[CCID3]: Remove build warnings for 64bit
[deliverable/linux.git] / net / dccp / ccids / ccid3.c
CommitLineData
7c657876
ACM
1/*
2 * net/dccp/ccids/ccid3.c
3 *
4 * Copyright (c) 2005 The University of Waikato, Hamilton, New Zealand.
e6bccd35 5 * Copyright (c) 2005-6 Ian McDonald <ian.mcdonald@jandi.co.nz>
7c657876
ACM
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/
7c657876
ACM
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 */
7c657876
ACM
36#include "../ccid.h"
37#include "../dccp.h"
4524b259 38#include "lib/packet_history.h"
ae6706f0 39#include "lib/loss_interval.h"
36729c1a 40#include "lib/tfrc.h"
7c657876
ACM
41#include "ccid3.h"
42
56724aa4
GR
43#ifdef CONFIG_IP_DCCP_CCID3_DEBUG
44static int ccid3_debug;
45#define ccid3_pr_debug(format, a...) DCCP_PR_DEBUG(ccid3_debug, format, ##a)
7c657876
ACM
46#else
47#define ccid3_pr_debug(format, a...)
48#endif
49
a1d3a355
ACM
50static struct dccp_tx_hist *ccid3_tx_hist;
51static struct dccp_rx_hist *ccid3_rx_hist;
ae6706f0 52static struct dccp_li_hist *ccid3_li_hist;
7c657876 53
9bf17475
GR
54/*
55 * Transmitter Half-Connection Routines
56 */
56724aa4 57#ifdef CONFIG_IP_DCCP_CCID3_DEBUG
7c657876
ACM
58static const char *ccid3_tx_state_name(enum ccid3_hc_tx_states state)
59{
60 static char *ccid3_state_names[] = {
61 [TFRC_SSTATE_NO_SENT] = "NO_SENT",
62 [TFRC_SSTATE_NO_FBACK] = "NO_FBACK",
63 [TFRC_SSTATE_FBACK] = "FBACK",
64 [TFRC_SSTATE_TERM] = "TERM",
65 };
66
67 return ccid3_state_names[state];
68}
69#endif
70
c25a18ba
ACM
71static void ccid3_hc_tx_set_state(struct sock *sk,
72 enum ccid3_hc_tx_states state)
7c657876 73{
59725dc2 74 struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
7c657876
ACM
75 enum ccid3_hc_tx_states oldstate = hctx->ccid3hctx_state;
76
77 ccid3_pr_debug("%s(%p) %-8.8s -> %s\n",
1f2333ae
ACM
78 dccp_role(sk), sk, ccid3_tx_state_name(oldstate),
79 ccid3_tx_state_name(state));
7c657876
ACM
80 WARN_ON(state == oldstate);
81 hctx->ccid3hctx_state = state;
82}
83
17893bc1 84/*
1266adee 85 * Recalculate t_ipi and delta (should be called whenever X changes)
17893bc1 86 */
1266adee 87static inline void ccid3_update_send_interval(struct ccid3_hc_tx_sock *hctx)
7c657876 88{
1a21e49a
GR
89 /* Calculate new t_ipi = s / X_inst (X_inst is in 64 * bytes/second) */
90 hctx->ccid3hctx_t_ipi = scaled_div(hctx->ccid3hctx_s,
91 hctx->ccid3hctx_x >> 6);
7c657876 92
17893bc1 93 /* Calculate new delta by delta = min(t_ipi / 2, t_gran / 2) */
1f2333ae
ACM
94 hctx->ccid3hctx_delta = min_t(u32, hctx->ccid3hctx_t_ipi / 2,
95 TFRC_OPSYS_HALF_TIME_GRAN);
8699be7d 96
1761f7d7 97 ccid3_pr_debug("t_ipi=%u, delta=%u, s=%u, X=%u\n",
8699be7d 98 hctx->ccid3hctx_t_ipi, hctx->ccid3hctx_delta,
1761f7d7 99 hctx->ccid3hctx_s, (unsigned)(hctx->ccid3hctx_x >> 6));
8699be7d 100
7c657876 101}
7c657876
ACM
102/*
103 * Update X by
104 * If (p > 0)
5c3fbb6a 105 * X_calc = calcX(s, R, p);
7c657876
ACM
106 * X = max(min(X_calc, 2 * X_recv), s / t_mbi);
107 * Else
108 * If (now - tld >= R)
109 * X = max(min(2 * X, 2 * X_recv), s / R);
110 * tld = now;
5c3fbb6a 111 *
1a21e49a
GR
112 * Note: X and X_recv are both stored in units of 64 * bytes/second, to support
113 * fine-grained resolution of sending rates. This requires scaling by 2^6
114 * throughout the code. Only X_calc is unscaled (in bytes/second).
115 *
1a21e49a 116 */
a79ef76f
GR
117static void ccid3_hc_tx_update_x(struct sock *sk, struct timeval *now)
118
7c657876 119{
59725dc2 120 struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
1a21e49a 121 const __u64 old_x = hctx->ccid3hctx_x;
7c657876 122
44158306 123 if (hctx->ccid3hctx_p > 0) {
1a21e49a 124
9e8efc82 125 hctx->ccid3hctx_x = min(((__u64)hctx->ccid3hctx_x_calc) << 6,
8109b02b 126 hctx->ccid3hctx_x_recv * 2);
9e8efc82
GR
127 hctx->ccid3hctx_x = max(hctx->ccid3hctx_x,
128 (((__u64)hctx->ccid3hctx_s) << 6) /
8109b02b 129 TFRC_T_MBI);
a79ef76f 130
0f9e5b57 131 } else if (timeval_delta(now, &hctx->ccid3hctx_t_ld) -
8109b02b 132 (suseconds_t)hctx->ccid3hctx_rtt >= 0) {
1a21e49a 133
9e8efc82
GR
134 hctx->ccid3hctx_x =
135 max(2 * min(hctx->ccid3hctx_x, hctx->ccid3hctx_x_recv),
136 scaled_div(((__u64)hctx->ccid3hctx_s) << 6,
8109b02b 137 hctx->ccid3hctx_rtt));
a79ef76f 138 hctx->ccid3hctx_t_ld = *now;
ff586298 139 }
b6ee3d4a 140
8699be7d 141 if (hctx->ccid3hctx_x != old_x) {
1761f7d7
GR
142 ccid3_pr_debug("X_prev=%u, X_now=%u, X_calc=%u, "
143 "X_recv=%u\n", (unsigned)(old_x >> 6),
144 (unsigned)(hctx->ccid3hctx_x >> 6),
145 hctx->ccid3hctx_x_calc,
146 (unsigned)(hctx->ccid3hctx_x_recv >> 6));
8699be7d 147
1266adee 148 ccid3_update_send_interval(hctx);
8699be7d 149 }
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ACM
150}
151
78ad713d 152/*
8109b02b
ACM
153 * Track the mean packet size `s' (cf. RFC 4342, 5.3 and RFC 3448, 4.1)
154 * @len: DCCP packet payload size in bytes
78ad713d
GR
155 */
156static inline void ccid3_hc_tx_update_s(struct ccid3_hc_tx_sock *hctx, int len)
157{
1266adee
GR
158 const u16 old_s = hctx->ccid3hctx_s;
159
160 hctx->ccid3hctx_s = old_s == 0 ? len : (9 * old_s + len) / 10;
161
162 if (hctx->ccid3hctx_s != old_s)
163 ccid3_update_send_interval(hctx);
78ad713d
GR
164}
165
9f8681db 166/*
8109b02b
ACM
167 * Update Window Counter using the algorithm from [RFC 4342, 8.1].
168 * The algorithm is not applicable if RTT < 4 microseconds.
