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 | { | |
67 | struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); | |
388d5e99 | 68 | enum ccid3_hc_tx_states oldstate = hctx->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); | |
388d5e99 | 74 | hctx->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 | { | |
410e27a4 | 88 | const struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); |
388d5e99 | 89 | const __u32 w_init = clamp_t(__u32, 4380U, 2 * hctx->tx_s, 4 * hctx->tx_s); |
a21f9f96 | 90 | |
388d5e99 | 91 | return scaled_div(w_init << 6, hctx->tx_rtt); |
a21f9f96 GR |
92 | } |
93 | ||
410e27a4 GR |
94 | /* |
95 | * Recalculate t_ipi and delta (should be called whenever X changes) | |
17893bc1 | 96 | */ |
c4e18dad | 97 | static void ccid3_update_send_interval(struct ccid3_hc_tx_sock *hctx) |
7c657876 | 98 | { |
410e27a4 | 99 | /* Calculate new t_ipi = s / X_inst (X_inst is in 64 * bytes/second) */ |
388d5e99 | 100 | hctx->tx_t_ipi = scaled_div32(((u64)hctx->tx_s) << 6, hctx->tx_x); |
410e27a4 GR |
101 | |
102 | /* Calculate new delta by delta = min(t_ipi / 2, t_gran / 2) */ | |
388d5e99 | 103 | hctx->tx_delta = min_t(u32, hctx->tx_t_ipi / 2, TFRC_OPSYS_HALF_TIME_GRAN); |
410e27a4 | 104 | |
388d5e99 GR |
105 | ccid3_pr_debug("t_ipi=%u, delta=%u, s=%u, X=%u\n", hctx->tx_t_ipi, |
106 | hctx->tx_delta, hctx->tx_s, (unsigned)(hctx->tx_x >> 6)); | |
7c657876 | 107 | } |
aa97efd9 | 108 | |
a5358fdc GR |
109 | static u32 ccid3_hc_tx_idle_rtt(struct ccid3_hc_tx_sock *hctx, ktime_t now) |
110 | { | |
388d5e99 | 111 | u32 delta = ktime_us_delta(now, hctx->tx_t_last_win_count); |
a5358fdc | 112 | |
388d5e99 | 113 | return delta / hctx->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 | { |
59725dc2 | 128 | struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); |
388d5e99 GR |
129 | __u64 min_rate = 2 * hctx->tx_x_recv; |
130 | const __u64 old_x = hctx->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 | */ | |
a5358fdc | 139 | if (ccid3_hc_tx_idle_rtt(hctx, now) >= 2) { |
0c150efb | 140 | min_rate = rfc3390_initial_rate(sk); |
388d5e99 | 141 | min_rate = max(min_rate, 2 * hctx->tx_x_recv); |
0c150efb GR |
142 | } |
143 | ||
388d5e99 | 144 | if (hctx->tx_p > 0) { |
1a21e49a | 145 | |
388d5e99 GR |
146 | hctx->tx_x = min(((__u64)hctx->tx_x_calc) << 6, min_rate); |
147 | hctx->tx_x = max(hctx->tx_x, (((__u64)hctx->tx_s) << 6) / TFRC_T_MBI); | |
a79ef76f | 148 | |
388d5e99 | 149 | } else if (ktime_us_delta(now, hctx->tx_t_ld) - (s64)hctx->tx_rtt >= 0) { |
ac198ea8 | 150 | |
388d5e99 GR |
151 | hctx->tx_x = min(2 * hctx->tx_x, min_rate); |
152 | hctx->tx_x = max(hctx->tx_x, scaled_div(((__u64)hctx->tx_s) << 6, | |
153 | hctx->tx_rtt)); | |
154 | hctx->tx_t_ld = now; | |
ff586298 | 155 | } |
b6ee3d4a | 156 | |
388d5e99 | 157 | if (hctx->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), | |
388d5e99 GR |
160 | (unsigned)(hctx->tx_x >> 6), hctx->tx_x_calc, |
161 | (unsigned)(hctx->tx_x_recv >> 6)); | |
8699be7d | 162 | |
1266adee | 163 | ccid3_update_send_interval(hctx); |
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 | */ |
410e27a4 | 171 | static inline void ccid3_hc_tx_update_s(struct ccid3_hc_tx_sock *hctx, int len) |
78ad713d | 172 | { |
388d5e99 | 173 | const u16 old_s = hctx->tx_s; |
410e27a4 | 174 | |
388d5e99 | 175 | hctx->tx_s = tfrc_ewma(hctx->tx_s, len, 9); |
410e27a4 | 176 | |
388d5e99 | 177 | if (hctx->tx_s != old_s) |
410e27a4 | 178 | ccid3_update_send_interval(hctx); |
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 GR |
184 | */ |
185 | static inline void ccid3_hc_tx_update_win_count(struct ccid3_hc_tx_sock *hctx, | |
8132da4d | 186 | ktime_t now) |
9f8681db | 187 | { |
388d5e99 GR |
188 | u32 delta = ktime_us_delta(now, hctx->tx_t_last_win_count), |
189 | quarter_rtts = (4 * delta) / hctx->tx_rtt; | |
9f8681db GR |
190 | |
191 | if (quarter_rtts > 0) { | |
388d5e99 GR |
192 | hctx->tx_t_last_win_count = now; |
193 | hctx->tx_last_win_count += min(quarter_rtts, 5U); | |
194 | hctx->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; | |
59725dc2 | 201 | struct ccid3_hc_tx_sock *hctx = 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 | ||
410e27a4 | 211 | ccid3_pr_debug("%s(%p, state=%s) - entry \n", dccp_role(sk), sk, |
