From: Elear Solutions Dev <38581919+elear-solutions-dev@users.noreply.github.com>
Date: Sun, 20 Oct 2024 15:25:59 +0000 (+0530)
Subject: Feature external ip address
X-Git-Url: https://git.meshlink.io/?a=commitdiff_plain;h=refs%2Fheads%2Fmaster;p=meshlink

Feature external ip address

* Basic external_ip_address support

* Added support for port parsing for external IP address

* Cleanup some logging
---

diff --git a/src/meshlink.c b/src/meshlink.c
index a1a2ec40..d6349890 100644
--- a/src/meshlink.c
+++ b/src/meshlink.c
@@ -1656,6 +1656,19 @@ meshlink_handle_t *meshlink_open_ex(const meshlink_open_params_t *params) {
 		return NULL;
 	}
 
+	if(mesh->devclass == DEV_CLASS_BACKBONE) {
+		logger(NULL, MESHLINK_DEBUG, "Resolving external IP address as we are a backbone node\n");
+
+		mesh->self->external_ip_address = meshlink_get_external_address(mesh);
+
+		// if(meshlink_errno == MESHLINK_ERESOLV) {
+		if(!mesh->self->external_ip_address) {
+			logger(NULL, MESHLINK_WARNING, "Couldn't resolve external IP address, continuing without it...\n");
+		} else {
+			logger(NULL, MESHLINK_INFO, "Found external IP address: %s\n", mesh->self->external_ip_address);
+		}
+	}
+
 	add_local_addresses(mesh);
 
 	if(!node_write_config(mesh, mesh->self, new_configuration)) {
diff --git a/src/net_packet.c b/src/net_packet.c
index acc90c97..183631f8 100644
--- a/src/net_packet.c
+++ b/src/net_packet.c
@@ -339,20 +339,52 @@ static void choose_udp_address(meshlink_handle_t *mesh, const node_t *n, const s
 		goto check_socket;
 	}
 
+	/* Else, if we have a external IP address, try this once every batch */
+	if(mesh->udp_choice == 1 && n->external_ip_address) {
+		logger(mesh, MESHLINK_DEBUG, "Trying the external IP address...\n");
+
+		char *host = xstrdup(n->external_ip_address);
+		char *port = strchr(host, ' ');
+
+		if(port) {
+			*port++ = 0;
+			logger(mesh, MESHLINK_DEBUG, "Using external IP host: %s and port %s\n", host, port);
+			*sa_buf = str2sockaddr(host, port);
+			*sa = sa_buf;
+
+			if(sa_buf->sa.sa_family != AF_UNKNOWN) {
+				free(host);
+				goto check_socket;
+			} else {
+				logger(mesh, MESHLINK_DEBUG, "Couldn't create str2sockaddr, so skipping external IP address...\n");
+			}
+		} else {
+			logger(mesh, MESHLINK_DEBUG, "Couldn't find port, so skipping external IP address...\n");
+		}
+
+		free(host);
+	}
+
 	/* Else, if we have a canonical address, try this once every batch */
 	if(mesh->udp_choice == 1 && n->canonical_address) {
+		logger(mesh, MESHLINK_DEBUG, "Trying the canonical host...\n");
 		char *host = xstrdup(n->canonical_address);
 		char *port = strchr(host, ' ');
 
 		if(port) {
 			*port++ = 0;
+			logger(mesh, MESHLINK_DEBUG, "Using canonical host: %s and port %s\n", host, port);
 			*sa_buf = str2sockaddr_random(mesh, host, port);
 			*sa = sa_buf;
 
 			if(sa_buf->sa.sa_family != AF_UNKNOWN) {
 				free(host);
 				goto check_socket;
+			} else {
+				logger(mesh, MESHLINK_DEBUG, "Couldn't create str2sockaddr, so skipping canonical host...\n");
 			}
+		} else {
+			logger(mesh, MESHLINK_DEBUG, "Couldn't find port, so skipping canonical host...\n");
 		}
 
 		free(host);
diff --git a/src/node.c b/src/node.c
index b8caed6c..ae661a1b 100644
--- a/src/node.c
+++ b/src/node.c
@@ -82,6 +82,7 @@ void free_node(node_t *n) {
 
 	free(n->name);
 	free(n->canonical_address);
+	free(n->external_ip_address);
 
 	free(n);
 }
diff --git a/src/node.h b/src/node.h
index 918f1cce..2e6d1317 100644
--- a/src/node.h
+++ b/src/node.h
@@ -88,6 +88,7 @@ typedef struct node_t {
 	time_t last_successfull_connection;
 
 	char *canonical_address;                /* The canonical address of this node, if known */
+	char *external_ip_address;              /* The external IP address of this node, if known */
 	sockaddr_t recent[MAX_RECENT];          /* Recently seen addresses */
 	sockaddr_t catta_address;               /* Latest address seen by Catta */
 
diff --git a/src/protocol.h b/src/protocol.h
index 94f760f1..8a02ba38 100644
--- a/src/protocol.h
+++ b/src/protocol.h
@@ -49,6 +49,7 @@ typedef enum request_t {
 	REQ_PUBKEY, ANS_PUBKEY,
 	REQ_SPTPS,
 	REQ_CANONICAL,
+	REQ_EXTERNAL,
 	NUM_REQUESTS
 } request_t;
 
