summaryrefslogtreecommitdiff
path: root/src/mongo/db/kill_sessions_common.h
blob: 5e749709a1b350a3b2af47dc2d7f5a1addf9a913 (plain)
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
/**
 *    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 "mongo/db/kill_sessions.h"

#include <vector>

#include "mongo/base/status.h"
#include "mongo/db/auth/authorization_session.h"
#include "mongo/db/operation_context.h"
#include "mongo/db/session_killer.h"
#include "mongo/stdx/unordered_set.h"
#include "mongo/util/str.h"

namespace mongo {

/**
 * Local killing involves looping over all local operations, checking to see if they have matching
 * logical session ids, and killing if they do.
 */
SessionKiller::Result killSessionsLocalKillOps(OperationContext* opCtx,
                                               const SessionKiller::Matcher& matcher);

/**
 * Helper for executing a pattern set from a kill sessions style command.
 */
Status killSessionsCmdHelper(OperationContext* opCtx,
                             BSONObjBuilder& result,
                             const KillAllSessionsByPatternSet& patterns);

class ScopedKillAllSessionsByPatternImpersonator {
public:
    ScopedKillAllSessionsByPatternImpersonator(OperationContext* opCtx,
                                               const KillAllSessionsByPattern& pattern) {
        AuthorizationSession* authSession = AuthorizationSession::get(opCtx->getClient());

        if (pattern.getUsers() && pattern.getRoles()) {
            std::tie(_names, _roles) = getKillAllSessionsByPatternImpersonateData(pattern);
            _raii.emplace(authSession, &_names, &_roles);
        }
    }

private:
    std::vector<UserName> _names;
    std::vector<RoleName> _roles;
    boost::optional<AuthorizationSession::ScopedImpersonate> _raii;
};

/**
 * This elaborate bit of artiface helps us to adapt the shape of a cursor manager that we know from
 * logical sessions with the different ways to cancel cursors in mongos versus mongod.  I.e. the
 * two types share no code, but do share enough shape to re-use some boilerplate.
 */
template <typename Eraser>
class KillCursorsBySessionAdaptor {
public:
    KillCursorsBySessionAdaptor(OperationContext* opCtx,
                                const SessionKiller::Matcher& matcher,
                                Eraser&& eraser)
        : _opCtx(opCtx), _matcher(matcher), _cursorsKilled(0), _eraser(eraser) {}

    /**
     * Kills cursors in 'mgr' which belong to a session matching the SessionKilled::Matcher with
     * which this adaptor was constructed.
     */
    template <typename Mgr>
    void operator()(Mgr& mgr) noexcept {
        LogicalSessionIdSet activeSessions;
        mgr.appendActiveSessions(&activeSessions);

        for (const auto& session : activeSessions) {
            if (const KillAllSessionsByPattern* pattern = _matcher.match(session)) {
                ScopedKillAllSessionsByPatternImpersonator impersonator(_opCtx, *pattern);

                auto cursors = mgr.getCursorsForSession(session);
                for (const auto& id : cursors) {
                    try {
                        _eraser(mgr, id);
                        _cursorsKilled++;
                    } catch (const ExceptionFor<ErrorCodes::CursorNotFound>&) {
                        // Cursor was killed separately after this command was initiated. Still
                        // count the cursor as killed here, since the user's request is
                        // technically satisfied.
                        _cursorsKilled++;
                    } catch (const DBException& ex) {
                        _failures.push_back(ex.toStatus());
                    }
                }
            }
        }
    }

    /**
     * Returns an OK status if no errors were encountered during cursor killing, or a non-OK status
     * summarizing any errors encountered.
     */
    Status getStatus() const {
        if (_failures.empty()) {
            return Status::OK();
        }

        if (_failures.size() == 1) {
            return _failures.back();
        }

        return Status(_failures.back().code(),
                      str::stream() << "Encountered " << _failures.size()
                                    << " errors while killing cursors, "
                                       "showing most recent error: "
                                    << _failures.back().reason());
    }

    /**
     * Returns the number of cursors killed by operator().
     */
    int getCursorsKilled() const {
        return _cursorsKilled;
    }

private:
    OperationContext* _opCtx;
    const SessionKiller::Matcher& _matcher;
    std::vector<Status> _failures;
    int _cursorsKilled;
    Eraser _eraser;
};

template <typename Eraser>
auto makeKillCursorsBySessionAdaptor(OperationContext* opCtx,
                                     const SessionKiller::Matcher& matcher,
                                     Eraser&& eraser) {
    return KillCursorsBySessionAdaptor<std::decay_t<Eraser>>{
        opCtx, matcher, std::forward<Eraser>(eraser)};
}

}  // namespace mongo