388d5e99 | 212 | ccid3_tx_state_name(hctx->tx_state)); |
a9672411 | 213 | |
388d5e99 | 214 | if (hctx->tx_state == TFRC_SSTATE_FBACK) |
410e27a4 | 215 | ccid3_hc_tx_set_state(sk, TFRC_SSTATE_NO_FBACK); |
388d5e99 | 216 | else if (hctx->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 | |
221 | */ | |
388d5e99 GR |
222 | if (hctx->tx_t_rto == 0 || /* no feedback received yet */ |
223 | hctx->tx_p == 0) { | |
52515e77 GR |
224 | |
225 | /* halve send rate directly */ | |
388d5e99 GR |
226 | hctx->tx_x = max(hctx->tx_x / 2, |
227 | (((__u64)hctx->tx_s) << 6) / TFRC_T_MBI); | |
1266adee | 228 | ccid3_update_send_interval(hctx); |
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 | */ |
388d5e99 | 240 | BUG_ON(hctx->tx_p && !hctx->tx_x_calc); |
0c150efb | 241 | |
388d5e99 GR |
242 | if (hctx->tx_x_calc > (hctx->tx_x_recv >> 5)) |
243 | hctx->tx_x_recv = | |
244 | max(hctx->tx_x_recv / 2, | |
245 | (((__u64)hctx->tx_s) << 6) / | |
410e27a4 | 246 | (2 * TFRC_T_MBI)); |
52515e77 | 247 | else { |
388d5e99 GR |
248 | hctx->tx_x_recv = hctx->tx_x_calc; |
249 | hctx->tx_x_recv <<= 4; | |
7c657876 | 250 | } |
aa97efd9 | 251 | ccid3_hc_tx_update_x(sk, NULL); |
7c657876 | 252 | } |
52515e77 | 253 | ccid3_pr_debug("Reduced X to %llu/64 bytes/sec\n", |
388d5e99 | 254 | (unsigned long long)hctx->tx_x); |
52515e77 GR |
255 | |
256 | /* | |
257 | * Set new timeout for the nofeedback timer. | |
258 | * See comments in packet_recv() regarding the value of t_RTO. | |
259 | */ | |
388d5e99 | 260 | if (unlikely(hctx->tx_t_rto == 0)) /* no feedback yet */ |
52515e77 GR |
261 | t_nfb = TFRC_INITIAL_TIMEOUT; |
262 | else | |
388d5e99 | 263 | t_nfb = max(hctx->tx_t_rto, 2 * hctx->tx_t_ipi); |
7c657876 | 264 | |
48e03eee | 265 | restart_timer: |
388d5e99 | 266 | sk_reset_timer(sk, &hctx->tx_no_feedback_timer, |
c9eaf173 | 267 | jiffies + usecs_to_jiffies(t_nfb)); |
7c657876 ACM |
268 | out: |
269 | bh_unlock_sock(sk); | |
270 | sock_put(sk); | |
271 | } | |
272 | ||
410e27a4 GR |
273 | /* |
274 | * returns | |
275 | * > 0: delay (in msecs) that should pass before actually sending | |
276 | * = 0: can send immediately | |
277 | * < 0: error condition; do not send packet | |
7da7f456 | 278 | */ |
6b57c93d | 279 | static int ccid3_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb) |
7c657876 ACM |
280 | { |
281 | struct dccp_sock *dp = dccp_sk(sk); | |
59725dc2 | 282 | struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); |
8132da4d GR |
283 | ktime_t now = ktime_get_real(); |
284 | s64 delay; | |
7c657876 | 285 | |
7c657876 | 286 | /* |
da335baf GR |
287 | * This function is called only for Data and DataAck packets. Sending |
288 | * zero-sized Data(Ack)s is theoretically possible, but for congestion | |
289 | * control this case is pathological - ignore it. | |
7c657876 | 290 | */ |
6b57c93d | 291 | if (unlikely(skb->len == 0)) |
da335baf | 292 | return -EBADMSG; |
7c657876 | 293 | |
388d5e99 | 294 | switch (hctx->tx_state) { |
410e27a4 | 295 | case TFRC_SSTATE_NO_SENT: |
388d5e99 | 296 | sk_reset_timer(sk, &hctx->tx_no_feedback_timer, (jiffies + |
c9eaf173 | 297 | usecs_to_jiffies(TFRC_INITIAL_TIMEOUT))); |
388d5e99 GR |
298 | hctx->tx_last_win_count = 0; |
299 | hctx->tx_t_last_win_count = now; | |
90feeb95 GR |
300 | |
301 | /* Set t_0 for initial packet */ | |
388d5e99 | 302 | hctx->tx_t_nom = now; |
410e27a4 | 303 | |
388d5e99 | 304 | hctx->tx_s = skb->len; |
30833ffe | 305 | |
30833ffe GR |
306 | /* |
307 | * Use initial RTT sample when available: recommended by erratum | |
308 | * to RFC 4342. This implements the initialisation procedure of | |
309 | * draft rfc3448bis, section 4.2. Remember, X is scaled by 2^6. | |
310 | */ | |
311 | if (dp->dccps_syn_rtt) { | |
312 | ccid3_pr_debug("SYN RTT = %uus\n", dp->dccps_syn_rtt); | |
388d5e99 GR |
313 | hctx->tx_rtt = dp->dccps_syn_rtt; |
314 | hctx->tx_x = rfc3390_initial_rate(sk); | |
315 | hctx->tx_t_ld = now; | |
30833ffe | 316 | } else { |
3294f202 GR |
317 | /* |
318 | * Sender does not have RTT sample: | |
319 | * - set fallback RTT (RFC 4340, 3.4) since a RTT value | |
320 | * is needed in several parts (e.g. window counter); | |
321 | * - set sending rate X_pps = 1pps as per RFC 3448, 4.2. | |
322 | */ | |
388d5e99 GR |
323 | hctx->tx_rtt = DCCP_FALLBACK_RTT; |
