Commit a7b2cc59 authored by Benjamin Berg's avatar Benjamin Berg Committed by Johannes Berg
Browse files

wifi: cfg80211: report per-link errors during association 



When one of the links (other than the assoc_link) is misconfigured
and cannot work the association will fail. However, userspace was not
able to tell that the operation only failed because of a problem with
one of the links. Fix this, by allowing the driver to set a per-link
error code and reporting the (first) offending link by setting the
bad_attr accordingly.

This only allows us to report the first error, but that is sufficient
for userspace to e.g. remove the offending link and retry.

Signed-off-by: default avatarBenjamin Berg <benjamin.berg@intel.com>
Signed-off-by: default avatarGregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20230920211508.ebe63c0bd513.I40799998f02bf987acee1501a2522dc98bb6eb5a@changeid


Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
parent ef246a14

include/net/cfg80211.h

+3 −0
Original line number Diff line number Diff line
@@ -2980,12 +2980,15 @@ struct cfg80211_auth_request { 
 * @elems_len: length of the elements

 * @disabled: If set this link should be included during association etc. but it

 *	should not be used until enabled by the AP MLD.

 * @error: per-link error code, must be <= 0. If there is an error, then the

 *	operation as a whole must fail.

 */

struct cfg80211_assoc_link {

	struct cfg80211_bss *bss;

	const u8 *elems;

	size_t elems_len;

	bool disabled;

	int error;

};



/**

net/wireless/nl80211.c

+44 −6
Original line number Diff line number Diff line
@@ -10941,7 +10941,8 @@ static int nl80211_associate(struct sk_buff *skb, struct genl_info *info) 








		if (cfg80211_find_ext_elem(WLAN_EID_EXT_NON_INHERITANCE,









					   req.ie, req.ie_len)) {









			GENL_SET_ERR_MSG(info,









			NL_SET_ERR_MSG_ATTR(info->extack,









					    info->attrs[NL80211_ATTR_IE],









					    "non-inheritance makes no sense");









			return -EINVAL;









		}








@@ -11067,6 +11068,7 @@ static int nl80211_associate(struct sk_buff *skb, struct genl_info *info)















			if (!attrs[NL80211_ATTR_MLO_LINK_ID]) {









				err = -EINVAL;









				NL_SET_BAD_ATTR(info->extack, link);









				goto free;









			}
















@@ -11074,6 +11076,7 @@ static int nl80211_associate(struct sk_buff *skb, struct genl_info *info)







			/* cannot use the same link ID again */









			if (req.links[link_id].bss) {









				err = -EINVAL;









				NL_SET_BAD_ATTR(info->extack, link);









				goto free;









			}









			req.links[link_id].bss =








@@ -11081,6 +11084,8 @@ static int nl80211_associate(struct sk_buff *skb, struct genl_info *info)







			if (IS_ERR(req.links[link_id].bss)) {









				err = PTR_ERR(req.links[link_id].bss);









				req.links[link_id].bss = NULL;









				NL_SET_ERR_MSG_ATTR(info->extack,









						    link, "Error fetching BSS for link");









				goto free;









			}
















@@ -11093,7 +11098,8 @@ static int nl80211_associate(struct sk_buff *skb, struct genl_info *info)







				if (cfg80211_find_elem(WLAN_EID_FRAGMENT,









						       req.links[link_id].elems,









						       req.links[link_id].elems_len)) {









					GENL_SET_ERR_MSG(info,









					NL_SET_ERR_MSG_ATTR(info->extack,









							    attrs[NL80211_ATTR_IE],









							    "cannot deal with fragmentation");









					err = -EINVAL;









					goto free;








@@ -11102,7 +11108,8 @@ static int nl80211_associate(struct sk_buff *skb, struct genl_info *info)







				if (cfg80211_find_ext_elem(WLAN_EID_EXT_NON_INHERITANCE,









							   req.links[link_id].elems,









							   req.links[link_id].elems_len)) {









					GENL_SET_ERR_MSG(info,









					NL_SET_ERR_MSG_ATTR(info->extack,









							    attrs[NL80211_ATTR_IE],









							    "cannot deal with non-inheritance");









					err = -EINVAL;









					goto free;








@@ -11146,6 +11153,9 @@ static int nl80211_associate(struct sk_buff *skb, struct genl_info *info)















	err = nl80211_crypto_settings(rdev, info, &req.crypto, 1);









	if (!err) {









		struct nlattr *link;









		int rem = 0;

















		err = cfg80211_mlme_assoc(rdev, dev, &req);

















		if (!err && info->attrs[NL80211_ATTR_SOCKET_OWNER]) {








@@ -11154,6 +11164,34 @@ static int nl80211_associate(struct sk_buff *skb, struct genl_info *info)







			memcpy(dev->ieee80211_ptr->disconnect_bssid,









			       ap_addr, ETH_ALEN);









		}

















		/* Report error from first problematic link */









		if (info->attrs[NL80211_ATTR_MLO_LINKS]) {









			nla_for_each_nested(link,









					    info->attrs[NL80211_ATTR_MLO_LINKS],









					    rem) {









				struct nlattr *link_id_attr =









					nla_find_nested(link, NL80211_ATTR_MLO_LINK_ID);

















				if (!link_id_attr)









					continue;

















				link_id = nla_get_u8(link_id_attr);

















				if (link_id == req.link_id)









					continue;

















				if (!req.links[link_id].error ||









				    WARN_ON(req.links[link_id].error > 0))









					continue;

















				WARN_ON(err >= 0);

















				NL_SET_BAD_ATTR(info->extack, link);









				err = req.links[link_id].error;









				break;









			}









		}









	}

















free: