These two sysctls were added because the hardcoded defaults (2 minutes,
tcp, 30 seconds, udp) turned out to be too low for some setups.
They appeared in 5.14-rc1 so it should be fine to remove it again.
Marcelo convinced me that there should be no difference between a flow
that was offloaded vs. a flow that was not wrt. timeout handling.
Thus the default is changed to those for TCP established and UDP stream,
5 days and 120 seconds, respectively.
Marcelo also suggested to account for the timeout value used for the
offloading, this avoids increase beyond the value in the conntrack-sysctl
and will also instantly expire the conntrack entry with altered sysctls.
Example:
nf_conntrack_udp_timeout_stream=60
nf_flowtable_udp_timeout=60
This will remove offloaded udp flows after one minute, rather than two.
An earlier version of this patch also cleared the ASSURED bit to
allow nf_conntrack to evict the entry via early_drop (i.e., table full).
However, it looks like we can safely assume that connection timed out
via HW is still in established state, so this isn't needed.
Quoting Oz:
[..] the hardware sends all packets with a set FIN flags to sw.
[..] Connections that are aged in hardware are expected to be in the
established state.
In case it turns out that back-to-sw-path transition can occur for
'dodgy' connections too (e.g., one side disappeared while software-path
would have been in RETRANS timeout), we can adjust this later.
Cc: Oz Shlomo <ozsh@nvidia.com>
Cc: Paul Blakey <paulb@nvidia.com>
Suggested-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Reviewed-by: Oz Shlomo <ozsh@nvidia.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch adds a new sysctl tcp_ignore_invalid_rst to disable marking
out of segments RSTs as INVALID.
Signed-off-by: Ali Abdallah <aabdallah@suse.de>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
If we receive a SYN packet in original direction on an existing
connection tracking entry, we let this SYN through because conntrack
might be out-of-sync.
Conntrack gets back in sync when server responds with SYN/ACK and state
gets updated accordingly.
However, if server replies with RST, this packet might be marked as
INVALID because td_maxack value reflects the *old* conntrack state
and not the state of the originator of the RST.
Avoid td_maxack-based checks if previous packet was a SYN.
Unfortunately that is not be enough: an out of order ACK in original
direction updates last_index, so we still end up marking valid RST.
Thus disable the sequence check when we are not in established state and
the received RST has a sequence of 0.
Because marking RSTs as invalid usually leads to unwanted timeouts,
also skip RST sequence checks if a conntrack entry is already closing.
Such entries can already be evicted via GC in case the table is full.
Co-developed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Ali Abdallah <aabdallah@suse.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Consider:
client -----> conntrack ---> Host
client sends a SYN, but $Host is unreachable/silent.
Client eventually gives up and the conntrack entry will time out.
However, if the client is restarted with same addr/port pair, it
may prevent the conntrack entry from timing out.
This is noticeable when the existing conntrack entry has no NAT
transformation or an outdated one and port reuse happens either
on client or due to a NAT middlebox.
This change prevents refresh of the timeout for SYN retransmits,
so entry is going away after nf_conntrack_tcp_timeout_syn_sent
seconds (default: 60).
Entry will be re-created on next connection attempt, but then
nat rules will be evaluated again.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The packet logger backend is unable to provide the incoming (or
outgoing) interface name because that information isn't available.
Pass the hook state, it contains the network namespace, the protocol
family, the network interfaces and other things.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
TCP connections may be offloaded from nf conntrack to nf flow table.
Offloaded connections are aged after 30 seconds of inactivity.
Once aged, ownership is returned to conntrack with a hard coded pickup
time of 120 seconds, after which the connection may be deleted.
eted. The current aging intervals may be too aggressive for some users.
Provide users with the ability to control the nf flow table offload
aging and pickup time intervals via sysctl parameter as a pre-step for
configuring the nf flow table GC timeout intervals.