324 | hctx->tx_x = hctx->tx_s; | |
325 | hctx->tx_x <<= 6; | |
30833ffe GR |
326 | } |
327 | ccid3_update_send_interval(hctx); | |
328 | ||
410e27a4 GR |
329 | ccid3_hc_tx_set_state(sk, TFRC_SSTATE_NO_FBACK); |
330 | break; | |
331 | case TFRC_SSTATE_NO_FBACK: | |
332 | case TFRC_SSTATE_FBACK: | |
388d5e99 | 333 | delay = ktime_us_delta(hctx->tx_t_nom, now); |
8699be7d | 334 | ccid3_pr_debug("delay=%ld\n", (long)delay); |
91cf5a17 | 335 | /* |
8109b02b | 336 | * Scheduling of packet transmissions [RFC 3448, 4.6] |
91cf5a17 GR |
337 | * |
338 | * if (t_now > t_nom - delta) | |
339 | * // send the packet now | |
340 | * else | |
341 | * // send the packet in (t_nom - t_now) milliseconds. | |
342 | */ | |
388d5e99 | 343 | if (delay - (s64)hctx->tx_delta >= 1000) |
410e27a4 | 344 | return (u32)delay / 1000L; |
9f8681db | 345 | |
8132da4d | 346 | ccid3_hc_tx_update_win_count(hctx, now); |
410e27a4 GR |
347 | break; |
348 | case TFRC_SSTATE_TERM: | |
349 | DCCP_BUG("%s(%p) - Illegal state TERM", dccp_role(sk), sk); | |
350 | return -EINVAL; | |
7c657876 ACM |
351 | } |
352 | ||
7da7f456 GR |
353 | /* prepare to send now (add options etc.) */ |
354 | dp->dccps_hc_tx_insert_options = 1; | |
388d5e99 | 355 | DCCP_SKB_CB(skb)->dccpd_ccval = hctx->tx_last_win_count; |
e312d100 GR |
356 | |
357 | /* set the nominal send time for the next following packet */ | |
388d5e99 | 358 | hctx->tx_t_nom = ktime_add_us(hctx->tx_t_nom, hctx->tx_t_ipi); |
410e27a4 | 359 | return 0; |
7c657876 ACM |
360 | } |
361 | ||
410e27a4 GR |
362 | static void ccid3_hc_tx_packet_sent(struct sock *sk, int more, |
363 | unsigned int len) | |
7c657876 | 364 | { |
59725dc2 | 365 | struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); |
7c657876 | 366 | |
410e27a4 | 367 | ccid3_hc_tx_update_s(hctx, len); |
7c657876 | 368 | |
388d5e99 | 369 | if (tfrc_tx_hist_add(&hctx->tx_hist, dccp_sk(sk)->dccps_gss)) |
c5a1ae9a | 370 | DCCP_CRIT("packet history - out of memory!"); |
7c657876 ACM |
371 | } |
372 | ||
373 | static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) | |
374 | { | |
59725dc2 | 375 | struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); |
410e27a4 | 376 | struct ccid3_options_received *opt_recv; |
0740d49c | 377 | ktime_t now; |
2a1fda6f | 378 | unsigned long t_nfb; |
410e27a4 | 379 | u32 pinv, r_sample; |
1f2333ae | 380 | |
7c657876 ACM |
381 | /* we are only interested in ACKs */ |
382 | if (!(DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_ACK || | |
383 | DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_DATAACK)) | |
384 | return; | |
410e27a4 | 385 | /* ... and only in the established state */ |
388d5e99 GR |
386 | if (hctx->tx_state != TFRC_SSTATE_FBACK && |
387 | hctx->tx_state != TFRC_SSTATE_NO_FBACK) | |
410e27a4 GR |
388 | return; |
389 | ||
388d5e99 | 390 | opt_recv = &hctx->tx_options_received; |
410e27a4 GR |
391 | now = ktime_get_real(); |
392 | ||
393 | /* Estimate RTT from history if ACK number is valid */ | |
388d5e99 | 394 | r_sample = tfrc_tx_hist_rtt(hctx->tx_hist, |
410e27a4 GR |
395 | DCCP_SKB_CB(skb)->dccpd_ack_seq, now); |
396 | if (r_sample == 0) { | |
397 | DCCP_WARN("%s(%p): %s with bogus ACK-%llu\n", dccp_role(sk), sk, | |
398 | dccp_packet_name(DCCP_SKB_CB(skb)->dccpd_type), | |
399 | (unsigned long long)DCCP_SKB_CB(skb)->dccpd_ack_seq); | |
5bd370a6 | 400 | return; |
410e27a4 | 401 | } |
63b3a73b | 402 | |
410e27a4 | 403 | /* Update receive rate in units of 64 * bytes/second */ |
388d5e99 GR |
404 | hctx->tx_x_recv = opt_recv->ccid3or_receive_rate; |
405 | hctx->tx_x_recv <<= 6; | |
7c657876 | 406 | |
410e27a4 GR |
407 | /* Update loss event rate (which is scaled by 1e6) */ |
408 | pinv = opt_recv->ccid3or_loss_event_rate; | |
409 | if (pinv == ~0U || pinv == 0) /* see RFC 4342, 8.5 */ | |
388d5e99 | 410 | hctx->tx_p = 0; |
410e27a4 | 411 | else /* can not exceed 100% */ |
388d5e99 | 412 | hctx->tx_p = scaled_div(1, pinv); |
410e27a4 GR |
413 | /* |
414 | * Validate new RTT sample and update moving average | |
415 | */ | |
416 | r_sample = dccp_sample_rtt(sk, r_sample); | |
388d5e99 | 417 | hctx->tx_rtt = tfrc_ewma(hctx->tx_rtt, r_sample, 9); |
d8d1252f GR |
418 | /* |
419 | * Update allowed sending rate X as per draft rfc3448bis-00, 4.2/3 | |
420 | */ | |
