1 /* $NetBSD: ieee80211_rssadapt.c,v 1.21 2016/09/27 20:20:06 christos Exp $ */
2 /*-
3 * Copyright (c) 2003, 2004 David Young. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or
6 * without modification, are permitted provided that the following
7 * conditions are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above
11 * copyright notice, this list of conditions and the following
12 * disclaimer in the documentation and/or other materials provided
13 * with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY David Young ``AS IS'' AND ANY
16 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
17 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
18 * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL David
19 * Young BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
20 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
21 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
23 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
26 * OF SUCH DAMAGE.
27 */
28
29 #include <sys/cdefs.h>
30 #ifdef __NetBSD__
31 __KERNEL_RCSID(0, "$NetBSD: ieee80211_rssadapt.c,v 1.21 2016/09/27 20:20:06 christos Exp $");
32 #endif
33
34 #include <sys/param.h>
35 #include <sys/types.h>
36 #include <sys/kernel.h> /* for hz */
37 #include <sys/sysctl.h>
38
39 #include <net/if.h>
40 #include <net/if_media.h>
41 #include <net/if_ether.h>
42
43 #include <net80211/ieee80211_netbsd.h>
44 #include <net80211/ieee80211_var.h>
45 #include <net80211/ieee80211.h>
46 #include <net80211/ieee80211_rssadapt.h>
47
48 #ifdef interpolate
49 #undef interpolate
50 #endif
51 #define interpolate(parm, old, new) ((parm##_old * (old) + \
52 (parm##_denom - parm##_old) * (new)) / \
53 parm##_denom)
54
55 #ifdef IEEE80211_DEBUG
56 static struct timeval lastrateadapt; /* time of last rate adaptation msg */
57 static int currssadaptps = 0; /* rate-adaptation msgs this second */
58 static int ieee80211_adaptrate = 4; /* rate-adaptation max msgs/sec */
59
60 #define RSSADAPT_DO_PRINT() \
61 ((ieee80211_rssadapt_debug > 0) && \
62 ppsratecheck(&lastrateadapt, &currssadaptps, ieee80211_adaptrate))
63 #define RSSADAPT_PRINTF(X) \
64 if (RSSADAPT_DO_PRINT()) \
65 printf X
66
67 int ieee80211_rssadapt_debug = 0;
68
69 #else
70 #define RSSADAPT_DO_PRINT() (0)
71 #define RSSADAPT_PRINTF(X)
72 #endif
73
74 static struct ieee80211_rssadapt_expavgctl master_expavgctl = {
75 .rc_decay_denom = 16,
76 .rc_decay_old = 15,
77 .rc_thresh_denom = 8,
78 .rc_thresh_old = 4,
79 .rc_avgrssi_denom = 8,
80 .rc_avgrssi_old = 4
81 };
82
83 #ifdef __NetBSD__
84 #ifdef IEEE80211_DEBUG
85 /* TBD factor with sysctl_ath_verify, sysctl_ieee80211_verify. */
86 static int
sysctl_ieee80211_rssadapt_debug(SYSCTLFN_ARGS)87 sysctl_ieee80211_rssadapt_debug(SYSCTLFN_ARGS)
88 {
89 int error, t;
90 struct sysctlnode node;
91
92 node = *rnode;
93 t = *(int*)rnode->sysctl_data;
94 node.sysctl_data = &t;
95 error = sysctl_lookup(SYSCTLFN_CALL(&node));
96 if (error || newp == NULL)
97 return (error);
98
99 if (t < 0 || t > 2)
