diff mbox

[PATCHv2,1/3] mac80211: move mesh sync beacon handler into neighbour_update

Message ID 1361203709-16669-1-git-send-email-marco@cozybit.com (mailing list archive)
State Not Applicable, archived
Headers show

Commit Message

Marco Porsch Feb. 18, 2013, 4:08 p.m. UTC 
Move the beacon handler into mesh_neighbour_update where the STA
pointer is already available. This avoids additional overhead
and simplifies the handler.
The repositioning will also benefit mesh PS which uses T_r and
the updated T_offset value.

Rename the handler to better reflect its purpose.

Signed-off-by: Marco Porsch <marco@cozybit.com>
---

v2:
calculate T_r outside mesh sync handler (Johannes)
remove unused variables

 net/mac80211/ieee80211_i.h |    9 ++++-----
 net/mac80211/mesh.c        |    7 +------
 net/mac80211/mesh.h        |    4 +++-
 net/mac80211/mesh_plink.c  |   31 +++++++++++++++++++++++++-----
 net/mac80211/mesh_sync.c   |   45 ++++++++++----------------------------------
 5 files changed, 44 insertions(+), 52 deletions(-)

Comments

Johannes Berg Feb. 20, 2013, 2:50 p.m. UTC | #1 
On Mon, 2013-02-18 at 17:08 +0100, Marco Porsch wrote:

> +	/*
> +	 * If available, calculate the time the beacon timestamp field was
> +	 * received from the rx_status->mactime field. Otherwise get the
> +	 * current TSF as approximation before entering rcu-read section.
> +	 */
> +	if (ieee80211_have_rx_timestamp(rx_status))
> +		t_r = ieee80211_calculate_rx_timestamp(local, rx_status,
> +						       24 + 12 +
> +						       elems->total_len +
> +						       FCS_LEN,
> +						       24);

That doesn't seem right -- it's calculating the timestamp at the end of
the frame, but you said you wanted the timestamp at the "timestamp
field" time, which is just 24 bytes into the frame.

> +static void mesh_sync_offset_rx_bcn(struct sta_info *sta,
> +				    struct ieee80211_mgmt *mgmt,
> +				    struct ieee802_11_elems *elems,
> +				    u64 t_r)
>  {
> +	struct ieee80211_sub_if_data *sdata = sta->sdata;
>  	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
> -	struct ieee80211_local *local = sdata->local;
> -	struct sta_info *sta;
> -	u64 t_t, t_r;
> +	u64 t_t;
>  
>  	WARN_ON(ifmsh->mesh_sp_id != IEEE80211_SYNC_METHOD_NEIGHBOR_OFFSET);
>  
>  	/* standard mentions only beacons */
> -	if (stype != IEEE80211_STYPE_BEACON)
> +	if (!ieee80211_is_beacon(mgmt->frame_control))
>  		return;

This is a bit odd -- why should a function that's called _rx_bcn() have
to check it? Seems the check should be outside the API boundary.
 

> -	if (ieee80211_have_rx_timestamp(rx_status))
> -		/* time when timestamp field was received */
> -		t_r = ieee80211_calculate_rx_timestamp(local, rx_status,
> -						       24 + 12 +
> -						       elems->total_len +
> -						       FCS_LEN,
> -						       24);

I see this was already wrong ...

johannes

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Thomas Pedersen Feb. 20, 2013, 6:26 p.m. UTC | #2 
On Wed, Feb 20, 2013 at 6:50 AM, Johannes Berg
<johannes@sipsolutions.net> wrote:
> On Mon, 2013-02-18 at 17:08 +0100, Marco Porsch wrote:
>
>> +     /*
>> +      * If available, calculate the time the beacon timestamp field was
>> +      * received from the rx_status->mactime field. Otherwise get the
>> +      * current TSF as approximation before entering rcu-read section.
>> +      */
>> +     if (ieee80211_have_rx_timestamp(rx_status))
>> +             t_r = ieee80211_calculate_rx_timestamp(local, rx_status,
>> +                                                    24 + 12 +
>> +                                                    elems->total_len +
>> +                                                    FCS_LEN,
>> +                                                    24);
>
> That doesn't seem right -- it's calculating the timestamp at the end of
> the frame, but you said you wanted the timestamp at the "timestamp
> field" time, which is just 24 bytes into the frame.

