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freebsd-dev/sys/net80211/ieee80211_scan_sw.c
Bjoern A. Zeeb 3346164ce8 net80211: define mask for ss_flags rather than using hardcoded 0xfff 
scan state ss_flags in two places cut off the "internal" GOTPICK
options.  Replace the hardcoded 0xfff with a defined mask.
Note that "internal" flags is confusing as we also supplement the
the 16bit by another 16bit of "internal flags" passed around but
comaparing to GOTPICK never stored to my understanding.

No functional change.

Sponsored by:	The FreeBSD Foundation
MFC after:	3 days
Reviewed by:	adrian
Differential Revision: https://reviews.freebsd.org/D38832
2023-03-14 22:16:41 +00:00

1045 lines
31 KiB
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/*-
* Copyright (c) 2002-2008 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>
__FBSDID("$FreeBSD$");
/*
* IEEE 802.11 scanning support.
*/
#include "opt_wlan.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/condvar.h>
#include <sys/socket.h>
#include <net/if.h>
#include <net/if_var.h>
#include <net/if_media.h>
#include <net/if_private.h>
#include <net/ethernet.h>
#include <net80211/ieee80211_var.h>
#include <net80211/ieee80211_scan_sw.h>
#include <net/bpf.h>
struct scan_state {
struct ieee80211_scan_state base; /* public state */
u_int ss_iflags; /* flags used internally */
#define ISCAN_MINDWELL 0x0001 /* min dwell time reached */
#define ISCAN_DISCARD 0x0002 /* discard rx'd frames */
#define ISCAN_INTERRUPT 0x0004 /* interrupt current scan */
#define ISCAN_CANCEL 0x0008 /* cancel current scan */
#define ISCAN_PAUSE (ISCAN_INTERRUPT | ISCAN_CANCEL)
#define ISCAN_ABORT 0x0010 /* end the scan immediately */
#define ISCAN_RUNNING 0x0020 /* scan was started */
unsigned long ss_chanmindwell; /* min dwell on curchan */
unsigned long ss_scanend; /* time scan must stop */
u_int ss_duration; /* duration for next scan */
struct task ss_scan_start; /* scan start */
struct timeout_task ss_scan_curchan; /* scan execution */
};
#define SCAN_PRIVATE(ss) ((struct scan_state *) ss)
/*
* Amount of time to go off-channel during a background
* scan. This value should be large enough to catch most
* ap's but short enough that we can return on-channel
* before our listen interval expires.
*
* XXX tunable
* XXX check against configured listen interval
*/
#define IEEE80211_SCAN_OFFCHANNEL msecs_to_ticks(150)
static void scan_curchan(struct ieee80211_scan_state *, unsigned long);
static void scan_mindwell(struct ieee80211_scan_state *);
static void scan_signal(struct ieee80211_scan_state *, int);
static void scan_signal_locked(struct ieee80211_scan_state *, int);
static void scan_start(void *, int);
static void scan_curchan_task(void *, int);
static void scan_end(struct ieee80211_scan_state *, int);
static void scan_done(struct ieee80211_scan_state *, int);
MALLOC_DEFINE(M_80211_SCAN, "80211scan", "802.11 scan state");
static void
ieee80211_swscan_detach(struct ieee80211com *ic)
{
struct ieee80211_scan_state *ss = ic->ic_scan;
if (ss != NULL) {
scan_signal(ss, ISCAN_ABORT);
ieee80211_draintask(ic, &SCAN_PRIVATE(ss)->ss_scan_start);
taskqueue_drain_timeout(ic->ic_tq,
&SCAN_PRIVATE(ss)->ss_scan_curchan);
KASSERT((ic->ic_flags & IEEE80211_F_SCAN) == 0,
("scan still running"));
/*
* For now, do the ss_ops detach here rather
* than ieee80211_scan_detach().
*
* I'll figure out how to cleanly split things up
* at a later date.
*/
if (ss->ss_ops != NULL) {
ss->ss_ops->scan_detach(ss);
ss->ss_ops = NULL;
}
ic->ic_scan = NULL;
IEEE80211_FREE(SCAN_PRIVATE(ss), M_80211_SCAN);
}
}
static void
ieee80211_swscan_vattach(struct ieee80211vap *vap)
{
/* nothing to do for now */
/*
* TODO: all of the vap scan calls should be methods!
*/
}
static void
ieee80211_swscan_vdetach(struct ieee80211vap *vap)
{
struct ieee80211com *ic = vap->iv_ic;
struct ieee80211_scan_state *ss = ic->ic_scan;
IEEE80211_LOCK_ASSERT(ic);
if (ss != NULL && ss->ss_vap == vap &&
(ic->ic_flags & IEEE80211_F_SCAN))
scan_signal_locked(ss, ISCAN_ABORT);
}
static void
ieee80211_swscan_set_scan_duration(struct ieee80211vap *vap, u_int duration)
{
struct ieee80211com *ic = vap->iv_ic;
struct ieee80211_scan_state *ss = ic->ic_scan;
IEEE80211_LOCK_ASSERT(ic);
/* NB: flush frames rx'd before 1st channel change */
SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_DISCARD;
SCAN_PRIVATE(ss)->ss_duration = duration;
}
/*
* Start a scan unless one is already going.
*/
static int
ieee80211_swscan_start_scan_locked(const struct ieee80211_scanner *scan,
struct ieee80211vap *vap, int flags, u_int duration,
u_int mindwell, u_int maxdwell,
u_int nssid, const struct ieee80211_scan_ssid ssids[])
{
struct ieee80211com *ic = vap->iv_ic;
struct ieee80211_scan_state *ss = ic->ic_scan;
IEEE80211_LOCK_ASSERT(ic);
if (ic->ic_flags & IEEE80211_F_CSAPENDING) {
IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
"%s: scan inhibited by pending channel change\n", __func__);
} else if ((ic->ic_flags & IEEE80211_F_SCAN) == 0) {
IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
"%s: %s scan, duration %u mindwell %u maxdwell %u, desired mode %s, %s%s%s%s%s%s\n"
, __func__
, flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive"
, duration, mindwell, maxdwell
, ieee80211_phymode_name[vap->iv_des_mode]
, flags & IEEE80211_SCAN_FLUSH ? "flush" : "append"
, flags & IEEE80211_SCAN_NOPICK ? ", nopick" : ""
, flags & IEEE80211_SCAN_NOJOIN ? ", nojoin" : ""
, flags & IEEE80211_SCAN_NOBCAST ? ", nobcast" : ""
, flags & IEEE80211_SCAN_PICK1ST ? ", pick1st" : ""
, flags & IEEE80211_SCAN_ONCE ? ", once" : ""
);
ieee80211_scan_update_locked(vap, scan);
if (ss->ss_ops != NULL) {
if ((flags & IEEE80211_SCAN_NOSSID) == 0)
ieee80211_scan_copy_ssid(vap, ss, nssid, ssids);
ss->ss_flags = flags & IEEE80211_SCAN_PUBLIC_MASK;
if (ss->ss_flags & IEEE80211_SCAN_ACTIVE)
vap->iv_stats.is_scan_active++;
else
vap->iv_stats.is_scan_passive++;
if (flags & IEEE80211_SCAN_FLUSH)
ss->ss_ops->scan_flush(ss);
if (flags & IEEE80211_SCAN_BGSCAN)
ic->ic_flags_ext |= IEEE80211_FEXT_BGSCAN;
/* Set duration for this particular scan */
ieee80211_swscan_set_scan_duration(vap, duration);
ss->ss_next = 0;
ss->ss_mindwell = mindwell;
ss->ss_maxdwell = maxdwell;
/* NB: scan_start must be before the scan runtask */
ss->ss_ops->scan_start(ss, vap);
#ifdef IEEE80211_DEBUG
if (ieee80211_msg_scan(vap))
ieee80211_scan_dump(ss);
#endif /* IEEE80211_DEBUG */
ic->ic_flags |= IEEE80211_F_SCAN;
/* Start scan task */
ieee80211_runtask(ic, &SCAN_PRIVATE(ss)->ss_scan_start);
}
return 1;
} else {
IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
"%s: %s scan already in progress\n", __func__,
ss->ss_flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive");
}
return 0;
}
/*
* Start a scan unless one is already going.
*
* Called without the comlock held; grab the comlock as appropriate.
*/
static int
ieee80211_swscan_start_scan(const struct ieee80211_scanner *scan,
struct ieee80211vap *vap, int flags,
u_int duration, u_int mindwell, u_int maxdwell,
u_int nssid, const struct ieee80211_scan_ssid ssids[])
{
struct ieee80211com *ic = vap->iv_ic;
int result;
IEEE80211_UNLOCK_ASSERT(ic);
IEEE80211_LOCK(ic);
result = ieee80211_swscan_start_scan_locked(scan, vap, flags, duration,
mindwell, maxdwell, nssid, ssids);
IEEE80211_UNLOCK(ic);
return result;
}
/*
* Check the scan cache for an ap/channel to use; if that
* fails then kick off a new scan.
*
* Called with the comlock held.
*
* XXX TODO: split out!
*/
static int
ieee80211_swscan_check_scan(const struct ieee80211_scanner *scan,
struct ieee80211vap *vap, int flags,
u_int duration, u_int mindwell, u_int maxdwell,
u_int nssid, const struct ieee80211_scan_ssid ssids[])
{
struct ieee80211com *ic = vap->iv_ic;
struct ieee80211_scan_state *ss = ic->ic_scan;
int result;
IEEE80211_LOCK_ASSERT(ic);
if (ss->ss_ops != NULL) {
/* XXX verify ss_ops matches vap->iv_opmode */
if ((flags & IEEE80211_SCAN_NOSSID) == 0) {
/*
* Update the ssid list and mark flags so if
* we call start_scan it doesn't duplicate work.
*/
ieee80211_scan_copy_ssid(vap, ss, nssid, ssids);
flags |= IEEE80211_SCAN_NOSSID;
}
if ((ic->ic_flags & IEEE80211_F_SCAN) == 0 &&
(flags & IEEE80211_SCAN_FLUSH) == 0 &&
ieee80211_time_before(ticks, ic->ic_lastscan + vap->iv_scanvalid)) {
/*
* We're not currently scanning and the cache is
* deemed hot enough to consult. Lock out others
* by marking IEEE80211_F_SCAN while we decide if
* something is already in the scan cache we can
* use. Also discard any frames that might come
* in while temporarily marked as scanning.
*/
IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
"cache hot; ic_lastscan=%d, scanvalid=%d, ticks=%d\n",
ic->ic_lastscan,
vap->iv_scanvalid,
ticks);
SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_DISCARD;
ic->ic_flags |= IEEE80211_F_SCAN;
/* NB: need to use supplied flags in check */
ss->ss_flags = flags & IEEE80211_SCAN_PUBLIC_MASK;
result = ss->ss_ops->scan_end(ss, vap);
ic->ic_flags &= ~IEEE80211_F_SCAN;
SCAN_PRIVATE(ss)->ss_iflags &= ~ISCAN_DISCARD;
IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
"%s: scan_end returned %d\n", __func__, result);
if (result) {
ieee80211_notify_scan_done(vap);
return 1;
}
}
}
result = ieee80211_swscan_start_scan_locked(scan, vap, flags, duration,
mindwell, maxdwell, nssid, ssids);
return result;
}
/*
* Restart a previous scan. If the previous scan completed
* then we start again using the existing channel list.
*/
static int
ieee80211_swscan_bg_scan(const struct ieee80211_scanner *scan,
struct ieee80211vap *vap, int flags)
{
struct ieee80211com *ic = vap->iv_ic;
struct ieee80211_scan_state *ss = ic->ic_scan;
bool scanning;
/* XXX assert unlocked? */
// IEEE80211_UNLOCK_ASSERT(ic);
IEEE80211_LOCK(ic);
scanning = ic->ic_flags & IEEE80211_F_SCAN;
if (!scanning) {
u_int duration;
/*
* Go off-channel for a fixed interval that is large
* enough to catch most ap's but short enough that
* we can return on-channel before our listen interval
* expires.
*/
duration = IEEE80211_SCAN_OFFCHANNEL;
IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
"%s: %s scan, ticks %u duration %u\n", __func__,
ss->ss_flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive",
ticks, duration);
ieee80211_scan_update_locked(vap, scan);
if (ss->ss_ops != NULL) {
ss->ss_vap = vap;
/*
* A background scan does not select a new sta; it
* just refreshes the scan cache. Also, indicate
* the scan logic should follow the beacon schedule:
* we go off-channel and scan for a while, then
* return to the bss channel to receive a beacon,
* then go off-channel again. All during this time
* we notify the ap we're in power save mode. When
* the scan is complete we leave power save mode.
* If any beacon indicates there are frames pending
* for us then we drop out of power save mode
* (and background scan) automatically by way of the
* usual sta power save logic.
*/
ss->ss_flags |= IEEE80211_SCAN_NOPICK
| IEEE80211_SCAN_BGSCAN
| flags
;
/* if previous scan completed, restart */
if (ss->ss_next >= ss->ss_last) {
if (ss->ss_flags & IEEE80211_SCAN_ACTIVE)
vap->iv_stats.is_scan_active++;
else
vap->iv_stats.is_scan_passive++;
/*
* NB: beware of the scan cache being flushed;
* if the channel list is empty use the
* scan_start method to populate it.
