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/moduleparam.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 <linux/slab.h> 26 #include <net/tcp.h> 27 #include <net/udp.h> 28 #include <asm/unaligned.h> 29 #include <trace/events/napi.h> 30 31 /* 32 * We maintain a small pool of fully-sized skbs, to make sure the 33 * message gets out even in extreme OOM situations. 34 */ 35 36 #define MAX_UDP_CHUNK 1460 37 #define MAX_SKBS 32 38 39 static struct sk_buff_head skb_pool; 40 41 static atomic_t trapped; 42 43 #define USEC_PER_POLL 50 44 #define NETPOLL_RX_ENABLED 1 45 #define NETPOLL_RX_DROP 2 46 47 #define MAX_SKB_SIZE \ 48 (MAX_UDP_CHUNK + sizeof(struct udphdr) + \ 49 sizeof(struct iphdr) + sizeof(struct ethhdr)) 50 51 static void zap_completion_queue(void); 52 static void arp_reply(struct sk_buff *skb); 53 54 static unsigned int carrier_timeout = 4; 55 module_param(carrier_timeout, uint, 0644); 56 57 static void queue_process(struct work_struct *work) 58 { 59 struct netpoll_info *npinfo = 60 container_of(work, struct netpoll_info, tx_work.work); 61 struct sk_buff *skb; 62 unsigned long flags; 63 64 while ((skb = skb_dequeue(&npinfo->txq))) { 65 struct net_device *dev = skb->dev; 66 const struct net_device_ops *ops = dev->netdev_ops; 67 struct netdev_queue *txq; 68 69 if (!netif_device_present(dev) || !netif_running(dev)) { 70 __kfree_skb(skb); 71 continue; 72 } 73 74 txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb)); 75 76 local_irq_save(flags); 77 __netif_tx_lock(txq, smp_processor_id()); 78 if (netif_tx_queue_frozen_or_stopped(txq) || 79 ops->ndo_start_xmit(skb, dev) != NETDEV_TX_OK) { 80 skb_queue_head(&npinfo->txq, skb); 81 __netif_tx_unlock(txq); 82 local_irq_restore(flags); 83 84 schedule_delayed_work(&npinfo->tx_work, HZ/10); 85 return; 86 } 87 __netif_tx_unlock(txq); 88 local_irq_restore(flags); 89 } 90 } 91 92 static __sum16 checksum_udp(struct sk_buff *skb, struct udphdr *uh, 93 unsigned short ulen, __be32 saddr, __be32 daddr) 94 { 95 __wsum psum; 96 97 if (uh->check == 0 || skb_csum_unnecessary(skb)) 98 return 0; 99 100 psum = csum_tcpudp_nofold(saddr, daddr, ulen, IPPROTO_UDP, 0); 101 102 if (skb->ip_summed == CHECKSUM_COMPLETE && 103 !csum_fold(csum_add(psum, skb->csum))) 104 return 0; 105 106 skb->csum = psum; 107 108 return __skb_checksum_complete(skb); 109 } 110 111 /* 112 * Check whether delayed processing was scheduled for our NIC. If so, 113 * we attempt to grab the poll lock and use ->poll() to pump the card. 114 * If this fails, either we've recursed in ->poll() or it's already 115 * running on another CPU. 116 * 117 * Note: we don't mask interrupts with this lock because we're using 118 * trylock here and interrupts are already disabled in the softirq 119 * case. Further, we test the poll_owner to avoid recursion on UP 120 * systems where the lock doesn't exist. 121 * 122 * In cases where there is bi-directional communications, reading only 123 * one message at a time can lead to packets being dropped by the 124 * network adapter, forcing superfluous retries and possibly timeouts. 