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path: root/net/netfilter/nft_set_bitmap.c
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2023-10-24netfilter: nf_tables: set->ops->insert returns opaque set element in case of ↵Pablo Neira Ayuso1-2/+2
EEXIST Return struct nft_elem_priv instead of struct nft_set_ext for consistency with ("netfilter: nf_tables: expose opaque set element as struct nft_elem_priv") and to prepare the introduction of element timeout updates from control path. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2023-10-24netfilter: nf_tables: shrink memory consumption of set elementsPablo Neira Ayuso1-10/+6
Instead of copying struct nft_set_elem into struct nft_trans_elem, store the pointer to the opaque set element object in the transaction. Adapt set backend API (and set backend implementations) to take the pointer to opaque set element representation whenever required. This patch deconstifies .remove() and .activate() set backend API since these modify the set element opaque object. And it also constify nft_set_elem_ext() this provides access to the nft_set_ext struct without updating the object. According to pahole on x86_64, this patch shrinks struct nft_trans_elem size from 216 to 24 bytes. This patch also reduces stack memory consumption by removing the template struct nft_set_elem object, using the opaque set element object instead such as from the set iterator API, catchall elements and the get element command. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2023-10-24netfilter: nf_tables: expose opaque set element as struct nft_elem_privPablo Neira Ayuso1-15/+20
Add placeholder structure and place it at the beginning of each struct nft_*_elem for each existing set backend, instead of exposing elements as void type to the frontend which defeats compiler type checks. Use this pointer to this new type to replace void *. This patch updates the following set backend API to use this new struct nft_elem_priv placeholder structure: - update - deactivate - flush - get as well as the following helper functions: - nft_set_elem_ext() - nft_set_elem_init() - nft_set_elem_destroy() - nf_tables_set_elem_destroy() This patch adds nft_elem_priv_cast() to cast struct nft_elem_priv to native element representation from the corresponding set backend. BUILD_BUG_ON() makes sure this .priv placeholder is always at the top of the opaque set element representation. Suggested-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2023-10-24netfilter: nf_tables: set backend .flush always succeedsPablo Neira Ayuso1-3/+1
.flush is always successful since this results from iterating over the set elements to toggle mark the element as inactive in the next generation. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2023-06-20netfilter: nf_tables: drop map element references from preparation phasePablo Neira Ayuso1-2/+3
set .destroy callback releases the references to other objects in maps. This is very late and it results in spurious EBUSY errors. Drop refcount from the preparation phase instead, update set backend not to drop reference counter from set .destroy path. Exceptions: NFT_TRANS_PREPARE_ERROR does not require to drop the reference counter because the transaction abort path releases the map references for each element since the set is unbound. The abort path also deals with releasing reference counter for new elements added to unbound sets. Fixes: 591054469b3e ("netfilter: nf_tables: revisit chain/object refcounting from elements") Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2022-07-11netfilter: nft_set_bitmap: Fix spelling mistakeZhang Jiaming1-2/+2
Change 'succesful' to 'successful'. Change 'transation' to 'transaction'. Signed-off-by: Zhang Jiaming <jiaming@nfschina.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-05-29netfilter: nf_tables: prefer direct calls for set lookupsFlorian Westphal1-2/+3
Extend nft_set_do_lookup() to use direct calls when retpoline feature is enabled. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2020-04-06netfilter: nf_tables: do not update stateful expressions if lookup is invertedPablo Neira Ayuso1-1/+0