*/
ss->ss_next = 0;
if (ss->ss_last != 0)
ss->ss_ops->scan_restart(ss, vap);
else {
ss->ss_ops->scan_start(ss, vap);
#ifdef IEEE80211_DEBUG
if (ieee80211_msg_scan(vap))
ieee80211_scan_dump(ss);
#endif /* IEEE80211_DEBUG */
}
}
ieee80211_swscan_set_scan_duration(vap, duration);
ss->ss_maxdwell = duration;
ic->ic_flags |= IEEE80211_F_SCAN;
ic->ic_flags_ext |= IEEE80211_FEXT_BGSCAN;
ieee80211_runtask(ic,
&SCAN_PRIVATE(ss)->ss_scan_start);
scanning = true;
} else {
/* XXX msg+stat */
}
} else {
IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
"%s: %s scan already in progress\n", __func__,
ss->ss_flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive");
}
IEEE80211_UNLOCK(ic);
return (scanning);
}
/*
* Taskqueue work to cancel a scan.
*
* Note: for offload scan devices, we may want to call into the
* driver to try and cancel scanning, however it may not be cancelable.
*/
static void
cancel_scan(struct ieee80211vap *vap, int any, const char *func)
{
struct ieee80211com *ic = vap->iv_ic;
struct ieee80211_scan_state *ss = ic->ic_scan;
struct scan_state *ss_priv = SCAN_PRIVATE(ss);
int signal;
IEEE80211_LOCK(ic);
signal = any ? ISCAN_PAUSE : ISCAN_CANCEL;
if ((ic->ic_flags & IEEE80211_F_SCAN) &&
(any || ss->ss_vap == vap) &&
(ss_priv->ss_iflags & signal) == 0) {
IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
"%s: %s %s scan\n", func,
any ? "pause" : "cancel",
ss->ss_flags & IEEE80211_SCAN_ACTIVE ?
"active" : "passive");
/* clear bg scan NOPICK */
ss->ss_flags &= ~IEEE80211_SCAN_NOPICK;
/* mark request and wake up the scan task */
scan_signal_locked(ss, signal);
} else {
IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
"%s: called; F_SCAN=%d, vap=%s, signal=%d\n",
func,
!! (ic->ic_flags & IEEE80211_F_SCAN),
(ss->ss_vap == vap ? "match" : "nomatch"),
!! (ss_priv->ss_iflags & signal));
}
IEEE80211_UNLOCK(ic);
}
/*
* Cancel any scan currently going on for the specified vap.
*/
static void
ieee80211_swscan_cancel_scan(struct ieee80211vap *vap)
{
cancel_scan(vap, 0, __func__);
}
/*
* Cancel any scan currently going on.
*/
static void
ieee80211_swscan_cancel_anyscan(struct ieee80211vap *vap)
{
/* XXX for now - just don't do this per packet. */
if (vap->iv_flags_ext & IEEE80211_FEXT_SCAN_OFFLOAD)
return;
cancel_scan(vap, 1, __func__);
}
/*
* Manually switch to the next channel in the channel list.
* Provided for drivers that manage scanning themselves
* (e.g. for firmware-based devices).
*/
static void
ieee80211_swscan_scan_next(struct ieee80211vap *vap)
{
struct ieee80211_scan_state *ss = vap->iv_ic->ic_scan;
IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, "%s: called\n", __func__);
/* wake up the scan task */
scan_signal(ss, 0);
}
/*
* Manually stop a scan that is currently running.
* Provided for drivers that are not able to scan single channels
* (e.g. for firmware-based devices).
*/
static void
ieee80211_swscan_scan_done(struct ieee80211vap *vap)
{
struct ieee80211com *ic = vap->iv_ic;
struct ieee80211_scan_state *ss = ic->ic_scan;
IEEE80211_LOCK_ASSERT(ic);
scan_signal_locked(ss, 0);
}
/*
* Probe the current channel, if allowed, while scanning.
* If the channel is not marked passive-only then send
* a probe request immediately. Otherwise mark state and
* listen for beacons on the channel; if we receive something
* then we'll transmit a probe request.
*/
static void
ieee80211_swscan_probe_curchan(struct ieee80211vap *vap, int force)
{
struct ieee80211com *ic = vap->iv_ic;
struct ieee80211_scan_state *ss = ic->ic_scan;
struct ifnet *ifp = vap->iv_ifp;
int i;
/*
* Full-offload scan devices don't require this.
*/
if (vap->iv_flags_ext & IEEE80211_FEXT_SCAN_OFFLOAD)
return;
/*
* Send directed probe requests followed by any
* broadcast probe request.
* XXX remove dependence on ic/vap->iv_bss
*/
for (i = 0; i < ss->ss_nssid; i++)
ieee80211_send_probereq(vap->iv_bss,
vap->iv_myaddr, ifp->if_broadcastaddr,
ifp->if_broadcastaddr,
ss->ss_ssid[i].ssid, ss->ss_ssid[i].len);
if ((ss->ss_flags & IEEE80211_SCAN_NOBCAST) == 0)
ieee80211_send_probereq(vap->iv_bss,
vap->iv_myaddr, ifp->if_broadcastaddr,
ifp->if_broadcastaddr,
"", 0);
}
/*
* Scan curchan. If this is an active scan and the channel
* is not marked passive then send probe request frame(s).
