1 /* 2 * Copyright (c) 2002-2020 Apple Inc. All rights reserved. 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #ifndef __UDNS_H_ 18 #define __UDNS_H_ 19 20 #include "mDNSEmbeddedAPI.h" 21 #include "DNSCommon.h" 22 #include <sys/types.h> 23 #include "dns_sd.h" 24 25 #if MDNSRESPONDER_SUPPORTS(COMMON, DNS_PUSH) 26 #include "dso.h" 27 #include "dso-transport.h" 28 #endif 29 30 #ifdef __cplusplus 31 extern "C" { 32 #endif 33 34 #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) 35 #define INIT_UCAST_POLL_INTERVAL (3 * mDNSPlatformOneSecond) // this interval is used after send failures on network transitions 36 // which typically heal quickly, so we start agressively and exponentially back off 37 #define MAX_UCAST_POLL_INTERVAL (60 * 60 * mDNSPlatformOneSecond) 38 //#define MAX_UCAST_POLL_INTERVAL (1 * 60 * mDNSPlatformOneSecond) 39 #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. 40 #define RESPONSE_WINDOW (60 * mDNSPlatformOneSecond) // require server responses within one minute of request 41 #define MAX_UCAST_UNANSWERED_QUERIES 2 // number of unanswered queries from any one uDNS server before trying another server 42 #define DNSSERVER_PENALTY_TIME (60 * mDNSPlatformOneSecond) // number of seconds for which new questions don't pick this server 43 44 // On some interfaces, we want to delay the first retransmission to a minimum of 2 seconds 45 // rather than the default (1 second). 46 #define MIN_UCAST_RETRANS_TIMEOUT (2 * mDNSPlatformOneSecond) 47 48 #define DEFAULT_UPDATE_LEASE 7200 49 50 #define QuestionIntervalStep 3 51 #define QuestionIntervalStep2 (QuestionIntervalStep*QuestionIntervalStep) 52 #define QuestionIntervalStep3 (QuestionIntervalStep*QuestionIntervalStep*QuestionIntervalStep) 53 #define InitialQuestionInterval ((mDNSPlatformOneSecond + QuestionIntervalStep-1) / QuestionIntervalStep) 54 #define MaxQuestionInterval (3600 * mDNSPlatformOneSecond) 55 #define UDNSBackOffMultiplier 2 56 #define MinQuestionInterval (1 * mDNSPlatformOneSecond) 57 58 // For Unicast record registrations, we initialize the interval to 1 second. When we send any query for 59 // the record registration e.g., GetZoneData, we always back off by QuestionIntervalStep 60 // so that the first retry does not happen until 3 seconds which should be enough for TCP/TLS to be done. 61 #define INIT_RECORD_REG_INTERVAL (1 * mDNSPlatformOneSecond) 62 #define MAX_RECORD_REG_INTERVAL (15 * 60 * mDNSPlatformOneSecond) 63 #define MERGE_DELAY_TIME (1 * mDNSPlatformOneSecond) 64 65 // If we are refreshing, we do it at least 5 times with a min update frequency of 66 // 5 minutes 67 #define MAX_UPDATE_REFRESH_COUNT 5 68 #define MIN_UPDATE_REFRESH_TIME (5 * 60 * mDNSPlatformOneSecond) 69 70 // For questions that use kDNSServiceFlagsTimeout and we don't have a matching resolver e.g., no dns servers, 71 // then use the default value of 30 seconds 72 #define DEFAULT_UDNS_TIMEOUT 30 // in seconds 73 74 #if MDNSRESPONDER_SUPPORTS(COMMON, DNS_PUSH) 75 // Push notification structures 76 struct mDNS_DNSPushNotificationServer 77 { 78 dso_connect_state_t *connectInfo; // DSO Connection state information 79 dso_state_t *connection; // DNS Stateful Operations/TCP Connection pointer, might be null. 80 mDNSu32 numberOfQuestions; // Number of questions for this server 81 DNSPushServer_ConnectState connectState; // Current status of connection attempt to this server 82 mDNSs32 lastDisconnect; // Last time we got a disconnect, used to avoid constant reconnects 83 domainname serverName; // The hostname returned by the _dns-push-tls._tcp.<zone> SRV lookup 84 mDNSIPPort port; // The port from the SRV lookup 85 #if MDNSRESPONDER_SUPPORTS(APPLE, QUERIER) 86 mdns_dns_service_t dnsservice; 87 #else 88 DNSServer *qDNSServer; // DNS server stolen from the question that created this server structure. 89 #endif 90 mDNS *m; 91 DNSPushNotificationServer *next; 92 } ; 93 94 struct mDNS_DNSPushNotificationZone 95 { 96 domainname zoneName; 97 DNSPushNotificationServer *server; // DNS Push Notification Servers for this zone 98 mDNSu32 numberOfQuestions; // Number of questions for this zone 99 DNSPushNotificationZone *next; 100 } ; 101 #endif 102 103 // Entry points into unicast-specific routines 104 105 extern void LLQGotZoneData(mDNS *const m, mStatus err, const ZoneData *zoneInfo); 106 extern void startLLQHandshake(mDNS *m, DNSQuestion *q); 107 extern void sendLLQRefresh(mDNS *m, DNSQuestion *q); 108 109 #if MDNSRESPONDER_SUPPORTS(COMMON, DNS_PUSH) 110 extern void DNSPushNotificationGotZoneData(mDNS *const m, mStatus err, const ZoneData *zoneInfo); 111 extern void DiscoverDNSPushNotificationServer(mDNS *m, DNSQuestion *q); 112 extern DNSPushNotificationServer *GetConnectionToDNSPushNotificationServer(mDNS *m, DNSQuestion *q); 113 extern DNSPushNotificationServer *SubscribeToDNSPushNotificationServer(mDNS *m, DNSQuestion *q); 114 extern void UnSubscribeToDNSPushNotificationServer(mDNS *m, DNSQuestion *q); 115 extern void DNSPushReconcileConnection(mDNS *m, DNSQuestion *q); 116 extern void DNSPushServerDrop(DNSPushNotificationServer *server); 117 #endif 118 119 extern void SleepRecordRegistrations(mDNS *m); 120 121 // uDNS_UpdateRecord 122 // following fields must be set, and the update validated, upon entry. 