dccp: Per-socket initialisation of feature negotiation

This provides feature-negotiation initialisation for both DCCP sockets
and DCCP request_sockets, to support feature negotiation during
connection setup.

It also resolves a FIXME regarding the congestion control
initialisation.

Thanks to Wei Yongjun for help with the IPv6 side of this patch.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 4 insertions, 0 deletions

diff --git a/include/linux/dccp.h b/include/linux/dccp.h
index 3978aff197d9..484b8a1fb023 100644
--- a/include/linux/dccp.h
+++ b/include/linux/dccp.h
@@ -412,6 +412,7 @@ extern void dccp_minisock_init(struct dccp_minisock *dmsk);
  * @dreq_iss: initial sequence number sent on the Response (RFC 4340, 7.1)
  * @dreq_isr: initial sequence number received on the Request
  * @dreq_service: service code present on the Request (there is just one)
+ * @dreq_featneg: feature negotiation options for this connection
  * The following two fields are analogous to the ones in dccp_sock:
  * @dreq_timestamp_echo: last received timestamp to echo (13.1)
  * @dreq_timestamp_echo: the time of receiving the last @dreq_timestamp_echo
@@ -421,6 +422,7 @@ struct dccp_request_sock {
         __u64                    dreq_iss;
         __u64                    dreq_isr;
         __be32                   dreq_service;
+        struct list_head         dreq_featneg;
         __u32                    dreq_timestamp_echo;
         __u32                    dreq_timestamp_time;
 };
@@ -498,6 +500,7 @@ struct dccp_ackvec;
  * @dccps_mss_cache - current value of MSS (path MTU minus header sizes)
  * @dccps_rate_last - timestamp for rate-limiting DCCP-Sync (RFC 4340, 7.5.4)
  * @dccps_minisock - associated minisock (accessed via dccp_msk)
+ * @dccps_featneg - tracks feature-negotiation state (mostly during handshake)
  * @dccps_hc_rx_ackvec - rx half connection ack vector
  * @dccps_hc_rx_ccid - CCID used for the receiver (or receiving half-connection)
  * @dccps_hc_tx_ccid - CCID used for the sender (or sending half-connection)
@@ -535,6 +538,7 @@ struct dccp_sock {
         __u64                           dccps_ndp_count:48;
         unsigned long                   dccps_rate_last;
         struct dccp_minisock            dccps_minisock;
+        struct list_head                dccps_featneg;
         struct dccp_ackvec              *dccps_hc_rx_ackvec;
         struct ccid                     *dccps_hc_rx_ccid;
         struct ccid                     *dccps_hc_tx_ccid;