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.
38 #include "lib/packet_history.h"
39 #include "lib/loss_interval.h"
43 #ifdef CONFIG_IP_DCCP_CCID3_DEBUG
44 static int ccid3_debug;
45 #define ccid3_pr_debug(format, a...) DCCP_PR_DEBUG(ccid3_debug, format, ##a)
47 #define ccid3_pr_debug(format, a...)
50 static struct dccp_tx_hist *ccid3_tx_hist;
51 static struct dccp_rx_hist *ccid3_rx_hist;
52 static struct dccp_li_hist *ccid3_li_hist;
55 * Transmitter Half-Connection Routines
57 #ifdef CONFIG_IP_DCCP_CCID3_DEBUG
58 static const char *ccid3_tx_state_name(enum ccid3_hc_tx_states state)
60 static char *ccid3_state_names[] = {
61 [TFRC_SSTATE_NO_SENT] = "NO_SENT",
62 [TFRC_SSTATE_NO_FBACK] = "NO_FBACK",
63 [TFRC_SSTATE_FBACK] = "FBACK",
64 [TFRC_SSTATE_TERM] = "TERM",
67 return ccid3_state_names[state];
71 static void ccid3_hc_tx_set_state(struct sock *sk,
72 enum ccid3_hc_tx_states state)
74 struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
75 enum ccid3_hc_tx_states oldstate = hctx->ccid3hctx_state;
77 ccid3_pr_debug("%s(%p) %-8.8s -> %s\n",
78 dccp_role(sk), sk, ccid3_tx_state_name(oldstate),
79 ccid3_tx_state_name(state));
80 WARN_ON(state == oldstate);
81 hctx->ccid3hctx_state = state;
85 * Recalculate t_ipi and delta (should be called whenever X changes)
87 static inline void ccid3_update_send_interval(struct ccid3_hc_tx_sock *hctx)
89 /* Calculate new t_ipi = s / X_inst (X_inst is in 64 * bytes/second) */
90 hctx->ccid3hctx_t_ipi = scaled_div(hctx->ccid3hctx_s,
91 hctx->ccid3hctx_x >> 6);
93 /* Calculate new delta by delta = min(t_ipi / 2, t_gran / 2) */
94 hctx->ccid3hctx_delta = min_t(u32, hctx->ccid3hctx_t_ipi / 2,
95 TFRC_OPSYS_HALF_TIME_GRAN);
97 ccid3_pr_debug("t_ipi=%u, delta=%u, s=%u, X=%u\n",
98 hctx->ccid3hctx_t_ipi, hctx->ccid3hctx_delta,
99 hctx->ccid3hctx_s, (unsigned)(hctx->ccid3hctx_x >> 6));
105 * X_calc = calcX(s, R, p);
106 * X = max(min(X_calc, 2 * X_recv), s / t_mbi);
108 * If (now - tld >= R)
109 * X = max(min(2 * X, 2 * X_recv), s / R);
112 * Note: X and X_recv are both stored in units of 64 * bytes/second, to support
113 * fine-grained resolution of sending rates. This requires scaling by 2^6
114 * throughout the code. Only X_calc is unscaled (in bytes/second).
117 static void ccid3_hc_tx_update_x(struct sock *sk, struct timeval *now)
120 struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
121 const __u64 old_x = hctx->ccid3hctx_x;
123 if (hctx->ccid3hctx_p > 0) {
125 hctx->ccid3hctx_x = min(((__u64)hctx->ccid3hctx_x_calc) << 6,
126 hctx->ccid3hctx_x_recv * 2);
127 hctx->ccid3hctx_x = max(hctx->ccid3hctx_x,
128 (((__u64)hctx->ccid3hctx_s) << 6) /
131 } else if (timeval_delta(now, &hctx->ccid3hctx_t_ld) -
132 (suseconds_t)hctx->ccid3hctx_rtt >= 0) {
135 max(2 * min(hctx->ccid3hctx_x, hctx->ccid3hctx_x_recv),
136 scaled_div(((__u64)hctx->ccid3hctx_s) << 6,
137 hctx->ccid3hctx_rtt));
138 hctx->ccid3hctx_t_ld = *now;
141 if (hctx->ccid3hctx_x != old_x) {
142 ccid3_pr_debug("X_prev=%u, X_now=%u, X_calc=%u, "
143 "X_recv=%u\n", (unsigned)(old_x >> 6),
144 (unsigned)(hctx->ccid3hctx_x >> 6),
145 hctx->ccid3hctx_x_calc,
146 (unsigned)(hctx->ccid3hctx_x_recv >> 6));
148 ccid3_update_send_interval(hctx);
153 * Track the mean packet size `s' (cf. RFC 4342, 5.3 and RFC 3448, 4.1)
154 * @len: DCCP packet payload size in bytes
156 static inline void ccid3_hc_tx_update_s(struct ccid3_hc_tx_sock *hctx, int len)
158 const u16 old_s = hctx->ccid3hctx_s;
160 hctx->ccid3hctx_s = old_s == 0 ? len : (9 * old_s + len) / 10;
162 if (hctx->ccid3hctx_s != old_s)
163 ccid3_update_send_interval(hctx);
167 * Update Window Counter using the algorithm from [RFC 4342, 8.1].
168 * The algorithm is not applicable if RTT < 4 microseconds.
