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
|
/***************************************************************************
* Copyright (c) 2024 Microsoft Corporation
* Copyright (c) 2025-present Eclipse ThreadX Contributors
*
* This program and the accompanying materials are made available under the
* terms of the MIT License which is available at
* https://opensource.org/licenses/MIT.
*
* SPDX-License-Identifier: MIT
**************************************************************************/
/**************************************************************************/
/**************************************************************************/
/** */
/** NetX Component */
/** */
/** Internet Protocol (IP) */
/** */
/**************************************************************************/
/**************************************************************************/
#define NX_SOURCE_CODE
/* Include necessary system files. */
#include "nx_api.h"
#include "nx_ip.h"
#include "nx_ipv6.h"
#include "nx_packet.h"
#include "nx_icmpv6.h"
#if defined(FEATURE_NX_IPV6) && !defined(NX_DISABLE_FRAGMENTATION)
/**************************************************************************/
/* */
/* FUNCTION RELEASE */
/* */
/* _nx_ipv6_process_fragment_option PORTABLE C */
/* 6.4.3 */
/* AUTHOR */
/* */
/* Yuxin Zhou, Microsoft Corporation */
/* */
/* DESCRIPTION */
/* */
/* This function processes the IPv6 Fragmentation Option header. */
/* */
/* INPUT */
/* */
/* ip_ptr Pointer to IP control block */
/* packet_ptr Pointer to packet to process */
/* */
/* OUTPUT */
/* */
/* NX_SUCCESS Successful completion */
/* NX_CONTINUE Continue processing */
/* NX_OPTION_HEADER_ERROR Error with fragment option */
/* */
/* CALLS */
/* */
/* _nx_ip_dispatch_process Process IPv6 optional headers */
/* NX_ICMPV6_SEND_PARAMETER_PROBLEM Report IPv6 errors via ICMP */
/* message */
/* tx_event_flags_set Wake up the IP helper thread */
/* */
/* CALLED BY */
/* */
/* _nx_ip_dispatch_process Process IPv6 optional header */
/* */
/**************************************************************************/
UINT _nx_ipv6_process_fragment_option(NX_IP *ip_ptr, NX_PACKET *packet_ptr)
{
TX_INTERRUPT_SAVE_AREA
NX_IPV6_HEADER_FRAGMENT_OPTION *fragment_option;
/* Add debug information. */
NX_PACKET_DEBUG(__FILE__, __LINE__, packet_ptr);
#ifndef NX_DISABLE_IP_INFO
/* Increment the IP receive fragments count */
ip_ptr -> nx_ip_total_fragments_received++;
#endif /* NX_DISABLE_IP_INFO */
/* If fragmentation is not enabled, we drop this packet. */
if (!ip_ptr -> nx_ip_fragment_assembly)
{
return(NX_OPTION_HEADER_ERROR);
}
/* Check packet length is at least sizeof(NX_IPV6_HEADER_FRAGMENT_OPTION). */
if (packet_ptr -> nx_packet_length < sizeof(NX_IPV6_HEADER_FRAGMENT_OPTION))
{
return(NX_OPTION_HEADER_ERROR);
}
/* Set a pointer to the starting of the fragment option. */
/*lint -e{927} -e{826} suppress cast of pointer to pointer, since it is necessary */
fragment_option = (NX_IPV6_HEADER_FRAGMENT_OPTION *)packet_ptr -> nx_packet_prepend_ptr;
/* Byte swap the offset_flag. The identification field is only used for checking matches.
