Files
boost_beast/include/beast/websocket/detail/stream_base.hpp
T
Vinnie Falco f7a0885d17 Remove websocket::keep_alive option (API Change):
fix #332

This removes the keep_alive option from the WebSocket stream.
Callers who wish to control the behavior of the Connection
header may do so in the decorator and completion handlers
for the handshake and accept functions.
2017-07-20 08:12:16 -07:00

561 lines
15 KiB
C++

//
// Copyright (c) 2013-2017 Vinnie Falco (vinnie dot falco at gmail dot com)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
#ifndef BEAST_WEBSOCKET_DETAIL_STREAM_BASE_HPP
#define BEAST_WEBSOCKET_DETAIL_STREAM_BASE_HPP
#include <beast/websocket/error.hpp>
#include <beast/websocket/option.hpp>
#include <beast/websocket/rfc6455.hpp>
#include <beast/websocket/detail/frame.hpp>
#include <beast/websocket/detail/mask.hpp>
#include <beast/websocket/detail/pausation.hpp>
#include <beast/websocket/detail/pmd_extension.hpp>
#include <beast/websocket/detail/utf8_checker.hpp>
#include <beast/http/message.hpp>
#include <beast/http/string_body.hpp>
#include <beast/zlib/deflate_stream.hpp>
#include <beast/zlib/inflate_stream.hpp>
#include <boost/asio/error.hpp>
#include <boost/assert.hpp>
#include <cstdint>
#include <memory>
namespace beast {
namespace websocket {
namespace detail {
/// Identifies the role of a WebSockets stream.
enum class role_type
{
/// Stream is operating as a client.
client,
/// Stream is operating as a server.
server
};
//------------------------------------------------------------------------------
struct stream_base
{
protected:
friend class frame_test;
struct op {};
detail::maskgen maskgen_; // source of mask keys
std::size_t rd_msg_max_ =
16 * 1024 * 1024; // max message size
bool wr_autofrag_ = true; // auto fragment
std::size_t wr_buf_size_ = 4096; // write buffer size
std::size_t rd_buf_size_ = 4096; // read buffer size
opcode wr_opcode_ = opcode::text; // outgoing message type
ping_cb ping_cb_; // ping callback
role_type role_; // server or client
bool failed_; // the connection failed
bool wr_close_; // sent close frame
op* wr_block_; // op currenly writing
ping_data* ping_data_; // where to put the payload
pausation rd_op_; // parked read op
pausation wr_op_; // parked write op
pausation ping_op_; // parked ping op
close_reason cr_; // set from received close frame
// State information for the message being received
//
struct rd_t
{
// opcode of current message being read
opcode op;
// `true` if the next frame is a continuation.
bool cont;
// Checks that test messages are valid utf8
detail::utf8_checker utf8;
// Size of the current message so far.
std::uint64_t size;
// Size of the read buffer.
// This gets set to the read buffer size option at the
// beginning of sending a message, so that the option can be
// changed mid-send without affecting the current message.
std::size_t buf_size;
// The read buffer. Used for compression and masking.
std::unique_ptr<std::uint8_t[]> buf;
};
rd_t rd_;
// State information for the message being sent
//
struct wr_t
{
// `true` if next frame is a continuation,
// `false` if next frame starts a new message
bool cont;
// `true` if this message should be auto-fragmented
// This gets set to the auto-fragment option at the beginning
// of sending a message, so that the option can be changed
// mid-send without affecting the current message.
bool autofrag;
// `true` if this message should be compressed.
// This gets set to the compress option at the beginning of
// of sending a message, so that the option can be changed
// mid-send without affecting the current message.
bool compress;
// Size of the write buffer.
// This gets set to the write buffer size option at the
// beginning of sending a message, so that the option can be
// changed mid-send without affecting the current message.
std::size_t buf_size;
// The write buffer. Used for compression and masking.
// The buffer is allocated or reallocated at the beginning of
// sending a message.
std::unique_ptr<std::uint8_t[]> buf;
};
wr_t wr_;
// State information for the permessage-deflate extension
struct pmd_t
{
// `true` if current read message is compressed
bool rd_set;
zlib::deflate_stream zo;
zlib::inflate_stream zi;
};
// If not engaged, then permessage-deflate is not
// enabled for the currently active session.
