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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 13 14 #include <linux/moduleparam.h> 15 #include <linux/netdevice.h> 16 #include <linux/etherdevice.h> 17 #include <linux/string.h> 18 #include <linux/if_arp.h> 19 #include <linux/inetdevice.h> 20 #include <linux/inet.h> 21 #include <linux/interrupt.h> 22 #include <linux/netpoll.h> 23 #include <linux/sched.h> 24 #include <linux/delay.h> 25 #include <linux/rcupdate.h> 26 #include <linux/workqueue.h> 27 #include <linux/slab.h> 28 #include <linux/export.h> 29 #include <linux/if_vlan.h> 30 #include <net/tcp.h> 31 #include <net/udp.h> 32 #include <asm/unaligned.h> 33 #include <trace/events/napi.h> 34 35 /* 36 * We maintain a small pool of fully-sized skbs, to make sure the 37 * message gets out even in extreme OOM situations. 38 */ 39 40 #define MAX_UDP_CHUNK 1460 41 #define MAX_SKBS 32 42 43 static struct sk_buff_head skb_pool; 44 45 static atomic_t trapped; 46 47 #define USEC_PER_POLL 50 48 #define NETPOLL_RX_ENABLED 1 49 #define NETPOLL_RX_DROP 2 50 51 #define MAX_SKB_SIZE \ 52 (sizeof(struct ethhdr) + \ 53 sizeof(struct iphdr) + \ 54 sizeof(struct udphdr) + \ 55 MAX_UDP_CHUNK) 56 57 static void zap_completion_queue(void); 58 static void netpoll_arp_reply(struct sk_buff *skb, struct netpoll_info *npinfo); 59 60 static unsigned int carrier_timeout = 4; 61 module_param(carrier_timeout, uint, 0644); 62 63 #define np_info(np, fmt, ...) \ 64 pr_info("%s: " fmt, np->name, ##__VA_ARGS__) 65 #define np_err(np, fmt, ...) \ 66 pr_err("%s: " fmt, np->name, ##__VA_ARGS__) 67 #define np_notice(np, fmt, ...) \ 68 pr_notice("%s: " fmt, np->name, ##__VA_ARGS__) 69 70 static void queue_process(struct work_struct *work) 71 { 72 struct netpoll_info *npinfo = 73 container_of(work, struct netpoll_info, tx_work.work); 74 struct sk_buff *skb; 75 unsigned long flags; 76 77 while ((skb = skb_dequeue(&npinfo->txq))) { 78 struct net_device *dev = skb->dev; 79 const struct net_device_ops *ops = dev->netdev_ops; 80 struct netdev_queue *txq; 81 82 if (!netif_device_present(dev) || !netif_running(dev)) { 83 __kfree_skb(skb); 84 continue; 85 } 86 87 txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb)); 88 89 local_irq_save(flags); 90 __netif_tx_lock(txq, smp_processor_id()); 91 if (netif_xmit_frozen_or_stopped(txq) || 92 ops->ndo_start_xmit(skb, dev) != NETDEV_TX_OK) { 93 skb_queue_head(&npinfo->txq, skb); 94 __netif_tx_unlock(txq); 95 local_irq_restore(flags); 96 97 schedule_delayed_work(&npinfo->tx_work, HZ/10); 98 return; 99 } 100 __netif_tx_unlock(txq); 101 local_irq_restore(flags); 102 } 103 } 104 105 static __sum16 checksum_udp(struct sk_buff *skb, struct udphdr *uh, 106 unsigned short ulen, __be32 saddr, __be32 daddr) 107 { 108 __wsum psum; 109 110 if (uh->check == 0 || skb_csum_unnecessary(skb)) 111 return 0; 112 113 psum = csum_tcpudp_nofold(saddr, daddr, ulen, IPPROTO_UDP, 0); 114 115 if (skb->ip_summed == CHECKSUM_COMPLETE && 116 !csum_fold(csum_add(psum, skb->csum))) 117 return 0; 118 119 skb->csum = psum; 120 121 return __skb_checksum_complete(skb); 122 } 123 124 /* 125 * Check whether delayed processing was scheduled for our NIC. If so, 126 * we attempt to grab the poll lock and use ->poll() to pump the card. 127 * If this fails, either we've recursed in ->poll() or it's already 128 * running on another CPU. 129 * 130 * Note: we don't mask interrupts with this lock because we're using 131 * trylock here and interrupts are already disabled in the softirq 132 * case. Further, we test the poll_owner to avoid recursion on UP 133 * systems where the lock doesn't exist. 134 * 135 * In cases where there is bi-directional communications, reading only 136 * one message at a time can lead to packets being dropped by the 137 * network adapter, forcing superfluous retries and possibly timeouts. 138 * Thus, we set our budget to greater than 1. 139 */ 140 static int poll_one_napi(struct netpoll_info *npinfo, 141 struct napi_struct *napi, int budget) 142 { 143 int work; 144 145 /* net_rx_action's ->poll() invocations and our's are 146 * synchronized by this test which is only made while 147 * holding the napi->poll_lock. 148 */ 149 if (!test_bit(NAPI_STATE_SCHED, &napi->state)) 150 return budget; 151 152 npinfo->rx_flags |= NETPOLL_RX_DROP; 153 atomic_inc(&trapped); 154 set_bit(NAPI_STATE_NPSVC, &napi->state); 155 156 work = napi->poll(napi, budget); 157 trace_napi_poll(napi); 158 159 clear_bit(NAPI_STATE_NPSVC, &napi->state); 160 atomic_dec(&trapped); 161 npinfo->rx_flags &= ~NETPOLL_RX_DROP; 162 163 return budget - work; 164 } 165 166 static void poll_napi(struct net_device *dev) 167 { 168 struct napi_struct *napi; 169 int budget = 16; 170 171 list_for_each_entry(napi, &dev->napi_list, dev_list) { 172 if (napi->poll_owner != smp_processor_id() && 173 spin_trylock(&napi->poll_lock)) { 174 budget = poll_one_napi(rcu_dereference_bh(dev->npinfo), 175 napi, budget); 176 spin_unlock(&napi->poll_lock); 177 178 if (!budget) 179 break; 180 } 181 } 182 } 183 184 static void service_arp_queue(struct netpoll_info *npi) 185 { 186 if (npi) { 187 struct sk_buff *skb; 188 189 while ((skb = skb_dequeue(&npi->arp_tx))) 190 netpoll_arp_reply(skb, npi); 191 } 192 } 193 194 static void netpoll_poll_dev(struct net_device *dev) 195 { 196 const struct net_device_ops *ops; 197 struct netpoll_info *ni = rcu_dereference_bh(dev->npinfo); 198 199 if (!dev || !netif_running(dev)) 200 return; 201 202 ops = dev->netdev_ops; 203 if (!ops->ndo_poll_controller) 204 return; 205 206 /* Process pending work on NIC */ 207 ops->ndo_poll_controller(dev); 208 209 poll_napi(dev); 210 211 if (dev->flags & IFF_SLAVE) { 212 if (ni) { 213 struct net_device *bond_dev = dev->master; 214 struct sk_buff *skb; 215 struct netpoll_info *bond_ni = rcu_dereference_bh(bond_dev->npinfo); 216 while ((skb = skb_dequeue(&ni->arp_tx))) { 217 skb->dev = bond_dev; 218 skb_queue_tail(&bond_ni->arp_tx, skb); 219 } 220 } 221 } 222 223 service_arp_queue(ni); 224 225 zap_completion_queue(); 226 } 227 228 static void refill_skbs(void) 229 { 230 struct sk_buff *skb; 231 unsigned long flags; 232 233 spin_lock_irqsave(&skb_pool.lock, flags); 234 while (skb_pool.qlen < MAX_SKBS) { 235 skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC); 