HTTPConnection.m

#import "AsyncSocket.h"
#import "HTTPServer.h"
#import "HTTPConnection.h"
#import "HTTPResponse.h"
#import "HTTPAuthenticationRequest.h"
#import "DDNumber.h"
#import "DDRange.h"
#import "DDData.h"

// Define chunk size used to read in data for responses
// This is how much data will be read from disk into RAM at a time
#if TARGET_OS_IPHONE
#define READ_CHUNKSIZE  (1024 * 128)
#else
#define READ_CHUNKSIZE  (1024 * 512)
#endif

// Define chunk size used to read in POST upload data
#if TARGET_OS_IPHONE
#define POST_CHUNKSIZE  (1024 * 32)
#else
#define POST_CHUNKSIZE  (1024 * 128)
#endif

// Define the various timeouts (in seconds) for various parts of the HTTP process
#define READ_TIMEOUT          -1
#define WRITE_HEAD_TIMEOUT    30
#define WRITE_BODY_TIMEOUT    -1
#define WRITE_ERROR_TIMEOUT   30
#define NONCE_TIMEOUT        300

// Define the various limits
// LIMIT_MAX_HEADER_LINE_LENGTH: Max length (in bytes) of any single line in a header (including \r\n)
// LIMIT_MAX_HEADER_LINES      : Max number of lines in a single header (including first GET line)
#define LIMIT_MAX_HEADER_LINE_LENGTH  8190
#define LIMIT_MAX_HEADER_LINES         100

// Define the various tags we'll use to differentiate what it is we're currently doing
#define HTTP_REQUEST_HEADER                15
#define HTTP_REQUEST_BODY                  16
#define HTTP_PARTIAL_RESPONSE              24
#define HTTP_PARTIAL_RESPONSE_HEADER       25
#define HTTP_PARTIAL_RESPONSE_BODY         26
#define HTTP_PARTIAL_RANGE_RESPONSE_BODY   28
#define HTTP_PARTIAL_RANGES_RESPONSE_BODY  29
#define HTTP_RESPONSE                      30
#define HTTP_FINAL_RESPONSE                45

// A quick note about the tags:
// 
// The HTTP_RESPONSE and HTTP_FINAL_RESPONSE are designated tags signalling that the response is completely sent.
// That is, in the onSocket:didWriteDataWithTag: method, if the tag is HTTP_RESPONSE or HTTP_FINAL_RESPONSE,
// it is assumed that the response is now completely sent.
// Use HTTP_RESPONSE if it's the end of a response, and you want to start reading more requests afterwards.
// Use HTTP_FINAL_RESPONSE if you wish to terminate the connection after sending the response.
// 
// If you are sending multiple data segments in a custom response, make sure that only the last segment has
// the HTTP_RESPONSE tag. For all other segments prior to the last segment use HTTP_PARTIAL_RESPONSE, or some other
// tag of your own invention.

@interface HTTPConnection (PrivateAPI)
- (CFHTTPMessageRef)prepareUniRangeResponse:(UInt64)contentLength;
- (CFHTTPMessageRef)prepareMultiRangeResponse:(UInt64)contentLength;
@end

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
#pragma mark -
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

@implementation HTTPConnection

static NSMutableArray *recentNonces;

/**
 * This method is automatically called (courtesy of Cocoa) before the first instantiation of this class.
 * We use it to initialize any static variables.
**/
+ (void)initialize
{
	static BOOL initialized = NO;
	if(!initialized)
	{
		// Initialize class variables
		recentNonces = [[NSMutableArray alloc] initWithCapacity:5];
		
		initialized = YES;
	}
}

/**
 * This method is designed to be called by a scheduled timer, and will remove a nonce from the recent nonce list.
 * The nonce to remove should be set as the timer's userInfo.
**/
+ (void)removeRecentNonce:(NSTimer *)aTimer
{
	[recentNonces removeObject:[aTimer userInfo]];
}

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
#pragma mark Init, Dealloc:
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

/**
 * Sole Constructor.
 * Associates this new HTTP connection with the given AsyncSocket.
 * This HTTP connection object will become the socket's delegate and take over responsibility for the socket.
**/
- (id)initWithAsyncSocket:(AsyncSocket *)newSocket forServer:(HTTPServer *)myServer
{
	if(self = [super init])
	{
		// Take over ownership of the socket
		asyncSocket = [newSocket retain];
		[asyncSocket setDelegate:self];
		
		// Enable pre-buffering on the socket to improve readDataToData performance
		[asyncSocket enablePreBuffering];
		
		// Store reference to server
		// Note that we do not retain the server. Parents retain their children, children do not retain their parents.
		server = myServer;
		
		// Initialize lastNC (last nonce count)
		// These must increment for each request from the client
		lastNC = 0;
		
		// Create a new HTTP message
		// Note the second parameter is YES, because it will be used for HTTP requests from the client
		request = CFHTTPMessageCreateEmpty(kCFAllocatorDefault, YES);
		
		numHeaderLines = 0;
		
		// Don't start reading the HTTP request here.
		// We are currently running on the thread that the server's listen socket is running on.
		// However, the server may place us on a different thread.
		// We should only read/write to our socket on its proper thread.
		// Instead, we'll wait for the call to onSocket:didConnectToHost:port: which will be on the proper thread.
	}
	return self;
}

/**
 * Standard Deconstructor.
**/
- (void)dealloc
{
	[asyncSocket setDelegate:nil];
	[asyncSocket disconnect];
	[asyncSocket release];
	
	if(request) CFRelease(request);
	
	[nonce release];
	
	[httpResponse release];
	
	[ranges release];
	[ranges_headers release];
	[ranges_boundry release];
	
	[super dealloc];
}

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
#pragma mark Connection Control:
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

/**
 * Returns whether or not the server will accept messages of a given method
 * at a particular URI.
**/
- (BOOL)supportsMethod:(NSString *)method atPath:(NSString *)relativePath
{
	// Override me to support methods such as POST.
	// 
	// Things you may want to consider:
	// - Does the given path represent a resource that is designed to accept this method?
	// - If accepting an upload, is the size of the data being uploaded too big?
	// 
	// For more information, you can always access the CFHTTPMessageRef request variable.
	
	if([method isEqualToString:@"GET"])
		return YES;
	if([method isEqualToString:@"HEAD"])
		return YES;
		
	return NO;
}

/**
 * Returns whether or not the server is configured to be a secure server.
 * In other words, all connections to this server are immediately secured, thus only secure connections are allowed.
 * This is the equivalent of having an https server, where it is assumed that all connections must be secure.
 * If this is the case, then unsecure connections will not be allowed on this server, and a separate unsecure server
 * would need to be run on a separate port in order to support unsecure connections.
 * 
 * Note: In order to support secure connections, the sslIdentityAndCertificates method must be implemented.
**/
- (BOOL)isSecureServer
{
	// Override me to create an https server...
	
	return NO;
}

/**
 * This method is expected to returns an array appropriate for use in kCFStreamSSLCertificates SSL Settings.
 * It should be an array of SecCertificateRefs except for the first element in the array, which is a SecIdentityRef.
**/
- (NSArray *)sslIdentityAndCertificates
{
	// Override me to provide the proper required SSL identity.
	// You can configure the identity for the entire server, or based on the current request
	
	return nil;
}

/**
 * Returns whether or not the requested resource is password protected.
 * In this generic implementation, nothing is password protected.
**/
- (BOOL)isPasswordProtected:(NSString *)path
{
	// Override me to provide password protection...
	// You can configure it for the entire server, or based on the current request
	
	return NO;
}

/**
 * Returns whether or not the authentication challenge should use digest access authentication.
 * The alternative is basic authentication.
 * 
 * If at all possible, digest access authentication should be used because it's more secure.
 * Basic authentication sends passwords in the clear and should be avoided unless using SSL/TLS.
**/
- (BOOL)useDigestAccessAuthentication
{
	// Override me to use customize the authentication scheme
	// Make sure you understand the security consequences of using basic authentication
	
	return YES;
}

/**
 * Returns the authentication realm.
 * In this generic implmentation, a default realm is used for the entire server.
**/
- (NSString *)realm
{
	// Override me to provide a custom realm...
	// You can configure it for the entire server, or based on the current request
	
	return @"defaultRealm@host.com";
}

/**
 * Returns the password for the given username.
 * This password will be used to generate the response hash to validate against the given response hash.
**/
- (NSString *)passwordForUser:(NSString *)username
{
	// Override me to provide proper password authentication
	// You can configure a password for the entire server, or custom passwords for users and/or resources
	
	// Security Note:
	// A nil password means no access at all. (Such as for user doesn't exist)
	// An empty string password is allowed, and will be treated as any other password. (To support anonymous access)
	
	return nil;
}

/**
 * Generates and returns an authentication nonce.
 * A nonce is a  server-specified string uniquely generated for each 401 response.
 * The default implementation uses a single nonce for each session.
**/
- (NSString *)generateNonce
{
	// We use the Core Foundation UUID class to generate a nonce value for us
	// UUIDs (Universally Unique Identifiers) are 128-bit values guaranteed to be unique.
	CFUUIDRef theUUID = CFUUIDCreate(NULL);
	NSString *newNonce = [NSMakeCollectable(CFUUIDCreateString(NULL, theUUID)) autorelease];
	CFRelease(theUUID);
	
	// We have to remember that the HTTP protocol is stateless
	// Even though with version 1.1 persistent connections are the norm, they are not guaranteed
	// Thus if we generate a nonce for this connection,
	// it should be honored for other connections in the near future
	// 
	// In fact, this is absolutely necessary in order to support QuickTime
	// When QuickTime makes it's initial connection, it will be unauthorized, and will receive a nonce
	// It then disconnects, and creates a new connection with the nonce, and proper authentication
	// If we don't honor the nonce for the second connection, QuickTime will repeat the process and never connect
	
	[recentNonces addObject:newNonce];
	
	[NSTimer scheduledTimerWithTimeInterval:NONCE_TIMEOUT
									 target:[HTTPConnection class]
								   selector:@selector(removeRecentNonce:)
								   userInfo:newNonce
									repeats:NO];
	return newNonce;
}

/**
 * Returns whether or not the user is properly authenticated.
 * Authentication is done using Digest Access Authentication accoring to RFC 2617.
**/
- (BOOL)isAuthenticated
{
	// Extract the authentication information from the Authorization header
	HTTPAuthenticationRequest *auth = [[[HTTPAuthenticationRequest alloc] initWithRequest:request] autorelease];
	
	if([self useDigestAccessAuthentication])
	{
		// Digest Access Authentication
		
		if(![auth isDigest])
		{
			// User didn't send proper digest access authentication credentials
			return NO;
		}
		
		if([auth username] == nil)
		{
			// The client didn't provide a username
			// Most likely they didn't provide any authentication at all
			return NO;
		}
		
		NSString *password = [self passwordForUser:[auth username]];
		if(password == nil)
		{
			// No access allowed (username doesn't exist in system)
			return NO;
		}
		
		NSString *method = [NSMakeCollectable(CFHTTPMessageCopyRequestMethod(request)) autorelease];
		
		NSURL *absoluteUrl = [NSMakeCollectable(CFHTTPMessageCopyRequestURL(request)) autorelease];
		NSString *url = [absoluteUrl relativeString];
		
		if(![url isEqualToString:[auth uri]])
		{
			// Requested URL and Authorization URI do not match
			// This could be a replay attack
			// IE - attacker provides same authentication information, but requests a different resource
			return NO;
		}
		
		// The nonce the client provided will most commonly be stored in our local (cached) nonce variable
		if(![nonce isEqualToString:[auth nonce]])
		{
			// The given nonce may be from another connection
			// We need to search our list of recent nonce strings that have been recently distributed
			if([recentNonces containsObject:[auth nonce]])
			{
				// Store nonce in local (cached) nonce variable to prevent array searches in the future
				[nonce release];
				nonce = [[auth nonce] copy];
				
				// The client has switched to using a different nonce value
				// This may happen if the client tries to get a file in a directory with different credentials.
				// The previous credentials wouldn't work, and the client would receive a 401 error
				// along with a new nonce value. The client then uses this new nonce value and requests the file again.
				// Whatever the case may be, we need to reset lastNC, since that variable is on a per nonce basis.
				lastNC = 0;
			}
			else
			{
				// We have no knowledge of ever distributing such a nonce
				// This could be a replay attack from a previous connection in the past
				return NO;
			}
		}
		
		long authNC = strtol([[auth nc] UTF8String], NULL, 16);
		
		if(authNC <= lastNC)
		{
			// The nc value (nonce count) hasn't been incremented since the last request
			// This could be a replay attack
			return NO;
		}
		lastNC = authNC;
		
		NSString *HA1str = [NSString stringWithFormat:@"%@:%@:%@", [auth username], [auth realm], password];
		NSString *HA2str = [NSString stringWithFormat:@"%@:%@", method, [auth uri]];
		
		NSString *HA1 = [[[HA1str dataUsingEncoding:NSUTF8StringEncoding] md5Digest] hexStringValue];
		
		NSString *HA2 = [[[HA2str dataUsingEncoding:NSUTF8StringEncoding] md5Digest] hexStringValue];
		
		NSString *responseStr = [NSString stringWithFormat:@"%@:%@:%@:%@:%@:%@",
								 HA1, [auth nonce], [auth nc], [auth cnonce], [auth qop], HA2];
		
		NSString *response = [[[responseStr dataUsingEncoding:NSUTF8StringEncoding] md5Digest] hexStringValue];
		
		return [response isEqualToString:[auth response]];
	}
	else
	{
		// Basic Authentication
		
		if(![auth isBasic])
		{
			// User didn't send proper base authentication credentials
			return NO;
		}
		
		// Decode the base 64 encoded credentials
		NSString *base64Credentials = [auth base64Credentials];
		
