text: /**************************************************************************/
  /*                                                                        */
  /*       Copyright (c) Microsoft Corporation. All rights reserved.        */
  /*                                                                        */
  /*       This software is licensed under the Microsoft Software License   */
  /*       Terms for Microsoft Azure RTOS. Full text of the license can be  */
  /*       found in the LICENSE file at https://aka.ms/AzureRTOS_EULA       */
  /*       and in the root directory of this software.                      */
  /*                                                                        */
  /**************************************************************************/
  
  
  /**************************************************************************/
  /**************************************************************************/
  /**                                                                       */
  /** NetX Component                                                        */
  /**                                                                       */
  /**   User Datagram Protocol (UDP)                                        */
  /**                                                                       */
  /**************************************************************************/
  /**************************************************************************/
  
  #define NX_SOURCE_CODE
  
  
  /* Include necessary system files.  */
  
  #include "nx_api.h"
  #include "nx_ip.h"
  #include "nx_udp.h"
  #include "nx_packet.h"
  #ifdef FEATURE_NX_IPV6
  #include "nx_ipv6.h"
  #endif /* FEATURE_NX_IPV6 */
  
  /* Bring in externs for caller checking code.  */
  
  NX_CALLER_CHECKING_EXTERNS
  
  
  /**************************************************************************/
  /*                                                                        */
  /*  FUNCTION                                               RELEASE        */
  /*                                                                        */
  /*    _nxe_udp_socket_send                                PORTABLE C      */
  /*                                                           6.1          */
  /*  AUTHOR                                                                */
  /*                                                                        */
  /*    Yuxin Zhou, Microsoft Corporation                                   */
  /*                                                                        */
  /*  DESCRIPTION                                                           */
  /*                                                                        */
  /*    This function checks for errors in the UDP socket send              */
  /*    function call.                                                      */
  /*                                                                        */
  /*  INPUT                                                                 */
  /*                                                                        */
  /*    socket_ptr                            Pointer to UDP socket         */
  /*    packet_ptr                            Pointer to UDP packet         */
  /*    ip_address                            IP address                    */
  /*    port                                  16-bit UDP port number        */
  /*                                                                        */
  /*  OUTPUT                                                                */
  /*                                                                        */
  /*    status                                Actual completion status      */
  /*    NX_PTR_ERROR                          Invalid pointer input         */
  /*    NX_NOT_ENABLED                        UDP not enabled               */
  /*    NX_IP_ADDRESS_ERROR                   NULL address input            */
  /*    NX_INVALID_PORT                       Invalid UDP socket port       */
  /*    NX_UNDERFLOW                          Invalid pointer to packet data*/
  /*    NX_OVERFLOW                           Invalid pointer to packet data*/
  /*    NX_CALLER_ERROR                       Invalid (non thread) caller   */
  /*                                                                        */
  /*  CALLS                                                                 */
  /*                                                                        */
  /*    _nx_udp_socket_send                   Actual UDP socket send        */
  /*                                            function                    */
  /*                                                                        */
  /*  CALLED BY                                                             */
  /*                                                                        */
  /*    Application Code                                                    */
  /*                                                                        */
  /*  RELEASE HISTORY                                                       */
  /*                                                                        */
  /*    DATE              NAME                      DESCRIPTION             */
  /*                                                                        */
  /*  05-19-2020     Yuxin Zhou               Initial Version 6.0           */
  /*  09-30-2020     Yuxin Zhou               Modified comment(s),          */
  /*                                            resulting in version 6.1    */
  /*                                                                        */
  /**************************************************************************/
  UINT  _nxe_udp_socket_send(NX_UDP_SOCKET *socket_ptr, NX_PACKET **packet_ptr_ptr,
                             ULONG ip_address, UINT port)
  {
  
  #ifndef NX_DISABLE_IPV4
  NX_PACKET *packet_ptr;
  UINT       status;
  
  
      /* Setup packet pointer.  */
      packet_ptr =  *packet_ptr_ptr;
  
      /* Check for invalid input pointers.  */
      /*lint -e{923} suppress cast of ULONG to pointer.  */
      if ((socket_ptr == NX_NULL) || (socket_ptr -> nx_udp_socket_id != NX_UDP_ID) ||
          (packet_ptr == NX_NULL) || (packet_ptr -> nx_packet_union_next.nx_packet_tcp_queue_next != ((NX_PACKET *)NX_PACKET_ALLOCATED)))
      {
  
          return(NX_PTR_ERROR);
      }
  
      /* Check to see if UDP is enabled.  */
      if (!(socket_ptr -> nx_udp_socket_ip_ptr) -> nx_ip_udp_packet_receive)
      {
          return(NX_NOT_ENABLED);
      }
  
      /* Check for invalid IP address.  */
      if (ip_address == NX_NULL)
      {
          return(NX_IP_ADDRESS_ERROR);
      }
  
      /* Check for an invalid port.  */
      if (((ULONG)port) > (ULONG)NX_MAX_PORT)
      {
          return(NX_INVALID_PORT);
      }
  
      /* Check for an invalid packet prepend pointer.  */
      /*lint -e{946} -e{947} suppress pointer subtraction, since it is necessary. */
      if ((INT)(packet_ptr -> nx_packet_prepend_ptr - packet_ptr -> nx_packet_data_start) < (INT)(sizeof(NX_IPV4_HEADER) + sizeof(NX_UDP_HEADER)))
      {
  
  #ifndef NX_DISABLE_UDP_INFO
          /* Increment the total UDP invalid packet count.  */
          (socket_ptr -> nx_udp_socket_ip_ptr) -> nx_ip_udp_invalid_packets++;
  
          /* Increment the total UDP invalid packet count for this socket.  */
          socket_ptr -> nx_udp_socket_invalid_packets++;
  #endif
  
          /* Return error code.  */
          return(NX_UNDERFLOW);
      }
  
      /* Check for an invalid packet append pointer.  */
      /*lint -e{946} suppress pointer subtraction, since it is necessary. */
      if (packet_ptr -> nx_packet_append_ptr > packet_ptr -> nx_packet_data_end)
      {
  
  #ifndef NX_DISABLE_UDP_INFO
          /* Increment the total UDP invalid packet count.  */
          (socket_ptr -> nx_udp_socket_ip_ptr) -> nx_ip_udp_invalid_packets++;
  
          /* Increment the total UDP invalid packet count for this socket.  */
          socket_ptr -> nx_udp_socket_invalid_packets++;
  #endif
  
          /* Return error code.  */
          return(NX_OVERFLOW);
      }
  
      /* Check for appropriate caller.  */
      NX_THREADS_ONLY_CALLER_CHECKING
  
      /* Call actual UDP socket send function.  */
      status =  _nx_udp_socket_send(socket_ptr, packet_ptr, ip_address, port);
  
      /* Determine if the packet send was successful.  */
      if (status == NX_SUCCESS)
      {
  
          /* Yes, now clear the application's packet pointer so it can't be accidentally
             used again by the application.  This is only done when error checking is
             enabled.  */
          *packet_ptr_ptr =  NX_NULL;
      }
  
      /* Return completion status.  */
      return(status);
  #else
      NX_PARAMETER_NOT_USED(socket_ptr);
      NX_PARAMETER_NOT_USED(packet_ptr_ptr);
      NX_PARAMETER_NOT_USED(ip_address);
      NX_PARAMETER_NOT_USED(port);
  
      return(NX_NOT_SUPPORTED);
  #endif /* !NX_DISABLE_IPV4  */
  }
  
  