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