9f8681db
GR
169 */
170static inline void ccid3_hc_tx_update_win_count(struct ccid3_hc_tx_sock *hctx,
171 struct timeval *now)
172{
173 suseconds_t delta;
174 u32 quarter_rtts;
175
176 if (unlikely(hctx->ccid3hctx_rtt < 4)) /* avoid divide-by-zero */
177 return;
178
179 delta = timeval_delta(now, &hctx->ccid3hctx_t_last_win_count);
180 DCCP_BUG_ON(delta < 0);
181
182 quarter_rtts = (u32)delta / (hctx->ccid3hctx_rtt / 4);
183
184 if (quarter_rtts > 0) {
185 hctx->ccid3hctx_t_last_win_count = *now;
186 hctx->ccid3hctx_last_win_count += min_t(u32, quarter_rtts, 5);
187 hctx->ccid3hctx_last_win_count &= 0xF; /* mod 16 */
188
189 ccid3_pr_debug("now at %#X\n", hctx->ccid3hctx_last_win_count);
190 }
191}
192
7c657876
ACM
193static void ccid3_hc_tx_no_feedback_timer(unsigned long data)
194{
195 struct sock *sk = (struct sock *)data;
59725dc2 196 struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
2a1fda6f 197 unsigned long t_nfb = USEC_PER_SEC / 5;
7c657876
ACM
198
199 bh_lock_sock(sk);
200 if (sock_owned_by_user(sk)) {
201 /* Try again later. */
202 /* XXX: set some sensible MIB */
48e03eee 203 goto restart_timer;
7c657876
ACM
204 }
205
a9672411 206 ccid3_pr_debug("%s(%p, state=%s) - entry \n", dccp_role(sk), sk,
7c657876 207 ccid3_tx_state_name(hctx->ccid3hctx_state));
a9672411 208
7c657876 209 switch (hctx->ccid3hctx_state) {
7c657876 210 case TFRC_SSTATE_NO_FBACK:
a79ef76f 211 /* RFC 3448, 4.4: Halve send rate directly */
9e8efc82
GR
212 hctx->ccid3hctx_x = max(hctx->ccid3hctx_x / 2,
213 (((__u64)hctx->ccid3hctx_s) << 6) /
214 TFRC_T_MBI);
7c657876 215
a9672411
GR
216 ccid3_pr_debug("%s(%p, state=%s), updated tx rate to %u "
217 "bytes/s\n", dccp_role(sk), sk,
1f2333ae 218 ccid3_tx_state_name(hctx->ccid3hctx_state),
1a21e49a 219 (unsigned)(hctx->ccid3hctx_x >> 6));
48e03eee
GR
220 /* The value of R is still undefined and so we can not recompute
221 * the timout value. Keep initial value as per [RFC 4342, 5]. */
2a1fda6f 222 t_nfb = TFRC_INITIAL_TIMEOUT;
1266adee 223 ccid3_update_send_interval(hctx);
7c657876
ACM
224 break;
225 case TFRC_SSTATE_FBACK:
1f2333ae
ACM
226 /*
227 * Check if IDLE since last timeout and recv rate is less than
1a21e49a 228 * 4 packets (in units of 64*bytes/sec) per RTT
1f2333ae 229 */
1f2333ae 230 if (!hctx->ccid3hctx_idle ||
1a21e49a 231 (hctx->ccid3hctx_x_recv >= 4 *
8109b02b
ACM
232 scaled_div(((__u64)hctx->ccid3hctx_s) << 6,
233 hctx->ccid3hctx_rtt))) {
a79ef76f
GR
234 struct timeval now;
235
a9672411 236 ccid3_pr_debug("%s(%p, state=%s), not idle\n",
1f2333ae 237 dccp_role(sk), sk,
8109b02b 238 ccid3_tx_state_name(hctx->ccid3hctx_state));
7c657876 239
ff586298
GR
240 /*
241 * Modify the cached value of X_recv [RFC 3448, 4.4]
242 *
243 * If (p == 0 || X_calc > 2 * X_recv)
7c657876
ACM
244 * X_recv = max(X_recv / 2, s / (2 * t_mbi));
245 * Else
246 * X_recv = X_calc / 4;
1a21e49a
GR
247 *
248 * Note that X_recv is scaled by 2^6 while X_calc is not
7c657876 249 */
44158306 250 BUG_ON(hctx->ccid3hctx_p && !hctx->ccid3hctx_x_calc);
7c657876 251
44158306 252 if (hctx->ccid3hctx_p == 0 ||
8109b02b
ACM
253 (hctx->ccid3hctx_x_calc >
254 (hctx->ccid3hctx_x_recv >> 5))) {
1a21e49a
GR
255
256 hctx->ccid3hctx_x_recv =
9e8efc82
GR
257 max(hctx->ccid3hctx_x_recv / 2,
258 (((__u64)hctx->ccid3hctx_s) << 6) /
8109b02b 259 (2 * TFRC_T_MBI));
1a21e49a 260
ff586298
GR
261 if (hctx->ccid3hctx_p == 0)
262 dccp_timestamp(sk, &now);
9e8efc82
GR
263 } else {
264 hctx->ccid3hctx_x_recv = hctx->ccid3hctx_x_calc;
265 hctx->ccid3hctx_x_recv <<= 4;
266 }
ff586298 267 /* Now recalculate X [RFC 3448, 4.3, step (4)] */
a79ef76f 268 ccid3_hc_tx_update_x(sk, &now);
7c657876 269 }
6b5e633a
ACM
270 /*
271 * Schedule no feedback timer to expire in
8a508ac2
GR
272 * max(t_RTO, 2 * s/X) = max(t_RTO, 2 * t_ipi)
273 * See comments in packet_recv() regarding the value of t_RTO.
6b5e633a 274 */
8a508ac2 275 t_nfb = max(hctx->ccid3hctx_t_rto, 2 * hctx->ccid3hctx_t_ipi);
7c657876 276 break;
59348b19 277 case TFRC_SSTATE_NO_SENT:
a9672411 278 DCCP_BUG("%s(%p) - Illegal state NO_SENT", dccp_role(sk), sk);
59348b19
GR
279 /* fall through */
280 case TFRC_SSTATE_TERM:
7c657876
ACM
281 goto out;
282 }
283
7c657876 284 hctx->ccid3hctx_idle = 1;
48e03eee
GR
285
286restart_timer:
287 sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer,
c9eaf173 288 jiffies + usecs_to_jiffies(t_nfb));
7c657876
ACM
289out:
290 bh_unlock_sock(sk);
291 sock_put(sk);
292}
293
7da7f456
GR
294/*
295 * returns
296 * > 0: delay (in msecs) that should pass before actually sending
297 * = 0: can send immediately
298 * < 0: error condition; do not send packet
299 */
6b57c93d 300static int ccid3_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb)
7c657876
ACM
301{
302 struct dccp_sock *dp = dccp_sk(sk);
59725dc2 303 struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
7c657876 304 struct timeval now;
0f9e5b57 305 suseconds_t delay;
7c657876 306
59348b19 307 BUG_ON(hctx == NULL);
1f2333ae 308
7c657876 309 /*
da335baf
GR
310 * This function is called only for Data and DataAck packets. Sending
311 * zero-sized Data(Ack)s is theoretically possible, but for congestion
312 * control this case is pathological - ignore it.
7c657876 313 */
6b57c93d 314 if (unlikely(skb->len == 0))
da335baf 315 return -EBADMSG;
7c657876 316
b0e56780 317 dccp_timestamp(sk, &now);
7c657876
ACM
318
319 switch (hctx->ccid3hctx_state) {
320 case TFRC_SSTATE_NO_SENT:
1f2333ae 321 sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer,
8109b02b 322 (jiffies +
c9eaf173 323 usecs_to_jiffies(TFRC_INITIAL_TIMEOUT)));
7c657876
ACM
324 hctx->ccid3hctx_last_win_count = 0;
325 hctx->ccid3hctx_t_last_win_count = now;
326 ccid3_hc_tx_set_state(sk, TFRC_SSTATE_NO_FBACK);
7c657876 327
1a21e49a 328 /* Set initial sending rate X/s to 1pps (X is scaled by 2^6) */
1266adee 329 hctx->ccid3hctx_x = hctx->ccid3hctx_s = skb->len;
9e8efc82 330 hctx->ccid3hctx_x <<= 6;
78ad713d 331
90feeb95
GR
332 /* First timeout, according to [RFC 3448, 4.2], is 1 second */
333 hctx->ccid3hctx_t_ipi = USEC_PER_SEC;
334 /* Initial delta: minimum of 0.5 sec and t_gran/2 */
335 hctx->ccid3hctx_delta = TFRC_OPSYS_HALF_TIME_GRAN;
336
337 /* Set t_0 for initial packet */
7c657876 338 hctx->ccid3hctx_t_nom = now;
7c657876
ACM
339 break;
340 case TFRC_SSTATE_NO_FBACK:
341 case TFRC_SSTATE_FBACK:
91cf5a17 342 delay = timeval_delta(&hctx->ccid3hctx_t_nom, &now);
8699be7d 343 ccid3_pr_debug("delay=%ld\n", (long)delay);
91cf5a17 344 /*
8109b02b 345 * Scheduling of packet transmissions [RFC 3448, 4.6]
91cf5a17
GR
346 *
347 * if (t_now > t_nom - delta)
348 * // send the packet now
349 * else
350 * // send the packet in (t_nom - t_now) milliseconds.
