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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_
133