From patchwork Sat Jan 29 21:47:29 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sven Eckelmann X-Patchwork-Id: 747 Return-Path: Received: from v3-1039.vlinux.de (narfation.org [79.140.41.39]) by open-mesh.org (Postfix) with ESMTPS id 86C6A154629 for ; Sat, 29 Jan 2011 22:47:57 +0100 (CET) Received: from sven-desktop.home.narfation.org (unknown [88.130.181.181]) by v3-1039.vlinux.de (Postfix) with ESMTPSA id D8CB094057; Sat, 29 Jan 2011 22:48:29 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=narfation.org; s=mail; t=1296337710; bh=cqS0o23T2txqAPwZlfRme+ObMlVhsYXhz/5fp+Yw2IY=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References; b=OQaQjw27eiMM5M2LO/XviCKSIEx9jOgeDWgXmBzJzHEMMyexvGsOKhmU5k/p/riJt hswZsw7QKV7cH6IN+ibHOetPRioIOHN8KAJrSkydGpenp9EGu8NEBuU5pzijnzX2SE 07NIAf2FkBV+qz77Z5awrntjX8S/kJS5Hq3k1Io8= From: Sven Eckelmann To: davem@davemloft.net Date: Sat, 29 Jan 2011 22:47:29 +0100 Message-Id: <1296337660-12376-3-git-send-email-sven@narfation.org> X-Mailer: git-send-email 1.7.2.3 In-Reply-To: <1296337660-12376-1-git-send-email-sven@narfation.org> References: <1296337660-12376-1-git-send-email-sven@narfation.org> Cc: netdev@vger.kernel.org, b.a.t.m.a.n@lists.open-mesh.org Subject: [B.A.T.M.A.N.] [PATCH 02/13] batman-adv: Create roughly equal sized fragments X-BeenThere: b.a.t.m.a.n@lists.open-mesh.org X-Mailman-Version: 2.1.11 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: Sat, 29 Jan 2011 21:47:57 -0000 The routing algorithm must know how large two fragments are to be able to decide that it is safe to merge them or if it should resubmit without waiting for the second part. When these two fragments have a too different size, it is not possible to guess right in every situation. The user could easily configure the MTU of the attached cards so that one fragment is forwarded and the other one is added to the fragments table to wait for the missing part. For even sized packets, it is possible to split it so that the resulting packages are equal sized by ignoring the old non-fragment header at the beginning of the original packet. This still creates different sized fragments for uneven sized packets. Reported-by: Russell Senior Reported-by: Marek Lindner Signed-off-by: Sven Eckelmann --- net/batman-adv/unicast.c | 5 +++-- 1 files changed, 3 insertions(+), 2 deletions(-) diff --git a/net/batman-adv/unicast.c b/net/batman-adv/unicast.c index ee41fef..811f7fc 100644 --- a/net/batman-adv/unicast.c +++ b/net/batman-adv/unicast.c @@ -224,7 +224,7 @@ int frag_send_skb(struct sk_buff *skb, struct bat_priv *bat_priv, struct unicast_frag_packet *frag1, *frag2; int uc_hdr_len = sizeof(struct unicast_packet); int ucf_hdr_len = sizeof(struct unicast_frag_packet); - int data_len = skb->len; + int data_len = skb->len - uc_hdr_len; if (!bat_priv->primary_if) goto dropped; @@ -232,10 +232,11 @@ int frag_send_skb(struct sk_buff *skb, struct bat_priv *bat_priv, frag_skb = dev_alloc_skb(data_len - (data_len / 2) + ucf_hdr_len); if (!frag_skb) goto dropped; + skb_reserve(frag_skb, ucf_hdr_len); unicast_packet = (struct unicast_packet *) skb->data; memcpy(&tmp_uc, unicast_packet, uc_hdr_len); - skb_split(skb, frag_skb, data_len / 2); + skb_split(skb, frag_skb, data_len / 2 + uc_hdr_len); if (my_skb_head_push(skb, ucf_hdr_len - uc_hdr_len) < 0 || my_skb_head_push(frag_skb, ucf_hdr_len) < 0)