[PATCH] iwinfo: nl80211: fix wpa supplicant ctrl socket permissions

[Andre Heider]

No data at all can currently be read from the control socket.
Set up the permission exactly like hostapd's wpa_cli utility to fix it.

Among other this fixes a mesh's encryption being shown as "None".

Signed-off-by: Andre Heider <a.heider at gmail.com>
---
 iwinfo_nl80211.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/iwinfo_nl80211.c b/iwinfo_nl80211.c
index aa92382..77fddee 100644
--- a/iwinfo_nl80211.c
+++ b/iwinfo_nl80211.c
@@ -938,6 +938,18 @@ static int nl80211_wpactl_connect(const char *ifname, struct sockaddr_un *local)
 		sprintf(remote.sun_path, "/var/run/wpa_supplicant-%s/%s",
 		        ifname, ifname);
 
+	/* Set client socket file permissions so that bind() creates the client
+	* socket with these permissions and there is no need to try to change
+	* them with chmod() after bind() which would have potential issues with
+	* race conditions. These permissions are needed to make sure the server
+	* side (wpa_supplicant or hostapd) can reply to the control interface
+	* messages.
+	*
+	* The lchown() calls below after bind() are also part of the needed
+	* operations to allow the response to go through. Those are using the
+	* no-deference-symlinks version to avoid races. */
+	fchmod(sock, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
+
 	if (fcntl(sock, F_SETFD, fcntl(sock, F_GETFD) | FD_CLOEXEC) < 0)
 	{
 		close(sock);
@@ -966,6 +978,10 @@ static int nl80211_wpactl_connect(const char *ifname, struct sockaddr_un *local)
 		return -1;
 	}
 
+	/* Set group even if we do not have privileges to change owner */
+	lchown(local->sun_path, -1, 101);
+	lchown(local->sun_path, 101, 101);
+
 	return sock;
 }
 
-- 
2.35.1