cfg80211: Add channel type for IBSS

PATCH In review Alexander Simon 3 participants 18 messages Apr 12, 2011 – Apr 29, 2011

Subsystems (2)

mac80211 802.11 (including cfg80211/NL80211)

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Alexander Simon

author

2011-04-12 10:42 UTC #0 lore raw

PATCH 1/4 cfg80211: Add channel type for IBSS

Needed for IBSS IEEE802.11N operation

* Add ht channel type for cfg80211 IBSS configuration

Signed-off-by Alexander Simon <[email protected]>

---
 cfg80211.h |    1 +
 1 file changed, 1 insertion(+)

include/net/cfg80211.h +1 -0

diff -Nrup a/include/net/cfg80211.h b/include/net/cfg80211.h
@@ -964,6 +964,7 @@ struct cfg80211_ibss_params {
 	u8 *ssid;
 	u8 *bssid;
 	struct ieee80211_channel *channel;
+	enum nl80211_channel_type channel_type;
 	u8 *ie;
 	u8 ssid_len, ie_len;
 	u16 beacon_interval;

Alexander Simon

author

2011-04-12 11:04 UTC #1 lore raw

Re: [PATCH 2/4] nl80211: Add NL80211_ATTR_WIPHY_CHANNEL_TYPE for IBSS

Needed for IBSS IEEE802.11N operation

* Add a new attribute NL80211_ATTR_WIPHY_CHANNEL_TYPE to specify a HT channel type for IBSS

Signed-off-by Alexander Simon <[email protected]>

---
 nl80211.c |   20 ++++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

net/wireless/nl80211.c +18 -2

diff -Nrup a/net/wireless/nl80211.c b/net/wireless/nl80211.c
@@ -3927,8 +3927,24 @@ static int nl80211_join_ibss(struct sk_b
 		ibss.ie_len = nla_len(info->attrs[NL80211_ATTR_IE]);
 	}
 
-	ibss.channel = ieee80211_get_channel(wiphy,
-		nla_get_u32(info->attrs[NL80211_ATTR_WIPHY_FREQ]));
+	if (info->attrs[NL80211_ATTR_WIPHY_CHANNEL_TYPE]) {
+		enum nl80211_channel_type channel_type;
+
+		channel_type = nla_get_u32(
+			info->attrs[NL80211_ATTR_WIPHY_CHANNEL_TYPE]);
+		if (channel_type != NL80211_CHAN_NO_HT &&
+				channel_type != NL80211_CHAN_HT20 &&
+				channel_type != NL80211_CHAN_HT40PLUS &&
+				channel_type != NL80211_CHAN_HT40MINUS)
+			return -EINVAL;
+		ibss.channel_type = channel_type;
+	} else {
+		ibss.channel_type = NL80211_CHAN_NO_HT;
+	}
+
+	ibss.channel = rdev_freq_to_chan(rdev,
+		nla_get_u32(info->attrs[NL80211_ATTR_WIPHY_FREQ]),
+		ibss.channel_type);
 	if (!ibss.channel ||
 	    ibss.channel->flags & IEEE80211_CHAN_NO_IBSS ||
 	    ibss.channel->flags & IEEE80211_CHAN_DISABLED)

Johannes Berg

maintainer

2011-04-12 11:08 UTC #2 lore raw

Re: [PATCH 2/4] nl80211: Add NL80211_ATTR_WIPHY_CHANNEL_TYPE for IBSS

Quoted 8 lines · Alexander Simon

Needed for IBSS IEEE802.11N operation
* Add a new attribute NL80211_ATTR_WIPHY_CHANNEL_TYPE to specify a HT channel type for IBSS
net/wireless/nl80211.c +1 -2
-	ibss.channel = ieee80211_get_channel(wiphy,
-		nla_get_u32(info->attrs[NL80211_ATTR_WIPHY_FREQ]));
+	if (info->attrs[NL80211_ATTR_WIPHY_CHANNEL_TYPE]) {

net/wireless/nl80211.c static int nl80211_join_ibss(struct sk_b · line 3940

Quoted 10 lines

net/wireless/nl80211.c +10 -0

+		enum nl80211_channel_type channel_type;
+
+		channel_type = nla_get_u32(
+			info->attrs[NL80211_ATTR_WIPHY_CHANNEL_TYPE]);
+		if (channel_type != NL80211_CHAN_NO_HT &&
+				channel_type != NL80211_CHAN_HT20 &&
+				channel_type != NL80211_CHAN_HT40PLUS &&
+				channel_type != NL80211_CHAN_HT40MINUS)
+			return -EINVAL;
+		ibss.channel_type = channel_type;

