Commit | Line | Data |
---|---|---|
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); | |
68 | enum ccid3_hc_tx_states oldstate = hctx->ccid3hctx_state; | |
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); | |
74 | hctx->ccid3hctx_state = state; | |
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 GR |
88 | const struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); |
89 | const __u32 w_init = clamp_t(__u32, 4380U, | |
90 | 2 * hctx->ccid3hctx_s, 4 * hctx->ccid3hctx_s); | |
a21f9f96 | 91 | |
410e27a4 | 92 | return scaled_div(w_init << 6, hctx->ccid3hctx_rtt); |
a21f9f96 GR |
93 | } |
94 | ||
410e27a4 GR |
95 | /* |
96 | * Recalculate t_ipi and delta (should be called whenever X changes) | |
17893bc1 | 97 | */ |
c4e18dad | 98 | static void ccid3_update_send_interval(struct ccid3_hc_tx_sock *hctx) |
7c657876 | 99 | { |
410e27a4 GR |
100 | /* Calculate new t_ipi = s / X_inst (X_inst is in 64 * bytes/second) */ |
101 | hctx->ccid3hctx_t_ipi = scaled_div32(((u64)hctx->ccid3hctx_s) << 6, | |
102 | hctx->ccid3hctx_x); | |
103 | ||
104 | /* Calculate new delta by delta = min(t_ipi / 2, t_gran / 2) */ | |
105 | hctx->ccid3hctx_delta = min_t(u32, hctx->ccid3hctx_t_ipi / 2, | |
106 | TFRC_OPSYS_HALF_TIME_GRAN); | |
107 | ||
108 | ccid3_pr_debug("t_ipi=%u, delta=%u, s=%u, X=%u\n", | |
109 | hctx->ccid3hctx_t_ipi, hctx->ccid3hctx_delta, | |
110 | hctx->ccid3hctx_s, (unsigned)(hctx->ccid3hctx_x >> 6)); | |
111 | ||
7c657876 | 112 | } |
aa97efd9 | 113 | |
a5358fdc GR |
114 | static u32 ccid3_hc_tx_idle_rtt(struct ccid3_hc_tx_sock *hctx, ktime_t now) |
115 | { | |
410e27a4 | 116 | u32 delta = ktime_us_delta(now, hctx->ccid3hctx_t_last_win_count); |
a5358fdc | 117 | |
410e27a4 | 118 | return delta / hctx->ccid3hctx_rtt; |
a5358fdc GR |
119 | } |
120 | ||
aa97efd9 GR |
121 | /** |
122 | * ccid3_hc_tx_update_x - Update allowed sending rate X | |
123 | * @stamp: most recent time if available - can be left NULL. | |
124 | * This function tracks draft rfc3448bis, check there for latest details. | |
5c3fbb6a | 125 | * |
1a21e49a GR |
126 | * Note: X and X_recv are both stored in units of 64 * bytes/second, to support |
127 | * fine-grained resolution of sending rates. This requires scaling by 2^6 | |
128 | * throughout the code. Only X_calc is unscaled (in bytes/second). | |
129 | * | |
1a21e49a | 130 | */ |
aa97efd9 | 131 | static void ccid3_hc_tx_update_x(struct sock *sk, ktime_t *stamp) |
7c657876 | 132 | { |
59725dc2 | 133 | struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); |
410e27a4 GR |
134 | __u64 min_rate = 2 * hctx->ccid3hctx_x_recv; |
135 | const __u64 old_x = hctx->ccid3hctx_x; | |
52515e77 | 136 | ktime_t now = stamp ? *stamp : ktime_get_real(); |
7c657876 | 137 | |
0c150efb GR |
138 | /* |
139 | * Handle IDLE periods: do not reduce below RFC3390 initial sending rate | |
a5358fdc GR |
140 | * when idling [RFC 4342, 5.1]. Definition of idling is from rfc3448bis: |
141 | * a sender is idle if it has not sent anything over a 2-RTT-period. | |
0c150efb GR |
142 | * For consistency with X and X_recv, min_rate is also scaled by 2^6. |
143 | */ | |
a5358fdc | 144 | if (ccid3_hc_tx_idle_rtt(hctx, now) >= 2) { |
0c150efb | 145 | min_rate = rfc3390_initial_rate(sk); |
410e27a4 | 146 | min_rate = max(min_rate, 2 * hctx->ccid3hctx_x_recv); |
0c150efb GR |
147 | } |
148 | ||
410e27a4 | 149 | if (hctx->ccid3hctx_p > 0) { |
1a21e49a | 150 | |
410e27a4 GR |
151 | hctx->ccid3hctx_x = min(((__u64)hctx->ccid3hctx_x_calc) << 6, |
152 | min_rate); | |
153 | hctx->ccid3hctx_x = max(hctx->ccid3hctx_x, | |
154 | (((__u64)hctx->ccid3hctx_s) << 6) / | |
155 | TFRC_T_MBI); | |
a79ef76f | 156 | |
410e27a4 GR |
157 | } else if (ktime_us_delta(now, hctx->ccid3hctx_t_ld) |
158 | - (s64)hctx->ccid3hctx_rtt >= 0) { | |
ac198ea8 | 159 | |
410e27a4 GR |
160 | hctx->ccid3hctx_x = min(2 * hctx->ccid3hctx_x, min_rate); |
161 | hctx->ccid3hctx_x = max(hctx->ccid3hctx_x, | |
162 | scaled_div(((__u64)hctx->ccid3hctx_s) << 6, | |
163 | hctx->ccid3hctx_rtt)); | |
164 | hctx->ccid3hctx_t_ld = now; | |
ff586298 | 165 | } |
b6ee3d4a | 166 | |
410e27a4 | 167 | if (hctx->ccid3hctx_x != old_x) { |
1761f7d7 GR |
168 | ccid3_pr_debug("X_prev=%u, X_now=%u, X_calc=%u, " |
169 | "X_recv=%u\n", (unsigned)(old_x >> 6), | |
410e27a4 GR |
170 | (unsigned)(hctx->ccid3hctx_x >> 6), |
171 | hctx->ccid3hctx_x_calc, | |
172 | (unsigned)(hctx->ccid3hctx_x_recv >> 6)); | |
8699be7d | 173 | |
1266adee | 174 | ccid3_update_send_interval(hctx); |
8699be7d | 175 | } |
7c657876 ACM |
176 | } |
177 | ||
78ad713d | 178 | /* |
410e27a4 GR |
179 | * Track the mean packet size `s' (cf. RFC 4342, 5.3 and RFC 3448, 4.1) |
