Граф коммитов

635 Коммитов

Автор SHA1 Сообщение Дата
Florian Westphal 20ff320246 netfilter: conntrack: pptp: use single option structure
Instead of exposing the four hooks individually use a sinle hook ops
structure.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2022-02-04 06:30:28 +01:00
Florian Westphal 6ae7989c9a netfilter: conntrack: avoid useless indirection during conntrack destruction
nf_ct_put() results in a usesless indirection:

nf_ct_put -> nf_conntrack_put -> nf_conntrack_destroy -> rcu readlock +
indirect call of ct_hooks->destroy().

There are two _put helpers:
nf_ct_put and nf_conntrack_put.  The latter is what should be used in
code that MUST NOT cause a linker dependency on the conntrack module
(e.g. calls from core network stack).

Everyone else should call nf_ct_put() instead.

A followup patch will convert a few nf_conntrack_put() calls to
nf_ct_put(), in particular from modules that already have a conntrack
dependency such as act_ct or even nf_conntrack itself.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2022-01-09 23:30:13 +01:00
Florian Westphal 7197743776 netfilter: conntrack: convert to refcount_t api
Convert nf_conn reference counting from atomic_t to refcount_t based api.
refcount_t api provides more runtime sanity checks and will warn on
certain constructs, e.g. refcount_inc() on a zero reference count, which
usually indicates use-after-free.

For this reason template allocation is changed to init the refcount to
1, the subsequenct add operations are removed.

Likewise, init_conntrack() is changed to set the initial refcount to 1
instead refcount_inc().

This is safe because the new entry is not (yet) visible to other cpus.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2022-01-09 23:30:13 +01:00
Jakub Kicinski 10905b4a68 Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf
Pablo Neira Ayuso says:

====================
Netfilter fixes for net

1) Protect nft_ct template with global mutex, from Pavel Skripkin.

2) Two recent commits switched inet rt and nexthop exception hashes
   from jhash to siphash. If those two spots are problematic then
   conntrack is affected as well, so switch voer to siphash too.
   While at it, add a hard upper limit on chain lengths and reject
   insertion if this is hit. Patches from Florian Westphal.

3) Fix use-after-scope in nf_socket_ipv6 reported by KASAN,
   from Benjamin Hesmans.

* git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf:
  netfilter: socket: icmp6: fix use-after-scope
  netfilter: refuse insertion if chain has grown too large
  netfilter: conntrack: switch to siphash
  netfilter: conntrack: sanitize table size default settings
  netfilter: nft_ct: protect nft_ct_pcpu_template_refcnt with mutex
====================

Link: https://lore.kernel.org/r/20210903163020.13741-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-09-03 16:20:37 -07:00
Florian Westphal d7e7747ac5 netfilter: refuse insertion if chain has grown too large
Also add a stat counter for this that gets exported both via old /proc
interface and ctnetlink.

Assuming the old default size of 16536 buckets and max hash occupancy of
64k, this results in 128k insertions (origin+reply), so ~8 entries per
chain on average.

The revised settings in this series will result in about two entries per
bucket on average.

This allows a hard-limit ceiling of 64.

This is not tunable at the moment, but its possible to either increase
nf_conntrack_buckets or decrease nf_conntrack_max to reduce average
lengths.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-08-30 11:52:21 +02:00
Jakub Kicinski f4083a752a Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Conflicts:

drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.h
  9e26680733 ("bnxt_en: Update firmware call to retrieve TX PTP timestamp")
  9e518f2580 ("bnxt_en: 1PPS functions to configure TSIO pins")
  099fdeda65 ("bnxt_en: Event handler for PPS events")

kernel/bpf/helpers.c
include/linux/bpf-cgroup.h
  a2baf4e8bb ("bpf: Fix potentially incorrect results with bpf_get_local_storage()")
  c7603cfa04 ("bpf: Add ambient BPF runtime context stored in current")

drivers/net/ethernet/mellanox/mlx5/core/pci_irq.c
  5957cc557d ("net/mlx5: Set all field of mlx5_irq before inserting it to the xarray")
  2d0b41a376 ("net/mlx5: Refcount mlx5_irq with integer")

MAINTAINERS
  7b637cd52f ("MAINTAINERS: fix Microchip CAN BUS Analyzer Tool entry typo")
  7d901a1e87 ("net: phy: add Maxlinear GPY115/21x/24x driver")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-08-13 06:41:22 -07:00
Florian Westphal fdacd57c79 netfilter: x_tables: never register tables by default
For historical reasons x_tables still register tables by default in the
initial namespace.
Only newly created net namespaces add the hook on demand.

