Commit | Line | Data |
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7c657876 ACM |
1 | /* |
2 | * net/dccp/ccids/ccid3.c | |
3 | * | |
954c2db8 | 4 | * Copyright (c) 2007 The University of Aberdeen, Scotland, UK |
b2f41ff4 IM |
5 | * Copyright (c) 2005-7 The University of Waikato, Hamilton, New Zealand. |
6 | * Copyright (c) 2005-7 Ian McDonald <ian.mcdonald@jandi.co.nz> | |
7c657876 ACM |
7 | * |
8 | * An implementation of the DCCP protocol | |
9 | * | |
10 | * This code has been developed by the University of Waikato WAND | |
11 | * research group. For further information please see http://www.wand.net.nz/ | |
7c657876 ACM |
12 | * |
13 | * This code also uses code from Lulea University, rereleased as GPL by its | |
14 | * authors: | |
15 | * Copyright (c) 2003 Nils-Erik Mattsson, Joacim Haggmark, Magnus Erixzon | |
16 | * | |
17 | * Changes to meet Linux coding standards, to make it meet latest ccid3 draft | |
18 | * and to make it work as a loadable module in the DCCP stack written by | |
19 | * Arnaldo Carvalho de Melo <acme@conectiva.com.br>. | |
20 | * | |
21 | * Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br> | |
22 | * | |
23 | * This program is free software; you can redistribute it and/or modify | |
24 | * it under the terms of the GNU General Public License as published by | |
25 | * the Free Software Foundation; either version 2 of the License, or | |
26 | * (at your option) any later version. | |
27 | * | |
28 | * This program is distributed in the hope that it will be useful, | |
29 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
30 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
31 | * GNU General Public License for more details. | |
32 | * | |
33 | * You should have received a copy of the GNU General Public License | |
34 | * along with this program; if not, write to the Free Software | |
35 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | |
36 | */ | |
7c657876 ACM |
37 | #include "../dccp.h" |
38 | #include "ccid3.h" | |
39 | ||
76fd1e87 GR |
40 | #include <asm/unaligned.h> |
41 | ||
56724aa4 GR |
42 | #ifdef CONFIG_IP_DCCP_CCID3_DEBUG |
43 | static int ccid3_debug; | |
44 | #define ccid3_pr_debug(format, a...) DCCP_PR_DEBUG(ccid3_debug, format, ##a) | |
7c657876 ACM |
45 | #else |
46 | #define ccid3_pr_debug(format, a...) | |
47 | #endif | |
48 | ||
9bf17475 GR |
49 | /* |
50 | * Transmitter Half-Connection Routines | |
51 | */ | |
56724aa4 | 52 | #ifdef CONFIG_IP_DCCP_CCID3_DEBUG |
7c657876 ACM |
53 | static const char *ccid3_tx_state_name(enum ccid3_hc_tx_states state) |
54 | { | |
55 | static char *ccid3_state_names[] = { | |
56 | [TFRC_SSTATE_NO_SENT] = "NO_SENT", | |
57 | [TFRC_SSTATE_NO_FBACK] = "NO_FBACK", | |
58 | [TFRC_SSTATE_FBACK] = "FBACK", | |
59 | [TFRC_SSTATE_TERM] = "TERM", | |
60 | }; | |
61 | ||
62 | return ccid3_state_names[state]; | |
63 | } | |
64 | #endif | |
65 | ||
c25a18ba ACM |
66 | static void ccid3_hc_tx_set_state(struct sock *sk, |
67 | enum ccid3_hc_tx_states state) | |
7c657876 | 68 | { |
59725dc2 | 69 | struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); |
7c657876 ACM |
70 | enum ccid3_hc_tx_states oldstate = hctx->ccid3hctx_state; |
71 | ||
72 | ccid3_pr_debug("%s(%p) %-8.8s -> %s\n", | |
1f2333ae ACM |
73 | dccp_role(sk), sk, ccid3_tx_state_name(oldstate), |
74 | ccid3_tx_state_name(state)); | |
7c657876 ACM |
75 | WARN_ON(state == oldstate); |
76 | hctx->ccid3hctx_state = state; | |
77 | } | |
78 | ||
a21f9f96 | 79 | /* |
6c08b2cf GR |
80 | * Compute the initial sending rate X_init in the manner of RFC 3390: |
81 | * | |
82 | * X_init = min(4 * s, max(2 * s, 4380 bytes)) / RTT | |
83 | * | |
84 | * Note that RFC 3390 uses MSS, RFC 4342 refers to RFC 3390, and rfc3448bis | |
85 | * (rev-02) clarifies the use of RFC 3390 with regard to the above formula. | |
a21f9f96 GR |
86 | * For consistency with other parts of the code, X_init is scaled by 2^6. |
87 | */ | |
88 | static inline u64 rfc3390_initial_rate(struct sock *sk) | |
89 | { | |
6c08b2cf | 90 | const struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); |
84994e16 HH |
91 | const __u32 w_init = clamp_t(__u32, 4380U, |
92 | 2 * hctx->ccid3hctx_s, 4 * hctx->ccid3hctx_s); | |
a21f9f96 | 93 | |
6c08b2cf | 94 | return scaled_div(w_init << 6, hctx->ccid3hctx_rtt); |
a21f9f96 GR |
95 | } |
96 | ||
17893bc1 | 97 | /* |
1266adee | 98 | * Recalculate t_ipi and delta (should be called whenever X changes) |
17893bc1 | 99 | */ |
c4e18dad | 100 | static void ccid3_update_send_interval(struct ccid3_hc_tx_sock *hctx) |
7c657876 | 101 | { |
1a21e49a | 102 | /* Calculate new t_ipi = s / X_inst (X_inst is in 64 * bytes/second) */ |
b2449fdc GR |
103 | hctx->ccid3hctx_t_ipi = scaled_div32(((u64)hctx->ccid3hctx_s) << 6, |
104 | hctx->ccid3hctx_x); | |
7c657876 | 105 | |
17893bc1 | 106 | /* Calculate new delta by delta = min(t_ipi / 2, t_gran / 2) */ |
1f2333ae ACM |
107 | hctx->ccid3hctx_delta = min_t(u32, hctx->ccid3hctx_t_ipi / 2, |
108 | TFRC_OPSYS_HALF_TIME_GRAN); | |
8699be7d | 109 | |
1761f7d7 | 110 | ccid3_pr_debug("t_ipi=%u, delta=%u, s=%u, X=%u\n", |
