netpoll.c revision faeed828f9607923e9dc22182e819908e95c8852
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/netdevice.h> 16#include <linux/etherdevice.h> 17#include <linux/string.h> 18#include <linux/if_arp.h> 19#include <linux/inetdevice.h> 20#include <linux/inet.h> 21#include <linux/interrupt.h> 22#include <linux/netpoll.h> 23#include <linux/sched.h> 24#include <linux/delay.h> 25#include <linux/rcupdate.h> 26#include <linux/workqueue.h> 27#include <linux/slab.h> 28#include <linux/export.h> 29#include <linux/if_vlan.h> 30#include <net/tcp.h> 31#include <net/udp.h> 32#include <net/addrconf.h> 33#include <net/ndisc.h> 34#include <net/ip6_checksum.h> 35#include <asm/unaligned.h> 36#include <trace/events/napi.h> 37 38/* 39 * We maintain a small pool of fully-sized skbs, to make sure the 40 * message gets out even in extreme OOM situations. 41 */ 42 43#define MAX_UDP_CHUNK 1460 44#define MAX_SKBS 32 45 46static struct sk_buff_head skb_pool; 47 48static atomic_t trapped; 49 50#define USEC_PER_POLL 50 51#define NETPOLL_RX_ENABLED 1 52#define NETPOLL_RX_DROP 2 53 54#define MAX_SKB_SIZE \ 55 (sizeof(struct ethhdr) + \ 56 sizeof(struct iphdr) + \ 57 sizeof(struct udphdr) + \ 58 MAX_UDP_CHUNK) 59 60static void zap_completion_queue(void); 61static void netpoll_neigh_reply(struct sk_buff *skb, struct netpoll_info *npinfo); 62 63static unsigned int carrier_timeout = 4; 64module_param(carrier_timeout, uint, 0644); 65 66#define np_info(np, fmt, ...) \ 67 pr_info("%s: " fmt, np->name, ##__VA_ARGS__) 68#define np_err(np, fmt, ...) \ 69 pr_err("%s: " fmt, np->name, ##__VA_ARGS__) 70#define np_notice(np, fmt, ...) \ 71 pr_notice("%s: " fmt, np->name, ##__VA_ARGS__) 72 73static void queue_process(struct work_struct *work) 74{ 75 struct netpoll_info *npinfo = 76 container_of(work, struct netpoll_info, tx_work.work); 77 struct sk_buff *skb; 78 unsigned long flags; 79 80 while ((skb = skb_dequeue(&npinfo->txq))) { 81 struct net_device *dev = skb->dev; 82 const struct net_device_ops *ops = dev->netdev_ops; 83 struct netdev_queue *txq; 84 85 if (!netif_device_present(dev) || !netif_running(dev)) { 86 __kfree_skb(skb); 87 continue; 88 } 89 90 txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb)); 91 92 local_irq_save(flags); 93 __netif_tx_lock(txq, smp_processor_id()); 94 if (netif_xmit_frozen_or_stopped(txq) || 95 ops->ndo_start_xmit(skb, dev) != NETDEV_TX_OK) { 96 skb_queue_head(&npinfo->txq, skb); 97 __netif_tx_unlock(txq); 98 local_irq_restore(flags); 99 100 schedule_delayed_work(&npinfo->tx_work, HZ/10); 101 return; 102 } 103 __netif_tx_unlock(txq); 104 local_irq_restore(flags); 105 } 106} 107 108static __sum16 checksum_udp(struct sk_buff *skb, struct udphdr *uh, 109 unsigned short ulen, __be32 saddr, __be32 daddr) 110{ 111 __wsum psum; 112 113 if (uh->check == 0 || skb_csum_unnecessary(skb)) 114 return 0; 115 116 psum = csum_tcpudp_nofold(saddr, daddr, ulen, IPPROTO_UDP, 0); 117 118 if (skb->ip_summed == CHECKSUM_COMPLETE && 119 !csum_fold(csum_add(psum, skb->csum))) 120 return 0; 121 122 skb->csum = psum; 123 124 return __skb_checksum_complete(skb); 125} 126 127/* 128 * Check whether delayed processing was scheduled for our NIC. If so, 129 * we attempt to grab the poll lock and use ->poll() to pump the card. 130 * If this fails, either we've recursed in ->poll() or it's already 131 * running on another CPU. 132 * 133 * Note: we don't mask interrupts with this lock because we're using 134 * trylock here and interrupts are already disabled in the softirq 135 * case. Further, we test the poll_owner to avoid recursion on UP 136 * systems where the lock doesn't exist. 137 * 138 * In cases where there is bi-directional communications, reading only 139 * one message at a time can lead to packets being dropped by the 140 * network adapter, forcing superfluous retries and possibly timeouts. 141 * Thus, we set our budget to greater than 1. 142 */ 143static int poll_one_napi(struct netpoll_info *npinfo, 144 struct napi_struct *napi, int budget) 145{ 146 int work; 147 148 /* net_rx_action's ->poll() invocations and our's are 149 * synchronized by this test which is only made while 150 * holding the napi->poll_lock. 151 */ 152 if (!test_bit(NAPI_STATE_SCHED, &napi->state)) 153 return budget; 154 155 npinfo->rx_flags |= NETPOLL_RX_DROP; 156 atomic_inc(&trapped); 157 set_bit(NAPI_STATE_NPSVC, &napi->state); 158 159 work = napi->poll(napi, budget); 160 trace_napi_poll(napi); 161 162 clear_bit(NAPI_STATE_NPSVC, &napi->state); 163 atomic_dec(&trapped); 164 npinfo->rx_flags &= ~NETPOLL_RX_DROP; 165 166 return budget - work; 167} 168 169static void poll_napi(struct net_device *dev) 170{ 171 struct napi_struct *napi; 172 int budget = 16; 173 174 list_for_each_entry(napi, &dev->napi_list, dev_list) { 175 if (napi->poll_owner != smp_processor_id() && 176 spin_trylock(&napi->poll_lock)) { 177 budget = poll_one_napi(rcu_dereference_bh(dev->npinfo), 178 napi, budget); 179 spin_unlock(&napi->poll_lock); 180 181 if (!budget) 182 break; 183 } 184 } 185} 186 187static void service_neigh_queue(struct netpoll_info *npi) 188{ 189 if (npi) { 190 struct sk_buff *skb; 191 192 while ((skb = skb_dequeue(&npi->neigh_tx))) 193 netpoll_neigh_reply(skb, npi); 194 } 195} 196 197static void netpoll_poll_dev(struct net_device *dev) 198{ 199 const struct net_device_ops *ops; 200 struct netpoll_info *ni = rcu_dereference_bh(dev->npinfo); 201 202 if (!dev || !netif_running(dev)) 203 return; 204 205 ops = dev->netdev_ops; 206 if (!ops->ndo_poll_controller) 207 return; 208 209 /* Process pending work on NIC */ 210 ops->ndo_poll_controller(dev); 211 212 poll_napi(dev); 213 214 if (dev->flags & IFF_SLAVE) { 215 if (ni) { 216 struct net_device *bond_dev; 217 struct sk_buff *skb; 218 struct netpoll_info *bond_ni; 219 220 bond_dev = netdev_master_upper_dev_get_rcu(dev); 221 bond_ni = rcu_dereference_bh(bond_dev->npinfo); 222 while ((skb = skb_dequeue(&ni->neigh_tx))) { 223 skb->dev = bond_dev; 224 skb_queue_tail(&bond_ni->neigh_tx, skb); 225 } 226 } 227 } 228 229 service_neigh_queue(ni); 230 231 zap_completion_queue(); 232} 233 234static void refill_skbs(void) 235{ 236 struct sk_buff *skb; 237 unsigned long flags; 238 239 spin_lock_irqsave(&skb_pool.lock, flags); 240 while (skb_pool.qlen < MAX_SKBS) { 241 skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC); 242 if (!skb) 243 break; 244 245 __skb_queue_tail(&skb_pool, skb); 246 } 247 spin_unlock_irqrestore(&skb_pool.lock, flags); 248} 249 250static void zap_completion_queue(void) 251{ 252 unsigned long flags; 253 struct softnet_data *sd = &get_cpu_var(softnet_data); 254 255 if (sd->completion_queue) { 256 struct sk_buff *clist; 257 258 local_irq_save(flags); 259 clist = sd->completion_queue; 260 sd->completion_queue = NULL; 261 local_irq_restore(flags); 262 263 while (clist != NULL) { 264 struct sk_buff *skb = clist; 265 clist = clist->next; 266 if (skb->destructor) { 267 atomic_inc(&skb->users); 268 dev_kfree_skb_any(skb); /* put this one back */ 269 } else { 270 __kfree_skb(skb); 271 } 272 } 273 } 274 275 put_cpu_var(softnet_data); 276} 277 278static struct sk_buff *find_skb(struct netpoll *np, int len, int reserve) 279{ 280 int count = 0; 281 struct sk_buff *skb; 282 283 zap_completion_queue(); 284 refill_skbs(); 285repeat: 286 287 skb = alloc_skb(len, GFP_ATOMIC); 288 if (!skb) 289 skb = skb_dequeue(&skb_pool); 290 291 if (!skb) { 292 if (++count < 10) { 293 netpoll_poll_dev(np->dev); 294 goto repeat; 295 } 296 return NULL; 297 } 298 299 atomic_set(&skb->users, 1); 300 skb_reserve(skb, reserve); 301 return skb; 302} 303 304static int netpoll_owner_active(struct net_device *dev) 305{ 306 struct napi_struct *napi; 307 308 list_for_each_entry(napi, &dev->napi_list, dev_list) { 309 if (napi->poll_owner == smp_processor_id()) 310 return 1; 311 } 312 return 0; 313} 314 315/* call with IRQ disabled */ 316void netpoll_send_skb_on_dev(struct netpoll *np, struct sk_buff *skb, 317 struct net_device *dev) 318{ 319 int status = NETDEV_TX_BUSY; 320 unsigned long tries; 321 const struct net_device_ops *ops = dev->netdev_ops; 322 /* It is up to the caller to keep npinfo alive. */ 323 struct netpoll_info *npinfo; 324 325 WARN_ON_ONCE(!irqs_disabled()); 326 327 npinfo = rcu_dereference_bh(np->dev->npinfo); 328 if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) { 329 __kfree_skb(skb); 330 return; 331 } 332 333 /* don't get messages out of order, and no recursion */ 334 if (skb_queue_len(&npinfo->txq) == 0 && !netpoll_owner_active(dev)) { 335 struct netdev_queue *txq; 336 337 txq = netdev_pick_tx(dev, skb); 338 339 /* try until next clock tick */ 340 for (tries = jiffies_to_usecs(1)/USEC_PER_POLL; 341 tries > 0; --tries) { 342 if (__netif_tx_trylock(txq)) { 343 if (!netif_xmit_stopped(txq)) { 344 if (vlan_tx_tag_present(skb) && 345 !(netif_skb_features(skb) & NETIF_F_HW_VLAN_TX)) { 346 skb = __vlan_put_tag(skb, vlan_tx_tag_get(skb)); 347 if (unlikely(!skb)) 348 break; 349 skb->vlan_tci = 0; 350 } 351 352 status = ops->ndo_start_xmit(skb, dev); 353 if (status == NETDEV_TX_OK) 354 txq_trans_update(txq); 355 } 356 __netif_tx_unlock(txq); 357 358 if (status == NETDEV_TX_OK) 359 break; 360 361 } 362 363 /* tickle device maybe there is some cleanup */ 364 netpoll_poll_dev(np->dev); 365 366 udelay(USEC_PER_POLL); 367 } 368 369 WARN_ONCE(!irqs_disabled(), 370 "netpoll_send_skb_on_dev(): %s enabled interrupts in poll (%pF)\n", 371 dev->name, ops->ndo_start_xmit); 372 373 } 374 375 if (status != NETDEV_TX_OK) { 376 skb_queue_tail(&npinfo->txq, skb); 377 schedule_delayed_work(&npinfo->tx_work,0); 378 } 379} 380EXPORT_SYMBOL(netpoll_send_skb_on_dev); 381 382void netpoll_send_udp(struct netpoll *np, const char *msg, int len) 383{ 384 int total_len, ip_len, udp_len; 385 struct sk_buff *skb; 386 struct udphdr *udph; 387 struct iphdr *iph; 388 struct ethhdr *eth; 389 static atomic_t ip_ident; 390 struct ipv6hdr *ip6h; 391 392 udp_len = len + sizeof(*udph); 393 if (np->ipv6) 394 ip_len = udp_len + sizeof(*ip6h); 395 else 396 ip_len = udp_len + sizeof(*iph); 397 398 total_len = ip_len + LL_RESERVED_SPACE(np->dev); 399 400 skb = find_skb(np, total_len + np->dev->needed_tailroom, 401 total_len - len); 402 if (!skb) 403 return; 404 405 skb_copy_to_linear_data(skb, msg, len); 406 skb_put(skb, len); 407 408 skb_push(skb, sizeof(*udph)); 409 skb_reset_transport_header(skb); 410 udph = udp_hdr(skb); 411 udph->source = htons(np->local_port); 412 udph->dest = htons(np->remote_port); 413 udph->len = htons(udp_len); 414 415 if (np->ipv6) { 416 udph->check = 0; 417 udph->check = csum_ipv6_magic(&np->local_ip.in6, 418 &np->remote_ip.in6, 419 udp_len, IPPROTO_UDP, 420 csum_partial(udph, udp_len, 0)); 421 if (udph->check == 0) 422 udph->check = CSUM_MANGLED_0; 423 424 skb_push(skb, sizeof(*ip6h)); 425 skb_reset_network_header(skb); 426 ip6h = ipv6_hdr(skb); 427 428 /* ip6h->version = 6; ip6h->priority = 0; */ 429 put_unaligned(0x60, (unsigned char *)ip6h); 430 ip6h->flow_lbl[0] = 0; 431 ip6h->flow_lbl[1] = 0; 432 ip6h->flow_lbl[2] = 0; 433 434 ip6h->payload_len = htons(sizeof(struct udphdr) + len); 435 ip6h->nexthdr = IPPROTO_UDP; 436 ip6h->hop_limit = 32; 437 ip6h->saddr = np->local_ip.in6; 438 ip6h->daddr = np->remote_ip.in6; 439 440 eth = (struct ethhdr *) skb_push(skb, ETH_HLEN); 441 skb_reset_mac_header(skb); 442 skb->protocol = eth->h_proto = htons(ETH_P_IPV6); 443 } else { 444 udph->check = 0; 445 udph->check = csum_tcpudp_magic(np->local_ip.ip, 446 np->remote_ip.ip, 447 udp_len, IPPROTO_UDP, 448 csum_partial(udph, udp_len, 0)); 449 if (udph->check == 0) 450 udph->check = CSUM_MANGLED_0; 451 452 skb_push(skb, sizeof(*iph)); 453 skb_reset_network_header(skb); 454 iph = ip_hdr(skb); 455 456 /* iph->version = 4; iph->ihl = 5; */ 457 put_unaligned(0x45, (unsigned char *)iph); 458 iph->tos = 0; 459 put_unaligned(htons(ip_len), &(iph->tot_len)); 460 iph->id = htons(atomic_inc_return(&ip_ident)); 461 iph->frag_off = 0; 462 iph->ttl = 64; 463 iph->protocol = IPPROTO_UDP; 464 iph->check = 0; 465 put_unaligned(np->local_ip.ip, &(iph->saddr)); 466 put_unaligned(np->remote_ip.ip, &(iph->daddr)); 467 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); 468 469 eth = (struct ethhdr *) skb_push(skb, ETH_HLEN); 470 skb_reset_mac_header(skb); 471 skb->protocol = eth->h_proto = htons(ETH_P_IP); 472 } 473 474 memcpy(eth->h_source, np->dev->dev_addr, ETH_ALEN); 475 memcpy(eth->h_dest, np->remote_mac, ETH_ALEN); 476 477 skb->dev = np->dev; 478 479 netpoll_send_skb(np, skb); 480} 481EXPORT_SYMBOL(netpoll_send_udp); 482 483static void netpoll_neigh_reply(struct sk_buff *skb, struct netpoll_info *npinfo) 484{ 485 int size, type = ARPOP_REPLY; 486 __be32 sip, tip; 487 unsigned char *sha; 488 struct sk_buff *send_skb; 489 struct netpoll *np, *tmp; 490 unsigned long flags; 491 int hlen, tlen; 492 int hits = 0, proto; 493 494 if (list_empty(&npinfo->rx_np)) 495 return; 496 497 /* Before checking the packet, we do some early 498 inspection whether this is interesting at all */ 499 spin_lock_irqsave(&npinfo->rx_lock, flags); 500 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) { 501 if (np->dev == skb->dev) 502 hits++; 503 } 504 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 505 506 /* No netpoll struct is using this dev */ 507 if (!hits) 508 return; 509 510 proto = ntohs(eth_hdr(skb)->h_proto); 511 if (proto == ETH_P_IP) { 512 struct arphdr *arp; 513 unsigned char *arp_ptr; 514 /* No arp on this interface */ 515 if (skb->dev->flags & IFF_NOARP) 516 return; 517 518 if (!pskb_may_pull(skb, arp_hdr_len(skb->dev))) 519 return; 520 521 skb_reset_network_header(skb); 522 skb_reset_transport_header(skb); 523 arp = arp_hdr(skb); 524 525 if ((arp->ar_hrd != htons(ARPHRD_ETHER) && 526 arp->ar_hrd != htons(ARPHRD_IEEE802)) || 527 arp->ar_pro != htons(ETH_P_IP) || 528 arp->ar_op != htons(ARPOP_REQUEST)) 529 return; 530 531 arp_ptr = (unsigned char *)(arp+1); 532 /* save the location of the src hw addr */ 533 sha = arp_ptr; 534 arp_ptr += skb->dev->addr_len; 535 memcpy(&sip, arp_ptr, 4); 536 arp_ptr += 4; 537 /* If we actually cared about dst hw addr, 538 it would get copied here */ 539 arp_ptr += skb->dev->addr_len; 540 memcpy(&tip, arp_ptr, 4); 541 542 /* Should we ignore arp? */ 543 if (ipv4_is_loopback(tip) || ipv4_is_multicast(tip)) 544 return; 545 546 size = arp_hdr_len(skb->dev); 547 548 spin_lock_irqsave(&npinfo->rx_lock, flags); 549 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) { 550 if (tip != np->local_ip.ip) 551 continue; 552 553 hlen = LL_RESERVED_SPACE(np->dev); 554 tlen = np->dev->needed_tailroom; 555 send_skb = find_skb(np, size + hlen + tlen, hlen); 556 if (!send_skb) 557 continue; 558 559 skb_reset_network_header(send_skb); 560 arp = (struct arphdr *) skb_put(send_skb, size); 561 send_skb->dev = skb->dev; 562 send_skb->protocol = htons(ETH_P_ARP); 563 564 /* Fill the device header for the ARP frame */ 565 if (dev_hard_header(send_skb, skb->dev, ETH_P_ARP, 566 sha, np->dev->dev_addr, 567 send_skb->len) < 0) { 568 kfree_skb(send_skb); 569 continue; 570 } 571 572 /* 573 * Fill out the arp protocol part. 574 * 575 * we only support ethernet device type, 576 * which (according to RFC 1390) should 577 * always equal 1 (Ethernet). 578 */ 579 580 arp->ar_hrd = htons(np->dev->type); 581 arp->ar_pro = htons(ETH_P_IP); 582 arp->ar_hln = np->dev->addr_len; 583 arp->ar_pln = 4; 584 arp->ar_op = htons(type); 585 586 arp_ptr = (unsigned char *)(arp + 1); 587 memcpy(arp_ptr, np->dev->dev_addr, np->dev->addr_len); 588 arp_ptr += np->dev->addr_len; 589 memcpy(arp_ptr, &tip, 4); 590 arp_ptr += 4; 591 memcpy(arp_ptr, sha, np->dev->addr_len); 592 arp_ptr += np->dev->addr_len; 593 memcpy(arp_ptr, &sip, 4); 594 595 netpoll_send_skb(np, send_skb); 596 597 /* If there are several rx_hooks for the same address, 598 we're fine by sending a single reply */ 599 break; 600 } 601 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 602 } else if( proto == ETH_P_IPV6) { 603#if IS_ENABLED(CONFIG_IPV6) 604 struct nd_msg *msg; 605 u8 *lladdr = NULL; 606 struct ipv6hdr *hdr; 607 struct icmp6hdr *icmp6h; 608 const struct in6_addr *saddr; 609 const struct in6_addr *daddr; 610 struct inet6_dev *in6_dev = NULL; 611 struct in6_addr *target; 612 613 in6_dev = in6_dev_get(skb->dev); 614 if (!in6_dev || !in6_dev->cnf.accept_ra) 615 return; 616 617 if (!pskb_may_pull(skb, skb->len)) 618 return; 619 620 msg = (struct nd_msg *)skb_transport_header(skb); 621 622 __skb_push(skb, skb->data - skb_transport_header(skb)); 623 624 if (ipv6_hdr(skb)->hop_limit != 255) 625 return; 626 if (msg->icmph.icmp6_code != 0) 627 return; 628 if (msg->icmph.icmp6_type != NDISC_NEIGHBOUR_SOLICITATION) 629 return; 630 631 saddr = &ipv6_hdr(skb)->saddr; 632 daddr = &ipv6_hdr(skb)->daddr; 633 634 size = sizeof(struct icmp6hdr) + sizeof(struct in6_addr); 635 636 spin_lock_irqsave(&npinfo->rx_lock, flags); 637 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) { 638 if (!ipv6_addr_equal(daddr, &np->local_ip.in6)) 639 continue; 640 641 hlen = LL_RESERVED_SPACE(np->dev); 642 tlen = np->dev->needed_tailroom; 643 send_skb = find_skb(np, size + hlen + tlen, hlen); 644 if (!send_skb) 645 continue; 646 647 send_skb->protocol = htons(ETH_P_IPV6); 648 send_skb->dev = skb->dev; 649 650 skb_reset_network_header(send_skb); 651 skb_put(send_skb, sizeof(struct ipv6hdr)); 652 hdr = ipv6_hdr(send_skb); 653 654 *(__be32*)hdr = htonl(0x60000000); 655 656 hdr->payload_len = htons(size); 657 hdr->nexthdr = IPPROTO_ICMPV6; 658 hdr->hop_limit = 255; 659 hdr->saddr = *saddr; 660 hdr->daddr = *daddr; 661 662 send_skb->transport_header = send_skb->tail; 663 skb_put(send_skb, size); 664 665 icmp6h = (struct icmp6hdr *)skb_transport_header(skb); 666 icmp6h->icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT; 667 icmp6h->icmp6_router = 0; 668 icmp6h->icmp6_solicited = 1; 669 target = (struct in6_addr *)skb_transport_header(send_skb) + sizeof(struct icmp6hdr); 670 *target = msg->target; 671 icmp6h->icmp6_cksum = csum_ipv6_magic(saddr, daddr, size, 672 IPPROTO_ICMPV6, 673 csum_partial(icmp6h, 674 size, 0)); 675 676 if (dev_hard_header(send_skb, skb->dev, ETH_P_IPV6, 677 lladdr, np->dev->dev_addr, 678 send_skb->len) < 0) { 679 kfree_skb(send_skb); 680 continue; 681 } 682 683 netpoll_send_skb(np, send_skb); 684 685 /* If there are several rx_hooks for the same address, 686 we're fine by sending a single reply */ 687 break; 688 } 689 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 690#endif 691 } 692} 693 694static bool pkt_is_ns(struct sk_buff *skb) 695{ 696 struct nd_msg *msg; 697 struct ipv6hdr *hdr; 698 699 if (skb->protocol != htons(ETH_P_ARP)) 700 return false; 701 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr) + sizeof(struct nd_msg))) 702 return false; 703 704 msg = (struct nd_msg *)skb_transport_header(skb); 705 __skb_push(skb, skb->data - skb_transport_header(skb)); 706 hdr = ipv6_hdr(skb); 707 708 if (hdr->nexthdr != IPPROTO_ICMPV6) 709 return false; 710 if (hdr->hop_limit != 255) 711 return false; 712 if (msg->icmph.icmp6_code != 0) 713 return false; 714 if (msg->icmph.icmp6_type != NDISC_NEIGHBOUR_SOLICITATION) 715 return false; 716 717 return true; 718} 719 720int __netpoll_rx(struct sk_buff *skb, struct netpoll_info *npinfo) 721{ 722 int proto, len, ulen; 723 int hits = 0; 724 const struct iphdr *iph; 725 struct udphdr *uh; 726 struct netpoll *np, *tmp; 727 728 if (list_empty(&npinfo->rx_np)) 729 goto out; 730 731 if (skb->dev->type != ARPHRD_ETHER) 732 goto out; 733 734 /* check if netpoll clients need ARP */ 735 if (skb->protocol == htons(ETH_P_ARP) && atomic_read(&trapped)) { 736 skb_queue_tail(&npinfo->neigh_tx, skb); 737 return 1; 738 } else if (pkt_is_ns(skb) && atomic_read(&trapped)) { 739 skb_queue_tail(&npinfo->neigh_tx, skb); 740 return 1; 741 } 742 743 if (skb->protocol == cpu_to_be16(ETH_P_8021Q)) { 744 skb = vlan_untag(skb); 745 if (unlikely(!skb)) 746 goto out; 747 } 748 749 proto = ntohs(eth_hdr(skb)->h_proto); 750 if (proto != ETH_P_IP && proto != ETH_P_IPV6) 751 goto out; 752 if (skb->pkt_type == PACKET_OTHERHOST) 753 goto out; 754 if (skb_shared(skb)) 755 goto out; 756 757 if (proto == ETH_P_IP) { 758 if (!pskb_may_pull(skb, sizeof(struct iphdr))) 759 goto out; 760 iph = (struct iphdr *)skb->data; 761 if (iph->ihl < 5 || iph->version != 4) 762 goto out; 763 if (!pskb_may_pull(skb, iph->ihl*4)) 764 goto out; 765 iph = (struct iphdr *)skb->data; 766 if (ip_fast_csum((u8 *)iph, iph->ihl) != 0) 767 goto out; 768 769 len = ntohs(iph->tot_len); 770 if (skb->len < len || len < iph->ihl*4) 771 goto out; 772 773 /* 774 * Our transport medium may have padded the buffer out. 775 * Now We trim to the true length of the frame. 776 */ 777 if (pskb_trim_rcsum(skb, len)) 778 goto out; 779 780 iph = (struct iphdr *)skb->data; 781 if (iph->protocol != IPPROTO_UDP) 782 goto out; 783 784 len -= iph->ihl*4; 785 uh = (struct udphdr *)(((char *)iph) + iph->ihl*4); 786 ulen = ntohs(uh->len); 787 788 if (ulen != len) 789 goto out; 790 if (checksum_udp(skb, uh, ulen, iph->saddr, iph->daddr)) 791 goto out; 792 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) { 793 if (np->local_ip.ip && np->local_ip.ip != iph->daddr) 794 continue; 795 if (np->remote_ip.ip && np->remote_ip.ip != iph->saddr) 796 continue; 797 if (np->local_port && np->local_port != ntohs(uh->dest)) 798 continue; 799 800 np->rx_hook(np, ntohs(uh->source), 801 (char *)(uh+1), 802 ulen - sizeof(struct udphdr)); 803 hits++; 804 } 805 } else { 806#if IS_ENABLED(CONFIG_IPV6) 807 const struct ipv6hdr *ip6h; 808 809 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) 810 goto out; 811 ip6h = (struct ipv6hdr *)skb->data; 812 if (ip6h->version != 6) 813 goto out; 814 len = ntohs(ip6h->payload_len); 815 if (!len) 816 goto out; 817 if (len + sizeof(struct ipv6hdr) > skb->len) 818 goto out; 819 if (pskb_trim_rcsum(skb, len + sizeof(struct ipv6hdr))) 820 goto out; 821 ip6h = ipv6_hdr(skb); 822 if (!pskb_may_pull(skb, sizeof(struct udphdr))) 823 goto out; 824 uh = udp_hdr(skb); 825 ulen = ntohs(uh->len); 826 if (ulen != skb->len) 827 goto out; 828 if (udp6_csum_init(skb, uh, IPPROTO_UDP)) 829 goto out; 830 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) { 831 if (!ipv6_addr_equal(&np->local_ip.in6, &ip6h->daddr)) 832 continue; 833 if (!ipv6_addr_equal(&np->remote_ip.in6, &ip6h->saddr)) 834 continue; 835 if (np->local_port && np->local_port != ntohs(uh->dest)) 836 continue; 837 838 np->rx_hook(np, ntohs(uh->source), 839 (char *)(uh+1), 840 ulen - sizeof(struct udphdr)); 841 hits++; 842 } 843#endif 844 } 845 846 if (!hits) 847 goto out; 848 849 kfree_skb(skb); 850 return 1; 851 852out: 853 if (atomic_read(&trapped)) { 854 kfree_skb(skb); 855 return 1; 856 } 857 858 return 0; 859} 860 861void netpoll_print_options(struct netpoll *np) 862{ 863 np_info(np, "local port %d\n", np->local_port); 864 if (np->ipv6) 865 np_info(np, "local IPv6 address %pI6c\n", &np->local_ip.in6); 866 else 867 np_info(np, "local IPv4 address %pI4\n", &np->local_ip.ip); 868 np_info(np, "interface '%s'\n", np->dev_name); 869 np_info(np, "remote port %d\n", np->remote_port); 870 if (np->ipv6) 871 np_info(np, "remote IPv6 address %pI6c\n", &np->remote_ip.in6); 872 else 873 np_info(np, "remote IPv4 address %pI4\n", &np->remote_ip.ip); 874 np_info(np, "remote ethernet address %pM\n", np->remote_mac); 875} 876EXPORT_SYMBOL(netpoll_print_options); 877 878static int netpoll_parse_ip_addr(const char *str, union inet_addr *addr) 879{ 880 const char *end; 881 882 if (!strchr(str, ':') && 883 in4_pton(str, -1, (void *)addr, -1, &end) > 0) { 884 if (!*end) 885 return 0; 886 } 887 if (in6_pton(str, -1, addr->in6.s6_addr, -1, &end) > 0) { 888#if IS_ENABLED(CONFIG_IPV6) 889 if (!*end) 890 return 1; 891#else 892 return -1; 893#endif 894 } 895 return -1; 896} 897 898int netpoll_parse_options(struct netpoll *np, char *opt) 899{ 900 char *cur=opt, *delim; 901 int ipv6; 902 903 if (*cur != '@') { 904 if ((delim = strchr(cur, '@')) == NULL) 905 goto parse_failed; 906 *delim = 0; 907 if (kstrtou16(cur, 10, &np->local_port)) 908 goto parse_failed; 909 cur = delim; 910 } 911 cur++; 912 913 if (*cur != '/') { 914 if ((delim = strchr(cur, '/')) == NULL) 915 goto parse_failed; 916 *delim = 0; 917 ipv6 = netpoll_parse_ip_addr(cur, &np->local_ip); 918 if (ipv6 < 0) 919 goto parse_failed; 920 else 921 np->ipv6 = (bool)ipv6; 922 cur = delim; 923 } 924 cur++; 925 926 if (*cur != ',') { 927 /* parse out dev name */ 928 if ((delim = strchr(cur, ',')) == NULL) 