1 files changed, 272 insertions, 389 deletions

diff --git a/net/dccp/ccids/ccid3.c b/net/dccp/ccids/ccid3.c
index e76f460af0e..119c04317d4 100644
--- a/net/dccp/ccids/ccid3.c
+++ b/net/dccp/ccids/ccid3.c
@@ -1,6 +1,4 @@
 /*
- *  net/dccp/ccids/ccid3.c
- *
  *  Copyright (c) 2007   The University of Aberdeen, Scotland, UK
  *  Copyright (c) 2005-7 The University of Waikato, Hamilton, New Zealand.
  *  Copyright (c) 2005-7 Ian McDonald <ian.mcdonald@jandi.co.nz>
@@ -40,7 +38,7 @@
 #include <asm/unaligned.h>
 
 #ifdef CONFIG_IP_DCCP_CCID3_DEBUG
-static int ccid3_debug;
+static bool ccid3_debug;
 #define ccid3_pr_debug(format, a...)	DCCP_PR_DEBUG(ccid3_debug, format, ##a)
 #else
 #define ccid3_pr_debug(format, a...)
@@ -52,11 +50,10 @@ static int ccid3_debug;
 #ifdef CONFIG_IP_DCCP_CCID3_DEBUG
 static const char *ccid3_tx_state_name(enum ccid3_hc_tx_states state)
 {
-	static char *ccid3_state_names[] = {
+	static const char *const ccid3_state_names[] = {
 	[TFRC_SSTATE_NO_SENT]  = "NO_SENT",
 	[TFRC_SSTATE_NO_FBACK] = "NO_FBACK",
 	[TFRC_SSTATE_FBACK]    = "FBACK",
-	[TFRC_SSTATE_TERM]     = "TERM",
 	};
 
 	return ccid3_state_names[state];
@@ -66,14 +63,14 @@ static const char *ccid3_tx_state_name(enum ccid3_hc_tx_states state)
 static void ccid3_hc_tx_set_state(struct sock *sk,
 				  enum ccid3_hc_tx_states state)
 {
-	struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
-	enum ccid3_hc_tx_states oldstate = hctx->ccid3hctx_state;
+	struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk);
+	enum ccid3_hc_tx_states oldstate = hc->tx_state;
 
 	ccid3_pr_debug("%s(%p) %-8.8s -> %s\n",
 		       dccp_role(sk), sk, ccid3_tx_state_name(oldstate),
 		       ccid3_tx_state_name(state));
 	WARN_ON(state == oldstate);
-	hctx->ccid3hctx_state = state;
+	hc->tx_state = state;
 }
 
 /*
@@ -87,42 +84,36 @@ static void ccid3_hc_tx_set_state(struct sock *sk,
  */
 static inline u64 rfc3390_initial_rate(struct sock *sk)
 {
-	const struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
-	const __u32 w_init = min_t(__u32, 4 * hctx->ccid3hctx_s,
-				   max_t(__u32, 2 * hctx->ccid3hctx_s, 4380));
+	const struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk);
+	const __u32 w_init = clamp_t(__u32, 4380U, 2 * hc->tx_s, 4 * hc->tx_s);
 
-	return scaled_div(w_init << 6, hctx->ccid3hctx_rtt);
+	return scaled_div(w_init << 6, hc->tx_rtt);
 }
 
-/*
- * Recalculate t_ipi and delta (should be called whenever X changes)
+/**
+ * ccid3_update_send_interval  -  Calculate new t_ipi = s / X_inst
+ * This respects the granularity of X_inst (64 * bytes/second).
  */
-static void ccid3_update_send_interval(struct ccid3_hc_tx_sock *hctx)
+static void ccid3_update_send_interval(struct ccid3_hc_tx_sock *hc)
 {
-	/* Calculate new t_ipi = s / X_inst (X_inst is in 64 * bytes/second) */
-	hctx->ccid3hctx_t_ipi = scaled_div32(((u64)hctx->ccid3hctx_s) << 6,
-					     hctx->ccid3hctx_x);
-
-	/* Calculate new delta by delta = min(t_ipi / 2, t_gran / 2) */
-	hctx->ccid3hctx_delta = min_t(u32, hctx->ccid3hctx_t_ipi / 2,
-					   TFRC_OPSYS_HALF_TIME_GRAN);
-
-	ccid3_pr_debug("t_ipi=%u, delta=%u, s=%u, X=%u\n",
-		       hctx->ccid3hctx_t_ipi, hctx->ccid3hctx_delta,
-		       hctx->ccid3hctx_s, (unsigned)(hctx->ccid3hctx_x >> 6));
+	hc->tx_t_ipi = scaled_div32(((u64)hc->tx_s) << 6, hc->tx_x);
 
+	DCCP_BUG_ON(hc->tx_t_ipi == 0);
+	ccid3_pr_debug("t_ipi=%u, s=%u, X=%u\n", hc->tx_t_ipi,
+		       hc->tx_s, (unsigned int)(hc->tx_x >> 6));
 }
 
-static u32 ccid3_hc_tx_idle_rtt(struct ccid3_hc_tx_sock *hctx, ktime_t now)
+static u32 ccid3_hc_tx_idle_rtt(struct ccid3_hc_tx_sock *hc, ktime_t now)
 {
-	u32 delta = ktime_us_delta(now, hctx->ccid3hctx_t_last_win_count);
+	u32 delta = ktime_us_delta(now, hc->tx_t_last_win_count);
 
-	return delta / hctx->ccid3hctx_rtt;
+	return delta / hc->tx_rtt;
 }
 
 /**
  * ccid3_hc_tx_update_x  -  Update allowed sending rate X
  * @stamp: most recent time if available - can be left NULL.
+ *
  * This function tracks draft rfc3448bis, check there for latest details.
  *
  * Note: X and X_recv are both stored in units of 64 * bytes/second, to support
@@ -132,9 +123,9 @@ 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;
+	struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk);
+	__u64 min_rate = 2 * hc->tx_x_recv;
+	const __u64 old_x = hc->tx_x;
 	ktime_t now = stamp ? *stamp : ktime_get_real();
 
 	/*
@@ -143,80 +134,71 @@ static void ccid3_hc_tx_update_x(struct sock *sk, ktime_t *stamp)
 	 * a sender is idle if it has not sent anything over a 2-RTT-period.
 	 * For consistency with X and X_recv, min_rate is also scaled by 2^6.
 	 */
-	if (ccid3_hc_tx_idle_rtt(hctx, now) >= 2) {
+	if (ccid3_hc_tx_idle_rtt(hc, now) >= 2) {
 		min_rate = rfc3390_initial_rate(sk);
-		min_rate = max(min_rate, 2 * hctx->ccid3hctx_x_recv);
+		min_rate = max(min_rate, 2 * hc->tx_x_recv);
 	}
 
