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_hooks for the same address, 640 we're fine by sending a single reply */ 641 break; 642 } 643 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 644 } else if( proto == ETH_P_IPV6) { 645 #if IS_ENABLED(CONFIG_IPV6) 646 struct nd_msg *msg; 647 u8 *lladdr = NULL; 648 struct ipv6hdr *hdr; 649 struct icmp6hdr *icmp6h; 650 const struct in6_addr *saddr; 651 const struct in6_addr *daddr; 652 struct inet6_dev *in6_dev = NULL; 653 struct in6_addr *target; 654 655 in6_dev = in6_dev_get(skb->dev); 656 if (!in6_dev || !in6_dev->cnf.accept_ra) 657 return; 658 659 if (!pskb_may_pull(skb, skb->len)) 660 return; 661 662 msg = (struct nd_msg *)skb_transport_header(skb); 663 664 __skb_push(skb, skb->data - skb_transport_header(skb)); 665 666 if (ipv6_hdr(skb)->hop_limit != 255) 667 return; 668 if (msg->icmph.icmp6_code != 0) 669 return; 670 if (msg->icmph.icmp6_type != NDISC_NEIGHBOUR_SOLICITATION) 671 return; 672 673 saddr = &ipv6_hdr(skb)->saddr; 674 daddr = &ipv6_hdr(skb)->daddr; 675 676 size = sizeof(struct icmp6hdr) + sizeof(struct in6_addr); 677 678 spin_lock_irqsave(&npinfo->rx_lock, flags); 679 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) { 680 if (!ipv6_addr_equal(daddr, &np->local_ip.in6)) 681 continue; 682 683 hlen = LL_RESERVED_SPACE(np->dev); 684 tlen = np->dev->needed_tailroom; 685 send_skb = find_skb(np, size + hlen + tlen, hlen); 686 if (!send_skb) 687 continue; 688 689 send_skb->protocol = htons(ETH_P_IPV6); 690 send_skb->dev = skb->dev; 691 692 skb_reset_network_header(send_skb); 693 hdr = (struct ipv6hdr *) skb_put(send_skb, sizeof(struct ipv6hdr)); 694 *(__be32*)hdr = htonl(0x60000000); 695 hdr->payload_len = htons(size); 696 hdr->nexthdr = IPPROTO_ICMPV6; 697 hdr->hop_limit = 255; 698 hdr->saddr = *saddr; 699 hdr->daddr = *daddr; 700 701 icmp6h = (struct icmp6hdr *) skb_put(send_skb, sizeof(struct icmp6hdr)); 702 icmp6h->icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT; 703 icmp6h->icmp6_router = 0; 704 icmp6h->icmp6_solicited = 1; 705 706 target = (struct in6_addr *) skb_put(send_skb, sizeof(struct in6_addr)); 707 *target = msg->target; 708 icmp6h->icmp6_cksum = csum_ipv6_magic(saddr, daddr, size, 709 IPPROTO_ICMPV6, 710 csum_partial(icmp6h, 711 size, 0)); 712 713 if (dev_hard_header(send_skb, skb->dev, ETH_P_IPV6, 714 lladdr, np->dev->dev_addr, 715 send_skb->len) < 0) { 716 kfree_skb(send_skb); 717 continue; 718 } 719 720 netpoll_send_skb(np, send_skb); 721 722 /* If there are several rx_hooks for the same address, 723 we're fine by sending a single reply */ 724 break; 725 } 726 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 727 #endif 728 } 729 } 730 731 static bool pkt_is_ns(struct sk_buff *skb) 732 { 733 struct nd_msg *msg; 734 struct ipv6hdr *hdr; 735 736 if (skb->protocol != htons(ETH_P_ARP)) 737 return false; 738 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr) + sizeof(struct