ifconfig list scan and card down

[Arnaud Degroote <degroote%NetBSD.org@localhost>]

While trying to port rsu(4) from OpenBSD, I was wondering why ifconfig
list scan does not work at all with my card, and I finally realized that
ifconfig list scan just fails with a silly error message when the card
is not up ("ifconfig: SIOCS80211: Invalid argument") (see

http://nxr.netbsd.org/xref/src/sys/net80211/ieee80211_ioctl.c#ieee80211_setupscan

for code reference).

So I propose that 'ifconfig list scan' automatically up the card if it
is down. See the attached patch. Any objection ?

At minima, we must return a more useful error message to the caller.

diff --git a/sbin/ifconfig/ieee80211.c b/sbin/ifconfig/ieee80211.c
index 1e49c57..da2566e 100644
--- a/sbin/ifconfig/ieee80211.c
+++ b/sbin/ifconfig/ieee80211.c
@@ -463,8 +463,33 @@ setifpowersavesleep(prop_dictionary_t env, 
prop_dictionary_t oenv)
 static int
 scan_exec(prop_dictionary_t env, prop_dictionary_t oenv)
 {
+       struct ifreq ifr;
+       bool must_up_card;
+
+       if (direct_ioctl(env, SIOCGIFFLAGS, &ifr) == -1) {
+               perror("ioctl(SIOCGIFFLAGS");
+               return -1;
+       }
+
+       must_up_card = (ifr.ifr_flags & IFF_UP) == 0;
+       if (must_up_card) {
+               ifr.ifr_flags |= IFF_UP;
+               if (direct_ioctl(env, SIOCSIFFLAGS, &ifr) == -1) {
+                       perror("ioctl(SIOCSIFFLAGS");
+                       return -1;
+               }
+       }
+
        scan_and_wait(env);
        list_scan(env);
+
+       if (must_up_card) {
+               ifr.ifr_flags &= ~IFF_UP;
+               if (direct_ioctl(env, SIOCSIFFLAGS, &ifr) == -1) {
+                       perror("ioctl(SIOCSIFFLAGS");
+                       return -1;
+               }
+       }
        return 0;
 }

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