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/netdevice.h> 13 #include <linux/etherdevice.h> 14 #include <linux/string.h> 15 #include <linux/if_arp.h> 16 #include <linux/inetdevice.h> 17 #include <linux/inet.h> 18 #include <linux/interrupt.h> 19 #include <linux/netpoll.h> 20 #include <linux/sched.h> 21 #include <linux/delay.h> 22 #include <linux/rcupdate.h> 23 #include <linux/workqueue.h> 24 #include <net/tcp.h> 25 #include <net/udp.h> 26 #include <asm/unaligned.h> 27 28 /* 29 * We maintain a small pool of fully-sized skbs, to make sure the 30 * message gets out even in extreme OOM situations. 31 */ 32 33 #define MAX_UDP_CHUNK 1460 34 #define MAX_SKBS 32 35 #define MAX_QUEUE_DEPTH (MAX_SKBS / 2) 36 37 static struct sk_buff_head skb_pool; 38 39 static atomic_t trapped; 40 41 #define USEC_PER_POLL 50 42 #define NETPOLL_RX_ENABLED 1 43 #define NETPOLL_RX_DROP 2 44 45 #define MAX_SKB_SIZE \ 46 (MAX_UDP_CHUNK + sizeof(struct udphdr) + \ 47 sizeof(struct iphdr) + sizeof(struct ethhdr)) 48 49 static void zap_completion_queue(void); 50 static void arp_reply(struct sk_buff *skb); 51 52 static void queue_process(struct work_struct *work) 53 { 54 struct netpoll_info *npinfo = 55 container_of(work, struct netpoll_info, tx_work.work); 56 struct sk_buff *skb; 57 unsigned long flags; 58 59 while ((skb = skb_dequeue(&npinfo->txq))) { 60 struct net_device *dev = skb->dev; 61 62 if (!netif_device_present(dev) || !netif_running(dev)) { 63 __kfree_skb(skb); 64 continue; 65 } 66 67 local_irq_save(flags); 68 netif_tx_lock(dev); 69 if ((netif_queue_stopped(dev) || 70 netif_subqueue_stopped(dev, skb)) || 71 dev->hard_start_xmit(skb, dev) != NETDEV_TX_OK) { 72 skb_queue_head(&npinfo->txq, skb); 73 netif_tx_unlock(dev); 74 local_irq_restore(flags); 75 76 schedule_delayed_work(&npinfo->tx_work, HZ/10); 77 return; 78 } 79 netif_tx_unlock(dev); 80 local_irq_restore(flags); 81 } 82 } 83 84 static __sum16 checksum_udp(struct sk_buff *skb, struct udphdr *uh, 85 unsigned short ulen, __be32 saddr, __be32 daddr) 86 { 87 __wsum psum; 88 89 if (uh->check == 0 || skb_csum_unnecessary(skb)) 90 return 0; 91 92 psum = csum_tcpudp_nofold(saddr, daddr, ulen, IPPROTO_UDP, 0); 93 94 if (skb->ip_summed == CHECKSUM_COMPLETE && 95 !csum_fold(csum_add(psum, skb->csum))) 96 return 0; 97 98 skb->csum = psum; 99 100 return __skb_checksum_complete(skb); 101 } 102 103 /* 104 * Check whether delayed processing was scheduled for our NIC. If so, 105 * we attempt to grab the poll lock and use ->poll() to pump the card. 106 * If this fails, either we've recursed in ->poll() or it's already 107 * running on another CPU. 108 * 109 * Note: we don't mask interrupts with this lock because we're using 110 * trylock here and interrupts are already disabled in the softirq 111 * case. Further, we test the poll_owner to avoid recursion on UP 112 * systems where the lock doesn't exist. 113 * 114 * In cases where there is bi-directional communications, reading only 115 * one message at a time can lead to packets being dropped by the 116 * network adapter, forcing superfluous retries and possibly timeouts. 