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ircd::rfc3986: Refactor uri encoder/decoder related; reorg.

ircd::rfc3986::encoder: Proper unreserved character selection.

ircd::rfc3986::decoder: Split into safe and unsafe grammars and interface.

ircd::rfc3986::decoder: Use expectation_failure template exception.
This commit is contained in:
Jason Volk 2020-03-28 18:33:34 -07:00
parent 1a2334e6a8
commit af9629324e
2 changed files with 150 additions and 92 deletions

View file

@ -30,6 +30,7 @@ namespace ircd::rfc3986
string_view encode(const mutable_buffer &, const string_view &url);
string_view encode(const mutable_buffer &, const json::members &);
string_view decode(const mutable_buffer &, const string_view &url);
const_buffer decode_unsafe(const mutable_buffer &, const string_view &url);
// extractor suite
uint16_t port(const string_view &remote); // get portnum from valid remote

View file

@ -23,60 +23,6 @@ __attribute__((visibility("hidden")))
using namespace ircd::spirit;
}}}
struct ircd::rfc3986::encoder
:karma::grammar<char *, const string_view>
{
[[noreturn]] void throw_illegal()
{
throw encoding_error
{
"Generator Protection: urlencode"
};
}
karma::rule<char *, const string_view> url_encoding
{
*(karma::char_("A-Za-z0-9") | (karma::lit('%') << karma::hex))
,"url encoding"
};
encoder(): encoder::base_type{url_encoding} {}
}
const ircd::rfc3986::encoder;
struct ircd::rfc3986::decoder
:qi::grammar<const char *, mutable_buffer>
{
template<class R = unused_type, class... S> using rule = qi::rule<const char *, R, S...>;
rule<> url_illegal
{
char_(0x00, 0x1f)
,"url illegal"
};
rule<char()> url_encodable
{
char_("A-Za-z0-9")
,"url encodable character"
};
rule<char()> urlencoded_character
{
'%' > qi::uint_parser<char, 16, 2, 2>{}
,"urlencoded character"
};
rule<mutable_buffer> url_decode
{
*((char_ - '%') | urlencoded_character)
,"urldecode"
};
decoder(): decoder::base_type { url_decode } {}
}
const ircd::rfc3986::decoder;
decltype(ircd::rfc3986::parser::sub_delims)
ircd::rfc3986::parser::sub_delims
{
@ -472,9 +418,149 @@ ircd::rfc3986::uri::uri(const string_view &input)
}
//
// general interface
// uri decoding
//
struct ircd::rfc3986::decoder
:qi::grammar<const char *, mutable_buffer>
{
template<class R = unused_type,
class... S>
using rule = qi::rule<const char *, R, S...>;
[[noreturn]] static void throw_unsafe()
{
throw decoding_error
{
"Unsafe characters in decoding."
};
}
const rule<char()> decode_char
{
lit('%') > qi::uint_parser<char, 16, 2, 2>{}
,"url decodable character"
};
const rule<char()> unreserved_char
{
// unreserved characters and !$+*'(),
char_("A-Za-z0-9._~!$+*'(),-")
,"url unreserved characters"
};
const rule<mutable_buffer> decode_unsafe
{
*((char_ - '%') | decode_char)
,"url unsafe decode"
};
rule<mutable_buffer> decode_safe
{
rule<mutable_buffer>{}
,"url safe decode"
};
decoder()
:decoder::base_type{decode_safe}
{
//TODO: XXX this never reports failure to throw; it just stops parsing
decode_safe %= *(unreserved_char | decode_char[_pass = (local::_1 > 0x1F)]);
}
}
const ircd::rfc3986::decoder;
ircd::const_buffer
ircd::rfc3986::decode_unsafe(const mutable_buffer &buf,
const string_view &url)
try
{
const char *start(url.data()), *const stop
{
start + std::min(size(url), size(buf))
};
mutable_buffer mb
{
data(buf), size_t(0)
};
const bool ok
{
qi::parse(start, stop, decoder.decode_unsafe, mb)
};
assert(size(mb) <= size(url));
return string_view
{
data(mb), size(mb)
};
}
catch(const qi::expectation_failure<const char *> &e)
{
throw expectation_failure<decoding_error>{e};
}
ircd::string_view
ircd::rfc3986::decode(const mutable_buffer &buf,
const string_view &url)
try
{
const char *start(url.data()), *const stop
{
start + std::min(size(url), size(buf))
};
mutable_buffer mb
{
data(buf), size_t(0)
};
const bool ok
{
qi::parse(start, stop, decoder.decode_safe, mb)
};
assert(size(mb) <= size(url));
return string_view
{
data(mb), size(mb)
};
}
catch(const qi::expectation_failure<const char *> &e)
{
throw expectation_failure<decoding_error>{e};
}
//
// uri encoding
//
struct ircd::rfc3986::encoder
:karma::grammar<char *, const string_view>
{
template<class R = unused_type,
class... S>
using rule = karma::rule<char *, R, S...>;
const rule<char()> unreserved
{
char_("A-Za-z0-9._~-")
,"url unencoded"
};
const rule<const string_view> encode
{
*(unreserved | (lit('%') << karma::right_align(2, '0')[karma::hex]))
,"url encode"
};
encoder()
:encoder::base_type{encode}
{}
}
const ircd::rfc3986::encoder;
ircd::string_view
ircd::rfc3986::encode(const mutable_buffer &out,
const json::members &members)
@ -514,49 +600,20 @@ ircd::rfc3986::encode(const mutable_buffer &buf,
const string_view &url)
{
char *out(data(buf));
karma::generate(out, maxwidth(size(buf))[encoder], url);
const bool ok
{
karma::generate(out, maxwidth(size(buf))[encoder], url)
};
return string_view
{
data(buf), size_t(std::distance(data(buf), out))
};
}
ircd::string_view
ircd::rfc3986::decode(const mutable_buffer &buf,
const string_view &url)
try
{
const char *start(url.data()), *const stop
{
start + std::min(size(url), size(buf))
};
mutable_buffer mb
{
data(buf), size_t(0)
};
qi::parse(start, stop, eps > decoder, mb);
return string_view
{
data(mb), size(mb)
};
}
catch(const qi::expectation_failure<const char *> &e)
{
const auto rule
{
ircd::string(e.what_)
};
throw decoding_error
{
"I require a valid urlencoded %s. You sent %zu invalid chars starting with `%s'.",
between(rule, "<", ">"),
size_t(e.last - e.first),
string_view{e.first, e.last}
};
}
//
// general interface
//
ircd::string_view
ircd::rfc3986::host(const string_view &str)