15821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Copyright (c) 2012 The Chromium Authors. All rights reserved. 25821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Use of this source code is governed by a BSD-style license that can be 35821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// found in the LICENSE file. 45821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 55821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#ifndef NET_DNS_DNS_PROTOCOL_H_ 65821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#define NET_DNS_DNS_PROTOCOL_H_ 75821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 85821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "base/basictypes.h" 95821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "net/base/net_export.h" 105821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 115821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)namespace net { 125821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)namespace dns_protocol { 145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 155821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)static const uint16 kDefaultPort = 53; 167d4cd473f85ac64c3747c96c277f9e506a0d2246Torne (Richard Coles)static const uint16 kDefaultPortMulticast = 5353; 175821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 185821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// DNS packet consists of a header followed by questions and/or answers. 195821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// For the meaning of specific fields, please see RFC 1035 and 2535 205821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 215821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Header format. 225821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 1 1 1 1 1 1 235821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 245821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ 255821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// | ID | 265821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ 275821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// |QR| Opcode |AA|TC|RD|RA| Z|AD|CD| RCODE | 285821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ 295821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// | QDCOUNT | 305821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ 315821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// | ANCOUNT | 325821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ 335821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// | NSCOUNT | 345821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ 355821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// | ARCOUNT | 365821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ 375821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 385821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Question format. 395821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 1 1 1 1 1 1 405821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 415821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ 425821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// | | 435821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// / QNAME / 445821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// / / 455821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ 465821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// | QTYPE | 475821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ 485821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// | QCLASS | 495821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ 505821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 515821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Answer format. 525821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 1 1 1 1 1 1 535821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 545821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ 555821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// | | 565821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// / / 575821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// / NAME / 585821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// | | 595821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ 605821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// | TYPE | 615821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ 625821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// | CLASS | 635821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ 645821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// | TTL | 655821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// | | 665821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ 675821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// | RDLENGTH | 685821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--| 695821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// / RDATA / 705821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// / / 715821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ 725821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 735821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#pragma pack(push) 745821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#pragma pack(1) 755821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 765821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// On-the-wire header. All uint16 are in network order. 775821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Used internally in DnsQuery and DnsResponseParser. 785821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)struct NET_EXPORT_PRIVATE Header { 795821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) uint16 id; 805821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) uint16 flags; 815821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) uint16 qdcount; 825821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) uint16 ancount; 835821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) uint16 nscount; 845821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) uint16 arcount; 855821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)}; 865821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 875821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#pragma pack(pop) 885821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 895821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)static const uint8 kLabelMask = 0xc0; 905821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)static const uint8 kLabelPointer = 0xc0; 915821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)static const uint8 kLabelDirect = 0x0; 925821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)static const uint16 kOffsetMask = 0x3fff; 935821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 9490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)// In MDns the most significant bit of the rrclass is designated as the 9590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)// "cache-flush bit", as described in http://www.rfc-editor.org/rfc/rfc6762.txt 9690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)// section 10.2. 9790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)static const uint16 kMDnsClassMask = 0x7FFF; 9890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 995821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)static const int kMaxNameLength = 255; 1005821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1015821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// RFC 1035, section 4.2.1: Messages carried by UDP are restricted to 512 1025821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// bytes (not counting the IP nor UDP headers). 1035821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)static const int kMaxUDPSize = 512; 1045821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1057d4cd473f85ac64c3747c96c277f9e506a0d2246Torne (Richard Coles)// RFC 6762, section 17: Messages over the local link are restricted by the 1067d4cd473f85ac64c3747c96c277f9e506a0d2246Torne (Richard Coles)// medium's MTU, and must be under 9000 bytes 1077d4cd473f85ac64c3747c96c277f9e506a0d2246Torne (Richard Coles)static const int kMaxMulticastSize = 9000; 1087d4cd473f85ac64c3747c96c277f9e506a0d2246Torne (Richard Coles) 1095821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// DNS class types. 1105821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)static const uint16 kClassIN = 1; 1115821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1125821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// DNS resource record types. See 1135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// http://www.iana.org/assignments/dns-parameters 1145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)static const uint16 kTypeA = 1; 1155821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)static const uint16 kTypeCNAME = 5; 116c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles)static const uint16 kTypePTR = 12; 1175821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)static const uint16 kTypeTXT = 16; 1185821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)static const uint16 kTypeAAAA = 28; 119c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles)static const uint16 kTypeSRV = 33; 120eb525c5499e34cc9c4b825d6d9e75bb07cc06aceBen Murdochstatic const uint16 kTypeNSEC = 47; 121eb525c5499e34cc9c4b825d6d9e75bb07cc06aceBen Murdoch 1225821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1235821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// DNS rcode values. 1245821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)static const uint8 kRcodeMask = 0xf; 1255821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)static const uint8 kRcodeNOERROR = 0; 1265821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)static const uint8 kRcodeFORMERR = 1; 1275821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)static const uint8 kRcodeSERVFAIL = 2; 1285821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)static const uint8 kRcodeNXDOMAIN = 3; 1295821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)static const uint8 kRcodeNOTIMP = 4; 1305821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)static const uint8 kRcodeREFUSED = 5; 1315821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1325821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// DNS flags. 1335821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)static const uint16 kFlagResponse = 0x8000; 1345821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)static const uint16 kFlagRA = 0x80; 1355821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)static const uint16 kFlagRD = 0x100; 1365821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)static const uint16 kFlagTC = 0x200; 1375821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)static const uint16 kFlagAA = 0x400; 1385821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1395821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} // namespace dns_protocol 1405821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1415821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} // namespace net 1425821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1435821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#endif // NET_DNS_DNS_PROTOCOL_H_ 144