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8a508ac26e
kernel-ark/net/dccp/ccids/ccid3.c
Gerrit Renker 8a508ac26e [DCCP]: Use higher RTO default for CCID3 
The TFRC nofeedback timer normally expires after the maximum of 4
RTTs and twice the current send interval (RFC 3448, 4.3). On LANs
with a small RTT this can mean a high processing load and reduced
performance, since then the nofeedback timer is triggered very
frequently.

This patch provides a configuration option to set the bound for the
nofeedback timer, using as default 100 milliseconds.

By setting the configuration option to 0, strict RFC 3448 behaviour
can be enforced for the nofeedback timer.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
2006-12-03 14:50:23 -02:00

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/*
* net/dccp/ccids/ccid3.c
*
* Copyright (c) 2005 The University of Waikato, Hamilton, New Zealand.
* Copyright (c) 2005-6 Ian McDonald <ian.mcdonald@jandi.co.nz>
*
* An implementation of the DCCP protocol
*
* This code has been developed by the University of Waikato WAND
* research group. For further information please see http://www.wand.net.nz/
*
* This code also uses code from Lulea University, rereleased as GPL by its
* authors:
* Copyright (c) 2003 Nils-Erik Mattsson, Joacim Haggmark, Magnus Erixzon
*
* Changes to meet Linux coding standards, to make it meet latest ccid3 draft
* and to make it work as a loadable module in the DCCP stack written by
* Arnaldo Carvalho de Melo <acme@conectiva.com.br>.
*
* Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include "../ccid.h"
#include "../dccp.h"
#include "lib/packet_history.h"
#include "lib/loss_interval.h"
#include "lib/tfrc.h"
#include "ccid3.h"
/*
* Reason for maths here is to avoid 32 bit overflow when a is big.
* With this we get close to the limit.
*/
static u32 usecs_div(const u32 a, const u32 b)
{
const u32 div = a < (UINT_MAX / (USEC_PER_SEC / 10)) ? 10 :
a < (UINT_MAX / (USEC_PER_SEC / 50)) ? 50 :
a < (UINT_MAX / (USEC_PER_SEC / 100)) ? 100 :
a < (UINT_MAX / (USEC_PER_SEC / 500)) ? 500 :
a < (UINT_MAX / (USEC_PER_SEC / 1000)) ? 1000 :
a < (UINT_MAX / (USEC_PER_SEC / 5000)) ? 5000 :
a < (UINT_MAX / (USEC_PER_SEC / 10000)) ? 10000 :
a < (UINT_MAX / (USEC_PER_SEC / 50000)) ? 50000 :
100000;
const u32 tmp = a * (USEC_PER_SEC / div);
return (b >= 2 * div) ? tmp / (b / div) : tmp;
}
#ifdef CONFIG_IP_DCCP_CCID3_DEBUG
static int ccid3_debug;
#define ccid3_pr_debug(format, a...) DCCP_PR_DEBUG(ccid3_debug, format, ##a)
#else
#define ccid3_pr_debug(format, a...)
#endif
static struct dccp_tx_hist *ccid3_tx_hist;
static struct dccp_rx_hist *ccid3_rx_hist;
static struct dccp_li_hist *ccid3_li_hist;
#ifdef CONFIG_IP_DCCP_CCID3_DEBUG
static const char *ccid3_tx_state_name(enum ccid3_hc_tx_states state)
{
static char *ccid3_state_names[] = {
[TFRC_SSTATE_NO_SENT] = "NO_SENT",
[TFRC_SSTATE_NO_FBACK] = "NO_FBACK",
[TFRC_SSTATE_FBACK] = "FBACK",
[TFRC_SSTATE_TERM] = "TERM",
};
return ccid3_state_names[state];
}
#endif
static void ccid3_hc_tx_set_state(struct sock *sk,
enum ccid3_hc_tx_states state)
{
struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
enum ccid3_hc_tx_states oldstate = hctx->ccid3hctx_state;
ccid3_pr_debug("%s(%p) %-8.8s -> %s\n",
dccp_role(sk), sk, ccid3_tx_state_name(oldstate),
ccid3_tx_state_name(state));
WARN_ON(state == oldstate);
hctx->ccid3hctx_state = state;
}
/*
* Recalculate scheduled nominal send time t_nom, inter-packet interval
* t_ipi, and delta value. Should be called after each change to X.