8699be7d | 111 | hctx->ccid3hctx_t_ipi, hctx->ccid3hctx_delta, |
1761f7d7 | 112 | hctx->ccid3hctx_s, (unsigned)(hctx->ccid3hctx_x >> 6)); |
8699be7d | 113 | |
7c657876 | 114 | } |
aa97efd9 | 115 | |
a5358fdc GR |
116 | static u32 ccid3_hc_tx_idle_rtt(struct ccid3_hc_tx_sock *hctx, ktime_t now) |
117 | { | |
118 | u32 delta = ktime_us_delta(now, hctx->ccid3hctx_t_last_win_count); | |
119 | ||
120 | return delta / hctx->ccid3hctx_rtt; | |
121 | } | |
122 | ||
aa97efd9 GR |
123 | /** |
124 | * ccid3_hc_tx_update_x - Update allowed sending rate X | |
125 | * @stamp: most recent time if available - can be left NULL. | |
126 | * This function tracks draft rfc3448bis, check there for latest details. | |
5c3fbb6a | 127 | * |
1a21e49a GR |
128 | * Note: X and X_recv are both stored in units of 64 * bytes/second, to support |
129 | * fine-grained resolution of sending rates. This requires scaling by 2^6 | |
130 | * throughout the code. Only X_calc is unscaled (in bytes/second). | |
131 | * | |
1a21e49a | 132 | */ |
aa97efd9 | 133 | static void ccid3_hc_tx_update_x(struct sock *sk, ktime_t *stamp) |
7c657876 | 134 | { |
59725dc2 | 135 | struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); |
0c150efb | 136 | __u64 min_rate = 2 * hctx->ccid3hctx_x_recv; |
1a21e49a | 137 | const __u64 old_x = hctx->ccid3hctx_x; |
52515e77 | 138 | ktime_t now = stamp ? *stamp : ktime_get_real(); |
7c657876 | 139 | |
0c150efb GR |
140 | /* |
141 | * Handle IDLE periods: do not reduce below RFC3390 initial sending rate | |
a5358fdc GR |
142 | * when idling [RFC 4342, 5.1]. Definition of idling is from rfc3448bis: |
143 | * a sender is idle if it has not sent anything over a 2-RTT-period. | |
0c150efb GR |
144 | * For consistency with X and X_recv, min_rate is also scaled by 2^6. |
145 | */ | |
a5358fdc | 146 | if (ccid3_hc_tx_idle_rtt(hctx, now) >= 2) { |
0c150efb GR |
147 | min_rate = rfc3390_initial_rate(sk); |
148 | min_rate = max(min_rate, 2 * hctx->ccid3hctx_x_recv); | |
149 | } | |
150 | ||
44158306 | 151 | if (hctx->ccid3hctx_p > 0) { |
1a21e49a | 152 | |
9e8efc82 | 153 | hctx->ccid3hctx_x = min(((__u64)hctx->ccid3hctx_x_calc) << 6, |
0c150efb | 154 | min_rate); |
9e8efc82 GR |
155 | hctx->ccid3hctx_x = max(hctx->ccid3hctx_x, |
156 | (((__u64)hctx->ccid3hctx_s) << 6) / | |
8109b02b | 157 | TFRC_T_MBI); |
a79ef76f | 158 | |
aa97efd9 GR |
159 | } else if (ktime_us_delta(now, hctx->ccid3hctx_t_ld) |
160 | - (s64)hctx->ccid3hctx_rtt >= 0) { | |
ac198ea8 | 161 | |
aa97efd9 GR |
162 | hctx->ccid3hctx_x = |
163 | max(min(2 * hctx->ccid3hctx_x, min_rate), | |
164 | scaled_div(((__u64)hctx->ccid3hctx_s) << 6, | |
165 | hctx->ccid3hctx_rtt)); | |
166 | hctx->ccid3hctx_t_ld = now; | |
ff586298 | 167 | } |
b6ee3d4a | 168 | |
8699be7d | 169 | if (hctx->ccid3hctx_x != old_x) { |
1761f7d7 GR |
170 | ccid3_pr_debug("X_prev=%u, X_now=%u, X_calc=%u, " |
171 | "X_recv=%u\n", (unsigned)(old_x >> 6), | |
172 | (unsigned)(hctx->ccid3hctx_x >> 6), | |
173 | hctx->ccid3hctx_x_calc, | |
174 | (unsigned)(hctx->ccid3hctx_x_recv >> 6)); | |
8699be7d | 175 | |
1266adee | 176 | ccid3_update_send_interval(hctx); |
8699be7d | 177 | } |
7c657876 ACM |
178 | } |
179 | ||
78ad713d | 180 | /* |
8109b02b ACM |
181 | * Track the mean packet size `s' (cf. RFC 4342, 5.3 and RFC 3448, 4.1) |
182 | * @len: DCCP packet payload size in bytes | |
78ad713d GR |
183 | */ |
184 | static inline void ccid3_hc_tx_update_s(struct ccid3_hc_tx_sock *hctx, int len) | |
185 | { | |
1266adee GR |
186 | const u16 old_s = hctx->ccid3hctx_s; |
187 | ||
c3ada46a | 188 | hctx->ccid3hctx_s = tfrc_ewma(hctx->ccid3hctx_s, len, 9); |
1266adee GR |
189 | |
190 | if (hctx->ccid3hctx_s != old_s) | |
191 | ccid3_update_send_interval(hctx); | |
78ad713d GR |
192 | } |
193 | ||
9f8681db | 194 | /* |
8109b02b | 195 | * Update Window Counter using the algorithm from [RFC 4342, 8.1]. |
825de27d | 196 | * As elsewhere, RTT > 0 is assumed by using dccp_sample_rtt(). |
9f8681db GR |
197 | */ |
198 | static inline void ccid3_hc_tx_update_win_count(struct ccid3_hc_tx_sock *hctx, | |
8132da4d | 199 | ktime_t now) |
9f8681db | 200 | { |
825de27d GR |
201 | u32 delta = ktime_us_delta(now, hctx->ccid3hctx_t_last_win_count), |
202 | quarter_rtts = (4 * delta) / hctx->ccid3hctx_rtt; | |
9f8681db GR |
203 | |
204 | if (quarter_rtts > 0) { | |
8132da4d | 205 | hctx->ccid3hctx_t_last_win_count = now; |
825de27d | 206 | hctx->ccid3hctx_last_win_count += min(quarter_rtts, 5U); |
9f8681db | 207 | hctx->ccid3hctx_last_win_count &= 0xF; /* mod 16 */ |
9f8681db GR |
208 | } |
209 | } | |
210 | ||
7c657876 ACM |
211 | static void ccid3_hc_tx_no_feedback_timer(unsigned long data) |
212 | { | |
213 | struct sock *sk = (struct sock *)data; | |
59725dc2 | 214 | struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); |
2a1fda6f | 215 | unsigned long t_nfb = USEC_PER_SEC / 5; |
7c657876 ACM |
216 | |
217 | bh_lock_sock(sk); | |
218 | if (sock_owned_by_user(sk)) { | |
219 | /* Try again later. */ | |
220 | /* XXX: set some sensible MIB */ | |
48e03eee | 221 | goto restart_timer; |
7c657876 ACM |
222 | } |
223 | ||
