Author: sam
Date: Thu Jun 4 15:57:38 2009
New Revision: 193439
URL: http://svn.freebsd.org/changeset/base/193439
Log:
o station mode channel switch support
o IEEE80211_IOC_CHANSWITCH fixups:
- restrict to hostap vaps
- return EOPNOTSUPP instead of EINVAL when applied to !hostap vap
or to a vap w/o 11h enabled
- interpret count of 0 to mean cancel the current CSA
Reviewed by: rpaulo, avatar
Modified:
head/sys/net80211/ieee80211.h
head/sys/net80211/ieee80211_input.c
head/sys/net80211/ieee80211_ioctl.c
head/sys/net80211/ieee80211_output.c
head/sys/net80211/ieee80211_proto.c
head/sys/net80211/ieee80211_proto.h
head/sys/net80211/ieee80211_scan.h
head/sys/net80211/ieee80211_sta.c
head/sys/net80211/ieee80211_var.h
Modified: head/sys/net80211/ieee80211.h
==============================================================================
--- head/sys/net80211/ieee80211.h Thu Jun 4 15:10:29 2009
(r193438)
+++ head/sys/net80211/ieee80211.h Thu Jun 4 15:57:38 2009
(r193439)
@@ -686,7 +686,7 @@ enum {
IEEE80211_ELEMID_TPCREQ = 34,
IEEE80211_ELEMID_TPCREP = 35,
IEEE80211_ELEMID_SUPPCHAN = 36,
- IEEE80211_ELEMID_CHANSWITCHANN = 37,
+ IEEE80211_ELEMID_CSA = 37,
IEEE80211_ELEMID_MEASREQ = 38,
IEEE80211_ELEMID_MEASREP = 39,
IEEE80211_ELEMID_QUIET = 40,
@@ -736,6 +736,14 @@ struct ieee80211_csa_ie {
uint8_t csa_count; /* Channel Switch Count */
} __packed;
+/*
+ * Note the min acceptable CSA count is used to guard against
+ * malicious CSA injection in station mode. Defining this value
+ * as other than 0 violates the 11h spec.
+ */
+#define IEEE80211_CSA_COUNT_MIN 2
+#define IEEE80211_CSA_COUNT_MAX 255
+
/* rate set entries are in .5 Mb/s units, and potentially marked as basic */
#define IEEE80211_RATE_BASIC 0x80
#define IEEE80211_RATE_VAL 0x7f
Modified: head/sys/net80211/ieee80211_input.c
==============================================================================
--- head/sys/net80211/ieee80211_input.c Thu Jun 4 15:10:29 2009
(r193438)
+++ head/sys/net80211/ieee80211_input.c Thu Jun 4 15:57:38 2009
(r193439)
@@ -475,6 +475,7 @@ ieee80211_parse_beacon(struct ieee80211_
* [tlv] ssid
* [tlv] supported rates
* [tlv] country information
+ * [tlv] channel switch announcement (CSA)
* [tlv] parameter set (FH/DS)
* [tlv] erp information
* [tlv] extended supported rates
@@ -508,6 +509,9 @@ ieee80211_parse_beacon(struct ieee80211_
case IEEE80211_ELEMID_COUNTRY:
scan->country = frm;
break;
+ case IEEE80211_ELEMID_CSA:
+ scan->csa = frm;
+ break;
case IEEE80211_ELEMID_FHPARMS:
if (ic->ic_phytype == IEEE80211_T_FH) {
scan->fhdwell = LE_READ_2(&frm[2]);
@@ -642,6 +646,14 @@ ieee80211_parse_beacon(struct ieee80211_
IEEE80211_VERIFY_LENGTH(scan->country[1], 3 * sizeof(uint8_t),
scan->country = NULL);
}
+ if (scan->csa != NULL) {
+ /*
+ * Validate Channel Switch Announcement; this must
+ * be the correct length or we toss the frame.
+ */
+ IEEE80211_VERIFY_LENGTH(scan->csa[1], 3 * sizeof(uint8_t),
+ scan->status |= IEEE80211_BPARSE_CSA_INVALID);
+ }
/*
* Process HT ie's. This is complicated by our
* accepting both the standard ie's and the pre-draft
Modified: head/sys/net80211/ieee80211_ioctl.c
==============================================================================
--- head/sys/net80211/ieee80211_ioctl.c Thu Jun 4 15:10:29 2009
(r193438)
+++ head/sys/net80211/ieee80211_ioctl.c Thu Jun 4 15:57:38 2009
(r193439)
@@ -2304,8 +2304,10 @@ ieee80211_ioctl_chanswitch(struct ieee80
error = copyin(ireq->i_data, &csr, sizeof(csr));
if (error != 0)
return error;
- if ((vap->iv_flags & IEEE80211_F_DOTH) == 0)
- return EINVAL;
+ /* XXX adhoc mode not supported */
+ if (vap->iv_opmode != IEEE80211_M_HOSTAP ||
+ (vap->iv_flags & IEEE80211_F_DOTH) == 0)
+ return EOPNOTSUPP;
c = ieee80211_find_channel(ic,
csr.csa_chan.ic_freq, csr.csa_chan.ic_flags);
if (c == NULL)
@@ -2313,6 +2315,8 @@ ieee80211_ioctl_chanswitch(struct ieee80
IEEE80211_LOCK(ic);
if ((ic->ic_flags & IEEE80211_F_CSAPENDING) == 0)
ieee80211_csa_startswitch(ic, c, csr.csa_mode, csr.csa_count);
+ else if (csr.csa_count == 0)
+ ieee80211_csa_cancelswitch(ic);
else
error = EBUSY;
IEEE80211_UNLOCK(ic);
Modified: head/sys/net80211/ieee80211_output.c
==============================================================================
--- head/sys/net80211/ieee80211_output.c Thu Jun 4 15:10:29 2009
(r193438)
+++ head/sys/net80211/ieee80211_output.c Thu Jun 4 15:57:38 2009
(r193439)
@@ -1468,7 +1468,7 @@ ieee80211_add_csa(uint8_t *frm, struct i
struct ieee80211com *ic = vap->iv_ic;
struct ieee80211_csa_ie *csa = (struct ieee80211_csa_ie *) frm;
- csa->csa_ie = IEEE80211_ELEMID_CHANSWITCHANN;
+ csa->csa_ie = IEEE80211_ELEMID_CSA;
csa->csa_len = 3;
csa->csa_mode = 1; /* XXX force quiet on channel */
csa->csa_newchan = ieee80211_chan2ieee(ic, ic->ic_csa_newchan);
Modified: head/sys/net80211/ieee80211_proto.c
==============================================================================
--- head/sys/net80211/ieee80211_proto.c Thu Jun 4 15:10:29 2009
(r193438)
+++ head/sys/net80211/ieee80211_proto.c Thu Jun 4 15:57:38 2009
(r193439)
@@ -1374,7 +1374,7 @@ beacon_miss(void *arg, int npending)
* handlers duplicating these checks.
*/
if (vap->iv_opmode == IEEE80211_M_STA &&
- vap->iv_state == IEEE80211_S_RUN &&
+ vap->iv_state >= IEEE80211_S_RUN &&
vap->iv_bmiss != NULL)
vap->iv_bmiss(vap);
}
@@ -1451,8 +1451,8 @@ ieee80211_csa_startswitch(struct ieee802
IEEE80211_LOCK_ASSERT(ic);
ic->ic_csa_newchan = c;
+ ic->ic_csa_mode = mode;
ic->ic_csa_count = count;
- /* XXX record mode? */
ic->ic_flags |= IEEE80211_F_CSAPENDING;
TAILQ_FOREACH(vap, &ic->ic_vaps, iv_next) {
if (vap->iv_opmode == IEEE80211_M_HOSTAP ||
@@ -1465,6 +1465,19 @@ ieee80211_csa_startswitch(struct ieee802
ieee80211_notify_csa(ic, c, mode, count);
}
+static void
+csa_completeswitch(struct ieee80211com *ic)
+{
+ struct ieee80211vap *vap;
+
+ ic->ic_csa_newchan = NULL;
+ ic->ic_flags &= ~IEEE80211_F_CSAPENDING;
+
+ TAILQ_FOREACH(vap, &ic->ic_vaps, iv_next)
+ if (vap->iv_state == IEEE80211_S_CSA)
+ ieee80211_new_state_locked(vap, IEEE80211_S_RUN, 0);
+}
+
/*
* Complete an 802.11h channel switch started by ieee80211_csa_startswitch.
