1 /* $OpenBSD: ieee80211_amrr.c,v 1.1 2006/06/17 19:07:19 damien Exp $ */
4 * Copyright (c) 2010 Rui Paulo <rpaulo@FreeBSD.org>
6 * Damien Bergamini <damien.bergamini@free.fr>
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.
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.
21 #include <sys/cdefs.h>
22 __FBSDID("$FreeBSD$");
25 * Naive implementation of the Adaptive Multi Rate Retry algorithm:
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
34 #include <sys/param.h>
35 #include <sys/kernel.h>
36 #include <sys/malloc.h>
37 #include <sys/module.h>
39 #include <sys/socket.h>
40 #include <sys/sysctl.h>
43 #include <net/if_var.h>
44 #include <net/if_media.h>
45 #include <net/ethernet.h>
48 #include <netinet/in.h>
49 #include <netinet/if_ether.h>
52 #include <net80211/ieee80211_var.h>
53 #include <net80211/ieee80211_ht.h>
54 #include <net80211/ieee80211_amrr.h>
55 #include <net80211/ieee80211_ratectl.h>
57 #define is_success(amn) \
58 ((amn)->amn_retrycnt < (amn)->amn_txcnt / 10)
59 #define is_failure(amn) \
60 ((amn)->amn_retrycnt > (amn)->amn_txcnt / 3)
61 #define is_enough(amn) \
62 ((amn)->amn_txcnt > 10)
64 static void amrr_setinterval(const struct ieee80211vap *, int);
65 static void amrr_init(struct ieee80211vap *);
66 static void amrr_deinit(struct ieee80211vap *);
67 static void amrr_node_init(struct ieee80211_node *);
68 static void amrr_node_deinit(struct ieee80211_node *);
69 static int amrr_update(struct ieee80211_amrr *,
70 struct ieee80211_amrr_node *, struct ieee80211_node *);
71 static int amrr_rate(struct ieee80211_node *, void *, uint32_t);
72 static void amrr_tx_complete(const struct ieee80211_node *,
73 const struct ieee80211_ratectl_tx_status *);
74 static void amrr_tx_update_cb(void *, struct ieee80211_node *);
75 static void amrr_tx_update(struct ieee80211vap *vap,
76 struct ieee80211_ratectl_tx_stats *);
77 static void amrr_sysctlattach(struct ieee80211vap *,
78 struct sysctl_ctx_list *, struct sysctl_oid *);
79 static void amrr_node_stats(struct ieee80211_node *ni, struct sbuf *s);
81 /* number of references from net80211 layer */
84 static const struct ieee80211_ratectl amrr = {
89 .ir_deinit = amrr_deinit,
90 .ir_node_init = amrr_node_init,
91 .ir_node_deinit = amrr_node_deinit,
93 .ir_tx_complete = amrr_tx_complete,
94 .ir_tx_update = amrr_tx_update,
95 .ir_setinterval = amrr_setinterval,
96 .ir_node_stats = amrr_node_stats,
98 IEEE80211_RATECTL_MODULE(amrr, 1);
99 IEEE80211_RATECTL_ALG(amrr, IEEE80211_RATECTL_AMRR, amrr);
102 amrr_setinterval(const struct ieee80211vap *vap, int msecs)
104 struct ieee80211_amrr *amrr = vap->iv_rs;
109 t = msecs_to_ticks(msecs);
110 amrr->amrr_interval = (t < 1) ? 1 : t;
114 amrr_init(struct ieee80211vap *vap)
116 struct ieee80211_amrr *amrr;
118 KASSERT(vap->iv_rs == NULL, ("%s called multiple times", __func__));
120 nrefs++; /* XXX locking */
121 amrr = vap->iv_rs = IEEE80211_MALLOC(sizeof(struct ieee80211_amrr),
122 M_80211_RATECTL, IEEE80211_M_NOWAIT | IEEE80211_M_ZERO);
124 if_printf(vap->iv_ifp, "couldn't alloc ratectl structure\n");
127 amrr->amrr_min_success_threshold = IEEE80211_AMRR_MIN_SUCCESS_THRESHOLD;
128 amrr->amrr_max_success_threshold = IEEE80211_AMRR_MAX_SUCCESS_THRESHOLD;
129 amrr_setinterval(vap, 500 /* ms */);
130 amrr_sysctlattach(vap, vap->iv_sysctl, vap->iv_oid);
134 amrr_deinit(struct ieee80211vap *vap)
136 IEEE80211_FREE(vap->iv_rs, M_80211_RATECTL);
137 KASSERT(nrefs > 0, ("imbalanced attach/detach"));
138 nrefs--; /* XXX locking */
142 * Return whether 11n rates are possible.
