Commit Graph

153 Commits

Author SHA1 Message Date
Toke Høiland-Jørgensen b60a60405f netfilter: Add nf_ct_get_tuple_skb global lookup function
This adds a global netfilter function to extract a conntrack tuple from an
skb. The function uses a new function added to nf_ct_hook, which will try
to get the tuple from skb->_nfct, and do a full lookup if that fails. This
makes it possible to use the lookup function before the skb has passed
through the conntrack init hooks (e.g., in an ingress qdisc). The tuple is
copied to the caller to avoid issues with reference counting.

The function returns false if conntrack is not loaded, allowing it to be
used without incurring a module dependency on conntrack. This is used by
the NAT mode in sch_cake.

Cc: netfilter-devel@vger.kernel.org
Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-10 20:06:34 -07:00
Edward Cree 9f17dbf04d netfilter: fix use-after-free in NF_HOOK_LIST
nf_hook() can free the skb, so we need to remove it from the list before
 calling, and add passed skbs to a sublist afterwards.

Fixes: 17266ee939 ("net: ipv4: listified version of ip_rcv")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-09 14:55:53 -07:00
Edward Cree 17266ee939 net: ipv4: listified version of ip_rcv
Also involved adding a way to run a netfilter hook over a list of packets.
 Rather than attempting to make netfilter know about lists (which would be
 a major project in itself) we just let it call the regular okfn (in this
 case ip_rcv_finish()) for any packets it steals, and have it give us back
 a list of packets it's synchronously accepted (which normally NF_HOOK
 would automatically call okfn() on, but we want to be able to potentially
 pass the list to a listified version of okfn().)
The netfilter hooks themselves are indirect calls that still happen per-
 packet (see nf_hook_entry_hookfn()), but again, changing that can be left
 for future work.

There is potential for out-of-order receives if the netfilter hook ends up
 synchronously stealing packets, as they will be processed before any
 accepts earlier in the list.  However, it was already possible for an
 asynchronous accept to cause out-of-order receives, so presumably this is
 considered OK.

Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-04 14:06:20 +09:00
Prashant Bhole 155fb5c5fa netfilter: fix null-ptr-deref in nf_nat_decode_session
Add null check for nat_hook in nf_nat_decode_session()

[  195.648098] UBSAN: Undefined behaviour in ./include/linux/netfilter.h:348:14
[  195.651366] BUG: KASAN: null-ptr-deref in __xfrm_policy_check+0x208/0x1d70
[  195.653888] member access within null pointer of type 'struct nf_nat_hook'
[  195.653896] CPU: 3 PID: 0 Comm: swapper/3 Not tainted 4.17.0-rc6+ #5
[  195.656320] Read of size 8 at addr 0000000000000008 by task ping/2469
[  195.658715] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
[  195.658721] Call Trace:
[  195.661087]
[  195.669341]  <IRQ>
[  195.670574]  dump_stack+0xc6/0x150
[  195.672156]  ? dump_stack_print_info.cold.0+0x1b/0x1b
[  195.674121]  ? ubsan_prologue+0x31/0x92
[  195.676546]  ubsan_epilogue+0x9/0x49
[  195.678159]  handle_null_ptr_deref+0x11a/0x130
[  195.679800]  ? sprint_OID+0x1a0/0x1a0
[  195.681322]  __ubsan_handle_type_mismatch_v1+0xd5/0x11d
[  195.683146]  ? ubsan_prologue+0x92/0x92
[  195.684642]  __xfrm_policy_check+0x18ef/0x1d70
[  195.686294]  ? rt_cache_valid+0x118/0x180
[  195.687804]  ? __xfrm_route_forward+0x410/0x410
[  195.689463]  ? fib_multipath_hash+0x700/0x700
[  195.691109]  ? kvm_sched_clock_read+0x23/0x40
[  195.692805]  ? pvclock_clocksource_read+0xf6/0x280
[  195.694409]  ? graph_lock+0xa0/0xa0
[  195.695824]  ? pvclock_clocksource_read+0xf6/0x280
[  195.697508]  ? pvclock_read_flags+0x80/0x80
[  195.698981]  ? kvm_sched_clock_read+0x23/0x40
[  195.700347]  ? sched_clock+0x5/0x10
[  195.701525]  ? sched_clock_cpu+0x18/0x1a0
[  195.702846]  tcp_v4_rcv+0x1d32/0x1de0
[  195.704115]  ? lock_repin_lock+0x70/0x270
[  195.707072]  ? pvclock_read_flags+0x80/0x80
[  195.709302]  ? tcp_v4_early_demux+0x4b0/0x4b0
[  195.711833]  ? lock_acquire+0x195/0x380
[  195.714222]  ? ip_local_deliver_finish+0xfc/0x770
[  195.716967]  ? raw_rcv+0x2b0/0x2b0
[  195.718856]  ? lock_release+0xa00/0xa00
[  195.720938]  ip_local_deliver_finish+0x1b9/0x770
[...]

