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Commit | Line | Data |
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7c657876 | 1 | /* |
954c2db8 | 2 | * Copyright (c) 2007 The University of Aberdeen, Scotland, UK |
b2f41ff4 IM |
3 | * Copyright (c) 2005-7 The University of Waikato, Hamilton, New Zealand. |
4 | * Copyright (c) 2005-7 Ian McDonald <ian.mcdonald@jandi.co.nz> | |
7c657876 ACM |
5 | * |
6 | * An implementation of the DCCP protocol | |
7 | * | |
8 | * This code has been developed by the University of Waikato WAND | |
9 | * research group. For further information please see http://www.wand.net.nz/ | |
7c657876 ACM |
10 | * |
11 | * This code also uses code from Lulea University, rereleased as GPL by its | |
12 | * authors: | |
13 | * Copyright (c) 2003 Nils-Erik Mattsson, Joacim Haggmark, Magnus Erixzon | |
14 | * | |
15 | * Changes to meet Linux coding standards, to make it meet latest ccid3 draft | |
16 | * and to make it work as a loadable module in the DCCP stack written by | |
17 | * Arnaldo Carvalho de Melo <acme@conectiva.com.br>. | |
18 | * | |
19 | * Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br> | |
20 | * | |
21 | * This program is free software; you can redistribute it and/or modify | |
22 | * it under the terms of the GNU General Public License as published by | |
23 | * the Free Software Foundation; either version 2 of the License, or | |
24 | * (at your option) any later version. | |
25 | * | |
26 | * This program is distributed in the hope that it will be useful, | |
27 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
28 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
29 | * GNU General Public License for more details. | |
30 | * | |
31 | * You should have received a copy of the GNU General Public License | |
32 | * along with this program; if not, write to the Free Software | |
33 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | |
34 | */ | |
7c657876 ACM |
35 | #include "../dccp.h" |
36 | #include "ccid3.h" | |
37 | ||
76fd1e87 GR |
38 | #include <asm/unaligned.h> |
39 | ||
56724aa4 GR |
40 | #ifdef CONFIG_IP_DCCP_CCID3_DEBUG |
41 | static int ccid3_debug; | |
42 | #define ccid3_pr_debug(format, a...) DCCP_PR_DEBUG(ccid3_debug, format, ##a) | |
7c657876 ACM |
43 | #else |
44 | #define ccid3_pr_debug(format, a...) | |
45 | #endif | |
46 | ||
9bf17475 GR |
47 | /* |
48 | * Transmitter Half-Connection Routines | |
49 | */ | |
410e27a4 GR |
50 | #ifdef CONFIG_IP_DCCP_CCID3_DEBUG |
51 | static const char *ccid3_tx_state_name(enum ccid3_hc_tx_states state) | |
52 | { | |
36cbd3dc | 53 | static const char *const ccid3_state_names[] = { |
410e27a4 GR |
54 | [TFRC_SSTATE_NO_SENT] = "NO_SENT", |
55 | [TFRC_SSTATE_NO_FBACK] = "NO_FBACK", | |
56 | [TFRC_SSTATE_FBACK] = "FBACK", | |
57 | [TFRC_SSTATE_TERM] = "TERM", | |
58 | }; | |
59 | ||
60 | return ccid3_state_names[state]; | |
61 | } | |
62 | #endif | |
63 | ||
64 | static void ccid3_hc_tx_set_state(struct sock *sk, | |
65 | enum ccid3_hc_tx_states state) | |
66 | { | |
996ccf49 GR |
67 | struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk); |
68 | enum ccid3_hc_tx_states oldstate = hc->tx_state; | |
410e27a4 GR |
69 | |
70 | ccid3_pr_debug("%s(%p) %-8.8s -> %s\n", | |
71 | dccp_role(sk), sk, ccid3_tx_state_name(oldstate), | |
72 | ccid3_tx_state_name(state)); | |
73 | WARN_ON(state == oldstate); | |
996ccf49 | 74 | hc->tx_state = state; |
410e27a4 | 75 | } |
7c657876 | 76 | |
a21f9f96 | 77 | /* |
6c08b2cf GR |
78 | * Compute the initial sending rate X_init in the manner of RFC 3390: |
79 | * | |
410e27a4 | 80 | * X_init = min(4 * s, max(2 * s, 4380 bytes)) / RTT |
6c08b2cf | 81 | * |
410e27a4 GR |
82 | * Note that RFC 3390 uses MSS, RFC 4342 refers to RFC 3390, and rfc3448bis |
83 | * (rev-02) clarifies the use of RFC 3390 with regard to the above formula. | |
a21f9f96 GR |
84 | * For consistency with other parts of the code, X_init is scaled by 2^6. |
85 | */ | |
86 | static inline u64 rfc3390_initial_rate(struct sock *sk) | |
87 | { | |
996ccf49 GR |
88 | const struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk); |
89 | const __u32 w_init = clamp_t(__u32, 4380U, 2 * hc->tx_s, 4 * hc->tx_s); | |
a21f9f96 | 90 | |
996ccf49 | 91 | return scaled_div(w_init << 6, hc->tx_rtt); |
a21f9f96 GR |
92 | } |
93 | ||
20cbd3e1 GR |
94 | /** |
95 | * ccid3_update_send_interval - Calculate new t_ipi = s / X_inst | |
96 | * This respects the granularity of X_inst (64 * bytes/second). | |
17893bc1 | 97 | */ |
996ccf49 | 98 | static void ccid3_update_send_interval(struct ccid3_hc_tx_sock *hc) |
7c657876 | 99 | { |
996ccf49 | 100 | hc->tx_t_ipi = scaled_div32(((u64)hc->tx_s) << 6, hc->tx_x); |
410e27a4 | 101 | |
20cbd3e1 GR |
102 | ccid3_pr_debug("t_ipi=%u, s=%u, X=%u\n", hc->tx_t_ipi, |
103 | hc->tx_s, (unsigned)(hc->tx_x >> 6)); | |
7c657876 | 104 | } |
aa97efd9 | 105 | |
996ccf49 | 106 | static u32 ccid3_hc_tx_idle_rtt(struct ccid3_hc_tx_sock *hc, ktime_t now) |
