NDB(8) NDB(8)
NAME
query, mkhash, mkdb, cs, csquery, dns, dnsquery, ipquery,
dnsdebug, mkhosts - network database
SYNOPSIS
ndb/query [ -f dbfile ] attr value [ rattr ]
ndb/ipquery attr value rattr...
ndb/mkhash file attr
ndb/cs [ -n ] [ -f dbfile ] [ -x netmtpt ]
ndb/csquery
ndb/dns [ -rs ] [ -f dbfile ] [ -x netmtpt ]
ndb/dnsquery
ndb/dnsdebug [ -rx ] [ [ @server ] domain-name [ type ] ]
ndb/mkdb
DESCRIPTION
The network database holds administrative information used
by network programs such as dhcpd(8), ipconfig(8), con(1),
etc.
Ndb/query searches the database for an attribute of type
attr and value value. If rattr is not specified, all entries
matched by the search are returned. If rattr is specified,
the value of the first pair with attribute rattr of all the
matched entries is returned.
Ndb/ipquery uses ndbipinfo (see ndb(2)) to search for the
values of the attributes rattr corresponding to the system
with entries of attribute type attr and value value.
Ndb/mkhash creates a hash file for all entries with
attribute attr in database file file. The hash files are
used by ndb/query and by the ndb library routines.
Ndb/cs is a server used by dial(2) to translate network
names. It is started at boot time. It finds out what net-
works are configured by looking for /net/*/clone when it
starts. It can also be told about networks by writing to
/net/cs a message of the form:
add net1 net2 ...
Ndb/cs also sets the system name in /dev/sysname if it can
figure it out. The options are:
-f supplies the name of the data base file to use, default
/lib/ndb/local.
-x specifies the mount point of the network.
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-n causes cs to do nothing but set the system name.
Ndb/csquery can be used to query ndb/cs to see how it
resolves addresses. Ndb/csquery prompts for addresses and
prints out what ndb/cs returns.
Ndb/dns is a server used by ndb/cs and by remote systems to
translate Internet domain names. Ndb/dns is started at boot
time. By default dns serves only requests written to
/net/dns. The options are:
-f supplies the name of the data base file to use, default
/lib/ndb/local.
-x specifies the mount point of the network.
-s also answer domain requests sent to UDP port 53.
-r defer to other servers to resolve queries.
When the -r option is specified, the servers used come from
the dns attribute in the database. For example, to specify
a set of dns servers that systems on the network mh-net:
ipnet=mh-net ip=135.104.0.0 ipmask=255.255.0.0
dns=ns1.cs.bell-labs.com
dns=ns2.cs.bell-labs.com
dom=ns1.cs.bell-labs.com ip=135.104.1.11
dom=ns2.cs.bell-labs.com ip=135.104.1.12
The server for a domain is indicated by a database entry
containing both a dom and a ns attribute. For example, the
entry for the Internet root is:
dom=
ns=A.ROOT-SERVERS.NET
ns=B.ROOT-SERVERS.NET
ns=C.ROOT-SERVERS.NET
dom=A.ROOT-SERVERS.NET ip=198.41.0.4
dom=B.ROOT-SERVERS.NET ip=128.9.0.107
dom=C.ROOT-SERVERS.NET ip=192.33.4.12
The last three lines provide a mapping for the server names
to their ip addresses. This is only a hint and will be
superceded from whatever is learned from servers owning the
domain.
The root of a domain subtree served by the local database is
indicated by an entry with an soa attribute. For example,
the Bell Labs CS research domain is:
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NDB(8) NDB(8)
dom=cs.bell-labs.com soa=
refresh=3600 ttl=3600
ns=plan9.bell-labs.com
ns=ns1.cs.bell-labs.com
ns=ns2.cs.bell-labs.com
mb=presotto@plan9.bell-labs.com
mx=mail.research.bell-labs.com pref=20
mx=plan9.bell-labs.com pref=10
Here, the mb entry is the mail address of the person respon-
sible for the domain (default postmaster). The mx entries
list mail exchangers for the domain name and refresh and ttl
define the area refresh interval and the minimum TTL for
records in this domain.
Delegation of a further subtree to another set of name-
servers is indicated by an soa=delegated attribute.
dom=bignose.cs.research.bell-labs.com
soa=delegated
ns=anna.cs.research.bell-labs.com
ns=dj.cs.research.bell-labs.com
Nameservers within the delegated domain (as in this example)
must have their IP addresses listed elsewhere in ndb files.
Wild-carded domain names can also be used. For example, to
specify a mail forwarder for all Bell Labs research systems:
dom=*.research.bell-labs.com
mx=research.bell-labs.com
`Cname' aliases may be established by adding a cname
attribute giving the real domain name; the name attached to
the dom attribute is the alias. `Cname' aliases are
severely restricted; the aliases may have no other
attributes than dom and are daily further restricted in
their use by new RFCs.
cname=anna.cs.research.bell-labs.com dom=www.cs.research.bell-labs.com
Ndb/dnsquery can be used to query ndb/dns to see how it
resolves requests. Ndb/dnsquery prompts for commands of the
form
domain-name request-type
where request-type can be ip, mx, ns, cname, ptr.... In the
case of the inverse query type, ptr, dnsquery will reverse
the ip address and tack on the .in-addr.arpa for you.
Ndb/dnsdebug is like ndb/dnsquery but bypasses the local
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server. It communicates via UDP with the domain name
servers in the same way that the local resolver would and
displays all packets received. The query can be specified
on the command line or can be prompted for. The queries
look like those of ndb/dnsquery with one addition.
Ndb/dnsdebug can be directed to query a particular name
server by the command @name-server. From that point on, all
queries go to that name server rather than being resolved by
dnsdebug. The @ command returns query resolution to
dnsdebug. Finally, any command preceded by a @name-server
sets the nameserver only for that command.
Normally dnsdebug uses the /net interface and the database
file /lib/ndb/local. The -x option directs dnsdebug to use
the /net.alt interface and /lib/ndb/external file. The -r
option is the same as for ndb/dns.
Ndb/mkdb is used in concert with awk(1) scripts to convert
uucp systems files and IP host files into database files.
It is very specific to the situation at Murray Hill.
When the database files change underfoot, ndb/cs and ndb/dns
track them properly. Nonetheless, to keep the database
searches efficient it is necessary to run ndb/mkhash when-
ever the files are modified. It may be profitable to con-
trol this by a frequent cron(8) job.
Ndb/mkhosts generates a BSD style hosts, hosts.txt, and
hosts.equiv files from an ndb data base file specified on
the command line (default /lib/ndb/local). For local rea-
sons the files are called hosts.1127, astro.txt, and
hosts.equiv.
EXAMPLES
% ndb/query sys helix
sys=helix dom=helix.research.bell-labs.com bootf=/mips/9powerboot
ip=135.104.117.31 ether=080069020427
proto=il
% ndb/dnsquery
> plan9.bell-labs.com ip
plan9.bell-labs.com ip 204.178.31.2
> 204.178.31.2 ptr
2.31.178.204.in-addr.arpa ptr plan9.bell-labs.com
2.31.178.204.in-addr.arpa ptr ampl.com
>
FILES
/lib/ndb/local first database file searched
/lib/ndb/local.* hash files for /lib/ndb/local
/srv/cs service file for ndb/cs
/net/cs where /srv/cs gets mounted
/srv/dns service file for ndb/dns
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/net/dns where /srv/dns gets mounted
SOURCE
/sys/src/cmd/ndb
SEE ALSO
ndb(2) ndb(6)
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