Type: System.Net.SocketPermissionAttribute

System.Net.SocketPermissionAttribute Class

Assembly: System.dll
Namespace: System.Net

Summary: Specifies security actions to control Socket connections. This class cannot be inherited.

C# Syntax:

[AttributeUsage(AttributeTargets.Assembly | AttributeTargets.Class | AttributeTargets.Struct | AttributeTargets.Constructor | AttributeTargets.Method)]
[Serializable]
public sealed class SocketPermissionAttribute : CodeAccessSecurityAttribute

Remarks

To use this attribute, your Socket connection must conform to the properties specified in your SocketPermissionAttribute. For example, to secure a Socket connection on port 80, set the SocketPermissionAttribute.Port property of the SocketPermissionAttribute to "80." The security information specified in SocketPermissionAttribute is stored in the metadata of the attribute target, which is the class to which the SocketPermissionAttribute is applied. The system then accesses the information at run time. The SecurityAction passed to the constructor determines the allowable SocketPermissionAttribute targets.

Note The properties of a SocketPermissionAttribute must have values that are not null. Also, once set, the values of the properties cannot be changed.

Note SocketPermissionAttribute is used for the conceptual topic at MSDN: declarativesecurity only. For the conceptual topic at MSDN: imperativesecurity, use the corresponding SocketPermission.

Note For more information about using attributes, see the conceptual topic at MSDN: extendingmetadatausingattributes.

Example

The following example demonstrates how to apply SocketPermissionAttribute to a custom class.

	[SocketPermission(SecurityAction.Assert, Access = "Connect", 
					Host = "192.168.144.238", Port = "All", Transport = "All")]
	[SocketPermission(SecurityAction.Deny, Access = "Connect", 
					Host = "192.168.144.239", Port = "All", Transport = "All")]
	public String GetDate() {

		// Gets the current date from the remote date server.
		try {
			int bytesReceived;		
			byte[] getByte = new byte[100];
			Socket mysocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
			try {
                           mysocket.Connect(new IPEndPoint(IPAddress.Parse("192.168.144.239"), 13));		
                    }
             catch (SecurityException e){
			    Console.WriteLine("SecurityException (expected)" + e.Message);
                     }

			mysocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
                     mysocket.Connect(new IPEndPoint(IPAddress.Parse("192.168.144.238"), 13));		
			bytesReceived = mySocket.Receive( getByte, getByte.Length, 0 );
			return asciiEncoding.GetString( getByte, 0, bytesReceived );
		}
		catch(Exception e)
		{
			Console.WriteLine(e.Message);
			return "";
		}
	}

System.Net.SocketPermissionAttribute Member List:

Public Constructors

ctor #1

Initializes a new instance of the SocketPermissionAttribute class with the specified SecurityAction value.

Public Properties

Access	Read-write Gets or sets the network access method allowed by this SocketPermissionAttribute.
Action (inherited from System.Security.Permissions.SecurityAttribute)	Read-write See base class member description: System.Security.Permissions.SecurityAttribute.Action Gets or sets a security action.
Host	Read-write Gets or sets the DNS host name or IP address specified by this SocketPermissionAttribute.
Port	Read-write Gets or sets the port number associated with this SocketPermissionAttribute.
Transport	Read-write Gets or sets the TransportType specified by this SocketPermissionAttribute.
TypeId (inherited from System.Attribute)	Read-only See base class member description: System.Attribute.TypeId When implemented in a derived class, gets a unique identifier for this Attribute.
Unrestricted (inherited from System.Security.Permissions.SecurityAttribute)	Read-write See base class member description: System.Security.Permissions.SecurityAttribute.Unrestricted Gets or sets a value indicating whether full (unrestricted) permission to the resource protected by the attribute is declared.

Public Methods

CreatePermission	Overridden: Creates and returns a new instance of the SocketPermission class.
Equals (inherited from System.Object)	See base class member description: System.Object.Equals Derived from System.Object, the primary base class for all objects.
GetHashCode (inherited from System.Attribute)	See base class member description: System.Attribute.GetHashCode Returns the hash code for this instance.
GetType (inherited from System.Object)	See base class member description: System.Object.GetType Derived from System.Object, the primary base class for all objects.
IsDefaultAttribute (inherited from System.Attribute)	See base class member description: System.Attribute.IsDefaultAttribute When overridden in a derived class, returns an indication whether the value of this instance is the default value for the derived class.
Match (inherited from System.Attribute)	See base class member description: System.Attribute.Match When overridden in a derived class, returns a value indicating whether this instance equals a specified object.
ToString (inherited from System.Object)	See base class member description: System.Object.ToString Derived from System.Object, the primary base class for all objects.

