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/**************************************************************************/
/* */
/* 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 */
/** */
/** Reverse Address Resolution Protocol (RARP) */
/** */
/**************************************************************************/
/**************************************************************************/
#define NX_SOURCE_CODE
/* Include necessary system files. */
#include "nx_api.h"
#include "nx_rarp.h"
#include "nx_packet.h"
#ifndef NX_DISABLE_IPV4
/**************************************************************************/
/* */
/* FUNCTION RELEASE */
/* */
/* _nx_rarp_packet_receive PORTABLE C */
/* 6.1 */
/* AUTHOR */
/* */
/* Yuxin Zhou, Microsoft Corporation */
/* */
/* DESCRIPTION */
/* */
/* This function processes the reception of both the RARP request and */
/* the RARP response. RARP responses received are used to setup the */
/* the IP address of this IP instance. Once the IP address is setup, */
/* RARP is automatically disabled. RARP requests are discarded */
/* at present time. */
/* */
/* INPUT */
/* */
/* ip_ptr Pointer to IP instance */
/* packet_ptr Received RARP packet */
/* */
/* OUTPUT */
/* */
/* None */
/* */
/* CALLS */
/* */
/* _nx_packet_release Release the RARP request */
/* */
/* CALLED BY */
/* */
/* _nx_rarp_queue_process RARP receive queue 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_rarp_packet_receive(NX_IP *ip_ptr, NX_PACKET *packet_ptr)
{
TX_INTERRUPT_SAVE_AREA
ULONG *message_ptr;
UINT i;
VOID (*address_change_notify)(NX_IP *, VOID *) = NX_NULL;
VOID *additional_info = NX_NULL;
#ifndef NX_DISABLE_RX_SIZE_CHECKING
/* Determine if the packet length is valid. */
if (packet_ptr -> nx_packet_length < NX_RARP_MESSAGE_SIZE)
{
#ifndef NX_DISABLE_RARP_INFO
/* Increment the RARP invalid messages count... At least until RARP server
logic is added. */
ip_ptr -> nx_ip_rarp_invalid_messages++;
#endif
/* Just release the packet. */
_nx_packet_release(packet_ptr);
/* Return to caller. */
return;
}
#endif /* NX_DISABLE_RX_SIZE_CHECKING */
/* Setup a pointer to the RARP message. */
/*lint -e{927} -e{826} suppress cast of pointer to pointer, since it is necessary */
message_ptr = (ULONG *)packet_ptr -> nx_packet_prepend_ptr;
/* Endian swapping logic. If NX_LITTLE_ENDIAN is specified, these macros will
swap the endian of the RARP message. */
NX_CHANGE_ULONG_ENDIAN(*(message_ptr + 1));
NX_CHANGE_ULONG_ENDIAN(*(message_ptr + 2));
NX_CHANGE_ULONG_ENDIAN(*(message_ptr + 3));
NX_CHANGE_ULONG_ENDIAN(*(message_ptr + 4));
NX_CHANGE_ULONG_ENDIAN(*(message_ptr + 5));
NX_CHANGE_ULONG_ENDIAN(*(message_ptr + 6));
/* If trace is enabled, insert this event into the trace buffer. */
NX_TRACE_IN_LINE_INSERT(NX_TRACE_INTERNAL_RARP_RECEIVE, ip_ptr, *(message_ptr + 6), packet_ptr, *(message_ptr + 1), NX_TRACE_INTERNAL_EVENTS, 0, 0);
/* Determine what type of RARP message this is. Note that RARP requests must
also specify this IP instance's IP address. */
if ((*(message_ptr + 1) & 0xFFFF) == NX_RARP_OPTION_REQUEST)
{
#ifndef NX_DISABLE_RARP_INFO
/* Increment the RARP invalid messages count... At least until RARP server
logic is added. */
ip_ptr -> nx_ip_rarp_invalid_messages++;
#endif
/* Just release the packet. */
_nx_packet_release(packet_ptr);
}
else if ((*(message_ptr + 1) & 0xFFFF) == NX_RARP_OPTION_RESPONSE)
{
/* We have a response to a previous RARP request. */
#ifndef NX_DISABLE_ARP_INFO
/* Increment the RARP responses received count. */
ip_ptr -> nx_ip_rarp_responses_received++;
#endif
/* Disable Interrupts. */
TX_DISABLE
/* Determine if the target IP address is non-zero. */
if (*(message_ptr + 6) && (packet_ptr -> nx_packet_address.nx_packet_interface_ptr -> nx_interface_ip_address == 0))
{
/* Pickup the current notification callback and additional information pointers. */
address_change_notify = ip_ptr -> nx_ip_address_change_notify;
additional_info = ip_ptr -> nx_ip_address_change_notify_additional_info;
/* Set the IP address of this IP instance to the target
IP address in the RARP response. */
packet_ptr -> nx_packet_address.nx_packet_interface_ptr -> nx_interface_ip_address = *(message_ptr + 6);
/* Loop through all the interfaces and check whether or not to continue periodic RARP requests. */
for (i = 0; i < NX_MAX_PHYSICAL_INTERFACES; i++)
{
/* Skip the invalid interface entry. */
if (ip_ptr -> nx_ip_interface[i].nx_interface_valid == 0)
{
continue;
}
/* Look for any interfaces still without a valid IP address. */
if ((ip_ptr -> nx_ip_interface[i].nx_interface_ip_address == 0) &&
(ip_ptr -> nx_ip_interface[i].nx_interface_address_mapping_needed == NX_TRUE))
{
/* At least one interface still has non-zero IP address. Continue RARP process. */
break;
}
}
/* Do we need to continue with periodic RARP requests? */
if (i >= NX_MAX_PHYSICAL_INTERFACES)
{
/* No, Disable the RARP activity now that we have a valid IP address. */
ip_ptr -> nx_ip_rarp_periodic_update = NX_NULL;
ip_ptr -> nx_ip_rarp_queue_process = NX_NULL;
}
}
/* Restore interrupts. */
TX_RESTORE
/* Release the RARP response packet. */
_nx_packet_release(packet_ptr);
}
else
{
#ifndef NX_DISABLE_RARP_INFO
/* Increment the RARP invalid messages count. */
ip_ptr -> nx_ip_rarp_invalid_messages++;
#endif
/* Invalid RARP message. Just release the packet. */
_nx_packet_release(packet_ptr);
}
/* Determine if the application should be notified of the IP address change. */
if (address_change_notify != NX_NULL)
{
/* Yes, call the application's IP address change notify function. */
(address_change_notify)(ip_ptr, additional_info);
}
return;
}
#endif /* !NX_DISABLE_IPV4 */