1 /* 2 * Copyright 2006-2010, Haiku, Inc. All Rights Reserved. 3 * Distributed under the terms of the MIT License. 4 * 5 * Authors: 6 * Axel Dörfler, axeld@pinc-software.de 7 * Hugo Santos, hugosantos@gmail.com 8 */ 9 10 11 //! Ethernet Address Resolution Protocol, see RFC 826. 12 13 14 #include <arp_control.h> 15 #include <net_datalink_protocol.h> 16 #include <net_device.h> 17 #include <net_datalink.h> 18 #include <net_stack.h> 19 #include <NetBufferUtilities.h> 20 21 #include <generic_syscall.h> 22 #include <util/atomic.h> 23 #include <util/AutoLock.h> 24 #include <util/DoublyLinkedList.h> 25 #include <util/khash.h> 26 27 #include <ByteOrder.h> 28 #include <KernelExport.h> 29 30 #include <net/if.h> 31 #include <net/if_dl.h> 32 #include <net/if_types.h> 33 #include <new> 34 #include <stdio.h> 35 #include <string.h> 36 #include <sys/sockio.h> 37 38 39 //#define TRACE_ARP 40 #ifdef TRACE_ARP 41 # define TRACE(x) dprintf x 42 #else 43 # define TRACE(x) ; 44 #endif 45 46 47 struct arp_header { 48 uint16 hardware_type; 49 uint16 protocol_type; 50 uint8 hardware_length; 51 uint8 protocol_length; 52 uint16 opcode; 53 54 // TODO: this should be a variable length header, but for our current 55 // usage (Ethernet/IPv4), this should work fine. 56 uint8 hardware_sender[6]; 57 in_addr_t protocol_sender; 58 uint8 hardware_target[6]; 59 in_addr_t protocol_target; 60 } _PACKED; 61 62 #define ARP_OPCODE_REQUEST 1 63 #define ARP_OPCODE_REPLY 2 64 65 #define ARP_HARDWARE_TYPE_ETHER 1 66 67 struct arp_entry { 68 arp_entry *next; 69 in_addr_t protocol_address; 70 sockaddr_dl hardware_address; 71 uint32 flags; 72 net_buffer *request_buffer; 73 net_timer timer; 74 uint32 timer_state; 75 bigtime_t timestamp; 76 net_datalink_protocol *protocol; 77 78 typedef DoublyLinkedListCLink<net_buffer> NetBufferLink; 79 typedef DoublyLinkedList<net_buffer, NetBufferLink> BufferList; 80 81 BufferList queue; 82 83 static int Compare(void *_entry, const void *_key); 84 static uint32 Hash(void *_entry, const void *_key, uint32 range); 85 static arp_entry *Lookup(in_addr_t protocolAddress); 86 static arp_entry *Add(in_addr_t protocolAddress, 87 sockaddr_dl *hardwareAddress, uint32 flags); 88 89 ~arp_entry(); 90 91 void ClearQueue(); 92 void MarkFailed(); 93 void MarkValid(); 94 void ScheduleRemoval(); 95 }; 96 97 // see arp_control.h for more flags 98 #define ARP_FLAG_REMOVED 0x00010000 99 #define ARP_PUBLIC_FLAG_MASK 0x0000ffff 100 101 #define ARP_NO_STATE 0 102 #define ARP_STATE_REQUEST 1 103 #define ARP_STATE_LAST_REQUEST 5 104 #define ARP_STATE_REQUEST_FAILED 6 105 #define ARP_STATE_REMOVE_FAILED 7 106 #define ARP_STATE_STALE 8 107 108 #define ARP_STALE_TIMEOUT 30 * 60000000LL // 30 minutes 109 #define ARP_REJECT_TIMEOUT 20000000LL // 20 seconds 110 #define ARP_REQUEST_TIMEOUT 1000000LL // 1 second 111 112 struct arp_protocol : net_datalink_protocol { 113 sockaddr_dl hardware_address; 114 in_addr_t local_address; 115 }; 116 117 118 static const net_buffer* kDeletedBuffer = (net_buffer*)~0; 119 120 static void arp_timer(struct net_timer *timer, void *data); 121 122 net_buffer_module_info* gBufferModule; 123 static net_stack_module_info* sStackModule; 124 static net_datalink_module_info* sDatalinkModule; 125 static hash_table* sCache; 126 static mutex sCacheLock; 127 static bool sIgnoreReplies; 128 129 130 #ifdef TRACE_ARP 131 132 133 const char* 134 mac_to_string(uint8* address) 135 { 136 static char buffer[20]; 137 snprintf(buffer, sizeof(buffer), "%02x:%02x:%02x:%02x:%02x:%02x", 138 address[0], address[1], address[2], address[3], address[4], address[5]); 139 return buffer; 140 } 141 142 143 const char* 144 inet_to_string(in_addr_t address) 145 { 146 static char buffer[20]; 147 148 unsigned int hostAddress = ntohl(address); 149 snprintf(buffer, sizeof(buffer), "%d.%d.%d.%d", 150 hostAddress >> 24, (hostAddress >> 16) & 0xff, 151 (hostAddress >> 8) & 0xff, hostAddress & 0xff); 152 return buffer; 153 } 154 155 156 #endif // TRACE_ARP 157 158 159 static net_buffer* 160 get_request_buffer(arp_entry* entry) 161 { 162 net_buffer* buffer = entry->request_buffer; 163 if (buffer == NULL || buffer == kDeletedBuffer) 164 return NULL; 165 166 buffer = atomic_pointer_test_and_set(&entry->request_buffer, 167 (net_buffer*)NULL, buffer); 168 if (buffer == kDeletedBuffer) 169 return NULL; 170 171 return buffer; 172 } 173 174 175 static void 176 put_request_buffer(arp_entry* entry, net_buffer* buffer) 177 { 178 net_buffer* requestBuffer = atomic_pointer_test_and_set( 179 &entry->request_buffer, buffer, (net_buffer*)NULL); 180 if (requestBuffer != NULL) { 181 // someone else took over ownership of the request buffer 182 gBufferModule->free(buffer); 183 } 184 } 185 186 187 static void 188 delete_request_buffer(arp_entry* entry) 189 { 190 net_buffer* buffer = atomic_pointer_set(&entry->request_buffer, 191 kDeletedBuffer); 192 if (buffer != NULL && buffer != kDeletedBuffer) 193 gBufferModule->free(buffer); 194 } 195 196 197 static void 198 ipv4_to_ether_multicast(sockaddr_dl *destination, const sockaddr_in *source) 199 { 200 // RFC 1112 - Host extensions for IP multicasting 201 // 202 // ``An IP host group address is mapped to an Ethernet multicast 203 // address by placing the low-order 23-bits of the IP address into 204 // the low-order 23 bits of the Ethernet multicast address 205 // 01-00-5E-00-00-00 (hex).'' 206 207 destination->sdl_len = sizeof(sockaddr_dl); 208 destination->sdl_family = AF_LINK; 209 destination->sdl_index = 0; 210 destination->sdl_type = IFT_ETHER; 211 destination->sdl_e_type = ETHER_TYPE_IP; 212 destination->sdl_nlen = destination->sdl_slen = 0; 213 destination->sdl_alen = ETHER_ADDRESS_LENGTH; 214 215 memcpy(LLADDR(destination) + 2, &source->sin_addr, sizeof(in_addr)); 216 uint32 *data = (uint32 *)LLADDR(destination); 217 data[0] = (data[0] & htonl(0x7f)) | htonl(0x01005e00); 218 } 219 220 221 // #pragma mark - 222 223 224 /*static*/ int 225 arp_entry::Compare(void *_entry, const void *_key) 226 { 227 arp_entry *entry = (arp_entry *)_entry; 228 in_addr_t *key = (in_addr_t *)_key; 229 230 if (entry->protocol_address == *key) 231 return 0; 232 233 return 1; 234 } 235 236 237 /*static*/ uint32 238 arp_entry::Hash(void *_entry, const void *_key, uint32 range) 239 { 240 arp_entry *entry = (arp_entry *)_entry; 241 const in_addr_t *key = (const in_addr_t *)_key; 242 243 // TODO: check if this makes a good hash... 244 #define HASH(o) ((((o) >> 24) ^ ((o) >> 16) ^ ((o) >> 8) ^ (o)) % range) 245 246 #if 0 247 in_addr_t a = entry ? entry->protocol_address : *key; 248 dprintf("%ld.%ld.%ld.%ld: Hash: %lu\n", a >> 24, (a >> 16) & 0xff, 249 (a >> 8) & 0xff, a & 0xff, HASH(a)); 250 #endif 251 252 if (entry != NULL) 253 return HASH(entry->protocol_address); 254 255 return HASH(*key); 256 #undef HASH 257 } 258 259 260 /*static*/ arp_entry * 261 arp_entry::Lookup(in_addr_t address) 262 { 263 return (arp_entry *)hash_lookup(sCache, &address); 264 } 265 266 267 /*static*/ arp_entry * 268 arp_entry::Add(in_addr_t protocolAddress, sockaddr_dl *hardwareAddress, 269 uint32 flags) 270 { 271 ASSERT_LOCKED_MUTEX(&sCacheLock); 272 273 arp_entry *entry = new (std::nothrow) arp_entry; 274 if (entry == NULL) 275 return NULL; 276 277 entry->protocol_address = protocolAddress; 278 entry->flags = flags; 279 entry->timestamp = system_time(); 280 entry->protocol = NULL; 281 entry->request_buffer = NULL; 282 entry->timer_state = ARP_NO_STATE; 283 sStackModule->init_timer(&entry->timer, arp_timer, entry); 284 285 if (hardwareAddress != NULL) { 286 // this entry is already resolved 287 entry->hardware_address = *hardwareAddress; 288 entry->hardware_address.sdl_e_type = ETHER_TYPE_IP; 289 } else { 290 // this entry still needs to be resolved 291 entry->hardware_address.sdl_alen = 0; 292 } 293 if (entry->hardware_address.sdl_len != sizeof(sockaddr_dl)) { 294 // explicitly set correct length in case our caller hasn't... 295 entry->hardware_address.sdl_len = sizeof(sockaddr_dl); 296 } 297 298 if (hash_insert(sCache, entry) != B_OK) { 299 // We can delete the entry here with the sCacheLock held, since it's 300 // guaranteed there are no timers pending. 301 delete entry; 302 return NULL; 303 } 304 305 return entry; 306 } 307 308 309 arp_entry::~arp_entry() 310 { 311 // make sure there is no active timer left for us 312 sStackModule->cancel_timer(&timer); 313 sStackModule->wait_for_timer(&timer); 314 315 ClearQueue(); 316 } 317 318 319 void 320 arp_entry::ClearQueue() 321 { 322 BufferList::Iterator iterator = queue.GetIterator(); 323 while (iterator.HasNext()) { 324 net_buffer *buffer = iterator.Next(); 325 iterator.Remove(); 326 gBufferModule->free(buffer); 327 } 328 } 329 330 331 void 332 arp_entry::MarkFailed() 333 { 334 TRACE(("ARP entry %p Marked as FAILED\n", this)); 335 336 flags = (flags & ~ARP_FLAG_VALID) | ARP_FLAG_REJECT; 337 ClearQueue(); 338 } 339 340 341 void 342 arp_entry::MarkValid() 343 { 344 TRACE(("ARP entry %p Marked as VALID, have %li packets queued.