[...]

>> -     if (ieee80211_have_rx_timestamp(rx_status))
>> -             /* time when timestamp field was received */
>> -             t_r = ieee80211_calculate_rx_timestamp(local, rx_status,
>> -                                                    24 + 12 +
>> -                                                    elems->total_len +
>> -                                                    FCS_LEN,
>> -                                                    24);
>
> I see this was already wrong ...

No it's OK. The API is actually
ieee80211_calculate_rx_timestamp(local, status, len, offset).
Johannes Berg Feb. 20, 2013, 8 p.m. UTC | #3 
On Wed, 2013-02-20 at 10:26 -0800, Thomas Pedersen wrote:
> On Wed, Feb 20, 2013 at 6:50 AM, Johannes Berg
> <johannes@sipsolutions.net> wrote:
> > On Mon, 2013-02-18 at 17:08 +0100, Marco Porsch wrote:
> >
> >> +     /*
> >> +      * If available, calculate the time the beacon timestamp field was
> >> +      * received from the rx_status->mactime field. Otherwise get the
> >> +      * current TSF as approximation before entering rcu-read section.
> >> +      */
> >> +     if (ieee80211_have_rx_timestamp(rx_status))
> >> +             t_r = ieee80211_calculate_rx_timestamp(local, rx_status,
> >> +                                                    24 + 12 +
> >> +                                                    elems->total_len +
> >> +                                                    FCS_LEN,
> >> +                                                    24);
> >
> > That doesn't seem right -- it's calculating the timestamp at the end of
> > the frame, but you said you wanted the timestamp at the "timestamp
> > field" time, which is just 24 bytes into the frame.
> 
> [...]
> 
> >> -     if (ieee80211_have_rx_timestamp(rx_status))
> >> -             /* time when timestamp field was received */
> >> -             t_r = ieee80211_calculate_rx_timestamp(local, rx_status,
> >> -                                                    24 + 12 +
> >> -                                                    elems->total_len +
> >> -                                                    FCS_LEN,
> >> -                                                    24);
> >
> > I see this was already wrong ...
> 
> No it's OK. The API is actually
> ieee80211_calculate_rx_timestamp(local, status, len, offset).

Oops, indeed, my mistake.

johannes

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diff mbox

Patch

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 388580a..631760f 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -529,11 +529,10 @@  struct ieee80211_if_ibss {
  */
 struct ieee802_11_elems;
 struct ieee80211_mesh_sync_ops {
-	void (*rx_bcn_presp)(struct ieee80211_sub_if_data *sdata,
-			     u16 stype,
-			     struct ieee80211_mgmt *mgmt,
-			     struct ieee802_11_elems *elems,
-			     struct ieee80211_rx_status *rx_status);
+	void (*rx_bcn)(struct sta_info *sta,
+		       struct ieee80211_mgmt *mgmt,
+		       struct ieee802_11_elems *elems,
+		       u64 t_r);
 	void (*adjust_tbtt)(struct ieee80211_sub_if_data *sdata);
 	/* add other framework functions here */
 };
diff --git a/net/mac80211/mesh.c b/net/mac80211/mesh.c
index 29ce2aa..94682d2 100644
--- a/net/mac80211/mesh.c
+++ b/net/mac80211/mesh.c
@@ -938,7 +938,6 @@  static void ieee80211_mesh_rx_bcn_presp(struct ieee80211_sub_if_data *sdata,
 					struct ieee80211_rx_status *rx_status)
 {
 	struct ieee80211_local *local = sdata->local;
-	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
 	struct ieee802_11_elems elems;
 	struct ieee80211_channel *channel;
 	size_t baselen;
@@ -974,11 +973,7 @@  static void ieee80211_mesh_rx_bcn_presp(struct ieee80211_sub_if_data *sdata,
 		return;
 
