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 <net/tcp.h> 26 #include <net/udp.h> 27 #include <asm/unaligned.h> 28 #include <trace/events/napi.h> 29 30 /* 31 * We maintain a small pool of fully-sized skbs, to make sure the 32 * message gets out even in extreme OOM situations. 33 */ 34 35 #define MAX_UDP_CHUNK 1460 36 #define MAX_SKBS 32 37 #define MAX_QUEUE_DEPTH (MAX_SKBS / 2) 38 39 static struct sk_buff_head skb_pool; 40 41 static atomic_t trapped; 42 43 #define USEC_PER_POLL 50 44 #define NETPOLL_RX_ENABLED 1 45 #define NETPOLL_RX_DROP 2 46 47 #define MAX_SKB_SIZE \ 48 (MAX_UDP_CHUNK + sizeof(struct udphdr) + \ 49 sizeof(struct iphdr) + sizeof(struct ethhdr)) 50 51 static void zap_completion_queue(void); 52 static void arp_reply(struct sk_buff *skb); 53 54 static unsigned int carrier_timeout = 4; 55 module_param(carrier_timeout, uint, 0644); 56 57 static void queue_process(struct work_struct *work) 58 { 59 struct netpoll_info *npinfo = 60 container_of(work, struct netpoll_info, tx_work.work); 61 struct sk_buff *skb; 62 unsigned long flags; 63 64 while ((skb = skb_dequeue(&npinfo->txq))) { 65 struct net_device *dev = skb->dev; 66 const struct net_device_ops *ops = dev->netdev_ops; 67 struct netdev_queue *txq; 68 69 if (!netif_device_present(dev) || !netif_running(dev)) { 70 __kfree_skb(skb); 71 continue; 72 } 73 74 txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb)); 75 76 local_irq_save(flags); 77 __netif_tx_lock(txq, smp_processor_id()); 78 if (netif_tx_queue_stopped(txq) || 79 netif_tx_queue_frozen(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 void netpoll_poll(struct netpoll *np) 182 { 183 struct net_device *dev = np->dev; 184 const struct net_device_ops *ops; 185 186 if (!dev || !netif_running(dev)) 187 return; 188 189 ops = dev->netdev_ops; 190 if (!ops->ndo_poll_controller) 191 return; 192 193 /* Process pending work on NIC */ 194 ops->ndo_poll_controller(dev); 195 196 poll_napi(dev); 197 198 service_arp_queue(dev->npinfo); 199 200 zap_completion_queue(); 201 } 202 203 static void refill_skbs(void) 204 { 205 struct sk_buff *skb; 206 unsigned long flags; 207 208 spin_lock_irqsave(&skb_pool.lock, flags); 209 while (skb_pool.qlen < MAX_SKBS) { 210 skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC); 211 if (!skb) 212 break; 213 214 __skb_queue_tail(&skb_pool, skb); 215 } 216 spin_unlock_irqrestore(&skb_pool.lock, flags); 217 } 218 219 static void zap_completion_queue(void) 220 { 221 unsigned long flags; 222 struct softnet_data *sd = &get_cpu_var(softnet_data); 223 224 if (sd->completion_queue) { 225 struct sk_buff *clist; 226 227 local_irq_save(flags); 228 clist = sd->completion_queue; 229 sd->completion_queue = NULL; 230 local_irq_restore(flags); 231 232 while (clist != NULL) { 233 struct sk_buff *skb = clist; 234 clist = clist->next; 235 if (skb->destructor) { 236 atomic_inc(&skb->users); 237 dev_kfree_skb_any(skb); /* put this one back */ 238 } else { 239 __kfree_skb(skb); 240 } 241 } 242 } 243 244 put_cpu_var(softnet_data); 245 } 246 247 static struct sk_buff *find_skb(struct netpoll *np, int len, int reserve) 248 { 249 int count = 0; 250 struct sk_buff *skb; 251 252 zap_completion_queue(); 253 refill_skbs(); 254 repeat: 255 256 skb = alloc_skb(len, GFP_ATOMIC); 257 if (!skb) 258 skb = skb_dequeue(&skb_pool); 259 260 if (!skb) { 261 if (++count < 10) { 262 netpoll_poll(np); 263 goto repeat; 264 } 265 return NULL; 266 } 267 268 atomic_set(&skb->users, 1); 269 skb_reserve(skb, reserve); 270 return skb; 271 } 272 273 static int netpoll_owner_active(struct net_device *dev) 274 { 275 struct napi_struct *napi; 276 277 list_for_each_entry(napi, &dev->napi_list, dev_list) { 278 if (napi->poll_owner == smp_processor_id()) 279 return 1; 280 } 281 return 0; 282 } 283 284 static void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb) 285 { 286 int status = NETDEV_TX_BUSY; 287 unsigned long tries; 288 struct net_device *dev = np->dev; 289 const struct net_device_ops *ops = dev->netdev_ops; 290 struct netpoll_info *npinfo = np->dev->npinfo; 291 292 if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) { 293 __kfree_skb(skb); 294 return; 295 } 296 297 /* don't get messages out of order, and no recursion */ 298 if (skb_queue_len(&npinfo->txq) == 0 && !netpoll_owner_active(dev)) { 299 struct netdev_queue *txq; 300 unsigned long flags; 301 302 txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb)); 303 304 local_irq_save(flags); 305 /* try until next clock tick */ 306 for (tries = jiffies_to_usecs(1)/USEC_PER_POLL; 307 tries > 0; --tries) { 308 if (__netif_tx_trylock(txq)) { 309 if (!netif_tx_queue_stopped(txq)) { 310 status = ops->ndo_start_xmit(skb, dev); 311 if (status == NETDEV_TX_OK) 312 txq_trans_update(txq); 313 } 314 __netif_tx_unlock(txq); 315 316 if (status == NETDEV_TX_OK) 317 break; 318 319 } 320 321 /* tickle device maybe there is some cleanup */ 322 netpoll_poll(np); 323 324 udelay(USEC_PER_POLL); 325 } 326 327 WARN_ONCE(!irqs_disabled(), 328 "netpoll_send_skb(): %s enabled interrupts in poll (%pF)\n", 329 dev->name, ops->ndo_start_xmit); 330 331 local_irq_restore(flags); 332 } 333 334 if (status != NETDEV_TX_OK) { 335 skb_queue_tail(&npinfo->txq, skb); 336 schedule_delayed_work(&npinfo->tx_work,0); 337 } 338 } 339 340 void netpoll_send_udp(struct netpoll *np, const char *msg, int len) 341 { 342 int total_len, eth_len, ip_len, udp_len; 343 struct sk_buff *skb; 344 struct udphdr *udph; 345 struct iphdr *iph; 346 struct ethhdr *eth; 347 348 udp_len = len + sizeof(*udph); 349 ip_len = eth_len = udp_len + sizeof(*iph); 350 total_len = eth_len + ETH_HLEN + NET_IP_ALIGN; 351 352 skb = find_skb(np, total_len, total_len - len); 353 if (!skb) 354 return; 355 356 skb_copy_to_linear_data(skb, msg, len); 357 skb->len += len; 358 359 skb_push(skb, sizeof(*udph)); 360 skb_reset_transport_header(skb); 361 udph = udp_hdr(skb); 362 udph->source = htons(np->local_port); 363 udph->dest = htons(np->remote_port); 364 udph->len = htons(udp_len); 365 udph->check = 0; 366 udph->check = csum_tcpudp_magic(np->local_ip, 367 np->remote_ip, 368 udp_len, IPPROTO_UDP, 369 csum_partial(udph, udp_len, 0)); 370 if (udph->check == 0) 371 udph->check = CSUM_MANGLED_0; 372 373 skb_push(skb, sizeof(*iph)); 374 skb_reset_network_header(skb); 375 iph = ip_hdr(skb); 376 377 /* iph->version = 4; iph->ihl = 5; */ 378 put_unaligned(0x45, (unsigned char *)iph); 379 iph->tos = 0; 380 put_unaligned(htons(ip_len), &(iph->tot_len)); 381 iph->id = 0; 382 iph->frag_off = 0; 383 iph->ttl = 64; 384 iph->protocol = IPPROTO_UDP; 385 iph->check = 0; 386 put_unaligned(np->local_ip, &(iph->saddr)); 387 put_unaligned(np->remote_ip, &(iph->daddr)); 