Annotation of sys/net80211/ieee80211_rssadapt.c, Revision 1.1.1.1
1.1 nbrk 1: /* $OpenBSD: ieee80211_rssadapt.c,v 1.6 2007/06/16 13:17:05 damien 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: * 3. The name of David Young may not be used to endorse or promote
17: * products derived from this software without specific prior
18: * written permission.
19: *
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
31: * OF SUCH DAMAGE.
32: */
33:
34: #include <sys/param.h>
35: #include <sys/kernel.h>
36: #include <sys/socket.h>
37: #include <sys/sysctl.h>
38:
39: #include <net/if.h>
40: #include <net/if_media.h>
41:
42: #ifdef INET
43: #include <netinet/in.h>
44: #include <netinet/if_ether.h>
45: #endif
46:
47: #include <net80211/ieee80211_var.h>
48: #include <net80211/ieee80211_rssadapt.h>
49:
50: #ifdef interpolate
51: #undef interpolate
52: #endif
53: #define interpolate(parm, old, new) \
54: ((parm##_old * (old) + \
55: (parm##_denom - parm##_old) * (new)) / parm##_denom)
56:
57: #ifdef IEEE80211_DEBUG
58: static struct timeval lastrateadapt; /* time of last rate adaptation msg */
59: static int currssadaptps = 0; /* rate-adaptation msgs this second */
60: static int ieee80211_adaptrate = 4; /* rate-adaptation max msgs/sec */
61:
62: #define RSSADAPT_DO_PRINT() \
63: ((ieee80211_rssadapt_debug > 0) && \
64: ppsratecheck(&lastrateadapt, &currssadaptps, ieee80211_adaptrate))
65: #define RSSADAPT_PRINTF(X) \
66: if (RSSADAPT_DO_PRINT()) \
67: printf X
68:
69: int ieee80211_rssadapt_debug = 0;
70:
71: #else
72: #define RSSADAPT_DO_PRINT() (0)
73: #define RSSADAPT_PRINTF(X)
74: #endif
75:
76: static struct ieee80211_rssadapt_expavgctl master_expavgctl = {
77: rc_decay_denom : 16,
78: rc_decay_old : 15,
79: rc_thresh_denom : 8,
80: rc_thresh_old : 4,
81: rc_avgrssi_denom : 8,
82: rc_avgrssi_old : 4
83: };
84:
85: int
86: ieee80211_rssadapt_choose(struct ieee80211_rssadapt *ra,
87: const struct ieee80211_rateset *rs, const struct ieee80211_frame *wh,
88: u_int len, int fixed_rate, const char *dvname, int do_not_adapt)
89: {
90: u_int16_t (*thrs)[IEEE80211_RATE_SIZE];
91: int flags = 0, i, rateidx = 0, thridx, top;
92:
93: if ((wh->i_fc[0] & IEEE80211_FC0_TYPE_MASK) == IEEE80211_FC0_TYPE_CTL)
94: flags |= IEEE80211_RATE_BASIC;
95:
96: for (i = 0, top = IEEE80211_RSSADAPT_BKT0;
97: i < IEEE80211_RSSADAPT_BKTS;
98: i++, top <<= IEEE80211_RSSADAPT_BKTPOWER) {
99: thridx = i;
100: if (len <= top)
101: break;
102: }
103:
104: thrs = &ra->ra_rate_thresh[thridx];
105:
106: if (fixed_rate != -1) {
107: if ((rs->rs_rates[fixed_rate] & flags) == flags) {
108: rateidx = fixed_rate;
109: goto out;
110: }
111: flags |= IEEE80211_RATE_BASIC;
112: i = fixed_rate;
113: } else
114: i = rs->rs_nrates;
115:
