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 WARN_ON_ONCE(!irqs_disabled()); 172 173 list_for_each_entry(napi, &dev->napi_list, dev_list) { 174 local_irq_enable(); 175 if (napi->poll_owner != smp_processor_id() && 176 spin_trylock(&napi->poll_lock)) { 177 rcu_read_lock_bh(); 178 budget = poll_one_napi(rcu_dereference_bh(dev->npinfo), 179 napi, budget); 180 rcu_read_unlock_bh(); 181 spin_unlock(&napi->poll_lock); 182 183 if (!budget) { 184 local_irq_disable(); 185 break; 186 } 187 } 188 local_irq_disable(); 189 } 190 } 191 192 static void service_arp_queue(struct netpoll_info *npi) 193 { 194 if (npi) { 195 struct sk_buff *skb; 196 197 while ((skb = skb_dequeue(&npi->arp_tx))) 198 netpoll_arp_reply(skb, npi); 199 } 200 } 201 202 static void netpoll_poll_dev(struct net_device *dev) 203 { 204 const struct net_device_ops *ops; 205 struct netpoll_info *ni = rcu_dereference_bh(dev->npinfo); 206 207 if (!dev || !netif_running(dev)) 208 return; 209 210 ops = dev->netdev_ops; 211 if (!ops->ndo_poll_controller) 212 return; 213 214 /* Process pending work on NIC */ 215 ops->ndo_poll_controller(dev); 216 217 poll_napi(dev); 218 219 if (dev->flags & IFF_SLAVE) { 220 if (ni) { 221 struct net_device *bond_dev = dev->master; 222 struct sk_buff *skb; 223 struct netpoll_info *bond_ni = rcu_dereference_bh(bond_dev->npinfo); 224 while ((skb = skb_dequeue(&ni->arp_tx))) { 225 skb->dev = bond_dev; 226 skb_queue_tail(&bond_ni->arp_tx, skb); 227 } 228 } 229 } 230 231 service_arp_queue(ni); 232 233 zap_completion_queue(); 234 } 235 236 static void refill_skbs(void) 237 { 238 struct sk_buff *skb; 239 unsigned long flags; 240 241 spin_lock_irqsave(&skb_pool.lock, flags); 242 while (skb_pool.qlen < MAX_SKBS) { 243 skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC); 244 if (!skb) 245 break; 246 247 __skb_queue_tail(&skb_pool, skb); 248 } 249 spin_unlock_irqrestore(&skb_pool.lock, flags); 250 } 251 252 static void zap_completion_queue(void) 253 { 254 unsigned long flags; 255 struct softnet_data *sd = &get_cpu_var(softnet_data); 256 257 if (sd->completion_queue) { 258 struct sk_buff *clist; 259 260 local_irq_save(flags); 261 clist = sd->completion_queue; 262 sd->completion_queue = NULL; 263 local_irq_restore(flags); 264 265 while (clist != NULL) { 266 struct sk_buff *skb = clist; 267 clist = clist->next; 268 if (skb->destructor) { 269 atomic_inc(&skb->users); 270 dev_kfree_skb_any(skb); /* put this one back */ 271 } else { 272 __kfree_skb(skb); 273 } 274 } 275 } 276 277 put_cpu_var(softnet_data); 278 } 279 280 static struct sk_buff *find_skb(struct netpoll *np, int len, int reserve) 281 { 282 int count = 0; 283 struct sk_buff *skb; 284 285 zap_completion_queue(); 286 refill_skbs(); 287 repeat: 288 289 skb = alloc_skb(len, GFP_ATOMIC); 290 if (!skb) 291 skb = skb_dequeue(&skb_pool); 292 293 if (!skb) { 294 if (++count < 10) { 295 netpoll_poll_dev(np->dev); 296 goto repeat; 297 } 298 return