NNRPD(8) InterNetNews Documentation NNRPD(8)
nnrpd - NNTP server for reader clients
nnrpd [-DfnoRSt] [-b address] [-c configfile] [-g shadowgroup>] [-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 read-
ing 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.
When nnrpdloadlimit in inn.conf is not 0, it will also reject connec-
tions 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).
The -b parameter instructs nnrpd to bind to the specified IP
address when started as a standalone daemon using the -D flag. This
has to be a valid IPv4 or IPv6 address belonging to an interface of
the local host. It can also be ::0 (although the default is
0.0.0.0 if unspecified).
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.)
-D 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
nnrpd -p parameter. 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-%d.pid,
where %d is replaced with the port that nnrpd is configured to lis-
ten on (119 unless the -P option is given).
-f If specified, nnrpd does not detach itself and runs in the fore-
ground when started as a standalone daemon using the -D flag.
On systems that have a shadow password file, nnrpd tries to add the
group shadow as a supplementary group if it is running in stan-
dalone mode. On many systems, members of that group have read per-
mission for the shadow password file. The -g parameter instructs
nnrpd to try to add the named group as a supplementary group on
shadow systems instead of shadow. This only works if "HAVE_GETSP-
NAM" in include/config.h is defined and nnrpd is running in stan-
dalone mode since this call only works when nnrpd is started as
Specify an initial command to nnrpd. When used, initial is taken as
if it were the first command received by nnrpd.
If specified instance is used as an additional static portion
within MessageIDs 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.
-n 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 addi-
-o 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) in accepting articles and nnrpd is started stan-
dalone or using inetd(8).
The -p parameter instructs nnrpd to listen on port when started as
a standalone daemon using the -D flag.
The -P parameter instructs nnrpd to prefork prefork children await-
ing connections when started as a standalone daemon using the -D
If the -r flag is used, then nnrpd will reject the incoming connec-
tion giving reason as the text. This flag is used by innd(8) when
it is paused or throttled.
-R This option forces nnrpd to be read-only. The startup banner will
indicate "no posting".
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
-S If specified, nnrpd will start a negotiation for SSL session as
soon as connected. To use this flag, "--with-openssl" must have
been specified at "configure" time.
-t 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 signal(2).
If INN is built with "--with-openssl", nnrpd will support news reading
over TLS (also known as SSL). For clients that use the STARTTLS com-
mand, no special configuration is needed beyond creating a TLS/SSL cer-
tificate 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 /usr/local/news/lib/cert.pem \
-days 366 -keyout /usr/local/news/lib/key.pem
chown news:news /usr/local/news/lib/cert.pem
chmod 640 /usr/local/news/lib/cert.pem
chown news:news /usr/local/news/lib/key.pem
chmod 600 /usr/local/news/lib/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 the server as
the name the certificate is for.
Most news clients currently do not use the STARTTLS command, however,
and instead expect to connect to a separate port (563) and start an SSL
negotiation immediately. innd does not, however, know how to listen
for connections to that port and then spawn nnrpd the way that it does
for regular reader connections. 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 (and "-P 563"), but the easiest way is probably
to add a line like:
nntps stream tcp nowait news /usr/lib/news/bin/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 if
needed.) You may need to replace "nntps" with 563 if "nntps" isn’t
defined in /etc/services on your system.
nnrpd implements the NNTP commands defined in RFC 977, with the follow-
1. The "slave" command is not implemented. This command has never
been fully defined.
2. The "list" command may be followed by the optional word
"active.times", "distributions", "distrib.pats", "moderators",
"newsgroups", "subscriptions", or "Ioverview.fmt" to get a list of
when newsgroups where created, a list of valid distributions, a
file specifying default distribution patterns, moderators list, a
one-per-line description of the current set of newsgroups, a list
of the automatic group subscriptions, or a listing of the
The command "list active" is equivalent to the "list" command. This
is a common extension.
3. The "xhdr", "authinfo user" and "authinfo pass" commands are imple-
mented. These are based on the reference Unix implementation. See
4. A new command, "xpat header range│MessageID pat [morepat...]", 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 977. 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.
5. The "listgroup group" command is provided. This is a comment
extension. It is equivalent to the "group" command, except that
the reply is a multi-line response containing the list of all arti-
cle numbers in the group.
6. The "xgtitle [group]" command is provided. This extension is used
by ANU-News. It returns a 282 reply code, followed by a one-line
description of all newsgroups thatmatch the pattern. The default
is the current group.
7. 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.
8. The "xpath MessageID" command is provided; see innd(8).
9. The "date" command is provided; this is based on the draft NNTP
protocol revision (draft-ietf-nntpext-imp-04.txt). It returns a
one-line response code of 111 followed by the GMT date and time on
the server in the form "YYYYMMDDhhmmss".
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 Febuary 1998.
$Id: nnrpd.8,v 22.214.171.124 2004/12/19 20:52:21 rra Exp $
ctlinnd(8), innd(8), inn.conf(5), signal(2), uwildmat(3).
INN 2.4.2 2004-12-19 NNRPD(8)
Man(1) output converted with