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182 Commits (9d39d86cd4af2b17b970d63307daad71f563d207)

Author SHA1 Message Date
yangxingwu 7e59b3fea2 netfilter: remove unnecessary spaces
This patch removes extra spaces.

Signed-off-by: yangxingwu <xingwu.yang@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-08-13 12:08:48 +02:00
Florian Westphal 959b69ef57 netfilter: conntrack: always store window size un-scaled
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>
2019-07-16 13:17:02 +02:00
Pablo Neira Ayuso 1c5ba67d22 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
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>
2019-06-25 01:32:59 +02:00
Thomas Gleixner d2912cb15b treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500
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>
2019-06-19 17:09:55 +02:00
Jozsef Kadlecsik fe03d47456 Update my email address
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>
2019-06-10 13:00:24 +02:00
Johannes Berg 8cb081746c netlink: make validation more configurable for future strictness
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>
2019-04-27 17:07:21 -04:00
Michal Kubecek ae0be8de9a netlink: make nla_nest_start() add NLA_F_NESTED flag
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>
2019-04-27 17:03:44 -04:00
Florian Westphal be0502a3f2 netfilter: conntrack: tcp: only close if RST matches exact sequence
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>
2019-03-01 14:19:31 +01:00
Florian Westphal 2a389de86e netfilter: conntrack: remove l4proto init and get_net callbacks
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>
2019-01-18 15:02:34 +01:00
Florian Westphal b884fa4617 netfilter: conntrack: unify sysctl handling
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>
2019-01-18 15:02:34 +01:00
Florian Westphal a47c540481 netfilter: conntrack: handle builtin l4proto packet functions via direct calls
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>
2019-01-18 15:02:33 +01:00
Pablo Neira Ayuso a95a7774d5 netfilter: conntrack: add nf_{tcp,udp,sctp,icmp,dccp,icmpv6,generic}_pernet()
Expose these functions to access conntrack protocol tracker netns area,
nfnetlink_cttimeout needs this.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-11-03 13:28:02 +01:00
David S. Miller 9000a457a0 Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next
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>
2018-10-08 21:28:55 -07:00
zhong jiang 346fa83d10 netfilter: conntrack: get rid of double sizeof
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>
2018-09-20 18:40:32 +02:00
Florian Westphal dd2934a957 netfilter: conntrack: remove l3->l4 mapping information
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>
2018-09-20 18:07:35 +02:00
Florian Westphal ca2ca6e1c0 netfilter: conntrack: remove unused proto arg from netns init functions
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>
2018-09-20 18:03:50 +02:00
Florian Westphal 0150ffbac7 netfilter: conntrack: avoid using ->error callback if possible
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>
2018-09-20 18:02:42 +02:00
Florian Westphal 83d213fd9d netfilter: conntrack: deconstify packet callback skb pointer
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>
2018-09-20 18:02:22 +02:00
Florian Westphal 9976fc6e6e netfilter: conntrack: remove the l4proto->new() function
->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>
2018-09-20 17:57:17 +02:00
Florian Westphal 93e66024b0 netfilter: conntrack: pass nf_hook_state to packet and error handlers
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>
2018-09-20 17:54:37 +02:00
Pablo Neira Ayuso a874752a10 netfilter: conntrack: timeout interface depend on CONFIG_NF_CONNTRACK_TIMEOUT
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>
2018-09-11 01:30:25 +02:00
Florian Westphal ef39078d63 netfilter: conntrack: place 'new' timeout in first location too
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>
2018-08-29 13:04:38 +02:00
Florian Westphal c779e84960 netfilter: conntrack: remove get_timeout() indirection
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>
2018-07-16 17:55:01 +02:00
Florian Westphal 97e08caec3 netfilter: conntrack: avoid l4proto pkt_to_tuple calls
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>
2018-07-16 17:55:01 +02:00
Florian Westphal 8b3892ea87 netfilter: conntrack: avoid calls to l4proto invert_tuple
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>
2018-07-16 17:55:00 +02:00
Jozsef Kadlecsik 72d4d3e398 netfilter: Fix handling simultaneous open in TCP conntrack
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>
2018-04-27 00:39:29 +02:00
Pablo Neira Ayuso 90964016e5 netfilter: nf_conntrack: add IPS_OFFLOAD status bit
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>
2018-01-08 18:11:05 +01:00
Florian Westphal 2c9e8637ea netfilter: conntrack: timeouts can be const
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>
2018-01-08 18:01:02 +01:00
Florian Westphal 9dae47aba0 netfilter: conntrack: l4 protocol trackers can be const
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>
2018-01-08 18:00:54 +01:00
Florian Westphal 3921584674 netfilter: conntrack: remove nlattr_size pointer from l4proto trackers
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>
2018-01-08 16:47:14 +01:00
Florian Westphal fbcd253d24 netfilter: conntrack: lower timeout to RETRANS seconds if window is 0
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>
2017-11-20 13:30:24 +01:00
Florian Westphal 5caaed151a netfilter: conntrack: don't cache nlattr_tuple_size result in nla_size
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>
2017-11-06 16:48:38 +01:00
Florian Westphal eb6fad5a4a netfilter: conntrack: remove pf argument from l4 packet functions
not needed/used anymore.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-10-24 18:01:49 +02:00
Florian Westphal 3d0b527bc9 netfilter: conntrack: add and use nf_ct_l4proto_log_invalid
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>
2017-10-24 18:01:49 +02:00
Florian Westphal c4f3db1595 netfilter: conntrack: add and use nf_l4proto_log_invalid
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>
2017-10-24 18:01:49 +02:00
Florian Westphal d1c1e39de8 netfilter: remove unused hooknum arg from packet functions
tested with allmodconfig build.

