From 1e49c82c0ee6b6537e8c380ed41a7d31f0e48f5f Mon Sep 17 00:00:00 2001
From: Sepherosa Ziehau <sephe@dragonflybsd.org>
Date: Sun, 1 Apr 2007 13:59:41 +0000
Subject: [PATCH] - Define 802.11 modulation types as 'enum ieee80211_modtype'.
 - Expose ieee80211_rate2modtype() for pubic use. - Add definition for DIFS,
 slot time and contention window. - Add addition field in TX rate control
 state structure, so drivers can   give hints to TX rate control algorithms
 about their capabilities. - Add Sample TX rate control support:  
 http://www.pdos.lcs.mit.edu/papers/jbicket-ms.pdf   It is factored out and
 adapted from the one in ath(4). - In ieee80211_ratectl.h, expose only
 IEEE80211_RATECTL_{ONOE,AMRR,SAMPLE}   for user space program. - Teach
 ifconfig(8) to show and set Sample TX rate control algorithm. - Fix a node
 leakage on rt2560_tx_mgt() error handling path. - Support Onoe and Sample TX
 rate control algorithm in 2560 part of   ral(4), and use Sample TX rate
 control algorithm as the default TX   rate control algorithm. [*] - Make
 ral(4) depend on wlan_ratectl_{onoe,sample}. - Hook Sample TX rate control
 algorithm into GENERIC and LINT.

# [*]
# If Sample TX rate control algorithm is used, I get almost 100~200%
# UDP_STREAM netperf TX performance boost than the original TX rate
# control algorithm in open/noisy enviroments, and +200~500Kbits/s
# UDP_STREAM netperf TX performance boost under good conditions.
---
 sbin/ifconfig/ifieee80211.c                        |   7 +-
 sys/conf/files                                     |   3 +-
 sys/config/GENERIC                                 |   5 +-
 sys/config/LINT                                    |   5 +-
 sys/dev/netif/ral/Makefile                         |   4 +-
 sys/dev/netif/ral/if_ral_pci.c                     |   4 +-
 sys/dev/netif/ral/rt2560.c                         | 176 ++--
 sys/dev/netif/ral/rt2560var.h                      |  10 +-
 sys/netproto/802_11/_ieee80211.h                   |   9 +-
 sys/netproto/802_11/ieee80211.h                    |  27 +-
 sys/netproto/802_11/ieee80211_ratectl.h            |  18 +-
 sys/netproto/802_11/ieee80211_var.h                |   3 +-
 sys/netproto/802_11/wlan/ieee80211.c               |  15 +-
 sys/netproto/802_11/wlan/ieee80211_output.c        |  27 +-
 sys/netproto/802_11/wlan/ieee80211_ratectl.c       |   5 +-
 sys/netproto/802_11/wlan_ratectl/Makefile          |   4 +-
 sys/netproto/802_11/wlan_ratectl/sample/Makefile   |   7 +
 .../wlan_ratectl/sample/ieee80211_ratectl_sample.c | 884 +++++++++++++++++++++
 .../wlan_ratectl/sample/ieee80211_ratectl_sample.h |  92 +++
 19 files changed, 1144 insertions(+), 161 deletions(-)
 create mode 100644 sys/netproto/802_11/wlan_ratectl/sample/Makefile
 create mode 100644 sys/netproto/802_11/wlan_ratectl/sample/ieee80211_ratectl_sample.c
 create mode 100644 sys/netproto/802_11/wlan_ratectl/sample/ieee80211_ratectl_sample.h

diff --git a/sbin/ifconfig/ifieee80211.c b/sbin/ifconfig/ifieee80211.c
index aeecd21df6..917ed63257 100644
--- a/sbin/ifconfig/ifieee80211.c
+++ b/sbin/ifconfig/ifieee80211.c
@@ -25,7 +25,7 @@
  * SUCH DAMAGE.
  *
  * $FreeBSD: src/sbin/ifconfig/ifieee80211.c,v 1.18.2.10 2006/08/10 06:09:23 sam Exp $
- * $DragonFly: src/sbin/ifconfig/ifieee80211.c,v 1.17 2006/12/08 15:25:07 sephe Exp $
+ * $DragonFly: src/sbin/ifconfig/ifieee80211.c,v 1.18 2007/04/01 13:59:40 sephe Exp $
  */
 
 /*-
@@ -680,6 +680,8 @@ set80211ratectl(const char *val, int d, int s, const struct afswtch *rafp)
 		ratectl = IEEE80211_RATECTL_ONOE;
 	else if (strcmp("amrr", val) == 0)
 		ratectl = IEEE80211_RATECTL_AMRR;
+	else if (strcmp("sample", val) == 0)
+		ratectl = IEEE80211_RATECTL_SAMPLE;
 	else
 		errx(1, "unknown ratectl");
 
@@ -1501,6 +1503,9 @@ ieee80211_status(int s)
 		case IEEE80211_RATECTL_AMRR:
 			printf("\tratectl: amrr");
 			break;
+		case IEEE80211_RATECTL_SAMPLE:
+			printf("\tratectl: sample");
+			break;
 		default:
 			if (verbose)
 				printf("\tratectl: none");
diff --git a/sys/conf/files b/sys/conf/files
index 6222e40629..a55d4819ad 100644
--- a/sys/conf/files
+++ b/sys/conf/files
@@ -1,5 +1,5 @@
 # $FreeBSD: src/sys/conf/files,v 1.340.2.137 2003/06/04 17:10:30 sam Exp $
-# $DragonFly: src/sys/conf/files,v 1.152 2007/02/11 02:51:28 swildner Exp $
+# $DragonFly: src/sys/conf/files,v 1.153 2007/04/01 13:59:41 sephe Exp $
 #
 # The long compile-with and dependency lines are required because of
 # limitations in config: backslash-newline doesn't work in strings, and
@@ -755,6 +755,7 @@ netproto/802_11/wlan_wep/ieee80211_crypto_wep.c		optional wlan_wep
 netproto/802_11/wlan_xauth/ieee80211_xauth.c		optional wlan_xauth
 netproto/802_11/wlan_ratectl/onoe/ieee80211_ratectl_onoe.c	optional wlan_ratectl_onoe
 netproto/802_11/wlan_ratectl/amrr/ieee80211_ratectl_amrr.c	optional wlan_ratectl_amrr
+netproto/802_11/wlan_ratectl/sample/ieee80211_ratectl_sample.c	optional wlan_ratectl_sample
 netproto/atalk/aarp.c		optional netatalk
 netproto/atalk/at_control.c	optional netatalk
 netproto/atalk/at_proto.c	optional netatalk
diff --git a/sys/config/GENERIC b/sys/config/GENERIC
index fed247c609..65e368b5d9 100644
--- a/sys/config/GENERIC
+++ b/sys/config/GENERIC
@@ -4,7 +4,7 @@
 # Check the LINT configuration file in sys/config, for an
 # exhaustive list of options.
 #
-# $DragonFly: src/sys/config/GENERIC,v 1.48 2007/01/19 08:23:42 dillon Exp $
+# $DragonFly: src/sys/config/GENERIC,v 1.49 2007/04/01 13:59:41 sephe Exp $
 
 platform	pc32
 machine		i386
@@ -228,6 +228,7 @@ device		wlan_wep	# 802.11 WEP support
 # 802.11 TX rate control algorithms
 #device		wlan_ratectl_amrr	# AMRR
 device		wlan_ratectl_onoe	# Onoe
+device		wlan_ratectl_sample	# Sample
 
 # Aironet 4500/4800 802.11 wireless NICs.  Note: the declaration below will
 # work for PCMCIA and PCI cards, as well as ISA cards set to ISA PnP
@@ -237,6 +238,8 @@ device		wlan_ratectl_onoe	# Onoe
 device		an
 device		awi		# PRISM I IEEE 802.11b wireless NIC
 device		ral		# Ralink Technology 802.11 wireless NIC
+				# Requires wlan_ratectl_onoe and
+				# wlan_ratectl_sample
 device		rtw		# RealTek 802.11 wireless NIC
 				# Requires wlan_ratectl_onoe and wlan_wep
 # WaveLAN/IEEE 802.11 wireless NICs.  Note: the WaveLAN/IEEE really
diff --git a/sys/config/LINT b/sys/config/LINT
index bdcf52de6c..86e23aa1ad 100644
--- a/sys/config/LINT
+++ b/sys/config/LINT
@@ -3,7 +3,7 @@
 #	as much of the source tree as it can.
 #
 # $FreeBSD: src/sys/i386/conf/LINT,v 1.749.2.144 2003/06/04 17:56:59 sam Exp $
-# $DragonFly: src/sys/config/LINT,v 1.108 2007/03/17 21:24:11 swildner Exp $
+# $DragonFly: src/sys/config/LINT,v 1.109 2007/04/01 13:59:41 sephe Exp $
 #
 # NB: You probably don't want to try running a kernel built from this
 # file.  Instead, you should start from GENERIC, and add options from
@@ -1426,6 +1426,7 @@ device		wlan_wep	# 802.11 WEP support
 device		wlan_xauth	# 802.11 WPA or 802.1x authentication for AP
 device		wlan_ratectl_onoe # 802.11 Onoe TX rate control algorithm
 device		wlan_ratectl_amrr # 802.11 AMRR TX rate control algorithm
+device		wlan_ratectl_sample # 802.11 Sample TX rate control algorithm
 options 	WLCACHE		# enables the signal-strength cache
 options 	WLDEBUG		# enables verbose debugging output
 device		awi		# AMD PCnetMobile
@@ -1442,6 +1443,8 @@ device wl0 at isa? port 0x300	# T1 speed ISA/radio lan
 device		xe		# Xircom PCMCIA
 device		ray		# Raytheon Raylink/Webgear Aviator
 device		ral		# Ralink Technology 802.11 wireless NIC
+				# Requires wlan_ratectl_onoe and
+				# wlan_ratectl_sample
 
 device oltr0 at isa?
 
diff --git a/sys/dev/netif/ral/Makefile b/sys/dev/netif/ral/Makefile
index 7635f65d34..d556c26aab 100644
--- a/sys/dev/netif/ral/Makefile
+++ b/sys/dev/netif/ral/Makefile
@@ -1,7 +1,9 @@
-# $DragonFly: src/sys/dev/netif/ral/Makefile,v 1.1 2006/05/20 11:13:09 sephe Exp $
+# $DragonFly: src/sys/dev/netif/ral/Makefile,v 1.2 2007/04/01 13:59:40 sephe Exp $
 KMOD	= if_ral
 
 SRCS	= if_ral_pci.c if_ralrate.c rt2560.c rt2661.c
 SRCS	+= device_if.h bus_if.h pci_if.h
 
