From patchwork Tue Jun 30 21:45:26 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Linus_L=C3=BCssing?= X-Patchwork-Id: 4563 Return-Path: Received-SPF: None (no SPF record) identity=mailfrom; client-ip=188.40.49.9; helo=mail.passe0815.de; envelope-from=linus.luessing@c0d3.blue; receiver=b.a.t.m.a.n@lists.open-mesh.org Received: from mail.passe0815.de (mail.passe0815.de [188.40.49.9]) by open-mesh.org (Postfix) with ESMTPS id 3118B6006A4 for ; Tue, 30 Jun 2015 23:45:30 +0200 (CEST) Received: from mail.passe0815.de (localhost [127.0.0.1]) by mail.passe0815.de (Postfix) with ESMTP id 0302B58676D for ; Tue, 30 Jun 2015 23:45:28 +0200 (CEST) Received: from localhost (unknown [IPv6:2a01:170:1112:0:89ff:1422:275c:4356]) (using TLSv1.2 with cipher DHE-RSA-AES128-SHA (128/128 bits)) (No client certificate requested) by mail.passe0815.de (Postfix) with ESMTPSA id E60BD586769; Tue, 30 Jun 2015 23:45:26 +0200 (CEST) From: =?UTF-8?q?Linus=20L=C3=BCssing?= To: b.a.t.m.a.n@lists.open-mesh.org Date: Tue, 30 Jun 2015 23:45:26 +0200 Message-Id: <1435700726-6607-1-git-send-email-linus.luessing@c0d3.blue> X-Mailer: git-send-email 1.9.1 MIME-Version: 1.0 X-GPG-Mailgate: Not encrypted, public key not found Subject: [B.A.T.M.A.N.] [PATCH maint] batman-adv: Fix potentially broken skb network header access X-BeenThere: b.a.t.m.a.n@lists.open-mesh.org X-Mailman-Version: 2.1.15 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: Tue, 30 Jun 2015 21:45:31 -0000 The two commits noted below added calls to ip_hdr() and ipv6_hdr(). They need a correctly set skb network header. Unfortunately we cannot rely on the device drivers to set it for us. Therefore setting it in the beginning of the according ndo_start_xmit handler. Fixes: 405cc1e5 ("batman-adv: Modified forwarding behaviour for multicast packets") Fixes: 1c090349 ("batman-adv: Add IPv4 link-local/IPv6-ll-all-nodes multicast support") Signed-off-by: Linus Lüssing --- Three notes: * Pending question on netdev, we should probably wait a few more days before applying this patch. * Back in Nov. 2014 for the original multicast bridge patchset Simon suggested moving the skb_set_network_header() call to within the according multicast functions: https://lists.open-mesh.org/pipermail/b.a.t.m.a.n/2014-November/012573.html I would like to submit patches for master afterwards though to change some raw skb->data access and hdr_size math to skb_network_header() calls as I think they might be easier to read and safer. (for skb->data you always have to go back the whole call chain and check for any skb pulls etc. to know where skb->data points to, same for hdr_size to know it's value as it's passed through mutliple layers of functions) So I thought it'd be good to have the skb_set_network_header() in a good place for that already. * The "network_offset += VETH_HLEN" is not strictly necessary since the multicast optimizations won't apply for vlans yet and the ip_hdr()/ipv6_hdr() calls are never reached in that case. But again, I thought it would be cleaner that way. soft-interface.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/soft-interface.c b/soft-interface.c index 7841a4b..eb87fd9 100644 --- a/soft-interface.c +++ b/soft-interface.c @@ -178,6 +178,7 @@ static int batadv_interface_tx(struct sk_buff *skb, int gw_mode; enum batadv_forw_mode forw_mode; struct batadv_orig_node *mcast_single_orig = NULL; + int network_offset = ETH_HLEN; if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE) goto dropped; @@ -190,14 +191,18 @@ static int batadv_interface_tx(struct sk_buff *skb, case ETH_P_8021Q: vhdr = vlan_eth_hdr(skb); - if (vhdr->h_vlan_encapsulated_proto != ethertype) + if (vhdr->h_vlan_encapsulated_proto != ethertype) { + network_offset += VLAN_HLEN; break; + } /* fall through */ case ETH_P_BATMAN: goto dropped; } + skb_set_network_header(skb, network_offset); + if (batadv_bla_tx(bat_priv, skb, vid)) goto dropped;