NULL; 299 } 300 301 atomic_set(&skb->users, 1); 302 skb_reserve(skb, reserve); 303 return skb; 304 } 305 306 static int netpoll_owner_active(struct net_device *dev) 307 { 308 struct napi_struct *napi; 309 310 list_for_each_entry(napi, &dev->napi_list, dev_list) { 311 if (napi->poll_owner == smp_processor_id()) 312 return 1; 313 } 314 return 0; 315 } 316 317 /* call with IRQ disabled */ 318 void netpoll_send_skb_on_dev(struct netpoll *np, struct sk_buff *skb, 319 struct net_device *dev) 320 { 321 int status = NETDEV_TX_BUSY; 322 unsigned long tries; 323 const struct net_device_ops *ops = dev->netdev_ops; 324 /* It is up to the caller to keep npinfo alive. */ 325 struct netpoll_info *npinfo; 326 327 WARN_ON_ONCE(!irqs_disabled()); 328 329 npinfo = rcu_dereference_bh(np->dev->npinfo); 330 if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) { 331 __kfree_skb(skb); 332 return; 333 } 334 335 /* don't get messages out of order, and no recursion */ 336 if (skb_queue_len(&npinfo->txq) == 0 && !netpoll_owner_active(dev)) { 337 struct netdev_queue *txq; 338 339 txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb)); 340 341 /* try until next clock tick */ 342 for (tries = jiffies_to_usecs(1)/USEC_PER_POLL; 343 tries > 0; --tries) { 344 if (__netif_tx_trylock(txq)) { 345 if (!netif_xmit_stopped(txq)) { 346 if (vlan_tx_tag_present(skb) && 347 !(netif_skb_features(skb) & NETIF_F_HW_VLAN_TX)) { 348 skb = __vlan_put_tag(skb, vlan_tx_tag_get(skb)); 349 if (unlikely(!skb)) 350 break; 351 skb->vlan_tci = 0; 352 } 353 354 status = ops->ndo_start_xmit(skb, dev); 355 if (status == NETDEV_TX_OK) 356 txq_trans_update(txq); 357 } 358 __netif_tx_unlock(txq); 359 360 if (status == NETDEV_TX_OK) 361 break; 362 363 } 364 365 /* tickle device maybe there is some cleanup */ 366 netpoll_poll_dev(np->dev); 367 368 udelay(USEC_PER_POLL); 369 } 370 371 WARN_ONCE(!irqs_disabled(), 372 "netpoll_send_skb_on_dev(): %s enabled interrupts in poll (%pF)\n", 373 dev->name, ops->ndo_start_xmit); 374 375 } 376 377 if (status != NETDEV_TX_OK) { 378 skb_queue_tail(&npinfo->txq, skb); 379 schedule_delayed_work(&npinfo->tx_work,0); 380 } 381 } 382 EXPORT_SYMBOL(netpoll_send_skb_on_dev); 383 384 void netpoll_send_udp(struct netpoll *np, const char *msg, int len) 385 { 386 int total_len, ip_len, udp_len; 387 struct sk_buff *skb; 388 struct udphdr *udph; 389 struct iphdr *iph; 390 struct ethhdr *eth; 391 392 udp_len = len + sizeof(*udph); 393 ip_len = udp_len + sizeof(*iph); 394 total_len = ip_len + LL_RESERVED_SPACE(np->dev); 395 396 skb = find_skb(np, total_len + np->dev->needed_tailroom, 397 total_len - len); 398 if (!skb) 399 return; 400 401 skb_copy_to_linear_data(skb, msg, len); 402 skb_put(skb, len); 403 404 skb_push(skb, sizeof(*udph)); 405 skb_reset_transport_header(skb); 406 udph = udp_hdr(skb); 407 udph->source = htons(np->local_port); 408 udph->dest = htons(np->remote_port); 409 udph->len = htons(udp_len); 410 udph->check = 0; 411 udph->check = csum_tcpudp_magic(np->local_ip, 412 np->remote_ip, 413 udp_len, IPPROTO_UDP, 414 csum_partial(udph, udp_len, 0)); 415 if (udph->check == 0) 416 udph->check = CSUM_MANGLED_0; 417 418 skb_push(skb, sizeof(*iph)); 419 skb_reset_network_header(skb); 420 iph = ip_hdr(skb); 421 422 /* iph->version = 4; iph->ihl = 5; */ 423 put_unaligned(0x45, (unsigned char *)iph); 424 iph->tos = 0; 425 put_unaligned(htons(ip_len), &(iph->tot_len)); 426 iph->id = 0; 427 iph->frag_off = 0; 428 iph->ttl = 64; 429 iph->protocol = IPPROTO_UDP; 430 iph->check = 0; 431 put_unaligned(np->local_ip, &(iph->saddr)); 432 put_unaligned(np->remote_ip, &(iph->daddr)); 433 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); 434 435 eth = (struct ethhdr *) skb_push(skb, ETH_HLEN); 436 skb_reset_mac_header(skb); 437 skb->protocol = eth->h_proto = htons(ETH_P_IP); 438 memcpy(eth->h_source, np->dev->dev_addr, ETH_ALEN); 439 memcpy(eth->h_dest, np->remote_mac, ETH_ALEN); 440 441 skb->dev = np->dev; 442 443 netpoll_send_skb(np, skb); 444 } 445 EXPORT_SYMBOL(netpoll_send_udp); 446 447 static void netpoll_arp_reply(struct sk_buff *skb, struct netpoll_info *npinfo) 448 { 449 struct arphdr *arp; 450 unsigned char *arp_ptr; 451 int size, type = ARPOP_REPLY, ptype = ETH_P_ARP; 452 __be32 sip, tip; 453 unsigned char *sha; 454 struct sk_buff *send_skb; 455 struct netpoll *np, *tmp; 456 unsigned long flags; 457 int hlen, tlen; 458 int hits = 0; 459 460 if (list_empty(&npinfo->rx_np)) 461 return; 462 463 /* Before checking the packet, we do some early 464 inspection whether this is interesting at all */ 465 spin_lock_irqsave(&npinfo->rx_lock, flags); 466 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) { 467 if (np->dev == skb->dev) 468 hits++; 469 } 470 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 471 472 /* No netpoll struct is using this dev */ 473 if (!hits) 474 return; 475 476 /* No arp on this interface */ 477 if (skb->dev->flags & IFF_NOARP) 478 return; 479 480 if (!pskb_may_pull(skb, arp_hdr_len(skb->dev))) 481 return; 482 483 skb_reset_network_header(skb); 484 skb_reset_transport_header(skb); 485 arp = arp_hdr(skb); 486 487 if ((arp->ar_hrd != htons(ARPHRD_ETHER) && 488 arp->ar_hrd != htons(ARPHRD_IEEE802)) || 489 arp->ar_pro != htons(ETH_P_IP) || 490 arp->ar_op != htons(ARPOP_REQUEST)) 491 return; 492 493 arp_ptr = (unsigned char *)(arp+1); 494 /* save the location of the src hw addr */ 495 sha = arp_ptr; 496 arp_ptr += skb->dev->addr_len; 497 memcpy(&sip, arp_ptr, 4); 498 arp_ptr += 4; 499 /* If we actually cared about dst hw addr, 500 it would get copied here */ 501 arp_ptr += skb->dev->addr_len; 502 memcpy(&tip, arp_ptr, 4); 503 504 /* Should we ignore arp? */ 505 if (ipv4_is_loopback(tip) || ipv4_is_multicast(tip)) 506 return; 507 508 size = arp_hdr_len(skb->dev); 509 510 spin_lock_irqsave(&npinfo->rx_lock, flags); 511 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) { 