125 * Thus, we set our budget to greater than 1. 126 */ 127 static int poll_one_napi(struct netpoll_info *npinfo, 128 struct napi_struct *napi, int budget) 129 { 130 int work; 131 132 /* net_rx_action's ->poll() invocations and our's are 133 * synchronized by this test which is only made while 134 * holding the napi->poll_lock. 135 */ 136 if (!test_bit(NAPI_STATE_SCHED, &napi->state)) 137 return budget; 138 139 npinfo->rx_flags |= NETPOLL_RX_DROP; 140 atomic_inc(&trapped); 141 set_bit(NAPI_STATE_NPSVC, &napi->state); 142 143 work = napi->poll(napi, budget); 144 trace_napi_poll(napi); 145 146 clear_bit(NAPI_STATE_NPSVC, &napi->state); 147 atomic_dec(&trapped); 148 npinfo->rx_flags &= ~NETPOLL_RX_DROP; 149 150 return budget - work; 151 } 152 153 static void poll_napi(struct net_device *dev) 154 { 155 struct napi_struct *napi; 156 int budget = 16; 157 158 list_for_each_entry(napi, &dev->napi_list, dev_list) { 159 if (napi->poll_owner != smp_processor_id() && 160 spin_trylock(&napi->poll_lock)) { 161 budget = poll_one_napi(dev->npinfo, napi, budget); 162 spin_unlock(&napi->poll_lock); 163 164 if (!budget) 165 break; 166 } 167 } 168 } 169 170 static void service_arp_queue(struct netpoll_info *npi) 171 { 172 if (npi) { 173 struct sk_buff *skb; 174 175 while ((skb = skb_dequeue(&npi->arp_tx))) 176 arp_reply(skb); 177 } 178 } 179 180 void netpoll_poll_dev(struct net_device *dev) 181 { 182 const struct net_device_ops *ops; 183 184 if (!dev || !netif_running(dev)) 185 return; 186 187 ops = dev->netdev_ops; 188 if (!ops->ndo_poll_controller) 189 return; 190 191 /* Process pending work on NIC */ 192 ops->ndo_poll_controller(dev); 193 194 poll_napi(dev); 195 196 service_arp_queue(dev->npinfo); 197 198 zap_completion_queue(); 199 } 200 EXPORT_SYMBOL(netpoll_poll_dev); 201 202 void netpoll_poll(struct netpoll *np) 203 { 204 netpoll_poll_dev(np->dev); 205 } 206 EXPORT_SYMBOL(netpoll_poll); 207 208 static void refill_skbs(void) 209 { 210 struct sk_buff *skb; 211 unsigned long flags; 212 213 spin_lock_irqsave(&skb_pool.lock, flags); 214 while (skb_pool.qlen < MAX_SKBS) { 215 skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC); 216 if (!skb) 217 break; 218 219 __skb_queue_tail(&skb_pool, skb); 220 } 221 spin_unlock_irqrestore(&skb_pool.lock, flags); 222 } 223 224 static void zap_completion_queue(void) 225 { 226 unsigned long flags; 227 struct softnet_data *sd = &get_cpu_var(softnet_data); 228 229 if (sd->completion_queue) { 230 struct sk_buff *clist; 231 232 local_irq_save(flags); 233 clist = sd->completion_queue; 234 sd->completion_queue = NULL; 235 local_irq_restore(flags); 236 237 while (clist != NULL) { 238 struct sk_buff *skb = clist; 239 clist = clist->next; 240 if (skb->destructor) { 241 atomic_inc(&skb->users); 242 dev_kfree_skb_any(skb); /* put this one back */ 243 } else { 244 __kfree_skb(skb); 245 } 246 } 247 } 248 249 