* Arrange for the channel change after maxdwell ticks.
*/
static void
scan_curchan(struct ieee80211_scan_state *ss, unsigned long maxdwell)
{
struct ieee80211vap *vap = ss->ss_vap;
struct ieee80211com *ic = ss->ss_ic;
IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
"%s: calling; maxdwell=%lu\n",
__func__,
maxdwell);
IEEE80211_LOCK(ic);
if (ss->ss_flags & IEEE80211_SCAN_ACTIVE)
ieee80211_probe_curchan(vap, 0);
taskqueue_enqueue_timeout(ic->ic_tq,
&SCAN_PRIVATE(ss)->ss_scan_curchan, maxdwell);
IEEE80211_UNLOCK(ic);
}
static void
scan_signal(struct ieee80211_scan_state *ss, int iflags)
{
struct ieee80211com *ic = ss->ss_ic;
IEEE80211_UNLOCK_ASSERT(ic);
IEEE80211_LOCK(ic);
scan_signal_locked(ss, iflags);
IEEE80211_UNLOCK(ic);
}
static void
scan_signal_locked(struct ieee80211_scan_state *ss, int iflags)
{
struct scan_state *ss_priv = SCAN_PRIVATE(ss);
struct timeout_task *scan_task = &ss_priv->ss_scan_curchan;
struct ieee80211com *ic = ss->ss_ic;
IEEE80211_LOCK_ASSERT(ic);
ss_priv->ss_iflags |= iflags;
if (ss_priv->ss_iflags & ISCAN_RUNNING) {
if (taskqueue_cancel_timeout(ic->ic_tq, scan_task, NULL) == 0)
taskqueue_enqueue_timeout(ic->ic_tq, scan_task, 0);
}
}
/*
* Handle mindwell requirements completed; initiate a channel
* change to the next channel asap.
*/
static void
scan_mindwell(struct ieee80211_scan_state *ss)
{
IEEE80211_DPRINTF(ss->ss_vap, IEEE80211_MSG_SCAN, "%s: called\n",
__func__);
scan_signal(ss, 0);
}
static void
scan_start(void *arg, int pending)
{
#define ISCAN_REP (ISCAN_MINDWELL | ISCAN_DISCARD)
struct ieee80211_scan_state *ss = (struct ieee80211_scan_state *) arg;
struct scan_state *ss_priv = SCAN_PRIVATE(ss);
struct ieee80211vap *vap = ss->ss_vap;
struct ieee80211com *ic = ss->ss_ic;
IEEE80211_LOCK(ic);
if (vap == NULL || (ic->ic_flags & IEEE80211_F_SCAN) == 0 ||
(ss_priv->ss_iflags & ISCAN_ABORT)) {
/* Cancelled before we started */
scan_done(ss, 0);
return;
}
if (ss->ss_next == ss->ss_last) {
IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
"%s: no channels to scan\n", __func__);
scan_done(ss, 1);
return;
}
/*
* Put the station into power save mode.
*
* This is only required if we're not a full-offload devices;
* those devices manage scan/traffic differently.
*/
if (((vap->iv_flags_ext & IEEE80211_FEXT_SCAN_OFFLOAD) == 0) &&
vap->iv_opmode == IEEE80211_M_STA &&
vap->iv_state == IEEE80211_S_RUN) {
if ((vap->iv_bss->ni_flags & IEEE80211_NODE_PWR_MGT) == 0) {
/* Enable station power save mode */
vap->iv_sta_ps(vap, 1);
/* Wait until null data frame will be ACK'ed */
mtx_sleep(vap, IEEE80211_LOCK_OBJ(ic), PCATCH,
"sta_ps", msecs_to_ticks(10));
if (ss_priv->ss_iflags & ISCAN_ABORT) {
scan_done(ss, 0);
return;
}
}
}
ss_priv->ss_scanend = ticks + ss_priv->ss_duration;
/* XXX scan state can change! Re-validate scan state! */
IEEE80211_UNLOCK(ic);
ic->ic_scan_start(ic); /* notify driver */
scan_curchan_task(ss, 0);
}
static void
scan_curchan_task(void *arg, int pending)
{
struct ieee80211_scan_state *ss = arg;
struct scan_state *ss_priv = SCAN_PRIVATE(ss);
struct ieee80211com *ic = ss->ss_ic;
struct ieee80211_channel *chan;
unsigned long maxdwell;
int scandone, scanstop;
IEEE80211_LOCK(ic);
end:
/*
* Note: only /end/ the scan if we're CANCEL rather than
* CANCEL+INTERRUPT (ie, 'PAUSE').
