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>
47 #include <netproto/802_11/ieee80211_var.h>
48 #include <netproto/802_11/ieee80211_ht.h>
49 #include <netproto/802_11/ieee80211_amrr.h>
50 #include <netproto/802_11/ieee80211_ratectl.h>
52 #define is_success(amn) \
53 ((amn)->amn_retrycnt < (amn)->amn_txcnt / 10)
54 #define is_failure(amn) \
55 ((amn)->amn_retrycnt > (amn)->amn_txcnt / 3)
56 #define is_enough(amn) \
57 ((amn)->amn_txcnt > 10)
59 static void amrr_setinterval(const struct ieee80211vap *, int);
60 static void amrr_init(struct ieee80211vap *);
61 static void amrr_deinit(struct ieee80211vap *);
62 static void amrr_node_init(struct ieee80211_node *);
63 static void amrr_node_deinit(struct ieee80211_node *);
64 static int amrr_update(struct ieee80211_amrr *,
65 struct ieee80211_amrr_node *, struct ieee80211_node *);
66 static int amrr_rate(struct ieee80211_node *, void *, uint32_t);
67 static void amrr_tx_complete(const struct ieee80211vap *,
68 const struct ieee80211_node *, int,
70 static void amrr_tx_update(const struct ieee80211vap *vap,
71 const struct ieee80211_node *, void *, void *, void *);
72 static void amrr_sysctlattach(struct ieee80211vap *,
73 struct sysctl_ctx_list *, struct sysctl_oid *);
74 static void amrr_node_stats(struct ieee80211_node *ni, struct sbuf *s);
76 /* number of references from net80211 layer */
79 static const struct ieee80211_ratectl amrr = {
84 .ir_deinit = amrr_deinit,
85 .ir_node_init = amrr_node_init,
86 .ir_node_deinit = amrr_node_deinit,
88 .ir_tx_complete = amrr_tx_complete,
89 .ir_tx_update = amrr_tx_update,
90 .ir_setinterval = amrr_setinterval,
91 .ir_node_stats = amrr_node_stats,
93 IEEE80211_RATECTL_MODULE(amrr, 1);
94 IEEE80211_RATECTL_ALG(amrr, IEEE80211_RATECTL_AMRR, amrr);
97 amrr_setinterval(const struct ieee80211vap *vap, int msecs)
99 struct ieee80211_amrr *amrr = vap->iv_rs;
104 t = msecs_to_ticks(msecs);
105 amrr->amrr_interval = (t < 1) ? 1 : t;
109 amrr_init(struct ieee80211vap *vap)
111 struct ieee80211_amrr *amrr;
113 KASSERT(vap->iv_rs == NULL, ("%s called multiple times", __func__));
115 #if defined(__DragonFly__)
116 amrr = vap->iv_rs = kmalloc(sizeof(struct ieee80211_amrr),
117 M_80211_RATECTL, M_INTWAIT|M_ZERO);
119 amrr = vap->iv_rs = IEEE80211_MALLOC(sizeof(struct ieee80211_amrr),
120 M_80211_RATECTL, IEEE80211_M_NOWAIT | IEEE80211_M_ZERO);
123 if_printf(vap->iv_ifp, "couldn't alloc ratectl structure\n");
126 amrr->amrr_min_success_threshold = IEEE80211_AMRR_MIN_SUCCESS_THRESHOLD;
127 amrr->amrr_max_success_threshold = IEEE80211_AMRR_MAX_SUCCESS_THRESHOLD;
128 amrr_setinterval(vap, 500 /* ms */);
129 amrr_sysctlattach(vap, vap->iv_sysctl, vap->iv_oid);
133 amrr_deinit(struct ieee80211vap *vap)
135 IEEE80211_FREE(vap->iv_rs, M_80211_RATECTL);
139 * Return whether 11n rates are possible.
141 * Some 11n devices may return HT information but no HT rates.
142 * Thus, we shouldn't treat them as an 11n node.
