llentry#la_opaque which is for token ring is allocated in arp.c
and freed in arp.c when freeing llentry. However, llentry can be
freed from other places, e.g., lltable_free. In such cases,
la_opaque is never freed.
To fix that, add a new callback (lle_ll_free) to llentry and
register a destruction function of la_opque to it. On freeing a
llentry, we can surely free la_opque via the callback.
lltable and llentry were introduced to replace ARP cache data structure
for further restructuring of the routing table: L2 nexthop cache
separation. This change replaces the NDP cache data structure
(llinfo_nd6) with them as well as ARP.
One noticeable change is for neighbor cache GC mechanism that was
introduced to prevent IPv6 DoS attacks. net.inet6.ip6.neighborgcthresh
was the max number of caches that we store in the system. After
introducing lltable/llentry, the value is changed to be per-interface
basis because lltable/llentry stores neighbor caches in each interface
separately. And the change brings one degradation; the old GC mechanism
dropped exceeded packets based on LRU while the new implementation drops
packets in order from the beginning of lltable (a hash table + linked
lists). It would be improved in the future.
Added functions in in6.c come from FreeBSD (as of r286629) and are
tweaked for NetBSD.
Proposed on tech-kern and tech-net.
Using softnet_lock for mutual exclusion between lltable_free and
arptimer was wrong and had an issue causing a deadlock between
them; lltable_free waits arptimer completion by calling
callout_halt with softnet_lock that is held in arptimer, however
lltable_free also holds llentry's lock that is also held in
arptimer so arptimer never obtain the lock and both never go
forward eventually. We have to pass llentry's lock to
callout_halt instead.
modular/filesystem. In the non-modular case we initialize through attach.
In the modular/builtin case we define the module to be class misc so it
attaches late (after percpu is initialized) since driver modules attach
too early. In the modular/filesystem case we define it to be a driver
module since we autoload it via /dev/npf open.
are initialized. MODULE_CLASS_DRIVER modules are now initialized before
autoconfiguration starts, but npf_init has a dependency on percpu(9) which
doesn't work until CPUs have attached (at least on ARM).
Callers of arpresolve() now pass the error code back to their caller,
masking out EWOULDBLOCK.
This allows applications such as ping(8) to display a suitable error
condition.
In it's place, use rtrequest1() inside rt_ifa_addlocal() and
rtdeletemsg() inside rt_ifa_remlocal().
This removes the need for INET/INET6 specific code and allows
greater control over the creation of the local address route.
Currently RX can run on a CPU other than CPU#0, so always enqueuing
to a pktqueue of CPU#0 makes no sense. Let's use a curcpu's pktqueue,
although bridge_foward softint doesn't run in parallel without
NET_MPSAFE.
This is a temporal solution. We need a fundamental solution.
With GATEWAY (fastforward), the whole forwarding processing runs in
hardware interrupt context. So we cannot use rwlock for lltable and
llentry in that case.
This change replaces rwlock with mutex(IPL_NET) for lltable and llentry
when GATEWAY is enabled. We need to tweak locking only around rtree
in lltable_free. Other than that, what we need to do is to change macros
for locks.
I hope fastforward runs in softint some day in the future...
The previous code took locks the following order:
- LLE_WLOCKs
- mutex_enter(softnet_lock)
- LLE_WUNLOCKs
- mutex_exit(softnet_lock)
This fix moves mutex_enter(softnet_lock) before LLE_WLOCKs.
