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=-16.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 8B58EC433DB for ; Mon, 25 Jan 2021 23:38:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 55A9222AAA for ; Mon, 25 Jan 2021 23:38:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732879AbhAYXiD (ORCPT ); Mon, 25 Jan 2021 18:38:03 -0500 Received: from mail.kernel.org ([198.145.29.99]:37606 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732663AbhAYXhc (ORCPT ); Mon, 25 Jan 2021 18:37:32 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 0B25A2226A; Mon, 25 Jan 2021 23:36:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1611617811; bh=btQutt9g5gmPo92SiwndArw245bwhH2tfk1kHeGLqwA=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=VhQoLJXnNotLp3TZxEwUaKno4R5egQqxuQj+wh74UvfI4Zrfk8cqifEJiqsVtl7e6 1wWOIsOTGBMgopWtGz4r/Ga7aUieMivVs2FnYdgEcEjQxscgUVDBdvNvNO/a9qkoc2 27wWtYe/7ZCZCysNAmnGu7NWcvh3VXR2+UbwN2bhdCp9Pekr4PlS1IL6i4OHak6GEx JEs7/tlN2sBB5JuBWqw60OBYMrXd4n23AdqdKKAiTFKo7wJOaUTOkmSX/tFsuYvQco wE66K+C/Lv+ZWypcsUX4l1E691Dedcw/eo2HL6iMWaMGoY4lbhfGppNXIn4mPjsTGv kQUdcgvlbFW3g== Date: Mon, 25 Jan 2021 15:36:50 -0800 From: Jakub Kicinski To: "Matthew Wilcox (Oracle)" Cc: linux-kernel@vger.kernel.org, linux-api@vger.kernel.org, netdev@vger.kernel.org, "David S. Miller" , andy.rudoff@intel.com, Rao Shoaib Subject: Re: [PATCH] af_unix: Allow Unix sockets to raise SIGURG Message-ID: <20210125153650.18c84b1a@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> In-Reply-To: <20210122150638.210444-1-willy@infradead.org> References: <20210122150638.210444-1-willy@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 22 Jan 2021 15:06:37 +0000 Matthew Wilcox (Oracle) wrote: > From: Rao Shoaib > > TCP sockets allow SIGURG to be sent to the process holding the other > end of the socket. Extend Unix sockets to have the same ability. > > The API is the same in that the sender uses sendmsg() with MSG_OOB to > raise SIGURG. Unix sockets behave in the same way as TCP sockets with > SO_OOBINLINE set. Noob question, if we only want to support the inline mode, why don't we require SO_OOBINLINE to have been called on @other? Wouldn't that provide more consistent behavior across address families? With the current implementation the receiver will also not see MSG_OOB set in msg->msg_flags, right? > SIGURG is ignored by default, so applications which do not know about this > feature will be unaffected. In addition to installing a SIGURG handler, > the receiving application must call F_SETOWN or F_SETOWN_EX to indicate > which process or thread should receive the signal. > > Signed-off-by: Rao Shoaib > Signed-off-by: Matthew Wilcox (Oracle) > --- > net/unix/af_unix.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c > index 41c3303c3357..849dff688c2c 100644 > --- a/net/unix/af_unix.c > +++ b/net/unix/af_unix.c > @@ -1837,8 +1837,6 @@ static int unix_stream_sendmsg(struct socket *sock, struct msghdr *msg, > return err; > > err = -EOPNOTSUPP; > - if (msg->msg_flags&MSG_OOB) > - goto out_err; > > if (msg->msg_namelen) { > err = sk->sk_state == TCP_ESTABLISHED ? -EISCONN : -EOPNOTSUPP; > @@ -1903,6 +1901,9 @@ static int unix_stream_sendmsg(struct socket *sock, struct msghdr *msg, > sent += size; > } > > + if (msg->msg_flags & MSG_OOB) > + sk_send_sigurg(other); > + > scm_destroy(&scm); > > return sent;