fragmented packets.
When sending IPv4 and IPv6 fragmented packets and a fragment is lost,
the mbuf making up the fragment will remain in the temporary hashed
fragment list for a while. If the network interface departs before the
so-called slow timeout clears the packet, the fragment causes a panic
when the timeout kicks in due to accessing a freed network interface
structure.
Make sure that when a network device is departing, all hashed IPv4 and
IPv6 fragments belonging to it, get freed.
Backtrace:
panic()
icmp6_reflect()
hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim;
^^^^ rcvif->if_afdata[AF_INET6] is NULL.
icmp6_error()
frag6_freef()
frag6_slowtimo()
pfslowtimo()
softclock_call_cc()
softclock()
ithread_loop()
Differential Revision: https://reviews.freebsd.org/D19622
Reviewed by: bz (network), adrian
MFC after: 1 week
Sponsored by: Mellanox Technologies
IPPROTO_IPV6 level socket option IPV6_CHECKSUM enabled and the
checksum check fails, drop the message. Without this fix, an
ICMP6 message was sent indicating a parameter problem.
Thanks to bz@ for suggesting a way to simplify this fix.
Reviewed by: bz@
MFC after: 1 week
Sponsored by: Netflix, Inc.
Differential Revision: https://reviews.freebsd.org/D19969
is requested by the application using the IPPROTO_IPV6 level socket option
IPV6_CHECKSUM on a raw socket, ensure that the packet contains enough
bytes to contain the checksum at the specified offset.
Reported by: syzbot+6295fcc5a8aced81d599@syzkaller.appspotmail.com
Reviewed by: bz@
Sponsored by: Netflix, Inc.
Differential Revision: https://reviews.freebsd.org/D19968
as requested by the user via the IPPROTO_IPV6 level socket option
IPV6_CHECKSUM. The check if there are enough bytes in the packet to
store the checksum at the requested offset was wrong by 1.
Reviewed by: bz@
MFC after: 1 week
Sponsored by: Netflix, Inc.
Differential Revision: https://reviews.freebsd.org/D19967
When using the IPPROTO_IPV6 level socket option IPV6_CHECKSUM on a raw
IPv6 socket, ensure that the value is either -1 or a non-negative even
number.
Reviewed by: bz@, thj@
MFC after: 1 week
Sponsored by: Netflix, Inc.
Differential Revision: https://reviews.freebsd.org/D19966
Add a stat counter to track ipv6 atomic fragments. Atomic fragments can be
generated in response to invalid path MTU values, but are also a potential
attack vector and considered harmful (see RFC6946 and RFC8021).
While here add tracking of the atomic fragment counter to netstat and systat.
Reviewed by: tuexen, jtl, bz
Approved by: jtl (mentor), bz (mentor)
Event: Aberdeen hackathon 2019
Differential Revision: https://reviews.freebsd.org/D17511
When leaving a multicast group, a hole may be created in the inpcb's
source filter and group membership arrays. To remove the hole, the
succeeding array elements are copied over by one entry. The multicast
code expects that a newly allocated array element is initialized, but
the code which shifts a tail of the array was leaving stale data
in the final entry. Fix this by explicitly reinitializing the last
entry following such a copy.
Reported by: syzbot+f8c3c564ee21d650475e@syzkaller.appspotmail.com
Reviewed by: ae
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D19872
stf(4) interfaces are not multicast-capable so they can't perform DAD.
They also did not set IFF_DRV_RUNNING when an address was assigned, so
the logic in nd6_timer() would periodically flag such an address as
tentative, resulting in interface flapping.
Fix the problem by setting IFF_DRV_RUNNING when an address is assigned,
and do some related cleanup:
- In in6if_do_dad(), remove a redundant check for !UP || !RUNNING.
There is only one caller in the tree, and it only looks at whether
the return value is non-zero.
- Have in6if_do_dad() return false if the interface is not
multicast-capable.
- Set ND6_IFF_NO_DAD when an address is assigned to an stf(4) interface
and the interface goes UP as a result. Note that this is not
sufficient to fix the problem because the new address is marked as
tentative and DAD is started before in6_ifattach() is called.
However, setting no_dad is formally correct.
- Change nd6_timer() to not flag addresses as tentative if no_dad is
set.
This is based on a patch from Viktor Dukhovni.