180 | * @len: DCCP packet payload size in bytes | |
78ad713d | 181 | */ |
410e27a4 | 182 | static inline void ccid3_hc_tx_update_s(struct ccid3_hc_tx_sock *hctx, int len) |
78ad713d | 183 | { |
410e27a4 GR |
184 | const u16 old_s = hctx->ccid3hctx_s; |
185 | ||
186 | hctx->ccid3hctx_s = tfrc_ewma(hctx->ccid3hctx_s, len, 9); | |
187 | ||
188 | if (hctx->ccid3hctx_s != old_s) | |
189 | ccid3_update_send_interval(hctx); | |
78ad713d GR |
190 | } |
191 | ||
9f8681db | 192 | /* |
8109b02b | 193 | * Update Window Counter using the algorithm from [RFC 4342, 8.1]. |
825de27d | 194 | * As elsewhere, RTT > 0 is assumed by using dccp_sample_rtt(). |
9f8681db GR |
195 | */ |
196 | static inline void ccid3_hc_tx_update_win_count(struct ccid3_hc_tx_sock *hctx, | |
8132da4d | 197 | ktime_t now) |
9f8681db | 198 | { |
410e27a4 GR |
199 | u32 delta = ktime_us_delta(now, hctx->ccid3hctx_t_last_win_count), |
200 | quarter_rtts = (4 * delta) / hctx->ccid3hctx_rtt; | |
9f8681db GR |
201 | |
202 | if (quarter_rtts > 0) { | |
410e27a4 GR |
203 | hctx->ccid3hctx_t_last_win_count = now; |
204 | hctx->ccid3hctx_last_win_count += min(quarter_rtts, 5U); | |
205 | hctx->ccid3hctx_last_win_count &= 0xF; /* mod 16 */ | |
9f8681db GR |
206 | } |
207 | } | |
208 | ||
7c657876 ACM |
209 | static void ccid3_hc_tx_no_feedback_timer(unsigned long data) |
210 | { | |
211 | struct sock *sk = (struct sock *)data; | |
59725dc2 | 212 | struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); |
2a1fda6f | 213 | unsigned long t_nfb = USEC_PER_SEC / 5; |
7c657876 ACM |
214 | |
215 | bh_lock_sock(sk); | |
216 | if (sock_owned_by_user(sk)) { | |
217 | /* Try again later. */ | |
218 | /* XXX: set some sensible MIB */ | |
48e03eee | 219 | goto restart_timer; |
7c657876 ACM |
220 | } |
221 | ||
410e27a4 GR |
222 | ccid3_pr_debug("%s(%p, state=%s) - entry \n", dccp_role(sk), sk, |
223 | ccid3_tx_state_name(hctx->ccid3hctx_state)); | |
a9672411 | 224 | |
410e27a4 GR |
225 | if (hctx->ccid3hctx_state == TFRC_SSTATE_FBACK) |
226 | ccid3_hc_tx_set_state(sk, TFRC_SSTATE_NO_FBACK); | |
227 | else if (hctx->ccid3hctx_state != TFRC_SSTATE_NO_FBACK) | |
d0995e6a GR |
228 | goto out; |
229 | ||
52515e77 GR |
230 | /* |
231 | * Determine new allowed sending rate X as per draft rfc3448bis-00, 4.4 | |
232 | */ | |
410e27a4 GR |
233 | if (hctx->ccid3hctx_t_rto == 0 || /* no feedback received yet */ |
234 | hctx->ccid3hctx_p == 0) { | |
52515e77 GR |
235 | |
236 | /* halve send rate directly */ | |
410e27a4 GR |
237 | hctx->ccid3hctx_x = max(hctx->ccid3hctx_x / 2, |
238 | (((__u64)hctx->ccid3hctx_s) << 6) / | |
239 | TFRC_T_MBI); | |
1266adee | 240 | ccid3_update_send_interval(hctx); |
52515e77 | 241 | } else { |
1f2333ae | 242 | /* |
52515e77 | 243 | * Modify the cached value of X_recv |
0c150efb | 244 | * |
52515e77 | 245 | * If (X_calc > 2 * X_recv) |
0c150efb GR |
246 | * X_recv = max(X_recv / 2, s / (2 * t_mbi)); |
247 | * Else | |
248 | * X_recv = X_calc / 4; | |
249 | * | |
250 | * Note that X_recv is scaled by 2^6 while X_calc is not | |
1f2333ae | 251 | */ |
410e27a4 | 252 | BUG_ON(hctx->ccid3hctx_p && !hctx->ccid3hctx_x_calc); |
0c150efb | 253 | |
410e27a4 GR |
254 | if (hctx->ccid3hctx_x_calc > (hctx->ccid3hctx_x_recv >> 5)) |
255 | hctx->ccid3hctx_x_recv = | |
256 | max(hctx->ccid3hctx_x_recv / 2, | |
257 | (((__u64)hctx->ccid3hctx_s) << 6) / | |
258 | (2 * TFRC_T_MBI)); | |
52515e77 | 259 | else { |
410e27a4 GR |
260 | hctx->ccid3hctx_x_recv = hctx->ccid3hctx_x_calc; |
261 | hctx->ccid3hctx_x_recv <<= 4; | |
7c657876 | 262 | } |
aa97efd9 | 263 | ccid3_hc_tx_update_x(sk, NULL); |
7c657876 | 264 | } |
52515e77 | 265 | ccid3_pr_debug("Reduced X to %llu/64 bytes/sec\n", |
410e27a4 | 266 | (unsigned long long)hctx->ccid3hctx_x); |
52515e77 GR |
267 | |
268 | /* | |
269 | * Set new timeout for the nofeedback timer. | |
270 | * See comments in packet_recv() regarding the value of t_RTO. | |
271 | */ | |
410e27a4 | 272 | if (unlikely(hctx->ccid3hctx_t_rto == 0)) /* no feedback yet */ |
52515e77 GR |
273 | t_nfb = TFRC_INITIAL_TIMEOUT; |
274 | else | |
410e27a4 | 275 | t_nfb = max(hctx->ccid3hctx_t_rto, 2 * hctx->ccid3hctx_t_ipi); |
7c657876 | 276 | |
48e03eee | 277 | restart_timer: |
410e27a4 | 278 | sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer, |
c9eaf173 | 279 | jiffies + usecs_to_jiffies(t_nfb)); |
7c657876 ACM |
280 | out: |
281 | bh_unlock_sock(sk); | |
282 | sock_put(sk); | |
283 | } | |
284 | ||
410e27a4 GR |
285 | /* |
286 | * returns | |
287 | * > 0: delay (in msecs) that should pass before actually sending | |
288 | * = 0: can send immediately | |
289 | * < 0: error condition; do not send packet | |
7da7f456 | 290 | */ |