*/
static inline void ccid3_update_send_time(struct ccid3_hc_tx_sock *hctx)
{
timeval_sub_usecs(&hctx->ccid3hctx_t_nom, hctx->ccid3hctx_t_ipi);
/* Calculate new t_ipi (inter packet interval) by t_ipi = s / X_inst */
hctx->ccid3hctx_t_ipi = usecs_div(hctx->ccid3hctx_s, hctx->ccid3hctx_x);
/* Update nominal send time with regard to the new t_ipi */
timeval_add_usecs(&hctx->ccid3hctx_t_nom, hctx->ccid3hctx_t_ipi);
/* Calculate new delta by delta = min(t_ipi / 2, t_gran / 2) */
hctx->ccid3hctx_delta = min_t(u32, hctx->ccid3hctx_t_ipi / 2,
TFRC_OPSYS_HALF_TIME_GRAN);
}
/*
* Update X by
* If (p > 0)
* x_calc = calcX(s, R, p);
* X = max(min(X_calc, 2 * X_recv), s / t_mbi);
* Else
* If (now - tld >= R)
* X = max(min(2 * X, 2 * X_recv), s / R);
* tld = now;
*/
static void ccid3_hc_tx_update_x(struct sock *sk, struct timeval *now)
{
struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
const __u32 old_x = hctx->ccid3hctx_x;
/* To avoid large error in calcX */
if (hctx->ccid3hctx_p >= TFRC_SMALLEST_P) {
hctx->ccid3hctx_x_calc = tfrc_calc_x(hctx->ccid3hctx_s,
hctx->ccid3hctx_rtt,
hctx->ccid3hctx_p);
hctx->ccid3hctx_x = max_t(u32, min(hctx->ccid3hctx_x_calc,
hctx->ccid3hctx_x_recv * 2),
hctx->ccid3hctx_s / TFRC_T_MBI);
} else if (timeval_delta(now, &hctx->ccid3hctx_t_ld) >=
hctx->ccid3hctx_rtt) {
hctx->ccid3hctx_x = max(min(hctx->ccid3hctx_x_recv,
hctx->ccid3hctx_x ) * 2,
usecs_div(hctx->ccid3hctx_s,
hctx->ccid3hctx_rtt) );
hctx->ccid3hctx_t_ld = *now;
} else
ccid3_pr_debug("Not changing X\n");
if (hctx->ccid3hctx_x != old_x)
ccid3_update_send_time(hctx);
}
/*
* Track the mean packet size `s' (cf. RFC 4342, 5.3 and RFC 3448, 4.1)
* @len: DCCP packet payload size in bytes
*/
static inline void ccid3_hc_tx_update_s(struct ccid3_hc_tx_sock *hctx, int len)
{
if (unlikely(len == 0))
ccid3_pr_debug("Packet payload length is 0 - not updating\n");
else
hctx->ccid3hctx_s = hctx->ccid3hctx_s == 0 ? len :
(9 * hctx->ccid3hctx_s + len) / 10;
/*
* Note: We could do a potential optimisation here - when `s' changes,
* recalculate sending rate and consequently t_ipi, t_delta, and
* t_now. This is however non-standard, and the benefits are not
* clear, so it is currently left out.
*/
}
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);
unsigned long t_nfb = USEC_PER_SEC / 5;
bh_lock_sock(sk);
if (sock_owned_by_user(sk)) {
/* Try again later. */
/* XXX: set some sensible MIB */
goto restart_timer;
}
ccid3_pr_debug("%s, sk=%p, state=%s\n", dccp_role(sk), sk,
ccid3_tx_state_name(hctx->ccid3hctx_state));
switch (hctx->ccid3hctx_state) {
case TFRC_SSTATE_NO_FBACK:
/* RFC 3448, 4.4: Halve send rate directly */
hctx->ccid3hctx_x = min_t(u32, hctx->ccid3hctx_x / 2,
hctx->ccid3hctx_s / TFRC_T_MBI);
ccid3_pr_debug("%s, sk=%p, state=%s, updated tx rate to %d "
"bytes/s\n",
dccp_role(sk), sk,
ccid3_tx_state_name(hctx->ccid3hctx_state),
hctx->ccid3hctx_x);
/* The value of R is still undefined and so we can not recompute
* the timout value. Keep initial value as per [RFC 4342, 5]. */
t_nfb = TFRC_INITIAL_TIMEOUT;
ccid3_update_send_time(hctx);
break;
case TFRC_SSTATE_FBACK:
/*
* Check if IDLE since last timeout and recv rate is less than
* 4 packets per RTT
*/
if (!hctx->ccid3hctx_idle ||
(hctx->ccid3hctx_x_recv >=
4 * usecs_div(hctx->ccid3hctx_s, hctx->ccid3hctx_rtt))) {
struct timeval now;
ccid3_pr_debug("%s, sk=%p, state=%s, not idle\n",
dccp_role(sk), sk,
ccid3_tx_state_name(hctx->ccid3hctx_state));
/* Halve sending rate */
/* If (X_calc > 2 * X_recv)
* X_recv = max(X_recv / 2, s / (2 * t_mbi));
* Else
* X_recv = X_calc / 4;
*/
BUG_ON(hctx->ccid3hctx_p >= TFRC_SMALLEST_P &&
hctx->ccid3hctx_x_calc == 0);
/* check also if p is zero -> x_calc is infinity? */
if (hctx->ccid3hctx_p < TFRC_SMALLEST_P ||
hctx->ccid3hctx_x_calc > 2 * hctx->ccid3hctx_x_recv)
hctx->ccid3hctx_x_recv = max_t(u32, hctx->ccid3hctx_x_recv / 2,
hctx->ccid3hctx_s / (2 * TFRC_T_MBI));
else
hctx->ccid3hctx_x_recv = hctx->ccid3hctx_x_calc / 4;
/* Update sending rate */
dccp_timestamp(sk, &now);
ccid3_hc_tx_update_x(sk, &now);
}
/*
* Schedule no feedback timer to expire in
* max(t_RTO, 2 * s/X) = max(t_RTO, 2 * t_ipi)
* See comments in packet_recv() regarding the value of t_RTO.
*/
t_nfb = max(hctx->ccid3hctx_t_rto, 2 * hctx->ccid3hctx_t_ipi);
break;
case TFRC_SSTATE_NO_SENT:
DCCP_BUG("Illegal %s state NO_SENT, sk=%p", dccp_role(sk), sk);
/* fall through */
case TFRC_SSTATE_TERM:
goto out;
}
hctx->ccid3hctx_idle = 1;
restart_timer:
sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer,
jiffies + usecs_to_jiffies(t_nfb));
out:
bh_unlock_sock(sk);
sock_put(sk);
}
/*
* returns
* > 0: delay (in msecs) that should pass before actually sending
* = 0: can send immediately
* < 0: error condition; do not send packet
*/
static int ccid3_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb)
{
struct dccp_sock *dp = dccp_sk(sk);
struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
struct dccp_tx_hist_entry *new_packet;
struct timeval now;
long 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
* control this case is pathological - ignore it.
*/
if (unlikely(skb->len == 0))
return -EBADMSG;
/* See if last packet allocated was not sent */
new_packet = dccp_tx_hist_head(&hctx->ccid3hctx_hist);
if (new_packet == NULL || new_packet->dccphtx_sent) {
new_packet = dccp_tx_hist_entry_new(ccid3_tx_hist,
SLAB_ATOMIC);
if (unlikely(new_packet == NULL)) {
DCCP_WARN("%s, sk=%p, not enough mem to add to history,"
"send refused\n", dccp_role(sk), sk);
return -ENOBUFS;
}
dccp_tx_hist_add_entry(&hctx->ccid3hctx_hist, new_packet);
}
dccp_timestamp(sk, &now);
switch (hctx->ccid3hctx_state) {
case TFRC_SSTATE_NO_SENT:
sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer,
jiffies + usecs_to_jiffies(TFRC_INITIAL_TIMEOUT));
hctx->ccid3hctx_last_win_count = 0;
hctx->ccid3hctx_t_last_win_count = now;
ccid3_hc_tx_set_state(sk, TFRC_SSTATE_NO_FBACK);
/* Set initial sending rate to 1 packet per second */
ccid3_hc_tx_update_s(hctx, skb->len);
hctx->ccid3hctx_x = hctx->ccid3hctx_s;
/* First timeout, according to [RFC 3448, 4.2], is 1 second */
hctx->ccid3hctx_t_ipi = USEC_PER_SEC;
/* Initial delta: minimum of 0.5 sec and t_gran/2 */
hctx->ccid3hctx_delta = TFRC_OPSYS_HALF_TIME_GRAN;
/* Set t_0 for initial packet */
hctx->ccid3hctx_t_nom = now;
break;
case TFRC_SSTATE_NO_FBACK:
case TFRC_SSTATE_FBACK:
delay = timeval_delta(&hctx->ccid3hctx_t_nom, &now);
/*
* Scheduling of packet transmissions [RFC 3448, 4.6]
*
* if (t_now > t_nom - delta)
* // send the packet now
* else
* // send the packet in (t_nom - t_now) milliseconds.
*/
if (delay >= hctx->ccid3hctx_delta)
return delay / 1000L;
break;
case TFRC_SSTATE_TERM:
DCCP_BUG("Illegal %s state TERM, sk=%p", dccp_role(sk), sk);
return -EINVAL;
}
/* prepare to send now (add options etc.) */
dp->dccps_hc_tx_insert_options = 1;
new_packet->dccphtx_ccval = DCCP_SKB_CB(skb)->dccpd_ccval =
hctx->ccid3hctx_last_win_count;
timeval_add_usecs(&hctx->ccid3hctx_t_nom, hctx->ccid3hctx_t_ipi);
return 0;
}
static void ccid3_hc_tx_packet_sent(struct sock *sk, int more, unsigned int len)
{
const struct dccp_sock *dp = dccp_sk(sk);
struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
struct timeval now;
unsigned long quarter_rtt;
struct dccp_tx_hist_entry *packet;
BUG_ON(hctx == NULL);
dccp_timestamp(sk, &now);
ccid3_hc_tx_update_s(hctx, len);
packet = dccp_tx_hist_head(&hctx->ccid3hctx_hist);
if (unlikely(packet == NULL)) {
DCCP_WARN("packet doesn't exist in history!\n");
return;
}
if (unlikely(packet->dccphtx_sent)) {
DCCP_WARN("no unsent packet in history!\n");
return;
}
packet->dccphtx_tstamp = now;
packet->dccphtx_seqno = dp->dccps_gss;
/*
* Check if win_count have changed
* Algorithm in "8.1. Window Counter Value" in RFC 4342.
*/
quarter_rtt = timeval_delta(&now, &hctx->ccid3hctx_t_last_win_count);
if (likely(hctx->ccid3hctx_rtt > 8))
quarter_rtt /= hctx->ccid3hctx_rtt / 4;
if (quarter_rtt > 0) {
hctx->ccid3hctx_t_last_win_count = now;
hctx->ccid3hctx_last_win_count = (hctx->ccid3hctx_last_win_count +
min_t(unsigned long, quarter_rtt, 5)) % 16;
ccid3_pr_debug("%s, sk=%p, window changed from "
"%u to %u!\n",
dccp_role(sk), sk,
packet->dccphtx_ccval,
hctx->ccid3hctx_last_win_count);
}
hctx->ccid3hctx_idle = 0;
packet->dccphtx_rtt = hctx->ccid3hctx_rtt;
packet->dccphtx_sent = 1;
}
static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb)
{
const struct dccp_sock *dp = dccp_sk(sk);
struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
struct ccid3_options_received *opt_recv;
struct dccp_tx_hist_entry *packet;
struct timeval now;
unsigned long t_nfb;
u32 t_elapsed;
u32 pinv;
u32 x_recv;
u32 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))
return;
opt_recv = &hctx->ccid3hctx_options_received;
t_elapsed = dp->dccps_options_received.dccpor_elapsed_time * 10;
x_recv = opt_recv->ccid3or_receive_rate;
pinv = opt_recv->ccid3or_loss_event_rate;
switch (hctx->ccid3hctx_state) {
case TFRC_SSTATE_NO_FBACK:
case TFRC_SSTATE_FBACK:
/* Calculate new round trip sample by
* R_sample = (now - t_recvdata) - t_delay */
/* get t_recvdata from history */
packet = dccp_tx_hist_find_entry(&hctx->ccid3hctx_hist,
DCCP_SKB_CB(skb)->dccpd_ack_seq);
if (unlikely(packet == NULL)) {
DCCP_WARN("%s, sk=%p, seqno %llu(%s) does't exist "
"in history!\n", dccp_role(sk), sk,
(unsigned long long)DCCP_SKB_CB(skb)->dccpd_ack_seq,
dccp_packet_name(DCCP_SKB_CB(skb)->dccpd_type));
return;
}
/* Update RTT */
dccp_timestamp(sk, &now);
r_sample = timeval_delta(&now, &packet->dccphtx_tstamp);
if (unlikely(r_sample <= t_elapsed))
DCCP_WARN("r_sample=%uus,t_elapsed=%uus\n",
