The current placement of the security_inet_conn_request() hooks do not allow
individual LSMs to override the IP options of the connection's request_sock.
This is a problem as both SELinux and Smack have the ability to use labeled
networking protocols which make use of IP options to carry security attributes
and the inability to set the IP options at the start of the TCP handshake is
problematic.

This patch moves the IPv4 security_inet_conn_request() hooks past the code
where the request_sock's IP options are set/reset so that the LSM can safely
manipulate the IP options as needed.  This patch intentionally does not change
the related IPv6 hooks as IPv6 based labeling protocols which use IPv6 options
are not currently implemented, once they are we will have a better idea of
the correct placement for the IPv6 hooks.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: James Morris <jmorris@namei.org>

Current TCP code relies on the local port of the listening socket
being the same as the destination address of the incoming
connection. Port redirection used by many transparent proxying
techniques obviously breaks this, so we have to store the original
destination port address.

This patch extends struct inet_request_sock and stores the incoming
destination port value there. It also modifies the handshake code to
use that value as the source port when sending reply packets.

Signed-off-by: KOVACS Krisztian <hidden@sch.bme.hu>
Signed-off-by: David S. Miller <davem@davemloft.net>

Netfilter's ip_route_me_harder() tries to re-route packets either
generated or re-routed by Netfilter. This patch changes
ip_route_me_harder() to handle packets from non-locally-bound sockets
with IP_TRANSPARENT set as local and to set the appropriate flowi
flags when re-doing the routing lookup.

Signed-off-by: KOVACS Krisztian <hidden@sch.bme.hu>
Signed-off-by: David S. Miller <davem@davemloft.net>

ecn_ok is not initialized when a connection is established by cookies.
The cookie syn-ack never sets ECN, so ecn_ok must be set to 0.

Spotted using ns-3/network simulation cradle simulator and valgrind.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Conflicts:

	drivers/net/smc911x.c

This patch removes CVS keywords that weren't updated for a long time
from comments.

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Wei Yongjun noticed that we may call reqsk_free on request sock objects where
the opt fields may not be initialized, fix it by introducing inet_reqsk_alloc
where we initialize ->opt to NULL and set ->pktopts to NULL in
inet6_reqsk_alloc.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Allow the use of SACK and window scaling when syncookies are used
and the client supports tcp timestamps. Options are encoded into
the timestamp sent in the syn-ack and restored from the timestamp
echo when the ack is received.

Based on earlier work by Glenn Griffin.
This patch avoids increasing the size of structs by encoding TCP
options into the least significant bits of the timestamp and
by not using any 'timestamp offset'.

The downside is that the timestamp sent in the packet after the synack
will increase by several seconds.

changes since v1:
 don't duplicate timestamp echo decoding function, put it into ipv4/syncookie.c
 and have ipv6/syncookies.c use it.
 Feedback from Glenn Griffin: fix line indented with spaces, kill redundant if ()

Reviewed-by: Hagen Paul Pfeifer <hagen@jauu.net>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

the first u32 copied from syncookie_secret is overwritten by the
minute-counter four lines below.  After adjusting the destination
address, the size of syncookie_secret can be reduced accordingly.

AFAICS, the only other user of syncookie_secret[] is the ipv6
syncookie support.  Because ipv6 syncookies only grab 44 bytes from
syncookie_secret[], this shouldn't affect them in any way.

With fixes from Glenn Griffin.

Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Glenn Griffin <ggriffin.kernel@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>