Create dynamic libraries with C interfaces for Dart FFI

3rd-party/CMakeLists.txt

@@ -86,6 +86,7 @@ option(YAML_CPP_BUILD_CONTRIB OFF)
 option(YAML_CPP_BUILD_TESTS OFF)
 
 add_subdirectory(yaml-cpp EXCLUDE_FROM_ALL)
+set_target_properties(yaml-cpp PROPERTIES POSITION_INDEPENDENT_CODE ON)
 
 add_library(yaml INTERFACE)
 
@@ -121,6 +122,7 @@ set(BUILD_SHARED_LIBS OFF)
 add_subdirectory(semver EXCLUDE_FROM_ALL)
 target_include_directories(semver INTERFACE
   ${CMAKE_CURRENT_SOURCE_DIR}/semver/include)
+set_target_properties(semver PROPERTIES POSITION_INDEPENDENT_CODE ON)
 
 # xz-decoder config
 add_subdirectory(xz-decoder EXCLUDE_FROM_ALL)

include/multipass/cli/client_common.h

@@ -67,9 +67,9 @@ namespace client
 {
 QString persistent_settings_filename();
 void register_global_settings_handlers();
-std::shared_ptr<grpc::Channel> make_channel(const std::string& server_address, CertProvider* cert_provider);
+std::shared_ptr<grpc::Channel> make_channel(const std::string& server_address, const CertProvider& cert_provider);
 std::string get_server_address();
-std::unique_ptr<SSLCertProvider> get_cert_provider();
+std::unique_ptr<SSLCertProvider> get_cert_provider(const std::string& server_address);
 void set_logger();
 void set_logger(multipass::logging::Level verbosity); // full param qualification makes sure msvc is happy
 void pre_setup();

include/multipass/dart_ffi.h

@@ -0,0 +1,18 @@
+#ifndef MULTIPASS_DART_FFI_H
+#define MULTIPASS_DART_FFI_H
+
+extern "C" const char* multipass_version();
+
+extern "C" const char* generate_petname();
+
+extern "C" const char* get_server_address();
+
+extern "C" struct KeyCertificatePair
+{
+    const char* pem_cert;
+    const char* pem_priv_key;
+};
+
+extern "C" struct KeyCertificatePair get_cert_pair();
+
+#endif // MULTIPASS_DART_FFI_H

src/client/cli/client.cpp

@@ -74,7 +74,7 @@ auto make_handler_unregisterer(mp::SettingsHandler* handler)
 } // namespace
 
 mp::Client::Client(ClientConfig& config)
-    : stub{mp::Rpc::NewStub(mp::client::make_channel(config.server_address, config.cert_provider.get()))},
+    : stub{mp::Rpc::NewStub(mp::client::make_channel(config.server_address, *config.cert_provider))},
       term{config.term},
       aliases{config.term}
 {

src/client/cli/main.cpp

@@ -38,7 +38,9 @@ int main_impl(int argc, char* argv[])
 
     mp::client::register_global_settings_handlers();
 
-    mp::ClientConfig config{mp::client::get_server_address(), mp::client::get_cert_provider(), term.get()};
+    auto server_address = mp::client::get_server_address();
+    mp::ClientConfig config{mp::client::get_server_address(), mp::client::get_cert_provider(server_address),
+                            term.get()};
     mp::Client client{config};
 
     return client.run(QCoreApplication::arguments());

src/client/common/client_common.cpp

@@ -78,9 +78,8 @@ std::string message_box(const std::string& message)
     return '\n' + divider + '\n' + message + '\n' + divider + '\n';
 }
 
-grpc::SslCredentialsOptions get_ssl_credentials_opts_from(const QString& cert_dir_path)
+grpc::SslCredentialsOptions get_ssl_credentials_opts_from(const mp::CertProvider& cert_provider)
 {
-    mp::SSLCertProvider cert_provider{cert_dir_path};
     auto opts = grpc::SslCredentialsOptions();
 
     opts.server_certificate_request = GRPC_SSL_REQUEST_SERVER_CERTIFICATE_BUT_DONT_VERIFY;
@@ -191,51 +190,9 @@ void mp::client::register_global_settings_handlers()
 }
 
