2 * net/dccp/ccids/ccid3.c
4 * Copyright (c) 2005 The University of Waikato, Hamilton, New Zealand.
5 * Copyright (c) 2005-6 Ian McDonald <ian.mcdonald@jandi.co.nz>
7 * An implementation of the DCCP protocol
9 * This code has been developed by the University of Waikato WAND
10 * research group. For further information please see http://www.wand.net.nz/
12 * This code also uses code from Lulea University, rereleased as GPL by its
14 * Copyright (c) 2003 Nils-Erik Mattsson, Joacim Haggmark, Magnus Erixzon
16 * Changes to meet Linux coding standards, to make it meet latest ccid3 draft
17 * and to make it work as a loadable module in the DCCP stack written by
18 * Arnaldo Carvalho de Melo <acme@conectiva.com.br>.
20 * Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br>
22 * This program is free software; you can redistribute it and/or modify
23 * it under the terms of the GNU General Public License as published by
24 * the Free Software Foundation; either version 2 of the License, or
25 * (at your option) any later version.
27 * This program is distributed in the hope that it will be useful,
28 * but WITHOUT ANY WARRANTY; without even the implied warranty of
29 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
30 * GNU General Public License for more details.
32 * You should have received a copy of the GNU General Public License
33 * along with this program; if not, write to the Free Software
34 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
39 #include "lib/packet_history.h"
40 #include "lib/loss_interval.h"
45 * Reason for maths here is to avoid 32 bit overflow when a is big.
46 * With this we get close to the limit.
48 static u32 usecs_div(const u32 a, const u32 b)
50 const u32 div = a < (UINT_MAX / (USEC_PER_SEC / 10)) ? 10 :
51 a < (UINT_MAX / (USEC_PER_SEC / 50)) ? 50 :
52 a < (UINT_MAX / (USEC_PER_SEC / 100)) ? 100 :
53 a < (UINT_MAX / (USEC_PER_SEC / 500)) ? 500 :
54 a < (UINT_MAX / (USEC_PER_SEC / 1000)) ? 1000 :
55 a < (UINT_MAX / (USEC_PER_SEC / 5000)) ? 5000 :
56 a < (UINT_MAX / (USEC_PER_SEC / 10000)) ? 10000 :
57 a < (UINT_MAX / (USEC_PER_SEC / 50000)) ? 50000 :
59 const u32 tmp = a * (USEC_PER_SEC / div);
60 return (b >= 2 * div) ? tmp / (b / div) : tmp;
65 #ifdef CONFIG_IP_DCCP_CCID3_DEBUG
66 static int ccid3_debug;
67 #define ccid3_pr_debug(format, a...) DCCP_PR_DEBUG(ccid3_debug, format, ##a)
69 #define ccid3_pr_debug(format, a...)
72 static struct dccp_tx_hist *ccid3_tx_hist;
73 static struct dccp_rx_hist *ccid3_rx_hist;
74 static struct dccp_li_hist *ccid3_li_hist;
76 #ifdef CONFIG_IP_DCCP_CCID3_DEBUG
77 static const char *ccid3_tx_state_name(enum ccid3_hc_tx_states state)
79 static char *ccid3_state_names[] = {
80 [TFRC_SSTATE_NO_SENT] = "NO_SENT",
81 [TFRC_SSTATE_NO_FBACK] = "NO_FBACK",
82 [TFRC_SSTATE_FBACK] = "FBACK",
83 [TFRC_SSTATE_TERM] = "TERM",
86 return ccid3_state_names[state];
90 static void ccid3_hc_tx_set_state(struct sock *sk,
91 enum ccid3_hc_tx_states state)
93 struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
94 enum ccid3_hc_tx_states oldstate = hctx->ccid3hctx_state;
96 ccid3_pr_debug("%s(%p) %-8.8s -> %s\n",
97 dccp_role(sk), sk, ccid3_tx_state_name(oldstate),
98 ccid3_tx_state_name(state));
99 WARN_ON(state == oldstate);
100 hctx->ccid3hctx_state = state;
104 * Recalculate scheduled nominal send time t_nom, inter-packet interval
105 * t_ipi, and delta value. Should be called after each change to X.
107 static inline void ccid3_update_send_time(struct ccid3_hc_tx_sock *hctx)
109 timeval_sub_usecs(&hctx->ccid3hctx_t_nom, hctx->ccid3hctx_t_ipi);
111 /* Calculate new t_ipi (inter packet interval) by t_ipi = s / X_inst */
112 hctx->ccid3hctx_t_ipi = usecs_div(hctx->ccid3hctx_s, hctx->ccid3hctx_x);
114 /* Update nominal send time with regard to the new t_ipi */
115 timeval_add_usecs(&hctx->ccid3hctx_t_nom, hctx->ccid3hctx_t_ipi);
117 /* Calculate new delta by delta = min(t_ipi / 2, t_gran / 2) */
118 hctx->ccid3hctx_delta = min_t(u32, hctx->ccid3hctx_t_ipi / 2,
119 TFRC_OPSYS_HALF_TIME_GRAN);
124 * X_calc = calcX(s, R, p);
125 * X = max(min(X_calc, 2 * X_recv), s / t_mbi);
127 * If (now - tld >= R)
128 * X = max(min(2 * X, 2 * X_recv), s / R);
131 * If X has changed, we also update the scheduled send time t_now,
132 * the inter-packet interval t_ipi, and the delta value.
