net: Handle different key sizes between address families in flow cache

With the conversion of struct flowi to a union of AF-specific structs, some
operations on the flow cache need to account for the exact size of the key.

Signed-off-by: David Ward <david.ward@ll.mit.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 19 insertions, 0 deletions

diff --git a/include/net/flow.h b/include/net/flow.h
index 2ec377d9ab9f..a09447749e2d 100644
--- a/include/net/flow.h
+++ b/include/net/flow.h
@@ -7,6 +7,7 @@
 #ifndef _NET_FLOW_H
 #define _NET_FLOW_H
 
+#include <linux/socket.h>
 #include <linux/in6.h>
 #include <linux/atomic.h>
 
@@ -161,6 +162,24 @@ static inline struct flowi *flowidn_to_flowi(struct flowidn *fldn)
         return container_of(fldn, struct flowi, u.dn);
 }
 
+typedef unsigned long flow_compare_t;
+
+static inline size_t flow_key_size(u16 family)
+{
+        switch (family) {
+        case AF_INET:
+                BUILD_BUG_ON(sizeof(struct flowi4) % sizeof(flow_compare_t));
+                return sizeof(struct flowi4) / sizeof(flow_compare_t);
+        case AF_INET6:
+                BUILD_BUG_ON(sizeof(struct flowi6) % sizeof(flow_compare_t));
+                return sizeof(struct flowi6) / sizeof(flow_compare_t);
+        case AF_DECnet:
+                BUILD_BUG_ON(sizeof(struct flowidn) % sizeof(flow_compare_t));
+                return sizeof(struct flowidn) / sizeof(flow_compare_t);
+        }
+        return 0;
+}
+
 #define FLOW_DIR_IN     0
 #define FLOW_DIR_OUT    1
 #define FLOW_DIR_FWD    2