/*-
 * Copyright (c) 2010 Rui Paulo <rpaulo@FreeBSD.org>
 * 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.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, 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 DAMAGE.
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/sbuf.h>
#include <sys/systm.h>
#include <sys/socket.h>
#include <sys/malloc.h>

#include <net/if.h>
#include <net/if_media.h>
#include <net/ethernet.h>
#include <net/route.h>

#include <net80211/ieee80211_var.h>
#include <net80211/ieee80211_ratectl.h>

static const struct ieee80211_ratectl *ratectls[IEEE80211_RATECTL_MAX];

static const char *ratectl_modnames[IEEE80211_RATECTL_MAX] = {
	[IEEE80211_RATECTL_AMRR]	= "wlan_amrr",
	[IEEE80211_RATECTL_RSSADAPT]	= "wlan_rssadapt",
	[IEEE80211_RATECTL_ONOE]	= "wlan_onoe",
	[IEEE80211_RATECTL_SAMPLE]	= "wlan_sample",
	[IEEE80211_RATECTL_NONE]	= "wlan_none",
};

MALLOC_DEFINE(M_80211_RATECTL, "80211ratectl", "802.11 rate control");

void
ieee80211_ratectl_register(int type, const struct ieee80211_ratectl *ratectl)
{
	if (type >= IEEE80211_RATECTL_MAX)
		return;
	ratectls[type] = ratectl;
}

void
ieee80211_ratectl_unregister(int type)
{
	if (type >= IEEE80211_RATECTL_MAX)
		return;
	ratectls[type] = NULL;
}

static void
ieee80211_ratectl_sysctl_stats_node_iter(void *arg, struct ieee80211_node *ni)
{

	struct sbuf *sb = (struct sbuf *) arg;
	sbuf_printf(sb, "MAC: %6D\n", ni->ni_macaddr, ":");
	ieee80211_ratectl_node_stats(ni, sb);
	sbuf_printf(sb, "\n");
}

static int
ieee80211_ratectl_sysctl_stats(SYSCTL_HANDLER_ARGS)
{
	struct ieee80211vap *vap = arg1;
	struct ieee80211com *ic = vap->iv_ic;
	struct sbuf sb;
	int error;

	error = sysctl_wire_old_buffer(req, 0);
	if (error)
		return (error);
	sbuf_new_for_sysctl(&sb, NULL, 8, req);
	sbuf_clear_flags(&sb, SBUF_INCLUDENUL);

	IEEE80211_LOCK(ic);
	ieee80211_iterate_nodes(&ic->ic_sta,
	    ieee80211_ratectl_sysctl_stats_node_iter,
	    &sb);
	IEEE80211_UNLOCK(ic);

	error = sbuf_finish(&sb);
	sbuf_delete(&sb);
	return (error);
}

void
ieee80211_ratectl_init(struct ieee80211vap *vap)
{
	if (vap->iv_rate == ratectls[IEEE80211_RATECTL_NONE])
		ieee80211_ratectl_set(vap, IEEE80211_RATECTL_AMRR);
	vap->iv_rate->ir_init(vap);

	/* Attach generic stats sysctl */
	SYSCTL_ADD_PROC(vap->iv_sysctl, SYSCTL_CHILDREN(vap->iv_oid), OID_AUTO,
	    "rate_stats", CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, vap,
	    0, ieee80211_ratectl_sysctl_stats, "A", "ratectl node stats");
}

void
ieee80211_ratectl_set(struct ieee80211vap *vap, int type)
{
	if (type >= IEEE80211_RATECTL_MAX)
		return;
	if (ratectls[type] == NULL) {
		ieee80211_load_module(ratectl_modnames[type]);
		if (ratectls[type] == NULL) {
			IEEE80211_DPRINTF(vap, IEEE80211_MSG_RATECTL,
			    "%s: unable to load algo %u, module %s\n",
			    __func__, type, ratectl_modnames[type]);
			vap->iv_rate = ratectls[IEEE80211_RATECTL_NONE];
			return;
		}
	}
	vap->iv_rate = ratectls[type];
}