116: while (--i >= 0) {
117: rateidx = i;
118: if ((rs->rs_rates[i] & flags) != flags)
119: continue;
120: if (do_not_adapt)
121: break;
122: if ((*thrs)[i] < ra->ra_avg_rssi)
123: break;
124: }
125:
126: out:
127: #ifdef IEEE80211_DEBUG
128: if (ieee80211_rssadapt_debug && dvname != NULL) {
129: printf("%s: dst %s threshold[%d, %d.%d] %d < %d\n",
130: dvname, ether_sprintf((u_int8_t *)wh->i_addr1), len,
131: (rs->rs_rates[rateidx] & IEEE80211_RATE_VAL) / 2,
132: (rs->rs_rates[rateidx] & IEEE80211_RATE_VAL) * 5 % 10,
133: (*thrs)[rateidx], ra->ra_avg_rssi);
134: }
135: #endif /* IEEE80211_DEBUG */
136: return rateidx;
137: }
138:
139: void
140: ieee80211_rssadapt_updatestats(struct ieee80211_rssadapt *ra)
141: {
142: long interval;
143:
144: ra->ra_pktrate =
145: (ra->ra_pktrate + 10 * (ra->ra_nfail + ra->ra_nok)) / 2;
146: ra->ra_nfail = ra->ra_nok = 0;
147:
148: /* a node is eligible for its rate to be raised every 1/10 to 10
149: * seconds, more eligible in proportion to recent packet rates.
150: */
151: interval = MAX(100000, 10000000 / MAX(1, 10 * ra->ra_pktrate));
152: ra->ra_raise_interval.tv_sec = interval / (1000 * 1000);
153: ra->ra_raise_interval.tv_usec = interval % (1000 * 1000);
154: }
155:
156: void
157: ieee80211_rssadapt_input(struct ieee80211com *ic,
158: const struct ieee80211_node *ni, struct ieee80211_rssadapt *ra, int rssi)
159: {
160: #ifdef IEEE80211_DEBUG
161: int last_avg_rssi = ra->ra_avg_rssi;
162: #endif
163:
164: ra->ra_avg_rssi = interpolate(master_expavgctl.rc_avgrssi,
165: ra->ra_avg_rssi, (rssi << 8));
166:
167: RSSADAPT_PRINTF(("%s: src %s rssi %d avg %d -> %d\n",
168: ic->ic_if.if_xname, ether_sprintf((u_int8_t *)ni->ni_macaddr),
169: rssi, last_avg_rssi, ra->ra_avg_rssi));
170: }
171:
172: /*
173: * Adapt the data rate to suit the conditions. When a transmitted
174: * packet is dropped after IEEE80211_RSSADAPT_RETRY_LIMIT retransmissions,
175: * raise the RSS threshold for transmitting packets of similar length at
176: * the same data rate.
177: */
178: void
179: ieee80211_rssadapt_lower_rate(struct ieee80211com *ic,
180: const struct ieee80211_node *ni, struct ieee80211_rssadapt *ra,
181: const struct ieee80211_rssdesc *id)
182: {
183: const struct ieee80211_rateset *rs = &ni->ni_rates;
184: u_int16_t last_thr;
185: u_int i, thridx, top;
186:
187: ra->ra_nfail++;
188:
189: if (id->id_rateidx >= rs->rs_nrates) {
190: RSSADAPT_PRINTF(("ieee80211_rssadapt_lower_rate: "
191: "%s rate #%d > #%d out of bounds\n",
192: ether_sprintf((u_int8_t *)ni->ni_macaddr), id->id_rateidx,
193: rs->rs_nrates - 1));
194: return;
195: }
196:
197: for (i = 0, top = IEEE80211_RSSADAPT_BKT0;
198: i < IEEE80211_RSSADAPT_BKTS;
199: i++, top <<= IEEE80211_RSSADAPT_BKTPOWER) {
