NDB(8)

NAME

query, mkhash, mkdb, cs, csquery, dns, dnsquery − network database

SYNOPSIS

ndb/query attr value [ rattr ]
ndb/mkhash file attr
ndb/cs [ -n ] [ -f dbfile ]
ndb/csquery
ndb/dns [ -s ] [ -f dbfile ]
ndb/dnsquery
ndb/mkdb

DESCRIPTION

The network database holds administrative information used by network programs such as bootp(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/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. Option -f supplies the name of the data base file to use, default /lib/ndb/local. It is started at boot time. It finds out what networks 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. Option -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. Option -s causes the server to also answer domain requests sent to UDP port 53. Name resolution is performed by searching the local database and by querying remote servers. 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=ns.nic.ddn.mil
ns=kava.nisc.sri.com
ns=aos.brl.mil

The root of a domain subtree served by the local database is indicated by an entry with an soa attribute. For example, the AT&T research domain is:

dom=research.att.com soa
mb=ches.research.att.com
ns=inet.research.att.com
ns=research.research.att.com

Here, the mb entry is the mail address of the person responsible for the domain (default postmaster). Wild-carded domain names can also be used. For example, to specify a mail forwarder for all AT&T research systems:

dom=∗.research.att.com
mx=research.att.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/mkdb is used in concert with awk(1) scripts to convert uucp systems files, IP host files, and Datakit configuration 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 whenever the files are modified. It may be profitable to control this by a frequent cron(8) job.

EXAMPLES

% ndb/query sys helix
sys=helix dom=helix.research.att.com bootf=/mips/9powerboot
ip=135.104.117.31 ether=080069020427
dk=nj/astro/helix
proto=il
% ndb/query sys helix ip
135.104.117.31
% ndb/dnsquery
> 9net.research.att.com ip
9net.research.att.com ip192.20.225.252
> 192.20.225.252 ptr
252.225.20.192.in-addr.arpa ptr9net.research.att.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

/net/dns where /srv/dns gets mounted

SOURCE

/sys/src/cmd/ndb

Museum

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