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 with 10 here is to avoid 32 bit overflow when a is big.
48 static inline u32
usecs_div(const u32 a
, const u32 b
)
50 const u32 tmp
= a
* (USEC_PER_SEC
/ 10);
51 return b
> 20 ? tmp
/ (b
/ 10) : tmp
;
54 static int ccid3_debug
;
57 #define ccid3_pr_debug(format, a...) \
58 do { if (ccid3_debug) \
59 printk(KERN_DEBUG "%s: " format, __FUNCTION__, ##a); \
62 #define ccid3_pr_debug(format, a...)
65 static struct dccp_tx_hist
*ccid3_tx_hist
;
66 static struct dccp_rx_hist
*ccid3_rx_hist
;
67 static struct dccp_li_hist
*ccid3_li_hist
;
69 static int ccid3_init(struct sock
*sk
)
71 ccid3_pr_debug("%s, sk=%p\n", dccp_role(sk
), sk
);
75 static void ccid3_exit(struct sock
*sk
)
77 ccid3_pr_debug("%s, sk=%p\n", dccp_role(sk
), sk
);
80 /* TFRC sender states */
81 enum ccid3_hc_tx_states
{
82 TFRC_SSTATE_NO_SENT
= 1,
89 static const char *ccid3_tx_state_name(enum ccid3_hc_tx_states state
)
91 static char *ccid3_state_names
[] = {
92 [TFRC_SSTATE_NO_SENT
] = "NO_SENT",
93 [TFRC_SSTATE_NO_FBACK
] = "NO_FBACK",
94 [TFRC_SSTATE_FBACK
] = "FBACK",
95 [TFRC_SSTATE_TERM
] = "TERM",
98 return ccid3_state_names
[state
];
102 static inline void ccid3_hc_tx_set_state(struct sock
*sk
,
103 enum ccid3_hc_tx_states state
)
105 struct dccp_sock
*dp
= dccp_sk(sk
);
106 struct ccid3_hc_tx_sock
*hctx
= dp
->dccps_hc_tx_ccid_private
;
107 enum ccid3_hc_tx_states oldstate
= hctx
->ccid3hctx_state
;
109 ccid3_pr_debug("%s(%p) %-8.8s -> %s\n",
110 dccp_role(sk
), sk
, ccid3_tx_state_name(oldstate
),
111 ccid3_tx_state_name(state
));
112 WARN_ON(state
== oldstate
);
113 hctx
->ccid3hctx_state
= state
;
116 /* Calculate new t_ipi (inter packet interval) by t_ipi = s / X_inst */
117 static inline void ccid3_calc_new_t_ipi(struct ccid3_hc_tx_sock
*hctx
)
120 * If no feedback spec says t_ipi is 1 second (set elsewhere and then
121 * doubles after every no feedback timer (separate function)
123 if (hctx
->ccid3hctx_state
!= TFRC_SSTATE_NO_FBACK
)
124 hctx
->ccid3hctx_t_ipi
= usecs_div(hctx
->ccid3hctx_s
,
128 /* Calculate new delta by delta = min(t_ipi / 2, t_gran / 2) */
129 static inline void ccid3_calc_new_delta(struct ccid3_hc_tx_sock
*hctx
)
131 hctx
->ccid3hctx_delta
= min_t(u32
, hctx
->ccid3hctx_t_ipi
/ 2,
132 TFRC_OPSYS_HALF_TIME_GRAN
);
138 * x_calc = calcX(s, R, p);
139 * X = max(min(X_calc, 2 * X_recv), s / t_mbi);
141 * If (now - tld >= R)
142 * X = max(min(2 * X, 2 * X_recv), s / R);
145 static void ccid3_hc_tx_update_x(struct sock
*sk
)
147 struct dccp_sock
*dp
= dccp_sk(sk
);
148 struct ccid3_hc_tx_sock
*hctx
= dp
->dccps_hc_tx_ccid_private
;
150 /* To avoid large error in calcX */
151 if (hctx
->ccid3hctx_p
>= TFRC_SMALLEST_P
) {
152 hctx
->ccid3hctx_x_calc
= tfrc_calc_x(hctx
->ccid3hctx_s
,
155 hctx
->ccid3hctx_x
= max_t(u32
, min_t(u32
, hctx
->ccid3hctx_x_calc
,
156 2 * hctx
->ccid3hctx_x_recv
),
158 TFRC_MAX_BACK_OFF_TIME
));
162 do_gettimeofday(&now
);
163 if (timeval_delta(&now
, &hctx
->ccid3hctx_t_ld
) >=
164 hctx
->ccid3hctx_rtt
) {
165 hctx
->ccid3hctx_x
= max_t(u32
, min_t(u32
, hctx
->ccid3hctx_x_recv
,
166 hctx
->ccid3hctx_x
) * 2,
167 usecs_div(hctx
->ccid3hctx_s
,
168 hctx
->ccid3hctx_rtt
));
169 hctx
->ccid3hctx_t_ld
= now
;
174 static void ccid3_hc_tx_no_feedback_timer(unsigned long data
)
176 struct sock
*sk
= (struct sock
*)data
;
177 struct dccp_sock
*dp
= dccp_sk(sk
);
178 unsigned long next_tmout
= 0;
179 struct ccid3_hc_tx_sock
*hctx
= dp
->dccps_hc_tx_ccid_private
;
182 if (sock_owned_by_user(sk
)) {
183 /* Try again later. */
184 /* XXX: set some sensible MIB */
185 sk_reset_timer(sk
, &hctx
->ccid3hctx_no_feedback_timer
,
190 ccid3_pr_debug("%s, sk=%p, state=%s\n", dccp_role(sk
), sk
,
191 ccid3_tx_state_name(hctx
->ccid3hctx_state
));
193 switch (hctx
->ccid3hctx_state
) {
194 case TFRC_SSTATE_TERM
:
196 case TFRC_SSTATE_NO_FBACK
:
197 /* Halve send rate */
198 hctx
->ccid3hctx_x
/= 2;
199 if (hctx
->ccid3hctx_x
< (hctx
->ccid3hctx_s
/
200 TFRC_MAX_BACK_OFF_TIME
))
201 hctx
->ccid3hctx_x
= (hctx
->ccid3hctx_s
/
202 TFRC_MAX_BACK_OFF_TIME
);
204 ccid3_pr_debug("%s, sk=%p, state=%s, updated tx rate to %d "
207 ccid3_tx_state_name(hctx
->ccid3hctx_state
),
209 next_tmout
= max_t(u32
, 2 * usecs_div(hctx
->ccid3hctx_s
,
211 TFRC_INITIAL_TIMEOUT
);
213 * FIXME - not sure above calculation is correct. See section
214 * 5 of CCID3 11 should adjust tx_t_ipi and double that to
218 case TFRC_SSTATE_FBACK
:
220 * Check if IDLE since last timeout and recv rate is less than
223 if (!hctx
->ccid3hctx_idle
||
224 (hctx
->ccid3hctx_x_recv
>=
225 4 * usecs_div(hctx
->ccid3hctx_s
, hctx
->ccid3hctx_rtt
))) {
226 ccid3_pr_debug("%s, sk=%p, state=%s, not idle\n",
228 ccid3_tx_state_name(hctx
->ccid3hctx_state
));
229 /* Halve sending rate */
231 /* If (X_calc > 2 * X_recv)
232 * X_recv = max(X_recv / 2, s / (2 * t_mbi));
234 * X_recv = X_calc / 4;
236 BUG_ON(hctx
->ccid3hctx_p
>= TFRC_SMALLEST_P
&&
237 hctx
->ccid3hctx_x_calc
== 0);
239 /* check also if p is zero -> x_calc is infinity? */
240 if (hctx
->ccid3hctx_p
< TFRC_SMALLEST_P
||
241 hctx
->ccid3hctx_x_calc
> 2 * hctx
->ccid3hctx_x_recv
)
242 hctx
->ccid3hctx_x_recv
= max_t(u32
, hctx
->ccid3hctx_x_recv
/ 2,
243 hctx
->ccid3hctx_s
/ (2 * TFRC_MAX_BACK_OFF_TIME
));
245 hctx
->ccid3hctx_x_recv
= hctx
->ccid3hctx_x_calc
/ 4;
247 /* Update sending rate */
248 ccid3_hc_tx_update_x(sk
);
251 * Schedule no feedback timer to expire in
252 * max(4 * R, 2 * s / X)
254 next_tmout
= max_t(u32
, hctx
->ccid3hctx_t_rto
,
255 2 * usecs_div(hctx
->ccid3hctx_s
,
259 printk(KERN_CRIT
"%s: %s, sk=%p, Illegal state (%d)!\n",
260 __FUNCTION__
, dccp_role(sk
), sk
, hctx
->ccid3hctx_state
);
265 sk_reset_timer(sk
, &hctx
->ccid3hctx_no_feedback_timer
,
266 jiffies
+ max_t(u32
, 1, usecs_to_jiffies(next_tmout
)));
267 hctx
->ccid3hctx_idle
= 1;
273 static int ccid3_hc_tx_send_packet(struct sock
*sk
,
274 struct sk_buff
*skb
, int len
)
276 struct dccp_sock
*dp
= dccp_sk(sk
);
277 struct ccid3_hc_tx_sock
*hctx
= dp
->dccps_hc_tx_ccid_private
;
278 struct dccp_tx_hist_entry
*new_packet
;
283 /* Check if pure ACK or Terminating*/
286 * XXX: We only call this function for DATA and DATAACK, on, these
287 * packets can have zero length, but why the comment about "pure ACK"?
289 if (hctx
== NULL
|| len
== 0 ||
290 hctx
->ccid3hctx_state
== TFRC_SSTATE_TERM
)
293 /* See if last packet allocated was not sent */
294 new_packet
= dccp_tx_hist_head(&hctx
->ccid3hctx_hist
);
295 if (new_packet
== NULL
|| new_packet
->dccphtx_sent
) {
296 new_packet
= dccp_tx_hist_entry_new(ccid3_tx_hist
,
300 if (new_packet
== NULL
) {
301 ccid3_pr_debug("%s, sk=%p, not enough mem to add "
302 "to history, send refused\n",
307 dccp_tx_hist_add_entry(&hctx
->ccid3hctx_hist
, new_packet
);
310 do_gettimeofday(&now
);
312 switch (hctx
->ccid3hctx_state
) {
313 case TFRC_SSTATE_NO_SENT
:
314 ccid3_pr_debug("%s, sk=%p, first packet(%llu)\n",
315 dccp_role(sk
), sk
, dp
->dccps_gss
);
317 hctx
->ccid3hctx_no_feedback_timer
.function
= ccid3_hc_tx_no_feedback_timer
;
318 hctx
->ccid3hctx_no_feedback_timer
.data
= (unsigned long)sk
;
319 sk_reset_timer(sk
, &hctx
->ccid3hctx_no_feedback_timer
,
320 jiffies
+ usecs_to_jiffies(TFRC_INITIAL_TIMEOUT
));
321 hctx
->ccid3hctx_last_win_count
= 0;
322 hctx
->ccid3hctx_t_last_win_count
= now
;
323 ccid3_hc_tx_set_state(sk
, TFRC_SSTATE_NO_FBACK
);
324 hctx
->ccid3hctx_t_ipi
= TFRC_INITIAL_TIMEOUT
;
326 /* Set nominal send time for initial packet */
327 hctx
->ccid3hctx_t_nom
= now
;
328 timeval_add_usecs(&hctx
->ccid3hctx_t_nom
,
329 hctx
->ccid3hctx_t_ipi
