This permission represents access to a network via sockets.
A SocketPermission consists of a host specification and a set of actions
specifying ways to connect to that host. The host is specified as
The host is expressed as a DNS name, as a numerical IP address, or as
"localhost" (for the local machine). The wildcard "*"
may be included once
in a DNS name host specification. If it is included, it must be in the
leftmost position, as in "*.sun.com".
The port or portrange is optional. A port specification of the form "N-",
where N is a port number, signifies all ports numbered N and above,
while a specification of the form "-N" indicates all ports numbered
N and below.
The possible ways to connect to the host are
accept
connect
listen
resolve
The "listen" action is only meaningful when used with "localhost".
The "resolve" (resolve host/ip name service lookups) action is implied when
any of the other actions are present.
As an example of the creation and meaning of SocketPermissions, note that if
the following permission
is granted, it allows that code to accept connections on, connect to, or listen
on any port between 1024 and 65535 on the local host.
@attention
Granting code permission to accept or make connections to remote hosts may be
dangerous because malevolent code can then more easily transfer and share
confidential data among parties who may not otherwise have access to the data.