The plain text logging is currently embedded into the xt_LOG target.
In order to be able to use the plain text logging from nft_log, as a
first step, this patch moves the family specific code to the following
files and Kconfig symbols:

1) net/ipv4/netfilter/nf_log_ip.c: CONFIG_NF_LOG_IPV4
2) net/ipv6/netfilter/nf_log_ip6.c: CONFIG_NF_LOG_IPV6
3) net/netfilter/nf_log_common.c: CONFIG_NF_LOG_COMMON

These new modules will be required by xt_LOG and nft_log. This patch
is based on original patch from Arturo Borrero Gonzalez.
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

This patch moves Eric Dumazet's log buffer implementation from the
xt_log.h header file to the core net/netfilter/nf_log.c. This also
includes the renaming of the structure and functions to avoid possible
undesired namespace clashes.

This change allows us to use it from the arp and bridge packet logging
implementation in follow up patches.

Now that legacy ulog targets are not available anymore in the tree, we
can have up to two possible loggers:

1) The plain text logging via kernel logging ring.
2) The nfnetlink_log infrastructure which delivers log messages
   to userspace.

This patch replaces the list of loggers by an array of two pointers
per family for each possible logger and it also introduces a new field
to the nf_logger structure which indicates the position in the logger
array (based on the logger type).

This prepares a follow up patch that consolidates the nf_log_packet()
interface by allowing to specify the logger as parameter.
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

This brings the (per-conntrack) ecache extension back to 24 bytes in size
(was 152 byte on x86_64 with lockdep on).

When event delivery fails, re-delivery is attempted via work queue.

Redelivery is attempted at least every 0.1 seconds, but can happen
more frequently if userspace is not congested.

The nf_ct_release_dying_list() function is removed.
With this patch, ownership of the to-be-redelivered conntracks
(on-dying-list-with-DYING-bit not yet set) is with the work queue,
which will release the references once event is out.

Joint work with Pablo Neira Ayuso.
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

kvfree() helper can make xt_free_table_info() much cleaner.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

Fix checkpatch warning:
WARNING: kfree(NULL) is safe this check is probably not required
Signed-off-by: NFabian Frederick <fabf@skynet.be>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

Replaced non-standard C use of Variable Length Arrays In Structs (VLAIS) in
xt_repldata.h with a C99 compliant flexible array member and then calculated
offsets to the other struct members. These other members aren't referenced by
name in this code, however this patch maintains the same memory layout and
padding as was previously accomplished using VLAIS.

Had the original structure been ordered differently, with the entries VLA at
the end, then it could have been a flexible member, and this patch would have
been a lot simpler. However since the data stored in this structure is
ultimately exported to userspace, the order of this structure can't be changed.

This patch makes no attempt to change the existing behavior, merely the way in
which the current layout is accomplished using standard C99 constructs. As such
the code can now be compiled with either gcc or clang.

This version of the patch removes the trailing alignment that the VLAIS
structure would allocate in order to simplify the patch.

Author: Mark Charlebois <charlebm@gmail.com>
Signed-off-by: NMark Charlebois <charlebm@gmail.com>
Signed-off-by: NBehan Webster <behanw@converseincode.com>
Signed-off-by: NVinícius Tinti <viniciustinti@gmail.com>

It is available since v3.15-rc5.

Cc: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Ideally, we would need to generate IP ID using a per destination IP
generator.

linux kernels used inet_peer cache for this purpose, but this had a huge
cost on servers disabling MTU discovery.

1) each inet_peer struct consumes 192 bytes

2) inetpeer cache uses a binary tree of inet_peer structs,
   with a nominal size of ~66000 elements under load.

3) lookups in this tree are hitting a lot of cache lines, as tree depth
   is about 20.

4) If server deals with many tcp flows, we have a high probability of
   not finding the inet_peer, allocating a fresh one, inserting it in
   the tree with same initial ip_id_count, (cf secure_ip_id())

5) We garbage collect inet_peer aggressively.

IP ID generation do not have to be 'perfect'

Goal is trying to avoid duplicates in a short period of time,
so that reassembly units have a chance to complete reassembly of
fragments belonging to one message before receiving other fragments
with a recycled ID.

We simply use an array of generators, and a Jenkin hash using the dst IP
as a key.

ipv6_select_ident() is put back into net/ipv6/ip6_output.c where it
belongs (it is only used from this file)

secure_ip_id() and secure_ipv6_id() no longer are needed.

Rename ip_select_ident_more() to ip_select_ident_segs() to avoid
unnecessary decrement/increment of the number of segments.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use GFP_ATOMIC allocations when sending removal notifications of
anonymous sets from rcu callback context. Sleeping in that context
is illegal.
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

Three changes to allow the deletion of several objects with dependencies
in one transaction, they are:

1) Introduce speculative counter increment/decrement that is undone in
   the abort path if required, thus we avoid hitting -EBUSY when deleting
   the chain. The counter updates are reverted in the abort path.

