[PATCH 25/25]: Add test function for data packets

[Gerrit Renker <gerrit@erg.abdn.ac.uk>]

[DCCP]: Add test function for data packets

This adds a function which returns `true' when an skb contains one of the packet
types specified in [RFC 4340, 7.7] as `data packet'. 

NB - Resisted the temptation to define 
     int dccp_non_data_packet(skb) { return !dccp_data_packet(skb); },
     since maybe someone will define new packet types.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
---
 net/dccp/dccp.h |   12 ++++++++++++
 1 file changed, 12 insertions(+)

--- a/net/dccp/dccp.h
+++ b/net/dccp/dccp.h
@@ -321,6 +321,7 @@ struct dccp_skb_cb {
 
 #define DCCP_SKB_CB(__skb) ((struct dccp_skb_cb *)&((__skb)->cb[0]))
 
+/* RFC 4340, sec. 7.7 */
 static inline int dccp_non_data_packet(const struct sk_buff *skb)
 {
 	const __u8 type = DCCP_SKB_CB(skb)->dccpd_type;
@@ -333,6 +334,17 @@ static inline int dccp_non_data_packet(c
 	       type = DCCP_PKT_SYNCACK;
 }
 
+/* RFC 4340, sec. 7.7 */
+static inline int dccp_data_packet(const struct sk_buff *skb)
+{
+	const __u8 type = DCCP_SKB_CB(skb)->dccpd_type;
+
+	return type = DCCP_PKT_DATA	 ||
+	       type = DCCP_PKT_DATAACK  ||
+	       type = DCCP_PKT_REQUEST  ||
+	       type = DCCP_PKT_RESPONSE;
+}
+
 static inline int dccp_packet_without_ack(const struct sk_buff *skb)
 {
 	const __u8 type = DCCP_SKB_CB(skb)->dccpd_type;