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[DCCP]: Use constants for CCIDs
[GitHub/LineageOS/android_kernel_samsung_universal7580.git] / net / dccp / ccids / ccid3.c
1 /*
2 * net/dccp/ccids/ccid3.c
3 *
4 * Copyright (c) 2005 The University of Waikato, Hamilton, New Zealand.
5 * Copyright (c) 2005-6 Ian McDonald <ian.mcdonald@jandi.co.nz>
6 *
7 * An implementation of the DCCP protocol
8 *
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/
11 *
12 * This code also uses code from Lulea University, rereleased as GPL by its
13 * authors:
14 * Copyright (c) 2003 Nils-Erik Mattsson, Joacim Haggmark, Magnus Erixzon
15 *
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>.
19 *
20 * Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br>
21 *
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.
26 *
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.
31 *
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.
35 */
36
37 #include "../ccid.h"
38 #include "../dccp.h"
39 #include "lib/packet_history.h"
40 #include "lib/loss_interval.h"
41 #include "lib/tfrc.h"
42 #include "ccid3.h"
43
44 /*
45 * Reason for maths here is to avoid 32 bit overflow when a is big.
46 * With this we get close to the limit.
47 */
48 static u32 usecs_div(const u32 a, const u32 b)
49 {
50 const u32 div = a < (UINT_MAX / (USEC_PER_SEC / 10)) ? 10 :
51 a < (UINT_MAX / (USEC_PER_SEC / 50)) ? 50 :
52 a < (UINT_MAX / (USEC_PER_SEC / 100)) ? 100 :
53 a < (UINT_MAX / (USEC_PER_SEC / 500)) ? 500 :
54 a < (UINT_MAX / (USEC_PER_SEC / 1000)) ? 1000 :
55 a < (UINT_MAX / (USEC_PER_SEC / 5000)) ? 5000 :
56 a < (UINT_MAX / (USEC_PER_SEC / 10000)) ? 10000 :
57 a < (UINT_MAX / (USEC_PER_SEC / 50000)) ? 50000 :
58 100000;
59 const u32 tmp = a * (USEC_PER_SEC / div);
60 return (b >= 2 * div) ? tmp / (b / div) : tmp;
61 }
62
63 static int ccid3_debug;
64
65 #ifdef CCID3_DEBUG
66 #define ccid3_pr_debug(format, a...) \
67 do { if (ccid3_debug) \
68 printk(KERN_DEBUG "%s: " format, __FUNCTION__, ##a); \
69 } while (0)
70 #else
71 #define ccid3_pr_debug(format, a...)
72 #endif
73
74 static struct dccp_tx_hist *ccid3_tx_hist;
75 static struct dccp_rx_hist *ccid3_rx_hist;
76 static struct dccp_li_hist *ccid3_li_hist;
77
78 /* TFRC sender states */
79 enum ccid3_hc_tx_states {
80 TFRC_SSTATE_NO_SENT = 1,
81 TFRC_SSTATE_NO_FBACK,
82 TFRC_SSTATE_FBACK,
83 TFRC_SSTATE_TERM,
84 };
85
86 #ifdef CCID3_DEBUG
87 static const char *ccid3_tx_state_name(enum ccid3_hc_tx_states state)
88 {
89 static char *ccid3_state_names[] = {
90 [TFRC_SSTATE_NO_SENT] = "NO_SENT",
91 [TFRC_SSTATE_NO_FBACK] = "NO_FBACK",
92 [TFRC_SSTATE_FBACK] = "FBACK",
93 [TFRC_SSTATE_TERM] = "TERM",
94 };
95
96 return ccid3_state_names[state];
97 }
98 #endif
99
100 static void ccid3_hc_tx_set_state(struct sock *sk,
101 enum ccid3_hc_tx_states state)
102 {
103 struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
104 enum ccid3_hc_tx_states oldstate = hctx->ccid3hctx_state;
105
106 ccid3_pr_debug("%s(%p) %-8.8s -> %s\n",
107 dccp_role(sk), sk, ccid3_tx_state_name(oldstate),
108 ccid3_tx_state_name(state));
109 WARN_ON(state == oldstate);
110 hctx->ccid3hctx_state = state;
111 }
112
113 /* Calculate new t_ipi (inter packet interval) by t_ipi = s / X_inst */
114 static inline void ccid3_calc_new_t_ipi(struct ccid3_hc_tx_sock *hctx)
115 {
116 /*
117 * If no feedback spec says t_ipi is 1 second (set elsewhere and then
118 * doubles after every no feedback timer (separate function)
119 */
120 if (hctx->ccid3hctx_state != TFRC_SSTATE_NO_FBACK)
121 hctx->ccid3hctx_t_ipi = usecs_div(hctx->ccid3hctx_s,
122 hctx->ccid3hctx_x);
123 }
124
125 /* Calculate new delta by delta = min(t_ipi / 2, t_gran / 2) */
126 static inline void ccid3_calc_new_delta(struct ccid3_hc_tx_sock *hctx)
127 {
128 hctx->ccid3hctx_delta = min_t(u32, hctx->ccid3hctx_t_ipi / 2,
129 TFRC_OPSYS_HALF_TIME_GRAN);
130 }
131
132 /*
133 * Update X by
134 * If (p > 0)
135 * x_calc = calcX(s, R, p);
136 * X = max(min(X_calc, 2 * X_recv), s / t_mbi);
137 * Else
138 * If (now - tld >= R)
139 * X = max(min(2 * X, 2 * X_recv), s / R);
140 * tld = now;
141 */
142 static void ccid3_hc_tx_update_x(struct sock *sk)
143 {
144 struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
145
146 /* To avoid large error in calcX */
147 if (hctx->ccid3hctx_p >= TFRC_SMALLEST_P) {
148 hctx->ccid3hctx_x_calc = tfrc_calc_x(hctx->ccid3hctx_s,
149 hctx->ccid3hctx_rtt,
150 hctx->ccid3hctx_p);
151 hctx->ccid3hctx_x = max_t(u32, min_t(u32, hctx->ccid3hctx_x_calc,
152 2 * hctx->ccid3hctx_x_recv),
153 (hctx->ccid3hctx_s /
154 TFRC_MAX_BACK_OFF_TIME));
155 } else {
156 struct timeval now;
157
158 dccp_timestamp(sk, &now);
159 if (timeval_delta(&now, &hctx->ccid3hctx_t_ld) >=
160 hctx->ccid3hctx_rtt) {
161 hctx->ccid3hctx_x = max_t(u32, min_t(u32, hctx->ccid3hctx_x_recv,
162 hctx->ccid3hctx_x) * 2,
163 usecs_div(hctx->ccid3hctx_s,
164 hctx->ccid3hctx_rtt));
165 hctx->ccid3hctx_t_ld = now;
166 }
167 }
168 }
169
170 static void ccid3_hc_tx_no_feedback_timer(unsigned long data)
171 {
172 struct sock *sk = (struct sock *)data;
173 unsigned long next_tmout = 0;
174 struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
175
176 bh_lock_sock(sk);
177 if (sock_owned_by_user(sk)) {
178 /* Try again later. */
179 /* XXX: set some sensible MIB */
180 sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer,
181 jiffies + HZ / 5);
182 goto out;
183 }
184
185 ccid3_pr_debug("%s, sk=%p, state=%s\n", dccp_role(sk), sk,
186 ccid3_tx_state_name(hctx->ccid3hctx_state));
187
188 switch (hctx->ccid3hctx_state) {
189 case TFRC_SSTATE_TERM:
190 goto out;
