From 2a91aa3967398fb94eccc8da67c82bce9f67afdf Mon Sep 17 00:00:00 2001
From: Andrea Bittau <a.bittau@cs.ucl.ac.uk>
Date: Mon, 20 Mar 2006 17:41:47 -0800
Subject: [DCCP] CCID2: Initial CCID2 (TCP-Like) implementation

Original work by Andrea Bittau, Arnaldo Melo cleaned up and fixed several
issues on the merge process.

For now CCID2 was turned the default for all SOCK_DCCP connections, but this
will be remedied soon with the merge of the feature negotiation code.

Signed-off-by: Andrea Bittau <a.bittau@cs.ucl.ac.uk>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 net/dccp/ccids/ccid2.c | 838 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 838 insertions(+)
 create mode 100644 net/dccp/ccids/ccid2.c

(limited to 'net/dccp/ccids/ccid2.c')

diff --git a/net/dccp/ccids/ccid2.c b/net/dccp/ccids/ccid2.c
new file mode 100644
index 00000000000..4a7b8751256
--- /dev/null
+++ b/net/dccp/ccids/ccid2.c
@@ -0,0 +1,838 @@
+/*
+ *  net/dccp/ccids/ccid2.c
+ *
+ *  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 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.
+ */
+
+/*
+ * This implementation should follow: draft-ietf-dccp-ccid2-10.txt
+ *
+ * BUGS:
+ * - sequence number wrapping
+ * - jiffies wrapping
+ */
+
+#include <linux/config.h>
+#include "../ccid.h"
+#include "../dccp.h"
+#include "ccid2.h"
+
+static int ccid2_debug;
+
+#if 0
+#define CCID2_DEBUG
+#endif
+
+#ifdef CCID2_DEBUG
+#define ccid2_pr_debug(format, a...) \
+        do { if (ccid2_debug) \
+                printk(KERN_DEBUG "%s: " format, __FUNCTION__, ##a); \
+        } while (0)
+#else
+#define ccid2_pr_debug(format, a...)
+#endif
+
+static const int ccid2_seq_len = 128;
+
+static inline struct ccid2_hc_tx_sock *ccid2_hc_tx_sk(const struct sock *sk)
+{
+	return dccp_sk(sk)->dccps_hc_tx_ccid_private;
+}
+
+static inline struct ccid2_hc_rx_sock *ccid2_hc_rx_sk(const struct sock *sk)
+{
+	return dccp_sk(sk)->dccps_hc_rx_ccid_private;
+}
+
+#ifdef CCID2_DEBUG
+static void ccid2_hc_tx_check_sanity(const struct ccid2_hc_tx_sock *hctx)
+{
+	int len = 0;
+	struct ccid2_seq *seqp;
+	int pipe = 0;
+
+	seqp = hctx->ccid2hctx_seqh;
+
+	/* there is data in the chain */
+	if (seqp != hctx->ccid2hctx_seqt) {
+		seqp = seqp->ccid2s_prev;
+		len++;
+		if (!seqp->ccid2s_acked)
+			pipe++;
+
+		while (seqp != hctx->ccid2hctx_seqt) {
+			struct ccid2_seq *prev;
+
+			prev = seqp->ccid2s_prev;
+			len++;
+			if (!prev->ccid2s_acked)
+				pipe++;
+
+			/* packets are sent sequentially */
+			BUG_ON(seqp->ccid2s_seq <= prev->ccid2s_seq);
+			BUG_ON(seqp->ccid2s_sent < prev->ccid2s_sent);
+			BUG_ON(len > ccid2_seq_len);
+
+			seqp = prev;
+		}
+	}
+
+	BUG_ON(pipe != hctx->ccid2hctx_pipe);
+	ccid2_pr_debug("len of chain=%d\n", len);
+
+	do {
+		seqp = seqp->ccid2s_prev;
+		len++;
+		BUG_ON(len > ccid2_seq_len);
+	} while(seqp != hctx->ccid2hctx_seqh);
+
+	BUG_ON(len != ccid2_seq_len);
+	ccid2_pr_debug("total len=%d\n", len);
+}
+#else
+#define ccid2_hc_tx_check_sanity(hctx) do {} while (0)
+#endif
+
+static int ccid2_hc_tx_send_packet(struct sock *sk,
+				   struct sk_buff *skb, int len)
+{
+	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);
+
+	ccid2_pr_debug("pipe=%d cwnd=%d\n", hctx->ccid2hctx_pipe,
+		       hctx->ccid2hctx_cwnd);
+
+	if (hctx->ccid2hctx_pipe < hctx->ccid2hctx_cwnd) {
+		/* OK we can send... make sure previous packet was sent off */
+		if (!hctx->ccid2hctx_sendwait) {
+			hctx->ccid2hctx_sendwait = 1;
+			return 0;
+		}
+	}
+
+	return 100; /* XXX */
+}
+
+static void ccid2_change_l_ack_ratio(struct sock *sk, int val)
+{
+	struct dccp_sock *dp = dccp_sk(sk);
+	/*
+	 * XXX I don't really agree with val != 2.  If cwnd is 1, ack ratio
+	 * should be 1... it shouldn't be allowed to become 2.
+	 * -sorbo.
+	 */
+	if (val != 2) {
+		struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk);
+		int max = hctx->ccid2hctx_cwnd / 2;
+
+		/* round up */
+		if (hctx->ccid2hctx_cwnd & 1)
+			max++;
+
+		if (val > max)
+			val = max;
+	}
+
+	ccid2_pr_debug("changing local ack ratio to %d\n", val);
+	WARN_ON(val <= 0);
+	dp->dccps_l_ack_ratio = val;
+}
+
+static void ccid2_change_cwnd(struct sock *sk, int val)
+{
+	struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk);
+
+	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;
+}
+
+static void ccid2_start_rto_timer(struct sock *sk);
+
+static void ccid2_hc_tx_rto_expire(unsigned long data)
+{
+	struct sock *sk = (struct sock *)data;
+	struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk);
+	long s;
+
+	/* XXX I don't think i'm locking correctly
+	 * -sorbo.
+	 */
+	bh_lock_sock(sk);
+	if (sock_owned_by_user(sk)) {
+		sk_reset_timer(sk, &hctx->ccid2hctx_rtotimer,
+			       jiffies + HZ / 5);
+		goto out;
+	}
+
+	ccid2_pr_debug("RTO_EXPIRE\n");
+
+	ccid2_hc_tx_check_sanity(hctx);
+
+	/* back-off timer */
+	hctx->ccid2hctx_rto <<= 1;
+
+	s = hctx->ccid2hctx_rto / HZ;
+	if (s > 60)
+		hctx->ccid2hctx_rto = 60 * HZ;
+
+	ccid2_start_rto_timer(sk);
+
+	/* adjust pipe, cwnd etc */
+	hctx->ccid2hctx_pipe = 0;
+	hctx->ccid2hctx_ssthresh = hctx->ccid2hctx_cwnd >> 1;
+	if (hctx->ccid2hctx_ssthresh < 2)
+		hctx->ccid2hctx_ssthresh = 2;
+	ccid2_change_cwnd(sk, 1);
+
+	/* clear state about stuff we sent */
+	hctx->ccid2hctx_seqt	= hctx->ccid2hctx_seqh;
+	hctx->ccid2hctx_ssacks	= 0;
+	hctx->ccid2hctx_acks	= 0;
+	hctx->ccid2hctx_sent	= 0;
+
+	/* clear ack ratio state. */
+	hctx->ccid2hctx_arsent	 = 0;
+	hctx->ccid2hctx_ackloss  = 0;
+	hctx->ccid2hctx_rpseq	 = 0;
+	hctx->ccid2hctx_rpdupack = -1;
+	ccid2_change_l_ack_ratio(sk, 1);
+	ccid2_hc_tx_check_sanity(hctx);
+out:
+	bh_unlock_sock(sk);
+/*	sock_put(sk); */
+}
+
+static void ccid2_start_rto_timer(struct sock *sk)
+{
+	struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk);
+
+	ccid2_pr_debug("setting RTO timeout=%ld\n", hctx->ccid2hctx_rto);
+
+	BUG_ON(timer_pending(&hctx->ccid2hctx_rtotimer));
+	sk_reset_timer(sk, &hctx->ccid2hctx_rtotimer,
+		       jiffies + hctx->ccid2hctx_rto);
+}
+
+static void ccid2_hc_tx_packet_sent(struct sock *sk, int more, int len)
+{
+	struct dccp_sock *dp = dccp_sk(sk);
+	struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk);
+	u64 seq;
+
+	ccid2_hc_tx_check_sanity(hctx);
+
+	BUG_ON(!hctx->ccid2hctx_sendwait);
+	hctx->ccid2hctx_sendwait = 0;
+	hctx->ccid2hctx_pipe++;
+	BUG_ON(hctx->ccid2hctx_pipe < 0);
+
+	/* There is an issue.  What if another packet is sent between
+	 * packet_send() and packet_sent().  Then the sequence number would be
+	 * wrong.
+	 * -sorbo.
+	 */
+	seq = dp->dccps_gss;
+
+	hctx->ccid2hctx_seqh->ccid2s_seq   = seq;
+	hctx->ccid2hctx_seqh->ccid2s_acked = 0;
+	hctx->ccid2hctx_seqh->ccid2s_sent  = jiffies;
+	hctx->ccid2hctx_seqh = hctx->ccid2hctx_seqh->ccid2s_next;
+
+	ccid2_pr_debug("cwnd=%d pipe=%d\n", hctx->ccid2hctx_cwnd,
+		       hctx->ccid2hctx_pipe);
+
+	if (hctx->ccid2hctx_seqh == hctx->ccid2hctx_seqt) {
+		/* XXX allocate more space */
+		WARN_ON(1);
+	}
+
+	hctx->ccid2hctx_sent++;
+
+	/* Ack Ratio.  Need to maintain a concept of how many windows we sent */
