* ffluci: added iptparser library to core

1 files changed, 243 insertions, 0 deletions

diff --git a/core/src/iptparser.lua b/core/src/iptparser.lua
new file mode 100644
index 000000000..ab77a7404
--- /dev/null
+++ b/core/src/iptparser.lua
@@ -0,0 +1,243 @@
+--[[
+FFLuCI - Iptables parser and query library
+
+Copyright 2008 Jo-Philipp Wich <freifunk@wwsnet.net>
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+        http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+
+$Id$
+
+]]--
+
+module("ffluci.iptparser", package.seeall)
+require("ffluci.sys")
+require("ffluci.util")
+
+
+IptParser = ffluci.util.class()
+
+--[[
+IptParser.__init__( ... )
+
+The class constructor, initializes the internal lookup table.
+]]--
+
+function IptParser.__init__( self, ... )
+	self._rules = { }
+	self._chain = nil
+	self:_parse_rules()
+end
+
+
+--[[
+IptParser.find( args )
+
+Find all firewall rules that match the given criteria. Expects a table with search criteria as only argument.
+If args is nil or an empty table then all rules will be returned.
+
+The following keys in the args table are recognized:
+
+ - table	Match rules that are located within the given table
+ - chain	Match rules that are located within the given chain
+ - target	Match rules with the given target
+ - protocol	Match rules that match the given protocol, rules with protocol "all" are always matched
+ - source	Match rules with the given source, rules with source "0.0.0.0/0" are always matched
+ - destination	Match rules with the given destination, rules with destination "0.0.0.0/0" are always matched
+ - inputif	Match rules with the given input interface, rules with input interface "*" (=all) are always matched
+ - outputif	Match rules with the given output interface, rules with output interface "*" (=all) are always matched
+ - flags	Match rules that match the given flags, current supported values are "-f" (--fragment) and "!f" (! --fragment)
+ - options	Match rules containing all given options
+
+The return value is a list of tables representing the matched rules.
+Each rule table contains the following fields:
+
+ - index	The index number of the rule
+ - table	The table where the rule is located, can be one of "filter", "nat" or "mangle"
+ - chain	The chain where the rule is located, e.g. "INPUT" or "postrouting_wan"
+ - target	The rule target, e.g. "REJECT" or "DROP"
+ - protocol	The matching protocols, e.g. "all" or "tcp"
+ - flags	Special rule options ("--", "-f" or "!f")
+ - inputif	Input interface of the rule, e.g. "eth0.0" or "*" for all interfaces
+ - outputif	Output interface of the rule, e.g. "eth0.0" or "*" for all interfaces
+ - source	The source ip range, e.g. "0.0.0.0/0"
+ - destination	The destination ip range, e.g. "0.0.0.0/0"
+ - options	A list of specific options of the rule, e.g. { "reject-with", "tcp-reset" }
+ - packets	The number of packets matched by the rule
+ - bytes	The number of total bytes matched by the rule
+
+Example:
+
+ip = IptParser();
+result = ip.find( {
+	target="REJECT",
+	protocol="tcp",
+	options={ "reject-with", "tcp-reset" }
+} )
+
+This will match all rules with target "-j REJECT", protocol "-p tcp" (or "-p all") and the option "--reject-with tcp-reset".
+
+]]--
+
+function IptParser.find( self, args )
+
+	local args = args or { }
+	local rv   = { }
+
+	for i, rule in ipairs(self._rules) do
+		local match = true
+
+		-- match table
+		if not ( not args.table or args.table == rule.table ) then
+			match = false
+		end
+
+		-- match chain
+		if not ( match == true and ( not args.chain or args.chain == rule.chain ) ) then
+			match = false
+		end
+
+		-- match target
+		if not ( match == true and ( not args.target or args.target == rule.target ) ) then
+			match = false
+		end
+
+		-- match protocol
+		if not ( match == true and ( not args.protocol or rule.protocol == "all" or args.protocol == rule.protocol ) ) then
+			match = false
+		end
+		
+		-- match source (XXX: implement ipcalc stuff so that 192.168.1.0/24 matches 0.0.0.0/0 etc.)
