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 49 static struct sk_buff_head skb_pool; 50 51 #define USEC_PER_POLL 50 52 53 #define MAX_SKB_SIZE \ 54 (sizeof(struct ethhdr) + \ 55 sizeof(struct iphdr) + \ 56 sizeof(struct udphdr) + \ 57 MAX_UDP_CHUNK) 58 59 static void zap_completion_queue(void); 60 61 static unsigned int carrier_timeout = 4; 62 module_param(carrier_timeout, uint, 0644); 63 64 #define np_info(np, fmt, ...) \ 65 pr_info("%s: " fmt, np->name, ##__VA_ARGS__) 66 #define np_err(np, fmt, ...) \ 67 pr_err("%s: " fmt, np->name, ##__VA_ARGS__) 68 #define np_notice(np, fmt, ...) \ 69 pr_notice("%s: " fmt, np->name, ##__VA_ARGS__) 70 netpoll_start_xmit(struct sk_buff * skb,struct net_device * dev,struct netdev_queue * txq)71 static netdev_tx_t netpoll_start_xmit(struct sk_buff *skb, 72 struct net_device *dev, 73 struct netdev_queue *txq) 74 { 75 netdev_tx_t status = NETDEV_TX_OK; 76 netdev_features_t features; 77 78 features = netif_skb_features(skb); 79 80 if (skb_vlan_tag_present(skb) && 81 !vlan_hw_offload_capable(features, skb->vlan_proto)) { 82 skb = __vlan_hwaccel_push_inside(skb); 83 if (unlikely(!skb)) { 84 /* This is actually a packet drop, but we 85 * don't want the code that calls this 86 * function to try and operate on a NULL skb. 87 */ 88 goto out; 89 } 90 } 91 92 status = netdev_start_xmit(skb, dev, txq, false); 93 94 out: 95 return status; 96 } 97 queue_process(struct work_struct * work)98 static void queue_process(struct work_struct *work) 99 { 100 struct netpoll_info *npinfo = 101 container_of(work, struct netpoll_info, tx_work.work); 102 struct sk_buff *skb; 103 unsigned long flags; 104 105 while ((skb = skb_dequeue(&npinfo->txq))) { 106 struct net_device *dev = skb->dev; 107 struct netdev_queue *txq; 108 unsigned int q_index; 109 110 if (!netif_device_present(dev) || !netif_running(dev)) { 111 kfree_skb(skb); 112 continue; 113 } 114 115 local_irq_save(flags); 116 /* check if skb->queue_mapping is still valid */ 117 q_index = skb_get_queue_mapping(skb); 118 if (unlikely(q_index >= dev->real_num_tx_queues)) { 119 q_index = q_index % dev->real_num_tx_queues; 120 skb_set_queue_mapping(skb, q_index); 121 } 122 txq = netdev_get_tx_queue(dev, q_index); 123 HARD_TX_LOCK(dev, txq, smp_processor_id()); 124 if (netif_xmit_frozen_or_stopped(txq) || 125 !dev_xmit_complete(netpoll_start_xmit(skb, dev, txq))) { 126 skb_queue_head(&npinfo->txq, skb); 127 HARD_TX_UNLOCK(dev, txq); 128 local_irq_restore(flags); 129 130 schedule_delayed_work(&npinfo->tx_work, HZ/10); 131 return; 132 } 133 HARD_TX_UNLOCK(dev, txq); 134 local_irq_restore(flags); 135 } 136 } 137 netif_local_xmit_active(struct net_device * dev)138 static int netif_local_xmit_active(struct net_device *dev) 139 { 140 int i; 141 142 for (i = 0; i < dev->num_tx_queues; i++) { 143 struct netdev_queue *txq = netdev_get_tx_queue(dev, i); 144 145 if (READ_ONCE(txq->xmit_lock_owner) == smp_processor_id()) 146 return 1; 147 } 148 149 return 0; 150 } 151 poll_one_napi(struct napi_struct * napi)152 static void poll_one_napi(struct napi_struct *napi) 153 { 154 int work; 155 156 /* If we set this bit but see that it has already been set, 157 * that indicates that napi has been disabled and we need 158 * to abort this operation 159 */ 160 if (test_and_set_bit(NAPI_STATE_NPSVC, &napi->state)) 161 return; 162 163 /* We explicitly pass the polling call a budget of 0 to 164 * indicate that we are clearing the Tx path only. 165 */ 166 work = napi->poll(napi, 0); 167 WARN_ONCE(work, "%pS exceeded budget in poll\n", napi->poll); 168 trace_napi_poll(napi, work, 0); 169 170 clear_bit(NAPI_STATE_NPSVC, &napi->state); 171 } 172 poll_napi(struct net_device * dev)173 static void poll_napi(struct net_device *dev) 174 { 175 struct napi_struct *napi; 176 int cpu = smp_processor_id(); 177 178 list_for_each_entry_rcu(napi, &dev->napi_list, dev_list) { 179 if (cmpxchg(&napi->poll_owner, -1, cpu) == -1) { 180 poll_one_napi(napi); 181 smp_store_release(&napi->poll_owner, -1); 182 } 183 } 184 } 185 netpoll_poll_dev(struct net_device * dev)186 void netpoll_poll_dev(struct net_device *dev) 187 { 188 struct netpoll_info *ni = rcu_dereference_bh(dev->npinfo); 189 const struct net_device_ops *ops; 190 191 /* Don't do any rx activity if the dev_lock mutex is held 192 * the dev_open/close paths use this to block netpoll activity 193 * while changing device state 194 */ 195 if (!ni || down_trylock(&ni->dev_lock)) 196 return; 197 198 /* Some drivers will take the same locks in poll and xmit, 199 * we can't poll if local CPU is already in xmit. 200 */ 201 if (!netif_running(dev) || netif_local_xmit_active(dev)) { 202 up(&ni->dev_lock); 203 return; 204 } 205 206 ops = dev->netdev_ops; 207 if (ops->ndo_poll_controller) 208 ops->ndo_poll_controller(dev); 209 210 poll_napi(dev); 211 212 up(&ni->dev_lock); 213 214 zap_completion_queue(); 215 } 216 EXPORT_SYMBOL(netpoll_poll_dev); 217 netpoll_poll_disable(struct net_device * dev)218 void netpoll_poll_disable(struct net_device *dev) 219 { 220 struct netpoll_info *ni; 221 222 might_sleep(); 223 ni = rtnl_dereference(dev->npinfo); 224 if (ni) 225 down(&ni->dev_lock); 226 } 227 netpoll_poll_enable(struct net_device * dev)228 void netpoll_poll_enable(struct net_device *dev) 229 { 230 struct netpoll_info *ni; 231 232 ni = rtnl_dereference(dev->npinfo); 233 if (ni) 234 up(&ni->dev_lock); 235 } 236 refill_skbs(void)237 static void refill_skbs(void) 238 { 239 struct sk_buff *skb; 240 unsigned long flags; 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 zap_completion_queue(void)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 find_skb(struct netpoll * np,int len,int reserve)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(); 288 repeat: 289 290 skb = alloc_skb(len, GFP_ATOMIC); 291 if (!skb) 292 skb = skb_dequeue(&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 netpoll_owner_active(struct net_device * dev)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 */ __netpoll_send_skb(struct netpoll * np,struct sk_buff * skb)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 netpoll_send_skb(struct netpoll * np,struct sk_buff * skb)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 netpoll_send_udp(struct netpoll * np,const char * msg,int len)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 netpoll_print_options(struct netpoll * np)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 netpoll_parse_ip_addr(const char * str,union inet_addr * addr)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 netpoll_parse_options(struct netpoll * np,char * opt)534 int netpoll_parse_options(struct netpoll *np, char *opt) 535 { 536 char *cur=opt, *delim; 537 int ipv6; 538 bool ipversion_set = false; 539 540 if (*cur != '@') { 541 if ((delim = strchr(cur, '@')) == NULL) 542 goto parse_failed; 543 *delim = 0; 544 if (kstrtou16(cur, 10, &np->local_port)) 545 goto parse_failed; 546 cur = delim; 547 } 548 cur++; 549 550 if (*cur != '/') { 551 ipversion_set = true; 552 if ((delim = strchr(cur, '/')) == NULL) 553 goto parse_failed; 554 *delim = 0; 555 ipv6 = netpoll_parse_ip_addr(cur, &np->local_ip); 556 if (ipv6 < 0) 557 goto parse_failed; 558 else 559 np->ipv6 = (bool)ipv6; 560 cur = delim; 561 } 562 cur++; 563 564 if (*cur != ',') { 565 /* parse out dev name */ 566 if ((delim = strchr(cur, ',')) == NULL) 567 goto parse_failed; 568 *delim = 0; 569 strscpy(np->dev_name, cur, sizeof(np->dev_name)); 570 cur = delim; 571 } 572 cur++; 573 574 if (*cur != '@') { 575 /* dst port */ 576 if ((delim = strchr(cur, '@')) == NULL) 577 goto parse_failed; 578 *delim = 0; 579 if (*cur == ' ' || *cur == '\t') 580 np_info(np, "warning: whitespace is not allowed\n"); 581 if (kstrtou16(cur, 10, &np->remote_port)) 582 goto parse_failed; 583 cur = delim; 584 } 585 cur++; 586 587 /* dst ip */ 588 if ((delim = strchr(cur, '/')) == NULL) 589 goto parse_failed; 590 *delim = 0; 591 ipv6 = netpoll_parse_ip_addr(cur, &np->remote_ip); 592 if (ipv6 < 0) 593 goto parse_failed; 594 else if (ipversion_set && np->ipv6 != (bool)ipv6) 595 goto parse_failed; 596 else 597 np->ipv6 = (bool)ipv6; 598 cur = delim + 1; 599 600 if (*cur != 0) { 601 /* MAC address */ 602 if (!mac_pton(cur, np->remote_mac)) 603 goto parse_failed; 604 } 605 606 netpoll_print_options(np); 607 608 return 0; 609 610 parse_failed: 611 np_info(np, "couldn't parse config at '%s'!\n", cur); 612 return -1; 613 } 614 EXPORT_SYMBOL(netpoll_parse_options); 615 __netpoll_setup(struct netpoll * np,struct net_device * ndev)616 int __netpoll_setup(struct netpoll *np, struct net_device *ndev) 617 { 618 struct netpoll_info *npinfo; 619 const struct net_device_ops *ops; 620 int err; 621 622 if (ndev->priv_flags & IFF_DISABLE_NETPOLL) { 623 np_err(np, "%s doesn't support polling, aborting\n", 624 ndev->name); 625 err = -ENOTSUPP; 626 goto out; 627 } 628 629 if (!ndev->npinfo) { 630 npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL); 631 if (!npinfo) { 632 err = -ENOMEM; 633 goto out; 634 } 635 636 sema_init(&npinfo->dev_lock, 1); 637 skb_queue_head_init(&npinfo->txq); 638 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process); 639 640 refcount_set(&npinfo->refcnt, 1); 641 642 ops = ndev->netdev_ops; 643 if (ops->ndo_netpoll_setup) { 644 err = ops->ndo_netpoll_setup(ndev, npinfo); 645 if (err) 646 goto free_npinfo; 647 } 648 } else { 649 npinfo = rtnl_dereference(ndev->npinfo); 650 refcount_inc(&npinfo->refcnt); 651 } 652 653 np->dev = ndev; 654 strscpy(np->dev_name, ndev->name, IFNAMSIZ); 655 npinfo->netpoll = np; 656 657 /* last thing to do is link it to the net device structure */ 658 rcu_assign_pointer(ndev->npinfo, npinfo); 659 660 return 0; 661 662 free_npinfo: 663 kfree(npinfo); 664 out: 665 return err; 666 } 667 EXPORT_SYMBOL_GPL(__netpoll_setup); 668 netpoll_setup(struct netpoll * np)669 int netpoll_setup(struct netpoll *np) 670 { 671 struct net_device *ndev = NULL; 672 bool ip_overwritten = false; 673 struct in_device *in_dev; 674 int err; 675 676 rtnl_lock(); 677 if (np->dev_name[0]) { 678 struct net *net = current->nsproxy->net_ns; 679 ndev = __dev_get_by_name(net, np->dev_name); 680 } 681 if (!ndev) { 682 np_err(np, "%s doesn't exist, aborting\n", np->dev_name); 683 err = -ENODEV; 684 goto unlock; 685 } 686 netdev_hold(ndev, &np->dev_tracker, GFP_KERNEL); 687 688 if (netdev_master_upper_dev_get(ndev)) { 689 np_err(np, "%s is a slave device, aborting\n", np->dev_name); 690 err = -EBUSY; 691 goto put; 692 } 693 694 if (!netif_running(ndev)) { 695 unsigned long atmost; 696 697 np_info(np, "device %s not up yet, forcing it\n", np->dev_name); 698 699 err = dev_open(ndev, NULL); 700 701 if (err) { 702 np_err(np, "failed to open %s\n", ndev->name); 703 goto put; 704 } 705 706 rtnl_unlock(); 707 atmost = jiffies + carrier_timeout * HZ; 708 while (!netif_carrier_ok(ndev)) { 709 if (time_after(jiffies, atmost)) { 710 np_notice(np, "timeout waiting for carrier\n"); 711 break; 712 } 713 msleep(1); 714 } 715 716 rtnl_lock(); 717 } 718 719 if (!np->local_ip.ip) { 720 if (!np->ipv6) { 721 const struct in_ifaddr *ifa; 722 723 in_dev = __in_dev_get_rtnl(ndev); 724 if (!in_dev) 725 