191 case TFRC_SSTATE_NO_FBACK:
192 /* Halve send rate */
193 hctx->ccid3hctx_x /= 2;
194 if (hctx->ccid3hctx_x < (hctx->ccid3hctx_s /
195 TFRC_MAX_BACK_OFF_TIME))
196 hctx->ccid3hctx_x = (hctx->ccid3hctx_s /
197 TFRC_MAX_BACK_OFF_TIME);
198
199 ccid3_pr_debug("%s, sk=%p, state=%s, updated tx rate to %d "
200 "bytes/s\n",
201 dccp_role(sk), sk,
202 ccid3_tx_state_name(hctx->ccid3hctx_state),
203 hctx->ccid3hctx_x);
204 next_tmout = max_t(u32, 2 * usecs_div(hctx->ccid3hctx_s,
205 hctx->ccid3hctx_x),
206 TFRC_INITIAL_TIMEOUT);
207 /*
208 * FIXME - not sure above calculation is correct. See section
209 * 5 of CCID3 11 should adjust tx_t_ipi and double that to
210 * achieve it really
211 */
212 break;
213 case TFRC_SSTATE_FBACK:
214 /*
215 * Check if IDLE since last timeout and recv rate is less than
216 * 4 packets per RTT
217 */
218 if (!hctx->ccid3hctx_idle ||
219 (hctx->ccid3hctx_x_recv >=
220 4 * usecs_div(hctx->ccid3hctx_s, hctx->ccid3hctx_rtt))) {
221 ccid3_pr_debug("%s, sk=%p, state=%s, not idle\n",
222 dccp_role(sk), sk,
223 ccid3_tx_state_name(hctx->ccid3hctx_state));
224 /* Halve sending rate */
225
226 /* If (X_calc > 2 * X_recv)
227 * X_recv = max(X_recv / 2, s / (2 * t_mbi));
228 * Else
229 * X_recv = X_calc / 4;
230 */
231 BUG_ON(hctx->ccid3hctx_p >= TFRC_SMALLEST_P &&
232 hctx->ccid3hctx_x_calc == 0);
233
234 /* check also if p is zero -> x_calc is infinity? */
235 if (hctx->ccid3hctx_p < TFRC_SMALLEST_P ||
236 hctx->ccid3hctx_x_calc > 2 * hctx->ccid3hctx_x_recv)
237 hctx->ccid3hctx_x_recv = max_t(u32, hctx->ccid3hctx_x_recv / 2,
238 hctx->ccid3hctx_s / (2 * TFRC_MAX_BACK_OFF_TIME));
239 else
240 hctx->ccid3hctx_x_recv = hctx->ccid3hctx_x_calc / 4;
241
242 /* Update sending rate */
243 ccid3_hc_tx_update_x(sk);
244 }
245 /*
246 * Schedule no feedback timer to expire in
247 * max(4 * R, 2 * s / X)
248 */
249 next_tmout = max_t(u32, hctx->ccid3hctx_t_rto,
250 2 * usecs_div(hctx->ccid3hctx_s,
251 hctx->ccid3hctx_x));
252 break;
253 default:
254 printk(KERN_CRIT "%s: %s, sk=%p, Illegal state (%d)!\n",
255 __FUNCTION__, dccp_role(sk), sk, hctx->ccid3hctx_state);
256 dump_stack();
257 goto out;
258 }
259
260 sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer,
261 jiffies + max_t(u32, 1, usecs_to_jiffies(next_tmout)));
262 hctx->ccid3hctx_idle = 1;
263 out:
264 bh_unlock_sock(sk);
265 sock_put(sk);
266 }
267
268 static int ccid3_hc_tx_send_packet(struct sock *sk,
269 struct sk_buff *skb, int len)
270 {
271 struct dccp_sock *dp = dccp_sk(sk);
272 struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
273 struct dccp_tx_hist_entry *new_packet;
274 struct timeval now;
275 long delay;
276 int rc = -ENOTCONN;
277
278 BUG_ON(hctx == NULL || hctx->ccid3hctx_state == TFRC_SSTATE_TERM);
279
280 /* Check if pure ACK or Terminating*/
281 /*
282 * XXX: We only call this function for DATA and DATAACK, on, these
283 * packets can have zero length, but why the comment about "pure ACK"?
284 */
285 if (unlikely(len == 0))
286 goto out;
287
288 /* See if last packet allocated was not sent */
289 new_packet = dccp_tx_hist_head(&hctx->ccid3hctx_hist);
290 if (new_packet == NULL || new_packet->dccphtx_sent) {
291 new_packet = dccp_tx_hist_entry_new(ccid3_tx_hist,
292 SLAB_ATOMIC);
293
294 rc = -ENOBUFS;
295 if (unlikely(new_packet == NULL)) {
296 LIMIT_NETDEBUG(KERN_WARNING "%s: %s, sk=%p, not enough "
297 "mem to add to history, send refused\n",
298 __FUNCTION__, dccp_role(sk), sk);
299 goto out;
300 }
301
302 dccp_tx_hist_add_entry(&hctx->ccid3hctx_hist, new_packet);
303 }
304
305 dccp_timestamp(sk, &now);
306
307 switch (hctx->ccid3hctx_state) {
308 case TFRC_SSTATE_NO_SENT:
309 sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer,
310 jiffies + usecs_to_jiffies(TFRC_INITIAL_TIMEOUT));
311 hctx->ccid3hctx_last_win_count = 0;
312 hctx->ccid3hctx_t_last_win_count = now;
313 ccid3_hc_tx_set_state(sk, TFRC_SSTATE_NO_FBACK);
314 hctx->ccid3hctx_t_ipi = TFRC_INITIAL_IPI;
315
316 /* Set nominal send time for initial packet */
317 hctx->ccid3hctx_t_nom = now;
318 timeval_add_usecs(&hctx->ccid3hctx_t_nom,
319 hctx->ccid3hctx_t_ipi);
320 ccid3_calc_new_delta(hctx);
321 rc = 0;
322 break;
323 case TFRC_SSTATE_NO_FBACK:
324 case TFRC_SSTATE_FBACK:
325 delay = (timeval_delta(&now, &hctx->ccid3hctx_t_nom) -
326 hctx->ccid3hctx_delta);
327 delay /= -1000;
328 /* divide by -1000 is to convert to ms and get sign right */
329 rc = delay > 0 ? delay : 0;
330 break;
331 default:
332 printk(KERN_CRIT "%s: %s, sk=%p, Illegal state (%d)!\n",
333 __FUNCTION__, dccp_role(sk), sk, hctx->ccid3hctx_state);
334 dump_stack();
335 rc = -EINVAL;
336 break;
337 }
338
339 /* Can we send? if so add options and add to packet history */
340 if (rc == 0) {
341 dp->dccps_hc_tx_insert_options = 1;
342 new_packet->dccphtx_ccval =
343 DCCP_SKB_CB(skb)->dccpd_ccval =
344 hctx->ccid3hctx_last_win_count;
345 timeval_add_usecs(&hctx->ccid3hctx_t_nom,
346 hctx->ccid3hctx_t_ipi);
347 }
348 out:
349 return rc;
350 }
351
352 static void ccid3_hc_tx_packet_sent(struct sock *sk, int more, int len)
353 {
354 const struct dccp_sock *dp = dccp_sk(sk);
355 struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
356 struct timeval now;
357
358 BUG_ON(hctx == NULL || hctx->ccid3hctx_state == TFRC_SSTATE_TERM);
359
360 dccp_timestamp(sk, &now);
361
362 /* check if we have sent a data packet */
363 if (len > 0) {
364 unsigned long quarter_rtt;
365 struct dccp_tx_hist_entry *packet;
366
367 packet = dccp_tx_hist_head(&hctx->ccid3hctx_hist);
368 if (unlikely(packet == NULL)) {
369 LIMIT_NETDEBUG(KERN_WARNING "%s: packet doesn't "
370 "exists in history!\n", __FUNCTION__);
