1 /* $OpenBSD: ieee80211_amrr.c,v 1.7 2011/03/02 08:48:59 fgsch 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 #ifdef INET 29 #include <netinet/in.h> 30 #include <netinet/if_ether.h> 31 #endif 32 33 #include <net80211/ieee80211_var.h> 34 #include <net80211/ieee80211_priv.h> 35 #include <net80211/ieee80211_amrr.h> 36 37 #define is_success(amn) \ 38 ((amn)->amn_retrycnt < (amn)->amn_txcnt / 10) 39 #define is_failure(amn) \ 40 ((amn)->amn_retrycnt > (amn)->amn_txcnt / 3) 41 #define is_enough(amn) \ 42 ((amn)->amn_txcnt > 10) 43 #define is_min_rate(ni) \ 44 ((ni)->ni_txrate == 0) 45 #define is_max_rate(ni) \ 46 ((ni)->ni_txrate == (ni)->ni_rates.rs_nrates - 1) 47 #define increase_rate(ni) \ 48 ((ni)->ni_txrate++) 49 #define decrease_rate(ni) \ 50 ((ni)->ni_txrate--) 51 #define reset_cnt(amn) \ 52 do { (amn)->amn_txcnt = (amn)->amn_retrycnt = 0; } while (0) 53 54 void 55 ieee80211_amrr_node_init(const struct ieee80211_amrr *amrr, 56 struct ieee80211_amrr_node *amn) 57 { 58 amn->amn_success = 0; 59 amn->amn_recovery = 0; 60 amn->amn_txcnt = amn->amn_retrycnt = 0; 61 amn->amn_success_threshold = amrr->amrr_min_success_threshold; 62 } 63 64 /* 65 * Update ni->ni_txrate. 66 */ 67 void 68 ieee80211_amrr_choose(struct ieee80211_amrr *amrr, struct ieee80211_node *ni, 69 struct ieee80211_amrr_node *amn) 70 { 71 #define RV(rate) ((rate) & IEEE80211_RATE_VAL) 72 int need_change = 0; 73 74 if (is_success(amn) && is_enough(amn)) { 75 amn->amn_success++; 76 if (amn->amn_success >= amn->amn_success_threshold && 77 !is_max_rate(ni)) { 78 amn->amn_recovery = 1; 79 amn->amn_success = 0; 80 increase_rate(ni); 81 DPRINTF(("increase rate=%d,#tx=%d,#retries=%d\n", 82 RV(ni->ni_rates.rs_rates[ni->ni_txrate]), 83 amn->amn_txcnt, amn->amn_retrycnt)); 84 need_change = 1; 85 } else { 86 amn->amn_recovery = 0; 87 } 88 } else if (is_failure(amn)) { 89 amn->amn_success = 0; 90 if (!is_min_rate(ni)) { 91 if (amn->amn_recovery) { 92 amn->amn_success_threshold *= 2; 93 if (amn->amn_success_threshold > 94 amrr->amrr_max_success_threshold) 95 amn->amn_success_threshold = 96 amrr->amrr_max_success_threshold; 97 } else { 98 amn->amn_success_threshold = 99 amrr->amrr_min_success_threshold; 100 } 101 decrease_rate(ni); 102 DPRINTF(("decrease rate=%d,#tx=%d,#retries=%d\n", 103 RV(ni->ni_rates.rs_rates[ni->ni_txrate]), 104 amn->amn_txcnt, amn->amn_retrycnt)); 105 need_change = 1; 106 } 107 amn->amn_recovery = 0; 108 } 109 110 if (is_enough(amn) || need_change) 111 reset_cnt(amn); 112 #undef RV 113 } 114