388d5e99 | 421 | if (hctx->tx_state == TFRC_SSTATE_NO_FBACK) { |
410e27a4 | 422 | ccid3_hc_tx_set_state(sk, TFRC_SSTATE_FBACK); |
5c3fbb6a | 423 | |
388d5e99 | 424 | if (hctx->tx_t_rto == 0) { |
d8d1252f GR |
425 | /* |
426 | * Initial feedback packet: Larger Initial Windows (4.2) | |
427 | */ | |
388d5e99 GR |
428 | hctx->tx_x = rfc3390_initial_rate(sk); |
429 | hctx->tx_t_ld = now; | |
a79ef76f | 430 | |
d8d1252f | 431 | ccid3_update_send_interval(hctx); |
7c657876 | 432 | |
d8d1252f | 433 | goto done_computing_x; |
388d5e99 | 434 | } else if (hctx->tx_p == 0) { |
d8d1252f GR |
435 | /* |
436 | * First feedback after nofeedback timer expiry (4.3) | |
437 | */ | |
438 | goto done_computing_x; | |
439 | } | |
440 | } | |
7c657876 | 441 | |
d8d1252f | 442 | /* Update sending rate (step 4 of [RFC 3448, 4.3]) */ |
388d5e99 GR |
443 | if (hctx->tx_p > 0) |
444 | hctx->tx_x_calc = tfrc_calc_x(hctx->tx_s, hctx->tx_rtt, hctx->tx_p); | |
d8d1252f | 445 | ccid3_hc_tx_update_x(sk, &now); |
7c657876 | 446 | |
d8d1252f GR |
447 | done_computing_x: |
448 | ccid3_pr_debug("%s(%p), RTT=%uus (sample=%uus), s=%u, " | |
5bd370a6 | 449 | "p=%u, X_calc=%u, X_recv=%u, X=%u\n", |
388d5e99 GR |
450 | dccp_role(sk), sk, hctx->tx_rtt, r_sample, |
451 | hctx->tx_s, hctx->tx_p, hctx->tx_x_calc, | |
452 | (unsigned)(hctx->tx_x_recv >> 6), | |
453 | (unsigned)(hctx->tx_x >> 6)); | |
7c657876 | 454 | |
5bd370a6 | 455 | /* unschedule no feedback timer */ |
388d5e99 | 456 | sk_stop_timer(sk, &hctx->tx_no_feedback_timer); |
7c657876 | 457 | |
5bd370a6 GR |
458 | /* |
459 | * As we have calculated new ipi, delta, t_nom it is possible | |
460 | * that we now can send a packet, so wake up dccp_wait_for_ccid | |
461 | */ | |
462 | sk->sk_write_space(sk); | |
8c60f3fa | 463 | |
5bd370a6 GR |
464 | /* |
465 | * Update timeout interval for the nofeedback timer. | |
466 | * We use a configuration option to increase the lower bound. | |
467 | * This can help avoid triggering the nofeedback timer too | |
468 | * often ('spinning') on LANs with small RTTs. | |
469 | */ | |
388d5e99 GR |
470 | hctx->tx_t_rto = max_t(u32, 4 * hctx->tx_rtt, (CONFIG_IP_DCCP_CCID3_RTO * |
471 | (USEC_PER_SEC / 1000))); | |
5bd370a6 GR |
472 | /* |
473 | * Schedule no feedback timer to expire in | |
474 | * max(t_RTO, 2 * s/X) = max(t_RTO, 2 * t_ipi) | |
475 | */ | |
388d5e99 | 476 | t_nfb = max(hctx->tx_t_rto, 2 * hctx->tx_t_ipi); |
7c657876 | 477 | |
5bd370a6 GR |
478 | ccid3_pr_debug("%s(%p), Scheduled no feedback timer to " |
479 | "expire in %lu jiffies (%luus)\n", | |
388d5e99 | 480 | dccp_role(sk), sk, usecs_to_jiffies(t_nfb), t_nfb); |
a9672411 | 481 | |
388d5e99 | 482 | sk_reset_timer(sk, &hctx->tx_no_feedback_timer, |
5bd370a6 | 483 | jiffies + usecs_to_jiffies(t_nfb)); |
7c657876 ACM |
484 | } |
485 | ||
410e27a4 GR |
486 | static int ccid3_hc_tx_parse_options(struct sock *sk, unsigned char option, |
487 | unsigned char len, u16 idx, | |
488 | unsigned char *value) | |
7c657876 | 489 | { |
410e27a4 GR |
490 | int rc = 0; |
491 | const struct dccp_sock *dp = dccp_sk(sk); | |
59725dc2 | 492 | struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); |
410e27a4 | 493 | struct ccid3_options_received *opt_recv; |
76fd1e87 | 494 | __be32 opt_val; |
7c657876 | 495 | |
388d5e99 | 496 | opt_recv = &hctx->tx_options_received; |
47a61e7b | 497 | |
410e27a4 GR |
498 | if (opt_recv->ccid3or_seqno != dp->dccps_gsr) { |
499 | opt_recv->ccid3or_seqno = dp->dccps_gsr; | |
500 | opt_recv->ccid3or_loss_event_rate = ~0; | |
501 | opt_recv->ccid3or_loss_intervals_idx = 0; | |
502 | opt_recv->ccid3or_loss_intervals_len = 0; | |
503 | opt_recv->ccid3or_receive_rate = 0; | |
504 | } | |
ce177ae2 | 505 | |
410e27a4 GR |
506 | switch (option) { |
507 | case TFRC_OPT_LOSS_EVENT_RATE: | |
508 | if (unlikely(len != 4)) { | |
509 | DCCP_WARN("%s(%p), invalid len %d " | |
510 | "for TFRC_OPT_LOSS_EVENT_RATE\n", | |
511 | dccp_role(sk), sk, len); | |
512 | rc = -EINVAL; | |
47a61e7b | 513 | } else { |
410e27a4 GR |
514 | opt_val = get_unaligned((__be32 *)value); |
515 | opt_recv->ccid3or_loss_event_rate = ntohl(opt_val); | |
47a61e7b | 516 | ccid3_pr_debug("%s(%p), LOSS_EVENT_RATE=%u\n", |
410e27a4 GR |
517 | dccp_role(sk), sk, |
518 | opt_recv->ccid3or_loss_event_rate); | |
7c657876 | 519 | } |
