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 <linux/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 #define USEC_PER_POLL 50 49 50 #define MAX_SKB_SIZE \ 51 (sizeof(struct ethhdr) + \ 52 sizeof(struct iphdr) + \ 53 sizeof(struct udphdr) + \ 54 MAX_UDP_CHUNK) 55 56 static void zap_completion_queue(void); 57 58 static unsigned int carrier_timeout = 4; 59 module_param(carrier_timeout, uint, 0644); 60 61 #define np_info(np, fmt, ...) \ 62 pr_info("%s: " fmt, np->name, ##__VA_ARGS__) 63 #define np_err(np, fmt, ...) \ 64 pr_err("%s: " fmt, np->name, ##__VA_ARGS__) 65 #define np_notice(np, fmt, ...) \ 66 pr_notice("%s: " fmt, np->name, ##__VA_ARGS__) 67 68 static netdev_tx_t netpoll_start_xmit(struct sk_buff *skb, 69 struct net_device *dev, 70 struct netdev_queue *txq) 71 { 72 netdev_tx_t status = NETDEV_TX_OK; 73 netdev_features_t features; 74 75 features = netif_skb_features(skb); 76 77 if (skb_vlan_tag_present(skb) && 78 !vlan_hw_offload_capable(features, skb->vlan_proto)) { 79 skb = __vlan_hwaccel_push_inside(skb); 80 if (unlikely(!skb)) { 81 /* This is actually a packet drop, but we 82 * don't want the code that calls this 83 * function to try and operate on a NULL skb. 84 */ 85 goto out; 86 } 87 } 88 89 status = netdev_start_xmit(skb, dev, txq, false); 90 91 out: 92 return status; 93 } 94 95 static void queue_process(struct work_struct *work) 96 { 97 struct netpoll_info *npinfo = 98 container_of(work, struct netpoll_info, tx_work.work); 99 struct sk_buff *skb; 100 unsigned long flags; 101 102 while ((skb = skb_dequeue(&npinfo->txq))) { 103 struct net_device *dev = skb->dev; 104 struct netdev_queue *txq; 105 unsigned int q_index; 106 107 if (!netif_device_present(dev) || !netif_running(dev)) { 108 kfree_skb(skb); 109 continue; 110 } 111 112 local_irq_save(flags); 113 /* check if skb->queue_mapping is still valid */ 114 q_index = skb_get_queue_mapping(skb); 115 if (unlikely(q_index >= dev->real_num_tx_queues)) { 116 q_index = q_index % dev->real_num_tx_queues; 117 skb_set_queue_mapping(skb, q_index); 118 } 119 txq = netdev_get_tx_queue(dev, q_index); 120 HARD_TX_LOCK(dev, txq, smp_processor_id()); 121 if (netif_xmit_frozen_or_stopped(txq) || 122 !dev_xmit_complete(netpoll_start_xmit(skb, dev, txq))) { 123 skb_queue_head(&npinfo->txq, skb); 124 HARD_TX_UNLOCK(dev, txq); 125 local_irq_restore(flags); 126 127 schedule_delayed_work(&npinfo->tx_work, HZ/10); 128 return; 129 } 130 HARD_TX_UNLOCK(dev, txq); 131 local_irq_restore(flags); 132 } 133 } 134 135 static int netif_local_xmit_active(struct net_device *dev) 136 { 137 int i; 138 139 for (i = 0; i < dev->num_tx_queues; i++) { 140 struct netdev_queue *txq = netdev_get_tx_queue(dev, i); 141 142 if (READ_ONCE(txq->xmit_lock_owner) == smp_processor_id()) 143 return 1; 144 } 145 146 return 0; 147 } 148 149 static void poll_one_napi(struct napi_struct *napi) 150 { 151 int work; 152 153 /* If we set this bit but see that it has already been set, 154 * that indicates that napi has been disabled and we need 155 * to abort this operation 156 */ 157 if (test_and_set_bit(NAPI_STATE_NPSVC, &napi->state)) 158 return; 159 160 /* We explicitly pass the polling call a budget of 0 to 161 * indicate that we are clearing the Tx path only. 162 */ 163 work = napi->poll(napi, 0); 164 WARN_ONCE(work, "%pS exceeded budget in poll\n", napi->poll); 165 trace_napi_poll(napi, work, 0); 166 167 clear_bit(NAPI_STATE_NPSVC, &napi->state); 168 } 169 170 static void poll_napi(struct net_device *dev) 171 { 172 struct napi_struct *napi; 173 int cpu = smp_processor_id(); 174 175 list_for_each_entry_rcu(napi, &dev->napi_list, dev_list) { 176 if (cmpxchg(&napi->poll_owner, -1, cpu) == -1) { 177 poll_one_napi(napi); 178 smp_store_release(&napi->poll_owner, -1); 179 } 180 } 181 } 182 183 void netpoll_poll_dev(struct net_device *dev) 184 { 185 struct netpoll_info *ni = rcu_dereference_bh(dev->npinfo); 186 const struct net_device_ops *ops; 187 188 /* Don't do any rx activity if the dev_lock mutex is held 189 * the dev_open/close paths use this to block netpoll activity 190 * while changing device state 191 */ 192 if (!ni || down_trylock(&ni->dev_lock)) 193 return; 194 195 /* Some drivers will take the same locks in poll and xmit, 196 * we can't poll if local CPU is already in xmit. 197 */ 198 if (!netif_running(dev) || netif_local_xmit_active(dev)) { 199 up(&ni->dev_lock); 200 return; 201 } 202 203 ops = dev->netdev_ops; 204 if (ops->ndo_poll_controller) 205 ops->ndo_poll_controller(dev); 206 207 poll_napi(dev); 208 209 up(&ni->dev_lock); 210 211 zap_completion_queue(); 212 } 213 EXPORT_SYMBOL(netpoll_poll_dev); 214 215 void netpoll_poll_disable(struct net_device *dev) 216 { 217 struct netpoll_info *ni; 218 219 might_sleep(); 220 ni = rtnl_dereference(dev->npinfo); 221 if (ni) 222 down(&ni->dev_lock); 223 } 224 225 void netpoll_poll_enable(struct net_device *dev) 226 { 227 struct netpoll_info *ni; 228 229 ni = rtnl_dereference(dev->npinfo); 230 if (ni) 231 up(&ni->dev_lock); 232 } 233 234 static void refill_skbs(struct netpoll *np) 235 { 236 struct sk_buff_head *skb_pool; 237 struct sk_buff *skb; 238 unsigned long flags; 239 240 skb_pool = &np->skb_pool; 241 242 spin_lock_irqsave(&skb_pool->lock, flags); 243 while (skb_pool->qlen < MAX_SKBS) { 244 skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC); 245 if (!skb) 246 break; 247 248 __skb_queue_tail(skb_pool, skb); 249 } 250 spin_unlock_irqrestore(&skb_pool->lock, flags); 251 } 252 253 static void zap_completion_queue(void) 254 { 255 unsigned long flags; 256 struct softnet_data *sd = &get_cpu_var(softnet_data); 257 258 if (sd->completion_queue) { 259 struct sk_buff *clist; 260 261 local_irq_save(flags); 262 clist = sd->completion_queue; 263 sd->completion_queue = NULL; 264 local_irq_restore(flags); 265 266 while (clist != NULL) { 267 struct sk_buff *skb = clist; 268 clist = clist->next; 269 if (!skb_irq_freeable(skb)) { 270 refcount_set(&skb->users, 1); 271 dev_kfree_skb_any(skb); /* put this one back */ 272 } else { 273 __kfree_skb(skb); 274 } 275 } 276 } 277 278 put_cpu_var(softnet_data); 279 } 280 281 static struct sk_buff *find_skb(struct netpoll *np, int len, int reserve) 282 { 283 int count = 0; 284 struct sk_buff *skb; 285 286 zap_completion_queue(); 287 refill_skbs(np); 288 repeat: 289 290 skb = alloc_skb(len, GFP_ATOMIC); 291 if (!skb) 292 skb = skb_dequeue(&np->skb_pool); 293 294 if (!skb) { 295 if (++count < 10) { 296 netpoll_poll_dev(np->dev); 297 goto repeat; 298 } 299 return NULL; 300 } 301 302 refcount_set(&skb->users, 1); 303 skb_reserve(skb, reserve); 304 return skb; 305 } 306 307 static int netpoll_owner_active(struct net_device *dev) 308 { 309 struct napi_struct *napi; 310 311 list_for_each_entry_rcu(napi, &dev->napi_list, dev_list) { 312 if (READ_ONCE(napi->poll_owner) == smp_processor_id()) 313 return 1; 314 } 315 return 0; 316 } 317 318 /* call with IRQ disabled */ 319 static netdev_tx_t __netpoll_send_skb(struct netpoll *np, struct sk_buff *skb) 320 { 321 netdev_tx_t status = NETDEV_TX_BUSY; 322 netdev_tx_t ret = NET_XMIT_DROP; 323 struct net_device *dev; 324 unsigned long tries; 325 /* It is up to the caller to keep npinfo alive. */ 326 struct netpoll_info *npinfo; 327 328 lockdep_assert_irqs_disabled(); 329 330 dev = np->dev; 331 rcu_read_lock(); 332 npinfo = rcu_dereference_bh(dev->npinfo); 333 334 if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) { 335 dev_kfree_skb_irq(skb); 336 goto out; 337 } 338 339 /* don't get messages out of order, and no recursion */ 340 if (skb_queue_len(&npinfo->txq) == 0 && !netpoll_owner_active(dev)) { 341 struct netdev_queue *txq; 342 343 txq = netdev_core_pick_tx(dev, skb, NULL); 344 345 /* try until next clock tick */ 346 for (tries = jiffies_to_usecs(1)/USEC_PER_POLL; 347 tries > 0; --tries) { 348 if (HARD_TX_TRYLOCK(dev, txq)) { 349 if (!netif_xmit_stopped(txq)) 350 status = netpoll_start_xmit(skb, dev, txq); 351 352 HARD_TX_UNLOCK(dev, txq); 353 354 if (dev_xmit_complete(status)) 355 break; 356 357 } 358 359 /* tickle device maybe there is some cleanup */ 360 netpoll_poll_dev(np->dev); 361 362 udelay(USEC_PER_POLL); 363 } 364 365 WARN_ONCE(!irqs_disabled(), 366 "netpoll_send_skb_on_dev(): %s enabled interrupts in poll (%pS)\n", 367 dev->name, dev->netdev_ops->ndo_start_xmit); 368 369 } 370 371 if (!dev_xmit_complete(status)) { 372 skb_queue_tail(&npinfo->txq, skb); 373 schedule_delayed_work(&npinfo->tx_work,0); 374 } 375 ret = NETDEV_TX_OK; 376 out: 377 rcu_read_unlock(); 378 return ret; 379 } 380 381 netdev_tx_t netpoll_send_skb(struct netpoll *np, struct sk_buff *skb) 382 { 383 unsigned long flags; 384 netdev_tx_t ret; 385 386 if (unlikely(!np)) { 387 dev_kfree_skb_irq(skb); 388 ret = NET_XMIT_DROP; 389 } else { 390 local_irq_save(flags); 391 ret = __netpoll_send_skb(np, skb); 392 local_irq_restore(flags); 393 } 394 return ret; 395 } 396 EXPORT_SYMBOL(netpoll_send_skb); 397 398 int netpoll_send_udp(struct netpoll *np, const char *msg, int len) 399 { 400 int total_len, ip_len, udp_len; 401 struct sk_buff *skb; 402 struct udphdr *udph; 403 struct iphdr *iph; 404 struct ethhdr *eth; 405 static atomic_t ip_ident; 406 struct ipv6hdr *ip6h; 407 408 if (!IS_ENABLED(CONFIG_PREEMPT_RT)) 409 WARN_ON_ONCE(!irqs_disabled()); 410 411 udp_len = len + sizeof(*udph); 412 if (np->ipv6) 413 ip_len = udp_len + sizeof(*ip6h); 414 else 415 ip_len = udp_len + sizeof(*iph); 416 417 total_len = ip_len + LL_RESERVED_SPACE(np->dev); 418 419 skb = find_skb(np, total_len + np->dev->needed_tailroom, 420 total_len - len); 421 if (!skb) 422 return -ENOMEM; 423 424 skb_copy_to_linear_data(skb, msg, len); 425 skb_put(skb, len); 426 427 skb_push(skb, sizeof(*udph)); 428 skb_reset_transport_header(skb); 429 udph = udp_hdr(skb); 430 udph->source = htons(np->local_port); 431 udph->dest = htons(np->remote_port); 432 udph->len = htons(udp_len); 433 434 if (np->ipv6) { 435 udph->check = 0; 436 udph->check = csum_ipv6_magic(&np->local_ip.in6, 437 &np->remote_ip.in6, 438 udp_len, IPPROTO_UDP, 439 csum_partial(udph, udp_len, 0)); 440 if (udph->check == 0) 441 udph->check = CSUM_MANGLED_0; 442 443 skb_push(skb, sizeof(*ip6h)); 444 skb_reset_network_header(skb); 445 ip6h = ipv6_hdr(skb); 446 447 /* ip6h->version = 6; ip6h->priority = 0; */ 448 *(unsigned char *)ip6h = 0x60; 449 ip6h->flow_lbl[0] = 0; 450 ip6h->flow_lbl[1] = 0; 451 ip6h->flow_lbl[2] = 0; 452 453 ip6h->payload_len = htons(sizeof(struct udphdr) + len); 454 ip6h->nexthdr = IPPROTO_UDP; 455 ip6h->hop_limit = 32; 456 ip6h->saddr = np->local_ip.in6; 457 ip6h->daddr = np->remote_ip.in6; 458 459 eth = skb_push(skb, ETH_HLEN); 460 skb_reset_mac_header(skb); 461 skb->protocol = eth->h_proto = htons(ETH_P_IPV6); 462 } else { 463 udph->check = 0; 464 udph->check = csum_tcpudp_magic(np->local_ip.ip, 465 np->remote_ip.ip, 466 udp_len, IPPROTO_UDP, 467 csum_partial(udph, udp_len, 0)); 468 if (udph->check == 0) 469 udph->check = CSUM_MANGLED_0; 470 471 skb_push(skb, sizeof(*iph)); 472 skb_reset_network_header(skb); 473 iph = ip_hdr(skb); 474 475 /* iph->version = 4; iph->ihl = 5; */ 476 *(unsigned char *)iph = 0x45; 477 iph->tos = 0; 478 put_unaligned(htons(ip_len), &(iph->tot_len)); 479 iph->id = htons(atomic_inc_return(&ip_ident)); 480 iph->frag_off = 0; 481 iph->ttl = 64; 482 iph->protocol = IPPROTO_UDP; 483 iph->check = 0; 484 put_unaligned(np->local_ip.ip, &(iph->saddr)); 485 put_unaligned(np->remote_ip.ip, &(iph->daddr)); 486 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); 487 488 eth = skb_push(skb, ETH_HLEN); 489 skb_reset_mac_header(skb); 490 skb->protocol = eth->h_proto = htons(ETH_P_IP); 491 } 492 493 ether_addr_copy(eth->h_source, np->dev->dev_addr); 494 ether_addr_copy(eth->h_dest, np->remote_mac); 495 496 skb->dev = np->dev; 497 498 return (int)netpoll_send_skb(np, skb); 499 } 500 EXPORT_SYMBOL(netpoll_send_udp); 501 502 void netpoll_print_options(struct netpoll *np) 503 { 504 np_info(np, "local port %d\n", np->local_port); 505 if (np->ipv6) 506 np_info(np, "local IPv6 address %pI6c\n", &np->local_ip.in6); 507 else 508 np_info(np, "local IPv4 address %pI4\n", &np->local_ip.ip); 509 np_info(np, "interface '%s'\n", np->dev_name); 510 np_info(np, "remote port %d\n", np->remote_port); 511 if (np->ipv6) 512 np_info(np, "remote IPv6 address %pI6c\n", &np->remote_ip.in6); 513 else 514 np_info(np, "remote IPv4 address %pI4\n", &np->remote_ip.ip); 515 np_info(np, "remote ethernet address %pM\n", np->remote_mac); 516 } 517 EXPORT_SYMBOL(netpoll_print_options); 518 519 static int netpoll_parse_ip_addr(const char *str, union inet_addr *addr) 520 { 521 const char *end; 522 523 if (!strchr(str, ':') && 524 in4_pton(str, -1, (void *)addr, -1, &end) > 0) { 525 if (!*end) 526 return 0; 527 } 528 if (in6_pton(str, -1, addr->in6.s6_addr, -1, &end) > 0) { 529 #if IS_ENABLED(CONFIG_IPV6) 530 if (!*end) 531 return 1; 532 #else 533 return -1; 534 #endif 535 } 536 return -1; 537 } 538 539 static void skb_pool_flush(struct netpoll *np) 540 { 541 struct sk_buff_head *skb_pool; 542 543 skb_pool = &np->skb_pool; 544 skb_queue_purge_reason(skb_pool, SKB_CONSUMED); 545 } 546 547 int netpoll_parse_options(struct netpoll *np, char *opt) 548 { 549 char *cur=opt, *delim; 550 int ipv6; 551 bool ipversion_set = false; 552 553 if (*cur != '@') { 554 if ((delim = strchr(cur, '@')) == NULL) 555 goto parse_failed; 556 *delim = 0; 557 if (kstrtou16(cur, 10, &np->local_port)) 558 goto parse_failed; 559 cur = delim; 560 } 561 cur++; 562 563 if (*cur != '/') { 564 ipversion_set = true; 565 if ((delim = strchr(cur, '/')) == NULL) 566 goto parse_failed; 567 *delim = 0; 568 ipv6 = netpoll_parse_ip_addr(cur, &np->local_ip); 569 if (ipv6 < 0) 570 goto parse_failed; 571 else 572 np->ipv6 = (bool)ipv6; 573 cur = delim; 574 } 575 cur++; 576 577 if (*cur != ',') { 578 /* parse out dev name */ 579 if ((delim = strchr(cur, ',')) == NULL) 580 goto parse_failed; 581 *delim = 0; 582 strscpy(np->dev_name, cur, sizeof(np->dev_name)); 583 cur = delim; 584 } 585 cur++; 586 587 if (*cur != '@') { 588 /* dst port */ 589 if ((delim = strchr(cur, '@')) == NULL) 590 goto parse_failed; 591 *delim = 0; 592 if (*cur == ' ' || *cur == '\t') 593 np_info(np, "warning: whitespace is not allowed\n"); 594 if (kstrtou16(cur, 10, &np->remote_port)) 595 goto parse_failed; 596 cur = delim; 597 } 598 cur++; 599 600 /* dst ip */ 601 if ((delim = strchr(cur, '/')) == NULL) 602 goto parse_failed; 603 *delim = 0; 604 ipv6 = netpoll_parse_ip_addr(cur, &np->remote_ip); 605 if (ipv6 < 0) 606 goto parse_failed; 607 else if (ipversion_set && np->ipv6 != (bool)ipv6) 608 goto parse_failed; 609 else 610 np->ipv6 = (bool)ipv6; 611 cur = delim + 1; 612 613 if (*cur != 0) { 614 /* MAC address */ 615 if (!mac_pton(cur, np->remote_mac)) 616 goto parse_failed; 617 } 618 619 netpoll_print_options(np); 620 621 return 0; 622 623 parse_failed: 624 np_info(np, "couldn't parse config at '%s'!\n", cur); 625 return -1; 626 } 627 EXPORT_SYMBOL(netpoll_parse_options); 628 629 int __netpoll_setup(struct netpoll *np, struct net_device *ndev) 630 { 631 struct netpoll_info *npinfo; 632 const struct net_device_ops *ops; 633 int err; 634 635 skb_queue_head_init(&np->skb_pool); 636 637 if (ndev->priv_flags & IFF_DISABLE_NETPOLL) { 638 np_err(np, "%s doesn't support polling, aborting\n", 639 ndev->name); 640 err = -ENOTSUPP; 641 goto out; 642 } 643 644 npinfo = rtnl_dereference(ndev->npinfo); 645 if (!npinfo) { 646 npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL); 647 if (!npinfo) { 648 err = -ENOMEM; 649 goto out; 650 } 651 652 sema_init(&npinfo->dev_lock, 1); 653 skb_queue_head_init(&npinfo->txq); 654 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process); 655 656 refcount_set(&npinfo->refcnt, 1); 657 658 ops = ndev->netdev_ops; 659 if (ops->ndo_netpoll_setup) { 660 err = ops->ndo_netpoll_setup(ndev); 661 if (err) 662 goto free_npinfo; 663 } 664 } else { 665 refcount_inc(&npinfo->refcnt); 666 } 667 668 np->dev = ndev; 669 strscpy(np->dev_name, ndev->name, IFNAMSIZ); 670 npinfo->netpoll = np; 671 672 /* fill up the skb queue */ 673 refill_skbs(np); 674 675 /* last thing to do is link it to the net device structure */ 676 rcu_assign_pointer(ndev->npinfo, npinfo); 677 678 return 0; 679 680 free_npinfo: 681 kfree(npinfo); 682 out: 683 return err; 684 } 685 EXPORT_SYMBOL_GPL(__netpoll_setup); 686 687 int netpoll_setup(struct netpoll *np) 688 { 689 struct net_device *ndev = NULL; 690 bool ip_overwritten = false; 691 struct in_device *in_dev; 692 int err; 693 694 rtnl_lock(); 695 if (np->dev_name[0]) { 696 struct net *net = current->nsproxy->net_ns; 697 ndev = __dev_get_by_name(net, np->dev_name); 698 } 699 if (!ndev) { 700 np_err(np, "%s doesn't exist, aborting\n", np->dev_name); 701 err = -ENODEV; 702 goto unlock; 703 } 704 netdev_hold(ndev, &np->dev_tracker, GFP_KERNEL); 705 706 if (netdev_master_upper_dev_get(ndev)) { 707 np_err(np, "%s is a slave device, aborting\n", np->dev_name); 708 err = -EBUSY; 709 goto put; 710 } 711 712 if (!netif_running(ndev)) { 713 unsigned long atmost; 714 715 np_info(np, "device %s not up yet, forcing it\n", np->dev_name); 716 717 err = dev_open(ndev, NULL); 718 719 if (err) { 720 np_err(np, "failed to open %s\n", ndev->name); 721 goto put; 722 } 723 724 rtnl_unlock(); 725 atmost = jiffies + carrier_timeout * HZ; 726 while (!netif_carrier_ok(ndev)) { 727 if (time_after(jiffies, atmost)) { 728 np_notice(np, "timeout waiting for carrier\n"); 729 break; 730 } 731 msleep(1); 732 } 733 734 rtnl_lock(); 735 } 736 737 if (!np->local_ip.ip) { 738 if (!np->ipv6) { 739 const struct in_ifaddr *ifa; 740 741 in_dev = __in_dev_get_rtnl(ndev); 742 if (!in_dev) 743 goto put_noaddr; 744 745 ifa = rtnl_dereference(in_dev->ifa_list); 746 if (!ifa) { 747 put_noaddr: 748 np_err(np, "no IP address for %s, aborting\n", 749 np->dev_name); 750 err = -EDESTADDRREQ; 751 goto put; 752 } 753 754 np->local_ip.ip = ifa->ifa_local; 755 ip_overwritten = true; 756 np_info(np, "local IP %pI4\n", &np->local_ip.ip); 757 } else { 758 #if IS_ENABLED(CONFIG_IPV6) 759 struct inet6_dev *idev; 760 761 err = -EDESTADDRREQ; 762 idev = __in6_dev_get(ndev); 763 if (idev) { 764 struct inet6_ifaddr *ifp; 765 766 read_lock_bh(&idev->lock); 767 list_for_each_entry(ifp, &idev->addr_list, if_list) { 768 if (!!