Fixes: 2c205dd398 ("netfilter: add struct nf_nat_hook and use it")
Signed-off-by: Prashant Bhole <bhole_prashant_q7@lab.ntt.co.jp>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-06-12 19:12:43 +02:00
Pablo Neira Ayuso 368982cd7d netfilter: nfnetlink_queue: resolve clash for unconfirmed conntracks
In nfqueue, two consecutive skbuffs may race to create the conntrack
entry. Hence, the one that loses the race gets dropped due to clash in
the insertion into the hashes from the nf_conntrack_confirm() path.

This patch adds a new nf_conntrack_update() function which searches for
possible clashes and resolve them. NAT mangling for the packet losing
race is corrected by using the conntrack information that won race.

In order to avoid direct module dependencies with conntrack and NAT, the
nf_ct_hook and nf_nat_hook structures are used for this purpose.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-05-23 09:26:08 +02:00
Pablo Neira Ayuso 2c205dd398 netfilter: add struct nf_nat_hook and use it
Move decode_session() and parse_nat_setup_hook() indirections to struct
nf_nat_hook structure.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-05-23 09:26:07 +02:00
Pablo Neira Ayuso 1f4b24397d netfilter: add struct nf_ct_hook and use it
Move the nf_ct_destroy indirection to the struct nf_ct_hook.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-05-23 09:26:06 +02:00
Florian Westphal a37061a678 netfilter: lift one-nat-hook-only restriction
This reverts commit f92b40a8b2
("netfilter: core: only allow one nat hook per hook point"), this
limitation is no longer needed.  The nat core now invokes these
functions and makes sure that hook evaluation stops after a mapping is
created and a null binding is created otherwise.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-05-23 09:14:06 +02:00
Pablo Neira Ayuso b3a61254d8 netfilter: remove struct nf_afinfo and its helper functions
This abstraction has no clients anymore, remove it.

This is what remains from previous authors, so correct copyright
statement after recent modifications and code removal.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-01-08 18:11:02 +01:00
Pablo Neira Ayuso 464356234f netfilter: remove route_key_size field in struct nf_afinfo
This is only needed by nf_queue, place this code where it belongs.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-01-08 18:11:01 +01:00
Pablo Neira Ayuso ce388f452f netfilter: move reroute indirection to struct nf_ipv6_ops
We cannot make a direct call to nf_ip6_reroute() because that would result
in autoloading the 'ipv6' module because of symbol dependencies.
Therefore, define reroute indirection in nf_ipv6_ops where this really
belongs to.

For IPv4, we can indeed make a direct function call, which is faster,
given IPv4 is built-in in the networking code by default. Still,
CONFIG_INET=n and CONFIG_NETFILTER=y is possible, so define empty inline
stub for IPv4 in such case.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-01-08 18:10:53 +01:00
Pablo Neira Ayuso 3f87c08c61 netfilter: move route indirection to struct nf_ipv6_ops
We cannot make a direct call to nf_ip6_route() because that would result
in autoloading the 'ipv6' module because of symbol dependencies.
Therefore, define route indirection in nf_ipv6_ops where this really
belongs to.

For IPv4, we can indeed make a direct function call, which is faster,
given IPv4 is built-in in the networking code by default. Still,
CONFIG_INET=n and CONFIG_NETFILTER=y is possible, so define empty inline
stub for IPv4 in such case.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-01-08 18:01:26 +01:00
Pablo Neira Ayuso 7db9a51e0f netfilter: remove saveroute indirection in struct nf_afinfo
This is only used by nf_queue.c and this function comes with no symbol
dependencies with IPv6, it just refers to structure layouts. Therefore,
we can replace it by a direct function call from where it belongs.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-01-08 18:01:25 +01:00
Pablo Neira Ayuso f7dcbe2f36 netfilter: move checksum_partial indirection to struct nf_ipv6_ops
We cannot make a direct call to nf_ip6_checksum_partial() because that
would result in autoloading the 'ipv6' module because of symbol
dependencies.  Therefore, define checksum_partial indirection in
nf_ipv6_ops where this really belongs to.

For IPv4, we can indeed make a direct function call, which is faster,
given IPv4 is built-in in the networking code by default. Still,
CONFIG_INET=n and CONFIG_NETFILTER=y is possible, so define empty inline
stub for IPv4 in such case.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-01-08 18:01:24 +01:00
Pablo Neira Ayuso ef71fe27ec netfilter: move checksum indirection to struct nf_ipv6_ops
We cannot make a direct call to nf_ip6_checksum() because that would
result in autoloading the 'ipv6' module because of symbol dependencies.
Therefore, define checksum indirection in nf_ipv6_ops where this really
belongs to.

For IPv4, we can indeed make a direct function call, which is faster,
given IPv4 is built-in in the networking code by default. Still,
CONFIG_INET=n and CONFIG_NETFILTER=y is possible, so define empty inline
stub for IPv4 in such case.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-01-08 18:01:23 +01:00
Florian Westphal f92b40a8b2 netfilter: core: only allow one nat hook per hook point
The netfilter NAT core cannot deal with more than one NAT hook per hook
location (prerouting, input ...), because the NAT hooks install a NAT null
binding in case the iptables nat table (iptable_nat hooks) or the
corresponding nftables chain (nft nat hooks) doesn't specify a nat
transformation.

Null bindings are needed to detect port collsisions between NAT-ed and
non-NAT-ed connections.

This causes nftables NAT rules to not work when iptable_nat module is
loaded, and vice versa because nat binding has already been attached
when the second nat hook is consulted.

The netfilter core is not really the correct location to handle this
(hooks are just hooks, the core has no notion of what kinds of side
 effects a hook implements), but its the only place where we can check
for conflicts between both iptables hooks and nftables hooks without
adding dependencies.

So add nat annotation to hook_ops to describe those hooks that will
add NAT bindings and then make core reject if such a hook already exists.
The annotation fills a padding hole, in case further restrictions appar
we might change this to a 'u8 type' instead of bool.

iptables error if nft nat hook active:
iptables -t nat -A POSTROUTING -j MASQUERADE
iptables v1.4.21: can't initialize iptables table `nat': File exists
Perhaps iptables or your kernel needs to be upgraded.

nftables error if iptables nat table present:
nft -f /etc/nftables/ipv4-nat
/usr/etc/nftables/ipv4-nat:3:1-2: Error: Could not process rule: File exists
table nat {
^^

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-01-08 18:01:13 +01:00
Florian Westphal 2a95183a5e netfilter: don't allocate space for arp/bridge hooks unless needed
no need to define hook points if the family isn't supported.
Because we need these hooks for either nftables, arp/ebtables
or the 'call-iptables' hack we have in the bridge layer add two
new dependencies, NETFILTER_FAMILY_{ARP,BRIDGE}, and have the
users select them.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-01-08 18:01:11 +01:00
Florian Westphal bb4badf3a3 netfilter: don't allocate space for decnet hooks unless needed
no need to define hook points if the family isn't supported.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-01-08 18:01:10 +01:00
Florian Westphal b0f38338ae netfilter: reduce size of hook entry point locations
struct net contains:

struct nf_hook_entries __rcu *hooks[NFPROTO_NUMPROTO][NF_MAX_HOOKS];

which store the hook entry point locations for the various protocol
families and the hooks.

Using array results in compact c code when doing accesses, i.e.
  x = rcu_dereference(net->nf.hooks[pf][hook]);

but its also wasting a lot of memory, as most families are
not used.

