.TH TOR 1 "November 2003" "TOR"
.SH NAME
tor \- The second-generation onion router
.SH SYNOPSIS
.B tor
[\fIOPTION value\fR]...
.SH DESCRIPTION
.I tor
is a connection-oriented anonymizing communication
service. Users choose a source-routed path through a set of nodes, and
negotiate a "virtual circuit" through the network, in which each node
knows its predecessor and successor, but no others. Traffic flowing down
the circuit is unwrapped by a symmetric key at each node, which reveals
the downstream node.
.PP
Basically \fItor\fR provides a distributed network of servers ("onion
routers"). Users bounce their tcp streams -- web traffic, ftp, ssh, etc --
around the routers, and recipients, observers, and even the routers
themselves have difficulty tracking the source of the stream.
.SH OPTIONS
\fB-h, -help\fP
Display a short help message and exit.
.TP
\fB-f \fR\fIFILE\fP
FILE contains further "option value" pairs. (Default: @CONFDIR@/torrc)
.TP
Other options can be specified either on the commandline (\fI--option value\fR), or in the configuration file (\fIoption value\fR).
.TP
\fBloglevel debug|info|notice|warn|err\fP
Set the verboseness level of the primary log. (Default: warn)
.TP
\fBlogfile \fR\fIFILE\fP
Rather than logging to stdout, log to FILE.
.TP
\fBbandwidthrate \fR\fINUM\fP
A token bucket limits the average incoming bandwidth on this node to NUM bytes per second. (Default: 800000)
.TP
\fBbandwidthburst \fR\fINUM\fP
Limit the maximum token bucket size (also known as the burst) to NUM bytes. (Default: 10000000)
.TP
\fBdebuglogfile \fR\fIFILE\fP
In addition to other logging, we will log to FILE at log-level debug.
.TP
\fBgroup \fR\fIGID\fP
On startup, setgid to this user.
.TP
\fBkeepaliveperiod \fR\fINUM\fP
To keep firewalls from expiring connections, send a padding keepalive cell on open connections every NUM seconds. (Default: 300)
.TP
\fBmaxconn \fR\fINUM\fP
Maximum number of simultaneous connections allowed.  You probably don't need
to adjust this. (Default: 900)
.TP
\fBoutboundbindaddress \fR\fIP\fP
Make all outbound connections originate from the IP address specified.  This
is only useful when you have multiple network interfaces, and you want all
of Tor's outgoing connections to use a single one.
.TP
\fBpidfile \fR\fIFILE\fP
On startup, write our PID to FILE. On clean shutdown, remove FILE.
.TP
\fBrouterfile \fR\fIFILE\fP
FILE contains a list of directory servers, to bootstrap into the network. (Default: @CONFDIR@/dirservers)
.TP
\fBrunasdaemon \fR\fI0|1\fP
If 1, Tor forks and daemonizes to the background. (Default: 0)
.TP
\fBuser \fR\fIUID\fP
On startup, setuid to this user.

