Commit Graph

685 Commits

Author SHA1 Message Date
Patrick McHardy 53b70287dd netfilter: nf_tables: fix overrun in nf_tables_set_alloc_name()
The map that is used to allocate anonymous sets is indeed
BITS_PER_BYTE * PAGE_SIZE long.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2014-02-05 17:46:07 +01:00
Patrick McHardy 3dd7279fb6 netfilter: nf_tables: fix oops when deleting a chain with references
The following commands trigger an oops:

 # nft -i
 nft> add table filter
 nft> add chain filter input { type filter hook input priority 0; }
 nft> add chain filter test
 nft> add rule filter input jump test
 nft> delete chain filter test

We need to check the chain use counter before allowing destruction since
we might have references from sets or jump rules.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=69341
Reported-by: Matthew Ife <deleriux1@gmail.com>
Tested-by: Matthew Ife <deleriux1@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2014-02-05 13:16:17 +01:00
Pablo Neira Ayuso 8f46df184c netfilter: nf_tables: fix missing byteorder conversion in policy
When fetching the policy attribute, the byteorder conversion was
missing, breaking the chain policy setting.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2014-01-10 18:26:13 +01:00
Patrick McHardy 44a6f0df03 netfilter: nf_tables: prohibit deletion of a table with existing sets
We currently leak the set memory when deleting a table that still has
sets in it. Return EBUSY when attempting to delete a table with sets.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2014-01-09 20:17:16 +01:00
Patrick McHardy 7047f9d052 netfilter: nf_tables: take AF module reference when creating a table
The table refers to data of the AF module, so we need to make sure the
module isn't unloaded while the table exists.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2014-01-09 20:17:16 +01:00
Patrick McHardy c5c1f975ad netfilter: nf_tables: perform flags validation before table allocation
Simplifies error handling. Additionally use the correct type u32 for the
host byte order flags value.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2014-01-09 20:17:15 +01:00
Patrick McHardy fa2c1de0bb netfilter: nf_tables: minor nf_chain_type cleanups
Minor nf_chain_type cleanups:

- reorder struct to plug a hoe
- rename struct module member to "owner" for consistency
- rename nf_hookfn array to "hooks" for consistency
- reorder initializers for better readability

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2014-01-09 20:17:15 +01:00
Patrick McHardy 2a37d755b8 netfilter: nf_tables: constify chain type definitions and pointers
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2014-01-09 20:17:15 +01:00
Patrick McHardy 93b0806f00 netfilter: nf_tables: replay request after dropping locks to load chain type
To avoid races, we need to replay to request after dropping the nfnl_mutex
to auto-load the chain type module.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2014-01-09 20:17:14 +01:00
Patrick McHardy baae3e62f3 netfilter: nf_tables: fix chain type module reference handling
The chain type module reference handling makes no sense at all: we take
a reference immediately when the module is registered, preventing the
module from ever being unloaded.

Fix by taking a reference when we're actually creating a chain of the
chain type and release the reference when destroying the chain.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2014-01-09 20:17:14 +01:00
Patrick McHardy 758206760c netfilter: nf_tables: fix check for table overflow
The table use counter is only increased for new chains, so move the check
to the correct position.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2014-01-09 20:17:13 +01:00
Patrick McHardy 4401a86200 netfilter: nf_tables: restore chain change atomicity
Chain counter validation is performed after the chain policy has
potentially been changed. Move counter validation/setting before
changing of the chain policy to fix this.

Additionally fix a memory leak if chain counter allocation fails
for new chains, remove an unnecessary free_percpu() and move
counter allocation for new chains

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2014-01-09 20:17:13 +01:00
Patrick McHardy 57de2a0cd9 netfilter: nf_tables: split chain policy validation from actually setting it
Currently nf_tables_newchain() atomicity is broken because of having
validation of some netlink attributes performed after changing attributes
of the chain. The chain policy is (currently) fine, but split it up as
preparation for the following fixes and to avoid future mistakes.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2014-01-09 20:17:13 +01:00
Patrick McHardy 115a60b173 netfilter: nf_tables: add support for multi family tables
Add support to register chains to multiple hooks for different address
families for mixed IPv4/IPv6 tables.

