Merge pull request #10782 from obsidiansystems/both-connections

Factor our connection code for worker proto like serve proto

src/libstore/worker-protocol.hh

@@ -77,6 +77,19 @@ struct WorkerProto
         Version version;
     };
 
+    /**
+     * Stripped down serialization logic suitable for sharing with Hydra.
+     *
+     * @todo remove once Hydra uses Store abstraction consistently.
+     */
+    struct BasicClientConnection;
+    struct BasicServerConnection;
+
+    /**
+     * Extra information provided as part of protocol negotation.
+     */
+    struct ClientHandshakeInfo;
+
     /**
      * Data type for canonical pairs of serialisers for the worker protocol.
      *
@@ -167,6 +180,33 @@ enum struct WorkerProto::Op : uint64_t
     AddPermRoot = 47,
 };
 
+struct WorkerProto::ClientHandshakeInfo
+{
+    /**
+     * The version of the Nix daemon that is processing our requests
+.
+     *
+     * Do note, it may or may not communicating with another daemon,
+     * rather than being an "end" `LocalStore` or similar.
+     */
+    std::optional<std::string> daemonNixVersion;
+
+    /**
+     * Whether the remote side trusts us or not.
+     *
+     * 3 values: "yes", "no", or `std::nullopt` for "unknown".
+     *
+     * Note that the "remote side" might not be just the end daemon, but
+     * also an intermediary forwarder that can make its own trusting
+     * decisions. This would be the intersection of all their trust
+     * decisions, since it takes only one link in the chain to start
+     * denying operations.
+     */
+    std::optional<TrustedFlag> remoteTrustsUs;
+
+    bool operator == (const ClientHandshakeInfo &) const = default;
+};
+
 /**
  * Convenience for sending operation codes.
  *
@@ -221,6 +261,8 @@ template<>
 DECLARE_WORKER_SERIALISER(std::optional<TrustedFlag>);
 template<>
 DECLARE_WORKER_SERIALISER(std::optional<std::chrono::microseconds>);
+template<>
+DECLARE_WORKER_SERIALISER(WorkerProto::ClientHandshakeInfo);
 
 template<typename T>
 DECLARE_WORKER_SERIALISER(std::vector<T>);