\n", this, 345 queue.Count())); 346 347 flags = (flags & ~ARP_FLAG_REJECT) | ARP_FLAG_VALID; 348 349 BufferList::Iterator iterator = queue.GetIterator(); 350 while (iterator.HasNext()) { 351 net_buffer *buffer = iterator.Next(); 352 iterator.Remove(); 353 354 TRACE((" ARP Dequeing packet %p...\n", buffer)); 355 356 memcpy(buffer->destination, &hardware_address, 357 hardware_address.sdl_len); 358 protocol->next->module->send_data(protocol->next, buffer); 359 } 360 } 361 362 363 void 364 arp_entry::ScheduleRemoval() 365 { 366 // schedule a timer to remove this entry 367 timer_state = ARP_STATE_REMOVE_FAILED; 368 sStackModule->set_timer(&timer, 0); 369 } 370 371 372 // #pragma mark - 373 374 375 /*! Updates the entry determined by \a protocolAddress with the specified 376 \a hardwareAddress. 377 If such an entry does not exist yet, a new entry is added. If you try 378 to update a local existing entry but didn't ask for it (by setting 379 \a flags to ARP_FLAG_LOCAL), an error is returned. 380 381 This function does not lock the cache - you have to do it yourself 382 before calling it. 383 */ 384 static status_t 385 arp_update_entry(in_addr_t protocolAddress, sockaddr_dl *hardwareAddress, 386 uint32 flags, arp_entry **_entry = NULL) 387 { 388 ASSERT_LOCKED_MUTEX(&sCacheLock); 389 TRACE(("%s(%s, %s, flags 0x%" B_PRIx32 ")\n", __FUNCTION__, 390 inet_to_string(protocolAddress), mac_to_string(LLADDR(hardwareAddress)), 391 flags)); 392 393 arp_entry *entry = arp_entry::Lookup(protocolAddress); 394 if (entry != NULL) { 395 // We disallow updating of entries that had been resolved before, 396 // but to a different address (only for those that belong to a 397 // specific address - redefining INADDR_ANY is always allowed). 398 // Right now, you have to manually purge the ARP entries (or wait some 399 // time) to let us switch to the new address. 400 if (protocolAddress != INADDR_ANY 401 && entry->hardware_address.sdl_alen != 0 402 && memcmp(LLADDR(&entry->hardware_address), 403 LLADDR(hardwareAddress), ETHER_ADDRESS_LENGTH)) { 404 uint8* data = LLADDR(hardwareAddress); 405 dprintf("ARP host %08x updated with different hardware address " 406 "%02x:%02x:%02x:%02x:%02x:%02x.\n", protocolAddress, 407 data[0], data[1], data[2], data[3], data[4], data[5]); 408 return B_ERROR; 409 } 410 411 entry->hardware_address = *hardwareAddress; 412 entry->timestamp = system_time(); 413 } else { 414 entry = arp_entry::Add(protocolAddress, hardwareAddress, flags); 415 if (entry == NULL) 416 return B_NO_MEMORY; 417 } 418 419 delete_request_buffer(entry); 420 421 if ((entry->flags & ARP_FLAG_PERMANENT) == 0) { 422 // (re)start the stale timer 423 entry->timer_state = ARP_STATE_STALE; 424 sStackModule->set_timer(&entry->timer, ARP_STALE_TIMEOUT); 425 } 426 427 if ((entry->flags & ARP_FLAG_REJECT) != 0) 428 entry->MarkFailed(); 429 else 430 entry->MarkValid(); 431 432 if (_entry) 433 *_entry = entry; 434 435 return B_OK; 436 } 437 438 439 static void 440 arp_remove_local_entry(arp_protocol* protocol, const sockaddr* local, 441 bool updateLocalAddress) 442 { 443 in_addr_t inetAddress; 444 445 if (local == NULL) { 446 // interface has not yet been set 447 inetAddress = INADDR_ANY; 448 } else 449 inetAddress = ((sockaddr_in*)local)->sin_addr.s_addr; 450 451 TRACE(("%s(): address %s\n", __FUNCTION__, inet_to_string(inetAddress))); 452 453 MutexLocker locker(sCacheLock); 454 455 arp_entry* entry = arp_entry::Lookup(inetAddress); 456 if (entry != NULL) { 457 hash_remove(sCache, entry); 458 entry->flags |= ARP_FLAG_REMOVED; 459 } 460 461 if (updateLocalAddress && protocol->local_address == inetAddress) { 462 // find new local sender address 463 protocol->local_address = 0; 464 465 net_interface_address* address = NULL; 466 while (sDatalinkModule->get_next_interface_address(protocol->interface, 467 &address)) { 468 if (address->local == NULL || address->local->sa_family != AF_INET) 469 continue; 470 471 protocol->local_address 472 = ((sockaddr_in*)address->local)->sin_addr.s_addr; 473 } 474 } 475 476 locker.Unlock(); 477 delete entry; 478 } 479 480 481 /*! Removes all entries belonging to the local interface of the \a procotol 482 given. 