Commit | Line | Data |
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7c657876 ACM |
1 | /* |
2 | * net/dccp/ccids/ccid3.c | |
3 | * | |
b2f41ff4 IM |
4 | * Copyright (c) 2005-7 The University of Waikato, Hamilton, New Zealand. |
5 | * Copyright (c) 2005-7 Ian McDonald <ian.mcdonald@jandi.co.nz> | |
7c657876 ACM |
6 | * |
7 | * An implementation of the DCCP protocol | |
8 | * | |
9 | * This code has been developed by the University of Waikato WAND | |
10 | * research group. For further information please see http://www.wand.net.nz/ | |
7c657876 ACM |
11 | * |
12 | * This code also uses code from Lulea University, rereleased as GPL by its | |
13 | * authors: | |
14 | * Copyright (c) 2003 Nils-Erik Mattsson, Joacim Haggmark, Magnus Erixzon | |
15 | * | |
16 | * Changes to meet Linux coding standards, to make it meet latest ccid3 draft | |
17 | * and to make it work as a loadable module in the DCCP stack written by | |
18 | * Arnaldo Carvalho de Melo <acme@conectiva.com.br>. | |
19 | * | |
20 | * Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br> | |
21 | * | |
22 | * This program is free software; you can redistribute it and/or modify | |
23 | * it under the terms of the GNU General Public License as published by | |
24 | * the Free Software Foundation; either version 2 of the License, or | |
25 | * (at your option) any later version. | |
26 | * | |
27 | * This program is distributed in the hope that it will be useful, | |
28 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
29 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
30 | * GNU General Public License for more details. | |
31 | * | |
32 | * You should have received a copy of the GNU General Public License | |
33 | * along with this program; if not, write to the Free Software | |
34 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | |
35 | */ | |
7c657876 ACM |
36 | #include "../ccid.h" |
37 | #include "../dccp.h" | |
4524b259 | 38 | #include "lib/packet_history.h" |
ae6706f0 | 39 | #include "lib/loss_interval.h" |
36729c1a | 40 | #include "lib/tfrc.h" |
7c657876 ACM |
41 | #include "ccid3.h" |
42 | ||
76fd1e87 GR |
43 | #include <asm/unaligned.h> |
44 | ||
56724aa4 GR |
45 | #ifdef CONFIG_IP_DCCP_CCID3_DEBUG |
46 | static int ccid3_debug; | |
47 | #define ccid3_pr_debug(format, a...) DCCP_PR_DEBUG(ccid3_debug, format, ##a) | |
7c657876 ACM |
48 | #else |
49 | #define ccid3_pr_debug(format, a...) | |
50 | #endif | |
51 | ||
9bf17475 GR |
52 | /* |
53 | * Transmitter Half-Connection Routines | |
54 | */ | |
56724aa4 | 55 | #ifdef CONFIG_IP_DCCP_CCID3_DEBUG |
7c657876 ACM |
56 | static const char *ccid3_tx_state_name(enum ccid3_hc_tx_states state) |
57 | { | |
58 | static char *ccid3_state_names[] = { | |
59 | [TFRC_SSTATE_NO_SENT] = "NO_SENT", | |
60 | [TFRC_SSTATE_NO_FBACK] = "NO_FBACK", | |
61 | [TFRC_SSTATE_FBACK] = "FBACK", | |
62 | [TFRC_SSTATE_TERM] = "TERM", | |
63 | }; | |
64 | ||
65 | return ccid3_state_names[state]; | |
66 | } | |
67 | #endif | |
68 | ||
c25a18ba ACM |
69 | static void ccid3_hc_tx_set_state(struct sock *sk, |
70 | enum ccid3_hc_tx_states state) | |
7c657876 | 71 | { |
59725dc2 | 72 | struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); |
7c657876 ACM |
73 | enum ccid3_hc_tx_states oldstate = hctx->ccid3hctx_state; |
74 | ||
75 | ccid3_pr_debug("%s(%p) %-8.8s -> %s\n", | |
1f2333ae ACM |
76 | dccp_role(sk), sk, ccid3_tx_state_name(oldstate), |
77 | ccid3_tx_state_name(state)); | |
7c657876 ACM |
78 | WARN_ON(state == oldstate); |
79 | hctx->ccid3hctx_state = state; | |
80 | } | |
81 | ||
a21f9f96 | 82 | /* |
6c08b2cf GR |
83 | * Compute the initial sending rate X_init in the manner of RFC 3390: |
84 | * | |
85 | * X_init = min(4 * s, max(2 * s, 4380 bytes)) / RTT | |
86 | * | |
87 | * Note that RFC 3390 uses MSS, RFC 4342 refers to RFC 3390, and rfc3448bis | |
88 | * (rev-02) clarifies the use of RFC 3390 with regard to the above formula. | |
a21f9f96 GR |
89 | * For consistency with other parts of the code, X_init is scaled by 2^6. |
90 | */ | |
91 | static inline u64 rfc3390_initial_rate(struct sock *sk) | |
92 | { | |
6c08b2cf GR |
93 | const struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); |
94 | const __u32 w_init = min_t(__u32, 4 * hctx->ccid3hctx_s, | |
95 | max_t(__u32, 2 * hctx->ccid3hctx_s, 4380)); | |
a21f9f96 | 96 | |
6c08b2cf | 97 | return scaled_div(w_init << 6, hctx->ccid3hctx_rtt); |
a21f9f96 GR |
98 | } |
99 | ||
17893bc1 | 100 | /* |
1266adee | 101 | * Recalculate t_ipi and delta (should be called whenever X changes) |
17893bc1 | 102 | */ |
1266adee | 103 | static inline void ccid3_update_send_interval(struct ccid3_hc_tx_sock *hctx) |
7c657876 | 104 | { |
1a21e49a | 105 | /* Calculate new t_ipi = s / X_inst (X_inst is in 64 * bytes/second) */ |
b2449fdc GR |
106 | hctx->ccid3hctx_t_ipi = scaled_div32(((u64)hctx->ccid3hctx_s) << 6, |
107 | hctx->ccid3hctx_x); | |
7c657876 | 108 | |
17893bc1 | 109 | /* Calculate new delta by delta = min(t_ipi / 2, t_gran / 2) */ |
1f2333ae ACM |
110 | hctx->ccid3hctx_delta = min_t(u32, hctx->ccid3hctx_t_ipi / 2, |
