2 * net/dccp/ccids/ccid3.c
4 * Copyright (c) 2005 The University of Waikato, Hamilton, New Zealand.
5 * Copyright (c) 2005 Ian McDonald <iam4@cs.waikato.ac.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.
37 #include <linux/config.h>
40 #include "lib/packet_history.h"
41 #include "lib/loss_interval.h"
46 * Reason for maths here is to avoid 32 bit overflow when a is big.
47 * With this we get close to the limit.
49 static inline u32 usecs_div(const u32 a, const u32 b)
51 const u32 div = a < (UINT_MAX / (USEC_PER_SEC / 10)) ? 10 :
52 a < (UINT_MAX / (USEC_PER_SEC / 50)) ? 50 :
53 a < (UINT_MAX / (USEC_PER_SEC / 100)) ? 100 :
54 a < (UINT_MAX / (USEC_PER_SEC / 500)) ? 500 :
55 a < (UINT_MAX / (USEC_PER_SEC / 1000)) ? 1000 :
56 a < (UINT_MAX / (USEC_PER_SEC / 5000)) ? 5000 :
57 a < (UINT_MAX / (USEC_PER_SEC / 10000)) ? 10000 :
58 a < (UINT_MAX / (USEC_PER_SEC / 50000)) ? 50000 :
60 const u32 tmp = a * (USEC_PER_SEC / div);
61 return (b >= 2 * div) ? tmp / (b / div) : tmp;
64 static int ccid3_debug;
67 #define ccid3_pr_debug(format, a...) \
68 do { if (ccid3_debug) \
69 printk(KERN_DEBUG "%s: " format, __FUNCTION__, ##a); \
72 #define ccid3_pr_debug(format, a...)
75 static struct dccp_tx_hist *ccid3_tx_hist;
76 static struct dccp_rx_hist *ccid3_rx_hist;
77 static struct dccp_li_hist *ccid3_li_hist;
79 static int ccid3_init(struct sock *sk)
81 ccid3_pr_debug("%s, sk=%p\n", dccp_role(sk), sk);
85 static void ccid3_exit(struct sock *sk)
87 ccid3_pr_debug("%s, sk=%p\n", dccp_role(sk), sk);
90 /* TFRC sender states */
91 enum ccid3_hc_tx_states {
92 TFRC_SSTATE_NO_SENT = 1,
99 static const char *ccid3_tx_state_name(enum ccid3_hc_tx_states state)
101 static char *ccid3_state_names[] = {
102 [TFRC_SSTATE_NO_SENT] = "NO_SENT",
103 [TFRC_SSTATE_NO_FBACK] = "NO_FBACK",
104 [TFRC_SSTATE_FBACK] = "FBACK",
105 [TFRC_SSTATE_TERM] = "TERM",
108 return ccid3_state_names[state];
112 static inline void ccid3_hc_tx_set_state(struct sock *sk,
113 enum ccid3_hc_tx_states state)
115 struct dccp_sock *dp = dccp_sk(sk);
116 struct ccid3_hc_tx_sock *hctx = dp->dccps_hc_tx_ccid_private;
117 enum ccid3_hc_tx_states oldstate = hctx->ccid3hctx_state;
119 ccid3_pr_debug("%s(%p) %-8.8s -> %s\n",
120 dccp_role(sk), sk, ccid3_tx_state_name(oldstate),
121 ccid3_tx_state_name(state));
122 WARN_ON(state == oldstate);
123 hctx->ccid3hctx_state = state;
126 /* Calculate new t_ipi (inter packet interval) by t_ipi = s / X_inst */
127 static inline void ccid3_calc_new_t_ipi(struct ccid3_hc_tx_sock *hctx)
130 * If no feedback spec says t_ipi is 1 second (set elsewhere and then
131 * doubles after every no feedback timer (separate function)
133 if (hctx->ccid3hctx_state != TFRC_SSTATE_NO_FBACK)
134 hctx->ccid3hctx_t_ipi = usecs_div(hctx->ccid3hctx_s,
138 /* Calculate new delta by delta = min(t_ipi / 2, t_gran / 2) */
139 static inline void ccid3_calc_new_delta(struct ccid3_hc_tx_sock *hctx)
141 hctx->ccid3hctx_delta = min_t(u32, hctx->ccid3hctx_t_ipi / 2,
142 TFRC_OPSYS_HALF_TIME_GRAN);
148 * x_calc = calcX(s, R, p);
149 * X = max(min(X_calc, 2 * X_recv), s / t_mbi);
151 * If (now - tld >= R)
152 * X = max(min(2 * X, 2 * X_recv), s / R);
155 static void ccid3_hc_tx_update_x(struct sock *sk)
157 struct dccp_sock *dp = dccp_sk(sk);
158 struct ccid3_hc_tx_sock *hctx = dp->dccps_hc_tx_ccid_private;
160 /* To avoid large error in calcX */
161 if (hctx->ccid3hctx_p >= TFRC_SMALLEST_P) {
