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_t(u64, hctx->ccid3hctx_x_calc << 6,
127 hctx->ccid3hctx_x_recv * 2 );
128 hctx->ccid3hctx_x = max_t(u64, hctx->ccid3hctx_x,
129 (hctx->ccid3hctx_s << 6)/TFRC_T_MBI);
131 } else if (timeval_delta(now, &hctx->ccid3hctx_t_ld) -
132 (suseconds_t)hctx->ccid3hctx_rtt >= 0 ) {
134 hctx->ccid3hctx_x = max(2 * min(hctx->ccid3hctx_x,
135 hctx->ccid3hctx_x_recv),
136 scaled_div(hctx->ccid3hctx_s << 6,
137 hctx->ccid3hctx_rtt ));
138 hctx->ccid3hctx_t_ld = *now;
141 if (hctx->ccid3hctx_x != old_x)
142 ccid3_update_send_time(hctx);
146 * Track the mean packet size `s' (cf. RFC 4342, 5.3 and RFC 3448, 4.1)
147 * @len: DCCP packet payload size in bytes
149 static inline void ccid3_hc_tx_update_s(struct ccid3_hc_tx_sock *hctx, int len)
151 if (unlikely(len == 0))
152 ccid3_pr_debug("Packet payload length is 0 - not updating\n");
154 hctx->ccid3hctx_s = hctx->ccid3hctx_s == 0 ? len :
155 (9 * hctx->ccid3hctx_s + len) / 10;
157 * Note: We could do a potential optimisation here - when `s' changes,
158 * recalculate sending rate and consequently t_ipi, t_delta, and
159 * t_now. This is however non-standard, and the benefits are not
160 * clear, so it is currently left out.
165 * Update Window Counter using the algorithm from [RFC 4342, 8.1].
166 * The algorithm is not applicable if RTT < 4 microseconds.
168 static inline void ccid3_hc_tx_update_win_count(struct ccid3_hc_tx_sock *hctx,
174 if (unlikely(hctx->ccid3hctx_rtt < 4)) /* avoid divide-by-zero */
177 delta = timeval_delta(now, &hctx->ccid3hctx_t_last_win_count);
178 DCCP_BUG_ON(delta < 0);
180 quarter_rtts = (u32)delta / (hctx->ccid3hctx_rtt / 4);
182 if (quarter_rtts > 0) {
183 hctx->ccid3hctx_t_last_win_count = *now;
184 hctx->ccid3hctx_last_win_count += min_t(u32, quarter_rtts, 5);
185 hctx->ccid3hctx_last_win_count &= 0xF; /* mod 16 */
187 ccid3_pr_debug("now at %#X\n", hctx->ccid3hctx_last_win_count);
191 static void ccid3_hc_tx_no_feedback_timer(unsigned long data)
193 struct sock *sk = (struct sock *)data;
194 struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
195 unsigned long t_nfb = USEC_PER_SEC / 5;
198 if (sock_owned_by_user(sk)) {
199 /* Try again later. */
200 /* XXX: set some sensible MIB */
204 ccid3_pr_debug("%s(%p, state=%s) - entry \n", dccp_role(sk), sk,
205 ccid3_tx_state_name(hctx->ccid3hctx_state));
207 switch (hctx->ccid3hctx_state) {
208 case TFRC_SSTATE_NO_FBACK:
209 /* RFC 3448, 4.4: Halve send rate directly */
210 hctx->ccid3hctx_x = max_t(u32, hctx->ccid3hctx_x / 2,
211 (hctx->ccid3hctx_s << 6)/TFRC_T_MBI);
213 ccid3_pr_debug("%s(%p, state=%s), updated tx rate to %u "
214 "bytes/s\n", dccp_role(sk), sk,
215 ccid3_tx_state_name(hctx->ccid3hctx_state),
216 (unsigned)(hctx->ccid3hctx_x >> 6));
217 /* The value of R is still undefined and so we can not recompute
218 * the timout value. Keep initial value as per [RFC 4342, 5]. */
219 t_nfb = TFRC_INITIAL_TIMEOUT;
220 ccid3_update_send_time(hctx);
222 case TFRC_SSTATE_FBACK:
224 * Check if IDLE since last timeout and recv rate is less than
225 * 4 packets (in units of 64*bytes/sec) per RTT
227 if (!hctx->ccid3hctx_idle ||
228 (hctx->ccid3hctx_x_recv >= 4 *
229 scaled_div(hctx->ccid3hctx_s << 6, 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 > (hctx->ccid3hctx_x_recv >> 5)) {
251 hctx->ccid3hctx_x_recv =
252 max_t(u64, hctx->ccid3hctx_x_recv / 2,
253 (hctx->ccid3hctx_s << 6) /
256 if (hctx->ccid3hctx_p == 0)
257 dccp_timestamp(sk, &now);
259 hctx->ccid3hctx_x_recv = hctx->ccid3hctx_x_calc << 4;
261 /* Now recalculate X [RFC 3448, 4.3, step (4)] */
262 ccid3_hc_tx_update_x(sk, &now);
265 * Schedule no feedback timer to expire in
266 * max(t_RTO, 2 * s/X) = max(t_RTO, 2 * t_ipi)
267 * See comments in packet_recv() regarding the value of t_RTO.
