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); 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 break; 391 skb->vlan_tci = 0; 392 } 393 394 status = ops->ndo_start_xmit(skb, dev); 395 if (status == NETDEV_TX_OK) 396 txq_trans_update(txq); 397 } 398 __netif_tx_unlock(txq); 399 400 if (status == NETDEV_TX_OK) 401 break; 402 403 } 404 405 /* tickle device maybe there is some cleanup */ 406 netpoll_poll_dev(np->dev); 407 408 udelay(USEC_PER_POLL); 409 } 410 411 WARN_ONCE(!irqs_disabled(), 412 "netpoll_send_skb_on_dev(): %s enabled interrupts in poll (%pF)\n", 413 dev->name, ops->ndo_start_xmit); 414 415 } 416 417 if (status != NETDEV_TX_OK) { 418 skb_queue_tail(&npinfo->txq, skb); 419 schedule_delayed_work(&npinfo->tx_work,0); 420 } 421 } 422 EXPORT_SYMBOL(netpoll_send_skb_on_dev); 423 424 void netpoll_send_udp(struct netpoll *np, const char *msg, int len) 425 { 426 int total_len, ip_len, udp_len; 427 struct sk_buff *skb; 428 struct udphdr *udph; 429 struct iphdr *iph; 430 struct ethhdr *eth; 431 static atomic_t ip_ident; 432 struct ipv6hdr *ip6h; 433 434 udp_len = len + sizeof(*udph); 435 if (np->ipv6) 436 ip_len = udp_len + sizeof(*ip6h); 437 else 438 ip_len = udp_len + sizeof(*iph); 439 440 total_len = ip_len + LL_RESERVED_SPACE(np->dev); 441 442 skb = find_skb(np, total_len + np->dev->needed_tailroom, 443 total_len - len); 444 if (!skb) 445 return; 446 447 skb_copy_to_linear_data(skb, msg, len); 448 skb_put(skb, len); 449 450 skb_push(skb, sizeof(*udph)); 451 skb_reset_transport_header(skb); 452 udph = udp_hdr(skb); 453 udph->source = htons(np->local_port); 454 udph->dest = htons(np->remote_port); 455 udph->len = htons(udp_len); 456 457 if (np->ipv6) { 458 udph->check = 0; 459 udph->check = csum_ipv6_magic(&np->local_ip.in6, 460 &np->remote_ip.in6, 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(*ip6h)); 467 skb_reset_network_header(skb); 468 ip6h = ipv6_hdr(skb); 469 470 /* ip6h->version = 6; ip6h->priority = 0; */ 471 put_unaligned(0x60, (unsigned char *)ip6h); 472 ip6h->flow_lbl[0] = 0; 473 ip6h->flow_lbl[1] = 0; 474 ip6h->flow_lbl[2] = 0; 475 476 ip6h->payload_len = htons(sizeof(struct udphdr) + len); 477 ip6h->nexthdr = IPPROTO_UDP; 478 ip6h->hop_limit = 32; 479 ip6h->saddr = np->local_ip.in6; 480 ip6h->daddr = np->remote_ip.in6; 481 482 eth = (struct ethhdr *) skb_push(skb, ETH_HLEN); 483 skb_reset_mac_header(skb); 484 skb->protocol = eth->h_proto = htons(ETH_P_IPV6); 485 } else { 486 udph->check = 0; 487 udph->check = csum_tcpudp_magic(np->local_ip.ip, 488 np->remote_ip.ip, 489 udp_len, IPPROTO_UDP, 490 csum_partial(udph, udp_len, 0)); 491 if (udph->check == 0) 492 udph->check = CSUM_MANGLED_0; 493 494 skb_push(skb, sizeof(*iph)); 495 skb_reset_network_header(skb); 496 iph = ip_hdr(skb); 497 498 /* iph->version = 4; iph->ihl = 5; */ 499 put_unaligned(0x45, (unsigned char *)iph); 500 iph->tos = 0; 501 put_unaligned(htons(ip_len), &(iph->tot_len)); 502 iph->id = htons(atomic_inc_return(&ip_ident)); 503 iph->frag_off = 0; 504 iph->ttl = 64; 505 iph->protocol = IPPROTO_UDP; 506 iph->check = 0; 507 put_unaligned(np->local_ip.ip, &(iph->saddr)); 508 put_unaligned(np->remote_ip.ip, &(iph->daddr)); 509 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); 510 511 eth = (struct ethhdr *) skb_push(skb, ETH_HLEN); 512 skb_reset_mac_header(skb); 513 skb->protocol = eth->h_proto = htons(ETH_P_IP); 514 } 515 516 memcpy(eth->h_source, np->dev->dev_addr, ETH_ALEN); 517 memcpy(eth->h_dest, np->remote_mac, ETH_ALEN); 518 519 skb->dev = np->dev; 520 521 netpoll_send_skb(np, skb); 522 } 523 EXPORT_SYMBOL(netpoll_send_udp); 524 525 static void netpoll_neigh_reply(struct sk_buff *skb, struct netpoll_info *npinfo) 526 { 527 int size, type = ARPOP_REPLY; 528 __be32 sip, tip; 529 unsigned char *sha; 530 struct sk_buff *send_skb; 531 struct netpoll *np, *tmp; 532 unsigned long flags; 533 int hlen, tlen; 534 int hits = 0, proto; 535 536 if (list_empty(&npinfo->rx_np)) 537 return; 538 539 /* Before checking the packet, we do some early 540 inspection whether this is interesting at all */ 541 spin_lock_irqsave(&npinfo->rx_lock, flags); 542 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) { 543 if (np->dev == skb->dev) 544 hits++; 545 } 546 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 547 548 /* No netpoll struct is using this dev */ 549 if (!hits) 550 return; 551 552 proto = ntohs(eth_hdr(skb)->h_proto); 553 if (proto == ETH_P_ARP) { 554 struct arphdr *arp; 555 unsigned char *arp_ptr; 556 /* No arp on this interface */ 557 if (skb->dev->flags & IFF_NOARP) 558 return; 559 560 if (!pskb_may_pull(skb, arp_hdr_len(skb->dev))) 561 return; 562 563 skb_reset_network_header(skb); 564 skb_reset_transport_header(skb); 565 arp = arp_hdr(skb); 566 567 if ((arp->ar_hrd != htons(ARPHRD_ETHER) && 568 arp->ar_hrd != htons(ARPHRD_IEEE802)) || 569 arp->ar_pro != htons(ETH_P_IP) || 570 arp->ar_op != htons(ARPOP_REQUEST)) 571 return; 572 573 arp_ptr = (unsigned char *)(arp+1); 574 /* save the location of the src hw addr */ 575 sha = arp_ptr; 576 arp_ptr += skb->dev->addr_len; 577 memcpy(&sip, arp_ptr, 4); 578 arp_ptr += 4; 579 /* If we actually cared about dst hw addr, 580 it would get copied here */ 581 arp_ptr += skb->dev->addr_len; 582 memcpy(&tip, arp_ptr, 4); 583 584 /* Should we ignore arp? */ 585 if (ipv4_is_loopback(tip) || ipv4_is_multicast(tip)) 586 return; 587 588 size = arp_hdr_len(skb->dev); 589 590 spin_lock_irqsave(&npinfo->rx_lock, flags); 591 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) { 592 if (tip != np->local_ip.ip) 593 continue; 594 595 hlen = LL_RESERVED_SPACE(np->dev); 596 tlen = np->dev->needed_tailroom; 597 send_skb = find_skb(np, size + hlen + tlen, hlen); 598 if (!send_skb) 599 continue; 600 601 skb_reset_network_header(send_skb); 602 arp = (struct arphdr *) skb_put(send_skb, size); 603 send_skb->dev = skb->dev; 604 send_skb->protocol = htons(ETH_P_ARP); 605 606 /* Fill the device header for the ARP frame */ 607 if (dev_hard_header(send_skb, skb->dev, ETH_P_ARP, 608 sha, np->dev->dev_addr, 609 send_skb->len) < 0) { 610 kfree_skb(send_skb); 611 continue; 612 } 613 614 /* 615 * Fill out the arp protocol part. 616 * 617 * we only support ethernet device type, 618 * which (according to RFC 1390) should 619 * always equal 1 (Ethernet). 