Please use Linux coding style.

net/wireless/nl80211.c static int nl80211_join_ibss(struct sk_b · line 3947

Quoted 3 lines

net/wireless/nl80211.c +3 -0

+	ibss.channel = rdev_freq_to_chan(rdev,
+		nla_get_u32(info->attrs[NL80211_ATTR_WIPHY_FREQ]),
+		ibss.channel_type);

I don't think that is sufficient. Need to check that IBSS is allowed on both channels, maybe with a function like can_beacon_sec_chan.

johannes

Alexander Simon

author

2011-04-12 11:10 UTC #3 lore raw

Re: [PATCH 3/4] mac80211: Add function to build HT caps

In reply to Alexander Simon

Some refracturing work.

Add a new function ieee80211_ie_build_ht_cap in util.c. Use this shared code from ieee80211_build_preq_ies (util.c) and ieee80211_add_ht_ie (work.c)

This will be used from ibss.c also.

Signed-off-by Alexander Simon <[email protected]>

---
 ieee80211_i.h |    2 ++
 util.c        |   54 +++++++++++++++++++++++++++++++++++++-----------------
 work.c        |   29 +----------------------------
 3 files changed, 40 insertions(+), 45 deletions(-)

net/mac80211/ieee80211_i.h +2 -0

diff -Nrup a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
@@ -1351,6 +1352,8 @@ void ieee80211_recalc_smps(struct ieee80
 size_t ieee80211_ie_split(const u8 *ies, size_t ielen,
 			  const u8 *ids, int n_ids, size_t offset);
 size_t ieee80211_ie_split_vendor(const u8 *ies, size_t ielen, size_t offset);
+u8 *ieee80211_ie_build_ht_cap(u8 *pos, struct ieee80211_supported_band *sband,
+                              u16 cap);
 
 /* internal work items */
 void ieee80211_work_init(struct ieee80211_local *local);

net/mac80211/util.c +37 ~~-17~~

63 lines not on this page · raw message

net/mac80211/work.c +1 ~~-28~~

diff -Nrup a/net/mac80211/work.c b/net/mac80211/work.c
@@ -110,7 +110,6 @@ static void ieee80211_add_ht_ie(struct s
 	u8 *pos;
 	u32 flags = channel->flags;
 	u16 cap = sband->ht_cap.cap;
-	__le16 tmp;
 
 	if (!sband->ht_cap.ht_supported)
 		return;

@@ -161,34 +160,8 @@ static void ieee80211_add_ht_ie(struct s
 	}
 
 	/* reserve and fill IE */
-
 	pos = skb_put(skb, sizeof(struct ieee80211_ht_cap) + 2);
-	*pos++ = WLAN_EID_HT_CAPABILITY;
-	*pos++ = sizeof(struct ieee80211_ht_cap);
-	memset(pos, 0, sizeof(struct ieee80211_ht_cap));
-
-	/* capability flags */
-	tmp = cpu_to_le16(cap);
-	memcpy(pos, &tmp, sizeof(u16));
-	pos += sizeof(u16);
-
-	/* AMPDU parameters */
-	*pos++ = sband->ht_cap.ampdu_factor |
-		 (sband->ht_cap.ampdu_density <<
-			IEEE80211_HT_AMPDU_PARM_DENSITY_SHIFT);
-
-	/* MCS set */
-	memcpy(pos, &sband->ht_cap.mcs, sizeof(sband->ht_cap.mcs));
-	pos += sizeof(sband->ht_cap.mcs);
-
-	/* extended capabilities */
-	pos += sizeof(__le16);
-
-	/* BF capabilities */
-	pos += sizeof(__le32);
-
-	/* antenna selection */
-	pos += sizeof(u8);
+	ieee80211_ie_build_ht_cap(pos, sband, cap);
 }
 
 static void ieee80211_send_assoc(struct ieee80211_sub_if_data *sdata,

Johannes Berg

maintainer

2011-04-12 11:16 UTC #4 lore raw

Re: [PATCH 3/4] mac80211: Add function to build HT caps

net/mac80211/util.c size_t ieee80211_ie_split_vendor(const u · line 1433

Quoted 2 lines · Alexander Simon

net/mac80211/util.c +2 -0

+u8 *ieee80211_ie_build_ht_cap(u8 *pos, struct ieee80211_supported_band *sband,
+                              u16 cap)