+	hctx->ccid2hctx_arsent++;
+	/* We had an ack loss in this window... */
+	if (hctx->ccid2hctx_ackloss) {
+		if (hctx->ccid2hctx_arsent >= hctx->ccid2hctx_cwnd) {
+			hctx->ccid2hctx_arsent = 0;
+			hctx->ccid2hctx_ackloss = 0;
+		}
+	}
+	/* No acks lost up to now... */
+	else {
+		/* decrease ack ratio if enough packets were sent */
+		if (dp->dccps_l_ack_ratio > 1) {
+			/* XXX don't calculate denominator each time */
+			int denom;
+
+			denom = dp->dccps_l_ack_ratio * dp->dccps_l_ack_ratio -
+				dp->dccps_l_ack_ratio;
+			denom = hctx->ccid2hctx_cwnd * hctx->ccid2hctx_cwnd / denom;
+
+			if (hctx->ccid2hctx_arsent >= denom) {
+				ccid2_change_l_ack_ratio(sk, dp->dccps_l_ack_ratio - 1);
+				hctx->ccid2hctx_arsent = 0;
+			}
+		}
+		/* we can't increase ack ratio further [1] */
+		else {
+			hctx->ccid2hctx_arsent = 0; /* or maybe set it to cwnd*/
+		}
+	}
+
+	/* setup RTO timer */
+	if (!timer_pending(&hctx->ccid2hctx_rtotimer)) {
+		ccid2_start_rto_timer(sk);
+	}
+#ifdef CCID2_DEBUG
+	ccid2_pr_debug("pipe=%d\n", hctx->ccid2hctx_pipe);
+	ccid2_pr_debug("Sent: seq=%llu\n", seq);
+	do {
+		struct ccid2_seq *seqp = hctx->ccid2hctx_seqt;
+
+		while (seqp != hctx->ccid2hctx_seqh) {
+			ccid2_pr_debug("out seq=%llu acked=%d time=%lu\n",
+			       	       seqp->ccid2s_seq, seqp->ccid2s_acked,
+				       seqp->ccid2s_sent);
+			seqp = seqp->ccid2s_next;
+		}
+	} while(0);
+	ccid2_pr_debug("=========\n");
+	ccid2_hc_tx_check_sanity(hctx);
+#endif
+}
+
+/* XXX Lame code duplication!
+ * returns -1 if none was found.
+ * else returns the next offset to use in the function call.
+ */
+static int ccid2_ackvector(struct sock *sk, struct sk_buff *skb, int offset,
+			   unsigned char **vec, unsigned char *veclen)
+{
+        const struct dccp_hdr *dh = dccp_hdr(skb);
+        unsigned char *options = (unsigned char *)dh + dccp_hdr_len(skb);
+        unsigned char *opt_ptr;
+        const unsigned char *opt_end = (unsigned char *)dh +
+                                        (dh->dccph_doff * 4);
+        unsigned char opt, len;
+        unsigned char *value;
+
+	BUG_ON(offset < 0);
+	options += offset;
+	opt_ptr = options;
+	if (opt_ptr >= opt_end)
+		return -1;
+
+	while (opt_ptr != opt_end) {
+                opt   = *opt_ptr++;
+                len   = 0;
+                value = NULL;
+
+                /* Check if this isn't a single byte option */
+                if (opt > DCCPO_MAX_RESERVED) {
+                        if (opt_ptr == opt_end)
+                                goto out_invalid_option;
+
+                        len = *opt_ptr++;
+                        if (len < 3)
+                                goto out_invalid_option;
+                        /*
+                         * Remove the type and len fields, leaving
+                         * just the value size
+                         */
+                        len     -= 2;
+                        value   = opt_ptr;
+                        opt_ptr += len;
+
+                        if (opt_ptr > opt_end)
+                                goto out_invalid_option;
+                }
+
+		switch (opt) {
+		case DCCPO_ACK_VECTOR_0:
+		case DCCPO_ACK_VECTOR_1:
+			*vec	= value;
+			*veclen = len;
+			return offset + (opt_ptr - options);
+			break;
+		}
+	}
+
+	return -1;
+
+out_invalid_option:
+	BUG_ON(1); /* should never happen... options were previously parsed ! */
+	return -1;
+}
+
+static void ccid2_hc_tx_kill_rto_timer(struct ccid2_hc_tx_sock *hctx)
+{
+	if (del_timer(&hctx->ccid2hctx_rtotimer))
+		ccid2_pr_debug("deleted RTO timer\n");
+}
+
+static inline void ccid2_new_ack(struct sock *sk,
+			         struct ccid2_seq *seqp,
+				 unsigned int *maxincr)
+{
+	struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk);
+
+	/* slow start */
+	if (hctx->ccid2hctx_cwnd < hctx->ccid2hctx_ssthresh) {
+		hctx->ccid2hctx_acks = 0;
+
+		/* We can increase cwnd at most maxincr [ack_ratio/2] */
+		if (*maxincr) {
+			/* increase every 2 acks */
+			hctx->ccid2hctx_ssacks++;
+			if (hctx->ccid2hctx_ssacks == 2) {
+				ccid2_change_cwnd(sk, hctx->ccid2hctx_cwnd + 1);
+				hctx->ccid2hctx_ssacks = 0;
+				*maxincr = *maxincr - 1;
+			}
+		}
+		/* increased cwnd enough for this single ack */
+		else {
+			hctx->ccid2hctx_ssacks = 0;
+		}
+	}
+	else {
+		hctx->ccid2hctx_ssacks = 0;
+		hctx->ccid2hctx_acks++;
+
+		if (hctx->ccid2hctx_acks >= hctx->ccid2hctx_cwnd) {
+			ccid2_change_cwnd(sk, hctx->ccid2hctx_cwnd + 1);
+			hctx->ccid2hctx_acks = 0;
+		}
+	}
+
+	/* update RTO */
+	if (hctx->ccid2hctx_srtt == -1 ||
+	    (jiffies - hctx->ccid2hctx_lastrtt) >= hctx->ccid2hctx_srtt) {
+		unsigned long r = jiffies - seqp->ccid2s_sent;
+		int s;
+
+		/* first measurement */
+		if (hctx->ccid2hctx_srtt == -1) {
+			ccid2_pr_debug("R: %lu Time=%lu seq=%llu\n",
+			       	       r, jiffies, seqp->ccid2s_seq);
+			hctx->ccid2hctx_srtt = r;
+			hctx->ccid2hctx_rttvar = r >> 1;
+		}
+		else {
+			/* RTTVAR */
+			long tmp = hctx->ccid2hctx_srtt - r;
+			if (tmp < 0)
+				tmp *= -1;
+
+			tmp >>= 2;
+			hctx->ccid2hctx_rttvar *= 3;
+			hctx->ccid2hctx_rttvar >>= 2;
+			hctx->ccid2hctx_rttvar += tmp;
+
+			/* SRTT */
+			hctx->ccid2hctx_srtt *= 7;
+			hctx->ccid2hctx_srtt >>= 3;
+			tmp = r >> 3;
+			hctx->ccid2hctx_srtt += tmp;
+		}
+		s = hctx->ccid2hctx_rttvar << 2;
+		/* clock granularity is 1 when based on jiffies */
+		if (!s)
+			s = 1;
+		hctx->ccid2hctx_rto = hctx->ccid2hctx_srtt + s;
+
+		/* must be at least a second */
+		s = hctx->ccid2hctx_rto / HZ;
+		/* DCCP doesn't require this [but I like it cuz my code sux] */
+#if 1
+		if (s < 1)
+			hctx->ccid2hctx_rto = HZ;
+#endif
+		/* max 60 seconds */
+		if (s > 60)
+			hctx->ccid2hctx_rto = HZ * 60;
+
+		hctx->ccid2hctx_lastrtt = jiffies;
+
+		ccid2_pr_debug("srtt: %ld rttvar: %ld rto: %ld (HZ=%d) R=%lu\n",
+		       	       hctx->ccid2hctx_srtt, hctx->ccid2hctx_rttvar,
+		       	       hctx->ccid2hctx_rto, HZ, r);
+		hctx->ccid2hctx_sent = 0;
+	}
+
+	/* we got a new ack, so re-start RTO timer */
+	ccid2_hc_tx_kill_rto_timer(hctx);
+	ccid2_start_rto_timer(sk);
+}
+
+static void ccid2_hc_tx_dec_pipe(struct ccid2_hc_tx_sock *hctx)
+{
+	hctx->ccid2hctx_pipe--;
+	BUG_ON(hctx->ccid2hctx_pipe < 0);
+
+	if (hctx->ccid2hctx_pipe == 0)
+		ccid2_hc_tx_kill_rto_timer(hctx);
+}
+
+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 *hctx = ccid2_hc_tx_sk(sk);
+	u64 ackno, seqno;
+	struct ccid2_seq *seqp;
+	unsigned char *vector;
+	unsigned char veclen;
+	int offset = 0;
+	int done = 0;
+	int loss = 0;
+	unsigned int maxincr = 0;
+
+	ccid2_hc_tx_check_sanity(hctx);
+	/* 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 (hctx->ccid2hctx_rpdupack == -1) {
+		hctx->ccid2hctx_rpdupack = 0;
+		hctx->ccid2hctx_rpseq = seqno;
+	}
+	else {
+		/* check if packet is consecutive */
+		if ((hctx->ccid2hctx_rpseq + 1) == seqno) {
+			hctx->ccid2hctx_rpseq++;
+		}
+		/* it's a later packet */
+		else if (after48(seqno, hctx->ccid2hctx_rpseq)) {
+			hctx->ccid2hctx_rpdupack++;
