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 375AFC05027 for ; Thu, 9 Feb 2023 14:07:26 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pQ7ZT-00073K-GK; Thu, 09 Feb 2023 09:06:43 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pQ7ZR-00072z-JE for qemu-devel@nongnu.org; Thu, 09 Feb 2023 09:06:41 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pQ7ZP-0007rC-Be for qemu-devel@nongnu.org; Thu, 09 Feb 2023 09:06:41 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1675951598; h=from:from:reply-to: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=PI41cjApvkQyOOse8Y3Wf5wohdJ1UWChsiUePvRDBi4=; b=V7NxSOQpsHdIUhM/F2k+nYtZQta+oCnHFQ4Hq1GEZURgTNFxfZVVk0EFtESh/Od/wg9mWJ 6Zler81PsqdYLI71iAkBOzFzoxY5OWmYQJCOhlgRLvT12zWtrbUHQH/mfhMiCw0Nj5Udsf xXVzNUw6O50VzXjYeyCeSpOXFX2uUao= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-503-kHHKX2JmOoGtWHGuJXTSgw-1; Thu, 09 Feb 2023 09:06:35 -0500 X-MC-Unique: kHHKX2JmOoGtWHGuJXTSgw-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 368071875042; Thu, 9 Feb 2023 14:06:33 +0000 (UTC) Received: from redhat.com (unknown [10.33.36.65]) by smtp.corp.redhat.com (Postfix) with ESMTPS id E7CB52026D68; Thu, 9 Feb 2023 14:06:30 +0000 (UTC) Date: Thu, 9 Feb 2023 14:06:28 +0000 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Het Gala Cc: qemu-devel@nongnu.org, prerna.saxena@nutanix.com, quintela@redhat.com, dgilbert@redhat.com, pbonzini@redhat.com, armbru@redhat.com, eblake@redhat.com, manish.mishra@nutanix.com, aravind.retnakaran@nutanix.com Subject: Re: [PATCH v2 4/6] migration: Avoid multiple parsing of uri in migration code flow Message-ID: References: <20230208093600.242665-1-het.gala@nutanix.com> <20230208093600.242665-5-het.gala@nutanix.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/2.2.9 (2022-11-12) X-Scanned-By: MIMEDefang 3.1 on 10.11.54.4 Received-SPF: pass client-ip=170.10.129.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.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, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, 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: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Thu, Feb 09, 2023 at 07:24:48PM +0530, Het Gala wrote: > > On 09/02/23 5:39 pm, Daniel P. Berrangé wrote: > > On Wed, Feb 08, 2023 at 09:35:58AM +0000, Het Gala wrote: > > > In existing senario, 'migrate' QAPI argument - string uri, is encoded > > > twice to extract migration parameters for stream connection. This is > > > not a good representation of migration wire protocol as it is a data > > > encoding scheme within a data encoding scheme. Qemu should be able to > > > directly work with results from QAPI without having to do a second > > > level parsing. > > > Modified 'migrate' QAPI design supports well defined MigrateChannel > > > struct which plays important role in avoiding double encoding > > > of uri strings. > > > > > > qemu_uri_parsing() parses uri string (kept for backward > > > compatibility) and populate the MigrateChannel struct parameters. > > > Migration code flow for all required migration transport types - > > > socket, exec and rdma is modified. > > > > > > Suggested-by: Daniel P. Berrange > > > Suggested-by: Manish Mishra > > > Suggested-by: Aravind Retnakaran > > > Signed-off-by: Het Gala > > > --- > > > migration/exec.c | 31 ++++++++++++++++-- > > > migration/exec.h | 4 ++- > > > migration/migration.c | 75 +++++++++++++++++++++++++++++++++++-------- > > > migration/rdma.c | 30 +++++------------ > > > migration/rdma.h | 3 +- > > > migration/socket.c | 21 ++++-------- > > > migration/socket.h | 3 +- > > > 7 files changed, 110 insertions(+), 57 deletions(-) > > > > > > diff --git a/migration/exec.c b/migration/exec.c > > > index 375d2e1b54..4fa9819792 100644 > > > --- a/migration/exec.c > > > +++ b/migration/exec.c > > > @@ -23,14 +23,39 @@ > > > #include "migration.h" > > > #include "io/channel-command.h" > > > #include "trace.h" > > > +#include "qapi/error.h" > > > -void exec_start_outgoing_migration(MigrationState *s, const char *command, Error **errp) > > > +void init_exec_array(strList *command, const char *argv[], Error **errp) > > > +{ > > > + int i = 0; > > > + strList *lst; > > > + > > > + for (lst = command; lst ; lst = lst->next) { > > > + argv[i++] = lst->value; > > > + } > > > + > > > + /* > > > + * Considering exec command always has 3 arguments to execute > > > + * a command directly from the bash itself. > > > + */ > > > + if (i > 3) { > > > + error_setg(errp, "exec accepts maximum of 3 arguments in the list"); > > > + return; > > > + } > > By the time this check fires, the for() loop above has already > > done out of bounds writes on argv[]. > Ack. check should be before for loop. > > > + > > > + argv[i] = NULL; > > > + return; > > > +} > > > + > > > +void exec_start_outgoing_migration(MigrationState *s, strList *command, > > > + Error **errp) > > > { > > > QIOChannel *ioc; > > > - const char *argv[] = { "/bin/sh", "-c", command, NULL }; > > > + const char *argv[4]; > > > + init_exec_array(command, argv, errp); > > If someone invokes 'migrate' with the old URI style, the > > strList will be 3 elements, and thus argv[4] is safe. > > > > If someone invokes 'migrate' with thue new MigrateChannel style, > > the strList can be arbitrarily long and thus argv[4] will be > > risk of overflow. > > Okay, Can you give me an example where strList can be very long in the new > MigrateChannel ? because in that case, The new MigrateAddress struct allows the user to have arbitrary command args, so for example I would expect to be able to do { "execute": "migrate", "arguments": { "channel": { "channeltype": "main", "addr": { "transport": "exec", "exec": ["/bin/ssh", "-p", "6000", "-l", "root", "-o", "CheckHostIP=no", "-o", "ConnectTimeout=15", "somehost" ] } } } } > > trace_migration_exec_outgoing(argv[2]); > > will also be not correct right. Will have to come up with something that is > dynamic ? Yes, that will need addressing too. We already need to convert from strList to char ** in order to call qio_channel_command_new_spawn. Given that, you can use g_strjoinv(" ", argv) to generate a combined string that can be given to the trace func. With regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|