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
|
/*
LUFA Library
Copyright (C) Dean Camera, 2009.
dean [at] fourwalledcubicle [dot] com
www.fourwalledcubicle.com
*/
/*
Copyright 2009 Dean Camera (dean [at] fourwalledcubicle [dot] com)
Permission to use, copy, modify, and distribute this software
and its documentation for any purpose and without fee is hereby
granted, provided that the above copyright notice appear in all
copies and that both that the copyright notice and this
permission notice and warranty disclaimer appear in supporting
documentation, and that the name of the author not be used in
advertising or publicity pertaining to distribution of the
software without specific, written prior permission.
The author disclaim all warranties with regard to this
software, including all implied warranties of merchantability
and fitness. In no event shall the author be liable for any
special, indirect or consequential damages or any damages
whatsoever resulting from loss of use, data or profits, whether
in an action of contract, negligence or other tortious action,
arising out of or in connection with the use or performance of
this software.
*/
/** \file
*
* User Datagram Protocol (UDP) packet handling routines. This protocol handles high throughput, low
* reliability packets which are typically used to encapsulate streaming data.
*/
#define INCLUDE_FROM_UDP_C
#include "UDP.h"
/** Processes a UDP packet inside an Ethernet frame, and writes the appropriate response
* to the output Ethernet frame if a subprotocol handler has created a response packet.
*
* \param IPHeaderInStart Pointer to the start of the incoming packet's IP header
* \param UDPHeaderInStart Pointer to the start of the incoming packet's UDP header
* \param UDPHeaderOutStart Pointer to the start of the outgoing packet's UDP header
*
* \return The number of bytes written to the out Ethernet frame if any, NO_RESPONSE otherwise
*/
int16_t UDP_ProcessUDPPacket(void* IPHeaderInStart, void* UDPHeaderInStart, void* UDPHeaderOutStart)
{
UDP_Header_t* UDPHeaderIN = (UDP_Header_t*)UDPHeaderInStart;
UDP_Header_t* UDPHeaderOUT = (UDP_Header_t*)UDPHeaderOutStart;
int16_t RetSize = NO_RESPONSE;
DecodeUDPHeader(UDPHeaderInStart);
/* Check to see if the UDP packet is a DHCP packet */
if (SwapEndian_16(UDPHeaderIN->DestinationPort) == UDP_PORT_DHCP_REQUEST)
{
RetSize = DHCP_ProcessDHCPPacket(IPHeaderInStart,
&((uint8_t*)UDPHeaderInStart)[sizeof(UDP_Header_t)],
&((uint8_t*)UDPHeaderOutStart)[sizeof(UDP_Header_t)]);
}
/* Check to see if the protocol processing routine has filled out a response */
if (RetSize > 0)
{
/* Fill out the response UDP packet header */
UDPHeaderOUT->SourcePort = UDPHeaderIN->DestinationPort;
UDPHeaderOUT->DestinationPort = UDPHeaderIN->SourcePort;
UDPHeaderOUT->Checksum = 0;
UDPHeaderOUT->Length = SwapEndian_16(sizeof(UDP_Header_t) + RetSize);
/* Return the size of the response so far */
return (sizeof(UDP_Header_t) + RetSize);
}
return NO_RESPONSE;
}
|
