Pablo Neira Ayuso says:
====================
Netfilter updates for net-next
1) Conntrack sets on CHECKSUM_UNNECESSARY for UDP packet with no checksum,
from Kevin Mitchell.
2) skb->priority support for nfqueue, from Nicolas Dichtel.
3) Remove conntrack extension register API, from Florian Westphal.
4) Move nat destroy hook to nf_nat_hook instead, to remove
nf_ct_ext_destroy(), also from Florian.
5) Wrap pptp conntrack NAT hooks into single structure, from Florian Westphal.
6) Support for tcp option set to noop for nf_tables, also from Florian.
7) Do not run x_tables comment match from packet path in nf_tables,
from Florian Westphal.
8) Replace spinlock by cmpxchg() loop to update missed ct event,
from Florian Westphal.
9) Wrap cttimeout hooks into single structure, from Florian.
10) Add fast nft_cmp expression for up to 16-bytes.
11) Use cb->ctx to store context in ctnetlink dump, instead of using
cb->args[], from Florian Westphal.
* git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next:
netfilter: ctnetlink: use dump structure instead of raw args
nfqueue: enable to set skb->priority
netfilter: nft_cmp: optimize comparison for 16-bytes
netfilter: cttimeout: use option structure
netfilter: ecache: don't use nf_conn spinlock
netfilter: nft_compat: suppress comment match
netfilter: exthdr: add support for tcp option removal
netfilter: conntrack: pptp: use single option structure
netfilter: conntrack: remove extension register api
netfilter: conntrack: handle ->destroy hook via nat_ops instead
netfilter: conntrack: move extension sizes into core
netfilter: conntrack: make all extensions 8-byte alignned
netfilter: nfqueue: enable to get skb->priority
netfilter: conntrack: mark UDP zero checksum as CHECKSUM_UNNECESSARY
====================
Link: https://lore.kernel.org/r/20220209133616.165104-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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>
This is a follow up of the previous patch that enables to get
skb->priority. It's now posssible to set it also.
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: Florian Westphal <fw@strlen.de>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Allow up to 16-byte comparisons with a new cmp fast version. Use two
64-bit words and calculate the mask representing the bits to be
compared. Make sure the comparison is 64-bit aligned and avoid
out-of-bound memory access on registers.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Instead of two exported functions, export a single option structure.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
For updating eache missed value we can use cmpxchg.
This also avoids need to disable BH.
kernel robot reported build failure on v1 because not all arches support
cmpxchg for u16, so extend this to u32.
This doesn't increase struct size, existing padding is used.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Replace kfree_skb() with kfree_skb_reason() in nf_hook_slow() when
skb is dropped by reason of NF_DROP. Following new drop reasons
are introduced:
SKB_DROP_REASON_NETFILTER_DROP
Signed-off-by: Menglong Dong <imagedong@tencent.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
No need to have the datapath call the always-true comment match stub.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This allows to replace a tcp option with nop padding to selectively disable
a particular tcp option.
Optstrip mode is chosen when userspace passes the exthdr expression with
neither a source nor a destination register attribute.
This is identical to xtables TCPOPTSTRIP extension.
The only difference is that TCPOPTSTRIP allows to pass in a bitmap
of options to remove rather than a single number.
Unlike TCPOPTSTRIP this expression can be used multiple times
in the same rule to get the same effect.
We could add a new nested attribute later on in case there is a
use case for single-expression-multi-remove.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Instead of exposing the four hooks individually use a sinle hook ops
structure.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
These no longer register/unregister a meaningful structure so remove it.
Cc: Paul Blakey <paulb@nvidia.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The nat module already exposes a few functions to the conntrack core.
Move the nat extension destroy hook to it.
After this, no conntrack extension needs a destroy hook.
'struct nf_ct_ext_type' and the register/unregister api can be removed
in a followup patch.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
No need to specify this in the registration modules, we already
collect all sizes for build-time checks on the maximum combined size.
After this change, all extensions except nat have no meaningful content
in their nf_ct_ext_type struct definition.
Next patch handles nat, this will then allow to remove the dynamic
register api completely.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
All extensions except one need 8 byte alignment, so just make that the
default.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The udp_error function verifies the checksum of incoming UDP packets if
one is set. This has the desirable side effect of setting skb->ip_summed
to CHECKSUM_COMPLETE, signalling that this verification need not be
repeated further up the stack.
Conversely, when the UDP checksum is empty, which is perfectly legal (at least
inside IPv4), udp_error previously left no trace that the checksum had been
deemed acceptable.
