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 repeat: 288 289 skb = alloc_skb(len, GFP_ATOMIC); 290 if (!skb) { 291 skb = skb_dequeue(&np->skb_pool); 292 schedule_work(&np->refill_wq); 293 } 294 295 if (!skb) { 296 if (++count < 10) { 297 netpoll_poll_dev(np->dev); 298 goto repeat; 299 } 300 return NULL; 301 } 302 303 refcount_set(&skb->users, 1); 304 skb_reserve(skb, reserve); 305 return skb; 306 } 307 308 static int netpoll_owner_active(struct net_device *dev) 309 { 310 struct napi_struct *napi; 311 312 list_for_each_entry_rcu(napi, &dev->napi_list, dev_list) { 313 if (READ_ONCE(napi->poll_owner) == smp_processor_id()) 314 return 1; 315 } 316 return 0; 317 } 318 319 /* call with IRQ disabled */ 320 static netdev_tx_t __netpoll_send_skb(struct netpoll *np, struct sk_buff *skb) 321 { 322 netdev_tx_t status = NETDEV_TX_BUSY; 323 netdev_tx_t ret = NET_XMIT_DROP; 324 struct net_device *dev; 325 unsigned long tries; 326 /* It is up to the caller to keep npinfo alive. */ 327 struct netpoll_info *npinfo; 328 329 lockdep_assert_irqs_disabled(); 330 331 dev = np->dev; 332 rcu_read_lock(); 333 npinfo = rcu_dereference_bh(dev->npinfo); 334 335 if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) { 336 dev_kfree_skb_irq(skb); 337 goto out; 338 } 339 340 /* don't get messages out of order, and no recursion */ 341 if (skb_queue_len(&npinfo->txq) == 0 && !netpoll_owner_active(dev)) { 342 struct netdev_queue *txq; 343 344 txq = netdev_core_pick_tx(dev, skb, NULL); 345 346 /* try until next clock tick */ 347 for (tries = jiffies_to_usecs(1)/USEC_PER_POLL; 348 tries > 0; --tries) { 349 if (HARD_TX_TRYLOCK(dev, txq)) { 350 if (!netif_xmit_stopped(txq)) 351 status = netpoll_start_xmit(skb, dev, txq); 352 353 HARD_TX_UNLOCK(dev, txq); 354 355 if (dev_xmit_complete(status)) 356 break; 357 358 } 359 360 /* tickle device maybe there is some cleanup */ 361 netpoll_poll_dev(np->dev); 362 363 udelay(USEC_PER_POLL); 364 } 365 366 WARN_ONCE(!irqs_disabled(), 367 "netpoll_send_skb_on_dev(): %s enabled interrupts in poll (%pS)\n", 368 dev->name, dev->netdev_ops->ndo_start_xmit); 369 370 } 371 372 if (!dev_xmit_complete(status)) { 373 skb_queue_tail(&npinfo->txq, skb); 374 schedule_delayed_work(&npinfo->tx_work,0); 375 } 376 ret = NETDEV_TX_OK; 377 out: 378 rcu_read_unlock(); 379 return ret; 380 } 381 382 netdev_tx_t netpoll_send_skb(struct netpoll *np, struct sk_buff *skb) 383 { 384 unsigned long flags; 385 netdev_tx_t ret; 386 387 if (unlikely(!np)) { 388 dev_kfree_skb_irq(skb); 389 ret = NET_XMIT_DROP; 390 } else { 391 local_irq_save(flags); 392 ret = __netpoll_send_skb(np, skb); 393 local_irq_restore(flags); 394 } 395 return ret; 396 } 397 EXPORT_SYMBOL(netpoll_send_skb); 398 399 int netpoll_send_udp(struct netpoll *np, const char *msg, int len) 400 { 401 int total_len, ip_len, udp_len; 402 struct sk_buff *skb; 403 struct udphdr *udph; 404 struct iphdr *iph; 405 struct ethhdr *eth; 406 static atomic_t ip_ident; 407 struct ipv6hdr *ip6h; 408 409 if (!IS_ENABLED(CONFIG_PREEMPT_RT)) 