 	if (mesh_matches_local(sdata, &elems))
-		mesh_neighbour_update(sdata, mgmt->sa, &elems);
-
-	if (ifmsh->sync_ops)
-		ifmsh->sync_ops->rx_bcn_presp(sdata,
-			stype, mgmt, &elems, rx_status);
+		mesh_neighbour_update(sdata, mgmt, &elems, rx_status);
 }
 
 static void ieee80211_mesh_rx_mgmt_action(struct ieee80211_sub_if_data *sdata,
diff --git a/net/mac80211/mesh.h b/net/mac80211/mesh.h
index 336c88a..ac02f38 100644
--- a/net/mac80211/mesh.h
+++ b/net/mac80211/mesh.h
@@ -283,7 +283,9 @@  int mesh_gate_num(struct ieee80211_sub_if_data *sdata);
 
 /* Mesh plinks */
 void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata,
-			   u8 *hw_addr, struct ieee802_11_elems *ie);
+			   struct ieee80211_mgmt *mgmt,
+			   struct ieee802_11_elems *ie,
+			   struct ieee80211_rx_status *rx_status);
 bool mesh_peer_accepts_plinks(struct ieee802_11_elems *ie);
 u32 mesh_accept_plinks_update(struct ieee80211_sub_if_data *sdata);
 void mesh_plink_broken(struct sta_info *sta);
diff --git a/net/mac80211/mesh_plink.c b/net/mac80211/mesh_plink.c
index 07d396d..d40fedd 100644
--- a/net/mac80211/mesh_plink.c
+++ b/net/mac80211/mesh_plink.c
@@ -12,6 +12,7 @@ 
 #include "ieee80211_i.h"
 #include "rate.h"
 #include "mesh.h"
+#include "driver-ops.h"
 
 #define PLINK_GET_LLID(p) (p + 2)
 #define PLINK_GET_PLID(p) (p + 4)
@@ -497,23 +498,43 @@  mesh_sta_info_get(struct ieee80211_sub_if_data *sdata,
  * Initiates peering if appropriate.
  */
 void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata,
-			   u8 *hw_addr,
-			   struct ieee802_11_elems *elems)
+			   struct ieee80211_mgmt *mgmt,
+			   struct ieee802_11_elems *elems,
+			   struct ieee80211_rx_status *rx_status)
 {
+	struct ieee80211_local *local = sdata->local;
+	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
 	struct sta_info *sta;
 	u32 changed = 0;
+	u64 t_r;
+
+	/*
+	 * If available, calculate the time the beacon timestamp field was
+	 * received from the rx_status->mactime field. Otherwise get the
+	 * current TSF as approximation before entering rcu-read section.
+	 */
+	if (ieee80211_have_rx_timestamp(rx_status))
+		t_r = ieee80211_calculate_rx_timestamp(local, rx_status,
+						       24 + 12 +
+						       elems->total_len +
+						       FCS_LEN,
+						       24);
+	else
+		t_r = drv_get_tsf(local, sdata);
 
-	sta = mesh_sta_info_get(sdata, hw_addr, elems);
+	sta = mesh_sta_info_get(sdata, mgmt->sa, elems);
 	if (!sta)
 		goto out;
 
 	if (mesh_peer_accepts_plinks(elems) &&
 	    sta->plink_state == NL80211_PLINK_LISTEN &&
-	    sdata->u.mesh.accepting_plinks &&
-	    sdata->u.mesh.mshcfg.auto_open_plinks &&
+	    ifmsh->accepting_plinks && ifmsh->mshcfg.auto_open_plinks &&
 	    rssi_threshold_check(sta, sdata))
 		changed = mesh_plink_open(sta);
 
+	if (ifmsh->sync_ops)
+		ifmsh->sync_ops->rx_bcn(sta, mgmt, elems, t_r);
+
 	ieee80211_mps_frame_release(sta, elems);
 out:
 	rcu_read_unlock();
diff --git a/net/mac80211/mesh_sync.c b/net/mac80211/mesh_sync.c
index 05a256b..6170ec2 100644
--- a/net/mac80211/mesh_sync.c
+++ b/net/mac80211/mesh_sync.c
@@ -75,35 +75,21 @@  void mesh_sync_adjust_tbtt(struct ieee80211_sub_if_data *sdata)
 		drv_set_tsf(local, sdata, tsf + tsfdelta);
 }
 
-static void mesh_sync_offset_rx_bcn_presp(struct ieee80211_sub_if_data *sdata,
-				   u16 stype,
-				   struct ieee80211_mgmt *mgmt,
-				   struct ieee802_11_elems *elems,
-				   struct ieee80211_rx_status *rx_status)
+static void mesh_sync_offset_rx_bcn(struct sta_info *sta,
+				    struct ieee80211_mgmt *mgmt,
+				    struct ieee802_11_elems *elems,
+				    u64 t_r)
 {
+	struct ieee80211_sub_if_data *sdata = sta->sdata;
 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
-	struct ieee80211_local *local = sdata->local;
-	struct sta_info *sta;
-	u64 t_t, t_r;
+	u64 t_t;
 
 	WARN_ON(ifmsh->mesh_sp_id != IEEE80211_SYNC_METHOD_NEIGHBOR_OFFSET);
 
 	/* standard mentions only beacons */
-	if (stype != IEEE80211_STYPE_BEACON)
+	if (!ieee80211_is_beacon(mgmt->frame_control))
 		return;
 
-	/* The current tsf is a first approximation for the timestamp
-	 * for the received beacon.  Further down we try to get a
-	 * better value from the rx_status->mactime field if
-	 * available. Also we have to call drv_get_tsf() before
-	 * entering the rcu-read section.*/
-	t_r = drv_get_tsf(local, sdata);
-
-	rcu_read_lock();
-	sta = sta_info_get(sdata, mgmt->sa);
-	if (!sta)
-		goto no_sync;
-
 	/* check offset sync conditions (13.13.2.2.1)
 	 *
 	 * TODO also sync to
@@ -114,17 +100,9 @@  static void mesh_sync_offset_rx_bcn_presp(struct ieee80211_sub_if_data *sdata,
 		clear_sta_flag(sta, WLAN_STA_TOFFSET_KNOWN);
 		msync_dbg(sdata, "STA %pM : is adjusting TBTT\n",
 			  sta->sta.addr);
-		goto no_sync;
+		return;
 	}
 
-	if (ieee80211_have_rx_timestamp(rx_status))
-		/* time when timestamp field was received */
-		t_r = ieee80211_calculate_rx_timestamp(local, rx_status,
-						       24 + 12 +
-						       elems->total_len +
-						       FCS_LEN,
-						       24);
-
 	/* Timing offset calculation (see 13.13.2.2.2) */
 	t_t = le64_to_cpu(mgmt->u.beacon.timestamp);
 	sta->t_offset = t_t - t_r;
@@ -144,7 +122,7 @@  static void mesh_sync_offset_rx_bcn_presp(struct ieee80211_sub_if_data *sdata,
 				  sta->sta.addr,
 				  (long long) t_clockdrift);
 			clear_sta_flag(sta, WLAN_STA_TOFFSET_KNOWN);
-			goto no_sync;
+			return;
 		}
 
 		spin_lock_bh(&ifmsh->sync_offset_lock);
@@ -159,9 +137,6 @@  static void mesh_sync_offset_rx_bcn_presp(struct ieee80211_sub_if_data *sdata,
 			  sta->sta.addr,
 			  (long long) sta->t_offset);
 	}
-
-no_sync:
-	rcu_read_unlock();
 }
 
 static void mesh_sync_offset_adjust_tbtt(struct ieee80211_sub_if_data *sdata)
@@ -200,7 +175,7 @@  static const struct sync_method sync_methods[] = {
 	{
 		.method = IEEE80211_SYNC_METHOD_NEIGHBOR_OFFSET,
 		.ops = {
-			.rx_bcn_presp = &mesh_sync_offset_rx_bcn_presp,
+			.rx_bcn = &mesh_sync_offset_rx_bcn,
 			.adjust_tbtt = &mesh_sync_offset_adjust_tbtt,
 		}
 	},