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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 | */ | |
410e27a4 GR |
52 | #ifdef CONFIG_IP_DCCP_CCID3_DEBUG |
53 | static const char *ccid3_tx_state_name(enum ccid3_hc_tx_states state) | |
54 | { | |
36cbd3dc | 55 | static const char *const ccid3_state_names[] = { |
410e27a4 GR |
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 | ||
66 | static void ccid3_hc_tx_set_state(struct sock *sk, | |
67 | enum ccid3_hc_tx_states state) | |
68 | { | |
69 | struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); | |
70 | enum ccid3_hc_tx_states oldstate = hctx->ccid3hctx_state; | |
71 | ||
72 | ccid3_pr_debug("%s(%p) %-8.8s -> %s\n", | |
73 | dccp_role(sk), sk, ccid3_tx_state_name(oldstate), | |
74 | ccid3_tx_state_name(state)); | |
75 | WARN_ON(state == oldstate); | |
76 | hctx->ccid3hctx_state = state; | |
77 | } | |
7c657876 | 78 | |
a21f9f96 | 79 | /* |
6c08b2cf GR |
80 | * Compute the initial sending rate X_init in the manner of RFC 3390: |
81 | * | |
410e27a4 | 82 | * X_init = min(4 * s, max(2 * s, 4380 bytes)) / RTT |
6c08b2cf | 83 | * |
410e27a4 GR |
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 | { | |
410e27a4 GR |
90 | const struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); |
91 | const __u32 w_init = clamp_t(__u32, 4380U, | |
92 | 2 * hctx->ccid3hctx_s, 4 * hctx->ccid3hctx_s); | |
a21f9f96 | 93 | |
410e27a4 | 94 | return scaled_div(w_init << 6, hctx->ccid3hctx_rtt); |
a21f9f96 GR |
95 | } |
96 | ||
410e27a4 GR |
97 | /* |
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 | { |
410e27a4 GR |
102 | /* Calculate new t_ipi = s / X_inst (X_inst is in 64 * bytes/second) */ |
103 | hctx->ccid3hctx_t_ipi = scaled_div32(((u64)hctx->ccid3hctx_s) << 6, | |
104 | hctx->ccid3hctx_x); | |
105 | ||
106 | /* Calculate new delta by delta = min(t_ipi / 2, t_gran / 2) */ | |
107 | hctx->ccid3hctx_delta = min_t(u32, hctx->ccid3hctx_t_ipi / 2, | |
108 | TFRC_OPSYS_HALF_TIME_GRAN); | |
109 | ||
110 | ccid3_pr_debug("t_ipi=%u, delta=%u, s=%u, X=%u\n", | |
111 | hctx->ccid3hctx_t_ipi, hctx->ccid3hctx_delta, | |
112 | hctx->ccid3hctx_s, (unsigned)(hctx->ccid3hctx_x >> 6)); | |
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 | { | |
410e27a4 | 118 | u32 delta = ktime_us_delta(now, hctx->ccid3hctx_t_last_win_count); |
a5358fdc | 119 | |
410e27a4 | 120 | return delta / hctx->ccid3hctx_rtt; |
a5358fdc GR |
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); |
410e27a4 GR |
136 | __u64 min_rate = 2 * hctx->ccid3hctx_x_recv; |
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 | 147 | min_rate = rfc3390_initial_rate(sk); |
410e27a4 | 148 | min_rate = max(min_rate, 2 * hctx->ccid3hctx_x_recv); |
0c150efb GR |
149 | } |
150 | ||
410e27a4 | 151 | if (hctx->ccid3hctx_p > 0) { |
1a21e49a | 152 | |
410e27a4 GR |
153 | hctx->ccid3hctx_x = min(((__u64)hctx->ccid3hctx_x_calc) << 6, |
154 | min_rate); | |
155 | hctx->ccid3hctx_x = max(hctx->ccid3hctx_x, | |
156 | (((__u64)hctx->ccid3hctx_s) << 6) / | |
157 | TFRC_T_MBI); | |
a79ef76f | 158 | |
410e27a4 GR |
159 | } else if (ktime_us_delta(now, hctx->ccid3hctx_t_ld) |
160 | - (s64)hctx->ccid3hctx_rtt >= 0) { | |
ac198ea8 | 161 | |
410e27a4 GR |
162 | hctx->ccid3hctx_x = min(2 * hctx->ccid3hctx_x, min_rate); |
163 | hctx->ccid3hctx_x = max(hctx->ccid3hctx_x, | |
164 | scaled_div(((__u64)hctx->ccid3hctx_s) << 6, | |
165 | hctx->ccid3hctx_rtt)); | |
166 | hctx->ccid3hctx_t_ld = now; | |
ff586298 | 167 | } |
b6ee3d4a | 168 | |
410e27a4 | 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), | |
410e27a4 GR |
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 | /* |
410e27a4 GR |
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 | 183 | */ |
410e27a4 | 184 | static inline void ccid3_hc_tx_update_s(struct ccid3_hc_tx_sock *hctx, int len) |
78ad713d | 185 | { |
410e27a4 GR |
186 | const u16 old_s = hctx->ccid3hctx_s; |
187 | ||
188 | hctx->ccid3hctx_s = tfrc_ewma(hctx->ccid3hctx_s, len, 9); | |
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 | { |
410e27a4 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) { | |
