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_pick_tx(dev, 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 static atomic_t ip_ident; 384 385 udp_len = len + sizeof(*udph); 386 ip_len = udp_len + sizeof(*iph); 387 total_len = ip_len + LL_RESERVED_SPACE(np->dev); 388 389 skb = find_skb(np, total_len + np->dev->needed_tailroom, 390 total_len - len); 391 if (!skb) 392 return; 393 394 skb_copy_to_linear_data(skb, msg, len); 395 skb_put(skb, len); 396 397 skb_push(skb, sizeof(*udph)); 398 skb_reset_transport_header(skb); 399 udph = udp_hdr(skb); 400 udph->source = htons(np->local_port); 401 udph->dest = htons(np->remote_port); 402 udph->len = htons(udp_len); 403 udph->check = 0; 404 udph->check = csum_tcpudp_magic(np->local_ip, 405 np->remote_ip, 406 udp_len, IPPROTO_UDP, 407 csum_partial(udph, udp_len, 0)); 408 if (udph->check == 0) 409 udph->check = CSUM_MANGLED_0; 410 411 skb_push(skb, sizeof(*iph)); 412 skb_reset_network_header(skb); 413 iph = ip_hdr(skb); 414 415 /* iph->version = 4; iph->ihl = 5; */ 416 put_unaligned(0x45, (unsigned char *)iph); 417 iph->tos = 0; 418 put_unaligned(htons(ip_len), &(iph->tot_len)); 419 iph->id = htons(atomic_inc_return(&ip_ident)); 420 iph->frag_off = 0; 421 iph->ttl = 64; 422 iph->protocol = IPPROTO_UDP; 423 iph->check = 0; 424 put_unaligned(np->local_ip, &(iph->saddr)); 425 put_unaligned(np->remote_ip, &(iph->daddr)); 426 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); 427 428 eth = (struct ethhdr *) skb_push(skb, ETH_HLEN); 429 skb_reset_mac_header(skb); 430 skb->protocol = eth->h_proto = htons(ETH_P_IP); 431 memcpy(eth->h_source, np->dev->dev_addr, ETH_ALEN); 432 memcpy(eth->h_dest, np->remote_mac, ETH_ALEN); 433 434 skb->dev = np->dev; 435 436 netpoll_send_skb(np, skb); 437 } 438 EXPORT_SYMBOL(netpoll_send_udp); 439 440 static void netpoll_arp_reply(struct sk_buff *skb, struct netpoll_info *npinfo) 441 { 442 struct arphdr *arp; 443 unsigned char *arp_ptr; 444 int size, type = ARPOP_REPLY, ptype = ETH_P_ARP; 445 __be32 sip, tip; 446 unsigned char *sha; 447 struct sk_buff *send_skb; 448 struct netpoll *np, *tmp; 449 unsigned long flags; 450 int hlen, tlen; 451 int hits = 0; 452 453 if (list_empty(&npinfo->rx_np)) 454 return; 455 456 /* Before checking the packet, we do some early 457 inspection whether this is interesting at all */ 458 spin_lock_irqsave(&npinfo->rx_lock, flags); 459 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) { 460 if (np->dev == skb->dev) 461 hits++; 462 } 463 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 464 465 /* No netpoll struct is using this dev */ 466 if (!hits) 467 return; 468 469 /* No arp on this interface */ 470 if (skb->dev->flags & IFF_NOARP) 471 return; 472 473 if (!pskb_may_pull(skb, arp_hdr_len(skb->dev))) 474 return; 475 476 skb_reset_network_header(skb); 477 skb_reset_transport_header(skb); 478 arp = arp_hdr(skb); 479 480 if ((arp->ar_hrd != htons(ARPHRD_ETHER) && 481 arp->ar_hrd != htons(ARPHRD_IEEE802)) || 482 arp->ar_pro != htons(ETH_P_IP) || 483 arp->ar_op != htons(ARPOP_REQUEST)) 484 return; 485 486 arp_ptr = (unsigned char *)(arp+1); 487 /* save the location of the src hw addr */ 488 sha = arp_ptr; 489 arp_ptr += skb->dev->addr_len; 490 memcpy(&sip, arp_ptr, 4); 491 arp_ptr += 4; 492 /* If we actually cared about dst hw addr, 493 it would get copied here */ 494 arp_ptr += skb->dev->addr_len; 495 memcpy(&tip, arp_ptr, 4); 496 497 /* Should we ignore arp? */ 498 if (ipv4_is_loopback(tip) || ipv4_is_multicast(tip)) 499 return; 500 501 size = arp_hdr_len(skb->dev); 502 503 spin_lock_irqsave(&npinfo->rx_lock, flags); 504 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) { 505 if (tip != np->local_ip) 506 continue; 507 508 hlen = LL_RESERVED_SPACE(np->dev); 509 tlen = np->dev->needed_tailroom; 510 send_skb = find_skb(np, size + hlen + tlen, hlen); 511 if (!send_skb) 512 continue; 513 514 skb_reset_network_header(send_skb); 515 arp = (struct arphdr *) skb_put(send_skb, size); 516 send_skb->dev = skb->dev; 517 send_skb->protocol = htons(ETH_P_ARP); 518 519 /* Fill the device header for the ARP frame */ 520 if (dev_hard_header(send_skb, skb->dev, ptype, 521 sha, np->dev->dev_addr, 522 send_skb->len) < 0) { 523 kfree_skb(send_skb); 524 continue; 525 } 526 527 /* 528 * Fill out the arp protocol part. 529 * 530 * we only support ethernet device type, 531 * which (according to RFC 1390) should 532 * always equal 1 (Ethernet). 533 */ 534 535 arp->ar_hrd = htons(np->dev->type); 536 arp->ar_pro = htons(ETH_P_IP); 537 arp->ar_hln = np->dev->addr_len; 538 arp->ar_pln = 4; 539 arp->ar_op = htons(type); 540 541 arp_ptr = (unsigned char *)(arp + 1); 542 memcpy(arp_ptr, np->dev->dev_addr, np->dev->addr_len); 543 arp_ptr += np->dev->addr_len; 544 memcpy(arp_ptr, &tip, 4); 545 arp_ptr += 4; 546 memcpy(arp_ptr, sha, np->dev->addr_len); 547 arp_ptr += np->dev->addr_len; 548 memcpy(arp_ptr, &sip, 4); 549 550 netpoll_send_skb(np, send_skb); 551 552 /* If there are several rx_hooks for the same address, 553 we're fine by sending a single reply */ 554 break; 555 } 556 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 557 } 558 559 int __netpoll_rx(struct sk_buff *skb, struct netpoll_info *npinfo) 560 { 561 int proto, len, ulen; 562 int hits = 0; 563 const struct iphdr *iph; 564 struct udphdr *uh; 565 struct netpoll *np, *tmp; 566 567 if (list_empty(&npinfo->rx_np)) 568 goto out; 569 570 if (skb->dev->type != ARPHRD_ETHER) 571 goto out; 572 573 /* check if netpoll clients need ARP */ 574 if (skb->protocol == htons(ETH_P_ARP) && 575 atomic_read(&trapped)) { 576 skb_queue_tail(&npinfo->arp_tx, skb); 577 return 1; 578 } 579 580 if (skb->protocol == cpu_to_be16(ETH_P_8021Q)) { 581 skb = vlan_untag(skb); 582 if (unlikely(!skb)) 583 goto out; 584 } 585 586 proto = ntohs(eth_hdr(skb)->h_proto); 587 if (proto != ETH_P_IP) 588 goto out; 589 if (skb->pkt_type == PACKET_OTHERHOST) 590 goto out; 591 if (skb_shared(skb)) 592 goto out; 593 594 if (!pskb_may_pull(skb, sizeof(struct iphdr))) 595 goto out; 596 iph = (struct iphdr *)skb->data; 597 if (iph->ihl < 5 || iph->version != 4) 598 goto out; 599 if (!pskb_may_pull(skb, iph->ihl*4)) 600 goto out; 601 iph = (struct iphdr *)skb->data; 602 if (ip_fast_csum((u8 *)iph, iph->ihl) != 0) 603 goto out; 604 605 len = ntohs(iph->tot_len); 606 if (skb->len < len || len < iph->ihl*4) 607 goto out; 608 609 /* 610 * Our transport medium may have padded the buffer out. 611 * Now We trim to the true length of the frame. 