selinux: cleanup selinux_xfrm_sock_rcv_skb() and selinux_xfrm_postroute_last()

Some basic simplification and comment reformatting.

Signed-off-by: Paul Moore <pmoore@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>

2 files changed, 42 insertions, 60 deletions

diff --git a/security/selinux/include/xfrm.h b/security/selinux/include/xfrm.h
index f2a2314aac1a..b463f210f1af 100644
--- a/security/selinux/include/xfrm.h
+++ b/security/selinux/include/xfrm.h
@@ -44,10 +44,10 @@ static inline int selinux_xfrm_enabled(void)
         return (atomic_read(&selinux_xfrm_refcount) > 0);
 }
 
-int selinux_xfrm_sock_rcv_skb(u32 sid, struct sk_buff *skb,
-                        struct common_audit_data *ad);
-int selinux_xfrm_postroute_last(u32 isec_sid, struct sk_buff *skb,
-                        struct common_audit_data *ad, u8 proto);
+int selinux_xfrm_sock_rcv_skb(u32 sk_sid, struct sk_buff *skb,
+                              struct common_audit_data *ad);
+int selinux_xfrm_postroute_last(u32 sk_sid, struct sk_buff *skb,
+                                struct common_audit_data *ad, u8 proto);
 int selinux_xfrm_decode_session(struct sk_buff *skb, u32 *sid, int ckall);
 
 static inline void selinux_xfrm_notify_policyload(void)
@@ -61,14 +61,15 @@ static inline int selinux_xfrm_enabled(void)
         return 0;
 }
 
-static inline int selinux_xfrm_sock_rcv_skb(u32 isec_sid, struct sk_buff *skb,
-                        struct common_audit_data *ad)
+static inline int selinux_xfrm_sock_rcv_skb(u32 sk_sid, struct sk_buff *skb,
+                                            struct common_audit_data *ad)
 {
         return 0;
 }
 
-static inline int selinux_xfrm_postroute_last(u32 isec_sid, struct sk_buff *skb,
-                        struct common_audit_data *ad, u8 proto)
+static inline int selinux_xfrm_postroute_last(u32 sk_sid, struct sk_buff *skb,
+                                              struct common_audit_data *ad,
+                                              u8 proto)
 {
         return 0;
 }
diff --git a/security/selinux/xfrm.c b/security/selinux/xfrm.c
index 4a7ba4ac487e..1f6c6e619e98 100644
--- a/security/selinux/xfrm.c
+++ b/security/selinux/xfrm.c
@@ -367,14 +367,12 @@ int selinux_xfrm_state_delete(struct xfrm_state *x)
  * we need to check for unlabelled access since this may not have
  * gone thru the IPSec process.
  */
-int selinux_xfrm_sock_rcv_skb(u32 isec_sid, struct sk_buff *skb,
-                                struct common_audit_data *ad)
+int selinux_xfrm_sock_rcv_skb(u32 sk_sid, struct sk_buff *skb,
+                              struct common_audit_data *ad)
 {
-        int i, rc = 0;
-        struct sec_path *sp;
-        u32 sel_sid = SECINITSID_UNLABELED;
-
-        sp = skb->sp;
+        int i;
+        struct sec_path *sp = skb->sp;
+        u32 peer_sid = SECINITSID_UNLABELED;
 
         if (sp) {
                 for (i = 0; i < sp->len; i++) {
@@ -382,23 +380,17 @@ int selinux_xfrm_sock_rcv_skb(u32 isec_sid, struct sk_buff *skb,
 
                         if (x && selinux_authorizable_xfrm(x)) {
                                 struct xfrm_sec_ctx *ctx = x->security;
-                                sel_sid = ctx->ctx_sid;
+                                peer_sid = ctx->ctx_sid;
                                 break;
                         }
                 }
         }
 
-        /*
-         * This check even when there's no association involved is
-         * intended, according to Trent Jaeger, to make sure a
-         * process can't engage in non-ipsec communication unless
-         * explicitly allowed by policy.
-         */
-
-        rc = avc_has_perm(isec_sid, sel_sid, SECCLASS_ASSOCIATION,
-                          ASSOCIATION__RECVFROM, ad);
-
-        return rc;
+        /* This check even when there's no association involved is intended,
+         * according to Trent Jaeger, to make sure a process can't engage in
+         * non-IPsec communication unless explicitly allowed by policy. */
+        return avc_has_perm(sk_sid, peer_sid,
+                            SECCLASS_ASSOCIATION, ASSOCIATION__RECVFROM, ad);
 }
 
 /*
@@ -408,49 +400,38 @@ int selinux_xfrm_sock_rcv_skb(u32 isec_sid, struct sk_buff *skb,
  * If we do have a authorizable security association, then it has already been
  * checked in the selinux_xfrm_state_pol_flow_match hook above.
  */
-int selinux_xfrm_postroute_last(u32 isec_sid, struct sk_buff *skb,
-                                        struct common_audit_data *ad, u8 proto)
+int selinux_xfrm_postroute_last(u32 sk_sid, struct sk_buff *skb,
+                                struct common_audit_data *ad, u8 proto)
 {
         struct dst_entry *dst;
-        int rc = 0;
-
-        dst = skb_dst(skb);
-
-        if (dst) {
-                struct dst_entry *dst_test;
-
-                for (dst_test = dst; dst_test != NULL;
-                     dst_test = dst_test->child) {
-                        struct xfrm_state *x = dst_test->xfrm;
-
-                        if (x && selinux_authorizable_xfrm(x))
-                                goto out;
-                }
-        }
 
         switch (proto) {
         case IPPROTO_AH:
         case IPPROTO_ESP:
         case IPPROTO_COMP:
-                /*
-                 * We should have already seen this packet once before
-                 * it underwent xfrm(s). No need to subject it to the
-                 * unlabeled check.
-                 */
-                goto out;
+                /* We should have already seen this packet once before it
+                 * underwent xfrm(s). No need to subject it to the unlabeled
+                 * check. */
+                return 0;
         default:
                 break;
         }
 
-        /*
-         * This check even when there's no association involved is
-         * intended, according to Trent Jaeger, to make sure a
-         * process can't engage in non-ipsec communication unless
-         * explicitly allowed by policy.
-         */
+        dst = skb_dst(skb);
+        if (dst) {
+                struct dst_entry *iter;
 
-        rc = avc_has_perm(isec_sid, SECINITSID_UNLABELED, SECCLASS_ASSOCIATION,
-                          ASSOCIATION__SENDTO, ad);
-out:
-        return rc;
+                for (iter = dst; iter != NULL; iter = iter->child) {
+                        struct xfrm_state *x = iter->xfrm;
+
+                        if (x && selinux_authorizable_xfrm(x))
+                                return 0;
+                }
+        }
+
+        /* This check even when there's no association involved is intended,
+         * according to Trent Jaeger, to make sure a process can't engage in
+         * non-IPsec communication unless explicitly allowed by policy. */
+        return avc_has_perm(sk_sid, SECINITSID_UNLABELED,
+                            SECCLASS_ASSOCIATION, ASSOCIATION__SENDTO, ad);
 }