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 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 netif_tx_lock_bh(dev); 68 if (netif_queue_stopped(dev) || 69 dev->hard_start_xmit(skb, dev) != NETDEV_TX_OK) { 70 skb_queue_head(&npinfo->txq, skb); 71 netif_tx_unlock_bh(dev); 72 73 schedule_delayed_work(&npinfo->tx_work, HZ/10); 74 return; 75 } 76 } 77 } 78 79 static __sum16 checksum_udp(struct sk_buff *skb, struct udphdr *uh, 80 unsigned short ulen, __be32 saddr, __be32 daddr) 81 { 82 __wsum psum; 83 84 if (uh->check == 0 || skb->ip_summed == CHECKSUM_UNNECESSARY) 85 return 0; 86 87 psum = csum_tcpudp_nofold(saddr, daddr, ulen, IPPROTO_UDP, 0); 88 89 if (skb->ip_summed == CHECKSUM_COMPLETE && 90 !csum_fold(csum_add(psum, skb->csum))) 91 return 0; 92 93 skb->csum = psum; 94 95 return __skb_checksum_complete(skb); 96 } 97 98 /* 99 * Check whether delayed processing was scheduled for our NIC. If so, 100 * we attempt to grab the poll lock and use ->poll() to pump the card. 101 * If this fails, either we've recursed in ->poll() or it's already 102 * running on another CPU. 103 * 104 * Note: we don't mask interrupts with this lock because we're using 105 * trylock here and interrupts are already disabled in the softirq 106 * case. Further, we test the poll_owner to avoid recursion on UP 107 * systems where the lock doesn't exist. 108 * 109 * In cases where there is bi-directional communications, reading only 110 * one message at a time can lead to packets being dropped by the 111 * network adapter, forcing superfluous retries and possibly timeouts. 112 * Thus, we set our budget to greater than 1. 113 */ 114 static void poll_napi(struct netpoll *np) 115 { 116 struct netpoll_info *npinfo = np->dev->npinfo; 117 int budget = 16; 118 119 if (test_bit(__LINK_STATE_RX_SCHED, &np->dev->state) && 120 npinfo->poll_owner != smp_processor_id() && 121 spin_trylock(&npinfo->poll_lock)) { 122 npinfo->rx_flags |= NETPOLL_RX_DROP; 123 atomic_inc(&trapped); 124 125 np->dev->poll(np->dev, &budget); 126 127 atomic_dec(&trapped); 128 npinfo->rx_flags &= ~NETPOLL_RX_DROP; 129 spin_unlock(&npinfo->poll_lock); 130 } 131 } 132 133 static void service_arp_queue(struct netpoll_info *npi) 134 { 135 struct sk_buff *skb; 136 137 if (unlikely(!npi)) 138 return; 139 140 skb = skb_dequeue(&npi->arp_tx); 141 142 while (skb != NULL) { 143 arp_reply(skb); 144 skb = skb_dequeue(&npi->arp_tx); 145 } 146 } 147 148 void netpoll_poll(struct netpoll *np) 149 { 150 if (!np->dev || !netif_running(np->dev) || !np->dev->poll_controller) 151 return; 152 153 /* Process pending work on NIC */ 154 np->dev->poll_controller(np->dev); 155 if (np->dev->poll) 156 poll_napi(np); 157 158 service_arp_queue(np->dev->npinfo); 159 160 zap_completion_queue(); 161 } 162 163 static void refill_skbs(void) 164 { 165 struct sk_buff *skb; 166 unsigned long flags; 167 168 spin_lock_irqsave(&skb_pool.lock, flags); 169 while (skb_pool.qlen < MAX_SKBS) { 170 skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC); 171 if (!skb) 172 break; 173 174 __skb_queue_tail(&skb_pool, skb); 175 } 176 spin_unlock_irqrestore(&skb_pool.lock, flags); 