net: avoid to hang up on sending due to sysctl configuration overflow.

commit cdda88912d62f9603d27433338a18be83ef23ac1 upstream.

    I found if we write a larger than 4GB value to some sysctl
variables, the sending syscall will hang up forever, because these
variables are 32 bits, such large values make them overflow to 0 or
negative.

    This patch try to fix overflow or prevent from zero value setup
of below sysctl variables:

net.core.wmem_default
net.core.rmem_default

net.core.rmem_max
net.core.wmem_max

net.ipv4.udp_rmem_min
net.ipv4.udp_wmem_min

net.ipv4.tcp_wmem
net.ipv4.tcp_rmem

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Li Yu <raise.sail@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.2:
 - Adjust context
 - Delete now-unused 'zero' variable]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
(cherry picked from commit 98eee187cdee2807bd80e6c02180c5c2abae6453)
[wt: backported to 2.6.32: set strategy to sysctl_intvec where relevant]
Signed-off-by: Willy Tarreau <w@1wt.eu>

Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
2 files changed