Re: [PATCH v8 1/2] wireless: Support ht-capabilities over-rides.

[Johannes Berg <johannes@sipsolutions.net>]

On Tue, 2011-11-08 at 11:36 -0800, greearb@candelatech.com wrote:
> From: Ben Greear <greearb@candelatech.com>
> 
> This allows users to disable features such as HT, HT40,
> and to modify the MCS, AMPDU, and AMSDU settings for
> drivers that support it.
> 
> The MCS, AMPDU, and AMSDU features that may be disabled are
> are reported in the phy-info netlink message as a mask.
> 
> Attemping to disable features that are not supported will
> take no affect, but will not return errors.  This is to aid
> backwards compatibility in user-space apps that may not be
> clever enough to deal with parsing the the capabilities mask.
> 
> This patch only enables the infrastructure.  An additional
> patch will enable the feature in mac80211.

Looks ok to me now.

> Signed-off-by: Ben Greear <greearb@candelatech.com>
> ---
> 
> v8:  Fix compile bugs from v7.  Must have compiled the
>      wrong tree while testing that.
> 
> :100644 100644 8049bf7... 34c3973... M	include/linux/nl80211.h
> :100644 100644 92cf1c2... 5598b91... M	include/net/cfg80211.h
> :100644 100644 b9ec306... 8357ed6... M	net/wireless/core.h
> :100644 100644 21fc970... bf538e1... M	net/wireless/mlme.c
> :100644 100644 b3a476f... 31f17c8... M	net/wireless/nl80211.c
> :100644 100644 6e86d5a... ed9d0e6... M	net/wireless/sme.c
>  include/linux/nl80211.h |   15 +++++++++++++++
>  include/net/cfg80211.h  |   28 ++++++++++++++++++++++++++++
>  net/wireless/core.h     |   10 ++++++++--
>  net/wireless/mlme.c     |   37 ++++++++++++++++++++++++++++++++++---
>  net/wireless/nl80211.c  |   44 +++++++++++++++++++++++++++++++++++++++++++-
>  net/wireless/sme.c      |    7 ++++++-
>  6 files changed, 134 insertions(+), 7 deletions(-)
> 
> diff --git a/include/linux/nl80211.h b/include/linux/nl80211.h
> index 8049bf7..34c3973 100644
> --- a/include/linux/nl80211.h
> +++ b/include/linux/nl80211.h
> @@ -1109,6 +1109,18 @@ enum nl80211_commands {
>   *	%NL80211_CMD_TDLS_MGMT. Otherwise %NL80211_CMD_TDLS_OPER should be
>   *	used for asking the driver to perform a TDLS operation.
>   *
> + * @NL80211_ATTR_DISABLE_HT:  Force HT capable interfaces to disable
> + *      this feature.  Currently, only supported in mac80211 drivers.
> + * @NL80211_ATTR_HT_CAPABILITY_MASK: Specify which bits of the
> + *      ATTR_HT_CAPABILITY to which attention should be paid.
> + *      Currently, only mac80211 NICs support this feature.
> + *      The values that may be configured are:
> + *       MCS rates, MAX-AMSDU, HT-20-40 and HT_CAP_SGI_40
> + *       AMPDU density and AMPDU factor.
> + *      All values are treated as suggestions and may be ignored
> + *      by the driver as required.  The actual values may be seen in
> + *      the station debugfs ht_caps file.
> + *
>   * @NL80211_ATTR_MAX: highest attribute number currently defined
>   * @__NL80211_ATTR_AFTER_LAST: internal use
>   */
> @@ -1337,6 +1349,9 @@ enum nl80211_attrs {
>  	NL80211_ATTR_TDLS_SUPPORT,
>  	NL80211_ATTR_TDLS_EXTERNAL_SETUP,
>  
> +	NL80211_ATTR_DISABLE_HT,
> +	NL80211_ATTR_HT_CAPABILITY_MASK,
> +
>  	/* add attributes here, update the policy in nl80211.c */
>  
>  	__NL80211_ATTR_AFTER_LAST,
> diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
> index 92cf1c2..5598b91 100644
> --- a/include/net/cfg80211.h
> +++ b/include/net/cfg80211.h
> @@ -1036,6 +1036,15 @@ struct cfg80211_auth_request {
>  };
>  
>  /**
> + * enum cfg80211_assoc_req_flags - Over-ride default behaviour in association.
