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=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 58B20C433ED for ; Tue, 11 May 2021 19:29:52 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 8CBA16162A for ; Tue, 11 May 2021 19:29:51 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8CBA16162A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:38538 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lgY4k-0001p4-Em for qemu-devel@archiver.kernel.org; Tue, 11 May 2021 15:29:50 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:54418) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lgY3H-0007y3-4A for qemu-devel@nongnu.org; Tue, 11 May 2021 15:28:19 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:31714) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lgY3F-0000hg-9X for qemu-devel@nongnu.org; Tue, 11 May 2021 15:28:18 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1620761296; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=NTD0kmZoerFXgqG0MHWGgVEGzIhqMHypAWGpGBgDxv4=; b=aikbEhxEXEAFxC2g0Wm3Cd2v1uvOV33E5IzM/fCIAVlUaeqdrV/VeC4R3NkzV311FVwhGj Owcau3PIzKae+zG4/f/BUgZj97uCg+b+uglA6mrN52aS4wL+2voS0EMetzgdDOyTlcyhL5 MZzMhdAFQYheB0gxH9Q5TPDyUWRLvDA= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-507-8EjBPGNMMDGnjdmozPbLCg-1; Tue, 11 May 2021 15:28:12 -0400 X-MC-Unique: 8EjBPGNMMDGnjdmozPbLCg-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id D3FAB81870C; Tue, 11 May 2021 19:28:11 +0000 (UTC) Received: from blue.redhat.com (ovpn-114-221.phx2.redhat.com [10.3.114.221]) by smtp.corp.redhat.com (Postfix) with ESMTP id 9559F5D9D7; Tue, 11 May 2021 19:28:04 +0000 (UTC) From: Eric Blake To: qemu-devel@nongnu.org Subject: [PULL 1/1] sockets: update SOCKET_ADDRESS_TYPE_FD listen(2) backlog Date: Tue, 11 May 2021 14:28:02 -0500 Message-Id: <20210511192802.552706-2-eblake@redhat.com> In-Reply-To: <20210511192802.552706-1-eblake@redhat.com> References: <20210511192802.552706-1-eblake@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=eblake@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset="US-ASCII" Received-SPF: pass client-ip=216.205.24.124; envelope-from=eblake@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -34 X-Spam_score: -3.5 X-Spam_bar: --- X-Spam_report: (-3.5 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.699, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= , Juan Quintela , qemu-stable@nongnu.org, "Richard W . M . Jones" , Gerd Hoffmann , Stefan Hajnoczi , Stefano Garzarella Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" From: Stefan Hajnoczi socket_get_fd() fails with the error "socket_get_fd: too many connections" if the given listen backlog value is not 1. Not all callers set the backlog to 1. For example, commit 582d4210eb2f2ab5baac328fe4b479cd86da1647 ("qemu-nbd: Use SOMAXCONN for socket listen() backlog") uses SOMAXCONN. This will always fail with in socket_get_fd(). This patch calls listen(2) on the fd to update the backlog value. The socket may already be in the listen state. I have tested that this works on Linux 5.10 and macOS Catalina. As a bonus this allows us to detect when the fd cannot listen. Now we'll be able to catch unbound or connected fds in socket_listen(). Drop the num argument from socket_get_fd() since this function is also called by socket_connect() where a listen backlog value does not make sense. Fixes: e5b6353cf25c99c3f08bf51e29933352f7140e8f ("socket: Add backlog parameter to socket_listen") Reported-by: Richard W.M. Jones Cc: Juan Quintela Cc: Eric Blake Signed-off-by: Stefan Hajnoczi Message-Id: <20210310173004.420190-1-stefanha@redhat.com> Tested-by: Richard W.M. Jones Reviewed-by: Eric Blake Reviewed-by: Stefano Garzarella Signed-off-by: Eric Blake --- util/qemu-sockets.c | 29 ++++++++++++++++++++++------- 1 file changed, 22 insertions(+), 7 deletions(-) diff --git a/util/qemu-sockets.c b/util/qemu-sockets.c index 8af0278f15c6..2463c49773ea 100644 --- a/util/qemu-sockets.c +++ b/util/qemu-sockets.c @@ -1116,14 +1116,10 @@ fail: return NULL; } -static int socket_get_fd(const char *fdstr, int num, Error **errp) +static int socket_get_fd(const char *fdstr, Error **errp) { Monitor *cur_mon = monitor_cur(); int fd; - if (num != 1) { - error_setg_errno(errp, EINVAL, "socket_get_fd: too many connections"); - return -1; - } if (cur_mon) { fd = monitor_get_fd(cur_mon, fdstr, errp); if (fd < 0) { @@ -1159,7 +1155,7 @@ int socket_connect(SocketAddress *addr, Error **errp) break; case SOCKET_ADDRESS_TYPE_FD: - fd = socket_get_fd(addr->u.fd.str, 1, errp); + fd = socket_get_fd(addr->u.fd.str, errp); break; case SOCKET_ADDRESS_TYPE_VSOCK: @@ -1187,7 +1183,26 @@ int socket_listen(SocketAddress *addr, int num, Error **errp) break; case SOCKET_ADDRESS_TYPE_FD: - fd = socket_get_fd(addr->u.fd.str, num, errp); + fd = socket_get_fd(addr->u.fd.str, errp); + if (fd < 0) { + return -1; + } + + /* + * If the socket is not yet in the listen state, then transition it to + * the listen state now. + * + * If it's already listening then this updates the backlog value as + * requested. + * + * If this socket cannot listen because it's already in another state + * (e.g. unbound or connected) then we'll catch the error here. + */ + if (listen(fd, num) != 0) { + error_setg_errno(errp, errno, "Failed to listen on fd socket"); + closesocket(fd); + return -1; + } break; case SOCKET_ADDRESS_TYPE_VSOCK: -- 2.31.1