2) Increment/decrement table/chain use counter for each set/rule. We need
   this to fully rely on the use counters instead of the list content,
   eg. !list_empty(&chain->rules) which evaluate true in the middle of the
   transaction.

3) Decrement table use counter when an anonymous set is bound to the
   rule in the commit path. This avoids hitting -EBUSY when deleting
   the table that contains anonymous sets. The anonymous sets are released
   in the nf_tables_rule_destroy path. This should not be a problem since
   the rule already bumped the use counter of the chain, so the bound
   anonymous set reflects dependencies through the rule object, which
   already increases the chain use counter.

So the general assumption after this patch is that the use counters are
bumped by direct object dependencies.
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

There's no rbtree rcu version yet, so let's fall back on the spinlock
to protect the concurrent access of this structure both from user
(to update the set content) and kernel-space (in the packet path).
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

The patch c7c32e72 ("netfilter: nf_tables: defer all object release via
rcu") indicates that we always release deleted objects in the reverse
order, but that is only needed in the abort path. These are the two
possible scenarios when releasing objects:

1) Deletion scenario in the commit path: no need to release objects in
the reverse order since userspace already ensures that dependencies are
fulfilled), ie. userspace tells us to delete rule -> ... -> rule ->
chain -> table. In this case, we have to release the objects in the
*same order* as userspace provided.

2) Deletion scenario in the abort path: we have to iterate in the reverse
order to undo what it cannot be added, ie. userspace sent us a batch
that includes: table -> chain -> rule -> ... -> rule, and that needs to
be partially undone. In this case, we have to release objects in the
reverse order to ensure that the set and chain objects point to valid
rule and table objects.
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

The transaction needs to be placed at the end of the commit list,
otherwise event notifications are reordered and we may crash when
releasing object via call_rcu.

This problem was introduced in 60319eb1 ("netfilter: nf_tables: use new
transaction infrastructure to handle elements").
Reported-by: NArturo Borrero Gonzalez <arturo.borrero.glez@gmail.com>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

Allocation of memory need only to happen once, that is
after the proper checks on the NFACCT_FLAGS have been
done.  Otherwise the code can return without freeing
already allocated memory.
Signed-off-by: NMathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

Receiving a ICMP response to an IPIP packet in a non-linear skb could
cause a kernel panic in __skb_pull.

The problem was introduced in
commit f2edb9f7 ("ipvs: implement
passive PMTUD for IPIP packets").
Signed-off-by: NPeter Christensen <pch@ordbogen.com>
Acked-by: NJulian Anastasov <ja@ssi.bg>
Signed-off-by: NSimon Horman <horms@verge.net.au>

The sk_unattached_filter_create() API is used by BPF filters that
are not directly attached or related to sockets, and are used in
team, ptp, xt_bpf, cls_bpf, etc. As such all users do their own
internal managment of obtaining filter blocks and thus already
have them in kernel memory and set up before calling into
sk_unattached_filter_create(). As a result, due to __user annotation
in sock_fprog, sparse triggers false positives (incorrect type in
assignment [different address space]) when filters are set up before
passing them to sk_unattached_filter_create(). Therefore, let
sk_unattached_filter_create() API use sock_fprog_kern to overcome
this issue.
Signed-off-by: NDaniel Borkmann <dborkman@redhat.com>
Acked-by: NAlexei Starovoitov <ast@plumgrid.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Now that all objects are released in the reverse order via the
transaction infrastructure, we can enqueue the release via
call_rcu to save one synchronize_rcu. For small rule-sets loaded
via nft -f, it now takes around 50ms less here.
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

Instead of caching the original skbuff that contains the netlink
messages, this stores the netlink message sequence number, the
netlink portID and the report flag. This helps to prepare the
introduction of the object release via call_rcu.
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

Now that all these function are called from the commit path, we can
pass the context structure to reduce the amount of parameters in all
of the nf_tables_*_notify functions. This patch also removes unneeded
branches to check for skb, nlh and net that should be always set in
the context structure.
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

Leave the set content in consistent state if we fail to load the
batch. Use the new generic transaction infrastructure to achieve
this.
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

This patch speeds up rule-set updates and it also provides a way
to revert updates and leave things in consistent state in case that
the batch needs to be aborted.
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

So nf_tables_uptable() only takes one single parameter.
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

nf_tables_table_disable() always succeeds, make this function void.
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

This patch speeds up rule-set updates and it also introduces a way to
revert chain updates if the batch is aborted. The idea is to store the
changes in the transaction to apply that in the commit step.
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

Add new routines to encapsulate chain statistics allocation and
replacement.
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

This patch reworks the nf_tables API so set updates are included in
the same batch that contains rule updates. This speeds up rule-set
updates since we skip a dialog of four messages between kernel and
user-space (two on each direction), from:

 1) create the set and send netlink message to the kernel
 2) process the response from the kernel that contains the allocated name.
 3) add the set elements and send netlink message to the kernel.
 4) process the response from the kernel (to check for errors).

To:

 1) add the set to the batch.
 2) add the set elements to the batch.
 3) add the rule that points to the set.
 4) send batch to the kernel.