a5358fdc | 107 | { |
996ccf49 | 108 | u32 delta = ktime_us_delta(now, hc->tx_t_last_win_count); |
a5358fdc | 109 | |
996ccf49 | 110 | return delta / hc->tx_rtt; |
a5358fdc GR |
111 | } |
112 | ||
aa97efd9 GR |
113 | /** |
114 | * ccid3_hc_tx_update_x - Update allowed sending rate X | |
115 | * @stamp: most recent time if available - can be left NULL. | |
116 | * This function tracks draft rfc3448bis, check there for latest details. | |
5c3fbb6a | 117 | * |
1a21e49a GR |
118 | * Note: X and X_recv are both stored in units of 64 * bytes/second, to support |
119 | * fine-grained resolution of sending rates. This requires scaling by 2^6 | |
120 | * throughout the code. Only X_calc is unscaled (in bytes/second). | |
121 | * | |
1a21e49a | 122 | */ |
aa97efd9 | 123 | static void ccid3_hc_tx_update_x(struct sock *sk, ktime_t *stamp) |
7c657876 | 124 | { |
996ccf49 GR |
125 | struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk); |
126 | __u64 min_rate = 2 * hc->tx_x_recv; | |
127 | const __u64 old_x = hc->tx_x; | |
52515e77 | 128 | ktime_t now = stamp ? *stamp : ktime_get_real(); |
7c657876 | 129 | |
0c150efb GR |
130 | /* |
131 | * Handle IDLE periods: do not reduce below RFC3390 initial sending rate | |
a5358fdc GR |
132 | * when idling [RFC 4342, 5.1]. Definition of idling is from rfc3448bis: |
133 | * a sender is idle if it has not sent anything over a 2-RTT-period. | |
0c150efb GR |
134 | * For consistency with X and X_recv, min_rate is also scaled by 2^6. |
135 | */ | |
996ccf49 | 136 | if (ccid3_hc_tx_idle_rtt(hc, now) >= 2) { |
0c150efb | 137 | min_rate = rfc3390_initial_rate(sk); |
996ccf49 | 138 | min_rate = max(min_rate, 2 * hc->tx_x_recv); |
0c150efb GR |
139 | } |
140 | ||
996ccf49 | 141 | if (hc->tx_p > 0) { |
1a21e49a | 142 | |
996ccf49 GR |
143 | hc->tx_x = min(((__u64)hc->tx_x_calc) << 6, min_rate); |
144 | hc->tx_x = max(hc->tx_x, (((__u64)hc->tx_s) << 6) / TFRC_T_MBI); | |
a79ef76f | 145 | |
996ccf49 | 146 | } else if (ktime_us_delta(now, hc->tx_t_ld) - (s64)hc->tx_rtt >= 0) { |
ac198ea8 | 147 | |
996ccf49 GR |
148 | hc->tx_x = min(2 * hc->tx_x, min_rate); |
149 | hc->tx_x = max(hc->tx_x, | |
150 | scaled_div(((__u64)hc->tx_s) << 6, hc->tx_rtt)); | |
151 | hc->tx_t_ld = now; | |
ff586298 | 152 | } |
b6ee3d4a | 153 | |
996ccf49 | 154 | if (hc->tx_x != old_x) { |
1761f7d7 GR |
155 | ccid3_pr_debug("X_prev=%u, X_now=%u, X_calc=%u, " |
156 | "X_recv=%u\n", (unsigned)(old_x >> 6), | |
996ccf49 GR |
157 | (unsigned)(hc->tx_x >> 6), hc->tx_x_calc, |
158 | (unsigned)(hc->tx_x_recv >> 6)); | |
8699be7d | 159 | |
996ccf49 | 160 | ccid3_update_send_interval(hc); |
8699be7d | 161 | } |
7c657876 ACM |
162 | } |
163 | ||
78ad713d | 164 | /* |
410e27a4 GR |
165 | * Track the mean packet size `s' (cf. RFC 4342, 5.3 and RFC 3448, 4.1) |
166 | * @len: DCCP packet payload size in bytes | |
78ad713d | 167 | */ |
996ccf49 | 168 | static inline void ccid3_hc_tx_update_s(struct ccid3_hc_tx_sock *hc, int len) |
78ad713d | 169 | { |
996ccf49 | 170 | const u16 old_s = hc->tx_s; |
410e27a4 | 171 | |
996ccf49 | 172 | hc->tx_s = tfrc_ewma(hc->tx_s, len, 9); |
410e27a4 | 173 | |
996ccf49 GR |
174 | if (hc->tx_s != old_s) |
175 | ccid3_update_send_interval(hc); | |
78ad713d GR |
176 | } |
177 | ||
9f8681db | 178 | /* |
8109b02b | 179 | * Update Window Counter using the algorithm from [RFC 4342, 8.1]. |
825de27d | 180 | * As elsewhere, RTT > 0 is assumed by using dccp_sample_rtt(). |
9f8681db | 181 | */ |
996ccf49 | 182 | static inline void ccid3_hc_tx_update_win_count(struct ccid3_hc_tx_sock *hc, |
8132da4d | 183 | ktime_t now) |
9f8681db | 184 | { |
996ccf49 GR |
185 | u32 delta = ktime_us_delta(now, hc->tx_t_last_win_count), |
186 | quarter_rtts = (4 * delta) / hc->tx_rtt; | |
9f8681db GR |
187 | |
188 | if (quarter_rtts > 0) { | |
996ccf49 GR |
189 | hc->tx_t_last_win_count = now; |
190 | hc->tx_last_win_count += min(quarter_rtts, 5U); | |
191 | hc->tx_last_win_count &= 0xF; /* mod 16 */ | |
9f8681db GR |
192 | } |
193 | } | |
194 | ||
7c657876 ACM |
195 | static void ccid3_hc_tx_no_feedback_timer(unsigned long data) |
196 | { | |
197 | struct sock *sk = (struct sock *)data; | |
996ccf49 | 198 | struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk); |
2a1fda6f | 199 | unsigned long t_nfb = USEC_PER_SEC / 5; |
7c657876 ACM |
200 | |
201 | bh_lock_sock(sk); | |
202 | if (sock_owned_by_user(sk)) { | |
203 | /* Try again later. */ | |
204 | /* XXX: set some sensible MIB */ | |
48e03eee | 205 | goto restart_timer; |
7c657876 ACM |
206 | } |
207 | ||
b1383380 | 208 | ccid3_pr_debug("%s(%p, state=%s) - entry\n", dccp_role(sk), sk, |
996ccf49 | 209 | ccid3_tx_state_name(hc->tx_state)); |
a9672411 | 210 | |
996ccf49 | 211 | if (hc->tx_state == TFRC_SSTATE_FBACK) |
410e27a4 | 212 | ccid3_hc_tx_set_state(sk, TFRC_SSTATE_NO_FBACK); |
996ccf49 | 213 | else if (hc->tx_state != TFRC_SSTATE_NO_FBACK) |
d0995e6a GR |