134 static void ccid3_hc_tx_update_x(struct sock *sk, struct timeval *now)
137 struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
138 const __u32 old_x = hctx->ccid3hctx_x;
140 /* To avoid large error in calcX */
141 if (hctx->ccid3hctx_p >= TFRC_SMALLEST_P) {
142 hctx->ccid3hctx_x_calc = tfrc_calc_x(hctx->ccid3hctx_s,
145 hctx->ccid3hctx_x = max_t(u32, min(hctx->ccid3hctx_x_calc,
146 hctx->ccid3hctx_x_recv * 2),
147 hctx->ccid3hctx_s / TFRC_T_MBI);
149 } else if (timeval_delta(now, &hctx->ccid3hctx_t_ld) >=
150 hctx->ccid3hctx_rtt) {
151 hctx->ccid3hctx_x = max(min(hctx->ccid3hctx_x_recv,
152 hctx->ccid3hctx_x ) * 2,
153 usecs_div(hctx->ccid3hctx_s,
154 hctx->ccid3hctx_rtt) );
155 hctx->ccid3hctx_t_ld = *now;
157 ccid3_pr_debug("Not changing X\n");
159 if (hctx->ccid3hctx_x != old_x)
160 ccid3_update_send_time(hctx);
164 * Track the mean packet size `s' (cf. RFC 4342, 5.3 and RFC 3448, 4.1)
165 * @len: DCCP packet payload size in bytes
167 static inline void ccid3_hc_tx_update_s(struct ccid3_hc_tx_sock *hctx, int len)
169 if (unlikely(len == 0))
170 ccid3_pr_debug("Packet payload length is 0 - not updating\n");
172 hctx->ccid3hctx_s = hctx->ccid3hctx_s == 0 ? len :
173 (9 * hctx->ccid3hctx_s + len) / 10;
175 * Note: We could do a potential optimisation here - when `s' changes,
176 * recalculate sending rate and consequently t_ipi, t_delta, and
177 * t_now. This is however non-standard, and the benefits are not
178 * clear, so it is currently left out.
182 static void ccid3_hc_tx_no_feedback_timer(unsigned long data)
184 struct sock *sk = (struct sock *)data;
185 struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
186 unsigned long t_nfb = USEC_PER_SEC / 5;
189 if (sock_owned_by_user(sk)) {
190 /* Try again later. */
191 /* XXX: set some sensible MIB */
195 ccid3_pr_debug("%s, sk=%p, state=%s\n", dccp_role(sk), sk,
196 ccid3_tx_state_name(hctx->ccid3hctx_state));
198 switch (hctx->ccid3hctx_state) {
199 case TFRC_SSTATE_NO_FBACK:
200 /* RFC 3448, 4.4: Halve send rate directly */
201 hctx->ccid3hctx_x = min_t(u32, hctx->ccid3hctx_x / 2,
202 hctx->ccid3hctx_s / TFRC_T_MBI);
204 ccid3_pr_debug("%s, sk=%p, state=%s, updated tx rate to %d "
207 ccid3_tx_state_name(hctx->ccid3hctx_state),
209 /* The value of R is still undefined and so we can not recompute
210 * the timout value. Keep initial value as per [RFC 4342, 5]. */
211 t_nfb = TFRC_INITIAL_TIMEOUT;
212 ccid3_update_send_time(hctx);
214 case TFRC_SSTATE_FBACK:
216 * Check if IDLE since last timeout and recv rate is less than
219 if (!hctx->ccid3hctx_idle ||
220 (hctx->ccid3hctx_x_recv >=
221 4 * usecs_div(hctx->ccid3hctx_s, hctx->ccid3hctx_rtt))) {
224 ccid3_pr_debug("%s, sk=%p, state=%s, not idle\n",
226 ccid3_tx_state_name(hctx->ccid3hctx_state));
227 /* Halve sending rate */
229 /* If (X_calc > 2 * X_recv)
230 * X_recv = max(X_recv / 2, s / (2 * t_mbi));
232 * X_recv = X_calc / 4;
234 BUG_ON(hctx->ccid3hctx_p >= TFRC_SMALLEST_P &&
235 hctx->ccid3hctx_x_calc == 0);
237 /* check also if p is zero -> x_calc is infinity? */
238 if (hctx->ccid3hctx_p < TFRC_SMALLEST_P ||
239 hctx->ccid3hctx_x_calc > 2 * hctx->ccid3hctx_x_recv)
240 hctx->ccid3hctx_x_recv = max_t(u32, hctx->ccid3hctx_x_recv / 2,
241 hctx->ccid3hctx_s / (2 * TFRC_T_MBI));
243 hctx->ccid3hctx_x_recv = hctx->ccid3hctx_x_calc / 4;
245 /* Update sending rate */
246 dccp_timestamp(sk, &now);
247 ccid3_hc_tx_update_x(sk, &now);
250 * Schedule no feedback timer to expire in
251 * max(t_RTO, 2 * s/X) = max(t_RTO, 2 * t_ipi)
252 * See comments in packet_recv() regarding the value of t_RTO.
254 t_nfb = max(hctx->ccid3hctx_t_rto, 2 * hctx->ccid3hctx_t_ipi);
256 case TFRC_SSTATE_NO_SENT:
257 DCCP_BUG("Illegal %s state NO_SENT, sk=%p", dccp_role(sk), sk);
259 case TFRC_SSTATE_TERM:
263 hctx->ccid3hctx_idle = 1;
266 sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer,
267 jiffies + usecs_to_jiffies(t_nfb));
275 * > 0: delay (in msecs) that should pass before actually sending
276 * = 0: can send immediately
277 * < 0: error condition; do not send packet
279 static int ccid3_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb)
281 struct dccp_sock *dp = dccp_sk(sk);
282 struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
283 struct dccp_tx_hist_entry *new_packet;
287 BUG_ON(hctx == NULL);
290 * This function is called only for Data and DataAck packets. Sending
291 * zero-sized Data(Ack)s is theoretically possible, but for congestion
292 * control this case is pathological - ignore it.
294 if (unlikely(skb->len == 0))
297 /* See if last packet allocated was not sent */
298 new_packet = dccp_tx_hist_head(&hctx->ccid3hctx_hist);
299 if (new_packet == NULL || new_packet->dccphtx_sent) {
300 new_packet = dccp_tx_hist_entry_new(ccid3_tx_hist,
303 if (unlikely(new_packet == NULL)) {
304 DCCP_WARN("%s, sk=%p, not enough mem to add to history,"
305 "send refused\n", dccp_role(sk), sk);
309 dccp_tx_hist_add_entry(&hctx->ccid3hctx_hist, new_packet);
312 dccp_timestamp(sk, &now);
314 switch (hctx->ccid3hctx_state) {
315 case TFRC_SSTATE_NO_SENT:
316 sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer,
317 jiffies + usecs_to_jiffies(TFRC_INITIAL_TIMEOUT));
318 hctx->ccid3hctx_last_win_count = 0;
319 hctx->ccid3hctx_t_last_win_count = now;
320 ccid3_hc_tx_set_state(sk, TFRC_SSTATE_NO_FBACK);
322 /* Set initial sending rate to 1 packet per second */
323 ccid3_hc_tx_update_s(hctx, skb->len);
324 hctx->ccid3hctx_x = hctx->ccid3hctx_s;
326 /* First timeout, according to [RFC 3448, 4.2], is 1 second */
327 hctx->ccid3hctx_t_ipi = USEC_PER_SEC;
328 /* Initial delta: minimum of 0.5 sec and t_gran/2 */
329 hctx->ccid3hctx_delta = TFRC_OPSYS_HALF_TIME_GRAN;
331 /* Set t_0 for initial packet */
332 hctx->ccid3hctx_t_nom = now;
334 case TFRC_SSTATE_NO_FBACK:
335 case TFRC_SSTATE_FBACK:
336 delay = timeval_delta(&hctx->ccid3hctx_t_nom, &now);
338 * Scheduling of packet transmissions [RFC 3448, 4.6]
340 * if (t_now > t_nom - delta)
341 * // send the packet now
343 * // send the packet in (t_nom - t_now) milliseconds.
345 if (delay - (long)hctx->ccid3hctx_delta >= 0)
346 return delay / 1000L;
348 case TFRC_SSTATE_TERM:
349 DCCP_BUG("Illegal %s state TERM, sk=%p", dccp_role(sk), sk);
353 /* prepare to send now (add options etc.) */
354 dp->dccps_hc_tx_insert_options = 1;
355 new_packet->dccphtx_ccval = DCCP_SKB_CB(skb)->dccpd_ccval =
356 hctx->ccid3hctx_last_win_count;
357 timeval_add_usecs(&hctx->ccid3hctx_t_nom, hctx->ccid3hctx_t_ipi);
362 static void ccid3_hc_tx_packet_sent(struct sock *sk, int more, unsigned int len)
364 const struct dccp_sock *dp = dccp_sk(sk);
365 struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
367 unsigned long quarter_rtt;
368 struct dccp_tx_hist_entry *packet;
370 BUG_ON(hctx == NULL);
372 dccp_timestamp(sk, &now);
374 ccid3_hc_tx_update_s(hctx, len);
376 packet = dccp_tx_hist_head(&hctx->ccid3hctx_hist);
377 if (unlikely(packet == NULL)) {
378 DCCP_WARN("packet doesn't exist in history!\n");
381 if (unlikely(packet->dccphtx_sent)) {
382 DCCP_WARN("no unsent packet in history!\n");
385 packet->dccphtx_tstamp = now;
386 packet->dccphtx_seqno = dp->dccps_gss;
388 * Check if win_count have changed
389 * Algorithm in "8.1. Window Counter Value" in RFC 4342.
391 quarter_rtt = timeval_delta(&now, &hctx->ccid3hctx_t_last_win_count);
392 if (likely(hctx->ccid3hctx_rtt > 8))
393 quarter_rtt /= hctx->ccid3hctx_rtt / 4;
395 if (quarter_rtt > 0) {
396 hctx->ccid3hctx_t_last_win_count = now;
397 hctx->ccid3hctx_last_win_count = (hctx->ccid3hctx_last_win_count +
398 min_t(unsigned long, quarter_rtt, 5)) % 16;
399 ccid3_pr_debug("%s, sk=%p, window changed from "
402 packet->dccphtx_ccval,
403 hctx->ccid3hctx_last_win_count);
406 hctx->ccid3hctx_idle = 0;
407 packet->dccphtx_rtt = hctx->ccid3hctx_rtt;
408 packet->dccphtx_sent = 1;
411 static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb)
413 const struct dccp_sock *dp = dccp_sk(sk);
414 struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
415 struct ccid3_options_received *opt_recv;
416 struct dccp_tx_hist_entry *packet;
420 long r_sample, t_elapsed;
422 BUG_ON(hctx == NULL);
424 /* we are only interested in ACKs */
425 if (!(DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_ACK ||
426 DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_DATAACK))
429 opt_recv = &hctx->ccid3hctx_options_received;
431 switch (hctx->ccid3hctx_state) {
432 case TFRC_SSTATE_NO_FBACK:
433 case TFRC_SSTATE_FBACK:
434 /* get packet from history to look up t_recvdata */
435 packet = dccp_tx_hist_find_entry(&hctx->ccid3hctx_hist,
436 DCCP_SKB_CB(skb)->dccpd_ack_seq);
437 if (unlikely(packet == NULL)) {
438 DCCP_WARN("%s(%p), seqno %llu(%s) doesn't exist "
439 "in history!\n", dccp_role(sk), sk,
440 (unsigned long long)DCCP_SKB_CB(skb)->dccpd_ack_seq,
441 dccp_packet_name(DCCP_SKB_CB(skb)->dccpd_type));
445 /* Update receive rate */
446 hctx->ccid3hctx_x_recv = opt_recv->ccid3or_receive_rate;
448 /* Update loss event rate */
449 pinv = opt_recv->ccid3or_loss_event_rate;
450 if (pinv == ~0U || pinv == 0)
451 hctx->ccid3hctx_p = 0;
453 hctx->ccid3hctx_p = 1000000 / pinv;
455 if (hctx->ccid3hctx_p < TFRC_SMALLEST_P) {
456 hctx->ccid3hctx_p = TFRC_SMALLEST_P;
