Merge /spare/repo/linux-2.6/

1 files changed, 1214 insertions, 0 deletions

diff --git a/net/dccp/ccids/ccid3.c b/net/dccp/ccids/ccid3.c
new file mode 100644
index 000000000000..38aa84986118
--- /dev/null
+++ b/net/dccp/ccids/ccid3.c
@@ -0,0 +1,1214 @@
+/*
+ *  net/dccp/ccids/ccid3.c
+ *
+ *  Copyright (c) 2005 The University of Waikato, Hamilton, New Zealand.
+ *  Copyright (c) 2005 Ian McDonald <iam4@cs.waikato.ac.nz>
+ *
+ *  An implementation of the DCCP protocol
+ *
+ *  This code has been developed by the University of Waikato WAND
+ *  research group. For further information please see http://www.wand.net.nz/
+ *
+ *  This code also uses code from Lulea University, rereleased as GPL by its
+ *  authors:
+ *  Copyright (c) 2003 Nils-Erik Mattsson, Joacim Haggmark, Magnus Erixzon
+ *
+ *  Changes to meet Linux coding standards, to make it meet latest ccid3 draft
+ *  and to make it work as a loadable module in the DCCP stack written by
+ *  Arnaldo Carvalho de Melo <acme@conectiva.com.br>.
+ *
+ *  Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/config.h>
+#include "../ccid.h"
+#include "../dccp.h"
+#include "lib/packet_history.h"
+#include "lib/loss_interval.h"
+#include "lib/tfrc.h"
+#include "ccid3.h"
+
+/*
+ * Reason for maths here is to avoid 32 bit overflow when a is big.
+ * With this we get close to the limit.
+ */
+static inline u32 usecs_div(const u32 a, const u32 b)
+{
+	const u32 div = a < (UINT_MAX / (USEC_PER_SEC /    10)) ?    10 :
+			a < (UINT_MAX / (USEC_PER_SEC /    50)) ?    50 :
+			a < (UINT_MAX / (USEC_PER_SEC /   100)) ?   100 :
+			a < (UINT_MAX / (USEC_PER_SEC /   500)) ?   500 :
+			a < (UINT_MAX / (USEC_PER_SEC /  1000)) ?  1000 :
+			a < (UINT_MAX / (USEC_PER_SEC /  5000)) ?  5000 :
+			a < (UINT_MAX / (USEC_PER_SEC / 10000)) ? 10000 :
+			a < (UINT_MAX / (USEC_PER_SEC / 50000)) ? 50000 :
+								 100000;
+	const u32 tmp = a * (USEC_PER_SEC / div);
+	return (b >= 2 * div) ? tmp / (b / div) : tmp;
+}
+
+static int ccid3_debug;
+
+#ifdef CCID3_DEBUG
+#define ccid3_pr_debug(format, a...) \
+	do { if (ccid3_debug) \
+		printk(KERN_DEBUG "%s: " format, __FUNCTION__, ##a); \
+	} while (0)
+#else
+#define ccid3_pr_debug(format, a...)
+#endif
+
+static struct dccp_tx_hist *ccid3_tx_hist;
+static struct dccp_rx_hist *ccid3_rx_hist;
+static struct dccp_li_hist *ccid3_li_hist;
+
+static int ccid3_init(struct sock *sk)
+{
+	return 0;
+}
+
+static void ccid3_exit(struct sock *sk)
+{
+}
+
+/* TFRC sender states */
+enum ccid3_hc_tx_states {
+       	TFRC_SSTATE_NO_SENT = 1,
+	TFRC_SSTATE_NO_FBACK,
+	TFRC_SSTATE_FBACK,
+	TFRC_SSTATE_TERM,
+};
+
+#ifdef CCID3_DEBUG
+static const char *ccid3_tx_state_name(enum ccid3_hc_tx_states state)
+{
+	static char *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];
+}
+#endif
+
+static inline 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;
+
+	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;
+}
+
+/* Calculate new t_ipi (inter packet interval) by t_ipi = s / X_inst */
+static inline void ccid3_calc_new_t_ipi(struct ccid3_hc_tx_sock *hctx)
+{
+	/*
+	 * If no feedback spec says t_ipi is 1 second (set elsewhere and then
+	 * doubles after every no feedback timer (separate function)
+	 */
+	if (hctx->ccid3hctx_state != TFRC_SSTATE_NO_FBACK)
+		hctx->ccid3hctx_t_ipi = usecs_div(hctx->ccid3hctx_s,
+						  hctx->ccid3hctx_x);
+}
+
+/* Calculate new delta by delta = min(t_ipi / 2, t_gran / 2) */
+static inline void ccid3_calc_new_delta(struct ccid3_hc_tx_sock *hctx)
+{
+	hctx->ccid3hctx_delta = min_t(u32, hctx->ccid3hctx_t_ipi / 2,
+					   TFRC_OPSYS_HALF_TIME_GRAN);
+}
+
+/*
+ * Update X by
+ *    If (p > 0)
+ *       x_calc = calcX(s, R, p);
+ *       X = max(min(X_calc, 2 * X_recv), s / t_mbi);
+ *    Else
+ *       If (now - tld >= R)
+ *          X = max(min(2 * X, 2 * X_recv), s / R);
+ *          tld = now;
+ */ 
+static void ccid3_hc_tx_update_x(struct sock *sk)
+{
+	struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
+
+	/* To avoid large error in calcX */
+	if (hctx->ccid3hctx_p >= TFRC_SMALLEST_P) {
+		hctx->ccid3hctx_x_calc = tfrc_calc_x(hctx->ccid3hctx_s,
+						     hctx->ccid3hctx_rtt,
+						     hctx->ccid3hctx_p);