170 static inline void ccid3_hc_tx_update_win_count(struct ccid3_hc_tx_sock *hctx,
176 if (unlikely(hctx->ccid3hctx_rtt < 4)) /* avoid divide-by-zero */
179 delta = timeval_delta(now, &hctx->ccid3hctx_t_last_win_count);
180 DCCP_BUG_ON(delta < 0);
182 quarter_rtts = (u32)delta / (hctx->ccid3hctx_rtt / 4);
184 if (quarter_rtts > 0) {
185 hctx->ccid3hctx_t_last_win_count = *now;
186 hctx->ccid3hctx_last_win_count += min_t(u32, quarter_rtts, 5);
187 hctx->ccid3hctx_last_win_count &= 0xF; /* mod 16 */
189 ccid3_pr_debug("now at %#X\n", hctx->ccid3hctx_last_win_count);
193 static void ccid3_hc_tx_no_feedback_timer(unsigned long data)
195 struct sock *sk = (struct sock *)data;
196 struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
197 unsigned long t_nfb = USEC_PER_SEC / 5;
200 if (sock_owned_by_user(sk)) {
201 /* Try again later. */
202 /* XXX: set some sensible MIB */
206 ccid3_pr_debug("%s(%p, state=%s) - entry \n", dccp_role(sk), sk,
207 ccid3_tx_state_name(hctx->ccid3hctx_state));
209 switch (hctx->ccid3hctx_state) {
210 case TFRC_SSTATE_NO_FBACK:
211 /* RFC 3448, 4.4: Halve send rate directly */
212 hctx->ccid3hctx_x = max(hctx->ccid3hctx_x / 2,
213 (((__u64)hctx->ccid3hctx_s) << 6) /
216 ccid3_pr_debug("%s(%p, state=%s), updated tx rate to %u "
217 "bytes/s\n", dccp_role(sk), sk,
218 ccid3_tx_state_name(hctx->ccid3hctx_state),
219 (unsigned)(hctx->ccid3hctx_x >> 6));
220 /* The value of R is still undefined and so we can not recompute
221 * the timout value. Keep initial value as per [RFC 4342, 5]. */
222 t_nfb = TFRC_INITIAL_TIMEOUT;
223 ccid3_update_send_interval(hctx);
225 case TFRC_SSTATE_FBACK:
227 * Check if IDLE since last timeout and recv rate is less than
228 * 4 packets (in units of 64*bytes/sec) per RTT
230 if (!hctx->ccid3hctx_idle ||
231 (hctx->ccid3hctx_x_recv >= 4 *
232 scaled_div(((__u64)hctx->ccid3hctx_s) << 6,
233 hctx->ccid3hctx_rtt))) {
236 ccid3_pr_debug("%s(%p, state=%s), not idle\n",
238 ccid3_tx_state_name(hctx->ccid3hctx_state));
241 * Modify the cached value of X_recv [RFC 3448, 4.4]
243 * If (p == 0 || X_calc > 2 * X_recv)
244 * X_recv = max(X_recv / 2, s / (2 * t_mbi));
246 * X_recv = X_calc / 4;
248 * Note that X_recv is scaled by 2^6 while X_calc is not
250 BUG_ON(hctx->ccid3hctx_p && !hctx->ccid3hctx_x_calc);
252 if (hctx->ccid3hctx_p == 0 ||
253 (hctx->ccid3hctx_x_calc >
254 (hctx->ccid3hctx_x_recv >> 5))) {
256 hctx->ccid3hctx_x_recv =
257 max(hctx->ccid3hctx_x_recv / 2,
258 (((__u64)hctx->ccid3hctx_s) << 6) /
261 if (hctx->ccid3hctx_p == 0)
262 dccp_timestamp(sk, &now);
264 hctx->ccid3hctx_x_recv = hctx->ccid3hctx_x_calc;
265 hctx->ccid3hctx_x_recv <<= 4;
267 /* Now recalculate X [RFC 3448, 4.3, step (4)] */
268 ccid3_hc_tx_update_x(sk, &now);
271 * Schedule no feedback timer to expire in
272 * max(t_RTO, 2 * s/X) = max(t_RTO, 2 * t_ipi)
273 * See comments in packet_recv() regarding the value of t_RTO.
275 t_nfb = max(hctx->ccid3hctx_t_rto, 2 * hctx->ccid3hctx_t_ipi);
277 case TFRC_SSTATE_NO_SENT:
278 DCCP_BUG("%s(%p) - Illegal state NO_SENT", dccp_role(sk), sk);
280 case TFRC_SSTATE_TERM:
284 hctx->ccid3hctx_idle = 1;
287 sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer,
288 jiffies + usecs_to_jiffies(t_nfb));
296 * > 0: delay (in msecs) that should pass before actually sending
297 * = 0: can send immediately
298 * < 0: error condition; do not send packet
300 static int ccid3_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb)
302 struct dccp_sock *dp = dccp_sk(sk);
303 struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
307 BUG_ON(hctx == NULL);
310 * This function is called only for Data and DataAck packets. Sending
311 * zero-sized Data(Ack)s is theoretically possible, but for congestion
312 * control this case is pathological - ignore it.
314 if (unlikely(skb->len == 0))
317 dccp_timestamp(sk, &now);
319 switch (hctx->ccid3hctx_state) {
320 case TFRC_SSTATE_NO_SENT:
321 sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer,
323 usecs_to_jiffies(TFRC_INITIAL_TIMEOUT)));
324 hctx->ccid3hctx_last_win_count = 0;
325 hctx->ccid3hctx_t_last_win_count = now;
326 ccid3_hc_tx_set_state(sk, TFRC_SSTATE_NO_FBACK);
328 /* Set initial sending rate X/s to 1pps (X is scaled by 2^6) */
329 hctx->ccid3hctx_x = hctx->ccid3hctx_s = skb->len;
330 hctx->ccid3hctx_x <<= 6;
332 /* First timeout, according to [RFC 3448, 4.2], is 1 second */
333 hctx->ccid3hctx_t_ipi = USEC_PER_SEC;
334 /* Initial delta: minimum of 0.5 sec and t_gran/2 */
335 hctx->ccid3hctx_delta = TFRC_OPSYS_HALF_TIME_GRAN;
337 /* Set t_0 for initial packet */
338 hctx->ccid3hctx_t_nom = now;
340 case TFRC_SSTATE_NO_FBACK:
341 case TFRC_SSTATE_FBACK:
342 delay = timeval_delta(&hctx->ccid3hctx_t_nom, &now);
343 ccid3_pr_debug("delay=%ld\n", (long)delay);
345 * Scheduling of packet transmissions [RFC 3448, 4.6]
347 * if (t_now > t_nom - delta)
348 * // send the packet now
350 * // send the packet in (t_nom - t_now) milliseconds.
