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 /** POSIX wrapper for THREADX                                             */
16 /**                                                                       */
17 /**                                                                       */
18 /**                                                                       */
19 /**************************************************************************/
20 /**************************************************************************/
21 
22 /* Include necessary system files.  */
23 
24 #include "tx_api.h"    /* Threadx API */
25 #include "pthread.h"  /* Posix API */
26 #include "px_int.h"    /* Posix helper functions */
27 
28 /**************************************************************************/
29 /*                                                                        */
30 /*  FUNCTION                                               RELEASE        */
31 /*                                                                        */
32 /*    posix_find_queue                                    PORTABLE C      */
33 /*                                                           6.1.7        */
34 /*  AUTHOR                                                                */
35 /*                                                                        */
36 /*    William E. Lamie, Microsoft Corporation                             */
37 /*                                                                        */
38 /*  DESCRIPTION                                                           */
39 /*                                                                        */
40 /*    This routine returns queue descriptor indicating that name of       */
41 /*    in the message queue.exists.                                        */
42 /*                                                                        */
43 /*  INPUT                                                                 */
44 /*                                                                        */
45 /*    const char * mq_name                     Name of the message queue  */
46 /*                                                                        */
47 /*  OUTPUT                                                                */
48 /*                                                                        */
49 /*    q_ptr                                    If successful              */
50 /*                                                                        */
51 /*  CALLS                                                                 */
52 /*                                                                        */
53 /*    None                                                                */
54 /*                                                                        */
55 /*  CALLED BY                                                             */
56 /*                                                                        */
57 /*    POSIX internal Code                                                 */
58 /*                                                                        */
59 /*  RELEASE HISTORY                                                       */
60 /*                                                                        */
61 /*    DATE              NAME                      DESCRIPTION             */
62 /*                                                                        */
63 /*  06-02-2021     William E. Lamie         Initial Version 6.1.7         */
64 /*                                                                        */
65 /**************************************************************************/
posix_find_queue(const CHAR * mq_name)66 POSIX_MSG_QUEUE * posix_find_queue(const CHAR *mq_name)
67 {
68 
69 POSIX_MSG_QUEUE        *q_ptr;
70 ULONG                   index;
71 ULONG                   match;
72 CHAR                   *dummy_name;
73 CHAR                   *dummy_queue_name;
74 ULONG                   namelength;
75 
76     q_ptr = (POSIX_MSG_QUEUE*)NULL;
77 
78     /* For checking the name.  */
79     for(index = 0,q_ptr = posix_queue_pool;index < POSIX_MAX_QUEUES ;index ++,q_ptr ++)
80     {
81         /* Assume the worst case.  */
82         match = TX_FALSE;
83         if(q_ptr->in_use == TX_TRUE)
84         {
85             dummy_queue_name = q_ptr->name;
86             for(namelength = 0 ,dummy_name = (CHAR *) mq_name ; namelength < PATH_MAX ;
87                   namelength ++, dummy_name++,dummy_queue_name ++)
88             {
89                 /*  Copy name.  */
90                 if (*dummy_name == *dummy_queue_name)
91                 {
92                     /* End of the string.  */
93                     if(*dummy_name == '\0')
94                     {
95                         match = TX_TRUE;
96                         break;
97                     }
98                 }/* Copy name.  */
99                 else
100                     break;
101             }
102         }
103         if(match==TX_TRUE)
104             break;
105    }
106    /* For each message queue.  */
107    if(match==TX_TRUE)
108        return(q_ptr);
109    /* Returns NULL if match not found. */
110    q_ptr = (POSIX_MSG_QUEUE*)NULL;
111    return (q_ptr);
112 }
113