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 /* 139 * Check whether delayed processing was scheduled for our NIC. If so, 140 * we attempt to grab the poll lock and use ->poll() to pump the card. 141 * If this fails, either we've recursed in ->poll() or it's already 142 * running on another CPU. 143 * 144 * Note: we don't mask interrupts with this lock because we're using 145 * trylock here and interrupts are already disabled in the softirq 146 * case. Further, we test the poll_owner to avoid recursion on UP 147 * systems where the lock doesn't exist. 148 */ 149 static void poll_one_napi(struct napi_struct *napi) 150 { 151 int work = 0; 152 153 /* net_rx_action's ->poll() invocations and our's are 154 * synchronized by this test which is only made while 155 * holding the napi->poll_lock. 156 */ 157 if (!test_bit(NAPI_STATE_SCHED, &napi->state)) 158 return; 159 160 /* If we set this bit but see that it has already been set, 161 * that indicates that napi has been disabled and we need 162 * to abort this operation 163 */ 164 if (test_and_set_bit(NAPI_STATE_NPSVC, &napi->state)) 165 return; 166 167 /* We explicilty pass the polling call a budget of 0 to 168 * indicate that we are clearing the Tx path only. 169 */ 170 work = napi->poll(napi, 0); 171 WARN_ONCE(work, "%pF exceeded budget in poll\n", napi->poll); 172 trace_napi_poll(napi, work, 0); 173 174 clear_bit(NAPI_STATE_NPSVC, &napi->state); 175 } 176 177 static void poll_napi(struct net_device *dev) 178 { 179 struct napi_struct *napi; 180 int cpu = smp_processor_id(); 181 182 list_for_each_entry(napi, &dev->napi_list, dev_list) { 183 if (cmpxchg(&napi->poll_owner, -1, cpu) == -1) { 184 poll_one_napi(napi); 185 smp_store_release(&napi->poll_owner, -1); 186 } 187 } 188 } 189 190 static void netpoll_poll_dev(struct net_device *dev) 191 { 192 const struct net_device_ops *ops; 193 struct netpoll_info *ni = rcu_dereference_bh(dev->npinfo); 194 195 /* Don't do any rx activity if the dev_lock mutex is held 196 * the dev_open/close paths use this to block netpoll activity 197 * while changing device state 198 */ 199 if (down_trylock(&ni->dev_lock)) 200 return; 201 202 if (!netif_running(dev)) { 203 up(&ni->dev_lock); 204 return; 205 } 206 207 ops = dev->netdev_ops; 208 if (!ops->ndo_poll_controller) { 209 up(&ni->dev_lock); 210 return; 211 } 212 213 /* Process pending work on NIC */ 214 ops->ndo_poll_controller(dev); 215 216 poll_napi(dev); 217 218 up(&ni->dev_lock); 219 220 zap_completion_queue(); 221 } 222 223 void netpoll_poll_disable(struct net_device *dev) 224 { 225 struct netpoll_info *ni; 226 int idx; 227 might_sleep(); 228 idx = srcu_read_lock(&netpoll_srcu); 229 ni = srcu_dereference(dev->npinfo, &netpoll_srcu); 230 if (ni) 231 down(&ni->dev_lock); 232 srcu_read_unlock(&netpoll_srcu, idx); 233 } 234 EXPORT_SYMBOL(netpoll_poll_disable); 235 236 void netpoll_poll_enable(struct net_device *dev) 237 { 238 struct netpoll_info *ni; 239 rcu_read_lock(); 240 ni = rcu_dereference(dev->npinfo); 241 if (ni) 242 up(&ni->dev_lock); 243 rcu_read_unlock(); 244 } 245 EXPORT_SYMBOL(netpoll_poll_enable); 246 247 static void refill_skbs(void) 248 { 249 struct sk_buff *skb; 250 unsigned long flags; 251 252 spin_lock_irqsave(&skb_pool.lock, flags); 253 while (skb_pool.qlen < MAX_SKBS) { 254 skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC); 255 if (!skb) 256 break; 257 258 __skb_queue_tail(&skb_pool, skb); 259 } 260 spin_unlock_irqrestore(&skb_pool.lock, flags); 261 } 262 263 static void zap_completion_queue(void) 264 { 265 unsigned long flags; 266 struct softnet_data *sd = &get_cpu_var(softnet_data); 267 268 if (sd->completion_queue) { 269 struct sk_buff *clist; 270 271 local_irq_save(flags); 272 clist = sd->completion_queue; 273 sd->completion_queue = NULL; 274 local_irq_restore(flags); 275 276 while (clist != NULL) { 277 struct sk_buff *skb = clist; 278 clist = clist->next; 279 if (!skb_irq_freeable(skb)) { 280 atomic_inc(&skb->users); 281 dev_kfree_skb_any(skb); /* put this one back */ 282 } else { 283 __kfree_skb(skb); 284 } 285 } 286 } 287 288 put_cpu_var(softnet_data); 289 } 290 291 static struct sk_buff *find_skb(struct netpoll *np, int len, int reserve) 292 { 293 int count = 0; 294 struct sk_buff *skb; 295 296 zap_completion_queue(); 297 refill_skbs(); 298 repeat: 299 300 skb = alloc_skb(len, GFP_ATOMIC); 301 if (!skb) 302 skb = skb_dequeue(&skb_pool); 303 304 if (!skb) { 305 if (++count < 10) { 306 netpoll_poll_dev(np->dev); 307 goto repeat; 308 } 309 return NULL; 310 } 311 312 atomic_set(&skb->users, 1); 313 skb_reserve(skb, reserve); 314 return skb; 315 } 316 317 static int netpoll_owner_active(struct net_device *dev) 318 { 319 struct napi_struct *napi; 320 321 list_for_each_entry(napi, &dev->napi_list, dev_list) { 322 if (napi->poll_owner == smp_processor_id()) 323 return 1; 324 } 325 return 0; 326 } 327 328 /* call with IRQ disabled */ 329 void netpoll_send_skb_on_dev(struct netpoll *np, struct sk_buff *skb, 330 struct net_device *dev) 331 { 332 int status = NETDEV_TX_BUSY; 333 unsigned long tries; 334 /* It is up to the caller to keep npinfo alive. */ 335 struct netpoll_info *npinfo; 336 337 WARN_ON_ONCE(!irqs_disabled()); 338 339 npinfo = rcu_dereference_bh(np->dev->npinfo); 340 if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) { 341 dev_kfree_skb_irq(skb); 342 return; 343 } 344 345 /* don't get messages out of order, and no recursion */ 346 if (skb_queue_len(&npinfo->txq) == 0 && !netpoll_owner_active(dev)) { 347 struct netdev_queue *txq; 348 349 txq = netdev_pick_tx(dev, skb, NULL); 350 351 /* try until next clock tick */ 352 for (tries = jiffies_to_usecs(1)/USEC_PER_POLL; 353 tries > 0; --tries) { 354 if (HARD_TX_TRYLOCK(dev, txq)) { 355 if (!netif_xmit_stopped(txq)) 356 status = netpoll_start_xmit(skb, dev, txq); 357 358 HARD_TX_UNLOCK(dev, txq); 359 360 if (status == NETDEV_TX_OK) 361 break; 362 363 } 364 365 /* tickle device maybe there is some cleanup */ 366 netpoll_poll_dev(np->dev); 367 368 udelay(USEC_PER_POLL); 369 } 370 371 WARN_ONCE(!irqs_disabled(), 372 "netpoll_send_skb_on_dev(): %s enabled interrupts in poll (%pF)\n", 373 dev->name, dev->netdev_ops->ndo_start_xmit); 374 375 } 376 377 if (status != NETDEV_TX_OK) { 378 skb_queue_tail(&npinfo->txq, skb); 379 schedule_delayed_work(&npinfo->tx_work,0); 380 } 381 } 382 EXPORT_SYMBOL(netpoll_send_skb_on_dev); 383 384 void netpoll_send_udp(struct netpoll *np, const char *msg, int len) 385 { 386 int total_len, ip_len, udp_len; 387 struct sk_buff *skb; 388 struct udphdr *udph; 389 struct iphdr *iph; 