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 /**************************************************************************/
33 /* */
34 /* FUNCTION RELEASE */
35 /* */
36 /* _nx_tcp_socket_state_fin_wait1 PORTABLE C */
37 /* 6.1 */
38 /* AUTHOR */
39 /* */
40 /* Yuxin Zhou, Microsoft Corporation */
41 /* */
42 /* DESCRIPTION */
43 /* */
44 /* This function processes packets during the FIN WAIT 1 state, */
45 /* which is the state after the initial FIN was issued in an active */
46 /* disconnect issued by the application. */
47 /* */
48 /* INPUT */
49 /* */
50 /* socket_ptr Pointer to owning socket */
51 /* */
52 /* OUTPUT */
53 /* */
54 /* None */
55 /* */
56 /* CALLS */
57 /* */
58 /* _nx_tcp_packet_send_ack Send ACK message */
59 /* _nx_tcp_socket_thread_resume Resume suspended thread */
60 /* */
61 /* CALLED BY */
62 /* */
63 /* _nx_tcp_socket_packet_process Process TCP packet for socket */
64 /* */
65 /* RELEASE HISTORY */
66 /* */
67 /* DATE NAME DESCRIPTION */
68 /* */
69 /* 05-19-2020 Yuxin Zhou Initial Version 6.0 */
70 /* 09-30-2020 Yuxin Zhou Modified comment(s), */
71 /* resulting in version 6.1 */
72 /* */
73 /**************************************************************************/
_nx_tcp_socket_state_fin_wait1(NX_TCP_SOCKET * socket_ptr)74 VOID _nx_tcp_socket_state_fin_wait1(NX_TCP_SOCKET *socket_ptr)
75 {
76
77
78 /* Determine if the peer has proper ACK number but FIN is not sent,
79 move into the FIN WAIT 2 state and do nothing else. */
80 if ((socket_ptr -> nx_tcp_socket_fin_acked) &&
81 (socket_ptr -> nx_tcp_socket_fin_received == NX_FALSE))
82 {
83
84 /* If trace is enabled, insert this event into the trace buffer. */
85 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_FIN_WAIT_2, NX_TRACE_INTERNAL_EVENTS, 0, 0);
86
87 /* We have a legitimate ACK message. Simply move into the WAIT FIN 2 state
88 for the other side to finish its processing and disconnect. */
89 socket_ptr -> nx_tcp_socket_state = NX_TCP_FIN_WAIT_2;
90
91 /* Otherwise, simply clear the FIN timeout. */
92 socket_ptr -> nx_tcp_socket_timeout = 0;
93 }
94 else if ((socket_ptr -> nx_tcp_socket_fin_acked) &&
95 (socket_ptr -> nx_tcp_socket_fin_sequence == socket_ptr -> nx_tcp_socket_rx_sequence))
96 {
97
98 /* Return to the proper socket state. */
99
100 /* Yes, return the socket to the TIMED WAIT state. */
101
102 /* If trace is enabled, insert this event into the trace buffer. */
103 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);
104
105 /* Set the socket state to TIMED WAIT now. */
106 socket_ptr -> nx_tcp_socket_state = NX_TCP_TIMED_WAIT;
107
108 /* Set the timeout as 2MSL (Maximum Segment Lifetime). */
109 socket_ptr -> nx_tcp_socket_timeout = _nx_tcp_2MSL_timer_rate;
110
111 /* Send ACK back to the other side of the connection. */
112
113 /* Increment the received sequence number. */
114 socket_ptr -> nx_tcp_socket_rx_sequence++;
115
116 /* Send ACK message. */
117 _nx_tcp_packet_send_ack(socket_ptr, socket_ptr -> nx_tcp_socket_tx_sequence);
118
119 /* Determine if we need to wake a thread suspended on the connection. */
120 if (socket_ptr -> nx_tcp_socket_disconnect_suspended_thread)
121 {
122
123 /* Resume the thread suspended for the disconnect. */
124 _nx_tcp_socket_thread_resume(&(socket_ptr -> nx_tcp_socket_disconnect_suspended_thread), NX_SUCCESS);
125 }
126
127 /* If given, call the application's disconnect callback function
128 for disconnect. */
129 if (socket_ptr -> nx_tcp_disconnect_callback)
130 {
131
132 /* Call the application's disconnect handling function. It is
133 responsible for calling the socket disconnect function. */
134 (socket_ptr -> nx_tcp_disconnect_callback)(socket_ptr);
135 }
136
137 #ifndef NX_DISABLE_EXTENDED_NOTIFY_SUPPORT
138
139 /* Is a timed wait callback registered for this socket? */
140 if (socket_ptr -> nx_tcp_timed_wait_callback)
141 {
142
143 /* Call the timed wait callback for this socket to let the host
144 know the socket can now be put in the timed wait state (if
145 the RE-USE ADDRESS socket option is not enabled). */
146 (socket_ptr -> nx_tcp_timed_wait_callback)(socket_ptr);
147 }
148
149 /* Is a disconnect complete callback registered with the TCP socket? */
150 if (socket_ptr -> nx_tcp_disconnect_complete_notify)
151 {
152
153 /* Call the application's disconnect_complete callback function. */
154 (socket_ptr -> nx_tcp_disconnect_complete_notify)(socket_ptr);
155 }
156 #endif
157 }
158 else if ((socket_ptr -> nx_tcp_socket_fin_received) &&
159 (socket_ptr -> nx_tcp_socket_fin_sequence == socket_ptr -> nx_tcp_socket_rx_sequence))
160 {
161
162 /* If trace is enabled, insert this event into the trace buffer. */
163 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_CLOSING, NX_TRACE_INTERNAL_EVENTS, 0, 0);
164
165 /* Move to the CLOSING state for simultaneous close situation. */
166 socket_ptr -> nx_tcp_socket_state = NX_TCP_CLOSING;
167
168 /* Send ACK back to the other side of the connection. */
169
170 /* Increment the received sequence number. */
171 socket_ptr -> nx_tcp_socket_rx_sequence++;
172
173 /* Send ACK message. */
174 _nx_tcp_packet_send_ack(socket_ptr, socket_ptr -> nx_tcp_socket_tx_sequence);
175 }
176 }
177
178
