netlink_dump structure has a union of 'long args[6]' and a context
buffer as scratch space.
Convert ctnetlink to use a structure, its easier to read than the
raw 'args' usage which comes with no type checks and no readable names.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
When userspace, e.g. conntrackd, inserts an entry with a specified helper,
its possible that the helper is lost immediately after its added:
ctnetlink_create_conntrack
-> nf_ct_helper_ext_add + assign helper
-> ctnetlink_setup_nat
-> ctnetlink_parse_nat_setup
-> parse_nat_setup -> nfnetlink_parse_nat_setup
-> nf_nat_setup_info
-> nf_conntrack_alter_reply
-> __nf_ct_try_assign_helper
... and __nf_ct_try_assign_helper will zero the helper again.
Set IPS_HELPER bit to bypass auto-assign logic, its unwanted, just like
when helper is assigned via ruleset.
Dropped old 'not strictly necessary' comment, it referred to use of
rcu_assign_pointer() before it got replaced by RCU_INIT_POINTER().
NB: Fixes tag intentionally incorrect, this extends the referenced commit,
but this change won't build without IPS_HELPER introduced there.
Fixes: 6714cf5465 ("netfilter: nf_conntrack: fix explicit helper attachment and NAT")
Reported-by: Pham Thanh Tuyen <phamtyn@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Pablo Neira Ayuso says:
====================
Netfilter updates for net-next
The following patchset contains Netfilter updates for net-next. This
includes one patch to update ovs and act_ct to use nf_ct_put() instead
of nf_conntrack_put().
1) Add netns_tracker to nfnetlink_log and masquerade, from Eric Dumazet.
2) Remove redundant rcu read-size lock in nf_tables packet path.
3) Replace BUG() by WARN_ON_ONCE() in nft_payload.
4) Consolidate rule verdict tracing.
5) Replace WARN_ON() by WARN_ON_ONCE() in nf_tables core.
6) Make counter support built-in in nf_tables.
7) Add new field to conntrack object to identify locally generated
traffic, from Florian Westphal.
8) Prevent NAT from shadowing well-known ports, from Florian Westphal.
9) Merge nf_flow_table_{ipv4,ipv6} into nf_flow_table_inet, also from
Florian.
10) Remove redundant pointer in nft_pipapo AVX2 support, from Colin Ian King.
11) Replace opencoded max() in conntrack, from Jiapeng Chong.
12) Update conntrack to use refcount_t API, from Florian Westphal.
13) Move ip_ct_attach indirection into the nf_ct_hook structure.
14) Constify several pointer object in the netfilter codebase,
from Florian Westphal.
15) Tree-wide replacement of nf_conntrack_put() by nf_ct_put(), also
from Florian.
16) Fix egress splat due to incorrect rcu notation, from Florian.
17) Move stateful fields of connlimit, last, quota, numgen and limit
out of the expression data area.
18) Build a blob to represent the ruleset in nf_tables, this is a
requirement of the new register tracking infrastructure.
19) Add NFT_REG32_NUM to define the maximum number of 32-bit registers.
20) Add register tracking infrastructure to skip redundant
store-to-register operations, this includes support for payload,
meta and bitwise expresssions.
* git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next: (32 commits)
netfilter: nft_meta: cancel register tracking after meta update
netfilter: nft_payload: cancel register tracking after payload update
netfilter: nft_bitwise: track register operations
netfilter: nft_meta: track register operations
netfilter: nft_payload: track register operations
netfilter: nf_tables: add register tracking infrastructure
netfilter: nf_tables: add NFT_REG32_NUM
netfilter: nf_tables: add rule blob layout
netfilter: nft_limit: move stateful fields out of expression data
netfilter: nft_limit: rename stateful structure
netfilter: nft_numgen: move stateful fields out of expression data
netfilter: nft_quota: move stateful fields out of expression data
netfilter: nft_last: move stateful fields out of expression data
netfilter: nft_connlimit: move stateful fields out of expression data
netfilter: egress: avoid a lockdep splat
net: prefer nf_ct_put instead of nf_conntrack_put
netfilter: conntrack: avoid useless indirection during conntrack destruction
netfilter: make function op structures const
netfilter: core: move ip_ct_attach indirection to struct nf_ct_hook
netfilter: conntrack: convert to refcount_t api
...