+
+			/* check if we got enough dupacks */
+			if (hctx->ccid2hctx_rpdupack >=
+			    hctx->ccid2hctx_numdupack) {
+
+				hctx->ccid2hctx_rpdupack = -1; /* XXX lame */
+				hctx->ccid2hctx_rpseq = 0;
+
+				ccid2_change_l_ack_ratio(sk, dp->dccps_l_ack_ratio << 1);
+			}
+		}
+	}
+
+	/* check forward path congestion */
+	/* still didn't send out new data packets */
+	if (hctx->ccid2hctx_seqh == hctx->ccid2hctx_seqt)
+		return;
+
+	switch (DCCP_SKB_CB(skb)->dccpd_type) {
+	case DCCP_PKT_ACK:
+	case DCCP_PKT_DATAACK:
+		break;
+
+	default:
+		return;
+	}
+
+	ackno = DCCP_SKB_CB(skb)->dccpd_ack_seq;
+	seqp = hctx->ccid2hctx_seqh->ccid2s_prev;
+
+	/* If in slow-start, cwnd can increase at most Ack Ratio / 2 packets for
+	 * this single ack.  I round up.
+	 * -sorbo.
+	 */
+	maxincr = dp->dccps_l_ack_ratio >> 1;
+	maxincr++;
+
+	/* go through all ack vectors */
+	while ((offset = ccid2_ackvector(sk, skb, offset,
+					 &vector, &veclen)) != -1) {
+		/* go through this ack vector */
+		while (veclen--) {
+			const u8 rl = *vector & DCCP_ACKVEC_LEN_MASK;
+			u64 ackno_end_rl;
+
+			dccp_set_seqno(&ackno_end_rl, ackno - rl);
+			ccid2_pr_debug("ackvec start:%llu end:%llu\n", ackno,
+				       ackno_end_rl);
+			/* 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 == hctx->ccid2hctx_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 = (*vector &
+						  DCCP_ACKVEC_STATE_MASK) >> 6;
+
+				/* new packet received or marked */
+				if (state != DCCP_ACKVEC_STATE_NOT_RECEIVED &&
+				    !seqp->ccid2s_acked) {
+				    	if (state ==
+					    DCCP_ACKVEC_STATE_ECN_MARKED) {
+						loss = 1;
+					}
+					else {
+						ccid2_new_ack(sk, seqp,
+							      &maxincr);
+					}
+
+					seqp->ccid2s_acked = 1;
+					ccid2_pr_debug("Got ack for %llu\n",
+					       	       seqp->ccid2s_seq);
+					ccid2_hc_tx_dec_pipe(hctx);
+				}
+				if (seqp == hctx->ccid2hctx_seqt) {
+					done = 1;
+					break;
+				}
+				seqp = seqp->ccid2s_next;
+			}
+			if (done)
+				break;
+
+
+			dccp_set_seqno(&ackno, ackno_end_rl - 1);
+			vector++;
+		}
+		if (done)
+			break;
+	}
+
+	/* The state about what is acked should be correct now
+	 * Check for NUMDUPACK
+	 */
+	seqp = hctx->ccid2hctx_seqh->ccid2s_prev;
+	done = 0;
+	while (1) {
+		if (seqp->ccid2s_acked) {
+			done++;
+			if (done == hctx->ccid2hctx_numdupack) {
+				break;
+			}
+		}
+		if (seqp == hctx->ccid2hctx_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 == hctx->ccid2hctx_numdupack) {
+		struct ccid2_seq *last_acked = seqp;
+
+		/* check for lost packets */
+		while (1) {
+			if (!seqp->ccid2s_acked) {
+				loss = 1;
+				ccid2_hc_tx_dec_pipe(hctx);
+			}
+			if (seqp == hctx->ccid2hctx_seqt)
+				break;
+			seqp = seqp->ccid2s_prev;
+		}
+
+		hctx->ccid2hctx_seqt = last_acked;
+	}
+
+	/* trim acked packets in tail */
+	while (hctx->ccid2hctx_seqt != hctx->ccid2hctx_seqh) {
+		if (!hctx->ccid2hctx_seqt->ccid2s_acked)
+			break;
+
+		hctx->ccid2hctx_seqt = hctx->ccid2hctx_seqt->ccid2s_next;
+	}
+
+	if (loss) {
+		/* XXX do bit shifts guarantee a 0 as the new bit? */
+		ccid2_change_cwnd(sk, hctx->ccid2hctx_cwnd >> 1);
+		hctx->ccid2hctx_ssthresh = hctx->ccid2hctx_cwnd;
+		if (hctx->ccid2hctx_ssthresh < 2)
+			hctx->ccid2hctx_ssthresh = 2;
+	}
+
+	ccid2_hc_tx_check_sanity(hctx);
+}
+
+static int ccid2_hc_tx_init(struct sock *sk)
+{
+	struct dccp_sock *dp = dccp_sk(sk);
+        struct ccid2_hc_tx_sock *hctx;
+	int seqcount = ccid2_seq_len;
+	int i;
+
+        dp->dccps_hc_tx_ccid_private = kzalloc(sizeof(*hctx), gfp_any());
+        if (dp->dccps_hc_tx_ccid_private == NULL)
+                return -ENOMEM;
+
+        hctx = ccid2_hc_tx_sk(sk);
+
+	/* XXX init variables with proper values */
+	hctx->ccid2hctx_cwnd	  = 1;
+	hctx->ccid2hctx_ssthresh  = 10;
+	hctx->ccid2hctx_numdupack = 3;
+
+	/* XXX init ~ to window size... */
+	hctx->ccid2hctx_seqbuf = kmalloc(sizeof(*hctx->ccid2hctx_seqbuf) *
+					 seqcount, gfp_any());
+	if (hctx->ccid2hctx_seqbuf == NULL) {
+		kfree(dp->dccps_hc_tx_ccid_private);
+		dp->dccps_hc_tx_ccid_private = NULL;
+		return -ENOMEM;
+	}
+	for (i = 0; i < (seqcount - 1); i++) {
+		hctx->ccid2hctx_seqbuf[i].ccid2s_next =
+					&hctx->ccid2hctx_seqbuf[i + 1];
+		hctx->ccid2hctx_seqbuf[i + 1].ccid2s_prev =
+					&hctx->ccid2hctx_seqbuf[i];
+	}
+	hctx->ccid2hctx_seqbuf[seqcount - 1].ccid2s_next =
+					hctx->ccid2hctx_seqbuf;
+	hctx->ccid2hctx_seqbuf->ccid2s_prev =
+					&hctx->ccid2hctx_seqbuf[seqcount - 1];
+
+	hctx->ccid2hctx_seqh	 = hctx->ccid2hctx_seqbuf;
+	hctx->ccid2hctx_seqt	 = hctx->ccid2hctx_seqh;
+	hctx->ccid2hctx_sent	 = 0;
+	hctx->ccid2hctx_rto	 = 3 * HZ;
+	hctx->ccid2hctx_srtt	 = -1;
+	hctx->ccid2hctx_rttvar	 = -1;
+	hctx->ccid2hctx_lastrtt  = 0;
+	hctx->ccid2hctx_rpdupack = -1;
+
+	hctx->ccid2hctx_rtotimer.function = &ccid2_hc_tx_rto_expire;
+	hctx->ccid2hctx_rtotimer.data	  = (unsigned long)sk;
+	init_timer(&hctx->ccid2hctx_rtotimer);
+
+	ccid2_hc_tx_check_sanity(hctx);
+	return 0;
+}
+
+static void ccid2_hc_tx_exit(struct sock *sk)
+{
+	struct dccp_sock *dp = dccp_sk(sk);
+        struct ccid2_hc_tx_sock *hctx = dp->dccps_hc_tx_ccid_private;
+
+	ccid2_hc_tx_kill_rto_timer(hctx);
+
+	kfree(hctx->ccid2hctx_seqbuf);
+
+	kfree(dp->dccps_hc_tx_ccid_private);
+	dp->dccps_hc_tx_ccid_private = NULL;
+}
+
+static void ccid2_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb)
+{
+	const struct dccp_sock *dp = dccp_sk(sk);
+	struct ccid2_hc_rx_sock *hcrx = ccid2_hc_rx_sk(sk);
+
+	switch (DCCP_SKB_CB(skb)->dccpd_type) {
+	case DCCP_PKT_DATA:
+	case DCCP_PKT_DATAACK:
+		hcrx->ccid2hcrx_data++;
+		if (hcrx->ccid2hcrx_data >= dp->dccps_r_ack_ratio) {
+			dccp_send_ack(sk);
+			hcrx->ccid2hcrx_data = 0;
+		}
+		break;
+	}
+}
+
+static int ccid2_hc_rx_init(struct sock *sk)
+{
+	struct dccp_sock *dp = dccp_sk(sk);
+        dp->dccps_hc_rx_ccid_private = kzalloc(sizeof(struct ccid2_hc_rx_sock),
+					       gfp_any());
+        return dp->dccps_hc_rx_ccid_private == NULL ? -ENOMEM : 0;
+}
+
+static void ccid2_hc_rx_exit(struct sock *sk)
+{
+	struct dccp_sock *dp = dccp_sk(sk);
+
+	kfree(dp->dccps_hc_rx_ccid_private);
+	dp->dccps_hc_rx_ccid_private = NULL;
+}
+
+static struct ccid ccid2 = {
+	.ccid_id		= 2,
+	.ccid_name		= "ccid2",
+	.ccid_owner		= THIS_MODULE,
+	.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_packet_recv	= ccid2_hc_tx_packet_recv,
+	.ccid_hc_rx_init	= ccid2_hc_rx_init,
+	.ccid_hc_rx_exit	= ccid2_hc_rx_exit,
+	.ccid_hc_rx_packet_recv	= ccid2_hc_rx_packet_recv,
+};
+
+module_param(ccid2_debug, int, 0444);
+MODULE_PARM_DESC(ccid2_debug, "Enable debug messages");
+
+static __init int ccid2_module_init(void)
+{
+	return ccid_register(&ccid2);
+}
+module_init(ccid2_module_init);
+
+static __exit void ccid2_module_exit(void)
+{
+	ccid_unregister(&ccid2);
+}
+module_exit(ccid2_module_exit);
+
+MODULE_AUTHOR("Andrea Bittau <a.bittau@cs.ucl.ac.uk>");
+MODULE_DESCRIPTION("DCCP TCP CCID2 CCID");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("net-dccp-ccid-2");
-- 
cgit v1.2.3-70-g09d2


