Commit Graph

1525 Commits

Author SHA1 Message Date
Arnd Bergmann 96307a0a75 netfilter: ipt_CLUSTERIP: fix clusterip_net_exit build regression
The added check produces a build error when CONFIG_PROC_FS is
disabled:

net/ipv4/netfilter/ipt_CLUSTERIP.c: In function 'clusterip_net_exit':
net/ipv4/netfilter/ipt_CLUSTERIP.c:822:28: error: 'cn' undeclared (first use in this function)

This moves the variable declaration out of the #ifdef to make it
available to the WARN_ON_ONCE().

Fixes: 613d0776d3 ("netfilter: exit_net cleanup check added")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-12-07 23:19:58 +01:00
Vasily Averin 613d0776d3 netfilter: exit_net cleanup check added
Be sure that lists initialized in net_init hook was return to initial
state.

Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-11-20 12:03:41 +01:00
Colin Ian King 07dc8bc9a6 netfilter: remove redundant assignment to e
The assignment to variable e is redundant since the same assignment
occurs just a few lines later, hence it can be removed.  Cleans up
clang warning for arp_tables, ip_tables and ip6_tables:

warning: Value stored to 'e' is never read

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-11-20 12:03:41 +01:00
David S. Miller 2eb3ed33e5 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/IPVS updates for your net-next
tree, they are:

1) Speed up table replacement on busy systems with large tables
   (and many cores) in x_tables. Now xt_replace_table() synchronizes by
   itself by waiting until all cpus had an even seqcount and we use no
   use seqlock when fetching old counters, from Florian Westphal.

2) Add nf_l4proto_log_invalid() and nf_ct_l4proto_log_invalid() to speed
   up packet processing in the fast path when logging is not enabled, from
   Florian Westphal.

3) Precompute masked address from configuration plane in xt_connlimit,
   from Florian.

4) Don't use explicit size for set selection if performance set policy
   is selected.

5) Allow to get elements from an existing set in nf_tables.

6) Fix incorrect check in nft_hash_deactivate(), from Florian.

7) Cache netlink attribute size result in l4proto->nla_size, from
   Florian.

8) Handle NFPROTO_INET in nf_ct_netns_get() from conntrack core.

9) Use power efficient workqueue in conntrack garbage collector, from
   Vincent Guittot.

10) Remove unnecessary parameter, in conntrack l4proto functions, also
    from Florian.

11) Constify struct nf_conntrack_l3proto definitions, from Florian.

12) Remove all typedefs in nf_conntrack_h323 via coccinelle semantic
    patch, from Harsha Sharma.

13) Don't store address in the rbtree nodes in xt_connlimit, they are
    never used, from Florian.

14) Fix out of bound access in the conntrack h323 helper, patch from
    Eric Sesterhenn.

15) Print symbols for the address returned with %pS in IPVS, from
    Helge Deller.

16) Proc output should only display its own netns in IPVS, from
    KUWAZAWA Takuya.

17) Small clean up in size_entry_mwt(), from Colin Ian King.

18) Use test_and_clear_bit from nf_nat_proto_clean() instead of separated
    non-atomic test and then clear bit, from Florian Westphal.

19) Consolidate prefix length maps in ipset, from Aaron Conole.

20) Fix sparse warnings in ipset, from Jozsef Kadlecsik.

21) Simplify list_set_memsize(), from simran singhal.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-08 14:22:50 +09:00
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
David S. Miller 2a171788ba Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Files removed in 'net-next' had their license header updated
in 'net'.  We take the remove from 'net-next'.

Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-04 09:26:51 +09:00
Linus Torvalds 7ba3ebff9c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Pull networking fixes from David Miller:
 "Hopefully this is the last batch of networking fixes for 4.14

  Fingers crossed...

   1) Fix stmmac to use the proper sized OF property read, from Bhadram
      Varka.

   2) Fix use after free in net scheduler tc action code, from Cong
      Wang.

   3) Fix SKB control block mangling in tcp_make_synack().

   4) Use proper locking in fib_dump_info(), from Florian Westphal.

