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 udph->check = 0; 436 if (np->ipv6) { 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 = csum_tcpudp_magic(np->local_ip.ip, 465 np->remote_ip.ip, 466 udp_len, IPPROTO_UDP, 467 csum_partial(udph, udp_len, 0)); 468 if (udph->check == 0) 469 udph->check = CSUM_MANGLED_0; 470 471 skb_push(skb, sizeof(*iph)); 472 skb_reset_network_header(skb); 473 iph = ip_hdr(skb); 474 475 /* iph->version = 4; iph->ihl = 5; */ 476 *(unsigned char *)iph = 0x45; 477 iph->tos = 0; 478 put_unaligned(htons(ip_len), &(iph->tot_len)); 479 iph->id = htons(atomic_inc_return(&ip_ident)); 480 iph->frag_off = 0; 481 iph->ttl = 64; 482 iph->protocol = IPPROTO_UDP; 483 iph->check = 0; 484 put_unaligned(np->local_ip.ip, &(iph->saddr)); 485 put_unaligned(np->remote_ip.ip, &(iph->daddr)); 486 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); 487 488 eth = skb_push(skb, ETH_HLEN); 489 skb_reset_mac_header(skb); 490 skb->protocol = eth->h_proto = htons(ETH_P_IP); 491 } 492 493 ether_addr_copy(eth->h_source, np->dev->dev_addr); 494 ether_addr_copy(eth->h_dest, np->remote_mac); 495 496 skb->dev = np->dev; 497 498 return (int)netpoll_send_skb(np, skb); 499 } 500 EXPORT_SYMBOL(netpoll_send_udp); 501 502 void netpoll_print_options(struct netpoll *np) 503 { 504 np_info(np, "local port %d\n", np->local_port); 505 if (np->ipv6) 506 np_info(np, "local IPv6 address %pI6c\n", &np->local_ip.in6); 507 else 508 np_info(np, "local IPv4 address %pI4\n", &np->local_ip.ip); 509 np_info(np, "interface name '%s'\n", np->dev_name); 510 np_info(np, "local ethernet address '%pM'\n", np->dev_mac); 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 or dev_mac */ 581 if ((delim = strchr(cur, ',')) == NULL) 582 goto parse_failed; 583 *delim = 0; 584 585 np->dev_name[0] = '\0'; 586 eth_broadcast_addr(np->dev_mac); 587 if (!strchr(cur, ':')) 588 strscpy(np->dev_name, cur, sizeof(np->dev_name)); 589 else if (!mac_pton(cur, np->dev_mac)) 590 goto parse_failed; 591 592 cur = delim; 593 } 594 cur++; 595 596 if (*cur != '@') { 597 /* dst port */ 598 if ((delim = strchr(cur, '@')) == NULL) 599 goto parse_failed; 600 *delim = 0; 601 if (*cur == ' ' || *cur == '\t') 602 np_info(np, "warning: whitespace is not allowed\n"); 603 if (kstrtou16(cur, 10, &np->remote_port)) 604 goto parse_failed; 605 cur = delim; 606 } 607 cur++; 608 609 /* dst ip */ 610 if ((delim = strchr(cur, '/')) == NULL) 611 goto parse_failed; 612 *delim = 0; 613 ipv6 = netpoll_parse_ip_addr(cur, &np->remote_ip); 614 if (ipv6 < 0) 615 goto parse_failed; 616 else if (ipversion_set && np->ipv6 != (bool)ipv6) 617 goto parse_failed; 618 else 619 np->ipv6 = (bool)ipv6; 620 cur = delim + 1; 621 622 if (*cur != 0) { 623 /* MAC address */ 624 if (!mac_pton(cur, np->remote_mac)) 625 goto parse_failed; 626 } 627 628 netpoll_print_options(np); 629 630 return 0; 631 632 parse_failed: 633 np_info(np, "couldn't parse config at '%s'!