352 if (delay - (suseconds_t)hctx->ccid3hctx_delta >= 0)
353 return delay / 1000L;
355 ccid3_hc_tx_update_win_count(hctx, &now);
357 case TFRC_SSTATE_TERM:
358 DCCP_BUG("%s(%p) - Illegal state TERM", dccp_role(sk), sk);
362 /* prepare to send now (add options etc.) */
363 dp->dccps_hc_tx_insert_options = 1;
364 DCCP_SKB_CB(skb)->dccpd_ccval = hctx->ccid3hctx_last_win_count;
366 /* set the nominal send time for the next following packet */
367 timeval_add_usecs(&hctx->ccid3hctx_t_nom, hctx->ccid3hctx_t_ipi);
372 static void ccid3_hc_tx_packet_sent(struct sock *sk, int more,
375 struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
377 struct dccp_tx_hist_entry *packet;
379 BUG_ON(hctx == NULL);
381 ccid3_hc_tx_update_s(hctx, len);
383 packet = dccp_tx_hist_entry_new(ccid3_tx_hist, GFP_ATOMIC);
384 if (unlikely(packet == NULL)) {
385 DCCP_CRIT("packet history - out of memory!");
388 dccp_tx_hist_add_entry(&hctx->ccid3hctx_hist, packet);
390 dccp_timestamp(sk, &now);
391 packet->dccphtx_tstamp = now;
392 packet->dccphtx_seqno = dccp_sk(sk)->dccps_gss;
393 packet->dccphtx_rtt = hctx->ccid3hctx_rtt;
394 packet->dccphtx_sent = 1;
395 hctx->ccid3hctx_idle = 0;
398 static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb)
400 const struct dccp_sock *dp = dccp_sk(sk);
401 struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
402 struct ccid3_options_received *opt_recv;
403 struct dccp_tx_hist_entry *packet;
407 suseconds_t r_sample, t_elapsed;
409 BUG_ON(hctx == NULL);
411 /* we are only interested in ACKs */
412 if (!(DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_ACK ||
413 DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_DATAACK))
416 opt_recv = &hctx->ccid3hctx_options_received;
418 switch (hctx->ccid3hctx_state) {
419 case TFRC_SSTATE_NO_FBACK:
420 case TFRC_SSTATE_FBACK:
421 /* get packet from history to look up t_recvdata */
422 packet = dccp_tx_hist_find_entry(&hctx->ccid3hctx_hist,
423 DCCP_SKB_CB(skb)->dccpd_ack_seq);
424 if (unlikely(packet == NULL)) {
425 DCCP_WARN("%s(%p), seqno %llu(%s) doesn't exist "
426 "in history!\n", dccp_role(sk), sk,
427 (unsigned long long)DCCP_SKB_CB(skb)->dccpd_ack_seq,
428 dccp_packet_name(DCCP_SKB_CB(skb)->dccpd_type));
432 /* Update receive rate in units of 64 * bytes/second */
433 hctx->ccid3hctx_x_recv = opt_recv->ccid3or_receive_rate;
434 hctx->ccid3hctx_x_recv <<= 6;
436 /* Update loss event rate */
437 pinv = opt_recv->ccid3or_loss_event_rate;
438 if (pinv == ~0U || pinv == 0) /* see RFC 4342, 8.5 */
439 hctx->ccid3hctx_p = 0;
440 else /* can not exceed 100% */
441 hctx->ccid3hctx_p = 1000000 / pinv;
443 dccp_timestamp(sk, &now);
446 * Calculate new round trip sample as per [RFC 3448, 4.3] by
447 * R_sample = (now - t_recvdata) - t_elapsed
449 r_sample = timeval_delta(&now, &packet->dccphtx_tstamp);
450 t_elapsed = dp->dccps_options_received.dccpor_elapsed_time * 10;
452 DCCP_BUG_ON(r_sample < 0);
453 if (unlikely(r_sample <= t_elapsed))
454 DCCP_WARN("WARNING: r_sample=%dus <= t_elapsed=%dus\n",
455 (int)r_sample, (int)t_elapsed);
457 r_sample -= t_elapsed;
458 CCID3_RTT_SANITY_CHECK(r_sample);
460 /* Update RTT estimate by
461 * If (No feedback recv)
464 * R = q * R + (1 - q) * R_sample;
466 * q is a constant, RFC 3448 recomments 0.9
468 if (hctx->ccid3hctx_state == TFRC_SSTATE_NO_FBACK) {
470 * Larger Initial Windows [RFC 4342, sec. 5]
472 __u32 w_init = min(4 * dp->dccps_mss_cache,
473 max(2 * dp->dccps_mss_cache, 4380U));
474 hctx->ccid3hctx_rtt = r_sample;
475 hctx->ccid3hctx_x = scaled_div(w_init << 6, r_sample);
476 hctx->ccid3hctx_t_ld = now;
478 ccid3_update_send_interval(hctx);
480 ccid3_pr_debug("%s(%p), s=%u, MSS=%u, w_init=%u, "
481 "R_sample=%dus, X=%u\n", dccp_role(sk),
482 sk, hctx->ccid3hctx_s,
486 (unsigned)(hctx->ccid3hctx_x >> 6));
488 ccid3_hc_tx_set_state(sk, TFRC_SSTATE_FBACK);
490 hctx->ccid3hctx_rtt = (9 * hctx->ccid3hctx_rtt +
493 /* Update sending rate (step 4 of [RFC 3448, 4.3]) */
494 if (hctx->ccid3hctx_p > 0)
495 hctx->ccid3hctx_x_calc =
496 tfrc_calc_x(hctx->ccid3hctx_s,
499 ccid3_hc_tx_update_x(sk, &now);
501 ccid3_pr_debug("%s(%p), RTT=%uus (sample=%dus), s=%u, "
502 "p=%u, X_calc=%u, X_recv=%u, X=%u\n",
504 sk, hctx->ccid3hctx_rtt, (int)r_sample,
505 hctx->ccid3hctx_s, hctx->ccid3hctx_p,
506 hctx->ccid3hctx_x_calc,
507 (unsigned)(hctx->ccid3hctx_x_recv >> 6),
508 (unsigned)(hctx->ccid3hctx_x >> 6));
511 /* unschedule no feedback timer */
512 sk_stop_timer(sk, &hctx->ccid3hctx_no_feedback_timer);
514 /* remove all packets older than the one acked from history */
515 dccp_tx_hist_purge_older(ccid3_tx_hist,
516 &hctx->ccid3hctx_hist, packet);
518 * As we have calculated new ipi, delta, t_nom it is possible
519 * that we now can send a packet, so wake up dccp_wait_for_ccid
521 sk->sk_write_space(sk);
524 * Update timeout interval for the nofeedback timer.
