support for TCPMSS target

1 files changed, 38 insertions, 0 deletions

diff --git a/awall/modules/clampmss.lua b/awall/modules/clampmss.lua
new file mode 100644
index 0000000..4f74cb5
--- /dev/null
+++ b/awall/modules/clampmss.lua
@@ -0,0 +1,38 @@
+--[[
+TCP MSS clamping module for Alpine Wall
+Copyright (C) 2012 Kaarle Ritvanen
+Licensed under the terms of GPL2
+]]--
+
+
+module(..., package.seeall)
+
+require 'awall.model'
+
+local model = awall.model
+
+
+local ClampMSSRule = model.class(model.ForwardOnlyRule)
+
+function ClampMSSRule:checkzoneoptfrag(ofrag)
+   if ofrag['in'] then
+      self:error('Cannot specify inbound interface ('..ofrag['in']..')')
+   end
+end
+
+function ClampMSSRule:table() return 'mangle' end
+
+function ClampMSSRule:chain() return 'POSTROUTING' end
+
+function ClampMSSRule:servoptfrags()
+   return {{opts='-p tcp --tcp-flags SYN,RST SYN'}}
+end
+
+function ClampMSSRule:target()
+   return 'TCPMSS --'..(self.mss and 'set-mss '..self.mss or 'clamp-mss-to-pmtu')
+end
+
+
+classes = {{'clamp-mss', ClampMSSRule}}
+
+defrules = {}