388 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); 389 390 eth = (struct ethhdr *) skb_push(skb, ETH_HLEN); 391 skb_reset_mac_header(skb); 392 skb->protocol = eth->h_proto = htons(ETH_P_IP); 393 memcpy(eth->h_source, np->dev->dev_addr, ETH_ALEN); 394 memcpy(eth->h_dest, np->remote_mac, ETH_ALEN); 395 396 skb->dev = np->dev; 397 398 netpoll_send_skb(np, skb); 399 } 400 401 static void arp_reply(struct sk_buff *skb) 402 { 403 struct netpoll_info *npinfo = skb->dev->npinfo; 404 struct arphdr *arp; 405 unsigned char *arp_ptr; 406 int size, type = ARPOP_REPLY, ptype = ETH_P_ARP; 407 __be32 sip, tip; 408 unsigned char *sha; 409 struct sk_buff *send_skb; 410 struct netpoll *np, *tmp; 411 unsigned long flags; 412 int hits = 0; 413 414 if (list_empty(&npinfo->rx_np)) 415 return; 416 417 /* Before checking the packet, we do some early 418 inspection whether this is interesting at all */ 419 spin_lock_irqsave(&npinfo->rx_lock, flags); 420 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) { 421 if (np->dev == skb->dev) 422 hits++; 423 } 424 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 425 426 /* No netpoll struct is using this dev */ 427 if (!hits) 428 return; 429 430 /* No arp on this interface */ 431 if (skb->dev->flags & IFF_NOARP) 432 return; 433 434 if (!pskb_may_pull(skb, arp_hdr_len(skb->dev))) 435 return; 436 437 skb_reset_network_header(skb); 438 skb_reset_transport_header(skb); 439 arp = arp_hdr(skb); 440 441 if ((arp->ar_hrd != htons(ARPHRD_ETHER) && 442 arp->ar_hrd != htons(ARPHRD_IEEE802)) || 443 arp->ar_pro != htons(ETH_P_IP) || 444 arp->ar_op != htons(ARPOP_REQUEST)) 445 return; 446 447 arp_ptr = (unsigned char *)(arp+1); 448 /* save the location of the src hw addr */ 449 sha = arp_ptr; 450 arp_ptr += skb->dev->addr_len; 451 memcpy(&sip, arp_ptr, 4); 452 arp_ptr += 4; 453 /* If we actually cared about dst hw addr, 454 it would get copied here */ 455 arp_ptr += skb->dev->addr_len; 456 memcpy(&tip, arp_ptr, 4); 457 458 /* Should we ignore arp? */ 459 if (ipv4_is_loopback(tip) || ipv4_is_multicast(tip)) 460 return; 461 462 size = arp_hdr_len(skb->dev); 463 464 spin_lock_irqsave(&npinfo->rx_lock, flags); 465 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) { 466 if (tip != np->local_ip) 467 continue; 468 469 send_skb = find_skb(np, size + LL_ALLOCATED_SPACE(np->dev), 470 LL_RESERVED_SPACE(np->dev)); 471 if (!send_skb) 472 continue; 473 474 skb_reset_network_header(send_skb); 475 arp = (struct arphdr *) skb_put(send_skb, size); 476 send_skb->dev = skb->dev; 477 send_skb->protocol = htons(ETH_P_ARP); 478 479 /* Fill the device header for the ARP frame */ 480 if (dev_hard_header(send_skb, skb->dev, ptype, 481 sha, np->dev->dev_addr, 482 send_skb->len) < 0) { 483 kfree_skb(send_skb); 484 continue; 485 } 486 487 /* 488 * Fill out the arp protocol part. 489 * 490 * we only support ethernet device type, 491 * which (according to RFC 1390) should 492 * always equal 1 (Ethernet). 