144 * Some 11n devices may return HT information but no HT rates.
145 * Thus, we shouldn't treat them as an 11n node.
148 amrr_node_is_11n(struct ieee80211_node *ni)
151 if (ni->ni_chan == NULL)
153 if (ni->ni_chan == IEEE80211_CHAN_ANYC)
155 if (IEEE80211_IS_CHAN_HT(ni->ni_chan) && ni->ni_htrates.rs_nrates == 0)
157 return (IEEE80211_IS_CHAN_HT(ni->ni_chan));
161 amrr_node_init(struct ieee80211_node *ni)
163 const struct ieee80211_rateset *rs = NULL;
164 struct ieee80211vap *vap = ni->ni_vap;
165 struct ieee80211_amrr *amrr = vap->iv_rs;
166 struct ieee80211_amrr_node *amn;
169 if (ni->ni_rctls == NULL) {
170 ni->ni_rctls = amn = IEEE80211_MALLOC(sizeof(struct ieee80211_amrr_node),
171 M_80211_RATECTL, IEEE80211_M_NOWAIT | IEEE80211_M_ZERO);
173 if_printf(vap->iv_ifp, "couldn't alloc per-node ratectl "
179 amn->amn_amrr = amrr;
180 amn->amn_success = 0;
181 amn->amn_recovery = 0;
182 amn->amn_txcnt = amn->amn_retrycnt = 0;
183 amn->amn_success_threshold = amrr->amrr_min_success_threshold;
185 /* 11n or not? Pick the right rateset */
186 if (amrr_node_is_11n(ni)) {
188 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
189 "%s: 11n node", __func__);
190 rs = (struct ieee80211_rateset *) &ni->ni_htrates;
192 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
193 "%s: non-11n node", __func__);
197 /* Initial rate - lowest */
198 rate = rs->rs_rates[0];
200 /* XXX clear the basic rate flag if it's not 11n */
201 if (! amrr_node_is_11n(ni))
202 rate &= IEEE80211_RATE_VAL;
204 /* pick initial rate from the rateset - HT or otherwise */
205 /* Pick something low that's likely to succeed */
206 for (amn->amn_rix = rs->rs_nrates - 1; amn->amn_rix > 0;
208 /* legacy - anything < 36mbit, stop searching */
209 /* 11n - stop at MCS4 */
210 if (amrr_node_is_11n(ni)) {
211 if ((rs->rs_rates[amn->amn_rix] & 0x1f) < 4)
213 } else if ((rs->rs_rates[amn->amn_rix] & IEEE80211_RATE_VAL) <= 72)
216 rate = rs->rs_rates[amn->amn_rix] & IEEE80211_RATE_VAL;
218 /* if the rate is an 11n rate, ensure the MCS bit is set */
219 if (amrr_node_is_11n(ni))
220 rate |= IEEE80211_RATE_MCS;
222 /* Assign initial rate from the rateset */
223 ni->ni_txrate = rate;
224 amn->amn_ticks = ticks;
226 /* XXX TODO: we really need a rate-to-string method */
227 /* XXX TODO: non-11n rate should be divided by two.. */
228 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
229 "AMRR: nrates=%d, initial rate %s%d",
231 amrr_node_is_11n(ni) ? "MCS " : "",
232 rate & IEEE80211_RATE_VAL);
236 amrr_node_deinit(struct ieee80211_node *ni)
238 IEEE80211_FREE(ni->ni_rctls, M_80211_RATECTL);
242 amrr_update(struct ieee80211_amrr *amrr, struct ieee80211_amrr_node *amn,
243 struct ieee80211_node *ni)
245 int rix = amn->amn_rix;
246 const struct ieee80211_rateset *rs = NULL;
248 KASSERT(is_enough(amn), ("txcnt %d", amn->amn_txcnt));
250 /* 11n or not? Pick the right rateset */
251 if (amrr_node_is_11n(ni)) {
253 rs = (struct ieee80211_rateset *) &ni->ni_htrates;
258 /* XXX TODO: we really need a rate-to-string method */
259 /* XXX TODO: non-11n rate should be divided by two.. */
260 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
261 "AMRR: current rate %d, txcnt=%d, retrycnt=%d",
262 rs->rs_rates[rix] & IEEE80211_RATE_VAL,
267 * XXX This is totally bogus for 11n, as although high MCS
268 * rates for each stream may be failing, the next stream
271 * Eg, if MCS5 is ok but MCS6/7 isn't, and we can go up to
272 * MCS23, we should skip 6/7 and try 8 onwards.
