mDNSCore/uDNS.h - platform/external/mdnsresponder - Git at Google

 /* -*- Mode: C; tab-width: 4 -*-
  *
  * Copyright (c) 2002-2003 Apple Computer, Inc. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *     http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 #ifndef __UDNS_H_
 #define __UDNS_H_

 #include "mDNSEmbeddedAPI.h"
 #include "DNSCommon.h"

 #ifdef	__cplusplus
 	extern "C" {
 #endif

 #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)
 #define INIT_UCAST_POLL_INTERVAL (3 * mDNSPlatformOneSecond) // this interval is used after send failures on network transitions
 	                                                         // which typically heal quickly, so we start agressively and exponentially back off
 #define MAX_UCAST_POLL_INTERVAL (60 * 60 * mDNSPlatformOneSecond)
 //#define MAX_UCAST_POLL_INTERVAL (1 * 60 * mDNSPlatformOneSecond)
 #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.
 #define RESPONSE_WINDOW (60 * mDNSPlatformOneSecond)         // require server responses within one minute of request
 #define MAX_UCAST_UNANSWERED_QUERIES 2                       // the number of unanswered queries from any one uDNS server before trying another server
 #define DNSSERVER_PENALTY_TIME (60 * mDNSPlatformOneSecond) // number of seconds for which new questions don't pick this server

 #define DEFAULT_UPDATE_LEASE 7200

 #define QuestionIntervalStep 3
 #define QuestionIntervalStep2 (QuestionIntervalStep*QuestionIntervalStep)
 #define QuestionIntervalStep3 (QuestionIntervalStep*QuestionIntervalStep*QuestionIntervalStep)
 #define InitialQuestionInterval ((mDNSPlatformOneSecond + QuestionIntervalStep-1) / QuestionIntervalStep)

 // For Unicast record registrations, we initialize the interval to 1 second. When we send any query for
 // the record registration e.g., GetZoneData, we always back off by QuestionIntervalStep
 // so that the first retry does not happen until 3 seconds which should be enough for TCP/TLS to be done.
 #define INIT_RECORD_REG_INTERVAL (1 * mDNSPlatformOneSecond)
 #define MAX_RECORD_REG_INTERVAL	(15 * 60 * mDNSPlatformOneSecond)
 #define MERGE_DELAY_TIME	(1 * mDNSPlatformOneSecond)

 // If we are refreshing, we do it at least 5 times with a min update frequency of
 // 5 minutes
 #define MAX_UPDATE_REFRESH_COUNT	5
 #define MIN_UPDATE_REFRESH_TIME		(5 * 60 * mDNSPlatformOneSecond)

 // For questions that use kDNSServiceFlagsTimeout and we don't have a matching resolver e.g., no dns servers,
 // then use the default value of 30 seconds
 #define DEFAULT_UDNS_TIMEOUT	30 // in seconds

 // Entry points into unicast-specific routines

 extern void LLQGotZoneData(mDNS *const m, mStatus err, const ZoneData *zoneInfo);
 extern void startLLQHandshake(mDNS *m, DNSQuestion *q);
 extern void sendLLQRefresh(mDNS *m, DNSQuestion *q);

 extern void SleepRecordRegistrations(mDNS *m);

 // uDNS_UpdateRecord
 // following fields must be set, and the update validated, upon entry.
 // rr->NewRData
 // rr->newrdlength
 // rr->UpdateCallback

 extern mStatus uDNS_UpdateRecord(mDNS *m, AuthRecord *rr);

 extern void SetNextQueryTime(mDNS *const m, const DNSQuestion *const q);
 extern CacheGroup *CacheGroupForName(const mDNS *const m, const mDNSu32 slot, const mDNSu32 namehash, const domainname *const name);
 extern mStatus mDNS_Register_internal(mDNS *const m, AuthRecord *const rr);
 extern mStatus mDNS_Deregister_internal(mDNS *const m, AuthRecord *const rr, mDNS_Dereg_type drt);
 extern mStatus mDNS_StartQuery_internal(mDNS *const m, DNSQuestion *const question);
 extern mStatus mDNS_StopQuery_internal(mDNS *const m, DNSQuestion *const question);
 extern mStatus mDNS_StartNATOperation_internal(mDNS *const m, NATTraversalInfo *traversal);

 extern void RecordRegistrationGotZoneData(mDNS *const m, mStatus err, const ZoneData *zoneData);
 extern mStatus uDNS_DeregisterRecord(mDNS *const m, AuthRecord *const rr);
 extern const domainname *GetServiceTarget(mDNS *m, AuthRecord *const rr);
 extern void uDNS_CheckCurrentQuestion(mDNS *const m);

