[PATCH 2.4] IP: disable ECN support by default - Config option

[PATCH 2.4] IP: disable ECN support by default - Config option

[Marc-Christian Petersen]

[-- Attachment #1: Type: text/plain, Size: 243 bytes --]

Hi Marcelo,

attached super trivial patch gives us a config option to choose whether we 
want ECN disabled per default if selected or not.

consider for inclusion into 2.4.

Has been in WOLK and in Debian kernels for ages.

ciao, Marc

[-- Attachment #2: ecn-disable-per-default-config-option.patch --]
[-- Type: text/x-diff, Size: 847 bytes --]

--- linux-old/net/ipv4/Config.in
+++ linux-wolk/net/ipv4/Config.in
@@ -40,6 +40,9 @@
    bool '  IP: ARP daemon support (EXPERIMENTAL)' CONFIG_ARPD
 fi
 bool '  IP: TCP Explicit Congestion Notification support' CONFIG_INET_ECN
+if [ "$CONFIG_INET_ECN" = "y" ]; then
+   bool '    IP: disable ECN support by default' CONFIG_INET_ECN_DISABLED
+fi
 bool '  IP: TCP syncookie support (disabled per default)' CONFIG_SYN_COOKIES
 if [ "$CONFIG_NETFILTER" != "n" ]; then
    source net/ipv4/netfilter/Config.in
--- linux-old/net/ipv4/tcp_input.c
+++ linux-wolk/net/ipv4/tcp_input.c
@@ -74,7 +74,7 @@
 int sysctl_tcp_sack = 1;
 int sysctl_tcp_fack = 1;
 int sysctl_tcp_reordering = TCP_FASTRETRANS_THRESH;
-#ifdef CONFIG_INET_ECN
+#if defined(CONFIG_INET_ECN) && !defined(CONFIG_INET_ECN_DISABLED)
 int sysctl_tcp_ecn = 1;
 #else
 int sysctl_tcp_ecn = 0;

Re: [PATCH 2.4] IP: disable ECN support by default - Config option

[Krzysztof Halasa]

Marc-Christian Petersen <m.c.p@wolk-project.de> writes:

> attached super trivial patch gives us a config option to choose whether we 
> want ECN disabled per default if selected or not.

Why do we need that if we can enable/disable ECN at runtime?
-- 
Krzysztof Halasa
Network Administrator

Re: [PATCH 2.4] IP: disable ECN support by default - Config option

[David S. Miller]

CONFIG_INET_ECN does exactly what you want.

If you turn it on, ECN is on by default.
If you turn it off, ECN is off by default.

The ECN support itself, is always compiled into the
kernel.  CONFIG_INET_ECN only determines the initial
setting of the ecn sysctl.

Your patch adds zero functionality and only serves to make
the cofiguration more complicated.

Re: [PATCH 2.4] IP: disable ECN support by default - Config option

[Marc-Christian Petersen]

On Tuesday 10 December 2002 04:28, David S. Miller wrote:

Hi David,

> CONFIG_INET_ECN does exactly what you want.
>
> If you turn it on, ECN is on by default.
> If you turn it off, ECN is off by default.

args, you are right. Sorry, my mistake! Maybe I need some sleep, looking twice 
it is sooo obvious :)

ciao, Marc