--[[ Iptables parser and query library (c) 2008-2009 Jo-Philipp Wich (c) 2008-2009 Steven Barth 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 $Id$ ]]-- local luci = {} luci.util = require "luci.util" luci.sys = require "luci.sys" luci.ip = require "luci.ip" local pcall = pcall local io = require "io" local tonumber, ipairs, table = tonumber, ipairs, table module("luci.sys.iptparser") IptParser = luci.util.class() function IptParser.__init__( self, family ) self._family = (tonumber(family) == 6) and 6 or 4 self._rules = { } self._chains = { } self._tables = { } local t = self._tables local s = self:_supported_tables(self._family) if s.filter then t[#t+1] = "filter" end if s.nat then t[#t+1] = "nat" end if s.mangle then t[#t+1] = "mangle" end if s.raw then t[#t+1] = "raw" end if self._family == 4 then self._nulladdr = "0.0.0.0/0" self._command = "iptables -t %s --line-numbers -nxvL" else self._nulladdr = "::/0" self._command = "ip6tables -t %s --line-numbers -nxvL" end self:_parse_rules() end function IptParser._supported_tables( self, family ) local tables = { } local ok, lines = pcall(io.lines, (family == 6) and "/proc/net/ip6_tables_names" or "/proc/net/ip_tables_names") if ok and lines then local line for line in lines do tables[line] = true end end return tables end -- 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: -- -- The return value is a list of tables representing the matched rules. -- Each rule table contains the following fields: -- -- Example: --
-- ip = luci.sys.iptparser.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 = { } args.source = args.source and self:_parse_addr(args.source) args.destination = args.destination and self:_parse_addr(args.destination) for i, rule in ipairs(self._rules) do local match = true -- match table if not ( not args.table or args.table:lower() == 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:lower() == rule.protocol ) ) then match = false end -- match source if not ( match == true and ( not args.source or rule.source == self._nulladdr or self:_parse_addr(rule.source):contains(args.source) ) ) then match = false end -- match destination if not ( match == true and ( not args.destination or rule.destination == self._nulladdr or self:_parse_addr(rule.destination):contains(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 rv[#rv+1] = rule end end return rv end -- through external commands. function IptParser.resync( self ) self._rules = { } self._chain = nil self:_parse_rules() end function IptParser.tables( self ) return self._tables end function IptParser.chains( self, table ) local lookup = { } local chains = { } for _, r in ipairs(self:find({table=table})) do if not lookup[r.chain] then lookup[r.chain] = true chains[#chains+1] = r.chain end end return chains end -- and "rules". The "rules" field is a table of rule tables. function IptParser.chain( self, table, chain ) return self._chains[table:lower()] and self._chains[table:lower()][chain] end function IptParser.is_custom_target( self, target ) for _, r in ipairs(self._rules) do if r.chain == target then return true end end return false end -- [internal] Parse address according to family. function IptParser._parse_addr( self, addr ) if self._family == 4 then return luci.ip.IPv4(addr) else return luci.ip.IPv6(addr) end end -- [internal] Parse iptables output from all tables. function IptParser._parse_rules( self ) for i, tbl in ipairs(self._tables) do self._chains[tbl] = { } for i, rule in ipairs(luci.util.execl(self._command % tbl)) do if rule:find( "^Chain " ) == 1 then local crefs local cname, cpol, cpkt, cbytes = rule:match( "^Chain ([^%s]*) %(policy (%w+) " .. "(%d+) packets, (%d+) bytes%)" ) if not cname then cname, crefs = rule:match( "^Chain ([^%s]*) %((%d+) references%)" ) end self._chain = cname self._chains[tbl][cname] = { policy = cpol, packets = tonumber(cpkt or 0), bytes = tonumber(cbytes or 0), references = tonumber(crefs or 0), rules = { } } else if rule:find("%d") == 1 then local rule_parts = luci.util.split( rule, "%s+", nil, true ) local rule_details = { } -- cope with rules that have no target assigned if rule:match("^%d+%s+%d+%s+%d+%s%s") then table.insert(rule_parts, 4, nil) end -- ip6tables opt column is usually zero-width if self._family == 6 then table.insert(rule_parts, 6, "--") end rule_details["table"] = tbl rule_details["chain"] = self._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 do if #rule_parts[i] > 0 then rule_details["options"][i-10] = rule_parts[i] end end self._rules[#self._rules+1] = rule_details self._chains[tbl][self._chain].rules[ #self._chains[tbl][self._chain].rules + 1 ] = rule_details end end end end self._chain = nil end -- [internal] Return true if optlist1 contains all elements of optlist 2. -- 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