> + *
> + * @ASSOC_REQ_DISABLE_HT:  Disable HT (802.11n)
> + */
> +enum cfg80211_assoc_req_flags {
> +	ASSOC_REQ_DISABLE_HT		= BIT(0),
> +};
> +
> +/**
>   * struct cfg80211_assoc_request - (Re)Association request data
>   *
>   * This structure provides information needed to complete IEEE 802.11
> @@ -1046,6 +1055,10 @@ struct cfg80211_auth_request {
>   * @use_mfp: Use management frame protection (IEEE 802.11w) in this association
>   * @crypto: crypto settings
>   * @prev_bssid: previous BSSID, if not %NULL use reassociate frame
> + * @flags:  See &enum cfg80211_assoc_req_flags
> + * @ht_capa:  HT Capabilities over-rides.  Values set in ht_capa_mask
> + *   will be used in ht_capa.  Un-supported values will be ignored.
> + * @ht_capa_mask:  The bits of ht_capa which are to be used.
>   */
>  struct cfg80211_assoc_request {
>  	struct cfg80211_bss *bss;
> @@ -1053,6 +1066,9 @@ struct cfg80211_assoc_request {
>  	size_t ie_len;
>  	struct cfg80211_crypto_settings crypto;
>  	bool use_mfp;
> +	u32 flags;
> +	struct ieee80211_ht_cap ht_capa;
> +	struct ieee80211_ht_cap ht_capa_mask;
>  };
>  
>  /**
> @@ -1151,6 +1167,10 @@ struct cfg80211_ibss_params {
>   * @key_len: length of WEP key for shared key authentication
>   * @key_idx: index of WEP key for shared key authentication
>   * @key: WEP key for shared key authentication
> + * @flags:  See &enum cfg80211_assoc_req_flags
> + * @ht_capa:  HT Capabilities over-rides.  Values set in ht_capa_mask
> + *   will be used in ht_capa.  Un-supported values will be ignored.
> + * @ht_capa_mask:  The bits of ht_capa which are to be used.
>   */
>  struct cfg80211_connect_params {
>  	struct ieee80211_channel *channel;
> @@ -1164,6 +1184,9 @@ struct cfg80211_connect_params {
>  	struct cfg80211_crypto_settings crypto;
>  	const u8 *key;
>  	u8 key_len, key_idx;
> +	u32 flags;
> +	struct ieee80211_ht_cap ht_capa;
> +	struct ieee80211_ht_cap ht_capa_mask;
>  };
>  
>  /**
> @@ -1903,6 +1926,9 @@ struct wiphy_wowlan_support {
>   *	may request, if implemented.
>   *
>   * @wowlan: WoWLAN support information
> + *
> + * @ht_capa_mod_mask:  Specify what ht_cap values can be over-ridden.
> + *	If null, then none can be over-ridden.