Signed-off-by: Florian Westphal <fw@strlen.de>
2017-09-04 13:25:18 +02:00
Florian Westphal ea48cc83cf netfilter: conntrack: print_conntrack only needed if CONFIG_NF_CONNTRACK_PROCFS
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-08-24 18:52:33 +02:00
Florian Westphal 91950833dd netfilter: conntrack: place print_tuple in procfs part
CONFIG_NF_CONNTRACK_PROCFS is deprecated, no need to use a function
pointer in the trackers for this. Place the printf formatting in
the one place that uses it.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-08-24 18:52:32 +02:00
Florian Westphal 09ec82f5af netfilter: conntrack: remove protocol name from l4proto struct
no need to waste storage for something that is only needed
in one place and can be deduced from protocol number.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-08-24 18:52:32 +02:00
David S. Miller a01aa920b8 Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next
Pablo Neira Ayuso says:

====================
Netfilter/IPVS updates for net-next

The following patchset contains Netfilter updates for your net-next
tree. A large bunch of code cleanups, simplify the conntrack extension
codebase, get rid of the fake conntrack object, speed up netns by
selective synchronize_net() calls. More specifically, they are:

1) Check for ct->status bit instead of using nfct_nat() from IPVS and
   Netfilter codebase, patch from Florian Westphal.

2) Use kcalloc() wherever possible in the IPVS code, from Varsha Rao.

3) Simplify FTP IPVS helper module registration path, from Arushi Singhal.

4) Introduce nft_is_base_chain() helper function.

5) Enforce expectation limit from userspace conntrack helper,
   from Gao Feng.

6) Add nf_ct_remove_expect() helper function, from Gao Feng.

7) NAT mangle helper function return boolean, from Gao Feng.

8) ctnetlink_alloc_expect() should only work for conntrack with
   helpers, from Gao Feng.

9) Add nfnl_msg_type() helper function to nfnetlink to build the
   netlink message type.

10) Get rid of unnecessary cast on void, from simran singhal.

11) Use seq_puts()/seq_putc() instead of seq_printf() where possible,
    also from simran singhal.

12) Use list_prev_entry() from nf_tables, from simran signhal.

13) Remove unnecessary & on pointer function in the Netfilter and IPVS
    code.

14) Remove obsolete comment on set of rules per CPU in ip6_tables,
    no longer true. From Arushi Singhal.

15) Remove duplicated nf_conntrack_l4proto_udplite4, from Gao Feng.

16) Remove unnecessary nested rcu_read_lock() in
    __nf_nat_decode_session(). Code running from hooks are already
    guaranteed to run under RCU read side.

17) Remove deadcode in nf_tables_getobj(), from Aaron Conole.

18) Remove double assignment in nf_ct_l4proto_pernet_unregister_one(),
    also from Aaron.

19) Get rid of unsed __ip_set_get_netlink(), from Aaron Conole.