   5) Fix IPG encodings in systemport driver, from Florian Fainelli.

   6) Fix division by zero in NV TCP congestion control module, from
      Konstantin Khlebnikov.

   7) Fix use after free in nf_reject_ipv4, from Tejaswi Tanikella"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net:
  net: systemport: Correct IPG length settings
  tcp: do not mangle skb->cb[] in tcp_make_synack()
  fib: fib_dump_info can no longer use __in_dev_get_rtnl
  stmmac: use of_property_read_u32 instead of read_u8
  net_sched: hold netns refcnt for each action
  net_sched: acquire RTNL in tc_action_net_exit()
  net: vrf: correct FRA_L3MDEV encode type
  tcp_nv: fix division by zero in tcpnv_acked()
  netfilter: nf_reject_ipv4: Fix use-after-free in send_reset
  netfilter: nft_set_hash: disable fast_ops for 2-len keys
2017-11-03 09:09:21 -07:00
Greg Kroah-Hartman b24413180f License cleanup: add SPDX GPL-2.0 license identifier to files with no license
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02 11:10:55 +01:00
Tejaswi Tanikella 7400bb4b58 netfilter: nf_reject_ipv4: Fix use-after-free in send_reset
niph is not updated after pskb_expand_head changes the skb head. It
still points to the freed data, which is then used to update tot_len and
checksum. This could cause use-after-free poison crash.

Update niph, if ip_route_me_harder does not fail.

This only affects the interaction with REJECT targets and br_netfilter.

Signed-off-by: Tejaswi Tanikella <tejaswit@codeaurora.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-11-01 12:15:29 +01:00
Florian Westphal 28efb00465 netfilter: conntrack: make l3proto trackers const
previous patches removed all writes to them.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-10-24 18:01:50 +02:00
Florian Westphal d13e7b2e65 netfilter: x_tables: don't use seqlock when fetching old counters
after previous commit xt_replace_table will wait until all cpus
had even seqcount (i.e., no cpu is accessing old ruleset).

Add a 'old' counter retrival version that doesn't synchronize counters.
Its not needed, the old counters are not in use anymore at this point.

This speeds up table replacement on busy systems with large tables
(and many cores).

Cc: Dan Williams <dcbw@redhat.com>
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-10-24 18:01:50 +02:00
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 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
Gustavo A. R. Silva fcfd6dfab9 ipv4: mark expected switch fall-throughs
In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.

Notice that in some cases I placed the "fall through" comment
on its own line, which is what GCC is expecting to find.

Addresses-Coverity-ID: 115108
Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-18 14:10:29 +01:00
Lin Zhang 49f817d793 netfilter: SYNPROXY: skip non-tcp packet in {ipv4, ipv6}_synproxy_hook
In function {ipv4,ipv6}_synproxy_hook we expect a normal tcp packet, but
the real server maybe reply an icmp error packet related to the exist
tcp conntrack, so we will access wrong tcp data.

Fix it by checking for the protocol field and only process tcp traffic.

Signed-off-by: Lin Zhang <xiaolou4617@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-10-09 13:08:39 +02:00
Florian Westphal a5d7a71456 netfilter: xtables: add scheduling opportunity in get_counters
There are reports about spurious softlockups during iptables-restore, a
backtrace i saw points at get_counters -- it uses a sequence lock and also
has unbounded restart loop.

Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-09-08 18:55:27 +02:00
Varsha Rao 9efdb14f76 net: Remove CONFIG_NETFILTER_DEBUG and _ASSERT() macros.
This patch removes CONFIG_NETFILTER_DEBUG and _ASSERT() macros as they
are no longer required. Replace _ASSERT() macros with WARN_ON().

Signed-off-by: Varsha Rao <rvarsha016@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-09-04 13:25:20 +02:00
Varsha Rao 44d6e2f273 net: Replace NF_CT_ASSERT() with WARN_ON().
This patch removes NF_CT_ASSERT() and instead uses WARN_ON().

