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->queue_mapping)) || 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 void poll_napi(struct netpoll *np) 120 { 121 struct netpoll_info *npinfo = np->dev->npinfo; 122 int budget = 16; 123 124 if (test_bit(__LINK_STATE_RX_SCHED, &np->dev->state) && 125 npinfo->poll_owner != smp_processor_id() && 126 spin_trylock(&npinfo->poll_lock)) { 127 npinfo->rx_flags |= NETPOLL_RX_DROP; 128 atomic_inc(&trapped); 129 130 np->dev->poll(np->dev, &budget); 131 132 atomic_dec(&trapped); 133 npinfo->rx_flags &= ~NETPOLL_RX_DROP; 134 spin_unlock(&npinfo->poll_lock); 135 } 136 } 137 138 static void service_arp_queue(struct netpoll_info *npi) 139 { 140 struct sk_buff *skb; 141 142 if (unlikely(!npi)) 143 return; 144 145 skb = skb_dequeue(&npi->arp_tx); 146 147 while (skb != NULL) { 148 arp_reply(skb); 149 skb = skb_dequeue(&npi->arp_tx); 150 } 151 } 152 153 void netpoll_poll(struct netpoll *np) 154 { 155 if (!np->dev || !netif_running(np->dev) || !np->dev->poll_controller) 156 return; 157 158 /* Process pending work on NIC */ 159 np->dev->poll_controller(np->dev); 160 if (np->dev->poll) 161 poll_napi(np); 162 163 service_arp_queue(np->dev->npinfo); 164 165 zap_completion_queue(); 166 } 167 168 static void refill_skbs(void) 169 { 170 struct sk_buff *skb; 171 unsigned long flags; 172 173 spin_lock_irqsave(&skb_pool.lock, flags); 174 while (skb_pool.qlen < MAX_SKBS) { 175 skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC); 176 if (!skb) 177 break; 178 179 __skb_queue_tail(&skb_pool, skb); 180 } 181 spin_unlock_irqrestore(&skb_pool.lock, flags); 182 } 183 184 static void zap_completion_queue(void) 185 { 186 unsigned long flags; 187 struct softnet_data *sd = &get_cpu_var(softnet_data); 188 189 if (sd->completion_queue) { 190 struct sk_buff *clist; 191 192 local_irq_save(flags); 193 clist = sd->completion_queue; 194 sd->completion_queue = NULL; 195 local_irq_restore(flags); 196 197 while (clist != NULL) { 198 struct sk_buff *skb = clist; 199 clist = clist->next; 200 if (skb->destructor) 201 dev_kfree_skb_any(skb); /* put this one back */ 202 else 203 __kfree_skb(skb); 204 } 205 } 206 207 put_cpu_var(softnet_data); 208 } 209 210 static struct sk_buff *find_skb(struct netpoll *np, int len, int reserve) 211 { 212 int count = 0; 213 struct sk_buff *skb; 214 215 zap_completion_queue(); 216 refill_skbs(); 217 repeat: 218 219 skb = alloc_skb(len, GFP_ATOMIC); 220 if (!skb) 221 skb = skb_dequeue(&skb_pool); 222 223 if (!skb) { 224 if (++count < 10) { 225 netpoll_poll(np); 226 goto repeat; 227 } 228 return NULL; 229 } 230 231 atomic_set(&skb->users, 1); 232 skb_reserve(skb, reserve); 233 return skb; 234 } 235 236 static void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb) 237 { 238 int status = NETDEV_TX_BUSY; 239 unsigned long tries; 240 struct net_device *dev = np->dev; 241 struct netpoll_info *npinfo = np->dev->npinfo; 242 243 if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) { 244 __kfree_skb(skb); 245 return; 246 } 247 248 /* don't get messages out of order, and no recursion */ 249 if (skb_queue_len(&npinfo->txq) == 0 && 250 npinfo->poll_owner != smp_processor_id()) { 251 unsigned long flags; 252 253 local_irq_save(flags); 254 /* try until next clock tick */ 255 for (tries = jiffies_to_usecs(1)/USEC_PER_POLL; 256 tries > 0; --tries) { 257 if (netif_tx_trylock(dev)) { 258 if (!netif_queue_stopped(dev) && 259 !netif_subqueue_stopped(dev, skb->queue_mapping)) 260 status = dev->hard_start_xmit(skb, dev); 261 netif_tx_unlock(dev); 262 263 if (status == NETDEV_TX_OK) 264 break; 265 266 } 267 268 /* tickle device maybe there is some cleanup */ 269 netpoll_poll(np); 270 271 udelay(USEC_PER_POLL); 272 } 273 local_irq_restore(flags); 274 } 275 276 if (status != NETDEV_TX_OK) { 277 skb_queue_tail(&npinfo->txq, skb); 278 schedule_delayed_work(&npinfo->tx_work,0); 279 } 280 } 281 282 void netpoll_send_udp(struct netpoll *np, const char *msg, int len) 283 { 284 int total_len, eth_len, ip_len, udp_len; 285 struct sk_buff *skb; 286 struct udphdr *udph; 287 struct iphdr *iph; 288 struct ethhdr *eth; 289 290 udp_len = len + sizeof(*udph); 291 ip_len = eth_len = udp_len + sizeof(*iph); 292 total_len = eth_len + ETH_HLEN + NET_IP_ALIGN; 293 294 skb = find_skb(np, total_len, total_len - len); 295 if (!skb) 296 return; 297 298 skb_copy_to_linear_data(skb, msg, len); 299 skb->len += len; 300 301 skb_push(skb, sizeof(*udph)); 302 skb_reset_transport_header(skb); 303 udph = udp_hdr(skb); 304 udph->source = htons(np->local_port); 305 udph->dest = htons(np->remote_port); 306 udph->len = htons(udp_len); 307 udph->check = 0; 308 udph->check = csum_tcpudp_magic(htonl(np->local_ip), 309 htonl(np->remote_ip), 310 udp_len, IPPROTO_UDP, 311 csum_partial((unsigned char *)udph, udp_len, 0)); 312 if (udph->check == 0) 313 udph->check = CSUM_MANGLED_0; 314 315 skb_push(skb, sizeof(*iph)); 316 skb_reset_network_header(skb); 317 iph = ip_hdr(skb); 318 319 /* iph->version = 4; iph->ihl = 5; */ 320 put_unaligned(0x45, (unsigned char *)iph); 321 iph->tos = 0; 322 put_unaligned(htons(ip_len), &(iph->tot_len)); 323 iph->id = 0; 324 iph->frag_off = 0; 325 iph->ttl = 64; 326 iph->protocol = IPPROTO_UDP; 327 iph->check = 0; 328 put_unaligned(htonl(np->local_ip), &(iph->saddr)); 329 put_unaligned(htonl(np->remote_ip), &(iph->daddr)); 330 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); 331 332 eth = (struct ethhdr *) skb_push(skb, ETH_HLEN); 333 skb_reset_mac_header(skb); 334 skb->protocol = eth->h_proto = htons(ETH_P_IP); 335 memcpy(eth->h_source, np->local_mac, 6); 336 memcpy(eth->h_dest, np->remote_mac, 6); 337 338 skb->dev = np->dev; 339 340 netpoll_send_skb(np, skb); 341 } 342 343 static void arp_reply(struct sk_buff *skb) 344 { 345 struct netpoll_info *npinfo = skb->dev->npinfo; 346 struct arphdr *arp; 347 unsigned char *arp_ptr; 348 int size, type = ARPOP_REPLY, ptype = ETH_P_ARP; 349 __be32 sip, tip; 350 unsigned char *sha; 351 struct sk_buff *send_skb; 352 struct netpoll *np = NULL; 353 354 if (npinfo->rx_np && npinfo->rx_np->dev == skb->dev) 355 np = npinfo->rx_np; 356 if (!np) 357 return; 358 359 /* No arp on this interface */ 360 if (skb->dev->flags & IFF_NOARP) 361 return; 362 363 if (!pskb_may_pull(skb, (sizeof(struct arphdr) + 364 (2 * skb->dev->addr_len) + 365 (2 * sizeof(u32))))) 366 return; 367 368 skb_reset_network_header(skb); 369 skb_reset_transport_header(skb); 370 arp = arp_hdr(skb); 371 372 if ((arp->ar_hrd != htons(ARPHRD_ETHER) && 373 arp->ar_hrd != htons(ARPHRD_IEEE802)) || 374 arp->ar_pro != htons(ETH_P_IP) || 375 arp->ar_op != htons(ARPOP_REQUEST)) 376 return; 377 378 arp_ptr = (unsigned char *)(arp+1); 379 /* save the location of the src hw addr */ 380 sha = arp_ptr; 381 arp_ptr += skb->dev->addr_len; 382 memcpy(&sip, arp_ptr, 4); 383 arp_ptr += 4; 384 /* if we actually cared about dst hw addr, it would get copied here */ 385 arp_ptr += skb->dev->addr_len; 386 memcpy(&tip, arp_ptr, 4); 387 388 /* Should we ignore arp? */ 389 if (tip != htonl(np->local_ip) || LOOPBACK(tip) || MULTICAST(tip)) 390 return; 391 392 size = sizeof(struct arphdr) + 2 * (skb->dev->addr_len + 4); 393 send_skb = find_skb(np, size + LL_RESERVED_SPACE(np->dev), 394 LL_RESERVED_SPACE(np->dev)); 395 396 if (!send_skb) 397 return; 398 399 skb_reset_network_header(send_skb); 400 arp = (struct arphdr *) skb_put(send_skb, size); 401 send_skb->dev = skb->dev; 402 send_skb->protocol = htons(ETH_P_ARP); 403 404 /* Fill the device header for the ARP frame */ 405 406 if (np->dev->hard_header && 407 np->dev->hard_header(send_skb, skb->dev, ptype, 408 sha, np->local_mac, 409 send_skb->len) < 0) { 410 kfree_skb(send_skb); 411 return; 412 } 413 414 /* 415 * Fill out the arp protocol part. 416 * 417 * we only support ethernet device type, 418 * which (according to RFC 1390) should always equal 1 (Ethernet). 419 */ 420 421 arp->ar_hrd = htons(np->dev->type); 422 arp->ar_pro = htons(ETH_P_IP); 423 arp->ar_hln = np->dev->addr_len; 424 arp->ar_pln = 4; 425 arp->ar_op = htons(type); 426 427 arp_ptr=(unsigned char *)(arp + 1); 428 memcpy(arp_ptr, np->dev->dev_addr, np->dev->addr_len); 429 arp_ptr += np->dev->addr_len; 430 memcpy(arp_ptr, &tip, 4); 431 arp_ptr += 4; 432 memcpy(arp_ptr, sha, np->dev->addr_len); 433 arp_ptr += np->dev->addr_len; 434 memcpy(arp_ptr, &sip, 4); 435 436 netpoll_send_skb(np, send_skb); 437 } 438 439 int __netpoll_rx(struct sk_buff *skb) 440 { 441 int proto, len, ulen; 442 struct iphdr *iph; 443 struct udphdr *uh; 444 struct netpoll_info *npi = skb->dev->npinfo; 445 struct netpoll *np = npi->rx_np; 446 447 if (!np) 448 goto out; 449 if (skb->dev->type != ARPHRD_ETHER) 450 goto out; 451 452 /* check if netpoll clients need ARP */ 453 if (skb->protocol == htons(ETH_P_ARP) && 454 atomic_read(&trapped)) { 455 skb_queue_tail(&npi->arp_tx, skb); 456 return 1; 457 } 458 459 proto = ntohs(eth_hdr(skb)->h_proto); 460 if (proto != ETH_P_IP) 461 goto out; 462 if (skb->pkt_type == PACKET_OTHERHOST) 463 goto out; 464 if (skb_shared(skb)) 465 goto out; 466 467 iph = (struct iphdr *)skb->data; 468 if (!pskb_may_pull(skb, sizeof(struct iphdr))) 469 goto out; 470 if (iph->ihl < 5 || iph->version != 4) 471 goto out; 472 if (!pskb_may_pull(skb, iph->ihl*4)) 473 goto out; 474 if (ip_fast_csum((u8 *)iph, iph->ihl) != 0) 475 goto out; 476 477 len = ntohs(iph->tot_len); 478 if (skb->len < len || len < iph->ihl*4) 479 goto out; 480 481 /* 482 * Our transport medium may have padded the buffer out. 483 * Now We trim to the true length of the frame. 484 */ 485 if (pskb_trim_rcsum(skb, len)) 486 goto out; 487 488 if (iph->protocol != IPPROTO_UDP) 489 goto out; 490 491 len -= iph->ihl*4; 492 uh = (struct udphdr *)(((char *)iph) + iph->ihl*4); 493 ulen = ntohs(uh->len); 494 495 if (ulen != len) 496 goto out; 497 if (checksum_udp(skb, uh, ulen, iph->saddr, iph->daddr)) 498 goto out; 499 if (np->local_ip && np->local_ip != ntohl(iph->daddr)) 500 goto out; 501 if (np->remote_ip && np->remote_ip != ntohl(iph->saddr)) 502 goto out; 503 if (np->local_port && np->local_port != ntohs(uh->dest)) 504 goto out; 505 506 np->rx_hook(np, ntohs(uh->source), 507 (char *)(uh+1), 508 ulen - sizeof(struct udphdr)); 509 510 kfree_skb(skb); 511 return 1; 512 513 out: 514 if (atomic_read(&trapped)) { 515 kfree_skb(skb); 516 return 1; 517 } 518 519 return 0; 520 } 521 522 int netpoll_parse_options(struct netpoll *np, char *opt) 523 { 524 char *cur=opt, *delim; 525 526 if (*cur != '@') { 527 if ((delim = strchr(cur, '@')) == NULL) 528 goto parse_failed; 529 *delim = 0; 530 np->local_port = simple_strtol(cur, NULL, 10); 531 cur = delim; 532 } 533 cur++; 534 printk(KERN_INFO "%s: local port %d\n", np->name, np->local_port); 535 536 if (*cur != '/') { 537 if ((delim = strchr(cur, '/')) == NULL) 538 goto parse_failed; 539 *delim = 0; 540 np->local_ip = ntohl(in_aton(cur)); 541 cur = delim; 542 543 printk(KERN_INFO "%s: local IP %d.%d.%d.%d\n", 544 np->name, HIPQUAD(np->local_ip)); 545 } 546 cur++; 547 548 if (*cur != ',') { 549 /* parse out dev name */ 550 if ((delim = strchr(cur, ',')) == NULL) 551 goto parse_failed; 552 *delim = 0; 553 strlcpy(np->dev_name, cur, sizeof(np->dev_name)); 554 cur = delim; 555 } 556 cur++; 557 558 printk(KERN_INFO "%s: interface %s\n", np->name, np->dev_name); 559 560 if (*cur != '@') { 561 /* dst port */ 562 if ((delim = strchr(cur, '@')) == NULL) 563 goto parse_failed; 564 *delim = 0; 565 np->remote_port = simple_strtol(cur, NULL, 10); 566 cur = delim; 567 } 568 cur++; 569 printk(KERN_INFO "%s: remote port %d\n", np->name, np->remote_port); 570 571 /* dst ip */ 572 if ((delim = strchr(cur, '/')) == NULL) 573 goto parse_failed; 574 *delim = 0; 575 np->remote_ip = ntohl(in_aton(cur)); 576 cur = delim + 1; 577 578 printk(KERN_INFO "%s: remote IP %d.%d.%d.