123 // rr->NewRData 124 // rr->newrdlength 125 // rr->UpdateCallback 126 127 extern mStatus uDNS_UpdateRecord(mDNS *m, AuthRecord *rr); 128 129 extern void SetNextQueryTime(mDNS *const m, const DNSQuestion *const q); 130 extern mStatus mDNS_Register_internal(mDNS *const m, AuthRecord *const rr); 131 extern mStatus mDNS_Deregister_internal(mDNS *const m, AuthRecord *const rr, mDNS_Dereg_type drt); 132 extern mStatus mDNS_StartQuery_internal(mDNS *const m, DNSQuestion *const question); 133 extern mStatus mDNS_StopQuery_internal(mDNS *const m, DNSQuestion *const question); 134 extern mStatus mDNS_StartNATOperation_internal(mDNS *const m, NATTraversalInfo *traversal); 135 136 extern void RecordRegistrationGotZoneData(mDNS *const m, mStatus err, const ZoneData *zoneData); 137 extern mStatus uDNS_DeregisterRecord(mDNS *const m, AuthRecord *const rr); 138 extern const domainname *GetServiceTarget(mDNS *m, AuthRecord *const rr); 139 140 // integer fields of msg header must be in HOST byte order before calling this routine 141 extern void uDNS_ReceiveMsg(mDNS *const m, DNSMessage *const msg, const mDNSu8 *const end, 142 const mDNSAddr *const srcaddr, const mDNSIPPort srcport); 143 144 extern void uDNS_Tasks(mDNS *const m); 145 extern void UpdateAllSRVRecords(mDNS *m); 146 extern void CheckNATMappings(mDNS *m); 147 148 extern mStatus uDNS_SetupDNSConfig(mDNS *const m); 149 150 // uDNS_SetupWABQueries reads search domains from the platform layer and starts the Wide Area Bonjour 151 // (WAB) domain enumeration queries if necessary. 152 153 #define UDNS_WAB_BROWSE_QUERY 0x00000001 // Browse queries (b, db) 154 #define UDNS_WAB_LBROWSE_QUERY 0x00000002 // Browse queries (lb) 155 #define UDNS_WAB_REG_QUERY 0x00000004 // Registration queries (r and dr) 156 157 extern void uDNS_SetupWABQueries(mDNS *const m); 158 extern void uDNS_StartWABQueries(mDNS *const m, int queryType); 159 extern void uDNS_StopWABQueries(mDNS *const m, int queryType); 160 extern domainname *uDNS_GetNextSearchDomain(mDNSInterfaceID InterfaceID, int *searchIndex, mDNSBool ignoreDotLocal); 161 162 extern void uDNS_RestartQuestionAsTCP(mDNS *m, DNSQuestion *const q, const mDNSAddr *const srcaddr, const mDNSIPPort srcport); 163 164 typedef enum 165 { 166 uDNS_LLQ_Not = 0, // Normal uDNS answer: Flush any stale records from cache, and respect record TTL 167 uDNS_LLQ_Ignore, // LLQ initial challenge packet: ignore -- has no useful records for us 168 uDNS_LLQ_Entire, // LLQ initial set of answers: Flush any stale records from cache, but assume TTL is 2 x LLQ refresh interval 169 uDNS_LLQ_Events // LLQ event packet: don't flush cache; assume TTL is 2 x LLQ refresh interval 170 } uDNS_LLQType; 171 172 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); 173 extern DomainAuthInfo *GetAuthInfoForName_internal(mDNS *m, const domainname *const name); 174 extern DomainAuthInfo *GetAuthInfoForQuestion(mDNS *m, const DNSQuestion *const q); 175 extern void DisposeTCPConn(struct tcpInfo_t *tcp); 176 177 // NAT traversal 178 extern void uDNS_ReceiveNATPacket(mDNS *m, const mDNSInterfaceID InterfaceID, mDNSu8 *pkt, mDNSu16 len); // Called for each received PCP or NAT-PMP packet 179 extern void natTraversalHandleAddressReply(mDNS *const m, mDNSu16 err, mDNSv4Addr ExtAddr); 180 extern void natTraversalHandlePortMapReply(mDNS *const m, NATTraversalInfo *n, const mDNSInterfaceID InterfaceID, mDNSu16 err, mDNSIPPort extport, mDNSu32 lease, NATTProtocol protocol); 181 182 #if MDNSRESPONDER_SUPPORTS(COMMON, DNS_PUSH) 183 // DNS Push Notification 184 extern void SubscribeToDNSPushNotification(mDNS *m, DNSQuestion *q); 185 #endif 186 187 extern CacheRecord* mDNSCoreReceiveCacheCheck(mDNS *const m, const DNSMessage *const response, uDNS_LLQType LLQType, 188 const mDNSu32 slot, CacheGroup *cg, 189 CacheRecord ***cfp, mDNSInterfaceID InterfaceID); 190 #ifdef __cplusplus 191 } 192 #endif 193 194 #endif // __UDNS_H 195