Protobuf integration

- protobuf added as external dependency
- SessionProtos.pro and WebSocketResources.proto looped in from session-ios codebase
- cmake target implemented s.t. wrapping/unwrapping functions can be defined and implemented in protos.{cpp,hpp}

CMakeLists.txt

@@ -93,6 +93,7 @@ set(CMAKE_POSITION_INDEPENDENT_CODE ON)
 
 add_subdirectory(external)
 add_subdirectory(src)
+add_subdirectory(proto)
 
 if(STATIC_BUNDLE)
     include(combine_archives)

include/session/config/base.hpp

@@ -12,6 +12,7 @@
 
 #include "base.h"
 #include "namespaces.hpp"
+#include "protos.hpp"
 
 namespace session::config {
 
@@ -200,6 +201,12 @@ class ConfigBase : public ConfigSig {
     void set_verifier(ConfigMessage::verify_callable v) override;
     void set_signer(ConfigMessage::sign_callable s) override;
 
+    // Virtual method to be overloaded by derived classes. Protobuf wrapped messages are used
+    // for legacy types, so we need different logic depending on the class in question. All new
+    // types will reject the protobuf and directly handle the binary data. Old types will try
+    // protobuf parsing on incoming messages and handle all outgoing messages directly in binary
+    virtual bool accepts_protobuf() const { return false; }
+
   public:
     // class for proxying subfield access; this class should never be stored but only used
     // ephemerally (most of its methods are rvalue-qualified).  This lets constructs such as
@@ -745,6 +752,36 @@ class ConfigBase : public ConfigSig {
     };
 
   protected:
+    /// API: base/ConfigBase::_merge
+    ///
+    /// Internal implementation of merge. This takes all of the messages pulled down from the server
+    /// and does whatever is necessary to merge (or replace) the current values.
+    ///
+    /// Values are pairs of the message hash (as provided by the server) and the raw message body.
+    ///
+    /// After this call the caller should check `needs_push()` to see if the data on hand was
+    /// updated and needs to be pushed to the server again (for example, because the data contained
+    /// conflicts that required another update to resolve).
+    ///
+    /// Returns the number of the given config messages that were successfully parsed.
+    ///
+    /// Will throw on serious error (i.e. if neither the current nor any of the given configs are
+    /// parseable).  This should not happen (the current config, at least, should always be
+    /// re-parseable).
+    ///
+    /// Declaration:
+    /// ```cpp
+    /// int _merge(const std::vector<std::pair<std::string, ustring_view>>& configs);
+    /// int _merge(const std::vector<std::pair<std::string, ustring>>& configs);
+    /// ```
+    ///
+    /// Inputs:
+    /// - `configs` -- vector of pairs containing the message hash and the raw message body
+    ///
+    /// Outputs:
+    /// - `int` -- Returns how many config messages that were successfully parsed
+    int _merge(const std::vector<std::pair<std::string, ustring_view>>& configs);
+
     /// API: base/ConfigBase::extra_data
     ///
     /// Called when dumping to obtain any extra data that a subclass needs to store to reconstitute
@@ -849,37 +886,23 @@ class ConfigBase : public ConfigSig {
 
     /// API: base/ConfigBase::merge
     ///
-    /// This takes all of the messages pulled down from the server and does whatever is necessary to
-    /// merge (or replace) the current values.
-    ///
-    /// Values are pairs of the message hash (as provided by the server) and the raw message body.
-    ///
-    /// After this call the caller should check `needs_push()` to see if the data on hand was
-    /// updated and needs to be pushed to the server again (for example, because the data contained
-    /// conflicts that required another update to resolve).
-    ///
-    /// Returns the number of the given config messages that were successfully parsed.
-    ///
-    /// Will throw on serious error (i.e. if neither the current nor any of the given configs are
-    /// parseable).  This should not happen (the current config, at least, should always be
-    /// re-parseable).
-    ///
-    /// Declaration:
-    /// ```cpp
-    /// int merge(const std::vector<std::pair<std::string, ustring_view>>& configs);
-    /// int merge(const std::vector<std::pair<std::string, ustring>>& configs);
-    /// ```
+    /// Wrapper around ConfigBase::_merge to handle protobuf parsing. Currently, in the transition
+    /// from legacy to new config groups, legacy groups using protobuf must be compatible with
+    /// new config groups handling raw binary I/O. As a result, this method checks the
+    /// accepts_protobuf() override for the given class, and either passes the parsed protobuf or
+    /// the original binary data to _merge
     ///
     /// Inputs:
     /// - `configs` -- vector of pairs containing the message hash and the raw message body
     ///
     /// Outputs:
     /// - `int` -- Returns how many config messages that were successfully parsed
-    virtual int merge(const std::vector<std::pair<std::string, ustring_view>>& configs);
-
-    // Same as merge (above )but takes the values as ustring's as sometimes that is more convenient.
     int merge(const std::vector<std::pair<std::string, ustring>>& configs);
 