100 return (EINVAL);
101 *(int*)rnode->sysctl_data = t;
102
103 return (0);
104 }
105 #endif /* IEEE80211_DEBUG */
106
107 /* TBD factor with sysctl_ath_verify, sysctl_ieee80211_verify. */
108 static int
sysctl_ieee80211_rssadapt_expavgctl(SYSCTLFN_ARGS)109 sysctl_ieee80211_rssadapt_expavgctl(SYSCTLFN_ARGS)
110 {
111 struct ieee80211_rssadapt_expavgctl rc;
112 int error;
113 struct sysctlnode node;
114
115 node = *rnode;
116 rc = *(struct ieee80211_rssadapt_expavgctl *)rnode->sysctl_data;
117 node.sysctl_data = &rc;
118 error = sysctl_lookup(SYSCTLFN_CALL(&node));
119 if (error || newp == NULL)
120 return (error);
121
122 if (/* rc.rc_decay_old < 0 || */
123 rc.rc_decay_denom < rc.rc_decay_old)
124 return (EINVAL);
125
126 if (/* rc.rc_thresh_old < 0 || */
127 rc.rc_thresh_denom < rc.rc_thresh_old)
128 return (EINVAL);
129
130 if (/* rc.rc_avgrssi_old < 0 || */
131 rc.rc_avgrssi_denom < rc.rc_avgrssi_old)
132 return (EINVAL);
133
134 *(struct ieee80211_rssadapt_expavgctl *)rnode->sysctl_data = rc;
135
136 return (0);
137 }
138
139 /*
140 * Setup sysctl(3) MIB, net.ieee80211.*
141 *
142 * TBD condition CTLFLAG_PERMANENT on being a module or not
143 */
144 void
ieee80211_rssadapt_sysctl_setup(struct sysctllog ** clog)145 ieee80211_rssadapt_sysctl_setup(struct sysctllog **clog)
146 {
147 int rc;
148 const struct sysctlnode *node;
149
150 if ((rc = sysctl_createv(clog, 0, NULL, &node,
151 CTLFLAG_PERMANENT, CTLTYPE_NODE, "link", NULL,
152 NULL, 0, NULL, 0, CTL_NET, PF_LINK, CTL_EOL)) != 0)
153 goto err;
154
155 if ((rc = sysctl_createv(clog, 0, &node, &node,
156 CTLFLAG_PERMANENT, CTLTYPE_NODE, "ieee80211", NULL,
157 NULL, 0, NULL, 0, CTL_CREATE, CTL_EOL)) != 0)
158 goto err;
159
160 if ((rc = sysctl_createv(clog, 0, &node, &node,
161 CTLFLAG_PERMANENT, CTLTYPE_NODE, "rssadapt",
162 SYSCTL_DESCR("Received Signal Strength adaptation controls"),
163 NULL, 0, NULL, 0, CTL_CREATE, CTL_EOL)) != 0)
164 goto err;
165
166 #ifdef IEEE80211_DEBUG
167 /* control debugging printfs */
168 if ((rc = sysctl_createv(clog, 0, &node, NULL,
169 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, CTLTYPE_INT, "debug",
170 SYSCTL_DESCR("Enable RSS adaptation debugging output"),
171 sysctl_ieee80211_rssadapt_debug, 0, &ieee80211_rssadapt_debug, 0,
172 CTL_CREATE, CTL_EOL)) != 0)
173 goto err;
174 #endif /* IEEE80211_DEBUG */
175
176 /* control rate of decay for exponential averages */
177 if ((rc = sysctl_createv(clog, 0, &node, NULL,
178 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, CTLTYPE_STRUCT,
179 "expavgctl", SYSCTL_DESCR("RSS exponential averaging control"),
180 sysctl_ieee80211_rssadapt_expavgctl, 0,
181 &master_expavgctl, sizeof(master_expavgctl), CTL_CREATE,
182 CTL_EOL)) != 0)
183 goto err;
184
185 return;
186 err:
187 printf("%s: sysctl_createv failed (rc = %d)\n", __func__, rc);
188 }
189 #endif /* __NetBSD__ */
190
191 int
ieee80211_rssadapt_choose(struct ieee80211_rssadapt * ra,struct ieee80211_rateset * rs,struct ieee80211_frame * wh,u_int len,int fixed_rate,const char * dvname,int do_not_adapt)192 ieee80211_rssadapt_choose(struct ieee80211_rssadapt *ra,
