freebsd-skq/sys/net80211/ieee80211_scan.c
adrian e853cb9f9b Break out the current 802.11 software scan methods into an indirect table.
In order for drivers to provide an alternate set of scan methods,
these have to finally use an indirection table and all of the calls
in ieee80211_scan.c need to use said table.

For all existing drivers - this is basically a glorified, KBI-breaking
functional no-op.

This is also not the final form - too much functionality is currently
hiding in ieee80211_scan_sw.c that should be in ieee80211_scan.c.
That'll be the target of some follow-up commits.

Note:

* You have to recompile your kernel/drivers after this - the net80211 KBI has
  changed.
* I'm not yet planning on bumping any versioning - I have a few more things
  to shuffle around.

Tested:

* urtwn(4) - STA mode
* Intel 7260 in local repo - overriding the methods and table at
  attach time has the desired effect (ie, all the methods are called,
  but nothing is ever performed.)
2015-06-08 02:35:43 +00:00

666 lines
18 KiB
C

/*-
* 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/condvar.h>
#include <sys/socket.h>
#include <net/if.h>
#include <net/if_var.h>
#include <net/if_media.h>
#include <net/ethernet.h>
#include <net80211/ieee80211_var.h>
/* XXX until it's implemented as attach ops */
#include <net80211/ieee80211_scan_sw.h>
#include <net/bpf.h>
/*
* Roaming-related defaults. RSSI thresholds are as returned by the
* driver (.5dBm). Transmit rate thresholds are IEEE rate codes (i.e
* .5M units) or MCS.
*/
/* rssi thresholds */
#define ROAM_RSSI_11A_DEFAULT 14 /* 11a bss */
#define ROAM_RSSI_11B_DEFAULT 14 /* 11b bss */
#define ROAM_RSSI_11BONLY_DEFAULT 14 /* 11b-only bss */
/* transmit rate thresholds */
#define ROAM_RATE_11A_DEFAULT 2*12 /* 11a bss */
#define ROAM_RATE_11B_DEFAULT 2*5 /* 11b bss */
#define ROAM_RATE_11BONLY_DEFAULT 2*1 /* 11b-only bss */
#define ROAM_RATE_HALF_DEFAULT 2*6 /* half-width 11a/g bss */
#define ROAM_RATE_QUARTER_DEFAULT 2*3 /* quarter-width 11a/g bss */
#define ROAM_MCS_11N_DEFAULT (1 | IEEE80211_RATE_MCS) /* 11n bss */
void
ieee80211_scan_attach(struct ieee80211com *ic)
{
/*
* If there's no scan method pointer, attach the
* swscan set as a default.
*/
if (ic->ic_scan_methods == NULL)
ieee80211_swscan_attach(ic);
else
ic->ic_scan_methods->sc_attach(ic);
}
void
ieee80211_scan_detach(struct ieee80211com *ic)
{
/*
* Ideally we'd do the ss_ops detach call here;
* but then sc_detach() would need to be split in two.
*
* I'll do that later.