		NSData *temp = [[base64Credentials dataUsingEncoding:NSUTF8StringEncoding] base64Decoded];
		
		NSString *credentials = [[[NSString alloc] initWithData:temp encoding:NSUTF8StringEncoding] autorelease];
		
		// The credentials should be of the form "username:password"
		// The username is not allowed to contain a colon
		
		NSRange colonRange = [credentials rangeOfString:@":"];
		
		if(colonRange.length == 0)
		{
			// Malformed credentials
			return NO;
		}
		
		NSString *credUsername = [credentials substringToIndex:colonRange.location];
		NSString *credPassword = [credentials substringFromIndex:(colonRange.location + colonRange.length)];
		
		NSString *password = [self passwordForUser:credUsername];
		if(password == nil)
		{
			// No access allowed (username doesn't exist in system)
			return NO;
		}
		
		return [password isEqualToString:credPassword];
	}
}

/**
 * Adds a digest access authentication challenge to the given response.
**/
- (void)addDigestAuthChallenge:(CFHTTPMessageRef)response
{
	NSString *authFormat = @"Digest realm=\"%@\", qop=\"auth\", nonce=\"%@\"";
	NSString *authInfo = [NSString stringWithFormat:authFormat, [self realm], [self generateNonce]];
	
	CFHTTPMessageSetHeaderFieldValue(response, CFSTR("WWW-Authenticate"), (CFStringRef)authInfo);
}

/**
 * Adds a basic authentication challenge to the given response.
**/
- (void)addBasicAuthChallenge:(CFHTTPMessageRef)response
{
	NSString *authFormat = @"Basic realm=\"%@\"";
	NSString *authInfo = [NSString stringWithFormat:authFormat, [self realm]];
	
	CFHTTPMessageSetHeaderFieldValue(response, CFSTR("WWW-Authenticate"), (CFStringRef)authInfo);
}

/**
 * Attempts to parse the given range header into a series of non-overlapping ranges.
 * If successfull, the variables 'ranges' and 'rangeIndex' will be updated, and YES will be returned.
 * Otherwise, NO is returned, and the range request should be ignored.
 **/
- (BOOL)parseRangeRequest:(NSString *)rangeHeader withContentLength:(UInt64)contentLength
{
	// Examples of byte-ranges-specifier values (assuming an entity-body of length 10000):
	// 
	// - The first 500 bytes (byte offsets 0-499, inclusive):  bytes=0-499
	// 
	// - The second 500 bytes (byte offsets 500-999, inclusive): bytes=500-999
	// 
	// - The final 500 bytes (byte offsets 9500-9999, inclusive): bytes=-500
	// 
	// - Or bytes=9500-
	// 
	// - The first and last bytes only (bytes 0 and 9999):  bytes=0-0,-1
	// 
	// - Several legal but not canonical specifications of the second 500 bytes (byte offsets 500-999, inclusive):
	// bytes=500-600,601-999
	// bytes=500-700,601-999
	// 
	
	NSRange eqsignRange = [rangeHeader rangeOfString:@"="];
	
	if(eqsignRange.location == NSNotFound) return NO;
	
	NSUInteger tIndex = eqsignRange.location;
	NSUInteger fIndex = eqsignRange.location + eqsignRange.length;
	
	NSString *rangeType  = [[[rangeHeader substringToIndex:tIndex] mutableCopy] autorelease];
	NSString *rangeValue = [[[rangeHeader substringFromIndex:fIndex] mutableCopy] autorelease];
	
	CFStringTrimWhitespace((CFMutableStringRef)rangeType);
	CFStringTrimWhitespace((CFMutableStringRef)rangeValue);
	
	if([rangeType caseInsensitiveCompare:@"bytes"] != NSOrderedSame) return NO;
	
	NSArray *rangeComponents = [rangeValue componentsSeparatedByString:@","];
	
	if([rangeComponents count] == 0) return NO;
	
	[ranges release];
	ranges = [[NSMutableArray alloc] initWithCapacity:[rangeComponents count]];
	
	rangeIndex = 0;
	
	// Note: We store all range values in the form of NSRange structs, wrapped in NSValue objects.
	// Since NSRange consists of NSUInteger values, the range is limited to 4 gigs on 32-bit architectures (ppc, i386)
	
	NSUInteger i;
	for(i = 0; i < [rangeComponents count]; i++)
	{
		NSString *rangeComponent = [rangeComponents objectAtIndex:i];
		
		NSRange dashRange = [rangeComponent rangeOfString:@"-"];
		
		if(dashRange.location == NSNotFound)
		{
			// We're dealing with an individual byte number
			
			UInt64 byteIndex;
			if(![NSNumber parseString:rangeComponent intoUInt64:&byteIndex]) return NO;
			
			[ranges addObject:[NSValue valueWithDDRange:DDMakeRange(byteIndex, 1)]];
		}
		else
		{
			// We're dealing with a range of bytes
			
			tIndex = dashRange.location;
			fIndex = dashRange.location + dashRange.length;
			
			NSString *r1str = [rangeComponent substringToIndex:tIndex];
			NSString *r2str = [rangeComponent substringFromIndex:fIndex];
			
			UInt64 r1, r2;
			
			BOOL hasR1 = [NSNumber parseString:r1str intoUInt64:&r1];
			BOOL hasR2 = [NSNumber parseString:r2str intoUInt64:&r2];
			
			if(!hasR1)
			{
				// We're dealing with a "-[#]" range
				// 
				// r2 is the number of ending bytes to include in the range
				
				if(!hasR2) return NO;
				if(r2 > contentLength) return NO;
				
				UInt64 startIndex = contentLength - r2;
				
				[ranges addObject:[NSValue valueWithDDRange:DDMakeRange(startIndex, r2)]];
			}
			else if(!hasR2)
			{
				// We're dealing with a "[#]-" range
				// 
				// r1 is the starting index of the range, which goes all the way to the end
				
				if(!hasR1) return NO;
				if(r1 >= contentLength) return NO;
				
				[ranges addObject:[NSValue valueWithDDRange:DDMakeRange(r1, contentLength - r1)]];
			}
			else
			{
				// We're dealing with a normal "[#]-[#]" range
				// 
				// Note: The range is inclusive. So 0-1 has a length of 2 bytes.
				
				if(!hasR1) return NO;
				if(!hasR2) return NO;
				if(r1 > r2) return NO;
				
				[ranges addObject:[NSValue valueWithDDRange:DDMakeRange(r1, r2 - r1 + 1)]];
			}
		}
	}
	
	if([ranges count] == 0) return NO;
	
	for(i = 0; i < [ranges count] - 1; i++)
	{
		DDRange range1 = [[ranges objectAtIndex:i] ddrangeValue];
		
		NSUInteger j;
		for(j = i+1; j < [ranges count]; j++)
		{
			DDRange range2 = [[ranges objectAtIndex:j] ddrangeValue];
			