117 * Thus, we set our budget to greater than 1. 118 */ 119 static int poll_one_napi(struct netpoll_info *npinfo, 120 struct napi_struct *napi, int budget) 121 { 122 int work; 123 124 /* net_rx_action's ->poll() invocations and our's are 125 * synchronized by this test which is only made while 126 * holding the napi->poll_lock. 127 */ 128 if (!test_bit(NAPI_STATE_SCHED, &napi->state)) 129 return budget; 130 131 npinfo->rx_flags |= NETPOLL_RX_DROP; 132 atomic_inc(&trapped); 133 134 work = napi->poll(napi, budget); 135 136 atomic_dec(&trapped); 137 npinfo->rx_flags &= ~NETPOLL_RX_DROP; 138 139 return budget - work; 140 } 141 142 static void poll_napi(struct net_device *dev) 143 { 144 struct napi_struct *napi; 145 int budget = 16; 146 147 list_for_each_entry(napi, &dev->napi_list, dev_list) { 148 if (napi->poll_owner != smp_processor_id() && 149 spin_trylock(&napi->poll_lock)) { 150 budget = poll_one_napi(dev->npinfo, napi, budget); 151 spin_unlock(&napi->poll_lock); 152 153 if (!budget) 154 break; 155 } 156 } 157 } 158 159 static void service_arp_queue(struct netpoll_info *npi) 160 { 161 if (npi) { 162 struct sk_buff *skb; 163 164 while ((skb = skb_dequeue(&npi->arp_tx))) 165 arp_reply(skb); 166 } 167 } 168 169 void netpoll_poll(struct netpoll *np) 170 { 171 struct net_device *dev = np->dev; 172 173 if (!dev || !netif_running(dev) || !dev->poll_controller) 174 return; 175 176 /* Process pending work on NIC */ 177 dev->poll_controller(dev); 178 179 poll_napi(dev); 180 181 service_arp_queue(dev->npinfo); 182 183 zap_completion_queue(); 184 } 185 186 static void refill_skbs(void) 187 { 188 struct sk_buff *skb; 189 unsigned long flags; 190 191 spin_lock_irqsave(&skb_pool.lock, flags); 192 while (skb_pool.qlen < MAX_SKBS) { 193 skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC); 194 if (!skb) 195 break; 196 197 __skb_queue_tail(&skb_pool, skb); 198 } 199 spin_unlock_irqrestore(&skb_pool.lock, flags); 200 } 201 202 static void zap_completion_queue(void) 203 { 204 unsigned long flags; 205 struct softnet_data *sd = &get_cpu_var(softnet_data); 206 207 if (sd->completion_queue) { 208 struct sk_buff *clist; 209 210 local_irq_save(flags); 211 clist = sd->completion_queue; 212 sd->completion_queue = NULL; 213 local_irq_restore(flags); 214 215 while (clist != NULL) { 216 struct sk_buff *skb = clist; 217 clist = clist->next; 218 if (skb->destructor) { 219 atomic_inc(&skb->users); 220 dev_kfree_skb_any(skb); /* put this one back */ 221 } else { 222 __kfree_skb(skb); 223 } 224 } 225 } 226 227 put_cpu_var(softnet_data); 228 } 229 230 static struct sk_buff *find_skb(struct netpoll *np, int len, int reserve) 231 { 232 int count = 0; 233 struct sk_buff *skb; 234 235 zap_completion_queue(); 236 refill_skbs(); 237 repeat: 238 239 skb = alloc_skb(len, GFP_ATOMIC); 240 if (!skb) 241 skb = skb_dequeue(&skb_pool); 242 243 if (!skb) { 244 if (++count < 10) { 245 netpoll_poll(np); 246 goto repeat; 247 } 248 return NULL; 249 } 250 251 atomic_set(&skb->users, 1); 