 std::shared_ptr<grpc::Channel> mp::client::make_channel(const std::string& server_address,
-                                                        mp::CertProvider* cert_provider)
+                                                        const mp::CertProvider& cert_provider)
 {
-    // No common client certificates exist yet.
-    // TODO: Remove the following logic when we are comfortable all installed clients are using the common cert
-    if (!cert_provider)
-    {
-        auto data_location{MP_STDPATHS.writableLocation(StandardPaths::GenericDataLocation)};
-        auto common_client_cert_dir_path{data_location + common_client_cert_dir};
-
-        // The following logic is for determing which certificate to use when the client starts up.
-        // 1. Check if the multipass-gui certificate exists and determine if it's authenticated
-        //    with the daemon already.  If it is, copy it to the common client certificate directory and use it.
-        // 2. If that fails, then try the certificate from the cli client in the same manner.
-        // 3. Delete any per-client certificate dirs.
-        // 4. Lastly, no known certificate for the user exists, so create a new common certificate and use that.
-
-        const std::vector<QString> cert_dirs{data_location + gui_client_cert_dir, data_location + cli_client_cert_dir};
-        for (const auto& cert_dir : cert_dirs)
-        {
-            if (client_certs_exist(cert_dir))
-            {
-                if (auto rpc_channel{
-                        create_channel_and_validate(server_address, get_ssl_credentials_opts_from(cert_dir))})
-                {
-                    copy_client_certs_to_common_dir(cert_dir, common_client_cert_dir_path);
-                    mp::utils::remove_directories(cert_dirs);
-
-                    return rpc_channel;
-                }
-            }
-        }
-
-        mp::utils::remove_directories(cert_dirs);
-        MP_UTILS.make_dir(common_client_cert_dir_path);
-
-        return grpc::CreateChannel(server_address,
-                                   grpc::SslCredentials(get_ssl_credentials_opts_from(common_client_cert_dir_path)));
-    }
-
-    auto opts = grpc::SslCredentialsOptions();
-    opts.server_certificate_request = GRPC_SSL_REQUEST_SERVER_CERTIFICATE_BUT_DONT_VERIFY;
-    opts.pem_cert_chain = cert_provider->PEM_certificate();
-    opts.pem_private_key = cert_provider->PEM_signing_key();
-
-    return grpc::CreateChannel(server_address, grpc::SslCredentials(opts));
+    return grpc::CreateChannel(server_address, grpc::SslCredentials(get_ssl_credentials_opts_from(cert_provider)));
 }
 
 std::string mp::client::get_server_address()
@@ -250,17 +207,46 @@ std::string mp::client::get_server_address()
     return mp::platform::default_server_address();
 }
 
-std::unique_ptr<mp::SSLCertProvider> mp::client::get_cert_provider()
+std::unique_ptr<mp::SSLCertProvider> mp::client::get_cert_provider(const std::string& server_address)
 {
     auto data_location{MP_STDPATHS.writableLocation(StandardPaths::GenericDataLocation)};
     auto common_client_cert_dir_path{data_location + common_client_cert_dir};
 
     if (client_certs_exist(common_client_cert_dir_path))
     {
-        return std::make_unique<mp::SSLCertProvider>(common_client_cert_dir_path);
+        return std::make_unique<SSLCertProvider>(common_client_cert_dir_path);
+    }
+
+    // No common client certificates exist yet.
+    // TODO: Remove the following logic when we are comfortable all installed clients are using the common cert
+
+    // The following logic is for determining which certificate to use when the client starts up.
+    // 1. Check if the multipass-gui certificate exists and determine if it's authenticated
+    //    with the daemon already.  If it is, copy it to the common client certificate directory and use it.
+    // 2. If that fails, then try the certificate from the cli client in the same manner.
+    // 3. Delete any per-client certificate dirs.
+    // 4. Lastly, no known certificate for the user exists, so create a new common certificate and use that.
+
+    const std::vector<QString> cert_dirs{data_location + gui_client_cert_dir, data_location + cli_client_cert_dir};
+    for (const auto& cert_dir : cert_dirs)
+    {
+        if (client_certs_exist(cert_dir))
+        {
+            auto ssl_cert_provider = std::make_unique<SSLCertProvider>(cert_dir);
+            if (auto rpc_channel{
+                    create_channel_and_validate(server_address, get_ssl_credentials_opts_from(*ssl_cert_provider))})
+            {
+                copy_client_certs_to_common_dir(cert_dir, common_client_cert_dir_path);
+                utils::remove_directories(cert_dirs);
+
+                return ssl_cert_provider;
+            }
+        }
     }
 