*/
ic->ic_scan_methods->sc_detach(ic);
}
static const struct ieee80211_roamparam defroam[IEEE80211_MODE_MAX] = {
[IEEE80211_MODE_11A] = { .rssi = ROAM_RSSI_11A_DEFAULT,
.rate = ROAM_RATE_11A_DEFAULT },
[IEEE80211_MODE_11G] = { .rssi = ROAM_RSSI_11B_DEFAULT,
.rate = ROAM_RATE_11B_DEFAULT },
[IEEE80211_MODE_11B] = { .rssi = ROAM_RSSI_11BONLY_DEFAULT,
.rate = ROAM_RATE_11BONLY_DEFAULT },
[IEEE80211_MODE_TURBO_A]= { .rssi = ROAM_RSSI_11A_DEFAULT,
.rate = ROAM_RATE_11A_DEFAULT },
[IEEE80211_MODE_TURBO_G]= { .rssi = ROAM_RSSI_11A_DEFAULT,
.rate = ROAM_RATE_11A_DEFAULT },
[IEEE80211_MODE_STURBO_A]={ .rssi = ROAM_RSSI_11A_DEFAULT,
.rate = ROAM_RATE_11A_DEFAULT },
[IEEE80211_MODE_HALF] = { .rssi = ROAM_RSSI_11A_DEFAULT,
.rate = ROAM_RATE_HALF_DEFAULT },
[IEEE80211_MODE_QUARTER]= { .rssi = ROAM_RSSI_11A_DEFAULT,
.rate = ROAM_RATE_QUARTER_DEFAULT },
[IEEE80211_MODE_11NA] = { .rssi = ROAM_RSSI_11A_DEFAULT,
.rate = ROAM_MCS_11N_DEFAULT },
[IEEE80211_MODE_11NG] = { .rssi = ROAM_RSSI_11B_DEFAULT,
.rate = ROAM_MCS_11N_DEFAULT },
};
void
ieee80211_scan_vattach(struct ieee80211vap *vap)
{
struct ieee80211com *ic = vap->iv_ic;
vap->iv_bgscanidle = (IEEE80211_BGSCAN_IDLE_DEFAULT*1000)/hz;
vap->iv_bgscanintvl = IEEE80211_BGSCAN_INTVAL_DEFAULT*hz;
vap->iv_scanvalid = IEEE80211_SCAN_VALID_DEFAULT*hz;
vap->iv_roaming = IEEE80211_ROAMING_AUTO;
memcpy(vap->iv_roamparms, defroam, sizeof(defroam));
ic->ic_scan_methods->sc_vattach(vap);
}
void
ieee80211_scan_vdetach(struct ieee80211vap *vap)
{
struct ieee80211com *ic = vap->iv_ic;
struct ieee80211_scan_state *ss;
IEEE80211_LOCK(ic);
ss = ic->ic_scan;
ic->ic_scan_methods->sc_vdetach(vap);
if (ss != NULL && ss->ss_vap == vap) {
if (ss->ss_ops != NULL) {
ss->ss_ops->scan_detach(ss);
ss->ss_ops = NULL;
}
ss->ss_vap = NULL;
}
IEEE80211_UNLOCK(ic);
}
/*
* Simple-minded scanner module support.
*/
static const char *scan_modnames[IEEE80211_OPMODE_MAX] = {
"wlan_scan_sta", /* IEEE80211_M_IBSS */
"wlan_scan_sta", /* IEEE80211_M_STA */
"wlan_scan_wds", /* IEEE80211_M_WDS */
"wlan_scan_sta", /* IEEE80211_M_AHDEMO */
"wlan_scan_ap", /* IEEE80211_M_HOSTAP */
"wlan_scan_monitor", /* IEEE80211_M_MONITOR */
"wlan_scan_sta", /* IEEE80211_M_MBSS */
};
static const struct ieee80211_scanner *scanners[IEEE80211_OPMODE_MAX];
const struct ieee80211_scanner *
ieee80211_scanner_get(enum ieee80211_opmode mode)
{
if (mode >= IEEE80211_OPMODE_MAX)
return NULL;
if (scanners[mode] == NULL)
ieee80211_load_module(scan_modnames[mode]);
return scanners[mode];
}
void
ieee80211_scanner_register(enum ieee80211_opmode mode,
const struct ieee80211_scanner *scan)
{
if (mode >= IEEE80211_OPMODE_MAX)
return;
scanners[mode] = scan;
}
void
ieee80211_scanner_unregister(enum ieee80211_opmode mode,
const struct ieee80211_scanner *scan)
{
if (mode >= IEEE80211_OPMODE_MAX)
return;
if (scanners[mode] == scan)
scanners[mode] = NULL;
}
void
ieee80211_scanner_unregister_all(const struct ieee80211_scanner *scan)
{
int m;
for (m = 0; m < IEEE80211_OPMODE_MAX; m++)
if (scanners[m] == scan)
scanners[m] = NULL;
}
/*
* Update common scanner state to reflect the current
* operating mode. This is called when the state machine
* is transitioned to RUN state w/o scanning--e.g. when
* operating in monitor mode. The purpose of this is to
* ensure later callbacks find ss_ops set to properly
* reflect current operating mode.
