From 0a02c50ca8c9d6e66629c0354d56517125411af7 Mon Sep 17 00:00:00 2001
From: Guus Sliepen <guus@meshlink.io>
Date: Fri, 11 Mar 2016 16:10:55 +0100
Subject: [PATCH] Add the meshlink_get_port() and meshlink_set_port()
 functions.

The latter can be used to change the port on which MeshLink
listens. It may only be called when the mesh is not running.
---
 src/meshlink.c | 60 ++++++++++++++++++++++++++++++++++++++++++++++++++
 src/meshlink.h | 27 +++++++++++++++++++++++
 src/utcp       |  2 +-
 3 files changed, 88 insertions(+), 1 deletion(-)

diff --git a/src/meshlink.c b/src/meshlink.c
index 418be9e8..446e8d24 100644
--- a/src/meshlink.c
+++ b/src/meshlink.c
@@ -1512,6 +1512,66 @@ bool meshlink_add_external_address(meshlink_handle_t *mesh) {
 	return rval;
 }
 
+int meshlink_get_port(meshlink_handle_t *mesh) {
+	if(!mesh) {
+		meshlink_errno = MESHLINK_EINVAL;
+		return -1;
+	}
+
+	if(!mesh->myport) {
+		meshlink_errno = MESHLINK_EINTERNAL;
+		return -1;
+	}
+
+	return atoi(mesh->myport);
+}
+
+bool meshlink_set_port(meshlink_handle_t *mesh, int port) {
+	if(!mesh || port < 0 || port >= 65536 || mesh->threadstarted) {
+		meshlink_errno = MESHLINK_EINVAL;
+		return false;
+	}
+
+	if(mesh->myport && port == atoi(mesh->myport))
+		return true;
+
+	if(!try_bind(port)) {
+		meshlink_errno = MESHLINK_ENETWORK;
+		return false;
+	}
+
+	bool rval = false;
+
+	pthread_mutex_lock(&(mesh->mesh_mutex));
+	if(mesh->threadstarted) {
+		meshlink_errno = MESHLINK_EINVAL;
+		goto done;
+	}
+
+	close_network_connections(mesh);
+	exit_configuration(&mesh->config);
+
+	char portstr[10];
+	snprintf(portstr, sizeof portstr, "%d", port);
+	portstr[sizeof portstr - 1] = 0;
+
+	modify_config_file(mesh, mesh->name, "Port", portstr, true);
+
+	init_configuration(&mesh->config);
+
+	if(!read_server_config(mesh))
+		meshlink_errno = MESHLINK_ESTORAGE;
+	else if(!setup_network(mesh))
+		meshlink_errno = MESHLINK_ENETWORK;
+	else
+		rval = true;
+
+done:
+	pthread_mutex_unlock(&(mesh->mesh_mutex));
+
+	return rval;
+}
+
 char *meshlink_invite(meshlink_handle_t *mesh, const char *name) {
 	if(!mesh) {
 		meshlink_errno = MESHLINK_EINVAL;
diff --git a/src/meshlink.h b/src/meshlink.h
index 1c1e7af4..26c7edb5 100644
--- a/src/meshlink.h
+++ b/src/meshlink.h
@@ -457,6 +457,33 @@ extern char *meshlink_get_external_address(meshlink_handle_t *mesh);
  */
 extern bool meshlink_add_external_address(meshlink_handle_t *mesh);
 
+/// Get the network port used by the local node.
+/** This function returns the network port that the local node is listening on.
+ *
+ *  @param mesh          A handle which represents an instance of MeshLink.
+ *
+ *  @return              This function returns the port number, or -1 in case of an error.
+ */
+extern int meshlink_get_port(meshlink_handle_t *mesh);
+
+/// Set the network port used by the local node.
+/** This function sets the network port that the local node is listening on.
+ *  It may only be called when the mesh is not running.
+ *  If unsure, call meshlink_stop() before calling this function.
+ *  Also note that if your node is already part of a mesh with other nodes,
+ *  that the other nodes may no longer be able to initiate connections to the local node,
+ *  since they will try to connect to the previously configured port.
+ *
+ *  @param mesh          A handle which represents an instance of MeshLink.
+ *  @param port          The port number to listen on. This must be between 0 and 65535.
+ *                       If the port is set to 0, then MeshLink will listen on a port
+ *                       that is randomly assigned by the operating system every time meshlink_open() is called.
+ *
+ *  @return              This function returns true if the port was succesfully changed, false otherwise.
+ */
+
+extern bool meshlink_set_port(meshlink_handle_t *mesh, int port);
+
 /// Invite another node into the mesh.
 /** This function generates an invitation that can be used by another node to join the same mesh as the local node.
  *  The generated invitation is a string containing a URL.
diff --git a/src/utcp b/src/utcp
index b570e123..a7ec88e6 160000
--- a/src/utcp
+++ b/src/utcp
@@ -1 +1 @@
-Subproject commit b570e123128f3fafa583bae186fd61429dcb49a7
+Subproject commit a7ec88e641e14ca115fece6d1ea0e6c43144853f
-- 
2.39.2