From owner-freebsd-net@freebsd.org Thu Mar 8 02:39:29 2018 Return-Path: Delivered-To: freebsd-net@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 78F79F4BD34 for ; Thu, 8 Mar 2018 02:39:29 +0000 (UTC) (envelope-from cameledyang@gmail.com) Received: from mail-lf0-x22f.google.com (mail-lf0-x22f.google.com [IPv6:2a00:1450:4010:c07::22f]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id CC2647E792 for ; Thu, 8 Mar 2018 02:39:28 +0000 (UTC) (envelope-from cameledyang@gmail.com) Received: by mail-lf0-x22f.google.com with SMTP id y19-v6so6224850lfd.4 for ; Wed, 07 Mar 2018 18:39:28 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:from:date:message-id:subject:to; bh=jwWcsOf63fpkZ2PpYcoYXcclxakhmpPaSXjuCmQWNXU=; b=dfRXufFZkp0XNyd24br34cS/RwIMDNdiRocexhhs7E7KDqhjL9KSq9KRsQOfcg5gIr U9iRlPZP+OT+3wOmPgSejSqQMtGTNdEAuTga3UrkIFyvc95sVPgGHq9CbUzA1HWy7fTF ExTQc3no4IXGOfyUe+TA3d3j7k0Nz/tNncPQ7XxjqxG2LD2iML3uzCJ/NF+/hA6s5bcz frfjHm2qYzX5U0ewde39GWlf8Wq8h8aH7e3FtL/OkC5XI1bO6nPzbx81nNPE1q/TRYaz fgYwZQ7nLa5w+EmmLw0X9d0gVSGiEpWQqpdDgdP6u3J6mnnWa20c7kdm1wKDWvGu/A9k eBAA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:from:date:message-id:subject:to; bh=jwWcsOf63fpkZ2PpYcoYXcclxakhmpPaSXjuCmQWNXU=; b=kmQ10uXc9qYjQkNuHe3qZIQ8o7yi96nsul3TPpluen8JNusnzVwzohVrT6hjeWVyS1 y5+2atEjPfL+gE5OBH8qyiUMTGJHIBtFVs7hpdxyEr7O7kpltjDwOhWhEDFCD96h37TO 1ou4eDwSWPMcufsJPXPT3c+lZGITbSVcgqqQN3hp/Ol37wiWUcLUYSLKbo8iKKpQkoh2 5wgpJRXs8TXuHhSqKbHDJKuUDBL+7dfNE2/syzI0rlAdb8kqq8PRs/2suF2+Z4L6xGno 81P1ypRLwTDfcEpY8EXDqUhKUysx58tZWQ/LcZbQt2/tnG9zpgcu2dRXbzUI+GtTOAOP zbwQ== X-Gm-Message-State: APf1xPDV7EsjG00ioVnR47QYRxmN39aBizlz2uB3+24gw6iYlJAOwWOU LZ7LF/z5aRNKveIxZJgbAV4xUOjYAoBkyvfCWLyltXTW X-Google-Smtp-Source: AG47ELuo7fNt43wT9i3LoTUGhgH2IrZKYefBD6Ra2Rqj1eUikcIK47O3CIHLE8OLhU4fK1TGAwhCGidTv0JL1N+1jzo= X-Received: by 10.46.114.26 with SMTP id n26mr18030317ljc.74.1520476766996; Wed, 07 Mar 2018 18:39:26 -0800 (PST) MIME-Version: 1.0 Received: by 10.25.208.145 with HTTP; Wed, 7 Mar 2018 18:39:26 -0800 (PST) From: cameled yang Date: Thu, 8 Mar 2018 10:39:26 +0800 Message-ID: Subject: TCP Retransmission meet some problem. To: freebsd-net@freebsd.org Content-Type: text/plain; charset="UTF-8" X-Content-Filtered-By: Mailman/MimeDel 2.1.25 X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.25 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 08 Mar 2018 02:39:29 -0000 Hello, everyone. Recently, I work with a eCos project, It's network stack using freebsd version(Not sure Exactly version, SDK is provide by others). Everything work fine before I meet a problem. When local http server return packet to borwser, sometimes retransmission happened. But rarely in resent tcp payload contain previous sented packet header! (all things are same). cases like this: ... Browser: Sequence number:444, Acknowledgment number: 4600 NetStack: Sequence number:4600, Acknowledgment number: 444 NetStack: Sequence number:7819, Acknowledgment number:444 (Previous segment lost?) Browser: Sequence number:444, Acknowledgment number: 6060 NetStack: Sequence number:6060, Acknowledgment number: 444 (Retansmission happened) ... Sequence 6060 contain 7819's header(Socket cache have been changed). I guess mbuf header of 7819's write it's protocol header info to 6060's cluster. Anyone know something about this? Best Regrads.