xref: /aosp_15_r20/external/mdnsresponder/mDNSShared/dnsextd.h (revision 48a54d368dc4fa860885eef7b70b6c53499e7c25)

/* -*- Mode: C; tab-width: 4 -*-
 *
 * Copyright (c) 2006 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 _dnsextd_h
#define _dnsextd_h


#include <mDNSEmbeddedAPI.h>
#include <DNSCommon.h>
#include <GenLinkedList.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>


#define LLQ_TABLESIZE	1024	// !!!KRS make this dynamically growable


typedef enum DNSZoneSpecType
{
	kDNSZonePublic,
	kDNSZonePrivate
} DNSZoneSpecType;


typedef struct DNSZone
{
	domainname				name;
	DNSZoneSpecType			type;
	DomainAuthInfo		*	updateKeys;	// linked list of keys for signing deletion updates
	DomainAuthInfo		*	queryKeys;	// linked list of keys for queries
	struct DNSZone		*	next;
} DNSZone;


typedef struct
	{
    struct sockaddr_in src;
    size_t len;
	DNSZone * zone;
	mDNSBool   isZonePublic;
    DNSMessage msg;
    // Note: extra storage for oversized (TCP) messages goes here
	} PktMsg;

// lease table entry
typedef struct RRTableElem
	{
    struct RRTableElem *next;
    struct sockaddr_in cli;   // client's source address
    long expire;              // expiration time, in seconds since epoch
    domainname zone;          // from zone field of update message
    domainname name;          // name of the record
    CacheRecord rr;           // last field in struct allows for allocation of oversized RRs
	} RRTableElem;

typedef enum
	{
	RequestReceived = 0,
	ChallengeSent   = 1,
	Established     = 2
	} LLQState;

typedef struct AnswerListElem
	{
    struct AnswerListElem *next;
    domainname name;
    mDNSu16 type;
    CacheRecord *KnownAnswers;  // All valid answers delivered to client
    CacheRecord *EventList;     // New answers (adds/removes) to be sent to client
    int refcount;
    mDNSBool UseTCP;            // Use TCP if UDP would cause truncation
    pthread_t tid;              // Allow parallel list updates
	} AnswerListElem;

// llq table entry
typedef struct LLQEntry
	{
    struct LLQEntry *next;
    struct sockaddr_in cli;   // clien'ts source address
    domainname qname;
    mDNSu16 qtype;
    mDNSOpaque64 id;
    LLQState state;
    mDNSu32 lease;            // original lease, in seconds
    mDNSs32 expire;           // expiration, absolute, in seconds since epoch
    AnswerListElem *AnswerList;
	} LLQEntry;


typedef	void (*EventCallback)( void * context );

typedef struct EventSource
	{
	EventCallback			callback;
	void				*	context;
	TCPSocket *			sock;
	int						fd;
	mDNSBool				markedForDeletion;
	struct  EventSource	*	next;
	} EventSource;


// daemon-wide information
typedef struct
	{
    // server variables - read only after initialization (no locking)
	struct sockaddr_in	addr;			// the address we will bind to
	struct sockaddr_in	llq_addr;		// the address we will receive llq requests on.
    struct sockaddr_in	ns_addr;		// the real ns server address
	int					tcpsd;			// listening TCP socket for dns requests
	int					udpsd;			// listening UDP socket for dns requests
	int					tlssd;			// listening TCP socket for private browsing
    int					llq_tcpsd;		// listening TCP socket for llq service
    int					llq_udpsd;		// listening UDP socket for llq service
	DNameListElem	*	public_names;	// list of public SRV names
	DNSZone			*	zones;

    // daemon variables - read only after initialization (no locking)
    mDNSIPPort private_port;           // listening port for private messages
    mDNSIPPort llq_port;           // listening port for llq

    // lease table variables (locked via mutex after initialization)
    RRTableElem **table;       // hashtable for records with leases
    pthread_mutex_t tablelock; // mutex for lease table
    mDNSs32 nbuckets;          // buckets allocated
    mDNSs32 nelems;            // elements in table

    // LLQ table variables
    LLQEntry *LLQTable[LLQ_TABLESIZE];  // !!!KRS change this and RRTable to use a common data structure
    AnswerListElem *AnswerTable[LLQ_TABLESIZE];
    int AnswerTableCount;
    int LLQEventNotifySock;          // Unix domain socket pair - update handling thread writes to EventNotifySock, which wakes
    int LLQEventListenSock;          // the main thread listening on EventListenSock, indicating that the zone has changed

	GenLinkedList	eventSources;	// linked list of EventSource's
	} DaemonInfo;


int
ParseConfig
	(
	DaemonInfo	*	d,
	const char	*	file
	);


#endif