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