-    return nullptr;
+    utils::remove_directories(cert_dirs);
+    MP_UTILS.make_dir(common_client_cert_dir_path);
+    return std::make_unique<SSLCertProvider>(common_client_cert_dir_path);
 }
 
 void mp::client::set_logger()

src/client/desktop_gui/CMakeLists.txt

@@ -21,3 +21,12 @@ if(MULTIPASS_ENABLE_FLUTTER_GUI)
 
   include("CMakeLists.txt.linux")
 endif()
+
+add_library(dart_ffi SHARED ffi/dart_ffi.cpp)
+
+target_link_libraries(dart_ffi
+  petname
+  client_common
+)
+
+install(TARGETS dart_ffi LIBRARY COMPONENT multipass)

src/client/desktop_gui/ffi/dart_ffi.cpp

@@ -0,0 +1,76 @@
+#include "multipass/dart_ffi.h"
+#include "multipass/cli/client_common.h"
+#include "multipass/format.h"
+#include "multipass/logging/log.h"
+#include "multipass/name_generator.h"
+#include "multipass/version.h"
+
+namespace mp = multipass;
+namespace mpc = multipass::client;
+namespace mpl = multipass::logging;
+
+constexpr auto category = "dart-ffi";
+
+extern "C" const char* multipass_version()
+{
+    return mp::version_string;
+}
+
+extern "C" const char* generate_petname()
+try
+{
+    static mp::NameGenerator::UPtr generator = mp::make_default_name_generator();
+    const auto name = generator->make_name();
+    return strdup(name.c_str());
+}
+catch (const std::exception& e)
+{
+    mpl::log(mpl::Level::warning, category, fmt::format("failed generating petname: {}", e.what()));
+    return nullptr;
+}
+catch (...)
+{
+    mpl::log(mpl::Level::warning, category, "failed generating petname");
+    return nullptr;
+}
+
+extern "C" const char* get_server_address()
+try
+{
+    const auto address = mpc::get_server_address();
+    return strdup(address.c_str());
+}
+catch (const std::exception& e)
+{
+    mpl::log(mpl::Level::warning, category, fmt::format("failed retrieving server address: {}", e.what()));
+    return nullptr;
+}
+catch (...)
+{
+    mpl::log(mpl::Level::warning, category, "failed retrieving server address");
+    return nullptr;
+}
+
+extern "C" struct KeyCertificatePair get_cert_pair()
+try
+{
+    const auto provider = mpc::get_cert_provider(mpc::get_server_address());
+    const auto cert = provider->PEM_certificate();
+    const auto key = provider->PEM_signing_key();
+    struct KeyCertificatePair pair
+    {
+    };
+    pair.pem_cert = strdup(cert.c_str());
+    pair.pem_priv_key = strdup(key.c_str());
+    return pair;
+}
+catch (const std::exception& e)
+{
+    mpl::log(mpl::Level::warning, category, fmt::format("failed retrieving certificate key pair: {}", e.what()));
+    return KeyCertificatePair{nullptr, nullptr};
+}
+catch (...)
+{
+    mpl::log(mpl::Level::warning, category, "failed retrieving certificate key pair");
+    return KeyCertificatePair{nullptr, nullptr};
+}

src/client/gui/client_gui.cpp

@@ -27,7 +27,7 @@ namespace mp = multipass;
 namespace mpl = multipass::logging;
 
 mp::ClientGui::ClientGui(ClientConfig& config)
-    : stub{mp::Rpc::NewStub(mp::client::make_channel(config.server_address, config.cert_provider.get()))},
+    : stub{mp::Rpc::NewStub(mp::client::make_channel(config.server_address, *config.cert_provider))},
       gui_cmd{std::make_unique<cmd::GuiCmd>(*stub, null_stream, null_stream)}
 {
 }

src/client/gui/main.cpp

@@ -36,7 +36,8 @@ int main_impl(int argc, char* argv[])
 
     mp::client::register_global_settings_handlers();
 
-    mp::ClientConfig config{mp::client::get_server_address(), mp::client::get_cert_provider()};
+    auto server_address = mp::client::get_server_address();
+    mp::ClientConfig config{server_address, mp::client::get_cert_provider(server_address)};
     mp::ClientGui client{config};
 
     return client.run(app.arguments());

tests/mock_cert_provider.h

@@ -62,12 +62,12 @@ struct MockCertProvider : public CertProvider
 {
     MockCertProvider()
     {
-        EXPECT_CALL(*this, PEM_certificate()).WillRepeatedly(Return(client_cert));
-        EXPECT_CALL(*this, PEM_signing_key()).WillRepeatedly(Return(client_key));
+        ON_CALL(*this, PEM_certificate).WillByDefault(Return(client_cert));
+        ON_CALL(*this, PEM_signing_key).WillByDefault(Return(client_key));
     }
 
