Capsicum did not prevent certain privileged networking operations,
specifically creation of raw sockets and network configuration ioctls.
However, these facilities can be used to circumvent some of the
restrictions that capability mode is supposed to enforce.
Add capability mode checks to disallow network configuration ioctls and
creation of sockets other than PF_LOCAL and SOCK_DGRAM/STREAM/SEQPACKET
internet sockets.
Reviewed by: oshogbo
Discussed with: emaste
Reported by: manu
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D29423
* device_printf() is effectively a printf
* if_printf() is effectively a LOG_INFO
This allows subsystems to log device/netif stuff using different log levels,
rather than having to invent their own way to prefix unit/netif names.
Differential Revision: https://reviews.freebsd.org/D29320
Reviewed by: imp
Drain the callbacks upon if_deregister_com_alloc() such that the
if_com_free[type] won't be nullified before if_destroy().
Taking fwip(4) as an example, before this fix, kldunload if_fwip will
go through the following:
1. fwip_detach()
2. if_free() -> schedule if_destroy() through NET_EPOCH_CALL
3. fwip_detach() returns
4. firewire_modevent(MOD_UNLOAD) -> if_deregister_com_alloc()
5. kernel complains about:
Warning: memory type fw_com leaked memory on destroy (1 allocations, 64 bytes leaked).
6. EPOCH runs if_destroy() -> if_free_internal()i
By this time, if_com_free[if_alloctype] is NULL since it's already
nullified by if_deregister_com_alloc(); hence, firewire_free() won't
have a chance to release the allocated fw_com.
Reviewed by: hselasky, glebius
MFC after: 2 weeks
When we have an ifp pointer and the code is running inside epoch,
epoch guarantees the pointer will not be freed.
However, the following case can still happen:
* in thread 1 we drop to refcount=0 for ifp and schedule its deletion.
* in thread 2 we use this ifp and reference it
* destroy callout kicks in
* unhappy user reports a bug
This can happen with the current implementation of ifnet_byindex_ref(),
as we're not holding any locks preventing ifnet deletion by a parallel thread.
To address it, add if_try_ref(), allowing to return failure when
referencing ifp with refcount=0.
Additionally, enforce existing if_ref() is with KASSERT to provide a
cleaner error in such scenarios.
Finally, fix ifnet_byindex_ref() by using if_try_ref() and returning NULL
if the latter fails.
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D28836
More and more code migrates from lock-based protection to the NET_EPOCH
umbrella. It requires some logic changes, including, notably, refcount
handling.
When we have an `ifa` pointer and we're running inside epoch we're
guaranteed that this pointer will not be freed.
However, the following case can still happen:
* in thread 1 we drop to 0 refcount for ifa and schedule its deletion.
* in thread 2 we use this ifa and reference it
* destroy callout kicks in
* unhappy user reports bug
To address it, new `ifa_try_ref()` function is added, allowing to return
failure when we try to reference `ifa` with 0 refcount.
Additionally, existing `ifa_ref()` is enforced with `KASSERT` to provide
cleaner error in such scenarious.
Reviewed By: rstone, donner
Differential Revision: https://reviews.freebsd.org/D28639
MFC after: 1 week
Widen the ifnet_detach_sxlock to cover the entire vnet sysuninit code.
This ensures that we can't end up having the vnet_sysuninit free the UDP
pcb while the detach code is running and trying to purge the UDP pcb.
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D28530
it gets unused.
Currently if_purgeifaddrs() uses in6_purgeaddr() to remove IPv6
ifaddrs. in6_purgeaddr() does not trrigger prefix removal if
number of linked ifas goes to 0, as this is a low-level function.
As a result, if_purgeifaddrs() purges all IPv4/IPv6 addresses but
keeps corresponding IPv6 prefixes.
Fix this by creating higher-level wrapper which handles unused
prefix usecase and use it in if_purgeifaddrs().
Differential revision: https://reviews.freebsd.org/D28128
Revert the mitigation code for the vnet/epair cleanup race (done in r365457).
r368237 introduced a more reliable fix.
MFC after: 2 weeks
Sponsored by: Modirum MDPay
When destroying a vnet and an epair (with one end in the vnet) we often
panicked. This was the result of the destruction of the epair, which destroys
both ends simultaneously, happening while vnet_if_return() was moving the
struct ifnet to its home vnet. This can result in a freed ifnet being re-added
to the home vnet V_ifnet list. That in turn panics the next time the ifnet is
used.
Prevent this race by ensuring that vnet_if_return() cannot run at the same time
as if_detach() or epair_clone_destroy().
PR: 238870, 234985, 244703, 250870
MFC after: 2 weeks
Sponsored by: Modirum MDPay
Differential Revision: https://reviews.freebsd.org/D27378
Replace MAXPHYS by runtime variable maxphys. It is initialized from
MAXPHYS by default, but can be also adjusted with the tunable kern.maxphys.