Protected Methods

Finalize (inherited from System.Object)	See base class member description: System.Object.Finalize Derived from System.Object, the primary base class for all objects.
MemberwiseClone (inherited from System.Object)	See base class member description: System.Object.MemberwiseClone Derived from System.Object, the primary base class for all objects.

Hierarchy:

System.Object

System.Attribute

System.Security.Permissions.SecurityAttribute

System.Security.Permissions.CodeAccessSecurityAttribute

System.Net.SocketPermissionAttribute

System.Net.SocketPermissionAttribute Member Details

ctor #1

Summary: Initializes a new instance of the SocketPermissionAttribute class with the specified SecurityAction value.

C# Syntax:


            public SocketPermissionAttribute(
   SecurityAction action
);

Parameters:

action

One of the SecurityAction values.

Remarks

The SecurityAction value passed to this constructor specifies the allowable SocketPermissionAttribute targets.

Example

The following example demonstrates how to apply SocketPermissionAttribute to a custom class.

	[SocketPermission(SecurityAction.Assert, Access = "Connect", 
					Host = "192.168.144.238", Port = "All", Transport = "All")]
	[SocketPermission(SecurityAction.Deny, Access = "Connect", 
					Host = "192.168.144.239", Port = "All", Transport = "All")]
	public String GetDate() {

		// Gets the current date from the remote date server.
		try {
			int bytesReceived;		
			byte[] getByte = new byte[100];
			Socket mysocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
			try {
                           mysocket.Connect(new IPEndPoint(IPAddress.Parse("192.168.144.239"), 13));		
                    }
             catch (SecurityException e){
			    Console.WriteLine("SecurityException (expected)" + e.Message);
                     }

			mysocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
                     mysocket.Connect(new IPEndPoint(IPAddress.Parse("192.168.144.238"), 13));		
			bytesReceived = mySocket.Receive( getByte, getByte.Length, 0 );
			return asciiEncoding.GetString( getByte, 0, bytesReceived );
		}
		catch(Exception e)
		{
			Console.WriteLine(e.Message);
			return "";
		}
	}

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Property: Access (read-write)

Summary: Gets or sets the network access method allowed by this SocketPermissionAttribute.

C# Syntax:


            public string Access {get; set;}

Exceptions

Exception Type	Condition
ArgumentException	The SocketPermissionAttribute.Access property is not null when you attempt to set the value. If you wish to specify more than one Access method, use an additional attribute declaration statement.

Remarks

This property is write-once. Valid values for this property correspond to NetworkAccess enumeration values.

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Property: Action (read-write)

Inherited
See base class member description: System.Security.Permissions.SecurityAttribute.Action

Summary: Gets or sets a security action.

C# Syntax:


            public SecurityAction Action {get; set;}

Remarks

This property is inherited by all classes implementing custom attributes for declarative security.

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Property: Host (read-write)

Summary: Gets or sets the DNS host name or IP address specified by this SocketPermissionAttribute.

C# Syntax:


            public string Host {get; set;}

Exceptions

Exception Type	Condition
ArgumentException	SocketPermissionAttribute.Host is not null when you attempt to set the value. If you wish to specify more than one host, use an additional attribute declaration statement.

Remarks

This property is write-once and specifies the Domain Name Services (DNS) host name to which this permission applies.

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Property: Port (read-write)

Summary: Gets or sets the port number associated with this SocketPermissionAttribute.

C# Syntax:


            public string Port {get; set;}

Exceptions

Exception Type	Condition
ArgumentException	The SocketPermissionAttribute.Port property is null when attempt to set the value. If you wish to specify more than one port, use an additional attribute declaration statement.

Remarks

This property is write-once and specifies the port number to which this permission applies. The valid values are a string-encoded integer, or the string "All".

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Property: Transport (read-write)

Summary: Gets or sets the TransportType specified by this SocketPermissionAttribute.

C# Syntax:


            public string Transport {get; set;}

Exceptions

Exception Type	Condition
ArgumentException	SocketPermissionAttribute.Transport is not null when you attempt to set the value. If you wish to specify more than one transport type, use an additional attribute declaration statement.

