mDNSCore/uDNS.h

   1 /* -*- Mode: C; tab-width: 4 -*-
   2  *
   3  * Copyright (c) 2002-2013 Apple Computer, Inc. All rights reserved.
   4  *
   5  * Licensed under the Apache License, Version 2.0 (the "License");
   6  * you may not use this file except in compliance with the License.
   7  * You may obtain a copy of the License at
   8  *
   9  *     http://www.apache.org/licenses/LICENSE-2.0
  10  *
  11  * Unless required by applicable law or agreed to in writing, software
  12  * distributed under the License is distributed on an "AS IS" BASIS,
  13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14  * See the License for the specific language governing permissions and
  15  * limitations under the License.
  16  */
  17
  18 #ifndef __UDNS_H_
  19 #define __UDNS_H_
  20
  21 #include "mDNSEmbeddedAPI.h"
  22 #include "DNSCommon.h"
  23
  24 #ifdef  __cplusplus
  25 extern "C" {
  26 #endif
  27
  28 #define RESTART_GOODBYE_DELAY    (6 * mDNSPlatformOneSecond) // delay after restarting LLQ before nuking previous known answers (avoids flutter if we restart before we have networking up)
  29 #define INIT_UCAST_POLL_INTERVAL (3 * mDNSPlatformOneSecond) // this interval is used after send failures on network transitions
  30                                                              // which typically heal quickly, so we start agressively and exponentially back off
  31 #define MAX_UCAST_POLL_INTERVAL (60 * 60 * mDNSPlatformOneSecond)
  32 //#define MAX_UCAST_POLL_INTERVAL (1 * 60 * mDNSPlatformOneSecond)
  33 #define LLQ_POLL_INTERVAL       (15 * 60 * mDNSPlatformOneSecond) // Polling interval for zones w/ an advertised LLQ port (ie not static zones) if LLQ fails due to NAT, etc.
  34 #define RESPONSE_WINDOW (60 * mDNSPlatformOneSecond)         // require server responses within one minute of request
  35 #define MAX_DNSSEC_UNANSWERED_QUERIES 1                      // number of unanswered queries from any one uDNS server before turning off DNSSEC Validation
  36 #define MAX_UCAST_UNANSWERED_QUERIES 2                       // number of unanswered queries from any one uDNS server before trying another server
  37 #define DNSSERVER_PENALTY_TIME (60 * mDNSPlatformOneSecond)  // number of seconds for which new questions don't pick this server
  38
  39 // On some interfaces, we want to delay the first retransmission to a minimum of 2 seconds
  40 // rather than the default (1 second).
  41 #define MIN_UCAST_RETRANS_TIMEOUT (2 * mDNSPlatformOneSecond)
  42
  43 #define DEFAULT_UPDATE_LEASE 7200
  44
  45 #define QuestionIntervalStep 3
  46 #define QuestionIntervalStep2 (QuestionIntervalStep*QuestionIntervalStep)
  47 #define QuestionIntervalStep3 (QuestionIntervalStep*QuestionIntervalStep*QuestionIntervalStep)
  48 #define InitialQuestionInterval ((mDNSPlatformOneSecond + QuestionIntervalStep-1) / QuestionIntervalStep)
  49 #define MaxQuestionInterval         (3600 * mDNSPlatformOneSecond)
  50 #define UDNSBackOffMultiplier 2
  51 #define MinQuestionInterval (1 * mDNSPlatformOneSecond)
  52
  53 // For Unicast record registrations, we initialize the interval to 1 second. When we send any query for
  54 // the record registration e.g., GetZoneData, we always back off by QuestionIntervalStep
  55 // so that the first retry does not happen until 3 seconds which should be enough for TCP/TLS to be done.
  56 #define INIT_RECORD_REG_INTERVAL (1 * mDNSPlatformOneSecond)
  57 #define MAX_RECORD_REG_INTERVAL (15 * 60 * mDNSPlatformOneSecond)
  58 #define MERGE_DELAY_TIME    (1 * mDNSPlatformOneSecond)
  59
  60 // If we are refreshing, we do it at least 5 times with a min update frequency of
  61 // 5 minutes
  62 #define MAX_UPDATE_REFRESH_COUNT    5
  63 #define MIN_UPDATE_REFRESH_TIME     (5 * 60 * mDNSPlatformOneSecond)
  64
  65 // For questions that use kDNSServiceFlagsTimeout and we don't have a matching resolver e.g., no dns servers,
  66 // then use the default value of 30 seconds
  67 #define DEFAULT_UDNS_TIMEOUT    30 // in seconds
  68
  69 // For questions that are validating responses (q->ValidatingResponse == 1), use 10 seconds
  70 // which accomodates two DNS servers and two queries per DNS server.
  71 #define DEFAULT_UDNSSEC_TIMEOUT    10 // in seconds
  72
  73 // If we are sending queries with EDNS0/DO option and we have no indications that the server
  74 // is DNSSEC aware and we have already reached MAX_DNSSEC_RETRANSMISSIONS, we disable
  75 // validation (for optional case only) for any questions that uses this server
  76 #define MAX_DNSSEC_RETRANSMISSIONS 3
  77
  78 // Entry points into unicast-specific routines
  79
  80 extern void LLQGotZoneData(mDNS *const m, mStatus err, const ZoneData *zoneInfo);
  81 extern void startLLQHandshake(mDNS *m, DNSQuestion *q);
  82 extern void sendLLQRefresh(mDNS *m, DNSQuestion *q);
  83
  84 extern void DNSPushNotificationGotZoneData(mDNS *const m, mStatus err, const ZoneData *zoneInfo);
  85 extern void DiscoverDNSPushNotificationServer(mDNS *m, DNSQuestion *q);
  86 extern void SubscribeToDNSPushNotificationServer(mDNS *m, DNSQuestion *q);
  87 extern void UnSubscribeToDNSPushNotificationServer(mDNS *m, DNSQuestion *q);
  88
  89 extern void SleepRecordRegistrations(mDNS *m);
  90
  91 // uDNS_UpdateRecord
  92 // following fields must be set, and the update validated, upon entry.
