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 #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 49 static struct sk_buff_head skb_pool; 50 51 DEFINE_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 61 static void zap_completion_queue(void); 62 63 static unsigned int carrier_timeout = 4; 64 module_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 73 static 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 96 out: 97 return status; 98 } 99 100 static 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 } 139 140 static 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 } 153 154 static 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 } 174 175 static 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 } 187 188 void 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 } 218 EXPORT_SYMBOL(netpoll_poll_dev); 219 220 void 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 } 231 EXPORT_SYMBOL(netpoll_poll_disable); 232 233 void 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 } 242 EXPORT_SYMBOL(netpoll_poll_enable); 243 244 static 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 } 259 260 static 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 } 287 288 static 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(); 295 repeat: 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 } 313 314 static 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 (READ_ONCE(napi->poll_owner) == smp_processor_id()) 320 return 1; 321 } 322 return 0; 323 } 324 325 /* call with IRQ disabled */ 326 static netdev_tx_t __netpoll_send_skb(struct netpoll *np, struct sk_buff *skb) 327 { 328 netdev_tx_t status = NETDEV_TX_BUSY; 329 netdev_tx_t ret = NET_XMIT_DROP; 330 struct net_device *dev; 331 unsigned long tries; 332 /* It is up to the caller to keep npinfo alive. */ 333 struct netpoll_info *npinfo; 334 335 lockdep_assert_irqs_disabled(); 336 337 dev = np->dev; 338 rcu_read_lock(); 339 npinfo = rcu_dereference_bh(dev->npinfo); 340 341 if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) { 342 dev_kfree_skb_irq(skb); 343 goto out; 344 } 345 346 /* don't get messages out of order, and no recursion */ 347 if (skb_queue_len(&npinfo->txq) == 0 && !netpoll_owner_active(dev)) { 348 struct netdev_queue *txq; 349 350 txq = netdev_core_pick_tx(dev, skb, NULL); 351 352 /* try until next clock tick */ 353 for (tries = jiffies_to_usecs(1)/USEC_PER_POLL; 354 tries > 0; --tries) { 355 if (HARD_TX_TRYLOCK(dev, txq)) { 356 if (!netif_xmit_stopped(txq)) 357 status = netpoll_start_xmit(skb, dev, txq); 358 359 HARD_TX_UNLOCK(dev, txq); 360 361 if (dev_xmit_complete(status)) 362 break; 363 364 } 365 366 /* tickle device maybe there is some cleanup */ 367 netpoll_poll_dev(np->dev); 368 369 udelay(USEC_PER_POLL); 370 } 371 372 WARN_ONCE(!irqs_disabled(), 373 "netpoll_send_skb_on_dev(): %s enabled interrupts in poll (%pS)\n", 374 dev->name, dev->netdev_ops->ndo_start_xmit); 375 376 } 377 378 if (!dev_xmit_complete(status)) { 379 skb_queue_tail(&npinfo->txq, skb); 380 schedule_delayed_work(&npinfo->tx_work,0); 