 447 ip6h = ipv6_hdr(skb); 448 449 /* ip6h->version = 6; ip6h->priority = 0; */ 450 *(unsigned char *)ip6h = 0x60; 451 ip6h->flow_lbl[0] = 0; 452 ip6h->flow_lbl[1] = 0; 453 ip6h->flow_lbl[2] = 0; 454 455 ip6h->payload_len = htons(sizeof(struct udphdr) + len); 456 ip6h->nexthdr = IPPROTO_UDP; 457 ip6h->hop_limit = 32; 458 ip6h->saddr = np->local_ip.in6; 459 ip6h->daddr = np->remote_ip.in6; 460 461 eth = skb_push(skb, ETH_HLEN); 462 skb_reset_mac_header(skb); 463 skb->protocol = eth->h_proto = htons(ETH_P_IPV6); 464 } else { 465 udph->check = 0; 466 udph->check = csum_tcpudp_magic(np->local_ip.ip, 467 np->remote_ip.ip, 468 udp_len, IPPROTO_UDP, 469 csum_partial(udph, udp_len, 0)); 470 if (udph->check == 0) 471 udph->check = CSUM_MANGLED_0; 472 473 skb_push(skb, sizeof(*iph)); 474 skb_reset_network_header(skb); 475 iph = ip_hdr(skb); 476 477 /* iph->version = 4; iph->ihl = 5; */ 478 *(unsigned char *)iph = 0x45; 479 iph->tos = 0; 480 put_unaligned(htons(ip_len), &(iph->tot_len)); 481 iph->id = htons(atomic_inc_return(&ip_ident)); 482 iph->frag_off = 0; 483 iph->ttl = 64; 484 iph->protocol = IPPROTO_UDP; 485 iph->check = 0; 486 put_unaligned(np->local_ip.ip, &(iph->saddr)); 487 put_unaligned(np->remote_ip.ip, &(iph->daddr)); 488 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); 489 490 eth = skb_push(skb, ETH_HLEN); 491 skb_reset_mac_header(skb); 492 skb->protocol = eth->h_proto = htons(ETH_P_IP); 493 } 494 495 ether_addr_copy(eth->h_source, np->dev->dev_addr); 496 ether_addr_copy(eth->h_dest, np->remote_mac); 497 498 skb->dev = np->dev; 499 500 netpoll_send_skb(np, skb); 501} 502EXPORT_SYMBOL(netpoll_send_udp); 503 504void netpoll_print_options(struct netpoll *np) 505{ 506 np_info(np, "local port %d\n", np->local_port); 507 if (np->ipv6) 508 np_info(np, "local IPv6 address %pI6c\n", &np->local_ip.in6); 509 else 510 np_info(np, "local IPv4 address %pI4\n", &np->local_ip.ip); 511 np_info(np, "interface '%s'\n", np->dev_name); 512 np_info(np, "remote port %d\n", np->remote_port); 513 if (np->ipv6) 514 np_info(np, "remote IPv6 address %pI6c\n", &np->remote_ip.in6); 515 else 516 np_info(np, "remote IPv4 address %pI4\n", &np->remote_ip.ip); 517 np_info(np, "remote ethernet address %pM\n", np->remote_mac); 518} 519EXPORT_SYMBOL(netpoll_print_options); 520 521static int netpoll_parse_ip_addr(const char *str, union inet_addr *addr) 522{ 523 const char *end; 524 525 if (!strchr(str, ':') && 526 in4_pton(str, -1, (void *)addr, -1, &end) > 0) { 527 if (!*end) 528 return 0; 529 } 530 if (in6_pton(str, -1, addr->in6.s6_addr, -1, &end) > 0) { 531#if IS_ENABLED(CONFIG_IPV6) 532 if (!*end) 533 return 1; 534#else 535 return -1; 536#endif 537 } 538 return -1; 539} 540 541int netpoll_parse_options(struct netpoll *np, char *opt) 542{ 543 char *cur=opt, *delim; 544 int ipv6; 545 bool ipversion_set = false; 546 547 if (*cur != '@') { 548 if ((delim = strchr(cur, '@')) == NULL) 549 goto parse_failed; 550 *delim = 0; 551 if (kstrtou16(cur, 10, &np->local_port)) 552 goto parse_failed; 553 cur = delim; 554 } 555 cur++; 556 557 if (*cur != '/') { 558 ipversion_set = true; 559 if ((delim = strchr(cur, '/')) == NULL) 560 goto parse_failed; 561 *delim = 0; 562 ipv6 = netpoll_parse_ip_addr(cur, &np->local_ip); 563 if (ipv6 < 0) 564 goto parse_failed; 565 else 566 np->ipv6 = (bool)ipv6; 567 cur = delim; 568 } 569 cur++; 570 571 if (*cur != ',') { 572 /* parse out dev name */ 573 if ((delim = strchr(cur, ',')) == NULL) 574 goto parse_failed; 575 *delim = 0; 576 strscpy(np->dev_name, cur, sizeof(np->dev_name)); 577 cur = delim; 578 } 579 cur++; 580 581 if (*cur != '@') { 582 /* dst port */ 583 if ((delim = strchr(cur, '@')) == NULL) 584 goto parse_failed; 585 *delim = 0; 586 if (*cur == ' ' || *cur == '\t') 587 np_info(np, "warning: whitespace is not allowed\n"); 588 if (kstrtou16(cur, 10, &np->remote_port)) 589 goto parse_failed; 590 cur = delim; 591 } 592 cur++; 593 594 /* dst ip */ 595 if ((delim = strchr(cur, '/')) == NULL) 596 goto parse_failed; 597 *delim = 0; 598 ipv6 = netpoll_parse_ip_addr(cur, &np->remote_ip); 599 if (ipv6 < 0) 600 goto parse_failed; 601 else if (ipversion_set && np->ipv6 != (bool)ipv6) 602 goto parse_failed; 603 else 604 np->ipv6 = (bool)ipv6; 605 cur = delim + 1; 606 607 if (*cur != 0) { 608 /* MAC address */ 609 if (!mac_pton(cur, np->remote_mac)) 610 goto parse_failed; 611 } 612 613 netpoll_print_options(np); 614 615 return 0; 616 617 parse_failed: 618 np_info(np, "couldn't parse config at '%s'!\n", cur); 619 return -1; 620} 621EXPORT_SYMBOL(netpoll_parse_options); 622 623int __netpoll_setup(struct netpoll *np, struct net_device *ndev) 624{ 625 struct netpoll_info *npinfo; 626 const struct net_device_ops *ops; 627 int err; 628 629 np->dev = ndev; 630 strscpy(np->dev_name, ndev->name, IFNAMSIZ); 631 632 if (ndev->priv_flags & IFF_DISABLE_NETPOLL) { 633 np_err(np, "%s doesn't support polling, aborting\n", 634 np->dev_name); 635 err = -ENOTSUPP; 636 goto out; 637 } 638 639 if (!ndev->npinfo) { 640 npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL); 641 if (!npinfo) { 642 err = -ENOMEM; 643 goto out; 644 } 645 646 sema_init(&npinfo->dev_lock, 1); 647 skb_queue_head_init(&npinfo->txq); 648 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process); 649 650 refcount_set(&npinfo->refcnt, 1); 651 652 ops = np->dev->netdev_ops; 653 if (ops->ndo_netpoll_setup) { 654 err = ops->ndo_netpoll_setup(ndev, npinfo); 655 if (err) 656 goto free_npinfo; 657 } 658 } else { 659 npinfo = rtnl_dereference(ndev->npinfo); 660 refcount_inc(&npinfo->refcnt); 661 } 662 663 npinfo->netpoll = np; 664 665 /* last thing to do is link it to the net device structure */ 666 rcu_assign_pointer(ndev->npinfo, npinfo); 667 668 return 0; 669 670free_npinfo: 671 kfree(npinfo); 672out: 673 return err; 674} 675EXPORT_SYMBOL_GPL(__netpoll_setup); 676 677int netpoll_setup(struct netpoll *np) 678{ 679 struct net_device *ndev = NULL; 680 struct in_device *in_dev; 681 int err; 682 683 rtnl_lock(); 684 if (np->dev_name[0]) { 685 struct net *net = current->nsproxy->net_ns; 686 ndev = __dev_get_by_name(net, np->dev_name); 687 } 688 if (!ndev) { 689 np_err(np, "%s doesn't exist, aborting\n", np->dev_name); 690 err = -ENODEV; 691 goto unlock; 692 } 693 netdev_hold(ndev, &np->dev_tracker, GFP_KERNEL); 694 695 if (netdev_master_upper_dev_get(ndev)) { 696 np_err(np, "%s is a slave device, aborting\n", np->dev_name); 697 err = -EBUSY; 698 goto put; 699 } 700 701 if (!netif_running(ndev)) { 702 unsigned long atmost; 703 704 np_info(np, "device %s not up yet, forcing it\n", np->dev_name); 705 706 err = dev_open(ndev, NULL); 707 708 if (err) { 709 np_err(np, "failed to open %s\n", ndev->name); 710 goto put; 711 } 712 713 rtnl_unlock(); 714 atmost = jiffies + carrier_timeout * HZ; 715 while (!netif_carrier_ok(ndev)) { 716 if (time_after(jiffies, atmost)) { 717 np_notice(np, "timeout waiting