[PATCHES 0/5]: DCCP patches for 2.6.25

[PATCHES 0/5]: DCCP patches for 2.6.25

[Arnaldo Carvalho de Melo]

Hi David,

	Please consider pulling from:

master.kernel.org:/pub/scm/linux/kernel/git/acme/net-2.6.25

Best Regards,

- Arnaldo

net/dccp/ccids/ccid3.c |  252 +++++++++++++++++++++++++++++-----------------------------
net/dccp/ccids/ccid3.h |    8 -
net/dccp/dccp.h        |    6 -
3 files changed, 130 insertions(+), 136 deletions(-)

[PATCH 1/5] [CCID3]: Use a function to update p_inv, and p is never used

[Arnaldo Carvalho de Melo]

From: Gerrit Renker <gerrit@erg.abdn.ac.uk>

This patch
 1) concentrates previously scattered computation of p_inv into one function;
 2) removes the `p' element of the CCID3 RX sock (it is redundant);
 3) makes the tfrc_rx_info structure standalone, only used on demand.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 net/dccp/ccids/ccid3.c |   11 ++++++++---
 net/dccp/ccids/ccid3.h |    8 ++++----
 2 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/net/dccp/ccids/ccid3.c b/net/dccp/ccids/ccid3.c
index 876c747..90e0454 100644
--- a/net/dccp/ccids/ccid3.c
+++ b/net/dccp/ccids/ccid3.c
@@ -917,6 +917,7 @@ static int ccid3_hc_rx_getsockopt(struct sock *sk, const int optname, int len,
 				  u32 __user *optval, int __user *optlen)
 {
 	const struct ccid3_hc_rx_sock *hcrx;
+	struct tfrc_rx_info rx_info;
 	const void *val;
 
 	/* Listen socks doesn't have a private CCID block */
@@ -926,10 +927,14 @@ static int ccid3_hc_rx_getsockopt(struct sock *sk, const int optname, int len,
 	hcrx = ccid3_hc_rx_sk(sk);
 	switch (optname) {
 	case DCCP_SOCKOPT_CCID_RX_INFO:
-		if (len < sizeof(hcrx->ccid3hcrx_tfrc))
+		if (len < sizeof(rx_info))
 			return -EINVAL;
-		len = sizeof(hcrx->ccid3hcrx_tfrc);
-		val = &hcrx->ccid3hcrx_tfrc;
+		rx_info.tfrcrx_x_recv = hcrx->ccid3hcrx_x_recv;
+		rx_info.tfrcrx_rtt    = hcrx->ccid3hcrx_rtt;
+		rx_info.tfrcrx_p      = hcrx->ccid3hcrx_pinv == 0 ? ~0U :
+					   scaled_div(1, hcrx->ccid3hcrx_pinv);
+		len = sizeof(rx_info);
+		val = &rx_info;
 		break;
 	default:
 		return -ENOPROTOOPT;
diff --git a/net/dccp/ccids/ccid3.h b/net/dccp/ccids/ccid3.h
index e9f6ff4..49ca32b 100644
--- a/net/dccp/ccids/ccid3.h
+++ b/net/dccp/ccids/ccid3.h
@@ -139,6 +139,8 @@ enum ccid3_hc_rx_states {
  *  @ccid3hcrx_last_counter  -  Tracks window counter (RFC 4342, 8.1)
  *  @ccid3hcrx_state  -  Receiver state, one of %ccid3_hc_rx_states
  *  @ccid3hcrx_bytes_recv  -  Total sum of DCCP payload bytes
+ *  @ccid3hcrx_x_recv  -  Receiver estimate of send rate (RFC 3448, sec. 4.3)
+ *  @ccid3hcrx_rtt  -  Receiver estimate of RTT
  *  @ccid3hcrx_tstamp_last_feedback  -  Time at which last feedback was sent
  *  @ccid3hcrx_tstamp_last_ack  -  Time at which last feedback was sent
  *  @ccid3hcrx_hist  -  Packet history (loss detection + RTT sampling)
@@ -147,13 +149,11 @@ enum ccid3_hc_rx_states {
  *  @ccid3hcrx_pinv  -  Inverse of Loss Event Rate (RFC 4342, sec. 8.5)
  */
 struct ccid3_hc_rx_sock {
-	struct tfrc_rx_info		ccid3hcrx_tfrc;
-#define ccid3hcrx_x_recv		ccid3hcrx_tfrc.tfrcrx_x_recv
-#define ccid3hcrx_rtt			ccid3hcrx_tfrc.tfrcrx_rtt
-#define ccid3hcrx_p			ccid3hcrx_tfrc.tfrcrx_p
 	u8				ccid3hcrx_last_counter:4;
 	enum ccid3_hc_rx_states		ccid3hcrx_state:8;
 	u32				ccid3hcrx_bytes_recv;
+	u32				ccid3hcrx_x_recv;
+	u32				ccid3hcrx_rtt;
 	ktime_t				ccid3hcrx_tstamp_last_feedback;
 	struct tfrc_rx_hist		ccid3hcrx_hist;
 	struct tfrc_loss_hist		ccid3hcrx_li_hist;
-- 
1.5.3.6

