From: Vladimír Čunát <vladimir.cunat@nic.cz>
Date: Fri, 7 Jul 2017 12:59:13 +0000 (+0200)
Subject: lua nitpicks: memory management
X-Git-Tag: v1.3.2~12^2~2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=41b2544ac31f82a51738efad60ff2e606df55d3c;p=thirdparty%2Fknot-resolver.git

lua nitpicks: memory management
---

diff --git a/daemon/lua/kres.lua.in b/daemon/lua/kres.lua.in
index f302a08a3..994c3796d 100644
--- a/daemon/lua/kres.lua.in
+++ b/daemon/lua/kres.lua.in
@@ -135,6 +135,8 @@ local rrset_buflen = (64 + 1) * 1024
 local rrset_buf = ffi.new('char[?]', rrset_buflen)
 local knot_rrset_t = ffi.typeof('knot_rrset_t')
 ffi.metatype( knot_rrset_t, {
+	-- beware: `owner` and `rdata` are typed as a plain lua strings
+	--         and not the real types they represent.
 	__index = {
 		owner = function(rr) return ffi.string(rr._owner, knot.knot_dname_size(rr._owner)) end,
 		ttl = function(rr) return tonumber(knot.knot_rrset_ttl(rr)) end,
@@ -317,7 +319,7 @@ local function rr2str(rr, style)
 	-- Construct a single-RR temporary set while minimizing copying.
 	local rrs = knot_rrset_t()
 	knot.knot_rrset_init_empty(rrs)
-	rrs._owner = ffi.cast('char *', rr.owner) -- explicit cast needed here
+	rrs._owner = ffi.cast('knot_dname_t *', rr.owner) -- explicit cast needed here
 	rrs.type = rr.type
 	rrs.rclass = kres.class.IN
 	knot.knot_rrset_add_rdata(rrs, rr.rdata, #rr.rdata, rr.ttl, nil)
diff --git a/modules/dns64/dns64.lua b/modules/dns64/dns64.lua
index 206daa053..e9c830b26 100644
--- a/modules/dns64/dns64.lua
+++ b/modules/dns64/dns64.lua
@@ -30,7 +30,7 @@ mod.layer = {
 				if orig.type == kres.type.A then
 					local rrs = ffi.typeof('knot_rrset_t')()
 					ffi.C.knot_rrset_init_empty(rrs)
-					rrs._owner = ffi.cast('char *', orig:owner()) -- explicit cast needed here
+					rrs._owner = ffi.cast('knot_dname_t *', orig:owner()) -- explicit cast needed here
 					rrs.type = kres.type.AAAA
 					rrs.rclass = orig.rclass
 					for k = 1, orig.rrs.rr_count do
@@ -39,6 +39,8 @@ mod.layer = {
 						ffi.copy(addr_buf + 12, rdata, 4)
 						ffi.C.knot_rrset_add_rdata(rrs, ffi.string(addr_buf, 16), 16, orig:ttl(), req.pool)
 					end
+					-- All referred memory is copied within the function,
+					-- so it doesn't matter that lua GCs our variables.
 					ffi.C.kr_ranked_rrarray_add(
 						req.answ_selected,
 						rrs,