214 | goto out; |
215 | ||
52515e77 GR |
216 | /* |
217 | * Determine new allowed sending rate X as per draft rfc3448bis-00, 4.4 | |
67b67e36 | 218 | * RTO is 0 if and only if no feedback has been received yet. |
52515e77 | 219 | */ |
67b67e36 | 220 | if (hc->tx_t_rto == 0 || hc->tx_p == 0) { |
52515e77 GR |
221 | |
222 | /* halve send rate directly */ | |
996ccf49 GR |
223 | hc->tx_x = max(hc->tx_x / 2, |
224 | (((__u64)hc->tx_s) << 6) / TFRC_T_MBI); | |
225 | ccid3_update_send_interval(hc); | |
52515e77 | 226 | } else { |
1f2333ae | 227 | /* |
52515e77 | 228 | * Modify the cached value of X_recv |
0c150efb | 229 | * |
52515e77 | 230 | * If (X_calc > 2 * X_recv) |
0c150efb GR |
231 | * X_recv = max(X_recv / 2, s / (2 * t_mbi)); |
232 | * Else | |
233 | * X_recv = X_calc / 4; | |
234 | * | |
235 | * Note that X_recv is scaled by 2^6 while X_calc is not | |
1f2333ae | 236 | */ |
996ccf49 | 237 | BUG_ON(hc->tx_p && !hc->tx_x_calc); |
0c150efb | 238 | |
996ccf49 GR |
239 | if (hc->tx_x_calc > (hc->tx_x_recv >> 5)) |
240 | hc->tx_x_recv = | |
241 | max(hc->tx_x_recv / 2, | |
242 | (((__u64)hc->tx_s) << 6) / (2*TFRC_T_MBI)); | |
52515e77 | 243 | else { |
996ccf49 GR |
244 | hc->tx_x_recv = hc->tx_x_calc; |
245 | hc->tx_x_recv <<= 4; | |
7c657876 | 246 | } |
aa97efd9 | 247 | ccid3_hc_tx_update_x(sk, NULL); |
7c657876 | 248 | } |
52515e77 | 249 | ccid3_pr_debug("Reduced X to %llu/64 bytes/sec\n", |
996ccf49 | 250 | (unsigned long long)hc->tx_x); |
52515e77 GR |
251 | |
252 | /* | |
253 | * Set new timeout for the nofeedback timer. | |
254 | * See comments in packet_recv() regarding the value of t_RTO. | |
255 | */ | |
67b67e36 | 256 | if (unlikely(hc->tx_t_rto == 0)) /* no feedback received yet */ |
52515e77 GR |
257 | t_nfb = TFRC_INITIAL_TIMEOUT; |
258 | else | |
996ccf49 | 259 | t_nfb = max(hc->tx_t_rto, 2 * hc->tx_t_ipi); |
7c657876 | 260 | |
48e03eee | 261 | restart_timer: |
996ccf49 | 262 | sk_reset_timer(sk, &hc->tx_no_feedback_timer, |
c9eaf173 | 263 | jiffies + usecs_to_jiffies(t_nfb)); |
7c657876 ACM |
264 | out: |
265 | bh_unlock_sock(sk); | |
266 | sock_put(sk); | |
267 | } | |
268 | ||
410e27a4 GR |
269 | /* |
270 | * returns | |
271 | * > 0: delay (in msecs) that should pass before actually sending | |
272 | * = 0: can send immediately | |
273 | * < 0: error condition; do not send packet | |
7da7f456 | 274 | */ |
6b57c93d | 275 | static int ccid3_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb) |
7c657876 ACM |
276 | { |
277 | struct dccp_sock *dp = dccp_sk(sk); | |
996ccf49 | 278 | struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk); |
8132da4d GR |
279 | ktime_t now = ktime_get_real(); |
280 | s64 delay; | |
7c657876 | 281 | |
7c657876 | 282 | /* |
da335baf GR |
283 | * This function is called only for Data and DataAck packets. Sending |
284 | * zero-sized Data(Ack)s is theoretically possible, but for congestion | |
285 | * control this case is pathological - ignore it. | |
7c657876 | 286 | */ |
6b57c93d | 287 | if (unlikely(skb->len == 0)) |
da335baf | 288 | return -EBADMSG; |
7c657876 | 289 | |
996ccf49 | 290 | switch (hc->tx_state) { |
410e27a4 | 291 | case TFRC_SSTATE_NO_SENT: |
996ccf49 GR |
292 | sk_reset_timer(sk, &hc->tx_no_feedback_timer, (jiffies + |
293 | usecs_to_jiffies(TFRC_INITIAL_TIMEOUT))); | |
294 | hc->tx_last_win_count = 0; | |
295 | hc->tx_t_last_win_count = now; | |
90feeb95 GR |
296 | |
297 | /* Set t_0 for initial packet */ | |
996ccf49 | 298 | hc->tx_t_nom = now; |
410e27a4 | 299 | |
996ccf49 | 300 | hc->tx_s = skb->len; |
30833ffe | 301 | |
30833ffe GR |
302 | /* |
303 | * Use initial RTT sample when available: recommended by erratum | |
304 | * to RFC 4342. This implements the initialisation procedure of | |
305 | * draft rfc3448bis, section 4.2. Remember, X is scaled by 2^6. | |
306 | */ | |
307 | if (dp->dccps_syn_rtt) { | |
308 | ccid3_pr_debug("SYN RTT = %uus\n", dp->dccps_syn_rtt); | |
996ccf49 GR |
309 | hc->tx_rtt = dp->dccps_syn_rtt; |
310 | hc->tx_x = rfc3390_initial_rate(sk); | |
311 | hc->tx_t_ld = now; | |
30833ffe | 312 | } else { |
3294f202 GR |
313 | /* |
314 | * Sender does not have RTT sample: | |
315 | * - set fallback RTT (RFC 4340, 3.4) since a RTT value | |
316 | * is needed in several parts (e.g. window counter); | |
317 | * - set sending rate X_pps = 1pps as per RFC 3448, 4.2. | |
318 | */ | |
996ccf49 GR |
319 | hc->tx_rtt = DCCP_FALLBACK_RTT; |
320 | hc->tx_x = hc->tx_s; | |
321 | hc->tx_x <<= 6; | |
30833ffe | 322 | } |
996ccf49 | 323 | ccid3_update_send_interval(hc); |
30833ffe | 324 | |
410e27a4 GR |
325 | ccid3_hc_tx_set_state(sk, TFRC_SSTATE_NO_FBACK); |
326 | break; | |
327 | case TFRC_SSTATE_NO_FBACK: | |
328 | case TFRC_SSTATE_FBACK: | |
996ccf49 | 329 | delay = ktime_us_delta(hc->tx_t_nom, now); |
8699be7d | 330 | ccid3_pr_debug("delay=%ld\n", (long)delay); |
91cf5a17 | 331 | /* |
20cbd3e1 | 332 | * Scheduling of packet transmissions (RFC 5348, 8.3) |