Reported by: Viktor Dukhovni <ietf-dane@dukhovni.org>
Reviewed by: ae
MFC after: 3 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D19751
Update NAT64LSN implementation:
o most of data structures and relations were modified to be able support
large number of translation states. Now each supported protocol can
use full ports range. Ports groups now are belongs to IPv4 alias
addresses, not hosts. Each ports group can keep several states chunks.
This is controlled with new `states_chunks` config option. States
chunks allow to have several translation states for single alias address
and port, but for different destination addresses.
o by default all hash tables now use jenkins hash.
o ConcurrencyKit and epoch(9) is used to make NAT64LSN lockless on fast path.
o one NAT64LSN instance now can be used to handle several IPv6 prefixes,
special prefix "::" value should be used for this purpose when instance
is created.
o due to modified internal data structures relations, the socket opcode
that does states listing was changed.
Obtained from: Yandex LLC
MFC after: 1 month
Sponsored by: Yandex LLC
o most of data structures and relations were modified to be able support
large number of translation states. Now each supported protocol can
use full ports range. Ports groups now are belongs to IPv4 alias
addresses, not hosts. Each ports group can keep several states chunks.
This is controlled with new `states_chunks` config option. States
chunks allow to have several translation states for single alias address
and port, but for different destination addresses.
o by default all hash tables now use jenkins hash.
o ConcurrencyKit and epoch(9) is used to make NAT64LSN lockless on fast path.
o one NAT64LSN instance now can be used to handle several IPv6 prefixes,
special prefix "::" value should be used for this purpose when instance
is created.
o due to modified internal data structures relations, the socket opcode
that does states listing was changed.
Obtained from: Yandex LLC
MFC after: 1 month
Sponsored by: Yandex LLC
CLAT is customer-side translator that algorithmically translates 1:1
private IPv4 addresses to global IPv6 addresses, and vice versa.
It is implemented as part of ipfw_nat64 kernel module. When module
is loaded or compiled into the kernel, it registers "nat64clat" external
action. External action named instance can be created using `create`
command and then used in ipfw rules. The create command accepts two
IPv6 prefixes `plat_prefix` and `clat_prefix`. If plat_prefix is ommitted,
IPv6 NAT64 Well-Known prefix 64:ff9b::/96 will be used.
# ipfw nat64clat CLAT create clat_prefix SRC_PFX plat_prefix DST_PFX
# ipfw add nat64clat CLAT ip4 from IPv4_PFX to any out
# ipfw add nat64clat CLAT ip6 from DST_PFX to SRC_PFX in
Obtained from: Yandex LLC
Submitted by: Boris N. Lytochkin
MFC after: 1 month
Relnotes: yes
Sponsored by: Yandex LLC
Add second IPv6 prefix to generic config structure and rename another
fields to conform to RFC6877. Now it contains two prefixes and length:
PLAT is provider-side translator that translates N:1 global IPv6 addresses
to global IPv4 addresses. CLAT is customer-side translator (XLAT) that
algorithmically translates 1:1 IPv4 addresses to global IPv6 addresses.
Use PLAT prefix in stateless (nat64stl) and stateful (nat64lsn)
translators.
Modify nat64_extract_ip4() and nat64_embed_ip4() functions to accept
prefix length and use plat_plen to specify prefix length.
Retire net.inet.ip.fw.nat64_allow_private sysctl variable.
Add NAT64_ALLOW_PRIVATE flag and use "allow_private" config option to
configure this ability separately for each NAT64 instance.
Obtained from: Yandex LLC
MFC after: 1 month
Sponsored by: Yandex LLC
When we roam between networks and our link-state goes down, automatically remove
the IPv6-Only flag from the interface. Otherwise we might switch from an
IPv6-only to and IPv4-only network and the flag would stay and we would prevent
IPv4 from working.
While the actual function call to clear the flag is under EXPERIMENTAL,
the eventhandler is not as we might want to re-use it for other
functionality on link-down event (such was re-calculate default routers
for example if there is more than one).
Reviewed by: hrs
Differential Revision: https://reviews.freebsd.org/D19487
All changes are hidden behind the EXPERIMENTAL option and are not compiled
in by default.
Add ND6_IFF_IPV6_ONLY_MANUAL to be able to set the interface into no-IPv4-mode
manually without router advertisement options. This will allow developers to
test software for the appropriate behaviour even on dual-stack networks or
IPv6-Only networks without the option being set in RA messages.
Update ifconfig to allow setting and displaying the flag.
Update the checks for the filters to check for either the automatic or the manual
flag to be set. Add REVARP to the list of filtered IPv4-related protocols and add
an input filter similar to the output filter.