std::unique_ptr<pmd_t> pmd_;
// Local options for permessage-deflate
permessage_deflate pmd_opts_;
// Offer for clients, negotiated result for servers
pmd_offer pmd_config_;
stream_base() = default;
stream_base(stream_base&&) = default;
stream_base(stream_base const&) = delete;
stream_base& operator=(stream_base&&) = default;
stream_base& operator=(stream_base const&) = delete;
template<class = void>
void
open(role_type role);
template<class = void>
void
close();
template<class DynamicBuffer>
std::size_t
read_fh1(detail::frame_header& fh,
DynamicBuffer& db, close_code& code);
template<class DynamicBuffer>
void
read_fh2(detail::frame_header& fh,
DynamicBuffer& db, close_code& code);
// Called before receiving the first frame of each message
template<class = void>
void
rd_begin();
// Called before sending the first frame of each message
//
template<class = void>
void
wr_begin();
template<class DynamicBuffer>
void
write_close(DynamicBuffer& db, close_reason const& rc);
template<class DynamicBuffer>
void
write_ping(DynamicBuffer& db, opcode op, ping_data const& data);
};
template<class>
void
stream_base::
open(role_type role)
{
// VFALCO TODO analyze and remove dupe code in reset()
role_ = role;
failed_ = false;
rd_.cont = false;
wr_close_ = false;
wr_block_ = nullptr; // should be nullptr on close anyway
ping_data_ = nullptr; // should be nullptr on close anyway
wr_.cont = false;
wr_.buf_size = 0;
if(((role_ == role_type::client && pmd_opts_.client_enable) ||
(role_ == role_type::server && pmd_opts_.server_enable)) &&
pmd_config_.accept)
{
pmd_normalize(pmd_config_);
pmd_.reset(new pmd_t);
if(role_ == role_type::client)
{
pmd_->zi.reset(
pmd_config_.server_max_window_bits);
pmd_->zo.reset(
pmd_opts_.compLevel,
pmd_config_.client_max_window_bits,
pmd_opts_.memLevel,
zlib::Strategy::normal);
}
else
{
pmd_->zi.reset(
pmd_config_.client_max_window_bits);
pmd_->zo.reset(
pmd_opts_.compLevel,
pmd_config_.server_max_window_bits,
pmd_opts_.memLevel,
zlib::Strategy::normal);
}
}
}
template<class>
void
stream_base::
close()
{
rd_.buf.reset();
wr_.buf.reset();
pmd_.reset();
}
// Read fixed frame header from buffer
// Requires at least 2 bytes
//
template<class DynamicBuffer>
std::size_t
stream_base::
read_fh1(detail::frame_header& fh,
DynamicBuffer& db, close_code& code)
{
using boost::asio::buffer;
using boost::asio::buffer_copy;
using boost::asio::buffer_size;
auto const err =
[&](close_code cv)
{
code = cv;
return 0;
};
std::uint8_t b[2];
BOOST_ASSERT(buffer_size(db.data()) >= sizeof(b));
db.consume(buffer_copy(buffer(b), db.data()));
std::size_t need;
fh.len = b[1] & 0x7f;
switch(fh.len)
{
case 126: need = 2; break;
case 127: need = 8; break;
default:
need = 0;
}
fh.mask = (b[1] & 0x80) != 0;
if(fh.mask)
need += 4;
fh.op = static_cast<opcode>(b[0] & 0x0f);
fh.fin = (b[0] & 0x80) != 0;
fh.rsv1 = (b[0] & 0x40) != 0;
fh.rsv2 = (b[0] & 0x20) != 0;
fh.rsv3 = (b[0] & 0x10) != 0;
switch(fh.op)
{
case opcode::binary:
case opcode::text:
if(rd_.cont)
{
// new data frame when continuation expected
return err(close_code::protocol_error);
}
if((fh.rsv1 && ! pmd_) ||
fh.rsv2 || fh.rsv3)
{
// reserved bits not cleared
return err(close_code::protocol_error);
}
if(pmd_)
pmd_->rd_set = fh.rsv1;
break;
case opcode::cont:
if(! rd_.cont)
{
// continuation without an active message
return err(close_code::protocol_error);
}
if(fh.rsv1 || fh.rsv2 || fh.rsv3)
{
// reserved bits not cleared
return err(close_code::protocol_error);
}
break;
default:
if(is_reserved(fh.op))
{
// reserved opcode
return err(close_code::protocol_error);
}
if(! fh.fin)
{
// fragmented control message
return err(close_code::protocol_error);
}
if(fh.len > 125)
{
// invalid length for control message
return err(close_code::protocol_error);
}
if(fh.rsv1 || fh.rsv2 || fh.rsv3)
{
// reserved bits not cleared
return err(close_code::protocol_error);