457 ccid3_pr_debug("%s, sk=%p, Smallest p used!\n",
462 dccp_timestamp(sk, &now);
465 * Calculate new round trip sample as per [RFC 3448, 4.3] by
466 * R_sample = (now - t_recvdata) - t_elapsed
468 r_sample = timeval_delta(&now, &packet->dccphtx_tstamp);
469 t_elapsed = dp->dccps_options_received.dccpor_elapsed_time * 10;
471 if (unlikely(r_sample <= 0)) {
472 DCCP_WARN("WARNING: R_sample (%ld) <= 0!\n", r_sample);
474 } else if (unlikely(r_sample <= t_elapsed))
475 DCCP_WARN("WARNING: r_sample=%ldus <= t_elapsed=%ldus\n",
476 r_sample, t_elapsed);
478 r_sample -= t_elapsed;
480 /* Update RTT estimate by
481 * If (No feedback recv)
484 * R = q * R + (1 - q) * R_sample;
486 * q is a constant, RFC 3448 recomments 0.9
488 if (hctx->ccid3hctx_state == TFRC_SSTATE_NO_FBACK) {
489 /* Use Larger Initial Windows [RFC 4342, sec. 5]
490 * We deviate in that we use `s' instead of `MSS'. */
491 u16 w_init = max( 4 * hctx->ccid3hctx_s,
492 max(2 * hctx->ccid3hctx_s, 4380));
493 hctx->ccid3hctx_rtt = r_sample;
494 hctx->ccid3hctx_x = usecs_div(w_init, r_sample);
495 hctx->ccid3hctx_t_ld = now;
497 ccid3_update_send_time(hctx);
499 ccid3_pr_debug("%s(%p), s=%u, w_init=%u, "
500 "R_sample=%ldus, X=%u\n", dccp_role(sk),
501 sk, hctx->ccid3hctx_s, w_init, r_sample,
504 ccid3_hc_tx_set_state(sk, TFRC_SSTATE_FBACK);
506 hctx->ccid3hctx_rtt = (9 * hctx->ccid3hctx_rtt +
507 (u32)r_sample ) / 10;
509 ccid3_hc_tx_update_x(sk, &now);
511 ccid3_pr_debug("%s(%p), RTT=%uus (sample=%ldus), s=%u, "
512 "p=%u, X_calc=%u, X=%u\n", dccp_role(sk),
513 sk, hctx->ccid3hctx_rtt, r_sample,
514 hctx->ccid3hctx_s, hctx->ccid3hctx_p,
515 hctx->ccid3hctx_x_calc,
519 /* unschedule no feedback timer */
520 sk_stop_timer(sk, &hctx->ccid3hctx_no_feedback_timer);
522 /* remove all packets older than the one acked from history */
523 dccp_tx_hist_purge_older(ccid3_tx_hist,
524 &hctx->ccid3hctx_hist, packet);
526 * As we have calculated new ipi, delta, t_nom it is possible that
527 * we now can send a packet, so wake up dccp_wait_for_ccid
529 sk->sk_write_space(sk);
532 * Update timeout interval for the nofeedback timer.
533 * We use a configuration option to increase the lower bound.
534 * This can help avoid triggering the nofeedback timer too often
535 * ('spinning') on LANs with small RTTs.
537 hctx->ccid3hctx_t_rto = max_t(u32, 4 * hctx->ccid3hctx_rtt,
538 CONFIG_IP_DCCP_CCID3_RTO *
539 (USEC_PER_SEC/1000) );
541 * Schedule no feedback timer to expire in
542 * max(t_RTO, 2 * s/X) = max(t_RTO, 2 * t_ipi)
544 t_nfb = max(hctx->ccid3hctx_t_rto, 2 * hctx->ccid3hctx_t_ipi);
546 ccid3_pr_debug("%s, sk=%p, Scheduled no feedback timer to "
547 "expire in %lu jiffies (%luus)\n",
549 usecs_to_jiffies(t_nfb), t_nfb);
551 sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer,
552 jiffies + usecs_to_jiffies(t_nfb));
555 hctx->ccid3hctx_idle = 1;
557 case TFRC_SSTATE_NO_SENT:
558 DCCP_WARN("Illegal ACK received - no packet has been sent\n");
560 case TFRC_SSTATE_TERM: /* ignore feedback when closing */
565 static int ccid3_hc_tx_insert_options(struct sock *sk, struct sk_buff *skb)
567 const struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
569 BUG_ON(hctx == NULL);
571 if (sk->sk_state == DCCP_OPEN || sk->sk_state == DCCP_PARTOPEN)
572 DCCP_SKB_CB(skb)->dccpd_ccval = hctx->ccid3hctx_last_win_count;
576 static int ccid3_hc_tx_parse_options(struct sock *sk, unsigned char option,
577 unsigned char len, u16 idx,
578 unsigned char *value)
581 const struct dccp_sock *dp = dccp_sk(sk);
582 struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
583 struct ccid3_options_received *opt_recv;
585 BUG_ON(hctx == NULL);
587 opt_recv = &hctx->ccid3hctx_options_received;
589 if (opt_recv->ccid3or_seqno != dp->dccps_gsr) {
590 opt_recv->ccid3or_seqno = dp->dccps_gsr;
591 opt_recv->ccid3or_loss_event_rate = ~0;
592 opt_recv->ccid3or_loss_intervals_idx = 0;
593 opt_recv->ccid3or_loss_intervals_len = 0;
594 opt_recv->ccid3or_receive_rate = 0;
598 case TFRC_OPT_LOSS_EVENT_RATE:
599 if (unlikely(len != 4)) {
600 DCCP_WARN("%s, sk=%p, invalid len %d "
601 "for TFRC_OPT_LOSS_EVENT_RATE\n",
602 dccp_role(sk), sk, len);
605 opt_recv->ccid3or_loss_event_rate = ntohl(*(__be32 *)value);
606 ccid3_pr_debug("%s, sk=%p, LOSS_EVENT_RATE=%u\n",
608 opt_recv->ccid3or_loss_event_rate);
611 case TFRC_OPT_LOSS_INTERVALS:
612 opt_recv->ccid3or_loss_intervals_idx = idx;
613 opt_recv->ccid3or_loss_intervals_len = len;
614 ccid3_pr_debug("%s, sk=%p, LOSS_INTERVALS=(%u, %u)\n",
616 opt_recv->ccid3or_loss_intervals_idx,
617 opt_recv->ccid3or_loss_intervals_len);
619 case TFRC_OPT_RECEIVE_RATE:
620 if (unlikely(len != 4)) {
621 DCCP_WARN("%s, sk=%p, invalid len %d "
622 "for TFRC_OPT_RECEIVE_RATE\n",