381 } 382 ret = NETDEV_TX_OK; 383 out: 384 rcu_read_unlock(); 385 return ret; 386 } 387 388 netdev_tx_t netpoll_send_skb(struct netpoll *np, struct sk_buff *skb) 389 { 390 unsigned long flags; 391 netdev_tx_t ret; 392 393 if (unlikely(!np)) { 394 dev_kfree_skb_irq(skb); 395 ret = NET_XMIT_DROP; 396 } else { 397 local_irq_save(flags); 398 ret = __netpoll_send_skb(np, skb); 399 local_irq_restore(flags); 400 } 401 return ret; 402 } 403 EXPORT_SYMBOL(netpoll_send_skb); 404 405 void netpoll_send_udp(struct netpoll *np, const char *msg, int len) 406 { 407 int total_len, ip_len, udp_len; 408 struct sk_buff *skb; 409 struct udphdr *udph; 410 struct iphdr *iph; 411 struct ethhdr *eth; 412 static atomic_t ip_ident; 413 struct ipv6hdr *ip6h; 414 415 if (!IS_ENABLED(CONFIG_PREEMPT_RT)) 416 WARN_ON_ONCE(!irqs_disabled()); 417 418 udp_len = len + sizeof(*udph); 419 if (np->ipv6) 420 ip_len = udp_len + sizeof(*ip6h); 421 else 422 ip_len = udp_len + sizeof(*iph); 423 424 total_len = ip_len + LL_RESERVED_SPACE(np->dev); 425 426 skb = find_skb(np, total_len + np->dev->needed_tailroom, 427 total_len - len); 428 if (!skb) 429 return; 430 431 skb_copy_to_linear_data(skb, msg, len); 432 skb_put(skb, len); 433 434 skb_push(skb, sizeof(*udph)); 435 skb_reset_transport_header(skb); 436 udph = udp_hdr(skb); 437 udph->source = htons(np->local_port); 438 udph->dest = htons(np->remote_port); 439 udph->len = htons(udp_len); 440 441 if (np->ipv6) { 442 udph->check = 0; 443 udph->check = csum_ipv6_magic(&np->local_ip.in6, 444 &np->remote_ip.in6, 445 udp_len, IPPROTO_UDP, 446 csum_partial(udph, udp_len, 0)); 447 if (udph->check == 0) 448 udph->check = CSUM_MANGLED_0; 449 450 skb_push(skb, sizeof(*ip6h)); 451 skb_reset_network_header(skb); 452 ip6h = ipv6_hdr(skb); 453 454 /* ip6h->version = 6; ip6h->priority = 0; */ 455 *(unsigned char *)ip6h = 0x60; 456 ip6h->flow_lbl[0] = 0; 457 ip6h->flow_lbl[1] = 0; 458 ip6h->flow_lbl[2] = 0; 459 460 ip6h->payload_len = htons(sizeof(struct udphdr) + len); 461 ip6h->nexthdr = IPPROTO_UDP; 462 ip6h->hop_limit = 32; 463 ip6h->saddr = np->local_ip.in6; 464 ip6h->daddr = np->remote_ip.in6; 465 466 eth = skb_push(skb, ETH_HLEN); 467 skb_reset_mac_header(skb); 468 skb->protocol = eth->h_proto = htons(ETH_P_IPV6); 469 } else { 470 udph->check = 0; 471 udph->check = csum_tcpudp_magic(np->local_ip.ip, 472 np->remote_ip.ip, 473 udp_len, IPPROTO_UDP, 474 csum_partial(udph, udp_len, 0)); 475 if (udph->check == 0) 476 udph->check = CSUM_MANGLED_0; 477 478 skb_push(skb, sizeof(*iph)); 479 skb_reset_network_header(skb); 480 iph = ip_hdr(skb); 481 482 /* iph->version = 4; iph->ihl = 5; */ 483 *(unsigned char *)iph = 0x45; 484 iph->tos = 0; 485 put_unaligned(htons(ip_len), &(iph->tot_len)); 486 iph->id = htons(atomic_inc_return(&ip_ident)); 487 iph->frag_off = 0; 488 iph->ttl = 64; 489 iph->protocol = IPPROTO_UDP; 490 iph->check = 0; 491 put_unaligned(np->local_ip.ip, &(iph->saddr)); 492 put_unaligned(np->remote_ip.ip, &(iph->daddr)); 493 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); 494 495 eth = skb_push(skb, ETH_HLEN); 