Signed-off-by: Patrick McHardy <kaber@trash.net>
2014-01-07 23:55:46 +01:00
Patrick McHardy 3b088c4bc0 netfilter: nf_tables: make chain types override the default AF functions
Currently the AF-specific hook functions override the chain-type specific
hook functions. That doesn't make too much sense since the chain types
are a special case of the AF-specific hooks.

Make the AF-specific hook functions the default and make the optional
chain type hooks override them.

As a side effect, the necessary code restructuring reduces the code size,
f.i. in case of nf_tables_ipv4.o:

  nf_tables_ipv4_init_net   |  -24
  nft_do_chain_ipv4         | -113
 2 functions changed, 137 bytes removed, diff: -137

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2014-01-07 23:50:43 +01:00
David S. Miller 56a4342dfe Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	drivers/net/ethernet/qlogic/qlcnic/qlcnic_sriov_pf.c
	net/ipv6/ip6_tunnel.c
	net/ipv6/ip6_vti.c

ipv6 tunnel statistic bug fixes conflicting with consolidation into
generic sw per-cpu net stats.

qlogic conflict between queue counting bug fix and the addition
of multiple MAC address support.

Signed-off-by: David S. Miller <davem@davemloft.net>
2014-01-06 17:37:45 -05:00
David S. Miller 9aa28f2b71 Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nftables
Pablo Neira Ayuso says: <pablo@netfilter.org>

====================
nftables updates for net-next

The following patchset contains nftables updates for your net-next tree,
they are:

* Add set operation to the meta expression by means of the select_ops()
  infrastructure, this allows us to set the packet mark among other things.
  From Arturo Borrero Gonzalez.

* Fix wrong format in sscanf in nf_tables_set_alloc_name(), from Daniel
  Borkmann.

* Add new queue expression to nf_tables. These comes with two previous patches
  to prepare this new feature, one to add mask in nf_tables_core to
  evaluate the queue verdict appropriately and another to refactor common
  code with xt_NFQUEUE, from Eric Leblond.

* Do not hide nftables from Kconfig if nfnetlink is not enabled, also from
  Eric Leblond.

* Add the reject expression to nf_tables, this adds the missing TCP RST
  support. It comes with an initial patch to refactor common code with
  xt_NFQUEUE, again from Eric Leblond.

* Remove an unused variable assignment in nf_tables_dump_set(), from Michal
  Nazarewicz.

* Remove the nft_meta_target code, now that Arturo added the set operation
  to the meta expression, from me.

* Add help information for nf_tables to Kconfig, also from me.

* Allow to dump all sets by specifying NFPROTO_UNSPEC, similar feature is
  available to other nf_tables objects, requested by Arturo, from me.

* Expose the table usage counter, so we can know how many chains are using
  this table without dumping the list of chains, from Tomasz Bursztyka.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2014-01-06 13:29:30 -05:00
Pablo Neira Ayuso c9c8e48597 netfilter: nf_tables: dump sets in all existing families
This patch allows you to dump all sets available in all of
the registered families. This allows you to use NFPROTO_UNSPEC
to dump all existing sets, similarly to other existing table,
chain and rule operations.

This patch is based on original patch from Arturo Borrero
González.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2014-01-04 00:23:11 +01:00
Michal Nazarewicz 720e0dfa3a netfilter: nf_tables: remove unused variable in nf_tables_dump_set()
The nfmsg variable is not used (except in sizeof operator which does
not care about its value) between the first and second time it is
assigned the value.  Furthermore, nlmsg_data has no side effects, so
the assignment can be safely removed.

Signed-off-by: Michal Nazarewicz <mina86@mina86.com>
Cc: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2014-01-03 22:51:14 +01:00
Daniel Borkmann 1466291790 netfilter: nf_tables: fix type in parsing in nf_tables_set_alloc_name()
In nf_tables_set_alloc_name(), we are trying to find a new, unused
name for our new set and interate through the list of present sets.
As far as I can see, we're using format string %d to parse already
present names in order to mark their presence in a bitmap, so that
we can later on find the first 0 in that map to assign the new set
name to. We should rather use a temporary variable of type int to
store the result of sscanf() to, and for making sanity checks on.

