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tproxy(8)              DragonFly System Manager's Manual             tproxy(8)

NAME
       tproxy - transparently re-direct HTTP requests to a HTTP cache.

SYNOPSIS
       tproxy [ -t | -p ] [ -f forced-url ] [ -s bind-port

       [ -d ] [ -b bind-address ] [ -r runas-uid ] [ -a access-ip-address ] ]
       [ -l log-file ] proxyhost proxyport

DESCRIPTION
       tproxy accepts HTTP requests and forwards them to a cache host. If the
       HTTP request has been transparently re-directed, the URL is re-written
       so that the cache host knows what web server to fetch the document
       from. Tcp_wrappers is used to provide host access control.

       The proxy-cache host's address and port are given by proxyhost and
       proxyport.

OPTIONS
       -t     Operate in a fully transparent mode. Instead of connecting to a
              proxy and sending a re-written URL, connect only the intended
              destination and send the real URL. This option can be used to
              allow tproxy to operate as a HTTP gateway (or proxy) on a
              firewall.

       -p     Operate in proxy only mode. Normally if the connection to the
              proxy fails, tproxy will try and connect transparently to the
              intended destination. However for some sites this will never
              work and it is better to simply fail the connection.

       -f url Force all accesses to be sent to the specified URL.  tproxy
              checks for accesses that are referred by this forced URL and
              allows then to pass. This allows images on the forced URL to
              work.

       -s port
              Run as a server and bind to the specified port. Alternatively
              tproxy may be run from either inetd or a program such a
              tcpserver. In these cases this options is not given.

       -d     When running as a server, do not background the daemon. Usefull
              when tproxy is started from inetd or from the supplied
              tproxywatch program.

       -b ipaddr
              Bind to the specified IP address. When run as a server tproxy
              will not accept requests sent to any other address when the host
              has multiple addresses.

       -r user
              Run as the specified user. The user must exist in the
              /etc/passwd database so that its uid and gid can be obtained.

       -a access-ipaddr
              Provide an IP address, network, sub-net, or super-net to allow
              access. May be specified more than once. If the host portion of
              the address in non-zero then the address refers to a host,
              otherwise it is assumed to refer to a network.  The number of
              bits may be given in CIDR notation to specify a sub-net or
              super-net.

       -l log-file
              Log all accesses to the specified file. The logfile will
              indicate if the request was done transparently, it was done
              without DNS activity, or it required DNS activity.

FINE POINTS
       tproxy is not an all-in-one transparent proxy solution. It requires
       support from the operating system, and configuration from the system
       administrator, to transparently capture HTTP requests.

       tproxyrun provides an example script to add firewall commands and start
       tproxy running.  It currently supports FreeBSD-3.x and various versions
       of Linux. See the environment variable definitions at the top of the
       file.

       tproxywatch provides a mechanism of ensuring that tproxy is re-started
       should it fail.  Whenever tproxy exits an email is sent to the root
       account and then tproxy is re-started.

       FreeBSD-3.x provides two methods of transparently capturing packets.
       The first is ipfw(8) using the following example configuration.

       ipfw add 1000 allow tcp from 192.168.1.1 to any 80

       ipfw add 1001 fwd 192.168.1.1,8081 tcp from any to any 80

       The second is ipnat(1) using the following example configuration. Note
       that a rule is required for every interface you wish to transparently
       re-direct for.

       rdr ppp0 0.0.0.0/0 port 80 -> 192.168.1.1 port 8081

       Linux provides the same mechanism with either the ipchains(8) command,
       kernels 2.1.x and up, using the following example configuration.

       ipchains -A input -p tcp -d 0.0.0.0/0 80 -j REDIRECT 8081

       Or the ipfwadm(8) command, kernels 2.0.x, using the following example
       configuration.

       ipfwadm -I -a accept -P tcp -D 0.0.0.0/0 80 -r 8081

SEE ALSO
       hosts_access(5), tcpserver(1), ipfw(8), ipnat(1), ipfwadm(8),
       ipchains(8)

AUTHORS
       Written by John Saunders <john@nlc.net.au>

       Copyright 1998, 1999, 2000    NORTHLINK COMMUNICATIONS PTY LTD.  All
       rights reserved.

                                                                     tproxy(8)