410e27a4 GR |
205 | hctx->ccid3hctx_t_last_win_count = now; |
206 | hctx->ccid3hctx_last_win_count += min(quarter_rtts, 5U); | |
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 | ||
410e27a4 GR |
224 | ccid3_pr_debug("%s(%p, state=%s) - entry \n", dccp_role(sk), sk, |
225 | ccid3_tx_state_name(hctx->ccid3hctx_state)); | |
a9672411 | 226 | |
410e27a4 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) | |
d0995e6a GR |
230 | goto out; |
231 | ||
52515e77 GR |
232 | /* |
233 | * Determine new allowed sending rate X as per draft rfc3448bis-00, 4.4 | |
234 | */ | |
410e27a4 GR |
235 | if (hctx->ccid3hctx_t_rto == 0 || /* no feedback received yet */ |
236 | hctx->ccid3hctx_p == 0) { | |
52515e77 GR |
237 | |
238 | /* halve send rate directly */ | |
410e27a4 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 | */ |
410e27a4 | 254 | BUG_ON(hctx->ccid3hctx_p && !hctx->ccid3hctx_x_calc); |
0c150efb | 255 | |
410e27a4 GR |
256 | if (hctx->ccid3hctx_x_calc > (hctx->ccid3hctx_x_recv >> 5)) |
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 { |
410e27a4 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 | 267 | ccid3_pr_debug("Reduced X to %llu/64 bytes/sec\n", |
410e27a4 | 268 | (unsigned long long)hctx->ccid3hctx_x); |
52515e77 GR |
269 | |
270 | /* | |
271 | * Set new timeout for the nofeedback timer. | |
272 | * See comments in packet_recv() regarding the value of t_RTO. | |
273 | */ | |
410e27a4 | 274 | if (unlikely(hctx->ccid3hctx_t_rto == 0)) /* no feedback yet */ |
52515e77 GR |
275 | t_nfb = TFRC_INITIAL_TIMEOUT; |
276 | else | |
410e27a4 | 277 | t_nfb = max(hctx->ccid3hctx_t_rto, 2 * hctx->ccid3hctx_t_ipi); |
7c657876 | 278 | |
48e03eee | 279 | restart_timer: |
410e27a4 | 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 | ||
410e27a4 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 | |
7da7f456 | 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 | |
410e27a4 GR |
308 | switch (hctx->ccid3hctx_state) { |
309 | case TFRC_SSTATE_NO_SENT: | |
310 | sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer, | |
311 | (jiffies + | |
c9eaf173 | 312 | usecs_to_jiffies(TFRC_INITIAL_TIMEOUT))); |
410e27a4 GR |
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 */ | |
410e27a4 GR |
317 | hctx->ccid3hctx_t_nom = now; |
318 | ||
319 | hctx->ccid3hctx_s = skb->len; | |
30833ffe | 320 | |
30833ffe GR |
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); | |
410e27a4 GR |
328 | hctx->ccid3hctx_rtt = dp->dccps_syn_rtt; |
329 | hctx->ccid3hctx_x = rfc3390_initial_rate(sk); | |
330 | hctx->ccid3hctx_t_ld = now; | |
30833ffe | 331 | } else { |
3294f202 GR |
332 | /* |
333 | * Sender does not have RTT sample: | |
334 | * - set fallback RTT (RFC 4340, 3.4) since a RTT value | |
335 | * is needed in several parts (e.g. window counter); | |
336 | * - set sending rate X_pps = 1pps as per RFC 3448, 4.2. | |
337 | */ | |
410e27a4 GR |
338 | hctx->ccid3hctx_rtt = DCCP_FALLBACK_RTT; |
339 | hctx->ccid3hctx_x = hctx->ccid3hctx_s; | |
340 | hctx->ccid3hctx_x <<= 6; | |
30833ffe GR |
341 | } |
342 | ccid3_update_send_interval(hctx); | |
343 | ||
410e27a4 GR |
344 | ccid3_hc_tx_set_state(sk, TFRC_SSTATE_NO_FBACK); |
345 | break; | |
346 | case TFRC_SSTATE_NO_FBACK: | |
347 | case TFRC_SSTATE_FBACK: | |
348 | delay = ktime_us_delta(hctx->ccid3hctx_t_nom, now); | |
8699be7d | 349 | ccid3_pr_debug("delay=%ld\n", (long)delay); |
91cf5a17 | 350 | /* |
8109b02b | 351 | * Scheduling of packet transmissions [RFC 3448, 4.6] |
91cf5a17 GR |
352 | * |
353 | * if (t_now > t_nom - delta) | |
354 | * // send the packet now | |
355 | * else | |
356 | * // send the packet in (t_nom - t_now) milliseconds. | |
357 | */ | |
410e27a4 GR |
358 | if (delay - (s64)hctx->ccid3hctx_delta >= 1000) |
359 | return (u32)delay / 1000L; | |
9f8681db | 360 | |
8132da4d | 361 | ccid3_hc_tx_update_win_count(hctx, now); |
410e27a4 GR |
362 | break; |
363 | case TFRC_SSTATE_TERM: | |
364 | DCCP_BUG("%s(%p) - Illegal state TERM", dccp_role(sk), sk); | |
365 | return -EINVAL; | |
7c657876 ACM |
366 | } |
367 | ||
7da7f456 GR |
368 | /* prepare to send now (add options etc.) */ |