This means that the init_net always pays hook cost, even if no filtering
rules are added (e.g. only used inside a single netns).

Note that the hooks are added even when 'iptables -L' is called.
This is because there is no way to tell 'iptables -A' and 'iptables -L'
apart at kernel level.

The only solution would be to register the table, but delay hook
registration until the first rule gets added (or policy gets changed).

That however means that counters are not hooked either, so 'iptables -L'
would always show 0-counters even when traffic is flowing which might be
unexpected.

This keeps table and hook registration consistent with what is already done
in non-init netns: first iptables(-save) invocation registers both table
and hooks.

This applies the same solution adopted for ebtables.
All tables register a template that contains the l3 family, the name
and a constructor function that is called when the initial table has to
be added.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-08-09 10:22:01 +02:00
Jozsef Kadlecsik 5f7b51bf09 netfilter: ipset: Limit the maximal range of consecutive elements to add/delete
The range size of consecutive elements were not limited. Thus one could
define a huge range which may result soft lockup errors due to the long
execution time. Now the range size is limited to 2^20 entries.

Reported-by: Brad Spengler <spender@grsecurity.net>
Signed-off-by: Jozsef Kadlecsik <kadlec@netfilter.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-08-04 10:41:03 +02:00
Pablo Neira Ayuso ef4b65e53c netfilter: nfnetlink: add struct nfgenmsg to struct nfnl_info and use it
Update the nfnl_info structure to add a pointer to the nfnetlink header.
This simplifies the existing codebase since this header is usually
accessed. Update existing clients to use this new field.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-06-07 12:23:36 +02:00
Florian Westphal 586d5a8bce netfilter: x_tables: reduce xt_action_param by 8 byte
The fragment offset in ipv4/ipv6 is a 16bit field, so use
u16 instead of unsigned int.

On 64bit: 40 bytes to 32 bytes. By extension this also reduces
nft_pktinfo (56 to 48 byte).

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-05-29 01:04:53 +02:00
Florian Westphal 47a6959fa3 netfilter: allow to turn off xtables compat layer
The compat layer needs to parse untrusted input (the ruleset)
to translate it to a 64bit compatible format.

We had a number of bugs in this department in the past, so allow users
to turn this feature off.

Add CONFIG_NETFILTER_XTABLES_COMPAT kconfig knob and make it default to y
to keep existing behaviour.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-04-26 18:16:56 +02:00
Pablo Neira Ayuso 50f2db9e36 netfilter: nfnetlink: consolidate callback types
Add enum nfnl_callback_type to identify the callback type to provide one
single callback.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-04-26 18:16:56 +02:00
Pablo Neira Ayuso 7dab8ee3b6 netfilter: nfnetlink: pass struct nfnl_info to batch callbacks
Update batch callbacks to use the nfnl_info structure. Rename one
clashing info variable to expr_info.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-04-26 18:16:56 +02:00
Pablo Neira Ayuso 797d49805d netfilter: nfnetlink: pass struct nfnl_info to rcu callbacks
Update rcu callbacks to use the nfnl_info structure.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-04-26 18:16:52 +02:00
Pablo Neira Ayuso a655536571 netfilter: nfnetlink: add struct nfnl_info and pass it to callbacks
Add a new structure to reduce callback footprint and to facilite
extensions of the nfnetlink callback interface in the future.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-04-26 03:58:17 +02:00
Florian Westphal ae68933422 netfilter: ip_tables: pass table pointer via nf_hook_ops
iptable_x modules rely on 'struct net' to contain a pointer to the
table that should be evaluated.

In order to remove these pointers from struct net, pass them via
the 'priv' pointer in a similar fashion as nf_tables passes the
rule data.

To do that, duplicate the nf_hook_info array passed in from the
iptable_x modules, update the ops->priv pointers of the copy to
refer to the table and then change the hookfn implementations to
just pass the 'priv' argument to the traverser.

After this patch, the xt_table pointers can already be removed
from struct net.

