Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6

* 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (867 commits)
  [SKY2]: status polling loop (post merge)
  [NET]: Fix NAPI completion handling in some drivers.
  [TCP]: Limit processing lost_retrans loop to work-to-do cases
  [TCP]: Fix lost_retrans loop vs fastpath problems
  [TCP]: No need to re-count fackets_out/sacked_out at RTO
  [TCP]: Extract tcp_match_queue_to_sack from sacktag code
  [TCP]: Kill almost unused variable pcount from sacktag
  [TCP]: Fix mark_head_lost to ignore R-bit when trying to mark L
  [TCP]: Add bytes_acked (ABC) clearing to FRTO too
  [IPv6]: Update setsockopt(IPV6_MULTICAST_IF) to support RFC 3493, try2
  [NETFILTER]: x_tables: add missing ip6t_modulename aliases
  [NETFILTER]: nf_conntrack_tcp: fix connection reopening
  [QETH]: fix qeth_main.c
  [NETLINK]: fib_frontend build fixes
  [IPv6]: Export userland ND options through netlink (RDNSS support)
  [9P]: build fix with !CONFIG_SYSCTL
  [NET]: Fix dev_put() and dev_hold() comments
  [NET]: make netlink user -> kernel interface synchronious
  [NET]: unify netlink kernel socket recognition
  [NET]: cleanup 3rd argument in netlink_sendskb
  ...

Fix up conflicts manually in Documentation/feature-removal-schedule.txt
and my new least favourite crap, the "mod_devicetable" support in the
files include/linux/mod_devicetable.h and scripts/mod/file2alias.c.

(The latter files seem to be explicitly _designed_ to get conflicts when
different subsystems work with them - that have an absolutely horrid
lack of subsystem separation!)

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

20 files changed, 339 insertions, 442 deletions

diff --git a/net/dccp/ackvec.c b/net/dccp/ackvec.c
index 7ac775f9a64..83378f379f7 100644
--- a/net/dccp/ackvec.c
+++ b/net/dccp/ackvec.c
@@ -69,21 +69,20 @@ int dccp_insert_option_ackvec(struct sock *sk, struct sk_buff *skb)
 	struct dccp_sock *dp = dccp_sk(sk);
 	struct dccp_ackvec *av = dp->dccps_hc_rx_ackvec;
 	/* Figure out how many options do we need to represent the ackvec */
-	const u16 nr_opts = (av->dccpav_vec_len +
-			     DCCP_MAX_ACKVEC_OPT_LEN - 1) /
-			    DCCP_MAX_ACKVEC_OPT_LEN;
+	const u16 nr_opts = DIV_ROUND_UP(av->dccpav_vec_len,
+					 DCCP_MAX_ACKVEC_OPT_LEN);
 	u16 len = av->dccpav_vec_len + 2 * nr_opts, i;
-	struct timeval now;
 	u32 elapsed_time;
 	const unsigned char *tail, *from;
 	unsigned char *to;
 	struct dccp_ackvec_record *avr;
+	suseconds_t delta;
 
 	if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
 		return -1;
 
-	dccp_timestamp(sk, &now);
-	elapsed_time = timeval_delta(&now, &av->dccpav_time) / 10;
+	delta = ktime_us_delta(ktime_get_real(), av->dccpav_time);
+	elapsed_time = delta / 10;
 
 	if (elapsed_time != 0 &&
 	    dccp_insert_option_elapsed_time(sk, skb, elapsed_time))
@@ -159,8 +158,7 @@ struct dccp_ackvec *dccp_ackvec_alloc(const gfp_t priority)
 		av->dccpav_buf_head	= DCCP_MAX_ACKVEC_LEN - 1;
 		av->dccpav_buf_ackno	= UINT48_MAX + 1;
 		av->dccpav_buf_nonce = av->dccpav_buf_nonce = 0;
-		av->dccpav_time.tv_sec	= 0;
-		av->dccpav_time.tv_usec	= 0;
+		av->dccpav_time	     = ktime_set(0, 0);
 		av->dccpav_vec_len	= 0;
 		INIT_LIST_HEAD(&av->dccpav_records);
 	}
@@ -321,7 +319,7 @@ int dccp_ackvec_add(struct dccp_ackvec *av, const struct sock *sk,
 	}
 
 	av->dccpav_buf_ackno = ackno;
-	dccp_timestamp(sk, &av->dccpav_time);
+	av->dccpav_time = ktime_get_real();
 out:
 	return 0;
 
diff --git a/net/dccp/ackvec.h b/net/dccp/ackvec.h
index 96504a3b16e..9ef0737043e 100644
--- a/net/dccp/ackvec.h
+++ b/net/dccp/ackvec.h
@@ -12,8 +12,8 @@
  */
 
 #include <linux/compiler.h>
+#include <linux/ktime.h>
 #include <linux/list.h>
-#include <linux/time.h>
 #include <linux/types.h>
 
 /* Read about the ECN nonce to see why it is 253 */
@@ -52,7 +52,7 @@
 struct dccp_ackvec {
 	u64		dccpav_buf_ackno;
 	struct list_head dccpav_records;
-	struct timeval	dccpav_time;
+	ktime_t		dccpav_time;
 	u16		dccpav_buf_head;
 	u16		dccpav_vec_len;
 	u8		dccpav_buf_nonce;
diff --git a/net/dccp/ccids/ccid2.c b/net/dccp/ccids/ccid2.c
index d29b88fe723..426008e3b7e 100644
--- a/net/dccp/ccids/ccid2.c
+++ b/net/dccp/ccids/ccid2.c
@@ -59,7 +59,8 @@ static void ccid2_hc_tx_check_sanity(const struct ccid2_hc_tx_sock *hctx)
 				pipe++;
 
 			/* packets are sent sequentially */
-			BUG_ON(seqp->ccid2s_seq <= prev->ccid2s_seq);
+			BUG_ON(dccp_delta_seqno(seqp->ccid2s_seq,
+						prev->ccid2s_seq ) >= 0);
 			BUG_ON(time_before(seqp->ccid2s_sent,
 					   prev->ccid2s_sent));
 
@@ -83,8 +84,7 @@ static void ccid2_hc_tx_check_sanity(const struct ccid2_hc_tx_sock *hctx)
 #define ccid2_hc_tx_check_sanity(hctx)
 #endif
 
-static int ccid2_hc_tx_alloc_seq(struct ccid2_hc_tx_sock *hctx, int num,
-				 gfp_t gfp)
+static int ccid2_hc_tx_alloc_seq(struct ccid2_hc_tx_sock *hctx)
 {
 	struct ccid2_seq *seqp;
 	int i;
@@ -95,16 +95,16 @@ static int ccid2_hc_tx_alloc_seq(struct ccid2_hc_tx_sock *hctx, int num,
 		return -ENOMEM;
 
 	/* allocate buffer and initialize linked list */
-	seqp = kmalloc(sizeof(*seqp) * num, gfp);
+	seqp = kmalloc(CCID2_SEQBUF_LEN * sizeof(struct ccid2_seq), gfp_any());
 	if (seqp == NULL)
 		return -ENOMEM;
 
-	for (i = 0; i < (num - 1); i++) {
+	for (i = 0; i < (CCID2_SEQBUF_LEN - 1); i++) {
 		seqp[i].ccid2s_next = &seqp[i + 1];
 		seqp[i + 1].ccid2s_prev = &seqp[i];
 	}
-	seqp[num - 1].ccid2s_next = seqp;
-	seqp->ccid2s_prev = &seqp[num - 1];
+	seqp[CCID2_SEQBUF_LEN - 1].ccid2s_next = seqp;
+	seqp->ccid2s_prev = &seqp[CCID2_SEQBUF_LEN - 1];
 
 	/* This is the first allocation.  Initiate the head and tail.  */
 	if (hctx->ccid2hctx_seqbufc == 0)
@@ -114,8 +114,8 @@ static int ccid2_hc_tx_alloc_seq(struct ccid2_hc_tx_sock *hctx, int num,
 		hctx->ccid2hctx_seqh->ccid2s_next = seqp;
 		seqp->ccid2s_prev = hctx->ccid2hctx_seqh;
 
-		hctx->ccid2hctx_seqt->ccid2s_prev = &seqp[num - 1];
-		seqp[num - 1].ccid2s_next = hctx->ccid2hctx_seqt;
+		hctx->ccid2hctx_seqt->ccid2s_prev = &seqp[CCID2_SEQBUF_LEN - 1];
+		seqp[CCID2_SEQBUF_LEN - 1].ccid2s_next = hctx->ccid2hctx_seqt;
 	}
 
 	/* store the original pointer to the buffer so we can free it */
@@ -127,19 +127,7 @@ static int ccid2_hc_tx_alloc_seq(struct ccid2_hc_tx_sock *hctx, int num,
 
 static int ccid2_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb)
 {
-	struct ccid2_hc_tx_sock *hctx;
-
-	switch (DCCP_SKB_CB(skb)->dccpd_type) {
-	case 0: /* XXX data packets from userland come through like this */
-	case DCCP_PKT_DATA:
-	case DCCP_PKT_DATAACK:
-		break;
-	/* No congestion control on other packets */
-	default:
-		return 0;
-	}
-
-	hctx = ccid2_hc_tx_sk(sk);
+	struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk);
 
 	ccid2_pr_debug("pipe=%d cwnd=%d\n", hctx->ccid2hctx_pipe,
 		       hctx->ccid2hctx_cwnd);
@@ -180,16 +168,11 @@ static void ccid2_change_l_ack_ratio(struct sock *sk, int val)
 	dp->dccps_l_ack_ratio = val;
 }
 
-static void ccid2_change_cwnd(struct ccid2_hc_tx_sock *hctx, int val)
+static void ccid2_change_cwnd(struct ccid2_hc_tx_sock *hctx, u32 val)
 {
-	if (val == 0)
-		val = 1;
-
 	/* XXX do we need to change ack ratio? */
-	ccid2_pr_debug("change cwnd to %d\n", val);
-
-	BUG_ON(val < 1);
-	hctx->ccid2hctx_cwnd = val;
+	hctx->ccid2hctx_cwnd = val? : 1;
+	ccid2_pr_debug("changed cwnd to %u\n", hctx->ccid2hctx_cwnd);
 }
 
 static void ccid2_change_srtt(struct ccid2_hc_tx_sock *hctx, long val)
@@ -295,12 +278,11 @@ static void ccid2_hc_tx_packet_sent(struct sock *sk, int more, unsigned int len)
 	next = hctx->ccid2hctx_seqh->ccid2s_next;
 	/* check if we need to alloc more space */
 	if (next == hctx->ccid2hctx_seqt) {
-		int rc;
-
-		ccid2_pr_debug("allocating more space in history\n");
-		rc = ccid2_hc_tx_alloc_seq(hctx, CCID2_SEQBUF_LEN, gfp_any());
-		BUG_ON(rc); /* XXX what do we do? */
-
+		if (ccid2_hc_tx_alloc_seq(hctx)) {
+			DCCP_CRIT("packet history - out of memory!");
+			/* FIXME: find a more graceful way to bail out */
+			return;
+		}
 		next = hctx->ccid2hctx_seqh->ccid2s_next;
 		BUG_ON(next == hctx->ccid2hctx_seqt);
 	}
@@ -581,8 +563,8 @@ static void ccid2_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb)
 		hctx->ccid2hctx_rpseq = seqno;
 	} else {
 		/* check if packet is consecutive */
-		if ((hctx->ccid2hctx_rpseq + 1) == seqno)
-			hctx->ccid2hctx_rpseq++;
+		if (dccp_delta_seqno(hctx->ccid2hctx_rpseq, seqno) == 1)
+			hctx->ccid2hctx_rpseq = seqno;
 		/* it's a later packet */
 		else if (after48(seqno, hctx->ccid2hctx_rpseq)) {
 			hctx->ccid2hctx_rpdupack++;
@@ -771,7 +753,7 @@ static int ccid2_hc_tx_init(struct ccid *ccid, struct sock *sk)
 	hctx->ccid2hctx_seqbufc   = 0;
 
