Re: [PATCH v14 mac80211-next 1/3] mac80211: MBSSID beacon handling in AP mode

[Hsin-An Wang <money.wang@mediatek.com>]

On Thu, 2022-02-24 at 12:54 +0100, Lorenzo Bianconi wrote:
> Add new fields in struct beacon_data to store all MBSSID elements.
> Generate a beacon template which includes all MBSSID elements.
> Move CSA offset to reflect the MBSSID element length.
> 

Tested-by: Money Wang <money.wang@mediatek.com>

> Co-developed-by: Aloka Dixit <alokad@codeaurora.org>
> Signed-off-by: Aloka Dixit <alokad@codeaurora.org>
> Co-developed-by: John Crispin <john@phrozen.org>
> Signed-off-by: John Crispin <john@phrozen.org>
> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
> ---
>  include/net/mac80211.h     |  2 +
>  net/mac80211/cfg.c         | 99 +++++++++++++++++++++++++++++++++---
> --
>  net/mac80211/ieee80211_i.h | 15 ++++++
>  net/mac80211/tx.c          | 24 ++++++++-
>  4 files changed, 126 insertions(+), 14 deletions(-)
> 
> diff --git a/include/net/mac80211.h b/include/net/mac80211.h
> index c50221d7e82c..b73913e039c6 100644
> --- a/include/net/mac80211.h
> +++ b/include/net/mac80211.h
> @@ -4931,12 +4931,14 @@ void ieee80211_report_low_ack(struct
> ieee80211_sta *sta, u32 num_packets);
>   * @cntdwn_counter_offs: array of IEEE80211_MAX_CNTDWN_COUNTERS_NUM
> offsets
>   *	to countdown counters.  This array can contain zero values
> which
>   *	should be ignored.
> + * @mbssid_off: position of the multiple bssid element
>   */
>  struct ieee80211_mutable_offsets {
>  	u16 tim_offset;
>  	u16 tim_length;
>  
>  	u16 cntdwn_counter_offs[IEEE80211_MAX_CNTDWN_COUNTERS_NUM];
> +	u16 mbssid_off;
>  };
>  
>  /**
> diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
> index 87a208089caf..f7324a6d4a78 100644
> --- a/net/mac80211/cfg.c
> +++ b/net/mac80211/cfg.c
> @@ -989,11 +989,29 @@ static int ieee80211_set_ftm_responder_params(
>  	return 0;
>  }
>  
> +static int
> +ieee80211_copy_mbssid_beacon(u8 *pos, struct cfg80211_mbssid_elems
> *dst,
> +			     struct cfg80211_mbssid_elems *src)
> +{
> +	int i, offset = 0;
> +
> +	for (i = 0; i < src->cnt; i++) {
> +		memcpy(pos + offset, src->elem[i].data, src-
> >elem[i].len);
> +		dst->elem[i].len = src->elem[i].len;
> +		dst->elem[i].data = pos + offset;
> +		offset += dst->elem[i].len;
> +	}
> +	dst->cnt = src->cnt;
> +
> +	return offset;
> +}
> +
>  static int ieee80211_assign_beacon(struct ieee80211_sub_if_data
> *sdata,
>  				   struct cfg80211_beacon_data *params,
>  				   const struct ieee80211_csa_settings
> *csa,
>  				   const struct
> ieee80211_color_change_settings *cca)
>  {
> +	struct cfg80211_mbssid_elems *mbssid = NULL;
>  	struct beacon_data *new, *old;
>  	int new_head_len, new_tail_len;
>  	int size, err;
> @@ -1019,8 +1037,19 @@ static int ieee80211_assign_beacon(struct
> ieee80211_sub_if_data *sdata,
>  	else
>  		new_tail_len = old->tail_len;
>  
> +	/* new or old multiple BSSID elements? */
>  	size = sizeof(*new) + new_head_len + new_tail_len;
>  
> +	if (params->mbssid_ies) {