However, changes to struct net result in re-compile of the entire
network stack, so do the removal after arptables and ip6tables
have been converted as well.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-04-26 03:20:46 +02:00
Florian Westphal 1ef4d6d1af netfilter: x_tables: add xt_find_table
This will be used to obtain the xt_table struct given address family and
table name.

Followup patches will reduce the number of direct accesses to the xt_table
structures via net->ipv{4,6}.ip(6)table_{nat,mangle,...} pointers, then
remove them.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-04-26 03:20:39 +02:00
Florian Westphal 237c609f87 netfilter: nfnetlink: add and use nfnetlink_broadcast
This removes the only reference of net->nfnl outside of the nfnetlink
module.  This allows to move net->nfnl to net_generic infra.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-04-06 00:34:51 +02:00
Pablo Neira Ayuso 19c28b1374 netfilter: add helper function to set up the nfnetlink header and use it
This patch adds a helper function to set up the netlink and nfnetlink headers.
Update existing codebase to use it.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-03-31 22:34:11 +02:00
Wan Jiabing 5c701e7196 netfilter: ipset: Remove duplicate declaration
struct ip_set is declared twice. One is declared at 79th line,
so remove the duplicate.

Signed-off-by: Wan Jiabing <wanjiabing@vivo.com>
Acked-by: Jozsef Kadlecsik <kadlec@netfilter.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-03-31 22:34:11 +02:00
Mark Tomlinson 175e476b8c netfilter: x_tables: Use correct memory barriers.
When a new table value was assigned, it was followed by a write memory
barrier. This ensured that all writes before this point would complete
before any writes after this point. However, to determine whether the
rules are unused, the sequence counter is read. To ensure that all
writes have been done before these reads, a full memory barrier is
needed, not just a write memory barrier. The same argument applies when
incrementing the counter, before the rules are read.

Changing to using smp_mb() instead of smp_wmb() fixes the kernel panic
reported in cc00bcaa58 (which is still present), while still
maintaining the same speed of replacing tables.

The smb_mb() barriers potentially slow the packet path, however testing
has shown no measurable change in performance on a 4-core MIPS64
platform.

Fixes: 7f5c6d4f66 ("netfilter: get rid of atomic ops in fast path")
Signed-off-by: Mark Tomlinson <mark.tomlinson@alliedtelesis.co.nz>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-03-15 18:42:01 +01:00
Mark Tomlinson d3d40f2374 Revert "netfilter: x_tables: Switch synchronization to RCU"
This reverts commit cc00bcaa58.

This (and the preceding) patch basically re-implemented the RCU
mechanisms of patch 784544739a. That patch was replaced because of the
performance problems that it created when replacing tables. Now, we have
the same issue: the call to synchronize_rcu() makes replacing tables
slower by as much as an order of magnitude.

Prior to using RCU a script calling "iptables" approx. 200 times was
taking 1.16s. With RCU this increased to 11.59s.

Revert these patches and fix the issue in a different way.

Signed-off-by: Mark Tomlinson <mark.tomlinson@alliedtelesis.co.nz>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-03-15 18:42:01 +01:00
Jakub Kicinski 46d5e62dd3 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
xdp_return_frame_bulk() needs to pass a xdp_buff
to __xdp_return().

strlcpy got converted to strscpy but here it makes no
functional difference, so just keep the right code.

Conflicts:
	net/netfilter/nf_tables_api.c

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-11 22:29:38 -08:00
Subash Abhinov Kasiviswanathan cc00bcaa58 netfilter: x_tables: Switch synchronization to RCU
When running concurrent iptables rules replacement with data, the per CPU
sequence count is checked after the assignment of the new information.
The sequence count is used to synchronize with the packet path without the
use of any explicit locking. If there are any packets in the packet path using
the table information, the sequence count is incremented to an odd value and
is incremented to an even after the packet process completion.

The new table value assignment is followed by a write memory barrier so every
CPU should see the latest value. If the packet path has started with the old
table information, the sequence counter will be odd and the iptables
replacement will wait till the sequence count is even prior to freeing the
old table info.