525 * We use a configuration option to increase the lower bound.
526 * This can help avoid triggering the nofeedback timer too
527 * often ('spinning') on LANs with small RTTs.
529 hctx->ccid3hctx_t_rto = max_t(u32, 4 * hctx->ccid3hctx_rtt,
530 CONFIG_IP_DCCP_CCID3_RTO *
531 (USEC_PER_SEC/1000));
533 * Schedule no feedback timer to expire in
534 * max(t_RTO, 2 * s/X) = max(t_RTO, 2 * t_ipi)
536 t_nfb = max(hctx->ccid3hctx_t_rto, 2 * hctx->ccid3hctx_t_ipi);
538 ccid3_pr_debug("%s(%p), Scheduled no feedback timer to "
539 "expire in %lu jiffies (%luus)\n",
541 sk, usecs_to_jiffies(t_nfb), t_nfb);
543 sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer,
544 jiffies + usecs_to_jiffies(t_nfb));
547 hctx->ccid3hctx_idle = 1;
549 case TFRC_SSTATE_NO_SENT: /* fall through */
550 case TFRC_SSTATE_TERM: /* ignore feedback when closing */
555 static int ccid3_hc_tx_parse_options(struct sock *sk, unsigned char option,
556 unsigned char len, u16 idx,
557 unsigned char *value)
560 const struct dccp_sock *dp = dccp_sk(sk);
561 struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
562 struct ccid3_options_received *opt_recv;
564 BUG_ON(hctx == NULL);
566 opt_recv = &hctx->ccid3hctx_options_received;
568 if (opt_recv->ccid3or_seqno != dp->dccps_gsr) {
569 opt_recv->ccid3or_seqno = dp->dccps_gsr;
570 opt_recv->ccid3or_loss_event_rate = ~0;
571 opt_recv->ccid3or_loss_intervals_idx = 0;
572 opt_recv->ccid3or_loss_intervals_len = 0;
573 opt_recv->ccid3or_receive_rate = 0;
577 case TFRC_OPT_LOSS_EVENT_RATE:
578 if (unlikely(len != 4)) {
579 DCCP_WARN("%s(%p), invalid len %d "
580 "for TFRC_OPT_LOSS_EVENT_RATE\n",
581 dccp_role(sk), sk, len);
584 opt_recv->ccid3or_loss_event_rate =
585 ntohl(*(__be32 *)value);
586 ccid3_pr_debug("%s(%p), LOSS_EVENT_RATE=%u\n",
588 opt_recv->ccid3or_loss_event_rate);
591 case TFRC_OPT_LOSS_INTERVALS:
592 opt_recv->ccid3or_loss_intervals_idx = idx;
593 opt_recv->ccid3or_loss_intervals_len = len;
594 ccid3_pr_debug("%s(%p), LOSS_INTERVALS=(%u, %u)\n",
596 opt_recv->ccid3or_loss_intervals_idx,
597 opt_recv->ccid3or_loss_intervals_len);
599 case TFRC_OPT_RECEIVE_RATE:
600 if (unlikely(len != 4)) {
601 DCCP_WARN("%s(%p), invalid len %d "
602 "for TFRC_OPT_RECEIVE_RATE\n",
603 dccp_role(sk), sk, len);
606 opt_recv->ccid3or_receive_rate =
607 ntohl(*(__be32 *)value);
608 ccid3_pr_debug("%s(%p), RECEIVE_RATE=%u\n",
610 opt_recv->ccid3or_receive_rate);
618 static int ccid3_hc_tx_init(struct ccid *ccid, struct sock *sk)
620 struct ccid3_hc_tx_sock *hctx = ccid_priv(ccid);
622 hctx->ccid3hctx_s = 0;
623 hctx->ccid3hctx_rtt = 0;
624 hctx->ccid3hctx_state = TFRC_SSTATE_NO_SENT;
625 INIT_LIST_HEAD(&hctx->ccid3hctx_hist);
627 hctx->ccid3hctx_no_feedback_timer.function =
628 ccid3_hc_tx_no_feedback_timer;
629 hctx->ccid3hctx_no_feedback_timer.data = (unsigned long)sk;
630 init_timer(&hctx->ccid3hctx_no_feedback_timer);
635 static void ccid3_hc_tx_exit(struct sock *sk)
637 struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
639 BUG_ON(hctx == NULL);
641 ccid3_hc_tx_set_state(sk, TFRC_SSTATE_TERM);
642 sk_stop_timer(sk, &hctx->ccid3hctx_no_feedback_timer);
644 /* Empty packet history */
645 dccp_tx_hist_purge(ccid3_tx_hist, &hctx->ccid3hctx_hist);
648 static void ccid3_hc_tx_get_info(struct sock *sk, struct tcp_info *info)
650 const struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
652 /* Listen socks doesn't have a private CCID block */
653 if (sk->sk_state == DCCP_LISTEN)
656 BUG_ON(hctx == NULL);
658 info->tcpi_rto = hctx->ccid3hctx_t_rto;
659 info->tcpi_rtt = hctx->ccid3hctx_rtt;
662 static int ccid3_hc_tx_getsockopt(struct sock *sk, const int optname, int len,
663 u32 __user *optval, int __user *optlen)
665 const struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
668 /* Listen socks doesn't have a private CCID block */
669 if (sk->sk_state == DCCP_LISTEN)
673 case DCCP_SOCKOPT_CCID_TX_INFO:
674 if (len < sizeof(hctx->ccid3hctx_tfrc))
676 len = sizeof(hctx->ccid3hctx_tfrc);
677 val = &hctx->ccid3hctx_tfrc;
683 if (put_user(len, optlen) || copy_to_user(optval, val, len))