nd_msg))) 739 return false; 740 741 msg = (struct nd_msg *)skb_transport_header(skb); 742 __skb_push(skb, skb->data - skb_transport_header(skb)); 743 hdr = ipv6_hdr(skb); 744 745 if (hdr->nexthdr != IPPROTO_ICMPV6) 746 return false; 747 if (hdr->hop_limit != 255) 748 return false; 749 if (msg->icmph.icmp6_code != 0) 750 return false; 751 if (msg->icmph.icmp6_type != NDISC_NEIGHBOUR_SOLICITATION) 752 return false; 753 754 return true; 755 } 756 757 int __netpoll_rx(struct sk_buff *skb, struct netpoll_info *npinfo) 758 { 759 int proto, len, ulen; 760 int hits = 0; 761 const struct iphdr *iph; 762 struct udphdr *uh; 763 struct netpoll *np, *tmp; 764 765 if (list_empty(&npinfo->rx_np)) 766 goto out; 767 768 if (skb->dev->type != ARPHRD_ETHER) 769 goto out; 770 771 /* check if netpoll clients need ARP */ 772 if (skb->protocol == htons(ETH_P_ARP) && atomic_read(&trapped)) { 773 skb_queue_tail(&npinfo->neigh_tx, skb); 774 return 1; 775 } else if (pkt_is_ns(skb) && atomic_read(&trapped)) { 776 skb_queue_tail(&npinfo->neigh_tx, skb); 777 return 1; 778 } 779 780 if (skb->protocol == cpu_to_be16(ETH_P_8021Q)) { 781 skb = vlan_untag(skb); 782 if (unlikely(!skb)) 783 goto out; 784 } 785 786 proto = ntohs(eth_hdr(skb)->h_proto); 787 if (proto != ETH_P_IP && proto != ETH_P_IPV6) 788 goto out; 789 if (skb->pkt_type == PACKET_OTHERHOST) 790 goto out; 791 if (skb_shared(skb)) 792 goto out; 793 794 if (proto == ETH_P_IP) { 795 if (!pskb_may_pull(skb, sizeof(struct iphdr))) 796 goto out; 797 iph = (struct iphdr *)skb->data; 798 if (iph->ihl < 5 || iph->version != 4) 799 goto out; 800 if (!pskb_may_pull(skb, iph->ihl*4)) 801 goto out; 802 iph = (struct iphdr *)skb->data; 803 if (ip_fast_csum((u8 *)iph, iph->ihl) != 0) 804 goto out; 805 806 len = ntohs(iph->tot_len); 807 if (skb->len < len || len < iph->ihl*4) 808 goto out; 809 810 /* 811 * Our transport medium may have padded the buffer out. 812 * Now We trim to the true length of the frame. 813 */ 814 if (pskb_trim_rcsum(skb, len)) 815 goto out; 816 817 iph = (struct iphdr *)skb->data; 818 if (iph->protocol != IPPROTO_UDP) 819 goto out; 820 821 len -= iph->ihl*4; 822 uh = (struct udphdr *)(((char *)iph) + iph->ihl*4); 823 ulen = ntohs(uh->len); 824 825 if (ulen != len) 826 goto out; 827 if (checksum_udp(skb, uh, ulen, iph->saddr, iph->daddr)) 828 goto out; 829 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) { 830 if (np->local_ip.ip && np->local_ip.ip != iph->daddr) 831 continue; 832 if (np->remote_ip.ip && np->remote_ip.ip != iph->saddr) 833 continue; 834 if (np->local_port && np->local_port != ntohs(uh->dest)) 835 continue; 836 837 np->rx_hook(np, ntohs(uh->source), 838 (char *)(uh+1), 839 ulen - sizeof(struct udphdr)); 840 hits++; 841 } 842 } else { 843 #if IS_ENABLED(CONFIG_IPV6) 844 const struct ipv6hdr *ip6h; 845 846 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) 