162 hctx->ccid3hctx_x_calc = tfrc_calc_x(hctx->ccid3hctx_s,
165 hctx->ccid3hctx_x = max_t(u32, min_t(u32, hctx->ccid3hctx_x_calc,
166 2 * hctx->ccid3hctx_x_recv),
168 TFRC_MAX_BACK_OFF_TIME));
172 do_gettimeofday(&now);
173 if (timeval_delta(&now, &hctx->ccid3hctx_t_ld) >=
174 hctx->ccid3hctx_rtt) {
175 hctx->ccid3hctx_x = max_t(u32, min_t(u32, hctx->ccid3hctx_x_recv,
176 hctx->ccid3hctx_x) * 2,
177 usecs_div(hctx->ccid3hctx_s,
178 hctx->ccid3hctx_rtt));
179 hctx->ccid3hctx_t_ld = now;
184 static void ccid3_hc_tx_no_feedback_timer(unsigned long data)
186 struct sock *sk = (struct sock *)data;
187 struct dccp_sock *dp = dccp_sk(sk);
188 unsigned long next_tmout = 0;
189 struct ccid3_hc_tx_sock *hctx = dp->dccps_hc_tx_ccid_private;
192 if (sock_owned_by_user(sk)) {
193 /* Try again later. */
194 /* XXX: set some sensible MIB */
195 sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer,
200 ccid3_pr_debug("%s, sk=%p, state=%s\n", dccp_role(sk), sk,
201 ccid3_tx_state_name(hctx->ccid3hctx_state));
203 switch (hctx->ccid3hctx_state) {
204 case TFRC_SSTATE_TERM:
206 case TFRC_SSTATE_NO_FBACK:
207 /* Halve send rate */
208 hctx->ccid3hctx_x /= 2;
209 if (hctx->ccid3hctx_x < (hctx->ccid3hctx_s /
210 TFRC_MAX_BACK_OFF_TIME))
211 hctx->ccid3hctx_x = (hctx->ccid3hctx_s /
212 TFRC_MAX_BACK_OFF_TIME);
214 ccid3_pr_debug("%s, sk=%p, state=%s, updated tx rate to %d "
217 ccid3_tx_state_name(hctx->ccid3hctx_state),
219 next_tmout = max_t(u32, 2 * usecs_div(hctx->ccid3hctx_s,
221 TFRC_INITIAL_TIMEOUT);
223 * FIXME - not sure above calculation is correct. See section
224 * 5 of CCID3 11 should adjust tx_t_ipi and double that to
228 case TFRC_SSTATE_FBACK:
230 * Check if IDLE since last timeout and recv rate is less than
233 if (!hctx->ccid3hctx_idle ||
234 (hctx->ccid3hctx_x_recv >=
235 4 * usecs_div(hctx->ccid3hctx_s, hctx->ccid3hctx_rtt))) {
236 ccid3_pr_debug("%s, sk=%p, state=%s, not idle\n",
238 ccid3_tx_state_name(hctx->ccid3hctx_state));
239 /* Halve sending rate */
241 /* If (X_calc > 2 * X_recv)
242 * X_recv = max(X_recv / 2, s / (2 * t_mbi));
244 * X_recv = X_calc / 4;
246 BUG_ON(hctx->ccid3hctx_p >= TFRC_SMALLEST_P &&
247 hctx->ccid3hctx_x_calc == 0);
249 /* check also if p is zero -> x_calc is infinity? */
250 if (hctx->ccid3hctx_p < TFRC_SMALLEST_P ||
251 hctx->ccid3hctx_x_calc > 2 * hctx->ccid3hctx_x_recv)
252 hctx->ccid3hctx_x_recv = max_t(u32, hctx->ccid3hctx_x_recv / 2,
253 hctx->ccid3hctx_s / (2 * TFRC_MAX_BACK_OFF_TIME));
255 hctx->ccid3hctx_x_recv = hctx->ccid3hctx_x_calc / 4;
257 /* Update sending rate */
258 ccid3_hc_tx_update_x(sk);
261 * Schedule no feedback timer to expire in
262 * max(4 * R, 2 * s / X)
264 next_tmout = max_t(u32, hctx->ccid3hctx_t_rto,
265 2 * usecs_div(hctx->ccid3hctx_s,
269 printk(KERN_CRIT "%s: %s, sk=%p, Illegal state (%d)!\n",
270 __FUNCTION__, dccp_role(sk), sk, hctx->ccid3hctx_state);
275 sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer,
276 jiffies + max_t(u32, 1, usecs_to_jiffies(next_tmout)));
277 hctx->ccid3hctx_idle = 1;
283 static int ccid3_hc_tx_send_packet(struct sock *sk,
284 struct sk_buff *skb, int len)
286 struct dccp_sock *dp = dccp_sk(sk);
287 struct ccid3_hc_tx_sock *hctx = dp->dccps_hc_tx_ccid_private;
288 struct dccp_tx_hist_entry *new_packet;
293 /* Check if pure ACK or Terminating*/
296 * XXX: We only call this function for DATA and DATAACK, on, these
297 * packets can have zero length, but why the comment about "pure ACK"?