a9672411 | 224 | ccid3_pr_debug("%s(%p, state=%s) - entry \n", dccp_role(sk), sk, |
7c657876 | 225 | ccid3_tx_state_name(hctx->ccid3hctx_state)); |
a9672411 | 226 | |
52515e77 GR |
227 | if (hctx->ccid3hctx_state == TFRC_SSTATE_FBACK) |
228 | ccid3_hc_tx_set_state(sk, TFRC_SSTATE_NO_FBACK); | |
229 | else if (hctx->ccid3hctx_state != TFRC_SSTATE_NO_FBACK) | |
230 | goto out; | |
231 | ||
232 | /* | |
233 | * Determine new allowed sending rate X as per draft rfc3448bis-00, 4.4 | |
234 | */ | |
235 | if (hctx->ccid3hctx_t_rto == 0 || /* no feedback received yet */ | |
236 | hctx->ccid3hctx_p == 0) { | |
237 | ||
238 | /* halve send rate directly */ | |
9e8efc82 GR |
239 | hctx->ccid3hctx_x = max(hctx->ccid3hctx_x / 2, |
240 | (((__u64)hctx->ccid3hctx_s) << 6) / | |
241 | TFRC_T_MBI); | |
1266adee | 242 | ccid3_update_send_interval(hctx); |
52515e77 | 243 | } else { |
1f2333ae | 244 | /* |
52515e77 | 245 | * Modify the cached value of X_recv |
0c150efb | 246 | * |
52515e77 | 247 | * If (X_calc > 2 * X_recv) |
0c150efb GR |
248 | * X_recv = max(X_recv / 2, s / (2 * t_mbi)); |
249 | * Else | |
250 | * X_recv = X_calc / 4; | |
251 | * | |
252 | * Note that X_recv is scaled by 2^6 while X_calc is not | |
1f2333ae | 253 | */ |
0c150efb GR |
254 | BUG_ON(hctx->ccid3hctx_p && !hctx->ccid3hctx_x_calc); |
255 | ||
52515e77 | 256 | if (hctx->ccid3hctx_x_calc > (hctx->ccid3hctx_x_recv >> 5)) |
0c150efb GR |
257 | hctx->ccid3hctx_x_recv = |
258 | max(hctx->ccid3hctx_x_recv / 2, | |
259 | (((__u64)hctx->ccid3hctx_s) << 6) / | |
260 | (2 * TFRC_T_MBI)); | |
52515e77 | 261 | else { |
0c150efb GR |
262 | hctx->ccid3hctx_x_recv = hctx->ccid3hctx_x_calc; |
263 | hctx->ccid3hctx_x_recv <<= 4; | |
7c657876 | 264 | } |
aa97efd9 | 265 | ccid3_hc_tx_update_x(sk, NULL); |
7c657876 | 266 | } |
52515e77 GR |
267 | ccid3_pr_debug("Reduced X to %llu/64 bytes/sec\n", |
268 | (unsigned long long)hctx->ccid3hctx_x); | |
269 | ||
270 | /* | |
271 | * Set new timeout for the nofeedback timer. | |
272 | * See comments in packet_recv() regarding the value of t_RTO. | |
273 | */ | |
274 | if (unlikely(hctx->ccid3hctx_t_rto == 0)) /* no feedback yet */ | |
275 | t_nfb = TFRC_INITIAL_TIMEOUT; | |
276 | else | |
277 | t_nfb = max(hctx->ccid3hctx_t_rto, 2 * hctx->ccid3hctx_t_ipi); | |
7c657876 | 278 | |
48e03eee GR |
279 | restart_timer: |
280 | sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer, | |
c9eaf173 | 281 | jiffies + usecs_to_jiffies(t_nfb)); |
7c657876 ACM |
282 | out: |
283 | bh_unlock_sock(sk); | |
284 | sock_put(sk); | |
285 | } | |
286 | ||
7da7f456 GR |
287 | /* |
288 | * returns | |
289 | * > 0: delay (in msecs) that should pass before actually sending | |
290 | * = 0: can send immediately | |
291 | * < 0: error condition; do not send packet | |
292 | */ | |
6b57c93d | 293 | static int ccid3_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb) |
7c657876 ACM |
294 | { |
295 | struct dccp_sock *dp = dccp_sk(sk); | |
59725dc2 | 296 | struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); |
8132da4d GR |
297 | ktime_t now = ktime_get_real(); |
298 | s64 delay; | |
7c657876 | 299 | |
7c657876 | 300 | /* |
da335baf GR |
301 | * This function is called only for Data and DataAck packets. Sending |
302 | * zero-sized Data(Ack)s is theoretically possible, but for congestion | |
303 | * control this case is pathological - ignore it. | |
7c657876 | 304 | */ |
6b57c93d | 305 | if (unlikely(skb->len == 0)) |
da335baf | 306 | return -EBADMSG; |
7c657876 | 307 | |
7c657876 ACM |
308 | switch (hctx->ccid3hctx_state) { |
309 | case TFRC_SSTATE_NO_SENT: | |
1f2333ae | 310 | sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer, |
8109b02b | 311 | (jiffies + |
c9eaf173 | 312 | usecs_to_jiffies(TFRC_INITIAL_TIMEOUT))); |
7c657876 ACM |
313 | hctx->ccid3hctx_last_win_count = 0; |
314 | hctx->ccid3hctx_t_last_win_count = now; | |
90feeb95 GR |
315 | |
316 | /* Set t_0 for initial packet */ | |
7c657876 | 317 | hctx->ccid3hctx_t_nom = now; |
30833ffe GR |
318 | |
319 | hctx->ccid3hctx_s = skb->len; | |
320 | ||
321 | /* | |
322 | * Use initial RTT sample when available: recommended by erratum | |
323 | * to RFC 4342. This implements the initialisation procedure of | |
324 | * draft rfc3448bis, section 4.2. Remember, X is scaled by 2^6. | |
325 | */ | |
326 | if (dp->dccps_syn_rtt) { | |
327 | ccid3_pr_debug("SYN RTT = %uus\n", dp->dccps_syn_rtt); | |
328 | hctx->ccid3hctx_rtt = dp->dccps_syn_rtt; | |
329 | hctx->ccid3hctx_x = rfc3390_initial_rate(sk); | |
23f062af | 330 | hctx->ccid3hctx_t_ld = now; |
30833ffe | 331 | } else { |
6c08b2cf GR |
332 | /* Sender does not have RTT sample: X_pps = 1 pkt/sec */ |
333 | hctx->ccid3hctx_x = hctx->ccid3hctx_s; | |
30833ffe GR |
334 | hctx->ccid3hctx_x <<= 6; |
335 | } | |
336 | ccid3_update_send_interval(hctx); | |
337 | ||
338 | ccid3_hc_tx_set_state(sk, TFRC_SSTATE_NO_FBACK); | |
7c657876 ACM |
339 | break; |
340 | case TFRC_SSTATE_NO_FBACK: | |
341 | case TFRC_SSTATE_FBACK: | |
8132da4d | 342 | delay = ktime_us_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 | */ | |
