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