tcp-environ — UCSPI-TCP environment variables
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.
TCPLOCALIPThe IPv4 address of the local host, in dotted-decimal form or the respective compactified IPv6 address.
TCPLOCALPORTThe 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.
TCPREMOTEIPThe IPv4 or compactified IPv6 address of the remote host.
TCPREMOTEPORTThe remote TCP port number.
TCP6INTERFACEThe interface name ("eth0") for IPv6 connections using link-local addresses.
TCP6REMOTEIPThe compactified or IPv4-mapped IPv6 address of the remote host.
TCP6REMOTEHOST
Identical to TCPREMOTEHOST.
TCP6REMOTEPORT
Identical to TCPREMOTEPORT.