1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
|
/**
* Copyright (C) 2018-present MongoDB, Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the Server Side Public License, version 1,
* as published by MongoDB, Inc.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* Server Side Public License for more details.
*
* You should have received a copy of the Server Side Public License
* along with this program. If not, see
* <http://www.mongodb.com/licensing/server-side-public-license>.
*
* As a special exception, the copyright holders give permission to link the
* code of portions of this program with the OpenSSL library under certain
* conditions as described in each individual source file and distribute
* linked combinations including the program with the OpenSSL library. You
* must comply with the Server Side Public License in all respects for
* all of the code used other than as permitted herein. If you modify file(s)
* with this exception, you may extend this exception to your version of the
* file(s), but you are not obligated to do so. If you do not wish to do so,
* delete this exception statement from your version. If you delete this
* exception statement from all source files in the program, then also delete
* it in the license file.
*/
#pragma once
#include <cstdint>
#include <string>
#include <type_traits>
#include "mongo/base/status_with.h"
#include "mongo/db/wire_version.h"
#include "mongo/rpc/message.h"
namespace mongo {
class BSONObj;
class OperationContext;
namespace rpc {
/**
* Bit flags representing support for a particular RPC protocol.
* This is just an internal representation, and is never transmitted over the wire. It should
* never be used for any other feature detection in favor of max/min wire version.
*
* A new protocol must be added as the highest order bit flag so that it is prioritized in
* negotiation.
*/
enum class Protocol : std::uint64_t {
/**
* The pre-3.2 OP_QUERY on db.$cmd protocol
*/
kOpQuery = 1 << 0,
/**
* The 3.6+ OP_MSG protocol.
*/
kOpMsg = 1 << 1,
};
/**
* Bitfield representing a set of supported RPC protocols.
*/
using ProtocolSet = std::underlying_type<Protocol>::type;
/**
* This namespace contains predefined bitfields for common levels of protocol support.
*/
namespace supports {
const ProtocolSet kNone = ProtocolSet{0};
const ProtocolSet kOpQueryOnly = static_cast<ProtocolSet>(Protocol::kOpQuery);
const ProtocolSet kOpMsgOnly = static_cast<ProtocolSet>(Protocol::kOpMsg);
const ProtocolSet kAll = kOpQueryOnly | kOpMsgOnly;
} // namespace supports
Protocol protocolForMessage(const Message& message);
/**
* Returns the protocol used to initiate the current operation.
*/
Protocol getOperationProtocol(OperationContext* opCtx);
/**
* Sets the protocol used to initiate the current operation.
*/
void setOperationProtocol(OperationContext* opCtx, Protocol protocol);
/**
* Returns the newest protocol supported by two parties.
*/
StatusWith<Protocol> negotiate(ProtocolSet fst, ProtocolSet snd);
/**
* Converts a ProtocolSet to a string. Currently only the predefined ProtocolSets in the
* 'supports' namespace are supported.
*
* This intentionally does not conform to the STL 'to_string' convention so that it will
* not conflict with the to_string overload for uint64_t.
*/
StatusWith<StringData> toString(ProtocolSet protocols);
/**
* Parses a ProtocolSet from a string. Currently only the predefined ProtocolSets in the
* 'supports' namespace are supported
*/
StatusWith<ProtocolSet> parseProtocolSet(StringData repr);
/**
* Validates client and server wire version. The server is returned from isMaster, and the client is
* from WireSpec.instance().
*/
Status validateWireVersion(const WireVersionInfo client, const WireVersionInfo server);
/**
* Struct to pass around information about protocol set and wire version.
*/
struct ProtocolSetAndWireVersionInfo {
ProtocolSet protocolSet;
WireVersionInfo version;
};
/**
* Determines the ProtocolSet of a remote server from an isMaster reply.
*/
StatusWith<ProtocolSetAndWireVersionInfo> parseProtocolSetFromIsMasterReply(
const BSONObj& isMasterReply);
/**
* Computes supported protocols from wire versions.
*/
ProtocolSet computeProtocolSet(const WireVersionInfo version);
} // namespace rpc
} // namespace mongo
|