369 | dp->dccps_hc_tx_insert_options = 1; | |
410e27a4 | 370 | DCCP_SKB_CB(skb)->dccpd_ccval = hctx->ccid3hctx_last_win_count; |
e312d100 GR |
371 | |
372 | /* set the nominal send time for the next following packet */ | |
410e27a4 GR |
373 | hctx->ccid3hctx_t_nom = ktime_add_us(hctx->ccid3hctx_t_nom, |
374 | hctx->ccid3hctx_t_ipi); | |
375 | return 0; | |
7c657876 ACM |
376 | } |
377 | ||
410e27a4 GR |
378 | static void ccid3_hc_tx_packet_sent(struct sock *sk, int more, |
379 | unsigned int len) | |
7c657876 | 380 | { |
59725dc2 | 381 | struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); |
7c657876 | 382 | |
410e27a4 | 383 | ccid3_hc_tx_update_s(hctx, len); |
7c657876 | 384 | |
410e27a4 | 385 | if (tfrc_tx_hist_add(&hctx->ccid3hctx_hist, dccp_sk(sk)->dccps_gss)) |
c5a1ae9a | 386 | DCCP_CRIT("packet history - out of memory!"); |
7c657876 ACM |
387 | } |
388 | ||
389 | static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) | |
390 | { | |
59725dc2 | 391 | struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); |
410e27a4 | 392 | struct ccid3_options_received *opt_recv; |
0740d49c | 393 | ktime_t now; |
2a1fda6f | 394 | unsigned long t_nfb; |
410e27a4 | 395 | u32 pinv, r_sample; |
1f2333ae | 396 | |
7c657876 ACM |
397 | /* we are only interested in ACKs */ |
398 | if (!(DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_ACK || | |
399 | DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_DATAACK)) | |
400 | return; | |
410e27a4 GR |
401 | /* ... and only in the established state */ |
402 | if (hctx->ccid3hctx_state != TFRC_SSTATE_FBACK && | |
403 | hctx->ccid3hctx_state != TFRC_SSTATE_NO_FBACK) | |
404 | return; | |
405 | ||
406 | opt_recv = &hctx->ccid3hctx_options_received; | |
407 | now = ktime_get_real(); | |
408 | ||
409 | /* Estimate RTT from history if ACK number is valid */ | |
410 | r_sample = tfrc_tx_hist_rtt(hctx->ccid3hctx_hist, | |
411 | DCCP_SKB_CB(skb)->dccpd_ack_seq, now); | |
412 | if (r_sample == 0) { | |
413 | DCCP_WARN("%s(%p): %s with bogus ACK-%llu\n", dccp_role(sk), sk, | |
414 | dccp_packet_name(DCCP_SKB_CB(skb)->dccpd_type), | |
415 | (unsigned long long)DCCP_SKB_CB(skb)->dccpd_ack_seq); | |
5bd370a6 | 416 | return; |
410e27a4 | 417 | } |
63b3a73b | 418 | |
410e27a4 GR |
419 | /* Update receive rate in units of 64 * bytes/second */ |
420 | hctx->ccid3hctx_x_recv = opt_recv->ccid3or_receive_rate; | |
421 | hctx->ccid3hctx_x_recv <<= 6; | |
7c657876 | 422 | |
410e27a4 GR |
423 | /* Update loss event rate (which is scaled by 1e6) */ |
424 | pinv = opt_recv->ccid3or_loss_event_rate; | |
425 | if (pinv == ~0U || pinv == 0) /* see RFC 4342, 8.5 */ | |
426 | hctx->ccid3hctx_p = 0; | |
427 | else /* can not exceed 100% */ | |
428 | hctx->ccid3hctx_p = scaled_div(1, pinv); | |
429 | /* | |
430 | * Validate new RTT sample and update moving average | |
431 | */ | |
432 | r_sample = dccp_sample_rtt(sk, r_sample); | |
433 | hctx->ccid3hctx_rtt = tfrc_ewma(hctx->ccid3hctx_rtt, r_sample, 9); | |
d8d1252f GR |
434 | /* |
435 | * Update allowed sending rate X as per draft rfc3448bis-00, 4.2/3 | |
436 | */ | |
410e27a4 GR |
437 | if (hctx->ccid3hctx_state == TFRC_SSTATE_NO_FBACK) { |
438 | ccid3_hc_tx_set_state(sk, TFRC_SSTATE_FBACK); | |
5c3fbb6a | 439 | |
410e27a4 | 440 | if (hctx->ccid3hctx_t_rto == 0) { |
d8d1252f GR |
441 | /* |
442 | * Initial feedback packet: Larger Initial Windows (4.2) | |
443 | */ | |
410e27a4 GR |
444 | hctx->ccid3hctx_x = rfc3390_initial_rate(sk); |
445 | hctx->ccid3hctx_t_ld = now; | |
a79ef76f | 446 | |
d8d1252f | 447 | ccid3_update_send_interval(hctx); |
7c657876 | 448 | |
d8d1252f | 449 | goto done_computing_x; |
410e27a4 | 450 | } else if (hctx->ccid3hctx_p == 0) { |
d8d1252f GR |
451 | /* |
452 | * First feedback after nofeedback timer expiry (4.3) | |
453 | */ | |
454 | goto done_computing_x; | |
455 | } | |
456 | } | |
7c657876 | 457 | |
d8d1252f | 458 | /* Update sending rate (step 4 of [RFC 3448, 4.3]) */ |
410e27a4 GR |
459 | if (hctx->ccid3hctx_p > 0) |
460 | hctx->ccid3hctx_x_calc = | |
461 | tfrc_calc_x(hctx->ccid3hctx_s, | |
462 | hctx->ccid3hctx_rtt, | |
