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cfg80211: introduce TDLS channel switch commands
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Introduce commands to initiate and cancel TDLS channel-switching. Once
TDLS channel-switching is started, the lower level driver is responsible
for continually initiating channel-switch operations and returning to
the base (AP) channel to listen for beacons from time to time.

Upon cancellation of the channel-switch all communication between the
relevant TDLS peers will continue on the base channel.

Signed-off-by: Arik Nemtsov <arikx.nemtsov@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
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Arik Nemtsov authored and Johannes Berg committed Nov 19, 2014
1 parent c273390 commit 1057d35
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Showing 6 changed files with 211 additions and 0 deletions.
14 changes: 14 additions & 0 deletions include/net/cfg80211.h
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Original file line number Diff line number Diff line change
Expand Up @@ -2367,6 +2367,12 @@ struct cfg80211_qos_map {
* (invoked with the wireless_dev mutex held)
* @leave_ocb: leave the current OCB network
* (invoked with the wireless_dev mutex held)
*
* @tdls_channel_switch: Start channel-switching with a TDLS peer. The driver
* is responsible for continually initiating channel-switching operations
* and returning to the base channel for communication with the AP.
* @tdls_cancel_channel_switch: Stop channel-switching with a TDLS peer. Both
* peers must be on the base channel when the call completes.
*/
struct cfg80211_ops {
int (*suspend)(struct wiphy *wiphy, struct cfg80211_wowlan *wow);
Expand Down Expand Up @@ -2622,6 +2628,14 @@ struct cfg80211_ops {
u16 admitted_time);
int (*del_tx_ts)(struct wiphy *wiphy, struct net_device *dev,
u8 tsid, const u8 *peer);

int (*tdls_channel_switch)(struct wiphy *wiphy,
struct net_device *dev,
const u8 *addr, u8 oper_class,
struct cfg80211_chan_def *chandef);
void (*tdls_cancel_channel_switch)(struct wiphy *wiphy,
struct net_device *dev,
const u8 *addr);
};

/*
Expand Down
19 changes: 19 additions & 0 deletions include/uapi/linux/nl80211.h
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Original file line number Diff line number Diff line change
Expand Up @@ -762,6 +762,18 @@
* @NL80211_CMD_LEAVE_OCB: Leave the OCB network -- no special arguments, the
* network is determined by the network interface.
*
* @NL80211_CMD_TDLS_CHANNEL_SWITCH: Start channel-switching with a TDLS peer,
* identified by the %NL80211_ATTR_MAC parameter. A target channel is
* provided via %NL80211_ATTR_WIPHY_FREQ and other attributes determining
* channel width/type. The target operating class is given via
* %NL80211_ATTR_OPER_CLASS.
* The driver is responsible for continually initiating channel-switching
* operations and returning to the base channel for communication with the
* AP.
* @NL80211_CMD_TDLS_CANCEL_CHANNEL_SWITCH: Stop channel-switching with a TDLS
* peer given by %NL80211_ATTR_MAC. Both peers must be on the base channel
* when this command completes.
*
* @NL80211_CMD_MAX: highest used command number
* @__NL80211_CMD_AFTER_LAST: internal use
*/
Expand Down Expand Up @@ -943,6 +955,9 @@ enum nl80211_commands {

NL80211_CMD_CH_SWITCH_STARTED_NOTIFY,

NL80211_CMD_TDLS_CHANNEL_SWITCH,
NL80211_CMD_TDLS_CANCEL_CHANNEL_SWITCH,

/* add new commands above here */

/* used to define NL80211_CMD_MAX below */
Expand Down Expand Up @@ -1669,6 +1684,8 @@ enum nl80211_commands {
* @NL80211_ATTR_SMPS_MODE: SMPS mode to use (ap mode). see
* &enum nl80211_smps_mode.
*
* @NL80211_ATTR_OPER_CLASS: operating class
*
* @NL80211_ATTR_MAX: highest attribute number currently defined
* @__NL80211_ATTR_AFTER_LAST: internal use
*/
Expand Down Expand Up @@ -2021,6 +2038,8 @@ enum nl80211_attrs {

