
Leafnode FAQ

Dr. Cornelius Krasel

Matthias Andree

   $Id: FAQ.xml,v 1.12 2002/11/10 20:21:22 emma Exp $

   Copyright © 2002 Cornelius Krasel, Matthias Andree

   $Date: 2002/11/10 20:21:22 $
     _________________________________________________________________

   Table of Contents

   Leafnode frequently asked questions, with answers.

        Installation problems
        Configuration problems
        Problems at run time
        Problems with particular newsreaders
        License issues

   Obtaining a stack backtrace

        From a core file.
        Running a program under gdb supervision.
        From a running/hanging leafnode program.

   Red Hat and the inetd vs. xinetd issue.

Leafnode frequently asked questions, with answers.

Installation problems

   Q:. Leafnode does not compile on my system.

   Q:. 

   Leafnode does not compile on my system.
   A:. 

   Apple MacOS X/Darwin. Apple introduced Two-Level Namespace Executables
   with MacOS X 10.1. This change affects how the linker works, and the
   linker itself is driven by the libtool parts that ship with PCRE.
   libtool as of that version and up to version 1.4.2 does not yet
   support the new linker semantics of MacOS X 10.1, and the compile
   broke up to and including leafnode 1.9.27.

   Since leafnode 1.9.28, the embedded pcre/ directory contains two
   changes to overcome these problems:
    1. the embedded libtool parts in configureare patched to detect these
       new MacOS versions and pass appropriate options to the linker.
    2. When leafnode uses the embedded libtool, it passes the
       --disable-shared option to PCRE's configure, which avoids this
       trouble with shared libraries and speeds up the build -- leafnode
       will links statically anyhow to avoid the PCRE installation. The
       file configure.gnu does that, and it will not get applied if you
       explicitly configure pcre/.

   So, effectively, an update to leafnode 1.9.28 should fix this problem.
   If it does not, contact the leafnode mailing list.

   Linux. Another common reason for the build to fail is that Leafnode
   depends on some system-specific information which is usually included
   in the sources of the kernel.

   Unfortunately, some Linux distribution do not install kernel sources
   by default; therefore, compilation of Leafnode (and most other
   programs as well) will fail. The obvious solution is to install the
   kernel sources. On Linux, if the kernel sources are installed in
   /usr/src/linux-a.b.cc (with a.b.cc being the version number of your
   kernel), create a symlink to /usr/src/linux.

Configuration problems

   Q:. Leafnode refuses to start and tells things about my hostname!
   Q:. Does leafnode support local newsgroups?
   Q:. How do I use fetchnews with NNTP/SSL servers, such as
          nntp.sourceforge.net?

   Q:. 

   Leafnode refuses to start and tells things about my hostname!
   A:. 

   There is a separate documentation file dedicated to this issue, how to
   obtain a hostname, and how to tell leafnode about it. Please see
   README-FQDN or README-FQDN.html for details.
   Q:. 

   Does leafnode support local newsgroups?
   A:. 

   Leafnode 1.x does not support local newsgroups. Leafnode 2.x will do
   that.
   Q:. 

   How do I use fetchnews with NNTP/SSL servers, such as
   nntp.sourceforge.net?
   A:. 

   Warning: SourceForge does not currently support the HEAD, STAT and
   BODY commands, so leafnode-1 is totally out of the play for now.
   leafnode-2 will work for lurking, but will likely be unable to post.
   Sourceforge are aware that we need these commands and will add them at
   a later time.
    1. Obtain stunnel and install it.
    2. Arrange for stunnel to be started at system boot time, try:
       /usr/sbin/stunnel -c -d 127.0.0.1:563 -r nntp.sourceforge.net:563
       Add
server = localhost
port = 563
username = YOUR_SF_LOGIN
password = TOP_SECRET
       to your /etc/leafnode/config.

