Fix the 'scan hang' issue.

When requesting a scan and one is already in progess, e.g. while in scan
state, we happily wait for a scan done notification. Though, this
notification might never be sent, e.g. if we are trying to find a network
to associate to and there is none. Instead of always waiting for a
notification just do so if a new scan has been started. For both cases the
scan cache is used to report available networks even if the content might
not be fresh.

MFC after:	1 month

1 files changed, 6 insertions, 2 deletions

diff --git a/sbin/ifconfig/ifieee80211.c b/sbin/ifconfig/ifieee80211.c
index 0250f16..2104e0d 100644
--- a/sbin/ifconfig/ifieee80211.c
+++ b/sbin/ifconfig/ifieee80211.c
@@ -3230,8 +3230,12 @@ scan_and_wait(int s)
 
 	ireq.i_data = &sr;
 	ireq.i_len = sizeof(sr);
-	/* NB: only root can trigger a scan so ignore errors */
-	if (ioctl(s, SIOCS80211, &ireq) >= 0) {
+	/*
+	 * NB: only root can trigger a scan so ignore errors. Also ignore
+	 * possible errors from net80211, even if no new scan could be
+	 * started there might still be a valid scan cache.
+	 */
+	if (ioctl(s, SIOCS80211, &ireq) == 0) {
 		char buf[2048];
 		struct if_announcemsghdr *ifan;
 		struct rt_msghdr *rtm;