612 */ 613 if (pskb_trim_rcsum(skb, len)) 614 goto out; 615 616 iph = (struct iphdr *)skb->data; 617 if (iph->protocol != IPPROTO_UDP) 618 goto out; 619 620 len -= iph->ihl*4; 621 uh = (struct udphdr *)(((char *)iph) + iph->ihl*4); 622 ulen = ntohs(uh->len); 623 624 if (ulen != len) 625 goto out; 626 if (checksum_udp(skb, uh, ulen, iph->saddr, iph->daddr)) 627 goto out; 628 629 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) { 630 if (np->local_ip && np->local_ip != iph->daddr) 631 continue; 632 if (np->remote_ip && np->remote_ip != iph->saddr) 633 continue; 634 if (np->local_port && np->local_port != ntohs(uh->dest)) 635 continue; 636 637 np->rx_hook(np, ntohs(uh->source), 638 (char *)(uh+1), 639 ulen - sizeof(struct udphdr)); 640 hits++; 641 } 642 643 if (!hits) 644 goto out; 645 646 kfree_skb(skb); 647 return 1; 648 649 out: 650 if (atomic_read(&trapped)) { 651 kfree_skb(skb); 652 return 1; 653 } 654 655 return 0; 656 } 657 658 void netpoll_print_options(struct netpoll *np) 659 { 660 np_info(np, "local port %d\n", np->local_port); 661 np_info(np, "local IP %pI4\n", &np->local_ip); 662 np_info(np, "interface '%s'\n", np->dev_name); 663 np_info(np, "remote port %d\n", np->remote_port); 664 np_info(np, "remote IP %pI4\n", &np->remote_ip); 665 np_info(np, "remote ethernet address %pM\n", np->remote_mac); 666 } 667 EXPORT_SYMBOL(netpoll_print_options); 668 669 int netpoll_parse_options(struct netpoll *np, char *opt) 670 { 671 char *cur=opt, *delim; 672 673 if (*cur != '@') { 674 if ((delim = strchr(cur, '@')) == NULL) 675 goto parse_failed; 676 *delim = 0; 677 if (kstrtou16(cur, 10, &np->local_port)) 678 goto parse_failed; 679 cur = delim; 680 } 681 cur++; 682 683 if (*cur != '/') { 684 if ((delim = strchr(cur, '/')) == NULL) 685 goto parse_failed; 686 *delim = 0; 687 np->local_ip = in_aton(cur); 688 cur = delim; 689 } 690 cur++; 691 692 if (*cur != ',') { 693 /* parse out dev name */ 694 if ((delim = strchr(cur, ',')) == NULL) 695 goto parse_failed; 696 *delim = 0; 697 strlcpy(np->dev_name, cur, sizeof(np->dev_name)); 698 cur = delim; 699 } 700 cur++; 701 702 if (*cur != '@') { 703 /* dst port */ 704 if ((delim = strchr(cur, '@')) == NULL) 705 goto parse_failed; 706 *delim = 0; 707 if (*cur == ' ' || *cur == '\t') 708 np_info(np, "warning: whitespace is not allowed\n"); 709 if (kstrtou16(cur, 10, &np->remote_port)) 710 goto parse_failed; 711 cur = delim; 712 } 713 cur++; 714 715 /* dst ip */ 716 if ((delim = strchr(cur, '/')) == NULL) 717 goto parse_failed; 718 *delim = 0; 719 np->remote_ip = in_aton(cur); 720 cur = delim + 1; 721 722 if (*cur != 0) { 723 /* MAC address */ 724 if (!mac_pton(cur, np->remote_mac)) 725 goto parse_failed; 726 } 727 728 netpoll_print_options(np); 729 730 return 0; 731 732 parse_failed: 733 np_info(np, "couldn't parse config at '%s'!