496 skb_reset_mac_header(skb); 497 skb->protocol = eth->h_proto = htons(ETH_P_IP); 498 } 499 500 ether_addr_copy(eth->h_source, np->dev->dev_addr); 501 ether_addr_copy(eth->h_dest, np->remote_mac); 502 503 skb->dev = np->dev; 504 505 netpoll_send_skb(np, skb); 506 } 507 EXPORT_SYMBOL(netpoll_send_udp); 508 509 void netpoll_print_options(struct netpoll *np) 510 { 511 np_info(np, "local port %d\n", np->local_port); 512 if (np->ipv6) 513 np_info(np, "local IPv6 address %pI6c\n", &np->local_ip.in6); 514 else 515 np_info(np, "local IPv4 address %pI4\n", &np->local_ip.ip); 516 np_info(np, "interface '%s'\n", np->dev_name); 517 np_info(np, "remote port %d\n", np->remote_port); 518 if (np->ipv6) 519 np_info(np, "remote IPv6 address %pI6c\n", &np->remote_ip.in6); 520 else 521 np_info(np, "remote IPv4 address %pI4\n", &np->remote_ip.ip); 522 np_info(np, "remote ethernet address %pM\n", np->remote_mac); 523 } 524 EXPORT_SYMBOL(netpoll_print_options); 525 526 static int netpoll_parse_ip_addr(const char *str, union inet_addr *addr) 527 { 528 const char *end; 529 530 if (!strchr(str, ':') && 531 in4_pton(str, -1, (void *)addr, -1, &end) > 0) { 532 if (!*end) 533 return 0; 534 } 535 if (in6_pton(str, -1, addr->in6.s6_addr, -1, &end) > 0) { 536 #if IS_ENABLED(CONFIG_IPV6) 537 if (!*end) 538 return 1; 539 #else 540 return -1; 541 #endif 542 } 543 return -1; 544 } 545 546 int netpoll_parse_options(struct netpoll *np, char *opt) 547 { 548 char *cur=opt, *delim; 549 int ipv6; 550 bool ipversion_set = false; 551 552 if (*cur != '@') { 553 if ((delim = strchr(cur, '@')) == NULL) 554 goto parse_failed; 555 *delim = 0; 556 if (kstrtou16(cur, 10, &np->local_port)) 557 goto parse_failed; 558 cur = delim; 559 } 560 cur++; 561 562 if (*cur != '/') { 563 ipversion_set = true; 564 if ((delim = strchr(cur, '/')) == NULL) 565 goto parse_failed; 566 *delim = 0; 567 ipv6 = netpoll_parse_ip_addr(cur, &np->local_ip); 568 if (ipv6 < 0) 569 goto parse_failed; 570 else 571 np->ipv6 = (bool)ipv6; 572 cur = delim; 573 } 574 cur++; 575 576 if (*cur != ',') { 577 /* parse out dev name */ 578 if ((delim = strchr(cur, ',')) == NULL) 579 goto parse_failed; 580 *delim = 0; 581 strscpy(np->dev_name, cur, sizeof(np->dev_name)); 582 cur = delim; 583 } 584 cur++; 585 586 if (*cur != '@') { 587 /* dst port */ 588 if ((delim = strchr(cur, '@')) == NULL) 589 goto parse_failed; 590 *delim = 0; 591 if (*cur == ' ' || *cur == '\t') 592 np_info(np, "warning: whitespace is not allowed\n"); 593 if (kstrtou16(cur, 10, &np->remote_port)) 594 goto parse_failed; 595 cur = delim; 596 } 597 cur++; 598 599 /* dst ip */ 600 if ((delim = strchr(cur, '/')) == NULL) 601 goto parse_failed; 602 *delim = 0; 603 ipv6 = netpoll_parse_ip_addr(cur, &np->remote_ip); 604 if (ipv6 < 0) 605 goto parse_failed; 606 else if (ipversion_set && np->ipv6 != (bool)ipv6) 607 goto parse_failed; 608 else 609 np->ipv6 = (bool)ipv6; 610 cur = delim + 1; 611 612 if (*cur != 0) { 613 /* MAC address */ 614 if (!mac_pton(cur, np->remote_mac)) 615 goto parse_failed; 616 } 617 618 netpoll_print_options(np); 619 620 return 0; 621 622 parse_failed: 623 np_info(np, "couldn't parse config at '%s'!