-	if (hctx->ccid3hctx_p > 0) {
+	if (hc->tx_p > 0) {
 
-		hctx->ccid3hctx_x = min(((__u64)hctx->ccid3hctx_x_calc) << 6,
-					min_rate);
-		hctx->ccid3hctx_x = max(hctx->ccid3hctx_x,
-					(((__u64)hctx->ccid3hctx_s) << 6) /
-								TFRC_T_MBI);
+		hc->tx_x = min(((__u64)hc->tx_x_calc) << 6, min_rate);
+		hc->tx_x = max(hc->tx_x, (((__u64)hc->tx_s) << 6) / TFRC_T_MBI);
 
-	} else if (ktime_us_delta(now, hctx->ccid3hctx_t_ld)
-				- (s64)hctx->ccid3hctx_rtt >= 0) {
+	} else if (ktime_us_delta(now, hc->tx_t_ld) - (s64)hc->tx_rtt >= 0) {
 
-		hctx->ccid3hctx_x =
-			max(min(2 * hctx->ccid3hctx_x, min_rate),
-			    scaled_div(((__u64)hctx->ccid3hctx_s) << 6,
-				       hctx->ccid3hctx_rtt));
-		hctx->ccid3hctx_t_ld = now;
+		hc->tx_x = min(2 * hc->tx_x, min_rate);
+		hc->tx_x = max(hc->tx_x,
+			       scaled_div(((__u64)hc->tx_s) << 6, hc->tx_rtt));
+		hc->tx_t_ld = now;
 	}
 
-	if (hctx->ccid3hctx_x != old_x) {
+	if (hc->tx_x != old_x) {
 		ccid3_pr_debug("X_prev=%u, X_now=%u, X_calc=%u, "
-			       "X_recv=%u\n", (unsigned)(old_x >> 6),
-			       (unsigned)(hctx->ccid3hctx_x >> 6),
-			       hctx->ccid3hctx_x_calc,
-			       (unsigned)(hctx->ccid3hctx_x_recv >> 6));
+			       "X_recv=%u\n", (unsigned int)(old_x >> 6),
+			       (unsigned int)(hc->tx_x >> 6), hc->tx_x_calc,
+			       (unsigned int)(hc->tx_x_recv >> 6));
 
-		ccid3_update_send_interval(hctx);
+		ccid3_update_send_interval(hc);
 	}
 }
 
-/*
- *	Track the mean packet size `s' (cf. RFC 4342, 5.3 and  RFC 3448, 4.1)
+/**
+ *	ccid3_hc_tx_update_s - Track the mean packet size `s'
  *	@len: DCCP packet payload size in bytes
+ *
+ *	cf. RFC 4342, 5.3 and  RFC 3448, 4.1
  */
-static inline void ccid3_hc_tx_update_s(struct ccid3_hc_tx_sock *hctx, int len)
+static inline void ccid3_hc_tx_update_s(struct ccid3_hc_tx_sock *hc, int len)
 {
-	const u16 old_s = hctx->ccid3hctx_s;
+	const u16 old_s = hc->tx_s;
 
-	hctx->ccid3hctx_s = tfrc_ewma(hctx->ccid3hctx_s, len, 9);
+	hc->tx_s = tfrc_ewma(hc->tx_s, len, 9);
 
-	if (hctx->ccid3hctx_s != old_s)
-		ccid3_update_send_interval(hctx);
+	if (hc->tx_s != old_s)
+		ccid3_update_send_interval(hc);
 }
 
 /*
  *	Update Window Counter using the algorithm from [RFC 4342, 8.1].
- *	The algorithm is not applicable if RTT < 4 microseconds.
+ *	As elsewhere, RTT > 0 is assumed by using dccp_sample_rtt().
  */
-static inline void ccid3_hc_tx_update_win_count(struct ccid3_hc_tx_sock *hctx,
+static inline void ccid3_hc_tx_update_win_count(struct ccid3_hc_tx_sock *hc,
 						ktime_t now)
 {
-	u32 quarter_rtts;
-
-	if (unlikely(hctx->ccid3hctx_rtt < 4))	/* avoid divide-by-zero */
-		return;
-
-	quarter_rtts = ktime_us_delta(now, hctx->ccid3hctx_t_last_win_count);
-	quarter_rtts /= hctx->ccid3hctx_rtt / 4;
+	u32 delta = ktime_us_delta(now, hc->tx_t_last_win_count),
+	    quarter_rtts = (4 * delta) / hc->tx_rtt;
 
 	if (quarter_rtts > 0) {
-		hctx->ccid3hctx_t_last_win_count = now;
-		hctx->ccid3hctx_last_win_count	+= min_t(u32, quarter_rtts, 5);
-		hctx->ccid3hctx_last_win_count	&= 0xF;		/* mod 16 */
+		hc->tx_t_last_win_count = now;
+		hc->tx_last_win_count  += min(quarter_rtts, 5U);
+		hc->tx_last_win_count  &= 0xF;		/* mod 16 */
 	}
 }
 
 static void ccid3_hc_tx_no_feedback_timer(unsigned long data)
 {
 	struct sock *sk = (struct sock *)data;
-	struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
+	struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk);
 	unsigned long t_nfb = USEC_PER_SEC / 5;
 
 	bh_lock_sock(sk);
@@ -226,25 +208,27 @@ static void ccid3_hc_tx_no_feedback_timer(unsigned long data)
 		goto restart_timer;
 	}
 
-	ccid3_pr_debug("%s(%p, state=%s) - entry \n", dccp_role(sk), sk,
-		       ccid3_tx_state_name(hctx->ccid3hctx_state));
+	ccid3_pr_debug("%s(%p, state=%s) - entry\n", dccp_role(sk), sk,
+		       ccid3_tx_state_name(hc->tx_state));
 
-	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)
+	/* Ignore and do not restart after leaving the established state */
+	if ((1 << sk->sk_state) & ~(DCCPF_OPEN | DCCPF_PARTOPEN))
 		goto out;
 
