device-independent implementation of AMRR tx rate control algorithm

Obtained from:	openbsd (w/ mods)
MFC after:	1 month

2 files changed, 228 insertions, 0 deletions

diff --git a/sys/net80211/ieee80211_amrr.c b/sys/net80211/ieee80211_amrr.c
new file mode 100644
index 000000000000..60f6b934106e
--- /dev/null
+++ b/sys/net80211/ieee80211_amrr.c
@@ -0,0 +1,164 @@
+/*	$OpenBSD: ieee80211_amrr.c,v 1.1 2006/06/17 19:07:19 damien Exp $	*/
+
+/*-
+ * Copyright (c) 2006
+ *	Damien Bergamini <damien.bergamini@free.fr>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+/*-
+ * Naive implementation of the Adaptive Multi Rate Retry algorithm:
+ *
+ * "IEEE 802.11 Rate Adaptation: A Practical Approach"
+ *  Mathieu Lacage, Hossein Manshaei, Thierry Turletti
+ *  INRIA Sophia - Projet Planete
+ *  http://www-sop.inria.fr/rapports/sophia/RR-5208.html
+ */
+#include <sys/param.h>
+#include <sys/kernel.h>
+#include <sys/module.h>
+#include <sys/socket.h>
+#include <sys/sysctl.h>
+
+#include <net/if.h>
+#include <net/if_media.h>
+
+#ifdef INET
+#include <netinet/in.h>
+#include <netinet/if_ether.h>
+#endif
+
+#include <net80211/ieee80211.h>
+#include <net80211/ieee80211_var.h>
+#include <net80211/ieee80211_amrr.h>
+
+#define is_success(amn)	\
+	((amn)->amn_retrycnt < (amn)->amn_txcnt / 10)
+#define is_failure(amn)	\
+	((amn)->amn_retrycnt > (amn)->amn_txcnt / 3)
+#define is_enough(amn)		\
+	((amn)->amn_txcnt > 10)
+#define is_min_rate(ni)		\
+	((ni)->ni_txrate == 0)
+#define is_max_rate(ni)		\
+	((ni)->ni_txrate == (ni)->ni_rates.rs_nrates - 1)
+#define increase_rate(ni)	\
+	((ni)->ni_txrate++)
+#define decrease_rate(ni)	\
+	((ni)->ni_txrate--)
+#define reset_cnt(amn)		\
+	do { (amn)->amn_txcnt = (amn)->amn_retrycnt = 0; } while (0)
+
+void
+ieee80211_amrr_init(struct ieee80211_amrr *amrr,
+    struct ieee80211com *ic, int min, int max)
+{
+	/* XXX bounds check? */
+	amrr->amrr_min_success_threshold = min;
+	amrr->amrr_max_success_threshold = max;
+	amrr->amrr_ic = ic;
+}
+
+void
+ieee80211_amrr_node_init(struct ieee80211_amrr *amrr,
+    struct ieee80211_amrr_node *amn)
+{
+	amn->amn_success = 0;
+	amn->amn_recovery = 0;
+	amn->amn_txcnt = amn->amn_retrycnt = 0;
+	amn->amn_success_threshold = amrr->amrr_min_success_threshold;
+}
+
+/*
+ * Update ni->ni_txrate.
+ */
+void
+ieee80211_amrr_choose(struct ieee80211_amrr *amrr, struct ieee80211_node *ni,
+    struct ieee80211_amrr_node *amn)
+{
+	int need_change = 0;
+
+	if (is_success(amn) && is_enough(amn)) {
+		amn->amn_success++;
+		if (amn->amn_success >= amn->amn_success_threshold &&
+		    !is_max_rate(ni)) {
+			amn->amn_recovery = 1;
+			amn->amn_success = 0;
+			increase_rate(ni);
+			IEEE80211_DPRINTF(amrr->amrr_ic, IEEE80211_MSG_RATECTL,
+			    "AMRR increasing rate %d (txcnt=%d "
+			    "retrycnt=%d)\n",
+			    ni->ni_rates.rs_rates[ni->ni_txrate] &
+				IEEE80211_RATE_VAL,
+			    amn->amn_txcnt, amn->amn_retrycnt);
+			need_change = 1;
