441 lines
12 KiB
C
441 lines
12 KiB
C
/*-
|
|
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
|
|
*
|
|
* Copyright (c) 2007-2008 Sam Leffler, Errno Consulting
|
|
* 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>
|
|
#ifdef __FreeBSD__
|
|
__FBSDID("$FreeBSD$");
|
|
#endif
|
|
|
|
/*
|
|
* IEEE 802.11 DFS/Radar support.
|
|
*/
|
|
#include "opt_inet.h"
|
|
#include "opt_wlan.h"
|
|
|
|
#include <sys/param.h>
|
|
#include <sys/systm.h>
|
|
#include <sys/mbuf.h>
|
|
#include <sys/malloc.h>
|
|
#include <sys/kernel.h>
|
|
|
|
#include <sys/socket.h>
|
|
#include <sys/sockio.h>
|
|
#include <sys/endian.h>
|
|
#include <sys/errno.h>
|
|
#include <sys/proc.h>
|
|
#include <sys/sysctl.h>
|
|
|
|
#include <net/if.h>
|
|
#include <net/if_var.h>
|
|
#include <net/if_media.h>
|
|
#include <net/ethernet.h>
|
|
|
|
#include <net80211/ieee80211_var.h>
|
|
|
|
static MALLOC_DEFINE(M_80211_DFS, "80211dfs", "802.11 DFS state");
|
|
|
|
static int ieee80211_nol_timeout = 30*60; /* 30 minutes */
|
|
SYSCTL_INT(_net_wlan, OID_AUTO, nol_timeout, CTLFLAG_RW,
|
|
&ieee80211_nol_timeout, 0, "NOL timeout (secs)");
|
|
#define NOL_TIMEOUT msecs_to_ticks(ieee80211_nol_timeout*1000)
|
|
|
|
static int ieee80211_cac_timeout = 60; /* 60 seconds */
|
|
SYSCTL_INT(_net_wlan, OID_AUTO, cac_timeout, CTLFLAG_RW,
|
|
&ieee80211_cac_timeout, 0, "CAC timeout (secs)");
|
|
#define CAC_TIMEOUT msecs_to_ticks(ieee80211_cac_timeout*1000)
|
|
|
|
/*
|
|
DFS* In order to facilitate debugging, a couple of operating
|
|
* modes aside from the default are needed.
|
|
*
|
|
* 0 - default CAC/NOL behaviour - ie, start CAC, place
|
|
* channel on NOL list.
|
|
* 1 - send CAC, but don't change channel or add the channel
|
|
* to the NOL list.
|
|
* 2 - just match on radar, don't send CAC or place channel in
|
|
* the NOL list.
|
|
*/
|
|
static int ieee80211_dfs_debug = DFS_DBG_NONE;
|
|
|
|
/*
|
|
* This option must not be included in the default kernel
|
|
* as it allows users to plainly disable CAC/NOL handling.
|
|
*/
|
|
#ifdef IEEE80211_DFS_DEBUG
|
|
SYSCTL_INT(_net_wlan, OID_AUTO, dfs_debug, CTLFLAG_RW,
|
|
&ieee80211_dfs_debug, 0, "DFS debug behaviour");
|
|
#endif
|
|
|
|
static int
|
|
null_set_quiet(struct ieee80211_node *ni, u_int8_t *quiet_elm)
|
|
{
|
|
return ENOSYS;
|
|
}
|
|
|
|
void
|
|
ieee80211_dfs_attach(struct ieee80211com *ic)
|
|
{
|
|
struct ieee80211_dfs_state *dfs = &ic->ic_dfs;
|
|
|
|
callout_init_mtx(&dfs->nol_timer, IEEE80211_LOCK_OBJ(ic), 0);
|
|
callout_init_mtx(&dfs->cac_timer, IEEE80211_LOCK_OBJ(ic), 0);
|
|
|
|
ic->ic_set_quiet = null_set_quiet;
|
|
}
|
|
|
|
void
|
|
ieee80211_dfs_detach(struct ieee80211com *ic)
|
|
{
|
|
/* NB: we assume no locking is needed */
|
|
ieee80211_dfs_reset(ic);
|
|
}
|
|
|
|
void
|
|
ieee80211_dfs_reset(struct ieee80211com *ic)
|
|
{
|
|
struct ieee80211_dfs_state *dfs = &ic->ic_dfs;
|
|
int i;
|
|
|
|
/* NB: we assume no locking is needed */
|
|
/* NB: cac_timer should be cleared by the state machine */
|
|
callout_drain(&dfs->nol_timer);
|
|
for (i = 0; i < ic->ic_nchans; i++)
|
|
ic->ic_channels[i].ic_state = 0;
|
|
dfs->lastchan = NULL;
|
|
}
|
|
|
|
static void
|
|
cac_timeout(void *arg)
|
|
{
|
|
struct ieee80211vap *vap = arg;
|
|
struct ieee80211com *ic = vap->iv_ic;
|
|
struct ieee80211_dfs_state *dfs = &ic->ic_dfs;
|
|
int i;
|
|
|
|
IEEE80211_LOCK_ASSERT(ic);
|
|
|
|
if (vap->iv_state != IEEE80211_S_CAC) /* NB: just in case */
|
|
return;
|
|
/*
|
|
* When radar is detected during a CAC we are woken
|
|
* up prematurely to switch to a new channel.
