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ieee80211_amrr.c revision 1.1 
      1 /*	$OpenBSD: ieee80211_amrr.c,v 1.1 2006/06/17 19:07:19 damien Exp $	*/
      2 /*	$NetBSD: ieee80211_amrr.c,v 1.1 2006/10/31 21:53:41 joerg Exp $	*/
      3 
      4 /*-
      5  * Copyright (c) 2006
      6  *	Damien Bergamini <damien.bergamini (at) free.fr>
      7  *
      8  * Permission to use, copy, modify, and distribute this software for any
      9  * purpose with or without fee is hereby granted, provided that the above
     10  * copyright notice and this permission notice appear in all copies.
     11  *
     12  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
     13  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
     14  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
     15  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
     16  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
     17  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
     18  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
     19  */
     20 
     21 #include <sys/param.h>
     22 #include <sys/kernel.h>
     23 #include <sys/socket.h>
     24 #include <sys/sysctl.h>
     25 
     26 #include <net/if.h>
     27 #include <net/if_media.h>
     28 
     29 #ifdef INET
     30 #include <netinet/in.h>
     31 #include <netinet/if_ether.h>
     32 #endif
     33 
     34 #include <net80211/ieee80211.h>
     35 #include <net80211/ieee80211_var.h>
     36 #include <net80211/ieee80211_amrr.h>
     37 
     38 #define is_success(amn)	\
     39 	((amn)->amn_retrycnt < (amn)->amn_txcnt / 10)
     40 #define is_failure(amn)	\
     41 	((amn)->amn_retrycnt > (amn)->amn_txcnt / 3)
     42 #define is_enough(amn)		\
     43 	((amn)->amn_txcnt > 10)
     44 #define is_min_rate(ni)		\
     45 	((ni)->ni_txrate == 0)
     46 #define is_max_rate(ni)		\
     47 	((ni)->ni_txrate == (ni)->ni_rates.rs_nrates - 1)
     48 #define increase_rate(ni)	\
     49 	((ni)->ni_txrate++)
     50 #define decrease_rate(ni)	\
     51 	((ni)->ni_txrate--)
     52 #define reset_cnt(amn)		\
     53 	do { (amn)->amn_txcnt = (amn)->amn_retrycnt = 0; } while (0)
     54 
     55 void
     56 ieee80211_amrr_node_init(struct ieee80211_amrr *amrr,
     57     struct ieee80211_amrr_node *amn)
     58 {
     59 	amn->amn_success = 0;
     60 	amn->amn_recovery = 0;
     61 	amn->amn_txcnt = amn->amn_retrycnt = 0;
     62 	amn->amn_success_threshold = amrr->amrr_min_success_threshold;
     63 }
     64 
     65 /*
     66  * Update ni->ni_txrate.
     67  */
     68 void
     69 ieee80211_amrr_choose(struct ieee80211_amrr *amrr, struct ieee80211_node *ni,
     70     struct ieee80211_amrr_node *amn)
     71 {
     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 			IEEE80211_DPRINTF(ni->ni_ic, IEEE80211_MSG_DEBUG,
     82 			    "AMRR increasing rate %d (txcnt=%d retrycnt=%d)\n",
     83 			    ni->ni_rates.rs_rates[ni->ni_txrate] &
     84 				IEEE80211_RATE_VAL,
     85 			    amn->amn_txcnt, amn->amn_retrycnt);
     86 			need_change = 1;
     87 		} else {
     88 			amn->amn_recovery = 0;
     89 		}
     90 	} else if (is_failure(amn)) {
     91 		amn->amn_success = 0;
     92 		if (!is_min_rate(ni)) {
     93 			if (amn->amn_recovery) {
     94 				amn->amn_success_threshold *= 2;
     95 				if (amn->amn_success_threshold >
     96 				    amrr->amrr_max_success_threshold)
     97 					amn->amn_success_threshold =
     98 					    amrr->amrr_max_success_threshold;
     99 			} else {
    100 				amn->amn_success_threshold =
    101 				    amrr->amrr_min_success_threshold;
    102 			}
    103 			decrease_rate(ni);
    104 			IEEE80211_DPRINTF(ni->ni_ic, IEEE80211_MSG_DEBUG,
    105 			    "AMRR decreasing rate %d (txcnt=%d retrycnt=%d)\n",
    106 			    ni->ni_rates.rs_rates[ni->ni_txrate] &
    107 				IEEE80211_RATE_VAL,
    108 			    amn->amn_txcnt, amn->amn_retrycnt);
    109 			need_change = 1;
    110 		}
    111 		amn->amn_recovery = 0;
    112 	}
    113 
    114 	if (is_enough(amn) || need_change)
    115 		reset_cnt(amn);
    116 }
    117