512 if (tip != np->local_ip) 513 continue; 514 515 hlen = LL_RESERVED_SPACE(np->dev); 516 tlen = np->dev->needed_tailroom; 517 send_skb = find_skb(np, size + hlen + tlen, hlen); 518 if (!send_skb) 519 continue; 520 521 skb_reset_network_header(send_skb); 522 arp = (struct arphdr *) skb_put(send_skb, size); 523 send_skb->dev = skb->dev; 524 send_skb->protocol = htons(ETH_P_ARP); 525 526 /* Fill the device header for the ARP frame */ 527 if (dev_hard_header(send_skb, skb->dev, ptype, 528 sha, np->dev->dev_addr, 529 send_skb->len) < 0) { 530 kfree_skb(send_skb); 531 continue; 532 } 533 534 /* 535 * Fill out the arp protocol part. 536 * 537 * we only support ethernet device type, 538 * which (according to RFC 1390) should 539 * always equal 1 (Ethernet). 540 */ 541 542 arp->ar_hrd = htons(np->dev->type); 543 arp->ar_pro = htons(ETH_P_IP); 544 arp->ar_hln = np->dev->addr_len; 545 arp->ar_pln = 4; 546 arp->ar_op = htons(type); 547 548 arp_ptr = (unsigned char *)(arp + 1); 549 memcpy(arp_ptr, np->dev->dev_addr, np->dev->addr_len); 550 arp_ptr += np->dev->addr_len; 551 memcpy(arp_ptr, &tip, 4); 552 arp_ptr += 4; 553 memcpy(arp_ptr, sha, np->dev->addr_len); 554 arp_ptr += np->dev->addr_len; 555 memcpy(arp_ptr, &sip, 4); 556 557 netpoll_send_skb(np, send_skb); 558 559 /* If there are several rx_hooks for the same address, 560 we're fine by sending a single reply */ 561 break; 562 } 563 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 564 } 565 566 int __netpoll_rx(struct sk_buff *skb, struct netpoll_info *npinfo) 567 { 568 int proto, len, ulen; 569 int hits = 0; 570 const struct iphdr *iph; 571 struct udphdr *uh; 572 struct netpoll *np, *tmp; 573 574 if (list_empty(&npinfo->rx_np)) 575 goto out; 576 577 if (skb->dev->type != ARPHRD_ETHER) 578 goto out; 579 580 /* check if netpoll clients need ARP */ 581 if (skb->protocol == htons(ETH_P_ARP) && 582 atomic_read(&trapped)) { 583 skb_queue_tail(&npinfo->arp_tx, skb); 584 return 1; 585 } 586 587 if (skb->protocol == cpu_to_be16(ETH_P_8021Q)) { 588 skb = vlan_untag(skb); 589 if (unlikely(!skb)) 590 goto out; 591 } 592 593 proto = ntohs(eth_hdr(skb)->h_proto); 594 if (proto != ETH_P_IP) 595 goto out; 596 if (skb->pkt_type == PACKET_OTHERHOST) 597 goto out; 598 if (skb_shared(skb)) 599 goto out; 600 601 if (!pskb_may_pull(skb, sizeof(struct iphdr))) 602 goto out; 603 iph = (struct iphdr *)skb->data; 604 if (iph->ihl < 5 || iph->version != 4) 605 goto out; 606 if (!pskb_may_pull(skb, iph->ihl*4)) 607 goto out; 608 iph = (struct iphdr *)skb->data; 609 if (ip_fast_csum((u8 *)iph, iph->ihl) != 0) 610 goto out; 611 612 len = ntohs(iph->tot_len); 613 if (skb->len < len || len < iph->ihl*4) 614 goto out; 615 616 /* 617 * Our transport medium may have padded the buffer out. 618 * Now We trim to the true length of the frame. 