dccp: Set per-connection CCIDs via socket options

With this patch, TX/RX CCIDs can now be changed on a per-connection
basis, which overrides the defaults set by the global sysctl variables
for TX/RX CCIDs.

To make full use of this facility, the remaining patches of this patch
set are needed, which track dependencies and activate negotiated
feature values.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 0 deletions

diff --git a/net/dccp/feat.h b/net/dccp/feat.h
index 4d172822df17..093af1610d11 100644
--- a/net/dccp/feat.h
+++ b/net/dccp/feat.h
@@ -22,6 +22,8 @@
 /* Wmin=32 and Wmax=2^46-1 from 7.5.2 */
 #define DCCPF_SEQ_WMIN          32
 #define DCCPF_SEQ_WMAX          0x3FFFFFFFFFFFull
+/* Maximum number of SP values that fit in a single (Confirm) option */
+#define DCCP_FEAT_MAX_SP_VALS   (DCCP_SINGLE_OPT_MAXLEN - 2)
 
 enum dccp_feat_type {
         FEAT_AT_RX   = 1,       /* located at RX side of half-connection  */