From: Remi Denis-Courmont <rdenis@simphalempin.com>
Date: Thu, 14 Sep 2006 03:08:07 +0000 (-0700)
Subject: [IPV6]: Accept -1 for IPV6_TCLASS
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=d0ee011f7290b51974e4d058cf4455a5ef91177d;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git

[IPV6]: Accept -1 for IPV6_TCLASS

This patch should add support for -1 as "default" IPv6 traffic class,
as specified in IETF RFC3542 §6.5. Within the kernel, it seems tclass
< 0 is already handled, but setsockopt, getsockopt and recvmsg calls
won't accept it from userland.

Signed-off-by: Remi Denis-Courmont <rdenis@simphalempin.com>
Acked-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/ipv6/datagram.c b/net/ipv6/datagram.c
index 99a6eb23378b..3b55b4c8e2d1 100644
--- a/net/ipv6/datagram.c
+++ b/net/ipv6/datagram.c
@@ -696,7 +696,7 @@ int datagram_send_ctl(struct msghdr *msg, struct flowi *fl,
 			}
 
 			tc = *(int *)CMSG_DATA(cmsg);
-			if (tc < 0 || tc > 0xff)
+			if (tc < -1 || tc > 0xff)
 				goto exit_f;
 
 			err = 0;
diff --git a/net/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c
index 43327264e69c..a5eaaf693abf 100644
--- a/net/ipv6/ipv6_sockglue.c
+++ b/net/ipv6/ipv6_sockglue.c
@@ -362,7 +362,7 @@ static int do_ipv6_setsockopt(struct sock *sk, int level, int optname,
 		break;
 
 	case IPV6_TCLASS:
-		if (val < 0 || val > 0xff)
+		if (val < -1 || val > 0xff)
 			goto e_inval;
 		np->tclass = val;
 		retv = 0;
@@ -947,6 +947,8 @@ static int do_ipv6_getsockopt(struct sock *sk, int level, int optname,
 
 	case IPV6_TCLASS:
 		val = np->tclass;
+		if (val < 0)
+			val = 0;
 		break;
 
 	case IPV6_RECVTCLASS: