[PATCH] net/core: Make urgent data inline by default

[PATCH] net/core: Make urgent data inline by default

[Esa-Pekka Pyokkimies]

Make urgent data inline by default. As explained in RFC 6093, urgent
data should never be handled out-of-band.

"The TCP urgent mechanism is NOT a mechanism for sending "out-of-band"
  data: the so-called "urgent data" should be delivered "in-line" to
  the TCP user."

Signed-off-by: Esa-Pekka Pyokkimies <esa-pekka.pyokkimies@stonesoft.com>

---
  net/core/sock.c |    1 +
  1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/net/core/sock.c b/net/core/sock.c
index 6e81978..83234bd 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1985,6 +1985,7 @@ void sock_init_data(struct socket *sock, struct sock  
*sk)
         sk_set_socket(sk, sock);

         sock_set_flag(sk, SOCK_ZAPPED);
+	sock_set_flag(sk, SOCK_URGINLINE);

         if (sock) {
                 sk->sk_type     =       sock->type;

Re: [PATCH] net/core: Make urgent data inline by default

[David Miller]

From: Esa-Pekka Pyokkimies <esa-pekka.pyokkimies@stonesoft.com>
Date: Mon, 4 Jul 2011 15:51:06 +0300

> Make urgent data inline by default. As explained in RFC 6093, urgent
> data should never be handled out-of-band.
> 
> "The TCP urgent mechanism is NOT a mechanism for sending "out-of-band"
>  data: the so-called "urgent data" should be delivered "in-line" to
>  the TCP user."
> 
> Signed-off-by: Esa-Pekka Pyokkimies
> <esa-pekka.pyokkimies@stonesoft.com>

There is no way we can make this change, we've had the default
we currently have for 18+ years.  Breaking applications is a
very real possibility.

It doesn't matter what some RFC says.

Re: [PATCH] net/core: Make urgent data inline by default

[Esa-Pekka Pyokkimies]

On Tue, 05 Jul 2011 02:38:38 +0300, David Miller <davem@davemloft.net>  
wrote:

> There is no way we can make this change, we've had the default
> we currently have for 18+ years.  Breaking applications is a
> very real possibility.
>
> It doesn't matter what some RFC says.

I understand. However urgent pointer is a very niche feature and I don't  
think
it would really break much. FTP and telnet both want the urgent data inline
anyway. I haven't found any application which uses the "1-byte" urgent  
data,
which can by some change be overwritten by the next urgent data if you  
didn't
read it in time. The reason I would want this change is that attack  
detection
is very difficult when there can be a byte missing due to URG flag being  
set,
and the damage done by crackers is more than the damage to applications I  
think.
But I guess you decide. Atleast I tried.

Esa-Pekka