                              pdnsd Documentation                              
                                                                               
This is the "official" pdnsd documentation and reference.
It is up-to-date for version 1.1.0b1. For older documentation, please refer to
the doc directory of the respective pdnsd package.
A pdnsd HOWTO ("unofficial" step-by-step installation and setup instructions)
is available at http://www.geocities.com/sunil_tt/.

0. Installation

0.1 Installing binary RPM's

To install a binary RPM, just do
rpm -i pdnsd-<version>.rpm
This should install pretty much everything automatically. The only thing left
for you to do is adatpt your configuration file (stored in /etc/pdnsd.conf)
according to your needs (see below). In the SuSE RPMs, a start script is also
installed; read the section 0.4, Start at Boot Time about that.

0.2 Installing source RPM's

To install a source RPM, just do
rpm --recompile pdnsd-<version>.rpm
This should install pretty much everything automatically. The only thing left
for you to do is adapt your configuration file (stored in /etc/pdnsd.conf)
according to your needs. In the SuSE RPMs, a start script is also installed;
read the section Start at Boot Time about that.

0.3 Installing from the pure sources (tar archives)

0.3.1 Decompressing

pdsnsd comes in two different packed archives: the standard gzip'ed version
pdnsd-<version>.tar.gz, and the bzip2-packed version (about 10% smaller) pdnsd-
<version>.tar.bz2. If you have bunzip2 installed on your computer, I recommed
you save bandwidth and get the .bz2-version. To decompress it (using a modern
tar) do
tar -xzf pdnsd-<version>.tar.gz
--or--
tar -xIf pdnsd-<version>.tar.bz2

If your tar doesn't do this, use:
gunzip pdnsd-<version>.tar.gz
tar -xf pdnsd-<version>.tar
--or--
bunzip2 pdnsd-<version>.tar.bz2
tar -xf pdnsd-<version>.tar

0.3.2 Setup

Change into the pdnsd source directory and run configure. It takes the
following command line options (if you do not specify an option, defaults will
be used):

                         Specify the prefix directory. The pdnsd files are     
                         installed in subdirectories of the prefix, the pdnsd  
--prefix=dir             and pdnsd-ctl executables are for example installed in
                         the sbin subdirectory of the prefix. The default for  
                         this is /usr/local; you might want to set this to /usr
                         (using --prefix=/usr).                                
                                                                               
                         Specify the config directory. pdnsd expects its       
                         pdnsd.conf file to reside there if the -c option is   
--sysconfdir=dir         not given at startup. The default for this is the etc 
                         subdirectory of your prefix, e.g. /usr/local/etc if   
                         you did not specify a prefix. To set this e.g. to /   
                         etc, use --sysconfdir=/etc.                           
                                                                               
--with-distribution=     Specify target distribution (default=Generic; others: 
distro                   RedHat, SuSE, Debian)                                 
                         See below for the effect of these settings.           
                                                                               
                         Change compilation target platform (default:          
                         autodetect; others: Linux, BSD)                       
--with-target=platform   autodetect will attempt to detect whether you are     
                         using *BSD or Linux and should normally be sufficient.
                         If this does not work, try specifyning you system     
                         manually.                                             
                                                                               
                         Default directory for pdnsd cache (default=/var/cache/
--with-cachedir=dir      pdnsd)                                                
                         This setting can be changed via config file settings  
                         when pdnsd was built.                                 
                                                                               
                         Specifiy database manager to use for cacheing (default
--with-dbm=dbm           =native; others: gdbm)                                
                         Currently, only native will work.                     
                                                                               
                         Enable ISDN support                                   
                         This option will work only on Linux and may cause     
--enable-isdn            problems with 2.0.x or old 2.2.x kernels. You will    
                         need it for a proper if uptest under Linux for ISDN   
                         ppp devices.                                          
                                                                               
--disable-ipv4           Disable IPv4 networking support (default=enabled)     
                                                                               
                         Enable IPv6 networking support.                       
--enable-ipv6            If your OS does support IPv6 properly, you should be  
                         able to serve also IPv4 queries using this. Normally, 
                         this is disabled and you won't need it.               
                                                                               
--disable-ipv4-startup   Disable IPv4 on pdnsd startup by default (default=    
                         enabled)                                              
                                                                               
                         Enable IPV6 on pdnsd startup by default (default=     
                         IPv4). These options are only defaults, you can       
--enable-ipv6-startup    specify on the command line or in the config files    
                         which IP version will really be used. Normally, you   
                         won't need to change these.                           
                                                                               
--disable-udp-queries    Disable udp as query method. You shouldn't need to    
                         change this.                                          
                                                                               
--enable-tcp-queries     Enable the TCP as query method. This is seldom needed 
                         in normal usage.                                      
                                                                               
                         Specify the query method (default=udponly, others:    
                         tcpudp, tcponly) If you have enabled both udp and tcp 
--with-query-method=qm   queries, this lets you control which query method     
                         pdnsd will use ny default. tcpudp will try tcp first  
                         and back out to udp if tcp is not supported by the    
                         server; udponly and tcponly should be clear.          
                                                                               
--disable-tcp-server     Disable tcp server. This may cause problems with very 
                         large answers.                                        
                                                                               
                         Disable the UDP source address discovery.             
--disable-src-addr-disc  You need this only if you have trouble with messages  
                         saying "could not discover udp source address".       
                                                                               
--disable-poll           Disable poll(2) and use select(2) (default=enabled)   
                         You will normally not need this.                      
                                                                               
                         Disable new DNS RR types. This may cause problems with
                         some resolvers. The new types are RP, AFSDB, X25,     
--disable-new-rrs        ISDN, RT, NSAP, PX, GPOS, AAAA, LOC, EID, NIMLOC, SRV,
                         ATMA, NAPTR and KX. Most of these are seldomly needed,
                         but AAAA is essential when using IPv6.                
                                                                               
                         Enforce strict RFC 2181 compliance.                   
                         This will cause pdnsd to reject DNS answers with      
--enable-strict-rfc2181  incorrect timestamp settings (multiple RRs of the same
                         type and for the same domain with different TTLs).    
                         Normally not needed.                                  
                                                                               
                         Allow underscores (_) in domain names. This breaks RFC
--enable-underscores     compliance, but some sites use it for historical      
                         reasons because BIND used to support it.              
                                                                               
                         Specify random device; default: C Library random()    
                         PRNG                                                  
                         pdnsd uses (pseudo-) random numbers as query IDs for  
                         security reasons (this makes forging DNS answers more 
                         difficult). This option controls where pdnsd gets     
                         these from. The default is the C library random()     
                         function, which is relatively weak. You can specify a 
--with-random-device=    device like /dev/urandom here if you like; pdnsd will 
device                   read random numbers from it 16-bit-wise. /dev/urandom 
                         is present under Linux and most BSD derivates. You    
                         should not use /dev/random - it is more secure, but   
                         may block and delay pdnsd's answers for a long time.  
                         You can specify arc4random to use the BSD arc4random()
                         library function (default for FreeBSD target), which  
                         is considered safe.                                   
                         You can also specify random as device to use the C    
                         Library random() function (described above).          
                                                                               
                         Specify default user for pdnsd (default=nobody). This 
                         is the user that will be entered for the run_as option
--with-default-id=user   in the config file (see below) that will be installed 
                         during make install. You can change this any time in  
                         your config file.                                     
                                                                               
                         Specify debugging level. Debug output will only be    
--with-debug=level       generated if you turn on special switches; it might be
                         useful for debugginh your config files, so I recommend
                         using the default (9).                                
                                                                               
--with-verbosity=level   Specify default message verbosity. The default should 
                         be ok.                                                
                                                                               
                         Enable RCS IDs in executables (default=disabled).     
--enable-rcsids          For personal use, there is no need to do this. If you 
                         build rpm's, it might have advantages.                
                                                                               
                         Enable subsequent tcp queries. The DNS protocol       
                         standard requires that servers must be capable of     
                         answering multiple subsequent queries that are sent   
                         over the same tcp connection, and that the server may 
                         only close the connection by himself after a certain  
--enable-tcp-subseq      timeout. This feature is rarely used, but may make    
                         denial-of-service attacks easier, as it allows for an 
                         attacker to hold a connection open a long time        
                         (although the attacker's IP is most likely revealed   
                         then). For full standard compliance, you should use   
                         this option. If you do not use --enable-tcp-server, is
                         option is not honored.                                
                                                                               
                         Specify default tcp query timeout after which the     
                         connection is closed if no full query has been        
--with-tcp-qtimeout      received. The default is 30s. You can also change this
                         option at run time using th tcp_qtimeout config file  
                         option. If you do not use --enable-tcp-server, is     
                         option is not honored.                                
                                                                               
                         Specify the default number of queries that can be     
                         executed in parallel. You can also change this option 
--with-par-queries       at run time using th par_queries config file option.  
                         See the description of that option for an explanation 
                         of what it really does.                               
                         The default for this option is 2.                     

Normally, you will need only --prefix, --sysconfdir and --with-distribution. If
you specify your distribution using --with-distribution, this has the following
effects:

  * An rc script is copied in the appropriate localtion, which enables pdnsd to
    start at machine boot time (see 0.4)
  * Distribution-specific portions might be included in the generated
    pdnsd.spec file (only important if you want to build rpm archives
    yourself).

If you choose Generic, no rc script is installled, and a generic spec file is
generated.
Further instructions are in the INSTALL document in the pdsd source directory.
./configure --help will give you a list of all supported command line options.

0.3.3 Building & installing

Type make in the source directory. Should work by now.
To install, type make install or do the installation by hand (see 0.3.4).
make install will do the following ($prefix is the prefix directory; see
above):

 1. copies pdnsd to $(prefix)/sbin/
 2. copies pdnsd-ctl to $(prefix)/sbin/
 3. copies docs/pdnsd.conf.sample (a sample configuration) to the pdnsd config
    directory.
 4. creates your cache directory if it is not there. After installation, you
    should check the file permissions and create or edit /etc/pdnsd.conf to fit
    your needs (see below). If you use the run_as option, please make sure that
    your cache directory is owned by the user you specified with this option!

You must be root for this installation!
Security notes: never make the pdnsd cache directory writeable for untrusted
users, or you will get several security holes: the users might modify the cache
contents, or plant dangerous links.
If you use a pidfile, you should be aware that you introduce security problems
if you place the pidfile in a directory in a NFS filesystem that is writeable
for untrusted users. Generally, the pidfile directory (typically /var/run)
should not be writeable for untrusted users.

0.3.4 Manual installation

For a manual installation, you need to do the following steps:

 1. Copy pdnsd and pdnsd-ctl from your build directory to an appropriate
    location (e.g. /usr/sbin).
 2. Copy docs/pdnsd.conf into the directory you want it to reside (/etc by
    default, and change it according to your needs (see below).
 3. Create your caching directory; default is /var/cache/pdnsd (you may change
    this in your pdnsd.conf); Permisions should be at max rwxr-xr-x (if you
    want to protect your cache and status socket, make it rwx------).

Thats it!

0.4 Start at boot time

In the rc folder of the pdnsd distribution are start scripts for pdnsd designed
for different Linux distros. There are scripts for SuSE and Redhat Linux now.
The start scripts are automatically installed during RPM install, and also
during make install if you specified your distro.

0.4.1 SuSE Linux startup

rc/SuSE/pdnsd is a start script for SuSE Linux. It was tested for 6.? but
should run on some versions below. You can do make install as root in the rc/
SuSE directory to install it, or you can install manually:

manual installation                                                            
                                                                               
For manual installation, copy rc/SuSE/pdnsd into /sbin/init.d/, go to /sbin/   
init.d/rc2.d/ and create there the following two symlinks:                     
S11pdnsd to ../pdnsd (do ln -s ../pdnsd S11pdnsd in that dir)                  
K34pdnsd to ../pdnsd (do ln -s ../pdnsd K34pdnsd in that dir)                  
The numbers dictate the order different services are started and might need to 
be modified. Then edit your /etc/rc.config file and add the line START_PDNSD=  
yes to start pdnsd at boot time.                                               

If you used the make install command, START_PDNSD=yes has been appended to your
/etc/rc.config file, causing pdnsd to be started at boot time. If you don't
want that, change the yes into no.

This start script was created from /sbin/init.d/skeleton by me, so the most is
copyrighted by SuSE. They put it under the GPL, however, so the license stated
in COPYING also applies to this script. There is NO WARRANTY OF ANY KIND on
these scripts. This is no official SuSE script, and SuSE naturally does NO
support for it.

0.4.2 Red Hat Linux startup

rc/Redhat/pdnsd is a start script for Red Hat Linux. It was contibuted by
Torben Janssen.
This was tested for 6.1 but should run on 5.0+. You can do make install as root
in the rc/Redhat directory to install it, or you can install manually:

manual installation                                                            
                                                                               
For manual installation, copy rc/Redhat/pdnsd into /etc/rc.d/init.d/           
Then go to /etc/rc.d/rc3.d and create there the following symlink:             
S78pdnsd -> ../init.d/pdnsd (do ln -f -s ../init.d/pdnsd S78pdnsd in that dir) 
Then go to /etc/rc.d/rc0.d and create there the following symlink:             
K78pdnsd -> ../init.d/pdnsd (do ln -f -s ../init.d/pdnsd K78pdnsd in that dir) 
Then go to /etc/rc.d/rc6.d and create there the following symlink:             
K78pdnsd -> ../init.d/pdnsd (do ln -f -s ../init.d/pdnsd K78pdnsd in that dir) 

This script is also covered by license stated in COPYING. Again, there is NO
WARRANTY OF ANY KIND on these scripts. This is no offical Redhat script, and
Redhat naturally does NO support for it

0.5 Notes for FreeBSD users

The special handling of ISDN ppp devices is only supported on Linux. It is not
needed in FreeBSD, the normal device handling also works fine with isdn4bsd
devices.
When compiled for FreeBSD, pdnsd as a small RFC compatability issue: RFC2181
demands answers on dns querys to be sent with the same source address the query
packet went to. In seldom cases, this will not be the case, because the kernel
selects the source address dependig on the interface that was used for sending
the answer.
Setting the source address currently does not work for IPv4. I have written a
kernel patch that will provide an easy way to program this. We'll see if or
when it gets commited.