Add a check, when receiving the IPv6-Only RA flag to see if the receiving
interface has any IPv4 configured. If it does, ignore the IPv6-Only flag.
Add a per-VNET global sysctl, which is on by default, to not process the automatic
RA IPv6-Only flag. This way an administrator (if this is compiled in) has control
over the behaviour in case the node still relies on IPv4.
When dropping a fragment queue, account for the number of fragments in the
queue. This improves accounting between the number of fragments received and
the number of fragments dropped.
Reviewed by: jtl, bz, transport
Approved by: jtl (mentor), bz (mentor)
Differential Revision: https://review.freebsd.org/D17521
The KPI have been reviewed and cleansed of features that were planned
back 20 years ago and never implemented. The pfil(9) internals have
been made opaque to protocols with only returned types and function
declarations exposed. The KPI is made more strict, but at the same time
more extensible, as kernel uses same command structures that userland
ioctl uses.
In nutshell [KA]PI is about declaring filtering points, declaring
filters and linking and unlinking them together.
New [KA]PI makes it possible to reconfigure pfil(9) configuration:
change order of hooks, rehook filter from one filtering point to a
different one, disconnect a hook on output leaving it on input only,
prepend/append a filter to existing list of filters.
Now it possible for a single packet filter to provide multiple rulesets
that may be linked to different points. Think of per-interface ACLs in
Cisco or Juniper. None of existing packet filters yet support that,
however limited usage is already possible, e.g. default ruleset can
be moved to single interface, as soon as interface would pride their
filtering points.
Another future feature is possiblity to create pfil heads, that provide
not an mbuf pointer but just a memory pointer with length. That would
allow filtering at very early stages of a packet lifecycle, e.g. when
packet has just been received by a NIC and no mbuf was yet allocated.
Differential Revision: https://reviews.freebsd.org/D18951
connectivity.
Looking at past changes in this area like r337866, some refcounting
bugs have been introduced, one by one. For example like calling
in6m_disconnect() and in6m_rele_locked() in mld_v1_process_group_timer()
where previously no disconnect nor refcount decrement was done.
Calling in6m_disconnect() when it shouldn't causes IPv6 solitation to no
longer work, because all the multicast addresses receiving the solitation
messages are now deleted from the network interface.
This patch reverts some recent changes while improving the MLD
refcounting and concurrency model after the MLD code was converted
to using EPOCH(9).
List changes:
- All CK_STAILQ_FOREACH() macros are now properly enclosed into
EPOCH(9) sections. This simplifies assertion of locking inside
in6m_ifmultiaddr_get_inm().
- Corrected bad use of in6m_disconnect() leading to loss of IPv6
connectivity for MLD v1.
- Factored out checks for valid inm structure into
in6m_ifmultiaddr_get_inm().
PR: 233535
Differential Revision: https://reviews.freebsd.org/D18887
Reviewed by: bz (net)
Tested by: ae
MFC after: 1 week
Sponsored by: Mellanox Technologies
because the destructor will access the if_ioctl() callback in the ifnet
pointer which is about to be freed. This prevents use-after-free.
PR: 233535
Differential Revision: https://reviews.freebsd.org/D18887
Reviewed by: bz (net)
Tested by: ae
MFC after: 1 week
Sponsored by: Mellanox Technologies
After the afdata read lock was converted to epoch(9), readers could
observe a linked LLE and block on the LLE while a thread was
unlinking the LLE. The writer would then release the lock and schedule
the LLE for deferred free, allowing readers to continue and potentially
schedule the LLE timer. By the point the timer fires, the structure is
freed, typically resulting in a crash in the callout subsystem.
Fix the problem by modifying the lookup path to check for the LLE_LINKED
flag upon acquiring the LLE lock. If it's not set, the lookup fails.
PR: 234296
Reviewed by: bz
Tested by: sbruno, Victor <chernov_victor@list.ru>,
Mike Andrews <mandrews@bit0.com>
MFC after: 3 days
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D18906
The loopback interface can only receive packets with a single scope ID,
namely the scope ID of the loopback interface itself. To mitigate this
packets which use the scope ID are appearing as received by the real
network interface, see "origifp" in the patch. The current code would
drop packets which are designated for loopback which use a link-local
scope ID in the destination address or source address, because they
won't match the lo0's scope ID. To fix this restore the network
interface pointer from the scope ID in the destination address for
the problematic cases. See comments added in patch for a more detailed
description.
This issue was introduced with route caching (ae@).
