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/smp_lock.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 29 /* 30 * We maintain a small pool of fully-sized skbs, to make sure the 31 * message gets out even in extreme OOM situations. 32 */ 33 34 #define MAX_UDP_CHUNK 1460 35 #define MAX_SKBS 32 36 #define MAX_QUEUE_DEPTH (MAX_SKBS / 2) 37 38 static struct sk_buff_head skb_pool; 39 40 static atomic_t trapped; 41 42 #define USEC_PER_POLL 50 43 #define NETPOLL_RX_ENABLED 1 44 #define NETPOLL_RX_DROP 2 45 46 #define MAX_SKB_SIZE \ 47 (MAX_UDP_CHUNK + sizeof(struct udphdr) + \ 48 sizeof(struct iphdr) + sizeof(struct ethhdr)) 49 50 static void zap_completion_queue(void); 51 static void arp_reply(struct sk_buff *skb); 52 53 static void queue_process(struct work_struct *work) 54 { 55 struct netpoll_info *npinfo = 56 container_of(work, struct netpoll_info, tx_work.work); 57 struct sk_buff *skb; 58 unsigned long flags; 59 60 while ((skb = skb_dequeue(&npinfo->txq))) { 61 struct net_device *dev = skb->dev; 62 63 if (!netif_device_present(dev) || !netif_running(dev)) { 64 __kfree_skb(skb); 65 continue; 66 } 67 68 local_irq_save(flags); 69 netif_tx_lock(dev); 70 if (netif_queue_stopped(dev) || 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 if (netif_tx_trylock(dev)) { 255 /* try until next clock tick */ 256 for (tries = jiffies_to_usecs(1)/USEC_PER_POLL; 257 tries > 0; --tries) { 258 if (!netif_queue_stopped(dev)) 259 status = dev->hard_start_xmit(skb, dev); 260 261 if (status == NETDEV_TX_OK) 262 break; 263 264 /* tickle device maybe there is some cleanup */ 265 netpoll_poll(np); 266 267 udelay(USEC_PER_POLL); 268 } 269 netif_tx_unlock(dev); 270 } 271 local_irq_restore(flags); 272 } 273 274 if (status != NETDEV_TX_OK) { 275 skb_queue_tail(&npinfo->txq, skb); 276 schedule_delayed_work(&npinfo->tx_work,0); 277 } 278 } 279 280 void netpoll_send_udp(struct netpoll *np, const char *msg, int len) 281 { 282 int total_len, eth_len, ip_len, udp_len; 283 struct sk_buff *skb; 284 struct udphdr *udph; 285 struct iphdr *iph; 286 struct ethhdr *eth; 287 288 udp_len = len + sizeof(*udph); 289 ip_len = eth_len = udp_len + sizeof(*iph); 290 total_len = eth_len + ETH_HLEN + NET_IP_ALIGN; 291 292 skb = find_skb(np, total_len, total_len - len); 293 if (!skb) 294 return; 295 296 skb_copy_to_linear_data(skb, msg, len); 297 skb->len += len; 298 299 skb_push(skb, sizeof(*udph)); 300 skb_reset_transport_header(skb); 301 udph = udp_hdr(skb); 302 udph->source = htons(np->local_port); 303 udph->dest = htons(np->remote_port); 304 udph->len = htons(udp_len); 305 udph->check = 0; 306 udph->check = csum_tcpudp_magic(htonl(np->local_ip), 307 htonl(np->remote_ip), 308 udp_len, IPPROTO_UDP, 309 csum_partial((unsigned char *)udph, udp_len, 0)); 310 if (udph->check == 0) 311 udph->check = CSUM_MANGLED_0; 312 313 skb_push(skb, sizeof(*iph)); 314 skb_reset_network_header(skb); 315 iph = ip_hdr(skb); 316 317 /* iph->version = 4; iph->ihl = 5; */ 318 put_unaligned(0x45, (unsigned char *)iph); 319 iph->tos = 0; 320 put_unaligned(htons(ip_len), &(iph->tot_len)); 321 iph->id = 0; 322 iph->frag_off = 0; 323 iph->ttl = 