49d66a70 | 352 | if (delay - (s64)hctx->ccid3hctx_delta >= 1000) |
8132da4d | 353 | return (u32)delay / 1000L; |
9f8681db | 354 | |
8132da4d | 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 */ | |
8132da4d GR |
367 | hctx->ccid3hctx_t_nom = ktime_add_us(hctx->ccid3hctx_t_nom, |
368 | hctx->ccid3hctx_t_ipi); | |
7da7f456 | 369 | return 0; |
7c657876 ACM |
370 | } |
371 | ||
8109b02b ACM |
372 | static 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 | |
6b57c93d | 377 | ccid3_hc_tx_update_s(hctx, len); |
7c657876 | 378 | |
276f2edc | 379 | if (tfrc_tx_hist_add(&hctx->ccid3hctx_hist, dccp_sk(sk)->dccps_gss)) |
c5a1ae9a | 380 | DCCP_CRIT("packet history - out of memory!"); |
7c657876 ACM |
381 | } |
382 | ||
383 | static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) | |
384 | { | |
59725dc2 | 385 | struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); |
7c657876 | 386 | struct ccid3_options_received *opt_recv; |
0740d49c | 387 | ktime_t now; |
2a1fda6f | 388 | unsigned long t_nfb; |
7dfee1a9 | 389 | u32 pinv, r_sample; |
1f2333ae | 390 | |
7c657876 ACM |
391 | /* we are only interested in ACKs */ |
392 | if (!(DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_ACK || | |
393 | DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_DATAACK)) | |
394 | return; | |
5bd370a6 GR |
395 | /* ... and only in the established state */ |
396 | if (hctx->ccid3hctx_state != TFRC_SSTATE_FBACK && | |
397 | hctx->ccid3hctx_state != TFRC_SSTATE_NO_FBACK) | |
398 | return; | |
7c657876 ACM |
399 | |
400 | opt_recv = &hctx->ccid3hctx_options_received; | |
5bd370a6 GR |
401 | now = ktime_get_real(); |
402 | ||
403 | /* Estimate RTT from history if ACK number is valid */ | |
404 | r_sample = tfrc_tx_hist_rtt(hctx->ccid3hctx_hist, | |
405 | DCCP_SKB_CB(skb)->dccpd_ack_seq, now); | |
406 | if (r_sample == 0) { | |
407 | DCCP_WARN("%s(%p): %s with bogus ACK-%llu\n", dccp_role(sk), sk, | |
408 | dccp_packet_name(DCCP_SKB_CB(skb)->dccpd_type), | |
409 | (unsigned long long)DCCP_SKB_CB(skb)->dccpd_ack_seq); | |
410 | return; | |
411 | } | |
7c657876 | 412 | |
5bd370a6 GR |
413 | /* Update receive rate in units of 64 * bytes/second */ |
414 | hctx->ccid3hctx_x_recv = opt_recv->ccid3or_receive_rate; | |
415 | hctx->ccid3hctx_x_recv <<= 6; | |
7c657876 | 416 | |
5bd370a6 GR |
417 | /* Update loss event rate (which is scaled by 1e6) */ |
418 | pinv = opt_recv->ccid3or_loss_event_rate; | |
419 | if (pinv == ~0U || pinv == 0) /* see RFC 4342, 8.5 */ | |
420 | hctx->ccid3hctx_p = 0; | |
421 | else /* can not exceed 100% */ | |
d8d1252f | 422 | hctx->ccid3hctx_p = scaled_div(1, pinv); |
5bd370a6 GR |
423 | /* |
424 | * Validate new RTT sample and update moving average | |
425 | */ | |
426 | r_sample = dccp_sample_rtt(sk, r_sample); | |
427 | hctx->ccid3hctx_rtt = tfrc_ewma(hctx->ccid3hctx_rtt, r_sample, 9); | |
d8d1252f GR |
428 | /* |
429 | * Update allowed sending rate X as per draft rfc3448bis-00, 4.2/3 | |
430 | */ | |
5bd370a6 | 431 | if (hctx->ccid3hctx_state == TFRC_SSTATE_NO_FBACK) { |
d8d1252f | 432 | ccid3_hc_tx_set_state(sk, TFRC_SSTATE_FBACK); |
5c3fbb6a | 433 | |
d8d1252f GR |
434 | if (hctx->ccid3hctx_t_rto == 0) { |
435 | /* | |
436 | * Initial feedback packet: Larger Initial Windows (4.2) | |
437 | */ | |
438 | hctx->ccid3hctx_x = rfc3390_initial_rate(sk); | |
439 | hctx->ccid3hctx_t_ld = now; | |
a79ef76f | 440 | |
d8d1252f | 441 | ccid3_update_send_interval(hctx); |
7c657876 | 442 | |
d8d1252f GR |
443 | goto done_computing_x; |
444 | } else if (hctx->ccid3hctx_p == 0) { | |
445 | /* | |
446 | * First feedback after nofeedback timer expiry (4.3) | |
447 | */ | |
448 | goto done_computing_x; | |
449 | } | |
450 | } | |
7c657876 | 451 | |
d8d1252f GR |
452 | /* Update sending rate (step 4 of [RFC 3448, 4.3]) */ |
453 | if (hctx->ccid3hctx_p > 0) | |
454 | hctx->ccid3hctx_x_calc = | |
5bd370a6 GR |
455 | tfrc_calc_x(hctx->ccid3hctx_s, |
456 | hctx->ccid3hctx_rtt, | |
457 | hctx->ccid3hctx_p); | |
d8d1252f | 458 | ccid3_hc_tx_update_x(sk, &now); |
7c657876 | 459 | |
d8d1252f GR |
460 | done_computing_x: |
461 | ccid3_pr_debug("%s(%p), RTT=%uus (sample=%uus), s=%u, " | |
5bd370a6 GR |
462 | "p=%u, X_calc=%u, X_recv=%u, X=%u\n", |
463 | dccp_role(sk), | |
464 | sk, hctx->ccid3hctx_rtt, r_sample, | |
465 | hctx->ccid3hctx_s, hctx->ccid3hctx_p, | |
466 | hctx->ccid3hctx_x_calc, | |
467 | (unsigned)(hctx->ccid3hctx_x_recv >> 6), | |
468 | (unsigned)(hctx->ccid3hctx_x >> 6)); | |
7c657876 | 469 | |
5bd370a6 GR |
470 | /* unschedule no feedback timer */ |
471 | sk_stop_timer(sk, &hctx->ccid3hctx_no_feedback_timer); | |
7c657876 | 472 | |
5bd370a6 GR |
473 | /* |
474 | * As we have calculated new ipi, delta, t_nom it is possible | |
475 | * that we now can send a packet, so wake up dccp_wait_for_ccid | |
476 | */ | |
477 | sk->sk_write_space(sk); | |
8c60f3fa | 478 | |
5bd370a6 GR |
479 | /* |
480 | * Update timeout interval for the nofeedback timer. | |
481 | * We use a configuration option to increase the lower bound. | |
482 | * This can help avoid triggering the nofeedback timer too | |
483 | * often ('spinning') on LANs with small RTTs. | |
484 | */ | |
485 | hctx->ccid3hctx_t_rto = max_t(u32, 4 * hctx->ccid3hctx_rtt, | |
486 | (CONFIG_IP_DCCP_CCID3_RTO * | |
487 | (USEC_PER_SEC / 1000))); | |
488 | /* | |
489 | * Schedule no feedback timer to expire in | |
490 | * max(t_RTO, 2 * s/X) = max(t_RTO, 2 * t_ipi) | |
491 | */ | |
492 | t_nfb = max(hctx->ccid3hctx_t_rto, 2 * hctx->ccid3hctx_t_ipi); | |
7c657876 | 493 | |
5bd370a6 GR |
494 | ccid3_pr_debug("%s(%p), Scheduled no feedback timer to " |
495 | "expire in %lu jiffies (%luus)\n", | |
496 | dccp_role(sk), | |
497 | sk, usecs_to_jiffies(t_nfb), t_nfb); | |
a9672411 | 498 | |
5bd370a6 GR |
499 | sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer, |
500 | jiffies + usecs_to_jiffies(t_nfb)); | |
7c657876 ACM |
501 | } |
502 | ||
7c657876 | 503 | static int ccid3_hc_tx_parse_options(struct sock *sk, unsigned char option, |
1f2333ae ACM |
504 | unsigned char len, u16 idx, |
505 | unsigned char *value) | |
7c657876 ACM |
506 | { |
507 | int rc = 0; | |
59725dc2 ACM |
508 | const struct dccp_sock *dp = dccp_sk(sk); |
509 | struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); | |
7c657876 | 510 | struct ccid3_options_received *opt_recv; |
76fd1e87 | 511 | __be32 opt_val; |
7c657876 | 512 | |
7c657876 ACM |
513 | opt_recv = &hctx->ccid3hctx_options_received; |
514 | ||
515 | if (opt_recv->ccid3or_seqno != dp->dccps_gsr) { | |
516 | opt_recv->ccid3or_seqno = dp->dccps_gsr; | |
517 | opt_recv->ccid3or_loss_event_rate = ~0; | |
518 | opt_recv->ccid3or_loss_intervals_idx = 0; | |
519 | opt_recv->ccid3or_loss_intervals_len = 0; | |
520 | opt_recv->ccid3or_receive_rate = 0; | |
521 | } | |
522 | ||
523 | switch (option) { | |
524 | case TFRC_OPT_LOSS_EVENT_RATE: | |
59d203f9 | 525 | if (unlikely(len != 4)) { |
a9672411 | 526 | DCCP_WARN("%s(%p), invalid len %d " |
59348b19 GR |
527 | "for TFRC_OPT_LOSS_EVENT_RATE\n", |
528 | dccp_role(sk), sk, len); | |
7c657876 ACM |
529 | rc = -EINVAL; |
530 | } else { | |
76fd1e87 GR |
531 | opt_val = get_unaligned((__be32 *)value); |
532 | opt_recv->ccid3or_loss_event_rate = ntohl(opt_val); | |
a9672411 | 533 | ccid3_pr_debug("%s(%p), LOSS_EVENT_RATE=%u\n", |
7c657876 ACM |
534 | dccp_role(sk), sk, |
535 | opt_recv->ccid3or_loss_event_rate); | |
536 | } | |
537 | break; | |
538 | case TFRC_OPT_LOSS_INTERVALS: | |
539 | opt_recv->ccid3or_loss_intervals_idx = idx; | |
540 | opt_recv->ccid3or_loss_intervals_len = len; | |
a9672411 | 541 | ccid3_pr_debug("%s(%p), LOSS_INTERVALS=(%u, %u)\n", |
7c657876 ACM |
542 | dccp_role(sk), sk, |
543 | opt_recv->ccid3or_loss_intervals_idx, | |
544 | opt_recv->ccid3or_loss_intervals_len); | |
545 | break; | |
546 | case TFRC_OPT_RECEIVE_RATE: | |
59d203f9 | 547 | if (unlikely(len != 4)) { |
a9672411 | 548 | DCCP_WARN("%s(%p), invalid len %d " |
59348b19 GR |
549 | "for TFRC_OPT_RECEIVE_RATE\n", |
550 | dccp_role(sk), sk, len); | |
7c657876 ACM |
551 | rc = -EINVAL; |
552 | } else { | |
76fd1e87 GR |
553 | opt_val = get_unaligned((__be32 *)value); |
554 | opt_recv->ccid3or_receive_rate = ntohl(opt_val); | |
a9672411 | 555 | ccid3_pr_debug("%s(%p), RECEIVE_RATE=%u\n", |
7c657876 ACM |
556 | dccp_role(sk), sk, |
557 | opt_recv->ccid3or_receive_rate); | |
558 | } | |
559 | break; | |
560 | } | |
561 | ||
562 | return rc; | |
563 | } | |
564 | ||
91f0ebf7 | 565 | static int ccid3_hc_tx_init(struct ccid *ccid, struct sock *sk) |
7c657876 | 566 | { |
91f0ebf7 | 567 | struct ccid3_hc_tx_sock *hctx = ccid_priv(ccid); |
7c657876 | 568 | |
7c657876 | 569 | hctx->ccid3hctx_state = TFRC_SSTATE_NO_SENT; |
276f2edc | 570 | hctx->ccid3hctx_hist = NULL; |
b24b8a24 PE |
571 | setup_timer(&hctx->ccid3hctx_no_feedback_timer, |
572 | ccid3_hc_tx_no_feedback_timer, (unsigned long)sk); | |
7c657876 ACM |
573 | |
574 | return 0; | |
575 | } | |
576 | ||
577 | static void ccid3_hc_tx_exit(struct sock *sk) | |
578 | { | |
59725dc2 | 579 | struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); |
7c657876 | 580 | |
7c657876 ACM |
581 | ccid3_hc_tx_set_state(sk, TFRC_SSTATE_TERM); |
582 | sk_stop_timer(sk, &hctx->ccid3hctx_no_feedback_timer); | |
583 | ||
276f2edc | 584 | tfrc_tx_hist_purge(&hctx->ccid3hctx_hist); |
7c657876 ACM |
585 | } |
586 | ||
9bf17475 GR |
587 | static void ccid3_hc_tx_get_info(struct sock *sk, struct tcp_info *info) |
588 | { | |
2e86908f | 589 | struct ccid3_hc_tx_sock *hctx; |
9bf17475 GR |
590 | |
591 | /* Listen socks doesn't have a private CCID block */ | |
592 | if (sk->sk_state == DCCP_LISTEN) | |
593 | return; | |
594 | ||
2e86908f | 595 | hctx = ccid3_hc_tx_sk(sk); |
9bf17475 GR |
596 | info->tcpi_rto = hctx->ccid3hctx_t_rto; |
597 | info->tcpi_rtt = hctx->ccid3hctx_rtt; | |
598 | } | |
599 | ||
600 | static int ccid3_hc_tx_getsockopt(struct sock *sk, const int optname, int len, | |
601 | u32 __user *optval, int __user *optlen) | |
602 | { | |
2e86908f | 603 | const struct ccid3_hc_tx_sock *hctx; |
9bf17475 GR |
604 | const void *val; |
605 | ||
606 | /* Listen socks doesn't have a private CCID block */ | |
607 | if (sk->sk_state == DCCP_LISTEN) | |
608 | return -EINVAL; | |
609 | ||