Reviewed by: bz (network)
Differential Revision: https://reviews.freebsd.org/D18769
MFC after: 1 week
Sponsored by: Mellanox Technologies
- Remove macros that covertly create epoch_tracker on thread stack. Such
macros a quite unsafe, e.g. will produce a buggy code if same macro is
used in embedded scopes. Explicitly declare epoch_tracker always.
- Unmask interface list IFNET_RLOCK_NOSLEEP(), interface address list
IF_ADDR_RLOCK() and interface AF specific data IF_AFDATA_RLOCK() read
locking macros to what they actually are - the net_epoch.
Keeping them as is is very misleading. They all are named FOO_RLOCK(),
while they no longer have lock semantics. Now they allow recursion and
what's more important they now no longer guarantee protection against
their companion WLOCK macros.
Note: INP_HASH_RLOCK() has same problems, but not touched by this commit.
This is non functional mechanical change. The only functionally changed
functions are ni6_addrs() and ni6_store_addrs(), where we no longer enter
epoch recursively.
Discussed with: jtl, gallatin
Memory beyond that limit was previously unused, wasting roughly 1MB per
8GB of RAM. Also retire INP_PCBLBGROUP_PORTHASH, which was identical to
INP_PCBPORTHASH.
Reviewed by: glebius
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D17803
Various network protocol sysctl handlers were not zero-filling their
output buffers and thus would export uninitialized stack memory to
userland. Fix a number of such handlers.
Reported by: Thomas Barabosch, Fraunhofer FKIE
Reviewed by: tuexen
MFC after: 3 days
Security: kernel memory disclosure
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D18301
Now an interface name can be specified for nptv6 instance instead of
ext_prefix. The module will track if_addr_ext events and when suitable
IPv6 address will be added to specified interface, it will be configured
as external prefix. When address disappears instance becomes unusable,
i.e. it doesn't match any packets.
Reviewed by: 0mp (manpages)
Tested by: Dries Michiels <driesm dot michiels gmail com>
MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D17765
If another thread immediately removes the link-local address
added by in6_update_ifa(), in6ifa_ifpforlinklocal() can return NULL,
so the following assertion (or dereference) is wrong.
Remove the assertion, and handle NULL somewhat better than panicking.
This matches all of the other callers of in6_update_ifa().
PR: 219250
Reviewed by: bz, dab (both an earlier version)
MFC after: 1 week
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D17898
This change defines the RA "6" (IPv6-Only) flag which routers
may advertise, kernel logic to check if all routers on a link
have the flag set and accordingly update a per-interface flag.
If all routers agree that it is an IPv6-only link, ether_output_frame(),
based on the interface flag, will filter out all ETHERTYPE_IP/ARP
frames, drop them, and return EAFNOSUPPORT to upper layers.
The change also updates ndp to show the "6" flag, ifconfig to
display the IPV6_ONLY nd6 flag if set, and rtadvd to allow
announcing the flag.
Further changes to tcpdump (contrib code) are availble and will
be upstreamed.
Tested the code (slightly earlier version) with 2 FreeBSD
IPv6 routers, a FreeBSD laptop on ethernet as well as wifi,
and with Win10 and OSX clients (which did not fall over with
the "6" flag set but not understood).
We may also want to (a) implement and RX filter, and (b) over
time enahnce user space to, say, stop dhclient from running
when the interface flag is set. Also we might want to start
IPv6 before IPv4 in the future.
All the code is hidden under the EXPERIMENTAL option and not
compiled by default as the draft is a work-in-progress and
we cannot rely on the fact that IANA will assign the bits
as requested by the draft and hence they may change.
Dear 6man, you have running code.
Discussed with: Bob Hinden, Brian E Carpenter
After r335924 rip6_input() needs inp validation to avoid
working on FREED inps.
Apply the relevant bits from r335497,r335501 (rip_input() change)
to the IPv6 counterpart.
PR: 232194
Reviewed by: rgrimes, ae (,hps)
MFC after: 3 days
Differential Revision: https://reviews.freebsd.org/D17594
This change is similar to r339646. The callback that checks for appearing
and disappearing of tunnel ingress address can be called during VNET
teardown. To prevent access to already freed memory, add check to the
callback and epoch_wait() call to be sure that callback has finished its
work.
MFC after: 20 days
This should have been a part of r338470. No functional changes
intended.