From 77ff72d528d5b9d30a47f42f364ba34d931f9da3 Mon Sep 17 00:00:00 2001
From: Andrea Bittau <a.bittau@cs.ucl.ac.uk>
Date: Mon, 20 Mar 2006 17:57:52 -0800
Subject: [DCCP] CCID2: Drop sock reference count on timer expiration and
 reset.

There was a hybrid use of standard timers and sk_timers.  This caused
the reference count of the sock to be incorrect when resetting the RTO
timer.  The sock reference count should now be correct, enabling its
destruction, and allowing the DCCP module to be unloaded.

Signed-off-by: Andrea Bittau <a.bittau@cs.ucl.ac.uk>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
---
 net/dccp/ccids/ccid2.c | 26 +++++++++++++++-----------
 1 file changed, 15 insertions(+), 11 deletions(-)

(limited to 'net/dccp/ccids/ccid2.c')

diff --git a/net/dccp/ccids/ccid2.c b/net/dccp/ccids/ccid2.c
index 4a7b8751256..3328d23c4be 100644
--- a/net/dccp/ccids/ccid2.c
+++ b/net/dccp/ccids/ccid2.c
@@ -234,7 +234,7 @@ static void ccid2_hc_tx_rto_expire(unsigned long data)
 	ccid2_hc_tx_check_sanity(hctx);
 out:
 	bh_unlock_sock(sk);
-/*	sock_put(sk); */
+	sock_put(sk);
 }
 
 static void ccid2_start_rto_timer(struct sock *sk)
@@ -399,10 +399,12 @@ out_invalid_option:
 	return -1;
 }
 
-static void ccid2_hc_tx_kill_rto_timer(struct ccid2_hc_tx_sock *hctx)
+static void ccid2_hc_tx_kill_rto_timer(struct sock *sk)
 {
-	if (del_timer(&hctx->ccid2hctx_rtotimer))
-		ccid2_pr_debug("deleted RTO timer\n");
+	struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk);
+
+	sk_stop_timer(sk, &hctx->ccid2hctx_rtotimer);
+	ccid2_pr_debug("deleted RTO timer\n");
 }
 
 static inline void ccid2_new_ack(struct sock *sk,
@@ -496,17 +498,19 @@ static inline void ccid2_new_ack(struct sock *sk,
 	}
 
 	/* we got a new ack, so re-start RTO timer */
-	ccid2_hc_tx_kill_rto_timer(hctx);
+	ccid2_hc_tx_kill_rto_timer(sk);
 	ccid2_start_rto_timer(sk);
 }
 
-static void ccid2_hc_tx_dec_pipe(struct ccid2_hc_tx_sock *hctx)
+static void ccid2_hc_tx_dec_pipe(struct sock *sk)
 {
+	struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk);
+
 	hctx->ccid2hctx_pipe--;
 	BUG_ON(hctx->ccid2hctx_pipe < 0);
 
 	if (hctx->ccid2hctx_pipe == 0)
-		ccid2_hc_tx_kill_rto_timer(hctx);
+		ccid2_hc_tx_kill_rto_timer(sk);
 }
 
 static void ccid2_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb)
@@ -627,7 +631,7 @@ static void ccid2_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb)
 					seqp->ccid2s_acked = 1;
 					ccid2_pr_debug("Got ack for %llu\n",
 					       	       seqp->ccid2s_seq);
-					ccid2_hc_tx_dec_pipe(hctx);
+					ccid2_hc_tx_dec_pipe(sk);
 				}
 				if (seqp == hctx->ccid2hctx_seqt) {
 					done = 1;
@@ -674,7 +678,7 @@ static void ccid2_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb)
 		while (1) {
 			if (!seqp->ccid2s_acked) {
 				loss = 1;
-				ccid2_hc_tx_dec_pipe(hctx);
+				ccid2_hc_tx_dec_pipe(sk);
 			}
 			if (seqp == hctx->ccid2hctx_seqt)
 				break;
@@ -760,9 +764,9 @@ static int ccid2_hc_tx_init(struct sock *sk)
 static void ccid2_hc_tx_exit(struct sock *sk)
 {
 	struct dccp_sock *dp = dccp_sk(sk);
-        struct ccid2_hc_tx_sock *hctx = dp->dccps_hc_tx_ccid_private;
+        struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk);
 
-	ccid2_hc_tx_kill_rto_timer(hctx);
+	ccid2_hc_tx_kill_rto_timer(sk);
 
 	kfree(hctx->ccid2hctx_seqbuf);
 
-- 
cgit v1.2.3-70-g09d2


From 91f0ebf7b6d5cb2b6e818d48587566144821babe Mon Sep 17 00:00:00 2001
From: Arnaldo Carvalho de Melo <acme@mandriva.com>
Date: Mon, 20 Mar 2006 19:21:44 -0800
Subject: [DCCP] CCID: Improve CCID infrastructure

1. No need for ->ccid_init nor ->ccid_exit, this is what module_{init,exit}
   does and anynways neither ccid2 nor ccid3 were using it.

2. Rename struct ccid to struct ccid_operations and introduce struct ccid
   with a pointer to ccid_operations and rigth after it the rx or tx
   private state.

3. Remove the pointer to the state of the half connections from struct
   dccp_sock, now its derived thru ccid_priv() from the ccid pointer.

Now we also can implement the setsockopt for changing the CCID easily as
no ccid init routines can affect struct dccp_sock in any way that prevents
other CCIDs from working if a CCID switch operation is asked by apps.

Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 include/linux/dccp.h   |   2 -
 net/dccp/ccid.c        | 188 ++++++++++++++++++++++++++++++++++++++++---------
 net/dccp/ccid.h        | 115 +++++++++++++-----------------
 net/dccp/ccids/ccid2.c |  55 +++------------
 net/dccp/ccids/ccid2.h |  16 +++++
 net/dccp/ccids/ccid3.c |  34 ++-------
 net/dccp/ccids/ccid3.h |   5 +-
 net/dccp/input.c       |   8 ---
 net/dccp/ipv4.c        |  24 +++----
 net/dccp/minisocks.c   |  25 +++----
 10 files changed, 260 insertions(+), 212 deletions(-)

(limited to 'net/dccp/ccids/ccid2.c')

diff --git a/include/linux/dccp.h b/include/linux/dccp.h
index a70d1a27e7f..bdd756cc60b 100644
--- a/include/linux/dccp.h
+++ b/include/linux/dccp.h
@@ -478,8 +478,6 @@ struct dccp_sock {
 	__u32				dccps_mss_cache;
 	struct dccp_options		dccps_options;
 	struct dccp_ackvec		*dccps_hc_rx_ackvec;
-	void				*dccps_hc_rx_ccid_private;
-	void				*dccps_hc_tx_ccid_private;
 	struct ccid			*dccps_hc_rx_ccid;
 	struct ccid			*dccps_hc_tx_ccid;
 	struct dccp_options_received	dccps_options_received;
diff --git a/net/dccp/ccid.c b/net/dccp/ccid.c
index 06b191a5740..ff05e59043c 100644
--- a/net/dccp/ccid.c
+++ b/net/dccp/ccid.c
@@ -13,7 +13,7 @@
 
 #include "ccid.h"
 
-static struct ccid *ccids[CCID_MAX];
+static struct ccid_operations *ccids[CCID_MAX];
 #if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT)
 static atomic_t ccids_lockct = ATOMIC_INIT(0);
 static DEFINE_SPINLOCK(ccids_lock);
@@ -55,82 +55,202 @@ static inline void ccids_read_unlock(void)
 #define ccids_read_unlock() do { } while(0)
 #endif
 
-int ccid_register(struct ccid *ccid)
+static kmem_cache_t *ccid_kmem_cache_create(int obj_size, const char *fmt,...)
 {
-	int err;
+	kmem_cache_t *slab;
+	char slab_name_fmt[32], *slab_name;
+	va_list args;
+
+	va_start(args, fmt);
+	vsnprintf(slab_name_fmt, sizeof(slab_name_fmt), fmt, args);
+	va_end(args);
+
+	slab_name = kstrdup(slab_name_fmt, GFP_KERNEL);
+	if (slab_name == NULL)
+		return NULL;
+	slab = kmem_cache_create(slab_name, sizeof(struct ccid) + obj_size, 0,
+				 SLAB_HWCACHE_ALIGN, NULL, NULL);
+	if (slab == NULL)
+		kfree(slab_name);
+	return slab;
+}
+
+static void ccid_kmem_cache_destroy(kmem_cache_t *slab)
+{
+	if (slab != NULL) {
+		const char *name = kmem_cache_name(slab);
+
+		kmem_cache_destroy(slab);
+		kfree(name);
+	}
+}
+
+int ccid_register(struct ccid_operations *ccid_ops)
+{
+	int err = -ENOBUFS;
+
+	ccid_ops->ccid_hc_rx_slab =
+			ccid_kmem_cache_create(ccid_ops->ccid_hc_rx_obj_size,
+					       "%s_hc_rx_sock",
+					       ccid_ops->ccid_name);
+	if (ccid_ops->ccid_hc_rx_slab == NULL)
+		goto out;
+
+	ccid_ops->ccid_hc_tx_slab =
+			ccid_kmem_cache_create(ccid_ops->ccid_hc_tx_obj_size,
+					       "%s_hc_tx_sock",
+					       ccid_ops->ccid_name);
+	if (ccid_ops->ccid_hc_tx_slab == NULL)
+		goto out_free_rx_slab;
 
 	ccids_write_lock();
 	err = -EEXIST;
-	if (ccids[ccid->ccid_id] == NULL) {
-		ccids[ccid->ccid_id] = ccid;
+	if (ccids[ccid_ops->ccid_id] == NULL) {
+		ccids[ccid_ops->ccid_id] = ccid_ops;
 		err = 0;
 	}
 	ccids_write_unlock();
-	if (err == 0)
-		pr_info("CCID: Registered CCID %d (%s)\n",
-			ccid->ccid_id, ccid->ccid_name);
+	if (err != 0)
+		goto out_free_tx_slab;
+
+	pr_info("CCID: Registered CCID %d (%s)\n",
+		ccid_ops->ccid_id, ccid_ops->ccid_name);
+out:
 	return err;
+out_free_tx_slab:
+	ccid_kmem_cache_destroy(ccid_ops->ccid_hc_tx_slab);
+	ccid_ops->ccid_hc_tx_slab = NULL;
+	goto out;
+out_free_rx_slab:
+	ccid_kmem_cache_destroy(ccid_ops->ccid_hc_rx_slab);
+	ccid_ops->ccid_hc_rx_slab = NULL;
+	goto out;
 }
 
 EXPORT_SYMBOL_GPL(ccid_register);
 
-int ccid_unregister(struct ccid *ccid)
+int ccid_unregister(struct ccid_operations *ccid_ops)
 {
 	ccids_write_lock();
-	ccids[ccid->ccid_id] = NULL;
+	ccids[ccid_ops->ccid_id] = NULL;
 	ccids_write_unlock();
+
+	ccid_kmem_cache_destroy(ccid_ops->ccid_hc_tx_slab);
+	ccid_ops->ccid_hc_tx_slab = NULL;
+	ccid_kmem_cache_destroy(ccid_ops->ccid_hc_rx_slab);
+	ccid_ops->ccid_hc_rx_slab = NULL;
+
 	pr_info("CCID: Unregistered CCID %d (%s)\n",
-		ccid->ccid_id, ccid->ccid_name);
+		ccid_ops->ccid_id, ccid_ops->ccid_name);
 	return 0;
 }
 
