minenux/minetest-mod-auth_rx
minenux/minetest-mod-auth_rx
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minetest-mod-auth_rx/filter.lua

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--------------------------------------------------------
-- Minetest :: Auth Redux Mod v2.13 (auth_rx)
--
-- See README.txt for licensing and release notes.
-- Copyright (c) 2017-2018, Leslie E. Krause
--------------------------------------------------------
FILTER_TYPE_STRING = 10
FILTER_TYPE_NUMBER = 11
FILTER_TYPE_ADDRESS = 12
FILTER_TYPE_BOOLEAN = 13
FILTER_TYPE_PATTERN = 14
FILTER_TYPE_SERIES = 15
FILTER_TYPE_PERIOD = 16
FILTER_TYPE_MOMENT = 17
FILTER_TYPE_DATESPEC = 18
FILTER_TYPE_TIMESPEC = 19
FILTER_MODE_FAIL = 20
FILTER_MODE_PASS = 21
FILTER_BOOL_AND = 30
FILTER_BOOL_OR = 31
FILTER_BOOL_XOR = 32
FILTER_BOOL_NOW = 33
FILTER_COND_FALSE = 40
FILTER_COND_TRUE = 41
FILTER_COMP_EQ = 50
FILTER_COMP_GT = 51
FILTER_COMP_GTE = 52
FILTER_COMP_LT = 53
FILTER_COMP_LTE = 54
FILTER_COMP_IN = 55
FILTER_COMP_IS = 56
FILTER_COMP_HAS = 57
local decode_base64 = minetest.decode_base64
local encode_base64 = minetest.encode_base64
----------------------------
-- StringPattern class
----------------------------
function StringPattern( phrase, is_mode, tokens )
local glob = "^" .. string.gsub( phrase, ".", tokens ) .. "$"
return { compare = function ( value, type )
if not is_mode[ type ] then return end
return string.find( value, glob ) == 1
end }
end
----------------------------
-- NumberPattern class
----------------------------
function NumberPattern( phrase, is_mode, tokens, parser )
local glob = { }
local ref
local find_token = function ( str, pat )
ref = { string.match( str, pat ) }
return #ref > 0
end
if #phrase ~= #tokens then
return nil
end
for i, v in ipairs( phrase ) do
local eval, args
local t = tokens[ i ]
if find_token( v, "^(" .. t .. ")$" ) then
eval = function ( a, b ) return a == b end
args = { tonumber( ref[ 1 ] ) }
elseif find_token( v, "^(" .. t .. ")%^(" .. t .. ")$" ) then
eval = function ( a, b, c ) return a >= b and a <= c end
args = { tonumber( ref[ 1 ] ), tonumber( ref[ 2 ] ) }
elseif find_token( v, "^(" .. t .. ")([<>])$" ) then
eval = ref[ 2 ] == "<" and
( function ( a, b ) return a <= b end ) or
( function ( a, b ) return a >= b end )
args = { tonumber( ref[ 1 ] ) }
elseif v == "?" then
eval = function ( ) return true end
args = { }
else
return nil
end
table.insert( glob, { eval = eval, args = args } )
end
return { compare = function ( value, type )
if not is_mode[ type ] then return end
local fields = parser( value, type )
for i, v in ipairs( glob ) do
if not v.eval( fields[ i ], unpack( v.args ) ) then return false end
end
return true
end }
end
----------------------------
-- GenericFilter class
----------------------------
function GenericFilter( )
local self = { }
local trim, localtime, redate
local funcs = {
["add"] = { type = FILTER_TYPE_NUMBER, args = { FILTER_TYPE_NUMBER, FILTER_TYPE_NUMBER }, def = function ( v, a, b ) return a + b end },
["sub"] = { type = FILTER_TYPE_NUMBER, args = { FILTER_TYPE_NUMBER, FILTER_TYPE_NUMBER }, def = function ( v, a, b ) return a - b end },
