From mboxrd@z Thu Jan 1 00:00:00 1970 From: bernard pidoux Subject: [PATCH 2/3] [AX25] zero length frame filtering in AX25 Date: Thu, 19 Mar 2009 19:18:15 +0100 Message-ID: <1237486695.30285.17.camel@f6bvp-11> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit To: Linux netdev , David Miller Return-path: Received: from smtp5-g21.free.fr ([212.27.42.5]:42775 "EHLO smtp5-g21.free.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753474AbZCSSe0 (ORCPT ); Thu, 19 Mar 2009 14:34:26 -0400 Sender: netdev-owner@vger.kernel.org List-ID: In previous commit 244f46ae6e9e18f6fc0be7d1f49febde4762c34b was introduced a zero length frame filter for ROSE protocole. This patch has the same purpose at AX25 frame level for the same reason. Empty frames have no meaning in AX25 protocole. Signed-off-by: Bernard Pidoux --- net/ax25/af_ax25.c | 12 ++++++++++++ 1 files changed, 12 insertions(+), 0 deletions(-) diff --git a/net/ax25/af_ax25.c b/net/ax25/af_ax25.c index 532a031..ca32f57 100644 --- a/net/ax25/af_ax25.c +++ b/net/ax25/af_ax25.c @@ -1435,6 +1435,11 @@ static int ax25_sendmsg(struct kiocb *iocb, struct socket *sock, size_t size; int lv, err, addr_len = msg->msg_namelen; + /* AX.25 empty data frame has no meaning : don't send */ + if (len == 0) { + return (0); + } + if (msg->msg_flags & ~(MSG_DONTWAIT|MSG_EOR|MSG_CMSG_COMPAT)) return -EINVAL; @@ -1634,6 +1639,13 @@ static int ax25_recvmsg(struct kiocb *iocb, struct socket *sock, skb_reset_transport_header(skb); copied = skb->len; + /* AX.25 empty data frame has no meaning : ignore it */ + if (copied == 0) { + err = copied; + skb_free_datagram(sk, skb); + goto out; + } + if (copied > size) { copied = size; msg->msg_flags |= MSG_TRUNC; -- 1.6.0.6