> +		mbssid = params->mbssid_ies;
> +		size += struct_size(new->mbssid_ies, elem, mbssid-
> >cnt);
> +		size += ieee80211_get_mbssid_beacon_len(mbssid);
> +	} else if (old && old->mbssid_ies) {
> +		mbssid = old->mbssid_ies;
> +		size += struct_size(new->mbssid_ies, elem, mbssid-
> >cnt);
> +		size += ieee80211_get_mbssid_beacon_len(mbssid);
> +	}
> +
>  	new = kzalloc(size, GFP_KERNEL);
>  	if (!new)
>  		return -ENOMEM;
> @@ -1029,12 +1058,20 @@ static int ieee80211_assign_beacon(struct
> ieee80211_sub_if_data *sdata,
>  
>  	/*
>  	 * pointers go into the block we allocated,
> -	 * memory is | beacon_data | head | tail |
> +	 * memory is | beacon_data | head | tail | mbssid_ies
>  	 */
>  	new->head = ((u8 *) new) + sizeof(*new);
>  	new->tail = new->head + new_head_len;
>  	new->head_len = new_head_len;
>  	new->tail_len = new_tail_len;
> +	/* copy in optional mbssid_ies */
> +	if (mbssid) {
> +		u8 *pos = new->tail + new->tail_len;
> +
> +		new->mbssid_ies = (struct cfg80211_mbssid_elems *)pos;
> +		pos += struct_size(new->mbssid_ies, elem, mbssid->cnt);
> +		ieee80211_copy_mbssid_beacon(pos, new->mbssid_ies,
> mbssid);
> +	}
>  
>  	if (csa) {
>  		new->cntdwn_current_counter = csa->count;
> @@ -1332,8 +1369,11 @@ static int ieee80211_stop_ap(struct wiphy
> *wiphy, struct net_device *dev)
>  
>  	mutex_unlock(&local->mtx);
>  
> -	kfree(sdata->u.ap.next_beacon);
> -	sdata->u.ap.next_beacon = NULL;
> +	if (sdata->u.ap.next_beacon) {
> +		kfree(sdata->u.ap.next_beacon->mbssid_ies);
> +		kfree(sdata->u.ap.next_beacon);
> +		sdata->u.ap.next_beacon = NULL;
> +	}
>  
>  	/* turn off carrier for this interface and dependent VLANs */
>  	list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
> @@ -3130,12 +3170,24 @@ cfg80211_beacon_dup(struct
> cfg80211_beacon_data *beacon)
>  
>  	len = beacon->head_len + beacon->tail_len + beacon-
> >beacon_ies_len +
>  	      beacon->proberesp_ies_len + beacon->assocresp_ies_len +
> -	      beacon->probe_resp_len + beacon->lci_len + beacon-
> >civicloc_len;
> +	      beacon->probe_resp_len + beacon->lci_len + beacon-
> >civicloc_len +
> +	      ieee80211_get_mbssid_beacon_len(beacon->mbssid_ies);
>  
>  	new_beacon = kzalloc(sizeof(*new_beacon) + len, GFP_KERNEL);
>  	if (!new_beacon)
>  		return NULL;
>  
> +	if (beacon->mbssid_ies && beacon->mbssid_ies->cnt) {
> +		new_beacon->mbssid_ies =
> +			kzalloc(struct_size(new_beacon->mbssid_ies,
> +					    elem, beacon->mbssid_ies-
> >cnt),
> +				GFP_KERNEL);
> +		if (!new_beacon->mbssid_ies) {
> +			kfree(new_beacon);
> +			return NULL;
> +		}
> +	}
> +
>  	pos = (u8 *)(new_beacon + 1);
>  	if (beacon->head_len) {
>  		new_beacon->head_len = beacon->head_len;
> @@ -3173,6 +3225,10 @@ cfg80211_beacon_dup(struct
> cfg80211_beacon_data *beacon)
>  		memcpy(pos, beacon->probe_resp, beacon-
> >probe_resp_len);
>  		pos += beacon->probe_resp_len;
>  	}
> +	if (beacon->mbssid_ies && beacon->mbssid_ies->cnt)
> +		pos += ieee80211_copy_mbssid_beacon(pos,
> +						    new_beacon-
