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 <[email protected]> 6 * 7 * based on the netconsole code from: 8 * 9 * Copyright (C) 2001 Ingo Molnar <[email protected]> 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 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 npinfo = rcu_dereference_bh(dev->npinfo); 332 333 if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) { 334 dev_kfree_skb_irq(skb); 335 return NET_XMIT_DROP; 336 } 337 338 /* don't get messages out of order, and no recursion */ 339 if (skb_queue_len(&npinfo->txq) == 0 && !netpoll_owner_active(dev)) { 340 struct netdev_queue *txq; 341 342 txq = netdev_core_pick_tx(dev, skb, NULL); 343 344 /* try until next clock tick */ 345 for (tries = jiffies_to_usecs(1)/USEC_PER_POLL; 346 tries > 0; --tries) { 347 if (HARD_TX_TRYLOCK(dev, txq)) { 348 if (!netif_xmit_stopped(txq)) 349 status = netpoll_start_xmit(skb, dev, txq); 350 351 HARD_TX_UNLOCK(dev, txq); 352 353 if (dev_xmit_complete(status)) 354 break; 355 356 } 357 358 /* tickle device maybe there is some cleanup */ 359 netpoll_poll_dev(np->dev); 360 361 udelay(USEC_PER_POLL); 362 } 363 364 WARN_ONCE(!irqs_disabled(), 365 "netpoll_send_skb_on_dev(): %s enabled interrupts in poll (%pS)\n", 366 dev->name, dev->netdev_ops->ndo_start_xmit); 367 368 } 369 370 if (!dev_xmit_complete(status)) { 371 skb_queue_tail(&npinfo->txq, skb); 372 schedule_delayed_work(&npinfo->tx_work,0); 373 } 374 return NETDEV_TX_OK; 375 } 376 377 netdev_tx_t netpoll_send_skb(struct netpoll *np, struct sk_buff *skb) 378 { 379 unsigned long flags; 380 netdev_tx_t ret; 381 382 if (unlikely(!np)) { 383 dev_kfree_skb_irq(skb); 384 ret = NET_XMIT_DROP; 385 } else { 386 local_irq_save(flags); 387 ret = __netpoll_send_skb(np, skb); 388 local_irq_restore(flags); 389 } 390 return ret; 391 } 392 EXPORT_SYMBOL(netpoll_send_skb); 393 394 int netpoll_send_udp(struct netpoll *np, const char *msg, int len) 395 { 396 int total_len, ip_len, udp_len; 397 struct sk_buff *skb; 398 struct udphdr *udph; 399 struct iphdr *iph; 400 struct ethhdr *eth; 401 static atomic_t ip_ident; 402 struct ipv6hdr *ip6h; 403 404 if (!IS_ENABLED(CONFIG_PREEMPT_RT)) 405 WARN_ON_ONCE(!irqs_disabled()); 406 407 udp_len = len + sizeof(*udph); 408 if (np->ipv6) 409 ip_len = udp_len + sizeof(*ip6h); 410 else 411 ip_len = udp_len + sizeof(*iph); 412 413 total_len = ip_len + LL_RESERVED_SPACE(np->dev); 414 415 skb = find_skb(np, total_len + np->dev->needed_tailroom, 416 total_len - len); 417 if (!skb) 418 return -ENOMEM; 419 420 skb_copy_to_linear_data(skb, msg, len); 421 skb_put(skb, len); 422 423 skb_push(skb, sizeof(*udph)); 424 skb_reset_transport_header(skb); 425 udph = udp_hdr(skb); 426 udph->source = htons(np->local_port); 427 udph->dest = htons(np->remote_port); 428 udph->len = htons(udp_len); 429 430 if (np->ipv6) { 431 udph->check = 0; 432 udph->check = csum_ipv6_magic(&np->local_ip.in6, 433 &np->remote_ip.in6, 434 udp_len, IPPROTO_UDP, 435 csum_partial(udph, udp_len, 0)); 436 if (udph->check == 0) 437 udph->check = CSUM_MANGLED_0; 438 439 skb_push(skb, sizeof(*ip6h)); 440 skb_reset_network_header(skb); 441 ip6h = ipv6_hdr(skb); 442 443 /* ip6h->version = 6; ip6h->priority = 0; */ 444 *(unsigned char *)ip6h = 0x60; 445 ip6h->flow_lbl[0] = 0; 446 ip6h->flow_lbl[1] = 0; 447 ip6h->flow_lbl[2] = 0; 448 449 ip6h->payload_len = htons(sizeof(struct udphdr) + len); 450 ip6h->nexthdr = IPPROTO_UDP; 451 ip6h->hop_limit = 32; 452 ip6h->saddr = np->local_ip.in6; 453 ip6h->daddr = np->remote_ip.in6; 454 455 eth = skb_push(skb, ETH_HLEN); 456 skb_reset_mac_header(skb); 457 skb->protocol = eth->h_proto = htons(ETH_P_IPV6); 458 } else { 459 udph->check = 0; 460 udph->check = csum_tcpudp_magic(np->local_ip.ip, 461 np->remote_ip.ip, 462 udp_len, IPPROTO_UDP, 463 csum_partial(udph, udp_len, 0)); 464 if (udph->check == 0) 465 udph->check = CSUM_MANGLED_0; 466 467 skb_push(skb, sizeof(*iph)); 468 skb_reset_network_header(skb); 469 iph = ip_hdr(skb); 470 471 /* iph->version = 4; iph->ihl = 5; */ 472 *(unsigned char *)iph = 0x45; 473 iph->tos = 0; 474 put_unaligned(htons(ip_len), &(iph->tot_len)); 475 iph->id = htons(atomic_inc_return(&ip_ident)); 476 iph->frag_off = 0; 477 iph->ttl = 64; 478 iph->protocol = IPPROTO_UDP; 479 iph->check = 0; 480 put_unaligned(np->local_ip.ip, &(iph->saddr)); 481 put_unaligned(np->remote_ip.ip, &(iph->daddr)); 482 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); 483 484 eth = skb_push(skb, ETH_HLEN); 485 skb_reset_mac_header(skb); 486 skb->protocol = eth->h_proto = htons(ETH_P_IP); 487 } 488 489 ether_addr_copy(eth->h_source, np->dev->dev_addr); 490 ether_addr_copy(eth->h_dest, np->remote_mac); 491 492 skb->dev = np->dev; 493 494 return (int)netpoll_send_skb(np, skb); 495 } 496 EXPORT_SYMBOL(netpoll_send_udp); 497 498 void netpoll_print_options(struct netpoll *np) 499 { 500 np_info(np, "local port %d\n", np->local_port); 501 if (np->ipv6) 502 np_info(np, "local IPv6 address %pI6c\n", &np->local_ip.in6); 503 else 504 np_info(np, "local IPv4 address %pI4\n", &np->local_ip.ip); 505 np_info(np, "interface '%s'\n", np->dev_name); 506 np_info(np, "remote port %d\n", np->remote_port); 507 if (np->ipv6) 508 np_info(np, "remote IPv6 address %pI6c\n", &np->remote_ip.in6); 509 else 510 np_info(np, "remote IPv4 address %pI4\n", &np->remote_ip.ip); 511 np_info(np, "remote ethernet address %pM\n", np->remote_mac); 512 } 513 EXPORT_SYMBOL(netpoll_print_options); 514 515 static int netpoll_parse_ip_addr(const char *str, union inet_addr *addr) 516 { 517 const char *end; 518 519 if (!strchr(str, ':') && 520 in4_pton(str, -1, (void *)addr, -1, &end) > 0) { 521 if (!