690 * Receiver Half-Connection Routines
692 #ifdef CONFIG_IP_DCCP_CCID3_DEBUG
693 static const char *ccid3_rx_state_name(enum ccid3_hc_rx_states state)
695 static char *ccid3_rx_state_names[] = {
696 [TFRC_RSTATE_NO_DATA] = "NO_DATA",
697 [TFRC_RSTATE_DATA] = "DATA",
698 [TFRC_RSTATE_TERM] = "TERM",
701 return ccid3_rx_state_names[state];
705 static void ccid3_hc_rx_set_state(struct sock *sk,
706 enum ccid3_hc_rx_states state)
708 struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
709 enum ccid3_hc_rx_states oldstate = hcrx->ccid3hcrx_state;
711 ccid3_pr_debug("%s(%p) %-8.8s -> %s\n",
712 dccp_role(sk), sk, ccid3_rx_state_name(oldstate),
713 ccid3_rx_state_name(state));
714 WARN_ON(state == oldstate);
715 hcrx->ccid3hcrx_state = state;
718 static inline void ccid3_hc_rx_update_s(struct ccid3_hc_rx_sock *hcrx, int len)
720 if (unlikely(len == 0)) /* don't update on empty packets (e.g. ACKs) */
721 ccid3_pr_debug("Packet payload length is 0 - not updating\n");
723 hcrx->ccid3hcrx_s = hcrx->ccid3hcrx_s == 0 ? len :
724 (9 * hcrx->ccid3hcrx_s + len) / 10;
727 static void ccid3_hc_rx_send_feedback(struct sock *sk)
729 struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
730 struct dccp_sock *dp = dccp_sk(sk);
731 struct dccp_rx_hist_entry *packet;
735 ccid3_pr_debug("%s(%p) - entry \n", dccp_role(sk), sk);
737 dccp_timestamp(sk, &now);
739 switch (hcrx->ccid3hcrx_state) {
740 case TFRC_RSTATE_NO_DATA:
741 hcrx->ccid3hcrx_x_recv = 0;
743 case TFRC_RSTATE_DATA:
744 delta = timeval_delta(&now,
745 &hcrx->ccid3hcrx_tstamp_last_feedback);
746 DCCP_BUG_ON(delta < 0);
747 hcrx->ccid3hcrx_x_recv =
748 scaled_div32(hcrx->ccid3hcrx_bytes_recv, delta);
750 case TFRC_RSTATE_TERM:
751 DCCP_BUG("%s(%p) - Illegal state TERM", dccp_role(sk), sk);
755 packet = dccp_rx_hist_find_data_packet(&hcrx->ccid3hcrx_hist);
756 if (unlikely(packet == NULL)) {
757 DCCP_WARN("%s(%p), no data packet in history!\n",
762 hcrx->ccid3hcrx_tstamp_last_feedback = now;
763 hcrx->ccid3hcrx_ccval_last_counter = packet->dccphrx_ccval;
764 hcrx->ccid3hcrx_bytes_recv = 0;
766 /* Elapsed time information [RFC 4340, 13.2] in units of 10 * usecs */
767 delta = timeval_delta(&now, &packet->dccphrx_tstamp);
768 DCCP_BUG_ON(delta < 0);
769 hcrx->ccid3hcrx_elapsed_time = delta / 10;
771 if (hcrx->ccid3hcrx_p == 0)
772 hcrx->ccid3hcrx_pinv = ~0U; /* see RFC 4342, 8.5 */
773 else if (hcrx->ccid3hcrx_p > 1000000) {
774 DCCP_WARN("p (%u) > 100%%\n", hcrx->ccid3hcrx_p);
775 hcrx->ccid3hcrx_pinv = 1; /* use 100% in this case */
777 hcrx->ccid3hcrx_pinv = 1000000 / hcrx->ccid3hcrx_p;
779 dp->dccps_hc_rx_insert_options = 1;
783 static int ccid3_hc_rx_insert_options(struct sock *sk, struct sk_buff *skb)
785 const struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
788 BUG_ON(hcrx == NULL);
790 if (!(sk->sk_state == DCCP_OPEN || sk->sk_state == DCCP_PARTOPEN))
793 DCCP_SKB_CB(skb)->dccpd_ccval = hcrx->ccid3hcrx_ccval_last_counter;
795 if (dccp_packet_without_ack(skb))
798 x_recv = htonl(hcrx->ccid3hcrx_x_recv);
799 pinv = htonl(hcrx->ccid3hcrx_pinv);
801 if ((hcrx->ccid3hcrx_elapsed_time != 0 &&
802 dccp_insert_option_elapsed_time(sk, skb,
803 hcrx->ccid3hcrx_elapsed_time)) ||
804 dccp_insert_option_timestamp(sk, skb) ||
805 dccp_insert_option(sk, skb, TFRC_OPT_LOSS_EVENT_RATE,
806 &pinv, sizeof(pinv)) ||
807 dccp_insert_option(sk, skb, TFRC_OPT_RECEIVE_RATE,
808 &x_recv, sizeof(x_recv)))
814 /* calculate first loss interval
816 * returns estimated loss interval in usecs */
818 static u32 ccid3_hc_rx_calc_first_li(struct sock *sk)
820 struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
821 struct dccp_rx_hist_entry *entry, *next, *tail = NULL;
823 suseconds_t rtt, delta;
824 struct timeval tstamp = { 0, };
830 list_for_each_entry_safe(entry, next, &hcrx->ccid3hcrx_hist,
832 if (dccp_rx_hist_entry_data_packet(entry)) {
837 tstamp = entry->dccphrx_tstamp;
838 win_count = entry->dccphrx_ccval;
842 interval = win_count - entry->dccphrx_ccval;
844 interval += TFRC_WIN_COUNT_LIMIT;