NL80211_ATTR_SMPS_MODE,

NL80211_ATTR_OPER_CLASS,

/* add attributes here, update the policy in nl80211.c */

__NL80211_ATTR_AFTER_LAST,
Expand Down
4 changes: 4 additions & 0 deletions net/wireless/core.c
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Original file line number Diff line number Diff line change
Expand Up @@ -541,6 +541,10 @@ int wiphy_register(struct wiphy *wiphy)
!wiphy->wowlan->tcp))
return -EINVAL;
#endif
if (WARN_ON((wiphy->features & NL80211_FEATURE_TDLS_CHANNEL_SWITCH) &&
(!rdev->ops->tdls_channel_switch ||
!rdev->ops->tdls_cancel_channel_switch)))
return -EINVAL;

if (WARN_ON(wiphy->coalesce &&
(!wiphy->coalesce->n_rules ||
Expand Down
108 changes: 108 additions & 0 deletions net/wireless/nl80211.c
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Original file line number Diff line number Diff line change
Expand Up @@ -9658,6 +9658,98 @@ static int nl80211_del_tx_ts(struct sk_buff *skb, struct genl_info *info)
return err;
}

static int nl80211_tdls_channel_switch(struct sk_buff *skb,
struct genl_info *info)
{
struct cfg80211_registered_device *rdev = info->user_ptr[0];
struct net_device *dev = info->user_ptr[1];
struct wireless_dev *wdev = dev->ieee80211_ptr;
struct cfg80211_chan_def chandef = {};
const u8 *addr;
u8 oper_class;
int err;

if (!rdev->ops->tdls_channel_switch ||
!(rdev->wiphy.features & NL80211_FEATURE_TDLS_CHANNEL_SWITCH))
return -EOPNOTSUPP;

switch (dev->ieee80211_ptr->iftype) {
case NL80211_IFTYPE_STATION:
case NL80211_IFTYPE_P2P_CLIENT:
break;
default:
return -EOPNOTSUPP;
}

if (!info->attrs[NL80211_ATTR_MAC] ||
!info->attrs[NL80211_ATTR_OPER_CLASS])
return -EINVAL;

err = nl80211_parse_chandef(rdev, info, &chandef);
if (err)
return err;

/*
* Don't allow wide channels on the 2.4Ghz band, as per IEEE802.11-2012
* section 10.22.6.2.1. Disallow 5/10Mhz channels as well for now, the
* specification is not defined for them.
*/
if (chandef.chan->band == IEEE80211_BAND_2GHZ &&
chandef.width != NL80211_CHAN_WIDTH_20_NOHT &&
chandef.width != NL80211_CHAN_WIDTH_20)
return -EINVAL;

/* we will be active on the TDLS link */
if (!cfg80211_reg_can_beacon(&rdev->wiphy, &chandef, wdev->iftype))
return -EINVAL;

/* don't allow switching to DFS channels */
if (cfg80211_chandef_dfs_required(wdev->wiphy, &chandef, wdev->iftype))
return -EINVAL;

addr = nla_data(info->attrs[NL80211_ATTR_MAC]);
oper_class = nla_get_u8(info->attrs[NL80211_ATTR_OPER_CLASS]);

wdev_lock(wdev);
err = rdev_tdls_channel_switch(rdev, dev, addr, oper_class, &chandef);
wdev_unlock(wdev);

return err;
}

static int nl80211_tdls_cancel_channel_switch(struct sk_buff *skb,
struct genl_info *info)
{
struct cfg80211_registered_device *rdev = info->user_ptr[0];
struct net_device *dev = info->user_ptr[1];
struct wireless_dev *wdev = dev->ieee80211_ptr;
const u8 *addr;

if (!rdev->ops->tdls_channel_switch ||
!rdev->ops->tdls_cancel_channel_switch ||
!(rdev->wiphy.features & NL80211_FEATURE_TDLS_CHANNEL_SWITCH))
return -EOPNOTSUPP;

switch (dev->ieee80211_ptr->iftype) {
case NL80211_IFTYPE_STATION:
case NL80211_IFTYPE_P2P_CLIENT:
break;
default:
return -EOPNOTSUPP;
}

if (!info->attrs[NL80211_ATTR_MAC])
return -EINVAL;

addr = nla_data(info->attrs[NL80211_ATTR_MAC]);

wdev_lock(wdev);
rdev_tdls_cancel_channel_switch(rdev, dev, addr);
wdev_unlock(wdev);

