Changing WEP keys without resetting the NIC

[Matthew R. Dempsky]

I just hacked the FreeBSD backend of wpa_supplicant enough to connect
my OpenBSD laptop to my university's wireless network (just Dynamic
WEP, not TKIP or CCMP).  I also had to add an ugly hack to
dev/ic/rt2560.c to ignore ENETRESET when issuing a SIOCS80211NWKEY
ioctl(2) (see below).

The patch works for my needs, but I'm not familiar enough with 802.11
to know if there are any cases where changing a WEP key necessitates a
reset.

Would it be better if the no-reset behavior had to be explicitly
requested in the ioctl(2)?  (I was thinking perhaps adding an extra
IEEE80211_C_DYNAMICWEP capability bit for devices to provide, and
changing ieee80211_ioctl to check for this capability and to return a
different value if i_wepon has a IEEE80211_NWKEY_DYNAMIC bit set.)

Thanks.

--- dev/ic/rt2560.c~    Sat Sep  2 09:18:46 2006
+++ dev/ic/rt2560.c     Sat Sep  2 09:19:13 2006
@@ -2153,6 +2153,13 @@
                }
                break;
 
+       case SIOCS80211NWKEY:
+               /* Allow key changes without resetting. */
+               error = ieee80211_ioctl(ifp, cmd, data);
+               if (error == ENETRESET)
+                       error = 0;
+               break;
+
        default:
                error = ieee80211_ioctl(ifp, cmd, data);
        }