ieee80211_rssadapt.c revision 1.6 1 /* $NetBSD: ieee80211_rssadapt.c,v 1.6 2004/05/06 07:11:40 dyoung 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 * 3. The name of David Young may not be used to endorse or promote
15 * products derived from this software without specific prior
16 * written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY David Young ``AS IS'' AND ANY
19 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
20 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
21 * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL David
22 * Young BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
23 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
24 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
26 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
27 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
29 * OF SUCH DAMAGE.
30 */
31
32 #include <sys/param.h>
33 #include <sys/types.h>
34 #include <sys/kernel.h> /* for hz */
35 #include <sys/sysctl.h>
36
37 #include <net/if.h>
38 #include <net/if_media.h>
39 #include <net/if_ether.h>
40
41 #include <net80211/ieee80211_var.h>
42 #include <net80211/ieee80211.h>
43 #include <net80211/ieee80211_compat.h>
44 #include <net80211/ieee80211_rssadapt.h>
45
46 #ifdef interpolate
47 #undef interpolate
48 #endif
49 #define interpolate(parm, old, new) ((parm##_old * (old) + \
50 (parm##_denom - parm##_old) * (new)) / \
51 parm##_denom)
52
53 #ifdef IEEE80211_DEBUG
54 static struct timeval lastrateadapt; /* time of last rate adaptation msg */
55 static int currssadaptps = 0; /* rate-adaptation msgs this second */
56 static int ieee80211_adaptrate = 4; /* rate-adaptation max msgs/sec */
57
58 #define RSSADAPT_DO_PRINT() \
59 ((ieee80211_rssadapt_debug > 0) && \
60 ppsratecheck(&lastrateadapt, &currssadaptps, ieee80211_adaptrate))
61 #define RSSADAPT_PRINTF(X) \
62 if (RSSADAPT_DO_PRINT()) \
63 printf X
64
65 int ieee80211_rssadapt_debug = 0;
66
67 #else
68 #define RSSADAPT_DO_PRINT() (0)
69 #define RSSADAPT_PRINTF(X)
70 #endif
71
72 static struct ieee80211_rssadapt_expavgctl master_expavgctl = {
73 rc_decay_denom : 16,
74 rc_decay_old : 15,
75 rc_thresh_denom : 8,
76 rc_thresh_old : 4,
77 rc_avgrssi_denom : 8,
78 rc_avgrssi_old : 4
79 };
80
81 #ifdef __NetBSD__
82 #ifdef IEEE80211_DEBUG
83 /* TBD factor with sysctl_ath_verify, sysctl_ieee80211_verify. */
84 static int
85 sysctl_ieee80211_rssadapt_debug(SYSCTLFN_ARGS)
86 {
87 int error, t;
88 struct sysctlnode node;
89
90 node = *rnode;
91 t = *(int*)rnode->sysctl_data;
92 node.sysctl_data = &t;
93 error = sysctl_lookup(SYSCTLFN_CALL(&node));
94 if (error || newp == NULL)
95 return (error);
96
97 IEEE80211_DPRINTF(("%s: t = %d, nodenum = %d, rnodenum = %d\n",
98 __func__, t, node.sysctl_num, rnode->sysctl_num));
99
100 if (t < 0 || t > 2)
101 return (EINVAL);
102 *(int*)rnode->sysctl_data = t;
103
104 return (0);
