From: Remi Gacogne <remi.gacogne@powerdns.com>
Date: Fri, 9 Jul 2021 07:51:28 +0000 (+0200)
Subject: dnsdist: Document what is available from per-thread Lua FFI contexts
X-Git-Tag: dnsdist-1.7.0-alpha1~88^2
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=refs%2Fpull%2F10501%2Fhead;p=thirdparty%2Fpdns.git

dnsdist: Document what is available from per-thread Lua FFI contexts
---

diff --git a/pdns/dnsdistdist/docs/rules-actions.rst b/pdns/dnsdistdist/docs/rules-actions.rst
index 61e456b497..38408e8317 100644
--- a/pdns/dnsdistdist/docs/rules-actions.rst
+++ b/pdns/dnsdistdist/docs/rules-actions.rst
@@ -506,7 +506,9 @@ These ``DNSRule``\ s be one of the following items:
 
   The ``function`` should return true if the query matches, or false otherwise. If the Lua code fails, false is returned.
 
-  The function will be invoked in a per-thread Lua state, without access to the global Lua state.
+  The function will be invoked in a per-thread Lua state, without access to the global Lua state. All constants (:ref:`DNSQType`, :ref:`DNSRCode`, ...) are available in that per-thread context,
+  as well as all FFI functions. Objects and their bindings that are not usable in a FFI context (:class:`DNSQuestion`, :class:`DNSDistProtoBufMessage`, :class:`PacketCache`, ...)
+  are not available.
 
   :param string function: a Lua string returning a Lua function
 
@@ -1018,7 +1020,9 @@ The following actions exist.
 
   The ``function`` should return a :ref:`DNSAction`. If the Lua code fails, ServFail is returned.
 
-  The function will be invoked in a per-thread Lua state, without access to the global Lua state.
+  The function will be invoked in a per-thread Lua state, without access to the global Lua state. All constants (:ref:`DNSQType`, :ref:`DNSRCode`, ...) are available in that per-thread context,
+  as well as all FFI functions. Objects and their bindings that are not usable in a FFI context (:class:`DNSQuestion`, :class:`DNSDistProtoBufMessage`, :class:`PacketCache`, ...)
+  are not available.
 
   :param string function: a Lua string returning a Lua function
 
@@ -1030,7 +1034,9 @@ The following actions exist.
 
   The ``function`` should return a :ref:`DNSResponseAction`. If the Lua code fails, ServFail is returned.
 
-  The function will be invoked in a per-thread Lua state, without access to the global Lua state.
+  The function will be invoked in a per-thread Lua state, without access to the global Lua state. All constants (:ref:`DNSQType`, :ref:`DNSRCode`, ...) are available in that per-thread context,
+  as well as all FFI functions. Objects and their bindings that are not usable in a FFI context (:class:`DNSQuestion`, :class:`DNSDistProtoBufMessage`, :class:`PacketCache`, ...)
+  are not available.
 
   :param string function: a Lua string returning a Lua function