sbus: Refactor how we export DBus interfaces

Most importantly, stop using per connection private data. This doesn't
scale when you have more than one thing exporting or exported on a
connection.

Remove struct sbus_interface and expand sbus_conn_add_interface()
function. Remove various struct sbus_interface args to connection
initialization functions and make callers use sbus_conn_add_interface()
directly. The old method was optimized for exporting one interface
on a connection. We'll have connections that export zero, one or more
interfaces.

To export an interface on a DBus server, call sbus_conn_add_interface()
from within the sbus_server_conn_init_fn. To export an interface on
a DBus client, call sbus_conn_add_interface() after sbus_new_connection()
returns.

As before struct sbus_interface represents an object exported via DBus.
However it is now talloc allocated. One can set instance data on the
struct sbus_interface. This instance data is passed to the various
handlers and used in their implementation.

However, we now have type safe interface exporting in the various
high level sss_process_init() sss_monitor_init() and so on.

Introspection support was not in use, and is now gone until we
implement it using the metadata (future patch).

Reviewed-by: Jakub Hrozek <jhrozek@redhat.com>
Reviewed-by: Pavel Březina <pbrezina@redhat.com>
Reviewed-by: Lukáš Slebodník <lslebodn@redhat.com>

3 files changed, 28 insertions, 23 deletions

diff --git a/src/monitor/monitor.c b/src/monitor/monitor.c
index 2e0f5230f..9470075b5 100644
--- a/src/monitor/monitor.c
+++ b/src/monitor/monitor.c
@@ -217,7 +217,7 @@ static void network_status_change_cb(void *cb_data)
 
 /* dbus_get_monitor_version
  * Return the monitor version over D-BUS */
-static int get_monitor_version(struct sbus_request *dbus_req)
+static int get_monitor_version(struct sbus_request *dbus_req, void *data)
 {
     dbus_uint16_t version = MONITOR_VERSION;
 
@@ -236,19 +236,17 @@ static int add_svc_conn_spy(struct mt_svc *svc);
 
 /* registers a new client.
  * if operation is successful also sends back the Monitor version */
-static int client_registration(struct sbus_request *dbus_req)
+static int client_registration(struct sbus_request *dbus_req, void *data)
 {
     dbus_uint16_t version = MONITOR_VERSION;
     struct mon_init_conn *mini;
     struct mt_svc *svc;
-    void *data;
     DBusError dbus_error;
     dbus_uint16_t svc_ver;
     char *svc_name;
     dbus_bool_t dbret;
     int ret;
 
-    data = sbus_conn_get_private_data(dbus_req->conn);
     mini = talloc_get_type(data, struct mon_init_conn);
     if (!mini) {
         DEBUG(SSSDBG_FATAL_FAILURE, "Connection holds no valid init data\n");
@@ -503,12 +501,6 @@ struct mon_srv_iface monitor_methods = {
     .RegisterService = client_registration,
 };
 
-struct sbus_interface monitor_server_interface = {
-    MON_SRV_PATH,
-    &monitor_methods.vtable,
-    NULL
-};
-
 /* monitor_dbus_init
  * Set up the monitor service as a D-BUS Server */
 static int monitor_dbus_init(struct mt_ctx *ctx)
@@ -521,8 +513,7 @@ static int monitor_dbus_init(struct mt_ctx *ctx)
         return ret;
     }
 
-    ret = sbus_new_server(ctx, ctx->ev,
-                          monitor_address, &monitor_server_interface,
+    ret = sbus_new_server(ctx, ctx->ev, monitor_address,
                           false, &ctx->sbus_srv, monitor_service_init, ctx);
 
     talloc_free(monitor_address);
@@ -2309,6 +2300,7 @@ static void init_timeout(struct tevent_context *ev,
  */
 static int monitor_service_init(struct sbus_connection *conn, void *data)
 {
+    struct sbus_interface *intf;
     struct mt_ctx *ctx;
     struct mon_init_conn *mini;
     struct timeval tv;
@@ -2336,9 +2328,12 @@ static int monitor_service_init(struct sbus_connection *conn, void *data)
         return ENOMEM;
     }
 