177 } 178 179 static void zap_completion_queue(void) 180 { 181 unsigned long flags; 182 struct softnet_data *sd = &get_cpu_var(softnet_data); 183 184 if (sd->completion_queue) { 185 struct sk_buff *clist; 186 187 local_irq_save(flags); 188 clist = sd->completion_queue; 189 sd->completion_queue = NULL; 190 local_irq_restore(flags); 191 192 while (clist != NULL) { 193 struct sk_buff *skb = clist; 194 clist = clist->next; 195 if (skb->destructor) 196 dev_kfree_skb_any(skb); /* put this one back */ 197 else 198 __kfree_skb(skb); 199 } 200 } 201 202 put_cpu_var(softnet_data); 203 } 204 205 static struct sk_buff *find_skb(struct netpoll *np, int len, int reserve) 206 { 207 int count = 0; 208 struct sk_buff *skb; 209 210 zap_completion_queue(); 211 refill_skbs(); 212 repeat: 213 214 skb = alloc_skb(len, GFP_ATOMIC); 215 if (!skb) 216 skb = skb_dequeue(&skb_pool); 217 218 if (!skb) { 219 if (++count < 10) { 220 netpoll_poll(np); 221 goto repeat; 222 } 223 return NULL; 224 } 225 226 atomic_set(&skb->users, 1); 227 skb_reserve(skb, reserve); 228 return skb; 229 } 230 231 static void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb) 232 { 233 int status = NETDEV_TX_BUSY; 234 unsigned long tries; 235 struct net_device *dev = np->dev; 236 struct netpoll_info *npinfo = np->dev->npinfo; 237 238 if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) { 239 __kfree_skb(skb); 240 return; 241 } 242 243 /* don't get messages out of order, and no recursion */ 244 if (skb_queue_len(&npinfo->txq) == 0 && 245 npinfo->poll_owner != smp_processor_id() && 246 netif_tx_trylock(dev)) { 247 /* try until next clock tick */ 248 for (tries = jiffies_to_usecs(1)/USEC_PER_POLL; tries > 0; --tries) { 249 if (!netif_queue_stopped(dev)) 250 status = dev->hard_start_xmit(skb, dev); 251 252 if (status == NETDEV_TX_OK) 253 break; 254 255 /* tickle device maybe there is some cleanup */ 256 netpoll_poll(np); 257 258 udelay(USEC_PER_POLL); 259 } 260 netif_tx_unlock(dev); 261 } 262 263 if (status != NETDEV_TX_OK) { 264 skb_queue_tail(&npinfo->txq, skb); 265 schedule_delayed_work(&npinfo->tx_work,0); 266 } 267 } 268 269 void netpoll_send_udp(struct netpoll *np, const char *msg, int len) 270 { 271 int total_len, eth_len, ip_len, udp_len; 272 struct sk_buff *skb; 273 struct udphdr *udph; 274 struct iphdr *iph; 275 struct ethhdr *eth; 276 277 udp_len = len + sizeof(*udph); 278 ip_len = eth_len = udp_len + sizeof(*iph); 279 total_len = eth_len + ETH_HLEN + NET_IP_ALIGN; 280 281 skb = find_skb(np, total_len, total_len - len); 282 if (!skb) 283 return; 284 285 memcpy(skb->data, msg, len); 286 skb->len += len; 287 288 skb->h.uh = udph = (struct udphdr *) skb_push(skb, sizeof(*udph)); 289 udph->source = htons(np->local_port); 290 udph->dest = htons(np->remote_port); 291 udph->len = htons(udp_len); 292 udph->check = 0; 293 udph->check = csum_tcpudp_magic(htonl(np->local_ip), 294 htonl(np->remote_ip), 295 udp_len, IPPROTO_UDP, 296 csum_partial((unsigned char *)udph, udp_len, 0)); 297 if (udph->check == 0) 298 udph->check = CSUM_MANGLED_0; 299 300 skb->nh.iph = iph = (struct iphdr *)skb_push(skb, sizeof(*iph)); 301 302 /* iph->version = 4; iph->ihl = 5; */ 303 put_unaligned(0x45, (unsigned char *)iph); 304 iph->tos = 0; 305 put_unaligned(htons(ip_len), &(iph->tot_len)); 306 iph->id = 0; 307 iph->frag_off = 0; 308 iph->ttl = 64; 309 iph->protocol = IPPROTO_UDP; 310 iph->check = 0; 311 put_unaligned(htonl(np->local_ip), &(iph->saddr)); 312 put_unaligned(htonl(np->remote_ip), &(iph->daddr)); 313 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); 314 315 eth = (struct ethhdr *) skb_push(skb, ETH_HLEN); 316 skb->mac.raw = skb->data; 317 skb->protocol = eth->h_proto = htons(ETH_P_IP); 318 memcpy(eth->h_source, np->local_mac, 6); 319 memcpy(eth->h_dest, np->remote_mac, 6); 320 321 skb->dev = np->dev; 322 323 netpoll_send_skb(np, skb); 324 } 325 326 static void arp_reply(struct sk_buff *skb) 327 { 328 struct netpoll_info *npinfo = skb->dev->npinfo; 329 struct arphdr *arp; 330 unsigned char *arp_ptr; 331 int size, type = ARPOP_REPLY, ptype = ETH_P_ARP; 332 __be32 sip, tip; 333 struct sk_buff *send_skb; 334 struct netpoll *np = NULL; 335 336 if (npinfo->rx_np && npinfo->rx_np->dev == skb->dev) 337 np = npinfo->rx_np; 338 if (!np) 339 return; 340 341 /* No arp on this interface */ 342 if (skb->dev->flags & IFF_NOARP) 343 return; 344 345 if (!pskb_may_pull(skb, (sizeof(struct arphdr) + 346 (2 * skb->dev->addr_len) + 347 (2 * sizeof(u32))))) 348 return; 349 350 skb->h.raw = skb->nh.raw = skb->data; 351 arp = skb->nh.arph; 352 353 if ((arp->ar_hrd != htons(ARPHRD_ETHER) && 354 arp->ar_hrd != htons(ARPHRD_IEEE802)) || 355 arp->ar_pro != htons(ETH_P_IP) || 356 arp->ar_op != htons(ARPOP_REQUEST)) 357 return; 358 359 arp_ptr = (unsigned char *)(arp+1) + skb->dev->addr_len; 360 memcpy(&sip, arp_ptr, 4); 361 arp_ptr += 4 + skb->dev->addr_len; 362 memcpy(&tip, arp_ptr, 4); 363 364 /* Should we ignore arp? */ 365 if (tip != htonl(np->local_ip) || LOOPBACK(tip) || MULTICAST(tip)) 366 return; 367 368 size = sizeof(struct arphdr) + 2 * (skb->dev->addr_len + 4); 369 send_skb = find_skb(np, size + LL_RESERVED_SPACE(np->dev), 370 LL_RESERVED_SPACE(np->dev)); 371 372 if (!send_skb) 373 return; 374 375 send_skb->nh.raw = send_skb->data; 376 arp = (struct arphdr *) skb_put(send_skb, size); 377 send_skb->dev = skb->dev; 378 send_skb->protocol = htons(ETH_P_ARP); 379 380 /* Fill the device header for the ARP frame */ 381 382 if (np->dev->hard_header && 383 np->dev->hard_header(send_skb, skb->dev, ptype, 384 np->remote_mac, np->local_mac, 385 send_skb->len) < 0) { 386 kfree_skb(send_skb); 387 return; 388 } 389 390 /* 391 * Fill out the arp protocol part. 392 * 393 * we only support ethernet device type, 394 * which (according to RFC 1390) should always equal 1 (Ethernet). 