* We clear state and move all vap's in CSA state to RUN state
@@ -1473,19 +1486,25 @@ ieee80211_csa_startswitch(struct ieee802
void
ieee80211_csa_completeswitch(struct ieee80211com *ic)
{
- struct ieee80211vap *vap;
-
IEEE80211_LOCK_ASSERT(ic);
KASSERT(ic->ic_flags & IEEE80211_F_CSAPENDING, ("csa not pending"));
ieee80211_setcurchan(ic, ic->ic_csa_newchan);
- ic->ic_csa_newchan = NULL;
- ic->ic_flags &= ~IEEE80211_F_CSAPENDING;
+ csa_completeswitch(ic);
+}
- TAILQ_FOREACH(vap, &ic->ic_vaps, iv_next)
- if (vap->iv_state == IEEE80211_S_CSA)
- ieee80211_new_state_locked(vap, IEEE80211_S_RUN, 0);
+/*
+ * Cancel an 802.11h channel switch started by ieee80211_csa_startswitch.
+ * We clear state and move all vap's in CSA state to RUN state
+ * so they can again transmit.
+ */
+void
+ieee80211_csa_cancelswitch(struct ieee80211com *ic)
+{
+ IEEE80211_LOCK_ASSERT(ic);
+
+ csa_completeswitch(ic);
}
/*
Modified: head/sys/net80211/ieee80211_proto.h
==============================================================================
--- head/sys/net80211/ieee80211_proto.h Thu Jun 4 15:10:29 2009
(r193438)
+++ head/sys/net80211/ieee80211_proto.h Thu Jun 4 15:57:38 2009
(r193439)
@@ -340,6 +340,7 @@ int ieee80211_beacon_update(struct ieee8
void ieee80211_csa_startswitch(struct ieee80211com *,
struct ieee80211_channel *, int mode, int count);
void ieee80211_csa_completeswitch(struct ieee80211com *);
+void ieee80211_csa_cancelswitch(struct ieee80211com *);
void ieee80211_cac_completeswitch(struct ieee80211vap *);
/*
Modified: head/sys/net80211/ieee80211_scan.h
==============================================================================
--- head/sys/net80211/ieee80211_scan.h Thu Jun 4 15:10:29 2009
(r193438)
+++ head/sys/net80211/ieee80211_scan.h Thu Jun 4 15:57:38 2009
(r193439)
@@ -176,6 +176,7 @@ enum {
IEEE80211_BPARSE_CHAN_INVALID = 0x10, /* invalid FH/DSPARMS chan */
IEEE80211_BPARSE_OFFCHAN = 0x20, /* DSPARMS chan != curchan */
IEEE80211_BPARSE_BINTVAL_INVALID= 0x40, /* invalid beacon interval */
+ IEEE80211_BPARSE_CSA_INVALID = 0x80, /* invalid CSA ie */
};
/*
@@ -211,7 +212,8 @@ struct ieee80211_scanparams {
uint8_t *htinfo;
uint8_t *ath;
uint8_t *tdma;
- uint8_t *spare[4];
+ uint8_t *csa;
+ uint8_t *spare[3];
};
/*
Modified: head/sys/net80211/ieee80211_sta.c
==============================================================================
--- head/sys/net80211/ieee80211_sta.c Thu Jun 4 15:10:29 2009
(r193438)
+++ head/sys/net80211/ieee80211_sta.c Thu Jun 4 15:57:38 2009
(r193439)
@@ -106,15 +106,28 @@ sta_vattach(struct ieee80211vap *vap)
static void
sta_beacon_miss(struct ieee80211vap *vap)
{
- KASSERT((vap->iv_ic->ic_flags & IEEE80211_F_SCAN) == 0, ("scanning"));
- KASSERT(vap->iv_state == IEEE80211_S_RUN,
- ("wrong state %d", vap->iv_state));
-
- IEEE80211_DPRINTF(vap,
- IEEE80211_MSG_STATE | IEEE80211_MSG_DEBUG,
- "beacon miss, mode %u state %s\n",
- vap->iv_opmode, ieee80211_state_name[vap->iv_state]);
+ struct ieee80211com *ic = vap->iv_ic;
+ KASSERT((ic->ic_flags & IEEE80211_F_SCAN) == 0, ("scanning"));
+ KASSERT(vap->iv_state >= IEEE80211_S_RUN,
+ ("wrong state %s", ieee80211_state_name[vap->iv_state]));
+
+ IEEE80211_DPRINTF(vap, IEEE80211_MSG_STATE | IEEE80211_MSG_DEBUG,
+ "beacon miss, mode %s state %s\n",
+ ieee80211_opmode_name[vap->iv_opmode],
+ ieee80211_state_name[vap->iv_state]);
+
+ if (vap->iv_state == IEEE80211_S_CSA) {
+ /*
+ * A Channel Switch is pending; assume we missed the
+ * beacon that would've completed the process and just
+ * force the switch. If we made a mistake we'll not
+ * find the AP on the new channel and fall back to a
+ * normal scan.