			DDRange iRange = DDIntersectionRange(range1, range2);
			
			if(iRange.length != 0)
			{
				return NO;
			}
		}
	}
	
	return YES;
}

/**
 * Gets the current date and time, formatted properly (according to RFC) for insertion into an HTTP header.
**/
- (NSString *)dateAsString:(NSDate *)date
{
	// Example: Sun, 06 Nov 1994 08:49:37 GMT
	
	NSDateFormatter *df = [[[NSDateFormatter alloc] init] autorelease];
	[df setFormatterBehavior:NSDateFormatterBehavior10_4];
	[df setTimeZone:[NSTimeZone timeZoneWithAbbreviation:@"GMT"]];
	[df setDateFormat:@"EEE, dd MMM y HH:mm:ss 'GMT'"];
	
	// For some reason, using zzz in the format string produces GMT+00:00
	
	return [df stringFromDate:date];
}

/**
 * This method is called after a full HTTP request has been received.
 * The current request is in the CFHTTPMessage request variable.
**/
- (void)replyToHTTPRequest
{
	// Check the HTTP version - if it's anything but HTTP version 1.1, we don't support it
	NSString *version = [NSMakeCollectable(CFHTTPMessageCopyVersion(request)) autorelease];
	if(!version || ![version isEqualToString:(NSString *)kCFHTTPVersion1_1])
	{
		[self handleVersionNotSupported:version];
		return;
	}
	
	// Extract the method
	NSString *method = [NSMakeCollectable(CFHTTPMessageCopyRequestMethod(request)) autorelease];
	
	// Note: We already checked to ensure the method was supported in onSocket:didReadData:withTag:
	
	// Extract requested URI
	NSURL *uri = [NSMakeCollectable(CFHTTPMessageCopyRequestURL(request)) autorelease];
	
	// Check Authentication (if needed)
	// If not properly authenticated for resource, issue Unauthorized response
	if([self isPasswordProtected:[uri relativeString]] && ![self isAuthenticated])
	{
		[self handleAuthenticationFailed];
		return;
	}
	
	// Respond properly to HTTP 'GET' and 'HEAD' commands
	httpResponse = [[self httpResponseForMethod:method URI:[uri relativeString]] retain];
	
	UInt64 contentLength = httpResponse ? [httpResponse contentLength] : 0;
	
	if(contentLength == 0)
	{
		[self handleResourceNotFound];
		
		[httpResponse release];
		httpResponse = nil;
		
		return;
    }
	
	// Check for specific range request
	NSString *rangeHeader = [NSMakeCollectable(CFHTTPMessageCopyHeaderFieldValue(request, CFSTR("Range"))) autorelease];
	
	BOOL isRangeRequest = NO;
	
	if(rangeHeader)
	{
		if([self parseRangeRequest:rangeHeader withContentLength:contentLength])
		{
			isRangeRequest = YES;
		}
	}
	
	CFHTTPMessageRef response;
	
	if(!isRangeRequest)
	{
		// Status Code 200 - OK
		response = CFHTTPMessageCreateResponse(kCFAllocatorDefault, 200, NULL, kCFHTTPVersion1_1);
		
		NSString *contentLengthStr = [NSString stringWithFormat:@"%qu", contentLength];
		CFHTTPMessageSetHeaderFieldValue(response, CFSTR("Content-Length"), (CFStringRef)contentLengthStr);
	}
	else
	{
		if([ranges count] == 1)
		{
			response = [self prepareUniRangeResponse:contentLength];
		}
		else
		{
			response = [self prepareMultiRangeResponse:contentLength];
		}
	}
    
	// If they issue a 'HEAD' command, we don't have to include the file
	// If they issue a 'GET' command, we need to include the file
	if([method isEqual:@"HEAD"])
	{
		NSData *responseData = [self preprocessResponse:response];
		[asyncSocket writeData:responseData withTimeout:WRITE_HEAD_TIMEOUT tag:HTTP_RESPONSE];
	}
	else
	{
		// Write the header response
		NSData *responseData = [self preprocessResponse:response];
		[asyncSocket writeData:responseData withTimeout:WRITE_HEAD_TIMEOUT tag:HTTP_PARTIAL_RESPONSE_HEADER];
		
		// Now we need to send the body of the response
		if(!isRangeRequest)
		{
			// Regular request
			NSData *data = [httpResponse readDataOfLength:READ_CHUNKSIZE];
			
			[asyncSocket writeData:data withTimeout:WRITE_BODY_TIMEOUT tag:HTTP_PARTIAL_RESPONSE_BODY];
		}
		else
		{
			// Client specified a byte range in request
			
			if([ranges count] == 1)
			{
				// Client is requesting a single range
				DDRange range = [[ranges objectAtIndex:0] ddrangeValue];
				
				[httpResponse setOffset:range.location];
				
				unsigned int bytesToRead = range.length < READ_CHUNKSIZE ? range.length : READ_CHUNKSIZE;
				
				NSData *data = [httpResponse readDataOfLength:bytesToRead];
				
				[asyncSocket writeData:data withTimeout:WRITE_BODY_TIMEOUT tag:HTTP_PARTIAL_RANGE_RESPONSE_BODY];
			}
			else
			{
				// Client is requesting multiple ranges
				// We have to send each range using multipart/byteranges
				
				// Write range header
				NSData *rangeHeader = [ranges_headers objectAtIndex:0];
				[asyncSocket writeData:rangeHeader withTimeout:WRITE_HEAD_TIMEOUT tag:HTTP_PARTIAL_RESPONSE_HEADER];
				
				// Start writing range body
				DDRange range = [[ranges objectAtIndex:0] ddrangeValue];
				
				[httpResponse setOffset:range.location];
				
				unsigned int bytesToRead = range.length < READ_CHUNKSIZE ? range.length : READ_CHUNKSIZE;
				
				NSData *data = [httpResponse readDataOfLength:bytesToRead];
				
				[asyncSocket writeData:data withTimeout:WRITE_BODY_TIMEOUT tag:HTTP_PARTIAL_RANGES_RESPONSE_BODY];
			}
		}
	}
	
	CFRelease(response);
}

/**
 * Prepares a single-range response.
 * 
 * Note: The returned CFHTTPMessageRef is owned by the sender, who is responsible for releasing it.
**/
- (CFHTTPMessageRef)prepareUniRangeResponse:(UInt64)contentLength
{
	// Status Code 206 - Partial Content
	CFHTTPMessageRef response = CFHTTPMessageCreateResponse(kCFAllocatorDefault, 206, NULL, kCFHTTPVersion1_1);
	
	DDRange range = [[ranges objectAtIndex:0] ddrangeValue];
	
	NSString *contentLengthStr = [NSString stringWithFormat:@"%qu", range.length];
	CFHTTPMessageSetHeaderFieldValue(response, CFSTR("Content-Length"), (CFStringRef)contentLengthStr);
	