619 */ 620 if (pskb_trim_rcsum(skb, len)) 621 goto out; 622 623 iph = (struct iphdr *)skb->data; 624 if (iph->protocol != IPPROTO_UDP) 625 goto out; 626 627 len -= iph->ihl*4; 628 uh = (struct udphdr *)(((char *)iph) + iph->ihl*4); 629 ulen = ntohs(uh->len); 630 631 if (ulen != len) 632 goto out; 633 if (checksum_udp(skb, uh, ulen, iph->saddr, iph->daddr)) 634 goto out; 635 636 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) { 637 if (np->local_ip && np->local_ip != iph->daddr) 638 continue; 639 if (np->remote_ip && np->remote_ip != iph->saddr) 640 continue; 641 if (np->local_port && np->local_port != ntohs(uh->dest)) 642 continue; 643 644 np->rx_hook(np, ntohs(uh->source), 645 (char *)(uh+1), 646 ulen - sizeof(struct udphdr)); 647 hits++; 648 } 649 650 if (!hits) 651 goto out; 652 653 kfree_skb(skb); 654 return 1; 655 656 out: 657 if (atomic_read(&trapped)) { 658 kfree_skb(skb); 659 return 1; 660 } 661 662 return 0; 663 } 664 665 void netpoll_print_options(struct netpoll *np) 666 { 667 np_info(np, "local port %d\n", np->local_port); 668 np_info(np, "local IP %pI4\n", &np->local_ip); 669 np_info(np, "interface '%s'\n", np->dev_name); 670 np_info(np, "remote port %d\n", np->remote_port); 671 np_info(np, "remote IP %pI4\n", &np->remote_ip); 672 np_info(np, "remote ethernet address %pM\n", np->remote_mac); 673 } 674 EXPORT_SYMBOL(netpoll_print_options); 675 676 int netpoll_parse_options(struct netpoll *np, char *opt) 677 { 678 char *cur=opt, *delim; 679 680 if (*cur != '@') { 681 if ((delim = strchr(cur, '@')) == NULL) 682 goto parse_failed; 683 *delim = 0; 684 np->local_port = simple_strtol(cur, NULL, 10); 685 cur = delim; 686 } 687 cur++; 688 689 if (*cur != '/') { 690 if ((delim = strchr(cur, '/')) == NULL) 691 goto parse_failed; 692 *delim = 0; 693 np->local_ip = in_aton(cur); 694 cur = delim; 695 } 696 cur++; 697 698 if (*cur != ',') { 699 /* parse out dev name */ 700 if ((delim = strchr(cur, ',')) == NULL) 701 goto parse_failed; 702 *delim = 0; 703 strlcpy(np->dev_name, cur, sizeof(np->dev_name)); 704 cur = delim; 705 } 706 cur++; 707 708 if (*cur != '@') { 709 /* dst port */ 710 if ((delim = strchr(cur, '@')) == NULL) 711 goto parse_failed; 712 *delim = 0; 713 if (*cur == ' ' || *cur == '\t') 714 np_info(np, "warning: whitespace is not allowed\n"); 715 np->remote_port = simple_strtol(cur, NULL, 10); 716 cur = delim; 717 } 718 cur++; 719 720 /* dst ip */ 721 if ((delim = strchr(cur, '/')) == NULL) 722 goto parse_failed; 723 *delim = 0; 724 np->remote_ip = in_aton(cur); 725 cur = delim + 1; 726 727 if (*cur != 0) { 728 /* MAC address */ 729 if (!mac_pton(cur, np->remote_mac)) 730 goto parse_failed; 731 } 732 733 netpoll_print_options(np); 734 735 return 0; 736 737 parse_failed: 738 np_info(np, "couldn't parse config at '%s'!