[PATCH 9/9] WNM: Keep BTM information until connection completes

Berg, Benjamin benjamin.berg at intel.com
Fri Feb 9 08:47:48 PST 2024


Hi,

On Fri, 2024-02-09 at 16:18 +0100, benjamin at sipsolutions.net wrote:
> From: Benjamin Berg <benjamin.berg at intel.com>
> 
> In the MLD case, the information from the transition management request
> is relevant during the association process in order to filter out links
> that were disallowed by the BTM request. Also, the information remains
> useful should a connection attempt fail.
> 
> To enable these scenarios, keep the information around until the
> connection has completed. As this might make it impossible to establish
> a connection, also clear this information at the same time that a normal
> BSS ignore is cleared to avoid getting stuck in case the transition
> fails unexpectedly.

I am now realizing that the state is not self-contained enough right
now as wnm_is_bss_excluded is using current_bss. So other changes will
be needed before making such a switch.

That said, I do think that the patch is reasonable in principle.

Benjamin

> 
> Signed-off-by: Benjamin Berg <benjamin.berg at intel.com>
> ---
>  wpa_supplicant/ctrl_iface.c       |  2 ++
>  wpa_supplicant/events.c           |  4 ++-
>  wpa_supplicant/wnm_sta.c          | 42 +++++++++++++++--------------
> --
>  wpa_supplicant/wnm_sta.h          | 16 +++++++++++-
>  wpa_supplicant/wpa_supplicant.c   |  8 +++---
>  wpa_supplicant/wpa_supplicant_i.h |  1 -
>  6 files changed, 45 insertions(+), 28 deletions(-)
> 
> diff --git a/wpa_supplicant/ctrl_iface.c
> b/wpa_supplicant/ctrl_iface.c
> index bfc9a6631..4df7e77b4 100644
> --- a/wpa_supplicant/ctrl_iface.c
> +++ b/wpa_supplicant/ctrl_iface.c
> @@ -8839,6 +8839,8 @@ static void
> wpa_supplicant_ctrl_iface_flush(struct wpa_supplicant *wpa_s)
>  
>  	wpa_s->next_ssid = NULL;
>  
> +	wnm_btm_reset(wpa_s);
> +
>  #ifdef CONFIG_INTERWORKING
>  #ifdef CONFIG_HS20
>  	hs20_cancel_fetch_osu(wpa_s);
> diff --git a/wpa_supplicant/events.c b/wpa_supplicant/events.c
> index a938bce99..d4f2609d8 100644
> --- a/wpa_supplicant/events.c
> +++ b/wpa_supplicant/events.c
> @@ -1802,10 +1802,12 @@ struct wpa_bss *
> wpa_supplicant_pick_network(struct wpa_supplicant *wpa_s,
>  				break;
>  		}
>  
> -		if (selected == NULL && wpa_s->bssid_ignore &&
> +		if (selected == NULL &&
> +		    (wpa_s->bssid_ignore ||
> wnm_active_bss_trans_mgmt(wpa_s)) &&
>  		    !wpa_s->countermeasures) {
>  			wpa_dbg(wpa_s, MSG_DEBUG,
>  				"No APs found - clear BSSID ignore
> list and try again");
> +			wnm_btm_reset(wpa_s);
>  			wpa_bssid_ignore_clear(wpa_s);
>  			wpa_s->bssid_ignore_cleared = true;
>  		} else if (selected == NULL)
> diff --git a/wpa_supplicant/wnm_sta.c b/wpa_supplicant/wnm_sta.c
> index 939c3b7c0..c0ed37292 100644
> --- a/wpa_supplicant/wnm_sta.c
> +++ b/wpa_supplicant/wnm_sta.c
> @@ -418,7 +418,7 @@ static void ieee802_11_rx_wnmsleep_resp(struct
> wpa_supplicant *wpa_s,
>  }
>  
>  
> -void wnm_deallocate_memory(struct wpa_supplicant *wpa_s)
> +void wnm_btm_reset(struct wpa_supplicant *wpa_s)
>  {
>  	int i;
>  
> @@ -430,6 +430,18 @@ void wnm_deallocate_memory(struct wpa_supplicant
> *wpa_s)
>  	wpa_s->wnm_num_neighbor_report = 0;
>  	os_free(wpa_s->wnm_neighbor_report_elements);
