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_ip.h"
29 #include "nx_tcp.h"
30 
31 
32 /* Bring in externs for caller checking code.  */
33 
34 NX_CALLER_CHECKING_EXTERNS
35 
36 
37 /**************************************************************************/
38 /*                                                                        */
39 /*  FUNCTION                                               RELEASE        */
40 /*                                                                        */
41 /*    _nxe_tcp_free_port_find                             PORTABLE C      */
42 /*                                                           6.1          */
43 /*  AUTHOR                                                                */
44 /*                                                                        */
45 /*    Yuxin Zhou, Microsoft Corporation                                   */
46 /*                                                                        */
47 /*  DESCRIPTION                                                           */
48 /*                                                                        */
49 /*    This function checks for errors in the TCP free port find           */
50 /*    function call.                                                      */
51 /*                                                                        */
52 /*  INPUT                                                                 */
53 /*                                                                        */
54 /*    ip_ptr                                IP instance pointer           */
55 /*    port                                  Starting port                 */
56 /*    free_port_ptr                         Pointer to return free port   */
57 /*                                                                        */
58 /*  OUTPUT                                                                */
59 /*                                                                        */
60 /*    status                                Completion status             */
61 /*                                                                        */
62 /*  CALLS                                                                 */
63 /*                                                                        */
64 /*    _nx_tcp_free_port_find                Actual TCP free port find     */
65 /*                                            function                    */
66 /*                                                                        */
67 /*  CALLED BY                                                             */
68 /*                                                                        */
69 /*    Application Code                                                    */
70 /*                                                                        */
71 /*  RELEASE HISTORY                                                       */
72 /*                                                                        */
73 /*    DATE              NAME                      DESCRIPTION             */
74 /*                                                                        */
75 /*  05-19-2020     Yuxin Zhou               Initial Version 6.0           */
76 /*  09-30-2020     Yuxin Zhou               Modified comment(s),          */
77 /*                                            resulting in version 6.1    */
78 /*                                                                        */
79 /**************************************************************************/
_nxe_tcp_free_port_find(NX_IP * ip_ptr,UINT port,UINT * free_port_ptr)80 UINT  _nxe_tcp_free_port_find(NX_IP *ip_ptr, UINT port, UINT *free_port_ptr)
81 {
82 
83 UINT status;
84 
85 
86     /* Check for invalid input pointers.  */
87     if ((ip_ptr == NX_NULL) || (ip_ptr -> nx_ip_id != NX_IP_ID) || (free_port_ptr == NX_NULL))
88     {
89         return(NX_PTR_ERROR);
90     }
91 
92     /* Check to see if TCP is enabled.  */
93     if (!ip_ptr -> nx_ip_tcp_packet_receive)
94     {
95         return(NX_NOT_ENABLED);
96     }
97 
98     /* Check for an invalid port.  */
99     if (((ULONG)port) > (ULONG)NX_MAX_PORT)
100     {
101         return(NX_INVALID_PORT);
102     }
103 
104     /* Check for appropriate caller.  */
105     NX_THREADS_ONLY_CALLER_CHECKING
106 
107     /* Call actual TCP free port find function.  */
108     status =  _nx_tcp_free_port_find(ip_ptr, port, free_port_ptr);
109 
110     /* Return completion status.  */
111     return(status);
112 }
113 
114