236 if (!skb) 237 break; 238 239 __skb_queue_tail(&skb_pool, skb); 240 } 241 spin_unlock_irqrestore(&skb_pool.lock, flags); 242 } 243 244 static void zap_completion_queue(void) 245 { 246 unsigned long flags; 247 struct softnet_data *sd = &get_cpu_var(softnet_data); 248 249 if (sd->completion_queue) { 250 struct sk_buff *clist; 251 252 local_irq_save(flags); 253 clist = sd->completion_queue; 254 sd->completion_queue = NULL; 255 local_irq_restore(flags); 256 257 while (clist != NULL) { 258 struct sk_buff *skb = clist; 259 clist = clist->next; 260 if (skb->destructor) { 261 atomic_inc(&skb->users); 262 dev_kfree_skb_any(skb); /* put this one back */ 263 } else { 264 __kfree_skb(skb); 265 } 266 } 267 } 268 269 put_cpu_var(softnet_data); 270 } 271 272 static struct sk_buff *find_skb(struct netpoll *np, int len, int reserve) 273 { 274 int count = 0; 275 struct sk_buff *skb; 276 277 zap_completion_queue(); 278 refill_skbs(); 279 repeat: 280 281 skb = alloc_skb(len, GFP_ATOMIC); 282 if (!skb) 283 skb = skb_dequeue(&skb_pool); 284 285 if (!skb) { 286 if (++count < 10) { 287 netpoll_poll_dev(np->dev); 288 goto repeat; 289 } 290 return NULL; 291 } 292 293 atomic_set(&skb->users, 1); 294 skb_reserve(skb, reserve); 295 return skb; 296 } 297 298 static int netpoll_owner_active(struct net_device *dev) 299 { 300 struct napi_struct *napi; 301 302 list_for_each_entry(napi, &dev->napi_list, dev_list) { 303 if (napi->poll_owner == smp_processor_id()) 304 return 1; 305 } 306 return 0; 307 } 308 309 /* call with IRQ disabled */ 310 void netpoll_send_skb_on_dev(struct netpoll *np, struct sk_buff *skb, 311 struct net_device *dev) 312 { 313 int status = NETDEV_TX_BUSY; 314 unsigned long tries; 315 const struct net_device_ops *ops = dev->netdev_ops; 316 /* It is up to the caller to keep npinfo alive. */ 317 struct netpoll_info *npinfo; 318 319 WARN_ON_ONCE(!irqs_disabled()); 320 321 npinfo = rcu_dereference_bh(np->dev->npinfo); 322 if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) { 323 __kfree_skb(skb); 324 return; 325 } 326 327 /* don't get messages out of order, and no recursion */ 328 if (skb_queue_len(&npinfo->txq) == 0 && !netpoll_owner_active(dev)) { 329 struct netdev_queue *txq; 330 331 txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb)); 332 333 /* try until next clock tick */ 334 for (tries = jiffies_to_usecs(1)/USEC_PER_POLL; 335 tries > 0; --tries) { 336 if (__netif_tx_trylock(txq)) { 337 if (!netif_xmit_stopped(txq)) { 338 if (vlan_tx_tag_present(skb) && 339 !(netif_skb_features(skb) & NETIF_F_HW_VLAN_TX)) { 340 skb = __vlan_put_tag(skb, vlan_tx_tag_get(skb)); 341 if (unlikely(!skb)) 342 break; 343 skb->vlan_tci = 0; 344 } 345 346 status = ops->ndo_start_xmit(skb, dev); 347 if (status == NETDEV_TX_OK) 348 txq_trans_update(txq); 349 } 350 __netif_tx_unlock(txq); 351 352 if (status == NETDEV_TX_OK) 353 break; 354 355 } 356 357 /* tickle device maybe there is some cleanup */ 358 netpoll_poll_dev(np->dev); 359 360 udelay(USEC_PER_POLL); 361 } 362 363 WARN_ONCE(!irqs_disabled(), 364 "netpoll_send_skb_on_dev(): %s enabled interrupts in poll (%pF)\n", 365 dev->name, ops->ndo_start_xmit); 366 367 } 368 369 if (status != NETDEV_TX_OK) { 370 skb_queue_tail(&npinfo->txq, skb); 371 schedule_delayed_work(&npinfo->tx_work,0); 372 } 373 } 374 EXPORT_SYMBOL(netpoll_send_skb_on_dev); 375 376 void netpoll_send_udp(struct netpoll *np, const char *msg, int len) 377 { 378 int total_len, ip_len, udp_len; 379 struct sk_buff *skb; 380 struct udphdr *udph; 381 struct iphdr *iph; 382 struct ethhdr *eth; 383 384 udp_len = len + sizeof(*udph); 385 ip_len = udp_len + sizeof(*iph); 386 total_len = ip_len + LL_RESERVED_SPACE(np->dev); 387 388 skb = find_skb(np, total_len + np->dev->needed_tailroom, 389 total_len - len); 390 if (!skb) 391 return; 392 393 skb_copy_to_linear_data(skb, msg, len); 394 skb_put(skb, len); 395 396 skb_push(skb, sizeof(*udph)); 397 skb_reset_transport_header(skb); 398 udph = udp_hdr(skb); 399 udph->source = htons(np->local_port); 400 udph->dest = htons(np->remote_port); 401 udph->len = htons(udp_len); 402 udph->check = 0; 403 udph->check = csum_tcpudp_magic(np->local_ip, 404 np->remote_ip, 405 udp_len, IPPROTO_UDP, 406 csum_partial(udph, udp_len, 0)); 407 if (udph->check == 0) 408 udph->check = CSUM_MANGLED_0; 409 410 skb_push(skb, sizeof(*iph)); 411 skb_reset_network_header(skb); 412 iph = ip_hdr(skb); 413 414 /* iph->version = 4; iph->ihl = 5; */ 415 put_unaligned(0x45, (unsigned char *)iph); 416 iph->tos = 0; 417 put_unaligned(htons(ip_len), &(iph->tot_len)); 418 iph->id = 0; 419 iph->frag_off = 0; 420 iph->ttl = 64; 421 iph->protocol = IPPROTO_UDP; 422 iph->check = 0; 423 put_unaligned(np->local_ip, &(iph->saddr)); 424 put_unaligned(np->remote_ip, &(iph->daddr)); 425 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); 426 427 eth = (struct ethhdr *) skb_push(skb, ETH_HLEN); 428 skb_reset_mac_header(skb); 429 skb->protocol = eth->h_proto = htons(ETH_P_IP); 430 memcpy(eth->h_source, np->dev->dev_addr, ETH_ALEN); 431 memcpy(eth->h_dest, np->remote_mac, ETH_ALEN); 432 433 skb->dev = np->dev; 434 435 netpoll_send_skb(np, skb); 436 } 437 EXPORT_SYMBOL(netpoll_send_udp); 438 439 static void netpoll_arp_reply(struct sk_buff *skb, struct netpoll_info *npinfo) 440 { 441 struct arphdr *arp; 442 unsigned char *arp_ptr; 443 int size, type = ARPOP_REPLY, ptype = ETH_P_ARP; 444 __be32 sip, tip; 445 unsigned char *sha; 446 struct sk_buff *send_skb; 447 struct netpoll *np, *tmp; 448 unsigned long flags; 449 int hlen, tlen; 450 int hits = 0; 451 452 if (list_empty(&npinfo->rx_np)) 453 return; 454 455 /* Before checking the packet, we do some early 456 inspection whether this is interesting at all */ 457 spin_lock_irqsave(&npinfo->rx_lock, flags); 458 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) { 459 if (np->dev == skb->dev) 460 hits++; 461 } 462 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 463 464 /* No netpoll struct is using this dev */ 465 if (!hits) 466 return; 467 468 /* No arp on this interface */ 469 if (skb->dev->flags & IFF_NOARP) 470 return; 471 472 if (!pskb_may_pull(skb, arp_hdr_len(skb->dev))) 473 return; 474 475 skb_reset_network_header(skb); 476 skb_reset_transport_header(skb); 