+KMODDEPS= wlan wlan_ratectl_onoe wlan_ratectl_sample
+
 .include <bsd.kmod.mk>
diff --git a/sys/dev/netif/ral/if_ral_pci.c b/sys/dev/netif/ral/if_ral_pci.c
index 0ad9d07fa1..5d6a482c08 100644
--- a/sys/dev/netif/ral/if_ral_pci.c
+++ b/sys/dev/netif/ral/if_ral_pci.c
@@ -15,7 +15,7 @@
  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  *
  * $FreeBSD: src/sys/dev/ral/if_ral_pci.c,v 1.4 2006/03/05 23:27:51 silby Exp $
- * $DragonFly: src/sys/dev/netif/ral/if_ral_pci.c,v 1.3 2006/10/25 22:55:58 dillon Exp $
+ * $DragonFly: src/sys/dev/netif/ral/if_ral_pci.c,v 1.4 2007/04/01 13:59:40 sephe Exp $
  */
 
 /*
@@ -138,6 +138,8 @@ DRIVER_MODULE(ral, pci, ral_pci_driver, ral_devclass, 0, 0);
 DRIVER_MODULE(ral, cardbus, ral_pci_driver, ral_devclass, 0, 0);
 
 MODULE_DEPEND(ral, wlan, 1, 1, 1);
+MODULE_DEPEND(ral, wlan_ratectl_onoe, 1, 1, 1);
+MODULE_DEPEND(ral, wlan_ratectl_sample, 1, 1, 1);
 MODULE_DEPEND(ral, pci, 1, 1, 1);
 MODULE_DEPEND(ral, cardbus, 1, 1, 1);
 
diff --git a/sys/dev/netif/ral/rt2560.c b/sys/dev/netif/ral/rt2560.c
index 1f621e6b02..c95fdb663a 100644
--- a/sys/dev/netif/ral/rt2560.c
+++ b/sys/dev/netif/ral/rt2560.c
@@ -15,7 +15,7 @@
  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  *
  * $FreeBSD: src/sys/dev/ral/rt2560.c,v 1.3 2006/03/21 21:15:43 damien Exp $
- * $DragonFly: src/sys/dev/netif/ral/rt2560.c,v 1.12 2007/03/30 11:39:33 sephe Exp $
+ * $DragonFly: src/sys/dev/netif/ral/rt2560.c,v 1.13 2007/04/01 13:59:40 sephe Exp $
  */
 
 /*
@@ -47,7 +47,6 @@
 #include <netproto/802_11/ieee80211_var.h>
 #include <netproto/802_11/ieee80211_radiotap.h>
 
-#include <dev/netif/ral/if_ralrate.h>
 #include <dev/netif/ral/rt2560reg.h>
 #include <dev/netif/ral/rt2560var.h>
 
@@ -80,12 +79,8 @@ static void		rt2560_reset_rx_ring(struct rt2560_softc *,
 			    struct rt2560_rx_ring *);
 static void		rt2560_free_rx_ring(struct rt2560_softc *,
 			    struct rt2560_rx_ring *);
-static struct		ieee80211_node *rt2560_node_alloc(
-			    struct ieee80211_node_table *);
 static int		rt2560_media_change(struct ifnet *);
 static void		rt2560_next_scan(void *);
-static void		rt2560_iter_func(void *, struct ieee80211_node *);
-static void		rt2560_update_rssadapt(void *);
 static int		rt2560_newstate(struct ieee80211com *,
 			    enum ieee80211_state, int);
 static uint16_t		rt2560_eeprom_read(struct rt2560_softc *, uint8_t);
@@ -193,7 +188,6 @@ rt2560_attach(device_t dev, int id)
 	int error, i;
 
 	callout_init(&sc->scan_ch);
-	callout_init(&sc->rssadapt_ch);
 
 	sc->sc_irq_rid = 0;
 	sc->sc_irq = bus_alloc_resource_any(dev, SYS_RES_IRQ, &sc->sc_irq_rid,
@@ -274,6 +268,10 @@ rt2560_attach(device_t dev, int id)
 	ic->ic_opmode = IEEE80211_M_STA; /* default to BSS mode */
 	ic->ic_state = IEEE80211_S_INIT;
 
+	ic->ic_ratectl.rc_st_ratectl_cap = IEEE80211_RATECTL_CAP_ONOE |
+					   IEEE80211_RATECTL_CAP_SAMPLE;
+	ic->ic_ratectl.rc_st_ratectl = IEEE80211_RATECTL_SAMPLE;
+
 	/* set device capabilities */
 	ic->ic_caps =
 	    IEEE80211_C_IBSS |		/* IBSS mode supported */
@@ -323,7 +321,6 @@ rt2560_attach(device_t dev, int id)
 	sc->sc_sifs = IEEE80211_DUR_SIFS;	/* Default SIFS */
 
 	ieee80211_ifattach(ic);
-	ic->ic_node_alloc = rt2560_node_alloc;
 	ic->ic_updateslot = rt2560_update_slot;
 	ic->ic_reset = rt2560_reset;
 	/* enable s/w bmiss handling in sta mode */
@@ -391,7 +388,6 @@ rt2560_detach(void *xsc)
 		lwkt_serialize_enter(ifp->if_serializer);
 
 		callout_stop(&sc->scan_ch);
-		callout_stop(&sc->rssadapt_ch);
 
 		rt2560_stop(sc);
 		bus_teardown_intr(sc->sc_dev, sc->sc_irq, sc->sc_ih);
@@ -774,17 +770,6 @@ rt2560_free_rx_ring(struct rt2560_softc *sc, struct rt2560_rx_ring *ring)
 	}
 }
 
-static struct ieee80211_node *
-rt2560_node_alloc(struct ieee80211_node_table *nt)
-{
-	struct rt2560_node *rn;
-
-	rn = kmalloc(sizeof(struct rt2560_node), M_80211_NODE,
-	    M_NOWAIT | M_ZERO);
-
-	return (rn != NULL) ? &rn->ni : NULL;
-}
-
 static int
 rt2560_media_change(struct ifnet *ifp)
 {
@@ -817,36 +802,6 @@ rt2560_next_scan(void *arg)
 	lwkt_serialize_exit(ifp->if_serializer);
 }
 
-/*
- * This function is called for each node present in the node station table.
- */
-static void
-rt2560_iter_func(void *arg, struct ieee80211_node *ni)
-{
-	struct rt2560_node *rn = (struct rt2560_node *)ni;
-
-	ral_rssadapt_updatestats(&rn->rssadapt);
-}
-
-/*
- * This function is called periodically (every 100ms) in RUN state to update
- * the rate adaptation statistics.
- */
-static void
-rt2560_update_rssadapt(void *arg)
-{
-	struct rt2560_softc *sc = arg;
-	struct ieee80211com *ic = &sc->sc_ic;
-	struct ifnet *ifp = ic->ic_ifp;
-
-	lwkt_serialize_enter(ifp->if_serializer);
-
-	ieee80211_iterate_nodes(&ic->ic_sta, rt2560_iter_func, arg);
-	callout_reset(&sc->rssadapt_ch, hz / 10, rt2560_update_rssadapt, sc);
-
-	lwkt_serialize_exit(ifp->if_serializer);
-}
-
 static int
 rt2560_newstate(struct ieee80211com *ic, enum ieee80211_state nstate, int arg)
 {
@@ -858,11 +813,10 @@ rt2560_newstate(struct ieee80211com *ic, enum ieee80211_state nstate, int arg)
 
 	ostate = ic->ic_state;
 	callout_stop(&sc->scan_ch);
+	ieee80211_ratectl_newstate(ic, nstate);
 
 	switch (nstate) {
 	case IEEE80211_S_INIT:
-		callout_stop(&sc->rssadapt_ch);
-
 		if (ostate == IEEE80211_S_RUN) {
 			/* abort TSF synchronization */
 			RAL_WRITE(sc, RT2560_CSR14, 0);
@@ -916,12 +870,8 @@ rt2560_newstate(struct ieee80211com *ic, enum ieee80211_state nstate, int arg)
 		/* turn assocation led on */
 		rt2560_update_led(sc, 1, 0);
 
-		if (ic->ic_opmode != IEEE80211_M_MONITOR) {
-			callout_reset(&sc->rssadapt_ch, hz / 10,
-			    rt2560_update_rssadapt, sc);
-
+		if (ic->ic_opmode != IEEE80211_M_MONITOR)
 			rt2560_enable_tsf_sync(sc);
-		}
 		break;
 	}
 
@@ -1038,65 +988,84 @@ rt2560_tx_intr(struct rt2560_softc *sc)
 {
 	struct ieee80211com *ic = &sc->sc_ic;
 	struct ifnet *ifp = ic->ic_ifp;
-	struct rt2560_tx_desc *desc;
-	struct rt2560_tx_data *data;
-	struct rt2560_node *rn;
 
 	bus_dmamap_sync(sc->txq.desc_dmat, sc->txq.desc_map,
 	    BUS_DMASYNC_POSTREAD);
 
 	for (;;) {
+		struct rt2560_tx_desc *desc;
+		struct rt2560_tx_data *data;
+		struct ieee80211_node *ni;
+		int rateidx, data_retries, failed;
+		struct mbuf *m;
+		uint32_t flags;
+
 		desc = &sc->txq.desc[sc->txq.next];
 		data = &sc->txq.data[sc->txq.next];
 
-		if ((le32toh(desc->flags) & RT2560_TX_BUSY) ||
-		    (le32toh(desc->flags) & RT2560_TX_CIPHER_BUSY) ||
-		    !(le32toh(desc->flags) & RT2560_TX_VALID))
+		flags = le32toh(desc->flags);
+
+		if ((flags & RT2560_TX_BUSY) ||
+		    (flags & RT2560_TX_CIPHER_BUSY) ||
+		    !(flags & RT2560_TX_VALID))
 			break;
 
-		rn = (struct rt2560_node *)data->ni;
+		rateidx = data->rateidx;
+		ni = data->ni;
+		m = data->m;
 
