From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg Kroah-Hartman , alan@lxorguk.ukuu.org.uk, =?ISO-8859-15?q?Linus=20L=C3=BCssing?= , Simon Wunderlich , Marek Lindner Subject: =?UTF-8?q?=5B=2033/66=5D=20batman-adv=3A=20Fix=20broadcast=20packet=20CRC=20calculation?= Date: Wed, 14 Nov 2012 20:10:38 -0800 Message-Id: <20121115040941.394047398@linuxfoundation.org> In-Reply-To: <20121115040939.016421011@linuxfoundation.org> References: <20121115040939.016421011@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Linus Lüssing commit 7f112af40fecf5399b61e69ffc6b55a9d82789f7 upstream. So far the crc16 checksum for a batman-adv broadcast data packet, received on a batman-adv hard interface, was calculated over zero bytes of its content leading to many incoming broadcast data packets wrongly being dropped (60-80% packet loss). This patch fixes this issue by calculating the crc16 over the actual, complete broadcast payload. The issue is a regression introduced by ("batman-adv: add broadcast duplicate check"). Signed-off-by: Linus Lüssing Acked-by: Simon Wunderlich Signed-off-by: Marek Lindner Signed-off-by: Greg Kroah-Hartman --- net/batman-adv/bridge_loop_avoidance.c | 8 ++++---- net/batman-adv/routing.c | 8 +++++++- 2 files changed, 11 insertions(+), 5 deletions(-) --- a/net/batman-adv/bridge_loop_avoidance.c +++ b/net/batman-adv/bridge_loop_avoidance.c @@ -1205,8 +1205,8 @@ int batadv_bla_init(struct batadv_priv * /** * batadv_bla_check_bcast_duplist * @bat_priv: the bat priv with all the soft interface information - * @bcast_packet: originator mac address - * @hdr_size: maximum length of the frame + * @bcast_packet: encapsulated broadcast frame plus batman header + * @bcast_packet_len: length of encapsulated broadcast frame plus batman header * * check if it is on our broadcast list. Another gateway might * have sent the same packet because it is connected to the same backbone, @@ -1219,14 +1219,14 @@ int batadv_bla_init(struct batadv_priv * */ int batadv_bla_check_bcast_duplist(struct batadv_priv *bat_priv, struct batadv_bcast_packet *bcast_packet, - int hdr_size) + int bcast_packet_len) { int i, length, curr; uint8_t *content; uint16_t crc; struct batadv_bcast_duplist_entry *entry; - length = hdr_size - sizeof(*bcast_packet); + length = bcast_packet_len - sizeof(*bcast_packet); content = (uint8_t *)bcast_packet; content += sizeof(*bcast_packet); --- a/net/batman-adv/routing.c +++ b/net/batman-adv/routing.c @@ -1136,8 +1136,14 @@ int batadv_recv_bcast_packet(struct sk_b spin_unlock_bh(&orig_node->bcast_seqno_lock); + /* keep skb linear for crc calculation */ + if (skb_linearize(skb) < 0) + goto out; + + bcast_packet = (struct batadv_bcast_packet *)skb->data; + /* check whether this has been sent by another originator before */ - if (batadv_bla_check_bcast_duplist(bat_priv, bcast_packet, hdr_size)) + if (batadv_bla_check_bcast_duplist(bat_priv, bcast_packet, skb->len)) goto out; /* rebroadcast packet */