IPsec tunnel does not set ECN field to CE in inner header when
the ECN field in the outer header is CE, and the ECN field in
the inner header is ECT(0) or ECT(1).

The cause is ipip6_hdr() does not return the correct address of
inner header since skb->transport-header is not the inner header
after esp6_input_done2(), or ah6_input().

Signed-off-by: Li RongQing <roy.qing.li@gmail.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

Initialize return variable before exiting on an error path.

The initial initialization of the return variable is also dropped, because
that value is never used.

A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
(
if@p1 (\(ret < 0\|ret != 0\))
 { ... return ret; }
|
ret@p1 = 0
)
... when != ret = e1
    when != &ret
*if(...)
{
  ... when != ret = e2
      when forall
 return ret;
}

// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>

Signed-off-by: David S. Miller <davem@davemloft.net>

One tricky issue on the ipv6 side vs. ipv4 is that the ICMP callouts
to handle the error pass the 32-bit info cookie in network byte order
whereas ipv4 passes it around in host byte order.

Like the ipv4 side, we have two helper functions.  One for when we
have a socket context and one for when we do not.

ip6ip6 tunnels are not handled here, because they handle PMTU events
by essentially relaying another ICMP packet-too-big message back to
the original sender.

This patch allows us to get rid of rt6_do_pmtu_disc().  It handles all
kinds of situations that simply cannot happen when we do the PMTU
update directly using a fully resolved route.

In fact, the "plen == 128" check in ip6_rt_update_pmtu() can very
likely be removed or changed into a BUG_ON() check.  We should never
have a prefixed ipv6 route when we get there.

Another piece of strange history here is that TCP and DCCP, unlike in
ipv4, never invoke the update_pmtu() method from their ICMP error
handlers.  This is incredibly astonishing since this is the context
where we have the most accurate context in which to make a PMTU
update, namely we have a fully connected socket and associated cached
socket route.

Signed-off-by: David S. Miller <davem@davemloft.net>

Corrects the function that determines the esp payload size. The calculations
done in esp{4,6}_get_mtu() lead to overlength frames in transport mode for
certain mtu values and suboptimal frames for others.

According to what is done, mainly in esp{,6}_output() and tcp_mtu_to_mss(),
net_header_len must be taken into account before doing the alignment
calculation.

Signed-off-by: Benjamin Poirier <bpoirier@suse.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

Use the current debugging style and enable dynamic_debug.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add #define pr_fmt(fmt) as appropriate.

Add "IPv6: " to appropriate files.

Convert printk(KERN_<LEVEL> to pr_<level> (but not KERN_DEBUG).
Standardize on "%s: " not "%s(): " when emitting __func__.
Use "%s: ", __func__ instead of embedding function name.
Coalesce formats, align arguments.

ADDRCONF output is now prefixed with "IPv6: "

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Conflicts:
	drivers/net/tg3.c

When we use IPsec extended sequence numbers, we may overwrite
the last scatterlist of the associated data by the scatterlist
for the skb. This patch fixes this by placing the scatterlist
for the skb right behind the last scatterlist of the associated
data. esp4 does it already like that.

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add const qualifiers to structs iphdr, ipv6hdr and in6_addr pointers
where possible, to make code intention more obvious.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>