1 Invocation

When invoking pdnsd, you can specify various options at the command line.
Command line options always override config file options. The various --noX
options are present to override config file options.

pdnsd --help (or -h) gives you an overview of the pdnsd command line options.

pdnsd --version (or -V for short) prints licence and version information.

To start pdnsd as background daemon, specifiy --daemon (or -d for short) on the
command line. Diagnostic and error messages after the actual daemon start will
be printed to the syslog instead of the console. --nodaemon will disable this.

When starting pdnsd as a daemon, the -p option may be helpful: It writes the
pid of the server process to the file of the name given as argument to this
option.
Example: pdnsd -d -p /var/run/pdnsd.pid

If you want to specify a configuration file other that /etc/pdnsd.conf, specify
-c or --config-file on the command line, followed by a filename.

If pdnsd was compiled with debugging options enabled, you may specify -g or 
--debug on the command line. This will cause extra diagnostic messages to be
printed. When pdnsd runs in deamon mode, the messages will be written to the
pdnsd.debug file in your cache directory. --nodebug disables debugging.

pdnsd -vn sets the verbosity level of pdnsd. n may be a digit from 0 to 3,
where 0 means normal operation, while 3 will most verbose. Example is -v2

The option -s or --status enables the status pipe. This is a named pipe in the
server directory called status. You can read the server status by doing
cat <your cache directory>/status. --nostatus disables the status pipe.

The option -t or --notcp disables the seldom needed TCP server thread, which
may save you some resources. --tcp will enable it.

Using the -m option, you can select the method pdnsd uses to query other name
servers. Following methods are supported:
-muo: pdnsd will use UDP only. This is the fastest method, and should be
supported by all name servers on the internt.
-mto: pdnsd will use TCP only. TCP queries usually take longer time than UDP
queries, but are more secure against certain attacks, where an attacker tries
to guess your query id and to send forged answers. TCP queries are not
supported by some name servers.
-mtu: pdnsd will try to use TCP, and will fall back to UDP if its connection is
refused.

2 The configuration file

This section describes the layout of the configuration file and the available
configuration options. The default location of the file is /etc/pdnsd.conf.
This may be changed with the -c command line option. An example pdnsd.conf
comes with the pdnsd distribution in the docs directory and will be installed
to /etc/ by make install.

2.1 Layout

The configuration file is divided into sections. Each section is prefixed with
the section name and opening curlies ({) and closed with closing curlies (}).
In each section, configuration options can be given in the form
option_name=option_value;
Option value may be a string literal (enclosed in "), a number or a constant.
Constants are noted in the section description in <> signs, but are written in
the file without these signs. Some options take more than one value; in this
case, the values are separated with commas.
If you may supply one of a set of possible values to an option, this is noted
in the documentation as
(option1|option2|option3|...)
Comments may be onclosed in /* and */, nested comments are possible. If the #
sign or two slashes (//) appear in the configuration file, everything from
these signs to the end of the current line is regarded as a comment and
ignored.
There are examples for nearly all options in the sample config file.

2.1.1 global Section

The global section specifies parameters that affect the overall behaviour of
the server. If you specify multiple global sections, the settings of those
later in the file will overwrite the earlier given values.
These are the possible options:


perm_cache=(number|<off>);                                                     
Switch the disk cache off or supply a maximum cache size in kB. If the disk    
cache is switched off, 4 bytes will still be written to disk. The memory cache 
is always 10kB larger than the file cache. This value is 2048 (2 MB) by        
default.                                                                       
                                                                               
cache_dir=string;                                                              
Set the directory you want to keep the cache in. The default is "/var/cache/   
pdnsd".                                                                        
                                                                               
server_port=number;                                                            
Set the server port. This is especially useful when you want to start the      
server and are not root. Note that you may also not specify uptest=ping in the 
server section as non-root.                                                    
The default port is 53, the RFC-standard one. Note that you should only use    
non-standard ports when you only need clients on your machine to communicate   
with the server; others will probably fail if the try to contact the server on 
the basis of an NS record, since the A record that supplies the address for    
(among others) name servers does not have a port number specification.         
                                                                               
server_ip=string;                                                              
Set the ip address pdnsd listens on for requests. This can be useful when the  
host has several interfaces and you want pdnsd not to listen on all interfaces.
Addtionally, it is possibly to bind pdnsd to listen on 127.0.0.2 to allow pdnsd
to be a forwarder for BIND. pdnsd will listen on all of your local interfaces  
by default. The ip is treated as string and therefore needs to have quotation  
marks around it.                                                               
                                                                               
linkdown_kluge=(<on>|<off>);                                                   
This option enables a kluge that some people might need: when all servers are  
marked down, with this option set the cache is not even used when a query is   
received, and a DNS error is returned in any case. The only exception from this
is that local records (as specified in rr and source sections are still served 
normally. In general, you probably want to get cached entries even when the    
network is down, so this defaults to off.                                      
                                                                               
max_ttl=number;                                                                
This options sets the maximum time a record is hold in cache in seconds. All   
dns resource records have a time to live field that says for what period of    
time the record may be cached before it needs to be requeried. If this is more 
than the value given with max_ttl, this time to live value is set to max_ttl.  
This is done to prevent records from being cached an inappropriate long period 
of time, because that is almost never a good thing to do. Default is 604800s   
(one week).                                                                    
                                                                               
min_ttl=number;                                                                
This options sets the minimum time a record is hold in cache in seconds. All   
dns resource records have a time to live field that says for what period of    
time the record may be cached before it needs to be requeried. If this is less 
than the value given with min_ttl, this time to live value is set to min_ttl.  
Default is 120 seconds.                                                        
                                                                               
neg_ttl=number;                                                                
This option sets the time that negative cached records will remain valid in the
cache if no time to live can be determined. This is always the case when whole 
domains are being cached negative, and additionally when record types are      
cached negative for a domain for which no SOA record is known to pdnsd. If a   
SOA is present, the ttl of the SOA is taken.                                   
                                                                               
neg_rrs_pol=(<on>|<off>|<auth>);                                               
This sets the RR set policy for negative cacheing; this tells pdnsd under which
circumstances it should cache a record type negative for a certain domain. off 
will turn the negative cacheing of record types off, on will always add a      
negative cache entry when a name server did not return a record type we asked  
it for, and auth will only add such entries if the answer came from an         
authoritative name server for that domain. The preset is auth. This is normally
the right thing, as some cacheing servers behave strange.                      
                                                                               
neg_domain_pol=(<on>|<off>|<auth>);                                            
This is analogue to neg_rrs_pol for whole domain negative cacheing. The preset 
is on here, because I have not seen a cacheing server that will falsely claim  
that a domain does not exist. If you experience problems with false negatives, 
try setting this to auth.                                                      
                                                                               
