[Mono-bugs] [Bug 81891][Wis] New - SO_REUSEADDR should also set SO_REUSEPORT on FreeBSD UDP sockets

[bugzilla-daemon at bugzilla.ximian.com]

Please do not reply to this email- if you want to comment on the bug, go to the
URL shown below and enter your comments there.

Changed by jim at 32bitkid.com.

http://bugzilla.ximian.com/show_bug.cgi?id=81891

--- shadow/81891	2007-06-16 13:26:58.000000000 -0400
+++ shadow/81891.tmp.27082	2007-06-16 13:26:58.000000000 -0400
@@ -0,0 +1,80 @@
+Bug#: 81891
+Product: Mono: Class Libraries
+Version: 1.2
+OS: other
+OS Details: FreeBSD 6.2
+Status: NEW   
+Resolution: 
+Severity: 
+Priority: Wishlist
+Component: System
+AssignedTo: mono-bugs at ximian.com                            
+ReportedBy: jim at 32bitkid.com               
+QAContact: mono-bugs at ximian.com
+TargetMilestone: ---
+URL: 
+Cc: 
+Summary: SO_REUSEADDR should also set SO_REUSEPORT on FreeBSD UDP sockets
+
+Description of Problem:
+When dealing with multicast udp sockets, its common to set the socket 
+option SO_REUSEADDR to allow multiple sockets/applications on one 
+interface to bind to the same address and recieve the same multicast (or 
+broadcast) datagrams.
+
+On Linux and Windows, setting SocketOptionName.ReuseAddress to 1 will 
+allow this behaviour: Multiple sockets/applications can bind to the same 
+address:port. 
+
+However, on freebsd this functionality is slightly different. SO_REUSEADDR 
+allows a socket to bind to a socket that is in a TIME_WAIT state, whereas 
+SO_REUSEPORT allows a socket to bind to a address and port that are 
+already in use.
+
+On Linux and Windows, setting SO_REUSEADDR implies that SO_REUSEPORT has 
+been set. However, on FreeBSD both have to be set separately. However, 
+mono does not allow for arbitrary socketoptions to be set, so which ever 
+application binds to the address/port first will have exclusive access to 
+it, which is different functionality than Windows/Linux, effectively 
+breaking the usefulness of UDP multicast on freebsd.
+
+
+Steps to reproduce the problem:
+EndPoint multicast = new IPEndPoint(IPAddress.Any, 9090);
+
+socket_a = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, 
+ProtocolType.Udp);
+socket_a.SetSocketOption(SocketOptionLevel.Socket, 
+SocketOptionName.ReuseAddress, 1);
+socket_a.SetSocketOption(SocketOptionLevel.IP, 
+SocketOptionName.MulticastLoopback, 1);
+socket_a.SetSocketOption(SocketOptionLevel.IP, 
+SocketOptionName.MulticastTimeToLive, 1);            
+socket_a.Bind(multicast);
+
+socket_b = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, 
+ProtocolType.Udp);
+socket_b.SetSocketOption(SocketOptionLevel.Socket, 
+SocketOptionName.ReuseAddress, 1);
+socket_b.SetSocketOption(SocketOptionLevel.IP, 
+SocketOptionName.MulticastLoopback, 1);
+socket_b.SetSocketOption(SocketOptionLevel.IP, 
+SocketOptionName.MulticastTimeToLive, 1);            
+socket_b.Bind(multicast);
+
+Actual Results:
+Windows/Linux success.
+
+FreeBSD throws a SocketException
+
+Expected Results:
+Windows/Linux/FreeBSD success.
+
+How often does this happen? 
+Every time
+
+Additional Information:
+Setting SO_REUSEPORT with SO_REUSEADDR should only be assumed with the 
+socket type is SocketType.Dgram. Stream protocols like TCP should only set 
+SO_REUSEADDR (setting SO_REUSEPORT on stream protocols could be concidered 
+a security risk)