91cf5a17 GR |
333 | * |
334 | * if (t_now > t_nom - delta) | |
335 | * // send the packet now | |
336 | * else | |
337 | * // send the packet in (t_nom - t_now) milliseconds. | |
338 | */ | |
20cbd3e1 GR |
339 | if (delay >= TFRC_T_DELTA) |
340 | return (u32)delay / USEC_PER_MSEC; | |
9f8681db | 341 | |
996ccf49 | 342 | ccid3_hc_tx_update_win_count(hc, now); |
410e27a4 GR |
343 | break; |
344 | case TFRC_SSTATE_TERM: | |
345 | DCCP_BUG("%s(%p) - Illegal state TERM", dccp_role(sk), sk); | |
346 | return -EINVAL; | |
7c657876 ACM |
347 | } |
348 | ||
7da7f456 GR |
349 | /* prepare to send now (add options etc.) */ |
350 | dp->dccps_hc_tx_insert_options = 1; | |
996ccf49 | 351 | DCCP_SKB_CB(skb)->dccpd_ccval = hc->tx_last_win_count; |
e312d100 GR |
352 | |
353 | /* set the nominal send time for the next following packet */ | |
996ccf49 | 354 | hc->tx_t_nom = ktime_add_us(hc->tx_t_nom, hc->tx_t_ipi); |
410e27a4 | 355 | return 0; |
7c657876 ACM |
356 | } |
357 | ||
410e27a4 GR |
358 | static void ccid3_hc_tx_packet_sent(struct sock *sk, int more, |
359 | unsigned int len) | |
7c657876 | 360 | { |
996ccf49 | 361 | struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk); |
7c657876 | 362 | |
996ccf49 | 363 | ccid3_hc_tx_update_s(hc, len); |
7c657876 | 364 | |
996ccf49 | 365 | if (tfrc_tx_hist_add(&hc->tx_hist, dccp_sk(sk)->dccps_gss)) |
c5a1ae9a | 366 | DCCP_CRIT("packet history - out of memory!"); |
7c657876 ACM |
367 | } |
368 | ||
369 | static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) | |
370 | { | |
996ccf49 | 371 | struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk); |
67b67e36 | 372 | struct ccid3_options_received *opt_recv = &hc->tx_options_received; |
d2c72630 | 373 | struct tfrc_tx_hist_entry *acked; |
0740d49c | 374 | ktime_t now; |
2a1fda6f | 375 | unsigned long t_nfb; |
410e27a4 | 376 | u32 pinv, r_sample; |
1f2333ae | 377 | |
7c657876 ACM |
378 | /* we are only interested in ACKs */ |
379 | if (!(DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_ACK || | |
380 | DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_DATAACK)) | |
381 | return; | |
410e27a4 | 382 | /* ... and only in the established state */ |
996ccf49 GR |
383 | if (hc->tx_state != TFRC_SSTATE_FBACK && |
384 | hc->tx_state != TFRC_SSTATE_NO_FBACK) | |
410e27a4 GR |
385 | return; |
386 | ||
d2c72630 GR |
387 | /* |
388 | * Locate the acknowledged packet in the TX history. | |
389 | * | |
390 | * Returning "entry not found" here can for instance happen when | |
391 | * - the host has not sent out anything (e.g. a passive server), | |
392 | * - the Ack is outdated (packet with higher Ack number was received), | |
393 | * - it is a bogus Ack (for a packet not sent on this connection). | |
394 | */ | |
395 | acked = tfrc_tx_hist_find_entry(hc->tx_hist, dccp_hdr_ack_seq(skb)); | |
396 | if (acked == NULL) | |
5bd370a6 | 397 | return; |
d2c72630 GR |
398 | /* For the sake of RTT sampling, ignore/remove all older entries */ |
399 | tfrc_tx_hist_purge(&acked->next); | |
400 | ||
401 | /* Update the moving average for the RTT estimate (RFC 3448, 4.3) */ | |
402 | now = ktime_get_real(); | |
403 | r_sample = dccp_sample_rtt(sk, ktime_us_delta(now, acked->stamp)); | |
404 | hc->tx_rtt = tfrc_ewma(hc->tx_rtt, r_sample, 9); | |
63b3a73b | 405 | |
410e27a4 | 406 | /* Update receive rate in units of 64 * bytes/second */ |
996ccf49 GR |
407 | hc->tx_x_recv = opt_recv->ccid3or_receive_rate; |
408 | hc->tx_x_recv <<= 6; | |
7c657876 | 409 | |
410e27a4 GR |
410 | /* Update loss event rate (which is scaled by 1e6) */ |
411 | pinv = opt_recv->ccid3or_loss_event_rate; | |
412 | if (pinv == ~0U || pinv == 0) /* see RFC 4342, 8.5 */ | |
996ccf49 | 413 | hc->tx_p = 0; |
410e27a4 | 414 | else /* can not exceed 100% */ |
996ccf49 | 415 | hc->tx_p = scaled_div(1, pinv); |
d2c72630 | 416 | |
d8d1252f GR |
417 | /* |
418 | * Update allowed sending rate X as per draft rfc3448bis-00, 4.2/3 | |
419 | */ | |
996ccf49 | 420 | if (hc->tx_state == TFRC_SSTATE_NO_FBACK) { |
410e27a4 | 421 | ccid3_hc_tx_set_state(sk, TFRC_SSTATE_FBACK); |
5c3fbb6a | 422 | |
996ccf49 | 423 | if (hc->tx_t_rto == 0) { |
d8d1252f GR |
424 | /* |
425 | * Initial feedback packet: Larger Initial Windows (4.2) | |
426 | */ | |
996ccf49 GR |
427 | hc->tx_x = rfc3390_initial_rate(sk); |
428 | hc->tx_t_ld = now; | |
a79ef76f | 429 | |
996ccf49 | 430 | ccid3_update_send_interval(hc); |
7c657876 | 431 | |
d8d1252f | 432 | goto done_computing_x; |
996ccf49 | 433 | } else if (hc->tx_p == 0) { |
d8d1252f GR |
434 | /* |
435 | * First feedback after nofeedback timer expiry (4.3) | |
436 | */ | |
437 | goto done_computing_x; | |
438 | } | |
439 | } | |
7c657876 | 440 | |
d8d1252f | 441 | /* Update sending rate (step 4 of [RFC 3448, 4.3]) */ |
996ccf49 GR |
442 | if (hc->tx_p > 0) |
443 | hc->tx_x_calc = tfrc_calc_x(hc->tx_s, hc->tx_rtt, hc->tx_p); | |
d8d1252f | 444 | ccid3_hc_tx_update_x(sk, &now); |