["mul"] = { type = FILTER_TYPE_NUMBER, args = { FILTER_TYPE_NUMBER, FILTER_TYPE_NUMBER }, def = function ( v, a, b ) return a * b end },
["div"] = { type = FILTER_TYPE_NUMBER, args = { FILTER_TYPE_NUMBER, FILTER_TYPE_NUMBER }, def = function ( v, a, b ) return a / b end },
["neg"] = { type = FILTER_TYPE_NUMBER, args = { FILTER_TYPE_NUMBER }, def = function ( v, a ) return -a end },
["abs"] = { type = FILTER_TYPE_NUMBER, args = { FILTER_TYPE_NUMBER }, def = function ( v, a ) return math.abs( a ) end },
["max"] = { type = FILTER_TYPE_NUMBER, args = { FILTER_TYPE_NUMBER, FILTER_TYPE_NUMBER }, def = function ( v, a, b ) return math.max( a, b ) end },
["min"] = { type = FILTER_TYPE_NUMBER, args = { FILTER_TYPE_NUMBER, FILTER_TYPE_NUMBER }, def = function ( v, a, b ) return math.min( a, b ) end },
["int"] = { type = FILTER_TYPE_NUMBER, args = { FILTER_TYPE_NUMBER }, def = function ( v, a ) return a < 0 and math.ceil( a ) or math.floor( a ) end },
["num"] = { type = FILTER_TYPE_NUMBER, args = { FILTER_TYPE_STRING }, def = function ( v, a ) return tonumber( a ) or 0 end },
["len"] = { type = FILTER_TYPE_NUMBER, args = { FILTER_TYPE_STRING }, def = function ( v, a ) return string.len( a ) end },
["lc"] = { type = FILTER_TYPE_STRING, args = { FILTER_TYPE_STRING }, def = function ( v, a ) return string.lower( a ) end },
["uc"] = { type = FILTER_TYPE_STRING, args = { FILTER_TYPE_STRING }, def = function ( v, a ) return string.upper( a ) end },
["trim"] = { type = FILTER_TYPE_STRING, args = { FILTER_TYPE_STRING, FILTER_TYPE_NUMBER }, def = function ( v, a, b ) return b > 0 and string.sub( a, 1, -b - 1 ) or string.sub( a, -b + 1 ) end },
["crop"] = { type = FILTER_TYPE_STRING, args = { FILTER_TYPE_STRING, FILTER_TYPE_NUMBER }, def = function ( v, a, b ) return b > 0 and string.sub( a, 1, b ) or string.sub( a, b, -1 ) end },
["size"] = { type = FILTER_TYPE_NUMBER, args = { FILTER_TYPE_SERIES }, def = function ( v, a ) return #a end },
["elem"] = { type = FILTER_TYPE_STRING, args = { FILTER_TYPE_SERIES, FILTER_TYPE_NUMBER }, def = function ( v, a, b ) return a[ b > 0 and b or #a + b + 1 ] or "" end },
["split"] = { type = FILTER_TYPE_SERIES, args = { FILTER_TYPE_STRING, FILTER_TYPE_STRING }, def = function ( v, a, b ) return string.split( a, b, true ) end },
["time"] = { type = FILTER_TYPE_TIMESPEC, args = { FILTER_TYPE_MOMENT }, def = function ( v, a ) return redate( a - v.epoch.value ) % 86400 end },
["date"] = { type = FILTER_TYPE_DATESPEC, args = { FILTER_TYPE_MOMENT }, def = function ( v, a ) return math.floor( redate( a - v.epoch.value ) / 86400 ) end },
["age"] = { type = FILTER_TYPE_PERIOD, args = { FILTER_TYPE_MOMENT }, def = function ( v, a ) return v.clock.value - a end },
["before"] = { type = FILTER_TYPE_MOMENT, args = { FILTER_TYPE_MOMENT, FILTER_TYPE_PERIOD }, def = function ( v, a, b ) return a - b end },
["after"] = { type = FILTER_TYPE_MOMENT, args = { FILTER_TYPE_MOMENT, FILTER_TYPE_PERIOD }, def = function ( v, a, b ) return a + b end },
["day"] = { type = FILTER_TYPE_STRING, args = { FILTER_TYPE_MOMENT }, def = function ( v, a ) return os.date( "%a", a ) end },
["at"] = { type = FILTER_TYPE_MOMENT, args = { FILTER_TYPE_STRING }, def = function ( v, a ) return localtime( a ) or 0 end },