r_sample, t_elapsed);
else
r_sample -= t_elapsed;
/* Update RTT estimate by
* If (No feedback recv)
* R = R_sample;
* Else
* R = q * R + (1 - q) * R_sample;
*
* q is a constant, RFC 3448 recomments 0.9
*/
if (hctx->ccid3hctx_state == TFRC_SSTATE_NO_FBACK) {
/* Use Larger Initial Windows [RFC 4342, sec. 5]
* We deviate in that we use `s' instead of `MSS'. */
u16 w_init = max( 4 * hctx->ccid3hctx_s,
max(2 * hctx->ccid3hctx_s, 4380));
hctx->ccid3hctx_rtt = r_sample;
hctx->ccid3hctx_x = usecs_div(w_init, r_sample);
hctx->ccid3hctx_t_ld = now;
ccid3_update_send_time(hctx);
ccid3_hc_tx_set_state(sk, TFRC_SSTATE_FBACK);
} else {
hctx->ccid3hctx_rtt = (hctx->ccid3hctx_rtt * 9) / 10 +
r_sample / 10;
ccid3_hc_tx_update_x(sk, &now);
}
ccid3_pr_debug("%s, sk=%p, New RTT estimate=%uus, "
"r_sample=%us\n", dccp_role(sk), sk,
hctx->ccid3hctx_rtt, r_sample);
/* Update receive rate */
hctx->ccid3hctx_x_recv = x_recv;/* X_recv in bytes per sec */
/* Update loss event rate */
if (pinv == ~0 || pinv == 0)
hctx->ccid3hctx_p = 0;
else {
hctx->ccid3hctx_p = 1000000 / pinv;
if (hctx->ccid3hctx_p < TFRC_SMALLEST_P) {
hctx->ccid3hctx_p = TFRC_SMALLEST_P;
ccid3_pr_debug("%s, sk=%p, Smallest p used!\n",
dccp_role(sk), sk);
}
}
/* unschedule no feedback timer */
sk_stop_timer(sk, &hctx->ccid3hctx_no_feedback_timer);
/* remove all packets older than the one acked from history */
dccp_tx_hist_purge_older(ccid3_tx_hist,
&hctx->ccid3hctx_hist, packet);
/*
* As we have calculated new ipi, delta, t_nom it is possible that
* we now can send a packet, so wake up dccp_wait_for_ccid
*/
sk->sk_write_space(sk);
/*
* Update timeout interval for the nofeedback timer.
* We use a configuration option to increase the lower bound.
* This can help avoid triggering the nofeedback timer too often
* ('spinning') on LANs with small RTTs.
*/
hctx->ccid3hctx_t_rto = max_t(u32, 4 * hctx->ccid3hctx_rtt,
CONFIG_IP_DCCP_CCID3_RTO *
(USEC_PER_SEC/1000) );
/*
* Schedule no feedback timer to expire in
* max(t_RTO, 2 * s/X) = max(t_RTO, 2 * t_ipi)
*/
t_nfb = max(hctx->ccid3hctx_t_rto, 2 * hctx->ccid3hctx_t_ipi);
ccid3_pr_debug("%s, sk=%p, Scheduled no feedback timer to "
"expire in %lu jiffies (%luus)\n",
dccp_role(sk), sk,
usecs_to_jiffies(t_nfb), t_nfb);
sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer,
jiffies + usecs_to_jiffies(t_nfb));
/* set idle flag */
hctx->ccid3hctx_idle = 1;
break;
case TFRC_SSTATE_NO_SENT:
DCCP_WARN("Illegal ACK received - no packet has been sent\n");
/* fall through */
case TFRC_SSTATE_TERM: /* ignore feedback when closing */
break;
}
}
static int ccid3_hc_tx_insert_options(struct sock *sk, struct sk_buff *skb)
{
const struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
BUG_ON(hctx == NULL);
if (sk->sk_state == DCCP_OPEN || sk->sk_state == DCCP_PARTOPEN)
DCCP_SKB_CB(skb)->dccpd_ccval = hctx->ccid3hctx_last_win_count;
return 0;
}
static int ccid3_hc_tx_parse_options(struct sock *sk, unsigned char option,
unsigned char len, u16 idx,
unsigned char *value)
{
int rc = 0;
const struct dccp_sock *dp = dccp_sk(sk);
struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
struct ccid3_options_received *opt_recv;
BUG_ON(hctx == NULL);
opt_recv = &hctx->ccid3hctx_options_received;
if (opt_recv->ccid3or_seqno != dp->dccps_gsr) {
opt_recv->ccid3or_seqno = dp->dccps_gsr;
opt_recv->ccid3or_loss_event_rate = ~0;
opt_recv->ccid3or_loss_intervals_idx = 0;
opt_recv->ccid3or_loss_intervals_len = 0;
opt_recv->ccid3or_receive_rate = 0;
}
switch (option) {
case TFRC_OPT_LOSS_EVENT_RATE:
if (unlikely(len != 4)) {
DCCP_WARN("%s, sk=%p, invalid len %d "
"for TFRC_OPT_LOSS_EVENT_RATE\n",
dccp_role(sk), sk, len);
rc = -EINVAL;
} else {
opt_recv->ccid3or_loss_event_rate = ntohl(*(__be32 *)value);
ccid3_pr_debug("%s, sk=%p, LOSS_EVENT_RATE=%u\n",
dccp_role(sk), sk,
opt_recv->ccid3or_loss_event_rate);
}
break;
case TFRC_OPT_LOSS_INTERVALS:
opt_recv->ccid3or_loss_intervals_idx = idx;
opt_recv->ccid3or_loss_intervals_len = len;
ccid3_pr_debug("%s, sk=%p, LOSS_INTERVALS=(%u, %u)\n",
dccp_role(sk), sk,
opt_recv->ccid3or_loss_intervals_idx,
opt_recv->ccid3or_loss_intervals_len);
break;
case TFRC_OPT_RECEIVE_RATE:
if (unlikely(len != 4)) {
DCCP_WARN("%s, sk=%p, invalid len %d "
"for TFRC_OPT_RECEIVE_RATE\n",
dccp_role(sk), sk, len);
rc = -EINVAL;
} else {
opt_recv->ccid3or_receive_rate = ntohl(*(__be32 *)value);
ccid3_pr_debug("%s, sk=%p, RECEIVE_RATE=%u\n",
dccp_role(sk), sk,
opt_recv->ccid3or_receive_rate);
}
break;
}
return rc;
}