477 arp = arp_hdr(skb); 478 479 if ((arp->ar_hrd != htons(ARPHRD_ETHER) && 480 arp->ar_hrd != htons(ARPHRD_IEEE802)) || 481 arp->ar_pro != htons(ETH_P_IP) || 482 arp->ar_op != htons(ARPOP_REQUEST)) 483 return; 484 485 arp_ptr = (unsigned char *)(arp+1); 486 /* save the location of the src hw addr */ 487 sha = arp_ptr; 488 arp_ptr += skb->dev->addr_len; 489 memcpy(&sip, arp_ptr, 4); 490 arp_ptr += 4; 491 /* If we actually cared about dst hw addr, 492 it would get copied here */ 493 arp_ptr += skb->dev->addr_len; 494 memcpy(&tip, arp_ptr, 4); 495 496 /* Should we ignore arp? */ 497 if (ipv4_is_loopback(tip) || ipv4_is_multicast(tip)) 498 return; 499 500 size = arp_hdr_len(skb->dev); 501 502 spin_lock_irqsave(&npinfo->rx_lock, flags); 503 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) { 504 if (tip != np->local_ip) 505 continue; 506 507 hlen = LL_RESERVED_SPACE(np->dev); 508 tlen = np->dev->needed_tailroom; 509 send_skb = find_skb(np, size + hlen + tlen, hlen); 510 if (!send_skb) 511 continue; 512 513 skb_reset_network_header(send_skb); 514 arp = (struct arphdr *) skb_put(send_skb, size); 515 send_skb->dev = skb->dev; 516 send_skb->protocol = htons(ETH_P_ARP); 517 518 /* Fill the device header for the ARP frame */ 519 if (dev_hard_header(send_skb, skb->dev, ptype, 520 sha, np->dev->dev_addr, 521 send_skb->len) < 0) { 522 kfree_skb(send_skb); 523 continue; 524 } 525 526 /* 527 * Fill out the arp protocol part. 528 * 529 * we only support ethernet device type, 530 * which (according to RFC 1390) should 531 * always equal 1 (Ethernet). 532 */ 533 534 arp->ar_hrd = htons(np->dev->type); 535 arp->ar_pro = htons(ETH_P_IP); 536 arp->ar_hln = np->dev->addr_len; 537 arp->ar_pln = 4; 538 arp->ar_op = htons(type); 539 540 arp_ptr = (unsigned char *)(arp + 1); 541 memcpy(arp_ptr, np->dev->dev_addr, np->dev->addr_len); 542 arp_ptr += np->dev->addr_len; 543 memcpy(arp_ptr, &tip, 4); 544 arp_ptr += 4; 545 memcpy(arp_ptr, sha, np->dev->addr_len); 546 arp_ptr += np->dev->addr_len; 547 memcpy(arp_ptr, &sip, 4); 548 549 netpoll_send_skb(np, send_skb); 550 551 /* If there are several rx_hooks for the same address, 552 we're fine by sending a single reply */ 553 break; 554 } 555 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 556 } 557 558 int __netpoll_rx(struct sk_buff *skb, struct netpoll_info *npinfo) 559 { 560 int proto, len, ulen; 561 int hits = 0; 562 const struct iphdr *iph; 563 struct udphdr *uh; 564 struct netpoll *np, *tmp; 565 566 if (list_empty(&npinfo->rx_np)) 567 goto out; 568 569 if (skb->dev->type != ARPHRD_ETHER) 570 goto out; 571 572 /* check if netpoll clients need ARP */ 573 if (skb->protocol == htons(ETH_P_ARP) && 574 atomic_read(&trapped)) { 575 skb_queue_tail(&npinfo->arp_tx, skb); 576 return 1; 577 } 578 579 if (skb->protocol == cpu_to_be16(ETH_P_8021Q)) { 580 skb = vlan_untag(skb); 581 if (unlikely(!skb)) 582 goto out; 583 } 584 585 proto = ntohs(eth_hdr(skb)->h_proto); 586 if (proto != ETH_P_IP) 587 goto out; 588 if (skb->pkt_type == PACKET_OTHERHOST) 589 goto out; 590 if (skb_shared(skb)) 591 goto out; 592 593 if (!pskb_may_pull(skb, sizeof(struct