This program is a debugging aid. It is not efficient, especially with a long config file, but it can give any reply to any query. This can help the developer pre-script replies for queries.
It listens to IP4 UDP and TCP by default. You can specify a packet RR by RR with header flags to return.
ldns-testns is not meant for production use.
You can use $ORIGIN and $TTL directives. Zone file '(' and ')' to span multiple lines are not allowed.
$ORIGIN origin $TTL default_ttl
; first give MATCH lines, that say what queries are matched ; by this entry. ; 'opcode' makes the query match the opcode from the reply ; if you leave it out, any opcode matches this entry. ; 'qtype' makes the query match the qtype from the reply ; 'qname' makes the query match the qname from the reply ; 'serial=1023' makes the query match if ixfr serial is 1023.
MATCH [opcode] [qtype] [qname] [serial=<value>] MATCH [UDP|TCP] MATCH ...
; Then the REPLY header is specified.
REPLY opcode, rcode or flags.
(opcode) QUERY IQUERY STATUS NOTIFY UPDATE
(rcode) NOERROR FORMERR SERVFAIL NXDOMAIN NOTIMPL YXDOMAIN
YXRRSET NXRRSET NOTAUTH NOTZONE
(flags) QR AA TC RD CD RA AD
; any additional actions to do.
ADJUST copy_id ; 'copy_id' copies the ID from the query to the answer.
; 'sleep=10' sleeps for 10 seconds before giving the answer (TCP is open)
ADJUST [sleep=<num>] ; sleep before giving any reply ADJUST [packet_sleep=<num>] ; sleep before this packet in sequence
SECTION QUESTION <RRs, one per line> ; the RRcount is determined automatically.
SECTION ANSWER <RRs, one per line>
SECTION AUTHORITY <RRs, one per line>
SECTION ADDITIONAL <RRs, one per line>
EXTRA_PACKET ; follow with SECTION, REPLY for more packets.
HEX_ANSWER_BEGIN ; follow with hex data
; this replaces any answer packet constructed
; with the SECTION keywords (only SECTION QUERY
; is used to match queries). If the data cannot
; be parsed, ADJUST rules for the answer packet
; are ignored