>   */
>  struct wiphy {
>  	/* assign these fields before you register the wiphy */
> @@ -1983,6 +2009,8 @@ struct wiphy {
>  	/* dir in debugfs: ieee80211/<wiphyname> */
>  	struct dentry *debugfsdir;
>  
> +	const struct ieee80211_ht_cap *ht_capa_mod_mask;
> +
>  #ifdef CONFIG_NET_NS
>  	/* the network namespace this phy lives in currently */
>  	struct net *_net;
> diff --git a/net/wireless/core.h b/net/wireless/core.h
> index b9ec306..8357ed6 100644
> --- a/net/wireless/core.h
> +++ b/net/wireless/core.h
> @@ -339,13 +339,17 @@ int __cfg80211_mlme_assoc(struct cfg80211_registered_device *rdev,
>  			  const u8 *bssid, const u8 *prev_bssid,
>  			  const u8 *ssid, int ssid_len,
>  			  const u8 *ie, int ie_len, bool use_mfp,
> -			  struct cfg80211_crypto_settings *crypt);
> +			  struct cfg80211_crypto_settings *crypt,
> +			  u32 assoc_flags, struct ieee80211_ht_cap *ht_capa,
> +			  struct ieee80211_ht_cap *ht_capa_mask);
>  int cfg80211_mlme_assoc(struct cfg80211_registered_device *rdev,
>  			struct net_device *dev, struct ieee80211_channel *chan,
>  			const u8 *bssid, const u8 *prev_bssid,
>  			const u8 *ssid, int ssid_len,
>  			const u8 *ie, int ie_len, bool use_mfp,
> -			struct cfg80211_crypto_settings *crypt);
> +			struct cfg80211_crypto_settings *crypt,
> +			u32 assoc_flags, struct ieee80211_ht_cap *ht_capa,
> +			struct ieee80211_ht_cap *ht_capa_mask);
>  int __cfg80211_mlme_deauth(struct cfg80211_registered_device *rdev,
>  			   struct net_device *dev, const u8 *bssid,
>  			   const u8 *ie, int ie_len, u16 reason,
> @@ -377,6 +381,8 @@ int cfg80211_mlme_mgmt_tx(struct cfg80211_registered_device *rdev,
>  			  bool channel_type_valid, unsigned int wait,
>  			  const u8 *buf, size_t len, bool no_cck,
>  			  u64 *cookie);
> +void cfg80211_oper_and_ht_capa(struct ieee80211_ht_cap *ht_capa,
> +			       const struct ieee80211_ht_cap *ht_capa_mask);
>  
>  /* SME */
>  int __cfg80211_connect(struct cfg80211_registered_device *rdev,
> diff --git a/net/wireless/mlme.c b/net/wireless/mlme.c
> index 21fc970..bf538e1 100644
> --- a/net/wireless/mlme.c
> +++ b/net/wireless/mlme.c
> @@ -501,13 +501,32 @@ int cfg80211_mlme_auth(struct cfg80211_registered_device *rdev,
>  	return err;
>  }
>  
> +/*  Do a logical ht_capa &= ht_capa_mask.  */
> +void cfg80211_oper_and_ht_capa(struct ieee80211_ht_cap *ht_capa,
> +			       const struct ieee80211_ht_cap *ht_capa_mask)
> +{
> +	int i;
> +	u8 *p1, *p2;
> +	if (!ht_capa_mask) {
> +		memset(ht_capa, 0, sizeof(*ht_capa));
> +		return;
> +	}
> +
> +	p1 = (u8*)(ht_capa);
> +	p2 = (u8*)(ht_capa_mask);
> +	for (i = 0; i<sizeof(*ht_capa); i++)
> +		p1[i] &= p2[i];
> +}
> +
>  int __cfg80211_mlme_assoc(struct cfg80211_registered_device *rdev,
>  			  struct net_device *dev,
>  			  struct ieee80211_channel *chan,
>  			  const u8 *bssid, const u8 *prev_bssid,
>  			  const u8 *ssid, int ssid_len,