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2014-01-03 22:50:59 +01:00
Pablo Neira Ayuso 2ee0d3c80f netfilter: nf_tables: fix wrong datatype in nft_validate_data_load()
This patch fixes dictionary mappings, eg.

 add rule ip filter input meta dnat set tcp dport map { 22 => 1.1.1.1, 23 => 2.2.2.2 }

The kernel was returning -EINVAL in nft_validate_data_load() since
the type of the set element data that is passed was the real userspace
datatype instead of NFT_DATA_VALUE.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-12-28 22:32:28 +01:00
Pablo Neira Ayuso d201297561 netfilter: nf_tables: fix oops when updating table with user chains
This patch fixes a crash while trying to deactivate a table that
contains user chains. You can reproduce it via:

% nft add table table1
% nft add chain table1 chain1
% nft-table-upd ip table1 dormant

[  253.021026] BUG: unable to handle kernel NULL pointer dereference at 0000000000000030
[  253.021114] IP: [<ffffffff8134cebd>] nf_register_hook+0x35/0x6f
[  253.021167] PGD 30fa5067 PUD 30fa2067 PMD 0
[  253.021208] Oops: 0000 [#1] SMP
[...]
[  253.023305] Call Trace:
[  253.023331]  [<ffffffffa0885020>] nf_tables_newtable+0x11c/0x258 [nf_tables]
[  253.023385]  [<ffffffffa0878592>] nfnetlink_rcv_msg+0x1f4/0x226 [nfnetlink]
[  253.023438]  [<ffffffffa0878418>] ? nfnetlink_rcv_msg+0x7a/0x226 [nfnetlink]
[  253.023491]  [<ffffffffa087839e>] ? nfnetlink_bind+0x45/0x45 [nfnetlink]
[  253.023542]  [<ffffffff8134b47e>] netlink_rcv_skb+0x3c/0x88
[  253.023586]  [<ffffffffa0878973>] nfnetlink_rcv+0x3af/0x3e4 [nfnetlink]
[  253.023638]  [<ffffffff813fb0d4>] ? _raw_read_unlock+0x22/0x34
[  253.023683]  [<ffffffff8134af17>] netlink_unicast+0xe2/0x161
[  253.023727]  [<ffffffff8134b29a>] netlink_sendmsg+0x304/0x332
[  253.023773]  [<ffffffff8130d250>] __sock_sendmsg_nosec+0x25/0x27
[  253.023820]  [<ffffffff8130fb93>] sock_sendmsg+0x5a/0x7b
[  253.023861]  [<ffffffff8130d5d5>] ? copy_from_user+0x2a/0x2c
[  253.023905]  [<ffffffff8131066f>] ? move_addr_to_kernel+0x35/0x60
[  253.023952]  [<ffffffff813107b3>] SYSC_sendto+0x119/0x15c
[  253.023995]  [<ffffffff81401107>] ? sysret_check+0x1b/0x56
[  253.024039]  [<ffffffff8108dc30>] ? trace_hardirqs_on_caller+0x140/0x1db
[  253.024090]  [<ffffffff8120164e>] ? trace_hardirqs_on_thunk+0x3a/0x3f
[  253.024141]  [<ffffffff81310caf>] SyS_sendto+0x9/0xb
[  253.026219]  [<ffffffff814010e2>] system_call_fastpath+0x16/0x1b

Reported-by: Alex Wei <alex.kern.mentor@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-12-28 12:18:16 +01:00
Pablo Neira Ayuso e38195bf32 netfilter: nf_tables: fix dumping with large number of sets
If not table name is specified, the dumping of the existing sets
may be incomplete with a sufficiently large number of sets and
tables. This patch fixes missing reset of the cursors after
finding the location of the last object that has been included
in the previous multi-part message.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-12-28 12:14:42 +01:00
Tomasz Bursztyka d8bcc768c8 netfilter: nf_tables: Expose the table usage counter via netlink
Userspace can therefore know whether a table is in use or not, and
by how many chains. Suggested by Pablo Neira Ayuso.

