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 /** Packet Pool Management (Packet) */
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_packet.h"
30
31
32 /**************************************************************************/
33 /* */
34 /* FUNCTION RELEASE */
35 /* */
36 /* _nx_packet_data_retrieve PORTABLE C */
37 /* 6.1 */
38 /* AUTHOR */
39 /* */
40 /* Yuxin Zhou, Microsoft Corporation */
41 /* */
42 /* DESCRIPTION */
43 /* */
44 /* This function copies data from a NetX packet (or packet chain) into */
45 /* the supplied user buffer. */
46 /* */
47 /* INPUT */
48 /* */
49 /* packet_ptr Pointer to the source packet */
50 /* buffer_start Pointer to destination area */
51 /* bytes_copied Number of bytes copied */
52 /* */
53 /* OUTPUT */
54 /* */
55 /* status Completion status */
56 /* */
57 /* CALLS */
58 /* */
59 /* None */
60 /* */
61 /* CALLED BY */
62 /* */
63 /* Application Code */
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), and */
71 /* verified memcpy use cases, */
72 /* resulting in version 6.1 */
73 /* */
74 /**************************************************************************/
_nx_packet_data_retrieve(NX_PACKET * packet_ptr,VOID * buffer_start,ULONG * bytes_copied)75 UINT _nx_packet_data_retrieve(NX_PACKET *packet_ptr, VOID *buffer_start, ULONG *bytes_copied)
76 {
77
78 ULONG remaining_bytes;
79 UCHAR *destination_ptr;
80 ULONG bytes_to_copy;
81
82 /* If trace is enabled, insert this event into the trace buffer. */
83 NX_TRACE_IN_LINE_INSERT(NX_TRACE_PACKET_DATA_RETRIEVE, packet_ptr, buffer_start, bytes_copied, 0, NX_TRACE_PACKET_EVENTS, 0, 0);
84
85 /* Setup the destination pointer. */
86 destination_ptr = buffer_start;
87
88 /* Pickup the amount of bytes to copy. */
89 *bytes_copied = packet_ptr -> nx_packet_length;
90
91 /* Setup the remaining bytes. */
92 remaining_bytes = packet_ptr -> nx_packet_length;
93
94 #ifndef NX_DISABLE_PACKET_CHAIN
95 /* Loop to copy bytes from packet(s). */
96 while (packet_ptr)
97 {
98 #endif /* NX_DISABLE_PACKET_CHAIN */
99
100 /* Calculate the bytes to copy in this packet. */
101 /*lint -e{946} -e{947} suppress pointer subtraction, since it is necessary. */
102 bytes_to_copy = (ULONG)(packet_ptr -> nx_packet_append_ptr - packet_ptr -> nx_packet_prepend_ptr);
103
104 /* Copy data to destination. */
105 /* Note: The buffer size must be not less than packet_ptr -> nx_packet_length. */
106 memcpy(destination_ptr, packet_ptr -> nx_packet_prepend_ptr, bytes_to_copy); /* Use case of memcpy is verified. The buffer is provided by user. lgtm[cpp/banned-api-usage-required-any] */
107
108 remaining_bytes -= bytes_to_copy;
109 destination_ptr += bytes_to_copy;
110
111 #ifndef NX_DISABLE_PACKET_CHAIN
112 /* Move to next packet. */
113 packet_ptr = packet_ptr -> nx_packet_next;
114 }
115 #endif /* NX_DISABLE_PACKET_CHAIN */
116
117 /* Determine if the packet chain was valid. */
118 if (remaining_bytes)
119 {
120
121 /* Invalid packet chain. Calculate the actual number of bytes
122 copied. */
123 *bytes_copied = *bytes_copied - remaining_bytes;
124
125 /* Return an error. */
126 return(NX_INVALID_PACKET);
127 }
128
129 /* Return successful completion. */
130 return(NX_SUCCESS);
131 }
132
133