299 if (hctx == NULL || len == 0 ||
300 hctx->ccid3hctx_state == TFRC_SSTATE_TERM)
303 /* See if last packet allocated was not sent */
304 new_packet = dccp_tx_hist_head(&hctx->ccid3hctx_hist);
305 if (new_packet == NULL || new_packet->dccphtx_sent) {
306 new_packet = dccp_tx_hist_entry_new(ccid3_tx_hist,
310 if (new_packet == NULL) {
311 ccid3_pr_debug("%s, sk=%p, not enough mem to add "
312 "to history, send refused\n",
317 dccp_tx_hist_add_entry(&hctx->ccid3hctx_hist, new_packet);
320 do_gettimeofday(&now);
322 switch (hctx->ccid3hctx_state) {
323 case TFRC_SSTATE_NO_SENT:
324 ccid3_pr_debug("%s, sk=%p, first packet(%llu)\n",
325 dccp_role(sk), sk, dp->dccps_gss);
327 hctx->ccid3hctx_no_feedback_timer.function = ccid3_hc_tx_no_feedback_timer;
328 hctx->ccid3hctx_no_feedback_timer.data = (unsigned long)sk;
329 sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer,
330 jiffies + usecs_to_jiffies(TFRC_INITIAL_TIMEOUT));
331 hctx->ccid3hctx_last_win_count = 0;
332 hctx->ccid3hctx_t_last_win_count = now;
333 ccid3_hc_tx_set_state(sk, TFRC_SSTATE_NO_FBACK);
334 hctx->ccid3hctx_t_ipi = TFRC_INITIAL_TIMEOUT;
336 /* Set nominal send time for initial packet */
337 hctx->ccid3hctx_t_nom = now;
338 timeval_add_usecs(&hctx->ccid3hctx_t_nom,
339 hctx->ccid3hctx_t_ipi);
340 ccid3_calc_new_delta(hctx);
343 case TFRC_SSTATE_NO_FBACK:
344 case TFRC_SSTATE_FBACK:
345 delay = (timeval_delta(&now, &hctx->ccid3hctx_t_nom) -
346 hctx->ccid3hctx_delta);
347 ccid3_pr_debug("send_packet delay=%ld\n", delay);
349 /* divide by -1000 is to convert to ms and get sign right */
350 rc = delay > 0 ? delay : 0;
353 printk(KERN_CRIT "%s: %s, sk=%p, Illegal state (%d)!\n",
354 __FUNCTION__, dccp_role(sk), sk, hctx->ccid3hctx_state);
360 /* Can we send? if so add options and add to packet history */
362 dp->dccps_hc_tx_insert_options = 1;
363 new_packet->dccphtx_ccval =
364 DCCP_SKB_CB(skb)->dccpd_ccval =
365 hctx->ccid3hctx_last_win_count;
371 static void ccid3_hc_tx_packet_sent(struct sock *sk, int more, int len)
373 struct dccp_sock *dp = dccp_sk(sk);
374 struct ccid3_hc_tx_sock *hctx = dp->dccps_hc_tx_ccid_private;
377 BUG_ON(hctx == NULL);
379 if (hctx->ccid3hctx_state == TFRC_SSTATE_TERM) {
380 ccid3_pr_debug("%s, sk=%p, while state is TFRC_SSTATE_TERM!\n",
385 do_gettimeofday(&now);
387 /* check if we have sent a data packet */
389 unsigned long quarter_rtt;
390 struct dccp_tx_hist_entry *packet;
392 packet = dccp_tx_hist_head(&hctx->ccid3hctx_hist);
393 if (packet == NULL) {
394 printk(KERN_CRIT "%s: packet doesn't exists in "
395 "history!\n", __FUNCTION__);
398 if (packet->dccphtx_sent) {
399 printk(KERN_CRIT "%s: no unsent packet in history!\n",
403 packet->dccphtx_tstamp = now;
404 packet->dccphtx_seqno = dp->dccps_gss;
406 * Check if win_count have changed
407 * Algorithm in "8.1. Window Counter Valuer" in
408 * draft-ietf-dccp-ccid3-11.txt
410 quarter_rtt = timeval_delta(&now, &hctx->ccid3hctx_t_last_win_count);
411 if (likely(hctx->ccid3hctx_rtt > 8))
412 quarter_rtt /= hctx->ccid3hctx_rtt / 4;
414 if (quarter_rtt > 0) {
415 hctx->ccid3hctx_t_last_win_count = now;
416 hctx->ccid3hctx_last_win_count = (hctx->ccid3hctx_last_win_count +
417 min_t(unsigned long, quarter_rtt, 5)) % 16;
418 ccid3_pr_debug("%s, sk=%p, window changed from "
421 packet->dccphtx_ccval,
422 hctx->ccid3hctx_last_win_count);
425 hctx->ccid3hctx_idle = 0;
426 packet->dccphtx_rtt = hctx->ccid3hctx_rtt;
427 packet->dccphtx_sent = 1;
429 ccid3_pr_debug("%s, sk=%p, seqno=%llu NOT inserted!\n",
430 dccp_role(sk), sk, dp->dccps_gss);
432 switch (hctx->ccid3hctx_state) {
433 case TFRC_SSTATE_NO_SENT:
434 /* if first wasn't pure ack */
436 printk(KERN_CRIT "%s: %s, First packet sent is noted "
437 "as a data packet\n",
438 __FUNCTION__, dccp_role(sk));
440 case TFRC_SSTATE_NO_FBACK:
441 case TFRC_SSTATE_FBACK:
443 hctx->ccid3hctx_t_nom = now;
444 ccid3_calc_new_t_ipi(hctx);
445 ccid3_calc_new_delta(hctx);
