1 /* 2 * Common framework for low-level network console, dump, and debugger code 3 * 4 * Sep 8 2003 Matt Mackall <mpm@selenic.com> 5 * 6 * based on the netconsole code from: 7 * 8 * Copyright (C) 2001 Ingo Molnar <mingo@redhat.com> 9 * Copyright (C) 2002 Red Hat, Inc. 10 */ 11 12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 13 14 #include <linux/moduleparam.h> 15 #include <linux/kernel.h> 16 #include <linux/netdevice.h> 17 #include <linux/etherdevice.h> 18 #include <linux/string.h> 19 #include <linux/if_arp.h> 20 #include <linux/inetdevice.h> 21 #include <linux/inet.h> 22 #include <linux/interrupt.h> 23 #include <linux/netpoll.h> 24 #include <linux/sched.h> 25 #include <linux/delay.h> 26 #include <linux/rcupdate.h> 27 #include <linux/workqueue.h> 28 #include <linux/slab.h> 29 #include <linux/export.h> 30 #include <linux/if_vlan.h> 31 #include <net/tcp.h> 32 #include <net/udp.h> 33 #include <net/addrconf.h> 34 #include <net/ndisc.h> 35 #include <net/ip6_checksum.h> 36 #include <asm/unaligned.h> 37 #include <trace/events/napi.h> 38 39 /* 40 * We maintain a small pool of fully-sized skbs, to make sure the 41 * message gets out even in extreme OOM situations. 42 */ 43 44 #define MAX_UDP_CHUNK 1460 45 #define MAX_SKBS 32 46 47 static struct sk_buff_head skb_pool; 48 49 static atomic_t trapped; 50 51 DEFINE_STATIC_SRCU(netpoll_srcu); 52 53 #define USEC_PER_POLL 50 54 #define NETPOLL_RX_ENABLED 1 55 #define NETPOLL_RX_DROP 2 56 57 #define MAX_SKB_SIZE \ 58 (sizeof(struct ethhdr) + \ 59 sizeof(struct iphdr) + \ 60 sizeof(struct udphdr) + \ 61 MAX_UDP_CHUNK) 62 63 static void zap_completion_queue(void); 64 static void netpoll_neigh_reply(struct sk_buff *skb, struct netpoll_info *npinfo); 65 static void netpoll_async_cleanup(struct work_struct *work); 66 67 static unsigned int carrier_timeout = 4; 68 module_param(carrier_timeout, uint, 0644); 69 70 #define np_info(np, fmt, ...) \ 71 pr_info("%s: " fmt, np->name, ##__VA_ARGS__) 72 #define np_err(np, fmt, ...) \ 73 pr_err("%s: " fmt, np->name, ##__VA_ARGS__) 74 #define np_notice(np, fmt, ...) \ 75 pr_notice("%s: " fmt, np->name, ##__VA_ARGS__) 76 77 static void queue_process(struct work_struct *work) 78 { 79 struct netpoll_info *npinfo = 80 container_of(work, struct netpoll_info, tx_work.work); 81 struct sk_buff *skb; 82 unsigned long flags; 83 84 while ((skb = skb_dequeue(&npinfo->txq))) { 85 struct net_device *dev = skb->dev; 86 const struct net_device_ops *ops = dev->netdev_ops; 87 struct netdev_queue *txq; 88 89 if (!netif_device_present(dev) || !netif_running(dev)) { 90 __kfree_skb(skb); 91 continue; 92 } 93 94 txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb)); 95 96 local_irq_save(flags); 97 __netif_tx_lock(txq, smp_processor_id()); 98 if (netif_xmit_frozen_or_stopped(txq) || 99 ops->ndo_start_xmit(skb, dev) != NETDEV_TX_OK) { 100 skb_queue_head(&npinfo->txq, skb); 101 __netif_tx_unlock(txq); 102 local_irq_restore(flags); 103 104 schedule_delayed_work(&npinfo->tx_work, HZ/10); 105 return; 106 } 107 __netif_tx_unlock(txq); 108 local_irq_restore(flags); 109 } 110 } 111 112 static __sum16 checksum_udp(struct sk_buff *skb, struct udphdr *uh, 113 unsigned short ulen, __be32 saddr, __be32 daddr) 114 { 115 __wsum psum; 116 117 if (uh->check == 0 || skb_csum_unnecessary(skb)) 118 return 0; 119 120 psum = csum_tcpudp_nofold(saddr, daddr, ulen, IPPROTO_UDP, 0); 121 122 if (skb->ip_summed == CHECKSUM_COMPLETE && 123 !csum_fold(csum_add(psum, skb->csum))) 124 return 0; 125 126 skb->csum = psum; 127 128 return __skb_checksum_complete(skb); 129 } 130 131 /* 132 * Check whether delayed processing was scheduled for our NIC. If so, 133 * we attempt to grab the poll lock and use ->poll() to pump the card. 134 * If this fails, either we've recursed in ->poll() or it's already 135 * running on another CPU. 136 * 137 * Note: we don't mask interrupts with this lock because we're using 138 * trylock here and interrupts are already disabled in the softirq 139 * case. Further, we test the poll_owner to avoid recursion on UP 140 * systems where the lock doesn't exist. 141 * 142 * In cases where there is bi-directional communications, reading only 143 * one message at a time can lead to packets being dropped by the 144 * network adapter, forcing superfluous retries and possibly timeouts. 145 * Thus, we set our budget to greater than 1. 