History

John Belamaric ef315ef3e2 Rewrite edns0 (#561 ) * Add edns0 code rewrite * check arg count * change `new`; set EDNS0 if request doesn't have it set * change set to replace_or_append * change to append_or_replace * return error in new * update documents * fixt UT * return error * go fmt * Rework for more general EDNS0 use Also changed how rules are created and validated. Implements EDNS0 NSID in addition to local. * go fmt * README updates, NSID tests and fixes * gofmt -s -w * Fix tests for rewrite syntax change * Add tests, fix error message * Review nits * Missed on nit * More tests, integration test, fix edns0 parse issue * Fix README, use RewriteIgnored * go fmt		2017-03-06 21:32:17 +00:00
..
testdata	First commit	2016-03-18 20:57:35 +00:00
class.go	Rewrite edns0 (#561 )	2017-03-06 21:32:17 +00:00
condition.go	Fix import path `github.com/miekg/coredns` -> `github.com/coredns/coredns` (#547 )	2017-02-22 06:51:47 +00:00
condition_test.go	Use context.Context	2016-03-19 07:32:50 +00:00
edns0.go	Rewrite edns0 (#561 )	2017-03-06 21:32:17 +00:00
name.go	Rewrite edns0 (#561 )	2017-03-06 21:32:17 +00:00
README.md	Rewrite edns0 (#561 )	2017-03-06 21:32:17 +00:00
reverter.go	Golint2 (#280 )	2016-09-23 09:14:12 +01:00
rewrite.go	Rewrite edns0 (#561 )	2017-03-06 21:32:17 +00:00
rewrite_test.go	Rewrite edns0 (#561 )	2017-03-06 21:32:17 +00:00
setup.go	Rewrite edns0 (#561 )	2017-03-06 21:32:17 +00:00
setup_test.go	Rewrite edns0 (#561 )	2017-03-06 21:32:17 +00:00
type.go	Rewrite edns0 (#561 )	2017-03-06 21:32:17 +00:00

README.md

rewrite

rewrite performs internal message rewriting. Rewrites are invisible to the client. There are simple rewrites (fast) and complex rewrites (slower), but they're powerful enough to accommodate most dynamic back-end applications.

Syntax

rewrite FIELD FROM TO

FIELD is (type, class, name, ...)
FROM is the exact name of type to match
TO is the destination name or type to rewrite to

When the FIELD is type and FROM is (A, MX, etc.), the type of the message will be rewritten; e.g., to rewrite ANY queries to HINFO, use rewrite type ANY HINFO.

When the FIELD is class and FROM is (IN, CH, or HS) the class of the message will be rewritten; e.g., to rewrite CH queries to IN use rewrite class CH IN.

When the FIELD is name the query name in the message is rewritten; this needs to be a full match of the name, e.g., rewrite name miek.nl example.org.

When the FIELD is edns0 an EDNS0 option can be appended to the request as described below.

If you specify multiple rules and an incoming query matches on multiple (simple) rules, only the first rewrite is applied.

EDNS0 Options

Using FIELD edns0, you can set, append, or replace specific EDNS0 options on the request.

replace will modify any matching (what that means may vary based on EDNS0 type) option with the specified option
append will add the option regardless of what options already exist
set will modify a matching option or add one if none is found

Currently supported are EDNS0_LOCAL and EDNS0_NSID.

`EDNS0_LOCAL`

This has two fields, code and data. A match is defined as having the same code. Data may be a string, or if it starts with 0x it will be treated as hex. Example:

rewrite edns0 local set 0xffee 0x61626364

rewrites the first local option with code 0xffee, setting the data to "abcd". Equivalent:

rewrite edns0 local set 0xffee abcd

`EDNS0_NSID`

This has no fields; it will add an NSID option with an empty string for the NSID. If the option already exists and the action is replace or set, then the NSID in the option will be set to the empty string.