Signed-off-by: Oz Shlomo <ozsh@nvidia.com>
Reviewed-by: Paul Blakey <paulb@nvidia.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Several conntrack helpers and the TCP tracker assume that
skb_header_pointer() never fails based on upfront header validation.
Even if this should not ever happen, BUG_ON() is a too drastic measure,
remove them.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
log_invalid sysctl allows values of 0 to 255 inclusive so we no longer
need a range check: the min/max values can be removed.
This also removes all member variables that were moved to net_generic
data in previous patches.
This reduces size of netns_ct struct by one cache line.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The packet is not flagged as invalid: conntrack will accept it and
its associated with the conntrack entry.
This happens e.g. when receiving a retransmitted SYN in SYN_RECV state.
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>
There is no easy way to distinguish if a conntracked tcp packet is
marked invalid because of tcp_in_window() check error or because
it doesn't belong to an existing connection. With this patch,
openvswitch sets liberal tcp flag for the established sessions so
that out of window packets are not marked invalid.
A helper function - nf_ct_set_tcp_be_liberal(nf_conn) is added which
sets this flag for both the directions of the nf_conn.
Suggested-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Numan Siddique <nusiddiq@redhat.com>
Acked-by: Florian Westphal <fw@strlen.de>
Link: https://lore.kernel.org/r/20201116130126.3065077-1-nusiddiq@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
If the first packet conntrack sees after a re-register is an outgoing
keepalive packet with no data (SEG.SEQ = SND.NXT-1), td_end is set to
SND.NXT-1.
When the peer correctly acknowledges SND.NXT, tcp_in_window fails
check III (Upper bound for valid (s)ack: sack <= receiver.td_end) and
returns false, which cascades into nf_conntrack_in setting
skb->_nfct = 0 and in later conntrack iptables rules not matching.
In cases where iptables are dropping packets that do not match
conntrack rules this can result in idle tcp connections to time out.
v2: adjust td_end when getting the reply rather than when sending out
the keepalive packet.
Fixes: f94e63801a ("netfilter: conntrack: reset tcp maxwin on re-register")
Signed-off-by: Francesco Ruggeri <fruggeri@arista.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Drop duplicated words in net/netfilter/ and net/ipv4/netfilter/.
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Jakub Jankowski reported following oddity:
After 3 way handshake completes, timeout of new connection is set to
max_retrans (300s) instead of established (5 days).
shortened excerpt from pcap provided:
25.070622 IP (flags [DF], proto TCP (6), length 52)
10.8.5.4.1025 > 10.8.1.2.80: Flags [S], seq 11, win 64240, [wscale 8]
26.070462 IP (flags [DF], proto TCP (6), length 48)
10.8.1.2.80 > 10.8.5.4.1025: Flags [S.], seq 82, ack 12, win 65535, [wscale 3]
27.070449 IP (flags [DF], proto TCP (6), length 40)
10.8.5.4.1025 > 10.8.1.2.80: Flags [.], ack 83, win 512, length 0
Turns out the last_win is of u16 type, but we store the scaled value:
512 << 8 (== 0x20000) becomes 0 window.
The Fixes tag is not correct, as the bug has existed forever, but
without that change all that this causes might cause is to mistake a
window update (to-nonzero-from-zero) for a retransmit.
Fixes: fbcd253d24 ("netfilter: conntrack: lower timeout to RETRANS seconds if window is 0")
Reported-by: Jakub Jankowski <shasta@toxcorp.com>
Tested-by: Jakub Jankowski <shasta@toxcorp.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Resolve conflict between d2912cb15b ("treewide: Replace GPLv2
boilerplate/reference with SPDX - rule 500") removing the GPL disclaimer
and fe03d47456 ("Update my email address") which updates Jozsef
Kadlecsik's email.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Based on 2 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation #
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 4122 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
It's better to use my kadlec@netfilter.org email address in
the source code. I might not be able to use
kadlec@blackhole.kfki.hu in the future.