146 */ 147 static int poll_one_napi(struct netpoll_info *npinfo, 148 struct napi_struct *napi, int budget) 149 { 150 int work; 151 152 /* net_rx_action's ->poll() invocations and our's are 153 * synchronized by this test which is only made while 154 * holding the napi->poll_lock. 155 */ 156 if (!test_bit(NAPI_STATE_SCHED, &napi->state)) 157 return budget; 158 159 npinfo->rx_flags |= NETPOLL_RX_DROP; 160 atomic_inc(&trapped); 161 set_bit(NAPI_STATE_NPSVC, &napi->state); 162 163 work = napi->poll(napi, budget); 164 trace_napi_poll(napi); 165 166 clear_bit(NAPI_STATE_NPSVC, &napi->state); 167 atomic_dec(&trapped); 168 npinfo->rx_flags &= ~NETPOLL_RX_DROP; 169 170 return budget - work; 171 } 172 173 static void poll_napi(struct net_device *dev) 174 { 175 struct napi_struct *napi; 176 int budget = 16; 177 178 list_for_each_entry(napi, &dev->napi_list, dev_list) { 179 if (napi->poll_owner != smp_processor_id() && 180 spin_trylock(&napi->poll_lock)) { 181 budget = poll_one_napi(rcu_dereference_bh(dev->npinfo), 182 napi, budget); 183 spin_unlock(&napi->poll_lock); 184 185 if (!budget) 186 break; 187 } 188 } 189 } 190 191 static void service_neigh_queue(struct netpoll_info *npi) 192 { 193 if (npi) { 194 struct sk_buff *skb; 195 196 while ((skb = skb_dequeue(&npi->neigh_tx))) 197 netpoll_neigh_reply(skb, npi); 198 } 199 } 200 201 static void netpoll_poll_dev(struct net_device *dev) 202 { 203 const struct net_device_ops *ops; 204 struct netpoll_info *ni = rcu_dereference_bh(dev->npinfo); 205 206 /* Don't do any rx activity if the dev_lock mutex is held 207 * the dev_open/close paths use this to block netpoll activity 208 * while changing device state 209 */ 210 if (down_trylock(&ni->dev_lock)) 211 return; 212 213 if (!netif_running(dev)) { 214 up(&ni->dev_lock); 215 return; 216 } 217 218 ops = dev->netdev_ops; 219 if (!ops->ndo_poll_controller) { 220 up(&ni->dev_lock); 221 return; 222 } 223 224 /* Process pending work on NIC */ 225 ops->ndo_poll_controller(dev); 226 227 poll_napi(dev); 228 229 up(&ni->dev_lock); 230 231 if (dev->flags & IFF_SLAVE) { 232 if (ni) { 233 struct net_device *bond_dev; 234 struct sk_buff *skb; 235 struct netpoll_info *bond_ni; 236 237 bond_dev = netdev_master_upper_dev_get_rcu(dev); 238 bond_ni = rcu_dereference_bh(bond_dev->npinfo); 239 while ((skb = skb_dequeue(&ni->neigh_tx))) { 240 skb->dev = bond_dev; 241 skb_queue_tail(&bond_ni->neigh_tx, skb); 242 } 243 } 244 } 245 246 service_neigh_queue(ni); 247 248 zap_completion_queue(); 249 } 250 251 void netpoll_rx_disable(struct net_device *dev) 252 { 253 struct netpoll_info *ni; 254 int idx; 255 might_sleep(); 256 idx = srcu_read_lock(&netpoll_srcu); 257 ni = srcu_dereference(dev->npinfo, &netpoll_srcu); 258 if (ni) 259 down(&ni->dev_lock); 260 srcu_read_unlock(&netpoll_srcu, idx); 261 } 262 EXPORT_SYMBOL(netpoll_rx_disable); 263 264 void netpoll_rx_enable(struct net_device *dev) 265 { 266 struct netpoll_info *ni; 267 rcu_read_lock(); 268 ni = rcu_dereference(dev->npinfo); 269 if (ni) 270 up(&ni->dev_lock); 271 rcu_read_unlock(); 272 } 273 EXPORT_SYMBOL(netpoll_rx_enable); 274 275 static void refill_skbs(void) 276 { 277 struct sk_buff *skb; 278 unsigned long flags; 279 280 spin_lock_irqsave(&skb_pool.lock, flags); 281 while (skb_pool.qlen < MAX_SKBS) { 282 skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC); 283 if (!skb) 284 break; 285 286 __skb_queue_tail(&skb_pool, skb); 287 } 288 spin_unlock_irqrestore(&skb_pool.lock, flags); 289 } 290 291 static void zap_completion_queue(void) 292 { 293 unsigned long flags; 294 struct softnet_data *sd = &get_cpu_var(softnet_data); 295 296 if (sd->completion_queue) { 297 struct sk_buff *clist; 298 299 local_irq_save(flags); 300 clist = sd->completion_queue; 301 sd->completion_queue = NULL; 302 local_irq_restore(flags); 303 304 while (clist != NULL) { 305 struct sk_buff *skb = clist; 306 clist = clist->next; 307 if (skb->destructor) { 308 atomic_inc(&skb->users); 309 dev_kfree_skb_any(skb); /* put this one back */ 310 } else { 311 __kfree_skb(skb); 312 } 313 } 314 } 315 316 put_cpu_var(softnet_data); 317 } 318 319 static struct sk_buff *find_skb(struct netpoll *np, int len, int reserve) 320 { 321 int count = 0; 322 struct sk_buff *skb; 323 324 zap_completion_queue(); 325 refill_skbs(); 326 repeat: 327 328 skb = alloc_skb(len, GFP_ATOMIC); 329 if (!skb) 330 skb = skb_dequeue(&skb_pool); 