483 */ 484 static void 485 arp_remove_local(arp_protocol* protocol) 486 { 487 net_interface_address* address = NULL; 488 while (sDatalinkModule->get_next_interface_address(protocol->interface, 489 &address)) { 490 if (address->local == NULL || address->local->sa_family != AF_INET) 491 continue; 492 493 arp_remove_local_entry(protocol, address->local, false); 494 } 495 } 496 497 498 static status_t 499 arp_set_local_entry(arp_protocol* protocol, const sockaddr* local) 500 { 501 MutexLocker locker(sCacheLock); 502 503 net_interface* interface = protocol->interface; 504 in_addr_t inetAddress; 505 506 if (local == NULL) { 507 // interface has not yet been set 508 inetAddress = INADDR_ANY; 509 } else 510 inetAddress = ((sockaddr_in*)local)->sin_addr.s_addr; 511 512 TRACE(("%s(): address %s\n", __FUNCTION__, inet_to_string(inetAddress))); 513 514 if (protocol->local_address == 0) 515 protocol->local_address = inetAddress; 516 517 sockaddr_dl address; 518 address.sdl_len = sizeof(sockaddr_dl); 519 address.sdl_family = AF_LINK; 520 address.sdl_type = IFT_ETHER; 521 address.sdl_e_type = ETHER_TYPE_IP; 522 address.sdl_nlen = 0; 523 address.sdl_slen = 0; 524 address.sdl_alen = interface->device->address.length; 525 memcpy(LLADDR(&address), interface->device->address.data, address.sdl_alen); 526 527 memcpy(&protocol->hardware_address, &address, sizeof(sockaddr_dl)); 528 // cache the address in our protocol 529 530 arp_entry* entry; 531 status_t status = arp_update_entry(inetAddress, &address, 532 ARP_FLAG_LOCAL | ARP_FLAG_PERMANENT, &entry); 533 if (status == B_OK) 534 entry->protocol = protocol; 535 536 return status; 537 } 538 539 540 /*! Creates permanent local entries for all addresses of the interface belonging 541 to this protocol. 542 Returns an error if no entry could be added. 543 */ 544 static status_t 545 arp_update_local(arp_protocol* protocol) 546 { 547 protocol->local_address = 0; 548 // TODO: test if this actually works - maybe we should use 549 // INADDR_BROADCAST instead 550 551 ssize_t count = 0; 552 553 net_interface_address* address = NULL; 554 while (sDatalinkModule->get_next_interface_address(protocol->interface, 555 &address)) { 556 if (address->local == NULL || address->local->sa_family != AF_INET) 557 continue; 558 559 if (arp_set_local_entry(protocol, address->local) == B_OK) { 560 count++; 561 } 562 } 563 564 if (count == 0) 565 return arp_set_local_entry(protocol, NULL); 566 567 return B_OK; 568 } 569 570 571 static status_t 572 handle_arp_request(net_buffer *buffer, arp_header &header) 573 { 574 MutexLocker locker(sCacheLock); 575 576 if (!sIgnoreReplies) { 577 arp_update_entry(header.protocol_sender, 578 (sockaddr_dl *)buffer->source, 0); 579 // remember the address of the sender as we might need it later 580 } 581 582 // check if this request is for us 583 584 arp_entry *entry = arp_entry::Lookup(header.protocol_target); 585 if (entry == NULL || entry->protocol == NULL 586 || (entry->flags & (ARP_FLAG_LOCAL | ARP_FLAG_PUBLISH)) == 0) { 587 // We're not the one to answer this request 588 // TODO: instead of letting the other's request time-out, can we reply 589 // failure somehow? 590 TRACE((" not for us\n")); 591 return B_ERROR; 592 } 593 594 // send a reply (by reusing the buffer we got) 595 596 TRACE((" send reply!\n")); 597 header.opcode = htons(ARP_OPCODE_REPLY); 598 599 memcpy(header.hardware_target, header.hardware_sender, ETHER_ADDRESS_LENGTH); 600 header.protocol_target = header.protocol_sender; 601 memcpy(header.hardware_sender, LLADDR(&entry->hardware_address), 602 ETHER_ADDRESS_LENGTH); 603 header.protocol_sender = entry->protocol_address; 604 605 // exchange source and destination address 606 memcpy(LLADDR((sockaddr_dl *)buffer->source), header.hardware_sender, 607 ETHER_ADDRESS_LENGTH); 608 memcpy(LLADDR((sockaddr_dl *)buffer->destination), header.hardware_target, 609 ETHER_ADDRESS_LENGTH); 610 611 buffer->flags = 0; 612 // make sure this won't be a broadcast message 613 614 return entry->protocol->next->module->send_data(entry->protocol->next, 615 buffer); 616 } 617 618 619 static void 620 handle_arp_reply(net_buffer *buffer, arp_header &header) 