static int ccid3_hc_tx_init(struct ccid *ccid, struct sock *sk)
{
struct ccid3_hc_tx_sock *hctx = ccid_priv(ccid);
hctx->ccid3hctx_s = 0;
hctx->ccid3hctx_state = TFRC_SSTATE_NO_SENT;
INIT_LIST_HEAD(&hctx->ccid3hctx_hist);
hctx->ccid3hctx_no_feedback_timer.function = ccid3_hc_tx_no_feedback_timer;
hctx->ccid3hctx_no_feedback_timer.data = (unsigned long)sk;
init_timer(&hctx->ccid3hctx_no_feedback_timer);
return 0;
}
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);
/* Empty packet history */
dccp_tx_hist_purge(ccid3_tx_hist, &hctx->ccid3hctx_hist);
}
/*
* RX Half Connection methods
*/
#ifdef CONFIG_IP_DCCP_CCID3_DEBUG
static const char *ccid3_rx_state_name(enum ccid3_hc_rx_states state)
{
static char *ccid3_rx_state_names[] = {
[TFRC_RSTATE_NO_DATA] = "NO_DATA",
[TFRC_RSTATE_DATA] = "DATA",
[TFRC_RSTATE_TERM] = "TERM",
};
return ccid3_rx_state_names[state];
}
#endif
static void ccid3_hc_rx_set_state(struct sock *sk,
enum ccid3_hc_rx_states state)
{
struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
enum ccid3_hc_rx_states oldstate = hcrx->ccid3hcrx_state;
ccid3_pr_debug("%s(%p) %-8.8s -> %s\n",
dccp_role(sk), sk, ccid3_rx_state_name(oldstate),
ccid3_rx_state_name(state));
WARN_ON(state == oldstate);
hcrx->ccid3hcrx_state = state;
}
static inline void ccid3_hc_rx_update_s(struct ccid3_hc_rx_sock *hcrx, int len)
{
if (unlikely(len == 0)) /* don't update on empty packets (e.g. ACKs) */
ccid3_pr_debug("Packet payload length is 0 - not updating\n");
else
hcrx->ccid3hcrx_s = hcrx->ccid3hcrx_s == 0 ? len :
(9 * hcrx->ccid3hcrx_s + len) / 10;
}
static void ccid3_hc_rx_send_feedback(struct sock *sk)
{
struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
struct dccp_sock *dp = dccp_sk(sk);
struct dccp_rx_hist_entry *packet;
struct timeval now;
ccid3_pr_debug("%s, sk=%p\n", dccp_role(sk), sk);
dccp_timestamp(sk, &now);
switch (hcrx->ccid3hcrx_state) {
case TFRC_RSTATE_NO_DATA:
hcrx->ccid3hcrx_x_recv = 0;
break;
case TFRC_RSTATE_DATA: {
const u32 delta = timeval_delta(&now,
&hcrx->ccid3hcrx_tstamp_last_feedback);
hcrx->ccid3hcrx_x_recv = usecs_div(hcrx->ccid3hcrx_bytes_recv,
delta);
}
break;
case TFRC_RSTATE_TERM:
DCCP_BUG("Illegal %s state TERM, sk=%p", dccp_role(sk), sk);
return;
}
packet = dccp_rx_hist_find_data_packet(&hcrx->ccid3hcrx_hist);
if (unlikely(packet == NULL)) {
DCCP_WARN("%s, sk=%p, no data packet in history!\n",
dccp_role(sk), sk);
return;
}
hcrx->ccid3hcrx_tstamp_last_feedback = now;
hcrx->ccid3hcrx_ccval_last_counter = packet->dccphrx_ccval;
hcrx->ccid3hcrx_bytes_recv = 0;
/* Convert to multiples of 10us */
hcrx->ccid3hcrx_elapsed_time =
timeval_delta(&now, &packet->dccphrx_tstamp) / 10;
if (hcrx->ccid3hcrx_p == 0)
hcrx->ccid3hcrx_pinv = ~0;
else
hcrx->ccid3hcrx_pinv = 1000000 / hcrx->ccid3hcrx_p;
dp->dccps_hc_rx_insert_options = 1;
dccp_send_ack(sk);
}
static 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);
__be32 x_recv, pinv;
BUG_ON(hcrx == NULL);
if (!(sk->sk_state == DCCP_OPEN || sk->sk_state == DCCP_PARTOPEN))
return 0;
DCCP_SKB_CB(skb)->dccpd_ccval = hcrx->ccid3hcrx_ccval_last_counter;
if (dccp_packet_without_ack(skb))
return 0;
x_recv = htonl(hcrx->ccid3hcrx_x_recv);
pinv = htonl(hcrx->ccid3hcrx_pinv);
if ((hcrx->ccid3hcrx_elapsed_time != 0 &&
dccp_insert_option_elapsed_time(sk, skb,
hcrx->ccid3hcrx_elapsed_time)) ||
dccp_insert_option_timestamp(sk, skb) ||
dccp_insert_option(sk, skb, TFRC_OPT_LOSS_EVENT_RATE,
&pinv, sizeof(pinv)) ||
dccp_insert_option(sk, skb, TFRC_OPT_RECEIVE_RATE,
&x_recv, sizeof(x_recv)))
return -1;
return 0;
}
/* calculate first loss interval
*
* returns estimated loss interval in usecs */
static u32 ccid3_hc_rx_calc_first_li(struct sock *sk)
{
struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
struct dccp_rx_hist_entry *entry, *next, *tail = NULL;
u32 rtt, delta, x_recv, fval, p, tmp2;
struct timeval tstamp = { 0, };
int interval = 0;
int win_count = 0;
int step = 0;
u64 tmp1;
list_for_each_entry_safe(entry, next, &hcrx->ccid3hcrx_hist,
dccphrx_node) {
if (dccp_rx_hist_entry_data_packet(entry)) {
tail = entry;
switch (step) {
case 0:
tstamp = entry->dccphrx_tstamp;
win_count = entry->dccphrx_ccval;
step = 1;
break;
case 1:
interval = win_count - entry->dccphrx_ccval;
if (interval < 0)
interval += TFRC_WIN_COUNT_LIMIT;
if (interval > 4)
goto found;
break;
}
}
}
if (unlikely(step == 0)) {
DCCP_WARN("%s, sk=%p, packet history has no data packets!\n",
dccp_role(sk), sk);
return ~0;
}
if (unlikely(interval == 0)) {
DCCP_WARN("%s, sk=%p, Could not find a win_count interval > 0."
