ip-xfrm: support 'proto any' with 'sport' and 'dport'

When creating an IPsec SA that sets 'proto any' (IPPROTO_IP) and
specifies 'sport' and 'dport' at the same time in selector, the
following error is issued:

"sport" and "dport" are invalid with proto=ip

However using IPPROTO_IP with ports is completely legal and necessary
when one wants to share the SA on both TCP and UDP. One of the
applications requiring sharing SAs is 3GPP IMS AKA authentication.

See also:

 * https://bugzilla.redhat.com/show_bug.cgi?id=497355Reported-by: Jiří Klimeš <jklimes@redhat.com>
Signed-off-by: Pavel Šimerda <psimerda@redhat.com>

ip/ipxfrm.c

@@ -1344,6 +1344,7 @@ static int xfrm_selector_upspec_parse(struct xfrm_selector *sel,
 		case IPPROTO_UDP:
 		case IPPROTO_SCTP:
 		case IPPROTO_DCCP:
+		case IPPROTO_IP: /* to allow shared SA for different protocols */
 			break;
 		default:
 			fprintf(stderr, "\"sport\" and \"dport\" are invalid with PROTO value \"%s\"\n", strxf_proto(sel->proto));