\n", cur); 734 return -1; 735 } 736 EXPORT_SYMBOL(netpoll_parse_options); 737 738 int __netpoll_setup(struct netpoll *np, struct net_device *ndev, gfp_t gfp) 739 { 740 struct netpoll_info *npinfo; 741 const struct net_device_ops *ops; 742 unsigned long flags; 743 int err; 744 745 np->dev = ndev; 746 strlcpy(np->dev_name, ndev->name, IFNAMSIZ); 747 748 if ((ndev->priv_flags & IFF_DISABLE_NETPOLL) || 749 !ndev->netdev_ops->ndo_poll_controller) { 750 np_err(np, "%s doesn't support polling, aborting\n", 751 np->dev_name); 752 err = -ENOTSUPP; 753 goto out; 754 } 755 756 if (!ndev->npinfo) { 757 npinfo = kmalloc(sizeof(*npinfo), gfp); 758 if (!npinfo) { 759 err = -ENOMEM; 760 goto out; 761 } 762 763 npinfo->rx_flags = 0; 764 INIT_LIST_HEAD(&npinfo->rx_np); 765 766 spin_lock_init(&npinfo->rx_lock); 767 skb_queue_head_init(&npinfo->arp_tx); 768 skb_queue_head_init(&npinfo->txq); 769 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process); 770 771 atomic_set(&npinfo->refcnt, 1); 772 773 ops = np->dev->netdev_ops; 774 if (ops->ndo_netpoll_setup) { 775 err = ops->ndo_netpoll_setup(ndev, npinfo, gfp); 776 if (err) 777 goto free_npinfo; 778 } 779 } else { 780 npinfo = ndev->npinfo; 781 atomic_inc(&npinfo->refcnt); 782 } 783 784 npinfo->netpoll = np; 785 786 if (np->rx_hook) { 787 spin_lock_irqsave(&npinfo->rx_lock, flags); 788 npinfo->rx_flags |= NETPOLL_RX_ENABLED; 789 list_add_tail(&np->rx, &npinfo->rx_np); 790 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 791 } 792 793 /* last thing to do is link it to the net device structure */ 794 rcu_assign_pointer(ndev->npinfo, npinfo); 795 796 return 0; 797 798 free_npinfo: 799 kfree(npinfo); 800 out: 801 return err; 802 } 803 EXPORT_SYMBOL_GPL(__netpoll_setup); 804 805 int netpoll_setup(struct netpoll *np) 806 { 807 struct net_device *ndev = NULL; 808 struct in_device *in_dev; 809 int err; 810 811 if (np->dev_name) 812 ndev = dev_get_by_name(&init_net, np->dev_name); 813 if (!ndev) { 814 np_err(np, "%s doesn't exist, aborting\n", np->dev_name); 815 return -ENODEV; 816 } 817 818 if (ndev->master) { 819 np_err(np, "%s is a slave device, aborting\n", np->dev_name); 820 err = -EBUSY; 821 goto put; 822 } 823 824 if (!netif_running(ndev)) { 825 unsigned long atmost, atleast; 826 827 np_info(np, "device %s not up yet, forcing it\n", np->dev_name); 828 829 rtnl_lock(); 830 err = dev_open(ndev); 831 rtnl_unlock(); 832 833 if (err) { 834 np_err(np, "failed to open %s\n", ndev->name); 835 goto put; 836 } 837 838 atleast = jiffies + HZ/10; 839 atmost = jiffies + carrier_timeout * HZ; 840 while (!netif_carrier_ok(ndev)) { 841 if (time_after(jiffies, atmost)) { 842 np_notice(np, "timeout waiting for carrier\n"); 843 break; 844 } 845 msleep(1); 846 } 847 848 /* If carrier appears to come up instantly, we don't 849 * trust it and pause so that we don't pump all our 850 * queued console messages into the bitbucket. 