852 if (unlikely(step == 0)) {
853 DCCP_WARN("%s(%p), packet history has no data packets!\n",
858 if (unlikely(interval == 0)) {
859 DCCP_WARN("%s(%p), Could not find a win_count interval > 0."
860 "Defaulting to 1\n", dccp_role(sk), sk);
865 DCCP_CRIT("tail is null\n");
869 delta = timeval_delta(&tstamp, &tail->dccphrx_tstamp);
870 DCCP_BUG_ON(delta < 0);
872 rtt = delta * 4 / interval;
873 ccid3_pr_debug("%s(%p), approximated RTT to %dus\n",
874 dccp_role(sk), sk, (int)rtt);
877 * Determine the length of the first loss interval via inverse lookup.
878 * Assume that X_recv can be computed by the throughput equation
882 * Find some p such that f(p) = fval; return 1/p [RFC 3448, 6.3.1].
884 if (rtt == 0) { /* would result in divide-by-zero */
885 DCCP_WARN("RTT==0\n");
889 dccp_timestamp(sk, &tstamp);
890 delta = timeval_delta(&tstamp, &hcrx->ccid3hcrx_tstamp_last_feedback);
891 DCCP_BUG_ON(delta <= 0);
893 x_recv = scaled_div32(hcrx->ccid3hcrx_bytes_recv, delta);
894 if (x_recv == 0) { /* would also trigger divide-by-zero */
895 DCCP_WARN("X_recv==0\n");
896 if ((x_recv = hcrx->ccid3hcrx_x_recv) == 0) {
897 DCCP_BUG("stored value of X_recv is zero");
902 fval = scaled_div(hcrx->ccid3hcrx_s, rtt);
903 fval = scaled_div32(fval, x_recv);
904 p = tfrc_calc_x_reverse_lookup(fval);
906 ccid3_pr_debug("%s(%p), receive rate=%u bytes/s, implied "
907 "loss rate=%u\n", dccp_role(sk), sk, x_recv, p);
915 static void ccid3_hc_rx_update_li(struct sock *sk, u64 seq_loss, u8 win_loss)
917 struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
918 struct dccp_li_hist_entry *head;
921 if (list_empty(&hcrx->ccid3hcrx_li_hist)) {
922 if (!dccp_li_hist_interval_new(ccid3_li_hist,
923 &hcrx->ccid3hcrx_li_hist, seq_loss, win_loss))
926 head = list_entry(hcrx->ccid3hcrx_li_hist.next,
927 struct dccp_li_hist_entry, dccplih_node);
928 head->dccplih_interval = ccid3_hc_rx_calc_first_li(sk);
930 struct dccp_li_hist_entry *entry;
931 struct list_head *tail;
933 head = list_entry(hcrx->ccid3hcrx_li_hist.next,
934 struct dccp_li_hist_entry, dccplih_node);
935 /* FIXME win count check removed as was wrong */
936 /* should make this check with receive history */
937 /* and compare there as per section 10.2 of RFC4342 */
939 /* new loss event detected */
940 /* calculate last interval length */
941 seq_temp = dccp_delta_seqno(head->dccplih_seqno, seq_loss);
942 entry = dccp_li_hist_entry_new(ccid3_li_hist, GFP_ATOMIC);
945 DCCP_BUG("out of memory - can not allocate entry");
949 list_add(&entry->dccplih_node, &hcrx->ccid3hcrx_li_hist);
951 tail = hcrx->ccid3hcrx_li_hist.prev;
953 kmem_cache_free(ccid3_li_hist->dccplih_slab, tail);
955 /* Create the newest interval */
956 entry->dccplih_seqno = seq_loss;
957 entry->dccplih_interval = seq_temp;
958 entry->dccplih_win_count = win_loss;
962 static int ccid3_hc_rx_detect_loss(struct sock *sk,
963 struct dccp_rx_hist_entry *packet)
965 struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
966 struct dccp_rx_hist_entry *rx_hist =
967 dccp_rx_hist_head(&hcrx->ccid3hcrx_hist);
968 u64 seqno = packet->dccphrx_seqno;
974 tmp_seqno = hcrx->ccid3hcrx_seqno_nonloss;
977 follows48(packet->dccphrx_seqno, hcrx->ccid3hcrx_seqno_nonloss)) {
978 hcrx->ccid3hcrx_seqno_nonloss = seqno;
979 hcrx->ccid3hcrx_ccval_nonloss = packet->dccphrx_ccval;
984 while (dccp_delta_seqno(hcrx->ccid3hcrx_seqno_nonloss, seqno)
985 > TFRC_RECV_NUM_LATE_LOSS) {
987 ccid3_hc_rx_update_li(sk, hcrx->ccid3hcrx_seqno_nonloss,
988 hcrx->ccid3hcrx_ccval_nonloss);
989 tmp_seqno = hcrx->ccid3hcrx_seqno_nonloss;
990 dccp_inc_seqno(&tmp_seqno);
991 hcrx->ccid3hcrx_seqno_nonloss = tmp_seqno;
992 dccp_inc_seqno(&tmp_seqno);
993 while (dccp_rx_hist_find_entry(&hcrx->ccid3hcrx_hist,
994 tmp_seqno, &ccval)) {
995 hcrx->ccid3hcrx_seqno_nonloss = tmp_seqno;
996 hcrx->ccid3hcrx_ccval_nonloss = ccval;
997 dccp_inc_seqno(&tmp_seqno);