7c657876 | 445 | |
d8d1252f GR |
446 | done_computing_x: |
447 | ccid3_pr_debug("%s(%p), RTT=%uus (sample=%uus), s=%u, " | |
5bd370a6 | 448 | "p=%u, X_calc=%u, X_recv=%u, X=%u\n", |
996ccf49 GR |
449 | dccp_role(sk), sk, hc->tx_rtt, r_sample, |
450 | hc->tx_s, hc->tx_p, hc->tx_x_calc, | |
451 | (unsigned)(hc->tx_x_recv >> 6), | |
452 | (unsigned)(hc->tx_x >> 6)); | |
7c657876 | 453 | |
5bd370a6 | 454 | /* unschedule no feedback timer */ |
996ccf49 | 455 | sk_stop_timer(sk, &hc->tx_no_feedback_timer); |
7c657876 | 456 | |
5bd370a6 GR |
457 | /* |
458 | * As we have calculated new ipi, delta, t_nom it is possible | |
459 | * that we now can send a packet, so wake up dccp_wait_for_ccid | |
460 | */ | |
461 | sk->sk_write_space(sk); | |
8c60f3fa | 462 | |
5bd370a6 | 463 | /* |
89858ad1 GR |
464 | * Update timeout interval for the nofeedback timer. In order to control |
465 | * rate halving on networks with very low RTTs (<= 1 ms), use per-route | |
466 | * tunable RTAX_RTO_MIN value as the lower bound. | |
5bd370a6 | 467 | */ |
89858ad1 GR |
468 | hc->tx_t_rto = max_t(u32, 4 * hc->tx_rtt, |
469 | USEC_PER_SEC/HZ * tcp_rto_min(sk)); | |
5bd370a6 GR |
470 | /* |
471 | * Schedule no feedback timer to expire in | |
472 | * max(t_RTO, 2 * s/X) = max(t_RTO, 2 * t_ipi) | |
473 | */ | |
996ccf49 | 474 | t_nfb = max(hc->tx_t_rto, 2 * hc->tx_t_ipi); |
7c657876 | 475 | |
5bd370a6 GR |
476 | ccid3_pr_debug("%s(%p), Scheduled no feedback timer to " |
477 | "expire in %lu jiffies (%luus)\n", | |
388d5e99 | 478 | dccp_role(sk), sk, usecs_to_jiffies(t_nfb), t_nfb); |
a9672411 | 479 | |
996ccf49 | 480 | sk_reset_timer(sk, &hc->tx_no_feedback_timer, |
5bd370a6 | 481 | jiffies + usecs_to_jiffies(t_nfb)); |
7c657876 ACM |
482 | } |
483 | ||
410e27a4 GR |
484 | static int ccid3_hc_tx_parse_options(struct sock *sk, unsigned char option, |
485 | unsigned char len, u16 idx, | |
486 | unsigned char *value) | |
7c657876 | 487 | { |
410e27a4 GR |
488 | int rc = 0; |
489 | const struct dccp_sock *dp = dccp_sk(sk); | |
996ccf49 | 490 | struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk); |
67b67e36 | 491 | struct ccid3_options_received *opt_recv = &hc->tx_options_received; |
76fd1e87 | 492 | __be32 opt_val; |
7c657876 | 493 | |
410e27a4 GR |
494 | if (opt_recv->ccid3or_seqno != dp->dccps_gsr) { |
495 | opt_recv->ccid3or_seqno = dp->dccps_gsr; | |
496 | opt_recv->ccid3or_loss_event_rate = ~0; | |
497 | opt_recv->ccid3or_loss_intervals_idx = 0; | |
498 | opt_recv->ccid3or_loss_intervals_len = 0; | |
499 | opt_recv->ccid3or_receive_rate = 0; | |
500 | } | |
ce177ae2 | 501 | |
410e27a4 GR |
502 | switch (option) { |
503 | case TFRC_OPT_LOSS_EVENT_RATE: | |
504 | if (unlikely(len != 4)) { | |
505 | DCCP_WARN("%s(%p), invalid len %d " | |
506 | "for TFRC_OPT_LOSS_EVENT_RATE\n", | |
507 | dccp_role(sk), sk, len); | |
508 | rc = -EINVAL; | |
47a61e7b | 509 | } else { |
410e27a4 GR |
510 | opt_val = get_unaligned((__be32 *)value); |
511 | opt_recv->ccid3or_loss_event_rate = ntohl(opt_val); | |
47a61e7b | 512 | ccid3_pr_debug("%s(%p), LOSS_EVENT_RATE=%u\n", |
410e27a4 GR |
513 | dccp_role(sk), sk, |
514 | opt_recv->ccid3or_loss_event_rate); | |
7c657876 | 515 | } |
410e27a4 GR |
516 | break; |
517 | case TFRC_OPT_LOSS_INTERVALS: | |
518 | opt_recv->ccid3or_loss_intervals_idx = idx; | |
519 | opt_recv->ccid3or_loss_intervals_len = len; | |
520 | ccid3_pr_debug("%s(%p), LOSS_INTERVALS=(%u, %u)\n", | |
521 | dccp_role(sk), sk, | |
522 | opt_recv->ccid3or_loss_intervals_idx, | |
523 | opt_recv->ccid3or_loss_intervals_len); | |
524 | break; | |
525 | case TFRC_OPT_RECEIVE_RATE: | |
526 | if (unlikely(len != 4)) { | |
527 | DCCP_WARN("%s(%p), invalid len %d " | |
528 | "for TFRC_OPT_RECEIVE_RATE\n", | |
529 | dccp_role(sk), sk, len); | |
530 | rc = -EINVAL; | |
531 | } else { | |
532 | opt_val = get_unaligned((__be32 *)value); | |
533 | opt_recv->ccid3or_receive_rate = ntohl(opt_val); | |
534 | ccid3_pr_debug("%s(%p), RECEIVE_RATE=%u\n", | |
535 | dccp_role(sk), sk, | |
536 | opt_recv->ccid3or_receive_rate); | |
537 | } | |
538 | break; | |
7c657876 | 539 | } |
410e27a4 GR |
540 | |
541 | return rc; | |
7c657876 ACM |
542 | } |
543 | ||
91f0ebf7 | 544 | static int ccid3_hc_tx_init(struct ccid *ccid, struct sock *sk) |
7c657876 | 545 | { |
996ccf49 | 546 | struct ccid3_hc_tx_sock *hc = ccid_priv(ccid); |
7c657876 | 547 | |
996ccf49 GR |
548 | hc->tx_state = TFRC_SSTATE_NO_SENT; |
549 | hc->tx_hist = NULL; | |
550 | setup_timer(&hc->tx_no_feedback_timer, | |
410e27a4 | 551 | ccid3_hc_tx_no_feedback_timer, (unsigned long)sk); |
7c657876 ACM |
552 | return 0; |
553 | } | |
554 | ||
555 | static void ccid3_hc_tx_exit(struct sock *sk) | |
556 | { | |
996ccf49 | 557 | struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk); |
7c657876 | 558 | |
410e27a4 | 559 | ccid3_hc_tx_set_state(sk, TFRC_SSTATE_TERM); |
996ccf49 | 560 | sk_stop_timer(sk, &hc->tx_no_feedback_timer); |
410e27a4 | 561 | |
996ccf49 | 562 | tfrc_tx_hist_purge(&hc->tx_hist); |
7c657876 ACM |
563 | } |
564 | ||
9bf17475 GR |
565 | static void ccid3_hc_tx_get_info(struct sock *sk, struct tcp_info *info) |
566 | { | |
51c22bb5 GR |
567 | info->tcpi_rto = ccid3_hc_tx_sk(sk)->tx_t_rto; |
568 | info->tcpi_rtt = ccid3_hc_tx_sk(sk)->tx_rtt; | |
9bf17475 GR |
569 | } |
570 | ||
571 | static int ccid3_hc_tx_getsockopt(struct sock *sk, const int optname, int len, | |
572 | u32 __user *optval, int __user *optlen) | |
573 | { | |
51c22bb5 | 574 | const struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk); |
67b67e36 | 575 | struct tfrc_tx_info tfrc; |
9bf17475 GR |
576 | const void *val; |
577 | ||
9bf17475 GR |
578 | switch (optname) { |
579 | case DCCP_SOCKOPT_CCID_TX_INFO: | |
67b67e36 | 580 | if (len < sizeof(tfrc)) |
9bf17475 | 581 | return -EINVAL; |
67b67e36 GR |
582 | tfrc.tfrctx_x = hc->tx_x; |
583 | tfrc.tfrctx_x_recv = hc->tx_x_recv; | |
584 | tfrc.tfrctx_x_calc = hc->tx_x_calc; | |
585 | tfrc.tfrctx_rtt = hc->tx_rtt; | |
586 | tfrc.tfrctx_p = hc->tx_p; | |
587 | tfrc.tfrctx_rto = hc->tx_t_rto; | |
588 | tfrc.tfrctx_ipi = hc->tx_t_ipi; | |
589 | len = sizeof(tfrc); | |
590 | val = &tfrc; | |
9bf17475 GR |
591 | break; |
592 | default: | |
593 | return -ENOPROTOOPT; | |
594 | } | |
595 | ||
596 | if (put_user(len, optlen) || copy_to_user(optval, val, len)) | |
597 | return -EFAULT; | |
598 | ||
599 | return 0; | |
600 | } | |
601 | ||
7c657876 | 602 | /* |
9bf17475 | 603 | * Receiver Half-Connection Routines |
7c657876 | 604 | */ |
410e27a4 GR |
605 | |
606 | /* CCID3 feedback types */ | |
607 | enum ccid3_fback_type { | |
608 | CCID3_FBACK_NONE = 0, | |
609 | CCID3_FBACK_INITIAL, | |
610 | CCID3_FBACK_PERIODIC, | |
611 | CCID3_FBACK_PARAM_CHANGE | |
612 | }; | |
613 | ||
614 | #ifdef CONFIG_IP_DCCP_CCID3_DEBUG | |
615 | static const char *ccid3_rx_state_name(enum ccid3_hc_rx_states state) | |
616 | { | |
36cbd3dc | 617 | static const char *const ccid3_rx_state_names[] = { |
410e27a4 GR |
618 | [TFRC_RSTATE_NO_DATA] = "NO_DATA", |
619 | [TFRC_RSTATE_DATA] = "DATA", | |
620 | [TFRC_RSTATE_TERM] = "TERM", | |
621 | }; | |
622 | ||
623 | return ccid3_rx_state_names[state]; | |
624 | } | |
625 | #endif | |
626 | ||
627 | static void ccid3_hc_rx_set_state(struct sock *sk, | |
628 | enum ccid3_hc_rx_states state) | |
629 | { | |
996ccf49 GR |
630 | struct ccid3_hc_rx_sock *hc = ccid3_hc_rx_sk(sk); |
631 | enum ccid3_hc_rx_states oldstate = hc->rx_state; | |
410e27a4 GR |
632 | |
633 | ccid3_pr_debug("%s(%p) %-8.8s -> %s\n", | |
634 | dccp_role(sk), sk, ccid3_rx_state_name(oldstate), | |
635 | ccid3_rx_state_name(state)); | |
636 | WARN_ON(state == oldstate); | |
996ccf49 | 637 | hc->rx_state = state; |
410e27a4 GR |
638 | } |
639 | ||
b84a2189 ACM |
640 | static void ccid3_hc_rx_send_feedback(struct sock *sk, |
641 | const struct sk_buff *skb, | |
642 | enum ccid3_fback_type fbtype) | |
7c657876 | 643 | { |
996ccf49 | 644 | struct ccid3_hc_rx_sock *hc = ccid3_hc_rx_sk(sk); |
410e27a4 GR |
645 | struct dccp_sock *dp = dccp_sk(sk); |
646 | ktime_t now; | |
647 | s64 delta = 0; | |
648 | ||
996ccf49 | 649 | if (unlikely(hc->rx_state == TFRC_RSTATE_TERM)) |
410e27a4 GR |
650 | return; |
651 | ||
652 | now = ktime_get_real(); | |
7c657876 | 653 | |
b84a2189 ACM |
654 | switch (fbtype) { |
655 | case CCID3_FBACK_INITIAL: | |
996ccf49 GR |
656 | hc->rx_x_recv = 0; |
657 | hc->rx_pinv = ~0U; /* see RFC 4342, 8.5 */ | |
7c657876 | 658 | break; |
b84a2189 ACM |
659 | case CCID3_FBACK_PARAM_CHANGE: |
660 | /* | |
661 | * When parameters change (new loss or p > p_prev), we do not | |
662 | * have a reliable estimate for R_m of [RFC 3448, 6.2] and so | |
410e27a4 GR |
663 | * need to reuse the previous value of X_recv. However, when |
664 | * X_recv was 0 (due to early loss), this would kill X down to | |
665 | * s/t_mbi (i.e. one packet in 64 seconds). | |
666 | * To avoid such drastic reduction, we approximate X_recv as | |
667 | * the number of bytes since last feedback. | |
668 | * This is a safe fallback, since X is bounded above by X_calc. | |
b84a2189 | 669 | */ |
996ccf49 | 670 | if (hc->rx_x_recv > 0) |
410e27a4 GR |
671 | break; |
672 | /* fall through */ | |
b84a2189 | 673 | case CCID3_FBACK_PERIODIC: |
996ccf49 | 674 | delta = ktime_us_delta(now, hc->rx_tstamp_last_feedback); |
410e27a4 GR |
675 | if (delta <= 0) |
676 | DCCP_BUG("delta (%ld) <= 0", (long)delta); | |
677 | else | |
996ccf49 | 678 | hc->rx_x_recv = scaled_div32(hc->rx_bytes_recv, delta); |
7c657876 | 679 | break; |
b84a2189 | 680 | default: |
7c657876 ACM |
681 | return; |
682 | } | |
683 | ||
410e27a4 | 684 | ccid3_pr_debug("Interval %ldusec, X_recv=%u, 1/p=%u\n", (long)delta, |
996ccf49 | 685 | hc->rx_x_recv, hc->rx_pinv); |
7c657876 | 686 | |
996ccf49 GR |
687 | hc->rx_tstamp_last_feedback = now; |
688 | hc->rx_last_counter = dccp_hdr(skb)->dccph_ccval; | |