run_as=string;                                                                 
This option allows you to let pdnsd change its user and group id after         
operations that needed privileges have been done. This helps minimize security 
risks and is therefore recommended. The supplied string gives a user name whose
user id and primary group id are taken.                                        
A little more details: after reading the config file, becoming a daemon (if    
specified) and starting the server status thread, the main thread changes its  
gid and uid, as do all newly created threads thereafter. By taking another uid 
and gid, those threads run with the privileges of the specified user. Under    
Linux and FreeBSD, the server status thread runs with the original privileges  
only when the strict_setuid option is set to off (see below, on by default),   
because these may be needed for exec uptests. The manager thread also retains  
its original privileges in this case. You should take care that the user you   
specify has write permissions on your cache file and status pipe (if you need a
status pipe). You should look out for error messages like "permission denied"  
and "operation not permitted" to discover permission problems.                 
                                                                               
strict_setuid=(<on>|<off>);                                                    
When used together with the run_as option, this option lets you specify that   
all threads of the program will run with the privileges of the run_as user.    
This provides higher security than the normal run_as option, but is not always 
possible. See the run_as option for further discussion.                        
This option is on by default.                                                  
Note that this option has no effect on Non-Linux systems.                      
                                                                               
paranoid=(<on>|<off>);                                                         
Normally, pdnsd queries all servers in recursive mode (i.e. instructs servers  
to query other servers themselves if possible, and to give back answers for    
domains that may not be in its authority), and accepts additional records with 
information for servers that are not in the authority of the queried server.   
This opens the possibility of so-called cache poisoning: a malicious attacker  
might set up a dns server that, when queried, returns forged additional        
records. This way, he might replace trusted servers with his own ones by making
your dns server return bad IP addresses. This option protects you from cache   
poisoning by rejecting additional records that do not describe domains in the  
queried servers authority space and not doing recursive queries any more. An   
exception to this rule are the servers you specify in your config file, which  
are trusted.                                                                   
The penalty is a possible performance decrease, in particular, more queries    
might be necessary for the same operation.                                     
You should also notice that there may be other similar security problems, which
are essentially problems of the DNS, i.e. any "traditional" server has them    
(the DNS security extensions solve these problems, but are not widely          
supported). One of this vulnerabilities is that an attacker may bombard you    
with forged answers in hopes that one may match a query you have done. If you  
have done such a query, one in 65536 forged packets will be succesful (i.e. an 
average packet count of 32768 is needed for that attack). pdnsd can use TCP for
queries, which has a slightly higher overhead, but is much less vulnerable to  
such attacks on sane operating systems. Also, pdnsd chooses random query ids,  
so that an attacker cannot take a shortcut. If the attacker is able to listen  
to your network traffic, this attack is relatively easy, though.               
This vulnerability is not pdnsd's fault, and is possible using any conventional
name server (pdnsd is perhaps a little more secured against this type of       
attacks if you make it use TCP).                                               
The paranoid option is off by default.                                         
                                                                               
scheme_file=string;                                                            
In addition to normal uptests, you may specify that some servers shall only be 
queried when a certain pcmcia-cs scheme is active (only under linux). For that,
pdnsd needs to know where the file resides that holds the pcmcia scheme        
information. Normally, this is either /var/lib/pcmcia/scheme or /var/state/    
pcmcia/scheme.                                                                 
                                                                               
status_ctl=(<on>|<off>);                                                       
This has the same effect as the -s command line option: the status control is  
enabled when on is specified.                                                  
                                                                               
daemon=(<on>|<off>);                                                           
This has the same effect as the -d command line option: the daemon mode enabled
when on is specified.                                                          
                                                                               
tcp_server=(<on>|<off>);                                                       
This has the same effect as the -t command line option: the tcp serving ability
is enabled when on is specified.                                               
                                                                               
pid_file=string;                                                               
This has the same effect as the -p command line option: you can specify a file 
that pdnsd will write its pid into when it starts in daemon mode.              
                                                                               
verbosity=number;                                                              
This has the same effect as the -v command line option: you can set the        
verbosity of pdnsd's messages with it. The argument is a number between 0 (few 
messages) to 3 (most messages).                                                
                                                                               
query_method=(<tcp_only>|<udp_only>|<tcp_udp>);                                
This has the same effect as the -m command line option. Read the documentation 
for the command line option on this. tcp_only corresponds to the to, udp_only  
to the uo and tcp_udp to the tu argument of the command line option.           
                                                                               
run_ipv4=(<on>|<off>);                                                         
This has the same effect as the -4 command line option: if on is specified,    
IPv4 support is enabled, and IPv6 support is disabled (if available). ff off is
specified, IPv4 will be disabled and IPv6 will be enabled. You can only use    
this option if you have compiled pdnsd with IPv4 as well as with IPv6 support. 
                                                                               
debug=(<on>|<off>);                                                            
This has the same effect as the -g command line option: the debugging messages 
are enabled when on is specified.                                              
                                                                               
ctl_perms=number;                                                              
This option allows you to set the file permissions that the pdnsd status       
control socket will have. These are the same as file permissions. The owner of 
the file will be the run_as user, or, if none is specified, the user who       
started pdnsd. If you want to specify the permissions in octal (as usual),     
don't forget the leading zero (0600 instead of 600!). To use the status        
control, write access is needed. The default is 0600 (only the owner may read  
or write).                                                                     
Please note that the socket is kept in the cache directory, and that the cache 
directory permissions might also need to be adjusted. Please ensure that the   
cache directory is not writeable for untrusted users.                          
                                                                               
proc_limit=number;                                                             
With this option, you can set a limit on the pdnsd threads that will be active 
simultaneously. If this number is exceeded, queries are queued and may be      
delayed some time. See also the procq_limit option.                            
The default for this option are 20 query threads will be active (plus 3 to 6   
threads that will always be present depending on your configuration).          
                                                                               
procq_limit=number;                                                            
When the query thread limit is exceeded, connection attempts to pdnsd will be  
queued. With this option, you can set the maximum queue length. If this length 
is also exceeded, the incoming queries will be dropped. That means that tcp    
connections will be closed and udp queries will just be dropped, which will    
probably cause the querying resolver to wait for an answer until it times out. 
See also the proc_limit option.                                                
The default for this option is 30.                                             
                                                                               
tcp_qtimeout=number;                                                           
This option sets a timeout for tcp queries. If no full query has been received 
on a tcp connection after that time has passed, the connection will be closed. 
The default is set using the --with-tcp-qtimeout option to configure.          
                                                                               
par_queries=number;                                                            
This option sets the maximum number of queries that will be executed in        
parallel, i.e. how many servers are simultaneously queried. This may speed up  
the query process if there are very slow servers to be quered (the first answer
we get will be taken), but it will also increase network and server load. 1 or 
2 are good values for this option. The default is set using the                
--with-par-queries option to configure.                                        
                                                                               
randomize_recs=(<on>|<off>);                                                   
If this option is turned on, pdnsd will randomly reorder the cached records of 
one type when creating an answer. This supports round-robin DNS schemes and    
increases fail safety for hosts with multiple IP addresses, so this is usually 
a good idea,                                                                   
On by default.                                                                 
                                                                               
query_port_start=number;                                                       
If given, defines the start of the port range used for queries of pdnsd. The   
value given must be >= 1024. The purpose of this option is to aid certain      
firewall configurations that are based on the source port. Please keep in mind 
that another application may bind a port in that range, so a stateful firewall 
using target port and/or process uid may be more effective. In case a query    
start port is given pdnsd uses this port as the first port of a specified port 
range (see query_port_end) used for queries. pdnsd will try to randomly select 
a free port from this range as local port for the query.                       
To ensure that there are enough ports for pdnsd to use, the range between      
query_port_start and query_port_end should be adjusted to at least (par_queries
* proc_limit). A higher value is highly recommended, because other applications
may also allocate ports in that range. If possible, this range should be kept  
out of the space that other applications usually use.                          
                                                                               
query_port_end=number;                                                         
Only used if query_port_start is given. Defines the last port of the range     
started by query_port_start used for querys by pdnsd. The default is 65535,    
which is also the maximum legal value for this option. For details see the     
description of query_port_start.                                               


