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/***************************************************************************/
/* Copyright (c) 2024 Microsoft Corporation */
/* Copyright (c) 2026 Eclipse ThreadX contributors */
/* */
/* This program and the accompanying materials are made available under */
/* the terms of the MIT License which is available at */
/* https://opensource.org/licenses/MIT. */
/* */
/* SPDX-License-Identifier: MIT */
/***************************************************************************/
#include "netx_dhcp_clone_function.h"
#include "nxd_dhcp_client.h"
#include "nxd_dhcp_server.h"
UINT dhcp_get_option_value(UCHAR *bootp_message, UINT option, ULONG *value, UINT length)
{
UCHAR *data;
/* Find the option. */
if ((option != NX_DHCP_OPTION_PAD) && (option != NX_DHCP_OPTION_END))
{
/* Search the buffer for the option. */
data = dhcp_search_buffer(bootp_message, option, length);
/* Check to see if the option was found. */
if (data != NX_NULL)
{
/* Check for the proper size. */
if (*data > 4)
{
/* Check for the gateway option. */
if (option == NX_DHCP_OPTION_GATEWAYS)
{
/* Pickup the first gateway address. */
*value = dhcp_get_data(data + 1, 4);
/* For now, just disregard any additional gateway addresses. */
return(NX_SUCCESS);
}
else
{
/* Invalid size, return error. */
return(NX_SIZE_ERROR);
}
}
else
{
/* Get the actual value. */
*value = dhcp_get_data(data + 1, *data);
return(NX_SUCCESS);
}
}
}
/* Return an error if not found. */
return(NX_OPTION_ERROR);
}
UCHAR *dhcp_search_buffer(UCHAR *bootp_message, UINT option, UINT length)
{
UCHAR *data;
UINT i;
/* Setup buffer pointer. */
data = &bootp_message[NX_BOOTP_OFFSET_OPTIONS];
i = NX_BOOTP_OFFSET_OPTIONS;
/* Search as long as there are valid options. */
while (i < length)
{
/* Simply skip any padding */
if (*data == NX_DHCP_OPTION_PAD)
{
data++;
i++;
}
/* On a match, return a pointer to the size. */
else if (*data == option)
{
/* Return a pointer to the option size byte. */
return(data + 1);
}
/* Otherwise skip the option by adding the size to the pointer. */
else
{
UINT size = *(++data);
/* skip the data plus the size byte */
data += size + 1;
i += size + 1;
}
}
/* Return NULL to indicate the option was not found. */
return(NX_NULL);
}
ULONG dhcp_get_data(UCHAR *data, UINT size)
{
ULONG value = 0;
/* Process the data retrieval request. */
while (size-- > 0)
{
/* Build return value. */
value = (value << 8) | *data++;
}
/* Return value. */
return(value);
}
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