[DCCP]: Add Support for Data 1 .. 3 fields of Reset packets

This adds fields to support the informational Data 1..3 fields of the
DCCP-Reset packets (RFC 4340, 5.6), and makes minor cosmetic changes
to documentation.
Code which fills in these fields follows in subsequent patches, it is
primarily used for reporting option-processing and feature-negotiation
errors.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>

1 files changed, 13 insertions, 1 deletions

diff --git a/net/dccp/dccp.h b/net/dccp/dccp.h
index f62eeb374931..e28220183208 100644
--- a/net/dccp/dccp.h
+++ b/net/dccp/dccp.h
@@ -308,10 +308,22 @@ static inline int dccp_bad_service_code(const struct sock *sk,
         return !dccp_list_has_service(dp->dccps_service_list, service);
 }
 
+/**
+ * dccp_skb_cb  -  DCCP per-packet control information
+ * @dccpd_type: one of %dccp_pkt_type (or unknown)
+ * @dccpd_ccval: CCVal field (5.1), see e.g. RFC 4342, 8.1
+ * @dccpd_reset_code: one of %dccp_reset_codes
+ * @dccpd_reset_data: Data1..3 fields (depend on @dccpd_reset_code)
+ * @dccpd_opt_len: total length of all options (5.8) in the packet
+ * @dccpd_seq: sequence number
+ * @dccpd_ack_seq: acknowledgment number subheader field value
+ * This is used for transmission as well as for reception.
+ */
 struct dccp_skb_cb {
         __u8  dccpd_type:4;
         __u8  dccpd_ccval:4;
-        __u8  dccpd_reset_code;
+        __u8  dccpd_reset_code,
+              dccpd_reset_data[3];
         __u16 dccpd_opt_len;
         __u64 dccpd_seq;
         __u64 dccpd_ack_seq;