[PATCH 2/5] [CCID3]: Remove two irrelevant states in TX feedback handling

[Arnaldo Carvalho de Melo]

From: Gerrit Renker <gerrit@erg.abdn.ac.uk>

 * the NO_SENT state is only triggered in bidirectional mode,
   costing unnecessary processing.
 * the TERM (terminating) state is irrelevant.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 net/dccp/ccids/ccid3.c |  173 +++++++++++++++++++++++-------------------------
 1 files changed, 84 insertions(+), 89 deletions(-)

diff --git a/net/dccp/ccids/ccid3.c b/net/dccp/ccids/ccid3.c
index 90e0454..1b1cb74 100644
--- a/net/dccp/ccids/ccid3.c
+++ b/net/dccp/ccids/ccid3.c
@@ -402,112 +402,107 @@ static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb)
 	if (!(DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_ACK ||
 	      DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_DATAACK))
 		return;
+	/* ... and only in the established state */
+	if (hctx->ccid3hctx_state != TFRC_SSTATE_FBACK &&
+	    hctx->ccid3hctx_state != TFRC_SSTATE_NO_FBACK)
+		return;
 
 	opt_recv = &hctx->ccid3hctx_options_received;
+	now = ktime_get_real();
 
-	switch (hctx->ccid3hctx_state) {
-	case TFRC_SSTATE_NO_FBACK:
-	case TFRC_SSTATE_FBACK:
-		now = ktime_get_real();
-
-		/* estimate RTT from history if ACK number is valid */
-		r_sample = tfrc_tx_hist_rtt(hctx->ccid3hctx_hist,
-					    DCCP_SKB_CB(skb)->dccpd_ack_seq, now);
-		if (r_sample == 0) {
-			DCCP_WARN("%s(%p): %s with bogus ACK-%llu\n", dccp_role(sk), sk,
-				  dccp_packet_name(DCCP_SKB_CB(skb)->dccpd_type),
-				  (unsigned long long)DCCP_SKB_CB(skb)->dccpd_ack_seq);
-			return;
-		}
+	/* Estimate RTT from history if ACK number is valid */
+	r_sample = tfrc_tx_hist_rtt(hctx->ccid3hctx_hist,
+				    DCCP_SKB_CB(skb)->dccpd_ack_seq, now);
+	if (r_sample == 0) {
+		DCCP_WARN("%s(%p): %s with bogus ACK-%llu\n", dccp_role(sk), sk,
+			  dccp_packet_name(DCCP_SKB_CB(skb)->dccpd_type),
+			  (unsigned long long)DCCP_SKB_CB(skb)->dccpd_ack_seq);
+		return;
+	}
+
+	/* Update receive rate in units of 64 * bytes/second */
+	hctx->ccid3hctx_x_recv = opt_recv->ccid3or_receive_rate;
+	hctx->ccid3hctx_x_recv <<= 6;
 
