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 name '%s'\n", np->dev_name); 511 np_info(np, "local ethernet address '%pM'\n", np->dev_mac); 512 np_info(np, "remote port %d\n", np->remote_port); 513 if (np->ipv6) 514 np_info(np, "remote IPv6 address %pI6c\n", &np->remote_ip.in6); 515 else 516 np_info(np, "remote IPv4 address %pI4\n", &np->remote_ip.ip); 517 np_info(np, "remote ethernet address %pM\n", np->remote_mac); 518 } 519 EXPORT_SYMBOL(netpoll_print_options); 520 521 static int netpoll_parse_ip_addr(const char *str, union inet_addr *addr) 522 { 523 const char *end; 524 525 if (!strchr(str, ':') && 526 in4_pton(str, -1, (void *)addr, -1, &end) > 0) { 527 if (!*end) 528 return 0; 529 } 530 if (in6_pton(str, -1, addr->in6.s6_addr, -1, &end) > 0) { 531 #if IS_ENABLED(CONFIG_IPV6) 532 if (!*end) 533 return 1; 534 #else 535 return -1; 536 #endif 537 } 538 return -1; 539 } 540 541 static void skb_pool_flush(struct netpoll *np) 542 { 543 struct sk_buff_head *skb_pool; 544 545 cancel_work_sync(&np->refill_wq); 546 skb_pool = &np->skb_pool; 547 skb_queue_purge_reason(skb_pool, SKB_CONSUMED); 548 } 549 550 int netpoll_parse_options(struct netpoll *np, char *opt) 551 { 552 char *cur=opt, *delim; 553 int ipv6; 554 bool ipversion_set = false; 555 556 if (*cur != '@') { 557 if ((delim = strchr(cur, '@')) == NULL) 558 goto parse_failed; 559 *delim = 0; 560 if (kstrtou16(cur, 10, &np->local_port)) 561 goto parse_failed; 562 cur = delim; 563 } 564 cur++; 565 566 if (*cur != '/') { 567 ipversion_set = true; 568 if ((delim = strchr(cur, '/')) == NULL) 569 goto parse_failed; 570 *delim = 0; 571 ipv6 = netpoll_parse_ip_addr(cur, &np->local_ip); 572 if (ipv6 < 0) 573 goto parse_failed; 574 else 575 np->ipv6 = (bool)ipv6; 576 cur = delim; 577 } 578 cur++; 579 580 if (*cur != ',') { 581 /* parse out dev_name or dev_mac */ 582 if ((delim = strchr(cur, ',')) == NULL) 583 goto parse_failed; 584 *delim = 0; 585 586 np->dev_name[0] = '\0'; 587 eth_broadcast_addr(np->dev_mac); 588 if (!strchr(cur, ':')) 589 strscpy(np->dev_name, cur, sizeof(np->dev_name)); 590 else if (!mac_pton(cur, np->dev_mac)) 591 goto parse_failed; 592 593 cur = delim; 594 } 595 cur++; 596 597 if (*cur != '@') { 598 /* dst port */ 599 if ((delim = strchr(cur, '@')) == NULL) 600 goto parse_failed; 601 *delim = 0; 602 if (*cur == ' ' || *cur == '\t') 603 np_info(np, "warning: whitespace is not allowed\n"); 604 if (kstrtou16(cur, 10, &np->remote_port)) 605 goto parse_failed; 606 cur = delim; 607 } 608 cur++; 609 610 /* dst ip */ 611 if ((delim = strchr(cur, '/')) == NULL) 612 goto parse_failed; 613 *delim = 0; 614 ipv6 = netpoll_parse_ip_addr(cur, &np->remote_ip); 615 if (ipv6 < 0) 616 goto parse_failed; 617 else if (ipversion_set && np->ipv6 != (bool)ipv6) 618 goto parse_failed; 619 else 620 np->ipv6 = (bool)ipv6; 621 cur = delim + 1; 622 623 if (*cur != 0) { 624 /* MAC address */ 625 if (!mac_pton(cur, np->remote_mac)) 626 goto parse_failed; 627 } 628 629 netpoll_print_options(np); 630 631 return 0; 632 633 parse_failed: 634 np_info(np, "couldn't parse config at '%s'!