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ieee80211_amrr.c revision 1.1.30.1 
      1 /*	$NetBSD: ieee80211_amrr.c,v 1.1.30.1 2008/01/09 01:57:18 matt Exp $	*/
      2 /*	$OpenBSD: ieee80211_amrr.c,v 1.1 2006/06/17 19:07:19 damien 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/cdefs.h>
     22 __KERNEL_RCSID(0, "$NetBSD: ieee80211_amrr.c,v 1.1.30.1 2008/01/09 01:57:18 matt Exp $");
     23 
     24 #include <sys/param.h>
     25 #include <sys/kernel.h>
     26 #include <sys/socket.h>
     27 #include <sys/sysctl.h>
     28 
     29 #include <net/if.h>
     30 #include <net/if_media.h>
     31 
     32 #ifdef INET
     33 #include <netinet/in.h>
     34 #include <netinet/if_ether.h>
     35 #endif
     36 
     37 #include <net80211/ieee80211.h>
     38 #include <net80211/ieee80211_var.h>
     39 #include <net80211/ieee80211_amrr.h>
     40 
     41 #define is_success(amn)	\
     42 	((amn)->amn_retrycnt < (amn)->amn_txcnt / 10)
     43 #define is_failure(amn)	\
     44 	((amn)->amn_retrycnt > (amn)->amn_txcnt / 3)
     45 #define is_enough(amn)		\
     46 	((amn)->amn_txcnt > 10)
     47 #define is_min_rate(ni)		\
     48 	((ni)->ni_txrate == 0)
     49 #define is_max_rate(ni)		\
     50 	((ni)->ni_txrate == (ni)->ni_rates.rs_nrates - 1)
     51 #define increase_rate(ni)	\
     52 	((ni)->ni_txrate++)
     53 #define decrease_rate(ni)	\
     54 	((ni)->ni_txrate--)
     55 #define reset_cnt(amn)		\
     56 	do { (amn)->amn_txcnt = (amn)->amn_retrycnt = 0; } while (0)
     57 
     58 void
     59 ieee80211_amrr_node_init(struct ieee80211_amrr *amrr,
     60     struct ieee80211_amrr_node *amn)
     61 {
     62 	amn->amn_success = 0;
     63 	amn->amn_recovery = 0;
     64 	amn->amn_txcnt = amn->amn_retrycnt = 0;
     65 	amn->amn_success_threshold = amrr->amrr_min_success_threshold;
     66 }
     67 
     68 /*
     69  * Update ni->ni_txrate.
     70  */
     71 void
     72 ieee80211_amrr_choose(struct ieee80211_amrr *amrr, struct ieee80211_node *ni,
     73     struct ieee80211_amrr_node *amn)
     74 {
     75 	int need_change = 0;
     76 
     77 	if (is_success(amn) && is_enough(amn)) {
     78 		amn->amn_success++;
     79 		if (amn->amn_success >= amn->amn_success_threshold &&
     80 		    !is_max_rate(ni)) {
     81 			amn->amn_recovery = 1;
     82 			amn->amn_success = 0;
     83 			increase_rate(ni);
     84 			IEEE80211_DPRINTF(ni->ni_ic, IEEE80211_MSG_DEBUG,
     85 			    "AMRR increasing rate %d (txcnt=%d retrycnt=%d)\n",
     86 			    ni->ni_rates.rs_rates[ni->ni_txrate] &
     87 				IEEE80211_RATE_VAL,
     88 			    amn->amn_txcnt, amn->amn_retrycnt);
     89 			need_change = 1;
     90 		} else {
     91 			amn->amn_recovery = 0;
     92 		}
     93 	} else if (is_failure(amn)) {
     94 		amn->amn_success = 0;
     95 		if (!is_min_rate(ni)) {
     96 			if (amn->amn_recovery) {
     97 				amn->amn_success_threshold *= 2;
     98 				if (amn->amn_success_threshold >
     99 				    amrr->amrr_max_success_threshold)
    100 					amn->amn_success_threshold =
    101 					    amrr->amrr_max_success_threshold;
    102 			} else {
    103 				amn->amn_success_threshold =
    104 				    amrr->amrr_min_success_threshold;
    105 			}
    106 			decrease_rate(ni);
    107 			IEEE80211_DPRINTF(ni->ni_ic, IEEE80211_MSG_DEBUG,
    108 			    "AMRR decreasing rate %d (txcnt=%d retrycnt=%d)\n",
    109 			    ni->ni_rates.rs_rates[ni->ni_txrate] &
    110 				IEEE80211_RATE_VAL,
    111 			    amn->amn_txcnt, amn->amn_retrycnt);
    112 			need_change = 1;
    113 		}
    114 		amn->amn_recovery = 0;
    115 	}
    116 
    117 	if (is_enough(amn) || need_change)
    118 		reset_cnt(amn);
    119 }
    120