> >mbssid_ies,
> +						    beacon-
> >mbssid_ies);
>  
>  	/* might copy -1, meaning no changes requested */
>  	new_beacon->ftm_responder = beacon->ftm_responder;
> @@ -3222,8 +3278,11 @@ static int
> ieee80211_set_after_csa_beacon(struct ieee80211_sub_if_data *sdata,
>  	case NL80211_IFTYPE_AP:
>  		err = ieee80211_assign_beacon(sdata, sdata-
> >u.ap.next_beacon,
>  					      NULL, NULL);
> -		kfree(sdata->u.ap.next_beacon);
> -		sdata->u.ap.next_beacon = NULL;
> +		if (sdata->u.ap.next_beacon) {
> +			kfree(sdata->u.ap.next_beacon->mbssid_ies);
> +			kfree(sdata->u.ap.next_beacon);
> +			sdata->u.ap.next_beacon = NULL;
> +		}
>  
>  		if (err < 0)
>  			return err;
> @@ -3378,8 +3437,12 @@ static int ieee80211_set_csa_beacon(struct
> ieee80211_sub_if_data *sdata,
>  		if ((params->n_counter_offsets_beacon >
>  		     IEEE80211_MAX_CNTDWN_COUNTERS_NUM) ||
>  		    (params->n_counter_offsets_presp >
> -		     IEEE80211_MAX_CNTDWN_COUNTERS_NUM))
> +		     IEEE80211_MAX_CNTDWN_COUNTERS_NUM)) {
> +			kfree(sdata->u.ap.next_beacon->mbssid_ies);
> +			kfree(sdata->u.ap.next_beacon);
> +			sdata->u.ap.next_beacon = NULL;
>  			return -EINVAL;
> +		}
>  
>  		csa.counter_offsets_beacon = params-
> >counter_offsets_beacon;
>  		csa.counter_offsets_presp = params-
> >counter_offsets_presp;
> @@ -3389,7 +3452,9 @@ static int ieee80211_set_csa_beacon(struct
> ieee80211_sub_if_data *sdata,
>  
>  		err = ieee80211_assign_beacon(sdata, &params-
> >beacon_csa, &csa, NULL);
>  		if (err < 0) {
> +			kfree(sdata->u.ap.next_beacon->mbssid_ies);
>  			kfree(sdata->u.ap.next_beacon);
> +			sdata->u.ap.next_beacon = NULL;
>  			return err;
>  		}
>  		*changed |= err;
> @@ -3479,8 +3544,11 @@ static int ieee80211_set_csa_beacon(struct
> ieee80211_sub_if_data *sdata,
>  static void ieee80211_color_change_abort(struct
> ieee80211_sub_if_data  *sdata)
>  {
>  	sdata->vif.color_change_active = false;
> -	kfree(sdata->u.ap.next_beacon);
> -	sdata->u.ap.next_beacon = NULL;
> +	if (sdata->u.ap.next_beacon) {
> +		kfree(sdata->u.ap.next_beacon->mbssid_ies);
> +		kfree(sdata->u.ap.next_beacon);
> +		sdata->u.ap.next_beacon = NULL;
> +	}
>  
>  	cfg80211_color_change_aborted_notify(sdata->dev);
>  }
> @@ -4218,8 +4286,11 @@ ieee80211_set_after_color_change_beacon(struct
> ieee80211_sub_if_data *sdata,
>  
>  		ret = ieee80211_assign_beacon(sdata, sdata-
> >u.ap.next_beacon,
>  					      NULL, NULL);
> -		kfree(sdata->u.ap.next_beacon);
> -		sdata->u.ap.next_beacon = NULL;
> +		if (sdata->u.ap.next_beacon) {
> +			kfree(sdata->u.ap.next_beacon->mbssid_ies);
> +			kfree(sdata->u.ap.next_beacon);
> +			sdata->u.ap.next_beacon = NULL;
> +		}
>  
>  		if (ret < 0)
>  			return ret;
> @@ -4262,7 +4333,11 @@ ieee80211_set_color_change_beacon(struct
> ieee80211_sub_if_data *sdata,
>  		err = ieee80211_assign_beacon(sdata, &params-
> >beacon_color_change,
>  					      NULL, &color_change);
>  		if (err < 0) {
> -			kfree(sdata->u.ap.next_beacon);
> +			if (sdata->u.ap.next_beacon) {