1001 /* FIXME - this code could be simplified with above while */
1002 /* but works at moment */
1003 if (follows48(packet->dccphrx_seqno, hcrx->ccid3hcrx_seqno_nonloss)) {
1004 hcrx->ccid3hcrx_seqno_nonloss = seqno;
1005 hcrx->ccid3hcrx_ccval_nonloss = packet->dccphrx_ccval;
1009 dccp_rx_hist_add_packet(ccid3_rx_hist, &hcrx->ccid3hcrx_hist,
1010 &hcrx->ccid3hcrx_li_hist, packet,
1011 hcrx->ccid3hcrx_seqno_nonloss);
1015 static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb)
1017 struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
1018 const struct dccp_options_received *opt_recv;
1019 struct dccp_rx_hist_entry *packet;
1021 u32 p_prev, rtt_prev;
1022 suseconds_t r_sample, t_elapsed;
1023 int loss, payload_size;
1025 BUG_ON(hcrx == NULL);
1027 opt_recv = &dccp_sk(sk)->dccps_options_received;
1029 switch (DCCP_SKB_CB(skb)->dccpd_type) {
1031 if (hcrx->ccid3hcrx_state == TFRC_RSTATE_NO_DATA)
1033 case DCCP_PKT_DATAACK:
1034 if (opt_recv->dccpor_timestamp_echo == 0)
1036 rtt_prev = hcrx->ccid3hcrx_rtt;
1037 dccp_timestamp(sk, &now);
1038 timeval_sub_usecs(&now, opt_recv->dccpor_timestamp_echo * 10);
1039 r_sample = timeval_usecs(&now);
1040 t_elapsed = opt_recv->dccpor_elapsed_time * 10;
1042 DCCP_BUG_ON(r_sample < 0);
1043 if (unlikely(r_sample <= t_elapsed))
1044 DCCP_WARN("r_sample=%ldus, t_elapsed=%ldus\n",
1045 (long)r_sample, (long)t_elapsed);
1047 r_sample -= t_elapsed;
1048 CCID3_RTT_SANITY_CHECK(r_sample);
1050 if (hcrx->ccid3hcrx_state == TFRC_RSTATE_NO_DATA)
1051 hcrx->ccid3hcrx_rtt = r_sample;
1053 hcrx->ccid3hcrx_rtt = (hcrx->ccid3hcrx_rtt * 9) / 10 +
1056 if (rtt_prev != hcrx->ccid3hcrx_rtt)
1057 ccid3_pr_debug("%s(%p), New RTT=%uus, elapsed time=%u\n",
1058 dccp_role(sk), sk, hcrx->ccid3hcrx_rtt,
1059 opt_recv->dccpor_elapsed_time);
1063 default: /* We're not interested in other packet types, move along */
1067 packet = dccp_rx_hist_entry_new(ccid3_rx_hist, sk, opt_recv->dccpor_ndp,
1069 if (unlikely(packet == NULL)) {
1070 DCCP_WARN("%s(%p), Not enough mem to add rx packet "
1071 "to history, consider it lost!\n", dccp_role(sk), sk);
1075 loss = ccid3_hc_rx_detect_loss(sk, packet);
1077 if (DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_ACK)
1080 payload_size = skb->len - dccp_hdr(skb)->dccph_doff * 4;
1081 ccid3_hc_rx_update_s(hcrx, payload_size);
1083 switch (hcrx->ccid3hcrx_state) {
1084 case TFRC_RSTATE_NO_DATA:
1085 ccid3_pr_debug("%s(%p, state=%s), skb=%p, sending initial "
1086 "feedback\n", dccp_role(sk), sk,
1087 dccp_state_name(sk->sk_state), skb);
1088 ccid3_hc_rx_send_feedback(sk);
1089 ccid3_hc_rx_set_state(sk, TFRC_RSTATE_DATA);
1091 case TFRC_RSTATE_DATA:
1092 hcrx->ccid3hcrx_bytes_recv += payload_size;
1096 dccp_timestamp(sk, &now);
1097 if ((timeval_delta(&now, &hcrx->ccid3hcrx_tstamp_last_ack) -
1098 (suseconds_t)hcrx->ccid3hcrx_rtt) >= 0) {
1099 hcrx->ccid3hcrx_tstamp_last_ack = now;
1100 ccid3_hc_rx_send_feedback(sk);
1103 case TFRC_RSTATE_TERM:
1104 DCCP_BUG("%s(%p) - Illegal state TERM", dccp_role(sk), sk);
1108 /* Dealing with packet loss */
1109 ccid3_pr_debug("%s(%p, state=%s), data loss! Reacting...\n",
1110 dccp_role(sk), sk, dccp_state_name(sk->sk_state));
1112 p_prev = hcrx->ccid3hcrx_p;
1114 /* Calculate loss event rate */
1115 if (!list_empty(&hcrx->ccid3hcrx_li_hist)) {
1116 u32 i_mean = dccp_li_hist_calc_i_mean(&hcrx->ccid3hcrx_li_hist);
1118 /* Scaling up by 1000000 as fixed decimal */
1120 hcrx->ccid3hcrx_p = 1000000 / i_mean;
1122 DCCP_BUG("empty loss history");
1124 if (hcrx->ccid3hcrx_p > p_prev) {
1125 ccid3_hc_rx_send_feedback(sk);
1130 static int ccid3_hc_rx_init(struct ccid *ccid, struct sock *sk)
1132 struct ccid3_hc_rx_sock *hcrx = ccid_priv(ccid);
1134 ccid3_pr_debug("entry\n");
1136 hcrx->ccid3hcrx_state = TFRC_RSTATE_NO_DATA;
1137 INIT_LIST_HEAD(&hcrx->ccid3hcrx_hist);
1138 INIT_LIST_HEAD(&hcrx->ccid3hcrx_li_hist);
1139 dccp_timestamp(sk, &hcrx->ccid3hcrx_tstamp_last_ack);
