Keep track of the intermediaries the connection go through

Also augment the CONNECT tests to confirm that the
intermediaries are accounted for.

5 files changed, 119 insertions, 12 deletions

diff --git a/src/gun.erl b/src/gun.erl
index 9c92281..daa5c62 100644
--- a/src/gun.erl
+++ b/src/gun.erl
@@ -128,6 +128,14 @@
 }.
 -export_type([connect_destination/0]).
 
+-type intermediary() :: #{
+	type := connect,
+	host := inet:hostname() | inet:ip_address(),
+	port := inet:port_number(),
+	transport := tcp | tls,
+	protocol := http | http2
+}.
+
 %% @todo When/if HTTP/2 CONNECT gets implemented, we will want an option here
 %% to indicate that the request must be sent on an existing CONNECT stream.
 %% This is of course not required for HTTP/1.1 since the CONNECT takes over
@@ -163,6 +171,7 @@
 	port :: inet:port_number(),
 	origin_host :: inet:hostname() | inet:ip_address(),
 	origin_port :: inet:port_number(),
+	intermediaries = [] :: [intermediary()],
 	opts :: opts(),
 	keepalive_ref :: undefined | reference(),
 	socket :: undefined | inet:socket() | ssl:sslsocket(),
@@ -275,9 +284,25 @@ consider_tracing(_, _) ->
 
 -spec info(pid()) -> map().
 info(ServerPid) ->
-	{_, #state{socket=Socket, transport=Transport}} = sys:get_state(ServerPid),
+	{_, #state{
+		socket=Socket,
+		transport=Transport,
+		protocol=Protocol,
+		origin_host=OriginHost,
+		origin_port=OriginPort,
+		intermediaries=Intermediaries
+	}} = sys:get_state(ServerPid),
 	{ok, {SockIP, SockPort}} = Transport:sockname(Socket),
-	#{sock_ip => SockIP, sock_port => SockPort}.
+	#{
+		transport => Transport:name(),
+		protocol => Protocol:name(),
+		sock_ip => SockIP,
+		sock_port => SockPort,
+		origin_host => OriginHost,
+		origin_port => OriginPort,
+		%% Intermediaries are listed in the order data goes through them.
+		intermediaries => lists:reverse(Intermediaries)
+	}.
 
 -spec close(pid()) -> ok.
 close(ServerPid) ->
@@ -866,8 +891,23 @@ commands([Error={error, _}|_], State=#state{socket=Socket, transport=Transport})
 commands([{state, ProtoState}|Tail], State) ->
 	commands(Tail, State#state{protocol_state=ProtoState});
 %% @todo The scheme should probably not be ignored.
-commands([{origin, _Scheme, Host, Port}|Tail], State) ->
-	commands(Tail, State#state{origin_host=Host, origin_port=Port});
+%%
+%% Order is important: the origin must be changed before
+%% the transport and/or protocol in order to keep track
+%% of the intermediaries properly.
+commands([{origin, _Scheme, Host, Port, Type}|Tail],
+		State=#state{transport=Transport, protocol=Protocol,
+			origin_host=IntermediateHost, origin_port=IntermediatePort,
+			intermediaries=Intermediaries}) ->
+	Info = #{
+		type => Type,
+		host => IntermediateHost,
+		port => IntermediatePort,
+		transport => Transport:name(),
+		protocol => Protocol:name()
+	},
+	commands(Tail, State#state{origin_host=Host, origin_port=Port,
+		intermediaries=[Info|Intermediaries]});
 commands([{switch_transport, Transport, Socket}|Tail], State) ->
 	commands(Tail, State#state{socket=Socket, transport=Transport});
 %% @todo The two loops should be reunified and this clause generalized.
diff --git a/src/gun_http.erl b/src/gun_http.erl
index c2b0ed6..c4291bc 100644
--- a/src/gun_http.erl
+++ b/src/gun_http.erl
@@ -229,13 +229,13 @@ handle_head(Data, State=#http_state{socket=Socket, version=ClientVersion,
 						{ok, TLSSocket} ->
 							case ssl:negotiated_protocol(TLSSocket) of
 								{ok, <<"h2">>} ->
-									[{switch_transport, gun_tls, TLSSocket},
-										{switch_protocol, gun_http2, State2},
-										{origin, <<"https">>, NewHost, NewPort}];
+									[{origin, <<"https">>, NewHost, NewPort, connect},
+										{switch_transport, gun_tls, TLSSocket},
+										{switch_protocol, gun_http2, State2}];
 								_ ->
 									[{state, State2#http_state{socket=TLSSocket, transport=gun_tls}},
-										{switch_transport, gun_tls, TLSSocket},
-										{origin, <<"https">>, NewHost, NewPort}]
+										{origin, <<"https">>, NewHost, NewPort, connect},
+										{switch_transport, gun_tls, TLSSocket}]
 							end;
 						Error ->
 							Error
@@ -244,10 +244,10 @@ handle_head(Data, State=#http_state{socket=Socket, version=ClientVersion,
 					case maps:get(protocols, Destination, [http]) of
 						[http] ->
 							[{state, State2},
-								{origin, <<"http">>, NewHost, NewPort}];
+								{origin, <<"http">>, NewHost, NewPort, connect}];
 						[http2] ->
-							[{switch_protocol, gun_http2, State2},
-								{origin, <<"http">>, NewHost, NewPort}]
+							[{origin, <<"http">>, NewHost, NewPort, connect},
+								{switch_protocol, gun_http2, State2}]
 					end
 			end;
 		{_, _} when Status >= 100, Status =< 199 ->
diff --git a/src/gun_tcp.erl b/src/gun_tcp.erl
index 80bc45b..0f5addc 100644
--- a/src/gun_tcp.erl
+++ b/src/gun_tcp.erl
@@ -14,6 +14,7 @@
 
 -module(gun_tcp).
 