847 goto out; 848 ip6h = (struct ipv6hdr *)skb->data; 849 if (ip6h->version != 6) 850 goto out; 851 len = ntohs(ip6h->payload_len); 852 if (!len) 853 goto out; 854 if (len + sizeof(struct ipv6hdr) > skb->len) 855 goto out; 856 if (pskb_trim_rcsum(skb, len + sizeof(struct ipv6hdr))) 857 goto out; 858 ip6h = ipv6_hdr(skb); 859 if (!pskb_may_pull(skb, sizeof(struct udphdr))) 860 goto out; 861 uh = udp_hdr(skb); 862 ulen = ntohs(uh->len); 863 if (ulen != skb->len) 864 goto out; 865 if (udp6_csum_init(skb, uh, IPPROTO_UDP)) 866 goto out; 867 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) { 868 if (!ipv6_addr_equal(&np->local_ip.in6, &ip6h->daddr)) 869 continue; 870 if (!ipv6_addr_equal(&np->remote_ip.in6, &ip6h->saddr)) 871 continue; 872 if (np->local_port && np->local_port != ntohs(uh->dest)) 873 continue; 874 875 np->rx_hook(np, ntohs(uh->source), 876 (char *)(uh+1), 877 ulen - sizeof(struct udphdr)); 878 hits++; 879 } 880 #endif 881 } 882 883 if (!hits) 884 goto out; 885 886 kfree_skb(skb); 887 return 1; 888 889 out: 890 if (atomic_read(&trapped)) { 891 kfree_skb(skb); 892 return 1; 893 } 894 895 return 0; 896 } 897 898 void netpoll_print_options(struct netpoll *np) 899 { 900 np_info(np, "local port %d\n", np->local_port); 901 if (np->ipv6) 902 np_info(np, "local IPv6 address %pI6c\n", &np->local_ip.in6); 903 else 904 np_info(np, "local IPv4 address %pI4\n", &np->local_ip.ip); 905 np_info(np, "interface '%s'\n", np->dev_name); 906 np_info(np, "remote port %d\n", np->remote_port); 907 if (np->ipv6) 908 np_info(np, "remote IPv6 address %pI6c\n", &np->remote_ip.in6); 909 else 910 np_info(np, "remote IPv4 address %pI4\n", &np->remote_ip.ip); 911 np_info(np, "remote ethernet address %pM\n", np->remote_mac); 912 } 913 EXPORT_SYMBOL(netpoll_print_options); 914 915 static int netpoll_parse_ip_addr(const char *str, union inet_addr *addr) 916 { 917 const char *end; 918 919 if (!strchr(str, ':') && 920 in4_pton(str, -1, (void *)addr, -1, &end) > 0) { 921 if (!*end) 922 return 0; 923 } 924 if (in6_pton(str, -1, addr->in6.s6_addr, -1, &end) > 0) { 925 #if IS_ENABLED(CONFIG_IPV6) 926 if (!*end) 927 return 1; 928 #else 929 return -1; 930 #endif 931 } 932 return -1; 933 } 934 935 int netpoll_parse_options(struct netpoll *np, char *opt) 936 { 937 char *cur=opt, *delim; 938 int ipv6; 939 940 if (*cur != '@') { 941 if ((delim = strchr(cur, '@')) == NULL) 942 goto parse_failed; 943 *delim = 0; 944 if (kstrtou16(cur, 10, &np->local_port)) 945 goto parse_failed; 946 cur = delim; 947 } 948 cur++; 949 950 if (*cur != '/') { 951 if ((delim = strchr(cur, '/')) == NULL) 952 goto parse_failed; 953 *delim = 0; 954 ipv6 = netpoll_parse_ip_addr(cur, &np->local_ip); 955 if (ipv6 < 0) 956 goto parse_failed; 957 else 958 np->ipv6 = (bool)ipv6; 959 cur = delim; 960 } 961 cur++; 962 963 if (*cur != ',') { 964 /* parse out dev name */ 965 if ((delim = strchr(cur, ',')) == NULL) 966 goto parse_failed; 967 *delim = 0; 968 strlcpy(np->dev_name, cur, sizeof(np->dev_name)); 969 cur = delim; 970 } 971 cur++; 972 973 if (*cur != '@') { 974 /* dst port */ 975 if ((delim = strchr(cur, '@')) == NULL) 976 goto parse_failed; 977 *delim = 0; 978 if (*cur == ' ' || *cur == '\t') 979 np_info(np, "warning: whitespace is not allowed\n"); 980 if (kstrtou16(cur, 10, &np->remote_port)) 981 goto parse_failed; 982 cur = delim; 983 } 984 cur++; 985 986 /* dst ip */ 987 if ((delim = strchr(cur, '/')) == NULL) 988 goto parse_failed; 989 *delim = 0; 990 ipv6 = netpoll_parse_ip_addr(cur, &np->remote_ip); 991 if (ipv6 < 0) 992 goto parse_failed; 993 else if (np->ipv6 != (bool)ipv6) 994 goto parse_failed; 995 else 996 np->ipv6 = (bool)ipv6; 997 cur = delim + 1; 998 999 if (*cur != 0) { 1000 /* MAC address */ 1001 if (!mac_pton(cur, np->remote_mac)) 1002 goto parse_failed; 1003 } 1004 1005 netpoll_print_options(np); 1006 1007 return 0; 1008 1009 parse_failed: 1010 np_info(np, "couldn't parse config at '%s'!\n", cur); 1011 return -1; 1012 } 1013 EXPORT_SYMBOL(netpoll_parse_options); 1014 1015 int __netpoll_setup(struct netpoll *np, struct net_device *ndev, gfp_t gfp) 1016 { 1017 struct netpoll_info *npinfo; 1018 const struct net_device_ops *ops; 1019 unsigned long flags; 1020 int err; 1021 1022 np->dev = ndev; 1023 strlcpy(np->dev_name, ndev->name, IFNAMSIZ); 1024 INIT_WORK(&np->cleanup_work, netpoll_async_cleanup); 1025 1026 if ((ndev->priv_flags & IFF_DISABLE_NETPOLL) || 1027 !ndev->netdev_ops->ndo_poll_controller) { 1028 np_err(np, "%s doesn't support polling, aborting\n", 1029 np->dev_name); 1030 err = -ENOTSUPP; 1031 goto out; 1032 } 1033 1034 if (!ndev->npinfo) { 1035 npinfo = kmalloc(sizeof(*npinfo), gfp); 1036 if (!npinfo) { 1037 err = -ENOMEM; 1038 goto out; 1039 } 1040 1041 npinfo->rx_flags = 0; 1042 INIT_LIST_HEAD(&npinfo->rx_np); 1043 1044 spin_lock_init(&npinfo->rx_lock); 1045 sema_init(&npinfo->dev_lock, 1); 1046 skb_queue_head_init(&npinfo->neigh_tx); 1047 skb_queue_head_init(&npinfo->txq); 1048 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process); 1049 1050 atomic_set(&npinfo->refcnt, 1); 1051 1052 ops = np->dev->netdev_ops; 1053 if (ops->ndo_netpoll_setup) { 1054 err = ops->ndo_netpoll_setup(ndev, npinfo, gfp); 1055 if (err) 1056 goto free_npinfo; 1057 } 1058 } else { 1059 npinfo = rtnl_dereference(ndev->npinfo); 1060 atomic_inc(&npinfo->refcnt); 1061 } 1062 1063 npinfo->netpoll = np; 1064 1065 if (np->rx_hook) { 1066 spin_lock_irqsave(&npinfo->rx_lock, flags); 1067 npinfo->rx_flags |= NETPOLL_RX_ENABLED; 1068 list_add_tail(&np->rx, &npinfo->rx_np); 1069 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 1070 } 1071 1072 /* last thing to do is link it to the net device structure */ 1073 rcu_assign_pointer(ndev->npinfo, npinfo); 1074 1075 return 0; 1076 1077 free_npinfo: 1078 kfree(npinfo); 1079 out: 