SERVER-50375 Ensure mongos forwards API params to shards

1 files changed, 122 insertions, 0 deletions

diff --git a/src/mongo/db/api_parameters.h b/src/mongo/db/api_parameters.h
new file mode 100644
index 00000000000..7539dcb345e
--- /dev/null
+++ b/src/mongo/db/api_parameters.h
@@ -0,0 +1,122 @@
+/**
+ *    Copyright (C) 2020-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/api_parameters_gen.h"
+#include "mongo/db/operation_context.h"
+
+namespace mongo {
+
+/**
+ * Decorates operation context with methods to retrieve apiVersion, apiStrict, and
+ * apiDeprecationErrors.
+ */
+class APIParameters {
+
+public:
+    static constexpr StringData kAPIVersionFieldName = "apiVersion"_sd;
+    static constexpr StringData kAPIStrictFieldName = "apiStrict"_sd;
+    static constexpr StringData kAPIDeprecationErrorsFieldName = "apiDeprecationErrors"_sd;
+
+    static const OperationContext::Decoration<APIParameters> get;
+    static APIParameters fromClient(const APIParametersFromClient& apiParamsFromClient);
+    static APIParameters fromBSON(const BSONObj& cmdObj);
+
+    void appendInfo(BSONObjBuilder* builder) const;
+
+    const boost::optional<std::string>& getAPIVersion() const {
+        return _apiVersion;
+    }
+
+    void setAPIVersion(StringData apiVersion) {
+        _apiVersion = apiVersion.toString();
+    }
+
+    const boost::optional<bool>& getAPIStrict() const {
+        return _apiStrict;
+    }
+
+    void setAPIStrict(bool apiStrict) {
+        _apiStrict = apiStrict;
+    }
+
+    const boost::optional<bool>& getAPIDeprecationErrors() const {
+        return _apiDeprecationErrors;
+    }
+
+    void setAPIDeprecationErrors(bool apiDeprecationErrors) {
+        _apiDeprecationErrors = apiDeprecationErrors;
+    }
+
+    const bool getParamsPassed() const {
+        return _apiVersion || _apiStrict || _apiDeprecationErrors;
+    }
+
+private:
+    boost::optional<std::string> _apiVersion;
+    boost::optional<bool> _apiStrict;
+    boost::optional<bool> _apiDeprecationErrors;
+};
+
+
+/**
+ * Temporarily remove the user's API parameters from an OperationContext.
+ */
+class IgnoreAPIParametersBlock {
+public:
+    IgnoreAPIParametersBlock() = delete;
+    IgnoreAPIParametersBlock(const IgnoreAPIParametersBlock&) = delete;
+    IgnoreAPIParametersBlock& operator=(const IgnoreAPIParametersBlock&) = delete;
+
+    explicit IgnoreAPIParametersBlock(OperationContext* opCtx) : _opCtx(opCtx) {
+        _apiParams = APIParameters::get(_opCtx);
+        APIParameters::get(_opCtx) = APIParameters();
+    }
+
+    void release() {
+        if (_released) {
+            return;
+        }
+
+        APIParameters::get(_opCtx) = _apiParams;
+        _released = true;
+    }
+
+    ~IgnoreAPIParametersBlock() {
+        release();
+    }
+
+private:
+    OperationContext* _opCtx;
+    APIParameters _apiParams;
+    bool _released = false;
+};
+
+}  // namespace mongo