From patchwork Wed Jun 22 11:04:37 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [v2,1/2] ipv4: Fix packet size calculation in __ip_append_data Date: Wed, 22 Jun 2011 01:04:37 -0000 From: Steffen Klassert X-Patchwork-Id: 101433 Message-Id: <20110622110437.GG6489@secunet.com> To: David Miller , Eric Dumazet , Herbert Xu Cc: netdev@vger.kernel.org Git commit 59104f06 (ip: take care of last fragment in ip_append_data) added a check to see if we exceed the mtu when we add trailer_len. However, the mtu is already subtracted by the trailer length when the xfrm transfomation bundles are set up. So IPsec packets with mtu size get fragmented, or if the DF bit is set the packets will not be send even though they match the mtu perfectly fine. This patch actually reverts commit 59104f06. Signed-off-by: Steffen Klassert --- net/ipv4/ip_output.c | 7 ++----- 1 files changed, 2 insertions(+), 5 deletions(-) diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c index a8024ea..6b894d4 100644 --- a/net/ipv4/ip_output.c +++ b/net/ipv4/ip_output.c @@ -888,12 +888,9 @@ alloc_new_skb: * because we have no idea what fragment will be * the last. */ - if (datalen == length + fraggap) { + if (datalen == length + fraggap) alloclen += rt->dst.trailer_len; - /* make sure mtu is not reached */ - if (datalen > mtu - fragheaderlen - rt->dst.trailer_len) - datalen -= ALIGN(rt->dst.trailer_len, 8); - } + if (transhdrlen) { skb = sock_alloc_send_skb(sk, alloclen + hh_len + 15,