["ip"] = { type = FILTER_TYPE_STRING, args = { FILTER_TYPE_ADDRESS }, def = function ( v, a ) return table.concat( unpack_address( a ), "." ) end },
["count"] = { type = FILTER_TYPE_NUMBER, args = { FILTER_TYPE_SERIES, FILTER_TYPE_STRING }, def = function ( v, a, b ) local t = 0; for i, v in ipairs( a ) do if v == b then t = t + 1; end; end; return t end },
["clip"] = { type = FILTER_TYPE_SERIES, args = { FILTER_TYPE_SERIES, FILTER_TYPE_NUMBER }, def = function ( v, a, b ) local x = { }; local s = b < 0 and #a + b + 1 or 0; for i = 0, math.abs( b ) do table.insert( x, a[ s + i ] ); end; return x; end },
}
local do_math = { [FILTER_TYPE_NUMBER] = true, [FILTER_TYPE_PERIOD] = true, [FILTER_TYPE_MOMENT] = true, [FILTER_TYPE_DATESPEC] = true, [FILTER_TYPE_TIMESPEC] = true }
local periods = { y = 31536000, w = 604800, d = 86400, h = 3600, m = 60, s = 1 }
local parsers = {
{ expr = "^%$([a-zA-Z0-9_]+)$", proc = function ( refs, vars )
local name = refs[ 1 ]
if not vars[ name ] or vars[ name ].value == nil then
return nil
end
return { type = vars[ name ].type, value = vars[ name ].value, const = false }
end },
{ expr = "^(.-)([a-zA-Z0-9_]+)&([A-Za-z0-9+/]*);$", proc = function ( refs, vars )
local name = refs[ 2 ]
local suffix = decode_base64( refs[ 3 ] )
local prefix = refs[ 1 ]
suffix = string.gsub( suffix, "%b()", function( str )
-- encode nested function arguments
return "&" .. encode_base64( trim( str ) ) .. ";"
end )
local args = string.split( suffix, ",", false )
if string.match( prefix, "->$" ) then
-- insert prefixed arguments
table.insert( args, 1, string.sub( prefix, 1, -3 ) )
elseif prefix ~= "" then
return nil
end
if not funcs[ name ] or #funcs[ name ].args ~= #args then
return nil
end
local params = { }
local c = true
for i, a in ipairs( args ) do
local oper, ix, rx = self.get_operand( a, vars )
if not oper or oper.type ~= funcs[ name ].args[ i ] then
return nil
end
if not oper.const then
-- propagate non-constant to parent
c = false
end
table.insert( params, oper.value )
end
return { type = funcs[ name ].type, value = funcs[ name ].def( vars, unpack( params ) ), const = c }
end },
{ expr = "^&([A-Za-z0-9+/]*);$", proc = function ( refs, vars )
local suffix = decode_base64( refs[ 1 ] )
suffix = string.gsub( suffix, "%b()", function( str )
-- encode nested function arguments
return "&" .. encode_base64( trim( str ) ) .. ";"
end )
local elems = string.split( suffix, ",", false )
local v = { }
local c = true
for i, a in ipairs( elems ) do
local oper = self.get_operand( a, vars )
if not oper or oper.type ~= FILTER_TYPE_STRING then
return nil
end
if not oper.const then
-- propagate non-constant to parent
c = false
end
table.insert( v, oper.value )
end
return { type = FILTER_TYPE_SERIES, value = v, const = c }
end },
{ expr = "^@([a-zA-Z0-9_]+%.txt)$", proc = function ( refs, vars )
local v = { }
local file = io.open( path .. "/filters/" .. refs[ 1 ], "rb" )
if not file then
return nil
end
for line in file:lines( ) do
table.insert( v, line )
end
return { type = FILTER_TYPE_SERIES, value = v, const = true }
end },
{ expr = "^/([a-zA-Z0-9+/]*),([stda]);$", proc = function( refs, vars )
local v
local phrase = minetest.decode_base64( refs[ 1 ] )
if refs[ 2 ] == "s" then