+ */
+ ieee80211_csa_completeswitch(ic);
+ return;
+ }
if (++vap->iv_bmiss_count < vap->iv_bmiss_max) {
/*
* Send a directed probe req before falling back to a
@@ -359,6 +372,7 @@ sta_newstate(struct ieee80211vap *vap, e
}
switch (ostate) {
case IEEE80211_S_RUN:
+ case IEEE80211_S_CSA:
break;
case IEEE80211_S_AUTH: /* when join is done in fw */
case IEEE80211_S_ASSOC:
@@ -412,6 +426,10 @@ sta_newstate(struct ieee80211vap *vap, e
if (ic->ic_newassoc != NULL)
ic->ic_newassoc(vap->iv_bss, ostate != IEEE80211_S_RUN);
break;
+ case IEEE80211_S_CSA:
+ if (ostate != IEEE80211_S_RUN)
+ goto invalid;
+ break;
case IEEE80211_S_SLEEP:
ieee80211_sta_pwrsave(vap, 0);
break;
@@ -1080,6 +1098,112 @@ ieee80211_parse_wmeparams(struct ieee802
}
/*
+ * Process 11h Channel Switch Announcement (CSA) ie. If this
+ * is the first CSA then initiate the switch. Otherwise we
+ * track state and trigger completion and/or cancel of the switch.
+ * XXX should be public for IBSS use
+ */
+static void
+ieee80211_parse_csaparams(struct ieee80211vap *vap, uint8_t *frm,
+ const struct ieee80211_frame *wh)
+{
+ struct ieee80211com *ic = vap->iv_ic;
+ const struct ieee80211_csa_ie *csa =
+ (const struct ieee80211_csa_ie *) frm;
+
+ KASSERT(vap->iv_state >= IEEE80211_S_RUN,
+ ("state %s", ieee80211_state_name[vap->iv_state]));
+
+ if (csa->csa_mode > 1) {
+ IEEE80211_DISCARD_IE(vap,
+ IEEE80211_MSG_ELEMID | IEEE80211_MSG_DOTH,
+ wh, "CSA", "invalid mode %u", csa->csa_mode);
+ return;
+ }
+ IEEE80211_LOCK(ic);
+ if ((ic->ic_flags & IEEE80211_F_CSAPENDING) == 0) {
+ /*
+ * Convert the channel number to a channel reference. We
+ * try first to preserve turbo attribute of the current
+ * channel then fallback. Note this will not work if the
+ * CSA specifies a channel that requires a band switch (e.g.
+ * 11a => 11g). This is intentional as 11h is defined only
+ * for 5GHz/11a and because the switch does not involve a
+ * reassociation, protocol state (capabilities, negotated
+ * rates, etc) may/will be wrong.
+ */
+ struct ieee80211_channel *c =
+ ieee80211_find_channel_byieee(ic, csa->csa_newchan,
+ (ic->ic_bsschan->ic_flags & IEEE80211_CHAN_ALLTURBO));
+ if (c == NULL) {
+ c = ieee80211_find_channel_byieee(ic,
+ csa->csa_newchan,
+ (ic->ic_bsschan->ic_flags & IEEE80211_CHAN_ALL));
+ if (c == NULL) {
+ IEEE80211_DISCARD_IE(vap,
+ IEEE80211_MSG_ELEMID | IEEE80211_MSG_DOTH,
+ wh, "CSA", "invalid channel %u",
+ csa->csa_newchan);
+ goto done;
+ }
+ }
+#if IEEE80211_CSA_COUNT_MIN > 0
+ if (csa->csa_count < IEEE80211_CSA_COUNT_MIN) {
+ /*
+ * Require at least IEEE80211_CSA_COUNT_MIN count to
+ * reduce the risk of being redirected by a fabricated
+ * CSA. If a valid CSA is dropped we'll still get a
+ * beacon miss when the AP leaves the channel so we'll
+ * eventually follow to the new channel.