Signed-off-by: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-12-17 14:28:05 +01:00
Pablo Neira Ayuso cf9dc09d09 netfilter: nf_tables: fix missing rules flushing per table
This patch allows you to atomically remove all rules stored in
a table via the NFT_MSG_DELRULE command. You only need to indicate
the specific table and no chain to flush all rules stored in that
table.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-12-07 22:55:48 +01:00
Pablo Neira Ayuso b5bc89bfa0 netfilter: nf_tables: add trace support
This patch adds support for tracing the packet travel through
the ruleset, in a similar fashion to x_tables.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-10-14 18:01:02 +02:00
Pablo Neira Ayuso 0628b123c9 netfilter: nfnetlink: add batch support and use it from nf_tables
This patch adds a batch support to nfnetlink. Basically, it adds
two new control messages:

* NFNL_MSG_BATCH_BEGIN, that indicates the beginning of a batch,
  the nfgenmsg->res_id indicates the nfnetlink subsystem ID.

* NFNL_MSG_BATCH_END, that results in the invocation of the
  ss->commit callback function. If not specified or an error
  ocurred in the batch, the ss->abort function is invoked
  instead.

The end message represents the commit operation in nftables, the
lack of end message results in an abort. This patch also adds the
.call_batch function that is only called from the batch receival
path.

This patch adds atomic rule updates and dumps based on
bitmask generations. This allows to atomically commit a set of
rule-set updates incrementally without altering the internal
state of existing nf_tables expressions/matches/targets.

The idea consists of using a generation cursor of 1 bit and
a bitmask of 2 bits per rule. Assuming the gencursor is 0,
then the genmask (expressed as a bitmask) can be interpreted
as:

00 active in the present, will be active in the next generation.
01 inactive in the present, will be active in the next generation.
10 active in the present, will be deleted in the next generation.
 ^
 gencursor

Once you invoke the transition to the next generation, the global
gencursor is updated:

00 active in the present, will be active in the next generation.
01 active in the present, needs to zero its future, it becomes 00.
10 inactive in the present, delete now.
^
gencursor

If a dump is in progress and nf_tables enters a new generation,
the dump will stop and return -EBUSY to let userspace know that
it has to retry again. In order to invalidate dumps, a global
genctr counter is increased everytime nf_tables enters a new
generation.

This new operation can be used from the user-space utility
that controls the firewall, eg.

nft -f restore

The rule updates contained in `file' will be applied atomically.

cat file
-----
add filter INPUT ip saddr 1.1.1.1 counter accept #1
del filter INPUT ip daddr 2.2.2.2 counter drop   #2
-EOF-

Note that the rule 1 will be inactive until the transition to the
next generation, the rule 2 will be evicted in the next generation.

There is a penalty during the rule update due to the branch
misprediction in the packet matching framework. But that should be
quickly resolved once the iteration over the commit list that
contain rules that require updates is finished.

Event notification happens once the rule-set update has been
committed. So we skip notifications is case the rule-set update
is aborted, which can happen in case that the rule-set is tested
to apply correctly.

This patch squashed the following patches from Pablo:

* nf_tables: atomic rule updates and dumps
* nf_tables: get rid of per rule list_head for commits
* nf_tables: use per netns commit list
* nfnetlink: add batch support and use it from nf_tables
* nf_tables: all rule updates are transactional
* nf_tables: attach replacement rule after stale one
* nf_tables: do not allow deletion/replacement of stale rules
* nf_tables: remove unused NFTA_RULE_FLAGS

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-10-14 18:01:01 +02:00
Eric Leblond 5e94846686 netfilter: nf_tables: add insert operation
This patch adds a new rule attribute NFTA_RULE_POSITION which is
used to store the position of a rule relatively to the others.
By providing the create command and specifying the position, the
rule is inserted after the rule with the handle equal to the
provided position.

Regarding notification, the position attribute specifies the
handle of the previous rule to make sure we don't point to any
stale rule in notifications coming from the commit path.