111 | TFRC_OPSYS_HALF_TIME_GRAN); | |
8699be7d | 112 | |
1761f7d7 | 113 | ccid3_pr_debug("t_ipi=%u, delta=%u, s=%u, X=%u\n", |
8699be7d | 114 | hctx->ccid3hctx_t_ipi, hctx->ccid3hctx_delta, |
1761f7d7 | 115 | hctx->ccid3hctx_s, (unsigned)(hctx->ccid3hctx_x >> 6)); |
8699be7d | 116 | |
7c657876 | 117 | } |
aa97efd9 | 118 | |
a5358fdc GR |
119 | static u32 ccid3_hc_tx_idle_rtt(struct ccid3_hc_tx_sock *hctx, ktime_t now) |
120 | { | |
121 | u32 delta = ktime_us_delta(now, hctx->ccid3hctx_t_last_win_count); | |
122 | ||
123 | return delta / hctx->ccid3hctx_rtt; | |
124 | } | |
125 | ||
aa97efd9 GR |
126 | /** |
127 | * ccid3_hc_tx_update_x - Update allowed sending rate X | |
128 | * @stamp: most recent time if available - can be left NULL. | |
129 | * This function tracks draft rfc3448bis, check there for latest details. | |
5c3fbb6a | 130 | * |
1a21e49a GR |
131 | * Note: X and X_recv are both stored in units of 64 * bytes/second, to support |
132 | * fine-grained resolution of sending rates. This requires scaling by 2^6 | |
133 | * throughout the code. Only X_calc is unscaled (in bytes/second). | |
134 | * | |
1a21e49a | 135 | */ |
aa97efd9 | 136 | static void ccid3_hc_tx_update_x(struct sock *sk, ktime_t *stamp) |
a79ef76f | 137 | |
7c657876 | 138 | { |
59725dc2 | 139 | struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); |
0c150efb | 140 | __u64 min_rate = 2 * hctx->ccid3hctx_x_recv; |
1a21e49a | 141 | const __u64 old_x = hctx->ccid3hctx_x; |
aa97efd9 | 142 | ktime_t now = stamp? *stamp : ktime_get_real(); |
7c657876 | 143 | |
0c150efb GR |
144 | /* |
145 | * Handle IDLE periods: do not reduce below RFC3390 initial sending rate | |
a5358fdc GR |
146 | * when idling [RFC 4342, 5.1]. Definition of idling is from rfc3448bis: |
147 | * a sender is idle if it has not sent anything over a 2-RTT-period. | |
0c150efb GR |
148 | * For consistency with X and X_recv, min_rate is also scaled by 2^6. |
149 | */ | |
a5358fdc | 150 | if (ccid3_hc_tx_idle_rtt(hctx, now) >= 2) { |
0c150efb GR |
151 | min_rate = rfc3390_initial_rate(sk); |
152 | min_rate = max(min_rate, 2 * hctx->ccid3hctx_x_recv); | |
153 | } | |
154 | ||
44158306 | 155 | if (hctx->ccid3hctx_p > 0) { |
1a21e49a | 156 | |
9e8efc82 | 157 | hctx->ccid3hctx_x = min(((__u64)hctx->ccid3hctx_x_calc) << 6, |
0c150efb | 158 | min_rate); |
9e8efc82 GR |
159 | hctx->ccid3hctx_x = max(hctx->ccid3hctx_x, |
160 | (((__u64)hctx->ccid3hctx_s) << 6) / | |
8109b02b | 161 | TFRC_T_MBI); |
a79ef76f | 162 | |
aa97efd9 GR |
163 | } else if (ktime_us_delta(now, hctx->ccid3hctx_t_ld) |
164 | - (s64)hctx->ccid3hctx_rtt >= 0) { | |
ac198ea8 | 165 | |
aa97efd9 GR |
166 | hctx->ccid3hctx_x = |
167 | max(min(2 * hctx->ccid3hctx_x, min_rate), | |
168 | scaled_div(((__u64)hctx->ccid3hctx_s) << 6, | |
169 | hctx->ccid3hctx_rtt)); | |
170 | hctx->ccid3hctx_t_ld = now; | |
ff586298 | 171 | } |
b6ee3d4a | 172 | |
8699be7d | 173 | if (hctx->ccid3hctx_x != old_x) { |
1761f7d7 GR |
174 | ccid3_pr_debug("X_prev=%u, X_now=%u, X_calc=%u, " |
175 | "X_recv=%u\n", (unsigned)(old_x >> 6), | |
176 | (unsigned)(hctx->ccid3hctx_x >> 6), | |
177 | hctx->ccid3hctx_x_calc, | |
178 | (unsigned)(hctx->ccid3hctx_x_recv >> 6)); | |
8699be7d | 179 | |
1266adee | 180 | ccid3_update_send_interval(hctx); |
8699be7d | 181 | } |
7c657876 ACM |
182 | } |
183 | ||
78ad713d | 184 | /* |
8109b02b ACM |
185 | * Track the mean packet size `s' (cf. RFC 4342, 5.3 and RFC 3448, 4.1) |
186 | * @len: DCCP packet payload size in bytes | |
78ad713d GR |
187 | */ |
188 | static inline void ccid3_hc_tx_update_s(struct ccid3_hc_tx_sock *hctx, int len) | |
189 | { | |
1266adee GR |
190 | const u16 old_s = hctx->ccid3hctx_s; |
191 | ||
c3ada46a | 192 | hctx->ccid3hctx_s = tfrc_ewma(hctx->ccid3hctx_s, len, 9); |
1266adee GR |
193 | |
194 | if (hctx->ccid3hctx_s != old_s) | |
195 | ccid3_update_send_interval(hctx); | |
78ad713d GR |
196 | } |
197 | ||
9f8681db | 198 | /* |
8109b02b ACM |
199 | * Update Window Counter using the algorithm from [RFC 4342, 8.1]. |
200 | * The algorithm is not applicable if RTT < 4 microseconds. | |
9f8681db GR |
201 | */ |
202 | static inline void ccid3_hc_tx_update_win_count(struct ccid3_hc_tx_sock *hctx, | |
8132da4d | 203 | ktime_t now) |
9f8681db | 204 | { |
9f8681db GR |
205 | u32 quarter_rtts; |
206 | ||
207 | if (unlikely(hctx->ccid3hctx_rtt < 4)) /* avoid divide-by-zero */ | |
208 | return; | |
209 | ||
8132da4d GR |
210 | quarter_rtts = ktime_us_delta(now, hctx->ccid3hctx_t_last_win_count); |
211 | quarter_rtts /= hctx->ccid3hctx_rtt / 4; | |
9f8681db GR |
212 | |
213 | if (quarter_rtts > 0) { | |
8132da4d | 214 | hctx->ccid3hctx_t_last_win_count = now; |
9f8681db GR |
215 | hctx->ccid3hctx_last_win_count += min_t(u32, quarter_rtts, 5); |
216 | hctx->ccid3hctx_last_win_count &= 0xF; /* mod 16 */ | |
9f8681db GR |
217 | } |
218 | } | |
219 | ||
7c657876 ACM |
220 | static void ccid3_hc_tx_no_feedback_timer(unsigned long data) |
221 | { | |
222 | struct sock *sk = (struct sock *)data; | |
