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##

# TCPIP_IPV4_PacketOptionGet Function

## C

    int TCPIP_IPV4_PacketOptionGet(
        TCPIP_MAC_PACKET* pRxPkt,
        TCPIP_IPV4_OPTION_TYPE optType,
        IPV4_OPTION_FIELD* pOptField,
        int optSize
    );

## Description

This function is a helper to allow retrieving a specific option that is present in an IPv4 received packet.

## Preconditions

IPv4 properly initialized. pRxPkt a proper IPv4 packet received by the IPv4 module.

## Parameters

Parameters | Description
--- | ---
pRxPkt | A packet received by the IPv4 module.
optType | Type of options to be searched/retrieved.
pOptField | Address to store the option. Could be NULL if not needed.
optSize | Size of the pOptField structure, including the optData part. If 0, pOptField will not be updated.

## Returns

- Size of the option, if found in the IPv4 packet.
- 0 if such an option does not exist.

## Remarks

The packet should be a proper IPv4 packet received through the IPv4 module. Only minimal consistency check is done.