929 goto parse_failed; 930 *delim = 0; 931 strlcpy(np->dev_name, cur, sizeof(np->dev_name)); 932 cur = delim; 933 } 934 cur++; 935 936 if (*cur != '@') { 937 /* dst port */ 938 if ((delim = strchr(cur, '@')) == NULL) 939 goto parse_failed; 940 *delim = 0; 941 if (*cur == ' ' || *cur == '\t') 942 np_info(np, "warning: whitespace is not allowed\n"); 943 if (kstrtou16(cur, 10, &np->remote_port)) 944 goto parse_failed; 945 cur = delim; 946 } 947 cur++; 948 949 /* dst ip */ 950 if ((delim = strchr(cur, '/')) == NULL) 951 goto parse_failed; 952 *delim = 0; 953 ipv6 = netpoll_parse_ip_addr(cur, &np->remote_ip); 954 if (ipv6 < 0) 955 goto parse_failed; 956 else if (np->ipv6 != (bool)ipv6) 957 goto parse_failed; 958 else 959 np->ipv6 = (bool)ipv6; 960 cur = delim + 1; 961 962 if (*cur != 0) { 963 /* MAC address */ 964 if (!mac_pton(cur, np->remote_mac)) 965 goto parse_failed; 966 } 967 968 netpoll_print_options(np); 969 970 return 0; 971 972 parse_failed: 973 np_info(np, "couldn't parse config at '%s'!\n", cur); 974 return -1; 975} 976EXPORT_SYMBOL(netpoll_parse_options); 977 978int __netpoll_setup(struct netpoll *np, struct net_device *ndev, gfp_t gfp) 979{ 980 struct netpoll_info *npinfo; 981 const struct net_device_ops *ops; 982 unsigned long flags; 983 int err; 984 985 np->dev = ndev; 986 strlcpy(np->dev_name, ndev->name, IFNAMSIZ); 987 988 if ((ndev->priv_flags & IFF_DISABLE_NETPOLL) || 989 !ndev->netdev_ops->ndo_poll_controller) { 990 np_err(np, "%s doesn't support polling, aborting\n", 991 np->dev_name); 992 err = -ENOTSUPP; 993 goto out; 994 } 995 996 if (!ndev->npinfo) { 997 npinfo = kmalloc(sizeof(*npinfo), gfp); 998 if (!npinfo) { 999 err = -ENOMEM; 1000 goto out; 1001 } 1002 1003 npinfo->rx_flags = 0; 1004 INIT_LIST_HEAD(&npinfo->rx_np); 1005 1006 spin_lock_init(&npinfo->rx_lock); 1007 skb_queue_head_init(&npinfo->neigh_tx); 1008 skb_queue_head_init(&npinfo->txq); 1009 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process); 1010 1011 atomic_set(&npinfo->refcnt, 1); 1012 1013 ops = np->dev->netdev_ops; 1014 if (ops->ndo_netpoll_setup) { 1015 err = ops->ndo_netpoll_setup(ndev, npinfo, gfp); 1016 if (err) 1017 goto free_npinfo; 1018 } 1019 } else { 1020 npinfo = ndev->npinfo; 1021 atomic_inc(&npinfo->refcnt); 1022 } 1023 1024 npinfo->netpoll = np; 1025 1026 if (np->rx_hook) { 1027 spin_lock_irqsave(&npinfo->rx_lock, flags); 1028 npinfo->rx_flags |= NETPOLL_RX_ENABLED; 1029 list_add_tail(&np->rx, &npinfo->rx_np); 1030 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 1031 } 1032 1033 /* last thing to do is link it to the net device structure */ 1034 rcu_assign_pointer(ndev->npinfo, npinfo); 1035 1036 return 0; 1037 1038free_npinfo: 1039 kfree(npinfo); 1040out: 1041 return err; 1042} 1043EXPORT_SYMBOL_GPL(__netpoll_setup); 1044 1045int netpoll_setup(struct netpoll *np) 1046{ 1047 struct net_device *ndev = NULL; 1048 struct in_device *in_dev; 1049 int err; 1050 1051 rtnl_lock(); 1052 if (np->dev_name) 1053 ndev = __dev_get_by_name(&init_net, np->dev_name); 1054 if (!ndev) { 1055 np_err(np, "%s doesn't exist, aborting\n", np->dev_name); 1056 err = -ENODEV; 1057 goto unlock; 1058 } 1059 dev_hold(ndev); 1060 1061 if (netdev_master_upper_dev_get(ndev)) { 1062 np_err(np, "%s is a slave device, aborting\n", np->dev_name); 1063 err = -EBUSY; 1064 goto put; 1065 } 1066 1067 if (!netif_running(ndev)) { 1068 unsigned long atmost, atleast; 1069 1070 np_info(np, "device %s not up yet, forcing it\n", np->dev_name); 1071 1072 err = dev_open(ndev); 1073 1074 if (err) { 1075 np_err(np, "failed to open %s\n", ndev->name); 1076 goto put; 1077 } 1078 1079 rtnl_unlock(); 1080 atleast = jiffies + HZ/10; 1081 atmost = jiffies + carrier_timeout * HZ; 1082 while (!netif_carrier_ok(ndev)) { 1083 if (time_after(jiffies, atmost)) { 1084 np_notice(np, "timeout waiting for carrier\n"); 1085 break; 1086 } 1087 msleep(1); 1088 } 1089 1090 /* If carrier appears to come up instantly, we don't 1091 * trust it and pause so that we don't pump all our 1092 * queued console messages into the bitbucket. 