From patchwork Fri Sep 17 05:40:37 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Snow X-Patchwork-Id: 12501075 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=-13.5 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,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 3F3E4C433F5 for ; Fri, 17 Sep 2021 05:50:27 +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 BF71A61164 for ; Fri, 17 Sep 2021 05:50:26 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org BF71A61164 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=nongnu.org Received: from localhost ([::1]:51852 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mR6lV-00029e-Ud for qemu-devel@archiver.kernel.org; Fri, 17 Sep 2021 01:50:25 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:48118) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mR6cd-0004xZ-W5 for qemu-devel@nongnu.org; Fri, 17 Sep 2021 01:41:18 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:56836) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mR6cc-0003Pa-6O for qemu-devel@nongnu.org; Fri, 17 Sep 2021 01:41:15 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1631857273; 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=ot8HoQOgqwT7KWP3fKFHnIUaea26CVj45BSZLAmhnCs=; b=ioO/ZoJv+UP3+VvtapbMiA1WMBjZKwOe+Oz5OJND1LqNGBffVyUcUqyVuNizqbkJvlfvdx 1y5Kn8xSQGKWj/v9/RPQhgXJ41d0La1V1hNtQO8XtbUZtUe4xs/FieoJriTwL5paw+N42a TpoiygZPZm2SURyfoaAMqmbfdf1CyCY= 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-258-LbgdBv3jOPKmfBZoIXIGtw-1; Fri, 17 Sep 2021 01:41:10 -0400 X-MC-Unique: LbgdBv3jOPKmfBZoIXIGtw-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 74E8F824FAB; Fri, 17 Sep 2021 05:41:09 +0000 (UTC) Received: from scv.redhat.com (unknown [10.22.11.132]) by smtp.corp.redhat.com (Postfix) with ESMTP id A102E60843; Fri, 17 Sep 2021 05:41:07 +0000 (UTC) From: John Snow To: qemu-devel@nongnu.org Subject: [PATCH 05/15] python/qmp: add send_fd_scm directly to QEMUMonitorProtocol Date: Fri, 17 Sep 2021 01:40:37 -0400 Message-Id: <20210917054047.2042843-6-jsnow@redhat.com> In-Reply-To: <20210917054047.2042843-1-jsnow@redhat.com> References: <20210917054047.2042843-1-jsnow@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=jsnow@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=170.10.133.124; envelope-from=jsnow@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -31 X-Spam_score: -3.2 X-Spam_bar: --- X-Spam_report: (-3.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.392, 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_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham 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: Kevin Wolf , Vladimir Sementsov-Ogievskiy , Eduardo Habkost , qemu-block@nongnu.org, Hanna Reitz , Cleber Rosa , John Snow Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" It turns out you can do this directly from Python ... and because of this, you don't need to worry about setting the inheritability of the fds or spawning another process. Doing this is helpful because it allows QEMUMonitorProtocol to keep its file descriptor and socket object as private implementation details. *that* is helpful in turn because it allows me to write a compatible, alternative implementation. Signed-off-by: John Snow Reviewed-by: Hanna Reitz --- python/qemu/machine/machine.py | 44 +++++++--------------------------- python/qemu/qmp/__init__.py | 21 +++++++--------- 2 files changed, 18 insertions(+), 47 deletions(-) diff --git a/python/qemu/machine/machine.py b/python/qemu/machine/machine.py index ae945ca3c9..1c6532a3d6 100644 --- a/python/qemu/machine/machine.py +++ b/python/qemu/machine/machine.py @@ -213,48 +213,22 @@ def add_fd(self: _T, fd: int, fdset: int, def send_fd_scm(self, fd: Optional[int] = None, file_path: Optional[str] = None) -> int: """ - Send an fd or file_path to socket_scm_helper. + Send an fd or file_path to the remote via SCM_RIGHTS. - Exactly one of fd and file_path must be given. - If it is file_path, the helper will open that file and pass its own fd. + Exactly one of fd and file_path must be given. If it is + file_path, the file will be opened read-only and the new file + descriptor will be sent to the remote. """ - # In iotest.py, the qmp should always use unix socket. - assert self._qmp.is_scm_available() - if self._socket_scm_helper is None: - raise QEMUMachineError("No path to socket_scm_helper set") - if not os.path.exists(self._socket_scm_helper): - raise QEMUMachineError("%s does not exist" % - self._socket_scm_helper) - - # This did not exist before 3.4, but since then it is - # mandatory for our purpose - if hasattr(os, 'set_inheritable'): - os.set_inheritable(self._qmp.get_sock_fd(), True) - if fd is not None: - os.set_inheritable(fd, True) - - fd_param = ["%s" % self._socket_scm_helper, - "%d" % self._qmp.get_sock_fd()] - if file_path is not None: assert fd is None - fd_param.append(file_path) + with open(file_path, "rb") as passfile: + fd = passfile.fileno() + self._qmp.send_fd_scm(fd) else: assert fd is not None - fd_param.append(str(fd)) + self._qmp.send_fd_scm(fd) - proc = subprocess.run( - fd_param, - stdin=subprocess.DEVNULL, - stdout=subprocess.PIPE, - stderr=subprocess.STDOUT, - check=False, - close_fds=False, - ) - if proc.stdout: - LOG.debug(proc.stdout) - - return proc.returncode + return 0 @staticmethod def _remove_if_exists(path: str) -> None: diff --git a/python/qemu/qmp/__init__.py b/python/qemu/qmp/__init__.py index ba15668c25..c3b8a70ec9 100644 --- a/python/qemu/qmp/__init__.py +++ b/python/qemu/qmp/__init__.py @@ -21,6 +21,7 @@ import json import logging import socket +import struct from types import TracebackType from typing import ( Any, @@ -408,18 +409,14 @@ def settimeout(self, timeout: Optional[float]) -> None: raise ValueError(msg) self.__sock.settimeout(timeout) - def get_sock_fd(self) -> int: + def send_fd_scm(self, fd: int) -> None: """ - Get the socket file descriptor. - - @return The file descriptor number. - """ - return self.__sock.fileno() - - def is_scm_available(self) -> bool: + Send a file descriptor to the remote via SCM_RIGHTS. """ - Check if the socket allows for SCM_RIGHTS. + if self.__sock.family != socket.AF_UNIX: + raise RuntimeError("Can't use SCM_RIGHTS on non-AF_UNIX socket.") - @return True if SCM_RIGHTS is available, otherwise False. - """ - return self.__sock.family == socket.AF_UNIX + self.__sock.sendmsg( + [b' '], + [(socket.SOL_SOCKET, socket.SCM_RIGHTS, struct.pack('@i', fd))] + )