395 */ 396 397 arp->ar_hrd = htons(np->dev->type); 398 arp->ar_pro = htons(ETH_P_IP); 399 arp->ar_hln = np->dev->addr_len; 400 arp->ar_pln = 4; 401 arp->ar_op = htons(type); 402 403 arp_ptr=(unsigned char *)(arp + 1); 404 memcpy(arp_ptr, np->dev->dev_addr, np->dev->addr_len); 405 arp_ptr += np->dev->addr_len; 406 memcpy(arp_ptr, &tip, 4); 407 arp_ptr += 4; 408 memcpy(arp_ptr, np->remote_mac, np->dev->addr_len); 409 arp_ptr += np->dev->addr_len; 410 memcpy(arp_ptr, &sip, 4); 411 412 netpoll_send_skb(np, send_skb); 413 } 414 415 int __netpoll_rx(struct sk_buff *skb) 416 { 417 int proto, len, ulen; 418 struct iphdr *iph; 419 struct udphdr *uh; 420 struct netpoll_info *npi = skb->dev->npinfo; 421 struct netpoll *np = npi->rx_np; 422 423 if (!np) 424 goto out; 425 if (skb->dev->type != ARPHRD_ETHER) 426 goto out; 427 428 /* check if netpoll clients need ARP */ 429 if (skb->protocol == __constant_htons(ETH_P_ARP) && 430 atomic_read(&trapped)) { 431 skb_queue_tail(&npi->arp_tx, skb); 432 return 1; 433 } 434 435 proto = ntohs(eth_hdr(skb)->h_proto); 436 if (proto != ETH_P_IP) 437 goto out; 438 if (skb->pkt_type == PACKET_OTHERHOST) 439 goto out; 440 if (skb_shared(skb)) 441 goto out; 442 443 iph = (struct iphdr *)skb->data; 444 if (!pskb_may_pull(skb, sizeof(struct iphdr))) 445 goto out; 446 if (iph->ihl < 5 || iph->version != 4) 447 goto out; 448 if (!pskb_may_pull(skb, iph->ihl*4)) 449 goto out; 450 if (ip_fast_csum((u8 *)iph, iph->ihl) != 0) 451 goto out; 452 453 len = ntohs(iph->tot_len); 454 if (skb->len < len || len < iph->ihl*4) 455 goto out; 456 457 if (iph->protocol != IPPROTO_UDP) 458 goto out; 459 460 len -= iph->ihl*4; 461 uh = (struct udphdr *)(((char *)iph) + iph->ihl*4); 462 ulen = ntohs(uh->len); 463 464 if (ulen != len) 465 goto out; 466 if (checksum_udp(skb, uh, ulen, iph->saddr, iph->daddr)) 467 goto out; 468 if (np->local_ip && np->local_ip != ntohl(iph->daddr)) 469 goto out; 470 if (np->remote_ip && np->remote_ip != ntohl(iph->saddr)) 471 goto out; 472 if (np->local_port && np->local_port != ntohs(uh->dest)) 473 goto out; 474 475 np->rx_hook(np, ntohs(uh->source), 476 (char *)(uh+1), 477 ulen - sizeof(struct udphdr)); 478 479 kfree_skb(skb); 480 return 1; 481 482 out: 483 if (atomic_read(&trapped)) { 484 kfree_skb(skb); 485 return 1; 486 } 487 488 return 0; 489 } 490 491 int netpoll_parse_options(struct netpoll *np, char *opt) 492 { 493 char *cur=opt, *delim; 494 495 if (*cur != '@') { 496 if ((delim = strchr(cur, '@')) == NULL) 497 goto parse_failed; 498 *delim = 0; 499 np->local_port = simple_strtol(cur, NULL, 10); 500 cur = delim; 501 } 502 cur++; 503 printk(KERN_INFO "%s: local port %d\n", np->name, np->local_port); 504 505 if (*cur != '/') { 506 if ((delim = strchr(cur, '/')) == NULL) 507 goto parse_failed; 508 *delim = 0; 509 np->local_ip = ntohl(in_aton(cur)); 510 cur = delim; 511 512 printk(KERN_INFO "%s: local IP %d.%d.%d.%d\n", 513 np->name, HIPQUAD(np->local_ip)); 514 } 515 cur++; 516 517 if (*cur != ',') { 518 /* parse out dev name */ 519 if ((delim = strchr(cur, ',')) == NULL) 520 goto parse_failed; 521 *delim = 0; 522 strlcpy(np->dev_name, cur, sizeof(np->dev_name)); 523 cur = delim; 524 } 525 cur++; 526 527 printk(KERN_INFO "%s: interface %s\n", np->name, np->dev_name); 528 529 if (*cur != '@') { 530 /* dst port */ 531 if ((delim = strchr(cur, '@')) == NULL) 532 goto parse_failed; 533 *delim = 0; 534 np->remote_port = simple_strtol(cur, NULL, 10); 535 cur = delim; 536 } 537 cur++; 538 printk(KERN_INFO "%s: remote port %d\n", np->name, np->remote_port); 539 540 /* dst ip */ 541 if ((delim = strchr(cur, '/')) == NULL) 542 goto parse_failed; 543 *delim = 0; 544 np->remote_ip = ntohl(in_aton(cur)); 545 cur = delim + 1; 546 547 printk(KERN_INFO "%s: remote IP %d.