Signed-off-by: Varsha Rao <rvarsha016@gmail.com>
2017-09-04 13:25:19 +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
David S. Miller b63f6044d8 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. Basically, updates to the conntrack core, enhancements for
nf_tables, conversion of netfilter hooks from linked list to array to
improve memory locality and asorted improvements for the Netfilter
codebase. More specifically, they are:

1) Add expection to hashes after timer initialization to prevent
   access from another CPU that walks on the hashes and calls
   del_timer(), from Florian Westphal.

2) Don't update nf_tables chain counters from hot path, this is only
   used by the x_tables compatibility layer.

3) Get rid of nested rcu_read_lock() calls from netfilter hook path.
   Hooks are always guaranteed to run from rcu read side, so remove
   nested rcu_read_lock() where possible. Patch from Taehee Yoo.

4) nf_tables new ruleset generation notifications include PID and name
   of the process that has updated the ruleset, from Phil Sutter.

5) Use skb_header_pointer() from nft_fib, so we can reuse this code from
   the nf_family netdev family. Patch from Pablo M. Bermudo.

6) Add support for nft_fib in nf_tables netdev family, also from Pablo.

7) Use deferrable workqueue for conntrack garbage collection, to reduce
   power consumption, from Patch from Subash Abhinov Kasiviswanathan.

8) Add nf_ct_expect_iterate_net() helper and use it. From Florian
   Westphal.

9) Call nf_ct_unconfirmed_destroy only from cttimeout, from Florian.

10) Drop references on conntrack removal path when skbuffs has escaped via
    nfqueue, from Florian.

11) Don't queue packets to nfqueue with dying conntrack, from Florian.

12) Constify nf_hook_ops structure, from Florian.

13) Remove neededlessly branch in nf_tables trace code, from Phil Sutter.

14) Add nla_strdup(), from Phil Sutter.

15) Rise nf_tables objects name size up to 255 chars, people want to use
    DNS names, so increase this according to what RFC 1035 specifies.
    Patch series from Phil Sutter.

16) Kill nf_conntrack_default_on, it's broken. Default on conntrack hook
    registration on demand, suggested by Eric Dumazet, patch from Florian.

17) Remove unused variables in compat_copy_entry_from_user both in
    ip_tables and arp_tables code. Patch from Taehee Yoo.

18) Constify struct nf_conntrack_l4proto, from Julia Lawall.

19) Constify nf_loginfo structure, also from Julia.

20) Use a single rb root in connlimit, from Taehee Yoo.

21) Remove unused netfilter_queue_init() prototype, from Taehee Yoo.

22) Use audit_log() instead of open-coding it, from Geliang Tang.

23) Allow to mangle tcp options via nft_exthdr, from Florian.

24) Allow to fetch TCP MSS from nft_rt, from Florian. This includes
    a fix for a miscalculation of the minimal length.

25) Simplify branch logic in h323 helper, from Nick Desaulniers.

26) Calculate netlink attribute size for conntrack tuple at compile
    time, from Florian.

27) Remove protocol name field from nf_conntrack_{l3,l4}proto structure.
    From Florian.

28) Remove holes in nf_conntrack_l4proto structure, so it becomes
    smaller. From Florian.

29) Get rid of print_tuple() indirection for /proc conntrack listing.
    Place all the code in net/netfilter/nf_conntrack_standalone.c.
    Patch from Florian.

30) Do not built in print_conntrack() if CONFIG_NF_CONNTRACK_PROCFS is
    off. From Florian.

31) Constify most nf_conntrack_{l3,l4}proto helper functions, from
    Florian.

32) Fix broken indentation in ebtables extensions, from Colin Ian King.

33) Fix several harmless sparse warning, from Florian.

34) Convert netfilter hook infrastructure to use array for better memory
    locality, joint work done by Florian and Aaron Conole. Moreover, add
    some instrumentation to debug this.

35) Batch nf_unregister_net_hooks() calls, to call synchronize_net once
    per batch, from Florian.

36) Get rid of noisy logging in ICMPv6 conntrack helper, from Florian.