Signed-off-by: Jozsef Kadlecsik <kadlec@netfilter.org>
Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
We currently have two levels of strict validation:
1) liberal (default)
- undefined (type >= max) & NLA_UNSPEC attributes accepted
- attribute length >= expected accepted
- garbage at end of message accepted
2) strict (opt-in)
- NLA_UNSPEC attributes accepted
- attribute length >= expected accepted
Split out parsing strictness into four different options:
* TRAILING - check that there's no trailing data after parsing
attributes (in message or nested)
* MAXTYPE - reject attrs > max known type
* UNSPEC - reject attributes with NLA_UNSPEC policy entries
* STRICT_ATTRS - strictly validate attribute size
The default for future things should be *everything*.
The current *_strict() is a combination of TRAILING and MAXTYPE,
and is renamed to _deprecated_strict().
The current regular parsing has none of this, and is renamed to
*_parse_deprecated().
Additionally it allows us to selectively set one of the new flags
even on old policies. Notably, the UNSPEC flag could be useful in
this case, since it can be arranged (by filling in the policy) to
not be an incompatible userspace ABI change, but would then going
forward prevent forgetting attribute entries. Similar can apply
to the POLICY flag.
We end up with the following renames:
* nla_parse -> nla_parse_deprecated
* nla_parse_strict -> nla_parse_deprecated_strict
* nlmsg_parse -> nlmsg_parse_deprecated
* nlmsg_parse_strict -> nlmsg_parse_deprecated_strict
* nla_parse_nested -> nla_parse_nested_deprecated
* nla_validate_nested -> nla_validate_nested_deprecated
Using spatch, of course:
@@
expression TB, MAX, HEAD, LEN, POL, EXT;
@@
-nla_parse(TB, MAX, HEAD, LEN, POL, EXT)
+nla_parse_deprecated(TB, MAX, HEAD, LEN, POL, EXT)
@@
expression NLH, HDRLEN, TB, MAX, POL, EXT;
@@
-nlmsg_parse(NLH, HDRLEN, TB, MAX, POL, EXT)
+nlmsg_parse_deprecated(NLH, HDRLEN, TB, MAX, POL, EXT)
@@
expression NLH, HDRLEN, TB, MAX, POL, EXT;
@@
-nlmsg_parse_strict(NLH, HDRLEN, TB, MAX, POL, EXT)
+nlmsg_parse_deprecated_strict(NLH, HDRLEN, TB, MAX, POL, EXT)
@@
expression TB, MAX, NLA, POL, EXT;
@@
-nla_parse_nested(TB, MAX, NLA, POL, EXT)
+nla_parse_nested_deprecated(TB, MAX, NLA, POL, EXT)
@@
expression START, MAX, POL, EXT;
@@
-nla_validate_nested(START, MAX, POL, EXT)
+nla_validate_nested_deprecated(START, MAX, POL, EXT)
@@
expression NLH, HDRLEN, MAX, POL, EXT;
@@
-nlmsg_validate(NLH, HDRLEN, MAX, POL, EXT)
+nlmsg_validate_deprecated(NLH, HDRLEN, MAX, POL, EXT)
For this patch, don't actually add the strict, non-renamed versions
yet so that it breaks compile if I get it wrong.
Also, while at it, make nla_validate and nla_parse go down to a
common __nla_validate_parse() function to avoid code duplication.
Ultimately, this allows us to have very strict validation for every
new caller of nla_parse()/nlmsg_parse() etc as re-introduced in the
next patch, while existing things will continue to work as is.
In effect then, this adds fully strict validation for any new command.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Even if the NLA_F_NESTED flag was introduced more than 11 years ago, most
netlink based interfaces (including recently added ones) are still not
setting it in kernel generated messages. Without the flag, message parsers
not aware of attribute semantics (e.g. wireshark dissector or libmnl's
mnl_nlmsg_fprintf()) cannot recognize nested attributes and won't display
the structure of their contents.
