tcp-environ 5 file formats djbwares tcp-environ UCSPI-TCP environment variables The following environment variables describe a TCP connection. They are set up by tcpserver1, tcpclient1, and tcp-env1. 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. tcpserver1 tcpclient1 tcp-env1 tcp4 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.