1080 return err; 1081 } 1082 EXPORT_SYMBOL_GPL(__netpoll_setup); 1083 1084 int netpoll_setup(struct netpoll *np) 1085 { 1086 struct net_device *ndev = NULL; 1087 struct in_device *in_dev; 1088 int err; 1089 1090 rtnl_lock(); 1091 if (np->dev_name) { 1092 struct net *net = current->nsproxy->net_ns; 1093 ndev = __dev_get_by_name(net, np->dev_name); 1094 } 1095 if (!ndev) { 1096 np_err(np, "%s doesn't exist, aborting\n", np->dev_name); 1097 err = -ENODEV; 1098 goto unlock; 1099 } 1100 dev_hold(ndev); 1101 1102 if (netdev_master_upper_dev_get(ndev)) { 1103 np_err(np, "%s is a slave device, aborting\n", np->dev_name); 1104 err = -EBUSY; 1105 goto put; 1106 } 1107 1108 if (!netif_running(ndev)) { 1109 unsigned long atmost, atleast; 1110 1111 np_info(np, "device %s not up yet, forcing it\n", np->dev_name); 1112 1113 err = dev_open(ndev); 1114 1115 if (err) { 1116 np_err(np, "failed to open %s\n", ndev->name); 1117 goto put; 1118 } 1119 1120 rtnl_unlock(); 1121 atleast = jiffies + HZ/10; 1122 atmost = jiffies + carrier_timeout * HZ; 1123 while (!netif_carrier_ok(ndev)) { 1124 if (time_after(jiffies, atmost)) { 1125 np_notice(np, "timeout waiting for carrier\n"); 1126 break; 1127 } 1128 msleep(1); 1129 } 1130 1131 /* If carrier appears to come up instantly, we don't 1132 * trust it and pause so that we don't pump all our 1133 * queued console messages into the bitbucket. 1134 */ 1135 1136 if (time_before(jiffies, atleast)) { 1137 np_notice(np, "carrier detect appears untrustworthy, waiting 4 seconds\n"); 1138 msleep(4000); 1139 } 1140 rtnl_lock(); 1141 } 1142 1143 if (!np->local_ip.ip) { 1144 if (!np->ipv6) { 1145 in_dev = __in_dev_get_rtnl(ndev); 1146 1147 if (!in_dev || !in_dev->ifa_list) { 1148 np_err(np, "no IP address for %s, aborting\n", 1149 np->dev_name); 1150 err = -EDESTADDRREQ; 1151 goto put; 1152 } 1153 1154 np->local_ip.ip = in_dev->ifa_list->ifa_local; 1155 np_info(np, "local IP %pI4\n", &np->local_ip.ip); 1156 } else { 1157 #if IS_ENABLED(CONFIG_IPV6) 1158 struct inet6_dev *idev; 1159 1160 err = -EDESTADDRREQ; 1161 idev = __in6_dev_get(ndev); 1162 if (idev) { 1163 struct inet6_ifaddr *ifp; 1164 1165 read_lock_bh(&idev->lock); 1166 list_for_each_entry(ifp, &idev->addr_list, if_list) { 1167 if (ipv6_addr_type(&ifp->addr) & IPV6_ADDR_LINKLOCAL) 1168 continue; 1169 np->local_ip.in6 = ifp->addr; 1170 err = 0; 1171 break; 1172 } 1173 read_unlock_bh(&idev->lock); 1174 } 1175 if (err) { 1176 np_err(np, "no IPv6 address for %s, aborting\n", 1177 np->dev_name); 1178 goto put; 1179 } else 1180 np_info(np, "local IPv6 %pI6c\n", &np->local_ip.in6); 1181 #else 1182 np_err(np, "IPv6 is not supported %s, aborting\n", 1183 np->dev_name); 1184 err = -EINVAL; 1185 goto put; 1186 #endif 1187 } 1188 } 1189 1190 /* fill up the skb queue */ 1191 refill_skbs(); 1192 1193 err = __netpoll_setup(np, ndev, GFP_KERNEL); 1194 if (err) 1195 goto put; 1196 1197 