| Age | Commit message (Collapse) | Author |
|
Use correct scope for IPv6.
|
|
from the virtual MAC address, which confuses switches.
|
|
|
|
|
|
These were originally made failable back in 2017 when if_initialize
allocated a softint in every interface for link state changes, so
that it could fail gracefully instead of panicking:
https://mail-index.NetBSD.org/source-changes/2017/10/23/msg089053.html
However, this spawned many seldom- or never-tested error branches,
which are risky to have around. And that softint in every interface
has since been replaced by a single global workqueue, because link
state changes require thread context but not low latency or high
throughput:
https://mail-index.NetBSD.org/source-changes/2020/02/06/msg113759.html
So there is no longer any reason for if_initialize to fail. (The
subroutine if_stats_init can't fail because percpu_alloc can't fail
either.)
There is a snag: the softint_establish in if_percpuq_create could
fail, potentially leading to bad consequences later on trying to use
the softint. This change doesn't introduce any new bugs because of
the snag -- if_percpuq_attach was already broken. However, the snag
can be better addressed without spawning error branches, either by
using a single softint or making softints less scarce.
(Separate commit will change the signatures of if_attach and
if_initialize to return void, scheduled to ride whatever is the next
convenient kernel bump.)
Patch and testing on amd64 and evbmips64-eb by maya@; commit message
soliloquy, and compile-testing on evbppc/i386/earmv7hf, by me.
|
|
Link level address for carp is dervied from vhid.
Until vhid is set, carp is useless, so don't give it a link level address
until a vhid is set.
This fixes recent test case breakage where carp was fixed to actually
print the ethernet address set by default. Note that neither carp nor
the test case itself was actually broken as the error is the common
ATF net code assuming that a cloned interface's link level address is
unique upon creation.
|
|
This is consitent with other BSD's handling of CARP and means
we don't have to carry a custom flag for it.
|
|
Otherwise ifconfig reports SIOCGLIFADDR errors.
|
|
carp literally has no media just like ppp, vlan, etc.
|
|
softint.
|
|
|
|
|
|
|
|
|
|
Add link0 (IFF_LINK0) flag to map INIT state to LINK_STATE_DOWN
instead of LINK_STATE_UNKNOWN. This allows routing software to
suppress routes to the interface of the carp interface when in
init state (e. g. link down in the parent interface).
|
|
and remove code to handle failures that can no longer happen.
|
|
|
|
|
|
|
|
|
|
compatibility with BIOC[GS]SEESENT ioctl. The userland interface is the same
as FreeBSD.
This change also fixes a bug that the direction is misunderstand on some
environment by passing the direction to bpf_mtap*() instead of checking
m->m_pkthdr.rcvif.
|
|
The lock is already held while adding and deleting
ok ozaki-r@
|
|
ok ozaki-r@
|
|
|
|
it to void.
|
|
if_link_queue is a queue to store events of link state changes, which is
used to pass events from (typically) an interrupt handler to
if_link_state_change softint. The queue was protected by KERNEL_LOCK so far,
but if IFEF_MPSAFE is enabled, it becomes unsafe because (perhaps) an interrupt
handler of an interface with IFEF_MPSAFE doesn't take KERNEL_LOCK. Protect it
by a spin mutex.
Additionally with this change KERNEL_LOCK of if_link_state_change softint is
omitted if NET_MPSAFE is enabled.
Note that the spin mutex is now ifp->if_snd.ifq_lock as well as the case of
if_timer (see the comment).
|
|
|
|
There are already two flags for if_output and if_start, however, it seems such
MPSAFE flags are eventually needed for all if_XXX operations. Having discrete
flags for each operation is wasteful of if_extflags bits. So let's unify
the flags into one: IFEF_MPSAFE.
Fortunately IFEF_*_MPSAFE flags have never been included in any releases, so
we can change them without breaking backward compatibility of the releases
(though the kernel version of -current should be bumped).
Note that if an interface have both MP-safe and non-MP-safe operations at a
time, we have to set the IFEF_MPSAFE flag and let callees of non-MP-safe
opeartions take the kernel lock.
Proposed on tech-kern@ and tech-net@
|
|
|
|
If the handler is delayed because of the indirection call via softint,
some operations are executed in reverse and may cause unexpected
behaviors. For example, due to the issue a GARP packet wasn't sent on
a transition from the BACKUP state to the MASTER state; this happened
because IN_IFF_DETACHED flag wasn't cleared on arpannounce, which
had been cleared in the link_state_change handler.
