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 #include <linux/moduleparam.h> 13 #include <linux/netdevice.h> 14 #include <linux/etherdevice.h> 15 #include <linux/string.h> 16 #include <linux/if_arp.h> 17 #include <linux/inetdevice.h> 18 #include <linux/inet.h> 19 #include <linux/interrupt.h> 20 #include <linux/netpoll.h> 21 #include <linux/sched.h> 22 #include <linux/delay.h> 23 #include <linux/rcupdate.h> 24 #include <linux/workqueue.h> 25 #include <linux/slab.h> 26 #include <linux/export.h> 27 #include <net/tcp.h> 28 #include <net/udp.h> 29 #include <asm/unaligned.h> 30 #include <trace/events/napi.h> 31 32 /* 33 * We maintain a small pool of fully-sized skbs, to make sure the 34 * message gets out even in extreme OOM situations. 35 */ 36 37 #define MAX_UDP_CHUNK 1460 38 #define MAX_SKBS 32 39 40 static struct sk_buff_head skb_pool; 41 42 static atomic_t trapped; 43 44 #define USEC_PER_POLL 50 45 #define NETPOLL_RX_ENABLED 1 46 #define NETPOLL_RX_DROP 2 47 48 #define MAX_SKB_SIZE \ 49 (MAX_UDP_CHUNK + sizeof(struct udphdr) + \ 50 sizeof(struct iphdr) + sizeof(struct ethhdr)) 51 52 static void zap_completion_queue(void); 53 static void arp_reply(struct sk_buff *skb); 54 55 static unsigned int carrier_timeout = 4; 56 module_param(carrier_timeout, uint, 0644); 57 58 static void queue_process(struct work_struct *work) 59 { 60 struct netpoll_info *npinfo = 61 container_of(work, struct netpoll_info, tx_work.work); 62 struct sk_buff *skb; 63 unsigned long flags; 64 65 while ((skb = skb_dequeue(&npinfo->txq))) { 66 struct net_device *dev = skb->dev; 67 const struct net_device_ops *ops = dev->netdev_ops; 68 struct netdev_queue *txq; 69 70 if (!netif_device_present(dev) || !netif_running(dev)) { 71 __kfree_skb(skb); 72 continue; 73 } 74 75 txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb)); 76 77 local_irq_save(flags); 78 __netif_tx_lock(txq, smp_processor_id()); 79 if (netif_xmit_frozen_or_stopped(txq) || 80 ops->ndo_start_xmit(skb, dev) != NETDEV_TX_OK) { 81 skb_queue_head(&npinfo->txq, skb); 82 __netif_tx_unlock(txq); 83 local_irq_restore(flags); 84 85 schedule_delayed_work(&npinfo->tx_work, HZ/10); 86 return; 87 } 88 __netif_tx_unlock(txq); 89 local_irq_restore(flags); 90 } 91 } 92 93 static __sum16 checksum_udp(struct sk_buff *skb, struct udphdr *uh, 94 unsigned short ulen, __be32 saddr, __be32 daddr) 95 { 96 __wsum psum; 97 98 if (uh->check == 0 || skb_csum_unnecessary(skb)) 99 return 0; 100 101 psum = csum_tcpudp_nofold(saddr, daddr, ulen, IPPROTO_UDP, 0); 102 103 if (skb->ip_summed == CHECKSUM_COMPLETE && 104 !csum_fold(csum_add(psum, skb->csum))) 105 return 0; 106 107 skb->csum = psum; 108 109 return __skb_checksum_complete(skb); 110 } 111 112 /* 113 * Check whether delayed processing was scheduled for our NIC. If so, 114 * we attempt to grab the poll lock and use ->poll() to pump the card. 115 * If this fails, either we've recursed in ->poll() or it's already 116 * running on another CPU. 117 * 118 * Note: we don't mask interrupts with this lock because we're using 119 * trylock here and interrupts are already disabled in the softirq 120 * case. Further, we test the poll_owner to avoid recursion on UP 121 * systems where the lock doesn't exist. 122 * 123 * In cases where there is bi-directional communications, reading only 124 * one message at a time can lead to packets being dropped by the 125 * network adapter, forcing superfluous retries and possibly timeouts. 126 * Thus, we set our budget to greater than 1. 127 */ 128 static int poll_one_napi(struct netpoll_info *npinfo, 129 struct napi_struct *napi, int budget) 130 { 131 int work; 132 133 /* net_rx_action's ->poll() invocations and our's are 134 * synchronized by this test which is only made while 135 * holding the napi->poll_lock. 136 */ 137 if (!test_bit(NAPI_STATE_SCHED, &napi->state)) 138 return budget; 139 140 npinfo->rx_flags |= NETPOLL_RX_DROP; 141 atomic_inc(&trapped); 142 set_bit(NAPI_STATE_NPSVC, &napi->state); 143 144 work = napi->poll(napi, budget); 145 trace_napi_poll(napi); 146 147 clear_bit(NAPI_STATE_NPSVC, &napi->state); 148 atomic_dec(&trapped); 149 npinfo->rx_flags &= ~NETPOLL_RX_DROP; 150 151 return budget - work; 152 } 153 154 static void poll_napi(struct net_device *dev) 155 { 156 struct napi_struct *napi; 157 int budget = 16; 158 159 list_for_each_entry(napi, &dev->napi_list, dev_list) { 160 if (napi->poll_owner != smp_processor_id() && 161 spin_trylock(&napi->poll_lock)) { 162 budget = poll_one_napi(dev->npinfo, napi, budget); 163 spin_unlock(&napi->poll_lock); 164 165 if (!budget) 166 break; 167 } 168 } 169 } 170 171 static void service_arp_queue(struct netpoll_info *npi) 172 { 173 if (npi) { 174 struct sk_buff *skb; 175 176 while ((skb = skb_dequeue(&npi->arp_tx))) 177 arp_reply(skb); 178 } 179 } 180 181 static void netpoll_poll_dev(struct net_device *dev) 182 { 183 const struct net_device_ops *ops; 184 185 if (!dev || !netif_running(dev)) 186 return; 187 188 ops = dev->netdev_ops; 189 if (!ops->ndo_poll_controller) 190 return; 191 192 /* Process pending work on NIC */ 193 ops->ndo_poll_controller(dev); 194 195 poll_napi(dev); 196 197 if (dev->priv_flags & IFF_SLAVE) { 198 if (dev->npinfo) { 199 struct net_device *bond_dev = dev->master; 200 struct sk_buff *skb; 201 while ((skb = skb_dequeue(&dev->npinfo->arp_tx))) { 202 skb->dev = bond_dev; 203 skb_queue_tail(&bond_dev->npinfo->arp_tx, skb); 204 } 205 } 206 } 207 208 service_arp_queue(dev->npinfo); 209 210 zap_completion_queue(); 211 } 212 213 static void refill_skbs(void) 214 { 215 struct sk_buff *skb; 216 unsigned long flags; 217 218 spin_lock_irqsave(&skb_pool.lock, flags); 219 while (skb_pool.qlen < MAX_SKBS) { 220 skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC); 221 if (!skb) 222 break; 223 224 __skb_queue_tail(&skb_pool, skb); 225 } 226 spin_unlock_irqrestore(&skb_pool.lock, flags); 227 } 228 229 static void zap_completion_queue(void) 230 { 231 unsigned long flags; 232 struct softnet_data *sd = &get_cpu_var(softnet_data); 233 234 if (sd->completion_queue) { 235 struct sk_buff *clist; 236 237 local_irq_save(flags); 238 clist = sd->completion_queue; 239 sd->completion_queue = NULL; 240 local_irq_restore(flags); 241 242 while (clist != NULL) { 243 struct sk_buff *skb = clist; 244 clist = clist->next; 245 if (skb->destructor) { 246 atomic_inc(&skb->users); 247 dev_kfree_skb_any(skb); /* put this one back */ 248 } else { 249 __kfree_skb(skb); 250 } 251 } 252 } 253 254 put_cpu_var(softnet_data); 255 } 256 257 static struct sk_buff *find_skb(struct netpoll *np, int len, int reserve) 258 { 259 int count = 0; 260 struct sk_buff *skb; 261 262 zap_completion_queue(); 263 refill_skbs(); 264 repeat: 265 266 skb = alloc_skb(len, GFP_ATOMIC); 267 if (!skb) 268 skb = skb_dequeue(&skb_pool); 269 270 if (!skb) { 271 if (++count < 10) { 272 netpoll_poll_dev(np->dev); 273 goto repeat; 274 } 275 return NULL; 276 } 277 278 atomic_set(&skb->users, 1); 279 skb_reserve(skb, reserve); 280 return skb; 281 } 282 283 static int netpoll_owner_active(struct net_device *dev) 284 { 285 struct napi_struct *napi; 286 287 list_for_each_entry(napi, &dev->napi_list, dev_list) { 288 if (napi->poll_owner == smp_processor_id()) 289 return 1; 290 } 291 return 0; 292 } 293 294 void netpoll_send_skb_on_dev(struct netpoll *np, struct sk_buff *skb, 295 struct net_device *dev) 296 { 297 int status = NETDEV_TX_BUSY; 298 unsigned long tries; 299 const struct net_device_ops *ops = dev->netdev_ops; 300 /* It is up to the caller to keep npinfo alive. */ 301 struct netpoll_info *npinfo = np->dev->npinfo; 302 303 if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) { 304 __kfree_skb(skb); 305 return; 306 } 307 308 /* don't get messages out of order, and no recursion */ 309 if (skb_queue_len(&npinfo->txq) == 0 && !netpoll_owner_active(dev)) { 310 struct netdev_queue *txq; 311 unsigned long flags; 312 313 txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb)); 314 315 local_irq_save(flags); 316 /* try until next clock tick */ 317 for (tries = jiffies_to_usecs(1)/USEC_PER_POLL; 318 tries > 0; --tries) { 319 if (__netif_tx_trylock(txq)) { 320 if (!netif_xmit_stopped(txq)) { 321 status = ops->ndo_start_xmit(skb, dev); 322 if (status == NETDEV_TX_OK) 323 txq_trans_update(txq); 324 } 325 __netif_tx_unlock(txq); 326 327 if (status == NETDEV_TX_OK) 328 break; 329 330 } 331 332 /* tickle device maybe there is some cleanup */ 333 netpoll_poll_dev(np->dev); 334 335 udelay(USEC_PER_POLL); 336 } 337 338 WARN_ONCE(!irqs_disabled(), 339 "netpoll_send_skb(): %s enabled interrupts in poll (%pF)\n", 340 dev->name, ops->ndo_start_xmit); 341 342 local_irq_restore(flags); 343 } 344 345 if (status != NETDEV_TX_OK) { 346 skb_queue_tail(&npinfo->txq, skb); 347 schedule_delayed_work(&npinfo->tx_work,0); 348 } 349 } 350 EXPORT_SYMBOL(netpoll_send_skb_on_dev); 351 352 void netpoll_send_udp(struct netpoll *np, const char *msg, int len) 353 { 354 int total_len, eth_len, ip_len, udp_len; 355 struct sk_buff *skb; 356 struct udphdr *udph; 357 struct iphdr *iph; 358 struct ethhdr *eth; 359 360 udp_len = len + sizeof(*udph); 361 ip_len = eth_len = udp_len + sizeof(*iph); 362 total_len = eth_len + ETH_HLEN + NET_IP_ALIGN; 363 364 skb = find_skb(np, total_len, total_len - len); 365 if (!skb) 366 return; 367 368 skb_copy_to_linear_data(skb, msg, len); 369 skb->len += len; 370 371 skb_push(skb, sizeof(*udph)); 372 skb_reset_transport_header(skb); 373 udph = udp_hdr(skb); 374 udph->source = htons(np->local_port); 375 udph->dest = htons(np->remote_port); 376 udph->len = htons(udp_len); 377 udph->check = 0; 378 udph->check = csum_tcpudp_magic(np->local_ip, 379 np->remote_ip, 380 udp_len, IPPROTO_UDP, 381 csum_partial(udph, udp_len, 0)); 382 if (udph->check == 0) 383 udph->check = CSUM_MANGLED_0; 384 385 skb_push(skb, sizeof(*iph)); 386 skb_reset_network_header(skb); 387 iph = ip_hdr(skb); 388 389 /* iph->version = 4; iph->ihl = 5; */ 390 put_unaligned(0x45, (unsigned char *)iph); 391 iph->tos = 0; 392 put_unaligned(htons(ip_len), &(iph->tot_len)); 393 iph->id = 0; 394 iph->frag_off = 0; 395 iph->ttl = 64; 396 iph->protocol = IPPROTO_UDP; 397 iph->check = 0; 398 put_unaligned(np->local_ip, &(iph->saddr)); 399 put_unaligned(np->remote_ip, &(iph->daddr)); 400 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); 401 402 eth = (struct ethhdr *) skb_push(skb, ETH_HLEN); 403 skb_reset_mac_header(skb); 404 skb->protocol = eth->h_proto = htons(ETH_P_IP); 405 memcpy(eth->h_source, np->dev->dev_addr, ETH_ALEN); 406 memcpy(eth->h_dest, np->remote_mac, ETH_ALEN); 407 408 skb->dev = np->dev; 409 410 netpoll_send_skb(np, skb); 411 } 412 EXPORT_SYMBOL(netpoll_send_udp); 413 414 static void arp_reply(struct sk_buff *skb) 415 { 416 struct netpoll_info *npinfo = skb->dev->npinfo; 417 struct arphdr *arp; 418 unsigned char *arp_ptr; 419 int size, type = ARPOP_REPLY, ptype = ETH_P_ARP; 420 __be32 sip, tip; 421 unsigned char *sha; 422 struct sk_buff *send_skb; 423 struct netpoll *np, *tmp; 424 unsigned long flags; 425 int hlen, tlen; 426 int hits = 0; 427 428 if (list_empty(&npinfo->rx_np)) 429 return; 430 431 /* Before checking the packet, we do some early 432 inspection whether this is interesting at all */ 433 spin_lock_irqsave(&npinfo->rx_lock, flags); 434 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) { 435 if (np->dev == skb->dev) 436 hits++; 437 } 438 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 439 440 /* No netpoll struct is using this dev */ 441 if (!hits) 442 return; 443 444 /* No arp on this interface */ 445 if (skb->dev->flags & IFF_NOARP) 446 return; 447 448 if (!pskb_may_pull(skb, arp_hdr_len(skb->dev))) 449 return; 450 451 skb_reset_network_header(skb); 452 skb_reset_transport_header(skb); 453 arp = arp_hdr(skb); 454 455 if ((arp->ar_hrd != htons(ARPHRD_ETHER) && 456 arp->ar_hrd != htons(ARPHRD_IEEE802)) || 457 arp->ar_pro != htons(ETH_P_IP) || 458 arp->ar_op != htons(ARPOP_REQUEST)) 459 return; 460 461 arp_ptr = (unsigned char *)(arp+1); 462 /* save the location of the src hw addr */ 463 sha = arp_ptr; 464 arp_ptr += skb->dev->addr_len; 465 memcpy(&sip, arp_ptr, 4); 466 arp_ptr += 4; 467 /* If we actually cared about dst hw addr, 468 it would get copied here */ 469 arp_ptr += skb->dev->addr_len; 470 memcpy(&tip, arp_ptr, 4); 471 472 /* Should we ignore arp? */ 473 if (ipv4_is_loopback(tip) || ipv4_is_multicast(tip)) 474 return; 475 476 size = arp_hdr_len(skb->dev); 477 478 spin_lock_irqsave(&npinfo->rx_lock, flags); 479 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) { 480 if (tip != np->local_ip) 481 continue; 482 483 hlen = LL_RESERVED_SPACE(np->dev); 484 tlen = np->dev->needed_tailroom; 485 send_skb = find_skb(np, size + hlen + tlen, hlen); 486 if (!send_skb) 487 continue; 488 489 skb_reset_network_header(send_skb); 490 arp = (struct arphdr *) skb_put(send_skb, size); 491 send_skb->dev = skb->dev; 492 send_skb->protocol = htons(ETH_P_ARP); 493 494 /* Fill the device header for the ARP frame */ 495 if (dev_hard_header(send_skb, skb->dev, ptype, 496 sha, np->dev->dev_addr, 497 send_skb->len) < 0) { 498 kfree_skb(send_skb); 499 continue; 500 } 501 502 /* 503 * Fill out the arp protocol part. 504 * 505 * we only support ethernet device type, 506 * which (according to RFC 1390) should 507 * always equal 1 (Ethernet). 508 */ 509 510 arp->ar_hrd = htons(np->dev->type); 511 arp->ar_pro = htons(ETH_P_IP); 512 arp->ar_hln = np->dev->addr_len; 513 arp->ar_pln = 4; 514 arp->ar_op = htons(type); 515 516 arp_ptr = (unsigned char *)(arp + 1); 517 memcpy(arp_ptr, np->dev->dev_addr, np->dev->addr_len); 518 arp_ptr += np->dev->addr_len; 519 memcpy(arp_ptr, &tip, 4); 520 arp_ptr += 4; 521 memcpy(arp_ptr, sha, np->dev->addr_len); 522 arp_ptr += np->dev->addr_len; 523 memcpy(arp_ptr, &sip, 4); 524 525 netpoll_send_skb(np, send_skb); 526 527 /* If there are several rx_hooks for the same address, 528 we're fine by sending a single reply */ 529 break; 530 } 531 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 532 } 533 534 int __netpoll_rx(struct sk_buff *skb) 535 { 536 int proto, len, ulen; 537 int hits = 0; 538 const struct iphdr *iph; 539 struct udphdr *uh; 540 struct netpoll_info *npinfo = skb->dev->npinfo; 541 struct netpoll *np, *tmp; 542 543 if (list_empty(&npinfo->rx_np)) 544 goto out; 545 546 if (skb->dev->type != ARPHRD_ETHER) 547 goto out; 548 549 /* check if netpoll clients need ARP */ 550 if (skb->protocol == htons(ETH_P_ARP) && 551 atomic_read(&trapped)) { 552 skb_queue_tail(&npinfo->arp_tx, skb); 553 return 1; 554 } 555 556 proto = ntohs(eth_hdr(skb)->h_proto); 557 if (proto != ETH_P_IP) 558 goto out; 559 if (skb->pkt_type == PACKET_OTHERHOST) 560 goto out; 561 if (skb_shared(skb)) 562 goto out; 563 564 if (!pskb_may_pull(skb, sizeof(struct iphdr))) 565 goto out; 566 iph = (struct iphdr *)skb->data; 567 if (iph->ihl < 5 || iph->version != 4) 568 goto out; 569 if (!pskb_may_pull(skb, iph->ihl*4)) 570 goto out; 571 iph = (struct iphdr *)skb->data; 572 if (ip_fast_csum((u8 *)iph, iph->ihl) != 0) 573 goto out; 574 575 len = ntohs(iph->tot_len); 576 if (skb->len < len || len < iph->ihl*4) 577 goto out; 578 579 /* 580 * Our transport medium may have padded the buffer out. 581 * Now We trim to the true length of the frame. 582 */ 583 if (pskb_trim_rcsum(skb, len)) 584 goto out; 585 586 iph = (struct iphdr *)skb->data; 587 if (iph->protocol != IPPROTO_UDP) 588 goto out; 589 590 len -= iph->ihl*4; 591 uh = (struct udphdr *)(((char *)iph) + iph->ihl*4); 592 ulen = ntohs(uh->len); 593 594 if (ulen != len) 595 goto out; 596 if (checksum_udp(skb, uh, ulen, iph->saddr, iph->daddr)) 597 goto out; 598 599 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) { 600 if (np->local_ip && np->local_ip != iph->daddr) 601 continue; 602 if (np->remote_ip && np->remote_ip != iph->saddr) 603 continue; 604 if (np->local_port && np->local_port != ntohs(uh->dest)) 605 continue; 606 607 np->rx_hook(np, ntohs(uh->source), 608 (char *)(uh+1), 609 ulen - sizeof(struct udphdr)); 610 hits++; 611 } 612 613 if (!hits) 614 goto out; 615 616 kfree_skb(skb); 617 return 1; 618 619 out: 620 if (atomic_read(&trapped)) { 621 kfree_skb(skb); 622 return 1; 623 } 624 625 return 0; 626 } 627 628 void netpoll_print_options(struct netpoll *np) 629 { 630 printk(KERN_INFO "%s: local port %d\n", 631 np->name, np->local_port); 632 printk(KERN_INFO "%s: local IP %pI4\n", 633 np->name, &np->local_ip); 634 printk(KERN_INFO "%s: interface '%s'\n", 635 np->name, np->dev_name); 636 printk(KERN_INFO "%s: remote port %d\n", 637 np->name, np->remote_port); 638 printk(KERN_INFO "%s: remote IP %pI4\n", 639 np->name, &np->remote_ip); 640 printk(KERN_INFO "%s: remote ethernet address %pM\n", 641 np->name, np->remote_mac); 642 } 643 EXPORT_SYMBOL(netpoll_print_options); 644 645 int netpoll_parse_options(struct netpoll *np, char *opt) 646 { 647 char *cur=opt, *delim; 648 649 if (*cur != '@') { 650 if ((delim = strchr(cur, '@')) == NULL) 651 goto parse_failed; 652 *delim = 0; 653 np->local_port = simple_strtol(cur, NULL, 10); 654 cur = delim; 655 } 656 cur++; 657 658 if (*cur != '/') { 659 if ((delim = strchr(cur, '/')) == NULL) 660 goto parse_failed; 661 *delim = 0; 662 np->local_ip = in_aton(cur); 663 cur = delim; 664 } 665 cur++; 666 667 if (*cur != ',') { 668 /* parse out dev name */ 669 if ((delim = strchr(cur, ',')) == NULL) 670 goto parse_failed; 671 *delim = 0; 672 strlcpy(np->dev_name, cur, sizeof(np->dev_name)); 673 cur = delim; 674 } 675 cur++; 676 677 if (*cur != '@') { 678 /* dst port */ 679 if ((delim = strchr(cur, '@')) == NULL) 680 goto parse_failed; 681 *delim = 0; 682 if (*cur == ' ' || *cur == '\t') 683 printk(KERN_INFO "%s: warning: whitespace" 684 "is not allowed\n", np->name); 685 np->remote_port = simple_strtol(cur, NULL, 10); 686 cur = delim; 687 } 688 cur++; 689 690 /* dst ip */ 691 if ((delim = strchr(cur, '/')) == NULL) 692 goto parse_failed; 693 *delim = 0; 694 np->remote_ip = in_aton(cur); 695 cur = delim + 1; 696 697 if (*cur != 0) { 698 /* MAC address */ 699 if (!mac_pton(cur, np->remote_mac)) 700 goto parse_failed; 701 } 702 703 netpoll_print_options(np); 704 705 return 0; 706 707 parse_failed: 708 printk(KERN_INFO "%s: couldn't parse config at '%s'!