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mac80211: Support iwconfig enc restricted with WEP

PATCH In review Ortwin Glück 2 participants 4 messages Sep 15, 2008 mac80211

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Ortwin Glück

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#0 lore raw

PATCH 1/2 mac80211: Support iwconfig enc restricted with WEP

The mac80211 code doesn't handle WEP with shared keys correctly. Using the ath9k driver on my MacBook I am unable to put the driver into restricted mode (shared key). It stays in open mode. That is the following command has no effect: iwconfig wlan0 enc restricted. I can also confirm this when looking at the authentication packets that go over the air: they are sent with the open flag, and not the shared key flag.

Signed-off-by Ortwin Glueck <[email protected]>
---
 net/mac80211/wext.c |   12 ++++++++++++
 1 files changed, 12 insertions(+), 0 deletions(-)
net/mac80211/wext.c +12 -0
index 34fa8ed..645c276 100644
@@ -929,6 +929,18 @@ static int ieee80211_ioctl_siwencode(struct net_device *dev,
 	else
 		idx--;
 
+	if (sdata->vif.type == IEEE80211_IF_TYPE_STA) {
+		struct ieee80211_if_sta *ifsta = &sdata->u.sta;
+		if (erq->flags & IW_ENCODE_OPEN) {
+			printk("wext: open\n");
+			ifsta->auth_alg = WLAN_AUTH_OPEN;
+		}
+		else if (erq->flags & IW_ENCODE_RESTRICTED) {
+			printk("wext: shared key\n");
+			ifsta->auth_alg = WLAN_AUTH_SHARED_KEY;
+		}
+	}
+
 	if (erq->flags & IW_ENCODE_DISABLED)
 		remove = 1;
 	else if (erq->length == 0) {
Signature · 1 line
1.5.6.4
maintainer
#1 lore raw
Quoted 20 lines · Ortwin Glück

The mac80211 code doesn't handle WEP with shared keys correctly. Using the ath9k driver on my MacBook I am unable to put the driver into restricted mode (shared key). It stays in open mode. That is the following command has no effect:
iwconfig wlan0 enc restricted. I can also confirm this when looking at the authentication packets that go over the air: they are sent with the open flag, and not the shared key flag.

Signed-off-by Ortwin Glueck <[email protected]>
---
  net/mac80211/wext.c |   12 ++++++++++++
  1 files changed, 12 insertions(+), 0 deletions(-)
net/mac80211/wext.c +0 -0
index 34fa8ed..645c276 100644
@@ -929,6 +929,18 @@ static int ieee80211_ioctl_siwencode(struct net_device *dev,
  	else
  		idx--;

net/mac80211/wext.c static int ieee80211_ioctl_siwencode(struct net_device *dev, · line 941

Quoted 10 lines
net/mac80211/wext.c +10 -0
+	if (sdata->vif.type == IEEE80211_IF_TYPE_STA) {
+		struct ieee80211_if_sta *ifsta = &sdata->u.sta;
+		if (erq->flags & IW_ENCODE_OPEN) {
+			printk("wext: open\n");
+			ifsta->auth_alg = WLAN_AUTH_OPEN;
+		}
+		else if (erq->flags & IW_ENCODE_RESTRICTED) {
+			printk("wext: shared key\n");
+			ifsta->auth_alg = WLAN_AUTH_SHARED_KEY;
+		}

remove the printks please

johannes

maintainer
#2 lore raw
In reply to Ortwin Glück
Quoted 20 lines · Ortwin Glück

The mac80211 code doesn't handle WEP with shared keys correctly. Using the ath9k driver on my MacBook I am unable to put the driver into restricted mode (shared key). It stays in open mode. That is the following command has no effect:
iwconfig wlan0 enc restricted. I can also confirm this when looking at the authentication packets that go over the air: they are sent with the open flag, and not the shared key flag.

Signed-off-by Ortwin Glueck <[email protected]>
---
  net/mac80211/wext.c |   12 ++++++++++++
  1 files changed, 12 insertions(+), 0 deletions(-)
net/mac80211/wext.c +0 -0
index 34fa8ed..645c276 100644
@@ -929,6 +929,18 @@ static int ieee80211_ioctl_siwencode(struct net_device *dev,
  	else
  		idx--;

net/mac80211/wext.c static int ieee80211_ioctl_siwencode(struct net_device *dev, · line 941

Quoted 10 lines
net/mac80211/wext.c +10 -0
+	if (sdata->vif.type == IEEE80211_IF_TYPE_STA) {
+		struct ieee80211_if_sta *ifsta = &sdata->u.sta;
+		if (erq->flags & IW_ENCODE_OPEN) {
+			printk("wext: open\n");
+			ifsta->auth_alg = WLAN_AUTH_OPEN;
+		}
+		else if (erq->flags & IW_ENCODE_RESTRICTED) {
+			printk("wext: shared key\n");
+			ifsta->auth_alg = WLAN_AUTH_SHARED_KEY;
+

Come to think of it, since we already fall back from open to shared-key when the AP rejects, why would we want to support this at all? The semantics aren't well defined enough to support it _properly_, that is have it change the ifsta->auth_algs variable, and touching this variable as you're doing in these two patches is just plain wrong since it can be changed underneath (yes, you're removing the automatic changing, but that's totally wrong).

johannes

maintainer
#3 lore raw
Quoted 11 lines · Johannes Berg

net/mac80211/wext.c static int ieee80211_ioctl_siwencode(struct net_device *dev, · line 943

Quoted 10 lines
net/mac80211/wext.c +10 -0
+	if (sdata->vif.type == IEEE80211_IF_TYPE_STA) {
+		struct ieee80211_if_sta *ifsta = &sdata->u.sta;
+		if (erq->flags & IW_ENCODE_OPEN) {
+			printk("wext: open\n");
+			ifsta->auth_alg = WLAN_AUTH_OPEN;
+		}
+		else if (erq->flags & IW_ENCODE_RESTRICTED) {
+			printk("wext: shared key\n");
+			ifsta->auth_alg = WLAN_AUTH_SHARED_KEY;
+
Quoted 7 lines

Come to think of it, since we already fall back from open to shared-key when the AP rejects, why would we want to support this at all? The semantics aren't well defined enough to support it _properly_, that is have it change the ifsta->auth_algs variable, and touching this variable as you're doing in these two patches is just plain wrong since it can be changed underneath (yes, you're removing the automatic changing, but that's totally wrong).

Then again, I suppose you _can_ actually implement this, but in terms of which authentication algorithms are allowed, something like:

if (erq->flags & RESTRICTED)

	ifsta->auth_algs = SHARED;
else
	ifsta->auth_algs = OPEN | SHARED | LEAP;

johannes