-		/* Update receive rate in units of 64 * bytes/second */
-		hctx->ccid3hctx_x_recv = opt_recv->ccid3or_receive_rate;
-		hctx->ccid3hctx_x_recv <<= 6;
+	/* Update loss event rate (which is scaled by 1e6) */
+	pinv = opt_recv->ccid3or_loss_event_rate;
+	if (pinv == ~0U || pinv == 0)	       /* see RFC 4342, 8.5   */
+		hctx->ccid3hctx_p = 0;
+	else				       /* can not exceed 100% */
+		hctx->ccid3hctx_p = 1000000 / pinv;
+	/*
+	 * Validate new RTT sample and update moving average
+	 */
+	r_sample = dccp_sample_rtt(sk, r_sample);
+	hctx->ccid3hctx_rtt = tfrc_ewma(hctx->ccid3hctx_rtt, r_sample, 9);
 
-		/* Update loss event rate */
-		pinv = opt_recv->ccid3or_loss_event_rate;
-		if (pinv == ~0U || pinv == 0)	       /* see RFC 4342, 8.5   */
-			hctx->ccid3hctx_p = 0;
-		else				       /* can not exceed 100% */
-			hctx->ccid3hctx_p = 1000000 / pinv;
+	if (hctx->ccid3hctx_state == TFRC_SSTATE_NO_FBACK) {
 		/*
-		 * Validate new RTT sample and update moving average
+		 * Larger Initial Windows [RFC 4342, sec. 5]
 		 */
-		r_sample = dccp_sample_rtt(sk, r_sample);
-		hctx->ccid3hctx_rtt = tfrc_ewma(hctx->ccid3hctx_rtt, r_sample, 9);
+		hctx->ccid3hctx_x    = rfc3390_initial_rate(sk);
+		hctx->ccid3hctx_t_ld = now;
 
-		if (hctx->ccid3hctx_state == TFRC_SSTATE_NO_FBACK) {
-			/*
-			 * Larger Initial Windows [RFC 4342, sec. 5]
-			 */
-			hctx->ccid3hctx_x    = rfc3390_initial_rate(sk);
-			hctx->ccid3hctx_t_ld = now;
+		ccid3_update_send_interval(hctx);
 
-			ccid3_update_send_interval(hctx);
+		ccid3_pr_debug("%s(%p), s=%u, MSS=%u, "
+			       "R_sample=%uus, X=%u\n", dccp_role(sk),
+			       sk, hctx->ccid3hctx_s,
+			       dccp_sk(sk)->dccps_mss_cache, r_sample,
+			       (unsigned)(hctx->ccid3hctx_x >> 6));
 
-			ccid3_pr_debug("%s(%p), s=%u, MSS=%u, "
-				       "R_sample=%uus, X=%u\n", dccp_role(sk),
-				       sk, hctx->ccid3hctx_s,
-				       dccp_sk(sk)->dccps_mss_cache, r_sample,
-				       (unsigned)(hctx->ccid3hctx_x >> 6));
+		ccid3_hc_tx_set_state(sk, TFRC_SSTATE_FBACK);
+	} else {
 
-			ccid3_hc_tx_set_state(sk, TFRC_SSTATE_FBACK);
-		} else {
+		/* Update sending rate (step 4 of [RFC 3448, 4.3]) */
+		if (hctx->ccid3hctx_p > 0)
+			hctx->ccid3hctx_x_calc =
+				tfrc_calc_x(hctx->ccid3hctx_s,
+					    hctx->ccid3hctx_rtt,
+					    hctx->ccid3hctx_p);
+		ccid3_hc_tx_update_x(sk, &now);
 
-			/* Update sending rate (step 4 of [RFC 3448, 4.3]) */
-			if (hctx->ccid3hctx_p > 0)
-				hctx->ccid3hctx_x_calc =
-					tfrc_calc_x(hctx->ccid3hctx_s,
-						    hctx->ccid3hctx_rtt,
-						    hctx->ccid3hctx_p);
-			ccid3_hc_tx_update_x(sk, &now);
-
-			ccid3_pr_debug("%s(%p), RTT=%uus (sample=%uus), s=%u, "
-				       "p=%u, X_calc=%u, X_recv=%u, X=%u\n",
-				       dccp_role(sk),
-				       sk, hctx->ccid3hctx_rtt, r_sample,
-				       hctx->ccid3hctx_s, hctx->ccid3hctx_p,
-				       hctx->ccid3hctx_x_calc,
-				       (unsigned)(hctx->ccid3hctx_x_recv >> 6),
-				       (unsigned)(hctx->ccid3hctx_x >> 6));
-		}
+		ccid3_pr_debug("%s(%p), RTT=%uus (sample=%uus), s=%u, "
+			       "p=%u, X_calc=%u, X_recv=%u, X=%u\n",
+			       dccp_role(sk),
+			       sk, hctx->ccid3hctx_rtt, r_sample,
+			       hctx->ccid3hctx_s, hctx->ccid3hctx_p,
+			       hctx->ccid3hctx_x_calc,
+			       (unsigned)(hctx->ccid3hctx_x_recv >> 6),
+			       (unsigned)(hctx->ccid3hctx_x >> 6));
+	}
 
