Line data Source code
1 : /* $OpenBSD: ieee80211_rssadapt.c,v 1.11 2014/12/23 03:24:08 tedu Exp $ */
2 : /* $NetBSD: ieee80211_rssadapt.c,v 1.7 2004/05/25 04:33:59 dyoung Exp $ */
3 :
4 : /*-
5 : * Copyright (c) 2003, 2004 David Young. All rights reserved.
6 : *
7 : * Redistribution and use in source and binary forms, with or
8 : * without modification, are permitted provided that the following
9 : * conditions are met:
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 : *
17 : * THIS SOFTWARE IS PROVIDED BY David Young ``AS IS'' AND ANY
18 : * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
19 : * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
20 : * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL David
21 : * Young BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
22 : * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
23 : * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 : * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
25 : * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
26 : * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 : * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
28 : * OF SUCH DAMAGE.
29 : */
30 :
31 : #include <sys/param.h>
32 : #include <sys/systm.h>
33 : #include <sys/kernel.h>
34 : #include <sys/socket.h>
35 :
36 : #include <net/if.h>
37 : #include <net/if_media.h>
38 :
39 : #include <netinet/in.h>
40 : #include <netinet/if_ether.h>
41 :
42 : #include <net80211/ieee80211_var.h>
43 : #include <net80211/ieee80211_rssadapt.h>
44 :
45 : #ifdef interpolate
46 : #undef interpolate
47 : #endif
48 : #define interpolate(parm, old, new) \
49 : ((parm##_old * (old) + \
50 : (parm##_denom - parm##_old) * (new)) / parm##_denom)
51 :
52 : #ifdef IEEE80211_DEBUG
53 : static struct timeval lastrateadapt; /* time of last rate adaptation msg */
54 : static int currssadaptps = 0; /* rate-adaptation msgs this second */
55 : static int ieee80211_adaptrate = 4; /* rate-adaptation max msgs/sec */
56 :
57 : #define RSSADAPT_DO_PRINT() \
58 : ((ieee80211_rssadapt_debug > 0) && \
59 : ppsratecheck(&lastrateadapt, &currssadaptps, ieee80211_adaptrate))
60 : #define RSSADAPT_PRINTF(X) \
61 : if (RSSADAPT_DO_PRINT()) \
62 : printf X
63 :
64 : int ieee80211_rssadapt_debug = 0;
65 :
66 : #else
67 : #define RSSADAPT_DO_PRINT() (0)
68 : #define RSSADAPT_PRINTF(X)
69 : #endif
70 :
71 : static const struct ieee80211_rssadapt_expavgctl master_expavgctl = {
72 : .rc_decay_denom = 16,
73 : .rc_decay_old = 15,
74 : .rc_thresh_denom = 8,
75 : .rc_thresh_old = 4,
76 : .rc_avgrssi_denom = 8,
77 : .rc_avgrssi_old = 4
78 : };
79 :
80 : int
81 0 : ieee80211_rssadapt_choose(struct ieee80211_rssadapt *ra,
82 : const struct ieee80211_rateset *rs, const struct ieee80211_frame *wh,
83 : u_int len, int fixed_rate, const char *dvname, int do_not_adapt)