621 { 622 if (sIgnoreReplies) 623 return; 624 625 MutexLocker locker(sCacheLock); 626 arp_update_entry(header.protocol_sender, (sockaddr_dl *)buffer->source, 0); 627 } 628 629 630 static status_t 631 arp_receive(void *cookie, net_device *device, net_buffer *buffer) 632 { 633 TRACE(("ARP receive\n")); 634 635 NetBufferHeaderReader<arp_header> bufferHeader(buffer); 636 if (bufferHeader.Status() < B_OK) 637 return bufferHeader.Status(); 638 639 arp_header &header = bufferHeader.Data(); 640 uint16 opcode = ntohs(header.opcode); 641 642 #ifdef TRACE_ARP 643 dprintf(" hw sender: %s\n", mac_to_string(header.hardware_sender)); 644 dprintf(" proto sender: %s\n", inet_to_string(header.protocol_sender)); 645 dprintf(" hw target: %s\n", mac_to_string(header.hardware_target));; 646 dprintf(" proto target: %s\n", inet_to_string(header.protocol_target)); 647 #endif // TRACE_ARP 648 649 if (ntohs(header.protocol_type) != ETHER_TYPE_IP 650 || ntohs(header.hardware_type) != ARP_HARDWARE_TYPE_ETHER) 651 return B_BAD_TYPE; 652 653 // check if the packet is okay 654 655 if (header.hardware_length != ETHER_ADDRESS_LENGTH 656 || header.protocol_length != sizeof(in_addr_t)) 657 return B_BAD_DATA; 658 659 // handle packet 660 661 switch (opcode) { 662 case ARP_OPCODE_REQUEST: 663 TRACE((" got ARP request\n")); 664 if (handle_arp_request(buffer, header) == B_OK) { 665 // the function will take care of the buffer if everything 666 // went well 667 return B_OK; 668 } 669 break; 670 case ARP_OPCODE_REPLY: 671 TRACE((" got ARP reply\n")); 672 handle_arp_reply(buffer, header); 673 break; 674 675 default: 676 dprintf("unknown ARP opcode %d\n", opcode); 677 return B_ERROR; 678 } 679 680 gBufferModule->free(buffer); 681 return B_OK; 682 } 683 684 685 static void 686 arp_timer(struct net_timer *timer, void *data) 687 { 688 arp_entry *entry = (arp_entry *)data; 689 TRACE(("ARP timer %ld, entry %p!\n", entry->timer_state, entry)); 690 691 switch (entry->timer_state) { 692 case ARP_NO_STATE: 693 // who are you kidding? 694 break; 695 696 case ARP_STATE_REQUEST_FAILED: 697 // Requesting the ARP entry failed, we keep it around for a while, 698 // though, so that we won't try to request the same address again 699 // too soon. 700 TRACE((" requesting ARP entry %p failed!\n", entry)); 701 entry->timer_state = ARP_STATE_REMOVE_FAILED; 702 entry->MarkFailed(); 703 sStackModule->set_timer(&entry->timer, ARP_REJECT_TIMEOUT); 704 break; 705 706 case ARP_STATE_REMOVE_FAILED: 707 case ARP_STATE_STALE: 708 { 709 // the entry has aged so much that we're going to remove it 710 TRACE((" remove ARP entry %p!\n", entry)); 711 712 MutexLocker locker(sCacheLock); 713 if ((entry->flags & ARP_FLAG_REMOVED) != 0) { 714 // The entry has already been removed, and is about to be 715 // deleted 716 break; 717 } 718 719 hash_remove(sCache, entry); 720 locker.Unlock(); 721 722 delete entry; 723 break; 724 } 725 726 default: 727 { 728 if (entry->timer_state > ARP_STATE_LAST_REQUEST 729 || entry->protocol == NULL) 730 break; 731 732 TRACE((" send request for ARP entry %p!\n", entry)); 733 734 net_buffer *request = get_request_buffer(entry); 735 if (request == NULL) 736 break; 737 738 if (entry->timer_state < ARP_STATE_LAST_REQUEST) { 739 // we'll still need our buffer, so in order to prevent it being 740 // freed by a successful send, we need to clone it 741 net_buffer* clone = gBufferModule->clone(request, true); 742 if (clone == NULL) { 743 // cloning failed - that means we won't be able to send as 744 // many requests as originally planned 745 entry->timer_state = ARP_STATE_LAST_REQUEST; 746 } else { 747 put_request_buffer(entry, request); 748 request = clone; 749 } 750 } 751 752 // we're trying to resolve the address, so keep sending requests 753 status_t status = entry->protocol->next->module->send_data( 754 entry->protocol->next, request); 755 if (status < B_OK) 756 gBufferModule->free(request); 757 758 entry->timer_state++; 759 sStackModule->set_timer(&entry->timer, ARP_REQUEST_TIMEOUT); 760 break; 761 } 762 } 763 } 764 765 766 /*! Address resolver function: prepares and triggers the ARP request necessary 767 to retrieve the hardware address for \a address. 768 769 You need to have the sCacheLock held when calling this function. 