 // integer fields of msg header must be in HOST byte order before calling this routine
 extern void uDNS_ReceiveMsg(mDNS *const m, DNSMessage *const msg, const mDNSu8 *const end,
 	const mDNSAddr *const srcaddr, const mDNSIPPort srcport);

 extern void uDNS_Tasks(mDNS *const m);
 extern void UpdateAllSRVRecords(mDNS *m);
 extern void CheckNATMappings(mDNS *m);

 extern mStatus         uDNS_SetupDNSConfig(mDNS *const m);

 // uDNS_SetupSearchDomains by default adds search domains. It also can be called with one or
 // more values for "action" which does the following:
 //
 // -UDNS_START_WAB_QUERY - start Wide Area Bonjour (domain enumeration) queries

 #define UDNS_START_WAB_QUERY    0x00000001

 extern mStatus         uDNS_SetupSearchDomains(mDNS *const m, int action);
 extern domainname      *uDNS_GetNextSearchDomain(mDNS *const m, mDNSInterfaceID InterfaceID, mDNSs8 *searchIndex, mDNSBool ignoreDotLocal);

 typedef enum
 	{
 	uDNS_LLQ_Not = 0,	// Normal uDNS answer: Flush any stale records from cache, and respect record TTL
 	uDNS_LLQ_Ignore,	// LLQ initial challenge packet: ignore -- has no useful records for us
 	uDNS_LLQ_Entire,	// LLQ initial set of answers: Flush any stale records from cache, but assume TTL is 2 x LLQ refresh interval
 	uDNS_LLQ_Events		// LLQ event packet: don't flush cache; assume TTL is 2 x LLQ refresh interval
 	} uDNS_LLQType;

 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);
 extern DomainAuthInfo *GetAuthInfoForName_internal(mDNS *m, const domainname *const name);
 extern DomainAuthInfo *GetAuthInfoForQuestion(mDNS *m, const DNSQuestion *const q);
 extern void DisposeTCPConn(struct tcpInfo_t *tcp);

 // NAT traversal
 extern void	uDNS_ReceiveNATPMPPacket(mDNS *m, const mDNSInterfaceID InterfaceID, mDNSu8 *pkt, mDNSu16 len);	// Called for each received NAT-PMP packet
 extern void	natTraversalHandleAddressReply(mDNS *const m, mDNSu16 err, mDNSv4Addr ExtAddr);
 extern void	natTraversalHandlePortMapReply(mDNS *const m, NATTraversalInfo *n, const mDNSInterfaceID InterfaceID, mDNSu16 err, mDNSIPPort extport, mDNSu32 lease);

 #ifdef	__cplusplus
 	}
 #endif

 #endif // __UDNS_H_
	/* -- Mode: C; tab-width: 4 --
	*
	* Copyright (c) 2002-2003 Apple Computer, Inc. All rights reserved.
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	#ifndef __UDNS_H_
	#define __UDNS_H_

	#include "mDNSEmbeddedAPI.h"
	#include "DNSCommon.h"

	#ifdef __cplusplus
	extern "C" {
	#endif

	#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)
	#define INIT_UCAST_POLL_INTERVAL (3 * mDNSPlatformOneSecond) // this interval is used after send failures on network transitions
	// which typically heal quickly, so we start agressively and exponentially back off
	#define MAX_UCAST_POLL_INTERVAL (60 * 60 * mDNSPlatformOneSecond)
	//#define MAX_UCAST_POLL_INTERVAL (1 * 60 * mDNSPlatformOneSecond)
	#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.
	#define RESPONSE_WINDOW (60 * mDNSPlatformOneSecond) // require server responses within one minute of request
	#define MAX_UCAST_UNANSWERED_QUERIES 2 // the number of unanswered queries from any one uDNS server before trying another server
	#define DNSSERVER_PENALTY_TIME (60 * mDNSPlatformOneSecond) // number of seconds for which new questions don't pick this server

	#define DEFAULT_UPDATE_LEASE 7200

	#define QuestionIntervalStep 3
	#define QuestionIntervalStep2 (QuestionIntervalStep*QuestionIntervalStep)
	#define QuestionIntervalStep3 (QuestionIntervalStepQuestionIntervalStepQuestionIntervalStep)
	#define InitialQuestionInterval ((mDNSPlatformOneSecond + QuestionIntervalStep-1) / QuestionIntervalStep)

	// For Unicast record registrations, we initialize the interval to 1 second. When we send any query for
	// the record registration e.g., GetZoneData, we always back off by QuestionIntervalStep
	// so that the first retry does not happen until 3 seconds which should be enough for TCP/TLS to be done.
	#define INIT_RECORD_REG_INTERVAL (1 * mDNSPlatformOneSecond)
	#define MAX_RECORD_REG_INTERVAL (15 * 60 * mDNSPlatformOneSecond)
	#define MERGE_DELAY_TIME (1 * mDNSPlatformOneSecond)

	// If we are refreshing, we do it at least 5 times with a min update frequency of
	// 5 minutes
	#define MAX_UPDATE_REFRESH_COUNT 5
	#define MIN_UPDATE_REFRESH_TIME (5 * 60 * mDNSPlatformOneSecond)

	// For questions that use kDNSServiceFlagsTimeout and we don't have a matching resolver e.g., no dns servers,
	// then use the default value of 30 seconds
	#define DEFAULT_UDNS_TIMEOUT 30 // in seconds

	// Entry points into unicast-specific routines

	extern void LLQGotZoneData(mDNS const m, mStatus err, const ZoneData zoneInfo);
	extern void startLLQHandshake(mDNS m, DNSQuestion q);
	extern void sendLLQRefresh(mDNS m, DNSQuestion q);

	extern void SleepRecordRegistrations(mDNS *m);

	// uDNS_UpdateRecord
	// following fields must be set, and the update validated, upon entry.
	// rr->NewRData
	// rr->newrdlength
	// rr->UpdateCallback

	extern mStatus uDNS_UpdateRecord(mDNS m, AuthRecord rr);

	extern void SetNextQueryTime(mDNS const m, const DNSQuestion const q);
	extern CacheGroup CacheGroupForName(const mDNS const m, const mDNSu32 slot, const mDNSu32 namehash, const domainname *const name);
	extern mStatus mDNS_Register_internal(mDNS const m, AuthRecord const rr);
	extern mStatus mDNS_Deregister_internal(mDNS const m, AuthRecord const rr, mDNS_Dereg_type drt);
	extern mStatus mDNS_StartQuery_internal(mDNS const m, DNSQuestion const question);
	extern mStatus mDNS_StopQuery_internal(mDNS const m, DNSQuestion const question);
	extern mStatus mDNS_StartNATOperation_internal(mDNS const m, NATTraversalInfo traversal);

	extern void RecordRegistrationGotZoneData(mDNS const m, mStatus err, const ZoneData zoneData);
	extern mStatus uDNS_DeregisterRecord(mDNS const m, AuthRecord const rr);
	extern const domainname GetServiceTarget(mDNS m, AuthRecord *const rr);
	extern void uDNS_CheckCurrentQuestion(mDNS *const m);

	// integer fields of msg header must be in HOST byte order before calling this routine
	extern void uDNS_ReceiveMsg(mDNS const m, DNSMessage const msg, const mDNSu8 *const end,
	const mDNSAddr *const srcaddr, const mDNSIPPort srcport);

	extern void uDNS_Tasks(mDNS *const m);
	extern void UpdateAllSRVRecords(mDNS *m);
	extern void CheckNATMappings(mDNS *m);

	extern mStatus uDNS_SetupDNSConfig(mDNS *const m);

	// uDNS_SetupSearchDomains by default adds search domains. It also can be called with one or
	// more values for "action" which does the following:
	//
	// -UDNS_START_WAB_QUERY - start Wide Area Bonjour (domain enumeration) queries

	#define UDNS_START_WAB_QUERY 0x00000001

	extern mStatus uDNS_SetupSearchDomains(mDNS *const m, int action);
	extern domainname uDNS_GetNextSearchDomain(mDNS const m, mDNSInterfaceID InterfaceID, mDNSs8 *searchIndex, mDNSBool ignoreDotLocal);

	typedef enum
	{
	uDNS_LLQ_Not = 0, // Normal uDNS answer: Flush any stale records from cache, and respect record TTL
	uDNS_LLQ_Ignore, // LLQ initial challenge packet: ignore -- has no useful records for us
	uDNS_LLQ_Entire, // LLQ initial set of answers: Flush any stale records from cache, but assume TTL is 2 x LLQ refresh interval
	uDNS_LLQ_Events // LLQ event packet: don't flush cache; assume TTL is 2 x LLQ refresh interval
	} uDNS_LLQType;

	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);
	extern DomainAuthInfo GetAuthInfoForName_internal(mDNS m, const domainname *const name);
	extern DomainAuthInfo GetAuthInfoForQuestion(mDNS m, const DNSQuestion *const q);
	extern void DisposeTCPConn(struct tcpInfo_t *tcp);

	// NAT traversal
	extern void uDNS_ReceiveNATPMPPacket(mDNS m, const mDNSInterfaceID InterfaceID, mDNSu8 pkt, mDNSu16 len); // Called for each received NAT-PMP packet
	extern void natTraversalHandleAddressReply(mDNS *const m, mDNSu16 err, mDNSv4Addr ExtAddr);
	extern void natTraversalHandlePortMapReply(mDNS const m, NATTraversalInfo n, const mDNSInterfaceID InterfaceID, mDNSu16 err, mDNSIPPort extport, mDNSu32 lease);

	#ifdef __cplusplus
	}
	#endif

	#endif // __UDNS_H_