*/
void
ieee80211_scan_update_locked(struct ieee80211vap *vap,
const struct ieee80211_scanner *scan)
{
struct ieee80211com *ic = vap->iv_ic;
struct ieee80211_scan_state *ss = ic->ic_scan;
IEEE80211_LOCK_ASSERT(ic);
#ifdef IEEE80211_DEBUG
if (ss->ss_vap != vap || ss->ss_ops != scan) {
IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
"%s: current scanner is <%s:%s>, switch to <%s:%s>\n",
__func__,
ss->ss_vap != NULL ?
ss->ss_vap->iv_ifp->if_xname : "none",
ss->ss_vap != NULL ?
ieee80211_opmode_name[ss->ss_vap->iv_opmode] : "none",
vap->iv_ifp->if_xname,
ieee80211_opmode_name[vap->iv_opmode]);
}
#endif
ss->ss_vap = vap;
if (ss->ss_ops != scan) {
/*
* Switch scanners; detach old, attach new. Special
* case where a single scan module implements multiple
* policies by using different scan ops but a common
* core. We assume if the old and new attach methods
* are identical then it's ok to just change ss_ops
* and not flush the internal state of the module.
*/
if (scan == NULL || ss->ss_ops == NULL ||
ss->ss_ops->scan_attach != scan->scan_attach) {
if (ss->ss_ops != NULL)
ss->ss_ops->scan_detach(ss);
if (scan != NULL && !scan->scan_attach(ss)) {
/* XXX attach failure */
/* XXX stat+msg */
scan = NULL;
}
}
ss->ss_ops = scan;
}
}
void
ieee80211_scan_dump_channels(const struct ieee80211_scan_state *ss)
{
struct ieee80211com *ic = ss->ss_ic;
const char *sep;
int i;
sep = "";
for (i = ss->ss_next; i < ss->ss_last; i++) {
const struct ieee80211_channel *c = ss->ss_chans[i];
printf("%s%u%c", sep, ieee80211_chan2ieee(ic, c),
ieee80211_channel_type_char(c));
sep = ", ";
}
}
#ifdef IEEE80211_DEBUG
void
ieee80211_scan_dump(struct ieee80211_scan_state *ss)
{
struct ieee80211vap *vap = ss->ss_vap;
if_printf(vap->iv_ifp, "scan set ");
ieee80211_scan_dump_channels(ss);
printf(" dwell min %lums max %lums\n",
ticks_to_msecs(ss->ss_mindwell), ticks_to_msecs(ss->ss_maxdwell));
}
#endif /* IEEE80211_DEBUG */
void
ieee80211_scan_copy_ssid(struct ieee80211vap *vap, struct ieee80211_scan_state *ss,
int nssid, const struct ieee80211_scan_ssid ssids[])
{
if (nssid > IEEE80211_SCAN_MAX_SSID) {
/* XXX printf */
IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
"%s: too many ssid %d, ignoring all of them\n",
__func__, nssid);
return;
}
memcpy(ss->ss_ssid, ssids, nssid * sizeof(ssids[0]));
ss->ss_nssid = nssid;
}
/*
* Start a scan unless one is already going.
*/
int
ieee80211_start_scan(struct ieee80211vap *vap, int flags,
u_int duration, u_int mindwell, u_int maxdwell,
u_int nssid, const struct ieee80211_scan_ssid ssids[])
{
const struct ieee80211_scanner *scan;
struct ieee80211com *ic = vap->iv_ic;
scan = ieee80211_scanner_get(vap->iv_opmode);
if (scan == NULL) {
IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
"%s: no scanner support for %s mode\n",
__func__, ieee80211_opmode_name[vap->iv_opmode]);
/* XXX stat */
return 0;
}
return ic->ic_scan_methods->sc_start_scan(scan, vap, flags, duration,
mindwell, maxdwell, nssid, ssids);
}
/*
* Check the scan cache for an ap/channel to use; if that
* fails then kick off a new scan.
*/
int
ieee80211_check_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;
const struct ieee80211_scanner *scan;
int result;
scan = ieee80211_scanner_get(vap->iv_opmode);
if (scan == NULL) {
IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
"%s: no scanner support for %s mode\n",
__func__, vap->iv_opmode);
/* XXX stat */
return 0;
}
/*
* Check if there's a list of scan candidates already.
* XXX want more than the ap we're currently associated with
*/
IEEE80211_LOCK(ic);
IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
"%s: %s scan, %s%s%s%s%s\n"
, __func__
, flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive"
, flags & IEEE80211_SCAN_FLUSH ? "flush" : "append"
, flags & IEEE80211_SCAN_NOPICK ? ", nopick" : ""
, flags & IEEE80211_SCAN_NOJOIN ? ", nojoin" : ""
, flags & IEEE80211_SCAN_PICK1ST ? ", pick1st" : ""
, flags & IEEE80211_SCAN_ONCE ? ", once" : ""
);
if (ss->ss_ops != scan) {
/* XXX re-use cache contents? e.g. adhoc<->sta */
flags |= IEEE80211_SCAN_FLUSH;
}
/*
* XXX TODO: separate things out a bit better.
*/
ieee80211_scan_update_locked(vap, scan);
result = ic->ic_scan_methods->sc_check_scan(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 scan using the current settings.
*/
int
ieee80211_check_scan_current(struct ieee80211vap *vap)
{
return ieee80211_check_scan(vap,
IEEE80211_SCAN_ACTIVE,
IEEE80211_SCAN_FOREVER, 0, 0,
vap->iv_des_nssid, vap->iv_des_ssid);
}
/*
* Restart a previous scan. If the previous scan completed
* then we start again using the existing channel list.
*/
int
ieee80211_bg_scan(struct ieee80211vap *vap, int flags)
{
struct ieee80211com *ic = vap->iv_ic;
const struct ieee80211_scanner *scan;
// IEEE80211_UNLOCK_ASSERT(sc);
scan = ieee80211_scanner_get(vap->iv_opmode);
if (scan == NULL) {
IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
"%s: no scanner support for %s mode\n",
__func__, vap->iv_opmode);
/* XXX stat */
return 0;
}
/*
* XXX TODO: pull apart the bgscan logic into whatever
* belongs here and whatever belongs in the software
* scanner.
*/
return (ic->ic_scan_methods->sc_bg_scan(scan, vap, flags));
}
/*
* Cancel any scan currently going on for the specified vap.
*/
void
ieee80211_cancel_scan(struct ieee80211vap *vap)
{
struct ieee80211com *ic = vap->iv_ic;
ic->ic_scan_methods->sc_cancel_scan(vap);
}
/*
* Cancel any scan currently going on.
*/
void
ieee80211_cancel_anyscan(struct ieee80211vap *vap)
{
struct ieee80211com *ic = vap->iv_ic;
ic->ic_scan_methods->sc_cancel_anyscan(vap);
}
/*
* Public access to scan_next for drivers that manage
* scanning themselves (e.g. for firmware-based devices).
*/
void
ieee80211_scan_next(struct ieee80211vap *vap)
{
struct ieee80211com *ic = vap->iv_ic;
ic->ic_scan_methods->sc_scan_next(vap);
}
/*
* Public access to scan_next for drivers that are not able to scan single
* channels (e.g. for firmware-based devices).
*/
void
ieee80211_scan_done(struct ieee80211vap *vap)
{
struct ieee80211com *ic = vap->iv_ic;
struct ieee80211_scan_state *ss;
IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, "%s: called\n", __func__);
IEEE80211_LOCK(ic);
ss = ic->ic_scan;
ss->ss_next = ss->ss_last; /* all channels are complete */
ic->ic_scan_methods->sc_scan_done(vap);
IEEE80211_UNLOCK(ic);
}
/*
* Probe the curent 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.
