socks_clients.1

Linux下的socks的程序源程序,用于socks的代理服务

.TH SOCKS_CLIENTS 1 "November 16, 1993"
.SH NAME
.nf
rfinger \- SOCKS client version of finger
rftp \- SOCKS client version of ftp
rtelnet \- SOCKS client version of telnet
rwhois \- SOCKS client version of whois
.fi
.SH SYNOPSIS
See the man pages on \fIfinger\fP(1), \fIftp\fP(1), \fItelnet\fP(1),
\fIwhois\fP(1).
.SH DESCRIPTION
These programs provide the well-known functionalities to hosts within
a firewall. Normally, when a firewall is constructed, IP-accessibility
across the firewall is cut off to reduce security risk to hosts within
the firewall. As a result, inside hosts can no longer use many of the
well-known tools directly to access the resources outside the firewall.

These programs restore the convenience of the well-known tools while
maintaining the security requirement. Though the programs differ very
much from their counterparts in the use of the communication scheme,
they should behave almost indistinguishable to the users. Note though
that rftp does echo the password as you type it in if you are using
\fIanonymous\fP as log-in name. Unlike those of the previous versions,
these are "versatile" clients, meaning that they can be used for
connections to inside hosts directly and to outside hosts via SOCKS
proxy servers. So they can be used as replacements of their traditional
counterparts.

When any of these programs starts, if the environment variable
\fBSOCKS_BANNER\fR is defined, the program prints to \fBstderr\fP
its version number and
the name or IP address of its default SOCKS proxy server.
It then consults the configuration file \fB/etc/socks.conf\fP to
determine whether a request should be allowed or denied based on the
requesting user, the destination host, and the requested service. For
allowable requests, the configuration file also dictates whether
direct or proxy connection should be used to the given destination,
and optionally the actual SOCKS servers to use for the proxy connection.
See \fIsocks.conf\fP(5). If the file is absent, these programs will
only try direct connections to the destination hosts, making them
behaving like their regular counterparts.

You can use environment variable \fBSOCKS_NS\fR to set the nameserver for
domainname resolutions. Be sure you use the IP address of the
nameserver you want to use, not its domainname. If \fBSOCKS_NS\fR doesn't
exist, the IP address defined by the symbol \fBSOCKS_DEFAULT_NS\fR
at compile time is used if the programs were compiled with that symbol
defined. Otherwise the nameservers specified in \fB/etc/resolv.conf\fR
are used.

All the client programs uses \fIsyslog\fP with facility \fBdaemon\fR
and level \fBnotice\fR to log their activities. 
These log lines usually appear in file \fB/var/adm/messages\fP though
that can be changed by modifying \fB/etc/syslog.conf\fR. (See
\fIsyslogd\fP(8) and \fIsyslog.conf\fP(5).)
Typical lines look like

.nf
.in +1
Apr 11 10:02:23 eon rfinger[631]: connect() from don(don) to abc.com (finger) using sockd at socksserv
May 10 08:39:07 eon rftp[603]: connect() directly from blue(blue) to xyz.edu (ftp)
May 10 08:39:09 eon rftp[603]: bind() directly from blue(blue) for xyz.edu (ftp)
May 18 13:31:19 eon rtelnet[830]: connect() from root(jon) to xyz.edu (telnet) using sockd at sockd2
May 18 14:51:19 eon rtelnet[921]: refused -- connect() from jon(jon) to xyz.edu (telnet)
.in -1
.fi

Of the two user-ids appearing in each log line, the first is the
effective user-id when the program is invoked, the second (that
within the parentheses) is the one used at login. Access
control applies to the effective user-ids.
.SH SEE ALSO
\fIsockd\fP(8), \fIfinger\fP(1),  \fIftp\fP(1), \fItelnet\fP(1),
\fIwhois\fP(1)
.SH ENVIRONMENT
\fBSOCKS_SERVER\fR, if defined, specifies the name or IP address of the
SOCKS proxy server host to use, overriding the default server
compiled into the programs.

\fBSOCKS_NS\fR, if defined, specify the IP address of the domain nameserver
that should be used for name resolution, overriding both the definition
of symbol \fBSOCKS_DEFAULT_NS\fR and the file \fB/etc/resolv.conf\fR.

\fBORIG_FINGER\fR, if defined, specified the (altered) full pathname of
the original
finger program, which should have been renamed before installing the
rfinger as the regular finger. The \fIrfinger\fP program invokes
the original \fIfinger\fP program to lookup information on local users.
Normally this name should be compiled directly into \fIrfinger\fP, avoiding
the need for this environment variable. Use \fBORIG_FINGER\FR only if
you want to override what is compiled into \fIrfinger\fP.

.SH AUTHOR
David Koblas, [e-mail]
.PP
Ying-Da Lee, [e-mail]