193 struct ieee80211_rateset *rs, struct ieee80211_frame *wh, u_int len,
194 int fixed_rate, const char *dvname, int do_not_adapt)
195 {
196 u_int16_t (*thrs)[IEEE80211_RATE_SIZE];
197 int flags = 0, i, rateidx = 0, thridx, top;
198
199 if ((wh->i_fc[0] & IEEE80211_FC0_TYPE_MASK) == IEEE80211_FC0_TYPE_CTL)
200 flags |= IEEE80211_RATE_BASIC;
201
202 for (i = 0, top = IEEE80211_RSSADAPT_BKT0;
203 i < IEEE80211_RSSADAPT_BKTS;
204 i++, top <<= IEEE80211_RSSADAPT_BKTPOWER) {
205 thridx = i;
206 if (len <= top)
207 break;
208 }
209
210 thrs = &ra->ra_rate_thresh[thridx];
211
212 if (fixed_rate != -1) {
213 if ((rs->rs_rates[fixed_rate] & flags) == flags) {
214 rateidx = fixed_rate;
215 goto out;
216 }
217 flags |= IEEE80211_RATE_BASIC;
218 i = fixed_rate;
219 } else
220 i = rs->rs_nrates;
221
222 while (--i >= 0) {
223 rateidx = i;
224 if ((rs->rs_rates[i] & flags) != flags)
225 continue;
226 if (do_not_adapt)
227 break;
228 if ((*thrs)[i] < ra->ra_avg_rssi)
229 break;
230 }
231
232 out:
233 #ifdef IEEE80211_DEBUG
234 if (ieee80211_rssadapt_debug && dvname != NULL) {
235 printf("%s: dst %s threshold[%d, %d.%d] %d < %d\n",
236 dvname, ether_sprintf(wh->i_addr1), len,
237 (rs->rs_rates[rateidx] & IEEE80211_RATE_VAL) / 2,
238 (rs->rs_rates[rateidx] & IEEE80211_RATE_VAL) * 5 % 10,
239 (*thrs)[rateidx], ra->ra_avg_rssi);
240 }
241 #endif /* IEEE80211_DEBUG */
242 return rateidx;
243 }
244
245 void
ieee80211_rssadapt_updatestats(struct ieee80211_rssadapt * ra)246 ieee80211_rssadapt_updatestats(struct ieee80211_rssadapt *ra)
247 {
248 long interval;
249
250 ra->ra_pktrate =
251 (ra->ra_pktrate + 10 * (ra->ra_nfail + ra->ra_nok)) / 2;
252 ra->ra_nfail = ra->ra_nok = 0;
253
254 /* a node is eligible for its rate to be raised every 1/10 to 10
255 * seconds, more eligible in proportion to recent packet rates.
256 */
257 interval = MAX(100000, 10000000 / MAX(1, 10 * ra->ra_pktrate));
258 ra->ra_raise_interval.tv_sec = interval / (1000 * 1000);
259 ra->ra_raise_interval.tv_usec = interval % (1000 * 1000);
260 }
261
262 void
ieee80211_rssadapt_input(struct ieee80211com * ic,struct ieee80211_node * ni,struct ieee80211_rssadapt * ra,int rssi)263 ieee80211_rssadapt_input(struct ieee80211com *ic, struct ieee80211_node *ni,
264 struct ieee80211_rssadapt *ra, int rssi)
265 {
266 #ifdef IEEE80211_DEBUG
267 int last_avg_rssi = ra->ra_avg_rssi;
268 #endif
269
270 ra->ra_avg_rssi = interpolate(master_expavgctl.rc_avgrssi,
271 ra->ra_avg_rssi, (rssi << 8));
272
273 RSSADAPT_PRINTF(("%s: src %s rssi %d avg %d -> %d\n",
274 ic->ic_ifp->if_xname, ether_sprintf(ni->ni_macaddr),
275 rssi, last_avg_rssi, ra->ra_avg_rssi));
276 }
277
278 /*
279 * Adapt the data rate to suit the conditions. When a transmitted
280 * packet is dropped after IEEE80211_RSSADAPT_RETRY_LIMIT retransmissions,
281 * raise the RSS threshold for transmitting packets of similar length at
282 * the same data rate.