+		hctx->ccid3hctx_x = max_t(u32, min_t(u32, hctx->ccid3hctx_x_calc,
+							  2 * hctx->ccid3hctx_x_recv),
+					       (hctx->ccid3hctx_s /
+					        TFRC_MAX_BACK_OFF_TIME));
+	} else {
+		struct timeval now;
+
+		dccp_timestamp(sk, &now);
+	       	if (timeval_delta(&now, &hctx->ccid3hctx_t_ld) >=
+		    hctx->ccid3hctx_rtt) {
+			hctx->ccid3hctx_x = max_t(u32, min_t(u32, hctx->ccid3hctx_x_recv,
+								  hctx->ccid3hctx_x) * 2,
+						       usecs_div(hctx->ccid3hctx_s,
+							       	 hctx->ccid3hctx_rtt));
+			hctx->ccid3hctx_t_ld = now;
+		}
+	}
+}
+
+static void ccid3_hc_tx_no_feedback_timer(unsigned long data)
+{
+	struct sock *sk = (struct sock *)data;
+	unsigned long next_tmout = 0;
+	struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
+
+	bh_lock_sock(sk);
+	if (sock_owned_by_user(sk)) {
+		/* Try again later. */
+		/* XXX: set some sensible MIB */
+		sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer,
+			       jiffies + HZ / 5);
+		goto out;
+	}
+
+	ccid3_pr_debug("%s, sk=%p, state=%s\n", dccp_role(sk), sk,
+		       ccid3_tx_state_name(hctx->ccid3hctx_state));
+	
+	switch (hctx->ccid3hctx_state) {
+	case TFRC_SSTATE_TERM:
+		goto out;
+	case TFRC_SSTATE_NO_FBACK:
+		/* Halve send rate */
+		hctx->ccid3hctx_x /= 2;
+		if (hctx->ccid3hctx_x < (hctx->ccid3hctx_s /
+					 TFRC_MAX_BACK_OFF_TIME))
+			hctx->ccid3hctx_x = (hctx->ccid3hctx_s /
+					     TFRC_MAX_BACK_OFF_TIME);
+
+		ccid3_pr_debug("%s, sk=%p, state=%s, updated tx rate to %d "
+			       "bytes/s\n",
+			       dccp_role(sk), sk,
+			       ccid3_tx_state_name(hctx->ccid3hctx_state),
+			       hctx->ccid3hctx_x);
+		next_tmout = max_t(u32, 2 * usecs_div(hctx->ccid3hctx_s,
+						      hctx->ccid3hctx_x),
+					TFRC_INITIAL_TIMEOUT);
+		/*
+		 * FIXME - not sure above calculation is correct. See section
+		 * 5 of CCID3 11 should adjust tx_t_ipi and double that to
+		 * achieve it really
+		 */
+		break;
+	case TFRC_SSTATE_FBACK:
+		/*
+		 * Check if IDLE since last timeout and recv rate is less than
+		 * 4 packets per RTT
+		 */
+		if (!hctx->ccid3hctx_idle ||
+		    (hctx->ccid3hctx_x_recv >=
+		     4 * usecs_div(hctx->ccid3hctx_s, hctx->ccid3hctx_rtt))) {
+			ccid3_pr_debug("%s, sk=%p, state=%s, not idle\n",
+				       dccp_role(sk), sk,
+				       ccid3_tx_state_name(hctx->ccid3hctx_state));
+			/* Halve sending rate */
+
+			/*  If (X_calc > 2 * X_recv)
+			 *    X_recv = max(X_recv / 2, s / (2 * t_mbi));
+			 *  Else
+			 *    X_recv = X_calc / 4;
+			 */
+			BUG_ON(hctx->ccid3hctx_p >= TFRC_SMALLEST_P &&
+			       hctx->ccid3hctx_x_calc == 0);
+
+			/* check also if p is zero -> x_calc is infinity? */
+			if (hctx->ccid3hctx_p < TFRC_SMALLEST_P ||
+			    hctx->ccid3hctx_x_calc > 2 * hctx->ccid3hctx_x_recv)
+				hctx->ccid3hctx_x_recv = max_t(u32, hctx->ccid3hctx_x_recv / 2,
+								    hctx->ccid3hctx_s / (2 * TFRC_MAX_BACK_OFF_TIME));
+			else
+				hctx->ccid3hctx_x_recv = hctx->ccid3hctx_x_calc / 4;
+
+			/* Update sending rate */
+			ccid3_hc_tx_update_x(sk);
+		}
+		/*
+		 * Schedule no feedback timer to expire in
+		 * max(4 * R, 2 * s / X)
+		 */
+		next_tmout = max_t(u32, hctx->ccid3hctx_t_rto, 
+					2 * usecs_div(hctx->ccid3hctx_s,
+						      hctx->ccid3hctx_x));
+		break;
+	default:
+		printk(KERN_CRIT "%s: %s, sk=%p, Illegal state (%d)!\n",
+		       __FUNCTION__, dccp_role(sk), sk, hctx->ccid3hctx_state);
+		dump_stack();
+		goto out;
+	}
+
+	sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer, 
+		      jiffies + max_t(u32, 1, usecs_to_jiffies(next_tmout)));
+	hctx->ccid3hctx_idle = 1;
+out:
+	bh_unlock_sock(sk);
+	sock_put(sk);
+}
+
+static int ccid3_hc_tx_send_packet(struct sock *sk,
+				   struct sk_buff *skb, int len)
+{
+	struct dccp_sock *dp = dccp_sk(sk);
+	struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
+	struct dccp_tx_hist_entry *new_packet;
+	struct timeval now;
+	long delay;
+	int rc = -ENOTCONN;
+
+	BUG_ON(hctx == NULL || hctx->ccid3hctx_state == TFRC_SSTATE_TERM);
+
+	/* Check if pure ACK or Terminating*/
+	/*
+	 * XXX: We only call this function for DATA and DATAACK, on, these
+	 * packets can have zero length, but why the comment about "pure ACK"?
