[PATCH]: Can not set the IPV6_PKTINFO option

[Gerrit Renker <gerrit@erg.abdn.ac.uk>]

[IPv6]: Can not set the IPV6_PKTINFO option

The Linux manpage of ipv6(7) mentions the IPV6_PKTINFO option (and it is defined in header
files), but there is no setsockopt support for it. Aliasing to IPV6_RECVPKTINFO fixes this,
and checking datagram_recv_ctl() in net/ipv6/datagram.c confirms that this works as 
expected from the API.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
---
--- a/net/ipv6/ipv6_sockglue.c
+++ b/net/ipv6/ipv6_sockglue.c
@@ -315,6 +315,7 @@ static int do_ipv6_setsockopt(struct sock *sk, int level, int optname,
 		retv = 0;
 		break;
 
+	case IPV6_PKTINFO:
 	case IPV6_RECVPKTINFO:
 		np->rxopt.bits.rxinfo = valbool;
 		retv = 0;
@@ -928,6 +929,7 @@ static int do_ipv6_getsockopt(struct sock *sk, int level, int optname,
 		val = np->ipv6only;
 		break;
 
+	case IPV6_PKTINFO:
 	case IPV6_RECVPKTINFO:
 		val = np->rxopt.bits.rxinfo;
 		break;