Make b_pages[] array in struct buf flexible. Size b_pages[] for buffer
cache buffers exactly to atop(maxbcachebuf) (currently it is sized to
atop(MAXPHYS)), and b_pages[] for pbufs is sized to atop(maxphys) + 1.
The +1 for pbufs allow several pbuf consumers, among them vmapbuf(),
to use unaligned buffers still sized to maxphys, esp. when such
buffers come from userspace (*). Overall, we save significant amount
of otherwise wasted memory in b_pages[] for buffer cache buffers,
while bumping MAXPHYS to desired high value.
Eliminate all direct uses of the MAXPHYS constant in kernel and driver
sources, except a place which initialize maxphys. Some random (and
arguably weird) uses of MAXPHYS, e.g. in linuxolator, are converted
straight. Some drivers, which use MAXPHYS to size embeded structures,
get private MAXPHYS-like constant; their convertion is out of scope
for this work.
Changes to cam/, dev/ahci, dev/ata, dev/mpr, dev/mpt, dev/mvs,
dev/siis, where either submitted by, or based on changes by mav.
Suggested by: mav (*)
Reviewed by: imp, mav, imp, mckusick, scottl (intermediate versions)
Tested by: pho
Sponsored by: The FreeBSD Foundation
Differential revision: https://reviews.freebsd.org/D27225
When we terminate a vnet (i.e. jail) we move interfaces back to their home
vnet. We need to protect our access to the V_ifnet CK_LIST.
We could enter NET_EPOCH, but if_detach_internal() (called from if_vmove())
waits for net epoch callback completion. That's not possible from NET_EPOCH.
Instead, we take the IFNET_WLOCK, build a list of the interfaces that need to
move and, once we've released the lock, move them back to their home vnet.
We cannot hold the IFNET_WLOCK() during if_vmove(), because that results in a
LOR between ifnet_sx, in_multi_sx and iflib ctx lock.
Separate out moving the ifp into or out of V_ifnet, so we can hold the lock as
we do the list manipulation, but do not hold it as we if_vmove().
Reviewed by: melifaro
MFC after: 2 weeks
Sponsored by: Modirum MDPay
Differential Revision: https://reviews.freebsd.org/D27279
It no longer serves any purpose, as evidenced by the fact that we never take it
without ifnet_sxlock.
Sponsored by: Modirum MDPay
Differential Revision: https://reviews.freebsd.org/D27278
For interfaces that do not support SIOCGIFMEDIA (for which there are
quite a few) the only fallback is to query the interface for
if_data->ifi_link_state. While it's possible to get at if_data for an
interface via getifaddrs(3) or sysctl, both are heavy weight mechanisms.
SIOCGIFDATA is a simple ioctl to retrieve this fast with very little
resource use in comparison. This implementation mirrors that of other
similar ioctls in FreeBSD.
Submitted by: Roy Marples <roy@marples.name>
Reviewed by: markj
MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D26538
There's a race where dying vnets move their interfaces back to their original
vnet, and if_epair cleanup (where deleting one interface also deletes the other
end of the epair). This is commonly triggered by the pf tests, but also by
cleanup of vnet jails.
As we've not yet been able to fix the root cause of the issue work around the
panic by not dereferencing a NULL softc in epair_qflush() and by not
re-attaching DYING interfaces.
This isn't a full fix, but makes a very common panic far less likely.
PR: 244703, 238870
Reviewed by: lutz_donnerhacke.de
MFC after: 4 days
Differential Revision: https://reviews.freebsd.org/D26324
These functions were introduced before UMA started ensuring that freed
memory gets placed in domain-local caches. They no longer serve any
purpose since UMA now provides their functionality by default. Remove
them to simplyify the kernel memory allocator interfaces a bit.
Reviewed by: cem, kib
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D25937
Remove all variations of rtrequest <rtrequest1_fib, rtrequest_fib,
in6_rtrequest, rtrequest_fib> and their uses and switch to
to rib_action(). This is part of the new routing KPI.
Submitted by: Neel Chauhan <neel AT neelc DOT org>
Differential Revision: https://reviews.freebsd.org/D25546
Remove all variations of rtrequest <rtrequest1_fib, rtrequest_fib,
in6_rtrequest, rtrequest_fib> and their uses and switch to
to rib_action(). This is part of the new routing KPI.
Submitted by: Neel Chauhan <neel AT neelc DOT org>
Differential Revision: https://reviews.freebsd.org/D25546
Currently the only reason of refcounting rtentries is the need to report
the rtable operation details immediately after the execution.
Delaying rtentry reclamation allows to stop refcounting and simplify the code.
Additionally, this change allows to reimplement rib_lookup_info(), which
is used by some of the customers to get the matching prefix along
with nexthops, in more efficient way.