%d\n", 579 np->name, HIPQUAD(np->remote_ip)); 580 581 if (*cur != 0) { 582 /* MAC address */ 583 if ((delim = strchr(cur, ':')) == NULL) 584 goto parse_failed; 585 *delim = 0; 586 np->remote_mac[0] = simple_strtol(cur, NULL, 16); 587 cur = delim + 1; 588 if ((delim = strchr(cur, ':')) == NULL) 589 goto parse_failed; 590 *delim = 0; 591 np->remote_mac[1] = simple_strtol(cur, NULL, 16); 592 cur = delim + 1; 593 if ((delim = strchr(cur, ':')) == NULL) 594 goto parse_failed; 595 *delim = 0; 596 np->remote_mac[2] = simple_strtol(cur, NULL, 16); 597 cur = delim + 1; 598 if ((delim = strchr(cur, ':')) == NULL) 599 goto parse_failed; 600 *delim = 0; 601 np->remote_mac[3] = simple_strtol(cur, NULL, 16); 602 cur = delim + 1; 603 if ((delim = strchr(cur, ':')) == NULL) 604 goto parse_failed; 605 *delim = 0; 606 np->remote_mac[4] = simple_strtol(cur, NULL, 16); 607 cur = delim + 1; 608 np->remote_mac[5] = simple_strtol(cur, NULL, 16); 609 } 610 611 printk(KERN_INFO "%s: remote ethernet address " 612 "%02x:%02x:%02x:%02x:%02x:%02x\n", 613 np->name, 614 np->remote_mac[0], 615 np->remote_mac[1], 616 np->remote_mac[2], 617 np->remote_mac[3], 618 np->remote_mac[4], 619 np->remote_mac[5]); 620 621 return 0; 622 623 parse_failed: 624 printk(KERN_INFO "%s: couldn't parse config at %s!\n", 625 np->name, cur); 626 return -1; 627 } 628 629 int netpoll_setup(struct netpoll *np) 630 { 631 struct net_device *ndev = NULL; 632 struct in_device *in_dev; 633 struct netpoll_info *npinfo; 634 unsigned long flags; 635 int err; 636 637 if (np->dev_name) 638 ndev = dev_get_by_name(np->dev_name); 639 if (!ndev) { 640 printk(KERN_ERR "%s: %s doesn't exist, aborting.\n", 641 np->name, np->dev_name); 642 return -ENODEV; 643 } 644 645 np->dev = ndev; 646 if (!ndev->npinfo) { 647 npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL); 648 if (!npinfo) { 649 err = -ENOMEM; 650 goto release; 651 } 652 653 npinfo->rx_flags = 0; 654 npinfo->rx_np = NULL; 655 spin_lock_init(&npinfo->poll_lock); 656 npinfo->poll_owner = -1; 657 658 spin_lock_init(&npinfo->rx_lock); 659 skb_queue_head_init(&npinfo->arp_tx); 660 skb_queue_head_init(&npinfo->txq); 661 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process); 662 663 atomic_set(&npinfo->refcnt, 1); 664 } else { 665 npinfo = ndev->npinfo; 666 atomic_inc(&npinfo->refcnt); 667 } 668 669 if (!ndev->poll_controller) { 670 printk(KERN_ERR "%s: %s doesn't support polling, aborting.\n", 671 np->name, np->dev_name); 672 err = -ENOTSUPP; 673 goto release; 674 } 675 676 if (!netif_running(ndev)) { 677 unsigned long atmost, atleast; 678 679 printk(KERN_INFO "%s: device %s not up yet, forcing it\n", 680 np->name, np->dev_name); 681 682 rtnl_lock(); 683 err = dev_open(ndev); 684 rtnl_unlock(); 685 686 if (err) { 687 printk(KERN_ERR "%s: failed to open %s\n", 688 np->name, ndev->name); 689 goto release; 690 } 691 692 atleast = jiffies + HZ/10; 693 atmost = jiffies + 4*HZ; 694 while (!netif_carrier_ok(ndev)) { 695 if (time_after(jiffies, atmost)) { 696 printk(KERN_NOTICE 697 "%s: timeout waiting for carrier\n", 698 np->name); 699 break; 700 } 701 cond_resched(); 702 } 703 704 /* If carrier appears to come up instantly, we don't 705 * trust it and pause so that we don't pump all our 706 * queued console messages into the bitbucket. 