From: Marek Vavruša <marek@vavrusa.com>
Date: Thu, 15 Mar 2018 23:13:47 +0000 (-0700)
Subject: kres: added interface for RR set wire size and packet remaining bytes
X-Git-Tag: v2.4.0~54^2~2
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=47275ddf2dc72c8c15036084bcf8a4cebe7e1345;p=thirdparty%2Fknot-resolver.git

kres: added interface for RR set wire size and packet remaining bytes
---

diff --git a/daemon/lua/kres-gen.lua b/daemon/lua/kres-gen.lua
index 7a8e59732..911e2e090 100644
--- a/daemon/lua/kres-gen.lua
+++ b/daemon/lua/kres-gen.lua
@@ -252,6 +252,7 @@ void knot_rrset_init_empty(knot_rrset_t *);
 uint32_t knot_rrset_ttl(const knot_rrset_t *);
 int knot_rrset_txt_dump(const knot_rrset_t *, char **, size_t *, const knot_dump_style_t *);
 int knot_rrset_txt_dump_data(const knot_rrset_t *, const size_t, char *, const size_t, const knot_dump_style_t *);
+size_t knot_rrset_size(const knot_rrset_t *);
 uint16_t knot_rrsig_type_covered(const knot_rdataset_t *, size_t);
 uint32_t knot_rrsig_sig_expiration(const knot_rdataset_t *, size_t);
 uint32_t knot_rrsig_sig_inception(const knot_rdataset_t *, size_t);
@@ -260,6 +261,7 @@ uint16_t knot_pkt_qtype(const knot_pkt_t *);
 uint16_t knot_pkt_qclass(const knot_pkt_t *);
 int knot_pkt_begin(knot_pkt_t *, knot_section_t);
 int knot_pkt_put_question(knot_pkt_t *, const knot_dname_t *, uint16_t, uint16_t);
+int knot_pkt_put(knot_pkt_t *, uint16_t, const knot_rrset_t *, uint16_t);
 const knot_rrset_t *knot_pkt_rr(const knot_pktsection_t *, uint16_t);
 const knot_pktsection_t *knot_pkt_section(const knot_pkt_t *, knot_section_t);
 knot_pkt_t *knot_pkt_new(void *, uint16_t, knot_mm_t *);
diff --git a/daemon/lua/kres-gen.sh b/daemon/lua/kres-gen.sh
index 9c7b55818..fa2f11461 100755
--- a/daemon/lua/kres-gen.sh
+++ b/daemon/lua/kres-gen.sh
@@ -111,6 +111,7 @@ printf "\tchar _stub[];\n};\n"
 	knot_rrset_ttl
 	knot_rrset_txt_dump
 	knot_rrset_txt_dump_data
+	knot_rrset_size
 	knot_rrsig_type_covered
 	knot_rrsig_sig_expiration
 	knot_rrsig_sig_inception
@@ -120,6 +121,7 @@ printf "\tchar _stub[];\n};\n"
 	knot_pkt_qclass
 	knot_pkt_begin
 	knot_pkt_put_question
+	knot_pkt_put
 	knot_pkt_rr
 	knot_pkt_section
 	knot_pkt_new
diff --git a/daemon/lua/kres.lua b/daemon/lua/kres.lua
index b75f5c79a..61cac2267 100644
--- a/daemon/lua/kres.lua
+++ b/daemon/lua/kres.lua
@@ -379,6 +379,11 @@ ffi.metatype( knot_rrset_t, {
 			assert(rrsig.type == const_type.RRSIG)
 			return (rr.type == rrsig:type_covered() and rr:owner() == rrsig:owner())
 		end,
+		-- Return RR set wire size
+		wire_size = function(rr)
+			assert(ffi.istype(knot_rrset_t, rr))
+			return tonumber(knot.knot_rrset_size(rr))
+		end,
 	},
 })
 