6b57c93d | 291 | static int ccid3_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb) |
7c657876 ACM |
292 | { |
293 | struct dccp_sock *dp = dccp_sk(sk); | |
59725dc2 | 294 | struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); |
8132da4d GR |
295 | ktime_t now = ktime_get_real(); |
296 | s64 delay; | |
7c657876 | 297 | |
7c657876 | 298 | /* |
da335baf GR |
299 | * This function is called only for Data and DataAck packets. Sending |
300 | * zero-sized Data(Ack)s is theoretically possible, but for congestion | |
301 | * control this case is pathological - ignore it. | |
7c657876 | 302 | */ |
6b57c93d | 303 | if (unlikely(skb->len == 0)) |
da335baf | 304 | return -EBADMSG; |
7c657876 | 305 | |
410e27a4 GR |
306 | switch (hctx->ccid3hctx_state) { |
307 | case TFRC_SSTATE_NO_SENT: | |
308 | sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer, | |
309 | (jiffies + | |
c9eaf173 | 310 | usecs_to_jiffies(TFRC_INITIAL_TIMEOUT))); |
410e27a4 GR |
311 | hctx->ccid3hctx_last_win_count = 0; |
312 | hctx->ccid3hctx_t_last_win_count = now; | |
90feeb95 GR |
313 | |
314 | /* Set t_0 for initial packet */ | |
410e27a4 GR |
315 | hctx->ccid3hctx_t_nom = now; |
316 | ||
317 | hctx->ccid3hctx_s = skb->len; | |
30833ffe | 318 | |
30833ffe GR |
319 | /* |
320 | * Use initial RTT sample when available: recommended by erratum | |
321 | * to RFC 4342. This implements the initialisation procedure of | |
322 | * draft rfc3448bis, section 4.2. Remember, X is scaled by 2^6. | |
323 | */ | |
324 | if (dp->dccps_syn_rtt) { | |
325 | ccid3_pr_debug("SYN RTT = %uus\n", dp->dccps_syn_rtt); | |
410e27a4 GR |
326 | hctx->ccid3hctx_rtt = dp->dccps_syn_rtt; |
327 | hctx->ccid3hctx_x = rfc3390_initial_rate(sk); | |
328 | hctx->ccid3hctx_t_ld = now; | |
30833ffe | 329 | } else { |
3294f202 GR |
330 | /* |
331 | * Sender does not have RTT sample: | |
332 | * - set fallback RTT (RFC 4340, 3.4) since a RTT value | |
333 | * is needed in several parts (e.g. window counter); | |
334 | * - set sending rate X_pps = 1pps as per RFC 3448, 4.2. | |
335 | */ | |
410e27a4 GR |
336 | hctx->ccid3hctx_rtt = DCCP_FALLBACK_RTT; |
337 | hctx->ccid3hctx_x = hctx->ccid3hctx_s; | |
338 | hctx->ccid3hctx_x <<= 6; | |
30833ffe GR |
339 | } |
340 | ccid3_update_send_interval(hctx); | |
341 | ||
410e27a4 GR |
342 | ccid3_hc_tx_set_state(sk, TFRC_SSTATE_NO_FBACK); |
343 | break; | |
344 | case TFRC_SSTATE_NO_FBACK: | |
345 | case TFRC_SSTATE_FBACK: | |
346 | delay = ktime_us_delta(hctx->ccid3hctx_t_nom, now); | |
8699be7d | 347 | ccid3_pr_debug("delay=%ld\n", (long)delay); |
91cf5a17 | 348 | /* |
8109b02b | 349 | * Scheduling of packet transmissions [RFC 3448, 4.6] |
91cf5a17 GR |
350 | * |
351 | * if (t_now > t_nom - delta) | |
352 | * // send the packet now | |
353 | * else | |
354 | * // send the packet in (t_nom - t_now) milliseconds. | |
355 | */ | |
410e27a4 GR |
356 | if (delay - (s64)hctx->ccid3hctx_delta >= 1000) |
357 | return (u32)delay / 1000L; | |
9f8681db | 358 | |
8132da4d | 359 | ccid3_hc_tx_update_win_count(hctx, now); |
410e27a4 GR |
360 | break; |
361 | case TFRC_SSTATE_TERM: | |
362 | DCCP_BUG("%s(%p) - Illegal state TERM", dccp_role(sk), sk); | |
363 | return -EINVAL; | |
7c657876 ACM |
364 | } |
365 | ||
7da7f456 GR |
366 | /* prepare to send now (add options etc.) */ |
367 | dp->dccps_hc_tx_insert_options = 1; | |
410e27a4 | 368 | DCCP_SKB_CB(skb)->dccpd_ccval = hctx->ccid3hctx_last_win_count; |
e312d100 GR |
369 | |
370 | /* set the nominal send time for the next following packet */ | |
410e27a4 GR |
371 | hctx->ccid3hctx_t_nom = ktime_add_us(hctx->ccid3hctx_t_nom, |
372 | hctx->ccid3hctx_t_ipi); | |
373 | return 0; | |
7c657876 ACM |
374 | } |
375 | ||
410e27a4 GR |
376 | static void ccid3_hc_tx_packet_sent(struct sock *sk, int more, |
377 | unsigned int len) | |
7c657876 | 378 | { |
59725dc2 | 379 | struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); |
7c657876 | 380 | |
410e27a4 | 381 | ccid3_hc_tx_update_s(hctx, len); |
7c657876 | 382 | |
410e27a4 | 383 | if (tfrc_tx_hist_add(&hctx->ccid3hctx_hist, dccp_sk(sk)->dccps_gss)) |
c5a1ae9a | 384 | DCCP_CRIT("packet history - out of memory!"); |
7c657876 ACM |
385 | } |
386 | ||
387 | static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) | |
388 | { | |
59725dc2 | 389 | struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); |
410e27a4 | 390 | struct ccid3_options_received *opt_recv; |
0740d49c | 391 | ktime_t now; |
2a1fda6f | 392 | unsigned long t_nfb; |
410e27a4 | 393 | u32 pinv, r_sample; |
1f2333ae | 394 | |
7c657876 ACM |
395 | /* we are only interested in ACKs */ |
396 | if (!(DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_ACK || | |