59725dc2 | 223 | struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); |
2a1fda6f | 224 | unsigned long t_nfb = USEC_PER_SEC / 5; |
7c657876 ACM |
225 | |
226 | bh_lock_sock(sk); | |
227 | if (sock_owned_by_user(sk)) { | |
228 | /* Try again later. */ | |
229 | /* XXX: set some sensible MIB */ | |
48e03eee | 230 | goto restart_timer; |
7c657876 ACM |
231 | } |
232 | ||
a9672411 | 233 | ccid3_pr_debug("%s(%p, state=%s) - entry \n", dccp_role(sk), sk, |
7c657876 | 234 | ccid3_tx_state_name(hctx->ccid3hctx_state)); |
a9672411 | 235 | |
7c657876 | 236 | switch (hctx->ccid3hctx_state) { |
7c657876 | 237 | case TFRC_SSTATE_NO_FBACK: |
a79ef76f | 238 | /* RFC 3448, 4.4: Halve send rate directly */ |
9e8efc82 GR |
239 | hctx->ccid3hctx_x = max(hctx->ccid3hctx_x / 2, |
240 | (((__u64)hctx->ccid3hctx_s) << 6) / | |
241 | TFRC_T_MBI); | |
7c657876 | 242 | |
a9672411 GR |
243 | ccid3_pr_debug("%s(%p, state=%s), updated tx rate to %u " |
244 | "bytes/s\n", dccp_role(sk), sk, | |
1f2333ae | 245 | ccid3_tx_state_name(hctx->ccid3hctx_state), |
1a21e49a | 246 | (unsigned)(hctx->ccid3hctx_x >> 6)); |
48e03eee | 247 | /* The value of R is still undefined and so we can not recompute |
5e8e034c | 248 | * the timeout value. Keep initial value as per [RFC 4342, 5]. */ |
2a1fda6f | 249 | t_nfb = TFRC_INITIAL_TIMEOUT; |
1266adee | 250 | ccid3_update_send_interval(hctx); |
7c657876 ACM |
251 | break; |
252 | case TFRC_SSTATE_FBACK: | |
1f2333ae | 253 | /* |
0c150efb GR |
254 | * Modify the cached value of X_recv [RFC 3448, 4.4] |
255 | * | |
256 | * If (p == 0 || X_calc > 2 * X_recv) | |
257 | * X_recv = max(X_recv / 2, s / (2 * t_mbi)); | |
258 | * Else | |
259 | * X_recv = X_calc / 4; | |
260 | * | |
261 | * Note that X_recv is scaled by 2^6 while X_calc is not | |
1f2333ae | 262 | */ |
0c150efb GR |
263 | BUG_ON(hctx->ccid3hctx_p && !hctx->ccid3hctx_x_calc); |
264 | ||
265 | if (hctx->ccid3hctx_p == 0 || | |
266 | (hctx->ccid3hctx_x_calc > (hctx->ccid3hctx_x_recv >> 5))) { | |
267 | ||
268 | hctx->ccid3hctx_x_recv = | |
269 | max(hctx->ccid3hctx_x_recv / 2, | |
270 | (((__u64)hctx->ccid3hctx_s) << 6) / | |
271 | (2 * TFRC_T_MBI)); | |
0c150efb GR |
272 | } else { |
273 | hctx->ccid3hctx_x_recv = hctx->ccid3hctx_x_calc; | |
274 | hctx->ccid3hctx_x_recv <<= 4; | |
7c657876 | 275 | } |
0c150efb | 276 | /* Now recalculate X [RFC 3448, 4.3, step (4)] */ |
aa97efd9 | 277 | ccid3_hc_tx_update_x(sk, NULL); |
6b5e633a ACM |
278 | /* |
279 | * Schedule no feedback timer to expire in | |
8a508ac2 GR |
280 | * max(t_RTO, 2 * s/X) = max(t_RTO, 2 * t_ipi) |
281 | * See comments in packet_recv() regarding the value of t_RTO. | |
6b5e633a | 282 | */ |
8a508ac2 | 283 | t_nfb = max(hctx->ccid3hctx_t_rto, 2 * hctx->ccid3hctx_t_ipi); |
7c657876 | 284 | break; |
59348b19 | 285 | case TFRC_SSTATE_NO_SENT: |
a9672411 | 286 | DCCP_BUG("%s(%p) - Illegal state NO_SENT", dccp_role(sk), sk); |
59348b19 GR |
287 | /* fall through */ |
288 | case TFRC_SSTATE_TERM: | |
7c657876 ACM |
289 | goto out; |
290 | } | |
291 | ||
48e03eee GR |
292 | restart_timer: |
293 | sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer, | |
c9eaf173 | 294 | jiffies + usecs_to_jiffies(t_nfb)); |
7c657876 ACM |
295 | out: |
296 | bh_unlock_sock(sk); | |
297 | sock_put(sk); | |
298 | } | |
299 | ||
7da7f456 GR |
300 | /* |
301 | * returns | |
302 | * > 0: delay (in msecs) that should pass before actually sending | |
303 | * = 0: can send immediately | |
304 | * < 0: error condition; do not send packet | |
305 | */ | |
6b57c93d | 306 | static int ccid3_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb) |
7c657876 ACM |
307 | { |
308 | struct dccp_sock *dp = dccp_sk(sk); | |
59725dc2 | 309 | struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); |
8132da4d GR |
310 | ktime_t now = ktime_get_real(); |
311 | s64 delay; | |
7c657876 | 312 | |
7c657876 | 313 | /* |
da335baf GR |
314 | * This function is called only for Data and DataAck packets. Sending |
315 | * zero-sized Data(Ack)s is theoretically possible, but for congestion | |
316 | * control this case is pathological - ignore it. | |
7c657876 | 317 | */ |
6b57c93d | 318 | if (unlikely(skb->len == 0)) |
da335baf | 319 | return -EBADMSG; |
7c657876 | 320 | |
7c657876 ACM |
321 | switch (hctx->ccid3hctx_state) { |
322 | case TFRC_SSTATE_NO_SENT: | |
1f2333ae | 323 | sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer, |
8109b02b | 324 | (jiffies + |
c9eaf173 | 325 | usecs_to_jiffies(TFRC_INITIAL_TIMEOUT))); |
7c657876 ACM |
326 | hctx->ccid3hctx_last_win_count = 0; |
327 | hctx->ccid3hctx_t_last_win_count = now; | |
90feeb95 GR |
328 | |
329 | /* Set t_0 for initial packet */ | |
7c657876 | 330 | hctx->ccid3hctx_t_nom = now; |
30833ffe GR |
331 | |
332 | hctx->ccid3hctx_s = skb->len; | |
333 | ||
334 | /* | |
335 | * Use initial RTT sample when available: recommended by erratum | |
336 | * to RFC 4342. This implements the initialisation procedure of | |
337 | * draft rfc3448bis, section 4.2. Remember, X is scaled by 2^6. | |
338 | */ | |
339 | if (dp->dccps_syn_rtt) { | |