iphdr))) 594 goto out; 595 iph = (struct iphdr *)skb->data; 596 if (iph->ihl < 5 || iph->version != 4) 597 goto out; 598 if (!pskb_may_pull(skb, iph->ihl*4)) 599 goto out; 600 iph = (struct iphdr *)skb->data; 601 if (ip_fast_csum((u8 *)iph, iph->ihl) != 0) 602 goto out; 603 604 len = ntohs(iph->tot_len); 605 if (skb->len < len || len < iph->ihl*4) 606 goto out; 607 608 /* 609 * Our transport medium may have padded the buffer out. 610 * Now We trim to the true length of the frame. 611 */ 612 if (pskb_trim_rcsum(skb, len)) 613 goto out; 614 615 iph = (struct iphdr *)skb->data; 616 if (iph->protocol != IPPROTO_UDP) 617 goto out; 618 619 len -= iph->ihl*4; 620 uh = (struct udphdr *)(((char *)iph) + iph->ihl*4); 621 ulen = ntohs(uh->len); 622 623 if (ulen != len) 624 goto out; 625 if (checksum_udp(skb, uh, ulen, iph->saddr, iph->daddr)) 626 goto out; 627 628 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) { 629 if (np->local_ip && np->local_ip != iph->daddr) 630 continue; 631 if (np->remote_ip && np->remote_ip != iph->saddr) 632 continue; 633 if (np->local_port && np->local_port != ntohs(uh->dest)) 634 continue; 635 636 np->rx_hook(np, ntohs(uh->source), 637 (char *)(uh+1), 638 ulen - sizeof(struct udphdr)); 639 hits++; 640 } 641 642 if (!hits) 643 goto out; 644 645 kfree_skb(skb); 646 return 1; 647 648 out: 649 if (atomic_read(&trapped)) { 650 kfree_skb(skb); 651 return 1; 652 } 653 654 return 0; 655 } 656 657 void netpoll_print_options(struct netpoll *np) 658 { 659 np_info(np, "local port %d\n", np->local_port); 660 np_info(np, "local IP %pI4\n", &np->local_ip); 661 np_info(np, "interface '%s'\n", np->dev_name); 662 np_info(np, "remote port %d\n", np->remote_port); 663 np_info(np, "remote IP %pI4\n", &np->remote_ip); 664 np_info(np, "remote ethernet address %pM\n", np->remote_mac); 665 } 666 EXPORT_SYMBOL(netpoll_print_options); 667 668 int netpoll_parse_options(struct netpoll *np, char *opt) 669 { 670 char *cur=opt, *delim; 671 672 if (*cur != '@') { 673 if ((delim = strchr(cur, '@')) == NULL) 674 goto parse_failed; 675 *delim = 0; 676 np->local_port = simple_strtol(cur, NULL, 10); 677 cur = delim; 678 } 679 cur++; 680 681 if (*cur != '/') { 682 if ((delim = strchr(cur, '/')) == NULL) 683 goto parse_failed; 684 *delim = 0; 685 np->local_ip = in_aton(cur); 686 cur = delim; 687 } 688 cur++; 689 690 if (*cur != ',') { 691 /* parse out dev name */ 692 if ((delim = strchr(cur, ',')) == NULL) 693 goto parse_failed; 694 *delim = 0; 695 strlcpy(np->dev_name, cur, sizeof(np->dev_name)); 696 cur = delim; 697 } 698 cur++; 699 700 if (*cur != '@') { 701 /* dst port */ 702 if ((delim = strchr(cur, '@')) == NULL) 703 goto parse_failed; 704 *delim = 0; 705 if (*cur == ' ' || *cur == '\t') 706 np_info(np, "warning: whitespace is not allowed\n"); 707 np->remote_port = simple_strtol(cur, NULL, 10); 708 cur = delim; 709 } 710 cur++; 711 712 /* dst ip */ 713 if ((delim = strchr(cur, '/')) == NULL) 714 goto parse_failed; 715 *delim = 0; 716 np->remote_ip = in_aton(cur); 717 cur = delim + 1; 718 719 if (*cur != 0) { 720 /* MAC address */ 721 if (!mac_pton(cur, np->remote_mac)) 722 goto parse_failed; 723 } 724 725 netpoll_print_options(np); 726 727 return 0; 728 729 parse_failed: 730 np_info(np, "couldn't parse config at '%s'!