\n", cur); 634 return -1; 635 } 636 EXPORT_SYMBOL(netpoll_parse_options); 637 638 static void refill_skbs_work_handler(struct work_struct *work) 639 { 640 struct netpoll *np = 641 container_of(work, struct netpoll, refill_wq); 642 643 refill_skbs(np); 644 } 645 646 int __netpoll_setup(struct netpoll *np, struct net_device *ndev) 647 { 648 struct netpoll_info *npinfo; 649 const struct net_device_ops *ops; 650 int err; 651 652 skb_queue_head_init(&np->skb_pool); 653 654 if (ndev->priv_flags & IFF_DISABLE_NETPOLL) { 655 np_err(np, "%s doesn't support polling, aborting\n", 656 ndev->name); 657 err = -ENOTSUPP; 658 goto out; 659 } 660 661 npinfo = rtnl_dereference(ndev->npinfo); 662 if (!npinfo) { 663 npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL); 664 if (!npinfo) { 665 err = -ENOMEM; 666 goto out; 667 } 668 669 sema_init(&npinfo->dev_lock, 1); 670 skb_queue_head_init(&npinfo->txq); 671 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process); 672 673 refcount_set(&npinfo->refcnt, 1); 674 675 ops = ndev->netdev_ops; 676 if (ops->ndo_netpoll_setup) { 677 err = ops->ndo_netpoll_setup(ndev); 678 if (err) 679 goto free_npinfo; 680 } 681 } else { 682 refcount_inc(&npinfo->refcnt); 683 } 684 685 np->dev = ndev; 686 strscpy(np->dev_name, ndev->name, IFNAMSIZ); 687 npinfo->netpoll = np; 688 689 /* fill up the skb queue */ 690 refill_skbs(np); 691 INIT_WORK(&np->refill_wq, refill_skbs_work_handler); 692 693 /* last thing to do is link it to the net device structure */ 694 rcu_assign_pointer(ndev->npinfo, npinfo); 695 696 return 0; 697 698 free_npinfo: 699 kfree(npinfo); 700 out: 701 return err; 702 } 703 EXPORT_SYMBOL_GPL(__netpoll_setup); 704 705 /* 706 * Returns a pointer to a string representation of the identifier used 707 * to select the egress interface for the given netpoll instance. buf 708 * must be a buffer of length at least MAC_ADDR_STR_LEN + 1. 709 */ 710 static char *egress_dev(struct netpoll *np, char *buf) 711 { 712 if (np->dev_name[0]) 713 return np->dev_name; 714 715 snprintf(buf, MAC_ADDR_STR_LEN, "%pM", np->dev_mac); 716 return buf; 717 } 718 719 int netpoll_setup(struct netpoll *np) 720 { 721 struct net *net = current->nsproxy->net_ns; 722 char buf[MAC_ADDR_STR_LEN + 1]; 723 struct net_device *ndev = NULL; 724 bool ip_overwritten = false; 725 struct in_device *in_dev; 726 int err; 727 728 rtnl_lock(); 729 if (np->dev_name[0]) 730 ndev = __dev_get_by_name(net, np->dev_name); 731 else if (is_valid_ether_addr(np->dev_mac)) 732 ndev = dev_getbyhwaddr(net, ARPHRD_ETHER, np->dev_mac); 733 734 if (!ndev) { 735 np_err(np, "%s doesn't exist, aborting\n", egress_dev(np, buf)); 736 err = -ENODEV; 737 goto unlock; 738 } 739 netdev_hold(ndev, &np->dev_tracker, GFP_KERNEL); 740 741 if (netdev_master_upper_dev_get(ndev)) { 742 np_err(np, "%s is a slave device, aborting\n", 743 egress_dev(np, buf)); 744 err = -EBUSY; 745 goto put; 746 } 747 748 if (!netif_running(ndev)) { 749 unsigned long atmost; 750 751 np_info(np, "device %s not up yet, forcing it\n", 752 egress_dev(np, buf)); 753 754 err = dev_open(ndev, NULL); 755 756 if (err) { 757 np_err(np, "failed to open %s\n", ndev->name); 758 goto put; 759 } 760 761 rtnl_unlock(); 762 atmost = jiffies + carrier_timeout * HZ; 763 while (!netif_carrier_ok(ndev)) { 764 if (time_after(jiffies, atmost)) { 765 np_notice(np, "timeout waiting for carrier\n"); 766 break; 767 } 768 msleep(1); 769 } 770 771 rtnl_lock(); 772 } 773 774 if (!np->local_ip.ip) { 775 if (!np->ipv6) { 776 const struct in_ifaddr *ifa; 777 778 in_dev = __in_dev_get_rtnl(ndev); 779 if (!in_dev) 780 goto put_noaddr; 781 782 ifa = rtnl_dereference(in_dev->ifa_list); 783 if (!ifa) { 