From patchwork Mon Feb 13 19:44:31 2017 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: 16946 X-Patchwork-Delegate: sw@simonwunderlich.de Return-Path: X-Original-To: patchwork@open-mesh.org Delivered-To: patchwork@open-mesh.org Received: from open-mesh.org (localhost [IPv6:::1]) by open-mesh.org (Postfix) with ESMTP id 536DE83556; Mon, 13 Feb 2017 20:44:36 +0100 (CET) Authentication-Results: open-mesh.org; dmarc=none header.from=c0d3.blue Received: from mail.aperture-lab.de (mail.aperture-lab.de [IPv6:2a01:4f8:171:314c::100:a1]) by open-mesh.org (Postfix) with ESMTPS id E5D29834F0 for ; Mon, 13 Feb 2017 20:44:34 +0100 (CET) Authentication-Results: open-mesh.org; dmarc=none header.from=c0d3.blue Received: from localhost (localhost [127.0.0.1]) by mail.aperture-lab.de (Postfix) with ESMTP id 25AF9E0796; Mon, 13 Feb 2017 20:44:35 +0100 (CET) X-Virus-Scanned: Debian amavisd-new at aperture-lab.de Received: from mail.aperture-lab.de ([127.0.0.1]) by localhost (mail.aperture-lab.de [127.0.0.1]) (amavisd-new, port 10025) with ESMTP id qJC7SKOqnIDH; Mon, 13 Feb 2017 20:44:34 +0100 (CET) Received: from localhost (unknown [IPv6:2001:67c:2d50:0:c85:8cff:fe0f:63fe]) (Authenticated sender: linus.luessing@c0d3.blue) by mail.aperture-lab.de (Postfix) with ESMTPSA; Mon, 13 Feb 2017 20:44:34 +0100 (CET) From: =?utf-8?q?Linus_L=C3=BCssing?= To: b.a.t.m.a.n@lists.open-mesh.org Date: Mon, 13 Feb 2017 20:44:31 +0100 Message-Id: <20170213194431.24075-1-linus.luessing@c0d3.blue> X-Mailer: git-send-email 2.11.0 MIME-Version: 1.0 Subject: [B.A.T.M.A.N.] [PATCH maint] batman-adv: Fix transmission of final, 16th fragment X-BeenThere: b.a.t.m.a.n@lists.open-mesh.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: The list for a Better Approach To Mobile Ad-hoc Networking List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: The list for a Better Approach To Mobile Ad-hoc Networking Errors-To: b.a.t.m.a.n-bounces@lists.open-mesh.org Sender: "B.A.T.M.A.N" Trying to split and transmit a unicast packet in 16 parts will fail for the final fragment: After having sent the 15th one with a frag_packet.no index of 14, we will increase the the index to 15 - and return with an error code immediately, even though one more fragment is due for transmission and allowed. Fixing this issue by moving the check before incrementing the index. While at it, adding an unlikely(), because the check is actually more of an assertion. Signed-off-by: Linus Lüssing Reviewed-by: Sven Eckelmann --- Compile time tested only --- net/batman-adv/fragmentation.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/net/batman-adv/fragmentation.c b/net/batman-adv/fragmentation.c index 0854ebd..f181868 100644 --- a/net/batman-adv/fragmentation.c +++ b/net/batman-adv/fragmentation.c @@ -499,6 +499,12 @@ int batadv_frag_send_packet(struct sk_buff *skb, /* Eat and send fragments from the tail of skb */ while (skb->len > max_fragment_size) { + /* The initial check in this function should cover this case */ + if (unlikely(frag_header.no == BATADV_FRAG_MAX_FRAGMENTS - 1)) { + ret = -EINVAL; + goto put_primary_if; + } + skb_fragment = batadv_frag_create(skb, &frag_header, mtu); if (!skb_fragment) { ret = -ENOMEM; @@ -515,12 +521,6 @@ int batadv_frag_send_packet(struct sk_buff *skb, } frag_header.no++; - - /* The initial check in this function should cover this case */ - if (frag_header.no == BATADV_FRAG_MAX_FRAGMENTS - 1) { - ret = -EINVAL; - goto put_primary_if; - } } /* Make room for the fragment header. */