371 return;
372 }
373 if (unlikely(packet->dccphtx_sent)) {
374 LIMIT_NETDEBUG(KERN_WARNING "%s: no unsent packet in "
375 "history!\n", __FUNCTION__);
376 return;
377 }
378 packet->dccphtx_tstamp = now;
379 packet->dccphtx_seqno = dp->dccps_gss;
380 /*
381 * Check if win_count have changed
382 * Algorithm in "8.1. Window Counter Valuer" in
383 * draft-ietf-dccp-ccid3-11.txt
384 */
385 quarter_rtt = timeval_delta(&now, &hctx->ccid3hctx_t_last_win_count);
386 if (likely(hctx->ccid3hctx_rtt > 8))
387 quarter_rtt /= hctx->ccid3hctx_rtt / 4;
388
389 if (quarter_rtt > 0) {
390 hctx->ccid3hctx_t_last_win_count = now;
391 hctx->ccid3hctx_last_win_count = (hctx->ccid3hctx_last_win_count +
392 min_t(unsigned long, quarter_rtt, 5)) % 16;
393 ccid3_pr_debug("%s, sk=%p, window changed from "
394 "%u to %u!\n",
395 dccp_role(sk), sk,
396 packet->dccphtx_ccval,
397 hctx->ccid3hctx_last_win_count);
398 }
399
400 hctx->ccid3hctx_idle = 0;
401 packet->dccphtx_rtt = hctx->ccid3hctx_rtt;
402 packet->dccphtx_sent = 1;
403 } else
404 ccid3_pr_debug("%s, sk=%p, seqno=%llu NOT inserted!\n",
405 dccp_role(sk), sk, dp->dccps_gss);
406
407 switch (hctx->ccid3hctx_state) {
408 case TFRC_SSTATE_NO_SENT:
409 /* if first wasn't pure ack */
410 if (len != 0)
411 printk(KERN_CRIT "%s: %s, First packet sent is noted "
412 "as a data packet\n",
413 __FUNCTION__, dccp_role(sk));
414 return;
415 case TFRC_SSTATE_NO_FBACK:
416 case TFRC_SSTATE_FBACK:
417 if (len > 0) {
418 timeval_sub_usecs(&hctx->ccid3hctx_t_nom,
419 hctx->ccid3hctx_t_ipi);
420 ccid3_calc_new_t_ipi(hctx);
421 ccid3_calc_new_delta(hctx);
422 timeval_add_usecs(&hctx->ccid3hctx_t_nom,
423 hctx->ccid3hctx_t_ipi);
424 }
425 break;
426 default:
427 printk(KERN_CRIT "%s: %s, sk=%p, Illegal state (%d)!\n",
428 __FUNCTION__, dccp_role(sk), sk, hctx->ccid3hctx_state);
429 dump_stack();
430 break;
431 }
432 }
433
434 static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb)
435 {
436 const struct dccp_sock *dp = dccp_sk(sk);
437 struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
438 struct ccid3_options_received *opt_recv;
439 struct dccp_tx_hist_entry *packet;
440 struct timeval now;
441 unsigned long next_tmout;
442 u32 t_elapsed;
443 u32 pinv;
444 u32 x_recv;
445 u32 r_sample;
446
447 BUG_ON(hctx == NULL || hctx->ccid3hctx_state == TFRC_SSTATE_TERM);
448
449 /* we are only interested in ACKs */
450 if (!(DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_ACK ||
451 DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_DATAACK))
452 return;
453
454 opt_recv = &hctx->ccid3hctx_options_received;
455
456 t_elapsed = dp->dccps_options_received.dccpor_elapsed_time * 10;
457 x_recv = opt_recv->ccid3or_receive_rate;
458 pinv = opt_recv->ccid3or_loss_event_rate;
459
460 switch (hctx->ccid3hctx_state) {
461 case TFRC_SSTATE_NO_SENT:
462 /* FIXME: what to do here? */
463 return;
464 case TFRC_SSTATE_NO_FBACK:
465 case TFRC_SSTATE_FBACK:
466 /* Calculate new round trip sample by
467 * R_sample = (now - t_recvdata) - t_delay */
468 /* get t_recvdata from history */
469 packet = dccp_tx_hist_find_entry(&hctx->ccid3hctx_hist,
470 DCCP_SKB_CB(skb)->dccpd_ack_seq);
471 if (unlikely(packet == NULL)) {
472 LIMIT_NETDEBUG(KERN_WARNING "%s: %s, sk=%p, seqno "
473 "%llu(%s) does't exist in history!\n",
474 __FUNCTION__, dccp_role(sk), sk,
475 (unsigned long long)DCCP_SKB_CB(skb)->dccpd_ack_seq,
476 dccp_packet_name(DCCP_SKB_CB(skb)->dccpd_type));
477 return;
478 }
479
480 /* Update RTT */
481 dccp_timestamp(sk, &now);
482 r_sample = timeval_delta(&now, &packet->dccphtx_tstamp);
483 if (unlikely(r_sample <= t_elapsed))
484 LIMIT_NETDEBUG(KERN_WARNING "%s: r_sample=%uus, "
485 "t_elapsed=%uus\n",
486 __FUNCTION__, r_sample, t_elapsed);
487 else
488 r_sample -= t_elapsed;
489
490 /* Update RTT estimate by
491 * If (No feedback recv)
492 * R = R_sample;
493 * Else
494 * R = q * R + (1 - q) * R_sample;
495 *
496 * q is a constant, RFC 3448 recomments 0.9
497 */
498 if (hctx->ccid3hctx_state == TFRC_SSTATE_NO_FBACK) {
499 ccid3_hc_tx_set_state(sk, TFRC_SSTATE_FBACK);
500 hctx->ccid3hctx_rtt = r_sample;
501 } else
502 hctx->ccid3hctx_rtt = (hctx->ccid3hctx_rtt * 9) / 10 +
503 r_sample / 10;
504
505 ccid3_pr_debug("%s, sk=%p, New RTT estimate=%uus, "
506 "r_sample=%us\n", dccp_role(sk), sk,
507 hctx->ccid3hctx_rtt, r_sample);
508
509 /* Update timeout interval */
510 hctx->ccid3hctx_t_rto = max_t(u32, 4 * hctx->ccid3hctx_rtt,
511 USEC_PER_SEC);
512
513 /* Update receive rate */
514 hctx->ccid3hctx_x_recv = x_recv;/* X_recv in bytes per sec */
515
516 /* Update loss event rate */
517 if (pinv == ~0 || pinv == 0)
518 hctx->ccid3hctx_p = 0;
519 else {
520 hctx->ccid3hctx_p = 1000000 / pinv;
521
522 if (hctx->ccid3hctx_p < TFRC_SMALLEST_P) {
523 hctx->ccid3hctx_p = TFRC_SMALLEST_P;
524 ccid3_pr_debug("%s, sk=%p, Smallest p used!\n",
525 dccp_role(sk), sk);
526 }
527 }
528
529 /* unschedule no feedback timer */
530 sk_stop_timer(sk, &hctx->ccid3hctx_no_feedback_timer);
531
532 /* Update sending rate */
533 ccid3_hc_tx_update_x(sk);
534
535 /* Update next send time */
536 timeval_sub_usecs(&hctx->ccid3hctx_t_nom,
537 hctx->ccid3hctx_t_ipi);
538 ccid3_calc_new_t_ipi(hctx);
539 timeval_add_usecs(&hctx->ccid3hctx_t_nom,
540 hctx->ccid3hctx_t_ipi);
541 ccid3_calc_new_delta(hctx);
542
543 /* remove all packets older than the one acked from history */
544 dccp_tx_hist_purge_older(ccid3_tx_hist,
545 &hctx->ccid3hctx_hist, packet);
546 /*
547 * As we have calculated new ipi, delta, t_nom it is possible that
548 * we now can send a packet, so wake up dccp_wait_for_ccids.