put_cpu_var(softnet_data); 250 } 251 252 static struct sk_buff *find_skb(struct netpoll *np, int len, int reserve) 253 { 254 int count = 0; 255 struct sk_buff *skb; 256 257 zap_completion_queue(); 258 refill_skbs(); 259 repeat: 260 261 skb = alloc_skb(len, GFP_ATOMIC); 262 if (!skb) 263 skb = skb_dequeue(&skb_pool); 264 265 if (!skb) { 266 if (++count < 10) { 267 netpoll_poll(np); 268 goto repeat; 269 } 270 return NULL; 271 } 272 273 atomic_set(&skb->users, 1); 274 skb_reserve(skb, reserve); 275 return skb; 276 } 277 278 static int netpoll_owner_active(struct net_device *dev) 279 { 280 struct napi_struct *napi; 281 282 list_for_each_entry(napi, &dev->napi_list, dev_list) { 283 if (napi->poll_owner == smp_processor_id()) 284 return 1; 285 } 286 return 0; 287 } 288 289 void netpoll_send_skb_on_dev(struct netpoll *np, struct sk_buff *skb, 290 struct net_device *dev) 291 { 292 int status = NETDEV_TX_BUSY; 293 unsigned long tries; 294 const struct net_device_ops *ops = dev->netdev_ops; 295 /* It is up to the caller to keep npinfo alive. */ 296 struct netpoll_info *npinfo = np->dev->npinfo; 297 298 if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) { 299 __kfree_skb(skb); 300 return; 301 } 302 303 /* don't get messages out of order, and no recursion */ 304 if (skb_queue_len(&npinfo->txq) == 0 && !netpoll_owner_active(dev)) { 305 struct netdev_queue *txq; 306 unsigned long flags; 307 308 txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb)); 309 310 local_irq_save(flags); 311 /* try until next clock tick */ 312 for (tries = jiffies_to_usecs(1)/USEC_PER_POLL; 313 tries > 0; --tries) { 314 if (__netif_tx_trylock(txq)) { 315 if (!netif_tx_queue_stopped(txq)) { 316 dev->priv_flags |= IFF_IN_NETPOLL; 317 status = ops->ndo_start_xmit(skb, dev); 318 dev->priv_flags &= ~IFF_IN_NETPOLL; 319 if (status == NETDEV_TX_OK) 320 txq_trans_update(txq); 321 } 322 __netif_tx_unlock(txq); 323 324 if (status == NETDEV_TX_OK) 325 break; 326 327 } 328 329 /* tickle device maybe there is some cleanup */ 330 netpoll_poll(np); 331 332 udelay(USEC_PER_POLL); 333 } 334 335 WARN_ONCE(!irqs_disabled(), 336 "netpoll_send_skb(): %s enabled interrupts in poll (%pF)\n", 337 dev->name, ops->ndo_start_xmit); 338 339 local_irq_restore(flags); 340 } 341 342 if (status != NETDEV_TX_OK) { 343 skb_queue_tail(&npinfo->txq, skb); 344 schedule_delayed_work(&npinfo->tx_work,0); 345 } 346 } 347 EXPORT_SYMBOL(netpoll_send_skb_on_dev); 348 349 void netpoll_send_udp(struct netpoll *np, const char *msg, int len) 350 { 351 int total_len, eth_len, ip_len, udp_len; 352 struct sk_buff *skb; 353 struct udphdr *udph; 354 struct iphdr *iph; 355 struct ethhdr *eth; 356 357 udp_len = len + sizeof(*udph); 358 ip_len = eth_len = udp_len + sizeof(*iph); 359 total_len = eth_len + ETH_HLEN + NET_IP_ALIGN; 360 361 skb = find_skb(np, total_len, total_len - len); 362 if (!skb) 363 return; 364 365 skb_copy_to_linear_data(skb, msg, len); 366 skb->len += len; 367 368 skb_push(skb, sizeof(*udph)); 369 