252 skb_reserve(skb, reserve); 253 return skb; 254 } 255 256 static int netpoll_owner_active(struct net_device *dev) 257 { 258 struct napi_struct *napi; 259 260 list_for_each_entry(napi, &dev->napi_list, dev_list) { 261 if (napi->poll_owner == smp_processor_id()) 262 return 1; 263 } 264 return 0; 265 } 266 267 static void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb) 268 { 269 int status = NETDEV_TX_BUSY; 270 unsigned long tries; 271 struct net_device *dev = np->dev; 272 struct netpoll_info *npinfo = np->dev->npinfo; 273 274 if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) { 275 __kfree_skb(skb); 276 return; 277 } 278 279 /* don't get messages out of order, and no recursion */ 280 if (skb_queue_len(&npinfo->txq) == 0 && !netpoll_owner_active(dev)) { 281 unsigned long flags; 282 283 local_irq_save(flags); 284 /* try until next clock tick */ 285 for (tries = jiffies_to_usecs(1)/USEC_PER_POLL; 286 tries > 0; --tries) { 287 if (netif_tx_trylock(dev)) { 288 if (!netif_queue_stopped(dev) && 289 !netif_subqueue_stopped(dev, skb)) 290 status = dev->hard_start_xmit(skb, dev); 291 netif_tx_unlock(dev); 292 293 if (status == NETDEV_TX_OK) 294 break; 295 296 } 297 298 /* tickle device maybe there is some cleanup */ 299 netpoll_poll(np); 300 301 udelay(USEC_PER_POLL); 302 } 303 local_irq_restore(flags); 304 } 305 306 if (status != NETDEV_TX_OK) { 307 skb_queue_tail(&npinfo->txq, skb); 308 schedule_delayed_work(&npinfo->tx_work,0); 309 } 310 } 311 312 void netpoll_send_udp(struct netpoll *np, const char *msg, int len) 313 { 314 int total_len, eth_len, ip_len, udp_len; 315 struct sk_buff *skb; 316 struct udphdr *udph; 317 struct iphdr *iph; 318 struct ethhdr *eth; 319 320 udp_len = len + sizeof(*udph); 321 ip_len = eth_len = udp_len + sizeof(*iph); 322 total_len = eth_len + ETH_HLEN + NET_IP_ALIGN; 323 324 skb = find_skb(np, total_len, total_len - len); 325 if (!skb) 326 return; 327 328 skb_copy_to_linear_data(skb, msg, len); 329 skb->len += len; 330 331 skb_push(skb, sizeof(*udph)); 332 skb_reset_transport_header(skb); 333 udph = udp_hdr(skb); 334 udph->source = htons(np->local_port); 335 udph->dest = htons(np->remote_port); 336 udph->len = htons(udp_len); 337 udph->check = 0; 338 udph->check = csum_tcpudp_magic(htonl(np->local_ip), 339 htonl(np->remote_ip), 340 udp_len, IPPROTO_UDP, 341 csum_partial((unsigned char *)udph, udp_len, 0)); 342 if (udph->check == 0) 343 udph->check = CSUM_MANGLED_0; 344 345 skb_push(skb, sizeof(*iph)); 346 skb_reset_network_header(skb); 347 iph = ip_hdr(skb); 348 349 /* iph->version = 4; iph->ihl = 5; */ 350 put_unaligned(0x45, (unsigned char *)iph); 351 iph->tos = 0; 352 put_unaligned(htons(ip_len), &(iph->tot_len)); 353 iph->id = 0; 354 iph->frag_off = 0; 355 iph->ttl = 64; 356 iph->protocol = IPPROTO_UDP; 357 iph->check = 0; 358 put_unaligned(htonl(np->local_ip), &(iph->saddr)); 359 put_unaligned(htonl(np->remote_ip), &(iph->daddr)); 360 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); 361 362 eth = (struct ethhdr *) skb_push(skb, ETH_HLEN); 363 