Problems at run time

   Q:. I cannot post, leafnode tells me the Message-ID is invalid.
   Q:. I cannot connect to my newsserver.
   Q:. Remote users cannot connect to leafnode.
   Q:. Fetchnews does not fetch any articles.
   Q:. Fetchnews has problems retrieving new newsgroups.
   Q:. Since the update, fetchnews does not post any of my old articles!
   Q:. Since the update, fetchnews does not post my new articles!
   Q:. While fetchnews is running, my modem hangs up.
   Q:. How can I run fetchnews as regular user (not root)?
   Q:. I have unsubscribed from a newsgroup, but fetchnews still pulls
          articles for that group.

   Q:. Texpire does not expire articles.
   Q:. How do I stop fetchnews from unsubscribing from newsgroups?

   Q:. 

   I cannot post, leafnode tells me the Message-ID is invalid.
   A:. 

   Netscape Communicator, Mozilla and derived products (Beonex) will by
   default generate the Message-ID from the domain part of your E-Mail
   address. However, if your address is that of a big freemailer site
   (hotmail.com, yahoo.com, gmx.de), this will lead to invalid
   Message-IDs.

   To work around this, go to the Mail & Newsgroups settings and enclose
   your E-Mail addresses into double quote marks, like
   this:"matthias.andree@gmx.de"This will prevent your Netscape-based
   newsreader from generating the invalid Message-ID and leave the
   generation to leafnode.
   Q:. 

   I cannot connect to my newsserver.
   A:. 

   You may not have configured inetd or xinetd properly, or the
   corresponding super server is not running. Please review the
   installation instructions. See below for information specific to Red
   Hat.

   To test the setup, try: telnet localhost 119. Leafnode should then
   reply with (on one line):
200 Leafnode NNTP Daemon, version 1.9.27.rel running at merlin.emma.line.org
(my fqdn: merlin.emma.line.org)

   Q:. 

   Remote users cannot connect to leafnode.
   A:. 

   You are connecting from outside the same networks that your leafnode
   server is in. Leafnode by default refuses connections from outside
   your LAN to prevent your leafnode server from abuse should you forget
   to configure tcpd or make a mistake when writing your hosts.allow or
   hosts.deny files. Please see /etc/leafnode/config.example for the
   allowstrangers option and how to configure this option. You will have
   to change the capitalization and write a special number on that line
   as you put it into your /etc/leafnode/config.
   Q:. 

   Fetchnews does not fetch any articles.
   A:. 
     * You did not read any pseudo articles with your news reader.
       Subscribe to some groups, enter them and read the leafnode
       placeholder article.
     * Your groupinfo file may be corrupt. Run fetchnews -f.
     * /var/spool/news may have wrong permissions. /var/spool/news and
       all its subdirectories should be owned by user and group news and
       have permissions drwxrwsr-x (02755).

   Q:. 

   Fetchnews has problems retrieving new newsgroups.
   A:. 

   Maybe your upstream server supports neither the XGTITLE
   news.group.name nor the LIST NEWSGROUPS news.group.name command.

   In this case, add nodesc = 1 to the server entry in
   /etc/leafnode/config, as described in the leafnode(8) manual page and
   the /etc/leafnode/config.example file.
   Q:. 

   Since the update, fetchnews does not post any of my old articles!
   A:. 

   Go read the "incompatible changes" and "updating" sections in NEWS and
   README.
   Q:. 

   Since the update, fetchnews does not post my new articles!
   A:. 

   You have probably mixed old and new binaries. Check your inetd.conf or
   xinetd.conf configuration if they really point to the new binary.
   Q:. 

   While fetchnews is running, my modem hangs up.
   A:. 

   An article that causes the interruption may contain three plus signs
   in a row ("+++"), which many modems interpret as the beginning of a
   command. You can change or disable this "escape" sequence. Consult
   your modem's manual, register S2 is a common place to configure this.
   Q:. 

   How can I run fetchnews as regular user (not root)?
   A:. 

   For security reasons, this is not possible.

   However, there is a tool named "sudo" that allows a regular,
   unprivileged user to impersonate another user, and this can be used to
   enable a regular user to run fetchnews.

   "sudo" is available from http://www.courtesan.com/sudo/.

   If "sudo" is installed on your system, then run visudo as root and add
   this line:
username ALL = (news) NOPASSWD: /path/to/fetchnews

   Remember to replace "username" and "/path/to/" with the user's login
   and the proper path to fetchnews.