"Defaulting to 1\n", dccp_role(sk), sk);
interval = 1;
}
found:
if (!tail) {
DCCP_CRIT("tail is null\n");
return ~0;
}
rtt = timeval_delta(&tstamp, &tail->dccphrx_tstamp) * 4 / interval;
ccid3_pr_debug("%s, sk=%p, approximated RTT to %uus\n",
dccp_role(sk), sk, rtt);
if (rtt == 0) {
DCCP_WARN("RTT==0, setting to 1\n");
rtt = 1;
}
dccp_timestamp(sk, &tstamp);
delta = timeval_delta(&tstamp, &hcrx->ccid3hcrx_tstamp_last_feedback);
x_recv = usecs_div(hcrx->ccid3hcrx_bytes_recv, delta);
if (x_recv == 0)
x_recv = hcrx->ccid3hcrx_x_recv;
tmp1 = (u64)x_recv * (u64)rtt;
do_div(tmp1,10000000);
tmp2 = (u32)tmp1;
if (!tmp2) {
DCCP_CRIT("tmp2 = 0, x_recv = %u, rtt =%u\n", x_recv, rtt);
return ~0;
}
fval = (hcrx->ccid3hcrx_s * 100000) / tmp2;
/* do not alter order above or you will get overflow on 32 bit */
p = tfrc_calc_x_reverse_lookup(fval);
ccid3_pr_debug("%s, sk=%p, receive rate=%u bytes/s, implied "
"loss rate=%u\n", dccp_role(sk), sk, x_recv, p);
if (p == 0)
return ~0;
else
return 1000000 / p;
}
static void ccid3_hc_rx_update_li(struct sock *sk, u64 seq_loss, u8 win_loss)
{
struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
struct dccp_li_hist_entry *head;
u64 seq_temp;
if (list_empty(&hcrx->ccid3hcrx_li_hist)) {
if (!dccp_li_hist_interval_new(ccid3_li_hist,
&hcrx->ccid3hcrx_li_hist, seq_loss, win_loss))
return;
head = list_entry(hcrx->ccid3hcrx_li_hist.next,
struct dccp_li_hist_entry, dccplih_node);
head->dccplih_interval = ccid3_hc_rx_calc_first_li(sk);
} else {
struct dccp_li_hist_entry *entry;
struct list_head *tail;
head = list_entry(hcrx->ccid3hcrx_li_hist.next,
struct dccp_li_hist_entry, dccplih_node);
/* FIXME win count check removed as was wrong */
/* should make this check with receive history */
/* and compare there as per section 10.2 of RFC4342 */
/* new loss event detected */
/* calculate last interval length */
seq_temp = dccp_delta_seqno(head->dccplih_seqno, seq_loss);
entry = dccp_li_hist_entry_new(ccid3_li_hist, SLAB_ATOMIC);
if (entry == NULL) {
DCCP_BUG("out of memory - can not allocate entry");
return;
}
list_add(&entry->dccplih_node, &hcrx->ccid3hcrx_li_hist);
tail = hcrx->ccid3hcrx_li_hist.prev;
list_del(tail);
kmem_cache_free(ccid3_li_hist->dccplih_slab, tail);
/* Create the newest interval */
entry->dccplih_seqno = seq_loss;
entry->dccplih_interval = seq_temp;
entry->dccplih_win_count = win_loss;
}
}
static int ccid3_hc_rx_detect_loss(struct sock *sk,
struct dccp_rx_hist_entry *packet)
{
struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
struct dccp_rx_hist_entry *rx_hist = dccp_rx_hist_head(&hcrx->ccid3hcrx_hist);
u64 seqno = packet->dccphrx_seqno;
u64 tmp_seqno;
int loss = 0;
u8 ccval;
tmp_seqno = hcrx->ccid3hcrx_seqno_nonloss;
if (!rx_hist ||
follows48(packet->dccphrx_seqno, hcrx->ccid3hcrx_seqno_nonloss)) {
hcrx->ccid3hcrx_seqno_nonloss = seqno;
hcrx->ccid3hcrx_ccval_nonloss = packet->dccphrx_ccval;
goto detect_out;
}
while (dccp_delta_seqno(hcrx->ccid3hcrx_seqno_nonloss, seqno)
> TFRC_RECV_NUM_LATE_LOSS) {
loss = 1;
ccid3_hc_rx_update_li(sk, hcrx->ccid3hcrx_seqno_nonloss,
hcrx->ccid3hcrx_ccval_nonloss);
tmp_seqno = hcrx->ccid3hcrx_seqno_nonloss;
dccp_inc_seqno(&tmp_seqno);
hcrx->ccid3hcrx_seqno_nonloss = tmp_seqno;
dccp_inc_seqno(&tmp_seqno);
while (dccp_rx_hist_find_entry(&hcrx->ccid3hcrx_hist,
tmp_seqno, &ccval)) {
hcrx->ccid3hcrx_seqno_nonloss = tmp_seqno;
hcrx->ccid3hcrx_ccval_nonloss = ccval;
dccp_inc_seqno(&tmp_seqno);
}
}
/* FIXME - this code could be simplified with above while */
/* but works at moment */
if (follows48(packet->dccphrx_seqno, hcrx->ccid3hcrx_seqno_nonloss)) {
hcrx->ccid3hcrx_seqno_nonloss = seqno;
hcrx->ccid3hcrx_ccval_nonloss = packet->dccphrx_ccval;
}
detect_out:
dccp_rx_hist_add_packet(ccid3_rx_hist, &hcrx->ccid3hcrx_hist,