skb_reset_mac_header(skb); 364 skb->protocol = eth->h_proto = htons(ETH_P_IP); 365 memcpy(eth->h_source, np->dev->dev_addr, ETH_ALEN); 366 memcpy(eth->h_dest, np->remote_mac, ETH_ALEN); 367 368 skb->dev = np->dev; 369 370 netpoll_send_skb(np, skb); 371 } 372 373 static void arp_reply(struct sk_buff *skb) 374 { 375 struct netpoll_info *npinfo = skb->dev->npinfo; 376 struct arphdr *arp; 377 unsigned char *arp_ptr; 378 int size, type = ARPOP_REPLY, ptype = ETH_P_ARP; 379 __be32 sip, tip; 380 unsigned char *sha; 381 struct sk_buff *send_skb; 382 struct netpoll *np = NULL; 383 384 if (npinfo->rx_np && npinfo->rx_np->dev == skb->dev) 385 np = npinfo->rx_np; 386 if (!np) 387 return; 388 389 /* No arp on this interface */ 390 if (skb->dev->flags & IFF_NOARP) 391 return; 392 393 if (!pskb_may_pull(skb, (sizeof(struct arphdr) + 394 (2 * skb->dev->addr_len) + 395 (2 * sizeof(u32))))) 396 return; 397 398 skb_reset_network_header(skb); 399 skb_reset_transport_header(skb); 400 arp = arp_hdr(skb); 401 402 if ((arp->ar_hrd != htons(ARPHRD_ETHER) && 403 arp->ar_hrd != htons(ARPHRD_IEEE802)) || 404 arp->ar_pro != htons(ETH_P_IP) || 405 arp->ar_op != htons(ARPOP_REQUEST)) 406 return; 407 408 arp_ptr = (unsigned char *)(arp+1); 409 /* save the location of the src hw addr */ 410 sha = arp_ptr; 411 arp_ptr += skb->dev->addr_len; 412 memcpy(&sip, arp_ptr, 4); 413 arp_ptr += 4; 414 /* if we actually cared about dst hw addr, it would get copied here */ 415 arp_ptr += skb->dev->addr_len; 416 memcpy(&tip, arp_ptr, 4); 417 418 /* Should we ignore arp? */ 419 if (tip != htonl(np->local_ip) || 420 ipv4_is_loopback(tip) || ipv4_is_multicast(tip)) 421 return; 422 423 size = sizeof(struct arphdr) + 2 * (skb->dev->addr_len + 4); 424 send_skb = find_skb(np, size + LL_RESERVED_SPACE(np->dev), 425 LL_RESERVED_SPACE(np->dev)); 426 427 if (!send_skb) 428 return; 429 430 skb_reset_network_header(send_skb); 431 arp = (struct arphdr *) skb_put(send_skb, size); 432 send_skb->dev = skb->dev; 433 send_skb->protocol = htons(ETH_P_ARP); 434 435 /* Fill the device header for the ARP frame */ 436 if (dev_hard_header(send_skb, skb->dev, ptype, 437 sha, np->dev->dev_addr, 438 send_skb->len) < 0) { 439 kfree_skb(send_skb); 440 return; 441 } 442 443 /* 444 * Fill out the arp protocol part. 445 * 446 * we only support ethernet device type, 447 * which (according to RFC 1390) should always equal 1 (Ethernet). 448 */ 449 450 arp->ar_hrd = htons(np->dev->type); 451 arp->ar_pro = htons(ETH_P_IP); 452 arp->ar_hln = np->dev->addr_len; 453 arp->ar_pln = 4; 454 arp->ar_op = htons(type); 455 456 arp_ptr=(unsigned char *)(arp + 1); 457 memcpy(arp_ptr, np->dev->dev_addr, np->dev->addr_len); 458 arp_ptr += np->dev->addr_len; 459 memcpy(arp_ptr, &tip, 4); 460 arp_ptr += 4; 461 memcpy(arp_ptr, sha, np->dev->addr_len); 462 arp_ptr += np->dev->addr_len; 463 memcpy(arp_ptr, &sip, 4); 464 465 netpoll_send_skb(np, send_skb); 466 } 467 468 int __netpoll_rx(struct sk_buff *skb) 469 { 470 int proto, len, ulen; 471 struct iphdr *iph; 472 struct udphdr *uh; 473 struct