D. J. Bernstein
Internet publication

The rbldns-data program

rbldns-data reads an IP address list from a file named data in the current directory. It creates data.cdb in a binary format designed for fast access by rbldns. It may also create some other files with names beginning with data.

rbldns-data updates data.cdb atomically, so you can use it safely while rbldns is running. If anything goes wrong with the creation of data.cdb, rbldns-data stops and leaves the old data.cdb in place.

Data format

The IP address ip is on the list.

All IP addresses that share the first n bits of the IP address ip are on the list. For example, means all 1.2.3.* addresses. n must be at least 8, and all bits past the nth in ip must be 0.

DNS queries for addresses on the list will receive an A record of a and a TXT record of txt. Typically a is and txt is a pointer to a web page about the list.

If txt ends with $, rbldns replaces the $ with the IP address.

Comment line. The line is ignored.