1 
2 /**
3  *    Copyright (C) 2018-present MongoDB, Inc.
4  *
5  *    This program is free software: you can redistribute it and/or modify
6  *    it under the terms of the Server Side Public License, version 1,
7  *    as published by MongoDB, Inc.
8  *
9  *    This program is distributed in the hope that it will be useful,
10  *    but WITHOUT ANY WARRANTY; without even the implied warranty of
11  *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  *    Server Side Public License for more details.
13  *
14  *    You should have received a copy of the Server Side Public License
15  *    along with this program. If not, see
16  *    <http://www.mongodb.com/licensing/server-side-public-license>.
17  *
18  *    As a special exception, the copyright holders give permission to link the
19  *    code of portions of this program with the OpenSSL library under certain
20  *    conditions as described in each individual source file and distribute
21  *    linked combinations including the program with the OpenSSL library. You
22  *    must comply with the Server Side Public License in all respects for
23  *    all of the code used other than as permitted herein. If you modify file(s)
24  *    with this exception, you may extend this exception to your version of the
25  *    file(s), but you are not obligated to do so. If you do not wish to do so,
26  *    delete this exception statement from your version. If you delete this
27  *    exception statement from all source files in the program, then also delete
28  *    it in the license file.
29  */
30 
31 #pragma once
32 
33 #include "mongo/executor/network_connection_hook.h"
34 
35 namespace mongo {
36 
37 /**
38  * An implementation of NetworkConnectionHook for handling sharding-specific operations such
39  * as sending sharding initialization information to shards and maintaining this process' notion of
40  * the config server optime.
41  */
42 class ShardingNetworkConnectionHook final : public executor::NetworkConnectionHook {
43 public:
44     ShardingNetworkConnectionHook() = default;
45     virtual ~ShardingNetworkConnectionHook() = default;
46 
47     /**
48      * Checks that the given host is valid to be used in this sharded cluster, based on its
49      * isMaster response.
50      */
51     Status validateHost(const HostAndPort& remoteHost,
52                         const executor::RemoteCommandResponse& isMasterReply) override;
53 
54     /**
55      * Implementation of validateHost can be called without a ShardingNetworkConnectionHook
56      * instance.
57      */
58     static Status validateHostImpl(const HostAndPort& remoteHost,
59                                    const executor::RemoteCommandResponse& isMasterReply);
60 
61     /**
62      * Makes a SetShardVersion request for initializing sharding information on the new connection.
63      */
64     StatusWith<boost::optional<executor::RemoteCommandRequest>> makeRequest(
65         const HostAndPort& remoteHost) override;
66 
67     /**
68      * Confirms that the SetShardVersion request made in makeRequest ran successfully.
69      */
70     Status handleReply(const HostAndPort& remoteHost,
71                        executor::RemoteCommandResponse&& response) override;
72 };
73 
74 }  // namespace mongo
75