-		switch (le32toh(desc->flags) & RT2560_TX_RESULT_MASK) {
+		data->ni = NULL;
+		data->m = NULL;
+
+		failed = 0;
+		switch (flags & RT2560_TX_RESULT_MASK) {
 		case RT2560_TX_SUCCESS:
 			DPRINTFN(10, ("data frame sent successfully\n"));
-			if (data->id.id_node != NULL) {
-				ral_rssadapt_raise_rate(ic, &rn->rssadapt,
-				    &data->id);
-			}
 			ifp->if_opackets++;
+			data_retries = 0;
 			break;
 
 		case RT2560_TX_SUCCESS_RETRY:
+			data_retries = (flags >> 5) & 0x7;
 			DPRINTFN(9, ("data frame sent after %u retries\n",
-			    (le32toh(desc->flags) >> 5) & 0x7));
+				 data_retries));
 			ifp->if_opackets++;
 			break;
 
 		case RT2560_TX_FAIL_RETRY:
 			DPRINTFN(9, ("sending data frame failed (too much "
 			    "retries)\n"));
-			if (data->id.id_node != NULL) {
-				ral_rssadapt_lower_rate(ic, data->ni,
-				    &rn->rssadapt, &data->id);
-			}
 			ifp->if_oerrors++;
+			data_retries = 7;
+			failed = 1;
 			break;
 
 		case RT2560_TX_FAIL_INVALID:
 		case RT2560_TX_FAIL_OTHER:
 		default:
+			data_retries = 7;
+			failed = 1;
 			device_printf(sc->sc_dev, "sending data frame failed "
-			    "0x%08x\n", le32toh(desc->flags));
+			    "0x%08x\n", flags);
 			ifp->if_oerrors++;
+			break;
 		}
 
 		bus_dmamap_sync(sc->txq.data_dmat, data->map,
 		    BUS_DMASYNC_POSTWRITE);
 		bus_dmamap_unload(sc->txq.data_dmat, data->map);
-		m_freem(data->m);
-		data->m = NULL;
-		ieee80211_free_node(data->ni);
-		data->ni = NULL;
+
+		if (rateidx >= 0) {
+			struct ieee80211_ratectl_res res;
+
+			res.rc_res_tries = data_retries + 1;
+			res.rc_res_rateidx = rateidx;
+			ieee80211_ratectl_tx_complete(ni, m->m_pkthdr.len,
+				&res, 1, data_retries, 0, failed);
+		}
+
+		m_freem(m);
+		ieee80211_free_node(ni);
 
 		/* descriptor is no longer valid */
 		desc->flags &= ~htole32(RT2560_TX_VALID);
@@ -1161,8 +1130,8 @@ rt2560_prio_intr(struct rt2560_softc *sc)
 		bus_dmamap_unload(sc->prioq.data_dmat, data->map);
 		m_freem(data->m);
 		data->m = NULL;
-		ieee80211_free_node(data->ni);
-		data->ni = NULL;
+
+		KASSERT(data->ni == NULL, ("mgmt node is not empty\n"));
 
 		/* descriptor is no longer valid */
 		desc->flags &= ~htole32(RT2560_TX_VALID);
@@ -1195,7 +1164,6 @@ rt2560_decryption_intr(struct rt2560_softc *sc)
 	bus_addr_t physaddr;
 	struct ieee80211_frame *wh;
 	struct ieee80211_node *ni;
-	struct rt2560_node *rn;
 	struct mbuf *mnew, *m;
 	int hw, error;
 
@@ -1301,11 +1269,6 @@ rt2560_decryption_intr(struct rt2560_softc *sc)
 		/* send the frame to the 802.11 layer */
 		ieee80211_input(ic, m, ni, RT2560_RSSI(sc, desc->rssi), 0);
 
-		/* give rssi to the rate adatation algorithm */
-		rn = (struct rt2560_node *)ni;
-		ral_rssadapt_input(ic, ni, &rn->rssadapt,
-				   RT2560_RSSI(sc, desc->rssi));
-
 		/* node is no longer needed */
 		ieee80211_free_node(ni);
 
@@ -1651,6 +1614,7 @@ rt2560_tx_mgt(struct rt2560_softc *sc, struct mbuf *m0,
 	if (error != 0) {
 		device_printf(sc->sc_dev, "could not map mbuf (error %d)\n",
 		    error);
+		ieee80211_free_node(ni);
 		m_freem(m0);
 		return error;
 	}
@@ -1668,7 +1632,7 @@ rt2560_tx_mgt(struct rt2560_softc *sc, struct mbuf *m0,
 	}
 
 	data->m = m0;
-	data->ni = ni;
+	data->ni = NULL;
 
 	wh = mtod(m0, struct ieee80211_frame *);
 
@@ -1701,6 +1665,8 @@ rt2560_tx_mgt(struct rt2560_softc *sc, struct mbuf *m0,
 	sc->prioq.cur = (sc->prioq.cur + 1) % RT2560_PRIO_RING_COUNT;
 	RAL_WRITE(sc, RT2560_TXCSR0, RT2560_KICK_PRIO);
 
+	ieee80211_free_node(ni);
+
 	return 0;
 }
 
@@ -1742,30 +1708,15 @@ rt2560_tx_data(struct rt2560_softc *sc, struct mbuf *m0,
 	struct ieee80211com *ic = &sc->sc_ic;
 	struct rt2560_tx_desc *desc;
 	struct rt2560_tx_data *data;
-	struct rt2560_node *rn;
-	struct ieee80211_rateset *rs;
 	struct ieee80211_frame *wh;
 	struct ieee80211_key *k;
 	struct mbuf *mnew;
 	bus_addr_t paddr;
 	uint16_t dur;
 	uint32_t flags = 0;
-	int rate, error, ackrate;
+	int rate, error, ackrate, rateidx;
 
 	wh = mtod(m0, struct ieee80211_frame *);
-
-	if (ic->ic_fixed_rate != IEEE80211_FIXED_RATE_NONE) {
-		rs = &ic->ic_sup_rates[ic->ic_curmode];
-		rate = rs->rs_rates[ic->ic_fixed_rate];
-	} else {
-		rs = &ni->ni_rates;
-		rn = (struct rt2560_node *)ni;
-		ni->ni_txrate = ral_rssadapt_choose(&rn->rssadapt, rs, wh,
-		    m0->m_pkthdr.len, NULL, 0);
-		rate = rs->rs_rates[ni->ni_txrate];
-	}
-	rate &= IEEE80211_RATE_VAL;
-
 	if (wh->i_fc[1] & IEEE80211_FC1_WEP) {
 		k = ieee80211_crypto_encap(ic, ni, m0);
 		if (k == NULL) {
@@ -1777,6 +1728,9 @@ rt2560_tx_data(struct rt2560_softc *sc, struct mbuf *m0,
 		wh = mtod(m0, struct ieee80211_frame *);
 	}
 
+	ieee80211_ratectl_findrate(ni, m0->m_pkthdr.len, &rateidx, 1);
+	rate = IEEE80211_RS_RATE(&ni->ni_rates, rateidx);
+
 	ackrate = ieee80211_ack_rate(ni, rate);
 
 	/*
@@ -1817,9 +1771,7 @@ rt2560_tx_data(struct rt2560_softc *sc, struct mbuf *m0,
 
 		data->m = m;
 		data->ni = ni;
-
-		/* RTS frames are not taken into account for rssadapt */
-		data->id.id_node = NULL;
+		data->rateidx = -1;	/* don't count RTS */
 
 		rt2560_setup_tx_desc(sc, desc, RT2560_TX_ACK |
 		    RT2560_TX_MORE_FRAG, m->m_pkthdr.len, rtsrate, 1, paddr);
@@ -1888,15 +1840,7 @@ rt2560_tx_data(struct rt2560_softc *sc, struct mbuf *m0,
 
 	data->m = m0;
 	data->ni = ni;
-
-	/* remember link conditions for rate adaptation algorithm */
-	if (ic->ic_fixed_rate == IEEE80211_FIXED_RATE_NONE) {
-		data->id.id_len = m0->m_pkthdr.len;
-		data->id.id_rateidx = ni->ni_txrate;
-		data->id.id_node = ni;
-		data->id.id_rssi = ni->ni_rssi;
-	} else
-		data->id.id_node = NULL;
+	data->rateidx = rateidx;
 
 	if (!IEEE80211_IS_MULTICAST(wh->i_addr1)) {
 		flags |= RT2560_TX_ACK;
diff --git a/sys/dev/netif/ral/rt2560var.h b/sys/dev/netif/ral/rt2560var.h
index 5a86973ab3..3666dd8f89 100644
--- a/sys/dev/netif/ral/rt2560var.h
+++ b/sys/dev/netif/ral/rt2560var.h
@@ -15,7 +15,7 @@
  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  *
  * $FreeBSD: src/sys/dev/ral/rt2560var.h,v 1.1 2006/03/05 20:36:56 damien Exp $
- * $DragonFly: src/sys/dev/netif/ral/rt2560var.h,v 1.3 2007/03/30 11:39:33 sephe Exp $
+ * $DragonFly: src/sys/dev/netif/ral/rt2560var.h,v 1.4 2007/04/01 13:59:40 sephe Exp $
  */
 
 struct rt2560_rx_radiotap_header {
@@ -56,7 +56,7 @@ struct rt2560_tx_data {
 	bus_dmamap_t			map;
 	struct mbuf			*m;
 	struct ieee80211_node		*ni;
-	struct ral_rssdesc		id;
+	int				rateidx;
 };
 
 struct rt2560_tx_ring {
@@ -93,11 +93,6 @@ struct rt2560_rx_ring {
 	int			cur_decrypt;
 };
 
-struct rt2560_node {
-	struct ieee80211_node	ni;
-	struct ral_rssadapt	rssadapt;
-};
-
 struct rt2560_softc {
 	/*
 	 * NOTE: following four fields MUST be in the
@@ -116,7 +111,6 @@ struct rt2560_softc {
 				    enum ieee80211_state, int);
 
 	struct callout		scan_ch;
-	struct callout		rssadapt_ch;
 
 	int			sc_tx_timer;
 	int			sc_sifs;
diff --git a/sys/netproto/802_11/_ieee80211.h b/sys/netproto/802_11/_ieee80211.h
index 8d9e5e2a6a..ed77bee94f 100644
--- a/sys/netproto/802_11/_ieee80211.h
+++ b/sys/netproto/802_11/_ieee80211.h
@@ -30,7 +30,7 @@
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
  * $FreeBSD: src/sys/net80211/_ieee80211.h,v 1.2.2.1 2005/09/03 22:40:02 sam Exp $
- * $DragonFly: src/sys/netproto/802_11/_ieee80211.h,v 1.1 2006/05/18 15:51:46 sephe Exp $
+ * $DragonFly: src/sys/netproto/802_11/_ieee80211.h,v 1.2 2007/04/01 13:59:40 sephe Exp $
  */
 #ifndef _NET80211__IEEE80211_H_
 #define _NET80211__IEEE80211_H_
@@ -63,6 +63,13 @@ enum ieee80211_opmode {
 	IEEE80211_M_MONITOR	= 8	/* Monitor mode */
 };
 