Initialize set lookup matching element to NULL. Otherwise, the NFT_LOOKUP_F_INV flag reverses the matching logic and it leads to deference an uninitialized pointer to the matching element. Make sure element data area and stateful expression are accessed if there is a matching set element. This patch undoes 24791b9aa1ab ("netfilter: nft_set_bitmap: initialize set element extension in lookups") which is not required anymore. Fixes: 339706bc21c1 ("netfilter: nft_lookup: update element stateful expression") Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2020-03-30netfilter: nf_tables: skip set types that do not support for expressionsPablo Neira Ayuso1-0/+2
The bitmap set does not support for expressions, skip it from the estimation step. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2020-03-30netfilter: nft_set_bitmap: initialize set element extension in lookupsPablo Neira Ayuso1-0/+1
Otherwise, nft_lookup might dereference an uninitialized pointer to the element extension. Fixes: 665153ff5752 ("netfilter: nf_tables: add bitmap set type") Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2020-03-15netfilter: nf_tables: make all set structs constFlorian Westphal1-2/+1
They do not need to be writeable anymore. v2: remove left-over __read_mostly annotation in set_pipapo.c (Stefano) Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2020-01-16netfilter: nf_tables: white-space fixes.Jeremy Sowden1-2/+2
Indentation fixes for the parameters of a few nft functions. Signed-off-by: Jeremy Sowden <jeremy@azazel.net> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-08-13netfilter: nf_tables: add missing prototypes.Valdis Klētnieks1-1/+1
Sparse rightly complains about undeclared symbols. CHECK net/netfilter/nft_set_hash.c net/netfilter/nft_set_hash.c:647:21: warning: symbol 'nft_set_rhash_type' was not declared. Should it be static? net/netfilter/nft_set_hash.c:670:21: warning: symbol 'nft_set_hash_type' was not declared. Should it be static? net/netfilter/nft_set_hash.c:690:21: warning: symbol 'nft_set_hash_fast_type' was not declared. Should it be static? CHECK net/netfilter/nft_set_bitmap.c net/netfilter/nft_set_bitmap.c:296:21: warning: symbol 'nft_set_bitmap_type' was not declared. Should it be static? CHECK net/netfilter/nft_set_rbtree.c net/netfilter/nft_set_rbtree.c:470:21: warning: symbol 'nft_set_rbtree_type' was not declared. Should it be static? Include nf_tables_core.h rather than nf_tables.h to pick up the additional definitions. Signed-off-by: Valdis Kletnieks <valdis.kletnieks@vt.edu> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-06-19treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500Thomas Gleixner1-4/+1
Based on 2 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation # extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 4122 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Enrico Weigelt <info@metux.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-08-16netfilter: nft_set: fix allocation size overflow in privsize callback.Taehee Yoo1-3/+3
In order to determine allocation size of set, ->privsize is invoked. At this point, both desc->size and size of each data structure of set are used. desc->size means number of element that is given by user. desc->size is u32 type. so that upperlimit of set element is 4294967295. but return type of ->privsize is also u32. hence overflow can occurred. test commands: %nft add table ip filter %nft add set ip filter hash1 { type ipv4_addr \; size 4294967295 \; } %nft list ruleset splat looks like: [ 1239.202910] kasan: CONFIG_KASAN_INLINE enabled [ 1239.208788] kasan: GPF could be caused by NULL-ptr deref or user memory access [ 1239.217625] general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI [ 1239.219329] CPU: 0 PID: 1603 Comm: nft Not tainted 4.18.0-rc5+ #7 [ 1239.229091] RIP: 0010:nft_hash_walk+0x1d2/0x310 [nf_tables_set] [ 1239.229091] Code: 84 d2 7f 10 4c 89 e7 89 44 24 38 e8 d8 5a 17 e0 8b 44 24 38 48 8d 7b 10 41 0f b6 0c 24 48 89 fa 48 89 fe 48 c1 ea 03 83 e6 07 <42> 0f b6 14 3a 40 38 f2 7f 1a 84 d2 74 16 [ 1239.229091] RSP: 0018:ffff8801118cf358 EFLAGS: 00010246 [ 1239.229091] RAX: 0000000000000000 RBX: 0000000000020400 RCX: 0000000000000001 [ 1239.229091] RDX: 0000000000004082 RSI: 0000000000000000 RDI: 0000000000020410 [ 1239.229091] RBP: ffff880114d5a988 R08: 0000000000007e94 R09: ffff880114dd8030 [ 1239.229091] R10: ffff880114d5a988 R11: ffffed00229bb006 R12: ffff8801118cf4d0 [ 1239.229091] R13: ffff8801118cf4d8 R14: 0000000000000000 R15: dffffc0000000000 [ 1239.229091] FS: 00007f5a8fe0b700(0000) GS:ffff88011b600000(0000) knlGS:0000000000000000 [ 1239.229091] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 1239.229091] CR2: 00007f5a8ecc27b0 CR3: 000000010608e000 CR4: 00000000001006f0 [ 1239.229091] Call Trace: [ 1239.229091] ? nft_hash_remove+0xf0/0xf0 [nf_tables_set] [ 1239.229091] ? memset+0x1f/0x40 [ 1239.229091] ? __nla_reserve+0x9f/0xb0 [ 1239.229091] ? memcpy+0x34/0x50 [ 1239.229091] nf_tables_dump_set+0x9a1/0xda0 [nf_tables] [ 1239.229091] ? __kmalloc_reserve.isra.29+0x2e/0xa0 [ 1239.229091] ? nft_chain_hash_obj+0x630/0x630 [nf_tables] [ 1239.229091] ? nf_tables_commit+0x2c60/0x2c60 [nf_tables] [ 1239.229091] netlink_dump+0x470/0xa20 [ 1239.229091] __netlink_dump_start+0x5ae/0x690 [ 1239.229091] nft_netlink_dump_start_rcu+0xd1/0x160 [nf_tables] [ 1239.229091] nf_tables_getsetelem+0x2e5/0x4b0 [nf_tables] [ 1239.229091] ? nft_get_set_elem+0x440/0x440 [nf_tables] [ 1239.229091] ? nft_chain_hash_obj+0x630/0x630 [nf_tables] [ 1239.229091] ? nf_tables_dump_obj_done+0x70/0x70 [nf_tables] [ 1239.229091] ? nla_parse+0xab/0x230 [ 1239.229091] ? nft_get_set_elem+0x440/0x440 [nf_tables] [ 1239.229091] nfnetlink_rcv_msg+0x7f0/0xab0 [nfnetlink] [ 1239.229091] ? nfnetlink_bind+0x1d0/0x1d0 [nfnetlink] [ 1239.229091] ? debug_show_all_locks+0x290/0x290 [ 1239.229091] ? sched_clock_cpu+0x132/0x170 [ 1239.229091] ? find_held_lock+0x39/0x1b0 [ 1239.229091] ? sched_clock_local+0x10d/0x130 [ 1239.229091] netlink_rcv_skb+0x211/0x320 [ 1239.229091] ? nfnetlink_bind+0x1d0/0x1d0 [nfnetlink] [ 1239.229091] ? netlink_ack+0x7b0/0x7b0 [ 1239.229091] ? ns_capable_common+0x6e/0x110 [ 1239.229091] nfnetlink_rcv+0x2d1/0x310 [nfnetlink] [ 1239.229091] ? nfnetlink_rcv_batch+0x10f0/0x10f0 [nfnetlink] [ 1239.229091] ? netlink_deliver_tap+0x829/0x930 [ 1239.229091] ? lock_acquire+0x265/0x2e0 [ 1239.229091] netlink_unicast+0x406/0x520 [ 1239.509725] ? netlink_attachskb+0x5b0/0x5b0 [ 1239.509725] ? find_held_lock+0x39/0x1b0 [ 1239.509725] netlink_sendmsg+0x987/0xa20 [ 1239.509725] ? netlink_unicast+0x520/0x520 [ 1239.509725] ? _copy_from_user+0xa9/0xc0 [ 1239.509725] __sys_sendto+0x21a/0x2c0 [ 1239.509725] ? __ia32_sys_getpeername+0xa0/0xa0 [ 1239.509725] ? retint_kernel+0x10/0x10 [ 1239.509725] ? sched_clock_cpu+0x132/0x170 [ 1239.509725] ? find_held_lock+0x39/0x1b0 [ 1239.509725] ? lock_downgrade+0x540/0x540 [ 1239.509725] ? up_read+0x1c/0x100 [ 1239.509725] ? __do_page_fault+0x763/0x970 [ 1239.509725] ? retint_user+0x18/0x18 [ 1239.509725] __x64_sys_sendto+0x177/0x180 [ 1239.509725] do_syscall_64+0xaa/0x360 [ 1239.509725] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 1239.509725] RIP: 0033:0x7f5a8f468e03 [ 1239.509725] Code: 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb d0 0f 1f 84 00 00 00 00 00 83 3d 49 c9 2b 00 00 75 13 49 89 ca b8 2c 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 34 c3 48 83 ec 08 e8 [ 1239.509725] RSP: 002b:00007ffd78d0b778 EFLAGS: 00000246 ORIG_RAX: 000000000000002c [ 1239.509725] RAX: ffffffffffffffda RBX: 00007ffd78d0c890 RCX: 00007f5a8f468e03 [ 1239.509725] RDX: 0000000000000034 RSI: 00007ffd78d0b7e0 RDI: 0000000000000003 [ 1239.509725] RBP: 00007ffd78d0b7d0 R08: 00007f5a8f15c160 R09: 000000000000000c [ 1239.509725] R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd78d0b7e0 [ 1239.509725] R13: 0000000000000034 R14: 00007f5a8f9aff60 R15: 00005648040094b0 [ 1239.509725] Modules linked in: nf_tables_set nf_tables nfnetlink ip_tables x_tables [ 1239.670713] ---[ end trace 39375adcda140f11 ]--- [ 1239.676016] RIP: 0010:nft_hash_walk+0x1d2/0x310 [nf_tables_set] [ 1239.682834] Code: 84 d2 7f 10 4c 89 e7 89 44 24 38 e8 d8 5a 17 e0 8b 44 24 38 48 8d 7b 10 41 0f b6 0c 24 48 89 fa 48 89 fe 48 c1 ea 03 83 e6 07 <42> 0f b6 14 3a 40 38 f2 7f 1a 84 d2 74 16 [ 1239.705108] RSP: 0018:ffff8801118cf358 EFLAGS: 00010246 [ 1239.711115] RAX: 