+		if not ( match == true and ( not args.source or rule.source == "0.0.0.0/0" or rule.source == args.source ) ) then
+			match = false
+		end
+
+		-- match destination (XXX: implement ipcalc stuff so that 192.168.1.0/24 matches 0.0.0.0/0 etc.)
+		if not ( match == true and ( not args.destination or rule.destination == "0.0.0.0/0" or rule.destination == args.destination ) ) then
+			match = false
+		end
+
+		-- match input interface
+		if not ( match == true and ( not args.inputif or rule.inputif == "*" or args.inputif == rule.inputif ) ) then
+			match = false
+		end
+
+		-- match output interface
+		if not ( match == true and ( not args.outputif or rule.outputif == "*" or args.outputif == rule.outputif ) ) then
+			match = false
+		end
+
+		-- match flags (the "opt" column)
+		if not ( match == true and ( not args.flags or rule.flags == args.flags ) ) then
+			match = false
+		end
+
+		-- match specific options
+		if not ( match == true and ( not args.options or self:_match_options( rule.options, args.options ) ) ) then
+			match = false
+		end
+
+
+		-- insert match
+		if match == true then
+			table.insert( rv, rule )
+		end
+	end
+
+	return rv
+end
+
+
+--[[
+IptParser.resync()
+
+Rebuild the internal lookup table, for example when rules have changed through external commands.
+]]--
+
+function IptParser.resync( self )
+	self._rules = { }
+	self._chain = nil
+	self:_parse_rules()
+end
+
+
+--[[
+IptParser._parse_rules()
+
+[internal] Parse iptables output from all tables.
+]]--
+
+function IptParser._parse_rules( self )
+
+	for i, tbl in ipairs({ "filter", "nat", "mangle" }) do
+
+		for i, rule in ipairs(ffluci.sys.execl("iptables -t " .. tbl .. " --line-numbers -nxvL")) do
+
+			if rule:find( "Chain " ) == 1 then
+		
+				self._chain = rule:gsub("Chain ([^%s]*) .*", "%1")
+
+			else
+				if rule:find("%d") == 1 then
+
+					local rule_parts   = ffluci.util.split( rule, "%s+", nil, true )
+					local rule_details = { }
+
+					rule_details["table"]       = tbl
+					rule_details["chain"]       = _chain
+					rule_details["index"]       = tonumber(rule_parts[1])
+					rule_details["packets"]     = tonumber(rule_parts[2])
+					rule_details["bytes"]       = tonumber(rule_parts[3])
+					rule_details["target"]      = rule_parts[4]
+					rule_details["protocol"]    = rule_parts[5]
+					rule_details["flags"]       = rule_parts[6]
+					rule_details["inputif"]     = rule_parts[7]
+					rule_details["outputif"]    = rule_parts[8]
+					rule_details["source"]      = rule_parts[9]
+					rule_details["destination"] = rule_parts[10]
+					rule_details["options"]     = { }
+
+					for i = 11, #rule_parts - 1 do 
+						rule_details["options"][i-10] = rule_parts[i]
+					end
+
+					table.insert( self._rules, rule_details )
+				end
+			end
+		end
+	end
+end
+
+
+--[[
+IptParser._match_options( optlist1, optlist2 )
+
+[internal] Return true if optlist1 contains all elements of optlist2. Return false in all other cases.
+]]--
+
+function IptParser._match_options( self, o1, o2 )
+
+	-- construct a hashtable of first options list to speed up lookups
+	local oh = { }
+	for i, opt in ipairs( o1 ) do oh[opt] = true end
+
+	-- iterate over second options list
+	-- each string in o2 must be also present in o1
+	-- if o2 contains a string which is not found in o1 then return false
+	for i, opt in ipairs( o2 ) do
+		if not oh[opt] then
+			return false
+		end
+	end
+
+	return true
+end