Outline ![]()
Files ![]()
loading...
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
/**************************************************************************/
/* */
/* Copyright (c) Microsoft Corporation. All rights reserved. */
/* */
/* This software is licensed under the Microsoft Software License */
/* Terms for Microsoft Azure RTOS. Full text of the license can be */
/* found in the LICENSE file at https://aka.ms/AzureRTOS_EULA */
/* and in the root directory of this software. */
/* */
/**************************************************************************/
/**************************************************************************/
/**************************************************************************/
/** */
/** NetX Component */
/** */
/** Transmission Control Protocol (TCP) */
/** */
/**************************************************************************/
/**************************************************************************/
#define NX_SOURCE_CODE
/* Include necessary system files. */
#include "nx_api.h"
#include "nx_tcp.h"
#include "nx_packet.h"
#include "nx_ip.h"
#ifdef NX_IPSEC_ENABLE
#include "nx_ipsec.h"
#endif /*NX_IPSEC_ENABLE*/
#ifdef FEATURE_NX_IPV6
#include "nx_ipv6.h"
#endif /* FEATURE_NX_IPV6 */
/**************************************************************************/
/* */
/* FUNCTION RELEASE */
/* */
/* _nx_tcp_no_connection_reset PORTABLE C */
/* 6.1 */
/* AUTHOR */
/* */
/* Yuxin Zhou, Microsoft Corporation */
/* */
/* DESCRIPTION */
/* */
/* This function sends a reset when there is no connection present, */
/* which avoids the timeout processing on the other side of the */
/* connection. */
/* */
/* INPUT */
/* */
/* ip_ptr Pointer to IP control block */
/* packet_ptr Pointer to packet to send */
/* tcp_header_ptr TCP header */
/* */
/* OUTPUT */
/* */
/* None */
/* */
/* CALLS */
/* */
/* _nxd_tcp_no_connect_reset Invokes tcp no conn reset */
/* */
/* CALLED BY */
/* */
/* _nx_tcp_packet_process TCP packet processing */
/* */
/* RELEASE HISTORY */
/* */
/* DATE NAME DESCRIPTION */
/* */
/* 05-19-2020 Yuxin Zhou Initial Version 6.0 */
/* 09-30-2020 Yuxin Zhou Modified comment(s), */
/* resulting in version 6.1 */
/* */
/**************************************************************************/
VOID _nx_tcp_no_connection_reset(NX_IP *ip_ptr, NX_PACKET *packet_ptr, NX_TCP_HEADER *tcp_header_ptr)
{
NX_TCP_SOCKET fake_socket;
ULONG header_length;
#ifdef NX_IPSEC_ENABLE
VOID *sa;
NXD_ADDRESS source_ip;
NXD_ADDRESS destination_ip;
UINT ret;
ULONG data_offset = 0;
#endif /* NX_IPSEC_ENABLE */
/* Clear the fake socket first. */
memset((void *)&fake_socket, 0, sizeof(NX_TCP_SOCKET));
/* Build a fake socket so we can send a reset TCP requests that are not valid. */
fake_socket.nx_tcp_socket_ip_ptr = ip_ptr;
/* Set the connection IP address. */
#ifndef NX_DISABLE_IPV4
if (packet_ptr -> nx_packet_ip_version == NX_IP_VERSION_V4)
{
NX_IPV4_HEADER *ip_header_ptr;
/* Set the IP header. */
/*lint -e{927} -e{826} suppress cast of pointer to pointer, since it is necessary */
ip_header_ptr = (NX_IPV4_HEADER *)packet_ptr -> nx_packet_ip_header;
/* Set the connection ip. */
fake_socket.nx_tcp_socket_connect_ip.nxd_ip_version = NX_IP_VERSION_V4;
fake_socket.nx_tcp_socket_connect_ip.nxd_ip_address.v4 = ip_header_ptr -> nx_ip_header_source_ip;
/* Assume the interface that receives the incoming packet is the best interface
for sending responses. */
fake_socket.nx_tcp_socket_connect_interface = packet_ptr -> nx_packet_address.nx_packet_interface_ptr;
fake_socket.nx_tcp_socket_next_hop_address = NX_NULL;
/* Find the next hop info. */
_nx_ip_route_find(ip_ptr, fake_socket.nx_tcp_socket_connect_ip.nxd_ip_address.v4, &fake_socket.nx_tcp_socket_connect_interface,
&fake_socket.nx_tcp_socket_next_hop_address);