269 t_nfb = max(hctx->ccid3hctx_t_rto, 2 * hctx->ccid3hctx_t_ipi);
271 case TFRC_SSTATE_NO_SENT:
272 DCCP_BUG("%s(%p) - Illegal state NO_SENT", dccp_role(sk), sk);
274 case TFRC_SSTATE_TERM:
278 hctx->ccid3hctx_idle = 1;
281 sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer,
282 jiffies + usecs_to_jiffies(t_nfb));
290 * > 0: delay (in msecs) that should pass before actually sending
291 * = 0: can send immediately
292 * < 0: error condition; do not send packet
294 static int ccid3_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb)
296 struct dccp_sock *dp = dccp_sk(sk);
297 struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
301 BUG_ON(hctx == NULL);
304 * This function is called only for Data and DataAck packets. Sending
305 * zero-sized Data(Ack)s is theoretically possible, but for congestion
306 * control this case is pathological - ignore it.
308 if (unlikely(skb->len == 0))
311 dccp_timestamp(sk, &now);
313 switch (hctx->ccid3hctx_state) {
314 case TFRC_SSTATE_NO_SENT:
315 sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer,
316 jiffies + usecs_to_jiffies(TFRC_INITIAL_TIMEOUT));
317 hctx->ccid3hctx_last_win_count = 0;
318 hctx->ccid3hctx_t_last_win_count = now;
319 ccid3_hc_tx_set_state(sk, TFRC_SSTATE_NO_FBACK);
321 /* Set initial sending rate X/s to 1pps (X is scaled by 2^6) */
322 ccid3_hc_tx_update_s(hctx, skb->len);
323 hctx->ccid3hctx_x = hctx->ccid3hctx_s << 6;
325 /* First timeout, according to [RFC 3448, 4.2], is 1 second */
326 hctx->ccid3hctx_t_ipi = USEC_PER_SEC;
327 /* Initial delta: minimum of 0.5 sec and t_gran/2 */
328 hctx->ccid3hctx_delta = TFRC_OPSYS_HALF_TIME_GRAN;
330 /* Set t_0 for initial packet */
331 hctx->ccid3hctx_t_nom = now;
333 case TFRC_SSTATE_NO_FBACK:
334 case TFRC_SSTATE_FBACK:
335 delay = timeval_delta(&hctx->ccid3hctx_t_nom, &now);
337 * Scheduling of packet transmissions [RFC 3448, 4.6]
339 * if (t_now > t_nom - delta)
340 * // send the packet now
342 * // send the packet in (t_nom - t_now) milliseconds.
344 if (delay - (suseconds_t)hctx->ccid3hctx_delta >= 0)
345 return delay / 1000L;
347 ccid3_hc_tx_update_win_count(hctx, &now);
349 case TFRC_SSTATE_TERM:
350 DCCP_BUG("%s(%p) - Illegal state TERM", dccp_role(sk), sk);
354 /* prepare to send now (add options etc.) */
355 dp->dccps_hc_tx_insert_options = 1;
356 DCCP_SKB_CB(skb)->dccpd_ccval = hctx->ccid3hctx_last_win_count;
358 /* set the nominal send time for the next following packet */
359 timeval_add_usecs(&hctx->ccid3hctx_t_nom, hctx->ccid3hctx_t_ipi);
364 static void ccid3_hc_tx_packet_sent(struct sock *sk, int more, unsigned int len)
366 struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
368 struct dccp_tx_hist_entry *packet;
370 BUG_ON(hctx == NULL);
372 ccid3_hc_tx_update_s(hctx, len);
374 packet = dccp_tx_hist_entry_new(ccid3_tx_hist, GFP_ATOMIC);
375 if (unlikely(packet == NULL)) {
376 DCCP_CRIT("packet history - out of memory!");
379 dccp_tx_hist_add_entry(&hctx->ccid3hctx_hist, packet);
381 dccp_timestamp(sk, &now);
382 packet->dccphtx_tstamp = now;
383 packet->dccphtx_seqno = dccp_sk(sk)->dccps_gss;
384 packet->dccphtx_rtt = hctx->ccid3hctx_rtt;
385 packet->dccphtx_sent = 1;
386 hctx->ccid3hctx_idle = 0;
389 static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb)
391 const struct dccp_sock *dp = dccp_sk(sk);
392 struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
393 struct ccid3_options_received *opt_recv;
394 struct dccp_tx_hist_entry *packet;
398 long r_sample, t_elapsed;
400 BUG_ON(hctx == NULL);
402 /* we are only interested in ACKs */
403 if (!(DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_ACK ||
404 DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_DATAACK))
407 opt_recv = &hctx->ccid3hctx_options_received;
409 switch (hctx->ccid3hctx_state) {
410 case TFRC_SSTATE_NO_FBACK:
411 case TFRC_SSTATE_FBACK:
412 /* get packet from history to look up t_recvdata */
413 packet = dccp_tx_hist_find_entry(&hctx->ccid3hctx_hist,
414 DCCP_SKB_CB(skb)->dccpd_ack_seq);
415 if (unlikely(packet == NULL)) {
416 DCCP_WARN("%s(%p), seqno %llu(%s) doesn't exist "
417 "in history!\n", dccp_role(sk), sk,
418 (unsigned long long)DCCP_SKB_CB(skb)->dccpd_ack_seq,
419 dccp_packet_name(DCCP_SKB_CB(skb)->dccpd_type));
423 /* Update receive rate in units of 64 * bytes/second */
424 hctx->ccid3hctx_x_recv = opt_recv->ccid3or_receive_rate << 6;
426 /* Update loss event rate */
427 pinv = opt_recv->ccid3or_loss_event_rate;
428 if (pinv == ~0U || pinv == 0) /* see RFC 4342, 8.5 */
429 hctx->ccid3hctx_p = 0;
430 else /* can not exceed 100% */
431 hctx->ccid3hctx_p = 1000000 / pinv;
433 dccp_timestamp(sk, &now);
436 * Calculate new round trip sample as per [RFC 3448, 4.3] by
437 * R_sample = (now - t_recvdata) - t_elapsed
439 r_sample = timeval_delta(&now, &packet->dccphtx_tstamp);
440 t_elapsed = dp->dccps_options_received.dccpor_elapsed_time * 10;
442 DCCP_BUG_ON(r_sample < 0);
443 if (unlikely(r_sample <= t_elapsed))
444 DCCP_WARN("WARNING: r_sample=%ldus <= t_elapsed=%ldus\n",
445 r_sample, t_elapsed);
447 r_sample -= t_elapsed;
448 CCID3_RTT_SANITY_CHECK(r_sample);
450 /* Update RTT estimate by
451 * If (No feedback recv)
454 * R = q * R + (1 - q) * R_sample;
456 * q is a constant, RFC 3448 recomments 0.9
458 if (hctx->ccid3hctx_state == TFRC_SSTATE_NO_FBACK) {
460 * Larger Initial Windows [RFC 4342, sec. 5]
461 * We deviate in that we use `s' instead of `MSS'.
