This change enables lockless accesses to bridge rtable lists.
See locking notes in a comment to know how pserialize and
mutexes are used. Some functions are rearranged to use
pserialize. A workqueue is introduced to use pserialize in
bridge_rtage via bridge_timer callout.
As usual, pserialize and mutexes are used only when NET_MPSAFE
on. On the other hand, the newly added workqueue is used
regardless of NET_MPSAFE on or off.
This change enables lockless accesses to bridge member lists.
See locking notes in a comment to know how pserialize and
mutexes are used.
This change also provides support for softint-based interrupt
handling; pserialize readers can run in both HW interrupt and
softint contexts.
As usual, pserialize is used only when NET_MPSAFE on.
- Introduce BRIDGE_MPSAFE
- It's enabled only when NET_MPSAFE is defined
in if.h or the kernel config
- Add iflist and rtlist mutex locks
- Locking iflist is performance sensitive,
so it's not used when !BRIDGE_MPSAFE
- Add bif object reference counting
- It enables fine-grain locking for bridge member lists
by allowing to not hold a lock during touching a bif
- bridge_release_member is added to decrement the
reference count
- A condition variable is added to do bridge_delete_member
gracefully
- Add if_bridgeif to ifnet
- It's a shortcut to a bif object of a bridge member
- It reduces a bif lookup cost and so lock contention on iflist
- Make bridgestp MPSAFE too
The network stack of NetBSD is well organized and
layered. A packet reception is processed from a
lower layer to an upper layer one by one. However,
ether_input and bridge_input are not structured so.
bridge_input is called inside ether_input.
The new structure replaces ifnet#if_input of a bridge
member with bridge_input when the member is attached.
So a packet goes straight on a packet reception via
a bridge, bridge_input => ether_input => ip_input.
The change is part of a patch of Lloyd Parkes submitted
in PR 48104. Unlike the patch, the change doesn't
intend to change the behavior of the packet processing.
Another patch will fix PR 48104.
negative after the timer expired until the entry is deleted.
make it signed, so that we don't get output like
"00:1b:78:12:50:46 wm0 18446744073709551349 flags=0<>"
context (reported on various mailing-lists, and part of PR kern/41114,
causing panic in pf(4) and possibly ipf(4) when BRIDGE_IPF is used).
Defer bridge_forward() to a software interrupt; bridge_input() enqueues
mbufs to ifp->if_snd which is handled in bridge_forward().
* A sign extension error creating the bridge ID corrupted the
priority (always making it the maximum).
* Do not catch STP packets on an interface for which STP is not
enabled -- it's a violation of the spec, and causes STP to fail on
neighboring bridges.
* An optimization to bstp_input() -- some information is already
known when we call it.
contributed anonymously.
parentheses in return statements.
Cosmetic: don't open-code TAILQ_FOREACH().
Cosmetic: change types of variables to avoid oodles of casts: in
in6_src.c, avoid casts by changing several route_in6 pointers
to struct route pointers. Remove unnecessary casts to caddr_t
elsewhere.
Pave the way for eliminating address family-specific route caches:
soon, struct route will not embed a sockaddr, but it will hold
a reference to an external sockaddr, instead. We will set the
destination sockaddr using rtcache_setdst(). (I created a stub
for it, but it isn't used anywhere, yet.) rtcache_free() will
free the sockaddr. I have extracted from rtcache_free() a helper
subroutine, rtcache_clear(). rtcache_clear() will "forget" a
cached route, but it will not forget the destination by releasing
the sockaddr. I use rtcache_clear() instead of rtcache_free()
in rtcache_update(), because rtcache_update() is not supposed
to forget the destination.
Constify:
1 Introduce const accessor for route->ro_dst, rtcache_getdst().
2 Constify the 'dst' argument to ifnet->if_output(). This
led me to constify a lot of code called by output routines.
3 Constify the sockaddr argument to protosw->pr_ctlinput. This
led me to constify a lot of code called by ctlinput routines.
4 Introduce const macros for converting from a generic sockaddr
to family-specific sockaddrs, e.g., sockaddr_in: satocsin6,
satocsin, et cetera.
- initialise stp when the bridge is turned up, without this stp will keep
all interfaces disabled in a sequence like:
brconfig bridge0 add if0 add if1 stp if0 stp if1 up
- s/BRDGSPRI/BRDGSIFPRIO in brconfig.c:cmd_ifpriority()
add a command (ifpathcost) to change the stp path cost of the STP path cost of
an interface. Display the interface path cost with the others STP parameters.
compile-time by BRIDGE_IPF, and at runtime by brconfig with the {ipf,-ipf}
option on a per-bridge basis.
As a side-effect, add PFIL_HOOKS processing to if_bridge.
ozaki-r