-    MOCK_METHOD(std::string, PEM_certificate, (), (const, override));
-    MOCK_METHOD(std::string, PEM_signing_key, (), (const, override));
+    MOCK_METHOD(std::string, PEM_certificate, (), (override, const));
+    MOCK_METHOD(std::string, PEM_signing_key, (), (override, const));
 };
 } // namespace multipass::test
 #endif // MULTIPASS_MOCK_CERT_PROVIDER_H

tests/test_cli_client.cpp

@@ -155,9 +155,6 @@ struct Client : public Test
             .Times(AnyNumber())
             .WillRepeatedly(Return("")); /* Avoid writing to Windows Terminal settings. We use an "expectation" so that
                                             it gets reset at the end of each test (by VerifyAndClearExpectations) */
-
-        EXPECT_CALL(*client_cert_provider, PEM_certificate()).WillOnce(Return(mpt::client_cert));
-        EXPECT_CALL(*client_cert_provider, PEM_signing_key()).WillOnce(Return(mpt::client_key));
     }
 
     void TearDown() override
@@ -171,7 +168,7 @@ struct Client : public Test
 
     int setup_client_and_run(const std::vector<std::string>& command, mp::Terminal& term)
     {
-        mp::ClientConfig client_config{server_address, std::move(client_cert_provider), &term};
+        mp::ClientConfig client_config{server_address, get_client_cert_provider(), &term};
         mp::Client client{client_config};
         QStringList args = QStringList() << "multipass_test";
 
@@ -359,7 +356,10 @@ struct Client : public Test
 #else
     std::string server_address{"unix:/tmp/test-multipassd.socket"};
 #endif
-    std::unique_ptr<mpt::MockCertProvider> client_cert_provider{std::make_unique<mpt::MockCertProvider>()};
+    static std::unique_ptr<mpt::MockCertProvider> get_client_cert_provider()
+    {
+        return std::make_unique<mpt::MockCertProvider>();
+    };
     std::unique_ptr<mpt::MockCertProvider> daemon_cert_provider{std::make_unique<mpt::MockCertProvider>()};
     mpt::MockPlatform::GuardedMock attr{mpt::MockPlatform::inject<NiceMock>()};
     mpt::MockPlatform* mock_platform = attr.first;

tests/test_client_common.cpp

@@ -73,7 +73,7 @@ TEST_F(TestClientCommon, usesCommonCertWhenItExists)
     mpt::make_file_with_content(common_client_cert_file, mpt::client_cert);
     mpt::make_file_with_content(common_client_key_file, mpt::client_key);
 
-    EXPECT_TRUE(mp::client::make_channel(server_address, mp::client::get_cert_provider().get()));
+    EXPECT_TRUE(mp::client::make_channel(server_address, *mp::client::get_cert_provider(server_address)));
 }
 
 TEST_F(TestClientCommon, usesExistingGuiCert)
@@ -88,7 +88,7 @@ TEST_F(TestClientCommon, usesExistingGuiCert)
 
     mpt::MockDaemon daemon{make_secure_server()};
 
-    EXPECT_TRUE(mp::client::make_channel(server_address, mp::client::get_cert_provider().get()));
+    EXPECT_TRUE(mp::client::make_channel(server_address, *mp::client::get_cert_provider(server_address)));
     EXPECT_FALSE(QFile::exists(gui_cert_dir));
 }
 
@@ -113,7 +113,7 @@ TEST_F(TestClientCommon, failsGuiCertUsesExistingCliCert)
 
     mpt::MockDaemon daemon{make_secure_server()};
 
-    EXPECT_TRUE(mp::client::make_channel(server_address, mp::client::get_cert_provider().get()));
+    EXPECT_TRUE(mp::client::make_channel(server_address, *mp::client::get_cert_provider(server_address)));
     EXPECT_FALSE(QFile::exists(gui_cert_dir));
     EXPECT_FALSE(QFile::exists(cli_cert_dir));
 }
@@ -139,7 +139,7 @@ TEST_F(TestClientCommon, noValidCertsCreatesNewCommonCert)
 
     mpt::MockDaemon daemon{make_secure_server()};
 
-    EXPECT_TRUE(mp::client::make_channel(server_address, mp::client::get_cert_provider().get()));
+    EXPECT_TRUE(mp::client::make_channel(server_address, *mp::client::get_cert_provider(server_address)));
     EXPECT_TRUE(QFile::exists(common_cert_dir + "/" + mp::client_cert_file));
     EXPECT_TRUE(QFile::exists(common_cert_dir + "/" + mp::client_key_file));
     EXPECT_FALSE(QFile::exists(gui_cert_dir));