463 u16 w_init = min( 4 * hctx->ccid3hctx_s,
464 max(2 * hctx->ccid3hctx_s, 4380));
465 hctx->ccid3hctx_rtt = r_sample;
466 hctx->ccid3hctx_x = scaled_div(w_init<< 6, r_sample);
467 hctx->ccid3hctx_t_ld = now;
469 ccid3_update_send_time(hctx);
471 ccid3_pr_debug("%s(%p), s=%u, w_init=%u, "
472 "R_sample=%ldus, X=%u\n", dccp_role(sk),
473 sk, hctx->ccid3hctx_s, w_init, r_sample,
474 (unsigned)(hctx->ccid3hctx_x >> 6));
476 ccid3_hc_tx_set_state(sk, TFRC_SSTATE_FBACK);
478 hctx->ccid3hctx_rtt = (9 * hctx->ccid3hctx_rtt +
479 (u32)r_sample ) / 10;
481 /* Update sending rate (step 4 of [RFC 3448, 4.3]) */
482 if (hctx->ccid3hctx_p > 0)
483 hctx->ccid3hctx_x_calc =
484 tfrc_calc_x(hctx->ccid3hctx_s,
487 ccid3_hc_tx_update_x(sk, &now);
489 ccid3_pr_debug("%s(%p), RTT=%uus (sample=%ldus), s=%u, "
490 "p=%u, X_calc=%u, X=%u\n", dccp_role(sk),
491 sk, hctx->ccid3hctx_rtt, r_sample,
492 hctx->ccid3hctx_s, hctx->ccid3hctx_p,
493 hctx->ccid3hctx_x_calc,
494 (unsigned)(hctx->ccid3hctx_x >> 6));
497 /* unschedule no feedback timer */
498 sk_stop_timer(sk, &hctx->ccid3hctx_no_feedback_timer);
500 /* remove all packets older than the one acked from history */
501 dccp_tx_hist_purge_older(ccid3_tx_hist,
502 &hctx->ccid3hctx_hist, packet);
504 * As we have calculated new ipi, delta, t_nom it is possible that
505 * we now can send a packet, so wake up dccp_wait_for_ccid
507 sk->sk_write_space(sk);
510 * Update timeout interval for the nofeedback timer.
511 * We use a configuration option to increase the lower bound.
512 * This can help avoid triggering the nofeedback timer too often
513 * ('spinning') on LANs with small RTTs.