skb_reset_transport_header(skb); 370 udph = udp_hdr(skb); 371 udph->source = htons(np->local_port); 372 udph->dest = htons(np->remote_port); 373 udph->len = htons(udp_len); 374 udph->check = 0; 375 udph->check = csum_tcpudp_magic(np->local_ip, 376 np->remote_ip, 377 udp_len, IPPROTO_UDP, 378 csum_partial(udph, udp_len, 0)); 379 if (udph->check == 0) 380 udph->check = CSUM_MANGLED_0; 381 382 skb_push(skb, sizeof(*iph)); 383 skb_reset_network_header(skb); 384 iph = ip_hdr(skb); 385 386 /* iph->version = 4; iph->ihl = 5; */ 387 put_unaligned(0x45, (unsigned char *)iph); 388 iph->tos = 0; 389 put_unaligned(htons(ip_len), &(iph->tot_len)); 390 iph->id = 0; 391 iph->frag_off = 0; 392 iph->ttl = 64; 393 iph->protocol = IPPROTO_UDP; 394 iph->check = 0; 395 put_unaligned(np->local_ip, &(iph->saddr)); 396 put_unaligned(np->remote_ip, &(iph->daddr)); 397 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); 398 399 eth = (struct ethhdr *) skb_push(skb, ETH_HLEN); 400 skb_reset_mac_header(skb); 401 skb->protocol = eth->h_proto = htons(ETH_P_IP); 402 memcpy(eth->h_source, np->dev->dev_addr, ETH_ALEN); 403 memcpy(eth->h_dest, np->remote_mac, ETH_ALEN); 404 405 skb->dev = np->dev; 406 407 netpoll_send_skb(np, skb); 408 } 409 EXPORT_SYMBOL(netpoll_send_udp); 410 411 static void arp_reply(struct sk_buff *skb) 412 { 413 struct netpoll_info *npinfo = skb->dev->npinfo; 414 struct arphdr *arp; 415 unsigned char *arp_ptr; 416 int size, type = ARPOP_REPLY, ptype = ETH_P_ARP; 417 __be32 sip, tip; 418 unsigned char *sha; 419 struct sk_buff *send_skb; 420 struct netpoll *np, *tmp; 421 unsigned long flags; 422 int hits = 0; 423 424 if (list_empty(&npinfo->rx_np)) 425 return; 426 427 /* Before checking the packet, we do some early 428 inspection whether this is interesting at all */ 429 spin_lock_irqsave(&npinfo->rx_lock, flags); 430 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) { 431 if (np->dev == skb->dev) 432 hits++; 433 } 434 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 435 436 /* No netpoll struct is using this dev */ 437 if (!hits) 438 return; 439 440 /* No arp on this interface */ 441 if (skb->dev->flags & IFF_NOARP) 442 return; 443 444 if (!pskb_may_pull(skb, arp_hdr_len(skb->dev))) 445 return; 446 447 skb_reset_network_header(skb); 448 skb_reset_transport_header(skb); 449 arp = arp_hdr(skb); 450 451 if ((arp->ar_hrd != htons(ARPHRD_ETHER) && 452 arp->ar_hrd != htons(ARPHRD_IEEE802)) || 453 arp->ar_pro != htons(ETH_P_IP) || 454 arp->ar_op != htons(ARPOP_REQUEST)) 455 return; 456 457 arp_ptr = (unsigned char *)(arp+1); 458 /* save the location of the src hw addr */ 459 sha = arp_ptr; 460 arp_ptr += skb->dev->addr_len; 461 memcpy(&sip, arp_ptr, 4); 462 arp_ptr += 4; 463 /* If we actually cared about dst hw addr, 464 it would get copied here */ 465 arp_ptr += skb->dev->addr_len; 466 memcpy(&tip, arp_ptr, 4); 467 468 /* Should we ignore arp? */ 469 if (ipv4_is_loopback(tip) || ipv4_is_multicast(tip)) 470 return; 471 472 size = arp_hdr_len(skb->dev); 473 474 spin_lock_irqsave(&npinfo->rx_lock, flags); 475 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) { 476 if (tip != np->local_ip) 477 continue; 478 479 send_skb = find_skb(np, size + LL_ALLOCATED_SPACE(np->dev), 480 LL_RESERVED_SPACE(np->dev)); 481 if (!send_skb) 482 continue; 483 484 skb_reset_network_header(send_skb); 485 arp = (struct arphdr *) skb_put(send_skb, size); 486 send_skb->dev = skb->dev; 487 send_skb->protocol = htons(ETH_P_ARP); 488 489 /* Fill the device header for the ARP frame */ 490 if (dev_hard_header(send_skb, skb->dev, ptype, 491 sha, np->dev->dev_addr, 492 send_skb->len) < 0) { 493 kfree_skb(send_skb); 494 continue; 495 } 496 497 /* 498 * Fill out the arp protocol part. 499 * 500 * we only support ethernet device type, 501 * which (according to RFC 1390) should 502 * always equal 1 (Ethernet). 503 */ 504 505 arp->ar_hrd = htons(np->dev->type); 506 arp->ar_pro = htons(ETH_P_IP); 507 arp->ar_hln = np->dev->addr_len; 508 arp->ar_pln = 4; 509 arp->ar_op = htons(type); 510 511 arp_ptr = (unsigned char *)(arp + 1); 512 memcpy(arp_ptr, np->dev->dev_addr, np->dev->addr_len); 513 arp_ptr += np->dev->addr_len; 514 memcpy(arp_ptr, &tip, 4); 515 arp_ptr += 4; 516 memcpy(arp_ptr, sha, np->dev->addr_len); 517 arp_ptr += np->dev->addr_len; 518 memcpy(arp_ptr, &sip, 4); 519 520 netpoll_send_skb(np, send_skb); 521 522 /* If there are several rx_hooks for the same address, 523 we're fine by sending a single reply */ 524 break; 525 } 526 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 527 } 528 529 int __netpoll_rx(struct sk_buff *skb) 530 { 531 int proto, len, ulen; 532 int hits = 0; 533 struct iphdr *iph; 534 struct udphdr *uh; 535 struct netpoll_info *npinfo = skb->dev->npinfo; 536 struct netpoll *np, *tmp; 537 538 if (list_empty(&npinfo->rx_np)) 539 goto out; 540 541 if (skb->dev->type != ARPHRD_ETHER) 542 goto out; 543 544 /* check if netpoll clients need ARP */ 545 if (skb->protocol == htons(ETH_P_ARP) && 546 atomic_read(&trapped)) { 547 skb_queue_tail(&npinfo->arp_tx, skb); 548 return 1; 549 } 550 551 proto = ntohs(eth_hdr(skb)->h_proto); 552 if (proto != ETH_P_IP) 553 goto out; 554 if (skb->pkt_type == PACKET_OTHERHOST) 555 goto out; 556 if (skb_shared(skb)) 557 goto out; 558 559 iph = (struct iphdr *)skb->data; 560 if (!pskb_may_pull(skb, sizeof(struct iphdr))) 561 goto out; 562 if (iph->ihl < 5 || iph->version != 4) 563 goto out; 564 if (!pskb_may_pull(skb, iph->ihl*4)) 565 goto out; 566 if (ip_fast_csum((u8 *)iph, iph->ihl) != 0) 567 goto out; 568 569 len = ntohs(iph->tot_len); 570 if (skb->len < len || len < iph->ihl*4) 571 goto out; 572 573 /* 574 * Our transport medium may have padded the buffer out. 575 * Now We trim to the true length of the frame. 