397 | DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_DATAACK)) | |
398 | return; | |
410e27a4 GR |
399 | /* ... and only in the established state */ |
400 | if (hctx->ccid3hctx_state != TFRC_SSTATE_FBACK && | |
401 | hctx->ccid3hctx_state != TFRC_SSTATE_NO_FBACK) | |
402 | return; | |
403 | ||
404 | opt_recv = &hctx->ccid3hctx_options_received; | |
405 | now = ktime_get_real(); | |
406 | ||
407 | /* Estimate RTT from history if ACK number is valid */ | |
408 | r_sample = tfrc_tx_hist_rtt(hctx->ccid3hctx_hist, | |
409 | DCCP_SKB_CB(skb)->dccpd_ack_seq, now); | |
410 | if (r_sample == 0) { | |
411 | DCCP_WARN("%s(%p): %s with bogus ACK-%llu\n", dccp_role(sk), sk, | |
412 | dccp_packet_name(DCCP_SKB_CB(skb)->dccpd_type), | |
413 | (unsigned long long)DCCP_SKB_CB(skb)->dccpd_ack_seq); | |
5bd370a6 | 414 | return; |
410e27a4 | 415 | } |
63b3a73b | 416 | |
410e27a4 GR |
417 | /* Update receive rate in units of 64 * bytes/second */ |
418 | hctx->ccid3hctx_x_recv = opt_recv->ccid3or_receive_rate; | |
419 | hctx->ccid3hctx_x_recv <<= 6; | |
7c657876 | 420 | |
410e27a4 GR |
421 | /* Update loss event rate (which is scaled by 1e6) */ |
422 | pinv = opt_recv->ccid3or_loss_event_rate; | |
423 | if (pinv == ~0U || pinv == 0) /* see RFC 4342, 8.5 */ | |
424 | hctx->ccid3hctx_p = 0; | |
425 | else /* can not exceed 100% */ | |
426 | hctx->ccid3hctx_p = scaled_div(1, pinv); | |
427 | /* | |
428 | * Validate new RTT sample and update moving average | |
429 | */ | |
430 | r_sample = dccp_sample_rtt(sk, r_sample); | |
431 | hctx->ccid3hctx_rtt = tfrc_ewma(hctx->ccid3hctx_rtt, r_sample, 9); | |
d8d1252f GR |
432 | /* |
433 | * Update allowed sending rate X as per draft rfc3448bis-00, 4.2/3 | |
434 | */ | |
410e27a4 GR |
435 | if (hctx->ccid3hctx_state == TFRC_SSTATE_NO_FBACK) { |
436 | ccid3_hc_tx_set_state(sk, TFRC_SSTATE_FBACK); | |
5c3fbb6a | 437 | |
410e27a4 | 438 | if (hctx->ccid3hctx_t_rto == 0) { |
d8d1252f GR |
439 | /* |
440 | * Initial feedback packet: Larger Initial Windows (4.2) | |
441 | */ | |
410e27a4 GR |
442 | hctx->ccid3hctx_x = rfc3390_initial_rate(sk); |
443 | hctx->ccid3hctx_t_ld = now; | |
a79ef76f | 444 | |
d8d1252f | 445 | ccid3_update_send_interval(hctx); |
7c657876 | 446 | |
d8d1252f | 447 | goto done_computing_x; |
410e27a4 | 448 | } else if (hctx->ccid3hctx_p == 0) { |
d8d1252f GR |
449 | /* |
450 | * First feedback after nofeedback timer expiry (4.3) | |
451 | */ | |
452 | goto done_computing_x; | |
453 | } | |
454 | } | |
7c657876 | 455 | |
d8d1252f | 456 | /* Update sending rate (step 4 of [RFC 3448, 4.3]) */ |
410e27a4 GR |
457 | if (hctx->ccid3hctx_p > 0) |
458 | hctx->ccid3hctx_x_calc = | |
459 | tfrc_calc_x(hctx->ccid3hctx_s, | |
460 | hctx->ccid3hctx_rtt, | |
461 | hctx->ccid3hctx_p); | |
d8d1252f | 462 | ccid3_hc_tx_update_x(sk, &now); |
7c657876 | 463 | |
d8d1252f GR |
464 | done_computing_x: |
465 | ccid3_pr_debug("%s(%p), RTT=%uus (sample=%uus), s=%u, " | |
5bd370a6 | 466 | "p=%u, X_calc=%u, X_recv=%u, X=%u\n", |
410e27a4 GR |
467 | dccp_role(sk), |
468 | sk, hctx->ccid3hctx_rtt, r_sample, | |
469 | hctx->ccid3hctx_s, hctx->ccid3hctx_p, | |
470 | hctx->ccid3hctx_x_calc, | |
471 | (unsigned)(hctx->ccid3hctx_x_recv >> 6), | |
472 | (unsigned)(hctx->ccid3hctx_x >> 6)); | |
7c657876 | 473 | |
5bd370a6 | 474 | /* unschedule no feedback timer */ |
410e27a4 | 475 | sk_stop_timer(sk, &hctx->ccid3hctx_no_feedback_timer); |
7c657876 | 476 | |
5bd370a6 GR |
477 | /* |
478 | * As we have calculated new ipi, delta, t_nom it is possible | |
479 | * that we now can send a packet, so wake up dccp_wait_for_ccid | |
480 | */ | |
481 | sk->sk_write_space(sk); | |
8c60f3fa | 482 | |
5bd370a6 GR |
483 | /* |
484 | * Update timeout interval for the nofeedback timer. | |
485 | * We use a configuration option to increase the lower bound. | |
486 | * This can help avoid triggering the nofeedback timer too | |
487 | * often ('spinning') on LANs with small RTTs. | |
488 | */ | |
410e27a4 GR |
489 | hctx->ccid3hctx_t_rto = max_t(u32, 4 * hctx->ccid3hctx_rtt, |
490 | (CONFIG_IP_DCCP_CCID3_RTO * | |
491 | (USEC_PER_SEC / 1000))); | |
5bd370a6 GR |
492 | /* |
493 | * Schedule no feedback timer to expire in | |
494 | * max(t_RTO, 2 * s/X) = max(t_RTO, 2 * t_ipi) | |
495 | */ | |
410e27a4 | 496 | t_nfb = max(hctx->ccid3hctx_t_rto, 2 * hctx->ccid3hctx_t_ipi); |
7c657876 | 497 | |
5bd370a6 GR |
498 | ccid3_pr_debug("%s(%p), Scheduled no feedback timer to " |
499 | "expire in %lu jiffies (%luus)\n", | |
410e27a4 GR |
500 | dccp_role(sk), |
501 | sk, usecs_to_jiffies(t_nfb), t_nfb); | |
a9672411 | 502 | |
410e27a4 | 503 | sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer, |