);
330 ccid3_calc_new_delta(hctx
);
333 case TFRC_SSTATE_NO_FBACK
:
334 case TFRC_SSTATE_FBACK
:
335 delay
= (timeval_delta(&now
, &hctx
->ccid3hctx_t_nom
) -
336 hctx
->ccid3hctx_delta
);
337 ccid3_pr_debug("send_packet delay=%ld\n", delay
);
339 /* divide by -1000 is to convert to ms and get sign right */
340 rc
= delay
> 0 ? delay
: 0;
343 printk(KERN_CRIT
"%s: %s, sk=%p, Illegal state (%d)!\n",
344 __FUNCTION__
, dccp_role(sk
), sk
, hctx
->ccid3hctx_state
);
350 /* Can we send? if so add options and add to packet history */
352 new_packet
->dccphtx_ccval
=
353 DCCP_SKB_CB(skb
)->dccpd_ccval
=
354 hctx
->ccid3hctx_last_win_count
;
359 static void ccid3_hc_tx_packet_sent(struct sock
*sk
, int more
, int len
)
361 struct dccp_sock
*dp
= dccp_sk(sk
);
362 struct ccid3_hc_tx_sock
*hctx
= dp
->dccps_hc_tx_ccid_private
;
365 BUG_ON(hctx
== NULL
);
367 if (hctx
->ccid3hctx_state
== TFRC_SSTATE_TERM
) {
368 ccid3_pr_debug("%s, sk=%p, while state is TFRC_SSTATE_TERM!\n",
373 do_gettimeofday(&now
);
375 /* check if we have sent a data packet */
377 unsigned long quarter_rtt
;
378 struct dccp_tx_hist_entry
*packet
;
380 packet
= dccp_tx_hist_head(&hctx
->ccid3hctx_hist
);
381 if (packet
== NULL
) {
382 printk(KERN_CRIT
"%s: packet doesn't exists in "
383 "history!\n", __FUNCTION__
);
386 if (packet
->dccphtx_sent
) {
387 printk(KERN_CRIT
"%s: no unsent packet in history!\n",
391 packet
->dccphtx_tstamp
= now
;
392 packet
->dccphtx_seqno
= dp
->dccps_gss
;
394 * Check if win_count have changed
395 * Algorithm in "8.1. Window Counter Valuer" in
396 * draft-ietf-dccp-ccid3-11.txt
398 quarter_rtt
= timeval_delta(&now
, &hctx
->ccid3hctx_t_last_win_count
);
399 if (likely(hctx
->ccid3hctx_rtt
> 8))
400 quarter_rtt
/= hctx
->ccid3hctx_rtt
/ 4;
402 if (quarter_rtt
> 0) {
403 hctx
->ccid3hctx_t_last_win_count
= now
;
404 hctx
->ccid3hctx_last_win_count
= (hctx
->ccid3hctx_last_win_count
+
405 min_t(unsigned long, quarter_rtt
, 5)) % 16;
406 ccid3_pr_debug("%s, sk=%p, window changed from "
409 packet
->dccphtx_ccval
,
410 hctx
->ccid3hctx_last_win_count
);
413 hctx
->ccid3hctx_idle
= 0;
414 packet
->dccphtx_rtt
= hctx
->ccid3hctx_rtt
;
415 packet
->dccphtx_sent
= 1;
417 ccid3_pr_debug("%s, sk=%p, seqno=%llu NOT inserted!\n",
418 dccp_role(sk
), sk
, dp
->dccps_gss
);
420 switch (hctx
->ccid3hctx_state
) {
421 case TFRC_SSTATE_NO_SENT
:
422 /* if first wasn't pure ack */
424 printk(KERN_CRIT
"%s: %s, First packet sent is noted "
425 "as a data packet\n",
426 __FUNCTION__
, dccp_role(sk
));
428 case TFRC_SSTATE_NO_FBACK
:
429 case TFRC_SSTATE_FBACK
:
431 hctx
->ccid3hctx_t_nom
= now
;
432 ccid3_calc_new_t_ipi(hctx
);
433 ccid3_calc_new_delta(hctx
);
434 timeval_add_usecs(&hctx
->ccid3hctx_t_nom
,
435 hctx
->ccid3hctx_t_ipi
);
439 printk(KERN_CRIT
"%s: %s, sk=%p, Illegal state (%d)!\n",
440 __FUNCTION__
, dccp_role(sk
), sk
, hctx
->ccid3hctx_state
);
446 static void ccid3_hc_tx_packet_recv(struct sock
*sk
, struct sk_buff
*skb
)
448 struct dccp_sock
*dp
= dccp_sk(sk
);
449 struct ccid3_hc_tx_sock
*hctx
= dp
->dccps_hc_tx_ccid_private
;
450 struct ccid3_options_received
*opt_recv
;
451 struct dccp_tx_hist_entry
*packet
;
452 unsigned long next_tmout
;
461 if (hctx
->ccid3hctx_state
== TFRC_SSTATE_TERM
) {
462 ccid3_pr_debug("%s, sk=%p, received a packet when "
463 "terminating!\n", dccp_role(sk
), sk
);
467 /* we are only interested in ACKs */
468 if (!(DCCP_SKB_CB(skb
)->dccpd_type
== DCCP_PKT_ACK
||
469 DCCP_SKB_CB(skb
)->dccpd_type
== DCCP_PKT_DATAACK
))
472 opt_recv
= &hctx
->ccid3hctx_options_received
;
474 t_elapsed
= dp
->dccps_options_received
.dccpor_elapsed_time
;
475 x_recv
= opt_recv
->ccid3or_receive_rate
;
476 pinv
= opt_recv
->ccid3or_loss_event_rate
;
478 switch (hctx
->ccid3hctx_state
) {
479 case TFRC_SSTATE_NO_SENT
