From mboxrd@z Thu Jan 1 00:00:00 1970 From: bernard pidoux Subject: [PATCH 3/3] [NETROM] zero length frame filtering in NetRom Date: Thu, 19 Mar 2009 19:18:52 +0100 Message-ID: <1237486732.30285.18.camel@f6bvp-11> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit To: Linux netdev , Linux Hams , David Miller Return-path: Received: from smtp2-g21.free.fr ([212.27.42.2]:44369 "EHLO smtp2-g21.free.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754946AbZCSSfs (ORCPT ); Thu, 19 Mar 2009 14:35:48 -0400 Sender: netdev-owner@vger.kernel.org List-ID: A zero length frame filter was recently introduced in ROSE protocole. Previous commit makes the same at AX25 protocole level. This patch has the same purpose for NetRom protocole. The reason is that empty frames have no meaning in NetRom protocole. Signed-off-by: Bernard Pidoux --- net/netrom/af_netrom.c | 11 ++++++++++- 1 files changed, 10 insertions(+), 1 deletions(-) diff --git a/net/netrom/af_netrom.c b/net/netrom/af_netrom.c index e9c05b8..ec6c898 100644 --- a/net/netrom/af_netrom.c +++ b/net/netrom/af_netrom.c @@ -1037,6 +1037,10 @@ static int nr_sendmsg(struct kiocb *iocb, struct socket *sock, unsigned char *asmptr; int size; + /* Netrom 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; @@ -1167,6 +1171,11 @@ static int nr_recvmsg(struct kiocb *iocb, struct socket *sock, skb_reset_transport_header(skb); copied = skb->len; + /* NetRom empty data frame has no meaning : ignore it */ + if (copied == 0) { + goto out; + } + if (copied > size) { copied = size; msg->msg_flags |= MSG_TRUNC; @@ -1182,7 +1191,7 @@ static int nr_recvmsg(struct kiocb *iocb, struct socket *sock, msg->msg_namelen = sizeof(*sax); - skb_free_datagram(sk, skb); +out: skb_free_datagram(sk, skb); release_sock(sk); return copied; -- 1.6.0.6