1 /* $OpenBSD: ieee80211_amrr.c,v 1.1 2006/06/17 19:07:19 damien Exp $ */
2
3 /*-
4 * Copyright (c) 2010 Rui Paulo <rpaulo@FreeBSD.org>
5 * Copyright (c) 2006
6 * Damien Bergamini <damien.bergamini@free.fr>
7 *
8 * Permission to use, copy, modify, and distribute this software for any
9 * purpose with or without fee is hereby granted, provided that the above
10 * copyright notice and this permission notice appear in all copies.
11 *
12 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
13 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
14 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
15 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
16 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
17 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
18 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
19 */
20
21 #include <sys/cdefs.h>
22 __FBSDID("$FreeBSD: releng/10.2/sys/net80211/ieee80211_amrr.c 252736 2013-07-05 00:03:53Z adrian $");
23
24 /*-
25 * Naive implementation of the Adaptive Multi Rate Retry algorithm:
26 *
27 * "IEEE 802.11 Rate Adaptation: A Practical Approach"
28 * Mathieu Lacage, Hossein Manshaei, Thierry Turletti
29 * INRIA Sophia - Projet Planete
30 * http://www-sop.inria.fr/rapports/sophia/RR-5208.html
31 */
32 #include "opt_wlan.h"
33
34 #include <sys/param.h>
35 #include <sys/kernel.h>
36 #include <sys/module.h>
37 #include <sys/socket.h>
38 #include <sys/sysctl.h>
39
40 #include <net/if.h>
41 #include <net/if_media.h>
42
43 #ifdef INET
44 #include <netinet/in.h>
45 #include <netinet/if_ether.h>
46 #endif
47
48 #include <net80211/ieee80211_var.h>
49 #include <net80211/ieee80211_ht.h>
50 #include <net80211/ieee80211_amrr.h>
51 #include <net80211/ieee80211_ratectl.h>
52
53 #define is_success(amn) \
54 ((amn)->amn_retrycnt < (amn)->amn_txcnt / 10)
55 #define is_failure(amn) \
56 ((amn)->amn_retrycnt > (amn)->amn_txcnt / 3)
57 #define is_enough(amn) \
58 ((amn)->amn_txcnt > 10)
59
60 static void amrr_setinterval(const struct ieee80211vap *, int);
61 static void amrr_init(struct ieee80211vap *);
62 static void amrr_deinit(struct ieee80211vap *);
63 static void amrr_node_init(struct ieee80211_node *);
64 static void amrr_node_deinit(struct ieee80211_node *);
65 static int amrr_update(struct ieee80211_amrr *,
66 struct ieee80211_amrr_node *, struct ieee80211_node *);
67 static int amrr_rate(struct ieee80211_node *, void *, uint32_t);
68 static void amrr_tx_complete(const struct ieee80211vap *,
69 const struct ieee80211_node *, int,
70 void *, void *);
71 static void amrr_tx_update(const struct ieee80211vap *vap,
72 const struct ieee80211_node *, void *, void *, void *);
73 static void amrr_sysctlattach(struct ieee80211vap *,
74 struct sysctl_ctx_list *, struct sysctl_oid *);
75
76 /* number of references from net80211 layer */
77 static int nrefs = 0;
78
79 static const struct ieee80211_ratectl amrr = {
80 .ir_name = "amrr",
81 .ir_attach = NULL,
82 .ir_detach = NULL,
83 .ir_init = amrr_init,
84 .ir_deinit = amrr_deinit,
85 .ir_node_init = amrr_node_init,
86 .ir_node_deinit = amrr_node_deinit,