:
480 /* FIXME: what to do here? */
482 case TFRC_SSTATE_NO_FBACK
:
483 case TFRC_SSTATE_FBACK
:
484 /* Calculate new round trip sample by
485 * R_sample = (now - t_recvdata) - t_delay */
486 /* get t_recvdata from history */
487 packet
= dccp_tx_hist_find_entry(&hctx
->ccid3hctx_hist
,
488 DCCP_SKB_CB(skb
)->dccpd_ack_seq
);
489 if (packet
== NULL
) {
490 ccid3_pr_debug("%s, sk=%p, seqno %llu(%s) does't "
491 "exist in history!\n",
493 DCCP_SKB_CB(skb
)->dccpd_ack_seq
,
494 dccp_packet_name(DCCP_SKB_CB(skb
)->dccpd_type
));
499 r_sample
= timeval_now_delta(&packet
->dccphtx_tstamp
);
501 // r_sample -= usecs_to_jiffies(t_elapsed * 10);
503 /* Update RTT estimate by
504 * If (No feedback recv)
507 * R = q * R + (1 - q) * R_sample;
509 * q is a constant, RFC 3448 recomments 0.9
511 if (hctx
->ccid3hctx_state
== TFRC_SSTATE_NO_FBACK
) {
512 ccid3_hc_tx_set_state(sk
, TFRC_SSTATE_FBACK
);
513 hctx
->ccid3hctx_rtt
= r_sample
;
515 hctx
->ccid3hctx_rtt
= (hctx
->ccid3hctx_rtt
* 9) / 10 +
518 ccid3_pr_debug("%s, sk=%p, New RTT estimate=%uus, "
519 "r_sample=%us\n", dccp_role(sk
), sk
,
520 hctx
->ccid3hctx_rtt
, r_sample
);
522 /* Update timeout interval */
523 hctx
->ccid3hctx_t_rto
= max_t(u32
, 4 * hctx
->ccid3hctx_rtt
,
526 /* Update receive rate */
527 hctx
->ccid3hctx_x_recv
= x_recv
;/* X_recv in bytes per sec */
529 /* Update loss event rate */
530 if (pinv
== ~0 || pinv
== 0)
531 hctx
->ccid3hctx_p
= 0;
533 hctx
->ccid3hctx_p
= 1000000 / pinv
;
535 if (hctx
->ccid3hctx_p
< TFRC_SMALLEST_P
) {
536 hctx
->ccid3hctx_p
= TFRC_SMALLEST_P
;
537 ccid3_pr_debug("%s, sk=%p, Smallest p used!\n",
542 /* unschedule no feedback timer */
543 sk_stop_timer(sk
, &hctx
->ccid3hctx_no_feedback_timer
);
545 /* Update sending rate */
546 ccid3_hc_tx_update_x(sk
);
548 /* Update next send time */
549 timeval_sub_usecs(&hctx
->ccid3hctx_t_nom
,
550 hctx
->ccid3hctx_t_ipi
);
551 ccid3_calc_new_t_ipi(hctx
);
552 timeval_add_usecs(&hctx
->ccid3hctx_t_nom
,
553 hctx
->ccid3hctx_t_ipi
);
554 ccid3_calc_new_delta(hctx
);
556 /* remove all packets older than the one acked from history */
557 dccp_tx_hist_purge_older(ccid3_tx_hist
,
558 &hctx
->ccid3hctx_hist
, packet
);
561 * Schedule no feedback timer to expire in
562 * max(4 * R, 2 * s / X)
564 next_tmout
= max(hctx
->ccid3hctx_t_rto
,
565 2 * usecs_div(hctx
->ccid3hctx_s
,
568 ccid3_pr_debug("%s, sk=%p, Scheduled no feedback timer to "
569 "expire in %lu jiffies (%luus)\n",
571 usecs_to_jiffies(next_tmout
), next_tmout
);
573 sk_reset_timer(sk
, &hctx
->ccid3hctx_no_feedback_timer
,
574 jiffies
+ max_t(u32
, 1, usecs_to_jiffies(next_tmout
)));
577 hctx
->ccid3hctx_idle
= 1;
580 printk(KERN_CRIT
"%s: %s, sk=%p, Illegal state (%d)!\n",
581 __FUNCTION__
, dccp_role(sk
), sk
, hctx
->ccid3hctx_state
);
587 static void ccid3_hc_tx_insert_options(struct sock
*sk
, struct sk_buff
*skb
)
589 const struct dccp_sock
*dp
= dccp_sk(sk
);
590 struct ccid3_hc_tx_sock
*hctx
= dp
->dccps_hc_tx_ccid_private
;
592 if (hctx
== NULL
|| !(sk
->sk_state
== DCCP_OPEN
||
593 sk
->sk_state
== DCCP_PARTOPEN
))
596 DCCP_SKB_CB(skb
)->dccpd_ccval
= hctx
->ccid3hctx_last_win_count
;
599 static int ccid3_hc_tx_parse_options(struct sock
*sk
, unsigned char option
,
600 unsigned char len
, u16 idx
,
601 unsigned char *value
)
604 struct dccp_sock
*dp
= dccp_sk(sk
);
605 struct ccid3_hc_tx_sock
*hctx
= dp
->dccps_hc_tx_ccid_private
;
606 struct ccid3_options_received
*opt_recv
;
611 opt_recv
= &hctx
->ccid3hctx_options_received
;
613 if (opt_recv
->ccid3or_seqno
!= dp
->dccps_gsr
) {
614 opt_recv
->ccid3or_seqno
= dp
->dccps_gsr
;
615 opt_recv
->ccid3or_loss_event_rate
= ~0;
616 opt_recv
->ccid3or_loss_intervals_idx
= 0;
617 opt_recv
->ccid3or_loss_intervals_len
= 0;
618 opt_recv
->ccid3or_receive_rate
= 0;
