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Commit | Line | Data |
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7c657876 | 1 | /* |
954c2db8 | 2 | * Copyright (c) 2007 The University of Aberdeen, Scotland, UK |
b2f41ff4 IM |
3 | * Copyright (c) 2005-7 The University of Waikato, Hamilton, New Zealand. |
4 | * Copyright (c) 2005-7 Ian McDonald <ian.mcdonald@jandi.co.nz> | |
7c657876 ACM |
5 | * |
6 | * An implementation of the DCCP protocol | |
7 | * | |
8 | * This code has been developed by the University of Waikato WAND | |
9 | * research group. For further information please see http://www.wand.net.nz/ | |
7c657876 ACM |
10 | * |
11 | * This code also uses code from Lulea University, rereleased as GPL by its | |
12 | * authors: | |
13 | * Copyright (c) 2003 Nils-Erik Mattsson, Joacim Haggmark, Magnus Erixzon | |
14 | * | |
15 | * Changes to meet Linux coding standards, to make it meet latest ccid3 draft | |
16 | * and to make it work as a loadable module in the DCCP stack written by | |
17 | * Arnaldo Carvalho de Melo <acme@conectiva.com.br>. | |
18 | * | |
19 | * Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br> | |
20 | * | |
21 | * This program is free software; you can redistribute it and/or modify | |
22 | * it under the terms of the GNU General Public License as published by | |
23 | * the Free Software Foundation; either version 2 of the License, or | |
24 | * (at your option) any later version. | |
25 | * | |
26 | * This program is distributed in the hope that it will be useful, | |
27 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
28 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
29 | * GNU General Public License for more details. | |
30 | * | |
31 | * You should have received a copy of the GNU General Public License | |
32 | * along with this program; if not, write to the Free Software | |
33 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | |
34 | */ | |
7c657876 ACM |
35 | #include "../dccp.h" |
36 | #include "ccid3.h" | |
37 | ||
76fd1e87 GR |
38 | #include <asm/unaligned.h> |
39 | ||
56724aa4 GR |
40 | #ifdef CONFIG_IP_DCCP_CCID3_DEBUG |
41 | static int ccid3_debug; | |
42 | #define ccid3_pr_debug(format, a...) DCCP_PR_DEBUG(ccid3_debug, format, ##a) | |
7c657876 ACM |
43 | #else |
44 | #define ccid3_pr_debug(format, a...) | |
45 | #endif | |
46 | ||
9bf17475 GR |
47 | /* |
48 | * Transmitter Half-Connection Routines | |
49 | */ | |
410e27a4 GR |
50 | #ifdef CONFIG_IP_DCCP_CCID3_DEBUG |
51 | static const char *ccid3_tx_state_name(enum ccid3_hc_tx_states state) | |
52 | { | |
36cbd3dc | 53 | static const char *const ccid3_state_names[] = { |
410e27a4 GR |
54 | [TFRC_SSTATE_NO_SENT] = "NO_SENT", |
55 | [TFRC_SSTATE_NO_FBACK] = "NO_FBACK", | |
56 | [TFRC_SSTATE_FBACK] = "FBACK", | |
57 | [TFRC_SSTATE_TERM] = "TERM", | |
58 | }; | |
59 | ||
60 | return ccid3_state_names[state]; | |
61 | } | |
62 | #endif | |
63 | ||
64 | static void ccid3_hc_tx_set_state(struct sock *sk, | |
65 | enum ccid3_hc_tx_states state) | |
66 | { | |
996ccf49 GR |
67 | struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk); |
68 | enum ccid3_hc_tx_states oldstate = hc->tx_state; | |
410e27a4 GR |
69 | |
70 | ccid3_pr_debug("%s(%p) %-8.8s -> %s\n", | |
71 | dccp_role(sk), sk, ccid3_tx_state_name(oldstate), | |
72 | ccid3_tx_state_name(state)); | |
73 | WARN_ON(state == oldstate); | |
996ccf49 | 74 | hc->tx_state = state; |
410e27a4 | 75 | } |
7c657876 | 76 | |
a21f9f96 | 77 | /* |
6c08b2cf GR |
78 | * Compute the initial sending rate X_init in the manner of RFC 3390: |
79 | * | |
410e27a4 | 80 | * X_init = min(4 * s, max(2 * s, 4380 bytes)) / RTT |
6c08b2cf | 81 | * |
410e27a4 GR |
82 | * Note that RFC 3390 uses MSS, RFC 4342 refers to RFC 3390, and rfc3448bis |
83 | * (rev-02) clarifies the use of RFC 3390 with regard to the above formula. | |
a21f9f96 GR |
84 | * For consistency with other parts of the code, X_init is scaled by 2^6. |
85 | */ | |
86 | static inline u64 rfc3390_initial_rate(struct sock *sk) | |
87 | { | |
996ccf49 GR |
88 | const struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk); |
89 | const __u32 w_init = clamp_t(__u32, 4380U, 2 * hc->tx_s, 4 * hc->tx_s); | |
a21f9f96 | 90 | |
996ccf49 | 91 | return scaled_div(w_init << 6, hc->tx_rtt); |
a21f9f96 GR |
92 | } |
93 | ||
410e27a4 GR |
94 | /* |
95 | * Recalculate t_ipi and delta (should be called whenever X changes) | |
17893bc1 | 96 | */ |
996ccf49 | 97 | static void ccid3_update_send_interval(struct ccid3_hc_tx_sock *hc) |
7c657876 | 98 | { |
410e27a4 | 99 | /* Calculate new t_ipi = s / X_inst (X_inst is in 64 * bytes/second) */ |
996ccf49 | 100 | hc->tx_t_ipi = scaled_div32(((u64)hc->tx_s) << 6, hc->tx_x); |
410e27a4 GR |
101 | |
102 | /* Calculate new delta by delta = min(t_ipi / 2, t_gran / 2) */ | |
996ccf49 | 103 | hc->tx_delta = min_t(u32, hc->tx_t_ipi / 2, TFRC_OPSYS_HALF_TIME_GRAN); |
410e27a4 | 104 | |
996ccf49 GR |
105 | ccid3_pr_debug("t_ipi=%u, delta=%u, s=%u, X=%u\n", hc->tx_t_ipi, |
