nnrpd - NNTP server for reader clients
] [-4 address
] [ -b address
] [ -c configfile
] [-I instance
] [ -p
] [ -P prefork
] [-r reason
is an NNTP server for newsreaders. It accepts commands on its
standard input and responds on its standard output. It is normally invoked by
(8) with those descriptors attached to a remote client connection.
also supports running as a standalone daemon.
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
only reads config files (both readers.conf
) when it is spawned. You can therefore never change the
behavior of a client that's already connected. If nnrpd
is run from
(the default) or from inetd
(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
option, any configuration changes won't take effect until
can be used to pass any of the
options below to instances of nnrpd
that are spawned directly from
. Many options only make sense when -D
is used, so these
options should not be used with nnrpdflags
. See also the discussion of
is not 0, it will also reject
connections if the load average is greater than that value (typically 16).
can also prevent high-volume posters from abusing your resources.
See the discussion of exponential backoff in inn.conf
- -4 address
- The -4 parameter instructs nnrpd to bind to
the specified IPv4 address when started as a standalone daemon using the
-D flag. This has to be a valid IPv4 address belonging to an
interface of the local host. It can also be 0.0.0.0, saying to bind to all
addresses (this is the default).
- -6 address
- The -6 parameter instructs nnrpd to bind to
the specified IPv6 address when started as a standalone daemon using the
-D flag. This has to be a valid IPv6 address belonging to an
interface of the local host. It can also be "::0", saying to
bind to all IPv6 addresses.
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.
- -b address
- Similar to the -4 flag. -b is kept for
- -c configfile
- By default, nnrpd reads the readers.conf to
determine how to authenticate connections. The -c flag specifies an
alternate file for this purpose. If the file name isn't fully qualified,
it is taken to be relative to pathetc in inn.conf. (This is
useful to have several instances of nnrpd running on different
ports or IP addresses with different settings.)
- If specified, this parameter causes nnrpd to operate
as a daemon. That is, it detaches itself and runs in the background,
forking a process for every connection. By default, nnrpd listens
on the NNTP port (119), so either innd(8) has to be started on
another port or the -p parameter used. Note that with this
parameter, nnrpd continues running until killed. This means that it
reads inn.conf once on startup and never again until restarted.
nnrpd should therefore be restarted if inn.conf is changed.
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 specified, nnrpd does not detach itself and runs
in the foreground when started as a standalone daemon using the -D
- -i initial
- Specify an initial command to nnrpd. When used,
initial is taken as if it were the first command received by
nnrpd. After having responded, nnrpd will close the
- -I instance
- If specified, instance is used as an additional
static portion within message-IDs generated by nnrpd; typically
this option would be used where a cluster of machines exist with the same
virtual hostname and must be disambiguated during posts.
- The -n flag turns off resolution of IP addresses to
names. If you only use IP-based restrictions in readers.conf and
can handle IP addresses in your logs, using this flag may result in some
- The -o flag causes all articles to be spooled
instead of sending them to innd(8). rnews with the -U
flag should be invoked from cron on a regular basis to take care of these
articles. This flag is useful if innd(8) is accepting articles and
nnrpd is started standalone or using inetd(8).
- -p port
- The -p parameter instructs nnrpd to listen on
port when started as a standalone daemon using the -D
- -P prefork
- The -P parameter instructs nnrpd to prefork
prefork children awaiting connections when started as a standalone
daemon using the -D flag.
- -r reason
- If the -r flag is used, then nnrpd will
reject the incoming connection giving reason as the text. This flag
is used by innd(8) when it is paused or throttled. reason
should be encoded in UTF-8.
- -s padding
- As each command is received, nnrpd tries to change
its "argv" array so that ps(1) will print out the command
being executed. To get a full display, the -s flag may be used with
a long string as its argument, which will be overwritten when the program
changes its title.
- If specified, nnrpd will start a negotiation for a
TLS session as soon as connected. To use this flag, the OpenSSL SSL and
crypto libraries must have been found at configure time, or
--with-openssl specified at configure time. For more information on
running nnrpd with TLS support, see "TLS SUPPORT".
- If the -t flag is used, then all client commands and
initial responses will be traced by reporting them in syslog. This flag is
set by innd(8) under the control of the ctlinnd(8)
"trace" command, and is toggled upon receipt of a SIGHUP; see
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:
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
program will ask you a variety of questions about your
organization. Enter the fully qualified domain name of the server as the name
the certificate is for.
You then have to set these inn.conf
parameters with the right paths:
In case you have a certificate authority root certificate, you can also set
to its path.
There are two common ways for a news client to negotiate a TLS connection:
either via the use of the STARTTLS command on the usual NNTP port (119) or via
the now discouraged way (per RFC 4642) to immediately negotiate an encrypted
session upon connection on a dedicated port (usually 563). As most news
clients currently do not use the STARTTLS command, and instead expect to
connect to a separate port (563) and start a TLS negotiation immediately, it
is still useful to provide a legacy way for these news clients to encrypt the
NNTP session. innd
does not, however, know how to listen for
connections to that separate port. You will therefore need to arrange for
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
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
or the equivalent on your system and let inetd
. (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
, 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.
implements the NNTP commands defined in RFC 3977 (NNTP),
RFC 4642 (TLS/NNTP), RFC 4643 (NNTP authentication) and
RFC 6048 (NNTP LIST additions) with the following differences:
- The XGTITLE [wildmat] command is provided. This
extension is used by ANU-News and documented in RFC 2980. It
returns a 282 reply code, followed by a one-line description of all
newsgroups that match the pattern. The default is the current group.
Note that LIST NEWSGROUPS should be used instead of XGTITLE.
- The XHDR header [message-ID|range]
command is implemented. It returns a 221 reply code, followed by specific
headers for the specified range; the default is to return the data for the
current article. See RFC 2980.
Note that HDR should be used instead of XHDR.
- The XOVER [range] command is provided. It returns a
224 reply code, followed by the overview data for the specified range; the
default is to return the data for the current article. See
Note that OVER should be used instead of XOVER.
- A new command, XPAT header
message-ID|range pattern [ pattern ...], is
provided. The first argument is the case-insensitive name of the header to
be searched. The second argument is either an article range or a single
message-ID, as specified in RFC 2980. The third argument is a
uwildmat(3)-style pattern; if there are additional arguments, they
are joined together separated by a single space to form the complete
pattern. This command is similar to the XHDR command. It returns a 221
response code, followed by the text response of all article numbers that
match the pattern.
- A newsgroup name is case-sensitive for nnrpd.
- If IHAVE has been advertised, it will not necessarily be
advertised for the entire session (contrary to section 3.4.1 of
RFC 3977). nnrpd only advertises the IHAVE capability when
it is really available.
- nnrpd allows a wider syntax for wildmats and ranges
(especially "-" and "- article-number").
Written by Rich $alz <firstname.lastname@example.org> for InterNetNews. Overview
support added by Rob Robertston <email@example.com> and Rich in
January, 1993. Exponential backoff (for posting) added by Dave Hayes in
$Id: nnrpd.pod 10064 2016-09-04 12:55:40Z iulius $