netlabel: use domain based selectors when address based selectors are not available

NetLabel has the ability to selectively assign network security labels
to outbound traffic based on either the LSM's "domain" (different for
each LSM), the network destination, or a combination of both.  Depending
on the type of traffic, local or forwarded, and the type of traffic
selector, domain or address based, different hooks are used to label the
traffic; the goal being minimal overhead.

Unfortunately, there is a bug such that a system using NetLabel domain
based traffic selectors does not correctly label outbound local traffic
that is not assigned to a socket.  The issue is that in these cases
the associated NetLabel hook only looks at the address based selectors
and not the domain based selectors.  This patch corrects this by
checking both the domain and address based selectors so that the correct
labeling is applied, regardless of the configuration type.

In order to acomplish this fix, this patch also simplifies some of the
NetLabel domainhash structures to use a more common outbound traffic
mapping type: struct netlbl_dommap_def.  This simplifies some of the code
in this patch and paves the way for further simplifications in the
future.

Signed-off-by: Paul Moore <pmoore@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 22 insertions, 24 deletions

diff --git a/net/netlabel/netlabel_domainhash.h b/net/netlabel/netlabel_domainhash.h
index 90872c4..b9be0ee 100644
--- a/net/netlabel/netlabel_domainhash.h
+++ b/net/netlabel/netlabel_domainhash.h
@@ -43,37 +43,35 @@
 #define NETLBL_DOMHSH_BITSIZE       7
 
 /* Domain mapping definition structures */
+struct netlbl_domaddr_map {
+	struct list_head list4;
+	struct list_head list6;
+};
+struct netlbl_dommap_def {
+	u32 type;
+	union {
+		struct netlbl_domaddr_map *addrsel;
+		struct cipso_v4_doi *cipso;
+	};
+};
 #define netlbl_domhsh_addr4_entry(iter) \
 	container_of(iter, struct netlbl_domaddr4_map, list)
 struct netlbl_domaddr4_map {
-	u32 type;
-	union {
-		struct cipso_v4_doi *cipsov4;
-	} type_def;
+	struct netlbl_dommap_def def;
 
 	struct netlbl_af4list list;
 };
 #define netlbl_domhsh_addr6_entry(iter) \
 	container_of(iter, struct netlbl_domaddr6_map, list)
 struct netlbl_domaddr6_map {
-	u32 type;
-
-	/* NOTE: no 'type_def' union needed at present since we don't currently
-	 *       support any IPv6 labeling protocols */
+	struct netlbl_dommap_def def;
 
 	struct netlbl_af6list list;
 };
-struct netlbl_domaddr_map {
-	struct list_head list4;
-	struct list_head list6;
-};
+
 struct netlbl_dom_map {
 	char *domain;
-	u32 type;
-	union {
-		struct cipso_v4_doi *cipsov4;
-		struct netlbl_domaddr_map *addrsel;
-	} type_def;
+	struct netlbl_dommap_def def;
 
 	u32 valid;
 	struct list_head list;
@@ -97,16 +95,16 @@ int netlbl_domhsh_remove_af4(const char *domain,
 int netlbl_domhsh_remove(const char *domain, struct netlbl_audit *audit_info);
 int netlbl_domhsh_remove_default(struct netlbl_audit *audit_info);
 struct netlbl_dom_map *netlbl_domhsh_getentry(const char *domain);
-struct netlbl_domaddr4_map *netlbl_domhsh_getentry_af4(const char *domain,
-						       __be32 addr);
+struct netlbl_dommap_def *netlbl_domhsh_getentry_af4(const char *domain,
+						     __be32 addr);
+#if IS_ENABLED(CONFIG_IPV6)
+struct netlbl_dommap_def *netlbl_domhsh_getentry_af6(const char *domain,
+						   const struct in6_addr *addr);
+#endif /* IPv6 */
+
 int netlbl_domhsh_walk(u32 *skip_bkt,
 		     u32 *skip_chain,
 		     int (*callback) (struct netlbl_dom_map *entry, void *arg),
 		     void *cb_arg);
 
-#if IS_ENABLED(CONFIG_IPV6)
-struct netlbl_domaddr6_map *netlbl_domhsh_getentry_af6(const char *domain,
-						  const struct in6_addr *addr);
-#endif /* IPv6 */
-
 #endif