-		/* unschedule no feedback timer */
-		sk_stop_timer(sk, &hctx->ccid3hctx_no_feedback_timer);
+	/* unschedule no feedback timer */
+	sk_stop_timer(sk, &hctx->ccid3hctx_no_feedback_timer);
 
-		/*
-		 * As we have calculated new ipi, delta, t_nom it is possible
-		 * that we now can send a packet, so wake up dccp_wait_for_ccid
-		 */
-		sk->sk_write_space(sk);
+	/*
+	 * As we have calculated new ipi, delta, t_nom it is possible
+	 * that we now can send a packet, so wake up dccp_wait_for_ccid
+	 */
+	sk->sk_write_space(sk);
 
-		/*
-		 * Update timeout interval for the nofeedback timer.
-		 * We use a configuration option to increase the lower bound.
-		 * This can help avoid triggering the nofeedback timer too
-		 * often ('spinning') on LANs with small RTTs.
-		 */
-		hctx->ccid3hctx_t_rto = max_t(u32, 4 * hctx->ccid3hctx_rtt,
-						   CONFIG_IP_DCCP_CCID3_RTO *
-						   (USEC_PER_SEC/1000));
-		/*
-		 * Schedule no feedback timer to expire in
-		 * max(t_RTO, 2 * s/X)  =  max(t_RTO, 2 * t_ipi)
-		 */
-		t_nfb = max(hctx->ccid3hctx_t_rto, 2 * hctx->ccid3hctx_t_ipi);
+	/*
+	 * Update timeout interval for the nofeedback timer.
+	 * We use a configuration option to increase the lower bound.
+	 * This can help avoid triggering the nofeedback timer too
+	 * often ('spinning') on LANs with small RTTs.
+	 */
+	hctx->ccid3hctx_t_rto = max_t(u32, 4 * hctx->ccid3hctx_rtt,
+					   (CONFIG_IP_DCCP_CCID3_RTO *
+					    (USEC_PER_SEC / 1000)));
+	/*
+	 * Schedule no feedback timer to expire in
+	 * max(t_RTO, 2 * s/X)  =  max(t_RTO, 2 * t_ipi)
+	 */
+	t_nfb = max(hctx->ccid3hctx_t_rto, 2 * hctx->ccid3hctx_t_ipi);
 
-		ccid3_pr_debug("%s(%p), Scheduled no feedback timer to "
-			       "expire in %lu jiffies (%luus)\n",
-			       dccp_role(sk),
-			       sk, usecs_to_jiffies(t_nfb), t_nfb);
+	ccid3_pr_debug("%s(%p), Scheduled no feedback timer to "
+		       "expire in %lu jiffies (%luus)\n",
+		       dccp_role(sk),
+		       sk, usecs_to_jiffies(t_nfb), t_nfb);
 
-		sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer,
-				   jiffies + usecs_to_jiffies(t_nfb));
-		break;
-	case TFRC_SSTATE_NO_SENT:	/* fall through */
-	case TFRC_SSTATE_TERM:		/* ignore feedback when closing */
-		break;
-	}
+	sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer,
+			   jiffies + usecs_to_jiffies(t_nfb));
 }
 
 static int ccid3_hc_tx_parse_options(struct sock *sk, unsigned char option,
-- 
1.5.3.6

[PATCH 3/5] [CCID3]: Implement rfc3448bis changes to feedback reception

[Arnaldo Carvalho de Melo]