+		} else {
+			amn->amn_recovery = 0;
+		}
+	} else if (is_failure(amn)) {
+		amn->amn_success = 0;
+		if (!is_min_rate(ni)) {
+			if (amn->amn_recovery) {
+				amn->amn_success_threshold *= 2;
+				if (amn->amn_success_threshold >
+				    amrr->amrr_max_success_threshold)
+					amn->amn_success_threshold =
+					    amrr->amrr_max_success_threshold;
+			} else {
+				amn->amn_success_threshold =
+				    amrr->amrr_min_success_threshold;
+			}
+			decrease_rate(ni);
+			IEEE80211_DPRINTF(amrr->amrr_ic, IEEE80211_MSG_RATECTL,
+			    "AMRR decreasing rate %d (txcnt=%d "
+			    "retrycnt=%d)\n",
+			    ni->ni_rates.rs_rates[ni->ni_txrate] &
+				IEEE80211_RATE_VAL,
+			    amn->amn_txcnt, amn->amn_retrycnt);
+			need_change = 1;
+		}
+		amn->amn_recovery = 0;
+	}
+
+	if (is_enough(amn) || need_change)
+		reset_cnt(amn);
+}
+
+/*
+ * Module glue.
+ */
+static int
+amrr_modevent(module_t mod, int type, void *unused)
+{
+	switch (type) {
+	case MOD_LOAD:
+		if (bootverbose)
+			printf("wlan_amrr: <AMRR Transmit Rate Control Algorithm>\n");
+		return 0;
+	case MOD_UNLOAD:
+		return 0;
+	}
+	return EINVAL;
+}
+
+static moduledata_t amrr_mod = {
+	"wlan_amrr",
+	amrr_modevent,
+	0
+};
+DECLARE_MODULE(wlan_amrr, amrr_mod, SI_SUB_DRIVERS, SI_ORDER_FIRST);
+MODULE_VERSION(wlan_amrr, 1);
diff --git a/sys/net80211/ieee80211_amrr.h b/sys/net80211/ieee80211_amrr.h
new file mode 100644
index 000000000000..947d6179be7f
--- /dev/null
+++ b/sys/net80211/ieee80211_amrr.h
@@ -0,0 +1,64 @@
+/* $FreeBSD$ */
+/*	$OpenBSD: ieee80211_amrr.h,v 1.3 2006/06/17 19:34:31 damien Exp $	*/
+
+/*-
+ * Copyright (c) 2006
+ *	Damien Bergamini <damien.bergamini@free.fr>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+#ifndef _NET80211_IEEE80211_AMRR_H_
+#define _NET80211_IEEE80211_AMRR_H_
+
+/*-
+ * Naive implementation of the Adaptive Multi Rate Retry algorithm:
+ *
+ * "IEEE 802.11 Rate Adaptation: A Practical Approach"
+ *  Mathieu Lacage, Hossein Manshaei, Thierry Turletti
+ *  INRIA Sophia - Projet Planete
+ *  http://www-sop.inria.fr/rapports/sophia/RR-5208.html
+ */
+
+/*
+ * Rate control settings.
+ */
+struct ieee80211com;
+
+struct ieee80211_amrr {
+	u_int	amrr_min_success_threshold;
+	u_int	amrr_max_success_threshold;
+	struct ieee80211com *amrr_ic;
+};
+
+#define IEEE80211_AMRR_MIN_SUCCESS_THRESHOLD	 1
+#define IEEE80211_AMRR_MAX_SUCCESS_THRESHOLD	15
+
+/*
+ * Rate control state for a given node.
+ */
+struct ieee80211_amrr_node {
+	u_int	amn_success;
+	u_int	amn_recovery;
+	u_int	amn_success_threshold;
+	u_int	amn_txcnt;
+	u_int	amn_retrycnt;
+};
+
+void	ieee80211_amrr_init(struct ieee80211_amrr *,
+	    struct ieee80211com *ic, int, int);
+void	ieee80211_amrr_node_init(struct ieee80211_amrr *,
+	    struct ieee80211_amrr_node *);
+void	ieee80211_amrr_choose(struct ieee80211_amrr *, struct ieee80211_node *,
+	    struct ieee80211_amrr_node *);
+
+#endif /* _NET80211_IEEE80211_AMRR_H_ */