851 */ 852 853 if (time_before(jiffies, atleast)) { 854 np_notice(np, "carrier detect appears untrustworthy, waiting 4 seconds\n"); 855 msleep(4000); 856 } 857 } 858 859 if (!np->local_ip) { 860 rcu_read_lock(); 861 in_dev = __in_dev_get_rcu(ndev); 862 863 if (!in_dev || !in_dev->ifa_list) { 864 rcu_read_unlock(); 865 np_err(np, "no IP address for %s, aborting\n", 866 np->dev_name); 867 err = -EDESTADDRREQ; 868 goto put; 869 } 870 871 np->local_ip = in_dev->ifa_list->ifa_local; 872 rcu_read_unlock(); 873 np_info(np, "local IP %pI4\n", &np->local_ip); 874 } 875 876 /* fill up the skb queue */ 877 refill_skbs(); 878 879 rtnl_lock(); 880 err = __netpoll_setup(np, ndev, GFP_KERNEL); 881 rtnl_unlock(); 882 883 if (err) 884 goto put; 885 886 return 0; 887 888 put: 889 dev_put(ndev); 890 return err; 891 } 892 EXPORT_SYMBOL(netpoll_setup); 893 894 static int __init netpoll_init(void) 895 { 896 skb_queue_head_init(&skb_pool); 897 return 0; 898 } 899 core_initcall(netpoll_init); 900 901 static void rcu_cleanup_netpoll_info(struct rcu_head *rcu_head) 902 { 903 struct netpoll_info *npinfo = 904 container_of(rcu_head, struct netpoll_info, rcu); 905 906 skb_queue_purge(&npinfo->arp_tx); 907 skb_queue_purge(&npinfo->txq); 908 909 /* we can't call cancel_delayed_work_sync here, as we are in softirq */ 910 cancel_delayed_work(&npinfo->tx_work); 911 912 /* clean after last, unfinished work */ 913 __skb_queue_purge(&npinfo->txq); 914 /* now cancel it again */ 915 cancel_delayed_work(&npinfo->tx_work); 916 kfree(npinfo); 917 } 918 919 void __netpoll_cleanup(struct netpoll *np) 920 { 921 struct netpoll_info *npinfo; 922 unsigned long flags; 923 924 npinfo = np->dev->npinfo; 925 if (!npinfo) 926 return; 927 928 if (!list_empty(&npinfo->rx_np)) { 929 spin_lock_irqsave(&npinfo->rx_lock, flags); 930 list_del(&np->rx); 931 if (list_empty(&npinfo->rx_np)) 932 npinfo->rx_flags &= ~NETPOLL_RX_ENABLED; 933 spin_unlock_irqrestore(&npinfo->rx_lock, flags); 934 } 935 936 if (atomic_dec_and_test(&npinfo->refcnt)) { 937 const struct net_device_ops *ops; 938 939 ops = np->dev->netdev_ops; 940 if (ops->ndo_netpoll_cleanup) 941 ops->ndo_netpoll_cleanup(np->dev); 942 943 RCU_INIT_POINTER(np->dev->npinfo, NULL); 944 call_rcu_bh(&npinfo->rcu, rcu_cleanup_netpoll_info); 945 } 946 } 947 EXPORT_SYMBOL_GPL(__netpoll_cleanup); 948 949 static void rcu_cleanup_netpoll(struct rcu_head *rcu_head) 950 { 951 struct netpoll *np = container_of(rcu_head, struct netpoll, rcu); 952 953 __netpoll_cleanup(np); 954 kfree(np); 955 } 956 957 void __netpoll_free_rcu(struct netpoll *np) 958 { 959 call_rcu_bh(&np->rcu, rcu_cleanup_netpoll); 960 } 961 EXPORT_SYMBOL_GPL(__netpoll_free_rcu); 962 963 void netpoll_cleanup(struct netpoll *np) 964 { 965 if (!np->dev) 966 return; 967 968 rtnl_lock(); 969 __netpoll_cleanup(np); 970 rtnl_unlock(); 971 972 dev_put(np->dev); 973 np->dev = NULL; 974 } 975 EXPORT_SYMBOL(netpoll_cleanup); 976 977 int netpoll_trap(void) 978 { 979 return atomic_read(&trapped); 980 } 981 EXPORT_SYMBOL(netpoll_trap); 982 983 void netpoll_set_trap(int trap) 984 { 985 if (trap) 986 atomic_inc(&trapped); 987 else 988 atomic_dec(&trapped); 989 } 990 EXPORT_SYMBOL(netpoll_set_trap); 991