 	/* XXX init ~ to window size... */
-	if (ccid2_hc_tx_alloc_seq(hctx, CCID2_SEQBUF_LEN, GFP_ATOMIC) != 0)
+	if (ccid2_hc_tx_alloc_seq(hctx))
 		return -ENOMEM;
 
 	hctx->ccid2hctx_sent	 = 0;
@@ -835,7 +817,7 @@ static struct ccid_operations ccid2 = {
 };
 
 #ifdef CONFIG_IP_DCCP_CCID2_DEBUG
-module_param(ccid2_debug, int, 0444);
+module_param(ccid2_debug, bool, 0444);
 MODULE_PARM_DESC(ccid2_debug, "Enable debug messages");
 #endif
 
diff --git a/net/dccp/ccids/ccid2.h b/net/dccp/ccids/ccid2.h
index ebd79499c85..d9daa534c9b 100644
--- a/net/dccp/ccids/ccid2.h
+++ b/net/dccp/ccids/ccid2.h
@@ -50,7 +50,7 @@ struct ccid2_seq {
  * @ccid2hctx_rpdupack - dupacks since rpseq
 */
 struct ccid2_hc_tx_sock {
-	int			ccid2hctx_cwnd;
+	u32			ccid2hctx_cwnd;
 	int			ccid2hctx_ssacks;
 	int			ccid2hctx_acks;
 	unsigned int		ccid2hctx_ssthresh;
diff --git a/net/dccp/ccids/ccid3.c b/net/dccp/ccids/ccid3.c
index e91c2b9dc27..25772c32617 100644
--- a/net/dccp/ccids/ccid3.c
+++ b/net/dccp/ccids/ccid3.c
@@ -113,27 +113,24 @@ static inline void ccid3_update_send_interval(struct ccid3_hc_tx_sock *hctx)
 		       hctx->ccid3hctx_s, (unsigned)(hctx->ccid3hctx_x >> 6));
 
 }
-/*
- * 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;
+
+/**
+ * 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
  *       fine-grained resolution of sending rates. This requires scaling by 2^6
  *       throughout the code. Only X_calc is unscaled (in bytes/second).
  *
  */
-static void ccid3_hc_tx_update_x(struct sock *sk, struct timeval *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();
 
 	/*
 	 * Handle IDLE periods: do not reduce below RFC3390 initial sending rate
@@ -153,14 +150,14 @@ static void ccid3_hc_tx_update_x(struct sock *sk, struct timeval *now)
 					(((__u64)hctx->ccid3hctx_s) << 6) /
 								TFRC_T_MBI);
 
-	} else if (timeval_delta(now, &hctx->ccid3hctx_t_ld) -
-			(suseconds_t)hctx->ccid3hctx_rtt >= 0) {
+	} else if (ktime_us_delta(now, hctx->ccid3hctx_t_ld)
+				- (s64)hctx->ccid3hctx_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;
+		hctx->ccid3hctx_t_ld = now;
 	}
 
 	if (hctx->ccid3hctx_x != old_x) {
@@ -214,7 +211,6 @@ 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 timeval now;
 	unsigned long t_nfb = USEC_PER_SEC / 5;
 
 	bh_lock_sock(sk);
@@ -265,15 +261,12 @@ static void ccid3_hc_tx_no_feedback_timer(unsigned long data)
 				max(hctx->ccid3hctx_x_recv / 2,
 				    (((__u64)hctx->ccid3hctx_s) << 6) /
 							      (2 * TFRC_T_MBI));
-
-			if (hctx->ccid3hctx_p == 0)
-				dccp_timestamp(sk, &now);
 		} 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, &now);
+		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)
@@ -309,8 +302,6 @@ static int ccid3_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb)
 	ktime_t now = ktime_get_real();
 	s64 delay;
 
-	BUG_ON(hctx == NULL);
-
 	/*
 	 * This function is called only for Data and DataAck packets. Sending
 	 * zero-sized Data(Ack)s is theoretically possible, but for congestion
@@ -341,7 +332,7 @@ static int ccid3_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb)
 			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 = ktime_to_timeval(now);
+			hctx->ccid3hctx_t_ld = now;
 		} else {
 			/* Sender does not have RTT sample: X = MSS/second */
 			hctx->ccid3hctx_x = dp->dccps_mss_cache;
@@ -388,11 +379,8 @@ static void ccid3_hc_tx_packet_sent(struct sock *sk, int more,
 				    unsigned int len)
 {
 	struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
-	struct timeval now;
 	struct dccp_tx_hist_entry *packet;
 
-	BUG_ON(hctx == NULL);
-
 	ccid3_hc_tx_update_s(hctx, len);
 
 	packet = dccp_tx_hist_entry_new(ccid3_tx_hist, GFP_ATOMIC);
@@ -402,8 +390,7 @@ static void ccid3_hc_tx_packet_sent(struct sock *sk, int more,
 	}
 	dccp_tx_hist_add_entry(&hctx->ccid3hctx_hist, packet);
 
-	dccp_timestamp(sk, &now);
-	packet->dccphtx_tstamp = now;
+	packet->dccphtx_tstamp = ktime_get_real();
 	packet->dccphtx_seqno  = dccp_sk(sk)->dccps_gss;
 	packet->dccphtx_rtt    = hctx->ccid3hctx_rtt;
 	packet->dccphtx_sent   = 1;
@@ -414,12 +401,10 @@ 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 dccp_tx_hist_entry *packet;
-	struct timeval now;
+	ktime_t now;
 	unsigned long t_nfb;
 	u32 pinv, r_sample;
 
-	BUG_ON(hctx == NULL);
-
 	/* 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))
@@ -452,13 +437,12 @@ static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb)
 		else				       /* can not exceed 100% */
 			hctx->ccid3hctx_p = 1000000 / pinv;
 
-		dccp_timestamp(sk, &now);
-
+		now = ktime_get_real();
 		/*
 		 * Calculate new round trip sample as per [RFC 3448, 4.3] by
 		 *	R_sample  =  (now - t_recvdata) - t_elapsed
 		 */
-		r_sample = dccp_sample_rtt(sk, &now, &packet->dccphtx_tstamp);
+		r_sample = dccp_sample_rtt(sk, ktime_us_delta(now, packet->dccphtx_tstamp));
 
 		/*
 		 * Update RTT estimate by
@@ -561,8 +545,6 @@ static int ccid3_hc_tx_parse_options(struct sock *sk, unsigned char option,
 	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) {
@@ -636,8 +618,6 @@ static void ccid3_hc_tx_exit(struct sock *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);
 
@@ -647,14 +627,13 @@ static void ccid3_hc_tx_exit(struct sock *sk)
 
 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);
+	struct ccid3_hc_tx_sock *hctx;
 
 	/* Listen socks doesn't have a private CCID block */
 	if (sk->sk_state == DCCP_LISTEN)
 		return;
 
-	BUG_ON(hctx == NULL);
-
+	hctx = ccid3_hc_tx_sk(sk);
 	info->tcpi_rto = hctx->ccid3hctx_t_rto;
 	info->tcpi_rtt = hctx->ccid3hctx_rtt;
 }
@@ -662,13 +641,14 @@ static void ccid3_hc_tx_get_info(struct sock *sk, struct tcp_info *info)
 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 = ccid3_hc_tx_sk(sk);
+	const struct ccid3_hc_tx_sock *hctx;
 	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))
@@ -729,20 +709,20 @@ 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;
+	ktime_t now;
 	suseconds_t delta;
 
 	ccid3_pr_debug("%s(%p) - entry \n", dccp_role(sk), sk);
 
-	dccp_timestamp(sk, &now);
+	now = ktime_get_real();
 
 	switch (hcrx->ccid3hcrx_state) {
 	case TFRC_RSTATE_NO_DATA:
 		hcrx->ccid3hcrx_x_recv = 0;
 		break;
 	case TFRC_RSTATE_DATA:
-		delta = timeval_delta(&now,
-				      &hcrx->ccid3hcrx_tstamp_last_feedback);
+		delta = ktime_us_delta(now,
+				       hcrx->ccid3hcrx_tstamp_last_feedback);
 		DCCP_BUG_ON(delta < 0);
 		hcrx->ccid3hcrx_x_recv =
 			scaled_div32(hcrx->ccid3hcrx_bytes_recv, delta);
@@ -764,7 +744,7 @@ static void ccid3_hc_rx_send_feedback(struct sock *sk)
 	hcrx->ccid3hcrx_bytes_recv	     = 0;
 
 	/* Elapsed time information [RFC 4340, 13.2] in units of 10 * usecs */
-	delta = timeval_delta(&now, &packet->dccphrx_tstamp);
+	delta = ktime_us_delta(now, packet->dccphrx_tstamp);
 	DCCP_BUG_ON(delta < 0);
 	hcrx->ccid3hcrx_elapsed_time = delta / 10;
 
@@ -782,14 +762,13 @@ 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 = ccid3_hc_rx_sk(sk);
+	const struct ccid3_hc_rx_sock *hcrx;
 	__be32 x_recv, pinv;
 
-	BUG_ON(hcrx == NULL);
-
 	if (!(sk->sk_state == DCCP_OPEN || sk->sk_state == DCCP_PARTOPEN))
 		return 0;
 