84 : {
85 : u_int16_t (*thrs)[IEEE80211_RATE_SIZE];
86 : int flags = 0, i, rateidx = 0, thridx, top;
87 :
88 0 : if ((wh->i_fc[0] & IEEE80211_FC0_TYPE_MASK) == IEEE80211_FC0_TYPE_CTL)
89 0 : flags |= IEEE80211_RATE_BASIC;
90 :
91 0 : for (i = 0, top = IEEE80211_RSSADAPT_BKT0;
92 0 : i < IEEE80211_RSSADAPT_BKTS;
93 0 : i++, top <<= IEEE80211_RSSADAPT_BKTPOWER) {
94 : thridx = i;
95 0 : if (len <= top)
96 : break;
97 : }
98 :
99 0 : thrs = &ra->ra_rate_thresh[thridx];
100 :
101 0 : if (fixed_rate != -1) {
102 0 : if ((rs->rs_rates[fixed_rate] & flags) == flags) {
103 : rateidx = fixed_rate;
104 0 : goto out;
105 : }
106 : flags |= IEEE80211_RATE_BASIC;
107 : i = fixed_rate;
108 0 : } else
109 0 : i = rs->rs_nrates;
110 :
111 0 : while (--i >= 0) {
112 : rateidx = i;
113 0 : if ((rs->rs_rates[i] & flags) != flags)
114 0 : continue;
115 0 : if (do_not_adapt)
116 : break;
117 0 : if ((*thrs)[i] < ra->ra_avg_rssi)
118 : break;
119 : }
120 :
121 : out:
122 : #ifdef IEEE80211_DEBUG
123 : if (ieee80211_rssadapt_debug && dvname != NULL) {
124 : printf("%s: dst %s threshold[%d, %d.%d] %d < %d\n",
125 : dvname, ether_sprintf((u_int8_t *)wh->i_addr1), len,
126 : (rs->rs_rates[rateidx] & IEEE80211_RATE_VAL) / 2,
127 : (rs->rs_rates[rateidx] & IEEE80211_RATE_VAL) * 5 % 10,
128 : (*thrs)[rateidx], ra->ra_avg_rssi);
129 : }
130 : #endif /* IEEE80211_DEBUG */
131 0 : return rateidx;
132 : }
133 :
134 : void
135 0 : ieee80211_rssadapt_updatestats(struct ieee80211_rssadapt *ra)
136 : {
137 : long interval;
138 :
139 0 : ra->ra_pktrate =
140 0 : (ra->ra_pktrate + 10 * (ra->ra_nfail + ra->ra_nok)) / 2;
141 0 : ra->ra_nfail = ra->ra_nok = 0;
142 :
143 : /* a node is eligible for its rate to be raised every 1/10 to 10
144 : * seconds, more eligible in proportion to recent packet rates.
145 : */
146 0 : interval = MAX(100000, 10000000 / MAX(1, 10 * ra->ra_pktrate));
147 0 : ra->ra_raise_interval.tv_sec = interval / (1000 * 1000);
148 0 : ra->ra_raise_interval.tv_usec = interval % (1000 * 1000);
149 0 : }
150 :
151 : void
152 0 : ieee80211_rssadapt_input(struct ieee80211com *ic,
153 : const struct ieee80211_node *ni, struct ieee80211_rssadapt *ra, int rssi)
154 : {
155 : #ifdef IEEE80211_DEBUG
156 : int last_avg_rssi = ra->ra_avg_rssi;
157 : #endif
158 :
159 0 : ra->ra_avg_rssi = interpolate(master_expavgctl.rc_avgrssi,
160 : ra->ra_avg_rssi, (rssi << 8));
161 :
162 : RSSADAPT_PRINTF(("%s: src %s rssi %d avg %d -> %d\n",
163 : ic->ic_if.if_xname, ether_sprintf((u_int8_t *)ni->ni_macaddr),
164 : rssi, last_avg_rssi, ra->ra_avg_rssi));
165 0 : }
166 :
167 : /*
168 : * Adapt the data rate to suit the conditions. When a transmitted
169 : * packet is dropped after IEEE80211_RSSADAPT_RETRY_LIMIT retransmissions,
170 : * raise the RSS threshold for transmitting packets of similar length at
171 : * the same data rate.