2e86908f | 610 | hctx = ccid3_hc_tx_sk(sk); |
9bf17475 GR |
611 | switch (optname) { |
612 | case DCCP_SOCKOPT_CCID_TX_INFO: | |
613 | if (len < sizeof(hctx->ccid3hctx_tfrc)) | |
614 | return -EINVAL; | |
615 | len = sizeof(hctx->ccid3hctx_tfrc); | |
616 | val = &hctx->ccid3hctx_tfrc; | |
617 | break; | |
618 | default: | |
619 | return -ENOPROTOOPT; | |
620 | } | |
621 | ||
622 | if (put_user(len, optlen) || copy_to_user(optval, val, len)) | |
623 | return -EFAULT; | |
624 | ||
625 | return 0; | |
626 | } | |
627 | ||
7c657876 | 628 | /* |
9bf17475 | 629 | * Receiver Half-Connection Routines |
7c657876 | 630 | */ |
b84a2189 ACM |
631 | |
632 | /* CCID3 feedback types */ | |
633 | enum ccid3_fback_type { | |
634 | CCID3_FBACK_NONE = 0, | |
635 | CCID3_FBACK_INITIAL, | |
636 | CCID3_FBACK_PERIODIC, | |
637 | CCID3_FBACK_PARAM_CHANGE | |
638 | }; | |
639 | ||
56724aa4 | 640 | #ifdef CONFIG_IP_DCCP_CCID3_DEBUG |
7c657876 ACM |
641 | static const char *ccid3_rx_state_name(enum ccid3_hc_rx_states state) |
642 | { | |
643 | static char *ccid3_rx_state_names[] = { | |
644 | [TFRC_RSTATE_NO_DATA] = "NO_DATA", | |
645 | [TFRC_RSTATE_DATA] = "DATA", | |
646 | [TFRC_RSTATE_TERM] = "TERM", | |
647 | }; | |
648 | ||
649 | return ccid3_rx_state_names[state]; | |
650 | } | |
651 | #endif | |
652 | ||
c25a18ba ACM |
653 | static void ccid3_hc_rx_set_state(struct sock *sk, |
654 | enum ccid3_hc_rx_states state) | |
7c657876 | 655 | { |
59725dc2 | 656 | struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk); |
7c657876 ACM |
657 | enum ccid3_hc_rx_states oldstate = hcrx->ccid3hcrx_state; |
658 | ||
659 | ccid3_pr_debug("%s(%p) %-8.8s -> %s\n", | |
1f2333ae ACM |
660 | dccp_role(sk), sk, ccid3_rx_state_name(oldstate), |
661 | ccid3_rx_state_name(state)); | |
7c657876 ACM |
662 | WARN_ON(state == oldstate); |
663 | hcrx->ccid3hcrx_state = state; | |
664 | } | |
665 | ||
b84a2189 ACM |
666 | static void ccid3_hc_rx_send_feedback(struct sock *sk, |
667 | const struct sk_buff *skb, | |
668 | enum ccid3_fback_type fbtype) | |
7c657876 | 669 | { |
59725dc2 | 670 | struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk); |
7c657876 | 671 | struct dccp_sock *dp = dccp_sk(sk); |
e7c23357 | 672 | ktime_t now; |
b84a2189 | 673 | s64 delta = 0; |
7c657876 | 674 | |
b84a2189 ACM |
675 | if (unlikely(hcrx->ccid3hcrx_state == TFRC_RSTATE_TERM)) |
676 | return; | |
677 | ||
e7a81c6d | 678 | now = ktime_get_real(); |
b6ee3d4a | 679 | |
b84a2189 ACM |
680 | switch (fbtype) { |
681 | case CCID3_FBACK_INITIAL: | |
7c657876 | 682 | hcrx->ccid3hcrx_x_recv = 0; |
b84a2189 | 683 | hcrx->ccid3hcrx_pinv = ~0U; /* see RFC 4342, 8.5 */ |
7c657876 | 684 | break; |
b84a2189 ACM |
685 | case CCID3_FBACK_PARAM_CHANGE: |
686 | /* | |
687 | * When parameters change (new loss or p > p_prev), we do not | |
688 | * have a reliable estimate for R_m of [RFC 3448, 6.2] and so | |
689 | * need to reuse the previous value of X_recv. However, when | |
690 | * X_recv was 0 (due to early loss), this would kill X down to | |
691 | * s/t_mbi (i.e. one packet in 64 seconds). | |
692 | * To avoid such drastic reduction, we approximate X_recv as | |
693 | * the number of bytes since last feedback. | |
694 | * This is a safe fallback, since X is bounded above by X_calc. | |
695 | */ | |
696 | if (hcrx->ccid3hcrx_x_recv > 0) | |
697 | break; | |
698 | /* fall through */ | |
699 | case CCID3_FBACK_PERIODIC: | |
700 | delta = ktime_us_delta(now, hcrx->ccid3hcrx_tstamp_last_feedback); | |
701 | if (delta <= 0) | |
702 | DCCP_BUG("delta (%ld) <= 0", (long)delta); | |
703 | else | |
704 | hcrx->ccid3hcrx_x_recv = | |
705 | scaled_div32(hcrx->ccid3hcrx_bytes_recv, delta); | |
7c657876 | 706 | break; |
b84a2189 | 707 | default: |
7c657876 ACM |
708 | return; |
709 | } | |
710 | ||
b84a2189 ACM |
711 | ccid3_pr_debug("Interval %ldusec, X_recv=%u, 1/p=%u\n", (long)delta, |
712 | hcrx->ccid3hcrx_x_recv, hcrx->ccid3hcrx_pinv); | |
7c657876 | 713 | |
b6ee3d4a | 714 | hcrx->ccid3hcrx_tstamp_last_feedback = now; |
b84a2189 | 715 | hcrx->ccid3hcrx_last_counter = dccp_hdr(skb)->dccph_ccval; |
7c657876 ACM |
716 | hcrx->ccid3hcrx_bytes_recv = 0; |
717 | ||
507d37cf | 718 | dp->dccps_hc_rx_insert_options = 1; |
7c657876 ACM |
719 | dccp_send_ack(sk); |
720 | } | |
721 | ||
2d0817d1 | 722 | static int ccid3_hc_rx_insert_options(struct sock *sk, struct sk_buff *skb) |
7c657876 | 723 | { |
2e86908f | 724 | const struct ccid3_hc_rx_sock *hcrx; |
60fe62e7 | 725 | __be32 x_recv, pinv; |
7c657876 | 726 | |
59d203f9 | 727 | if (!(sk->sk_state == DCCP_OPEN || sk->sk_state == DCCP_PARTOPEN)) |
2d0817d1 | 728 | return 0; |
7c657876 | 729 | |
2e86908f | 730 | hcrx = ccid3_hc_rx_sk(sk); |
4fded33b ACM |
731 | |
732 | if (dccp_packet_without_ack(skb)) | |
2d0817d1 ACM |
733 | return 0; |
734 | ||
4fded33b ACM |
735 | x_recv = htonl(hcrx->ccid3hcrx_x_recv); |
736 | pinv = htonl(hcrx->ccid3hcrx_pinv); | |
2d0817d1 | 737 | |
385ac2e3 | 738 | if (dccp_insert_option(sk, skb, TFRC_OPT_LOSS_EVENT_RATE, |
8109b02b | 739 | &pinv, sizeof(pinv)) || |
2d0817d1 | 740 | dccp_insert_option(sk, skb, TFRC_OPT_RECEIVE_RATE, |