So split the array into those families that are used, which
are only 5 (instead of 13).  In most cases, the 'pf' argument is
constant, i.e. gcc removes switch statement.

struct net before:
 /* size: 5184, cachelines: 81, members: 46 */
after:
 /* size: 4672, cachelines: 73, members: 46 */

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-01-08 18:01:08 +01:00
Florian Westphal 8c873e2199 netfilter: core: free hooks with call_rcu
Giuseppe Scrivano says:
  "SELinux, if enabled, registers for each new network namespace 6
    netfilter hooks."

Cost for this is high.  With synchronize_net() removed:
   "The net benefit on an SMP machine with two cores is that creating a
   new network namespace takes -40% of the original time."

This patch replaces synchronize_net+kvfree with call_rcu().
We store rcu_head at the tail of a structure that has no fixed layout,
i.e. we cannot use offsetof() to compute the start of the original
allocation.  Thus store this information right after the rcu head.

We could simplify this by just placing the rcu_head at the start
of struct nf_hook_entries.  However, this structure is used in
packet processing hotpath, so only place what is needed for that
at the beginning of the struct.

Reported-by: Giuseppe Scrivano <gscrivan@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-01-08 18:01:07 +01:00
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
Aaron Conole 960632ece6 netfilter: convert hook list to an array
This converts the storage and layout of netfilter hook entries from a
linked list to an array.  After this commit, hook entries will be
stored adjacent in memory.  The next pointer is no longer required.

The ops pointers are stored at the end of the array as they are only
used in the register/unregister path and in the legacy br_netfilter code.

nf_unregister_net_hooks() is slower than needed as it just calls
nf_unregister_net_hook in a loop (i.e. at least n synchronize_net()
calls), this will be addressed in followup patch.

Test setup:
 - ixgbe 10gbit
 - netperf UDP_STREAM, 64 byte packets
 - 5 hooks: (raw + mangle prerouting, mangle+filter input, inet filter):
empty mangle and raw prerouting, mangle and filter input hooks:
353.9
this patch:
364.2

Signed-off-by: Aaron Conole <aconole@bytheb.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-08-28 17:44:00 +02:00
Florian Westphal cf56c2f892 netfilter: remove old pre-netns era hook api
no more users in the tree, remove this.

The old api is racy wrt. module removal, all users have been converted
to the netns-aware api.

The old api pretended we still have global hooks but that has not been
true for a long time.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-07-17 17:01:10 +02:00
Aaron Conole d415b9eb76 netfilter: decouple nf_hook_entry and nf_hook_ops
During nfhook traversal we only need a very small subset of
nf_hook_ops members.

We need:
- next element
- hook function to call
- hook function priv argument

Bridge netfilter also needs 'thresh'; can be obtained via ->orig_ops.

nf_hook_entry struct is now 32 bytes on x86_64.

A followup patch will turn the run-time list into an array that only
stores hook functions plus their priv arguments, eliminating the ->next
element.

Suggested-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Aaron Conole <aconole@bytheb.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-12-06 21:42:16 +01:00
Aaron Conole 0aa8c57a04 netfilter: introduce accessor functions for hook entries
This allows easier future refactoring.

Signed-off-by: Aaron Conole <aconole@bytheb.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-12-06 21:42:15 +01:00
Pablo Neira Ayuso 01886bd91f netfilter: remove hook_entries field from nf_hook_state
This field is only useful for nf_queue, so store it in the
nf_queue_entry structure instead, away from the core path. Pass
hook_head to nf_hook_slow().

Since we always have a valid entry on the first iteration in
nf_iterate(), we can use 'do { ... } while (entry)' loop instead.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-11-03 11:52:58 +01:00
Pablo Neira Ayuso 1610a73c41 netfilter: kill NF_HOOK_THRESH() and state->tresh
Patch c5136b15ea ("netfilter: bridge: add and use br_nf_hook_thresh")
introduced br_nf_hook_thresh().

Replace NF_HOOK_THRESH() by br_nf_hook_thresh from
br_nf_forward_finish(), so we have no more callers for this macro.

As a result, state->thresh and explicit thresh parameter in the hook
state structure is not required anymore. And we can get rid of
skip-hook-under-thresh loop in nf_iterate() in the core path that is
only used by br_netfilter to search for the filter hook.