v = StringPattern( phrase, { [FILTER_TYPE_STRING] = true }, {
["["] = "",
["]"] = "",
["^"] = "%^",
["$"] = "%$",
["("] = "%(",
[")"] = "%)",
["%"] = "%%",
["-"] = "%-",
[","] = "[a-z]",
[";"] = "[A-Z]",
["="] = "[-_]",
["!"] = "[a-zA-Z0-9]",
["*"] = "[a-zA-Z0-9_-]*",
["+"] = "[a-zA-Z0-9_-]+",
["?"] = "[a-zA-Z0-9_-]",
["#"] = "%d",
["&"] = "%a",
} )
elseif refs[ 2 ] == "t" then
phrase = string.split( phrase, ":", false )
v = NumberPattern( phrase, { [FILTER_TYPE_MOMENT] = true }, { "%d?%d", "%d%d", "%d%d" }, function ( value )
-- direct translation (accounts for daylight saving time and time-zone offset)
local timespec = os.date( "*t", value )
return { timespec.hour, timespec.min, timespec.sec }
end )
elseif refs[ 2 ] == "d" then
phrase = string.split( phrase, "-", false )
v = NumberPattern( phrase, { [FILTER_TYPE_MOMENT] = true }, { "%d%d", "%d%d", "%d%d%d%d" }, function ( value )
-- direct translation (accounts for daylight saving time and time-zone offset)
local datespec = os.date( "*t", value )
return { datespec.day, datespec.month, datespec.year }
end )
elseif refs[ 2 ] == "a" then
phrase = string.split( phrase, ".", false )
v = NumberPattern( phrase, { [FILTER_TYPE_ADDRESS] = true }, { "%d?%d?%d", "%d?%d?%d", "%d?%d?%d", "%d?%d?%d" }, function ( value )
return unpack_address( value )
end )
end
if not v then
return nil
end
return { type = FILTER_TYPE_PATTERN, value = v, const = true }
end },
{ expr = "^(%d+)([ywdhms])$", proc = function ( refs, vars )
local v = tonumber( refs[ 1 ] ) * periods[ refs[ 2 ] ]
return { type = FILTER_TYPE_PERIOD, value = v, const = true }
end },
{ expr = "^([-+]%d+)([ywdhms])$", proc = function ( refs, vars )
local origin = string.byte( refs[ 1 ] ) == 45 and vars.clock.value or vars.epoch.value
local v = origin + tonumber( refs[ 1 ] ) * periods[ refs[ 2 ] ]
return { type = FILTER_TYPE_MOMENT, value = v, const = true }
end },
{ expr = "^(%d?%d):(%d%d):(%d%d)$", proc = function ( refs, vars )
local timespec = {
isdst = false, day = 1, month = 1, year = 1970, hour = tonumber( refs[ 1 ] ), min = tonumber( refs[ 2 ] ), sec = tonumber( refs[ 3 ] ),
}
-- strip date component and time-zone offset (standardize time and account for overflow too)
local v = ( os.time( timespec ) - vars.epoch.value ) % 86400
return { type = FILTER_TYPE_TIMESPEC, value = v, const = true }
end },
{ expr = "^(%d%d)%-(%d%d)%-(%d%d%d%d)$", proc = function ( refs, vars )
local datespec = {
isdst = false, day = tonumber( refs[ 1 ] ), month = tonumber( refs[ 2 ] ), year = tonumber( refs[ 3 ] ), hour = 0,
}
-- strip time component and time-zone offset (standardize time too)
local v = math.floor( ( os.time( datespec ) - vars.epoch.value ) / 86400 )
return { type = FILTER_TYPE_DATESPEC, value = v, const = true }
end },
{ expr = "^'([a-zA-Z0-9+/]*);$", proc = function ( refs, vars )
local v = decode_base64( refs[ 1 ] )
return { type = FILTER_TYPE_STRING, value = v, const = true }
end },
{ expr = "^\"([a-zA-Z0-9+/]*);$", proc = function ( refs, vars )
local v = decode_base64( refs[ 1 ] )
local c = true
v = string.gsub( v, "%$([a-zA-Z_]+)", function ( name )
-- variable interpolation is non-constant
c = false
return vars[ name ] and tostring( vars[ name ].value ) or "?"