+	/* Reset feedback state to "no feedback received" */
+	if (hc->tx_state == TFRC_SSTATE_FBACK)
+		ccid3_hc_tx_set_state(sk, TFRC_SSTATE_NO_FBACK);
+
 	/*
 	 * Determine new allowed sending rate X as per draft rfc3448bis-00, 4.4
+	 * RTO is 0 if and only if no feedback has been received yet.
 	 */
-	if (hctx->ccid3hctx_t_rto == 0 ||	/* no feedback received yet */
-	    hctx->ccid3hctx_p == 0) {
+	if (hc->tx_t_rto == 0 || hc->tx_p == 0) {
 
 		/* halve send rate directly */
-		hctx->ccid3hctx_x = max(hctx->ccid3hctx_x / 2,
-					(((__u64)hctx->ccid3hctx_s) << 6) /
-								    TFRC_T_MBI);
-		ccid3_update_send_interval(hctx);
+		hc->tx_x = max(hc->tx_x / 2,
+			       (((__u64)hc->tx_s) << 6) / TFRC_T_MBI);
+		ccid3_update_send_interval(hc);
 	} else {
 		/*
 		 *  Modify the cached value of X_recv
@@ -256,49 +240,47 @@ static void ccid3_hc_tx_no_feedback_timer(unsigned long data)
 		 *
 		 *  Note that X_recv is scaled by 2^6 while X_calc is not
 		 */
-		BUG_ON(hctx->ccid3hctx_p && !hctx->ccid3hctx_x_calc);
-
-		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));
+		if (hc->tx_x_calc > (hc->tx_x_recv >> 5))
+			hc->tx_x_recv =
+				max(hc->tx_x_recv / 2,
+				    (((__u64)hc->tx_s) << 6) / (2*TFRC_T_MBI));
 		else {
-			hctx->ccid3hctx_x_recv = hctx->ccid3hctx_x_calc;
-			hctx->ccid3hctx_x_recv <<= 4;
+			hc->tx_x_recv = hc->tx_x_calc;
+			hc->tx_x_recv <<= 4;
 		}
 		ccid3_hc_tx_update_x(sk, NULL);
 	}
 	ccid3_pr_debug("Reduced X to %llu/64 bytes/sec\n",
-			(unsigned long long)hctx->ccid3hctx_x);
+			(unsigned long long)hc->tx_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 */
+	if (unlikely(hc->tx_t_rto == 0))	/* no feedback received yet */
 		t_nfb = TFRC_INITIAL_TIMEOUT;
 	else
-		t_nfb = max(hctx->ccid3hctx_t_rto, 2 * hctx->ccid3hctx_t_ipi);
+		t_nfb = max(hc->tx_t_rto, 2 * hc->tx_t_ipi);
 
 restart_timer:
-	sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer,
+	sk_reset_timer(sk, &hc->tx_no_feedback_timer,
 			   jiffies + usecs_to_jiffies(t_nfb));
 out:
 	bh_unlock_sock(sk);
 	sock_put(sk);
 }
 
-/*
- * returns
- *   > 0: delay (in msecs) that should pass before actually sending
- *   = 0: can send immediately
- *   < 0: error condition; do not send packet
+/**
+ * ccid3_hc_tx_send_packet  -  Delay-based dequeueing of TX packets
+ * @skb: next packet candidate to send on @sk
+ *
+ * This function uses the convention of ccid_packet_dequeue_eval() and
+ * returns a millisecond-delay value between 0 and t_mbi = 64000 msec.
  */
 static int ccid3_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb)
 {
 	struct dccp_sock *dp = dccp_sk(sk);
-	struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
+	struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk);
 	ktime_t now = ktime_get_real();
 	s64 delay;
 
@@ -310,18 +292,16 @@ static int ccid3_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb)
 	if (unlikely(skb->len == 0))
 		return -EBADMSG;
 
-	switch (hctx->ccid3hctx_state) {
-	case TFRC_SSTATE_NO_SENT:
-		sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer,
-			       (jiffies +
-				usecs_to_jiffies(TFRC_INITIAL_TIMEOUT)));
-		hctx->ccid3hctx_last_win_count	 = 0;
-		hctx->ccid3hctx_t_last_win_count = now;
+	if (hc->tx_state == TFRC_SSTATE_NO_SENT) {
+		sk_reset_timer(sk, &hc->tx_no_feedback_timer, (jiffies +
+			       usecs_to_jiffies(TFRC_INITIAL_TIMEOUT)));
+		hc->tx_last_win_count	= 0;
+		hc->tx_t_last_win_count = now;
 
 		/* Set t_0 for initial packet */
-		hctx->ccid3hctx_t_nom = now;
+		hc->tx_t_nom = now;
 
-		hctx->ccid3hctx_s = skb->len;
+		hc->tx_s = skb->len;
 
 		/*
 		 * Use initial RTT sample when available: recommended by erratum
@@ -330,123 +310,108 @@ static int ccid3_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb)
 		 */
 		if (dp->dccps_syn_rtt) {
 			ccid3_pr_debug("SYN RTT = %uus\n", dp->dccps_syn_rtt);
-			hctx->ccid3hctx_rtt  = dp->dccps_syn_rtt;
-			hctx->ccid3hctx_x    = rfc3390_initial_rate(sk);
-			hctx->ccid3hctx_t_ld = now;
+			hc->tx_rtt  = dp->dccps_syn_rtt;
+			hc->tx_x    = rfc3390_initial_rate(sk);
+			hc->tx_t_ld = now;
 		} else {
-			/* Sender does not have RTT sample: X_pps = 1 pkt/sec */
-			hctx->ccid3hctx_x = hctx->ccid3hctx_s;
-			hctx->ccid3hctx_x <<= 6;
+			/*
+			 * Sender does not have RTT sample:
+			 * - set fallback RTT (RFC 4340, 3.4) since a RTT value
+			 *   is needed in several parts (e.g.  window counter);
+			 * - set sending rate X_pps = 1pps as per RFC 3448, 4.2.
+			 */
+			hc->tx_rtt = DCCP_FALLBACK_RTT;
+			hc->tx_x   = hc->tx_s;
+			hc->tx_x <<= 6;
 		}
-		ccid3_update_send_interval(hctx);
+		ccid3_update_send_interval(hc);
 
 		ccid3_hc_tx_set_state(sk, TFRC_SSTATE_NO_FBACK);
-		break;
-	case TFRC_SSTATE_NO_FBACK:
-	case TFRC_SSTATE_FBACK:
-		delay = ktime_us_delta(hctx->ccid3hctx_t_nom, now);
+
+	} else {
+		delay = ktime_us_delta(hc->tx_t_nom, now);
 		ccid3_pr_debug("delay=%ld\n", (long)delay);
 		/*
-		 *	Scheduling of packet transmissions [RFC 3448, 4.6]
+		 *	Scheduling of packet transmissions (RFC 5348, 8.3)
 		 *
 		 * if (t_now > t_nom - delta)
 		 *       // send the packet now
 		 * else
 		 *       // send the packet in (t_nom - t_now) milliseconds.
 		 */
-		if (delay - (s64)hctx->ccid3hctx_delta >= 1000)
-			return (u32)delay / 1000L;
+		if (delay >= TFRC_T_DELTA)
+			return (u32)delay / USEC_PER_MSEC;
 
