Commit 33f99dc7 authored Jun 22, 2011 by Steffen Klassert Committed by David S. Miller Jun 27, 2011

ipv4: Fix packet size calculation in __ip_append_data



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 <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent d6fe5f4e

net/ipv4/ip_output.c

+2 −5

Original line number	Diff line number	Diff line
		@@ -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,

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