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 ieee80211vap *,
73 const struct ieee80211_node *, int,
75 static void amrr_tx_update(const struct ieee80211vap *vap,
76 const struct ieee80211_node *, void *, void *, void *);
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 amrr = vap->iv_rs = IEEE80211_MALLOC(sizeof(struct ieee80211_amrr),
121 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 ni->ni_rctls = amn = IEEE80211_MALLOC(sizeof(struct ieee80211_amrr_node),
168 M_80211_RATECTL, IEEE80211_M_NOWAIT | IEEE80211_M_ZERO);
170 if_printf(vap->iv_ifp, "couldn't alloc per-node ratectl "
176 amn->amn_amrr = amrr;
177 amn->amn_success = 0;
178 amn->amn_recovery = 0;
179 amn->amn_txcnt = amn->amn_retrycnt = 0;
180 amn->amn_success_threshold = amrr->amrr_min_success_threshold;
182 /* 11n or not? Pick the right rateset */
183 if (amrr_node_is_11n(ni)) {
185 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
186 "%s: 11n node", __func__);
187 rs = (struct ieee80211_rateset *) &ni->ni_htrates;
189 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
190 "%s: non-11n node", __func__);
194 /* Initial rate - lowest */
195 rate = rs->rs_rates[0];
197 /* XXX clear the basic rate flag if it's not 11n */
198 if (! amrr_node_is_11n(ni))
199 rate &= IEEE80211_RATE_VAL;
201 /* pick initial rate from the rateset - HT or otherwise */
202 /* Pick something low that's likely to succeed */
203 for (amn->amn_rix = rs->rs_nrates - 1; amn->amn_rix > 0;
205 /* legacy - anything < 36mbit, stop searching */
206 /* 11n - stop at MCS4 */
207 if (amrr_node_is_11n(ni)) {
208 if ((rs->rs_rates[amn->amn_rix] & 0x1f) < 4)
210 } else if ((rs->rs_rates[amn->amn_rix] & IEEE80211_RATE_VAL) <= 72)
213 rate = rs->rs_rates[amn->amn_rix] & IEEE80211_RATE_VAL;
215 /* if the rate is an 11n rate, ensure the MCS bit is set */
216 if (amrr_node_is_11n(ni))
217 rate |= IEEE80211_RATE_MCS;
219 /* Assign initial rate from the rateset */
220 ni->ni_txrate = rate;
221 amn->amn_ticks = ticks;
223 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
224 "AMRR: nrates=%d, initial rate %d",
230 amrr_node_deinit(struct ieee80211_node *ni)
232 IEEE80211_FREE(ni->ni_rctls, M_80211_RATECTL);
236 amrr_update(struct ieee80211_amrr *amrr, struct ieee80211_amrr_node *amn,
237 struct ieee80211_node *ni)
239 int rix = amn->amn_rix;
240 const struct ieee80211_rateset *rs = NULL;
242 KASSERT(is_enough(amn), ("txcnt %d", amn->amn_txcnt));
244 /* 11n or not? Pick the right rateset */
245 if (amrr_node_is_11n(ni)) {
247 rs = (struct ieee80211_rateset *) &ni->ni_htrates;
252 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
253 "AMRR: current rate %d, txcnt=%d, retrycnt=%d",
254 rs->rs_rates[rix] & IEEE80211_RATE_VAL,
259 * XXX This is totally bogus for 11n, as although high MCS
260 * rates for each stream may be failing, the next stream
263 * Eg, if MCS5 is ok but MCS6/7 isn't, and we can go up to
264 * MCS23, we should skip 6/7 and try 8 onwards.
266 if (is_success(amn)) {
268 if (amn->amn_success >= amn->amn_success_threshold &&
269 rix + 1 < rs->rs_nrates) {
270 amn->amn_recovery = 1;
271 amn->amn_success = 0;
273 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
274 "AMRR increasing rate %d (txcnt=%d retrycnt=%d)",
275 rs->rs_rates[rix] & IEEE80211_RATE_VAL,
276 amn->amn_txcnt, amn->amn_retrycnt);
278 amn->amn_recovery = 0;
280 } else if (is_failure(amn)) {
281 amn->amn_success = 0;
283 if (amn->amn_recovery) {
284 amn->amn_success_threshold *= 2;
285 if (amn->amn_success_threshold >
286 amrr->amrr_max_success_threshold)
287 amn->amn_success_threshold =
288 amrr->amrr_max_success_threshold;
290 amn->amn_success_threshold =
291 amrr->amrr_min_success_threshold;
294 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
295 "AMRR decreasing rate %d (txcnt=%d retrycnt=%d)",
296 rs->rs_rates[rix] & IEEE80211_RATE_VAL,
297 amn->amn_txcnt, amn->amn_retrycnt);
299 amn->amn_recovery = 0;
304 amn->amn_retrycnt = 0;
310 * Return the rate index to use in sending a data frame.
311 * Update our internal state if it's been long enough.
312 * If the rate changes we also update ni_txrate to match.
315 amrr_rate(struct ieee80211_node *ni, void *arg __unused, uint32_t iarg __unused)
317 struct ieee80211_amrr_node *amn = ni->ni_rctls;
318 struct ieee80211_amrr *amrr = amn->amn_amrr;
319 const struct ieee80211_rateset *rs = NULL;
322 /* 11n or not? Pick the right rateset */
323 if (amrr_node_is_11n(ni)) {
325 rs = (struct ieee80211_rateset *) &ni->ni_htrates;
330 if (is_enough(amn) && (ticks - amn->amn_ticks) > amrr->amrr_interval) {
331 rix = amrr_update(amrr, amn, ni);
332 if (rix != amn->amn_rix) {
333 /* update public rate */
334 ni->ni_txrate = rs->rs_rates[rix];
335 /* XXX strip basic rate flag from txrate, if non-11n */
336 if (amrr_node_is_11n(ni))
337 ni->ni_txrate |= IEEE80211_RATE_MCS;
339 ni->ni_txrate &= IEEE80211_RATE_VAL;
342 amn->amn_ticks = ticks;
349 * Update statistics with tx complete status. Ok is non-zero
350 * if the packet is known to be ACK'd. Retries has the number
351 * retransmissions (i.e. xmit attempts - 1).
354 amrr_tx_complete(const struct ieee80211vap *vap,
355 const struct ieee80211_node *ni, int ok,
356 void *arg1, void *arg2 __unused)
358 struct ieee80211_amrr_node *amn = ni->ni_rctls;
359 int retries = *(int *)arg1;
364 amn->amn_retrycnt += retries;
368 * Set tx count/retry statistics explicitly. Intended for
369 * drivers that poll the device for statistics maintained
373 amrr_tx_update(const struct ieee80211vap *vap, const struct ieee80211_node *ni,
374 void *arg1, void *arg2, void *arg3)
376 struct ieee80211_amrr_node *amn = ni->ni_rctls;
377 int txcnt = *(int *)arg1, success = *(int *)arg2, retrycnt = *(int *)arg3;
379 amn->amn_txcnt = txcnt;
380 amn->amn_success = success;
381 amn->amn_retrycnt = retrycnt;
385 amrr_sysctl_interval(SYSCTL_HANDLER_ARGS)
387 struct ieee80211vap *vap = arg1;
388 struct ieee80211_amrr *amrr = vap->iv_rs;
389 int msecs = ticks_to_msecs(amrr->amrr_interval);
392 error = sysctl_handle_int(oidp, &msecs, 0, req);
393 if (error || !req->newptr)
395 amrr_setinterval(vap, msecs);
400 amrr_sysctlattach(struct ieee80211vap *vap,
401 struct sysctl_ctx_list *ctx, struct sysctl_oid *tree)
403 struct ieee80211_amrr *amrr = vap->iv_rs;
405 SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
406 "amrr_rate_interval", CTLTYPE_INT | CTLFLAG_RW, vap,
407 0, amrr_sysctl_interval, "I", "amrr operation interval (ms)");
408 /* XXX bounds check values */
409 SYSCTL_ADD_UINT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
410 "amrr_max_sucess_threshold", CTLFLAG_RW,
411 &amrr->amrr_max_success_threshold, 0, "");
412 SYSCTL_ADD_UINT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
413 "amrr_min_sucess_threshold", CTLFLAG_RW,
414 &amrr->amrr_min_success_threshold, 0, "");
418 amrr_node_stats(struct ieee80211_node *ni, struct sbuf *s)
421 struct ieee80211_amrr_node *amn = ni->ni_rctls;
422 struct ieee80211_rateset *rs;
424 /* XXX TODO: check locking? */
426 /* XXX TODO: this should be a method */
427 if (amrr_node_is_11n(ni)) {
428 rs = (struct ieee80211_rateset *) &ni->ni_htrates;
429 rate = rs->rs_rates[amn->amn_rix] & IEEE80211_RATE_VAL;
430 sbuf_printf(s, "rate: MCS %d\n", rate);
433 rate = rs->rs_rates[amn->amn_rix] & IEEE80211_RATE_VAL;
434 sbuf_printf(s, "rate: %d Mbit\n", rate / 2);
437 sbuf_printf(s, "ticks: %d\n", amn->amn_ticks);
438 sbuf_printf(s, "txcnt: %u\n", amn->amn_txcnt);
439 sbuf_printf(s, "success: %u\n", amn->amn_success);
440 sbuf_printf(s, "success_threshold: %u\n", amn->amn_success_threshold);
441 sbuf_printf(s, "recovery: %u\n", amn->amn_recovery);
442 sbuf_printf(s, "retry_cnt: %u\n", amn->amn_retrycnt);