622 case TFRC_OPT_LOSS_EVENT_RATE
:
624 ccid3_pr_debug("%s, sk=%p, invalid len for "
625 "TFRC_OPT_LOSS_EVENT_RATE\n",
629 opt_recv
->ccid3or_loss_event_rate
= ntohl(*(u32
*)value
);
630 ccid3_pr_debug("%s, sk=%p, LOSS_EVENT_RATE=%u\n",
632 opt_recv
->ccid3or_loss_event_rate
);
635 case TFRC_OPT_LOSS_INTERVALS
:
636 opt_recv
->ccid3or_loss_intervals_idx
= idx
;
637 opt_recv
->ccid3or_loss_intervals_len
= len
;
638 ccid3_pr_debug("%s, sk=%p, LOSS_INTERVALS=(%u, %u)\n",
640 opt_recv
->ccid3or_loss_intervals_idx
,
641 opt_recv
->ccid3or_loss_intervals_len
);
643 case TFRC_OPT_RECEIVE_RATE
:
645 ccid3_pr_debug("%s, sk=%p, invalid len for "
646 "TFRC_OPT_RECEIVE_RATE\n",
650 opt_recv
->ccid3or_receive_rate
= ntohl(*(u32
*)value
);
651 ccid3_pr_debug("%s, sk=%p, RECEIVE_RATE=%u\n",
653 opt_recv
->ccid3or_receive_rate
);
661 static int ccid3_hc_tx_init(struct sock
*sk
)
663 struct dccp_sock
*dp
= dccp_sk(sk
);
664 struct ccid3_hc_tx_sock
*hctx
;
666 ccid3_pr_debug("%s, sk=%p\n", dccp_role(sk
), sk
);
668 hctx
= dp
->dccps_hc_tx_ccid_private
= kmalloc(sizeof(*hctx
),
673 memset(hctx
, 0, sizeof(*hctx
));
675 if (dp
->dccps_avg_packet_size
>= TFRC_MIN_PACKET_SIZE
&&
676 dp
->dccps_avg_packet_size
<= TFRC_MAX_PACKET_SIZE
)
677 hctx
->ccid3hctx_s
= (u16
)dp
->dccps_avg_packet_size
;
679 hctx
->ccid3hctx_s
= TFRC_STD_PACKET_SIZE
;
681 /* Set transmission rate to 1 packet per second */
682 hctx
->ccid3hctx_x
= hctx
->ccid3hctx_s
;
683 hctx
->ccid3hctx_t_rto
= USEC_PER_SEC
;
684 hctx
->ccid3hctx_state
= TFRC_SSTATE_NO_SENT
;
685 INIT_LIST_HEAD(&hctx
->ccid3hctx_hist
);
686 init_timer(&hctx
->ccid3hctx_no_feedback_timer
);
691 static void ccid3_hc_tx_exit(struct sock
*sk
)
693 struct dccp_sock
*dp
= dccp_sk(sk
);
694 struct ccid3_hc_tx_sock
*hctx
= dp
->dccps_hc_tx_ccid_private
;
696 ccid3_pr_debug("%s, sk=%p\n", dccp_role(sk
), sk
);
697 BUG_ON(hctx
== NULL
);
699 ccid3_hc_tx_set_state(sk
, TFRC_SSTATE_TERM
);
700 sk_stop_timer(sk
, &hctx
->ccid3hctx_no_feedback_timer
);
702 /* Empty packet history */
703 dccp_tx_hist_purge(ccid3_tx_hist
, &hctx
->ccid3hctx_hist
);
705 kfree(dp
->dccps_hc_tx_ccid_private
);
706 dp
->dccps_hc_tx_ccid_private
= NULL
;
710 * RX Half Connection methods
713 /* TFRC receiver states */
714 enum ccid3_hc_rx_states
{
715 TFRC_RSTATE_NO_DATA
= 1,
717 TFRC_RSTATE_TERM
= 127,
721 static const char *ccid3_rx_state_name(enum ccid3_hc_rx_states state
)
723 static char *ccid3_rx_state_names
[] = {
724 [TFRC_RSTATE_NO_DATA
] = "NO_DATA",
725 [TFRC_RSTATE_DATA
] = "DATA",
726 [TFRC_RSTATE_TERM
] = "TERM",
729 return ccid3_rx_state_names
[state
];
733 static inline void ccid3_hc_rx_set_state(struct sock
*sk
,
734 enum ccid3_hc_rx_states state
)
736 struct dccp_sock
*dp
= dccp_sk(sk
);
737 struct ccid3_hc_rx_sock
*hcrx
= dp
->dccps_hc_rx_ccid_private
;
738 enum ccid3_hc_rx_states oldstate
= hcrx
->ccid3hcrx_state
;
740 ccid3_pr_debug("%s(%p) %-8.8s -> %s\n",
741 dccp_role(sk
), sk
, ccid3_rx_state_name(oldstate
),
742 ccid3_rx_state_name(state
));
743 WARN_ON(state
== oldstate
);
744 hcrx
->ccid3hcrx_state
= state
;
747 static void ccid3_hc_rx_send_feedback(struct sock
*sk
)
749 struct dccp_sock
*dp
= dccp_sk(sk
);
750 struct ccid3_hc_rx_sock
*hcrx
= dp
->dccps_hc_rx_ccid_private
;
751 struct dccp_rx_hist_entry
*packet
;
754 ccid3_pr_debug("%s, sk=%p\n", dccp_role(sk
), sk
);
756 do_gettimeofday(&now
);
758 switch (hcrx
->ccid3hcrx_state
) {
759 case TFRC_RSTATE_NO_DATA
:
760 hcrx
->ccid3hcrx_x_recv
= 0;
762 case TFRC_RSTATE_DATA
: {
763 const u32 delta
= timeval_delta(&now
,
764 &hcrx
->ccid3hcrx_tstamp_last_feedback
);
766 hcrx
->ccid3hcrx_x_recv
= (hcrx
->ccid3hcrx_bytes_recv
*
768 if (likely(delta
> 1))
769 hcrx
->ccid3hcrx_x_recv
/= delta
;
773 printk(KERN_CRIT
"%s: %s, sk=%p, Illegal state (%d)!\n",
774 __FUNCTION__