446 timeval_add_usecs(&hctx->ccid3hctx_t_nom,
447 hctx->ccid3hctx_t_ipi);
451 printk(KERN_CRIT "%s: %s, sk=%p, Illegal state (%d)!\n",
452 __FUNCTION__, dccp_role(sk), sk, hctx->ccid3hctx_state);
458 static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb)
460 struct dccp_sock *dp = dccp_sk(sk);
461 struct ccid3_hc_tx_sock *hctx = dp->dccps_hc_tx_ccid_private;
462 struct ccid3_options_received *opt_recv;
463 struct dccp_tx_hist_entry *packet;
464 unsigned long next_tmout;
473 if (hctx->ccid3hctx_state == TFRC_SSTATE_TERM) {
474 ccid3_pr_debug("%s, sk=%p, received a packet when "
475 "terminating!\n", dccp_role(sk), sk);
479 /* we are only interested in ACKs */
480 if (!(DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_ACK ||
481 DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_DATAACK))
484 opt_recv = &hctx->ccid3hctx_options_received;
486 t_elapsed = dp->dccps_options_received.dccpor_elapsed_time;
487 x_recv = opt_recv->ccid3or_receive_rate;
488 pinv = opt_recv->ccid3or_loss_event_rate;
490 switch (hctx->ccid3hctx_state) {
491 case TFRC_SSTATE_NO_SENT:
492 /* FIXME: what to do here? */
494 case TFRC_SSTATE_NO_FBACK:
495 case TFRC_SSTATE_FBACK:
496 /* Calculate new round trip sample by
497 * R_sample = (now - t_recvdata) - t_delay */
498 /* get t_recvdata from history */
499 packet = dccp_tx_hist_find_entry(&hctx->ccid3hctx_hist,
500 DCCP_SKB_CB(skb)->dccpd_ack_seq);
501 if (packet == NULL) {
502 ccid3_pr_debug("%s, sk=%p, seqno %llu(%s) does't "
503 "exist in history!\n",
505 DCCP_SKB_CB(skb)->dccpd_ack_seq,
506 dccp_packet_name(DCCP_SKB_CB(skb)->dccpd_type));
511 r_sample = timeval_now_delta(&packet->dccphtx_tstamp);
513 // r_sample -= usecs_to_jiffies(t_elapsed * 10);
515 /* Update RTT estimate by
516 * If (No feedback recv)
519 * R = q * R + (1 - q) * R_sample;
521 * q is a constant, RFC 3448 recomments 0.9
523 if (hctx->ccid3hctx_state == TFRC_SSTATE_NO_FBACK) {
524 ccid3_hc_tx_set_state(sk, TFRC_SSTATE_FBACK);
525 hctx->ccid3hctx_rtt = r_sample;
527 hctx->ccid3hctx_rtt = (hctx->ccid3hctx_rtt * 9) / 10 +
530 ccid3_pr_debug("%s, sk=%p, New RTT estimate=%uus, "
531 "r_sample=%us\n", dccp_role(sk), sk,
532 hctx->ccid3hctx_rtt, r_sample);
534 /* Update timeout interval */
535 hctx->ccid3hctx_t_rto = max_t(u32, 4 * hctx->ccid3hctx_rtt,
538 /* Update receive rate */
539 hctx->ccid3hctx_x_recv = x_recv;/* X_recv in bytes per sec */
541 /* Update loss event rate */
542 if (pinv == ~0 || pinv == 0)
543 hctx->ccid3hctx_p = 0;
545 hctx->ccid3hctx_p = 1000000 / pinv;
547 if (hctx->ccid3hctx_p < TFRC_SMALLEST_P) {
548 hctx->ccid3hctx_p = TFRC_SMALLEST_P;
549 ccid3_pr_debug("%s, sk=%p, Smallest p used!\n",
554 /* unschedule no feedback timer */
555 sk_stop_timer(sk, &hctx->ccid3hctx_no_feedback_timer);
557 /* Update sending rate */
558 ccid3_hc_tx_update_x(sk);
560 /* Update next send time */
561 timeval_sub_usecs(&hctx->ccid3hctx_t_nom,
562 hctx->ccid3hctx_t_ipi);
563 ccid3_calc_new_t_ipi(hctx);
564 timeval_add_usecs(&hctx->ccid3hctx_t_nom,
565 hctx->ccid3hctx_t_ipi);
566 ccid3_calc_new_delta(hctx);
568 /* remove all packets older than the one acked from history */
569 dccp_tx_hist_purge_older(ccid3_tx_hist,
570 &hctx->ccid3hctx_hist, packet);
572 * As we have calculated new ipi, delta, t_nom it is possible that
573 * we now can send a packet, so wake up dccp_wait_for_ccids.
575 sk->sk_write_space(sk);
578 * Schedule no feedback timer to expire in
579 * max(4 * R, 2 * s / X)
581 next_tmout = max(hctx->ccid3hctx_t_rto,
582 2 * usecs_div(hctx->ccid3hctx_s,
585 ccid3_pr_debug("%s, sk=%p, Scheduled no feedback timer to "
586 "expire in %lu jiffies (%luus)\n",
588 usecs_to_jiffies(next_tmout), next_tmout);
590 sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer,
591 jiffies + max_t(u32, 1, usecs_to_jiffies(next_tmout)));
594 hctx->ccid3hctx_idle = 1;
597 printk(KERN_CRIT "%s: %s, sk=%p, Illegal state (%d)!\n",