*/
void
ieee80211_probe_curchan(struct ieee80211vap *vap, int force)
{
struct ieee80211com *ic = vap->iv_ic;
if ((ic->ic_curchan->ic_flags & IEEE80211_CHAN_PASSIVE) && !force) {
ic->ic_flags_ext |= IEEE80211_FEXT_PROBECHAN;
return;
}
ic->ic_scan_methods->sc_scan_probe_curchan(vap, force);
}
#ifdef IEEE80211_DEBUG
static void
dump_country(const uint8_t *ie)
{
const struct ieee80211_country_ie *cie =
(const struct ieee80211_country_ie *) ie;
int i, nbands, schan, nchan;
if (cie->len < 3) {
printf(" <bogus country ie, len %d>", cie->len);
return;
}
printf(" country [%c%c%c", cie->cc[0], cie->cc[1], cie->cc[2]);
nbands = (cie->len - 3) / sizeof(cie->band[0]);
for (i = 0; i < nbands; i++) {
schan = cie->band[i].schan;
nchan = cie->band[i].nchan;
if (nchan != 1)
printf(" %u-%u,%u", schan, schan + nchan-1,
cie->band[i].maxtxpwr);
else
printf(" %u,%u", schan, cie->band[i].maxtxpwr);
}
printf("]");
}
void
ieee80211_scan_dump_probe_beacon(uint8_t subtype, int isnew,
const uint8_t mac[IEEE80211_ADDR_LEN],
const struct ieee80211_scanparams *sp, int rssi)
{
printf("[%s] %s%s on chan %u (bss chan %u) ",
ether_sprintf(mac), isnew ? "new " : "",
ieee80211_mgt_subtype_name[subtype >> IEEE80211_FC0_SUBTYPE_SHIFT],
sp->chan, sp->bchan);
ieee80211_print_essid(sp->ssid + 2, sp->ssid[1]);
printf(" rssi %d\n", rssi);
if (isnew) {
printf("[%s] caps 0x%x bintval %u erp 0x%x",
ether_sprintf(mac), sp->capinfo, sp->bintval, sp->erp);
if (sp->country != NULL)
dump_country(sp->country);
printf("\n");
}
}
#endif /* IEEE80211_DEBUG */
/*
* Process a beacon or probe response frame.
*/
void
ieee80211_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;
return (ic->ic_scan_methods->sc_add_scan(vap, curchan, sp, wh, subtype,
rssi, noise));
}
/*
* Timeout/age scan cache entries; called from sta timeout
* timer (XXX should be self-contained).
*/
void
ieee80211_scan_timeout(struct ieee80211com *ic)
{
struct ieee80211_scan_state *ss = ic->ic_scan;
if (ss->ss_ops != NULL)
ss->ss_ops->scan_age(ss);
}
/*
* Mark a scan cache entry after a successful associate.
*/
void
ieee80211_scan_assoc_success(struct ieee80211vap *vap, const uint8_t mac[])
{
struct ieee80211_scan_state *ss = vap->iv_ic->ic_scan;
if (ss->ss_ops != NULL) {
IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_SCAN,
mac, "%s", __func__);
ss->ss_ops->scan_assoc_success(ss, mac);
}
}
/*
* Demerit a scan cache entry after failing to associate.
*/
void
ieee80211_scan_assoc_fail(struct ieee80211vap *vap,
const uint8_t mac[], int reason)
{
struct ieee80211_scan_state *ss = vap->iv_ic->ic_scan;
if (ss->ss_ops != NULL) {
IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_SCAN, mac,
"%s: reason %u", __func__, reason);
ss->ss_ops->scan_assoc_fail(ss, mac, reason);
}
}
/*
* Iterate over the contents of the scan cache.
*/
void
ieee80211_scan_iterate(struct ieee80211vap *vap,
ieee80211_scan_iter_func *f, void *arg)
{
struct ieee80211_scan_state *ss = vap->iv_ic->ic_scan;
if (ss->ss_ops != NULL)
ss->ss_ops->scan_iterate(ss, f, arg);
}
/*
* Flush the contents of the scan cache.
*/
void
ieee80211_scan_flush(struct ieee80211vap *vap)
{
struct ieee80211_scan_state *ss = vap->iv_ic->ic_scan;
if (ss->ss_ops != NULL && ss->ss_vap == vap) {
IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, "%s\n", __func__);
ss->ss_ops->scan_flush(ss);
}
}
/*
* Check the scan cache for an ap/channel to use; if that
* fails then kick off a new scan.
*/
struct ieee80211_channel *
ieee80211_scan_pickchannel(struct ieee80211com *ic, int flags)
{
struct ieee80211_scan_state *ss = ic->ic_scan;
IEEE80211_LOCK_ASSERT(ic);
if (ss == NULL || ss->ss_ops == NULL || ss->ss_vap == NULL) {
/* XXX printf? */
return NULL;
}
if (ss->ss_ops->scan_pickchan == NULL) {
IEEE80211_DPRINTF(ss->ss_vap, IEEE80211_MSG_SCAN,
"%s: scan module does not support picking a channel, "
"opmode %s\n", __func__, ss->ss_vap->iv_opmode);
return NULL;
}
return ss->ss_ops->scan_pickchan(ss, flags);
}