, dccp_role(sk
), sk
, hcrx
->ccid3hcrx_state
);
779 packet
= dccp_rx_hist_find_data_packet(&hcrx
->ccid3hcrx_hist
);
780 if (packet
== NULL
) {
781 printk(KERN_CRIT
"%s: %s, sk=%p, no data packet in history!\n",
782 __FUNCTION__
, dccp_role(sk
), sk
);
787 hcrx
->ccid3hcrx_tstamp_last_feedback
= now
;
788 hcrx
->ccid3hcrx_last_counter
= packet
->dccphrx_ccval
;
789 hcrx
->ccid3hcrx_seqno_last_counter
= packet
->dccphrx_seqno
;
790 hcrx
->ccid3hcrx_bytes_recv
= 0;
792 /* Convert to multiples of 10us */
793 hcrx
->ccid3hcrx_elapsed_time
=
794 timeval_delta(&now
, &packet
->dccphrx_tstamp
) / 10;
795 if (hcrx
->ccid3hcrx_p
== 0)
796 hcrx
->ccid3hcrx_pinv
= ~0;
798 hcrx
->ccid3hcrx_pinv
= 1000000 / hcrx
->ccid3hcrx_p
;
802 static void ccid3_hc_rx_insert_options(struct sock
*sk
, struct sk_buff
*skb
)
804 const struct dccp_sock
*dp
= dccp_sk(sk
);
806 struct ccid3_hc_rx_sock
*hcrx
= dp
->dccps_hc_rx_ccid_private
;
808 if (hcrx
== NULL
|| !(sk
->sk_state
== DCCP_OPEN
||
809 sk
->sk_state
== DCCP_PARTOPEN
))
812 DCCP_SKB_CB(skb
)->dccpd_ccval
= hcrx
->ccid3hcrx_last_counter
;
814 if (dccp_packet_without_ack(skb
))
817 if (hcrx
->ccid3hcrx_elapsed_time
!= 0)
818 dccp_insert_option_elapsed_time(sk
, skb
,
819 hcrx
->ccid3hcrx_elapsed_time
);
820 dccp_insert_option_timestamp(sk
, skb
);
821 x_recv
= htonl(hcrx
->ccid3hcrx_x_recv
);
822 pinv
= htonl(hcrx
->ccid3hcrx_pinv
);
823 dccp_insert_option(sk
, skb
, TFRC_OPT_LOSS_EVENT_RATE
,
824 &pinv
, sizeof(pinv
));
825 dccp_insert_option(sk
, skb
, TFRC_OPT_RECEIVE_RATE
,
826 &x_recv
, sizeof(x_recv
));
829 /* calculate first loss interval
831 * returns estimated loss interval in usecs */
833 static u32
ccid3_hc_rx_calc_first_li(struct sock
*sk
)
835 struct dccp_sock
*dp
= dccp_sk(sk
);
836 struct ccid3_hc_rx_sock
*hcrx
= dp
->dccps_hc_rx_ccid_private
;
837 struct dccp_rx_hist_entry
*entry
, *next
, *tail
= NULL
;
838 u32 rtt
, delta
, x_recv
, fval
, p
, tmp2
;
839 struct timeval tstamp
= { 0, };
845 list_for_each_entry_safe(entry
, next
, &hcrx
->ccid3hcrx_hist
,
847 if (dccp_rx_hist_entry_data_packet(entry
)) {
852 tstamp
= entry
->dccphrx_tstamp
;
853 win_count
= entry
->dccphrx_ccval
;
857 interval
= win_count
- entry
->dccphrx_ccval
;
859 interval
+= TFRC_WIN_COUNT_LIMIT
;
868 printk(KERN_CRIT
"%s: %s, sk=%p, packet history contains no "
870 __FUNCTION__
, dccp_role(sk
), sk
);
875 ccid3_pr_debug("%s, sk=%p, Could not find a win_count "
876 "interval > 0. Defaulting to 1\n",
881 rtt
= timeval_delta(&tstamp
, &tail
->dccphrx_tstamp
) * 4 / interval
;
882 ccid3_pr_debug("%s, sk=%p, approximated RTT to %uus\n",
883 dccp_role(sk
), sk
, rtt
);
887 delta
= timeval_now_delta(&hcrx
->ccid3hcrx_tstamp_last_feedback
);
888 x_recv
= hcrx
->ccid3hcrx_bytes_recv
* USEC_PER_SEC
;
889 if (likely(delta
> 1))
892 tmp1
= (u64
)x_recv
* (u64
)rtt
;
893 do_div(tmp1
,10000000);
895 fval
= (hcrx
->ccid3hcrx_s
* 100000) / tmp2
;
896 /* do not alter order above or you will get overflow on 32 bit */
897 p
= tfrc_calc_x_reverse_lookup(fval
);
898 ccid3_pr_debug("%s, sk=%p, receive rate=%u bytes/s, implied "
899 "loss rate=%u\n", dccp_role(sk
), sk
, x_recv
, p
);
907 static void ccid3_hc_rx_update_li(struct sock
*sk
, u64 seq_loss
, u8 win_loss
)
909 struct dccp_sock
*dp
= dccp_sk(sk
);
910 struct ccid3_hc_rx_sock
*hcrx
= dp
->dccps_hc_rx_ccid_private
;
912 if (seq_loss
!= DCCP_MAX_SEQNO
+ 1 &&
913 list_empty(&hcrx
->ccid3hcrx_li_hist
)) {
914 struct dccp_li_hist_entry
*li_tail
;
916 li_tail
= dccp_li_hist_interval_new(ccid3_li_hist
,
917 &hcrx
->ccid3hcrx_li_hist
,
921 li_tail
->dccplih_interval
= ccid3_hc_rx_calc_first_li(sk
);
923 /* FIXME: find end of interval */
926 static void ccid3_hc_rx_detect_loss(struct sock
*sk
)
928 struct dccp_sock
*dp
= dccp_sk(sk
);
929 struct ccid3_hc_rx_sock
