On Linux, when an interface goes down all its IPv6
addresses are deleted, so relying on knowing the previous
IPv6 addresses on the interface is brittle. Instead,
support nuking all sockets that are bound to IP addresses
that are not configured and up on the system. This
behaviour is triggered by specifying the unspecified
address (:: or 0.0.0.0). If an IP address is specified, the
behaviour is unchanged, except the ioctl now supports IPv6
as well as IPv4.

Signed-off-by: Lorenzo Colitti <lorenzo@google.com>

Conflicts:
	arch/arm/mm/cache-v6.S

Change-Id: I1a2063218dd705a762a40f4a9dfe504ce1a1d491

[ Upstream commit f19872575ff7819a3723154657a497d9bca66b33 ]

Make sure sysctl_tcp_cookie_size is read once in
tcp_cookie_size_check(), or we might return an illegal value to caller
if sysctl_tcp_cookie_size is changed by another cpu.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Ben Hutchings <bhutchings@solarflare.com>
Cc: William Allen Simpson <william.allen.simpson@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

[ Upstream commit ad9f4f50fe9288bbe65b7dfd76d8820afac6a24c ]

sysctl_tcp_tso_win_divisor might be set to zero while one cpu runs in
tcp_tso_should_defer(). Make sure we dont allow a divide by zero by
reading sysctl_tcp_tso_win_divisor exactly once.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

[ Upstream commit b1afde60f2b9ee8444fba4e012dc99a3b28d224d ]

The bug has to do with boundary checks on the initial receive window.
If the initial receive window falls between init_cwnd and the
receive window specified by the user, the initial window is incorrectly
brought down to init_cwnd. The correct behavior is to allow it to
remain unchanged.

Signed-off-by: Nandita Dukkipati <nanditad@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

[ Upstream commit c39508d6f118308355468314ff414644115a07f3 ]

Use TCP_MIN_MSS instead of constant 64.

Reported-by: Min Zhang <mzhang@mvista.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

[ Upstream commit 7a1abd08d52fdeddb3e9a5a33f2f15cc6a5674d2 ]

As noted by Steve Chen, since commit
f5fff5dc8a7a3f395b0525c02ba92c95d42b7390 ("tcp: advertise MSS
requested by user") we can end up with a situation where
tcp_select_initial_window() does a divide by a zero (or
even negative) mss value.

The problem is that sometimes we effectively subtract
TCPOLEN_TSTAMP_ALIGNED and/or TCPOLEN_MD5SIG_ALIGNED from the mss.

Fix this by increasing the minimum from 8 to 64.

Reported-by: Steve Chen <schen@mvista.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

[ Upstream commit 8f49c2703b33519aaaccc63f571b465b9d2b3a2d ]

Alexey Kuznetsov noticed a regression introduced by
commit f1ecd5d9e7366609d640ff4040304ea197fbc618
("Revert Backoff [v3]: Revert RTO on ICMP destination unreachable")

The RTO and timer modification code added to tcp_v4_err()
doesn't check sock_owned_by_user(), which if true means we
don't have exclusive access to the socket and therefore cannot
modify it's critical state.

Just skip this new code block if sock_owned_by_user() is true
and eliminate the now superfluous sock_owned_by_user() code
block contained within.

Reported-by: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
CC: Damian Lukowski <damian@tvk.rwth-aachen.de>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>