goto put_noaddr; 726 727 ifa = rtnl_dereference(in_dev->ifa_list); 728 if (!ifa) { 729 put_noaddr: 730 np_err(np, "no IP address for %s, aborting\n", 731 np->dev_name); 732 err = -EDESTADDRREQ; 733 goto put; 734 } 735 736 np->local_ip.ip = ifa->ifa_local; 737 ip_overwritten = true; 738 np_info(np, "local IP %pI4\n", &np->local_ip.ip); 739 } else { 740 #if IS_ENABLED(CONFIG_IPV6) 741 struct inet6_dev *idev; 742 743 err = -EDESTADDRREQ; 744 idev = __in6_dev_get(ndev); 745 if (idev) { 746 struct inet6_ifaddr *ifp; 747 748 read_lock_bh(&idev->lock); 749 list_for_each_entry(ifp, &idev->addr_list, if_list) { 750 if (!!(ipv6_addr_type(&ifp->addr) & IPV6_ADDR_LINKLOCAL) != 751 !!(ipv6_addr_type(&np->remote_ip.in6) & IPV6_ADDR_LINKLOCAL)) 752 continue; 753 np->local_ip.in6 = ifp->addr; 754 ip_overwritten = true; 755 err = 0; 756 break; 757 } 758 read_unlock_bh(&idev->lock); 759 } 760 if (err) { 761 np_err(np, "no IPv6 address for %s, aborting\n", 762 np->dev_name); 763 goto put; 764 } else 765 np_info(np, "local IPv6 %pI6c\n", &np->local_ip.in6); 766 #else 767 np_err(np, "IPv6 is not supported %s, aborting\n", 768 np->dev_name); 769 err = -EINVAL; 770 goto put; 771 #endif 772 } 773 } 774 775 /* fill up the skb queue */ 776 refill_skbs(); 777 778 err = __netpoll_setup(np, ndev); 779 if (err) 780 goto put; 781 rtnl_unlock(); 782 return 0; 783 784 put: 785 DEBUG_NET_WARN_ON_ONCE(np->dev); 786 if (ip_overwritten) 787 memset(&np->local_ip, 0, sizeof(np->local_ip)); 788 netdev_put(ndev, &np->dev_tracker); 789 unlock: 790 rtnl_unlock(); 791 return err; 792 } 793 EXPORT_SYMBOL(netpoll_setup); 794 netpoll_init(void)795 static int __init netpoll_init(void) 796 { 797 skb_queue_head_init(&skb_pool); 798 return 0; 799 } 800 core_initcall(netpoll_init); 801 rcu_cleanup_netpoll_info(struct rcu_head * rcu_head)802 static void rcu_cleanup_netpoll_info(struct rcu_head *rcu_head) 803 { 804 struct netpoll_info *npinfo = 805 container_of(rcu_head, struct netpoll_info, rcu); 806 807 skb_queue_purge(&npinfo->txq); 808 809 /* we can't call cancel_delayed_work_sync here, as we are in softirq */ 810 cancel_delayed_work(&npinfo->tx_work); 811 812 /* clean after last, unfinished work */ 813 __skb_queue_purge(&npinfo->txq); 814 /* now cancel it again */ 815 cancel_delayed_work(&npinfo->tx_work); 816 kfree(npinfo); 817 } 818 __netpoll_cleanup(struct netpoll * np)819 void __netpoll_cleanup(struct netpoll *np) 820 { 821 struct netpoll_info *npinfo; 822 823 npinfo = rtnl_dereference(np->dev->npinfo); 824 if (!npinfo) 825 return; 826 827 if (refcount_dec_and_test(&npinfo->refcnt)) { 828 const struct net_device_ops *ops; 829 830 ops = np->dev->netdev_ops; 831 if (ops->ndo_netpoll_cleanup) 832 ops->ndo_netpoll_cleanup(np->dev); 833 834 RCU_INIT_POINTER(np->dev->npinfo, NULL); 835 call_rcu(&npinfo->rcu, rcu_cleanup_netpoll_info); 836 } else 837 RCU_INIT_POINTER(np->dev->npinfo, NULL); 838 } 839 EXPORT_SYMBOL_GPL(__netpoll_cleanup); 840 __netpoll_free(struct netpoll * np)841 void __netpoll_free(struct netpoll *np) 842 { 843 ASSERT_RTNL(); 844 845 /* Wait for transmitting packets to finish before freeing. */ 846 synchronize_rcu(); 847 __netpoll_cleanup(np); 848 kfree(np); 849 } 850 EXPORT_SYMBOL_GPL(__netpoll_free); 851 do_netpoll_cleanup(struct netpoll * np)852 void do_netpoll_cleanup(struct netpoll *np) 853 { 854 __netpoll_cleanup(np); 855 netdev_put(np->dev, &np->dev_tracker); 856 np->dev = NULL; 857 } 858 EXPORT_SYMBOL(do_netpoll_cleanup); 859 netpoll_cleanup(struct netpoll * np)860 void netpoll_cleanup(struct netpoll *np) 861 { 862 rtnl_lock(); 863 if (!np->dev) 864 goto out; 865 do_netpoll_cleanup(np); 866 out: 867 rtnl_unlock(); 868 } 869 EXPORT_SYMBOL(netpoll_cleanup); 870