%d.%d.%d\n", 548 np->name, HIPQUAD(np->remote_ip)); 549 550 if (*cur != 0) { 551 /* MAC address */ 552 if ((delim = strchr(cur, ':')) == NULL) 553 goto parse_failed; 554 *delim = 0; 555 np->remote_mac[0] = simple_strtol(cur, NULL, 16); 556 cur = delim + 1; 557 if ((delim = strchr(cur, ':')) == NULL) 558 goto parse_failed; 559 *delim = 0; 560 np->remote_mac[1] = simple_strtol(cur, NULL, 16); 561 cur = delim + 1; 562 if ((delim = strchr(cur, ':')) == NULL) 563 goto parse_failed; 564 *delim = 0; 565 np->remote_mac[2] = simple_strtol(cur, NULL, 16); 566 cur = delim + 1; 567 if ((delim = strchr(cur, ':')) == NULL) 568 goto parse_failed; 569 *delim = 0; 570 np->remote_mac[3] = simple_strtol(cur, NULL, 16); 571 cur = delim + 1; 572 if ((delim = strchr(cur, ':')) == NULL) 573 goto parse_failed; 574 *delim = 0; 575 np->remote_mac[4] = simple_strtol(cur, NULL, 16); 576 cur = delim + 1; 577 np->remote_mac[5] = simple_strtol(cur, NULL, 16); 578 } 579 580 printk(KERN_INFO "%s: remote ethernet address " 581 "%02x:%02x:%02x:%02x:%02x:%02x\n", 582 np->name, 583 np->remote_mac[0], 584 np->remote_mac[1], 585 np->remote_mac[2], 586 np->remote_mac[3], 587 np->remote_mac[4], 588 np->remote_mac[5]); 589 590 return 0; 591 592 parse_failed: 593 printk(KERN_INFO "%s: couldn't parse config at %s!\n", 594 np->name, cur); 595 return -1; 596 } 597 598 int netpoll_setup(struct netpoll *np) 599 { 600 struct net_device *ndev = NULL; 601 struct in_device *in_dev; 602 struct netpoll_info *npinfo; 603 unsigned long flags; 604 int err; 605 606 if (np->dev_name) 607 ndev = dev_get_by_name(np->dev_name); 608 if (!ndev) { 609 printk(KERN_ERR "%s: %s doesn't exist, aborting.\n", 610 np->name, np->dev_name); 611 return -ENODEV; 612 } 613 614 np->dev = ndev; 615 if (!ndev->npinfo) { 616 npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL); 617 if (!npinfo) { 618 err = -ENOMEM; 619 goto release; 620 } 621 622 npinfo->rx_flags = 0; 623 npinfo->rx_np = NULL; 624 spin_lock_init(&npinfo->poll_lock); 625 npinfo->poll_owner = -1; 626 627 spin_lock_init(&npinfo->rx_lock); 628 skb_queue_head_init(&npinfo->arp_tx); 629 skb_queue_head_init(&npinfo->txq); 630 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process); 631 632 atomic_set(&npinfo->refcnt, 1); 633 } else { 634 npinfo = ndev->npinfo; 635 atomic_inc(&npinfo->refcnt); 636 } 637 638 if (!ndev->poll_controller) { 639 printk(KERN_ERR "%s: %s doesn't support polling, aborting.