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