463 | hctx->ccid3hctx_p); | |
d8d1252f | 464 | ccid3_hc_tx_update_x(sk, &now); |
7c657876 | 465 | |
d8d1252f GR |
466 | done_computing_x: |
467 | ccid3_pr_debug("%s(%p), RTT=%uus (sample=%uus), s=%u, " | |
5bd370a6 | 468 | "p=%u, X_calc=%u, X_recv=%u, X=%u\n", |
410e27a4 GR |
469 | dccp_role(sk), |
470 | sk, hctx->ccid3hctx_rtt, r_sample, | |
471 | hctx->ccid3hctx_s, hctx->ccid3hctx_p, | |
472 | hctx->ccid3hctx_x_calc, | |
473 | (unsigned)(hctx->ccid3hctx_x_recv >> 6), | |
474 | (unsigned)(hctx->ccid3hctx_x >> 6)); | |
7c657876 | 475 | |
5bd370a6 | 476 | /* unschedule no feedback timer */ |
410e27a4 | 477 | sk_stop_timer(sk, &hctx->ccid3hctx_no_feedback_timer); |
7c657876 | 478 | |
5bd370a6 GR |
479 | /* |
480 | * As we have calculated new ipi, delta, t_nom it is possible | |
481 | * that we now can send a packet, so wake up dccp_wait_for_ccid | |
482 | */ | |
483 | sk->sk_write_space(sk); | |
8c60f3fa | 484 | |
5bd370a6 GR |
485 | /* |
486 | * Update timeout interval for the nofeedback timer. | |
487 | * We use a configuration option to increase the lower bound. | |
488 | * This can help avoid triggering the nofeedback timer too | |
489 | * often ('spinning') on LANs with small RTTs. | |
490 | */ | |
410e27a4 GR |
491 | hctx->ccid3hctx_t_rto = max_t(u32, 4 * hctx->ccid3hctx_rtt, |
492 | (CONFIG_IP_DCCP_CCID3_RTO * | |
493 | (USEC_PER_SEC / 1000))); | |
5bd370a6 GR |
494 | /* |
495 | * Schedule no feedback timer to expire in | |
496 | * max(t_RTO, 2 * s/X) = max(t_RTO, 2 * t_ipi) | |
497 | */ | |
410e27a4 | 498 | t_nfb = max(hctx->ccid3hctx_t_rto, 2 * hctx->ccid3hctx_t_ipi); |
7c657876 | 499 | |
5bd370a6 GR |
500 | ccid3_pr_debug("%s(%p), Scheduled no feedback timer to " |
501 | "expire in %lu jiffies (%luus)\n", | |
410e27a4 GR |
502 | dccp_role(sk), |
503 | sk, usecs_to_jiffies(t_nfb), t_nfb); | |
a9672411 | 504 | |
410e27a4 | 505 | sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer, |
5bd370a6 | 506 | jiffies + usecs_to_jiffies(t_nfb)); |
7c657876 ACM |
507 | } |
508 | ||
410e27a4 GR |
509 | static int ccid3_hc_tx_parse_options(struct sock *sk, unsigned char option, |
510 | unsigned char len, u16 idx, | |
511 | unsigned char *value) | |
7c657876 | 512 | { |
410e27a4 GR |
513 | int rc = 0; |
514 | const struct dccp_sock *dp = dccp_sk(sk); | |
59725dc2 | 515 | struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); |
410e27a4 | 516 | struct ccid3_options_received *opt_recv; |
76fd1e87 | 517 | __be32 opt_val; |
7c657876 | 518 | |
410e27a4 | 519 | opt_recv = &hctx->ccid3hctx_options_received; |
47a61e7b | 520 | |
410e27a4 GR |
521 | if (opt_recv->ccid3or_seqno != dp->dccps_gsr) { |
522 | opt_recv->ccid3or_seqno = dp->dccps_gsr; | |
523 | opt_recv->ccid3or_loss_event_rate = ~0; | |
524 | opt_recv->ccid3or_loss_intervals_idx = 0; | |
525 | opt_recv->ccid3or_loss_intervals_len = 0; | |
526 | opt_recv->ccid3or_receive_rate = 0; | |
527 | } | |
ce177ae2 | 528 | |
410e27a4 GR |
529 | switch (option) { |
530 | case TFRC_OPT_LOSS_EVENT_RATE: | |
531 | if (unlikely(len != 4)) { | |
532 | DCCP_WARN("%s(%p), invalid len %d " | |
533 | "for TFRC_OPT_LOSS_EVENT_RATE\n", | |
534 | dccp_role(sk), sk, len); | |
535 | rc = -EINVAL; | |
47a61e7b | 536 | } else { |
410e27a4 GR |
537 | opt_val = get_unaligned((__be32 *)value); |
538 | opt_recv->ccid3or_loss_event_rate = ntohl(opt_val); | |
47a61e7b | 539 | ccid3_pr_debug("%s(%p), LOSS_EVENT_RATE=%u\n", |
410e27a4 GR |
540 | dccp_role(sk), sk, |
541 | opt_recv->ccid3or_loss_event_rate); | |
7c657876 | 542 | } |
410e27a4 GR |
543 | break; |
544 | case TFRC_OPT_LOSS_INTERVALS: | |
545 | opt_recv->ccid3or_loss_intervals_idx = idx; | |
546 | opt_recv->ccid3or_loss_intervals_len = len; | |
547 | ccid3_pr_debug("%s(%p), LOSS_INTERVALS=(%u, %u)\n", | |
548 | dccp_role(sk), sk, | |
549 | opt_recv->ccid3or_loss_intervals_idx, | |
550 | opt_recv->ccid3or_loss_intervals_len); | |
551 | break; | |
552 | case TFRC_OPT_RECEIVE_RATE: | |
553 | if (unlikely(len != 4)) { | |
554 | DCCP_WARN("%s(%p), invalid len %d " | |
555 | "for TFRC_OPT_RECEIVE_RATE\n", | |
556 | dccp_role(sk), sk, len); | |
557 | rc = -EINVAL; | |
558 | } else { | |