8109b02b | 741 | &x_recv, sizeof(x_recv))) |
2d0817d1 ACM |
742 | return -1; |
743 | ||
744 | return 0; | |
7c657876 ACM |
745 | } |
746 | ||
954c2db8 GR |
747 | /** ccid3_first_li - Implements [RFC 3448, 6.3.1] |
748 | * | |
749 | * Determine the length of the first loss interval via inverse lookup. | |
750 | * Assume that X_recv can be computed by the throughput equation | |
751 | * s | |
752 | * X_recv = -------- | |
753 | * R * fval | |
754 | * Find some p such that f(p) = fval; return 1/p (scaled). | |
755 | */ | |
756 | static u32 ccid3_first_li(struct sock *sk) | |
757 | { | |
758 | struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk); | |
759 | u32 x_recv, p, delta; | |
760 | u64 fval; | |
761 | ||
762 | if (hcrx->ccid3hcrx_rtt == 0) { | |
763 | DCCP_WARN("No RTT estimate available, using fallback RTT\n"); | |
764 | hcrx->ccid3hcrx_rtt = DCCP_FALLBACK_RTT; | |
765 | } | |
766 | ||
767 | delta = ktime_to_us(net_timedelta(hcrx->ccid3hcrx_tstamp_last_feedback)); | |
768 | x_recv = scaled_div32(hcrx->ccid3hcrx_bytes_recv, delta); | |
769 | if (x_recv == 0) { /* would also trigger divide-by-zero */ | |
770 | DCCP_WARN("X_recv==0\n"); | |
771 | if ((x_recv = hcrx->ccid3hcrx_x_recv) == 0) { | |
772 | DCCP_BUG("stored value of X_recv is zero"); | |
773 | return ~0U; | |
774 | } | |
775 | } | |
776 | ||
777 | fval = scaled_div(hcrx->ccid3hcrx_s, hcrx->ccid3hcrx_rtt); | |
778 | fval = scaled_div32(fval, x_recv); | |
779 | p = tfrc_calc_x_reverse_lookup(fval); | |
780 | ||
781 | ccid3_pr_debug("%s(%p), receive rate=%u bytes/s, implied " | |
782 | "loss rate=%u\n", dccp_role(sk), sk, x_recv, p); | |
783 | ||
784 | return p == 0 ? ~0U : scaled_div(1, p); | |
785 | } | |
786 | ||
b84a2189 | 787 | static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb) |
7c657876 | 788 | { |
59725dc2 | 789 | struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk); |
b84a2189 ACM |
790 | enum ccid3_fback_type do_feedback = CCID3_FBACK_NONE; |
791 | const u32 ndp = dccp_sk(sk)->dccps_options_received.dccpor_ndp; | |
792 | const bool is_data_packet = dccp_data_packet(skb); | |
793 | ||
794 | if (unlikely(hcrx->ccid3hcrx_state == TFRC_RSTATE_NO_DATA)) { | |
795 | if (is_data_packet) { | |
796 | const u32 payload = skb->len - dccp_hdr(skb)->dccph_doff * 4; | |
797 | do_feedback = CCID3_FBACK_INITIAL; | |
798 | ccid3_hc_rx_set_state(sk, TFRC_RSTATE_DATA); | |
799 | hcrx->ccid3hcrx_s = payload; | |
800 | /* | |
801 | * Not necessary to update ccid3hcrx_bytes_recv here, | |
802 | * since X_recv = 0 for the first feedback packet (cf. | |
803 | * RFC 3448, 6.3) -- gerrit | |
804 | */ | |
66a377c5 | 805 | } |
b84a2189 | 806 | goto update_records; |
66a377c5 IM |
807 | } |
808 | ||
b84a2189 ACM |
809 | if (tfrc_rx_hist_duplicate(&hcrx->ccid3hcrx_hist, skb)) |
810 | return; /* done receiving */ | |
7c657876 | 811 | |
b84a2189 ACM |
812 | if (is_data_packet) { |
813 | const u32 payload = skb->len - dccp_hdr(skb)->dccph_doff * 4; | |
814 | /* | |
815 | * Update moving-average of s and the sum of received payload bytes | |
816 | */ | |
817 | hcrx->ccid3hcrx_s = tfrc_ewma(hcrx->ccid3hcrx_s, payload, 9); | |
818 | hcrx->ccid3hcrx_bytes_recv += payload; | |
7c657876 ACM |
819 | } |
820 | ||
b84a2189 ACM |
821 | /* |
822 | * Handle pending losses and otherwise check for new loss | |
823 | */ | |
954c2db8 GR |
824 | if (tfrc_rx_hist_loss_pending(&hcrx->ccid3hcrx_hist) && |
825 | tfrc_rx_handle_loss(&hcrx->ccid3hcrx_hist, | |
826 | &hcrx->ccid3hcrx_li_hist, | |
827 | skb, ndp, ccid3_first_li, sk) ) { | |
828 | do_feedback = CCID3_FBACK_PARAM_CHANGE; | |
829 | goto done_receiving; | |
830 | } | |
831 | ||
b84a2189 ACM |
832 | if (tfrc_rx_hist_new_loss_indicated(&hcrx->ccid3hcrx_hist, skb, ndp)) |
833 | goto update_records; | |
78ad713d | 834 | |
b84a2189 ACM |
835 | /* |
836 | * Handle data packets: RTT sampling and monitoring p | |
837 | */ | |
838 | if (unlikely(!is_data_packet)) | |
839 | goto update_records; | |
b6ee3d4a | 840 | |
954c2db8 | 841 | if (!tfrc_lh_is_initialised(&hcrx->ccid3hcrx_li_hist)) { |
b84a2189 ACM |
842 | const u32 sample = tfrc_rx_hist_sample_rtt(&hcrx->ccid3hcrx_hist, skb); |
843 | /* | |
844 | * Empty loss history: no loss so far, hence p stays 0. | |
845 | * Sample RTT values, since an RTT estimate is required for the | |
846 | * computation of p when the first loss occurs; RFC 3448, 6.3.1. | |
847 | */ | |
848 | if (sample != 0) | |
849 | hcrx->ccid3hcrx_rtt = tfrc_ewma(hcrx->ccid3hcrx_rtt, sample, 9); | |
954c2db8 GR |
850 | |
851 | } else if (tfrc_lh_update_i_mean(&hcrx->ccid3hcrx_li_hist, skb)) { | |
852 | /* | |
853 | * Step (3) of [RFC 3448, 6.1]: Recompute I_mean and, if I_mean | |
854 | * has decreased (resp. p has increased), send feedback now. | |
855 | */ | |
856 | do_feedback = CCID3_FBACK_PARAM_CHANGE; | |
7c657876 ACM |
857 | } |
858 | ||
b84a2189 ACM |
859 | /* |
860 | * Check if the periodic once-per-RTT feedback is due; RFC 4342, 10.3 | |
861 | */ | |
862 | if (SUB16(dccp_hdr(skb)->dccph_ccval, hcrx->ccid3hcrx_last_counter) > 3) | |
863 | do_feedback = CCID3_FBACK_PERIODIC; | |