From: Gerrit Renker <gerrit@erg.abdn.ac.uk>

This implements the algorithm to update the allowed sending rate X upon
receiving feedback packets, as described in draft rfc3448bis, 4.2/4.3.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 net/dccp/ccids/ccid3.c |   47 ++++++++++++++++++++++++++---------------------
 1 files changed, 26 insertions(+), 21 deletions(-)

diff --git a/net/dccp/ccids/ccid3.c b/net/dccp/ccids/ccid3.c
index 1b1cb74..7c8e9ad 100644
--- a/net/dccp/ccids/ccid3.c
+++ b/net/dccp/ccids/ccid3.c
@@ -429,40 +429,46 @@ static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb)
 	if (pinv == ~0U || pinv == 0)	       /* see RFC 4342, 8.5   */
 		hctx->ccid3hctx_p = 0;
 	else				       /* can not exceed 100% */
-		hctx->ccid3hctx_p = 1000000 / pinv;
+		hctx->ccid3hctx_p = scaled_div(1, pinv);
 	/*
 	 * Validate new RTT sample and update moving average
 	 */
 	r_sample = dccp_sample_rtt(sk, r_sample);
 	hctx->ccid3hctx_rtt = tfrc_ewma(hctx->ccid3hctx_rtt, r_sample, 9);
-
+	/*
+	 * Update allowed sending rate X as per draft rfc3448bis-00, 4.2/3
+	 */
 	if (hctx->ccid3hctx_state == TFRC_SSTATE_NO_FBACK) {
-		/*
-		 * Larger Initial Windows [RFC 4342, sec. 5]
-		 */
-		hctx->ccid3hctx_x    = rfc3390_initial_rate(sk);
-		hctx->ccid3hctx_t_ld = now;
+		ccid3_hc_tx_set_state(sk, TFRC_SSTATE_FBACK);
 
-		ccid3_update_send_interval(hctx);
+		if (hctx->ccid3hctx_t_rto == 0) {
+ 			/*
+			 * Initial feedback packet: Larger Initial Windows (4.2)
+ 			 */
+			hctx->ccid3hctx_x    = rfc3390_initial_rate(sk);
+			hctx->ccid3hctx_t_ld = now;
 
-		ccid3_pr_debug("%s(%p), s=%u, MSS=%u, "
-			       "R_sample=%uus, X=%u\n", dccp_role(sk),
-			       sk, hctx->ccid3hctx_s,
-			       dccp_sk(sk)->dccps_mss_cache, r_sample,
-			       (unsigned)(hctx->ccid3hctx_x >> 6));
+			ccid3_update_send_interval(hctx);
 
-		ccid3_hc_tx_set_state(sk, TFRC_SSTATE_FBACK);
-	} else {
+			goto done_computing_x;
+		} else if (hctx->ccid3hctx_p == 0) {
+			/*
+			 * First feedback after nofeedback timer expiry (4.3)
+			 */
+			goto done_computing_x;
+ 		}
+	}
 
-		/* Update sending rate (step 4 of [RFC 3448, 4.3]) */
-		if (hctx->ccid3hctx_p > 0)
-			hctx->ccid3hctx_x_calc =
+	/* Update sending rate (step 4 of [RFC 3448, 4.3]) */
+	if (hctx->ccid3hctx_p > 0)
+		hctx->ccid3hctx_x_calc =
 				tfrc_calc_x(hctx->ccid3hctx_s,
 					    hctx->ccid3hctx_rtt,
 					    hctx->ccid3hctx_p);
-		ccid3_hc_tx_update_x(sk, &now);
+	ccid3_hc_tx_update_x(sk, &now);
 
-		ccid3_pr_debug("%s(%p), RTT=%uus (sample=%uus), s=%u, "
+done_computing_x:
+	ccid3_pr_debug("%s(%p), RTT=%uus (sample=%uus), s=%u, "
 			       "p=%u, X_calc=%u, X_recv=%u, X=%u\n",
 			       dccp_role(sk),
 			       sk, hctx->ccid3hctx_rtt, r_sample,
@@ -470,7 +476,6 @@ static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb)
 			       hctx->ccid3hctx_x_calc,
 			       (unsigned)(hctx->ccid3hctx_x_recv >> 6),
 			       (unsigned)(hctx->ccid3hctx_x >> 6));
-	}
 