*end) 522 return 0; 523 } 524 if (in6_pton(str, -1, addr->in6.s6_addr, -1, &end) > 0) { 525 #if IS_ENABLED(CONFIG_IPV6) 526 if (!*end) 527 return 1; 528 #else 529 return -1; 530 #endif 531 } 532 return -1; 533 } 534 535 static void skb_pool_flush(struct netpoll *np) 536 { 537 struct sk_buff_head *skb_pool; 538 539 cancel_work_sync(&np->refill_wq); 540 skb_pool = &np->skb_pool; 541 skb_queue_purge_reason(skb_pool, SKB_CONSUMED); 542 } 543 544 int netpoll_parse_options(struct netpoll *np, char *opt) 545 { 546 char *cur=opt, *delim; 547 int ipv6; 548 bool ipversion_set = false; 549 550 if (*cur != '@') { 551 if ((delim = strchr(cur, '@')) == NULL) 552 goto parse_failed; 553 *delim = 0; 554 if (kstrtou16(cur, 10, &np->local_port)) 555 goto parse_failed; 556 cur = delim; 557 } 558 cur++; 559 560 if (*cur != '/') { 561 ipversion_set = true; 562 if ((delim = strchr(cur, '/')) == NULL) 563 goto parse_failed; 564 *delim = 0; 565 ipv6 = netpoll_parse_ip_addr(cur, &np->local_ip); 566 if (ipv6 < 0) 567 goto parse_failed; 568 else 569 np->ipv6 = (bool)ipv6; 570 cur = delim; 571 } 572 cur++; 573 574 if (*cur != ',') { 575 /* parse out dev name */ 576 if ((delim = strchr(cur, ',')) == NULL) 577 goto parse_failed; 578 *delim = 0; 579 strscpy(np->dev_name, cur, sizeof(np->dev_name)); 580 cur = delim; 581 } 582 cur++; 583 584 if (*cur != '@') { 585 /* dst port */ 586 if ((delim = strchr(cur, '@')) == NULL) 587 goto parse_failed; 588 *delim = 0; 589 if (*cur == ' ' || *cur == '\t') 590 np_info(np, "warning: whitespace is not allowed\n"); 591 if (kstrtou16(cur, 10, &np->remote_port)) 592 goto parse_failed; 593 cur = delim; 594 } 595 cur++; 596 597 /* dst ip */ 598 if ((delim = strchr(cur, '/')) == NULL) 599 goto parse_failed; 600 *delim = 0; 601 ipv6 = netpoll_parse_ip_addr(cur, &np->remote_ip); 602 if (ipv6 < 0) 603 goto parse_failed; 604 else if (ipversion_set && np->ipv6 != (bool)ipv6) 605 goto parse_failed; 606 else 607 np->ipv6 = (bool)ipv6; 608 cur = delim + 1; 609 610 if (*cur != 0) { 611 /* MAC address */ 612 if (!mac_pton(cur, np->remote_mac)) 613 goto parse_failed; 614 } 615 616 netpoll_print_options(np); 617 618 return 0; 619 620 parse_failed: 621 np_info(np, "couldn't parse config at '%s'!\n", cur); 622 return -1; 623 } 624 EXPORT_SYMBOL(netpoll_parse_options); 625 626 static void refill_skbs_work_handler(struct work_struct *work) 627 { 628 struct netpoll *np = 629 container_of(work, struct netpoll, refill_wq); 630 631 refill_skbs(np); 632 } 633 634 int __netpoll_setup(struct netpoll *np, struct net_device *ndev) 635 { 636 struct netpoll_info *npinfo; 637 const struct net_device_ops *ops; 638 int err; 639 640 skb_queue_head_init(&np->skb_pool); 641 642 if (ndev->priv_flags & IFF_DISABLE_NETPOLL) { 643 np_err(np, "%s doesn't support polling, aborting\n", 644 ndev->name); 645 err = -ENOTSUPP; 646 goto out; 647 } 648 649 npinfo = rtnl_dereference(ndev->npinfo); 650 if (!npinfo) { 651 npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL); 652 if (!npinfo) { 653 err = -ENOMEM; 654 goto out; 655 } 656 657 sema_init(&npinfo->dev_lock, 1); 658 skb_queue_head_init(&npinfo->txq); 659 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process); 660 661 refcount_set(&npinfo->refcnt, 1); 662 663 ops = ndev->netdev_ops; 664 if (ops->ndo_netpoll_setup) { 665 err = ops->ndo_netpoll_setup(ndev); 666 if (err) 667 goto free_npinfo; 668 } 669 } else { 670 refcount_inc(&npinfo->refcnt); 671 } 672 673 np->dev = ndev; 674 strscpy(np->dev_name, ndev->name, IFNAMSIZ); 675 npinfo->netpoll = np; 676 677 /* fill up the skb queue */ 678 refill_skbs(np); 679 INIT_WORK(&np->refill_wq, refill_skbs_work_handler); 680 681 /* last thing to do is link it to the net device structure */ 682 rcu_assign_pointer(ndev->npinfo, npinfo); 683 684 return 0; 685 686 free_npinfo: 687 kfree(npinfo); 688 out: 689 return err; 690 } 691 EXPORT_SYMBOL_GPL(__netpoll_setup); 692 693 int netpoll_setup(struct netpoll *np) 694 { 695 struct net_device *ndev = NULL; 696 bool ip_overwritten = false; 697 struct in_device *in_dev; 698 int err; 699 700 rtnl_lock(); 701 if (np->dev_name[0]) { 702 struct net *net = current->nsproxy->net_ns; 703 ndev = __dev_get_by_name(net, np->dev_name); 704 } 705 if (!ndev) { 706 np_err(np, "%s doesn't exist, aborting\n", np->dev_name); 707 err = -ENODEV; 708 goto unlock; 709 } 710 netdev_hold(ndev, &np->dev_tracker, GFP_KERNEL); 711 712 if (netdev_master_upper_dev_get(ndev)) { 713 np_err(np, "%s is a slave device, aborting\n", np->dev_name); 714 err = -EBUSY; 715 goto put; 716 } 717 718 if (!netif_running(ndev)) { 719 unsigned long atmost; 720 721 np_info(np, "device %s not up yet, forcing it\n", np->dev_name); 722 723 err = dev_open(ndev, NULL); 724 725 if (err) { 726 np_err(np, "failed to open %s\n", ndev->name); 727 goto put; 728 } 729 730 rtnl_unlock(); 731 atmost = jiffies + carrier_timeout * HZ; 732 while (!netif_carrier_ok(ndev)) { 733 if (time_after(jiffies, atmost)) { 734 np_notice(np, "timeout waiting for carrier\n"); 735 break; 736 } 737 msleep(1); 738 } 739 740 rtnl_lock(); 741 } 742 743 if (!np->local_ip.ip) { 744 if (!np->ipv6) { 745 const struct in_ifaddr *ifa; 746 747 in_dev = __in_dev_get_rtnl(ndev); 748 if (!in_dev) 749 goto put_noaddr; 750 751 ifa = rtnl_dereference(in_dev->ifa_list); 752 if (!ifa) { 753 put_noaddr: 754 np_err(np, "no IP address for %s, aborting\n", 755 np->dev_name); 756 err = -EDESTADDRREQ; 757 goto put; 758 } 759 760 np->local_ip.ip = ifa->ifa_local; 761 ip_overwritten = true; 762 np_info(np, "local IP %pI4\n", &np->local_ip.ip); 763 } else { 764 #if IS_ENABLED(CONFIG_IPV6) 765 struct inet6_dev *idev; 766 767 err = -EDESTADDRREQ; 768 idev = __in6_dev_get(ndev); 769 if (idev) { 770 struct inet6_ifaddr *ifp; 771 772 read_lock_bh(&idev->lock); 773 list_for_each_entry(ifp, &idev->addr_list, if_list) { 774 if (!!