515 hctx->ccid3hctx_t_rto = max_t(u32, 4 * hctx->ccid3hctx_rtt,
516 CONFIG_IP_DCCP_CCID3_RTO *
517 (USEC_PER_SEC/1000) );
519 * Schedule no feedback timer to expire in
520 * max(t_RTO, 2 * s/X) = max(t_RTO, 2 * t_ipi)
522 t_nfb = max(hctx->ccid3hctx_t_rto, 2 * hctx->ccid3hctx_t_ipi);
524 ccid3_pr_debug("%s(%p), Scheduled no feedback timer to "
525 "expire in %lu jiffies (%luus)\n", dccp_role(sk),
526 sk, usecs_to_jiffies(t_nfb), t_nfb);
528 sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer,
529 jiffies + usecs_to_jiffies(t_nfb));
532 hctx->ccid3hctx_idle = 1;
534 case TFRC_SSTATE_NO_SENT:
535 /* XXX when implementing bidirectional rx/tx check this again */
536 DCCP_WARN("Illegal ACK received - no packet sent\n");
538 case TFRC_SSTATE_TERM: /* ignore feedback when closing */
543 static int ccid3_hc_tx_parse_options(struct sock *sk, unsigned char option,
544 unsigned char len, u16 idx,
545 unsigned char *value)
548 const struct dccp_sock *dp = dccp_sk(sk);
549 struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
550 struct ccid3_options_received *opt_recv;
552 BUG_ON(hctx == NULL);
554 opt_recv = &hctx->ccid3hctx_options_received;
556 if (opt_recv->ccid3or_seqno != dp->dccps_gsr) {
557 opt_recv->ccid3or_seqno = dp->dccps_gsr;
558 opt_recv->ccid3or_loss_event_rate = ~0;
559 opt_recv->ccid3or_loss_intervals_idx = 0;
560 opt_recv->ccid3or_loss_intervals_len = 0;
561 opt_recv->ccid3or_receive_rate = 0;
565 case TFRC_OPT_LOSS_EVENT_RATE:
566 if (unlikely(len != 4)) {
567 DCCP_WARN("%s(%p), invalid len %d "
568 "for TFRC_OPT_LOSS_EVENT_RATE\n",
569 dccp_role(sk), sk, len);
572 opt_recv->ccid3or_loss_event_rate = ntohl(*(__be32 *)value);
573 ccid3_pr_debug("%s(%p), LOSS_EVENT_RATE=%u\n",
575 opt_recv->ccid3or_loss_event_rate);
578 case TFRC_OPT_LOSS_INTERVALS:
579 opt_recv->ccid3or_loss_intervals_idx = idx;
580 opt_recv->ccid3or_loss_intervals_len = len;
581 ccid3_pr_debug("%s(%p), LOSS_INTERVALS=(%u, %u)\n",
583 opt_recv->ccid3or_loss_intervals_idx,
584 opt_recv->ccid3or_loss_intervals_len);
586 case TFRC_OPT_RECEIVE_RATE:
587 if (unlikely(len != 4)) {
588 DCCP_WARN("%s(%p), invalid len %d "
589 "for TFRC_OPT_RECEIVE_RATE\n",
590 dccp_role(sk), sk, len);
593 opt_recv->ccid3or_receive_rate = ntohl(*(__be32 *)value);
594 ccid3_pr_debug("%s(%p), RECEIVE_RATE=%u\n",
596 opt_recv->ccid3or_receive_rate);
604 static int ccid3_hc_tx_init(struct ccid *ccid, struct sock *sk)
606 struct ccid3_hc_tx_sock *hctx = ccid_priv(ccid);
608 hctx->ccid3hctx_s = 0;
609 hctx->ccid3hctx_rtt = 0;
610 hctx->ccid3hctx_state = TFRC_SSTATE_NO_SENT;
611 INIT_LIST_HEAD(&hctx->ccid3hctx_hist);
613 hctx->ccid3hctx_no_feedback_timer.function = ccid3_hc_tx_no_feedback_timer;
614 hctx->ccid3hctx_no_feedback_timer.data = (unsigned long)sk;
615 init_timer(&hctx->ccid3hctx_no_feedback_timer);
620 static void ccid3_hc_tx_exit(struct sock *sk)
622 struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
624 BUG_ON(hctx == NULL);
626 ccid3_hc_tx_set_state(sk, TFRC_SSTATE_TERM);
627 sk_stop_timer(sk, &hctx->ccid3hctx_no_feedback_timer);
629 /* Empty packet history */
630 dccp_tx_hist_purge(ccid3_tx_hist, &hctx->ccid3hctx_hist);
634 * RX Half Connection methods
637 #ifdef CONFIG_IP_DCCP_CCID3_DEBUG
638 static const char *ccid3_rx_state_name(enum ccid3_hc_rx_states state)
640 static char *ccid3_rx_state_names[] = {
641 [TFRC_RSTATE_NO_DATA] = "NO_DATA",
642 [TFRC_RSTATE_DATA] = "DATA",
643 [TFRC_RSTATE_TERM] = "TERM",
646 return ccid3_rx_state_names[state];
650 static void ccid3_hc_rx_set_state(struct sock *sk,
651 enum ccid3_hc_rx_states state)
653 struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
654 enum ccid3_hc_rx_states oldstate = hcrx->ccid3hcrx_state;
656 ccid3_pr_debug("%s(%p) %-8.8s -> %s\n",
657 dccp_role(sk), sk, ccid3_rx_state_name(oldstate),
658 ccid3_rx_state_name(state));
659 WARN_ON(state == oldstate);
660 hcrx->ccid3hcrx_state = state;