37) Get rid of obsolete NFDEBUG() instrumentation, from Varsha Rao.

38) Remove unused code in the generic protocol tracker, from Davide
    Caratti.

I think I will have material for a second Netfilter batch in my queue if
time allow to make it fit in this merge window.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-03 17:08:42 -07:00
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
Florian Westphal a3134d537f netfilter: conntrack: remove protocol name from l3proto 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
Florian Westphal 0d03510038 netfilter: conntrack: compute l3proto nla size at compile time
avoids a pointer and allows struct to be const later on.

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
Nick Desaulniers eee6ebbac1 netfilter: nf_nat_h323: fix logical-not-parentheses warning
Clang produces the following warning:

net/ipv4/netfilter/nf_nat_h323.c:553:6: error:
logical not is only applied to the left hand side of this comparison
  [-Werror,-Wlogical-not-parentheses]
if (!set_h225_addr(skb, protoff, data, dataoff, taddr,
    ^
add parentheses after the '!' to evaluate the comparison first
add parentheses around left hand side expression to silence this warning

There's not necessarily a bug here, but it's cleaner to return early,
ex:

if (x)
  return
...

rather than:

if (x == 0)
  ...
else
  return

Also added a return code check that seemed to be missing in one
instance.

Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-08-24 18:48:05 +02:00
Julia Lawall 549d2d41c1 netfilter: constify nf_loginfo structures
The nf_loginfo structures are only passed as the seventh argument to
nf_log_trace, which is declared as const or stored in a local const
variable.  Thus the nf_loginfo structures themselves can be const.

Done with the help of Coccinelle.

// <smpl>
@r disable optional_qualifier@
identifier i;
position p;
@@
static struct nf_loginfo i@p = { ... };

@ok1@
identifier r.i;
expression list[6] es;
position p;
@@
 nf_log_trace(es,&i@p,...)

@ok2@
identifier r.i;
const struct nf_loginfo *e;
position p;
@@
 e = &i@p

@bad@
position p != {r.p,ok1.p,ok2.p};
identifier r.i;
struct nf_loginfo e;
@@
e@i@p

@depends on !bad disable optional_qualifier@
identifier r.i;
@@
static
+const
 struct nf_loginfo i = { ... };
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-08-02 14:25:59 +02:00
Taehee Yoo 5b9ccdcb98 netfilter: xtables: Remove unused variable in compat_copy_entry_from_user()
The target variable is not used in the compat_copy_entry_from_user().
So It can be removed.

Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-08-02 14:25:50 +02:00
Florian Westphal 4d3a57f23d netfilter: conntrack: do not enable connection tracking unless needed
Discussion during NFWS 2017 in Faro has shown that the current
conntrack behaviour is unreasonable.

Even if conntrack module is loaded on behalf of a single net namespace,
its turned on for all namespaces, which is expensive.  Commit
481fa37347 ("netfilter: conntrack: add nf_conntrack_default_on sysctl")
attempted to provide an alternative to the 'default on' behaviour by
adding a sysctl to change it.

However, as Eric points out, the sysctl only becomes available
once the module is loaded, and then its too late.

So we either have to move the sysctl to the core, or, alternatively,
change conntrack to become active only once the rule set requires this.

This does the latter, conntrack is only enabled when a rule needs it.

Reported-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-07-31 20:42:00 +02:00
Taehee Yoo 9beceb54fa netfilter: x_tables: Fix use-after-free in ipt_do_table.
If verdict is NF_STOLEN in the SYNPROXY target,
the skb is consumed.
However, ipt_do_table() always tries to get ip header from the skb.
So that, KASAN triggers the use-after-free message.