rtnl_unlock(); 1198 return 0; 1199 1200 put: 1201 dev_put(ndev); 1202 unlock: 1203 rtnl_unlock(); 1204 return err; 1205 } 1206 EXPORT_SYMBOL(netpoll_setup); 1207 1208 static int __init netpoll_init(void) 1209 { 1210 skb_queue_head_init(&skb_pool); 1211 return 0; 1212 } 1213 core_initcall(netpoll_init); 1214 1215 static void rcu_cleanup_netpoll_info(struct rcu_head *rcu_head) 1216 { 1217 struct netpoll_info *npinfo = 1218 container_of(rcu_head, struct netpoll_info, rcu); 1219 1220 skb_queue_purge(&npinfo->neigh_tx); 1221 skb_queue_purge(&npinfo->txq); 1222 1223 /* we can't call cancel_delayed_work_sync here, as we are in softirq */ 1224 cancel_delayed_work(&npinfo->tx_work); 1225 1226 /* clean after last, unfinished work */ 1227 __skb_queue_purge(&npinfo->txq); 1228 /* now cancel it again */ 1229 cancel_delayed_work(&npinfo->tx_work); 1230 kfree(npinfo); 1231 } 1232 1233 void __netpoll_cleanup(struct netpoll *np) 1234 { 1235 struct netpoll_info *npinfo; 1236 unsigned long flags; 1237 1238 /* rtnl_dereference would be preferable here but 1239 * rcu_cleanup_netpoll path can put us in here safely without 1240 * holding the rtnl, so plain rcu_dereference it is 1241 */ 1242 npinfo = rtnl_dereference(np->dev->npinfo); 1243 if (!npinfo) 1244 return; 1245 1246 if (!list_empty(&npinfo->rx_np)) { 1247 spin_lock_irqsave(&npinfo->rx_lock, flags); 1248 list_del(&np->rx); 1249 if (list_empty(&npinfo->rx_np)) 1250 npinfo->rx_flags &= ~NETPOLL_RX_ENABLED; 1251 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 1252 } 1253 1254 synchronize_srcu(&netpoll_srcu); 1255 1256 if (atomic_dec_and_test(&npinfo->refcnt)) { 1257 const struct net_device_ops *ops; 1258 1259 ops = np->dev->netdev_ops; 1260 if (ops->ndo_netpoll_cleanup) 1261 ops->ndo_netpoll_cleanup(np->dev); 1262 1263 rcu_assign_pointer(np->dev->npinfo, NULL); 1264 call_rcu_bh(&npinfo->rcu, rcu_cleanup_netpoll_info); 1265 } 1266 } 1267 EXPORT_SYMBOL_GPL(__netpoll_cleanup); 1268 1269 static void netpoll_async_cleanup(struct work_struct *work) 1270 { 1271 struct netpoll *np = container_of(work, struct netpoll, cleanup_work); 1272 1273 rtnl_lock(); 1274 __netpoll_cleanup(np); 1275 rtnl_unlock(); 1276 kfree(np); 1277 } 1278 1279 void __netpoll_free_async(struct netpoll *np) 1280 { 1281 schedule_work(&np->cleanup_work); 1282 } 1283 EXPORT_SYMBOL_GPL(__netpoll_free_async); 1284 1285 void netpoll_cleanup(struct netpoll *np) 1286 { 1287 rtnl_lock(); 1288 if (!np->dev) 1289 goto out; 1290 __netpoll_cleanup(np); 1291 dev_put(np->dev); 1292 np->dev = NULL; 1293 out: 1294 rtnl_unlock(); 1295 } 1296 EXPORT_SYMBOL(netpoll_cleanup); 1297 1298 int netpoll_trap(void) 1299 { 1300 return atomic_read(&trapped); 1301 } 1302 EXPORT_SYMBOL(netpoll_trap); 1303 1304 void netpoll_set_trap(int trap) 1305 { 1306 if (trap) 1307 atomic_inc(&trapped); 1308 else 1309 atomic_dec(&trapped); 1310 } 1311 EXPORT_SYMBOL(netpoll_set_trap); 1312