netpoll_info *npi = skb->dev->npinfo; 474 struct netpoll *np = npi->rx_np; 475 476 if (!np) 477 goto out; 478 if (skb->dev->type != ARPHRD_ETHER) 479 goto out; 480 481 /* check if netpoll clients need ARP */ 482 if (skb->protocol == htons(ETH_P_ARP) && 483 atomic_read(&trapped)) { 484 skb_queue_tail(&npi->arp_tx, skb); 485 return 1; 486 } 487 488 proto = ntohs(eth_hdr(skb)->h_proto); 489 if (proto != ETH_P_IP) 490 goto out; 491 if (skb->pkt_type == PACKET_OTHERHOST) 492 goto out; 493 if (skb_shared(skb)) 494 goto out; 495 496 iph = (struct iphdr *)skb->data; 497 if (!pskb_may_pull(skb, sizeof(struct iphdr))) 498 goto out; 499 if (iph->ihl < 5 || iph->version != 4) 500 goto out; 501 if (!pskb_may_pull(skb, iph->ihl*4)) 502 goto out; 503 if (ip_fast_csum((u8 *)iph, iph->ihl) != 0) 504 goto out; 505 506 len = ntohs(iph->tot_len); 507 if (skb->len < len || len < iph->ihl*4) 508 goto out; 509 510 /* 511 * Our transport medium may have padded the buffer out. 512 * Now We trim to the true length of the frame. 513 */ 514 if (pskb_trim_rcsum(skb, len)) 515 goto out; 516 517 if (iph->protocol != IPPROTO_UDP) 518 goto out; 519 520 len -= iph->ihl*4; 521 uh = (struct udphdr *)(((char *)iph) + iph->ihl*4); 522 ulen = ntohs(uh->len); 523 524 if (ulen != len) 525 goto out; 526 if (checksum_udp(skb, uh, ulen, iph->saddr, iph->daddr)) 527 goto out; 528 if (np->local_ip && np->local_ip != ntohl(iph->daddr)) 529 goto out; 530 if (np->remote_ip && np->remote_ip != ntohl(iph->saddr)) 531 goto out; 532 if (np->local_port && np->local_port != ntohs(uh->dest)) 533 goto out; 534 535 np->rx_hook(np, ntohs(uh->source), 536 (char *)(uh+1), 537 ulen - sizeof(struct udphdr)); 538 539 kfree_skb(skb); 540 return 1; 541 542 out: 543 if (atomic_read(&trapped)) { 544 kfree_skb(skb); 545 return 1; 546 } 547 548 return 0; 549 } 550 551 void netpoll_print_options(struct netpoll *np) 552 { 553 DECLARE_MAC_BUF(mac); 554 printk(KERN_INFO "%s: local port %d\n", 555 np->name, np->local_port); 556 printk(KERN_INFO "%s: local IP %d.%d.%d.%d\n", 557 np->name, HIPQUAD(np->local_ip)); 558 printk(KERN_INFO "%s: interface %s\n", 559 np->name, np->dev_name); 560 printk(KERN_INFO "%s: remote port %d\n", 561 np->name, np->remote_port); 562 printk(KERN_INFO "%s: remote IP %d.%d.%d.%d\n", 563 np->name, HIPQUAD(np->remote_ip)); 564 printk(KERN_INFO "%s: remote ethernet address %s\n", 565 np->name, print_mac(mac, np->remote_mac)); 566 } 567 568 int netpoll_parse_options(struct netpoll *np, char *opt) 569 { 570 char *cur=opt, *delim; 571 572 if (*cur != '@') { 573 if ((delim = strchr(cur, '@')) == NULL) 574 goto parse_failed; 575 *delim = 0; 576 np->local_port = simple_strtol(cur, NULL, 10); 577 cur = delim; 578 } 579 cur++; 580 581 if (*cur != '/') { 582 if ((delim = strchr(cur, '/')) == NULL) 583 goto parse_failed; 584 *delim = 0; 585 np->local_ip = ntohl(in_aton(cur)); 586 cur = delim; 587 } 588 cur++; 589 590 if (*cur != ',') { 591 /* parse out dev name */ 592 if ((delim = strchr(cur, ',')) == NULL) 593 goto parse_failed; 594 *delim = 0; 595 