493 */ 494 495 arp->ar_hrd = htons(np->dev->type); 496 arp->ar_pro = htons(ETH_P_IP); 497 arp->ar_hln = np->dev->addr_len; 498 arp->ar_pln = 4; 499 arp->ar_op = htons(type); 500 501 arp_ptr = (unsigned char *)(arp + 1); 502 memcpy(arp_ptr, np->dev->dev_addr, np->dev->addr_len); 503 arp_ptr += np->dev->addr_len; 504 memcpy(arp_ptr, &tip, 4); 505 arp_ptr += 4; 506 memcpy(arp_ptr, sha, np->dev->addr_len); 507 arp_ptr += np->dev->addr_len; 508 memcpy(arp_ptr, &sip, 4); 509 510 netpoll_send_skb(np, send_skb); 511 512 /* If there are several rx_hooks for the same address, 513 we're fine by sending a single reply */ 514 break; 515 } 516 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 517 } 518 519 int __netpoll_rx(struct sk_buff *skb) 520 { 521 int proto, len, ulen; 522 int hits = 0; 523 struct iphdr *iph; 524 struct udphdr *uh; 525 struct netpoll_info *npinfo = skb->dev->npinfo; 526 struct netpoll *np, *tmp; 527 528 if (list_empty(&npinfo->rx_np)) 529 goto out; 530 531 if (skb->dev->type != ARPHRD_ETHER) 532 goto out; 533 534 /* check if netpoll clients need ARP */ 535 if (skb->protocol == htons(ETH_P_ARP) && 536 atomic_read(&trapped)) { 537 skb_queue_tail(&npinfo->arp_tx, skb); 538 return 1; 539 } 540 541 proto = ntohs(eth_hdr(skb)->h_proto); 542 if (proto != ETH_P_IP) 543 goto out; 544 if (skb->pkt_type == PACKET_OTHERHOST) 545 goto out; 546 if (skb_shared(skb)) 547 goto out; 548 549 iph = (struct iphdr *)skb->data; 550 if (!pskb_may_pull(skb, sizeof(struct iphdr))) 551 goto out; 552 if (iph->ihl < 5 || iph->version != 4) 553 goto out; 554 if (!pskb_may_pull(skb, iph->ihl*4)) 555 goto out; 556 if (ip_fast_csum((u8 *)iph, iph->ihl) != 0) 557 goto out; 558 559 len = ntohs(iph->tot_len); 560 if (skb->len < len || len < iph->ihl*4) 561 goto out; 562 563 /* 564 * Our transport medium may have padded the buffer out. 565 * Now We trim to the true length of the frame. 566 */ 567 if (pskb_trim_rcsum(skb, len)) 568 goto out; 569 570 if (iph->protocol != IPPROTO_UDP) 571 goto out; 572 573 len -= iph->ihl*4; 574 uh = (struct udphdr *)(((char *)iph) + iph->ihl*4); 575 ulen = ntohs(uh->len); 576 577 if (ulen != len) 578 goto out; 579 if (checksum_udp(skb, uh, ulen, iph->saddr, iph->daddr)) 580 goto out; 581 582 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) { 583 if (np->local_ip && np->local_ip != iph->daddr) 584 continue; 585 if (np->remote_ip && np->remote_ip != iph->saddr) 586 continue; 587 if (np->local_port && np->local_port != ntohs(uh->dest)) 588 continue; 589 590 np->rx_hook(np, ntohs(uh->source), 591 (char *)(uh+1), 592 ulen - sizeof(struct udphdr)); 593 hits++; 594 } 595 596 if (!hits) 597 goto out; 598 599 kfree_skb(skb); 600 return 1; 601 602 out: 603 if (atomic_read(&trapped)) { 604 kfree_skb(skb); 605 return 1; 606 } 607 608 return 0; 609 } 610 611 void netpoll_print_options(struct netpoll *np) 612 { 613 printk(KERN_INFO "%s: local port %d\n", 614 np->name, np->local_port); 615 printk(KERN_INFO "%s: local IP %pI4\n", 616 np->name, &np->local_ip); 617 printk(KERN_INFO "%s: interface %s\n", 618 np->name, np->dev_name); 619 printk(KERN_INFO "%s: remote port %d\n", 620 np->name, np->remote_port); 621 printk(KERN_INFO "%s: remote IP %pI4\n", 622 np->name, &np->remote_ip); 623 printk(KERN_INFO "%s: remote ethernet address %pM\n", 624 np->name, np->remote_mac); 625 } 626 627 int netpoll_parse_options(struct netpoll *np, char *opt) 628 { 629 char *cur=opt, *delim; 630 631 if (*cur != '@') { 632 if ((delim = strchr(cur, '@')) == NULL) 633 goto parse_failed; 634 *delim = 0; 635 np->local_port = simple_strtol(cur, NULL, 10); 636 cur = delim; 637 } 638 cur++; 639 640 if (*cur != '/') { 641 if ((delim = strchr(cur, '/')) == NULL) 642 goto parse_failed; 643 *delim = 0; 644 np->local_ip = in_aton(cur); 645 cur = delim; 646 } 647 cur++; 648 649 if (*cur != ',') { 650 /* parse out dev name */ 651 if ((delim = strchr(cur, ',')) == NULL) 652 goto parse_failed; 653 *delim = 0; 654 strlcpy(np->dev_name, cur, sizeof(np->dev_name)); 655 cur = delim; 656 } 657 cur++; 658 659 if (*cur != '@') { 660 /* dst port */ 661 if ((delim = strchr(cur, '@')) == NULL) 662 goto parse_failed; 663 *delim = 0; 664 np->remote_port = simple_strtol(cur, NULL, 10); 665 cur = delim; 666 } 667 cur++; 668 669 /* dst ip */ 670 if ((delim = strchr(cur, '/')) == NULL) 671 goto parse_failed; 672 *delim = 0; 673 np->remote_ip = in_aton(cur); 674 cur = delim + 1; 675 676 if (*cur != 0) { 677 /* MAC address */ 678 if ((delim = strchr(cur, ':')) == NULL) 679 goto parse_failed; 680 *delim = 0; 681 np->remote_mac[0] = simple_strtol(cur, NULL, 16); 682 cur = delim + 1; 683 if ((delim = strchr(cur, ':')) == NULL) 684 goto parse_failed; 685 *delim = 0; 686 np->remote_mac[1] = simple_strtol(cur, NULL, 16); 687 cur = delim + 1; 688 if ((delim = strchr(cur, ':')) == NULL) 689 goto parse_failed; 690 *delim = 0; 691 np->remote_mac[2] = simple_strtol(cur, NULL, 16); 692 cur = delim + 1; 693 if ((delim = strchr(cur, ':')) == NULL) 694 goto parse_failed; 695 *delim = 0; 696 np->remote_mac[3] = simple_strtol(cur, NULL, 16); 697 cur = delim + 1; 698 if ((delim = strchr(cur, ':')) == NULL) 699 goto parse_failed; 700 *delim = 0; 701 np->remote_mac[4] = simple_strtol(cur, NULL, 16); 702 cur = delim + 1; 703 np->remote_mac[5] = simple_strtol(cur, NULL, 16); 704 } 705 706 netpoll_print_options(np); 707 708 return 0; 709 710 parse_failed: 711 printk(KERN_INFO "%s: couldn't parse config at %s!\n", 712 np->name, cur); 713 return -1; 714 } 715 716 int netpoll_setup(struct netpoll *np) 717 { 718 struct net_device *ndev = NULL; 719 struct in_device *in_dev; 720 struct netpoll_info *npinfo; 721 struct netpoll *npe, *tmp; 722 unsigned long flags; 723 int err; 724 725 if (np->dev_name) 726 ndev = dev_get_by_name(&init_net, np->dev_name); 727 if (!ndev) { 728 printk(KERN_ERR "%s: %s doesn't exist, aborting.\n", 729 np->name, np->dev_name); 730 return -ENODEV; 731 } 732 733 np->dev = ndev; 734 if (!ndev->npinfo) { 735 npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL); 736 if (!npinfo) { 737 err = -ENOMEM; 738 goto release; 739 } 740 741 npinfo->rx_flags = 0; 742 INIT_LIST_HEAD(&npinfo->rx_np); 743 744 spin_lock_init(&npinfo->rx_lock); 745 skb_queue_head_init(&npinfo->arp_tx); 746 skb_queue_head_init(&npinfo->txq); 747 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process); 748 749 atomic_set(&npinfo->refcnt, 1); 750 } else { 751 npinfo = ndev->npinfo; 752 atomic_inc(&npinfo->refcnt); 753 } 754 755 if (!ndev->netdev_ops->ndo_poll_controller) { 756 printk(KERN_ERR "%s: %s doesn't support polling, aborting.