620 */ 621 622 arp->ar_hrd = htons(np->dev->type); 623 arp->ar_pro = htons(ETH_P_IP); 624 arp->ar_hln = np->dev->addr_len; 625 arp->ar_pln = 4; 626 arp->ar_op = htons(type); 627 628 arp_ptr = (unsigned char *)(arp + 1); 629 memcpy(arp_ptr, np->dev->dev_addr, np->dev->addr_len); 630 arp_ptr += np->dev->addr_len; 631 memcpy(arp_ptr, &tip, 4); 632 arp_ptr += 4; 633 memcpy(arp_ptr, sha, np->dev->addr_len); 634 arp_ptr += np->dev->addr_len; 635 memcpy(arp_ptr, &sip, 4); 636 637 netpoll_send_skb(np, send_skb); 638 639 /* If there are several rx_skb_hooks for the same 640 * address we're fine by sending a single reply 641 */ 642 break; 643 } 644 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 645 } else if( proto == ETH_P_IPV6) { 646 #if IS_ENABLED(CONFIG_IPV6) 647 struct nd_msg *msg; 648 u8 *lladdr = NULL; 649 struct ipv6hdr *hdr; 650 struct icmp6hdr *icmp6h; 651 const struct in6_addr *saddr; 652 const struct in6_addr *daddr; 653 struct inet6_dev *in6_dev = NULL; 654 struct in6_addr *target; 655 656 in6_dev = in6_dev_get(skb->dev); 657 if (!in6_dev || !in6_dev->cnf.accept_ra) 658 return; 659 660 if (!pskb_may_pull(skb, skb->len)) 661 return; 662 663 msg = (struct nd_msg *)skb_transport_header(skb); 664 665 __skb_push(skb, skb->data - skb_transport_header(skb)); 666 667 if (ipv6_hdr(skb)->hop_limit != 255) 668 return; 669 if (msg->icmph.icmp6_code != 0) 670 return; 671 if (msg->icmph.icmp6_type != NDISC_NEIGHBOUR_SOLICITATION) 672 return; 673 674 saddr = &ipv6_hdr(skb)->saddr; 675 daddr = &ipv6_hdr(skb)->daddr; 676 677 size = sizeof(struct icmp6hdr) + sizeof(struct in6_addr); 678 679 spin_lock_irqsave(&npinfo->rx_lock, flags); 680 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) { 681 if (!ipv6_addr_equal(daddr, &np->local_ip.in6)) 682 continue; 683 684 hlen = LL_RESERVED_SPACE(np->dev); 685 tlen = np->dev->needed_tailroom; 686 send_skb = find_skb(np, size + hlen + tlen, hlen); 687 if (!send_skb) 688 continue; 689 690 send_skb->protocol = htons(ETH_P_IPV6); 691 send_skb->dev = skb->dev; 692 693 skb_reset_network_header(send_skb); 694 hdr = (struct ipv6hdr *) skb_put(send_skb, sizeof(struct ipv6hdr)); 695 *(__be32*)hdr = htonl(0x60000000); 696 hdr->payload_len = htons(size); 697 hdr->nexthdr = IPPROTO_ICMPV6; 698 hdr->hop_limit = 255; 699 hdr->saddr = *saddr; 700 hdr->daddr = *daddr; 701 702 icmp6h = (struct icmp6hdr *) skb_put(send_skb, sizeof(struct icmp6hdr)); 703 icmp6h->icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT; 704 icmp6h->icmp6_router = 0; 705 icmp6h->icmp6_solicited = 1; 706 707 target = (struct in6_addr *) skb_put(send_skb, sizeof(struct in6_addr)); 708 *target = msg->target; 709 icmp6h->icmp6_cksum = csum_ipv6_magic(saddr, daddr, size, 710 IPPROTO_ICMPV6, 711 csum_partial(icmp6h, 712 size, 0)); 713 714 if (dev_hard_header(send_skb, skb->dev, ETH_P_IPV6, 715 