351 */
0f9e5b57 352 if (delay - (suseconds_t)hctx->ccid3hctx_delta >= 0)
7da7f456 353 return delay / 1000L;
9f8681db
GR
354
355 ccid3_hc_tx_update_win_count(hctx, &now);
7c657876 356 break;
59348b19 357 case TFRC_SSTATE_TERM:
a9672411 358 DCCP_BUG("%s(%p) - Illegal state TERM", dccp_role(sk), sk);
7da7f456 359 return -EINVAL;
7c657876
ACM
360 }
361
7da7f456
GR
362 /* prepare to send now (add options etc.) */
363 dp->dccps_hc_tx_insert_options = 1;
e312d100
GR
364 DCCP_SKB_CB(skb)->dccpd_ccval = hctx->ccid3hctx_last_win_count;
365
366 /* set the nominal send time for the next following packet */
7da7f456
GR
367 timeval_add_usecs(&hctx->ccid3hctx_t_nom, hctx->ccid3hctx_t_ipi);
368
369 return 0;
7c657876
ACM
370}
371
8109b02b
ACM
372static void ccid3_hc_tx_packet_sent(struct sock *sk, int more,
373 unsigned int len)
7c657876 374{
59725dc2 375 struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
7c657876 376 struct timeval now;
6b57c93d 377 struct dccp_tx_hist_entry *packet;
7c657876 378
59348b19 379 BUG_ON(hctx == NULL);
7c657876 380
6b57c93d 381 ccid3_hc_tx_update_s(hctx, len);
7c657876 382
c5a1ae9a 383 packet = dccp_tx_hist_entry_new(ccid3_tx_hist, GFP_ATOMIC);
6b57c93d 384 if (unlikely(packet == NULL)) {
c5a1ae9a 385 DCCP_CRIT("packet history - out of memory!");
6b57c93d
GR
386 return;
387 }
c5a1ae9a
GR
388 dccp_tx_hist_add_entry(&hctx->ccid3hctx_hist, packet);
389
390 dccp_timestamp(sk, &now);
6b57c93d 391 packet->dccphtx_tstamp = now;
c5a1ae9a
GR
392 packet->dccphtx_seqno = dccp_sk(sk)->dccps_gss;
393 packet->dccphtx_rtt = hctx->ccid3hctx_rtt;
394 packet->dccphtx_sent = 1;
395 hctx->ccid3hctx_idle = 0;
7c657876
ACM
396}
397
398static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb)
399{
59725dc2
ACM
400 const struct dccp_sock *dp = dccp_sk(sk);
401 struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
7c657876 402 struct ccid3_options_received *opt_recv;
8c60f3fa 403 struct dccp_tx_hist_entry *packet;
b0e56780 404 struct timeval now;
2a1fda6f 405 unsigned long t_nfb;
7c657876 406 u32 pinv;
1fba78b6 407 suseconds_t r_sample, t_elapsed;
1f2333ae 408
59348b19 409 BUG_ON(hctx == NULL);
7c657876
ACM
410
411 /* we are only interested in ACKs */
412 if (!(DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_ACK ||
413 DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_DATAACK))
414 return;
415
416 opt_recv = &hctx->ccid3hctx_options_received;
417
7c657876 418 switch (hctx->ccid3hctx_state) {
7c657876
ACM
419 case TFRC_SSTATE_NO_FBACK:
420 case TFRC_SSTATE_FBACK:
5c3fbb6a 421 /* get packet from history to look up t_recvdata */
8c60f3fa 422 packet = dccp_tx_hist_find_entry(&hctx->ccid3hctx_hist,
8109b02b 423 DCCP_SKB_CB(skb)->dccpd_ack_seq);
59d203f9 424 if (unlikely(packet == NULL)) {
5c3fbb6a 425 DCCP_WARN("%s(%p), seqno %llu(%s) doesn't exist "
59348b19 426 "in history!\n", dccp_role(sk), sk,
59d203f9 427 (unsigned long long)DCCP_SKB_CB(skb)->dccpd_ack_seq,
8109b02b 428 dccp_packet_name(DCCP_SKB_CB(skb)->dccpd_type));
7c657876
ACM
429 return;
430 }
431
1a21e49a 432 /* Update receive rate in units of 64 * bytes/second */
9e8efc82
GR
433 hctx->ccid3hctx_x_recv = opt_recv->ccid3or_receive_rate;
434 hctx->ccid3hctx_x_recv <<= 6;
5c3fbb6a
GR
435
436 /* Update loss event rate */
437 pinv = opt_recv->ccid3or_loss_event_rate;
45393a66 438 if (pinv == ~0U || pinv == 0) /* see RFC 4342, 8.5 */
5c3fbb6a 439 hctx->ccid3hctx_p = 0;
45393a66 440 else /* can not exceed 100% */
8109b02b 441 hctx->ccid3hctx_p = 1000000 / pinv;
5c3fbb6a 442
b0e56780 443 dccp_timestamp(sk, &now);
5c3fbb6a
GR
444
445 /*
446 * Calculate new round trip sample as per [RFC 3448, 4.3] by
8109b02b 447 * R_sample = (now - t_recvdata) - t_elapsed
5c3fbb6a
GR
448 */
449 r_sample = timeval_delta(&now, &packet->dccphtx_tstamp);
450 t_elapsed = dp->dccps_options_received.dccpor_elapsed_time * 10;
451
0f9e5b57
GR
452 DCCP_BUG_ON(r_sample < 0);
453 if (unlikely(r_sample <= t_elapsed))
1fba78b6
ACM
454 DCCP_WARN("WARNING: r_sample=%dus <= t_elapsed=%dus\n",
455 (int)r_sample, (int)t_elapsed);
1a28599a
ACM
456 else
457 r_sample -= t_elapsed;
de553c18 458 CCID3_RTT_SANITY_CHECK(r_sample);
7c657876 459
de553c18 460 /* Update RTT estimate by
7c657876
ACM
461 * If (No feedback recv)
462 * R = R_sample;
463 * Else
464 * R = q * R + (1 - q) * R_sample;
465 *
466 * q is a constant, RFC 3448 recomments 0.9
467 */
468 if (hctx->ccid3hctx_state == TFRC_SSTATE_NO_FBACK) {
1a21e49a
GR
469 /*
470 * Larger Initial Windows [RFC 4342, sec. 5]
1a21e49a 471 */
371fe777
GR
472 __u32 w_init = min(4 * dp->dccps_mss_cache,
473 max(2 * dp->dccps_mss_cache, 4380U));
a79ef76f 474 hctx->ccid3hctx_rtt = r_sample;
9e8efc82 475 hctx->ccid3hctx_x = scaled_div(w_init << 6, r_sample);
a79ef76f
GR
476 hctx->ccid3hctx_t_ld = now;
477
1266adee 478 ccid3_update_send_interval(hctx);
7c657876 479
371fe777 480 ccid3_pr_debug("%s(%p), s=%u, MSS=%u, w_init=%u, "
1fba78b6 481 "R_sample=%dus, X=%u\n", dccp_role(sk),
0f08461e 482 sk, hctx->ccid3hctx_s,
371fe777
GR
483 dp->dccps_mss_cache,
484 w_init,
8109b02b 485 (int)r_sample,
1a21e49a 486 (unsigned)(hctx->ccid3hctx_x >> 6));
7c657876 487
5c3fbb6a
GR
488 ccid3_hc_tx_set_state(sk, TFRC_SSTATE_FBACK);
489 } else {
490 hctx->ccid3hctx_rtt = (9 * hctx->ccid3hctx_rtt +
c9eaf173 491 (u32)r_sample) / 10;
7c657876 492
ff586298
GR
493 /* Update sending rate (step 4 of [RFC 3448, 4.3]) */
494 if (hctx->ccid3hctx_p > 0)
495 hctx->ccid3hctx_x_calc =
496 tfrc_calc_x(hctx->ccid3hctx_s,
497 hctx->ccid3hctx_rtt,
498 hctx->ccid3hctx_p);
5c3fbb6a 499 ccid3_hc_tx_update_x(sk, &now);
7c657876 500
1fba78b6 501 ccid3_pr_debug("%s(%p), RTT=%uus (sample=%dus), s=%u, "
8109b02b
ACM
502 "p=%u, X_calc=%u, X_recv=%u, X=%u\n",
503 dccp_role(sk),
1fba78b6 504 sk, hctx->ccid3hctx_rtt, (int)r_sample,
5c3fbb6a
GR
505 hctx->ccid3hctx_s, hctx->ccid3hctx_p,
506 hctx->ccid3hctx_x_calc,
9e8efc82 507 (unsigned)(hctx->ccid3hctx_x_recv >> 6),
8109b02b 508 (unsigned)(hctx->ccid3hctx_x >> 6));
7c657876
ACM
509 }
510
511 /* unschedule no feedback timer */
512 sk_stop_timer(sk, &hctx->ccid3hctx_no_feedback_timer);
513
7c657876 514 /* remove all packets older than the one acked from history */
8c60f3fa
ACM
515 dccp_tx_hist_purge_older(ccid3_tx_hist,
516 &hctx->ccid3hctx_hist, packet);
c530cfb1 517 /*
8109b02b
ACM
518 * As we have calculated new ipi, delta, t_nom it is possible
519 * that we now can send a packet, so wake up dccp_wait_for_ccid
c530cfb1
ACM
520 */
521 sk->sk_write_space(sk);
8c60f3fa 522
8a508ac2
GR
523 /*
524 * Update timeout interval for the nofeedback timer.
