mirror of
https://gerrit.wikimedia.org/r/mediawiki/extensions/AbuseFilter.git
synced 2024-12-01 09:06:22 +00:00
510 lines
13 KiB
C++
510 lines
13 KiB
C++
/*
|
|
* Copyright (c) 2008 Andrew Garrett.
|
|
* Copyright (c) 2008 River Tarnell <river@wikimedia.org>
|
|
* Derived from public domain code contributed by Victor Vasiliev.
|
|
*
|
|
* Permission is granted to anyone to use this software for any purpose,
|
|
* including commercial applications, and to alter it and redistribute it
|
|
* freely. This software is provided 'as-is', without any express or
|
|
* implied warranty.
|
|
*/
|
|
|
|
#ifndef EXPRESSOR_H
|
|
#define EXPRESSOR_H
|
|
|
|
#include <string>
|
|
#include <vector>
|
|
#include <stdexcept>
|
|
#include <iostream>
|
|
|
|
#include <boost/noncopyable.hpp>
|
|
#include <boost/function.hpp>
|
|
#include <boost/spirit/core.hpp>
|
|
#include <boost/spirit/utility/confix.hpp>
|
|
#include <boost/spirit/utility/chset.hpp>
|
|
#include <boost/spirit/utility/loops.hpp>
|
|
#include <boost/spirit/tree/ast.hpp>
|
|
#include <boost/spirit/tree/tree_to_xml.hpp>
|
|
#include <boost/spirit/symbols.hpp>
|
|
#include <boost/spirit/utility/escape_char.hpp>
|
|
#include <boost/function.hpp>
|
|
#include <boost/noncopyable.hpp>
|
|
#include <boost/format.hpp>
|
|
#include <boost/regex/icu.hpp>
|
|
|
|
#include <unicode/uchar.h>
|
|
|
|
#include "aftypes.h"
|
|
#include "afstring.h"
|
|
#include "affunctions.h"
|
|
#include "fray.h"
|
|
#include "ast.h"
|
|
#include "parserdefs.h"
|
|
|
|
namespace afp {
|
|
|
|
template<typename T> struct parser_grammar;
|
|
|
|
template<typename charT>
|
|
struct basic_expressor : boost::noncopyable {
|
|
typedef boost::function<basic_datum<charT> (std::vector<basic_datum<charT> >)> func_t;
|
|
|
|
basic_expressor();
|
|
~basic_expressor();
|
|
|
|
basic_datum<charT> evaluate(basic_fray<charT> const &expr) const;
|
|
void print_xml(std::ostream &strm, basic_fray<charT> const &expr) const;
|
|
|
|
void add_variable(basic_fray<charT> const &name, basic_datum<charT> const &value);
|
|
void add_function(basic_fray<charT> const &name, func_t value);
|
|
|
|
void clear();
|
|
void clear_functions();
|
|
void clear_variables();
|
|
|
|
private:
|
|
parser_grammar<charT> *grammar_;
|
|
};
|
|
|
|
typedef basic_expressor<char> expressor;
|
|
typedef basic_expressor<UChar32> u32expressor;
|
|
|
|
using namespace boost::spirit;
|
|
|
|
/*
|
|
* ABUSEFILTER EXPRESSION PARSER
|
|
* =============================
|
|
*
|
|
* This is the basic expression parser. It doesn't contain any AF logic
|
|
* itself, but rather presents an interface for the user to add custom
|
|
* functions and variables.
|
|
*
|
|
* The interface to the parser is the 'expressor' class. Use it like this:
|
|
*
|
|
* expressor e;
|
|
* e.add_variable("ONE", 1);
|
|
* e.add_function("f", myfunc);
|
|
* e.evaluate("ONE + 2"); -- returns 3
|
|
*
|
|
* Custom functions should have the following prototype:
|
|
*
|
|
* afp::basic_datum<charT> (std::vector<afp::basic_datum<charT>) const &args);
|
|
*
|
|
* Functions must return a value; they cannot be void. The arguments passed to
|
|
* the function are stored in the 'args' array in left-to-right order.
|
|
*
|
|
* The parser implements a C-like grammar with some differences. The following
|
|
* operators are available:
|
|
*
|
|
* a & b true if a and b are both true
|
|
* a | b true if either a or b is true
|
|
* a ^ b true if either a or b is true, but not if both are true
|
|
* a + b arithmetic
|
|
* a - b
|
|
* a * b
|
|
* a / b
|
|
* a % b
|
|
* a ** b power-of (a^b)
|
|
* a in b true if the string "b" contains the substring "a"
|
|
* a contains b true if b contains the string a
|
|
* a like b true if a matches the Unix glob b
|
|
* a matches b '' ''
|
|
* a rlike b true if a matches the Perl regex b
|
|
* a regex b '' ''
|
|
* !a true if a is false
|
|
* (a) same value as a
|
|
* a ? b : c if a is true, returns the value of b, otherwise c
|
|
* a == b comparison operators
|
|
* a != b
|
|
* a < b
|
|
* a <= b
|
|
* a > b
|
|
* a >= b
|
|
* a === b returns true if a==b and both are the same type
|
|
* a !== b return true if a != b or they are different types
|
|
*
|
|
* The parser uses afp::datum for its variables. This means it supports
|
|
* strings, ints and floats, with automatic conversion between types.
|
|
*
|
|
* String constants are C-style. The standard C escapes \a \b \f \t \r \n \v are
|
|
* supported. \xHH encodes a 1-byte Unicode character, \uHHHH encodes a 2-byte
|
|
* Unicode characters, and \UHHHHHHHH encodes a 4-byte Unicode character.
|
|
*
|
|
* Numeric constants can be integers (e.g. 1), or floating pointers (e.g.
|
|
* 1., .1, 1.2).
|
|
*
|
|
* Function calls are f(arg1, arg2, ...).
|
|
*/
|
|
|
|
/*
|
|
* The grammar itself.
|
|
*/
|
|
template<typename charT>
|
|
struct parser_grammar : public grammar<parser_grammar<charT> >
|
|
{
|
|
/* User-defined variables. */
|
|
symbols<basic_datum<charT>, charT > variables;
|
|
|
|
void add_variable(basic_fray<charT> const &name, basic_datum<charT> const &value) {
|
|
variables.add(name.c_str(), value);
|
|
}
|
|
|
|
/* User-defined functions. */
|
|
symbols<boost::function<basic_datum<charT> (std::vector<basic_datum<charT> >)>, charT > functions;
|
|
|
|
void add_function(
|
|
basic_fray<charT> const &name,
|
|
boost::function<basic_datum<charT> (std::vector<basic_datum<charT> >)> func) {
|
|
functions.add(name.c_str(), func);
|
|
}
|
|
|
|
symbols<int, charT> eq_opers, ord_opers, plus_opers, mult_opers, in_opers, bool_opers;
|
|
|
|
parser_grammar() {
|
|
eq_opers.add("=", 0);
|
|
eq_opers.add("==", 0);
|
|
eq_opers.add("===", 0);
|
|
eq_opers.add("!=", 0);
|
|
eq_opers.add("!==", 0);
|
|
eq_opers.add("/=", 0);
|
|
ord_opers.add("<", 0);
|
|
ord_opers.add("<=", 0);
|
|
ord_opers.add(">", 0);
|
|
ord_opers.add(">=", 0);
|
|
plus_opers.add("+", 0);
|
|
plus_opers.add("-", 0);
|
|
mult_opers.add("*", 0);
|
|
mult_opers.add("/", 0);
|
|
mult_opers.add("%", 0);
|
|
bool_opers.add("&", 0);
|
|
bool_opers.add("|", 0);
|
|
bool_opers.add("^", 0);
|
|
in_opers.add("in", 0);
|
|
in_opers.add("contains", 0);
|
|
in_opers.add("matches", 0);
|
|
in_opers.add("like", 0);
|
|
in_opers.add("rlike", 0);
|
|
in_opers.add("regex", 0);
|
|
}
|
|
|
|
template<typename ScannerT>
|
|
struct definition
|
|
{
|
|
parser_grammar const &self_;
|
|
|
|
definition(parser_grammar const &self)
|
|
: self_(self)
|
|
{
|
|
/*
|
|
* A literal value. Either a string, a floating
|
|
* pointer number or an integer.
