ipv6: routing header fixes

This patch fixes two bugs:

1. setsockopt() of anything but a Type 2 routing header should return
EINVAL instead of EPERM.  Noticed by Shan Wei
(shanwei@cn.fujitsu.com).

2. setsockopt()/sendmsg() of a Type 2 routing header with invalid
length or segments should return EINVAL.  These values are statically
fixed in RFC 3775, unlike the variable Type 0 was.

Signed-off-by: Brian Haley <brian.haley@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c
index 4e5eac3..2aa294b 100644
--- a/net/ipv6/ipv6_sockglue.c
+++ b/net/ipv6/ipv6_sockglue.c
@@ -366,11 +366,16 @@
 		}
 
 		/* routing header option needs extra check */
+		retv = -EINVAL;
 		if (optname == IPV6_RTHDR && opt && opt->srcrt) {
 			struct ipv6_rt_hdr *rthdr = opt->srcrt;
 			switch (rthdr->type) {
 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
 			case IPV6_SRCRT_TYPE_2:
+				if (rthdr->hdrlen != 2 ||
+				    rthdr->segments_left != 1)
+					goto sticky_done;
+
 				break;
 #endif
 			default: