mDNSCore/uDNS.h

   1 /* -*- Mode: C; tab-width: 4 -*-
   2  *
   3  * Copyright (c) 2002-2003 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_UCAST_UNANSWERED_QUERIES 2                       // the number of unanswered queries from any one uDNS server before trying another server
  36 #define DNSSERVER_PENALTY_TIME (60 * mDNSPlatformOneSecond) // number of seconds for which new questions don't pick this server
  37
  38 // On some interfaces, we want to delay the first retransmission to a minimum of 2 seconds
  39 // rather than the default (1 second).
  40 #define MIN_UCAST_RETRANS_TIMEOUT (2 * mDNSPlatformOneSecond)
  41
  42 #define DEFAULT_UPDATE_LEASE 7200
  43
  44 #define QuestionIntervalStep 3
  45 #define QuestionIntervalStep2 (QuestionIntervalStep*QuestionIntervalStep)
  46 #define QuestionIntervalStep3 (QuestionIntervalStep*QuestionIntervalStep*QuestionIntervalStep)
  47 #define InitialQuestionInterval ((mDNSPlatformOneSecond + QuestionIntervalStep-1) / QuestionIntervalStep)
  48
  49 // For Unicast record registrations, we initialize the interval to 1 second. When we send any query for
  50 // the record registration e.g., GetZoneData, we always back off by QuestionIntervalStep
  51 // so that the first retry does not happen until 3 seconds which should be enough for TCP/TLS to be done.
  52 #define INIT_RECORD_REG_INTERVAL (1 * mDNSPlatformOneSecond)
  53 #define MAX_RECORD_REG_INTERVAL (15 * 60 * mDNSPlatformOneSecond)
  54 #define MERGE_DELAY_TIME    (1 * mDNSPlatformOneSecond)
  55
  56 // If we are refreshing, we do it at least 5 times with a min update frequency of
  57 // 5 minutes
  58 #define MAX_UPDATE_REFRESH_COUNT    5
  59 #define MIN_UPDATE_REFRESH_TIME     (5 * 60 * mDNSPlatformOneSecond)
  60
  61 // For questions that use kDNSServiceFlagsTimeout and we don't have a matching resolver e.g., no dns servers,
  62 // then use the default value of 30 seconds
  63 #define DEFAULT_UDNS_TIMEOUT    30 // in seconds
  64
  65 // For questions that are validating responses (q->ValidatingResponse == 1), use 10 seconds
  66 // which accomodates two DNS servers and two queries per DNS server.
  67 #define DEFAULT_UDNSSEC_TIMEOUT    10 // in seconds
  68
  69 // Entry points into unicast-specific routines
  70
  71 extern void LLQGotZoneData(mDNS *const m, mStatus err, const ZoneData *zoneInfo);
  72 extern void startLLQHandshake(mDNS *m, DNSQuestion *q);
  73 extern void sendLLQRefresh(mDNS *m, DNSQuestion *q);
  74
  75 extern void SleepRecordRegistrations(mDNS *m);
  76
  77 // uDNS_UpdateRecord
  78 // following fields must be set, and the update validated, upon entry.
  79 // rr->NewRData
  80 // rr->newrdlength
  81 // rr->UpdateCallback
  82
  83 extern mStatus uDNS_UpdateRecord(mDNS *m, AuthRecord *rr);
  84
  85 extern void SetNextQueryTime(mDNS *const m, const DNSQuestion *const q);
  86 extern mStatus mDNS_Register_internal(mDNS *const m, AuthRecord *const rr);
  87 extern mStatus mDNS_Deregister_internal(mDNS *const m, AuthRecord *const rr, mDNS_Dereg_type drt);
  88 extern mStatus mDNS_StartQuery_internal(mDNS *const m, DNSQuestion *const question);
  89 extern mStatus mDNS_StopQuery_internal(mDNS *const m, DNSQuestion *const question);
  90 extern mStatus mDNS_StartNATOperation_internal(mDNS *const m, NATTraversalInfo *traversal);
  91
  92 extern void RecordRegistrationGotZoneData(mDNS *const m, mStatus err, const ZoneData *zoneData);
  93 extern mStatus uDNS_DeregisterRecord(mDNS *const m, AuthRecord *const rr);
  94 extern const domainname *GetServiceTarget(mDNS *m, AuthRecord *const rr);
  95 extern void uDNS_CheckCurrentQuestion(mDNS *const m);
  96
  97 // integer fields of msg header must be in HOST byte order before calling this routine
  98 extern void uDNS_ReceiveMsg(mDNS *const m, DNSMessage *const msg, const mDNSu8 *const end,
  99                             const mDNSAddr *const srcaddr, const mDNSIPPort srcport);
 100
 101 extern void uDNS_Tasks(mDNS *const m);
 102 extern void UpdateAllSRVRecords(mDNS *m);
 103 extern void CheckNATMappings(mDNS *m);
 104
 105 extern mStatus         uDNS_SetupDNSConfig(mDNS *const m);
 106
 107 // uDNS_SetupSearchDomains by default adds search domains. It also can be called with one or
 108 // more values for "action" which does the following:
 109 //
 110 // -UDNS_START_WAB_QUERY - start Wide Area Bonjour (domain enumeration) queries
 111
 112 #define UDNS_START_WAB_QUERY    0x00000001
 113
 114 extern mStatus         uDNS_SetupSearchDomains(mDNS *const m, int action);
 115 extern domainname      *uDNS_GetNextSearchDomain(mDNS *const m, mDNSInterfaceID InterfaceID, mDNSs8 *searchIndex, mDNSBool ignoreDotLocal);
 116
 117 typedef enum
 118 {
 119     uDNS_LLQ_Not = 0,   // Normal uDNS answer: Flush any stale records from cache, and respect record TTL
 120     uDNS_LLQ_Ignore,    // LLQ initial challenge packet: ignore -- has no useful records for us
 121     uDNS_LLQ_Entire,    // LLQ initial set of answers: Flush any stale records from cache, but assume TTL is 2 x LLQ refresh interval
 122     uDNS_LLQ_Events     // LLQ event packet: don't flush cache; assume TTL is 2 x LLQ refresh interval
 123 } uDNS_LLQType;
 124
 125 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);
 126 extern DomainAuthInfo *GetAuthInfoForName_internal(mDNS *m, const domainname *const name);
 127 extern DomainAuthInfo *GetAuthInfoForQuestion(mDNS *m, const DNSQuestion *const q);
 128 extern void DisposeTCPConn(struct tcpInfo_t *tcp);
 129
 130 // NAT traversal
 131 extern void uDNS_ReceiveNATPMPPacket(mDNS *m, const mDNSInterfaceID InterfaceID, mDNSu8 *pkt, mDNSu16 len); // Called for each received NAT-PMP packet
 132 extern void natTraversalHandleAddressReply(mDNS *const m, mDNSu16 err, mDNSv4Addr ExtAddr);
 133 extern void natTraversalHandlePortMapReply(mDNS *const m, NATTraversalInfo *n, const mDNSInterfaceID InterfaceID, mDNSu16 err, mDNSIPPort extport, mDNSu32 lease);
 134
 135 #ifdef  __cplusplus
 136 }
 137 #endif
 138
 139 #endif // __UDNS_H_