1 /* $OpenBSD: ieee80211_amrr.c,v 1.12 2019/02/24 09:36:28 stsp Exp $ */
2
3 /*-
4 * Copyright (c) 2006
5 * Damien Bergamini <damien.bergamini@free.fr>
6 *
7 * Permission to use, copy, modify, and distribute this software for any
8 * purpose with or without fee is hereby granted, provided that the above
9 * copyright notice and this permission notice appear in all copies.
10 *
11 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
12 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
13 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
14 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
15 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
16 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
17 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18 */
19
20 #include <sys/param.h>
21 #include <sys/systm.h>
22 #include <sys/kernel.h>
23 #include <sys/socket.h>
24
25 #include <net/if.h>
26 #include <net/if_media.h>
27
28 #include <netinet/in.h>
29 #include <netinet/if_ether.h>
30
31 #include <net80211/ieee80211_var.h>
32 #include <net80211/ieee80211_priv.h>
33 #include <net80211/ieee80211_amrr.h>
34
35 #define is_success(amn) \
36 ((amn)->amn_retrycnt < (amn)->amn_txcnt / 10)
37 #define is_failure(amn) \
38 ((amn)->amn_retrycnt > (amn)->amn_txcnt / 3)
39 #define is_enough(amn) \
40 ((amn)->amn_txcnt > 10)
41 #define reset_cnt(amn) \
42 do { (amn)->amn_txcnt = (amn)->amn_retrycnt = 0; } while (0)
43
44 static inline int
is_min_rate(struct ieee80211_node * ni)45 is_min_rate(struct ieee80211_node *ni)
46 {
47 return (ni->ni_txrate == 0);
48 }
49
50 static inline int
is_max_rate(struct ieee80211_node * ni)51 is_max_rate(struct ieee80211_node *ni)
52 {
53 return (ni->ni_txrate == ni->ni_rates.rs_nrates - 1);
54 }
55
56 static inline void
increase_rate(struct ieee80211_node * ni)57 increase_rate(struct ieee80211_node *ni)
58 {
59 ni->ni_txrate++;
60 }
61
62 static inline void
decrease_rate(struct ieee80211_node * ni)63 decrease_rate(struct ieee80211_node *ni)
64 {
65 ni->ni_txrate--;
66 }
67
68 void
ieee80211_amrr_node_init(const struct ieee80211_amrr * amrr,struct ieee80211_amrr_node * amn)69 ieee80211_amrr_node_init(const struct ieee80211_amrr *amrr,
70 struct ieee80211_amrr_node *amn)
71 {
72 amn->amn_success = 0;
73 amn->amn_recovery = 0;
74 amn->amn_txcnt = amn->amn_retrycnt = 0;
75 amn->amn_success_threshold = amrr->amrr_min_success_threshold;
76 }
77
78 /*
79 * Update ni->ni_txrate.
80 */
81 void
ieee80211_amrr_choose(struct ieee80211_amrr * amrr,struct ieee80211_node * ni,struct ieee80211_amrr_node * amn)82 ieee80211_amrr_choose(struct ieee80211_amrr *amrr, struct ieee80211_node *ni,
83 struct ieee80211_amrr_node *amn)
84 {
85 #define RV(rate) ((rate) & IEEE80211_RATE_VAL)
86 int need_change = 0;
87
88 if (is_success(amn) && is_enough(amn)) {
89 amn->amn_success++;
90 if (amn->amn_success >= amn->amn_success_threshold &&
91 !is_max_rate(ni)) {
92 amn->amn_recovery = 1;
93 amn->amn_success = 0;
94 increase_rate(ni);
95 DPRINTF(("increase rate=%d,#tx=%d,#retries=%d\n",
96 RV(ni->ni_rates.rs_rates[ni->ni_txrate]),
97 amn->amn_txcnt, amn->amn_retrycnt));
98 need_change = 1;
99 } else {
100 amn->amn_recovery = 0;
101 }
102 } else if (is_failure(amn)) {
103 amn->amn_success = 0;
104 if (!is_min_rate(ni)) {
105 if (amn->amn_recovery) {
106 amn->amn_success_threshold *= 2;
107 if (amn->amn_success_threshold >
108 amrr->amrr_max_success_threshold)
109 amn->amn_success_threshold =
110 amrr->amrr_max_success_threshold;
111 } else {
112 amn->amn_success_threshold =
113 amrr->amrr_min_success_threshold;
114 }
115 decrease_rate(ni);
116 DPRINTF(("decrease rate=%d,#tx=%d,#retries=%d\n",
117 RV(ni->ni_rates.rs_rates[ni->ni_txrate]),
118 amn->amn_txcnt, amn->amn_retrycnt));
119 need_change = 1;
120 }
121 amn->amn_recovery = 0;
122 }
123
124 if (is_enough(amn) || need_change)
125 reset_cnt(amn);
126 #undef RV
127 }
128