0000000000000000 RBX: 0000000000020400 RCX: 0000000000000001 [ 1239.719269] RDX: 0000000000004082 RSI: 0000000000000000 RDI: 0000000000020410 [ 1239.727401] RBP: ffff880114d5a988 R08: 0000000000007e94 R09: ffff880114dd8030 [ 1239.735530] R10: ffff880114d5a988 R11: ffffed00229bb006 R12: ffff8801118cf4d0 [ 1239.743658] R13: ffff8801118cf4d8 R14: 0000000000000000 R15: dffffc0000000000 [ 1239.751785] FS: 00007f5a8fe0b700(0000) GS:ffff88011b600000(0000) knlGS:0000000000000000 [ 1239.760993] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 1239.767560] CR2: 00007f5a8ecc27b0 CR3: 000000010608e000 CR4: 00000000001006f0 [ 1239.775679] Kernel panic - not syncing: Fatal exception [ 1239.776630] Kernel Offset: 0x1f000000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff) [ 1239.776630] Rebooting in 5 seconds.. Fixes: 20a69341f2d0 ("netfilter: nf_tables: add netlink set API") Signed-off-by: Taehee Yoo <ap420073@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-07-06netfilter: nf_tables: place all set backends in one single modulePablo Neira Ayuso1-18/+1
This patch disallows rbtree with single elements, which is causing problems with the recent timeout support. Before this patch, you could opt out individual set representations per module, which is just adding extra complexity. Fixes: 8d8540c4f5e0("netfilter: nft_set_rbtree: add timeout support") Reported-by: Taehee Yoo <ap420073@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-04-24netfilter: nf_tables: Simplify set backend selectionPhil Sutter1-19/+15
Drop nft_set_type's ability to act as a container of multiple backend implementations it chooses from. Instead consolidate the whole selection logic in nft_select_set_ops() and the actual backend provided estimate() callback. This turns nf_tables_set_types into a list containing all available backends which is traversed when selecting one matching userspace requested criteria. Also, this change allows to embed nft_set_ops structure into nft_set_type and pull flags field into the latter as it's only used during selection phase. A crucial part of this change is to make sure the new layout respects hash backend constraints formerly enforced by nft_hash_select_ops() function: This is achieved by introduction of a specific estimate() callback for nft_hash_fast_ops which returns false for key lengths != 4. In turn, nft_hash_estimate() is changed to return false for key lengths == 4 so it won't be chosen by accident. Also, both callbacks must return false for unbounded sets as their size estimate depends on a known maximum element count. Note that this patch partially reverts commit 4f2921ca21b71 ("netfilter: nf_tables: meter: pick a set backend that supports updates") by making nft_set_ops_candidate() not explicitly look for an update callback but make NFT_SET_EVAL a regular backend feature flag which is checked along with the others. This way all feature requirements are checked in one go. Signed-off-by: Phil Sutter <phil@nwl.cc> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-11-07netfilter: nf_tables: get set elements via netlinkPablo Neira Ayuso1-0/+18
This patch adds a new get operation to look up for specific elements in a set via netlink interface. You can also use it to check if an interval already exists. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-05-29netfilter: nf_tables: pass set description to ->privsizePablo Neira Ayuso1-1/+2
The new non-resizable hashtable variant needs this to calculate the size of the bucket array. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-05-29netfilter: nf_tables: select set backend flavour depending on descriptionPablo Neira Ayuso1-2/+8
This patch adds the infrastructure to support several implementations of the same set type. This selection will be based on the set description and the features available for this set. This allow us to select set backend implementation that will result in better performance numbers. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-04-24netfilter: nft_set_bitmap: free dummy elements when destroy the setLiping Zhang1-0/+5