strlcpy(np->dev_name, cur, sizeof(np->dev_name)); 596 cur = delim; 597 } 598 cur++; 599 600 if (*cur != '@') { 601 /* dst port */ 602 if ((delim = strchr(cur, '@')) == NULL) 603 goto parse_failed; 604 *delim = 0; 605 np->remote_port = simple_strtol(cur, NULL, 10); 606 cur = delim; 607 } 608 cur++; 609 610 /* dst ip */ 611 if ((delim = strchr(cur, '/')) == NULL) 612 goto parse_failed; 613 *delim = 0; 614 np->remote_ip = ntohl(in_aton(cur)); 615 cur = delim + 1; 616 617 if (*cur != 0) { 618 /* MAC address */ 619 if ((delim = strchr(cur, ':')) == NULL) 620 goto parse_failed; 621 *delim = 0; 622 np->remote_mac[0] = simple_strtol(cur, NULL, 16); 623 cur = delim + 1; 624 if ((delim = strchr(cur, ':')) == NULL) 625 goto parse_failed; 626 *delim = 0; 627 np->remote_mac[1] = simple_strtol(cur, NULL, 16); 628 cur = delim + 1; 629 if ((delim = strchr(cur, ':')) == NULL) 630 goto parse_failed; 631 *delim = 0; 632 np->remote_mac[2] = simple_strtol(cur, NULL, 16); 633 cur = delim + 1; 634 if ((delim = strchr(cur, ':')) == NULL) 635 goto parse_failed; 636 *delim = 0; 637 np->remote_mac[3] = simple_strtol(cur, NULL, 16); 638 cur = delim + 1; 639 if ((delim = strchr(cur, ':')) == NULL) 640 goto parse_failed; 641 *delim = 0; 642 np->remote_mac[4] = simple_strtol(cur, NULL, 16); 643 cur = delim + 1; 644 np->remote_mac[5] = simple_strtol(cur, NULL, 16); 645 } 646 647 netpoll_print_options(np); 648 649 return 0; 650 651 parse_failed: 652 printk(KERN_INFO "%s: couldn't parse config at %s!\n", 653 np->name, cur); 654 return -1; 655 } 656 657 int netpoll_setup(struct netpoll *np) 658 { 659 struct net_device *ndev = NULL; 660 struct in_device *in_dev; 661 struct netpoll_info *npinfo; 662 unsigned long flags; 663 int err; 664 665 if (np->dev_name) 666 ndev = dev_get_by_name(&init_net, np->dev_name); 667 if (!ndev) { 668 printk(KERN_ERR "%s: %s doesn't exist, aborting.\n", 669 np->name, np->dev_name); 670 return -ENODEV; 671 } 672 673 np->dev = ndev; 674 if (!ndev->npinfo) { 675 npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL); 676 if (!npinfo) { 677 err = -ENOMEM; 678 goto release; 679 } 680 681 npinfo->rx_flags = 0; 682 npinfo->rx_np = NULL; 683 684 spin_lock_init(&npinfo->rx_lock); 685 skb_queue_head_init(&npinfo->arp_tx); 686 skb_queue_head_init(&npinfo->txq); 687 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process); 688 689 atomic_set(&npinfo->refcnt, 1); 690 } else { 691 npinfo = ndev->npinfo; 692 atomic_inc(&npinfo->refcnt); 693 } 694 695 if (!ndev->poll_controller) { 696 printk(KERN_ERR "%s: %s doesn't support polling, aborting.\n", 697 np->name, np->dev_name); 698 err = -ENOTSUPP; 699 goto release; 700 } 701 702 if (!netif_running(ndev)) { 703 unsigned long atmost, atleast; 704 705 printk(KERN_INFO "%s: device %s not up yet, forcing it\n", 706 np->name, np->dev_name); 707 708 rtnl_lock(); 709 err = dev_open(ndev); 710 rtnl_unlock(); 711 712 if (err) { 713 printk(KERN_ERR "%s: failed to open %s\n", 714 np->name, ndev->name); 715 goto release; 716 } 717 718 atleast = jiffies + HZ/10; 719 atmost = jiffies + 4*HZ; 720 while (!netif_carrier_ok(ndev)) { 721 if (time_after(jiffies, atmost)) { 722 printk(KERN_NOTICE 723 "%s: timeout waiting for carrier\n", 724 np->name); 725 break; 726 } 727 cond_resched(); 728 } 729 730 /* If carrier appears to come up instantly, we don't 731 * trust it and pause so that we don't pump all our 732 * queued console messages into the bitbucket. 