\n", cur); 624 return -1; 625 } 626 EXPORT_SYMBOL(netpoll_parse_options); 627 628 int __netpoll_setup(struct netpoll *np, struct net_device *ndev) 629 { 630 struct netpoll_info *npinfo; 631 const struct net_device_ops *ops; 632 int err; 633 634 if (ndev->priv_flags & IFF_DISABLE_NETPOLL) { 635 np_err(np, "%s doesn't support polling, aborting\n", 636 ndev->name); 637 err = -ENOTSUPP; 638 goto out; 639 } 640 641 if (!rcu_access_pointer(ndev->npinfo)) { 642 npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL); 643 if (!npinfo) { 644 err = -ENOMEM; 645 goto out; 646 } 647 648 sema_init(&npinfo->dev_lock, 1); 649 skb_queue_head_init(&npinfo->txq); 650 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process); 651 652 refcount_set(&npinfo->refcnt, 1); 653 654 ops = ndev->netdev_ops; 655 if (ops->ndo_netpoll_setup) { 656 err = ops->ndo_netpoll_setup(ndev, npinfo); 657 if (err) 658 goto free_npinfo; 659 } 660 } else { 661 npinfo = rtnl_dereference(ndev->npinfo); 662 refcount_inc(&npinfo->refcnt); 663 } 664 665 np->dev = ndev; 666 strscpy(np->dev_name, ndev->name, IFNAMSIZ); 667 npinfo->netpoll = np; 668 669 /* last thing to do is link it to the net device structure */ 670 rcu_assign_pointer(ndev->npinfo, npinfo); 671 672 return 0; 673 674 free_npinfo: 675 kfree(npinfo); 676 out: 677 return err; 678 } 679 EXPORT_SYMBOL_GPL(__netpoll_setup); 680 681 int netpoll_setup(struct netpoll *np) 682 { 683 struct net_device *ndev = NULL; 684 bool ip_overwritten = false; 685 struct in_device *in_dev; 686 int err; 687 688 rtnl_lock(); 689 if (np->dev_name[0]) { 690 struct net *net = current->nsproxy->net_ns; 691 ndev = __dev_get_by_name(net, np->dev_name); 692 } 693 if (!ndev) { 694 np_err(np, "%s doesn't exist, aborting\n", np->dev_name); 695 err = -ENODEV; 696 goto unlock; 697 } 698 netdev_hold(ndev, &np->dev_tracker, GFP_KERNEL); 699 700 if (netdev_master_upper_dev_get(ndev)) { 701 np_err(np, "%s is a slave device, aborting\n", np->dev_name); 702 err = -EBUSY; 703 goto put; 704 } 705 706 if (!netif_running(ndev)) { 707 unsigned long atmost; 708 709 np_info(np, "device %s not up yet, forcing it\n", np->dev_name); 710 711 err = dev_open(ndev, NULL); 712 713 if (err) { 714 np_err(np, "failed to open %s\n", ndev->name); 715 goto put; 716 } 717 718 rtnl_unlock(); 719 atmost = jiffies + carrier_timeout * HZ; 720 while (!netif_carrier_ok(ndev)) { 721 if (time_after(jiffies, atmost)) { 722 np_notice(np, "timeout waiting for carrier\n"); 723 break; 724 } 725 msleep(1); 726 } 727 728 rtnl_lock(); 729 } 730 731 if (!np->local_ip.ip) { 732 if (!np->ipv6) { 733 const struct in_ifaddr *ifa; 734 735 in_dev = __in_dev_get_rtnl(ndev); 736 if (!in_dev) 737 goto put_noaddr; 738 739 ifa = rtnl_dereference(in_dev->ifa_list); 740 if (!ifa) { 741 put_noaddr: 742 np_err(np, "no IP address for %s, aborting\n", 743 np->dev_name); 744 err = -EDESTADDRREQ; 745 goto put; 746 } 747 748 np->local_ip.ip = ifa->ifa_local; 749 ip_overwritten = true; 750 np_info(np, "local IP %pI4\n", &np->local_ip.ip); 751 } else { 752 #if IS_ENABLED(CONFIG_IPV6) 753 struct inet6_dev *idev; 754 755 err = -EDESTADDRREQ; 756 idev = __in6_dev_get(ndev); 757 if (idev) { 758 struct inet6_ifaddr *ifp; 759 760 read_lock_bh(&idev->lock); 761 list_for_each_entry(ifp, &idev->addr_list, if_list) { 762 if (!!