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