\n", cur); 731 return -1; 732 } 733 EXPORT_SYMBOL(netpoll_parse_options); 734 735 int __netpoll_setup(struct netpoll *np, struct net_device *ndev, gfp_t gfp) 736 { 737 struct netpoll_info *npinfo; 738 const struct net_device_ops *ops; 739 unsigned long flags; 740 int err; 741 742 np->dev = ndev; 743 strlcpy(np->dev_name, ndev->name, IFNAMSIZ); 744 745 if ((ndev->priv_flags & IFF_DISABLE_NETPOLL) || 746 !ndev->netdev_ops->ndo_poll_controller) { 747 np_err(np, "%s doesn't support polling, aborting\n", 748 np->dev_name); 749 err = -ENOTSUPP; 750 goto out; 751 } 752 753 if (!ndev->npinfo) { 754 npinfo = kmalloc(sizeof(*npinfo), gfp); 755 if (!npinfo) { 756 err = -ENOMEM; 757 goto out; 758 } 759 760 npinfo->rx_flags = 0; 761 INIT_LIST_HEAD(&npinfo->rx_np); 762 763 spin_lock_init(&npinfo->rx_lock); 764 skb_queue_head_init(&npinfo->arp_tx); 765 skb_queue_head_init(&npinfo->txq); 766 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process); 767 768 atomic_set(&npinfo->refcnt, 1); 769 770 ops = np->dev->netdev_ops; 771 if (ops->ndo_netpoll_setup) { 772 err = ops->ndo_netpoll_setup(ndev, npinfo, gfp); 773 if (err) 774 goto free_npinfo; 775 } 776 } else { 777 npinfo = ndev->npinfo; 778 atomic_inc(&npinfo->refcnt); 779 } 780 781 npinfo->netpoll = np; 782 783 if (np->rx_hook) { 784 spin_lock_irqsave(&npinfo->rx_lock, flags); 785 npinfo->rx_flags |= NETPOLL_RX_ENABLED; 786 list_add_tail(&np->rx, &npinfo->rx_np); 787 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 788 } 789 790 /* last thing to do is link it to the net device structure */ 791 rcu_assign_pointer(ndev->npinfo, npinfo); 792 793 return 0; 794 795 free_npinfo: 796 kfree(npinfo); 797 out: 798 return err; 799 } 800 EXPORT_SYMBOL_GPL(__netpoll_setup); 801 802 int netpoll_setup(struct netpoll *np) 803 { 804 struct net_device *ndev = NULL; 805 struct in_device *in_dev; 806 int err; 807 808 if (np->dev_name) 809 ndev = dev_get_by_name(&init_net, np->dev_name); 810 if (!ndev) { 811 np_err(np, "%s doesn't exist, aborting\n", np->dev_name); 812 return -ENODEV; 813 } 814 815 if (ndev->master) { 816 np_err(np, "%s is a slave device, aborting\n", np->dev_name); 817 err = -EBUSY; 818 goto put; 819 } 820 821 if (!netif_running(ndev)) { 822 unsigned long atmost, atleast; 823 824 np_info(np, "device %s not up yet, forcing it\n", np->dev_name); 825 826 rtnl_lock(); 827 err = dev_open(ndev); 828 rtnl_unlock(); 829 830 if (err) { 831 np_err(np, "failed to open %s\n", ndev->name); 832 goto put; 833 } 834 835 atleast = jiffies + HZ/10; 836 atmost = jiffies + carrier_timeout * HZ; 837 while (!netif_carrier_ok(ndev)) { 838 if (time_after(jiffies, atmost)) { 839 np_notice(np, "timeout waiting for carrier\n"); 840 break; 841 } 842 msleep(1); 843 } 844 845 /* If carrier appears to come up instantly, we don't 846 * trust it and pause so that we don't pump all our 847 * queued console messages into the bitbucket. 