Unfortunately we cannot just add the flag everywhere as there may be
userspace applications which check nlattr::nla_type directly rather than
through a helper masking out the flags. Therefore the patch renames
nla_nest_start() to nla_nest_start_noflag() and introduces nla_nest_start()
as a wrapper adding NLA_F_NESTED. The calls which add NLA_F_NESTED manually
are rewritten to use nla_nest_start().
Except for changes in include/net/netlink.h, the patch was generated using
this semantic patch:
@@ expression E1, E2; @@
-nla_nest_start(E1, E2)
+nla_nest_start_noflag(E1, E2)
@@ expression E1, E2; @@
-nla_nest_start_noflag(E1, E2 | NLA_F_NESTED)
+nla_nest_start(E1, E2)
Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
TCP resets cause instant transition from established to closed state
provided the reset is in-window. Endpoints that implement RFC 5961
require resets to match the next expected sequence number.
RST segments that are in-window (but that do not match RCV.NXT) are
ignored, and a "challenge ACK" is sent back.
Main problem for conntrack is that its a middlebox, i.e. whereas an end
host might have ACK'd SEQ (and would thus accept an RST with this
sequence number), conntrack might not have seen this ACK (yet).
Therefore we can't simply flag RSTs with non-exact match as invalid.
This updates RST processing as follows:
1. If the connection is in a state other than ESTABLISHED, nothing is
changed, RST is subject to normal in-window check.
2. If the RSTs sequence number either matches exactly RCV.NXT,
connection state moves to CLOSE.
3. The same applies if the RST sequence number aligns with a previous
packet in the same direction.
In all other cases, the connection remains in ESTABLISHED state.
If the normal-in-window check passes, the timeout will be lowered
to that of CLOSE.
If the peer sends a challenge ack, connection timeout will be reset.
If the challenge ACK triggers another RST (RST was valid after all),
this 2nd RST will match expected sequence and conntrack state changes to
CLOSE.
If no challenge ACK is received, the connection will time out after
CLOSE seconds (10 seconds by default), just like without this patch.
Packetdrill test case:
0.000 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
0.000 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
0.000 bind(3, ..., ...) = 0
0.000 listen(3, 1) = 0
0.100 < S 0:0(0) win 32792 <mss 1460,sackOK,nop,nop,nop,wscale 7>
0.100 > S. 0:0(0) ack 1 win 64240 <mss 1460,nop,nop,sackOK,nop,wscale 7>
0.200 < . 1:1(0) ack 1 win 257
0.200 accept(3, ..., ...) = 4
// Receive a segment.
0.210 < P. 1:1001(1000) ack 1 win 46
0.210 > . 1:1(0) ack 1001
// Application writes 1000 bytes.
0.250 write(4, ..., 1000) = 1000
0.250 > P. 1:1001(1000) ack 1001
// First reset, old sequence. Conntrack (correctly) considers this
// invalid due to failed window validation (regardless of this patch).
0.260 < R 2:2(0) ack 1001 win 260
// 2nd reset, but too far ahead sequence. Same: correctly handled
// as invalid.
0.270 < R 99990001:99990001(0) ack 1001 win 260
// in-window, but not exact sequence.
// Current Linux kernels might reply with a challenge ack, and do not
// remove connection.
// Without this patch, conntrack state moves to CLOSE.
// With patch, timeout is lowered like CLOSE, but connection stays
// in ESTABLISHED state.
0.280 < R 1010:1010(0) ack 1001 win 260
// Expect challenge ACK
0.281 > . 1001:1001(0) ack 1001 win 501
// With or without this patch, RST will cause connection
// to move to CLOSE (sequence number matches)
// 0.282 < R 1001:1001(0) ack 1001 win 260
// ACK
0.300 < . 1001:1001(0) ack 1001 win 257
// more data could be exchanged here, connection
// is still established
// Client closes the connection.