20) Don't propagate NF_DROP error to userspace via ctnetlink in
    __nf_nat_alloc_null_binding() function, from Gao Feng.

21) Revisit nf_ct_deliver_cached_events() to remove unnecessary checks,
    from Gao Feng.

22) Kill the fake untracked conntrack objects, use ctinfo instead to
    annotate a conntrack object is untracked, from Florian Westphal.

23) Remove nf_ct_is_untracked(), now obsolete since we have no
    conntrack template anymore, from Florian.

24) Add event mask support to nft_ct, also from Florian.

25) Move nf_conn_help structure to
    include/net/netfilter/nf_conntrack_helper.h.

26) Add a fixed 32 bytes scratchpad area for conntrack helpers.
    Thus, we don't deal with variable conntrack extensions anymore.
    Make sure userspace conntrack helper doesn't go over that size.
    Remove variable size ct extension infrastructure now this code
    got no more clients. From Florian Westphal.

27) Restore offset and length of nf_ct_ext structure to 8 bytes now
    that wraparound is not possible any longer, also from Florian.

28) Allow to get rid of unassured flows under stress in conntrack,
    this applies to DCCP, SCTP and TCP protocols, from Florian.

29) Shrink size of nf_conntrack_ecache structure, from Florian.

30) Use TCP_MAX_WSCALE instead of hardcoded 14 in TCP tracker,
    from Gao Feng.

31) Register SYNPROXY hooks on demand, from Florian Westphal.

32) Use pernet hook whenever possible, instead of global hook
    registration, from Florian Westphal.

33) Pass hook structure to ebt_register_table() to consolidate some
    infrastructure code, from Florian Westphal.

34) Use consume_skb() and return NF_STOLEN, instead of NF_DROP in the
    SYNPROXY code, to make sure device stats are not fooled, patch
    from Gao Feng.

35) Remove NF_CT_EXT_F_PREALLOC this kills quite some code that we
    don't need anymore if we just select a fixed size instead of
    expensive runtime time calculation of this. From Florian.

36) Constify nf_ct_extend_register() and nf_ct_extend_unregister(),
    from Florian.

37) Simplify nf_ct_ext_add(), this kills nf_ct_ext_create(), from
    Florian.

38) Attach NAT extension on-demand from masquerade and pptp helper
    path, from Florian.

39) Get rid of useless ip_vs_set_state_timeout(), from Aaron Conole.

40) Speed up netns by selective calls of synchronize_net(), from
    Florian Westphal.

41) Silence stack size warning gcc in 32-bit arch in snmp helper,
    from Florian.

42) Inconditionally call nf_ct_ext_destroy(), even if we have no
    extensions, to deal with the NF_NAT_MANIP_SRC case. Patch from
    Liping Zhang.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-01 10:47:53 -04:00
Gao Feng 122868b378 netfilter: tcp: Use TCP_MAX_WSCALE instead of literal 14
The window scale may be enlarged from 14 to 15 according to the itef
draft https://tools.ietf.org/html/draft-nishida-tcpm-maxwin-03.

Use the macro TCP_MAX_WSCALE to support it easily with TCP stack in
the future.

Signed-off-by: Gao Feng <fgao@ikuai8.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-04-19 17:55:17 +02:00
Florian Westphal c6dd940b1f netfilter: allow early drop of assured conntracks
If insertion of a new conntrack fails because the table is full, the kernel
searches the next buckets of the hash slot where the new connection
was supposed to be inserted at for an entry that hasn't seen traffic
in reply direction (non-assured), if it finds one, that entry is
is dropped and the new connection entry is allocated.

Allow the conntrack gc worker to also remove *assured* conntracks if
resources are low.

Do this by querying the l4 tracker, e.g. tcp connections are now dropped
if they are no longer established (e.g. in finwait).

This could be refined further, e.g. by adding 'soft' established timeout
(i.e., a timeout that is only used once we get close to resource
exhaustion).

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>
2017-04-19 17:55:17 +02:00
Johannes Berg fceb6435e8 netlink: pass extended ACK struct to parsing functions
Pass the new extended ACK reporting struct to all of the generic
netlink parsing functions. For now, pass NULL in almost all callers
(except for some in the core.)

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-13 13:58:22 -04:00
Florian Westphal 11df4b760f netfilter: conntrack: no need to pass ctinfo to error handler
It is never accessed for reading and the only places that write to it
are the icmp(6) handlers, which also set skb->nfct (and skb->nfctinfo).