This fixes an issue reported by sborrill@ on tech-net:
http://mail-index.netbsd.org/tech-net/2017/03/14/msg006283.html
|
|
|
|
if_link_state directly.
|
|
|
|
- Provide if_release for consistency to if_acquire
- Use if_acquire and if_release for ifp iterations
- Make ifnet_psref_class static
|
|
It passes ATF tests but no more, no less.
|
|
pr_input is currently called in softint. Some pr_input such as ICMP, ICMPv6
and CARP can add/delete/update IP addresses and routing table entries. For
example, icmp6_redirect_input updates an a routing table entry and
nd6_ra_input may delete an IP address.
Basically such operations shouldn't be done in softint. That aside, we have
a reason to avoid the situation; psz/psref waits cannot be used in softint,
however they are required to work in such pr_input in the MP-safe world.
The change implements the workqueue pr_input framework called wqinput which
provides a means to defer pr_input of a protocol to workqueue easily.
Currently icmp_input, icmp6_input, carp_proto_input and carp6_proto_input
are deferred to workqueue by the framework.
Proposed and discussed on tech-kern and tech-net
|
|
|
|
mpsafe.
Reviewed by ozaki-r@
|
|
carp_clone_destroy calls ether_ifdetach so not calling ether_ifattach is
inconsistent. If we add something pair of initialization and destruction
to ether_ifattach and ether_ifdetach (e.g., mutex_init/mutex_destroy),
ether_ifdetach of carp_clone_destroy won't work. So use ether_ifattach.
In order to do so, make ether_ifattach accept the 2nd argument (lla) as
NULL to allow carp to initialize its link level address by itself.
|
|
See the following descriptions for details.
Proposed on tech-kern and tech-net
Overview
--------
We protect the routing table with a rwock and protect
rtcaches with another rwlock. Each rtentry is protected
from being freed or updated via reference counting and psref.
Global rwlocks
--------------
There are two rwlocks; one for the routing table (rt_lock) and
the other for rtcaches (rtcache_lock). rtcache_lock covers
all existing rtcaches; there may have room for optimizations
(future work).
The locking order is rtcache_lock first and rt_lock is next.
rtentry references
------------------
References to an rtentry is managed with reference counting
and psref. Either of the two mechanisms is used depending on
where a rtentry is obtained. Reference counting is used when
we obtain a rtentry from the routing table directly via
rtalloc1 and rtrequest{,1} while psref is used when we obtain
a rtentry from a rtcache via rtcache_* APIs. In both cases,
a caller can sleep/block with holding an obtained rtentry.
The reasons why we use two different mechanisms are (i) only
using reference counting hurts the performance due to atomic
instructions (rtcache case) (ii) ease of implementation;
applying psref to APIs such rtaloc1 and rtrequest{,1} requires
additional works (adding a local variable and an argument).
We will finally migrate to use only psref but we can do it
when we have a lockless routing table alternative.
Reference counting for rtentry
------------------------------
rt_refcnt now doesn't count permanent references such as for
rt_timers and rtcaches, instead it is used only for temporal
references when obtaining a rtentry via rtalloc1 and rtrequest{,1}.
We can do so because destroying a rtentry always involves
removing references of rt_timers and rtcaches to the rtentry
and we don't need to track such references. This also makes
it easy to wait for readers to release references on deleting
or updating a rtentry, i.e., we can simply wait until the
reference counter is 0 or 1. (If there are permanent references
the counter can be arbitrary.)
rt_ref increments a reference counter of a rtentry and rt_unref
decrements it. rt_ref is called inside APIs (rtalloc1 and
rtrequest{,1} so users don't need to care about it while
users must call rt_unref to an obtained rtentry after using it.
rtfree is removed and we use rt_unref and rt_free instead.
rt_unref now just decrements the counter of a given rtentry
and rt_free just tries to destroy a given rtentry.
See the next section for destructions of rtentries by rt_free.
Destructions of rtentries
-------------------------
We destroy a rtentry only when we call rtrequst{,1}(RTM_DELETE);
the original implementation can destroy in any rtfree where it's
the last reference. If we use reference counting or psref, it's
easy to understand if the place that a rtentry is destroyed is
fixed.
rt_free waits for references to a given rtentry to be released
before actually destroying the rtentry. rt_free uses a condition
variable (cv_wait) (and psref_target_destroy for psref) to wait.
Unfortunately rtrequst{,1}(RTM_DELETE) can be called in softint
that we cannot use cv_wait. In that case, we have to defer the
destruction to a workqueue.
rtentry#rt_cv, rtentry#rt_psref and global variables
(see rt_free_global) are added to conduct the procedure.