*hcrx
= dp
->dccps_hc_rx_ccid_private
;
931 const u64 seq_loss
= dccp_rx_hist_detect_loss(&hcrx
->ccid3hcrx_hist
,
932 &hcrx
->ccid3hcrx_li_hist
,
935 ccid3_hc_rx_update_li(sk
, seq_loss
, win_loss
);
938 static void ccid3_hc_rx_packet_recv(struct sock
*sk
, struct sk_buff
*skb
)
940 struct dccp_sock
*dp
= dccp_sk(sk
);
941 struct ccid3_hc_rx_sock
*hcrx
= dp
->dccps_hc_rx_ccid_private
;
942 const struct dccp_options_received
*opt_recv
;
943 struct dccp_rx_hist_entry
*packet
;
952 BUG_ON(!(hcrx
->ccid3hcrx_state
== TFRC_RSTATE_NO_DATA
||
953 hcrx
->ccid3hcrx_state
== TFRC_RSTATE_DATA
));
955 opt_recv
= &dp
->dccps_options_received
;
957 switch (DCCP_SKB_CB(skb
)->dccpd_type
) {
959 if (hcrx
->ccid3hcrx_state
== TFRC_RSTATE_NO_DATA
)
961 case DCCP_PKT_DATAACK
:
962 if (opt_recv
->dccpor_timestamp_echo
== 0)
964 p_prev
= hcrx
->ccid3hcrx_rtt
;
965 do_gettimeofday(&now
);
966 hcrx
->ccid3hcrx_rtt
= timeval_usecs(&now
) -
967 (opt_recv
->dccpor_timestamp_echo
-
968 opt_recv
->dccpor_elapsed_time
) * 10;
969 if (p_prev
!= hcrx
->ccid3hcrx_rtt
)
970 ccid3_pr_debug("%s, New RTT=%luus, elapsed time=%u\n",
971 dccp_role(sk
), hcrx
->ccid3hcrx_rtt
,
972 opt_recv
->dccpor_elapsed_time
);
977 ccid3_pr_debug("%s, sk=%p, not DATA/DATAACK/ACK packet(%s)\n",
979 dccp_packet_name(DCCP_SKB_CB(skb
)->dccpd_type
));
983 packet
= dccp_rx_hist_entry_new(ccid3_rx_hist
, opt_recv
->dccpor_ndp
,
985 if (packet
== NULL
) {
986 ccid3_pr_debug("%s, sk=%p, Not enough mem to add rx packet "
987 "to history (consider it lost)!",
992 win_count
= packet
->dccphrx_ccval
;
994 ins
= dccp_rx_hist_add_packet(ccid3_rx_hist
, &hcrx
->ccid3hcrx_hist
,
995 &hcrx
->ccid3hcrx_li_hist
, packet
);
997 if (DCCP_SKB_CB(skb
)->dccpd_type
== DCCP_PKT_ACK
)
1000 switch (hcrx
->ccid3hcrx_state
) {
1001 case TFRC_RSTATE_NO_DATA
:
1002 ccid3_pr_debug("%s, sk=%p(%s), skb=%p, sending initial "
1005 dccp_state_name(sk
->sk_state
), skb
);
1006 ccid3_hc_rx_send_feedback(sk
);
1007 ccid3_hc_rx_set_state(sk
, TFRC_RSTATE_DATA
);
1009 case TFRC_RSTATE_DATA
:
1010 hcrx
->ccid3hcrx_bytes_recv
+= skb
->len
-
1011 dccp_hdr(skb
)->dccph_doff
* 4;
1015 do_gettimeofday(&now
);
1016 if (timeval_delta(&now
, &hcrx
->ccid3hcrx_tstamp_last_ack
) >=
1017 hcrx
->ccid3hcrx_rtt
) {
1018 hcrx
->ccid3hcrx_tstamp_last_ack
= now
;
1019 ccid3_hc_rx_send_feedback(sk
);
1023 printk(KERN_CRIT
"%s: %s, sk=%p, Illegal state (%d)!\n",
1024 __FUNCTION__
, dccp_role(sk
), sk
, hcrx
->ccid3hcrx_state
);
1029 /* Dealing with packet loss */
1030 ccid3_pr_debug("%s, sk=%p(%s), data loss! Reacting...\n",
1031 dccp_role(sk
), sk
, dccp_state_name(sk
->sk_state
));
1033 ccid3_hc_rx_detect_loss(sk
);
1034 p_prev
= hcrx
->ccid3hcrx_p
;
1036 /* Calculate loss event rate */
1037 if (!list_empty(&hcrx
->ccid3hcrx_li_hist
))
1038 /* Scaling up by 1000000 as fixed decimal */
1039 hcrx
->ccid3hcrx_p
= 1000000 / dccp_li_hist_calc_i_mean(&hcrx
->ccid3hcrx_li_hist
);
1041 if (hcrx
->ccid3hcrx_p
> p_prev
) {
1042 ccid3_hc_rx_send_feedback(sk
);
1047 static int ccid3_hc_rx_init(struct sock
*sk
)
1049 struct dccp_sock
*dp
= dccp_sk(sk
);
1050 struct ccid3_hc_rx_sock
*hcrx
;
1052 ccid3_pr_debug("%s, sk=%p\n", dccp_role(sk
), sk
);
1054 hcrx
= dp
->dccps_hc_rx_ccid_private
= kmalloc(sizeof(*hcrx
),
1059 memset(hcrx
, 0, sizeof(*hcrx
));
1061 if (dp
->dccps_avg_packet_size
>= TFRC_MIN_PACKET_SIZE
&&
1062 dp
->dccps_avg_packet_size
<= TFRC_MAX_PACKET_SIZE
)
1063 hcrx
->ccid3hcrx_s
= (u16
)dp
->dccps_avg_packet_size
;
1065 hcrx
->ccid3hcrx_s
= TFRC_STD_PACKET_SIZE
;
1067 hcrx
->ccid3hcrx_state
= TFRC_RSTATE_NO_DATA
;
1068 INIT_LIST_HEAD(&hcrx
->ccid3hcrx_hist
);
1069 INIT_LIST_HEAD(&hcrx
->ccid3hcrx_li_hist
);
1071 * XXX this seems to be paranoid, need to think more about this, for
1072 * now start with something different than zero. -acme