331 332 if (!skb) { 333 if (++count < 10) { 334 netpoll_poll_dev(np->dev); 335 goto repeat; 336 } 337 return NULL; 338 } 339 340 atomic_set(&skb->users, 1); 341 skb_reserve(skb, reserve); 342 return skb; 343 } 344 345 static int netpoll_owner_active(struct net_device *dev) 346 { 347 struct napi_struct *napi; 348 349 list_for_each_entry(napi, &dev->napi_list, dev_list) { 350 if (napi->poll_owner == smp_processor_id()) 351 return 1; 352 } 353 return 0; 354 } 355 356 /* call with IRQ disabled */ 357 void netpoll_send_skb_on_dev(struct netpoll *np, struct sk_buff *skb, 358 struct net_device *dev) 359 { 360 int status = NETDEV_TX_BUSY; 361 unsigned long tries; 362 const struct net_device_ops *ops = dev->netdev_ops; 363 /* It is up to the caller to keep npinfo alive. */ 364 struct netpoll_info *npinfo; 365 366 WARN_ON_ONCE(!irqs_disabled()); 367 368 npinfo = rcu_dereference_bh(np->dev->npinfo); 369 if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) { 370 __kfree_skb(skb); 371 return; 372 } 373 374 /* don't get messages out of order, and no recursion */ 375 if (skb_queue_len(&npinfo->txq) == 0 && !netpoll_owner_active(dev)) { 376 struct netdev_queue *txq; 377 378 txq = netdev_pick_tx(dev, skb, NULL); 379 380 /* try until next clock tick */ 381 for (tries = jiffies_to_usecs(1)/USEC_PER_POLL; 382 tries > 0; --tries) { 383 if (__netif_tx_trylock(txq)) { 384 if (!netif_xmit_stopped(txq)) { 385 if (vlan_tx_tag_present(skb) && 386 !vlan_hw_offload_capable(netif_skb_features(skb), 387 skb->vlan_proto)) { 388 skb = __vlan_put_tag(skb, skb->vlan_proto, vlan_tx_tag_get(skb)); 389 if (unlikely(!skb)) { 390 /* This is actually a packet drop, but we 391 * don't want the code at the end of this 392 * function to try and re-queue a NULL skb. 393 */ 394 status = NETDEV_TX_OK; 395 goto unlock_txq; 396 } 397 skb->vlan_tci = 0; 398 } 399 400 status = ops->ndo_start_xmit(skb, dev); 401 if (status == NETDEV_TX_OK) 402 txq_trans_update(txq); 403 } 404 unlock_txq: 405 __netif_tx_unlock(txq); 406 407 if (status == NETDEV_TX_OK) 408 break; 409 410 } 411 412 /* tickle device maybe there is some cleanup */ 413 netpoll_poll_dev(np->dev); 414 415 udelay(USEC_PER_POLL); 416 } 417 418 WARN_ONCE(!irqs_disabled(), 419 "netpoll_send_skb_on_dev(): %s enabled interrupts in poll (%pF)\n", 420 dev->name, ops->ndo_start_xmit); 421 422 } 423 424 if (status != NETDEV_TX_OK) { 425 skb_queue_tail(&npinfo->txq, skb); 426 schedule_delayed_work(&npinfo->tx_work,0); 427 } 428 } 429 EXPORT_SYMBOL(netpoll_send_skb_on_dev); 430 431 void netpoll_send_udp(struct netpoll *np, const char *msg, int len) 432 { 433 int total_len, ip_len, udp_len; 434 struct sk_buff *skb; 435 struct udphdr *udph; 436 struct iphdr *iph; 437 struct ethhdr *eth; 438 static atomic_t ip_ident; 439 struct ipv6hdr *ip6h; 440 441 udp_len = len + sizeof(*udph); 442 if (np->ipv6) 443 ip_len = udp_len + sizeof(*ip6h); 444 else 445 ip_len = udp_len + sizeof(*iph); 446 447 total_len = ip_len + LL_RESERVED_SPACE(np->dev); 448 449 skb = find_skb(np, total_len + np->dev->needed_tailroom, 450 total_len - len); 451 if (!skb) 452 return; 453 454 skb_copy_to_linear_data(skb, msg, len); 455 skb_put(skb, len); 456 457 skb_push(skb, sizeof(*udph)); 458 skb_reset_transport_header(skb); 459 udph = udp_hdr(skb); 460 udph->source = htons(np->local_port); 461 udph->dest = htons(np->remote_port); 462 udph->len = htons(udp_len); 463 464 if (np->ipv6) { 465 udph->check = 0; 466 udph->check = csum_ipv6_magic(&np->local_ip.in6, 467 &np->remote_ip.in6, 468 udp_len, IPPROTO_UDP, 469 csum_partial(udph, udp_len, 0)); 470 if (udph->check == 0) 471 udph->check = CSUM_MANGLED_0; 472 473 skb_push(skb, sizeof(*ip6h)); 474 skb_reset_network_header(skb); 475 ip6h = ipv6_hdr(skb); 476 477 /* ip6h->version = 6; ip6h->priority = 0; */ 478 put_unaligned(0x60, (unsigned char *)ip6h); 479 ip6h->flow_lbl[0] = 0; 480 ip6h->flow_lbl[1] = 0; 481 ip6h->flow_lbl[2] = 0; 482 483 ip6h->payload_len = htons(sizeof(struct udphdr) + len); 484 ip6h->nexthdr = IPPROTO_UDP; 485 ip6h->hop_limit = 32; 486 ip6h->saddr = np->local_ip.in6; 487 ip6h->daddr = np->remote_ip.in6; 488 489 eth = (struct ethhdr *) skb_push(skb, ETH_HLEN); 490 skb_reset_mac_header(skb); 491 skb->protocol = eth->h_proto = htons(ETH_P_IPV6); 492 } else { 493 udph->check = 0; 494 udph->check = csum_tcpudp_magic(np->local_ip.ip, 495 np->remote_ip.ip, 