[MLSXFRM]: Add flow labeling

This labels the flows that could utilize IPSec xfrms at the points the
flows are defined so that IPSec policy and SAs at the right label can
be used.

The following protos are currently not handled, but they should
continue to be able to use single-labeled IPSec like they currently
do.

ipmr
ip_gre
ipip
igmp
sit
sctp
ip6_tunnel (IPv6 over IPv6 tunnel device)
decnet

Signed-off-by: Venkat Yekkirala <vyekkirala@TrustedCS.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 7 insertions, 4 deletions

diff --git a/security/selinux/xfrm.c b/security/selinux/xfrm.c
index a502b0540e3d..c750ef7af66f 100644
--- a/security/selinux/xfrm.c
+++ b/security/selinux/xfrm.c
@@ -158,11 +158,11 @@ int selinux_xfrm_flow_state_match(struct flowi *fl, struct xfrm_state *xfrm)
  * LSM hook implementation that determines the sid for the session.
  */
 
-int selinux_xfrm_decode_session(struct sk_buff *skb, struct flowi *fl)
+int selinux_xfrm_decode_session(struct sk_buff *skb, u32 *sid, int ckall)
 {
         struct sec_path *sp;
 
-        fl->secid = SECSID_NULL;
+        *sid = SECSID_NULL;
 
         if (skb == NULL)
                 return 0;
@@ -177,10 +177,13 @@ int selinux_xfrm_decode_session(struct sk_buff *skb, struct flowi *fl)
                                 struct xfrm_sec_ctx *ctx = x->security;
 
                                 if (!sid_set) {
-                                        fl->secid = ctx->ctx_sid;
+                                        *sid = ctx->ctx_sid;
                                         sid_set = 1;
+
+                                        if (!ckall)
+                                                break;
                                 }
-                                else if (fl->secid != ctx->ctx_sid)
+                                else if (*sid != ctx->ctx_sid)
                                         return -EINVAL;
                         }
                 }