64; 324 iph->protocol = IPPROTO_UDP; 325 iph->check = 0; 326 put_unaligned(htonl(np->local_ip), &(iph->saddr)); 327 put_unaligned(htonl(np->remote_ip), &(iph->daddr)); 328 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); 329 330 eth = (struct ethhdr *) skb_push(skb, ETH_HLEN); 331 skb_reset_mac_header(skb); 332 skb->protocol = eth->h_proto = htons(ETH_P_IP); 333 memcpy(eth->h_source, np->local_mac, 6); 334 memcpy(eth->h_dest, np->remote_mac, 6); 335 336 skb->dev = np->dev; 337 338 netpoll_send_skb(np, skb); 339 } 340 341 static void arp_reply(struct sk_buff *skb) 342 { 343 struct netpoll_info *npinfo = skb->dev->npinfo; 344 struct arphdr *arp; 345 unsigned char *arp_ptr; 346 int size, type = ARPOP_REPLY, ptype = ETH_P_ARP; 347 __be32 sip, tip; 348 unsigned char *sha; 349 struct sk_buff *send_skb; 350 struct netpoll *np = NULL; 351 352 if (npinfo->rx_np && npinfo->rx_np->dev == skb->dev) 353 np = npinfo->rx_np; 354 if (!np) 355 return; 356 357 /* No arp on this interface */ 358 if (skb->dev->flags & IFF_NOARP) 359 return; 360 361 if (!pskb_may_pull(skb, (sizeof(struct arphdr) + 362 (2 * skb->dev->addr_len) + 363 (2 * sizeof(u32))))) 364 return; 365 366 skb_reset_network_header(skb); 367 skb_reset_transport_header(skb); 368 arp = arp_hdr(skb); 369 370 if ((arp->ar_hrd != htons(ARPHRD_ETHER) && 371 arp->ar_hrd != htons(ARPHRD_IEEE802)) || 372 arp->ar_pro != htons(ETH_P_IP) || 373 arp->ar_op != htons(ARPOP_REQUEST)) 374 return; 375 376 arp_ptr = (unsigned char *)(arp+1); 377 /* save the location of the src hw addr */ 378 sha = arp_ptr; 379 arp_ptr += skb->dev->addr_len; 380 memcpy(&sip, arp_ptr, 4); 381 arp_ptr += 4; 382 /* if we actually cared about dst hw addr, it would get copied here */ 383 arp_ptr += skb->dev->addr_len; 384 memcpy(&tip, arp_ptr, 4); 385 386 /* Should we ignore arp? */ 387 if (tip != htonl(np->local_ip) || LOOPBACK(tip) || MULTICAST(tip)) 388 return; 389 390 size = sizeof(struct arphdr) + 2 * (skb->dev->addr_len + 4); 391 send_skb = find_skb(np, size + LL_RESERVED_SPACE(np->dev), 392 LL_RESERVED_SPACE(np->dev)); 393 394 if (!send_skb) 395 return; 396 397 skb_reset_network_header(send_skb); 398 arp = (struct arphdr *) skb_put(send_skb, size); 399 send_skb->dev = skb->dev; 400 send_skb->protocol = htons(ETH_P_ARP); 401 402 /* Fill the device header for the ARP frame */ 403 404 if (np->dev->hard_header && 405 np->dev->hard_header(send_skb, skb->dev, ptype, 406 sha, np->local_mac, 407 send_skb->len) < 0) { 408 kfree_skb(send_skb); 409 return; 410 } 411 412 /* 413 * Fill out the arp protocol part. 414 * 415 * we only support ethernet device type, 416 * which (according to RFC 1390) should always equal 1 (Ethernet). 