&hcrx->ccid3hcrx_li_hist, packet,
hcrx->ccid3hcrx_seqno_nonloss);
return loss;
}
static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb)
{
struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
const struct dccp_options_received *opt_recv;
struct dccp_rx_hist_entry *packet;
struct timeval now;
u32 p_prev, rtt_prev, r_sample, t_elapsed;
int loss, payload_size;
BUG_ON(hcrx == NULL);
opt_recv = &dccp_sk(sk)->dccps_options_received;
switch (DCCP_SKB_CB(skb)->dccpd_type) {
case DCCP_PKT_ACK:
if (hcrx->ccid3hcrx_state == TFRC_RSTATE_NO_DATA)
return;
case DCCP_PKT_DATAACK:
if (opt_recv->dccpor_timestamp_echo == 0)
break;
rtt_prev = hcrx->ccid3hcrx_rtt;
dccp_timestamp(sk, &now);
timeval_sub_usecs(&now, opt_recv->dccpor_timestamp_echo * 10);
r_sample = timeval_usecs(&now);
t_elapsed = opt_recv->dccpor_elapsed_time * 10;
if (unlikely(r_sample <= t_elapsed))
DCCP_WARN("r_sample=%uus, t_elapsed=%uus\n",
r_sample, t_elapsed);
else
r_sample -= t_elapsed;
if (hcrx->ccid3hcrx_state == TFRC_RSTATE_NO_DATA)
hcrx->ccid3hcrx_rtt = r_sample;
else
hcrx->ccid3hcrx_rtt = (hcrx->ccid3hcrx_rtt * 9) / 10 +
r_sample / 10;
if (rtt_prev != hcrx->ccid3hcrx_rtt)
ccid3_pr_debug("%s, New RTT=%uus, elapsed time=%u\n",
dccp_role(sk), hcrx->ccid3hcrx_rtt,
opt_recv->dccpor_elapsed_time);
break;
case DCCP_PKT_DATA:
break;
default: /* We're not interested in other packet types, move along */
return;
}
packet = dccp_rx_hist_entry_new(ccid3_rx_hist, sk, opt_recv->dccpor_ndp,
skb, SLAB_ATOMIC);
if (unlikely(packet == NULL)) {
DCCP_WARN("%s, sk=%p, Not enough mem to add rx packet "
"to history, consider it lost!\n", dccp_role(sk), sk);
return;
}
loss = ccid3_hc_rx_detect_loss(sk, packet);
if (DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_ACK)
return;
payload_size = skb->len - dccp_hdr(skb)->dccph_doff * 4;
ccid3_hc_rx_update_s(hcrx, payload_size);
switch (hcrx->ccid3hcrx_state) {
case TFRC_RSTATE_NO_DATA:
ccid3_pr_debug("%s, sk=%p(%s), skb=%p, sending initial "
"feedback\n",
dccp_role(sk), sk,
dccp_state_name(sk->sk_state), skb);
ccid3_hc_rx_send_feedback(sk);
ccid3_hc_rx_set_state(sk, TFRC_RSTATE_DATA);
return;
case TFRC_RSTATE_DATA:
hcrx->ccid3hcrx_bytes_recv += payload_size;
if (loss)
break;
dccp_timestamp(sk, &now);
if (timeval_delta(&now, &hcrx->ccid3hcrx_tstamp_last_ack) >=
hcrx->ccid3hcrx_rtt) {
hcrx->ccid3hcrx_tstamp_last_ack = now;
ccid3_hc_rx_send_feedback(sk);
}
return;
case TFRC_RSTATE_TERM:
DCCP_BUG("Illegal %s state TERM, sk=%p", dccp_role(sk), sk);
return;
}
/* Dealing with packet loss */
ccid3_pr_debug("%s, sk=%p(%s), data loss! Reacting...\n",
dccp_role(sk), sk, dccp_state_name(sk->sk_state));
p_prev = hcrx->ccid3hcrx_p;
/* Calculate loss event rate */
if (!list_empty(&hcrx->ccid3hcrx_li_hist)) {
u32 i_mean = dccp_li_hist_calc_i_mean(&hcrx->ccid3hcrx_li_hist);
/* Scaling up by 1000000 as fixed decimal */
if (i_mean != 0)
hcrx->ccid3hcrx_p = 1000000 / i_mean;
} else
DCCP_BUG("empty loss history");
if (hcrx->ccid3hcrx_p > p_prev) {
ccid3_hc_rx_send_feedback(sk);
return;
}
}
static int ccid3_hc_rx_init(struct ccid *ccid, struct sock *sk)
{
struct ccid3_hc_rx_sock *hcrx = ccid_priv(ccid);
ccid3_pr_debug("%s, sk=%p\n", dccp_role(sk), 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_s = 0;
hcrx->ccid3hcrx_rtt = 5000; /* XXX 5ms for now... */
return 0;
}
static void ccid3_hc_rx_exit(struct sock *sk)
{
struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
BUG_ON(hcrx == NULL);
ccid3_hc_rx_set_state(sk, TFRC_RSTATE_TERM);
/* Empty packet history */
dccp_rx_hist_purge(ccid3_rx_hist, &hcrx->ccid3hcrx_hist);
/* Empty loss interval history */
dccp_li_hist_purge(ccid3_li_hist, &hcrx->ccid3hcrx_li_hist);
}
static void ccid3_hc_rx_get_info(struct sock *sk, struct tcp_info *info)