+	 */
+	if (unlikely(len == 0))
+		goto out;
+
+	/* See if last packet allocated was not sent */
+	new_packet = dccp_tx_hist_head(&hctx->ccid3hctx_hist);
+	if (new_packet == NULL || new_packet->dccphtx_sent) {
+		new_packet = dccp_tx_hist_entry_new(ccid3_tx_hist,
+						    SLAB_ATOMIC);
+
+		rc = -ENOBUFS;
+		if (unlikely(new_packet == NULL)) {
+			LIMIT_NETDEBUG(KERN_WARNING "%s: %s, sk=%p, not enough "
+				       "mem to add to history, send refused\n",
+				       __FUNCTION__, dccp_role(sk), sk);
+			goto out;
+		}
+
+		dccp_tx_hist_add_entry(&hctx->ccid3hctx_hist, new_packet);
+	}
+
+	dccp_timestamp(sk, &now);
+
+	switch (hctx->ccid3hctx_state) {
+	case TFRC_SSTATE_NO_SENT:
+		hctx->ccid3hctx_no_feedback_timer.function = ccid3_hc_tx_no_feedback_timer;
+		hctx->ccid3hctx_no_feedback_timer.data     = (unsigned long)sk;
+		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;
+		ccid3_hc_tx_set_state(sk, TFRC_SSTATE_NO_FBACK);
+		hctx->ccid3hctx_t_ipi = TFRC_INITIAL_IPI;
+
+		/* Set nominal send time for initial packet */
+		hctx->ccid3hctx_t_nom = now;
+		timeval_add_usecs(&hctx->ccid3hctx_t_nom,
+				  hctx->ccid3hctx_t_ipi);
+		ccid3_calc_new_delta(hctx);
+		rc = 0;
+		break;
+	case TFRC_SSTATE_NO_FBACK:
+	case TFRC_SSTATE_FBACK:
+		delay = (timeval_delta(&now, &hctx->ccid3hctx_t_nom) -
+		         hctx->ccid3hctx_delta);
+		delay /= -1000;
+		/* divide by -1000 is to convert to ms and get sign right */
+		rc = delay > 0 ? delay : 0;
+		break;
+	default:
+		printk(KERN_CRIT "%s: %s, sk=%p, Illegal state (%d)!\n",
+		       __FUNCTION__, dccp_role(sk), sk, hctx->ccid3hctx_state);
+		dump_stack();
+		rc = -EINVAL;
+		break;
+	}
+
+	/* Can we send? if so add options and add to packet history */
+	if (rc == 0) {
+		dp->dccps_hc_tx_insert_options = 1;
+		new_packet->dccphtx_ccval =
+			DCCP_SKB_CB(skb)->dccpd_ccval =
+				hctx->ccid3hctx_last_win_count;
+	}
+out:
+	return rc;
+}
+
+static void ccid3_hc_tx_packet_sent(struct sock *sk, int more, int len)
+{
+	const struct dccp_sock *dp = dccp_sk(sk);
+	struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
+	struct timeval now;
+
+	BUG_ON(hctx == NULL || hctx->ccid3hctx_state == TFRC_SSTATE_TERM);
+
+	dccp_timestamp(sk, &now);
+
+	/* check if we have sent a data packet */
+	if (len > 0) {
+		unsigned long quarter_rtt;
+		struct dccp_tx_hist_entry *packet;
+
+		packet = dccp_tx_hist_head(&hctx->ccid3hctx_hist);
+		if (unlikely(packet == NULL)) {
+			LIMIT_NETDEBUG(KERN_WARNING "%s: packet doesn't "
+				       "exists in history!\n", __FUNCTION__);
+			return;
+		}
+		if (unlikely(packet->dccphtx_sent)) {
+			LIMIT_NETDEBUG(KERN_WARNING "%s: no unsent packet in "
+				       "history!\n", __FUNCTION__);
+			return;
+		}
+		packet->dccphtx_tstamp = now;
+		packet->dccphtx_seqno  = dp->dccps_gss;
+		/*
+		 * Check if win_count have changed
+		 * Algorithm in "8.1. Window Counter Valuer" in
+		 * draft-ietf-dccp-ccid3-11.txt
+		 */
+		quarter_rtt = timeval_delta(&now, &hctx->ccid3hctx_t_last_win_count);
+		if (likely(hctx->ccid3hctx_rtt > 8))
+			quarter_rtt /= hctx->ccid3hctx_rtt / 4;
+
+		if (quarter_rtt > 0) {
+			hctx->ccid3hctx_t_last_win_count = now;
+			hctx->ccid3hctx_last_win_count	 = (hctx->ccid3hctx_last_win_count +
+							    min_t(unsigned long, quarter_rtt, 5)) % 16;
+			ccid3_pr_debug("%s, sk=%p, window changed from "
+				       "%u to %u!\n",
+				       dccp_role(sk), sk,
+				       packet->dccphtx_ccval,
+				       hctx->ccid3hctx_last_win_count);
+		}
+
+		hctx->ccid3hctx_idle = 0;
+		packet->dccphtx_rtt  = hctx->ccid3hctx_rtt;
+		packet->dccphtx_sent = 1;
+	} else
+		ccid3_pr_debug("%s, sk=%p, seqno=%llu NOT inserted!\n",
+			       dccp_role(sk), sk, dp->dccps_gss);
+
+	switch (hctx->ccid3hctx_state) {
+	case TFRC_SSTATE_NO_SENT:
+		/* if first wasn't pure ack */
+		if (len != 0)
+			printk(KERN_CRIT "%s: %s, First packet sent is noted "
+					 "as a data packet\n",
+			       __FUNCTION__, dccp_role(sk));
+		return;
+	case TFRC_SSTATE_NO_FBACK:
+	case TFRC_SSTATE_FBACK:
+		if (len > 0) {
+			hctx->ccid3hctx_t_nom = now;
+			ccid3_calc_new_t_ipi(hctx);
+			ccid3_calc_new_delta(hctx);
+			timeval_add_usecs(&hctx->ccid3hctx_t_nom,
+					  hctx->ccid3hctx_t_ipi);
+		}
+		break;
+	default:
+		printk(KERN_CRIT "%s: %s, sk=%p, Illegal state (%d)!\n",