This patch includes the following fix from Pablo:

* nf_tables: fix rule deletion event reporting

Signed-off-by: Eric Leblond <eric@regit.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-10-14 18:01:00 +02:00
Pablo Neira Ayuso 99633ab29b netfilter: nf_tables: complete net namespace support
Register family per netnamespace to ensure that sets are
only visible in its approapriate namespace.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-10-14 18:00:59 +02:00
Pablo Neira Ayuso 9ddf632357 netfilter: nf_tables: add support for dormant tables
This patch allows you to temporarily disable an entire table.
You can change the state of a dormant table via NFT_MSG_NEWTABLE
messages. Using this operation you can wake up a table, so their
chains are registered.

This provides atomicity at chain level. Thus, the rule-set of one
chain is applied at once, avoiding any possible intermediate state
in every chain. Still, the chains that belongs to a table are
registered consecutively. This also allows you to have inactive
tables in the kernel.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-10-14 18:00:57 +02:00
Pablo Neira Ayuso 0ca743a559 netfilter: nf_tables: add compatibility layer for x_tables
This patch adds the x_tables compatibility layer. This allows you
to use existing x_tables matches and targets from nf_tables.

This compatibility later allows us to use existing matches/targets
for features that are still missing in nf_tables. We can progressively
replace them with native nf_tables extensions. It also provides the
userspace compatibility software that allows you to express the
rule-set using the iptables syntax but using the nf_tables kernel
components.

In order to get this compatibility layer working, I've done the
following things:

* add NFNL_SUBSYS_NFT_COMPAT: this new nfnetlink subsystem is used
to query the x_tables match/target revision, so we don't need to
use the native x_table getsockopt interface.

* emulate xt structures: this required extending the struct nft_pktinfo
to include the fragment offset, which is already obtained from
ip[6]_tables and that is used by some matches/targets.

* add support for default policy to base chains, required to emulate
  x_tables.

* add NFTA_CHAIN_USE attribute to obtain the number of references to
  chains, required by x_tables emulation.

* add chain packet/byte counters using per-cpu.

* support 32-64 bits compat.

For historical reasons, this patch includes the following patches
that were posted in the netfilter-devel mailing list.

From Pablo Neira Ayuso:
* nf_tables: add default policy to base chains
* netfilter: nf_tables: add NFTA_CHAIN_USE attribute
* nf_tables: nft_compat: private data of target and matches in contiguous area
* nf_tables: validate hooks for compat match/target
* nf_tables: nft_compat: release cached matches/targets
* nf_tables: x_tables support as a compile time option
* nf_tables: fix alias for xtables over nftables module
* nf_tables: add packet and byte counters per chain
* nf_tables: fix per-chain counter stats if no counters are passed
* nf_tables: don't bump chain stats
* nf_tables: add protocol and flags for xtables over nf_tables
* nf_tables: add ip[6]t_entry emulation
* nf_tables: move specific layer 3 compat code to nf_tables_ipv[4|6]
* nf_tables: support 32bits-64bits x_tables compat
* nf_tables: fix compilation if CONFIG_COMPAT is disabled

From Patrick McHardy:
* nf_tables: move policy to struct nft_base_chain
* nf_tables: send notifications for base chain policy changes

From Alexander Primak:
* nf_tables: remove the duplicate NF_INET_LOCAL_OUT

From Nicolas Dichtel:
* nf_tables: fix compilation when nf-netlink is a module

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-10-14 18:00:04 +02:00
Pablo Neira Ayuso 9370761c56 netfilter: nf_tables: convert built-in tables/chains to chain types
This patch converts built-in tables/chains to chain types that
allows you to deploy customized table and chain configurations from
userspace.

After this patch, you have to specify the chain type when
creating a new chain:

 add chain ip filter output { type filter hook input priority 0; }
                              ^^^^ ------

The existing chain types after this patch are: filter, route and
nat. Note that tables are just containers of chains with no specific
semantics, which is a significant change with regards to iptables.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-10-14 17:16:11 +02:00
Patrick McHardy ef1f7df917 netfilter: nf_tables: expression ops overloading
Split the expression ops into two parts and support overloading of
the runtime expression ops based on the requested function through
a ->select_ops() callback.

