From: Christopher James Halse Rogers <christopher.halse.rog...@canonical.com>
Many languages such as C++ or Rust have an unwinding error-reporting
mechanism. Code in these languages can (and must!) wrap request handling
callbacks in unwind guards to avoid undefined behaviour.
As a consequence such code will detect internal server errors, but have
no way to communicate such failures to the client.
This adds a WL_DISPLAY_ERROR_INTERNAL error to wl_display so that
such code can notify (and disconnect) client which hit internal bugs.
Signed-off-by: Christopher James Halse Rogers
<christopher.halse.rog...@canonical.com>
---
protocol/wayland.xml | 2 ++
src/wayland-client.c | 3 +++
src/wayland-server-core.h | 4 ++++
src/wayland-server.c | 23 +++++++++++++++++++++++
tests/display-test.c | 40 ++++++++++++++++++++++++++++++++++++++++
5 files changed, 72 insertions(+)
diff --git a/protocol/wayland.xml b/protocol/wayland.xml
index b5662e0..1db31a6 100644
--- a/protocol/wayland.xml
+++ b/protocol/wayland.xml
@@ -94,6 +94,8 @@
summary="method doesn't exist on the specified interface"/>
<entry name="no_memory" value="2"
summary="server is out of memory"/>
+ <entry name="internal" value="3"
+ summary="internal server error"/>
</enum>
<event name="delete_id">
diff --git a/src/wayland-client.c b/src/wayland-client.c
index c1369b8..7c442b1 100644
--- a/src/wayland-client.c
+++ b/src/wayland-client.c
@@ -192,6 +192,9 @@ display_protocol_error(struct wl_display *display, uint32_t
code,
case WL_DISPLAY_ERROR_NO_MEMORY:
err = ENOMEM;
break;
+ case WL_DISPLAY_ERROR_INTERNAL:
+ err = EPROTO;
+ break;
default:
err = EFAULT;
}
diff --git a/src/wayland-server-core.h b/src/wayland-server-core.h
index 2e725d9..7137da6 100644
--- a/src/wayland-server-core.h
+++ b/src/wayland-server-core.h
@@ -324,6 +324,10 @@ wl_client_get_object(struct wl_client *client, uint32_t
id);
void
wl_client_post_no_memory(struct wl_client *client);
+void
+wl_client_post_internal_error(struct wl_client *client,
+ const char* msg, ...) WL_PRINTF(2,3);
+
void
wl_client_add_resource_created_listener(struct wl_client *client,
struct wl_listener *listener);
diff --git a/src/wayland-server.c b/src/wayland-server.c
index 00c93f7..6317f8f 100644
--- a/src/wayland-server.c
+++ b/src/wayland-server.c
@@ -650,6 +650,29 @@ wl_client_post_no_memory(struct wl_client *client)
WL_DISPLAY_ERROR_NO_MEMORY, "no memory");
}
+/** Report an internal server error
+ *
+ * \param client The client object
+ * \param msg A printf-style format string
+ * \param ... Format string arguments
+ *
+ * Report an unspecified internal error and disconnect the client.
+ *
+ * \memberof wl_client
+ */
+WL_EXPORT void
+wl_client_post_internal_error(struct wl_client *client,
+ char const *msg, ...)
+{
+ va_list ap;
+
+ va_start(ap, msg);
+ wl_resource_post_error_vargs(client->display_resource,
+ WL_DISPLAY_ERROR_INTERNAL,
+ msg, ap);
+ va_end(ap);
+}
+
WL_EXPORT void
wl_resource_post_no_memory(struct wl_resource *resource)
{
diff --git a/tests/display-test.c b/tests/display-test.c
index 9b49a0e..63f8b5a 100644
--- a/tests/display-test.c
+++ b/tests/display-test.c
@@ -419,6 +419,46 @@ TEST(post_nomem_tst)
display_destroy(d);
}
+static void
+post_internal_error_main(void)
+{
+ struct client *c = client_connect();
+ struct wl_seat *seat = client_get_seat(c);
+ uint32_t object_id, protocol_error;
+ const struct wl_interface *interface;
+
+ assert(stop_display(c, 1) == -1);
+ int err = wl_display_get_error(c->wl_display);
+ fprintf(stderr, "Err is %i\n", err);
+ assert(err == EPROTO);
+ protocol_error = wl_display_get_protocol_error(c->wl_display,
+ &interface,
+ &object_id);
+ assert(protocol_error == WL_DISPLAY_ERROR_INTERNAL);
+ assert(interface == &wl_display_interface);
+
+ wl_proxy_destroy((struct wl_proxy *) seat);
+ client_disconnect_nocheck(c);
+}
+
+TEST(post_internal_error_tst)
+{
+ struct display *d = display_create();
+ struct client_info *cl;
+
+ wl_global_create(d->wl_display, &wl_seat_interface,
+ 1, d, bind_seat);
+
+ cl = client_create_noarg(d, post_internal_error_main);
+ display_run(d);
+
+ wl_client_post_internal_error(cl->wl_client, "Error %i", 20);
+
+ display_resume(d);
+
+ display_destroy(d);
+}
+
static void
register_reading(struct wl_display *display)
{
--
2.15.1
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