2.1.2 server Section

Each server section specifies a name server that pdnsd should try to get
resource records or authoritative name server information from. The servers a
queried in the order of their appearance (or parallel to a limited extend). If
one fails, the next one is taken and so on.
You probably want to specify the dns server in your LAN, the caching dns server
of your internet provider or even one of the root servers using server records.
The supported options in this section are:


ip=string;                                                                     
Give the ip (the ip, _not_ the hostname) of the server. Must be specified.     
                                                                               
port=number;                                                                   
Give the port the remote name server listens on. Default is 53 (the official   
dns port)                                                                      
                                                                               
uptest=(<ping>|<none>|<if>);                                                   
Determine the method to check whether the server is available. Currently       
defined methods are:                                                           
                                                                               
  * ping: Send an ICMP_ECHO request to the server. If it doesn't respond in    
    timeout, it is regarded to be unavailable until the next probe.            
  * none: The server is p.d. up                                                
  * if: Check whether the interface (specified in the interface= option) is    
    existent, up and running. This currently works for all "ordinary" network  
    interfaces, interfaces that disappear when down (eg ppp?), and additionally
    for Linux isdn interfaces (as of kernel 2.2). Note that you need a /dev/   
    isdninfo device file (major#45, minor#255), or the isdn uptest will always 
    fail.                                                                      
  * dev and diald: Perform an if uptest, and, if that was succesful,           
    additionally check whether a program is running that has locked a given    
    (modem-) device. The needed parameters are an interface (specified as for  
    the if uptest, e.g. "ppp0") and a device relative to /dev (e.g. "modem" for
    /dev/modem specified using the device= option. pdnsd will then look for a  
    pid file for the given interface in /var/lock (e.g. /var/run/ppp0.pid) and 
    for a lockfile for the given device (e.g. /var/lock/LCK..modem), and then  
    test whether the locking process is the process that created the pid file  
    and this process is still alive. If this is the case, the normal if uptest 
    is executed for the given interface.                                       
    The dev option is for pppd dial-on-demand, diald is the same for diald     
    users.                                                                     
  * exec: Executes a given command in the /bin/sh shell (as /bin/sh -c         
    <command>) and evaluates the result (the retur code of the last command) in
    the shell's way of handling return codes, i.e. 0 indicates success, all    
    other indicate failure. The shell's process name will be uptest_sh. The    
    command is given with the uptest_cmd option (see below). For secuity       
    issues, also see that entry.                                               
                                                                               
The default value is none.                                                     
                                                                               
NOTE: If you use demand dialling, use none, if or exec, since ping will send   
packets in the specified interval and the interface will thus frequently dial! 
                                                                               
ping_timeout=number;                                                           
Sets the timeout for the ping test in tenth of seconds. The default is 600.    
                                                                               
ping_ip=string;                                                                
The ip for the ping test. The default is the ip of the name server.            
                                                                               
uptest_cmd=string,string;                                                      
or                                                                             
uptest_cmd=string;                                                             
Sets the command for the uptest=exec function to the first string. If the      
second string is given, it specifies a user with whose user id and primary     
group id the command is executed.                                              
This is especially useful if you are executing the server as root, but do not  
want the uptest to be performed with root privileges. In fact, you should never
execute the uptest as root if you can help it.                                 
If the server is running setuid or setgid, the privileges gained such are      
dropped even before changin identity to the specified user to prevent setuid/  
gid security holes (otherwise, any user might execute commands as root if you  
setuid the executable).                                                        
The command is executed using /bin/sh, so you should be able to use shell      
builtin commands.                                                              
                                                                               
interval=number;                                                               
Sets the interval for the server-up-test in seconds. The default is 900;       
however, a test is forced when a query times out. The interval timeout is reset
then.                                                                          
If you specify onquery instead of a timeout, the interface will be tested      
before every query. This is to prevent automatically dialling interfaces (diald
/pppd or ippp) to dial on dns queries. It is intended to be used in connection 
with a interface testing uptest ;-)                                            
Note that using uptest=exec, you might run into performance problems on slow   
machines when you use that option. DON'T use this option with ping, as it may  
cause delays if the server does not answer (btw, it doesn't make sense anyway).
Note also that using that option is no guarantee that the interface will not be
used. When another (reachable) dns server tells pdnsd to query a third dns     
server for data, pdnsd will do that and has no means of checking whether this  
will dial up the interface or not. This however should be a rare configuration.
                                                                               
interface=string;                                                              
The network interface (or network device, eg "eth0") for the uptest=if option. 
Must be specified if uptest=if is given.                                       
                                                                               
device=string;                                                                 
The (modem-) device that is used for the dev uptest. If you use this for a     
dial-on-demand ppp uptest (together with uptest=dev), you need to enter the    
device you are using for your pppd here, e.g. modem for /dev/modem.            
Must be specified if uptest=dev is given.                                      
                                                                               
timeout=number;                                                                
Set the timeout for the dns query in seconds. The default is 120. You probably 
want to set this lower.                                                        
                                                                               
purge_cache=(<on>|<off>);                                                      
In every fetched dns record, there is a cache timeout given, which specifies   
how long the fetched data may be cached until it needs to be reloaded. If      
purge_cache is set to no, the cached records are not purged (unless the cache  
size would be exceeded, in this case the oldest records are purged). Instead,  
they are still served if they cannot succesfully be updated (eg. because all   
servers are down).                                                             
                                                                               
caching=(<on>|<off>);                                                          
Specifies if caching shall be performed for this server at all. Default is on. 
                                                                               
lean_query=(<on>|<off>);                                                       
Specifies whether to use the "lean" query mode. In this mode, only the         
information actually queried from pdnsd is resolved and cached. This has the   
advantage that usually less cache space is used and the query is usually       
faster. In 90% of the cases, only address (A) records are needed anyway. If    
switched off, pdnsd will always cache all data about a host it can find and    
will specifically ask for all available records (well, at least it is a good   
approximation for what it really does ;-) This will of course increase the     
answer packet sizes.                                                           
Negative cacheing is only effective with lean_query activated.                 
Some buggy name servers may not deliver CNAME records when not asked for all   
records. I do not know if such servers are around, but if you have trouble     
resolving certain hostnames, try turning this option off.                      
A last note: If you use multiple pdnsd's that access each other, turning this  
option on is probably a big win.                                               
This on by default.                                                            
                                                                               
