Save the value of the watchlist pointer at the beginning of the
WATCHLIST_NOTIFY_* macros as if it was a function. This will fix a
frame-xchg.c scenario in which one of the watch callback removes the
frame watch group and the memory where the watchlist pointer was
becomes unallocated but the macro still needs to access it ones or
twice while it destroys the watchlist. Another option would be for
the pointer to be copied in frame-xchg.c itself.
If during WATCHLIST_NOTIFY{,_MATCHES,_NO_ARGS} one of the watch
notify callback triggers a call to watchlist_destroy, give up calling
remaining watches and destroy the watchlist without crashing. This is
useful in frame-xchg.c (P2P use case) where a frame watch may trigger
a move to a new state after receiving a specific frame, and remove one
group of frame watches (including its watchlist) to create a different
group.
All the watchlist notify macros were broken in that they did not check
that the watchlist item was still valid before calling it. This only
came into play when a watchlist was being notified and one of the notify
functions removed an item from the same watchlist. It appears this was
already thought of since watchlist_remove checks 'in_notify' and will
mark the item's id as stale (0), but that id never got checked in the
notify macros.
This fixes testAdHoc valgrind warning:
==3347== Invalid read of size 4
==3347== at 0x416612: eapol_rx_auth_packet (eapol.c:1871)
==3347== by 0x416DD4: __eapol_rx_packet (eapol.c:2334)
==3347== by 0x40725B: netdev_pae_read (netdev.c:3515)
==3347== by 0x440958: io_callback (io.c:123)
==3347== by 0x43FDED: l_main_iterate (main.c:376)
==3347== by 0x43FEAB: l_main_run (main.c:423)
==3347== by 0x40377A: main (main.c:489)
...
In WATCHLIST_NOTIFY_MATCHES pass pointer to the item instead of
item->notify_data to free item->notify_data to be the final watch user's
user_data. This is also what netdev expects.
This can be used to selectively notify watchlist items. The match
function is called for each watchlist_item and match_data is passed
along. If the match function returns true, then the watch_item is
notified. The match function signature and semantics are identical
to l_queue_match_func_t.