 	/* unschedule no feedback timer */
 	sk_stop_timer(sk, &hctx->ccid3hctx_no_feedback_timer);
-- 
1.5.3.6

[PATCH 4/5] [CCID3]: Nofeedback timer according to rfc3448bis

[Arnaldo Carvalho de Melo]

From: Gerrit Renker <gerrit@erg.abdn.ac.uk>

This implements the changes to the nofeedback timer handling suggested
in draft rfc3448bis00, section 4.4. In particular, these changes mean:

 * better handling of the lossless case (p == 0)
 * the timestamp for computing t_ld becomes obsolete
 * much more recent document (RFC 3448 is almost 5 years old)
 * concepts in rfc3448bis arose from a real, working implementation
   (cf. sec. 12)

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 net/dccp/ccids/ccid3.c |   63 ++++++++++++++++++++++--------------------------
 1 files changed, 29 insertions(+), 34 deletions(-)

diff --git a/net/dccp/ccids/ccid3.c b/net/dccp/ccids/ccid3.c
index 7c8e9ad..00b5f11 100644
--- a/net/dccp/ccids/ccid3.c
+++ b/net/dccp/ccids/ccid3.c
@@ -131,12 +131,11 @@ static u32 ccid3_hc_tx_idle_rtt(struct ccid3_hc_tx_sock *hctx, ktime_t now)
  *
  */
 static void ccid3_hc_tx_update_x(struct sock *sk, ktime_t *stamp)
-
 {
 	struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
 	__u64 min_rate = 2 * hctx->ccid3hctx_x_recv;
 	const  __u64 old_x = hctx->ccid3hctx_x;
-	ktime_t now = stamp? *stamp : ktime_get_real();
+	ktime_t now = stamp ? *stamp : ktime_get_real();
 
 	/*
 	 * Handle IDLE periods: do not reduce below RFC3390 initial sending rate
@@ -230,27 +229,27 @@ static void ccid3_hc_tx_no_feedback_timer(unsigned long data)
 	ccid3_pr_debug("%s(%p, state=%s) - entry \n", dccp_role(sk), sk,
 		       ccid3_tx_state_name(hctx->ccid3hctx_state));
 
-	switch (hctx->ccid3hctx_state) {
-	case TFRC_SSTATE_NO_FBACK:
-		/* RFC 3448, 4.4: Halve send rate directly */
+	if (hctx->ccid3hctx_state == TFRC_SSTATE_FBACK)
+		ccid3_hc_tx_set_state(sk, TFRC_SSTATE_NO_FBACK);
+	else if (hctx->ccid3hctx_state != TFRC_SSTATE_NO_FBACK)
+		goto out;
+
+	/*
+	 * Determine new allowed sending rate X as per draft rfc3448bis-00, 4.4
+	 */
+	if (hctx->ccid3hctx_t_rto == 0 ||	/* no feedback received yet */
+	    hctx->ccid3hctx_p == 0) {
+
+		/* halve send rate directly */
 		hctx->ccid3hctx_x = max(hctx->ccid3hctx_x / 2,
 					(((__u64)hctx->ccid3hctx_s) << 6) /
 								    TFRC_T_MBI);
-
-		ccid3_pr_debug("%s(%p, state=%s), updated tx rate to %u "
-			       "bytes/s\n", dccp_role(sk), sk,
-			       ccid3_tx_state_name(hctx->ccid3hctx_state),
-			       (unsigned)(hctx->ccid3hctx_x >> 6));
-		/* The value of R is still undefined and so we can not recompute
-		 * the timout value. Keep initial value as per [RFC 4342, 5]. */
-		t_nfb = TFRC_INITIAL_TIMEOUT;
 		ccid3_update_send_interval(hctx);
-		break;
-	case TFRC_SSTATE_FBACK:
+	} else {
 		/*
-		 *  Modify the cached value of X_recv [RFC 3448, 4.4]
+		 *  Modify the cached value of X_recv
 		 *
-		 *  If (p == 0 || X_calc > 2 * X_recv)
+		 *  If (X_calc > 2 * X_recv)
 		 *    X_recv = max(X_recv / 2, s / (2 * t_mbi));
 		 *  Else
 		 *    X_recv = X_calc / 4;
@@ -259,32 +258,28 @@ static void ccid3_hc_tx_no_feedback_timer(unsigned long data)
 		 */
 		BUG_ON(hctx->ccid3hctx_p && !hctx->ccid3hctx_x_calc);
 
