diff mbox series

[v4,5/6] mac80211: use ieee802_11_parse_elems() to find ies instead of ieee80211_bss_get_ie()

Message ID 20210924100052.32029-6-wgong@codeaurora.org (mailing list archive)
State Accepted
Delegated to: Johannes Berg
Headers show
Series cfg80211/mac80211: Add support for 6GHZ STA for various modes : LPI, SP and VLP | expand

Commit Message

Wen Gong Sept. 24, 2021, 10 a.m. UTC 
In function ieee80211_prep_channel(), it has some ieee80211_bss_get_ie()
and cfg80211_find_ext_ie() to get the IE, this is to use another
function ieee802_11_parse_elems() to get all the IEs in one time.

Signed-off-by: Wen Gong <wgong@codeaurora.org>
---
 net/mac80211/mlme.c | 52 +++++++++++++++++++++++++++++++--------------
 1 file changed, 36 insertions(+), 16 deletions(-)

Comments

Johannes Berg Sept. 24, 2021, 10:13 a.m. UTC | #1 
Taking a brief look before lunch,

>  	if (!(ifmgd->flags & IEEE80211_STA_DISABLE_HT) && !is_6ghz) {
>  		const u8 *ht_oper_ie, *ht_cap_ie;
>  
> 
> 
> 
> -		ht_oper_ie = ieee80211_bss_get_ie(cbss, WLAN_EID_HT_OPERATION);
> +		ht_oper_ie = elems->ht_operation ?
> +			((const u8 *)elems->ht_operation) - 2 :
> +			NULL;
>  		if (ht_oper_ie && ht_oper_ie[1] >= sizeof(*ht_oper))
>  			ht_oper = (void *)(ht_oper_ie + 2);

Can't we drop these checks, and simply do

ht_oper = elems->ht_operation?

After all, ieee802_11_parse_elems() should already be doing the
necessary length checks? We just didn't have that with
ieee80211_bss_get_ie().

> -		ht_cap_ie = ieee80211_bss_get_ie(cbss, WLAN_EID_HT_CAPABILITY);
> +		ht_cap_ie = elems->ht_cap_elem ?
> +			((const u8 *)elems->ht_cap_elem) - 2 :
> +			NULL;
>  		if (ht_cap_ie && ht_cap_ie[1] >= sizeof(*ht_cap))
>  			ht_cap = (void *)(ht_cap_ie + 2);

Likewise for all the others.

johannes
Johannes Berg Sept. 24, 2021, 10:47 a.m. UTC | #2 
On Fri, 2021-09-24 at 12:13 +0200, Johannes Berg wrote:
> Taking a brief look before lunch,
> 
> >  	if (!(ifmgd->flags & IEEE80211_STA_DISABLE_HT) && !is_6ghz) {
> >  		const u8 *ht_oper_ie, *ht_cap_ie;
> >  
> > 
> > 
> > 
> > -		ht_oper_ie = ieee80211_bss_get_ie(cbss, WLAN_EID_HT_OPERATION);
> > +		ht_oper_ie = elems->ht_operation ?
> > +			((const u8 *)elems->ht_operation) - 2 :
> > +			NULL;
> >  		if (ht_oper_ie && ht_oper_ie[1] >= sizeof(*ht_oper))
> >  			ht_oper = (void *)(ht_oper_ie + 2);
> 
> Can't we drop these checks, and simply do
> 
> ht_oper = elems->ht_operation?

I checked, yes, we can do that. Since I just did it anyway, no need to
resend.

johannes
diff mbox series

Patch

diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index e80f3388b0c5..6e8e90ee8b6c 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -4998,10 +4998,22 @@  static int ieee80211_prep_channel(struct ieee80211_sub_if_data *sdata,
 	bool is_6ghz = cbss->channel->band == NL80211_BAND_6GHZ;
 	bool is_5ghz = cbss->channel->band == NL80211_BAND_5GHZ;
 	struct ieee80211_bss *bss = (void *)cbss->priv;
+	struct ieee802_11_elems *elems;
+	const struct cfg80211_bss_ies *ies;
 	int ret;
 	u32 i;
 	bool have_80mhz;
 
+	rcu_read_lock();
+
+	ies = rcu_dereference(cbss->ies);
+	elems = ieee802_11_parse_elems(ies->data, ies->len, false,
+				       NULL, NULL);
+	if (!elems) {
+		rcu_read_unlock();
+		return -EINVAL;
+	}
+
 	sband = local->hw.wiphy->bands[cbss->channel->band];
 
 	ifmgd->flags &= ~(IEEE80211_STA_DISABLE_40MHZ |
@@ -5024,16 +5036,18 @@  static int ieee80211_prep_channel(struct ieee80211_sub_if_data *sdata,
 					 ieee80211_vif_type_p2p(&sdata->vif)))
 		ifmgd->flags |= IEEE80211_STA_DISABLE_HE;
 
-	rcu_read_lock();
-
 	if (!(ifmgd->flags & IEEE80211_STA_DISABLE_HT) && !is_6ghz) {
 		const u8 *ht_oper_ie, *ht_cap_ie;
 