+ *
+ * NOTE: this violates the 11h spec that states that
+ * count may be any value and if 0 then a switch
+ * should happen asap.
+ */
+ IEEE80211_DISCARD_IE(vap,
+ IEEE80211_MSG_ELEMID | IEEE80211_MSG_DOTH,
+ wh, "CSA", "count %u too small, must be >= %u",
+ csa->csa_count, IEEE80211_CSA_COUNT_MIN);
+ goto done;
+ }
+#endif
+ ieee80211_csa_startswitch(ic, c, csa->csa_mode, csa->csa_count);
+ } else {
+ /*
+ * Validate this ie against the initial CSA. We require
+ * mode and channel not change and the count must be
+ * monotonically decreasing. This may be pointless and
+ * canceling the switch as a result may be too paranoid but
+ * in the worst case if we drop out of CSA because of this
+ * and the AP does move then we'll just end up taking a
+ * beacon miss and scan to find the AP.
+ *
+ * XXX may want <= on count as we also process ProbeResp
+ * frames and those may come in w/ the same count as the
+ * previous beacon; but doing so leaves us open to a stuck
+ * count until we add a dead-man timer
+ */
+ if (!(csa->csa_count < ic->ic_csa_count &&
+ csa->csa_mode == ic->ic_csa_mode &&
+ csa->csa_newchan == ieee80211_chan2ieee(ic,
ic->ic_csa_newchan))) {
+ IEEE80211_NOTE_FRAME(vap, IEEE80211_MSG_DOTH, wh,
+ "CSA ie mismatch, initial ie <%d,%d,%d>, "
+ "this ie <%d,%d,%d>", ic->ic_csa_mode,
+ ic->ic_csa_newchan, ic->ic_csa_count,
+ csa->csa_mode, csa->csa_newchan, csa->csa_count);
+ ieee80211_csa_cancelswitch(ic);
+ } else {
+ if (csa->csa_count <= 1)
+ ieee80211_csa_completeswitch(ic);
+ else
+ ic->ic_csa_count = csa->csa_count;
+ }
+ }
+done:
+ IEEE80211_UNLOCK(ic);
+}
+
+/*
* Return non-zero if a background scan may be continued:
* o bg scan is active
* o no channel switch is pending
@@ -1245,6 +1369,20 @@ sta_recv_mgmt(struct ieee80211_node *ni,
ni->ni_dtim_count = tim->tim_count;
ni->ni_dtim_period = tim->tim_period;
}
+ if (scan.csa != NULL &&
+ (vap->iv_flags & IEEE80211_F_DOTH))
+ ieee80211_parse_csaparams(vap, scan.csa, wh);
+ else if (ic->ic_flags & IEEE80211_F_CSAPENDING) {
+ /*
+ * No CSA ie or 11h disabled, but a channel
+ * switch is pending; drop out so we aren't
+ * stuck in CSA state. If the AP really is
+ * moving we'll get a beacon miss and scan.
+ */
+ IEEE80211_LOCK(ic);
+ ieee80211_csa_cancelswitch(ic);
+ IEEE80211_UNLOCK(ic);
+ }
/*
* If scanning, pass the info to the scan module.
* Otherwise, check if it's the right time to do
Modified: head/sys/net80211/ieee80211_var.h
==============================================================================
--- head/sys/net80211/ieee80211_var.h Thu Jun 4 15:10:29 2009
(r193438)
+++ head/sys/net80211/ieee80211_var.h Thu Jun 4 15:57:38 2009
(r193439)
@@ -181,7 +181,8 @@ struct ieee80211com {
/* 802.11h/DFS state */
struct ieee80211_channel *ic_csa_newchan;/* channel for doing CSA */
- int ic_csa_count; /* count for doing CSA */
+ short ic_csa_mode; /* mode for doing CSA */
+ short ic_csa_count; /* count for doing CSA */
struct ieee80211_dfs_state ic_dfs; /* DFS state */
struct ieee80211_scan_state *ic_scan; /* scan state */
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