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/*
*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*
*/
#include "AMQFrame.h"
#include "qpid/QpidError.h"
#include "qpid/framing/variant.h"
#include "qpid/framing/AMQMethodBody.h"
#include <boost/format.hpp>
#include <iostream>
namespace qpid {
namespace framing {
namespace {
struct GetBodyVisitor : public NoBlankVisitor<AMQBody*> {
QPID_USING_NOBLANK(AMQBody*);
AMQBody* operator()(MethodHolder& t) const { return t.get(); }
template <class T> AMQBody* operator()(T& t) const { return &t; }
};
struct EncodeVisitor : public NoBlankVisitor<void> {
Buffer& buffer;
EncodeVisitor(Buffer& b) : buffer(b) {}
QPID_USING_NOBLANK(void);
template <class T> void operator()(const T& t) const { return t.encode(buffer); }
};
struct SizeVisitor : public NoBlankVisitor<uint32_t> {
QPID_USING_NOBLANK(uint32_t);
template <class T> uint32_t operator()(const T& t) const { return t.size(); }
};
struct DecodeVisitor : public NoBlankVisitor<void> {
Buffer& buffer;
uint32_t size;
DecodeVisitor(Buffer& b, uint32_t s) : buffer(b), size(s) {}
QPID_USING_NOBLANK(void);
void operator()(MethodHolder& t) const { return t.decode(buffer); }
template <class T> void operator()(T& t) const { return t.decode(buffer, size); }
};
}
AMQBody* AMQFrame::getBody() {
return boost::apply_visitor(GetBodyVisitor(), body);
}
const AMQBody* AMQFrame::getBody() const {
return boost::apply_visitor(GetBodyVisitor(), const_cast<Variant&>(body));
}
// This is now misleadingly named as it is not the frame size as defined in the spec
// (as it also includes the end marker)
uint32_t AMQFrame::size() const{
return frameOverhead() + boost::apply_visitor(SizeVisitor(), body);
}
uint32_t AMQFrame::frameOverhead() {
return 12 /*frame header*/ + 1/*0xCE*/;
}
void AMQFrame::encode(Buffer& buffer) const
{
uint8_t flags = (bof ? 0x08 : 0) | (eof ? 0x04 : 0) | (bos ? 0x02 : 0) | (eos ? 0x01 : 0);
buffer.putOctet(flags);
buffer.putOctet(getBody()->type());
buffer.putShort(size() - 1); // Don't include end marker (it's not part of the frame itself)
buffer.putOctet(0);
buffer.putOctet(0x0f & subchannel);
buffer.putShort(channel);
buffer.putLong(0);
boost::apply_visitor(EncodeVisitor(buffer), body);
buffer.putOctet(0xCE);
}
bool AMQFrame::decode(Buffer& buffer)
{
if(buffer.available() < frameOverhead() - 1)
return false;
buffer.record();
uint8_t flags = buffer.getOctet();
uint8_t framing_version = (flags & 0xc0) >> 6;
if (framing_version != 0)
THROW_QPID_ERROR(FRAMING_ERROR, "Framing version unsupported");
bof = flags & 0x08;
eof = flags & 0x04;
bos = flags & 0x02;
eos = flags & 0x01;
uint8_t type = buffer.getOctet();
uint16_t frame_size = buffer.getShort();
if (frame_size < frameOverhead()-1)
THROW_QPID_ERROR(FRAMING_ERROR, "Frame size too small");
uint8_t reserved1 = buffer.getOctet();
uint8_t field1 = buffer.getOctet();
subchannel = field1 & 0x0f;
channel = buffer.getShort();
(void) buffer.getLong(); // reserved2
// Verify that the protocol header meets current spec
// TODO: should we check reserved2 against zero as well? - the spec isn't clear
if ((flags & 0x30) != 0 || reserved1 != 0 || (field1 & 0xf0) != 0)
THROW_QPID_ERROR(FRAMING_ERROR, "Reserved bits not zero");
// TODO: should no longer care about body size and only pass up B,E,b,e flags
uint16_t body_size = frame_size + 1 - frameOverhead();
if (buffer.available() < body_size+1u){
buffer.restore();
return false;
}
decodeBody(buffer, body_size, type);
uint8_t end = buffer.getOctet();
if (end != 0xCE)
THROW_QPID_ERROR(FRAMING_ERROR, "Frame end not found");
return true;
}
void AMQFrame::decodeBody(Buffer& buffer, uint32_t size, uint8_t type)
{
switch(type)
{
case METHOD_BODY: body = MethodHolder(); break;
case HEADER_BODY: body = AMQHeaderBody(); break;
case CONTENT_BODY: body = AMQContentBody(); break;
case HEARTBEAT_BODY: body = AMQHeartbeatBody(); break;
default:
THROW_QPID_ERROR(
FRAMING_ERROR,
boost::format("Unknown frame type %d") % type);
}
boost::apply_visitor(DecodeVisitor(buffer,size), body);
}
std::ostream& operator<<(std::ostream& out, const AMQFrame& f)
{
return out << "Frame["
<< (f.getBof() ? "B" : "") << (f.getEof() ? "E" : "") << (f.getBos() ? "b" : "") << (f.getEos() ? "e" : "") << "; "
<< "channel=" << f.getChannel() << "; " << *f.getBody()
<< "]";
}
}} // namespace qpid::framing
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