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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 Protocol (IP) */
/** */
/**************************************************************************/
/**************************************************************************/
#define NX_SOURCE_CODE
/* Include necessary system files. */
#include "nx_api.h"
#include "nx_ip.h"
#include "nx_packet.h"
#include "nx_icmpv4.h"
#ifndef NX_DISABLE_IPV4
/**************************************************************************/
/* */
/* FUNCTION RELEASE */
/* */
/* _nx_ipv4_option_process PORTABLE C */
/* 6.1 */
/* AUTHOR */
/* */
/* Yuxin Zhou, Microsoft Corporation */
/* */
/* DESCRIPTION */
/* */
/* This function goes through IPv4 option fields. */
/* */
/* INPUT */
/* */
/* ip_ptr Pointer to IP control block */
/* packet_ptr Pointer to packet to send */
/* */
/* OUTPUT */
/* */
/* None */
/* */
/* CALLS */
/* */
/* */
/* CALLED BY */
/* */
/* _nx_ipv4_packet_receive Main IPv4 packet receive */
/* */
/* 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_ipv4_option_process(NX_IP *ip_ptr, NX_PACKET *packet_ptr)
{
NX_IPV4_HEADER *ip_header_ptr;
UCHAR *option_ptr;
ULONG ip_option_length;
#ifndef NX_DISABLE_ICMPV4_ERROR_MESSAGE
ULONG ip_normal_length = 20;
#endif /* NX_DISABLE_ICMPV4_ERROR_MESSAGE */
UINT index = 0;
UCHAR op_type;
UCHAR op_length;
UCHAR op_timestamp_offset;
UCHAR op_timestamp_overflow;
UCHAR op_timestamp_flags;
UINT op_timestamp_counter = 0;
/* Set the IPv4 header and IPv4 option pointer. */
/*lint -e{927} -e{826} suppress cast of pointer to pointer, since it is necessary */
ip_header_ptr = (NX_IPV4_HEADER *)(packet_ptr -> nx_packet_prepend_ptr);
option_ptr = packet_ptr -> nx_packet_prepend_ptr + sizeof(NX_IPV4_HEADER);
/* Calculate the IPv4 option length. */
ip_option_length = ((((ip_header_ptr -> nx_ip_header_word_0 & NX_IP_LENGTH_MASK) >> 24) - NX_IP_NORMAL_LENGTH) & 0xFF) * (ULONG)sizeof(ULONG);
/* Loop to process the IPv4 option. */
while (index < ip_option_length)
{
/* Get the option type. */
op_type = *option_ptr;
/* Process the option type. */
switch (op_type)
{
case NX_IP_OPTION_END:
{
/* End option. */
return(NX_TRUE);
}
case NX_IP_OPTION_NO_OPERATION:
{
/* No opeartion. */
/* Update the Option pointer and index. */
option_ptr++;
index++;
continue;
}
case NX_IP_OPTION_INTERNET_TIMESTAMP:
{
/* Timestamp option. RFC781. */
/* Update the counter; */
op_timestamp_counter++;
/* Check the counter. */
if (op_timestamp_counter > 1)
{
#ifndef NX_DISABLE_ICMPV4_ERROR_MESSAGE
/* Option length error, send a Parameter Problem Message . */
/*lint -e{835} -e{845} suppress operating on zero. */
NX_ICMPV4_SEND_PARAMETER_PROBLEM(ip_ptr, packet_ptr, NX_ICMP_ZERO_CODE, (ip_normal_length + index + 2));
#endif
/* Return NX_FALSE. */
return(NX_FALSE);
}
/* Get the option length. */
op_length = *(option_ptr + 1);
/* Get the option offset. */
op_timestamp_offset = *(option_ptr + 2);
/* Get the option overflow and flag. */
op_timestamp_overflow = (*(option_ptr + 3)) >> 4;
op_timestamp_flags = (*(option_ptr + 3)) & 0xF;
/* Only check the option errors. */
/* Check the option length error. */
if ((op_length < 8) || (op_length > 40) || ((op_length % 4) != 0))
{
#ifndef NX_DISABLE_ICMPV4_ERROR_MESSAGE
/* Option length error, send a Parameter Problem Message . */
/*lint -e{835} -e{845} suppress operating on zero. */
NX_ICMPV4_SEND_PARAMETER_PROBLEM(ip_ptr, packet_ptr, NX_ICMP_ZERO_CODE, (ip_normal_length + index + 2));
#endif
/* Return NX_FALSE. */
return(NX_FALSE);
}
/* Check the option offset error, offset must be greater than 5, and offset must be an odd number. */
if ((op_timestamp_offset < 5) || ((op_timestamp_offset % 2) == 0))
{
#ifndef NX_DISABLE_ICMPV4_ERROR_MESSAGE
/* Option offset error, send a Parameter Problem Message . */
/*lint -e{835} -e{845} suppress operating on zero. */
NX_ICMPV4_SEND_PARAMETER_PROBLEM(ip_ptr, packet_ptr, NX_ICMP_ZERO_CODE, (ip_normal_length + index + 3));
#endif
/* Return NX_FALSE. */
return(NX_FALSE);
}
/* Check the option overflow error. */
if (op_timestamp_overflow == 15)
{
#ifndef NX_DISABLE_ICMPV4_ERROR_MESSAGE
/* Option overflow error, send a Parameter Problem Message . */
/*lint -e{835} -e{845} suppress operating on zero. */
NX_ICMPV4_SEND_PARAMETER_PROBLEM(ip_ptr, packet_ptr, NX_ICMP_ZERO_CODE, (ip_normal_length + index + 4));
#endif
/* Return NX_FALSE. */
return(NX_FALSE);
}
/* Check the option flags error. */
if ((op_timestamp_flags != 0) && (op_timestamp_flags != 1) && (op_timestamp_flags != 3))
{
#ifndef NX_DISABLE_ICMPV4_ERROR_MESSAGE
/* Option flags error, send a Parameter Problem Message . */
/*lint -e{835} -e{845} suppress operating on zero. */
NX_ICMPV4_SEND_PARAMETER_PROBLEM(ip_ptr, packet_ptr, NX_ICMP_ZERO_CODE, (ip_normal_length + index + 4));
#endif
/* Return NX_FALSE. */
return(NX_FALSE);
}
break;
}
default:
break;
}
/* Get the option length. */
op_length = *(option_ptr + 1);
/* Check for invalid option length.
RFC 791: The option-length octet counts the option-type octet and the
option-length octet as well as the option-data octets. */
if ((op_length < 2) || ((index + op_length) > ip_option_length))
{
return(NX_FALSE);
}
/* Move to the next top level option. */
option_ptr += op_length;
/* Update the index. */
index += op_length;
}
/* Return NX_TRUE. */
return(NX_TRUE);
}
#endif /* !NX_DISABLE_IPV4 */