340 | ccid3_pr_debug("SYN RTT = %uus\n", dp->dccps_syn_rtt); | |
341 | hctx->ccid3hctx_rtt = dp->dccps_syn_rtt; | |
342 | hctx->ccid3hctx_x = rfc3390_initial_rate(sk); | |
23f062af | 343 | hctx->ccid3hctx_t_ld = now; |
30833ffe | 344 | } else { |
6c08b2cf GR |
345 | /* Sender does not have RTT sample: X_pps = 1 pkt/sec */ |
346 | hctx->ccid3hctx_x = hctx->ccid3hctx_s; | |
30833ffe GR |
347 | hctx->ccid3hctx_x <<= 6; |
348 | } | |
349 | ccid3_update_send_interval(hctx); | |
350 | ||
351 | ccid3_hc_tx_set_state(sk, TFRC_SSTATE_NO_FBACK); | |
7c657876 ACM |
352 | break; |
353 | case TFRC_SSTATE_NO_FBACK: | |
354 | case TFRC_SSTATE_FBACK: | |
8132da4d | 355 | delay = ktime_us_delta(hctx->ccid3hctx_t_nom, now); |
8699be7d | 356 | ccid3_pr_debug("delay=%ld\n", (long)delay); |
91cf5a17 | 357 | /* |
8109b02b | 358 | * Scheduling of packet transmissions [RFC 3448, 4.6] |
91cf5a17 GR |
359 | * |
360 | * if (t_now > t_nom - delta) | |
361 | * // send the packet now | |
362 | * else | |
363 | * // send the packet in (t_nom - t_now) milliseconds. | |
364 | */ | |
49d66a70 | 365 | if (delay - (s64)hctx->ccid3hctx_delta >= 1000) |
8132da4d | 366 | return (u32)delay / 1000L; |
9f8681db | 367 | |
8132da4d | 368 | ccid3_hc_tx_update_win_count(hctx, now); |
7c657876 | 369 | break; |
59348b19 | 370 | case TFRC_SSTATE_TERM: |
a9672411 | 371 | DCCP_BUG("%s(%p) - Illegal state TERM", dccp_role(sk), sk); |
7da7f456 | 372 | return -EINVAL; |
7c657876 ACM |
373 | } |
374 | ||
7da7f456 GR |
375 | /* prepare to send now (add options etc.) */ |
376 | dp->dccps_hc_tx_insert_options = 1; | |
e312d100 GR |
377 | DCCP_SKB_CB(skb)->dccpd_ccval = hctx->ccid3hctx_last_win_count; |
378 | ||
379 | /* set the nominal send time for the next following packet */ | |
8132da4d GR |
380 | hctx->ccid3hctx_t_nom = ktime_add_us(hctx->ccid3hctx_t_nom, |
381 | hctx->ccid3hctx_t_ipi); | |
7da7f456 | 382 | return 0; |
7c657876 ACM |
383 | } |
384 | ||
8109b02b ACM |
385 | static void ccid3_hc_tx_packet_sent(struct sock *sk, int more, |
386 | unsigned int len) | |
7c657876 | 387 | { |
59725dc2 | 388 | struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); |
7c657876 | 389 | |
6b57c93d | 390 | ccid3_hc_tx_update_s(hctx, len); |
7c657876 | 391 | |
276f2edc | 392 | if (tfrc_tx_hist_add(&hctx->ccid3hctx_hist, dccp_sk(sk)->dccps_gss)) |
c5a1ae9a | 393 | DCCP_CRIT("packet history - out of memory!"); |
7c657876 ACM |
394 | } |
395 | ||
396 | static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) | |
397 | { | |
59725dc2 | 398 | struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); |
7c657876 | 399 | struct ccid3_options_received *opt_recv; |
0740d49c | 400 | ktime_t now; |
2a1fda6f | 401 | unsigned long t_nfb; |
7dfee1a9 | 402 | u32 pinv, r_sample; |
1f2333ae | 403 | |
7c657876 ACM |
404 | /* we are only interested in ACKs */ |
405 | if (!(DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_ACK || | |
406 | DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_DATAACK)) | |
407 | return; | |
408 | ||
409 | opt_recv = &hctx->ccid3hctx_options_received; | |
410 | ||
7c657876 | 411 | switch (hctx->ccid3hctx_state) { |
7c657876 ACM |
412 | case TFRC_SSTATE_NO_FBACK: |
413 | case TFRC_SSTATE_FBACK: | |
9108d5f4 ACM |
414 | now = ktime_get_real(); |
415 | ||
276f2edc | 416 | /* estimate RTT from history if ACK number is valid */ |
9108d5f4 ACM |
417 | r_sample = tfrc_tx_hist_rtt(hctx->ccid3hctx_hist, |
418 | DCCP_SKB_CB(skb)->dccpd_ack_seq, now); | |
419 | if (r_sample == 0) { | |
276f2edc ACM |
420 | DCCP_WARN("%s(%p): %s with bogus ACK-%llu\n", dccp_role(sk), sk, |
421 | dccp_packet_name(DCCP_SKB_CB(skb)->dccpd_type), | |
422 | (unsigned long long)DCCP_SKB_CB(skb)->dccpd_ack_seq); | |
7c657876 ACM |
423 | return; |
424 | } | |
425 | ||
1a21e49a | 426 | /* Update receive rate in units of 64 * bytes/second */ |
9e8efc82 GR |
427 | hctx->ccid3hctx_x_recv = opt_recv->ccid3or_receive_rate; |
428 | hctx->ccid3hctx_x_recv <<= 6; | |
5c3fbb6a GR |
429 | |
430 | /* Update loss event rate */ | |
431 | pinv = opt_recv->ccid3or_loss_event_rate; | |
45393a66 | 432 | if (pinv == ~0U || pinv == 0) /* see RFC 4342, 8.5 */ |
5c3fbb6a | 433 | hctx->ccid3hctx_p = 0; |
45393a66 | 434 | else /* can not exceed 100% */ |
8109b02b | 435 | hctx->ccid3hctx_p = 1000000 / pinv; |
5c3fbb6a | 436 | /* |
9108d5f4 | 437 | * Validate new RTT sample and update moving average |
5c3fbb6a | 438 | */ |
9108d5f4 | 439 | r_sample = dccp_sample_rtt(sk, r_sample); |
c3ada46a | 440 | hctx->ccid3hctx_rtt = tfrc_ewma(hctx->ccid3hctx_rtt, r_sample, 9); |
5c3fbb6a | 441 | |
7c657876 | 442 | if (hctx->ccid3hctx_state == TFRC_SSTATE_NO_FBACK) { |
1a21e49a GR |
443 | /* |
444 | * Larger Initial Windows [RFC 4342, sec. 5] | |
1a21e49a | 445 | */ |
a21f9f96 | 446 | hctx->ccid3hctx_x = rfc3390_initial_rate(sk); |
9823b7b5 | 447 | hctx->ccid3hctx_t_ld = now; |
a79ef76f | 448 | |
1266adee | 449 | ccid3_update_send_interval(hctx); |
7c657876 | 450 | |
a21f9f96 | 451 | ccid3_pr_debug("%s(%p), s=%u, MSS=%u, " |
7dfee1a9 | 452 | "R_sample=%uus, X=%u\n", dccp_role(sk), |