lladdr, np->dev->dev_addr, 716 send_skb->len) < 0) { 717 kfree_skb(send_skb); 718 continue; 719 } 720 721 netpoll_send_skb(np, send_skb); 722 723 /* If there are several rx_skb_hooks for the same 724 * address, we're fine by sending a single reply 725 */ 726 break; 727 } 728 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 729 #endif 730 } 731 } 732 733 static bool pkt_is_ns(struct sk_buff *skb) 734 { 735 struct nd_msg *msg; 736 struct ipv6hdr *hdr; 737 738 if (skb->protocol != htons(ETH_P_ARP)) 739 return false; 740 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr) + sizeof(struct nd_msg))) 741 return false; 742 743 msg = (struct nd_msg *)skb_transport_header(skb); 744 __skb_push(skb, skb->data - skb_transport_header(skb)); 745 hdr = ipv6_hdr(skb); 746 747 if (hdr->nexthdr != IPPROTO_ICMPV6) 748 return false; 749 if (hdr->hop_limit != 255) 750 return false; 751 if (msg->icmph.icmp6_code != 0) 752 return false; 753 if (msg->icmph.icmp6_type != NDISC_NEIGHBOUR_SOLICITATION) 754 return false; 755 756 return true; 757 } 758 759 int __netpoll_rx(struct sk_buff *skb, struct netpoll_info *npinfo) 760 { 761 int proto, len, ulen, data_len; 762 int hits = 0, offset; 763 const struct iphdr *iph; 764 struct udphdr *uh; 765 struct netpoll *np, *tmp; 766 uint16_t source; 767 768 if (list_empty(&npinfo->rx_np)) 769 goto out; 770 771 if (skb->dev->type != ARPHRD_ETHER) 772 goto out; 773 774 /* check if netpoll clients need ARP */ 775 if (skb->protocol == htons(ETH_P_ARP) && atomic_read(&trapped)) { 776 skb_queue_tail(&npinfo->neigh_tx, skb); 777 return 1; 778 } else if (pkt_is_ns(skb) && atomic_read(&trapped)) { 779 skb_queue_tail(&npinfo->neigh_tx, skb); 780 return 1; 781 } 782 783 if (skb->protocol == cpu_to_be16(ETH_P_8021Q)) { 784 skb = vlan_untag(skb); 785 if (unlikely(!skb)) 786 goto out; 787 } 788 789 proto = ntohs(eth_hdr(skb)->h_proto); 790 if (proto != ETH_P_IP && proto != ETH_P_IPV6) 791 goto out; 792 if (skb->pkt_type == PACKET_OTHERHOST) 793 goto out; 794 if (skb_shared(skb)) 795 goto out; 796 797 if (proto == ETH_P_IP) { 798 if (!pskb_may_pull(skb, sizeof(struct iphdr))) 799 goto out; 800 iph = (struct iphdr *)skb->data; 801 if (iph->ihl < 5 || iph->version != 4) 802 goto out; 803 if (!pskb_may_pull(skb, iph->ihl*4)) 804 goto out; 805 iph = (struct iphdr *)skb->data; 806 if (ip_fast_csum((u8 *)iph, iph->ihl) != 0) 807 goto out; 808 809 len = ntohs(iph->tot_len); 810 if (skb->len < len || len < iph->ihl*4) 811 goto out; 812 813 /* 814 * Our transport medium may have padded the buffer out. 815 * Now We trim to the true length of the frame. 816 */ 817 if (pskb_trim_rcsum(skb, len)) 818 goto out; 819 820 iph = (struct iphdr *)skb->data; 821 if (iph->protocol != IPPROTO_UDP) 822 goto out; 823 824 len -= iph->ihl*4; 825 uh = (struct udphdr *)(((char *)iph) + iph->ihl*4); 826 offset = (unsigned char *)(uh + 1) - skb->data; 827 ulen = ntohs(uh->len); 828 data_len = skb->len - offset; 829 source = ntohs(uh->source); 830 831 if (ulen != len) 832 goto out; 833 if (checksum_udp(skb, uh, ulen, iph->saddr, iph->daddr)) 