	NSString *rangeStr = [NSString stringWithFormat:@"%qu-%qu", range.location, DDMaxRange(range) - 1];
	NSString *contentRangeStr = [NSString stringWithFormat:@"bytes %@/%qu", rangeStr, contentLength];
	CFHTTPMessageSetHeaderFieldValue(response, CFSTR("Content-Range"), (CFStringRef)contentRangeStr);
	
	return response;
}

/**
 * Prepares a multi-range response.
 * 
 * Note: The returned CFHTTPMessageRef is owned by the sender, who is responsible for releasing it.
**/
- (CFHTTPMessageRef)prepareMultiRangeResponse:(UInt64)contentLength
{
	// Status Code 206 - Partial Content
	CFHTTPMessageRef response = CFHTTPMessageCreateResponse(kCFAllocatorDefault, 206, NULL, kCFHTTPVersion1_1);
	
	// We have to send each range using multipart/byteranges
	// So each byterange has to be prefix'd and suffix'd with the boundry
	// Example:
	// 
	// HTTP/1.1 206 Partial Content
	// Content-Length: 220
	// Content-Type: multipart/byteranges; boundary=4554d24e986f76dd6
	// 
	// 
	// --4554d24e986f76dd6
	// Content-range: bytes 0-25/4025
	// 
	// [...]
	// --4554d24e986f76dd6
	// Content-range: bytes 3975-4024/4025
	// 
	// [...]
	// --4554d24e986f76dd6--
	
	ranges_headers = [[NSMutableArray alloc] initWithCapacity:[ranges count]];
	
	CFUUIDRef theUUID = CFUUIDCreate(NULL);
	ranges_boundry = NSMakeCollectable(CFUUIDCreateString(NULL, theUUID));
	CFRelease(theUUID);
	
	NSString *startingBoundryStr = [NSString stringWithFormat:@"\r\n--%@\r\n", ranges_boundry];
	NSString *endingBoundryStr = [NSString stringWithFormat:@"\r\n--%@--\r\n", ranges_boundry];
	
	UInt64 actualContentLength = 0;
	
	unsigned i;
	for(i = 0; i < [ranges count]; i++)
	{
		DDRange range = [[ranges objectAtIndex:i] ddrangeValue];
		
		NSString *rangeStr = [NSString stringWithFormat:@"%qu-%qu", range.location, DDMaxRange(range) - 1];
		NSString *contentRangeVal = [NSString stringWithFormat:@"bytes %@/%qu", rangeStr, contentLength];
		NSString *contentRangeStr = [NSString stringWithFormat:@"Content-Range: %@\r\n\r\n", contentRangeVal];
		
		NSString *fullHeader = [startingBoundryStr stringByAppendingString:contentRangeStr];
		NSData *fullHeaderData = [fullHeader dataUsingEncoding:NSUTF8StringEncoding];
		
		[ranges_headers addObject:fullHeaderData];
		
		actualContentLength += [fullHeaderData length];
		actualContentLength += range.length;
	}
	
	NSData *endingBoundryData = [endingBoundryStr dataUsingEncoding:NSUTF8StringEncoding];
	
	actualContentLength += [endingBoundryData length];
	
	NSString *contentLengthStr = [NSString stringWithFormat:@"%qu", actualContentLength];
	CFHTTPMessageSetHeaderFieldValue(response, CFSTR("Content-Length"), (CFStringRef)contentLengthStr);
	
	NSString *contentTypeStr = [NSString stringWithFormat:@"multipart/byteranges; boundary=%@", ranges_boundry];
	CFHTTPMessageSetHeaderFieldValue(response, CFSTR("Content-Type"), (CFStringRef)contentTypeStr);
	
	return response;
}

/**
 * Converts relative URI path into full file-system path.
**/
- (NSString *)filePathForURI:(NSString *)path
{
	// Override me to perform custom path mapping.
	// For example you may want to use a default file other than index.html, or perhaps support multiple types.
	
	// If there is no configured documentRoot, then it makes no sense to try to return anything
	if(![server documentRoot]) return nil;
	
	// Convert path to a relative path.
	// This essentially means trimming beginning '/' characters.
	// Beware of a bug in the Cocoa framework:
	// 
	// [NSURL URLWithString:@"/foo" relativeToURL:baseURL]       == @"/baseURL/foo"
	// [NSURL URLWithString:@"/foo%20bar" relativeToURL:baseURL] == @"/foo bar"
	// [NSURL URLWithString:@"/foo" relativeToURL:baseURL]       == @"/foo"
	
	NSString *relativePath = path;
	
	while([relativePath hasPrefix:@"/"] && [relativePath length] > 1)
	{
		relativePath = [relativePath substringFromIndex:1];
	}
	
	NSURL *url;
	
	if([relativePath hasSuffix:@"/"])
	{
		NSString *completedRelativePath = [relativePath stringByAppendingString:@"index.html"];
		url = [NSURL URLWithString:completedRelativePath relativeToURL:[server documentRoot]];
	}
	else
	{
		url = [NSURL URLWithString:relativePath relativeToURL:[server documentRoot]];
	}
	
	// Watch out for sneaky requests with ".." in the path
	// For example, the following request: "../Documents/TopSecret.doc"
	if(![[url path] hasPrefix:[[server documentRoot] path]]) return nil;
	
	return [[url path] stringByStandardizingPath];
}

/**
 * This method is called to get a response for a request.
 * You may return any object that adopts the HTTPResponse protocol.
 * The HTTPServer comes with two such classes: HTTPFileResponse and HTTPDataResponse.
 * HTTPFileResponse is a wrapper for an NSFileHandle object, and is the preferred way to send a file response.
 * HTTPDataResponse is a wrapper for an NSData object, and may be used to send a custom response.
**/
- (NSObject<HTTPResponse> *)httpResponseForMethod:(NSString *)method URI:(NSString *)path
{
	// Override me to provide custom responses.
	
	NSString *filePath = [self filePathForURI:path];
	
	if([[NSFileManager defaultManager] fileExistsAtPath:filePath])
	{
		return [[[HTTPFileResponse alloc] initWithFilePath:filePath] autorelease];
	}
	
	return nil;
}

/**
 * This method is called after receiving all HTTP headers, but before reading any of the request body.
**/
- (void)prepareForBodyWithSize:(UInt64)contentLength
{
	// Override me to allocate buffers, file handles, etc.
}

/**
 * This method is called to handle data read from a POST / PUT.
 * The given data is part of the request body.
**/
- (void)processDataChunk:(NSData *)postDataChunk
{
	// Override me to do something useful with a POST / PUT.
	// If the post is small, such as a simple form, you may want to simply append the data to the request.
	// If the post is big, such as a file upload, you may want to store the file to disk.
	// 
	// Remember: In order to support LARGE POST uploads, the data is read in chunks.
	// This prevents a 50 MB upload from being stored in RAM.
	// The size of the chunks are limited by the POST_CHUNKSIZE definition.
	// Therefore, this method may be called multiple times for the same POST request.
}

/**
 * Called if the HTML version is other than what is supported
**/
- (void)handleVersionNotSupported:(NSString *)version
{
	// Override me for custom error handling of unspupported http version responses
	// If you simply want to add a few extra header fields, see the preprocessErrorResponse: method.
	// You can also use preprocessErrorResponse: to add an optional HTML body.
	
	//NSLog(@"HTTP Server: Error 505 - Version Not Supported: %@", version);
	
	CFHTTPMessageRef response = CFHTTPMessageCreateResponse(kCFAllocatorDefault, 505, NULL, kCFHTTPVersion1_1);
	CFHTTPMessageSetHeaderFieldValue(response, CFSTR("Content-Length"), CFSTR("0"));
    
	NSData *responseData = [self preprocessErrorResponse:response];
	[asyncSocket writeData:responseData withTimeout:WRITE_ERROR_TIMEOUT tag:HTTP_RESPONSE];
	
	CFRelease(response);
}

/**
 * Called if the authentication information was required and absent, or if authentication failed.
**/
- (void)handleAuthenticationFailed
{
	// Override me for custom handling of authentication challenges
	// If you simply want to add a few extra header fields, see the preprocessErrorResponse: method.
	// You can also use preprocessErrorResponse: to add an optional HTML body.
	
	//NSLog(@"HTTP Server: Error 401 - Unauthorized");
		
	// Status Code 401 - Unauthorized
	CFHTTPMessageRef response = CFHTTPMessageCreateResponse(kCFAllocatorDefault, 401, NULL, kCFHTTPVersion1_1);
	CFHTTPMessageSetHeaderFieldValue(response, CFSTR("Content-Length"), CFSTR("0"));
	
	if([self useDigestAccessAuthentication])
	{
		[self addDigestAuthChallenge:response];
	}
	else
	{
		[self addBasicAuthChallenge:response];
	}
	
	NSData *responseData = [self preprocessErrorResponse:response];
	[asyncSocket writeData:responseData withTimeout:WRITE_ERROR_TIMEOUT tag:HTTP_RESPONSE];
	
	CFRelease(response);
}

/**
 * Called if we receive some sort of malformed HTTP request.
 * The data parameter is the invalid HTTP header line, including CRLF, as read from AsyncSocket.
 * The data parameter may also be nil if the request as a whole was invalid, such as a POST with no Content-Length.
**/
- (void)handleInvalidRequest:(NSData *)data
{
	// Override me for custom error handling of invalid HTTP requests
	// If you simply want to add a few extra header fields, see the preprocessErrorResponse: method.
	// You can also use preprocessErrorResponse: to add an optional HTML body.
	
	//NSLog(@"HTTP Server: Error 400 - Bad Request");
	
	// Status Code 400 - Bad Request
	CFHTTPMessageRef response = CFHTTPMessageCreateResponse(kCFAllocatorDefault, 400, NULL, kCFHTTPVersion1_1);
	CFHTTPMessageSetHeaderFieldValue(response, CFSTR("Content-Length"), CFSTR("0"));
	
	NSData *responseData = [self preprocessErrorResponse:response];
	[asyncSocket writeData:responseData withTimeout:WRITE_ERROR_TIMEOUT tag:HTTP_FINAL_RESPONSE];
	
	CFRelease(response);
}

/**
 * Called if we receive a HTTP request with a method other than GET or HEAD.
**/
- (void)handleUnknownMethod:(NSString *)method
{
	// Override me to add support for methods other than GET and HEAD
	// If you simply want to add a few extra header fields, see the preprocessErrorResponse: method.
	// You can also use preprocessErrorResponse: to add an optional HTML body.
	
	//NSLog(@"HTTP Server: Error 405 - Method Not Allowed: %@", method);
	
	// Status code 405 - Method Not Allowed
    CFHTTPMessageRef response = CFHTTPMessageCreateResponse(kCFAllocatorDefault, 405, NULL, kCFHTTPVersion1_1);
	CFHTTPMessageSetHeaderFieldValue(response, CFSTR("Content-Length"), CFSTR("0"));
	
	NSData *responseData = [self preprocessErrorResponse:response];
	[asyncSocket writeData:responseData withTimeout:WRITE_ERROR_TIMEOUT tag:HTTP_FINAL_RESPONSE];
    
	CFRelease(response);
	
	// Note: We used the HTTP_FINAL_RESPONSE tag to disconnect after the response is sent.
	// We do this because the method may include an http body.
	// Since we can't be sure, we should close the connection.
}

- (void)handleResourceNotFound
{
	// Override me for custom error handling of 404 not found responses
	// If you simply want to add a few extra header fields, see the preprocessErrorResponse: method.
	// You can also use preprocessErrorResponse: to add an optional HTML body.
	
	//NSLog(@"HTTP Server: Error 404 - Not Found");
	
	// Status Code 404 - Not Found
	CFHTTPMessageRef response = CFHTTPMessageCreateResponse(kCFAllocatorDefault, 404, NULL, kCFHTTPVersion1_1);
	CFHTTPMessageSetHeaderFieldValue(response, CFSTR("Content-Length"), CFSTR("0"));
	
	NSData *responseData = [self preprocessErrorResponse:response];
	[asyncSocket writeData:responseData withTimeout:WRITE_ERROR_TIMEOUT tag:HTTP_RESPONSE];
	
	CFRelease(response);
}

/**
 * This method is called immediately prior to sending the response headers.
 * This method adds standard header fields, and then converts the response to an NSData object.
**/
- (NSData *)preprocessResponse:(CFHTTPMessageRef)response
{
	// Override me to customize the response headers
	// You'll likely want to add your own custom headers, and then return [super preprocessResponse:response]
	
	// Add standard headers
	NSString *now = [self dateAsString:[NSDate date]];
	CFHTTPMessageSetHeaderFieldValue(response, CFSTR("Date"), (CFStringRef)now);
	
	// Add server capability headers
	CFHTTPMessageSetHeaderFieldValue(response, CFSTR("Accept-Ranges"), CFSTR("bytes"));
	
	// Add optional response headers
	if([httpResponse respondsToSelector:@selector(httpHeaders)])
	{
		NSDictionary *responseHeaders = [httpResponse httpHeaders];
		
		NSEnumerator *keyEnumerator = [responseHeaders keyEnumerator];
		NSString *key;
		
		while(key = [keyEnumerator nextObject])
		{
			NSString *value = [responseHeaders objectForKey:key];
			
			CFHTTPMessageSetHeaderFieldValue(response, (CFStringRef)key, (CFStringRef)value);
		}
	}
	
	NSData *result = NSMakeCollectable(CFHTTPMessageCopySerializedMessage(response));
	return [result autorelease];
}