+	hcrx = ccid3_hc_rx_sk(sk);
 	DCCP_SKB_CB(skb)->dccpd_ccval = hcrx->ccid3hcrx_ccval_last_counter;
 
 	if (dccp_packet_without_ack(skb))
@@ -839,7 +818,7 @@ static int ccid3_hc_rx_detect_loss(struct sock *sk,
 		dccp_li_update_li(sk,
 				  &hcrx->ccid3hcrx_li_hist,
 				  &hcrx->ccid3hcrx_hist,
-				  &hcrx->ccid3hcrx_tstamp_last_feedback,
+				  hcrx->ccid3hcrx_tstamp_last_feedback,
 				  hcrx->ccid3hcrx_s,
 				  hcrx->ccid3hcrx_bytes_recv,
 				  hcrx->ccid3hcrx_x_recv,
@@ -876,11 +855,9 @@ 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;
 	u32 p_prev, r_sample, rtt_prev;
 	int loss, payload_size;
-
-	BUG_ON(hcrx == NULL);
+	ktime_t now;
 
 	opt_recv = &dccp_sk(sk)->dccps_options_received;
 
@@ -891,9 +868,9 @@ static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb)
 	case DCCP_PKT_DATAACK:
 		if (opt_recv->dccpor_timestamp_echo == 0)
 			break;
+		r_sample = dccp_timestamp() - opt_recv->dccpor_timestamp_echo;
 		rtt_prev = hcrx->ccid3hcrx_rtt;
-		dccp_timestamp(sk, &now);
-		r_sample = dccp_sample_rtt(sk, &now, NULL);
+		r_sample = dccp_sample_rtt(sk, 10 * r_sample);
 
 		if (hcrx->ccid3hcrx_state == TFRC_RSTATE_NO_DATA)
 			hcrx->ccid3hcrx_rtt = r_sample;
@@ -912,7 +889,7 @@ static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb)
 		return;
 	}
 
-	packet = dccp_rx_hist_entry_new(ccid3_rx_hist, sk, opt_recv->dccpor_ndp,
+	packet = dccp_rx_hist_entry_new(ccid3_rx_hist, opt_recv->dccpor_ndp,
 					skb, GFP_ATOMIC);
 	if (unlikely(packet == NULL)) {
 		DCCP_WARN("%s(%p), Not enough mem to add rx packet "
@@ -941,9 +918,9 @@ static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb)
 		if (loss)
 			break;
 
-		dccp_timestamp(sk, &now);
-		if ((timeval_delta(&now, &hcrx->ccid3hcrx_tstamp_last_ack) -
-		     (suseconds_t)hcrx->ccid3hcrx_rtt) >= 0) {
+		now = ktime_get_real();
+		if ((ktime_us_delta(now, hcrx->ccid3hcrx_tstamp_last_ack) -
+		     (s64)hcrx->ccid3hcrx_rtt) >= 0) {
 			hcrx->ccid3hcrx_tstamp_last_ack = now;
 			ccid3_hc_rx_send_feedback(sk);
 		}
@@ -984,8 +961,8 @@ static int ccid3_hc_rx_init(struct ccid *ccid, struct sock *sk)
 	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_tstamp_last_feedback =
+		hcrx->ccid3hcrx_tstamp_last_ack = ktime_get_real();
 	hcrx->ccid3hcrx_s   = 0;
 	hcrx->ccid3hcrx_rtt = 0;
 	return 0;
@@ -995,8 +972,6 @@ static void ccid3_hc_rx_exit(struct sock *sk)
 {
 	struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
 
-	BUG_ON(hcrx == NULL);
-
 	ccid3_hc_rx_set_state(sk, TFRC_RSTATE_TERM);
 
 	/* Empty packet history */
@@ -1008,14 +983,13 @@ static void ccid3_hc_rx_exit(struct sock *sk)
 
 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);
+	const struct ccid3_hc_rx_sock *hcrx;
 
 	/* Listen socks doesn't have a private CCID block */
 	if (sk->sk_state == DCCP_LISTEN)
 		return;
 
-	BUG_ON(hcrx == NULL);
-
+	hcrx = ccid3_hc_rx_sk(sk);
 	info->tcpi_ca_state = hcrx->ccid3hcrx_state;
 	info->tcpi_options  |= TCPI_OPT_TIMESTAMPS;
 	info->tcpi_rcv_rtt  = hcrx->ccid3hcrx_rtt;
@@ -1024,13 +998,14 @@ static void ccid3_hc_rx_get_info(struct sock *sk, struct tcp_info *info)
 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 = ccid3_hc_rx_sk(sk);
+	const struct ccid3_hc_rx_sock *hcrx;
 	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(hcrx->ccid3hcrx_tfrc))
@@ -1071,7 +1046,7 @@ static struct ccid_operations ccid3 = {
 };
 
 #ifdef CONFIG_IP_DCCP_CCID3_DEBUG
-module_param(ccid3_debug, int, 0444);
+module_param(ccid3_debug, bool, 0444);
 MODULE_PARM_DESC(ccid3_debug, "Enable debug messages");
 #endif
 
diff --git a/net/dccp/ccids/ccid3.h b/net/dccp/ccids/ccid3.h
index 51d4b804e33..0cdc982cfe4 100644
--- a/net/dccp/ccids/ccid3.h
+++ b/net/dccp/ccids/ccid3.h
@@ -38,7 +38,6 @@
 
 #include <linux/ktime.h>
 #include <linux/list.h>
-#include <linux/time.h>
 #include <linux/types.h>
 #include <linux/tfrc.h>
 #include "../ccid.h"
@@ -111,13 +110,20 @@ struct ccid3_hc_tx_sock {
 	u8				ccid3hctx_idle;
 	ktime_t				ccid3hctx_t_last_win_count;
 	struct timer_list		ccid3hctx_no_feedback_timer;
-	struct timeval			ccid3hctx_t_ld;
+	ktime_t				ccid3hctx_t_ld;
 	ktime_t				ccid3hctx_t_nom;
 	u32				ccid3hctx_delta;
 	struct list_head		ccid3hctx_hist;
 	struct ccid3_options_received	ccid3hctx_options_received;
 };
 
+static inline struct ccid3_hc_tx_sock *ccid3_hc_tx_sk(const struct sock *sk)
+{
+    struct ccid3_hc_tx_sock *hctx = ccid_priv(dccp_sk(sk)->dccps_hc_tx_ccid);
+    BUG_ON(hctx == NULL);
+    return hctx;
+}
+
 /* TFRC receiver states */
 enum ccid3_hc_rx_states {
 	TFRC_RSTATE_NO_DATA = 1,
@@ -153,8 +159,8 @@ struct ccid3_hc_rx_sock {
 					ccid3hcrx_ccval_last_counter:4;
 	enum ccid3_hc_rx_states		ccid3hcrx_state:8;
 	u32				ccid3hcrx_bytes_recv;
-	struct timeval			ccid3hcrx_tstamp_last_feedback;
-	struct timeval			ccid3hcrx_tstamp_last_ack;
+	ktime_t				ccid3hcrx_tstamp_last_feedback;
+	ktime_t				ccid3hcrx_tstamp_last_ack;
 	struct list_head		ccid3hcrx_hist;
 	struct list_head		ccid3hcrx_li_hist;
 	u16				ccid3hcrx_s;
@@ -162,14 +168,11 @@ struct ccid3_hc_rx_sock {
 	u32				ccid3hcrx_elapsed_time;
 };
 
-static inline struct ccid3_hc_tx_sock *ccid3_hc_tx_sk(const struct sock *sk)
-{
-    return ccid_priv(dccp_sk(sk)->dccps_hc_tx_ccid);
-}
-
 static inline struct ccid3_hc_rx_sock *ccid3_hc_rx_sk(const struct sock *sk)
 {
-    return ccid_priv(dccp_sk(sk)->dccps_hc_rx_ccid);
+    struct ccid3_hc_rx_sock *hcrx = ccid_priv(dccp_sk(sk)->dccps_hc_rx_ccid);
+    BUG_ON(hcrx == NULL);
+    return hcrx;
 }
 
 #endif /* _DCCP_CCID3_H_ */
diff --git a/net/dccp/ccids/lib/loss_interval.c b/net/dccp/ccids/lib/loss_interval.c
index 174d3f13d93..40ad428a27f 100644
--- a/net/dccp/ccids/lib/loss_interval.c
+++ b/net/dccp/ccids/lib/loss_interval.c
@@ -125,14 +125,14 @@ static int dccp_li_hist_interval_new(struct list_head *list,
  * returns estimated loss interval in usecs */
 static u32 dccp_li_calc_first_li(struct sock *sk,
 				 struct list_head *hist_list,
-				 struct timeval *last_feedback,
+				 ktime_t last_feedback,
 				 u16 s, u32 bytes_recv,
 				 u32 previous_x_recv)
 {
 	struct dccp_rx_hist_entry *entry, *next, *tail = NULL;
 	u32 x_recv, p;
 	suseconds_t rtt, delta;
-	struct timeval tstamp = { 0, 0 };
+	ktime_t tstamp = ktime_set(0, 0);
 	int interval = 0;
 	int win_count = 0;
 	int step = 0;
@@ -176,7 +176,7 @@ found:
 		return ~0;
 	}
 
-	delta = timeval_delta(&tstamp, &tail->dccphrx_tstamp);
+	delta = ktime_us_delta(tstamp, tail->dccphrx_tstamp);
 	DCCP_BUG_ON(delta < 0);
 
 	rtt = delta * 4 / interval;
@@ -196,8 +196,7 @@ found:
 		return ~0;
 	}
 
-	dccp_timestamp(sk, &tstamp);
-	delta = timeval_delta(&tstamp, last_feedback);
+	delta = ktime_us_delta(ktime_get_real(), last_feedback);
 	DCCP_BUG_ON(delta <= 0);
 
 	x_recv = scaled_div32(bytes_recv, delta);
@@ -226,7 +225,7 @@ found:
 void dccp_li_update_li(struct sock *sk,
 		       struct list_head *li_hist_list,
 		       struct list_head *hist_list,
-		       struct timeval *last_feedback, u16 s, u32 bytes_recv,
+		       ktime_t last_feedback, u16 s, u32 bytes_recv,
 		       u32 previous_x_recv, u64 seq_loss, u8 win_loss)
 {
 	struct dccp_li_hist_entry *head;
diff --git a/net/dccp/ccids/lib/loss_interval.h b/net/dccp/ccids/lib/loss_interval.h
index 906c806d6d9..27bee92dae1 100644
--- a/net/dccp/ccids/lib/loss_interval.h
+++ b/net/dccp/ccids/lib/loss_interval.h
@@ -13,8 +13,8 @@
  *  any later version.
  */
 
+#include <linux/ktime.h>
 #include <linux/list.h>
-#include <linux/time.h>
 
 extern void dccp_li_hist_purge(struct list_head *list);
 
@@ -23,7 +23,7 @@ extern u32 dccp_li_hist_calc_i_mean(struct list_head *list);
 extern void dccp_li_update_li(struct sock *sk,
 			      struct list_head *li_hist_list,
 			      struct list_head *hist_list,
-			      struct timeval *last_feedback, u16 s,
+			      ktime_t last_feedback, u16 s,
 			      u32 bytes_recv, u32 previous_x_recv,
 			      u64 seq_loss, u8 win_loss);
 #endif /* _DCCP_LI_HIST_ */
diff --git a/net/dccp/ccids/lib/packet_history.h b/net/dccp/ccids/lib/packet_history.h
index 60d00f01539..032bb61c6e3 100644
--- a/net/dccp/ccids/lib/packet_history.h
+++ b/net/dccp/ccids/lib/packet_history.h
@@ -37,9 +37,9 @@
 #ifndef _DCCP_PKT_HIST_
 #define _DCCP_PKT_HIST_
 