+enum ieee80211_modtype {
+	IEEE80211_MODTYPE_DS	= 0,	/* DS/CCK modulation */
+	IEEE80211_MODTYPE_PBCC	= 1,	/* PBCC modulation */
+	IEEE80211_MODTYPE_OFDM	= 2	/* OFDM modulation */
+};
+#define IEEE80211_MODTYPE_CCK	IEEE80211_MODTYPE_DS
+
 /*
  * 802.11g protection mode.
  */
diff --git a/sys/netproto/802_11/ieee80211.h b/sys/netproto/802_11/ieee80211.h
index 53ebc399de..1d1a53dc84 100644
--- a/sys/netproto/802_11/ieee80211.h
+++ b/sys/netproto/802_11/ieee80211.h
@@ -30,7 +30,7 @@
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
  * $FreeBSD: src/sys/net80211/ieee80211.h,v 1.9.2.2 2006/08/10 06:07:49 sam Exp $
- * $DragonFly: src/sys/netproto/802_11/ieee80211.h,v 1.6 2007/03/30 11:39:34 sephe Exp $
+ * $DragonFly: src/sys/netproto/802_11/ieee80211.h,v 1.7 2007/04/01 13:59:40 sephe Exp $
  */
 #ifndef _NET80211_IEEE80211_H_
 #define _NET80211_IEEE80211_H_
@@ -666,10 +666,29 @@ enum {
 #define IEEE80211_HWBMISS_MAX   255
 
 /*
- * IFS (microseconds)
+ * Contention window (slots).
  */
-#define IEEE80211_DUR_SIFS	10	/* DS/CCK/ERP-OFDM SIFS (11b/g) */
-#define IEEE80211_DUR_OFDM_SIFS	16	/* OFDM SIFS (11a) */
+#define IEEE80211_CW_MAX	1023	/* aCWmax */
+#define IEEE80211_CW_MIN_0	31	/* DS/CCK aCWmin, ERP aCWmin(0) */
+#define IEEE80211_CW_MIN_1	15	/* OFDM aCWmin, ERP aCWmin(1) */
+
+/*
+ * SIFS (microseconds).
+ */
+#define IEEE80211_DUR_SIFS	10	/* DS/CCK/ERP SIFS */
+#define IEEE80211_DUR_OFDM_SIFS	16	/* OFDM SIFS */
+
+/*
+ * Slot time (microseconds).
+ */
+#define IEEE80211_DUR_SLOT	20	/* DS/CCK slottime, ERP long slottime */
+#define IEEE80211_DUR_SHSLOT	9	/* ERP short slottime */
+#define IEEE80211_DUR_OFDM_SLOT	9	/* OFDM slottime */
+
+/*
+ * DIFS (microseconds).
+ */
+#define IEEE80211_DUR_DIFS(sifs, slot)	((sifs) + 2 * (slot))
 
 #define IEEE80211_MGT_SUBTYPE_NAMES {			\
 	"assoc-req",		"assoc-resp",		\
diff --git a/sys/netproto/802_11/ieee80211_ratectl.h b/sys/netproto/802_11/ieee80211_ratectl.h
index 40ff1c379d..ffce538b8b 100644
--- a/sys/netproto/802_11/ieee80211_ratectl.h
+++ b/sys/netproto/802_11/ieee80211_ratectl.h
@@ -31,17 +31,20 @@
  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  * 
- * $DragonFly: src/sys/netproto/802_11/ieee80211_ratectl.h,v 1.4 2007/03/18 11:49:32 sephe Exp $
+ * $DragonFly: src/sys/netproto/802_11/ieee80211_ratectl.h,v 1.5 2007/04/01 13:59:40 sephe Exp $
  */
 
 #ifndef _NET80211_IEEE80211_RATECTL_H
 #define _NET80211_IEEE80211_RATECTL_H
 
+#ifdef _KERNEL
+
 struct ieee80211_ratectl_stats;
 
 struct ieee80211_ratectl_state {
 	void		*rc_st_ctx;
 	void		*rc_st_param;
+	uint32_t	rc_st_flags;	   /* see IEEE80211_RATECTL_F_ */
 	u_int		rc_st_ratectl;	   /* see IEEE80211_RATECTL_ */
 	uint32_t	rc_st_ratectl_cap; /* see IEEE80211_RATECTL_CAP_ */
 	uint64_t	rc_st_valid_stats; /* see IEEE80211_RATECTL_STATS_ */
@@ -51,6 +54,9 @@ struct ieee80211_ratectl_state {
 				       struct ieee80211_ratectl_stats *);
 };
 
+#define IEEE80211_RATECTL_F_RSDESC	0x1 /* Rate set must be descendant. */
+#define IEEE80211_RATECTL_F_MRR		0x2 /* Support multi-rate-retry. */
+
 struct ieee80211_ratectl_res {
 	int		rc_res_rateidx;
 	int		rc_res_tries;
@@ -94,10 +100,15 @@ struct ieee80211_ratectl {
 				       int[], int);
 };
 
+#endif	/* _KERNEL */
+
 #define IEEE80211_RATECTL_NONE		0
 #define IEEE80211_RATECTL_ONOE		1
 #define IEEE80211_RATECTL_AMRR		2
-#define IEEE80211_RATECTL_MAX		3
+#define IEEE80211_RATECTL_SAMPLE	3
+#define IEEE80211_RATECTL_MAX		4
+
+#ifdef _KERNEL
 
 #define IEEE80211_RATECTL_CAP(v)	(1 << (v))
 
@@ -107,6 +118,7 @@ struct ieee80211_ratectl {
 #define IEEE80211_RATECTL_CAP_NONE	_IEEE80211_RATECTL_CAP(NONE)
 #define IEEE80211_RATECTL_CAP_ONOE	_IEEE80211_RATECTL_CAP(ONOE)
 #define IEEE80211_RATECTL_CAP_AMRR	_IEEE80211_RATECTL_CAP(AMRR)
+#define IEEE80211_RATECTL_CAP_SAMPLE	_IEEE80211_RATECTL_CAP(SAMPLE)
 
 extern const struct ieee80211_ratectl	ieee80211_ratectl_none;
 
@@ -131,4 +143,6 @@ void	ieee80211_ratectl_tx_complete(struct ieee80211_node *, int,
 void	ieee80211_ratectl_newassoc(struct ieee80211_node *, int);
 int	ieee80211_ratectl_findrate(struct ieee80211_node *, int, int[], int);
 
+#endif	/* _KERNEL */
+
 #endif	/* !_NET80211_IEEE80211_RATECTL_H */
diff --git a/sys/netproto/802_11/ieee80211_var.h b/sys/netproto/802_11/ieee80211_var.h
index f98c88d10e..96d7d285b7 100644
--- a/sys/netproto/802_11/ieee80211_var.h
+++ b/sys/netproto/802_11/ieee80211_var.h
@@ -30,7 +30,7 @@
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
  * $FreeBSD: src/sys/net80211/ieee80211_var.h,v 1.22.2.11 2006/03/13 03:05:48 sam Exp $
- * $DragonFly: src/sys/netproto/802_11/ieee80211_var.h,v 1.14 2007/03/05 14:17:36 sephe Exp $
+ * $DragonFly: src/sys/netproto/802_11/ieee80211_var.h,v 1.15 2007/04/01 13:59:40 sephe Exp $
  */
 #ifndef _NET80211_IEEE80211_VAR_H_
 #define _NET80211_IEEE80211_VAR_H_
@@ -324,6 +324,7 @@ u_int	ieee80211_ieee2mhz(u_int, u_int);
 int	ieee80211_setmode(struct ieee80211com *, enum ieee80211_phymode);
 enum ieee80211_phymode ieee80211_chan2mode(struct ieee80211com *,
 		struct ieee80211_channel *);
+enum ieee80211_modtype ieee80211_rate2modtype(uint8_t);
 
 uint8_t *ieee80211_add_ssid(uint8_t *, const uint8_t *, u_int);
 uint8_t *ieee80211_add_xrates(uint8_t *, const struct ieee80211_rateset *);
diff --git a/sys/netproto/802_11/wlan/ieee80211.c b/sys/netproto/802_11/wlan/ieee80211.c
index 8bb4baface..fe36847b84 100644
--- a/sys/netproto/802_11/wlan/ieee80211.c
+++ b/sys/netproto/802_11/wlan/ieee80211.c
@@ -30,7 +30,7 @@
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
  * $FreeBSD: src/sys/net80211/ieee80211.c,v 1.19.2.7 2006/03/11 19:25:23 sam Exp $
- * $DragonFly: src/sys/netproto/802_11/wlan/ieee80211.c,v 1.13 2007/03/24 08:39:03 sephe Exp $
+ * $DragonFly: src/sys/netproto/802_11/wlan/ieee80211.c,v 1.14 2007/04/01 13:59:41 sephe Exp $
  */
 
 /*
@@ -1083,3 +1083,16 @@ ieee80211_plcp2rate(uint8_t plcp, int ofdm)
 	}
 	return 0;
 }
+
+enum ieee80211_modtype
+ieee80211_rate2modtype(uint8_t rate)
+{
+	rate &= IEEE80211_RATE_VAL;
+
+	if (rate == 44)
+		return IEEE80211_MODTYPE_PBCC;
+	else if (rate == 22 || rate < 12)
+		return IEEE80211_MODTYPE_DS;
+	else
+		return IEEE80211_MODTYPE_OFDM;
+}
diff --git a/sys/netproto/802_11/wlan/ieee80211_output.c b/sys/netproto/802_11/wlan/ieee80211_output.c
index 3c7c823904..d6c95a426f 100644
--- a/sys/netproto/802_11/wlan/ieee80211_output.c
+++ b/sys/netproto/802_11/wlan/ieee80211_output.c
@@ -30,7 +30,7 @@
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
  * $FreeBSD: src/sys/net80211/ieee80211_output.c,v 1.26.2.8 2006/09/02 15:06:04 sam Exp $
- * $DragonFly: src/sys/netproto/802_11/wlan/ieee80211_output.c,v 1.19 2007/03/30 11:39:34 sephe Exp $
+ * $DragonFly: src/sys/netproto/802_11/wlan/ieee80211_output.c,v 1.20 2007/04/01 13:59:41 sephe Exp $
  */
 
 #include "opt_inet.h"
@@ -1802,27 +1802,15 @@ ieee80211_pwrsave(struct ieee80211com *ic, struct ieee80211_node *ni,
 		ic->ic_set_tim(ni, 1);
 }
 