*
* We can stop the scan if we hit cancel, but we shouldn't
* call scan_end(ss, 1) if we're just PAUSEing the scan.
*/
scandone = (ss->ss_next >= ss->ss_last) ||
((ss_priv->ss_iflags & ISCAN_PAUSE) == ISCAN_CANCEL);
scanstop = (ss->ss_next >= ss->ss_last) ||
((ss_priv->ss_iflags & ISCAN_CANCEL) != 0);
IEEE80211_DPRINTF(ss->ss_vap, IEEE80211_MSG_SCAN,
"%s: loop start; scandone=%d, scanstop=%d, ss_iflags=0x%x, ss_next=%u, ss_last=%u\n",
__func__,
scandone,
scanstop,
(uint32_t) ss_priv->ss_iflags,
(uint32_t) ss->ss_next,
(uint32_t) ss->ss_last);
if (scanstop || (ss->ss_flags & IEEE80211_SCAN_GOTPICK) ||
(ss_priv->ss_iflags & ISCAN_ABORT) ||
ieee80211_time_after(ticks + ss->ss_mindwell, ss_priv->ss_scanend)) {
ss_priv->ss_iflags &= ~ISCAN_RUNNING;
scan_end(ss, scandone);
return;
} else
ss_priv->ss_iflags |= ISCAN_RUNNING;
chan = ss->ss_chans[ss->ss_next++];
/*
* Watch for truncation due to the scan end time.
*/
if (ieee80211_time_after(ticks + ss->ss_maxdwell, ss_priv->ss_scanend))
maxdwell = ss_priv->ss_scanend - ticks;
else
maxdwell = ss->ss_maxdwell;
IEEE80211_DPRINTF(ss->ss_vap, IEEE80211_MSG_SCAN,
"%s: chan %3d%c -> %3d%c [%s, dwell min %lums max %lums]\n",
__func__,
ieee80211_chan2ieee(ic, ic->ic_curchan),
ieee80211_channel_type_char(ic->ic_curchan),
ieee80211_chan2ieee(ic, chan),
ieee80211_channel_type_char(chan),
(ss->ss_flags & IEEE80211_SCAN_ACTIVE) &&
(chan->ic_flags & IEEE80211_CHAN_PASSIVE) == 0 ?
"active" : "passive",
ticks_to_msecs(ss->ss_mindwell), ticks_to_msecs(maxdwell));
/*
* Potentially change channel and phy mode.
*/
ic->ic_curchan = chan;
ic->ic_rt = ieee80211_get_ratetable(chan);
IEEE80211_UNLOCK(ic);
/*
* Perform the channel change and scan unlocked so the driver
* may sleep. Once set_channel returns the hardware has
* completed the channel change.
*/
ic->ic_set_channel(ic);
ieee80211_radiotap_chan_change(ic);
/*
* Scan curchan. Drivers for "intelligent hardware"
* override ic_scan_curchan to tell the device to do
* the work. Otherwise we manage the work ourselves;
* sending a probe request (as needed), and arming the
* timeout to switch channels after maxdwell ticks.
*
* scan_curchan should only pause for the time required to
* prepare/initiate the hardware for the scan (if at all).
*/
ic->ic_scan_curchan(ss, maxdwell);
IEEE80211_LOCK(ic);
/* XXX scan state can change! Re-validate scan state! */
ss_priv->ss_chanmindwell = ticks + ss->ss_mindwell;
/* clear mindwell lock and initial channel change flush */
ss_priv->ss_iflags &= ~ISCAN_REP;
if (ss_priv->ss_iflags & (ISCAN_CANCEL|ISCAN_ABORT)) {
taskqueue_cancel_timeout(ic->ic_tq, &ss_priv->ss_scan_curchan,
NULL);
goto end;
}
IEEE80211_DPRINTF(ss->ss_vap, IEEE80211_MSG_SCAN, "%s: waiting\n",
__func__);
IEEE80211_UNLOCK(ic);
}
static void
scan_end(struct ieee80211_scan_state *ss, int scandone)
{
struct scan_state *ss_priv = SCAN_PRIVATE(ss);
struct ieee80211vap *vap = ss->ss_vap;
struct ieee80211com *ic = ss->ss_ic;
IEEE80211_LOCK_ASSERT(ic);
IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, "%s: out\n", __func__);
if (ss_priv->ss_iflags & ISCAN_ABORT) {
scan_done(ss, scandone);
return;
}
IEEE80211_UNLOCK(ic);
ic->ic_scan_end(ic); /* notify driver */
IEEE80211_LOCK(ic);
/* XXX scan state can change! Re-validate scan state! */
/*
* Since a cancellation may have occurred during one of the
* driver calls (whilst unlocked), update scandone.
