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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 37760C433F5 for ; Thu, 28 Apr 2022 11:43:51 +0000 (UTC) Received: from localhost ([::1]:39132 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nk2Yo-0000co-Dn for qemu-devel@archiver.kernel.org; Thu, 28 Apr 2022 07:43:50 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:39348) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nk2ET-0000DX-RL; Thu, 28 Apr 2022 07:22:50 -0400 Received: from kylie.crudebyte.com ([5.189.157.229]:56221) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nk2EP-0000Ps-AR; Thu, 28 Apr 2022 07:22:48 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=crudebyte.com; s=kylie; h=Content-Type:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Content-ID:Content-Description; bh=2tzvCirzIt9kkSHYGsLnwRmWKdhNpnBilO3YKMIzcpY=; b=GFE9pCImoUf4H0QDA8UR7B2Ndr SSL7OgTu07ch+Zq+hUDvPZaei2L3ordCyA/V8UWVqqnUqeikcby2HcBX48zg/VNOhmqCEXyA4Ykrr mUCcfl+lUm1U4LqWtxTheZzlQBKzsptHbW6gvmuVMvBKSnbhCVoDlbBUOcMi4+4uo48yaS9uZ3/oJ SfvxhtDDIv0e7ixClSwkG8w+V4VezeIIZ4U+1M25jyXYmwKy5gBfb0kkg02tn/fFprIGy53ciFnzV lLXyuv9Ispb3DfuEb26DmJIRecaMrM2oDxEfchNOkKqaElxzchMb5eIlB2VGLh92QoSLSzX5GB901 NLMycVJ0EtgSEiJzJq40NaYyoXPhUCqjAY7xrQC6nQcaqBTHrnL19QD1dbu/5cZXfkv4KixB/ojfR VTB9ASMiGH/KvgQ28g/JNgqwgaCYNm2SWU6QV61Ux4NHoes18PVOjJr6RklulVIie5J6joHztX+eI Dg3sy2Qi8wNP4qv4kVvvtM1xQP3BO1Ye5TBUPRmV+toZIMvxaL5aeVBj72rTUJZdSLNxadKWipabX budYenlNAV++5XBqiCQWd4gftlgjMkrxU6o5YN3919Xit0WWZOFGSqGAwSKkul3I19TG9Z1XqL9pe mlLF4qlXja/D/k2LneV2Wy8brBDjSy/DdEapQ7ULY=; From: Christian Schoenebeck To: Greg Kurz Cc: qemu-devel@nongnu.org, qemu-stable@nongnu.org, Keno Fischer , Michael Roitzsch , Will Cohen , Akihiko Odaki Subject: Re: [PATCH v4 2/6] 9pfs: fix qemu_mknodat(S_IFSOCK) on macOS Date: Thu, 28 Apr 2022 13:22:26 +0200 Message-ID: <1976549.2SI88kFQN7@silver> In-Reply-To: <20220427223625.52e0e23f@bahia> References: <489275615f29a2efc97cbd6130c98669ed28a24b.1651085922.git.qemu_oss@crudebyte.com> <20220427223625.52e0e23f@bahia> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Received-SPF: pass client-ip=5.189.157.229; envelope-from=qemu_oss@crudebyte.com; helo=kylie.crudebyte.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Mittwoch, 27. April 2022 22:36:25 CEST Greg Kurz wrote: > On Wed, 27 Apr 2022 20:54:17 +0200 > > Christian Schoenebeck wrote: > > mknod() on macOS does not support creating sockets, so divert to > > call sequence socket(), bind() and fchmodat() respectively if S_IFSOCK > > was passed with mode argument. > > > > Link: https://lore.kernel.org/qemu-devel/17933734.zYzKuhC07K@silver/ > > Signed-off-by: Christian Schoenebeck > > --- > > > > hw/9pfs/9p-util-darwin.c | 45 +++++++++++++++++++++++++++++++++++++++- > > 1 file changed, 44 insertions(+), 1 deletion(-) > > > > diff --git a/hw/9pfs/9p-util-darwin.c b/hw/9pfs/9p-util-darwin.c > > index e24d09763a..7d00db47a9 100644 > > --- a/hw/9pfs/9p-util-darwin.c > > +++ b/hw/9pfs/9p-util-darwin.c > > @@ -74,6 +74,45 @@ int fsetxattrat_nofollow(int dirfd, const char > > *filename, const char *name,> > > */ > > > > #if defined CONFIG_PTHREAD_FCHDIR_NP > > > > +static int create_socket_file_at_cwd(const char *filename, mode_t mode) { > > + int fd, err; > > + struct sockaddr_un addr = { > > + .sun_family = AF_UNIX > > + }; > > + > > + /* > > + * sun_path is only 104 bytes, explicit filename length check > > required > > + */ > > + if (sizeof(addr.sun_path) - 1 < strlen(filename) + 2) { > > True but I was a bit puzzled by the math until I realized the '+ 2' was > for the prepended "./" ;-) Correct ... > > + errno = ENAMETOOLONG; > > + return -1; > > + } > > + fd = socket(PF_UNIX, SOCK_DGRAM, 0); > > + if (fd == -1) { > > + return fd; > > + } > > + snprintf(addr.sun_path, sizeof(addr.sun_path), "./%s", filename); > > What about the more generic approach of checking snprintf()'s return > value ? If it is >= sizeof(addr.sun_path) then truncation occured. ... well, I can send a v5 if you prefer that solution, or you can send a follow-up patch later on. As you wish. > > + err = bind(fd, (struct sockaddr *) &addr, sizeof(addr)); > > + if (err == -1) { > > + goto out; > > + } > > + /* > > + * FIXME: Should rather be using descriptor-based fchmod() on the > > + * socket file descriptor above (preferably before bind() call), > > + * instead of path-based fchmodat(), to prevent concurrent transient > > + * state issues between creating the named FIFO file at bind() and > > + * delayed adjustment of permissions at fchmodat(). However currently > > + * macOS (12.x) does not support such operations on socket file > > + * descriptors yet. > > + * > > + * Filed report with Apple: FB9997731 > > + */ > > + err = fchmodat(AT_FDCWD, filename, mode, AT_SYMLINK_NOFOLLOW_ANY); > > +out: > > + close_preserve_errno(fd); > > You could close(fd) earlier now, but you might want to keep the code > as is in case FB9997731 gets proper attention. > > Anyway, this should do the job so: Sounds like Akihiko's previous suggestion. I would keep it that way: https://lore.kernel.org/qemu-devel/eafd4bbf-dbff-323a-179f-8f29905701e1@gmail.com/ > Reviewed-by: Greg Kurz Thanks! Best regards, Christian Schoenebeck > > + return err; > > +} > > + > > > > int qemu_mknodat(int dirfd, const char *filename, mode_t mode, dev_t dev) > > { > > > > int preserved_errno, err; > > > > @@ -93,7 +132,11 @@ int qemu_mknodat(int dirfd, const char *filename, > > mode_t mode, dev_t dev)> > > if (pthread_fchdir_np(dirfd) < 0) { > > > > return -1; > > > > } > > > > - err = mknod(filename, mode, dev); > > + if (S_ISSOCK(mode)) { > > + err = create_socket_file_at_cwd(filename, mode); > > + } else { > > + err = mknod(filename, mode, dev); > > + } > > > > preserved_errno = errno; > > /* Stop using the thread-local cwd */ > > pthread_fchdir_np(-1);