This was a problem in particular for nf_reject_ipv4, which verifies the
checksum in nf_send_unreach() before sending ICMP_DEST_UNREACH. It makes
no accommodation for zero UDP checksums unless they are already marked
as CHECKSUM_UNNECESSARY.
This commit ensures packets with empty UDP checksum are marked as
CHECKSUM_UNNECESSARY, which is explicitly recommended in skbuff.h.
Signed-off-by: Kevin Mitchell <kevmitch@arista.com>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Pablo Neira Ayuso says:
====================
Netfilter fixes for net
1) Remove leftovers from flowtable modules, from Geert Uytterhoeven.
2) Missing refcount increment of conntrack template in nft_ct,
from Florian Westphal.
3) Reduce nft_zone selftest time, also from Florian.
4) Add selftest to cover stateless NAT on fragments, from Florian Westphal.
5) Do not set net_device when for reject packets from the bridge path,
from Phil Sutter.
6) Cancel register tracking info on nft_byteorder operations.
7) Extend nft_concat_range selftest to cover set reload with no elements,
from Florian Westphal.
8) Remove useless update of pointer in chain blob builder, reported
by kbuild test robot.
* git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf:
netfilter: nf_tables: remove assignment with no effect in chain blob builder
selftests: nft_concat_range: add test for reload with no element add/del
netfilter: nft_byteorder: track register operations
netfilter: nft_reject_bridge: Fix for missing reply from prerouting
selftests: netfilter: check stateless nat udp checksum fixup
selftests: netfilter: reduce zone stress test running time
netfilter: nft_ct: fix use after free when attaching zone template
netfilter: Remove flowtable relics
====================
Link: https://lore.kernel.org/r/20220127235235.656931-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Pull networking fixes from Jakub Kicinski:
"Including fixes from netfilter and can.
Current release - new code bugs:
- tcp: add a missing sk_defer_free_flush() in tcp_splice_read()
- tcp: add a stub for sk_defer_free_flush(), fix CONFIG_INET=n
- nf_tables: set last expression in register tracking area
- nft_connlimit: fix memleak if nf_ct_netns_get() fails
- mptcp: fix removing ids bitmap setting
- bonding: use rcu_dereference_rtnl when getting active slave
- fix three cases of sleep in atomic context in drivers: lan966x, gve
- handful of build fixes for esoteric drivers after netdev->dev_addr
was made const
Previous releases - regressions:
- revert "ipv6: Honor all IPv6 PIO Valid Lifetime values", it broke
Linux compatibility with USGv6 tests
- procfs: show net device bound packet types
- ipv4: fix ip option filtering for locally generated fragments
- phy: broadcom: hook up soft_reset for BCM54616S
Previous releases - always broken:
- ipv4: raw: lock the socket in raw_bind()
- ipv4: decrease the use of shared IPID generator to decrease the
chance of attackers guessing the values
- procfs: fix cross-netns information leakage in /proc/net/ptype
- ethtool: fix link extended state for big endian
- bridge: vlan: fix single net device option dumping
- ping: fix the sk_bound_dev_if match in ping_lookup"
* tag 'net-5.17-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (86 commits)
net: bridge: vlan: fix memory leak in __allowed_ingress
net: socket: rename SKB_DROP_REASON_SOCKET_FILTER
ipv4: remove sparse error in ip_neigh_gw4()
ipv4: avoid using shared IP generator for connected sockets
ipv4: tcp: send zero IPID in SYNACK messages
ipv4: raw: lock the socket in raw_bind()
MAINTAINERS: add missing IPv4/IPv6 header paths
MAINTAINERS: add more files to eth PHY
net: stmmac: dwmac-sun8i: use return val of readl_poll_timeout()
net: bridge: vlan: fix single net device option dumping
net: stmmac: skip only stmmac_ptp_register when resume from suspend
net: stmmac: configure PTP clock source prior to PTP initialization
Revert "ipv6: Honor all IPv6 PIO Valid Lifetime values"
connector/cn_proc: Use task_is_in_init_pid_ns()
pid: Introduce helper task_is_in_init_pid_ns()
gve: Fix GFP flags when allocing pages
net: lan966x: Fix sleep in atomic context when updating MAC table
net: lan966x: Fix sleep in atomic context when injecting frames
ethernet: seeq/ether3: don't write directly to netdev->dev_addr
ethernet: 8390/etherh: don't write directly to netdev->dev_addr
...
cppcheck possible warnings:
>> net/netfilter/nf_tables_api.c:2014:2: warning: Assignment of function parameter has no effect outside the function. Did you forget dereferencing it? [uselessAssignmentPtrArg]
ptr += offsetof(struct nft_rule_dp, data);
^
Reported-by: kernel test robot <yujie.liu@intel.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Cancel tracking for byteorder operation, otherwise selector + byteorder
operation is incorrectly reduced if source and destination registers are
the same.
Reported-by: kernel test robot <oliver.sang@intel.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The conversion erroneously removed the refcount increment.
In case we can use the percpu template, we need to increment
the refcount, else it will be released when the skb gets freed.
In case the slowpath is taken, the new template already has a
refcount of 1.
Fixes: 7197743776 ("netfilter: conntrack: convert to refcount_t api")
Reported-by: kernel test robot <oliver.sang@intel.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Daniel Borkmann says:
====================
pull-request: bpf-next 2022-01-24
We've added 80 non-merge commits during the last 14 day(s) which contain
a total of 128 files changed, 4990 insertions(+), 895 deletions(-).
The main changes are:
1) Add XDP multi-buffer support and implement it for the mvneta driver,
from Lorenzo Bianconi, Eelco Chaudron and Toke Høiland-Jørgensen.
2) Add unstable conntrack lookup helpers for BPF by using the BPF kfunc
infra, from Kumar Kartikeya Dwivedi.
3) Extend BPF cgroup programs to export custom ret value to userspace via
two helpers bpf_get_retval() and bpf_set_retval(), from YiFei Zhu.
4) Add support for AF_UNIX iterator batching, from Kuniyuki Iwashima.
5) Complete missing UAPI BPF helper description and change bpf_doc.py script
to enforce consistent & complete helper documentation, from Usama Arif.
6) Deprecate libbpf's legacy BPF map definitions and streamline XDP APIs to
follow tc-based APIs, from Andrii Nakryiko.
7) Support BPF_PROG_QUERY for BPF programs attached to sockmap, from Di Zhu.
8) Deprecate libbpf's bpf_map__def() API and replace users with proper getters
and setters, from Christy Lee.
9) Extend libbpf's btf__add_btf() with an additional hashmap for strings to
reduce overhead, from Kui-Feng Lee.
10) Fix bpftool and libbpf error handling related to libbpf's hashmap__new()
utility function, from Mauricio Vásquez.
11) Add support to BTF program names in bpftool's program dump, from Raman Shukhau.
12) Fix resolve_btfids build to pick up host flags, from Connor O'Brien.
* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (80 commits)
selftests, bpf: Do not yet switch to new libbpf XDP APIs
selftests, xsk: Fix rx_full stats test
bpf: Fix flexible_array.cocci warnings
xdp: disable XDP_REDIRECT for xdp frags
bpf: selftests: add CPUMAP/DEVMAP selftests for xdp frags
bpf: selftests: introduce bpf_xdp_{load,store}_bytes selftest
net: xdp: introduce bpf_xdp_pointer utility routine
bpf: generalise tail call map compatibility check
libbpf: Add SEC name for xdp frags programs
bpf: selftests: update xdp_adjust_tail selftest to include xdp frags
bpf: test_run: add xdp_shared_info pointer in bpf_test_finish signature
bpf: introduce frags support to bpf_prog_test_run_xdp()
bpf: move user_size out of bpf_test_init
bpf: add frags support to xdp copy helpers
bpf: add frags support to the bpf_xdp_adjust_tail() API
bpf: introduce bpf_xdp_get_buff_len helper
net: mvneta: enable jumbo frames if the loaded XDP program support frags
bpf: introduce BPF_F_XDP_HAS_FRAGS flag in prog_flags loading the ebpf program
net: mvneta: add frags support to XDP_TX
xdp: add frags support to xdp_return_{buff/frame}
...
====================
Link: https://lore.kernel.org/r/20220124221235.18993-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The packet isn't invalid, REPEAT means we're trying again after cleaning
out a stale connection, e.g. via tcp tracker.
This caused increases of invalid stat counter in a test case involving
frequent connection reuse, even though no packet is actually invalid.
Fixes: 56a62e2218 ("netfilter: conntrack: fix NF_REPEAT handling")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Check if nf_ct_netns_get() fails then release the limit object
previously allocated via kmalloc().
Fixes: 37f319f37d ("netfilter: nft_connlimit: move stateful fields out of expression data")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
nft_rule_for_each_expr() sets on last to nft_rule_last(), however, this
is coming after track.last field is set on.
Use nft_expr_last() to set track.last accordingly.
Fixes: 12e4ecfa24 ("netfilter: nf_tables: add register tracking infrastructure")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The helper gets registered as 'netbios-ns', not netbios_ns.