106 | hc->tx_delta, hc->tx_s, (unsigned)(hc->tx_x >> 6)); | |
7c657876 | 107 | } |
aa97efd9 | 108 | |
996ccf49 | 109 | static u32 ccid3_hc_tx_idle_rtt(struct ccid3_hc_tx_sock *hc, ktime_t now) |
a5358fdc | 110 | { |
996ccf49 | 111 | u32 delta = ktime_us_delta(now, hc->tx_t_last_win_count); |
a5358fdc | 112 | |
996ccf49 | 113 | return delta / hc->tx_rtt; |
a5358fdc GR |
114 | } |
115 | ||
aa97efd9 GR |
116 | /** |
117 | * ccid3_hc_tx_update_x - Update allowed sending rate X | |
118 | * @stamp: most recent time if available - can be left NULL. | |
119 | * This function tracks draft rfc3448bis, check there for latest details. | |
5c3fbb6a | 120 | * |
1a21e49a GR |
121 | * Note: X and X_recv are both stored in units of 64 * bytes/second, to support |
122 | * fine-grained resolution of sending rates. This requires scaling by 2^6 | |
123 | * throughout the code. Only X_calc is unscaled (in bytes/second). | |
124 | * | |
1a21e49a | 125 | */ |
aa97efd9 | 126 | static void ccid3_hc_tx_update_x(struct sock *sk, ktime_t *stamp) |
7c657876 | 127 | { |
996ccf49 GR |
128 | struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk); |
129 | __u64 min_rate = 2 * hc->tx_x_recv; | |
130 | const __u64 old_x = hc->tx_x; | |
52515e77 | 131 | ktime_t now = stamp ? *stamp : ktime_get_real(); |
7c657876 | 132 | |
0c150efb GR |
133 | /* |
134 | * Handle IDLE periods: do not reduce below RFC3390 initial sending rate | |
a5358fdc GR |
135 | * when idling [RFC 4342, 5.1]. Definition of idling is from rfc3448bis: |
136 | * a sender is idle if it has not sent anything over a 2-RTT-period. | |
0c150efb GR |
137 | * For consistency with X and X_recv, min_rate is also scaled by 2^6. |
138 | */ | |
996ccf49 | 139 | if (ccid3_hc_tx_idle_rtt(hc, now) >= 2) { |
0c150efb | 140 | min_rate = rfc3390_initial_rate(sk); |
996ccf49 | 141 | min_rate = max(min_rate, 2 * hc->tx_x_recv); |
0c150efb GR |
142 | } |
143 | ||
996ccf49 | 144 | if (hc->tx_p > 0) { |
1a21e49a | 145 | |
996ccf49 GR |
146 | hc->tx_x = min(((__u64)hc->tx_x_calc) << 6, min_rate); |
147 | hc->tx_x = max(hc->tx_x, (((__u64)hc->tx_s) << 6) / TFRC_T_MBI); | |
a79ef76f | 148 | |
996ccf49 | 149 | } else if (ktime_us_delta(now, hc->tx_t_ld) - (s64)hc->tx_rtt >= 0) { |
ac198ea8 | 150 | |
996ccf49 GR |
151 | hc->tx_x = min(2 * hc->tx_x, min_rate); |
152 | hc->tx_x = max(hc->tx_x, | |
153 | scaled_div(((__u64)hc->tx_s) << 6, hc->tx_rtt)); | |
154 | hc->tx_t_ld = now; | |
ff586298 | 155 | } |
b6ee3d4a | 156 | |
996ccf49 | 157 | if (hc->tx_x != old_x) { |
1761f7d7 GR |
158 | ccid3_pr_debug("X_prev=%u, X_now=%u, X_calc=%u, " |
159 | "X_recv=%u\n", (unsigned)(old_x >> 6), | |
996ccf49 GR |
160 | (unsigned)(hc->tx_x >> 6), hc->tx_x_calc, |
161 | (unsigned)(hc->tx_x_recv >> 6)); | |
8699be7d | 162 | |
996ccf49 | 163 | ccid3_update_send_interval(hc); |
8699be7d | 164 | } |
7c657876 ACM |
165 | } |
166 | ||
78ad713d | 167 | /* |
410e27a4 GR |
168 | * Track the mean packet size `s' (cf. RFC 4342, 5.3 and RFC 3448, 4.1) |
169 | * @len: DCCP packet payload size in bytes | |
78ad713d | 170 | */ |
996ccf49 | 171 | static inline void ccid3_hc_tx_update_s(struct ccid3_hc_tx_sock *hc, int len) |
78ad713d | 172 | { |
996ccf49 | 173 | const u16 old_s = hc->tx_s; |
410e27a4 | 174 | |
996ccf49 | 175 | hc->tx_s = tfrc_ewma(hc->tx_s, len, 9); |
410e27a4 | 176 | |
996ccf49 GR |
177 | if (hc->tx_s != old_s) |
178 | ccid3_update_send_interval(hc); | |
78ad713d GR |
179 | } |
180 | ||
9f8681db | 181 | /* |
8109b02b | 182 | * Update Window Counter using the algorithm from [RFC 4342, 8.1]. |
825de27d | 183 | * As elsewhere, RTT > 0 is assumed by using dccp_sample_rtt(). |
9f8681db | 184 | */ |
996ccf49 | 185 | static inline void ccid3_hc_tx_update_win_count(struct ccid3_hc_tx_sock *hc, |
8132da4d | 186 | ktime_t now) |
9f8681db | 187 | { |
996ccf49 GR |
188 | u32 delta = ktime_us_delta(now, hc->tx_t_last_win_count), |
189 | quarter_rtts = (4 * delta) / hc->tx_rtt; | |
9f8681db GR |
190 | |
191 | if (quarter_rtts > 0) { | |
996ccf49 GR |
192 | hc->tx_t_last_win_count = now; |
193 | hc->tx_last_win_count += min(quarter_rtts, 5U); | |
194 | hc->tx_last_win_count &= 0xF; /* mod 16 */ | |
9f8681db GR |
195 | } |
196 | } | |
197 | ||
7c657876 ACM |
198 | static void ccid3_hc_tx_no_feedback_timer(unsigned long data) |
199 | { | |
200 | struct sock *sk = (struct sock *)data; | |
996ccf49 | 201 | struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk); |
2a1fda6f | 202 | unsigned long t_nfb = USEC_PER_SEC / 5; |
7c657876 ACM |
203 | |
204 | bh_lock_sock(sk); | |
205 | if (sock_owned_by_user(sk)) { | |
206 | /* Try again later. */ | |
207 | /* XXX: set some sensible MIB */ | |
48e03eee | 208 | goto restart_timer; |
7c657876 ACM |
209 | } |
210 | ||
b1383380 | 211 | ccid3_pr_debug("%s(%p, state=%s) - entry\n", dccp_role(sk), sk, |
996ccf49 | 212 | ccid3_tx_state_name(hc->tx_state)); |
a9672411 | 213 | |
996ccf49 | 214 | if (hc->tx_state == TFRC_SSTATE_FBACK) |
410e27a4 | 215 | ccid3_hc_tx_set_state(sk, TFRC_SSTATE_NO_FBACK); |
996ccf49 | 216 | else if (hc->tx_state != TFRC_SSTATE_NO_FBACK) |
d0995e6a GR |
217 | goto out; |
218 | ||
52515e77 GR |
219 | /* |
220 | * Determine new allowed sending rate X as per draft rfc3448bis-00, 4.4 | |
67b67e36 | 221 | * RTO is 0 if and only if no feedback has been received yet. |
52515e77 | 222 | */ |
67b67e36 | 223 | if (hc->tx_t_rto == 0 || hc->tx_p == 0) { |
52515e77 GR |
224 | |
225 | /* halve send rate directly */ | |
996ccf49 GR |
226 | hc->tx_x = max(hc->tx_x / 2, |
227 | (((__u64)hc->tx_s) << 6) / TFRC_T_MBI); | |
228 | ccid3_update_send_interval(hc); | |
52515e77 | 229 | } else { |
1f2333ae | 230 | /* |
52515e77 | 231 | * Modify the cached value of X_recv |
0c150efb | 232 | * |
52515e77 | 233 | * If (X_calc > 2 * X_recv) |
0c150efb GR |
234 | * X_recv = max(X_recv / 2, s / (2 * t_mbi)); |
235 | * Else | |
236 | * X_recv = X_calc / 4; | |
237 | * | |
238 | * Note that X_recv is scaled by 2^6 while X_calc is not | |
1f2333ae | 239 | */ |
996ccf49 | 240 | BUG_ON(hc->tx_p && !hc->tx_x_calc); |
0c150efb | 241 | |
996ccf49 GR |
242 | if (hc->tx_x_calc > (hc->tx_x_recv >> 5)) |
243 | hc->tx_x_recv = | |
244 | max(hc->tx_x_recv / 2, | |
245 | (((__u64)hc->tx_s) << 6) / (2*TFRC_T_MBI)); | |
52515e77 | 246 | else { |
996ccf49 GR |
247 | hc->tx_x_recv = hc->tx_x_calc; |
248 | hc->tx_x_recv <<= 4; | |
7c657876 | 249 | } |
aa97efd9 | 250 | ccid3_hc_tx_update_x(sk, NULL); |
7c657876 | 251 | } |
52515e77 | 252 | ccid3_pr_debug("Reduced X to %llu/64 bytes/sec\n", |
996ccf49 | 253 | (unsigned long long)hc->tx_x); |
52515e77 GR |
254 | |
255 | /* | |
256 | * Set new timeout for the nofeedback timer. | |
257 | * See comments in packet_recv() regarding the value of t_RTO. | |
258 | */ | |
67b67e36 | 259 | if (unlikely(hc->tx_t_rto == 0)) /* no feedback received yet */ |
52515e77 GR |
260 | t_nfb = TFRC_INITIAL_TIMEOUT; |
261 | else | |
996ccf49 | 262 | t_nfb = max(hc->tx_t_rto, 2 * hc->tx_t_ipi); |
7c657876 | 263 | |
48e03eee | 264 | restart_timer: |
996ccf49 | 265 | sk_reset_timer(sk, &hc->tx_no_feedback_timer, |
c9eaf173 | 266 | jiffies + usecs_to_jiffies(t_nfb)); |
7c657876 ACM |
267 | out: |
268 | bh_unlock_sock(sk); | |
269 | sock_put(sk); | |
270 | } | |
271 | ||
410e27a4 GR |
272 | /* |
273 | * returns | |
274 | * > 0: delay (in msecs) that should pass before actually sending | |
275 | * = 0: can send immediately | |
276 | * < 0: error condition; do not send packet | |
7da7f456 | 277 | */ |
6b57c93d | 278 | static int ccid3_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb) |
7c657876 ACM |
279 | { |
280 | struct dccp_sock *dp = dccp_sk(sk); | |
996ccf49 | 281 | struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk); |
8132da4d GR |
282 | ktime_t now = ktime_get_real(); |
283 | s64 delay; | |
7c657876 | 284 | |
7c657876 | 285 | /* |
da335baf GR |
286 | * This function is called only for Data and DataAck packets. Sending |
287 | * zero-sized Data(Ack)s is theoretically possible, but for congestion | |
288 | * control this case is pathological - ignore it. | |
7c657876 | 289 | */ |
6b57c93d | 290 | if (unlikely(skb->len == 0)) |
da335baf | 291 | return -EBADMSG; |
7c657876 | 292 | |
996ccf49 | 293 | switch (hc->tx_state) { |
410e27a4 | 294 | case TFRC_SSTATE_NO_SENT: |
996ccf49 GR |
295 | sk_reset_timer(sk, &hc->tx_no_feedback_timer, (jiffies + |
296 | usecs_to_jiffies(TFRC_INITIAL_TIMEOUT))); | |
297 | hc->tx_last_win_count = 0; | |
298 | hc->tx_t_last_win_count = now; | |
90feeb95 GR |
299 | |
300 | /* Set t_0 for initial packet */ | |
996ccf49 | 301 | hc->tx_t_nom = now; |
410e27a4 | 302 | |
996ccf49 | 303 | hc->tx_s = skb->len; |
30833ffe | 304 | |
30833ffe GR |
305 | /* |
306 | * Use initial RTT sample when available: recommended by erratum | |
307 | * to RFC 4342. This implements the initialisation procedure of | |
308 | * draft rfc3448bis, section 4.2. Remember, X is scaled by 2^6. | |
309 | */ | |
310 | if (dp->dccps_syn_rtt) { | |
311 | ccid3_pr_debug("SYN RTT = %uus\n", dp->dccps_syn_rtt); | |
996ccf49 GR |
312 | hc->tx_rtt = dp->dccps_syn_rtt; |
313 | hc->tx_x = rfc3390_initial_rate(sk); | |
314 | hc->tx_t_ld = now; | |
30833ffe | 315 | } else { |
3294f202 GR |
316 | /* |
317 | * Sender does not have RTT sample: | |
318 | * - set fallback RTT (RFC 4340, 3.4) since a RTT value | |
319 | * is needed in several parts (e.g. window counter); | |
320 | * - set sending rate X_pps = 1pps as per RFC 3448, 4.2. | |
321 | */ | |
996ccf49 GR |
322 | hc->tx_rtt = DCCP_FALLBACK_RTT; |
323 | hc->tx_x = hc->tx_s; | |
324 | hc->tx_x <<= 6; | |
30833ffe | 325 | } |
996ccf49 | 326 | ccid3_update_send_interval(hc); |
30833ffe | 327 | |
410e27a4 GR |
328 | ccid3_hc_tx_set_state(sk, TFRC_SSTATE_NO_FBACK); |
329 | break; | |
330 | case TFRC_SSTATE_NO_FBACK: | |
331 | case TFRC_SSTATE_FBACK: | |
996ccf49 | 332 | delay = ktime_us_delta(hc->tx_t_nom, now); |
8699be7d | 333 | ccid3_pr_debug("delay=%ld\n", (long)delay); |
91cf5a17 | 334 | /* |
8109b02b | 335 | * Scheduling of packet transmissions [RFC 3448, 4.6] |
91cf5a17 GR |
336 | * |
337 | * if (t_now > t_nom - delta) | |
338 | * // send the packet now | |
339 | * else | |
340 | * // send the packet in (t_nom - t_now) milliseconds. | |
341 | */ | |
996ccf49 | 342 | if (delay - (s64)hc->tx_delta >= 1000) |
410e27a4 | 343 | return (u32)delay / 1000L; |
9f8681db | 344 | |
996ccf49 | 345 | ccid3_hc_tx_update_win_count(hc, now); |
410e27a4 GR |
346 | break; |
347 | case TFRC_SSTATE_TERM: | |
348 | DCCP_BUG("%s(%p) - Illegal state TERM", dccp_role(sk), sk); | |
349 | return -EINVAL; | |
7c657876 ACM |
350 | } |
351 | ||
7da7f456 GR |
352 | /* prepare to send now (add options etc.) */ |
353 | dp->dccps_hc_tx_insert_options = 1; | |
996ccf49 | 354 | DCCP_SKB_CB(skb)->dccpd_ccval = hc->tx_last_win_count; |
e312d100 GR |
355 | |
356 | /* set the nominal send time for the next following packet */ | |
996ccf49 | 357 | hc->tx_t_nom = ktime_add_us(hc->tx_t_nom, hc->tx_t_ipi); |
410e27a4 | 358 | return 0; |
7c657876 ACM |
359 | } |
360 | ||
410e27a4 GR |
361 | static void ccid3_hc_tx_packet_sent(struct sock *sk, int more, |
362 | unsigned int len) | |
7c657876 | 363 | { |
996ccf49 | 364 | struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk); |
7c657876 | 365 | |
996ccf49 | 366 | ccid3_hc_tx_update_s(hc, len); |
7c657876 | 367 | |
996ccf49 | 368 | if (tfrc_tx_hist_add(&hc->tx_hist, dccp_sk(sk)->dccps_gss)) |
c5a1ae9a | 369 | DCCP_CRIT("packet history - out of memory!"); |
7c657876 ACM |
370 | } |
371 | ||
372 | static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) | |
373 | { | |
996ccf49 | 374 | struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk); |
67b67e36 | 375 | struct ccid3_options_received *opt_recv = &hc->tx_options_received; |
0740d49c | 376 | ktime_t now; |
2a1fda6f | 377 | unsigned long t_nfb; |
410e27a4 | 378 | u32 pinv, r_sample; |
1f2333ae | 379 | |
7c657876 ACM |
380 | /* we are only interested in ACKs */ |
381 | if (!(DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_ACK || | |
382 | DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_DATAACK)) | |
383 | return; | |
410e27a4 | 384 | /* ... and only in the established state */ |
996ccf49 GR |
385 | if (hc->tx_state != TFRC_SSTATE_FBACK && |
386 | hc->tx_state != TFRC_SSTATE_NO_FBACK) | |
410e27a4 GR |
387 | return; |
388 | ||
410e27a4 GR |
389 | now = ktime_get_real(); |
390 | ||
391 | /* Estimate RTT from history if ACK number is valid */ | |
996ccf49 | 392 | r_sample = tfrc_tx_hist_rtt(hc->tx_hist, |
410e27a4 GR |
393 | DCCP_SKB_CB(skb)->dccpd_ack_seq, now); |
394 | if (r_sample == 0) { | |
395 | DCCP_WARN("%s(%p): %s with bogus ACK-%llu\n", dccp_role(sk), sk, | |
396 | dccp_packet_name(DCCP_SKB_CB(skb)->dccpd_type), | |
397 | (unsigned long long)DCCP_SKB_CB(skb)->dccpd_ack_seq); | |
5bd370a6 | 398 | return; |
410e27a4 | 399 | } |
63b3a73b | 400 | |
410e27a4 | 401 | /* Update receive rate in units of 64 * bytes/second */ |
996ccf49 GR |
402 | hc->tx_x_recv = opt_recv->ccid3or_receive_rate; |
403 | hc->tx_x_recv <<= 6; | |
7c657876 | 404 | |
410e27a4 GR |
405 | /* Update loss event rate (which is scaled by 1e6) */ |
406 | pinv = opt_recv->ccid3or_loss_event_rate; | |
407 | if (pinv == ~0U || pinv == 0) /* see RFC 4342, 8.5 */ | |
996ccf49 | 408 | hc->tx_p = 0; |
410e27a4 | 409 | else /* can not exceed 100% */ |
996ccf49 | 410 | hc->tx_p = scaled_div(1, pinv); |
410e27a4 GR |
411 | /* |
412 | * Validate new RTT sample and update moving average | |
413 | */ | |
414 | r_sample = dccp_sample_rtt(sk, r_sample); | |
996ccf49 | 415 | hc->tx_rtt = tfrc_ewma(hc->tx_rtt, r_sample, 9); |
d8d1252f GR |
416 | /* |
417 | * Update allowed sending rate X as per draft rfc3448bis-00, 4.2/3 | |
418 | */ | |
996ccf49 | 419 | if (hc->tx_state == TFRC_SSTATE_NO_FBACK) { |
410e27a4 | 420 | ccid3_hc_tx_set_state(sk, TFRC_SSTATE_FBACK); |
5c3fbb6a | 421 | |
996ccf49 | 422 | if (hc->tx_t_rto == 0) { |
d8d1252f GR |
423 | /* |
424 | * Initial feedback packet: Larger Initial Windows (4.2) | |
425 | */ | |
996ccf49 GR |
426 | hc->tx_x = rfc3390_initial_rate(sk); |
427 | hc->tx_t_ld = now; | |
a79ef76f | 428 | |
996ccf49 | 429 | ccid3_update_send_interval(hc); |
7c657876 | 430 | |
d8d1252f | 431 | goto done_computing_x; |
996ccf49 | 432 | } else if (hc->tx_p == 0) { |
d8d1252f GR |
433 | /* |
434 | * First feedback after nofeedback timer expiry (4.3) | |
435 | */ | |
436 | goto done_computing_x; | |
437 | } | |
438 | } | |
7c657876 | 439 | |
d8d1252f | 440 | /* Update sending rate (step 4 of [RFC 3448, 4.3]) */ |
996ccf49 GR |
441 | if (hc->tx_p > 0) |
442 | hc->tx_x_calc = tfrc_calc_x(hc->tx_s, hc->tx_rtt, hc->tx_p); | |
d8d1252f | 443 | ccid3_hc_tx_update_x(sk, &now); |
7c657876 | 444 | |
d8d1252f GR |
445 | done_computing_x: |
446 | ccid3_pr_debug("%s(%p), RTT=%uus (sample=%uus), s=%u, " | |
5bd370a6 | 447 | "p=%u, X_calc=%u, X_recv=%u, X=%u\n", |
996ccf49 GR |
448 | dccp_role(sk), sk, hc->tx_rtt, r_sample, |
449 | hc->tx_s, hc->tx_p, hc->tx_x_calc, | |
450 | (unsigned)(hc->tx_x_recv >> 6), | |
451 | (unsigned)(hc->tx_x >> 6)); | |
7c657876 | 452 | |
5bd370a6 | 453 | /* unschedule no feedback timer */ |
