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"
44 #ifdef CONFIG_IP_DCCP_CCID3_DEBUG
45 static int ccid3_debug;
46 #define ccid3_pr_debug(format, a...) DCCP_PR_DEBUG(ccid3_debug, format, ##a)
48 #define ccid3_pr_debug(format, a...)
51 static struct dccp_tx_hist *ccid3_tx_hist;
52 static struct dccp_rx_hist *ccid3_rx_hist;
53 static struct dccp_li_hist *ccid3_li_hist;
55 #ifdef CONFIG_IP_DCCP_CCID3_DEBUG
56 static const char *ccid3_tx_state_name(enum ccid3_hc_tx_states state)
58 static char *ccid3_state_names[] = {
59 [TFRC_SSTATE_NO_SENT] = "NO_SENT",
60 [TFRC_SSTATE_NO_FBACK] = "NO_FBACK",
61 [TFRC_SSTATE_FBACK] = "FBACK",
62 [TFRC_SSTATE_TERM] = "TERM",
65 return ccid3_state_names[state];
69 static void ccid3_hc_tx_set_state(struct sock *sk,
70 enum ccid3_hc_tx_states state)
72 struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
73 enum ccid3_hc_tx_states oldstate = hctx->ccid3hctx_state;
75 ccid3_pr_debug("%s(%p) %-8.8s -> %s\n",
76 dccp_role(sk), sk, ccid3_tx_state_name(oldstate),
77 ccid3_tx_state_name(state));
78 WARN_ON(state == oldstate);
79 hctx->ccid3hctx_state = state;
83 * Recalculate scheduled nominal send time t_nom, inter-packet interval
84 * t_ipi, and delta value. Should be called after each change to X.
86 static inline void ccid3_update_send_time(struct ccid3_hc_tx_sock *hctx)
88 timeval_sub_usecs(&hctx->ccid3hctx_t_nom, hctx->ccid3hctx_t_ipi);
90 /* Calculate new t_ipi = s / X_inst (X_inst is in 64 * bytes/second) */
91 hctx->ccid3hctx_t_ipi = scaled_div(hctx->ccid3hctx_s,
92 hctx->ccid3hctx_x >> 6);
94 /* Update nominal send time with regard to the new t_ipi */
95 timeval_add_usecs(&hctx->ccid3hctx_t_nom, hctx->ccid3hctx_t_ipi);
97 /* Calculate new delta by delta = min(t_ipi / 2, t_gran / 2) */
98 hctx->ccid3hctx_delta = min_t(u32, hctx->ccid3hctx_t_ipi / 2,
99 TFRC_OPSYS_HALF_TIME_GRAN);
104 * X_calc = calcX(s, R, p);
105 * X = max(min(X_calc, 2 * X_recv), s / t_mbi);
107 * If (now - tld >= R)
108 * X = max(min(2 * X, 2 * X_recv), s / R);
111 * Note: X and X_recv are both stored in units of 64 * bytes/second, to support
112 * fine-grained resolution of sending rates. This requires scaling by 2^6
113 * throughout the code. Only X_calc is unscaled (in bytes/second).
115 * If X has changed, we also update the scheduled send time t_now,
116 * the inter-packet interval t_ipi, and the delta value.
118 static void ccid3_hc_tx_update_x(struct sock *sk, struct timeval *now)
121 struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
122 const __u64 old_x = hctx->ccid3hctx_x;
124 if (hctx->ccid3hctx_p > 0) {
126 hctx->ccid3hctx_x = min(((__u64)hctx->ccid3hctx_x_calc) << 6,
127 hctx->ccid3hctx_x_recv * 2);
128 hctx->ccid3hctx_x = max(hctx->ccid3hctx_x,
129 (((__u64)hctx->ccid3hctx_s) << 6) /
132 } else if (timeval_delta(now, &hctx->ccid3hctx_t_ld) -
133 (suseconds_t)hctx->ccid3hctx_rtt >= 0) {
136 max(2 * min(hctx->ccid3hctx_x, hctx->ccid3hctx_x_recv),
137 scaled_div(((__u64)hctx->ccid3hctx_s) << 6,
138 hctx->ccid3hctx_rtt));
139 hctx->ccid3hctx_t_ld = *now;
142 if (hctx->ccid3hctx_x != old_x)
143 ccid3_update_send_time(hctx);
147 * Track the mean packet size `s' (cf. RFC 4342, 5.3 and RFC 3448, 4.1)
148 * @len: DCCP packet payload size in bytes
150 static inline void ccid3_hc_tx_update_s(struct ccid3_hc_tx_sock *hctx, int len)
152 hctx->ccid3hctx_s = hctx->ccid3hctx_s == 0 ? len :
153 (9 * hctx->ccid3hctx_s + len) / 10;
155 * Note: We could do a potential optimisation here - when `s' changes,
156 * recalculate sending rate and consequently t_ipi, t_delta, and
157 * t_now. This is however non-standard, and the benefits are not
158 * clear, so it is currently left out.
163 * Update Window Counter using the algorithm from [RFC 4342, 8.1].
164 * The algorithm is not applicable if RTT < 4 microseconds.
166 static inline void ccid3_hc_tx_update_win_count(struct ccid3_hc_tx_sock *hctx,
172 if (unlikely(hctx->ccid3hctx_rtt < 4)) /* avoid divide-by-zero */
175 delta = timeval_delta(now, &hctx->ccid3hctx_t_last_win_count);
176 DCCP_BUG_ON(delta < 0);
178 quarter_rtts = (u32)delta / (hctx->ccid3hctx_rtt / 4);
180 if (quarter_rtts > 0) {
181 hctx->ccid3hctx_t_last_win_count = *now;
182 hctx->ccid3hctx_last_win_count += min_t(u32, quarter_rtts, 5);
183 hctx->ccid3hctx_last_win_count &= 0xF; /* mod 16 */
185 ccid3_pr_debug("now at %#X\n", hctx->ccid3hctx_last_win_count);
189 static void ccid3_hc_tx_no_feedback_timer(unsigned long data)
191 struct sock *sk = (struct sock *)data;
192 struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
193 unsigned long t_nfb = USEC_PER_SEC / 5;
196 if (sock_owned_by_user(sk)) {
197 /* Try again later. */
198 /* XXX: set some sensible MIB */
202 ccid3_pr_debug("%s(%p, state=%s) - entry \n", dccp_role(sk), sk,
203 ccid3_tx_state_name(hctx->ccid3hctx_state));
205 switch (hctx->ccid3hctx_state) {
206 case TFRC_SSTATE_NO_FBACK:
207 /* RFC 3448, 4.4: Halve send rate directly */
208 hctx->ccid3hctx_x = max(hctx->ccid3hctx_x / 2,
209 (((__u64)hctx->ccid3hctx_s) << 6) /
212 ccid3_pr_debug("%s(%p, state=%s), updated tx rate to %u "
213 "bytes/s\n", dccp_role(sk), sk,
214 ccid3_tx_state_name(hctx->ccid3hctx_state),
215 (unsigned)(hctx->ccid3hctx_x >> 6));
216 /* The value of R is still undefined and so we can not recompute
217 * the timout value. Keep initial value as per [RFC 4342, 5]. */
218 t_nfb = TFRC_INITIAL_TIMEOUT;
219 ccid3_update_send_time(hctx);
221 case TFRC_SSTATE_FBACK:
223 * Check if IDLE since last timeout and recv rate is less than
224 * 4 packets (in units of 64*bytes/sec) per RTT
226 if (!hctx->ccid3hctx_idle ||
227 (hctx->ccid3hctx_x_recv >= 4 *
228 scaled_div(((__u64)hctx->ccid3hctx_s) << 6,
229 hctx->ccid3hctx_rtt))) {
232 ccid3_pr_debug("%s(%p, state=%s), not idle\n",
234 ccid3_tx_state_name(hctx->ccid3hctx_state));
237 * Modify the cached value of X_recv [RFC 3448, 4.4]
239 * If (p == 0 || X_calc > 2 * X_recv)
240 * X_recv = max(X_recv / 2, s / (2 * t_mbi));
242 * X_recv = X_calc / 4;
244 * Note that X_recv is scaled by 2^6 while X_calc is not
246 BUG_ON(hctx->ccid3hctx_p && !hctx->ccid3hctx_x_calc);
248 if (hctx->ccid3hctx_p == 0 ||
249 (hctx->ccid3hctx_x_calc >
250 (hctx->ccid3hctx_x_recv >> 5))) {
252 hctx->ccid3hctx_x_recv =
253 max(hctx->ccid3hctx_x_recv / 2,
254 (((__u64)hctx->ccid3hctx_s) << 6) /
257 if (hctx->ccid3hctx_p == 0)
258 dccp_timestamp(sk, &now);
260 hctx->ccid3hctx_x_recv = hctx->ccid3hctx_x_calc;
261 hctx->ccid3hctx_x_recv <<= 4;
263 /* Now recalculate X [RFC 3448, 4.3, step (4)] */
264 ccid3_hc_tx_update_x(sk, &now);
267 * Schedule no feedback timer to expire in
268 * max(t_RTO, 2 * s/X) = max(t_RTO, 2 * t_ipi)
269 * See comments in packet_recv() regarding the value of t_RTO.
271 t_nfb = max(hctx->ccid3hctx_t_rto, 2 * hctx->ccid3hctx_t_ipi);
273 case TFRC_SSTATE_NO_SENT:
274 DCCP_BUG("%s(%p) - Illegal state NO_SENT", dccp_role(sk), sk);
276 case TFRC_SSTATE_TERM:
280 hctx->ccid3hctx_idle = 1;
283 sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer,
284 jiffies + usecs_to_jiffies(t_nfb));
292 * > 0: delay (in msecs) that should pass before actually sending
293 * = 0: can send immediately
294 * < 0: error condition; do not send packet
296 static int ccid3_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb)
298 struct dccp_sock *dp = dccp_sk(sk);
299 struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
303 BUG_ON(hctx == NULL);
306 * This function is called only for Data and DataAck packets. Sending
307 * zero-sized Data(Ack)s is theoretically possible, but for congestion
308 * control this case is pathological - ignore it.