scheme=string;                                                                 
You can specify a pcmcia-cs scheme that is used in addition to the uptests. If 
you specify a scheme here, the server this section is for will only be queries 
if the given scheme is active. Shell wildcards (* and ?) are allowed in the    
string under their special meanings. You need to use the scheme_file option on 
the global section to make this option work.                                   
                                                                               
preset=(<on>|<off>);                                                           
This allows you to specify the initial state of a server before any uptest is  
performed. on specifies that the server is regarded available. The default is  
on. This is especially useful when you set uptest=none; and want to control a  
server only via pdnsd-ctl.                                                     
                                                                               
proxy_only=(<on>|<off>);                                                       
When this option is set to on, answers given by the servers are always         
accepted, and no other servers (as, for example, specified in the NS records of
the query domain) are queried. If you do not turn this option on, pdnsd will do
such queries in some cases (in particular when processing ANY queries).        
This option is useful when you do not want pdnsd to make connections to outside
servers for some reasons (e.g. when a firewall is blocking such queries).      
I recommend that you turn on lean_query when using this option.                
Default is off.                                                                
                                                                               
policy=(<included>|<excluded>);                                                
pdnsd supports inclusion/exclusion lists for server sections: with include= and
exclude= (see below) you can specifiy domain names for that this server will be
used or will not be used. The first match counts (i.e., the first include or   
exclude rule in a server section that matches a domain name is applied, and the
search for other rules is terminated). If no rule matched a given domain name, 
the policy= option determines whether this server is used for the lookup for   
that domain name; when included is given, the server will be asked, otherwise  
not.                                                                           
If no server is available for a queried domain, pdnsd will return an error     
message to the client that usually will stop the clients attempts to resolve a 
specific domain from this server (the libc resolver will e.g. return an error  
to the application that tried to resolve the domain if no other servers are    
available in the resolv.conf). This may be of use sometimes.                   
The default for this option is included.                                       
                                                                               
include=string;                                                                
This options adds an entry to the exclusion/inclusion list. If a domain matches
the name given as string, the server is queried if this was the first matching 
rule (see also the entry for policy).                                          
The domain name given must end in a dot. If it starts with a dot, the whole    
subdomain of the given name including the one of that name is matched, e.g.    
"foo.bar." will match the domain names a.foo.bar., a.b.c.foo.bar. and foo.bar. 
If it does not start in a dot, only exactly the given name (ignoring the case, 
of course) will be matched (hint: if you want to include all subdomains, but   
not the domain of the given name itself, place an exact-match exclude rule     
before the include rule, e.g: exclude="foo.bar."; include=".foo.bar.";         
                                                                               
exclude=string;                                                                
This options adds an entry to the exclusion/inclusion list. If a domain matches
the name given as string, the server is not queried if this was the first      
matching rule (see also the entry for policy).                                 
The domain name given must end in a dot. If it starts with a dot, the whole    
subdomain of the given name including the one of that name is matched, e.g.    
"foo.bar." will match the domain names a.foo.bar., a.b.c.foo.bar. and foo.bar. 
If it does not start in a dot, only exactly the given name (ignoring the case, 
of course) will be matched (hint: if you want to exclude all subdomains, but   
not the domain of the given name itself, place an exact-match include rule     
before the exclude rule, e.g: include="foo.bar."; exclude=".foo.bar.";         


2.1.3 rr Section

Every rr section specifies a dns resource record that is stored locally. It
allows you to specify own dns records that are served by pdnsd in a limited
way. Only PTR, A and SOA records are implemented.
This option is intended to allow you to define RRs for 1.0.0.127.in-addr.arpa.
and localhost. (and perhaps even one or two hosts) without having to start an
extra named if your cached name servers do not serve those records. It is NOT
intended and not capable to work as a full-featured name server.


name=string;                                                                   
Specifies the name of the resource records, i.e. the domain name of the        
resource the record describes. This option must be specified before any a, soa 
or ptr records. Only absolute domain names (names ending in the root domain, in
dotted notation ending with a dot) are allowed. For this and all following     
arguments that take domain names, you need to specify domain names in dotted   
notation (example venera.isi.edu.). Do not forget the dot at the end!          
                                                                               
owner=string;                                                                  
Specifies the name of the host pdnsd runs on and that is specified in dns      
answers (specifically, nameserver records). Must be specified before any a, ptr
and soa entries.                                                               
                                                                               
ttl=number;                                                                    
Specifies the ttl (time to live) for all resource records in this section after
this entry. This may be redefined. The default is 86400 seconds (=1 day).      
                                                                               
authrec=(on|off);                                                              
If this is turned on, pdnsd will create authoritative local records for this rr
section. This means that pdnsd flags the domain record so that records of this 
domain that are not present in the cache are treated as non-existent, i.e. no  
other servers are queried for that record type, and an response containing none
of those records is returned. This is most time what people want: if you add an
A record for a host, and it has no AAAA record (and no IPv6 address), you      
normally don't want other name servers to be queried for it.                   
This is on by default.                                                         
Please note that this only has an effect if it precedes the name and owner     
options!                                                                       
                                                                               
a=string;                                                                      
Defines an A (host address) record. The argument is an IP in dotted notation.  
pdnsd will serve this adrress for the hostname given in the name option.       
                                                                               
ptr=string;                                                                    
Defines a PTR (domain name pointer) record. The argument is a host name in     
dotted notation (see name). The ptr record is for resolving adresses into      
names. For example, if you want to have the adress 127.0.0.1 into localhost,   
and localhost into 127.0.0.1, you need something like the following sections:  
rr {                                                                           
owner="localhost.";                                                            
name="localhost.";                                                             
a="127.0.0.1";                                                                 
soa="localhost.","root.localhost.",42,86400,900,86400,86400;                   
}                                                                              
rr {                                                                           
owner="localhost.";                                                            
name="1.0.0.127.in-addr.arpa.";                                                
ptr="localhost.";                                                              
soa="localhost.","root.localhost.",42,86400,900,86400,86400;                   
}                                                                              
The second section is for reverse resolving and uses the ptr option. There is  
something special about the name in the second section: when a resolver wants  
to get a hostname from an internet address, it composes an adress that is build
of the IP address in reverse byte order (1.0.0.127 instead of 127.0.0.1) where 
each byte of the adress written as number constitutes a sub-domain under the   
domain in-addr.arpa.                                                           
So, if you want to compose an adress for reverse resolving, take your ip in    
dotted notation (eg 1.2.3.4), reverse the byte order (4.3.2.1) and append      
in-addr.arpa. (4.3.2.1.in-addr.arpa.) Then, define an rr section giving this   
address as name and the domain name corresponding to that ip in the ptr option.
                                                                               
soa=string,string,number,number,number,number,number;                          
This defines a soa (record source information) record. The first string is the 
domain name of the server and should be equal to the name you specified as     
owner.                                                                         
The second string specifies the email address of the maintainer of the name    
server. It is also specified as a domain name, so you will have to replace the 
@ sign in the name with a dot (.) to get the name you have to specify here. The
next parameter (the first number) is the serial number of the record. You      
should increment this number if you change the record.                         
The 4th parameter (the 2nd number) is the refresh timeout. It specifies after  
what amount of time a caching server should attempt to refresh the cached      
record.                                                                        
The 5th parameter specifies a time after which a caching server should attempt 
to refresh the record after a refresh failure.                                 
The 6th parameter defines the timeout after which a cached record expires if it
has not been refreshed.                                                        
The 7th parameter is the ttl that is specified in every rr and should be the   
same as given with the ttl option (if you do not specify a ttl, use the default
86400)                                                                         
All time parameters must be specified in seconds.                              