Suggested-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-11-03 10:56:12 +01:00
Pablo Neira Ayuso f20fbc0717 Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
Conflicts:
	net/netfilter/core.c
	net/netfilter/nf_tables_netdev.c

Resolve two conflicts before pull request for David's net-next tree:

1) Between c73c248490 ("netfilter: nf_tables_netdev: remove redundant
   ip_hdr assignment") from the net tree and commit ddc8b6027a
   ("netfilter: introduce nft_set_pktinfo_{ipv4, ipv6}_validate()").

2) Between e8bffe0cf9 ("net: Add _nf_(un)register_hooks symbols") and
   Aaron Conole's patches to replace list_head with single linked list.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-09-25 23:34:19 +02:00
Aaron Conole e3b37f11e6 netfilter: replace list_head with single linked list
The netfilter hook list never uses the prev pointer, and so can be trimmed to
be a simple singly-linked list.

In addition to having a more light weight structure for hook traversal,
struct net becomes 5568 bytes (down from 6400) and struct net_device becomes
2176 bytes (down from 2240).

Signed-off-by: Aaron Conole <aconole@bytheb.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-09-25 14:38:48 +02:00
Florian Westphal fe72926b79 netfilter: call nf_hook_state_init with rcu_read_lock held
This makes things simpler because we can store the head of the list
in the nf_state structure without worrying about concurrent add/delete
of hook elements from the list.

A future commit will make use of this to implement a simpler
linked-list.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Aaron Conole <aconole@bytheb.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-09-24 21:25:49 +02:00
Mahesh Bandewar e8bffe0cf9 net: Add _nf_(un)register_hooks symbols
Add _nf_register_hooks() and _nf_unregister_hooks() calls which allow
caller to hold RTNL mutex.

Signed-off-by: Mahesh Bandewar <maheshb@google.com>
CC: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-19 01:25:22 -04:00
Florian Westphal af4610c395 netfilter: don't call hooks unless needed
With the previous patches in place, a netns nf_hook_list might be empty,
even if e.g. init_net performs filtering.

Thus change nf_hook_thresh to check the hook_list as well before
initializing hook_state and calling nf_hook_slow().

We still make use of static keys; if no netfilter modules are loaded
list is guaranteed to be empty.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-03-02 20:05:26 +01:00
Arnd Bergmann 008027c31d netfilter: turn NF_HOOK into an inline function
A recent change to the dst_output handling caused a new warning
when the call to NF_HOOK() is the only used of a local variable
passed as 'dev', and CONFIG_NETFILTER is disabled:

net/ipv6/ip6_output.c: In function 'ip6_output':
net/ipv6/ip6_output.c:135:21: warning: unused variable 'dev' [-Wunused-variable]

The reason for this is that the NF_HOOK macro in this case does
not reference the variable at all, and the call to dev_net(dev)
got removed from the ip6_output function. To avoid that warning now
and in the future, this changes the macro into an equivalent
inline function, which tells the compiler that the variable is
passed correctly but still unused.

The dn_forward function apparently had the same problem in
the past and added a local workaround that no longer works
with the inline function. In order to avoid a regression, we
have to also remove the #ifdef from decnet in the same patch.

Fixes: ede2059dba ("dst: Pass net into dst->output")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-10-16 18:45:36 +02:00
Florian Westphal 2ffbceb2b0 netfilter: remove hook owner refcounting
since commit 8405a8fff3 ("netfilter: nf_qeueue: Drop queue entries on
nf_unregister_hook") all pending queued entries are discarded.

So we can simply remove all of the owner handling -- when module is
removed it also needs to unregister all its hooks.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-10-16 18:21:39 +02:00
Ken-ichirou MATSUZAWA 224a05975e netfilter: ctnetlink: add const qualifier to nfnl_hook.get_ct
get_ct as is and will not update its skb argument, and users of
nfnl_ct_hook is currently only nfqueue, we can add const qualifier.

Signed-off-by: Ken-ichirou MATSUZAWA <chamas@h4.dion.ne.jp>
2015-10-05 17:32:13 +02:00
Ken-ichirou MATSUZAWA a4b4766c3c netfilter: nfnetlink_queue: rename related to nfqueue attaching conntrack info
The idea of this series of patch is to attach conntrack information to
nflog like nfqueue has already done. nfqueue conntrack info attaching
basis is generic, rename those names to generic one, glue.