c0996660 | 864 | |
b84a2189 ACM |
865 | update_records: |
866 | tfrc_rx_hist_add_packet(&hcrx->ccid3hcrx_hist, skb, ndp); | |
7c657876 | 867 | |
954c2db8 | 868 | done_receiving: |
b84a2189 ACM |
869 | if (do_feedback) |
870 | ccid3_hc_rx_send_feedback(sk, skb, do_feedback); | |
7c657876 ACM |
871 | } |
872 | ||
91f0ebf7 | 873 | static int ccid3_hc_rx_init(struct ccid *ccid, struct sock *sk) |
7c657876 | 874 | { |
91f0ebf7 | 875 | struct ccid3_hc_rx_sock *hcrx = ccid_priv(ccid); |
7c657876 | 876 | |
7c657876 | 877 | hcrx->ccid3hcrx_state = TFRC_RSTATE_NO_DATA; |
954c2db8 | 878 | tfrc_lh_init(&hcrx->ccid3hcrx_li_hist); |
b84a2189 | 879 | return tfrc_rx_hist_alloc(&hcrx->ccid3hcrx_hist); |
7c657876 ACM |
880 | } |
881 | ||
882 | static void ccid3_hc_rx_exit(struct sock *sk) | |
883 | { | |
59725dc2 | 884 | struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk); |
7c657876 | 885 | |
7c657876 ACM |
886 | ccid3_hc_rx_set_state(sk, TFRC_RSTATE_TERM); |
887 | ||
d58d1af0 | 888 | tfrc_rx_hist_purge(&hcrx->ccid3hcrx_hist); |
954c2db8 | 889 | tfrc_lh_cleanup(&hcrx->ccid3hcrx_li_hist); |
7c657876 ACM |
890 | } |
891 | ||
2babe1f6 ACM |
892 | static void ccid3_hc_rx_get_info(struct sock *sk, struct tcp_info *info) |
893 | { | |
2e86908f | 894 | const struct ccid3_hc_rx_sock *hcrx; |
2babe1f6 | 895 | |
59c2353d ACM |
896 | /* Listen socks doesn't have a private CCID block */ |
897 | if (sk->sk_state == DCCP_LISTEN) | |
898 | return; | |
899 | ||
2e86908f | 900 | hcrx = ccid3_hc_rx_sk(sk); |
8109b02b ACM |
901 | info->tcpi_ca_state = hcrx->ccid3hcrx_state; |
902 | info->tcpi_options |= TCPI_OPT_TIMESTAMPS; | |
903 | info->tcpi_rcv_rtt = hcrx->ccid3hcrx_rtt; | |
2babe1f6 ACM |
904 | } |
905 | ||
88f964db ACM |
906 | static int ccid3_hc_rx_getsockopt(struct sock *sk, const int optname, int len, |
907 | u32 __user *optval, int __user *optlen) | |
908 | { | |
2e86908f | 909 | const struct ccid3_hc_rx_sock *hcrx; |
8e138e79 | 910 | struct tfrc_rx_info rx_info; |
88f964db | 911 | const void *val; |
c9eaf173 | 912 | |
88f964db ACM |
913 | /* Listen socks doesn't have a private CCID block */ |
914 | if (sk->sk_state == DCCP_LISTEN) | |
915 | return -EINVAL; | |
916 | ||
2e86908f | 917 | hcrx = ccid3_hc_rx_sk(sk); |
88f964db ACM |
918 | switch (optname) { |
919 | case DCCP_SOCKOPT_CCID_RX_INFO: | |
8e138e79 | 920 | if (len < sizeof(rx_info)) |
88f964db | 921 | return -EINVAL; |
8e138e79 GR |
922 | rx_info.tfrcrx_x_recv = hcrx->ccid3hcrx_x_recv; |
923 | rx_info.tfrcrx_rtt = hcrx->ccid3hcrx_rtt; | |
924 | rx_info.tfrcrx_p = hcrx->ccid3hcrx_pinv == 0 ? ~0U : | |
925 | scaled_div(1, hcrx->ccid3hcrx_pinv); | |
926 | len = sizeof(rx_info); | |
927 | val = &rx_info; | |
88f964db ACM |
928 | break; |
929 | default: | |
930 | return -ENOPROTOOPT; | |
931 | } | |
932 | ||
933 | if (put_user(len, optlen) || copy_to_user(optval, val, len)) | |
934 | return -EFAULT; | |
935 | ||
936 | return 0; | |
937 | } | |
938 | ||
91f0ebf7 | 939 | static struct ccid_operations ccid3 = { |
3dd9a7c3 | 940 | .ccid_id = DCCPC_CCID3, |
84a97b0a | 941 | .ccid_name = "TCP-Friendly Rate Control", |
7c657876 | 942 | .ccid_owner = THIS_MODULE, |
91f0ebf7 | 943 | .ccid_hc_tx_obj_size = sizeof(struct ccid3_hc_tx_sock), |
7c657876 ACM |
944 | .ccid_hc_tx_init = ccid3_hc_tx_init, |
945 | .ccid_hc_tx_exit = ccid3_hc_tx_exit, | |
946 | .ccid_hc_tx_send_packet = ccid3_hc_tx_send_packet, | |
947 | .ccid_hc_tx_packet_sent = ccid3_hc_tx_packet_sent, | |
948 | .ccid_hc_tx_packet_recv = ccid3_hc_tx_packet_recv, | |
7c657876 | 949 | .ccid_hc_tx_parse_options = ccid3_hc_tx_parse_options, |
91f0ebf7 | 950 | .ccid_hc_rx_obj_size = sizeof(struct ccid3_hc_rx_sock), |
7c657876 ACM |
951 | .ccid_hc_rx_init = ccid3_hc_rx_init, |
952 | .ccid_hc_rx_exit = ccid3_hc_rx_exit, | |
953 | .ccid_hc_rx_insert_options = ccid3_hc_rx_insert_options, | |
954 | .ccid_hc_rx_packet_recv = ccid3_hc_rx_packet_recv, | |
2babe1f6 ACM |
955 | .ccid_hc_rx_get_info = ccid3_hc_rx_get_info, |
956 | .ccid_hc_tx_get_info = ccid3_hc_tx_get_info, | |
88f964db ACM |
957 | .ccid_hc_rx_getsockopt = ccid3_hc_rx_getsockopt, |
958 | .ccid_hc_tx_getsockopt = ccid3_hc_tx_getsockopt, | |
7c657876 | 959 | }; |
8109b02b | 960 | |
56724aa4 | 961 | #ifdef CONFIG_IP_DCCP_CCID3_DEBUG |
042d18f9 | 962 | module_param(ccid3_debug, bool, 0444); |
7c657876 | 963 | MODULE_PARM_DESC(ccid3_debug, "Enable debug messages"); |
56724aa4 | 964 | #endif |
7c657876 ACM |
965 | |
966 | static __init int ccid3_module_init(void) | |
967 | { | |
34a9e7ea | 968 | return ccid_register(&ccid3); |
7c657876 ACM |
969 | } |
970 | module_init(ccid3_module_init); | |
971 | ||
972 | static __exit void ccid3_module_exit(void) | |
973 | { | |
974 | ccid_unregister(&ccid3); | |
7c657876 ACM |
975 | } |
976 | module_exit(ccid3_module_exit); | |
977 | ||
e6bccd35 | 978 | MODULE_AUTHOR("Ian McDonald <ian.mcdonald@jandi.co.nz>, " |
1f2333ae | 979 | "Arnaldo Carvalho de Melo <acme@ghostprotocols.net>"); |
7c657876 ACM |
980 | MODULE_DESCRIPTION("DCCP TFRC CCID3 CCID"); |
981 | MODULE_LICENSE("GPL"); | |
982 | MODULE_ALIAS("net-dccp-ccid-3"); |