+    // Same as above, but passes the ustring_views to the overload of protos::handle_incoming that
+    // takes ustring_views
+    int merge(const std::vector<std::pair<std::string, ustring_view>>& configs);
+
     /// API: base/ConfigBase::is_dirty
     ///
     /// Returns true if we are currently dirty (i.e. have made changes that haven't been serialized

include/session/config/contacts.hpp

@@ -323,6 +323,8 @@ class Contacts : public ConfigBase {
     /// - `bool` - Returns true if the contact list is empty
     bool empty() const { return size() == 0; }
 
+    bool accepts_protobuf() const override { return true; }
+
     struct iterator;
     /// API: contacts/contacts::begin
     ///

include/session/config/convo_info_volatile.hpp

@@ -529,6 +529,8 @@ class ConvoInfoVolatile : public ConfigBase {
     /// - `bool` -- Returns true if the convesation list is empty
     bool empty() const { return size() == 0; }
 
+    bool accepts_protobuf() const override { return true; }
+
     struct iterator;
     /// API: convo_info_volatile/ConvoInfoVolatile::begin
     ///

include/session/config/user_groups.hpp

@@ -544,6 +544,8 @@ class UserGroups : public ConfigBase {
     /// - `bool` - Returns true if the contact list is empty
     bool empty() const { return size() == 0; }
 
+    bool accepts_protobuf() const override { return true; }
+
     struct iterator;
     /// API: user_groups/UserGroups::begin
     ///

include/session/config/user_profile.hpp

@@ -187,6 +187,8 @@ class UserProfile final : public ConfigBase {
     ///   not, and `std::nullopt` to drop the setting from the config (and thus use the client's
     ///   default).
     void set_blinded_msgreqs(std::optional<bool> enabled);
+
+    bool accepts_protobuf() const override { return true; }
 };
 
 }  // namespace session::config

include/session/util.hpp

@@ -1,5 +1,8 @@
 #pragma once
+#include <sodium/randombytes.h>
+
 #include <cassert>
+#include <chrono>
 #include <cstring>
 #include <iterator>
 #include <memory>
@@ -39,6 +42,10 @@ inline std::string_view from_unsigned_sv(const std::vector<T, A>& v) {
     return {from_unsigned(v.data()), v.size()};
 }
 
+inline uint64_t get_timestamp() {
+    return std::chrono::steady_clock::now().time_since_epoch().count();
+}
+
 /// Returns true if the first string is equal to the second string, compared case-insensitively.
 inline bool string_iequal(std::string_view s1, std::string_view s2) {
     return std::equal(s1.begin(), s1.end(), s2.begin(), s2.end(), [](char a, char b) {

proto/CMakeLists.txt

@@ -0,0 +1,51 @@
+
+function(check_target target)
+    if (NOT TARGET ${target})
+        message(FATAL_ERROR "Project failed to compile required target: ${target}")
+    endif()
+endfunction()
+
+include(FetchContent)
+
+FetchContent_Declare(
+    protobuf
+    GIT_REPOSITORY  https://github.com/protocolbuffers/protobuf.git
+    GIT_TAG         v4.24.2     # apparently this must be a tag (not hash) for git_shallow to work?
+    GIT_SHALLOW     TRUE
+    GIT_PROGRESS    TRUE
+)
+
+set(protobuf_INSTALL OFF CACHE BOOL "" FORCE)
+set(protobuf_WITH_ZLIB OFF CACHE BOOL "" FORCE)
+set(protobuf_BUILD_TESTS OFF CACHE BOOL "" FORCE)
+set(protobuf_BUILD_EXAMPLES OFF CACHE BOOL "" FORCE)
+set(protobuf_BUILD_SHARED_LIBS OFF CACHE BOOL "" FORCE)
+set(protobuf_ABSL_PROVIDER "module" CACHE STRING "" FORCE)
+set(protobuf_BUILD_PROTOC_BINARIES ON CACHE BOOL "" FORCE)
+set(protobuf_BUILD_PROTOBUF_BINARIES ON CACHE BOOL "" FORCE)
+
+message(STATUS "Pulling protobuf repository...")
+
+FetchContent_MakeAvailable(protobuf)
+
+check_target(protobuf::libprotobuf-lite)
+check_target(protobuf::libprotobuf)
+check_target(protobuf::libprotoc)
+check_target(protobuf::protoc)
+
+set(Protobuf_INCLUDE_DIR "${protobuf_SOURCE_DIR}/src" CACHE INTERNAL "")
+set(Protobuf_LIBRARIES protobuf::libprotobuf CACHE INTERNAL "")
+find_package(Protobuf REQUIRED) # makes protobuf_generate_cpp available
+
+include_directories(${CMAKE_CURRENT_BINARY_DIR})
+
+add_library(protos protos.cpp)
+target_link_libraries(protos PUBLIC ${Protobuf_LIBRARIES} libsession::config)
+
+foreach(pfile SessionProtos WebSocketResources)
+    protobuf_generate_cpp(${pfile}_PROTO_SRCS ${pfile}_PROTO_HDRS ${pfile}.proto)
+    target_sources(protos PUBLIC ${${pfile}_PROTO_SRCS})
+endforeach()
+
+add_executable(test_proto test_proto.cpp)
+target_link_libraries(test_proto PUBLIC protos)