*/
if ((scandone == 0) && ((ss_priv->ss_iflags & ISCAN_PAUSE) == ISCAN_CANCEL)) {
/* XXX printf? */
if_printf(vap->iv_ifp,
"%s: OOPS! scan cancelled during driver call (1) (ss_iflags=0x%x)!\n",
__func__,
ss_priv->ss_iflags);
scandone = 1;
}
/*
* Record scan complete time. Note that we also do
* this when canceled so any background scan will
* not be restarted for a while.
*/
if (scandone)
ic->ic_lastscan = ticks;
/* return to the bss channel */
if (ic->ic_bsschan != IEEE80211_CHAN_ANYC &&
ic->ic_curchan != ic->ic_bsschan) {
ieee80211_setupcurchan(ic, ic->ic_bsschan);
IEEE80211_UNLOCK(ic);
ic->ic_set_channel(ic);
ieee80211_radiotap_chan_change(ic);
IEEE80211_LOCK(ic);
}
/* clear internal flags and any indication of a pick */
ss_priv->ss_iflags &= ~ISCAN_REP;
ss->ss_flags &= ~IEEE80211_SCAN_GOTPICK;
/*
* If not canceled and scan completed, do post-processing.
* If the callback function returns 0, then it wants to
* continue/restart scanning. Unfortunately we needed to
* notify the driver to end the scan above to avoid having
* rx frames alter the scan candidate list.
*/
if ((ss_priv->ss_iflags & ISCAN_CANCEL) == 0 &&
!ss->ss_ops->scan_end(ss, vap) &&
(ss->ss_flags & IEEE80211_SCAN_ONCE) == 0 &&
ieee80211_time_before(ticks + ss->ss_mindwell, ss_priv->ss_scanend)) {
IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
"%s: done, restart "
"[ticks %u, dwell min %lu scanend %lu]\n",
__func__,
ticks, ss->ss_mindwell, ss_priv->ss_scanend);
ss->ss_next = 0; /* reset to beginning */
if (ss->ss_flags & IEEE80211_SCAN_ACTIVE)
vap->iv_stats.is_scan_active++;
else
vap->iv_stats.is_scan_passive++;
ss->ss_ops->scan_restart(ss, vap); /* XXX? */
ieee80211_runtask(ic, &ss_priv->ss_scan_start);
IEEE80211_UNLOCK(ic);
return;
}
/* past here, scandone is ``true'' if not in bg mode */
if ((ss->ss_flags & IEEE80211_SCAN_BGSCAN) == 0)
scandone = 1;
IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
"%s: %s, [ticks %u, dwell min %lu scanend %lu]\n",
__func__, scandone ? "done" : "stopped",
ticks, ss->ss_mindwell, ss_priv->ss_scanend);
/*
* Since a cancellation may have occurred during one of the
* driver calls (whilst unlocked), update scandone.
*/
if (scandone == 0 && (ss_priv->ss_iflags & ISCAN_PAUSE) == ISCAN_CANCEL) {
/* XXX printf? */
if_printf(vap->iv_ifp,
"%s: OOPS! scan cancelled during driver call (2) (ss_iflags=0x%x)!\n",
__func__,
ss_priv->ss_iflags);
scandone = 1;
}
scan_done(ss, scandone);
}
static void
scan_done(struct ieee80211_scan_state *ss, int scandone)
{
struct scan_state *ss_priv = SCAN_PRIVATE(ss);
struct ieee80211com *ic = ss->ss_ic;
struct ieee80211vap *vap = ss->ss_vap;
IEEE80211_LOCK_ASSERT(ic);
/*
* Clear the SCAN bit first in case frames are
* pending on the station power save queue. If
* we defer this then the dispatch of the frames
* may generate a request to cancel scanning.
*/
ic->ic_flags &= ~IEEE80211_F_SCAN;
/*
* Drop out of power save mode when a scan has
* completed. If this scan was prematurely terminated
* because it is a background scan then don't notify
* the ap; we'll either return to scanning after we
* receive the beacon frame or we'll drop out of power
* save mode because the beacon indicates we have frames
* waiting for us.
*/
if (scandone) {
/*
* If we're not a scan offload device, come back out of
* station powersave. Offload devices handle this themselves.