623 dccp_role(sk), sk, len);
626 opt_recv->ccid3or_receive_rate = ntohl(*(__be32 *)value);
627 ccid3_pr_debug("%s, sk=%p, RECEIVE_RATE=%u\n",
629 opt_recv->ccid3or_receive_rate);
637 static int ccid3_hc_tx_init(struct ccid *ccid, struct sock *sk)
639 struct ccid3_hc_tx_sock *hctx = ccid_priv(ccid);
641 hctx->ccid3hctx_s = 0;
642 hctx->ccid3hctx_state = TFRC_SSTATE_NO_SENT;
643 INIT_LIST_HEAD(&hctx->ccid3hctx_hist);
645 hctx->ccid3hctx_no_feedback_timer.function = ccid3_hc_tx_no_feedback_timer;
646 hctx->ccid3hctx_no_feedback_timer.data = (unsigned long)sk;
647 init_timer(&hctx->ccid3hctx_no_feedback_timer);
652 static void ccid3_hc_tx_exit(struct sock *sk)
654 struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
656 BUG_ON(hctx == NULL);
658 ccid3_hc_tx_set_state(sk, TFRC_SSTATE_TERM);
659 sk_stop_timer(sk, &hctx->ccid3hctx_no_feedback_timer);
661 /* Empty packet history */
662 dccp_tx_hist_purge(ccid3_tx_hist, &hctx->ccid3hctx_hist);
666 * RX Half Connection methods
669 #ifdef CONFIG_IP_DCCP_CCID3_DEBUG
670 static const char *ccid3_rx_state_name(enum ccid3_hc_rx_states state)
672 static char *ccid3_rx_state_names[] = {
673 [TFRC_RSTATE_NO_DATA] = "NO_DATA",
674 [TFRC_RSTATE_DATA] = "DATA",
675 [TFRC_RSTATE_TERM] = "TERM",
678 return ccid3_rx_state_names[state];
682 static void ccid3_hc_rx_set_state(struct sock *sk,
683 enum ccid3_hc_rx_states state)
685 struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
686 enum ccid3_hc_rx_states oldstate = hcrx->ccid3hcrx_state;
688 ccid3_pr_debug("%s(%p) %-8.8s -> %s\n",
689 dccp_role(sk), sk, ccid3_rx_state_name(oldstate),
690 ccid3_rx_state_name(state));
691 WARN_ON(state == oldstate);
692 hcrx->ccid3hcrx_state = state;
695 static inline void ccid3_hc_rx_update_s(struct ccid3_hc_rx_sock *hcrx, int len)
697 if (unlikely(len == 0)) /* don't update on empty packets (e.g. ACKs) */
698 ccid3_pr_debug("Packet payload length is 0 - not updating\n");
700 hcrx->ccid3hcrx_s = hcrx->ccid3hcrx_s == 0 ? len :
701 (9 * hcrx->ccid3hcrx_s + len) / 10;
704 static void ccid3_hc_rx_send_feedback(struct sock *sk)
706 struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
707 struct dccp_sock *dp = dccp_sk(sk);
708 struct dccp_rx_hist_entry *packet;
711 ccid3_pr_debug("%s, sk=%p\n", dccp_role(sk), sk);
713 dccp_timestamp(sk, &now);
715 switch (hcrx->ccid3hcrx_state) {
716 case TFRC_RSTATE_NO_DATA:
717 hcrx->ccid3hcrx_x_recv = 0;
719 case TFRC_RSTATE_DATA: {
720 const u32 delta = timeval_delta(&now,
721 &hcrx->ccid3hcrx_tstamp_last_feedback);
722 hcrx->ccid3hcrx_x_recv = usecs_div(hcrx->ccid3hcrx_bytes_recv,
726 case TFRC_RSTATE_TERM:
727 DCCP_BUG("Illegal %s state TERM, sk=%p", dccp_role(sk), sk);
731 packet = dccp_rx_hist_find_data_packet(&hcrx->ccid3hcrx_hist);
732 if (unlikely(packet == NULL)) {
733 DCCP_WARN("%s, sk=%p, no data packet in history!\n",
738 hcrx->ccid3hcrx_tstamp_last_feedback = now;
739 hcrx->ccid3hcrx_ccval_last_counter = packet->dccphrx_ccval;
740 hcrx->ccid3hcrx_bytes_recv = 0;
742 /* Convert to multiples of 10us */
743 hcrx->ccid3hcrx_elapsed_time =
744 timeval_delta(&now, &packet->dccphrx_tstamp) / 10;
745 if (hcrx->ccid3hcrx_p == 0)
746 hcrx->ccid3hcrx_pinv = ~0;
748 hcrx->ccid3hcrx_pinv = 1000000 / hcrx->ccid3hcrx_p;
749 dp->dccps_hc_rx_insert_options = 1;
753 static int ccid3_hc_rx_insert_options(struct sock *sk, struct sk_buff *skb)
755 const struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
758 BUG_ON(hcrx == NULL);
760 if (!(sk->sk_state == DCCP_OPEN || sk->sk_state == DCCP_PARTOPEN))
763 DCCP_SKB_CB(skb)->dccpd_ccval = hcrx->ccid3hcrx_ccval_last_counter;
765 if (dccp_packet_without_ack(skb))
768 x_recv = htonl(hcrx->ccid3hcrx_x_recv);
769 pinv = htonl(hcrx->ccid3hcrx_pinv);
771 if ((hcrx->ccid3hcrx_elapsed_time != 0 &&
772 dccp_insert_option_elapsed_time(sk, skb,
773 hcrx->ccid3hcrx_elapsed_time)) ||
774 dccp_insert_option_timestamp(sk, skb) ||
775 dccp_insert_option(sk, skb, TFRC_OPT_LOSS_EVENT_RATE,
776 &pinv, sizeof(pinv)) ||
777 dccp_insert_option(sk, skb, TFRC_OPT_RECEIVE_RATE,
778 &x_recv, sizeof(x_recv)))
784 /* calculate first loss interval
786 * returns estimated loss interval in usecs */
788 static u32 ccid3_hc_rx_calc_first_li(struct sock *sk)
790 struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
791 struct dccp_rx_hist_entry *entry, *next, *tail = NULL;
792 u32 rtt, delta, x_recv, fval, p, tmp2;
793 struct timeval tstamp = { 0, };
799 list_for_each_entry_safe(entry, next, &hcrx->ccid3hcrx_hist,
801 if (dccp_rx_hist_entry_data_packet(entry)) {
806 tstamp = entry->dccphrx_tstamp;
807 win_count = entry->dccphrx_ccval;
811 interval = win_count - entry->dccphrx_ccval;
813 interval += TFRC_WIN_COUNT_LIMIT;
821 if (unlikely(step == 0)) {
822 DCCP_WARN("%s, sk=%p, packet history has no data packets!\n",
827 if (unlikely(interval == 0)) {
828 DCCP_WARN("%s, sk=%p, Could not find a win_count interval > 0."
829 "Defaulting to 1\n", dccp_role(sk), sk);
834 DCCP_CRIT("tail is null\n");
837 rtt = timeval_delta(&tstamp, &tail->dccphrx_tstamp) * 4 / interval;
838 ccid3_pr_debug("%s, sk=%p, approximated RTT to %uus\n",
839 dccp_role(sk), sk, rtt);
842 DCCP_WARN("RTT==0, setting to 1\n");
846 dccp_timestamp(sk, &tstamp);
847 delta = timeval_delta(&tstamp, &hcrx->ccid3hcrx_tstamp_last_feedback);
848 x_recv = usecs_div(hcrx->ccid3hcrx_bytes_recv, delta);
851 x_recv = hcrx->ccid3hcrx_x_recv;
853 tmp1 = (u64)x_recv * (u64)rtt;
854 do_div(tmp1,10000000);
858 DCCP_CRIT("tmp2 = 0, x_recv = %u, rtt =%u\n", x_recv, rtt);
862 fval = (hcrx->ccid3hcrx_s * 100000) / tmp2;
863 /* do not alter order above or you will get overflow on 32 bit */
864 p = tfrc_calc_x_reverse_lookup(fval);
865 ccid3_pr_debug("%s, sk=%p, receive rate=%u bytes/s, implied "
866 "loss rate=%u\n", dccp_role(sk), sk, x_recv, p);
874 static void ccid3_hc_rx_update_li(struct sock *sk, u64 seq_loss, u8 win_loss)
876 struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
877 struct dccp_li_hist_entry *head;
880 if (list_empty(&hcrx->ccid3hcrx_li_hist)) {
881 if (!dccp_li_hist_interval_new(ccid3_li_hist,
882 &hcrx->ccid3hcrx_li_hist, seq_loss, win_loss))
885 head = list_entry(hcrx->ccid3hcrx_li_hist.next,
886 struct dccp_li_hist_entry, dccplih_node);
887 head->dccplih_interval = ccid3_hc_rx_calc_first_li(sk);
889 struct dccp_li_hist_entry *entry;
890 struct list_head *tail;
892 head = list_entry(hcrx->ccid3hcrx_li_hist.next,
893 struct dccp_li_hist_entry, dccplih_node);
894 /* FIXME win count check removed as was wrong */
895 /* should make this check with receive history */
896 /* and compare there as per section 10.2 of RFC4342 */
898 /* new loss event detected */
899 /* calculate last interval length */
900 seq_temp = dccp_delta_seqno(head->dccplih_seqno, seq_loss);
901 entry = dccp_li_hist_entry_new(ccid3_li_hist, SLAB_ATOMIC);
904 DCCP_BUG("out of memory - can not allocate entry");
908 list_add(&entry->dccplih_node, &hcrx->ccid3hcrx_li_hist);
910 tail = hcrx->ccid3hcrx_li_hist.prev;
912 kmem_cache_free(ccid3_li_hist->dccplih_slab, tail);
914 /* Create the newest interval */
915 entry->dccplih_seqno = seq_loss;
916 entry->dccplih_interval = seq_temp;
917 entry->dccplih_win_count = win_loss;
921 static int ccid3_hc_rx_detect_loss(struct sock *sk,
922 struct dccp_rx_hist_entry *packet)
924 struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
925 struct dccp_rx_hist_entry *rx_hist = dccp_rx_hist_head(&hcrx->ccid3hcrx_hist);
926 u64 seqno = packet->dccphrx_seqno;
932 tmp_seqno = hcrx->ccid3hcrx_seqno_nonloss;
935 follows48(packet->dccphrx_seqno, hcrx->ccid3hcrx_seqno_nonloss)) {
936 hcrx->ccid3hcrx_seqno_nonloss = seqno;
937 hcrx->ccid3hcrx_ccval_nonloss = packet->dccphrx_ccval;
942 while (dccp_delta_seqno(hcrx->ccid3hcrx_seqno_nonloss, seqno)
943 > TFRC_RECV_NUM_LATE_LOSS) {
945 ccid3_hc_rx_update_li(sk, hcrx->ccid3hcrx_seqno_nonloss,
946 hcrx->ccid3hcrx_ccval_nonloss);
947 tmp_seqno = hcrx->ccid3hcrx_seqno_nonloss;
948 dccp_inc_seqno(&tmp_seqno);
949 hcrx->ccid3hcrx_seqno_nonloss = tmp_seqno;
950 dccp_inc_seqno(&tmp_seqno);
951 while (dccp_rx_hist_find_entry(&hcrx->ccid3hcrx_hist,
952 tmp_seqno, &ccval)) {
953 hcrx->ccid3hcrx_seqno_nonloss = tmp_seqno;
954 hcrx->ccid3hcrx_ccval_nonloss = ccval;
955 dccp_inc_seqno(&tmp_seqno);
959 /* FIXME - this code could be simplified with above while */
960 /* but works at moment */
961 if (follows48(packet->dccphrx_seqno, hcrx->ccid3hcrx_seqno_nonloss)) {
962 hcrx->ccid3hcrx_seqno_nonloss = seqno;
963 hcrx->ccid3hcrx_ccval_nonloss = packet->dccphrx_ccval;
967 dccp_rx_hist_add_packet(ccid3_rx_hist, &hcrx->ccid3hcrx_hist,
968 &hcrx->ccid3hcrx_li_hist, packet,
969 hcrx->ccid3hcrx_seqno_nonloss);
973 static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb)
975 struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