end )
return { type = FILTER_TYPE_STRING, value = v, const = c }
end },
{ expr = "^-?%d+$", proc = function ( refs, vars )
local v = tonumber( refs[ 1 ] )
return { type = FILTER_TYPE_NUMBER, value = v, const = true }
end },
{ expr = "^-?%d*%.%d+$", proc = function ( refs, vars )
local v = tonumber( refs[ 1 ] )
return { type = FILTER_TYPE_NUMBER, value = v, const = true }
end },
{ expr = "^(%d+)%.(%d+)%.(%d+)%.(%d+)$", proc = function ( refs, vars )
local v = tonumber( refs[ 1 ] ) * 16777216 + tonumber( refs[ 2 ] ) * 65536 + tonumber( refs[ 3 ] ) * 256 + tonumber( refs[ 4 ] )
return { type = FILTER_TYPE_ADDRESS, value = v, const = true }
end },
}
---- private methods ----
function trim( str )
return string.sub( str, 2, -2 )
end
function localtime( str )
-- daylight saving time is factored in automatically
local x = { string.match( str, "^(%d+)%-(%d+)%-(%d+)T(%d+):(%d+):(%d+)Z$" ) }
return #x > 0 and os.time( { year = x[ 1 ], month = x[ 2 ], day = x[ 3 ], hour = x[ 4 ], min = x[ 5 ], sec = x[ 6 ] } ) or nil
end
function redate( ts )
-- convert to standard time (for timespec and datespec comparisons)
local x = os.date( "*t", ts )
x.isdst = false
return os.time( x )
end
---- public methods ----
self.define_func = function ( name, type, args, def )
funcs[ name ] = { type = type, args = args, def = def }
end
self.add_preset_vars = function ( vars )
vars["clock"] = { type = FILTER_TYPE_MOMENT, value = os.time( ) }
vars["epoch"] = { type = FILTER_TYPE_MOMENT, value = os.time( { year = 1970, month = 1, day = 1, hour = 0 } ) }
vars["true"] = { type = FILTER_TYPE_BOOLEAN, value = true }
vars["false"] = { type = FILTER_TYPE_BOOLEAN, value = false }
end
self.get_operand_parser = function ( token )
local match = string.match
for i, v in ipairs( parsers ) do
local refs = { match( token, v.expr ) }
if #refs > 0 then
return v.proc, refs
end
end
end
self.get_operand = function ( token, vars )
local proc, refs = self.get_operand_parser( token )
if proc then return proc( refs, vars ) end
end
self.translate = function ( input, vars )
return self.get_operand( self.tokenize( input ), vars )
end
self.get_result = function ( cond, comp, oper1, oper2 )
local type1 = oper1.type
local type2 = oper2.type
local expr
-- only allow comparisons of appropriate and equivalent datatypes
if comp == FILTER_COMP_EQ and type1 == type2 and type1 ~= FILTER_TYPE_SERIES and type1 ~= FILTER_TYPE_PATTERN then
expr = ( oper1.value == oper2.value )
elseif comp == FILTER_COMP_GT and type1 == type2 and do_math[ type2 ] then
expr = ( oper1.value > oper2.value )
elseif comp == FILTER_COMP_GTE and type1 == type2 and do_math[ type2 ] then
expr = ( oper1.value >= oper2.value )
elseif comp == FILTER_COMP_LT and type1 == type2 and do_math[ type2 ] then
expr = ( oper1.value < oper2.value )
elseif comp == FILTER_COMP_LTE and type1 == type2 and do_math[ type2 ] then
expr = ( oper1.value <= oper2.value )
elseif comp == FILTER_COMP_IS and type1 == FILTER_TYPE_STRING and type2 == FILTER_TYPE_STRING then
expr = ( string.upper( oper1.value ) == string.upper( oper2.value ) )
elseif comp == FILTER_COMP_IS and type2 == FILTER_TYPE_PATTERN then
expr = oper2.value.compare( oper1.value, type1 )
if expr == nil then return end
elseif comp == FILTER_COMP_HAS and type1 == FILTER_TYPE_SERIES and type2 == FILTER_TYPE_STRING then
local value2 = string.upper( oper2.value )
expr = false
for i, value1 in ipairs( oper1.value ) do
expr = ( string.upper( value1 ) == value2 )
if expr then break end