  93 // rr->NewRData
  94 // rr->newrdlength
  95 // rr->UpdateCallback
  96
  97 extern mStatus uDNS_UpdateRecord(mDNS *m, AuthRecord *rr);
  98
  99 extern void SetNextQueryTime(mDNS *const m, const DNSQuestion *const q);
 100 extern mStatus mDNS_Register_internal(mDNS *const m, AuthRecord *const rr);
 101 extern mStatus mDNS_Deregister_internal(mDNS *const m, AuthRecord *const rr, mDNS_Dereg_type drt);
 102 extern mStatus mDNS_StartQuery_internal(mDNS *const m, DNSQuestion *const question);
 103 extern mStatus mDNS_StopQuery_internal(mDNS *const m, DNSQuestion *const question);
 104 extern mStatus mDNS_StartNATOperation_internal(mDNS *const m, NATTraversalInfo *traversal);
 105
 106 extern void RecordRegistrationGotZoneData(mDNS *const m, mStatus err, const ZoneData *zoneData);
 107 extern mStatus uDNS_DeregisterRecord(mDNS *const m, AuthRecord *const rr);
 108 extern const domainname *GetServiceTarget(mDNS *m, AuthRecord *const rr);
 109 extern void uDNS_CheckCurrentQuestion(mDNS *const m);
 110
 111 // integer fields of msg header must be in HOST byte order before calling this routine
 112 extern void uDNS_ReceiveMsg(mDNS *const m, DNSMessage *const msg, const mDNSu8 *const end,
 113                             const mDNSAddr *const srcaddr, const mDNSIPPort srcport);
 114
 115 extern void uDNS_Tasks(mDNS *const m);
 116 extern void UpdateAllSRVRecords(mDNS *m);
 117 extern void CheckNATMappings(mDNS *m);
 118
 119 extern mStatus         uDNS_SetupDNSConfig(mDNS *const m);
 120
 121 // uDNS_SetupWABQueries reads search domains from the platform layer and starts the Wide Area Bonjour
 122 // (WAB) domain enumeration queries if necessary.
 123
 124 #define UDNS_WAB_BROWSE_QUERY    0x00000001 // Browse queries (b, db)
 125 #define UDNS_WAB_LBROWSE_QUERY   0x00000002 // Browse queries (lb)
 126 #define UDNS_WAB_REG_QUERY       0x00000004 // Registration queries (r and dr)
 127
 128 extern void uDNS_SetupWABQueries(mDNS *const m);
 129 extern void uDNS_StartWABQueries(mDNS *const m, int queryType);
 130 extern void uDNS_StopWABQueries(mDNS *const m, int queryType);
 131 extern domainname      *uDNS_GetNextSearchDomain(mDNS *const m, mDNSInterfaceID InterfaceID, mDNSs8 *searchIndex, mDNSBool ignoreDotLocal);
 132
 133 typedef enum
 134 {
 135     uDNS_LLQ_Not = 0,   // Normal uDNS answer: Flush any stale records from cache, and respect record TTL
 136     uDNS_LLQ_Ignore,    // LLQ initial challenge packet: ignore -- has no useful records for us
 137     uDNS_LLQ_Entire,    // LLQ initial set of answers: Flush any stale records from cache, but assume TTL is 2 x LLQ refresh interval
 138     uDNS_LLQ_Events     // LLQ event packet: don't flush cache; assume TTL is 2 x LLQ refresh interval
 139 } uDNS_LLQType;
 140
 141 extern uDNS_LLQType    uDNS_recvLLQResponse(mDNS *const m, const DNSMessage *const msg, const mDNSu8 *const end, const mDNSAddr *const srcaddr, const mDNSIPPort srcport, DNSQuestion **matchQuestion);
 142 extern DomainAuthInfo *GetAuthInfoForName_internal(mDNS *m, const domainname *const name);
 143 extern DomainAuthInfo *GetAuthInfoForQuestion(mDNS *m, const DNSQuestion *const q);
 144 extern void DisposeTCPConn(struct tcpInfo_t *tcp);
 145
 146 // NAT traversal
 147 extern void uDNS_ReceiveNATPacket(mDNS *m, const mDNSInterfaceID InterfaceID, mDNSu8 *pkt, mDNSu16 len); // Called for each received PCP or NAT-PMP packet
 148 extern void natTraversalHandleAddressReply(mDNS *const m, mDNSu16 err, mDNSv4Addr ExtAddr);
 149 extern void natTraversalHandlePortMapReply(mDNS *const m, NATTraversalInfo *n, const mDNSInterfaceID InterfaceID, mDNSu16 err, mDNSIPPort extport, mDNSu32 lease, NATTProtocol protocol);
 150
 151 // DNS Push Notification
 152 extern void SubscribeToDNSPushNotification(mDNS *m, DNSQuestion *q);
 153
 154
 155 #ifdef  __cplusplus
 156 }
 157 #endif
 158
 159 #endif // __UDNS_H_