559 | opt_val = get_unaligned((__be32 *)value); | |
560 | opt_recv->ccid3or_receive_rate = ntohl(opt_val); | |
561 | ccid3_pr_debug("%s(%p), RECEIVE_RATE=%u\n", | |
562 | dccp_role(sk), sk, | |
563 | opt_recv->ccid3or_receive_rate); | |
564 | } | |
565 | break; | |
7c657876 | 566 | } |
410e27a4 GR |
567 | |
568 | return rc; | |
7c657876 ACM |
569 | } |
570 | ||
91f0ebf7 | 571 | static int ccid3_hc_tx_init(struct ccid *ccid, struct sock *sk) |
7c657876 | 572 | { |
91f0ebf7 | 573 | struct ccid3_hc_tx_sock *hctx = ccid_priv(ccid); |
7c657876 | 574 | |
410e27a4 GR |
575 | hctx->ccid3hctx_state = TFRC_SSTATE_NO_SENT; |
576 | hctx->ccid3hctx_hist = NULL; | |
577 | setup_timer(&hctx->ccid3hctx_no_feedback_timer, | |
578 | ccid3_hc_tx_no_feedback_timer, (unsigned long)sk); | |
579 | ||
7c657876 ACM |
580 | return 0; |
581 | } | |
582 | ||
583 | static void ccid3_hc_tx_exit(struct sock *sk) | |
584 | { | |
59725dc2 | 585 | struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); |
7c657876 | 586 | |
410e27a4 GR |
587 | ccid3_hc_tx_set_state(sk, TFRC_SSTATE_TERM); |
588 | sk_stop_timer(sk, &hctx->ccid3hctx_no_feedback_timer); | |
589 | ||
590 | tfrc_tx_hist_purge(&hctx->ccid3hctx_hist); | |
7c657876 ACM |
591 | } |
592 | ||
9bf17475 GR |
593 | static void ccid3_hc_tx_get_info(struct sock *sk, struct tcp_info *info) |
594 | { | |
410e27a4 GR |
595 | struct ccid3_hc_tx_sock *hctx; |
596 | ||
597 | /* Listen socks doesn't have a private CCID block */ | |
598 | if (sk->sk_state == DCCP_LISTEN) | |
599 | return; | |
600 | ||
601 | hctx = ccid3_hc_tx_sk(sk); | |
602 | info->tcpi_rto = hctx->ccid3hctx_t_rto; | |
603 | info->tcpi_rtt = hctx->ccid3hctx_rtt; | |
9bf17475 GR |
604 | } |
605 | ||
606 | static int ccid3_hc_tx_getsockopt(struct sock *sk, const int optname, int len, | |
607 | u32 __user *optval, int __user *optlen) | |
608 | { | |
410e27a4 | 609 | const struct ccid3_hc_tx_sock *hctx; |
9bf17475 GR |
610 | const void *val; |
611 | ||
410e27a4 GR |
612 | /* Listen socks doesn't have a private CCID block */ |
613 | if (sk->sk_state == DCCP_LISTEN) | |
614 | return -EINVAL; | |
615 | ||
616 | hctx = ccid3_hc_tx_sk(sk); | |
9bf17475 GR |
617 | switch (optname) { |
618 | case DCCP_SOCKOPT_CCID_TX_INFO: | |
410e27a4 | 619 | if (len < sizeof(hctx->ccid3hctx_tfrc)) |
9bf17475 | 620 | return -EINVAL; |
410e27a4 GR |
621 | len = sizeof(hctx->ccid3hctx_tfrc); |
622 | val = &hctx->ccid3hctx_tfrc; | |
9bf17475 GR |
623 | break; |
624 | default: | |
625 | return -ENOPROTOOPT; | |
626 | } | |
627 | ||
628 | if (put_user(len, optlen) || copy_to_user(optval, val, len)) | |
629 | return -EFAULT; | |
630 | ||
631 | return 0; | |
632 | } | |
633 | ||
7c657876 | 634 | /* |
9bf17475 | 635 | * Receiver Half-Connection Routines |
7c657876 | 636 | */ |
410e27a4 GR |
637 | |
638 | /* CCID3 feedback types */ | |
639 | enum ccid3_fback_type { | |
640 | CCID3_FBACK_NONE = 0, | |
641 | CCID3_FBACK_INITIAL, | |
642 | CCID3_FBACK_PERIODIC, | |
643 | CCID3_FBACK_PARAM_CHANGE | |
644 | }; | |
645 | ||
646 | #ifdef CONFIG_IP_DCCP_CCID3_DEBUG | |
647 | static const char *ccid3_rx_state_name(enum ccid3_hc_rx_states state) | |
648 | { | |
36cbd3dc | 649 | static const char *const ccid3_rx_state_names[] = { |
410e27a4 GR |
650 | [TFRC_RSTATE_NO_DATA] = "NO_DATA", |
651 | [TFRC_RSTATE_DATA] = "DATA", | |
652 | [TFRC_RSTATE_TERM] = "TERM", | |
653 | }; | |
654 | ||
655 | return ccid3_rx_state_names[state]; | |
656 | } | |
657 | #endif | |
658 | ||
659 | static void ccid3_hc_rx_set_state(struct sock *sk, | |
660 | enum ccid3_hc_rx_states state) | |
661 | { | |
662 | struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk); | |
663 | enum ccid3_hc_rx_states oldstate = hcrx->ccid3hcrx_state; | |
664 | ||
665 | ccid3_pr_debug("%s(%p) %-8.8s -> %s\n", | |
666 | dccp_role(sk), sk, ccid3_rx_state_name(oldstate), | |
667 | ccid3_rx_state_name(state)); | |
668 | WARN_ON(state == oldstate); | |
669 | hcrx->ccid3hcrx_state = state; | |
670 | } | |
671 | ||
b84a2189 ACM |
672 | static void ccid3_hc_rx_send_feedback(struct sock *sk, |
673 | const struct sk_buff *skb, | |
674 | enum ccid3_fback_type fbtype) | |
7c657876 | 675 | { |
59725dc2 | 676 | struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk); |
410e27a4 GR |
677 | struct dccp_sock *dp = dccp_sk(sk); |
678 | ktime_t now; | |
679 | s64 delta = 0; | |
680 | ||
681 | if (unlikely(hcrx->ccid3hcrx_state == TFRC_RSTATE_TERM)) | |
682 | return; | |
683 | ||
684 | now = ktime_get_real(); | |
7c657876 | 685 | |
b84a2189 ACM |
686 | switch (fbtype) { |
687 | case CCID3_FBACK_INITIAL: | |
410e27a4 GR |
688 | hcrx->ccid3hcrx_x_recv = 0; |
689 | hcrx->ccid3hcrx_pinv = ~0U; /* see RFC 4342, 8.5 */ | |
7c657876 | 690 | break; |
b84a2189 ACM |
691 | case CCID3_FBACK_PARAM_CHANGE: |
692 | /* | |
693 | * When parameters change (new loss or p > p_prev), we do not | |
694 | * have a reliable estimate for R_m of [RFC 3448, 6.2] and so | |
410e27a4 GR |
695 | * need to reuse the previous value of X_recv. However, when |
696 | * X_recv was 0 (due to early loss), this would kill X down to | |
697 | * s/t_mbi (i.e. one packet in 64 seconds). | |
698 | * To avoid such drastic reduction, we approximate X_recv as | |
699 | * the number of bytes since last feedback. | |
700 | * This is a safe fallback, since X is bounded above by X_calc. | |
b84a2189 | 701 | */ |
410e27a4 GR |
702 | if (hcrx->ccid3hcrx_x_recv > 0) |
703 | break; | |
704 | /* fall through */ | |
b84a2189 | 705 | case CCID3_FBACK_PERIODIC: |
410e27a4 GR |
706 | delta = ktime_us_delta(now, hcrx->ccid3hcrx_tstamp_last_feedback); |
707 | if (delta <= 0) | |
708 | DCCP_BUG("delta (%ld) <= 0", (long)delta); | |
709 | else | |
710 | hcrx->ccid3hcrx_x_recv = | |
711 | scaled_div32(hcrx->ccid3hcrx_bytes_recv, delta); | |
7c657876 | 712 | break; |
b84a2189 | 713 | default: |
7c657876 ACM |
714 | return; |
715 | } | |
716 | ||
410e27a4 GR |
717 | ccid3_pr_debug("Interval %ldusec, X_recv=%u, 1/p=%u\n", (long)delta, |
718 | hcrx->ccid3hcrx_x_recv, hcrx->ccid3hcrx_pinv); | |
7c657876 | 719 | |
410e27a4 GR |
720 | hcrx->ccid3hcrx_tstamp_last_feedback = now; |
721 | hcrx->ccid3hcrx_last_counter = dccp_hdr(skb)->dccph_ccval; | |
722 | hcrx->ccid3hcrx_bytes_recv = 0; | |
68c89ee5 | 723 | |
410e27a4 GR |
724 | dp->dccps_hc_rx_insert_options = 1; |
725 | dccp_send_ack(sk); | |
7c657876 ACM |
726 | } |
727 | ||
2d0817d1 | 728 | static int ccid3_hc_rx_insert_options(struct sock *sk, struct sk_buff *skb) |
7c657876 | 729 | { |
410e27a4 | 730 | const struct ccid3_hc_rx_sock *hcrx; |
60fe62e7 | 731 | __be32 x_recv, pinv; |
7c657876 | 732 | |
59d203f9 | 733 | if (!(sk->sk_state == DCCP_OPEN || sk->sk_state == DCCP_PARTOPEN)) |
2d0817d1 | 734 | return 0; |
7c657876 | 735 | |
410e27a4 GR |
736 | hcrx = ccid3_hc_rx_sk(sk); |
737 | ||
4fded33b | 738 | if (dccp_packet_without_ack(skb)) |
2d0817d1 ACM |
739 | return 0; |
740 | ||
410e27a4 GR |
741 | x_recv = htonl(hcrx->ccid3hcrx_x_recv); |
742 | pinv = htonl(hcrx->ccid3hcrx_pinv); | |
2d0817d1 | 743 | |
385ac2e3 | 744 | if (dccp_insert_option(sk, skb, TFRC_OPT_LOSS_EVENT_RATE, |
8109b02b | 745 | &pinv, sizeof(pinv)) || |
2d0817d1 | 746 | dccp_insert_option(sk, skb, TFRC_OPT_RECEIVE_RATE, |
8109b02b | 747 | &x_recv, sizeof(x_recv))) |
2d0817d1 ACM |
748 | return -1; |
749 | ||
750 | return 0; | |
7c657876 ACM |
751 | } |
752 | ||
954c2db8 GR |
753 | /** ccid3_first_li - Implements [RFC 3448, 6.3.1] |
754 | * | |
755 | * Determine the length of the first loss interval via inverse lookup. | |
756 | * Assume that X_recv can be computed by the throughput equation | |
757 | * s | |
758 | * X_recv = -------- | |
759 | * R * fval | |
760 | * Find some p such that f(p) = fval; return 1/p (scaled). | |
761 | */ | |
762 | static u32 ccid3_first_li(struct sock *sk) | |
763 | { | |
764 | struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk); | |
410e27a4 | 765 | u32 x_recv, p, delta; |
954c2db8 GR |
766 | u64 fval; |
767 | ||
410e27a4 GR |
768 | if (hcrx->ccid3hcrx_rtt == 0) { |
769 | DCCP_WARN("No RTT estimate available, using fallback RTT\n"); | |
770 | hcrx->ccid3hcrx_rtt = DCCP_FALLBACK_RTT; | |
771 | } | |
d20ed95f | 772 | |
410e27a4 GR |
773 | delta = ktime_to_us(net_timedelta(hcrx->ccid3hcrx_tstamp_last_feedback)); |