Reported by: gallatin
Reviewed by: gallatin, Johannes Lundberg <johalun0@gmail.com>
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D17109
* register handler for ingress address appearing/disappearing;
* add new srcaddr hash table for fast softc lookup by srcaddr;
* when srcaddr disappears, clear IFF_DRV_RUNNING flag from interface,
and set it otherwise;
MFC after: 1 month
Sponsored by: Yandex LLC
Differential Revision: https://reviews.freebsd.org/D17214
* register handler for ingress address appearing/disappearing;
* add new srcaddr hash table for fast softc lookup by srcaddr;
* when srcaddr disappears, clear IFF_DRV_RUNNING flag from interface,
and set it otherwise;
* remove the note about ingress address from BUGS section.
MFC after: 1 month
Sponsored by: Yandex LLC
Differential Revision: https://reviews.freebsd.org/D17134
handler receives the type of event IFADDR_EVENT_ADD/IFADDR_EVENT_DEL,
and the pointer to ifaddr. Also ifaddr_event now is implemented using
ifaddr_event_ext handler.
MFC after: 3 weeks
Sponsored by: Yandex LLC
Differential Revision: https://reviews.freebsd.org/D17100
epoch section without exiting that epoch section. This is bad for two
reasons: the epoch section won't exit, and we will leave the epoch tracker
from the stack on the epoch list.
Fix the epoch leak by making sure we exit epoch sections before returning.
Reviewed by: ae, gallatin, mmacy
Approved by: re (gjb, kib)
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D17450
using an application trying to use a v4mapped destination address on a
kernel without INET support or on a v6only socket.
Catch this case and prevent the packet from going anywhere;
else, without the KASSERT() armed, a v4mapped destination
address might go out on the wire or other undefined behaviour
might happen, while with the KASSERT() we panic.
PR: 231728
Reported by: Jeremy Faulkner (gldisater gmail.com)
Approved by: re (kib)
once we have a lock, make sure the inp is not marked freed.
This can happen since the list traversal and locking was
converted to epoch(9). If the inp is marked "freed", skip it.
This prevents a NULL pointer deref panic later on.
Reported by: slavash (Mellanox)
Tested by: slavash (Mellanox)
Reviewed by: markj (no formal review but caught my unlock mistake)
Approved by: re (kib)
not freed. This can happen since the list traversal and locking
was converted to epoch(9). If the inp is marked "freed", skip it.
This prevents a NULL pointer deref panic in ip6_savecontrol_v4()
trying to access the socket hanging off the inp, which was gone
by the time we got there.
Reported by: andrew
Tested by: andrew
Approved by: re (gjb)
route cache updates.
Bring over locking changes applied to udp_output() for the route cache
in r297225 and fixed in r306559 which achieve multiple things:
(1) acquire an exclusive inp lock earlier depending on the expected
conditions; we add a comment explaining this in udp6,
(2) having acquired the exclusive lock earlier eliminates a slight
possible chance for a race condition which was present in v4 for
multiple years as well and is now gone, and
(3) only pass the inp_route6 to ip6_output() if we are holding an
exclusive inp lock, so that possible route cache updates in case
of routing table generation number changes can happen safely.
In addition this change (as the legacy IP counterpart) decomposes the
tracking of inp and pcbinfo lock and adds extra assertions, that the
two together are acquired correctly.
PR: 230950
Reviewed by: karels, markj
Approved by: re (gjb)
Pointyhat to: bz (for completely missing this bit)
Differential Revision: https://reviews.freebsd.org/D17230
Lookups are protected by an epoch section, so the LB group linkage must
be a CK_LIST rather than a plain LIST. Furthermore, we were not
deferring LB group frees, so in_pcbremlbgrouphash() could race with
readers and cause a use-after-free.
Reviewed by: sbruno, Johannes Lundberg <johalun0@gmail.com>
Tested by: gallatin
Approved by: re (gjb)
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D17031
to clear L2 and L3 route caches.
Also mark one function argument as __unused.
Reviewed by: karels, ae
Approved by: re (rgrimes)
Differential Revision: https://reviews.freebsd.org/D17007
macro rather than hand crafted code.
No functional changes.
Reviewed by: karels
Approved by: re (rgrimes)
Differential Revision: https://reviews.freebsd.org/D17006
inp_route6 for IPv6 code after r301217.
This was most likely a c&p error from the legacy IP code, which
did not matter as it is a union and both structures have the same
layout at the beginning.
No functional changes.
Reviewed by: karels, ae
Approved by: re (rgrimes)
Differential Revision: https://reviews.freebsd.org/D17005