0.610 < F. 1001:1001(0) ack 1001 win 260
0.650 > . 1001:1001(0) ack 1002
// Close the connection without reading outstanding data
0.700 close(4) = 0
// so one more reset. Will be deemed acceptable with patch as well:
// connection is already closing.
0.701 > R. 1001:1001(0) ack 1002 win 501
// End packetdrill test case.
With patch, this generates following conntrack events:
[NEW] 120 SYN_SENT src=10.0.2.1 dst=10.0.0.1 sport=5437 dport=80 [UNREPLIED]
[UPDATE] 60 SYN_RECV src=10.0.2.1 dst=10.0.0.1 sport=5437 dport=80
[UPDATE] 432000 ESTABLISHED src=10.0.2.1 dst=10.0.0.1 sport=5437 dport=80 [ASSURED]
[UPDATE] 120 FIN_WAIT src=10.0.2.1 dst=10.0.0.1 sport=5437 dport=80 [ASSURED]
[UPDATE] 60 CLOSE_WAIT src=10.0.2.1 dst=10.0.0.1 sport=5437 dport=80 [ASSURED]
[UPDATE] 10 CLOSE src=10.0.2.1 dst=10.0.0.1 sport=5437 dport=80 [ASSURED]
Without patch, first RST moves connection to close, whereas socket state
does not change until FIN is received.
[NEW] 120 SYN_SENT src=10.0.2.1 dst=10.0.0.1 sport=5141 dport=80 [UNREPLIED]
[UPDATE] 60 SYN_RECV src=10.0.2.1 dst=10.0.0.1 sport=5141 dport=80
[UPDATE] 432000 ESTABLISHED src=10.0.2.1 dst=10.0.0.1 sport=5141 dport=80 [ASSURED]
[UPDATE] 10 CLOSE src=10.0.2.1 dst=10.0.0.1 sport=5141 dport=80 [ASSURED]
Cc: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Those were needed we still had modular trackers.
As we don't have those anymore, prefer direct calls and remove all
the (un)register infrastructure associated with this.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Due to historical reasons, all l4 trackers register their own
sysctls.
This leads to copy&pasted boilerplate code, that does exactly same
thing, just with different data structure.
Place all of this in a single file.
This allows to remove the various ctl_table pointers from the ct_netns
structure and reduces overall code size.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The l4 protocol trackers are invoked via indirect call: l4proto->packet().
With one exception (gre), all l4trackers are builtin, so we can make
.packet optional and use a direct call for most protocols.
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 your net-next tree:
1) Support for matching on ipsec policy already set in the route, from
Florian Westphal.
2) Split set destruction into deactivate and destroy phase to make it
fit better into the transaction infrastructure, also from Florian.
This includes a patch to warn on imbalance when setting the new
activate and deactivate interfaces.
3) Release transaction list from the workqueue to remove expensive
synchronize_rcu() from configuration plane path. This speeds up
configuration plane quite a bit. From Florian Westphal.
4) Add new xfrm/ipsec extension, this new extension allows you to match
for ipsec tunnel keys such as source and destination address, spi and
reqid. From Máté Eckl and Florian Westphal.
5) Add secmark support, this includes connsecmark too, patches
from Christian Gottsche.
6) Allow to specify remaining bytes in xt_quota, from Chenbo Feng.
One follow up patch to calm a clang warning for this one, from
Nathan Chancellor.
7) Flush conntrack entries based on layer 3 family, from Kristian Evensen.
8) New revision for cgroups2 to shrink the path field.
9) Get rid of obsolete need_conntrack(), as a result from recent
demodularization works.
10) Use WARN_ON instead of BUG_ON, from Florian Westphal.
11) Unused exported symbol in nf_nat_ipv4_fn(), from Florian.
12) Remove superfluous check for timeout netlink parser and dump
functions in layer 4 conntrack helpers.
13) Unnecessary redundant rcu read side locks in NAT redirect,
from Taehee Yoo.
14) Pass nf_hook_state structure to error handlers, patch from
Florian Westphal.
