2012-04-04 22:31:46

by Thomas Pedersen

[permalink] [raw]
Subject: [PATCH v2 1/2] cfg80211: add channel switch notify event

The firmware may decide to switch channels while already beaconing, e.g.
in response to a cfg80211 connect request on a different vif. Add this
event to notify userspace when an AP or GO interface has successfully
migrated to a new channel, so it can update its configuration
accordingly.

Signed-off-by: Thomas Pedersen <[email protected]>
---
v2: update wdev->channel (Johannes)
enforce AP or GO interface type

include/linux/nl80211.h | 7 +++++++
include/net/cfg80211.h | 10 ++++++++++
net/wireless/mlme.c | 27 +++++++++++++++++++++++++++
net/wireless/nl80211.c | 32 ++++++++++++++++++++++++++++++++
net/wireless/nl80211.h | 4 ++++
5 files changed, 80 insertions(+), 0 deletions(-)

diff --git a/include/linux/nl80211.h b/include/linux/nl80211.h
index e474f6e..49f2bbe 100644
--- a/include/linux/nl80211.h
+++ b/include/linux/nl80211.h
@@ -548,6 +548,11 @@
* @NL80211_CMD_SET_NOACK_MAP: sets a bitmap for the individual TIDs whether
* No Acknowledgement Policy should be applied.
*
+ * @NL80211_CMD_CH_SWITCH_NOTIFY: An AP or GO may decide to switch channels
+ * independently of the userspace SME, send this event indicating
+ * %NL80211_ATTR_IFINDEX is now on %NL80211_ATTR_WIPHY_FREQ with
+ * %NL80211_ATTR_WIPHY_CHANNEL_TYPE.
+ *
* @NL80211_CMD_MAX: highest used command number
* @__NL80211_CMD_AFTER_LAST: internal use
*/
@@ -689,6 +694,8 @@ enum nl80211_commands {

NL80211_CMD_SET_NOACK_MAP,

+ NL80211_CMD_CH_SWITCH_NOTIFY,
+
/* add new commands above here */

/* used to define NL80211_CMD_MAX below */
diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 69b7ad3..eadc897 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -3340,6 +3340,16 @@ int cfg80211_can_beacon_sec_chan(struct wiphy *wiphy,
enum nl80211_channel_type channel_type);

/*
+ * cfg80211_ch_switch_notify - notify userspace about netdev channel switch
+ * @dev: the device which switched channels
+ * @freq: new channel frequency (in MHz)
+ * @type: channel type
+ * @gfp: allocation flags
+ */
+void cfg80211_ch_switch_notify(struct net_device *dev, int freq,
+ enum nl80211_channel_type type, gfp_t gfp);
+
+/*
* cfg80211_calculate_bitrate - calculate actual bitrate (in 100Kbps units)
* @rate: given rate_info to calculate bitrate from
*
diff --git a/net/wireless/mlme.c b/net/wireless/mlme.c
index f5a7ac3..4d45296 100644
--- a/net/wireless/mlme.c
+++ b/net/wireless/mlme.c
@@ -928,6 +928,33 @@ void cfg80211_pmksa_candidate_notify(struct net_device *dev, int index,
}
EXPORT_SYMBOL(cfg80211_pmksa_candidate_notify);

+void cfg80211_ch_switch_notify(struct net_device *dev, int freq,
+ enum nl80211_channel_type type, gfp_t gfp)
+{
+ struct wireless_dev *wdev = dev->ieee80211_ptr;
+ struct wiphy *wiphy = wdev->wiphy;
+ struct cfg80211_registered_device *rdev = wiphy_to_dev(wiphy);
+ struct ieee80211_channel *chan;
+
+ wdev_lock(wdev);
+
+ if (WARN_ON(wdev->iftype != NL80211_IFTYPE_AP &&
+ wdev->iftype != NL80211_IFTYPE_P2P_GO))
+ goto out;
+
+ chan = rdev_freq_to_chan(rdev, freq, type);
+ if (WARN_ON(!chan))
+ goto out;
+
+ wdev->channel = chan;
+
+ nl80211_ch_switch_notify(rdev, dev, freq, type, gfp);
+out:
+ wdev_unlock(wdev);
+ return;
+}
+EXPORT_SYMBOL(cfg80211_ch_switch_notify);
+
bool cfg80211_rx_spurious_frame(struct net_device *dev,
const u8 *addr, gfp_t gfp)
{
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 4c1eb94..d5d489f 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -7890,6 +7890,38 @@ void nl80211_pmksa_candidate_notify(struct cfg80211_registered_device *rdev,
nlmsg_free(msg);
}