525 * We use a configuration option to increase the lower bound.
8109b02b
ACM
526 * This can help avoid triggering the nofeedback timer too
527 * often ('spinning') on LANs with small RTTs.
8a508ac2 528 */
5d0dbc4a 529 hctx->ccid3hctx_t_rto = max_t(u32, 4 * hctx->ccid3hctx_rtt,
8a508ac2 530 CONFIG_IP_DCCP_CCID3_RTO *
8109b02b 531 (USEC_PER_SEC/1000));
1f2333ae
ACM
532 /*
533 * Schedule no feedback timer to expire in
8a508ac2 534 * max(t_RTO, 2 * s/X) = max(t_RTO, 2 * t_ipi)
1f2333ae 535 */
8a508ac2 536 t_nfb = max(hctx->ccid3hctx_t_rto, 2 * hctx->ccid3hctx_t_ipi);
7c657876 537
a9672411 538 ccid3_pr_debug("%s(%p), Scheduled no feedback timer to "
8109b02b
ACM
539 "expire in %lu jiffies (%luus)\n",
540 dccp_role(sk),
a9672411
GR
541 sk, usecs_to_jiffies(t_nfb), t_nfb);
542
543 sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer,
2a1fda6f 544 jiffies + usecs_to_jiffies(t_nfb));
7c657876
ACM
545
546 /* set idle flag */
bf58a381 547 hctx->ccid3hctx_idle = 1;
7c657876 548 break;
151a9931 549 case TFRC_SSTATE_NO_SENT: /* fall through */
5e19e3fc 550 case TFRC_SSTATE_TERM: /* ignore feedback when closing */
7c657876
ACM
551 break;
552 }
553}
554
7c657876 555static int ccid3_hc_tx_parse_options(struct sock *sk, unsigned char option,
1f2333ae
ACM
556 unsigned char len, u16 idx,
557 unsigned char *value)
7c657876
ACM
558{
559 int rc = 0;
59725dc2
ACM
560 const struct dccp_sock *dp = dccp_sk(sk);
561 struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
7c657876
ACM
562 struct ccid3_options_received *opt_recv;
563
59d203f9 564 BUG_ON(hctx == NULL);
7c657876
ACM
565
566 opt_recv = &hctx->ccid3hctx_options_received;
567
568 if (opt_recv->ccid3or_seqno != dp->dccps_gsr) {
569 opt_recv->ccid3or_seqno = dp->dccps_gsr;
570 opt_recv->ccid3or_loss_event_rate = ~0;
571 opt_recv->ccid3or_loss_intervals_idx = 0;
572 opt_recv->ccid3or_loss_intervals_len = 0;
573 opt_recv->ccid3or_receive_rate = 0;
574 }
575
576 switch (option) {
577 case TFRC_OPT_LOSS_EVENT_RATE:
59d203f9 578 if (unlikely(len != 4)) {
a9672411 579 DCCP_WARN("%s(%p), invalid len %d "
59348b19
GR
580 "for TFRC_OPT_LOSS_EVENT_RATE\n",
581 dccp_role(sk), sk, len);
7c657876
ACM
582 rc = -EINVAL;
583 } else {
8109b02b
ACM
584 opt_recv->ccid3or_loss_event_rate =
585 ntohl(*(__be32 *)value);
a9672411 586 ccid3_pr_debug("%s(%p), LOSS_EVENT_RATE=%u\n",
7c657876
ACM
587 dccp_role(sk), sk,
588 opt_recv->ccid3or_loss_event_rate);
589 }
590 break;
591 case TFRC_OPT_LOSS_INTERVALS:
592 opt_recv->ccid3or_loss_intervals_idx = idx;
593 opt_recv->ccid3or_loss_intervals_len = len;
a9672411 594 ccid3_pr_debug("%s(%p), LOSS_INTERVALS=(%u, %u)\n",
7c657876
ACM
595 dccp_role(sk), sk,
596 opt_recv->ccid3or_loss_intervals_idx,
597 opt_recv->ccid3or_loss_intervals_len);
598 break;
599 case TFRC_OPT_RECEIVE_RATE:
59d203f9 600 if (unlikely(len != 4)) {
a9672411 601 DCCP_WARN("%s(%p), invalid len %d "
59348b19
GR
602 "for TFRC_OPT_RECEIVE_RATE\n",
603 dccp_role(sk), sk, len);
7c657876
ACM
604 rc = -EINVAL;
605 } else {
8109b02b
ACM
606 opt_recv->ccid3or_receive_rate =
607 ntohl(*(__be32 *)value);
a9672411 608 ccid3_pr_debug("%s(%p), RECEIVE_RATE=%u\n",
7c657876
ACM
609 dccp_role(sk), sk,
610 opt_recv->ccid3or_receive_rate);
611 }
612 break;
613 }
614
615 return rc;
616}
617
91f0ebf7 618static int ccid3_hc_tx_init(struct ccid *ccid, struct sock *sk)
7c657876 619{
91f0ebf7 620 struct ccid3_hc_tx_sock *hctx = ccid_priv(ccid);
7c657876 621
78ad713d 622 hctx->ccid3hctx_s = 0;
fe0499ae 623 hctx->ccid3hctx_rtt = 0;
7c657876
ACM
624 hctx->ccid3hctx_state = TFRC_SSTATE_NO_SENT;
625 INIT_LIST_HEAD(&hctx->ccid3hctx_hist);
aa5d7df3 626
8109b02b
ACM
627 hctx->ccid3hctx_no_feedback_timer.function =
628 ccid3_hc_tx_no_feedback_timer;
aa5d7df3 629 hctx->ccid3hctx_no_feedback_timer.data = (unsigned long)sk;
7c657876
ACM
630 init_timer(&hctx->ccid3hctx_no_feedback_timer);
631
632 return 0;
633}
634
635static void ccid3_hc_tx_exit(struct sock *sk)
636{
59725dc2 637 struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
7c657876 638
7c657876
ACM
639 BUG_ON(hctx == NULL);
640
641 ccid3_hc_tx_set_state(sk, TFRC_SSTATE_TERM);
642 sk_stop_timer(sk, &hctx->ccid3hctx_no_feedback_timer);
643
644 /* Empty packet history */
8c60f3fa 645 dccp_tx_hist_purge(ccid3_tx_hist, &hctx->ccid3hctx_hist);
7c657876
ACM
646}
647
9bf17475
GR
648static void ccid3_hc_tx_get_info(struct sock *sk, struct tcp_info *info)
649{
650 const struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
651
652 /* Listen socks doesn't have a private CCID block */
653 if (sk->sk_state == DCCP_LISTEN)
654 return;
655
656 BUG_ON(hctx == NULL);
657
658 info->tcpi_rto = hctx->ccid3hctx_t_rto;
659 info->tcpi_rtt = hctx->ccid3hctx_rtt;
660}
661
662static int ccid3_hc_tx_getsockopt(struct sock *sk, const int optname, int len,
663 u32 __user *optval, int __user *optlen)
664{
665 const struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
666 const void *val;
667
668 /* Listen socks doesn't have a private CCID block */
669 if (sk->sk_state == DCCP_LISTEN)
670 return -EINVAL;
671
672 switch (optname) {
673 case DCCP_SOCKOPT_CCID_TX_INFO:
674 if (len < sizeof(hctx->ccid3hctx_tfrc))
675 return -EINVAL;
676 len = sizeof(hctx->ccid3hctx_tfrc);
677 val = &hctx->ccid3hctx_tfrc;
678 break;
679 default:
680 return -ENOPROTOOPT;
681 }
682
683 if (put_user(len, optlen) || copy_to_user(optval, val, len))
684 return -EFAULT;
685
686 return 0;
687}
688
7c657876 689/*
9bf17475 690 * Receiver Half-Connection Routines
7c657876 691 */
56724aa4 692#ifdef CONFIG_IP_DCCP_CCID3_DEBUG
7c657876
ACM
693static const char *ccid3_rx_state_name(enum ccid3_hc_rx_states state)
694{
695 static char *ccid3_rx_state_names[] = {
696 [TFRC_RSTATE_NO_DATA] = "NO_DATA",
697 [TFRC_RSTATE_DATA] = "DATA",
698 [TFRC_RSTATE_TERM] = "TERM",
699 };
700
701 return ccid3_rx_state_names[state];
702}
703#endif
704
c25a18ba
ACM
705static void ccid3_hc_rx_set_state(struct sock *sk,
706 enum ccid3_hc_rx_states state)
7c657876 707{
59725dc2 708 struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
7c657876
ACM
709 enum ccid3_hc_rx_states oldstate = hcrx->ccid3hcrx_state;
710
711 ccid3_pr_debug("%s(%p) %-8.8s -> %s\n",
1f2333ae
ACM
712 dccp_role(sk), sk, ccid3_rx_state_name(oldstate),
713 ccid3_rx_state_name(state));
7c657876
ACM
714 WARN_ON(state == oldstate);
715 hcrx->ccid3hcrx_state = state;
716}
717
78ad713d
GR
718static inline void ccid3_hc_rx_update_s(struct ccid3_hc_rx_sock *hcrx, int len)
719{
720 if (unlikely(len == 0)) /* don't update on empty packets (e.g. ACKs) */
721 ccid3_pr_debug("Packet payload length is 0 - not updating\n");
722 else
723 hcrx->ccid3hcrx_s = hcrx->ccid3hcrx_s == 0 ? len :
724 (9 * hcrx->ccid3hcrx_s + len) / 10;
725}
726
7c657876
ACM
727static void ccid3_hc_rx_send_feedback(struct sock *sk)
728{
59725dc2 729 struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
7c657876 730 struct dccp_sock *dp = dccp_sk(sk);
8c60f3fa 731 struct dccp_rx_hist_entry *packet;
b6ee3d4a 732 struct timeval now;
0f9e5b57 733 suseconds_t delta;
7c657876 734
a9672411 735 ccid3_pr_debug("%s(%p) - entry \n", dccp_role(sk), sk);
7c657876 736
b0e56780 737 dccp_timestamp(sk, &now);
b6ee3d4a 738
7c657876
ACM
739 switch (hcrx->ccid3hcrx_state) {
740 case TFRC_RSTATE_NO_DATA:
741 hcrx->ccid3hcrx_x_recv = 0;
742 break;
0f9e5b57
GR
743 case TFRC_RSTATE_DATA:
744 delta = timeval_delta(&now,
745 &hcrx->ccid3hcrx_tstamp_last_feedback);
746 DCCP_BUG_ON(delta < 0);
b9039a2a
GR
747 hcrx->ccid3hcrx_x_recv =
748 scaled_div32(hcrx->ccid3hcrx_bytes_recv, delta);
7c657876 749 break;
59348b19 750 case TFRC_RSTATE_TERM:
a9672411 751 DCCP_BUG("%s(%p) - Illegal state TERM", dccp_role(sk), sk);
7c657876
ACM
752 return;
753 }
754
8c60f3fa 755 packet = dccp_rx_hist_find_data_packet(&hcrx->ccid3hcrx_hist);
59d203f9 756 if (unlikely(packet == NULL)) {
a9672411 757 DCCP_WARN("%s(%p), no data packet in history!\n",
59348b19 758 dccp_role(sk), sk);
7c657876
ACM
759 return;
760 }
761
b6ee3d4a 762 hcrx->ccid3hcrx_tstamp_last_feedback = now;
66a377c5 763 hcrx->ccid3hcrx_ccval_last_counter = packet->dccphrx_ccval;
7c657876
ACM
764 hcrx->ccid3hcrx_bytes_recv = 0;
765
0f9e5b57
GR
766 /* Elapsed time information [RFC 4340, 13.2] in units of 10 * usecs */
767 delta = timeval_delta(&now, &packet->dccphrx_tstamp);
768 DCCP_BUG_ON(delta < 0);
769 hcrx->ccid3hcrx_elapsed_time = delta / 10;
45393a66 770
7c657876 771 if (hcrx->ccid3hcrx_p == 0)
45393a66
GR
772 hcrx->ccid3hcrx_pinv = ~0U; /* see RFC 4342, 8.5 */
773 else if (hcrx->ccid3hcrx_p > 1000000) {
774 DCCP_WARN("p (%u) > 100%%\n", hcrx->ccid3hcrx_p);
775 hcrx->ccid3hcrx_pinv = 1; /* use 100% in this case */
776 } else
7c657876 777 hcrx->ccid3hcrx_pinv = 1000000 / hcrx->ccid3hcrx_p;
45393a66 778
507d37cf 779 dp->dccps_hc_rx_insert_options = 1;
7c657876
ACM
780 dccp_send_ack(sk);
781}
782
2d0817d1 783static int ccid3_hc_rx_insert_options(struct sock *sk, struct sk_buff *skb)
7c657876 784{
59d203f9 785 const struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
60fe62e7 786 __be32 x_recv, pinv;
7c657876 787
59d203f9
ACM
788 BUG_ON(hcrx == NULL);
789
790 if (!(sk->sk_state == DCCP_OPEN || sk->sk_state == DCCP_PARTOPEN))
2d0817d1 791 return 0;
7c657876 792
66a377c5 793 DCCP_SKB_CB(skb)->dccpd_ccval = hcrx->ccid3hcrx_ccval_last_counter;
4fded33b
ACM
794
795 if (dccp_packet_without_ack(skb))
2d0817d1
ACM
796 return 0;
797
4fded33b
ACM
798 x_recv = htonl(hcrx->ccid3hcrx_x_recv);
799 pinv = htonl(hcrx->ccid3hcrx_pinv);
2d0817d1
ACM
800
801 if ((hcrx->ccid3hcrx_elapsed_time != 0 &&
802 dccp_insert_option_elapsed_time(sk, skb,
803 hcrx->ccid3hcrx_elapsed_time)) ||
804 dccp_insert_option_timestamp(sk, skb) ||
805 dccp_insert_option(sk, skb, TFRC_OPT_LOSS_EVENT_RATE,
8109b02b 806 &pinv, sizeof(pinv)) ||
2d0817d1 807 dccp_insert_option(sk, skb, TFRC_OPT_RECEIVE_RATE,
8109b02b 808 &x_recv, sizeof(x_recv)))
2d0817d1
ACM
809 return -1;
810
811 return 0;
7c657876
ACM
812}
813
7c657876
ACM
814/* calculate first loss interval
815 *
816 * returns estimated loss interval in usecs */
817
818static u32 ccid3_hc_rx_calc_first_li(struct sock *sk)
819{
59725dc2 820 struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
8c60f3fa 821 struct dccp_rx_hist_entry *entry, *next, *tail = NULL;
0f9e5b57
GR
822 u32 x_recv, p;
823 suseconds_t rtt, delta;
b6ee3d4a 824 struct timeval tstamp = { 0, };
7c657876
ACM
825 int interval = 0;
826 int win_count = 0;
827 int step = 0;
bfe24a6c 828 u64 fval;
7c657876 829
8c60f3fa
ACM
830 list_for_each_entry_safe(entry, next, &hcrx->ccid3hcrx_hist,
831 dccphrx_node) {
832 if (dccp_rx_hist_entry_data_packet(entry)) {
7c657876
ACM
833 tail = entry;
834
835 switch (step) {
836 case 0:
8c60f3fa 837 tstamp = entry->dccphrx_tstamp;
c1734376 838 win_count = entry->dccphrx_ccval;
7c657876
ACM
839 step = 1;
840 break;
841 case 1:
c1734376 842 interval = win_count - entry->dccphrx_ccval;
7c657876
ACM
843 if (interval < 0)
844 interval += TFRC_WIN_COUNT_LIMIT;
845 if (interval > 4)
846 goto found;
847 break;
848 }
849 }
850 }
851
59d203f9 852 if (unlikely(step == 0)) {
a9672411 853 DCCP_WARN("%s(%p), packet history has no data packets!\n",
59348b19 854 dccp_role(sk), sk);
7c657876
ACM
855 return ~0;
856 }
857
59d203f9 858 if (unlikely(interval == 0)) {
a9672411 859 DCCP_WARN("%s(%p), Could not find a win_count interval > 0."