310 if (unlikely(skb->len == 0))
313 dccp_timestamp(sk, &now);
315 switch (hctx->ccid3hctx_state) {
316 case TFRC_SSTATE_NO_SENT:
317 sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer,
319 usecs_to_jiffies(TFRC_INITIAL_TIMEOUT)));
320 hctx->ccid3hctx_last_win_count = 0;
321 hctx->ccid3hctx_t_last_win_count = now;
322 ccid3_hc_tx_set_state(sk, TFRC_SSTATE_NO_FBACK);
324 /* Set initial sending rate X/s to 1pps (X is scaled by 2^6) */
325 ccid3_hc_tx_update_s(hctx, skb->len);
326 hctx->ccid3hctx_x = hctx->ccid3hctx_s;
327 hctx->ccid3hctx_x <<= 6;
329 /* First timeout, according to [RFC 3448, 4.2], is 1 second */
330 hctx->ccid3hctx_t_ipi = USEC_PER_SEC;
331 /* Initial delta: minimum of 0.5 sec and t_gran/2 */
332 hctx->ccid3hctx_delta = TFRC_OPSYS_HALF_TIME_GRAN;
334 /* Set t_0 for initial packet */
335 hctx->ccid3hctx_t_nom = now;
337 case TFRC_SSTATE_NO_FBACK:
338 case TFRC_SSTATE_FBACK:
339 delay = timeval_delta(&hctx->ccid3hctx_t_nom, &now);
341 * Scheduling of packet transmissions [RFC 3448, 4.6]
343 * if (t_now > t_nom - delta)
344 * // send the packet now
346 * // send the packet in (t_nom - t_now) milliseconds.
348 if (delay - (suseconds_t)hctx->ccid3hctx_delta >= 0)
349 return delay / 1000L;
351 ccid3_hc_tx_update_win_count(hctx, &now);
353 case TFRC_SSTATE_TERM:
354 DCCP_BUG("%s(%p) - Illegal state TERM", dccp_role(sk), sk);
358 /* prepare to send now (add options etc.) */
359 dp->dccps_hc_tx_insert_options = 1;
360 DCCP_SKB_CB(skb)->dccpd_ccval = hctx->ccid3hctx_last_win_count;
362 /* set the nominal send time for the next following packet */
363 timeval_add_usecs(&hctx->ccid3hctx_t_nom, hctx->ccid3hctx_t_ipi);
368 static void ccid3_hc_tx_packet_sent(struct sock *sk, int more,
371 struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
373 struct dccp_tx_hist_entry *packet;
375 BUG_ON(hctx == NULL);
377 ccid3_hc_tx_update_s(hctx, len);
379 packet = dccp_tx_hist_entry_new(ccid3_tx_hist, GFP_ATOMIC);
380 if (unlikely(packet == NULL)) {
381 DCCP_CRIT("packet history - out of memory!");
384 dccp_tx_hist_add_entry(&hctx->ccid3hctx_hist, packet);
386 dccp_timestamp(sk, &now);
387 packet->dccphtx_tstamp = now;
388 packet->dccphtx_seqno = dccp_sk(sk)->dccps_gss;
389 packet->dccphtx_rtt = hctx->ccid3hctx_rtt;
390 packet->dccphtx_sent = 1;
391 hctx->ccid3hctx_idle = 0;
394 static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb)
396 const struct dccp_sock *dp = dccp_sk(sk);
397 struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
398 struct ccid3_options_received *opt_recv;
399 struct dccp_tx_hist_entry *packet;
403 suseconds_t r_sample, t_elapsed;
405 BUG_ON(hctx == NULL);
407 /* we are only interested in ACKs */
408 if (!(DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_ACK ||
409 DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_DATAACK))
412 opt_recv = &hctx->ccid3hctx_options_received;
414 switch (hctx->ccid3hctx_state) {
415 case TFRC_SSTATE_NO_FBACK:
416 case TFRC_SSTATE_FBACK:
417 /* get packet from history to look up t_recvdata */
418 packet = dccp_tx_hist_find_entry(&hctx->ccid3hctx_hist,
419 DCCP_SKB_CB(skb)->dccpd_ack_seq);
420 if (unlikely(packet == NULL)) {
421 DCCP_WARN("%s(%p), seqno %llu(%s) doesn't exist "
422 "in history!\n", dccp_role(sk), sk,
423 (unsigned long long)DCCP_SKB_CB(skb)->dccpd_ack_seq,
424 dccp_packet_name(DCCP_SKB_CB(skb)->dccpd_type));
428 /* Update receive rate in units of 64 * bytes/second */
429 hctx->ccid3hctx_x_recv = opt_recv->ccid3or_receive_rate;
430 hctx->ccid3hctx_x_recv <<= 6;
432 /* Update loss event rate */
433 pinv = opt_recv->ccid3or_loss_event_rate;
434 if (pinv == ~0U || pinv == 0) /* see RFC 4342, 8.5 */
435 hctx->ccid3hctx_p = 0;
436 else /* can not exceed 100% */
437 hctx->ccid3hctx_p = 1000000 / pinv;
439 dccp_timestamp(sk, &now);
442 * Calculate new round trip sample as per [RFC 3448, 4.3] by
443 * R_sample = (now - t_recvdata) - t_elapsed
445 r_sample = timeval_delta(&now, &packet->dccphtx_tstamp);
446 t_elapsed = dp->dccps_options_received.dccpor_elapsed_time * 10;
448 DCCP_BUG_ON(r_sample < 0);
449 if (unlikely(r_sample <= t_elapsed))
450 DCCP_WARN("WARNING: r_sample=%dus <= t_elapsed=%dus\n",
451 (int)r_sample, (int)t_elapsed);
453 r_sample -= t_elapsed;
454 CCID3_RTT_SANITY_CHECK(r_sample);
456 /* Update RTT estimate by
457 * If (No feedback recv)
460 * R = q * R + (1 - q) * R_sample;
462 * q is a constant, RFC 3448 recomments 0.9
464 if (hctx->ccid3hctx_state == TFRC_SSTATE_NO_FBACK) {
466 * Larger Initial Windows [RFC 4342, sec. 5]
467 * We deviate in that we use `s' instead of `MSS'.
