From: Benjamin Berg <benjamin.berg@xxxxxxxxx>
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: Benjamin Berg <benjamin.berg@xxxxxxxxx>
Signed-off-by: Gregory Greenman <gregory.greenman@xxxxxxxxx>
---
include/net/cfg80211.h | 3 +++
net/wireless/nl80211.c | 50 +++++++++++++++++++++++++++++++++++++-----
2 files changed, 47 insertions(+), 6 deletions(-)
diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 9af714431b22..0115fd9bf33a 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -2964,12 +2964,15 @@ 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;
};
/**
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index e64bf2a58b36..74eaf74f153a 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -10942,8 +10942,9 @@ 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,
- "non-inheritance makes no sense");
+ NL_SET_ERR_MSG_ATTR(info->extack,
+ info->attrs[NL80211_ATTR_IE],
+ "non-inheritance makes no sense");
return -EINVAL;
}
}
@@ -11068,6 +11069,7 @@ 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;
}
@@ -11075,6 +11077,7 @@ 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 =
@@ -11082,6 +11085,8 @@ 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;
}
@@ -11094,8 +11099,9 @@ 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,
- "cannot deal with fragmentation");
+ NL_SET_ERR_MSG_ATTR(info->extack,
+ attrs[NL80211_ATTR_IE],
+ "cannot deal with fragmentation");
err = -EINVAL;
goto free;
}
@@ -11103,8 +11109,9 @@ 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,
- "cannot deal with non-inheritance");
+ NL_SET_ERR_MSG_ATTR(info->extack,
+ attrs[NL80211_ATTR_IE],
+ "cannot deal with non-inheritance");
err = -EINVAL;
goto free;
}
@@ -11147,6 +11154,9 @@ 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]) {
@@ -11155,6 +11165,34 @@ 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:
--
2.38.1