663 static inline void ccid3_hc_rx_update_s(struct ccid3_hc_rx_sock *hcrx, int len)
665 if (unlikely(len == 0)) /* don't update on empty packets (e.g. ACKs) */
666 ccid3_pr_debug("Packet payload length is 0 - not updating\n");
668 hcrx->ccid3hcrx_s = hcrx->ccid3hcrx_s == 0 ? len :
669 (9 * hcrx->ccid3hcrx_s + len) / 10;
672 static void ccid3_hc_rx_send_feedback(struct sock *sk)
674 struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
675 struct dccp_sock *dp = dccp_sk(sk);
676 struct dccp_rx_hist_entry *packet;
680 ccid3_pr_debug("%s(%p) - entry \n", dccp_role(sk), sk);
682 dccp_timestamp(sk, &now);
684 switch (hcrx->ccid3hcrx_state) {
685 case TFRC_RSTATE_NO_DATA:
686 hcrx->ccid3hcrx_x_recv = 0;
688 case TFRC_RSTATE_DATA:
689 delta = timeval_delta(&now,
690 &hcrx->ccid3hcrx_tstamp_last_feedback);
691 DCCP_BUG_ON(delta < 0);
692 hcrx->ccid3hcrx_x_recv =
693 scaled_div32(hcrx->ccid3hcrx_bytes_recv, delta);
695 case TFRC_RSTATE_TERM:
696 DCCP_BUG("%s(%p) - Illegal state TERM", dccp_role(sk), sk);
700 packet = dccp_rx_hist_find_data_packet(&hcrx->ccid3hcrx_hist);
701 if (unlikely(packet == NULL)) {
702 DCCP_WARN("%s(%p), no data packet in history!\n",
707 hcrx->ccid3hcrx_tstamp_last_feedback = now;
708 hcrx->ccid3hcrx_ccval_last_counter = packet->dccphrx_ccval;
709 hcrx->ccid3hcrx_bytes_recv = 0;
711 /* Elapsed time information [RFC 4340, 13.2] in units of 10 * usecs */
712 delta = timeval_delta(&now, &packet->dccphrx_tstamp);
713 DCCP_BUG_ON(delta < 0);
714 hcrx->ccid3hcrx_elapsed_time = delta / 10;
716 if (hcrx->ccid3hcrx_p == 0)
717 hcrx->ccid3hcrx_pinv = ~0U; /* see RFC 4342, 8.5 */
718 else if (hcrx->ccid3hcrx_p > 1000000) {
719 DCCP_WARN("p (%u) > 100%%\n", hcrx->ccid3hcrx_p);
720 hcrx->ccid3hcrx_pinv = 1; /* use 100% in this case */
722 hcrx->ccid3hcrx_pinv = 1000000 / hcrx->ccid3hcrx_p;
724 dp->dccps_hc_rx_insert_options = 1;
728 static int ccid3_hc_rx_insert_options(struct sock *sk, struct sk_buff *skb)
730 const struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
733 BUG_ON(hcrx == NULL);
735 if (!(sk->sk_state == DCCP_OPEN || sk->sk_state == DCCP_PARTOPEN))
738 DCCP_SKB_CB(skb)->dccpd_ccval = hcrx->ccid3hcrx_ccval_last_counter;
740 if (dccp_packet_without_ack(skb))
743 x_recv = htonl(hcrx->ccid3hcrx_x_recv);
744 pinv = htonl(hcrx->ccid3hcrx_pinv);
746 if ((hcrx->ccid3hcrx_elapsed_time != 0 &&
747 dccp_insert_option_elapsed_time(sk, skb,
748 hcrx->ccid3hcrx_elapsed_time)) ||
749 dccp_insert_option_timestamp(sk, skb) ||
750 dccp_insert_option(sk, skb, TFRC_OPT_LOSS_EVENT_RATE,
751 &pinv, sizeof(pinv)) ||
752 dccp_insert_option(sk, skb, TFRC_OPT_RECEIVE_RATE,
753 &x_recv, sizeof(x_recv)))
759 /* calculate first loss interval
761 * returns estimated loss interval in usecs */
763 static u32 ccid3_hc_rx_calc_first_li(struct sock *sk)
765 struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
766 struct dccp_rx_hist_entry *entry, *next, *tail = NULL;
768 suseconds_t rtt, delta;
769 struct timeval tstamp = { 0, };
775 list_for_each_entry_safe(entry, next, &hcrx->ccid3hcrx_hist,
777 if (dccp_rx_hist_entry_data_packet(entry)) {
782 tstamp = entry->dccphrx_tstamp;
783 win_count = entry->dccphrx_ccval;
787 interval = win_count - entry->dccphrx_ccval;
789 interval += TFRC_WIN_COUNT_LIMIT;
797 if (unlikely(step == 0)) {
798 DCCP_WARN("%s(%p), packet history has no data packets!\n",
803 if (unlikely(interval == 0)) {
804 DCCP_WARN("%s(%p), Could not find a win_count interval > 0."
805 "Defaulting to 1\n", dccp_role(sk), sk);
810 DCCP_CRIT("tail is null\n");
814 delta = timeval_delta(&tstamp, &tail->dccphrx_tstamp);
815 DCCP_BUG_ON(delta < 0);
817 rtt = delta * 4 / interval;
818 ccid3_pr_debug("%s(%p), approximated RTT to %ldus\n",
819 dccp_role(sk), sk, rtt);
822 * Determine the length of the first loss interval via inverse lookup.
823 * Assume that X_recv can be computed by the throughput equation
827 * Find some p such that f(p) = fval; return 1/p [RFC 3448, 6.3.1].