549 */
550 sk->sk_write_space(sk);
551
552 /*
553 * Schedule no feedback timer to expire in
554 * max(4 * R, 2 * s / X)
555 */
556 next_tmout = max(hctx->ccid3hctx_t_rto,
557 2 * usecs_div(hctx->ccid3hctx_s,
558 hctx->ccid3hctx_x));
559
560 ccid3_pr_debug("%s, sk=%p, Scheduled no feedback timer to "
561 "expire in %lu jiffies (%luus)\n",
562 dccp_role(sk), sk,
563 usecs_to_jiffies(next_tmout), next_tmout);
564
565 sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer,
566 jiffies + max_t(u32, 1, usecs_to_jiffies(next_tmout)));
567
568 /* set idle flag */
569 hctx->ccid3hctx_idle = 1;
570 break;
571 default:
572 printk(KERN_CRIT "%s: %s, sk=%p, Illegal state (%d)!\n",
573 __FUNCTION__, dccp_role(sk), sk, hctx->ccid3hctx_state);
574 dump_stack();
575 break;
576 }
577 }
578
579 static int ccid3_hc_tx_insert_options(struct sock *sk, struct sk_buff *skb)
580 {
581 const struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
582
583 BUG_ON(hctx == NULL);
584
585 if (sk->sk_state == DCCP_OPEN || sk->sk_state == DCCP_PARTOPEN)
586 DCCP_SKB_CB(skb)->dccpd_ccval = hctx->ccid3hctx_last_win_count;
587 return 0;
588 }
589
590 static int ccid3_hc_tx_parse_options(struct sock *sk, unsigned char option,
591 unsigned char len, u16 idx,
592 unsigned char *value)
593 {
594 int rc = 0;
595 const struct dccp_sock *dp = dccp_sk(sk);
596 struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
597 struct ccid3_options_received *opt_recv;
598
599 BUG_ON(hctx == NULL);
600
601 opt_recv = &hctx->ccid3hctx_options_received;
602
603 if (opt_recv->ccid3or_seqno != dp->dccps_gsr) {
604 opt_recv->ccid3or_seqno = dp->dccps_gsr;
605 opt_recv->ccid3or_loss_event_rate = ~0;
606 opt_recv->ccid3or_loss_intervals_idx = 0;
607 opt_recv->ccid3or_loss_intervals_len = 0;
608 opt_recv->ccid3or_receive_rate = 0;
609 }
610
611 switch (option) {
612 case TFRC_OPT_LOSS_EVENT_RATE:
613 if (unlikely(len != 4)) {
614 LIMIT_NETDEBUG(KERN_WARNING "%s: %s, sk=%p, invalid "
615 "len for TFRC_OPT_LOSS_EVENT_RATE\n",
616 __FUNCTION__, dccp_role(sk), sk);
617 rc = -EINVAL;
618 } else {
619 opt_recv->ccid3or_loss_event_rate = ntohl(*(__be32 *)value);
620 ccid3_pr_debug("%s, sk=%p, LOSS_EVENT_RATE=%u\n",
621 dccp_role(sk), sk,
622 opt_recv->ccid3or_loss_event_rate);
623 }
624 break;
625 case TFRC_OPT_LOSS_INTERVALS:
626 opt_recv->ccid3or_loss_intervals_idx = idx;
627 opt_recv->ccid3or_loss_intervals_len = len;
628 ccid3_pr_debug("%s, sk=%p, LOSS_INTERVALS=(%u, %u)\n",
629 dccp_role(sk), sk,
630 opt_recv->ccid3or_loss_intervals_idx,
631 opt_recv->ccid3or_loss_intervals_len);
632 break;
633 case TFRC_OPT_RECEIVE_RATE:
634 if (unlikely(len != 4)) {
635 LIMIT_NETDEBUG(KERN_WARNING "%s: %s, sk=%p, invalid "
636 "len for TFRC_OPT_RECEIVE_RATE\n",
637 __FUNCTION__, dccp_role(sk), sk);
638 rc = -EINVAL;
639 } else {
640 opt_recv->ccid3or_receive_rate = ntohl(*(__be32 *)value);
641 ccid3_pr_debug("%s, sk=%p, RECEIVE_RATE=%u\n",
642 dccp_role(sk), sk,
643 opt_recv->ccid3or_receive_rate);
644 }
645 break;
646 }
647
648 return rc;
649 }
650
651 static int ccid3_hc_tx_init(struct ccid *ccid, struct sock *sk)
652 {
653 struct dccp_sock *dp = dccp_sk(sk);
654 struct ccid3_hc_tx_sock *hctx = ccid_priv(ccid);
655
656 if (dp->dccps_packet_size >= TFRC_MIN_PACKET_SIZE &&
657 dp->dccps_packet_size <= TFRC_MAX_PACKET_SIZE)
658 hctx->ccid3hctx_s = dp->dccps_packet_size;
659 else
660 hctx->ccid3hctx_s = TFRC_STD_PACKET_SIZE;
661
662 /* Set transmission rate to 1 packet per second */
663 hctx->ccid3hctx_x = hctx->ccid3hctx_s;
664 hctx->ccid3hctx_t_rto = USEC_PER_SEC;
665 hctx->ccid3hctx_state = TFRC_SSTATE_NO_SENT;
666 INIT_LIST_HEAD(&hctx->ccid3hctx_hist);
667
668 hctx->ccid3hctx_no_feedback_timer.function = ccid3_hc_tx_no_feedback_timer;
669 hctx->ccid3hctx_no_feedback_timer.data = (unsigned long)sk;
670 init_timer(&hctx->ccid3hctx_no_feedback_timer);
671
672 return 0;
673 }
674
675 static void ccid3_hc_tx_exit(struct sock *sk)
676 {
677 struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
678
679 BUG_ON(hctx == NULL);
680
681 ccid3_hc_tx_set_state(sk, TFRC_SSTATE_TERM);
682 sk_stop_timer(sk, &hctx->ccid3hctx_no_feedback_timer);
683
684 /* Empty packet history */
685 dccp_tx_hist_purge(ccid3_tx_hist, &hctx->ccid3hctx_hist);
686 }
687
688 /*
689 * RX Half Connection methods
690 */
691
692 /* TFRC receiver states */
693 enum ccid3_hc_rx_states {
694 TFRC_RSTATE_NO_DATA = 1,
695 TFRC_RSTATE_DATA,
696 TFRC_RSTATE_TERM = 127,
697 };
698
699 #ifdef CCID3_DEBUG
700 static const char *ccid3_rx_state_name(enum ccid3_hc_rx_states state)
701 {
702 static char *ccid3_rx_state_names[] = {
703 [TFRC_RSTATE_NO_DATA] = "NO_DATA",
704 [TFRC_RSTATE_DATA] = "DATA",
705 [TFRC_RSTATE_TERM] = "TERM",
