lib-smtp: client: Add support for recording extra (non-standard) capa…

…bilities from server.

src/lib-smtp/smtp-client-connection.c

@@ -56,6 +56,33 @@ uoff_t smtp_client_connection_get_size_capability(
 	return conn->caps.size;
 }
 
+void smtp_client_connection_accept_extra_capability(
+	struct smtp_client_connection *conn, const char *cap_name)
+{
+	cap_name = p_strdup(conn->pool, cap_name);
+
+	if (!array_is_created(&conn->extra_capabilities))
+		p_array_init(&conn->extra_capabilities, conn->pool, 8);
+	array_append(&conn->extra_capabilities, &cap_name, 1);
+}
+
+const struct smtp_capability_extra *
+smtp_client_connection_get_extra_capability(struct smtp_client_connection *conn,
+					    const char *name)
+{
+	const struct smtp_capability_extra *cap;
+
+	if (!array_is_created(&conn->caps.extra))
+		return NULL;
+
+	array_foreach(&conn->caps.extra, cap) {
+		if (strcasecmp(cap->name, name) == 0)
+			return cap;
+	}
+
+	return NULL;
+}
+
 /*
  * Logging
  */
@@ -872,6 +899,42 @@ smtp_client_connection_starttls(struct smtp_client_connection *conn)
 	return smtp_client_connection_init_xclient(conn);
 }
 
+static bool
+smtp_client_connection_has_extra_capability(struct smtp_client_connection *conn,
+					   const char *cap_name)
+{
+	const char *const *cap_idx;
+
+	if (!array_is_created(&conn->extra_capabilities))
+		return FALSE;
+	array_foreach(&conn->extra_capabilities, cap_idx) {
+		if (strcasecmp(*cap_idx, cap_name) == 0)
+			return TRUE;
+	}
+	return FALSE;
+}
+
+static void
+smtp_client_connection_record_exta_capability(
+	struct smtp_client_connection *conn, const char *cap_name,
+	const char *const *params)
+{
+	struct smtp_capability_extra cap_extra;
+	pool_t pool = conn->cap_pool;
+
+	if (!smtp_client_connection_has_extra_capability(conn, cap_name))
+		return;
+
+	if (!array_is_created(&conn->caps.extra))
+		p_array_init(&conn->caps.extra, pool, 4);
+
+	i_zero(&cap_extra);
+	cap_extra.name = p_strdup(pool, cap_name);
+	cap_extra.params = p_strarray_dup(pool, params);
+
+	array_append(&conn->caps.extra, &cap_extra, 1);
+}
+
 static void
 smtp_client_connection_handshake_cb(const struct smtp_reply *reply,
 				    struct smtp_client_connection *conn)
@@ -949,6 +1012,10 @@ smtp_client_connection_handshake_cb(const struct smtp_reply *reply,
 			conn->caps.xclient_args =
 				p_strarray_dup(conn->cap_pool, params);
 			break;
+		case SMTP_CAPABILITY_NONE:
+			smtp_client_connection_record_exta_capability(
+				conn, cap_name, params);
+			break;
 		default:
 			break;
 		}
@@ -1769,6 +1836,10 @@ smtp_client_connection_do_create(struct smtp_client *client, const char *name,
 			conn->set.my_hostname = p_strdup(pool, set->my_hostname);
 
 		conn->set.forced_capabilities |= set->forced_capabilities;
+		if (set->extra_capabilities != NULL) {
+			conn->set.extra_capabilities =
+				p_strarray_dup(pool, set->extra_capabilities);
+		}
 
 		if (set->rawlog_dir != NULL && *set->rawlog_dir != '\0')
 			conn->set.rawlog_dir = p_strdup_empty(pool, set->rawlog_dir);
@@ -1823,6 +1894,18 @@ smtp_client_connection_do_create(struct smtp_client *client, const char *name,
 		conn->set.peer_trusted = set->peer_trusted;
 	}
 
+
+	if (set != NULL && set->extra_capabilities != NULL) {
+		const char *const *extp;
+
+		p_array_init(&conn->extra_capabilities, pool,
+			     str_array_length(set->extra_capabilities) + 8);
+		for (extp = set->extra_capabilities; *extp != NULL; extp++) {
+			const char *ext = p_strdup(pool, *extp);
+			array_append(&conn->extra_capabilities, &ext, 1);
+		}
+	}
+
 	i_assert(conn->set.my_hostname != NULL &&
 		*conn->set.my_hostname != '\0');
 

src/lib-smtp/smtp-client-connection.h

@@ -73,6 +73,12 @@ enum smtp_capability
 smtp_client_connection_get_capabilities(struct smtp_client_connection *conn);
 uoff_t smtp_client_connection_get_size_capability(
 	struct smtp_client_connection *conn);
+void smtp_client_connection_accept_extra_capability(
+	struct smtp_client_connection *conn, const char *cap_name);
+const struct smtp_capability_extra *
+smtp_client_connection_get_extra_capability(struct smtp_client_connection *conn,
+					    const char *name);
+
 enum smtp_client_connection_state
 smtp_client_connection_get_state(struct smtp_client_connection *conn);
 

src/lib-smtp/smtp-client-private.h

@@ -152,10 +152,12 @@ struct smtp_client_connection {
 
 	struct smtp_client_settings set;
 	char *password;
+	ARRAY_TYPE(const_string) extra_capabilities;
 
 	pool_t cap_pool;
 	struct {
 		enum smtp_capability standard;
+		ARRAY(struct smtp_capability_extra) extra;
 		const char **auth_mechanisms;
 		const char **xclient_args;
 		uoff_t size;

src/lib-smtp/smtp-client.c

@@ -35,6 +35,10 @@ struct smtp_client *smtp_client_init(const struct smtp_client_settings *set)
 	client->set.my_hostname = p_strdup(pool, set->my_hostname);
 
 	client->set.forced_capabilities = set->forced_capabilities;
+	if (set->extra_capabilities != NULL) {
+		client->set.extra_capabilities =
+			p_strarray_dup(pool, set->extra_capabilities);
+	}
 
 	client->set.dns_client = set->dns_client;
 	client->set.dns_client_socket_path =

src/lib-smtp/smtp-client.h

@@ -45,6 +45,8 @@ struct smtp_client_settings {
 	/* Capabilities that are assumed to be enabled no matter whether the
 	   server indicates support. */
 	enum smtp_capability forced_capabilities;
+	/* Record these extra capabilities if returned in the EHLO response */
+	const char *const *extra_capabilities;
 
 	struct dns_client *dns_client;
 	const char *dns_client_socket_path;

src/lib-smtp/smtp-common.h

@@ -47,10 +47,17 @@ enum smtp_capability {
 
 	SMTP_CAPABILITY__ORCPT              = BIT(24),
 };
+
 struct smtp_capability_name {
 	const char *name;
 	enum smtp_capability capability;
 };
+
+struct smtp_capability_extra {
+	const char *name;
+	const char *const *params;
+};
+
 extern const struct smtp_capability_name smtp_capability_names[];
 
 enum smtp_capability smtp_capability_find_by_name(const char *cap_name);