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Message-Id: <1217325952-12337-3-git-send-email-gerrit@erg.abdn.ac.uk>
Date: Tue, 29 Jul 2008 11:05:47 +0100
From: Gerrit Renker <gerrit@....abdn.ac.uk>
To: dccp@...r.kernel.org
Cc: netdev@...r.kernel.org, Gerrit Renker <gerrit@....abdn.ac.uk>
Subject: [PATCH 2/7] dccp ccid-3: Remove redundant RX states
The only state information that the CCID-3 receiver keeps is whether initial
feedback has been sent or not. Further, this overlaps with use of feedback:
* state == TFRC_RSTATE_NO_DATA as long as no feedback has been sent;
* state == TFRC_RSTATE_DATA as soon as the first feedback has been sent.
This patch reduces the duplication, by memorising the type of the last feedback.
Signed-off-by: Gerrit Renker <gerrit@....abdn.ac.uk>
---
net/dccp/ccids/ccid3.c | 47 +++++------------------------------------------
net/dccp/ccids/ccid3.h | 14 ++++++++------
2 files changed, 13 insertions(+), 48 deletions(-)
--- a/net/dccp/ccids/ccid3.h
+++ b/net/dccp/ccids/ccid3.h
@@ -114,16 +114,18 @@ static inline struct ccid3_hc_tx_sock *ccid3_hc_tx_sk(const struct sock *sk)
return hctx;
}
-/* TFRC receiver states */
-enum ccid3_hc_rx_states {
- TFRC_RSTATE_NO_DATA = 1,
- TFRC_RSTATE_DATA,
+
+enum ccid3_fback_type {
+ CCID3_FBACK_NONE = 0,
+ CCID3_FBACK_INITIAL,
+ CCID3_FBACK_PERIODIC,
+ CCID3_FBACK_PARAM_CHANGE
};
/** struct ccid3_hc_rx_sock - CCID3 receiver half-connection socket
*
* @last_counter - Tracks window counter (RFC 4342, 8.1)
- * @state - Receiver state, one of %ccid3_hc_rx_states
+ * @feedback - The type of the feedback last sent
* @x_recv - Receiver estimate of send rate (RFC 3448, sec. 4.3)
* @rtt - Receiver estimate of RTT
* @tstamp_last_feedback - Time at which last feedback was sent
@@ -133,7 +135,7 @@ enum ccid3_hc_rx_states {
*/
struct ccid3_hc_rx_sock {
u8 last_counter:4;
- enum ccid3_hc_rx_states state:8;
+ enum ccid3_fback_type feedback:4;
u32 x_recv;
u32 rtt;
ktime_t tstamp_last_feedback;
--- a/net/dccp/ccids/ccid3.c
+++ b/net/dccp/ccids/ccid3.c
@@ -528,40 +528,6 @@ static int ccid3_hc_tx_getsockopt(struct sock *sk, const int optname, int len,
/*
* Receiver Half-Connection Routines
*/
-
-/* CCID3 feedback types */
-enum ccid3_fback_type {
- CCID3_FBACK_NONE = 0,
- CCID3_FBACK_INITIAL,
- CCID3_FBACK_PERIODIC,
- CCID3_FBACK_PARAM_CHANGE
-};
-
-#ifdef CONFIG_IP_DCCP_CCID3_DEBUG
-static const char *ccid3_rx_state_name(enum ccid3_hc_rx_states state)
-{
- static char *ccid3_rx_state_names[] = {
- [TFRC_RSTATE_NO_DATA] = "NO_DATA",
- [TFRC_RSTATE_DATA] = "DATA",
- };
-
- return ccid3_rx_state_names[state];
-}
-#endif
-
-static void ccid3_hc_rx_set_state(struct sock *sk,
- enum ccid3_hc_rx_states state)
-{
- struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
- enum ccid3_hc_rx_states oldstate = hcrx->state;
-
- ccid3_pr_debug("%s(%p) %-8.8s -> %s\n",
- dccp_role(sk), sk, ccid3_rx_state_name(oldstate),
- ccid3_rx_state_name(state));
- WARN_ON(state == oldstate);
- hcrx->state = state;
-}
-
static void ccid3_hc_rx_send_feedback(struct sock *sk,
const struct sk_buff *skb,
enum ccid3_fback_type fbtype)
@@ -577,7 +543,7 @@ static void ccid3_hc_rx_send_feedback(struct sock *sk,
hcrx->p_inverse = ~0U; /* see RFC 4342, 8.5 */
break;
case CCID3_FBACK_PARAM_CHANGE:
- if (unlikely(hcrx->state == TFRC_RSTATE_NO_DATA)) {
+ if (unlikely(hcrx->feedback == CCID3_FBACK_NONE)) {
/*
* rfc3448bis-06, 6.3.1: First packet(s) lost or marked
* FIXME: in rfc3448bis the receiver returns X_recv=0
@@ -626,6 +592,7 @@ static void ccid3_hc_rx_send_feedback(struct sock *sk,
hcrx->tstamp_last_feedback = now;
hcrx->last_counter = dccp_hdr(skb)->dccph_ccval;
hcrx->hist.bytes_recvd = 0;
+ hcrx->feedback = fbtype;
dp->dccps_hc_rx_insert_options = 1;
dccp_send_ack(sk);
@@ -675,7 +642,7 @@ static u32 ccid3_first_li(struct sock *sk)
* to give the equivalent of X_target = s/(2*R). Thus fval = 2 and so p
* is about 20.64%. This yields an interval length of 4.84 (rounded up).
*/
- if (unlikely(hcrx->state == TFRC_RSTATE_NO_DATA))
+ if (unlikely(hcrx->feedback == CCID3_FBACK_NONE))
return 5;
if (hcrx->rtt == 0) {
@@ -719,11 +686,9 @@ static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb)
goto done_receiving;
}
- if (unlikely(hcrx->state == TFRC_RSTATE_NO_DATA)) {
- if (is_data_packet) {
+ if (unlikely(hcrx->feedback == CCID3_FBACK_NONE)) {
+ if (is_data_packet)
do_feedback = CCID3_FBACK_INITIAL;
- ccid3_hc_rx_set_state(sk, TFRC_RSTATE_DATA);
- }
goto update_records;
}
@@ -764,7 +729,6 @@ static int ccid3_hc_rx_init(struct ccid *ccid, struct sock *sk)
{
struct ccid3_hc_rx_sock *hcrx = ccid_priv(ccid);
- hcrx->state = TFRC_RSTATE_NO_DATA;
tfrc_lh_init(&hcrx->li_hist);
return tfrc_rx_hist_init(&hcrx->hist, sk);
}
@@ -779,7 +743,6 @@ static void ccid3_hc_rx_exit(struct sock *sk)
static void ccid3_hc_rx_get_info(struct sock *sk, struct tcp_info *info)
{
- info->tcpi_ca_state = ccid3_hc_rx_sk(sk)->state;
info->tcpi_options |= TCPI_OPT_TIMESTAMPS;
info->tcpi_rcv_rtt = ccid3_hc_rx_sk(sk)->rtt;
}
--
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