706 };
707
708 return ccid3_rx_state_names[state];
709 }
710 #endif
711
712 static void ccid3_hc_rx_set_state(struct sock *sk,
713 enum ccid3_hc_rx_states state)
714 {
715 struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
716 enum ccid3_hc_rx_states oldstate = hcrx->ccid3hcrx_state;
717
718 ccid3_pr_debug("%s(%p) %-8.8s -> %s\n",
719 dccp_role(sk), sk, ccid3_rx_state_name(oldstate),
720 ccid3_rx_state_name(state));
721 WARN_ON(state == oldstate);
722 hcrx->ccid3hcrx_state = state;
723 }
724
725 static void ccid3_hc_rx_send_feedback(struct sock *sk)
726 {
727 struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
728 struct dccp_sock *dp = dccp_sk(sk);
729 struct dccp_rx_hist_entry *packet;
730 struct timeval now;
731
732 ccid3_pr_debug("%s, sk=%p\n", dccp_role(sk), sk);
733
734 dccp_timestamp(sk, &now);
735
736 switch (hcrx->ccid3hcrx_state) {
737 case TFRC_RSTATE_NO_DATA:
738 hcrx->ccid3hcrx_x_recv = 0;
739 break;
740 case TFRC_RSTATE_DATA: {
741 const u32 delta = timeval_delta(&now,
742 &hcrx->ccid3hcrx_tstamp_last_feedback);
743 hcrx->ccid3hcrx_x_recv = usecs_div(hcrx->ccid3hcrx_bytes_recv,
744 delta);
745 }
746 break;
747 default:
748 printk(KERN_CRIT "%s: %s, sk=%p, Illegal state (%d)!\n",
749 __FUNCTION__, dccp_role(sk), sk, hcrx->ccid3hcrx_state);
750 dump_stack();
751 return;
752 }
753
754 packet = dccp_rx_hist_find_data_packet(&hcrx->ccid3hcrx_hist);
755 if (unlikely(packet == NULL)) {
756 LIMIT_NETDEBUG(KERN_WARNING "%s: %s, sk=%p, no data packet "
757 "in history!\n",
758 __FUNCTION__, dccp_role(sk), sk);
759 return;
760 }
761
762 hcrx->ccid3hcrx_tstamp_last_feedback = now;
763 hcrx->ccid3hcrx_ccval_last_counter = packet->dccphrx_ccval;
764 hcrx->ccid3hcrx_bytes_recv = 0;
765
766 /* Convert to multiples of 10us */
767 hcrx->ccid3hcrx_elapsed_time =
768 timeval_delta(&now, &packet->dccphrx_tstamp) / 10;
769 if (hcrx->ccid3hcrx_p == 0)
770 hcrx->ccid3hcrx_pinv = ~0;
771 else
772 hcrx->ccid3hcrx_pinv = 1000000 / hcrx->ccid3hcrx_p;
773 dp->dccps_hc_rx_insert_options = 1;
774 dccp_send_ack(sk);
775 }
776
777 static int ccid3_hc_rx_insert_options(struct sock *sk, struct sk_buff *skb)
778 {
779 const struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
780 __be32 x_recv, pinv;
781
782 BUG_ON(hcrx == NULL);
783
784 if (!(sk->sk_state == DCCP_OPEN || sk->sk_state == DCCP_PARTOPEN))
785 return 0;
786
787 DCCP_SKB_CB(skb)->dccpd_ccval = hcrx->ccid3hcrx_ccval_last_counter;
788
789 if (dccp_packet_without_ack(skb))
790 return 0;
791
792 x_recv = htonl(hcrx->ccid3hcrx_x_recv);
793 pinv = htonl(hcrx->ccid3hcrx_pinv);
794
795 if ((hcrx->ccid3hcrx_elapsed_time != 0 &&
796 dccp_insert_option_elapsed_time(sk, skb,
797 hcrx->ccid3hcrx_elapsed_time)) ||
798 dccp_insert_option_timestamp(sk, skb) ||
799 dccp_insert_option(sk, skb, TFRC_OPT_LOSS_EVENT_RATE,
800 &pinv, sizeof(pinv)) ||
801 dccp_insert_option(sk, skb, TFRC_OPT_RECEIVE_RATE,
802 &x_recv, sizeof(x_recv)))
803 return -1;
804
805 return 0;
806 }
807
808 /* calculate first loss interval
809 *
810 * returns estimated loss interval in usecs */
811
812 static u32 ccid3_hc_rx_calc_first_li(struct sock *sk)
813 {
814 struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
815 struct dccp_rx_hist_entry *entry, *next, *tail = NULL;
816 u32 rtt, delta, x_recv, fval, p, tmp2;
817 struct timeval tstamp = { 0, };
818 int interval = 0;
819 int win_count = 0;
820 int step = 0;
821 u64 tmp1;
822
823 list_for_each_entry_safe(entry, next, &hcrx->ccid3hcrx_hist,
824 dccphrx_node) {
825 if (dccp_rx_hist_entry_data_packet(entry)) {
826 tail = entry;
827
828 switch (step) {
829 case 0:
830 tstamp = entry->dccphrx_tstamp;
831 win_count = entry->dccphrx_ccval;
832 step = 1;
833 break;
834 case 1:
835 interval = win_count - entry->dccphrx_ccval;
836 if (interval < 0)
837 interval += TFRC_WIN_COUNT_LIMIT;
838 if (interval > 4)
839 goto found;
840 break;
841 }
842 }
843 }
844
845 if (unlikely(step == 0)) {
846 LIMIT_NETDEBUG(KERN_WARNING "%s: %s, sk=%p, packet history "
847 "contains no data packets!\n",
848 __FUNCTION__, dccp_role(sk), sk);
849 return ~0;
850 }
851
852 if (unlikely(interval == 0)) {
853 LIMIT_NETDEBUG(KERN_WARNING "%s: %s, sk=%p, Could not find a "
854 "win_count interval > 0. Defaulting to 1\n",
855 __FUNCTION__, dccp_role(sk), sk);
856 interval = 1;
857 }
858 found:
859 if (!tail) {
860 LIMIT_NETDEBUG(KERN_WARNING "%s: tail is null\n",
861 __FUNCTION__);
862 return ~0;
863 }
864 rtt = timeval_delta(&tstamp, &tail->dccphrx_tstamp) * 4 / interval;
865 ccid3_pr_debug("%s, sk=%p, approximated RTT to %uus\n",
866 dccp_role(sk), sk, rtt);
867 if (rtt == 0)
868 rtt = 1;
869
870 dccp_timestamp(sk, &tstamp);
871 delta = timeval_delta(&tstamp, &hcrx->ccid3hcrx_tstamp_last_feedback);