+		       __FUNCTION__, dccp_role(sk), sk, hctx->ccid3hctx_state);
+		dump_stack();
+		break;
+	}
+}
+
+static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb)
+{
+	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 dccp_tx_hist_entry *packet;
+	struct timeval now;
+	unsigned long next_tmout; 
+	u32 t_elapsed;
+	u32 pinv;
+	u32 x_recv;
+	u32 r_sample;
+
+	BUG_ON(hctx == NULL || hctx->ccid3hctx_state == TFRC_SSTATE_TERM);
+
+	/* 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;
+
+	opt_recv = &hctx->ccid3hctx_options_received;
+
+	t_elapsed = dp->dccps_options_received.dccpor_elapsed_time * 10;
+	x_recv = opt_recv->ccid3or_receive_rate;
+	pinv = opt_recv->ccid3or_loss_event_rate;
+
+	switch (hctx->ccid3hctx_state) {
+	case TFRC_SSTATE_NO_SENT:
+		/* FIXME: what to do here? */
+		return;
+	case TFRC_SSTATE_NO_FBACK:
+	case TFRC_SSTATE_FBACK:
+		/* Calculate new round trip sample by
+		 * R_sample = (now - t_recvdata) - t_delay */
+		/* get t_recvdata from history */
+		packet = dccp_tx_hist_find_entry(&hctx->ccid3hctx_hist,
+						 DCCP_SKB_CB(skb)->dccpd_ack_seq);
+		if (unlikely(packet == NULL)) {
+			LIMIT_NETDEBUG(KERN_WARNING "%s: %s, sk=%p, seqno "
+				       "%llu(%s) does't exist in history!\n",
+				       __FUNCTION__, dccp_role(sk), sk,
+			    (unsigned long long)DCCP_SKB_CB(skb)->dccpd_ack_seq,
+				dccp_packet_name(DCCP_SKB_CB(skb)->dccpd_type));
+			return;
+		}
+
+		/* Update RTT */
+		dccp_timestamp(sk, &now);
+		r_sample = timeval_delta(&now, &packet->dccphtx_tstamp);
+		if (unlikely(r_sample <= t_elapsed))
+			LIMIT_NETDEBUG(KERN_WARNING "%s: r_sample=%uus, "
+				       "t_elapsed=%uus\n",
+				       __FUNCTION__, r_sample, t_elapsed);
+		else
+			r_sample -= t_elapsed;
+
+		/* Update RTT estimate by 
+		 * If (No feedback recv)
+		 *    R = R_sample;
+		 * Else
+		 *    R = q * R + (1 - q) * R_sample;
+		 *
+		 * q is a constant, RFC 3448 recomments 0.9
+		 */
+		if (hctx->ccid3hctx_state == TFRC_SSTATE_NO_FBACK) {
+			ccid3_hc_tx_set_state(sk, TFRC_SSTATE_FBACK);
+			hctx->ccid3hctx_rtt = r_sample;
+		} else
+			hctx->ccid3hctx_rtt = (hctx->ccid3hctx_rtt * 9) / 10 +
+					      r_sample / 10;
+
+		ccid3_pr_debug("%s, sk=%p, New RTT estimate=%uus, "
+			       "r_sample=%us\n", dccp_role(sk), sk,
+			       hctx->ccid3hctx_rtt, r_sample);
+
+		/* Update timeout interval */
+		hctx->ccid3hctx_t_rto = max_t(u32, 4 * hctx->ccid3hctx_rtt,
+					      USEC_PER_SEC);
+
+		/* Update receive rate */
+		hctx->ccid3hctx_x_recv = x_recv;/* X_recv in bytes per sec */
+
+		/* Update loss event rate */
+		if (pinv == ~0 || pinv == 0)
+			hctx->ccid3hctx_p = 0;
+		else {
+			hctx->ccid3hctx_p = 1000000 / pinv;
+
+			if (hctx->ccid3hctx_p < TFRC_SMALLEST_P) {
+				hctx->ccid3hctx_p = TFRC_SMALLEST_P;
+				ccid3_pr_debug("%s, sk=%p, Smallest p used!\n",
+					       dccp_role(sk), sk);
+			}
+		}
+
+		/* unschedule no feedback timer */
+		sk_stop_timer(sk, &hctx->ccid3hctx_no_feedback_timer);
+
+		/* Update sending rate */
+		ccid3_hc_tx_update_x(sk);
+
+		/* Update next send time */
+		timeval_sub_usecs(&hctx->ccid3hctx_t_nom,
+				  hctx->ccid3hctx_t_ipi);
+		ccid3_calc_new_t_ipi(hctx);
+		timeval_add_usecs(&hctx->ccid3hctx_t_nom,
+				  hctx->ccid3hctx_t_ipi);
+		ccid3_calc_new_delta(hctx);
+
+		/* remove all packets older than the one acked from history */
+		dccp_tx_hist_purge_older(ccid3_tx_hist,
+					 &hctx->ccid3hctx_hist, packet);
+		/*
+		 * 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_ccids.
+		 */
+		sk->sk_write_space(sk);
+
+		/*
+		 * Schedule no feedback timer to expire in
+		 * max(4 * R, 2 * s / X)
+		 */
+		next_tmout = max(hctx->ccid3hctx_t_rto,
+				 2 * usecs_div(hctx->ccid3hctx_s,
+					       hctx->ccid3hctx_x));
+			
+		ccid3_pr_debug("%s, sk=%p, Scheduled no feedback timer to "
+			       "expire in %lu jiffies (%luus)\n",
+			       dccp_role(sk), sk,
+			       usecs_to_jiffies(next_tmout), next_tmout); 
+
+		sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer, 
+			       jiffies + max_t(u32, 1, usecs_to_jiffies(next_tmout)));
+
+		/* set idle flag */
+		hctx->ccid3hctx_idle = 1;   
+		break;
+	default:
+		printk(KERN_CRIT "%s: %s, sk=%p, Illegal state (%d)!\n",
+		       __FUNCTION__, dccp_role(sk), sk, hctx->ccid3hctx_state);
