Remove net::ServerSocket::setAllowReuseAddress and fix server socket on Windows.

SO_REUSEADDR is useful for server sockets to bind to a recently unbound port. When a socket is closed, the end point changes its state to TIME_WAIT and wait for 2 MSL (maximum segment lifetime) to ensure the remote peer acknowledges its closure. For server sockets, it is usually safe to bind to a TIME_WAIT end point immediately, which is a widely adopted behavior.

On Linux SO_REUSEADDR does not enable the TCP socket to bind to an end point that is already bound by another socket. To do that one must set SO_REUSEPORT instead.

However, on Windows, SO_REUSEADDR works as if both SO_REUSEDPORT and SO_REUSEADDR are set. Furthermore, A bound end point can be hijacked by another process by setting SO_REUSEADDR. Therefore a Windows-only option SO_EXCLUSIVEADDRUSE was introduced in Windows NT 4.0 SP4. If the socket that is bound to the end point has SO_EXCLUSIVEADDRUSE enabled, it is not possible for another socket to forcibly bind to the end point until the end point is unbound. Also, unlike on *nix, on Windows a TCP server socket can always bind to an end point in TIME_WAIT state without setting SO_REUSEADDR, therefore we cannot emulate a similar behavior of disabling SO_REUSEADDR here.


This is considered a security issue and MSDN (http://goo.gl/M6fjQ) recommends all server applications to use SO_EXCLUSIVEADDRUSE.


BUG=173533
TBR=brettw@chromium.org

Review URL: https://chromiumcodereview.appspot.com/15179003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@210147 0039d316-1c4b-4281-b951-d872f2087c98

0 files changed, 0 insertions, 0 deletions