-#define IEEE80211_MODTYPE_CCK	0
-#define IEEE80211_MODTYPE_OFDM	1
-#define IEEE80211_MODTYPE_PBCC	2
-
-static int
-ieee80211_rate2modtype(uint8_t rate)
-{
-	if (rate == 44)
-		return IEEE80211_MODTYPE_PBCC;
-	else if (rate == 22 || rate < 12)
-		return IEEE80211_MODTYPE_CCK;
-	else
-		return IEEE80211_MODTYPE_OFDM;
-}
-
 uint8_t
 ieee80211_ack_rate(struct ieee80211_node *ni, uint8_t rate)
 {
 	const struct ieee80211_rateset *rs = &ni->ni_rates;
 	uint8_t ack_rate = 0;
-	int modtype, i;
+	enum ieee80211_modtype modtype;
+	int i;
+
+	rate &= IEEE80211_RATE_VAL;
 
 	modtype = ieee80211_rate2modtype(rate);
 
@@ -1919,8 +1907,11 @@ ieee80211_txtime(struct ieee80211_node *ni, u_int len, uint8_t rs_rate,
 		 uint32_t flags)
 {
 	struct ieee80211com *ic = ni->ni_ic;
+	enum ieee80211_modtype modtype;
 	uint16_t txtime;
-	int rate, modtype;
+	int rate;
+
+	rs_rate &= IEEE80211_RATE_VAL;
 
 	rate = rs_rate * 500;	/* ieee80211 rate -> kbps */
 
diff --git a/sys/netproto/802_11/wlan/ieee80211_ratectl.c b/sys/netproto/802_11/wlan/ieee80211_ratectl.c
index 550e576687..20cc1dbc20 100644
--- a/sys/netproto/802_11/wlan/ieee80211_ratectl.c
+++ b/sys/netproto/802_11/wlan/ieee80211_ratectl.c
@@ -31,7 +31,7 @@
  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  * 
- * $DragonFly: src/sys/netproto/802_11/wlan/ieee80211_ratectl.c,v 1.3 2007/03/19 13:38:43 sephe Exp $
+ * $DragonFly: src/sys/netproto/802_11/wlan/ieee80211_ratectl.c,v 1.4 2007/04/01 13:59:41 sephe Exp $
  */
 
 #include <sys/param.h>
@@ -49,7 +49,8 @@ static const struct ieee80211_ratectl *ratectls[IEEE80211_RATECTL_MAX] = {
 
 static const char *ratectl_modname[IEEE80211_RATECTL_MAX] = {
 	[IEEE80211_RATECTL_ONOE]	= "wlan_ratectl_onoe",
-	[IEEE80211_RATECTL_AMRR]	= "wlan_ratectl_amrr"
+	[IEEE80211_RATECTL_AMRR]	= "wlan_ratectl_amrr",
+	[IEEE80211_RATECTL_SAMPLE]	= "wlan_ratectl_sample"
 };
 
 void
diff --git a/sys/netproto/802_11/wlan_ratectl/Makefile b/sys/netproto/802_11/wlan_ratectl/Makefile
index 01bc9dc1ef..5637a653cf 100644
--- a/sys/netproto/802_11/wlan_ratectl/Makefile
+++ b/sys/netproto/802_11/wlan_ratectl/Makefile
@@ -1,5 +1,5 @@
-# $DragonFly: src/sys/netproto/802_11/wlan_ratectl/Makefile,v 1.1 2006/09/01 17:12:11 sephe Exp $
+# $DragonFly: src/sys/netproto/802_11/wlan_ratectl/Makefile,v 1.2 2007/04/01 13:59:41 sephe Exp $
 