We forget to free dummy elements when deleting the set. So when I was running nft-test.py, I saw many kmemleak warnings: kmemleak: 1344 new suspected memory leaks ... # cat /sys/kernel/debug/kmemleak unreferenced object 0xffff8800631345c8 (size 32): comm "nft", pid 9075, jiffies 4295743309 (age 1354.815s) hex dump (first 32 bytes): f8 63 13 63 00 88 ff ff 88 79 13 63 00 88 ff ff .c.c.....y.c.... 04 0c 00 00 00 00 00 00 00 00 00 00 08 03 00 00 ................ backtrace: [<ffffffff819059da>] kmemleak_alloc+0x4a/0xa0 [<ffffffff81288174>] __kmalloc+0x164/0x310 [<ffffffffa061269d>] nft_set_elem_init+0x3d/0x1b0 [nf_tables] [<ffffffffa06130da>] nft_add_set_elem+0x45a/0x8c0 [nf_tables] [<ffffffffa0613645>] nf_tables_newsetelem+0x105/0x1d0 [nf_tables] [<ffffffffa05fe6d4>] nfnetlink_rcv+0x414/0x770 [nfnetlink] [<ffffffff817f0ca6>] netlink_unicast+0x1f6/0x310 [<ffffffff817f10c6>] netlink_sendmsg+0x306/0x3b0 ... Fixes: e920dde516088 ("netfilter: nft_set_bitmap: keep a list of dummy elements") Signed-off-by: Liping Zhang <zlpnobody@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-03-13netfilter: nft_set_bitmap: keep a list of dummy elementsPablo Neira Ayuso1-80/+66
Element comments may come without any prior set flag, so we have to keep a list of dummy struct nft_set_ext to keep this information around. This is only useful for set dumps to userspace. From the packet path, this set type relies on the bitmap representation. This patch simplifies the logic since we don't need to allocate the dummy nft_set_ext structure anymore on the fly at the cost of increasing memory consumption because of the list of dummy struct nft_set_ext. Fixes: 665153ff5752 ("netfilter: nf_tables: add bitmap set type") Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-03-13netfilter: nft_set_bitmap: fetch the element key based on the set->klenLiping Zhang1-10/+17
Currently we just assume the element key as a u32 integer, regardless of the set key length. This is incorrect, for example, the tcp port number is only 16 bits. So when we use the nft_payload expr to get the tcp dport and store it to dreg, the dport will be stored at 0~15 bits, and 16~31 bits will be padded with zero. So the reg->data[dreg] will be looked like as below: 0 15 31 +-+-+-+-+-+-+-+-+-+-+-+-+ | tcp dport | 0 | +-+-+-+-+-+-+-+-+-+-+-+-+ But for these big-endian systems, if we treate this register as a u32 integer, the element key will be larger than 65535, so the following lookup in bitmap set will cause out of bound access. Another issue is that if we add element with comments in bitmap set(although the comments will be ignored eventually), the element will vanish strangely. Because we treate the element key as a u32 integer, so the comments will become the part of the element key, then the element key will also be larger than 65535 and out of bound access will happen: # nft add element t s { 1 comment test } Since set->klen is 1 or 2, it's fine to treate the element key as a u8 or u16 integer. Fixes: 665153ff5752 ("netfilter: nf_tables: add bitmap set type") Signed-off-by: Liping Zhang <zlpnobody@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-02-26netfilter: nft_set_bitmap: incorrect bitmap sizePablo Neira Ayuso1-1/+1
priv->bitmap_size stores the real bitmap size, instead of the full struct nft_bitmap object. Fixes: 665153ff5752 ("netfilter: nf_tables: add bitmap set type") Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-02-08netfilter: nf_tables: add bitmap set typePablo Neira Ayuso1-0/+314
This patch adds a new bitmap set type. This bitmap uses two bits to represent one element. These two bits determine the element state in the current and the future generation that fits into the nf_tables commit protocol. When dumping elements back to userspace, the two bits are expanded into a struct nft_set_ext object. If no NFTA_SET_DESC_SIZE is specified, the existing automatic set backend selection prefers bitmap over hash in case of keys whose size is <= 16 bit. If the set size is know, the bitmap set type is selected if with 16 bit kets and more than 390 elements in the set, otherwise the hash table set implementation is used. For 8 bit keys, the bitmap consumes 66 bytes. For 16 bit keys, the bitmap takes 16388 bytes. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>