 EXPORT_SYMBOL_GPL(ccid_unregister);
 
-struct ccid *ccid_init(unsigned char id, struct sock *sk)
+struct ccid *ccid_new(unsigned char id, struct sock *sk, int rx, gfp_t gfp)
 {
-	struct ccid *ccid;
+	struct ccid_operations *ccid_ops;
+	struct ccid *ccid = NULL;
 
+	ccids_read_lock();
 #ifdef CONFIG_KMOD
-	if (ccids[id] == NULL)
+	if (ccids[id] == NULL) {
+		/* We only try to load if in process context */
+		ccids_read_unlock();
+		if (gfp & GFP_ATOMIC)
+			goto out;
 		request_module("net-dccp-ccid-%d", id);
+		ccids_read_lock();
+	}
 #endif
-	ccids_read_lock();
+	ccid_ops = ccids[id];
+	if (ccid_ops == NULL)
+		goto out_unlock;
 
-	ccid = ccids[id];
-	if (ccid == NULL)
-		goto out;
+	if (!try_module_get(ccid_ops->ccid_owner))
+		goto out_unlock;
 
-	if (!try_module_get(ccid->ccid_owner))
-		goto out_err;
+	ccids_read_unlock();
 
-	if (ccid->ccid_init != NULL && ccid->ccid_init(sk) != 0)
+	ccid = kmem_cache_alloc(rx ? ccid_ops->ccid_hc_rx_slab :
+				     ccid_ops->ccid_hc_tx_slab, gfp);
+	if (ccid == NULL)
 		goto out_module_put;
+	ccid->ccid_ops = ccid_ops;
+	if (rx) {
+		memset(ccid + 1, 0, ccid_ops->ccid_hc_rx_obj_size);
+		if (ccid->ccid_ops->ccid_hc_rx_init != NULL &&
+		    ccid->ccid_ops->ccid_hc_rx_init(ccid, sk) != 0)
+			goto out_free_ccid;
+	} else {
+		memset(ccid + 1, 0, ccid_ops->ccid_hc_tx_obj_size);
+		if (ccid->ccid_ops->ccid_hc_tx_init != NULL &&
+		    ccid->ccid_ops->ccid_hc_tx_init(ccid, sk) != 0)
+			goto out_free_ccid;
+	}
 out:
-	ccids_read_unlock();
 	return ccid;
-out_module_put:
-	module_put(ccid->ccid_owner);
-out_err:
+out_unlock:
+	ccids_read_unlock();
+	goto out;
+out_free_ccid:
+	kmem_cache_free(rx ? ccid_ops->ccid_hc_rx_slab :
+			ccid_ops->ccid_hc_tx_slab, ccid);
 	ccid = NULL;
+out_module_put:
+	module_put(ccid_ops->ccid_owner);
 	goto out;
 }
 
-EXPORT_SYMBOL_GPL(ccid_init);
+EXPORT_SYMBOL_GPL(ccid_new);
 
-void ccid_exit(struct ccid *ccid, struct sock *sk)
+struct ccid *ccid_hc_rx_new(unsigned char id, struct sock *sk, gfp_t gfp)
 {
+	return ccid_new(id, sk, 1, gfp);
+}
+
+EXPORT_SYMBOL_GPL(ccid_hc_rx_new);
+
+struct ccid *ccid_hc_tx_new(unsigned char id,struct sock *sk,  gfp_t gfp)
+{
+	return ccid_new(id, sk, 0, gfp);
+}
+
+EXPORT_SYMBOL_GPL(ccid_hc_tx_new);
+
+static void ccid_delete(struct ccid *ccid, struct sock *sk, int rx)
+{
+	struct ccid_operations *ccid_ops;
+
 	if (ccid == NULL)
 		return;
 
+	ccid_ops = ccid->ccid_ops;
+	if (rx) {
+		if (ccid_ops->ccid_hc_rx_exit != NULL)
+			ccid_ops->ccid_hc_rx_exit(sk);
+		kmem_cache_free(ccid_ops->ccid_hc_rx_slab,  ccid);
+	} else {
+		if (ccid_ops->ccid_hc_tx_exit != NULL)
+			ccid_ops->ccid_hc_tx_exit(sk);
+		kmem_cache_free(ccid_ops->ccid_hc_tx_slab,  ccid);
+	}
 	ccids_read_lock();
+	if (ccids[ccid_ops->ccid_id] != NULL)
+		module_put(ccid_ops->ccid_owner);
+	ccids_read_unlock();
+}
 
-	if (ccids[ccid->ccid_id] != NULL) {
-		if (ccid->ccid_exit != NULL)
-			ccid->ccid_exit(sk);
-		module_put(ccid->ccid_owner);
-	}
+void ccid_hc_rx_delete(struct ccid *ccid, struct sock *sk)
+{
+	ccid_delete(ccid, sk, 1);
+}
 
-	ccids_read_unlock();
+EXPORT_SYMBOL_GPL(ccid_hc_rx_delete);
+
+void ccid_hc_tx_delete(struct ccid *ccid, struct sock *sk)
+{
+	ccid_delete(ccid, sk, 0);
 }
 
-EXPORT_SYMBOL_GPL(ccid_exit);
+EXPORT_SYMBOL_GPL(ccid_hc_tx_delete);
diff --git a/net/dccp/ccid.h b/net/dccp/ccid.h
index de681c6ad08..3dec50d4973 100644
--- a/net/dccp/ccid.h
+++ b/net/dccp/ccid.h
@@ -23,14 +23,16 @@
 
 struct tcp_info;
 
-struct ccid {
+struct ccid_operations {
 	unsigned char	ccid_id;
 	const char	*ccid_name;
 	struct module	*ccid_owner;
-	int		(*ccid_init)(struct sock *sk);
-	void		(*ccid_exit)(struct sock *sk);
-	int		(*ccid_hc_rx_init)(struct sock *sk);
-	int		(*ccid_hc_tx_init)(struct sock *sk);
+	kmem_cache_t	*ccid_hc_rx_slab;
+	__u32		ccid_hc_rx_obj_size;
+	kmem_cache_t	*ccid_hc_tx_slab;
+	__u32		ccid_hc_tx_obj_size;
+	int		(*ccid_hc_rx_init)(struct ccid *ccid, struct sock *sk);
+	int		(*ccid_hc_tx_init)(struct ccid *ccid, struct sock *sk);
 	void		(*ccid_hc_rx_exit)(struct sock *sk);
 	void		(*ccid_hc_tx_exit)(struct sock *sk);
 	void		(*ccid_hc_rx_packet_recv)(struct sock *sk,
@@ -67,75 +69,58 @@ struct ccid {
 						 int __user *optlen);
 };
 
-extern int	   ccid_register(struct ccid *ccid);
-extern int	   ccid_unregister(struct ccid *ccid);
+extern int ccid_register(struct ccid_operations *ccid_ops);
+extern int ccid_unregister(struct ccid_operations *ccid_ops);
 
-extern struct ccid *ccid_init(unsigned char id, struct sock *sk);
-extern void	   ccid_exit(struct ccid *ccid, struct sock *sk);
+struct ccid {
+	struct ccid_operations *ccid_ops;
+	char		       ccid_priv[0];
+};
 
-static inline void __ccid_get(struct ccid *ccid)
+static inline void *ccid_priv(const struct ccid *ccid)
 {
-	__module_get(ccid->ccid_owner);
+	return (void *)ccid->ccid_priv;
 }
 
+extern struct ccid *ccid_new(unsigned char id, struct sock *sk, int rx,
+			     gfp_t gfp);
+
+extern struct ccid *ccid_hc_rx_new(unsigned char id, struct sock *sk,
+				   gfp_t gfp);
+extern struct ccid *ccid_hc_tx_new(unsigned char id, struct sock *sk,
+				   gfp_t gfp);
+
+extern void ccid_hc_rx_delete(struct ccid *ccid, struct sock *sk);
+extern void ccid_hc_tx_delete(struct ccid *ccid, struct sock *sk);
+
 static inline int ccid_hc_tx_send_packet(struct ccid *ccid, struct sock *sk,
 					 struct sk_buff *skb, int len)
 {
 	int rc = 0;
-	if (ccid->ccid_hc_tx_send_packet != NULL)
-		rc = ccid->ccid_hc_tx_send_packet(sk, skb, len);
+	if (ccid->ccid_ops->ccid_hc_tx_send_packet != NULL)
+		rc = ccid->ccid_ops->ccid_hc_tx_send_packet(sk, skb, len);
 	return rc;
 }
 
 static inline void ccid_hc_tx_packet_sent(struct ccid *ccid, struct sock *sk,
 					  int more, int len)
 {
-	if (ccid->ccid_hc_tx_packet_sent != NULL)
-		ccid->ccid_hc_tx_packet_sent(sk, more, len);
-}
-
-static inline int ccid_hc_rx_init(struct ccid *ccid, struct sock *sk)
-{
-	int rc = 0;
-	if (ccid->ccid_hc_rx_init != NULL)
-		rc = ccid->ccid_hc_rx_init(sk);
-	return rc;
-}
-
-static inline int ccid_hc_tx_init(struct ccid *ccid, struct sock *sk)
-{
-	int rc = 0;
-	if (ccid->ccid_hc_tx_init != NULL)
-		rc = ccid->ccid_hc_tx_init(sk);
-	return rc;
-}
-
-static inline void ccid_hc_rx_exit(struct ccid *ccid, struct sock *sk)
-{
-	if (ccid != NULL && ccid->ccid_hc_rx_exit != NULL &&
-	    dccp_sk(sk)->dccps_hc_rx_ccid_private != NULL)
-		ccid->ccid_hc_rx_exit(sk);
-}
-
-static inline void ccid_hc_tx_exit(struct ccid *ccid, struct sock *sk)
-{
-	if (ccid != NULL && ccid->ccid_hc_tx_exit != NULL &&
-	    dccp_sk(sk)->dccps_hc_tx_ccid_private != NULL)
-		ccid->ccid_hc_tx_exit(sk);
+	if (ccid->ccid_ops->ccid_hc_tx_packet_sent != NULL)
+		ccid->ccid_ops->ccid_hc_tx_packet_sent(sk, more, len);
 }
 