274 if (is_success(amn)) {
276 if (amn->amn_success >= amn->amn_success_threshold &&
277 rix + 1 < rs->rs_nrates) {
278 amn->amn_recovery = 1;
279 amn->amn_success = 0;
281 /* XXX TODO: we really need a rate-to-string method */
282 /* XXX TODO: non-11n rate should be divided by two.. */
283 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
284 "AMRR increasing rate %d (txcnt=%d retrycnt=%d)",
285 rs->rs_rates[rix] & IEEE80211_RATE_VAL,
286 amn->amn_txcnt, amn->amn_retrycnt);
288 amn->amn_recovery = 0;
290 } else if (is_failure(amn)) {
291 amn->amn_success = 0;
293 if (amn->amn_recovery) {
294 amn->amn_success_threshold *= 2;
295 if (amn->amn_success_threshold >
296 amrr->amrr_max_success_threshold)
297 amn->amn_success_threshold =
298 amrr->amrr_max_success_threshold;
300 amn->amn_success_threshold =
301 amrr->amrr_min_success_threshold;
304 /* XXX TODO: we really need a rate-to-string method */
305 /* XXX TODO: non-11n rate should be divided by two.. */
306 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
307 "AMRR decreasing rate %d (txcnt=%d retrycnt=%d)",
308 rs->rs_rates[rix] & IEEE80211_RATE_VAL,
309 amn->amn_txcnt, amn->amn_retrycnt);
311 amn->amn_recovery = 0;
316 amn->amn_retrycnt = 0;
322 * Return the rate index to use in sending a data frame.
323 * Update our internal state if it's been long enough.
324 * If the rate changes we also update ni_txrate to match.
327 amrr_rate(struct ieee80211_node *ni, void *arg __unused, uint32_t iarg __unused)
329 struct ieee80211_amrr_node *amn = ni->ni_rctls;
330 struct ieee80211_amrr *amrr = amn->amn_amrr;
331 const struct ieee80211_rateset *rs = NULL;
334 /* 11n or not? Pick the right rateset */
335 if (amrr_node_is_11n(ni)) {
337 rs = (struct ieee80211_rateset *) &ni->ni_htrates;
342 if (is_enough(amn) && (ticks - amn->amn_ticks) > amrr->amrr_interval) {
343 rix = amrr_update(amrr, amn, ni);
344 if (rix != amn->amn_rix) {
345 /* update public rate */
346 ni->ni_txrate = rs->rs_rates[rix];
347 /* XXX strip basic rate flag from txrate, if non-11n */
348 if (amrr_node_is_11n(ni))
349 ni->ni_txrate |= IEEE80211_RATE_MCS;
351 ni->ni_txrate &= IEEE80211_RATE_VAL;
354 amn->amn_ticks = ticks;
361 * Update statistics with tx complete status. Ok is non-zero
362 * if the packet is known to be ACK'd. Retries has the number
363 * retransmissions (i.e. xmit attempts - 1).
