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 "tx_thread.h"
29 #include "tx_timer.h"
30 #include "nx_ip.h"
31 #include "nx_tcp.h"
32 
33 
34 /**************************************************************************/
35 /*                                                                        */
36 /*  FUNCTION                                               RELEASE        */
37 /*                                                                        */
38 /*    _nx_tcp_receive_cleanup                             PORTABLE C      */
39 /*                                                           6.1          */
40 /*  AUTHOR                                                                */
41 /*                                                                        */
42 /*    Yuxin Zhou, Microsoft Corporation                                   */
43 /*                                                                        */
44 /*  DESCRIPTION                                                           */
45 /*                                                                        */
46 /*    This function processes TCP receive timeout and thread terminate    */
47 /*    actions that require the TCP socket data structures to be cleaned   */
48 /*    up.                                                                 */
49 /*                                                                        */
50 /*  INPUT                                                                 */
51 /*                                                                        */
52 /*    thread_ptr                            Pointer to suspended thread's */
53 /*                                            control block               */
54 /*                                                                        */
55 /*  OUTPUT                                                                */
56 /*                                                                        */
57 /*    None                                                                */
58 /*                                                                        */
59 /*  CALLS                                                                 */
60 /*                                                                        */
61 /*    tx_event_flags_set                    Set event flag                */
62 /*    _tx_thread_system_resume              Resume thread service         */
63 /*                                                                        */
64 /*  CALLED BY                                                             */
65 /*                                                                        */
66 /*    _nx_tcp_deferred_cleanup_check        Deferred cleanup processing   */
67 /*    _nx_tcp_socket_connection_reset       Socket reset connection       */
68 /*    _nx_tcp_socket_disconnect             Socket disconnect             */
69 /*    _tx_thread_timeout                    Thread timeout processing     */
70 /*    _tx_thread_terminate                  Thread terminate processing   */
71 /*                                                                        */
72 /*  RELEASE HISTORY                                                       */
73 /*                                                                        */
74 /*    DATE              NAME                      DESCRIPTION             */
75 /*                                                                        */
76 /*  05-19-2020     Yuxin Zhou               Initial Version 6.0           */
77 /*  09-30-2020     Yuxin Zhou               Modified comment(s),          */
78 /*                                            resulting in version 6.1    */
79 /*                                                                        */
80 /**************************************************************************/
_nx_tcp_receive_cleanup(TX_THREAD * thread_ptr NX_CLEANUP_PARAMETER)81 VOID  _nx_tcp_receive_cleanup(TX_THREAD *thread_ptr NX_CLEANUP_PARAMETER)
82 {
83 
84 TX_INTERRUPT_SAVE_AREA
85 
86 NX_IP         *ip_ptr;
87 NX_TCP_SOCKET *socket_ptr;  /* Working socket pointer  */
88 
89     NX_CLEANUP_EXTENSION
90 
91     /* Disable interrupts.  */
92     TX_DISABLE
93 
94     /* Setup pointer to TCP socket control block.  */
95     socket_ptr =  (NX_TCP_SOCKET *)thread_ptr -> tx_thread_suspend_control_block;
96 
97     /* Determine if the socket pointer is valid.  */
98     if ((!socket_ptr) || (socket_ptr -> nx_tcp_socket_id != NX_TCP_ID))
99     {
100 
101         /* Restore interrupts.  */
102         TX_RESTORE
103 
104         return;
105     }
106 
107     /* Determine if the cleanup is still required.  */
108     if (!(thread_ptr -> tx_thread_suspend_cleanup))
109     {
110 
111         /* Restore interrupts.  */
112         TX_RESTORE
113 
114         return;
115     }
116 
117     /* Determine if the caller is an ISR or the system timer thread.  */
118 #ifndef TX_TIMER_PROCESS_IN_ISR
119     if ((TX_THREAD_GET_SYSTEM_STATE()) || (_tx_thread_current_ptr == &_tx_timer_thread))
120 #else
121     if (TX_THREAD_GET_SYSTEM_STATE())
122 #endif
123     {
124 
125         /* Yes, defer the processing to the NetX IP thread.  */
126 
127         /* Yes, change the suspend cleanup routine to indicate the cleanup is deferred.  */
128         thread_ptr -> tx_thread_suspend_cleanup =  _nx_tcp_cleanup_deferred;
129 
130         /* Pickup the IP pointer.  */
131         ip_ptr =  socket_ptr -> nx_tcp_socket_ip_ptr;
132 
133         /* Restore interrupts.  */
134         TX_RESTORE
135 
136         /* Set the deferred cleanup flag for the IP thread.  */
137         tx_event_flags_set(&(ip_ptr -> nx_ip_events), NX_IP_TCP_CLEANUP_DEFERRED, TX_OR);
138 
139         /* Return to caller.  */
140         return;
141     }
142     else
143     {
144 
145         /* Yes, we still have thread suspension!  */
146 
147         /* Clear the suspension cleanup flag.  */
148         thread_ptr -> tx_thread_suspend_cleanup =  TX_NULL;
149 
150         /* Remove the suspended thread from the list.  */
151 
152         /* See if this is the only suspended thread on the list.  */
153         if (thread_ptr == thread_ptr -> tx_thread_suspended_next)
154         {
155 
156             /* Yes, the only suspended thread.  */
157 
158             /* Update the head pointer.  */
159             socket_ptr -> nx_tcp_socket_receive_suspension_list =  NX_NULL;
160         }
161         else
162         {
163 
164             /* At least one more thread is on the same suspension list.  */
165 
166             /* Update the list head pointer.  */
167             socket_ptr -> nx_tcp_socket_receive_suspension_list =  thread_ptr -> tx_thread_suspended_next;
168 
169             /* Update the links of the adjacent threads.  */
170             (thread_ptr -> tx_thread_suspended_next) -> tx_thread_suspended_previous =
171                 thread_ptr -> tx_thread_suspended_previous;
172             (thread_ptr -> tx_thread_suspended_previous) -> tx_thread_suspended_next =
173                 thread_ptr -> tx_thread_suspended_next;
174         }
175 
176         /* Decrement the suspension count.  */
177         socket_ptr -> nx_tcp_socket_receive_suspended_count--;
178 
179         /* Now we need to determine if this cleanup is from a terminate, timeout,
180            or from a wait abort.  */
181         if (thread_ptr -> tx_thread_state == TX_TCP_IP)
182         {
183 
184             /* Thread still suspended on the TCP socket.  Setup return error status and
185                resume the thread.  */
186 
187             /* Determine which receive error is present.  */
188             if (socket_ptr -> nx_tcp_socket_state != NX_TCP_ESTABLISHED)
189             {
190 
191                 /* This socket is no longer connected.  */
192                 thread_ptr -> tx_thread_suspend_status =  NX_NOT_CONNECTED;
193             }
194             else
195             {
196 
197                 /* Setup return status.  */
198                 thread_ptr -> tx_thread_suspend_status =  NX_NO_PACKET;
199             }
200 
201             /* Temporarily disable preemption.  */
202             _tx_thread_preempt_disable++;
203 
204             /* Restore interrupts.  */
205             TX_RESTORE
206 
207             /* Resume the thread!  Check for preemption even though we are executing
208                from the system timer thread right now which normally executes at the
209                highest priority.  */
210             _tx_thread_system_resume(thread_ptr);
211 
212             /* Finished, just return.  */
213             return;
214         }
215     }
216 
217     /* Restore interrupts.  */
218     TX_RESTORE
219 }
220 
221