0f08461e | 453 | sk, hctx->ccid3hctx_s, |
1b07a95a | 454 | dccp_sk(sk)->dccps_mss_cache, r_sample, |
1a21e49a | 455 | (unsigned)(hctx->ccid3hctx_x >> 6)); |
7c657876 | 456 | |
5c3fbb6a GR |
457 | ccid3_hc_tx_set_state(sk, TFRC_SSTATE_FBACK); |
458 | } else { | |
7c657876 | 459 | |
ff586298 GR |
460 | /* Update sending rate (step 4 of [RFC 3448, 4.3]) */ |
461 | if (hctx->ccid3hctx_p > 0) | |
462 | hctx->ccid3hctx_x_calc = | |
463 | tfrc_calc_x(hctx->ccid3hctx_s, | |
464 | hctx->ccid3hctx_rtt, | |
465 | hctx->ccid3hctx_p); | |
aa97efd9 | 466 | ccid3_hc_tx_update_x(sk, &now); |
7c657876 | 467 | |
7dfee1a9 | 468 | ccid3_pr_debug("%s(%p), RTT=%uus (sample=%uus), s=%u, " |
8109b02b ACM |
469 | "p=%u, X_calc=%u, X_recv=%u, X=%u\n", |
470 | dccp_role(sk), | |
7dfee1a9 | 471 | sk, hctx->ccid3hctx_rtt, r_sample, |
5c3fbb6a GR |
472 | hctx->ccid3hctx_s, hctx->ccid3hctx_p, |
473 | hctx->ccid3hctx_x_calc, | |
9e8efc82 | 474 | (unsigned)(hctx->ccid3hctx_x_recv >> 6), |
8109b02b | 475 | (unsigned)(hctx->ccid3hctx_x >> 6)); |
7c657876 ACM |
476 | } |
477 | ||
478 | /* unschedule no feedback timer */ | |
479 | sk_stop_timer(sk, &hctx->ccid3hctx_no_feedback_timer); | |
480 | ||
c530cfb1 | 481 | /* |
8109b02b ACM |
482 | * As we have calculated new ipi, delta, t_nom it is possible |
483 | * that we now can send a packet, so wake up dccp_wait_for_ccid | |
c530cfb1 ACM |
484 | */ |
485 | sk->sk_write_space(sk); | |
8c60f3fa | 486 | |
8a508ac2 GR |
487 | /* |
488 | * Update timeout interval for the nofeedback timer. | |
489 | * We use a configuration option to increase the lower bound. | |
8109b02b ACM |
490 | * This can help avoid triggering the nofeedback timer too |
491 | * often ('spinning') on LANs with small RTTs. | |
8a508ac2 | 492 | */ |
5d0dbc4a | 493 | hctx->ccid3hctx_t_rto = max_t(u32, 4 * hctx->ccid3hctx_rtt, |
8a508ac2 | 494 | CONFIG_IP_DCCP_CCID3_RTO * |
8109b02b | 495 | (USEC_PER_SEC/1000)); |
1f2333ae ACM |
496 | /* |
497 | * Schedule no feedback timer to expire in | |
8a508ac2 | 498 | * max(t_RTO, 2 * s/X) = max(t_RTO, 2 * t_ipi) |
1f2333ae | 499 | */ |
8a508ac2 | 500 | t_nfb = max(hctx->ccid3hctx_t_rto, 2 * hctx->ccid3hctx_t_ipi); |
7c657876 | 501 | |
a9672411 | 502 | ccid3_pr_debug("%s(%p), Scheduled no feedback timer to " |
8109b02b ACM |
503 | "expire in %lu jiffies (%luus)\n", |
504 | dccp_role(sk), | |
a9672411 GR |
505 | sk, usecs_to_jiffies(t_nfb), t_nfb); |
506 | ||
507 | sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer, | |
2a1fda6f | 508 | jiffies + usecs_to_jiffies(t_nfb)); |
7c657876 | 509 | break; |
151a9931 | 510 | case TFRC_SSTATE_NO_SENT: /* fall through */ |
5e19e3fc | 511 | case TFRC_SSTATE_TERM: /* ignore feedback when closing */ |
7c657876 ACM |
512 | break; |
513 | } | |
514 | } | |
515 | ||
7c657876 | 516 | static int ccid3_hc_tx_parse_options(struct sock *sk, unsigned char option, |
1f2333ae ACM |
517 | unsigned char len, u16 idx, |
518 | unsigned char *value) | |
7c657876 ACM |
519 | { |
520 | int rc = 0; | |
59725dc2 ACM |
521 | const struct dccp_sock *dp = dccp_sk(sk); |
522 | struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); | |
7c657876 | 523 | struct ccid3_options_received *opt_recv; |
76fd1e87 | 524 | __be32 opt_val; |
7c657876 | 525 | |
7c657876 ACM |
526 | opt_recv = &hctx->ccid3hctx_options_received; |
527 | ||
528 | if (opt_recv->ccid3or_seqno != dp->dccps_gsr) { | |
529 | opt_recv->ccid3or_seqno = dp->dccps_gsr; | |
530 | opt_recv->ccid3or_loss_event_rate = ~0; | |
531 | opt_recv->ccid3or_loss_intervals_idx = 0; | |
532 | opt_recv->ccid3or_loss_intervals_len = 0; | |
533 | opt_recv->ccid3or_receive_rate = 0; | |
534 | } | |
535 | ||
536 | switch (option) { | |
537 | case TFRC_OPT_LOSS_EVENT_RATE: | |
59d203f9 | 538 | if (unlikely(len != 4)) { |
a9672411 | 539 | DCCP_WARN("%s(%p), invalid len %d " |
59348b19 GR |
540 | "for TFRC_OPT_LOSS_EVENT_RATE\n", |
541 | dccp_role(sk), sk, len); | |
7c657876 ACM |
542 | rc = -EINVAL; |
543 | } else { | |
76fd1e87 GR |
544 | opt_val = get_unaligned((__be32 *)value); |
545 | opt_recv->ccid3or_loss_event_rate = ntohl(opt_val); | |
a9672411 | 546 | ccid3_pr_debug("%s(%p), LOSS_EVENT_RATE=%u\n", |
7c657876 ACM |
547 | dccp_role(sk), sk, |
548 | opt_recv->ccid3or_loss_event_rate); | |
549 | } | |
550 | break; | |
551 | case TFRC_OPT_LOSS_INTERVALS: | |
552 | opt_recv->ccid3or_loss_intervals_idx = idx; | |
553 | opt_recv->ccid3or_loss_intervals_len = len; | |
a9672411 | 554 | ccid3_pr_debug("%s(%p), LOSS_INTERVALS=(%u, %u)\n", |
7c657876 ACM |
555 | dccp_role(sk), sk, |
556 | opt_recv->ccid3or_loss_intervals_idx, | |
557 | opt_recv->ccid3or_loss_intervals_len); | |
558 | break; | |
559 | case TFRC_OPT_RECEIVE_RATE: | |
59d203f9 | 560 | if (unlikely(len != 4)) { |
a9672411 | 561 | DCCP_WARN("%s(%p), invalid len %d " |
59348b19 GR |
562 | "for TFRC_OPT_RECEIVE_RATE\n", |
563 | dccp_role(sk), sk, len); | |
7c657876 ACM |
564 | rc = -EINVAL; |
565 | } else { | |
76fd1e87 GR |
566 | opt_val = get_unaligned((__be32 *)value); |