366 amrr_tx_complete(const struct ieee80211_node *ni,
367 const struct ieee80211_ratectl_tx_status *status)
369 struct ieee80211_amrr_node *amn = ni->ni_rctls;
373 if (status->flags & IEEE80211_RATECTL_STATUS_LONG_RETRY)
374 retries = status->long_retries;
377 if (status->status == IEEE80211_RATECTL_TX_SUCCESS)
379 amn->amn_retrycnt += retries;
383 amrr_tx_update_cb(void *arg, struct ieee80211_node *ni)
385 struct ieee80211_ratectl_tx_stats *stats = arg;
386 struct ieee80211_amrr_node *amn = ni->ni_rctls;
387 int txcnt, success, retrycnt;
389 txcnt = stats->nframes;
390 success = stats->nsuccess;
392 if (stats->flags & IEEE80211_RATECTL_TX_STATS_RETRIES)
393 retrycnt = stats->nretries;
395 amn->amn_txcnt += txcnt;
396 amn->amn_success += success;
397 amn->amn_retrycnt += retrycnt;
401 * Set tx count/retry statistics explicitly. Intended for
402 * drivers that poll the device for statistics maintained
406 amrr_tx_update(struct ieee80211vap *vap,
407 struct ieee80211_ratectl_tx_stats *stats)
410 if (stats->flags & IEEE80211_RATECTL_TX_STATS_NODE)
411 amrr_tx_update_cb(stats, stats->ni);
413 ieee80211_iterate_nodes_vap(&vap->iv_ic->ic_sta, vap,
414 amrr_tx_update_cb, stats);
419 amrr_sysctl_interval(SYSCTL_HANDLER_ARGS)
421 struct ieee80211vap *vap = arg1;
422 struct ieee80211_amrr *amrr = vap->iv_rs;
423 int msecs = ticks_to_msecs(amrr->amrr_interval);
426 error = sysctl_handle_int(oidp, &msecs, 0, req);
427 if (error || !req->newptr)
429 amrr_setinterval(vap, msecs);
434 amrr_sysctlattach(struct ieee80211vap *vap,
435 struct sysctl_ctx_list *ctx, struct sysctl_oid *tree)
437 struct ieee80211_amrr *amrr = vap->iv_rs;
439 SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
440 "amrr_rate_interval", CTLTYPE_INT | CTLFLAG_RW, vap,
441 0, amrr_sysctl_interval, "I", "amrr operation interval (ms)");
442 /* XXX bounds check values */
443 SYSCTL_ADD_UINT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
444 "amrr_max_sucess_threshold", CTLFLAG_RW,
445 &amrr->amrr_max_success_threshold, 0, "");
446 SYSCTL_ADD_UINT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
447 "amrr_min_sucess_threshold", CTLFLAG_RW,
448 &amrr->amrr_min_success_threshold, 0, "");
452 amrr_node_stats(struct ieee80211_node *ni, struct sbuf *s)
455 struct ieee80211_amrr_node *amn = ni->ni_rctls;
456 struct ieee80211_rateset *rs;
458 /* XXX TODO: check locking? */
460 /* XXX TODO: this should be a method */
461 if (amrr_node_is_11n(ni)) {
462 rs = (struct ieee80211_rateset *) &ni->ni_htrates;
463 rate = rs->rs_rates[amn->amn_rix] & IEEE80211_RATE_VAL;
464 sbuf_printf(s, "rate: MCS %d\n", rate);
467 rate = rs->rs_rates[amn->amn_rix] & IEEE80211_RATE_VAL;
468 sbuf_printf(s, "rate: %d Mbit\n", rate / 2);
471 sbuf_printf(s, "ticks: %d\n", amn->amn_ticks);
472 sbuf_printf(s, "txcnt: %u\n", amn->amn_txcnt);
473 sbuf_printf(s, "success: %u\n", amn->amn_success);
474 sbuf_printf(s, "success_threshold: %u\n", amn->amn_success_threshold);
475 sbuf_printf(s, "recovery: %u\n", amn->amn_recovery);
476 sbuf_printf(s, "retry_cnt: %u\n", amn->amn_retrycnt);