1 /***************************************************************************
2  * Copyright (c) 2024 Microsoft Corporation
3  *
4  * This program and the accompanying materials are made available under the
5  * terms of the MIT License which is available at
6  * https://opensource.org/licenses/MIT.
7  *
8  * SPDX-License-Identifier: MIT
9  **************************************************************************/
10 
11 
12 /**************************************************************************/
13 /**************************************************************************/
14 /**                                                                       */
15 /** NetX Component                                                        */
16 /**                                                                       */
17 /**   Transmission Control Protocol (TCP)                                 */
18 /**                                                                       */
19 /**************************************************************************/
20 /**************************************************************************/
21 
22 #define NX_SOURCE_CODE
23 
24 
25 /* Include necessary system files.  */
26 
27 #include "nx_api.h"
28 #include "nx_tcp.h"
29 
30 
31 /* Bring in externs for caller checking code.  */
32 NX_CALLER_CHECKING_EXTERNS
33 
34 
35 /**************************************************************************/
36 /*                                                                        */
37 /*  FUNCTION                                               RELEASE        */
38 /*                                                                        */
39 /*    _nxe_tcp_socket_mss_get                             PORTABLE C      */
40 /*                                                           6.1          */
41 /*  AUTHOR                                                                */
42 /*                                                                        */
43 /*    Yuxin Zhou, Microsoft Corporation                                   */
44 /*                                                                        */
45 /*  DESCRIPTION                                                           */
46 /*                                                                        */
47 /*    This function checks for errors in the socket local MSS get         */
48 /*    function call.                                                      */
49 /*                                                                        */
50 /*  INPUT                                                                 */
51 /*                                                                        */
52 /*    socket_ptr                            Pointer to the TCP socket     */
53 /*    mss                                   Destination for the MSS       */
54 /*                                                                        */
55 /*  OUTPUT                                                                */
56 /*                                                                        */
57 /*    status                                Completion status             */
58 /*                                                                        */
59 /*  CALLS                                                                 */
60 /*                                                                        */
61 /*    _nx_tcp_socket_mss_get                Actual socket MSS get         */
62 /*                                            function                    */
63 /*                                                                        */
64 /*  CALLED BY                                                             */
65 /*                                                                        */
66 /*    Application Code                                                    */
67 /*                                                                        */
68 /*  RELEASE HISTORY                                                       */
69 /*                                                                        */
70 /*    DATE              NAME                      DESCRIPTION             */
71 /*                                                                        */
72 /*  05-19-2020     Yuxin Zhou               Initial Version 6.0           */
73 /*  09-30-2020     Yuxin Zhou               Modified comment(s),          */
74 /*                                            resulting in version 6.1    */
75 /*                                                                        */
76 /**************************************************************************/
_nxe_tcp_socket_mss_get(NX_TCP_SOCKET * socket_ptr,ULONG * mss)77 UINT  _nxe_tcp_socket_mss_get(NX_TCP_SOCKET *socket_ptr, ULONG *mss)
78 {
79 
80 UINT status;
81 
82 
83     /* Check for invalid input pointers.  */
84     if ((socket_ptr == NX_NULL) || (socket_ptr -> nx_tcp_socket_id != NX_TCP_ID) || (mss == NX_NULL))
85     {
86         return(NX_PTR_ERROR);
87     }
88 
89     /* Check to see if TCP is enabled.  */
90     if (!(socket_ptr -> nx_tcp_socket_ip_ptr) -> nx_ip_tcp_packet_receive)
91     {
92         return(NX_NOT_ENABLED);
93     }
94 
95     /* Check for appropriate caller.  */
96     NX_INIT_AND_THREADS_CALLER_CHECKING
97 
98     /* Call actual TCP socket MSS get function.  */
99     status =  _nx_tcp_socket_mss_get(socket_ptr, mss);
100 
101     /* Return completion status.  */
102     return(status);
103 }
104 
105