417 */ 418 419 arp->ar_hrd = htons(np->dev->type); 420 arp->ar_pro = htons(ETH_P_IP); 421 arp->ar_hln = np->dev->addr_len; 422 arp->ar_pln = 4; 423 arp->ar_op = htons(type); 424 425 arp_ptr=(unsigned char *)(arp + 1); 426 memcpy(arp_ptr, np->dev->dev_addr, np->dev->addr_len); 427 arp_ptr += np->dev->addr_len; 428 memcpy(arp_ptr, &tip, 4); 429 arp_ptr += 4; 430 memcpy(arp_ptr, sha, np->dev->addr_len); 431 arp_ptr += np->dev->addr_len; 432 memcpy(arp_ptr, &sip, 4); 433 434 netpoll_send_skb(np, send_skb); 435 } 436 437 int __netpoll_rx(struct sk_buff *skb) 438 { 439 int proto, len, ulen; 440 struct iphdr *iph; 441 struct udphdr *uh; 442 struct netpoll_info *npi = skb->dev->npinfo; 443 struct netpoll *np = npi->rx_np; 444 445 if (!np) 446 goto out; 447 if (skb->dev->type != ARPHRD_ETHER) 448 goto out; 449 450 /* check if netpoll clients need ARP */ 451 if (skb->protocol == htons(ETH_P_ARP) && 452 atomic_read(&trapped)) { 453 skb_queue_tail(&npi->arp_tx, skb); 454 return 1; 455 } 456 457 proto = ntohs(eth_hdr(skb)->h_proto); 458 if (proto != ETH_P_IP) 459 goto out; 460 if (skb->pkt_type == PACKET_OTHERHOST) 461 goto out; 462 if (skb_shared(skb)) 463 goto out; 464 465 iph = (struct iphdr *)skb->data; 466 if (!pskb_may_pull(skb, sizeof(struct iphdr))) 467 goto out; 468 if (iph->ihl < 5 || iph->version != 4) 469 goto out; 470 if (!pskb_may_pull(skb, iph->ihl*4)) 471 goto out; 472 if (ip_fast_csum((u8 *)iph, iph->ihl) != 0) 473 goto out; 474 475 len = ntohs(iph->tot_len); 476 if (skb->len < len || len < iph->ihl*4) 477 goto out; 478 479 /* 480 * Our transport medium may have padded the buffer out. 481 * Now We trim to the true length of the frame. 482 */ 483 if (pskb_trim_rcsum(skb, len)) 484 goto out; 485 486 if (iph->protocol != IPPROTO_UDP) 487 goto out; 488 489 len -= iph->ihl*4; 490 uh = (struct udphdr *)(((char *)iph) + iph->ihl*4); 491 ulen = ntohs(uh->len); 492 493 if (ulen != len) 494 goto out; 495 if (checksum_udp(skb, uh, ulen, iph->saddr, iph->daddr)) 496 goto out; 497 if (np->local_ip && np->local_ip != ntohl(iph->daddr)) 498 goto out; 499 if (np->remote_ip && np->remote_ip != ntohl(iph->saddr)) 500 goto out; 501 if (np->local_port && np->local_port != ntohs(uh->dest)) 502 goto out; 503 504 np->rx_hook(np, ntohs(uh->source), 505 (char *)(uh+1), 506 ulen - sizeof(struct udphdr)); 507 508 kfree_skb(skb); 509 return 1; 510 511 out: 512 if (atomic_read(&trapped)) { 513 kfree_skb(skb); 514 return 1; 515 } 516 517 return 0; 518 } 519 520 int netpoll_parse_options(struct netpoll *np, char *opt) 521 { 522 char *cur=opt, *delim; 523 524 if (*cur != '@') { 525 if ((delim = strchr(cur, '@')) == NULL) 526 goto parse_failed; 527 *delim = 0; 528 np->local_port = simple_strtol(cur, NULL, 10); 529 cur = delim; 530 } 531 cur++; 532 printk(KERN_INFO "%s: local port %d\n", np->name, np->local_port); 533 534 if (*cur != '/') { 535 if ((delim = strchr(cur, '/')) == NULL) 536 goto parse_failed; 537 *delim = 0; 538 np->local_ip = ntohl(in_aton(cur)); 539 cur = delim; 540 541 printk(KERN_INFO "%s: local IP %d.%d.%d.%d\n", 542 np->name, HIPQUAD(np->local_ip)); 543 } 544 cur++; 545 546 if (*cur != ',') { 547 /* parse out dev name */ 548 if ((delim = strchr(cur, ',')) == NULL) 549 goto parse_failed; 550 *delim = 0; 551 strlcpy(np->dev_name, cur, sizeof(np->dev_name)); 552 cur = delim; 553 } 554 cur++; 555 556 printk(KERN_INFO "%s: interface %s\n", np->name, np->dev_name); 557 558 if (*cur != '@') { 559 /* dst port */ 560 if ((delim = strchr(cur, '@')) == NULL) 561 goto parse_failed; 562 *delim = 0; 563 np->remote_port = simple_strtol(cur, NULL, 10); 564 cur = delim; 565 } 566 cur++; 567 printk(KERN_INFO "%s: remote port %d\n", np->name, np->remote_port); 568 569 /* dst ip */ 570 if ((delim = strchr(cur, '/')) == NULL) 571 goto parse_failed; 572 *delim = 0; 573 np->remote_ip = ntohl(in_aton(cur)); 574 cur = delim + 1; 575 576 printk(KERN_INFO "%s: remote IP %d.