end
elseif comp == FILTER_COMP_HAS and type1 == FILTER_TYPE_SERIES and type2 == FILTER_TYPE_PATTERN then
local compare = oper2.value.compare
expr = false
for i, value1 in ipairs( oper1.value ) do
expr = compare( value1, FILTER_TYPE_STRING )
if expr == nil then return end
if expr then break end
end
elseif comp == FILTER_COMP_IN and type1 == FILTER_TYPE_STRING and type2 == FILTER_TYPE_SERIES then
local value1 = oper1.value
expr = false
for i, value2 in ipairs( oper2.value ) do
expr = ( value1 == value2 )
if expr then break end
end
else
return
end
if cond == FILTER_COND_FALSE then expr = not expr end
return expr
end
self.tokenize = function ( line )
-- encode string and pattern literals and function arguments to simplify parsing (order IS significant)
line = string.gsub( line, "\"(.-)\"", function ( str )
return "\"" .. encode_base64( str ) .. ";"
end )
line = string.gsub( line, "'(.-)'", function ( str )
return "'" .. encode_base64( str ) .. ";"
end )
line = string.gsub( line, "/(.-)/([stda]?)", function ( a, b )
return "/" .. encode_base64( a ) .. "," .. ( b == "" and "s" or b ) .. ";"
end )
line = string.gsub( line, "%b()", function ( str )
return "&" .. encode_base64( trim( str ) ) .. ";"
end )
return line
end
return self
end
----------------------------
-- AuthFilter subclass
----------------------------
function AuthFilter( path, name, debug )
local self = { }
local parent = GenericFilter( ) -- inherit from parent class
local src
local mode_defs = { ["pass"] = FILTER_MODE_PASS, ["fail"] = FILTER_MODE_FAIL }
local bool_defs = { ["all"] = FILTER_BOOL_AND, ["any"] = FILTER_BOOL_OR, ["one"] = FILTER_BOOL_XOR, ["now"] = FILTER_BOOL_NOW }
local cond1_defs = { ["when"] = FILTER_COND_TRUE, ["until"] = FILTER_COND_FALSE }
local cond2_defs = { ["if"] = FILTER_COND_TRUE, ["unless"] = FILTER_COND_FALSE }
local comp_defs = { ["in"] = FILTER_COMP_IN, ["eq"] = FILTER_COMP_EQ, ["gt"] = FILTER_COMP_GT, ["lt"] = FILTER_COMP_LT, ["gte"] = FILTER_COMP_GTE, ["lte"] = FILTER_COMP_LTE, ["has"] = FILTER_COMP_HAS, ["is"] = FILTER_COMP_IS }
---- private methods ----
local get_operand = parent.get_operand
local get_result = parent.get_result
local tokenize = parent.tokenize
local trace = debug or function ( msg, num )
minetest.log( "error", string.format( "%s (%s/%s, line %d)", msg, path, name, num ) )
return "The server encountered an internal error.", num
end
local evaluate = function ( rule )
-- short circuit binary logic to simplify evaluation
local res = ( rule.bool == FILTER_BOOL_AND )
local xor = 0
for i, v in ipairs( rule.expr ) do
if rule.bool == FILTER_BOOL_AND and not v then
return false
elseif rule.bool == FILTER_BOOL_OR and v then
return true
elseif rule.bool == FILTER_BOOL_XOR and v then
xor = xor + 1
end
end
if xor == 1 then return true end
return res
end
---- public methods ----
self.add_preset_vars = parent.add_preset_vars
self.refresh = function ( )
local file = io.open( path .. "/" .. name, "r" )
if not file then
file = io.open( path .. "/" .. name, "w+")
if not file then
error( "The specified ruleset file does not exist." )
end
file:write("pass now")
file:close( file )
file = io.open( path .. "/" .. name, "r" )
end
src = { }
for line in file:lines( ) do
-- skip comments (lines beginning with hash character) and blank lines
table.insert( src, string.byte( line ) ~= 35 and tokenize( line ) or "" )
end
file:close( file )
end
self.process = function( vars, is_local )
local rule
local note = "Access denied."
