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: NBrian Haley <brian.haley@hp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/ipv6/datagram.c

@@ -661,6 +661,11 @@ int datagram_send_ctl(struct net *net,
 			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) {
+					err = -EINVAL;
+					goto exit_f;
+				}
 				break;
 #endif
 			default:

net/ipv6/ipv6_sockglue.c

@@ -366,11 +366,16 @@ static int do_ipv6_setsockopt(struct sock *sk, int level, int optname,
 		}
 
 		/* 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: