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
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
|
/**
* 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.
*/
#include "mongo/platform/basic.h"
#include "mongo/rpc/protocol.h"
#include <algorithm>
#include <iterator>
#include "mongo/base/string_data.h"
#include "mongo/bson/util/bson_extract.h"
#include "mongo/db/jsobj.h"
#include "mongo/db/wire_version.h"
#include "mongo/util/mongoutils/str.h"
namespace mongo {
namespace rpc {
namespace {
/**
* Protocols supported by order of preference.
*/
const Protocol kPreferredProtos[] = {Protocol::kOpMsg, Protocol::kOpQuery};
struct ProtocolSetAndName {
StringData name;
ProtocolSet protocols;
};
constexpr ProtocolSetAndName protocolSetNames[] = {
// Most common ones go first.
{"all"_sd, supports::kAll}, // new mongod and mongos or very new client.
{"opQueryOnly"_sd, supports::kOpQueryOnly}, // old mongos or mongod or moderately old client.
// Then the rest (these should never happen in production).
{"none"_sd, supports::kNone},
{"opMsgOnly"_sd, supports::kOpMsgOnly},
};
} // namespace
Protocol protocolForMessage(const Message& message) {
switch (message.operation()) {
case mongo::dbMsg:
return Protocol::kOpMsg;
case mongo::dbQuery:
return Protocol::kOpQuery;
default:
uasserted(ErrorCodes::UnsupportedFormat,
str::stream() << "Received a reply message with unexpected opcode: "
<< message.operation());
}
}
StatusWith<Protocol> negotiate(ProtocolSet fst, ProtocolSet snd) {
using std::begin;
using std::end;
ProtocolSet common = fst & snd;
auto it = std::find_if(begin(kPreferredProtos), end(kPreferredProtos), [common](Protocol p) {
return common & static_cast<ProtocolSet>(p);
});
if (it == end(kPreferredProtos)) {
return Status(ErrorCodes::RPCProtocolNegotiationFailed, "No common protocol found.");
}
return *it;
}
StatusWith<StringData> toString(ProtocolSet protocols) {
for (auto& elem : protocolSetNames) {
if (elem.protocols == protocols)
return elem.name;
}
return Status(ErrorCodes::BadValue,
str::stream() << "ProtocolSet " << protocols
<< " does not match any well-known value.");
}
StatusWith<ProtocolSet> parseProtocolSet(StringData name) {
for (auto& elem : protocolSetNames) {
if (elem.name == name)
return elem.protocols;
}
return Status(ErrorCodes::BadValue,
str::stream() << name << " is not a valid name for a ProtocolSet.");
}
StatusWith<ProtocolSetAndWireVersionInfo> parseProtocolSetFromIsMasterReply(
const BSONObj& isMasterReply) {
long long maxWireVersion;
auto maxWireExtractStatus =
bsonExtractIntegerField(isMasterReply, "maxWireVersion", &maxWireVersion);
long long minWireVersion;
auto minWireExtractStatus =
bsonExtractIntegerField(isMasterReply, "minWireVersion", &minWireVersion);
// MongoDB 2.4 and earlier do not have maxWireVersion/minWireVersion in their 'isMaster' replies
if ((maxWireExtractStatus == minWireExtractStatus) &&
(maxWireExtractStatus == ErrorCodes::NoSuchKey)) {
return {{supports::kOpQueryOnly, {0, 0}}};
} else if (!maxWireExtractStatus.isOK()) {
return maxWireExtractStatus;
} else if (!minWireExtractStatus.isOK()) {
return minWireExtractStatus;
}
if (minWireVersion < 0 || maxWireVersion < 0 ||
minWireVersion >= std::numeric_limits<int>::max() ||
maxWireVersion >= std::numeric_limits<int>::max()) {
return Status(ErrorCodes::IncompatibleServerVersion,
str::stream() << "Server min and max wire version have invalid values ("
<< minWireVersion
<< ","
<< maxWireVersion
<< ")");
}
WireVersionInfo version{static_cast<int>(minWireVersion), static_cast<int>(maxWireVersion)};
auto protos = computeProtocolSet(version);
return {{protos, version}};
}
ProtocolSet computeProtocolSet(const WireVersionInfo version) {
ProtocolSet result = supports::kNone;
if (version.minWireVersion <= version.maxWireVersion) {
if (version.maxWireVersion >= WireVersion::SUPPORTS_OP_MSG) {
result |= supports::kOpMsgOnly;
}
if (version.minWireVersion <= WireVersion::RELEASE_2_4_AND_BEFORE) {
result |= supports::kOpQueryOnly;
}
// Note: this means anything using the internal handshake cannot talk to servers between 2.6
// and 3.6, since the servers will reply with higher minWireVersions. The shell should still
// be able to connect to those versions but will just use OP_QUERY to run commands.
}
return result;
}
Status validateWireVersion(const WireVersionInfo client, const WireVersionInfo server) {
// Since this is defined in the code, it should always hold true since this is the versions that
// mongos/d wants to connect to.
invariant(client.minWireVersion <= client.maxWireVersion);
// Server may return bad data.
if (server.minWireVersion > server.maxWireVersion) {
return Status(ErrorCodes::IncompatibleServerVersion,
str::stream() << "Server min and max wire version are incorrect ("
<< server.minWireVersion
<< ","
<< server.maxWireVersion
<< ")");
}
// Determine if the [min, max] tuples overlap.
// We assert the invariant that min < max above.
if (!(client.minWireVersion <= server.maxWireVersion &&
client.maxWireVersion >= server.minWireVersion)) {
std::string errmsg = str::stream()
<< "Server min and max wire version (" << server.minWireVersion << ","
<< server.maxWireVersion << ") is incompatible with client min wire version ("
<< client.minWireVersion << "," << client.maxWireVersion << ").";
if (client.maxWireVersion < server.minWireVersion) {
return Status(ErrorCodes::IncompatibleWithUpgradedServer,
str::stream()
<< errmsg
<< "You (client) are attempting to connect to a node (server) that "
"no longer accepts connections with your (client’s) binary "
"version. Please upgrade the client’s binary version.");
}
return Status(ErrorCodes::IncompatibleServerVersion,
str::stream() << errmsg
<< "You (client) are attempting to connect to a node "
"(server) with a binary version with which "
"you (client) no longer accept connections. Please "
"upgrade the server’s binary version.");
}
return Status::OK();
}
} // namespace rpc
} // namespace mongo
|
