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Diffstat (limited to 'modules/luci-base/luasrc/sys/iptparser.lua')
| -rw-r--r-- | modules/luci-base/luasrc/sys/iptparser.lua | 373 |
1 files changed, 373 insertions, 0 deletions
diff --git a/modules/luci-base/luasrc/sys/iptparser.lua b/modules/luci-base/luasrc/sys/iptparser.lua new file mode 100644 index 000000000..d82363309 --- /dev/null +++ b/modules/luci-base/luasrc/sys/iptparser.lua @@ -0,0 +1,373 @@ +--[[ + +Iptables parser and query library +(c) 2008-2009 Jo-Philipp Wich <xm@leipzig.freifunk.net> +(c) 2008-2009 Steven Barth <steven@midlink.org> + +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 tonumber, ipairs, table = tonumber, ipairs, table + +--- LuCI iptables parser and query library +-- @cstyle instance +module("luci.sys.iptparser") + +--- Create a new iptables parser object. +-- @class function +-- @name IptParser +-- @param family Number specifying the address family. 4 for IPv4, 6 for IPv6 +-- @return IptParser instance +IptParser = luci.util.class() + +function IptParser.__init__( self, family ) + self._family = (tonumber(family) == 6) and 6 or 4 + self._rules = { } + self._chains = { } + + if self._family == 4 then + self._nulladdr = "0.0.0.0/0" + self._tables = { "filter", "nat", "mangle", "raw" } + self._command = "iptables -t %s --line-numbers -nxvL" + else + self._nulladdr = "::/0" + self._tables = { "filter", "mangle", "raw" } + self._command = "ip6tables -t %s --line-numbers -nxvL" + end + + self:_parse_rules() +end + +--- 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: +-- <ul> +-- <li> table - Match rules that are located within the given table +-- <li> chain - Match rules that are located within the given chain +-- <li> target - Match rules with the given target +-- <li> protocol - Match rules that match the given protocol, rules with +-- protocol "all" are always matched +-- <li> source - Match rules with the given source, rules with source +-- "0.0.0.0/0" (::/0) are always matched +-- <li> destination - Match rules with the given destination, rules with +-- destination "0.0.0.0/0" (::/0) are always matched +-- <li> inputif - Match rules with the given input interface, rules +-- with input interface "*" (=all) are always matched +-- <li> outputif - Match rules with the given output interface, rules +-- with output interface "*" (=all) are always matched +-- <li> flags - Match rules that match the given flags, current +-- supported values are "-f" (--fragment) +-- and "!f" (! --fragment) +-- <li> options - Match rules containing all given options +-- </ul> +-- The return value is a list of tables representing the matched rules. +-- Each rule table contains the following fields: +-- <ul> +-- <li> index - The index number of the rule +-- <li> table - The table where the rule is located, can be one +-- of "filter", "nat" or "mangle" +-- <li> chain - The chain where the rule is located, e.g. "INPUT" +-- or "postrouting_wan" +-- <li> target - The rule target, e.g. "REJECT" or "DROP" +-- <li> protocol The matching protocols, e.g. "all" or "tcp" +-- <li> flags - Special rule options ("--", "-f" or "!f") +-- <li> inputif - Input interface of the rule, e.g. "eth0.0" +-- or "*" for all interfaces +-- <li> outputif - Output interface of the rule,e.g. "eth0.0" +-- or "*" for all interfaces +-- <li> source - The source ip range, e.g. "0.0.0.0/0" (::/0) +-- <li> destination - The destination ip range, e.g. "0.0.0.0/0" (::/0) +-- <li> options - A list of specific options of the rule, +-- e.g. { "reject-with", "tcp-reset" } +-- <li> packets - The number of packets matched by the rule +-- <li> bytes - The number of total bytes matched by the rule +-- </ul> +-- Example: +-- <pre> +-- ip = luci.sys.iptparser.IptParser() +-- result = ip.find( { +-- target="REJECT", +-- protocol="tcp", +-- options={ "reject-with", "tcp-reset" } +-- } ) +-- </pre> +-- This will match all rules with target "-j REJECT", +-- protocol "-p tcp" (or "-p all") +-- and the option "--reject-with tcp-reset". +-- @params args Table containing the search arguments (optional) +-- @return Table of matching rule tables +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 + + +--- Rebuild the internal lookup table, for example when rules have changed +-- through external commands. +-- @return nothing +function IptParser.resync( self ) + self._rules = { } + self._chain = nil + self:_parse_rules() +end + + +--- Find the names of all tables. +-- @return Table of table names. +function IptParser.tables( self ) + return self._tables +end + + +--- Find the names of all chains within the given table name. +-- @param table String containing the table name +-- @return Table of chain names in the order they occur. +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 + + +--- Return the given firewall chain within the given table name. +-- @param table String containing the table name +-- @param chain String containing the chain name +-- @return Table containing the fields "policy", "packets", "bytes" +-- 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 + + +--- Test whether the given target points to a custom chain. +-- @param target String containing the target action +-- @return Boolean indicating whether target is a custom chain. +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 |