for carrier\n"); 718 break; 719 } 720 msleep(1); 721 } 722 723 rtnl_lock(); 724 } 725 726 if (!np->local_ip.ip) { 727 if (!np->ipv6) { 728 const struct in_ifaddr *ifa; 729 730 in_dev = __in_dev_get_rtnl(ndev); 731 if (!in_dev) 732 goto put_noaddr; 733 734 ifa = rtnl_dereference(in_dev->ifa_list); 735 if (!ifa) { 736put_noaddr: 737 np_err(np, "no IP address for %s, aborting\n", 738 np->dev_name); 739 err = -EDESTADDRREQ; 740 goto put; 741 } 742 743 np->local_ip.ip = ifa->ifa_local; 744 np_info(np, "local IP %pI4\n", &np->local_ip.ip); 745 } else { 746#if IS_ENABLED(CONFIG_IPV6) 747 struct inet6_dev *idev; 748 749 err = -EDESTADDRREQ; 750 idev = __in6_dev_get(ndev); 751 if (idev) { 752 struct inet6_ifaddr *ifp; 753 754 read_lock_bh(&idev->lock); 755 list_for_each_entry(ifp, &idev->addr_list, if_list) { 756 if (!!(ipv6_addr_type(&ifp->addr) & IPV6_ADDR_LINKLOCAL) != 757 !!(ipv6_addr_type(&np->remote_ip.in6) & IPV6_ADDR_LINKLOCAL)) 758 continue; 759 np->local_ip.in6 = ifp->addr; 760 err = 0; 761 break; 762 } 763 read_unlock_bh(&idev->lock); 764 } 765 if (err) { 766 np_err(np, "no IPv6 address for %s, aborting\n", 767 np->dev_name); 768 goto put; 769 } else 770 np_info(np, "local IPv6 %pI6c\n", &np->local_ip.in6); 771#else 772 np_err(np, "IPv6 is not supported %s, aborting\n", 773 np->dev_name); 774 err = -EINVAL; 775 goto put; 776#endif 777 } 778 } 779 780 /* fill up the skb queue */ 781 refill_skbs(); 782 783 err = __netpoll_setup(np, ndev); 784 if (err) 785 goto put; 786 rtnl_unlock(); 787 return 0; 788 789put: 790 netdev_put(ndev, &np->dev_tracker); 791unlock: 792 rtnl_unlock(); 793 return err; 794} 795EXPORT_SYMBOL(netpoll_setup); 796 797static int __init netpoll_init(void) 798{ 799 skb_queue_head_init(&skb_pool); 800 return 0; 801} 802core_initcall(netpoll_init); 803 804static void rcu_cleanup_netpoll_info(struct rcu_head *rcu_head) 805{ 806 struct netpoll_info *npinfo = 807 container_of(rcu_head, struct netpoll_info, rcu); 808 809 skb_queue_purge(&npinfo->txq); 810 811 /* we can't call cancel_delayed_work_sync here, as we are in softirq */ 812 cancel_delayed_work(&npinfo->tx_work); 813 814 /* clean after last, unfinished work */ 815 __skb_queue_purge(&npinfo->txq); 816 /* now cancel it again */ 817 cancel_delayed_work(&npinfo->tx_work); 818 kfree(npinfo); 819} 820 821void __netpoll_cleanup(struct netpoll *np) 822{ 823 struct netpoll_info *npinfo; 824 825 npinfo = rtnl_dereference(np->dev->npinfo); 826 if (!npinfo) 827 return; 828 829 synchronize_srcu(&netpoll_srcu); 830 831 if (refcount_dec_and_test(&npinfo->refcnt)) { 832 const struct net_device_ops *ops; 833 834 ops = np->dev->netdev_ops; 835 if (ops->ndo_netpoll_cleanup) 836 ops->ndo_netpoll_cleanup(np->dev); 837 838 RCU_INIT_POINTER(np->dev->npinfo, NULL); 839 call_rcu(&npinfo->rcu, rcu_cleanup_netpoll_info); 840 } else 841 RCU_INIT_POINTER(np->dev->npinfo, NULL); 842} 843EXPORT_SYMBOL_GPL(__netpoll_cleanup); 844 845void __netpoll_free(struct netpoll *np) 846{ 847 ASSERT_RTNL(); 848 849 /* Wait for transmitting packets to finish before freeing. */ 850 synchronize_rcu(); 851 __netpoll_cleanup(np); 852 kfree(np); 853} 854EXPORT_SYMBOL_GPL(__netpoll_free); 855 856void netpoll_cleanup(struct netpoll *np) 857{ 858 rtnl_lock(); 859 if (!np->dev) 860 goto out; 861 __netpoll_cleanup(np); 862 netdev_put(np->dev, &np->dev_tracker); 863 np->dev = NULL; 864out: 865 rtnl_unlock(); 866} 867EXPORT_SYMBOL(netpoll_cleanup); 868