598 __FUNCTION__, dccp_role(sk), sk, hctx->ccid3hctx_state);
604 static void ccid3_hc_tx_insert_options(struct sock *sk, struct sk_buff *skb)
606 const struct dccp_sock *dp = dccp_sk(sk);
607 struct ccid3_hc_tx_sock *hctx = dp->dccps_hc_tx_ccid_private;
609 if (hctx == NULL || !(sk->sk_state == DCCP_OPEN ||
610 sk->sk_state == DCCP_PARTOPEN))
613 DCCP_SKB_CB(skb)->dccpd_ccval = hctx->ccid3hctx_last_win_count;
616 static int ccid3_hc_tx_parse_options(struct sock *sk, unsigned char option,
617 unsigned char len, u16 idx,
618 unsigned char *value)
621 struct dccp_sock *dp = dccp_sk(sk);
622 struct ccid3_hc_tx_sock *hctx = dp->dccps_hc_tx_ccid_private;
623 struct ccid3_options_received *opt_recv;
628 opt_recv = &hctx->ccid3hctx_options_received;
630 if (opt_recv->ccid3or_seqno != dp->dccps_gsr) {
631 opt_recv->ccid3or_seqno = dp->dccps_gsr;
632 opt_recv->ccid3or_loss_event_rate = ~0;
633 opt_recv->ccid3or_loss_intervals_idx = 0;
634 opt_recv->ccid3or_loss_intervals_len = 0;
635 opt_recv->ccid3or_receive_rate = 0;
639 case TFRC_OPT_LOSS_EVENT_RATE:
641 ccid3_pr_debug("%s, sk=%p, invalid len for "
642 "TFRC_OPT_LOSS_EVENT_RATE\n",
646 opt_recv->ccid3or_loss_event_rate = ntohl(*(u32 *)value);
647 ccid3_pr_debug("%s, sk=%p, LOSS_EVENT_RATE=%u\n",
649 opt_recv->ccid3or_loss_event_rate);
652 case TFRC_OPT_LOSS_INTERVALS:
653 opt_recv->ccid3or_loss_intervals_idx = idx;
654 opt_recv->ccid3or_loss_intervals_len = len;
655 ccid3_pr_debug("%s, sk=%p, LOSS_INTERVALS=(%u, %u)\n",
657 opt_recv->ccid3or_loss_intervals_idx,
658 opt_recv->ccid3or_loss_intervals_len);
660 case TFRC_OPT_RECEIVE_RATE:
662 ccid3_pr_debug("%s, sk=%p, invalid len for "
663 "TFRC_OPT_RECEIVE_RATE\n",
667 opt_recv->ccid3or_receive_rate = ntohl(*(u32 *)value);
668 ccid3_pr_debug("%s, sk=%p, RECEIVE_RATE=%u\n",
670 opt_recv->ccid3or_receive_rate);
678 static int ccid3_hc_tx_init(struct sock *sk)
680 struct dccp_sock *dp = dccp_sk(sk);
681 struct ccid3_hc_tx_sock *hctx;
683 ccid3_pr_debug("%s, sk=%p\n", dccp_role(sk), sk);
685 hctx = dp->dccps_hc_tx_ccid_private = kmalloc(sizeof(*hctx),
690 memset(hctx, 0, sizeof(*hctx));
692 if (dp->dccps_packet_size >= TFRC_MIN_PACKET_SIZE &&
693 dp->dccps_packet_size <= TFRC_MAX_PACKET_SIZE)
694 hctx->ccid3hctx_s = dp->dccps_packet_size;
696 hctx->ccid3hctx_s = TFRC_STD_PACKET_SIZE;
698 /* Set transmission rate to 1 packet per second */
699 hctx->ccid3hctx_x = hctx->ccid3hctx_s;
700 hctx->ccid3hctx_t_rto = USEC_PER_SEC;
701 hctx->ccid3hctx_state = TFRC_SSTATE_NO_SENT;
702 INIT_LIST_HEAD(&hctx->ccid3hctx_hist);
703 init_timer(&hctx->ccid3hctx_no_feedback_timer);
708 static void ccid3_hc_tx_exit(struct sock *sk)
710 struct dccp_sock *dp = dccp_sk(sk);
711 struct ccid3_hc_tx_sock *hctx = dp->dccps_hc_tx_ccid_private;
713 ccid3_pr_debug("%s, sk=%p\n", dccp_role(sk), sk);
714 BUG_ON(hctx == NULL);
716 ccid3_hc_tx_set_state(sk, TFRC_SSTATE_TERM);
717 sk_stop_timer(sk, &hctx->ccid3hctx_no_feedback_timer);
719 /* Empty packet history */
720 dccp_tx_hist_purge(ccid3_tx_hist, &hctx->ccid3hctx_hist);
722 kfree(dp->dccps_hc_tx_ccid_private);
723 dp->dccps_hc_tx_ccid_private = NULL;
727 * RX Half Connection methods
730 /* TFRC receiver states */
731 enum ccid3_hc_rx_states {
732 TFRC_RSTATE_NO_DATA = 1,
734 TFRC_RSTATE_TERM = 127,
738 static const char *ccid3_rx_state_name(enum ccid3_hc_rx_states state)
740 static char *ccid3_rx_state_names[] = {
741 [TFRC_RSTATE_NO_DATA] = "NO_DATA",
742 [TFRC_RSTATE_DATA] = "DATA",
743 [TFRC_RSTATE_TERM] = "TERM",
746 return ccid3_rx_state_names[state];
750 static inline void ccid3_hc_rx_set_state(struct sock *sk,
751 enum ccid3_hc_rx_states state)
753 struct dccp_sock *dp = dccp_sk(sk);
754 struct ccid3_hc_rx_sock *hcrx = dp->dccps_hc_rx_ccid_private;
755 enum ccid3_hc_rx_states oldstate = hcrx->ccid3hcrx_state;
757 ccid3_pr_debug("%s(%p) %-8.8s -> %s\n",
758 dccp_role(sk), sk, ccid3_rx_state_name(oldstate),
759 ccid3_rx_state_name(state));