The change keeps per-vnet rtzone uma zone. It adds nh_vnet field to
nhop_priv to be able to reliably set curvnet even during vnet teardown.
Rest of the reference counting code will be removed in the D24867 .
Differential Revision: https://reviews.freebsd.org/D24866
r357614 added CTLFLAG_NEEDGIANT to make it easier to find nodes that are
still not MPSAFE (or already are but aren’t properly marked).
Use it in preparation for a general review of all nodes.
This is non-functional change that adds annotations to SYSCTL_NODE and
SYSCTL_PROC nodes using one of the soon-to-be-required flags.
Mark all obvious cases as MPSAFE. All entries that haven't been marked
as MPSAFE before are by default marked as NEEDGIANT
Approved by: kib (mentor, blanket)
Commented by: kib, gallatin, melifaro
Differential Revision: https://reviews.freebsd.org/D23718
switch over to opt-in instead of opt-out for epoch.
Instead of IFF_NEEDSEPOCH, provide IFF_KNOWSEPOCH. If driver marks
itself with IFF_KNOWSEPOCH, then ether_input() would not enter epoch
when processing its packets.
Now this will create recursive entrance in epoch in >90% network
drivers, but will guarantee safeness of the transition.
Mark several tested drivers as IFF_KNOWSEPOCH.
Reviewed by: hselasky, jeff, bz, gallatin
Differential Revision: https://reviews.freebsd.org/D23674
Revert parts of r353274 replacing vnet_state with a shutdown flag.
Not having the state flag for the current SI_SUB_* makes it harder to debug
kernel or module panics related to VNET bringup or teardown.
Not having the state also does not allow us to check for other dependency
levels between components, e.g. for moving interfaces.
Expand the VNET structure with the new boolean flag indicating that we are
doing a shutdown of a given vnet and update the vnet magic cookie for the
change.
Update libkvm to compile with a bool in the kernel struct.
Bump __FreeBSD_version for (external) module builds to more easily detect
the change.
Reviewed by: hselasky
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D23097
Recent network epoch changes have left some drivers unexpectedly broken
and there is not yet a consensus on the correct fix. This is patch is
a minor performance impact until we can agree on the correct path
forward.
Reviewed by: core, network, imp, glebius, hselasky
Differential Revision: https://reviews.freebsd.org/D23515
Correction after r333476:
- write this as LOG_DEBUG again instead of LOG_INFO;
- get back function name into the message;
- error may be ESRCH if an address is removed in process (by carp f.e.),
not only ENOENT;
- expression complexity grows, so try making it more readable.
MFC after: 1 week
subsystems tend to need to know about it, and including if_var.h is
huge header pollution for them. Polluting possible non-network
users with single symbol seems much lesser evil.
- Remove non-preemptible network epoch. Not used yet, and unlikely
to get used in close future.
if_vmove can fail if it lost a race and the vnet's already been moved. The
callers (and their callers) can generally cope with this, but right now
success is assumed. Plumb out the ENOENT from if_detach_internal if it
happens so that the error's properly reported to userland.
Reviewed by: bz, kp
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D22780
Fix some style in if_addgroup(). No functional change intended.
Reviewed by: hselasky
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D22892
r297816 added some bpf magic for VIMAGE unconditionally which no longer
allows kernels to compile without bpf (but with other networking).
Add the missing ifdef checks and allow a kernel to compile without bpf
again.
PR: 242136
Reported by: dave mischler.com
MFC after: 2 weeks
Add explicit SI_SUB_EPOCH, after SI_SUB_TASKQ and before SI_SUB_SMP
(EARLY_AP_STARTUP). Rename existing "SI_SUB_TASKQ + 1" to SI_SUB_EPOCH.
epoch(9) consumers cannot epoch_alloc() before SI_SUB_EPOCH:SI_ORDER_SECOND,
but likely should allocate before SI_SUB_SMP. Prior to this change,
consumers (well, epoch itself, and net/if.c) just open-coded the
SI_SUB_TASKQ + 1 order to match epoch.c, but this was fragile.
Reviewed by: mmacy
Differential Revision: https://reviews.freebsd.org/D22503
and IPv6. With IPv6 we may call if_addmulti() in context of processing
of an incoming packet. Usually this is interrupt context. While most
of the NIC drivers are able to reprogram multicast filters without
sleeping, some of them can't. An example is e1000 family of drivers.
With iflib conversion the problem was somewhat hidden. Iflib processes
packets in private taskqueue, so going to sleep doesn't trigger an
assertion. However, the sleep would block operation of the driver and
following incoming packets would fill the ring and eventually would
start being dropped. Enabling epoch for the full time of a packet
processing again started to trigger assertions for e1000.
Fix this problem once and for all using a general taskqueue to call
if_ioctl() method in all cases when if_addmulti() is called in a
non sleeping context. Note that nobody cares about returned value.
Reviewed by: hselasky, kib
Differential Revision: https://reviews.freebsd.org/D22154
Debugnet is a simplistic and specialized panic- or debug-time reliable
datagram transport. It can drive a single connection at a time and is
currently unidirectional (debug/panic machine transmit to remote server
only).
It is mostly a verbatim code lift from netdump(4). Netdump(4) remains
the only consumer (until the rest of this patch series lands).
The INET-specific logic has been extracted somewhat more thoroughly than
previously in netdump(4), into debugnet_inet.c. UDP-layer logic and up, as
much as possible as is protocol-independent, remains in debugnet.c. The
separation is not perfect and future improvement is welcome. Supporting
INET6 is a long-term goal.
Much of the diff is "gratuitous" renaming from 'netdump_' or 'nd_' to
'debugnet_' or 'dn_' -- sorry. I thought keeping the netdump name on the
generic module would be more confusing than the refactoring.
The only functional change here is the mbuf allocation / tracking. Instead
of initiating solely on netdump-configured interface(s) at dumpon(8)
configuration time, we watch for any debugnet-enabled NIC for link
activation and query it for mbuf parameters at that time. If they exceed
the existing high-water mark allocation, we re-allocate and track the new
high-water mark. Otherwise, we leave the pre-panic mbuf allocation alone.
In a future patch in this series, this will allow initiating netdump from
panic ddb(4) without pre-panic configuration.
No other functional change intended.
Reviewed by: markj (earlier version)
Some discussion with: emaste, jhb
Objection from: marius
Differential Revision: https://reviews.freebsd.org/D21421
general is allowed to sleep. Don't enter the epoch for the
whole duration. If some event handlers need the epoch, they
should handle that theirselves.
Discussed with: hselasky
same after the network stack was epochified. Merge the two into one function
and cleanup all uses of ifnet_byindex_locked().
While at it:
- Add branch prediction macros.
- Make sure the ifnet pointer is only deferred once,
also when code optimisation is disabled.
Sponsored by: Mellanox Technologies
This fixes the following assert when "options RATELIMIT" is used:
panic()
malloc()
sysctl_add_oid()
tcp_rl_ifnet_link()
do_link_state_change()
taskqueue_run_locked()
Sponsored by: Mellanox Technologies
on interface. Such function could been implemented on top of
the if_foreach_llm?addr(), but several drivers need counting,
so avoid copy-n-paste inside the drivers.
addresses. The KPI doesn't reveal neither how addresses are stored,
how the access to them is synchronized, neither reveal struct ifaddr
and struct ifmaddr.
Reviewed by: gallatin, erj, hselasky, philip, stevek
Differential Revision: https://reviews.freebsd.org/D21943
protected by IF_ADDR_LOCK(), which was a mutex, so that two simultaneous
if_setlladdr() can't execute. Later it was switched to IF_ADDR_RLOCK(),
likely by a mistake. Later it was switched to NET_EPOCH_ENTER(). Then I
incorrectly added NET_EPOCH_ASSERT() here.
In reality ifp->if_addr never goes away and never changes its length. So,
doing bcopy() in it is always "safe", meaning it won't dereference a wrong
pointer or write into someone's else memory. Of course doing two bcopy() in
parallel would result in a mess of two addresses, but net epoch doesn't
protect against that, neither IF_ADDR_RLOCK() did.
So for now, just remove the assertion and leave for later a proper fix.
Reported by: markj
When epoch(9) was introduced to network stack, it was basically
dropped in place of existing locking, which was mutexes and
rwlocks. For the sake of performance mutex covered areas were
as small as possible, so became epoch covered areas.
However, epoch doesn't introduce any contention, it just delays
memory reclaim. So, there is no point to minimise epoch covered
areas in sense of performance. Meanwhile entering/exiting epoch
also has non-zero CPU usage, so doing this less often is a win.
Not the least is also code maintainability. In the new paradigm
we can assume that at any stage of processing a packet, we are
inside network epoch. This makes coding both input and output
path way easier.
On output path we already enter epoch quite early - in the
ip_output(), in the ip6_output().
This patch does the same for the input path. All ISR processing,
network related callouts, other ways of packet injection to the
network stack shall be performed in net_epoch. Any leaf function
that walks network configuration now asserts epoch.
Tricky part is configuration code paths - ioctls, sysctls. They
also call into leaf functions, so some need to be changed.
This patch would introduce more epoch recursions (see EPOCH_TRACE)
than we had before. They will be cleaned up separately, as several
of them aren't trivial. Note, that unlike a lock recursion the
epoch recursion is safe and just wastes a bit of resources.
Reviewed by: gallatin, hselasky, cy, adrian, kristof
Differential Revision: https://reviews.freebsd.org/D19111