Updates of rtentries
--------------------
One difficulty to use refcnt/psref instead of rwlock for rtentry
is updates of rtentries. We need an additional mechanism to
prevent readers from seeing inconsistency of a rtentry being
updated.
We introduce RTF_UPDATING flag to rtentries that are updating.
While the flag is set to a rtentry, users cannot acquire the
rtentry. By doing so, we avoid users to see inconsistent
rtentries.
There are two options when a user tries to acquire a rtentry
with the RTF_UPDATING flag; if a user runs in softint context
the user fails to acquire a rtentry (NULL is returned).
Otherwise a user waits until the update completes by waiting
on cv.
The procedure of a updater is simpler to destruction of
a rtentry. Wait on cv (and psref) and after all readers left,
proceed with the update.
Global variables (see rt_update_global) are added to conduct
the procedure.
Currently we apply the mechanism to only RTM_CHANGE in
rtsock.c. We would have to apply other codes. See
"Known issues" section.
psref for rtentry
-----------------
When we obtain a rtentry from a rtcache via rtcache_* APIs,
psref is used to reference to the rtentry.
rtcache_ref acquires a reference to a rtentry with psref
and rtcache_unref releases the reference after using it.
rtcache_ref is called inside rtcache_* APIs and users don't
need to take care of it while users must call rtcache_unref
to release the reference.
struct psref and int bound that is needed for psref is
embedded into struct route. By doing so we don't need to
add local variables and additional argument to APIs.
However this adds another constraint to psref other than
reference counting one's; holding a reference of an rtentry
via a rtcache is allowed by just one caller at the same time.
So we must not acquire a rtentry via a rtcache twice and
avoid a recursive use of a rtcache. And also a rtcache must
be arranged to be used by a LWP/softint at the same time
somehow. For IP forwarding case, we have per-CPU rtcaches
used in softint so the constraint is guaranteed. For a h
rtcache of a PCB case, the constraint is guaranteed by the
solock of each PCB. Any other cases (pf, ipf, stf and ipsec)
are currently guaranteed by only the existence of the global
locks (softnet_lock and/or KERNEL_LOCK). If we've found the
cases that we cannot guarantee the constraint, we would need
to introduce other rtcache APIs that use simple reference
counting.
psref of rtcache is created with IPL_SOFTNET and so rtcache
shouldn't used at an IPL higher than IPL_SOFTNET.
Note that rtcache_free is used to invalidate a given rtcache.
We don't need another care by my change; just keep them as
they are.
Performance impact
------------------
When NET_MPSAFE is disabled the performance drop is 3% while
when it's enabled the drop is increased to 11%. The difference
comes from that currently we don't take any global locks and
don't use psref if NET_MPSAFE is disabled.
We can optimize the performance of the case of NET_MPSAFE
on by reducing lookups of rtcache that uses psref;
currently we do two lookups but we should be able to trim
one of two. This is a future work.
Known issues
------------
There are two known issues to be solved; one is that
a caller of rtrequest(RTM_ADD) may change rtentry (see rtinit).
We need to prevent new references during the update. Or
we may be able to remove the code (perhaps, need more
investigations).
The other is rtredirect that updates a rtentry. We need
to apply our update mechanism, however it's not easy because
rtredirect is called in softint and we cannot apply our
mechanism simply. One solution is to defer rtredirect to
a workqueue but it requires some code restructuring.
|
|
|
|
ARP requests are only send from valid addresses.
|
|
This change makes struct ifaddr and its variants (in_ifaddr and in6_ifaddr)
MP-safe by using pserialize and psref. At this moment, pserialize_perform
and psref_target_destroy are disabled because (1) we don't need them
because of softnet_lock (2) they cause a deadlock because of softnet_lock.
So we'll enable them when we remove softnet_lock in the future.
|
|
help debugging.
|
|
environemnts, not for pure-IPv6 yet. A real fix is still needed.
|
|
As usual, we leave the old list to avoid breaking kvm(3) users.
|
|
Note that we leave the old list just in case; it seems there are some
kvm(3) users accessing the list. We can remove it later if we confirmed
nobody does actually.
|
|
psz and psref will be applied in another commit.
No functional change intended.
|
|
The motivation is the same as the mbuf's rcvif case; avoid having a pointer
of an ifnet object in ip_moptions and ip6_moptions, which is not MP-safe.
ip_moptions and ip6_moptions can be stored in a PCB for inet or inet6
that's life time is different from ifnet one and so an ifnet object can be
disappeared anytime we get it via them. Thus we need to look up an ifnet
object by if_index every time for safe.
|
|
|