567 | opt_recv->ccid3or_receive_rate = ntohl(opt_val); | |
a9672411 | 568 | ccid3_pr_debug("%s(%p), RECEIVE_RATE=%u\n", |
7c657876 ACM |
569 | dccp_role(sk), sk, |
570 | opt_recv->ccid3or_receive_rate); | |
571 | } | |
572 | break; | |
573 | } | |
574 | ||
575 | return rc; | |
576 | } | |
577 | ||
91f0ebf7 | 578 | static int ccid3_hc_tx_init(struct ccid *ccid, struct sock *sk) |
7c657876 | 579 | { |
91f0ebf7 | 580 | struct ccid3_hc_tx_sock *hctx = ccid_priv(ccid); |
7c657876 | 581 | |
7c657876 | 582 | hctx->ccid3hctx_state = TFRC_SSTATE_NO_SENT; |
276f2edc | 583 | hctx->ccid3hctx_hist = NULL; |
b24b8a24 PE |
584 | setup_timer(&hctx->ccid3hctx_no_feedback_timer, |
585 | ccid3_hc_tx_no_feedback_timer, (unsigned long)sk); | |
7c657876 ACM |
586 | |
587 | return 0; | |
588 | } | |
589 | ||
590 | static void ccid3_hc_tx_exit(struct sock *sk) | |
591 | { | |
59725dc2 | 592 | struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); |
7c657876 | 593 | |
7c657876 ACM |
594 | ccid3_hc_tx_set_state(sk, TFRC_SSTATE_TERM); |
595 | sk_stop_timer(sk, &hctx->ccid3hctx_no_feedback_timer); | |
596 | ||
276f2edc | 597 | tfrc_tx_hist_purge(&hctx->ccid3hctx_hist); |
7c657876 ACM |
598 | } |
599 | ||
9bf17475 GR |
600 | static void ccid3_hc_tx_get_info(struct sock *sk, struct tcp_info *info) |
601 | { | |
2e86908f | 602 | struct ccid3_hc_tx_sock *hctx; |
9bf17475 GR |
603 | |
604 | /* Listen socks doesn't have a private CCID block */ | |
605 | if (sk->sk_state == DCCP_LISTEN) | |
606 | return; | |
607 | ||
2e86908f | 608 | hctx = ccid3_hc_tx_sk(sk); |
9bf17475 GR |
609 | info->tcpi_rto = hctx->ccid3hctx_t_rto; |
610 | info->tcpi_rtt = hctx->ccid3hctx_rtt; | |
611 | } | |
612 | ||
613 | static int ccid3_hc_tx_getsockopt(struct sock *sk, const int optname, int len, | |
614 | u32 __user *optval, int __user *optlen) | |
615 | { | |
2e86908f | 616 | const struct ccid3_hc_tx_sock *hctx; |
9bf17475 GR |
617 | const void *val; |
618 | ||
619 | /* Listen socks doesn't have a private CCID block */ | |
620 | if (sk->sk_state == DCCP_LISTEN) | |
621 | return -EINVAL; | |
622 | ||
2e86908f | 623 | hctx = ccid3_hc_tx_sk(sk); |
9bf17475 GR |
624 | switch (optname) { |
625 | case DCCP_SOCKOPT_CCID_TX_INFO: | |
626 | if (len < sizeof(hctx->ccid3hctx_tfrc)) | |
627 | return -EINVAL; | |
628 | len = sizeof(hctx->ccid3hctx_tfrc); | |
629 | val = &hctx->ccid3hctx_tfrc; | |
630 | break; | |
631 | default: | |
632 | return -ENOPROTOOPT; | |
633 | } | |
634 | ||
635 | if (put_user(len, optlen) || copy_to_user(optval, val, len)) | |
636 | return -EFAULT; | |
637 | ||
638 | return 0; | |
639 | } | |
640 | ||
7c657876 | 641 | /* |
9bf17475 | 642 | * Receiver Half-Connection Routines |
7c657876 | 643 | */ |
b84a2189 ACM |
644 | |
645 | /* CCID3 feedback types */ | |
646 | enum ccid3_fback_type { | |
647 | CCID3_FBACK_NONE = 0, | |
648 | CCID3_FBACK_INITIAL, | |
649 | CCID3_FBACK_PERIODIC, | |
650 | CCID3_FBACK_PARAM_CHANGE | |
651 | }; | |
652 | ||
56724aa4 | 653 | #ifdef CONFIG_IP_DCCP_CCID3_DEBUG |
7c657876 ACM |
654 | static const char *ccid3_rx_state_name(enum ccid3_hc_rx_states state) |
655 | { | |
656 | static char *ccid3_rx_state_names[] = { | |
657 | [TFRC_RSTATE_NO_DATA] = "NO_DATA", | |
658 | [TFRC_RSTATE_DATA] = "DATA", | |
659 | [TFRC_RSTATE_TERM] = "TERM", | |
660 | }; | |
661 | ||
662 | return ccid3_rx_state_names[state]; | |
663 | } | |
664 | #endif | |
665 | ||
c25a18ba ACM |
666 | static void ccid3_hc_rx_set_state(struct sock *sk, |
667 | enum ccid3_hc_rx_states state) | |
7c657876 | 668 | { |
59725dc2 | 669 | struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk); |
7c657876 ACM |
670 | enum ccid3_hc_rx_states oldstate = hcrx->ccid3hcrx_state; |
671 | ||
672 | ccid3_pr_debug("%s(%p) %-8.8s -> %s\n", | |
1f2333ae ACM |
673 | dccp_role(sk), sk, ccid3_rx_state_name(oldstate), |
674 | ccid3_rx_state_name(state)); | |
7c657876 ACM |
675 | WARN_ON(state == oldstate); |
676 | hcrx->ccid3hcrx_state = state; | |
677 | } | |
678 | ||
b84a2189 ACM |
679 | static void ccid3_hc_rx_send_feedback(struct sock *sk, |
680 | const struct sk_buff *skb, | |
681 | enum ccid3_fback_type fbtype) | |
7c657876 | 682 | { |
59725dc2 | 683 | struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk); |
7c657876 | 684 | struct dccp_sock *dp = dccp_sk(sk); |
e7c23357 | 685 | ktime_t now; |
b84a2189 | 686 | s64 delta = 0; |
7c657876 | 687 | |
a9672411 | 688 | ccid3_pr_debug("%s(%p) - entry \n", dccp_role(sk), sk); |
7c657876 | 689 | |
b84a2189 ACM |
690 | if (unlikely(hcrx->ccid3hcrx_state == TFRC_RSTATE_TERM)) |
691 | return; | |
692 | ||
e7a81c6d | 693 | now = ktime_get_real(); |
b6ee3d4a | 694 | |
b84a2189 ACM |
695 | switch (fbtype) { |
696 | case CCID3_FBACK_INITIAL: | |
7c657876 | 697 | hcrx->ccid3hcrx_x_recv = 0; |
b84a2189 | 698 | hcrx->ccid3hcrx_pinv = ~0U; /* see RFC 4342, 8.5 */ |
7c657876 | 699 | break; |
b84a2189 ACM |
700 | case CCID3_FBACK_PARAM_CHANGE: |
701 | /* | |
702 | * When parameters change (new loss or p > p_prev), we do not | |
703 | * have a reliable estimate for R_m of [RFC 3448, 6.2] and so | |