-		ccid3_hc_tx_update_win_count(hctx, now);
-		break;
-	case TFRC_SSTATE_TERM:
-		DCCP_BUG("%s(%p) - Illegal state TERM", dccp_role(sk), sk);
-		return -EINVAL;
+		ccid3_hc_tx_update_win_count(hc, now);
 	}
 
 	/* prepare to send now (add options etc.) */
 	dp->dccps_hc_tx_insert_options = 1;
-	DCCP_SKB_CB(skb)->dccpd_ccval = hctx->ccid3hctx_last_win_count;
+	DCCP_SKB_CB(skb)->dccpd_ccval  = hc->tx_last_win_count;
 
 	/* set the nominal send time for the next following packet */
-	hctx->ccid3hctx_t_nom = ktime_add_us(hctx->ccid3hctx_t_nom,
-					     hctx->ccid3hctx_t_ipi);
-	return 0;
+	hc->tx_t_nom = ktime_add_us(hc->tx_t_nom, hc->tx_t_ipi);
+	return CCID_PACKET_SEND_AT_ONCE;
 }
 
-static void ccid3_hc_tx_packet_sent(struct sock *sk, int more,
-				    unsigned int len)
+static void ccid3_hc_tx_packet_sent(struct sock *sk, unsigned int len)
 {
-	struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
+	struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk);
 
-	ccid3_hc_tx_update_s(hctx, len);
+	ccid3_hc_tx_update_s(hc, len);
 
-	if (tfrc_tx_hist_add(&hctx->ccid3hctx_hist, dccp_sk(sk)->dccps_gss))
+	if (tfrc_tx_hist_add(&hc->tx_hist, dccp_sk(sk)->dccps_gss))
 		DCCP_CRIT("packet history - out of memory!");
 }
 
 static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb)
 {
-	struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
-	struct ccid3_options_received *opt_recv;
+	struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk);
+	struct tfrc_tx_hist_entry *acked;
 	ktime_t now;
 	unsigned long t_nfb;
-	u32 pinv, r_sample;
+	u32 r_sample;
 
 	/* we are only interested in ACKs */
 	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();
-
-	/* 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);
+	/*
+	 * Locate the acknowledged packet in the TX history.
+	 *
+	 * Returning "entry not found" here can for instance happen when
+	 *  - the host has not sent out anything (e.g. a passive server),
+	 *  - the Ack is outdated (packet with higher Ack number was received),
+	 *  - it is a bogus Ack (for a packet not sent on this connection).
+	 */
+	acked = tfrc_tx_hist_find_entry(hc->tx_hist, dccp_hdr_ack_seq(skb));
+	if (acked == NULL)
 		return;
-	}
+	/* For the sake of RTT sampling, ignore/remove all older entries */
+	tfrc_tx_hist_purge(&acked->next);
 
-	/* Update receive rate in units of 64 * bytes/second */
-	hctx->ccid3hctx_x_recv = opt_recv->ccid3or_receive_rate;
-	hctx->ccid3hctx_x_recv <<= 6;
+	/* Update the moving average for the RTT estimate (RFC 3448, 4.3) */
+	now	  = ktime_get_real();
+	r_sample  = dccp_sample_rtt(sk, ktime_us_delta(now, acked->stamp));
+	hc->tx_rtt = tfrc_ewma(hc->tx_rtt, r_sample, 9);
 
-	/* 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 = 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) {
+	if (hc->tx_state == TFRC_SSTATE_NO_FBACK) {
 		ccid3_hc_tx_set_state(sk, TFRC_SSTATE_FBACK);
 
-		if (hctx->ccid3hctx_t_rto == 0) {
+		if (hc->tx_t_rto == 0) {
 			/*
 			 * Initial feedback packet: Larger Initial Windows (4.2)
 			 */
-			hctx->ccid3hctx_x    = rfc3390_initial_rate(sk);
-			hctx->ccid3hctx_t_ld = now;
+			hc->tx_x    = rfc3390_initial_rate(sk);
+			hc->tx_t_ld = now;
 
-			ccid3_update_send_interval(hctx);
+			ccid3_update_send_interval(hc);
 
 			goto done_computing_x;
-		} else if (hctx->ccid3hctx_p == 0) {
+		} else if (hc->tx_p == 0) {
 			/*
 			 * First feedback after nofeedback timer expiry (4.3)
 			 */
@@ -455,25 +420,20 @@ static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb)
 	}
 
 	/* 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);
+	if (hc->tx_p > 0)
+		hc->tx_x_calc = tfrc_calc_x(hc->tx_s, hc->tx_rtt, hc->tx_p);
 	ccid3_hc_tx_update_x(sk, &now);
 
 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,
-			       hctx->ccid3hctx_s, hctx->ccid3hctx_p,
-			       hctx->ccid3hctx_x_calc,
-			       (unsigned)(hctx->ccid3hctx_x_recv >> 6),
-			       (unsigned)(hctx->ccid3hctx_x >> 6));
+			       dccp_role(sk), sk, hc->tx_rtt, r_sample,
+			       hc->tx_s, hc->tx_p, hc->tx_x_calc,
+			       (unsigned int)(hc->tx_x_recv >> 6),
+			       (unsigned int)(hc->tx_x >> 6));
 
 	/* unschedule no feedback timer */
-	sk_stop_timer(sk, &hctx->ccid3hctx_no_feedback_timer);
+	sk_stop_timer(sk, &hc->tx_no_feedback_timer);
 
 	/*
 	 * As we have calculated new ipi, delta, t_nom it is possible
@@ -482,143 +442,109 @@ done_computing_x:
 	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.
+	 * Update timeout interval for the nofeedback timer. In order to control
+	 * rate halving on networks with very low RTTs (<= 1 ms), use per-route
+	 * tunable RTAX_RTO_MIN value as the lower bound.
 	 */
-	hctx->ccid3hctx_t_rto = max_t(u32, 4 * hctx->ccid3hctx_rtt,
-					   (CONFIG_IP_DCCP_CCID3_RTO *
-					    (USEC_PER_SEC / 1000)));
+	hc->tx_t_rto = max_t(u32, 4 * hc->tx_rtt,
+				  USEC_PER_SEC/HZ * tcp_rto_min(sk));
 	/*
 	 * 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);
+	t_nfb = max(hc->tx_t_rto, 2 * hc->tx_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);
+		       dccp_role(sk), sk, usecs_to_jiffies(t_nfb), t_nfb);
 
