[PATCH] Set TOS (TCLASS) bits under ipv6

[Dave Taht]

Setting the TCLASS (TOS) field requires different setsockopt
params on ipv6 than ipv4.

as per:

http://www.bufferbloat.net/projects/cerowrt/issues/249
---
 dbutil.c |    6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/dbutil.c b/dbutil.c
index b3a119f..2739d2f 100644
--- a/dbutil.c
+++ b/dbutil.c
@@ -161,10 +161,12 @@ static void set_sock_priority(int sock) {
 	val = 1;
 	setsockopt(sock, IPPROTO_TCP, TCP_NODELAY, (void*)&val, sizeof(val));

-	/* set the TOS bit. note that this will fail for ipv6, I can't find any
-	 * equivalent. */
+	/* bruteforce the TOS bit for ipv4 or ipv6. Note that for versions of
+           Linux prior to 2.6.39 this will stomp on the ECN bit under IPv6 */
+
 #ifdef IPTOS_LOWDELAY
 	val = IPTOS_LOWDELAY;
+	setsockopt(sock, IPPROTO_IPV6, IPV6_TCLASS, (void*)&val, sizeof(val));
 	setsockopt(sock, IPPROTO_IP, IP_TOS, (void*)&val, sizeof(val));
 #endif

-- 
1.7.4.1


--
Dave Täht
SKYPE: davetaht
US Tel: 1-239-829-5608
http://the-edge.blogspot.com