996ccf49 | 454 | sk_stop_timer(sk, &hc->tx_no_feedback_timer); |
7c657876 | 455 | |
5bd370a6 GR |
456 | /* |
457 | * As we have calculated new ipi, delta, t_nom it is possible | |
458 | * that we now can send a packet, so wake up dccp_wait_for_ccid | |
459 | */ | |
460 | sk->sk_write_space(sk); | |
8c60f3fa | 461 | |
5bd370a6 GR |
462 | /* |
463 | * Update timeout interval for the nofeedback timer. | |
464 | * We use a configuration option to increase the lower bound. | |
465 | * This can help avoid triggering the nofeedback timer too | |
466 | * often ('spinning') on LANs with small RTTs. | |
467 | */ | |
996ccf49 | 468 | hc->tx_t_rto = max_t(u32, 4 * hc->tx_rtt, (CONFIG_IP_DCCP_CCID3_RTO * |
388d5e99 | 469 | (USEC_PER_SEC / 1000))); |
5bd370a6 GR |
470 | /* |
471 | * Schedule no feedback timer to expire in | |
472 | * max(t_RTO, 2 * s/X) = max(t_RTO, 2 * t_ipi) | |
473 | */ | |
996ccf49 | 474 | t_nfb = max(hc->tx_t_rto, 2 * hc->tx_t_ipi); |
7c657876 | 475 | |
5bd370a6 GR |
476 | ccid3_pr_debug("%s(%p), Scheduled no feedback timer to " |
477 | "expire in %lu jiffies (%luus)\n", | |
388d5e99 | 478 | dccp_role(sk), sk, usecs_to_jiffies(t_nfb), t_nfb); |
a9672411 | 479 | |
996ccf49 | 480 | sk_reset_timer(sk, &hc->tx_no_feedback_timer, |
5bd370a6 | 481 | jiffies + usecs_to_jiffies(t_nfb)); |
7c657876 ACM |
482 | } |
483 | ||
410e27a4 GR |
484 | static int ccid3_hc_tx_parse_options(struct sock *sk, unsigned char option, |
485 | unsigned char len, u16 idx, | |
486 | unsigned char *value) | |
7c657876 | 487 | { |
410e27a4 GR |
488 | int rc = 0; |
489 | const struct dccp_sock *dp = dccp_sk(sk); | |
996ccf49 | 490 | struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk); |
67b67e36 | 491 | struct ccid3_options_received *opt_recv = &hc->tx_options_received; |
76fd1e87 | 492 | __be32 opt_val; |
7c657876 | 493 | |
410e27a4 GR |
494 | if (opt_recv->ccid3or_seqno != dp->dccps_gsr) { |
495 | opt_recv->ccid3or_seqno = dp->dccps_gsr; | |
496 | opt_recv->ccid3or_loss_event_rate = ~0; | |
497 | opt_recv->ccid3or_loss_intervals_idx = 0; | |
498 | opt_recv->ccid3or_loss_intervals_len = 0; | |
499 | opt_recv->ccid3or_receive_rate = 0; | |
500 | } | |
ce177ae2 | 501 | |
410e27a4 GR |
502 | switch (option) { |
503 | case TFRC_OPT_LOSS_EVENT_RATE: | |
504 | if (unlikely(len != 4)) { | |
505 | DCCP_WARN("%s(%p), invalid len %d " | |
506 | "for TFRC_OPT_LOSS_EVENT_RATE\n", | |
507 | dccp_role(sk), sk, len); | |
508 | rc = -EINVAL; | |
47a61e7b | 509 | } else { |
410e27a4 GR |
510 | opt_val = get_unaligned((__be32 *)value); |
511 | opt_recv->ccid3or_loss_event_rate = ntohl(opt_val); | |
47a61e7b | 512 | ccid3_pr_debug("%s(%p), LOSS_EVENT_RATE=%u\n", |
410e27a4 GR |
513 | dccp_role(sk), sk, |
514 | opt_recv->ccid3or_loss_event_rate); | |
7c657876 | 515 | } |
410e27a4 GR |
516 | break; |
517 | case TFRC_OPT_LOSS_INTERVALS: | |
518 | opt_recv->ccid3or_loss_intervals_idx = idx; | |
519 | opt_recv->ccid3or_loss_intervals_len = len; | |
520 | ccid3_pr_debug("%s(%p), LOSS_INTERVALS=(%u, %u)\n", | |
521 | dccp_role(sk), sk, | |
522 | opt_recv->ccid3or_loss_intervals_idx, | |
523 | opt_recv->ccid3or_loss_intervals_len); | |
524 | break; | |
525 | case TFRC_OPT_RECEIVE_RATE: | |
526 | if (unlikely(len != 4)) { | |
527 | DCCP_WARN("%s(%p), invalid len %d " | |
528 | "for TFRC_OPT_RECEIVE_RATE\n", | |
529 | dccp_role(sk), sk, len); | |
530 | rc = -EINVAL; | |
531 | } else { | |
532 | opt_val = get_unaligned((__be32 *)value); | |
533 | opt_recv->ccid3or_receive_rate = ntohl(opt_val); | |
534 | ccid3_pr_debug("%s(%p), RECEIVE_RATE=%u\n", | |
535 | dccp_role(sk), sk, | |
536 | opt_recv->ccid3or_receive_rate); | |
537 | } | |
538 | break; | |
7c657876 | 539 | } |
410e27a4 GR |
540 | |
541 | return rc; | |
7c657876 ACM |
542 | } |
543 | ||
91f0ebf7 | 544 | static int ccid3_hc_tx_init(struct ccid *ccid, struct sock *sk) |
7c657876 | 545 | { |
996ccf49 | 546 | struct ccid3_hc_tx_sock *hc = ccid_priv(ccid); |
7c657876 | 547 | |
996ccf49 GR |
548 | hc->tx_state = TFRC_SSTATE_NO_SENT; |
549 | hc->tx_hist = NULL; | |
550 | setup_timer(&hc->tx_no_feedback_timer, | |
410e27a4 | 551 | ccid3_hc_tx_no_feedback_timer, (unsigned long)sk); |
7c657876 ACM |
552 | return 0; |
553 | } | |
554 | ||
555 | static void ccid3_hc_tx_exit(struct sock *sk) | |
556 | { | |
996ccf49 | 557 | struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk); |
7c657876 | 558 | |
410e27a4 | 559 | ccid3_hc_tx_set_state(sk, TFRC_SSTATE_TERM); |
996ccf49 | 560 | sk_stop_timer(sk, &hc->tx_no_feedback_timer); |
410e27a4 | 561 | |
996ccf49 | 562 | tfrc_tx_hist_purge(&hc->tx_hist); |
7c657876 ACM |
563 | } |
564 | ||
9bf17475 GR |
565 | static void ccid3_hc_tx_get_info(struct sock *sk, struct tcp_info *info) |
566 | { | |
996ccf49 | 567 | struct ccid3_hc_tx_sock *hc; |
410e27a4 GR |
568 | |
569 | /* Listen socks doesn't have a private CCID block */ | |
570 | if (sk->sk_state == DCCP_LISTEN) | |
571 | return; | |
572 | ||
996ccf49 GR |
573 | hc = ccid3_hc_tx_sk(sk); |
574 | info->tcpi_rto = hc->tx_t_rto; | |
