Add LWIP Broadcast option for UDP socket.

Author: tymoteuszblochmobica

connectivity/lwipstack/source/LWIPStack.cpp

@@ -567,6 +567,22 @@ nsapi_error_t LWIP::setsockopt(nsapi_socket_t handle, int level, int optname, co
             }
             return 0;
 
+        case NSAPI_BROADCAST:
+            if (NETCONNTYPE_GROUP(s->conn->type) != NETCONN_UDP) {
+                return NSAPI_ERROR_UNSUPPORTED;
+            }
+
+            if (optlen != sizeof(int)) {
+                return NSAPI_ERROR_UNSUPPORTED;
+            }
+
+            if (*(const int *)optval) {
+                ip_set_option(s->conn->pcb.ip, SOF_BROADCAST);
+            } else {
+                ip_reset_option(s->conn->pcb.ip, SOF_BROADCAST);
+            }
+            return 0;
+
         case NSAPI_ADD_MEMBERSHIP:
         case NSAPI_DROP_MEMBERSHIP: {
             if (optlen != sizeof(nsapi_ip_mreq_t)) {

connectivity/netsocket/include/netsocket/nsapi_types.h

@@ -318,6 +318,7 @@ typedef enum nsapi_socket_option {
     NSAPI_LATENCY,           /*!< Read estimated latency to destination */
     NSAPI_STAGGER,           /*!< Read estimated stagger value to destination */
     NSAPI_IPTOS,             /*!< Set IP type of service to set specific precedence */
+    NSAPI_BROADCAST          /*!< Set broadcast flag for UDP socket */
 } nsapi_socket_option_t;
 
 typedef enum nsapi_tlssocket_level {