1 files changed, 136 insertions, 0 deletions
diff --git a/src/torcontrol.h b/src/torcontrol.h
index 00f19db6ae..7258f27cb6 100644
--- a/src/torcontrol.h
+++ b/src/torcontrol.h
@@ -8,7 +8,19 @@
 #ifndef BITCOIN_TORCONTROL_H
 #define BITCOIN_TORCONTROL_H
 
+#include <fs.h>
+#include <netaddress.h>
+
+#include <boost/signals2/signal.hpp>
+
+#include <event2/bufferevent.h>
+#include <event2/event.h>
+
+#include <cstdlib>
+#include <deque>
+#include <functional>
 #include <string>
+#include <vector>
 
 class CService;
 
@@ -21,4 +33,128 @@ void StopTorControl();
 
 CService DefaultOnionServiceTarget();
 
+/** Reply from Tor, can be single or multi-line */
+class TorControlReply
+{
+public:
+    TorControlReply() { Clear(); }
+
+    int code;
+    std::vector<std::string> lines;
+
+    void Clear()
+    {
+        code = 0;
+        lines.clear();
+    }
+};
+
+/** Low-level handling for Tor control connection.
+ * Speaks the SMTP-like protocol as defined in torspec/control-spec.txt
+ */
+class TorControlConnection
+{
+public:
+    typedef std::function<void(TorControlConnection&)> ConnectionCB;
+    typedef std::function<void(TorControlConnection &,const TorControlReply &)> ReplyHandlerCB;
+
+    /** Create a new TorControlConnection.
+     */
+    explicit TorControlConnection(struct event_base *base);
+    ~TorControlConnection();
+
+    /**
+     * Connect to a Tor control port.
+     * tor_control_center is address of the form host:port.
+     * connected is the handler that is called when connection is successfully established.
+     * disconnected is a handler that is called when the connection is broken.
+     * Return true on success.
+     */
+    bool Connect(const std::string& tor_control_center, const ConnectionCB& connected, const ConnectionCB& disconnected);
+
+    /**
+     * Disconnect from Tor control port.
+     */
+    void Disconnect();
+
+    /** Send a command, register a handler for the reply.
+     * A trailing CRLF is automatically added.
+     * Return true on success.
+     */
+    bool Command(const std::string &cmd, const ReplyHandlerCB& reply_handler);
+
+    /** Response handlers for async replies */
+    boost::signals2::signal<void(TorControlConnection &,const TorControlReply &)> async_handler;
+private:
+    /** Callback when ready for use */
+    std::function<void(TorControlConnection&)> connected;
+    /** Callback when connection lost */
+    std::function<void(TorControlConnection&)> disconnected;
+    /** Libevent event base */
+    struct event_base *base;
+    /** Connection to control socket */
+    struct bufferevent *b_conn;
+    /** Message being received */
+    TorControlReply message;
+    /** Response handlers */
+    std::deque<ReplyHandlerCB> reply_handlers;
+
+    /** Libevent handlers: internal */
+    static void readcb(struct bufferevent *bev, void *ctx);
+    static void eventcb(struct bufferevent *bev, short what, void *ctx);
+};
+
+/****** Bitcoin specific TorController implementation ********/
+
+/** Controller that connects to Tor control socket, authenticate, then create
+ * and maintain an ephemeral onion service.
+ */
+class TorController
+{
+public:
+    TorController(struct event_base* base, const std::string& tor_control_center, const CService& target);
+    TorController() : conn{nullptr} {
+        // Used for testing only.
+    }
+    ~TorController();
+
+    /** Get name of file to store private key in */
+    fs::path GetPrivateKeyFile();
+
+    /** Reconnect, after getting disconnected */
+    void Reconnect();
+private:
+    struct event_base* base;
+    const std::string m_tor_control_center;
+    TorControlConnection conn;
+    std::string private_key;
+    std::string service_id;
+    bool reconnect;
+    struct event *reconnect_ev = nullptr;
+    float reconnect_timeout;
+    CService service;
+    const CService m_target;
+    /** Cookie for SAFECOOKIE auth */
+    std::vector<uint8_t> cookie;
+    /** ClientNonce for SAFECOOKIE auth */
+    std::vector<uint8_t> clientNonce;
+
+public:
+    /** Callback for ADD_ONION result */
+    void add_onion_cb(TorControlConnection& conn, const TorControlReply& reply);
+    /** Callback for AUTHENTICATE result */
+    void auth_cb(TorControlConnection& conn, const TorControlReply& reply);
+    /** Callback for AUTHCHALLENGE result */
+    void authchallenge_cb(TorControlConnection& conn, const TorControlReply& reply);
+    /** Callback for PROTOCOLINFO result */
+    void protocolinfo_cb(TorControlConnection& conn, const TorControlReply& reply);
+    /** Callback after successful connection */
+    void connected_cb(TorControlConnection& conn);
+    /** Callback after connection lost or failed connection attempt */
+    void disconnected_cb(TorControlConnection& conn);
+
+    /** Callback for reconnect timer */
+    static void reconnect_cb(evutil_socket_t fd, short what, void *arg);
+};
+
 #endif /* BITCOIN_TORCONTROL_H */