[DCCP]: Remove unused and redundant validation functions

This removes two inlines which were both called in a single function only:

 1) dccp_feat_change() is always called with either DCCPO_CHANGE_L or DCCPO_CHANGE_R as argument
    * from dccp_set_socktopt_change() via do_dccp_setsockopt() with DCCP_SOCKOPT_CHANGE_R/L
    * from __dccp_feat_init() via dccp_feat_init() also with DCCP_SOCKOPT_CHANGE_R/L.

    Hence the dccp_feat_is_valid_type() is completely unnecessary and always returns true.

 2) Due to (1), the length test reduces to 'len >= 4', which in turn makes
    dccp_feat_is_valid_length() unnecessary.

Furthermore, the inline function dccp_feat_is_reserved() was unfolded,
since only called in a single place.
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@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/dccp/feat.c

@@ -24,11 +24,7 @@ int dccp_feat_change(struct dccp_minisock *dmsk, u8 type, u8 feature,
 
 	dccp_feat_debug(type, feature, *val);
 
-	if (!dccp_feat_is_valid_type(type)) {
-		DCCP_WARN("option type %d invalid in negotiation\n", type);
-		return 1;
-	}
-	if (!dccp_feat_is_valid_length(type, feature, len)) {
+	if (len > 3) {
 		DCCP_WARN("invalid length %d\n", len);
 		return 1;
 	}
@@ -637,12 +633,12 @@ const char *dccp_feat_name(const u8 feat)
 		[DCCPF_MIN_CSUM_COVER]	= "Min. Csum Coverage",
 		[DCCPF_DATA_CHECKSUM]	= "Send Data Checksum",
 	};
+	if (feat > DCCPF_DATA_CHECKSUM && feat < DCCPF_MIN_CCID_SPECIFIC)
+		return feature_names[DCCPF_RESERVED];
+
 	if (feat >= DCCPF_MIN_CCID_SPECIFIC)
 		return "CCID-specific";
 
-	if (dccp_feat_is_reserved(feat))
-		return feature_names[DCCPF_RESERVED];
-
 	return feature_names[feat];
 }
 

net/dccp/feat.h

@@ -14,32 +14,6 @@
 #include <linux/types.h>
 #include "dccp.h"
 
-static inline int dccp_feat_is_valid_length(u8 type, u8 feature, u8 len)
-{
-	/* sec. 6.1: Confirm has at least length 3,
-	 * sec. 6.2: Change  has at least length 4 */
-	if (len < 3)
-		return 1;
-	if (len < 4  && (type == DCCPO_CHANGE_L || type == DCCPO_CHANGE_R))
-		return 1;
-	/* XXX: add per-feature length validation (sec. 6.6.8) */
-	return 0;
-}
-
-static inline int dccp_feat_is_reserved(const u8 feat)
-{
-	return (feat > DCCPF_DATA_CHECKSUM &&
-		feat < DCCPF_MIN_CCID_SPECIFIC) ||
-		feat == DCCPF_RESERVED;
-}
-
-/* feature negotiation knows only these four option types (RFC 4340, sec. 6) */
-static inline int dccp_feat_is_valid_type(const u8 optnum)
-{
-	return optnum >= DCCPO_CHANGE_L && optnum <= DCCPO_CONFIRM_R;
-
-}
-
 #ifdef CONFIG_IP_DCCP_DEBUG
 extern const char *dccp_feat_typename(const u8 type);
 extern const char *dccp_feat_name(const u8 feat);