774 | x_recv = scaled_div32(hcrx->ccid3hcrx_bytes_recv, delta); | |
775 | if (x_recv == 0) { /* would also trigger divide-by-zero */ | |
776 | DCCP_WARN("X_recv==0\n"); | |
777 | if ((x_recv = hcrx->ccid3hcrx_x_recv) == 0) { | |
778 | DCCP_BUG("stored value of X_recv is zero"); | |
779 | return ~0U; | |
780 | } | |
781 | } | |
954c2db8 | 782 | |
410e27a4 GR |
783 | fval = scaled_div(hcrx->ccid3hcrx_s, hcrx->ccid3hcrx_rtt); |
784 | fval = scaled_div32(fval, x_recv); | |
954c2db8 GR |
785 | p = tfrc_calc_x_reverse_lookup(fval); |
786 | ||
787 | ccid3_pr_debug("%s(%p), receive rate=%u bytes/s, implied " | |
788 | "loss rate=%u\n", dccp_role(sk), sk, x_recv, p); | |
789 | ||
410e27a4 | 790 | return p == 0 ? ~0U : scaled_div(1, p); |
954c2db8 GR |
791 | } |
792 | ||
b84a2189 | 793 | static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb) |
7c657876 | 794 | { |
59725dc2 | 795 | struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk); |
410e27a4 | 796 | enum ccid3_fback_type do_feedback = CCID3_FBACK_NONE; |
5b5d0e70 | 797 | const u64 ndp = dccp_sk(sk)->dccps_options_received.dccpor_ndp; |
b84a2189 ACM |
798 | const bool is_data_packet = dccp_data_packet(skb); |
799 | ||
410e27a4 GR |
800 | if (unlikely(hcrx->ccid3hcrx_state == TFRC_RSTATE_NO_DATA)) { |
801 | if (is_data_packet) { | |
802 | const u32 payload = skb->len - dccp_hdr(skb)->dccph_doff * 4; | |
803 | do_feedback = CCID3_FBACK_INITIAL; | |
804 | ccid3_hc_rx_set_state(sk, TFRC_RSTATE_DATA); | |
805 | hcrx->ccid3hcrx_s = payload; | |
806 | /* | |
807 | * Not necessary to update ccid3hcrx_bytes_recv here, | |
808 | * since X_recv = 0 for the first feedback packet (cf. | |
809 | * RFC 3448, 6.3) -- gerrit | |
810 | */ | |
811 | } | |
812 | goto update_records; | |
813 | } | |
814 | ||
815 | if (tfrc_rx_hist_duplicate(&hcrx->ccid3hcrx_hist, skb)) | |
816 | return; /* done receiving */ | |
817 | ||
818 | if (is_data_packet) { | |
819 | const u32 payload = skb->len - dccp_hdr(skb)->dccph_doff * 4; | |
820 | /* | |
821 | * Update moving-average of s and the sum of received payload bytes | |
822 | */ | |
823 | hcrx->ccid3hcrx_s = tfrc_ewma(hcrx->ccid3hcrx_s, payload, 9); | |
824 | hcrx->ccid3hcrx_bytes_recv += payload; | |
825 | } | |
826 | ||
d20ed95f GR |
827 | /* |
828 | * Perform loss detection and handle pending losses | |
829 | */ | |
410e27a4 GR |
830 | if (tfrc_rx_handle_loss(&hcrx->ccid3hcrx_hist, &hcrx->ccid3hcrx_li_hist, |
831 | skb, ndp, ccid3_first_li, sk)) { | |
832 | do_feedback = CCID3_FBACK_PARAM_CHANGE; | |
833 | goto done_receiving; | |
834 | } | |
835 | ||
836 | if (tfrc_rx_hist_loss_pending(&hcrx->ccid3hcrx_hist)) | |
837 | return; /* done receiving */ | |
838 | ||
88e97a93 | 839 | /* |
410e27a4 | 840 | * Handle data packets: RTT sampling and monitoring p |
88e97a93 | 841 | */ |
410e27a4 GR |
842 | if (unlikely(!is_data_packet)) |
843 | goto update_records; | |
844 | ||
845 | if (!tfrc_lh_is_initialised(&hcrx->ccid3hcrx_li_hist)) { | |
846 | const u32 sample = tfrc_rx_hist_sample_rtt(&hcrx->ccid3hcrx_hist, skb); | |
847 | /* | |
848 | * Empty loss history: no loss so far, hence p stays 0. | |
849 | * Sample RTT values, since an RTT estimate is required for the | |
850 | * computation of p when the first loss occurs; RFC 3448, 6.3.1. | |
851 | */ | |
852 | if (sample != 0) | |
853 | hcrx->ccid3hcrx_rtt = tfrc_ewma(hcrx->ccid3hcrx_rtt, sample, 9); | |
854 | ||
855 | } else if (tfrc_lh_update_i_mean(&hcrx->ccid3hcrx_li_hist, skb)) { | |
856 | /* | |
857 | * Step (3) of [RFC 3448, 6.1]: Recompute I_mean and, if I_mean | |
858 | * has decreased (resp. p has increased), send feedback now. | |
859 | */ | |
860 | do_feedback = CCID3_FBACK_PARAM_CHANGE; | |
861 | } | |
862 | ||
b84a2189 ACM |
863 | /* |
864 | * Check if the periodic once-per-RTT feedback is due; RFC 4342, 10.3 | |
865 | */ | |
410e27a4 GR |
866 | if (SUB16(dccp_hdr(skb)->dccph_ccval, hcrx->ccid3hcrx_last_counter) > 3) |
867 | do_feedback = CCID3_FBACK_PERIODIC; | |
868 | ||
869 | update_records: | |
870 | tfrc_rx_hist_add_packet(&hcrx->ccid3hcrx_hist, skb, ndp); | |
871 | ||
872 | done_receiving: | |