5bd370a6 | 504 | jiffies + usecs_to_jiffies(t_nfb)); |
7c657876 ACM |
505 | } |
506 | ||
410e27a4 GR |
507 | static int ccid3_hc_tx_parse_options(struct sock *sk, unsigned char option, |
508 | unsigned char len, u16 idx, | |
509 | unsigned char *value) | |
7c657876 | 510 | { |
410e27a4 GR |
511 | int rc = 0; |
512 | const struct dccp_sock *dp = dccp_sk(sk); | |
59725dc2 | 513 | struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); |
410e27a4 | 514 | struct ccid3_options_received *opt_recv; |
76fd1e87 | 515 | __be32 opt_val; |
7c657876 | 516 | |
410e27a4 | 517 | opt_recv = &hctx->ccid3hctx_options_received; |
47a61e7b | 518 | |
410e27a4 GR |
519 | if (opt_recv->ccid3or_seqno != dp->dccps_gsr) { |
520 | opt_recv->ccid3or_seqno = dp->dccps_gsr; | |
521 | opt_recv->ccid3or_loss_event_rate = ~0; | |
522 | opt_recv->ccid3or_loss_intervals_idx = 0; | |
523 | opt_recv->ccid3or_loss_intervals_len = 0; | |
524 | opt_recv->ccid3or_receive_rate = 0; | |
525 | } | |
ce177ae2 | 526 | |
410e27a4 GR |
527 | switch (option) { |
528 | case TFRC_OPT_LOSS_EVENT_RATE: | |
529 | if (unlikely(len != 4)) { | |
530 | DCCP_WARN("%s(%p), invalid len %d " | |
531 | "for TFRC_OPT_LOSS_EVENT_RATE\n", | |
532 | dccp_role(sk), sk, len); | |
533 | rc = -EINVAL; | |
47a61e7b | 534 | } else { |
410e27a4 GR |
535 | opt_val = get_unaligned((__be32 *)value); |
536 | opt_recv->ccid3or_loss_event_rate = ntohl(opt_val); | |
47a61e7b | 537 | ccid3_pr_debug("%s(%p), LOSS_EVENT_RATE=%u\n", |
410e27a4 GR |
538 | dccp_role(sk), sk, |
539 | opt_recv->ccid3or_loss_event_rate); | |
7c657876 | 540 | } |
410e27a4 GR |
541 | break; |
542 | case TFRC_OPT_LOSS_INTERVALS: | |
543 | opt_recv->ccid3or_loss_intervals_idx = idx; | |
544 | opt_recv->ccid3or_loss_intervals_len = len; | |
545 | ccid3_pr_debug("%s(%p), LOSS_INTERVALS=(%u, %u)\n", | |
546 | dccp_role(sk), sk, | |
547 | opt_recv->ccid3or_loss_intervals_idx, | |
548 | opt_recv->ccid3or_loss_intervals_len); | |
549 | break; | |
550 | case TFRC_OPT_RECEIVE_RATE: | |
551 | if (unlikely(len != 4)) { | |
552 | DCCP_WARN("%s(%p), invalid len %d " | |
553 | "for TFRC_OPT_RECEIVE_RATE\n", | |
554 | dccp_role(sk), sk, len); | |
555 | rc = -EINVAL; | |
556 | } else { | |
557 | opt_val = get_unaligned((__be32 *)value); | |
558 | opt_recv->ccid3or_receive_rate = ntohl(opt_val); | |
559 | ccid3_pr_debug("%s(%p), RECEIVE_RATE=%u\n", | |
560 | dccp_role(sk), sk, | |
561 | opt_recv->ccid3or_receive_rate); | |
562 | } | |
563 | break; | |
7c657876 | 564 | } |
410e27a4 GR |
565 | |
566 | return rc; | |
7c657876 ACM |
567 | } |
568 | ||
91f0ebf7 | 569 | static int ccid3_hc_tx_init(struct ccid *ccid, struct sock *sk) |
7c657876 | 570 | { |
91f0ebf7 | 571 | struct ccid3_hc_tx_sock *hctx = ccid_priv(ccid); |
7c657876 | 572 | |
410e27a4 GR |
573 | hctx->ccid3hctx_state = TFRC_SSTATE_NO_SENT; |
574 | hctx->ccid3hctx_hist = NULL; | |
575 | setup_timer(&hctx->ccid3hctx_no_feedback_timer, | |
576 | ccid3_hc_tx_no_feedback_timer, (unsigned long)sk); | |
577 | ||
7c657876 ACM |
578 | return 0; |
579 | } | |
580 | ||
581 | static void ccid3_hc_tx_exit(struct sock *sk) | |
582 | { | |
59725dc2 | 583 | struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); |
7c657876 | 584 | |
410e27a4 GR |
585 | ccid3_hc_tx_set_state(sk, TFRC_SSTATE_TERM); |
586 | sk_stop_timer(sk, &hctx->ccid3hctx_no_feedback_timer); | |
587 | ||
588 | tfrc_tx_hist_purge(&hctx->ccid3hctx_hist); | |
7c657876 ACM |
589 | } |
590 | ||
9bf17475 GR |
591 | static void ccid3_hc_tx_get_info(struct sock *sk, struct tcp_info *info) |
592 | { | |
410e27a4 GR |
593 | struct ccid3_hc_tx_sock *hctx; |
594 | ||
595 | /* Listen socks doesn't have a private CCID block */ | |
596 | if (sk->sk_state == DCCP_LISTEN) | |
597 | return; | |
598 | ||
599 | hctx = ccid3_hc_tx_sk(sk); | |
600 | info->tcpi_rto = hctx->ccid3hctx_t_rto; | |
601 | info->tcpi_rtt = hctx->ccid3hctx_rtt; | |
9bf17475 GR |
602 | } |
603 | ||
604 | static int ccid3_hc_tx_getsockopt(struct sock *sk, const int optname, int len, | |
605 | u32 __user *optval, int __user *optlen) | |
606 | { | |
410e27a4 | 607 | const struct ccid3_hc_tx_sock *hctx; |
9bf17475 GR |
608 | const void *val; |
609 | ||
410e27a4 GR |
610 | /* Listen socks doesn't have a private CCID block */ |
611 | if (sk->sk_state == DCCP_LISTEN) | |
612 | return -EINVAL; | |
613 | ||
614 | hctx = ccid3_hc_tx_sk(sk); | |
9bf17475 GR |
615 | switch (optname) { |
616 | case DCCP_SOCKOPT_CCID_TX_INFO: | |
410e27a4 | 617 | if (len < sizeof(hctx->ccid3hctx_tfrc)) |
9bf17475 | 618 | return -EINVAL; |
410e27a4 GR |
619 | len = sizeof(hctx->ccid3hctx_tfrc); |
620 | val = &hctx->ccid3hctx_tfrc; | |
9bf17475 GR |
621 | break; |
622 | default: | |