575 | info->tcpi_rtt = hc->tx_rtt; | |
9bf17475 GR |
576 | } |
577 | ||
578 | static int ccid3_hc_tx_getsockopt(struct sock *sk, const int optname, int len, | |
579 | u32 __user *optval, int __user *optlen) | |
580 | { | |
996ccf49 | 581 | const struct ccid3_hc_tx_sock *hc; |
67b67e36 | 582 | struct tfrc_tx_info tfrc; |
9bf17475 GR |
583 | const void *val; |
584 | ||
410e27a4 GR |
585 | /* Listen socks doesn't have a private CCID block */ |
586 | if (sk->sk_state == DCCP_LISTEN) | |
587 | return -EINVAL; | |
588 | ||
996ccf49 | 589 | hc = ccid3_hc_tx_sk(sk); |
9bf17475 GR |
590 | switch (optname) { |
591 | case DCCP_SOCKOPT_CCID_TX_INFO: | |
67b67e36 | 592 | if (len < sizeof(tfrc)) |
9bf17475 | 593 | return -EINVAL; |
67b67e36 GR |
594 | tfrc.tfrctx_x = hc->tx_x; |
595 | tfrc.tfrctx_x_recv = hc->tx_x_recv; | |
596 | tfrc.tfrctx_x_calc = hc->tx_x_calc; | |
597 | tfrc.tfrctx_rtt = hc->tx_rtt; | |
598 | tfrc.tfrctx_p = hc->tx_p; | |
599 | tfrc.tfrctx_rto = hc->tx_t_rto; | |
600 | tfrc.tfrctx_ipi = hc->tx_t_ipi; | |
601 | len = sizeof(tfrc); | |
602 | val = &tfrc; | |
9bf17475 GR |
603 | break; |
604 | default: | |
605 | return -ENOPROTOOPT; | |
606 | } | |
607 | ||
608 | if (put_user(len, optlen) || copy_to_user(optval, val, len)) | |
609 | return -EFAULT; | |
610 | ||
611 | return 0; | |
612 | } | |
613 | ||
7c657876 | 614 | /* |
9bf17475 | 615 | * Receiver Half-Connection Routines |
7c657876 | 616 | */ |
410e27a4 GR |
617 | |
618 | /* CCID3 feedback types */ | |
619 | enum ccid3_fback_type { | |
620 | CCID3_FBACK_NONE = 0, | |
621 | CCID3_FBACK_INITIAL, | |
622 | CCID3_FBACK_PERIODIC, | |
623 | CCID3_FBACK_PARAM_CHANGE | |
624 | }; | |
625 | ||
626 | #ifdef CONFIG_IP_DCCP_CCID3_DEBUG | |
627 | static const char *ccid3_rx_state_name(enum ccid3_hc_rx_states state) | |
628 | { | |
36cbd3dc | 629 | static const char *const ccid3_rx_state_names[] = { |
410e27a4 GR |
630 | [TFRC_RSTATE_NO_DATA] = "NO_DATA", |
631 | [TFRC_RSTATE_DATA] = "DATA", | |
632 | [TFRC_RSTATE_TERM] = "TERM", | |
633 | }; | |
634 | ||
635 | return ccid3_rx_state_names[state]; | |
636 | } | |
637 | #endif | |
638 | ||
639 | static void ccid3_hc_rx_set_state(struct sock *sk, | |
640 | enum ccid3_hc_rx_states state) | |
641 | { | |
996ccf49 GR |
642 | struct ccid3_hc_rx_sock *hc = ccid3_hc_rx_sk(sk); |
643 | enum ccid3_hc_rx_states oldstate = hc->rx_state; | |
410e27a4 GR |
644 | |
645 | ccid3_pr_debug("%s(%p) %-8.8s -> %s\n", | |
646 | dccp_role(sk), sk, ccid3_rx_state_name(oldstate), | |
647 | ccid3_rx_state_name(state)); | |
648 | WARN_ON(state == oldstate); | |
996ccf49 | 649 | hc->rx_state = state; |
410e27a4 GR |
650 | } |
651 | ||
b84a2189 ACM |
652 | static void ccid3_hc_rx_send_feedback(struct sock *sk, |
653 | const struct sk_buff *skb, | |
654 | enum ccid3_fback_type fbtype) | |
7c657876 | 655 | { |
996ccf49 | 656 | struct ccid3_hc_rx_sock *hc = ccid3_hc_rx_sk(sk); |
410e27a4 GR |
657 | struct dccp_sock *dp = dccp_sk(sk); |
658 | ktime_t now; | |
659 | s64 delta = 0; | |
660 | ||
996ccf49 | 661 | if (unlikely(hc->rx_state == TFRC_RSTATE_TERM)) |
410e27a4 GR |
662 | return; |
663 | ||
664 | now = ktime_get_real(); | |
7c657876 | 665 | |
b84a2189 ACM |
666 | switch (fbtype) { |
667 | case CCID3_FBACK_INITIAL: | |
996ccf49 GR |
668 | hc->rx_x_recv = 0; |
669 | hc->rx_pinv = ~0U; /* see RFC 4342, 8.5 */ | |
7c657876 | 670 | break; |
b84a2189 ACM |
671 | case CCID3_FBACK_PARAM_CHANGE: |
672 | /* | |
673 | * When parameters change (new loss or p > p_prev), we do not | |
674 | * have a reliable estimate for R_m of [RFC 3448, 6.2] and so | |
410e27a4 GR |
675 | * need to reuse the previous value of X_recv. However, when |
676 | * X_recv was 0 (due to early loss), this would kill X down to | |
677 | * s/t_mbi (i.e. one packet in 64 seconds). | |
678 | * To avoid such drastic reduction, we approximate X_recv as | |
679 | * the number of bytes since last feedback. | |
680 | * This is a safe fallback, since X is bounded above by X_calc. | |
b84a2189 | 681 | */ |
996ccf49 | 682 | if (hc->rx_x_recv > 0) |
410e27a4 GR |
683 | break; |
684 | /* fall through */ | |
b84a2189 | 685 | case CCID3_FBACK_PERIODIC: |
996ccf49 | 686 | delta = ktime_us_delta(now, hc->rx_tstamp_last_feedback); |
410e27a4 GR |
687 | if (delta <= 0) |
688 | DCCP_BUG("delta (%ld) <= 0", (long)delta); | |
689 | else | |
996ccf49 | 690 | hc->rx_x_recv = scaled_div32(hc->rx_bytes_recv, delta); |
7c657876 | 691 | break; |
b84a2189 | 692 | default: |
7c657876 ACM |
693 | return; |
694 | } | |
695 | ||
410e27a4 | 696 | ccid3_pr_debug("Interval %ldusec, X_recv=%u, 1/p=%u\n", (long)delta, |
996ccf49 | 697 | hc->rx_x_recv, hc->rx_pinv); |
7c657876 | 698 | |
996ccf49 GR |
699 | hc->rx_tstamp_last_feedback = now; |
700 | hc->rx_last_counter = dccp_hdr(skb)->dccph_ccval; | |
701 | hc->rx_bytes_recv = 0; | |
68c89ee5 | 702 | |
410e27a4 GR |
703 | dp->dccps_hc_rx_insert_options = 1; |
704 | dccp_send_ack(sk); | |
7c657876 ACM |
705 | } |
706 | ||
2d0817d1 | 707 | static int ccid3_hc_rx_insert_options(struct sock *sk, struct sk_buff *skb) |
