From patchwork Wed Jul 4 18:38:19 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Simon Wunderlich X-Patchwork-Id: 2138 Return-Path: Received: from cora.hrz.tu-chemnitz.de (cora.hrz.tu-chemnitz.de [134.109.228.40]) by open-mesh.org (Postfix) with ESMTPS id D6714600932 for ; Wed, 4 Jul 2012 20:38:06 +0200 (CEST) Authentication-Results: open-mesh.org; dkim=pass (1024-bit key; insecure key) header.i=@tu-chemnitz.de; dkim-adsp=none (insecure policy) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=tu-chemnitz.de; s=dkim2010; h=References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From; bh=fCZQcS1+vbN4uFL3ineqW6FUe83jAmmU+BgvmWl2so4=; b=IuO5goEUStEINUJ60UBx1fhhxd4uHqSl5t5BQAn4ixaE7rHjjWJk12QMH0mmpjwjvKtf/K4lWzkyMI8XiILE/b2MQaY4l6hjf8V95kPRMhsoLygadaA2OEAPvWuDUrgN8Fvc5kXHNRfm1ckKi+V3/7eUTcbutOoA5Y4HaZM/tM4=; Received: from p57aa19e2.dip0.t-ipconnect.de ([87.170.25.226] helo=pandem0nium) by cora.hrz.tu-chemnitz.de with esmtpsa (TLSv1:AES256-SHA:256) (Exim 4.76) (envelope-from ) id 1SmUSj-0004xX-OG; Wed, 04 Jul 2012 20:38:06 +0200 Received: from dotslash by pandem0nium with local (Exim 4.72) (envelope-from ) id 1SmUT0-0003Dz-0b; Wed, 04 Jul 2012 20:38:22 +0200 From: Simon Wunderlich To: b.a.t.m.a.n@lists.open-mesh.org Date: Wed, 4 Jul 2012 20:38:19 +0200 Message-Id: <1341427099-12368-1-git-send-email-siwu@hrz.tu-chemnitz.de> X-Mailer: git-send-email 1.7.2.5 In-Reply-To: References: X-Scan-AV: cora.hrz.tu-chemnitz.de; 2012-07-04 20:38:06; e045e6307db2ceb03a2b58e13168c95d X-Scan-SA: cora.hrz.tu-chemnitz.de; 2012-07-04 20:38:06; f79453ca1554357759088e13ff22d619 X-Spam-Score: -1.0 (-) X-Spam-Report: --- Textanalyse SpamAssassin 3.3.1 (-1.0 Punkte) Fragen an/questions to: Postmaster TU Chemnitz * -1.0 ALL_TRUSTED Passed through trusted hosts only via SMTP --- Ende Textanalyse Cc: Simon Wunderlich Subject: [B.A.T.M.A.N.] [PATCH-maint-v2] batman-adv: check incoming packet type for bla X-BeenThere: b.a.t.m.a.n@lists.open-mesh.org X-Mailman-Version: 2.1.13 Precedence: list Reply-To: The list for a Better Approach To Mobile Ad-hoc Networking List-Id: The list for a Better Approach To Mobile Ad-hoc Networking List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 04 Jul 2012 18:38:07 -0000 If the gateway functionality is used, some broadcast packets (DHCP requests) may be transmitted as unicast packets. As the bridge loop avoidance code now only considers the payload Ethernet destination, it may drop the DHCP request for clients which are claimed by other backbone gateways, because it falsely infers from the broadcast address that the right backbone gateway should havehandled the broadcast. Fix this by checking and delegating the batman-adv packet type used for transmission. Reported-by: Guido Iribarren Signed-off-by: Simon Wunderlich --- PATCHv2 adds a comment why we are doing this, and adds the is_bcast check to the other is_multicast_ether_addr() check in this function. PATCH-maint is the backport for maint PATCH-maint-v2 is even checkpatch clean, and remove obsolete !! --- bridge_loop_avoidance.c | 15 +++++++++++---- bridge_loop_avoidance.h | 5 +++-- soft-interface.c | 6 +++++- 3 files changed, 19 insertions(+), 7 deletions(-) diff --git a/bridge_loop_avoidance.c b/bridge_loop_avoidance.c index 8bf9751..c5863f4 100644 --- a/bridge_loop_avoidance.c +++ b/bridge_loop_avoidance.c @@ -1351,6 +1351,7 @@ void bla_free(struct bat_priv *bat_priv) * @bat_priv: the bat priv with all the soft interface information * @skb: the frame to be checked * @vid: the VLAN ID of the frame + * @is_bcast: the packet came in a broadcast packet type. * * bla_rx avoidance checks if: * * we have to race for a claim @@ -1361,7 +1362,8 @@ void bla_free(struct bat_priv *bat_priv) * process the skb. * */ -int bla_rx(struct bat_priv *bat_priv, struct sk_buff *skb, short vid) +int bla_rx(struct bat_priv *bat_priv, struct sk_buff *skb, short vid, + bool is_bcast) { struct ethhdr *ethhdr; struct claim search_claim, *claim = NULL; @@ -1380,7 +1382,7 @@ int bla_rx(struct bat_priv *bat_priv, struct sk_buff *skb, short vid) if (unlikely(atomic_read(&bat_priv->bla_num_requests))) /* don't allow broadcasts while requests are in flight */ - if (is_multicast_ether_addr(ethhdr->h_dest)) + if (is_multicast_ether_addr(ethhdr->h_dest) && is_bcast) goto handled; memcpy(search_claim.addr, ethhdr->h_source, ETH_ALEN); @@ -1406,8 +1408,13 @@ int bla_rx(struct bat_priv *bat_priv, struct sk_buff *skb, short vid) } /* if it is a broadcast ... */ - if (is_multicast_ether_addr(ethhdr->h_dest)) { - /* ... drop it. the responsible gateway is in charge. */ + if (is_multicast_ether_addr(ethhdr->h_dest) && is_bcast) { + /* ... drop it. the responsible gateway is in charge. + * + * We need to check is_bcast because with the gateway + * feature, broadcasts (like DHCP requests) may be sent + * using a unicast packet type. + */ goto handled; } else { /* seems the client considers us as its best gateway. diff --git a/bridge_loop_avoidance.h b/bridge_loop_avoidance.h index e39f93a..dc5227b 100644 --- a/bridge_loop_avoidance.h +++ b/bridge_loop_avoidance.h @@ -23,7 +23,8 @@ #define _NET_BATMAN_ADV_BLA_H_ #ifdef CONFIG_BATMAN_ADV_BLA -int bla_rx(struct bat_priv *bat_priv, struct sk_buff *skb, short vid); +int bla_rx(struct bat_priv *bat_priv, struct sk_buff *skb, short vid, + bool is_bcast); int bla_tx(struct bat_priv *bat_priv, struct sk_buff *skb, short vid); int bla_is_backbone_gw(struct sk_buff *skb, struct orig_node *orig_node, int hdr_size); @@ -41,7 +42,7 @@ void bla_free(struct bat_priv *bat_priv); #else /* ifdef CONFIG_BATMAN_ADV_BLA */ static inline int bla_rx(struct bat_priv *bat_priv, struct sk_buff *skb, - short vid) + short vid, bool is_bcast) { return 0; } diff --git a/soft-interface.c b/soft-interface.c index 6e2530b..a0ec0e4 100644 --- a/soft-interface.c +++ b/soft-interface.c @@ -256,7 +256,11 @@ void interface_rx(struct net_device *soft_iface, struct bat_priv *bat_priv = netdev_priv(soft_iface); struct ethhdr *ethhdr; struct vlan_ethhdr *vhdr; + struct batman_header *batadv_header = (struct batman_header *)skb->data; short vid __maybe_unused = -1; + bool is_bcast; + + is_bcast = (batadv_header->packet_type == BAT_BCAST); /* check if enough space is available for pulling, and pull */ if (!pskb_may_pull(skb, hdr_size)) @@ -302,7 +306,7 @@ void interface_rx(struct net_device *soft_iface, /* Let the bridge loop avoidance check the packet. If will * not handle it, we can safely push it up. */ - if (bla_rx(bat_priv, skb, vid)) + if (bla_rx(bat_priv, skb, vid, is_bcast)) goto out; netif_rx(skb);