diff mbox series

[05/28] wifi: cfg80211: support reporting failed links

Message ID 20221005145226.2224328320e7.I53966b9c7572fe1a08a7dc02ed29be9e1b0467fc@changeid (mailing list archive)
State Accepted
Delegated to: Johannes Berg
Headers show
Series wifi: further MLO work | expand

Commit Message

Johannes Berg Oct. 5, 2022, 1 p.m. UTC 
From: Johannes Berg <johannes.berg@intel.com>

For assoc and connect result APIs, support reporting
failed links; they should still come with the BSS
pointer in the case of assoc, so they're released
correctly. In the case of connect result, this is
optional.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 include/net/cfg80211.h |  7 +++++++
 net/wireless/mlme.c    |  4 ++++
 net/wireless/nl80211.c |  5 ++++-
 net/wireless/sme.c     | 14 ++++++++++++++
 4 files changed, 29 insertions(+), 1 deletion(-)

Comments

Veerendranath Jakkam Oct. 6, 2022, 10:49 a.m. UTC | #1 
I think similar enhancement needed for cfg80211_roamed/NL80211_CMD_ROAM 
also to know accepted and rejected links info during roaming.

- veeru
Johannes Berg Oct. 6, 2022, 10:51 a.m. UTC | #2 
On Thu, 2022-10-06 at 16:19 +0530, Veerendranath Jakkam wrote:
> I think similar enhancement needed for cfg80211_roamed/NL80211_CMD_ROAM 
> also to know accepted and rejected links info during roaming.
> 

Not sure, in that case we might care only about the successful links
since wpa_s didn't request the others, so maybe it doesn't matter?

In any case, I have no driver I deal with that would ever use this API,
so I can't really do anything about it.

johannes
Veerendranath Jakkam Oct. 6, 2022, 11:09 a.m. UTC | #3 
On 10/6/2022 4:21 PM, Johannes Berg wrote:
> On Thu, 2022-10-06 at 16:19 +0530, Veerendranath Jakkam wrote:
>> I think similar enhancement needed for cfg80211_roamed/NL80211_CMD_ROAM
>> also to know accepted and rejected links info during roaming.
>>
> Not sure, in that case we might care only about the successful links
> since wpa_s didn't request the others, so maybe it doesn't matter?

Drivers can offload EAPOL 4WHS to wpa_supplicant during roaming with 
non-FT AKMs. In that case supplicant needs to know rejected links info 
to validate AP's MLO Link KDEs in 3/4 frame.

Ex: Driver handles only re-association request and response frames while 
doing roaming with non-FT AKM then offload 4WHS to wpa_supplicant

>
> In any case, I have no driver I deal with that would ever use this API,
> so I can't really do anything about it.

No problem, I will post the required changes for 
cfg80211_roamed/NL80211_CMD_ROAM path, hope that is fine.

>
> johannes
Johannes Berg Oct. 6, 2022, 11:11 a.m. UTC | #4 
On Thu, 2022-10-06 at 16:39 +0530, Veerendranath Jakkam wrote:
> On 10/6/2022 4:21 PM, Johannes Berg wrote:
> > On Thu, 2022-10-06 at 16:19 +0530, Veerendranath Jakkam wrote:
> > > I think similar enhancement needed for cfg80211_roamed/NL80211_CMD_ROAM
> > > also to know accepted and rejected links info during roaming.
> > > 
> > Not sure, in that case we might care only about the successful links
> > since wpa_s didn't request the others, so maybe it doesn't matter?
> 
> Drivers can offload EAPOL 4WHS to wpa_supplicant during roaming with 
> non-FT AKMs. In that case supplicant needs to know rejected links info 
> to validate AP's MLO Link KDEs in 3/4 frame.
> 
> Ex: Driver handles only re-association request and response frames while 
> doing roaming with non-FT AKM then offload 4WHS to wpa_supplicant
> 

Right, but is there a fundamental difference between

 "hey I roamed to this AP MLD with links 1, 2 and 5"
 (with the right BSSIDs for the links etc.)

and

 "hey I roamed to this AP MLD and I tried links 1, 2, 3, 4, 5 but only
1, 2 and 5 were established"

?

johannes
Veerendranath Jakkam Oct. 6, 2022, 2:40 p.m. UTC | #5 
On 10/6/2022 4:41 PM, Johannes Berg wrote:
> Right, but is there a fundamental difference between
>   "hey I roamed to this AP MLD with links 1, 2 and 5"
>   (with the right BSSIDs for the links etc.)
>
> and
>
>   "hey I roamed to this AP MLD and I tried links 1, 2, 3, 4, 5 but only
> 1, 2 and 5 were established"
>
> ?

supplicant must validate MLO Link KDEs(includes RSNE and RSNXE) for all 
the negotiated links but MLO GTK/IGTK/BIGTK only for accepted links 
while processing 3/4 msg.

So, during roaming if EAPOL 4HS is offload to supplicant it should know 
the requested and accepted links information.

non-AP MLD needs to select common AKM across all the links. The MLO Link 
KDEs validation helps to avoid downgrade attacks.