Intentionally not adding a fixes-tag because i don't want this to go to
stable. This wasn't noticed for a very long time so no so no need to risk
regressions.
Reported-by: Yi Chen <yiche@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Commit 2c865a8a28 ("netfilter: nf_tables: add rule blob layout") never
initialized the new 'data_size' variable.
I'm not sure how it ever worked, but it might have worked almost by
accident - gcc seems to occasionally miss these kinds of 'variable used
uninitialized' situations, but I've seen it do so because it ended up
zero-initializing them due to some other simplification.
But clang is very unhappy about it all, and correctly reports
net/netfilter/nf_tables_api.c:8278:4: error: variable 'data_size' is uninitialized when used here [-Werror,-Wuninitialized]
data_size += sizeof(*prule) + rule->dlen;
^~~~~~~~~
net/netfilter/nf_tables_api.c:8263:30: note: initialize the variable 'data_size' to silence this warning
unsigned int size, data_size;
^
= 0
1 error generated.
and this fix just initializes 'data_size' to zero before the loop.
Fixes: 2c865a8a28 ("netfilter: nf_tables: add rule blob layout")
Cc: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.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>
The meta expression might mangle the packet metadata, cancel register
tracking since any metadata in the registers is stale.
Finer grain register tracking cancellation by inspecting the meta type
on the register is also possible.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The payload expression might mangle the packet, cancel register tracking
since any payload data in the registers is stale.
Finer grain register tracking cancellation by inspecting the payload
base, offset and length on the register is also possible.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Check if the destination register already contains the data that this
bitwise expression performs. This allows to skip this redundant
operation.
If the destination contains a different bitwise operation, cancel the
register tracking information. If the destination contains no bitwise
operation, update the register tracking information.
Update the payload and meta expression to check if this bitwise
operation has been already performed on the register. Hence, both the
payload/meta and the bitwise expressions are reduced.
There is also a special case: If source register != destination register
and source register is not updated by a previous bitwise operation, then
transfer selector from the source register to the destination register.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Check if the destination register already contains the data that this
meta store expression performs. This allows to skip this redundant
operation. If the destination contains a different selector, update
the register tracking information.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Check if the destination register already contains the data that this
payload store expression performs. This allows to skip this redundant
operation. If the destination contains a different selector, update
the register tracking information.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch adds new infrastructure to skip redundant selector store
operations on the same register to achieve a performance boost from
the packet path.
This is particularly noticeable in pure linear rulesets but it also
helps in rulesets which are already heaving relying in maps to avoid
ruleset linear inspection.
The idea is to keep data of the most recurrent store operations on
register to reuse them with cmp and lookup expressions.
This infrastructure allows for dynamic ruleset updates since the ruleset
blob reduction happens from the kernel.
Userspace still needs to be updated to maximize register utilization to
cooperate to improve register data reuse / reduce number of store on
register operations.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch adds a blob layout per chain to represent the ruleset in the
packet datapath.
size (unsigned long)
struct nft_rule_dp
struct nft_expr
...
struct nft_rule_dp
struct nft_expr
...
struct nft_rule_dp (is_last=1)
The new structure nft_rule_dp represents the rule in a more compact way
(smaller memory footprint) compared to the control-plane nft_rule
structure.
The ruleset blob is a read-only data structure. The first field contains
the blob size, then the rules containing expressions. There is a trailing
rule which is used by the tracing infrastructure which is equivalent to
the NULL rule marker in the previous representation. The blob size field
does not include the size of this trailing rule marker.
The ruleset blob is generated from the commit path.
This patch reuses the infrastructure available since 0cbc06b3fa
("netfilter: nf_tables: remove synchronize_rcu in commit phase") to
build the array of rules per chain.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Its the same as nf_conntrack_put(), but without the
need for an indirect call. The downside is a module dependency on
nf_conntrack, but all of these already depend on conntrack anyway.
Cc: Paul Blakey <paulb@mellanox.com>
Cc: dev@openvswitch.org
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
nf_ct_put() results in a usesless indirection:
nf_ct_put -> nf_conntrack_put -> nf_conntrack_destroy -> rcu readlock +
indirect call of ct_hooks->destroy().
There are two _put helpers:
nf_ct_put and nf_conntrack_put. The latter is what should be used in
code that MUST NOT cause a linker dependency on the conntrack module
(e.g. calls from core network stack).
Everyone else should call nf_ct_put() instead.
A followup patch will convert a few nf_conntrack_put() calls to
nf_ct_put(), in particular from modules that already have a conntrack
dependency such as act_ct or even nf_conntrack itself.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>