1140 hcrx->ccid3hcrx_tstamp_last_feedback = hcrx->ccid3hcrx_tstamp_last_ack;
1141 hcrx->ccid3hcrx_s = 0;
1142 hcrx->ccid3hcrx_rtt = 0;
1146 static void ccid3_hc_rx_exit(struct sock *sk)
1148 struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
1150 BUG_ON(hcrx == NULL);
1152 ccid3_hc_rx_set_state(sk, TFRC_RSTATE_TERM);
1154 /* Empty packet history */
1155 dccp_rx_hist_purge(ccid3_rx_hist, &hcrx->ccid3hcrx_hist);
1157 /* Empty loss interval history */
1158 dccp_li_hist_purge(ccid3_li_hist, &hcrx->ccid3hcrx_li_hist);
1161 static void ccid3_hc_rx_get_info(struct sock *sk, struct tcp_info *info)
1163 const struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
1165 /* Listen socks doesn't have a private CCID block */
1166 if (sk->sk_state == DCCP_LISTEN)
1169 BUG_ON(hcrx == NULL);
1171 info->tcpi_ca_state = hcrx->ccid3hcrx_state;
1172 info->tcpi_options |= TCPI_OPT_TIMESTAMPS;
1173 info->tcpi_rcv_rtt = hcrx->ccid3hcrx_rtt;
1176 static int ccid3_hc_rx_getsockopt(struct sock *sk, const int optname, int len,
1177 u32 __user *optval, int __user *optlen)
1179 const struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
1182 /* Listen socks doesn't have a private CCID block */
1183 if (sk->sk_state == DCCP_LISTEN)
1187 case DCCP_SOCKOPT_CCID_RX_INFO:
1188 if (len < sizeof(hcrx->ccid3hcrx_tfrc))
1190 len = sizeof(hcrx->ccid3hcrx_tfrc);
1191 val = &hcrx->ccid3hcrx_tfrc;
1194 return -ENOPROTOOPT;
1197 if (put_user(len, optlen) || copy_to_user(optval, val, len))
1203 static struct ccid_operations ccid3 = {
1204 .ccid_id = DCCPC_CCID3,
1205 .ccid_name = "ccid3",
1206 .ccid_owner = THIS_MODULE,
1207 .ccid_hc_tx_obj_size = sizeof(struct ccid3_hc_tx_sock),
1208 .ccid_hc_tx_init = ccid3_hc_tx_init,
1209 .ccid_hc_tx_exit = ccid3_hc_tx_exit,
1210 .ccid_hc_tx_send_packet = ccid3_hc_tx_send_packet,
1211 .ccid_hc_tx_packet_sent = ccid3_hc_tx_packet_sent,
1212 .ccid_hc_tx_packet_recv = ccid3_hc_tx_packet_recv,
1213 .ccid_hc_tx_parse_options = ccid3_hc_tx_parse_options,
1214 .ccid_hc_rx_obj_size = sizeof(struct ccid3_hc_rx_sock),
1215 .ccid_hc_rx_init = ccid3_hc_rx_init,
1216 .ccid_hc_rx_exit = ccid3_hc_rx_exit,
1217 .ccid_hc_rx_insert_options = ccid3_hc_rx_insert_options,
1218 .ccid_hc_rx_packet_recv = ccid3_hc_rx_packet_recv,
1219 .ccid_hc_rx_get_info = ccid3_hc_rx_get_info,
1220 .ccid_hc_tx_get_info = ccid3_hc_tx_get_info,
1221 .ccid_hc_rx_getsockopt = ccid3_hc_rx_getsockopt,
1222 .ccid_hc_tx_getsockopt = ccid3_hc_tx_getsockopt,
1225 #ifdef CONFIG_IP_DCCP_CCID3_DEBUG
1226 module_param(ccid3_debug, int, 0444);
1227 MODULE_PARM_DESC(ccid3_debug, "Enable debug messages");
1230 static __init int ccid3_module_init(void)
1234 ccid3_rx_hist = dccp_rx_hist_new("ccid3");
1235 if (ccid3_rx_hist == NULL)
1238 ccid3_tx_hist = dccp_tx_hist_new("ccid3");
1239 if (ccid3_tx_hist == NULL)
1242 ccid3_li_hist = dccp_li_hist_new("ccid3");
1243 if (ccid3_li_hist == NULL)
1246 rc = ccid_register(&ccid3);
1248 goto out_free_loss_interval_history;
1252 out_free_loss_interval_history:
1253 dccp_li_hist_delete(ccid3_li_hist);
1254 ccid3_li_hist = NULL;
1256 dccp_tx_hist_delete(ccid3_tx_hist);
1257 ccid3_tx_hist = NULL;
1259 dccp_rx_hist_delete(ccid3_rx_hist);
1260 ccid3_rx_hist = NULL;
1263 module_init(ccid3_module_init);
1265 static __exit void ccid3_module_exit(void)
1267 ccid_unregister(&ccid3);
1269 if (ccid3_tx_hist != NULL) {
1270 dccp_tx_hist_delete(ccid3_tx_hist);
1271 ccid3_tx_hist = NULL;
1273 if (ccid3_rx_hist != NULL) {
1274 dccp_rx_hist_delete(ccid3_rx_hist);
1275 ccid3_rx_hist = NULL;
1277 if (ccid3_li_hist != NULL) {
1278 dccp_li_hist_delete(ccid3_li_hist);
1279 ccid3_li_hist = NULL;
1282 module_exit(ccid3_module_exit);
1284 MODULE_AUTHOR("Ian McDonald <ian.mcdonald@jandi.co.nz>, "
1285 "Arnaldo Carvalho de Melo <acme@ghostprotocols.net>");
1286 MODULE_DESCRIPTION("DCCP TFRC CCID3 CCID");
1287 MODULE_LICENSE("GPL");
1288 MODULE_ALIAS("net-dccp-ccid-3");