145 amrr_node_is_11n(struct ieee80211_node *ni)
148 if (ni->ni_chan == NULL)
150 if (ni->ni_chan == IEEE80211_CHAN_ANYC)
152 if (IEEE80211_IS_CHAN_HT(ni->ni_chan) && ni->ni_htrates.rs_nrates == 0)
154 return (IEEE80211_IS_CHAN_HT(ni->ni_chan));
158 amrr_node_init(struct ieee80211_node *ni)
160 const struct ieee80211_rateset *rs = NULL;
161 struct ieee80211vap *vap = ni->ni_vap;
162 struct ieee80211_amrr *amrr = vap->iv_rs;
163 struct ieee80211_amrr_node *amn;
166 if (ni->ni_rctls == NULL) {
167 #if defined(__DragonFly__)
168 ni->ni_rctls = amn = kmalloc(sizeof(struct ieee80211_amrr_node),
169 M_80211_RATECTL, M_INTWAIT|M_ZERO);
171 ni->ni_rctls = amn = IEEE80211_MALLOC(sizeof(struct ieee80211_amrr_node),
172 M_80211_RATECTL, IEEE80211_M_NOWAIT | IEEE80211_M_ZERO);
175 if_printf(vap->iv_ifp, "couldn't alloc per-node ratectl "
181 amn->amn_amrr = amrr;
182 amn->amn_success = 0;
183 amn->amn_recovery = 0;
184 amn->amn_txcnt = amn->amn_retrycnt = 0;
185 amn->amn_success_threshold = amrr->amrr_min_success_threshold;
187 /* 11n or not? Pick the right rateset */
188 if (amrr_node_is_11n(ni)) {
190 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
191 "%s: 11n node", __func__);
192 rs = (struct ieee80211_rateset *) &ni->ni_htrates;
194 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
195 "%s: non-11n node", __func__);
199 /* Initial rate - lowest */
200 rate = rs->rs_rates[0];
202 /* XXX clear the basic rate flag if it's not 11n */
203 if (! amrr_node_is_11n(ni))
204 rate &= IEEE80211_RATE_VAL;
206 /* pick initial rate from the rateset - HT or otherwise */
207 /* Pick something low that's likely to succeed */
208 for (amn->amn_rix = rs->rs_nrates - 1; amn->amn_rix > 0;
210 /* legacy - anything < 36mbit, stop searching */
211 /* 11n - stop at MCS4 */
212 if (amrr_node_is_11n(ni)) {
213 if ((rs->rs_rates[amn->amn_rix] & 0x1f) < 4)
215 } else if ((rs->rs_rates[amn->amn_rix] & IEEE80211_RATE_VAL) <= 72)
218 rate = rs->rs_rates[amn->amn_rix] & IEEE80211_RATE_VAL;
220 /* if the rate is an 11n rate, ensure the MCS bit is set */
221 if (amrr_node_is_11n(ni))
222 rate |= IEEE80211_RATE_MCS;
224 /* Assign initial rate from the rateset */
225 ni->ni_txrate = rate;
226 amn->amn_ticks = ticks;
228 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
229 "AMRR: nrates=%d, initial rate %d",
235 amrr_node_deinit(struct ieee80211_node *ni)
237 IEEE80211_FREE(ni->ni_rctls, M_80211_RATECTL);
241 amrr_update(struct ieee80211_amrr *amrr, struct ieee80211_amrr_node *amn,
242 struct ieee80211_node *ni)
244 int rix = amn->amn_rix;
245 const struct ieee80211_rateset *rs = NULL;
247 KASSERT(is_enough(amn), ("txcnt %d", amn->amn_txcnt));
249 /* 11n or not? Pick the right rateset */
250 if (amrr_node_is_11n(ni)) {
252 rs = (struct ieee80211_rateset *) &ni->ni_htrates;
257 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
258 "AMRR: current rate %d, txcnt=%d, retrycnt=%d",
259 rs->rs_rates[rix] & IEEE80211_RATE_VAL,
264 * XXX This is totally bogus for 11n, as although high MCS
265 * rates for each stream may be failing, the next stream
268 * Eg, if MCS5 is ok but MCS6/7 isn't, and we can go up to
269 * MCS23, we should skip 6/7 and try 8 onwards.
271 if (is_success(amn)) {
273 if (amn->amn_success >= amn->amn_success_threshold &&
274 rix + 1 < rs->rs_nrates) {
275 amn->amn_recovery = 1;
276 amn->amn_success = 0;
278 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
279 "AMRR increasing rate %d (txcnt=%d retrycnt=%d)",
280 rs->rs_rates[rix] & IEEE80211_RATE_VAL,
281 amn->amn_txcnt, amn->amn_retrycnt);
283 amn->amn_recovery = 0;
285 } else if (is_failure(amn)) {
286 amn->amn_success = 0;
288 if (amn->amn_recovery) {
289 amn->amn_success_threshold *= 2;
290 if (amn->amn_success_threshold >
291 amrr->amrr_max_success_threshold)
292 amn->amn_success_threshold =
293 amrr->amrr_max_success_threshold;
295 amn->amn_success_threshold =
296 amrr->amrr_min_success_threshold;
299 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
300 "AMRR decreasing rate %d (txcnt=%d retrycnt=%d)",
301 rs->rs_rates[rix] & IEEE80211_RATE_VAL,
302 amn->amn_txcnt, amn->amn_retrycnt);
304 amn->amn_recovery = 0;
309 amn->amn_retrycnt = 0;
315 * Return the rate index to use in sending a data frame.
316 * Update our internal state if it's been long enough.