2.1.4 neg Section

Every neg section specifies a dns resource record or a dns domainthat should be
cached negative locally. Queries for negatively cached records are always
answered immediatley with an error or an empty answer without querying other
hosts as long as the record is valid. The record remains valid until it is
explicitely invalidated or deleted by the user using pdnsd-ctl.
This is useful if a certian application asks periodically for nonexisting hosts
or RR types and you do not want a query to go out every time the cached record
has timed out. Example: Netscape Communicator will ask for the servers news and
mail on startup if unconfigured. If you do not have a dns search list for your
network, you can inhibit outgoing queries for these by specifying
neg {
name="news.";
types=domain;
}
neg {
name="mail.";
types=domain;
}
in your config file. If you have a search list, you have to repeat that for any
entry in your search list in addition to the entries given above!


name=string;                                                                   
Specifies the name of the domain for which negative cache entries are created. 
This option must be specified before the types option. Only absolute domain    
names (names ending in the root domain, in dotted notation ending with a dot)  
are allowed. You need to specify domain names in dotted notation (example      
venera.isi.edu.). Do not forget the dot at the end!                            
                                                                               
ttl=number;                                                                    
Specifies the ttl (time to live) for all resource records in this section after
this entry. This may be redefined. The default is 86400 seconds (=1 day).      
                                                                               
types=(<domain>|rr_type[,rr_type[,rr_type[,...]]]);                            
Specifies what is to be cached negative: domain will cache the whole domain    
negatively; alternatively, you can specify a comma-separated list of RR types  
which are to be cached negatively. You may specify multiple types options, but 
domain and the RR types are mutually exclusive.                                
The RR types are specified using their official names from the RFC's in        
capitals, e.g. A, CNAME, NS, PTR, MX, AAAA, ...                                
The command pdnsd-ctl list-rrtypes will give you a complete list of those      
types. pdnsd-ctl is build along with pdnsd and will be installed in the same   
directory as the pdnsd binary during make install.                             


2.1.5 source Section

Every source section allows you to let pdnsd read the records from a file in an
/etc/hosts-like format. pdnsd will generate records to resolve the entries
address from its host name and vice versa for every entry in the file. This is
normally easier than defining an rr for every of your addresses, since
localhost and your other FQDNs are normally given in /etc/hosts.
The accepted format is as follows: The #-sign initiates a comment, the rest of
the line from the first occurence of this character on is ignored. Empty lines
are tolerated.
The first entry on a line (predeceded by an arbitrary number of tabs and
spaces) is the IP in dotted notation, the second entry on one line (separated
by the first by an arbitrary number of tabs and spaces) is the FQDN (fully
qualified domain name) for that ip. The rest of the line is ignored (in the
original /etc/hosts, it may contain information not needed by pdnsd).


owner=string;                                                                  
Specifies the name of the host pdnsd runs on and that are specified in dns     
answers (specifically, nameserver records). Must be specified before any file  
entries.                                                                       
Only absolute domain names (names ending in the root domain, in dotted notation
ending with a dot) are allowed. Example: venera.isi.edu.                       
                                                                               
ttl=number;                                                                    
Specifies the ttl (time to live) for all resource records in this section after
this entry. This may be redefined. The default is 86400 seconds (=1 day).      
                                                                               
file=string;                                                                   
The string specifies a file name. For every file entry in a source section,    
pdnsd will try to load the given file as described above. Failure is indicated 
only when the file cannot be opened, malformed entries will be ignored.        
                                                                               
serve_aliases=(on|off);                                                        
If this is turned on pdnsd will serve the aliases given in a hosts-style file. 
These are the third entry in a line of a hosts-style file, which usually give a
"short name" for the host. This may be used to support broken clients without a
proper domain-search option. If no aliases are given in a line of the file,    
pdnsd behaves as without this option for this line.                            
This feature was suggested by Bert Frederiks.                                  
It is off by default.                                                          
                                                                               
authrec=(on|off);                                                              
If this is turned on, pdnsd will create authoritative local records with the   
data from the hosts file. Please see the description of the option of the same 
name in the rr section for a closer description of what this means. Please note
that this only has an effect for files sourced with file options subsequent to 
this option.                                                                   


3 pdnsd-ctl

pdnsd-ctl allows you to run-time configure pdnsd. To make this work, you have
to start pdnsd with the -s option (or use the status_ctl option in the config
file). You also should make sure that you have appropriate permissions on the
control socket (use the ctl_perms option to make this sure) and of your pdnsd
cache directory (pdnsd keeps it's socket there). Please make sure the pdnsd
cache directory is not writeable for untrusted users!
pdnsd-ctl takes one optional command line argument, -c. It is used to specify
the cache directory (and takes this as argument). The default for this settings
is the pdnsd default cache directory (specified at compile time). The cache
directory for pdnsd-ctl must be the same pdnsd uses!
The following table lists the command line options that pdnsd-ctl supports. The
command must always be the first option, the options to the command must follow
in the given order.
In the following table, keywords are in a normal font, while placeholders are
in italics.
Alternatives are specified like (alt1|alt2|alt3).

Command  Options                            Description                        
                                                                               
help                                                     print a command       
                                                         summary.              
                                                                               
version                                                  print version info    
                                                                               
                                                         Set the status of the 
                                                         server with the given 
                                                         index or label (where 
                                                         the given label       
                                                         matches the one given 
                                                         with the label option 
                                                         in the respective     
                                                         server section in the 
                                                         config file) to up or 
                                                         down, or force a      
                                                         retest. The index is  
         (index  (up|down|                               assigned in the order 
server   |       retest)                                 of definition in      
         label)                                          pdnsd.cache starting  
                                                         with 0. Use the status
                                                         command to view the   
                                                         indices and labels.   
                                                         You can specify all   
                                                         instead of an index or
                                                         label to perform th   
                                                         action for all servers
                                                         registered with pdnsd.
                                                         Example:              
                                                         pdnsd-ctl server 0    
                                                         retest                
                                                                               
                                                         Delete or invalidate  
                                                         the record of the     
                                                         given domain name if  
                                                         it is in the cache.   
                                                         Invalidation means    
                                                         that the record is    
                                                         marked as timed out,  
                                                         and such is reloaded  
                                                         if possible (if       
                                                         purge_cache is set to 
                                                         on, it will be deleted
                 (delete|                                in any case).         
record   name    invalidate)                             For local records     
                                                         (i.e., records that   
                                                         were given in the     
                                                         config file using a rr
                                                         section, records read 
                                                         from a hosts-style    
                                                         file and records added
                                                         using pdnsd-ctl),     
                                                         invalidation has no   
                                                         effect. Deletion will 
                                                         work, though. Example:
                                                         pdnsd-ctl record      
                                                         localhost. delete     
                                                                               