It makes no sense to pass cap as an argument since it's taken from the sband.

johannes

Alexander Simon

author

2011-04-12 11:22 UTC #5 lore raw

Re: [PATCH 3/4] mac80211: Add function to build HT caps

Am Dienstag, den 12.04.2011, 13:16 +0200 schrieb Johannes Berg:

Quoted 10 lines · Alexander Simon

net/mac80211/util.c size_t ieee80211_ie_split_vendor(const u · line 1433
Quoted 3 lines
net/mac80211/util.c +2 -0
+u8 *ieee80211_ie_build_ht_cap(u8 *pos, struct ieee80211_supported_band *sband,
+                              u16 cap)
It makes no sense to pass cap as an argument since it's taken from the sband.
johannes

Not true, in ieee80211_add_ht_ie in work.c cap is modified before.

Alex

Alexander Simon

author

2011-04-12 11:15 UTC #6 lore raw

Re: [PATCH 4/4] mac80211: Add IEEE802.11n for IBSS

In reply to Alexander Simon

Okay, here we go. Hopefully this meets your requirements.

* Use HT IEs from other stations for rate algo
* Parameter to set HT channel type for IBSS join
* Build HT IEs when joining an IBSS
* Allow frame aggregation sessions for IBSS

HT operation will only be started for a station after receiving a beacon. So there may be a delay running in legacy when adding a station from a data packet to a third station (prepare_for_handlers).

Signed-off-by Alexander Simon <[email protected]>

---
 agg-rx.c      |    2 +
 agg-tx.c      |    5 ++-
 ht.c          |    2 +
 ibss.c        |   94 ++++++++++++++++++++++++++++++++++++++++++++++++++--------
 ieee80211_i.h |    3 +
 rx.c          |    5 +--
 6 files changed, 95 insertions(+), 16 deletions(-)

net/mac80211/agg-rx.c +2 -0

diff -Nrup a/net/mac80211/agg-rx.c b/net/mac80211/agg-rx.c
@@ -160,6 +160,8 @@ static void ieee80211_send_addba_resp(st
 		memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
 	else if (sdata->vif.type == NL80211_IFTYPE_STATION)
 		memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
+	else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
+		memcpy(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN);
 
 	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 					  IEEE80211_STYPE_ACTION);

net/mac80211/agg-tx.c +4 -1

diff -Nrup a/net/mac80211/agg-tx.c b/net/mac80211/agg-tx.c
@@ -83,6 +83,8 @@ static void ieee80211_send_addba_request
 		memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
 	else if (sdata->vif.type == NL80211_IFTYPE_STATION)
 		memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
+	else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
+		memcpy(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN);
 
 	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 					  IEEE80211_STYPE_ACTION);

@@ -377,7 +379,8 @@ int ieee80211_start_tx_ba_session(struct
 	 */
 	if (sdata->vif.type != NL80211_IFTYPE_STATION &&
 	    sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
-	    sdata->vif.type != NL80211_IFTYPE_AP)
+	    sdata->vif.type != NL80211_IFTYPE_AP &&
+	    sdata->vif.type != NL80211_IFTYPE_ADHOC)
 		return -EINVAL;
 
 	if (test_sta_flags(sta, WLAN_STA_BLOCK_BA)) {

net/mac80211/ht.c +2 -0

diff -Nrup a/net/mac80211/ht.c b/net/mac80211/ht.c
@@ -182,6 +182,8 @@ void ieee80211_send_delba(struct ieee802
 		memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
 	else if (sdata->vif.type == NL80211_IFTYPE_STATION)
 		memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
+	else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
+		memcpy(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN);
 
 	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 					  IEEE80211_STYPE_ACTION);

net/mac80211/ibss.c +82 ~~-12~~

181 lines not on this page · raw message

net/mac80211/ieee80211_i.h +2 -1

diff -Nrup a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
@@ -439,6 +439,7 @@ struct ieee80211_if_ibss {
 	u8 ssid_len, ie_len;
 	u8 *ie;
 	struct ieee80211_channel *channel;
+	enum nl80211_channel_type channel_type;
 
 	unsigned long ibss_join_req;
 	/* probe response/beacon for IBSS */

@@ -1107,7 +1108,7 @@ void ieee80211_ibss_notify_scan_complete
 void ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data *sdata);
 struct sta_info *ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata,
 					u8 *bssid, u8 *addr, u32 supp_rates,
-					gfp_t gfp);
+					struct ieee80211_ht_cap *ht_cap, gfp_t gfp);
 int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata,
 			struct cfg80211_ibss_params *params);
 int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata);

net/mac80211/rx.c +3 -2

diff -Nrup a/net/mac80211/rx.c b/net/mac80211/rx.c
@@ -2118,7 +2118,8 @@ ieee80211_rx_h_action(struct ieee80211_r
 		 */
 		if (sdata->vif.type != NL80211_IFTYPE_STATION &&
 		    sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
-		    sdata->vif.type != NL80211_IFTYPE_AP)
+		    sdata->vif.type != NL80211_IFTYPE_AP &&
+		    sdata->vif.type != NL80211_IFTYPE_ADHOC)
 			break;
 
 		/* verify action_code is present */

@@ -2674,7 +2675,7 @@ static int prepare_for_handlers(struct i
 			else
 				rate_idx = status->rate_idx;
 			rx->sta = ieee80211_ibss_add_sta(sdata, bssid,
-					hdr->addr2, BIT(rate_idx), GFP_ATOMIC);
+					hdr->addr2, BIT(rate_idx), NULL, GFP_ATOMIC);
 		}
 		break;
 	case NL80211_IFTYPE_MESH_POINT:

Johannes Berg

maintainer

2011-04-12 11:19 UTC #7 lore raw

Re: [PATCH 4/4] mac80211: Add IEEE802.11n for IBSS

net/mac80211/ibss.c int ieee80211_ibss_join(struct ieee80211 · line 967

Quoted 9 lines · Alexander Simon

net/mac80211/ibss.c +3 -5

 	skb = dev_alloc_skb(sdata->local->hw.extra_tx_headroom +
-			    36 /* bitrates */ +
-			    34 /* SSID */ +
-			    3  /* DS params */ +
-			    4  /* IBSS params */ +
-			    params->ie_len);
+				sizeof(struct ieee80211_hdr_3addr) + 
+				12 /* struct ieee80211_mgmt.u.beacon */ +
+				2 + IEEE80211_MAX_SSID_LEN /* max SSID */ +

You have a tendency to mess up the coding style.

Also what if the IBSS is created with HT40+ and then joins, can it join HT40-? Is the channel type "advisory" like the frequency? Can it join HT20 IBSS as well?

johannes

Alexander Simon

author

2011-04-28 12:14 UTC #8 lore raw

Re: [PATCH 4/4] mac80211: Add IEEE802.11n for IBSS

Quoted 3 lines

Also what if the IBSS is created with HT40+ and then joins, can it join HT40-? Is the channel type "advisory" like the frequency? Can it join HT20 IBSS as well?

HT type can`t be advisory, as there may be stations without n.

Our card is set to HT40+/- if set by iw.
Some other station is added into our internal station list by its HT beacons. E.g. if we have configured HT40- and there is someone with HT40+, minstrel_ht should use HT20 only. But i admit it seems cleaner to AND both caps.

Johannes Berg

maintainer

2011-04-28 12:56 UTC #9 lore raw

Re: [PATCH 4/4] mac80211: Add IEEE802.11n for IBSS

Quoted 4 lines · Alexander Simon

Quoted 3 lines
Also what if the IBSS is created with HT40+ and then joins, can it join HT40-? Is the channel type "advisory" like the frequency? Can it join HT20 IBSS as well?
HT type can`t be advisory, as there may be stations without n.

Yeah, but it's possible to still communicate with them.

Quoted 4 lines

Our card is set to HT40+/- if set by iw.
Some other station is added into our internal station list by its HT beacons. E.g. if we have configured HT40- and there is someone with HT40+, minstrel_ht should use HT20 only. But i admit it seems cleaner to AND both caps.

Well. You need to consider more than just this. I have a feeling you're only considering fixed channel use cases. But if we configure HT40+, and then find a peer on a channel that may only use HT40-, then what?

johannes

Alexander Simon

author

2011-04-29 06:54 UTC #10 lore raw

Re: [PATCH 4/4] mac80211: Add IEEE802.11n for IBSS

Quoted 3 lines

Well. You need to consider more than just this. I have a feeling you're only considering fixed channel use cases. But if we configure HT40+, and then find a peer on a channel that may only use HT40-, then what?

Good point. But still i think this is the same case. Right now, the card would still be set into HT40+, regardless of the frequency. Then, minstrel_ht would just use HT20, i suppose.

My proposal would be making the HT iw argument non-advisory: Use it when creating a network, discard it when joining one.

I also will do some refactoring in nl80211.c in order to check main and extension channel.

Johannes Berg

maintainer

2011-04-29 07:21 UTC #11 lore raw

Re: [PATCH 4/4] mac80211: Add IEEE802.11n for IBSS

Quoted 10 lines · Alexander Simon

Quoted 3 lines
Well. You need to consider more than just this. I have a feeling you're only considering fixed channel use cases. But if we configure HT40+, and then find a peer on a channel that may only use HT40-, then what?
Good point. But still i think this is the same case. Right now, the card would still be set into HT40+, regardless of the frequency. Then, minstrel_ht would just use HT20, i suppose.
My proposal would be making the HT iw argument non-advisory: Use it when creating a network, discard it when joining one.

Yeah it would be an option to just always join as HT if HT is available, but not create as HT unless asked.

johannes

Alexander Simon

author

2011-04-29 08:37 UTC #12 lore raw

Re: [PATCH 4/4] mac80211: Add IEEE802.11n for IBSS

Quoted 2 lines

Yeah it would be an option to just always join as HT if HT is available, but not create as HT unless asked.

Ok. I just had a few thoughts about this:
This way an ht ibss has to be created from a (patched) mac80211 HT hardware. There would be no way to "convert" an existing g network into n.
Additionally, if a non-ht implementation joins the network, it will advertise it as non-ht. If a second ht-station joins from one of these beacons, it won't use ht.

This way a single non-ht station could destroy a ht ibss.

I Think the best way to go would be to obey HT information when joining HT but using the HT iw parameter when joining non-ht.

Then we could have the following scenario: Non-HT station A creates non-HT.
HT station B joins and sets HT- (from iw). HT station C joins from A but doesn't see B. It's iw parameter says ht+.
But when B comes closer to C do a "HT merge", comparing TSFs.

Conclusion:
- Create an ibss with the iw parameter
- When joining a ht ibss, use its parameters
- When joining non-ht, add ht from iw parameter
- When encounter a different ht config, do a ht merge.

Alexander Simon

author

2011-04-29 12:36 UTC #13 lore raw

Re: [PATCH 4/4] mac80211: Add IEEE802.11n for IBSS

Sorry for replying to myself but i'll try to explain this a little bit easier:

- If the channel is not *fixed*, the channel type is only advisory. This means that a merge of two HT40 networks with fixed channels will only take place if the HT40 configuration equals.

- When merging, the looser will obey the winner's HT configuration if there is one. If not, keep the old one.

- If HT has been configured through iw and a non-HT network is to be joined, iw's HT setting is used and announced.

HT configuration within an IBSS may get inhomogeneous as a HT station may join from a non-HT beacon but there are other HT members.

- When receiving a different HT configuration from another member of our BSSID, use this configuration (first beacon wins)

Alex

Johannes Berg

maintainer

2011-04-29 12:39 UTC #14 lore raw

Re: [PATCH 4/4] mac80211: Add IEEE802.11n for IBSS

Quoted 2 lines · Alexander Simon

- If HT has been configured through iw and a non-HT network is to be joined, iw's HT setting is used and announced.

This isn't possible, you might join a network on a channel that doesn't allow HT40+ for example.

johannes

Alexander Simon

author

2011-04-29 12:50 UTC #15 lore raw

Re: [PATCH 4/4] mac80211: Add IEEE802.11n for IBSS

Quoted 5 lines

Quoted 2 lines
- If HT has been configured through iw and a non-HT network is to be joined, iw's HT setting is used and announced.
This isn't possible, you might join a network on a channel that doesn't allow HT40+ for example.

Of course it must be checked.
It has to be checked even when joining HT networks.
E.g. a european user travels to America and opens an HT+ Network on channel 9. The american card should disable HT40+.

John W. Linville

2011-04-26 19:15 UTC #16 lore raw

In reply to Alexander Simon

Quoted 5 lines · Alexander Simon

Needed for IBSS IEEE802.11N operation
* Add ht channel type for cfg80211 IBSS configuration
Signed-off-by Alexander Simon <[email protected]>

Are you going to resubmit this series after addressing Johannes's comments?

Signature · 2 lines

John W. Linville		Someday the world will need a hero, and you
[email protected]			might be all we have.  Be ready.

Alexander Simon

author

2011-04-28 12:20 UTC #17 lore raw

Yes, i am.