versadac  1
versadac - Scalable Recorder Firmware
uDNS.h
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5  * Licensed under the Apache License, Version 2.0 (the "License");
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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 // On some interfaces, we want to delay the first retransmission to a minimum of 2 seconds
39 // rather than the default (1 second).
40 #define MIN_UCAST_RETRANS_TIMEOUT (2 * mDNSPlatformOneSecond)
41 
42 #define DEFAULT_UPDATE_LEASE 7200
43 
44 #define QuestionIntervalStep 3
45 #define QuestionIntervalStep2 (QuestionIntervalStep*QuestionIntervalStep)
46 #define QuestionIntervalStep3 (QuestionIntervalStep*QuestionIntervalStep*QuestionIntervalStep)
47 #define InitialQuestionInterval ((mDNSPlatformOneSecond + QuestionIntervalStep-1) / QuestionIntervalStep)
48 
49 // For Unicast record registrations, we initialize the interval to 1 second. When we send any query for
50 // the record registration e.g., GetZoneData, we always back off by QuestionIntervalStep
51 // so that the first retry does not happen until 3 seconds which should be enough for TCP/TLS to be done.
52 #define INIT_RECORD_REG_INTERVAL (1 * mDNSPlatformOneSecond)
53 #define MAX_RECORD_REG_INTERVAL (15 * 60 * mDNSPlatformOneSecond)
54 #define MERGE_DELAY_TIME (1 * mDNSPlatformOneSecond)
55 
56 // If we are refreshing, we do it at least 5 times with a min update frequency of
57 // 5 minutes
58 #define MAX_UPDATE_REFRESH_COUNT 5
59 #define MIN_UPDATE_REFRESH_TIME (5 * 60 * mDNSPlatformOneSecond)
60 
61 // For questions that use kDNSServiceFlagsTimeout and we don't have a matching resolver e.g., no dns servers,
62 // then use the default value of 30 seconds
63 #define DEFAULT_UDNS_TIMEOUT 30 // in seconds
64 
65 // Entry points into unicast-specific routines
66 
67 extern void LLQGotZoneData(mDNS *const m, mStatus err, const ZoneData *zoneInfo);
68 extern void startLLQHandshake(mDNS *m, DNSQuestion *q);
69 extern void sendLLQRefresh(mDNS *m, DNSQuestion *q);
70 
71 extern void SleepRecordRegistrations(mDNS *m);
72 
73 // uDNS_UpdateRecord
74 // following fields must be set, and the update validated, upon entry.
75 // rr->NewRData
76 // rr->newrdlength
77 // rr->UpdateCallback
78 
79 extern mStatus uDNS_UpdateRecord(mDNS *m, AuthRecord *rr);
80 
81 extern void SetNextQueryTime(mDNS *const m, const DNSQuestion *const q);
82 extern CacheGroup *CacheGroupForName(const mDNS *const m, const mDNSu32 slot, const mDNSu32 namehash, const domainname *const name);
83 extern mStatus mDNS_Register_internal(mDNS *const m, AuthRecord *const rr);
84 extern mStatus mDNS_Deregister_internal(mDNS *const m, AuthRecord *const rr, mDNS_Dereg_type drt);
85 extern mStatus mDNS_StartQuery_internal(mDNS *const m, DNSQuestion *const question);
86 extern mStatus mDNS_StopQuery_internal(mDNS *const m, DNSQuestion *const question);
87 extern mStatus mDNS_StartNATOperation_internal(mDNS *const m, NATTraversalInfo *traversal);
88 
89 extern void RecordRegistrationGotZoneData(mDNS *const m, mStatus err, const ZoneData *zoneData);
90 extern mStatus uDNS_DeregisterRecord(mDNS *const m, AuthRecord *const rr);
91 extern const domainname *GetServiceTarget(mDNS *m, AuthRecord *const rr);
92 extern void uDNS_CheckCurrentQuestion(mDNS *const m);
93 
94 // integer fields of msg header must be in HOST byte order before calling this routine
95 extern void uDNS_ReceiveMsg(mDNS *const m, DNSMessage *const msg, const mDNSu8 *const end,
96  const mDNSAddr *const srcaddr, const mDNSIPPort srcport);
97 
98 extern void uDNS_Tasks(mDNS *const m);
99 extern void UpdateAllSRVRecords(mDNS *m);
100 extern void CheckNATMappings(mDNS *m);
101 
102 extern mStatus uDNS_SetupDNSConfig(mDNS *const m);
103 
104 // uDNS_SetupSearchDomains by default adds search domains. It also can be called with one or
105 // more values for "action" which does the following:
106 //
107 // -UDNS_START_WAB_QUERY - start Wide Area Bonjour (domain enumeration) queries
108 
109 #define UDNS_START_WAB_QUERY 0x00000001
110 
111 extern mStatus uDNS_SetupSearchDomains(mDNS *const m, int action);
112 extern domainname *uDNS_GetNextSearchDomain(mDNS *const m, mDNSInterfaceID InterfaceID, mDNSs8 *searchIndex, mDNSBool ignoreDotLocal);
113 
114 typedef enum
115  {
116  uDNS_LLQ_Not = 0, // Normal uDNS answer: Flush any stale records from cache, and respect record TTL
117  uDNS_LLQ_Ignore, // LLQ initial challenge packet: ignore -- has no useful records for us
118  uDNS_LLQ_Entire, // LLQ initial set of answers: Flush any stale records from cache, but assume TTL is 2 x LLQ refresh interval
119  uDNS_LLQ_Events // LLQ event packet: don't flush cache; assume TTL is 2 x LLQ refresh interval
120  } uDNS_LLQType;
121 
122 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);
123 extern DomainAuthInfo *GetAuthInfoForName_internal(mDNS *m, const domainname *const name);
124 extern DomainAuthInfo *GetAuthInfoForQuestion(mDNS *m, const DNSQuestion *const q);
125 extern void DisposeTCPConn(struct tcpInfo_t *tcp);
126 
127 // NAT traversal
128 extern void uDNS_ReceiveNATPMPPacket(mDNS *m, const mDNSInterfaceID InterfaceID, mDNSu8 *pkt, mDNSu16 len); // Called for each received NAT-PMP packet
129 extern void natTraversalHandleAddressReply(mDNS *const m, mDNSu16 err, mDNSv4Addr ExtAddr);
130 extern void natTraversalHandlePortMapReply(mDNS *const m, NATTraversalInfo *n, const mDNSInterfaceID InterfaceID, mDNSu16 err, mDNSIPPort extport, mDNSu32 lease);
131 
132 #ifdef __cplusplus
133  }
134 #endif
135 
136 #endif // __UDNS_H_
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