Signed-off-by: Ken-ichirou MATSUZAWA <chamas@h4.dion.ne.jp>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-10-05 17:32:11 +02:00
Pablo Neira Ayuso b7bd1809e0 netfilter: nfnetlink_queue: get rid of nfnetlink_queue_ct.c
The original intention was to avoid dependencies between nfnetlink_queue and
conntrack without ifdef pollution. However, we can achieve this by moving the
conntrack dependent code into ctnetlink and keep some glue code to access the
nfq_ct indirection from nfqueue.

After this patch, the nfq_ct indirection is always compiled in the netfilter
core to avoid polluting nfqueue with ifdefs. Thus, if nf_conntrack is not
compiled this results in only 8-bytes of memory waste in x86_64.

This patch also adds ctnetlink_nfqueue_seqadj() to avoid that the nf_conn
structure layout if exposed to nf_queue, which creates another dependency with
nf_conntrack at compilation time.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-10-04 21:45:44 +02:00
Eric W. Biederman d815d90bbb netfilter: Push struct net down into nf_afinfo.reroute
The network namespace is needed when routing a packet.
Stop making nf_afinfo.reroute guess which network namespace
is the proper namespace to route the packet in.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-09-29 20:21:31 +02:00
Eric W. Biederman 06198b34a3 netfilter: Pass priv instead of nf_hook_ops to netfilter hooks
Only pass the void *priv parameter out of the nf_hook_ops.  That is
all any of the functions are interested now, and by limiting what is
passed it becomes simpler to change implementation details.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-09-18 22:00:16 +02:00
Eric W. Biederman 0c4b51f005 netfilter: Pass net into okfn
This is immediately motivated by the bridge code that chains functions that
call into netfilter.  Without passing net into the okfns the bridge code would
need to guess about the best expression for the network namespace to process
packets in.

As net is frequently one of the first things computed in continuation functions
after netfilter has done it's job passing in the desired network namespace is in
many cases a code simplification.

To support this change the function dst_output_okfn is introduced to
simplify passing dst_output as an okfn.  For the moment dst_output_okfn
just silently drops the struct net.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-17 17:18:37 -07:00
Eric W. Biederman 29a26a5680 netfilter: Pass struct net into the netfilter hooks
Pass a network namespace parameter into the netfilter hooks.  At the
call site of the netfilter hooks the path a packet is taking through
the network stack is well known which allows the network namespace to
be easily and reliabily.

This allows the replacement of magic code like
"dev_net(state->in?:state->out)" that appears at the start of most
netfilter hooks with "state->net".

In almost all cases the network namespace passed in is derived
from the first network device passed in, guaranteeing those
paths will not see any changes in practice.

The exceptions are:
xfrm/xfrm_output.c:xfrm_output_resume()         xs_net(skb_dst(skb)->xfrm)
ipvs/ip_vs_xmit.c:ip_vs_nat_send_or_cont()      ip_vs_conn_net(cp)
ipvs/ip_vs_xmit.c:ip_vs_send_or_cont()          ip_vs_conn_net(cp)
ipv4/raw.c:raw_send_hdrinc()                    sock_net(sk)
ipv6/ip6_output.c:ip6_xmit()			sock_net(sk)
ipv6/ndisc.c:ndisc_send_skb()                   dev_net(skb->dev) not dev_net(dst->dev)
ipv6/raw.c:raw6_send_hdrinc()                   sock_net(sk)
br_netfilter_hooks.c:br_nf_pre_routing_finish() dev_net(skb->dev) before skb->dev is set to nf_bridge->physindev

In all cases these exceptions seem to be a better expression for the
network namespace the packet is being processed in then the historic
"dev_net(in?in:out)".  I am documenting them in case something odd
pops up and someone starts trying to track down what happened.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-17 17:18:37 -07:00
Eric W. Biederman 7a7735044e netfilter: Pass net to nf_hook_thresh
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-17 17:18:32 -07:00
Eric W. Biederman b11b1f652d netfilter: Store net in nf_hook_state
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-17 17:18:32 -07:00
Eric W. Biederman fb884253a9 netfilter: Remove !CONFIG_NETFITLER definition of nf_hook_thresh
The !CONFIG_NETFILTER definition of nf_hook_thresh calls okfn when
the CONFIG_NETFITLER defintion does not, making it buggy.

