From 2fe2edf4ffd79fc722dc313c0ba13b078e2c75fd Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Lo=C3=AFc=20Hoguin?= <essen@ninenines.eu>
Date: Mon, 26 May 2025 14:48:13 +0200
Subject: [PATCH] Fix signal int sizes

---
 src/cowboy_http3.erl                 | 16 ++--------------
 test/draft_h3_webtransport_SUITE.erl | 14 ++++++--------
 2 files changed, 8 insertions(+), 22 deletions(-)

diff --git a/src/cowboy_http3.erl b/src/cowboy_http3.erl
index bc87ceb6..8a01c795 100644
--- a/src/cowboy_http3.erl
+++ b/src/cowboy_http3.erl
@@ -556,8 +556,8 @@ early_error(State0=#state{ref=Ref, opts=Opts, peer=Peer},
 %% Datagrams.
 
 parse_datagram(State, Data) ->
-	case parse_var_int(Data) of
-		{ok, QuarterID, Rest} ->
+	case cow_http3:parse_int(Data) of
+		{QuarterID, Rest} ->
 			SessionID = QuarterID * 4,
 			case stream_get(State, SessionID) of
 				#stream{status=webtransport_session} ->
@@ -571,18 +571,6 @@ parse_datagram(State, Data) ->
 			loop(State)
 	end.
 
-%% @todo Move to Cowlib and use in cow_http3.
-parse_var_int(<<0:2, Int:6, Rest/bits>>) ->
-	{ok, Int, Rest};
-parse_var_int(<<1:2, Int:14, Rest/bits>>) ->
-	{ok, Int, Rest};
-parse_var_int(<<2:2, Int:30, Rest/bits>>) ->
-	{ok, Int, Rest};
-parse_var_int(<<3:2, Int:62, Rest/bits>>) ->
-	{ok, Int, Rest};
-parse_var_int(_) ->
-	more.
-
 %% Erlang messages.
 
 down(State0=#state{opts=Opts, children=Children0}, Pid, Msg) ->
diff --git a/test/draft_h3_webtransport_SUITE.erl b/test/draft_h3_webtransport_SUITE.erl
index 2832774a..4cde6170 100644
--- a/test/draft_h3_webtransport_SUITE.erl
+++ b/test/draft_h3_webtransport_SUITE.erl
@@ -115,7 +115,7 @@ accept_session_when_enabled(Config) ->
 	} = do_webtransport_connect(Config),
 	%% Create a bidi stream, send Hello, get Hello back.
 	{ok, BidiStreamRef} = quicer:start_stream(Conn, #{}),
-	{ok, _} = quicer:send(BidiStreamRef, <<16#41, 0:2, SessionID:6, "Hello">>),
+	{ok, _} = quicer:send(BidiStreamRef, <<1:2, 16#41:14, 0:2, SessionID:6, "Hello">>),
 	{ok, <<"Hello">>} = rfc9114_SUITE:do_receive_data(BidiStreamRef),
 	ok.
 
@@ -125,8 +125,6 @@ accept_session_when_enabled(Config) ->
 
 %% 3.4. Application Protocol Negotiation
 
-%% The user agent MAY include a WT-Available-Protocols header field in the CONNECT request. The WT-Available-Protocols enumerates the possible protocols in preference order. If the server receives such a header, it MAY include a WT-Protocol field in a successful (2xx) response. If it does, the server SHALL include a single choice from the client's list in that field. Servers MAY reject the request if the client did not include a suitable protocol. (3.4)
-
 application_protocol_negotiation(Config) ->
 	doc("Applications can negotiate a protocol to use via WebTransport. "
 		"(draft_webtrans_http3 3.4)"),
@@ -162,11 +160,11 @@ unidirectional_streams(Config) ->
 	{ok, LocalStreamRef} = quicer:start_stream(Conn,
 		#{open_flag => ?QUIC_STREAM_OPEN_FLAG_UNIDIRECTIONAL}),
 	{ok, _} = quicer:send(LocalStreamRef,
-		<<16#54, 0:2, SessionID:6, "Hello">>,
+		<<1:2, 16#54:14, 0:2, SessionID:6, "Hello">>,
 		?QUIC_SEND_FLAG_FIN),
 	%% Accept an identical unidi stream.
 	{unidi, RemoteStreamRef} = do_receive_new_stream(),
-	{nofin, <<16#54, 0:2, SessionID:6>>} = do_receive_data(RemoteStreamRef),
+	{nofin, <<1:2, 16#54:14, 0:2, SessionID:6>>} = do_receive_data(RemoteStreamRef),
 	{fin, <<"Hello">>} = do_receive_data(RemoteStreamRef),
 	ok.
 
@@ -182,7 +180,7 @@ bidirectional_streams_client(Config) ->
 	} = do_webtransport_connect(Config),
 	%% Create a bidi stream, send Hello, get Hello back.
 	{ok, LocalStreamRef} = quicer:start_stream(Conn, #{}),
-	{ok, _} = quicer:send(LocalStreamRef, <<16#41, 0:2, SessionID:6, "Hello">>),
+	{ok, _} = quicer:send(LocalStreamRef, <<1:2, 16#41:14, 0:2, SessionID:6, "Hello">>),
 	%% @todo Use the local do_receive_data instead to have the fin flag.
 	{ok, <<"Hello">>} = rfc9114_SUITE:do_receive_data(LocalStreamRef),
 	ok.
@@ -197,10 +195,10 @@ bidirectional_streams_server(Config) ->
 	} = do_webtransport_connect(Config),
 	%% Create a bidi stream, send a special instruction to make it create a bidi stream.
 	{ok, LocalStreamRef} = quicer:start_stream(Conn, #{}),
-	{ok, _} = quicer:send(LocalStreamRef, <<16#41, 0:2, SessionID:6, "TEST:open_bidi">>),
+	{ok, _} = quicer:send(LocalStreamRef, <<1:2, 16#41:14, 0:2, SessionID:6, "TEST:open_bidi">>),
 	%% Accept the bidi stream and receive the data.
 	{bidi, RemoteStreamRef} = do_receive_new_stream(),
-	{nofin, <<16#41, 0:2, SessionID:6>>} = do_receive_data(RemoteStreamRef),
+	{nofin, <<1:2, 16#41:14, 0:2, SessionID:6>>} = do_receive_data(RemoteStreamRef),
 	{ok, _} = quicer:send(RemoteStreamRef, <<"Hello">>,
 		?QUIC_SEND_FLAG_FIN),
 	{fin, <<"Hello">>} = do_receive_data(RemoteStreamRef),