 static inline void ccid_hc_rx_packet_recv(struct ccid *ccid, struct sock *sk,
 					  struct sk_buff *skb)
 {
-	if (ccid->ccid_hc_rx_packet_recv != NULL)
-		ccid->ccid_hc_rx_packet_recv(sk, skb);
+	if (ccid->ccid_ops->ccid_hc_rx_packet_recv != NULL)
+		ccid->ccid_ops->ccid_hc_rx_packet_recv(sk, skb);
 }
 
 static inline void ccid_hc_tx_packet_recv(struct ccid *ccid, struct sock *sk,
 					  struct sk_buff *skb)
 {
-	if (ccid->ccid_hc_tx_packet_recv != NULL)
-		ccid->ccid_hc_tx_packet_recv(sk, skb);
+	if (ccid->ccid_ops->ccid_hc_tx_packet_recv != NULL)
+		ccid->ccid_ops->ccid_hc_tx_packet_recv(sk, skb);
 }
 
 static inline int ccid_hc_tx_parse_options(struct ccid *ccid, struct sock *sk,
@@ -144,8 +129,8 @@ static inline int ccid_hc_tx_parse_options(struct ccid *ccid, struct sock *sk,
 					   unsigned char* value)
 {
 	int rc = 0;
-	if (ccid->ccid_hc_tx_parse_options != NULL)
-		rc = ccid->ccid_hc_tx_parse_options(sk, option, len, idx,
+	if (ccid->ccid_ops->ccid_hc_tx_parse_options != NULL)
+		rc = ccid->ccid_ops->ccid_hc_tx_parse_options(sk, option, len, idx,
 						    value);
 	return rc;
 }
@@ -156,37 +141,37 @@ static inline int ccid_hc_rx_parse_options(struct ccid *ccid, struct sock *sk,
 					   unsigned char* value)
 {
 	int rc = 0;
-	if (ccid->ccid_hc_rx_parse_options != NULL)
-		rc = ccid->ccid_hc_rx_parse_options(sk, option, len, idx, value);
+	if (ccid->ccid_ops->ccid_hc_rx_parse_options != NULL)
+		rc = ccid->ccid_ops->ccid_hc_rx_parse_options(sk, option, len, idx, value);
 	return rc;
 }
 
 static inline void ccid_hc_tx_insert_options(struct ccid *ccid, struct sock *sk,
 					     struct sk_buff *skb)
 {
-	if (ccid->ccid_hc_tx_insert_options != NULL)
-		ccid->ccid_hc_tx_insert_options(sk, skb);
+	if (ccid->ccid_ops->ccid_hc_tx_insert_options != NULL)
+		ccid->ccid_ops->ccid_hc_tx_insert_options(sk, skb);
 }
 
 static inline void ccid_hc_rx_insert_options(struct ccid *ccid, struct sock *sk,
 					     struct sk_buff *skb)
 {
-	if (ccid->ccid_hc_rx_insert_options != NULL)
-		ccid->ccid_hc_rx_insert_options(sk, skb);
+	if (ccid->ccid_ops->ccid_hc_rx_insert_options != NULL)
+		ccid->ccid_ops->ccid_hc_rx_insert_options(sk, skb);
 }
 
 static inline void ccid_hc_rx_get_info(struct ccid *ccid, struct sock *sk,
 				       struct tcp_info *info)
 {
-	if (ccid->ccid_hc_rx_get_info != NULL)
-		ccid->ccid_hc_rx_get_info(sk, info);
+	if (ccid->ccid_ops->ccid_hc_rx_get_info != NULL)
+		ccid->ccid_ops->ccid_hc_rx_get_info(sk, info);
 }
 
 static inline void ccid_hc_tx_get_info(struct ccid *ccid, struct sock *sk,
 				       struct tcp_info *info)
 {
-	if (ccid->ccid_hc_tx_get_info != NULL)
-		ccid->ccid_hc_tx_get_info(sk, info);
+	if (ccid->ccid_ops->ccid_hc_tx_get_info != NULL)
+		ccid->ccid_ops->ccid_hc_tx_get_info(sk, info);
 }
 
 static inline int ccid_hc_rx_getsockopt(struct ccid *ccid, struct sock *sk,
@@ -194,8 +179,8 @@ static inline int ccid_hc_rx_getsockopt(struct ccid *ccid, struct sock *sk,
 					u32 __user *optval, int __user *optlen)
 {
 	int rc = -ENOPROTOOPT;
-	if (ccid->ccid_hc_rx_getsockopt != NULL)
-		rc = ccid->ccid_hc_rx_getsockopt(sk, optname, len,
+	if (ccid->ccid_ops->ccid_hc_rx_getsockopt != NULL)
+		rc = ccid->ccid_ops->ccid_hc_rx_getsockopt(sk, optname, len,
 						 optval, optlen);
 	return rc;
 }
@@ -205,8 +190,8 @@ static inline int ccid_hc_tx_getsockopt(struct ccid *ccid, struct sock *sk,
 					u32 __user *optval, int __user *optlen)
 {
 	int rc = -ENOPROTOOPT;
-	if (ccid->ccid_hc_tx_getsockopt != NULL)
-		rc = ccid->ccid_hc_tx_getsockopt(sk, optname, len,
+	if (ccid->ccid_ops->ccid_hc_tx_getsockopt != NULL)
+		rc = ccid->ccid_ops->ccid_hc_tx_getsockopt(sk, optname, len,
 						 optval, optlen);
 	return rc;
 }
diff --git a/net/dccp/ccids/ccid2.c b/net/dccp/ccids/ccid2.c
index 3328d23c4be..b40c4569a82 100644
--- a/net/dccp/ccids/ccid2.c
+++ b/net/dccp/ccids/ccid2.c
@@ -52,16 +52,6 @@ static int ccid2_debug;
 
 static const int ccid2_seq_len = 128;
 
-static inline struct ccid2_hc_tx_sock *ccid2_hc_tx_sk(const struct sock *sk)
-{
-	return dccp_sk(sk)->dccps_hc_tx_ccid_private;
-}
-
-static inline struct ccid2_hc_rx_sock *ccid2_hc_rx_sk(const struct sock *sk)
-{
-	return dccp_sk(sk)->dccps_hc_rx_ccid_private;
-}
-
 #ifdef CCID2_DEBUG
 static void ccid2_hc_tx_check_sanity(const struct ccid2_hc_tx_sock *hctx)
 {
@@ -707,19 +697,12 @@ static void ccid2_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb)
 	ccid2_hc_tx_check_sanity(hctx);
 }
 
-static int ccid2_hc_tx_init(struct sock *sk)
+static int ccid2_hc_tx_init(struct ccid *ccid, struct sock *sk)
 {
-	struct dccp_sock *dp = dccp_sk(sk);
-        struct ccid2_hc_tx_sock *hctx;
+        struct ccid2_hc_tx_sock *hctx = ccid_priv(ccid);
 	int seqcount = ccid2_seq_len;
 	int i;
 
-        dp->dccps_hc_tx_ccid_private = kzalloc(sizeof(*hctx), gfp_any());
-        if (dp->dccps_hc_tx_ccid_private == NULL)
-                return -ENOMEM;
-
-        hctx = ccid2_hc_tx_sk(sk);
-
 	/* XXX init variables with proper values */
 	hctx->ccid2hctx_cwnd	  = 1;
 	hctx->ccid2hctx_ssthresh  = 10;
@@ -728,11 +711,9 @@ static int ccid2_hc_tx_init(struct sock *sk)
 	/* XXX init ~ to window size... */
 	hctx->ccid2hctx_seqbuf = kmalloc(sizeof(*hctx->ccid2hctx_seqbuf) *
 					 seqcount, gfp_any());
-	if (hctx->ccid2hctx_seqbuf == NULL) {
-		kfree(dp->dccps_hc_tx_ccid_private);
-		dp->dccps_hc_tx_ccid_private = NULL;
+	if (hctx->ccid2hctx_seqbuf == NULL)
 		return -ENOMEM;
-	}
+
 	for (i = 0; i < (seqcount - 1); i++) {
 		hctx->ccid2hctx_seqbuf[i].ccid2s_next =
 					&hctx->ccid2hctx_seqbuf[i + 1];
@@ -763,15 +744,11 @@ static int ccid2_hc_tx_init(struct sock *sk)
 
 static void ccid2_hc_tx_exit(struct sock *sk)
 {
-	struct dccp_sock *dp = dccp_sk(sk);
         struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk);
 
 	ccid2_hc_tx_kill_rto_timer(sk);
-
 	kfree(hctx->ccid2hctx_seqbuf);
-
-	kfree(dp->dccps_hc_tx_ccid_private);
-	dp->dccps_hc_tx_ccid_private = NULL;
+	hctx->ccid2hctx_seqbuf = NULL;
 }
 
 static void ccid2_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb)
@@ -791,33 +768,17 @@ static void ccid2_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb)
 	}
 }
 
-static int ccid2_hc_rx_init(struct sock *sk)
-{
-	struct dccp_sock *dp = dccp_sk(sk);
-        dp->dccps_hc_rx_ccid_private = kzalloc(sizeof(struct ccid2_hc_rx_sock),
-					       gfp_any());
-        return dp->dccps_hc_rx_ccid_private == NULL ? -ENOMEM : 0;
-}
-
-static void ccid2_hc_rx_exit(struct sock *sk)
-{
-	struct dccp_sock *dp = dccp_sk(sk);
-
-	kfree(dp->dccps_hc_rx_ccid_private);
-	dp->dccps_hc_rx_ccid_private = NULL;
-}
-
-static struct ccid ccid2 = {
+static struct ccid_operations ccid2 = {
 	.ccid_id		= 2,
 	.ccid_name		= "ccid2",
 	.ccid_owner		= THIS_MODULE,
+	.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_packet_recv	= ccid2_hc_tx_packet_recv,
-	.ccid_hc_rx_init	= ccid2_hc_rx_init,
-	.ccid_hc_rx_exit	= ccid2_hc_rx_exit,
+	.ccid_hc_rx_obj_size	= sizeof(struct ccid2_hc_rx_sock),
 	.ccid_hc_rx_packet_recv	= ccid2_hc_rx_packet_recv,
 };
 
diff --git a/net/dccp/ccids/ccid2.h b/net/dccp/ccids/ccid2.h
index 0b08c90955a..451a87464fa 100644
--- a/net/dccp/ccids/ccid2.h
+++ b/net/dccp/ccids/ccid2.h
@@ -20,6 +20,13 @@
 #ifndef _DCCP_CCID2_H_
 #define _DCCP_CCID2_H_
 