This can be used to provide optimized implementations, for instance
for loading small aligned amounts of data from the packet or inlining
frequently used operations into the main evaluation loop.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-10-14 17:16:08 +02:00
Patrick McHardy 20a69341f2 netfilter: nf_tables: add netlink set API
This patch adds the new netlink API for maintaining nf_tables sets
independently of the ruleset. The API supports the following operations:

- creation of sets
- deletion of sets
- querying of specific sets
- dumping of all sets

- addition of set elements
- removal of set elements
- dumping of all set elements

Sets are identified by name, each table defines an individual namespace.
The name of a set may be allocated automatically, this is mostly useful
in combination with the NFT_SET_ANONYMOUS flag, which destroys a set
automatically once the last reference has been released.

Sets can be marked constant, meaning they're not allowed to change while
linked to a rule. This allows to perform lockless operation for set
types that would otherwise require locking.

Additionally, if the implementation supports it, sets can (as before) be
used as maps, associating a data value with each key (or range), by
specifying the NFT_SET_MAP flag and can be used for interval queries by
specifying the NFT_SET_INTERVAL flag.

Set elements are added and removed incrementally. All element operations
support batching, reducing netlink message and set lookup overhead.

The old "set" and "hash" expressions are replaced by a generic "lookup"
expression, which binds to the specified set. Userspace is not aware
of the actual set implementation used by the kernel anymore, all
configuration options are generic.

Currently the implementation selection logic is largely missing and the
kernel will simply use the first registered implementation supporting the
requested operation. Eventually, the plan is to have userspace supply a
description of the data characteristics and select the implementation
based on expected performance and memory use.

This patch includes the new 'lookup' expression to look up for element
matching in the set.

This patch includes kernel-doc descriptions for this set API and it
also includes the following fixes.

From Patrick McHardy:
* netfilter: nf_tables: fix set element data type in dumps
* netfilter: nf_tables: fix indentation of struct nft_set_elem comments
* netfilter: nf_tables: fix oops in nft_validate_data_load()
* netfilter: nf_tables: fix oops while listing sets of built-in tables
* netfilter: nf_tables: destroy anonymous sets immediately if binding fails
* netfilter: nf_tables: propagate context to set iter callback
* netfilter: nf_tables: add loop detection

From Pablo Neira Ayuso:
* netfilter: nf_tables: allow to dump all existing sets
* netfilter: nf_tables: fix wrong type for flags variable in newelem

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-10-14 17:16:07 +02:00
Patrick McHardy 96518518cc netfilter: add nftables
This patch adds nftables which is the intended successor of iptables.
This packet filtering framework reuses the existing netfilter hooks,
the connection tracking system, the NAT subsystem, the transparent
proxying engine, the logging infrastructure and the userspace packet
queueing facilities.

In a nutshell, nftables provides a pseudo-state machine with 4 general
purpose registers of 128 bits and 1 specific purpose register to store
verdicts. This pseudo-machine comes with an extensible instruction set,
a.k.a. "expressions" in the nftables jargon. The expressions included
in this patch provide the basic functionality, they are:

* bitwise: to perform bitwise operations.
* byteorder: to change from host/network endianess.
* cmp: to compare data with the content of the registers.
* counter: to enable counters on rules.
* ct: to store conntrack keys into register.
* exthdr: to match IPv6 extension headers.
* immediate: to load data into registers.
* limit: to limit matching based on packet rate.
* log: to log packets.
* meta: to match metainformation that usually comes with the skbuff.
* nat: to perform Network Address Translation.
* payload: to fetch data from the packet payload and store it into
  registers.
* reject (IPv4 only): to explicitly close connection, eg. TCP RST.

Using this instruction-set, the userspace utility 'nft' can transform
the rules expressed in human-readable text representation (using a
new syntax, inspired by tcpdump) to nftables bytecode.

nftables also inherits the table, chain and rule objects from
iptables, but in a more configurable way, and it also includes the
original datatype-agnostic set infrastructure with mapping support.
This set infrastructure is enhanced in the follow up patch (netfilter:
nf_tables: add netlink set API).