\n", 709 np->name, cur); 710 return -1; 711 } 712 EXPORT_SYMBOL(netpoll_parse_options); 713 714 int __netpoll_setup(struct netpoll *np) 715 { 716 struct net_device *ndev = np->dev; 717 struct netpoll_info *npinfo; 718 const struct net_device_ops *ops; 719 unsigned long flags; 720 int err; 721 722 if ((ndev->priv_flags & IFF_DISABLE_NETPOLL) || 723 !ndev->netdev_ops->ndo_poll_controller) { 724 printk(KERN_ERR "%s: %s doesn't support polling, aborting.\n", 725 np->name, np->dev_name); 726 err = -ENOTSUPP; 727 goto out; 728 } 729 730 if (!ndev->npinfo) { 731 npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL); 732 if (!npinfo) { 733 err = -ENOMEM; 734 goto out; 735 } 736 737 npinfo->rx_flags = 0; 738 INIT_LIST_HEAD(&npinfo->rx_np); 739 740 spin_lock_init(&npinfo->rx_lock); 741 skb_queue_head_init(&npinfo->arp_tx); 742 skb_queue_head_init(&npinfo->txq); 743 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process); 744 745 atomic_set(&npinfo->refcnt, 1); 746 747 ops = np->dev->netdev_ops; 748 if (ops->ndo_netpoll_setup) { 749 err = ops->ndo_netpoll_setup(ndev, npinfo); 750 if (err) 751 goto free_npinfo; 752 } 753 } else { 754 npinfo = ndev->npinfo; 755 atomic_inc(&npinfo->refcnt); 756 } 757 758 npinfo->netpoll = np; 759 760 if (np->rx_hook) { 761 spin_lock_irqsave(&npinfo->rx_lock, flags); 762 npinfo->rx_flags |= NETPOLL_RX_ENABLED; 763 list_add_tail(&np->rx, &npinfo->rx_np); 764 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 765 } 766 767 /* last thing to do is link it to the net device structure */ 768 rcu_assign_pointer(ndev->npinfo, npinfo); 769 770 return 0; 771 772 free_npinfo: 773 kfree(npinfo); 774 out: 775 return err; 776 } 777 EXPORT_SYMBOL_GPL(__netpoll_setup); 778 779 int netpoll_setup(struct netpoll *np) 780 { 781 struct net_device *ndev = NULL; 782 struct in_device *in_dev; 783 int err; 784 785 if (np->dev_name) 786 ndev = dev_get_by_name(&init_net, np->dev_name); 787 if (!ndev) { 788 printk(KERN_ERR "%s: %s doesn't exist, aborting.\n", 789 np->name, np->dev_name); 790 return -ENODEV; 791 } 792 793 if (ndev->master) { 794 printk(KERN_ERR "%s: %s is a slave device, aborting.\n", 795 np->name, np->dev_name); 796 err = -EBUSY; 797 goto put; 798 } 799 800 if (!netif_running(ndev)) { 801 unsigned long atmost, atleast; 802 803 printk(KERN_INFO "%s: device %s not up yet, forcing it\n", 804 np->name, np->dev_name); 805 806 rtnl_lock(); 807 err = dev_open(ndev); 808 rtnl_unlock(); 809 810 if (err) { 811 printk(KERN_ERR "%s: failed to open %s\n", 812 np->name, ndev->name); 813 goto put; 814 } 815 816 atleast = jiffies + HZ/10; 817 atmost = jiffies + carrier_timeout * HZ; 818 while (!netif_carrier_ok(ndev)) { 819 if (time_after(jiffies, atmost)) { 820 printk(KERN_NOTICE 821 "%s: timeout waiting for carrier\n", 822 np->name); 823 break; 824 } 825 msleep(1); 826 } 827 828 /* If carrier appears to come up instantly, we don't 829 * trust it and pause so that we don't pump all our 830 * queued console messages into the bitbucket. 