   Now, the user who has been enabled access to fetchnews can just type
   sudo -u news /path/to/fetchnews to run fetchnews.
   Q:. 

   I have unsubscribed from a newsgroup, but fetchnews still pulls
   articles for that group.
   A:. 

   Your news reader talks to leafnode via the NNTP protocol. This
   protocol provides no means for Leafnode to determine which newsgroups
   you are actually subscribe. Therefore, Leafnode assumes that a
   newsgroup that is not read for a certain time (which can be configured
   with the timeout_long parameter) is unsubscribed and will only stop
   retrieving articles in it after this time.

   If you are impatient and want to stop retrieving articles from that
   group immediately, delete the corresponding file in the
   /var/spool/news/interesting.groups/ directory. The articles that are
   already in your spool are still subject to the regular texpire
   schedule, however.
   Q:. 

   Texpire does not expire articles.
   A:. 

   The backup software that you are using may not reset the atime after
   reading a file. Check if you can reconfigure it to reset the "atime".

   As a workaround, run texpire -f. This will expire articles somewhat
   earlier because expiry is then determined from the time the file was
   last modified, rather than when it was last accessed.
   Q:. 

   How do I stop fetchnews from unsubscribing from newsgroups?
   A:. 

   Run fetchnews -n rather than just fetchnews.

Problems with particular newsreaders

   Q:. When searching news with Netscape, I only get back unknown
          command.

   Q:. Outlook Express locks up.
   Q:. Tin complains about a missing file /var/lib/news/active.

   Q:. 

   When searching news with Netscape, I only get back "unknown command".
   A:. 

   To search news, older versions of Netscape needed a news server which
   supports the XPAT command. Leafnode-1 does not. If you want to use
   Netscape, you have to upgrade to version 4.5 and press the "options"
   button which appears in the "search messages" window. In the box which
   appears you have to select "on your local system".
   Q:. 

   Outlook Express locks up.
   A:. 

   This can be caused by a corrupted inbox file in Outlook Express. It is
   said to happen during the initial install of Internet Explorer. To fix
   this problem, go to "Add/Remove Programs", choose "Internet Explorer",
   then "Repair installation."

   Thanks to Jim Gifford who talked to Microsoft to find this solution.
   Q:. 

   Tin complains about a missing file /var/lib/news/active.
   A:. 

   Either you have started the wrong version of tin (the one which tries
   to read news directly from the spool) or your groupinfo file is
   corrupt.

   In the first case, simply invoke tin with the -r flag: tin -r. If this
   does not help, try to rebuild the groupinfo file by running fetchnews
   -f.

License issues

   Q:. Why is Leafnode not licensed under the GPL?

   Q:. 

   Why is Leafnode not licensed under the GPL?
   A:. 

   There are several reasons:
     * Originally, Arnt Gulbrandsen licensed Leafnode under his own
       license:

     Use, modification and distribution is allowed without limitation,
     warranty, or liability of any kind.
       This license is very broad. The same spirit is (in my opinion)
       contained in the X11 license, which is used by Leafnode nowadays.
     * I (Cornelius) do not like the philosophy of the FSF. They seem to
       emphasize that every project they conceived is good whereas
       everything else is bad. If they cannot argue the software away
       this way, they claim it to be part of the project, such as calling
       Linux "GNU/Linux". Or, as Arnt Gulbrandsen put it:

     Freedom includes the freedom to disagree with me and still use my
     software.

Obtaining a stack backtrace

   This section will tell you how to obtain a stack backtrace, a special
   program state output that is very useful to somebody who is about to
   debug a crash.

   The prerequisite to work is that the program is not stripped, i. e. it
   contains the debug symbols. That means leafnode must have been
   installed with make install rather than make install-strip. Note that
   most packagers (for RPM at least) use make install-strip to save
   space.