+void nl80211_ch_switch_notify(struct cfg80211_registered_device *rdev,
+ struct net_device *netdev, int freq,
+ enum nl80211_channel_type type, gfp_t gfp)
+{
+ struct sk_buff *msg;
+ void *hdr;
+
+ msg = nlmsg_new(NLMSG_GOODSIZE, gfp);
+ if (!msg)
+ return;
+
+ hdr = nl80211hdr_put(msg, 0, 0, 0, NL80211_CMD_CH_SWITCH_NOTIFY);
+ if (!hdr) {
+ nlmsg_free(msg);
+ return;
+ }
+
+ NLA_PUT_U32(msg, NL80211_ATTR_IFINDEX, netdev->ifindex);
+ NLA_PUT_U32(msg, NL80211_ATTR_WIPHY_FREQ, freq);
+ NLA_PUT_U32(msg, NL80211_ATTR_WIPHY_CHANNEL_TYPE, type);
+
+ genlmsg_end(msg, hdr);
+
+ genlmsg_multicast_netns(wiphy_net(&rdev->wiphy), msg, 0,
+ nl80211_mlme_mcgrp.id, gfp);
+ return;
+
+ nla_put_failure:
+ genlmsg_cancel(msg, hdr);
+ nlmsg_free(msg);
+}
+
void
nl80211_send_cqm_pktloss_notify(struct cfg80211_registered_device *rdev,
struct net_device *netdev, const u8 *peer,
diff --git a/net/wireless/nl80211.h b/net/wireless/nl80211.h
index 4ffe50d..01a1122 100644
--- a/net/wireless/nl80211.h
+++ b/net/wireless/nl80211.h
@@ -118,6 +118,10 @@ void nl80211_pmksa_candidate_notify(struct cfg80211_registered_device *rdev,
struct net_device *netdev, int index,
const u8 *bssid, bool preauth, gfp_t gfp);

+void nl80211_ch_switch_notify(struct cfg80211_registered_device *rdev,
+ struct net_device *dev, int freq,
+ enum nl80211_channel_type type, gfp_t gfp);
+
bool nl80211_unexpected_frame(struct net_device *dev,
const u8 *addr, gfp_t gfp);
bool nl80211_unexpected_4addr_frame(struct net_device *dev,
--
1.7.4.1



2012-04-05 07:51:57

by Johannes Berg

[permalink] [raw]
Subject: Re: [PATCH v2 1/2] cfg80211: add channel switch notify event

On Wed, 2012-04-04 at 15:31 -0700, Thomas Pedersen wrote:

> +void cfg80211_ch_switch_notify(struct net_device *dev, int freq,
> + enum nl80211_channel_type type, gfp_t gfp)

> + wdev_lock(wdev);

So ... typically we pass the gfp_t since we want to allow these being
called in atomic contexts, but now you use the lock so that's impossible
anyway.

I think this is a bit dangerous. If you call this function from within a
context where cfg80211 calls you, for example, you will deadlock.

At least add more documentation about that :)

johannes


2012-04-04 22:31:49

by Thomas Pedersen

[permalink] [raw]
Subject: [PATCH v2 2/2] ath6kl: handle concurrent AP-STA channel switches

If an ath6kl AP vif is beaconing on one channel, and a STA vif
associates on a different channel, a WMI_DISCONNECT event will be sent
to the AP vif. Make the AP vif follow the STA interface, and notify
userspace.

Signed-off-by: Thomas Pedersen <[email protected]>
---
v2: coalesce formats (Joe)

drivers/net/wireless/ath/ath6kl/cfg80211.c | 15 ++++++++
drivers/net/wireless/ath/ath6kl/cfg80211.h | 2 +
drivers/net/wireless/ath/ath6kl/core.h | 2 +
drivers/net/wireless/ath/ath6kl/main.c | 55 +++++++++++++++++++++++++++-
drivers/net/wireless/ath/ath6kl/wmi.h | 12 ++++++
5 files changed, 85 insertions(+), 1 deletions(-)

diff --git a/drivers/net/wireless/ath/ath6kl/cfg80211.c b/drivers/net/wireless/ath/ath6kl/cfg80211.c
index 1272508..76c9401 100644
--- a/drivers/net/wireless/ath/ath6kl/cfg80211.c
+++ b/drivers/net/wireless/ath/ath6kl/cfg80211.c
@@ -1015,6 +1015,20 @@ out:
vif->scan_req = NULL;
}

+void ath6kl_cfg80211_ch_switch_notify(struct ath6kl_vif *vif, int freq,
+ enum wmi_phy_mode mode)
+{
+ enum nl80211_channel_type type;
+
+ ath6kl_dbg(ATH6KL_DBG_WLAN_CFG,
+ "channel switch notify nw_type %d freq %d mode %d\n",
+ vif->nw_type, freq, mode);
+
+ type = (mode == WMI_11G_HT20) ? NL80211_CHAN_HT20 : NL80211_CHAN_NO_HT;
+
+ cfg80211_ch_switch_notify(vif->ndev, freq, type, GFP_KERNEL);
+}
+
static int ath6kl_cfg80211_add_key(struct wiphy *wiphy, struct net_device *ndev,
u8 key_index, bool pairwise,
const u8 *mac_addr,
@@ -2643,6 +2657,7 @@ static int ath6kl_start_ap(struct wiphy *wiphy, struct net_device *dev,
return res;
}

+ memcpy(&vif->profile, &p, sizeof(p));
res = ath6kl_wmi_ap_profile_commit(ar->wmi, vif->fw_vif_idx, &p);
if (res < 0)
return res;
diff --git a/drivers/net/wireless/ath/ath6kl/cfg80211.h b/drivers/net/wireless/ath/ath6kl/cfg80211.h
index c5def43..5ea8cbb 100644
--- a/drivers/net/wireless/ath/ath6kl/cfg80211.h
+++ b/drivers/net/wireless/ath/ath6kl/cfg80211.h
@@ -28,6 +28,8 @@ enum ath6kl_cfg_suspend_mode {
struct net_device *ath6kl_interface_add(struct ath6kl *ar, char *name,
enum nl80211_iftype type,
u8 fw_vif_idx, u8 nw_type);
+void ath6kl_cfg80211_ch_switch_notify(struct ath6kl_vif *vif, int freq,
+ enum wmi_phy_mode mode);
void ath6kl_cfg80211_scan_complete_event(struct ath6kl_vif *vif, bool aborted);

void ath6kl_cfg80211_connect_event(struct ath6kl_vif *vif, u16 channel,
diff --git a/drivers/net/wireless/ath/ath6kl/core.h b/drivers/net/wireless/ath/ath6kl/core.h
index 75b1d86..0b4078d 100644
--- a/drivers/net/wireless/ath/ath6kl/core.h
+++ b/drivers/net/wireless/ath/ath6kl/core.h
@@ -540,6 +540,7 @@ struct ath6kl_vif {
u8 assoc_bss_dtim_period;
struct net_device_stats net_stats;
struct target_stats target_stats;
+ struct wmi_connect_cmd profile;

struct list_head mc_filter;
};
@@ -628,6 +629,7 @@ struct ath6kl {
u8 sta_list_index;
struct ath6kl_req_key ap_mode_bkey;
struct sk_buff_head mcastpsq;
+ u32 want_ch_switch;

/*
* FIXME: protects access to mcastpsq but is actually useless as
diff --git a/drivers/net/wireless/ath/ath6kl/main.c b/drivers/net/wireless/ath/ath6kl/main.c
index 7f3addd..58468e0 100644
--- a/drivers/net/wireless/ath/ath6kl/main.c
+++ b/drivers/net/wireless/ath/ath6kl/main.c
@@ -434,6 +434,13 @@ void ath6kl_connect_ap_mode_bss(struct ath6kl_vif *vif, u16 channel)
break;
}

+ if (ar->want_ch_switch & (1 << vif->fw_vif_idx)) {
+ ar->want_ch_switch &= ~(1 << vif->fw_vif_idx);
+ /* we actually don't know the phymode, default to HT20 */
+ ath6kl_cfg80211_ch_switch_notify(vif, channel,
+ WMI_11G_HT20);
+ }
+
ath6kl_wmi_bssfilter_cmd(ar->wmi, vif->fw_vif_idx, NONE_BSS_FILTER, 0);
set_bit(CONNECTED, &vif->flags);
netif_carrier_on(vif->ndev);
@@ -582,6 +589,45 @@ void ath6kl_scan_complete_evt(struct ath6kl_vif *vif, int status)
ath6kl_dbg(ATH6KL_DBG_WLAN_CFG, "scan complete: %d\n", status);
}