-		ht_oper_ie = ieee80211_bss_get_ie(cbss, WLAN_EID_HT_OPERATION);
+		ht_oper_ie = elems->ht_operation ?
+			((const u8 *)elems->ht_operation) - 2 :
+			NULL;
 		if (ht_oper_ie && ht_oper_ie[1] >= sizeof(*ht_oper))
 			ht_oper = (void *)(ht_oper_ie + 2);
 
-		ht_cap_ie = ieee80211_bss_get_ie(cbss, WLAN_EID_HT_CAPABILITY);
+		ht_cap_ie = elems->ht_cap_elem ?
+			((const u8 *)elems->ht_cap_elem) - 2 :
+			NULL;
 		if (ht_cap_ie && ht_cap_ie[1] >= sizeof(*ht_cap))
 			ht_cap = (void *)(ht_cap_ie + 2);
 
@@ -5046,8 +5060,9 @@  static int ieee80211_prep_channel(struct ieee80211_sub_if_data *sdata,
 	if (!(ifmgd->flags & IEEE80211_STA_DISABLE_VHT) && !is_6ghz) {
 		const u8 *vht_oper_ie, *vht_cap;
 
-		vht_oper_ie = ieee80211_bss_get_ie(cbss,
-						   WLAN_EID_VHT_OPERATION);
+		vht_oper_ie = elems->vht_operation ?
+			((const u8 *)elems->vht_operation) - 2 :
+			NULL;
 		if (vht_oper_ie && vht_oper_ie[1] >= sizeof(*vht_oper))
 			vht_oper = (void *)(vht_oper_ie + 2);
 		if (vht_oper && !ht_oper) {
@@ -5059,7 +5074,9 @@  static int ieee80211_prep_channel(struct ieee80211_sub_if_data *sdata,
 			ifmgd->flags |= IEEE80211_STA_DISABLE_HE;
 		}
 
-		vht_cap = ieee80211_bss_get_ie(cbss, WLAN_EID_VHT_CAPABILITY);
+		vht_cap = elems->vht_cap_elem ?
+			((const u8 *)elems->vht_cap_elem) - 2 :
+			NULL;
 		if (!vht_cap || vht_cap[1] < sizeof(struct ieee80211_vht_cap)) {
 			ifmgd->flags |= IEEE80211_STA_DISABLE_VHT;
 			vht_oper = NULL;
@@ -5067,12 +5084,11 @@  static int ieee80211_prep_channel(struct ieee80211_sub_if_data *sdata,
 	}
 
 	if (!(ifmgd->flags & IEEE80211_STA_DISABLE_HE)) {
-		const struct cfg80211_bss_ies *ies;
 		const u8 *he_oper_ie;
 
-		ies = rcu_dereference(cbss->ies);
-		he_oper_ie = cfg80211_find_ext_ie(WLAN_EID_EXT_HE_OPERATION,
-						  ies->data, ies->len);
+		he_oper_ie = elems->he_operation ?
+			((const u8 *)elems->he_operation) - 3 :
+			NULL;
 		if (he_oper_ie &&
 		    he_oper_ie[1] >= ieee80211_he_oper_size(&he_oper_ie[3]))
 			he_oper = (void *)(he_oper_ie + 3);
@@ -5100,8 +5116,9 @@  static int ieee80211_prep_channel(struct ieee80211_sub_if_data *sdata,
 	if (sband->band == NL80211_BAND_S1GHZ) {
 		const u8 *s1g_oper_ie;
 
-		s1g_oper_ie = ieee80211_bss_get_ie(cbss,
-						   WLAN_EID_S1G_OPERATION);
+		s1g_oper_ie = elems->s1g_oper ?
+			((const u8 *)elems->s1g_oper) - 2 :
+			NULL;
 		if (s1g_oper_ie && s1g_oper_ie[1] >= sizeof(*s1g_oper))
 			s1g_oper = (void *)(s1g_oper_ie + 2);
 		else
@@ -5123,7 +5140,8 @@  static int ieee80211_prep_channel(struct ieee80211_sub_if_data *sdata,
 
 	if (ifmgd->flags & IEEE80211_STA_DISABLE_HE && is_6ghz) {
 		sdata_info(sdata, "Rejecting non-HE 6/7 GHz connection");
-		return -EINVAL;
+		ret = -EINVAL;
+		goto out_no_lock;
 	}
 
 	/* will change later if needed */
@@ -5141,15 +5159,17 @@  static int ieee80211_prep_channel(struct ieee80211_sub_if_data *sdata,
 	/* don't downgrade for 5 and 10 MHz channels, though. */
 	if (chandef.width == NL80211_CHAN_WIDTH_5 ||
 	    chandef.width == NL80211_CHAN_WIDTH_10)
-		goto out;
+		goto out_lock;
 
 	while (ret && chandef.width != NL80211_CHAN_WIDTH_20_NOHT) {
 		ifmgd->flags |= ieee80211_chandef_downgrade(&chandef);
 		ret = ieee80211_vif_use_channel(sdata, &chandef,
 						IEEE80211_CHANCTX_SHARED);
 	}
- out:
+ out_lock:
 	mutex_unlock(&local->mtx);
+ out_no_lock:
+	kfree(elems);
 	return ret;
 }