829 if (rtt == 0) { /* would result in divide-by-zero */
830 DCCP_WARN("RTT==0, returning 1/p = 1\n");
834 dccp_timestamp(sk, &tstamp);
835 delta = timeval_delta(&tstamp, &hcrx->ccid3hcrx_tstamp_last_feedback);
836 DCCP_BUG_ON(delta <= 0);
838 x_recv = scaled_div32(hcrx->ccid3hcrx_bytes_recv, delta);
839 if (x_recv == 0) { /* would also trigger divide-by-zero */
840 DCCP_WARN("X_recv==0\n");
841 if ((x_recv = hcrx->ccid3hcrx_x_recv) == 0) {
842 DCCP_BUG("stored value of X_recv is zero");
847 fval = scaled_div(hcrx->ccid3hcrx_s, rtt);
848 fval = scaled_div32(fval, x_recv);
849 p = tfrc_calc_x_reverse_lookup(fval);
851 ccid3_pr_debug("%s(%p), receive rate=%u bytes/s, implied "
852 "loss rate=%u\n", dccp_role(sk), sk, x_recv, p);
860 static void ccid3_hc_rx_update_li(struct sock *sk, u64 seq_loss, u8 win_loss)
862 struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
863 struct dccp_li_hist_entry *head;
866 if (list_empty(&hcrx->ccid3hcrx_li_hist)) {
867 if (!dccp_li_hist_interval_new(ccid3_li_hist,
868 &hcrx->ccid3hcrx_li_hist, seq_loss, win_loss))
871 head = list_entry(hcrx->ccid3hcrx_li_hist.next,
872 struct dccp_li_hist_entry, dccplih_node);
873 head->dccplih_interval = ccid3_hc_rx_calc_first_li(sk);
875 struct dccp_li_hist_entry *entry;
876 struct list_head *tail;
878 head = list_entry(hcrx->ccid3hcrx_li_hist.next,
879 struct dccp_li_hist_entry, dccplih_node);
880 /* FIXME win count check removed as was wrong */
881 /* should make this check with receive history */
882 /* and compare there as per section 10.2 of RFC4342 */
884 /* new loss event detected */
885 /* calculate last interval length */
886 seq_temp = dccp_delta_seqno(head->dccplih_seqno, seq_loss);
887 entry = dccp_li_hist_entry_new(ccid3_li_hist, GFP_ATOMIC);
890 DCCP_BUG("out of memory - can not allocate entry");
894 list_add(&entry->dccplih_node, &hcrx->ccid3hcrx_li_hist);
896 tail = hcrx->ccid3hcrx_li_hist.prev;
898 kmem_cache_free(ccid3_li_hist->dccplih_slab, tail);
900 /* Create the newest interval */
901 entry->dccplih_seqno = seq_loss;
902 entry->dccplih_interval = seq_temp;
903 entry->dccplih_win_count = win_loss;
907 static int ccid3_hc_rx_detect_loss(struct sock *sk,
908 struct dccp_rx_hist_entry *packet)
910 struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
911 struct dccp_rx_hist_entry *rx_hist = dccp_rx_hist_head(&hcrx->ccid3hcrx_hist);
912 u64 seqno = packet->dccphrx_seqno;
918 tmp_seqno = hcrx->ccid3hcrx_seqno_nonloss;
921 follows48(packet->dccphrx_seqno, hcrx->ccid3hcrx_seqno_nonloss)) {
922 hcrx->ccid3hcrx_seqno_nonloss = seqno;
923 hcrx->ccid3hcrx_ccval_nonloss = packet->dccphrx_ccval;
928 while (dccp_delta_seqno(hcrx->ccid3hcrx_seqno_nonloss, seqno)
929 > TFRC_RECV_NUM_LATE_LOSS) {
931 ccid3_hc_rx_update_li(sk, hcrx->ccid3hcrx_seqno_nonloss,
932 hcrx->ccid3hcrx_ccval_nonloss);
933 tmp_seqno = hcrx->ccid3hcrx_seqno_nonloss;
934 dccp_inc_seqno(&tmp_seqno);
935 hcrx->ccid3hcrx_seqno_nonloss = tmp_seqno;
936 dccp_inc_seqno(&tmp_seqno);
937 while (dccp_rx_hist_find_entry(&hcrx->ccid3hcrx_hist,
938 tmp_seqno, &ccval)) {
939 hcrx->ccid3hcrx_seqno_nonloss = tmp_seqno;
940 hcrx->ccid3hcrx_ccval_nonloss = ccval;
941 dccp_inc_seqno(&tmp_seqno);
945 /* FIXME - this code could be simplified with above while */
946 /* but works at moment */
947 if (follows48(packet->dccphrx_seqno, hcrx->ccid3hcrx_seqno_nonloss)) {
948 hcrx->ccid3hcrx_seqno_nonloss = seqno;
949 hcrx->ccid3hcrx_ccval_nonloss = packet->dccphrx_ccval;
953 dccp_rx_hist_add_packet(ccid3_rx_hist, &hcrx->ccid3hcrx_hist,
954 &hcrx->ccid3hcrx_li_hist, packet,
955 hcrx->ccid3hcrx_seqno_nonloss);
959 static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb)
961 struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
962 const struct dccp_options_received *opt_recv;
963 struct dccp_rx_hist_entry *packet;
965 u32 p_prev, rtt_prev;
966 suseconds_t r_sample, t_elapsed;
967 int loss, payload_size;
969 BUG_ON(hcrx == NULL);
