linux-toradex.git/net/ipv4/syncookies.c, branch v3.0.29

tcp: fix syncookie regression

2012-03-23T18:20:51+00:00

[ Upstream commit dfd25ffffc132c00070eed64200e8950da5d7e9d ]

commit ea4fc0d619 (ipv4: Don't use rt->rt_{src,dst} in ip_queue_xmit())
added a serious regression on synflood handling.

Simon Kirby discovered a successful connection was delayed by 20 seconds
before being responsive.

In my tests, I discovered that xmit frames were lost, and needed ~4
retransmits and a socket dst rebuild before being really sent.

In case of syncookie initiated connection, we use a different path to
initialize the socket dst, and inet->cork.fl.u.ip4 is left cleared.

As ip_queue_xmit() now depends on inet flow being setup, fix this by
copying the temp flowi4 we use in cookie_v4_check().

Reported-by: Simon Kirby 
Bisected-by: Simon Kirby 
Signed-off-by: Eric Dumazet 
Tested-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

tcp: initialize variable ecn_ok in syncookies path

2011-10-03T18:40:54+00:00

[ Upstream commit f0e3d0689da401f7d1981c2777a714ba295ea5ff ]

Using a gcc 4.4.3, warnings are emitted for a possibly uninitialized use
of ecn_ok.

This can happen if cookie_check_timestamp() returns due to not having
seen a timestamp.  Defaulting to ecn off seems like a reasonable thing
to do in this case, so initialized ecn_ok to false.

Signed-off-by: Mike Waychison 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

inet: add RCU protection to inet->opt

2011-04-28T20:16:35+00:00

We lack proper synchronization to manipulate inet->opt ip_options

Problem is ip_make_skb() calls ip_setup_cork() and
ip_setup_cork() possibly makes a copy of ipc->opt (struct ip_options),
without any protection against another thread manipulating inet->opt.

Another thread can change inet->opt pointer and free old one under us.

Use RCU to protect inet->opt (changed to inet->inet_opt).

Instead of handling atomic refcounts, just copy ip_options when
necessary, to avoid cache line dirtying.

We cant insert an rcu_head in struct ip_options since its included in
skb->cb[], so this patch is large because I had to introduce a new
ip_options_rcu structure.

Signed-off-by: Eric Dumazet 
Cc: Herbert Xu 
Signed-off-by: David S. Miller

ipv4: Use flowi4_init_output() in cookie_v4_check()

2011-03-31T11:54:08+00:00

Signed-off-by: David S. Miller

net: Put fl4_* macros to struct flowi4 and use them again.

2011-03-12T23:08:54+00:00

Signed-off-by: David S. Miller

ipv4: Use flowi4 in public route lookup interfaces.

2011-03-12T23:08:48+00:00

Signed-off-by: David S. Miller

net: Make flowi ports AF dependent.

2011-03-12T23:08:46+00:00

Create two sets of port member accessors, one set prefixed by fl4_*
and the other prefixed by fl6_*

This will let us to create AF optimal flow instances.

It will work because every context in which we access the ports,
we have to be fully aware of which AF the flowi is anyways.

Signed-off-by: David S. Miller

net: Put flowi_* prefix on AF independent members of struct flowi

2011-03-12T23:08:44+00:00

I intend to turn struct flowi into a union of AF specific flowi
structs.  There will be a common structure that each variant includes
first, much like struct sock_common.

This is the first step to move in that direction.

Signed-off-by: David S. Miller

ipv4: Make output route lookup return rtable directly.

2011-03-02T22:31:35+00:00

Instead of on the stack.

Signed-off-by: David S. Miller

net: use the macros defined for the members of flowi

2010-11-17T20:27:45+00:00

Use the macros defined for the members of flowi to clean the code up.

Signed-off-by: Changli Gao 
Signed-off-by: David S. Miller