770 */ 771 static status_t 772 arp_start_resolve(arp_protocol* protocol, in_addr_t address, arp_entry** _entry) 773 { 774 ASSERT_LOCKED_MUTEX(&sCacheLock); 775 776 // create an unresolved ARP entry as a placeholder 777 arp_entry *entry = arp_entry::Add(address, NULL, 0); 778 if (entry == NULL) 779 return B_NO_MEMORY; 780 781 // prepare ARP request 782 783 entry->request_buffer = gBufferModule->create(256); 784 if (entry->request_buffer == NULL) { 785 entry->ScheduleRemoval(); 786 return B_NO_MEMORY; 787 } 788 789 NetBufferPrepend<arp_header> bufferHeader(entry->request_buffer); 790 status_t status = bufferHeader.Status(); 791 if (status < B_OK) { 792 entry->ScheduleRemoval(); 793 return status; 794 } 795 796 // prepare ARP header 797 798 net_device *device = protocol->interface->device; 799 arp_header &header = bufferHeader.Data(); 800 801 header.hardware_type = htons(ARP_HARDWARE_TYPE_ETHER); 802 header.protocol_type = htons(ETHER_TYPE_IP); 803 header.hardware_length = ETHER_ADDRESS_LENGTH; 804 header.protocol_length = sizeof(in_addr_t); 805 header.opcode = htons(ARP_OPCODE_REQUEST); 806 807 memcpy(header.hardware_sender, device->address.data, ETHER_ADDRESS_LENGTH); 808 memset(header.hardware_target, 0, ETHER_ADDRESS_LENGTH); 809 header.protocol_sender = protocol->local_address; 810 header.protocol_target = address; 811 812 // prepare source and target addresses 813 814 struct sockaddr_dl &source = *(struct sockaddr_dl *) 815 entry->request_buffer->source; 816 source.sdl_len = sizeof(sockaddr_dl); 817 source.sdl_family = AF_LINK; 818 source.sdl_index = device->index; 819 source.sdl_type = IFT_ETHER; 820 source.sdl_e_type = ETHER_TYPE_ARP; 821 source.sdl_nlen = source.sdl_slen = 0; 822 source.sdl_alen = ETHER_ADDRESS_LENGTH; 823 memcpy(source.sdl_data, device->address.data, ETHER_ADDRESS_LENGTH); 824 825 entry->request_buffer->flags = MSG_BCAST; 826 // this is a broadcast packet, we don't need to fill in the destination 827 828 entry->protocol = protocol; 829 entry->timer_state = ARP_STATE_REQUEST; 830 sStackModule->set_timer(&entry->timer, 0); 831 // start request timer 832 833 *_entry = entry; 834 return B_OK; 835 } 836 837 838 static status_t 839 arp_control(const char *subsystem, uint32 function, void *buffer, 840 size_t bufferSize) 841 { 842 struct arp_control control; 843 if (bufferSize != sizeof(struct arp_control)) 844 return B_BAD_VALUE; 845 if (user_memcpy(&control, buffer, sizeof(struct arp_control)) < B_OK) 846 return B_BAD_ADDRESS; 847 848 MutexLocker locker(sCacheLock); 849 850 switch (function) { 851 case ARP_SET_ENTRY: 852 { 853 sockaddr_dl hardwareAddress; 854 855 hardwareAddress.sdl_len = sizeof(sockaddr_dl); 856 hardwareAddress.sdl_family = AF_LINK; 857 hardwareAddress.sdl_index = 0; 858 hardwareAddress.sdl_type = IFT_ETHER; 859 hardwareAddress.sdl_e_type = ETHER_TYPE_IP; 860 hardwareAddress.sdl_nlen = hardwareAddress.sdl_slen = 0; 861 hardwareAddress.sdl_alen = ETHER_ADDRESS_LENGTH; 862 memcpy(hardwareAddress.sdl_data, control.ethernet_address, 863 ETHER_ADDRESS_LENGTH); 864 865 return arp_update_entry(control.address, &hardwareAddress, 866 control.flags & (ARP_FLAG_PUBLISH | ARP_FLAG_PERMANENT 867 | ARP_FLAG_REJECT)); 868 } 869 870 case ARP_GET_ENTRY: 871 { 872 arp_entry *entry = arp_entry::Lookup(control.address); 873 if (entry == NULL || !(entry->flags & ARP_FLAG_VALID)) 874 return B_ENTRY_NOT_FOUND; 875 876 if (entry->hardware_address.sdl_alen == ETHER_ADDRESS_LENGTH) { 877 memcpy(control.ethernet_address, 878 entry->hardware_address.sdl_data, ETHER_ADDRESS_LENGTH); 879 } else 880 memset(control.ethernet_address, 0, ETHER_ADDRESS_LENGTH); 881 882 control.flags = entry->flags & ARP_PUBLIC_FLAG_MASK; 883 return user_memcpy(buffer, &control, sizeof(struct arp_control)); 884 } 885 886 case ARP_GET_ENTRIES: 887 { 888 hash_iterator iterator; 889 hash_open(sCache, &iterator); 890 891 arp_entry *entry; 892 uint32 i = 0; 893 while ((entry = (arp_entry *)hash_next(sCache, &iterator)) != NULL 894 && i < control.cookie) { 895 i++; 896 } 897 hash_close(sCache, &iterator, false); 898 899 if (entry == NULL) 900 return B_ENTRY_NOT_FOUND; 901 902 control.cookie++; 903 control.address = entry->protocol_address; 904 if (entry->hardware_address.sdl_alen == ETHER_ADDRESS_LENGTH) { 905 memcpy(control.ethernet_address, 906 entry->hardware_address.sdl_data, ETHER_ADDRESS_LENGTH); 907 } else 908 memset(control.ethernet_address, 