*/
if ((vap->iv_flags_ext & IEEE80211_FEXT_SCAN_OFFLOAD) == 0)
vap->iv_sta_ps(vap, 0);
if (ss->ss_next >= ss->ss_last) {
IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
"%s: Dropping out of scan; ss_next=%u, ss_last=%u\n",
__func__,
(uint32_t) ss->ss_next,
(uint32_t) ss->ss_last);
ic->ic_flags_ext &= ~IEEE80211_FEXT_BGSCAN;
}
/* send 'scan done' event if not interrupted due to traffic. */
if (!(ss_priv->ss_iflags & ISCAN_INTERRUPT) ||
(ss->ss_next >= ss->ss_last))
ieee80211_notify_scan_done(vap);
}
ss_priv->ss_iflags &= ~(ISCAN_PAUSE | ISCAN_ABORT);
ss_priv->ss_scanend = 0;
ss->ss_flags &= ~(IEEE80211_SCAN_ONCE | IEEE80211_SCAN_PICK1ST);
IEEE80211_UNLOCK(ic);
#undef ISCAN_REP
}
/*
* Process a beacon or probe response frame.
*/
static void
ieee80211_swscan_add_scan(struct ieee80211vap *vap,
struct ieee80211_channel *curchan,
const struct ieee80211_scanparams *sp,
const struct ieee80211_frame *wh,
int subtype, int rssi, int noise)
{
struct ieee80211com *ic = vap->iv_ic;
struct ieee80211_scan_state *ss = ic->ic_scan;
/* XXX locking */
/*
* Frames received during startup are discarded to avoid
* using scan state setup on the initial entry to the timer
* callback. This can occur because the device may enable
* rx prior to our doing the initial channel change in the
* timer routine.
*/
if (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_DISCARD)
return;
#ifdef IEEE80211_DEBUG
if (ieee80211_msg_scan(vap) && (ic->ic_flags & IEEE80211_F_SCAN))
ieee80211_scan_dump_probe_beacon(subtype, 1, wh->i_addr2, sp, rssi);
#endif
if (ss->ss_ops != NULL &&
ss->ss_ops->scan_add(ss, curchan, sp, wh, subtype, rssi, noise)) {
/*
* If we've reached the min dwell time terminate
* the timer so we'll switch to the next channel.
*/
if ((SCAN_PRIVATE(ss)->ss_iflags & ISCAN_MINDWELL) == 0 &&
ieee80211_time_after_eq(ticks, SCAN_PRIVATE(ss)->ss_chanmindwell)) {
IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
"%s: chan %3d%c min dwell met (%u > %lu)\n",
__func__,
ieee80211_chan2ieee(ic, ic->ic_curchan),
ieee80211_channel_type_char(ic->ic_curchan),
ticks, SCAN_PRIVATE(ss)->ss_chanmindwell);
SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_MINDWELL;
/*
* NB: trigger at next clock tick or wait for the
* hardware.
*/
ic->ic_scan_mindwell(ss);
}
}
}
static struct ieee80211_scan_methods swscan_methods = {
.sc_attach = ieee80211_swscan_attach,
.sc_detach = ieee80211_swscan_detach,
.sc_vattach = ieee80211_swscan_vattach,
.sc_vdetach = ieee80211_swscan_vdetach,
.sc_set_scan_duration = ieee80211_swscan_set_scan_duration,
.sc_start_scan = ieee80211_swscan_start_scan,
.sc_check_scan = ieee80211_swscan_check_scan,
.sc_bg_scan = ieee80211_swscan_bg_scan,
.sc_cancel_scan = ieee80211_swscan_cancel_scan,
.sc_cancel_anyscan = ieee80211_swscan_cancel_anyscan,
.sc_scan_next = ieee80211_swscan_scan_next,
.sc_scan_done = ieee80211_swscan_scan_done,
.sc_scan_probe_curchan = ieee80211_swscan_probe_curchan,
.sc_add_scan = ieee80211_swscan_add_scan
};
/*
* Default scan attach method.
*/
void
ieee80211_swscan_attach(struct ieee80211com *ic)
{
struct scan_state *ss;
/*
* Setup the default methods
*/
ic->ic_scan_methods = &swscan_methods;
/* Allocate initial scan state */
ss = (struct scan_state *) IEEE80211_MALLOC(sizeof(struct scan_state),
M_80211_SCAN, IEEE80211_M_NOWAIT | IEEE80211_M_ZERO);
if (ss == NULL) {
ic->ic_scan = NULL;
return;
}
TASK_INIT(&ss->ss_scan_start, 0, scan_start, ss);
TIMEOUT_TASK_INIT(ic->ic_tq, &ss->ss_scan_curchan, 0,
scan_curchan_task, ss);
ic->ic_scan = &ss->base;
ss->base.ss_ic = ic;
ic->ic_scan_curchan = scan_curchan;
ic->ic_scan_mindwell = scan_mindwell;
}
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