410e27a4 GR |
520 | break; |
521 | case TFRC_OPT_LOSS_INTERVALS: | |
522 | opt_recv->ccid3or_loss_intervals_idx = idx; | |
523 | opt_recv->ccid3or_loss_intervals_len = len; | |
524 | ccid3_pr_debug("%s(%p), LOSS_INTERVALS=(%u, %u)\n", | |
525 | dccp_role(sk), sk, | |
526 | opt_recv->ccid3or_loss_intervals_idx, | |
527 | opt_recv->ccid3or_loss_intervals_len); | |
528 | break; | |
529 | case TFRC_OPT_RECEIVE_RATE: | |
530 | if (unlikely(len != 4)) { | |
531 | DCCP_WARN("%s(%p), invalid len %d " | |
532 | "for TFRC_OPT_RECEIVE_RATE\n", | |
533 | dccp_role(sk), sk, len); | |
534 | rc = -EINVAL; | |
535 | } else { | |
536 | opt_val = get_unaligned((__be32 *)value); | |
537 | opt_recv->ccid3or_receive_rate = ntohl(opt_val); | |
538 | ccid3_pr_debug("%s(%p), RECEIVE_RATE=%u\n", | |
539 | dccp_role(sk), sk, | |
540 | opt_recv->ccid3or_receive_rate); | |
541 | } | |
542 | break; | |
7c657876 | 543 | } |
410e27a4 GR |
544 | |
545 | return rc; | |
7c657876 ACM |
546 | } |
547 | ||
91f0ebf7 | 548 | static int ccid3_hc_tx_init(struct ccid *ccid, struct sock *sk) |
7c657876 | 549 | { |
91f0ebf7 | 550 | struct ccid3_hc_tx_sock *hctx = ccid_priv(ccid); |
7c657876 | 551 | |
388d5e99 GR |
552 | hctx->tx_state = TFRC_SSTATE_NO_SENT; |
553 | hctx->tx_hist = NULL; | |
554 | setup_timer(&hctx->tx_no_feedback_timer, | |
410e27a4 | 555 | ccid3_hc_tx_no_feedback_timer, (unsigned long)sk); |
7c657876 ACM |
556 | return 0; |
557 | } | |
558 | ||
559 | static void ccid3_hc_tx_exit(struct sock *sk) | |
560 | { | |
59725dc2 | 561 | struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); |
7c657876 | 562 | |
410e27a4 | 563 | ccid3_hc_tx_set_state(sk, TFRC_SSTATE_TERM); |
388d5e99 | 564 | sk_stop_timer(sk, &hctx->tx_no_feedback_timer); |
410e27a4 | 565 | |
388d5e99 | 566 | tfrc_tx_hist_purge(&hctx->tx_hist); |
7c657876 ACM |
567 | } |
568 | ||
9bf17475 GR |
569 | static void ccid3_hc_tx_get_info(struct sock *sk, struct tcp_info *info) |
570 | { | |
410e27a4 GR |
571 | struct ccid3_hc_tx_sock *hctx; |
572 | ||
573 | /* Listen socks doesn't have a private CCID block */ | |
574 | if (sk->sk_state == DCCP_LISTEN) | |
575 | return; | |
576 | ||
577 | hctx = ccid3_hc_tx_sk(sk); | |
388d5e99 GR |
578 | info->tcpi_rto = hctx->tx_t_rto; |
579 | info->tcpi_rtt = hctx->tx_rtt; | |
9bf17475 GR |
580 | } |
581 | ||
582 | static int ccid3_hc_tx_getsockopt(struct sock *sk, const int optname, int len, | |
583 | u32 __user *optval, int __user *optlen) | |
584 | { | |
410e27a4 | 585 | const struct ccid3_hc_tx_sock *hctx; |
9bf17475 GR |
586 | const void *val; |
587 | ||
410e27a4 GR |
588 | /* Listen socks doesn't have a private CCID block */ |
589 | if (sk->sk_state == DCCP_LISTEN) | |
590 | return -EINVAL; | |
591 | ||
592 | hctx = ccid3_hc_tx_sk(sk); | |
9bf17475 GR |
593 | switch (optname) { |
594 | case DCCP_SOCKOPT_CCID_TX_INFO: | |
388d5e99 | 595 | if (len < sizeof(hctx->tx_tfrc)) |
9bf17475 | 596 | return -EINVAL; |
388d5e99 GR |
597 | len = sizeof(hctx->tx_tfrc); |
598 | val = &hctx->tx_tfrc; | |
9bf17475 GR |
599 | break; |
600 | default: | |
601 | return -ENOPROTOOPT; | |
602 | } | |
603 | ||
604 | if (put_user(len, optlen) || copy_to_user(optval, val, len)) | |
605 | return -EFAULT; | |
606 | ||
607 | return 0; | |
608 | } | |
609 | ||
7c657876 | 610 | /* |
9bf17475 | 611 | * Receiver Half-Connection Routines |
7c657876 | 612 | */ |
410e27a4 GR |
613 | |
614 | /* CCID3 feedback types */ | |
615 | enum ccid3_fback_type { | |
616 | CCID3_FBACK_NONE = 0, | |
617 | CCID3_FBACK_INITIAL, | |
618 | CCID3_FBACK_PERIODIC, | |
619 | CCID3_FBACK_PARAM_CHANGE | |
620 | }; | |
621 | ||
622 | #ifdef CONFIG_IP_DCCP_CCID3_DEBUG | |
623 | static const char *ccid3_rx_state_name(enum ccid3_hc_rx_states state) | |
624 | { | |
36cbd3dc | 625 | static const char *const ccid3_rx_state_names[] = { |
410e27a4 GR |
626 | [TFRC_RSTATE_NO_DATA] = "NO_DATA", |
627 | [TFRC_RSTATE_DATA] = "DATA", | |
628 | [TFRC_RSTATE_TERM] = "TERM", | |
629 | }; | |
630 | ||
631 | return ccid3_rx_state_names[state]; | |
632 | } | |
633 | #endif | |
634 | ||
635 | static void ccid3_hc_rx_set_state(struct sock *sk, | |
636 | enum ccid3_hc_rx_states state) | |
637 | { | |
638 | struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk); | |
388d5e99 | 639 | enum ccid3_hc_rx_states oldstate = hcrx->rx_state; |