0, ETHER_ADDRESS_LENGTH); 909 control.flags = entry->flags & ARP_PUBLIC_FLAG_MASK; 910 911 return user_memcpy(buffer, &control, sizeof(struct arp_control)); 912 } 913 914 case ARP_DELETE_ENTRY: 915 { 916 arp_entry *entry = arp_entry::Lookup(control.address); 917 if (entry == NULL) 918 return B_ENTRY_NOT_FOUND; 919 if ((entry->flags & ARP_FLAG_LOCAL) != 0) 920 return B_BAD_VALUE; 921 922 entry->ScheduleRemoval(); 923 return B_OK; 924 } 925 926 case ARP_FLUSH_ENTRIES: 927 { 928 hash_iterator iterator; 929 hash_open(sCache, &iterator); 930 931 arp_entry *entry; 932 while ((entry = (arp_entry *)hash_next(sCache, &iterator)) != NULL) { 933 // we never flush local ARP entries 934 if ((entry->flags & ARP_FLAG_LOCAL) != 0) 935 continue; 936 937 entry->ScheduleRemoval(); 938 } 939 hash_close(sCache, &iterator, false); 940 return B_OK; 941 } 942 943 case ARP_IGNORE_REPLIES: 944 sIgnoreReplies = control.flags != 0; 945 return B_OK; 946 } 947 948 return B_BAD_VALUE; 949 } 950 951 952 static status_t 953 arp_init() 954 { 955 mutex_init(&sCacheLock, "arp cache"); 956 957 sCache = hash_init(64, offsetof(struct arp_entry, next), 958 &arp_entry::Compare, &arp_entry::Hash); 959 if (sCache == NULL) { 960 mutex_destroy(&sCacheLock); 961 return B_NO_MEMORY; 962 } 963 964 register_generic_syscall(ARP_SYSCALLS, arp_control, 1, 0); 965 return B_OK; 966 } 967 968 969 static status_t 970 arp_uninit() 971 { 972 unregister_generic_syscall(ARP_SYSCALLS, 1); 973 return B_OK; 974 } 975 976 977 // #pragma mark - net_datalink_protocol 978 979 980 status_t 981 arp_init_protocol(net_interface* interface, net_domain* domain, 982 net_datalink_protocol** _protocol) 983 { 984 // We currently only support a single family and type! 985 if (interface->device->type != IFT_ETHER 986 || domain->family != AF_INET) 987 return B_BAD_TYPE; 988 989 status_t status = sStackModule->register_device_handler(interface->device, 990 B_NET_FRAME_TYPE(IFT_ETHER, ETHER_TYPE_ARP), &arp_receive, NULL); 991 if (status != B_OK) 992 return status; 993 994 status = sStackModule->register_domain_device_handler( 995 interface->device, B_NET_FRAME_TYPE(IFT_ETHER, ETHER_TYPE_IP), domain); 996 if (status != B_OK) 997 return status; 998 999 arp_protocol* protocol = new(std::nothrow) arp_protocol; 1000 if (protocol == NULL) 1001 return B_NO_MEMORY; 1002 1003 memset(&protocol->hardware_address, 0, sizeof(sockaddr_dl)); 1004 protocol->local_address = 0; 1005 1006 *_protocol = protocol; 1007 return B_OK; 1008 } 1009 1010 1011 status_t 1012 arp_uninit_protocol(net_datalink_protocol *protocol) 1013 { 1014 sStackModule->unregister_device_handler(protocol->interface->device, 1015 B_NET_FRAME_TYPE(IFT_ETHER, ETHER_TYPE_ARP)); 1016 sStackModule->unregister_device_handler(protocol->interface->device, 1017 B_NET_FRAME_TYPE(IFT_ETHER, ETHER_TYPE_IP)); 1018 1019 delete protocol; 1020 return B_OK; 1021 } 1022 1023 1024 status_t 1025 arp_send_data(net_datalink_protocol *_protocol, net_buffer *buffer) 1026 { 1027 arp_protocol *protocol = (arp_protocol *)_protocol; 1028 { 1029 MutexLocker locker(sCacheLock); 1030 1031 // Set buffer target and destination address 1032 1033 memcpy(buffer->source, &protocol->hardware_address, 1034 protocol->hardware_address.sdl_len); 1035 1036 if ((buffer->flags & MSG_MCAST) != 0) { 1037 sockaddr_dl multicastDestination; 1038 ipv4_to_ether_multicast(&multicastDestination, 1039 (sockaddr_in *)buffer->destination); 1040 memcpy(buffer->destination, &multicastDestination, 1041 sizeof(multicastDestination)); 1042 } else if ((buffer->flags & MSG_BCAST) == 0) { 1043 // Lookup destination (we may need to wait for this) 1044 arp_entry *entry = arp_entry::Lookup( 1045 ((struct sockaddr_in *)buffer->destination)->sin_addr.s_addr); 1046 if (entry == NULL) { 1047 status_t status = arp_start_resolve(protocol, 1048 ((struct sockaddr_in*)buffer->destination)->sin_addr.s_addr, 1049 &entry); 1050 if (status != B_OK) 1051 return status; 1052 } 1053 1054 if ((entry->flags & ARP_FLAG_REJECT) != 0) 1055 return EHOSTUNREACH; 1056 1057 if ((entry->flags & ARP_FLAG_VALID) == 0) { 1058 // entry is still being resolved. 1059 TRACE(("ARP Queuing packet %p, entry still being resolved.