From patchwork Sun Sep 4 21:02:51 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 665560 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3sS5DV0399z9srY for ; Mon, 5 Sep 2016 07:12:58 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754244AbcIDVMy (ORCPT ); Sun, 4 Sep 2016 17:12:54 -0400 Received: from mx1.redhat.com ([209.132.183.28]:50646 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754142AbcIDVMv (ORCPT ); Sun, 4 Sep 2016 17:12:51 -0400 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 4455E4DB07; Sun, 4 Sep 2016 21:02:53 +0000 (UTC) Received: from warthog.procyon.org.uk (ovpn-116-66.phx2.redhat.com [10.3.116.66]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u84L2pQ9012499; Sun, 4 Sep 2016 17:02:52 -0400 Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 Subject: [PATCH net-next 4/9] rxrpc: Randomise epoch and starting client conn ID values From: David Howells To: netdev@vger.kernel.org Cc: dhowells@redhat.com, linux-afs@lists.infradead.org, linux-kernel@vger.kernel.org Date: Sun, 04 Sep 2016 22:02:51 +0100 Message-ID: <147302297165.28597.8317497494192917329.stgit@warthog.procyon.org.uk> In-Reply-To: <147302294435.28597.15007422228950187972.stgit@warthog.procyon.org.uk> References: <147302294435.28597.15007422228950187972.stgit@warthog.procyon.org.uk> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.68 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.29]); Sun, 04 Sep 2016 21:02:53 +0000 (UTC) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Create a random epoch value rather than a time-based one on startup and set the top bit to indicate that this is the case. Also create a random starting client connection ID value. This will be incremented from here as new client connections are created. Signed-off-by: David Howells --- include/rxrpc/packet.h | 1 + net/rxrpc/af_rxrpc.c | 9 ++++++++- 2 files changed, 9 insertions(+), 1 deletion(-) diff --git a/include/rxrpc/packet.h b/include/rxrpc/packet.h index b2017440b765..3c6128e1fdbe 100644 --- a/include/rxrpc/packet.h +++ b/include/rxrpc/packet.h @@ -24,6 +24,7 @@ typedef __be32 rxrpc_serial_net_t; /* on-the-wire Rx message serial number */ */ struct rxrpc_wire_header { __be32 epoch; /* client boot timestamp */ +#define RXRPC_RANDOM_EPOCH 0x80000000 /* Random if set, date-based if not */ __be32 cid; /* connection and channel ID */ #define RXRPC_MAXCALLS 4 /* max active calls per conn */ diff --git a/net/rxrpc/af_rxrpc.c b/net/rxrpc/af_rxrpc.c index 32d544995dda..b66a9e6f8d04 100644 --- a/net/rxrpc/af_rxrpc.c +++ b/net/rxrpc/af_rxrpc.c @@ -16,6 +16,7 @@ #include #include #include +#include #include #include #include @@ -700,7 +701,13 @@ static int __init af_rxrpc_init(void) BUILD_BUG_ON(sizeof(struct rxrpc_skb_priv) > FIELD_SIZEOF(struct sk_buff, cb)); - rxrpc_epoch = get_seconds(); + get_random_bytes(&rxrpc_epoch, sizeof(rxrpc_epoch)); + rxrpc_epoch |= RXRPC_RANDOM_EPOCH; + get_random_bytes(&rxrpc_client_conn_ids.cur, + sizeof(rxrpc_client_conn_ids.cur)); + rxrpc_client_conn_ids.cur &= 0x3fffffff; + if (rxrpc_client_conn_ids.cur == 0) + rxrpc_client_conn_ids.cur = 1; ret = -ENOMEM; rxrpc_call_jar = kmem_cache_create(