-	sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer,
+	sk_reset_timer(sk, &hc->tx_no_feedback_timer,
 			   jiffies + usecs_to_jiffies(t_nfb));
 }
 
-static int ccid3_hc_tx_parse_options(struct sock *sk, unsigned char option,
-				     unsigned char len, u16 idx,
-				     unsigned char *value)
+static int ccid3_hc_tx_parse_options(struct sock *sk, u8 packet_type,
+				     u8 option, u8 *optval, u8 optlen)
 {
-	int rc = 0;
-	const struct dccp_sock *dp = dccp_sk(sk);
-	struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
-	struct ccid3_options_received *opt_recv;
+	struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk);
 	__be32 opt_val;
 
-	opt_recv = &hctx->ccid3hctx_options_received;
-
-	if (opt_recv->ccid3or_seqno != dp->dccps_gsr) {
-		opt_recv->ccid3or_seqno		     = dp->dccps_gsr;
-		opt_recv->ccid3or_loss_event_rate    = ~0;
-		opt_recv->ccid3or_loss_intervals_idx = 0;
-		opt_recv->ccid3or_loss_intervals_len = 0;
-		opt_recv->ccid3or_receive_rate	     = 0;
-	}
-
 	switch (option) {
+	case TFRC_OPT_RECEIVE_RATE:
 	case TFRC_OPT_LOSS_EVENT_RATE:
-		if (unlikely(len != 4)) {
-			DCCP_WARN("%s(%p), invalid len %d "
-				  "for TFRC_OPT_LOSS_EVENT_RATE\n",
-				  dccp_role(sk), sk, len);
-			rc = -EINVAL;
-		} else {
-			opt_val = get_unaligned((__be32 *)value);
-			opt_recv->ccid3or_loss_event_rate = ntohl(opt_val);
-			ccid3_pr_debug("%s(%p), LOSS_EVENT_RATE=%u\n",
-				       dccp_role(sk), sk,
-				       opt_recv->ccid3or_loss_event_rate);
+		/* Must be ignored on Data packets, cf. RFC 4342 8.3 and 8.5 */
+		if (packet_type == DCCP_PKT_DATA)
+			break;
+		if (unlikely(optlen != 4)) {
+			DCCP_WARN("%s(%p), invalid len %d for %u\n",
+				  dccp_role(sk), sk, optlen, option);
+			return -EINVAL;
 		}
-		break;
-	case TFRC_OPT_LOSS_INTERVALS:
-		opt_recv->ccid3or_loss_intervals_idx = idx;
-		opt_recv->ccid3or_loss_intervals_len = len;
-		ccid3_pr_debug("%s(%p), LOSS_INTERVALS=(%u, %u)\n",
-			       dccp_role(sk), sk,
-			       opt_recv->ccid3or_loss_intervals_idx,
-			       opt_recv->ccid3or_loss_intervals_len);
-		break;
-	case TFRC_OPT_RECEIVE_RATE:
-		if (unlikely(len != 4)) {
-			DCCP_WARN("%s(%p), invalid len %d "
-				  "for TFRC_OPT_RECEIVE_RATE\n",
-				  dccp_role(sk), sk, len);
-			rc = -EINVAL;
-		} else {
-			opt_val = get_unaligned((__be32 *)value);
-			opt_recv->ccid3or_receive_rate = ntohl(opt_val);
+		opt_val = ntohl(get_unaligned((__be32 *)optval));
+
+		if (option == TFRC_OPT_RECEIVE_RATE) {
+			/* Receive Rate is kept in units of 64 bytes/second */
+			hc->tx_x_recv = opt_val;
+			hc->tx_x_recv <<= 6;
+
 			ccid3_pr_debug("%s(%p), RECEIVE_RATE=%u\n",
-				       dccp_role(sk), sk,
-				       opt_recv->ccid3or_receive_rate);
+				       dccp_role(sk), sk, opt_val);
+		} else {
+			/* Update the fixpoint Loss Event Rate fraction */
+			hc->tx_p = tfrc_invert_loss_event_rate(opt_val);
+
+			ccid3_pr_debug("%s(%p), LOSS_EVENT_RATE=%u\n",
+				       dccp_role(sk), sk, opt_val);
 		}
-		break;
 	}
-
-	return rc;
+	return 0;
 }
 
 static int ccid3_hc_tx_init(struct ccid *ccid, struct sock *sk)
 {
-	struct ccid3_hc_tx_sock *hctx = ccid_priv(ccid);
+	struct ccid3_hc_tx_sock *hc = ccid_priv(ccid);
 
-	hctx->ccid3hctx_state = TFRC_SSTATE_NO_SENT;
-	hctx->ccid3hctx_hist = NULL;
-	setup_timer(&hctx->ccid3hctx_no_feedback_timer,
+	hc->tx_state = TFRC_SSTATE_NO_SENT;
+	hc->tx_hist  = NULL;
+	setup_timer(&hc->tx_no_feedback_timer,
 			ccid3_hc_tx_no_feedback_timer, (unsigned long)sk);
-
 	return 0;
 }
 
 static void ccid3_hc_tx_exit(struct sock *sk)
 {
-	struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
-
-	ccid3_hc_tx_set_state(sk, TFRC_SSTATE_TERM);
-	sk_stop_timer(sk, &hctx->ccid3hctx_no_feedback_timer);
+	struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk);
 
-	tfrc_tx_hist_purge(&hctx->ccid3hctx_hist);
+	sk_stop_timer(sk, &hc->tx_no_feedback_timer);
+	tfrc_tx_hist_purge(&hc->tx_hist);
 }
 
 static void ccid3_hc_tx_get_info(struct sock *sk, struct tcp_info *info)
 {
-	struct ccid3_hc_tx_sock *hctx;
-
-	/* Listen socks doesn't have a private CCID block */
-	if (sk->sk_state == DCCP_LISTEN)
-		return;
-
-	hctx = ccid3_hc_tx_sk(sk);
-	info->tcpi_rto = hctx->ccid3hctx_t_rto;
-	info->tcpi_rtt = hctx->ccid3hctx_rtt;
+	info->tcpi_rto = ccid3_hc_tx_sk(sk)->tx_t_rto;
+	info->tcpi_rtt = ccid3_hc_tx_sk(sk)->tx_rtt;
 }
 
 static int ccid3_hc_tx_getsockopt(struct sock *sk, const int optname, int len,
 				  u32 __user *optval, int __user *optlen)
 {
-	const struct ccid3_hc_tx_sock *hctx;
+	const struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk);
+	struct tfrc_tx_info tfrc;
 	const void *val;
 