>  			  const u8 *ie, int ie_len, bool use_mfp,
> -			  struct cfg80211_crypto_settings *crypt)
> +			  struct cfg80211_crypto_settings *crypt,
> +			  u32 assoc_flags, struct ieee80211_ht_cap *ht_capa,
> +			  struct ieee80211_ht_cap *ht_capa_mask)
>  {
>  	struct wireless_dev *wdev = dev->ieee80211_ptr;
>  	struct cfg80211_assoc_request req;
> @@ -537,6 +556,15 @@ int __cfg80211_mlme_assoc(struct cfg80211_registered_device *rdev,
>  	memcpy(&req.crypto, crypt, sizeof(req.crypto));
>  	req.use_mfp = use_mfp;
>  	req.prev_bssid = prev_bssid;
> +	req.flags = assoc_flags;
> +	if (ht_capa)
> +		memcpy(&req.ht_capa, ht_capa, sizeof(req.ht_capa));
> +	if (ht_capa_mask)
> +		memcpy(&req.ht_capa_mask, ht_capa_mask,
> +		       sizeof(req.ht_capa_mask));
> +	cfg80211_oper_and_ht_capa(&req.ht_capa_mask,
> +				  rdev->wiphy.ht_capa_mod_mask);
> +
>  	req.bss = cfg80211_get_bss(&rdev->wiphy, chan, bssid, ssid, ssid_len,
>  				   WLAN_CAPABILITY_ESS, WLAN_CAPABILITY_ESS);
>  	if (!req.bss) {
> @@ -574,14 +602,17 @@ int cfg80211_mlme_assoc(struct cfg80211_registered_device *rdev,
>  			const u8 *bssid, const u8 *prev_bssid,
>  			const u8 *ssid, int ssid_len,
>  			const u8 *ie, int ie_len, bool use_mfp,
> -			struct cfg80211_crypto_settings *crypt)
> +			struct cfg80211_crypto_settings *crypt,
> +			u32 assoc_flags, struct ieee80211_ht_cap *ht_capa,
> +			struct ieee80211_ht_cap *ht_capa_mask)
>  {
>  	struct wireless_dev *wdev = dev->ieee80211_ptr;
>  	int err;
>  
>  	wdev_lock(wdev);
>  	err = __cfg80211_mlme_assoc(rdev, dev, chan, bssid, prev_bssid,
> -				    ssid, ssid_len, ie, ie_len, use_mfp, crypt);
> +				    ssid, ssid_len, ie, ie_len, use_mfp, crypt,
> +				    assoc_flags, ht_capa, ht_capa_mask);
>  	wdev_unlock(wdev);
>  
>  	return err;
> diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
> index b3a476f..31f17c8 100644
> --- a/net/wireless/nl80211.c
> +++ b/net/wireless/nl80211.c
> @@ -196,6 +196,10 @@ static const struct nla_policy nl80211_policy[NL80211_ATTR_MAX+1] = {
>  	[NL80211_ATTR_TDLS_OPERATION] = { .type = NLA_U8 },
>  	[NL80211_ATTR_TDLS_SUPPORT] = { .type = NLA_FLAG },
>  	[NL80211_ATTR_TDLS_EXTERNAL_SETUP] = { .type = NLA_FLAG },
> +	[NL80211_ATTR_DISABLE_HT] = { .type = NLA_FLAG },
> +	[NL80211_ATTR_HT_CAPABILITY_MASK] = {
> +		.len = NL80211_HT_CAPABILITY_LEN
> +	},
>  };
>  
>  /* policy for the key attributes */
> @@ -1007,6 +1011,11 @@ static int nl80211_send_wiphy(struct sk_buff *msg, u32 pid, u32 seq, int flags,
>  	if (nl80211_put_iface_combinations(&dev->wiphy, msg))
>  		goto nla_put_failure;
>  
> +	if (dev->wiphy.ht_capa_mod_mask)
> +		NLA_PUT(msg, NL80211_ATTR_HT_CAPABILITY_MASK,
> +			sizeof(*dev->wiphy.ht_capa_mod_mask),
> +			dev->wiphy.ht_capa_mod_mask);
> +
>  	return genlmsg_end(msg, hdr);
>  
>   nla_put_failure:
> @@ -4359,6 +4368,9 @@ static int nl80211_associate(struct sk_buff *skb, struct genl_info *info)
