submission: relay backend: Provide access to the client connection an…

…d transaction for plugins.

src/submission/submission-backend-relay.c

@@ -981,7 +981,7 @@ backend_relay_cmd_quit(struct submission_backend *_backend,
  * Relay backend
  */
 
-struct submission_backend *
+struct submission_backend_relay *
 submission_backend_relay_create(
 	struct client *client,
 	const struct submision_backend_relay_settings *set)
@@ -1041,9 +1041,29 @@ submission_backend_relay_create(
 			smtp_client, set->protocol, set->path, &smtp_set);
 	}
 
+	return backend;
+}
+
+struct submission_backend *
+submission_backend_relay_get(struct submission_backend_relay *backend)
+{
 	return &backend->backend;
 }
 
+struct smtp_client_connection *
+submission_backend_relay_get_connection(
+	struct submission_backend_relay *backend)
+{
+	return backend->conn;
+}
+
+struct smtp_client_transaction *
+submission_backend_relay_get_transaction(
+	struct submission_backend_relay *backend)
+{
+	return backend->trans;
+}
+
 static void backend_relay_destroy(struct submission_backend *_backend)
 {
 	struct submission_backend_relay *backend =

src/submission/submission-backend-relay.h

@@ -6,6 +6,7 @@
 #include "submission-backend.h"
 
 struct client;
+struct submission_backend_relay;
 
 struct submision_backend_relay_settings {
 	const char *my_hostname;
@@ -29,9 +30,23 @@ struct submision_backend_relay_settings {
 	bool trusted:1;
 };
 
-struct submission_backend *
+struct submission_backend_relay *
 submission_backend_relay_create(
 	struct client *client,
 	const struct submision_backend_relay_settings *set);
 
+/* Returns the base backend object for this relay backend */
+struct submission_backend *
+submission_backend_relay_get(struct submission_backend_relay *backend)
+	ATTR_PURE;
+
+/* Returns the client connection for this relay backend */
+struct smtp_client_connection *
+submission_backend_relay_get_connection(
+	struct submission_backend_relay *backend) ATTR_PURE;
+/* Returns the current client transaction for this relay backend */
+struct smtp_client_transaction *
+submission_backend_relay_get_transaction(
+	struct submission_backend_relay *backend) ATTR_PURE;
+
 #endif

src/submission/submission-client.c

@@ -160,8 +160,10 @@ client_create_backend_default(struct client *client,
 		relay_set.ssl_mode = SMTP_CLIENT_SSL_MODE_NONE;
 	relay_set.ssl_verify = set->submission_relay_ssl_verify;
 
-	client->backend_default =
+	client->backend_default_relay =
 		submission_backend_relay_create(client, &relay_set);
+	client->backend_default =
+		submission_backend_relay_get(client->backend_default_relay);
 }
 
 static void client_init_urlauth(struct client *client)

src/submission/submission-client.h

@@ -7,6 +7,7 @@ struct smtp_reply;
 
 struct submission_recipient;
 struct submission_backend;
+struct submission_backend_relay;
 struct client;
 
 struct client_state {
@@ -101,6 +102,7 @@ struct client {
 
 	enum smtp_capability backend_capabilities;
 	struct submission_backend *backend_default;
+	struct submission_backend_relay *backend_default_relay;
 	struct submission_backend *backends;
 	unsigned int backends_count;