netdev - ETH_P_ALL and tcp ports

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Message-ID: <CAJX4=r3JivtYLFG=Eh0qiTmyufCF414-h4siJCHoL3wAaRVLKg@mail.gmail.com>
Date:	Sun, 2 Jun 2013 12:42:40 -0300
From:	Felipe Dias <felipediassss@...il.com>
To:	netdev@...r.kernel.org
Subject: ETH_P_ALL and tcp ports

Hi, someone might try to tell me what I'm doing wrong, please?

I have a simple module and I registered one packet handler, in init function:
---
     pseudo_proto.type = htons(ETH_P_ALL);
     pseudo_proto.dev = NULL;
     pseudo_proto.func = packet_handler;
     dev_add_pack(&pseudo_proto);
---

My packet_handler, is a simple function just to print in dmesg info
about the packet, its check if protocol is TCP or UDP before.

The problem is with TCP headers. I'm trying to get tcp ports with:

ntohs(tcp_hdr(skb)->dest);

But always come strange ports numbers.

My question is: Are the TCP headers filled at this stage ?
Or I have to register another packet_handler with dev_add_pack() after
TCP code have done the heavy work?

Best regards,
Felipe
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