#ifdef NX_IPSEC_ENABLE
/* Get the source ip address. */
source_ip.nxd_ip_version = NX_IP_VERSION_V4;
source_ip.nxd_ip_address.v4 = fake_socket.nx_tcp_socket_connect_interface -> nx_interface_ip_address;
/* Get the destination ip address. */
destination_ip.nxd_ip_version = NX_IP_VERSION_V4;
destination_ip.nxd_ip_address.v4 = ip_header_ptr -> nx_ip_header_source_ip;
#endif /*NX_IPSEC_ENABLE*/
}
#endif /* !NX_DISABLE_IPV4 */
#ifdef FEATURE_NX_IPV6
if (packet_ptr -> nx_packet_ip_version == NX_IP_VERSION_V6)
{
NX_IPV6_HEADER *ipv6_header_ptr;
/* Set the IP header. */
/*lint -e{927} -e{826} suppress cast of pointer to pointer, since it is necessary */
ipv6_header_ptr = (NX_IPV6_HEADER *)packet_ptr -> nx_packet_ip_header;
/* Set the connection ip. */
fake_socket.nx_tcp_socket_connect_ip.nxd_ip_version = NX_IP_VERSION_V6;
COPY_IPV6_ADDRESS(&ipv6_header_ptr -> nx_ip_header_source_ip[0], fake_socket.nx_tcp_socket_connect_ip.nxd_ip_address.v6);
/* Set the outgoing address. */
fake_socket.nx_tcp_socket_ipv6_addr = packet_ptr -> nx_packet_address.nx_packet_ipv6_address_ptr;
/* Set the connect ip interface. */
fake_socket.nx_tcp_socket_connect_interface = packet_ptr -> nx_packet_address.nx_packet_ipv6_address_ptr -> nxd_ipv6_address_attached;
#ifdef NX_IPSEC_ENABLE
/* Get the source ip address. */
source_ip.nxd_ip_version = NX_IP_VERSION_V6;
COPY_IPV6_ADDRESS(fake_socket.nx_tcp_socket_ipv6_addr -> nxd_ipv6_address, source_ip.nxd_ip_address.v6);
/* Get the destination ip address. */
destination_ip.nxd_ip_version = NX_IP_VERSION_V6;
COPY_IPV6_ADDRESS(&ipv6_header_ptr -> nx_ip_header_source_ip[0], destination_ip.nxd_ip_address.v6);
#endif /*NX_IPSEC_ENABLE*/
}
#endif /* FEATURE_NX_IPV6 */
/* Set the source port and destination port. */
fake_socket.nx_tcp_socket_port = (UINT)(tcp_header_ptr -> nx_tcp_header_word_0 & NX_LOWER_16_MASK);
fake_socket.nx_tcp_socket_connect_port = (UINT)(tcp_header_ptr -> nx_tcp_header_word_0 >> NX_SHIFT_BY_16);
/* Set the sequence number only if the incoming segment does not have the ACK flag, according to
Section 3.4, "Reset Generation" on page 37, RFC793. */
if (!(tcp_header_ptr -> nx_tcp_header_word_3 & NX_TCP_ACK_BIT))
{
/* Get the header length. */
header_length = (tcp_header_ptr -> nx_tcp_header_word_3 >> NX_TCP_HEADER_SHIFT) * (ULONG)sizeof(ULONG);
/* Update sequence number to set the reset acknowledge number. */
tcp_header_ptr -> nx_tcp_sequence_number += (packet_ptr -> nx_packet_length - header_length);
/* Check the SYN and FIN bits. */
if (tcp_header_ptr -> nx_tcp_header_word_3 & (NX_TCP_SYN_BIT | NX_TCP_FIN_BIT))
{
/* Update sequence number to set the reset acknowledge number. */
tcp_header_ptr -> nx_tcp_sequence_number++;
}
}
#ifdef NX_IPSEC_ENABLE
/* Check for possible SA match. */
if (ip_ptr -> nx_ip_packet_egress_sa_lookup != NX_NULL) /* IPsec is enabled. */
{
/* If the SA has not been set. */
ret = ip_ptr -> nx_ip_packet_egress_sa_lookup(ip_ptr, /* IP ptr */
&source_ip, /* src_addr */
&destination_ip, /* dest_addr */
NX_PROTOCOL_TCP, /* protocol */
fake_socket.nx_tcp_socket_port, /* src_port */
fake_socket.nx_tcp_socket_connect_port, /* dest_port */
&data_offset, &sa, 0);
if (ret == NX_IPSEC_TRAFFIC_PROTECT)
{
/* Save the SA to the socket. */
fake_socket.nx_tcp_socket_egress_sa = sa;
fake_socket.nx_tcp_socket_egress_sa_data_offset = data_offset;
}
else if (ret == NX_IPSEC_TRAFFIC_DROP || ret == NX_IPSEC_TRAFFIC_PENDING_IKEV2)
{
return;
}
else
{
/* Zero out SA information. */
fake_socket.nx_tcp_socket_egress_sa = NX_NULL;
fake_socket.nx_tcp_socket_egress_sa_data_offset = 0;
}
}
#endif
fake_socket.nx_tcp_socket_time_to_live = (UINT)NX_IP_TIME_TO_LIVE;
/* Send a RST to indicate the connection was not available. */
_nx_tcp_packet_send_rst(&fake_socket, tcp_header_ptr);
}