1093 */ 1094 1095 if (time_before(jiffies, atleast)) { 1096 np_notice(np, "carrier detect appears untrustworthy, waiting 4 seconds\n"); 1097 msleep(4000); 1098 } 1099 rtnl_lock(); 1100 } 1101 1102 if (!np->local_ip.ip) { 1103 if (!np->ipv6) { 1104 in_dev = __in_dev_get_rtnl(ndev); 1105 1106 if (!in_dev || !in_dev->ifa_list) { 1107 np_err(np, "no IP address for %s, aborting\n", 1108 np->dev_name); 1109 err = -EDESTADDRREQ; 1110 goto put; 1111 } 1112 1113 np->local_ip.ip = in_dev->ifa_list->ifa_local; 1114 np_info(np, "local IP %pI4\n", &np->local_ip.ip); 1115 } else { 1116#if IS_ENABLED(CONFIG_IPV6) 1117 struct inet6_dev *idev; 1118 1119 err = -EDESTADDRREQ; 1120 idev = __in6_dev_get(ndev); 1121 if (idev) { 1122 struct inet6_ifaddr *ifp; 1123 1124 read_lock_bh(&idev->lock); 1125 list_for_each_entry(ifp, &idev->addr_list, if_list) { 1126 if (ipv6_addr_type(&ifp->addr) & IPV6_ADDR_LINKLOCAL) 1127 continue; 1128 np->local_ip.in6 = ifp->addr; 1129 err = 0; 1130 break; 1131 } 1132 read_unlock_bh(&idev->lock); 1133 } 1134 if (err) { 1135 np_err(np, "no IPv6 address for %s, aborting\n", 1136 np->dev_name); 1137 goto put; 1138 } else 1139 np_info(np, "local IPv6 %pI6c\n", &np->local_ip.in6); 1140#else 1141 np_err(np, "IPv6 is not supported %s, aborting\n", 1142 np->dev_name); 1143 err = -EINVAL; 1144 goto put; 1145#endif 1146 } 1147 } 1148 1149 /* fill up the skb queue */ 1150 refill_skbs(); 1151 1152 err = __netpoll_setup(np, ndev, GFP_KERNEL); 1153 if (err) 1154 goto put; 1155 1156 rtnl_unlock(); 1157 return 0; 1158 1159put: 1160 dev_put(ndev); 1161unlock: 1162 rtnl_unlock(); 1163 return err; 1164} 1165EXPORT_SYMBOL(netpoll_setup); 1166 1167static int __init netpoll_init(void) 1168{ 1169 skb_queue_head_init(&skb_pool); 1170 return 0; 1171} 1172core_initcall(netpoll_init); 1173 1174static void rcu_cleanup_netpoll_info(struct rcu_head *rcu_head) 1175{ 1176 struct netpoll_info *npinfo = 1177 container_of(rcu_head, struct netpoll_info, rcu); 1178 1179 skb_queue_purge(&npinfo->neigh_tx); 1180 skb_queue_purge(&npinfo->txq); 1181 1182 /* we can't call cancel_delayed_work_sync here, as we are in softirq */ 1183 cancel_delayed_work(&npinfo->tx_work); 1184 1185 /* clean after last, unfinished work */ 1186 __skb_queue_purge(&npinfo->txq); 1187 /* now cancel it again */ 1188 cancel_delayed_work(&npinfo->tx_work); 1189 kfree(npinfo); 1190} 1191 1192void __netpoll_cleanup(struct netpoll *np) 1193{ 1194 struct netpoll_info *npinfo; 1195 unsigned long flags; 1196 1197 npinfo = np->dev->npinfo; 1198 if (!npinfo) 1199 return; 1200 1201 if (!list_empty(&npinfo->rx_np)) { 1202 spin_lock_irqsave(&npinfo->rx_lock, flags); 1203 list_del(&np->rx); 1204 if (list_empty(&npinfo->rx_np)) 1205 npinfo->rx_flags &= ~NETPOLL_RX_ENABLED; 1206 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 1207 } 1208 1209 if (atomic_dec_and_test(&npinfo->refcnt)) { 1210 const struct net_device_ops *ops; 1211 1212 ops = np->dev->netdev_ops; 1213 if (ops->ndo_netpoll_cleanup) 1214 ops->ndo_netpoll_cleanup(np->dev); 1215 1216 RCU_INIT_POINTER(np->dev->npinfo, NULL); 1217 call_rcu_bh(&npinfo->rcu, rcu_cleanup_netpoll_info); 1218 } 1219} 1220EXPORT_SYMBOL_GPL(__netpoll_cleanup); 1221 1222static void rcu_cleanup_netpoll(struct rcu_head *rcu_head) 1223{ 1224 struct netpoll *np = container_of(rcu_head, struct netpoll, rcu); 1225 1226 __netpoll_cleanup(np); 1227 kfree(np); 1228} 1229 1230void __netpoll_free_rcu(struct netpoll *np) 1231{ 1232 call_rcu_bh(&np->rcu, rcu_cleanup_netpoll); 1233} 1234EXPORT_SYMBOL_GPL(__netpoll_free_rcu); 1235 1236void netpoll_cleanup(struct netpoll *np) 1237{ 1238 if (!np->dev) 1239 return; 1240 1241 rtnl_lock(); 1242 __netpoll_cleanup(np); 1243 rtnl_unlock(); 1244 1245 dev_put(np->dev); 1246 np->dev = NULL; 1247} 1248EXPORT_SYMBOL(netpoll_cleanup); 1249 1250int netpoll_trap(void) 1251{ 1252 return atomic_read(&trapped); 1253} 1254EXPORT_SYMBOL(netpoll_trap); 1255 1256void netpoll_set_trap(int trap) 1257{ 1258 if (trap) 1259 atomic_inc(&trapped); 1260 else 1261 atomic_dec(&trapped); 1262} 1263EXPORT_SYMBOL(netpoll_set_trap); 1264