760 WARN_ON(state == oldstate);
761 hcrx->ccid3hcrx_state = state;
764 static void ccid3_hc_rx_send_feedback(struct sock *sk)
766 struct dccp_sock *dp = dccp_sk(sk);
767 struct ccid3_hc_rx_sock *hcrx = dp->dccps_hc_rx_ccid_private;
768 struct dccp_rx_hist_entry *packet;
771 ccid3_pr_debug("%s, sk=%p\n", dccp_role(sk), sk);
773 do_gettimeofday(&now);
775 switch (hcrx->ccid3hcrx_state) {
776 case TFRC_RSTATE_NO_DATA:
777 hcrx->ccid3hcrx_x_recv = 0;
779 case TFRC_RSTATE_DATA: {
780 const u32 delta = timeval_delta(&now,
781 &hcrx->ccid3hcrx_tstamp_last_feedback);
782 hcrx->ccid3hcrx_x_recv = usecs_div(hcrx->ccid3hcrx_bytes_recv,
787 printk(KERN_CRIT "%s: %s, sk=%p, Illegal state (%d)!\n",
788 __FUNCTION__, dccp_role(sk), sk, hcrx->ccid3hcrx_state);
793 packet = dccp_rx_hist_find_data_packet(&hcrx->ccid3hcrx_hist);
794 if (packet == NULL) {
795 printk(KERN_CRIT "%s: %s, sk=%p, no data packet in history!\n",
796 __FUNCTION__, dccp_role(sk), sk);
801 hcrx->ccid3hcrx_tstamp_last_feedback = now;
802 hcrx->ccid3hcrx_last_counter = packet->dccphrx_ccval;
803 hcrx->ccid3hcrx_seqno_last_counter = packet->dccphrx_seqno;
804 hcrx->ccid3hcrx_bytes_recv = 0;
806 /* Convert to multiples of 10us */
807 hcrx->ccid3hcrx_elapsed_time =
808 timeval_delta(&now, &packet->dccphrx_tstamp) / 10;
809 if (hcrx->ccid3hcrx_p == 0)
810 hcrx->ccid3hcrx_pinv = ~0;
812 hcrx->ccid3hcrx_pinv = 1000000 / hcrx->ccid3hcrx_p;
813 dp->dccps_hc_rx_insert_options = 1;
817 static void ccid3_hc_rx_insert_options(struct sock *sk, struct sk_buff *skb)
819 const struct dccp_sock *dp = dccp_sk(sk);
821 struct ccid3_hc_rx_sock *hcrx = dp->dccps_hc_rx_ccid_private;
823 if (hcrx == NULL || !(sk->sk_state == DCCP_OPEN ||
824 sk->sk_state == DCCP_PARTOPEN))
827 DCCP_SKB_CB(skb)->dccpd_ccval = hcrx->ccid3hcrx_last_counter;
829 if (dccp_packet_without_ack(skb))
832 if (hcrx->ccid3hcrx_elapsed_time != 0)
833 dccp_insert_option_elapsed_time(sk, skb,
834 hcrx->ccid3hcrx_elapsed_time);
835 dccp_insert_option_timestamp(sk, skb);
836 x_recv = htonl(hcrx->ccid3hcrx_x_recv);
837 pinv = htonl(hcrx->ccid3hcrx_pinv);
838 dccp_insert_option(sk, skb, TFRC_OPT_LOSS_EVENT_RATE,
839 &pinv, sizeof(pinv));
840 dccp_insert_option(sk, skb, TFRC_OPT_RECEIVE_RATE,
841 &x_recv, sizeof(x_recv));
844 /* calculate first loss interval
846 * returns estimated loss interval in usecs */
848 static u32 ccid3_hc_rx_calc_first_li(struct sock *sk)
850 struct dccp_sock *dp = dccp_sk(sk);
851 struct ccid3_hc_rx_sock *hcrx = dp->dccps_hc_rx_ccid_private;
852 struct dccp_rx_hist_entry *entry, *next, *tail = NULL;
853 u32 rtt, delta, x_recv, fval, p, tmp2;
854 struct timeval tstamp = { 0, };
860 list_for_each_entry_safe(entry, next, &hcrx->ccid3hcrx_hist,
862 if (dccp_rx_hist_entry_data_packet(entry)) {
867 tstamp = entry->dccphrx_tstamp;
868 win_count = entry->dccphrx_ccval;
872 interval = win_count - entry->dccphrx_ccval;
874 interval += TFRC_WIN_COUNT_LIMIT;
883 printk(KERN_CRIT "%s: %s, sk=%p, packet history contains no "
885 __FUNCTION__, dccp_role(sk), sk);
890 ccid3_pr_debug("%s, sk=%p, Could not find a win_count "
891 "interval > 0. Defaulting to 1\n",
896 rtt = timeval_delta(&tstamp, &tail->dccphrx_tstamp) * 4 / interval;
897 ccid3_pr_debug("%s, sk=%p, approximated RTT to %uus\n",
898 dccp_role(sk), sk, rtt);
902 delta = timeval_now_delta(&hcrx->ccid3hcrx_tstamp_last_feedback);
903 x_recv = hcrx->ccid3hcrx_bytes_recv * USEC_PER_SEC;
904 if (likely(delta > 1))
907 tmp1 = (u64)x_recv * (u64)rtt;
908 do_div(tmp1,10000000);
910 fval = (hcrx->ccid3hcrx_s * 100000) / tmp2;
911 /* do not alter order above or you will get overflow on 32 bit */
912 p = tfrc_calc_x_reverse_lookup(fval);
913 ccid3_pr_debug("%s, sk=%p, receive rate=%u bytes/s, implied "
914 "loss rate=%u\n", dccp_role(sk), sk, x_recv, p);
922 static void ccid3_hc_rx_update_li(struct sock *sk, u64 seq_loss, u8 win_loss)
924 struct dccp_sock *dp = dccp_sk(sk);