87 .ir_rate = amrr_rate,
88 .ir_tx_complete = amrr_tx_complete,
89 .ir_tx_update = amrr_tx_update,
90 .ir_setinterval = amrr_setinterval,
91 };
92 IEEE80211_RATECTL_MODULE(amrr, 1);
93 IEEE80211_RATECTL_ALG(amrr, IEEE80211_RATECTL_AMRR, amrr);
94
95 static void
96 amrr_setinterval(const struct ieee80211vap *vap, int msecs)
97 {
98 struct ieee80211_amrr *amrr = vap->iv_rs;
99 int t;
100
101 if (msecs < 100)
102 msecs = 100;
103 t = msecs_to_ticks(msecs);
104 amrr->amrr_interval = (t < 1) ? 1 : t;
105 }
106
107 static void
108 amrr_init(struct ieee80211vap *vap)
109 {
110 struct ieee80211_amrr *amrr;
111
112 KASSERT(vap->iv_rs == NULL, ("%s called multiple times", __func__));
113
114 amrr = vap->iv_rs = malloc(sizeof(struct ieee80211_amrr),
115 M_80211_RATECTL, M_NOWAIT|M_ZERO);
116 if (amrr == NULL) {
117 if_printf(vap->iv_ifp, "couldn't alloc ratectl structure\n");
118 return;
119 }
120 amrr->amrr_min_success_threshold = IEEE80211_AMRR_MIN_SUCCESS_THRESHOLD;
121 amrr->amrr_max_success_threshold = IEEE80211_AMRR_MAX_SUCCESS_THRESHOLD;
122 amrr_setinterval(vap, 500 /* ms */);
123 amrr_sysctlattach(vap, vap->iv_sysctl, vap->iv_oid);
124 }
125
126 static void
127 amrr_deinit(struct ieee80211vap *vap)
128 {
129 free(vap->iv_rs, M_80211_RATECTL);
130 }
131
132 static int
133 amrr_node_is_11n(struct ieee80211_node *ni)
134 {
135
136 if (ni->ni_chan == NULL)
137 return (0);
138 if (ni->ni_chan == IEEE80211_CHAN_ANYC)
139 return (0);
140 return (IEEE80211_IS_CHAN_HT(ni->ni_chan));
141 }
142
143 static void
144 amrr_node_init(struct ieee80211_node *ni)
145 {
146 const struct ieee80211_rateset *rs = NULL;
147 struct ieee80211vap *vap = ni->ni_vap;
148 struct ieee80211_amrr *amrr = vap->iv_rs;
149 struct ieee80211_amrr_node *amn;
150 uint8_t rate;
151
152 if (ni->ni_rctls == NULL) {
153 ni->ni_rctls = amn = malloc(sizeof(struct ieee80211_amrr_node),
154 M_80211_RATECTL, M_NOWAIT|M_ZERO);
155 if (amn == NULL) {
156 if_printf(vap->iv_ifp, "couldn't alloc per-node ratectl "
157 "structure\n");
158 return;
159 }
160 } else
161 amn = ni->ni_rctls;
162 amn->amn_amrr = amrr;
163 amn->amn_success = 0;
164 amn->amn_recovery = 0;
165 amn->amn_txcnt = amn->amn_retrycnt = 0;
166 amn->amn_success_threshold = amrr->amrr_min_success_threshold;
167
168 /* 11n or not? Pick the right rateset */
169 if (amrr_node_is_11n(ni)) {
170 /* XXX ew */
171 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
172 "%s: 11n node", __func__);
173 rs = (struct ieee80211_rateset *) &ni->ni_htrates;
174 } else {
175 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
176 "%s: non-11n node", __func__);
177 rs = &ni->ni_rates;
178 }
179
180 /* Initial rate - lowest */
181 rate = rs->rs_rates[0];
182
183 /* XXX clear the basic rate flag if it's not 11n */
184 if (! amrr_node_is_11n(ni))
185 rate &= IEEE80211_RATE_VAL;
186
187 /* pick initial rate from the rateset - HT or otherwise */
188 for (amn->amn_rix = rs->rs_nrates - 1; amn->amn_rix > 0;
189 amn->amn_rix--) {
190 /* legacy - anything < 36mbit, stop searching */
191 /* 11n - stop at MCS4 / MCS12 / MCS28 */