576 */ 577 if (pskb_trim_rcsum(skb, len)) 578 goto out; 579 580 if (iph->protocol != IPPROTO_UDP) 581 goto out; 582 583 len -= iph->ihl*4; 584 uh = (struct udphdr *)(((char *)iph) + iph->ihl*4); 585 ulen = ntohs(uh->len); 586 587 if (ulen != len) 588 goto out; 589 if (checksum_udp(skb, uh, ulen, iph->saddr, iph->daddr)) 590 goto out; 591 592 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) { 593 if (np->local_ip && np->local_ip != iph->daddr) 594 continue; 595 if (np->remote_ip && np->remote_ip != iph->saddr) 596 continue; 597 if (np->local_port && np->local_port != ntohs(uh->dest)) 598 continue; 599 600 np->rx_hook(np, ntohs(uh->source), 601 (char *)(uh+1), 602 ulen - sizeof(struct udphdr)); 603 hits++; 604 } 605 606 if (!hits) 607 goto out; 608 609 kfree_skb(skb); 610 return 1; 611 612 out: 613 if (atomic_read(&trapped)) { 614 kfree_skb(skb); 615 return 1; 616 } 617 618 return 0; 619 } 620 621 void netpoll_print_options(struct netpoll *np) 622 { 623 printk(KERN_INFO "%s: local port %d\n", 624 np->name, np->local_port); 625 printk(KERN_INFO "%s: local IP %pI4\n", 626 np->name, &np->local_ip); 627 printk(KERN_INFO "%s: interface '%s'\n", 628 np->name, np->dev_name); 629 printk(KERN_INFO "%s: remote port %d\n", 630 np->name, np->remote_port); 631 printk(KERN_INFO "%s: remote IP %pI4\n", 632 np->name, &np->remote_ip); 633 printk(KERN_INFO "%s: remote ethernet address %pM\n", 634 np->name, np->remote_mac); 635 } 636 EXPORT_SYMBOL(netpoll_print_options); 637 638 int netpoll_parse_options(struct netpoll *np, char *opt) 639 { 640 char *cur=opt, *delim; 641 642 if (*cur != '@') { 643 if ((delim = strchr(cur, '@')) == NULL) 644 goto parse_failed; 645 *delim = 0; 646 np->local_port = simple_strtol(cur, NULL, 10); 647 cur = delim; 648 } 649 cur++; 650 651 if (*cur != '/') { 652 if ((delim = strchr(cur, '/')) == NULL) 653 goto parse_failed; 654 *delim = 0; 655 np->local_ip = in_aton(cur); 656 cur = delim; 657 } 658 cur++; 659 660 if (*cur != ',') { 661 /* parse out dev name */ 662 if ((delim = strchr(cur, ',')) == NULL) 663 goto parse_failed; 664 *delim = 0; 665 strlcpy(np->dev_name, cur, sizeof(np->dev_name)); 666 cur = delim; 667 } 668 cur++; 669 670 if (*cur != '@') { 671 /* dst port */ 672 if ((delim = strchr(cur, '@')) == NULL) 673 goto parse_failed; 674 *delim = 0; 675 if (*cur == ' ' || *cur == '\t') 676 printk(KERN_INFO "%s: warning: whitespace" 677 "is not allowed\n", np->name); 678 np->remote_port = simple_strtol(cur, NULL, 10); 679 cur = delim; 680 } 681 cur++; 682 683 /* dst ip */ 684 if ((delim = strchr(cur, '/')) == NULL) 685 goto parse_failed; 686 *delim = 0; 687 np->remote_ip = in_aton(cur); 688 cur = delim + 1; 689 690 if (*cur != 0) { 691 /* MAC address */ 692 if ((delim = strchr(cur, ':')) == NULL) 693 goto parse_failed; 694 *delim = 0; 695 np->remote_mac[0] = simple_strtol(cur, NULL, 16); 696 cur = delim + 1; 697 if ((delim = strchr(cur, ':')) == NULL) 698 goto parse_failed; 699 *delim = 0; 700 np->remote_mac[1] = simple_strtol(cur, NULL, 16); 701 cur = delim + 1; 702 if ((delim = strchr(cur, ':')) == NULL) 703 goto parse_failed; 704 *delim = 0; 705 np->remote_mac[2] = simple_strtol(cur, NULL, 16); 706 cur = delim + 1; 707 if ((delim = strchr(cur, ':')) == NULL) 708 goto parse_failed; 709 *delim = 0; 710 np->remote_mac[3] = simple_strtol(cur, NULL, 16); 711 cur = delim + 1; 712 if ((delim = strchr(cur, ':')) == NULL) 713 goto parse_failed; 714 *delim = 0; 715 np->remote_mac[4] = simple_strtol(cur, NULL, 16); 716 cur = delim + 1; 717 np->remote_mac[5] = simple_strtol(cur, NULL, 16); 718 } 719 720 netpoll_print_options(np); 721 722 return 0; 723 724 parse_failed: 725 printk(KERN_INFO "%s: couldn't parse config at '%s'!\n", 726 np->name, cur); 727 return -1; 728 } 729 EXPORT_SYMBOL(netpoll_parse_options); 730 731 int __netpoll_setup(struct netpoll *np) 732 { 733 struct net_device *ndev = np->dev; 734 struct netpoll_info *npinfo; 735 const struct net_device_ops *ops; 736 unsigned long flags; 737 int err; 738 739 if ((ndev->priv_flags & IFF_DISABLE_NETPOLL) || 740 !ndev->netdev_ops->ndo_poll_controller) { 741 printk(KERN_ERR "%s: %s doesn't support polling, aborting.\n", 742 np->name, np->dev_name); 743 err = -ENOTSUPP; 744 goto out; 745 } 746 747 if (!ndev->npinfo) { 748 npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL); 749 if (!npinfo) { 750 err = -ENOMEM; 751 goto out; 752 } 753 754 npinfo->rx_flags = 0; 755 INIT_LIST_HEAD(&npinfo->rx_np); 756 757 spin_lock_init(&npinfo->rx_lock); 758 skb_queue_head_init(&npinfo->arp_tx); 759 skb_queue_head_init(&npinfo->txq); 760 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process); 761 762 atomic_set(&npinfo->refcnt, 1); 763 764 ops = np->dev->netdev_ops; 765 if (ops->ndo_netpoll_setup) { 766 err = ops->ndo_netpoll_setup(ndev, npinfo); 767 if (err) 768 goto free_npinfo; 769 } 770 } else { 771 npinfo = ndev->npinfo; 772 atomic_inc(&npinfo->refcnt); 773 } 774 775 npinfo->netpoll = np; 776 777 if (np->rx_hook) { 778 spin_lock_irqsave(&npinfo->rx_lock, flags); 779 npinfo->rx_flags |= NETPOLL_RX_ENABLED; 780 list_add_tail(&np->rx, &npinfo->rx_np); 781 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 782 } 783 784 /* last thing to do is link it to the net device structure */ 785 rcu_assign_pointer(ndev->npinfo, npinfo); 786 787 return 0; 788 789 free_npinfo: 790 kfree(npinfo); 791 out: 792 return err; 793 } 794 EXPORT_SYMBOL_GPL(__netpoll_setup); 795 796 int netpoll_setup(struct netpoll *np) 797 { 798 struct net_device *ndev = NULL; 799 struct in_device *in_dev; 800 int err; 801 802 if (np->dev_name) 803 ndev = dev_get_by_name(&init_net, np->dev_name); 804 if (!ndev) { 805 printk(KERN_ERR "%s: %s doesn't exist, aborting.\n", 806 np->name, np->dev_name); 807 return -ENODEV; 808 } 809 810 if (!netif_running(ndev)) { 811 unsigned long atmost, atleast; 812 813 printk(KERN_INFO "%s: device %s not up yet, forcing it\n", 814 np->name, np->dev_name); 815 816 rtnl_lock(); 817 err = dev_open(ndev); 818 rtnl_unlock(); 819 820 if (err) { 821 printk(KERN_ERR "%s: failed to open %s\n", 822 np->name, ndev->name); 823 goto put; 824 } 825 826 atleast = jiffies + HZ/10; 827 atmost = jiffies + carrier_timeout * HZ; 828 while (!netif_carrier_ok(ndev)) { 829 if (time_after(jiffies, atmost)) { 830 printk(KERN_NOTICE 831 "%s: timeout waiting for carrier\n", 832 np->name); 833 break; 834 } 835 msleep(1); 836 } 837 838 /* If carrier appears to come up instantly, we don't 839 * trust it and pause so that we don't pump all our 840 * queued console messages into the bitbucket. 