848 */ 849 850 if (time_before(jiffies, atleast)) { 851 np_notice(np, "carrier detect appears untrustworthy, waiting 4 seconds\n"); 852 msleep(4000); 853 } 854 } 855 856 if (!np->local_ip) { 857 rcu_read_lock(); 858 in_dev = __in_dev_get_rcu(ndev); 859 860 if (!in_dev || !in_dev->ifa_list) { 861 rcu_read_unlock(); 862 np_err(np, "no IP address for %s, aborting\n", 863 np->dev_name); 864 err = -EDESTADDRREQ; 865 goto put; 866 } 867 868 np->local_ip = in_dev->ifa_list->ifa_local; 869 rcu_read_unlock(); 870 np_info(np, "local IP %pI4\n", &np->local_ip); 871 } 872 873 /* fill up the skb queue */ 874 refill_skbs(); 875 876 rtnl_lock(); 877 err = __netpoll_setup(np, ndev, GFP_KERNEL); 878 rtnl_unlock(); 879 880 if (err) 881 goto put; 882 883 return 0; 884 885 put: 886 dev_put(ndev); 887 return err; 888 } 889 EXPORT_SYMBOL(netpoll_setup); 890 891 static int __init netpoll_init(void) 892 { 893 skb_queue_head_init(&skb_pool); 894 return 0; 895 } 896 core_initcall(netpoll_init); 897 898 static void rcu_cleanup_netpoll_info(struct rcu_head *rcu_head) 899 { 900 struct netpoll_info *npinfo = 901 container_of(rcu_head, struct netpoll_info, rcu); 902 903 skb_queue_purge(&npinfo->arp_tx); 904 skb_queue_purge(&npinfo->txq); 905 906 /* we can't call cancel_delayed_work_sync here, as we are in softirq */ 907 cancel_delayed_work(&npinfo->tx_work); 908 909 /* clean after last, unfinished work */ 910 __skb_queue_purge(&npinfo->txq); 911 /* now cancel it again */ 912 cancel_delayed_work(&npinfo->tx_work); 913 kfree(npinfo); 914 } 915 916 void __netpoll_cleanup(struct netpoll *np) 917 { 918 struct netpoll_info *npinfo; 919 unsigned long flags; 920 921 npinfo = np->dev->npinfo; 922 if (!npinfo) 923 return; 924 925 if (!list_empty(&npinfo->rx_np)) { 926 spin_lock_irqsave(&npinfo->rx_lock, flags); 927 list_del(&np->rx); 928 if (list_empty(&npinfo->rx_np)) 929 npinfo->rx_flags &= ~NETPOLL_RX_ENABLED; 930 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 931 } 932 933 if (atomic_dec_and_test(&npinfo->refcnt)) { 934 const struct net_device_ops *ops; 935 936 ops = np->dev->netdev_ops; 937 if (ops->ndo_netpoll_cleanup) 938 ops->ndo_netpoll_cleanup(np->dev); 939 940 RCU_INIT_POINTER(np->dev->npinfo, NULL); 941 call_rcu_bh(&npinfo->rcu, rcu_cleanup_netpoll_info); 942 } 943 } 944 EXPORT_SYMBOL_GPL(__netpoll_cleanup); 945 946 static void rcu_cleanup_netpoll(struct rcu_head *rcu_head) 947 { 948 struct netpoll *np = container_of(rcu_head, struct netpoll, rcu); 949 950 __netpoll_cleanup(np); 951 kfree(np); 952 } 953 954 void __netpoll_free_rcu(struct netpoll *np) 955 { 956 call_rcu_bh(&np->rcu, rcu_cleanup_netpoll); 957 } 958 EXPORT_SYMBOL_GPL(__netpoll_free_rcu); 959 960 void netpoll_cleanup(struct netpoll *np) 961 { 962 if (!np->dev) 963 return; 964 965 rtnl_lock(); 966 __netpoll_cleanup(np); 967 rtnl_unlock(); 968 969 dev_put(np->dev); 970 np->dev = NULL; 971 } 972 EXPORT_SYMBOL(netpoll_cleanup); 973 974 int netpoll_trap(void) 975 { 976 return atomic_read(&trapped); 977 } 978 EXPORT_SYMBOL(netpoll_trap); 979 980 void netpoll_set_trap(int trap) 981 { 982 if (trap) 983 atomic_inc(&trapped); 984 else 985 atomic_dec(&trapped); 986 } 987 EXPORT_SYMBOL(netpoll_set_trap); 988