jens@26: //
jens@26: //  MYPortMapper.m
jens@26: //  MYNetwork
jens@26: //
jens@26: //  Created by Jens Alfke on 1/4/08.
jens@26: //  Copyright 2008 Jens Alfke. All rights reserved.
jens@26: //
jens@26: 
jens@26: #import "MYPortMapper.h"
jens@26: #import "IPAddress.h"
jens@26: #import "CollectionUtils.h"
jens@26: #import "Logging.h"
jens@26: #import "ExceptionUtils.h"
jens@26: 
jens@26: #import <dns_sd.h>
jens@26: #import <sys/types.h>
jens@26: #import <sys/socket.h>
jens@26: #import <net/if.h>
jens@26: #import <netinet/in.h>
jens@26: #import <ifaddrs.h>
jens@26: 
jens@26: 
jens@26: NSString* const MYPortMapperChangedNotification = @"MYPortMapperChanged";
jens@26: 
jens@26: 
jens@26: @interface MYPortMapper ()
jens@26: // Redeclare these properties as settable, internally:
jens@26: @property (readwrite) SInt32 error;
jens@26: @property (retain) IPAddress* publicAddress, *localAddress;
jens@26: // Private getter:
jens@26: @property (readonly) void* _service;
jens@26: - (void) priv_updateLocalAddress;
jens@26: - (void) priv_disconnect;
jens@26: @end
jens@26: 
jens@26: 
jens@26: @implementation MYPortMapper
jens@26: 
jens@26: 
jens@26: - (id) initWithLocalPort: (UInt16)localPort
jens@26: {
jens@26:     self = [super init];
jens@26:     if (self != nil) {
jens@26:         _localPort = localPort;
jens@26:         _mapTCP = YES;
jens@26:         [self priv_updateLocalAddress];
jens@26:     }
jens@26:     return self;
jens@26: }
jens@26: 
jens@26: - (id) initWithNullMapping
jens@26: {
jens@26:     // A PortMapper with no port or protocols will cause the DNSService to look up 
jens@26:     // our public address without creating a mapping.
jens@26:     if ([self initWithLocalPort: 0]) {
jens@26:         _mapTCP = _mapUDP = NO;
jens@26:     }
jens@26:     return self;
jens@26: }
jens@26: 
jens@26: 
jens@26: - (void) dealloc
jens@26: {
jens@26:     if( _service )
jens@26:         [self priv_disconnect];
jens@26:     [_publicAddress release];
jens@26:     [_localAddress release];
jens@26:     [super dealloc];
jens@26: }
jens@26: 
jens@26: - (void) finalize
jens@26: {
jens@26:     if( _service )
jens@26:         [self priv_disconnect];
jens@26:     [super finalize];
jens@26: }
jens@26: 
jens@26: 
jens@26: @synthesize localAddress=_localAddress, publicAddress=_publicAddress,
jens@26:             error=_error, _service=_service,
jens@26:             mapTCP=_mapTCP, mapUDP=_mapUDP,
jens@26:             desiredPublicPort=_desiredPublicPort;
jens@26: 
jens@26: 
jens@26: - (BOOL) isMapped
jens@26: {
jens@26:     return ! $equal(_publicAddress,_localAddress);
jens@26: }
jens@26: 
jens@26: - (void) priv_updateLocalAddress 
jens@26: {
jens@26:     IPAddress *localAddress = [IPAddress localAddressWithPort: _localPort];
jens@26:     if (!$equal(localAddress,_localAddress))
jens@26:         self.localAddress = localAddress;
jens@26: }
jens@26: 
jens@26: 
jens@26: static IPAddress* makeIPAddr( UInt32 rawAddr, UInt16 port ) {
jens@26:     if (rawAddr)
jens@26:         return [[[IPAddress alloc] initWithIPv4: rawAddr port: port] autorelease];
jens@26:     else
jens@26:         return nil;
jens@26: }
jens@26: 
jens@26: /** Called whenever the port mapping changes (see comment for callback, below.) */
jens@26: - (void) priv_portMapStatus: (DNSServiceErrorType)errorCode 
jens@26:               publicAddress: (UInt32)rawPublicAddress
jens@26:                  publicPort: (UInt16)publicPort
jens@26: {
jens@26:     LogTo(PortMapper,@"Callback got err %i, addr %08X:%hu",
jens@26:           errorCode, rawPublicAddress, publicPort);
jens@26:     if( errorCode==kDNSServiceErr_NoError ) {
jens@26:         if( rawPublicAddress==0 || (publicPort==0 && (_mapTCP || _mapUDP)) ) {
jens@26:             LogTo(PortMapper,@"(Callback reported no mapping available)");
jens@26:             errorCode = kDNSServiceErr_NATPortMappingUnsupported;
jens@26:         }
jens@26:     }
jens@26:     if( errorCode != self.error )
jens@26:         self.error = errorCode;
jens@26: 
jens@26:     [self priv_updateLocalAddress];
jens@26:     IPAddress *publicAddress = makeIPAddr(rawPublicAddress,publicPort);
jens@26:     if (!$equal(publicAddress,_publicAddress))
jens@26:         self.publicAddress = publicAddress;
jens@26:     
jens@26:     if( ! errorCode ) {
jens@26:         LogTo(PortMapper,@"Callback got %08X:%hu -> %@ (mapped=%i)",
jens@26:               rawPublicAddress,publicPort, self.publicAddress, self.isMapped);
jens@26:     }
jens@26:     [[NSNotificationCenter defaultCenter] postNotificationName: MYPortMapperChangedNotification
jens@26:                                                         object: self];
jens@26: }
jens@26: 
jens@26: 
jens@26: /** Asynchronous callback from DNSServiceNATPortMappingCreate.