   To find out if your leafnode installation has been stripped, type file
   /usr/local/sbin/leafnode (adjust the path as necessary, packages will
   usually install to /usr/sbin/leafnode instead), here is a sample
   output of an unstripped program:
$ file /usr/local/sbin/leafnode
/usr/local/sbin/leafnode: ELF 32-bit LSB executable, Intel 80386, version 1,
dynamically linked (uses shared libs), not stripped

From a core file.

   This is simple:
    1. Type gdb PROGRAM core. Replace PROGRAM by the name of the program
       that crashed, for example fetchnews.
    2. Type backtrace full.
    3. Type quit.

Running a program under gdb supervision.

    1. Type gdb PROGRAM. Replace PROGRAM by the name of the program that
       crashes, for example fetchnews. Do not give any program options,
       gdb does not understand them here.
    2. Type run OPTIONS, where you name the options that you would
       normally pass to the program itself. Just a plain run is also
       fine.
    3. Wait until the program crashes. The output might look like similar
       to this:
This GDB was configured as "i686-pc-linux-gnu"...
(gdb) run -vvn

Starting program: /tmp/crashme

Program received signal SIGSEGV, Segmentation fault.
main () at crashme.c:4
4           *x = 4;
(gdb)
    4. Type backtrace full, this is the desired stack backtrace.
    5. Type quit to leave gdb.

From a running/hanging leafnode program.

    1. Find out the Process ID of the hanging leafnode program. Type ps
       axw | grep PROGRAM | grep -v grep on BSD systems and Linux,
       replacing PROGRAM by the name of the program. Use ps -ef instead
       on SysV systems such as Solaris.
       You will get an output like:
 1995 ?  S      0:00 /usr/local/sbin/leafnode
                               1995 is the Process ID.
    2. Then attach gdb: gdb PROGRAM 12345, replacing PROGRAM by the
       program's name and 12345 by the PID that you have just found out.
    3. Type backtrace full.
    4. Type detach.
    5. Type quit.

Red Hat and the inetd vs. xinetd issue.

William Hooper

   RedHat Linux has changed stance on inetd/xinetd over the years. In the
   6.x version, inetd was used, while xinetd is used in the 7.x series
   and 8.0. Note in the following I make the assumption that the "Gnome
   workstation" and "KDE workstation" installs are the same in regard to
   our discussion. Also, when in doubt a simple rpm -qa | grep inetd will
   show you if either inetd or xinetd is installed. The service and
   chkconfig commands can be used to be sure [x]inetd is running and
   configured to run at boot time. By default, runlevels 3, 4, and 5
   start [x]inetd.

   Beginning with Redhat 6.2, inetd was broken out as a separate RPM and
   not included when doing a "Workstation" install. This stands true for
   the 7.x series (xinetd not installed) until 7.3. In Redhat 7.3, xinetd
   was added back to the "Workstation" install as a dependency for
   "sgi_fam". Note, this change is not reflected in the RH documentation,
   which states that xinetd is not installed in "Workstation" installs.

   In Redhat 8.0, the install options have changed, now offering a
   "Personal Desktop" install. When doing a "Workstation" or "Personal
   Desktop" install xinetd is installed as in 7.3, presumably to satisfy
   the same dependency.

   In cases where inetd is not installed, no other RPMs are required to
   install it. This means to install it you have three options (for
   RedHat 6.2 substitute inetd instead of xinetd):
    1. Best - If you have registered for Redhat's up2date service, just
       type "up2date xinetd" as root.
    2. Next Best - Install RPM from updates.redhat.com (version numbers
       current as of 2002-11-10 for RH 7.3). You can manually download
       the RPM and install it (as root) using rpm -ivh
       xinetd-2.3.9-0.73.i386.rpm, or have RPM download it for you by
       using (again, as root) rpm -ivh
       http://updates.redhat.com/7.3/en/os/i386/xinetd-2.3.9-0.73.i386.rp
       m
    3. Worse - Install the RPM from the original CD. This is usually the
       worse option because the updates (used above) are released to fix
       security issues.
       (All as root) First mount the first RH CD by putting it in the
       CD-ROM and doing a mount /mnt/cdrom, and install the RPM similar
       to this: cd /mnt/cdrom/Redhat/RPMS/xinetd-2.3.7-2.i386.rpm.