- veeru
diff mbox series

Patch

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index e09ff87146c1..4d35a4234417 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -6933,6 +6933,8 @@  void cfg80211_auth_timeout(struct net_device *dev, const u8 *addr);
  * @ap_mld_addr: AP MLD address (in case of MLO)
  * @links: per-link information indexed by link ID, use links[0] for
  *	non-MLO connections
+ * @links.status: Set this (along with a BSS pointer) for links that
+ *	were rejected by the AP.
  */
 struct cfg80211_rx_assoc_resp {
 	const u8 *buf;
@@ -6944,6 +6946,7 @@  struct cfg80211_rx_assoc_resp {
 	struct {
 		const u8 *addr;
 		struct cfg80211_bss *bss;
+		u16 status;
 	} links[IEEE80211_MLD_MAX_NUM_LINKS];
 };
 
@@ -7454,6 +7457,9 @@  struct cfg80211_fils_resp_params {
  *	if the bss is expired during the connection, esp. for those drivers
  *	implementing connect op. Only one parameter among @bssid and @bss needs
  *	to be specified.
+ * @links.status: per-link status code, to report a status code that's not
+ *	%WLAN_STATUS_SUCCESS for a given link, it must also be in the
+ *	@valid_links bitmap and may have a BSS pointer (which is then released)
  */
 struct cfg80211_connect_resp_params {
 	int status;
@@ -7470,6 +7476,7 @@  struct cfg80211_connect_resp_params {
 		const u8 *addr;
 		const u8 *bssid;
 		struct cfg80211_bss *bss;
+		u16 status;
 	} links[IEEE80211_MLD_MAX_NUM_LINKS];
 };
 
diff --git a/net/wireless/mlme.c b/net/wireless/mlme.c
index 581df7f4c524..58e1fb18f85a 100644
--- a/net/wireless/mlme.c
+++ b/net/wireless/mlme.c
@@ -42,6 +42,10 @@  void cfg80211_rx_assoc_resp(struct net_device *dev,
 	unsigned int link_id;
 
 	for (link_id = 0; link_id < ARRAY_SIZE(data->links); link_id++) {
+		cr.links[link_id].status = data->links[link_id].status;
+		WARN_ON_ONCE(cr.links[link_id].status != WLAN_STATUS_SUCCESS &&
+			     (!cr.ap_mld_addr || !cr.links[link_id].bss));
+
 		cr.links[link_id].bss = data->links[link_id].bss;
 		if (!cr.links[link_id].bss)
 			continue;
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 8ff8b1c040f0..ad7393cd3d18 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -17745,6 +17745,7 @@  void nl80211_send_connect_result(struct cfg80211_registered_device *rdev,
 			link_info_size += (cr->links[link].bssid ||
 					   cr->links[link].bss) ?
 					  nla_total_size(ETH_ALEN) : 0;
+			link_info_size += nla_total_size(sizeof(u16));
 		}
 	}
 
@@ -17813,7 +17814,9 @@  void nl80211_send_connect_result(struct cfg80211_registered_device *rdev,
 			     nla_put(msg, NL80211_ATTR_BSSID, ETH_ALEN, bssid)) ||
 			    (cr->links[link].addr &&
 			     nla_put(msg, NL80211_ATTR_MAC, ETH_ALEN,
-				     cr->links[link].addr)))
+				     cr->links[link].addr)) ||
+			    nla_put_u16(msg, NL80211_ATTR_STATUS_CODE,
+					cr->links[link].status))
 				goto nla_put_failure;
 
 			nla_nest_end(msg, nested_mlo_links);
diff --git a/net/wireless/sme.c b/net/wireless/sme.c
index d513536617bd..f94497e9db43 100644
--- a/net/wireless/sme.c
+++ b/net/wireless/sme.c
@@ -793,6 +793,10 @@  void __cfg80211_connect_result(struct net_device *dev,
 		}
 
 		for_each_valid_link(cr, link) {
+			/* don't do extra lookups for failures */
+			if (cr->links[link].status != WLAN_STATUS_SUCCESS)
+				continue;
+
 			if (cr->links[link].bss)
 				continue;
 
@@ -829,6 +833,16 @@  void __cfg80211_connect_result(struct net_device *dev,
 	}
 
 	memset(wdev->links, 0, sizeof(wdev->links));
+	for_each_valid_link(cr, link) {
+		if (cr->links[link].status == WLAN_STATUS_SUCCESS)
+			continue;
+		cr->valid_links &= ~BIT(link);
+		/* don't require bss pointer for failed links */
+		if (!cr->links[link].bss)
+			continue;
+		cfg80211_unhold_bss(bss_from_pub(cr->links[link].bss));
+		cfg80211_put_bss(wdev->wiphy, cr->links[link].bss);
+	}
 	wdev->valid_links = cr->valid_links;
 	for_each_valid_link(cr, link)
 		wdev->links[link].client.current_bss =