However, this assumes that the new table information assignment and the memory
barrier is actually executed prior to the counter check in the replacement
thread. If CPU decides to execute the assignment later as there is no user of
the table information prior to the sequence check, the packet path in another
CPU may use the old table information. The replacement thread would then free
the table information under it leading to a use after free in the packet
processing context-

Unable to handle kernel NULL pointer dereference at virtual
address 000000000000008e
pc : ip6t_do_table+0x5d0/0x89c
lr : ip6t_do_table+0x5b8/0x89c
ip6t_do_table+0x5d0/0x89c
ip6table_filter_hook+0x24/0x30
nf_hook_slow+0x84/0x120
ip6_input+0x74/0xe0
ip6_rcv_finish+0x7c/0x128
ipv6_rcv+0xac/0xe4
__netif_receive_skb+0x84/0x17c
process_backlog+0x15c/0x1b8
napi_poll+0x88/0x284
net_rx_action+0xbc/0x23c
__do_softirq+0x20c/0x48c

This could be fixed by forcing instruction order after the new table
information assignment or by switching to RCU for the synchronization.

Fixes: 80055dab5d ("netfilter: x_tables: make xt_replace_table wait until old rules are not used anymore")
Reported-by: Sean Tranchetti <stranche@codeaurora.org>
Reported-by: kernel test robot <lkp@intel.com>
Suggested-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2020-12-08 12:57:39 +01:00
Jakub Kicinski ae0d0bb29b Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-11-06 17:33:38 -08:00
Jozsef Kadlecsik ccf0a4b7fc netfilter: ipset: Add bucketsize parameter to all hash types
The parameter defines the upper limit in any hash bucket at adding new entries
from userspace - if the limit would be exceeded, ipset doubles the hash size
and rehashes. It means the set may consume more memory but gives faster
evaluation at matching in the set.

Signed-off-by: Jozsef Kadlecsik <kadlec@netfilter.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2020-10-31 11:54:42 +01:00
Pablo Neira Ayuso c0391b6ab8 netfilter: nf_tables: missing validation from the abort path
If userspace does not include the trailing end of batch message, then
nfnetlink aborts the transaction. This allows to check that ruleset
updates trigger no errors.

After this patch, invoking this command from the prerouting chain:

 # nft -c add rule x y fib saddr . oif type local

fails since oif is not supported there.

This patch fixes the lack of rule validation from the abort/check path
to catch configuration errors such as the one above.

Fixes: a654de8fdc ("netfilter: nf_tables: fix chain dependency validation")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2020-10-30 12:57:39 +01:00
David S. Miller d85427e3c8 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 net-next:

1) Rewrite inner header IPv6 in ICMPv6 messages in ip6t_NPT,
   from Michael Zhou.

2) do_ip_vs_set_ctl() dereferences uninitialized value,
   from Peilin Ye.

3) Support for userdata in tables, from Jose M. Guisado.

4) Do not increment ct error and invalid stats at the same time,
   from Florian Westphal.

5) Remove ct ignore stats, also from Florian.

6) Add ct stats for clash resolution, from Florian Westphal.

7) Bump reference counter bump on ct clash resolution only,
   this is safe because bucket lock is held, again from Florian.

8) Use ip_is_fragment() in xt_HMARK, from YueHaibing.

9) Add wildcard support for nft_socket, from Balazs Scheidler.

10) Remove superfluous IPVS dependency on iptables, from
    Yaroslav Bolyukin.

11) Remove unused definition in ebt_stp, from Wang Hai.

12) Replace CONFIG_NFT_CHAIN_NAT_{IPV4,IPV6} by CONFIG_NFT_NAT
    in selftests/net, from Fabian Frederick.

13) Add userdata support for nft_object, from Jose M. Guisado.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-09 11:21:19 -07:00
Pablo Neira Ayuso ee92118355 netfilter: nfnetlink: nfnetlink_unicast() reports EAGAIN instead of ENOBUFS
Frontend callback reports EAGAIN to nfnetlink to retry a command, this
is used to signal that module autoloading is required. Unfortunately,
nlmsg_unicast() reports EAGAIN in case the receiver socket buffer gets
full, so it enters a busy-loop.

This patch updates nfnetlink_unicast() to turn EAGAIN into ENOBUFS and
to use nlmsg_unicast(). Remove the flags field in nfnetlink_unicast()
since this is always MSG_DONTWAIT in the existing code which is exactly
what nlmsg_unicast() passes to netlink_unicast() as parameter.

Fixes: 96518518cc ("netfilter: add nftables")
Reported-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2020-08-28 20:11:58 +02:00
Florian Westphal bc92470413 netfilter: conntrack: add clash resolution stat counter
There is a misconception about what "insert_failed" means.

We increment this even when a clash got resolved, so it might not indicate
a problem.

Add a dedicated counter for clash resolution and only increment
insert_failed if a clash cannot be resolved.

For the old /proc interface, export this in place of an older stat
that got removed a while back.
For ctnetlink, export this with a new attribute.

Also correct an outdated comment that implies we add a duplicate tuple --
we only add the (unique) reply direction.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2020-08-28 19:51:26 +02:00
Florian Westphal 4afc41dfa5 netfilter: conntrack: remove ignore stats
This counter increments when nf_conntrack_in sees a packet that already
has a conntrack attached or when the packet is marked as UNTRACKED.
Neither is an error.

The former is normal for loopback traffic.  The second happens for
certain ICMPv6 packets or when nftables/ip(6)tables rules are in place.

In case someone needs to count UNTRACKED packets, or packets
that are marked as untracked before conntrack_in this can be done with
both nftables and ip(6)tables rules.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2020-08-28 19:51:26 +02:00
Florian Westphal cc5453a5b7 netfilter: conntrack: allow sctp hearbeat after connection re-use
If an sctp connection gets re-used, heartbeats are flagged as invalid
because their vtag doesn't match.

Handle this in a similar way as TCP conntrack when it suspects that the
endpoints and conntrack are out-of-sync.

When a HEARTBEAT request fails its vtag validation, flag this in the
conntrack state and accept the packet.

When a HEARTBEAT_ACK is received with an invalid vtag in the reverse
direction after we allowed such a HEARTBEAT through, assume we are
out-of-sync and re-set the vtag info.

v2: remove left-over snippet from an older incarnation that moved
    new_state/old_state assignments, thats not needed so keep that
    as-is.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2020-08-20 14:13:49 +02:00
Christoph Hellwig ab214d1bf8 netfilter: switch xt_copy_counters to sockptr_t
Pass a sockptr_t to prepare for set_fs-less handling of the kernel
pointer from bpf-cgroup.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-24 15:41:53 -07:00
Christoph Hellwig c34bc10d25 netfilter: remove the compat argument to xt_copy_counters_from_user
Lift the in_compat_syscall() from the callers instead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19 18:16:40 -07:00
Pablo Neira Ayuso 4946ea5c12 netfilter: nf_conntrack_pptp: fix compilation warning with W=1 build
>> include/linux/netfilter/nf_conntrack_pptp.h:13:20: warning: 'const' type qualifier on return type has no effect [-Wignored-qualifiers]
extern const char *const pptp_msg_name(u_int16_t msg);
^~~~~~

Reported-by: kbuild test robot <lkp@intel.com>
Fixes: 4c559f15ef ("netfilter: nf_conntrack_pptp: prevent buffer overflows in debug code")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2020-05-27 13:39:08 +02:00
Pablo Neira Ayuso 4c559f15ef netfilter: nf_conntrack_pptp: prevent buffer overflows in debug code
Dan Carpenter says: "Smatch complains that the value for "cmd" comes
from the network and can't be trusted."

Add pptp_msg_name() helper function that checks for the array boundary.

Fixes: f09943fefe ("[NETFILTER]: nf_conntrack/nf_nat: add PPTP helper port")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2020-05-25 20:39:14 +02:00
Gustavo A. R. Silva 6daf141401 netfilter: Replace zero-length array with flexible-array member
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

Lastly, fix checkpatch.pl warning
WARNING: __aligned(size) is preferred over __attribute__((aligned(size)))
in net/bridge/netfilter/ebtables.c

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2020-03-15 15:20:16 +01:00
Jozsef Kadlecsik f66ee0410b netfilter: ipset: Fix "INFO: rcu detected stall in hash_xxx" reports
In the case of huge hash:* types of sets, due to the single spinlock of
a set the processing of the whole set under spinlock protection could take
too long.