====================
Link: https://lore.kernel.org/r/20220109231640.104123-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
No functional changes, these structures should be const.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Convert nf_conn reference counting from atomic_t to refcount_t based api.
refcount_t api provides more runtime sanity checks and will warn on
certain constructs, e.g. refcount_inc() on a zero reference count, which
usually indicates use-after-free.
For this reason template allocation is changed to init the refcount to
1, the subsequenct add operations are removed.
Likewise, init_conntrack() is changed to set the initial refcount to 1
instead refcount_inc().
This is safe because the new entry is not (yet) visible to other cpus.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
When dumping conntrack table to userspace via ctnetlink, check if the ct has
already expired before doing any of the 'skip' checks.
This expires dead entries faster.
/proc handler also removes outdated entries first.
Reported-by: Vitaly Zuevsky <vzuevsky@ns1.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Pablo Neira Ayuso says:
====================
Netfilter updates for net-next
The following patchset contains Netfilter updates for net-next, mostly
rather small housekeeping patches:
1) Remove unused variable in IPVS, from GuoYong Zheng.
2) Use memset_after in conntrack, from Kees Cook.
3) Remove leftover function in nfnetlink_queue, from Florian Westphal.
4) Remove redundant test on bool in conntrack, from Bernard Zhao.
5) egress support for nft_fwd, from Lukas Wunner.
6) Make pppoe work for br_netfilter, from Florian Westphal.
7) Remove unused variable in conntrack resize routine, from luo penghao.
* git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next:
netfilter: conntrack: Remove useless assignment statements
netfilter: bridge: add support for pppoe filtering
netfilter: nft_fwd_netdev: Support egress hook
netfilter: ctnetlink: remove useless type conversion to bool
netfilter: nf_queue: remove leftover synchronize_rcu
netfilter: conntrack: Use memset_startat() to zero struct nf_conn
ipvs: remove unused variable for ip_vs_new_dest
====================
Link: https://lore.kernel.org/r/20211215234911.170741-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
dying is bool, the type conversion to true/false value is not
needed.
Signed-off-by: Bernard Zhao <bernard@vivo.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
siphash keys use 16 bytes.
Define siphash_aligned_key_t macro so that we can make sure they
are not crossing a cache line boundary.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
And be consistent in error management for both orig/reply filtering
Fixes: cb8aa9a3af ("netfilter: ctnetlink: add kernel side filtering for dump")
Signed-off-by: Florent Fourcot <florent.fourcot@wifirst.fr>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
filter->orig_flags was used for a reply context.
Fixes: cb8aa9a3af ("netfilter: ctnetlink: add kernel side filtering for dump")
Signed-off-by: Florent Fourcot <florent.fourcot@wifirst.fr>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Pablo Neira Ayuso says:
====================
Netfilter fixes for net
1) Protect nft_ct template with global mutex, from Pavel Skripkin.
2) Two recent commits switched inet rt and nexthop exception hashes
from jhash to siphash. If those two spots are problematic then
conntrack is affected as well, so switch voer to siphash too.
While at it, add a hard upper limit on chain lengths and reject
insertion if this is hit. Patches from Florian Westphal.
3) Fix use-after-scope in nf_socket_ipv6 reported by KASAN,
from Benjamin Hesmans.
* git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf:
netfilter: socket: icmp6: fix use-after-scope
netfilter: refuse insertion if chain has grown too large
netfilter: conntrack: switch to siphash
netfilter: conntrack: sanitize table size default settings
netfilter: nft_ct: protect nft_ct_pcpu_template_refcnt with mutex
====================
Link: https://lore.kernel.org/r/20210903163020.13741-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Also add a stat counter for this that gets exported both via old /proc
interface and ctnetlink.
Assuming the old default size of 16536 buckets and max hash occupancy of
64k, this results in 128k insertions (origin+reply), so ~8 entries per
chain on average.
The revised settings in this series will result in about two entries per
bucket on average.
This allows a hard-limit ceiling of 64.
This is not tunable at the moment, but its possible to either increase
nf_conntrack_buckets or decrease nf_conntrack_max to reduce average
lengths.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Add counters and timestamps (if available) to the conntrack object
that is represented in nfnetlink_log and _queue messages.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Reuse the conntrack event notofier struct, this allows to remove the
extra register/unregister functions and avoids a pointer in struct net.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This prepares for merge for ct and exp notifier structs.