\n", 640 np->name, np->dev_name); 641 err = -ENOTSUPP; 642 goto release; 643 } 644 645 if (!netif_running(ndev)) { 646 unsigned long atmost, atleast; 647 648 printk(KERN_INFO "%s: device %s not up yet, forcing it\n", 649 np->name, np->dev_name); 650 651 rtnl_lock(); 652 err = dev_open(ndev); 653 rtnl_unlock(); 654 655 if (err) { 656 printk(KERN_ERR "%s: failed to open %s\n", 657 np->name, ndev->name); 658 goto release; 659 } 660 661 atleast = jiffies + HZ/10; 662 atmost = jiffies + 4*HZ; 663 while (!netif_carrier_ok(ndev)) { 664 if (time_after(jiffies, atmost)) { 665 printk(KERN_NOTICE 666 "%s: timeout waiting for carrier\n", 667 np->name); 668 break; 669 } 670 cond_resched(); 671 } 672 673 /* If carrier appears to come up instantly, we don't 674 * trust it and pause so that we don't pump all our 675 * queued console messages into the bitbucket. 676 */ 677 678 if (time_before(jiffies, atleast)) { 679 printk(KERN_NOTICE "%s: carrier detect appears" 680 " untrustworthy, waiting 4 seconds\n", 681 np->name); 682 msleep(4000); 683 } 684 } 685 686 if (is_zero_ether_addr(np->local_mac) && ndev->dev_addr) 687 memcpy(np->local_mac, ndev->dev_addr, 6); 688 689 if (!np->local_ip) { 690 rcu_read_lock(); 691 in_dev = __in_dev_get_rcu(ndev); 692 693 if (!in_dev || !in_dev->ifa_list) { 694 rcu_read_unlock(); 695 printk(KERN_ERR "%s: no IP address for %s, aborting\n", 696 np->name, np->dev_name); 697 err = -EDESTADDRREQ; 698 goto release; 699 } 700 701 np->local_ip = ntohl(in_dev->ifa_list->ifa_local); 702 rcu_read_unlock(); 703 printk(KERN_INFO "%s: local IP %d.%d.%d.%d\n", 704 np->name, HIPQUAD(np->local_ip)); 705 } 706 707 if (np->rx_hook) { 708 spin_lock_irqsave(&npinfo->rx_lock, flags); 709 npinfo->rx_flags |= NETPOLL_RX_ENABLED; 710 npinfo->rx_np = np; 711 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 712 } 713 714 /* fill up the skb queue */ 715 refill_skbs(); 716 717 /* last thing to do is link it to the net device structure */ 718 ndev->npinfo = npinfo; 719 720 /* avoid racing with NAPI reading npinfo */ 721 synchronize_rcu(); 722 723 return 0; 724 725 release: 726 if (!ndev->npinfo) 727 kfree(npinfo); 728 np->dev = NULL; 729 dev_put(ndev); 730 return err; 731 } 732 733 static int __init netpoll_init(void) 734 { 735 skb_queue_head_init(&skb_pool); 736 return 0; 737 } 738 core_initcall(netpoll_init); 739 740 void netpoll_cleanup(struct netpoll *np) 741 { 742 struct netpoll_info *npinfo; 743 unsigned long flags; 744 745 if (np->dev) { 746 npinfo = np->dev->npinfo; 747 if (npinfo) { 748 if (npinfo->rx_np == np) { 749 spin_lock_irqsave(&npinfo->rx_lock, flags); 750 npinfo->rx_np = NULL; 751 npinfo->rx_flags &= ~NETPOLL_RX_ENABLED; 752 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 753 } 754 755 np->dev->npinfo = NULL; 756 if (atomic_dec_and_test(&npinfo->refcnt)) { 757 skb_queue_purge(&npinfo->arp_tx); 758 skb_queue_purge(&npinfo->txq); 759 cancel_rearming_delayed_work(&npinfo->tx_work); 760 flush_scheduled_work(); 761 762 kfree(npinfo); 763 } 764 } 765 766 dev_put(np->dev); 767 } 768 769 np->dev = NULL; 770 } 771 772 int netpoll_trap(void) 773 { 774 return atomic_read(&trapped); 775 } 776 777 void netpoll_set_trap(int trap) 778 { 779 if (trap) 780 atomic_inc(&trapped); 781 else 782 atomic_dec(&trapped); 783 } 784 785 EXPORT_SYMBOL(netpoll_set_trap); 786 EXPORT_SYMBOL(netpoll_trap); 787 EXPORT_SYMBOL(netpoll_parse_options); 788 EXPORT_SYMBOL(netpoll_setup); 789 EXPORT_SYMBOL(netpoll_cleanup); 790 EXPORT_SYMBOL(netpoll_send_udp); 791 EXPORT_SYMBOL(netpoll_poll); 792