Is protocol type limited to 8 bit in socket creation?

[zekelandon]

Hi There,

I am Zeke, working on sample projects to understand the capability of NXP MIMXRT1064 board and FreeRTOS. In this process, I was creating a raw socket with custom protocol say 0xFFFF (more than 8 bits). In case of raw socket, netconn_new_with_proto_and_callback() method typecasts the protocol to uint8_t hence I am losing 8 bits in my protocol type thus resulting in different one than I intended.

Protocol intended: 0xFFFF

Protocol created:  0xFF (lost 8 bits in typecasting)

Is this a limitation? Or there exists a way to handle protocol type of more than 8 bits in raw socket?

Regards,

Zeke

[kerryzhou]

Hi zekelandon ，

 From the netconn code structure, this is fixed to 8 bit.

So, you need to use 8 bit mode.

Wish it helps you!

Kerry

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[zekelandon]

Hi Kerry,

In that case, it is limitation of the system right?

Regards,

Zeke

[kerryzhou]

Hi zekelandon,

  Today, I help you to check with our expert.

   He told me that the 8 bit proto is determined by the LWIP, the LWIP stack just can support the 8 bit proto. Your 16 bit may from the full function of the TCP/IP protocal.

   We suggest you use the 8bit instead of the 16 bit.

Wish it helps you!

Kerry

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