%d.%d.%d\n", 577 np->name, HIPQUAD(np->remote_ip)); 578 579 if (*cur != 0) { 580 /* MAC address */ 581 if ((delim = strchr(cur, ':')) == NULL) 582 goto parse_failed; 583 *delim = 0; 584 np->remote_mac[0] = simple_strtol(cur, NULL, 16); 585 cur = delim + 1; 586 if ((delim = strchr(cur, ':')) == NULL) 587 goto parse_failed; 588 *delim = 0; 589 np->remote_mac[1] = simple_strtol(cur, NULL, 16); 590 cur = delim + 1; 591 if ((delim = strchr(cur, ':')) == NULL) 592 goto parse_failed; 593 *delim = 0; 594 np->remote_mac[2] = simple_strtol(cur, NULL, 16); 595 cur = delim + 1; 596 if ((delim = strchr(cur, ':')) == NULL) 597 goto parse_failed; 598 *delim = 0; 599 np->remote_mac[3] = simple_strtol(cur, NULL, 16); 600 cur = delim + 1; 601 if ((delim = strchr(cur, ':')) == NULL) 602 goto parse_failed; 603 *delim = 0; 604 np->remote_mac[4] = simple_strtol(cur, NULL, 16); 605 cur = delim + 1; 606 np->remote_mac[5] = simple_strtol(cur, NULL, 16); 607 } 608 609 printk(KERN_INFO "%s: remote ethernet address " 610 "%02x:%02x:%02x:%02x:%02x:%02x\n", 611 np->name, 612 np->remote_mac[0], 613 np->remote_mac[1], 614 np->remote_mac[2], 615 np->remote_mac[3], 616 np->remote_mac[4], 617 np->remote_mac[5]); 618 619 return 0; 620 621 parse_failed: 622 printk(KERN_INFO "%s: couldn't parse config at %s!\n", 623 np->name, cur); 624 return -1; 625 } 626 627 int netpoll_setup(struct netpoll *np) 628 { 629 struct net_device *ndev = NULL; 630 struct in_device *in_dev; 631 struct netpoll_info *npinfo; 632 unsigned long flags; 633 int err; 634 635 if (np->dev_name) 636 ndev = dev_get_by_name(np->dev_name); 637 if (!ndev) { 638 printk(KERN_ERR "%s: %s doesn't exist, aborting.\n", 639 np->name, np->dev_name); 640 return -ENODEV; 641 } 642 643 np->dev = ndev; 644 if (!ndev->npinfo) { 645 npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL); 646 if (!npinfo) { 647 err = -ENOMEM; 648 goto release; 649 } 650 651 npinfo->rx_flags = 0; 652 npinfo->rx_np = NULL; 653 spin_lock_init(&npinfo->poll_lock); 654 npinfo->poll_owner = -1; 655 656 spin_lock_init(&npinfo->rx_lock); 657 skb_queue_head_init(&npinfo->arp_tx); 658 skb_queue_head_init(&npinfo->txq); 659 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process); 660 661 atomic_set(&npinfo->refcnt, 1); 662 } else { 663 npinfo = ndev->npinfo; 664 atomic_inc(&npinfo->refcnt); 665 } 666 667 if (!ndev->poll_controller) { 668 printk(KERN_ERR "%s: %s doesn't support polling, aborting.