192 if (amrr_node_is_11n(ni) &&
193 (rs->rs_rates[amn->amn_rix] & 0x7) < 4)
194 break;
195 else if ((rs->rs_rates[amn->amn_rix] & IEEE80211_RATE_VAL) <= 72)
196 break;
197 rate = rs->rs_rates[amn->amn_rix] & IEEE80211_RATE_VAL;
198 }
199
200 /* if the rate is an 11n rate, ensure the MCS bit is set */
201 if (amrr_node_is_11n(ni))
202 rate |= IEEE80211_RATE_MCS;
203
204 /* Assign initial rate from the rateset */
205 ni->ni_txrate = rate;
206 amn->amn_ticks = ticks;
207
208 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
209 "AMRR: nrates=%d, initial rate %d",
210 rs->rs_nrates,
211 rate);
212 }
213
214 static void
215 amrr_node_deinit(struct ieee80211_node *ni)
216 {
217 free(ni->ni_rctls, M_80211_RATECTL);
218 }
219
220 static int
221 amrr_update(struct ieee80211_amrr *amrr, struct ieee80211_amrr_node *amn,
222 struct ieee80211_node *ni)
223 {
224 int rix = amn->amn_rix;
225 const struct ieee80211_rateset *rs = NULL;
226
227 KASSERT(is_enough(amn), ("txcnt %d", amn->amn_txcnt));
228
229 /* 11n or not? Pick the right rateset */
230 if (amrr_node_is_11n(ni)) {
231 /* XXX ew */
232 rs = (struct ieee80211_rateset *) &ni->ni_htrates;
233 } else {
234 rs = &ni->ni_rates;
235 }
236
237 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
238 "AMRR: current rate %d, txcnt=%d, retrycnt=%d",
239 rs->rs_rates[rix] & IEEE80211_RATE_VAL,
240 amn->amn_txcnt,
241 amn->amn_retrycnt);
242
243 /*
244 * XXX This is totally bogus for 11n, as although high MCS
245 * rates for each stream may be failing, the next stream
246 * should be checked.
247 *
248 * Eg, if MCS5 is ok but MCS6/7 isn't, and we can go up to
249 * MCS23, we should skip 6/7 and try 8 onwards.
250 */
251 if (is_success(amn)) {
252 amn->amn_success++;
253 if (amn->amn_success >= amn->amn_success_threshold &&
254 rix + 1 < rs->rs_nrates) {
255 amn->amn_recovery = 1;
256 amn->amn_success = 0;
257 rix++;
258 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
259 "AMRR increasing rate %d (txcnt=%d retrycnt=%d)",
260 rs->rs_rates[rix] & IEEE80211_RATE_VAL,
261 amn->amn_txcnt, amn->amn_retrycnt);
262 } else {
263 amn->amn_recovery = 0;
264 }
265 } else if (is_failure(amn)) {
266 amn->amn_success = 0;
267 if (rix > 0) {
268 if (amn->amn_recovery) {
269 amn->amn_success_threshold *= 2;
270 if (amn->amn_success_threshold >
271 amrr->amrr_max_success_threshold)
272 amn->amn_success_threshold =
273 amrr->amrr_max_success_threshold;
274 } else {
275 amn->amn_success_threshold =
276 amrr->amrr_min_success_threshold;
277 }
278 rix--;
279 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
280 "AMRR decreasing rate %d (txcnt=%d retrycnt=%d)",
281 rs->rs_rates[rix] & IEEE80211_RATE_VAL,
282 amn->amn_txcnt, amn->amn_retrycnt);
283 }
284 amn->amn_recovery = 0;
285 }
286
287 /* reset counters */
288 amn->amn_txcnt = 0;
289 amn->amn_retrycnt = 0;
290
291 return rix;
292 }
293
294 /*
295 * Return the rate index to use in sending a data frame.
296 * Update our internal state if it's been long enough.
297 * If the rate changes we also update ni_txrate to match.