+#include <linux/ktime.h>
 #include <linux/list.h>
 #include <linux/slab.h>
-#include <linux/time.h>
 
 #include "../../dccp.h"
 
@@ -57,7 +57,7 @@ struct dccp_tx_hist_entry {
 	u64		 dccphtx_seqno:48,
 			 dccphtx_sent:1;
 	u32		 dccphtx_rtt;
-	struct timeval	 dccphtx_tstamp;
+	ktime_t		 dccphtx_tstamp;
 };
 
 struct dccp_tx_hist {
@@ -124,7 +124,7 @@ struct dccp_rx_hist_entry {
 			 dccphrx_ccval:4,
 			 dccphrx_type:4;
 	u32		 dccphrx_ndp; /* In fact it is from 8 to 24 bits */
-	struct timeval	 dccphrx_tstamp;
+	ktime_t		 dccphrx_tstamp;
 };
 
 struct dccp_rx_hist {
@@ -136,7 +136,6 @@ extern void 		dccp_rx_hist_delete(struct dccp_rx_hist *hist);
 
 static inline struct dccp_rx_hist_entry *
 			dccp_rx_hist_entry_new(struct dccp_rx_hist *hist,
-					       const struct sock *sk,
 					       const u32 ndp,
 					       const struct sk_buff *skb,
 					       const gfp_t prio)
@@ -151,7 +150,7 @@ static inline struct dccp_rx_hist_entry *
 		entry->dccphrx_ccval = dh->dccph_ccval;
 		entry->dccphrx_type  = dh->dccph_type;
 		entry->dccphrx_ndp   = ndp;
-		dccp_timestamp(sk, &entry->dccphrx_tstamp);
+		entry->dccphrx_tstamp = ktime_get_real();
 	}
 
 	return entry;
diff --git a/net/dccp/dccp.h b/net/dccp/dccp.h
index e2d74cd7eee..ee97950d77d 100644
--- a/net/dccp/dccp.h
+++ b/net/dccp/dccp.h
@@ -13,6 +13,7 @@
  */
 
 #include <linux/dccp.h>
+#include <linux/ktime.h>
 #include <net/snmp.h>
 #include <net/sock.h>
 #include <net/tcp.h>
@@ -91,6 +92,7 @@ extern int  sysctl_dccp_feat_ack_ratio;
 extern int  sysctl_dccp_feat_send_ack_vector;
 extern int  sysctl_dccp_feat_send_ndp_count;
 extern int  sysctl_dccp_tx_qlen;
+extern int  sysctl_dccp_sync_ratelimit;
 
 /*
  *	48-bit sequence number arithmetic (signed and unsigned)
@@ -208,7 +210,6 @@ extern void dccp_v4_send_check(struct sock *sk, int len, struct sk_buff *skb);
 extern int  dccp_retransmit_skb(struct sock *sk, struct sk_buff *skb);
 
 extern void dccp_send_ack(struct sock *sk);
-extern void dccp_send_delayed_ack(struct sock *sk);
 extern void dccp_reqsk_send_ack(struct sk_buff *sk, struct request_sock *rsk);
 
 extern void dccp_send_sync(struct sock *sk, const u64 seq,
@@ -293,11 +294,12 @@ extern unsigned int dccp_poll(struct file *file, struct socket *sock,
 extern int	   dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr,
 				   int addr_len);
 
+extern struct sk_buff *dccp_ctl_make_reset(struct socket *ctl,
+					   struct sk_buff *skb);
 extern int	   dccp_send_reset(struct sock *sk, enum dccp_reset_codes code);
 extern void	   dccp_send_close(struct sock *sk, const int active);
 extern int	   dccp_invalid_packet(struct sk_buff *skb);
-extern u32	   dccp_sample_rtt(struct sock *sk, struct timeval *t_recv,
-						    struct timeval *t_history);
+extern u32	   dccp_sample_rtt(struct sock *sk, long delta);
 
 static inline int dccp_bad_service_code(const struct sock *sk,
 					const __be32 service)
@@ -309,10 +311,22 @@ static inline int dccp_bad_service_code(const struct sock *sk,
 	return !dccp_list_has_service(dp->dccps_service_list, service);
 }
 
+/**
+ * dccp_skb_cb  -  DCCP per-packet control information
+ * @dccpd_type: one of %dccp_pkt_type (or unknown)
+ * @dccpd_ccval: CCVal field (5.1), see e.g. RFC 4342, 8.1
+ * @dccpd_reset_code: one of %dccp_reset_codes
+ * @dccpd_reset_data: Data1..3 fields (depend on @dccpd_reset_code)
+ * @dccpd_opt_len: total length of all options (5.8) in the packet
+ * @dccpd_seq: sequence number
+ * @dccpd_ack_seq: acknowledgment number subheader field value
+ * This is used for transmission as well as for reception.
+ */
 struct dccp_skb_cb {
 	__u8  dccpd_type:4;
 	__u8  dccpd_ccval:4;
-	__u8  dccpd_reset_code;
+	__u8  dccpd_reset_code,
+	      dccpd_reset_data[3];
 	__u16 dccpd_opt_len;
 	__u64 dccpd_seq;
 	__u64 dccpd_ack_seq;
@@ -395,53 +409,14 @@ extern int dccp_insert_options(struct sock *sk, struct sk_buff *skb);
 extern int dccp_insert_option_elapsed_time(struct sock *sk,
 					    struct sk_buff *skb,
 					    u32 elapsed_time);
+extern u32 dccp_timestamp(void);
+extern void dccp_timestamping_init(void);
 extern int dccp_insert_option_timestamp(struct sock *sk,
 					 struct sk_buff *skb);
 extern int dccp_insert_option(struct sock *sk, struct sk_buff *skb,
 			       unsigned char option,
 			       const void *value, unsigned char len);
 
-extern void dccp_timestamp(const struct sock *sk, struct timeval *tv);
-
-static inline suseconds_t timeval_usecs(const struct timeval *tv)
-{
-	return tv->tv_sec * USEC_PER_SEC + tv->tv_usec;
-}
-
-static inline suseconds_t timeval_delta(const struct timeval *large,
-					const struct timeval *small)
-{
-	time_t	    secs  = large->tv_sec  - small->tv_sec;
-	suseconds_t usecs = large->tv_usec - small->tv_usec;
-
-	if (usecs < 0) {
-		secs--;
-		usecs += USEC_PER_SEC;
-	}
-	return secs * USEC_PER_SEC + usecs;
-}
-
-static inline void timeval_add_usecs(struct timeval *tv,
-				     const suseconds_t usecs)
-{
-	tv->tv_usec += usecs;
-	while (tv->tv_usec >= USEC_PER_SEC) {
-		tv->tv_sec++;
-		tv->tv_usec -= USEC_PER_SEC;
-	}
-}
-
-static inline void timeval_sub_usecs(struct timeval *tv,
-				     const suseconds_t usecs)
-{
-	tv->tv_usec -= usecs;
-	while (tv->tv_usec < 0) {
-		tv->tv_sec--;
-		tv->tv_usec += USEC_PER_SEC;
-	}
-	DCCP_BUG_ON(tv->tv_sec < 0);
-}
-
 #ifdef CONFIG_SYSCTL
 extern int dccp_sysctl_init(void);
 extern void dccp_sysctl_exit(void);
diff --git a/net/dccp/input.c b/net/dccp/input.c
index da6ec185ed5..19d7e1dbd87 100644
--- a/net/dccp/input.c
+++ b/net/dccp/input.c
@@ -68,7 +68,8 @@ static int dccp_check_seqno(struct sock *sk, struct sk_buff *skb)
 {
 	const struct dccp_hdr *dh = dccp_hdr(skb);
 	struct dccp_sock *dp = dccp_sk(sk);
-	u64 lswl, lawl;
+	u64 lswl, lawl, seqno = DCCP_SKB_CB(skb)->dccpd_seq,
+			ackno = DCCP_SKB_CB(skb)->dccpd_ack_seq;
 
 	/*
 	 *   Step 5: Prepare sequence numbers for Sync
@@ -84,11 +85,9 @@ static int dccp_check_seqno(struct sock *sk, struct sk_buff *skb)
 	 */
 	if (dh->dccph_type == DCCP_PKT_SYNC ||
 	    dh->dccph_type == DCCP_PKT_SYNCACK) {
-		if (between48(DCCP_SKB_CB(skb)->dccpd_ack_seq,
-			      dp->dccps_awl, dp->dccps_awh) &&
-		    dccp_delta_seqno(dp->dccps_swl,
-				     DCCP_SKB_CB(skb)->dccpd_seq) >= 0)
-			dccp_update_gsr(sk, DCCP_SKB_CB(skb)->dccpd_seq);
+		if (between48(ackno, dp->dccps_awl, dp->dccps_awh) &&
+		    dccp_delta_seqno(dp->dccps_swl, seqno) >= 0)
+			dccp_update_gsr(sk, seqno);
 		else
 			return -1;
 	}
@@ -103,9 +102,6 @@ static int dccp_check_seqno(struct sock *sk, struct sk_buff *skb)
 	 *	  Update S.GSR, S.SWL, S.SWH
 	 *	  If P.type != Sync,
 	 *	     Update S.GAR
-	 *      Otherwise,
-	 *	  Send Sync packet acknowledging P.seqno
-	 *	  Drop packet and return
 	 */
 	lswl = dp->dccps_swl;
 	lawl = dp->dccps_awl;
@@ -113,35 +109,52 @@ static int dccp_check_seqno(struct sock *sk, struct sk_buff *skb)
 	if (dh->dccph_type == DCCP_PKT_CLOSEREQ ||
 	    dh->dccph_type == DCCP_PKT_CLOSE ||
 	    dh->dccph_type == DCCP_PKT_RESET) {
-		lswl = dp->dccps_gsr;
-		dccp_inc_seqno(&lswl);
+		lswl = ADD48(dp->dccps_gsr, 1);
 		lawl = dp->dccps_gar;
 	}
 
