1 /**************************************************************************/
2 /* */
3 /* Copyright (c) Microsoft Corporation. All rights reserved. */
4 /* */
5 /* This software is licensed under the Microsoft Software License */
6 /* Terms for Microsoft Azure RTOS. Full text of the license can be */
7 /* found in the LICENSE file at https://aka.ms/AzureRTOS_EULA */
8 /* and in the root directory of this software. */
9 /* */
10 /**************************************************************************/
11
12
13 /**************************************************************************/
14 /**************************************************************************/
15 /** */
16 /** NetX Component */
17 /** */
18 /** Transmission Control Protocol (TCP) */
19 /** */
20 /**************************************************************************/
21 /**************************************************************************/
22
23 #define NX_SOURCE_CODE
24
25
26 /* Include necessary system files. */
27
28 #include "nx_api.h"
29 #include "nx_ip.h"
30 #include "nx_tcp.h"
31
32
33 /**************************************************************************/
34 /* */
35 /* FUNCTION RELEASE */
36 /* */
37 /* _nx_tcp_socket_state_fin_wait2 PORTABLE C */
38 /* 6.1 */
39 /* AUTHOR */
40 /* */
41 /* Yuxin Zhou, Microsoft Corporation */
42 /* */
43 /* DESCRIPTION */
44 /* */
45 /* This function processes packets during the FIN WAIT 2 state, */
46 /* which is the state after the initial FIN was issued and the other */
47 /* side of the connection issued an ACK. If a FIN is received in */
48 /* this state, an ACK is sent back the disconnection is complete. */
49 /* */
50 /* INPUT */
51 /* */
52 /* socket_ptr Pointer to owning socket */
53 /* */
54 /* OUTPUT */
55 /* */
56 /* None */
57 /* */
58 /* CALLS */
59 /* */
60 /* _nx_tcp_packet_send_ack Send ACK message */
61 /* */
62 /* CALLED BY */
63 /* */
64 /* _nx_tcp_socket_packet_process Process TCP packet for socket */
65 /* */
66 /* RELEASE HISTORY */
67 /* */
68 /* DATE NAME DESCRIPTION */
69 /* */
70 /* 05-19-2020 Yuxin Zhou Initial Version 6.0 */
71 /* 09-30-2020 Yuxin Zhou Modified comment(s), */
72 /* resulting in version 6.1 */
73 /* */
74 /**************************************************************************/
_nx_tcp_socket_state_fin_wait2(NX_TCP_SOCKET * socket_ptr)75 VOID _nx_tcp_socket_state_fin_wait2(NX_TCP_SOCKET *socket_ptr)
76 {
77
78
79 /* Determine if a FIN has been previously detected in the _nx_tcp_socket_state_data_check
80 routine and if the socket's sequence number matches the expected FIN sequence number. */
81 if ((socket_ptr -> nx_tcp_socket_fin_received) &&
82 (socket_ptr -> nx_tcp_socket_fin_sequence == socket_ptr -> nx_tcp_socket_rx_sequence))
83 {
84
85 /* Return to the proper socket state. */
86
87 /* Yes, return the socket to the TIMED WAIT state. */
88
89 /* If trace is enabled, insert this event into the trace buffer. */
90 NX_TRACE_IN_LINE_INSERT(NX_TRACE_INTERNAL_TCP_STATE_CHANGE, socket_ptr -> nx_tcp_socket_ip_ptr, socket_ptr, socket_ptr -> nx_tcp_socket_state, NX_TCP_TIMED_WAIT, NX_TRACE_INTERNAL_EVENTS, 0, 0);
91
92 /* Set the socket state to TIMED WAIT now. */
93 socket_ptr -> nx_tcp_socket_state = NX_TCP_TIMED_WAIT;
94
95 /* Set the timeout as 2MSL (Maximum Segment Lifetime). */
96 socket_ptr -> nx_tcp_socket_timeout = _nx_tcp_2MSL_timer_rate;
97
98 /* Send ACK back to the other side of the connection. */
99
100 /* Increment the received sequence number. */
101 socket_ptr -> nx_tcp_socket_rx_sequence++;
102
103 /* Send ACK message. */
104 _nx_tcp_packet_send_ack(socket_ptr, socket_ptr -> nx_tcp_socket_tx_sequence);
105
106 /* Determine if we need to wake a thread suspended on the connection. */
107 if (socket_ptr -> nx_tcp_socket_disconnect_suspended_thread)
108 {
109
110 /* Resume the thread suspended for the disconnect. */
111 _nx_tcp_socket_thread_resume(&(socket_ptr -> nx_tcp_socket_disconnect_suspended_thread), NX_SUCCESS);
112 }
113
114 /* If given, call the application's disconnect callback function
115 for disconnect. */
116 if (socket_ptr -> nx_tcp_disconnect_callback)
117 {
118
119 /* Call the application's disconnect handling function. It is
120 responsible for calling the socket disconnect function. */
121 (socket_ptr -> nx_tcp_disconnect_callback)(socket_ptr);
122 }
123
124 #ifndef NX_DISABLE_EXTENDED_NOTIFY_SUPPORT
125
126 /* Is a timed wait callback registered for this socket? */
127 if (socket_ptr -> nx_tcp_timed_wait_callback)
128 {
129
130 /* Call the timed wait callback for this socket to let the host
131 know the socket can now be put in the timed wait state (if
132 the RE-USE ADDRESS socket option is not enabled). */
133 (socket_ptr -> nx_tcp_timed_wait_callback)(socket_ptr);
134 }
135
136 /* Is a disconnect complete callback registered with the TCP socket? */
137 if (socket_ptr -> nx_tcp_disconnect_complete_notify)
138 {
139
140 /* Call the application's disconnect_complete callback function. */
141 (socket_ptr -> nx_tcp_disconnect_complete_notify)(socket_ptr);
142 }
143 #endif
144 }
145 }
146
147
