dccp ccid-3: Simplified handling of TX states

Since CCIDs are only used during the established phase of a connection,
they have very little internal state; this specifically reduces to:

 * "no packet sent" if and only if s == 0, for the TX packet size s;

 * when the first packet has been sent (i.e. `s' > 0), the question is whether
   or not feedback has been received:
   - if a feedback packet is received, "feedback = yes" is set,
   - if the nofeedback timer expires,  "feedback = no"  is set.

Thus the CCID only needs to remember state about whether or not feedback
has been received. This is now implemented using a boolean flag, which is
toggled when a feedback packet arrives or the nofeedback timer expires.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>

1 files changed, 2 insertions, 9 deletions

diff --git a/net/dccp/ccids/ccid3.h b/net/dccp/ccids/ccid3.h
index 7884159937a..1773a8dd36d 100644
--- a/net/dccp/ccids/ccid3.h
+++ b/net/dccp/ccids/ccid3.h
@@ -70,13 +70,6 @@ enum ccid3_options {
 	TFRC_OPT_RECEIVE_RATE	 = 194,
 };
 
-/* TFRC sender states */
-enum ccid3_hc_tx_states {
-	TFRC_SSTATE_NO_SENT = 1,
-	TFRC_SSTATE_NO_FBACK,
-	TFRC_SSTATE_FBACK,
-};
-
 /** struct ccid3_hc_tx_sock - CCID3 sender half-connection socket
  *
  * @x - Current sending rate in 64 * bytes per second
@@ -87,7 +80,7 @@ enum ccid3_hc_tx_states {
  * @s - Packet size in bytes
  * @t_rto - Nofeedback Timer setting in usecs
  * @t_ipi - Interpacket (send) interval (RFC 3448, 4.6) in usecs
- * @state - Sender state, one of %ccid3_hc_tx_states
+ * @feedback - Whether feedback has been received or not
  * @last_win_count - Last window counter sent
  * @t_last_win_count - Timestamp of earliest packet with
  *                     last_win_count value sent
@@ -105,7 +98,7 @@ struct ccid3_hc_tx_sock {
 	u32				t_rto;
 	u32				t_ipi;
 	u16				s;
-	enum ccid3_hc_tx_states		state:8;
+	bool				feedback:1;
 	u8				last_win_count;
 	ktime_t				t_last_win_count;
 	struct timer_list		no_feedback_timer;