\n", 1060 buffer)); 1061 entry->queue.Add(buffer); 1062 return B_OK; 1063 } 1064 1065 memcpy(buffer->destination, &entry->hardware_address, 1066 entry->hardware_address.sdl_len); 1067 } 1068 // the broadcast address is set in the ethernet frame module 1069 } 1070 TRACE(("%s(%p): from %s\n", __FUNCTION__, buffer, 1071 mac_to_string(LLADDR((sockaddr_dl*)buffer->source)))); 1072 TRACE((" to %s\n", 1073 mac_to_string(LLADDR((sockaddr_dl*)buffer->destination)))); 1074 1075 return protocol->next->module->send_data(protocol->next, buffer); 1076 } 1077 1078 1079 status_t 1080 arp_up(net_datalink_protocol* _protocol) 1081 { 1082 arp_protocol* protocol = (arp_protocol*)_protocol; 1083 status_t status = protocol->next->module->interface_up(protocol->next); 1084 if (status != B_OK) 1085 return status; 1086 1087 // cache this device's address for later use 1088 1089 status = arp_update_local(protocol); 1090 if (status != B_OK) { 1091 protocol->next->module->interface_down(protocol->next); 1092 return status; 1093 } 1094 1095 return B_OK; 1096 } 1097 1098 1099 void 1100 arp_down(net_datalink_protocol *protocol) 1101 { 1102 // remove local ARP entries from the cache 1103 arp_remove_local((arp_protocol*)protocol); 1104 1105 protocol->next->module->interface_down(protocol->next); 1106 } 1107 1108 1109 status_t 1110 arp_change_address(net_datalink_protocol* _protocol, 1111 net_interface_address* address, int32 option, 1112 const struct sockaddr* oldAddress, const struct sockaddr* newAddress) 1113 { 1114 arp_protocol* protocol = (arp_protocol*)_protocol; 1115 TRACE(("%s(option %" B_PRId32 ")\n", __FUNCTION__, option)); 1116 1117 switch (option) { 1118 case SIOCSIFADDR: 1119 case SIOCAIFADDR: 1120 case SIOCDIFADDR: 1121 // Those are the options we handle 1122 if ((protocol->interface->flags & IFF_UP) != 0) { 1123 // Update ARP entry for the local address 1124 1125 if (newAddress != NULL && newAddress->sa_family == AF_INET) { 1126 status_t status = arp_set_local_entry(protocol, newAddress); 1127 if (status != B_OK) 1128 return status; 1129 } 1130 1131 if (option != SIOCAIFADDR 1132 && (oldAddress == NULL || oldAddress->sa_family == AF_INET)) 1133 arp_remove_local_entry(protocol, oldAddress, true); 1134 } 1135 break; 1136 1137 default: 1138 break; 1139 } 1140 1141 return protocol->next->module->change_address(protocol->next, address, 1142 option, oldAddress, newAddress); 1143 } 1144 1145 1146 status_t 1147 arp_control(net_datalink_protocol *_protocol, int32 op, void *argument, 1148 size_t length) 1149 { 1150 arp_protocol* protocol = (arp_protocol*)_protocol; 1151 return protocol->next->module->control(protocol->next, op, argument, 1152 length); 1153 } 1154 1155 1156 static status_t 1157 arp_join_multicast(net_datalink_protocol *protocol, const sockaddr *address) 1158 { 1159 if (address->sa_family != AF_INET) 1160 return EINVAL; 1161 1162 sockaddr_dl multicastAddress; 1163 ipv4_to_ether_multicast(&multicastAddress, (const sockaddr_in *)address); 1164 1165 return protocol->next->module->join_multicast(protocol->next, 1166 (sockaddr *)&multicastAddress); 1167 } 1168 1169 1170 static status_t 1171 arp_leave_multicast(net_datalink_protocol *protocol, const sockaddr *address) 1172 { 1173 if (address->sa_family != AF_INET) 1174 return EINVAL; 1175 1176 sockaddr_dl multicastAddress; 1177 ipv4_to_ether_multicast(&multicastAddress, (const sockaddr_in *)address); 1178 1179 return protocol->next->module->leave_multicast(protocol->next, 1180 (sockaddr *)&multicastAddress); 1181 } 1182 1183 1184 static status_t 1185 arp_std_ops(int32 op, ...) 1186 { 1187 switch (op) { 1188 case B_MODULE_INIT: 1189 return arp_init(); 1190 case B_MODULE_UNINIT: 1191 return arp_uninit(); 1192 1193 default: 1194 return B_ERROR; 1195 } 1196 } 1197 1198 1199 static net_datalink_protocol_module_info sARPModule = { 1200 { 1201 "network/datalink_protocols/arp/v1", 1202 0, 1203 arp_std_ops 1204 }, 1205 arp_init_protocol, 1206 arp_uninit_protocol, 1207 arp_send_data, 1208 arp_up, 1209 arp_down, 1210 arp_change_address, 1211 arp_control, 1212 arp_join_multicast, 1213 arp_leave_multicast, 1214 }; 1215 1216 1217 module_dependency module_dependencies[] = { 1218 {NET_STACK_MODULE_NAME, (module_info**)&sStackModule}, 1219 {NET_DATALINK_MODULE_NAME, (module_info**)&sDatalinkModule}, 1220 {NET_BUFFER_MODULE_NAME, (module_info**)&gBufferModule}, 1221 {} 1222 }; 1223 1224 module_info* modules[] = { 1225 (module_info*)&sARPModule, 1226 NULL 1227 }; 1228