linux/net
Pavel Emelyanov b139ba4e90 tcp: Repair connection-time negotiated parameters
There are options, which are set up on a socket while performing
TCP handshake. Need to resurrect them on a socket while repairing.
A new sockoption accepts a buffer and parses it. The buffer should
be CODE:VALUE sequence of bytes, where CODE is standard option
code and VALUE is the respective value.

Only 4 options should be handled on repaired socket.

To read 3 out of 4 of these options the TCP_INFO sockoption can be
used. An ability to get the last one (the mss_clamp) was added by
the previous patch.

Now the restore. Three of these options -- timestamp_ok, mss_clamp
and snd_wscale -- are just restored on a coket.

The sack_ok flags has 2 issues. First, whether or not to do sacks
at all. This flag is just read and set back. No other sack  info is
saved or restored, since according to the standart and the code
dropping all sack-ed segments is OK, the sender will resubmit them
again, so after the repair we will probably experience a pause in
connection. Next, the fack bit. It's just set back on a socket if
the respective sysctl is set. No collected stats about packets flow
is preserved. As far as I see (plz, correct me if I'm wrong) the
fack-based congestion algorithm survives dropping all of the stats
and repairs itself eventually, probably losing the performance for
that period.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-21 15:52:25 -04:00
..
9p net: cleanup unsigned to unsigned int 2012-04-15 12:44:40 -04:00
802 net: Convert all sysctl registrations to register_net_sysctl 2012-04-20 21:22:30 -04:00
8021q vlan: Stop using NLA_PUT*(). 2012-04-02 04:33:44 -04:00
appletalk net: Convert all sysctl registrations to register_net_sysctl 2012-04-20 21:22:30 -04:00
atm net: cleanup unsigned to unsigned int 2012-04-15 12:44:40 -04:00
ax25 net ax25: Simplify and cleanup the ax25 sysctl handling. 2012-04-20 21:22:28 -04:00
batman-adv batman-adv: skip the window protection test when the originator has no neighbours 2012-04-18 09:54:02 +02:00
bluetooth Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth 2012-04-09 15:47:49 -04:00
bridge net: Convert all sysctl registrations to register_net_sysctl 2012-04-20 21:22:30 -04:00
caif net: cleanup unsigned to unsigned int 2012-04-15 12:44:40 -04:00
can can: fix sparse warning for cgw_list 2012-04-16 21:08:18 +02:00
ceph net: cleanup unsigned to unsigned int 2012-04-15 12:44:40 -04:00
core sock: Introduce named constants for sk_reuse 2012-04-21 15:52:25 -04:00
dcb net/dcb: Add an optional max rate attribute 2012-04-05 05:08:04 -04:00
dccp net: Convert all sysctl registrations to register_net_sysctl 2012-04-20 21:22:30 -04:00
decnet net decnet: Convert to use register_net_sysctl 2012-04-20 21:22:29 -04:00
dns_resolver net: cleanup unsigned to unsigned int 2012-04-15 12:44:40 -04:00
dsa dsa: Move switch drivers to new directory drivers/net/dsa 2011-11-29 00:21:36 -05:00
econet sock: Introduce named constants for sk_reuse 2012-04-21 15:52:25 -04:00
ethernet net: cleanup unsigned to unsigned int 2012-04-15 12:44:40 -04:00
ieee802154 net: cleanup unsigned to unsigned int 2012-04-15 12:44:40 -04:00
ipv4 tcp: Repair connection-time negotiated parameters 2012-04-21 15:52:25 -04:00
ipv6 sock: Introduce named constants for sk_reuse 2012-04-21 15:52:25 -04:00
ipx net: Convert all sysctl registrations to register_net_sysctl 2012-04-20 21:22:30 -04:00
irda net: Convert all sysctl registrations to register_net_sysctl 2012-04-20 21:22:30 -04:00
iucv Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 2012-03-22 18:15:32 -07:00
key net: cleanup unsigned to unsigned int 2012-04-15 12:44:40 -04:00
l2tp net: cleanup unsigned to unsigned int 2012-04-15 12:44:40 -04:00
lapb Remove all #inclusions of asm/system.h 2012-03-28 18:30:03 +01:00
llc net llc: Don't use sysctl tables with .child entries. 2012-04-20 21:22:29 -04:00
mac80211 mac80211: add function retrieve average rssi 2012-04-16 14:38:49 -04:00
netfilter sock: Introduce named constants for sk_reuse 2012-04-21 15:52:25 -04:00
netlabel netlabel: use GFP flags from caller instead of GFP_ATOMIC 2012-03-22 19:29:57 -04:00
netlink netlink: dont drop packet but consume it 2012-04-19 14:23:55 -04:00
netrom net: Convert all sysctl registrations to register_net_sysctl 2012-04-20 21:22:30 -04:00
nfc Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next into for-davem 2012-04-18 14:27:48 -04:00
openvswitch net: cleanup unsigned to unsigned int 2012-04-15 12:44:40 -04:00
packet packet: dont drop packet but consume it 2012-04-19 14:23:55 -04:00
phonet net: Convert all sysctl registrations to register_net_sysctl 2012-04-20 21:22:30 -04:00
rds sock: Introduce named constants for sk_reuse 2012-04-21 15:52:25 -04:00
rfkill device.h: cleanup users outside of linux/include (C files) 2012-03-11 14:27:37 -04:00
rose net: Convert all sysctl registrations to register_net_sysctl 2012-04-20 21:22:30 -04:00
rxrpc net: cleanup unsigned to unsigned int 2012-04-15 12:44:40 -04:00
sched pkt_sched: Stop using NLA_PUT*(). 2012-04-01 18:11:37 -04:00
sctp net: Convert all sysctl registrations to register_net_sysctl 2012-04-20 21:22:30 -04:00
sunrpc sock: Introduce named constants for sk_reuse 2012-04-21 15:52:25 -04:00
tipc tipc: Ensure network address change doesn't impact configuration service 2012-04-19 15:46:50 -04:00
unix net: Convert all sysctl registrations to register_net_sysctl 2012-04-20 21:22:30 -04:00
wanrouter wanrouter: Remove kernel_lock annotations 2011-11-07 13:27:30 -05:00
wimax net: cleanup unsigned to unsigned int 2012-04-15 12:44:40 -04:00
wireless Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next into for-davem 2012-04-18 14:27:48 -04:00
x25 net: Convert all sysctl registrations to register_net_sysctl 2012-04-20 21:22:30 -04:00
xfrm net: Convert all sysctl registrations to register_net_sysctl 2012-04-20 21:22:30 -04:00
compat.c net: cleanup unsigned to unsigned int 2012-04-15 12:44:40 -04:00
Kconfig net: Add Open vSwitch kernel components. 2011-12-03 09:35:17 -08:00
Makefile net: Add Open vSwitch kernel components. 2011-12-03 09:35:17 -08:00
nonet.c
socket.c net sysctl: Initialize the network sysctls sooner to avoid problems. 2012-04-20 21:21:16 -04:00
sysctl_net.c net: Remove register_net_sysctl_table 2012-04-20 21:22:30 -04:00