317 * If the rate changes we also update ni_txrate to match.
320 amrr_rate(struct ieee80211_node *ni, void *arg __unused, uint32_t iarg __unused)
322 struct ieee80211_amrr_node *amn = ni->ni_rctls;
323 struct ieee80211_amrr *amrr = amn->amn_amrr;
324 const struct ieee80211_rateset *rs = NULL;
327 /* 11n or not? Pick the right rateset */
328 if (amrr_node_is_11n(ni)) {
330 rs = (struct ieee80211_rateset *) &ni->ni_htrates;
335 if (is_enough(amn) && (ticks - amn->amn_ticks) > amrr->amrr_interval) {
336 rix = amrr_update(amrr, amn, ni);
337 if (rix != amn->amn_rix) {
338 /* update public rate */
339 ni->ni_txrate = rs->rs_rates[rix];
340 /* XXX strip basic rate flag from txrate, if non-11n */
341 if (amrr_node_is_11n(ni))
342 ni->ni_txrate |= IEEE80211_RATE_MCS;
344 ni->ni_txrate &= IEEE80211_RATE_VAL;
347 amn->amn_ticks = ticks;
354 * Update statistics with tx complete status. Ok is non-zero
355 * if the packet is known to be ACK'd. Retries has the number
356 * retransmissions (i.e. xmit attempts - 1).
359 amrr_tx_complete(const struct ieee80211vap *vap,
360 const struct ieee80211_node *ni, int ok,
361 void *arg1, void *arg2 __unused)
363 struct ieee80211_amrr_node *amn = ni->ni_rctls;
364 int retries = *(int *)arg1;
369 amn->amn_retrycnt += retries;
373 * Set tx count/retry statistics explicitly. Intended for
374 * drivers that poll the device for statistics maintained
378 amrr_tx_update(const struct ieee80211vap *vap, const struct ieee80211_node *ni,
379 void *arg1, void *arg2, void *arg3)
381 struct ieee80211_amrr_node *amn = ni->ni_rctls;
382 int txcnt = *(int *)arg1, success = *(int *)arg2, retrycnt = *(int *)arg3;
384 amn->amn_txcnt = txcnt;
385 amn->amn_success = success;
386 amn->amn_retrycnt = retrycnt;
390 amrr_sysctl_interval(SYSCTL_HANDLER_ARGS)
392 struct ieee80211vap *vap = arg1;
393 struct ieee80211_amrr *amrr = vap->iv_rs;
394 int msecs = ticks_to_msecs(amrr->amrr_interval);
397 error = sysctl_handle_int(oidp, &msecs, 0, req);
398 if (error || !req->newptr)
400 amrr_setinterval(vap, msecs);
405 amrr_sysctlattach(struct ieee80211vap *vap,
406 struct sysctl_ctx_list *ctx, struct sysctl_oid *tree)
408 struct ieee80211_amrr *amrr = vap->iv_rs;
410 SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
411 "amrr_rate_interval", CTLTYPE_INT | CTLFLAG_RW, vap,
412 0, amrr_sysctl_interval, "I", "amrr operation interval (ms)");
413 /* XXX bounds check values */
414 SYSCTL_ADD_UINT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
415 "amrr_max_sucess_threshold", CTLFLAG_RW,
416 &amrr->amrr_max_success_threshold, 0, "");
417 SYSCTL_ADD_UINT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
418 "amrr_min_sucess_threshold", CTLFLAG_RW,
419 &amrr->amrr_min_success_threshold, 0, "");
423 amrr_node_stats(struct ieee80211_node *ni, struct sbuf *s)
426 struct ieee80211_amrr_node *amn = ni->ni_rctls;
427 struct ieee80211_rateset *rs;
429 /* XXX TODO: check locking? */
431 /* XXX TODO: this should be a method */
432 if (amrr_node_is_11n(ni)) {
433 rs = (struct ieee80211_rateset *) &ni->ni_htrates;
434 rate = rs->rs_rates[amn->amn_rix] & IEEE80211_RATE_VAL;
435 sbuf_printf(s, "rate: MCS %d\n", rate);
438 rate = rs->rs_rates[amn->amn_rix] & IEEE80211_RATE_VAL;
439 sbuf_printf(s, "rate: %d Mbit\n", rate / 2);
442 sbuf_printf(s, "ticks: %d\n", amn->amn_ticks);
443 sbuf_printf(s, "txcnt: %u\n", amn->amn_txcnt);
444 sbuf_printf(s, "success: %u\n", amn->amn_success);
445 sbuf_printf(s, "success_threshold: %u\n", amn->amn_success_threshold);
446 sbuf_printf(s, "recovery: %u\n", amn->amn_recovery);
447 sbuf_printf(s, "retry_cnt: %u\n", amn->amn_retrycnt);