|
|
*/
|
|
value =
|
|
#if 0
|
|
strict_real_p
|
|
| as_lower_d[ leaf_node_d[
|
|
oct_p >> 'o'
|
|
| hex_p >> 'x'
|
|
| bin_p >> 'b'
|
|
| int_p
|
|
] ]
|
|
#endif
|
|
reduced_node_d[ lexeme_d[
|
|
(+chset<>("0-9") >> '.' >> +chset<>("0-9"))
|
|
| ( '.' >> +chset<>("0-9"))
|
|
| (+chset<>("0-9") >> '.' )
|
|
] ]
|
|
| as_lower_d[ leaf_node_d[
|
|
+chset<>("0-7") >> 'o'
|
|
| +chset<>("0-9a-f") >> 'x'
|
|
| +chset<>("0-1") >> 'b'
|
|
| +chset<>("0-9")
|
|
] ]
|
|
| string
|
|
;
|
|
|
|
hexchar = chset<>("a-fA-F0-9")
|
|
;
|
|
|
|
octchar = chset<>("0-7")
|
|
;
|
|
|
|
c_string_char =
|
|
"\\x" >> hexchar >> hexchar
|
|
| "\\u" >> repeat_p(4)[hexchar]
|
|
| "\\U" >> repeat_p(8)[hexchar]
|
|
| "\\o" >> octchar >> octchar >> octchar
|
|
| "\\" >> anychar_p - (ch_p('x') | 'u' | 'o')
|
|
| anychar_p - (ch_p('"') | '\\')
|
|
;
|
|
|
|
/*
|
|
* config_p can't be used here, because it will rewrite
|
|
* *(c_escape_ch_p[x]) into (*c_escape_ch_p)[x]
|
|
*/
|
|
string = inner_node_d[
|
|
'"'
|
|
>> leaf_node_d[ *(c_string_char) ]
|
|
>> '"'
|
|
]
|
|
;
|
|
|
|
/*
|
|
* A variable. If the variable is found in the
|
|
* user-supplied variable list, we use that.
|
|
* Otherwise, unknown variables (containing uppercase
|
|
* letters and underscore only) are returned as the
|
|
* empty string.
|
|
*/
|
|
variable = reduced_node_d[ +(upper_p | '_') ]
|
|
;
|
|
|
|
/*
|
|
* A function call: func([arg[, arg...]]).
|
|
*/
|
|
function =
|
|
(
|
|
root_node_d[ reduced_node_d[
|
|
+(lower_p | '_')
|
|
] ]
|
|
>> inner_node_d[
|
|
'('
|
|
>> ( tern_expr % discard_node_d[ch_p(',')] )
|
|
>> ')'
|
|
]
|
|
)
|
|
;
|
|
|
|
/*
|
|
* A basic atomic value. Either a variable, function
|
|
* or literal, or a negated expression !a, or a
|
|
* parenthesised expression (a).
|
|
*/
|
|
basic =
|
|
value
|
|
| variable
|
|
| function
|
|
| inner_node_d[ '(' >> tern_expr >> ')' ]
|
|
| root_node_d[ch_p('!')] >> tern_expr
|
|
| root_node_d[ch_p('+')] >> tern_expr
|
|
| root_node_d[ch_p('-')] >> tern_expr
|
|
;
|
|
|
|
/*
|
|
* "a in b" operator
|
|
*/
|
|
in_expr =
|
|
basic
|
|
>> *( root_node_d[ self.in_opers ] >> basic )
|
|
;
|
|
|
|
/*
|
|
* power-of. This is right-associative.
|
|
*/
|
|
pow_expr =
|
|
in_expr
|
|
>> !( root_node_d[ str_p("**") ] >> pow_expr )
|
|
;
|
|
|
|
/*
|
|
* Multiplication and operators with the same
|
|
* precedence.
|
|
*/
|
|
mult_expr =
|
|
pow_expr
|
|
>> *( root_node_d[ self.mult_opers ] >> pow_expr )
|
|
;
|
|
|
|
/*
|
|
* Additional and operators with the same precedence.
|
|
*/
|
|
plus_expr =
|
|
mult_expr
|
|
>> *( root_node_d[ self.plus_opers ] >> mult_expr )
|
|
;
|
|
|
|
/*
|
|
* Ordinal comparisons and operators with the same
|
|
* precedence.
|
|
*/
|
|
ord_expr =
|
|
plus_expr
|
|
>> *( root_node_d[ self.ord_opers ] >> plus_expr )
|
|
;
|
|
|
|
/*
|
|
* Equality comparisons.
|
|
*/
|
|
eq_expr =
|
|
ord_expr
|
|
>> *( root_node_d[ self.eq_opers ] >> ord_expr )
|
|
;
|
|
|
|
/*
|
|
* Boolean expressions.
|
|
*/
|
|
bool_expr =
|
|
eq_expr
|
|
>> *( root_node_d[ self.bool_opers ] >> eq_expr )
|
|
;
|
|
|
|
/*
|
|
* The ternary operator. Notice this is
|
|
* right-associative: a ? b ? c : d : e
|
|
* is supported.
|
|
*/
|
|
tern_expr =
|
|
bool_expr
|
|
>> !(
|
|
root_node_d[ch_p('?')] >> tern_expr
|
|
>> discard_node_d[ch_p(':')] >> tern_expr
|
|
)
|
|
;
|
|
}
|
|
|
|
rule<ScannerT, parser_context<>, parser_tag<pid_tern_expr> >
|
|
const &start() const {
|
|
return tern_expr;
|
|
}
|
|
|
|
rule<ScannerT> c_string_char, hexchar, octchar;
|
|
rule<ScannerT, parser_context<>, parser_tag<pid_value> > value;
|
|
rule<ScannerT, parser_context<>, parser_tag<pid_variable> > variable;
|
|
rule<ScannerT, parser_context<>, parser_tag<pid_basic> > basic;
|
|
rule<ScannerT, parser_context<>, parser_tag<pid_bool_expr> > bool_expr;
|
|
rule<ScannerT, parser_context<>, parser_tag<pid_ord_expr> > ord_expr;
|
|
rule<ScannerT, parser_context<>, parser_tag<pid_eq_expr> > eq_expr;
|
|
rule<ScannerT, parser_context<>, parser_tag<pid_pow_expr> > pow_expr;
|
|
rule<ScannerT, parser_context<>, parser_tag<pid_mult_expr> > mult_expr;
|
|
rule<ScannerT, parser_context<>, parser_tag<pid_plus_expr> > plus_expr;
|
|
rule<ScannerT, parser_context<>, parser_tag<pid_in_expr> > in_expr;
|
|
|
|
rule<ScannerT, parser_context<>, parser_tag<pid_function> > function;
|
|
rule<ScannerT, parser_context<>, parser_tag<pid_tern_expr> > tern_expr;
|
|
rule<ScannerT, parser_context<>, parser_tag<pid_string> > string;
|
|
};
|
|
};
|
|
|
|
template<typename charT>
|
|
basic_expressor<charT>::basic_expressor()
|
|
: grammar_(new parser_grammar<charT>)
|
|
{
|
|
/*
|
|
* We provide a couple of standard variables everyone wants.
|
|
*/
|
|
add_variable(make_astring<charT>("true"), afp::basic_datum<charT>::from_int(true));
|
|
add_variable(make_astring<charT>("false"), afp::basic_datum<charT>::from_int(false));
|
|
|
|
/*
|
|
* The cast functions.
|
|
*/
|
|
add_function(make_astring<charT>("int"), &f_int<charT>);
|
|
add_function(make_astring<charT>("string"), &f_string<charT>);
|
|
add_function(make_astring<charT>("float"), &f_float<charT>);
|
|
}
|
|
|
|
template<typename charT>
|
|
basic_expressor<charT>::~basic_expressor()
|
|
{
|
|
delete grammar_;
|
|
}
|
|
|
|
/*
|
|
* The user interface to evaluate an expression. It returns the result, or
|
|
* throws an exception if an error occurs.