496 udp_len, IPPROTO_UDP, 497 csum_partial(udph, udp_len, 0)); 498 if (udph->check == 0) 499 udph->check = CSUM_MANGLED_0; 500 501 skb_push(skb, sizeof(*iph)); 502 skb_reset_network_header(skb); 503 iph = ip_hdr(skb); 504 505 /* iph->version = 4; iph->ihl = 5; */ 506 put_unaligned(0x45, (unsigned char *)iph); 507 iph->tos = 0; 508 put_unaligned(htons(ip_len), &(iph->tot_len)); 509 iph->id = htons(atomic_inc_return(&ip_ident)); 510 iph->frag_off = 0; 511 iph->ttl = 64; 512 iph->protocol = IPPROTO_UDP; 513 iph->check = 0; 514 put_unaligned(np->local_ip.ip, &(iph->saddr)); 515 put_unaligned(np->remote_ip.ip, &(iph->daddr)); 516 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); 517 518 eth = (struct ethhdr *) skb_push(skb, ETH_HLEN); 519 skb_reset_mac_header(skb); 520 skb->protocol = eth->h_proto = htons(ETH_P_IP); 521 } 522 523 ether_addr_copy(eth->h_source, np->dev->dev_addr); 524 ether_addr_copy(eth->h_dest, np->remote_mac); 525 526 skb->dev = np->dev; 527 528 netpoll_send_skb(np, skb); 529 } 530 EXPORT_SYMBOL(netpoll_send_udp); 531 532 static void netpoll_neigh_reply(struct sk_buff *skb, struct netpoll_info *npinfo) 533 { 534 int size, type = ARPOP_REPLY; 535 __be32 sip, tip; 536 unsigned char *sha; 537 struct sk_buff *send_skb; 538 struct netpoll *np, *tmp; 539 unsigned long flags; 540 int hlen, tlen; 541 int hits = 0, proto; 542 543 if (list_empty(&npinfo->rx_np)) 544 return; 545 546 /* Before checking the packet, we do some early 547 inspection whether this is interesting at all */ 548 spin_lock_irqsave(&npinfo->rx_lock, flags); 549 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) { 550 if (np->dev == skb->dev) 551 hits++; 552 } 553 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 554 555 /* No netpoll struct is using this dev */ 556 if (!hits) 557 return; 558 559 proto = ntohs(eth_hdr(skb)->h_proto); 560 if (proto == ETH_P_ARP) { 561 struct arphdr *arp; 562 unsigned char *arp_ptr; 563 /* No arp on this interface */ 564 if (skb->dev->flags & IFF_NOARP) 565 return; 566 567 if (!pskb_may_pull(skb, arp_hdr_len(skb->dev))) 568 return; 569 570 skb_reset_network_header(skb); 571 skb_reset_transport_header(skb); 572 arp = arp_hdr(skb); 573 574 if ((arp->ar_hrd != htons(ARPHRD_ETHER) && 575 arp->ar_hrd != htons(ARPHRD_IEEE802)) || 576 arp->ar_pro != htons(ETH_P_IP) || 577 arp->ar_op != htons(ARPOP_REQUEST)) 578 return; 579 580 arp_ptr = (unsigned char *)(arp+1); 581 /* save the location of the src hw addr */ 582 sha = arp_ptr; 583 arp_ptr += skb->dev->addr_len; 584 memcpy(&sip, arp_ptr, 4); 585 arp_ptr += 4; 586 /* If we actually cared about dst hw addr, 587 it would get copied here */ 588 arp_ptr += skb->dev->addr_len; 589 memcpy(&tip, arp_ptr, 4); 590 591 /* Should we ignore arp? */ 592 if (ipv4_is_loopback(tip) || ipv4_is_multicast(tip)) 593 return; 594 595 size = arp_hdr_len(skb->dev); 596 597 spin_lock_irqsave(&npinfo->rx_lock, flags); 598 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) { 599 if (tip != np->local_ip.ip) 600 continue; 601 602 hlen = LL_RESERVED_SPACE(np->dev); 603 tlen = np->dev->needed_tailroom; 604 send_skb = find_skb(np, size + hlen + tlen, hlen); 605 if (!send_skb) 606 continue; 607 608 skb_reset_network_header(send_skb); 609 arp = (struct arphdr *) skb_put(send_skb, size); 610 send_skb->dev = skb->dev; 611 send_skb->protocol = htons(ETH_P_ARP); 612 613 /* Fill the device header for the ARP frame */ 614 if (dev_hard_header(send_skb, skb->dev, ETH_P_ARP, 615 sha, np->dev->dev_addr, 616 send_skb->len) < 0) { 617 kfree_skb(send_skb); 618 continue; 619 } 620 621 /* 622 * Fill out the arp protocol part. 623 * 624 * we only support ethernet device type, 625 * which (according to RFC 1390) should 626 * always equal 1 (Ethernet). 