Merge drm/drm-next into drm-intel-next

Sync to v6.16-rc1, among other things to get the fixed size GENMASK_U*()
and BIT_U*() macros.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>

1 files changed, 0 insertions, 794 deletions

diff --git a/net/dccp/ccids/ccid2.c b/net/dccp/ccids/ccid2.c
deleted file mode 100644
index d6b30700af67..000000000000
--- a/net/dccp/ccids/ccid2.c
+++ /dev/null
@@ -1,794 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-or-later
-/*
- *  Copyright (c) 2005, 2006 Andrea Bittau <a.bittau@cs.ucl.ac.uk>
- *
- *  Changes to meet Linux coding standards, and DCCP infrastructure fixes.
- *
- *  Copyright (c) 2006 Arnaldo Carvalho de Melo <acme@conectiva.com.br>
- */
-
-/*
- * This implementation should follow RFC 4341
- */
-#include <linux/slab.h>
-#include "../feat.h"
-#include "ccid2.h"
-
-
-#ifdef CONFIG_IP_DCCP_CCID2_DEBUG
-static bool ccid2_debug;
-#define ccid2_pr_debug(format, a...)	DCCP_PR_DEBUG(ccid2_debug, format, ##a)
-#else
-#define ccid2_pr_debug(format, a...)
-#endif
-
-static int ccid2_hc_tx_alloc_seq(struct ccid2_hc_tx_sock *hc)
-{
-	struct ccid2_seq *seqp;
-	int i;
-
-	/* check if we have space to preserve the pointer to the buffer */
-	if (hc->tx_seqbufc >= (sizeof(hc->tx_seqbuf) /
-			       sizeof(struct ccid2_seq *)))
-		return -ENOMEM;
-
-	/* allocate buffer and initialize linked list */
-	seqp = kmalloc_array(CCID2_SEQBUF_LEN, sizeof(struct ccid2_seq),
-			     gfp_any());
-	if (seqp == NULL)
-		return -ENOMEM;
-
-	for (i = 0; i < (CCID2_SEQBUF_LEN - 1); i++) {
-		seqp[i].ccid2s_next = &seqp[i + 1];
-		seqp[i + 1].ccid2s_prev = &seqp[i];
-	}
-	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 (hc->tx_seqbufc == 0)
-		hc->tx_seqh = hc->tx_seqt = seqp;
-	else {
-		/* link the existing list with the one we just created */
-		hc->tx_seqh->ccid2s_next = seqp;
-		seqp->ccid2s_prev = hc->tx_seqh;
-
-		hc->tx_seqt->ccid2s_prev = &seqp[CCID2_SEQBUF_LEN - 1];
-		seqp[CCID2_SEQBUF_LEN - 1].ccid2s_next = hc->tx_seqt;
-	}
-
-	/* store the original pointer to the buffer so we can free it */
-	hc->tx_seqbuf[hc->tx_seqbufc] = seqp;
-	hc->tx_seqbufc++;
-
-	return 0;
-}
-
-static int ccid2_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb)
-{
-	if (ccid2_cwnd_network_limited(ccid2_hc_tx_sk(sk)))
-		return CCID_PACKET_WILL_DEQUEUE_LATER;
-	return CCID_PACKET_SEND_AT_ONCE;
-}
-
-static void ccid2_change_l_ack_ratio(struct sock *sk, u32 val)
-{
-	u32 max_ratio = DIV_ROUND_UP(ccid2_hc_tx_sk(sk)->tx_cwnd, 2);
-
-	/*
-	 * Ensure that Ack Ratio does not exceed ceil(cwnd/2), which is (2) from
-	 * RFC 4341, 6.1.2. We ignore the statement that Ack Ratio 2 is always
-	 * acceptable since this causes starvation/deadlock whenever cwnd < 2.
-	 * The same problem arises when Ack Ratio is 0 (ie. Ack Ratio disabled).
-	 */
-	if (val == 0 || val > max_ratio) {
-		DCCP_WARN("Limiting Ack Ratio (%u) to %u\n", val, max_ratio);
-		val = max_ratio;
-	}
-	dccp_feat_signal_nn_change(sk, DCCPF_ACK_RATIO,
-				   min_t(u32, val, DCCPF_ACK_RATIO_MAX));
-}
-
-static void ccid2_check_l_ack_ratio(struct sock *sk)
-{
-	struct ccid2_hc_tx_sock *hc = ccid2_hc_tx_sk(sk);
-
-	/*
-	 * After a loss, idle period, application limited period, or RTO we
-	 * need to check that the ack ratio is still less than the congestion
-	 * window. Otherwise, we will send an entire congestion window of
-	 * packets and got no response because we haven't sent ack ratio
-	 * packets yet.