|
|
* Check the channel to decide how to act.
|
|
*/
|
|
if (IEEE80211_IS_CHAN_RADAR(ic->ic_curchan)) {
|
|
ieee80211_notify_cac(ic, ic->ic_curchan,
|
|
IEEE80211_NOTIFY_CAC_RADAR);
|
|
|
|
if_printf(vap->iv_ifp,
|
|
"CAC timer on channel %u (%u MHz) stopped due to radar\n",
|
|
ic->ic_curchan->ic_ieee, ic->ic_curchan->ic_freq);
|
|
|
|
/* XXX clobbers any existing desired channel */
|
|
/* NB: dfs->newchan may be NULL, that's ok */
|
|
vap->iv_des_chan = dfs->newchan;
|
|
ieee80211_new_state_locked(vap, IEEE80211_S_SCAN, 0);
|
|
} else {
|
|
if_printf(vap->iv_ifp,
|
|
"CAC timer on channel %u (%u MHz) expired; "
|
|
"no radar detected\n",
|
|
ic->ic_curchan->ic_ieee, ic->ic_curchan->ic_freq);
|
|
/*
|
|
* Mark all channels with the current frequency
|
|
* as having completed CAC; this keeps us from
|
|
* doing it again until we change channels.
|
|
*/
|
|
for (i = 0; i < ic->ic_nchans; i++) {
|
|
struct ieee80211_channel *c = &ic->ic_channels[i];
|
|
if (c->ic_freq == ic->ic_curchan->ic_freq)
|
|
c->ic_state |= IEEE80211_CHANSTATE_CACDONE;
|
|
}
|
|
ieee80211_notify_cac(ic, ic->ic_curchan,
|
|
IEEE80211_NOTIFY_CAC_EXPIRE);
|
|
ieee80211_cac_completeswitch(vap);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Initiate the CAC timer. The driver is responsible
|
|
* for setting up the hardware to scan for radar on the
|
|
* channnel, we just handle timing things out.
|
|
*/
|
|
void
|
|
ieee80211_dfs_cac_start(struct ieee80211vap *vap)
|
|
{
|
|
struct ieee80211com *ic = vap->iv_ic;
|
|
struct ieee80211_dfs_state *dfs = &ic->ic_dfs;
|
|
|
|
IEEE80211_LOCK_ASSERT(ic);
|
|
|
|
callout_reset(&dfs->cac_timer, CAC_TIMEOUT, cac_timeout, vap);
|
|
if_printf(vap->iv_ifp, "start %d second CAC timer on channel %u (%u MHz)\n",
|
|
ticks_to_secs(CAC_TIMEOUT),
|
|
ic->ic_curchan->ic_ieee, ic->ic_curchan->ic_freq);
|
|
ieee80211_notify_cac(ic, ic->ic_curchan, IEEE80211_NOTIFY_CAC_START);
|
|
}
|
|
|
|
/*
|
|
* Clear the CAC timer.