+		dump_stack();
+		break;
+	}
+}
+
+static void ccid3_hc_tx_insert_options(struct sock *sk, struct sk_buff *skb)
+{
+	const struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
+
+	BUG_ON(hctx == NULL);
+
+	if (!(sk->sk_state == DCCP_OPEN || sk->sk_state == DCCP_PARTOPEN))
+		return;
+
+	 DCCP_SKB_CB(skb)->dccpd_ccval = hctx->ccid3hctx_last_win_count;
+}
+
+static int ccid3_hc_tx_parse_options(struct sock *sk, unsigned char option,
+				     unsigned char len, u16 idx,
+				     unsigned char *value)
+{
+	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;
+
+	BUG_ON(hctx == NULL);
+
+	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_LOSS_EVENT_RATE:
+		if (unlikely(len != 4)) {
+			LIMIT_NETDEBUG(KERN_WARNING "%s: %s, sk=%p, invalid "
+				       "len for TFRC_OPT_LOSS_EVENT_RATE\n",
+				       __FUNCTION__, dccp_role(sk), sk);
+			rc = -EINVAL;
+		} else {
+			opt_recv->ccid3or_loss_event_rate = ntohl(*(u32 *)value);
+			ccid3_pr_debug("%s, sk=%p, LOSS_EVENT_RATE=%u\n",
+				       dccp_role(sk), sk,
+				       opt_recv->ccid3or_loss_event_rate);
+		}
+		break;
+	case TFRC_OPT_LOSS_INTERVALS:
+		opt_recv->ccid3or_loss_intervals_idx = idx;
+		opt_recv->ccid3or_loss_intervals_len = len;
+		ccid3_pr_debug("%s, sk=%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)) {
+			LIMIT_NETDEBUG(KERN_WARNING "%s: %s, sk=%p, invalid "
+				       "len for TFRC_OPT_RECEIVE_RATE\n",
+				       __FUNCTION__, dccp_role(sk), sk);
+			rc = -EINVAL;
+		} else {
+			opt_recv->ccid3or_receive_rate = ntohl(*(u32 *)value);
+			ccid3_pr_debug("%s, sk=%p, RECEIVE_RATE=%u\n",
+				       dccp_role(sk), sk,
+				       opt_recv->ccid3or_receive_rate);
+		}
+		break;
+	}
+
+	return rc;
+}
+
+static int ccid3_hc_tx_init(struct sock *sk)
+{
+	struct dccp_sock *dp = dccp_sk(sk);
+	struct ccid3_hc_tx_sock *hctx;
+
+	dp->dccps_hc_tx_ccid_private = kmalloc(sizeof(*hctx), gfp_any());
+	if (dp->dccps_hc_tx_ccid_private == NULL)
+		return -ENOMEM;
+
+	hctx = ccid3_hc_tx_sk(sk);
+	memset(hctx, 0, sizeof(*hctx));
+
+	if (dp->dccps_packet_size >= TFRC_MIN_PACKET_SIZE &&
+	    dp->dccps_packet_size <= TFRC_MAX_PACKET_SIZE)
+		hctx->ccid3hctx_s = dp->dccps_packet_size;
+	else
+		hctx->ccid3hctx_s = TFRC_STD_PACKET_SIZE;
+
+	/* Set transmission rate to 1 packet per second */
+	hctx->ccid3hctx_x     = hctx->ccid3hctx_s;
+	hctx->ccid3hctx_t_rto = USEC_PER_SEC;
+	hctx->ccid3hctx_state = TFRC_SSTATE_NO_SENT;
+	INIT_LIST_HEAD(&hctx->ccid3hctx_hist);
+	init_timer(&hctx->ccid3hctx_no_feedback_timer);
+
+	return 0;
+}
+
+static void ccid3_hc_tx_exit(struct sock *sk)
+{
+	struct dccp_sock *dp = dccp_sk(sk);
+	struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
+
+	BUG_ON(hctx == NULL);
+
+	ccid3_hc_tx_set_state(sk, TFRC_SSTATE_TERM);
+	sk_stop_timer(sk, &hctx->ccid3hctx_no_feedback_timer);
+
+	/* Empty packet history */
+	dccp_tx_hist_purge(ccid3_tx_hist, &hctx->ccid3hctx_hist);
+
+	kfree(dp->dccps_hc_tx_ccid_private);
+	dp->dccps_hc_tx_ccid_private = NULL;
+}
+
+/*
+ * RX Half Connection methods
+ */
+
+/* TFRC receiver states */
+enum ccid3_hc_rx_states {
+       	TFRC_RSTATE_NO_DATA = 1,
+	TFRC_RSTATE_DATA,
+	TFRC_RSTATE_TERM    = 127,
+};
+
+#ifdef 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",
+	[TFRC_RSTATE_TERM]    = "TERM",
+	};
+
+	return ccid3_rx_state_names[state];
+}
+#endif
+
+static inline 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;
+
+	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;
+}
+
+static void ccid3_hc_rx_send_feedback(struct sock *sk)
+{
+	struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
+	struct dccp_sock *dp = dccp_sk(sk);
+	struct dccp_rx_hist_entry *packet;
+	struct timeval now;
+
+	ccid3_pr_debug("%s, sk=%p\n", dccp_role(sk), sk);
+
+	dccp_timestamp(sk, &now);
+
+	switch (hcrx->ccid3hcrx_state) {
+	case TFRC_RSTATE_NO_DATA:
+		hcrx->ccid3hcrx_x_recv = 0;
+		break;
+	case TFRC_RSTATE_DATA: {
+		const u32 delta = timeval_delta(&now,
+					&hcrx->ccid3hcrx_tstamp_last_feedback);
+		hcrx->ccid3hcrx_x_recv = usecs_div(hcrx->ccid3hcrx_bytes_recv,
+						   delta);
+	}
+		break;
+	default:
+		printk(KERN_CRIT "%s: %s, sk=%p, Illegal state (%d)!\n",
+		       __FUNCTION__, dccp_role(sk), sk, hcrx->ccid3hcrx_state);
+		dump_stack();
+		return;
+	}
+
+	packet = dccp_rx_hist_find_data_packet(&hcrx->ccid3hcrx_hist);
