Stem Docs

Connection Utilities

Connection Utilities

Connection and networking based utility functions.

Module Overview:

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.

New in version 1.1.0.

Changed in version 1.4.0: Added NETSTAT_WINDOWS.

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
class stem.util.connection.Connection

Bases: stem.util.connection.Connection

Network connection information.

Changed in version 1.5.0: Added the is_ipv6 attribute.

Variables:
  • local_address (str) -- ip address the connection originates from
  • local_port (int) -- port the connection originates from
  • remote_address (str) -- destionation ip address
  • remote_port (int) -- destination port
  • protocol (str) -- protocol of the connection ('tcp', 'udp', etc)
  • is_ipv6 (bool) -- addresses are ipv6 if true, and ipv4 otherwise
stem.util.connection.get_connections(resolver=None, process_pid=None, process_name=None)

Retrieves a list of the current connections for a given process. This provides a list of Connection. Note that addresses may be IPv4 or IPv6 depending on what the platform supports.

New in version 1.1.0.

Changed in version 1.5.0: Made our resolver argument optional.

Changed in version 1.5.0: IPv6 support when resolving via proc, netstat, lsof, or ss.

Parameters:
  • resolver (Resolver) -- method of connection resolution to use, if not provided then one is picked from among those that should likely be available for the system
  • process_pid (int) -- pid of the process to retrieve
  • process_name (str) -- name of the process to retrieve
Returns:

list of Connection instances

Raises :
  • ValueError if neither a process_pid nor process_name is provided
  • IOError if no connections are available or resolution fails (generally they're indistinguishable). The common causes are the command being unavailable or permissions.
stem.util.connection.system_resolvers(system=None)

Provides the types of connection resolvers likely to be available on this platform.

New in version 1.1.0.

Changed in version 1.3.0: Renamed from get_system_resolvers() to system_resolvers(). The old name still works as an alias, but will be dropped in Stem version 2.0.0.

Parameters:system (str) -- system to get resolvers for, this is determined by platform.system() if not provided
Returns:list of Resolver instances available on this platform
stem.util.connection.port_usage(port)

Provides the common use of a given port. For example, 'HTTP' for port 80 or 'SSH' for 22.

New in version 1.2.0.

Parameters:port (int) -- port number to look up
Returns:str with a description for the port, None if none is known
stem.util.connection.is_valid_ipv4_address(address)[source]

Checks if a string is a valid IPv4 address.

Parameters:address (str) -- string to be checked
Returns:True if input is a valid IPv4 address, False otherwise
stem.util.connection.is_valid_ipv6_address(address, allow_brackets=False)[source]

Checks if a string is a valid IPv6 address.

Parameters:
  • address (str) -- string to be checked
  • allow_brackets (bool) -- ignore brackets which form '[address]'
Returns:

True if input is a valid IPv6 address, False otherwise

stem.util.connection.is_valid_port(entry, allow_zero=False)[source]

Checks if a string or int is a valid port number.

Parameters:
  • entry (list,str,int) -- string, integer or list to be checked
  • allow_zero (bool) -- accept port number of zero (reserved by definition)
Returns:

True if input is an integer and within the valid port range, False otherwise

stem.util.connection.is_private_address(address)

Checks if the IPv4 address is in a range belonging to the local network or loopback. These include:

  • Private ranges: 10.*, 172.16.* - 172.31.*, 192.168.*
  • Loopback: 127.*

New in version 1.1.0.

Parameters:address (str) -- string to be checked
Returns:True if input is in a private range, False otherwise
Raises :ValueError if the address isn't a valid IPv4 address
stem.util.connection.address_to_int(address)

Provides an integer representation of a IPv4 or IPv6 address that can be used for sorting.

New in version 1.5.0.

Parameters:address (str) -- IPv4 or IPv6 address
Returns:int representation of the address
stem.util.connection.expand_ipv6_address(address)[source]

Expands abbreviated IPv6 addresses to their full colon separated hex format. For instance...

>>> expand_ipv6_address('2001:db8::ff00:42:8329')
'2001:0db8:0000:0000:0000:ff00:0042:8329'

>>> expand_ipv6_address('::')
'0000:0000:0000:0000:0000:0000:0000:0000'

>>> expand_ipv6_address('::ffff:5.9.158.75')
'0000:0000:0000:0000:0000:ffff:0509:9e4b'
Parameters:address (str) -- IPv6 address to be expanded
Raises :ValueError if the address can't be expanded due to being malformed
stem.util.connection.get_mask_ipv4(bits)[source]

Provides the IPv4 mask for a given number of bits, in the dotted-quad format.

Parameters:bits (int) -- number of bits to be converted
Returns:str with the subnet mask representation for this many bits
Raises :ValueError if given a number of bits outside the range of 0-32
stem.util.connection.get_mask_ipv6(bits)[source]

Provides the IPv6 mask for a given number of bits, in the hex colon-delimited format.

Parameters:bits (int) -- number of bits to be converted
Returns:str with the subnet mask representation for this many bits
Raises :ValueError if given a number of bits outside the range of 0-128
stem.util.connection.get_system_resolvers(system=None)

Provides the types of connection resolvers likely to be available on this platform.

New in version 1.1.0.

Changed in version 1.3.0: Renamed from get_system_resolvers() to system_resolvers(). The old name still works as an alias, but will be dropped in Stem version 2.0.0.

Parameters:system (str) -- system to get resolvers for, this is determined by platform.system() if not provided
Returns:list of Resolver instances available on this platform