410e27a4 GR |
640 | |
641 | ccid3_pr_debug("%s(%p) %-8.8s -> %s\n", | |
642 | dccp_role(sk), sk, ccid3_rx_state_name(oldstate), | |
643 | ccid3_rx_state_name(state)); | |
644 | WARN_ON(state == oldstate); | |
388d5e99 | 645 | hcrx->rx_state = state; |
410e27a4 GR |
646 | } |
647 | ||
b84a2189 ACM |
648 | static void ccid3_hc_rx_send_feedback(struct sock *sk, |
649 | const struct sk_buff *skb, | |
650 | enum ccid3_fback_type fbtype) | |
7c657876 | 651 | { |
59725dc2 | 652 | struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk); |
410e27a4 GR |
653 | struct dccp_sock *dp = dccp_sk(sk); |
654 | ktime_t now; | |
655 | s64 delta = 0; | |
656 | ||
388d5e99 | 657 | if (unlikely(hcrx->rx_state == TFRC_RSTATE_TERM)) |
410e27a4 GR |
658 | return; |
659 | ||
660 | now = ktime_get_real(); | |
7c657876 | 661 | |
b84a2189 ACM |
662 | switch (fbtype) { |
663 | case CCID3_FBACK_INITIAL: | |
388d5e99 GR |
664 | hcrx->rx_x_recv = 0; |
665 | hcrx->rx_pinv = ~0U; /* see RFC 4342, 8.5 */ | |
7c657876 | 666 | break; |
b84a2189 ACM |
667 | case CCID3_FBACK_PARAM_CHANGE: |
668 | /* | |
669 | * When parameters change (new loss or p > p_prev), we do not | |
670 | * have a reliable estimate for R_m of [RFC 3448, 6.2] and so | |
410e27a4 GR |
671 | * need to reuse the previous value of X_recv. However, when |
672 | * X_recv was 0 (due to early loss), this would kill X down to | |
673 | * s/t_mbi (i.e. one packet in 64 seconds). | |
674 | * To avoid such drastic reduction, we approximate X_recv as | |
675 | * the number of bytes since last feedback. | |
676 | * This is a safe fallback, since X is bounded above by X_calc. | |
b84a2189 | 677 | */ |
388d5e99 | 678 | if (hcrx->rx_x_recv > 0) |
410e27a4 GR |
679 | break; |
680 | /* fall through */ | |
b84a2189 | 681 | case CCID3_FBACK_PERIODIC: |
388d5e99 | 682 | delta = ktime_us_delta(now, hcrx->rx_tstamp_last_feedback); |
410e27a4 GR |
683 | if (delta <= 0) |
684 | DCCP_BUG("delta (%ld) <= 0", (long)delta); | |
685 | else | |
388d5e99 | 686 | hcrx->rx_x_recv = scaled_div32(hcrx->rx_bytes_recv, delta); |
7c657876 | 687 | break; |
b84a2189 | 688 | default: |
7c657876 ACM |
689 | return; |
690 | } | |
691 | ||
410e27a4 | 692 | ccid3_pr_debug("Interval %ldusec, X_recv=%u, 1/p=%u\n", (long)delta, |
388d5e99 | 693 | hcrx->rx_x_recv, hcrx->rx_pinv); |
7c657876 | 694 | |
388d5e99 GR |
695 | hcrx->rx_tstamp_last_feedback = now; |
696 | hcrx->rx_last_counter = dccp_hdr(skb)->dccph_ccval; | |
697 | hcrx->rx_bytes_recv = 0; | |
68c89ee5 | 698 | |
410e27a4 GR |
699 | dp->dccps_hc_rx_insert_options = 1; |
700 | dccp_send_ack(sk); | |
7c657876 ACM |
701 | } |
702 | ||
2d0817d1 | 703 | static int ccid3_hc_rx_insert_options(struct sock *sk, struct sk_buff *skb) |
7c657876 | 704 | { |
410e27a4 | 705 | const struct ccid3_hc_rx_sock *hcrx; |
60fe62e7 | 706 | __be32 x_recv, pinv; |
7c657876 | 707 | |
59d203f9 | 708 | if (!(sk->sk_state == DCCP_OPEN || sk->sk_state == DCCP_PARTOPEN)) |
2d0817d1 | 709 | return 0; |
7c657876 | 710 | |
410e27a4 GR |
711 | hcrx = ccid3_hc_rx_sk(sk); |
712 | ||
4fded33b | 713 | if (dccp_packet_without_ack(skb)) |
2d0817d1 ACM |
714 | return 0; |
715 | ||
388d5e99 GR |
716 | x_recv = htonl(hcrx->rx_x_recv); |
717 | pinv = htonl(hcrx->rx_pinv); | |
2d0817d1 | 718 | |
385ac2e3 | 719 | if (dccp_insert_option(sk, skb, TFRC_OPT_LOSS_EVENT_RATE, |
8109b02b | 720 | &pinv, sizeof(pinv)) || |
2d0817d1 | 721 | dccp_insert_option(sk, skb, TFRC_OPT_RECEIVE_RATE, |
8109b02b | 722 | &x_recv, sizeof(x_recv))) |
2d0817d1 ACM |
723 | return -1; |
724 | ||
725 | return 0; | |
7c657876 ACM |
726 | } |
727 | ||
aa1b1ff0 GR |
728 | /** |
729 | * ccid3_first_li - Implements [RFC 5348, 6.3.1] | |
954c2db8 GR |
730 | * |
731 | * Determine the length of the first loss interval via inverse lookup. | |
732 | * Assume that X_recv can be computed by the throughput equation | |
733 | * s | |
734 | * X_recv = -------- | |
735 | * R * fval | |
736 | * Find some p such that f(p) = fval; return 1/p (scaled). | |
737 | */ | |
738 | static u32 ccid3_first_li(struct sock *sk) | |
739 | { | |
740 | struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk); | |
410e27a4 | 741 | u32 x_recv, p, delta; |
954c2db8 GR |
742 | u64 fval; |
743 | ||
388d5e99 | 744 | if (hcrx->rx_rtt == 0) { |