+	if (unlikely(packet == NULL)) {
+		LIMIT_NETDEBUG(KERN_WARNING "%s: %s, sk=%p, no data packet "
+			       "in history!\n",
+			       __FUNCTION__, dccp_role(sk), sk);
+		return;
+	}
+
+	hcrx->ccid3hcrx_tstamp_last_feedback = now;
+	hcrx->ccid3hcrx_last_counter	     = packet->dccphrx_ccval;
+	hcrx->ccid3hcrx_seqno_last_counter   = packet->dccphrx_seqno;
+	hcrx->ccid3hcrx_bytes_recv	     = 0;
+
+	/* Convert to multiples of 10us */
+	hcrx->ccid3hcrx_elapsed_time =
+			timeval_delta(&now, &packet->dccphrx_tstamp) / 10;
+	if (hcrx->ccid3hcrx_p == 0)
+		hcrx->ccid3hcrx_pinv = ~0;
+	else
+		hcrx->ccid3hcrx_pinv = 1000000 / hcrx->ccid3hcrx_p;
+	dp->dccps_hc_rx_insert_options = 1;
+	dccp_send_ack(sk);
+}
+
+static void ccid3_hc_rx_insert_options(struct sock *sk, struct sk_buff *skb)
+{
+	const struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
+	u32 x_recv, pinv;
+
+	BUG_ON(hcrx == NULL);
+
+	if (!(sk->sk_state == DCCP_OPEN || sk->sk_state == DCCP_PARTOPEN))
+		return;
+
+	DCCP_SKB_CB(skb)->dccpd_ccval = hcrx->ccid3hcrx_last_counter;
+
+	if (dccp_packet_without_ack(skb))
+		return;
+		
+	if (hcrx->ccid3hcrx_elapsed_time != 0)
+		dccp_insert_option_elapsed_time(sk, skb,
+						hcrx->ccid3hcrx_elapsed_time);
+	dccp_insert_option_timestamp(sk, skb);
+	x_recv = htonl(hcrx->ccid3hcrx_x_recv);
+	pinv   = htonl(hcrx->ccid3hcrx_pinv);
+	dccp_insert_option(sk, skb, TFRC_OPT_LOSS_EVENT_RATE,
+			   &pinv, sizeof(pinv));
+	dccp_insert_option(sk, skb, TFRC_OPT_RECEIVE_RATE,
+			   &x_recv, sizeof(x_recv));
+}
+
+/* calculate first loss interval
+ *
+ * returns estimated loss interval in usecs */
+
+static u32 ccid3_hc_rx_calc_first_li(struct sock *sk)
+{
+	struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
+	struct dccp_rx_hist_entry *entry, *next, *tail = NULL;
+	u32 rtt, delta, x_recv, fval, p, tmp2;
+	struct timeval tstamp = { 0, };
+	int interval = 0;
+	int win_count = 0;
+	int step = 0;
+	u64 tmp1;
+
+	list_for_each_entry_safe(entry, next, &hcrx->ccid3hcrx_hist,
+				 dccphrx_node) {
+		if (dccp_rx_hist_entry_data_packet(entry)) {
+			tail = entry;
+
+			switch (step) {
+			case 0:
+				tstamp	  = entry->dccphrx_tstamp;
+				win_count = entry->dccphrx_ccval;
+				step = 1;
+				break;
+			case 1:
+				interval = win_count - entry->dccphrx_ccval;
+				if (interval < 0)
+					interval += TFRC_WIN_COUNT_LIMIT;
+				if (interval > 4)
+					goto found;
+				break;
+			}
+		}
+	}
+
+	if (unlikely(step == 0)) {
+		LIMIT_NETDEBUG(KERN_WARNING "%s: %s, sk=%p, packet history "
+			       "contains no data packets!\n",
+			       __FUNCTION__, dccp_role(sk), sk);
+		return ~0;
+	}
+
+	if (unlikely(interval == 0)) {
+		LIMIT_NETDEBUG(KERN_WARNING "%s: %s, sk=%p, Could not find a "
+			       "win_count interval > 0. Defaulting to 1\n",
+			       __FUNCTION__, dccp_role(sk), sk);
+		interval = 1;
+	}
+found:
+	rtt = timeval_delta(&tstamp, &tail->dccphrx_tstamp) * 4 / interval;
+	ccid3_pr_debug("%s, sk=%p, approximated RTT to %uus\n",
+		       dccp_role(sk), sk, rtt);
+	if (rtt == 0)
+		rtt = 1;
+
+	dccp_timestamp(sk, &tstamp);
+	delta = timeval_delta(&tstamp, &hcrx->ccid3hcrx_tstamp_last_feedback);
+	x_recv = usecs_div(hcrx->ccid3hcrx_bytes_recv, delta);
+
+	tmp1 = (u64)x_recv * (u64)rtt;
+	do_div(tmp1,10000000);
+	tmp2 = (u32)tmp1;
+	fval = (hcrx->ccid3hcrx_s * 100000) / tmp2;
+	/* do not alter order above or you will get overflow on 32 bit */
+	p = tfrc_calc_x_reverse_lookup(fval);
+	ccid3_pr_debug("%s, sk=%p, receive rate=%u bytes/s, implied "
+		       "loss rate=%u\n", dccp_role(sk), sk, x_recv, p);
+
+	if (p == 0)
+		return ~0;
+	else
+		return 1000000 / p; 
+}
+
+static void ccid3_hc_rx_update_li(struct sock *sk, u64 seq_loss, u8 win_loss)
+{
+	struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
+
+	if (seq_loss != DCCP_MAX_SEQNO + 1 &&
+	    list_empty(&hcrx->ccid3hcrx_li_hist)) {
+		struct dccp_li_hist_entry *li_tail;
+
+		li_tail = dccp_li_hist_interval_new(ccid3_li_hist,
+						    &hcrx->ccid3hcrx_li_hist,
+						    seq_loss, win_loss);
+		if (li_tail == NULL)
+			return;
+		li_tail->dccplih_interval = ccid3_hc_rx_calc_first_li(sk);
+	} else
+		    LIMIT_NETDEBUG(KERN_WARNING "%s: FIXME: find end of "
+				   "interval\n", __FUNCTION__);
+}
+
