Commit 61e7f09d authored Dec 19, 2013 by Hannes Frederic Sowa Committed by David S. Miller Dec 22, 2013

ipv4: consistent reporting of pmtu data in case of corking



We report different pmtu values back on the first write and on further
writes on an corked socket.

Also don't include the dst.header_len (respectively exthdrlen) as this
should already be dealt with by the interface mtu of the outgoing
(virtual) interface and policy of that interface should dictate if
fragmentation should happen.

Instead reduce the pmtu data by IP options as we do for IPv6. Make the
same changes for ip_append_data, where we did not care about options or
dst.header_len at all.

Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent db850559

net/ipv4/ip_output.c

+3 −2

Original line number	Diff line number	Diff line
		@@ -828,7 +828,7 @@ static int __ip_append_data(struct sock *sk,

		if (cork->length + length > maxnonfragsize - fragheaderlen) {
		ip_local_error(sk, EMSGSIZE, fl4->daddr, inet->inet_dport,
		mtu-exthdrlen);
		mtu - (opt ? opt->optlen : 0));
		return -EMSGSIZE;
		}

		@@ -1151,7 +1151,8 @@ ssize_t ip_append_page(struct sock sk, struct flowi4 fl4, struct page *page,
		mtu : 0xFFFF;

		if (cork->length + size > maxnonfragsize - fragheaderlen) {
		ip_local_error(sk, EMSGSIZE, fl4->daddr, inet->inet_dport, mtu);
		ip_local_error(sk, EMSGSIZE, fl4->daddr, inet->inet_dport,
		mtu - (opt ? opt->optlen : 0));
		return -EMSGSIZE;
		}

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