59348b19 860 "Defaulting to 1\n", dccp_role(sk), sk);
7c657876
ACM
861 interval = 1;
862 }
863found:
66a377c5 864 if (!tail) {
59348b19 865 DCCP_CRIT("tail is null\n");
66a377c5
IM
866 return ~0;
867 }
0f9e5b57
GR
868
869 delta = timeval_delta(&tstamp, &tail->dccphrx_tstamp);
870 DCCP_BUG_ON(delta < 0);
871
872 rtt = delta * 4 / interval;
1fba78b6
ACM
873 ccid3_pr_debug("%s(%p), approximated RTT to %dus\n",
874 dccp_role(sk), sk, (int)rtt);
59348b19 875
bfe24a6c
GR
876 /*
877 * Determine the length of the first loss interval via inverse lookup.
878 * Assume that X_recv can be computed by the throughput equation
8109b02b
ACM
879 * s
880 * X_recv = --------
881 * R * fval
bfe24a6c
GR
882 * Find some p such that f(p) = fval; return 1/p [RFC 3448, 6.3.1].
883 */
884 if (rtt == 0) { /* would result in divide-by-zero */
832e3ca6
IM
885 DCCP_WARN("RTT==0\n");
886 return ~0;
59348b19 887 }
7c657876 888
b0e56780
ACM
889 dccp_timestamp(sk, &tstamp);
890 delta = timeval_delta(&tstamp, &hcrx->ccid3hcrx_tstamp_last_feedback);
0f9e5b57 891 DCCP_BUG_ON(delta <= 0);
7c657876 892
0f9e5b57 893 x_recv = scaled_div32(hcrx->ccid3hcrx_bytes_recv, delta);
bfe24a6c
GR
894 if (x_recv == 0) { /* would also trigger divide-by-zero */
895 DCCP_WARN("X_recv==0\n");
896 if ((x_recv = hcrx->ccid3hcrx_x_recv) == 0) {
897 DCCP_BUG("stored value of X_recv is zero");
832e3ca6 898 return ~0;
bfe24a6c 899 }
66a377c5
IM
900 }
901
bfe24a6c
GR
902 fval = scaled_div(hcrx->ccid3hcrx_s, rtt);
903 fval = scaled_div32(fval, x_recv);
36729c1a 904 p = tfrc_calc_x_reverse_lookup(fval);
bfe24a6c 905
a9672411 906 ccid3_pr_debug("%s(%p), receive rate=%u bytes/s, implied "
1f2333ae 907 "loss rate=%u\n", dccp_role(sk), sk, x_recv, p);
7c657876
ACM
908
909 if (p == 0)
910 return ~0;
911 else
8109b02b 912 return 1000000 / p;
7c657876
ACM
913}
914
915static void ccid3_hc_rx_update_li(struct sock *sk, u64 seq_loss, u8 win_loss)
916{
59725dc2 917 struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
fc747e82 918 struct dccp_li_hist_entry *head;
66a377c5 919 u64 seq_temp;
7c657876 920
66a377c5
IM
921 if (list_empty(&hcrx->ccid3hcrx_li_hist)) {
922 if (!dccp_li_hist_interval_new(ccid3_li_hist,
923 &hcrx->ccid3hcrx_li_hist, seq_loss, win_loss))
924 return;
7c657876 925
fc747e82
IM
926 head = list_entry(hcrx->ccid3hcrx_li_hist.next,
927 struct dccp_li_hist_entry, dccplih_node);
928 head->dccplih_interval = ccid3_hc_rx_calc_first_li(sk);
66a377c5
IM
929 } else {
930 struct dccp_li_hist_entry *entry;
931 struct list_head *tail;
932
fc747e82
IM
933 head = list_entry(hcrx->ccid3hcrx_li_hist.next,
934 struct dccp_li_hist_entry, dccplih_node);
66a377c5
IM
935 /* FIXME win count check removed as was wrong */
936 /* should make this check with receive history */
937 /* and compare there as per section 10.2 of RFC4342 */
938
939 /* new loss event detected */
940 /* calculate last interval length */
941 seq_temp = dccp_delta_seqno(head->dccplih_seqno, seq_loss);
54e6ecb2 942 entry = dccp_li_hist_entry_new(ccid3_li_hist, GFP_ATOMIC);
66a377c5
IM
943
944 if (entry == NULL) {
59348b19 945 DCCP_BUG("out of memory - can not allocate entry");
ae6706f0 946 return;
66a377c5
IM
947 }
948
949 list_add(&entry->dccplih_node, &hcrx->ccid3hcrx_li_hist);
950
951 tail = hcrx->ccid3hcrx_li_hist.prev;
952 list_del(tail);
953 kmem_cache_free(ccid3_li_hist->dccplih_slab, tail);
954
955 /* Create the newest interval */
956 entry->dccplih_seqno = seq_loss;
957 entry->dccplih_interval = seq_temp;
958 entry->dccplih_win_count = win_loss;
959 }
7c657876
ACM
960}
961
66a377c5 962static int ccid3_hc_rx_detect_loss(struct sock *sk,
c9eaf173 963 struct dccp_rx_hist_entry *packet)
7c657876 964{
59725dc2 965 struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
8109b02b
ACM
966 struct dccp_rx_hist_entry *rx_hist =
967 dccp_rx_hist_head(&hcrx->ccid3hcrx_hist);
66a377c5
IM
968 u64 seqno = packet->dccphrx_seqno;
969 u64 tmp_seqno;
970 int loss = 0;
971 u8 ccval;
972
973
974 tmp_seqno = hcrx->ccid3hcrx_seqno_nonloss;
975
976 if (!rx_hist ||
977 follows48(packet->dccphrx_seqno, hcrx->ccid3hcrx_seqno_nonloss)) {
978 hcrx->ccid3hcrx_seqno_nonloss = seqno;
979 hcrx->ccid3hcrx_ccval_nonloss = packet->dccphrx_ccval;
980 goto detect_out;
981 }
982
7c657876 983
66a377c5
IM
984 while (dccp_delta_seqno(hcrx->ccid3hcrx_seqno_nonloss, seqno)
985 > TFRC_RECV_NUM_LATE_LOSS) {
986 loss = 1;
987 ccid3_hc_rx_update_li(sk, hcrx->ccid3hcrx_seqno_nonloss,
988 hcrx->ccid3hcrx_ccval_nonloss);
989 tmp_seqno = hcrx->ccid3hcrx_seqno_nonloss;
990 dccp_inc_seqno(&tmp_seqno);
991 hcrx->ccid3hcrx_seqno_nonloss = tmp_seqno;
992 dccp_inc_seqno(&tmp_seqno);
993 while (dccp_rx_hist_find_entry(&hcrx->ccid3hcrx_hist,
994 tmp_seqno, &ccval)) {
8109b02b 995 hcrx->ccid3hcrx_seqno_nonloss = tmp_seqno;
66a377c5
IM
996 hcrx->ccid3hcrx_ccval_nonloss = ccval;
997 dccp_inc_seqno(&tmp_seqno);
998 }
999 }
1000
1001 /* FIXME - this code could be simplified with above while */
1002 /* but works at moment */
1003 if (follows48(packet->dccphrx_seqno, hcrx->ccid3hcrx_seqno_nonloss)) {
1004 hcrx->ccid3hcrx_seqno_nonloss = seqno;
1005 hcrx->ccid3hcrx_ccval_nonloss = packet->dccphrx_ccval;