733 */ 734 735 if (time_before(jiffies, atleast)) { 736 printk(KERN_NOTICE "%s: carrier detect appears" 737 " untrustworthy, waiting 4 seconds\n", 738 np->name); 739 msleep(4000); 740 } 741 } 742 743 if (!np->local_ip) { 744 rcu_read_lock(); 745 in_dev = __in_dev_get_rcu(ndev); 746 747 if (!in_dev || !in_dev->ifa_list) { 748 rcu_read_unlock(); 749 printk(KERN_ERR "%s: no IP address for %s, aborting\n", 750 np->name, np->dev_name); 751 err = -EDESTADDRREQ; 752 goto release; 753 } 754 755 np->local_ip = ntohl(in_dev->ifa_list->ifa_local); 756 rcu_read_unlock(); 757 printk(KERN_INFO "%s: local IP %d.%d.%d.%d\n", 758 np->name, HIPQUAD(np->local_ip)); 759 } 760 761 if (np->rx_hook) { 762 spin_lock_irqsave(&npinfo->rx_lock, flags); 763 npinfo->rx_flags |= NETPOLL_RX_ENABLED; 764 npinfo->rx_np = np; 765 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 766 } 767 768 /* fill up the skb queue */ 769 refill_skbs(); 770 771 /* last thing to do is link it to the net device structure */ 772 ndev->npinfo = npinfo; 773 774 /* avoid racing with NAPI reading npinfo */ 775 synchronize_rcu(); 776 777 return 0; 778 779 release: 780 if (!ndev->npinfo) 781 kfree(npinfo); 782 np->dev = NULL; 783 dev_put(ndev); 784 return err; 785 } 786 787 static int __init netpoll_init(void) 788 { 789 skb_queue_head_init(&skb_pool); 790 return 0; 791 } 792 core_initcall(netpoll_init); 793 794 void netpoll_cleanup(struct netpoll *np) 795 { 796 struct netpoll_info *npinfo; 797 unsigned long flags; 798 799 if (np->dev) { 800 npinfo = np->dev->npinfo; 801 if (npinfo) { 802 if (npinfo->rx_np == np) { 803 spin_lock_irqsave(&npinfo->rx_lock, flags); 804 npinfo->rx_np = NULL; 805 npinfo->rx_flags &= ~NETPOLL_RX_ENABLED; 806 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 807 } 808 809 if (atomic_dec_and_test(&npinfo->refcnt)) { 810 skb_queue_purge(&npinfo->arp_tx); 811 skb_queue_purge(&npinfo->txq); 812 cancel_rearming_delayed_work(&npinfo->tx_work); 813 814 /* clean after last, unfinished work */ 815 __skb_queue_purge(&npinfo->txq); 816 kfree(npinfo); 817 np->dev->npinfo = NULL; 818 } 819 } 820 821 dev_put(np->dev); 822 } 823 824 np->dev = NULL; 825 } 826 827 int netpoll_trap(void) 828 { 829 return atomic_read(&trapped); 830 } 831 832 void netpoll_set_trap(int trap) 833 { 834 if (trap) 835 atomic_inc(&trapped); 836 else 837 atomic_dec(&trapped); 838 } 839 840 EXPORT_SYMBOL(netpoll_set_trap); 841 EXPORT_SYMBOL(netpoll_trap); 842 EXPORT_SYMBOL(netpoll_print_options); 843 EXPORT_SYMBOL(netpoll_parse_options); 844 EXPORT_SYMBOL(netpoll_setup); 845 EXPORT_SYMBOL(netpoll_cleanup); 846 EXPORT_SYMBOL(netpoll_send_udp); 847 EXPORT_SYMBOL(netpoll_poll); 848