As the !CONFIG_NETFILTER defintion of nf_hook_thresh is not used remove
it rather than fix it.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-17 17:18:32 -07:00
Daniel Borkmann 62da98656b netfilter: nf_conntrack: make nf_ct_zone_dflt built-in
Fengguang reported, that some randconfig generated the following linker
issue with nf_ct_zone_dflt object involved:

  [...]
  CC      init/version.o
  LD      init/built-in.o
  net/built-in.o: In function `ipv4_conntrack_defrag':
  nf_defrag_ipv4.c:(.text+0x93e95): undefined reference to `nf_ct_zone_dflt'
  net/built-in.o: In function `ipv6_defrag':
  nf_defrag_ipv6_hooks.c:(.text+0xe3ffe): undefined reference to `nf_ct_zone_dflt'
  make: *** [vmlinux] Error 1

Given that configurations exist where we have a built-in part, which is
accessing nf_ct_zone_dflt such as the two handlers nf_ct_defrag_user()
and nf_ct6_defrag_user(), and a part that configures nf_conntrack as a
module, we must move nf_ct_zone_dflt into a fixed, guaranteed built-in
area when netfilter is configured in general.

Therefore, split the more generic parts into a common header under
include/linux/netfilter/ and move nf_ct_zone_dflt into the built-in
section that already holds parts related to CONFIG_NF_CONNTRACK in the
netfilter core. This fixes the issue on my side.

Fixes: 308ac9143e ("netfilter: nf_conntrack: push zone object into functions")
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-02 16:32:56 -07:00
Pablo Neira Ayuso 3bbd14e0a2 netfilter: rename local nf_hook_list to hook_list
085db2c045 ("netfilter: Per network namespace netfilter hooks.") introduced a
new nf_hook_list that is global, so let's avoid this overlap.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
2015-07-23 16:18:35 +02:00
Florian Westphal e7c8899f3e netfilter: move tee_active to core
This prepares for a TEE like expression in nftables.
We want to ensure only one duplicate is sent, so both will
use the same percpu variable to detect duplication.

The other use case is detection of recursive call to xtables, but since
we don't want dependency from nft to xtables core its put into core.c
instead of the x_tables core.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-07-15 18:18:05 +02:00
Eric W. Biederman 085db2c045 netfilter: Per network namespace netfilter hooks.
- Add a new set of functions for registering and unregistering per
  network namespace hooks.

- Modify the old global namespace hook functions to use the per
  network namespace hooks in their implementation, so their remains a
  single list that needs to be walked for any hook (this is important
  for keeping the hook priority working and for keeping the code
  walking the hooks simple).

- Only allow registering the per netdevice hooks in the network
  namespace where the network device lives.

- Dynamically allocate the structures in the per network namespace
  hook list in nf_register_net_hook, and unregister them in
  nf_unregister_net_hook.

  Dynamic allocate is required somewhere as the number of network
  namespaces are not fixed so we might as well allocate them in the
  registration function.

  The chain of registered hooks on any list is expected to be small so
  the cost of walking that list to find the entry we are unregistering
  should also be small.

  Performing the management of the dynamically allocated list entries
  in the registration and unregistration functions keeps the complexity
  from spreading.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2015-07-15 18:17:26 +02:00
Eric W. Biederman 70aa996601 netfilter: kill nf_hooks_active
The function obscures what is going on in nf_hook_thresh and it's existence
requires computing the hook list twice.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-07-15 17:51:42 +02:00
Pablo Neira Ayuso a263653ed7 netfilter: don't pull include/linux/netfilter.h from netns headers
This pulls the full hook netfilter definitions from all those that include
net_namespace.h.

Instead let's just include the bare minimum required in the new
linux/netfilter_defs.h file, and use it from the netfilter netns header files.

I also needed to include in.h and in6.h from linux/netfilter.h otherwise we hit
this compilation error:

In file included from include/linux/netfilter_defs.h:4:0,
                 from include/net/netns/netfilter.h:4,
                 from include/net/net_namespace.h:22,
                 from include/linux/netdevice.h:43,
                 from net/netfilter/nfnetlink_queue_core.c:23:
include/uapi/linux/netfilter.h:76:17: error: field ‘in’ has incomplete type struct in_addr in;

And also explicit include linux/netfilter.h in several spots.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2015-06-18 21:14:31 +02:00