}
break;
}
// unmasked frame from client
if(role_ == role_type::server && ! fh.mask)
{
code = close_code::protocol_error;
return 0;
}
// masked frame from server
if(role_ == role_type::client && fh.mask)
{
code = close_code::protocol_error;
return 0;
}
code = close_code::none;
return need;
}
// Decode variable frame header from buffer
//
template<class DynamicBuffer>
void
stream_base::
read_fh2(detail::frame_header& fh,
DynamicBuffer& db, close_code& code)
{
using boost::asio::buffer;
using boost::asio::buffer_copy;
using boost::asio::buffer_size;
using namespace boost::endian;
switch(fh.len)
{
case 126:
{
std::uint8_t b[2];
BOOST_ASSERT(buffer_size(db.data()) >= sizeof(b));
db.consume(buffer_copy(buffer(b), db.data()));
fh.len = big_uint16_to_native(&b[0]);
// length not canonical
if(fh.len < 126)
{
code = close_code::protocol_error;
return;
}
break;
}
case 127:
{
std::uint8_t b[8];
BOOST_ASSERT(buffer_size(db.data()) >= sizeof(b));
db.consume(buffer_copy(buffer(b), db.data()));
fh.len = big_uint64_to_native(&b[0]);
// length not canonical
if(fh.len < 65536)
{
code = close_code::protocol_error;
return;
}
break;
}
}
if(fh.mask)
{
std::uint8_t b[4];
BOOST_ASSERT(buffer_size(db.data()) >= sizeof(b));
db.consume(buffer_copy(buffer(b), db.data()));
fh.key = little_uint32_to_native(&b[0]);
}
else
{
// initialize this otherwise operator== breaks
fh.key = 0;
}
if(! is_control(fh.op))
{
if(fh.op != opcode::cont)
{
rd_.size = 0;
rd_.op = fh.op;
}
else
{
if(rd_.size > (std::numeric_limits<
std::uint64_t>::max)() - fh.len)
{
code = close_code::too_big;
return;
}
}
rd_.cont = ! fh.fin;
}
code = close_code::none;
}
template<class>
void
stream_base::
rd_begin()
{
// Maintain the read buffer
if(pmd_)
{
if(! rd_.buf || rd_.buf_size != rd_buf_size_)
{
rd_.buf_size = rd_buf_size_;
rd_.buf.reset(new std::uint8_t[rd_.buf_size]);
}
}
}
template<class>
void
stream_base::
wr_begin()
{
wr_.autofrag = wr_autofrag_;
wr_.compress = static_cast<bool>(pmd_);
// Maintain the write buffer
if( wr_.compress ||
role_ == detail::role_type::client)
{
if(! wr_.buf || wr_.buf_size != wr_buf_size_)
{
wr_.buf_size = wr_buf_size_;
wr_.buf.reset(new std::uint8_t[wr_.buf_size]);
}
}
else
{
wr_.buf_size = wr_buf_size_;
wr_.buf.reset();
}
}
template<class DynamicBuffer>
void
stream_base::
write_close(DynamicBuffer& db, close_reason const& cr)
{
using namespace boost::endian;
frame_header fh;
fh.op = opcode::close;
fh.fin = true;
fh.rsv1 = false;
fh.rsv2 = false;
fh.rsv3 = false;
fh.len = cr.code == close_code::none ?
0 : 2 + cr.reason.size();
fh.mask = role_ == detail::role_type::client;
if(fh.mask)
fh.key = maskgen_();
detail::write(db, fh);
if(cr.code != close_code::none)
{
detail::prepared_key key;
if(fh.mask)
detail::prepare_key(key, fh.key);
{
std::uint8_t b[2];
::new(&b[0]) big_uint16_buf_t{
(std::uint16_t)cr.code};
auto d = db.prepare(2);
boost::asio::buffer_copy(d,
boost::asio::buffer(b));
if(fh.mask)
detail::mask_inplace(d, key);
db.commit(2);
}
if(! cr.reason.empty())
{
auto d = db.prepare(cr.reason.size());
boost::asio::buffer_copy(d,
boost::asio::const_buffer(
cr.reason.data(), cr.reason.size()));
if(fh.mask)
detail::mask_inplace(d, key);
db.commit(cr.reason.size());
}
}
}
template<class DynamicBuffer>
void
stream_base::
write_ping(
DynamicBuffer& db, opcode op, ping_data const& data)
{
frame_header fh;
fh.op = op;
fh.fin = true;
fh.rsv1 = false;
fh.rsv2 = false;
fh.rsv3 = false;
fh.len = data.size();
fh.mask = role_ == role_type::client;
if(fh.mask)
fh.key = maskgen_();
detail::write(db, fh);
if(data.empty())
return;
detail::prepared_key key;
if(fh.mask)
detail::prepare_key(key, fh.key);
auto d = db.prepare(data.size());
boost::asio::buffer_copy(d,
boost::asio::const_buffers_1(
data.data(), data.size()));
if(fh.mask)
detail::mask_inplace(d, key);
db.commit(data.size());
}
} // detail
} // websocket
} // beast
#endif