{
const struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
/* Listen socks doesn't have a private CCID block */
if (sk->sk_state == DCCP_LISTEN)
return;
BUG_ON(hcrx == NULL);
info->tcpi_ca_state = hcrx->ccid3hcrx_state;
info->tcpi_options |= TCPI_OPT_TIMESTAMPS;
info->tcpi_rcv_rtt = hcrx->ccid3hcrx_rtt;
}
static void ccid3_hc_tx_get_info(struct sock *sk, struct tcp_info *info)
{
const struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
/* Listen socks doesn't have a private CCID block */
if (sk->sk_state == DCCP_LISTEN)
return;
BUG_ON(hctx == NULL);
info->tcpi_rto = hctx->ccid3hctx_t_rto;
info->tcpi_rtt = hctx->ccid3hctx_rtt;
}
static 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 void *val;
/* Listen socks doesn't have a private CCID block */
if (sk->sk_state == DCCP_LISTEN)
return -EINVAL;
switch (optname) {
case DCCP_SOCKOPT_CCID_RX_INFO:
if (len < sizeof(hcrx->ccid3hcrx_tfrc))
return -EINVAL;
len = sizeof(hcrx->ccid3hcrx_tfrc);
val = &hcrx->ccid3hcrx_tfrc;
break;
default:
return -ENOPROTOOPT;
}
if (put_user(len, optlen) || copy_to_user(optval, val, len))
return -EFAULT;
return 0;
}
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 void *val;
/* Listen socks doesn't have a private CCID block */
if (sk->sk_state == DCCP_LISTEN)
return -EINVAL;
switch (optname) {
case DCCP_SOCKOPT_CCID_TX_INFO:
if (len < sizeof(hctx->ccid3hctx_tfrc))
return -EINVAL;
len = sizeof(hctx->ccid3hctx_tfrc);
val = &hctx->ccid3hctx_tfrc;
break;
default:
return -ENOPROTOOPT;
}
if (put_user(len, optlen) || copy_to_user(optval, val, len))
return -EFAULT;
return 0;
}
static struct ccid_operations ccid3 = {
.ccid_id = DCCPC_CCID3,
.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,
.ccid_hc_tx_packet_sent = ccid3_hc_tx_packet_sent,
.ccid_hc_tx_packet_recv = ccid3_hc_tx_packet_recv,
.ccid_hc_tx_insert_options = ccid3_hc_tx_insert_options,
.ccid_hc_tx_parse_options = ccid3_hc_tx_parse_options,
.ccid_hc_rx_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,
.ccid_hc_rx_packet_recv = ccid3_hc_rx_packet_recv,
.ccid_hc_rx_get_info = ccid3_hc_rx_get_info,
.ccid_hc_tx_get_info = ccid3_hc_tx_get_info,
.ccid_hc_rx_getsockopt = ccid3_hc_rx_getsockopt,
.ccid_hc_tx_getsockopt = ccid3_hc_tx_getsockopt,
};
#ifdef CONFIG_IP_DCCP_CCID3_DEBUG
module_param(ccid3_debug, int, 0444);
MODULE_PARM_DESC(ccid3_debug, "Enable debug messages");
#endif
static __init int ccid3_module_init(void)
{
int rc = -ENOBUFS;
ccid3_rx_hist = dccp_rx_hist_new("ccid3");
if (ccid3_rx_hist == NULL)
goto out;
ccid3_tx_hist = dccp_tx_hist_new("ccid3");
if (ccid3_tx_hist == NULL)
goto out_free_rx;
ccid3_li_hist = dccp_li_hist_new("ccid3");
if (ccid3_li_hist == NULL)
goto out_free_tx;
rc = ccid_register(&ccid3);
if (rc != 0)
goto out_free_loss_interval_history;
out:
return rc;
out_free_loss_interval_history:
dccp_li_hist_delete(ccid3_li_hist);
ccid3_li_hist = NULL;
out_free_tx:
dccp_tx_hist_delete(ccid3_tx_hist);
ccid3_tx_hist = NULL;
out_free_rx:
dccp_rx_hist_delete(ccid3_rx_hist);
ccid3_rx_hist = NULL;
goto out;
}
module_init(ccid3_module_init);
static __exit void ccid3_module_exit(void)
{
ccid_unregister(&ccid3);
if (ccid3_tx_hist != NULL) {
dccp_tx_hist_delete(ccid3_tx_hist);
ccid3_tx_hist = NULL;
}
if (ccid3_rx_hist != NULL) {
dccp_rx_hist_delete(ccid3_rx_hist);
ccid3_rx_hist = NULL;
}
if (ccid3_li_hist != NULL) {
dccp_li_hist_delete(ccid3_li_hist);
ccid3_li_hist = NULL;
}
}
module_exit(ccid3_module_exit);
MODULE_AUTHOR("Ian McDonald <ian.mcdonald@jandi.co.nz>, "
"Arnaldo Carvalho de Melo <acme@ghostprotocols.net>");
MODULE_DESCRIPTION("DCCP TFRC CCID3 CCID");
MODULE_LICENSE("GPL");
MODULE_ALIAS("net-dccp-ccid-3");
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