-	/* Listen socks doesn't have a private CCID block */
-	if (sk->sk_state == DCCP_LISTEN)
-		return -EINVAL;
-
-	hctx = ccid3_hc_tx_sk(sk);
 	switch (optname) {
 	case DCCP_SOCKOPT_CCID_TX_INFO:
-		if (len < sizeof(hctx->ccid3hctx_tfrc))
+		if (len < sizeof(tfrc))
 			return -EINVAL;
-		len = sizeof(hctx->ccid3hctx_tfrc);
-		val = &hctx->ccid3hctx_tfrc;
+		memset(&tfrc, 0, sizeof(tfrc));
+		tfrc.tfrctx_x	   = hc->tx_x;
+		tfrc.tfrctx_x_recv = hc->tx_x_recv;
+		tfrc.tfrctx_x_calc = hc->tx_x_calc;
+		tfrc.tfrctx_rtt	   = hc->tx_rtt;
+		tfrc.tfrctx_p	   = hc->tx_p;
+		tfrc.tfrctx_rto	   = hc->tx_t_rto;
+		tfrc.tfrctx_ipi	   = hc->tx_t_ipi;
+		len = sizeof(tfrc);
+		val = &tfrc;
 		break;
 	default:
 		return -ENOPROTOOPT;
@@ -645,10 +571,9 @@ enum ccid3_fback_type {
 #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[] = {
+	static const char *const ccid3_rx_state_names[] = {
 	[TFRC_RSTATE_NO_DATA] = "NO_DATA",
 	[TFRC_RSTATE_DATA]    = "DATA",
-	[TFRC_RSTATE_TERM]    = "TERM",
 	};
 
 	return ccid3_rx_state_names[state];
@@ -658,34 +583,29 @@ static const char *ccid3_rx_state_name(enum ccid3_hc_rx_states state)
 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->ccid3hcrx_state;
+	struct ccid3_hc_rx_sock *hc = ccid3_hc_rx_sk(sk);
+	enum ccid3_hc_rx_states oldstate = hc->rx_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->ccid3hcrx_state = state;
+	hc->rx_state = state;
 }
 
 static void ccid3_hc_rx_send_feedback(struct sock *sk,
 				      const struct sk_buff *skb,
 				      enum ccid3_fback_type fbtype)
 {
-	struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
+	struct ccid3_hc_rx_sock *hc = ccid3_hc_rx_sk(sk);
 	struct dccp_sock *dp = dccp_sk(sk);
-	ktime_t now;
+	ktime_t now = ktime_get_real();
 	s64 delta = 0;
 
-	if (unlikely(hcrx->ccid3hcrx_state == TFRC_RSTATE_TERM))
-		return;
-
-	now = ktime_get_real();
-
 	switch (fbtype) {
 	case CCID3_FBACK_INITIAL:
-		hcrx->ccid3hcrx_x_recv = 0;
-		hcrx->ccid3hcrx_pinv   = ~0U;   /* see RFC 4342, 8.5 */
+		hc->rx_x_recv = 0;
+		hc->rx_pinv   = ~0U;   /* see RFC 4342, 8.5 */
 		break;
 	case CCID3_FBACK_PARAM_CHANGE:
 		/*
@@ -698,27 +618,26 @@ static void ccid3_hc_rx_send_feedback(struct sock *sk,
 		 * the number of bytes since last feedback.
 		 * This is a safe fallback, since X is bounded above by X_calc.
 		 */
-		if (hcrx->ccid3hcrx_x_recv > 0)
+		if (hc->rx_x_recv > 0)
 			break;
 		/* fall through */
 	case CCID3_FBACK_PERIODIC:
-		delta = ktime_us_delta(now, hcrx->ccid3hcrx_tstamp_last_feedback);
+		delta = ktime_us_delta(now, hc->rx_tstamp_last_feedback);
 		if (delta <= 0)
 			DCCP_BUG("delta (%ld) <= 0", (long)delta);
 		else
-			hcrx->ccid3hcrx_x_recv =
-				scaled_div32(hcrx->ccid3hcrx_bytes_recv, delta);
+			hc->rx_x_recv = scaled_div32(hc->rx_bytes_recv, delta);
 		break;
 	default:
 		return;
 	}
 
 	ccid3_pr_debug("Interval %ldusec, X_recv=%u, 1/p=%u\n", (long)delta,
-		       hcrx->ccid3hcrx_x_recv, hcrx->ccid3hcrx_pinv);
+		       hc->rx_x_recv, hc->rx_pinv);
 
-	hcrx->ccid3hcrx_tstamp_last_feedback = now;
-	hcrx->ccid3hcrx_last_counter	     = dccp_hdr(skb)->dccph_ccval;
-	hcrx->ccid3hcrx_bytes_recv	     = 0;
+	hc->rx_tstamp_last_feedback = now;
+	hc->rx_last_counter	    = dccp_hdr(skb)->dccph_ccval;
+	hc->rx_bytes_recv	    = 0;
 
 	dp->dccps_hc_rx_insert_options = 1;
 	dccp_send_ack(sk);
@@ -726,30 +645,29 @@ static void ccid3_hc_rx_send_feedback(struct sock *sk,
 
 static int ccid3_hc_rx_insert_options(struct sock *sk, struct sk_buff *skb)
 {
-	const struct ccid3_hc_rx_sock *hcrx;
+	const struct ccid3_hc_rx_sock *hc = ccid3_hc_rx_sk(sk);
 	__be32 x_recv, pinv;
 
 	if (!(sk->sk_state == DCCP_OPEN || sk->sk_state == DCCP_PARTOPEN))
 		return 0;
 
-	hcrx = ccid3_hc_rx_sk(sk);
-
 	if (dccp_packet_without_ack(skb))
 		return 0;
 
-	x_recv = htonl(hcrx->ccid3hcrx_x_recv);
-	pinv   = htonl(hcrx->ccid3hcrx_pinv);
+	x_recv = htonl(hc->rx_x_recv);
+	pinv   = htonl(hc->rx_pinv);
 