172 : */
173 : void
174 0 : ieee80211_rssadapt_lower_rate(struct ieee80211com *ic,
175 : const struct ieee80211_node *ni, struct ieee80211_rssadapt *ra,
176 : const struct ieee80211_rssdesc *id)
177 : {
178 0 : const struct ieee80211_rateset *rs = &ni->ni_rates;
179 : u_int16_t last_thr;
180 : u_int i, thridx, top;
181 :
182 0 : ra->ra_nfail++;
183 :
184 0 : if (id->id_rateidx >= rs->rs_nrates) {
185 : RSSADAPT_PRINTF(("ieee80211_rssadapt_lower_rate: "
186 : "%s rate #%d > #%d out of bounds\n",
187 : ether_sprintf((u_int8_t *)ni->ni_macaddr), id->id_rateidx,
188 : rs->rs_nrates - 1));
189 0 : return;
190 : }
191 :
192 0 : for (i = 0, top = IEEE80211_RSSADAPT_BKT0;
193 0 : i < IEEE80211_RSSADAPT_BKTS;
194 0 : i++, top <<= IEEE80211_RSSADAPT_BKTPOWER) {
195 : thridx = i;
196 0 : if (id->id_len <= top)
197 : break;
198 : }
199 :
200 0 : last_thr = ra->ra_rate_thresh[thridx][id->id_rateidx];
201 0 : ra->ra_rate_thresh[thridx][id->id_rateidx] =
202 0 : interpolate(master_expavgctl.rc_thresh, last_thr,
203 : (id->id_rssi << 8));
204 :
205 : RSSADAPT_PRINTF(("%s: dst %s rssi %d threshold[%d, %d.%d] %d -> %d\n",
206 : ic->ic_if.if_xname, ether_sprintf((u_int8_t *)ni->ni_macaddr),
207 : id->id_rssi, id->id_len,
208 : (rs->rs_rates[id->id_rateidx] & IEEE80211_RATE_VAL) / 2,
209 : (rs->rs_rates[id->id_rateidx] & IEEE80211_RATE_VAL) * 5 % 10,
210 : last_thr, ra->ra_rate_thresh[thridx][id->id_rateidx]));
211 0 : }
212 :
213 : void
214 0 : ieee80211_rssadapt_raise_rate(struct ieee80211com *ic,
215 : struct ieee80211_rssadapt *ra, const struct ieee80211_rssdesc *id)
216 : {
217 : u_int16_t (*thrs)[IEEE80211_RATE_SIZE], newthr, oldthr;
218 0 : const struct ieee80211_node *ni = id->id_node;
219 0 : const struct ieee80211_rateset *rs = &ni->ni_rates;
220 : int i, rate, top;
221 : #ifdef IEEE80211_DEBUG
222 : int j;
223 : #endif
224 :
225 0 : ra->ra_nok++;
226 :
227 0 : if (!ratecheck(&ra->ra_last_raise, &ra->ra_raise_interval))
228 0 : return;
229 :
230 0 : for (i = 0, top = IEEE80211_RSSADAPT_BKT0;
231 0 : i < IEEE80211_RSSADAPT_BKTS;
232 0 : i++, top <<= IEEE80211_RSSADAPT_BKTPOWER) {
233 0 : thrs = &ra->ra_rate_thresh[i];
234 0 : if (id->id_len <= top)
235 : break;
236 : }
237 :
238 0 : if (id->id_rateidx + 1 < rs->rs_nrates &&
239 0 : (*thrs)[id->id_rateidx + 1] > (*thrs)[id->id_rateidx]) {
240 0 : rate = (rs->rs_rates[id->id_rateidx + 1] & IEEE80211_RATE_VAL);
241 :
242 : RSSADAPT_PRINTF(("%s: threshold[%d, %d.%d] decay %d ",
243 : ic->ic_if.if_xname, IEEE80211_RSSADAPT_BKT0 <<
244 : (IEEE80211_RSSADAPT_BKTPOWER * i),
245 : rate / 2, rate * 5 % 10, (*thrs)[id->id_rateidx + 1]));
246 : oldthr = (*thrs)[id->id_rateidx + 1];
247 0 : if ((*thrs)[id->id_rateidx] == 0)
248 0 : newthr = ra->ra_avg_rssi;
249 : else
250 : newthr = (*thrs)[id->id_rateidx];
251 0 : (*thrs)[id->id_rateidx + 1] =
252 0 : interpolate(master_expavgctl.rc_decay, oldthr, newthr);
253 :
254 : RSSADAPT_PRINTF(("-> %d\n", (*thrs)[id->id_rateidx + 1]));
255 0 : }
256 :
257 : #ifdef IEEE80211_DEBUG
258 : if (RSSADAPT_DO_PRINT()) {
259 : printf("%s: dst %s thresholds\n", ic->ic_if.if_xname,
260 : ether_sprintf((u_int8_t *)ni->ni_macaddr));
261 : for (i = 0; i < IEEE80211_RSSADAPT_BKTS; i++) {
262 : printf("%d-byte", IEEE80211_RSSADAPT_BKT0 <<
263 : (IEEE80211_RSSADAPT_BKTPOWER * i));
264 : for (j = 0; j < rs->rs_nrates; j++) {
265 : rate = (rs->rs_rates[j] & IEEE80211_RATE_VAL);
266 : printf(", T[%d.%d] = %d", rate / 2,
267 : rate * 5 % 10, ra->ra_rate_thresh[i][j]);
268 : }
269 : printf("\n");
270 : }
271 : }
272 : #endif /* IEEE80211_DEBUG */
273 0 : }
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