\n", 669 np->name, np->dev_name); 670 err = -ENOTSUPP; 671 goto release; 672 } 673 674 if (!netif_running(ndev)) { 675 unsigned long atmost, atleast; 676 677 printk(KERN_INFO "%s: device %s not up yet, forcing it\n", 678 np->name, np->dev_name); 679 680 rtnl_lock(); 681 err = dev_open(ndev); 682 rtnl_unlock(); 683 684 if (err) { 685 printk(KERN_ERR "%s: failed to open %s\n", 686 np->name, ndev->name); 687 goto release; 688 } 689 690 atleast = jiffies + HZ/10; 691 atmost = jiffies + 4*HZ; 692 while (!netif_carrier_ok(ndev)) { 693 if (time_after(jiffies, atmost)) { 694 printk(KERN_NOTICE 695 "%s: timeout waiting for carrier\n", 696 np->name); 697 break; 698 } 699 cond_resched(); 700 } 701 702 /* If carrier appears to come up instantly, we don't 703 * trust it and pause so that we don't pump all our 704 * queued console messages into the bitbucket. 705 */ 706 707 if (time_before(jiffies, atleast)) { 708 printk(KERN_NOTICE "%s: carrier detect appears" 709 " untrustworthy, waiting 4 seconds\n", 710 np->name); 711 msleep(4000); 712 } 713 } 714 715 if (is_zero_ether_addr(np->local_mac) && ndev->dev_addr) 716 memcpy(np->local_mac, ndev->dev_addr, 6); 717 718 if (!np->local_ip) { 719 rcu_read_lock(); 720 in_dev = __in_dev_get_rcu(ndev); 721 722 if (!in_dev || !in_dev->ifa_list) { 723 rcu_read_unlock(); 724 printk(KERN_ERR "%s: no IP address for %s, aborting\n", 725 np->name, np->dev_name); 726 err = -EDESTADDRREQ; 727 goto release; 728 } 729 730 np->local_ip = ntohl(in_dev->ifa_list->ifa_local); 731 rcu_read_unlock(); 732 printk(KERN_INFO "%s: local IP %d.%d.%d.%d\n", 733 np->name, HIPQUAD(np->local_ip)); 734 } 735 736 if (np->rx_hook) { 737 spin_lock_irqsave(&npinfo->rx_lock, flags); 738 npinfo->rx_flags |= NETPOLL_RX_ENABLED; 739 npinfo->rx_np = np; 740 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 741 } 742 743 /* fill up the skb queue */ 744 refill_skbs(); 745 746 /* last thing to do is link it to the net device structure */ 747 ndev->npinfo = npinfo; 748 749 /* avoid racing with NAPI reading npinfo */ 750 synchronize_rcu(); 751 752 return 0; 753 754 release: 755 if (!ndev->npinfo) 756 kfree(npinfo); 757 np->dev = NULL; 758 dev_put(ndev); 759 return err; 760 } 761 762 static int __init netpoll_init(void) 763 { 764 skb_queue_head_init(&skb_pool); 765 return 0; 766 } 767 core_initcall(netpoll_init); 768 769 void netpoll_cleanup(struct netpoll *np) 770 { 771 struct netpoll_info *npinfo; 772 unsigned long flags; 773 774 if (np->dev) { 775 npinfo = np->dev->npinfo; 776 if (npinfo) { 777 if (npinfo->rx_np == np) { 778 spin_lock_irqsave(&npinfo->rx_lock, flags); 779 npinfo->rx_np = NULL; 780 npinfo->rx_flags &= ~NETPOLL_RX_ENABLED; 781 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 782 } 783 784 np->dev->npinfo = NULL; 785 if (atomic_dec_and_test(&npinfo->refcnt)) { 786 skb_queue_purge(&npinfo->arp_tx); 787 skb_queue_purge(&npinfo->txq); 788 cancel_rearming_delayed_work(&npinfo->tx_work); 789 flush_scheduled_work(); 790 791 kfree(npinfo); 792 } 793 } 794 795 dev_put(np->dev); 796 } 797 798 np->dev = NULL; 799 } 800 801 int netpoll_trap(void) 802 { 803 return atomic_read(&trapped); 804 } 805 806 void netpoll_set_trap(int trap) 807 { 808 if (trap) 809 atomic_inc(&trapped); 810 else 811 atomic_dec(&trapped); 812 } 813 814 EXPORT_SYMBOL(netpoll_set_trap); 815 EXPORT_SYMBOL(netpoll_trap); 816 EXPORT_SYMBOL(netpoll_parse_options); 817 EXPORT_SYMBOL(netpoll_setup); 818 EXPORT_SYMBOL(netpoll_cleanup); 819 EXPORT_SYMBOL(netpoll_send_udp); 820 EXPORT_SYMBOL(netpoll_poll); 821