@@ -560,6 +565,15 @@ ffi.metatype( knot_pkt_t, {
 			if ret ~= 0 then return nil, knot_error_t(ret) end
 			return true
 		end,
+		-- Put an RR set in the packet
+		-- Note: the packet doesn't take ownership of the RR set
+		put_rr = function (pkt, rr)
+			assert(ffi.istype(knot_pkt_t, pkt))
+			assert(ffi.istype(knot_rrset_t, rr))
+			local ret = C.knot_pkt_put(pkt, 0, rr, 0)
+			if ret ~= 0 then return nil, knot_error_t(ret) end
+			return true
+		end,
 		recycle = function (pkt)
 			assert(ffi.istype(knot_pkt_t, pkt))
 			local ret = C.kr_pkt_recycle(pkt)
@@ -588,6 +602,14 @@ ffi.metatype( knot_pkt_t, {
 			assert(ffi.istype(knot_pkt_t, pkt))
 			return packet_tostring(pkt)
 		end,
+		-- Return number of remaining empty bytes in the packet
+		-- This is generally useful to check if there's enough space
+		remaining_bytes = function (pkt)
+			assert(ffi.istype(knot_pkt_t, pkt))
+			local occupied = pkt.size + pkt.reserved
+			assert(pkt.max_size >= occupied)
+			return tonumber(pkt.max_size - occupied)
+		end,
 		-- Packet manipulation
 		parse = function (pkt)
 			assert(ffi.istype(knot_pkt_t, pkt))
diff --git a/tests/config/basic.test.lua b/tests/config/basic.test.lua
index 55f133393..95c24bc56 100644
--- a/tests/config/basic.test.lua
+++ b/tests/config/basic.test.lua
@@ -45,7 +45,9 @@ local function test_rrset_functions()
 	same(rr:class(kres.class.IN), kres.class.IN, 'can restore a class')
 	same(rr.type, kres.type.A, 'created RR has correct type')
 	-- test adding rdata
+	same(rr:wire_size(), 0, 'empty RR wire size is zero')
 	ok(rr:add_rdata('\1\2\3\4', 4, 66), 'adding RDATA works')
+	same(rr:wire_size(), 5 + 4 + 4 + 2 + 4, 'RR wire size works after adding RDATA')
 	-- test conversion to text
 	local expect = 'com.                	66	A	1.2.3.4\n'
 	same(rr:txt_dump(), expect, 'RR to text works')
@@ -104,7 +106,9 @@ local function test_packet_functions()
 	boom(pkt.begin, {pkt, 10}, 'switching to invalid section doesnt work')
 	ok(pkt:begin(kres.section.ADDITIONAL), 'switching to different section works')
 	boom(pkt.begin, {pkt, 0}, 'rewinding sections doesnt work')
+	local before_insert = pkt:remaining_bytes()
 	ok(pkt:put(pkt:qname(), 900, pkt:qclass(), kres.type.A, '\4\3\2\1'), 'adding rrsets to different section works')
+	same(pkt:remaining_bytes(), before_insert - (2 + 4 + 4 + 2 + 4), 'remaining bytes count goes down with insertions')
 	-- Test conversions to text
 	like(pkt:tostring(), '->>HEADER<<-', 'packet to text works')
 	-- Test deserialization
@@ -126,6 +130,15 @@ local function test_packet_functions()
 	same(parsed:arcount(), pkt:arcount(), 'parsed packet has same additional count')
 	same(parsed:tostring(), pkt:tostring(), 'parsed packet is equal to source packet')
 
+	-- Test adding RR sets directly
+	local copy = kres.packet(512)
+	copy:question(todname('hello'), kres.class.IN, kres.type.A)
+	copy:begin(kres.section.ANSWER)
+	local rr = kres.rrset(pkt:qname(), kres.type.A)
+	rr:add_rdata('\4\3\2\1', 4, 66)
+	ok(copy:put_rr(rr), 'adding RR sets directly works')
+	ok(copy:recycle())
+
 	-- Test recycling of packets
 	-- Clear_payload keeps header + question intact
 	local cleared = kres.packet(#wire, wire) -- same as "parsed" above