The 'fcn' member is renamed to something unique.
Second, the register/unregister api is simplified. There is only
one implementation so there is no need to do any error checking.
Replace the EBUSY logic with WARN_ON_ONCE. This allows to remove
error unwinding.
The exp notifier register/unregister function is removed in
a followup patch.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
nf_conntrack_eventmask_report and nf_ct_deliver_cached_events shared
most of their code. This unifies the layout by changing
if (nf_ct_is_confirmed(ct)) {
foo
}
to
if (!nf_ct_is_confirmed(ct)))
return
foo
This removes one level of indentation.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
If CTA_STATUS is present, but CTA_STATUS_MASK is not, then the
mask is automatically set to 'status', so that kernel returns those
entries that have all of the requested bits set.
This makes more sense than using a all-one mask since we'd hardly
ever find a match.
There are no other checks for status bits, so if e.g. userspace
sets impossible combinations it will get an empty dump.
If kernel would reject unknown status bits, then a program that works on
a future kernel that has IPS_FOO bit fails on old kernels.
Same for 'impossible' combinations:
Kernel never sets ASSURED without first having set SEEN_REPLY, but its
possible that a future kernel could do so.
Therefore no sanity tests other than a 0-mask.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
ctnetlink dumps can be filtered based on the connmark.
Prepare for status bit filtering by using a named structure and by
moving the mark parsing code to a helper.
Else ctnetlink_alloc_filter size grows a bit too big for my taste
when status handling is added.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Update the nfnl_info structure to add a pointer to the nfnetlink header.
This simplifies the existing codebase since this header is usually
accessed. Update existing clients to use this new field.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Replace netlink_unicast() calls by nfnetlink_unicast() which already
deals with translating EAGAIN to ENOBUFS as the nfnetlink core expects.
nfnetlink_unicast() calls nlmsg_unicast() which returns zero in case of
success, otherwise the netlink core function netlink_rcv_skb() turns
err > 0 into an acknowlegment.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Add a new structure to reduce callback footprint and to facilite
extensions of the nfnetlink callback interface in the future.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Its only needed from slowpath (sysctl, ctnetlink, gc worker) and
when a new conntrack object is allocated.
Furthermore, each write dirties the otherwise read-mostly pernet
data in struct net.ct, which are accessed from packet path.
Move it to the net_generic data. This makes struct netns_ct
read-mostly.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch adds a helper function to set up the netlink and nfnetlink headers.
Update existing codebase to use it.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Before this change, the mask is never included in the netlink message, so
"conntrack -E expect" always prints 0.0.0.0.
In older kernels the l3num callback struct was passed as argument, based
on tuple->src.l3num. After the l3num indirection got removed, the call
chain is based on m.src.l3num, but this value is 0xffff.
Init l3num to the correct value.
Fixes: f957be9d34 ("netfilter: conntrack: remove ctnetlink callbacks from l3 protocol trackers")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Use nf_ct_get() directly, its a small inline helper without dependencies.
Add CONFIG_NF_CONNTRACK guards to elide the relevant part when conntrack
isn't available at all.
v2: add ifdef guard around nf_ct_get call (kernel test robot)
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
DESTROY events do not include the remaining timeout.
Add the timeout if the entry was removed explicitly. This can happen
when a conntrack gets deleted prematurely, e.g. due to a tcp reset,
module removal, netdev notifier (nat/masquerade device went down),
ctnetlink and so on.
Add the protocol state too for the destroy message to check for abnormal
state on connection termination.
Joint work with Pablo.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Two minor conflicts:
1) net/ipv4/route.c, adding a new local variable while
moving another local variable and removing it's
initial assignment.
2) drivers/net/dsa/microchip/ksz9477.c, overlapping changes.
One pretty prints the port mode differently, whilst another
changes the driver to try and obtain the port mode from
the port node rather than the switch node.
Signed-off-by: David S. Miller <davem@davemloft.net>
conntrack mark based dump filtering may falsely skip entries if a mask
is given: If the mask-based check does not filter out the entry, the
else-if check is always true and compares the mark without considering
the mask. The if/else-if logic seems wrong.