971 opt_recv = &dccp_sk(sk)->dccps_options_received;
973 switch (DCCP_SKB_CB(skb)->dccpd_type) {
975 if (hcrx->ccid3hcrx_state == TFRC_RSTATE_NO_DATA)
977 case DCCP_PKT_DATAACK:
978 if (opt_recv->dccpor_timestamp_echo == 0)
980 rtt_prev = hcrx->ccid3hcrx_rtt;
981 dccp_timestamp(sk, &now);
982 timeval_sub_usecs(&now, opt_recv->dccpor_timestamp_echo * 10);
983 r_sample = timeval_usecs(&now);
984 t_elapsed = opt_recv->dccpor_elapsed_time * 10;
986 DCCP_BUG_ON(r_sample < 0);
987 if (unlikely(r_sample <= t_elapsed))
988 DCCP_WARN("r_sample=%ldus, t_elapsed=%ldus\n",
989 r_sample, t_elapsed);
991 r_sample -= t_elapsed;
992 CCID3_RTT_SANITY_CHECK(r_sample);
994 if (hcrx->ccid3hcrx_state == TFRC_RSTATE_NO_DATA)
995 hcrx->ccid3hcrx_rtt = r_sample;
997 hcrx->ccid3hcrx_rtt = (hcrx->ccid3hcrx_rtt * 9) / 10 +
1000 if (rtt_prev != hcrx->ccid3hcrx_rtt)
1001 ccid3_pr_debug("%s(%p), New RTT=%uus, elapsed time=%u\n",
1002 dccp_role(sk), sk, hcrx->ccid3hcrx_rtt,
1003 opt_recv->dccpor_elapsed_time);
1007 default: /* We're not interested in other packet types, move along */
1011 packet = dccp_rx_hist_entry_new(ccid3_rx_hist, sk, opt_recv->dccpor_ndp,
1013 if (unlikely(packet == NULL)) {
1014 DCCP_WARN("%s(%p), Not enough mem to add rx packet "
1015 "to history, consider it lost!\n", dccp_role(sk), sk);
1019 loss = ccid3_hc_rx_detect_loss(sk, packet);
1021 if (DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_ACK)
1024 payload_size = skb->len - dccp_hdr(skb)->dccph_doff * 4;
1025 ccid3_hc_rx_update_s(hcrx, payload_size);
1027 switch (hcrx->ccid3hcrx_state) {
1028 case TFRC_RSTATE_NO_DATA:
1029 ccid3_pr_debug("%s(%p, state=%s), skb=%p, sending initial "
1030 "feedback\n", dccp_role(sk), sk,
1031 dccp_state_name(sk->sk_state), skb);
1032 ccid3_hc_rx_send_feedback(sk);
1033 ccid3_hc_rx_set_state(sk, TFRC_RSTATE_DATA);
1035 case TFRC_RSTATE_DATA:
1036 hcrx->ccid3hcrx_bytes_recv += payload_size;
1040 dccp_timestamp(sk, &now);
1041 if (timeval_delta(&now, &hcrx->ccid3hcrx_tstamp_last_ack) -
1042 (suseconds_t)hcrx->ccid3hcrx_rtt >= 0) {
1043 hcrx->ccid3hcrx_tstamp_last_ack = now;
1044 ccid3_hc_rx_send_feedback(sk);
1047 case TFRC_RSTATE_TERM:
1048 DCCP_BUG("%s(%p) - Illegal state TERM", dccp_role(sk), sk);
1052 /* Dealing with packet loss */
1053 ccid3_pr_debug("%s(%p, state=%s), data loss! Reacting...\n",
1054 dccp_role(sk), sk, dccp_state_name(sk->sk_state));
1056 p_prev = hcrx->ccid3hcrx_p;
1058 /* Calculate loss event rate */
1059 if (!list_empty(&hcrx->ccid3hcrx_li_hist)) {
1060 u32 i_mean = dccp_li_hist_calc_i_mean(&hcrx->ccid3hcrx_li_hist);
1062 /* Scaling up by 1000000 as fixed decimal */
1064 hcrx->ccid3hcrx_p = 1000000 / i_mean;
1066 DCCP_BUG("empty loss history");
1068 if (hcrx->ccid3hcrx_p > p_prev) {
1069 ccid3_hc_rx_send_feedback(sk);
1074 static int ccid3_hc_rx_init(struct ccid *ccid, struct sock *sk)
1076 struct ccid3_hc_rx_sock *hcrx = ccid_priv(ccid);
1078 ccid3_pr_debug("entry\n");
1080 hcrx->ccid3hcrx_state = TFRC_RSTATE_NO_DATA;
1081 INIT_LIST_HEAD(&hcrx->ccid3hcrx_hist);
1082 INIT_LIST_HEAD(&hcrx->ccid3hcrx_li_hist);
1083 dccp_timestamp(sk, &hcrx->ccid3hcrx_tstamp_last_ack);
1084 hcrx->ccid3hcrx_tstamp_last_feedback = hcrx->ccid3hcrx_tstamp_last_ack;
1085 hcrx->ccid3hcrx_s = 0;
1086 hcrx->ccid3hcrx_rtt = 0;
1090 static void ccid3_hc_rx_exit(struct sock *sk)
1092 struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
1094 BUG_ON(hcrx == NULL);
1096 ccid3_hc_rx_set_state(sk, TFRC_RSTATE_TERM);
1098 /* Empty packet history */
1099 dccp_rx_hist_purge(ccid3_rx_hist, &hcrx->ccid3hcrx_hist);
1101 /* Empty loss interval history */
1102 dccp_li_hist_purge(ccid3_li_hist, &hcrx->ccid3hcrx_li_hist);
1105 static void ccid3_hc_rx_get_info(struct sock *sk, struct tcp_info *info)
1107 const struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
1109 /* Listen socks doesn't have a private CCID block */
1110 if (sk->sk_state == DCCP_LISTEN)
1113 BUG_ON(hcrx == NULL);
1115 info->tcpi_ca_state = hcrx->ccid3hcrx_state;
