1

src/config_parser.c

@@ -441,6 +441,10 @@ static int parse_server(const char *key, const char *value, struct CFG_SERVER *s
         if (srv->loss_rate > 100) srv->loss_rate = 100;
         return 0;
     }
+    if (strcmp(key, "only_local") == 0) {
+        srv->only_local = atoi(value) ? 1 : 0;
+        return 0;
+    }
     return 0;
 }
 

src/config_parser.h

@@ -37,6 +37,7 @@ struct CFG_SERVER {
     uint8_t type;  // public/nat/private
     int mtu;
     int loss_rate;  // packet loss rate in percent (0-100), default 0
+    uint8_t only_local;  // 1 = only local connections, no forwarding
 };
 
 struct CFG_CLIENT_LINK {

src/etcp_connections.c

@@ -92,6 +92,7 @@ static void etcp_link_send_init(struct ETCP_LINK* link, uint8_t reset) {
 
     dgram->data[offset++] = link->local_link_id;
     dgram->data[offset++] = link->conn ? link->conn->sock_id : 0;
+    dgram->data[offset++] = link->conn ? link->conn->only_local : 0;
 
     // padding
     int s = rand() % (link->handshake_maxsize - link->handshake_minsize) + link->handshake_minsize;
@@ -449,6 +450,7 @@ struct ETCP_SOCKET* etcp_socket_add(struct UTUN_INSTANCE* instance, struct CFG_S
     uint8_t type = server->type;
     int mtu = server->mtu ? server->mtu : instance->config->global.mtu;
     int loss_rate = server->loss_rate;
+    uint8_t only_local = server->only_local;
     char* name = server->name;
     
     struct ETCP_SOCKET* e_sock = u_calloc(1, sizeof(struct ETCP_SOCKET));
@@ -556,6 +558,7 @@ struct ETCP_SOCKET* etcp_socket_add(struct UTUN_INSTANCE* instance, struct CFG_S
     e_sock->nat_type = type; // initial type from config, updated after NAT detection
     e_sock->mtu = mtu;
     e_sock->loss_rate = loss_rate;
+    e_sock->only_local = only_local;
     DEBUG_INFO(DEBUG_CATEGORY_BGP, "Add Socket type=%d", type);
     e_sock->next = instance->etcp_sockets;
     instance->etcp_sockets = e_sock;
@@ -1166,6 +1169,7 @@ void etcp_connections_read_callback_socket(socket_t sock, void* arg) {
        uint8_t recovery[2];
        uint8_t link_id;
        uint8_t remote_socket_id;
+       uint8_t only_local;
        uint8_t pubkey[SC_PUBKEY_SIZE];
        } *ack_hdr=(void*)&pkt->data[0];
     uint64_t peer_id = be64toh(*(uint64_t*)ack_hdr->id);
@@ -1292,6 +1296,7 @@ void etcp_connections_read_callback_socket(socket_t sock, void* arg) {
         // Link exists - reuse it for recovery
         link->remote_link_id = ack_hdr->link_id;
         link->remote_socket_id = ack_hdr->remote_socket_id;
+        link->remote_only_local = ack_hdr->only_local;
 
         // For CHANNEL_INIT (0x04): if link already initialized - no reset, otherwise reset
         // For INIT_REQUEST (0x02): always reset
@@ -1315,6 +1320,7 @@ void etcp_connections_read_callback_socket(socket_t sock, void* arg) {
         if (!link) { if (new_conn) etcp_connection_close(conn); errorcode=66; DEBUG_ERROR(DEBUG_CATEGORY_CONNECTION, "etcp_connections_read_callback: failed to create link for connection"); goto ec_fr; }// облом
         link->remote_link_id = ack_hdr->link_id;
         link->remote_socket_id = ack_hdr->remote_socket_id;
+        link->remote_only_local = ack_hdr->only_local;
 
         // For new links: INIT_REQUEST (0x02) causes reset, CHANNEL_INIT (0x04) does not
         if (ack_hdr->code == ETCP_INIT_REQUEST || new_conn) {
@@ -1337,6 +1343,7 @@ void etcp_connections_read_callback_socket(socket_t sock, void* arg) {
        uint8_t mtu[2];
        uint8_t link_id;
        uint8_t remote_socket_id;
+       uint8_t only_local;
        uint8_t peer_ipv4[4];
        uint8_t peer_port[2];
        } *ack_repl_hdr=(void*)&pkt->data[0];
@@ -1355,6 +1362,7 @@ void etcp_connections_read_callback_socket(socket_t sock, void* arg) {
     ack_repl_hdr->mtu[1]=link->mtu_local;
     ack_repl_hdr->link_id = link->local_link_id;
     ack_repl_hdr->remote_socket_id = ack_hdr->remote_socket_id;
+    ack_repl_hdr->only_local = e_sock->only_local;
     // Add client's IP:port (so client behind NAT can know its external address)
     if (addr.ss_family == AF_INET) {
         struct sockaddr_in *sin = (struct sockaddr_in*)&addr;
@@ -1450,6 +1458,7 @@ process_decrypted:
         link->mtu = link->mtu_local < link->mtu_remote ? link->mtu_local : link->mtu_remote;
         link->remote_link_id = pkt->data[offset++];
         link->remote_socket_id = pkt->data[offset++];
+        link->remote_only_local = pkt->data[offset++];
 
         // Parse NAT IP:port from response (new format includes 4+2 bytes)
         if (pkt_len >= 19) {

src/etcp_connections.h

@@ -72,6 +72,7 @@ struct ETCP_SOCKET {
     uint8_t nat_type;       // NAT_TYPE_* (detected by server)
     uint32_t local_defaultroute_ip;  // auto-detected IPv4 for public servers (network byte order)
     uint8_t local_defaultroute_ip6[16];  // auto-detected IPv6 for public servers
+    uint8_t only_local;    // 1 = only local connections, no forwarding
 };
 
 // NAT check status
@@ -116,6 +117,7 @@ struct ETCP_LINK {
     uint8_t local_link_id;          // id моего линка
     uint8_t remote_link_id;         // id этого линка на peer (устанавливается в момент initialized)
     uint8_t remote_socket_id;       // socket id peer
+    uint8_t remote_only_local;      // only_local flag from peer
     uint8_t nat_type;               // NAT_TYPE_* (detected for this client link)
     uint8_t recv_keepalive;         // 1 - up, 0 - down (принимаются ли пакеты)
     uint8_t remote_keepalive;       // 1 - up, 0 - down (удаленная сторона сообщает - принимаются ли у нее пакеты)

src/route_bgp.c

@@ -572,7 +572,7 @@ static struct ETCP_CONN* route_bgp_find_third_node(struct ROUTE_BGP* bgp, struct
     struct ll_entry* e = bgp->senders_list->head;
     while (e) {
         struct ROUTE_BGP_CONN_ITEM* item = (struct ROUTE_BGP_CONN_ITEM*)e->data;
-        if (item && item->conn && item->conn != exclude) return item->conn;
+        if (item && item->conn && item->conn != exclude && item->conn->links && item->conn->links->remote_only_local==0) return item->conn;
         e = e->next;
     }
     return NULL;