There were four places where the whole hash table of the set was processed
from bucket to bucket under holding the spinlock:

- During resizing a set, the original set was locked to exclude kernel side
  add/del element operations (userspace add/del is excluded by the
  nfnetlink mutex). The original set is actually just read during the
  resize, so the spinlocking is replaced with rcu locking of regions.
  However, thus there can be parallel kernel side add/del of entries.
  In order not to loose those operations a backlog is added and replayed
  after the successful resize.
- Garbage collection of timed out entries was also protected by the spinlock.
  In order not to lock too long, region locking is introduced and a single
  region is processed in one gc go. Also, the simple timer based gc running
  is replaced with a workqueue based solution. The internal book-keeping
  (number of elements, size of extensions) is moved to region level due to
  the region locking.
- Adding elements: when the max number of the elements is reached, the gc
  was called to evict the timed out entries. The new approach is that the gc
  is called just for the matching region, assuming that if the region
  (proportionally) seems to be full, then the whole set does. We could scan
  the other regions to check every entry under rcu locking, but for huge
  sets it'd mean a slowdown at adding elements.
- Listing the set header data: when the set was defined with timeout
  support, the garbage collector was called to clean up timed out entries
  to get the correct element numbers and set size values. Now the set is
  scanned to check non-timed out entries, without actually calling the gc
  for the whole set.

Thanks to Florian Westphal for helping me to solve the SOFTIRQ-safe ->
SOFTIRQ-unsafe lock order issues during working on the patch.

Reported-by: syzbot+4b0e9d4ff3cf117837e5@syzkaller.appspotmail.com
Reported-by: syzbot+c27b8d5010f45c666ed1@syzkaller.appspotmail.com
Reported-by: syzbot+68a806795ac89df3aa1c@syzkaller.appspotmail.com
Fixes: 23c42a403a ("netfilter: ipset: Introduction of new commands and protocol version 7")
Signed-off-by: Jozsef Kadlecsik <kadlec@netfilter.org>
2020-02-22 12:00:06 +01:00
Pablo Neira Ayuso eb014de4fd netfilter: nf_tables: autoload modules from the abort path
This patch introduces a list of pending module requests. This new module
list is composed of nft_module_request objects that contain the module
name and one status field that tells if the module has been already
loaded (the 'done' field).

In the first pass, from the preparation phase, the netlink command finds
that a module is missing on this list. Then, a module request is
allocated and added to this list and nft_request_module() returns
-EAGAIN. This triggers the abort path with the autoload parameter set on
from nfnetlink, request_module() is called and the module request enters
the 'done' state. Since the mutex is released when loading modules from
the abort phase, the module list is zapped so this is iteration occurs
over a local list. Therefore, the request_module() calls happen when
object lists are in consistent state (after fulling aborting the
transaction) and the commit list is empty.

On the second pass, the netlink command will find that it already tried
to load the module, so it does not request it again and
nft_request_module() returns 0. Then, there is a look up to find the
object that the command was missing. If the module was successfully
loaded, the command proceeds normally since it finds the missing object
in place, otherwise -ENOENT is reported to userspace.

This patch also updates nfnetlink to include the reason to enter the
abort phase, which is required for this new autoload module rationale.

Fixes: ec7470b834 ("netfilter: nf_tables: store transaction list locally while requesting module")
Reported-by: syzbot+29125d208b3dae9a7019@syzkaller.appspotmail.com
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2020-01-24 20:54:29 +01:00
Kadlecsik József 32c72165db netfilter: ipset: use bitmap infrastructure completely
The bitmap allocation did not use full unsigned long sizes
when calculating the required size and that was triggered by KASAN
as slab-out-of-bounds read in several places. The patch fixes all
of them.

Reported-by: syzbot+fabca5cbf5e54f3fe2de@syzkaller.appspotmail.com
Reported-by: syzbot+827ced406c9a1d9570ed@syzkaller.appspotmail.com
Reported-by: syzbot+190d63957b22ef673ea5@syzkaller.appspotmail.com
Reported-by: syzbot+dfccdb2bdb4a12ad425e@syzkaller.appspotmail.com
Reported-by: syzbot+df0d0f5895ef1f41a65b@syzkaller.appspotmail.com
Reported-by: syzbot+b08bd19bb37513357fd4@syzkaller.appspotmail.com
Reported-by: syzbot+53cdd0ec0bbabd53370a@syzkaller.appspotmail.com
Signed-off-by: Jozsef Kadlecsik <kadlec@netfilter.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2020-01-20 17:41:45 +01:00
Jeremy Sowden f8615bf8a3 netfilter: ipset: move ip_set_get_ip_port() to ip_set_bitmap_port.c.
ip_set_get_ip_port() is only used in ip_set_bitmap_port.c.  Move it
there and make it static.