-    sbus_conn_set_private_data(conn, mini);
+    intf = sbus_new_interface(conn, MON_SRV_PATH, &monitor_methods.vtable, mini);
+    if (!intf) {
+        return ENOMEM;
+    }
 
-    return EOK;
+    return sbus_conn_add_interface(conn, intf);
 }
 
 /* service_send_ping
diff --git a/src/monitor/monitor_interfaces.h b/src/monitor/monitor_interfaces.h
index 2970251df..c015fbc66 100644
--- a/src/monitor/monitor_interfaces.h
+++ b/src/monitor/monitor_interfaces.h
@@ -38,14 +38,14 @@
 int monitor_get_sbus_address(TALLOC_CTX *mem_ctx, char **address);
 int monitor_common_send_id(struct sbus_connection *conn,
                            const char *name, uint16_t version);
-int monitor_common_pong(struct sbus_request *dbus_req);
-int monitor_common_res_init(struct sbus_request *dbus_req);
+int monitor_common_pong(struct sbus_request *dbus_req, void *data);
+int monitor_common_res_init(struct sbus_request *dbus_req, void *data);
 int monitor_common_rotate_logs(struct confdb_ctx *confdb,
                                const char *conf_entry);
 
 errno_t sss_monitor_init(TALLOC_CTX *mem_ctx,
                          struct tevent_context *ev,
-                         struct sbus_interface *intf,
+                         struct mon_cli_iface *mon_iface,
                          const char *svc_name,
                          uint16_t svc_version,
                          void *pvt,
diff --git a/src/monitor/monitor_sbus.c b/src/monitor/monitor_sbus.c
index 92d483233..544407ca2 100644
--- a/src/monitor/monitor_sbus.c
+++ b/src/monitor/monitor_sbus.c
@@ -144,12 +144,12 @@ int monitor_common_send_id(struct sbus_connection *conn,
     return retval;
 }
 
-int monitor_common_pong(struct sbus_request *dbus_req)
+int monitor_common_pong(struct sbus_request *dbus_req, void *data)
 {
     return sbus_request_return_and_finish(dbus_req, DBUS_TYPE_INVALID);
 }
 
-int monitor_common_res_init(struct sbus_request *dbus_req)
+int monitor_common_res_init(struct sbus_request *dbus_req, void *data)
 {
     int ret;
 
@@ -198,7 +198,7 @@ errno_t monitor_common_rotate_logs(struct confdb_ctx *confdb,
 
 errno_t sss_monitor_init(TALLOC_CTX *mem_ctx,
                          struct tevent_context *ev,
-                         struct sbus_interface *intf,
+                         struct mon_cli_iface *mon_iface,
                          const char *svc_name,
                          uint16_t svc_version,
                          void *pvt,
@@ -206,6 +206,7 @@ errno_t sss_monitor_init(TALLOC_CTX *mem_ctx,
 {
     errno_t ret;
     char *sbus_address;
+    struct sbus_interface *intf;
     struct sbus_connection *conn;
 
     /* Set up SBUS connection to the monitor */
@@ -215,9 +216,7 @@ errno_t sss_monitor_init(TALLOC_CTX *mem_ctx,
         return ret;
     }
 
-    ret = sbus_client_init(mem_ctx, ev, sbus_address,
-                           intf, &conn,
-                           NULL, pvt);
+    ret = sbus_client_init(mem_ctx, ev, sbus_address, &conn);
     if (ret != EOK) {
         DEBUG(SSSDBG_FATAL_FAILURE, "Failed to connect to monitor services.\n");
         talloc_free(sbus_address);
@@ -225,6 +224,17 @@ errno_t sss_monitor_init(TALLOC_CTX *mem_ctx,
     }
     talloc_free(sbus_address);
 
+    intf = sbus_new_interface(mem_ctx, MONITOR_PATH, &mon_iface->vtable, pvt);
+    if (!intf) {
+        ret = ENOMEM;
+    } else {
+        ret = sbus_conn_add_interface(conn, intf);
+    }
+    if (ret != EOK) {
+        DEBUG(SSSDBG_FATAL_FAILURE, "Failed to export monitor client.\n");
+        return ret;
+    }
+
     /* Identify ourselves to the monitor */
     ret = monitor_common_send_id(conn, svc_name, svc_version);
     if (ret != EOK) {