Given that the mask during filter setup is implicitly set to 0xffffffff
if not specified explicitly, the mark filtering flags seem to just
complicate things. Restore the previously used approach by always
matching against a zero mask is no filter mark is given.
Fixes: cb8aa9a3af ("netfilter: ctnetlink: add kernel side filtering for dump")
Signed-off-by: Martin Willi <martin@strongswan.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The indexes to the nf_nat_l[34]protos arrays come from userspace. So
check the tuple's family, e.g. l3num, when creating the conntrack in
order to prevent an OOB memory access during setup. Here is an example
kernel panic on 4.14.180 when userspace passes in an index greater than
NFPROTO_NUMPROTO.
Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
Modules linked in:...
Process poc (pid: 5614, stack limit = 0x00000000a3933121)
CPU: 4 PID: 5614 Comm: poc Tainted: G S W O 4.14.180-g051355490483
Hardware name: Qualcomm Technologies, Inc. SM8150 V2 PM8150 Google Inc. MSM
task: 000000002a3dfffe task.stack: 00000000a3933121
pc : __cfi_check_fail+0x1c/0x24
lr : __cfi_check_fail+0x1c/0x24
...
Call trace:
__cfi_check_fail+0x1c/0x24
name_to_dev_t+0x0/0x468
nfnetlink_parse_nat_setup+0x234/0x258
ctnetlink_parse_nat_setup+0x4c/0x228
ctnetlink_new_conntrack+0x590/0xc40
nfnetlink_rcv_msg+0x31c/0x4d4
netlink_rcv_skb+0x100/0x184
nfnetlink_rcv+0xf4/0x180
netlink_unicast+0x360/0x770
netlink_sendmsg+0x5a0/0x6a4
___sys_sendmsg+0x314/0x46c
SyS_sendmsg+0xb4/0x108
el0_svc_naked+0x34/0x38
This crash is not happening since 5.4+, however, ctnetlink still
allows for creating entries with unsupported layer 3 protocol number.
Fixes: c1d10adb4a ("[NETFILTER]: Add ctnetlink port for nf_conntrack")
Signed-off-by: Will McVicker <willmcvicker@google.com>
[pablo@netfilter.org: rebased original patch on top of nf.git]
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
There is a misconception about what "insert_failed" means.
We increment this even when a clash got resolved, so it might not indicate
a problem.
Add a dedicated counter for clash resolution and only increment
insert_failed if a clash cannot be resolved.
For the old /proc interface, export this in place of an older stat
that got removed a while back.
For ctnetlink, export this with a new attribute.
Also correct an outdated comment that implies we add a duplicate tuple --
we only add the (unique) reply direction.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This counter increments when nf_conntrack_in sees a packet that already
has a conntrack attached or when the packet is marked as UNTRACKED.
Neither is an error.
The former is normal for loopback traffic. The second happens for
certain ICMPv6 packets or when nftables/ip(6)tables rules are in place.
In case someone needs to count UNTRACKED packets, or packets
that are marked as untracked before conntrack_in this can be done with
both nftables and ip(6)tables rules.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Conntrack dump does not support kernel side filtering (only get exists,
but it returns only one entry. And user has to give a full valid tuple)
It means that userspace has to implement filtering after receiving many
irrelevant entries, consuming resources (conntrack table is sometimes
very huge, much more than a routing table for example).
This patch adds filtering in kernel side. To achieve this goal, we:
* Add a new CTA_FILTER netlink attributes, actually a flag list to
parametize filtering
* Convert some *nlattr_to_tuple() functions, to allow a partial parsing
of CTA_TUPLE_ORIG and CTA_TUPLE_REPLY (so nf_conntrack_tuple it not
fully set)
Filtering is now possible on:
* IP SRC/DST values
* Ports for TCP and UDP flows
* IMCP(v6) codes types and IDs
Filtering is done as an "AND" operator. For example, when flags
PROTO_SRC_PORT, PROTO_NUM and IP_SRC are sets, only entries matching all
values are dumped.
