From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 85D04C433DB for ; Wed, 10 Mar 2021 18:17:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4DDE364FB3 for ; Wed, 10 Mar 2021 18:17:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233428AbhCJSRC (ORCPT ); Wed, 10 Mar 2021 13:17:02 -0500 Received: from mout.kundenserver.de ([212.227.17.10]:49177 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232802AbhCJSQj (ORCPT ); Wed, 10 Mar 2021 13:16:39 -0500 Received: from maxwell ([93.223.218.186]) by mrelayeu.kundenserver.de (mreue109 [213.165.67.113]) with ESMTPSA (Nemesis) id 1MxUfn-1ldnAI1zzd-00xpS4 for ; Wed, 10 Mar 2021 19:16:35 +0100 User-agent: mu4e 1.2.0; emacs 27.1 From: Henneberg - Systemdesign To: netdev@vger.kernel.org Subject: TIOCOUTQ implementation for sockets vs. tty Date: Wed, 10 Mar 2021 19:16:34 +0100 Message-ID: <87ft12ri0t.fsf@henneberg-systemdesign.com> MIME-Version: 1.0 Content-Type: text/plain X-Provags-ID: V03:K1:8S+rHgaJgqUsw0/68YKQ4JAGo9ARiBCDABgPUMGWgr6tgGRZrz0 uNPew7/lOVSWgWSnJDq7iOACl7i35jLXdnqnzME2kTzDR9GGFhM/wrr3ZCUg7Hh/OXC2Ir7 4bOEFJRQyN6hZmiaRH+ND9qxhIzUf3mVDYQs+laRGuUOKWcQ3F0JJKk75MaiTIXk1aoCkzU PXwntmCS5316mgd80RQXg== X-UI-Out-Filterresults: notjunk:1;V03:K0:LV9bpZL2T4s=:G5rByNR/Z/tvY+supL0wXZ 4d4uFBFFHYfw9AWwZuDJiD9p/7aZnwSsoPTugMsUi6tp5z9IM8eohTPz5jgvdVGwwsnGsIw6s i0sBfs6F5cZJuTE6SkTAJePXzoLGL5HCJkiESgYQ//ULrOSjIrjy31ogAb1xMeYTo9+r0XN8l Zeb6uhsMZI+Wn7LS6Rp784/vW+8XGVlx7nnG9OKSq577Z9MKWUhyMrsqj9RnBOWzf9hM4pTfe unKNMopE7GyPgVomM9lfBt8SF10kFE3gPGN/4luNOgOeDAbhh36/LNnkeRysV++eexmVbRqwv NAi7eom7gcC4VWJ9LXu4+p/Cgasawz1vMVjM4vXWPXQAnQxp1PErMiklF6gTuBDbO/mUBO47O 05RTRmmUntfCYPFU8LY/PFIoSVnFcBb1yLHZ5LQnQl6Uv3Bg5roYHQ2tMnF7S1agiav5gMfnc frEvsYDD0w== Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Hi, I have a question regarding the implementation of ioctl TIOCOUTQ for various sockets compared to the tty implementation. For several sockets, e. g. AF_BLUETOOTH it is done like this af_bluetooth.c: case TIOCOUTQ: if (sk->sk_state == BT_LISTEN) return -EINVAL; amount = sk->sk_sndbuf - sk_wmem_alloc_get(sk); if (amount < 0) amount = 0; err = put_user(amount, (int __user *)arg); break; so the ioctl returns the available space in the send queue if I understand the code correctly (this is also what I observed from tests). The tty does this: n_tty.c: case TIOCOUTQ: return put_user(tty_chars_in_buffer(tty), (int __user *) arg); so it returns the used space in the send queue. This is also what I would expect from the manpage description. Is this mismatch intentional? Regards -Jochen