689 | hc->rx_bytes_recv = 0; | |
68c89ee5 | 690 | |
410e27a4 GR |
691 | dp->dccps_hc_rx_insert_options = 1; |
692 | dccp_send_ack(sk); | |
7c657876 ACM |
693 | } |
694 | ||
2d0817d1 | 695 | static int ccid3_hc_rx_insert_options(struct sock *sk, struct sk_buff *skb) |
7c657876 | 696 | { |
51c22bb5 | 697 | const struct ccid3_hc_rx_sock *hc = ccid3_hc_rx_sk(sk); |
60fe62e7 | 698 | __be32 x_recv, pinv; |
7c657876 | 699 | |
59d203f9 | 700 | if (!(sk->sk_state == DCCP_OPEN || sk->sk_state == DCCP_PARTOPEN)) |
2d0817d1 | 701 | return 0; |
7c657876 | 702 | |
4fded33b | 703 | if (dccp_packet_without_ack(skb)) |
2d0817d1 ACM |
704 | return 0; |
705 | ||
996ccf49 GR |
706 | x_recv = htonl(hc->rx_x_recv); |
707 | pinv = htonl(hc->rx_pinv); | |
2d0817d1 | 708 | |
a7d13fbf | 709 | if (dccp_insert_option(skb, TFRC_OPT_LOSS_EVENT_RATE, |
8109b02b | 710 | &pinv, sizeof(pinv)) || |
a7d13fbf | 711 | dccp_insert_option(skb, TFRC_OPT_RECEIVE_RATE, |
8109b02b | 712 | &x_recv, sizeof(x_recv))) |
2d0817d1 ACM |
713 | return -1; |
714 | ||
715 | return 0; | |
7c657876 ACM |
716 | } |
717 | ||
aa1b1ff0 GR |
718 | /** |
719 | * ccid3_first_li - Implements [RFC 5348, 6.3.1] | |
954c2db8 GR |
720 | * |
721 | * Determine the length of the first loss interval via inverse lookup. | |
722 | * Assume that X_recv can be computed by the throughput equation | |
723 | * s | |
724 | * X_recv = -------- | |
725 | * R * fval | |
726 | * Find some p such that f(p) = fval; return 1/p (scaled). | |
727 | */ | |
728 | static u32 ccid3_first_li(struct sock *sk) | |
729 | { | |
996ccf49 | 730 | struct ccid3_hc_rx_sock *hc = ccid3_hc_rx_sk(sk); |
410e27a4 | 731 | u32 x_recv, p, delta; |
954c2db8 GR |
732 | u64 fval; |
733 | ||
996ccf49 | 734 | if (hc->rx_rtt == 0) { |
410e27a4 | 735 | DCCP_WARN("No RTT estimate available, using fallback RTT\n"); |
996ccf49 | 736 | hc->rx_rtt = DCCP_FALLBACK_RTT; |
410e27a4 | 737 | } |
d20ed95f | 738 | |
996ccf49 GR |
739 | delta = ktime_to_us(net_timedelta(hc->rx_tstamp_last_feedback)); |
740 | x_recv = scaled_div32(hc->rx_bytes_recv, delta); | |
410e27a4 GR |
741 | if (x_recv == 0) { /* would also trigger divide-by-zero */ |
742 | DCCP_WARN("X_recv==0\n"); | |
67b67e36 | 743 | if (hc->rx_x_recv == 0) { |
410e27a4 GR |
744 | DCCP_BUG("stored value of X_recv is zero"); |
745 | return ~0U; | |
746 | } | |
67b67e36 | 747 | x_recv = hc->rx_x_recv; |
410e27a4 | 748 | } |
954c2db8 | 749 | |
996ccf49 | 750 | fval = scaled_div(hc->rx_s, hc->rx_rtt); |
410e27a4 | 751 | fval = scaled_div32(fval, x_recv); |
954c2db8 GR |
752 | p = tfrc_calc_x_reverse_lookup(fval); |
753 | ||
754 | ccid3_pr_debug("%s(%p), receive rate=%u bytes/s, implied " | |
755 | "loss rate=%u\n", dccp_role(sk), sk, x_recv, p); | |
756 | ||
410e27a4 | 757 | return p == 0 ? ~0U : scaled_div(1, p); |
954c2db8 GR |
758 | } |
759 | ||
b84a2189 | 760 | static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb) |
7c657876 | 761 | { |
996ccf49 | 762 | struct ccid3_hc_rx_sock *hc = ccid3_hc_rx_sk(sk); |
410e27a4 | 763 | enum ccid3_fback_type do_feedback = CCID3_FBACK_NONE; |
5b5d0e70 | 764 | const u64 ndp = dccp_sk(sk)->dccps_options_received.dccpor_ndp; |
b84a2189 ACM |
765 | const bool is_data_packet = dccp_data_packet(skb); |
766 | ||
996ccf49 | 767 | if (unlikely(hc->rx_state == TFRC_RSTATE_NO_DATA)) { |
410e27a4 GR |
768 | if (is_data_packet) { |
769 | const u32 payload = skb->len - dccp_hdr(skb)->dccph_doff * 4; | |
770 | do_feedback = CCID3_FBACK_INITIAL; | |
771 | ccid3_hc_rx_set_state(sk, TFRC_RSTATE_DATA); | |
996ccf49 | 772 | hc->rx_s = payload; |
410e27a4 | 773 | /* |
388d5e99 | 774 | * Not necessary to update rx_bytes_recv here, |
410e27a4 GR |
775 | * since X_recv = 0 for the first feedback packet (cf. |
776 | * RFC 3448, 6.3) -- gerrit | |
777 | */ | |
778 | } | |
779 | goto update_records; | |
780 | } | |
781 | ||
996ccf49 | 782 | if (tfrc_rx_hist_duplicate(&hc->rx_hist, skb)) |
410e27a4 GR |
783 | return; /* done receiving */ |
784 | ||
785 | if (is_data_packet) { | |
786 | const u32 payload = skb->len - dccp_hdr(skb)->dccph_doff * 4; | |
787 | /* | |
788 | * Update moving-average of s and the sum of received payload bytes | |
789 | */ | |
996ccf49 GR |
790 | hc->rx_s = tfrc_ewma(hc->rx_s, payload, 9); |
791 | hc->rx_bytes_recv += payload; | |
410e27a4 GR |
792 | } |
793 | ||
d20ed95f GR |
794 | /* |
795 | * Perform loss detection and handle pending losses | |
796 | */ | |
996ccf49 | 797 | if (tfrc_rx_handle_loss(&hc->rx_hist, &hc->rx_li_hist, |
410e27a4 GR |
798 | skb, ndp, ccid3_first_li, sk)) { |
799 | do_feedback = CCID3_FBACK_PARAM_CHANGE; | |
800 | goto done_receiving; | |
801 | } | |
802 | ||
996ccf49 | 803 | if (tfrc_rx_hist_loss_pending(&hc->rx_hist)) |
410e27a4 GR |
804 | return; /* done receiving */ |
805 | ||
88e97a93 | 806 | /* |
410e27a4 | 807 | * Handle data packets: RTT sampling and monitoring p |
88e97a93 | 808 | */ |
410e27a4 GR |
809 | if (unlikely(!is_data_packet)) |