.SH CLIENT OPTIONS
.PP
The following options are useful only for clients (that is, if \fBsocksport\fP is non-zero):
.TP
\fBallowunverifiednodes \fR\fIentry|exit|middle|introduction|rendezvous,...\fP
Where on our circuits should we allow Tor servers that the directory
servers haven't authenticated as "verified"?  (Default: middle,rendezvous.)
\fBdirfetchpostperiod \fR\fIseconds\fP
Every N seconds, Tor downloads a fresh directory, and re-uploads
information about hidden services to the directory servers.  If
running as a server, Tor also re-uploads information about itself to
the directory servers.  (Tor also uploads this information whenever it 
changes.)  (Default: 600.)
.TP
\fBclientonly \fR\fI0|1\fP
If set to 1, Tor will under no circumstances run as a server.  (Usually,
you don't need to set this; Tor is pretty smart at figuring out whether
you are reliable and high-bandwith enough to be a good server.)
.TP
\fBentrynodes \fR\fInickname,nickname,...\fP
A list of preferred nodes to use for the first hop in the circuit, if possible.
.TP
\fBexitnodes \fR\fInickname,nickname,...\fP
A list of preferred nodes to use for the last hop in the circuit, if possible.
.TP
\fBexcludenodes \fR\fInickname,nickname,...\fP
A list of nodes to never use when building a circuit.
.TP
\fBstrictexitnodes \fR\fI0|1\fP
If 1, Tor will never use any nodes besides those listed in "exitnodes" for
the last hop of a circuit.
.TP
\fBstrictentrynodes \fR\fI0|1\fP
If 1, Tor will never use any nodes besides those listed in "entrynodes" for
the first hop of a circuit.
.TP
\fBfascistfirewall \fR\fI0|1\fP
If 1, Tor will only create outgoing connections to ORs running on ports that
your firewall allows (defaults to 80 and 443; see firewallports).  This will
allow you to run Tor as a client behind a firewall with restrictive policies,
but will not allow you to run as a server behind such a firewall.
.TP
\fBfirewallports \fR\fIPORTS\fP
A list of ports that your firewall allows you to connect to.  Only used when
fascistfirewall is set. (Default: 80, 443.)
.TP
\fB 
\fBnewcircuitperiod \fR\fINUM\fP
Every NUM seconds consider whether to build a new circuit. (Default: 60)
.TP
\fBpathlencoinweight \fR\fI0.0-1.0\fP
Paths are 3 hops plus a geometric distribution centered around this coinweight. Must be >=0.0 and <1.0. (Default: 0.3) NOT USED CURRENTLY
.TP
\fBrendnodes \fR\fInickname,nickname,...\fP
A list of preferred nodes to use for the rendezvous point, if possible.
.TP
\fBrendexcludenodes \fR\fInickname,nickname,...\fP
A list of nodes to never use when choosing a rendezvous point.
.TP
\fBsocksport \fR\fIPORT\fP
Bind to this port to listen for connections from SOCKS-speaking applications.
Set this to 0 if you don't want to allow application connections. (Default:
9050)
.TP
\fBsocksbindaddress \fR\fIIP\fP
Bind to this address to listen for connections from socks-speaking applications. (Default: 127.0.0.1) You can also specify a port (e.g. 192.168.0.1:9100). This directive can be specified multiple times to bind to multiple addresses/ports.
.TP
\fBsockspolicy \fR\fIpolicy,policy,...\fP
Set an entrance policy for this server, to limit who can connect to the socks ports. The policies have the same form as exit policies below.

.SH SERVER OPTIONS
.PP
The following options are useful only for servers (that is, if \fBorport\fP is non-zero):
.TP
\fBaddress \fR\fIaddress\fP
The IP or fqdn of this server (e.g. moria.mit.edu).
.TP
\fBdatadirectory \fR\fIDIR\fP
Store working data in DIR (Default: @LOCALSTATEDIR@/lib/tor)
.TP
\fBexitpolicy \fR\fIpolicy,policy,...\fP
Set an exit policy for this server. Each policy is of the form
"\fBreject\fP \fIADDR\fP\fB/\fP\fIMASK\fP\fB:\fP\fIPORT\fP".
If \fB/\fP\fIMASK\fP is omitted then this policy just applies to the host
given.  Instead of giving a host or network you can also use "\fB*\fP" to
denote the universe (0.0.0.0/0).  \fIPORT\fP can either be a single port number
or an interval of ports: "\fIFROM_PORT\fP\fB-\fP\fITO_PORT\fP".

For example, "reject 127.0.0.1:*,reject 192.168.1.0/24:*,accept *:*" would
reject any traffic destined for localhost and any 192.168.1.* address, but
accept anything else.

This directive can be specified multiple times so you don't have to put
it all on one line.

See RFC 3330 for more details about internal and reserved IP address
space. The default exit policy is:
.PD 0
.RS 12
.IP "reject 0.0.0.0/8" 0
.IP "reject 169.254.0.0/16" 4
.IP "reject 127.0.0.0/8"
.IP "reject 192.168.0.0/16"
.IP "reject 10.0.0.0/8"
.IP "reject 172.16.0.0/12"
.IP "accept *:20-22"
.IP "accept *:53"
.IP "accept *:79-81"
.IP "accept *:110"
.IP "accept *:143"
.IP "accept *:443"
.IP "accept *:873"
.IP "accept *:993"
.IP "accept *:995" 4
.IP "reject *:4661-4662"
.IP "reject *:1214"
.IP "reject *:6346"
.IP "accept *:1024-65535"
.IP "reject *:*"
.RE
.PD
.TP
\fBmaxonionspending \fR\fINUM\fP
If you have more than this number of onionskins queued for decrypt, reject new ones. (Default: 100)
.TP
\fBnickname \fR\fIname\fP
Set the server's nickname to 'name'.
.TP
\fBnumcpus \fR\fInum\fP
How many processes to use at once for decrypting onionskins. (Default: 1)
.TP
\fBorport \fR\fIPORT\fP
Bind to this port to listen for connections from Tor clients and servers.
.TP
\fBorbindaddress \fR\fIIP\fP
Bind to this address to listen for connections from Tor clients and servers. (Default: 0.0.0.0)

.SH DIRECTORY SERVER OPTIONS
.PP
The following options are useful only for directory servers (that is, if \fBdirport\fP is non-zero):
.TP
\fBauthoritativedirectory \fR\fI0|1\fP
When this option is set to 1, Tor operates as an authoritative
directory server.  Instead of caching the directory, it generates its
own list of good servers, signs it, and sends that to the clients.
Unless the clients already have you listed as a trusted directory, you
probably do not want to set this option.  Please coordinate with the other
admins at tor-ops@freehaven.net if you think you should be a directory.
.TP
\fBcontactinfo \fR\fIemail address\fP
Administrative contact information for server.
.TP
\fBdirport \fR\fIPORT\fP
Bind the directory service to this port.
.TP
\fBdirbindaddress \fR\fIIP\fP
Bind the directory service to this address. (Default: 0.0.0.0)
.TP
\fBrecommendedversions \fR\fISTRING\fP
STRING is a command-separated list of Tor versions currently believed to be safe. The list is included in each directory, and nodes which pull down the directory learn whether they need to upgrade.
.TP
\fBruntesting \fR\fI0|1\fP
If set to 1, Tor tries to build circuits through all of the servers it
knows about, so it can tell which are up and which are down.  This
option is only useful for authoritative directories, so you probably
don't want to use it.


.SH HIDDEN SERVER OPTIONS
.PP
The following options are used to configure a hidden service.
.TP
\fBhiddenservicedir \fR\fIDIRECTORY\fP
Store data files for a hidden service in DIRECTORY.  Every hidden
service must have a separate directory.  You may use this option multiple
times to specify multiple services.
.TP
\fBhiddenserviceport \fR\fIVIRTPORT \fR[\fITARGET\fR]\fP
Configure a virtual port VIRTPORT for a hidden service.  You may use this
option multiple times; each time applies to the service using the most recent
hiddenservicedir.  By default, this option maps the virtual port to the
same port on 127.0.0.1.  You may override the target port, address, or both
by specifying a target of addr, port, or addr:port.
.TP
\fBhiddenservicenodes \fR\fInickname,nicknamme,...\fP
If possible, use the specified nodes as introduction points for the hidden
service.
.TP
\fBhiddenserviceexcludenodes \fR\fInickname,nicknamme,...\fP
Do not use the specified nodes as introduction points for the hidden
service.

.\" UNDOCUMENTED
.\" ignoreversion

.SH FILES
.TP
.I @CONFDIR@/torrc
The configuration file, which contains "option value" pairs.
.TP
.I @CONFDIR@/dirservers
A list of directory servers, to bootstrap into the network.
.TP
.I @LOCALSTATEDIR@/lib/tor/
The tor process stores keys and other data here.

.SH SEE ALSO
.BR privoxy (1),
.BR tsocks (1)

.BR http://freehaven.net/tor/

.SH BUGS
Plenty, probably. It's still in alpha. Please report them.
.SH AUTHORS
Roger Dingledine <arma@mit.edu>, Nick Mathewson <nickm@alum.mit.edu>.