jens@26:     This is invoked whenever the status of the port mapping changes.
jens@26:     All it does is dispatch to the object's priv_portMapStatus:publicAddress:publicPort: method. */
jens@26: static void portMapCallback (
jens@26:                       DNSServiceRef                    sdRef,
jens@26:                       DNSServiceFlags                  flags,
jens@26:                       uint32_t                         interfaceIndex,
jens@26:                       DNSServiceErrorType              errorCode,
jens@26:                       uint32_t                         publicAddress,    /* four byte IPv4 address in network byte order */
jens@26:                       DNSServiceProtocol               protocol,
jens@26:                       uint16_t                         privatePort,
jens@26:                       uint16_t                         publicPort,       /* may be different than the requested port */
jens@26:                       uint32_t                         ttl,              /* may be different than the requested ttl */
jens@26:                       void                             *context
jens@26:                       )
jens@26: {
jens@26:     NSAutoreleasePool *pool = [NSAutoreleasePool new];
jens@26:     @try{
jens@26:         [(MYPortMapper*)context priv_portMapStatus: errorCode 
jens@26:                                      publicAddress: publicAddress
jens@26:                                         publicPort: ntohs(publicPort)];  // port #s in network byte order!
jens@26:     }catchAndReport(@"PortMapper");
jens@26:     [pool drain];
jens@26: }
jens@26: 
jens@26: 
jens@26: /** CFSocket callback, informing us that _socket has data available, which means
jens@26:     that the DNS service has an incoming result to be processed. This will end up invoking
jens@26:     the portMapCallback. */
jens@26: static void serviceCallback(CFSocketRef s, 
jens@26:                             CFSocketCallBackType type,
jens@26:                             CFDataRef address, const void *data, void *clientCallBackInfo)
jens@26: {
jens@26:     MYPortMapper *mapper = (MYPortMapper*)clientCallBackInfo;
jens@26:     DNSServiceRef service = mapper._service;
jens@26:     DNSServiceErrorType err = DNSServiceProcessResult(service);
jens@26:     if( err ) {
jens@26:         // An error here means the socket has failed and should be closed.