410e27a4 | 745 | DCCP_WARN("No RTT estimate available, using fallback RTT\n"); |
388d5e99 | 746 | hcrx->rx_rtt = DCCP_FALLBACK_RTT; |
410e27a4 | 747 | } |
d20ed95f | 748 | |
388d5e99 GR |
749 | delta = ktime_to_us(net_timedelta(hcrx->rx_tstamp_last_feedback)); |
750 | x_recv = scaled_div32(hcrx->rx_bytes_recv, delta); | |
410e27a4 GR |
751 | if (x_recv == 0) { /* would also trigger divide-by-zero */ |
752 | DCCP_WARN("X_recv==0\n"); | |
388d5e99 | 753 | if ((x_recv = hcrx->rx_x_recv) == 0) { |
410e27a4 GR |
754 | DCCP_BUG("stored value of X_recv is zero"); |
755 | return ~0U; | |
756 | } | |
757 | } | |
954c2db8 | 758 | |
388d5e99 | 759 | fval = scaled_div(hcrx->rx_s, hcrx->rx_rtt); |
410e27a4 | 760 | fval = scaled_div32(fval, x_recv); |
954c2db8 GR |
761 | p = tfrc_calc_x_reverse_lookup(fval); |
762 | ||
763 | ccid3_pr_debug("%s(%p), receive rate=%u bytes/s, implied " | |
764 | "loss rate=%u\n", dccp_role(sk), sk, x_recv, p); | |
765 | ||
410e27a4 | 766 | return p == 0 ? ~0U : scaled_div(1, p); |
954c2db8 GR |
767 | } |
768 | ||
b84a2189 | 769 | static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb) |
7c657876 | 770 | { |
59725dc2 | 771 | struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk); |
410e27a4 | 772 | enum ccid3_fback_type do_feedback = CCID3_FBACK_NONE; |
5b5d0e70 | 773 | const u64 ndp = dccp_sk(sk)->dccps_options_received.dccpor_ndp; |
b84a2189 ACM |
774 | const bool is_data_packet = dccp_data_packet(skb); |
775 | ||
388d5e99 | 776 | if (unlikely(hcrx->rx_state == TFRC_RSTATE_NO_DATA)) { |
410e27a4 GR |
777 | if (is_data_packet) { |
778 | const u32 payload = skb->len - dccp_hdr(skb)->dccph_doff * 4; | |
779 | do_feedback = CCID3_FBACK_INITIAL; | |
780 | ccid3_hc_rx_set_state(sk, TFRC_RSTATE_DATA); | |
388d5e99 | 781 | hcrx->rx_s = payload; |
410e27a4 | 782 | /* |
388d5e99 | 783 | * Not necessary to update rx_bytes_recv here, |
410e27a4 GR |
784 | * since X_recv = 0 for the first feedback packet (cf. |
785 | * RFC 3448, 6.3) -- gerrit | |
786 | */ | |
787 | } | |
788 | goto update_records; | |
789 | } | |
790 | ||
388d5e99 | 791 | if (tfrc_rx_hist_duplicate(&hcrx->rx_hist, skb)) |
410e27a4 GR |
792 | return; /* done receiving */ |
793 | ||
794 | if (is_data_packet) { | |
795 | const u32 payload = skb->len - dccp_hdr(skb)->dccph_doff * 4; | |
796 | /* | |
797 | * Update moving-average of s and the sum of received payload bytes | |
798 | */ | |
388d5e99 GR |
799 | hcrx->rx_s = tfrc_ewma(hcrx->rx_s, payload, 9); |
800 | hcrx->rx_bytes_recv += payload; | |
410e27a4 GR |
801 | } |
802 | ||
d20ed95f GR |
803 | /* |
804 | * Perform loss detection and handle pending losses | |
805 | */ | |
388d5e99 | 806 | if (tfrc_rx_handle_loss(&hcrx->rx_hist, &hcrx->rx_li_hist, |
410e27a4 GR |
807 | skb, ndp, ccid3_first_li, sk)) { |
808 | do_feedback = CCID3_FBACK_PARAM_CHANGE; | |
809 | goto done_receiving; | |
810 | } | |
811 | ||
388d5e99 | 812 | if (tfrc_rx_hist_loss_pending(&hcrx->rx_hist)) |
410e27a4 GR |
813 | return; /* done receiving */ |
814 | ||
88e97a93 | 815 | /* |
410e27a4 | 816 | * Handle data packets: RTT sampling and monitoring p |
88e97a93 | 817 | */ |
410e27a4 GR |
818 | if (unlikely(!is_data_packet)) |
819 | goto update_records; | |
820 | ||
388d5e99 GR |
821 | if (!tfrc_lh_is_initialised(&hcrx->rx_li_hist)) { |
822 | const u32 sample = tfrc_rx_hist_sample_rtt(&hcrx->rx_hist, skb); | |
410e27a4 GR |
823 | /* |
824 | * Empty loss history: no loss so far, hence p stays 0. | |
825 | * Sample RTT values, since an RTT estimate is required for the | |
826 | * computation of p when the first loss occurs; RFC 3448, 6.3.1. | |
827 | */ | |
828 | if (sample != 0) | |
388d5e99 | 829 | hcrx->rx_rtt = tfrc_ewma(hcrx->rx_rtt, sample, 9); |
410e27a4 | 830 | |
388d5e99 | 831 | } else if (tfrc_lh_update_i_mean(&hcrx->rx_li_hist, skb)) { |
410e27a4 GR |
832 | /* |
833 | * Step (3) of [RFC 3448, 6.1]: Recompute I_mean and, if I_mean | |
834 | * has decreased (resp. p has increased), send feedback now. | |
835 | */ | |
836 | do_feedback = CCID3_FBACK_PARAM_CHANGE; | |
837 | } | |
838 | ||
b84a2189 ACM |
839 | /* |
840 | * Check if the periodic once-per-RTT feedback is due; RFC 4342, 10.3 | |
841 | */ | |
388d5e99 | 842 | if (SUB16(dccp_hdr(skb)->dccph_ccval, hcrx->rx_last_counter) > 3) |
