[PATCH] RAW6: Do not allow set IPV6_CHECKSUM for ICMPv6 socket

[Wang Chen <wangchen@cn.fujitsu.com>]

As RFC3542 mentions: An attempt to set IPV6_CHECKSUM for an
ICMPv6 socket will fail.
Add a check for that in do_rawv6_setsockopt().

Signed-off-by: Wang Chen <wangchen@cn.fujitsu.com>
---
 net/ipv6/raw.c |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)

diff --git a/net/ipv6/raw.c b/net/ipv6/raw.c
index 0a6fbc1..c4cc1f9 100644
--- a/net/ipv6/raw.c
+++ b/net/ipv6/raw.c
@@ -994,6 +994,11 @@ static int do_rawv6_setsockopt(struct sock *sk, int level, int optname,
 
 	switch (optname) {
 		case IPV6_CHECKSUM:
+			/* RFC3542: An attempt to set IPV6_CHECKSUM for an
+			 * ICMPv6 socket will fail.
+			 */
+			if (inet_sk(sk)->num == IPPROTO_ICMPV6)
+				return(-EINVAL);
 			/* You may get strange result with a positive odd offset;
 			   RFC2292bis agrees with me. */
 			if (val > 0 && (val&1))
-- 
1.5.4