kCFHostErrorHostNotFound = 1,

kCFHostErrorUnknown = 2, // Query the kCFGetAddrInfoFailureKey to get the value returned from getaddrinfo; lookup in netdb.h

// SOCKS errors; in all cases you may query kCFSOCKSStatusCodeKey to recover the status code returned by the server

kCFSOCKSErrorUnknownClientVersion = 100,

kCFSOCKSErrorUnsupportedServerVersion = 101, // Query the kCFSOCKSVersionKey to find the version requested by the server

// SOCKS4-specific errors

kCFSOCKS4ErrorRequestFailed = 110,  // request rejected or failed by the server

kCFSOCKS4ErrorIdentdFailed = 111,  // request rejected because SOCKS server cannot connect to identd on the client

kCFSOCKS4ErrorIdConflict = 112,  // request rejected because the client program and identd report different user-ids

kCFSOCKS4ErrorUnknownStatusCode = 113,

// SOCKS5-specific errors

kCFSOCKS5ErrorBadState = 120,

kCFSOCKS5ErrorBadResponseAddr = 121,

kCFSOCKS5ErrorBadCredentials = 122,

kCFSOCKS5ErrorUnsupportedNegotiationMethod = 123, // query kCFSOCKSNegotiationMethodKey to find the method requested

kCFSOCKS5ErrorNoAcceptableMethod = 124,

// FTP errors; query the kCFFTPStatusCodeKey to get the status code returned by the server

kCFFTPErrorUnexpectedStatusCode = 200,

// HTTP errors

kCFErrorHTTPAuthenticationTypeUnsupported = 300,

kCFErrorHTTPBadCredentials = 301,

kCFErrorHTTPConnectionLost = 302,

kCFErrorHTTPParseFailure = 303,

kCFErrorHTTPRedirectionLoopDetected = 304,

kCFErrorHTTPBadURL = 305,

kCFErrorHTTPProxyConnectionFailure = 306,

kCFErrorHTTPBadProxyCredentials = 307,

kCFErrorPACFileError = 308,

kCFErrorPACFileAuth = 309,

kCFErrorHTTPSProxyConnectionFailure = 310,

kCFStreamErrorHTTPSProxyFailureUnexpectedResponseToCONNECTMethod = 311,

// Error codes for CFURLConnection and CFURLProtocol

kCFURLErrorBackgroundSessionInUseByAnotherProcess = -996,

kCFURLErrorBackgroundSessionWasDisconnected = -997,

kCFURLErrorUnknown = -998,

kCFURLErrorCancelled = -999,

kCFURLErrorBadURL = -1000,

kCFURLErrorTimedOut = -1001,

kCFURLErrorUnsupportedURL = -1002,

kCFURLErrorCannotFindHost = -1003,

kCFURLErrorCannotConnectToHost = -1004,

kCFURLErrorNetworkConnectionLost = -1005,

kCFURLErrorDNSLookupFailed = -1006,

kCFURLErrorHTTPTooManyRedirects = -1007,

kCFURLErrorResourceUnavailable = -1008,

kCFURLErrorNotConnectedToInternet = -1009,

kCFURLErrorRedirectToNonExistentLocation = -1010,

kCFURLErrorBadServerResponse = -1011,

kCFURLErrorUserCancelledAuthentication = -1012,

kCFURLErrorUserAuthenticationRequired = -1013,

kCFURLErrorZeroByteResource = -1014,

kCFURLErrorCannotDecodeRawData = -1015,

kCFURLErrorCannotDecodeContentData = -1016,

kCFURLErrorCannotParseResponse = -1017,

kCFURLErrorInternationalRoamingOff = -1018,

kCFURLErrorCallIsActive = -1019,

kCFURLErrorDataNotAllowed = -1020,

kCFURLErrorRequestBodyStreamExhausted = -1021,

kCFURLErrorAppTransportSecurityRequiresSecureConnection = -1022,

kCFURLErrorFileDoesNotExist = -1100,

kCFURLErrorFileIsDirectory = -1101,

kCFURLErrorNoPermissionsToReadFile = -1102,

kCFURLErrorDataLengthExceedsMaximum = -1103,

// SSL errors

kCFURLErrorSecureConnectionFailed = -1200,

kCFURLErrorServerCertificateHasBadDate = -1201,

kCFURLErrorServerCertificateUntrusted = -1202,

kCFURLErrorServerCertificateHasUnknownRoot = -1203,

kCFURLErrorServerCertificateNotYetValid = -1204,

kCFURLErrorClientCertificateRejected = -1205,

kCFURLErrorClientCertificateRequired = -1206,

kCFURLErrorCannotLoadFromNetwork = -2000,

// Download and file I/O errors

kCFURLErrorCannotCreateFile = -3000,

kCFURLErrorCannotOpenFile = -3001,

kCFURLErrorCannotCloseFile = -3002,

kCFURLErrorCannotWriteToFile = -3003,

kCFURLErrorCannotRemoveFile = -3004,

kCFURLErrorCannotMoveFile = -3005,

kCFURLErrorDownloadDecodingFailedMidStream = -3006,

kCFURLErrorDownloadDecodingFailedToComplete = -3007,

// Cookie errors

kCFHTTPCookieCannotParseCookieFile = -4000,

// Errors originating from CFNetServices

kCFNetServiceErrorUnknown = -72000L,

kCFNetServiceErrorCollision = -72001L,

kCFNetServiceErrorNotFound = -72002L,

kCFNetServiceErrorInProgress = -72003L,

kCFNetServiceErrorBadArgument = -72004L,

kCFNetServiceErrorCancel = -72005L,

kCFNetServiceErrorInvalid = -72006L,

kCFNetServiceErrorTimeout = -72007L,

kCFNetServiceErrorDNSServiceFailure = -73000L //