390 struct ethhdr *eth; 391 static atomic_t ip_ident; 392 struct ipv6hdr *ip6h; 393 394 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 put_unaligned(0x60, (unsigned char *)ip6h); 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 = (struct ethhdr *) 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 put_unaligned(0x45, (unsigned char *)iph); 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 = (struct ethhdr *) 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 INIT_WORK(&np->cleanup_work, netpoll_async_cleanup); 615 616 if ((ndev->priv_flags & IFF_DISABLE_NETPOLL) || 617 !ndev->netdev_ops->ndo_poll_controller) { 618 np_err(np, "%s doesn't support polling, aborting\n", 619 np->dev_name); 620 err = -ENOTSUPP; 621 goto out; 622 } 623 624 if (!ndev->npinfo) { 625 npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL); 626 if (!npinfo) { 627 err = -ENOMEM; 628 goto out; 629 } 630 631 sema_init(&npinfo->dev_lock, 1); 632 skb_queue_head_init(&npinfo->txq); 633 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process); 634 635 atomic_set(&npinfo->refcnt, 1); 636 637 ops = np->dev->netdev_ops; 638 if (ops->ndo_netpoll_setup) { 639 err = ops->ndo_netpoll_setup(ndev, npinfo); 640 if (err) 641 goto free_npinfo; 642 } 643 } else { 644 npinfo = rtnl_dereference(ndev->npinfo); 645 atomic_inc(&npinfo->refcnt); 646 } 647 648 npinfo->netpoll = np; 649 650 /* last thing to do is link it to the net device structure */ 651 rcu_assign_pointer(ndev->npinfo, npinfo); 652 653 return 0; 654 655 free_npinfo: 656 kfree(npinfo); 657 out: 658 return err; 659 } 660 EXPORT_SYMBOL_GPL(__netpoll_setup); 661 662 int netpoll_setup(struct netpoll *np) 663 { 664 struct net_device *ndev = NULL; 665 struct in_device *in_dev; 666 int err; 667 668 rtnl_lock(); 669 if (np->dev_name) { 670 struct net *net = current->nsproxy->net_ns; 671 ndev = __dev_get_by_name(net, np->dev_name); 672 } 673 if (!ndev) { 674 np_err(np, "%s doesn't exist, aborting\n", np->dev_name); 675 err = -ENODEV; 676 goto unlock; 677 } 678 dev_hold(ndev); 679 680 if (netdev_master_upper_dev_get(ndev)) { 681 np_err(np, "%s is a slave device, aborting\n", np->dev_name); 682 err = -EBUSY; 683 goto put; 684 } 685 686 if (!netif_running(ndev)) { 687 unsigned long atmost, atleast; 688 689 np_info(np, "device %s not up yet, forcing it\n", np->dev_name); 690 691 err = dev_open(ndev); 692 693 if (err) { 694 np_err(np, "failed to open %s\n", ndev->name); 695 goto put; 696 } 697 698 rtnl_unlock(); 699 atleast = jiffies + HZ/10; 700 atmost = jiffies + carrier_timeout * HZ; 701 while (!netif_carrier_ok(ndev)) { 702 if (time_after(jiffies, atmost)) { 703 np_notice(np, "timeout waiting for carrier\n"); 704 break; 705 } 706 msleep(1); 707 } 708 709 /* If carrier appears to come up instantly, we don't 710 * trust it and pause so that we don't pump all our 711 * queued console messages into the bitbucket. 