831 */ 832 833 if (time_before(jiffies, atleast)) { 834 printk(KERN_NOTICE "%s: carrier detect appears" 835 " untrustworthy, waiting 4 seconds\n", 836 np->name); 837 msleep(4000); 838 } 839 } 840 841 if (!np->local_ip) { 842 rcu_read_lock(); 843 in_dev = __in_dev_get_rcu(ndev); 844 845 if (!in_dev || !in_dev->ifa_list) { 846 rcu_read_unlock(); 847 printk(KERN_ERR "%s: no IP address for %s, aborting\n", 848 np->name, np->dev_name); 849 err = -EDESTADDRREQ; 850 goto put; 851 } 852 853 np->local_ip = in_dev->ifa_list->ifa_local; 854 rcu_read_unlock(); 855 printk(KERN_INFO "%s: local IP %pI4\n", np->name, &np->local_ip); 856 } 857 858 np->dev = ndev; 859 860 /* fill up the skb queue */ 861 refill_skbs(); 862 863 rtnl_lock(); 864 err = __netpoll_setup(np); 865 rtnl_unlock(); 866 867 if (err) 868 goto put; 869 870 return 0; 871 872 put: 873 dev_put(ndev); 874 return err; 875 } 876 EXPORT_SYMBOL(netpoll_setup); 877 878 static int __init netpoll_init(void) 879 { 880 skb_queue_head_init(&skb_pool); 881 return 0; 882 } 883 core_initcall(netpoll_init); 884 885 void __netpoll_cleanup(struct netpoll *np) 886 { 887 struct netpoll_info *npinfo; 888 unsigned long flags; 889 890 npinfo = np->dev->npinfo; 891 if (!npinfo) 892 return; 893 894 if (!list_empty(&npinfo->rx_np)) { 895 spin_lock_irqsave(&npinfo->rx_lock, flags); 896 list_del(&np->rx); 897 if (list_empty(&npinfo->rx_np)) 898 npinfo->rx_flags &= ~NETPOLL_RX_ENABLED; 899 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 900 } 901 902 if (atomic_dec_and_test(&npinfo->refcnt)) { 903 const struct net_device_ops *ops; 904 905 ops = np->dev->netdev_ops; 906 if (ops->ndo_netpoll_cleanup) 907 ops->ndo_netpoll_cleanup(np->dev); 908 909 RCU_INIT_POINTER(np->dev->npinfo, NULL); 910 911 /* avoid racing with NAPI reading npinfo */ 912 synchronize_rcu_bh(); 913 914 skb_queue_purge(&npinfo->arp_tx); 915 skb_queue_purge(&npinfo->txq); 916 cancel_delayed_work_sync(&npinfo->tx_work); 917 918 /* clean after last, unfinished work */ 919 __skb_queue_purge(&npinfo->txq); 920 kfree(npinfo); 921 } 922 } 923 EXPORT_SYMBOL_GPL(__netpoll_cleanup); 924 925 void netpoll_cleanup(struct netpoll *np) 926 { 927 if (!np->dev) 928 return; 929 930 rtnl_lock(); 931 __netpoll_cleanup(np); 932 rtnl_unlock(); 933 934 dev_put(np->dev); 935 np->dev = NULL; 936 } 937 EXPORT_SYMBOL(netpoll_cleanup); 938 939 int netpoll_trap(void) 940 { 941 return atomic_read(&trapped); 942 } 943 EXPORT_SYMBOL(netpoll_trap); 944 945 void netpoll_set_trap(int trap) 946 { 947 if (trap) 948 atomic_inc(&trapped); 949 else 950 atomic_dec(&trapped); 951 } 952 EXPORT_SYMBOL(netpoll_set_trap); 953