1006 }
1007
1008detect_out:
1009 dccp_rx_hist_add_packet(ccid3_rx_hist, &hcrx->ccid3hcrx_hist,
1010 &hcrx->ccid3hcrx_li_hist, packet,
1011 hcrx->ccid3hcrx_seqno_nonloss);
1012 return loss;
7c657876
ACM
1013}
1014
7c657876
ACM
1015static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb)
1016{
59725dc2 1017 struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
4fded33b 1018 const struct dccp_options_received *opt_recv;
8c60f3fa 1019 struct dccp_rx_hist_entry *packet;
7c657876 1020 struct timeval now;
0f9e5b57
GR
1021 u32 p_prev, rtt_prev;
1022 suseconds_t r_sample, t_elapsed;
78ad713d 1023 int loss, payload_size;
1f2333ae 1024
59348b19 1025 BUG_ON(hcrx == NULL);
7c657876 1026
59725dc2 1027 opt_recv = &dccp_sk(sk)->dccps_options_received;
4fded33b 1028
7c657876
ACM
1029 switch (DCCP_SKB_CB(skb)->dccpd_type) {
1030 case DCCP_PKT_ACK:
1031 if (hcrx->ccid3hcrx_state == TFRC_RSTATE_NO_DATA)
1032 return;
1033 case DCCP_PKT_DATAACK:
4fded33b 1034 if (opt_recv->dccpor_timestamp_echo == 0)
7c657876 1035 break;
66a377c5 1036 rtt_prev = hcrx->ccid3hcrx_rtt;
b0e56780 1037 dccp_timestamp(sk, &now);
b3a3077d
ACM
1038 timeval_sub_usecs(&now, opt_recv->dccpor_timestamp_echo * 10);
1039 r_sample = timeval_usecs(&now);
1040 t_elapsed = opt_recv->dccpor_elapsed_time * 10;
1041
0f9e5b57 1042 DCCP_BUG_ON(r_sample < 0);
b3a3077d 1043 if (unlikely(r_sample <= t_elapsed))
0f9e5b57 1044 DCCP_WARN("r_sample=%ldus, t_elapsed=%ldus\n",
0f08461e 1045 (long)r_sample, (long)t_elapsed);
b3a3077d
ACM
1046 else
1047 r_sample -= t_elapsed;
de553c18 1048 CCID3_RTT_SANITY_CHECK(r_sample);
b3a3077d
ACM
1049
1050 if (hcrx->ccid3hcrx_state == TFRC_RSTATE_NO_DATA)
1051 hcrx->ccid3hcrx_rtt = r_sample;
1052 else
1053 hcrx->ccid3hcrx_rtt = (hcrx->ccid3hcrx_rtt * 9) / 10 +
1054 r_sample / 10;
1055
66a377c5 1056 if (rtt_prev != hcrx->ccid3hcrx_rtt)
a9672411
GR
1057 ccid3_pr_debug("%s(%p), New RTT=%uus, elapsed time=%u\n",
1058 dccp_role(sk), sk, hcrx->ccid3hcrx_rtt,
4fded33b 1059 opt_recv->dccpor_elapsed_time);
7c657876
ACM
1060 break;
1061 case DCCP_PKT_DATA:
1062 break;
59d203f9 1063 default: /* We're not interested in other packet types, move along */
7c657876
ACM
1064 return;
1065 }
1066
b0e56780 1067 packet = dccp_rx_hist_entry_new(ccid3_rx_hist, sk, opt_recv->dccpor_ndp,
54e6ecb2 1068 skb, GFP_ATOMIC);
59d203f9 1069 if (unlikely(packet == NULL)) {
a9672411 1070 DCCP_WARN("%s(%p), Not enough mem to add rx packet "
59348b19 1071 "to history, consider it lost!\n", dccp_role(sk), sk);
7c657876
ACM
1072 return;
1073 }
1074
66a377c5 1075 loss = ccid3_hc_rx_detect_loss(sk, packet);
7c657876
ACM
1076
1077 if (DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_ACK)
1078 return;
1079
78ad713d
GR
1080 payload_size = skb->len - dccp_hdr(skb)->dccph_doff * 4;
1081 ccid3_hc_rx_update_s(hcrx, payload_size);
1082
7c657876
ACM
1083 switch (hcrx->ccid3hcrx_state) {
1084 case TFRC_RSTATE_NO_DATA:
a9672411
GR
1085 ccid3_pr_debug("%s(%p, state=%s), skb=%p, sending initial "
1086 "feedback\n", dccp_role(sk), sk,
1f2333ae 1087 dccp_state_name(sk->sk_state), skb);
7c657876
ACM
1088 ccid3_hc_rx_send_feedback(sk);
1089 ccid3_hc_rx_set_state(sk, TFRC_RSTATE_DATA);
1090 return;
1091 case TFRC_RSTATE_DATA:
78ad713d 1092 hcrx->ccid3hcrx_bytes_recv += payload_size;
66a377c5 1093 if (loss)
b6ee3d4a
ACM
1094 break;
1095
b0e56780 1096 dccp_timestamp(sk, &now);
8109b02b
ACM
1097 if ((timeval_delta(&now, &hcrx->ccid3hcrx_tstamp_last_ack) -
1098 (suseconds_t)hcrx->ccid3hcrx_rtt) >= 0) {
b6ee3d4a
ACM
1099 hcrx->ccid3hcrx_tstamp_last_ack = now;
1100 ccid3_hc_rx_send_feedback(sk);
7c657876 1101 }
b6ee3d4a 1102 return;
59348b19 1103 case TFRC_RSTATE_TERM:
a9672411 1104 DCCP_BUG("%s(%p) - Illegal state TERM", dccp_role(sk), sk);
7c657876
ACM
1105 return;
1106 }
1107
1108 /* Dealing with packet loss */
a9672411 1109 ccid3_pr_debug("%s(%p, state=%s), data loss! Reacting...\n",
4fded33b 1110 dccp_role(sk), sk, dccp_state_name(sk->sk_state));
7c657876 1111
7c657876 1112 p_prev = hcrx->ccid3hcrx_p;
c9eaf173 1113
7c657876 1114 /* Calculate loss event rate */
c0996660
IM
1115 if (!list_empty(&hcrx->ccid3hcrx_li_hist)) {
1116 u32 i_mean = dccp_li_hist_calc_i_mean(&hcrx->ccid3hcrx_li_hist);
1117
7c657876 1118 /* Scaling up by 1000000 as fixed decimal */
c0996660
IM
1119 if (i_mean != 0)
1120 hcrx->ccid3hcrx_p = 1000000 / i_mean;
59348b19
GR
1121 } else
1122 DCCP_BUG("empty loss history");
7c657876
ACM
1123
1124 if (hcrx->ccid3hcrx_p > p_prev) {
1125 ccid3_hc_rx_send_feedback(sk);
1126 return;
1127 }
1128}
1129
91f0ebf7 1130static int ccid3_hc_rx_init(struct ccid *ccid, struct sock *sk)
7c657876 1131{
91f0ebf7 1132 struct ccid3_hc_rx_sock *hcrx = ccid_priv(ccid);
7c657876 1133
a9672411 1134 ccid3_pr_debug("entry\n");
7c657876 1135
7c657876
ACM
1136 hcrx->ccid3hcrx_state = TFRC_RSTATE_NO_DATA;
1137 INIT_LIST_HEAD(&hcrx->ccid3hcrx_hist);
ae6706f0 1138 INIT_LIST_HEAD(&hcrx->ccid3hcrx_li_hist);
b0e56780 1139 dccp_timestamp(sk, &hcrx->ccid3hcrx_tstamp_last_ack);
954ee31f 1140 hcrx->ccid3hcrx_tstamp_last_feedback = hcrx->ccid3hcrx_tstamp_last_ack;
78ad713d 1141 hcrx->ccid3hcrx_s = 0;