+-export([name/0]).
 -export([messages/0]).
 -export([connect/4]).
 -export([send/2]).
@@ -21,6 +22,8 @@
 -export([sockname/1]).
 -export([close/1]).
 
+name() -> tcp.
+
 messages() -> {tcp, tcp_closed, tcp_error}.
 
 -spec connect(inet:ip_address() | inet:hostname(),
diff --git a/src/gun_tls.erl b/src/gun_tls.erl
index f58620f..d377927 100644
--- a/src/gun_tls.erl
+++ b/src/gun_tls.erl
@@ -14,6 +14,7 @@
 
 -module(gun_tls).
 
+-export([name/0]).
 -export([messages/0]).
 -export([connect/3]).
 -export([connect/4]).
@@ -22,6 +23,8 @@
 -export([sockname/1]).
 -export([close/1]).
 
+name() -> tls.
+
 messages() -> {ssl, ssl_closed, ssl_error}.
 
 -spec connect(inet:socket(), any(), timeout())
diff --git a/test/rfc7231_SUITE.erl b/test/rfc7231_SUITE.erl
index 88bc114..a42e06c 100644
--- a/test/rfc7231_SUITE.erl
+++ b/test/rfc7231_SUITE.erl
@@ -178,6 +178,18 @@ do_connect_http(Transport) ->
 	Len = byte_size(Authority),
 	<<"GET /proxied HTTP/1.1\r\nhost: ", Authority:Len/binary, "\r\n", _/bits>>
 		= do_receive(OriginPid),
+	#{
+		transport := Transport,
+		protocol := http,
+		origin_host := "localhost",
+		origin_port := OriginPort,
+		intermediaries := [#{
+			type := connect,
+			host := "localhost",
+			port := ProxyPort,
+			transport := tcp,
+			protocol := http
+	}]} = gun:info(ConnPid),
 	gun:close(ConnPid).
 
 connect_h2c(_) ->
@@ -214,6 +226,18 @@ do_connect_h2(Transport) ->
 		<<_:Len/binary, _:24, 1:8, _/bits>> ->
 			ok
 	end,
+	#{
+		transport := Transport,
+		protocol := http2,
+		origin_host := "localhost",
+		origin_port := OriginPort,
+		intermediaries := [#{
+			type := connect,
+			host := "localhost",
+			port := ProxyPort,
+			transport := tcp,
+			protocol := http
+	}]} = gun:info(ConnPid),
 	gun:close(ConnPid).
 
 connect_through_multiple_proxies(_) ->
@@ -243,6 +267,24 @@ connect_through_multiple_proxies(_) ->
 	Len = byte_size(Authority2),
 	<<"GET /proxied HTTP/1.1\r\nhost: ", Authority2:Len/binary, "\r\n", _/bits>>
 		= do_receive(OriginPid),
+	#{
+		transport := tcp,
+		protocol := http,
+		origin_host := "localhost",
+		origin_port := OriginPort,
+		intermediaries := [#{
+			type := connect,
+			host := "localhost",
+			port := Proxy1Port,
+			transport := tcp,
+			protocol := http
+		}, #{
+			type := connect,
+			host := "localhost",
+			port := Proxy2Port,
+			transport := tcp,
+			protocol := http
+	}]} = gun:info(ConnPid),
 	gun:close(ConnPid).
 
 connect_response_201(_) ->
@@ -263,6 +305,18 @@ connect_response_201(_) ->
 	Len = byte_size(Authority),
 	<<"GET /proxied HTTP/1.1\r\nhost: ", Authority:Len/binary, "\r\n", _/bits>>
 		= do_receive(OriginPid),
+	#{
+		transport := tcp,
+		protocol := http,
+		origin_host := "localhost",
+		origin_port := OriginPort,
+		intermediaries := [#{
+			type := connect,
+			host := "localhost",
+			port := ProxyPort,
+			transport := tcp,
+			protocol := http
+	}]} = gun:info(ConnPid),
 	gun:close(ConnPid).
 
 connect_response_302(_) ->
@@ -295,6 +349,13 @@ do_connect_failure(Status) ->
 	{response, fin, Status, Headers} = gun:await(ConnPid, StreamRef),
 	FailedStreamRef = gun:get(ConnPid, "/proxied"),
 	{response, fin, 501, _} = gun:await(ConnPid, FailedStreamRef),
+	#{
+		transport := tcp,
+		protocol := http,
+		origin_host := "localhost",
+		origin_port := ProxyPort,
+		intermediaries := []
+	} = gun:info(ConnPid),
 	gun:close(ConnPid).
 
 connect_authority_form(_) ->