if is_local then
self.add_preset_vars( vars )
end
for num, line in ipairs( src ) do
local stmt = string.split( line, " ", false )
if #stmt == 0 then
-- skip no-op statements
elseif stmt[ 1 ] == "continue" then
if not rule then return trace( "Unexpected 'continue' statement in ruleset", num ) end
if #stmt ~= 1 then return trace( "Invalid 'continue' statement in ruleset", num ) end
if evaluate( rule ) then
return ( rule.mode == FILTER_MODE_FAIL and note or nil ), num
end
rule = nil
elseif stmt[ 1 ] == "try" then
if rule then return trace( "Missing 'continue' statement in ruleset", num ) end
if #stmt ~= 2 then return trace( "Invalid 'try' statement in ruleset", num ) end
local oper = get_operand( stmt[ 2 ], vars )
if not oper or oper.type ~= FILTER_TYPE_STRING then
return trace( "Unrecognized operand in ruleset", num )
end
note = oper.value
elseif stmt[ 1 ] == "pass" or stmt[ 1 ] == "fail" then
if rule then return trace( "Missing 'continue' statement in ruleset", num ) end
if #stmt ~= 2 then return trace( "Invalid 'pass' or 'fail' statement in ruleset", num ) end
local mode = mode_defs[ stmt[ 1 ] ]
local bool = bool_defs[ stmt[ 2 ] ]
if not mode or not bool then
return trace( "Unrecognized keywords in ruleset", num )
end
if bool == FILTER_BOOL_NOW then
return ( mode == FILTER_MODE_FAIL and note or nil ), num
end
rule = { mode = mode, bool = bool, expr = { } }
elseif stmt[ 1 ] == "when" or stmt[ 1 ] == "until" then
if rule then return trace( "Unexpected 'when' or 'until' statement in ruleset", num ) end
if #stmt ~= 5 then return trace( "Invalid 'when' or 'until' statement in ruleset", num ) end
local cond = cond1_defs[ stmt[ 1 ] ]
local comp = comp_defs[ stmt[ 3 ] ]
local mode = mode_defs[ stmt[ 5 ] ]
if not cond or not comp then
return trace( "Unrecognized keywords in ruleset", num )
end
local oper1 = get_operand( stmt[ 2 ], vars )
local oper2 = get_operand( stmt[ 4 ], vars )
if not oper1 or not oper2 then
return trace( "Unrecognized operands in ruleset", num )
end
local expr = get_result( cond, comp, oper1, oper2 )
if expr == nil then
return trace( "Mismatched operands in ruleset", num )
elseif expr then
return ( mode == FILTER_MODE_FAIL and note or nil ), num
end
elseif stmt[ 1 ] == "if" or stmt[ 1 ] == "unless" then
if not rule then return trace( "Unexpected 'if' or 'unless' statement in ruleset", num ) end
if #stmt ~= 4 then return trace( "Invalid 'if' or 'unless' statement in ruleset", num ) end
local cond = cond2_defs[ stmt[ 1 ] ]
local comp = comp_defs[ stmt[ 3 ] ]
if not cond or not comp then
return trace( "Unrecognized keywords in ruleset", num )
end
local oper1 = get_operand( stmt[ 2 ], vars )
local oper2 = get_operand( stmt[ 4 ], vars )
if not oper1 or not oper2 then
return trace( "Unrecognized operands in ruleset", num )
end
local expr = get_result( cond, comp, oper1, oper2 )
if expr == nil then
return trace( "Mismatched operands in ruleset", num )
end
table.insert( rule.expr, expr )
else
return trace( "Invalid statement in ruleset", num )
end
end
return trace( "Unexpected end-of-file in ruleset", 0 )
end
self.refresh( )
return self
end
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