fe0499ae 1142 hcrx->ccid3hcrx_rtt = 0;
7c657876
ACM
1143 return 0;
1144}
1145
1146static void ccid3_hc_rx_exit(struct sock *sk)
1147{
59725dc2 1148 struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
7c657876 1149
59d203f9 1150 BUG_ON(hcrx == NULL);
7c657876
ACM
1151
1152 ccid3_hc_rx_set_state(sk, TFRC_RSTATE_TERM);
1153
1154 /* Empty packet history */
8c60f3fa 1155 dccp_rx_hist_purge(ccid3_rx_hist, &hcrx->ccid3hcrx_hist);
7c657876
ACM
1156
1157 /* Empty loss interval history */
ae6706f0 1158 dccp_li_hist_purge(ccid3_li_hist, &hcrx->ccid3hcrx_li_hist);
7c657876
ACM
1159}
1160
2babe1f6
ACM
1161static void ccid3_hc_rx_get_info(struct sock *sk, struct tcp_info *info)
1162{
59725dc2 1163 const struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
2babe1f6 1164
59c2353d
ACM
1165 /* Listen socks doesn't have a private CCID block */
1166 if (sk->sk_state == DCCP_LISTEN)
1167 return;
1168
59d203f9 1169 BUG_ON(hcrx == NULL);
2babe1f6 1170
8109b02b
ACM
1171 info->tcpi_ca_state = hcrx->ccid3hcrx_state;
1172 info->tcpi_options |= TCPI_OPT_TIMESTAMPS;
1173 info->tcpi_rcv_rtt = hcrx->ccid3hcrx_rtt;
2babe1f6
ACM
1174}
1175
88f964db
ACM
1176static int ccid3_hc_rx_getsockopt(struct sock *sk, const int optname, int len,
1177 u32 __user *optval, int __user *optlen)
1178{
1179 const struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
1180 const void *val;
c9eaf173 1181
88f964db
ACM
1182 /* Listen socks doesn't have a private CCID block */
1183 if (sk->sk_state == DCCP_LISTEN)
1184 return -EINVAL;
1185
1186 switch (optname) {
1187 case DCCP_SOCKOPT_CCID_RX_INFO:
1188 if (len < sizeof(hcrx->ccid3hcrx_tfrc))
1189 return -EINVAL;
1190 len = sizeof(hcrx->ccid3hcrx_tfrc);
1191 val = &hcrx->ccid3hcrx_tfrc;
1192 break;
1193 default:
1194 return -ENOPROTOOPT;
1195 }
1196
1197 if (put_user(len, optlen) || copy_to_user(optval, val, len))
1198 return -EFAULT;
1199
1200 return 0;
1201}
1202
91f0ebf7 1203static struct ccid_operations ccid3 = {
3dd9a7c3 1204 .ccid_id = DCCPC_CCID3,
7c657876
ACM
1205 .ccid_name = "ccid3",
1206 .ccid_owner = THIS_MODULE,
91f0ebf7 1207 .ccid_hc_tx_obj_size = sizeof(struct ccid3_hc_tx_sock),
7c657876
ACM
1208 .ccid_hc_tx_init = ccid3_hc_tx_init,
1209 .ccid_hc_tx_exit = ccid3_hc_tx_exit,
1210 .ccid_hc_tx_send_packet = ccid3_hc_tx_send_packet,
1211 .ccid_hc_tx_packet_sent = ccid3_hc_tx_packet_sent,
1212 .ccid_hc_tx_packet_recv = ccid3_hc_tx_packet_recv,
7c657876 1213 .ccid_hc_tx_parse_options = ccid3_hc_tx_parse_options,
91f0ebf7 1214 .ccid_hc_rx_obj_size = sizeof(struct ccid3_hc_rx_sock),
7c657876
ACM
1215 .ccid_hc_rx_init = ccid3_hc_rx_init,
1216 .ccid_hc_rx_exit = ccid3_hc_rx_exit,
1217 .ccid_hc_rx_insert_options = ccid3_hc_rx_insert_options,
1218 .ccid_hc_rx_packet_recv = ccid3_hc_rx_packet_recv,
2babe1f6
ACM
1219 .ccid_hc_rx_get_info = ccid3_hc_rx_get_info,
1220 .ccid_hc_tx_get_info = ccid3_hc_tx_get_info,
88f964db
ACM
1221 .ccid_hc_rx_getsockopt = ccid3_hc_rx_getsockopt,
1222 .ccid_hc_tx_getsockopt = ccid3_hc_tx_getsockopt,
7c657876 1223};
8109b02b 1224
56724aa4 1225#ifdef CONFIG_IP_DCCP_CCID3_DEBUG
7c657876
ACM
1226module_param(ccid3_debug, int, 0444);
1227MODULE_PARM_DESC(ccid3_debug, "Enable debug messages");
56724aa4 1228#endif
7c657876
ACM
1229
1230static __init int ccid3_module_init(void)
1231{
8c60f3fa 1232 int rc = -ENOBUFS;
7c657876 1233
8c60f3fa
ACM
1234 ccid3_rx_hist = dccp_rx_hist_new("ccid3");
1235 if (ccid3_rx_hist == NULL)
7c657876
ACM
1236 goto out;
1237
8c60f3fa
ACM
1238 ccid3_tx_hist = dccp_tx_hist_new("ccid3");
1239 if (ccid3_tx_hist == NULL)
1240 goto out_free_rx;
7c657876 1241
ae6706f0
ACM
1242 ccid3_li_hist = dccp_li_hist_new("ccid3");
1243 if (ccid3_li_hist == NULL)
8c60f3fa 1244 goto out_free_tx;
7c657876
ACM
1245
1246 rc = ccid_register(&ccid3);
8109b02b 1247 if (rc != 0)
7c657876 1248 goto out_free_loss_interval_history;
7c657876
ACM
1249out:
1250 return rc;
8c60f3fa 1251
7c657876 1252out_free_loss_interval_history:
ae6706f0
ACM
1253 dccp_li_hist_delete(ccid3_li_hist);
1254 ccid3_li_hist = NULL;
8c60f3fa
ACM
1255out_free_tx:
1256 dccp_tx_hist_delete(ccid3_tx_hist);
1257 ccid3_tx_hist = NULL;
1258out_free_rx:
1259 dccp_rx_hist_delete(ccid3_rx_hist);
1260 ccid3_rx_hist = NULL;
7c657876
ACM
1261 goto out;
1262}
1263module_init(ccid3_module_init);
1264
1265static __exit void ccid3_module_exit(void)
1266{
1267 ccid_unregister(&ccid3);
1268
8c60f3fa
ACM
1269 if (ccid3_tx_hist != NULL) {
1270 dccp_tx_hist_delete(ccid3_tx_hist);
1271 ccid3_tx_hist = NULL;
7c657876 1272 }
8c60f3fa
ACM
1273 if (ccid3_rx_hist != NULL) {
1274 dccp_rx_hist_delete(ccid3_rx_hist);
1275 ccid3_rx_hist = NULL;
7c657876 1276 }
ae6706f0
ACM
1277 if (ccid3_li_hist != NULL) {
1278 dccp_li_hist_delete(ccid3_li_hist);
1279 ccid3_li_hist = NULL;
7c657876
ACM
1280 }
1281}
1282module_exit(ccid3_module_exit);
1283
e6bccd35 1284MODULE_AUTHOR("Ian McDonald <ian.mcdonald@jandi.co.nz>, "
1f2333ae 1285 "Arnaldo Carvalho de Melo <acme@ghostprotocols.net>");
7c657876
ACM
1286MODULE_DESCRIPTION("DCCP TFRC CCID3 CCID");
1287MODULE_LICENSE("GPL");
1288MODULE_ALIAS("net-dccp-ccid-3");
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