1116 info->tcpi_options |= TCPI_OPT_TIMESTAMPS;
1117 info->tcpi_rcv_rtt = hcrx->ccid3hcrx_rtt;
1120 static void ccid3_hc_tx_get_info(struct sock *sk, struct tcp_info *info)
1122 const struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
1124 /* Listen socks doesn't have a private CCID block */
1125 if (sk->sk_state == DCCP_LISTEN)
1128 BUG_ON(hctx == NULL);
1130 info->tcpi_rto = hctx->ccid3hctx_t_rto;
1131 info->tcpi_rtt = hctx->ccid3hctx_rtt;
1134 static int ccid3_hc_rx_getsockopt(struct sock *sk, const int optname, int len,
1135 u32 __user *optval, int __user *optlen)
1137 const struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
1140 /* Listen socks doesn't have a private CCID block */
1141 if (sk->sk_state == DCCP_LISTEN)
1145 case DCCP_SOCKOPT_CCID_RX_INFO:
1146 if (len < sizeof(hcrx->ccid3hcrx_tfrc))
1148 len = sizeof(hcrx->ccid3hcrx_tfrc);
1149 val = &hcrx->ccid3hcrx_tfrc;
1152 return -ENOPROTOOPT;
1155 if (put_user(len, optlen) || copy_to_user(optval, val, len))
1161 static int ccid3_hc_tx_getsockopt(struct sock *sk, const int optname, int len,
1162 u32 __user *optval, int __user *optlen)
1164 const struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
1167 /* Listen socks doesn't have a private CCID block */
1168 if (sk->sk_state == DCCP_LISTEN)
1172 case DCCP_SOCKOPT_CCID_TX_INFO:
1173 if (len < sizeof(hctx->ccid3hctx_tfrc))
1175 len = sizeof(hctx->ccid3hctx_tfrc);
1176 val = &hctx->ccid3hctx_tfrc;
1179 return -ENOPROTOOPT;
1182 if (put_user(len, optlen) || copy_to_user(optval, val, len))
1188 static struct ccid_operations ccid3 = {
1189 .ccid_id = DCCPC_CCID3,
1190 .ccid_name = "ccid3",
1191 .ccid_owner = THIS_MODULE,
1192 .ccid_hc_tx_obj_size = sizeof(struct ccid3_hc_tx_sock),
1193 .ccid_hc_tx_init = ccid3_hc_tx_init,
1194 .ccid_hc_tx_exit = ccid3_hc_tx_exit,
1195 .ccid_hc_tx_send_packet = ccid3_hc_tx_send_packet,
1196 .ccid_hc_tx_packet_sent = ccid3_hc_tx_packet_sent,
1197 .ccid_hc_tx_packet_recv = ccid3_hc_tx_packet_recv,
1198 .ccid_hc_tx_parse_options = ccid3_hc_tx_parse_options,
1199 .ccid_hc_rx_obj_size = sizeof(struct ccid3_hc_rx_sock),
1200 .ccid_hc_rx_init = ccid3_hc_rx_init,
1201 .ccid_hc_rx_exit = ccid3_hc_rx_exit,
1202 .ccid_hc_rx_insert_options = ccid3_hc_rx_insert_options,
1203 .ccid_hc_rx_packet_recv = ccid3_hc_rx_packet_recv,
1204 .ccid_hc_rx_get_info = ccid3_hc_rx_get_info,
1205 .ccid_hc_tx_get_info = ccid3_hc_tx_get_info,
1206 .ccid_hc_rx_getsockopt = ccid3_hc_rx_getsockopt,
1207 .ccid_hc_tx_getsockopt = ccid3_hc_tx_getsockopt,
1210 #ifdef CONFIG_IP_DCCP_CCID3_DEBUG
1211 module_param(ccid3_debug, int, 0444);
1212 MODULE_PARM_DESC(ccid3_debug, "Enable debug messages");
1215 static __init int ccid3_module_init(void)
1219 ccid3_rx_hist = dccp_rx_hist_new("ccid3");
1220 if (ccid3_rx_hist == NULL)
1223 ccid3_tx_hist = dccp_tx_hist_new("ccid3");
1224 if (ccid3_tx_hist == NULL)
1227 ccid3_li_hist = dccp_li_hist_new("ccid3");
1228 if (ccid3_li_hist == NULL)
1231 rc = ccid_register(&ccid3);
1233 goto out_free_loss_interval_history;
1237 out_free_loss_interval_history:
1238 dccp_li_hist_delete(ccid3_li_hist);
1239 ccid3_li_hist = NULL;
1241 dccp_tx_hist_delete(ccid3_tx_hist);
1242 ccid3_tx_hist = NULL;
1244 dccp_rx_hist_delete(ccid3_rx_hist);
1245 ccid3_rx_hist = NULL;
1248 module_init(ccid3_module_init);
1250 static __exit void ccid3_module_exit(void)
1252 ccid_unregister(&ccid3);
1254 if (ccid3_tx_hist != NULL) {
1255 dccp_tx_hist_delete(ccid3_tx_hist);
1256 ccid3_tx_hist = NULL;
1258 if (ccid3_rx_hist != NULL) {
1259 dccp_rx_hist_delete(ccid3_rx_hist);
1260 ccid3_rx_hist = NULL;
1262 if (ccid3_li_hist != NULL) {
1263 dccp_li_hist_delete(ccid3_li_hist);
1264 ccid3_li_hist = NULL;
1267 module_exit(ccid3_module_exit);
1269 MODULE_AUTHOR("Ian McDonald <ian.mcdonald@jandi.co.nz>, "
1270 "Arnaldo Carvalho de Melo <acme@ghostprotocols.net>");
1271 MODULE_DESCRIPTION("DCCP TFRC CCID3 CCID");
1272 MODULE_LICENSE("GPL");
1273 MODULE_ALIAS("net-dccp-ccid-3");