\n", 757 np->name, np->dev_name); 758 err = -ENOTSUPP; 759 goto release; 760 } 761 762 if (!netif_running(ndev)) { 763 unsigned long atmost, atleast; 764 765 printk(KERN_INFO "%s: device %s not up yet, forcing it\n", 766 np->name, np->dev_name); 767 768 rtnl_lock(); 769 err = dev_open(ndev); 770 rtnl_unlock(); 771 772 if (err) { 773 printk(KERN_ERR "%s: failed to open %s\n", 774 np->name, ndev->name); 775 goto release; 776 } 777 778 atleast = jiffies + HZ/10; 779 atmost = jiffies + carrier_timeout * HZ; 780 while (!netif_carrier_ok(ndev)) { 781 if (time_after(jiffies, atmost)) { 782 printk(KERN_NOTICE 783 "%s: timeout waiting for carrier\n", 784 np->name); 785 break; 786 } 787 msleep(1); 788 } 789 790 /* If carrier appears to come up instantly, we don't 791 * trust it and pause so that we don't pump all our 792 * queued console messages into the bitbucket. 793 */ 794 795 if (time_before(jiffies, atleast)) { 796 printk(KERN_NOTICE "%s: carrier detect appears" 797 " untrustworthy, waiting 4 seconds\n", 798 np->name); 799 msleep(4000); 800 } 801 } 802 803 if (!np->local_ip) { 804 rcu_read_lock(); 805 in_dev = __in_dev_get_rcu(ndev); 806 807 if (!in_dev || !in_dev->ifa_list) { 808 rcu_read_unlock(); 809 printk(KERN_ERR "%s: no IP address for %s, aborting\n", 810 np->name, np->dev_name); 811 err = -EDESTADDRREQ; 812 goto release; 813 } 814 815 np->local_ip = in_dev->ifa_list->ifa_local; 816 rcu_read_unlock(); 817 printk(KERN_INFO "%s: local IP %pI4\n", np->name, &np->local_ip); 818 } 819 820 if (np->rx_hook) { 821 spin_lock_irqsave(&npinfo->rx_lock, flags); 822 npinfo->rx_flags |= NETPOLL_RX_ENABLED; 823 list_add_tail(&np->rx, &npinfo->rx_np); 824 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 825 } 826 827 /* fill up the skb queue */ 828 refill_skbs(); 829 830 /* last thing to do is link it to the net device structure */ 831 ndev->npinfo = npinfo; 832 833 /* avoid racing with NAPI reading npinfo */ 834 synchronize_rcu(); 835 836 return 0; 837 838 release: 839 if (!ndev->npinfo) { 840 spin_lock_irqsave(&npinfo->rx_lock, flags); 841 list_for_each_entry_safe(npe, tmp, &npinfo->rx_np, rx) { 842 npe->dev = NULL; 843 } 844 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 845 846 kfree(npinfo); 847 } 848 849 dev_put(ndev); 850 return err; 851 } 852 853 static int __init netpoll_init(void) 854 { 855 skb_queue_head_init(&skb_pool); 856 return 0; 857 } 858 core_initcall(netpoll_init); 859 860 void netpoll_cleanup(struct netpoll *np) 861 { 862 struct netpoll_info *npinfo; 863 unsigned long flags; 864 865 if (np->dev) { 866 npinfo = np->dev->npinfo; 867 if (npinfo) { 868 if (!list_empty(&npinfo->rx_np)) { 869 spin_lock_irqsave(&npinfo->rx_lock, flags); 870 list_del(&np->rx); 871 if (list_empty(&npinfo->rx_np)) 872 npinfo->rx_flags &= ~NETPOLL_RX_ENABLED; 873 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 874 } 875 876 if (atomic_dec_and_test(&npinfo->refcnt)) { 877 skb_queue_purge(&npinfo->arp_tx); 878 skb_queue_purge(&npinfo->txq); 879 cancel_rearming_delayed_work(&npinfo->tx_work); 880 881 /* clean after last, unfinished work */ 882 __skb_queue_purge(&npinfo->txq); 883 kfree(npinfo); 884 np->dev->npinfo = NULL; 885 } 886 } 887 888 dev_put(np->dev); 889 } 890 891 np->dev = NULL; 892 } 893 894 int netpoll_trap(void) 895 { 896 return atomic_read(&trapped); 897 } 898 899 void netpoll_set_trap(int trap) 900 { 901 if (trap) 902 atomic_inc(&trapped); 903 else 904 atomic_dec(&trapped); 905 } 906 907 EXPORT_SYMBOL(netpoll_set_trap); 908 EXPORT_SYMBOL(netpoll_trap); 909 EXPORT_SYMBOL(netpoll_print_options); 910 EXPORT_SYMBOL(netpoll_parse_options); 911 EXPORT_SYMBOL(netpoll_setup); 912 EXPORT_SYMBOL(netpoll_cleanup); 913 EXPORT_SYMBOL(netpoll_send_udp); 914 EXPORT_SYMBOL(netpoll_poll); 915