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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_hardware_address_find 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 hardware address is returned. */
/* */
/* INPUT */
/* */
/* ip_ptr IP instance pointer */
/* ip_address IP Address to search for */
/* physical_msw Physical address MSW pointer */
/* physical_lsw Physical address LSW pointer */
/* */
/* OUTPUT */
/* */
/* status Completion status */
/* */
/* CALLS */
/* */
/* tx_mutex_get Obtain protection mutex */
/* tx_mutex_put Release protection mutex */
/* */
/* 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_hardware_address_find(NX_IP *ip_ptr, ULONG ip_address,
ULONG *physical_msw, ULONG *physical_lsw)
{
#ifndef NX_DISABLE_IPV4
NX_ARP *arp_entry;
ULONG count;
#ifdef TX_ENABLE_EVENT_TRACE
TX_TRACE_BUFFER_ENTRY *trace_event;
ULONG trace_timestamp;
#endif
/* If trace is enabled, insert this event into the trace buffer. */
NX_TRACE_IN_LINE_INSERT(NX_TRACE_ARP_HARDWARE_ADDRESS_FIND, ip_ptr, ip_address, 0, 0, NX_TRACE_ARP_EVENTS, &trace_event, &trace_timestamp);
/* 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. */
arp_entry = ip_ptr -> nx_ip_arp_static_list;
while (arp_entry)
{
/* Determine if we have a match. */
if ((arp_entry -> nx_arp_ip_address == ip_address) &&
(arp_entry -> nx_arp_physical_address_msw | arp_entry -> nx_arp_physical_address_lsw))
{
/* Yes, we have found the ARP entry we are looking for. */
break;
}
else
{
/* Determine if we are at the end of the list. */
if (arp_entry -> nx_arp_pool_next == ip_ptr -> nx_ip_arp_static_list)
{
/* Set the arp_entry to NULL to signify nothing was found and get
out of the search loop. */
arp_entry = NX_NULL;
break;
}
else
{
/* Just move to the next ARP entry on the static list. */
arp_entry = arp_entry -> nx_arp_pool_next;
}
}
}
/* Determine if an entry has been found. If so, we are finished and it needs to be
returned to the caller. */
if (arp_entry)
{
/* Store the hardware address in the return fields. */
*physical_msw = arp_entry -> nx_arp_physical_address_msw;
*physical_lsw = arp_entry -> nx_arp_physical_address_lsw;
/* Update the trace event with the status. */
NX_TRACE_EVENT_UPDATE(trace_event, trace_timestamp, NX_TRACE_ARP_HARDWARE_ADDRESS_FIND, 0, 0, *physical_msw, *physical_lsw);
/* Release the protection on the ARP list. */
tx_mutex_put(&(ip_ptr -> nx_ip_protection));
/* Return status to the caller. */
return(NX_SUCCESS);
}
/* Otherwise, we need to search the ARP dynamic list for a match. */
arp_entry = ip_ptr -> nx_ip_arp_dynamic_list;
count = 1;
while (arp_entry)
{
/* Determine if we have a match. */
if ((arp_entry -> nx_arp_ip_address == ip_address) &&
(arp_entry -> nx_arp_physical_address_msw | arp_entry -> nx_arp_physical_address_lsw))
{
/* Yes, we have found the ARP entry we are looking for. */
break;
}
else
{
/* Determine if we are at the end of the list of active ARP entries. */
if (count >= ip_ptr -> nx_ip_arp_dynamic_active_count)
{
/* Set the arp_entry to NULL to signify nothing was found and get
out of the search loop. */
arp_entry = NX_NULL;
break;
}
else
{
/* Just move to the next ARP entry on the dynamic list. */
arp_entry = arp_entry -> nx_arp_pool_next;
/* Increment the active count. */
count++;
}
}
}
/* Determine if an entry has been found. If so, we are finished and it needs to be
returned to the caller. */
if (arp_entry)
{
/* Store the hardware address in the return fields. */
*physical_msw = arp_entry -> nx_arp_physical_address_msw;
*physical_lsw = arp_entry -> nx_arp_physical_address_lsw;
/* Update the trace event with the status. */
NX_TRACE_EVENT_UPDATE(trace_event, trace_timestamp, NX_TRACE_ARP_HARDWARE_ADDRESS_FIND, 0, 0, *physical_msw, *physical_lsw);
/* Release the protection on the ARP list. */
tx_mutex_put(&(ip_ptr -> nx_ip_protection));
/* Return status to the caller. */
return(NX_SUCCESS);
}
else
{
/* 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);
}
#else /* NX_DISABLE_IPV4 */
NX_PARAMETER_NOT_USED(ip_ptr);
NX_PARAMETER_NOT_USED(ip_address);
NX_PARAMETER_NOT_USED(physical_msw);
NX_PARAMETER_NOT_USED(physical_lsw);
return(NX_NOT_SUPPORTED);
#endif /* !NX_DISABLE_IPV4 */
}