-	if (dccp_insert_option(sk, skb, TFRC_OPT_LOSS_EVENT_RATE,
+	if (dccp_insert_option(skb, TFRC_OPT_LOSS_EVENT_RATE,
 			       &pinv, sizeof(pinv)) ||
-	    dccp_insert_option(sk, skb, TFRC_OPT_RECEIVE_RATE,
+	    dccp_insert_option(skb, TFRC_OPT_RECEIVE_RATE,
 			       &x_recv, sizeof(x_recv)))
 		return -1;
 
 	return 0;
 }
 
-/** ccid3_first_li  -  Implements [RFC 3448, 6.3.1]
+/**
+ * ccid3_first_li  -  Implements [RFC 5348, 6.3.1]
  *
  * Determine the length of the first loss interval via inverse lookup.
  * Assume that X_recv can be computed by the throughput equation
@@ -760,26 +678,27 @@ static int ccid3_hc_rx_insert_options(struct sock *sk, struct sk_buff *skb)
  */
 static u32 ccid3_first_li(struct sock *sk)
 {
-	struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
+	struct ccid3_hc_rx_sock *hc = ccid3_hc_rx_sk(sk);
 	u32 x_recv, p, delta;
 	u64 fval;
 
-	if (hcrx->ccid3hcrx_rtt == 0) {
+	if (hc->rx_rtt == 0) {
 		DCCP_WARN("No RTT estimate available, using fallback RTT\n");
-		hcrx->ccid3hcrx_rtt = DCCP_FALLBACK_RTT;
+		hc->rx_rtt = DCCP_FALLBACK_RTT;
 	}
 
-	delta = ktime_to_us(net_timedelta(hcrx->ccid3hcrx_tstamp_last_feedback));
-	x_recv = scaled_div32(hcrx->ccid3hcrx_bytes_recv, delta);
+	delta  = ktime_to_us(net_timedelta(hc->rx_tstamp_last_feedback));
+	x_recv = scaled_div32(hc->rx_bytes_recv, delta);
 	if (x_recv == 0) {		/* would also trigger divide-by-zero */
 		DCCP_WARN("X_recv==0\n");
-		if ((x_recv = hcrx->ccid3hcrx_x_recv) == 0) {
+		if (hc->rx_x_recv == 0) {
 			DCCP_BUG("stored value of X_recv is zero");
 			return ~0U;
 		}
+		x_recv = hc->rx_x_recv;
 	}
 
-	fval = scaled_div(hcrx->ccid3hcrx_s, hcrx->ccid3hcrx_rtt);
+	fval = scaled_div(hc->rx_s, hc->rx_rtt);
 	fval = scaled_div32(fval, x_recv);
 	p = tfrc_calc_x_reverse_lookup(fval);
 
@@ -791,19 +710,19 @@ static u32 ccid3_first_li(struct sock *sk)
 
 static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb)
 {
-	struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
+	struct ccid3_hc_rx_sock *hc = ccid3_hc_rx_sk(sk);
 	enum ccid3_fback_type do_feedback = CCID3_FBACK_NONE;
-	const u32 ndp = dccp_sk(sk)->dccps_options_received.dccpor_ndp;
+	const u64 ndp = dccp_sk(sk)->dccps_options_received.dccpor_ndp;
 	const bool is_data_packet = dccp_data_packet(skb);
 
-	if (unlikely(hcrx->ccid3hcrx_state == TFRC_RSTATE_NO_DATA)) {
+	if (unlikely(hc->rx_state == TFRC_RSTATE_NO_DATA)) {
 		if (is_data_packet) {
 			const u32 payload = skb->len - dccp_hdr(skb)->dccph_doff * 4;
 			do_feedback = CCID3_FBACK_INITIAL;
 			ccid3_hc_rx_set_state(sk, TFRC_RSTATE_DATA);
-			hcrx->ccid3hcrx_s = payload;
+			hc->rx_s = payload;
 			/*
-			 * Not necessary to update ccid3hcrx_bytes_recv here,
+			 * Not necessary to update rx_bytes_recv here,
 			 * since X_recv = 0 for the first feedback packet (cf.
 			 * RFC 3448, 6.3) -- gerrit
 			 */
@@ -811,7 +730,7 @@ static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb)
 		goto update_records;
 	}
 
-	if (tfrc_rx_hist_duplicate(&hcrx->ccid3hcrx_hist, skb))
+	if (tfrc_rx_hist_duplicate(&hc->rx_hist, skb))
 		return; /* done receiving */
 
 	if (is_data_packet) {
@@ -819,23 +738,21 @@ static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb)
 		/*
 		 * Update moving-average of s and the sum of received payload bytes
 		 */
-		hcrx->ccid3hcrx_s = tfrc_ewma(hcrx->ccid3hcrx_s, payload, 9);
-		hcrx->ccid3hcrx_bytes_recv += payload;
+		hc->rx_s = tfrc_ewma(hc->rx_s, payload, 9);
+		hc->rx_bytes_recv += payload;
 	}
 
 	/*
-	 * Handle pending losses and otherwise check for new loss
+	 * Perform loss detection and handle pending losses
 	 */
-	if (tfrc_rx_hist_loss_pending(&hcrx->ccid3hcrx_hist) &&
-	    tfrc_rx_handle_loss(&hcrx->ccid3hcrx_hist,
-				&hcrx->ccid3hcrx_li_hist,
-				skb, ndp, ccid3_first_li, sk) ) {
+	if (tfrc_rx_handle_loss(&hc->rx_hist, &hc->rx_li_hist,
+				skb, ndp, ccid3_first_li, sk)) {
 		do_feedback = CCID3_FBACK_PARAM_CHANGE;
 		goto done_receiving;
 	}
 
-	if (tfrc_rx_hist_new_loss_indicated(&hcrx->ccid3hcrx_hist, skb, ndp))
-		goto update_records;
+	if (tfrc_rx_hist_loss_pending(&hc->rx_hist))
+		return; /* done receiving */
 
 	/*
 	 * Handle data packets: RTT sampling and monitoring p
@@ -843,17 +760,17 @@ static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb)
 	if (unlikely(!is_data_packet))
 		goto update_records;
 
-	if (!tfrc_lh_is_initialised(&hcrx->ccid3hcrx_li_hist)) {
-		const u32 sample = tfrc_rx_hist_sample_rtt(&hcrx->ccid3hcrx_hist, skb);
+	if (!tfrc_lh_is_initialised(&hc->rx_li_hist)) {
+		const u32 sample = tfrc_rx_hist_sample_rtt(&hc->rx_hist, skb);
 		/*
 		 * Empty loss history: no loss so far, hence p stays 0.
 		 * Sample RTT values, since an RTT estimate is required for the
 		 * computation of p when the first loss occurs; RFC 3448, 6.3.1.
 		 */
 		if (sample != 0)
-			hcrx->ccid3hcrx_rtt = tfrc_ewma(hcrx->ccid3hcrx_rtt, sample, 9);
+			hc->rx_rtt = tfrc_ewma(hc->rx_rtt, sample, 9);
 