410e27a4 GR |
843 | do_feedback = CCID3_FBACK_PERIODIC; |
844 | ||
845 | update_records: | |
388d5e99 | 846 | tfrc_rx_hist_add_packet(&hcrx->rx_hist, skb, ndp); |
410e27a4 GR |
847 | |
848 | done_receiving: | |
849 | if (do_feedback) | |
850 | ccid3_hc_rx_send_feedback(sk, skb, do_feedback); | |
7c657876 ACM |
851 | } |
852 | ||
91f0ebf7 | 853 | static int ccid3_hc_rx_init(struct ccid *ccid, struct sock *sk) |
7c657876 | 854 | { |
91f0ebf7 | 855 | struct ccid3_hc_rx_sock *hcrx = ccid_priv(ccid); |
7c657876 | 856 | |
388d5e99 GR |
857 | hcrx->rx_state = TFRC_RSTATE_NO_DATA; |
858 | tfrc_lh_init(&hcrx->rx_li_hist); | |
859 | return tfrc_rx_hist_alloc(&hcrx->rx_hist); | |
7c657876 ACM |
860 | } |
861 | ||
862 | static void ccid3_hc_rx_exit(struct sock *sk) | |
863 | { | |
59725dc2 | 864 | struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk); |
7c657876 | 865 | |
410e27a4 GR |
866 | ccid3_hc_rx_set_state(sk, TFRC_RSTATE_TERM); |
867 | ||
388d5e99 GR |
868 | tfrc_rx_hist_purge(&hcrx->rx_hist); |
869 | tfrc_lh_cleanup(&hcrx->rx_li_hist); | |
7c657876 ACM |
870 | } |
871 | ||
2babe1f6 ACM |
872 | static void ccid3_hc_rx_get_info(struct sock *sk, struct tcp_info *info) |
873 | { | |
410e27a4 GR |
874 | const struct ccid3_hc_rx_sock *hcrx; |
875 | ||
876 | /* Listen socks doesn't have a private CCID block */ | |
877 | if (sk->sk_state == DCCP_LISTEN) | |
878 | return; | |
879 | ||
880 | hcrx = ccid3_hc_rx_sk(sk); | |
388d5e99 | 881 | info->tcpi_ca_state = hcrx->rx_state; |
8109b02b | 882 | info->tcpi_options |= TCPI_OPT_TIMESTAMPS; |
388d5e99 | 883 | info->tcpi_rcv_rtt = hcrx->rx_rtt; |
2babe1f6 ACM |
884 | } |
885 | ||
88f964db ACM |
886 | static int ccid3_hc_rx_getsockopt(struct sock *sk, const int optname, int len, |
887 | u32 __user *optval, int __user *optlen) | |
888 | { | |
410e27a4 | 889 | const struct ccid3_hc_rx_sock *hcrx; |
8e138e79 | 890 | struct tfrc_rx_info rx_info; |
88f964db | 891 | const void *val; |
c9eaf173 | 892 | |
410e27a4 GR |
893 | /* Listen socks doesn't have a private CCID block */ |
894 | if (sk->sk_state == DCCP_LISTEN) | |
895 | return -EINVAL; | |
896 | ||
897 | hcrx = ccid3_hc_rx_sk(sk); | |
88f964db ACM |
898 | switch (optname) { |
899 | case DCCP_SOCKOPT_CCID_RX_INFO: | |
8e138e79 | 900 | if (len < sizeof(rx_info)) |
88f964db | 901 | return -EINVAL; |
388d5e99 GR |
902 | rx_info.tfrcrx_x_recv = hcrx->rx_x_recv; |
903 | rx_info.tfrcrx_rtt = hcrx->rx_rtt; | |
904 | rx_info.tfrcrx_p = hcrx->rx_pinv == 0 ? ~0U : | |
905 | scaled_div(1, hcrx->rx_pinv); | |
8e138e79 GR |
906 | len = sizeof(rx_info); |
907 | val = &rx_info; | |
88f964db ACM |
908 | break; |
909 | default: | |
910 | return -ENOPROTOOPT; | |
911 | } | |
912 | ||
913 | if (put_user(len, optlen) || copy_to_user(optval, val, len)) | |
914 | return -EFAULT; | |
915 | ||
916 | return 0; | |
917 | } | |
918 | ||
ddebc973 | 919 | struct ccid_operations ccid3_ops = { |
3dd9a7c3 | 920 | .ccid_id = DCCPC_CCID3, |
84a97b0a | 921 | .ccid_name = "TCP-Friendly Rate Control", |
91f0ebf7 | 922 | .ccid_hc_tx_obj_size = sizeof(struct ccid3_hc_tx_sock), |
7c657876 ACM |
923 | .ccid_hc_tx_init = ccid3_hc_tx_init, |
924 | .ccid_hc_tx_exit = ccid3_hc_tx_exit, | |
925 | .ccid_hc_tx_send_packet = ccid3_hc_tx_send_packet, | |
926 | .ccid_hc_tx_packet_sent = ccid3_hc_tx_packet_sent, | |
927 | .ccid_hc_tx_packet_recv = ccid3_hc_tx_packet_recv, | |
7c657876 | 928 | .ccid_hc_tx_parse_options = ccid3_hc_tx_parse_options, |
91f0ebf7 | 929 | .ccid_hc_rx_obj_size = sizeof(struct ccid3_hc_rx_sock), |
7c657876 ACM |
930 | .ccid_hc_rx_init = ccid3_hc_rx_init, |
931 | .ccid_hc_rx_exit = ccid3_hc_rx_exit, | |
932 | .ccid_hc_rx_insert_options = ccid3_hc_rx_insert_options, | |
933 | .ccid_hc_rx_packet_recv = ccid3_hc_rx_packet_recv, | |
2babe1f6 ACM |
934 | .ccid_hc_rx_get_info = ccid3_hc_rx_get_info, |
935 | .ccid_hc_tx_get_info = ccid3_hc_tx_get_info, | |
88f964db ACM |
936 | .ccid_hc_rx_getsockopt = ccid3_hc_rx_getsockopt, |
937 | .ccid_hc_tx_getsockopt = ccid3_hc_tx_getsockopt, | |
7c657876 | 938 | }; |
8109b02b | 939 | |
56724aa4 | 940 | #ifdef CONFIG_IP_DCCP_CCID3_DEBUG |
43264991 | 941 | module_param(ccid3_debug, bool, 0644); |
ddebc973 | 942 | MODULE_PARM_DESC(ccid3_debug, "Enable CCID-3 debug messages"); |
56724aa4 | 943 | #endif |