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>

2 files changed, 24 insertions, 30 deletions

diff --git a/src/providers/proxy/proxy_child.c b/src/providers/proxy/proxy_child.c
index eb47ae1e0..6bee1c7f6 100644
--- a/src/providers/proxy/proxy_child.c
+++ b/src/providers/proxy/proxy_child.c
@@ -47,7 +47,7 @@
 
 #include "providers/dp_backend.h"
 
-static int pc_pam_handler(struct sbus_request *dbus_req);
+static int pc_pam_handler(struct sbus_request *dbus_req, void *user_data);
 
 struct data_provider_iface pc_methods = {
     { &data_provider_iface_meta, 0 },
@@ -60,12 +60,6 @@ struct data_provider_iface pc_methods = {
     .getAccountInfo = NULL,
 };
 
-struct sbus_interface pc_interface = {
-    DP_PATH,
-    &pc_methods.vtable,
-    NULL
-};
-
 struct pc_ctx {
     struct tevent_context *ev;
     struct confdb_ctx *cdb;
@@ -310,20 +304,14 @@ fail:
     return ret;
 }
 
-static int pc_pam_handler(struct sbus_request *dbus_req)
+static int pc_pam_handler(struct sbus_request *dbus_req, void *user_data)
 {
     DBusError dbus_error;
     DBusMessage *reply;
     struct pc_ctx *pc_ctx;
     errno_t ret;
-    void *user_data;
     struct pam_data *pd = NULL;
 
-    user_data = sbus_conn_get_private_data(dbus_req->conn);
-    if (!user_data) {
-        ret = EINVAL;
-        goto done;
-    }
     pc_ctx = talloc_get_type(user_data, struct pc_ctx);
     if (!pc_ctx) {
         ret = EINVAL;
@@ -393,6 +381,7 @@ int proxy_child_send_id(struct sbus_connection *conn,
                         uint32_t id);
 static int proxy_cli_init(struct pc_ctx *ctx)
 {
+    struct sbus_interface *intf;
     char *sbus_address;
     int ret;
 
@@ -404,14 +393,23 @@ static int proxy_cli_init(struct pc_ctx *ctx)
         return ENOMEM;
     }
 
-    ret = sbus_client_init(ctx, ctx->ev, sbus_address,
-                           &pc_interface, &ctx->conn,
-                           NULL, ctx);
+    ret = sbus_client_init(ctx, ctx->ev, sbus_address, &ctx->conn);
     if (ret != EOK) {
         DEBUG(SSSDBG_CRIT_FAILURE, "sbus_client_init failed.\n");
         return ret;
     }
 
+    intf = sbus_new_interface(ctx, DP_PATH, &pc_methods.vtable, ctx);
+    if (!intf) {
+        ret = ENOMEM;
+    } else {
+        ret = sbus_conn_add_interface(ctx->conn, intf);
+    }
+    if (ret != EOK) {
+        DEBUG(SSSDBG_FATAL_FAILURE, "Failed to export proxy.\n");
+        return ret;
+    }
+
     ret = proxy_child_send_id(ctx->conn, DATA_PROVIDER_VERSION, ctx->id);
     if (ret != EOK) {
         DEBUG(SSSDBG_FATAL_FAILURE, "dp_common_send_id failed.\n");
diff --git a/src/providers/proxy/proxy_init.c b/src/providers/proxy/proxy_init.c
index 70fe337cd..0206ec15b 100644
--- a/src/providers/proxy/proxy_init.c
+++ b/src/providers/proxy/proxy_init.c
@@ -27,7 +27,7 @@
 #include "util/sss_format.h"
 #include "providers/proxy/proxy.h"
 
-static int client_registration(struct sbus_request *dbus_req);
+static int client_registration(struct sbus_request *dbus_req, void *data);
 
 static struct data_provider_iface proxy_methods = {
     { &data_provider_iface_meta, 0 },
@@ -40,12 +40,6 @@ static struct data_provider_iface proxy_methods = {
     .getAccountInfo = NULL,
 };
 
-struct sbus_interface proxy_interface = {
-    DP_PATH,
-    &proxy_methods.vtable,
-    NULL
-};
-
 static void proxy_shutdown(struct be_req *req)
 {
     /* TODO: Clean up any internal data */
@@ -337,6 +331,7 @@ static int proxy_client_init(struct sbus_connection *conn, void *data)
 {
     struct proxy_auth_ctx *proxy_auth_ctx;
     struct proxy_client *proxy_cli;
+    struct sbus_interface *intf;
     struct timeval tv;
 
     proxy_auth_ctx = talloc_get_type(data, struct proxy_auth_ctx);
@@ -369,9 +364,12 @@ static int proxy_client_init(struct sbus_connection *conn, void *data)
 
     /* Attach the client context to the connection context, so that it is
      * always available when we need to manage the connection. */
-    sbus_conn_set_private_data(conn, proxy_cli);
+    intf = sbus_new_interface(conn, DP_PATH, &proxy_methods.vtable, proxy_cli);
+    if (!intf) {
+        return ENOMEM;
+    }
 
-    return EOK;
+    return sbus_conn_add_interface(conn, intf);
 }
 
 static void init_timeout(struct tevent_context *ev,
@@ -394,7 +392,7 @@ static void init_timeout(struct tevent_context *ev,
      */
 }
 
-static int client_registration(struct sbus_request *dbus_req)
+static int client_registration(struct sbus_request *dbus_req, void *data)
 {
     dbus_uint16_t version = DATA_PROVIDER_VERSION;
     struct sbus_connection *conn;
@@ -403,7 +401,6 @@ static int client_registration(struct sbus_request *dbus_req)
     dbus_uint16_t cli_ver;
     uint32_t cli_id;
     dbus_bool_t dbret;
-    void *data;
     int hret;
     hash_key_t key;
     hash_value_t value;
@@ -413,7 +410,6 @@ static int client_registration(struct sbus_request *dbus_req)
     int ret;
 
     conn = dbus_req->conn;
-    data = sbus_conn_get_private_data(conn);
     proxy_cli = talloc_get_type(data, struct proxy_client);
     if (!proxy_cli) {
         DEBUG(SSSDBG_FATAL_FAILURE, "Connection holds no valid init data\n");
@@ -535,7 +531,7 @@ int sssm_proxy_auth_init(struct be_ctx *bectx,
         goto done;
     }
 
-    ret = sbus_new_server(ctx, bectx->ev, sbus_address, &proxy_interface,
+    ret = sbus_new_server(ctx, bectx->ev, sbus_address,
                           false, &ctx->sbus_srv, proxy_client_init, ctx);
     if (ret != EOK) {
         DEBUG(SSSDBG_FATAL_FAILURE, "Could not set up sbus server.\n");