-	 * If the ack ratio does need to be reduced, we reduce it to half of
-	 * the congestion window (or 1 if that's zero) instead of to the
-	 * congestion window. This prevents problems if one ack is lost.
-	 */
-	if (dccp_feat_nn_get(sk, DCCPF_ACK_RATIO) > hc->tx_cwnd)
-		ccid2_change_l_ack_ratio(sk, hc->tx_cwnd/2 ? : 1U);
-}
-
-static void ccid2_change_l_seq_window(struct sock *sk, u64 val)
-{
-	dccp_feat_signal_nn_change(sk, DCCPF_SEQUENCE_WINDOW,
-				   clamp_val(val, DCCPF_SEQ_WMIN,
-						  DCCPF_SEQ_WMAX));
-}
-
-static void dccp_tasklet_schedule(struct sock *sk)
-{
-	struct tasklet_struct *t = &dccp_sk(sk)->dccps_xmitlet;
-
-	if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state)) {
-		sock_hold(sk);
-		__tasklet_schedule(t);
-	}
-}
-
-static void ccid2_hc_tx_rto_expire(struct timer_list *t)
-{
-	struct ccid2_hc_tx_sock *hc = from_timer(hc, t, tx_rtotimer);
-	struct sock *sk = hc->sk;
-	const bool sender_was_blocked = ccid2_cwnd_network_limited(hc);
-
-	bh_lock_sock(sk);
-	if (sock_owned_by_user(sk)) {
-		sk_reset_timer(sk, &hc->tx_rtotimer, jiffies + HZ / 5);
-		goto out;
-	}
-
-	ccid2_pr_debug("RTO_EXPIRE\n");
-
-	if (sk->sk_state == DCCP_CLOSED)
-		goto out;
-
-	/* back-off timer */
-	hc->tx_rto <<= 1;
-	if (hc->tx_rto > DCCP_RTO_MAX)
-		hc->tx_rto = DCCP_RTO_MAX;
-
-	/* adjust pipe, cwnd etc */
-	hc->tx_ssthresh = hc->tx_cwnd / 2;
-	if (hc->tx_ssthresh < 2)
-		hc->tx_ssthresh = 2;
-	hc->tx_cwnd	= 1;
-	hc->tx_pipe	= 0;
-
-	/* clear state about stuff we sent */
-	hc->tx_seqt = hc->tx_seqh;
-	hc->tx_packets_acked = 0;
-
-	/* clear ack ratio state. */
-	hc->tx_rpseq    = 0;
-	hc->tx_rpdupack = -1;
-	ccid2_change_l_ack_ratio(sk, 1);
-
-	/* if we were blocked before, we may now send cwnd=1 packet */
-	if (sender_was_blocked)
-		dccp_tasklet_schedule(sk);
-	/* restart backed-off timer */
-	sk_reset_timer(sk, &hc->tx_rtotimer, jiffies + hc->tx_rto);
-out:
-	bh_unlock_sock(sk);
-	sock_put(sk);
-}
-
-/*
- *	Congestion window validation (RFC 2861).
- */
-static bool ccid2_do_cwv = true;
-module_param(ccid2_do_cwv, bool, 0644);
-MODULE_PARM_DESC(ccid2_do_cwv, "Perform RFC2861 Congestion Window Validation");
-
-/**
- * ccid2_update_used_window  -  Track how much of cwnd is actually used
- * @hc: socket to update window
- * @new_wnd: new window values to add into the filter
- *
- * This is done in addition to CWV. The sender needs to have an idea of how many
- * packets may be in flight, to set the local Sequence Window value accordingly
- * (RFC 4340, 7.5.2). The CWV mechanism is exploited to keep track of the
- * maximum-used window. We use an EWMA low-pass filter to filter out noise.
- */
-static void ccid2_update_used_window(struct ccid2_hc_tx_sock *hc, u32 new_wnd)
-{
-	hc->tx_expected_wnd = (3 * hc->tx_expected_wnd + new_wnd) / 4;
-}
-
-/* This borrows the code of tcp_cwnd_application_limited() */
-static void ccid2_cwnd_application_limited(struct sock *sk, const u32 now)
-{
-	struct ccid2_hc_tx_sock *hc = ccid2_hc_tx_sk(sk);
-	/* don't reduce cwnd below the initial window (IW) */
-	u32 init_win = rfc3390_bytes_to_packets(dccp_sk(sk)->dccps_mss_cache),
-	    win_used = max(hc->tx_cwnd_used, init_win);
-
-	if (win_used < hc->tx_cwnd) {
-		hc->tx_ssthresh = max(hc->tx_ssthresh,
-				     (hc->tx_cwnd >> 1) + (hc->tx_cwnd >> 2));
-		hc->tx_cwnd = (hc->tx_cwnd + win_used) >> 1;
-	}
-	hc->tx_cwnd_used  = 0;
-	hc->tx_cwnd_stamp = now;
-
-	ccid2_check_l_ack_ratio(sk);
-}
-
-/* This borrows the code of tcp_cwnd_restart() */
-static void ccid2_cwnd_restart(struct sock *sk, const u32 now)
-{
-	struct ccid2_hc_tx_sock *hc = ccid2_hc_tx_sk(sk);
-	u32 cwnd = hc->tx_cwnd, restart_cwnd,
-	    iwnd = rfc3390_bytes_to_packets(dccp_sk(sk)->dccps_mss_cache);
-	s32 delta = now - hc->tx_lsndtime;
-
-	hc->tx_ssthresh = max(hc->tx_ssthresh, (cwnd >> 1) + (cwnd >> 2));
-
-	/* don't reduce cwnd below the initial window (IW) */
-	restart_cwnd = min(cwnd, iwnd);
-
-	while ((delta -= hc->tx_rto) >= 0 && cwnd > restart_cwnd)
-		cwnd >>= 1;
-	hc->tx_cwnd = max(cwnd, restart_cwnd);
-	hc->tx_cwnd_stamp = now;
-	hc->tx_cwnd_used  = 0;
-
-	ccid2_check_l_ack_ratio(sk);
-}
-
-static void ccid2_hc_tx_packet_sent(struct sock *sk, unsigned int len)
-{
-	struct dccp_sock *dp = dccp_sk(sk);
-	struct ccid2_hc_tx_sock *hc = ccid2_hc_tx_sk(sk);
-	const u32 now = ccid2_jiffies32;
-	struct ccid2_seq *next;
-
-	/* slow-start after idle periods (RFC 2581, RFC 2861) */
-	if (ccid2_do_cwv && !hc->tx_pipe &&
-	    (s32)(now - hc->tx_lsndtime) >= hc->tx_rto)
-		ccid2_cwnd_restart(sk, now);
-
-	hc->tx_lsndtime = now;
-	hc->tx_pipe    += 1;
-
-	/* see whether cwnd was fully used (RFC 2861), update expected window */
-	if (ccid2_cwnd_network_limited(hc)) {
-		ccid2_update_used_window(hc, hc->tx_cwnd);
-		hc->tx_cwnd_used  = 0;
-		hc->tx_cwnd_stamp = now;
-	} else {
-		if (hc->tx_pipe > hc->tx_cwnd_used)
-			hc->tx_cwnd_used = hc->tx_pipe;
-
-		ccid2_update_used_window(hc, hc->tx_cwnd_used);
-
-		if (ccid2_do_cwv && (s32)(now - hc->tx_cwnd_stamp) >= hc->tx_rto)
-			ccid2_cwnd_application_limited(sk, now);
-	}
-
-	hc->tx_seqh->ccid2s_seq   = dp->dccps_gss;
-	hc->tx_seqh->ccid2s_acked = 0;
-	hc->tx_seqh->ccid2s_sent  = now;
-
-	next = hc->tx_seqh->ccid2s_next;
-	/* check if we need to alloc more space */
-	if (next == hc->tx_seqt) {
-		if (ccid2_hc_tx_alloc_seq(hc)) {
-			DCCP_CRIT("packet history - out of memory!");
-			/* FIXME: find a more graceful way to bail out */
-			return;
-		}
-		next = hc->tx_seqh->ccid2s_next;
-		BUG_ON(next == hc->tx_seqt);
-	}
-	hc->tx_seqh = next;
-
-	ccid2_pr_debug("cwnd=%d pipe=%d\n", hc->tx_cwnd, hc->tx_pipe);
-
-	/*
-	 * FIXME: The code below is broken and the variables have been removed
-	 * from the socket struct. The `ackloss' variable was always set to 0,
-	 * and with arsent there are several problems:
-	 *  (i) it doesn't just count the number of Acks, but all sent packets;
-	 *  (ii) it is expressed in # of packets, not # of windows, so the
-	 *  comparison below uses the wrong formula: Appendix A of RFC 4341
-	 *  comes up with the number K = cwnd / (R^2 - R) of consecutive windows
-	 *  of data with no lost or marked Ack packets. If arsent were the # of
-	 *  consecutive Acks received without loss, then Ack Ratio needs to be
-	 *  decreased by 1 when
-	 *	      arsent >=  K * cwnd / R  =  cwnd^2 / (R^3 - R^2)
-	 *  where cwnd / R is the number of Acks received per window of data
-	 *  (cf. RFC 4341, App. A). The problems are that
-	 *  - arsent counts other packets as well;
-	 *  - the comparison uses a formula different from RFC 4341;
-	 *  - computing a cubic/quadratic equation each time is too complicated.
-	 *  Hence a different algorithm is needed.
-	 */
-#if 0
-	/* Ack Ratio.  Need to maintain a concept of how many windows we sent */
-	hc->tx_arsent++;
-	/* We had an ack loss in this window... */
-	if (hc->tx_ackloss) {
-		if (hc->tx_arsent >= hc->tx_cwnd) {
-			hc->tx_arsent  = 0;
-			hc->tx_ackloss = 0;
-		}
-	} else {
-		/* No acks lost up to now... */
-		/* decrease ack ratio if enough packets were sent */
-		if (dp->dccps_l_ack_ratio > 1) {
-			/* XXX don't calculate denominator each time */
-			int denom = dp->dccps_l_ack_ratio * dp->dccps_l_ack_ratio -
-				    dp->dccps_l_ack_ratio;
-
-			denom = hc->tx_cwnd * hc->tx_cwnd / denom;
-
-			if (hc->tx_arsent >= denom) {
-				ccid2_change_l_ack_ratio(sk, dp->dccps_l_ack_ratio - 1);
-				hc->tx_arsent = 0;
-			}
-		} else {
-			/* we can't increase ack ratio further [1] */
-			hc->tx_arsent = 0; /* or maybe set it to cwnd*/
-		}
-	}
-#endif
-
-	sk_reset_timer(sk, &hc->tx_rtotimer, jiffies + hc->tx_rto);
-
-#ifdef CONFIG_IP_DCCP_CCID2_DEBUG
-	do {
-		struct ccid2_seq *seqp = hc->tx_seqt;
-
-		while (seqp != hc->tx_seqh) {
-			ccid2_pr_debug("out seq=%llu acked=%d time=%u\n",
-				       (unsigned long long)seqp->ccid2s_seq,
-				       seqp->ccid2s_acked, seqp->ccid2s_sent);
-			seqp = seqp->ccid2s_next;
-		}
-	} while (0);
-	ccid2_pr_debug("=========\n");
-#endif
-}
-
-/**
- * ccid2_rtt_estimator - Sample RTT and compute RTO using RFC2988 algorithm
- * @sk: socket to perform estimator on
- * @mrtt: measured RTT
- *
- * This code is almost identical with TCP's tcp_rtt_estimator(), since
- * - it has a higher sampling frequency (recommended by RFC 1323),
- * - the RTO does not collapse into RTT due to RTTVAR going towards zero,
- * - it is simple (cf. more complex proposals such as Eifel timer or research
- *   which suggests that the gain should be set according to window size),
- * - in tests it was found to work well with CCID2 [gerrit].
- */
-static void ccid2_rtt_estimator(struct sock *sk, const long mrtt)
-{
-	struct ccid2_hc_tx_sock *hc = ccid2_hc_tx_sk(sk);
-	long m = mrtt ? : 1;
-
-	if (hc->tx_srtt == 0) {
-		/* First measurement m */
-		hc->tx_srtt = m << 3;
-		hc->tx_mdev = m << 1;
-
-		hc->tx_mdev_max = max(hc->tx_mdev, tcp_rto_min(sk));
-		hc->tx_rttvar   = hc->tx_mdev_max;
-
-		hc->tx_rtt_seq  = dccp_sk(sk)->dccps_gss;
-	} else {
-		/* Update scaled SRTT as SRTT += 1/8 * (m - SRTT) */
-		m -= (hc->tx_srtt >> 3);
-		hc->tx_srtt += m;
-
-		/* Similarly, update scaled mdev with regard to |m| */
-		if (m < 0) {
-			m = -m;
-			m -= (hc->tx_mdev >> 2);
-			/*
-			 * This neutralises RTO increase when RTT < SRTT - mdev
-			 * (see P. Sarolahti, A. Kuznetsov,"Congestion Control
-			 * in Linux TCP", USENIX 2002, pp. 49-62).
-			 */
-			if (m > 0)
-				m >>= 3;
-		} else {
-			m -= (hc->tx_mdev >> 2);
-		}
-		hc->tx_mdev += m;
-
-		if (hc->tx_mdev > hc->tx_mdev_max) {
-			hc->tx_mdev_max = hc->tx_mdev;
-			if (hc->tx_mdev_max > hc->tx_rttvar)
-				hc->tx_rttvar = hc->tx_mdev_max;
-		}
-
-		/*
-		 * Decay RTTVAR at most once per flight, exploiting that
-		 *  1) pipe <= cwnd <= Sequence_Window = W  (RFC 4340, 7.5.2)
-		 *  2) AWL = GSS-W+1 <= GAR <= GSS          (RFC 4340, 7.5.1)
-		 * GAR is a useful bound for FlightSize = pipe.
-		 * AWL is probably too low here, as it over-estimates pipe.
-		 */
-		if (after48(dccp_sk(sk)->dccps_gar, hc->tx_rtt_seq)) {
-			if (hc->tx_mdev_max < hc->tx_rttvar)
-				hc->tx_rttvar -= (hc->tx_rttvar -
-						  hc->tx_mdev_max) >> 2;
-			hc->tx_rtt_seq  = dccp_sk(sk)->dccps_gss;
-			hc->tx_mdev_max = tcp_rto_min(sk);
-		}
-	}
-
-	/*
-	 * Set RTO from SRTT and RTTVAR
-	 * As in TCP, 4 * RTTVAR >= TCP_RTO_MIN, giving a minimum RTO of 200 ms.
-	 * This agrees with RFC 4341, 5:
-	 *	"Because DCCP does not retransmit data, DCCP does not require
-	 *	 TCP's recommended minimum timeout of one second".
-	 */
-	hc->tx_rto = (hc->tx_srtt >> 3) + hc->tx_rttvar;
-
-	if (hc->tx_rto > DCCP_RTO_MAX)
-		hc->tx_rto = DCCP_RTO_MAX;
-}
-
-static void ccid2_new_ack(struct sock *sk, struct ccid2_seq *seqp,
-			  unsigned int *maxincr)
-{
-	struct ccid2_hc_tx_sock *hc = ccid2_hc_tx_sk(sk);
-	struct dccp_sock *dp = dccp_sk(sk);
-	int r_seq_used = hc->tx_cwnd / dp->dccps_l_ack_ratio;
-
-	if (hc->tx_cwnd < dp->dccps_l_seq_win &&
-	    r_seq_used < dp->dccps_r_seq_win) {
-		if (hc->tx_cwnd < hc->tx_ssthresh) {
-			if (*maxincr > 0 && ++hc->tx_packets_acked >= 2) {
-				hc->tx_cwnd += 1;
-				*maxincr    -= 1;
-				hc->tx_packets_acked = 0;
-			}
-		} else if (++hc->tx_packets_acked >= hc->tx_cwnd) {
-			hc->tx_cwnd += 1;
-			hc->tx_packets_acked = 0;
-		}
-	}
-
-	/*
-	 * Adjust the local sequence window and the ack ratio to allow about
-	 * 5 times the number of packets in the network (RFC 4340 7.5.2)
-	 */
-	if (r_seq_used * CCID2_WIN_CHANGE_FACTOR >= dp->dccps_r_seq_win)
-		ccid2_change_l_ack_ratio(sk, dp->dccps_l_ack_ratio * 2);
-	else if (r_seq_used * CCID2_WIN_CHANGE_FACTOR < dp->dccps_r_seq_win/2)
-		ccid2_change_l_ack_ratio(sk, dp->dccps_l_ack_ratio / 2 ? : 1U);
-
-	if (hc->tx_cwnd * CCID2_WIN_CHANGE_FACTOR >= dp->dccps_l_seq_win)
-		ccid2_change_l_seq_window(sk, dp->dccps_l_seq_win * 2);
-	else if (hc->tx_cwnd * CCID2_WIN_CHANGE_FACTOR < dp->dccps_l_seq_win/2)
-		ccid2_change_l_seq_window(sk, dp->dccps_l_seq_win / 2);
-
-	/*
-	 * FIXME: RTT is sampled several times per acknowledgment (for each
-	 * entry in the Ack Vector), instead of once per Ack (as in TCP SACK).
-	 * This causes the RTT to be over-estimated, since the older entries
-	 * in the Ack Vector have earlier sending times.
-	 * The cleanest solution is to not use the ccid2s_sent field at all
-	 * and instead use DCCP timestamps: requires changes in other places.
-	 */
-	ccid2_rtt_estimator(sk, ccid2_jiffies32 - seqp->ccid2s_sent);
-}
-
-static void ccid2_congestion_event(struct sock *sk, struct ccid2_seq *seqp)
-{
-	struct ccid2_hc_tx_sock *hc = ccid2_hc_tx_sk(sk);
-
-	if ((s32)(seqp->ccid2s_sent - hc->tx_last_cong) < 0) {
-		ccid2_pr_debug("Multiple losses in an RTT---treating as one\n");
-		return;
-	}
-
-	hc->tx_last_cong = ccid2_jiffies32;
-
-	hc->tx_cwnd      = hc->tx_cwnd / 2 ? : 1U;
-	hc->tx_ssthresh  = max(hc->tx_cwnd, 2U);
-
-	ccid2_check_l_ack_ratio(sk);
-}
-
-static int ccid2_hc_tx_parse_options(struct sock *sk, u8 packet_type,
-				     u8 option, u8 *optval, u8 optlen)
-{
-	struct ccid2_hc_tx_sock *hc = ccid2_hc_tx_sk(sk);
-
-	switch (option) {
-	case DCCPO_ACK_VECTOR_0:
-	case DCCPO_ACK_VECTOR_1:
-		return dccp_ackvec_parsed_add(&hc->tx_av_chunks, optval, optlen,
-					      option - DCCPO_ACK_VECTOR_0);
-	}
-	return 0;
-}
-
-static void ccid2_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb)
-{
-	struct dccp_sock *dp = dccp_sk(sk);
-	struct ccid2_hc_tx_sock *hc = ccid2_hc_tx_sk(sk);
-	const bool sender_was_blocked = ccid2_cwnd_network_limited(hc);
-	struct dccp_ackvec_parsed *avp;
-	u64 ackno, seqno;
-	struct ccid2_seq *seqp;
-	int done = 0;
-	unsigned int maxincr = 0;
-
-	/* check reverse path congestion */
-	seqno = DCCP_SKB_CB(skb)->dccpd_seq;
-
-	/* XXX this whole "algorithm" is broken.  Need to fix it to keep track
-	 * of the seqnos of the dupacks so that rpseq and rpdupack are correct
-	 * -sorbo.
-	 */
-	/* need to bootstrap */
-	if (hc->tx_rpdupack == -1) {
-		hc->tx_rpdupack = 0;
-		hc->tx_rpseq    = seqno;
-	} else {
-		/* check if packet is consecutive */
-		if (dccp_delta_seqno(hc->tx_rpseq, seqno) == 1)
-			hc->tx_rpseq = seqno;
-		/* it's a later packet */
-		else if (after48(seqno, hc->tx_rpseq)) {
-			hc->tx_rpdupack++;
-
-			/* check if we got enough dupacks */
-			if (hc->tx_rpdupack >= NUMDUPACK) {
-				hc->tx_rpdupack = -1; /* XXX lame */
-				hc->tx_rpseq    = 0;
-#ifdef __CCID2_COPES_GRACEFULLY_WITH_ACK_CONGESTION_CONTROL__
-				/*
-				 * FIXME: Ack Congestion Control is broken; in
-				 * the current state instabilities occurred with
-				 * Ack Ratios greater than 1; causing hang-ups
-				 * and long RTO timeouts. This needs to be fixed
-				 * before opening up dynamic changes. -- gerrit
-				 */
-				ccid2_change_l_ack_ratio(sk, 2 * dp->dccps_l_ack_ratio);
-#endif
-			}
-		}
-	}
-
-	/* check forward path congestion */
-	if (dccp_packet_without_ack(skb))
-		return;
-
-	/* still didn't send out new data packets */
-	if (hc->tx_seqh == hc->tx_seqt)
-		goto done;
-
-	ackno = DCCP_SKB_CB(skb)->dccpd_ack_seq;
-	if (after48(ackno, hc->tx_high_ack))
-		hc->tx_high_ack = ackno;
-
-	seqp = hc->tx_seqt;
-	while (before48(seqp->ccid2s_seq, ackno)) {
-		seqp = seqp->ccid2s_next;
-		if (seqp == hc->tx_seqh) {
-			seqp = hc->tx_seqh->ccid2s_prev;
-			break;
-		}
-	}
-
-	/*
-	 * In slow-start, cwnd can increase up to a maximum of Ack Ratio/2
-	 * packets per acknowledgement. Rounding up avoids that cwnd is not
-	 * advanced when Ack Ratio is 1 and gives a slight edge otherwise.
-	 */
-	if (hc->tx_cwnd < hc->tx_ssthresh)
-		maxincr = DIV_ROUND_UP(dp->dccps_l_ack_ratio, 2);
-
-	/* go through all ack vectors */
-	list_for_each_entry(avp, &hc->tx_av_chunks, node) {
-		/* go through this ack vector */
-		for (; avp->len--; avp->vec++) {
-			u64 ackno_end_rl = SUB48(ackno,
-						 dccp_ackvec_runlen(avp->vec));
-
-			ccid2_pr_debug("ackvec %llu |%u,%u|\n",
-				       (unsigned long long)ackno,
-				       dccp_ackvec_state(avp->vec) >> 6,
-				       dccp_ackvec_runlen(avp->vec));
-			/* if the seqno we are analyzing is larger than the
-			 * current ackno, then move towards the tail of our
-			 * seqnos.
-			 */
-			while (after48(seqp->ccid2s_seq, ackno)) {
-				if (seqp == hc->tx_seqt) {
-					done = 1;
-					break;
-				}
-				seqp = seqp->ccid2s_prev;
-			}
-			if (done)
-				break;
-
-			/* check all seqnos in the range of the vector
-			 * run length
-			 */
-			while (between48(seqp->ccid2s_seq,ackno_end_rl,ackno)) {
-				const u8 state = dccp_ackvec_state(avp->vec);
-
-				/* new packet received or marked */
-				if (state != DCCPAV_NOT_RECEIVED &&
-				    !seqp->ccid2s_acked) {
-					if (state == DCCPAV_ECN_MARKED)
-						ccid2_congestion_event(sk,
-								       seqp);
-					else
-						ccid2_new_ack(sk, seqp,
-							      &maxincr);
-
-					seqp->ccid2s_acked = 1;
-					ccid2_pr_debug("Got ack for %llu\n",
-						       (unsigned long long)seqp->ccid2s_seq);
-					hc->tx_pipe--;
-				}
-				if (seqp == hc->tx_seqt) {
-					done = 1;
-					break;
-				}
-				seqp = seqp->ccid2s_prev;
-			}
-			if (done)
-				break;
-
-			ackno = SUB48(ackno_end_rl, 1);
-		}
-		if (done)
-			break;
-	}
-
-	/* The state about what is acked should be correct now
-	 * Check for NUMDUPACK
-	 */
-	seqp = hc->tx_seqt;
-	while (before48(seqp->ccid2s_seq, hc->tx_high_ack)) {
-		seqp = seqp->ccid2s_next;
-		if (seqp == hc->tx_seqh) {
-			seqp = hc->tx_seqh->ccid2s_prev;
-			break;
-		}
-	}
-	done = 0;
-	while (1) {
-		if (seqp->ccid2s_acked) {
-			done++;
-			if (done == NUMDUPACK)
-				break;
-		}
-		if (seqp == hc->tx_seqt)
-			break;
-		seqp = seqp->ccid2s_prev;
-	}
-
-	/* If there are at least 3 acknowledgements, anything unacknowledged
-	 * below the last sequence number is considered lost
-	 */
-	if (done == NUMDUPACK) {
-		struct ccid2_seq *last_acked = seqp;
-
-		/* check for lost packets */
-		while (1) {
-			if (!seqp->ccid2s_acked) {
-				ccid2_pr_debug("Packet lost: %llu\n",
-					       (unsigned long long)seqp->ccid2s_seq);
-				/* XXX need to traverse from tail -> head in
-				 * order to detect multiple congestion events in
-				 * one ack vector.
-				 */
-				ccid2_congestion_event(sk, seqp);
-				hc->tx_pipe--;
-			}
-			if (seqp == hc->tx_seqt)
-				break;
-			seqp = seqp->ccid2s_prev;
-		}
-
-		hc->tx_seqt = last_acked;
-	}
-
-	/* trim acked packets in tail */
-	while (hc->tx_seqt != hc->tx_seqh) {
-		if (!hc->tx_seqt->ccid2s_acked)
-			break;
-
-		hc->tx_seqt = hc->tx_seqt->ccid2s_next;
-	}
-
-	/* restart RTO timer if not all outstanding data has been acked */
-	if (hc->tx_pipe == 0)
-		sk_stop_timer(sk, &hc->tx_rtotimer);
-	else
-		sk_reset_timer(sk, &hc->tx_rtotimer, jiffies + hc->tx_rto);
-done:
-	/* check if incoming Acks allow pending packets to be sent */
-	if (sender_was_blocked && !ccid2_cwnd_network_limited(hc))
-		dccp_tasklet_schedule(sk);
-	dccp_ackvec_parsed_cleanup(&hc->tx_av_chunks);
-}
-
-static int ccid2_hc_tx_init(struct ccid *ccid, struct sock *sk)
-{
-	struct ccid2_hc_tx_sock *hc = ccid_priv(ccid);
-	struct dccp_sock *dp = dccp_sk(sk);
-	u32 max_ratio;
-
-	/* RFC 4341, 5: initialise ssthresh to arbitrarily high (max) value */
-	hc->tx_ssthresh = ~0U;
-
-	/* Use larger initial windows (RFC 4341, section 5). */
-	hc->tx_cwnd = rfc3390_bytes_to_packets(dp->dccps_mss_cache);
-	hc->tx_expected_wnd = hc->tx_cwnd;
-
-	/* Make sure that Ack Ratio is enabled and within bounds. */
-	max_ratio = DIV_ROUND_UP(hc->tx_cwnd, 2);
-	if (dp->dccps_l_ack_ratio == 0 || dp->dccps_l_ack_ratio > max_ratio)
-		dp->dccps_l_ack_ratio = max_ratio;
-
-	/* XXX init ~ to window size... */
-	if (ccid2_hc_tx_alloc_seq(hc))
-		return -ENOMEM;
-
-	hc->tx_rto	 = DCCP_TIMEOUT_INIT;
-	hc->tx_rpdupack  = -1;
-	hc->tx_last_cong = hc->tx_lsndtime = hc->tx_cwnd_stamp = ccid2_jiffies32;
-	hc->tx_cwnd_used = 0;
-	hc->sk		 = sk;
-	timer_setup(&hc->tx_rtotimer, ccid2_hc_tx_rto_expire, 0);
-	INIT_LIST_HEAD(&hc->tx_av_chunks);
-	return 0;
-}
-
-static void ccid2_hc_tx_exit(struct sock *sk)
-{
-	struct ccid2_hc_tx_sock *hc = ccid2_hc_tx_sk(sk);
-	int i;
-
-	sk_stop_timer(sk, &hc->tx_rtotimer);
-
-	for (i = 0; i < hc->tx_seqbufc; i++)
-		kfree(hc->tx_seqbuf[i]);
-	hc->tx_seqbufc = 0;
-	dccp_ackvec_parsed_cleanup(&hc->tx_av_chunks);
-}
-
-static void ccid2_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb)
-{
-	struct ccid2_hc_rx_sock *hc = ccid2_hc_rx_sk(sk);
-
-	if (!dccp_data_packet(skb))
-		return;
-
-	if (++hc->rx_num_data_pkts >= dccp_sk(sk)->dccps_r_ack_ratio) {
-		dccp_send_ack(sk);
-		hc->rx_num_data_pkts = 0;
-	}
-}
-
-struct ccid_operations ccid2_ops = {
-	.ccid_id		  = DCCPC_CCID2,
-	.ccid_name		  = "TCP-like",
-	.ccid_hc_tx_obj_size	  = sizeof(struct ccid2_hc_tx_sock),
-	.ccid_hc_tx_init	  = ccid2_hc_tx_init,
-	.ccid_hc_tx_exit	  = ccid2_hc_tx_exit,
-	.ccid_hc_tx_send_packet	  = ccid2_hc_tx_send_packet,
-	.ccid_hc_tx_packet_sent	  = ccid2_hc_tx_packet_sent,
-	.ccid_hc_tx_parse_options = ccid2_hc_tx_parse_options,
-	.ccid_hc_tx_packet_recv	  = ccid2_hc_tx_packet_recv,
-	.ccid_hc_rx_obj_size	  = sizeof(struct ccid2_hc_rx_sock),
-	.ccid_hc_rx_packet_recv	  = ccid2_hc_rx_packet_recv,
-};
-
-#ifdef CONFIG_IP_DCCP_CCID2_DEBUG
-module_param(ccid2_debug, bool, 0644);
-MODULE_PARM_DESC(ccid2_debug, "Enable CCID-2 debug messages");
-#endif