1 /* $FreeBSD: head/sys/net80211/ieee80211_rssadapt.c 206358 2010-04-07 15:29:13Z rpaulo $ */
2 /* $NetBSD: ieee80211_rssadapt.c,v 1.9 2005/02/26 22:45:09 perry Exp $ */
4 * Copyright (c) 2010 Rui Paulo <rpaulo@FreeBSD.org>
5 * Copyright (c) 2003, 2004 David Young. All rights reserved.
7 * Redistribution and use in source and binary forms, with or
8 * without modification, are permitted provided that the following
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above
13 * copyright notice, this list of conditions and the following
14 * disclaimer in the documentation and/or other materials provided
15 * with the distribution.
16 * 3. The name of David Young may not be used to endorse or promote
17 * products derived from this software without specific prior
20 * THIS SOFTWARE IS PROVIDED BY David Young ``AS IS'' AND ANY
21 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
22 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
23 * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL David
24 * Young BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
25 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
26 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
27 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
28 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
35 #include <sys/param.h>
36 #include <sys/kernel.h>
37 #include <sys/module.h>
38 #include <sys/socket.h>
39 #include <sys/sysctl.h>
42 #include <net/if_media.h>
44 #include <netproto/802_11/ieee80211_var.h>
45 #include <netproto/802_11/ieee80211_rssadapt.h>
46 #include <netproto/802_11/ieee80211_ratectl.h>
48 struct rssadapt_expavgctl {
49 /* RSS threshold decay. */
52 /* RSS threshold update. */
53 u_int rc_thresh_denom;
55 /* RSS average update. */
56 u_int rc_avgrssi_denom;
60 static struct rssadapt_expavgctl master_expavgctl = {
65 .rc_avgrssi_denom = 8,
72 #define interpolate(parm, old, new) ((parm##_old * (old) + \
73 (parm##_denom - parm##_old) * (new)) / \
76 static void rssadapt_setinterval(const struct ieee80211vap *, int);
77 static void rssadapt_init(struct ieee80211vap *);
78 static void rssadapt_deinit(struct ieee80211vap *);
79 static void rssadapt_updatestats(struct ieee80211_rssadapt_node *);
80 static void rssadapt_node_init(struct ieee80211_node *);
81 static void rssadapt_node_deinit(struct ieee80211_node *);
82 static int rssadapt_rate(struct ieee80211_node *, void *, uint32_t);
83 static void rssadapt_lower_rate(struct ieee80211_rssadapt_node *, int, int);
84 static void rssadapt_raise_rate(struct ieee80211_rssadapt_node *,
86 static void rssadapt_tx_complete(const struct ieee80211vap *,
87 const struct ieee80211_node *, int,
89 static void rssadapt_sysctlattach(struct ieee80211vap *,
90 struct sysctl_ctx_list *, struct sysctl_oid *);
92 /* number of references from net80211 layer */
95 static const struct ieee80211_ratectl rssadapt = {
96 .ir_name = "rssadapt",
99 .ir_init = rssadapt_init,
100 .ir_deinit = rssadapt_deinit,
101 .ir_node_init = rssadapt_node_init,
102 .ir_node_deinit = rssadapt_node_deinit,
103 .ir_rate = rssadapt_rate,
104 .ir_tx_complete = rssadapt_tx_complete,
105 .ir_tx_update = NULL,
106 .ir_setinterval = rssadapt_setinterval,
108 IEEE80211_RATECTL_MODULE(rssadapt, 1);
109 IEEE80211_RATECTL_ALG(rssadapt, IEEE80211_RATECTL_RSSADAPT, rssadapt);
112 rssadapt_setinterval(const struct ieee80211vap *vap, int msecs)
114 struct ieee80211_rssadapt *rs = vap->iv_rs;
119 t = msecs_to_ticks(msecs);
120 rs->interval = (t < 1) ? 1 : t;
124 rssadapt_init(struct ieee80211vap *vap)
126 struct ieee80211_rssadapt *rs;
128 KASSERT(vap->iv_rs == NULL, ("%s: iv_rs already initialized",
131 rs = kmalloc(sizeof(struct ieee80211_rssadapt), M_80211_RATECTL,
135 rssadapt_setinterval(vap, 500 /* msecs */);
136 rssadapt_sysctlattach(vap, vap->iv_sysctl, vap->iv_oid);
140 rssadapt_deinit(struct ieee80211vap *vap)
142 kfree(vap->iv_rs, M_80211_RATECTL);
146 rssadapt_updatestats(struct ieee80211_rssadapt_node *ra)
150 ra->ra_pktrate = (ra->ra_pktrate + 10*(ra->ra_nfail + ra->ra_nok))/2;
151 ra->ra_nfail = ra->ra_nok = 0;
154 * A node is eligible for its rate to be raised every 1/10 to 10
155 * seconds, more eligible in proportion to recent packet rates.
