From 944a57a11a79c5a9bb2f554c921e2e00e7d56c91 Mon Sep 17 00:00:00 2001
From: Ricardo <ricardo@macbook.local>
Date: Sat, 4 Feb 2012 16:32:21 +0100
Subject: Fix port leaking after controlling_process(Port, self())

Add case to handle the situation when someone call
{gen_tcp,gen_udp}:controlling_process(Port, self()). Also improve spec
and doc from gen_udp and gen_sctp for controlling_process/2.

To reproduce the issue, open an UDP port:

4> {ok,Port} = gen_udp:open(9000, [binary]).
{ok,#Port<0.587>}
5> gen_udp:controlling_process(Port, self()).
ok

Simulate error:

6> 1=2.
** exception error: no match of right hand side value 2

Here is the leak:

7> inet:i().
Port Module   Recv Sent Owner    Local Address Foreign Address State
Type
581  inet_udp 0    0    <0.31.0> *:cslistener  *:*             BOUND
DGRAM
ok
---
 lib/kernel/src/gen_sctp.erl | 5 +++--
 lib/kernel/src/gen_udp.erl  | 5 +++--
 lib/kernel/src/inet.erl     | 4 ++++
 3 files changed, 10 insertions(+), 4 deletions(-)

(limited to 'lib/kernel/src')

diff --git a/lib/kernel/src/gen_sctp.erl b/lib/kernel/src/gen_sctp.erl
index d8954f0cf7..8fa963ec78 100644
--- a/lib/kernel/src/gen_sctp.erl
+++ b/lib/kernel/src/gen_sctp.erl
@@ -425,9 +425,10 @@ error_string(X) ->
     erlang:error(badarg, [X]).
 
 
--spec controlling_process(Socket, Pid) -> ok when
+-spec controlling_process(Socket, Pid) -> ok | {error, Reason} when
       Socket :: sctp_socket(),
-      Pid :: pid().
+      Pid :: pid(),
+      Reason :: closed | not_owner | inet:posix().
 
 controlling_process(S, Pid) when is_port(S), is_pid(Pid) ->
     inet:udp_controlling_process(S, Pid);
diff --git a/lib/kernel/src/gen_udp.erl b/lib/kernel/src/gen_udp.erl
index 8688799ae9..914854c65c 100644
--- a/lib/kernel/src/gen_udp.erl
+++ b/lib/kernel/src/gen_udp.erl
@@ -185,9 +185,10 @@ connect(S, Address, Port) when is_port(S) ->
 	    Error
     end.
 
--spec controlling_process(Socket, Pid) -> ok when
+-spec controlling_process(Socket, Pid) -> ok | {error, Reason} when
       Socket :: socket(),
-      Pid :: pid().
+      Pid :: pid(),
+      Reason :: closed | not_owner | inet:posix().
 
 controlling_process(S, NewOwner) ->
     inet:udp_controlling_process(S, NewOwner).
diff --git a/lib/kernel/src/inet.erl b/lib/kernel/src/inet.erl
index 49f64a9236..3356fb55d7 100644
--- a/lib/kernel/src/inet.erl
+++ b/lib/kernel/src/inet.erl
@@ -1244,6 +1244,8 @@ udp_close(S) when is_port(S) ->
 %% Set controlling process for TCP socket.
 tcp_controlling_process(S, NewOwner) when is_port(S), is_pid(NewOwner) ->
     case erlang:port_info(S, connected) of
+	{connected, NewOwner} ->
+	    ok;
 	{connected, Pid} when Pid =/= self() ->
 	    {error, not_owner};
 	undefined ->
@@ -1295,6 +1297,8 @@ tcp_sync_input(S, Owner, Flag) ->
 %% Set controlling process for UDP or SCTP socket.
 udp_controlling_process(S, NewOwner) when is_port(S), is_pid(NewOwner) ->
     case erlang:port_info(S, connected) of
+	{connected, NewOwner} ->
+	    ok;
 	{connected, Pid} when Pid =/= self() ->
 	    {error, not_owner};
 	_ ->
-- 
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