834 goto out; 835 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) { 836 if (np->local_ip.ip && np->local_ip.ip != iph->daddr) 837 continue; 838 if (np->remote_ip.ip && np->remote_ip.ip != iph->saddr) 839 continue; 840 if (np->local_port && np->local_port != ntohs(uh->dest)) 841 continue; 842 843 np->rx_skb_hook(np, source, skb, offset, data_len); 844 hits++; 845 } 846 } else { 847 #if IS_ENABLED(CONFIG_IPV6) 848 const struct ipv6hdr *ip6h; 849 850 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) 851 goto out; 852 ip6h = (struct ipv6hdr *)skb->data; 853 if (ip6h->version != 6) 854 goto out; 855 len = ntohs(ip6h->payload_len); 856 if (!len) 857 goto out; 858 if (len + sizeof(struct ipv6hdr) > skb->len) 859 goto out; 860 if (pskb_trim_rcsum(skb, len + sizeof(struct ipv6hdr))) 861 goto out; 862 ip6h = ipv6_hdr(skb); 863 if (!pskb_may_pull(skb, sizeof(struct udphdr))) 864 goto out; 865 uh = udp_hdr(skb); 866 offset = (unsigned char *)(uh + 1) - skb->data; 867 ulen = ntohs(uh->len); 868 data_len = skb->len - offset; 869 source = ntohs(uh->source); 870 if (ulen != skb->len) 871 goto out; 872 if (udp6_csum_init(skb, uh, IPPROTO_UDP)) 873 goto out; 874 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) { 875 if (!ipv6_addr_equal(&np->local_ip.in6, &ip6h->daddr)) 876 continue; 877 if (!ipv6_addr_equal(&np->remote_ip.in6, &ip6h->saddr)) 878 continue; 879 if (np->local_port && np->local_port != ntohs(uh->dest)) 880 continue; 881 882 np->rx_skb_hook(np, source, skb, offset, data_len); 883 hits++; 884 } 885 #endif 886 } 887 888 if (!hits) 889 goto out; 890 891 kfree_skb(skb); 892 return 1; 893 894 out: 895 if (atomic_read(&trapped)) { 896 kfree_skb(skb); 897 return 1; 898 } 899 900 return 0; 901 } 902 903 void netpoll_print_options(struct netpoll *np) 904 { 905 np_info(np, "local port %d\n", np->local_port); 906 if (np->ipv6) 907 np_info(np, "local IPv6 address %pI6c\n", &np->local_ip.in6); 908 else 909 np_info(np, "local IPv4 address %pI4\n", &np->local_ip.ip); 910 np_info(np, "interface '%s'\n", np->dev_name); 911 np_info(np, "remote port %d\n", np->remote_port); 912 if (np->ipv6) 913 np_info(np, "remote IPv6 address %pI6c\n", &np->remote_ip.in6); 914 else 915 np_info(np, "remote IPv4 address %pI4\n", &np->remote_ip.ip); 916 np_info(np, "remote ethernet address %pM\n", np->remote_mac); 917 } 918 EXPORT_SYMBOL(netpoll_print_options); 919 920 static int netpoll_parse_ip_addr(const char *str, union inet_addr *addr) 921 { 922 const char *end; 923 924 if (!strchr(str, ':') && 925 in4_pton(str, -1, (void *)addr, -1, &end) > 0) { 926 if (!*end) 927 return 0; 928 } 929 if (in6_pton(str, -1, addr->in6.s6_addr, -1, &end) > 0) { 930 #if IS_ENABLED(CONFIG_IPV6) 931 if (!