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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 */
/** */
/** Internet Control Message Protocol (ICMP) */
/** */
/**************************************************************************/
/**************************************************************************/
#define NX_SOURCE_CODE
/* Include necessary system files. */
#include "nx_api.h"
#include "tx_thread.h"
#include "nx_packet.h"
#include "nx_ip.h"
#include "nx_icmp.h"
#ifdef NX_IPSEC_ENABLE
#include "nx_ipsec.h"
#endif /* NX_IPSEC_ENABLE */
#ifndef NX_DISABLE_IPV4
/**************************************************************************/
/* */
/* FUNCTION RELEASE */
/* */
/* _nx_icmpv4_process_echo_reply PORTABLE C */
/* 6.1 */
/* AUTHOR */
/* */
/* Yuxin Zhou, Microsoft Corporation */
/* */
/* DESCRIPTION */
/* */
/* This function processes incoming echo reply message. It matches */
/* the thread that has pending echo request, and unblocks the thread. */
/* */
/* INPUT */
/* */
/* ip_ptr Pointer to IP control block */
/* packet_ptr ICMP packet pointer */
/* */
/* OUTPUT */
/* */
/* None */
/* */
/* CALLS */
/* */
/* _nx_packet_release Release packet back to pool */
/* _tx_thread_system_resume Resume the specified thread */
/* _tx_thread_system_preempt_check Check for preemption */
/* */
/* CALLED BY */
/* */
/* _nx_icmpv4_packet_process Main ICMP packet pocess */
/* */
/* 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_icmpv4_process_echo_reply(NX_IP *ip_ptr, NX_PACKET *packet_ptr)
{
TX_INTERRUPT_SAVE_AREA
TX_THREAD *thread_ptr;
ULONG suspended;
USHORT sequence_num;
NX_ICMPV4_ECHO *echo_ptr;
/* Add debug information. */
NX_PACKET_DEBUG(__FILE__, __LINE__, packet_ptr);
/* Point to the ICMP message header. */
/*lint -e{927} -e{826} suppress cast of pointer to pointer, since it is necessary */
echo_ptr = (NX_ICMPV4_ECHO *)packet_ptr -> nx_packet_prepend_ptr;
#ifndef NX_DISABLE_ICMP_INFO
/* Increment the ICMP responses received count. */
ip_ptr -> nx_ip_ping_responses_received++;
#endif
/* Pickup sequence number. */
sequence_num = echo_ptr -> nx_icmpv4_echo_sequence_num;
/* Convert to host byte order, if little endian taget. */
NX_CHANGE_USHORT_ENDIAN(sequence_num);
/* Disable interrupts. */
TX_DISABLE
/* Pickup the head pointer and the suspended count. */
thread_ptr = ip_ptr -> nx_ip_icmp_ping_suspension_list;
suspended = ip_ptr -> nx_ip_icmp_ping_suspended_count;
/* Temporarily disable preemption. */
_tx_thread_preempt_disable++;
/* Restore interrupts. */
TX_RESTORE
/* Search through the suspended threads waiting for a ECHO (ping) response
in an attempt to find a matching sequence number. */
while (suspended--)
{
/* Determine if the sequence number matches a suspended thread. */
if ((USHORT)(thread_ptr -> tx_thread_suspend_info) == sequence_num)
{
/* Disable interrupts. */
TX_DISABLE
/* See if this is the only suspended thread on the list. */
if (thread_ptr == thread_ptr -> tx_thread_suspended_next)
{
/* Yes, the only suspended thread. */
/* Update the head pointer. */
ip_ptr -> nx_ip_icmp_ping_suspension_list = NX_NULL;
}
else
{
/* At least one more thread is on the same expiration list. */
/* Update the list head pointer. */
if (ip_ptr -> nx_ip_icmp_ping_suspension_list == thread_ptr)
{
ip_ptr -> nx_ip_icmp_ping_suspension_list = thread_ptr -> tx_thread_suspended_next;
}
/* Update the links of the adjacent threads. */
(thread_ptr -> tx_thread_suspended_next) -> tx_thread_suspended_previous =
thread_ptr -> tx_thread_suspended_previous;
(thread_ptr -> tx_thread_suspended_previous) -> tx_thread_suspended_next =
thread_ptr -> tx_thread_suspended_next;
}
/* Decrement the suspension count. */
ip_ptr -> nx_ip_icmp_ping_suspended_count--;
/* Prepare for resumption of the first thread. */
/* Clear cleanup routine to avoid timeout. */
thread_ptr -> tx_thread_suspend_cleanup = TX_NULL;
/* Temporarily disable preemption. */
_tx_thread_preempt_disable++;
/* Restore interrupts. */
TX_RESTORE
/* Adjust this packet to remove the ICMP header that is still in front of
the response message. */
packet_ptr -> nx_packet_length = packet_ptr -> nx_packet_length - (ULONG)sizeof(NX_ICMPV4_ECHO);
packet_ptr -> nx_packet_prepend_ptr = packet_ptr -> nx_packet_prepend_ptr + sizeof(NX_ICMPV4_ECHO);
/* Return this block pointer to the suspended thread waiting for
a block. */
*((NX_PACKET **)thread_ptr -> tx_thread_additional_suspend_info) = packet_ptr;
/* Clear packet pointer so we don't try to release it below. */
packet_ptr = NX_NULL;
/* Put return status into the thread control block. */
thread_ptr -> tx_thread_suspend_status = NX_SUCCESS;
/* Resume thread. */
_tx_thread_system_resume(thread_ptr);
/* Get out of the loop. */
break;
}
else
{
/* Just move to the next suspended thread. */
thread_ptr = thread_ptr -> tx_thread_suspended_next;
}
}
/* Determine if no match was made and we just have to release the packet. */
if (packet_ptr)
{
#ifndef NX_DISABLE_ICMP_INFO
/* Increment the ICMP invalid packet error. */
ip_ptr -> nx_ip_icmp_invalid_packets++;
#endif /* NX_DISABLE_ICMP_INFO */
/* Yes, just release the packet. */
_nx_packet_release(packet_ptr);
}
/* Disable interrupts. */
TX_DISABLE
/* Release preemption disable. */
_tx_thread_preempt_disable--;
/* Restore interrupts. */
TX_RESTORE
/* Check for preemption. */
_tx_thread_system_preempt_check();
}
#endif /* !NX_DISABLE_IPV4 */