627 */ 628 629 arp->ar_hrd = htons(np->dev->type); 630 arp->ar_pro = htons(ETH_P_IP); 631 arp->ar_hln = np->dev->addr_len; 632 arp->ar_pln = 4; 633 arp->ar_op = htons(type); 634 635 arp_ptr = (unsigned char *)(arp + 1); 636 memcpy(arp_ptr, np->dev->dev_addr, np->dev->addr_len); 637 arp_ptr += np->dev->addr_len; 638 memcpy(arp_ptr, &tip, 4); 639 arp_ptr += 4; 640 memcpy(arp_ptr, sha, np->dev->addr_len); 641 arp_ptr += np->dev->addr_len; 642 memcpy(arp_ptr, &sip, 4); 643 644 netpoll_send_skb(np, send_skb); 645 646 /* If there are several rx_skb_hooks for the same 647 * address we're fine by sending a single reply 648 */ 649 break; 650 } 651 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 652 } else if( proto == ETH_P_IPV6) { 653 #if IS_ENABLED(CONFIG_IPV6) 654 struct nd_msg *msg; 655 u8 *lladdr = NULL; 656 struct ipv6hdr *hdr; 657 struct icmp6hdr *icmp6h; 658 const struct in6_addr *saddr; 659 const struct in6_addr *daddr; 660 struct inet6_dev *in6_dev = NULL; 661 struct in6_addr *target; 662 663 in6_dev = in6_dev_get(skb->dev); 664 if (!in6_dev || !in6_dev->cnf.accept_ra) 665 return; 666 667 if (!pskb_may_pull(skb, skb->len)) 668 return; 669 670 msg = (struct nd_msg *)skb_transport_header(skb); 671 672 __skb_push(skb, skb->data - skb_transport_header(skb)); 673 674 if (ipv6_hdr(skb)->hop_limit != 255) 675 return; 676 if (msg->icmph.icmp6_code != 0) 677 return; 678 if (msg->icmph.icmp6_type != NDISC_NEIGHBOUR_SOLICITATION) 679 return; 680 681 saddr = &ipv6_hdr(skb)->saddr; 682 daddr = &ipv6_hdr(skb)->daddr; 683 684 size = sizeof(struct icmp6hdr) + sizeof(struct in6_addr); 685 686 spin_lock_irqsave(&npinfo->rx_lock, flags); 687 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) { 688 if (!ipv6_addr_equal(daddr, &np->local_ip.in6)) 689 continue; 690 691 hlen = LL_RESERVED_SPACE(np->dev); 692 tlen = np->dev->needed_tailroom; 693 send_skb = find_skb(np, size + hlen + tlen, hlen); 694 if (!send_skb) 695 continue; 696 697 send_skb->protocol = htons(ETH_P_IPV6); 698 send_skb->dev = skb->dev; 699 700 skb_reset_network_header(send_skb); 701 hdr = (struct ipv6hdr *) skb_put(send_skb, sizeof(struct ipv6hdr)); 702 *(__be32*)hdr = htonl(0x60000000); 703 hdr->payload_len = htons(size); 704 hdr->nexthdr = IPPROTO_ICMPV6; 705 hdr->hop_limit = 255; 706 hdr->saddr = *saddr; 707 hdr->daddr = *daddr; 708 709 icmp6h = (struct icmp6hdr *) skb_put(send_skb, sizeof(struct icmp6hdr)); 710 icmp6h->icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT; 711 icmp6h->icmp6_router = 0; 712 icmp6h->icmp6_solicited = 1; 713 714 target = (struct in6_addr *) skb_put(send_skb, sizeof(struct in6_addr)); 715 *target = msg->target; 716 icmp6h->icmp6_cksum = csum_ipv6_magic(saddr, daddr, size, 717 IPPROTO_ICMPV6, 718 csum_partial(icmp6h, 719 size, 0)); 720 721 if (dev_hard_header(send_skb, skb->dev, ETH_P_IPV6, 722 lladdr, np->dev->dev_addr, 723 send_skb->len) < 0) { 724 kfree_skb(send_skb); 725 continue; 726 } 727 728 netpoll_send_skb(np, send_skb); 729 730 /* If there are several rx_skb_hooks for the same 731 * address, we're fine by sending a single reply 732 */ 733 break; 734 } 735 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 736 #endif 737 } 738 } 739 740 static bool pkt_is_ns(struct sk_buff *skb) 741 { 742 struct nd_msg *msg; 743 struct ipv6hdr *hdr; 744 745 if (skb->protocol != htons(ETH_P_ARP)) 746 return false; 747 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr) + sizeof(struct nd_msg))) 748 return false; 749 750 msg = (struct nd_msg *)skb_transport_header(skb); 751 __skb_push(skb, skb->data - skb_transport_header(skb)); 752 hdr = ipv6_hdr(skb); 753 754 if (hdr->nexthdr != IPPROTO_ICMPV6) 755 return false; 756 if (hdr->hop_limit != 255) 757 return false; 758 if (msg->icmph.icmp6_code != 0) 759 return false; 760 if (msg->icmph.icmp6_type != NDISC_NEIGHBOUR_SOLICITATION) 761 return false; 762 763 return true; 764 } 765 766 int __netpoll_rx(struct sk_buff *skb, struct netpoll_info *npinfo) 767 { 768 int proto, len, ulen, data_len; 769 int hits = 0, offset; 770 const struct iphdr *iph; 771 struct udphdr *uh; 772 struct netpoll *np, *tmp; 773 uint16_t source; 774 775 if (list_empty(&npinfo->rx_np)) 776 goto out; 777 778 if (skb->dev->type != ARPHRD_ETHER) 779 goto out; 780 781 /* check if netpoll clients need ARP */ 782 if (skb->protocol == htons(ETH_P_ARP) && atomic_read(&trapped)) { 783 skb_queue_tail(&npinfo->neigh_tx, skb); 784 return 1; 785 } else if (pkt_is_ns(skb) && atomic_read(&trapped)) { 786 skb_queue_tail(&npinfo->neigh_tx, skb); 787 return 1; 788 } 789 790 if (skb->protocol == cpu_to_be16(ETH_P_8021Q)) { 791 skb = vlan_untag(skb); 792 if (unlikely(!skb)) 793 goto out; 794 } 795 796 proto = ntohs(eth_hdr(skb)->h_proto); 797 if (proto != ETH_P_IP && proto != ETH_P_IPV6) 798 goto out; 799 if (skb->pkt_type == PACKET_OTHERHOST) 800 goto out; 801 if (skb_shared(skb)) 802 goto out; 803 804 if (proto == ETH_P_IP) { 805 if (!pskb_may_pull(skb, sizeof(struct iphdr))) 806 goto out; 807 iph = (struct iphdr *)skb->data; 808 if (iph->ihl < 5 || iph->version != 4) 809 goto out; 810 if (!pskb_may_pull(skb, iph->ihl*4)) 811 goto out; 812 iph = (struct iphdr *)skb->data; 813 if (ip_fast_csum((u8 *)iph, iph->ihl) != 0) 814 goto out; 815 816 len = ntohs(iph->tot_len); 817 if (skb->len < len || len < iph->ihl*4) 818 goto out; 819 820 /* 821 * Our transport medium may have padded the buffer out. 822 * Now We trim to the true length of the frame. 