From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Yurij M. Plotnikov" Subject: TCP socket receives strange packet Date: Tue, 14 Oct 2014 18:09:54 +0400 Message-ID: <543D2EB2.4000009@oktetlabs.ru> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="------------020208070708090309040403" Cc: "Alexandra N. Kossovsky" To: netdev@vger.kernel.org Return-path: Received: from shelob.oktetlabs.ru ([84.52.89.53]:52147 "EHLO shelob.oktetlabs.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755282AbaJNOTE (ORCPT ); Tue, 14 Oct 2014 10:19:04 -0400 Sender: netdev-owner@vger.kernel.org List-ID: This is a multi-part message in MIME format. --------------020208070708090309040403 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Connected TCP socket receives packet without timestamps option which exists in SYN, SYNACK and ACK. It is packet 4 in attached tcpdump output. tcpdump output description: The host has address 10.208.10.1 (server) and the peer host has address 10.208.10.2 (client). Establishing connection: Timestamps option exists in SYN, SYNACK and ACK (packets 1, 2 and 3 in attached file), so accepted socket should receive packets only with timestamps option. Sending packet: the socket receives the packet without timestamps option (packet 4 in attached file), i.e. recv() function called on the socket receives the data from the packet. The "strange" packet is generated using PCAP. I see this behaviour on 2.6.26 and on 3.14 kernels. --------------020208070708090309040403 Content-Type: application/octet-stream; name="pcap_with_bad_packet" Content-Transfer-Encoding: base64 Content-Disposition: attachment; filename="pcap_with_bad_packet" 1MOyoQIABAAAAAAAAAAAANwFAAABAAAAKaIzVLqlDgBKAAAASgAAAAAPUwE5fAAPUwE5lAgA RQAAPHbYQABABppBCtAKAgrQCgFlvWW8lT487wAAAACgAnIQxF4AAAIEBbQEAggKABBKNwAA AAABAwMHKaIzVNmlDgBKAAAASgAAAAAPUwE5lAAPUwE5fAgARQAAPAAAQABABhEaCtAKAQrQ CgJlvGW9JBhNSpU+PPCgEnEgKdEAAAIEBbQEAggKABB/SgAQSjcBAwMHKaIzVDamDgBCAAAA QgAAAAAPUwE5fAAPUwE5lAgARQAANHbZQABABppICtAKAgrQCgFlvWW8lT488CQYTUuAEADl c4gAAAEBCAoAEEo3ABB/SiqiM1R/GgIAPAAAADwAAAAAD1MBOXwAD1MBOZQIAEUAACkAAAAA QAZRLQrQCgIK0AoBZb1lvJU+PPAkGE1KUBj//xAeAABnAAAAAAAqojNUnBoCAEIAAABCAAAA AA9TATmUAA9TATl8CABFAAA0MgFAAEAG3yAK0AoBCtAKAmW8Zb0kGE1LlT488YAQAOMpyQAA AQEICgAQf3cAEEo3KqIzVKKQAwBCAAAAQgAAAAAPUwE5lAAPUwE5fAgARQAANDICQABABt8f CtAKAQrQCgJlvGW9JBhNS5U+PPGAEQDjKckAAAEBCAoAEH+OABBKNyqiM1S+kwMAQgAAAEIA AAAAD1MBOXwAD1MBOZQIAEUAADR22kAAQAaaRwrQCgIK0AoBZb1lvJU+PPAkGE1LgBEA5XNC AAABAQgKABBKfAAQf0oqojNU3ZMDAE4AAABOAAAAAA9TATmUAA9TATl8CABFAABAMgNAAEAG 3xIK0AoBCtAKAmW8Zb0kGE1MlT488bAQAOMp1QAAAQEICgAQf48AEEp8AQEFCpU+PPCVPjzx KqIzVJG7CQBCAAAAQgAAAAAPUwE5lAAPUwE5fAgARQAANDIEQABABt8dCtAKAQrQCgJlvGW9 JBhNS5U+PPGAEQDjKckAAAEBCAoAEH/0ABBKfCqiM1T2uwkAQgAAAEIAAAAAD1MBOXwAD1MB OZQIAEUAADRHFUAAQAbKDArQCgIK0AoBZb1lvJU+PPEkGE1MgBAA5XIyAAABAQgKABBK4QAQ f/Q= --------------020208070708090309040403--