Thanks for the pointers; updated diff below to set the MAC in
bwfm_init() if preinit has already run.
Works on boot with "lladdr random" as the first line in hostname.bwfm0,
and also changing the lladdr after boot with ifconfig.
diff /usr/src
commit - 6c24eb55e021991196003dc7f0a643e806b14295
path + /usr/src
blob - dfa7a1973d2ab6be7e4b2fbd869b38c441d4eae0
file + sys/dev/ic/bwfm.c
--- sys/dev/ic/bwfm.c
+++ sys/dev/ic/bwfm.c
@@ -451,6 +451,16 @@ bwfm_init(struct ifnet *ifp)
return;
}
sc->sc_initialized = 1;
+ } else {
+ /* Update MAC in case the upper layers changed it. */
+ IEEE80211_ADDR_COPY(ic->ic_myaddr,
+ ((struct arpcom *)ifp)->ac_enaddr);
+ if (bwfm_fwvar_var_set_data(sc, "cur_etheraddr",
+ ic->ic_myaddr, sizeof(ic->ic_myaddr))) {
+ printf("%s: could not write MAC address\n",
+ DEVNAME(sc));
+ return;
+ }
}
/* Select default channel */
"Theo de Raadt" <dera...@openbsd.org> writes:
> Yes, the normal pattern is to update the driver soft state, and
> then do perform a backside "down / up" transition.
>
> Stefan Sperling <s...@stsp.name> wrote:
>
>> On Sat, Feb 17, 2024 at 06:27:40PM -1000, Todd Carson wrote:
>> >
>> > On a Raspberry Pi 4 running a recent snapshot, I found that the built-in
>> > bwfm interface would fail to receive non-broadcast traffic after
>> > changing the MAC address with ifconfig (for example by having
>> > "lladdr random" in hostname.bwfm0).
>> >
>> > It looks like this was happening because the new MAC address was set in
>> > the kernel network stack but the bwfm driver wasn't doing anything
>> > to write the address to the device.
>> >
>> > The below diff fixes it for me.
>> > I don't have any other bwfm devices to test.
>>
>> An alternative approach is to memcpy the stack's MAC into ic_myaddr
>> whenever the interface comes up. E.g. iwx does this in iwx_preinit():
>>
>> if (sc->attached) {
>> /* Update MAC in case the upper layers changed it. */
>> IEEE80211_ADDR_COPY(sc->sc_ic.ic_myaddr,
>> ((struct arpcom *)ifp)->ac_enaddr);
>> return 0;
>> }
>>
>> This way the new value of ic_myaddr is propagated to firmware as
>> part of the usual startup process.
>>
>> A possible problem with your approach is that the bwfm_fwvar_set_data()
>> call might occur while the interface is still down and no firmware has
>> been loaded. It looks like you handle this case by returning EIO, which
>> means a hostname.bwfm0 file like the following would run into this I/O
>> error on the first line during boot:
>>
>> lladdr random
>> nwid foo wpakey bar
>> inet autoconf
>>
>> With the approach taken by iwx(4) such files will work without errors
>> and the random MAC will be set in the stack only at first, while being
>> passed to the device when hardware comes up.
>>