\n", cur); 739 return -1; 740 } 741 EXPORT_SYMBOL(netpoll_parse_options); 742 743 int __netpoll_setup(struct netpoll *np, struct net_device *ndev, gfp_t gfp) 744 { 745 struct netpoll_info *npinfo; 746 const struct net_device_ops *ops; 747 unsigned long flags; 748 int err; 749 750 np->dev = ndev; 751 strlcpy(np->dev_name, ndev->name, IFNAMSIZ); 752 753 if ((ndev->priv_flags & IFF_DISABLE_NETPOLL) || 754 !ndev->netdev_ops->ndo_poll_controller) { 755 np_err(np, "%s doesn't support polling, aborting\n", 756 np->dev_name); 757 err = -ENOTSUPP; 758 goto out; 759 } 760 761 if (!ndev->npinfo) { 762 npinfo = kmalloc(sizeof(*npinfo), gfp); 763 if (!npinfo) { 764 err = -ENOMEM; 765 goto out; 766 } 767 768 npinfo->rx_flags = 0; 769 INIT_LIST_HEAD(&npinfo->rx_np); 770 771 spin_lock_init(&npinfo->rx_lock); 772 skb_queue_head_init(&npinfo->arp_tx); 773 skb_queue_head_init(&npinfo->txq); 774 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process); 775 776 atomic_set(&npinfo->refcnt, 1); 777 778 ops = np->dev->netdev_ops; 779 if (ops->ndo_netpoll_setup) { 780 err = ops->ndo_netpoll_setup(ndev, npinfo, gfp); 781 if (err) 782 goto free_npinfo; 783 } 784 } else { 785 npinfo = ndev->npinfo; 786 atomic_inc(&npinfo->refcnt); 787 } 788 789 npinfo->netpoll = np; 790 791 if (np->rx_hook) { 792 spin_lock_irqsave(&npinfo->rx_lock, flags); 793 npinfo->rx_flags |= NETPOLL_RX_ENABLED; 794 list_add_tail(&np->rx, &npinfo->rx_np); 795 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 796 } 797 798 /* last thing to do is link it to the net device structure */ 799 rcu_assign_pointer(ndev->npinfo, npinfo); 800 801 return 0; 802 803 free_npinfo: 804 kfree(npinfo); 805 out: 806 return err; 807 } 808 EXPORT_SYMBOL_GPL(__netpoll_setup); 809 810 int netpoll_setup(struct netpoll *np) 811 { 812 struct net_device *ndev = NULL; 813 struct in_device *in_dev; 814 int err; 815 816 if (np->dev_name) 817 ndev = dev_get_by_name(&init_net, np->dev_name); 818 if (!ndev) { 819 np_err(np, "%s doesn't exist, aborting\n", np->dev_name); 820 return -ENODEV; 821 } 822 823 if (ndev->master) { 824 np_err(np, "%s is a slave device, aborting\n", np->dev_name); 825 err = -EBUSY; 826 goto put; 827 } 828 829 if (!netif_running(ndev)) { 830 unsigned long atmost, atleast; 831 832 np_info(np, "device %s not up yet, forcing it\n", np->dev_name); 833 834 rtnl_lock(); 835 err = dev_open(ndev); 836 rtnl_unlock(); 837 838 if (err) { 839 np_err(np, "failed to open %s\n", ndev->name); 840 goto put; 841 } 842 843 atleast = jiffies + HZ/10; 844 atmost = jiffies + carrier_timeout * HZ; 845 while (!netif_carrier_ok(ndev)) { 846 if (time_after(jiffies, atmost)) { 847 np_notice(np, "timeout waiting for carrier\n"); 848 break; 849 } 850 msleep(1); 851 } 852 853 /* If carrier appears to come up instantly, we don't 854 * trust it and pause so that we don't pump all our 855 * queued console messages into the bitbucket. 