(ipv6_addr_type(&ifp->addr) & IPV6_ADDR_LINKLOCAL) != 763 !!(ipv6_addr_type(&np->remote_ip.in6) & IPV6_ADDR_LINKLOCAL)) 764 continue; 765 np->local_ip.in6 = ifp->addr; 766 ip_overwritten = true; 767 err = 0; 768 break; 769 } 770 read_unlock_bh(&idev->lock); 771 } 772 if (err) { 773 np_err(np, "no IPv6 address for %s, aborting\n", 774 np->dev_name); 775 goto put; 776 } else 777 np_info(np, "local IPv6 %pI6c\n", &np->local_ip.in6); 778 #else 779 np_err(np, "IPv6 is not supported %s, aborting\n", 780 np->dev_name); 781 err = -EINVAL; 782 goto put; 783 #endif 784 } 785 } 786 787 /* fill up the skb queue */ 788 refill_skbs(); 789 790 err = __netpoll_setup(np, ndev); 791 if (err) 792 goto put; 793 rtnl_unlock(); 794 return 0; 795 796 put: 797 DEBUG_NET_WARN_ON_ONCE(np->dev); 798 if (ip_overwritten) 799 memset(&np->local_ip, 0, sizeof(np->local_ip)); 800 netdev_put(ndev, &np->dev_tracker); 801 unlock: 802 rtnl_unlock(); 803 return err; 804 } 805 EXPORT_SYMBOL(netpoll_setup); 806 807 static int __init netpoll_init(void) 808 { 809 skb_queue_head_init(&skb_pool); 810 return 0; 811 } 812 core_initcall(netpoll_init); 813 814 static void rcu_cleanup_netpoll_info(struct rcu_head *rcu_head) 815 { 816 struct netpoll_info *npinfo = 817 container_of(rcu_head, struct netpoll_info, rcu); 818 819 skb_queue_purge(&npinfo->txq); 820 821 /* we can't call cancel_delayed_work_sync here, as we are in softirq */ 822 cancel_delayed_work(&npinfo->tx_work); 823 824 /* clean after last, unfinished work */ 825 __skb_queue_purge(&npinfo->txq); 826 /* now cancel it again */ 827 cancel_delayed_work(&npinfo->tx_work); 828 kfree(npinfo); 829 } 830 831 void __netpoll_cleanup(struct netpoll *np) 832 { 833 struct netpoll_info *npinfo; 834 835 npinfo = rtnl_dereference(np->dev->npinfo); 836 if (!npinfo) 837 return; 838 839 synchronize_srcu(&netpoll_srcu); 840 841 if (refcount_dec_and_test(&npinfo->refcnt)) { 842 const struct net_device_ops *ops; 843 844 ops = np->dev->netdev_ops; 845 if (ops->ndo_netpoll_cleanup) 846 ops->ndo_netpoll_cleanup(np->dev); 847 848 RCU_INIT_POINTER(np->dev->npinfo, NULL); 849 call_rcu(&npinfo->rcu, rcu_cleanup_netpoll_info); 850 } else 851 RCU_INIT_POINTER(np->dev->npinfo, NULL); 852 } 853 EXPORT_SYMBOL_GPL(__netpoll_cleanup); 854 855 void __netpoll_free(struct netpoll *np) 856 { 857 ASSERT_RTNL(); 858 859 /* Wait for transmitting packets to finish before freeing. */ 860 synchronize_rcu(); 861 __netpoll_cleanup(np); 862 kfree(np); 863 } 864 EXPORT_SYMBOL_GPL(__netpoll_free); 865 866 void netpoll_cleanup(struct netpoll *np) 867 { 868 rtnl_lock(); 869 if (!np->dev) 870 goto out; 871 __netpoll_cleanup(np); 872 netdev_put(np->dev, &np->dev_tracker); 873 np->dev = NULL; 874 out: 875 rtnl_unlock(); 876 } 877 EXPORT_SYMBOL(netpoll_cleanup); 878