823 */ 824 if (pskb_trim_rcsum(skb, len)) 825 goto out; 826 827 iph = (struct iphdr *)skb->data; 828 if (iph->protocol != IPPROTO_UDP) 829 goto out; 830 831 len -= iph->ihl*4; 832 uh = (struct udphdr *)(((char *)iph) + iph->ihl*4); 833 offset = (unsigned char *)(uh + 1) - skb->data; 834 ulen = ntohs(uh->len); 835 data_len = skb->len - offset; 836 source = ntohs(uh->source); 837 838 if (ulen != len) 839 goto out; 840 if (checksum_udp(skb, uh, ulen, iph->saddr, iph->daddr)) 841 goto out; 842 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) { 843 if (np->local_ip.ip && np->local_ip.ip != iph->daddr) 844 continue; 845 if (np->remote_ip.ip && np->remote_ip.ip != iph->saddr) 846 continue; 847 if (np->local_port && np->local_port != ntohs(uh->dest)) 848 continue; 849 850 np->rx_skb_hook(np, source, skb, offset, data_len); 851 hits++; 852 } 853 } else { 854 #if IS_ENABLED(CONFIG_IPV6) 855 const struct ipv6hdr *ip6h; 856 857 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) 858 goto out; 859 ip6h = (struct ipv6hdr *)skb->data; 860 if (ip6h->version != 6) 861 goto out; 862 len = ntohs(ip6h->payload_len); 863 if (!len) 864 goto out; 865 if (len + sizeof(struct ipv6hdr) > skb->len) 866 goto out; 867 if (pskb_trim_rcsum(skb, len + sizeof(struct ipv6hdr))) 868 goto out; 869 ip6h = ipv6_hdr(skb); 870 if (!pskb_may_pull(skb, sizeof(struct udphdr))) 871 goto out; 872 uh = udp_hdr(skb); 873 offset = (unsigned char *)(uh + 1) - skb->data; 874 ulen = ntohs(uh->len); 875 data_len = skb->len - offset; 876 source = ntohs(uh->source); 877 if (ulen != skb->len) 878 goto out; 879 if (udp6_csum_init(skb, uh, IPPROTO_UDP)) 880 goto out; 881 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) { 882 if (!ipv6_addr_equal(&np->local_ip.in6, &ip6h->daddr)) 883 continue; 884 if (!ipv6_addr_equal(&np->remote_ip.in6, &ip6h->saddr)) 885 continue; 886 if (np->local_port && np->local_port != ntohs(uh->dest)) 887 continue; 888 889 np->rx_skb_hook(np, source, skb, offset, data_len); 890 hits++; 891 } 892 #endif 893 } 894 895 if (!hits) 896 goto out; 897 898 kfree_skb(skb); 899 return 1; 900 901 out: 902 if (atomic_read(&trapped)) { 903 kfree_skb(skb); 904 return 1; 905 } 906 907 return 0; 908 } 909 910 void netpoll_print_options(struct netpoll *np) 911 { 912 np_info(np, "local port %d\n", np->local_port); 913 if (np->ipv6) 914 np_info(np, "local IPv6 address %pI6c\n", &np->local_ip.in6); 915 else 916 np_info(np, "local IPv4 address %pI4\n", &np->local_ip.ip); 917 np_info(np, "interface '%s'\n", np->dev_name); 918 np_info(np, "remote port %d\n", np->remote_port); 919 if (np->ipv6) 920 np_info(np, "remote IPv6 address %pI6c\n", &np->remote_ip.in6); 921 else 922 np_info(np, "remote IPv4 address %pI4\n", &np->remote_ip.ip); 923 np_info(np, "remote ethernet address %pM\n", np->remote_mac); 924 } 925 EXPORT_SYMBOL(netpoll_print_options); 926 927 static int netpoll_parse_ip_addr(const char *str, union inet_addr *addr) 928 { 929 const char *end; 930 931 if (!strchr(str, ':') && 932 in4_pton(str, -1, (void *)addr, -1, &end) > 0) { 933 if (!*end) 934 return 0; 935 } 936 if (in6_pton(str, -1, addr->in6.s6_addr, -1, &end) > 0) { 937 #if IS_ENABLED(CONFIG_IPV6) 938 if (!*end) 939 return 1; 940 #else 941 return -1; 942 #endif 943 } 944 return -1; 945 } 946 947 int netpoll_parse_options(struct netpoll *np, char *opt) 948 { 949 char *cur=opt, *delim; 950 int ipv6; 951 952 if (*cur != '@') { 953 if ((delim = strchr(cur, '@')) == NULL) 954 goto parse_failed; 955 *delim = 0; 956 if (kstrtou16(cur, 10, &np->local_port)) 957 goto parse_failed; 958 cur = delim; 959 } 960 cur++; 961 962 if (*cur != '/') { 963 if ((delim = strchr(cur, '/')) == NULL) 964 goto parse_failed; 965 *delim = 0; 966 ipv6 = netpoll_parse_ip_addr(cur, &np->local_ip); 967 if (ipv6 < 0) 968 goto parse_failed; 969 else 970 np->ipv6 = (bool)ipv6; 971 cur = delim; 972 } 973 cur++; 974 975 if (*cur != ',') { 976 /* parse out dev name */ 977 if ((delim = strchr(cur, ',')) == NULL) 978 goto parse_failed; 979 *delim = 0; 980 strlcpy(np->dev_name, cur, sizeof(np->dev_name)); 981 cur = delim; 982 } 983 cur++; 984 985 if (*cur != '@') { 986 /* dst port */ 987 if ((delim = strchr(cur, '@')) == NULL) 988 goto parse_failed; 989 *delim = 0; 990 if (*cur == ' ' || *cur == '\t') 991 np_info(np, "warning: whitespace is not allowed\n"); 992 if (kstrtou16(cur, 10, &np->remote_port)) 993 goto parse_failed; 994 cur = delim; 995 } 996 cur++; 997 998 /* dst ip */ 999 if ((delim = strchr(cur, '/')) == NULL) 1000 goto parse_failed; 1001 *delim = 0; 1002 ipv6 = netpoll_parse_ip_addr(cur, &np->remote_ip); 1003 if (ipv6 < 0) 1004 goto parse_failed; 1005 else if (np->ipv6 != (bool)ipv6) 1006 goto parse_failed; 1007 else 1008 np->ipv6 = (bool)ipv6; 1009 cur = delim + 1; 1010 1011 if (*cur != 0) { 1012 /* MAC address */ 1013 if (!mac_pton(cur, np->remote_mac)) 1014 goto parse_failed; 1015 } 1016 1017 netpoll_print_options(np); 1018 1019 return 0; 1020 1021 parse_failed: 1022 np_info(np, "couldn't parse config at '%s'!\n", cur); 1023 return -1; 1024 } 1025 EXPORT_SYMBOL(netpoll_parse_options); 1026 1027 int __netpoll_setup(struct netpoll *np, struct net_device *ndev, gfp_t gfp) 1028 { 1029 struct netpoll_info *npinfo; 1030 const struct net_device_ops *ops; 1031 unsigned long flags; 1032 int err; 1033 1034 np->dev = ndev; 1035 strlcpy(np->dev_name, ndev->name, IFNAMSIZ); 1036 INIT_WORK(&np->cleanup_work, netpoll_async_cleanup); 1037 1038 if ((ndev->priv_flags & IFF_DISABLE_NETPOLL) || 1039 !ndev->netdev_ops->ndo_poll_controller) { 1040 np_err(np, "%s doesn't support polling, aborting\n", 1041 np->dev_name); 1042 err = -ENOTSUPP; 1043 goto out; 1044 } 1045 1046 if (!ndev->npinfo) { 1047 npinfo = kmalloc(sizeof(*npinfo), gfp); 1048 if (!npinfo) { 1049 err = -ENOMEM; 1050 goto out; 1051 } 1052 1053 npinfo->rx_flags = 0; 1054 INIT_LIST_HEAD(&npinfo->rx_np); 1055 1056 spin_lock_init(&npinfo->rx_lock); 1057 sema_init(&npinfo->dev_lock, 1); 1058 skb_queue_head_init(&npinfo->neigh_tx); 1059 skb_queue_head_init(&npinfo->txq); 1060 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process); 1061 1062 atomic_set(&npinfo->refcnt, 1); 1063 1064 ops = np->dev->netdev_ops; 1065 if (ops->ndo_netpoll_setup) { 1066 err = ops->ndo_netpoll_setup(ndev, npinfo, gfp); 1067 if (err) 1068 goto free_npinfo; 1069 } 1070 } else { 1071 npinfo = rtnl_dereference(ndev->npinfo); 1072 atomic_inc(&npinfo->refcnt); 1073 } 1074 1075 npinfo->netpoll = np; 1076 1077 if (np->rx_skb_hook) { 1078 spin_lock_irqsave(&npinfo->rx_lock, flags); 1079 npinfo->rx_flags |= NETPOLL_RX_ENABLED; 1080 list_add_tail(&np->rx, &npinfo->rx_np); 1081 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 1082 } 1083 1084 /* last thing to do is link it to the net device structure */ 1085 rcu_assign_pointer(ndev->npinfo, npinfo); 1086 1087 return 0; 1088 1089 free_npinfo: 1090 kfree(npinfo); 1091 out: 1092 return err; 1093 } 1094 EXPORT_SYMBOL_GPL(__netpoll_setup); 1095 1096 int netpoll_setup(struct netpoll *np) 1097 { 1098 struct net_device *ndev = NULL; 1099 struct in_device *in_dev; 1100 int err; 1101 1102 rtnl_lock(); 1103 if (np->dev_name) { 1104 struct net *net = current->nsproxy->net_ns; 1105 ndev = __dev_get_by_name(net, np->dev_name); 1106 } 1107 if (!ndev) { 1108 np_err(np, "%s doesn't exist, aborting\n", np->dev_name); 1109 err = -ENODEV; 1110 goto unlock; 1111 } 1112 dev_hold(ndev); 1113 1114 if (netdev_master_upper_dev_get(ndev)) { 1115 np_err(np, "%s is a slave device, aborting\n", np->dev_name); 1116 err = -EBUSY; 1117 goto put; 1118 } 1119 1120 if (!netif_running(ndev)) { 1121 unsigned long atmost, atleast; 1122 1123 np_info(np, "device %s not up yet, forcing it\n", np->dev_name); 1124 1125 err = dev_open(ndev); 1126 1127 if (err) { 1128 np_err(np, "failed to open %s\n", ndev->name); 1129 goto put; 1130 } 1131 1132 rtnl_unlock(); 1133 atleast = jiffies + HZ/10; 1134 atmost = jiffies + carrier_timeout * HZ; 1135 while (!netif_carrier_ok(ndev)) { 1136 if (time_after(jiffies, atmost)) { 1137 np_notice(np, "timeout waiting for carrier\n"); 1138 break; 1139 } 1140 msleep(1); 1141 } 1142 1143 /* If carrier appears to come up instantly, we don't 1144 * trust it and pause so that we don't pump all our 1145 * queued console messages into the bitbucket. 