lkml.org 
[lkml]   [2009]   [Jun]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[PATCH] gre: copy ToS/DiffServ bits to outer IP header
When tunneling IP traffic with GRE this patch makes it possible to export the ToS/DiffServ information to the outer IP header.
This is particularly useful in a scenario with ESP/AH where the inner IP header is encrypted but the packet priority/DiffServ information
should still be respected by the transporting routers (for example in an MPLS backbone network).

The feature is disabled by default and can be enabled on a per-interface basis (/proc/sys/net/ipv4/conf/ethX/gre_copy_tos).

Also does this bring Linux back in the game, as JunOS/IOS provide this for quite some time:
http://www.cisco.com/en/US/docs/ios/11_3/feature/guide/greqos.html
http://www.juniper.net/techpubs/software/junos/junos94/swconfig-services/configuring-a-gre-tunnel-to-copy-tos-bits-to-the-outer-ip-header.html

Signed-off-by: Andreas Jaggi <aj@open.ch>

diff -urN vanilla-linux-2.6.29.4/include/linux/sysctl.h gre-copy-tos/include/linux/sysctl.h
--- vanilla-linux-2.6.29.4/include/linux/sysctl.h 2009-05-19 01:52:34.000000000 +0200
+++ gre-copy-tos/include/linux/sysctl.h 2009-06-29 14:23:07.000000000 +0200
@@ -490,6 +490,7 @@
NET_IPV4_CONF_ARP_IGNORE=19,
NET_IPV4_CONF_PROMOTE_SECONDARIES=20,
NET_IPV4_CONF_ARP_ACCEPT=21,
+ NET_IPV4_CONF_GRE_COPY_TOS=22,
__NET_IPV4_CONF_MAX
};

diff -urN vanilla-linux-2.6.29.4/kernel/sysctl_check.c gre-copy-tos/kernel/sysctl_check.c
--- vanilla-linux-2.6.29.4/kernel/sysctl_check.c 2009-05-19 01:52:34.000000000 +0200
+++ gre-copy-tos/kernel/sysctl_check.c 2009-06-29 14:23:07.000000000 +0200
@@ -219,6 +219,7 @@
{ NET_IPV4_CONF_ARP_IGNORE, "arp_ignore" },
{ NET_IPV4_CONF_PROMOTE_SECONDARIES, "promote_secondaries" },
{ NET_IPV4_CONF_ARP_ACCEPT, "arp_accept" },
+ { NET_IPV4_CONF_GRE_COPY_TOS, "gre_copy_tos" },
{}
};

diff -urN vanilla-linux-2.6.29.4/net/ipv4/devinet.c gre-copy-tos/net/ipv4/devinet.c
--- vanilla-linux-2.6.29.4/net/ipv4/devinet.c 2009-05-19 01:52:34.000000000 +0200
+++ gre-copy-tos/net/ipv4/devinet.c 2009-06-29 14:23:07.000000000 +0200
@@ -1439,6 +1439,7 @@
DEVINET_SYSCTL_RW_ENTRY(ARP_ANNOUNCE, "arp_announce"),
DEVINET_SYSCTL_RW_ENTRY(ARP_IGNORE, "arp_ignore"),
DEVINET_SYSCTL_RW_ENTRY(ARP_ACCEPT, "arp_accept"),
+ DEVINET_SYSCTL_RW_ENTRY(GRE_COPY_TOS, "gre_copy_tos"),

DEVINET_SYSCTL_FLUSHING_ENTRY(NOXFRM, "disable_xfrm"),
DEVINET_SYSCTL_FLUSHING_ENTRY(NOPOLICY, "disable_policy"),
diff -urN vanilla-linux-2.6.29.4/net/ipv4/ip_gre.c gre-copy-tos/net/ipv4/ip_gre.c
--- vanilla-linux-2.6.29.4/net/ipv4/ip_gre.c 2009-05-19 01:52:34.000000000 +0200
+++ gre-copy-tos/net/ipv4/ip_gre.c 2009-06-29 14:23:24.000000000 +0200
@@ -610,6 +610,7 @@
struct net_device_stats *stats = &tunnel->dev->stats;
struct iphdr *old_iph = ip_hdr(skb);
struct iphdr *tiph;
+ struct in_device *in_dev;
u8 tos;
__be16 df;
struct rtable *rt; /* Route to the other host */
@@ -677,11 +678,13 @@
}

tos = tiph->tos;
- if (tos&1) {
+ in_dev = in_dev_get(dev);
+ if ((in_dev && IN_DEV_ORCONF(in_dev, GRE_COPY_TOS)) || tos&1) {
if (skb->protocol == htons(ETH_P_IP))
tos = old_iph->tos;
tos &= ~1;
}
+ in_dev_put(in_dev);

{
struct flowi fl = { .oif = tunnel->parms.link,

\
 
 \ /
  Last update: 2009-06-29 15:29    [W:0.038 / U:20.760 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site