-	} else if (tfrc_lh_update_i_mean(&hcrx->ccid3hcrx_li_hist, skb)) {
+	} else if (tfrc_lh_update_i_mean(&hc->rx_li_hist, skb)) {
 		/*
 		 * Step (3) of [RFC 3448, 6.1]: Recompute I_mean and, if I_mean
 		 * has decreased (resp. p has increased), send feedback now.
@@ -864,11 +781,11 @@ static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb)
 	/*
 	 * Check if the periodic once-per-RTT feedback is due; RFC 4342, 10.3
 	 */
-	if (SUB16(dccp_hdr(skb)->dccph_ccval, hcrx->ccid3hcrx_last_counter) > 3)
+	if (SUB16(dccp_hdr(skb)->dccph_ccval, hc->rx_last_counter) > 3)
 		do_feedback = CCID3_FBACK_PERIODIC;
 
 update_records:
-	tfrc_rx_hist_add_packet(&hcrx->ccid3hcrx_hist, skb, ndp);
+	tfrc_rx_hist_add_packet(&hc->rx_hist, skb, ndp);
 
 done_receiving:
 	if (do_feedback)
@@ -877,57 +794,42 @@ done_receiving:
 
 static int ccid3_hc_rx_init(struct ccid *ccid, struct sock *sk)
 {
-	struct ccid3_hc_rx_sock *hcrx = ccid_priv(ccid);
+	struct ccid3_hc_rx_sock *hc = ccid_priv(ccid);
 
-	hcrx->ccid3hcrx_state = TFRC_RSTATE_NO_DATA;
-	tfrc_lh_init(&hcrx->ccid3hcrx_li_hist);
-	return tfrc_rx_hist_alloc(&hcrx->ccid3hcrx_hist);
+	hc->rx_state = TFRC_RSTATE_NO_DATA;
+	tfrc_lh_init(&hc->rx_li_hist);
+	return tfrc_rx_hist_alloc(&hc->rx_hist);
 }
 
 static void ccid3_hc_rx_exit(struct sock *sk)
 {
-	struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
+	struct ccid3_hc_rx_sock *hc = ccid3_hc_rx_sk(sk);
 
-	ccid3_hc_rx_set_state(sk, TFRC_RSTATE_TERM);
-
-	tfrc_rx_hist_purge(&hcrx->ccid3hcrx_hist);
-	tfrc_lh_cleanup(&hcrx->ccid3hcrx_li_hist);
+	tfrc_rx_hist_purge(&hc->rx_hist);
+	tfrc_lh_cleanup(&hc->rx_li_hist);
 }
 
 static void ccid3_hc_rx_get_info(struct sock *sk, struct tcp_info *info)
 {
-	const struct ccid3_hc_rx_sock *hcrx;
-
-	/* Listen socks doesn't have a private CCID block */
-	if (sk->sk_state == DCCP_LISTEN)
-		return;
-
-	hcrx = ccid3_hc_rx_sk(sk);
-	info->tcpi_ca_state = hcrx->ccid3hcrx_state;
+	info->tcpi_ca_state = ccid3_hc_rx_sk(sk)->rx_state;
 	info->tcpi_options  |= TCPI_OPT_TIMESTAMPS;
-	info->tcpi_rcv_rtt  = hcrx->ccid3hcrx_rtt;
+	info->tcpi_rcv_rtt  = ccid3_hc_rx_sk(sk)->rx_rtt;
 }
 
 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;
+	const struct ccid3_hc_rx_sock *hc = ccid3_hc_rx_sk(sk);
 	struct tfrc_rx_info rx_info;
 	const void *val;
 
-	/* Listen socks doesn't have a private CCID block */
-	if (sk->sk_state == DCCP_LISTEN)
-		return -EINVAL;
-
-	hcrx = ccid3_hc_rx_sk(sk);
 	switch (optname) {
 	case DCCP_SOCKOPT_CCID_RX_INFO:
 		if (len < sizeof(rx_info))
 			return -EINVAL;
-		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);
+		rx_info.tfrcrx_x_recv = hc->rx_x_recv;
+		rx_info.tfrcrx_rtt    = hc->rx_rtt;
+		rx_info.tfrcrx_p      = tfrc_invert_loss_event_rate(hc->rx_pinv);
 		len = sizeof(rx_info);
 		val = &rx_info;
 		break;
@@ -941,10 +843,9 @@ static int ccid3_hc_rx_getsockopt(struct sock *sk, const int optname, int len,
 	return 0;
 }
 
-static struct ccid_operations ccid3 = {
+struct ccid_operations ccid3_ops = {
 	.ccid_id		   = DCCPC_CCID3,
 	.ccid_name		   = "TCP-Friendly Rate Control",
-	.ccid_owner		   = THIS_MODULE,
 	.ccid_hc_tx_obj_size	   = sizeof(struct ccid3_hc_tx_sock),
 	.ccid_hc_tx_init	   = ccid3_hc_tx_init,
 	.ccid_hc_tx_exit	   = ccid3_hc_tx_exit,
@@ -964,24 +865,6 @@ static struct ccid_operations ccid3 = {
 };
 
 #ifdef CONFIG_IP_DCCP_CCID3_DEBUG
-module_param(ccid3_debug, bool, 0444);
-MODULE_PARM_DESC(ccid3_debug, "Enable debug messages");
+module_param(ccid3_debug, bool, 0644);
+MODULE_PARM_DESC(ccid3_debug, "Enable CCID-3 debug messages");
 #endif
-
-static __init int ccid3_module_init(void)
-{
-	return ccid_register(&ccid3);
-}
-module_init(ccid3_module_init);
-
-static __exit void ccid3_module_exit(void)
-{
-	ccid_unregister(&ccid3);
-}
-module_exit(ccid3_module_exit);
-
-MODULE_AUTHOR("Ian McDonald <ian.mcdonald@jandi.co.nz>, "
-	      "Arnaldo Carvalho de Melo <acme@ghostprotocols.net>");
-MODULE_DESCRIPTION("DCCP TFRC CCID3 CCID");
-MODULE_LICENSE("GPL");
-MODULE_ALIAS("net-dccp-ccid-3");