\n", cur); 635 return -1; 636 } 637 EXPORT_SYMBOL(netpoll_parse_options); 638 639 static void refill_skbs_work_handler(struct work_struct *work) 640 { 641 struct netpoll *np = 642 container_of(work, struct netpoll, refill_wq); 643 644 refill_skbs(np); 645 } 646 647 int __netpoll_setup(struct netpoll *np, struct net_device *ndev) 648 { 649 struct netpoll_info *npinfo; 650 const struct net_device_ops *ops; 651 int err; 652 653 skb_queue_head_init(&np->skb_pool); 654 655 if (ndev->priv_flags & IFF_DISABLE_NETPOLL) { 656 np_err(np, "%s doesn't support polling, aborting\n", 657 ndev->name); 658 err = -ENOTSUPP; 659 goto out; 660 } 661 662 npinfo = rtnl_dereference(ndev->npinfo); 663 if (!npinfo) { 664 npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL); 665 if (!npinfo) { 666 err = -ENOMEM; 667 goto out; 668 } 669 670 sema_init(&npinfo->dev_lock, 1); 671 skb_queue_head_init(&npinfo->txq); 672 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process); 673 674 refcount_set(&npinfo->refcnt, 1); 675 676 ops = ndev->netdev_ops; 677 if (ops->ndo_netpoll_setup) { 678 err = ops->ndo_netpoll_setup(ndev); 679 if (err) 680 goto free_npinfo; 681 } 682 } else { 683 refcount_inc(&npinfo->refcnt); 684 } 685 686 np->dev = ndev; 687 strscpy(np->dev_name, ndev->name, IFNAMSIZ); 688 npinfo->netpoll = np; 689 690 /* fill up the skb queue */ 691 refill_skbs(np); 692 INIT_WORK(&np->refill_wq, refill_skbs_work_handler); 693 694 /* last thing to do is link it to the net device structure */ 695 rcu_assign_pointer(ndev->npinfo, npinfo); 696 697 return 0; 698 699 free_npinfo: 700 kfree(npinfo); 701 out: 702 return err; 703 } 704 EXPORT_SYMBOL_GPL(__netpoll_setup); 705 706 /* 707 * Returns a pointer to a string representation of the identifier used 708 * to select the egress interface for the given netpoll instance. buf 709 * must be a buffer of length at least MAC_ADDR_STR_LEN + 1. 710 */ 711 static char *egress_dev(struct netpoll *np, char *buf) 712 { 713 if (np->dev_name[0]) 714 return np->dev_name; 715 716 snprintf(buf, MAC_ADDR_STR_LEN, "%pM", np->dev_mac); 717 return buf; 718 } 719 720 int netpoll_setup(struct netpoll *np) 721 { 722 struct net *net = current->nsproxy->net_ns; 723 char buf[MAC_ADDR_STR_LEN + 1]; 724 struct net_device *ndev = NULL; 725 bool ip_overwritten = false; 726 struct in_device *in_dev; 727 int err; 728 729 rtnl_lock(); 730 if (np->dev_name[0]) 731 ndev = __dev_get_by_name(net, np->dev_name); 732 else if (is_valid_ether_addr(np->dev_mac)) 733 ndev = dev_getbyhwaddr(net, ARPHRD_ETHER, np->dev_mac); 734 735 if (!ndev) { 736 np_err(np, "%s doesn't exist, aborting\n", egress_dev(np, buf)); 737 err = -ENODEV; 738 goto unlock; 739 } 740 netdev_hold(ndev, &np->dev_tracker, GFP_KERNEL); 741 742 if (netdev_master_upper_dev_get(ndev)) { 743 np_err(np, "%s is a slave device, aborting\n", 744 egress_dev(np, buf)); 745 err = -EBUSY; 746 goto put; 747 } 748 749 if (!netif_running(ndev)) { 750 unsigned long atmost; 751 752 np_info(np, "device %s not up yet, forcing it\n", 753 egress_dev(np, buf)); 754 755 err = dev_open(ndev, NULL); 756 757 if (err) { 758 np_err(np, "failed to open %s\n", ndev->name); 759 goto put; 760 } 761 762 rtnl_unlock(); 763 atmost = jiffies + carrier_timeout * HZ; 764 while (!netif_carrier_ok(ndev)) { 765 if (time_after(jiffies, atmost)) { 766 np_notice(np, "timeout waiting for carrier\n"); 767 break; 768 } 769 msleep(1); 770 } 771 772 rtnl_lock(); 773 } 774 775 if (!np->local_ip.ip) { 776 if (!np->ipv6) { 777 const struct in_ifaddr *ifa; 778 779 in_dev = __in_dev_get_rtnl(ndev); 780 if (!in_dev) 781 goto put_noaddr; 782 783 ifa = rtnl_dereference(in_dev->ifa_list); 784 if (!ifa) { 785 put_noaddr: 786 np_err(np, "no IP address for %s, aborting\n", 787 egress_dev(np, buf)); 788 err = -EDESTADDRREQ; 789 goto put; 790 } 791 792 np->local_ip.ip = ifa->ifa_local; 793 ip_overwritten = true; 794 np_info(np, "local IP %pI4\n", &np->local_ip.ip); 795 } else { 796 #if IS_ENABLED(CONFIG_IPV6) 797 struct inet6_dev *idev; 798 799 err = -EDESTADDRREQ; 800 idev = __in6_dev_get(ndev); 801 if (idev) { 802 struct inet6_ifaddr *ifp; 803 804 read_lock_bh(&idev->lock); 805 list_for_each_entry(ifp, &idev->addr_list, if_list) { 806 if (!!(ipv6_addr_type(&ifp->addr) & IPV6_ADDR_LINKLOCAL) != 807 !!(ipv6_addr_type(&np->remote_ip.in6) & IPV6_ADDR_LINKLOCAL)) 808 continue; 809 np->local_ip.in6 = ifp->addr; 810 ip_overwritten = true; 811 err = 0; 812 break; 813 } 814 read_unlock_bh(&idev->lock); 815 } 816 if (err) { 817 np_err(np, "no IPv6 address for %s, aborting\n", 818 egress_dev(np, buf)); 819 goto put; 820 } else 821 np_info(np, "local IPv6 %pI6c\n", &np->local_ip.in6); 822 #else 823 np_err(np, "IPv6 is not supported %s, aborting\n", 824 egress_dev(np, buf)); 825 err = -EINVAL; 826 goto put; 827 #endif 828 } 829 } 830 831 err = __netpoll_setup(np, ndev); 832 if (err) 833 goto flush; 834 rtnl_unlock(); 835 return 0; 836 837 flush: 838 skb_pool_flush(np); 839 put: 840 DEBUG_NET_WARN_ON_ONCE(np->dev); 841 if (ip_overwritten) 842 memset(&np->local_ip, 0, sizeof(np->local_ip)); 843 netdev_put(ndev, &np->dev_tracker); 844 unlock: 845 rtnl_unlock(); 846 return err; 847 } 848 EXPORT_SYMBOL(netpoll_setup); 849 850 static void rcu_cleanup_netpoll_info(struct rcu_head *rcu_head) 851 { 852 struct netpoll_info *npinfo = 853 container_of(rcu_head, struct netpoll_info, rcu); 854 855 skb_queue_purge(&npinfo->txq); 856 857 /* we can't call cancel_delayed_work_sync here, as we are in softirq */ 858 cancel_delayed_work(&npinfo->tx_work); 859 860 /* clean after last, unfinished work */ 861 __skb_queue_purge(&npinfo->txq); 862 /* now cancel it again */ 863 cancel_delayed_work(&npinfo->tx_work); 864 kfree(npinfo); 865 } 866 867 void __netpoll_cleanup(struct netpoll *np) 868 { 869 struct netpoll_info *npinfo; 870 871 npinfo = rtnl_dereference(np->dev->npinfo); 872 if (!npinfo) 873 return; 874 875 if (refcount_dec_and_test(&npinfo->refcnt)) { 876 const struct net_device_ops *ops; 877 878 ops = np->dev->netdev_ops; 879 if (ops->ndo_netpoll_cleanup) 880 ops->ndo_netpoll_cleanup(np->dev); 881 882 RCU_INIT_POINTER(np->dev->npinfo, NULL); 883 call_rcu(&npinfo->rcu, rcu_cleanup_netpoll_info); 884 } else 885 RCU_INIT_POINTER(np->dev->npinfo, NULL); 886 887 skb_pool_flush(np); 888 } 889 EXPORT_SYMBOL_GPL(__netpoll_cleanup); 890 891 void __netpoll_free(struct netpoll *np) 892 { 893 ASSERT_RTNL(); 894 895 /* Wait for transmitting packets to finish before freeing. */ 896 synchronize_rcu(); 897 __netpoll_cleanup(np); 898 kfree(np); 899 } 900 EXPORT_SYMBOL_GPL(__netpoll_free); 901 902 void do_netpoll_cleanup(struct netpoll *np) 903 { 904 __netpoll_cleanup(np); 905 netdev_put(np->dev, &np->dev_tracker); 906 np->dev = NULL; 907 } 908 EXPORT_SYMBOL(do_netpoll_cleanup); 909 910 void netpoll_cleanup(struct netpoll *np) 911 { 912 rtnl_lock(); 913 if (!np->dev) 914 goto out; 915 do_netpoll_cleanup(np); 916 out: 917 rtnl_unlock(); 918 } 919 EXPORT_SYMBOL(netpoll_cleanup); 920