|
|
*/
|
|
void
|
|
ieee80211_dfs_cac_stop(struct ieee80211vap *vap)
|
|
{
|
|
struct ieee80211com *ic = vap->iv_ic;
|
|
struct ieee80211_dfs_state *dfs = &ic->ic_dfs;
|
|
|
|
IEEE80211_LOCK_ASSERT(ic);
|
|
|
|
/* NB: racey but not important */
|
|
if (callout_pending(&dfs->cac_timer)) {
|
|
if_printf(vap->iv_ifp, "stop CAC timer on channel %u (%u MHz)\n",
|
|
ic->ic_curchan->ic_ieee, ic->ic_curchan->ic_freq);
|
|
ieee80211_notify_cac(ic, ic->ic_curchan,
|
|
IEEE80211_NOTIFY_CAC_STOP);
|
|
}
|
|
callout_stop(&dfs->cac_timer);
|
|
}
|
|
|
|
void
|
|
ieee80211_dfs_cac_clear(struct ieee80211com *ic,
|
|
const struct ieee80211_channel *chan)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < ic->ic_nchans; i++) {
|
|
struct ieee80211_channel *c = &ic->ic_channels[i];
|
|
if (c->ic_freq == chan->ic_freq)
|
|
c->ic_state &= ~IEEE80211_CHANSTATE_CACDONE;
|
|
}
|
|
}
|
|
|
|
static void
|
|
dfs_timeout(void *arg)
|
|
{
|
|
struct ieee80211com *ic = arg;
|
|
struct ieee80211_dfs_state *dfs = &ic->ic_dfs;
|
|
struct ieee80211_channel *c;
|
|
int i, oldest, now;
|
|
|
|
IEEE80211_LOCK_ASSERT(ic);
|
|
|
|
now = oldest = ticks;
|
|
for (i = 0; i < ic->ic_nchans; i++) {
|
|
c = &ic->ic_channels[i];
|
|
if (IEEE80211_IS_CHAN_RADAR(c)) {
|
|
if (ieee80211_time_after_eq(now, dfs->nol_event[i]+NOL_TIMEOUT)) {
|
|
c->ic_state &= ~IEEE80211_CHANSTATE_RADAR;
|
|
if (c->ic_state & IEEE80211_CHANSTATE_NORADAR) {
|
|
/*
|
|
* NB: do this here so we get only one
|
|
* msg instead of one for every channel
|
|
* table entry.
|
|
*/
|
|
ic_printf(ic, "radar on channel %u "
|
|
"(%u MHz) cleared after timeout\n",
|
|
c->ic_ieee, c->ic_freq);
|
|
/* notify user space */
|
|
c->ic_state &=
|
|
~IEEE80211_CHANSTATE_NORADAR;
|
|
ieee80211_notify_radar(ic, c);
|
|
}
|
|
} else if (dfs->nol_event[i] < oldest)
|
|
oldest = dfs->nol_event[i];
|
|
}
|
|
}
|
|
if (oldest != now) {
|
|
/* arrange to process next channel up for a status change */
|
|
callout_schedule(&dfs->nol_timer, oldest + NOL_TIMEOUT - now);
|
|
}
|
|
}
|
|
|
|
static void
|
|
announce_radar(struct ieee80211com *ic, const struct ieee80211_channel *curchan,
|
|
const struct ieee80211_channel *newchan)
|
|
{
|
|
if (newchan == NULL)
|
|
ic_printf(ic, "radar detected on channel %u (%u MHz)\n",
|
|
curchan->ic_ieee, curchan->ic_freq);
|
|
else
|
|
ic_printf(ic, "radar detected on channel %u (%u MHz), "
|
|
"moving to channel %u (%u MHz)\n",
|
|
curchan->ic_ieee, curchan->ic_freq,
|
|
newchan->ic_ieee, newchan->ic_freq);
|
|
}
|
|
|
|
/*
|
|
* Handle a radar detection event on a channel. The channel is
|
|
* added to the NOL list and we record the time of the event.
|
|
* Entries are aged out after NOL_TIMEOUT. If radar was
|
|
* detected while doing CAC we force a state/channel change.
|
|
* Otherwise radar triggers a channel switch using the CSA
|
|
* mechanism (when the channel is the bss channel).
|
|
*/
|
|
void
|
|
ieee80211_dfs_notify_radar(struct ieee80211com *ic, struct ieee80211_channel *chan)
|
|
{
|
|
struct ieee80211_dfs_state *dfs = &ic->ic_dfs;
|
|
int i, now;
|
|
|
|
IEEE80211_LOCK_ASSERT(ic);
|
|
|
|
/*
|
|
* If doing DFS debugging (mode 2), don't bother
|
|
* running the rest of this function.
|
|
*
|
|
* Simply announce the presence of the radar and continue
|
|
* along merrily.
|
|
*/
|
|
if (ieee80211_dfs_debug == DFS_DBG_NOCSANOL) {
|
|
announce_radar(ic, chan, chan);
|
|
ieee80211_notify_radar(ic, chan);
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* Don't mark the channel and don't put it into NOL
|
|
* if we're doing DFS debugging.
|
|
*/
|
|
if (ieee80211_dfs_debug == DFS_DBG_NONE) {
|
|
/*
|
|
* Mark all entries with this frequency. Notify user
|
|
* space and arrange for notification when the radar
|
|
* indication is cleared. Then kick the NOL processing
|
|
* thread if not already running.