*end) 932 return 1; 933 #else 934 return -1; 935 #endif 936 } 937 return -1; 938 } 939 940 int netpoll_parse_options(struct netpoll *np, char *opt) 941 { 942 char *cur=opt, *delim; 943 int ipv6; 944 945 if (*cur != '@') { 946 if ((delim = strchr(cur, '@')) == NULL) 947 goto parse_failed; 948 *delim = 0; 949 if (kstrtou16(cur, 10, &np->local_port)) 950 goto parse_failed; 951 cur = delim; 952 } 953 cur++; 954 955 if (*cur != '/') { 956 if ((delim = strchr(cur, '/')) == NULL) 957 goto parse_failed; 958 *delim = 0; 959 ipv6 = netpoll_parse_ip_addr(cur, &np->local_ip); 960 if (ipv6 < 0) 961 goto parse_failed; 962 else 963 np->ipv6 = (bool)ipv6; 964 cur = delim; 965 } 966 cur++; 967 968 if (*cur != ',') { 969 /* parse out dev name */ 970 if ((delim = strchr(cur, ',')) == NULL) 971 goto parse_failed; 972 *delim = 0; 973 strlcpy(np->dev_name, cur, sizeof(np->dev_name)); 974 cur = delim; 975 } 976 cur++; 977 978 if (*cur != '@') { 979 /* dst port */ 980 if ((delim = strchr(cur, '@')) == NULL) 981 goto parse_failed; 982 *delim = 0; 983 if (*cur == ' ' || *cur == '\t') 984 np_info(np, "warning: whitespace is not allowed\n"); 985 if (kstrtou16(cur, 10, &np->remote_port)) 986 goto parse_failed; 987 cur = delim; 988 } 989 cur++; 990 991 /* dst ip */ 992 if ((delim = strchr(cur, '/')) == NULL) 993 goto parse_failed; 994 *delim = 0; 995 ipv6 = netpoll_parse_ip_addr(cur, &np->remote_ip); 996 if (ipv6 < 0) 997 goto parse_failed; 998 else if (np->ipv6 != (bool)ipv6) 999 goto parse_failed; 1000 else 1001 np->ipv6 = (bool)ipv6; 1002 cur = delim + 1; 1003 1004 if (*cur != 0) { 1005 /* MAC address */ 1006 if (!mac_pton(cur, np->remote_mac)) 1007 goto parse_failed; 1008 } 1009 1010 netpoll_print_options(np); 1011 1012 return 0; 1013 1014 parse_failed: 1015 np_info(np, "couldn't parse config at '%s'!\n", cur); 1016 return -1; 1017 } 1018 EXPORT_SYMBOL(netpoll_parse_options); 1019 1020 int __netpoll_setup(struct netpoll *np, struct net_device *ndev, gfp_t gfp) 1021 { 1022 struct netpoll_info *npinfo; 1023 const struct net_device_ops *ops; 1024 unsigned long flags; 1025 int err; 1026 1027 np->dev = ndev; 1028 strlcpy(np->dev_name, ndev->name, IFNAMSIZ); 1029 INIT_WORK(&np->cleanup_work, netpoll_async_cleanup); 1030 1031 if ((ndev->priv_flags & IFF_DISABLE_NETPOLL) || 1032 !ndev->netdev_ops->ndo_poll_controller) { 1033 np_err(np, "%s doesn't support polling, aborting\n", 1034 np->dev_name); 1035 err = -ENOTSUPP; 1036 goto out; 1037 } 1038 1039 if (!ndev->npinfo) { 1040 npinfo = kmalloc(sizeof(*npinfo), gfp); 1041 if (!npinfo) { 1042 err = -ENOMEM; 1043 goto out; 1044 } 1045 1046 npinfo->rx_flags = 0; 1047 INIT_LIST_HEAD(&npinfo->rx_np); 1048 1049 spin_lock_init(&npinfo->rx_lock); 1050 sema_init(&npinfo->dev_lock, 1); 1051 skb_queue_head_init(&npinfo->neigh_tx); 1052 skb_queue_head_init(&npinfo->txq); 1053 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process); 1054 1055 atomic_set(&npinfo->refcnt, 1); 1056 1057 ops = np->dev->netdev_ops; 1058 if (ops->ndo_netpoll_setup) { 1059 err = ops->ndo_netpoll_setup(ndev, npinfo, gfp); 1060 if (err) 1061 goto free_npinfo; 1062 } 1063 } else { 1064 npinfo = rtnl_dereference(ndev->npinfo); 1065 atomic_inc(&npinfo->refcnt); 1066 } 1067 1068 npinfo->netpoll = np; 1069 1070 if (np->rx_skb_hook) { 1071 spin_lock_irqsave(&npinfo->rx_lock, flags); 1072 npinfo->rx_flags |= NETPOLL_RX_ENABLED; 