784 put_noaddr: 785 np_err(np, "no IP address for %s, aborting\n", 786 egress_dev(np, buf)); 787 err = -EDESTADDRREQ; 788 goto put; 789 } 790 791 np->local_ip.ip = ifa->ifa_local; 792 ip_overwritten = true; 793 np_info(np, "local IP %pI4\n", &np->local_ip.ip); 794 } else { 795 #if IS_ENABLED(CONFIG_IPV6) 796 struct inet6_dev *idev; 797 798 err = -EDESTADDRREQ; 799 idev = __in6_dev_get(ndev); 800 if (idev) { 801 struct inet6_ifaddr *ifp; 802 803 read_lock_bh(&idev->lock); 804 list_for_each_entry(ifp, &idev->addr_list, if_list) { 805 if (!!(ipv6_addr_type(&ifp->addr) & IPV6_ADDR_LINKLOCAL) != 806 !!(ipv6_addr_type(&np->remote_ip.in6) & IPV6_ADDR_LINKLOCAL)) 807 continue; 808 np->local_ip.in6 = ifp->addr; 809 ip_overwritten = true; 810 err = 0; 811 break; 812 } 813 read_unlock_bh(&idev->lock); 814 } 815 if (err) { 816 np_err(np, "no IPv6 address for %s, aborting\n", 817 egress_dev(np, buf)); 818 goto put; 819 } else 820 np_info(np, "local IPv6 %pI6c\n", &np->local_ip.in6); 821 #else 822 np_err(np, "IPv6 is not supported %s, aborting\n", 823 egress_dev(np, buf)); 824 err = -EINVAL; 825 goto put; 826 #endif 827 } 828 } 829 830 err = __netpoll_setup(np, ndev); 831 if (err) 832 goto flush; 833 rtnl_unlock(); 834 return 0; 835 836 flush: 837 skb_pool_flush(np); 838 put: 839 DEBUG_NET_WARN_ON_ONCE(np->dev); 840 if (ip_overwritten) 841 memset(&np->local_ip, 0, sizeof(np->local_ip)); 842 netdev_put(ndev, &np->dev_tracker); 843 unlock: 844 rtnl_unlock(); 845 return err; 846 } 847 EXPORT_SYMBOL(netpoll_setup); 848 849 static void rcu_cleanup_netpoll_info(struct rcu_head *rcu_head) 850 { 851 struct netpoll_info *npinfo = 852 container_of(rcu_head, struct netpoll_info, rcu); 853 854 skb_queue_purge(&npinfo->txq); 855 856 /* we can't call cancel_delayed_work_sync here, as we are in softirq */ 857 cancel_delayed_work(&npinfo->tx_work); 858 859 /* clean after last, unfinished work */ 860 __skb_queue_purge(&npinfo->txq); 861 /* now cancel it again */ 862 cancel_delayed_work(&npinfo->tx_work); 863 kfree(npinfo); 864 } 865 866 void __netpoll_cleanup(struct netpoll *np) 867 { 868 struct netpoll_info *npinfo; 869 870 npinfo = rtnl_dereference(np->dev->npinfo); 871 if (!npinfo) 872 return; 873 874 if (refcount_dec_and_test(&npinfo->refcnt)) { 875 const struct net_device_ops *ops; 876 877 ops = np->dev->netdev_ops; 878 if (ops->ndo_netpoll_cleanup) 879 ops->ndo_netpoll_cleanup(np->dev); 880 881 RCU_INIT_POINTER(np->dev->npinfo, NULL); 882 call_rcu(&npinfo->rcu, rcu_cleanup_netpoll_info); 883 } else 884 RCU_INIT_POINTER(np->dev->npinfo, NULL); 885 886 skb_pool_flush(np); 887 } 888 EXPORT_SYMBOL_GPL(__netpoll_cleanup); 889 890 void __netpoll_free(struct netpoll *np) 891 { 892 ASSERT_RTNL(); 893 894 /* Wait for transmitting packets to finish before freeing. */ 895 synchronize_rcu(); 896 __netpoll_cleanup(np); 897 kfree(np); 898 } 899 EXPORT_SYMBOL_GPL(__netpoll_free); 900 901 void do_netpoll_cleanup(struct netpoll *np) 902 { 903 __netpoll_cleanup(np); 904 netdev_put(np->dev, &np->dev_tracker); 905 np->dev = NULL; 906 } 907 EXPORT_SYMBOL(do_netpoll_cleanup); 908 909 void netpoll_cleanup(struct netpoll *np) 910 { 911 rtnl_lock(); 912 if (!np->dev) 913 goto out; 914 do_netpoll_cleanup(np); 915 out: 916 rtnl_unlock(); 917 } 918 EXPORT_SYMBOL(netpoll_cleanup); 919