+static void ccid3_hc_rx_detect_loss(struct sock *sk)
+{
+	struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
+	u8 win_loss;
+	const u64 seq_loss = dccp_rx_hist_detect_loss(&hcrx->ccid3hcrx_hist,
+						      &hcrx->ccid3hcrx_li_hist,
+						      &win_loss);
+
+	ccid3_hc_rx_update_li(sk, seq_loss, win_loss);
+}
+
+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);
+	const struct dccp_options_received *opt_recv;
+	struct dccp_rx_hist_entry *packet;
+	struct timeval now;
+	u8 win_count;
+	u32 p_prev, r_sample, t_elapsed;
+	int ins;
+
+	BUG_ON(hcrx == NULL ||
+	       !(hcrx->ccid3hcrx_state == TFRC_RSTATE_NO_DATA ||
+		 hcrx->ccid3hcrx_state == TFRC_RSTATE_DATA));
+
+	opt_recv = &dccp_sk(sk)->dccps_options_received;
+
+	switch (DCCP_SKB_CB(skb)->dccpd_type) {
+	case DCCP_PKT_ACK:
+		if (hcrx->ccid3hcrx_state == TFRC_RSTATE_NO_DATA)
+			return;
+	case DCCP_PKT_DATAACK:
+		if (opt_recv->dccpor_timestamp_echo == 0)
+			break;
+		p_prev = hcrx->ccid3hcrx_rtt;
+		dccp_timestamp(sk, &now);
+		timeval_sub_usecs(&now, opt_recv->dccpor_timestamp_echo * 10);
+		r_sample = timeval_usecs(&now);
+		t_elapsed = opt_recv->dccpor_elapsed_time * 10;
+
+		if (unlikely(r_sample <= t_elapsed))
+			LIMIT_NETDEBUG(KERN_WARNING "%s: r_sample=%uus, "
+				       "t_elapsed=%uus\n",
+				       __FUNCTION__, r_sample, t_elapsed);
+		else
+			r_sample -= t_elapsed;
+
+		if (hcrx->ccid3hcrx_state == TFRC_RSTATE_NO_DATA)
+			hcrx->ccid3hcrx_rtt = r_sample;
+		else
+			hcrx->ccid3hcrx_rtt = (hcrx->ccid3hcrx_rtt * 9) / 10 +
+					      r_sample / 10;
+
+		if (p_prev != hcrx->ccid3hcrx_rtt)
+			ccid3_pr_debug("%s, New RTT=%luus, elapsed time=%u\n",
+				       dccp_role(sk), hcrx->ccid3hcrx_rtt,
+				       opt_recv->dccpor_elapsed_time);
+		break;
+	case DCCP_PKT_DATA:
+		break;
+	default: /* We're not interested in other packet types, move along */
+		return;
+	}
+
+	packet = dccp_rx_hist_entry_new(ccid3_rx_hist, sk, opt_recv->dccpor_ndp,
+					skb, SLAB_ATOMIC);
+	if (unlikely(packet == NULL)) {
+		LIMIT_NETDEBUG(KERN_WARNING "%s: %s, sk=%p, Not enough mem to "
+				"add rx packet to history, consider it lost!\n",
+			       __FUNCTION__, dccp_role(sk), sk);
+		return;
+	}
+
+	win_count = packet->dccphrx_ccval;
+
+	ins = dccp_rx_hist_add_packet(ccid3_rx_hist, &hcrx->ccid3hcrx_hist,
+				      &hcrx->ccid3hcrx_li_hist, packet);
+
+	if (DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_ACK)
+		return;
+
+	switch (hcrx->ccid3hcrx_state) {
+	case TFRC_RSTATE_NO_DATA:
+		ccid3_pr_debug("%s, sk=%p(%s), skb=%p, sending initial "
+			       "feedback\n",
+			       dccp_role(sk), sk,
+			       dccp_state_name(sk->sk_state), skb);
+		ccid3_hc_rx_send_feedback(sk);
+		ccid3_hc_rx_set_state(sk, TFRC_RSTATE_DATA);
+		return;
+	case TFRC_RSTATE_DATA:
+		hcrx->ccid3hcrx_bytes_recv += skb->len -
+					      dccp_hdr(skb)->dccph_doff * 4;
+		if (ins != 0)
+			break;
+
+		dccp_timestamp(sk, &now);
+		if (timeval_delta(&now, &hcrx->ccid3hcrx_tstamp_last_ack) >=
+		    hcrx->ccid3hcrx_rtt) {
+			hcrx->ccid3hcrx_tstamp_last_ack = now;
+			ccid3_hc_rx_send_feedback(sk);
+		}
+		return;
+	default:
+		printk(KERN_CRIT "%s: %s, sk=%p, Illegal state (%d)!\n",
+		       __FUNCTION__, dccp_role(sk), sk, hcrx->ccid3hcrx_state);
+		dump_stack();
+		return;
+	}
+
+	/* Dealing with packet loss */
+	ccid3_pr_debug("%s, sk=%p(%s), data loss! Reacting...\n",
+		       dccp_role(sk), sk, dccp_state_name(sk->sk_state));
+
+	ccid3_hc_rx_detect_loss(sk);
+	p_prev = hcrx->ccid3hcrx_p;
+	
+	/* Calculate loss event rate */
+	if (!list_empty(&hcrx->ccid3hcrx_li_hist))
+		/* Scaling up by 1000000 as fixed decimal */
+		hcrx->ccid3hcrx_p = 1000000 / dccp_li_hist_calc_i_mean(&hcrx->ccid3hcrx_li_hist);
+
+	if (hcrx->ccid3hcrx_p > p_prev) {
+		ccid3_hc_rx_send_feedback(sk);
+		return;
+	}
+}
+
+static int ccid3_hc_rx_init(struct sock *sk)
+{
+	struct dccp_sock *dp = dccp_sk(sk);
+	struct ccid3_hc_rx_sock *hcrx;
+
+	ccid3_pr_debug("%s, sk=%p\n", dccp_role(sk), sk);
+
+	dp->dccps_hc_rx_ccid_private = kmalloc(sizeof(*hcrx), gfp_any());
+	if (dp->dccps_hc_rx_ccid_private == NULL)
+		return -ENOMEM;
+
+	hcrx = ccid3_hc_rx_sk(sk);
+	memset(hcrx, 0, sizeof(*hcrx));
+
+	if (dp->dccps_packet_size >= TFRC_MIN_PACKET_SIZE &&
+	    dp->dccps_packet_size <= TFRC_MAX_PACKET_SIZE)