>  	wpa_s->wnm_neighbor_report_elements = NULL;
> +
> +	wpa_s->wnm_cand_valid_until.sec = 0;
> +	wpa_s->wnm_cand_valid_until.usec = 0;
> +
> +	wpa_s->wnm_mode = 0;
> +	wpa_s->wnm_dialog_token = 0;
> +	wpa_s->wnm_reply = 0;
> +
> +#ifdef CONFIG_MBO
> +	wpa_s->wnm_mbo_trans_reason_present = 0;
> +	wpa_s->wnm_mbo_transition_reason = 0;
> +#endif /* CONFIG_MBO */
>  }
>  
>  
> @@ -1137,7 +1149,6 @@ static void wnm_bss_tm_connect(struct
> wpa_supplicant *wpa_s,
>  	if (bss == wpa_s->current_bss) {
>  		wpa_printf(MSG_DEBUG,
>  			   "WNM: Already associated with the
> preferred candidate");
> -		wnm_deallocate_memory(wpa_s);
>  		return;
>  	}
>  
> @@ -1153,7 +1164,6 @@ static void wnm_bss_tm_connect(struct
> wpa_supplicant *wpa_s,
>  	 */
>  	if (!already_connecting && radio_work_pending(wpa_s, "sme-
> connect"))
>  		wpa_s->bss_trans_mgmt_in_progress = true;
> -	wnm_deallocate_memory(wpa_s);
>  }
>  
>  
> @@ -1165,23 +1175,16 @@ int wnm_scan_process(struct wpa_supplicant
> *wpa_s, int reply_on_fail)
>  	enum mbo_transition_reject_reason reason =
>  		MBO_TRANSITION_REJECT_REASON_UNSPECIFIED;
>  
> -	if (!wpa_s->wnm_neighbor_report_elements)
> +	if (!wpa_s->wnm_dialog_token)
>  		return 0;
>  
>  	wpa_dbg(wpa_s, MSG_DEBUG,
>  		"WNM: Process scan results for BSS Transition
> Management");
> -	if (os_reltime_before(&wpa_s->wnm_cand_valid_until,
> +	if (os_reltime_initialized(&wpa_s->wnm_cand_valid_until) &&
> +	    os_reltime_before(&wpa_s->wnm_cand_valid_until,
>  			      &wpa_s->scan_trigger_time)) {
>  		wpa_printf(MSG_DEBUG, "WNM: Previously stored BSS
> transition candidate list is not valid anymore - drop it");
> -		wnm_deallocate_memory(wpa_s);
> -		return 0;
> -	}
> -
> -	if (!wpa_s->current_bss ||
> -	    !ether_addr_equal(wpa_s->wnm_cand_from_bss,
> -			      wpa_s->current_bss->bssid)) {
> -		wpa_printf(MSG_DEBUG, "WNM: Stored BSS transition
> candidate list not from the current BSS - ignore it");
> -		return 0;
> +		goto send_bss_resp_fail;
>  	}
>  
>  	/* Compare the Neighbor Report and scan results */
> @@ -1208,7 +1211,7 @@ send_bss_resp_fail:
>  						  wpa_s-
> >wnm_dialog_token,
>  						  status, reason, 0,
> NULL);
>  	}
> -	wnm_deallocate_memory(wpa_s);
> +	wnm_btm_reset(wpa_s);
>  
>  	return 0;
>  }
> @@ -1429,16 +1432,13 @@ static void
> ieee802_11_rx_bss_trans_mgmt_req(struct wpa_supplicant *wpa_s,
>  	if (end - pos < 5)
>  		return;
>  
> -#ifdef CONFIG_MBO
> -	wpa_s->wnm_mbo_trans_reason_present = 0;
> -	wpa_s->wnm_mbo_transition_reason = 0;
> -#endif /* CONFIG_MBO */
> -
>  	if (wpa_s->current_bss)
>  		beacon_int = wpa_s->current_bss->beacon_int;
>  	else
>  		beacon_int = 100; /* best guess */
>  
> +	wnm_btm_reset(wpa_s);
> +
>  	wpa_s->wnm_dialog_token = pos[0];
>  	wpa_s->wnm_mode = pos[1];
>  	wpa_s->wnm_dissoc_timer = WPA_GET_LE16(pos + 2);
> @@ -1539,7 +1539,6 @@ static void
> ieee802_11_rx_bss_trans_mgmt_req(struct wpa_supplicant *wpa_s,
>  		unsigned int valid_ms;
>  
>  		wpa_msg(wpa_s, MSG_INFO, "WNM: Preferred List
> Available");
> -		wnm_deallocate_memory(wpa_s);
>  		wpa_s->wnm_neighbor_report_elements = os_calloc(
>  			WNM_MAX_NEIGHBOR_REPORT,
>  			sizeof(struct neighbor_report));
> @@ -1616,7 +1615,6 @@ static void
> ieee802_11_rx_bss_trans_mgmt_req(struct wpa_supplicant *wpa_s,
>  		wpa_s->wnm_cand_valid_until.sec +=