We can reproduce this message using below command.
  # iptables -I INPUT -p tcp -j SYNPROXY --mss 1460

[ 193.542265] BUG: KASAN: use-after-free in ipt_do_table+0x1405/0x1c10
[ ... ]
[ 193.578603] Call Trace:
[ 193.581590] <IRQ>
[ 193.584107] dump_stack+0x68/0xa0
[ 193.588168] print_address_description+0x78/0x290
[ 193.593828] ? ipt_do_table+0x1405/0x1c10
[ 193.598690] kasan_report+0x230/0x340
[ 193.603194] __asan_report_load2_noabort+0x19/0x20
[ 193.608950] ipt_do_table+0x1405/0x1c10
[ 193.613591] ? rcu_read_lock_held+0xae/0xd0
[ 193.618631] ? ip_route_input_rcu+0x27d7/0x4270
[ 193.624348] ? ipt_do_table+0xb68/0x1c10
[ 193.629124] ? do_add_counters+0x620/0x620
[ 193.634234] ? iptable_filter_net_init+0x60/0x60
[ ... ]

After this patch, only when verdict is XT_CONTINUE,
ipt_do_table() tries to get ip header.
Also arpt_do_table() is modified because it has same bug.

Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-07-31 20:24:09 +02:00
Florian Westphal 591bb2789b netfilter: nf_hook_ops structs can be const
We no longer place these on a list so they can be const.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-07-31 19:10:44 +02:00
Pablo M. Bermudo Garay f347ec852c netfilter: nf_tables: fib: use skb_header_pointer
This is a preparatory patch for adding fib support to the netdev family.

The netdev family receives the packets from ingress hook. At this point
we have no guarantee that the ip header is linear. So this patch
replaces ip_hdr with skb_header_pointer in order to address that
possible situation.

Signed-off-by: Pablo M. Bermudo Garay <pablombg@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-07-31 19:01:39 +02:00
Sabrina Dubroca 3840538ad3 netfilter: ipt_CLUSTERIP: fix use-after-free of proc entry
When we delete a netns with a CLUSTERIP rule, clusterip_net_exit() is
called first, removing /proc/net/ipt_CLUSTERIP.
Then clusterip_config_entry_put() is called from clusterip_tg_destroy(),
and tries to remove its entry under /proc/net/ipt_CLUSTERIP/.

Fix this by checking that the parent directory of the entry to remove
hasn't already been deleted.

The following triggers a KASAN splat (stealing the reproducer from
202f59afd4, thanks to Jianlin Shi and Xin Long):

    ip netns add test
    ip link add veth0_in type veth peer name veth0_out
    ip link set veth0_in netns test
    ip netns exec test ip link set lo up
    ip netns exec test ip link set veth0_in up
    ip netns exec test iptables -I INPUT -d 1.2.3.4 -i veth0_in -j     \
        CLUSTERIP --new --clustermac 89:d4:47:eb:9a:fa --total-nodes 3 \
        --local-node 1 --hashmode sourceip-sourceport
    ip netns del test

Fixes: ce4ff76c15 ("netfilter: ipt_CLUSTERIP: make proc directory per net namespace")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Reviewed-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-07-19 11:53:25 +02:00
Florian Westphal 974292defe netfilter: nf_tables: only allow in/output for arp packets
arp packets cannot be forwarded.

They can be bridged, but then they can be filtered using
either ebtables or nftables bridge family.

The bridge netfilter exposes a "call-arptables" switch which
pushes packets into arptables, but lets not expose this for nftables, so better
close this asap.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-07-17 17:02:44 +02:00
David S. Miller 52a623bd61 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. This batch contains connection tracking updates for the cleanup
iteration path, patches from Florian Westphal:

X) Skip unconfirmed conntracks in nf_ct_iterate_cleanup_net(), just set
   dying bit to let the CPU release them.

X) Add nf_ct_iterate_destroy() to be used on module removal, to kill
   conntrack from all namespace.

X) Restart iteration on hashtable resizing, since both may occur at
   the same time.

X) Use the new nf_ct_iterate_destroy() to remove conntrack with NAT
   mapping on module removal.

X) Use nf_ct_iterate_destroy() to remove conntrack entries helper
   module removal, from Liping Zhang.

X) Use nf_ct_iterate_cleanup_net() to remove the timeout extension
   if user requests this, also from Liping.

X) Add net_ns_barrier() and use it from FTP helper, so make sure
   no concurrent namespace removal happens at the same time while
   the helper module is being removed.