This patch includes the following components:

* the netlink API: net/netfilter/nf_tables_api.c and
  include/uapi/netfilter/nf_tables.h
* the packet filter core: net/netfilter/nf_tables_core.c
* the expressions (described above): net/netfilter/nft_*.c
* the filter tables: arp, IPv4, IPv6 and bridge:
  net/ipv4/netfilter/nf_tables_ipv4.c
  net/ipv6/netfilter/nf_tables_ipv6.c
  net/ipv4/netfilter/nf_tables_arp.c
  net/bridge/netfilter/nf_tables_bridge.c
* the NAT table (IPv4 only):
  net/ipv4/netfilter/nf_table_nat_ipv4.c
* the route table (similar to mangle):
  net/ipv4/netfilter/nf_table_route_ipv4.c
  net/ipv6/netfilter/nf_table_route_ipv6.c
* internal definitions under:
  include/net/netfilter/nf_tables.h
  include/net/netfilter/nf_tables_core.h
* It also includes an skeleton expression:
  net/netfilter/nft_expr_template.c
  and the preliminary implementation of the meta target
  net/netfilter/nft_meta_target.c

It also includes a change in struct nf_hook_ops to add a new
pointer to store private data to the hook, that is used to store
the rule list per chain.

This patch is based on the patch from Patrick McHardy, plus merged
accumulated cleanups, fixes and small enhancements to the nftables
code that has been done since 2009, which are:

From Patrick McHardy:
* nf_tables: adjust netlink handler function signatures
* nf_tables: only retry table lookup after successful table module load
* nf_tables: fix event notification echo and avoid unnecessary messages
* nft_ct: add l3proto support
* nf_tables: pass expression context to nft_validate_data_load()
* nf_tables: remove redundant definition
* nft_ct: fix maxattr initialization
* nf_tables: fix invalid event type in nf_tables_getrule()
* nf_tables: simplify nft_data_init() usage
* nf_tables: build in more core modules
* nf_tables: fix double lookup expression unregistation
* nf_tables: move expression initialization to nf_tables_core.c
* nf_tables: build in payload module
* nf_tables: use NFPROTO constants
* nf_tables: rename pid variables to portid
* nf_tables: save 48 bits per rule
* nf_tables: introduce chain rename
* nf_tables: check for duplicate names on chain rename
* nf_tables: remove ability to specify handles for new rules
* nf_tables: return error for rule change request
* nf_tables: return error for NLM_F_REPLACE without rule handle
* nf_tables: include NLM_F_APPEND/NLM_F_REPLACE flags in rule notification
* nf_tables: fix NLM_F_MULTI usage in netlink notifications
* nf_tables: include NLM_F_APPEND in rule dumps

From Pablo Neira Ayuso:
* nf_tables: fix stack overflow in nf_tables_newrule
* nf_tables: nft_ct: fix compilation warning
* nf_tables: nft_ct: fix crash with invalid packets
* nft_log: group and qthreshold are 2^16
* nf_tables: nft_meta: fix socket uid,gid handling
* nft_counter: allow to restore counters
* nf_tables: fix module autoload
* nf_tables: allow to remove all rules placed in one chain
* nf_tables: use 64-bits rule handle instead of 16-bits
* nf_tables: fix chain after rule deletion
* nf_tables: improve deletion performance
* nf_tables: add missing code in route chain type
* nf_tables: rise maximum number of expressions from 12 to 128
* nf_tables: don't delete table if in use
* nf_tables: fix basechain release

From Tomasz Bursztyka:
* nf_tables: Add support for changing users chain's name
* nf_tables: Change chain's name to be fixed sized
* nf_tables: Add support for replacing a rule by another one
* nf_tables: Update uapi nftables netlink header documentation

From Florian Westphal:
* nft_log: group is u16, snaplen u32

From Phil Oester:
* nf_tables: operational limit match

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-10-14 17:15:48 +02:00