15) Remove ->new() interface from layer 4 protocol trackers. Place
them in the ->packet() interface. From Florian.
16) Place conntrack ->error() handling in the ->packet() interface.
Patches from Florian Westphal.
17) Remove unused parameter in the pernet initialization path,
also from Florian.
18) Remove additional parameter to specify layer 3 protocol when
looking up for protocol tracker. From Florian.
19) Shrink array of layer 4 protocol trackers, from Florian.
20) Check for linear skb only once from the ALG NAT mangling
codebase, from Taehee Yoo.
21) Use rhashtable_walk_enter() instead of deprecated
rhashtable_walk_init(), also from Taehee.
22) No need to flush all conntracks when only one single address
is gone, from Tan Hu.
23) Remove redundant check for NAT flags in flowtable code, from
Taehee Yoo.
24) Use rhashtable_lookup() instead of rhashtable_lookup_fast()
from netfilter codebase, since rcu read lock side is already
assumed in this path.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
sizeof(sizeof()) is quite strange and does not seem to be what
is wanted here.
The issue is detected with the help of Coccinelle.
Fixes: 3921584674 ("netfilter: conntrack: remove nlattr_size pointer from l4proto trackers")
Signed-off-by: zhong jiang <zhongjiang@huawei.com>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
l4 protocols are demuxed by l3num, l4num pair.
However, almost all l4 trackers are l3 agnostic.
Only exceptions are:
- gre, icmp (ipv4 only)
- icmpv6 (ipv6 only)
This commit gets rid of the l3 mapping, l4 trackers can now be looked up
by their IPPROTO_XXX value alone, which gets rid of the additional l3
indirection.
For icmp, ipcmp6 and gre, add a check on state->pf and
return -NF_ACCEPT in case we're asked to track e.g. icmpv6-in-ipv4,
this seems more fitting than using the generic tracker.
Additionally we can kill the 2nd l4proto definitions that were needed
for v4/v6 split -- they are now the same so we can use single l4proto
struct for each protocol, rather than two.
The EXPORT_SYMBOLs can be removed as all these object files are
part of nf_conntrack with no external references.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Its unused, next patch will remove l4proto->l3proto number to simplify
l4 protocol demuxer lookup.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The error() handler gets called before allocating or looking up a
connection tracking entry.
We can instead use direct calls from the ->packet() handlers which get
invoked for every packet anyway.
Only exceptions are icmp and icmpv6, these two special cases will be
handled in the next patch.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Only two protocols need the ->error() function: icmp and icmpv6.
This is because icmp error mssages might be RELATED to an existing
connection (e.g. PMTUD, port unreachable and the like), and their
->error() handlers do this.
The error callback is already optional, so remove it for
udp and call them from ->packet() instead.
As the error() callback can call checksum functions that write to
skb->csum*, the const qualifier has to be removed as well.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
->new() gets invoked after ->error() and before ->packet() if
a conntrack lookup has found no result for the tuple.
We can fold it into ->packet() -- the packet() implementations
can check if the conntrack is confirmed (new) or not
(already in hash).
If its unconfirmed, the conntrack isn't in the hash yet so current
skb created a new conntrack entry.
Only relevant side effect -- if packet() doesn't return NF_ACCEPT
but -NF_ACCEPT (or drop), while the conntrack was just created,
then the newly allocated conntrack is freed right away, rather than not
created in the first place.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
nf_hook_state contains all the hook meta-information: netns, protocol family,
hook location, and so on.
Instead of only passing selected information, pass a pointer to entire
structure.
This will allow to merge the error and the packet handlers and remove
the ->new() function in followup patches.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Now that cttimeout support for nft_ct is in place, these should depend
on CONFIG_NF_CONNTRACK_TIMEOUT otherwise we can crash when dumping the
policy if this option is not enabled.
[ 71.600121] BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
[...]
[ 71.600141] CPU: 3 PID: 7612 Comm: nft Not tainted 4.18.0+ #246
[...]