873 | if (do_feedback) | |
874 | ccid3_hc_rx_send_feedback(sk, skb, do_feedback); | |
7c657876 ACM |
875 | } |
876 | ||
91f0ebf7 | 877 | static int ccid3_hc_rx_init(struct ccid *ccid, struct sock *sk) |
7c657876 | 878 | { |
91f0ebf7 | 879 | struct ccid3_hc_rx_sock *hcrx = ccid_priv(ccid); |
7c657876 | 880 | |
410e27a4 GR |
881 | hcrx->ccid3hcrx_state = TFRC_RSTATE_NO_DATA; |
882 | tfrc_lh_init(&hcrx->ccid3hcrx_li_hist); | |
883 | return tfrc_rx_hist_alloc(&hcrx->ccid3hcrx_hist); | |
7c657876 ACM |
884 | } |
885 | ||
886 | static void ccid3_hc_rx_exit(struct sock *sk) | |
887 | { | |
59725dc2 | 888 | struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk); |
7c657876 | 889 | |
410e27a4 GR |
890 | ccid3_hc_rx_set_state(sk, TFRC_RSTATE_TERM); |
891 | ||
892 | tfrc_rx_hist_purge(&hcrx->ccid3hcrx_hist); | |
893 | tfrc_lh_cleanup(&hcrx->ccid3hcrx_li_hist); | |
7c657876 ACM |
894 | } |
895 | ||
2babe1f6 ACM |
896 | static void ccid3_hc_rx_get_info(struct sock *sk, struct tcp_info *info) |
897 | { | |
410e27a4 GR |
898 | const struct ccid3_hc_rx_sock *hcrx; |
899 | ||
900 | /* Listen socks doesn't have a private CCID block */ | |
901 | if (sk->sk_state == DCCP_LISTEN) | |
902 | return; | |
903 | ||
904 | hcrx = ccid3_hc_rx_sk(sk); | |
905 | info->tcpi_ca_state = hcrx->ccid3hcrx_state; | |
8109b02b | 906 | info->tcpi_options |= TCPI_OPT_TIMESTAMPS; |
410e27a4 | 907 | info->tcpi_rcv_rtt = hcrx->ccid3hcrx_rtt; |
2babe1f6 ACM |
908 | } |
909 | ||
88f964db ACM |
910 | static int ccid3_hc_rx_getsockopt(struct sock *sk, const int optname, int len, |
911 | u32 __user *optval, int __user *optlen) | |
912 | { | |
410e27a4 | 913 | const struct ccid3_hc_rx_sock *hcrx; |
8e138e79 | 914 | struct tfrc_rx_info rx_info; |
88f964db | 915 | const void *val; |
c9eaf173 | 916 | |
410e27a4 GR |
917 | /* Listen socks doesn't have a private CCID block */ |
918 | if (sk->sk_state == DCCP_LISTEN) | |
919 | return -EINVAL; | |
920 | ||
921 | hcrx = ccid3_hc_rx_sk(sk); | |
88f964db ACM |
922 | switch (optname) { |
923 | case DCCP_SOCKOPT_CCID_RX_INFO: | |
8e138e79 | 924 | if (len < sizeof(rx_info)) |
88f964db | 925 | return -EINVAL; |
410e27a4 GR |
926 | rx_info.tfrcrx_x_recv = hcrx->ccid3hcrx_x_recv; |
927 | rx_info.tfrcrx_rtt = hcrx->ccid3hcrx_rtt; | |
928 | rx_info.tfrcrx_p = hcrx->ccid3hcrx_pinv == 0 ? ~0U : | |
929 | scaled_div(1, hcrx->ccid3hcrx_pinv); | |
8e138e79 GR |
930 | len = sizeof(rx_info); |
931 | val = &rx_info; | |
88f964db ACM |
932 | break; |
933 | default: | |
934 | return -ENOPROTOOPT; | |
935 | } | |
936 | ||
937 | if (put_user(len, optlen) || copy_to_user(optval, val, len)) | |
938 | return -EFAULT; | |
939 | ||
940 | return 0; | |
941 | } | |
942 | ||
ddebc973 | 943 | struct ccid_operations ccid3_ops = { |
3dd9a7c3 | 944 | .ccid_id = DCCPC_CCID3, |
84a97b0a | 945 | .ccid_name = "TCP-Friendly Rate Control", |
91f0ebf7 | 946 | .ccid_hc_tx_obj_size = sizeof(struct ccid3_hc_tx_sock), |
7c657876 ACM |
947 | .ccid_hc_tx_init = ccid3_hc_tx_init, |
948 | .ccid_hc_tx_exit = ccid3_hc_tx_exit, | |
949 | .ccid_hc_tx_send_packet = ccid3_hc_tx_send_packet, | |
950 | .ccid_hc_tx_packet_sent = ccid3_hc_tx_packet_sent, | |
951 | .ccid_hc_tx_packet_recv = ccid3_hc_tx_packet_recv, | |
7c657876 | 952 | .ccid_hc_tx_parse_options = ccid3_hc_tx_parse_options, |
91f0ebf7 | 953 | .ccid_hc_rx_obj_size = sizeof(struct ccid3_hc_rx_sock), |
7c657876 ACM |
954 | .ccid_hc_rx_init = ccid3_hc_rx_init, |
955 | .ccid_hc_rx_exit = ccid3_hc_rx_exit, | |
956 | .ccid_hc_rx_insert_options = ccid3_hc_rx_insert_options, | |
957 | .ccid_hc_rx_packet_recv = ccid3_hc_rx_packet_recv, | |
2babe1f6 ACM |
958 | .ccid_hc_rx_get_info = ccid3_hc_rx_get_info, |
959 | .ccid_hc_tx_get_info = ccid3_hc_tx_get_info, | |
88f964db ACM |
960 | .ccid_hc_rx_getsockopt = ccid3_hc_rx_getsockopt, |
961 | .ccid_hc_tx_getsockopt = ccid3_hc_tx_getsockopt, | |
7c657876 | 962 | }; |
8109b02b | 963 | |
56724aa4 | 964 | #ifdef CONFIG_IP_DCCP_CCID3_DEBUG |
43264991 | 965 | module_param(ccid3_debug, bool, 0644); |
ddebc973 | 966 | MODULE_PARM_DESC(ccid3_debug, "Enable CCID-3 debug messages"); |
56724aa4 | 967 | #endif |