1074 hcrx
->ccid3hcrx_rtt
= USEC_PER_SEC
/ 5;
1078 static void ccid3_hc_rx_exit(struct sock
*sk
)
1080 struct dccp_sock
*dp
= dccp_sk(sk
);
1081 struct ccid3_hc_rx_sock
*hcrx
= dp
->dccps_hc_rx_ccid_private
;
1083 ccid3_pr_debug("%s, sk=%p\n", dccp_role(sk
), sk
);
1088 ccid3_hc_rx_set_state(sk
, TFRC_RSTATE_TERM
);
1090 /* Empty packet history */
1091 dccp_rx_hist_purge(ccid3_rx_hist
, &hcrx
->ccid3hcrx_hist
);
1093 /* Empty loss interval history */
1094 dccp_li_hist_purge(ccid3_li_hist
, &hcrx
->ccid3hcrx_li_hist
);
1096 kfree(dp
->dccps_hc_rx_ccid_private
);
1097 dp
->dccps_hc_rx_ccid_private
= NULL
;
1100 static void ccid3_hc_rx_get_info(struct sock
*sk
, struct tcp_info
*info
)
1102 const struct dccp_sock
*dp
= dccp_sk(sk
);
1103 const struct ccid3_hc_rx_sock
*hcrx
= dp
->dccps_hc_rx_ccid_private
;
1108 info
->tcpi_ca_state
= hcrx
->ccid3hcrx_state
;
1109 info
->tcpi_options
|= TCPI_OPT_TIMESTAMPS
;
1110 info
->tcpi_rcv_rtt
= hcrx
->ccid3hcrx_rtt
;
1113 static void ccid3_hc_tx_get_info(struct sock
*sk
, struct tcp_info
*info
)
1115 const struct dccp_sock
*dp
= dccp_sk(sk
);
1116 const struct ccid3_hc_tx_sock
*hctx
= dp
->dccps_hc_tx_ccid_private
;
1121 info
->tcpi_rto
= hctx
->ccid3hctx_t_rto
;
1122 info
->tcpi_rtt
= hctx
->ccid3hctx_rtt
;
1125 static struct ccid ccid3
= {
1127 .ccid_name
= "ccid3",
1128 .ccid_owner
= THIS_MODULE
,
1129 .ccid_init
= ccid3_init
,
1130 .ccid_exit
= ccid3_exit
,
1131 .ccid_hc_tx_init
= ccid3_hc_tx_init
,
1132 .ccid_hc_tx_exit
= ccid3_hc_tx_exit
,
1133 .ccid_hc_tx_send_packet
= ccid3_hc_tx_send_packet
,
1134 .ccid_hc_tx_packet_sent
= ccid3_hc_tx_packet_sent
,
1135 .ccid_hc_tx_packet_recv
= ccid3_hc_tx_packet_recv
,
1136 .ccid_hc_tx_insert_options
= ccid3_hc_tx_insert_options
,
1137 .ccid_hc_tx_parse_options
= ccid3_hc_tx_parse_options
,
1138 .ccid_hc_rx_init
= ccid3_hc_rx_init
,
1139 .ccid_hc_rx_exit
= ccid3_hc_rx_exit
,
1140 .ccid_hc_rx_insert_options
= ccid3_hc_rx_insert_options
,
1141 .ccid_hc_rx_packet_recv
= ccid3_hc_rx_packet_recv
,
1142 .ccid_hc_rx_get_info
= ccid3_hc_rx_get_info
,
1143 .ccid_hc_tx_get_info
= ccid3_hc_tx_get_info
,
1146 module_param(ccid3_debug
, int, 0444);
1147 MODULE_PARM_DESC(ccid3_debug
, "Enable debug messages");
1149 static __init
int ccid3_module_init(void)
1153 ccid3_rx_hist
= dccp_rx_hist_new("ccid3");
1154 if (ccid3_rx_hist
== NULL
)
1157 ccid3_tx_hist
= dccp_tx_hist_new("ccid3");
1158 if (ccid3_tx_hist
== NULL
)
1161 ccid3_li_hist
= dccp_li_hist_new("ccid3");
1162 if (ccid3_li_hist
== NULL
)
1165 rc
= ccid_register(&ccid3
);
1167 goto out_free_loss_interval_history
;
1171 out_free_loss_interval_history
:
1172 dccp_li_hist_delete(ccid3_li_hist
);
1173 ccid3_li_hist
= NULL
;
1175 dccp_tx_hist_delete(ccid3_tx_hist
);
1176 ccid3_tx_hist
= NULL
;
1178 dccp_rx_hist_delete(ccid3_rx_hist
);
1179 ccid3_rx_hist
= NULL
;
1182 module_init(ccid3_module_init
);
1184 static __exit
void ccid3_module_exit(void)
1186 #ifdef CONFIG_IP_DCCP_UNLOAD_HACK
1188 * Hack to use while developing, so that we get rid of the control
1189 * sock, that is what keeps a refcount on dccp.ko -acme
1191 extern void dccp_ctl_sock_exit(void);
1193 dccp_ctl_sock_exit();
1195 ccid_unregister(&ccid3
);
1197 if (ccid3_tx_hist
!= NULL
) {
1198 dccp_tx_hist_delete(ccid3_tx_hist
);
1199 ccid3_tx_hist
= NULL
;
1201 if (ccid3_rx_hist
!= NULL
) {
1202 dccp_rx_hist_delete(ccid3_rx_hist
);
1203 ccid3_rx_hist
= NULL
;
1205 if (ccid3_li_hist
!= NULL
) {
1206 dccp_li_hist_delete(ccid3_li_hist
);
1207 ccid3_li_hist
= NULL
;
1210 module_exit(ccid3_module_exit
);
1212 MODULE_AUTHOR("Ian McDonald <iam4@cs.waikato.ac.nz>, "
1213 "Arnaldo Carvalho de Melo <acme@ghostprotocols.net>");
1214 MODULE_DESCRIPTION("DCCP TFRC CCID3 CCID");
1215 MODULE_LICENSE("GPL");
1216 MODULE_ALIAS("net-dccp-ccid-3");