1073 list_add_tail(&np->rx, &npinfo->rx_np); 1074 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 1075 } 1076 1077 /* last thing to do is link it to the net device structure */ 1078 rcu_assign_pointer(ndev->npinfo, npinfo); 1079 1080 return 0; 1081 1082 free_npinfo: 1083 kfree(npinfo); 1084 out: 1085 return err; 1086 } 1087 EXPORT_SYMBOL_GPL(__netpoll_setup); 1088 1089 int netpoll_setup(struct netpoll *np) 1090 { 1091 struct net_device *ndev = NULL; 1092 struct in_device *in_dev; 1093 int err; 1094 1095 rtnl_lock(); 1096 if (np->dev_name) { 1097 struct net *net = current->nsproxy->net_ns; 1098 ndev = __dev_get_by_name(net, np->dev_name); 1099 } 1100 if (!ndev) { 1101 np_err(np, "%s doesn't exist, aborting\n", np->dev_name); 1102 err = -ENODEV; 1103 goto unlock; 1104 } 1105 dev_hold(ndev); 1106 1107 if (netdev_master_upper_dev_get(ndev)) { 1108 np_err(np, "%s is a slave device, aborting\n", np->dev_name); 1109 err = -EBUSY; 1110 goto put; 1111 } 1112 1113 if (!netif_running(ndev)) { 1114 unsigned long atmost, atleast; 1115 1116 np_info(np, "device %s not up yet, forcing it\n", np->dev_name); 1117 1118 err = dev_open(ndev); 1119 1120 if (err) { 1121 np_err(np, "failed to open %s\n", ndev->name); 1122 goto put; 1123 } 1124 1125 rtnl_unlock(); 1126 atleast = jiffies + HZ/10; 1127 atmost = jiffies + carrier_timeout * HZ; 1128 while (!netif_carrier_ok(ndev)) { 1129 if (time_after(jiffies, atmost)) { 1130 np_notice(np, "timeout waiting for carrier\n"); 1131 break; 1132 } 1133 msleep(1); 1134 } 1135 1136 /* If carrier appears to come up instantly, we don't 1137 * trust it and pause so that we don't pump all our 1138 * queued console messages into the bitbucket. 1139 */ 1140 1141 if (time_before(jiffies, atleast)) { 1142 np_notice(np, "carrier detect appears untrustworthy, waiting 4 seconds\n"); 1143 msleep(4000); 1144 } 1145 rtnl_lock(); 1146 } 1147 1148 if (!np->local_ip.ip) { 1149 if (!np->ipv6) { 1150 in_dev = __in_dev_get_rtnl(ndev); 1151 1152 if (!in_dev || !in_dev->ifa_list) { 1153 np_err(np, "no IP address for %s, aborting\n", 1154 np->dev_name); 1155 err = -EDESTADDRREQ; 1156 goto put; 1157 } 1158 1159 np->local_ip.ip = in_dev->ifa_list->ifa_local; 1160 np_info(np, "local IP %pI4\n", &np->local_ip.ip); 1161 } else { 1162 #if IS_ENABLED(CONFIG_IPV6) 1163 struct inet6_dev *idev; 1164 1165 err = -EDESTADDRREQ; 1166 idev = __in6_dev_get(ndev); 1167 if (idev) { 1168 struct inet6_ifaddr *ifp; 1169 1170 read_lock_bh(&idev->lock); 1171 list_for_each_entry(ifp, &idev->addr_list, if_list) { 1172 if (ipv6_addr_type(&ifp->addr) & IPV6_ADDR_LINKLOCAL) 1173 continue; 1174 np->local_ip.in6 = ifp->addr; 1175 err = 0; 1176 break; 1177 } 1178 read_unlock_bh(&idev->lock); 1179 } 1180 if (err) { 1181 np_err(np, "no IPv6 address for %s, aborting\n", 1182 np->dev_name); 1183 goto put; 1184 } else 1185 np_info(np, "local IPv6 %pI6c\n", &np->local_ip.in6); 1186 #else 1187 np_err(np, "IPv6 is not supported %s, aborting\n", 1188 np->dev_name); 1189 err = -EINVAL; 1190 goto put; 1191 #endif 1192 } 1193 } 1194 