The conntrack core specifically checks for attached skb->nfct after
->error() invocation and returns early in this case.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-02-02 14:31:51 +01:00
Pablo Neira Ayuso adf0516845 netfilter: remove ip_conntrack* sysctl compat code
This backward compatibility has been around for more than ten years,
since Yasuyuki Kozakai introduced IPv6 in conntrack. These days, we have
alternate /proc/net/nf_conntrack* entries, the ctnetlink interface and
the conntrack utility got adopted by many people in the user community
according to what I observed on the netfilter user mailing list.

So let's get rid of this.

Note that nf_conntrack_htable_size and unsigned int nf_conntrack_max do
not need to be exported as symbol anymore.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-08-13 13:27:13 +02:00
Gao Feng e5e693ab49 netfilter: conntrack: Only need first 4 bytes to get l4proto ports
We only need first 4 bytes instead of 8 bytes to get the ports of
tcp/udp/dccp/sctp/udplite in their pkt_to_tuple function.

Signed-off-by: Gao Feng <fgao@ikuai8.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-08-12 00:41:08 +02:00
David S. Miller 11afbff861 Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next
Pablo Neira Ayuso says:

====================
Netfilter updates for net-next

The following patchset contains Netfilter updates for your net-next
tree, mostly from Florian Westphal to sort out the lack of sufficient
validation in x_tables and connlabel preparation patches to add
nf_tables support. They are:

1) Ensure we don't go over the ruleset blob boundaries in
   mark_source_chains().

2) Validate that target jumps land on an existing xt_entry. This extra
   sanitization comes with a performance penalty when loading the ruleset.

3) Introduce xt_check_entry_offsets() and use it from {arp,ip,ip6}tables.

4) Get rid of the smallish check_entry() functions in {arp,ip,ip6}tables.

5) Make sure the minimal possible target size in x_tables.

6) Similar to #3, add xt_compat_check_entry_offsets() for compat code.

7) Check that standard target size is valid.

8) More sanitization to ensure that the target_offset field is correct.

9) Add xt_check_entry_match() to validate that matches are well-formed.

10-12) Three patch to reduce the number of parameters in
    translate_compat_table() for {arp,ip,ip6}tables by using a container
    structure.

13) No need to return value from xt_compat_match_from_user(), so make
    it void.

14) Consolidate translate_table() so it can be used by compat code too.

15) Remove obsolete check for compat code, so we keep consistent with
    what was already removed in the native layout code (back in 2007).

16) Get rid of target jump validation from mark_source_chains(),
    obsoleted by #2.

17) Introduce xt_copy_counters_from_user() to consolidate counter
    copying, and use it from {arp,ip,ip6}tables.

18,22) Get rid of unnecessary explicit inlining in ctnetlink for dump
    functions.

19) Move nf_connlabel_match() to xt_connlabel.

20) Skip event notification if connlabel did not change.

21) Update of nf_connlabels_get() to make the upcoming nft connlabel
    support easier.

23) Remove spinlock to read protocol state field in conntrack.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-24 00:12:08 -04:00
Florian Westphal a163f2cb39 netfilter: conntrack: don't acquire lock during seq_printf
read access doesn't need any lock here.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-04-19 20:26:25 +02:00
Jozsef Kadlecsik 644c7e48cb netfilter: nf_conntrack_tcp: Fix stack out of bounds when parsing TCP options
Baozeng Ding reported a KASAN stack out of bounds issue - it uncovered that
the TCP option parsing routines in netfilter TCP connection tracking could
read one byte out of the buffer of the TCP options.  Therefore in the patch
we check that the available data length is large enough to parse both TCP
option code and size.

Reported-by: Baozeng Ding <sploving1@gmail.com>
Tested-by: Baozeng Ding <sploving1@gmail.com>
Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-04-07 18:42:37 +02:00
Eric W. Biederman a31f1adc09 netfilter: nf_conntrack: Add a struct net parameter to l4_pkt_to_tuple
As gre does not have the srckey in the packet gre_pkt_to_tuple
needs to perform a lookup in it's per network namespace tables.

Pass in the proper network namespace to all pkt_to_tuple
implementations to ensure gre (and any similar protocols) can get this
right.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-09-18 22:00:04 +02:00