872 x_recv = usecs_div(hcrx->ccid3hcrx_bytes_recv, delta);
873
874 if (x_recv == 0)
875 x_recv = hcrx->ccid3hcrx_x_recv;
876
877 tmp1 = (u64)x_recv * (u64)rtt;
878 do_div(tmp1,10000000);
879 tmp2 = (u32)tmp1;
880
881 if (!tmp2) {
882 LIMIT_NETDEBUG(KERN_WARNING "tmp2 = 0 "
883 "%s: x_recv = %u, rtt =%u\n",
884 __FUNCTION__, x_recv, rtt);
885 return ~0;
886 }
887
888 fval = (hcrx->ccid3hcrx_s * 100000) / tmp2;
889 /* do not alter order above or you will get overflow on 32 bit */
890 p = tfrc_calc_x_reverse_lookup(fval);
891 ccid3_pr_debug("%s, sk=%p, receive rate=%u bytes/s, implied "
892 "loss rate=%u\n", dccp_role(sk), sk, x_recv, p);
893
894 if (p == 0)
895 return ~0;
896 else
897 return 1000000 / p;
898 }
899
900 static void ccid3_hc_rx_update_li(struct sock *sk, u64 seq_loss, u8 win_loss)
901 {
902 struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
903 struct dccp_li_hist_entry *head;
904 u64 seq_temp;
905
906 if (list_empty(&hcrx->ccid3hcrx_li_hist)) {
907 if (!dccp_li_hist_interval_new(ccid3_li_hist,
908 &hcrx->ccid3hcrx_li_hist, seq_loss, win_loss))
909 return;
910
911 head = list_entry(hcrx->ccid3hcrx_li_hist.next,
912 struct dccp_li_hist_entry, dccplih_node);
913 head->dccplih_interval = ccid3_hc_rx_calc_first_li(sk);
914 } else {
915 struct dccp_li_hist_entry *entry;
916 struct list_head *tail;
917
918 head = list_entry(hcrx->ccid3hcrx_li_hist.next,
919 struct dccp_li_hist_entry, dccplih_node);
920 /* FIXME win count check removed as was wrong */
921 /* should make this check with receive history */
922 /* and compare there as per section 10.2 of RFC4342 */
923
924 /* new loss event detected */
925 /* calculate last interval length */
926 seq_temp = dccp_delta_seqno(head->dccplih_seqno, seq_loss);
927 entry = dccp_li_hist_entry_new(ccid3_li_hist, SLAB_ATOMIC);
928
929 if (entry == NULL) {
930 printk(KERN_CRIT "%s: out of memory\n",__FUNCTION__);
931 dump_stack();
932 return;
933 }
934
935 list_add(&entry->dccplih_node, &hcrx->ccid3hcrx_li_hist);
936
937 tail = hcrx->ccid3hcrx_li_hist.prev;
938 list_del(tail);
939 kmem_cache_free(ccid3_li_hist->dccplih_slab, tail);
940
941 /* Create the newest interval */
942 entry->dccplih_seqno = seq_loss;
943 entry->dccplih_interval = seq_temp;
944 entry->dccplih_win_count = win_loss;
945 }
946 }
947
948 static int ccid3_hc_rx_detect_loss(struct sock *sk,
949 struct dccp_rx_hist_entry *packet)
950 {
951 struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
952 struct dccp_rx_hist_entry *rx_hist = dccp_rx_hist_head(&hcrx->ccid3hcrx_hist);
953 u64 seqno = packet->dccphrx_seqno;
954 u64 tmp_seqno;
955 int loss = 0;
956 u8 ccval;
957
958
959 tmp_seqno = hcrx->ccid3hcrx_seqno_nonloss;
960
961 if (!rx_hist ||
962 follows48(packet->dccphrx_seqno, hcrx->ccid3hcrx_seqno_nonloss)) {
963 hcrx->ccid3hcrx_seqno_nonloss = seqno;
964 hcrx->ccid3hcrx_ccval_nonloss = packet->dccphrx_ccval;
965 goto detect_out;
966 }
967
968
969 while (dccp_delta_seqno(hcrx->ccid3hcrx_seqno_nonloss, seqno)
970 > TFRC_RECV_NUM_LATE_LOSS) {
971 loss = 1;
972 ccid3_hc_rx_update_li(sk, hcrx->ccid3hcrx_seqno_nonloss,
973 hcrx->ccid3hcrx_ccval_nonloss);
974 tmp_seqno = hcrx->ccid3hcrx_seqno_nonloss;
975 dccp_inc_seqno(&tmp_seqno);
976 hcrx->ccid3hcrx_seqno_nonloss = tmp_seqno;
977 dccp_inc_seqno(&tmp_seqno);
978 while (dccp_rx_hist_find_entry(&hcrx->ccid3hcrx_hist,
979 tmp_seqno, &ccval)) {
980 hcrx->ccid3hcrx_seqno_nonloss = tmp_seqno;
981 hcrx->ccid3hcrx_ccval_nonloss = ccval;
982 dccp_inc_seqno(&tmp_seqno);
983 }
984 }
985
986 /* FIXME - this code could be simplified with above while */
987 /* but works at moment */
988 if (follows48(packet->dccphrx_seqno, hcrx->ccid3hcrx_seqno_nonloss)) {
989 hcrx->ccid3hcrx_seqno_nonloss = seqno;
990 hcrx->ccid3hcrx_ccval_nonloss = packet->dccphrx_ccval;
991 }
992
993 detect_out:
994 dccp_rx_hist_add_packet(ccid3_rx_hist, &hcrx->ccid3hcrx_hist,
995 &hcrx->ccid3hcrx_li_hist, packet,
996 hcrx->ccid3hcrx_seqno_nonloss);
997 return loss;
998 }
999
1000 static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb)
1001 {
1002 struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
1003 const struct dccp_options_received *opt_recv;
1004 struct dccp_rx_hist_entry *packet;
1005 struct timeval now;
1006 u8 win_count;
1007 u32 p_prev, rtt_prev, r_sample, t_elapsed;
1008 int loss;
1009
1010 BUG_ON(hcrx == NULL ||
1011 !(hcrx->ccid3hcrx_state == TFRC_RSTATE_NO_DATA ||
1012 hcrx->ccid3hcrx_state == TFRC_RSTATE_DATA));
1013
1014 opt_recv = &dccp_sk(sk)->dccps_options_received;
1015
1016 switch (DCCP_SKB_CB(skb)->dccpd_type) {
1017 case DCCP_PKT_ACK:
1018 if (hcrx->ccid3hcrx_state == TFRC_RSTATE_NO_DATA)
1019 return;
1020 case DCCP_PKT_DATAACK:
1021 if (opt_recv->dccpor_timestamp_echo == 0)
1022 break;
1023 rtt_prev = hcrx->ccid3hcrx_rtt;
1024 dccp_timestamp(sk, &now);
1025 timeval_sub_usecs(&now, opt_recv->dccpor_timestamp_echo * 10);
1026 r_sample = timeval_usecs(&now);
1027 t_elapsed = opt_recv->dccpor_elapsed_time * 10;
1028
1029 if (unlikely(r_sample <= t_elapsed))
1030 LIMIT_NETDEBUG(KERN_WARNING "%s: r_sample=%uus, "
1031 "t_elapsed=%uus\n",
1032 __FUNCTION__, r_sample, t_elapsed);
1033 else
1034 r_sample -= t_elapsed;
1035
1036 if (hcrx->ccid3hcrx_state == TFRC_RSTATE_NO_DATA)
1037 hcrx->ccid3hcrx_rtt = r_sample;
1038 else
1039 hcrx->ccid3hcrx_rtt = (hcrx->ccid3hcrx_rtt * 9) / 10 +
1040 r_sample / 10;
1041
1042 if (rtt_prev != hcrx->ccid3hcrx_rtt)
1043 ccid3_pr_debug("%s, New RTT=%uus, elapsed time=%u\n",
1044 dccp_role(sk), hcrx->ccid3hcrx_rtt,
1045 opt_recv->dccpor_elapsed_time);
1046 break;
1047 case DCCP_PKT_DATA:
1048 break;
1049 default: /* We're not interested in other packet types, move along */
1050 return;
1051 }
1052
1053 packet = dccp_rx_hist_entry_new(ccid3_rx_hist, sk, opt_recv->dccpor_ndp,
1054 skb, SLAB_ATOMIC);
1055 if (unlikely(packet == NULL)) {
1056 LIMIT_NETDEBUG(KERN_WARNING "%s: %s, sk=%p, Not enough mem to "
1057 "add rx packet to history, consider it lost!\n",
1058 __FUNCTION__, dccp_role(sk), sk);
1059 return;
1060 }
1061
1062 win_count = packet->dccphrx_ccval;
1063
1064 loss = ccid3_hc_rx_detect_loss(sk, packet);
1065
1066 if (DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_ACK)
1067 return;
1068
1069 switch (hcrx->ccid3hcrx_state) {
1070 case TFRC_RSTATE_NO_DATA:
1071 ccid3_pr_debug("%s, sk=%p(%s), skb=%p, sending initial "
1072 "feedback\n",
1073 dccp_role(sk), sk,
1074 dccp_state_name(sk->sk_state), skb);
1075 ccid3_hc_rx_send_feedback(sk);
1076 ccid3_hc_rx_set_state(sk, TFRC_RSTATE_DATA);
1077 return;
1078 case TFRC_RSTATE_DATA:
1079 hcrx->ccid3hcrx_bytes_recv += skb->len -
1080 dccp_hdr(skb)->dccph_doff * 4;
1081 if (loss)
1082 break;
1083
1084 dccp_timestamp(sk, &now);
1085 if (timeval_delta(&now, &hcrx->ccid3hcrx_tstamp_last_ack) >=
1086 hcrx->ccid3hcrx_rtt) {
1087 hcrx->ccid3hcrx_tstamp_last_ack = now;
1088 ccid3_hc_rx_send_feedback(sk);
1089 }
1090 return;
1091 default:
1092 printk(KERN_CRIT "%s: %s, sk=%p, Illegal state (%d)!\n",
1093 __FUNCTION__, dccp_role(sk), sk, hcrx->ccid3hcrx_state);
1094 dump_stack();
1095 return;
1096 }
1097
1098 /* Dealing with packet loss */
1099 ccid3_pr_debug("%s, sk=%p(%s), data loss! Reacting...\n",
1100 dccp_role(sk), sk, dccp_state_name(sk->sk_state));
1101
1102 p_prev = hcrx->ccid3hcrx_p;
1103
1104 /* Calculate loss event rate */
1105 if (!list_empty(&hcrx->ccid3hcrx_li_hist)) {
1106 u32 i_mean = dccp_li_hist_calc_i_mean(&hcrx->ccid3hcrx_li_hist);
1107
1108 /* Scaling up by 1000000 as fixed decimal */
1109 if (i_mean != 0)
1110 hcrx->ccid3hcrx_p = 1000000 / i_mean;
1111 } else {
1112 printk(KERN_CRIT "%s: empty loss hist\n",__FUNCTION__);
1113 dump_stack();
1114 }
1115
1116 if (hcrx->ccid3hcrx_p > p_prev) {
1117 ccid3_hc_rx_send_feedback(sk);
1118 return;
1119 }
1120 }
1121
1122 static int ccid3_hc_rx_init(struct ccid *ccid, struct sock *sk)
1123 {
1124 struct dccp_sock *dp = dccp_sk(sk);
1125 struct ccid3_hc_rx_sock *hcrx = ccid_priv(ccid);
1126
1127 ccid3_pr_debug("%s, sk=%p\n", dccp_role(sk), sk);
1128
1129 if (dp->dccps_packet_size >= TFRC_MIN_PACKET_SIZE &&
1130 dp->dccps_packet_size <= TFRC_MAX_PACKET_SIZE)
1131 hcrx->ccid3hcrx_s = dp->dccps_packet_size;
1132 else
1133 hcrx->ccid3hcrx_s = TFRC_STD_PACKET_SIZE;
1134
1135 hcrx->ccid3hcrx_state = TFRC_RSTATE_NO_DATA;
1136 INIT_LIST_HEAD(&hcrx->ccid3hcrx_hist);
1137 INIT_LIST_HEAD(&hcrx->ccid3hcrx_li_hist);
1138 dccp_timestamp(sk, &hcrx->ccid3hcrx_tstamp_last_ack);
1139 hcrx->ccid3hcrx_tstamp_last_feedback = hcrx->ccid3hcrx_tstamp_last_ack;
1140 hcrx->ccid3hcrx_rtt = 5000; /* XXX 5ms for now... */
1141 return 0;
1142 }
1143
1144 static void ccid3_hc_rx_exit(struct sock *sk)
1145 {
1146 struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
1147
1148 BUG_ON(hcrx == NULL);
1149
1150 ccid3_hc_rx_set_state(sk, TFRC_RSTATE_TERM);
1151
1152 /* Empty packet history */
1153 dccp_rx_hist_purge(ccid3_rx_hist, &hcrx->ccid3hcrx_hist);
1154
1155 /* Empty loss interval history */
1156 dccp_li_hist_purge(ccid3_li_hist, &hcrx->ccid3hcrx_li_hist);
1157 }
1158
1159 static void ccid3_hc_rx_get_info(struct sock *sk, struct tcp_info *info)
1160 {
1161 const struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
1162
1163 /* Listen socks doesn't have a private CCID block */
1164 if (sk->sk_state == DCCP_LISTEN)
1165 return;
1166
1167 BUG_ON(hcrx == NULL);
1168
1169 info->tcpi_ca_state = hcrx->ccid3hcrx_state;