623 | return -ENOPROTOOPT; | |
624 | } | |
625 | ||
626 | if (put_user(len, optlen) || copy_to_user(optval, val, len)) | |
627 | return -EFAULT; | |
628 | ||
629 | return 0; | |
630 | } | |
631 | ||
7c657876 | 632 | /* |
9bf17475 | 633 | * Receiver Half-Connection Routines |
7c657876 | 634 | */ |
410e27a4 GR |
635 | |
636 | /* CCID3 feedback types */ | |
637 | enum ccid3_fback_type { | |
638 | CCID3_FBACK_NONE = 0, | |
639 | CCID3_FBACK_INITIAL, | |
640 | CCID3_FBACK_PERIODIC, | |
641 | CCID3_FBACK_PARAM_CHANGE | |
642 | }; | |
643 | ||
644 | #ifdef CONFIG_IP_DCCP_CCID3_DEBUG | |
645 | static const char *ccid3_rx_state_name(enum ccid3_hc_rx_states state) | |
646 | { | |
36cbd3dc | 647 | static const char *const ccid3_rx_state_names[] = { |
410e27a4 GR |
648 | [TFRC_RSTATE_NO_DATA] = "NO_DATA", |
649 | [TFRC_RSTATE_DATA] = "DATA", | |
650 | [TFRC_RSTATE_TERM] = "TERM", | |
651 | }; | |
652 | ||
653 | return ccid3_rx_state_names[state]; | |
654 | } | |
655 | #endif | |
656 | ||
657 | static void ccid3_hc_rx_set_state(struct sock *sk, | |
658 | enum ccid3_hc_rx_states state) | |
659 | { | |
660 | struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk); | |
661 | enum ccid3_hc_rx_states oldstate = hcrx->ccid3hcrx_state; | |
662 | ||
663 | ccid3_pr_debug("%s(%p) %-8.8s -> %s\n", | |
664 | dccp_role(sk), sk, ccid3_rx_state_name(oldstate), | |
665 | ccid3_rx_state_name(state)); | |
666 | WARN_ON(state == oldstate); | |
667 | hcrx->ccid3hcrx_state = state; | |
668 | } | |
669 | ||
b84a2189 ACM |
670 | static void ccid3_hc_rx_send_feedback(struct sock *sk, |
671 | const struct sk_buff *skb, | |
672 | enum ccid3_fback_type fbtype) | |
7c657876 | 673 | { |
59725dc2 | 674 | struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk); |
410e27a4 GR |
675 | struct dccp_sock *dp = dccp_sk(sk); |
676 | ktime_t now; | |
677 | s64 delta = 0; | |
678 | ||
679 | if (unlikely(hcrx->ccid3hcrx_state == TFRC_RSTATE_TERM)) | |
680 | return; | |
681 | ||
682 | now = ktime_get_real(); | |
7c657876 | 683 | |
b84a2189 ACM |
684 | switch (fbtype) { |
685 | case CCID3_FBACK_INITIAL: | |
410e27a4 GR |
686 | hcrx->ccid3hcrx_x_recv = 0; |
687 | hcrx->ccid3hcrx_pinv = ~0U; /* see RFC 4342, 8.5 */ | |
7c657876 | 688 | break; |
b84a2189 ACM |
689 | case CCID3_FBACK_PARAM_CHANGE: |
690 | /* | |
691 | * When parameters change (new loss or p > p_prev), we do not | |
692 | * have a reliable estimate for R_m of [RFC 3448, 6.2] and so | |
410e27a4 GR |
693 | * need to reuse the previous value of X_recv. However, when |
694 | * X_recv was 0 (due to early loss), this would kill X down to | |
695 | * s/t_mbi (i.e. one packet in 64 seconds). | |
696 | * To avoid such drastic reduction, we approximate X_recv as | |
697 | * the number of bytes since last feedback. | |
698 | * This is a safe fallback, since X is bounded above by X_calc. | |
b84a2189 | 699 | */ |
410e27a4 GR |
700 | if (hcrx->ccid3hcrx_x_recv > 0) |
701 | break; | |
702 | /* fall through */ | |
b84a2189 | 703 | case CCID3_FBACK_PERIODIC: |
410e27a4 GR |
704 | delta = ktime_us_delta(now, hcrx->ccid3hcrx_tstamp_last_feedback); |
705 | if (delta <= 0) | |
706 | DCCP_BUG("delta (%ld) <= 0", (long)delta); | |
707 | else | |
708 | hcrx->ccid3hcrx_x_recv = | |
709 | scaled_div32(hcrx->ccid3hcrx_bytes_recv, delta); | |
7c657876 | 710 | break; |
b84a2189 | 711 | default: |
7c657876 ACM |
712 | return; |
713 | } | |
714 | ||
410e27a4 GR |
715 | ccid3_pr_debug("Interval %ldusec, X_recv=%u, 1/p=%u\n", (long)delta, |
716 | hcrx->ccid3hcrx_x_recv, hcrx->ccid3hcrx_pinv); | |
7c657876 | 717 | |
410e27a4 GR |
718 | hcrx->ccid3hcrx_tstamp_last_feedback = now; |
719 | hcrx->ccid3hcrx_last_counter = dccp_hdr(skb)->dccph_ccval; | |
720 | hcrx->ccid3hcrx_bytes_recv = 0; | |
68c89ee5 | 721 | |
410e27a4 GR |
722 | dp->dccps_hc_rx_insert_options = 1; |
723 | dccp_send_ack(sk); | |
7c657876 ACM |
724 | } |
725 | ||
2d0817d1 | 726 | static int ccid3_hc_rx_insert_options(struct sock *sk, struct sk_buff *skb) |
7c657876 | 727 | { |
410e27a4 | 728 | const struct ccid3_hc_rx_sock *hcrx; |
60fe62e7 | 729 | __be32 x_recv, pinv; |
7c657876 | 730 | |
59d203f9 | 731 | if (!(sk->sk_state == DCCP_OPEN || sk->sk_state == DCCP_PARTOPEN)) |
2d0817d1 | 732 | return 0; |
7c657876 | 733 | |
410e27a4 GR |
734 | hcrx = ccid3_hc_rx_sk(sk); |
735 | ||
4fded33b | 736 | if (dccp_packet_without_ack(skb)) |
2d0817d1 ACM |
737 | return 0; |
738 | ||
410e27a4 GR |
739 | x_recv = htonl(hcrx->ccid3hcrx_x_recv); |
740 | pinv = htonl(hcrx->ccid3hcrx_pinv); | |
2d0817d1 | 741 | |
385ac2e3 | 742 | if (dccp_insert_option(sk, skb, TFRC_OPT_LOSS_EVENT_RATE, |
8109b02b | 743 | &pinv, sizeof(pinv)) || |