>  			wpa_s->wnm_cand_valid_until.usec / 1000000;
>  		wpa_s->wnm_cand_valid_until.usec %= 1000000;
> -		os_memcpy(wpa_s->wnm_cand_from_bss, wpa_s->bssid,
> ETH_ALEN);
>  
>  		/*
>  		 * Fetch the latest scan results from the kernel and
> check for
> diff --git a/wpa_supplicant/wnm_sta.h b/wpa_supplicant/wnm_sta.h
> index 514a92d70..ba1ae1731 100644
> --- a/wpa_supplicant/wnm_sta.h
> +++ b/wpa_supplicant/wnm_sta.h
> @@ -65,7 +65,7 @@ int wnm_send_bss_transition_mgmt_query(struct
> wpa_supplicant *wpa_s,
>  				       const char *btm_candidates,
>  				       int cand_list);
>  
> -void wnm_deallocate_memory(struct wpa_supplicant *wpa_s);
> +void wnm_btm_reset(struct wpa_supplicant *wpa_s);
>  int wnm_send_coloc_intf_report(struct wpa_supplicant *wpa_s, u8
> dialog_token,
>  			       const struct wpabuf *elems);
>  void wnm_set_coloc_intf_elems(struct wpa_supplicant *wpa_s,
> @@ -81,6 +81,11 @@ void wnm_clear_coloc_intf_reporting(struct
> wpa_supplicant *wpa_s);
>  
>  bool wnm_is_bss_excluded(struct wpa_supplicant *wpa_s, struct
> wpa_bss *bss);
>  
> +static inline bool wnm_active_bss_trans_mgmt(struct wpa_supplicant
> *wpa_s)
> +{
> +	return !!wpa_s->wnm_dialog_token;
> +}
> +
>  #else /* CONFIG_WNM */
>  
>  static inline int wnm_scan_process(struct wpa_supplicant *wpa_s,
> @@ -99,6 +104,15 @@ wnm_is_bss_excluded(struct wpa_supplicant *wpa_s,
> struct wpa_bss *bss)
>  	return false;
>  }
>  
> +static inline wnm_btm_reset(struct wpa_supplicant *wpa_s)
> +{
> +}
> +
> +static inline bool wnm_active_bss_trans_mgmt(struct wpa_supplicant
> *wpa_s)
> +{
> +	return false;
> +}
> +
>  #endif /* CONFIG_WNM */
>  
>  #endif /* WNM_STA_H */
> diff --git a/wpa_supplicant/wpa_supplicant.c
> b/wpa_supplicant/wpa_supplicant.c
> index afe827e01..0bd19e1bb 100644
> --- a/wpa_supplicant/wpa_supplicant.c
> +++ b/wpa_supplicant/wpa_supplicant.c
> @@ -675,9 +675,7 @@ static void wpa_supplicant_cleanup(struct
> wpa_supplicant *wpa_s)
>  	wpa_s->disallow_aps_ssid = NULL;
>  
>  	wnm_bss_keep_alive_deinit(wpa_s);
> -#ifdef CONFIG_WNM
> -	wnm_deallocate_memory(wpa_s);
> -#endif /* CONFIG_WNM */
> +	wnm_btm_reset(wpa_s);
>  
>  	ext_password_deinit(wpa_s->ext_pw);
>  	wpa_s->ext_pw = NULL;
> @@ -1071,6 +1069,10 @@ void wpa_supplicant_set_state(struct
> wpa_supplicant *wpa_s,
>  	if (state == WPA_DISCONNECTED || state == WPA_INACTIVE)
>  		wpa_supplicant_start_autoscan(wpa_s);
>  
> +	if (state == WPA_COMPLETED || state ==
> WPA_INTERFACE_DISABLED ||
> +	    state == WPA_INACTIVE)
> +		wnm_btm_reset(wpa_s);
> +
>  #ifndef CONFIG_NO_WMM_AC
>  	if (old_state >= WPA_ASSOCIATED && wpa_s->wpa_state <
> WPA_ASSOCIATED)
>  		wmm_ac_notify_disassoc(wpa_s);
> diff --git a/wpa_supplicant/wpa_supplicant_i.h
> b/wpa_supplicant/wpa_supplicant_i.h
> index 7d72b56ff..77df97842 100644
> --- a/wpa_supplicant/wpa_supplicant_i.h
> +++ b/wpa_supplicant/wpa_supplicant_i.h
> @@ -1308,7 +1308,6 @@ struct wpa_supplicant {
>  	u8 wnm_bss_termination_duration[12];
>  	struct neighbor_report *wnm_neighbor_report_elements;
>  	struct os_reltime wnm_cand_valid_until;
> -	u8 wnm_cand_from_bss[ETH_ALEN];
>  	struct wpa_bss *wnm_target_bss;
>  	enum bss_trans_mgmt_status_code bss_tm_status;
>  	bool bss_trans_mgmt_in_progress;

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