sctp: add stream reconf timer

This patch is to add a per transport timer based on sctp timer frame
for stream reconf chunk retransmission. It would start after sending
a reconf request chunk, and stop after receiving the response chunk.

If the timer expires, besides retransmitting the reconf request chunk,
it would also do the same thing with data RTO timer. like to increase
the appropriate error counts, and perform threshold management, possibly
destroying the asoc if sctp retransmission thresholds are exceeded, just
as section 5.1.1 describes.

This patch is also to add asoc strreset_chunk, it is used to save the
reconf request chunk, so that it can be retransmitted, and to check if
the response is really for this request by comparing the information
inside with the response chunk as well.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 9 insertions, 0 deletions

diff --git a/include/net/sctp/constants.h b/include/net/sctp/constants.h
index 5b847e49f7e9..8307c862b5c2 100644
--- a/include/net/sctp/constants.h
+++ b/include/net/sctp/constants.h
@@ -90,6 +90,7 @@ typedef enum {
 	SCTP_EVENT_TIMEOUT_T4_RTO,
 	SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD,
 	SCTP_EVENT_TIMEOUT_HEARTBEAT,
+	SCTP_EVENT_TIMEOUT_RECONF,
 	SCTP_EVENT_TIMEOUT_SACK,
 	SCTP_EVENT_TIMEOUT_AUTOCLOSE,
 } sctp_event_timeout_t;
diff --git a/include/net/sctp/sm.h b/include/net/sctp/sm.h
index 3462cb08f51a..d2d9e28fe783 100644
--- a/include/net/sctp/sm.h
+++ b/include/net/sctp/sm.h
@@ -167,6 +167,7 @@ sctp_state_fn_t sctp_sf_cookie_wait_icmp_abort;
 
 /* Prototypes for timeout event state functions.  */
 sctp_state_fn_t sctp_sf_do_6_3_3_rtx;
+sctp_state_fn_t sctp_sf_send_reconf;
 sctp_state_fn_t sctp_sf_do_6_2_sack;
 sctp_state_fn_t sctp_sf_autoclose_timer_expire;
 
@@ -278,6 +279,7 @@ int sctp_do_sm(struct net *net, sctp_event_t event_type, sctp_subtype_t subtype,
 /* 2nd level prototypes */
 void sctp_generate_t3_rtx_event(unsigned long peer);
 void sctp_generate_heartbeat_event(unsigned long peer);
+void sctp_generate_reconf_event(unsigned long peer);
 void sctp_generate_proto_unreach_event(unsigned long peer);
 
 void sctp_ootb_pkt_free(struct sctp_packet *);
diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
index 3dc983e97564..463b4d642d68 100644
--- a/include/net/sctp/structs.h
+++ b/include/net/sctp/structs.h
@@ -877,6 +877,9 @@ struct sctp_transport {
 	/* Timer to handle ICMP proto unreachable envets */
 	struct timer_list proto_unreach_timer;
 
+	/* Timer to handler reconf chunk rtx */
+	struct timer_list reconf_timer;
+
 	/* Since we're using per-destination retransmission timers
 	 * (see above), we're also using per-destination "transmitted"
 	 * queues.  This probably ought to be a private struct
@@ -935,6 +938,7 @@ void sctp_transport_pmtu(struct sctp_transport *, struct sock *sk);
 void sctp_transport_free(struct sctp_transport *);
 void sctp_transport_reset_t3_rtx(struct sctp_transport *);
 void sctp_transport_reset_hb_timer(struct sctp_transport *);
+void sctp_transport_reset_reconf_timer(struct sctp_transport *transport);
 int sctp_transport_hold(struct sctp_transport *);
 void sctp_transport_put(struct sctp_transport *);
 void sctp_transport_update_rto(struct sctp_transport *, __u32);
@@ -1868,6 +1872,8 @@ struct sctp_association {
 	__u32 strreset_outseq; /* Update after receiving response */
 	__u32 strreset_inseq; /* Update after receiving request */
 
+	struct sctp_chunk *strreset_chunk; /* save request chunk */
+
 	struct sctp_priv_assoc_stats stats;
 
 	int sent_cnt_removable;