925 struct ccid3_hc_rx_sock *hcrx = dp->dccps_hc_rx_ccid_private;
927 if (seq_loss != DCCP_MAX_SEQNO + 1 &&
928 list_empty(&hcrx->ccid3hcrx_li_hist)) {
929 struct dccp_li_hist_entry *li_tail;
931 li_tail = dccp_li_hist_interval_new(ccid3_li_hist,
932 &hcrx->ccid3hcrx_li_hist,
936 li_tail->dccplih_interval = ccid3_hc_rx_calc_first_li(sk);
938 /* FIXME: find end of interval */
941 static void ccid3_hc_rx_detect_loss(struct sock *sk)
943 struct dccp_sock *dp = dccp_sk(sk);
944 struct ccid3_hc_rx_sock *hcrx = dp->dccps_hc_rx_ccid_private;
946 const u64 seq_loss = dccp_rx_hist_detect_loss(&hcrx->ccid3hcrx_hist,
947 &hcrx->ccid3hcrx_li_hist,
950 ccid3_hc_rx_update_li(sk, seq_loss, win_loss);
953 static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb)
955 struct dccp_sock *dp = dccp_sk(sk);
956 struct ccid3_hc_rx_sock *hcrx = dp->dccps_hc_rx_ccid_private;
957 const struct dccp_options_received *opt_recv;
958 struct dccp_rx_hist_entry *packet;
967 BUG_ON(!(hcrx->ccid3hcrx_state == TFRC_RSTATE_NO_DATA ||
968 hcrx->ccid3hcrx_state == TFRC_RSTATE_DATA));
970 opt_recv = &dp->dccps_options_received;
972 switch (DCCP_SKB_CB(skb)->dccpd_type) {
974 if (hcrx->ccid3hcrx_state == TFRC_RSTATE_NO_DATA)
976 case DCCP_PKT_DATAACK:
977 if (opt_recv->dccpor_timestamp_echo == 0)
979 p_prev = hcrx->ccid3hcrx_rtt;
980 do_gettimeofday(&now);
981 hcrx->ccid3hcrx_rtt = timeval_usecs(&now) -
982 (opt_recv->dccpor_timestamp_echo -
983 opt_recv->dccpor_elapsed_time) * 10;
984 if (p_prev != hcrx->ccid3hcrx_rtt)
985 ccid3_pr_debug("%s, New RTT=%luus, elapsed time=%u\n",
986 dccp_role(sk), hcrx->ccid3hcrx_rtt,
987 opt_recv->dccpor_elapsed_time);
992 ccid3_pr_debug("%s, sk=%p, not DATA/DATAACK/ACK packet(%s)\n",
994 dccp_packet_name(DCCP_SKB_CB(skb)->dccpd_type));
998 packet = dccp_rx_hist_entry_new(ccid3_rx_hist, opt_recv->dccpor_ndp,
1000 if (packet == NULL) {
1001 ccid3_pr_debug("%s, sk=%p, Not enough mem to add rx packet "
1002 "to history (consider it lost)!",
1007 win_count = packet->dccphrx_ccval;
1009 ins = dccp_rx_hist_add_packet(ccid3_rx_hist, &hcrx->ccid3hcrx_hist,
1010 &hcrx->ccid3hcrx_li_hist, packet);
1012 if (DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_ACK)
1015 switch (hcrx->ccid3hcrx_state) {
1016 case TFRC_RSTATE_NO_DATA:
1017 ccid3_pr_debug("%s, sk=%p(%s), skb=%p, sending initial "
1020 dccp_state_name(sk->sk_state), skb);
1021 ccid3_hc_rx_send_feedback(sk);
1022 ccid3_hc_rx_set_state(sk, TFRC_RSTATE_DATA);
1024 case TFRC_RSTATE_DATA:
1025 hcrx->ccid3hcrx_bytes_recv += skb->len -
1026 dccp_hdr(skb)->dccph_doff * 4;
1030 do_gettimeofday(&now);
1031 if (timeval_delta(&now, &hcrx->ccid3hcrx_tstamp_last_ack) >=
1032 hcrx->ccid3hcrx_rtt) {
1033 hcrx->ccid3hcrx_tstamp_last_ack = now;
1034 ccid3_hc_rx_send_feedback(sk);
1038 printk(KERN_CRIT "%s: %s, sk=%p, Illegal state (%d)!\n",
1039 __FUNCTION__, dccp_role(sk), sk, hcrx->ccid3hcrx_state);
1044 /* Dealing with packet loss */
1045 ccid3_pr_debug("%s, sk=%p(%s), data loss! Reacting...\n",
1046 dccp_role(sk), sk, dccp_state_name(sk->sk_state));
1048 ccid3_hc_rx_detect_loss(sk);
1049 p_prev = hcrx->ccid3hcrx_p;
1051 /* Calculate loss event rate */
1052 if (!list_empty(&hcrx->ccid3hcrx_li_hist))
1053 /* Scaling up by 1000000 as fixed decimal */
1054 hcrx->ccid3hcrx_p = 1000000 / dccp_li_hist_calc_i_mean(&hcrx->ccid3hcrx_li_hist);
1056 if (hcrx->ccid3hcrx_p > p_prev) {
1057 ccid3_hc_rx_send_feedback(sk);
1062 static int ccid3_hc_rx_init(struct sock *sk)
1064 struct dccp_sock *dp = dccp_sk(sk);
1065 struct ccid3_hc_rx_sock *hcrx;
1067 ccid3_pr_debug("%s, sk=%p\n", dccp_role(sk), sk);
1069 hcrx = dp->dccps_hc_rx_ccid_private = kmalloc(sizeof(*hcrx),
1074 memset(hcrx, 0, sizeof(*hcrx));
1076 if (dp->dccps_packet_size >= TFRC_MIN_PACKET_SIZE &&
1077 dp->dccps_packet_size <= TFRC_MAX_PACKET_SIZE)
1078 hcrx->ccid3hcrx_s = dp->dccps_packet_size;
1080 hcrx->ccid3hcrx_s = TFRC_STD_PACKET_SIZE;
1082 hcrx->ccid3hcrx_state = TFRC_RSTATE_NO_DATA;