856 */ 857 858 if (time_before(jiffies, atleast)) { 859 np_notice(np, "carrier detect appears untrustworthy, waiting 4 seconds\n"); 860 msleep(4000); 861 } 862 } 863 864 if (!np->local_ip) { 865 rcu_read_lock(); 866 in_dev = __in_dev_get_rcu(ndev); 867 868 if (!in_dev || !in_dev->ifa_list) { 869 rcu_read_unlock(); 870 np_err(np, "no IP address for %s, aborting\n", 871 np->dev_name); 872 err = -EDESTADDRREQ; 873 goto put; 874 } 875 876 np->local_ip = in_dev->ifa_list->ifa_local; 877 rcu_read_unlock(); 878 np_info(np, "local IP %pI4\n", &np->local_ip); 879 } 880 881 /* fill up the skb queue */ 882 refill_skbs(); 883 884 rtnl_lock(); 885 err = __netpoll_setup(np, ndev, GFP_KERNEL); 886 rtnl_unlock(); 887 888 if (err) 889 goto put; 890 891 return 0; 892 893 put: 894 dev_put(ndev); 895 return err; 896 } 897 EXPORT_SYMBOL(netpoll_setup); 898 899 static int __init netpoll_init(void) 900 { 901 skb_queue_head_init(&skb_pool); 902 return 0; 903 } 904 core_initcall(netpoll_init); 905 906 static void rcu_cleanup_netpoll_info(struct rcu_head *rcu_head) 907 { 908 struct netpoll_info *npinfo = 909 container_of(rcu_head, struct netpoll_info, rcu); 910 911 skb_queue_purge(&npinfo->arp_tx); 912 skb_queue_purge(&npinfo->txq); 913 914 /* we can't call cancel_delayed_work_sync here, as we are in softirq */ 915 cancel_delayed_work(&npinfo->tx_work); 916 917 /* clean after last, unfinished work */ 918 __skb_queue_purge(&npinfo->txq); 919 /* now cancel it again */ 920 cancel_delayed_work(&npinfo->tx_work); 921 kfree(npinfo); 922 } 923 924 void __netpoll_cleanup(struct netpoll *np) 925 { 926 struct netpoll_info *npinfo; 927 unsigned long flags; 928 929 npinfo = np->dev->npinfo; 930 if (!npinfo) 931 return; 932 933 if (!list_empty(&npinfo->rx_np)) { 934 spin_lock_irqsave(&npinfo->rx_lock, flags); 935 list_del(&np->rx); 936 if (list_empty(&npinfo->rx_np)) 937 npinfo->rx_flags &= ~NETPOLL_RX_ENABLED; 938 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 939 } 940 941 if (atomic_dec_and_test(&npinfo->refcnt)) { 942 const struct net_device_ops *ops; 943 944 ops = np->dev->netdev_ops; 945 if (ops->ndo_netpoll_cleanup) 946 ops->ndo_netpoll_cleanup(np->dev); 947 948 RCU_INIT_POINTER(np->dev->npinfo, NULL); 949 call_rcu_bh(&npinfo->rcu, rcu_cleanup_netpoll_info); 950 } 951 } 952 EXPORT_SYMBOL_GPL(__netpoll_cleanup); 953 954 static void rcu_cleanup_netpoll(struct rcu_head *rcu_head) 955 { 956 struct netpoll *np = container_of(rcu_head, struct netpoll, rcu); 957 958 __netpoll_cleanup(np); 959 kfree(np); 960 } 961 962 void __netpoll_free_rcu(struct netpoll *np) 963 { 964 call_rcu_bh(&np->rcu, rcu_cleanup_netpoll); 965 } 966 EXPORT_SYMBOL_GPL(__netpoll_free_rcu); 967 968 void netpoll_cleanup(struct netpoll *np) 969 { 970 if (!np->dev) 971 return; 972 973 rtnl_lock(); 974 __netpoll_cleanup(np); 975 rtnl_unlock(); 976 977 dev_put(np->dev); 978 np->dev = NULL; 979 } 980 EXPORT_SYMBOL(netpoll_cleanup); 981 982 int netpoll_trap(void) 983 { 984 return atomic_read(&trapped); 985 } 986 EXPORT_SYMBOL(netpoll_trap); 987 988 void netpoll_set_trap(int trap) 989 { 990 if (trap) 991 atomic_inc(&trapped); 992 else 993 atomic_dec(&trapped); 994 } 995 EXPORT_SYMBOL(netpoll_set_trap); 996