Name

tcp-environ — UCSPI-TCP environment variables

Description

The following environment variables describe a TCP connection. They are set up by tcpserver(1), tcpclient(1), and tcp-env(1). Note that TCPLOCALHOST, TCPREMOTEHOST, and TCPREMOTEINFO can contain arbitrary characters and attacker-supplied information.

PROTO

The string TCP or TCP6, indicating which family of environment variable names to use.

TCPLOCALHOST

The domain name of the local host, with uppercase letters converted to lowercase. If there is no currently available domain name for the local IP address, TCPLOCALHOST is not set.

TCPLOCALIP

The IPv4 address of the local host, in dotted-decimal form or the respective compactified IPv6 address.

TCPLOCALPORT

The local TCP port number, in decimal.

TCPREMOTEHOST

The domain name of the remote host, with uppercase letters converted to lowercase. If there is no currently available domain name for the remote IP address, TCPREMOTEHOST is not set.

TCPREMOTEINFO

A connection-specific string, perhaps a username, supplied by the remote host via 931/1413/IDENT/TAP. If the remote host did not supply connection information, TCPREMOTEINFO is not set.

TCPREMOTEIP

The IPv4 or compactified IPv6 address of the remote host.

TCPREMOTEPORT

The remote TCP port number.

TCP6INTERFACE

The interface name ("eth0") for IPv6 connections using link-local addresses.

TCP6REMOTEIP

The compactified or IPv4-mapped IPv6 address of the remote host.

TCP6REMOTEHOST

Identical to TCPREMOTEHOST.

TCP6REMOTEPORT

Identical to TCPREMOTEPORT.

See also

tcpserver(1)
tcpclient(1)
tcp-env(1)
tcp(4)

Author

Original code and documentation by Daniel J. Bernstein. Converted to manual pages and updated by Gerrit Pape in 2000, 2001, and 2002. Converted to DocBook XML by Jonathan de Boyne Pollard.