712 */ 713 714 if (time_before(jiffies, atleast)) { 715 np_notice(np, "carrier detect appears untrustworthy, waiting 4 seconds\n"); 716 msleep(4000); 717 } 718 rtnl_lock(); 719 } 720 721 if (!np->local_ip.ip) { 722 if (!np->ipv6) { 723 in_dev = __in_dev_get_rtnl(ndev); 724 725 if (!in_dev || !in_dev->ifa_list) { 726 np_err(np, "no IP address for %s, aborting\n", 727 np->dev_name); 728 err = -EDESTADDRREQ; 729 goto put; 730 } 731 732 np->local_ip.ip = in_dev->ifa_list->ifa_local; 733 np_info(np, "local IP %pI4\n", &np->local_ip.ip); 734 } else { 735 #if IS_ENABLED(CONFIG_IPV6) 736 struct inet6_dev *idev; 737 738 err = -EDESTADDRREQ; 739 idev = __in6_dev_get(ndev); 740 if (idev) { 741 struct inet6_ifaddr *ifp; 742 743 read_lock_bh(&idev->lock); 744 list_for_each_entry(ifp, &idev->addr_list, if_list) { 745 if (ipv6_addr_type(&ifp->addr) & IPV6_ADDR_LINKLOCAL) 746 continue; 747 np->local_ip.in6 = ifp->addr; 748 err = 0; 749 break; 750 } 751 read_unlock_bh(&idev->lock); 752 } 753 if (err) { 754 np_err(np, "no IPv6 address for %s, aborting\n", 755 np->dev_name); 756 goto put; 757 } else 758 np_info(np, "local IPv6 %pI6c\n", &np->local_ip.in6); 759 #else 760 np_err(np, "IPv6 is not supported %s, aborting\n", 761 np->dev_name); 762 err = -EINVAL; 763 goto put; 764 #endif 765 } 766 } 767 768 /* fill up the skb queue */ 769 refill_skbs(); 770 771 err = __netpoll_setup(np, ndev); 772 if (err) 773 goto put; 774 775 rtnl_unlock(); 776 return 0; 777 778 put: 779 dev_put(ndev); 780 unlock: 781 rtnl_unlock(); 782 return err; 783 } 784 EXPORT_SYMBOL(netpoll_setup); 785 786 static int __init netpoll_init(void) 787 { 788 skb_queue_head_init(&skb_pool); 789 return 0; 790 } 791 core_initcall(netpoll_init); 792 793 static void rcu_cleanup_netpoll_info(struct rcu_head *rcu_head) 794 { 795 struct netpoll_info *npinfo = 796 container_of(rcu_head, struct netpoll_info, rcu); 797 798 skb_queue_purge(&npinfo->txq); 799 800 /* we can't call cancel_delayed_work_sync here, as we are in softirq */ 801 cancel_delayed_work(&npinfo->tx_work); 802 803 /* clean after last, unfinished work */ 804 __skb_queue_purge(&npinfo->txq); 805 /* now cancel it again */ 806 cancel_delayed_work(&npinfo->tx_work); 807 kfree(npinfo); 808 } 809 810 void __netpoll_cleanup(struct netpoll *np) 811 { 812 struct netpoll_info *npinfo; 813 814 /* rtnl_dereference would be preferable here but 815 * rcu_cleanup_netpoll path can put us in here safely without 816 * holding the rtnl, so plain rcu_dereference it is 817 */ 818 npinfo = rtnl_dereference(np->dev->npinfo); 819 if (!npinfo) 820 return; 821 822 synchronize_srcu(&netpoll_srcu); 823 824 if (atomic_dec_and_test(&npinfo->refcnt)) { 825 const struct net_device_ops *ops; 826 827 ops = np->dev->netdev_ops; 828 if (ops->ndo_netpoll_cleanup) 829 ops->ndo_netpoll_cleanup(np->dev); 830 831 RCU_INIT_POINTER(np->dev->npinfo, NULL); 832 call_rcu_bh(&npinfo->rcu, rcu_cleanup_netpoll_info); 833 } else 834 RCU_INIT_POINTER(np->dev->npinfo, NULL); 835 } 836 EXPORT_SYMBOL_GPL(__netpoll_cleanup); 837 838 static void netpoll_async_cleanup(struct work_struct *work) 839 { 840 struct netpoll *np = container_of(work, struct netpoll, cleanup_work); 841 842 rtnl_lock(); 843 __netpoll_cleanup(np); 844 rtnl_unlock(); 845 kfree(np); 846 } 847 848 void __netpoll_free_async(struct netpoll *np) 849 { 850 schedule_work(&np->cleanup_work); 851 } 852 EXPORT_SYMBOL_GPL(__netpoll_free_async); 853 854 void netpoll_cleanup(struct netpoll *np) 855 { 856 rtnl_lock(); 857 if (!np->dev) 858 goto out; 859 __netpoll_cleanup(np); 860 dev_put(np->dev); 861 np->dev = NULL; 862 out: 863 rtnl_unlock(); 864 } 865 EXPORT_SYMBOL(netpoll_cleanup); 866