-SUBDIR= onoe amrr
+SUBDIR= onoe amrr sample
 
 .include <bsd.subdir.mk>
diff --git a/sys/netproto/802_11/wlan_ratectl/sample/Makefile b/sys/netproto/802_11/wlan_ratectl/sample/Makefile
new file mode 100644
index 0000000000..7e7dc62e91
--- /dev/null
+++ b/sys/netproto/802_11/wlan_ratectl/sample/Makefile
@@ -0,0 +1,7 @@
+# $DragonFly: src/sys/netproto/802_11/wlan_ratectl/sample/Makefile,v 1.1 2007/04/01 13:59:41 sephe Exp $
+
+KMOD	= wlan_ratectl_sample
+SRCS	= ieee80211_ratectl_sample.c
+KMODDEPS= wlan
+
+.include <bsd.kmod.mk>
diff --git a/sys/netproto/802_11/wlan_ratectl/sample/ieee80211_ratectl_sample.c b/sys/netproto/802_11/wlan_ratectl/sample/ieee80211_ratectl_sample.c
new file mode 100644
index 0000000000..dde655d301
--- /dev/null
+++ b/sys/netproto/802_11/wlan_ratectl/sample/ieee80211_ratectl_sample.c
@@ -0,0 +1,884 @@
+/*
+ * Copyright (c) 2005 John Bicket
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer,
+ *    without modification.
+ * 2. Redistributions in binary form must reproduce at minimum a disclaimer
+ *    similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any
+ *    redistribution must be conditioned upon including a substantially
+ *    similar Disclaimer requirement for further binary redistribution.
+ * 3. Neither the names of the above-listed copyright holders nor the names
+ *    of any contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * Alternatively, this software may be distributed under the terms of the
+ * GNU General Public License ("GPL") version 2 as published by the Free
+ * Software Foundation.
+ *
+ * NO WARRANTY
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY
+ * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY,
+ * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
+ * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
+ * THE POSSIBILITY OF SUCH DAMAGES.
+ *
+ * $FreeBSD: src/sys/dev/ath/ath_rate/sample/sample.c,v 1.8.2.3 2006/03/14 23:22:27 sam Exp $
+ * $DragonFly: src/sys/netproto/802_11/wlan_ratectl/sample/ieee80211_ratectl_sample.c,v 1.1 2007/04/01 13:59:41 sephe Exp $
+ */
+
+/*
+ * John Bicket's SampleRate control algorithm.
+ */
+
+#include <sys/param.h>
+#include <sys/kernel.h>
+#include <sys/malloc.h>
+#include <sys/module.h>
+#include <sys/sysctl.h>
+ 
+#include <net/if.h>
+#include <net/if_media.h>
+#include <net/if_arp.h>
+
+#include <netproto/802_11/ieee80211_var.h>
+#include <netproto/802_11/wlan_ratectl/sample/ieee80211_ratectl_sample.h>
+
+#define	SAMPLE_DEBUG
+
+#ifdef SAMPLE_DEBUG
+#define	DPRINTF(ssc, lv, fmt, ...) do {		\
+	if (ssc->debug >= lv)			\
+		kprintf(fmt, __VA_ARGS__);	\
+} while (0)
+#else
+#define	DPRINTF(ssc, lv, fmt, ...)
+#endif
+
+/*
+ * This file is an implementation of the SampleRate algorithm
+ * in "Bit-rate Selection in Wireless Networks"
+ * (http://www.pdos.lcs.mit.edu/papers/jbicket-ms.ps)
+ *
+ * SampleRate chooses the bit-rate it predicts will provide the most
+ * throughput based on estimates of the expected per-packet
+ * transmission time for each bit-rate.  SampleRate periodically sends
+ * packets at bit-rates other than the current one to estimate when
+ * another bit-rate will provide better performance. SampleRate
+ * switches to another bit-rate when its estimated per-packet
+ * transmission time becomes smaller than the current bit-rate's.
+ * SampleRate reduces the number of bit-rates it must sample by
+ * eliminating those that could not perform better than the one
+ * currently being used.  SampleRate also stops probing at a bit-rate
+ * if it experiences several successive losses.
+ *
+ * The difference between the algorithm in the thesis and the one in this
+ * file is that the one in this file uses a ewma instead of a window.
+ *
+ * Also, this implementation tracks the average transmission time for
+ * a few different packet sizes independently for each link.
+ */
+
+#define STALE_FAILURE_TIMEOUT_MS	10000
+#define MIN_SWITCH_MS			1000
+
+static void	*sample_attach(struct ieee80211com *);
+static void	sample_detach(void *);
+static void	sample_data_alloc(struct ieee80211_node *);
+static void	sample_data_free(struct ieee80211_node *);
+static void	sample_data_dup(const struct ieee80211_node *,
+				struct ieee80211_node *);
+static void	sample_newstate(void *, enum ieee80211_state);
+static void	sample_tx_complete(void *, struct ieee80211_node *, int,
+				   const struct ieee80211_ratectl_res[],
+				   int, int, int, int);
+static void	sample_newassoc(void *, struct ieee80211_node *, int);
+static int	sample_findrate(void *, struct ieee80211_node *, int,
+				int[], int);
+
+static void	sample_sysctl_attach(struct sample_softc *);
+static void	sample_start(struct sample_softc *, struct ieee80211_node *);
+static void	sample_update_stats(struct sample_softc *,
+				    struct ieee80211_node *, int, int,
+				    const struct ieee80211_ratectl_res [], int,
+				    int, int);
+
+static const struct ieee80211_ratectl sample = {
+	.rc_name	= "sample",
+	.rc_ratectl	= IEEE80211_RATECTL_SAMPLE,
+	.rc_attach	= sample_attach,
+	.rc_detach	= sample_detach,
+	.rc_data_alloc	= sample_data_alloc,
+	.rc_data_free	= sample_data_free,
+	.rc_data_dup	= sample_data_dup,
+	.rc_newstate	= sample_newstate,
+	.rc_tx_complete	= sample_tx_complete,
+	.rc_newassoc	= sample_newassoc,
+	.rc_findrate	= sample_findrate
+};
+
+static u_int	sample_nrefs;
+
+/*
+ * for now, we track performance for three different packet
+ * size buckets
+ */
+static int	packet_size_bins[NUM_PACKET_SIZE_BINS] = { 250, 1600, 3000 };
+
+MALLOC_DEFINE(M_SAMPLE_RATECTL_DATA, "sample_ratectl_data",
+	      "sample rate control data");
+
+static __inline int
+size_to_bin(int size) 
+{
+	int x;
+
+	for (x = 0; x < NUM_PACKET_SIZE_BINS; x++) {
+		if (size <= packet_size_bins[x])
+			return x;
+	}
+	return NUM_PACKET_SIZE_BINS - 1;
+}
+
+static __inline int
+bin_to_size(int index)
+{
+	return packet_size_bins[index];
+}
+
+static __inline int
+rate_to_ndx(struct ieee80211_node *ni, int rate)
+{
+	int x = 0;
+
+	for (x = 0; x < ni->ni_rates.rs_nrates; x++) {
+		if (IEEE80211_RS_RATE(&ni->ni_rates, x) == rate)
+			return x;
+	}
+	return -1;
+}
+
+static __inline int
+unicast_pkt_time(struct sample_softc *ssc, struct ieee80211_node *ni,
+		 int rate, int len, int data_tries, int rts_tries,
+		 int *cw0)
+{
+	struct ieee80211com *ic = ssc->ic;
+	int sifs, difs, slot;
+	int ack_dur, data_dur, cw;
+	int tt = 0;
+	int i;
+
+	ack_dur = ieee80211_txtime(ni,
+			sizeof(struct ieee80211_frame_ack) + IEEE80211_FCS_LEN,
+			ieee80211_ack_rate(ni, rate), ic->ic_flags);
+	data_dur = ieee80211_txtime(ni, len, rate, ic->ic_flags);
+
+	if (IEEE80211_IS_CHAN_5GHZ(ni->ni_chan)) {
+		cw = IEEE80211_CW_MIN_1;
+		sifs = IEEE80211_DUR_OFDM_SIFS;
+		slot = IEEE80211_DUR_OFDM_SLOT;
+	} else {
+		/* XXX should base on characteristic rate set */
+		cw = IEEE80211_CW_MIN_0;
+		sifs = IEEE80211_DUR_SIFS;
+		slot = (ic->ic_flags & IEEE80211_F_SHSLOT)
+			? IEEE80211_DUR_SHSLOT
+			: IEEE80211_DUR_SLOT;
+	}
+	if (cw0 != NULL && *cw0 != 0)
+		cw = *cw0;
+	difs = IEEE80211_DUR_DIFS(sifs, slot);
+
+	if (rts_tries > 0 && (ic->ic_flags & IEEE80211_F_USEPROT) &&
+	    ieee80211_rate2modtype(rate) == IEEE80211_MODTYPE_OFDM) {
+		if (ic->ic_protmode == IEEE80211_PROT_RTSCTS) {
+			uint8_t rts_rate;
+			int rts_dur, cts_dur;
+
+			/* Assume RTS is sent at 2Mbits/s */
+			rts_rate = 4;
+
+			rts_dur = ieee80211_txtime(ni,
+					sizeof(struct ieee80211_frame_rts) +
+					IEEE80211_FCS_LEN,
+					rts_rate, ic->ic_flags);
+			cts_dur = ieee80211_txtime(ni,
+					sizeof(struct ieee80211_frame_cts) +
+					IEEE80211_FCS_LEN,
+					ieee80211_ack_rate(ni, rts_rate),
+					ic->ic_flags);
+
+			tt += rts_tries * (rts_dur + sifs + cts_dur);
+
+			/*
+			 * Immediate data transmission does not perform backoff
+			 * procedure.
+			 *
+			 * XXX not correct, if RTS retries (short retry count)
+			 * reaches dot11ShortRetryLimit, which should be rare.
+			 */
+			tt += sifs;
+			--rts_tries;
+		} else if (ic->ic_protmode == IEEE80211_PROT_CTSONLY) {
+			/* Assume CTS is sent at 2Mbits/s */
+			tt += ieee80211_txtime(ni,
+				sizeof(struct ieee80211_frame_cts) +
+				IEEE80211_FCS_LEN,
+				4, ic->ic_flags);
+			tt += sifs;
+			rts_tries = 0;
+		}
+	} else {
+		rts_tries = 0;
+	}
+
+	tt += data_tries * (data_dur + sifs + ack_dur);
+
+	/* Average time consumed by backoff procedure */
+	for (i = 0; i < (data_tries + rts_tries); ++i) {
+		tt += difs + (slot * cw / 2);
+		cw = MIN(IEEE80211_CW_MAX + 1, (cw + 1) * 2) - 1;
+	}
+	if (cw0 != NULL)
+		*cw0 = cw;
+	return tt;
+}
+
+/*
+ * returns the ndx with the lowest average_tx_time,
+ * or -1 if all the average_tx_times are 0.
+ */
+static __inline int
+best_rate_ndx(struct ieee80211_node *ni, int size_bin,
+	      int require_acked_before)
+{
+	int x, best_rate_ndx = 0, best_rate_tt = 0;
+	struct sample_data *sd = ni->ni_rate_data;
+
+        for (x = 0; x < ni->ni_rates.rs_nrates; x++) {
+		int tt = sd->stats[size_bin][x].average_tx_time;
+
+		if (tt <= 0 ||
+		    (require_acked_before &&
+		     !sd->stats[size_bin][x].packets_acked))
+			continue;
+
+		/* 9 megabits never works better than 12 */
+		if (IEEE80211_RS_RATE(&ni->ni_rates, x) == 18)
+			continue;
+
+		/* don't use a bit-rate that has been failing */
+		if (sd->stats[size_bin][x].successive_failures > 3)
+			continue;
+
+		if (!best_rate_tt || best_rate_tt > tt) {
+			best_rate_tt = tt;
+			best_rate_ndx = x;
+		}
+        }
+        return (best_rate_tt) ? best_rate_ndx : -1;
+}
+
+/*
+ * pick a good "random" bit-rate to sample other than the current one
+ */
+static __inline int
+pick_sample_ndx(struct ieee80211_node *ni, int size_bin) 
+{
+	int x = 0;
+	int current_ndx = 0;
