NNRPD(8) | InterNetNews Documentation | NNRPD(8) |
nnrpd - NNTP server for reader clients
nnrpd [-DfnoSt] [-4 address] [-6 address] [-b address] [-c configfile] [-i initial] [-I instance] [-p port] [-P prefork] [-r reason] [-s padding]
nnrpd is an NNTP server for newsreaders. It accepts commands on its standard input and responds on its standard output. It is normally invoked by innd(8) with those descriptors attached to a remote client connection. nnrpd also supports running as a standalone daemon.
Unlike innd(8), nnrpd supports all NNTP commands for user-oriented reading and posting. nnrpd uses the readers.conf file to control who is authorized to access the Usenet database.
On exit, nnrpd will report usage statistics through syslog(3).
nnrpd only reads config files (both readers.conf and inn.conf) when it is spawned. You can therefore never change the behavior of a client that's already connected. If nnrpd is run from innd (the default) or from inetd(8), xinetd(8), or some equivalent, a new nnrpd process is spawned for every connection and therefore any changes to configuration files will be immediately effective for all new connections. If you are instead running nnrpd with the -D option, any configuration changes won't take effect until nnrpd is restarted.
The inn.conf setting nnrpdflags can be used to pass any of the options below to instances of nnrpd that are spawned directly from innd. Many options only make sense when -D is used, so these options should not be used with nnrpdflags. See also the discussion of nnrpdflags in inn.conf(5).
When nnrpdloadlimit in inn.conf is not 0, it will also reject connections if the load average is greater than that value (typically 16). nnrpd can also prevent high-volume posters from abusing your resources. See the discussion of exponential backoff in inn.conf(5).
By default, nnrpd in daemon mode listens to both IPv4 and IPv6 addresses. With this option, it will listen only to the specified IPv6 addresses. On some systems however, a value of "::0" will cause it to listen to all IPv4 addresses as well.
When started in daemon mode, nnrpd will write its PID into a file in the pathrun directory. The file will be named nnrpd.pid if nnrpd listens on port 119 (default), or nnrpd-%d.pid, where %d is replaced with the port that nnrpd is configured to listen on (-p option is given and its argument is not 119).
If INN is built with --with-openssl or if the OpenSSL SSL and crypto libraries are found at configure time, nnrpd will support news reading over TLS (also known as SSL). For clients that use the STARTTLS command, no special configuration is needed beyond creating a TLS/SSL certificate for the server. You should do this in exactly the same way that you would generate a certificate for a web server.
If you're happy with a self-signed certificate (which will generate warnings with some news reader clients), you can create and install one in the default path by running "make cert" after "make install" when installing INN, or by running the following commands:
umask 077 openssl req -new -x509 -nodes -out <pathetc>/cert.pem \ -days 366 -keyout <pathetc>/key.pem chown news:news <pathetc>/cert.pem chmod 640 <pathetc>/cert.pem chown news:news <pathetc>/key.pem chmod 600 <pathetc>/key.pem
Replace the paths with something appropriate to your INN installation. This will create a self-signed certificate that will expire in a year. The openssl program will ask you a variety of questions about your organization. Enter the fully qualified domain name of your news service (either the server canonical name or a dedicated alias for the news service) as the name the certificate is for.
You then have to set these inn.conf parameters with the right paths:
tlscapath: <pathetc> tlscertfile: <pathetc>/cert.pem tlskeyfile: <pathetc>/key.pem
In case you have a certificate authority root certificate, you can also set tlscafile to its path.
There are two common ways for a news client to negotiate a TLS connection: either via the use of a dedicated port (usually 563) on which TLS is immediately negotiated upon connection, or via the now discouraged way (per RFC 8143) to use the STARTTLS command on the usual NNTP port (119) to dynamically upgrade from unencrypted to TLS-protected traffic during an NNTP session. innd does not, however, know how to listen for connections to that separate port (563). You will therefore need to arrange for nnrpd to listen on that port through some other means. This can be done with the -D flag along with "-p 563" and put into your init scripts:
su news -s /bin/sh -c '<pathbin>/nnrpd -D -p 563 -S'
but the easiest way is probably to add a line like:
nntps stream tcp nowait news <pathbin>/nnrpd nnrpd -S
to /etc/inetd.conf or the equivalent on your system and let inetd run nnrpd. (Change the path to nnrpd to match your installation.) You may need to replace "nntps" with 563 if "nntps" isn't defined in /etc/services on your system.
Optionally, you may set the tlsciphers, tlsciphers13, tlscompression, tlseccurve, tlspreferserverciphers, and tlsprotocols parameters in inn.conf to fine-tune the behaviour of the TLS/SSL negotiation whenever a new attack on the TLS protocol or some supported cipher suite is discovered.
nnrpd implements the NNTP commands defined in RFC 3977 (NNTP), RFC 4642 updated by RFC 8143 (TLS/NNTP), RFC 4643 (NNTP authentication), RFC 6048 (NNTP LIST additions) and RFC 8054 (NNTP compression) with the following differences:
Note that LIST NEWSGROUPS should be used instead of XGTITLE.
Note that HDR should be used instead of XHDR.
Note that OVER should be used instead of XOVER.
Written by Rich $alz <rsalz@uunet.uu.net> for InterNetNews. Overview support added by Rob Robertston <rob@violet.berkeley.edu> and Rich in January, 1993. Exponential backoff (for posting) added by Dave Hayes in Febuary 1998.
$Id: nnrpd.pod 10301 2018-11-11 14:42:17Z iulius $
ctlinnd(8), innd(8), inn.conf(5), readers.conf(5), signal(2), uwildmat(3).
2018-12-02 | INN 2.6.3 |