298 */
299 static int
300 amrr_rate(struct ieee80211_node *ni, void *arg __unused, uint32_t iarg __unused)
301 {
302 struct ieee80211_amrr_node *amn = ni->ni_rctls;
303 struct ieee80211_amrr *amrr = amn->amn_amrr;
304 const struct ieee80211_rateset *rs = NULL;
305 int rix;
306
307 /* 11n or not? Pick the right rateset */
308 if (amrr_node_is_11n(ni)) {
309 /* XXX ew */
310 rs = (struct ieee80211_rateset *) &ni->ni_htrates;
311 } else {
312 rs = &ni->ni_rates;
313 }
314
315 if (is_enough(amn) && (ticks - amn->amn_ticks) > amrr->amrr_interval) {
316 rix = amrr_update(amrr, amn, ni);
317 if (rix != amn->amn_rix) {
318 /* update public rate */
319 ni->ni_txrate = rs->rs_rates[rix];
320 /* XXX strip basic rate flag from txrate, if non-11n */
321 if (amrr_node_is_11n(ni))
322 ni->ni_txrate |= IEEE80211_RATE_MCS;
323 else
324 ni->ni_txrate &= IEEE80211_RATE_VAL;
325 amn->amn_rix = rix;
326 }
327 amn->amn_ticks = ticks;
328 } else
329 rix = amn->amn_rix;
330 return rix;
331 }
332
333 /*
334 * Update statistics with tx complete status. Ok is non-zero
335 * if the packet is known to be ACK'd. Retries has the number
336 * retransmissions (i.e. xmit attempts - 1).
337 */
338 static void
339 amrr_tx_complete(const struct ieee80211vap *vap,
340 const struct ieee80211_node *ni, int ok,
341 void *arg1, void *arg2 __unused)
342 {
343 struct ieee80211_amrr_node *amn = ni->ni_rctls;
344 int retries = *(int *)arg1;
345
346 amn->amn_txcnt++;
347 if (ok)
348 amn->amn_success++;
349 amn->amn_retrycnt += retries;
350 }
351
352 /*
353 * Set tx count/retry statistics explicitly. Intended for
354 * drivers that poll the device for statistics maintained
355 * in the device.
356 */
357 static void
358 amrr_tx_update(const struct ieee80211vap *vap, const struct ieee80211_node *ni,
359 void *arg1, void *arg2, void *arg3)
360 {
361 struct ieee80211_amrr_node *amn = ni->ni_rctls;
362 int txcnt = *(int *)arg1, success = *(int *)arg2, retrycnt = *(int *)arg3;
363
364 amn->amn_txcnt = txcnt;
365 amn->amn_success = success;
366 amn->amn_retrycnt = retrycnt;
367 }
368
369 static int
370 amrr_sysctl_interval(SYSCTL_HANDLER_ARGS)
371 {
372 struct ieee80211vap *vap = arg1;
373 struct ieee80211_amrr *amrr = vap->iv_rs;
374 int msecs = ticks_to_msecs(amrr->amrr_interval);
375 int error;
376
377 error = sysctl_handle_int(oidp, &msecs, 0, req);
378 if (error || !req->newptr)
379 return error;
380 amrr_setinterval(vap, msecs);
381 return 0;
382 }
383
384 static void
385 amrr_sysctlattach(struct ieee80211vap *vap,
386 struct sysctl_ctx_list *ctx, struct sysctl_oid *tree)
387 {
388 struct ieee80211_amrr *amrr = vap->iv_rs;
389
390 SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
391 "amrr_rate_interval", CTLTYPE_INT | CTLFLAG_RW, vap,
392 0, amrr_sysctl_interval, "I", "amrr operation interval (ms)");
393 /* XXX bounds check values */
394 SYSCTL_ADD_UINT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
395 "amrr_max_sucess_threshold", CTLFLAG_RW,
396 &amrr->amrr_max_success_threshold, 0, "");
397 SYSCTL_ADD_UINT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
398 "amrr_min_sucess_threshold", CTLFLAG_RW,
399 &amrr->amrr_min_success_threshold, 0, "");
400 }
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