return 0;
}

#define NL80211_FLAG_NEED_WIPHY 0x01
#define NL80211_FLAG_NEED_NETDEV 0x02
#define NL80211_FLAG_NEED_RTNL 0x04
Expand Down Expand Up @@ -10456,6 +10548,22 @@ static const struct genl_ops nl80211_ops[] = {
.internal_flags = NL80211_FLAG_NEED_NETDEV_UP |
NL80211_FLAG_NEED_RTNL,
},
{
.cmd = NL80211_CMD_TDLS_CHANNEL_SWITCH,
.doit = nl80211_tdls_channel_switch,
.policy = nl80211_policy,
.flags = GENL_ADMIN_PERM,
.internal_flags = NL80211_FLAG_NEED_NETDEV_UP |
NL80211_FLAG_NEED_RTNL,
},
{
.cmd = NL80211_CMD_TDLS_CANCEL_CHANNEL_SWITCH,
.doit = nl80211_tdls_cancel_channel_switch,
.policy = nl80211_policy,
.flags = GENL_ADMIN_PERM,
.internal_flags = NL80211_FLAG_NEED_NETDEV_UP |
NL80211_FLAG_NEED_RTNL,
},
};

/* notification functions */
Expand Down
24 changes: 24 additions & 0 deletions net/wireless/rdev-ops.h
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Original file line number Diff line number Diff line change
Expand Up @@ -993,4 +993,28 @@ rdev_del_tx_ts(struct cfg80211_registered_device *rdev,
return ret;
}

static inline int
rdev_tdls_channel_switch(struct cfg80211_registered_device *rdev,
struct net_device *dev, const u8 *addr,
u8 oper_class, struct cfg80211_chan_def *chandef)
{
int ret;

trace_rdev_tdls_channel_switch(&rdev->wiphy, dev, addr, oper_class,
chandef);
ret = rdev->ops->tdls_channel_switch(&rdev->wiphy, dev, addr,
oper_class, chandef);
trace_rdev_return_int(&rdev->wiphy, ret);
return ret;
}

static inline void
rdev_tdls_cancel_channel_switch(struct cfg80211_registered_device *rdev,
struct net_device *dev, const u8 *addr)
{
trace_rdev_tdls_cancel_channel_switch(&rdev->wiphy, dev, addr);
rdev->ops->tdls_cancel_channel_switch(&rdev->wiphy, dev, addr);
trace_rdev_return_void(&rdev->wiphy);
}

#endif /* __CFG80211_RDEV_OPS */
42 changes: 42 additions & 0 deletions net/wireless/trace.h
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Original file line number Diff line number Diff line change
Expand Up @@ -2032,6 +2032,48 @@ TRACE_EVENT(rdev_del_tx_ts,
WIPHY_PR_ARG, NETDEV_PR_ARG, MAC_PR_ARG(peer), __entry->tsid)
);

TRACE_EVENT(rdev_tdls_channel_switch,
TP_PROTO(struct wiphy *wiphy, struct net_device *netdev,
const u8 *addr, u8 oper_class,
struct cfg80211_chan_def *chandef),
TP_ARGS(wiphy, netdev, addr, oper_class, chandef),
TP_STRUCT__entry(
WIPHY_ENTRY
NETDEV_ENTRY
MAC_ENTRY(addr)
__field(u8, oper_class)
CHAN_DEF_ENTRY
),
TP_fast_assign(
WIPHY_ASSIGN;
NETDEV_ASSIGN;
MAC_ASSIGN(addr, addr);
CHAN_DEF_ASSIGN(chandef);
),
TP_printk(WIPHY_PR_FMT ", " NETDEV_PR_FMT ", " MAC_PR_FMT
" oper class %d, " CHAN_DEF_PR_FMT,
WIPHY_PR_ARG, NETDEV_PR_ARG, MAC_PR_ARG(addr),
__entry->oper_class, CHAN_DEF_PR_ARG)
);

TRACE_EVENT(rdev_tdls_cancel_channel_switch,
TP_PROTO(struct wiphy *wiphy, struct net_device *netdev,
const u8 *addr),
TP_ARGS(wiphy, netdev, addr),
TP_STRUCT__entry(
WIPHY_ENTRY
NETDEV_ENTRY
MAC_ENTRY(addr)
),
TP_fast_assign(
WIPHY_ASSIGN;
NETDEV_ASSIGN;
MAC_ASSIGN(addr, addr);
),
TP_printk(WIPHY_PR_FMT ", " NETDEV_PR_FMT ", " MAC_PR_FMT,
WIPHY_PR_ARG, NETDEV_PR_ARG, MAC_PR_ARG(addr))
);

/*************************************************************
* cfg80211 exported functions traces *
*************************************************************/
Expand Down

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