+		hcrx->ccid3hcrx_s = dp->dccps_packet_size;
+	else
+		hcrx->ccid3hcrx_s = TFRC_STD_PACKET_SIZE;
+
+	hcrx->ccid3hcrx_state = TFRC_RSTATE_NO_DATA;
+	INIT_LIST_HEAD(&hcrx->ccid3hcrx_hist);
+	INIT_LIST_HEAD(&hcrx->ccid3hcrx_li_hist);
+	dccp_timestamp(sk, &hcrx->ccid3hcrx_tstamp_last_ack);
+	hcrx->ccid3hcrx_tstamp_last_feedback = hcrx->ccid3hcrx_tstamp_last_ack;
+	hcrx->ccid3hcrx_rtt = 5000; /* XXX 5ms for now... */
+	return 0;
+}
+
+static void ccid3_hc_rx_exit(struct sock *sk)
+{
+	struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
+	struct dccp_sock *dp = dccp_sk(sk);
+
+	BUG_ON(hcrx == NULL);
+
+	ccid3_hc_rx_set_state(sk, TFRC_RSTATE_TERM);
+
+	/* Empty packet history */
+	dccp_rx_hist_purge(ccid3_rx_hist, &hcrx->ccid3hcrx_hist);
+
+	/* Empty loss interval history */
+	dccp_li_hist_purge(ccid3_li_hist, &hcrx->ccid3hcrx_li_hist);
+
+	kfree(dp->dccps_hc_rx_ccid_private);
+	dp->dccps_hc_rx_ccid_private = NULL;
+}
+
+static void ccid3_hc_rx_get_info(struct sock *sk, struct tcp_info *info)
+{
+	const struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
+
+	/* Listen socks doesn't have a private CCID block */
+	if (sk->sk_state == DCCP_LISTEN)
+		return;
+
+	BUG_ON(hcrx == NULL);
+
+	info->tcpi_ca_state	= hcrx->ccid3hcrx_state;
+	info->tcpi_options	|= TCPI_OPT_TIMESTAMPS;
+	info->tcpi_rcv_rtt	= hcrx->ccid3hcrx_rtt;
+}
+
+static void ccid3_hc_tx_get_info(struct sock *sk, struct tcp_info *info)
+{
+	const struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
+
+	/* Listen socks doesn't have a private CCID block */
+	if (sk->sk_state == DCCP_LISTEN)
+		return;
+
+	BUG_ON(hctx == NULL);
+
+	info->tcpi_rto = hctx->ccid3hctx_t_rto;
+	info->tcpi_rtt = hctx->ccid3hctx_rtt;
+}
+
+static struct ccid ccid3 = {
+	.ccid_id		   = 3,
+	.ccid_name		   = "ccid3",
+	.ccid_owner		   = THIS_MODULE,
+	.ccid_init		   = ccid3_init,
+	.ccid_exit		   = ccid3_exit,
+	.ccid_hc_tx_init	   = ccid3_hc_tx_init,
+	.ccid_hc_tx_exit	   = ccid3_hc_tx_exit,
+	.ccid_hc_tx_send_packet	   = ccid3_hc_tx_send_packet,
+	.ccid_hc_tx_packet_sent	   = ccid3_hc_tx_packet_sent,
+	.ccid_hc_tx_packet_recv	   = ccid3_hc_tx_packet_recv,
+	.ccid_hc_tx_insert_options = ccid3_hc_tx_insert_options,
+	.ccid_hc_tx_parse_options  = ccid3_hc_tx_parse_options,
+	.ccid_hc_rx_init	   = ccid3_hc_rx_init,
+	.ccid_hc_rx_exit	   = ccid3_hc_rx_exit,
+	.ccid_hc_rx_insert_options = ccid3_hc_rx_insert_options,
+	.ccid_hc_rx_packet_recv	   = ccid3_hc_rx_packet_recv,
+	.ccid_hc_rx_get_info	   = ccid3_hc_rx_get_info,
+	.ccid_hc_tx_get_info	   = ccid3_hc_tx_get_info,
+};
+ 
+module_param(ccid3_debug, int, 0444);
+MODULE_PARM_DESC(ccid3_debug, "Enable debug messages");
+
+static __init int ccid3_module_init(void)
+{
+	int rc = -ENOBUFS;
+
+	ccid3_rx_hist = dccp_rx_hist_new("ccid3");
+	if (ccid3_rx_hist == NULL)
+		goto out;
+
+	ccid3_tx_hist = dccp_tx_hist_new("ccid3");
+	if (ccid3_tx_hist == NULL)
+		goto out_free_rx;
+
+	ccid3_li_hist = dccp_li_hist_new("ccid3");
+	if (ccid3_li_hist == NULL)
+		goto out_free_tx;
+
+	rc = ccid_register(&ccid3);
+	if (rc != 0) 
+		goto out_free_loss_interval_history;
+out:
+	return rc;
+
+out_free_loss_interval_history:
+	dccp_li_hist_delete(ccid3_li_hist);
+	ccid3_li_hist = NULL;
+out_free_tx:
+	dccp_tx_hist_delete(ccid3_tx_hist);
+	ccid3_tx_hist = NULL;
+out_free_rx:
+	dccp_rx_hist_delete(ccid3_rx_hist);
+	ccid3_rx_hist = NULL;
+	goto out;
+}
+module_init(ccid3_module_init);
+
+static __exit void ccid3_module_exit(void)
+{
+#ifdef CONFIG_IP_DCCP_UNLOAD_HACK
+	/*
+	 * Hack to use while developing, so that we get rid of the control
+	 * sock, that is what keeps a refcount on dccp.ko -acme
+	 */
+	extern void dccp_ctl_sock_exit(void);
+
+	dccp_ctl_sock_exit();
+#endif
+	ccid_unregister(&ccid3);
+
+	if (ccid3_tx_hist != NULL) {
+		dccp_tx_hist_delete(ccid3_tx_hist);
+		ccid3_tx_hist = NULL;
+	}
+	if (ccid3_rx_hist != NULL) {
+		dccp_rx_hist_delete(ccid3_rx_hist);
+		ccid3_rx_hist = NULL;
+	}
+	if (ccid3_li_hist != NULL) {
+		dccp_li_hist_delete(ccid3_li_hist);
+		ccid3_li_hist = NULL;
+	}
+}
+module_exit(ccid3_module_exit);
+
+MODULE_AUTHOR("Ian McDonald <iam4@cs.waikato.ac.nz>, "
+	      "Arnaldo Carvalho de Melo <acme@ghostprotocols.net>");
+MODULE_DESCRIPTION("DCCP TFRC CCID3 CCID");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("net-dccp-ccid-3");