Added support for "noise" over I1P/Tor to mask Tx transmission.

1 files changed, 106 insertions, 0 deletions

diff --git a/src/net/dandelionpp.h b/src/net/dandelionpp.h
new file mode 100644
index 000000000..75b63bc0c
--- /dev/null
+++ b/src/net/dandelionpp.h
@@ -0,0 +1,106 @@
+// Copyright (c) 2019, The Monero Project
+//
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without modification, are
+// permitted provided that the following conditions are met:
+//
+// 1. Redistributions of source code must retain the above copyright notice, this list of
+//    conditions and the following disclaimer.
+//
+// 2. Redistributions in binary form must reproduce the above copyright notice, this list
+//    of conditions and the following disclaimer in the documentation and/or other
+//    materials provided with the distribution.
+//
+// 3. Neither the name of the copyright holder nor the names of its contributors may be
+//    used to endorse or promote products derived from this software without specific
+//    prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
+// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#pragma once
+
+#include <boost/uuid/uuid.hpp>
+#include <cstddef>
+#include <memory>
+#include <utility>
+#include <vector>
+
+#include "span.h"
+
+namespace net
+{
+namespace dandelionpp
+{
+    //! Assists with mapping source -> stem and tracking connections for stem.
+    class connection_map
+    {
+        // Make sure to update clone method if changing members
+        std::vector<boost::uuids::uuid> out_mapping_; //<! Current outgoing uuid connection at index.
+        std::vector<std::pair<boost::uuids::uuid, std::size_t>> in_mapping_; //<! uuid source to an `out_mapping_` index.
+        std::vector<std::size_t> usage_count_;
+
+        // Use clone method to prevent "hidden" copies.
+        connection_map(const connection_map&) = default;
+
+    public:
+        using value_type = boost::uuids::uuid;
+        using size_type = std::vector<boost::uuids::uuid>::size_type;
+        using difference_type = std::vector<boost::uuids::uuid>::difference_type;
+        using reference = const boost::uuids::uuid&;
+        using const_reference = reference;
+        using iterator = std::vector<boost::uuids::uuid>::const_iterator;
+        using const_iterator = iterator;
+
+        //! Initialized with zero stem connections.
+        explicit connection_map()
+          : connection_map(std::vector<boost::uuids::uuid>{}, 0)
+        {}
+
+        //! Initialized with `out_connections` and `stem_count`.
+        explicit connection_map(std::vector<boost::uuids::uuid> out_connections, std::size_t stems);
+
+        connection_map(connection_map&&) = default;
+        ~connection_map() noexcept;
+        connection_map& operator=(connection_map&&) = default;
+        connection_map& operator=(const connection_map&) = delete;
+
+        //! \return An exact duplicate of `this` map.
+        connection_map clone() const;
+
+        //! \return First stem connection.
+        const_iterator begin() const noexcept
+        {
+            return out_mapping_.begin();
+        }
+
+        //! \return One-past the last stem connection.
+        const_iterator end() const noexcept
+        {
+            return out_mapping_.end();
+        }
+
+        /*! Merges in current connections with the previous set of connections.
+            If a connection died, a new one will take its place in the stem or
+            the stem is marked as dead.
+
+            \param connections Current outbound connection ids.
+            \return True if any updates to `get_connections()` was made. */
+        bool update(std::vector<boost::uuids::uuid> current);
+
+        //! \return Number of outgoing connections in use.
+        std::size_t size() const noexcept;
+
+        //! \return Current stem mapping for `source` or `nil_uuid()` if none is possible.
+        boost::uuids::uuid get_stem(const boost::uuids::uuid& source);
+    };
+} // dandelionpp
+} // net