                                                         Load a hosts-style    
                                                         file. Works like using
                                                         the pdnsd source      
                                                         option. owner and ttl 
                                                         are used as in the    
                                                         source section. ttl   
                                                         has a default of 900  
                                                         (it does not need to  
                                                         be specified). The    
                                                         next to last option   
                                                         corresponds to the    
                                                         serve_aliases option, 
                                                         and is off by default 
                                                         (i.e. if it is not    
source   fn      owner        [ttl]  [(on|  [noauth]     specified). noauth is 
                                     off)]               used to make the      
                                                         domains               
                                                         non-authoritative -   
                                                         please see the        
                                                         description of the    
                                                         authrec config file   
                                                         options for a         
                                                         description of what   
                                                         that means. fn is the 
                                                         filename. The file    
                                                         must be readable by   
                                                         pdnsd! Example:       
                                                         pdnsd-ctl source /etc/
                                                         hosts localhost. 900  
                                                         off                   
                                                                               
                                                                               
                                                         Add a record of the   
                                                         given type to the     
                                                         pdnsd cache, replacing
                                                         existing records for  
add      a       addr         name   [ttl]  [noauth]     the same name and     
                                                         type. The 2nd argument
                                                         corresponds to the    
                                                         argument of the option
                                                         in the rr section that
                                                         is named like the     
                                                         first option: a is a  
                                                         record for            
                                                         hostname-to-address   
                                                         mapping, aaaa is the  
                                                         same thing for IPv6   
                                                         addresses, and ptr is 
add      aaaa    addr         name   [ttl]  [noauth]     for                   
                                                         address-to-hostname   
                                                         mapping. See the      
                                                         documentation for the 
                                                         rr section for more   
                                                         details. The ttl is   
                                                         optional, the default 
                                                         is 900 seconds. noauth
                                                         is used to make the   
                                                         domains               
                                                         non-authoritative -   
                                                         please see the        
add      ptr     host         name   [ttl]  [noauth]     description of the    
                                                         authrec config file   
                                                         options for a         
                                                         description of what   
                                                         that means. If you    
                                                         want no other record  
                                                         than the newly added  
                                                         in the cache, do      
                                                         pdnsdctl record name  
                                                         delete before adding  
                                                         records. This is also 
                                                         better when           
add      cname   host         name   [ttl]  [noauth]     overwriting local     
                                                         records. Example:     
                                                         pdnsd-ctl add a       
                                                         127.0.0.1 localhost.  
                                                         900                   
                                                                               
                                                                               
                                                         Add a negative cached 
                                                         record to pdnsd's     
                                                         cache, replacing      
neg      name    [type]       [ttl]                      existing records for  
                                                         the same name and     
                                                         type. If no type is   
                                                         given, the whole      
                                                         domain is cached      
                                                         negative. For negative
                                                         cached records, errors
                                                         are immediately       
                                                         returned on a query,  
                                                         without querying other
                                                         servers first. The ttl
                                                         is optional, the      
                                                         default is 900        
                                                         seconds.              
                                                         You can get a list of 
                                                         all types you can pass
                                                         to this command using 
                                                         pdnsd-ctl             
                                                         list-rrtypes. The type
                                                         is treated            
                                                         case-sensitive!       
                                                         Example:              
                                                         pdnsd-ctl neg foo.bar 
                                                         A 900                 
                                                         pdnsd-ctl neg foo.baz 
                                                         900                   
                                                                               



4 contrib/

The contrib directory in the pdnsd distribution contains useful
user-contributed scripts.
So far, there is a script contributed by Marko Stolle that makes pdnsd usable
in a DHCP setup. Please take a look into the README file in the contrib
directory for further information.


5 Problems...

If you have problems with configuring or tunning pdnsd, be sure to read th FAQ.
If this does not help you, pdnsd crashes or you find bugs, please mail me at 
tmoestl@gmx.net.


5 Hacking

Here comes some information you might find useful for hacking on pdnsd.

6.1 Source files

Makefile.am,     autoconf/automake/autoheader scripts. Makefile.am's are in    
configure.in,    most subdirectories.                                          
acconfig.h                                                                     
                                                                               
pdnsd.spec.in    A template from which configure generates a spec file for     
                 building rpm's for various distributions.                     
                                                                               
version          Contains only the program version string. Needed for several  
                 templates.                                                    
                                                                               
src/rc/*         rc scripts for various linux distributions.                   
                                                                               
                 The pdnsd cache subsystem(s) as defined in src/cacheing/      
                 cache.h. There is the "traditional" pdnsd system in the       
src/cacheing/*   subdirectory native. This system keeps the cache in memory and
                 uses hash tables for accesses. Sourav K. Mandal is working on 
                 a system using gdbm.                                          
                                                                               
src/pdnsd-ctl/*  Contains the code for pdnsd-ctl, a program that allows to     
                 control pdnsd at run time.                                    
                                                                               
src/             The lex/flex source file for the config file lexer. This is a 
conf-lex.l.in    template because there might be inserted "%option yylineno"   
                 for proper flex support.                                      
                                                                               
                 This is automatically generated by configure from             
src/conf-lex.l.  conf.l.templ. It may be overwritten in any make, so never     
                 modify this, but conf.l.templ instead!                        
                                                                               
src/             The yacc/bison source of the config file parser.              
conf-parse.y                                                                   
                                                                               
src/conff.c,     The configuration handler functions and their prototypes. The 
src/conff.h      parser is called from here.                                   
                                                                               
src/consts.h     Some constants used by lexer, parser, config file handler     
                 functions and in the server status thread, among others.      
                                                                               
src/dns.c, src/  Define dns message structures, constants, and some common dns 
dns.h            data handlers. dns.h contains gcc-specific code (in           
                 praticular, "__attribute__((packed))").                       
                                                                               
src/                                                                           
dns_answer.c,    Define functions that answer incoming dns queries.            
src/                                                                           
dns_answer.h                                                                   
                                                                               
src/                                                                           
dns_query.c,     Define functions to manage outgoing dns queries.              
src/dns_query.h                                                                
                                                                               
src/error.c,     Functions for error output to stderr or the syslog.           
src/error.h                                                                    
                                                                               
src/helpers.c,   Define miscellaneous helper functions.                        
src/helpers.h                                                                  
                                                                               
src/icmp.c, src  Define a function for performing a ping test. This contains   
/icmp.h          OS-specific code.                                             
                                                                               
src/main.c       Contains main(), which holds the command line parser, performs
                 initialisations and signal handling.                          
                                                                               
src/netdev.c,    Define functions for network device handling. OS-specific.    
src/netdev.h                                                                   
                                                                               
src/servers.c,   Define functions for the server status thread that performs   
src/servers.h    the periodical uptests.                                       
                                                                               
src/status.c,    Define functions for the status control thread. This is       
src/status.h     pdnsd's interface to pdnsd-ctl.                               


-------------------------------------------------------------------------------

Thomas Moestl

$Id: doc.html,v 1.42 2001/07/02 18:44:30 tmm Exp $