> +				kfree(sdata->u.ap.next_beacon-
> >mbssid_ies);
> +				kfree(sdata->u.ap.next_beacon);
> +				sdata->u.ap.next_beacon = NULL;
> +			}
>  			return err;
>  		}
>  		*changed |= err;
> diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
> index 330ea62231fa..34484b3bc307 100644
> --- a/net/mac80211/ieee80211_i.h
> +++ b/net/mac80211/ieee80211_i.h
> @@ -257,6 +257,7 @@ struct beacon_data {
>  	struct ieee80211_meshconf_ie *meshconf;
>  	u16 cntdwn_counter_offsets[IEEE80211_MAX_CNTDWN_COUNTERS_NUM];
>  	u8 cntdwn_current_counter;
> +	struct cfg80211_mbssid_elems *mbssid_ies;
>  	struct rcu_head rcu_head;
>  };
>  
> @@ -1078,6 +1079,20 @@ ieee80211_vif_get_shift(struct ieee80211_vif
> *vif)
>  	return shift;
>  }
>  
> +static inline int
> +ieee80211_get_mbssid_beacon_len(struct cfg80211_mbssid_elems *elems)
> +{
> +	int i, len = 0;
> +
> +	if (!elems)
> +		return 0;
> +
> +	for (i = 0; i < elems->cnt; i++)
> +		len += elems->elem[i].len;
> +
> +	return len;
> +}
> +
>  enum {
>  	IEEE80211_RX_MSG	= 1,
>  	IEEE80211_TX_STATUS_MSG	= 2,
> diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
> index 6d054fed062f..b6b20f38de0e 100644
> --- a/net/mac80211/tx.c
> +++ b/net/mac80211/tx.c
> @@ -5042,6 +5042,19 @@ ieee80211_beacon_get_finish(struct
> ieee80211_hw *hw,
>  		       IEEE80211_TX_CTL_FIRST_FRAGMENT;
>  }
>  
> +static void
> +ieee80211_beacon_add_mbssid(struct sk_buff *skb, struct beacon_data
> *beacon)
> +{
> +	int i;
> +
> +	if (!beacon->mbssid_ies)
> +		return;
> +
> +	for (i = 0; i < beacon->mbssid_ies->cnt; i++)
> +		skb_put_data(skb, beacon->mbssid_ies->elem[i].data,
> +			     beacon->mbssid_ies->elem[i].len);
> +}
> +
>  static struct sk_buff *
>  ieee80211_beacon_get_ap(struct ieee80211_hw *hw,
>  			struct ieee80211_vif *vif,
> @@ -5055,6 +5068,7 @@ ieee80211_beacon_get_ap(struct ieee80211_hw
> *hw,
>  	struct ieee80211_if_ap *ap = &sdata->u.ap;
>  	struct sk_buff *skb = NULL;
>  	u16 csa_off_base = 0;
> +	int mbssid_len;
>  
>  	if (beacon->cntdwn_counter_offsets[0]) {
>  		if (!is_template)
> @@ -5064,11 +5078,12 @@ ieee80211_beacon_get_ap(struct ieee80211_hw
> *hw,
>  	}
>  
>  	/* headroom, head length,
> -	 * tail length and maximum TIM length
> +	 * tail length, maximum TIM length and multiple BSSID length
>  	 */
> +	mbssid_len = ieee80211_get_mbssid_beacon_len(beacon-
> >mbssid_ies);
>  	skb = dev_alloc_skb(local->tx_headroom + beacon->head_len +
>  			    beacon->tail_len + 256 +
> -			    local->hw.extra_beacon_tailroom);
> +			    local->hw.extra_beacon_tailroom +
> mbssid_len);
>  	if (!skb)
>  		return NULL;
>  
> @@ -5082,6 +5097,11 @@ ieee80211_beacon_get_ap(struct ieee80211_hw
> *hw,
>  		offs->tim_length = skb->len - beacon->head_len;
>  		offs->cntdwn_counter_offs[0] = beacon-
> >cntdwn_counter_offsets[0];
>  
> +		if (mbssid_len) {
> +			ieee80211_beacon_add_mbssid(skb, beacon);
> +			offs->mbssid_off = skb->len - mbssid_len;
> +		}
> +
>  		/* for AP the csa offsets are from tail */
>  		csa_off_base = skb->len;
>  	}