When a new device appears to ADB, prompt the user whether or not to allow the connection.

Approved by: PS Jenkins bot, Charles Kerr, Xavi Garcia

1 files changed, 250 insertions, 0 deletions

diff --git a/src/usb-snap.cpp b/src/usb-snap.cpp
new file mode 100644
index 0000000..ba964fb
--- /dev/null
+++ b/src/usb-snap.cpp
@@ -0,0 +1,250 @@
+/*
+ * Copyright 2016 Canonical Ltd.
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 3, as published
+ * by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranties of
+ * MERCHANTABILITY, SATISFACTORY QUALITY, or FITNESS FOR A PARTICULAR
+ * PURPOSE.  See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors:
+ *   Charles Kerr <charles.kerr@canonical.com>
+ */
+
+#include <src/dbus-names.h>
+#include <src/usb-snap.h>
+
+#include <glib/gi18n.h>
+#include <gio/gio.h>
+
+/***
+****
+***/
+
+class UsbSnap::Impl
+{
+public:
+
+    explicit Impl(const std::string& fingerprint):
+        m_fingerprint{fingerprint},
+        m_cancellable{g_cancellable_new()}
+    {
+        g_bus_get (G_BUS_TYPE_SESSION, m_cancellable, on_bus_ready_static, this);
+    }
+
+    ~Impl()
+    {
+        g_cancellable_cancel(m_cancellable);
+        g_clear_object(&m_cancellable);
+
+        if (m_subscription_id != 0)
+            g_dbus_connection_signal_unsubscribe (m_bus, m_subscription_id);
+
+        if (m_notification_id != 0) {
+            GError* error {};
+            g_dbus_connection_call_sync(m_bus,
+                                        DBusNames::Notify::NAME,
+                                        DBusNames::Notify::PATH,
+                                        DBusNames::Notify::INTERFACE,
+                                        "CloseNotification",
+                                        g_variant_new("(u)", m_notification_id),
+                                        nullptr,
+                                        G_DBUS_CALL_FLAGS_NONE,
+                                        -1,
+                                        nullptr,
+                                        &error);
+            if (error != nullptr) {
+                g_warning("Error closing notification: %s", error->message);
+                g_clear_error(&error);
+            }
+        }
+
+        g_clear_object(&m_bus);
+    }
+
+    core::Signal<AdbdClient::PKResponse,bool>& on_user_response()
+    {
+        return m_on_user_response;
+    }
+
+private:
+
+    static void on_bus_ready_static(GObject* /*source*/, GAsyncResult* res, gpointer gself)
+    {
+        GError* error {};
+        auto bus = g_bus_get_finish (res, &error);
+        if (error != nullptr) {
+            if (!g_error_matches(error, G_IO_ERROR, G_IO_ERROR_CANCELLED))
+                g_warning("UsbSnap: Error getting session bus: %s", error->message);
+            g_clear_error(&error);
+        } else {
+            static_cast<Impl*>(gself)->on_bus_ready(bus);
+        }
+        g_clear_object(&bus);
+    }
+
+    void on_bus_ready(GDBusConnection* bus)
+    {
+        m_bus = G_DBUS_CONNECTION(g_object_ref(G_OBJECT(bus)));
+
+        m_subscription_id = g_dbus_connection_signal_subscribe(m_bus,
+                                                               DBusNames::Notify::NAME,
+                                                               DBusNames::Notify::INTERFACE,
+                                                               nullptr,
+                                                               DBusNames::Notify::PATH,
+                                                               nullptr,
+                                                               G_DBUS_SIGNAL_FLAGS_NONE,
+                                                               on_notification_signal_static,
+                                                               this,
+                                                               nullptr);
+
+        auto body = g_strdup_printf(_("The computer's RSA key fingerprint is: %s"), m_fingerprint.c_str());
+
+        GVariantBuilder actions_builder;
+        g_variant_builder_init(&actions_builder, G_VARIANT_TYPE_STRING_ARRAY);
+        g_variant_builder_add(&actions_builder, "s", ACTION_ALLOW);
+        g_variant_builder_add(&actions_builder, "s", _("Allow"));
+        g_variant_builder_add(&actions_builder, "s", ACTION_DENY);
+        g_variant_builder_add(&actions_builder, "s", _("Don't Allow"));
+
+        GVariantBuilder hints_builder;
+        g_variant_builder_init(&hints_builder, G_VARIANT_TYPE_VARDICT);
+        g_variant_builder_add(&hints_builder, "{sv}", "x-canonical-non-shaped-icon", g_variant_new_string("true"));
+        g_variant_builder_add(&hints_builder, "{sv}", "x-canonical-snap-decisions", g_variant_new_string("true"));
+        g_variant_builder_add(&hints_builder, "{sv}", "x-canonical-private-affirmative-tint", g_variant_new_string("true"));