X) Use NFPROTO_MAX in layer 3 conntrack protocol array, to reduce
   module size. Same thing in nf_tables.

Updates for the nf_tables infrastructure:

X) Prepare usage of the extended ACK reporting infrastructure for
   nf_tables.

X) Remove unnecessary forward declaration in nf_tables hash set.

X) Skip set size estimation if number of element is not specified.

X) Changes to accomodate a (faster) unresizable hash set implementation,
   for anonymous sets and dynamic size fixed sets with no timeouts.

X) Faster lookup function for unresizable hash table for 2 and 4
   bytes key.

And, finally, a bunch of asorted small updates and cleanups:

X) Do not hold reference to netdev from ipt_CLUSTER, instead subscribe
   to device events and look up for index from the packet path, this
   is fixing an issue that is present since the very beginning, patch
   from Xin Long.

X) Use nf_register_net_hook() in ipt_CLUSTER, from Florian Westphal.

X) Use ebt_invalid_target() whenever possible in the ebtables tree,
   from Gao Feng.

X) Calm down compilation warning in nf_dup infrastructure, patch from
   stephen hemminger.

X) Statify functions in nftables rt expression, also from stephen.

X) Update Makefile to use canonical method to specify nf_tables-objs.
   From Jike Song.

X) Use nf_conntrack_helpers_register() in amanda and H323.

X) Space cleanup for ctnetlink, from linzhang.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-30 06:27:09 -07:00
Xin Long 202f59afd4 netfilter: ipt_CLUSTERIP: do not hold dev
It's a terrible thing to hold dev in iptables target. When the dev is
being removed, unregister_netdevice has to wait for the dev to become
free. dmesg will keep logging the err:

  kernel:unregister_netdevice: waiting for veth0_in to become free. \
  Usage count = 1

until iptables rules with this target are removed manually.

The worse thing is when deleting a netns, a virtual nic will be deleted
instead of reset to init_net in default_device_ops exit/exit_batch. As
it is earlier than to flush the iptables rules in iptable_filter_net_ops
exit, unregister_netdevice will block to wait for the nic to become free.

As unregister_netdevice is actually waiting for iptables rules flushing
while iptables rules have to be flushed after unregister_netdevice. This
'dead lock' will cause unregister_netdevice to block there forever. As
the netns is not available to operate at that moment, iptables rules can
not even be flushed manually either.

The reproducer can be:

  # ip netns add test
  # ip link add veth0_in type veth peer name veth0_out
  # ip link set veth0_in netns test
  # ip netns exec test ip link set lo up
  # ip netns exec test ip link set veth0_in up
  # ip netns exec test iptables -I INPUT -d 1.2.3.4 -i veth0_in -j \
    CLUSTERIP --new --clustermac 89:d4:47:eb:9a:fa --total-nodes 3 \
    --local-node 1 --hashmode sourceip-sourceport
  # ip netns del test

This issue can be triggered by all virtual nics with ipt_CLUSTERIP.

This patch is to fix it by not holding dev in ipt_CLUSTERIP, but saving
the dev->ifindex instead of the dev.

As Pablo Neira Ayuso's suggestion, it will refresh c->ifindex and dev's
mc by registering a netdevice notifier, just as what xt_TEE does. So it
removes the old codes updating dev's mc, and also no need to initialize
c->ifindex with dev->ifindex.

But as one config can be shared by more than one targets, and the netdev
notifier is per config, not per target. It couldn't get e->ip.iniface
in the notifier handler. So e->ip.iniface has to be saved into config.

Note that for backwards compatibility, this patch doesn't remove the
codes checking if the dev exists before creating a config.

v1->v2:
  - As Pablo Neira Ayuso's suggestion, register a netdevice notifier to
    manage c->ifindex and dev's mc.

Reported-by: Jianlin Shi <jishi@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-06-19 19:06:20 +02:00
Johannes Berg 4df864c1d9 networking: make skb_put & friends return void pointers
It seems like a historic accident that these return unsigned char *,
and in many places that means casts are required, more often than not.