-	if (between48(DCCP_SKB_CB(skb)->dccpd_seq, lswl, dp->dccps_swh) &&
-	    (DCCP_SKB_CB(skb)->dccpd_ack_seq == DCCP_PKT_WITHOUT_ACK_SEQ ||
-	     between48(DCCP_SKB_CB(skb)->dccpd_ack_seq,
-		       lawl, dp->dccps_awh))) {
-		dccp_update_gsr(sk, DCCP_SKB_CB(skb)->dccpd_seq);
+	if (between48(seqno, lswl, dp->dccps_swh) &&
+	    (ackno == DCCP_PKT_WITHOUT_ACK_SEQ ||
+	     between48(ackno, lawl, dp->dccps_awh))) {
+		dccp_update_gsr(sk, seqno);
 
 		if (dh->dccph_type != DCCP_PKT_SYNC &&
-		    (DCCP_SKB_CB(skb)->dccpd_ack_seq !=
-		     DCCP_PKT_WITHOUT_ACK_SEQ))
-			dp->dccps_gar = DCCP_SKB_CB(skb)->dccpd_ack_seq;
+		    (ackno != DCCP_PKT_WITHOUT_ACK_SEQ))
+			dp->dccps_gar = ackno;
 	} else {
+		unsigned long now = jiffies;
+		/*
+		 *   Step 6: Check sequence numbers
+		 *      Otherwise,
+		 *         If P.type == Reset,
+		 *            Send Sync packet acknowledging S.GSR
+		 *         Otherwise,
+		 *            Send Sync packet acknowledging P.seqno
+		 *      Drop packet and return
+		 *
+		 *   These Syncs are rate-limited as per RFC 4340, 7.5.4:
+		 *   at most 1 / (dccp_sync_rate_limit * HZ) Syncs per second.
+		 */
+		if (time_before(now, (dp->dccps_rate_last +
+				      sysctl_dccp_sync_ratelimit)))
+			return 0;
+
 		DCCP_WARN("DCCP: Step 6 failed for %s packet, "
 			  "(LSWL(%llu) <= P.seqno(%llu) <= S.SWH(%llu)) and "
 			  "(P.ackno %s or LAWL(%llu) <= P.ackno(%llu) <= S.AWH(%llu), "
 			  "sending SYNC...\n",  dccp_packet_name(dh->dccph_type),
-			  (unsigned long long) lswl,
-			  (unsigned long long) DCCP_SKB_CB(skb)->dccpd_seq,
+			  (unsigned long long) lswl, (unsigned long long) seqno,
 			  (unsigned long long) dp->dccps_swh,
-			  (DCCP_SKB_CB(skb)->dccpd_ack_seq ==
-				DCCP_PKT_WITHOUT_ACK_SEQ) ? "doesn't exist" : "exists",
-			  (unsigned long long) lawl,
-			  (unsigned long long) DCCP_SKB_CB(skb)->dccpd_ack_seq,
+			  (ackno == DCCP_PKT_WITHOUT_ACK_SEQ) ? "doesn't exist"
+							      : "exists",
+			  (unsigned long long) lawl, (unsigned long long) ackno,
 			  (unsigned long long) dp->dccps_awh);
-		dccp_send_sync(sk, DCCP_SKB_CB(skb)->dccpd_seq, DCCP_PKT_SYNC);
+
+		dp->dccps_rate_last = now;
+
+		if (dh->dccph_type == DCCP_PKT_RESET)
+			seqno = dp->dccps_gsr;
+		dccp_send_sync(sk, seqno, DCCP_PKT_SYNC);
 		return -1;
 	}
 
@@ -280,6 +293,7 @@ static int dccp_rcv_request_sent_state_process(struct sock *sk,
 	if (dh->dccph_type == DCCP_PKT_RESPONSE) {
 		const struct inet_connection_sock *icsk = inet_csk(sk);
 		struct dccp_sock *dp = dccp_sk(sk);
+		long tstamp = dccp_timestamp();
 
 		/* Stop the REQUEST timer */
 		inet_csk_clear_xmit_timer(sk, ICSK_TIME_RETRANS);
@@ -300,13 +314,10 @@ static int dccp_rcv_request_sent_state_process(struct sock *sk,
 		if (dccp_parse_options(sk, skb))
 			goto out_invalid_packet;
 
-		/* Obtain RTT sample from SYN exchange (used by CCID 3) */
-		if (dp->dccps_options_received.dccpor_timestamp_echo) {
-			struct timeval now;
-
-			dccp_timestamp(sk, &now);
-			dp->dccps_syn_rtt = dccp_sample_rtt(sk, &now, NULL);
-		}
+		/* Obtain usec RTT sample from SYN exchange (used by CCID 3) */
+		if (likely(dp->dccps_options_received.dccpor_timestamp_echo))
+			dp->dccps_syn_rtt = dccp_sample_rtt(sk, 10 * (tstamp -
+			    dp->dccps_options_received.dccpor_timestamp_echo));
 
 		if (dccp_msk(sk)->dccpms_send_ack_vector &&
 		    dccp_ackvec_add(dp->dccps_hc_rx_ackvec, sk,
@@ -540,11 +551,6 @@ int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
 		return 0;
 	}
 
-	if (unlikely(dh->dccph_type == DCCP_PKT_SYNC)) {
-		dccp_send_sync(sk, dcb->dccpd_seq, DCCP_PKT_SYNCACK);
-		goto discard;
-	}
-
 	switch (sk->sk_state) {
 	case DCCP_CLOSED:
 		dcb->dccpd_reset_code = DCCP_RESET_CODE_NO_CONNECTION;
@@ -575,6 +581,9 @@ int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
 			sk_wake_async(sk, 0, POLL_OUT);
 			break;
 		}
+	} else if (unlikely(dh->dccph_type == DCCP_PKT_SYNC)) {
+		dccp_send_sync(sk, dcb->dccpd_seq, DCCP_PKT_SYNCACK);
+		goto discard;
 	}
 
 	if (!queued) {
@@ -587,37 +596,22 @@ discard:
 EXPORT_SYMBOL_GPL(dccp_rcv_state_process);
 
 /**
- * dccp_sample_rtt  -  Sample RTT from packet exchange
- *
- * @sk:     connected dccp_sock
- * @t_recv: receive timestamp of packet with timestamp echo
- * @t_hist: packet history timestamp or NULL
+ *  dccp_sample_rtt  -  Validate and finalise computation of RTT sample
+ *  @delta:	number of microseconds between packet and acknowledgment
+ *  The routine is kept generic to work in different contexts. It should be
+ *  called immediately when the ACK used for the RTT sample arrives.
  */
-u32 dccp_sample_rtt(struct sock *sk, struct timeval *t_recv,
-				     struct timeval *t_hist)
+u32 dccp_sample_rtt(struct sock *sk, long delta)
 {
-	struct dccp_sock *dp = dccp_sk(sk);
-	struct dccp_options_received *or = &dp->dccps_options_received;
-	suseconds_t delta;
-
-	if (t_hist == NULL) {
-		if (!or->dccpor_timestamp_echo) {
-			DCCP_WARN("packet without timestamp echo\n");
-			return DCCP_SANE_RTT_MAX;
-		}
-		timeval_sub_usecs(t_recv, or->dccpor_timestamp_echo * 10);
-		delta = timeval_usecs(t_recv);
-	} else
-		delta = timeval_delta(t_recv, t_hist);
-
-	delta -= or->dccpor_elapsed_time * 10;		/* either set or 0 */
+	/* dccpor_elapsed_time is either zeroed out or set and > 0 */
+	delta -= dccp_sk(sk)->dccps_options_received.dccpor_elapsed_time * 10;
 
 	if (unlikely(delta <= 0)) {
-		DCCP_WARN("unusable RTT sample %ld, using min\n", (long)delta);
+		DCCP_WARN("unusable RTT sample %ld, using min\n", delta);
 		return DCCP_SANE_RTT_MIN;
 	}
-	if (unlikely(delta - (suseconds_t)DCCP_SANE_RTT_MAX > 0)) {
-		DCCP_WARN("RTT sample %ld too large, using max\n", (long)delta);
+	if (unlikely(delta > DCCP_SANE_RTT_MAX)) {
+		DCCP_WARN("RTT sample %ld too large, using max\n", delta);
 		return DCCP_SANE_RTT_MAX;
 	}
 
diff --git a/net/dccp/ipv4.c b/net/dccp/ipv4.c
index 718f2fa923a..44f6e17e105 100644
--- a/net/dccp/ipv4.c
+++ b/net/dccp/ipv4.c
@@ -381,7 +381,6 @@ struct sock *dccp_v4_request_recv_sock(struct sock *sk, struct sk_buff *skb,
 {
 	struct inet_request_sock *ireq;
 	struct inet_sock *newinet;
-	struct dccp_sock *newdp;
 	struct sock *newsk;
 
 	if (sk_acceptq_is_full(sk))
@@ -396,7 +395,6 @@ struct sock *dccp_v4_request_recv_sock(struct sock *sk, struct sk_buff *skb,
 
 	sk_setup_caps(newsk, dst);
 
-	newdp		   = dccp_sk(newsk);
 	newinet		   = inet_sk(newsk);
 	ireq		   = inet_rsk(req);
 	newinet->daddr	   = ireq->rmt_addr;
@@ -512,17 +510,12 @@ out:
 static void dccp_v4_ctl_send_reset(struct sock *sk, struct sk_buff *rxskb)
 {
 	int err;
-	struct dccp_hdr *rxdh = dccp_hdr(rxskb), *dh;
 	const struct iphdr *rxiph;
-	const int dccp_hdr_reset_len = sizeof(struct dccp_hdr) +
-				       sizeof(struct dccp_hdr_ext) +
-				       sizeof(struct dccp_hdr_reset);
 	struct sk_buff *skb;
 	struct dst_entry *dst;
-	u64 seqno = 0;
 
 	/* Never send a reset in response to a reset. */
-	if (rxdh->dccph_type == DCCP_PKT_RESET)
+	if (dccp_hdr(rxskb)->dccph_type == DCCP_PKT_RESET)
 		return;
 
 	if (((struct rtable *)rxskb->dst)->rt_type != RTN_LOCAL)
@@ -532,37 +525,14 @@ static void dccp_v4_ctl_send_reset(struct sock *sk, struct sk_buff *rxskb)
 	if (dst == NULL)
 		return;
 
-	skb = alloc_skb(dccp_v4_ctl_socket->sk->sk_prot->max_header,
-			GFP_ATOMIC);
+	skb = dccp_ctl_make_reset(dccp_v4_ctl_socket, rxskb);
 	if (skb == NULL)
 		goto out;
 
-	/* Reserve space for headers. */
-	skb_reserve(skb, dccp_v4_ctl_socket->sk->sk_prot->max_header);
-	skb->dst = dst_clone(dst);
-
-	dh = dccp_zeroed_hdr(skb, dccp_hdr_reset_len);
-
-	/* Build DCCP header and checksum it. */
-	dh->dccph_type	   = DCCP_PKT_RESET;
-	dh->dccph_sport	   = rxdh->dccph_dport;
-	dh->dccph_dport	   = rxdh->dccph_sport;
-	dh->dccph_doff	   = dccp_hdr_reset_len / 4;
-	dh->dccph_x	   = 1;
-	dccp_hdr_reset(skb)->dccph_reset_code =
-				DCCP_SKB_CB(rxskb)->dccpd_reset_code;
-
-	/* See "8.3.1. Abnormal Termination" in RFC 4340 */
-	if (DCCP_SKB_CB(rxskb)->dccpd_ack_seq != DCCP_PKT_WITHOUT_ACK_SEQ)
-		dccp_set_seqno(&seqno, DCCP_SKB_CB(rxskb)->dccpd_ack_seq + 1);
-
-	dccp_hdr_set_seq(dh, seqno);
-	dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), DCCP_SKB_CB(rxskb)->dccpd_seq);
-
-	dccp_csum_outgoing(skb);
 	rxiph = ip_hdr(rxskb);
-	dh->dccph_checksum = dccp_v4_csum_finish(skb, rxiph->saddr,
-						 rxiph->daddr);
+	dccp_hdr(skb)->dccph_checksum = dccp_v4_csum_finish(skb, rxiph->saddr,
+								 rxiph->daddr);
+	skb->dst = dst_clone(dst);
 
 	bh_lock_sock(dccp_v4_ctl_socket->sk);
 	err = ip_build_and_send_pkt(skb, dccp_v4_ctl_socket->sk,
@@ -598,17 +568,14 @@ int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
 	struct dccp_request_sock *dreq;
 	const __be32 service = dccp_hdr_request(skb)->dccph_req_service;
 	struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
-	__u8 reset_code = DCCP_RESET_CODE_TOO_BUSY;
 
 	/* Never answer to DCCP_PKT_REQUESTs send to broadcast or multicast */
 	if (((struct rtable *)skb->dst)->rt_flags &
-	    (RTCF_BROADCAST | RTCF_MULTICAST)) {
-		reset_code = DCCP_RESET_CODE_NO_CONNECTION;
-		goto drop;
-	}
+	    (RTCF_BROADCAST | RTCF_MULTICAST))
+		return 0;	/* discard, don't send a reset here */
 
 	if (dccp_bad_service_code(sk, service)) {
-		reset_code = DCCP_RESET_CODE_BAD_SERVICE_CODE;
+		dcb->dccpd_reset_code = DCCP_RESET_CODE_BAD_SERVICE_CODE;
 		goto drop;
 	}
 	/*
@@ -616,6 +583,7 @@ int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
 	 * limitations, they conserve resources and peer is
 	 * evidently real one.
 	 */
+	dcb->dccpd_reset_code = DCCP_RESET_CODE_TOO_BUSY;
 	if (inet_csk_reqsk_queue_is_full(sk))
 		goto drop;
 
@@ -668,7 +636,6 @@ drop_and_free:
 	reqsk_free(req);
 drop:
 	DCCP_INC_STATS_BH(DCCP_MIB_ATTEMPTFAILS);
-	dcb->dccpd_reset_code = reset_code;
 	return -1;
 }
 
diff --git a/net/dccp/ipv6.c b/net/dccp/ipv6.c
index b158c661867..006a3834fbc 100644
--- a/net/dccp/ipv6.c
+++ b/net/dccp/ipv6.c
@@ -301,50 +301,23 @@ static void dccp_v6_reqsk_destructor(struct request_sock *req)
 
 static void dccp_v6_ctl_send_reset(struct sock *sk, struct sk_buff *rxskb)
 {
-	struct dccp_hdr *rxdh = dccp_hdr(rxskb), *dh;
 	struct ipv6hdr *rxip6h;
-	const u32 dccp_hdr_reset_len = sizeof(struct dccp_hdr) +
-				       sizeof(struct dccp_hdr_ext) +
-				       sizeof(struct dccp_hdr_reset);
 	struct sk_buff *skb;
 	struct flowi fl;
-	u64 seqno = 0;
 
-	if (rxdh->dccph_type == DCCP_PKT_RESET)
+	if (dccp_hdr(rxskb)->dccph_type == DCCP_PKT_RESET)
 		return;
 
 	if (!ipv6_unicast_destination(rxskb))
 		return;
 
-	skb = alloc_skb(dccp_v6_ctl_socket->sk->sk_prot->max_header,
-			GFP_ATOMIC);
+	skb = dccp_ctl_make_reset(dccp_v6_ctl_socket, rxskb);
 	if (skb == NULL)
 		return;
 
-	skb_reserve(skb, dccp_v6_ctl_socket->sk->sk_prot->max_header);
-
-	dh = dccp_zeroed_hdr(skb, dccp_hdr_reset_len);
-
-	/* Swap the send and the receive. */
-	dh->dccph_type	= DCCP_PKT_RESET;
-	dh->dccph_sport	= rxdh->dccph_dport;
-	dh->dccph_dport	= rxdh->dccph_sport;
-	dh->dccph_doff	= dccp_hdr_reset_len / 4;
-	dh->dccph_x	= 1;
-	dccp_hdr_reset(skb)->dccph_reset_code =
-				DCCP_SKB_CB(rxskb)->dccpd_reset_code;
-
-	/* See "8.3.1. Abnormal Termination" in RFC 4340 */
-	if (DCCP_SKB_CB(rxskb)->dccpd_ack_seq != DCCP_PKT_WITHOUT_ACK_SEQ)
-		dccp_set_seqno(&seqno, DCCP_SKB_CB(rxskb)->dccpd_ack_seq + 1);
-
-	dccp_hdr_set_seq(dh, seqno);
-	dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), DCCP_SKB_CB(rxskb)->dccpd_seq);
-
-	dccp_csum_outgoing(skb);
 	rxip6h = ipv6_hdr(rxskb);
-	dh->dccph_checksum = dccp_v6_csum_finish(skb, &rxip6h->saddr,
-						      &rxip6h->daddr);
+	dccp_hdr(skb)->dccph_checksum = dccp_v6_csum_finish(skb, &rxip6h->saddr,
+							    &rxip6h->daddr);
 
 	memset(&fl, 0, sizeof(fl));
 	ipv6_addr_copy(&fl.fl6_dst, &rxip6h->saddr);
@@ -352,8 +325,8 @@ static void dccp_v6_ctl_send_reset(struct sock *sk, struct sk_buff *rxskb)
 
 	fl.proto = IPPROTO_DCCP;
 	fl.oif = inet6_iif(rxskb);
-	fl.fl_ip_dport = dh->dccph_dport;
-	fl.fl_ip_sport = dh->dccph_sport;
+	fl.fl_ip_dport = dccp_hdr(skb)->dccph_dport;
+	fl.fl_ip_sport = dccp_hdr(skb)->dccph_sport;
 	security_skb_classify_flow(rxskb, &fl);
 
 	/* sk = NULL, but it is safe for now. RST socket required. */
@@ -417,21 +390,21 @@ static int dccp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
 	struct ipv6_pinfo *np = inet6_sk(sk);
 	const __be32 service = dccp_hdr_request(skb)->dccph_req_service;
 	struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
-	__u8 reset_code = DCCP_RESET_CODE_TOO_BUSY;
 
 	if (skb->protocol == htons(ETH_P_IP))
 		return dccp_v4_conn_request(sk, skb);
 
 	if (!ipv6_unicast_destination(skb))
-		goto drop;
+		return 0;	/* discard, don't send a reset here */
 
 	if (dccp_bad_service_code(sk, service)) {
-		reset_code = DCCP_RESET_CODE_BAD_SERVICE_CODE;
+		dcb->dccpd_reset_code = DCCP_RESET_CODE_BAD_SERVICE_CODE;
 		goto drop;
 	}
 	/*
 	 * There are no SYN attacks on IPv6, yet...
 	 */
+	dcb->dccpd_reset_code = DCCP_RESET_CODE_TOO_BUSY;
 	if (inet_csk_reqsk_queue_is_full(sk))
 		goto drop;
 
@@ -491,7 +464,6 @@ drop_and_free:
 	reqsk_free(req);
 drop:
 	DCCP_INC_STATS_BH(DCCP_MIB_ATTEMPTFAILS);
-	dcb->dccpd_reset_code = reset_code;
 	return -1;
 }
 
diff --git a/net/dccp/minisocks.c b/net/dccp/minisocks.c
index e18e249ac49..831b76e08d0 100644
--- a/net/dccp/minisocks.c
+++ b/net/dccp/minisocks.c
@@ -42,6 +42,16 @@ struct inet_timewait_death_row dccp_death_row = {
 
 EXPORT_SYMBOL_GPL(dccp_death_row);
 
+void dccp_minisock_init(struct dccp_minisock *dmsk)
+{
+	dmsk->dccpms_sequence_window = sysctl_dccp_feat_sequence_window;
+	dmsk->dccpms_rx_ccid	     = sysctl_dccp_feat_rx_ccid;
+	dmsk->dccpms_tx_ccid	     = sysctl_dccp_feat_tx_ccid;
+	dmsk->dccpms_ack_ratio	     = sysctl_dccp_feat_ack_ratio;
+	dmsk->dccpms_send_ack_vector = sysctl_dccp_feat_send_ack_vector;
+	dmsk->dccpms_send_ndp_count  = sysctl_dccp_feat_send_ndp_count;
+}
+
 void dccp_time_wait(struct sock *sk, int state, int timeo)
 {
 	struct inet_timewait_sock *tw = NULL;
@@ -112,7 +122,6 @@ struct sock *dccp_create_openreq_child(struct sock *sk,
 		newdp->dccps_service_list  = NULL;
 		newdp->dccps_service	   = dreq->dreq_service;
 		newicsk->icsk_rto	   = DCCP_TIMEOUT_INIT;
-		do_gettimeofday(&newdp->dccps_epoch);
 
 		if (dccp_feat_clone(sk, newsk))
 			goto out_free;
diff --git a/net/dccp/options.c b/net/dccp/options.c
index 34d536d5f1a..d361b553330 100644
--- a/net/dccp/options.c
+++ b/net/dccp/options.c
@@ -29,16 +29,6 @@ int sysctl_dccp_feat_ack_ratio	      = DCCPF_INITIAL_ACK_RATIO;
 int sysctl_dccp_feat_send_ack_vector = DCCPF_INITIAL_SEND_ACK_VECTOR;
 int sysctl_dccp_feat_send_ndp_count  = DCCPF_INITIAL_SEND_NDP_COUNT;
 
-void dccp_minisock_init(struct dccp_minisock *dmsk)
-{
-	dmsk->dccpms_sequence_window = sysctl_dccp_feat_sequence_window;
-	dmsk->dccpms_rx_ccid	     = sysctl_dccp_feat_rx_ccid;
-	dmsk->dccpms_tx_ccid	     = sysctl_dccp_feat_tx_ccid;
-	dmsk->dccpms_ack_ratio	     = sysctl_dccp_feat_ack_ratio;
-	dmsk->dccpms_send_ack_vector = sysctl_dccp_feat_send_ack_vector;
-	dmsk->dccpms_send_ndp_count  = sysctl_dccp_feat_send_ndp_count;
-}
-
 static u32 dccp_decode_value_var(const unsigned char *bf, const u8 len)
 {
 	u32 value = 0;
@@ -158,7 +148,7 @@ int dccp_parse_options(struct sock *sk, struct sk_buff *skb)
 			opt_recv->dccpor_timestamp = ntohl(*(__be32 *)value);
 
 			dp->dccps_timestamp_echo = opt_recv->dccpor_timestamp;
-			dccp_timestamp(sk, &dp->dccps_timestamp_time);
+			dp->dccps_timestamp_time = ktime_get_real();
 
 			dccp_pr_debug("%s rx opt: TIMESTAMP=%u, ackno=%llu\n",
 				      dccp_role(sk), opt_recv->dccpor_timestamp,
@@ -189,7 +179,7 @@ int dccp_parse_options(struct sock *sk, struct sk_buff *skb)
 			else
 				elapsed_time = ntohl(*(__be32 *)(value + 4));
 
-			dccp_pr_debug_cat(", ELAPSED_TIME=%d\n", elapsed_time);
+			dccp_pr_debug_cat(", ELAPSED_TIME=%u\n", elapsed_time);
 
 			/* Give precedence to the biggest ELAPSED_TIME */
 			if (elapsed_time > opt_recv->dccpor_elapsed_time)
@@ -370,29 +360,9 @@ int dccp_insert_option_elapsed_time(struct sock *sk, struct sk_buff *skb,
 
 EXPORT_SYMBOL_GPL(dccp_insert_option_elapsed_time);
 
-void dccp_timestamp(const struct sock *sk, struct timeval *tv)
-{
-	const struct dccp_sock *dp = dccp_sk(sk);
-
-	do_gettimeofday(tv);
-	tv->tv_sec  -= dp->dccps_epoch.tv_sec;
-	tv->tv_usec -= dp->dccps_epoch.tv_usec;
-
-	while (tv->tv_usec < 0) {
-		tv->tv_sec--;
-		tv->tv_usec += USEC_PER_SEC;
-	}
-}
-
-EXPORT_SYMBOL_GPL(dccp_timestamp);
-
 int dccp_insert_option_timestamp(struct sock *sk, struct sk_buff *skb)
 {
-	struct timeval tv;
-	__be32 now;
-
-	dccp_timestamp(sk, &tv);
-	now = htonl(timeval_usecs(&tv) / 10);
+	__be32 now = htonl(dccp_timestamp());
 	/* yes this will overflow but that is the point as we want a
 	 * 10 usec 32 bit timer which mean it wraps every 11.9 hours */
 
@@ -405,14 +375,12 @@ static int dccp_insert_option_timestamp_echo(struct sock *sk,
 					     struct sk_buff *skb)
 {
 	struct dccp_sock *dp = dccp_sk(sk);
-	struct timeval now;
 	__be32 tstamp_echo;
-	u32 elapsed_time;
 	int len, elapsed_time_len;
 	unsigned char *to;
-
-	dccp_timestamp(sk, &now);
-	elapsed_time = timeval_delta(&now, &dp->dccps_timestamp_time) / 10;
+	const suseconds_t delta = ktime_us_delta(ktime_get_real(),
+						 dp->dccps_timestamp_time);
+	u32 elapsed_time = delta / 10;
 	elapsed_time_len = dccp_elapsed_time_len(elapsed_time);
 	len = 6 + elapsed_time_len;
 
@@ -438,8 +406,7 @@ static int dccp_insert_option_timestamp_echo(struct sock *sk,
 	}
 
 	dp->dccps_timestamp_echo = 0;
-	dp->dccps_timestamp_time.tv_sec = 0;
-	dp->dccps_timestamp_time.tv_usec = 0;
+	dp->dccps_timestamp_time = ktime_set(0, 0);
 	return 0;
 }
 
diff --git a/net/dccp/output.c b/net/dccp/output.c
index c8d843e983f..f49544618f2 100644
--- a/net/dccp/output.c
+++ b/net/dccp/output.c
@@ -61,6 +61,7 @@ static int dccp_transmit_skb(struct sock *sk, struct sk_buff *skb)
 			set_ack = 0;
 			/* fall through */
 		case DCCP_PKT_DATAACK:
+		case DCCP_PKT_RESET:
 			break;
 
 		case DCCP_PKT_REQUEST:
@@ -69,12 +70,14 @@ static int dccp_transmit_skb(struct sock *sk, struct sk_buff *skb)
 
 		case DCCP_PKT_SYNC:
 		case DCCP_PKT_SYNCACK:
-			ackno = dcb->dccpd_seq;
+			ackno = dcb->dccpd_ack_seq;
 			/* fall through */
 		default:
 			/*
-			 * Only data packets should come through with skb->sk
-			 * set.
+			 * Set owner/destructor: some skbs are allocated via
+			 * alloc_skb (e.g. when retransmission may happen).
+			 * Only Data, DataAck, and Reset packets should come
+			 * through here with skb->sk set.
 			 */
 			WARN_ON(skb->sk);
 			skb_set_owner_w(skb, sk);
@@ -174,34 +177,38 @@ void dccp_write_space(struct sock *sk)
 
 /**
  * dccp_wait_for_ccid - Wait for ccid to tell us we can send a packet
- * @sk: socket to wait for
+ * @sk:    socket to wait for
+ * @skb:   current skb to pass on for waiting
+ * @delay: sleep timeout in milliseconds (> 0)
+ * This function is called by default when the socket is closed, and
+ * when a non-zero linger time is set on the socket. For consistency
  */
-static int dccp_wait_for_ccid(struct sock *sk, struct sk_buff *skb)
+static int dccp_wait_for_ccid(struct sock *sk, struct sk_buff *skb, int delay)
 {
 	struct dccp_sock *dp = dccp_sk(sk);
 	DEFINE_WAIT(wait);
-	unsigned long delay;
+	unsigned long jiffdelay;
 	int rc;
 
-	while (1) {
+	do {
+		dccp_pr_debug("delayed send by %d msec\n", delay);
+		jiffdelay = msecs_to_jiffies(delay);
+
 		prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
 
+		sk->sk_write_pending++;
+		release_sock(sk);
+		schedule_timeout(jiffdelay);
+		lock_sock(sk);
+		sk->sk_write_pending--;
+
 		if (sk->sk_err)
 			goto do_error;
 		if (signal_pending(current))
 			goto do_interrupted;
 
 		rc = ccid_hc_tx_send_packet(dp->dccps_hc_tx_ccid, sk, skb);
-		if (rc <= 0)
-			break;
-		dccp_pr_debug("delayed send by %d msec\n", rc);
-		delay = msecs_to_jiffies(rc);
-		sk->sk_write_pending++;
-		release_sock(sk);
-		schedule_timeout(delay);
-		lock_sock(sk);
-		sk->sk_write_pending--;
-	}
+	} while ((delay = rc) > 0);
 out:
 	finish_wait(sk->sk_sleep, &wait);
 	return rc;
@@ -228,7 +235,7 @@ void dccp_write_xmit(struct sock *sk, int block)
 						msecs_to_jiffies(err)+jiffies);
 				break;
 			} else
-				err = dccp_wait_for_ccid(sk, skb);
+				err = dccp_wait_for_ccid(sk, skb, err);
 			if (err && err != -EINTR)
 				DCCP_BUG("err=%d after dccp_wait_for_ccid", err);
 		}
@@ -324,72 +331,81 @@ struct sk_buff *dccp_make_response(struct sock *sk, struct dst_entry *dst,
 
 EXPORT_SYMBOL_GPL(dccp_make_response);
 
-static struct sk_buff *dccp_make_reset(struct sock *sk, struct dst_entry *dst,
-				       const enum dccp_reset_codes code)
+/* answer offending packet in @rcv_skb with Reset from control socket @ctl */
+struct sk_buff *dccp_ctl_make_reset(struct socket *ctl, struct sk_buff *rcv_skb)
 {
-	struct dccp_hdr *dh;
-	struct dccp_sock *dp = dccp_sk(sk);
-	const u32 dccp_header_size = sizeof(struct dccp_hdr) +
-				     sizeof(struct dccp_hdr_ext) +
-				     sizeof(struct dccp_hdr_reset);
-	struct sk_buff *skb = sock_wmalloc(sk, sk->sk_prot->max_header, 1,
-					   GFP_ATOMIC);
-	if (skb == NULL)
-		return NULL;
-
-	/* Reserve space for headers. */
-	skb_reserve(skb, sk->sk_prot->max_header);
-
-	skb->dst = dst_clone(dst);
-
-	dccp_inc_seqno(&dp->dccps_gss);
-
-	DCCP_SKB_CB(skb)->dccpd_reset_code = code;
-	DCCP_SKB_CB(skb)->dccpd_type	   = DCCP_PKT_RESET;
-	DCCP_SKB_CB(skb)->dccpd_seq	   = dp->dccps_gss;
+	struct dccp_hdr *rxdh = dccp_hdr(rcv_skb), *dh;
+	struct dccp_skb_cb *dcb = DCCP_SKB_CB(rcv_skb);
+	const u32 dccp_hdr_reset_len = sizeof(struct dccp_hdr) +
+				       sizeof(struct dccp_hdr_ext) +
+				       sizeof(struct dccp_hdr_reset);
+	struct dccp_hdr_reset *dhr;
+	struct sk_buff *skb;
 
-	if (dccp_insert_options(sk, skb)) {
-		kfree_skb(skb);
+	skb = alloc_skb(ctl->sk->sk_prot->max_header, GFP_ATOMIC);
+	if (skb == NULL)
 		return NULL;
-	}
 
-	dh = dccp_zeroed_hdr(skb, dccp_header_size);
+	skb_reserve(skb, ctl->sk->sk_prot->max_header);
 
-	dh->dccph_sport	= inet_sk(sk)->sport;
-	dh->dccph_dport	= inet_sk(sk)->dport;
-	dh->dccph_doff	= (dccp_header_size +
-			   DCCP_SKB_CB(skb)->dccpd_opt_len) / 4;
+	/* Swap the send and the receive. */
+	dh = dccp_zeroed_hdr(skb, dccp_hdr_reset_len);
 	dh->dccph_type	= DCCP_PKT_RESET;
+	dh->dccph_sport	= rxdh->dccph_dport;
+	dh->dccph_dport	= rxdh->dccph_sport;
+	dh->dccph_doff	= dccp_hdr_reset_len / 4;
 	dh->dccph_x	= 1;
-	dccp_hdr_set_seq(dh, dp->dccps_gss);
-	dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), dp->dccps_gsr);
 
-	dccp_hdr_reset(skb)->dccph_reset_code = code;
-	inet_csk(sk)->icsk_af_ops->send_check(sk, 0, skb);
+	dhr = dccp_hdr_reset(skb);
+	dhr->dccph_reset_code = dcb->dccpd_reset_code;
+
+	switch (dcb->dccpd_reset_code) {
+	case DCCP_RESET_CODE_PACKET_ERROR:
+		dhr->dccph_reset_data[0] = rxdh->dccph_type;
+		break;
+	case DCCP_RESET_CODE_OPTION_ERROR:	/* fall through */
+	case DCCP_RESET_CODE_MANDATORY_ERROR:
+		memcpy(dhr->dccph_reset_data, dcb->dccpd_reset_data, 3);
+		break;
+	}
+	/*
+	 * From RFC 4340, 8.3.1:
+	 *   If P.ackno exists, set R.seqno := P.ackno + 1.
+	 *   Else set R.seqno := 0.
+	 */
+	if (dcb->dccpd_ack_seq != DCCP_PKT_WITHOUT_ACK_SEQ)
+		dccp_hdr_set_seq(dh, ADD48(dcb->dccpd_ack_seq, 1));
+	dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), dcb->dccpd_seq);
 
-	DCCP_INC_STATS(DCCP_MIB_OUTSEGS);
+	dccp_csum_outgoing(skb);
 	return skb;
 }
 
+EXPORT_SYMBOL_GPL(dccp_ctl_make_reset);
+
+/* send Reset on established socket, to close or abort the connection */
 int dccp_send_reset(struct sock *sk, enum dccp_reset_codes code)
 {
+	struct sk_buff *skb;
 	/*
 	 * FIXME: what if rebuild_header fails?
 	 * Should we be doing a rebuild_header here?
 	 */
 	int err = inet_sk_rebuild_header(sk);
 
-	if (err == 0) {
-		struct sk_buff *skb = dccp_make_reset(sk, sk->sk_dst_cache,
-						      code);
-		if (skb != NULL) {
-			memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
-			err = inet_csk(sk)->icsk_af_ops->queue_xmit(skb, 0);
-			return net_xmit_eval(err);
-		}
-	}
+	if (err != 0)
+		return err;
+
+	skb = sock_wmalloc(sk, sk->sk_prot->max_header, 1, GFP_ATOMIC);
+	if (skb == NULL)
+		return -ENOBUFS;
 
-	return err;
+	/* Reserve space for headers and prepare control bits. */
+	skb_reserve(skb, sk->sk_prot->max_header);
+	DCCP_SKB_CB(skb)->dccpd_type	   = DCCP_PKT_RESET;
+	DCCP_SKB_CB(skb)->dccpd_reset_code = code;
+
+	return dccp_transmit_skb(sk, skb);
 }
 
 /*
@@ -477,6 +493,7 @@ void dccp_send_ack(struct sock *sk)
 
 EXPORT_SYMBOL_GPL(dccp_send_ack);
 
+/* FIXME: Is this still necessary (11.3) - currently nowhere used by DCCP. */
 void dccp_send_delayed_ack(struct sock *sk)
 {
 	struct inet_connection_sock *icsk = inet_csk(sk);
@@ -507,7 +524,7 @@ void dccp_send_delayed_ack(struct sock *sk)
 	sk_reset_timer(sk, &icsk->icsk_delack_timer, timeout);
 }
 
-void dccp_send_sync(struct sock *sk, const u64 seq,
+void dccp_send_sync(struct sock *sk, const u64 ackno,
 		    const enum dccp_pkt_type pkt_type)
 {
 	/*
@@ -517,14 +534,16 @@ void dccp_send_sync(struct sock *sk, const u64 seq,
 	 */
 	struct sk_buff *skb = alloc_skb(sk->sk_prot->max_header, GFP_ATOMIC);
 
-	if (skb == NULL)
+	if (skb == NULL) {
 		/* FIXME: how to make sure the sync is sent? */
+		DCCP_CRIT("could not send %s", dccp_packet_name(pkt_type));
 		return;
+	}
 
 	/* Reserve space for headers and prepare control bits. */
 	skb_reserve(skb, sk->sk_prot->max_header);
 	DCCP_SKB_CB(skb)->dccpd_type = pkt_type;
-	DCCP_SKB_CB(skb)->dccpd_seq = seq;
+	DCCP_SKB_CB(skb)->dccpd_ack_seq = ackno;
 
 	dccp_transmit_skb(sk, skb);
 }
diff --git a/net/dccp/probe.c b/net/dccp/probe.c
index bae10b0f2fc..7053bb827bc 100644
--- a/net/dccp/probe.c
+++ b/net/dccp/probe.c
@@ -30,6 +30,7 @@
 #include <linux/module.h>
 #include <linux/kfifo.h>
 #include <linux/vmalloc.h>
+#include <net/net_namespace.h>
 
 #include "dccp.h"
 #include "ccid.h"
@@ -168,7 +169,7 @@ static __init int dccpprobe_init(void)
 	if (IS_ERR(dccpw.fifo))
 		return PTR_ERR(dccpw.fifo);
 
-	if (!proc_net_fops_create(procname, S_IRUSR, &dccpprobe_fops))
+	if (!proc_net_fops_create(&init_net, procname, S_IRUSR, &dccpprobe_fops))
 		goto err0;
 
 	ret = register_jprobe(&dccp_send_probe);
@@ -178,7 +179,7 @@ static __init int dccpprobe_init(void)
 	pr_info("DCCP watch registered (port=%d)\n", port);
 	return 0;
 err1:
-	proc_net_remove(procname);
+	proc_net_remove(&init_net, procname);
 err0:
 	kfifo_free(dccpw.fifo);
 	return ret;
@@ -188,7 +189,7 @@ module_init(dccpprobe_init);
 static __exit void dccpprobe_exit(void)
 {
 	kfifo_free(dccpw.fifo);
-	proc_net_remove(procname);
+	proc_net_remove(&init_net, procname);
 	unregister_jprobe(&dccp_send_probe);
 
 }
diff --git a/net/dccp/proto.c b/net/dccp/proto.c
index 04b59ec4f51..cc9bf1cb264 100644
--- a/net/dccp/proto.c
+++ b/net/dccp/proto.c
@@ -172,7 +172,6 @@ int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized)
 	struct inet_connection_sock *icsk = inet_csk(sk);
 
 	dccp_minisock_init(&dp->dccps_minisock);
-	do_gettimeofday(&dp->dccps_epoch);
 
 	/*
 	 * FIXME: We're hardcoding the CCID, and doing this at this point makes
@@ -220,6 +219,7 @@ int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized)
 	sk->sk_write_space	= dccp_write_space;
 	icsk->icsk_sync_mss	= dccp_sync_mss;
 	dp->dccps_mss_cache	= 536;
+	dp->dccps_rate_last	= jiffies;
 	dp->dccps_role		= DCCP_ROLE_UNDEFINED;
 	dp->dccps_service	= DCCP_SERVICE_CODE_IS_ABSENT;
 	dp->dccps_l_ack_ratio	= dp->dccps_r_ack_ratio = 1;
@@ -587,6 +587,10 @@ static int do_dccp_getsockopt(struct sock *sk, int level, int optname,
 	case DCCP_SOCKOPT_SERVICE:
 		return dccp_getsockopt_service(sk, len,
 					       (__be32 __user *)optval, optlen);
+	case DCCP_SOCKOPT_GET_CUR_MPS:
+		val = dp->dccps_mss_cache;
+		len = sizeof(val);
+		break;
 	case DCCP_SOCKOPT_SEND_CSCOV:
 		val = dp->dccps_pcslen;
 		len = sizeof(val);
@@ -664,7 +668,7 @@ int dccp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 	 * so that the trick in dccp_rcv_request_sent_state_process.
 	 */
 	/* Wait for a connection to finish. */
-	if ((1 << sk->sk_state) & ~(DCCPF_OPEN | DCCPF_PARTOPEN | DCCPF_CLOSING))
+	if ((1 << sk->sk_state) & ~(DCCPF_OPEN | DCCPF_PARTOPEN))
 		if ((rc = sk_stream_wait_connect(sk, &timeo)) != 0)
 			goto out_release;
 
@@ -988,7 +992,7 @@ MODULE_PARM_DESC(thash_entries, "Number of ehash buckets");
 
 #ifdef CONFIG_IP_DCCP_DEBUG
 int dccp_debug;
-module_param(dccp_debug, int, 0444);
+module_param(dccp_debug, bool, 0444);
 MODULE_PARM_DESC(dccp_debug, "Enable debug messages");
 
 EXPORT_SYMBOL_GPL(dccp_debug);
@@ -1077,6 +1081,8 @@ static int __init dccp_init(void)
 	rc = dccp_sysctl_init();
 	if (rc)
 		goto out_ackvec_exit;
+
+	dccp_timestamping_init();
 out:
 	return rc;
 out_ackvec_exit:
diff --git a/net/dccp/sysctl.c b/net/dccp/sysctl.c
index 1260aabac5e..9364b2fb4db 100644
--- a/net/dccp/sysctl.c
+++ b/net/dccp/sysctl.c
@@ -18,6 +18,9 @@
 #error This file should not be compiled without CONFIG_SYSCTL defined
 #endif
 
+/* rate-limit for syncs in reply to sequence-invalid packets; RFC 4340, 7.5.4 */
+int sysctl_dccp_sync_ratelimit	__read_mostly = HZ / 8;
+
 static struct ctl_table dccp_default_table[] = {
 	{
 		.procname	= "seq_window",
@@ -89,6 +92,13 @@ static struct ctl_table dccp_default_table[] = {
 		.mode		= 0644,
 		.proc_handler	= proc_dointvec,
 	},
+	{
+		.procname	= "sync_ratelimit",
+		.data		= &sysctl_dccp_sync_ratelimit,
+		.maxlen		= sizeof(sysctl_dccp_sync_ratelimit),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_ms_jiffies,
+	},
 
 	{ .ctl_name = 0, }
 };
diff --git a/net/dccp/timer.c b/net/dccp/timer.c
index 0197a41c256..3af067354bd 100644
--- a/net/dccp/timer.c
+++ b/net/dccp/timer.c
@@ -291,3 +291,24 @@ void dccp_init_xmit_timers(struct sock *sk)
 	inet_csk_init_xmit_timers(sk, &dccp_write_timer, &dccp_delack_timer,
 				  &dccp_keepalive_timer);
 }
+
+static ktime_t dccp_timestamp_seed;
+/**
+ * dccp_timestamp  -  10s of microseconds time source
+ * Returns the number of 10s of microseconds since loading DCCP. This is native
+ * DCCP time difference format (RFC 4340, sec. 13).
+ * Please note: This will wrap around about circa every 11.9 hours.
+ */
+u32 dccp_timestamp(void)
+{
+	s64 delta = ktime_us_delta(ktime_get_real(), dccp_timestamp_seed);
+
+	do_div(delta, 10);
+	return delta;
+}
+EXPORT_SYMBOL_GPL(dccp_timestamp);
+
+void __init dccp_timestamping_init(void)
+{
+	dccp_timestamp_seed = ktime_get_real();
+}