1083 INIT_LIST_HEAD(&hcrx->ccid3hcrx_hist);
1084 INIT_LIST_HEAD(&hcrx->ccid3hcrx_li_hist);
1086 * XXX this seems to be paranoid, need to think more about this, for
1087 * now start with something different than zero. -acme
1089 hcrx->ccid3hcrx_rtt = USEC_PER_SEC / 5;
1093 static void ccid3_hc_rx_exit(struct sock *sk)
1095 struct dccp_sock *dp = dccp_sk(sk);
1096 struct ccid3_hc_rx_sock *hcrx = dp->dccps_hc_rx_ccid_private;
1098 ccid3_pr_debug("%s, sk=%p\n", dccp_role(sk), sk);
1103 ccid3_hc_rx_set_state(sk, TFRC_RSTATE_TERM);
1105 /* Empty packet history */
1106 dccp_rx_hist_purge(ccid3_rx_hist, &hcrx->ccid3hcrx_hist);
1108 /* Empty loss interval history */
1109 dccp_li_hist_purge(ccid3_li_hist, &hcrx->ccid3hcrx_li_hist);
1111 kfree(dp->dccps_hc_rx_ccid_private);
1112 dp->dccps_hc_rx_ccid_private = NULL;
1115 static void ccid3_hc_rx_get_info(struct sock *sk, struct tcp_info *info)
1117 const struct dccp_sock *dp = dccp_sk(sk);
1118 const struct ccid3_hc_rx_sock *hcrx = dp->dccps_hc_rx_ccid_private;
1123 info->tcpi_ca_state = hcrx->ccid3hcrx_state;
1124 info->tcpi_options |= TCPI_OPT_TIMESTAMPS;
1125 info->tcpi_rcv_rtt = hcrx->ccid3hcrx_rtt;
1128 static void ccid3_hc_tx_get_info(struct sock *sk, struct tcp_info *info)
1130 const struct dccp_sock *dp = dccp_sk(sk);
1131 const struct ccid3_hc_tx_sock *hctx = dp->dccps_hc_tx_ccid_private;
1136 info->tcpi_rto = hctx->ccid3hctx_t_rto;
1137 info->tcpi_rtt = hctx->ccid3hctx_rtt;
1140 static struct ccid ccid3 = {
1142 .ccid_name = "ccid3",
1143 .ccid_owner = THIS_MODULE,
1144 .ccid_init = ccid3_init,
1145 .ccid_exit = ccid3_exit,
1146 .ccid_hc_tx_init = ccid3_hc_tx_init,
1147 .ccid_hc_tx_exit = ccid3_hc_tx_exit,
1148 .ccid_hc_tx_send_packet = ccid3_hc_tx_send_packet,
1149 .ccid_hc_tx_packet_sent = ccid3_hc_tx_packet_sent,
1150 .ccid_hc_tx_packet_recv = ccid3_hc_tx_packet_recv,
1151 .ccid_hc_tx_insert_options = ccid3_hc_tx_insert_options,
1152 .ccid_hc_tx_parse_options = ccid3_hc_tx_parse_options,
1153 .ccid_hc_rx_init = ccid3_hc_rx_init,
1154 .ccid_hc_rx_exit = ccid3_hc_rx_exit,
1155 .ccid_hc_rx_insert_options = ccid3_hc_rx_insert_options,
1156 .ccid_hc_rx_packet_recv = ccid3_hc_rx_packet_recv,
1157 .ccid_hc_rx_get_info = ccid3_hc_rx_get_info,
1158 .ccid_hc_tx_get_info = ccid3_hc_tx_get_info,
1161 module_param(ccid3_debug, int, 0444);
1162 MODULE_PARM_DESC(ccid3_debug, "Enable debug messages");
1164 static __init int ccid3_module_init(void)
1168 ccid3_rx_hist = dccp_rx_hist_new("ccid3");
1169 if (ccid3_rx_hist == NULL)
1172 ccid3_tx_hist = dccp_tx_hist_new("ccid3");
1173 if (ccid3_tx_hist == NULL)
1176 ccid3_li_hist = dccp_li_hist_new("ccid3");
1177 if (ccid3_li_hist == NULL)
1180 rc = ccid_register(&ccid3);
1182 goto out_free_loss_interval_history;
1186 out_free_loss_interval_history:
1187 dccp_li_hist_delete(ccid3_li_hist);
1188 ccid3_li_hist = NULL;
1190 dccp_tx_hist_delete(ccid3_tx_hist);
1191 ccid3_tx_hist = NULL;
1193 dccp_rx_hist_delete(ccid3_rx_hist);
1194 ccid3_rx_hist = NULL;
1197 module_init(ccid3_module_init);
1199 static __exit void ccid3_module_exit(void)
1201 #ifdef CONFIG_IP_DCCP_UNLOAD_HACK
1203 * Hack to use while developing, so that we get rid of the control
1204 * sock, that is what keeps a refcount on dccp.ko -acme
1206 extern void dccp_ctl_sock_exit(void);
1208 dccp_ctl_sock_exit();
1210 ccid_unregister(&ccid3);
1212 if (ccid3_tx_hist != NULL) {
1213 dccp_tx_hist_delete(ccid3_tx_hist);
1214 ccid3_tx_hist = NULL;
1216 if (ccid3_rx_hist != NULL) {
1217 dccp_rx_hist_delete(ccid3_rx_hist);
1218 ccid3_rx_hist = NULL;
1220 if (ccid3_li_hist != NULL) {
1221 dccp_li_hist_delete(ccid3_li_hist);
1222 ccid3_li_hist = NULL;
1225 module_exit(ccid3_module_exit);
1227 MODULE_AUTHOR("Ian McDonald <iam4@cs.waikato.ac.nz>, "
1228 "Arnaldo Carvalho de Melo <acme@ghostprotocols.net>");
1229 MODULE_DESCRIPTION("DCCP TFRC CCID3 CCID");
1230 MODULE_LICENSE("GPL");
1231 MODULE_ALIAS("net-dccp-ccid-3");