Make these functions (skb_put, __skb_put and pskb_put) return void *
and remove all the casts across the tree, adding a (u8 *) cast only
where the unsigned char pointer was used directly, all done with the
following spatch:

    @@
    expression SKB, LEN;
    typedef u8;
    identifier fn = { skb_put, __skb_put };
    @@
    - *(fn(SKB, LEN))
    + *(u8 *)fn(SKB, LEN)

    @@
    expression E, SKB, LEN;
    identifier fn = { skb_put, __skb_put };
    type T;
    @@
    - E = ((T *)(fn(SKB, LEN)))
    + E = fn(SKB, LEN)

which actually doesn't cover pskb_put since there are only three
users overall.

A handful of stragglers were converted manually, notably a macro in
drivers/isdn/i4l/isdn_bsdcomp.c and, oddly enough, one of the many
instances in net/bluetooth/hci_sock.c. In the former file, I also
had to fix one whitespace problem spatch introduced.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-16 11:48:39 -04:00
Johannes Berg b080db5853 networking: convert many more places to skb_put_zero()
There were many places that my previous spatch didn't find,
as pointed out by yuan linyu in various patches.

The following spatch found many more and also removes the
now unnecessary casts:

    @@
    identifier p, p2;
    expression len;
    expression skb;
    type t, t2;
    @@
    (
    -p = skb_put(skb, len);
    +p = skb_put_zero(skb, len);
    |
    -p = (t)skb_put(skb, len);
    +p = skb_put_zero(skb, len);
    )
    ... when != p
    (
    p2 = (t2)p;
    -memset(p2, 0, len);
    |
    -memset(p, 0, len);
    )

    @@
    type t, t2;
    identifier p, p2;
    expression skb;
    @@
    t *p;
    ...
    (
    -p = skb_put(skb, sizeof(t));
    +p = skb_put_zero(skb, sizeof(t));
    |
    -p = (t *)skb_put(skb, sizeof(t));
    +p = skb_put_zero(skb, sizeof(t));
    )
    ... when != p
    (
    p2 = (t2)p;
    -memset(p2, 0, sizeof(*p));
    |
    -memset(p, 0, sizeof(*p));
    )

    @@
    expression skb, len;
    @@
    -memset(skb_put(skb, len), 0, len);
    +skb_put_zero(skb, len);

Apply it to the tree (with one manual fixup to keep the
comment in vxlan.c, which spatch removed.)

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-16 11:48:35 -04:00
Florian Westphal 9fd6452d67 netfilter: conntrack: rename nf_ct_iterate_cleanup
There are several places where we needlesly call nf_ct_iterate_cleanup,
we should instead iterate the full table at module unload time.

This is a leftover from back when the conntrack table got duplicated
per net namespace.

So rename nf_ct_iterate_cleanup to nf_ct_iterate_cleanup_net.
A later patch will then add a non-net variant.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-05-29 12:46:08 +02:00
Florian Westphal 03eb7d494a netfilter: ipt_CLUSTERIP: switch to nf_register_net_hook
one of the last remaining users of the old api, hopefully followup commit
can remove it soon.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-05-29 11:32:35 +02:00
Davide Caratti 219f1d7987 sk_buff: remove support for csum_bad in sk_buff
This bit was introduced with commit 5a21232983 ("net: Support for
csum_bad in skbuff") to reduce the stack workload when processing RX
packets carrying a wrong Internet Checksum. Up to now, only one driver and
GRO core are setting it.

Suggested-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-19 19:21:29 -04:00
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
Florian Westphal 0e72f55f35 netfilter: snmp: avoid stack size warning
net/ipv4/netfilter/nf_nat_snmp_basic.c:1158:1: warning: the frame size
of 1160 bytes is larger than 1024 bytes

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-05-01 11:43:58 +02:00
Florian Westphal 9a08ecfe74 netfilter: don't attach a nat extension by default
nowadays the NAT extension only stores the interface index
(used to purge connections that got masqueraded when interface goes down)
and pptp nat information.

