mDNSCore/uDNS.h

   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_