704 | * need to reuse the previous value of X_recv. However, when | |
705 | * X_recv was 0 (due to early loss), this would kill X down to | |
706 | * s/t_mbi (i.e. one packet in 64 seconds). | |
707 | * To avoid such drastic reduction, we approximate X_recv as | |
708 | * the number of bytes since last feedback. | |
709 | * This is a safe fallback, since X is bounded above by X_calc. | |
710 | */ | |
711 | if (hcrx->ccid3hcrx_x_recv > 0) | |
712 | break; | |
713 | /* fall through */ | |
714 | case CCID3_FBACK_PERIODIC: | |
715 | delta = ktime_us_delta(now, hcrx->ccid3hcrx_tstamp_last_feedback); | |
716 | if (delta <= 0) | |
717 | DCCP_BUG("delta (%ld) <= 0", (long)delta); | |
718 | else | |
719 | hcrx->ccid3hcrx_x_recv = | |
720 | scaled_div32(hcrx->ccid3hcrx_bytes_recv, delta); | |
7c657876 | 721 | break; |
b84a2189 | 722 | default: |
7c657876 ACM |
723 | return; |
724 | } | |
725 | ||
b84a2189 ACM |
726 | ccid3_pr_debug("Interval %ldusec, X_recv=%u, 1/p=%u\n", (long)delta, |
727 | hcrx->ccid3hcrx_x_recv, hcrx->ccid3hcrx_pinv); | |
7c657876 | 728 | |
b6ee3d4a | 729 | hcrx->ccid3hcrx_tstamp_last_feedback = now; |
b84a2189 | 730 | hcrx->ccid3hcrx_last_counter = dccp_hdr(skb)->dccph_ccval; |
7c657876 ACM |
731 | hcrx->ccid3hcrx_bytes_recv = 0; |
732 | ||
507d37cf | 733 | dp->dccps_hc_rx_insert_options = 1; |
7c657876 ACM |
734 | dccp_send_ack(sk); |
735 | } | |
736 | ||
2d0817d1 | 737 | static int ccid3_hc_rx_insert_options(struct sock *sk, struct sk_buff *skb) |
7c657876 | 738 | { |
2e86908f | 739 | const struct ccid3_hc_rx_sock *hcrx; |
60fe62e7 | 740 | __be32 x_recv, pinv; |
7c657876 | 741 | |
59d203f9 | 742 | if (!(sk->sk_state == DCCP_OPEN || sk->sk_state == DCCP_PARTOPEN)) |
2d0817d1 | 743 | return 0; |
7c657876 | 744 | |
2e86908f | 745 | hcrx = ccid3_hc_rx_sk(sk); |
4fded33b ACM |
746 | |
747 | if (dccp_packet_without_ack(skb)) | |
2d0817d1 ACM |
748 | return 0; |
749 | ||
4fded33b ACM |
750 | x_recv = htonl(hcrx->ccid3hcrx_x_recv); |
751 | pinv = htonl(hcrx->ccid3hcrx_pinv); | |
2d0817d1 | 752 | |
eb279b79 | 753 | if (dccp_insert_option_timestamp(sk, skb) || |
2d0817d1 | 754 | dccp_insert_option(sk, skb, TFRC_OPT_LOSS_EVENT_RATE, |
8109b02b | 755 | &pinv, sizeof(pinv)) || |
2d0817d1 | 756 | dccp_insert_option(sk, skb, TFRC_OPT_RECEIVE_RATE, |
8109b02b | 757 | &x_recv, sizeof(x_recv))) |
2d0817d1 ACM |
758 | return -1; |
759 | ||
760 | return 0; | |
7c657876 ACM |
761 | } |
762 | ||
b84a2189 | 763 | static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb) |
7c657876 | 764 | { |
59725dc2 | 765 | struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk); |
b84a2189 ACM |
766 | enum ccid3_fback_type do_feedback = CCID3_FBACK_NONE; |
767 | const u32 ndp = dccp_sk(sk)->dccps_options_received.dccpor_ndp; | |
768 | const bool is_data_packet = dccp_data_packet(skb); | |
769 | ||
770 | if (unlikely(hcrx->ccid3hcrx_state == TFRC_RSTATE_NO_DATA)) { | |
771 | if (is_data_packet) { | |
772 | const u32 payload = skb->len - dccp_hdr(skb)->dccph_doff * 4; | |
773 | do_feedback = CCID3_FBACK_INITIAL; | |
774 | ccid3_hc_rx_set_state(sk, TFRC_RSTATE_DATA); | |
775 | hcrx->ccid3hcrx_s = payload; | |
776 | /* | |
777 | * Not necessary to update ccid3hcrx_bytes_recv here, | |
778 | * since X_recv = 0 for the first feedback packet (cf. | |
779 | * RFC 3448, 6.3) -- gerrit | |
780 | */ | |
66a377c5 | 781 | } |
b84a2189 | 782 | goto update_records; |
66a377c5 IM |
783 | } |
784 | ||
b84a2189 ACM |
785 | if (tfrc_rx_hist_duplicate(&hcrx->ccid3hcrx_hist, skb)) |
786 | return; /* done receiving */ | |
7c657876 | 787 | |
b84a2189 ACM |
788 | if (is_data_packet) { |
789 | const u32 payload = skb->len - dccp_hdr(skb)->dccph_doff * 4; | |
790 | /* | |
791 | * Update moving-average of s and the sum of received payload bytes | |
792 | */ | |
793 | hcrx->ccid3hcrx_s = tfrc_ewma(hcrx->ccid3hcrx_s, payload, 9); | |
794 | hcrx->ccid3hcrx_bytes_recv += payload; | |
7c657876 ACM |
795 | } |
796 | ||
b84a2189 ACM |
797 | /* |
798 | * Handle pending losses and otherwise check for new loss | |
799 | */ | |
800 | if (tfrc_rx_hist_new_loss_indicated(&hcrx->ccid3hcrx_hist, skb, ndp)) | |
801 | goto update_records; | |
78ad713d | 802 | |
b84a2189 ACM |
803 | /* |
804 | * Handle data packets: RTT sampling and monitoring p | |
805 | */ | |
806 | if (unlikely(!is_data_packet)) | |
807 | goto update_records; | |
b6ee3d4a | 808 | |
b84a2189 ACM |
809 | if (list_empty(&hcrx->ccid3hcrx_li_hist)) { /* no loss so far: p = 0 */ |
810 | const u32 sample = tfrc_rx_hist_sample_rtt(&hcrx->ccid3hcrx_hist, skb); | |
811 | /* | |
812 | * Empty loss history: no loss so far, hence p stays 0. | |
813 | * Sample RTT values, since an RTT estimate is required for the | |
814 | * computation of p when the first loss occurs; RFC 3448, 6.3.1. | |
815 | */ | |
816 | if (sample != 0) | |
817 | hcrx->ccid3hcrx_rtt = tfrc_ewma(hcrx->ccid3hcrx_rtt, sample, 9); | |
7c657876 ACM |
818 | } |
819 | ||
b84a2189 ACM |
820 | /* |
821 | * Check if the periodic once-per-RTT feedback is due; RFC 4342, 10.3 | |
822 | */ | |