|
|
*/
|
|
now = ticks;
|
|
for (i = 0; i < ic->ic_nchans; i++) {
|
|
struct ieee80211_channel *c = &ic->ic_channels[i];
|
|
if (c->ic_freq == chan->ic_freq) {
|
|
c->ic_state &= ~IEEE80211_CHANSTATE_CACDONE;
|
|
c->ic_state |= IEEE80211_CHANSTATE_RADAR;
|
|
dfs->nol_event[i] = now;
|
|
}
|
|
}
|
|
ieee80211_notify_radar(ic, chan);
|
|
chan->ic_state |= IEEE80211_CHANSTATE_NORADAR;
|
|
if (!callout_pending(&dfs->nol_timer))
|
|
callout_reset(&dfs->nol_timer, NOL_TIMEOUT,
|
|
dfs_timeout, ic);
|
|
}
|
|
|
|
/*
|
|
* If radar is detected on the bss channel while
|
|
* doing CAC; force a state change by scheduling the
|
|
* callout to be dispatched asap. Otherwise, if this
|
|
* event is for the bss channel then we must quiet
|
|
* traffic and schedule a channel switch.
|
|
*
|
|
* Note this allows us to receive notification about
|
|
* channels other than the bss channel; not sure
|
|
* that can/will happen but it's simple to support.
|
|
*/
|
|
if (chan == ic->ic_bsschan) {
|
|
/* XXX need a way to defer to user app */
|
|
|
|
/*
|
|
* Don't flip over to a new channel if
|
|
* we are currently doing DFS debugging.
|
|
*/
|
|
if (ieee80211_dfs_debug == DFS_DBG_NONE)
|
|
dfs->newchan = ieee80211_dfs_pickchannel(ic);
|
|
else
|
|
dfs->newchan = chan;
|
|
|
|
announce_radar(ic, chan, dfs->newchan);
|
|
|
|
if (callout_pending(&dfs->cac_timer))
|
|
callout_schedule(&dfs->cac_timer, 0);
|
|
else if (dfs->newchan != NULL) {
|
|
/* XXX mode 1, switch count 2 */
|
|
/* XXX calculate switch count based on max
|
|
switch time and beacon interval? */
|
|
ieee80211_csa_startswitch(ic, dfs->newchan, 1, 2);
|
|
} else {
|
|
/*
|
|
* Spec says to stop all transmissions and
|
|
* wait on the current channel for an entry
|
|
* on the NOL to expire.
|
|
*/
|
|
/*XXX*/
|
|
ic_printf(ic, "%s: No free channels; waiting for entry "
|
|
"on NOL to expire\n", __func__);
|
|
}
|
|
} else {
|
|
/*
|
|
* Issue rate-limited console msgs.
|
|
*/
|
|
if (dfs->lastchan != chan) {
|
|
dfs->lastchan = chan;
|
|
dfs->cureps = 0;
|
|
announce_radar(ic, chan, NULL);
|
|
} else if (ppsratecheck(&dfs->lastevent, &dfs->cureps, 1)) {
|
|
announce_radar(ic, chan, NULL);
|
|
}
|
|
}
|
|
}
|
|
|
|
struct ieee80211_channel *
|
|
ieee80211_dfs_pickchannel(struct ieee80211com *ic)
|
|
{
|
|
struct ieee80211_channel *c;
|
|
int i, flags;
|
|
uint16_t v;
|
|
|
|
/*
|
|
* Consult the scan cache first.
|
|
*/
|
|
flags = ic->ic_curchan->ic_flags & IEEE80211_CHAN_ALL;
|
|
/*
|
|
* XXX if curchan is HT this will never find a channel
|
|
* XXX 'cuz we scan only legacy channels
|
|
*/
|
|
c = ieee80211_scan_pickchannel(ic, flags);
|
|
if (c != NULL)
|
|
return c;
|
|
/*
|
|
* No channel found in scan cache; select a compatible
|
|
* one at random (skipping channels where radar has
|
|
* been detected).
|
|
*/
|
|
get_random_bytes(&v, sizeof(v));
|
|
v %= ic->ic_nchans;
|
|
for (i = v; i < ic->ic_nchans; i++) {
|
|
c = &ic->ic_channels[i];
|
|
if (!IEEE80211_IS_CHAN_RADAR(c) &&
|
|
(c->ic_flags & flags) == flags)
|
|
return c;
|
|
}
|
|
for (i = 0; i < v; i++) {
|
|
c = &ic->ic_channels[i];
|
|
if (!IEEE80211_IS_CHAN_RADAR(c) &&
|
|
(c->ic_flags & flags) == flags)
|
|
return c;
|
|
}
|
|
ic_printf(ic, "HELP, no channel located to switch to!\n");
|
|
return NULL;
|
|
}
|