469 __u64 w_init = min(4 * hctx->ccid3hctx_s,
470 max(2 * hctx->ccid3hctx_s, 4380));
471 hctx->ccid3hctx_rtt = r_sample;
472 hctx->ccid3hctx_x = scaled_div(w_init << 6, r_sample);
473 hctx->ccid3hctx_t_ld = now;
475 ccid3_update_send_time(hctx);
477 ccid3_pr_debug("%s(%p), s=%u, w_init=%llu, "
478 "R_sample=%dus, X=%u\n", dccp_role(sk),
479 sk, hctx->ccid3hctx_s,
480 (unsigned long long)w_init,
482 (unsigned)(hctx->ccid3hctx_x >> 6));
484 ccid3_hc_tx_set_state(sk, TFRC_SSTATE_FBACK);
486 hctx->ccid3hctx_rtt = (9 * hctx->ccid3hctx_rtt +
489 /* Update sending rate (step 4 of [RFC 3448, 4.3]) */
490 if (hctx->ccid3hctx_p > 0)
491 hctx->ccid3hctx_x_calc =
492 tfrc_calc_x(hctx->ccid3hctx_s,
495 ccid3_hc_tx_update_x(sk, &now);
497 ccid3_pr_debug("%s(%p), RTT=%uus (sample=%dus), s=%u, "
498 "p=%u, X_calc=%u, X_recv=%u, X=%u\n",
500 sk, hctx->ccid3hctx_rtt, (int)r_sample,
501 hctx->ccid3hctx_s, hctx->ccid3hctx_p,
502 hctx->ccid3hctx_x_calc,
503 (unsigned)(hctx->ccid3hctx_x_recv >> 6),
504 (unsigned)(hctx->ccid3hctx_x >> 6));
507 /* unschedule no feedback timer */
508 sk_stop_timer(sk, &hctx->ccid3hctx_no_feedback_timer);
510 /* remove all packets older than the one acked from history */
511 dccp_tx_hist_purge_older(ccid3_tx_hist,
512 &hctx->ccid3hctx_hist, packet);
514 * As we have calculated new ipi, delta, t_nom it is possible
515 * that we now can send a packet, so wake up dccp_wait_for_ccid
517 sk->sk_write_space(sk);
520 * Update timeout interval for the nofeedback timer.
521 * We use a configuration option to increase the lower bound.
522 * This can help avoid triggering the nofeedback timer too
523 * often ('spinning') on LANs with small RTTs.
525 hctx->ccid3hctx_t_rto = max_t(u32, 4 * hctx->ccid3hctx_rtt,
526 CONFIG_IP_DCCP_CCID3_RTO *
527 (USEC_PER_SEC/1000));
529 * Schedule no feedback timer to expire in
530 * max(t_RTO, 2 * s/X) = max(t_RTO, 2 * t_ipi)
532 t_nfb = max(hctx->ccid3hctx_t_rto, 2 * hctx->ccid3hctx_t_ipi);
534 ccid3_pr_debug("%s(%p), Scheduled no feedback timer to "
535 "expire in %lu jiffies (%luus)\n",
537 sk, usecs_to_jiffies(t_nfb), t_nfb);
539 sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer,
540 jiffies + usecs_to_jiffies(t_nfb));
543 hctx->ccid3hctx_idle = 1;
545 case TFRC_SSTATE_NO_SENT: /* fall through */
546 case TFRC_SSTATE_TERM: /* ignore feedback when closing */
551 static int ccid3_hc_tx_parse_options(struct sock *sk, unsigned char option,
552 unsigned char len, u16 idx,
553 unsigned char *value)
556 const struct dccp_sock *dp = dccp_sk(sk);
557 struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
558 struct ccid3_options_received *opt_recv;
560 BUG_ON(hctx == NULL);
562 opt_recv = &hctx->ccid3hctx_options_received;
564 if (opt_recv->ccid3or_seqno != dp->dccps_gsr) {
565 opt_recv->ccid3or_seqno = dp->dccps_gsr;
566 opt_recv->ccid3or_loss_event_rate = ~0;
567 opt_recv->ccid3or_loss_intervals_idx = 0;
568 opt_recv->ccid3or_loss_intervals_len = 0;
569 opt_recv->ccid3or_receive_rate = 0;
573 case TFRC_OPT_LOSS_EVENT_RATE:
574 if (unlikely(len != 4)) {
575 DCCP_WARN("%s(%p), invalid len %d "
576 "for TFRC_OPT_LOSS_EVENT_RATE\n",
577 dccp_role(sk), sk, len);
580 opt_recv->ccid3or_loss_event_rate =
581 ntohl(*(__be32 *)value);
582 ccid3_pr_debug("%s(%p), LOSS_EVENT_RATE=%u\n",
584 opt_recv->ccid3or_loss_event_rate);
587 case TFRC_OPT_LOSS_INTERVALS:
588 opt_recv->ccid3or_loss_intervals_idx = idx;
589 opt_recv->ccid3or_loss_intervals_len = len;
590 ccid3_pr_debug("%s(%p), LOSS_INTERVALS=(%u, %u)\n",
592 opt_recv->ccid3or_loss_intervals_idx,
593 opt_recv->ccid3or_loss_intervals_len);
595 case TFRC_OPT_RECEIVE_RATE:
596 if (unlikely(len != 4)) {
597 DCCP_WARN("%s(%p), invalid len %d "
598 "for TFRC_OPT_RECEIVE_RATE\n",
599 dccp_role(sk), sk, len);
602 opt_recv->ccid3or_receive_rate =
603 ntohl(*(__be32 *)value);
604 ccid3_pr_debug("%s(%p), RECEIVE_RATE=%u\n",
606 opt_recv->ccid3or_receive_rate);
614 static int ccid3_hc_tx_init(struct ccid *ccid, struct sock *sk)
616 struct ccid3_hc_tx_sock *hctx = ccid_priv(ccid);
618 hctx->ccid3hctx_s = 0;
619 hctx->ccid3hctx_rtt = 0;
620 hctx->ccid3hctx_state = TFRC_SSTATE_NO_SENT;
621 INIT_LIST_HEAD(&hctx->ccid3hctx_hist);
623 hctx->ccid3hctx_no_feedback_timer.function =
624 ccid3_hc_tx_no_feedback_timer;
625 hctx->ccid3hctx_no_feedback_timer.data = (unsigned long)sk;
626 init_timer(&hctx->ccid3hctx_no_feedback_timer);
631 static void ccid3_hc_tx_exit(struct sock *sk)
633 struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
635 BUG_ON(hctx == NULL);
637 ccid3_hc_tx_set_state(sk, TFRC_SSTATE_TERM);
638 sk_stop_timer(sk, &hctx->ccid3hctx_no_feedback_timer);
640 /* Empty packet history */
641 dccp_tx_hist_purge(ccid3_tx_hist, &hctx->ccid3hctx_hist);
645 * RX Half Connection methods
648 #ifdef CONFIG_IP_DCCP_CCID3_DEBUG
649 static const char *ccid3_rx_state_name(enum ccid3_hc_rx_states state)
651 static char *ccid3_rx_state_names[] = {
652 [TFRC_RSTATE_NO_DATA] = "NO_DATA",
653 [TFRC_RSTATE_DATA] = "DATA",
654 [TFRC_RSTATE_TERM] = "TERM",
657 return ccid3_rx_state_names[state];
661 static void ccid3_hc_rx_set_state(struct sock *sk,
662 enum ccid3_hc_rx_states state)
664 struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
665 enum ccid3_hc_rx_states oldstate = hcrx->ccid3hcrx_state;
667 ccid3_pr_debug("%s(%p) %-8.8s -> %s\n",
668 dccp_role(sk), sk, ccid3_rx_state_name(oldstate),
669 ccid3_rx_state_name(state));
670 WARN_ON(state == oldstate);
671 hcrx->ccid3hcrx_state = state;
674 static inline void ccid3_hc_rx_update_s(struct ccid3_hc_rx_sock *hcrx, int len)
676 if (unlikely(len == 0)) /* don't update on empty packets (e.g. ACKs) */
677 ccid3_pr_debug("Packet payload length is 0 - not updating\n");
679 hcrx->ccid3hcrx_s = hcrx->ccid3hcrx_s == 0 ? len :
680 (9 * hcrx->ccid3hcrx_s + len) / 10;
683 static void ccid3_hc_rx_send_feedback(struct sock *sk)
685 struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
686 struct dccp_sock *dp = dccp_sk(sk);
687 struct dccp_rx_hist_entry *packet;
691 ccid3_pr_debug("%s(%p) - entry \n", dccp_role(sk), sk);
693 dccp_timestamp(sk, &now);
695 switch (hcrx->ccid3hcrx_state) {
696 case TFRC_RSTATE_NO_DATA:
697 hcrx->ccid3hcrx_x_recv = 0;
699 case TFRC_RSTATE_DATA:
700 delta = timeval_delta(&now,
701 &hcrx->ccid3hcrx_tstamp_last_feedback);
702 DCCP_BUG_ON(delta < 0);
703 hcrx->ccid3hcrx_x_recv =
704 scaled_div32(hcrx->ccid3hcrx_bytes_recv, delta);
706 case TFRC_RSTATE_TERM:
707 DCCP_BUG("%s(%p) - Illegal state TERM", dccp_role(sk), sk);
711 packet = dccp_rx_hist_find_data_packet(&hcrx->ccid3hcrx_hist);
712 if (unlikely(packet == NULL)) {
713 DCCP_WARN("%s(%p), no data packet in history!\n",
718 hcrx->ccid3hcrx_tstamp_last_feedback = now;
719 hcrx->ccid3hcrx_ccval_last_counter = packet->dccphrx_ccval;
720 hcrx->ccid3hcrx_bytes_recv = 0;
722 /* Elapsed time information [RFC 4340, 13.2] in units of 10 * usecs */
723 delta = timeval_delta(&now, &packet->dccphrx_tstamp);
724 DCCP_BUG_ON(delta < 0);
725 hcrx->ccid3hcrx_elapsed_time = delta / 10;
727 if (hcrx->ccid3hcrx_p == 0)
728 hcrx->ccid3hcrx_pinv = ~0U; /* see RFC 4342, 8.5 */
729 else if (hcrx->ccid3hcrx_p > 1000000) {
730 DCCP_WARN("p (%u) > 100%%\n", hcrx->ccid3hcrx_p);
731 hcrx->ccid3hcrx_pinv = 1; /* use 100% in this case */
733 hcrx->ccid3hcrx_pinv = 1000000 / hcrx->ccid3hcrx_p;
735 dp->dccps_hc_rx_insert_options = 1;
739 static int ccid3_hc_rx_insert_options(struct sock *sk, struct sk_buff *skb)
741 const struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
744 BUG_ON(hcrx == NULL);
746 if (!(sk->sk_state == DCCP_OPEN || sk->sk_state == DCCP_PARTOPEN))
749 DCCP_SKB_CB(skb)->dccpd_ccval = hcrx->ccid3hcrx_ccval_last_counter;
751 if (dccp_packet_without_ack(skb))
754 x_recv = htonl(hcrx->ccid3hcrx_x_recv);
755 pinv = htonl(hcrx->ccid3hcrx_pinv);
757 if ((hcrx->ccid3hcrx_elapsed_time != 0 &&
758 dccp_insert_option_elapsed_time(sk, skb,
759 hcrx->ccid3hcrx_elapsed_time)) ||
760 dccp_insert_option_timestamp(sk, skb) ||
761 dccp_insert_option(sk, skb, TFRC_OPT_LOSS_EVENT_RATE,
762 &pinv, sizeof(pinv)) ||
763 dccp_insert_option(sk, skb, TFRC_OPT_RECEIVE_RATE,
764 &x_recv, sizeof(x_recv)))
770 /* calculate first loss interval
772 * returns estimated loss interval in usecs */
774 static u32 ccid3_hc_rx_calc_first_li(struct sock *sk)
776 struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
777 struct dccp_rx_hist_entry *entry, *next, *tail = NULL;
779 suseconds_t rtt, delta;
780 struct timeval tstamp = { 0, };
786 list_for_each_entry_safe(entry, next, &hcrx->ccid3hcrx_hist,
788 if (dccp_rx_hist_entry_data_packet(entry)) {
793 tstamp = entry->dccphrx_tstamp;
794 win_count = entry->dccphrx_ccval;
798 interval = win_count - entry->dccphrx_ccval;
800 interval += TFRC_WIN_COUNT_LIMIT;
808 if (unlikely(step == 0)) {
809 DCCP_WARN("%s(%p), packet history has no data packets!\n",
814 if (unlikely(interval == 0)) {
815 DCCP_WARN("%s(%p), Could not find a win_count interval > 0."
816 "Defaulting to 1\n", dccp_role(sk), sk);
821 DCCP_CRIT("tail is null\n");
825 delta = timeval_delta(&tstamp, &tail->dccphrx_tstamp);
826 DCCP_BUG_ON(delta < 0);
828 rtt = delta * 4 / interval;
829 ccid3_pr_debug("%s(%p), approximated RTT to %dus\n",
830 dccp_role(sk), sk, (int)rtt);
833 * Determine the length of the first loss interval via inverse lookup.
834 * Assume that X_recv can be computed by the throughput equation
838 * Find some p such that f(p) = fval; return 1/p [RFC 3448, 6.3.1].
840 if (rtt == 0) { /* would result in divide-by-zero */
841 DCCP_WARN("RTT==0\n");
845 dccp_timestamp(sk, &tstamp);
846 delta = timeval_delta(&tstamp, &hcrx->ccid3hcrx_tstamp_last_feedback);
847 DCCP_BUG_ON(delta <= 0);
849 x_recv = scaled_div32(hcrx->ccid3hcrx_bytes_recv, delta);
850 if (x_recv == 0) { /* would also trigger divide-by-zero */
851 DCCP_WARN("X_recv==0\n");
852 if ((x_recv = hcrx->ccid3hcrx_x_recv) == 0) {
853 DCCP_BUG("stored value of X_recv is zero");
858 fval = scaled_div(hcrx->ccid3hcrx_s, rtt);
859 fval = scaled_div32(fval, x_recv);
860 p = tfrc_calc_x_reverse_lookup(fval);
862 ccid3_pr_debug("%s(%p), receive rate=%u bytes/s, implied "
863 "loss rate=%u\n", dccp_role(sk), sk, x_recv, p);
871 static void ccid3_hc_rx_update_li(struct sock *sk, u64 seq_loss, u8 win_loss)
873 struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
874 struct dccp_li_hist_entry *head;
877 if (list_empty(&hcrx->ccid3hcrx_li_hist)) {
878 if (!dccp_li_hist_interval_new(ccid3_li_hist,
879 &hcrx->ccid3hcrx_li_hist, seq_loss, win_loss))
882 head = list_entry(hcrx->ccid3hcrx_li_hist.next,
883 struct dccp_li_hist_entry, dccplih_node);
884 head->dccplih_interval = ccid3_hc_rx_calc_first_li(sk);
886 struct dccp_li_hist_entry *entry;
887 struct list_head *tail;
889 head = list_entry(hcrx->ccid3hcrx_li_hist.next,
890 struct dccp_li_hist_entry, dccplih_node);
891 /* FIXME win count check removed as was wrong */
892 /* should make this check with receive history */
893 /* and compare there as per section 10.2 of RFC4342 */
895 /* new loss event detected */
896 /* calculate last interval length */
897 seq_temp = dccp_delta_seqno(head->dccplih_seqno, seq_loss);
898 entry = dccp_li_hist_entry_new(ccid3_li_hist, GFP_ATOMIC);
901 DCCP_BUG("out of memory - can not allocate entry");
905 list_add(&entry->dccplih_node, &hcrx->ccid3hcrx_li_hist);
907 tail = hcrx->ccid3hcrx_li_hist.prev;
909 kmem_cache_free(ccid3_li_hist->dccplih_slab, tail);
911 /* Create the newest interval */
912 entry->dccplih_seqno = seq_loss;
913 entry->dccplih_interval = seq_temp;
914 entry->dccplih_win_count = win_loss;
918 static int ccid3_hc_rx_detect_loss(struct sock *sk,
919 struct dccp_rx_hist_entry *packet)
921 struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
922 struct dccp_rx_hist_entry *rx_hist =
923 dccp_rx_hist_head(&hcrx->ccid3hcrx_hist);
924 u64 seqno = packet->dccphrx_seqno;
930 tmp_seqno = hcrx->ccid3hcrx_seqno_nonloss;
933 follows48(packet->dccphrx_seqno, hcrx->ccid3hcrx_seqno_nonloss)) {
934 hcrx->ccid3hcrx_seqno_nonloss = seqno;
935 hcrx->ccid3hcrx_ccval_nonloss = packet->dccphrx_ccval;
940 while (dccp_delta_seqno(hcrx->ccid3hcrx_seqno_nonloss, seqno)
941 > TFRC_RECV_NUM_LATE_LOSS) {
943 ccid3_hc_rx_update_li(sk, hcrx->ccid3hcrx_seqno_nonloss,
944 hcrx->ccid3hcrx_ccval_nonloss);
945 tmp_seqno = hcrx->ccid3hcrx_seqno_nonloss;
946 dccp_inc_seqno(&tmp_seqno);
947 hcrx->ccid3hcrx_seqno_nonloss = tmp_seqno;
948 dccp_inc_seqno(&tmp_seqno);
949 while (dccp_rx_hist_find_entry(&hcrx->ccid3hcrx_hist,
950 tmp_seqno, &ccval)) {
951 hcrx->ccid3hcrx_seqno_nonloss = tmp_seqno;
952 hcrx->ccid3hcrx_ccval_nonloss = ccval;
953 dccp_inc_seqno(&tmp_seqno);
957 /* FIXME - this code could be simplified with above while */
958 /* but works at moment */
959 if (follows48(packet->dccphrx_seqno, hcrx->ccid3hcrx_seqno_nonloss)) {
960 hcrx->ccid3hcrx_seqno_nonloss = seqno;
961 hcrx->ccid3hcrx_ccval_nonloss = packet->dccphrx_ccval;
965 dccp_rx_hist_add_packet(ccid3_rx_hist, &hcrx->ccid3hcrx_hist,
966 &hcrx->ccid3hcrx_li_hist, packet,
967 hcrx->ccid3hcrx_seqno_nonloss);
971 static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb)
973 struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
974 const struct dccp_options_received *opt_recv;
975 struct dccp_rx_hist_entry *packet;
977 u32 p_prev, rtt_prev;
978 suseconds_t r_sample, t_elapsed;
979 int loss, payload_size;
981 BUG_ON(hcrx == NULL);
983 opt_recv = &dccp_sk(sk)->dccps_options_received;
985 switch (DCCP_SKB_CB(skb)->dccpd_type) {
987 if (hcrx->ccid3hcrx_state == TFRC_RSTATE_NO_DATA)
989 case DCCP_PKT_DATAACK:
990 if (opt_recv->dccpor_timestamp_echo == 0)
992 rtt_prev = hcrx->ccid3hcrx_rtt;
993 dccp_timestamp(sk, &now);
994 timeval_sub_usecs(&now, opt_recv->dccpor_timestamp_echo * 10);
995 r_sample = timeval_usecs(&now);
996 t_elapsed = opt_recv->dccpor_elapsed_time * 10;
998 DCCP_BUG_ON(r_sample < 0);
999 if (unlikely(r_sample <= t_elapsed))
1000 DCCP_WARN("r_sample=%ldus, t_elapsed=%ldus\n",
1001 (long)r_sample, (long)t_elapsed);
1003 r_sample -= t_elapsed;
1004 CCID3_RTT_SANITY_CHECK(r_sample);
1006 if (hcrx->ccid3hcrx_state == TFRC_RSTATE_NO_DATA)
1007 hcrx->ccid3hcrx_rtt = r_sample;
1009 hcrx->ccid3hcrx_rtt = (hcrx->ccid3hcrx_rtt * 9) / 10 +
1012 if (rtt_prev != hcrx->ccid3hcrx_rtt)
1013 ccid3_pr_debug("%s(%p), New RTT=%uus, elapsed time=%u\n",
1014 dccp_role(sk), sk, hcrx->ccid3hcrx_rtt,
1015 opt_recv->dccpor_elapsed_time);
1019 default: /* We're not interested in other packet types, move along */
1023 packet = dccp_rx_hist_entry_new(ccid3_rx_hist, sk, opt_recv->dccpor_ndp,
1025 if (unlikely(packet == NULL)) {
1026 DCCP_WARN("%s(%p), Not enough mem to add rx packet "
1027 "to history, consider it lost!\n", dccp_role(sk), sk);
1031 loss = ccid3_hc_rx_detect_loss(sk, packet);
1033 if (DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_ACK)
1036 payload_size = skb->len - dccp_hdr(skb)->dccph_doff * 4;
1037 ccid3_hc_rx_update_s(hcrx, payload_size);
1039 switch (hcrx->ccid3hcrx_state) {
1040 case TFRC_RSTATE_NO_DATA:
1041 ccid3_pr_debug("%s(%p, state=%s), skb=%p, sending initial "
1042 "feedback\n", dccp_role(sk), sk,
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 (suseconds_t)hcrx->ccid3hcrx_rtt) >= 0) {
1055 hcrx->ccid3hcrx_tstamp_last_ack = now;
1056 ccid3_hc_rx_send_feedback(sk);
1059 case TFRC_RSTATE_TERM:
1060 DCCP_BUG("%s(%p) - Illegal state TERM", dccp_role(sk), sk);
1064 /* Dealing with packet loss */
1065 ccid3_pr_debug("%s(%p, state=%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("entry\n");
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 = 0;
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_parse_options = ccid3_hc_tx_parse_options,
1211 .ccid_hc_rx_obj_size = sizeof(struct ccid3_hc_rx_sock),
1212 .ccid_hc_rx_init = ccid3_hc_rx_init,
1213 .ccid_hc_rx_exit = ccid3_hc_rx_exit,
1214 .ccid_hc_rx_insert_options = ccid3_hc_rx_insert_options,
1215 .ccid_hc_rx_packet_recv = ccid3_hc_rx_packet_recv,
1216 .ccid_hc_rx_get_info = ccid3_hc_rx_get_info,
1217 .ccid_hc_tx_get_info = ccid3_hc_tx_get_info,
1218 .ccid_hc_rx_getsockopt = ccid3_hc_rx_getsockopt,
1219 .ccid_hc_tx_getsockopt = ccid3_hc_tx_getsockopt,
1222 #ifdef CONFIG_IP_DCCP_CCID3_DEBUG
1223 module_param(ccid3_debug, int, 0444);
1224 MODULE_PARM_DESC(ccid3_debug, "Enable debug messages");
1227 static __init int ccid3_module_init(void)
1231 ccid3_rx_hist = dccp_rx_hist_new("ccid3");
1232 if (ccid3_rx_hist == NULL)
1235 ccid3_tx_hist = dccp_tx_hist_new("ccid3");
1236 if (ccid3_tx_hist == NULL)
1239 ccid3_li_hist = dccp_li_hist_new("ccid3");
1240 if (ccid3_li_hist == NULL)
1243 rc = ccid_register(&ccid3);
1245 goto out_free_loss_interval_history;
1249 out_free_loss_interval_history:
1250 dccp_li_hist_delete(ccid3_li_hist);
1251 ccid3_li_hist = NULL;
1253 dccp_tx_hist_delete(ccid3_tx_hist);
1254 ccid3_tx_hist = NULL;
1256 dccp_rx_hist_delete(ccid3_rx_hist);
1257 ccid3_rx_hist = NULL;
1260 module_init(ccid3_module_init);
1262 static __exit void ccid3_module_exit(void)
1264 ccid_unregister(&ccid3);
1266 if (ccid3_tx_hist != NULL) {
1267 dccp_tx_hist_delete(ccid3_tx_hist);
1268 ccid3_tx_hist = NULL;
1270 if (ccid3_rx_hist != NULL) {
1271 dccp_rx_hist_delete(ccid3_rx_hist);
1272 ccid3_rx_hist = NULL;
1274 if (ccid3_li_hist != NULL) {
1275 dccp_li_hist_delete(ccid3_li_hist);
1276 ccid3_li_hist = NULL;
1279 module_exit(ccid3_module_exit);
1281 MODULE_AUTHOR("Ian McDonald <ian.mcdonald@jandi.co.nz>, "
1282 "Arnaldo Carvalho de Melo <acme@ghostprotocols.net>");
1283 MODULE_DESCRIPTION("DCCP TFRC CCID3 CCID");
1284 MODULE_LICENSE("GPL");
1285 MODULE_ALIAS("net-dccp-ccid-3");