+	unsigned current_tt = 0;
+	struct sample_data *sd = ni->ni_rate_data;
+
+	current_ndx = sd->current_rate[size_bin];
+	if (current_ndx < 0) {
+		/* no successes yet, send at the lowest bit-rate */
+		return 0;
+	}
+
+	current_tt = sd->stats[size_bin][current_ndx].average_tx_time;
+
+	for (x = 0; x < ni->ni_rates.rs_nrates; x++) {
+		int ndx = (sd->last_sample_ndx[size_bin] + 1 + x) %
+			  ni->ni_rates.rs_nrates;
+
+	        /* don't sample the current bit-rate */
+		if (ndx == current_ndx) 
+			continue;
+
+		/* this bit-rate is always worse than the current one */
+		if (sd->stats[size_bin][ndx].perfect_tx_time > current_tt) 
+			continue;
+
+		/* rarely sample bit-rates that fail a lot */
+		if (ticks - sd->stats[size_bin][ndx].last_tx < ((hz * STALE_FAILURE_TIMEOUT_MS) / 1000) &&
+		    sd->stats[size_bin][ndx].successive_failures > 3)
+			continue;
+
+		/*
+		 * don't sample more than 2 indexes higher
+		 * for rates higher than 11 megabits
+		 */
+		if (IEEE80211_RS_RATE(&ni->ni_rates, ndx) > 22 &&
+		    ndx > current_ndx + 2)
+			continue;
+
+		/* 9 megabits never works better than 12 */
+		if (IEEE80211_RS_RATE(&ni->ni_rates, ndx) == 18)
+			continue;
+
+		/*
+		 * if we're using 11 megabits, only sample up to 12 megabits
+		 */
+		if (IEEE80211_RS_RATE(&ni->ni_rates, current_ndx) == 22 &&
+		    ndx > current_ndx + 1) 
+			continue;
+
+		sd->last_sample_ndx[size_bin] = ndx;
+		return ndx;
+	}
+	return current_ndx;
+}
+
+static int
+sample_findrate(void *arg, struct ieee80211_node *ni, int frame_len,
+		int rateidx[], int rateidx_len)
+{
+	struct sample_softc *ssc = arg;
+	struct sample_data *sd = ni->ni_rate_data;
+	struct ieee80211com *ic = ssc->ic;
+	struct ieee80211_ratectl_state *rc_st = &ic->ic_ratectl;
+	int ndx, size_bin, best_ndx, change_rates, ack_before, cur_ndx, i;
+	unsigned average_tx_time;
+
+	for (i = 0; i < NUM_PACKET_SIZE_BINS; ++i) {
+		if (sd->current_rate[i] >= ni->ni_rates.rs_nrates) {
+			DPRINTF(ssc, 5, "%s: number of rates changed, "
+				"restart\n", __func__);
+			sample_start(ssc, ni);
+			break;
+		}
+	}
+
+	KKASSERT(frame_len > 0);
+	size_bin = size_to_bin(frame_len);
+
+	ack_before = (!(rc_st->rc_st_flags & IEEE80211_RATECTL_F_MRR) ||
+		      (ic->ic_flags & IEEE80211_F_USEPROT));
+	best_ndx = best_rate_ndx(ni, size_bin, ack_before);
+	if (best_ndx >= 0)
+		average_tx_time = sd->stats[size_bin][best_ndx].average_tx_time;
+	else
+		average_tx_time = 0;
+
+	if (sd->static_rate_ndx != -1) {
+		ndx = sd->static_rate_ndx;
+	} else {
+		if (sd->sample_tt[size_bin] <
+		    average_tx_time * (sd->packets_since_sample[size_bin] * ssc->sample_rate / 100)) {
+			/*
+			 * We want to limit the time measuring the
+			 * performance of other bit-rates to sample_rate%
+			 * of the total transmission time.
+			 */
+			ndx = pick_sample_ndx(ni, size_bin);
+			if (ndx != sd->current_rate[size_bin])
+				sd->current_sample_ndx[size_bin] = ndx;
+			else
+				sd->current_sample_ndx[size_bin] = -1;
+			sd->packets_since_sample[size_bin] = 0;
+		} else {
+			change_rates = 0;
+			if (!sd->packets_sent[size_bin] || best_ndx == -1) {
+				/* no packet has been sent successfully yet */
+				for (ndx = ni->ni_rates.rs_nrates - 1; ndx > 0; ndx--) {
+					/* 
+					 * pick the highest rate <= 36 Mbps
+					 * that hasn't failed.
+					 */
+					if (IEEE80211_RS_RATE(&ni->ni_rates, ndx) <= 72 && 
+					    sd->stats[size_bin][ndx].successive_failures == 0)
+						break;
+				}
+				change_rates = 1;
+				best_ndx = ndx;
+			} else if (sd->packets_sent[size_bin] < 20) {
+				/* let the bit-rate switch quickly during the first few packets */
+				change_rates = 1;
+			} else if (ticks - ((hz * MIN_SWITCH_MS) / 1000) > sd->ticks_since_switch[size_bin]) {
+				/* 2 seconds have gone by */
+				change_rates = 1;
+			} else if (average_tx_time * 2 < sd->stats[size_bin][sd->current_rate[size_bin]].average_tx_time) {
+				/* the current bit-rate is twice as slow as the best one */
+				change_rates = 1;
+			}
+
+			sd->packets_since_sample[size_bin]++;
+
+			if (change_rates) {
+				if (best_ndx != sd->current_rate[size_bin]) {
+					DPRINTF(ssc, 5, "%s: %6D size %d "
+						"switch rate "
+						"%d (%d/%d) -> %d (%d/%d) "
+						"after %d packets\n",
+						__func__,
+						ni->ni_macaddr, ":",
+						packet_size_bins[size_bin],
+						IEEE80211_RS_RATE(&ni->ni_rates, sd->current_rate[size_bin]),
+						sd->stats[size_bin][sd->current_rate[size_bin]].average_tx_time,
+						sd->stats[size_bin][sd->current_rate[size_bin]].perfect_tx_time,
+						IEEE80211_RS_RATE(&ni->ni_rates, best_ndx),
+						sd->stats[size_bin][best_ndx].average_tx_time,
+						sd->stats[size_bin][best_ndx].perfect_tx_time,
+						sd->packets_since_switch[size_bin]);
+				}
+				sd->packets_since_switch[size_bin] = 0;
+				sd->current_rate[size_bin] = best_ndx;
+				sd->ticks_since_switch[size_bin] = ticks;
+			}
+			ndx = sd->current_rate[size_bin];
+			sd->packets_since_switch[size_bin]++;
+			if (size_bin == 0) {
+	    			/*
+	    			 * set the visible txrate for this node
+			         * to the rate of small packets
+			         */
+				ni->ni_txrate = ndx;
+			}
+		}
+	}
+
+	KASSERT(ndx >= 0 && ndx < ni->ni_rates.rs_nrates, ("ndx is %d", ndx));
+
+	sd->packets_sent[size_bin]++;
+
+	cur_ndx = sd->current_rate[size_bin];
+	if (sd->stats[size_bin][cur_ndx].packets_acked == 0)
+		cur_ndx = 0;
+
+	rateidx[0] = ndx;
+	i = 1;
+	if (rateidx_len > 2) {
+		if ((rc_st->rc_st_flags & IEEE80211_RATECTL_F_RSDESC) == 0 ||
+		    cur_ndx < ndx)
+			rateidx[i++] = cur_ndx;
+		else if (ndx > 0)
+			rateidx[i++] = ndx - 1;
+	}
+	if (i < rateidx_len && rateidx[i] != 0)
+		rateidx[i++] = 0;
+	return i;
+}
+
+static void
+sample_update_stats(struct sample_softc *ssc, struct ieee80211_node *ni,
+		    int size, int size_bin,
+		    const struct ieee80211_ratectl_res res[], int res_len,
+		    int rts_tries, int is_fail)
+{
+	struct sample_data *sd = ni->ni_rate_data;
+	int tt, rate, i, ndx, cw = 0, data_tries;
+
+	cw = 0;
+	ndx = res[0].rc_res_rateidx;
+
+	rate = IEEE80211_RS_RATE(&ni->ni_rates, ndx);
+	tt = unicast_pkt_time(ssc, ni, rate, size,
+			      res[0].rc_res_tries, rts_tries, &cw);
+	data_tries = res[0].rc_res_tries;
+
+	for (i = 1; i < res_len; ++i) {
+		rate = IEEE80211_RS_RATE(&ni->ni_rates, res[i].rc_res_rateidx);
+		tt += unicast_pkt_time(ssc, ni, rate, size,
+				       res[i].rc_res_tries, 0, &cw);
+		data_tries += res[i].rc_res_tries;
+	}
+
+	if (sd->stats[size_bin][ndx].total_packets < (100 / (100 - ssc->smoothing_rate))) {
+		int avg_tx = sd->stats[size_bin][ndx].average_tx_time;
+		int packets = sd->stats[size_bin][ndx].total_packets;
+
+		/* Average the first few packets. */
+		sd->stats[size_bin][ndx].average_tx_time =
+			(tt + (avg_tx * packets)) / (packets + 1);
+	} else {
+		/* Use EWMA */
+		sd->stats[size_bin][ndx].average_tx_time =
+			((sd->stats[size_bin][ndx].average_tx_time * ssc->smoothing_rate) + 
+			 (tt * (100 - ssc->smoothing_rate))) / 100;
+	}
+
+	if (is_fail) {
+		int y;
+
+		sd->stats[size_bin][ndx].successive_failures++;
+		for (y = size_bin + 1; y < NUM_PACKET_SIZE_BINS; y++) {
+			/*
+			 * also say larger packets failed since we
+			 * assume if a small packet fails at a lower
+			 * bit-rate then a larger one will also.
+			 */
+			sd->stats[y][ndx].successive_failures++;
+			sd->stats[y][ndx].last_tx = ticks;
+			sd->stats[y][ndx].tries += data_tries;
+			sd->stats[y][ndx].total_packets++;
+		}
+	} else {
+		sd->stats[size_bin][ndx].packets_acked++;
+		sd->stats[size_bin][ndx].successive_failures = 0;
+	}
+	sd->stats[size_bin][ndx].last_tx = ticks;
+	sd->stats[size_bin][ndx].tries += data_tries;
+	sd->stats[size_bin][ndx].total_packets++;
+
+	if (ndx == sd->current_sample_ndx[size_bin]) {
+		DPRINTF(ssc, 10, "%s: %6D size %d sample rate %d "
+			"tries (d%d/r%d) tt %d avg_tt (%d/%d)%s\n", 
+			__func__, ni->ni_macaddr, ":",
+			size, IEEE80211_RS_RATE(&ni->ni_rates, ndx),
+			data_tries, rts_tries, tt,
+			sd->stats[size_bin][ndx].average_tx_time,
+			sd->stats[size_bin][ndx].perfect_tx_time,
+			is_fail ? " fail" : "");
+		sd->sample_tt[size_bin] = tt;
+		sd->current_sample_ndx[size_bin] = -1;
+	}
+}
+
+static void
+sample_tx_complete(void *arg, struct ieee80211_node *ni, int frame_len,
+		   const struct ieee80211_ratectl_res res[], int res_len,
+		   int data_retry, int rts_retry, int is_fail0)
+{
+	struct sample_softc *ssc = arg;
+	struct sample_data *sd = ni->ni_rate_data;
+	int i, size_bin, size;
+
+	KKASSERT(frame_len > 0);
+	size_bin = size_to_bin(frame_len);
+	size = bin_to_size(size_bin);
+
+	if (sd == NULL || !sd->started) {
+		DPRINTF(ssc, 10, "%s: %6D size %d retries (d%d/r%d) "
+			"no rates yet\n", __func__,
+			ni->ni_macaddr, ":",
+			size, data_retry, rts_retry);
+		return;
+	}
+
+	for (i = 0; i < res_len; ++i) {
+		if (res[i].rc_res_rateidx >= ni->ni_rates.rs_nrates) {
+			DPRINTF(ssc, 5, "%s: number of rates changed, "
+				"restart\n", __func__);
+			sample_start(ssc, ni);
+			return;
+		}
+	}
+
+	DPRINTF(ssc, 20, "%s: %6D size %d retries (d%d/r%d)\n",
+		__func__, ni->ni_macaddr, ":",
+		size, data_retry, rts_retry);
+	for (i = 0; i < res_len; ++i) {
+		int is_fail = is_fail0;
+
+		if (i == 0 && (data_retry + 1) > res[0].rc_res_tries &&
+		    res[0].rc_res_rateidx == sd->current_sample_ndx[size_bin])
+			is_fail = 1;
+
+		sample_update_stats(ssc, ni, size, size_bin,
+				    &res[i], res_len - i,
+				    rts_retry + 1, is_fail);
+	}
+}
+
+static void
+sample_newassoc(void *arg, struct ieee80211_node *ni, int isnew)
+{
+	struct sample_softc *ssc = arg;
+
+	DPRINTF(ssc, 5, "%s: %6D isnew %d\n", __func__,
+		ni->ni_macaddr, ":", isnew);
+
+	if (isnew)
+		sample_start(ssc, ni);
+}
+
+/*
