tipc: Add routines for safe checking of node's network address

Introduces routines that test whether a given network address is
equal to a node's own network address or if it lies within the node's
own network cluster, and which work properly regardless of whether
the node is using the default network address <0.0.0> or a non-zero
network address that is assigned later on. In essence, these routines
ensure that address <0.0.0> is treated as an alias for "this node",
regardless of which network address the node is actually using.

Old users of the pre-existing more strict match in_own_cluster()
have been accordingly redirected to what is now called
in_own_cluster_exact() --- which does not extend matching to <0,0,0>.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

1 files changed, 19 insertions, 1 deletions

diff --git a/net/tipc/addr.h b/net/tipc/addr.h
index e4f35afe3207..d706a1d92be8 100644
--- a/net/tipc/addr.h
+++ b/net/tipc/addr.h
@@ -50,12 +50,30 @@ static inline u32 tipc_cluster_mask(u32 addr)
         return addr & TIPC_CLUSTER_MASK;
 }
 
-static inline int in_own_cluster(u32 addr)
+static inline int in_own_cluster_exact(u32 addr)
 {
         return !((addr ^ tipc_own_addr) >> 12);
 }
 
 /**
+ * in_own_node - test for node inclusion; <0.0.0> always matches
+ */
+
+static inline int in_own_node(u32 addr)
+{
+        return (addr == tipc_own_addr) || !addr;
+}
+
+/**
+ * in_own_cluster - test for cluster inclusion; <0.0.0> always matches
+ */
+
+static inline int in_own_cluster(u32 addr)
+{
+        return in_own_cluster_exact(addr) || !addr;
+}
+
+/**
  * addr_domain - convert 2-bit scope value to equivalent message lookup domain
  *
  * Needed when address of a named message must be looked up a second time