410 WARN_ON_ONCE(!irqs_disabled()); 411 412 udp_len = len + sizeof(*udph); 413 if (np->ipv6) 414 ip_len = udp_len + sizeof(*ip6h); 415 else 416 ip_len = udp_len + sizeof(*iph); 417 418 total_len = ip_len + LL_RESERVED_SPACE(np->dev); 419 420 skb = find_skb(np, total_len + np->dev->needed_tailroom, 421 total_len - len); 422 if (!skb) 423 return -ENOMEM; 424 425 skb_copy_to_linear_data(skb, msg, len); 426 skb_put(skb, len); 427 428 skb_push(skb, sizeof(*udph)); 429 skb_reset_transport_header(skb); 430 udph = udp_hdr(skb); 431 udph->source = htons(np->local_port); 432 udph->dest = htons(np->remote_port); 433 udph->len = htons(udp_len); 434 435 if (np->ipv6) { 436 udph->check = 0; 437 udph->check = csum_ipv6_magic(&np->local_ip.in6, 438 &np->remote_ip.in6, 439 udp_len, IPPROTO_UDP, 440 csum_partial(udph, udp_len, 0)); 441 if (udph->check == 0) 442 udph->check = CSUM_MANGLED_0; 443 444 skb_push(skb, sizeof(*ip6h)); 445 skb_reset_network_header(skb); 446 ip6h = ipv6_hdr(skb); 447 448 /* ip6h->version = 6; ip6h->priority = 0; */ 449 *(unsigned char *)ip6h = 0x60; 450 ip6h->flow_lbl[0] = 0; 451 ip6h->flow_lbl[1] = 0; 452 ip6h->flow_lbl[2] = 0; 453 454 ip6h->payload_len = htons(sizeof(struct udphdr) + len); 455 ip6h->nexthdr = IPPROTO_UDP; 456 ip6h->hop_limit = 32; 457 ip6h->saddr = np->local_ip.in6; 458 ip6h->daddr = np->remote_ip.in6; 459 460 eth = skb_push(skb, ETH_HLEN); 461 skb_reset_mac_header(skb); 462 skb->protocol = eth->h_proto = htons(ETH_P_IPV6); 463 } else { 464 udph->check = 0; 465 udph->check = csum_tcpudp_magic(np->local_ip.ip, 466 np->remote_ip.ip, 467 udp_len, IPPROTO_UDP, 468 csum_partial(udph, udp_len, 0)); 469 if (udph->check == 0) 470 udph->check = CSUM_MANGLED_0; 471 472 skb_push(skb, sizeof(*iph)); 473 skb_reset_network_header(skb); 474 iph = ip_hdr(skb); 475 476 /* iph->version = 4; iph->ihl = 5; */ 477 *(unsigned char *)iph = 0x45; 478 iph->tos = 0; 479 put_unaligned(htons(ip_len), &(iph->tot_len)); 480 iph->id = htons(atomic_inc_return(&ip_ident)); 481 iph->frag_off = 0; 482 iph->ttl = 64; 483 iph->protocol = IPPROTO_UDP; 484 iph->check = 0; 485 put_unaligned(np->local_ip.ip, &(iph->saddr)); 486 put_unaligned(np->remote_ip.ip, &(iph->daddr)); 487 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); 488 489 eth = skb_push(skb, ETH_HLEN); 490 skb_reset_mac_header(skb); 491 skb->protocol = eth->h_proto = htons(ETH_P_IP); 492 } 493 494 ether_addr_copy(eth->h_source, np->dev->dev_addr); 495 ether_addr_copy(eth->h_dest, np->remote_mac); 496 497 skb->dev = np->dev; 498 499 return (int)netpoll_send_skb(np, skb); 500 } 501 EXPORT_SYMBOL(netpoll_send_udp); 502 503 void netpoll_print_options(struct netpoll *np) 504 { 505 np_info(np, "local port %d\n", np->local_port); 506 if (np->ipv6) 507 np_info(np, "local IPv6 address %pI6c\n", &np->local_ip.in6); 508 else 509 np_info(np, "local IPv4 address %pI4\n", &np->local_ip.ip); 510 np_info(np, "interface '%s'\n", np->dev_name); 511 np_info(np, "remote port %d\n", np->remote_port); 512 if (np->ipv6) 513 np_info(np, "remote IPv6 address %pI6c\n", &np->remote_ip.in6); 514 else 515 np_info(np, "remote IPv4 address %pI4\n", &np->remote_ip.ip); 516 np_info(np, "remote ethernet address %pM\n", np->remote_mac); 517 } 518 EXPORT_SYMBOL(netpoll_print_options); 519 520 static int netpoll_parse_ip_addr(const char *str, union inet_addr *addr) 521 { 522 const char *end; 523 524 if (!strchr(str, ':') && 525 in4_pton(str, -1, (void *)addr, -1, &end) > 0) { 526 if (!*end) 527 return 0; 528 } 529 if (in6_pton(str, -1, addr->in6.s6_addr, -1, &end) > 0) { 530 #if IS_ENABLED(CONFIG_IPV6) 531 if (!*end) 532 return 1; 533 #else 534 return -1; 535 #endif 536 } 537 return -1; 538 } 539 540 static void skb_pool_flush(struct netpoll *np) 541 { 542 struct sk_buff_head *skb_pool; 543 544 cancel_work_sync(&np->refill_wq); 545 skb_pool = &np->skb_pool; 546 skb_queue_purge_reason(skb_pool, SKB_CONSUMED); 547 } 548 549 int netpoll_parse_options(struct netpoll *np, char *opt) 550 { 551 char *cur=opt, *delim; 552 int ipv6; 553 bool ipversion_set = false; 554 555 if (*cur != '@') { 556 if ((delim = strchr(cur, '@')) == NULL) 557 goto parse_failed; 558 *delim = 0; 559 if (kstrtou16(cur, 10, &np->local_port)) 560 goto parse_failed; 561 cur = delim; 562 } 563 cur++; 564 565 if (*cur != '/') { 566 ipversion_set = true; 567 if ((delim = strchr(cur, '/')) == NULL) 568 goto parse_failed; 569 *delim = 0; 570 ipv6 = netpoll_parse_ip_addr(cur, &np->local_ip); 571 if (ipv6 < 0) 572 goto parse_failed; 573 else 574 np->ipv6 = (bool)ipv6; 575 cur = delim; 576 } 577 cur++; 578 579 if (*cur != ',') { 580 /* parse out dev name */ 581 if ((delim = strchr(cur, ',')) == NULL) 582 goto parse_failed; 583 *delim = 0; 584 strscpy(np->dev_name, cur, sizeof(np->dev_name)); 585 cur = delim; 586 } 587 cur++; 588 589 if (*cur != '@') { 590 /* dst port */ 591 if ((delim = strchr(cur, '@')) == NULL) 592 goto parse_failed; 593 *delim = 0; 594 if (*cur == ' ' || *cur == '\t') 595 np_info(np, "warning: whitespace is not allowed\n"); 596 if (kstrtou16(cur, 10, &np->remote_port)) 597 goto parse_failed; 598 cur = delim; 599 } 600 cur++; 601 602 /* dst ip */ 603 if ((delim = strchr(cur, '/')) == NULL) 604 goto parse_failed; 605 *delim = 0; 606 ipv6 = netpoll_parse_ip_addr(cur, &np->remote_ip); 607 if (ipv6 < 0) 608 goto parse_failed; 609 else if (ipversion_set && np->ipv6 != (bool)ipv6) 610 goto parse_failed; 611 else 612 np->ipv6 = (bool)ipv6; 613 cur = delim + 1; 614 615 if (*cur != 0) { 616 /* MAC address */ 617 if (!mac_pton(cur, np->remote_mac)) 618 goto parse_failed; 619 } 620 621 netpoll_print_options(np); 622 623 return 0; 624 625 parse_failed: 626 np_info(np, "couldn't parse config at '%s'!