105 }
106 #endif /* IEEE80211_DEBUG */
107
108 /* TBD factor with sysctl_ath_verify, sysctl_ieee80211_verify. */
109 static int
110 sysctl_ieee80211_rssadapt_expavgctl(SYSCTLFN_ARGS)
111 {
112 struct ieee80211_rssadapt_expavgctl rc;
113 int error;
114 struct sysctlnode node;
115
116 node = *rnode;
117 rc = *(struct ieee80211_rssadapt_expavgctl *)rnode->sysctl_data;
118 node.sysctl_data = &rc;
119 error = sysctl_lookup(SYSCTLFN_CALL(&node));
120 if (error || newp == NULL)
121 return (error);
122
123 IEEE80211_DPRINTF(("%s: decay = %d/%d, thresh = %d/%d, "
124 "avgrssi = %d/%d, nodenum = %d, rnodenum = %d\n",
125 __func__, rc.rc_decay_old, rc.rc_decay_denom,
126 rc.rc_thresh_old, rc.rc_thresh_denom,
127 rc.rc_avgrssi_old, rc.rc_avgrssi_denom,
128 node.sysctl_num, rnode->sysctl_num));
129
130 if (rc.rc_decay_old < 0 ||
131 rc.rc_decay_denom < rc.rc_decay_old)
132 return (EINVAL);
133
134 if (rc.rc_thresh_old < 0 ||
135 rc.rc_thresh_denom < rc.rc_thresh_old)
136 return (EINVAL);
137
138 if (rc.rc_avgrssi_old < 0 ||
139 rc.rc_avgrssi_denom < rc.rc_avgrssi_old)
140 return (EINVAL);
141
142 *(struct ieee80211_rssadapt_expavgctl *)rnode->sysctl_data = rc;
143
144 return (0);
145 }
146
147 /*
148 * Setup sysctl(3) MIB, net.ieee80211.*
149 *
150 * TBD condition CTLFLAG_PERMANENT on being an LKM or not
151 */
152 SYSCTL_SETUP(sysctl_ieee80211_rssadapt,
153 "sysctl ieee80211 rssadapt subtree setup")
154 {
155 int rc;
156 struct sysctlnode *node;
157
158 if ((rc = sysctl_createv(clog, 0, NULL, &node,
159 CTLFLAG_PERMANENT, CTLTYPE_NODE, "net", NULL,
160 NULL, 0, NULL, 0, CTL_NET, CTL_EOL)) != 0)
161 goto err;
162
163 if ((rc = sysctl_createv(clog, 0, &node, &node,
164 CTLFLAG_PERMANENT, CTLTYPE_NODE, "link", NULL,
165 NULL, 0, NULL, 0, PF_LINK, CTL_EOL)) != 0)
166 goto err;
167
168 if ((rc = sysctl_createv(clog, 0, &node, &node,
169 CTLFLAG_PERMANENT, CTLTYPE_NODE, "ieee80211", NULL,
170 NULL, 0, NULL, 0, CTL_CREATE, CTL_EOL)) != 0)
171 goto err;
172
173 if ((rc = sysctl_createv(clog, 0, &node, &node,
174 CTLFLAG_PERMANENT, CTLTYPE_NODE, "rssadapt", NULL,
175 NULL, 0, NULL, 0, CTL_CREATE, CTL_EOL)) != 0)
176 goto err;
177
178 #ifdef IEEE80211_DEBUG
179 /* control debugging printfs */
180 if ((rc = sysctl_createv(clog, 0, &node, NULL,
181 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, CTLTYPE_INT, "debug", NULL,
182 sysctl_ieee80211_rssadapt_debug, 0, &ieee80211_rssadapt_debug, 0,
183 CTL_CREATE, CTL_EOL)) != 0)
184 goto err;
185 #endif /* IEEE80211_DEBUG */
186
187 /* control rate of decay for exponential averages */
188 if ((rc = sysctl_createv(clog, 0, &node, NULL,
189 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, CTLTYPE_STRUCT,
190 "expavgctl", NULL, sysctl_ieee80211_rssadapt_expavgctl, 0,
191 &master_expavgctl, sizeof(master_expavgctl), CTL_CREATE,
192 CTL_EOL)) != 0)
193 goto err;
194
195 return;
196 err:
197 printf("%s: sysctl_createv failed (rc = %d)\n", __func__, rc);
198 }
199 #endif /* __NetBSD__ */
200
201 int
202 ieee80211_rssadapt_choose(struct ieee80211_rssadapt *ra,
203 struct ieee80211_rateset *rs, struct ieee80211_frame *wh, u_int len,
204 int fixed_rate, const char *dvname, int do_not_adapt)
205 {
206 u_int16_t (*thrs)[IEEE80211_RATE_SIZE];
207 int flags = 0, i, rateidx = 0, thridx, top;
208
209 if ((wh->i_fc[0] & IEEE80211_FC0_TYPE_MASK) == IEEE80211_FC0_TYPE_CTL)
210 flags |= IEEE80211_RATE_BASIC;
211
212 for (i = 0, top = IEEE80211_RSSADAPT_BKT0;
213 i < IEEE80211_RSSADAPT_BKTS;
214 i++, top <<= IEEE80211_RSSADAPT_BKTPOWER) {
215 thridx = i;
216 if (len <= top)
217 break;
218 }
219
220 thrs = &ra->ra_rate_thresh[thridx];
221
222 if (fixed_rate != -1) {
223 if ((rs->rs_rates[fixed_rate] & flags) == flags) {
224 rateidx = fixed_rate;
225 goto out;
226 }
227 flags |= IEEE80211_RATE_BASIC;
228 i = fixed_rate;
229 } else
230 i = rs->rs_nrates;
231
232 while (--i >= 0) {
233 rateidx = i;
234 if ((rs->rs_rates[i] & flags) != flags)
235 continue;
236 if (do_not_adapt)
237 break;
238 if ((*thrs)[i] < ra->ra_avg_rssi)
239 break;
240 }
241
242 out:
243 #ifdef IEEE80211_DEBUG
244 if (ieee80211_rssadapt_debug && dvname != NULL) {
245 printf("%s: dst %s threshold[%d, %d.%d] %d < %d\n",
246 dvname, ether_sprintf(wh->i_addr1), len,
247 (rs->rs_rates[rateidx] & IEEE80211_RATE_VAL) / 2,
248 (rs->rs_rates[rateidx] & IEEE80211_RATE_VAL) * 5 % 10,
249 (*thrs)[rateidx], ra->ra_avg_rssi);
250 }
251 #endif /* IEEE80211_DEBUG */
252 return rateidx;
253 }
254
255 void
256 ieee80211_rssadapt_updatestats(struct ieee80211_rssadapt *ra)
257 {
258 long interval;
259
260 ra->ra_pktrate =
261 (ra->ra_pktrate + 10 * (ra->ra_nfail + ra->ra_nok)) / 2;
262 ra->ra_nfail = ra->ra_nok = 0;
263
264 /* a node is eligible for its rate to be raised every 1/10 to 10
265 * seconds, more eligible in proportion to recent packet rates.
266 */
267 interval = MAX(100000, 10000000 / MAX(1, 10 * ra->ra_pktrate));
268 ra->ra_raise_interval.tv_sec = interval / (1000 * 1000);
269 ra->ra_raise_interval.tv_usec = interval % (1000 * 1000);
270 }
271
272 void
273 ieee80211_rssadapt_input(struct ieee80211com *ic, struct ieee80211_node *ni,
274 struct ieee80211_rssadapt *ra, int rssi)
275 {
276 #ifdef IEEE80211_DEBUG
277 int last_avg_rssi = ra->ra_avg_rssi;
278 #endif
279
280 ra->ra_avg_rssi = interpolate(master_expavgctl.rc_avgrssi,
281 ra->ra_avg_rssi, (rssi << 8));
282
283 RSSADAPT_PRINTF(("%s: src %s rssi %d avg %d -> %d\n",
284 ic->ic_if.if_xname, ether_sprintf(ni->ni_macaddr),
285 rssi, last_avg_rssi, ra->ra_avg_rssi));
286 }
287
288 /*
289 * Adapt the data rate to suit the conditions. When a transmitted
290 * packet is dropped after IEEE80211_RSSADAPT_RETRY_LIMIT retransmissions,
291 * raise the RSS threshold for transmitting packets of similar length at
292 * the same data rate.
293 */
294 void
295 ieee80211_rssadapt_lower_rate(struct ieee80211com *ic,
296 struct ieee80211_node *ni, struct ieee80211_rssadapt *ra,
297 struct ieee80211_rssdesc *id)
298 {
299 struct ieee80211_rateset *rs = &ni->ni_rates;
300 u_int16_t last_thr;
301 u_int i, thridx, top;
302
303 ra->ra_nfail++;
304
305 if (id->id_rateidx >= rs->rs_nrates) {
306 RSSADAPT_PRINTF(("ieee80211_rssadapt_lower_rate: "
307 "%s rate #%d > #%d out of bounds\n",
308 ether_sprintf(ni->ni_macaddr), id->id_rateidx,
309 rs->rs_nrates - 1));
310 return;
311 }
312
313 for (i = 0, top = IEEE80211_RSSADAPT_BKT0;
314 i < IEEE80211_RSSADAPT_BKTS;
315 i++, top <<= IEEE80211_RSSADAPT_BKTPOWER) {
316 thridx = i;
317 if (id->id_len <= top)
318 break;
319 }
320
321 last_thr = ra->ra_rate_thresh[thridx][id->id_rateidx];
322 ra->ra_rate_thresh[thridx][id->id_rateidx] =
323 interpolate(master_expavgctl.rc_thresh, last_thr,
324 (id->id_rssi << 8));
325
326 RSSADAPT_PRINTF(("%s: dst %s rssi %d threshold[%d, %d.%d] %d -> %d\n",
327 ic->ic_if.if_xname, ether_sprintf(ni->ni_macaddr),
328 id->id_rssi, id->id_len,
329 (rs->rs_rates[id->id_rateidx] & IEEE80211_RATE_VAL) / 2,
330 (rs->rs_rates[id->id_rateidx] & IEEE80211_RATE_VAL) * 5 % 10,
331 last_thr, ra->ra_rate_thresh[thridx][id->id_rateidx]));
332 }
333
334 void
335 ieee80211_rssadapt_raise_rate(struct ieee80211com *ic,
336 struct ieee80211_rssadapt *ra, struct ieee80211_rssdesc *id)
337 {
338 u_int16_t (*thrs)[IEEE80211_RATE_SIZE], newthr, oldthr;
339 struct ieee80211_node *ni = id->id_node;
340 struct ieee80211_rateset *rs = &ni->ni_rates;
341 int i, rate, top;
342 #ifdef IEEE80211_DEBUG
343 int j;
344 #endif
345
346 ra->ra_nok++;
347
348 if (!ratecheck(&ra->ra_last_raise, &ra->ra_raise_interval))
349 return;
350
351 for (i = 0, top = IEEE80211_RSSADAPT_BKT0;
352 i < IEEE80211_RSSADAPT_BKTS;
353 i++, top <<= IEEE80211_RSSADAPT_BKTPOWER) {
354 thrs = &ra->ra_rate_thresh[i];
355 if (id->id_len <= top)
356 break;
357 }
358
359 if (id->id_rateidx + 1 < rs->rs_nrates &&
360 (*thrs)[id->id_rateidx + 1] > (*thrs)[id->id_rateidx]) {
361 rate = (rs->rs_rates[id->id_rateidx + 1] & IEEE80211_RATE_VAL);
362
363 RSSADAPT_PRINTF(("%s: threshold[%d, %d.%d] decay %d ",
364 ic->ic_if.if_xname,
365 IEEE80211_RSSADAPT_BKT0 << (IEEE80211_RSSADAPT_BKTPOWER* i),
366 rate / 2, rate * 5 % 10, (*thrs)[id->id_rateidx + 1]));
367 oldthr = (*thrs)[id->id_rateidx + 1];
368 if ((*thrs)[id->id_rateidx] == 0)
369 newthr = ra->ra_avg_rssi;
370 else
371 newthr = (*thrs)[id->id_rateidx];
372 (*thrs)[id->id_rateidx + 1] =
373 interpolate(master_expavgctl.rc_decay, oldthr, newthr);
374
375 RSSADAPT_PRINTF(("-> %d\n", (*thrs)[id->id_rateidx + 1]));
376 }
377
378 #ifdef IEEE80211_DEBUG
379 if (RSSADAPT_DO_PRINT()) {
380 printf("%s: dst %s thresholds\n", ic->ic_if.if_xname,
381 ether_sprintf(ni->ni_macaddr));
382 for (i = 0; i < IEEE80211_RSSADAPT_BKTS; i++) {
383 printf("%d-byte", IEEE80211_RSSADAPT_BKT0 << (IEEE80211_RSSADAPT_BKTPOWER * i));
384 for (j = 0; j < rs->rs_nrates; j++) {
385 rate = (rs->rs_rates[j] & IEEE80211_RATE_VAL);
386 printf(", T[%d.%d] = %d", rate / 2,
387 rate * 5 % 10, ra->ra_rate_thresh[i][j]);
388 }
389 printf("\n");
390 }
391 }
392 #endif /* IEEE80211_DEBUG */
393 }
394