823 | if (SUB16(dccp_hdr(skb)->dccph_ccval, hcrx->ccid3hcrx_last_counter) > 3) | |
824 | do_feedback = CCID3_FBACK_PERIODIC; | |
c0996660 | 825 | |
b84a2189 ACM |
826 | update_records: |
827 | tfrc_rx_hist_add_packet(&hcrx->ccid3hcrx_hist, skb, ndp); | |
7c657876 | 828 | |
b84a2189 ACM |
829 | if (do_feedback) |
830 | ccid3_hc_rx_send_feedback(sk, skb, do_feedback); | |
7c657876 ACM |
831 | } |
832 | ||
91f0ebf7 | 833 | static int ccid3_hc_rx_init(struct ccid *ccid, struct sock *sk) |
7c657876 | 834 | { |
91f0ebf7 | 835 | struct ccid3_hc_rx_sock *hcrx = ccid_priv(ccid); |
7c657876 | 836 | |
a9672411 | 837 | ccid3_pr_debug("entry\n"); |
7c657876 | 838 | |
7c657876 | 839 | hcrx->ccid3hcrx_state = TFRC_RSTATE_NO_DATA; |
ae6706f0 | 840 | INIT_LIST_HEAD(&hcrx->ccid3hcrx_li_hist); |
b84a2189 | 841 | return tfrc_rx_hist_alloc(&hcrx->ccid3hcrx_hist); |
7c657876 ACM |
842 | } |
843 | ||
844 | static void ccid3_hc_rx_exit(struct sock *sk) | |
845 | { | |
59725dc2 | 846 | struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk); |
7c657876 | 847 | |
7c657876 ACM |
848 | ccid3_hc_rx_set_state(sk, TFRC_RSTATE_TERM); |
849 | ||
850 | /* Empty packet history */ | |
d58d1af0 | 851 | tfrc_rx_hist_purge(&hcrx->ccid3hcrx_hist); |
7c657876 ACM |
852 | |
853 | /* Empty loss interval history */ | |
cc4d6a3a | 854 | dccp_li_hist_purge(&hcrx->ccid3hcrx_li_hist); |
7c657876 ACM |
855 | } |
856 | ||
2babe1f6 ACM |
857 | static void ccid3_hc_rx_get_info(struct sock *sk, struct tcp_info *info) |
858 | { | |
2e86908f | 859 | const struct ccid3_hc_rx_sock *hcrx; |
2babe1f6 | 860 | |
59c2353d ACM |
861 | /* Listen socks doesn't have a private CCID block */ |
862 | if (sk->sk_state == DCCP_LISTEN) | |
863 | return; | |
864 | ||
2e86908f | 865 | hcrx = ccid3_hc_rx_sk(sk); |
8109b02b ACM |
866 | info->tcpi_ca_state = hcrx->ccid3hcrx_state; |
867 | info->tcpi_options |= TCPI_OPT_TIMESTAMPS; | |
868 | info->tcpi_rcv_rtt = hcrx->ccid3hcrx_rtt; | |
2babe1f6 ACM |
869 | } |
870 | ||
88f964db ACM |
871 | static int ccid3_hc_rx_getsockopt(struct sock *sk, const int optname, int len, |
872 | u32 __user *optval, int __user *optlen) | |
873 | { | |
2e86908f | 874 | const struct ccid3_hc_rx_sock *hcrx; |
88f964db | 875 | const void *val; |
c9eaf173 | 876 | |
88f964db ACM |
877 | /* Listen socks doesn't have a private CCID block */ |
878 | if (sk->sk_state == DCCP_LISTEN) | |
879 | return -EINVAL; | |
880 | ||
2e86908f | 881 | hcrx = ccid3_hc_rx_sk(sk); |
88f964db ACM |
882 | switch (optname) { |
883 | case DCCP_SOCKOPT_CCID_RX_INFO: | |
884 | if (len < sizeof(hcrx->ccid3hcrx_tfrc)) | |
885 | return -EINVAL; | |
886 | len = sizeof(hcrx->ccid3hcrx_tfrc); | |
887 | val = &hcrx->ccid3hcrx_tfrc; | |
888 | break; | |
889 | default: | |
890 | return -ENOPROTOOPT; | |
891 | } | |
892 | ||
893 | if (put_user(len, optlen) || copy_to_user(optval, val, len)) | |
894 | return -EFAULT; | |
895 | ||
896 | return 0; | |
897 | } | |
898 | ||
91f0ebf7 | 899 | static struct ccid_operations ccid3 = { |
3dd9a7c3 | 900 | .ccid_id = DCCPC_CCID3, |
7c657876 ACM |
901 | .ccid_name = "ccid3", |
902 | .ccid_owner = THIS_MODULE, | |
91f0ebf7 | 903 | .ccid_hc_tx_obj_size = sizeof(struct ccid3_hc_tx_sock), |
7c657876 ACM |
904 | .ccid_hc_tx_init = ccid3_hc_tx_init, |
905 | .ccid_hc_tx_exit = ccid3_hc_tx_exit, | |
906 | .ccid_hc_tx_send_packet = ccid3_hc_tx_send_packet, | |
907 | .ccid_hc_tx_packet_sent = ccid3_hc_tx_packet_sent, | |
908 | .ccid_hc_tx_packet_recv = ccid3_hc_tx_packet_recv, | |
7c657876 | 909 | .ccid_hc_tx_parse_options = ccid3_hc_tx_parse_options, |
91f0ebf7 | 910 | .ccid_hc_rx_obj_size = sizeof(struct ccid3_hc_rx_sock), |
7c657876 ACM |
911 | .ccid_hc_rx_init = ccid3_hc_rx_init, |
912 | .ccid_hc_rx_exit = ccid3_hc_rx_exit, | |
913 | .ccid_hc_rx_insert_options = ccid3_hc_rx_insert_options, | |
914 | .ccid_hc_rx_packet_recv = ccid3_hc_rx_packet_recv, | |
2babe1f6 ACM |
915 | .ccid_hc_rx_get_info = ccid3_hc_rx_get_info, |
916 | .ccid_hc_tx_get_info = ccid3_hc_tx_get_info, | |
88f964db ACM |
917 | .ccid_hc_rx_getsockopt = ccid3_hc_rx_getsockopt, |
918 | .ccid_hc_tx_getsockopt = ccid3_hc_tx_getsockopt, | |
7c657876 | 919 | }; |
8109b02b | 920 | |
56724aa4 | 921 | #ifdef CONFIG_IP_DCCP_CCID3_DEBUG |
042d18f9 | 922 | module_param(ccid3_debug, bool, 0444); |
7c657876 | 923 | MODULE_PARM_DESC(ccid3_debug, "Enable debug messages"); |
56724aa4 | 924 | #endif |
7c657876 ACM |
925 | |
926 | static __init int ccid3_module_init(void) | |
927 | { | |
34a9e7ea | 928 | return ccid_register(&ccid3); |
7c657876 ACM |
929 | } |
930 | module_init(ccid3_module_init); | |
931 | ||
932 | static __exit void ccid3_module_exit(void) | |
933 | { | |
934 | ccid_unregister(&ccid3); | |
7c657876 ACM |
935 | } |
936 | module_exit(ccid3_module_exit); | |
937 | ||
e6bccd35 | 938 | MODULE_AUTHOR("Ian McDonald <ian.mcdonald@jandi.co.nz>, " |
1f2333ae | 939 | "Arnaldo Carvalho de Melo <acme@ghostprotocols.net>"); |
7c657876 ACM |
940 | MODULE_DESCRIPTION("DCCP TFRC CCID3 CCID"); |
941 | MODULE_LICENSE("GPL"); | |
942 | MODULE_ALIAS("net-dccp-ccid-3"); |