xref: /illumos-gate/usr/src/contrib/mDNSResponder/mDNSCore/uDNS.h (revision a92282e44f968185a6bba094d1e5fece2da819cf)
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(mDNSInterfaceID InterfaceID, mDNSs8 *searchIndex, mDNSBool ignoreDotLocal);
132 
133 extern void uDNS_RestartQuestionAsTCP(mDNS *m, DNSQuestion *const q, const mDNSAddr *const srcaddr, const mDNSIPPort srcport);
134 
135 typedef enum
136 {
137     uDNS_LLQ_Not = 0,   // Normal uDNS answer: Flush any stale records from cache, and respect record TTL
138     uDNS_LLQ_Ignore,    // LLQ initial challenge packet: ignore -- has no useful records for us
139     uDNS_LLQ_Entire,    // LLQ initial set of answers: Flush any stale records from cache, but assume TTL is 2 x LLQ refresh interval
140     uDNS_LLQ_Events     // LLQ event packet: don't flush cache; assume TTL is 2 x LLQ refresh interval
141 } uDNS_LLQType;
142 
143 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);
144 extern DomainAuthInfo *GetAuthInfoForName_internal(mDNS *m, const domainname *const name);
145 extern DomainAuthInfo *GetAuthInfoForQuestion(mDNS *m, const DNSQuestion *const q);
146 extern void DisposeTCPConn(struct tcpInfo_t *tcp);
147 
148 // NAT traversal
149 extern void uDNS_ReceiveNATPacket(mDNS *m, const mDNSInterfaceID InterfaceID, mDNSu8 *pkt, mDNSu16 len); // Called for each received PCP or NAT-PMP packet
150 extern void natTraversalHandleAddressReply(mDNS *const m, mDNSu16 err, mDNSv4Addr ExtAddr);
151 extern void natTraversalHandlePortMapReply(mDNS *const m, NATTraversalInfo *n, const mDNSInterfaceID InterfaceID, mDNSu16 err, mDNSIPPort extport, mDNSu32 lease, NATTProtocol protocol);
152 
153 // DNS Push Notification
154 extern void SubscribeToDNSPushNotification(mDNS *m, DNSQuestion *q);
155 
156 
157 #ifdef  __cplusplus
158 }
159 #endif
160 
161 #endif // __UDNS_H
162