1170 info->tcpi_options |= TCPI_OPT_TIMESTAMPS;
1171 info->tcpi_rcv_rtt = hcrx->ccid3hcrx_rtt;
1172 }
1173
1174 static void ccid3_hc_tx_get_info(struct sock *sk, struct tcp_info *info)
1175 {
1176 const struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
1177
1178 /* Listen socks doesn't have a private CCID block */
1179 if (sk->sk_state == DCCP_LISTEN)
1180 return;
1181
1182 BUG_ON(hctx == NULL);
1183
1184 info->tcpi_rto = hctx->ccid3hctx_t_rto;
1185 info->tcpi_rtt = hctx->ccid3hctx_rtt;
1186 }
1187
1188 static int ccid3_hc_rx_getsockopt(struct sock *sk, const int optname, int len,
1189 u32 __user *optval, int __user *optlen)
1190 {
1191 const struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
1192 const void *val;
1193
1194 /* Listen socks doesn't have a private CCID block */
1195 if (sk->sk_state == DCCP_LISTEN)
1196 return -EINVAL;
1197
1198 switch (optname) {
1199 case DCCP_SOCKOPT_CCID_RX_INFO:
1200 if (len < sizeof(hcrx->ccid3hcrx_tfrc))
1201 return -EINVAL;
1202 len = sizeof(hcrx->ccid3hcrx_tfrc);
1203 val = &hcrx->ccid3hcrx_tfrc;
1204 break;
1205 default:
1206 return -ENOPROTOOPT;
1207 }
1208
1209 if (put_user(len, optlen) || copy_to_user(optval, val, len))
1210 return -EFAULT;
1211
1212 return 0;
1213 }
1214
1215 static int ccid3_hc_tx_getsockopt(struct sock *sk, const int optname, int len,
1216 u32 __user *optval, int __user *optlen)
1217 {
1218 const struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
1219 const void *val;
1220
1221 /* Listen socks doesn't have a private CCID block */
1222 if (sk->sk_state == DCCP_LISTEN)
1223 return -EINVAL;
1224
1225 switch (optname) {
1226 case DCCP_SOCKOPT_CCID_TX_INFO:
1227 if (len < sizeof(hctx->ccid3hctx_tfrc))
1228 return -EINVAL;
1229 len = sizeof(hctx->ccid3hctx_tfrc);
1230 val = &hctx->ccid3hctx_tfrc;
1231 break;
1232 default:
1233 return -ENOPROTOOPT;
1234 }
1235
1236 if (put_user(len, optlen) || copy_to_user(optval, val, len))
1237 return -EFAULT;
1238
1239 return 0;
1240 }
1241
1242 static struct ccid_operations ccid3 = {
1243 .ccid_id = DCCPC_CCID3,
1244 .ccid_name = "ccid3",
1245 .ccid_owner = THIS_MODULE,
1246 .ccid_hc_tx_obj_size = sizeof(struct ccid3_hc_tx_sock),
1247 .ccid_hc_tx_init = ccid3_hc_tx_init,
1248 .ccid_hc_tx_exit = ccid3_hc_tx_exit,
1249 .ccid_hc_tx_send_packet = ccid3_hc_tx_send_packet,
1250 .ccid_hc_tx_packet_sent = ccid3_hc_tx_packet_sent,
1251 .ccid_hc_tx_packet_recv = ccid3_hc_tx_packet_recv,
1252 .ccid_hc_tx_insert_options = ccid3_hc_tx_insert_options,
1253 .ccid_hc_tx_parse_options = ccid3_hc_tx_parse_options,
1254 .ccid_hc_rx_obj_size = sizeof(struct ccid3_hc_rx_sock),
1255 .ccid_hc_rx_init = ccid3_hc_rx_init,
1256 .ccid_hc_rx_exit = ccid3_hc_rx_exit,
1257 .ccid_hc_rx_insert_options = ccid3_hc_rx_insert_options,
1258 .ccid_hc_rx_packet_recv = ccid3_hc_rx_packet_recv,
1259 .ccid_hc_rx_get_info = ccid3_hc_rx_get_info,
1260 .ccid_hc_tx_get_info = ccid3_hc_tx_get_info,
1261 .ccid_hc_rx_getsockopt = ccid3_hc_rx_getsockopt,
1262 .ccid_hc_tx_getsockopt = ccid3_hc_tx_getsockopt,
1263 };
1264
1265 module_param(ccid3_debug, int, 0444);
1266 MODULE_PARM_DESC(ccid3_debug, "Enable debug messages");
1267
1268 static __init int ccid3_module_init(void)
1269 {
1270 int rc = -ENOBUFS;
1271
1272 ccid3_rx_hist = dccp_rx_hist_new("ccid3");
1273 if (ccid3_rx_hist == NULL)
1274 goto out;
1275
1276 ccid3_tx_hist = dccp_tx_hist_new("ccid3");
1277 if (ccid3_tx_hist == NULL)
1278 goto out_free_rx;
1279
1280 ccid3_li_hist = dccp_li_hist_new("ccid3");
1281 if (ccid3_li_hist == NULL)
1282 goto out_free_tx;
1283
1284 rc = ccid_register(&ccid3);
1285 if (rc != 0)
1286 goto out_free_loss_interval_history;
1287 out:
1288 return rc;
1289
1290 out_free_loss_interval_history:
1291 dccp_li_hist_delete(ccid3_li_hist);
1292 ccid3_li_hist = NULL;
1293 out_free_tx:
1294 dccp_tx_hist_delete(ccid3_tx_hist);
1295 ccid3_tx_hist = NULL;
1296 out_free_rx:
1297 dccp_rx_hist_delete(ccid3_rx_hist);
1298 ccid3_rx_hist = NULL;
1299 goto out;
1300 }
1301 module_init(ccid3_module_init);
1302
1303 static __exit void ccid3_module_exit(void)
1304 {
1305 ccid_unregister(&ccid3);
1306
1307 if (ccid3_tx_hist != NULL) {
1308 dccp_tx_hist_delete(ccid3_tx_hist);
1309 ccid3_tx_hist = NULL;
1310 }
1311 if (ccid3_rx_hist != NULL) {
1312 dccp_rx_hist_delete(ccid3_rx_hist);
1313 ccid3_rx_hist = NULL;
1314 }
1315 if (ccid3_li_hist != NULL) {
1316 dccp_li_hist_delete(ccid3_li_hist);
1317 ccid3_li_hist = NULL;
1318 }
1319 }
1320 module_exit(ccid3_module_exit);
1321
1322 MODULE_AUTHOR("Ian McDonald <ian.mcdonald@jandi.co.nz>, "
1323 "Arnaldo Carvalho de Melo <acme@ghostprotocols.net>");
1324 MODULE_DESCRIPTION("DCCP TFRC CCID3 CCID");
1325 MODULE_LICENSE("GPL");
1326 MODULE_ALIAS("net-dccp-ccid-3");