/**
 * This method is called immediately prior to sending the response headers (for an error).
 * This method adds standard header fields, and then converts the response to an NSData object.
**/
- (NSData *)preprocessErrorResponse:(CFHTTPMessageRef)response;
{
	// Override me to customize the error response headers
	// You'll likely want to add your own custom headers, and then return [super preprocessErrorResponse:response]
	// 
	// Notes:
	// You can use CFHTTPMessageGetResponseStatusCode(response) to get the type of error.
	// You can use CFHTTPMessageSetBody() to add an optional HTML body.
	// If you add a body, don't forget to update the Content-Length.
	// 
	// if(CFHTTPMessageGetResponseStatusCode(response) == 404)
	// {
	//     NSString *msg = @"<html><body>Error 404 - Not Found</body></html>";
	//     NSData *msgData = [msg dataUsingEncoding:NSUTF8StringEncoding];
	//     
	//     CFHTTPMessageSetBody(response, (CFDataRef)msgData);
	//     
	//     NSString *contentLengthStr = [NSString stringWithFormat:@"%u", (unsigned)[msgData length]];
	//     CFHTTPMessageSetHeaderFieldValue(response, CFSTR("Content-Length"), (CFStringRef)contentLengthStr);
	// }
	
	// Add standard headers
	NSString *now = [self dateAsString:[NSDate date]];
	CFHTTPMessageSetHeaderFieldValue(response, CFSTR("Date"), (CFStringRef)now);
	
	// Add server capability headers
	CFHTTPMessageSetHeaderFieldValue(response, CFSTR("Accept-Ranges"), CFSTR("bytes"));
	
	// Add optional response headers
	if([httpResponse respondsToSelector:@selector(httpHeaders)])
	{
		NSDictionary *responseHeaders = [httpResponse httpHeaders];
		
		NSEnumerator *keyEnumerator = [responseHeaders keyEnumerator];
		NSString *key;
		
		while(key = [keyEnumerator nextObject])
		{
			NSString *value = [responseHeaders objectForKey:key];
			
			CFHTTPMessageSetHeaderFieldValue(response, (CFStringRef)key, (CFStringRef)value);
		}
	}
	
	NSData *result = NSMakeCollectable(CFHTTPMessageCopySerializedMessage(response));
	return [result autorelease];
}

- (void)die
{
	// Post notification of dead connection
	// This will allow our server to release us from its array of connections
	[[NSNotificationCenter defaultCenter] postNotificationName:HTTPConnectionDidDieNotification object:self];
}

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
#pragma mark AsyncSocket Delegate Methods:
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

/**
 * This method is called immediately prior to opening up the stream.
 * This is the time to manually configure the stream if necessary.
**/
- (BOOL)onSocketWillConnect:(AsyncSocket *)sock
{
	if([self isSecureServer])
	{
		NSArray *certificates = [self sslIdentityAndCertificates];
		
		if([certificates count] > 0)
		{
			//NSLog(@"Securing connection...");
			
			// All connections are assumed to be secure. Only secure connections are allowed on this server.
			NSMutableDictionary *settings = [NSMutableDictionary dictionaryWithCapacity:3];
			
			// Configure this connection as the server
			CFDictionaryAddValue((CFMutableDictionaryRef)settings,
								 kCFStreamSSLIsServer, kCFBooleanTrue);
			
			CFDictionaryAddValue((CFMutableDictionaryRef)settings,
								 kCFStreamSSLCertificates, (CFArrayRef)certificates);
			
			// Configure this connection to use the highest possible SSL level
			CFDictionaryAddValue((CFMutableDictionaryRef)settings,
								 kCFStreamSSLLevel, kCFStreamSocketSecurityLevelNegotiatedSSL);
			
			CFReadStreamSetProperty([asyncSocket getCFReadStream],
									kCFStreamPropertySSLSettings, (CFDictionaryRef)settings);
			CFWriteStreamSetProperty([asyncSocket getCFWriteStream],
									 kCFStreamPropertySSLSettings, (CFDictionaryRef)settings);
		}
	}
	return YES;
}

/**
 * This method is called after the socket has been fully opened.
 * It is called on the proper thread/runloop that HTTPServer configured our socket to run on.
**/
- (void)onSocket:(AsyncSocket *)sock didConnectToHost:(NSString *)host port:(UInt16)port
{
	// The socket is up and ready, and this method is called on the socket's corresponding thread.
	// We can now start reading the HTTP requests...
	[asyncSocket readDataToData:[AsyncSocket CRLFData]
					withTimeout:READ_TIMEOUT
					  maxLength:LIMIT_MAX_HEADER_LINE_LENGTH
							tag:HTTP_REQUEST_HEADER];
}

/**
 * This method is called after the socket has successfully read data from the stream.
 * Remember that this method will only be called after the socket reaches a CRLF, or after it's read the proper length.
**/
- (void)onSocket:(AsyncSocket *)sock didReadData:(NSData*)data withTag:(long)tag
{
	if(tag == HTTP_REQUEST_HEADER)
	{
		// Append the header line to the http message
		BOOL result = CFHTTPMessageAppendBytes(request, [data bytes], [data length]);
		if(!result)
		{
			// We have a received a malformed request
			[self handleInvalidRequest:data];
		}
		else if(!CFHTTPMessageIsHeaderComplete(request))
		{
			// We don't have a complete header yet
			// That is, we haven't yet received a CRLF on a line by itself, indicating the end of the header
			if(++numHeaderLines > LIMIT_MAX_HEADER_LINES)
			{
				// Reached the maximum amount of header lines in a single HTTP request
				// This could be an attempted DOS attack
				[asyncSocket disconnect];
			}
			else
			{
				[asyncSocket readDataToData:[AsyncSocket CRLFData]
								withTimeout:READ_TIMEOUT
								  maxLength:LIMIT_MAX_HEADER_LINE_LENGTH
										tag:HTTP_REQUEST_HEADER];
			}
		}
		else
		{
			// We have an entire HTTP request header from the client
			
			// Extract the method (such as GET, HEAD, POST, etc)
			NSString *method = [NSMakeCollectable(CFHTTPMessageCopyRequestMethod(request)) autorelease];
			
			// Extract the uri (such as "/index.html")
			NSURL *uri = [NSMakeCollectable(CFHTTPMessageCopyRequestURL(request)) autorelease];
			
			// Check for a Content-Length field
			NSString *contentLength =
			    [NSMakeCollectable(CFHTTPMessageCopyHeaderFieldValue(request, CFSTR("Content-Length"))) autorelease];
			
			// Content-Length MUST be present for upload methods (such as POST or PUT)
			// and MUST NOT be present for other methods.
			BOOL expectsUpload = [method isEqualToString:@"POST"] || [method isEqualToString:@"PUT"];
			
			if(expectsUpload)
			{
				if(contentLength == nil)
				{
					// Received POST/PUT with no specified Content-Length
					[self handleInvalidRequest:nil];
					return;
				}
				
				if(![NSNumber parseString:(NSString *)contentLength intoUInt64:&requestContentLength])
				{
					// Unable to parse Content-Length header into a valid number
					[self handleInvalidRequest:nil];
					return;
				}
			}
			else
			{
				if(contentLength != nil)
				{
					// Received Content-Length header for method not expecting an upload
					[self handleInvalidRequest:nil];
					return;
				}
				
				requestContentLength = 0;
				requestContentLengthReceived = 0;
			}
			
			// Check to make sure the given method is supported
			if(![self supportsMethod:method atPath:[uri relativeString]])
			{
				// The method is unsupported - either in general, or for this specific request
				// Send a 405 - Method not allowed response
				[self handleUnknownMethod:method];
				return;
			}
			
			if(expectsUpload)
			{
				// Reset the total amount of data received for the upload
				requestContentLengthReceived = 0;
				