Remarks

Possible string values of this property are TransportType.All, TransportType.Connectionless, TransportType.ConnectionOriented, TransportType.Tcp, TransportType.Udp.

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Property: TypeId (read-only)

Inherited
See base class member description: System.Attribute.TypeId

Summary: When implemented in a derived class, gets a unique identifier for this Attribute.

C# Syntax:


            public virtual object TypeId {get;}

Remarks

As implemented, this identifier is merely the Type of the attribute. However, it is intended that the unique identifier be used to identify two attributes of the same type.

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Property: Unrestricted (read-write)

Inherited
See base class member description: System.Security.Permissions.SecurityAttribute.Unrestricted

Summary: Gets or sets a value indicating whether full (unrestricted) permission to the resource protected by the attribute is declared.

C# Syntax:


            public bool Unrestricted {get; set;}

Remarks

This property is inherited by all classes implementing custom attributes for declarative security.

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Overridden Method: CreatePermission()

Summary: Creates and returns a new instance of the SocketPermission class.

C# Syntax:


            public override IPermission CreatePermission();

Return Value:: An instance of the SocketPermission class corresponding to the security declaration.

Remarks

The SocketPermissionAttribute.CreatePermission method is called by the security system, not by application code. The security information described by SocketPermissionAttribute is stored in the metadata of the attribute target, which is the class to which the SocketPermissionAttribute is applied. The system then accesses the information at runtime and calls SocketPermissionAttribute.CreatePermission. The system uses the returned IPermission to enforce the specified security requirements.

See also:
SocketPermission

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Method: Equals(
object obj
)

Inherited
See base class member description: System.Object.Equals

C# Syntax:


            public virtual bool Equals(
   object obj
);

For more information on members inherited from System.Object click on the link above.

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Method: Finalize()

Inherited
See base class member description: System.Object.Finalize

C# Syntax:


            ~SocketPermissionAttribute();

For more information on members inherited from System.Object click on the link above.

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Method: GetHashCode()

Inherited
See base class member description: System.Attribute.GetHashCode

Summary: Returns the hash code for this instance.

C# Syntax:


            public override int GetHashCode();

Return Value:: A 32-bit signed integer hash code.

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Method: GetType()

Inherited
See base class member description: System.Object.GetType

C# Syntax:


            public Type GetType();

For more information on members inherited from System.Object click on the link above.

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Method: IsDefaultAttribute()

Inherited
See base class member description: System.Attribute.IsDefaultAttribute

Summary: When overridden in a derived class, returns an indication whether the value of this instance is the default value for the derived class.

C# Syntax:


            public virtual bool IsDefaultAttribute();

Return Value:: true if this instance is the default attribute for the class; otherwise, false.

Remarks

The default implementation of this class returns false, and must be implemented in the derived class to be useful to that class.

The implementation of this method in a derived class compares the value of this instance to a standard, default value obtained by some means, then returns a Boolean value that indicates whether the value of this instance is equal to the standard. The standard value is typically coded as a constant in the implementation, or stored programmatically in a field used by the implementation.

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Method: Match(
object obj
)

Inherited
See base class member description: System.Attribute.Match

Summary: When overridden in a derived class, returns a value indicating whether this instance equals a specified object.

C# Syntax:


            public virtual bool Match(
   object obj
);

Parameters:

obj

An Object to compare with this instance of Attribute.

Return Value:: true if this instance equals obj; otherwise, false.

Remarks

This method determines if one Attribute equals another. Its default implementation is the same as Attribute.Equals, which performs a value and reference comparison. Override this method to implement support for attribute values, such as flags or bitfields, that consist of components that are meaningful in themselves. For example, consider an attribute whose value is a binary field divided into a bitfield of flags. Two instances of this attribute have one flag in set in common while all the other flags differ. The Equal method cannot determine that the two instances have the same flag set, but the Match method can.

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Method: MemberwiseClone()

Inherited
See base class member description: System.Object.MemberwiseClone

C# Syntax:


            protected object MemberwiseClone();

For more information on members inherited from System.Object click on the link above.

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Method: ToString()

Inherited
See base class member description: System.Object.ToString

C# Syntax:


            public virtual string ToString();

For more information on members inherited from System.Object click on the link above.