7c657876 | 708 | { |
996ccf49 | 709 | const struct ccid3_hc_rx_sock *hc; |
60fe62e7 | 710 | __be32 x_recv, pinv; |
7c657876 | 711 | |
59d203f9 | 712 | if (!(sk->sk_state == DCCP_OPEN || sk->sk_state == DCCP_PARTOPEN)) |
2d0817d1 | 713 | return 0; |
7c657876 | 714 | |
996ccf49 | 715 | hc = ccid3_hc_rx_sk(sk); |
410e27a4 | 716 | |
4fded33b | 717 | if (dccp_packet_without_ack(skb)) |
2d0817d1 ACM |
718 | return 0; |
719 | ||
996ccf49 GR |
720 | x_recv = htonl(hc->rx_x_recv); |
721 | pinv = htonl(hc->rx_pinv); | |
2d0817d1 | 722 | |
a7d13fbf | 723 | if (dccp_insert_option(skb, TFRC_OPT_LOSS_EVENT_RATE, |
8109b02b | 724 | &pinv, sizeof(pinv)) || |
a7d13fbf | 725 | dccp_insert_option(skb, TFRC_OPT_RECEIVE_RATE, |
8109b02b | 726 | &x_recv, sizeof(x_recv))) |
2d0817d1 ACM |
727 | return -1; |
728 | ||
729 | return 0; | |
7c657876 ACM |
730 | } |
731 | ||
aa1b1ff0 GR |
732 | /** |
733 | * ccid3_first_li - Implements [RFC 5348, 6.3.1] | |
954c2db8 GR |
734 | * |
735 | * Determine the length of the first loss interval via inverse lookup. | |
736 | * Assume that X_recv can be computed by the throughput equation | |
737 | * s | |
738 | * X_recv = -------- | |
739 | * R * fval | |
740 | * Find some p such that f(p) = fval; return 1/p (scaled). | |
741 | */ | |
742 | static u32 ccid3_first_li(struct sock *sk) | |
743 | { | |
996ccf49 | 744 | struct ccid3_hc_rx_sock *hc = ccid3_hc_rx_sk(sk); |
410e27a4 | 745 | u32 x_recv, p, delta; |
954c2db8 GR |
746 | u64 fval; |
747 | ||
996ccf49 | 748 | if (hc->rx_rtt == 0) { |
410e27a4 | 749 | DCCP_WARN("No RTT estimate available, using fallback RTT\n"); |
996ccf49 | 750 | hc->rx_rtt = DCCP_FALLBACK_RTT; |
410e27a4 | 751 | } |
d20ed95f | 752 | |
996ccf49 GR |
753 | delta = ktime_to_us(net_timedelta(hc->rx_tstamp_last_feedback)); |
754 | x_recv = scaled_div32(hc->rx_bytes_recv, delta); | |
410e27a4 GR |
755 | if (x_recv == 0) { /* would also trigger divide-by-zero */ |
756 | DCCP_WARN("X_recv==0\n"); | |
67b67e36 | 757 | if (hc->rx_x_recv == 0) { |
410e27a4 GR |
758 | DCCP_BUG("stored value of X_recv is zero"); |
759 | return ~0U; | |
760 | } | |
67b67e36 | 761 | x_recv = hc->rx_x_recv; |
410e27a4 | 762 | } |
954c2db8 | 763 | |
996ccf49 | 764 | fval = scaled_div(hc->rx_s, hc->rx_rtt); |
410e27a4 | 765 | fval = scaled_div32(fval, x_recv); |
954c2db8 GR |
766 | p = tfrc_calc_x_reverse_lookup(fval); |
767 | ||
768 | ccid3_pr_debug("%s(%p), receive rate=%u bytes/s, implied " | |
769 | "loss rate=%u\n", dccp_role(sk), sk, x_recv, p); | |
770 | ||
410e27a4 | 771 | return p == 0 ? ~0U : scaled_div(1, p); |
954c2db8 GR |
772 | } |
773 | ||
b84a2189 | 774 | static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb) |
7c657876 | 775 | { |
996ccf49 | 776 | struct ccid3_hc_rx_sock *hc = ccid3_hc_rx_sk(sk); |
410e27a4 | 777 | enum ccid3_fback_type do_feedback = CCID3_FBACK_NONE; |
5b5d0e70 | 778 | const u64 ndp = dccp_sk(sk)->dccps_options_received.dccpor_ndp; |
b84a2189 ACM |
779 | const bool is_data_packet = dccp_data_packet(skb); |
780 | ||
996ccf49 | 781 | if (unlikely(hc->rx_state == TFRC_RSTATE_NO_DATA)) { |
410e27a4 GR |
782 | if (is_data_packet) { |
783 | const u32 payload = skb->len - dccp_hdr(skb)->dccph_doff * 4; | |
784 | do_feedback = CCID3_FBACK_INITIAL; | |
785 | ccid3_hc_rx_set_state(sk, TFRC_RSTATE_DATA); | |
996ccf49 | 786 | hc->rx_s = payload; |
410e27a4 | 787 | /* |
388d5e99 | 788 | * Not necessary to update rx_bytes_recv here, |
410e27a4 GR |
789 | * since X_recv = 0 for the first feedback packet (cf. |
790 | * RFC 3448, 6.3) -- gerrit | |
791 | */ | |
792 | } | |
793 | goto update_records; | |
794 | } | |
795 | ||
996ccf49 | 796 | if (tfrc_rx_hist_duplicate(&hc->rx_hist, skb)) |
410e27a4 GR |
797 | return; /* done receiving */ |
798 | ||
799 | if (is_data_packet) { | |
800 | const u32 payload = skb->len - dccp_hdr(skb)->dccph_doff * 4; | |
801 | /* | |
802 | * Update moving-average of s and the sum of received payload bytes | |
803 | */ | |
996ccf49 GR |
804 | hc->rx_s = tfrc_ewma(hc->rx_s, payload, 9); |
805 | hc->rx_bytes_recv += payload; | |
410e27a4 GR |
806 | } |
807 | ||
d20ed95f GR |
808 | /* |
809 | * Perform loss detection and handle pending losses | |
810 | */ | |
996ccf49 | 811 | if (tfrc_rx_handle_loss(&hc->rx_hist, &hc->rx_li_hist, |
410e27a4 GR |
812 | skb, ndp, ccid3_first_li, sk)) { |
813 | do_feedback = CCID3_FBACK_PARAM_CHANGE; | |
814 | goto done_receiving; | |
815 | } | |
816 | ||
996ccf49 | 817 | if (tfrc_rx_hist_loss_pending(&hc->rx_hist)) |
410e27a4 GR |
818 | return; /* done receiving */ |
819 | ||
88e97a93 | 820 | /* |
410e27a4 | 821 | * Handle data packets: RTT sampling and monitoring p |
88e97a93 | 822 | */ |
410e27a4 GR |
823 | if (unlikely(!is_data_packet)) |
824 | goto update_records; | |
825 | ||
996ccf49 GR |
826 | if (!tfrc_lh_is_initialised(&hc->rx_li_hist)) { |
827 | const u32 sample = tfrc_rx_hist_sample_rtt(&hc->rx_hist, skb); | |
410e27a4 GR |
828 | /* |
829 | * Empty loss history: no loss so far, hence p stays 0. | |