\n", cur); 627 return -1; 628 } 629 EXPORT_SYMBOL(netpoll_parse_options); 630 631 static void refill_skbs_work_handler(struct work_struct *work) 632 { 633 struct netpoll *np = 634 container_of(work, struct netpoll, refill_wq); 635 636 refill_skbs(np); 637 } 638 639 int __netpoll_setup(struct netpoll *np, struct net_device *ndev) 640 { 641 struct netpoll_info *npinfo; 642 const struct net_device_ops *ops; 643 int err; 644 645 skb_queue_head_init(&np->skb_pool); 646 647 if (ndev->priv_flags & IFF_DISABLE_NETPOLL) { 648 np_err(np, "%s doesn't support polling, aborting\n", 649 ndev->name); 650 err = -ENOTSUPP; 651 goto out; 652 } 653 654 npinfo = rtnl_dereference(ndev->npinfo); 655 if (!npinfo) { 656 npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL); 657 if (!npinfo) { 658 err = -ENOMEM; 659 goto out; 660 } 661 662 sema_init(&npinfo->dev_lock, 1); 663 skb_queue_head_init(&npinfo->txq); 664 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process); 665 666 refcount_set(&npinfo->refcnt, 1); 667 668 ops = ndev->netdev_ops; 669 if (ops->ndo_netpoll_setup) { 670 err = ops->ndo_netpoll_setup(ndev); 671 if (err) 672 goto free_npinfo; 673 } 674 } else { 675 refcount_inc(&npinfo->refcnt); 676 } 677 678 np->dev = ndev; 679 strscpy(np->dev_name, ndev->name, IFNAMSIZ); 680 npinfo->netpoll = np; 681 682 /* fill up the skb queue */ 683 refill_skbs(np); 684 INIT_WORK(&np->refill_wq, refill_skbs_work_handler); 685 686 /* last thing to do is link it to the net device structure */ 687 rcu_assign_pointer(ndev->npinfo, npinfo); 688 689 return 0; 690 691 free_npinfo: 692 kfree(npinfo); 693 out: 694 return err; 695 } 696 EXPORT_SYMBOL_GPL(__netpoll_setup); 697 698 int netpoll_setup(struct netpoll *np) 699 { 700 struct net_device *ndev = NULL; 701 bool ip_overwritten = false; 702 struct in_device *in_dev; 703 int err; 704 705 rtnl_lock(); 706 if (np->dev_name[0]) { 707 struct net *net = current->nsproxy->net_ns; 708 ndev = __dev_get_by_name(net, np->dev_name); 709 } 710 if (!ndev) { 711 np_err(np, "%s doesn't exist, aborting\n", np->dev_name); 712 err = -ENODEV; 713 goto unlock; 714 } 715 netdev_hold(ndev, &np->dev_tracker, GFP_KERNEL); 716 717 if (netdev_master_upper_dev_get(ndev)) { 718 np_err(np, "%s is a slave device, aborting\n", np->dev_name); 719 err = -EBUSY; 720 goto put; 721 } 722 723 if (!netif_running(ndev)) { 724 unsigned long atmost; 725 726 np_info(np, "device %s not up yet, forcing it\n", np->dev_name); 727 728 err = dev_open(ndev, NULL); 729 730 if (err) { 731 np_err(np, "failed to open %s\n", ndev->name); 732 goto put; 733 } 734 735 rtnl_unlock(); 736 atmost = jiffies + carrier_timeout * HZ; 737 while (!netif_carrier_ok(ndev)) { 738 if (time_after(jiffies, atmost)) { 739 np_notice(np, "timeout waiting for carrier\n"); 740 break; 741 } 742 msleep(1); 743 } 744 745 rtnl_lock(); 746 } 747 748 if (!np->local_ip.ip) { 749 if (!np->ipv6) { 750 const struct in_ifaddr *ifa; 751 752 in_dev = __in_dev_get_rtnl(ndev); 753 if (!in_dev) 754 goto put_noaddr; 755 756 ifa = rtnl_dereference(in_dev->ifa_list); 757 if (!ifa) { 758 put_noaddr: 759 np_err(np, "no IP address for %s, aborting\n", 760 np->dev_name); 761 err = -EDESTADDRREQ; 762 goto put; 763 } 764 765 np->local_ip.ip = ifa->ifa_local; 766 ip_overwritten = true; 767 np_info(np, "local IP %pI4\n", &np->local_ip.ip); 768 } else { 769 #if IS_ENABLED(CONFIG_IPV6) 770 struct inet6_dev *idev; 771 772 err = -EDESTADDRREQ; 773 idev = __in6_dev_get(ndev); 774 if (idev) { 775 struct inet6_ifaddr *ifp; 776 777 read_lock_bh(&idev->lock); 778 list_for_each_entry(ifp, &idev->addr_list, if_list) { 779 if (!!(ipv6_addr_type(&ifp->addr) & IPV6_ADDR_LINKLOCAL) != 780 !!(ipv6_addr_type(&np->remote_ip.in6) & IPV6_ADDR_LINKLOCAL)) 781 continue; 782 np->local_ip.in6 = ifp->addr; 783 ip_overwritten = true; 784 err = 0; 785 break; 786 } 787 read_unlock_bh(&idev->lock); 788 } 789 if (err) { 790 np_err(np, "no IPv6 address for %s, aborting\n", 791 np->dev_name); 792 goto put; 793 } else 794 np_info(np, "local IPv6 %pI6c\n", &np->local_ip.in6); 795 #else 796 np_err(np, "IPv6 is not supported %s, aborting\n", 797 np->dev_name); 798 err = -EINVAL; 799 goto put; 800 #endif 801 } 802 } 803 804 err = __netpoll_setup(np, ndev); 805 if (err) 806 goto flush; 807 rtnl_unlock(); 808 return 0; 809 810 flush: 811 skb_pool_flush(np); 812 put: 813 DEBUG_NET_WARN_ON_ONCE(np->dev); 814 if (ip_overwritten) 815 memset(&np->local_ip, 0, sizeof(np->local_ip)); 816 netdev_put(ndev, &np->dev_tracker); 817 unlock: 818 rtnl_unlock(); 819 return err; 820 } 821 EXPORT_SYMBOL(netpoll_setup); 822 823 static void rcu_cleanup_netpoll_info(struct rcu_head *rcu_head) 824 { 825 struct netpoll_info *npinfo = 826 container_of(rcu_head, struct netpoll_info, rcu); 827 828 skb_queue_purge(&npinfo->txq); 829 830 /* we can't call cancel_delayed_work_sync here, as we are in softirq */ 831 cancel_delayed_work(&npinfo->tx_work); 832 833 /* clean after last, unfinished work */ 834 __skb_queue_purge(&npinfo->txq); 835 /* now cancel it again */ 836 cancel_delayed_work(&npinfo->tx_work); 837 kfree(npinfo); 838 } 839 840 void __netpoll_cleanup(struct netpoll *np) 841 { 842 struct netpoll_info *npinfo; 843 844 npinfo = rtnl_dereference(np->dev->npinfo); 845 if (!npinfo) 846 return; 847 848 if (refcount_dec_and_test(&npinfo->refcnt)) { 849 const struct net_device_ops *ops; 850 851 ops = np->dev->netdev_ops; 852 if (ops->ndo_netpoll_cleanup) 853 ops->ndo_netpoll_cleanup(np->dev); 854 855 RCU_INIT_POINTER(np->dev->npinfo, NULL); 856 call_rcu(&npinfo->rcu, rcu_cleanup_netpoll_info); 857 } else 858 RCU_INIT_POINTER(np->dev->npinfo, NULL); 859 860 skb_pool_flush(np); 861 } 862 EXPORT_SYMBOL_GPL(__netpoll_cleanup); 863 864 void __netpoll_free(struct netpoll *np) 865 { 866 ASSERT_RTNL(); 867 868 /* Wait for transmitting packets to finish before freeing. */ 869 synchronize_rcu(); 870 __netpoll_cleanup(np); 871 kfree(np); 872 } 873 EXPORT_SYMBOL_GPL(__netpoll_free); 874 875 void do_netpoll_cleanup(struct netpoll *np) 876 { 877 __netpoll_cleanup(np); 878 netdev_put(np->dev, &np->dev_tracker); 879 np->dev = NULL; 880 } 881 EXPORT_SYMBOL(do_netpoll_cleanup); 882 883 void netpoll_cleanup(struct netpoll *np) 884 { 885 rtnl_lock(); 886 if (!np->dev) 887 goto out; 888 do_netpoll_cleanup(np); 889 out: 890 rtnl_unlock(); 891 } 892 EXPORT_SYMBOL(netpoll_cleanup); 893