Previous patches moved nf_ct_nat_ext_add to those places that need it.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-04-26 09:30:22 +02:00
Florian Westphal 2fe7c321ab netfilter: pptp: attach nat extension when needed
make sure nat extension gets added if the master conntrack is subject to
NAT.  This will be required once the nat core stops adding it by default.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-04-26 09:30:22 +02:00
Florian Westphal ff459018d7 netfilter: masquerade: attach nat extension if not present
Currently the nat extension is always attached as soon as nat module is
loaded.  However, most NAT uses do not need the nat extension anymore.

Prepare to remove the add-nat-by-default by making those places that need
it attach it if its not present yet.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-04-26 09:30:22 +02:00
Gao Feng 495dcb56d0 netfilter: SYNPROXY: Return NF_STOLEN instead of NF_DROP during handshaking
Current SYNPROXY codes return NF_DROP during normal TCP handshaking,
it is not friendly to caller. Because the nf_hook_slow would treat
the NF_DROP as an error, and return -EPERM.
As a result, it may cause the top caller think it meets one error.

For example, the following codes are from cfv_rx_poll()
	err = netif_receive_skb(skb);
	if (unlikely(err)) {
		++cfv->ndev->stats.rx_dropped;
	} else {
		++cfv->ndev->stats.rx_packets;
		cfv->ndev->stats.rx_bytes += skb_len;
	}
When SYNPROXY returns NF_DROP, then netif_receive_skb returns -EPERM.
As a result, the cfv driver would treat it as an error, and increase
the rx_dropped counter.

So use NF_STOLEN instead of NF_DROP now because there is no error
happened indeed, and free the skb directly.

Signed-off-by: Gao Feng <fgao@ikuai8.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-04-26 09:30:22 +02:00
Florian Westphal 1fefe14725 netfilter: synproxy: only register hooks when needed
Defer registration of the synproxy hooks until the first SYNPROXY rule is
added.  Also means we only register hooks in namespaces that need it.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-04-26 09:30:21 +02:00
David S. Miller 6b6cbc1471 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts were simply overlapping changes.  In the net/ipv4/route.c
case the code had simply moved around a little bit and the same fix
was made in both 'net' and 'net-next'.

In the net/sched/sch_generic.c case a fix in 'net' happened at
the same time that a new argument was added to qdisc_hash_add().

Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-15 21:16:30 -04:00
Florian Westphal ab8bc7ed86 netfilter: remove nf_ct_is_untracked
This function is now obsolete and always returns false.
This change has no effect on generated code.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-04-15 11:51:33 +02:00
Florian Westphal cc41c84b7e netfilter: kill the fake untracked conntrack objects
resurrect an old patch from Pablo Neira to remove the untracked objects.

Currently, there are four possible states of an skb wrt. conntrack.

1. No conntrack attached, ct is NULL.
2. Normal (kmem cache allocated) ct attached.
3. a template (kmalloc'd), not in any hash tables at any point in time
4. the 'untracked' conntrack, a percpu nf_conn object, tagged via
   IPS_UNTRACKED_BIT in ct->status.

Untracked is supposed to be identical to case 1.  It exists only
so users can check

-m conntrack --ctstate UNTRACKED vs.
-m conntrack --ctstate INVALID

e.g. attempts to set connmark on INVALID or UNTRACKED conntracks is
supposed to be a no-op.

Thus currently we need to check
 ct == NULL || nf_ct_is_untracked(ct)

in a lot of places in order to avoid altering untracked objects.

The other consequence of the percpu untracked object is that all
-j NOTRACK (and, later, kfree_skb of such skbs) result in an atomic op
(inc/dec the untracked conntracks refcount).

This adds a new kernel-private ctinfo state, IP_CT_UNTRACKED, to
make the distinction instead.

The (few) places that care about packet invalid (ct is NULL) vs.
packet untracked now need to test ct == NULL vs. ctinfo == IP_CT_UNTRACKED,
but all other places can omit the nf_ct_is_untracked() check.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-04-15 11:47:57 +02:00