841 */ 842 843 if (time_before(jiffies, atleast)) { 844 printk(KERN_NOTICE "%s: carrier detect appears" 845 " untrustworthy, waiting 4 seconds\n", 846 np->name); 847 msleep(4000); 848 } 849 } 850 851 if (!np->local_ip) { 852 rcu_read_lock(); 853 in_dev = __in_dev_get_rcu(ndev); 854 855 if (!in_dev || !in_dev->ifa_list) { 856 rcu_read_unlock(); 857 printk(KERN_ERR "%s: no IP address for %s, aborting\n", 858 np->name, np->dev_name); 859 err = -EDESTADDRREQ; 860 goto put; 861 } 862 863 np->local_ip = in_dev->ifa_list->ifa_local; 864 rcu_read_unlock(); 865 printk(KERN_INFO "%s: local IP %pI4\n", np->name, &np->local_ip); 866 } 867 868 np->dev = ndev; 869 870 /* fill up the skb queue */ 871 refill_skbs(); 872 873 rtnl_lock(); 874 err = __netpoll_setup(np); 875 rtnl_unlock(); 876 877 if (err) 878 goto put; 879 880 return 0; 881 882 put: 883 dev_put(ndev); 884 return err; 885 } 886 EXPORT_SYMBOL(netpoll_setup); 887 888 static int __init netpoll_init(void) 889 { 890 skb_queue_head_init(&skb_pool); 891 return 0; 892 } 893 core_initcall(netpoll_init); 894 895 void __netpoll_cleanup(struct netpoll *np) 896 { 897 struct netpoll_info *npinfo; 898 unsigned long flags; 899 900 npinfo = np->dev->npinfo; 901 if (!npinfo) 902 return; 903 904 if (!list_empty(&npinfo->rx_np)) { 905 spin_lock_irqsave(&npinfo->rx_lock, flags); 906 list_del(&np->rx); 907 if (list_empty(&npinfo->rx_np)) 908 npinfo->rx_flags &= ~NETPOLL_RX_ENABLED; 909 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 910 } 911 912 if (atomic_dec_and_test(&npinfo->refcnt)) { 913 const struct net_device_ops *ops; 914 915 ops = np->dev->netdev_ops; 916 if (ops->ndo_netpoll_cleanup) 917 ops->ndo_netpoll_cleanup(np->dev); 918 919 rcu_assign_pointer(np->dev->npinfo, NULL); 920 921 /* avoid racing with NAPI reading npinfo */ 922 synchronize_rcu_bh(); 923 924 skb_queue_purge(&npinfo->arp_tx); 925 skb_queue_purge(&npinfo->txq); 926 cancel_delayed_work_sync(&npinfo->tx_work); 927 928 /* clean after last, unfinished work */ 929 __skb_queue_purge(&npinfo->txq); 930 kfree(npinfo); 931 } 932 } 933 EXPORT_SYMBOL_GPL(__netpoll_cleanup); 934 935 void netpoll_cleanup(struct netpoll *np) 936 { 937 if (!np->dev) 938 return; 939 940 rtnl_lock(); 941 __netpoll_cleanup(np); 942 rtnl_unlock(); 943 944 dev_put(np->dev); 945 np->dev = NULL; 946 } 947 EXPORT_SYMBOL(netpoll_cleanup); 948 949 int netpoll_trap(void) 950 { 951 return atomic_read(&trapped); 952 } 953 EXPORT_SYMBOL(netpoll_trap); 954 955 void netpoll_set_trap(int trap) 956 { 957 if (trap) 958 atomic_inc(&trapped); 959 else 960 atomic_dec(&trapped); 961 } 962 EXPORT_SYMBOL(netpoll_set_trap); 963