200: thridx = i;
201: if (id->id_len <= top)
202: break;
203: }
204:
205: last_thr = ra->ra_rate_thresh[thridx][id->id_rateidx];
206: ra->ra_rate_thresh[thridx][id->id_rateidx] =
207: interpolate(master_expavgctl.rc_thresh, last_thr,
208: (id->id_rssi << 8));
209:
210: RSSADAPT_PRINTF(("%s: dst %s rssi %d threshold[%d, %d.%d] %d -> %d\n",
211: ic->ic_if.if_xname, ether_sprintf((u_int8_t *)ni->ni_macaddr),
212: id->id_rssi, id->id_len,
213: (rs->rs_rates[id->id_rateidx] & IEEE80211_RATE_VAL) / 2,
214: (rs->rs_rates[id->id_rateidx] & IEEE80211_RATE_VAL) * 5 % 10,
215: last_thr, ra->ra_rate_thresh[thridx][id->id_rateidx]));
216: }
217:
218: void
219: ieee80211_rssadapt_raise_rate(struct ieee80211com *ic,
220: struct ieee80211_rssadapt *ra, const struct ieee80211_rssdesc *id)
221: {
222: u_int16_t (*thrs)[IEEE80211_RATE_SIZE], newthr, oldthr;
223: const struct ieee80211_node *ni = id->id_node;
224: const struct ieee80211_rateset *rs = &ni->ni_rates;
225: int i, rate, top;
226: #ifdef IEEE80211_DEBUG
227: int j;
228: #endif
229:
230: ra->ra_nok++;
231:
232: if (!ratecheck(&ra->ra_last_raise, &ra->ra_raise_interval))
233: return;
234:
235: for (i = 0, top = IEEE80211_RSSADAPT_BKT0;
236: i < IEEE80211_RSSADAPT_BKTS;
237: i++, top <<= IEEE80211_RSSADAPT_BKTPOWER) {
238: thrs = &ra->ra_rate_thresh[i];
239: if (id->id_len <= top)
240: break;
241: }
242:
243: if (id->id_rateidx + 1 < rs->rs_nrates &&
244: (*thrs)[id->id_rateidx + 1] > (*thrs)[id->id_rateidx]) {
245: rate = (rs->rs_rates[id->id_rateidx + 1] & IEEE80211_RATE_VAL);
246:
247: RSSADAPT_PRINTF(("%s: threshold[%d, %d.%d] decay %d ",
248: ic->ic_if.if_xname,
249: IEEE80211_RSSADAPT_BKT0 << (IEEE80211_RSSADAPT_BKTPOWER* i),
250: rate / 2, rate * 5 % 10, (*thrs)[id->id_rateidx + 1]));
251: oldthr = (*thrs)[id->id_rateidx + 1];
252: if ((*thrs)[id->id_rateidx] == 0)
253: newthr = ra->ra_avg_rssi;
254: else
255: newthr = (*thrs)[id->id_rateidx];
256: (*thrs)[id->id_rateidx + 1] =
257: interpolate(master_expavgctl.rc_decay, oldthr, newthr);
258:
259: RSSADAPT_PRINTF(("-> %d\n", (*thrs)[id->id_rateidx + 1]));
260: }
261:
262: #ifdef IEEE80211_DEBUG
263: if (RSSADAPT_DO_PRINT()) {
264: printf("%s: dst %s thresholds\n", ic->ic_if.if_xname,
265: ether_sprintf((u_int8_t *)ni->ni_macaddr));
266: for (i = 0; i < IEEE80211_RSSADAPT_BKTS; i++) {
267: printf("%d-byte", IEEE80211_RSSADAPT_BKT0 <<
268: (IEEE80211_RSSADAPT_BKTPOWER * i));
269: for (j = 0; j < rs->rs_nrates; j++) {
270: rate = (rs->rs_rates[j] & IEEE80211_RATE_VAL);
271: printf(", T[%d.%d] = %d", rate / 2,
272: rate * 5 % 10, ra->ra_rate_thresh[i][j]);
273: }
274: printf("\n");
275: }
276: }
277: #endif /* IEEE80211_DEBUG */
278: }
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