Connection Utilities
********************

Connection and networking based utility functions.

**Module Overview:**

   download - download from a given url
   get_connections - quieries the connections belonging to a given process
   system_resolvers - provides connection resolution methods that are likely to be available
   port_usage - brief description of the common usage for a port

   is_valid_ipv4_address - checks if a string is a valid IPv4 address
   is_valid_ipv6_address - checks if a string is a valid IPv6 address
   is_valid_port - checks if something is a valid representation for a port
   is_private_address - checks if an IPv4 address belongs to a private range or not

   address_to_int - provides an integer representation of an IP address

   expand_ipv6_address - provides an IPv6 address with its collapsed portions expanded
   get_mask_ipv4 - provides the mask representation for a given number of bits
   get_mask_ipv6 - provides the IPv6 mask representation for a given number of bits

stem.util.connection.Resolver(enum)

   Method for resolving a process’ connections.

   Added in version 1.1.0.

   Changed in version 1.4.0: Added **NETSTAT_WINDOWS**.

   Changed in version 1.6.0: Added **BSD_FSTAT**.

   Deprecated since version 1.6.0: The SOCKSTAT connection resolver is
   proving to be unreliable (ticket 23057), and will be dropped in the
   2.0.0 release unless fixed.

   +----------------------+--------------------------------+
   | Resolver             | Description                    |
   |======================|================================|
   | **PROC**             | /proc contents                 |
   +----------------------+--------------------------------+
   | **NETSTAT**          | netstat                        |
   +----------------------+--------------------------------+
   | **NETSTAT_WINDOWS**  | netstat command under Windows  |
   +----------------------+--------------------------------+
   | **SS**               | ss command                     |
   +----------------------+--------------------------------+
   | **LSOF**             | lsof command                   |
   +----------------------+--------------------------------+
   | **SOCKSTAT**         | sockstat command under *nix    |
   +----------------------+--------------------------------+
   | **BSD_SOCKSTAT**     | sockstat command under FreeBSD |
   +----------------------+--------------------------------+
   | **BSD_PROCSTAT**     | procstat command under FreeBSD |
   +----------------------+--------------------------------+
   | **BSD_FSTAT**        | fstat command under OpenBSD    |
   +----------------------+--------------------------------+
