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