1146 */ 1147 1148 if (time_before(jiffies, atleast)) { 1149 np_notice(np, "carrier detect appears untrustworthy, waiting 4 seconds\n"); 1150 msleep(4000); 1151 } 1152 rtnl_lock(); 1153 } 1154 1155 if (!np->local_ip.ip) { 1156 if (!np->ipv6) { 1157 in_dev = __in_dev_get_rtnl(ndev); 1158 1159 if (!in_dev || !in_dev->ifa_list) { 1160 np_err(np, "no IP address for %s, aborting\n", 1161 np->dev_name); 1162 err = -EDESTADDRREQ; 1163 goto put; 1164 } 1165 1166 np->local_ip.ip = in_dev->ifa_list->ifa_local; 1167 np_info(np, "local IP %pI4\n", &np->local_ip.ip); 1168 } else { 1169 #if IS_ENABLED(CONFIG_IPV6) 1170 struct inet6_dev *idev; 1171 1172 err = -EDESTADDRREQ; 1173 idev = __in6_dev_get(ndev); 1174 if (idev) { 1175 struct inet6_ifaddr *ifp; 1176 1177 read_lock_bh(&idev->lock); 1178 list_for_each_entry(ifp, &idev->addr_list, if_list) { 1179 if (ipv6_addr_type(&ifp->addr) & IPV6_ADDR_LINKLOCAL) 1180 continue; 1181 np->local_ip.in6 = ifp->addr; 1182 err = 0; 1183 break; 1184 } 1185 read_unlock_bh(&idev->lock); 1186 } 1187 if (err) { 1188 np_err(np, "no IPv6 address for %s, aborting\n", 1189 np->dev_name); 1190 goto put; 1191 } else 1192 np_info(np, "local IPv6 %pI6c\n", &np->local_ip.in6); 1193 #else 1194 np_err(np, "IPv6 is not supported %s, aborting\n", 1195 np->dev_name); 1196 err = -EINVAL; 1197 goto put; 1198 #endif 1199 } 1200 } 1201 1202 /* fill up the skb queue */ 1203 refill_skbs(); 1204 1205 err = __netpoll_setup(np, ndev, GFP_KERNEL); 1206 if (err) 1207 goto put; 1208 1209 rtnl_unlock(); 1210 return 0; 1211 1212 put: 1213 dev_put(ndev); 1214 unlock: 1215 rtnl_unlock(); 1216 return err; 1217 } 1218 EXPORT_SYMBOL(netpoll_setup); 1219 1220 static int __init netpoll_init(void) 1221 { 1222 skb_queue_head_init(&skb_pool); 1223 return 0; 1224 } 1225 core_initcall(netpoll_init); 1226 1227 static void rcu_cleanup_netpoll_info(struct rcu_head *rcu_head) 1228 { 1229 struct netpoll_info *npinfo = 1230 container_of(rcu_head, struct netpoll_info, rcu); 1231 1232 skb_queue_purge(&npinfo->neigh_tx); 1233 skb_queue_purge(&npinfo->txq); 1234 1235 /* we can't call cancel_delayed_work_sync here, as we are in softirq */ 1236 cancel_delayed_work(&npinfo->tx_work); 1237 1238 /* clean after last, unfinished work */ 1239 __skb_queue_purge(&npinfo->txq); 1240 /* now cancel it again */ 1241 cancel_delayed_work(&npinfo->tx_work); 1242 kfree(npinfo); 1243 } 1244 1245 void __netpoll_cleanup(struct netpoll *np) 1246 { 1247 struct netpoll_info *npinfo; 1248 unsigned long flags; 1249 1250 /* rtnl_dereference would be preferable here but 1251 * rcu_cleanup_netpoll path can put us in here safely without 1252 * holding the rtnl, so plain rcu_dereference it is 1253 */ 1254 npinfo = rtnl_dereference(np->dev->npinfo); 1255 if (!npinfo) 1256 return; 1257 1258 if (!list_empty(&npinfo->rx_np)) { 1259 spin_lock_irqsave(&npinfo->rx_lock, flags); 1260 list_del(&np->rx); 1261 if (list_empty(&npinfo->rx_np)) 1262 npinfo->rx_flags &= ~NETPOLL_RX_ENABLED; 1263 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 1264 } 1265 1266 synchronize_srcu(&netpoll_srcu); 1267 1268 if (atomic_dec_and_test(&npinfo->refcnt)) { 1269 const struct net_device_ops *ops; 1270 1271 ops = np->dev->netdev_ops; 1272 if (ops->ndo_netpoll_cleanup) 1273 ops->ndo_netpoll_cleanup(np->dev); 1274 1275 rcu_assign_pointer(np->dev->npinfo, NULL); 1276 call_rcu_bh(&npinfo->rcu, rcu_cleanup_netpoll_info); 1277 } 1278 } 1279 EXPORT_SYMBOL_GPL(__netpoll_cleanup); 1280 1281 static void netpoll_async_cleanup(struct work_struct *work) 1282 { 1283 struct netpoll *np = container_of(work, struct netpoll, cleanup_work); 1284 1285 rtnl_lock(); 1286 __netpoll_cleanup(np); 1287 rtnl_unlock(); 1288 kfree(np); 1289 } 1290 1291 void __netpoll_free_async(struct netpoll *np) 1292 { 1293 schedule_work(&np->cleanup_work); 1294 } 1295 EXPORT_SYMBOL_GPL(__netpoll_free_async); 1296 1297 void netpoll_cleanup(struct netpoll *np) 1298 { 1299 rtnl_lock(); 1300 if (!np->dev) 1301 goto out; 1302 __netpoll_cleanup(np); 1303 dev_put(np->dev); 1304 np->dev = NULL; 1305 out: 1306 rtnl_unlock(); 1307 } 1308 EXPORT_SYMBOL(netpoll_cleanup); 1309 1310 int netpoll_trap(void) 1311 { 1312 return atomic_read(&trapped); 1313 } 1314 EXPORT_SYMBOL(netpoll_trap); 1315 1316 void netpoll_set_trap(int trap) 1317 { 1318 if (trap) 1319 atomic_inc(&trapped); 1320 else 1321 atomic_dec(&trapped); 1322 } 1323 EXPORT_SYMBOL(netpoll_set_trap); 1324