283 */
284 void
ieee80211_rssadapt_lower_rate(struct ieee80211com * ic,struct ieee80211_node * ni,struct ieee80211_rssadapt * ra,struct ieee80211_rssdesc * id)285 ieee80211_rssadapt_lower_rate(struct ieee80211com *ic,
286 struct ieee80211_node *ni, struct ieee80211_rssadapt *ra,
287 struct ieee80211_rssdesc *id)
288 {
289 struct ieee80211_rateset *rs = &ni->ni_rates;
290 u_int16_t last_thr;
291 u_int i, thridx, top;
292
293 ra->ra_nfail++;
294
295 if (id->id_rateidx >= rs->rs_nrates) {
296 RSSADAPT_PRINTF(("ieee80211_rssadapt_lower_rate: "
297 "%s rate #%d > #%d out of bounds\n",
298 ether_sprintf(ni->ni_macaddr), id->id_rateidx,
299 rs->rs_nrates - 1));
300 return;
301 }
302
303 for (i = 0, top = IEEE80211_RSSADAPT_BKT0;
304 i < IEEE80211_RSSADAPT_BKTS;
305 i++, top <<= IEEE80211_RSSADAPT_BKTPOWER) {
306 thridx = i;
307 if (id->id_len <= top)
308 break;
309 }
310
311 last_thr = ra->ra_rate_thresh[thridx][id->id_rateidx];
312 ra->ra_rate_thresh[thridx][id->id_rateidx] =
313 interpolate(master_expavgctl.rc_thresh, last_thr,
314 (id->id_rssi << 8));
315
316 RSSADAPT_PRINTF(("%s: dst %s rssi %d threshold[%d, %d.%d] %d -> %d\n",
317 ic->ic_ifp->if_xname, ether_sprintf(ni->ni_macaddr),
318 id->id_rssi, id->id_len,
319 (rs->rs_rates[id->id_rateidx] & IEEE80211_RATE_VAL) / 2,
320 (rs->rs_rates[id->id_rateidx] & IEEE80211_RATE_VAL) * 5 % 10,
321 last_thr, ra->ra_rate_thresh[thridx][id->id_rateidx]));
322 }
323
324 void
ieee80211_rssadapt_raise_rate(struct ieee80211com * ic,struct ieee80211_rssadapt * ra,struct ieee80211_rssdesc * id)325 ieee80211_rssadapt_raise_rate(struct ieee80211com *ic,
326 struct ieee80211_rssadapt *ra, struct ieee80211_rssdesc *id)
327 {
328 u_int16_t (*thrs)[IEEE80211_RATE_SIZE], newthr, oldthr;
329 struct ieee80211_node *ni = id->id_node;
330 struct ieee80211_rateset *rs = &ni->ni_rates;
331 int i, rate, top;
332 #ifdef IEEE80211_DEBUG
333 int j;
334 #endif
335
336 ra->ra_nok++;
337
338 if (!ratecheck(&ra->ra_last_raise, &ra->ra_raise_interval))
339 return;
340
341 for (i = 0, top = IEEE80211_RSSADAPT_BKT0;
342 i < IEEE80211_RSSADAPT_BKTS;
343 i++, top <<= IEEE80211_RSSADAPT_BKTPOWER) {
344 thrs = &ra->ra_rate_thresh[i];
345 if (id->id_len <= top)
346 break;
347 }
348
349 if (id->id_rateidx + 1 < rs->rs_nrates &&
350 (*thrs)[id->id_rateidx + 1] > (*thrs)[id->id_rateidx]) {
351 rate = (rs->rs_rates[id->id_rateidx + 1] & IEEE80211_RATE_VAL);
352
353 __USE(rate);
354 RSSADAPT_PRINTF(("%s: threshold[%d, %d.%d] decay %d ",
355 ic->ic_ifp->if_xname,
356 IEEE80211_RSSADAPT_BKT0 << (IEEE80211_RSSADAPT_BKTPOWER* i),
357 rate / 2, rate * 5 % 10, (*thrs)[id->id_rateidx + 1]));
358 oldthr = (*thrs)[id->id_rateidx + 1];
359 if ((*thrs)[id->id_rateidx] == 0)
360 newthr = ra->ra_avg_rssi;
361 else
362 newthr = (*thrs)[id->id_rateidx];
363 (*thrs)[id->id_rateidx + 1] =
364 interpolate(master_expavgctl.rc_decay, oldthr, newthr);
365
366 RSSADAPT_PRINTF(("-> %d\n", (*thrs)[id->id_rateidx + 1]));
367 }
368
369 #ifdef IEEE80211_DEBUG
370 if (RSSADAPT_DO_PRINT()) {
371 printf("%s: dst %s thresholds\n", ic->ic_ifp->if_xname,
372 ether_sprintf(ni->ni_macaddr));
373 for (i = 0; i < IEEE80211_RSSADAPT_BKTS; i++) {
374 printf("%d-byte", IEEE80211_RSSADAPT_BKT0 << (IEEE80211_RSSADAPT_BKTPOWER * i));
375 for (j = 0; j < rs->rs_nrates; j++) {
376 rate = (rs->rs_rates[j] & IEEE80211_RATE_VAL);
377 printf(", T[%d.%d] = %d", rate / 2,
378 rate * 5 % 10, ra->ra_rate_thresh[i][j]);
379 }
380 printf("\n");
381 }
382 }
383 #endif /* IEEE80211_DEBUG */
384 }
385