This also introduces an internal set ID (NFTA_SET_ID) that is unique
in the batch so set elements and rules can refer to new sets.

Backward compatibility has been only retained in userspace, this
means that new nft versions can talk to the kernel both in the new
and the old fashion.
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

The patch adds message type to the transaction to simplify the
commit the and abort routines. Yet another step forward in the
generalisation of the transaction infrastructure.
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

Move the commit and abort routines to the bottom of the source code
file. This change is required by the follow up patches that add the
set, chain and table transaction support.

This patch is just a cleanup to access several functions without
having to declare their prototypes.
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

This patch generalises the existing rule transaction infrastructure
so it can be used to handle set, table and chain object transactions
as well. The transaction provides a data area that stores private
information depending on the transaction type.
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

The new transaction infrastructure updates the family, table and chain
objects in the context structure, so let's deconstify them. While at it,
move the context structure initialization routine to the top of the
source file as it will be also used from the table and chain routines.
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

Add the corresponding trace if we have a full match in a non-terminal
rule. Note that the traces will look slightly different than in
x_tables since the log message after all expressions have been
evaluated (contrary to x_tables, that emits it before the target
action). This manifests in two differences in nf_tables wrt. x_tables:

1) The rule that enables the tracing is included in the trace.

2) If the rule emits some log message, that is shown before the
   trace log message.
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

As suggested by several people, rename local_df to ignore_df,
since it means "ignore df bit if it is set".

Cc: Maciej Żenczykowski <maze@google.com>
Cc: Florian Westphal <fw@strlen.de>
Cc: David S. Miller <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Acked-by: NMaciej Żenczykowski <maze@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Display "return" for implicit rule at the end of a non-base chain,
instead of when popping chain from the stack.
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

After returning from the chain that we just went to with no matchings,
we get a bogus rule number in the trace. To fix this, we would need
to iterate over the list of remaining rules in the chain to update the
rule number counter.

Patrick suggested to set this to the maximum value since the default
base chain policy is the very last action when the processing the base
chain is over.
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

Add missing code to trace goto actions.
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

This patch fixes a crash when trying to access the counters and the
default chain policy from the non-base chain that we have reached
via the goto chain. Fix this by falling back on the original base
chain after returning from the custom chain.

While fixing this, kill the inline function to account chain statistics
to improve source code readability.
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

Otherwise we start incrementing the rule number counter from the
previous chain iteration.
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

This bug manifests when calling the nft command line tool without
nf_tables kernel support.

kernel message:
[   44.071555] Netfilter messages via NETLINK v0.30.
[   44.072253] BUG: unable to handle kernel NULL pointer dereference at 0000000000000119
[   44.072264] IP: [<ffffffff8171db1f>] netlink_getsockbyportid+0xf/0x70
[   44.072272] PGD 7f2b74067 PUD 7f2b73067 PMD 0
[   44.072277] Oops: 0000 [#1] SMP
[...]
[   44.072369] Call Trace:
[   44.072373]  [<ffffffff8171fd81>] netlink_unicast+0x91/0x200
[   44.072377]  [<ffffffff817206c9>] netlink_ack+0x99/0x110
[   44.072381]  [<ffffffffa004b951>] nfnetlink_rcv+0x3c1/0x408 [nfnetlink]
[   44.072385]  [<ffffffff8171fde3>] netlink_unicast+0xf3/0x200
[   44.072389]  [<ffffffff817201ef>] netlink_sendmsg+0x2ff/0x740
[   44.072394]  [<ffffffff81044752>] ? __mmdrop+0x62/0x90
[   44.072398]  [<ffffffff816dafdb>] sock_sendmsg+0x8b/0xc0
[   44.072403]  [<ffffffff812f1af5>] ? copy_user_enhanced_fast_string+0x5/0x10
[   44.072406]  [<ffffffff816dbb6c>] ? move_addr_to_kernel+0x2c/0x50
[   44.072410]  [<ffffffff816db423>] ___sys_sendmsg+0x3c3/0x3d0
[   44.072415]  [<ffffffff811301ba>] ? handle_mm_fault+0xa9a/0xc60
[   44.072420]  [<ffffffff811362d6>] ? mmap_region+0x166/0x5a0
[   44.072424]  [<ffffffff817da84c>] ? __do_page_fault+0x1dc/0x510
[   44.072428]  [<ffffffff812b8b2c>] ? apparmor_capable+0x1c/0x60
[   44.072435]  [<ffffffff817d6e9a>] ? _raw_spin_unlock_bh+0x1a/0x20
[   44.072439]  [<ffffffff816dfc86>] ? release_sock+0x106/0x150
[   44.072443]  [<ffffffff816dc212>] __sys_sendmsg+0x42/0x80
[   44.072446]  [<ffffffff816dc262>] SyS_sendmsg+0x12/0x20
[   44.072450]  [<ffffffff817df616>] system_call_fastpath+0x1a/0x1f
Signed-off-by: NDenys Fedoryshchenko <nuclearcat@nuclearcat.com>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

Reduce copy-past a bit by adding a common helper.
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>