Changes since v1:
Set NLM_F_DUMP_FILTERED in nlm flags if entries are filtered
Changes since v2:
Move several constants to nf_internals.h
Move a fix on netlink values check in a separate patch
Add a check on not-supported flags
Return EOPNOTSUPP if CDA_FILTER is set in ctnetlink_flush_conntrack
(not yet implemented)
Code style issues
Changes since v3:
Fix compilation warning reported by kbuild test robot
Changes since v4:
Fix a regression introduced in v3 (returned EINVAL for valid netlink
messages without CTA_MARK)
Changes since v5:
Change definition of CTA_FILTER_F_ALL
Fix a regression when CTA_TUPLE_ZONE is not set
Signed-off-by: Romain Bellan <romain.bellan@wifirst.fr>
Signed-off-by: Florent Fourcot <florent.fourcot@wifirst.fr>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
When CONFIG_NF_CONNTRACK_MARK is not set, any CTA_MARK or CTA_MARK_MASK
in netlink message are not supported. We should return an error when one
of them is set, not both
Fixes: 9306425b70 ("netfilter: ctnetlink: must check mark attributes vs NULL")
Signed-off-by: Romain Bellan <romain.bellan@wifirst.fr>
Signed-off-by: Florent Fourcot <florent.fourcot@wifirst.fr>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Sparse reports a warning at ctnetlink_parse_nat_setup()
warning: context imbalance in ctnetlink_parse_nat_setup()
- unexpected unlock
The root cause is the missing annotation at ctnetlink_parse_nat_setup()
Add the missing __must_hold(RCU) annotation
Signed-off-by: Jules Irenge <jbi.octave@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Curtis Taylor and Jon Maxwell reported and debugged a crash on 3.10
based kernel.
Crash occurs in ctnetlink_conntrack_events because net->nfnl socket is
NULL. The nfnl socket was set to NULL by netns destruction running on
another cpu.
The exiting network namespace calls the relevant destructors in the
following order:
1. ctnetlink_net_exit_batch
This nulls out the event callback pointer in struct netns.
2. nfnetlink_net_exit_batch
This nulls net->nfnl socket and frees it.
3. nf_conntrack_cleanup_net_list
This removes all remaining conntrack entries.
This is order is correct. The only explanation for the crash so ar is:
cpu1: conntrack is dying, eviction occurs:
-> nf_ct_delete()
-> nf_conntrack_event_report \
-> nf_conntrack_eventmask_report
-> notify->fcn() (== ctnetlink_conntrack_events).
cpu1: a. fetches rcu protected pointer to obtain ctnetlink event callback.
b. gets interrupted.
cpu2: runs netns exit handlers:
a runs ctnetlink destructor, event cb pointer set to NULL.
b runs nfnetlink destructor, nfnl socket is closed and set to NULL.
cpu1: c. resumes and trips over NULL net->nfnl.
Problem appears to be that ctnetlink_net_exit_batch only prevents future
callers of nf_conntrack_eventmask_report() from obtaining the callback.
It doesn't wait of other cpus that might have already obtained the
callbacks address.
I don't see anything in upstream kernels that would prevent similar
crash: We need to wait for all cpus to have exited the event callback.
Fixes: 9592a5c01e ("netfilter: ctnetlink: netns support")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
When dumping the unconfirmed lists, the cpu that is processing the ct
entry can reallocate ct->ext at any time.
Right now accessing the extensions from another CPU is ok provided
we're holding rcu read lock: extension reallocation does use rcu.
Once RCU isn't used anymore this becomes unsafe, so skip extensions for
the unconfirmed list.
Dumping the extension area for confirmed or dying conntracks is fine:
no reallocations are allowed and list iteration holds appropriate
locks that prevent ct (and this ct->ext) from getting free'd.
v2: fix compiler warnings due to misue of 'const' and missing return
statement (kbuild robot).
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
If this flag is set, timeout and state are irrelevant to userspace.
Fixes: 90964016e5 ("netfilter: nf_conntrack: add IPS_OFFLOAD status bit")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
When conntracks change during a dialog, SDP messages may be sent from
different conntracks to establish expects with identical tuples. In this
case expects conflict may be detected for the 2nd SDP message and end up
with a process failure.
The fixing here is to reuse an existing expect who has the same tuple for a
different conntrack if any.
Here are two scenarios for the case.