+ * Initialize the tables for a node.
+ */
+static void
+sample_start(struct sample_softc *ssc, struct ieee80211_node *ni)
+{
+#define	RATE(_ix)	IEEE80211_RS_RATE(&ni->ni_rates, (_ix))
+	struct ieee80211com *ic = ssc->ic;
+	struct sample_data *sd = ni->ni_rate_data;
+	int x, y, srate;
+
+	if (sd == NULL) {
+		sample_data_alloc(ni);
+
+		sd = ni->ni_rate_data;
+		if (sd == NULL)
+			return;
+	}
+
+        sd->static_rate_ndx = -1;
+	if (ic->ic_fixed_rate != IEEE80211_FIXED_RATE_NONE) {
+		/*
+		 * A fixed rate is to be used; ic_fixed_rate is an
+		 * index into the supported rate set.  Convert this
+		 * to the index into the negotiated rate set for
+		 * the node.
+		 */
+		const struct ieee80211_rateset *rs =
+			&ic->ic_sup_rates[ic->ic_curmode];
+		int r = IEEE80211_RS_RATE(rs, ic->ic_fixed_rate);
+
+		/* NB: the rate set is assumed sorted */
+		srate = ni->ni_rates.rs_nrates - 1;
+		for (; srate >= 0 && RATE(srate) != r; srate--)
+			;
+		KASSERT(srate >= 0,
+			("fixed rate %d not in rate set", ic->ic_fixed_rate));
+		sd->static_rate_ndx = srate;
+	}
+
+#ifdef SAMPLE_DEBUG
+        DPRINTF(ssc, 1, "%s: %6D size 1600 rate/tt", __func__,
+		ni->ni_macaddr, ":");
+        for (x = 0; x < ni->ni_rates.rs_nrates; x++) {
+		DPRINTF(ssc, 1, " %d/%d", RATE(x),
+			unicast_pkt_time(ssc, ni, RATE(x), 1600, 1, 1, NULL));
+	}
+	DPRINTF(ssc, 1, "%s\n", "");
+#endif
+
+	/* Set the visible bit-rate to the lowest one available */
+	ni->ni_txrate = 0;
+
+	for (y = 0; y < NUM_PACKET_SIZE_BINS; y++) {
+		int size = bin_to_size(y);
+		int ndx = 0;
+
+		sd->packets_sent[y] = 0;
+		sd->current_sample_ndx[y] = -1;
+		sd->last_sample_ndx[y] = 0;
+
+		DPRINTF(ssc, 1, "%s: %6D size %d rate/tt", __func__,
+			ni->ni_macaddr, ":", size);
+		for (x = 0; x < ni->ni_rates.rs_nrates; x++) {
+			sd->stats[y][x].successive_failures = 0;
+			sd->stats[y][x].tries = 0;
+			sd->stats[y][x].total_packets = 0;
+			sd->stats[y][x].packets_acked = 0;
+			sd->stats[y][x].last_tx = 0;
+
+			sd->stats[y][x].perfect_tx_time =
+				unicast_pkt_time(ssc, ni, RATE(x), size,
+						 1, 1, NULL);
+
+			DPRINTF(ssc, 1, " %d/%d", RATE(x),
+				sd->stats[y][x].perfect_tx_time);
+
+			sd->stats[y][x].average_tx_time =
+				sd->stats[y][x].perfect_tx_time;
+		}
+		DPRINTF(ssc, 1, "%s\n", "");
+
+		/* Set the initial rate */
+		for (ndx = ni->ni_rates.rs_nrates - 1; ndx > 0; ndx--) {
+			if (RATE(ndx) <= 72)
+				break;
+		}
+		sd->current_rate[y] = ndx;
+	}
+
+	DPRINTF(ssc, 1, "%s: %6D %d rates %d%sMbps (%dus)- %d%sMbps (%dus)\n",
+		__func__, ni->ni_macaddr, ":",
+		ni->ni_rates.rs_nrates,
+		RATE(0) / 2, RATE(0) % 2 ? ".5" : "",
+		sd->stats[1][0].perfect_tx_time,
+		RATE(ni->ni_rates.rs_nrates - 1) / 2,
+		RATE(ni->ni_rates.rs_nrates - 1) % 2 ? ".5" : "",
+		sd->stats[1][ni->ni_rates.rs_nrates - 1].perfect_tx_time);
+
+        if (sd->static_rate_ndx != -1)
+		ni->ni_txrate = sd->static_rate_ndx;
+	else
+		ni->ni_txrate = sd->current_rate[0];
+#undef RATE
+
+	sd->started = 1;
+}
+
+static void
+sample_rate_cb(void *arg, struct ieee80211_node *ni)
+{
+	sample_newassoc(arg, ni, 1);
+}
+
+/*
+ * Reset the rate control state for each 802.11 state transition.
+ */
+static void
+sample_newstate(void *arg, enum ieee80211_state state)
+{
+	struct sample_softc *ssc = arg;
+
+	if (state == IEEE80211_S_RUN) {
+		struct ieee80211com *ic = ssc->ic;
+
+		if (ic->ic_opmode != IEEE80211_M_STA) {
+			/*
+			 * Sync rates for associated stations and neighbors.
+			 */
+			ieee80211_iterate_nodes(&ic->ic_sta, sample_rate_cb,
+						ssc);
+		}
+		sample_newassoc(ssc, ic->ic_bss, 1);
+	}
+}
+
+static void
+sample_sysctl_attach(struct sample_softc *ssc)
+{
+	ssc->smoothing_rate = 95;
+	ssc->sample_rate = 10;
+	ssc->debug = 0;
+
+	sysctl_ctx_init(&ssc->sysctl_ctx);
+	ssc->sysctl_oid = SYSCTL_ADD_NODE(&ssc->sysctl_ctx,
+		SYSCTL_CHILDREN(ssc->ic->ic_sysctl_oid),
+		OID_AUTO, "sample_ratectl", CTLFLAG_RD, 0, "");
+	if (ssc->sysctl_oid == NULL) {
+		kprintf("wlan_ratectl_sample: create sysctl tree failed\n");
+		return;
+	}
+
+	/* XXX bounds check [0..100] */
+	SYSCTL_ADD_INT(&ssc->sysctl_ctx, SYSCTL_CHILDREN(ssc->sysctl_oid),
+		       OID_AUTO, "smoothing_rate", CTLFLAG_RW,
+		       &ssc->smoothing_rate, 0,
+		       "rate control: "
+		       "retry threshold to credit rate raise (%%)");
+
+	/* XXX bounds check [2..100] */
+	SYSCTL_ADD_INT(&ssc->sysctl_ctx, SYSCTL_CHILDREN(ssc->sysctl_oid),
+		       OID_AUTO, "sample_rate", CTLFLAG_RW,
+		       &ssc->sample_rate, 0,
+		       "rate control: "
+		       "# good periods before raising rate");
+
+	SYSCTL_ADD_INT(&ssc->sysctl_ctx, SYSCTL_CHILDREN(ssc->sysctl_oid),
+		       OID_AUTO, "debug", CTLFLAG_RW, &ssc->debug, 0,
+		       "rate control: debug level");
+}
+
+static void *
+sample_attach(struct ieee80211com *ic)
+{
+	struct sample_softc *ssc;
+
+	sample_nrefs++;
+
+	ssc = kmalloc(sizeof(struct sample_softc), M_DEVBUF, M_WAITOK | M_ZERO);
+	ssc->ic = ic;
+	sample_sysctl_attach(ssc);
+
+	sample_newstate(ssc, ic->ic_state);
+
+	return ssc;
+}
+
+static void
+_sample_data_free(void *arg __unused, struct ieee80211_node *ni)
+{
+	sample_data_free(ni);
+}
+
+static void
+sample_detach(void *arg)
+{
+	struct sample_softc *ssc = arg;
+	struct ieee80211com *ic = ssc->ic;
+
+	sample_newstate(ssc, IEEE80211_S_INIT);
+
+	ieee80211_iterate_nodes(&ic->ic_sta, _sample_data_free, NULL);
+	ieee80211_iterate_nodes(&ic->ic_scan, _sample_data_free, NULL);
+
+	if (ssc->sysctl_oid != NULL)
+		sysctl_ctx_free(&ssc->sysctl_ctx);
+	kfree(ssc, M_DEVBUF);
+
+	sample_nrefs--;
+}
+
+static void
+sample_data_alloc(struct ieee80211_node *ni)
+{
+	KKASSERT(ni->ni_rate_data == NULL);
+	ni->ni_rate_data = kmalloc(sizeof(struct sample_data),
+				   M_SAMPLE_RATECTL_DATA, M_NOWAIT | M_ZERO);
+}
+
+static void
+sample_data_free(struct ieee80211_node *ni)
+{
+	if (ni->ni_rate_data != NULL) {
+		kfree(ni->ni_rate_data, M_SAMPLE_RATECTL_DATA);
+		ni->ni_rate_data = NULL;
+	}
+}
+
+static void
+sample_data_dup(const struct ieee80211_node *oni, struct ieee80211_node *nni)
+{
+	if (oni->ni_rate_data == NULL || nni->ni_rate_data == NULL)
+		return;
+
+	bcopy(oni->ni_rate_data, nni->ni_rate_data,
+	      sizeof(struct sample_data));
+}
+
+/*
+ * Module glue.
+ */
+static int
+sample_modevent(module_t mod, int type, void *unused)
+{
+	switch (type) {
+	case MOD_LOAD:
+		ieee80211_ratectl_register(&sample);
+		return 0;
+	case MOD_UNLOAD:
+		if (sample_nrefs) {
+			kprintf("wlan_ratectl_sample: still in use "
+				"(%u dynamic refs)\n", sample_nrefs);
+			return EBUSY;
+		}
+		ieee80211_ratectl_unregister(&sample);
+		return 0;
+	}
+	return EINVAL;
+}
+
+static moduledata_t sample_mod = {
+	"wlan_ratectl_sample",
+	sample_modevent,
+	0
+};
+DECLARE_MODULE(wlan_ratectl_sample, sample_mod, SI_SUB_DRIVERS, SI_ORDER_FIRST);
+MODULE_VERSION(wlan_ratectl_sample, 1);
+MODULE_DEPEND(wlan_ratectl_sample, wlan, 1, 1, 1);
diff --git a/sys/netproto/802_11/wlan_ratectl/sample/ieee80211_ratectl_sample.h b/sys/netproto/802_11/wlan_ratectl/sample/ieee80211_ratectl_sample.h
new file mode 100644
index 0000000000..25518b5e8a
--- /dev/null
+++ b/sys/netproto/802_11/wlan_ratectl/sample/ieee80211_ratectl_sample.h
@@ -0,0 +1,92 @@
+/*
+ * Copyright (c) 2005 John Bicket
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer,
+ *    without modification.
+ * 2. Redistributions in binary form must reproduce at minimum a disclaimer
+ *    similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any
+ *    redistribution must be conditioned upon including a substantially
+ *    similar Disclaimer requirement for further binary redistribution.
+ * 3. Neither the names of the above-listed copyright holders nor the names
+ *    of any contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * Alternatively, this software may be distributed under the terms of the
+ * GNU General Public License ("GPL") version 2 as published by the Free
+ * Software Foundation.
+ *
+ * NO WARRANTY
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY
+ * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY,
+ * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
+ * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
+ * THE POSSIBILITY OF SUCH DAMAGES.
+ *
+ * $FreeBSD: src/sys/dev/ath/ath_rate/sample/sample.h,v 1.3.2.1 2006/02/24 19:51:11 sam Exp $
+ * $DragonFly: src/sys/netproto/802_11/wlan_ratectl/sample/ieee80211_ratectl_sample.h,v 1.1 2007/04/01 13:59:41 sephe Exp $
+ */
+
+/*
+ * Defintions for the Atheros Wireless LAN controller driver.
+ */
+#ifndef _IEEE80211_RATECTL_SAMPLE_H
+#define _IEEE80211_RATECYL_SAMPLE_H
+
+struct sample_softc {
+	struct ieee80211com	*ic;
+
+	struct sysctl_ctx_list	sysctl_ctx;
+	struct sysctl_oid	*sysctl_oid;
+
+	/* ewma percentage (out of 100) */
+	int			smoothing_rate;
+
+	/* send a different bit-rate 1/X packets */
+	int			sample_rate;
+
+	/* debug level */
+	int			debug;
+};
+
+struct rate_stats {
+	unsigned average_tx_time;
+	int successive_failures;
+	int tries;
+	int total_packets;
+	int packets_acked;
+	unsigned perfect_tx_time; /* transmit time for 0 retries */
+	int last_tx;
+};
+
+#define NUM_PACKET_SIZE_BINS	3
+
+struct sample_data {
+	int started;
+	int static_rate_ndx;
+
+	struct rate_stats stats[NUM_PACKET_SIZE_BINS][IEEE80211_RATE_MAXSIZE];
+	int last_sample_ndx[NUM_PACKET_SIZE_BINS];
+
+	int current_sample_ndx[NUM_PACKET_SIZE_BINS];       
+	int packets_sent[NUM_PACKET_SIZE_BINS];
+
+	int current_rate[NUM_PACKET_SIZE_BINS];
+	int packets_since_switch[NUM_PACKET_SIZE_BINS];
+	unsigned ticks_since_switch[NUM_PACKET_SIZE_BINS];
+
+	int packets_since_sample[NUM_PACKET_SIZE_BINS];
+	unsigned sample_tt[NUM_PACKET_SIZE_BINS];
+};
+
+#endif /* !_IEEE80211_RATECTL_SAMPLE_H */
-- 
2.11.4.GIT