1195 /* fill up the skb queue */ 1196 refill_skbs(); 1197 1198 err = __netpoll_setup(np, ndev, GFP_KERNEL); 1199 if (err) 1200 goto put; 1201 1202 rtnl_unlock(); 1203 return 0; 1204 1205 put: 1206 dev_put(ndev); 1207 unlock: 1208 rtnl_unlock(); 1209 return err; 1210 } 1211 EXPORT_SYMBOL(netpoll_setup); 1212 1213 static int __init netpoll_init(void) 1214 { 1215 skb_queue_head_init(&skb_pool); 1216 return 0; 1217 } 1218 core_initcall(netpoll_init); 1219 1220 static void rcu_cleanup_netpoll_info(struct rcu_head *rcu_head) 1221 { 1222 struct netpoll_info *npinfo = 1223 container_of(rcu_head, struct netpoll_info, rcu); 1224 1225 skb_queue_purge(&npinfo->neigh_tx); 1226 skb_queue_purge(&npinfo->txq); 1227 1228 /* we can't call cancel_delayed_work_sync here, as we are in softirq */ 1229 cancel_delayed_work(&npinfo->tx_work); 1230 1231 /* clean after last, unfinished work */ 1232 __skb_queue_purge(&npinfo->txq); 1233 /* now cancel it again */ 1234 cancel_delayed_work(&npinfo->tx_work); 1235 kfree(npinfo); 1236 } 1237 1238 void __netpoll_cleanup(struct netpoll *np) 1239 { 1240 struct netpoll_info *npinfo; 1241 unsigned long flags; 1242 1243 /* rtnl_dereference would be preferable here but 1244 * rcu_cleanup_netpoll path can put us in here safely without 1245 * holding the rtnl, so plain rcu_dereference it is 1246 */ 1247 npinfo = rtnl_dereference(np->dev->npinfo); 1248 if (!npinfo) 1249 return; 1250 1251 if (!list_empty(&npinfo->rx_np)) { 1252 spin_lock_irqsave(&npinfo->rx_lock, flags); 1253 list_del(&np->rx); 1254 if (list_empty(&npinfo->rx_np)) 1255 npinfo->rx_flags &= ~NETPOLL_RX_ENABLED; 1256 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 1257 } 1258 1259 synchronize_srcu(&netpoll_srcu); 1260 1261 if (atomic_dec_and_test(&npinfo->refcnt)) { 1262 const struct net_device_ops *ops; 1263 1264 ops = np->dev->netdev_ops; 1265 if (ops->ndo_netpoll_cleanup) 1266 ops->ndo_netpoll_cleanup(np->dev); 1267 1268 rcu_assign_pointer(np->dev->npinfo, NULL); 1269 call_rcu_bh(&npinfo->rcu, rcu_cleanup_netpoll_info); 1270 } 1271 } 1272 EXPORT_SYMBOL_GPL(__netpoll_cleanup); 1273 1274 static void netpoll_async_cleanup(struct work_struct *work) 1275 { 1276 struct netpoll *np = container_of(work, struct netpoll, cleanup_work); 1277 1278 rtnl_lock(); 1279 __netpoll_cleanup(np); 1280 rtnl_unlock(); 1281 kfree(np); 1282 } 1283 1284 void __netpoll_free_async(struct netpoll *np) 1285 { 1286 schedule_work(&np->cleanup_work); 1287 } 1288 EXPORT_SYMBOL_GPL(__netpoll_free_async); 1289 1290 void netpoll_cleanup(struct netpoll *np) 1291 { 1292 rtnl_lock(); 1293 if (!np->dev) 1294 goto out; 1295 __netpoll_cleanup(np); 1296 dev_put(np->dev); 1297 np->dev = NULL; 1298 out: 1299 rtnl_unlock(); 1300 } 1301 EXPORT_SYMBOL(netpoll_cleanup); 1302 1303 int netpoll_trap(void) 1304 { 1305 return atomic_read(&trapped); 1306 } 1307 EXPORT_SYMBOL(netpoll_trap); 1308 1309 void netpoll_set_trap(int trap) 1310 { 1311 if (trap) 1312 atomic_inc(&trapped); 1313 else 1314 atomic_dec(&trapped); 1315 } 1316 EXPORT_SYMBOL(netpoll_set_trap); 1317