(ipv6_addr_type(&ifp->addr) & IPV6_ADDR_LINKLOCAL) != 775 !!(ipv6_addr_type(&np->remote_ip.in6) & IPV6_ADDR_LINKLOCAL)) 776 continue; 777 np->local_ip.in6 = ifp->addr; 778 ip_overwritten = true; 779 err = 0; 780 break; 781 } 782 read_unlock_bh(&idev->lock); 783 } 784 if (err) { 785 np_err(np, "no IPv6 address for %s, aborting\n", 786 np->dev_name); 787 goto put; 788 } else 789 np_info(np, "local IPv6 %pI6c\n", &np->local_ip.in6); 790 #else 791 np_err(np, "IPv6 is not supported %s, aborting\n", 792 np->dev_name); 793 err = -EINVAL; 794 goto put; 795 #endif 796 } 797 } 798 799 err = __netpoll_setup(np, ndev); 800 if (err) 801 goto flush; 802 rtnl_unlock(); 803 return 0; 804 805 flush: 806 skb_pool_flush(np); 807 put: 808 DEBUG_NET_WARN_ON_ONCE(np->dev); 809 if (ip_overwritten) 810 memset(&np->local_ip, 0, sizeof(np->local_ip)); 811 netdev_put(ndev, &np->dev_tracker); 812 unlock: 813 rtnl_unlock(); 814 return err; 815 } 816 EXPORT_SYMBOL(netpoll_setup); 817 818 static void rcu_cleanup_netpoll_info(struct rcu_head *rcu_head) 819 { 820 struct netpoll_info *npinfo = 821 container_of(rcu_head, struct netpoll_info, rcu); 822 823 skb_queue_purge(&npinfo->txq); 824 825 /* we can't call cancel_delayed_work_sync here, as we are in softirq */ 826 cancel_delayed_work(&npinfo->tx_work); 827 828 /* clean after last, unfinished work */ 829 __skb_queue_purge(&npinfo->txq); 830 /* now cancel it again */ 831 cancel_delayed_work(&npinfo->tx_work); 832 kfree(npinfo); 833 } 834 835 void __netpoll_cleanup(struct netpoll *np) 836 { 837 struct netpoll_info *npinfo; 838 839 npinfo = rtnl_dereference(np->dev->npinfo); 840 if (!npinfo) 841 return; 842 843 if (refcount_dec_and_test(&npinfo->refcnt)) { 844 const struct net_device_ops *ops; 845 846 ops = np->dev->netdev_ops; 847 if (ops->ndo_netpoll_cleanup) 848 ops->ndo_netpoll_cleanup(np->dev); 849 850 RCU_INIT_POINTER(np->dev->npinfo, NULL); 851 call_rcu(&npinfo->rcu, rcu_cleanup_netpoll_info); 852 } else 853 RCU_INIT_POINTER(np->dev->npinfo, NULL); 854 855 skb_pool_flush(np); 856 } 857 EXPORT_SYMBOL_GPL(__netpoll_cleanup); 858 859 void __netpoll_free(struct netpoll *np) 860 { 861 ASSERT_RTNL(); 862 863 /* Wait for transmitting packets to finish before freeing. */ 864 synchronize_rcu(); 865 __netpoll_cleanup(np); 866 kfree(np); 867 } 868 EXPORT_SYMBOL_GPL(__netpoll_free); 869 870 void do_netpoll_cleanup(struct netpoll *np) 871 { 872 __netpoll_cleanup(np); 873 netdev_put(np->dev, &np->dev_tracker); 874 np->dev = NULL; 875 } 876 EXPORT_SYMBOL(do_netpoll_cleanup); 877 878 void netpoll_cleanup(struct netpoll *np) 879 { 880 rtnl_lock(); 881 if (!np->dev) 882 goto out; 883 do_netpoll_cleanup(np); 884 out: 885 rtnl_unlock(); 886 } 887 EXPORT_SYMBOL(netpoll_cleanup); 888