(ipv6_addr_type(&ifp->addr) & IPV6_ADDR_LINKLOCAL) != 769 !!(ipv6_addr_type(&np->remote_ip.in6) & IPV6_ADDR_LINKLOCAL)) 770 continue; 771 np->local_ip.in6 = ifp->addr; 772 ip_overwritten = true; 773 err = 0; 774 break; 775 } 776 read_unlock_bh(&idev->lock); 777 } 778 if (err) { 779 np_err(np, "no IPv6 address for %s, aborting\n", 780 np->dev_name); 781 goto put; 782 } else 783 np_info(np, "local IPv6 %pI6c\n", &np->local_ip.in6); 784 #else 785 np_err(np, "IPv6 is not supported %s, aborting\n", 786 np->dev_name); 787 err = -EINVAL; 788 goto put; 789 #endif 790 } 791 } 792 793 err = __netpoll_setup(np, ndev); 794 if (err) 795 goto flush; 796 rtnl_unlock(); 797 return 0; 798 799 flush: 800 skb_pool_flush(np); 801 put: 802 DEBUG_NET_WARN_ON_ONCE(np->dev); 803 if (ip_overwritten) 804 memset(&np->local_ip, 0, sizeof(np->local_ip)); 805 netdev_put(ndev, &np->dev_tracker); 806 unlock: 807 rtnl_unlock(); 808 return err; 809 } 810 EXPORT_SYMBOL(netpoll_setup); 811 812 static void rcu_cleanup_netpoll_info(struct rcu_head *rcu_head) 813 { 814 struct netpoll_info *npinfo = 815 container_of(rcu_head, struct netpoll_info, rcu); 816 817 skb_queue_purge(&npinfo->txq); 818 819 /* we can't call cancel_delayed_work_sync here, as we are in softirq */ 820 cancel_delayed_work(&npinfo->tx_work); 821 822 /* clean after last, unfinished work */ 823 __skb_queue_purge(&npinfo->txq); 824 /* now cancel it again */ 825 cancel_delayed_work(&npinfo->tx_work); 826 kfree(npinfo); 827 } 828 829 void __netpoll_cleanup(struct netpoll *np) 830 { 831 struct netpoll_info *npinfo; 832 833 npinfo = rtnl_dereference(np->dev->npinfo); 834 if (!npinfo) 835 return; 836 837 if (refcount_dec_and_test(&npinfo->refcnt)) { 838 const struct net_device_ops *ops; 839 840 ops = np->dev->netdev_ops; 841 if (ops->ndo_netpoll_cleanup) 842 ops->ndo_netpoll_cleanup(np->dev); 843 844 RCU_INIT_POINTER(np->dev->npinfo, NULL); 845 call_rcu(&npinfo->rcu, rcu_cleanup_netpoll_info); 846 } else 847 RCU_INIT_POINTER(np->dev->npinfo, NULL); 848 849 skb_pool_flush(np); 850 } 851 EXPORT_SYMBOL_GPL(__netpoll_cleanup); 852 853 void __netpoll_free(struct netpoll *np) 854 { 855 ASSERT_RTNL(); 856 857 /* Wait for transmitting packets to finish before freeing. */ 858 synchronize_rcu(); 859 __netpoll_cleanup(np); 860 kfree(np); 861 } 862 EXPORT_SYMBOL_GPL(__netpoll_free); 863 864 void do_netpoll_cleanup(struct netpoll *np) 865 { 866 __netpoll_cleanup(np); 867 netdev_put(np->dev, &np->dev_tracker); 868 np->dev = NULL; 869 } 870 EXPORT_SYMBOL(do_netpoll_cleanup); 871 872 void netpoll_cleanup(struct netpoll *np) 873 { 874 rtnl_lock(); 875 if (!np->dev) 876 goto out; 877 do_netpoll_cleanup(np); 878 out: 879 rtnl_unlock(); 880 } 881 EXPORT_SYMBOL(netpoll_cleanup); 882