.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|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 \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 \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 \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) .TP \fBsocksport \fR\fIPORT\fP Bind to this port to listen for connections from socks-speaking applications. .TP \fBsocksbindaddress \fR\fIIP\fP Bind to this address to listen for connections from socks-speaking applications. (Default: 127.0.0.1) .SH SERVER OPTIONS .PP The following options are useful only for servers (that is, if \fBorport\fP is non-zero): .TP \fBaddress address\fP The 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 "reject ADDR/MASK:PORT". 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. .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 \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. .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 server stores keys/etc 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 .