by Arik Nemtsov

[permalink] [raw]

Subject: [PATCH 11/16] cfg80211: introduce TDLS channel switch commands

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 <[email protected]>
Reviewed-by: Johannes Berg <[email protected]>
Signed-off-by: Arik Nemtsov <[email protected]>
---
include/net/cfg80211.h | 8 ++++
include/net/cfg80211.h.rej | 15 ++++++
include/uapi/linux/nl80211.h | 17 +++++++
net/wireless/core.c | 4 ++
net/wireless/nl80211.c | 108 +++++++++++++++++++++++++++++++++++++++++++
net/wireless/rdev-ops.h | 24 ++++++++++
net/wireless/trace.h | 42 +++++++++++++++++
7 files changed, 218 insertions(+)
create mode 100644 include/net/cfg80211.h.rej

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 5c3acd0..62cdac0 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -2622,6 +2622,14 @@ 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);
};

/*
diff --git a/include/net/cfg80211.h.rej b/include/net/cfg80211.h.rej
new file mode 100644
index 0000000..44fd4a9c
--- /dev/null
+++ b/include/net/cfg80211.h.rej
@@ -0,0 +1,15 @@
+--- include/net/cfg80211.h
++++ include/net/cfg80211.h
+@@ -2331,6 +2331,12 @@
+ * with the peer followed by immediate teardown when the addition is later
+ * rejected)
+ * @del_tx_ts: remove an existing TX TS
++ *
++ * @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);
diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h
index e7f01d6..c2df1e0 100644
--- a/include/uapi/linux/nl80211.h
+++ b/include/uapi/linux/nl80211.h
@@ -751,6 +751,18 @@
* @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
*/
@@ -930,6 +942,9 @@ enum nl80211_commands {
NL80211_CMD_JOIN_OCB,
NL80211_CMD_LEAVE_OCB,

+ NL80211_CMD_TDLS_CHANNEL_SWITCH,
+ NL80211_CMD_TDLS_CANCEL_CHANNEL_SWITCH,
+
/* add new commands above here */

/* used to define NL80211_CMD_MAX below */
@@ -2008,6 +2023,8 @@ enum nl80211_attrs {

NL80211_ATTR_SMPS_MODE,

+ NL80211_ATTR_OPER_CLASS,
+
/* add attributes here, update the policy in nl80211.c */

__NL80211_ATTR_AFTER_LAST,
diff --git a/net/wireless/core.c b/net/wireless/core.c
index a4d2792..4c2e501 100644
--- a/net/wireless/core.c
+++ b/net/wireless/core.c
@@ -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 ||
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 24549cb..328c45b 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -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
@@ -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 */
diff --git a/net/wireless/rdev-ops.h b/net/wireless/rdev-ops.h
index 1b3864c..35cfb71 100644
--- a/net/wireless/rdev-ops.h
+++ b/net/wireless/rdev-ops.h
@@ -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 */
diff --git a/net/wireless/trace.h b/net/wireless/trace.h
index 277a85d..f0545e1 100644
--- a/net/wireless/trace.h
+++ b/net/wireless/trace.h
@@ -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 *
*************************************************************/
--
1.9.1