2d0817d1 | 744 | dccp_insert_option(sk, skb, TFRC_OPT_RECEIVE_RATE, |
8109b02b | 745 | &x_recv, sizeof(x_recv))) |
2d0817d1 ACM |
746 | return -1; |
747 | ||
748 | return 0; | |
7c657876 ACM |
749 | } |
750 | ||
aa1b1ff0 GR |
751 | /** |
752 | * ccid3_first_li - Implements [RFC 5348, 6.3.1] | |
954c2db8 GR |
753 | * |
754 | * Determine the length of the first loss interval via inverse lookup. | |
755 | * Assume that X_recv can be computed by the throughput equation | |
756 | * s | |
757 | * X_recv = -------- | |
758 | * R * fval | |
759 | * Find some p such that f(p) = fval; return 1/p (scaled). | |
760 | */ | |
761 | static u32 ccid3_first_li(struct sock *sk) | |
762 | { | |
763 | struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk); | |
410e27a4 | 764 | u32 x_recv, p, delta; |
954c2db8 GR |
765 | u64 fval; |
766 | ||
410e27a4 GR |
767 | if (hcrx->ccid3hcrx_rtt == 0) { |
768 | DCCP_WARN("No RTT estimate available, using fallback RTT\n"); | |
769 | hcrx->ccid3hcrx_rtt = DCCP_FALLBACK_RTT; | |
770 | } | |
d20ed95f | 771 | |
410e27a4 GR |
772 | delta = ktime_to_us(net_timedelta(hcrx->ccid3hcrx_tstamp_last_feedback)); |
773 | x_recv = scaled_div32(hcrx->ccid3hcrx_bytes_recv, delta); | |
774 | if (x_recv == 0) { /* would also trigger divide-by-zero */ | |
775 | DCCP_WARN("X_recv==0\n"); | |
776 | if ((x_recv = hcrx->ccid3hcrx_x_recv) == 0) { | |
777 | DCCP_BUG("stored value of X_recv is zero"); | |
778 | return ~0U; | |
779 | } | |
780 | } | |
954c2db8 | 781 | |
410e27a4 GR |
782 | fval = scaled_div(hcrx->ccid3hcrx_s, hcrx->ccid3hcrx_rtt); |
783 | fval = scaled_div32(fval, x_recv); | |
954c2db8 GR |
784 | p = tfrc_calc_x_reverse_lookup(fval); |
785 | ||
786 | ccid3_pr_debug("%s(%p), receive rate=%u bytes/s, implied " | |
787 | "loss rate=%u\n", dccp_role(sk), sk, x_recv, p); | |
788 | ||
410e27a4 | 789 | return p == 0 ? ~0U : scaled_div(1, p); |
954c2db8 GR |
790 | } |
791 | ||
b84a2189 | 792 | static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb) |
7c657876 | 793 | { |
59725dc2 | 794 | struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk); |
410e27a4 | 795 | enum ccid3_fback_type do_feedback = CCID3_FBACK_NONE; |
5b5d0e70 | 796 | const u64 ndp = dccp_sk(sk)->dccps_options_received.dccpor_ndp; |
b84a2189 ACM |
797 | const bool is_data_packet = dccp_data_packet(skb); |
798 | ||
410e27a4 GR |
799 | if (unlikely(hcrx->ccid3hcrx_state == TFRC_RSTATE_NO_DATA)) { |
800 | if (is_data_packet) { | |
801 | const u32 payload = skb->len - dccp_hdr(skb)->dccph_doff * 4; | |
802 | do_feedback = CCID3_FBACK_INITIAL; | |
803 | ccid3_hc_rx_set_state(sk, TFRC_RSTATE_DATA); | |
804 | hcrx->ccid3hcrx_s = payload; | |
805 | /* | |
806 | * Not necessary to update ccid3hcrx_bytes_recv here, | |
807 | * since X_recv = 0 for the first feedback packet (cf. | |
808 | * RFC 3448, 6.3) -- gerrit | |
809 | */ | |
810 | } | |
811 | goto update_records; | |
812 | } | |
813 | ||
814 | if (tfrc_rx_hist_duplicate(&hcrx->ccid3hcrx_hist, skb)) | |
815 | return; /* done receiving */ | |
816 | ||
817 | if (is_data_packet) { | |
818 | const u32 payload = skb->len - dccp_hdr(skb)->dccph_doff * 4; | |
819 | /* | |
820 | * Update moving-average of s and the sum of received payload bytes | |
821 | */ | |
822 | hcrx->ccid3hcrx_s = tfrc_ewma(hcrx->ccid3hcrx_s, payload, 9); | |
823 | hcrx->ccid3hcrx_bytes_recv += payload; | |
824 | } | |
825 | ||
d20ed95f GR |
826 | /* |
827 | * Perform loss detection and handle pending losses | |
828 | */ | |
410e27a4 GR |
829 | if (tfrc_rx_handle_loss(&hcrx->ccid3hcrx_hist, &hcrx->ccid3hcrx_li_hist, |
830 | skb, ndp, ccid3_first_li, sk)) { | |
831 | do_feedback = CCID3_FBACK_PARAM_CHANGE; | |
832 | goto done_receiving; | |
833 | } | |
834 | ||
835 | if (tfrc_rx_hist_loss_pending(&hcrx->ccid3hcrx_hist)) | |
836 | return; /* done receiving */ | |
837 | ||
88e97a93 | 838 | /* |
410e27a4 | 839 | * Handle data packets: RTT sampling and monitoring p |
88e97a93 | 840 | */ |
410e27a4 GR |
841 | if (unlikely(!is_data_packet)) |
842 | goto update_records; | |
843 | ||
844 | if (!tfrc_lh_is_initialised(&hcrx->ccid3hcrx_li_hist)) { | |
845 | const u32 sample = tfrc_rx_hist_sample_rtt(&hcrx->ccid3hcrx_hist, skb); | |
846 | /* | |
847 | * Empty loss history: no loss so far, hence p stays 0. | |
848 | * Sample RTT values, since an RTT estimate is required for the | |
849 | * computation of p when the first loss occurs; RFC 3448, 6.3.1. | |
850 | */ | |
851 | if (sample != 0) | |
852 | hcrx->ccid3hcrx_rtt = tfrc_ewma(hcrx->ccid3hcrx_rtt, sample, 9); | |
853 | ||
854 | } else if (tfrc_lh_update_i_mean(&hcrx->ccid3hcrx_li_hist, skb)) { | |
855 | /* | |
856 | * Step (3) of [RFC 3448, 6.1]: Recompute I_mean and, if I_mean | |
857 | * has decreased (resp. p has increased), send feedback now. | |
858 | */ | |
859 | do_feedback = CCID3_FBACK_PARAM_CHANGE; | |
860 | } | |
861 | ||
b84a2189 ACM |
862 | /* |
863 | * Check if the periodic once-per-RTT feedback is due; RFC 4342, 10.3 | |
864 | */ | |
410e27a4 GR |
865 | if (SUB16(dccp_hdr(skb)->dccph_ccval, hcrx->ccid3hcrx_last_counter) > 3) |
866 | do_feedback = CCID3_FBACK_PERIODIC; | |
867 | ||
868 | update_records: | |
869 | tfrc_rx_hist_add_packet(&hcrx->ccid3hcrx_hist, skb, ndp); | |
870 | ||
871 | done_receiving: | |
872 | if (do_feedback) | |
873 | ccid3_hc_rx_send_feedback(sk, skb, do_feedback); | |
7c657876 ACM |
874 | } |
875 | ||
91f0ebf7 | 876 | static int ccid3_hc_rx_init(struct ccid *ccid, struct sock *sk) |
7c657876 | 877 | { |
91f0ebf7 | 878 | struct ccid3_hc_rx_sock *hcrx = ccid_priv(ccid); |
7c657876 | 879 | |
410e27a4 GR |
880 | hcrx->ccid3hcrx_state = TFRC_RSTATE_NO_DATA; |
881 | tfrc_lh_init(&hcrx->ccid3hcrx_li_hist); | |
882 | return tfrc_rx_hist_alloc(&hcrx->ccid3hcrx_hist); | |
7c657876 ACM |
883 | } |
884 | ||
885 | static void ccid3_hc_rx_exit(struct sock *sk) | |
886 | { | |
59725dc2 | 887 | struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk); |
7c657876 | 888 | |
410e27a4 GR |
889 | ccid3_hc_rx_set_state(sk, TFRC_RSTATE_TERM); |
890 | ||
891 | tfrc_rx_hist_purge(&hcrx->ccid3hcrx_hist); | |
892 | tfrc_lh_cleanup(&hcrx->ccid3hcrx_li_hist); | |
7c657876 ACM |
893 | } |
894 | ||
2babe1f6 ACM |
895 | static void ccid3_hc_rx_get_info(struct sock *sk, struct tcp_info *info) |
896 | { | |
410e27a4 GR |
897 | const struct ccid3_hc_rx_sock *hcrx; |
898 | ||
899 | /* Listen socks doesn't have a private CCID block */ | |
900 | if (sk->sk_state == DCCP_LISTEN) | |
901 | return; | |
902 | ||
903 | hcrx = ccid3_hc_rx_sk(sk); | |
904 | info->tcpi_ca_state = hcrx->ccid3hcrx_state; | |
8109b02b | 905 | info->tcpi_options |= TCPI_OPT_TIMESTAMPS; |
410e27a4 | 906 | info->tcpi_rcv_rtt = hcrx->ccid3hcrx_rtt; |
2babe1f6 ACM |
907 | } |
908 | ||
88f964db ACM |
909 | static int ccid3_hc_rx_getsockopt(struct sock *sk, const int optname, int len, |
910 | u32 __user *optval, int __user *optlen) | |
911 | { | |
410e27a4 | 912 | const struct ccid3_hc_rx_sock *hcrx; |
8e138e79 | 913 | struct tfrc_rx_info rx_info; |
88f964db | 914 | const void *val; |
c9eaf173 | 915 | |
410e27a4 GR |
916 | /* Listen socks doesn't have a private CCID block */ |
917 | if (sk->sk_state == DCCP_LISTEN) | |
918 | return -EINVAL; | |
919 | ||
920 | hcrx = ccid3_hc_rx_sk(sk); | |
88f964db ACM |
921 | switch (optname) { |
922 | case DCCP_SOCKOPT_CCID_RX_INFO: | |
8e138e79 | 923 | if (len < sizeof(rx_info)) |
88f964db | 924 | return -EINVAL; |
410e27a4 GR |
925 | rx_info.tfrcrx_x_recv = hcrx->ccid3hcrx_x_recv; |
926 | rx_info.tfrcrx_rtt = hcrx->ccid3hcrx_rtt; | |
927 | rx_info.tfrcrx_p = hcrx->ccid3hcrx_pinv == 0 ? ~0U : | |
928 | scaled_div(1, hcrx->ccid3hcrx_pinv); | |
8e138e79 GR |
929 | len = sizeof(rx_info); |
930 | val = &rx_info; | |
88f964db ACM |
931 | break; |
932 | default: | |
933 | return -ENOPROTOOPT; | |
934 | } | |
935 | ||
936 | if (put_user(len, optlen) || copy_to_user(optval, val, len)) | |
937 | return -EFAULT; | |
938 | ||
939 | return 0; | |
940 | } | |
941 | ||
ddebc973 | 942 | struct ccid_operations ccid3_ops = { |
3dd9a7c3 | 943 | .ccid_id = DCCPC_CCID3, |
84a97b0a | 944 | .ccid_name = "TCP-Friendly Rate Control", |
91f0ebf7 | 945 | .ccid_hc_tx_obj_size = sizeof(struct ccid3_hc_tx_sock), |
7c657876 ACM |
946 | .ccid_hc_tx_init = ccid3_hc_tx_init, |
947 | .ccid_hc_tx_exit = ccid3_hc_tx_exit, | |
948 | .ccid_hc_tx_send_packet = ccid3_hc_tx_send_packet, | |
949 | .ccid_hc_tx_packet_sent = ccid3_hc_tx_packet_sent, | |
950 | .ccid_hc_tx_packet_recv = ccid3_hc_tx_packet_recv, | |
7c657876 | 951 | .ccid_hc_tx_parse_options = ccid3_hc_tx_parse_options, |
91f0ebf7 | 952 | .ccid_hc_rx_obj_size = sizeof(struct ccid3_hc_rx_sock), |
7c657876 ACM |
953 | .ccid_hc_rx_init = ccid3_hc_rx_init, |
954 | .ccid_hc_rx_exit = ccid3_hc_rx_exit, | |
955 | .ccid_hc_rx_insert_options = ccid3_hc_rx_insert_options, | |
956 | .ccid_hc_rx_packet_recv = ccid3_hc_rx_packet_recv, | |
2babe1f6 ACM |
957 | .ccid_hc_rx_get_info = ccid3_hc_rx_get_info, |
958 | .ccid_hc_tx_get_info = ccid3_hc_tx_get_info, | |
88f964db ACM |
959 | .ccid_hc_rx_getsockopt = ccid3_hc_rx_getsockopt, |
960 | .ccid_hc_tx_getsockopt = ccid3_hc_tx_getsockopt, | |
7c657876 | 961 | }; |
8109b02b | 962 | |
56724aa4 | 963 | #ifdef CONFIG_IP_DCCP_CCID3_DEBUG |
43264991 | 964 | module_param(ccid3_debug, bool, 0644); |
ddebc973 | 965 | MODULE_PARM_DESC(ccid3_debug, "Enable CCID-3 debug messages"); |
56724aa4 | 966 | #endif |