				// Prepare for the upload
				[self prepareForBodyWithSize:requestContentLength];
				
				// Start reading the request body
				uint bytesToRead = requestContentLength < POST_CHUNKSIZE ? requestContentLength : POST_CHUNKSIZE;
				
				[asyncSocket readDataToLength:bytesToRead withTimeout:READ_TIMEOUT tag:HTTP_REQUEST_BODY];
			}
			else
			{
				// Now we need to reply to the request
				[self replyToHTTPRequest];
			}
		}
	}
	else
	{
		// Handle a chunk of data from the POST body
		
		requestContentLengthReceived += [data length];
		[self processDataChunk:data];
		
		if(requestContentLengthReceived < requestContentLength)
		{
			// We're not done reading the post body yet...
			UInt64 bytesLeft = requestContentLength - requestContentLengthReceived;
			
			uint bytesToRead = bytesLeft < POST_CHUNKSIZE ? bytesLeft : POST_CHUNKSIZE;
			
			[asyncSocket readDataToLength:bytesToRead withTimeout:READ_TIMEOUT tag:HTTP_REQUEST_BODY];
		}
		else
		{
			// Now we need to reply to the request
			[self replyToHTTPRequest];
		}
	}
}

/**
 * This method is called after the socket has successfully written data to the stream.
 * Remember that this method will be called after a complete response to a request has been written.
**/
- (void)onSocket:(AsyncSocket *)sock didWriteDataWithTag:(long)tag
{
	BOOL doneSendingResponse = NO;
	
	if(tag == HTTP_PARTIAL_RESPONSE_BODY)
	{
		// We only wrote a part of the http response - there may be more.
		NSData *data = [httpResponse readDataOfLength:READ_CHUNKSIZE];
		
		if([data length] > 0)
		{
			[asyncSocket writeData:data withTimeout:WRITE_BODY_TIMEOUT tag:tag];
		}
		else
		{
			doneSendingResponse = YES;
		}
	}
	else if(tag == HTTP_PARTIAL_RANGE_RESPONSE_BODY)
	{
		// We only wrote a part of the range - there may be more.
		DDRange range = [[ranges objectAtIndex:0] ddrangeValue];
		
		UInt64 offset = [httpResponse offset];
		UInt64 bytesRead = offset - range.location;
		UInt64 bytesLeft = range.length - bytesRead;
		
		if(bytesLeft > 0)
		{
			unsigned int bytesToRead = bytesLeft < READ_CHUNKSIZE ? bytesLeft : READ_CHUNKSIZE;
			
			NSData *data = [httpResponse readDataOfLength:bytesToRead];
			
			[asyncSocket writeData:data withTimeout:WRITE_BODY_TIMEOUT tag:tag];
		}
		else
		{
			doneSendingResponse = YES;
		}
	}
	else if(tag == HTTP_PARTIAL_RANGES_RESPONSE_BODY)
	{
		// We only wrote part of the range - there may be more.
		// Plus, there may be more ranges.
		DDRange range = [[ranges objectAtIndex:rangeIndex] ddrangeValue];
		
		UInt64 offset = [httpResponse offset];
		UInt64 bytesRead = offset - range.location;
		UInt64 bytesLeft = range.length - bytesRead;
		
		if(bytesLeft > 0)
		{
			unsigned int bytesToRead = bytesLeft < READ_CHUNKSIZE ? bytesLeft : READ_CHUNKSIZE;
			
			NSData *data = [httpResponse readDataOfLength:bytesToRead];
			
			[asyncSocket writeData:data withTimeout:WRITE_BODY_TIMEOUT tag:tag];
		}
		else
		{
			if(++rangeIndex < [ranges count])
			{
				// Write range header
				NSData *rangeHeader = [ranges_headers objectAtIndex:rangeIndex];
				[asyncSocket writeData:rangeHeader withTimeout:WRITE_HEAD_TIMEOUT tag:HTTP_PARTIAL_RESPONSE_HEADER];
				
				// Start writing range body
				range = [[ranges objectAtIndex:rangeIndex] ddrangeValue];
				
				[httpResponse setOffset:range.location];
				
				unsigned int bytesToRead = range.length < READ_CHUNKSIZE ? range.length : READ_CHUNKSIZE;
				
				NSData *data = [httpResponse readDataOfLength:bytesToRead];
				
				[asyncSocket writeData:data withTimeout:WRITE_BODY_TIMEOUT tag:tag];
			}
			else
			{
				// We're not done yet - we still have to send the closing boundry tag
				NSString *endingBoundryStr = [NSString stringWithFormat:@"\r\n--%@--\r\n", ranges_boundry];
				NSData *endingBoundryData = [endingBoundryStr dataUsingEncoding:NSUTF8StringEncoding];
				
				[asyncSocket writeData:endingBoundryData withTimeout:WRITE_HEAD_TIMEOUT tag:HTTP_RESPONSE];
			}
		}
	}
	else if(tag == HTTP_RESPONSE || tag == HTTP_FINAL_RESPONSE)
	{
		doneSendingResponse = YES;
	}
	
	if(doneSendingResponse)
	{
		if(tag == HTTP_FINAL_RESPONSE)
		{
			// Terminate the connection
			[asyncSocket disconnect];
		}
		else
		{
			// Cleanup after the last request
			// And start listening for the next request
			
			// Release any resources we no longer need
			[httpResponse release];
			httpResponse = nil;
			
			[ranges release];
			[ranges_headers release];
			[ranges_boundry release];
			ranges = nil;
			ranges_headers = nil;
			ranges_boundry = nil;
			
			// Release the old request, and create a new one
			if(request) CFRelease(request);
			request = CFHTTPMessageCreateEmpty(kCFAllocatorDefault, YES);
			
			numHeaderLines = 0;
			
			// And start listening for more requests
			[asyncSocket readDataToData:[AsyncSocket CRLFData]
							withTimeout:READ_TIMEOUT
							  maxLength:LIMIT_MAX_HEADER_LINE_LENGTH
									tag:HTTP_REQUEST_HEADER];
		}
	}
}

/**
 * This message is sent:
 *  - if there is an connection, time out, or other i/o error.
 *  - if the remote socket cleanly disconnects.
 *  - before the local socket is disconnected.
**/
- (void)onSocket:(AsyncSocket *)sock willDisconnectWithError:(NSError *)err
{
//	NSLog(@"HTTPConnection: onSocket:willDisconnectWithError: %@", err);
}

/**
 * Sent after the socket has been disconnected.
**/
- (void)onSocketDidDisconnect:(AsyncSocket *)sock
{
	[self die];
}

@end