socket_helper: tunables for tcp_defer_accept/accept_filter

Under Linux, this allows users to tune the time (in seconds) to
defer connections before allowing them to be accepted.  The
behavior of TCP_DEFER_ACCEPT changed with Linux 2.6.32 and idle
connections may still be accept()-ed after the specified value
in seconds.  A small value of '1' remains the default for
Unicorn as Unicorn does not worry about slow clients.  Higher
values provide better DoS protection for Rainbows! but also
increases kernel memory usage.

Allowing "dataready" for FreeBSD accept filters will allow
SSL sockets to be used in the future for HTTPS, too.

1 files changed, 24 insertions, 0 deletions

diff --git a/test/unit/test_socket_helper.rb b/test/unit/test_socket_helper.rb
index 36b2dc2..bbce359 100644
--- a/test/unit/test_socket_helper.rb
+++ b/test/unit/test_socket_helper.rb
@@ -146,4 +146,28 @@ class TestSocketHelper < Test::Unit::TestCase
     sock_name(@unix_server)
   end
 
+  def test_tcp_defer_accept_default
+    port = unused_port @test_addr
+    name = "#@test_addr:#{port}"
+    sock = bind_listen(name)
+    cur = sock.getsockopt(Socket::SOL_TCP, TCP_DEFER_ACCEPT).unpack('i')[0]
+    assert cur >= 1
+  end if defined?(TCP_DEFER_ACCEPT)
+
+  def test_tcp_defer_accept_disable
+    port = unused_port @test_addr
+    name = "#@test_addr:#{port}"
+    sock = bind_listen(name, :tcp_defer_accept => false)
+    cur = sock.getsockopt(Socket::SOL_TCP, TCP_DEFER_ACCEPT).unpack('i')[0]
+    assert_equal 0, cur
+  end if defined?(TCP_DEFER_ACCEPT)
+
+  def test_tcp_defer_accept_nr
+    port = unused_port @test_addr
+    name = "#@test_addr:#{port}"
+    sock = bind_listen(name, :tcp_defer_accept => 60)
+    cur = sock.getsockopt(Socket::SOL_TCP, TCP_DEFER_ACCEPT).unpack('i')[0]
+    assert cur > 1
+  end if defined?(TCP_DEFER_ACCEPT)
+
 end