The absolute value of the Id is not used in arithmatic operations. Therefore there is
need to byte-swap this field. */
NX_CHANGE_USHORT_ENDIAN(fragment_option -> nx_ipv6_header_fragment_option_offset_flag);
/* Check whether or not the payload size is not multiple of 8 bytes if the
M bit is set. */
if (fragment_option -> nx_ipv6_header_fragment_option_offset_flag & 0x0001) /* M bit is set */
{
NX_IPV6_HEADER *ip_header;
ULONG payload_length;
/*lint -e{927} -e{826} suppress cast of pointer to pointer, since it is necessary */
ip_header = (NX_IPV6_HEADER *)packet_ptr -> nx_packet_ip_header;
payload_length = ip_header -> nx_ip_header_word_1 >> 16;
/* If not multiple of 8 bytes... */
if ((payload_length & 0xFFF8) != payload_length)
{
/* Return the option header error status and abort. */
#ifndef NX_DISABLE_ICMPV6_ERROR_MESSAGE
/* Cover offset flag field. */
NX_CHANGE_USHORT_ENDIAN(fragment_option -> nx_ipv6_header_fragment_option_offset_flag);
/*lint -e{835} -e{845} suppress operating on zero. */
NX_ICMPV6_SEND_PARAMETER_PROBLEM(ip_ptr, packet_ptr, 0, 4);
#endif
return(NX_OPTION_HEADER_ERROR);
}
}
/* M bit is clear: This is the last (tail) packet fragment. */
else if ((fragment_option -> nx_ipv6_header_fragment_option_offset_flag & 0xFFF8) == 0)
{
/* Continue processing. */
return(NX_CONTINUE);
}
/* Payload size cannot exceeding 65535. */
if (((fragment_option -> nx_ipv6_header_fragment_option_offset_flag & 0xFFF8) + packet_ptr -> nx_packet_length -
sizeof(NX_IPV6_HEADER_FRAGMENT_OPTION)) > 65535)
{
#ifndef NX_DISABLE_ICMPV6_ERROR_MESSAGE
/* Cover offset flag field. */
NX_CHANGE_USHORT_ENDIAN(fragment_option -> nx_ipv6_header_fragment_option_offset_flag);
/*lint -e{946} -e{947} suppress pointer subtraction, since it is necessary. */
/*lint -e{835} -e{845} suppress operating on zero. */
NX_ICMPV6_SEND_PARAMETER_PROBLEM(ip_ptr, packet_ptr, 0,
(ULONG)((packet_ptr -> nx_packet_prepend_ptr - packet_ptr -> nx_packet_ip_header) + 2));
#endif /* NX_DISABLE_ICMPV6_ERROR_MESSAGE */
/* Return an Option header error status. */
return(NX_OPTION_HEADER_ERROR);
}
/* Disable interrupt */
TX_DISABLE
/* In IPv6 IP fragmentation is required. */
/* Determine if the queue is empty. */
if (ip_ptr -> nx_ip_received_fragment_head)
{
/* Raw receive queue is not empty, add this packet to the end of the queue. */
(ip_ptr -> nx_ip_received_fragment_tail) -> nx_packet_queue_next = packet_ptr;
packet_ptr -> nx_packet_queue_next = NX_NULL;
ip_ptr -> nx_ip_received_fragment_tail = packet_ptr;
}
else
{
/* Raw receive queue is empty. Just set the head and tail pointers
to point to this packet. */
ip_ptr -> nx_ip_received_fragment_head = packet_ptr;
ip_ptr -> nx_ip_received_fragment_tail = packet_ptr;
packet_ptr -> nx_packet_queue_next = NX_NULL;
}
/* Add debug information. */
NX_PACKET_DEBUG(NX_PACKET_IP_FRAGMENT_QUEUE, __LINE__, packet_ptr);
/* Restore interrupts. */
TX_RESTORE
#ifndef NX_FRAGMENT_IMMEDIATE_ASSEMBLY
/* Wakeup IP helper thread to process the IP fragment re-assembly. */
tx_event_flags_set(&(ip_ptr -> nx_ip_events), NX_IP_UNFRAG_EVENT, TX_OR);
#else
/* Process the IP fragment reassemble. */
(ip_ptr -> nx_ip_fragment_assembly)(ip_ptr);
#endif /* NX_FRAGMENT_IMMEDIATE_ASSEMBLY */
return(NX_SUCCESS);
}
#endif /* FEATURE_NX_IPV6 && NX_DISABLE_FRAGMENTATION*/
|
