1 files changed, 48 insertions, 7 deletions

diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index ad2a5cb..d125a26 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -988,6 +988,23 @@ error:
 }
 EXPORT_SYMBOL(xfrm_lookup);
 
+static inline int
+xfrm_secpath_reject(int idx, struct sk_buff *skb, struct flowi *fl)
+{
+	struct xfrm_state *x;
+	int err;
+
+	if (!skb->sp || idx < 0 || idx >= skb->sp->len)
+		return 0;
+	x = skb->sp->xvec[idx];
+	if (!x->type->reject)
+		return 0;
+	xfrm_state_hold(x);
+	err = x->type->reject(x, skb, fl);
+	xfrm_state_put(x);
+	return err;
+}
+
 /* When skb is transformed back to its "native" form, we have to
  * check policy restrictions. At the moment we make this in maximally
  * stupid way. Shame on me. :-) Of course, connected sockets must
@@ -1010,6 +1027,13 @@ xfrm_state_ok(struct xfrm_tmpl *tmpl, struct xfrm_state *x,
 		  xfrm_state_addr_cmp(tmpl, x, family));
 }
 
+/*
+ * 0 or more than 0 is returned when validation is succeeded (either bypass
+ * because of optional transport mode, or next index of the mathced secpath
+ * state with the template.
+ * -1 is returned when no matching template is found.
+ * Otherwise "-2 - errored_index" is returned.
+ */
 static inline int
 xfrm_policy_ok(struct xfrm_tmpl *tmpl, struct sec_path *sp, int start,
 	       unsigned short family)
@@ -1024,8 +1048,11 @@ xfrm_policy_ok(struct xfrm_tmpl *tmpl, struct sec_path *sp, int start,
 	for (; idx < sp->len; idx++) {
 		if (xfrm_state_ok(tmpl, sp->xvec[idx], family))
 			return ++idx;
-		if (sp->xvec[idx]->props.mode != XFRM_MODE_TRANSPORT)
+		if (sp->xvec[idx]->props.mode != XFRM_MODE_TRANSPORT) {
+			if (start == -1)
+				start = -2-idx;
 			break;
+		}
 	}
 	return start;
 }
@@ -1046,11 +1073,14 @@ xfrm_decode_session(struct sk_buff *skb, struct flowi *fl, unsigned short family
 }
 EXPORT_SYMBOL(xfrm_decode_session);
 
-static inline int secpath_has_nontransport(struct sec_path *sp, int k)
+static inline int secpath_has_nontransport(struct sec_path *sp, int k, int *idxp)
 {
 	for (; k < sp->len; k++) {
-		if (sp->xvec[k]->props.mode != XFRM_MODE_TRANSPORT)
+		if (sp->xvec[k]->props.mode != XFRM_MODE_TRANSPORT) {
+			if (idxp)
+				*idxp = k;
 			return 1;
+		}
 	}
 
 	return 0;
@@ -1062,6 +1092,8 @@ int __xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb,
 	struct xfrm_policy *pol;
 	struct flowi fl;
 	u8 fl_dir = policy_to_flow_dir(dir);
+	int xerr_idx = -1;
+	int *xerr_idxp = &xerr_idx;
 
 	if (xfrm_decode_session(skb, &fl, family) < 0)
 		return 0;
@@ -1086,8 +1118,13 @@ int __xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb,
 		pol = flow_cache_lookup(&fl, family, fl_dir,
 					xfrm_policy_lookup);
 
-	if (!pol)
-		return !skb->sp || !secpath_has_nontransport(skb->sp, 0);
+	if (!pol) {
+		if (skb->sp && secpath_has_nontransport(skb->sp, 0, xerr_idxp)) {
+			xfrm_secpath_reject(xerr_idx, skb, &fl);
+			return 0;
+		}
+		return 1;
+	}
 
 	pol->curlft.use_time = (unsigned long)xtime.tv_sec;
 
@@ -1107,11 +1144,14 @@ int __xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb,
 		 */
 		for (i = pol->xfrm_nr-1, k = 0; i >= 0; i--) {
 			k = xfrm_policy_ok(pol->xfrm_vec+i, sp, k, family);
-			if (k < 0)
+			if (k < 0) {
+				if (k < -1 && xerr_idxp)
+					*xerr_idxp = -(2+k);
 				goto reject;
+			}
 		}
 
-		if (secpath_has_nontransport(sp, k))
+		if (secpath_has_nontransport(sp, k, xerr_idxp))
 			goto reject;
 
 		xfrm_pol_put(pol);
@@ -1119,6 +1159,7 @@ int __xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb,
 	}
 
 reject:
+	xfrm_secpath_reject(xerr_idx, skb, &fl);
 	xfrm_pol_put(pol);
 	return 0;
 }