+#include <linux/dccp.h>
+#include <linux/timer.h>
+#include <linux/types.h>
+#include "../ccid.h"
+
+struct sock;
+
 struct ccid2_seq {
 	u64			ccid2s_seq;
 	unsigned long		ccid2s_sent;
@@ -66,4 +73,13 @@ struct ccid2_hc_rx_sock {
 	int	ccid2hcrx_data;
 };
 
+static inline struct ccid2_hc_tx_sock *ccid2_hc_tx_sk(const struct sock *sk)
+{
+	return ccid_priv(dccp_sk(sk)->dccps_hc_tx_ccid);
+}
+
+static inline struct ccid2_hc_rx_sock *ccid2_hc_rx_sk(const struct sock *sk)
+{
+	return ccid_priv(dccp_sk(sk)->dccps_hc_rx_ccid);
+}
 #endif /* _DCCP_CCID2_H_ */
diff --git a/net/dccp/ccids/ccid3.c b/net/dccp/ccids/ccid3.c
index f9e16db09be..0587f52e4af 100644
--- a/net/dccp/ccids/ccid3.c
+++ b/net/dccp/ccids/ccid3.c
@@ -647,17 +647,10 @@ static int ccid3_hc_tx_parse_options(struct sock *sk, unsigned char option,
 	return rc;
 }
 
-static int ccid3_hc_tx_init(struct sock *sk)
+static int ccid3_hc_tx_init(struct ccid *ccid, 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));
+	struct ccid3_hc_tx_sock *hctx = ccid_priv(ccid);
 
 	if (dp->dccps_packet_size >= TFRC_MIN_PACKET_SIZE &&
 	    dp->dccps_packet_size <= TFRC_MAX_PACKET_SIZE)
@@ -680,7 +673,6 @@ static int ccid3_hc_tx_init(struct sock *sk)
 
 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);
@@ -690,9 +682,6 @@ static void ccid3_hc_tx_exit(struct sock *sk)
 
 	/* 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;
 }
 
 /*
@@ -1039,20 +1028,13 @@ static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb)
 	}
 }
 
-static int ccid3_hc_rx_init(struct sock *sk)
+static int ccid3_hc_rx_init(struct ccid *ccid, struct sock *sk)
 {
 	struct dccp_sock *dp = dccp_sk(sk);
-	struct ccid3_hc_rx_sock *hcrx;
+	struct ccid3_hc_rx_sock *hcrx = ccid_priv(ccid);
 
 	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;
@@ -1071,7 +1053,6 @@ static int ccid3_hc_rx_init(struct sock *sk)
 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);
 
@@ -1082,9 +1063,6 @@ static void ccid3_hc_rx_exit(struct sock *sk)
 
 	/* 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)
@@ -1170,10 +1148,11 @@ static int ccid3_hc_tx_getsockopt(struct sock *sk, const int optname, int len,
 	return 0;
 }
 
-static struct ccid ccid3 = {
+static struct ccid_operations ccid3 = {
 	.ccid_id		   = 3,
 	.ccid_name		   = "ccid3",
 	.ccid_owner		   = THIS_MODULE,
+	.ccid_hc_tx_obj_size	   = sizeof(struct ccid3_hc_tx_sock),
 	.ccid_hc_tx_init	   = ccid3_hc_tx_init,
 	.ccid_hc_tx_exit	   = ccid3_hc_tx_exit,
 	.ccid_hc_tx_send_packet	   = ccid3_hc_tx_send_packet,
@@ -1181,6 +1160,7 @@ static struct ccid ccid3 = {
 	.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_obj_size	   = sizeof(struct ccid3_hc_rx_sock),
 	.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,
diff --git a/net/dccp/ccids/ccid3.h b/net/dccp/ccids/ccid3.h
index 0bde4583d09..f18b96d4e5a 100644
--- a/net/dccp/ccids/ccid3.h
+++ b/net/dccp/ccids/ccid3.h
@@ -41,6 +41,7 @@
 #include <linux/time.h>
 #include <linux/types.h>
 #include <linux/tfrc.h>
+#include "../ccid.h"
 
 #define TFRC_MIN_PACKET_SIZE	   16
 #define TFRC_STD_PACKET_SIZE	  256
@@ -135,12 +136,12 @@ struct ccid3_hc_rx_sock {
 
 static inline struct ccid3_hc_tx_sock *ccid3_hc_tx_sk(const struct sock *sk)
 {
-    return dccp_sk(sk)->dccps_hc_tx_ccid_private;
+    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 dccp_sk(sk)->dccps_hc_rx_ccid_private;
+    return ccid_priv(dccp_sk(sk)->dccps_hc_rx_ccid);
 }
 
 #endif /* _DCCP_CCID3_H_ */
diff --git a/net/dccp/input.c b/net/dccp/input.c
index 4b6d43d8b92..67691a0592a 100644
--- a/net/dccp/input.c
+++ b/net/dccp/input.c
@@ -324,14 +324,6 @@ static int dccp_rcv_request_sent_state_process(struct sock *sk,
 		dccp_set_seqno(&dp->dccps_swl,
 			       max48(dp->dccps_swl, dp->dccps_isr));
 
-		if (ccid_hc_rx_init(dp->dccps_hc_rx_ccid, sk) != 0 ||
-		    ccid_hc_tx_init(dp->dccps_hc_tx_ccid, sk) != 0) {
-			ccid_hc_rx_exit(dp->dccps_hc_rx_ccid, sk);
-			ccid_hc_tx_exit(dp->dccps_hc_tx_ccid, sk);
-			/* FIXME: send appropriate RESET code */
-			goto out_invalid_packet;
-		}
-
 		dccp_sync_mss(sk, icsk->icsk_pmtu_cookie);
 
 		/*
diff --git a/net/dccp/ipv4.c b/net/dccp/ipv4.c
index fcfb486f90c..aa7708fed32 100644
--- a/net/dccp/ipv4.c
+++ b/net/dccp/ipv4.c
@@ -1058,14 +1058,16 @@ int dccp_v4_init_sock(struct sock *sk)
 			if (dp->dccps_hc_rx_ackvec == NULL)
 				return -ENOMEM;
 		}
-		dp->dccps_hc_rx_ccid = ccid_init(dp->dccps_options.dccpo_rx_ccid,
-						 sk);
-		dp->dccps_hc_tx_ccid = ccid_init(dp->dccps_options.dccpo_tx_ccid,
-						 sk);
-	    	if (dp->dccps_hc_rx_ccid == NULL ||
-		    dp->dccps_hc_tx_ccid == NULL) {
-			ccid_exit(dp->dccps_hc_rx_ccid, sk);
-			ccid_exit(dp->dccps_hc_tx_ccid, sk);
+		dp->dccps_hc_rx_ccid =
+				ccid_hc_rx_new(dp->dccps_options.dccpo_rx_ccid,
+					       sk, GFP_KERNEL);
+		dp->dccps_hc_tx_ccid =
+				ccid_hc_tx_new(dp->dccps_options.dccpo_tx_ccid,
+					       sk, GFP_KERNEL);
+	    	if (unlikely(dp->dccps_hc_rx_ccid == NULL ||
+			     dp->dccps_hc_tx_ccid == NULL)) {
+			ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk);
+			ccid_hc_tx_delete(dp->dccps_hc_tx_ccid, sk);
 			if (dp->dccps_options.dccpo_send_ack_vector) {
 				dccp_ackvec_free(dp->dccps_hc_rx_ackvec);
 				dp->dccps_hc_rx_ackvec = NULL;
@@ -1120,14 +1122,12 @@ int dccp_v4_destroy_sock(struct sock *sk)
 	kfree(dp->dccps_service_list);
 	dp->dccps_service_list = NULL;
 
-	ccid_hc_rx_exit(dp->dccps_hc_rx_ccid, sk);
-	ccid_hc_tx_exit(dp->dccps_hc_tx_ccid, sk);
 	if (dp->dccps_options.dccpo_send_ack_vector) {
 		dccp_ackvec_free(dp->dccps_hc_rx_ackvec);
 		dp->dccps_hc_rx_ackvec = NULL;
 	}
-	ccid_exit(dp->dccps_hc_rx_ccid, sk);
-	ccid_exit(dp->dccps_hc_tx_ccid, sk);
+	ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk);
+	ccid_hc_tx_delete(dp->dccps_hc_tx_ccid, sk);
 	dp->dccps_hc_rx_ccid = dp->dccps_hc_tx_ccid = NULL;
 
 	/* clean up feature negotiation state */
diff --git a/net/dccp/minisocks.c b/net/dccp/minisocks.c
index 9e1de5919ee..5324fcacb34 100644
--- a/net/dccp/minisocks.c
+++ b/net/dccp/minisocks.c
@@ -121,23 +121,21 @@ struct sock *dccp_create_openreq_child(struct sock *sk,
 		if (newdp->dccps_options.dccpo_send_ack_vector) {
 			newdp->dccps_hc_rx_ackvec =
 						dccp_ackvec_alloc(GFP_ATOMIC);
-			/*
-			 * XXX: We're using the same CCIDs set on the parent,
-			 * i.e. sk_clone copied the master sock and left the
-			 * CCID pointers for this child, that is why we do the
-			 * __ccid_get calls.
-			 */
 			if (unlikely(newdp->dccps_hc_rx_ackvec == NULL))
 				goto out_free;
 		}
 
-		if (unlikely(ccid_hc_rx_init(newdp->dccps_hc_rx_ccid,
-					     newsk) != 0 ||
-			     ccid_hc_tx_init(newdp->dccps_hc_tx_ccid,
-				     	     newsk) != 0)) {
+		newdp->dccps_hc_rx_ccid =
+			    ccid_hc_rx_new(newdp->dccps_options.dccpo_rx_ccid,
+					   newsk, GFP_ATOMIC);
+		newdp->dccps_hc_tx_ccid =
+			    ccid_hc_tx_new(newdp->dccps_options.dccpo_tx_ccid,
+					   newsk, GFP_ATOMIC);
+		if (unlikely(newdp->dccps_hc_rx_ccid == NULL ||
+			     newdp->dccps_hc_tx_ccid == NULL)) {
 			dccp_ackvec_free(newdp->dccps_hc_rx_ackvec);
-			ccid_hc_rx_exit(newdp->dccps_hc_rx_ccid, newsk);
-			ccid_hc_tx_exit(newdp->dccps_hc_tx_ccid, newsk);
+			ccid_hc_rx_delete(newdp->dccps_hc_rx_ccid, newsk);
+			ccid_hc_tx_delete(newdp->dccps_hc_tx_ccid, newsk);
 out_free:
 			/* It is still raw copy of parent, so invalidate
 			 * destructor and make plain sk_free() */
@@ -146,9 +144,6 @@ out_free:
 			return NULL;
 		}
 
-		__ccid_get(newdp->dccps_hc_rx_ccid);
-		__ccid_get(newdp->dccps_hc_tx_ccid);
-
 		/*
 		 * Step 3: Process LISTEN state
 		 *
-- 
cgit v1.2.3-70-g09d2


From c0c736db7ef4a7bdc1a28f3de751cc7e9f720313 Mon Sep 17 00:00:00 2001
From: Arnaldo Carvalho de Melo <acme@mandriva.com>
Date: Mon, 20 Mar 2006 22:05:37 -0800
Subject: [DCCP] ccid2: coding style cleanups

No changes in the logic where made.

Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 net/dccp/ccids/ccid2.c | 76 +++++++++++++++++---------------------------------
 1 file changed, 26 insertions(+), 50 deletions(-)

(limited to 'net/dccp/ccids/ccid2.c')

diff --git a/net/dccp/ccids/ccid2.c b/net/dccp/ccids/ccid2.c
index b40c4569a82..d4f9e2d3345 100644
--- a/net/dccp/ccids/ccid2.c
+++ b/net/dccp/ccids/ccid2.c
@@ -37,10 +37,7 @@
 
 static int ccid2_debug;
 
-#if 0
-#define CCID2_DEBUG
-#endif
-
+#undef CCID2_DEBUG
 #ifdef CCID2_DEBUG
 #define ccid2_pr_debug(format, a...) \
         do { if (ccid2_debug) \
@@ -56,10 +53,8 @@ static const int ccid2_seq_len = 128;
 static void ccid2_hc_tx_check_sanity(const struct ccid2_hc_tx_sock *hctx)
 {
 	int len = 0;
-	struct ccid2_seq *seqp;
 	int pipe = 0;
-
-	seqp = hctx->ccid2hctx_seqh;
+	struct ccid2_seq *seqp = hctx->ccid2hctx_seqh;
 
 	/* there is data in the chain */
 	if (seqp != hctx->ccid2hctx_seqt) {
@@ -69,9 +64,8 @@ static void ccid2_hc_tx_check_sanity(const struct ccid2_hc_tx_sock *hctx)
 			pipe++;
 
 		while (seqp != hctx->ccid2hctx_seqt) {
-			struct ccid2_seq *prev;
+			struct ccid2_seq *prev = seqp->ccid2s_prev;
 
-			prev = seqp->ccid2s_prev;
 			len++;
 			if (!prev->ccid2s_acked)
 				pipe++;
@@ -92,7 +86,7 @@ static void ccid2_hc_tx_check_sanity(const struct ccid2_hc_tx_sock *hctx)
 		seqp = seqp->ccid2s_prev;
 		len++;
 		BUG_ON(len > ccid2_seq_len);
-	} while(seqp != hctx->ccid2hctx_seqh);
+	} while (seqp != hctx->ccid2hctx_seqh);
 
 	BUG_ON(len != ccid2_seq_len);
 	ccid2_pr_debug("total len=%d\n", len);
@@ -141,7 +135,7 @@ static void ccid2_change_l_ack_ratio(struct sock *sk, int val)
 	 * -sorbo.
 	 */
 	if (val != 2) {
-		struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk);
+		const struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk);
 		int max = hctx->ccid2hctx_cwnd / 2;
 
 		/* round up */
@@ -179,9 +173,6 @@ static void ccid2_hc_tx_rto_expire(unsigned long data)
 	struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk);
 	long s;
 
-	/* XXX I don't think i'm locking correctly
-	 * -sorbo.
-	 */
 	bh_lock_sock(sk);
 	if (sock_owned_by_user(sk)) {
 		sk_reset_timer(sk, &hctx->ccid2hctx_rtotimer,
@@ -278,36 +269,33 @@ static void ccid2_hc_tx_packet_sent(struct sock *sk, int more, int len)
 	/* We had an ack loss in this window... */
 	if (hctx->ccid2hctx_ackloss) {
 		if (hctx->ccid2hctx_arsent >= hctx->ccid2hctx_cwnd) {
-			hctx->ccid2hctx_arsent = 0;
-			hctx->ccid2hctx_ackloss = 0;
+			hctx->ccid2hctx_arsent	= 0;
+			hctx->ccid2hctx_ackloss	= 0;
 		}
-	}
-	/* No acks lost up to now... */
-	else {
+	} 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;
+			int denom = dp->dccps_l_ack_ratio * dp->dccps_l_ack_ratio -
+				    dp->dccps_l_ack_ratio;
 
-			denom = dp->dccps_l_ack_ratio * dp->dccps_l_ack_ratio -
-				dp->dccps_l_ack_ratio;
 			denom = hctx->ccid2hctx_cwnd * hctx->ccid2hctx_cwnd / denom;
 
 			if (hctx->ccid2hctx_arsent >= denom) {
 				ccid2_change_l_ack_ratio(sk, dp->dccps_l_ack_ratio - 1);
 				hctx->ccid2hctx_arsent = 0;
 			}
-		}
-		/* we can't increase ack ratio further [1] */
-		else {
+		} else {
+			/* we can't increase ack ratio further [1] */
 			hctx->ccid2hctx_arsent = 0; /* or maybe set it to cwnd*/
 		}
 	}
 
 	/* setup RTO timer */
-	if (!timer_pending(&hctx->ccid2hctx_rtotimer)) {
+	if (!timer_pending(&hctx->ccid2hctx_rtotimer))
 		ccid2_start_rto_timer(sk);
-	}
+
 #ifdef CCID2_DEBUG
 	ccid2_pr_debug("pipe=%d\n", hctx->ccid2hctx_pipe);
 	ccid2_pr_debug("Sent: seq=%llu\n", seq);
@@ -320,7 +308,7 @@ static void ccid2_hc_tx_packet_sent(struct sock *sk, int more, int len)
 				       seqp->ccid2s_sent);
 			seqp = seqp->ccid2s_next;
 		}
-	} while(0);
+	} while (0);
 	ccid2_pr_debug("=========\n");
 	ccid2_hc_tx_check_sanity(hctx);
 #endif
@@ -378,7 +366,6 @@ static int ccid2_ackvector(struct sock *sk, struct sk_buff *skb, int offset,
 			*vec	= value;
 			*veclen = len;
 			return offset + (opt_ptr - options);
-			break;
 		}
 	}
 
@@ -416,13 +403,11 @@ static inline void ccid2_new_ack(struct sock *sk,
 				hctx->ccid2hctx_ssacks = 0;
 				*maxincr = *maxincr - 1;
 			}
-		}
-		/* increased cwnd enough for this single ack */
-		else {
+		} else {
+			/* increased cwnd enough for this single ack */
 			hctx->ccid2hctx_ssacks = 0;
 		}
-	}
-	else {
+	} else {
 		hctx->ccid2hctx_ssacks = 0;
 		hctx->ccid2hctx_acks++;
 
@@ -444,8 +429,7 @@ static inline void ccid2_new_ack(struct sock *sk,
 			       	       r, jiffies, seqp->ccid2s_seq);
 			hctx->ccid2hctx_srtt = r;
 			hctx->ccid2hctx_rttvar = r >> 1;
-		}
-		else {
+		} else {
 			/* RTTVAR */
 			long tmp = hctx->ccid2hctx_srtt - r;
 			if (tmp < 0)
@@ -528,12 +512,10 @@ static void ccid2_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb)
 	if (hctx->ccid2hctx_rpdupack == -1) {
 		hctx->ccid2hctx_rpdupack = 0;
 		hctx->ccid2hctx_rpseq = seqno;
-	}
-	else {
+	} else {
 		/* check if packet is consecutive */
-		if ((hctx->ccid2hctx_rpseq + 1) == seqno) {
+		if ((hctx->ccid2hctx_rpseq + 1) == seqno)
 			hctx->ccid2hctx_rpseq++;
-		}
 		/* it's a later packet */
 		else if (after48(seqno, hctx->ccid2hctx_rpseq)) {
 			hctx->ccid2hctx_rpdupack++;
@@ -541,7 +523,6 @@ static void ccid2_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb)
 			/* check if we got enough dupacks */
 			if (hctx->ccid2hctx_rpdupack >=
 			    hctx->ccid2hctx_numdupack) {
-
 				hctx->ccid2hctx_rpdupack = -1; /* XXX lame */
 				hctx->ccid2hctx_rpseq = 0;
 
@@ -559,7 +540,6 @@ static void ccid2_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb)
 	case DCCP_PKT_ACK:
 	case DCCP_PKT_DATAACK:
 		break;
-
 	default:
 		return;
 	}
@@ -612,11 +592,9 @@ static void ccid2_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb)
 				    	if (state ==
 					    DCCP_ACKVEC_STATE_ECN_MARKED) {
 						loss = 1;
-					}
-					else {
+					} else
 						ccid2_new_ack(sk, seqp,
 							      &maxincr);
-					}
 
 					seqp->ccid2s_acked = 1;
 					ccid2_pr_debug("Got ack for %llu\n",
@@ -648,13 +626,11 @@ static void ccid2_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb)
 	while (1) {
 		if (seqp->ccid2s_acked) {
 			done++;
-			if (done == hctx->ccid2hctx_numdupack) {
+			if (done == hctx->ccid2hctx_numdupack)
 				break;
-			}
 		}
-		if (seqp == hctx->ccid2hctx_seqt) {
+		if (seqp == hctx->ccid2hctx_seqt)
 			break;
-		}
 		seqp = seqp->ccid2s_prev;
 	}
 
@@ -798,6 +774,6 @@ static __exit void ccid2_module_exit(void)
 module_exit(ccid2_module_exit);
 
 MODULE_AUTHOR("Andrea Bittau <a.bittau@cs.ucl.ac.uk>");
-MODULE_DESCRIPTION("DCCP TCP CCID2 CCID");
+MODULE_DESCRIPTION("DCCP TCP-Like (CCID2) CCID");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS("net-dccp-ccid-2");
-- 
cgit v1.2.3-70-g09d2