[CCID3]: Move NULL-protection into function

This moves several instances of testing against NULL into the function which is
used to de-reference the CCID-private data.

Committer note: Made the BUG_ON depend on having CONFIG_IP_DCCP_CCID3_DEBUG, as it
                is too much to have this on production code. Also made sure that
                the macro is used only after checking if sk_state is not LISTEN,
                to make it equivalent to what we had before.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>

1 files changed, 14 insertions, 6 deletions

diff --git a/net/dccp/ccids/ccid3.h b/net/dccp/ccids/ccid3.h
index 7cbf2b1329d9..ae99ec430371 100644
--- a/net/dccp/ccids/ccid3.h
+++ b/net/dccp/ccids/ccid3.h
@@ -117,6 +117,15 @@ struct ccid3_hc_tx_sock {
 	struct ccid3_options_received	ccid3hctx_options_received;
 };
 
+static inline struct ccid3_hc_tx_sock *ccid3_hc_tx_sk(const struct sock *sk)
+{
+    struct ccid3_hc_tx_sock *hctx = ccid_priv(dccp_sk(sk)->dccps_hc_tx_ccid);
+#ifdef CONFIG_IP_DCCP_CCID3_DEBUG
+    BUG_ON(hctx == NULL);
+#endif
+    return hctx;
+}
+
 /* TFRC receiver states */
 enum ccid3_hc_rx_states {
 	TFRC_RSTATE_NO_DATA = 1,
@@ -161,14 +170,13 @@ struct ccid3_hc_rx_sock {
 	u32				ccid3hcrx_elapsed_time;
 };
 
-static inline struct ccid3_hc_tx_sock *ccid3_hc_tx_sk(const struct sock *sk)
-{
-    return ccid_priv(dccp_sk(sk)->dccps_hc_tx_ccid);
-}
-
 static inline struct ccid3_hc_rx_sock *ccid3_hc_rx_sk(const struct sock *sk)
 {
-    return ccid_priv(dccp_sk(sk)->dccps_hc_rx_ccid);
+    struct ccid3_hc_rx_sock *hcrx = ccid_priv(dccp_sk(sk)->dccps_hc_rx_ccid);
+#ifdef CONFIG_IP_DCCP_CCID3_DEBUG
+    BUG_ON(hcrx == NULL);
+#endif
+    return hcrx;
 }
 
 #endif /* _DCCP_CCID3_H_ */