1)
SERVER CPE
| INVITE SDP |
5060 |<----------------------|5060
| 100 Trying |
5060 |---------------------->|5060
| 183 SDP |
5060 |---------------------->|5060 ===> Conntrack 1
| PRACK |
50601 |<----------------------|5060
| 200 OK (PRACK) |
50601 |---------------------->|5060
| 200 OK (INVITE) |
5060 |---------------------->|5060
| ACK |
50601 |<----------------------|5060
| |
|<--- RTP stream ------>|
| |
| INVITE SDP (t38) |
50601 |---------------------->|5060 ===> Conntrack 2
With a certain configuration in the CPE, SIP messages "183 with SDP" and
"re-INVITE with SDP t38" will go through the sip helper to create
expects for RTP and RTCP.
It is okay to create RTP and RTCP expects for "183", whose master
connection source port is 5060, and destination port is 5060.
In the "183" message, port in Contact header changes to 50601 (from the
original 5060). So the following requests e.g. PRACK and ACK are sent to
port 50601. It is a different conntrack (let call Conntrack 2) from the
original INVITE (let call Conntrack 1) due to the port difference.
In this example, after the call is established, there is RTP stream but no
RTCP stream for Conntrack 1, so the RTP expect created upon "183" is
cleared, and RTCP expect created for Conntrack 1 retains.
When "re-INVITE with SDP t38" arrives to create RTP&RTCP expects, current
ALG implementation will call nf_ct_expect_related() for RTP and RTCP. The
expects tuples are identical to those for Conntrack 1. RTP expect for
Conntrack 2 succeeds in creation as the one for Conntrack 1 has been
removed. RTCP expect for Conntrack 2 fails in creation because it has
idential tuples and 'conflict' with the one retained for Conntrack 1. And
then result in a failure in processing of the re-INVITE.
2)
SERVER A CPE
| REGISTER |
5060 |<------------------| 5060 ==> CT1
| 200 |
5060 |------------------>| 5060
| |
| INVITE SDP(1) |
5060 |<------------------| 5060
| 300(multi choice) |
5060 |------------------>| 5060 SERVER B
| ACK |
5060 |<------------------| 5060
| INVITE SDP(2) |
5060 |-------------------->| 5060 ==> CT2
| 100 |
5060 |<--------------------| 5060
| 200(contact changes)|
5060 |<--------------------| 5060
| ACK |
5060 |-------------------->| 50601 ==> CT3
| |
|<--- RTP stream ---->|
| |
| BYE |
5060 |<--------------------| 50601
| 200 |
5060 |-------------------->| 50601
| INVITE SDP(3) |
5060 |<------------------| 5060 ==> CT1
CPE sends an INVITE request(1) to Server A, and creates a RTP&RTCP expect
pair for this Conntrack 1 (CT1). Server A responds 300 to redirect to
Server B. The RTP&RTCP expect pairs created on CT1 are removed upon 300
response.
CPE sends the INVITE request(2) to Server B, and creates an expect pair
for the new conntrack (due to destination address difference), let call
CT2. Server B changes the port to 50601 in 200 OK response, and the
following requests ACK and BYE from CPE are sent to 50601. The call is
established. There is RTP stream and no RTCP stream. So RTP expect is
removed and RTCP expect for CT2 retains.
As BYE request is sent from port 50601, it is another conntrack, let call
CT3, different from CT2 due to the port difference. So the BYE request will
not remove the RTCP expect for CT2.
Then another outgoing call is made, with the same RTP port being used (not
definitely but possibly). CPE firstly sends the INVITE request(3) to Server
A, and tries to create a RTP&RTCP expect pairs for this CT1. In current ALG
implementation, the RTCP expect for CT1 fails in creation because it
'conflicts' with the residual one for CT2. As a result the INVITE request
fails to send.
Signed-off-by: xiao ruizhu <katrina.xiaorz@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Commit f8e6089820 ("netfilter: ctnetlink: Resolve conntrack
L3-protocol flush regression") introduced a regression in which deletion
of conntrack entries would fail because the L3 protocol information
is replaced by AF_UNSPEC. As a result the search for the entry to be
deleted would turn up empty due to the tuple used to perform the search
is now different from the tuple used to initially set up the entry.
For flushing the conntrack table we do however want to keep the option
for nfgenmsg->version to have a non-zero value to allow for newer
user-space tools to request treatment under the new behavior. With that
it is possible to independently flush tables for a defined L3 protocol.