[ 71.600188] Call Trace:
[ 71.600201] ? nft_ct_timeout_obj_dump+0xc6/0xf0 [nft_ct]
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
tcp, sctp and dccp trackers re-use the userspace ctnetlink states
to index their timeout arrays, which means timeout[0] is never
used. Copy the 'new' state (syn-sent, dccp-request, ..) to 0 as well
so external users can simply read it off timeouts[0] without need to
differentiate dccp/sctp/tcp and udp/icmp/gre/generic.
The alternative is to map all array accesses to 'i - 1', but that
is a much more intrusive change.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Not needed, we can have the l4trackers fetch it themselvs.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Handle common protocols (udp, tcp, ..), in the core and only
do the call if needed by the l4proto tracker.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Handle the common cases (tcp, udp, etc). in the core and only
do the indirect call for the protocols that need it (GRE for instance).
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Dominique Martinet reported a TCP hang problem when simultaneous open was used.
The problem is that the tcp_conntracks state table is not smart enough
to handle the case. The state table could be fixed by introducing a new state,
but that would require more lines of code compared to this patch, due to the
required backward compatibility with ctnetlink.
Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Reported-by: Dominique Martinet <asmadeus@codewreck.org>
Tested-by: Dominique Martinet <asmadeus@codewreck.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This new bit tells us that the conntrack entry is owned by the flow
table offload infrastructure.
# cat /proc/net/nf_conntrack
ipv4 2 tcp 6 src=10.141.10.2 dst=147.75.205.195 sport=36392 dport=443 src=147.75.205.195 dst=192.168.2.195 sport=443 dport=36392 [OFFLOAD] mark=0 zone=0 use=2
Note the [OFFLOAD] tag in the listing.
The timer of such conntrack entries look like stopped from userspace.
In practise, to make sure the conntrack entry does not go away, the
conntrack timer is periodically set to an arbitrary large value that
gets refreshed on every iteration from the garbage collector, so it
never expires- and they display no internal state in the case of TCP
flows. This allows us to save a bitcheck from the packet path via
nf_ct_is_expired().
Conntrack entries that have been offloaded to the flow table
infrastructure cannot be deleted/flushed via ctnetlink. The flow table
infrastructure is also responsible for releasing this conntrack entry.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Nowadays this is just the default template that is used when setting up
the net namespace, so nothing writes to these locations.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
previous patches removed all writes to these structs so we can
now mark them as const.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
similar to previous commit, but instead compute this at compile time
and turn nlattr_size into an u16.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
When zero window is announced we can get into a situation where
connection stays around forever:
1. One side announces zero window.
2. Other side closes.
In this case, no FIN is sent (stuck in send queue).
Unless other side opens the window up again conntrack
stays in ESTABLISHED state for a very long time.
Lets alleviate this by lowering the timeout to RETRANS (5 minutes),
the other end should be sending zero window probes to keep the
connection established as long as a socket still exists.
Cc: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
We currently call ->nlattr_tuple_size() once at register time and
cache result in l4proto->nla_size.
nla_size is the only member that is written to, avoiding this would
allow to make l4proto trackers const.
We can use ->nlattr_tuple_size() at run time, and cache result in
the individual trackers instead.
This is an intermediate step, next patch removes nlattr_size()
callback and computes size at compile time, then removes nla_size.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
We currently pass down the l4 protocol to the conntrack ->packet()
function, but the only user of this is the debug info decision.
Same information can be derived from struct nf_conn.
Add a wrapper for the previous patch that extracs the information
from nf_conn and passes it to nf_l4proto_log_invalid().
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
We currently pass down the l4 protocol to the conntrack ->packet()
function, but the only user of this is the debug info decision.
Same information can be derived from struct nf_conn.
As a first step, add and use a new log function for this, similar to
nf_ct_helper_log().
Add __cold annotation -- invalid packets should be infrequent so
gcc can consider all call paths that lead to such a function as
unlikely.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
