[PATCH wireless v5] wifi: cfg80211: Set SSID if it is not already set

[Marc Bornand <dev.mbornand@systemb.ch>]

When a connection was established without going through
NL80211_CMD_CONNECT, the ssid was never set in the wireless_dev struct.
Now we set it in __cfg80211_connect_result() when it is not already set.

When using a userspace configuration that does not call
cfg80211_connect() (can be checked with breakpoints in the kernel),
this patch should allow `networkctl status device_name` to output the
SSID instead of null.

Reported-by: Yohan Prod'homme <kernel@zoddo.fr>
Fixes: 7b0a0e3c3a88 (wifi: cfg80211: do some rework towards MLO link APIs)
CC: Kalle Valo <kvalo@kernel.org>
Cc: Denis Kirjanov <dkirjanov@suse.de>
Cc: linux-wireless@vger.kernel.org
Cc: stable@vger.kernel.org
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216711
Signed-off-by: Marc Bornand <dev.mbornand@systemb.ch>
---
changes since v4:
- style: use xmas tree
- better fixes tag
- fix typo in commit message
- explain how to test the patch
- fix fixes tag
- move change log
- changing the title to something better

changes since v3:
- add missing NULL check
- add missing break

changes since v2:
- The code was tottaly rewritten based on the disscution of the
  v2 patch.
- the ssid is set in __cfg80211_connect_result() and only if the ssid is
  not already set.
- Do not add an other ssid reset path since it is already done in
  __cfg80211_disconnected()
---
 net/wireless/sme.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/net/wireless/sme.c b/net/wireless/sme.c
index 4b5b6ee0fe01..032464a38787 100644
--- a/net/wireless/sme.c
+++ b/net/wireless/sme.c
@@ -724,6 +724,7 @@ void __cfg80211_connect_result(struct net_device *dev,
 {
 	struct wireless_dev *wdev = dev->ieee80211_ptr;
 	const struct element *country_elem = NULL;
+	const struct element *ssid;
 	const u8 *country_data;
 	u8 country_datalen;
 #ifdef CONFIG_CFG80211_WEXT
@@ -883,6 +884,22 @@ void __cfg80211_connect_result(struct net_device *dev,
 				   country_data, country_datalen);
 	kfree(country_data);

+	if (wdev->u.client.ssid_len == 0) {
+		rcu_read_lock();
+		for_each_valid_link(cr, link) {
+			ssid = ieee80211_bss_get_elem(cr->links[link].bss,
+						      WLAN_EID_SSID);
+
+			if (!ssid || ssid->datalen == 0)
+				continue;
+
+			memcpy(wdev->u.client.ssid, ssid->data, ssid->datalen);
+			wdev->u.client.ssid_len = ssid->datalen;
+			break;
+		}
+		rcu_read_unlock();
+	}
+
 	return;
 out:
 	for_each_valid_link(cr, link)
--
2.39.2