157 interval = MAX(10*1000, 10*1000 / MAX(1, 10 * ra->ra_pktrate));
158 ra->ra_raise_interval = msecs_to_ticks(interval);
162 rssadapt_node_init(struct ieee80211_node *ni)
164 struct ieee80211_rssadapt_node *ra;
165 struct ieee80211_rssadapt *rsa = ni->ni_vap->iv_rs;
166 const struct ieee80211_rateset *rs = &ni->ni_rates;
168 ra = kmalloc(sizeof(struct ieee80211_rssadapt_node), M_80211_RATECTL,
173 rssadapt_updatestats(ra);
175 /* pick initial rate */
176 for (ra->ra_rix = rs->rs_nrates - 1;
177 ra->ra_rix > 0 && (rs->rs_rates[ra->ra_rix] & IEEE80211_RATE_VAL) > 72;
180 ni->ni_txrate = rs->rs_rates[ra->ra_rix] & IEEE80211_RATE_VAL;
181 ra->ra_ticks = ticks;
183 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
184 "RSSADAPT initial rate %d", ni->ni_txrate);
188 rssadapt_node_deinit(struct ieee80211_node *ni)
191 kfree(ni->ni_rctls, M_80211_RATECTL);
199 for (i = 0, top = IEEE80211_RSSADAPT_BKT0;
200 i < IEEE80211_RSSADAPT_BKTS;
201 i++, top <<= IEEE80211_RSSADAPT_BKTPOWER) {
210 rssadapt_rate(struct ieee80211_node *ni, void *arg __unused, uint32_t iarg)
212 struct ieee80211_rssadapt_node *ra = ni->ni_rctls;
214 const struct ieee80211_rateset *rs = &ra->ra_rates;
215 uint16_t (*thrs)[IEEE80211_RATE_SIZE];
218 if ((ticks - ra->ra_ticks) > ra->ra_rs->interval) {
219 rssadapt_updatestats(ra);
220 ra->ra_ticks = ticks;
223 thrs = &ra->ra_rate_thresh[bucket(pktlen)];
225 /* XXX this is average rssi, should be using last value */
226 rssi = ni->ni_ic->ic_node_getrssi(ni);
227 for (rix = rs->rs_nrates-1; rix >= 0; rix--)
228 if ((*thrs)[rix] < (rssi << 8))
230 if (rix != ra->ra_rix) {
231 /* update public rate */
232 ni->ni_txrate = ni->ni_rates.rs_rates[rix] & IEEE80211_RATE_VAL;
235 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
236 "RSSADAPT new rate %d (pktlen %d rssi %d)",
237 ni->ni_txrate, pktlen, rssi);
243 * Adapt the data rate to suit the conditions. When a transmitted
244 * packet is dropped after RAL_RSSADAPT_RETRY_LIMIT retransmissions,
245 * raise the RSS threshold for transmitting packets of similar length at
246 * the same data rate.
249 rssadapt_lower_rate(struct ieee80211_rssadapt_node *ra, int pktlen, int rssi)
252 uint16_t (*thrs)[IEEE80211_RATE_SIZE];
255 thrs = &ra->ra_rate_thresh[bucket(pktlen)];
258 last_thr = (*thrs)[rix];
259 (*thrs)[rix] = interpolate(master_expavgctl.rc_thresh,
260 last_thr, (rssi << 8));
262 IEEE80211_DPRINTF(ra->ra_rs->vap, IEEE80211_MSG_RATECTL,
263 "RSSADAPT lower threshold for rate %d (last_thr %d new thr %d rssi %d)\n",
264 ra->ra_rates.rs_rates[rix + 1] & IEEE80211_RATE_VAL,
265 last_thr, (*thrs)[rix], rssi);
269 rssadapt_raise_rate(struct ieee80211_rssadapt_node *ra, int pktlen, int rssi)
271 uint16_t (*thrs)[IEEE80211_RATE_SIZE];
272 uint16_t newthr, oldthr;
275 thrs = &ra->ra_rate_thresh[bucket(pktlen)];
278 if ((*thrs)[rix + 1] > (*thrs)[rix]) {
279 oldthr = (*thrs)[rix + 1];
280 if ((*thrs)[rix] == 0)
281 newthr = (rssi << 8);
283 newthr = (*thrs)[rix];
284 (*thrs)[rix + 1] = interpolate(master_expavgctl.rc_decay,
287 IEEE80211_DPRINTF(ra->ra_rs->vap, IEEE80211_MSG_RATECTL,
288 "RSSADAPT raise threshold for rate %d (oldthr %d newthr %d rssi %d)\n",
289 ra->ra_rates.rs_rates[rix + 1] & IEEE80211_RATE_VAL,
290 oldthr, newthr, rssi);
292 ra->ra_last_raise = ticks;
297 rssadapt_tx_complete(const struct ieee80211vap *vap,
298 const struct ieee80211_node *ni, int success, void *arg1, void *arg2)
300 struct ieee80211_rssadapt_node *ra = ni->ni_rctls;
301 int pktlen = *(int *)arg1, rssi = *(int *)arg2;
305 if ((ra->ra_rix + 1) < ra->ra_rates.rs_nrates &&
306 (ticks - ra->ra_last_raise) >= ra->ra_raise_interval)
307 rssadapt_raise_rate(ra, pktlen, rssi);
310 rssadapt_lower_rate(ra, pktlen, rssi);
315 rssadapt_sysctl_interval(SYSCTL_HANDLER_ARGS)
317 struct ieee80211vap *vap = arg1;
318 struct ieee80211_rssadapt *rs = vap->iv_rs;
319 int msecs = ticks_to_msecs(rs->interval);
322 error = sysctl_handle_int(oidp, &msecs, 0, req);
323 wlan_serialize_enter();
324 if (error == 0 && req->newptr)
325 rssadapt_setinterval(vap, msecs);
326 wlan_serialize_exit();
332 rssadapt_sysctlattach(struct ieee80211vap *vap,
333 struct sysctl_ctx_list *ctx, struct sysctl_oid *tree)
336 SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
337 "rssadapt_rate_interval", CTLTYPE_INT | CTLFLAG_RW, vap,
338 0, rssadapt_sysctl_interval, "I", "rssadapt operation interval (ms)");