810 | goto update_records; | |
811 | ||
996ccf49 GR |
812 | if (!tfrc_lh_is_initialised(&hc->rx_li_hist)) { |
813 | const u32 sample = tfrc_rx_hist_sample_rtt(&hc->rx_hist, skb); | |
410e27a4 GR |
814 | /* |
815 | * Empty loss history: no loss so far, hence p stays 0. | |
816 | * Sample RTT values, since an RTT estimate is required for the | |
817 | * computation of p when the first loss occurs; RFC 3448, 6.3.1. | |
818 | */ | |
819 | if (sample != 0) | |
996ccf49 | 820 | hc->rx_rtt = tfrc_ewma(hc->rx_rtt, sample, 9); |
410e27a4 | 821 | |
996ccf49 | 822 | } else if (tfrc_lh_update_i_mean(&hc->rx_li_hist, skb)) { |
410e27a4 GR |
823 | /* |
824 | * Step (3) of [RFC 3448, 6.1]: Recompute I_mean and, if I_mean | |
825 | * has decreased (resp. p has increased), send feedback now. | |
826 | */ | |
827 | do_feedback = CCID3_FBACK_PARAM_CHANGE; | |
828 | } | |
829 | ||
b84a2189 ACM |
830 | /* |
831 | * Check if the periodic once-per-RTT feedback is due; RFC 4342, 10.3 | |
832 | */ | |
996ccf49 | 833 | if (SUB16(dccp_hdr(skb)->dccph_ccval, hc->rx_last_counter) > 3) |
410e27a4 GR |
834 | do_feedback = CCID3_FBACK_PERIODIC; |
835 | ||
836 | update_records: | |
996ccf49 | 837 | tfrc_rx_hist_add_packet(&hc->rx_hist, skb, ndp); |
410e27a4 GR |
838 | |
839 | done_receiving: | |
840 | if (do_feedback) | |
841 | ccid3_hc_rx_send_feedback(sk, skb, do_feedback); | |
7c657876 ACM |
842 | } |
843 | ||
91f0ebf7 | 844 | static int ccid3_hc_rx_init(struct ccid *ccid, struct sock *sk) |
7c657876 | 845 | { |
996ccf49 | 846 | struct ccid3_hc_rx_sock *hc = ccid_priv(ccid); |
7c657876 | 847 | |
996ccf49 GR |
848 | hc->rx_state = TFRC_RSTATE_NO_DATA; |
849 | tfrc_lh_init(&hc->rx_li_hist); | |
850 | return tfrc_rx_hist_alloc(&hc->rx_hist); | |
7c657876 ACM |
851 | } |
852 | ||
853 | static void ccid3_hc_rx_exit(struct sock *sk) | |
854 | { | |
996ccf49 | 855 | struct ccid3_hc_rx_sock *hc = ccid3_hc_rx_sk(sk); |
7c657876 | 856 | |
410e27a4 GR |
857 | ccid3_hc_rx_set_state(sk, TFRC_RSTATE_TERM); |
858 | ||
996ccf49 GR |
859 | tfrc_rx_hist_purge(&hc->rx_hist); |
860 | tfrc_lh_cleanup(&hc->rx_li_hist); | |
7c657876 ACM |
861 | } |
862 | ||
2babe1f6 ACM |
863 | static void ccid3_hc_rx_get_info(struct sock *sk, struct tcp_info *info) |
864 | { | |
51c22bb5 | 865 | info->tcpi_ca_state = ccid3_hc_rx_sk(sk)->rx_state; |
8109b02b | 866 | info->tcpi_options |= TCPI_OPT_TIMESTAMPS; |
51c22bb5 | 867 | info->tcpi_rcv_rtt = ccid3_hc_rx_sk(sk)->rx_rtt; |
2babe1f6 ACM |
868 | } |
869 | ||
88f964db ACM |
870 | static int ccid3_hc_rx_getsockopt(struct sock *sk, const int optname, int len, |
871 | u32 __user *optval, int __user *optlen) | |
872 | { | |
51c22bb5 | 873 | const struct ccid3_hc_rx_sock *hc = ccid3_hc_rx_sk(sk); |
8e138e79 | 874 | struct tfrc_rx_info rx_info; |
88f964db | 875 | const void *val; |
c9eaf173 | 876 | |
88f964db ACM |
877 | switch (optname) { |
878 | case DCCP_SOCKOPT_CCID_RX_INFO: | |
8e138e79 | 879 | if (len < sizeof(rx_info)) |
88f964db | 880 | return -EINVAL; |
996ccf49 GR |
881 | rx_info.tfrcrx_x_recv = hc->rx_x_recv; |
882 | rx_info.tfrcrx_rtt = hc->rx_rtt; | |
883 | rx_info.tfrcrx_p = hc->rx_pinv == 0 ? ~0U : | |
884 | scaled_div(1, hc->rx_pinv); | |
8e138e79 GR |
885 | len = sizeof(rx_info); |
886 | val = &rx_info; | |
88f964db ACM |
887 | break; |
888 | default: | |
889 | return -ENOPROTOOPT; | |
890 | } | |
891 | ||
892 | if (put_user(len, optlen) || copy_to_user(optval, val, len)) | |
893 | return -EFAULT; | |
894 | ||
895 | return 0; | |
896 | } | |
897 | ||
ddebc973 | 898 | struct ccid_operations ccid3_ops = { |
3dd9a7c3 | 899 | .ccid_id = DCCPC_CCID3, |
84a97b0a | 900 | .ccid_name = "TCP-Friendly Rate Control", |
91f0ebf7 | 901 | .ccid_hc_tx_obj_size = sizeof(struct ccid3_hc_tx_sock), |
7c657876 ACM |
902 | .ccid_hc_tx_init = ccid3_hc_tx_init, |
903 | .ccid_hc_tx_exit = ccid3_hc_tx_exit, | |
904 | .ccid_hc_tx_send_packet = ccid3_hc_tx_send_packet, | |
905 | .ccid_hc_tx_packet_sent = ccid3_hc_tx_packet_sent, | |
906 | .ccid_hc_tx_packet_recv = ccid3_hc_tx_packet_recv, | |
7c657876 | 907 | .ccid_hc_tx_parse_options = ccid3_hc_tx_parse_options, |
91f0ebf7 | 908 | .ccid_hc_rx_obj_size = sizeof(struct ccid3_hc_rx_sock), |
7c657876 ACM |
909 | .ccid_hc_rx_init = ccid3_hc_rx_init, |
910 | .ccid_hc_rx_exit = ccid3_hc_rx_exit, | |
911 | .ccid_hc_rx_insert_options = ccid3_hc_rx_insert_options, | |
912 | .ccid_hc_rx_packet_recv = ccid3_hc_rx_packet_recv, | |
2babe1f6 ACM |
913 | .ccid_hc_rx_get_info = ccid3_hc_rx_get_info, |
914 | .ccid_hc_tx_get_info = ccid3_hc_tx_get_info, | |
88f964db ACM |
915 | .ccid_hc_rx_getsockopt = ccid3_hc_rx_getsockopt, |
916 | .ccid_hc_tx_getsockopt = ccid3_hc_tx_getsockopt, | |
7c657876 | 917 | }; |
8109b02b | 918 | |
56724aa4 | 919 | #ifdef CONFIG_IP_DCCP_CCID3_DEBUG |
43264991 | 920 | module_param(ccid3_debug, bool, 0644); |
ddebc973 | 921 | MODULE_PARM_DESC(ccid3_debug, "Enable CCID-3 debug messages"); |
56724aa4 | 922 | #endif |