830 | * Sample RTT values, since an RTT estimate is required for the | |
831 | * computation of p when the first loss occurs; RFC 3448, 6.3.1. | |
832 | */ | |
833 | if (sample != 0) | |
996ccf49 | 834 | hc->rx_rtt = tfrc_ewma(hc->rx_rtt, sample, 9); |
410e27a4 | 835 | |
996ccf49 | 836 | } else if (tfrc_lh_update_i_mean(&hc->rx_li_hist, skb)) { |
410e27a4 GR |
837 | /* |
838 | * Step (3) of [RFC 3448, 6.1]: Recompute I_mean and, if I_mean | |
839 | * has decreased (resp. p has increased), send feedback now. | |
840 | */ | |
841 | do_feedback = CCID3_FBACK_PARAM_CHANGE; | |
842 | } | |
843 | ||
b84a2189 ACM |
844 | /* |
845 | * Check if the periodic once-per-RTT feedback is due; RFC 4342, 10.3 | |
846 | */ | |
996ccf49 | 847 | if (SUB16(dccp_hdr(skb)->dccph_ccval, hc->rx_last_counter) > 3) |
410e27a4 GR |
848 | do_feedback = CCID3_FBACK_PERIODIC; |
849 | ||
850 | update_records: | |
996ccf49 | 851 | tfrc_rx_hist_add_packet(&hc->rx_hist, skb, ndp); |
410e27a4 GR |
852 | |
853 | done_receiving: | |
854 | if (do_feedback) | |
855 | ccid3_hc_rx_send_feedback(sk, skb, do_feedback); | |
7c657876 ACM |
856 | } |
857 | ||
91f0ebf7 | 858 | static int ccid3_hc_rx_init(struct ccid *ccid, struct sock *sk) |
7c657876 | 859 | { |
996ccf49 | 860 | struct ccid3_hc_rx_sock *hc = ccid_priv(ccid); |
7c657876 | 861 | |
996ccf49 GR |
862 | hc->rx_state = TFRC_RSTATE_NO_DATA; |
863 | tfrc_lh_init(&hc->rx_li_hist); | |
864 | return tfrc_rx_hist_alloc(&hc->rx_hist); | |
7c657876 ACM |
865 | } |
866 | ||
867 | static void ccid3_hc_rx_exit(struct sock *sk) | |
868 | { | |
996ccf49 | 869 | struct ccid3_hc_rx_sock *hc = ccid3_hc_rx_sk(sk); |
7c657876 | 870 | |
410e27a4 GR |
871 | ccid3_hc_rx_set_state(sk, TFRC_RSTATE_TERM); |
872 | ||
996ccf49 GR |
873 | tfrc_rx_hist_purge(&hc->rx_hist); |
874 | tfrc_lh_cleanup(&hc->rx_li_hist); | |
7c657876 ACM |
875 | } |
876 | ||
2babe1f6 ACM |
877 | static void ccid3_hc_rx_get_info(struct sock *sk, struct tcp_info *info) |
878 | { | |
996ccf49 | 879 | const struct ccid3_hc_rx_sock *hc; |
410e27a4 GR |
880 | |
881 | /* Listen socks doesn't have a private CCID block */ | |
882 | if (sk->sk_state == DCCP_LISTEN) | |
883 | return; | |
884 | ||
996ccf49 GR |
885 | hc = ccid3_hc_rx_sk(sk); |
886 | info->tcpi_ca_state = hc->rx_state; | |
8109b02b | 887 | info->tcpi_options |= TCPI_OPT_TIMESTAMPS; |
996ccf49 | 888 | info->tcpi_rcv_rtt = hc->rx_rtt; |
2babe1f6 ACM |
889 | } |
890 | ||
88f964db ACM |
891 | static int ccid3_hc_rx_getsockopt(struct sock *sk, const int optname, int len, |
892 | u32 __user *optval, int __user *optlen) | |
893 | { | |
996ccf49 | 894 | const struct ccid3_hc_rx_sock *hc; |
8e138e79 | 895 | struct tfrc_rx_info rx_info; |
88f964db | 896 | const void *val; |
c9eaf173 | 897 | |
410e27a4 GR |
898 | /* Listen socks doesn't have a private CCID block */ |
899 | if (sk->sk_state == DCCP_LISTEN) | |
900 | return -EINVAL; | |
901 | ||
996ccf49 | 902 | hc = ccid3_hc_rx_sk(sk); |
88f964db ACM |
903 | switch (optname) { |
904 | case DCCP_SOCKOPT_CCID_RX_INFO: | |
8e138e79 | 905 | if (len < sizeof(rx_info)) |
88f964db | 906 | return -EINVAL; |
996ccf49 GR |
907 | rx_info.tfrcrx_x_recv = hc->rx_x_recv; |
908 | rx_info.tfrcrx_rtt = hc->rx_rtt; | |
909 | rx_info.tfrcrx_p = hc->rx_pinv == 0 ? ~0U : | |
910 | scaled_div(1, hc->rx_pinv); | |
8e138e79 GR |
911 | len = sizeof(rx_info); |
912 | val = &rx_info; | |
88f964db ACM |
913 | break; |
914 | default: | |
915 | return -ENOPROTOOPT; | |
916 | } | |
917 | ||
918 | if (put_user(len, optlen) || copy_to_user(optval, val, len)) | |
919 | return -EFAULT; | |
920 | ||
921 | return 0; | |
922 | } | |
923 | ||
ddebc973 | 924 | struct ccid_operations ccid3_ops = { |
3dd9a7c3 | 925 | .ccid_id = DCCPC_CCID3, |
84a97b0a | 926 | .ccid_name = "TCP-Friendly Rate Control", |
91f0ebf7 | 927 | .ccid_hc_tx_obj_size = sizeof(struct ccid3_hc_tx_sock), |
7c657876 ACM |
928 | .ccid_hc_tx_init = ccid3_hc_tx_init, |
929 | .ccid_hc_tx_exit = ccid3_hc_tx_exit, | |
930 | .ccid_hc_tx_send_packet = ccid3_hc_tx_send_packet, | |
931 | .ccid_hc_tx_packet_sent = ccid3_hc_tx_packet_sent, | |
932 | .ccid_hc_tx_packet_recv = ccid3_hc_tx_packet_recv, | |
7c657876 | 933 | .ccid_hc_tx_parse_options = ccid3_hc_tx_parse_options, |
91f0ebf7 | 934 | .ccid_hc_rx_obj_size = sizeof(struct ccid3_hc_rx_sock), |
7c657876 ACM |
935 | .ccid_hc_rx_init = ccid3_hc_rx_init, |
936 | .ccid_hc_rx_exit = ccid3_hc_rx_exit, | |
937 | .ccid_hc_rx_insert_options = ccid3_hc_rx_insert_options, | |
938 | .ccid_hc_rx_packet_recv = ccid3_hc_rx_packet_recv, | |
2babe1f6 ACM |
939 | .ccid_hc_rx_get_info = ccid3_hc_rx_get_info, |
940 | .ccid_hc_tx_get_info = ccid3_hc_tx_get_info, | |
88f964db ACM |
941 | .ccid_hc_rx_getsockopt = ccid3_hc_rx_getsockopt, |
942 | .ccid_hc_tx_getsockopt = ccid3_hc_tx_getsockopt, | |
7c657876 | 943 | }; |
8109b02b | 944 | |
56724aa4 | 945 | #ifdef CONFIG_IP_DCCP_CCID3_DEBUG |
43264991 | 946 | module_param(ccid3_debug, bool, 0644); |
ddebc973 | 947 | MODULE_PARM_DESC(ccid3_debug, "Enable CCID-3 debug messages"); |
56724aa4 | 948 | #endif |