707 */ 708 709 if (time_before(jiffies, atleast)) { 710 printk(KERN_NOTICE "%s: carrier detect appears" 711 " untrustworthy, waiting 4 seconds\n", 712 np->name); 713 msleep(4000); 714 } 715 } 716 717 if (is_zero_ether_addr(np->local_mac) && ndev->dev_addr) 718 memcpy(np->local_mac, ndev->dev_addr, 6); 719 720 if (!np->local_ip) { 721 rcu_read_lock(); 722 in_dev = __in_dev_get_rcu(ndev); 723 724 if (!in_dev || !in_dev->ifa_list) { 725 rcu_read_unlock(); 726 printk(KERN_ERR "%s: no IP address for %s, aborting\n", 727 np->name, np->dev_name); 728 err = -EDESTADDRREQ; 729 goto release; 730 } 731 732 np->local_ip = ntohl(in_dev->ifa_list->ifa_local); 733 rcu_read_unlock(); 734 printk(KERN_INFO "%s: local IP %d.%d.%d.%d\n", 735 np->name, HIPQUAD(np->local_ip)); 736 } 737 738 if (np->rx_hook) { 739 spin_lock_irqsave(&npinfo->rx_lock, flags); 740 npinfo->rx_flags |= NETPOLL_RX_ENABLED; 741 npinfo->rx_np = np; 742 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 743 } 744 745 /* fill up the skb queue */ 746 refill_skbs(); 747 748 /* last thing to do is link it to the net device structure */ 749 ndev->npinfo = npinfo; 750 751 /* avoid racing with NAPI reading npinfo */ 752 synchronize_rcu(); 753 754 return 0; 755 756 release: 757 if (!ndev->npinfo) 758 kfree(npinfo); 759 np->dev = NULL; 760 dev_put(ndev); 761 return err; 762 } 763 764 static int __init netpoll_init(void) 765 { 766 skb_queue_head_init(&skb_pool); 767 return 0; 768 } 769 core_initcall(netpoll_init); 770 771 void netpoll_cleanup(struct netpoll *np) 772 { 773 struct netpoll_info *npinfo; 774 unsigned long flags; 775 776 if (np->dev) { 777 npinfo = np->dev->npinfo; 778 if (npinfo) { 779 if (npinfo->rx_np == np) { 780 spin_lock_irqsave(&npinfo->rx_lock, flags); 781 npinfo->rx_np = NULL; 782 npinfo->rx_flags &= ~NETPOLL_RX_ENABLED; 783 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 784 } 785 786 if (atomic_dec_and_test(&npinfo->refcnt)) { 787 skb_queue_purge(&npinfo->arp_tx); 788 skb_queue_purge(&npinfo->txq); 789 cancel_rearming_delayed_work(&npinfo->tx_work); 790 791 /* clean after last, unfinished work */ 792 if (!skb_queue_empty(&npinfo->txq)) { 793 struct sk_buff *skb; 794 skb = __skb_dequeue(&npinfo->txq); 795 kfree_skb(skb); 796 } 797 kfree(npinfo); 798 np->dev->npinfo = NULL; 799 } 800 } 801 802 dev_put(np->dev); 803 } 804 805 np->dev = NULL; 806 } 807 808 int netpoll_trap(void) 809 { 810 return atomic_read(&trapped); 811 } 812 813 void netpoll_set_trap(int trap) 814 { 815 if (trap) 816 atomic_inc(&trapped); 817 else 818 atomic_dec(&trapped); 819 } 820 821 EXPORT_SYMBOL(netpoll_set_trap); 822 EXPORT_SYMBOL(netpoll_trap); 823 EXPORT_SYMBOL(netpoll_parse_options); 824 EXPORT_SYMBOL(netpoll_setup); 825 EXPORT_SYMBOL(netpoll_cleanup); 826 EXPORT_SYMBOL(netpoll_send_udp); 827 EXPORT_SYMBOL(netpoll_poll); 828