jens@26:         [mapper priv_portMapStatus: err publicAddress: 0 publicPort: 0];
jens@26:         [mapper priv_disconnect];
jens@26:     }
jens@26: }
jens@26: 
jens@26: 
jens@26: 
jens@26: - (BOOL) open
jens@26: {
jens@26:     NSAssert(!_service,@"Already open");
jens@26:     // Create the DNSService:
jens@26:     DNSServiceProtocol protocols = 0;
jens@26:     if( _mapTCP ) protocols |= kDNSServiceProtocol_TCP;
jens@26:     if( _mapUDP ) protocols |= kDNSServiceProtocol_UDP;
jens@26:     self.error = DNSServiceNATPortMappingCreate((DNSServiceRef*)&_service, 
jens@26:                                          0 /*flags*/, 
jens@26:                                          0 /*interfaceIndex*/, 
jens@26:                                          protocols,
jens@26:                                          htons(_localPort),
jens@26:                                          htons(_desiredPublicPort),
jens@26:                                          0 /*ttl*/,
jens@26:                                          &portMapCallback, 
jens@26:                                          self);
jens@26:     if( _error ) {
jens@26:         LogTo(PortMapper,@"Error %i creating port mapping",_error);
jens@26:         return NO;
jens@26:     }
jens@26:     
jens@26:     // Wrap a CFSocket around the service's socket:
jens@26:     CFSocketContext ctxt = { 0, self, CFRetain, CFRelease, NULL };
jens@26:     _socket = CFSocketCreateWithNative(NULL, 
jens@26:                                        DNSServiceRefSockFD(_service), 
jens@26:                                        kCFSocketReadCallBack, 
jens@26:                                        &serviceCallback, &ctxt);
jens@26:     if( _socket ) {
jens@26:         CFSocketSetSocketFlags(_socket, CFSocketGetSocketFlags(_socket) & ~kCFSocketCloseOnInvalidate);
jens@26:         // Attach the socket to the runloop so the serviceCallback will be invoked:
jens@26:         _socketSource = CFSocketCreateRunLoopSource(NULL, _socket, 0);
jens@26:         if( _socketSource )
jens@26:             CFRunLoopAddSource(CFRunLoopGetCurrent(), _socketSource, kCFRunLoopCommonModes);
jens@26:     }
jens@26:     if( _socketSource ) {
jens@26:         LogTo(PortMapper,@"Opening");
jens@26:         return YES;
jens@26:     } else {
jens@26:         Warn(@"Failed to open PortMapper");
jens@26:         [self close];
jens@26:         _error = kDNSServiceErr_Unknown;
jens@26:         return NO;
jens@26:     }
jens@26: }
jens@26: 
jens@26: 
jens@26: - (BOOL) waitTillOpened
jens@26: {
jens@26:     if( ! _socketSource )
jens@26:         if( ! [self open] )
jens@26:             return NO;
jens@26:     // Run the runloop until there's either an error or a result:
jens@26:     while( _error==0 && _publicAddress==nil )
jens@26:         if( ! [[NSRunLoop currentRunLoop] runMode: NSDefaultRunLoopMode
jens@26:                                        beforeDate: [NSDate distantFuture]] )
jens@26:             break;
jens@26:     return (_error==0);
jens@26: }
jens@26: 
jens@26: 
jens@26: // Close down, but _without_ clearing the 'error' property
jens@26: - (void) priv_disconnect
jens@26: {
jens@26:     if( _socketSource ) {
jens@26:         CFRunLoopSourceInvalidate(_socketSource);
jens@26:         CFRelease(_socketSource);
jens@26:         _socketSource = NULL;
jens@26:     }
jens@26:     if( _socket ) {
jens@26:         CFSocketInvalidate(_socket);
jens@26:         CFRelease(_socket);
jens@26:         _socket = NULL;
jens@26:     }
jens@26:     if( _service ) {
jens@26:         LogTo(PortMapper,@"Deleting port mapping");
jens@26:         DNSServiceRefDeallocate(_service);
jens@26:         _service = NULL;
jens@26:         self.publicAddress = nil;
jens@26:     }
jens@26: }
jens@26: 
jens@26: - (void) close
jens@26: {
jens@26:     [self priv_disconnect];
jens@26:     self.error = 0;
jens@26: }
jens@26: 
jens@26: 
jens@26: + (IPAddress*) findPublicAddress
jens@26: {
jens@26:     IPAddress *addr = nil;
jens@26:     MYPortMapper *mapper = [[self alloc] initWithNullMapping];
jens@26:     if( [mapper waitTillOpened] )
jens@26:         addr = [mapper.publicAddress retain];
jens@26:     [mapper close];
jens@26:     [mapper release];
jens@26:     return [addr autorelease];
jens@26: }
jens@26: 
jens@26: 
jens@26: @end
jens@26: 
jens@26: 
jens@26: /*
jens@26:  Copyright (c) 2008-2009, Jens Alfke <jens@mooseyard.com>. All rights reserved.
jens@26:  
jens@26:  Redistribution and use in source and binary forms, with or without modification, are permitted
jens@26:  provided that the following conditions are met:
jens@26:  
jens@26:  * Redistributions of source code must retain the above copyright notice, this list of conditions
jens@26:  and the following disclaimer.
jens@26:  * Redistributions in binary form must reproduce the above copyright notice, this list of conditions
jens@26:  and the following disclaimer in the documentation and/or other materials provided with the
jens@26:  distribution.
jens@26:  
jens@26:  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR
jens@26:  IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND 
jens@26:  FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRI-
jens@26:  BUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
jens@26:  (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 
jens@26:   PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
jens@26:  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF 
jens@26:  THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
jens@26:  */