Signed-off-by: Jeremy Sowden <jeremy@azazel.net>
Acked-by: Jozsef Kadlecsik <kadlec@netfilter.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-10-07 23:59:02 +02:00
Jeremy Sowden 3fbd6c4513 netfilter: ipset: move function to ip_set_bitmap_ip.c.
One inline function in ip_set_bitmap.h is only called in
ip_set_bitmap_ip.c: move it and remove inline function specifier.

Signed-off-by: Jeremy Sowden <jeremy@azazel.net>
Acked-by: Jozsef Kadlecsik <kadlec@netfilter.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-10-07 23:58:35 +02:00
Jeremy Sowden 856391854c netfilter: ipset: make ip_set_put_flags extern.
ip_set_put_flags is rather large for a static inline function in a
header-file.  Move it to ip_set_core.c and export it.

Signed-off-by: Jeremy Sowden <jeremy@azazel.net>
Acked-by: Jozsef Kadlecsik <kadlec@netfilter.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-10-07 23:58:24 +02:00
Jeremy Sowden 2398a97688 netfilter: ipset: move functions to ip_set_core.c.
Several inline functions in ip_set.h are only called in ip_set_core.c:
move them and remove inline function specifier.

Signed-off-by: Jeremy Sowden <jeremy@azazel.net>
Acked-by: Jozsef Kadlecsik <kadlec@netfilter.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-10-07 23:58:10 +02:00
Jeremy Sowden 94177f6e11 netfilter: ipset: move ip_set_comment functions from ip_set.h to ip_set_core.c.
Most of the functions are only called from within ip_set_core.c.

The exception is ip_set_init_comment.  However, this is too complex to
be a good candidate for a static inline function.  Move it to
ip_set_core.c, change its linkage to extern and export it, leaving a
declaration in ip_set.h.

ip_set_comment_free is only used as an extension destructor, so change
its prototype to match and drop cast.

Signed-off-by: Jeremy Sowden <jeremy@azazel.net>
Acked-by: Jozsef Kadlecsik <kadlec@netfilter.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-10-07 23:57:56 +02:00
Jeremy Sowden 017f77c050 netfilter: ipset: add a coding-style fix to ip_set_ext_destroy.
Use a local variable to hold comment in order to align the arguments of
ip_set_comment_free properly.

Signed-off-by: Jeremy Sowden <jeremy@azazel.net>
Acked-by: Jozsef Kadlecsik <kadlec@netfilter.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-10-07 23:57:30 +02:00
Jeremy Sowden f19438bdd4 netfilter: remove CONFIG_NETFILTER checks from headers.
`struct nf_hook_ops`, `struct nf_hook_state` and the `nf_hookfn`
function typedef appear in function and struct declarations and
definitions in a number of netfilter headers.  The structs and typedef
themselves are defined by linux/netfilter.h but only when
CONFIG_NETFILTER is enabled.  Define them unconditionally and add
forward declarations in order to remove CONFIG_NETFILTER conditionals
from the other headers.

Signed-off-by: Jeremy Sowden <jeremy@azazel.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-09-13 12:47:36 +02:00
Jeremy Sowden 261db6c2fb netfilter: conntrack: move code to linux/nf_conntrack_common.h.
Move some `struct nf_conntrack` code from linux/skbuff.h to
linux/nf_conntrack_common.h.  Together with a couple of helpers for
getting and setting skb->_nfct, it allows us to remove
CONFIG_NF_CONNTRACK checks from net/netfilter/nf_conntrack.h.

Signed-off-by: Jeremy Sowden <jeremy@azazel.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-09-13 12:47:11 +02:00
Jeremy Sowden 25d7cbcd2b netfilter: replace defined(CONFIG...) || defined(CONFIG...MODULE) with IS_ENABLED(CONFIG...).
A few headers contain instances of:

  #if defined(CONFIG_XXX) or defined(CONFIG_XXX_MODULE)

Replace them with:

  #if IS_ENABLED(CONFIG_XXX)

Signed-off-by: Jeremy Sowden <jeremy@azazel.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-09-13 12:47:09 +02:00
Jeremy Sowden 85cfbc25e5 netfilter: inline xt_hashlimit, ebt_802_3 and xt_physdev headers
Three netfilter headers are only included once.  Inline their contents
at those sites and remove them.

Signed-off-by: Jeremy Sowden <jeremy@azazel.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-09-13 12:32:48 +02:00