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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 */
/** */
/** Address Resolution Protocol (ARP) */
/** */
/**************************************************************************/
/**************************************************************************/
#define NX_SOURCE_CODE
/* Include necessary system files. */
#include "nx_api.h"
#include "nx_arp.h"
/**************************************************************************/
/* */
/* FUNCTION RELEASE */
/* */
/* _nx_arp_entry_delete PORTABLE C */
/* 6.1 */
/* AUTHOR */
/* */
/* Yuxin Zhou, Microsoft Corporation */
/* */
/* DESCRIPTION */
/* */
/* This function searches for the specified IP address in the ARP */
/* lists. If found, the associated ARP entry is deleted. */
/* */
/* INPUT */
/* */
/* ip_ptr IP instance pointer */
/* ip_address IP Address to search for */
/* */
/* OUTPUT */
/* */
/* status Completion status */
/* */
/* CALLS */
/* */
/* tx_mutex_get Obtain protection mutex */
/* tx_mutex_put Release protection mutex */
/* _nx_arp_static_entry_delete Remove static ARP entry */
/* _nx_arp_dynamic_entry_delete Remove dynamic ARP entry */
/* */
/* CALLED BY */
/* */
/* Application Code */
/* */
/* 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 */
/* */
/**************************************************************************/
UINT _nx_arp_entry_delete(NX_IP *ip_ptr, ULONG ip_address)
{
#ifndef NX_DISABLE_IPV4
UINT status;
NX_ARP *arp_ptr;
NX_ARP *arp_list_head;
NX_ARP *search_ptr;
UINT index;
/* Obtain protection on this IP instance for access into the ARP static list. */
tx_mutex_get(&(ip_ptr -> nx_ip_protection), TX_WAIT_FOREVER);
/* Search the static list for a matching IP and hardware mapping.
Compute the index that will tell us which linked list of ARP addresses to search,
since we don't care if it is a static or dynamic entry.
Search that linked list pointed in the IP ARP table. */
/* Calculate the hash index for the specified IP address. */
index = (UINT)((ip_address + (ip_address >> 8)) & NX_ARP_TABLE_MASK);
/* Pickup the head pointer of the ARP entries for this IP instance. */
arp_list_head = ip_ptr -> nx_ip_arp_table[index];
/* Search the ARP list for the same IP address. */
search_ptr = arp_list_head;
arp_ptr = NX_NULL;
while (search_ptr)
{
/* Determine if we have a match. */
if (search_ptr -> nx_arp_ip_address == ip_address)
{
/* Yes, the IP address matches, setup the ARP entry pointer. */
arp_ptr = search_ptr;
/* Get out of the loop. */
break;
}
/* Move to the next entry in the active list. */
search_ptr = search_ptr -> nx_arp_active_next;
/* Determine if the search pointer is back at the head of
the list. */
if (search_ptr == arp_list_head)
{
/* End of the ARP list, end the search. */
break;
}
}
/* Determine if we didn't find an ARP entry matching the input IP address. */
if (arp_ptr == NX_NULL)
{
/* Release the protection on the ARP list. */
tx_mutex_put(&(ip_ptr -> nx_ip_protection));
/* Return status to the caller. */
return(NX_ENTRY_NOT_FOUND);
}
/* Determine if this is a static entry. */
if (arp_ptr -> nx_arp_route_static == NX_TRUE)
{
/* Remove from the static list. */
status = _nx_arp_static_entry_delete(ip_ptr, ip_address,
arp_ptr -> nx_arp_physical_address_msw,
arp_ptr -> nx_arp_physical_address_lsw);
}
else
{
/* Remove from the dynamic list. */
status = _nx_arp_dynamic_entry_delete(ip_ptr, arp_ptr);
}
/* Release the protection on the ARP list. */
tx_mutex_put(&(ip_ptr -> nx_ip_protection));
/* Return status to the caller. */
return(status);
#else /* NX_DISABLE_IPV4 */
NX_PARAMETER_NOT_USED(ip_ptr);
NX_PARAMETER_NOT_USED(ip_address);
return(NX_NOT_SUPPORTED);
#endif /* !NX_DISABLE_IPV4 */
}