--- /dev/null
+--[[
+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
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