Unbreak, don't assume we always hold the NET_LOCK

After net/if.c:rev 1.661 ifioctl() doesn't take the net lock any more
around SIOCGIFMEDIA and SIOCSIFMEDIA, which broke cad_ioctl().
The same was already true about SIOCGIFSFFPAGE.  Only release/reacquire
the net lock if warranted.

Input mvs@, ok miod@ mvs@ bluhm@

diff --git a/sys/dev/fdt/if_cad.c b/sys/dev/fdt/if_cad.c
index dfeec94..dfc2735 100644 (file)
--- a/sys/dev/fdt/if_cad.c
+++ b/sys/dev/fdt/if_cad.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: if_cad.c,v 1.11 2022/03/08 16:13:08 visa Exp $        */
+/*     $OpenBSD: if_cad.c,v 1.12 2022/08/14 21:10:08 jca Exp $ */
 
 /*
  * Copyright (c) 2021-2022 Visa Hankala
@@ -550,12 +550,22 @@ cad_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
 {
        struct cad_softc *sc = ifp->if_softc;
        struct ifreq *ifr = (struct ifreq *)data;
-       int error = 0;
+       int error = 0, netlock_held = 1;
        int s;
 
-       NET_UNLOCK();
+       switch (cmd) {
+       case SIOCGIFMEDIA:
+       case SIOCSIFMEDIA:
+       case SIOCGIFSFFPAGE:
+               netlock_held = 0;
+               break;
+       }
+
+       if (netlock_held)
+               NET_UNLOCK();
        rw_enter_write(&sc->sc_cfg_lock);
-       NET_LOCK();
+       if (netlock_held)
+               NET_LOCK();
        s = splnet();
 
        switch (cmd) {