< inndstart | Russ Allbery > Software > INN > INN 2.4 Documentation | rc.news > |
(NNTP server for reader clients)
nnrpd [-DfnoSt] [-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 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).
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.)
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 listen on
(119 unless the -p option is given).
If specified, nnrpd does not detach itself and runs in the foreground 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
standalone mode. On many systems, members of that group have read
permission 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_GETSPNAM
in include/config.h is defined and nnrpd is
running in standalone mode since this call only works when nnrpd is
started as root.
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.
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 additional speed.
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 standalone 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 awaiting connections when started as a standalone daemon using the -D flag.
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.
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 SSL session as
soon as connected. To use this flag, --with-openssl
must have been
specified at configure
time.
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 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 /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 following differences:
The slave
command is not implemented. This command has never been
fully defined.
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 overview.fmt file.
The command list active
is equivalent to the list
command. This
is a common extension.
The xhdr
, authinfo user
and authinfo pass
commands are
implemented. These are based on the reference Unix implementation. See
RFC 2980.
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.
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 article numbers in the
group.
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.
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.
The xpath MessageID
command is provided; see innd(8).
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 <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.
$Id$
ctlinnd(8), innd(8), inn.conf(5), signal(2), uwildmat(3).
< inndstart | Russ Allbery > Software > INN > INN 2.4 Documentation | rc.news > |