+static int ath6kl_commit_ch_switch(struct ath6kl_vif *vif, u16 channel)
+{
+
+ struct ath6kl *ar = vif->ar;
+
+ vif->next_chan = cpu_to_le16(channel);
+ vif->profile.ch = cpu_to_le16(channel);
+
+ switch (vif->nw_type) {
+ case AP_NETWORK:
+ return ath6kl_wmi_ap_profile_commit(ar->wmi, vif->fw_vif_idx,
+ &vif->profile);
+ default:
+ ath6kl_err("won't switch channels nw_type=%d\n", vif->nw_type);
+ return -ENOTSUPP;
+ }
+}
+
+static void ath6kl_check_ch_switch(struct ath6kl *ar, u16 channel)
+{
+
+ struct ath6kl_vif *vif;
+ int res = 0;
+
+ if (!ar->want_ch_switch)
+ return;
+
+ spin_lock_bh(&ar->list_lock);
+ list_for_each_entry(vif, &ar->vif_list, list) {
+ if (ar->want_ch_switch & (1 << vif->fw_vif_idx))
+ res = ath6kl_commit_ch_switch(vif, channel);
+
+ if (res)
+ ath6kl_err("channel switch failed nw_type %d res %d\n",
+ vif->nw_type, res);
+ }
+ spin_unlock_bh(&ar->list_lock);
+}
+
void ath6kl_connect_event(struct ath6kl_vif *vif, u16 channel, u8 *bssid,
u16 listen_int, u16 beacon_int,
enum network_type net_type, u8 beacon_ie_len,
@@ -599,9 +645,11 @@ void ath6kl_connect_event(struct ath6kl_vif *vif, u16 channel, u8 *bssid,
memcpy(vif->bssid, bssid, sizeof(vif->bssid));
vif->bss_ch = channel;

- if ((vif->nw_type == INFRA_NETWORK))
+ if ((vif->nw_type == INFRA_NETWORK)) {
ath6kl_wmi_listeninterval_cmd(ar->wmi, vif->fw_vif_idx,
vif->listen_intvl_t, 0);
+ ath6kl_check_ch_switch(ar, channel);
+ }

netif_wake_queue(vif->ndev);

@@ -924,6 +972,11 @@ void ath6kl_disconnect_event(struct ath6kl_vif *vif, u8 reason, u8 *bssid,
struct ath6kl *ar = vif->ar;

if (vif->nw_type == AP_NETWORK) {
+ /* disconnect due to other STA vif switching channels */
+ if (reason == BSS_DISCONNECTED &&
+ prot_reason_status == WMI_AP_REASON_STA_ROAM)
+ ar->want_ch_switch |= 1 << vif->fw_vif_idx;
+
if (!ath6kl_remove_sta(ar, bssid, prot_reason_status))
return;

diff --git a/drivers/net/wireless/ath/ath6kl/wmi.h b/drivers/net/wireless/ath/ath6kl/wmi.h
index b99e9bd..88a1603 100644
--- a/drivers/net/wireless/ath/ath6kl/wmi.h
+++ b/drivers/net/wireless/ath/ath6kl/wmi.h
@@ -1145,6 +1145,7 @@ enum wmi_phy_mode {
WMI_11AG_MODE = 0x3,
WMI_11B_MODE = 0x4,
WMI_11GONLY_MODE = 0x5,
+ WMI_11G_HT20 = 0x6,
};

#define WMI_MAX_CHANNELS 32
@@ -1452,6 +1453,17 @@ enum wmi_disconnect_reason {
IBSS_MERGE = 0xe,
};

+/* AP mode disconnect proto_reasons */
+enum ap_disconnect_reason {
+ WMI_AP_REASON_STA_LEFT = 101,
+ WMI_AP_REASON_FROM_HOST = 102,
+ WMI_AP_REASON_COMM_TIMEOUT = 103,
+ WMI_AP_REASON_MAX_STA = 104,
+ WMI_AP_REASON_ACL = 105,
+ WMI_AP_REASON_STA_ROAM = 106,
+ WMI_AP_REASON_DFS_CHANNEL = 107,
+};
+
#define ATH6KL_COUNTRY_RD_SHIFT 16

struct ath6kl_wmi_regdomain {
--
1.7.4.1