This was introduced with the enhancements in in commit 59c08c69c2
("netfilter: ctnetlink: Support L3 protocol-filter on flush").
Older user-space tools will retain the behavior of flushing all tables
regardless of defined L3 protocol.
Fixes: f8e6089820 ("netfilter: ctnetlink: Resolve conntrack L3-protocol flush regression")
Suggested-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Felix Kaechele <felix@kaechele.ca>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Pablo Neira Ayuso says:
====================
Netfilter fixes for net
The following patchset contains Netfilter fixes for net:
1) Postpone chain policy update to drop after transaction is complete,
from Florian Westphal.
2) Add entry to flowtable after confirmation to fix UDP flows with
packets going in one single direction.
3) Reference count leak in dst object, from Taehee Yoo.
4) Check for TTL field in flowtable datapath, from Taehee Yoo.
5) Fix h323 conntrack helper due to incorrect boundary check,
from Jakub Jankowski.
6) Fix incorrect rcu dereference when fetching basechain stats,
from Florian Westphal.
7) Missing error check when adding new entries to flowtable,
from Taehee Yoo.
8) Use version field in nfnetlink message to honor the nfgen_family
field, from Kristian Evensen.
9) Remove incorrect configuration check for CONFIG_NF_CONNTRACK_IPV6,
from Subash Abhinov Kasiviswanathan.
10) Prevent dying entries from being added to the flowtable,
from Taehee Yoo.
11) Don't hit WARN_ON() with malformed blob in ebtables with
trailing data after last rule, reported by syzbot, patch
from Florian Westphal.
12) Remove NFT_CT_TIMEOUT enumeration, never used in the kernel
code.
13) Fix incorrect definition for NFT_LOGLEVEL_MAX, from Florian
Westphal.
This batch comes with a conflict that can be fixed with this patch:
diff --cc include/uapi/linux/netfilter/nf_tables.h
index 7bdb234f3d8c,f0cf7b0f4f35..505393c6e959
--- a/include/uapi/linux/netfilter/nf_tables.h
+++ b/include/uapi/linux/netfilter/nf_tables.h
@@@ -966,6 -966,8 +966,7 @@@ enum nft_socket_keys
* @NFT_CT_DST_IP: conntrack layer 3 protocol destination (IPv4 address)
* @NFT_CT_SRC_IP6: conntrack layer 3 protocol source (IPv6 address)
* @NFT_CT_DST_IP6: conntrack layer 3 protocol destination (IPv6 address)
- * @NFT_CT_TIMEOUT: connection tracking timeout policy assigned to conntrack
+ * @NFT_CT_ID: conntrack id
*/
enum nft_ct_keys {
NFT_CT_STATE,
@@@ -991,6 -993,8 +992,7 @@@
NFT_CT_DST_IP,
NFT_CT_SRC_IP6,
NFT_CT_DST_IP6,
- NFT_CT_TIMEOUT,
+ NFT_CT_ID,
__NFT_CT_MAX
};
#define NFT_CT_MAX (__NFT_CT_MAX - 1)
That replaces the unused NFT_CT_TIMEOUT definition by NFT_CT_ID. If you prefer,
I can also solve this conflict here, just let me know.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit 59c08c69c2 ("netfilter: ctnetlink: Support L3 protocol-filter
on flush") introduced a user-space regression when flushing connection
track entries. Before this commit, the nfgen_family field was not used
by the kernel and all entries were removed. Since this commit,
nfgen_family is used to filter out entries that should not be removed.
One example a broken tool is conntrack. conntrack always sets
nfgen_family to AF_INET, so after 59c08c69c2 only IPv4 entries were
removed with the -F parameter.
Pablo Neira Ayuso suggested using nfgenmsg->version to resolve the
regression, and this commit implements his suggestion. nfgenmsg->version
is so far set to zero, so it is well-suited to be used as a flag for
selecting old or new flush behavior. If version is 0, nfgen_family is
ignored and all entries are used. If user-space sets the version to one
(or any other value than 0), then the new behavior is used. As version
only can have two valid values, I chose not to add a new
NFNETLINK_VERSION-constant.
Fixes: 59c08c69c2 ("netfilter: ctnetlink: Support L3 protocol-filter on flush")
Reported-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Suggested-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Kristian Evensen <kristian.evensen@gmail.com>
Tested-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