+
+        auto args = g_variant_new("(susssasa{sv}i)",
+                                  "",
+                                  uint32_t(0),
+                                  "computer-symbolic",
+                                  _("Allow USB Debugging?"),
+                                  body,
+                                  &actions_builder,
+                                  &hints_builder,
+                                  -1);
+        g_dbus_connection_call(m_bus,
+                               DBusNames::Notify::NAME,
+                               DBusNames::Notify::PATH,
+                               DBusNames::Notify::INTERFACE,
+                               "Notify",
+                               args,
+                               G_VARIANT_TYPE("(u)"),
+                               G_DBUS_CALL_FLAGS_NONE,
+                               -1, // timeout
+                               m_cancellable,
+                               on_notify_reply_static,
+                               this);
+
+        g_clear_pointer(&body, g_free);
+    }
+
+    static void on_notify_reply_static(GObject* obus, GAsyncResult* res, gpointer gself)
+    {
+        GError* error {};
+        auto reply = g_dbus_connection_call_finish (G_DBUS_CONNECTION(obus), res, &error);
+        if (error != nullptr) {
+            if (!g_error_matches(error, G_IO_ERROR, G_IO_ERROR_CANCELLED))
+                g_warning("UsbSnap: Error calling Notify: %s", error->message);
+            g_clear_error(&error);
+        } else {
+            uint32_t id {};
+            g_variant_get(reply, "(u)", &id);
+            static_cast<Impl*>(gself)->on_notify_reply(id);
+        }
+        g_clear_pointer(&reply, g_variant_unref);
+    }
+
+    void on_notify_reply(uint32_t id)
+    {
+        m_notification_id = id;
+    }
+
+    static void on_notification_signal_static(GDBusConnection* /*connection*/,
+                                              const gchar* /*sender_name*/,
+                                              const gchar* object_path,
+                                              const gchar* interface_name,
+                                              const gchar* signal_name,
+                                              GVariant* parameters,
+                                              gpointer gself)
+    {
+        g_return_if_fail(!g_strcmp0(object_path, DBusNames::Notify::PATH));
+        g_return_if_fail(!g_strcmp0(interface_name, DBusNames::Notify::INTERFACE));
+
+        auto self = static_cast<Impl*>(gself);
+
+        if (!g_strcmp0(signal_name, DBusNames::Notify::ActionInvoked::NAME))
+        {
+            uint32_t id {};
+            const char* action_name {};
+            g_variant_get(parameters, "(u&s)", &id, &action_name);
+            if (id == self->m_notification_id)
+                self->on_action_invoked(action_name);
+        }
+        else if (!g_strcmp0(signal_name, DBusNames::Notify::NotificationClosed::NAME))
+        {
+            uint32_t id {};
+            uint32_t close_reason {};
+            g_variant_get(parameters, "(uu)", &id, &close_reason);
+            if (id == self->m_notification_id)
+                self->on_notification_closed(close_reason);
+        }
+    }
+
+    void on_action_invoked(const char* action_name)
+    {
+        const auto response = !g_strcmp0(action_name, ACTION_ALLOW)
+            ? AdbdClient::PKResponse::ALLOW
+            : AdbdClient::PKResponse::DENY;
+
+        // FIXME: the current default is to cover the most common use case.
+        // We need to get the notification ui's checkbox working ASAP so
+        // that the user can provide this flag
+        const bool remember_this_choice = response == AdbdClient::PKResponse::ALLOW;
+
+        m_on_user_response(response, remember_this_choice);
+    }
+
+    void on_notification_closed(uint32_t close_reason)
+    {
+        if (close_reason == DBusNames::Notify::NotificationClosed::Reason::EXPIRED)
+            m_on_user_response(AdbdClient::PKResponse::DENY, false);
+
+        m_notification_id = 0;
+    }
+
+    static constexpr char const * ACTION_ALLOW {"allow"};
+    static constexpr char const * ACTION_DENY  {"deny"};
+
+    const std::string m_fingerprint;
+    core::Signal<AdbdClient::PKResponse,bool> m_on_user_response;
+    GCancellable* m_cancellable {};
+    GDBusConnection* m_bus {};
+    uint32_t m_notification_id {};
+    unsigned int m_subscription_id {};
+};
+
+/***
+****
+***/
+
+UsbSnap::UsbSnap(const std::string& public_key):
+    impl{new Impl{public_key}}
+{
+}
+
+UsbSnap::~UsbSnap()
+{
+}
+
+core::Signal<AdbdClient::PKResponse,bool>&
+UsbSnap::on_user_response()
+{
+    return impl->on_user_response();
+}
+