@@ -100,6 +101,7 @@ bool send_add_edge(struct meshlink_handle *mesh, struct connection_t *, const st
 bool send_del_edge(struct meshlink_handle *mesh, struct connection_t *, const struct edge_t *, int contradictions);
 bool send_req_key(struct meshlink_handle *mesh, struct node_t *);
 bool send_canonical_address(struct meshlink_handle *mesh, struct node_t *);
+bool send_external_ip_address(struct meshlink_handle *mesh, struct node_t *);
 bool send_raw_packet(struct meshlink_handle *mesh, struct connection_t *, const vpn_packet_t *);
 
 /* Request handlers  */
diff --git a/src/protocol_key.c b/src/protocol_key.c
index 745845a6..6e5c1a8f 100644
--- a/src/protocol_key.c
+++ b/src/protocol_key.c
@@ -83,6 +83,14 @@ static bool send_initial_sptps_data(void *handle, uint8_t type, const void *data
 	return send_request(mesh, to->nexthop->connection, NULL, "%d %s %s %d %s", REQ_KEY, mesh->self->name, to->name, REQ_KEY, buf);
 }
 
+bool send_external_ip_address(meshlink_handle_t *mesh, node_t *to) {
+	if(!mesh->self->external_ip_address) {
+		return true;
+	}
+
+	return send_request(mesh, to->nexthop->connection, NULL, "%d %s %s %d %s %s", REQ_KEY, mesh->self->name, to->name, REQ_EXTERNAL, mesh->self->external_ip_address, mesh->myport);
+}
+
 bool send_canonical_address(meshlink_handle_t *mesh, node_t *to) {
 	if(!mesh->self->canonical_address) {
 		return true;
@@ -113,6 +121,9 @@ bool send_req_key(meshlink_handle_t *mesh, node_t *to) {
 	/* Send our canonical address to help with UDP hole punching */
 	send_canonical_address(mesh, to);
 
+	/* Send our external IP address to help with UDP hole punching */
+	send_external_ip_address(mesh, to);
+
 	char label[sizeof(meshlink_udp_label) + strlen(mesh->self->name) + strlen(to->name) + 2];
 	snprintf(label, sizeof(label), "%s %s %s", meshlink_udp_label, mesh->self->name, to->name);
 	sptps_stop(&to->sptps);
@@ -231,6 +242,9 @@ static bool req_key_ext_h(meshlink_handle_t *mesh, connection_t *c, const char *
 		/* Send our canonical address to help with UDP hole punching */
 		send_canonical_address(mesh, from);
 
+		/* Send our external IP address to help with UDP hole punching */
+		send_external_ip_address(mesh, from);
+
 		if(!sptps_start(&from->sptps, from, false, true, mesh->private_key, from->ecdsa, label, sizeof(label) - 1, send_sptps_data, receive_sptps_record)) {
 			logger(mesh, MESHLINK_ERROR, "Could not start SPTPS session with %s: %s", from->name, strerror(errno));
 			return true;
@@ -287,6 +301,28 @@ static bool req_key_ext_h(meshlink_handle_t *mesh, connection_t *c, const char *
 		return true;
 	}
 
+	case REQ_EXTERNAL: {
+		char ip[MAX_STRING_SIZE];
+		char port[MAX_STRING_SIZE];
+		logger(mesh, MESHLINK_DEBUG, "Got %s from %s with data: %s", "REQ_EXTERNAL", from->name, request);
+
+		if(sscanf(request, "%*d %*s %*s %*d " MAX_STRING " " MAX_STRING, ip, port) != 2) {
+			logger(mesh, MESHLINK_ERROR, "Got bad %s from %s: %s", "REQ_EXTERNAL", from->name, request);
+			return true;
+		}
+
+		char *external_ip_address;
+		xasprintf(&external_ip_address, "%s %s", ip, port);
+
+		if(mesh->log_level <= MESHLINK_DEBUG && (!from->external_ip_address || strcmp(from->external_ip_address, external_ip_address))) {
+			logger(mesh, MESHLINK_DEBUG, "Updating external IP address of %s to %s", from->name, external_ip_address);
+		}
+
+		free(from->external_ip_address);
+		from->external_ip_address = external_ip_address;
+		return true;
+	}
+
 	default:
 		logger(mesh, MESHLINK_ERROR, "Unknown extended REQ_KEY request from %s: %s", from->name, request);
 		return true;