976 const struct dccp_options_received *opt_recv;
977 struct dccp_rx_hist_entry *packet;
979 u32 p_prev, rtt_prev, r_sample, t_elapsed;
980 int loss, payload_size;
982 BUG_ON(hcrx == NULL);
984 opt_recv = &dccp_sk(sk)->dccps_options_received;
986 switch (DCCP_SKB_CB(skb)->dccpd_type) {
988 if (hcrx->ccid3hcrx_state == TFRC_RSTATE_NO_DATA)
990 case DCCP_PKT_DATAACK:
991 if (opt_recv->dccpor_timestamp_echo == 0)
993 rtt_prev = hcrx->ccid3hcrx_rtt;
994 dccp_timestamp(sk, &now);
995 timeval_sub_usecs(&now, opt_recv->dccpor_timestamp_echo * 10);
996 r_sample = timeval_usecs(&now);
997 t_elapsed = opt_recv->dccpor_elapsed_time * 10;
999 if (unlikely(r_sample <= t_elapsed))
1000 DCCP_WARN("r_sample=%uus, t_elapsed=%uus\n",
1001 r_sample, t_elapsed);
1003 r_sample -= t_elapsed;
1005 if (hcrx->ccid3hcrx_state == TFRC_RSTATE_NO_DATA)
1006 hcrx->ccid3hcrx_rtt = r_sample;
1008 hcrx->ccid3hcrx_rtt = (hcrx->ccid3hcrx_rtt * 9) / 10 +
1011 if (rtt_prev != hcrx->ccid3hcrx_rtt)
1012 ccid3_pr_debug("%s, New RTT=%uus, elapsed time=%u\n",
1013 dccp_role(sk), hcrx->ccid3hcrx_rtt,
1014 opt_recv->dccpor_elapsed_time);
1018 default: /* We're not interested in other packet types, move along */
1022 packet = dccp_rx_hist_entry_new(ccid3_rx_hist, sk, opt_recv->dccpor_ndp,
1024 if (unlikely(packet == NULL)) {
1025 DCCP_WARN("%s, sk=%p, Not enough mem to add rx packet "
1026 "to history, consider it lost!\n", dccp_role(sk), sk);
1030 loss = ccid3_hc_rx_detect_loss(sk, packet);
1032 if (DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_ACK)
1035 payload_size = skb->len - dccp_hdr(skb)->dccph_doff * 4;
1036 ccid3_hc_rx_update_s(hcrx, payload_size);
1038 switch (hcrx->ccid3hcrx_state) {
1039 case TFRC_RSTATE_NO_DATA:
1040 ccid3_pr_debug("%s, sk=%p(%s), skb=%p, sending initial "
1043 dccp_state_name(sk->sk_state), skb);
1044 ccid3_hc_rx_send_feedback(sk);
1045 ccid3_hc_rx_set_state(sk, TFRC_RSTATE_DATA);
1047 case TFRC_RSTATE_DATA:
1048 hcrx->ccid3hcrx_bytes_recv += payload_size;
1052 dccp_timestamp(sk, &now);
1053 if (timeval_delta(&now, &hcrx->ccid3hcrx_tstamp_last_ack) >=
1054 hcrx->ccid3hcrx_rtt) {
1055 hcrx->ccid3hcrx_tstamp_last_ack = now;
1056 ccid3_hc_rx_send_feedback(sk);
1059 case TFRC_RSTATE_TERM:
1060 DCCP_BUG("Illegal %s state TERM, sk=%p", dccp_role(sk), sk);
1064 /* Dealing with packet loss */
1065 ccid3_pr_debug("%s, sk=%p(%s), data loss! Reacting...\n",
1066 dccp_role(sk), sk, dccp_state_name(sk->sk_state));
1068 p_prev = hcrx->ccid3hcrx_p;
1070 /* Calculate loss event rate */
1071 if (!list_empty(&hcrx->ccid3hcrx_li_hist)) {
1072 u32 i_mean = dccp_li_hist_calc_i_mean(&hcrx->ccid3hcrx_li_hist);
1074 /* Scaling up by 1000000 as fixed decimal */
1076 hcrx->ccid3hcrx_p = 1000000 / i_mean;
1078 DCCP_BUG("empty loss history");
1080 if (hcrx->ccid3hcrx_p > p_prev) {
1081 ccid3_hc_rx_send_feedback(sk);
1086 static int ccid3_hc_rx_init(struct ccid *ccid, struct sock *sk)
1088 struct ccid3_hc_rx_sock *hcrx = ccid_priv(ccid);
1090 ccid3_pr_debug("%s, sk=%p\n", dccp_role(sk), sk);
1092 hcrx->ccid3hcrx_state = TFRC_RSTATE_NO_DATA;
1093 INIT_LIST_HEAD(&hcrx->ccid3hcrx_hist);
1094 INIT_LIST_HEAD(&hcrx->ccid3hcrx_li_hist);
1095 dccp_timestamp(sk, &hcrx->ccid3hcrx_tstamp_last_ack);
1096 hcrx->ccid3hcrx_tstamp_last_feedback = hcrx->ccid3hcrx_tstamp_last_ack;
1097 hcrx->ccid3hcrx_s = 0;
1098 hcrx->ccid3hcrx_rtt = 5000; /* XXX 5ms for now... */
1102 static void ccid3_hc_rx_exit(struct sock *sk)
1104 struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
1106 BUG_ON(hcrx == NULL);
1108 ccid3_hc_rx_set_state(sk, TFRC_RSTATE_TERM);
1110 /* Empty packet history */
1111 dccp_rx_hist_purge(ccid3_rx_hist, &hcrx->ccid3hcrx_hist);
1113 /* Empty loss interval history */
1114 dccp_li_hist_purge(ccid3_li_hist, &hcrx->ccid3hcrx_li_hist);
1117 static void ccid3_hc_rx_get_info(struct sock *sk, struct tcp_info *info)
1119 const struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
1121 /* Listen socks doesn't have a private CCID block */
1122 if (sk->sk_state == DCCP_LISTEN)
1125 BUG_ON(hcrx == NULL);
1127 info->tcpi_ca_state = hcrx->ccid3hcrx_state;
1128 info->tcpi_options |= TCPI_OPT_TIMESTAMPS;
1129 info->tcpi_rcv_rtt = hcrx->ccid3hcrx_rtt;
1132 static void ccid3_hc_tx_get_info(struct sock *sk, struct tcp_info *info)
1134 const struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
1136 /* Listen socks doesn't have a private CCID block */
1137 if (sk->sk_state == DCCP_LISTEN)
1140 BUG_ON(hctx == NULL);
1142 info->tcpi_rto = hctx->ccid3hctx_t_rto;
1143 info->tcpi_rtt = hctx->ccid3hctx_rtt;
1146 static int ccid3_hc_rx_getsockopt(struct sock *sk, const int optname, int len,
1147 u32 __user *optval, int __user *optlen)
1149 const struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
1152 /* Listen socks doesn't have a private CCID block */
1153 if (sk->sk_state == DCCP_LISTEN)
1157 case DCCP_SOCKOPT_CCID_RX_INFO:
1158 if (len < sizeof(hcrx->ccid3hcrx_tfrc))
1160 len = sizeof(hcrx->ccid3hcrx_tfrc);
1161 val = &hcrx->ccid3hcrx_tfrc;
1164 return -ENOPROTOOPT;
1167 if (put_user(len, optlen) || copy_to_user(optval, val, len))
1173 static int ccid3_hc_tx_getsockopt(struct sock *sk, const int optname, int len,
1174 u32 __user *optval, int __user *optlen)
1176 const struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
1179 /* Listen socks doesn't have a private CCID block */
1180 if (sk->sk_state == DCCP_LISTEN)
1184 case DCCP_SOCKOPT_CCID_TX_INFO:
1185 if (len < sizeof(hctx->ccid3hctx_tfrc))
1187 len = sizeof(hctx->ccid3hctx_tfrc);
1188 val = &hctx->ccid3hctx_tfrc;
1191 return -ENOPROTOOPT;
1194 if (put_user(len, optlen) || copy_to_user(optval, val, len))
1200 static struct ccid_operations ccid3 = {
1201 .ccid_id = DCCPC_CCID3,
1202 .ccid_name = "ccid3",
1203 .ccid_owner = THIS_MODULE,
1204 .ccid_hc_tx_obj_size = sizeof(struct ccid3_hc_tx_sock),
1205 .ccid_hc_tx_init = ccid3_hc_tx_init,
1206 .ccid_hc_tx_exit = ccid3_hc_tx_exit,
1207 .ccid_hc_tx_send_packet = ccid3_hc_tx_send_packet,
1208 .ccid_hc_tx_packet_sent = ccid3_hc_tx_packet_sent,
1209 .ccid_hc_tx_packet_recv = ccid3_hc_tx_packet_recv,
1210 .ccid_hc_tx_insert_options = ccid3_hc_tx_insert_options,
1211 .ccid_hc_tx_parse_options = ccid3_hc_tx_parse_options,
1212 .ccid_hc_rx_obj_size = sizeof(struct ccid3_hc_rx_sock),
1213 .ccid_hc_rx_init = ccid3_hc_rx_init,
1214 .ccid_hc_rx_exit = ccid3_hc_rx_exit,
1215 .ccid_hc_rx_insert_options = ccid3_hc_rx_insert_options,
1216 .ccid_hc_rx_packet_recv = ccid3_hc_rx_packet_recv,
1217 .ccid_hc_rx_get_info = ccid3_hc_rx_get_info,
1218 .ccid_hc_tx_get_info = ccid3_hc_tx_get_info,
1219 .ccid_hc_rx_getsockopt = ccid3_hc_rx_getsockopt,
1220 .ccid_hc_tx_getsockopt = ccid3_hc_tx_getsockopt,
1223 #ifdef CONFIG_IP_DCCP_CCID3_DEBUG
1224 module_param(ccid3_debug, int, 0444);
1225 MODULE_PARM_DESC(ccid3_debug, "Enable debug messages");
1228 static __init int ccid3_module_init(void)
1232 ccid3_rx_hist = dccp_rx_hist_new("ccid3");
1233 if (ccid3_rx_hist == NULL)
1236 ccid3_tx_hist = dccp_tx_hist_new("ccid3");
1237 if (ccid3_tx_hist == NULL)
1240 ccid3_li_hist = dccp_li_hist_new("ccid3");
1241 if (ccid3_li_hist == NULL)
1244 rc = ccid_register(&ccid3);
1246 goto out_free_loss_interval_history;
1250 out_free_loss_interval_history:
1251 dccp_li_hist_delete(ccid3_li_hist);
1252 ccid3_li_hist = NULL;
1254 dccp_tx_hist_delete(ccid3_tx_hist);
1255 ccid3_tx_hist = NULL;
1257 dccp_rx_hist_delete(ccid3_rx_hist);
1258 ccid3_rx_hist = NULL;
1261 module_init(ccid3_module_init);
1263 static __exit void ccid3_module_exit(void)
1265 ccid_unregister(&ccid3);
1267 if (ccid3_tx_hist != NULL) {
1268 dccp_tx_hist_delete(ccid3_tx_hist);
1269 ccid3_tx_hist = NULL;
1271 if (ccid3_rx_hist != NULL) {
1272 dccp_rx_hist_delete(ccid3_rx_hist);
1273 ccid3_rx_hist = NULL;
1275 if (ccid3_li_hist != NULL) {
1276 dccp_li_hist_delete(ccid3_li_hist);
1277 ccid3_li_hist = NULL;
1280 module_exit(ccid3_module_exit);
1282 MODULE_AUTHOR("Ian McDonald <ian.mcdonald@jandi.co.nz>, "
1283 "Arnaldo Carvalho de Melo <acme@ghostprotocols.net>");
1284 MODULE_DESCRIPTION("DCCP TFRC CCID3 CCID");
1285 MODULE_LICENSE("GPL");
1286 MODULE_ALIAS("net-dccp-ccid-3");