-		if (hctx->ccid3hctx_p == 0 ||
-		    (hctx->ccid3hctx_x_calc > (hctx->ccid3hctx_x_recv >> 5))) {
-
+		if (hctx->ccid3hctx_x_calc > (hctx->ccid3hctx_x_recv >> 5))
 			hctx->ccid3hctx_x_recv =
 				max(hctx->ccid3hctx_x_recv / 2,
 				    (((__u64)hctx->ccid3hctx_s) << 6) /
 							      (2 * TFRC_T_MBI));
-		} else {
+		else {
 			hctx->ccid3hctx_x_recv = hctx->ccid3hctx_x_calc;
 			hctx->ccid3hctx_x_recv <<= 4;
 		}
-		/* Now recalculate X [RFC 3448, 4.3, step (4)] */
 		ccid3_hc_tx_update_x(sk, NULL);
-		/*
-		 * Schedule no feedback timer to expire in
-		 * max(t_RTO, 2 * s/X)  =  max(t_RTO, 2 * t_ipi)
-		 * See comments in packet_recv() regarding the value of t_RTO.
-		 */
-		t_nfb = max(hctx->ccid3hctx_t_rto, 2 * hctx->ccid3hctx_t_ipi);
-		break;
-	case TFRC_SSTATE_NO_SENT:
-		DCCP_BUG("%s(%p) - Illegal state NO_SENT", dccp_role(sk), sk);
-		/* fall through */
-	case TFRC_SSTATE_TERM:
-		goto out;
 	}
+	ccid3_pr_debug("Reduced X to %llu/64 bytes/sec\n",
+			(unsigned long long)hctx->ccid3hctx_x);
+
+	/*
+	 * Set new timeout for the nofeedback timer.
+	 * See comments in packet_recv() regarding the value of t_RTO.
+	 */
+	if (unlikely(hctx->ccid3hctx_t_rto == 0))	/* no feedback yet */
+		t_nfb = TFRC_INITIAL_TIMEOUT;
+	else
+		t_nfb = max(hctx->ccid3hctx_t_rto, 2 * hctx->ccid3hctx_t_ipi);
 
 restart_timer:
 	sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer,
-- 
1.5.3.6

[PATCH 5/5] [DCCP]: Remove unused inline function

[Arnaldo Carvalho de Melo]

From: Gerrit Renker <gerrit@erg.abdn.ac.uk>

The function follows48(), which is a special-case of dccp_delta_seqno(),
is nowhere used in the DCCP code, thus removed by this patch.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 net/dccp/dccp.h |    6 ------
 1 files changed, 0 insertions(+), 6 deletions(-)

diff --git a/net/dccp/dccp.h b/net/dccp/dccp.h
index b138e20..ebe59d9 100644
--- a/net/dccp/dccp.h
+++ b/net/dccp/dccp.h
@@ -153,12 +153,6 @@ static inline u64 max48(const u64 seq1, const u64 seq2)
 	return after48(seq1, seq2) ? seq1 : seq2;
 }
 
-/* is seq1 next seqno after seq2 */
-static inline int follows48(const u64 seq1, const u64 seq2)
-{
-	return dccp_delta_seqno(seq2, seq1) == 1;
-}
-
 enum {
 	DCCP_MIB_NUM = 0,
 	DCCP_MIB_ACTIVEOPENS,			/* ActiveOpens */
-- 
1.5.3.6

Re: [PATCHES 0/5]: DCCP patches for 2.6.25

[David Miller]

From: Arnaldo Carvalho de Melo <acme@redhat.com>
Date: Mon, 17 Dec 2007 13:00:14 -0200

> 	Please consider pulling from:
> 
> master.kernel.org:/pub/scm/linux/kernel/git/acme/net-2.6.25

Pulled and pushed out, thanks!