lwdnsqMichaelRichardsonmcr@sandelman.ottawa.on.ca2003Michael RichardsonReferenceipsec lwdnsq8lwdnsqlookup items in DNS to help pluto (and others)ipsec lwdnsqipsec lwdnsqDescription
The
ipsec lwdnsq
is a helper program that does DNS lookups for other programs. It implements
an asynchronous interface on stdin/stdout, with an ASCII driven command
language.
If stdin is a tty or if the
option is given, then it issues a prompt to the user. Otherwise, it is
silent, except for results.
The program will accept multiple queries concurrently, with each result
being marked with the ID provided on the output. The IDs are strings.
If the
option is given, then the program will not attempt to execute concurrent
queries, but will serialize all input and output.
QUERY LANGUAGE
There are eleven command that the program understands. This is to lookup
different types of records in both the forward and reverse maps. Every query
includes a queryid, which is returned in the output, on every single line to
identify the transaction.
KEY
This request looks up the KEY resource record for the given .
KEY4
This request looks up the KEY resource record found in the reverse map for
the IP version 4 address , i.e. it looks
up D.C.B.A.in-addr.arpa.
KEY6
This request looks up the KEY resource record found in the reverse map
for the IPv6 address , i.e.
it looks the 32-nibble long entry in ip6.arpa (and ip6.int).
TXT4
This request looks up the TXT resource record found in the reverse map for
the IP version 4 address , i.e. it looks
up D.C.B.A.in-addr.arpa.
TXT6
This request looks up the TXT resource record found in the reverse map
for the IPv6 address , i.e.
it looks the 32-nibble long entry in ip6.arpa (and ip6.int).
KEY
This request looks up the IPSECKEY resource record for the given
. See note about IPSECKEY processing, below.
IPSECKEY4
This request looks up the IPSECKEY resource record found in the reverse map for
the IP version 4 address , i.e. it looks
up D.C.B.A.in-addr.arpa. See special note about IPSECKEY processing, below.
IPSECKEY6
This request looks up the IPSECKEY resource record found in the reverse map
for the IPv6 address , i.e.
it looks the 32-nibble long entry in ip6.arpa (and ip6.int). See
special note about IPSECKEY processing, below.
OE4
This request looks an appropriate record for Opportunistic
Encryption for the given IP address. This attempts to look for the
delegation record. This may be one of IPSECKEY, KEY, or TXT
record. Unless configured otherwise, (see OE4 Directives, below), then
a query type of ANY will be used to retrieve all relevant records, and
all will be returned.
OE6
This request looks an appropriate record for Opportunistic
Encryption for the given IPv6 address. This attempts to look for the
delegation record. This may be one of IPSECKEY, KEY, or TXT
record. Unless configured otherwise, (see OE Directives, below), then
a query type of ALL will be used to retrieve all relevant records, and
all will be returned.
i.e. it looks the 32-nibble long entry in ip6.arpa (and ip6.int).
A
This request looks up the A (IPv4) resource record for the given
.
AAAA
This request looks up the AAAA (IPv6) resource record for the given
.
Replies to queries
All replies from the queries are in the following format:
<ID> <TIME> <TTL> <TYPE> <TYPE-SPECIFIC> \n
ID
this is the value that was provided in
the query. It is repeated on every line to permit the replies to be
properly associated with the query. When the response is not ascribable to
particular query (such as for a mis-formed query), then the query ID "0" will
be used.
TIME
this is the current time in seconds since epoch.
TTL
for answers which have a time to live, this is the current value. The
answer is valid for this number of seconds. If there is no useful
value here, then the number 0 is used.
TYPE
This is the type of the record that is being returned. The types are
described in the next section. The TYPE specific data that follows is
specific to the type.
The replies are limited to 4096 bytes, a value defined as
LWDNSQ_RESULT_LEN_MAX. This is defined in
freeswan.h.
All of the replies which include resource records use the
standard presentation format (with no line feeds or carriage returns)
in their answer.START
This reply indicates that a query has been received and has been
started. It serves as an anchor point for timing, as well as an acknowledgement.
DONE
This reply indicates that a query is entirely over, and no further
information from this query will be sent.
RETRY
This reply indicates that a query is entirely over, but that no
data was found. The records may exist, but appropriate servers could
not be reached.
FATAL
This reply indicates that a query is entirely over, and that no
data of the type requested could be found. There were no timeouts, and
all servers were available and confirmed non-existances. There may be
NXT records returned prior to this.
CNAME
This is an interim reply, and indicates that a CNAME was found (and
followed) while performing the query. The value of the CNAME is
present in the type specific section.
CNAMEFROM
This is an interim reply, and indicates that a CNAME was found. The
original name that was queries for was not the canonical name, and
this reply indicates the name that was actually followed.
NAME
This is an interim reply. The original name that was queries for was
not the canonical name. This reply indicates the canonical name.
DNSSEC
This is an interim reply. It is followed either by "OKAY" or "not
present.
It indicates if DNSSEC was available on the reply.
TXT and AD-TXT
This is an interim reply. If there are TXT resource records in the
reply, then each one is presented using this type. If preceeded by
AD-, then this record was signed with DNSSEC.
A and AD-A
This is an interim reply. If there are A resource records in the
reply, then each one is presented using this type. If preceeded by
AD-, then this record was signed with DNSSEC.
AAAA and AD-AAAA
This is an interim reply. If there are AAAA resource records in the
reply, then each one is presented using this type. If preceeded by
AD-, then this record was signed with DNSSEC.
PTR and AD-PTR
This is an interim reply. If there are PTR resource records in the
reply, then each one is presented using this type. If preceeded by
AD-, then this record was signed with DNSSEC.
KEY and AD-KEY
This is an interim reply. If there are KEY resource records in the
reply, then each one is presented using this type. If preceeded by
AD-, then this record was signed with DNSSEC.
IPSECKEY and AD-IPSECKEY
This is an interim reply. If there are IPSEC resource records in the
reply, then each one is presented using this type. If preceeded by
AD-, then this record was signed with DNSSEC.
Special IPSECKEY processing
At the time of this writing, the IPSECKEY resource record is not
entirely specified. In particular no resource record number has been
assigned. This program assumes that it is resource record number
45. If the file
@IPSEC_CONFDDIR@/lwdnsq.conf
exists, and contains a line like
ipseckey_rr=
then this number will be used instead. The file is read only once at
startup.
OE Directives
If the file
@IPSEC_CONFDDIR@/lwdnsq.conf
exists, and contains a line like
queryany=false
then instead of doing an ALL query when looking for OE delegation
records, lwdnsq will do a series of queries. It will first look for
IPSECKEY, and then TXT record. If it finds neither, it will then look
for KEY records of all kinds, although they do not contain delegation
information.
Special IPSECKEY processing
/etc/ipsec.d/lwdnsq.conf