|
|
*/
|
|
template<typename charT>
|
|
basic_datum<charT>
|
|
basic_expressor<charT>::evaluate(basic_fray<charT> const &filter) const
|
|
{
|
|
using namespace boost::spirit;
|
|
|
|
typedef typename basic_fray<charT>::const_iterator iterator_t;
|
|
|
|
basic_datum<charT> ret;
|
|
|
|
tree_parse_info<iterator_t> info = ast_parse(filter.begin(), filter.end(), *grammar_ >> end_p,
|
|
chset<>("\r\n\t ") | comment_p("/*", "*/"));
|
|
|
|
if (info.full) {
|
|
ast_evaluator<charT, typename tree_match<iterator_t>::tree_iterator> ae(*grammar_);
|
|
return ae.tree_eval(info.trees.begin());
|
|
} else {
|
|
throw parse_error("parsing failed");
|
|
}
|
|
}
|
|
|
|
template<typename charT>
|
|
void
|
|
basic_expressor<charT>::print_xml(std::ostream &strm, basic_fray<charT> const &filter) const
|
|
{
|
|
using namespace boost::spirit;
|
|
|
|
typedef typename basic_fray<charT>::const_iterator iterator_t;
|
|
|
|
tree_parse_info<iterator_t> info = ast_parse(filter.begin(), filter.end(), *grammar_ >> end_p,
|
|
+chset<>("\n\t ") | comment_p("/*", "*/"));
|
|
|
|
if (info.full) {
|
|
std::map<parser_id, std::string> rule_names;
|
|
rule_names[pid_value] = "value";
|
|
rule_names[pid_variable] = "variable";
|
|
rule_names[pid_basic] = "basic";
|
|
rule_names[pid_bool_expr] = "bool_expr";
|
|
rule_names[pid_ord_expr] = "ord_expr";
|
|
rule_names[pid_eq_expr] = "eq_expr";
|
|
rule_names[pid_pow_expr] = "pow_expr";
|
|
rule_names[pid_mult_expr] = "mult_expr";
|
|
rule_names[pid_plus_expr] = "plus_expr";
|
|
rule_names[pid_in_expr] = "in_expr";
|
|
rule_names[pid_function] = "function";
|
|
rule_names[pid_tern_expr] = "tern_expr";
|
|
rule_names[pid_string] = "string";
|
|
tree_to_xml(strm, info.trees, "", rule_names);
|
|
} else {
|
|
throw parse_error("parsing failed");
|
|
}
|
|
}
|
|
|
|
template<typename charT>
|
|
void
|
|
basic_expressor<charT>::clear()
|
|
{
|
|
clear_variables();
|
|
clear_functions();
|
|
}
|
|
|
|
template<typename charT>
|
|
void
|
|
basic_expressor<charT>::clear_variables()
|
|
{
|
|
symbols<basic_datum<charT>, charT > variables;
|
|
grammar_->variables = variables;
|
|
}
|
|
|
|
template<typename charT>
|
|
void
|
|
basic_expressor<charT>::clear_functions()
|
|
{
|
|
symbols<boost::function<basic_datum<charT> (std::vector<basic_datum<charT> >)>, charT > functions;
|
|
grammar_->functions = functions;
|
|
}
|
|
|
|
template<typename charT>
|
|
void
|
|
basic_expressor<charT>::add_variable(basic_fray<charT> const &name, basic_datum<charT> const &value)
|
|
{
|
|
grammar_->add_variable(name, value);
|
|
}
|
|
|
|
template<typename charT>
|
|
void
|
|
basic_expressor<charT>::add_function(basic_fray<charT> const &name, func_t value)
|
|
{
|
|
grammar_->add_function(name, value);
|
|
}
|
|
|
|
} // namespace afp
|
|
|
|
#endif /* !EXPRESSOR_H */
|