>  	const u8 *bssid, *ssid, *ie = NULL, *prev_bssid = NULL;
>  	int err, ssid_len, ie_len = 0;
>  	bool use_mfp = false;
> +	u32 flags = 0;
> +	struct ieee80211_ht_cap *ht_capa = NULL;
> +	struct ieee80211_ht_cap *ht_capa_mask = NULL;
>  
>  	if (!is_valid_ie_attr(info->attrs[NL80211_ATTR_IE]))
>  		return -EINVAL;
> @@ -4402,11 +4414,25 @@ static int nl80211_associate(struct sk_buff *skb, struct genl_info *info)
>  	if (info->attrs[NL80211_ATTR_PREV_BSSID])
>  		prev_bssid = nla_data(info->attrs[NL80211_ATTR_PREV_BSSID]);
>  
> +	if (nla_get_flag(info->attrs[NL80211_ATTR_DISABLE_HT]))
> +		flags |= ASSOC_REQ_DISABLE_HT;
> +
> +	if (info->attrs[NL80211_ATTR_HT_CAPABILITY_MASK])
> +		ht_capa_mask =
> +			nla_data(info->attrs[NL80211_ATTR_HT_CAPABILITY_MASK]);
> +
> +	if (info->attrs[NL80211_ATTR_HT_CAPABILITY]) {
> +		if (!ht_capa_mask)
> +			return -EINVAL;
> +		ht_capa = nla_data(info->attrs[NL80211_ATTR_HT_CAPABILITY]);
> +	}
> +
>  	err = nl80211_crypto_settings(rdev, info, &crypto, 1);
>  	if (!err)
>  		err = cfg80211_mlme_assoc(rdev, dev, chan, bssid, prev_bssid,
>  					  ssid, ssid_len, ie, ie_len, use_mfp,
> -					  &crypto);
> +					  &crypto, flags, ht_capa,
> +					  ht_capa_mask);
>  
>  	return err;
>  }
> @@ -4896,6 +4922,22 @@ static int nl80211_connect(struct sk_buff *skb, struct genl_info *info)
>  			return PTR_ERR(connkeys);
>  	}
>  
> +	if (nla_get_flag(info->attrs[NL80211_ATTR_DISABLE_HT]))
> +		connect.flags |= ASSOC_REQ_DISABLE_HT;
> +
> +	if (info->attrs[NL80211_ATTR_HT_CAPABILITY_MASK])
> +		memcpy(&connect.ht_capa_mask,
> +		       nla_data(info->attrs[NL80211_ATTR_HT_CAPABILITY_MASK]),
> +		       sizeof(connect.ht_capa_mask));
> +
> +	if (info->attrs[NL80211_ATTR_HT_CAPABILITY]) {
> +		if (!info->attrs[NL80211_ATTR_HT_CAPABILITY_MASK])
> +			return -EINVAL;
> +		memcpy(&connect.ht_capa,
> +		       nla_data(info->attrs[NL80211_ATTR_HT_CAPABILITY]),
> +		       sizeof(connect.ht_capa));
> +	}
> +
>  	err = cfg80211_connect(rdev, dev, &connect, connkeys);
>  	if (err)
>  		kfree(connkeys);
> diff --git a/net/wireless/sme.c b/net/wireless/sme.c
> index 6e86d5a..ed9d0e6 100644
> --- a/net/wireless/sme.c
> +++ b/net/wireless/sme.c
> @@ -189,7 +189,9 @@ static int cfg80211_conn_do_work(struct wireless_dev *wdev)
>  					    prev_bssid,
>  					    params->ssid, params->ssid_len,
>  					    params->ie, params->ie_len,
> -					    false, &params->crypto);
> +					    false, &params->crypto,
> +					    params->flags, &params->ht_capa,
> +					    &params->ht_capa_mask);
>  		if (err)
>  			__cfg80211_mlme_deauth(rdev, wdev->netdev, params->bssid,
>  					       NULL, 0,
> @@ -773,6 +775,9 @@ int __cfg80211_connect(struct cfg80211_registered_device *rdev,
>  		wdev->connect_keys = NULL;
>  	}
>  
> +	cfg80211_oper_and_ht_capa(&connect->ht_capa_mask,
> +				  rdev->wiphy.ht_capa_mod_mask);
> +
>  	if (connkeys && connkeys->def >= 0) {
>  		int idx;
>  		u32 cipher;