aboutsummaryrefslogtreecommitdiffstats
path: root/net/netfilter/nft_hash.c
AgeCommit message (Collapse)Author
2016-07-11netfilter: nf_tables: get rid of possible_net_t from set and basechainPablo Neira Ayuso
We can pass the netns pointer as parameter to the functions that need to gain access to it. From basechains, I didn't find any client for this field anymore so let's remove this too. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-07-06Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-nextDavid S. Miller
Pablo Neira Ayuso says: ==================== Netfilter updates for net-next The following patchset contains Netfilter updates for net-next, they are: 1) Don't use userspace datatypes in bridge netfilter code, from Tobin Harding. 2) Iterate only once over the expectation table when removing the helper module, instead of once per-netns, from Florian Westphal. 3) Extra sanitization in xt_hook_ops_alloc() to return error in case we ever pass zero hooks, xt_hook_ops_alloc(): 4) Handle NFPROTO_INET from the logging core infrastructure, from Liping Zhang. 5) Autoload loggers when TRACE target is used from rules, this doesn't change the behaviour in case the user already selected nfnetlink_log as preferred way to print tracing logs, also from Liping Zhang. 6) Conntrack slabs with SLAB_HWCACHE_ALIGN to allow rearranging fields by cache lines, increases the size of entries in 11% per entry. From Florian Westphal. 7) Skip zone comparison if CONFIG_NF_CONNTRACK_ZONES=n, from Florian. 8) Remove useless defensive check in nf_logger_find_get() from Shivani Bhardwaj. 9) Remove zone extension as place it in the conntrack object, this is always include in the hashing and we expect more intensive use of zones since containers are in place. Also from Florian Westphal. 10) Owner match now works from any namespace, from Eric Bierdeman. 11) Make sure we only reply with TCP reset to TCP traffic from nf_reject_ipv4, patch from Liping Zhang. 12) Introduce --nflog-size to indicate amount of network packet bytes that are copied to userspace via log message, from Vishwanath Pai. This obsoletes --nflog-range that has never worked, it was designed to achieve this but it has never worked. 13) Introduce generic macros for nf_tables object generation masks. 14) Use generation mask in table, chain and set objects in nf_tables. This allows fixes interferences with ongoing preparation phase of the commit protocol and object listings going on at the same time. This update is introduced in three patches, one per object. 15) Check if the object is active in the next generation for element deactivation in the rbtree implementation, given that deactivation happens from the commit phase path we have to observe the future status of the object. 16) Support for deletion of just added elements in the hash set type. 17) Allow to resize hashtable from /proc entry, not only from the obscure /sys entry that maps to the module parameter, from Florian Westphal. 18) Get rid of NFT_BASECHAIN_DISABLED, this code is not exercised anymore since we tear down the ruleset whenever the netdevice goes away. 19) Support for matching inverted set lookups, from Arturo Borrero. 20) Simplify the iptables_mangle_hook() by removing a superfluous extra branch. 21) Introduce ether_addr_equal_masked() and use it from the netfilter codebase, from Joe Perches. 22) Remove references to "Use netfilter MARK value as routing key" from the Netfilter Kconfig description given that this toggle doesn't exists already for 10 years, from Moritz Sichert. 23) Introduce generic NF_INVF() and use it from the xtables codebase, from Joe Perches. 24) Setting logger to NONE via /proc was not working unless explicit nul-termination was included in the string. This fixes seems to leave the former behaviour there, so we don't break backward. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-24netfilter: nft_hash: support deletion of inactive elementsPablo Neira Ayuso
New elements are inactive in the preparation phase, and its NFT_SET_ELEM_BUSY_MASK flag is set on. This busy flag doesn't allow us to delete it from the same transaction, following a sequence like: begin transaction add element X delete element X end transaction This sequence is valid and may be triggered by robots. To resolve this problem, allow deactivating elements that are active in the current generation (ie. those that has been just added in this batch). Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-06-15netfilter: nf_tables: reject loops from set element jump to chainPablo Neira Ayuso
Liping Zhang says: "Users may add such a wrong nft rules successfully, which will cause an endless jump loop: # nft add rule filter test tcp dport vmap {1: jump test} This is because before we commit, the element in the current anonymous set is inactive, so osp->walk will skip this element and miss the validate check." To resolve this problem, this patch passes the generation mask to the walk function through the iter container structure depending on the code path: 1) If we're dumping the elements, then we have to check if the element is active in the current generation. Thus, we check for the current bit in the genmask. 2) If we're checking for loops, then we have to check if the element is active in the next generation, as we're in the middle of a transaction. Thus, we check for the next bit in the genmask. Based on original patch from Liping Zhang. Reported-by: Liping Zhang <liping.zhang@spreadtrum.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Tested-by: Liping Zhang <liping.zhang@spreadtrum.com>
2016-04-05rhashtable: accept GFP flags in rhashtable_walk_initBob Copeland
In certain cases, the 802.11 mesh pathtable code wants to iterate over all of the entries in the forwarding table from the receive path, which is inside an RCU read-side critical section. Enable walks inside atomic sections by allowing GFP_ATOMIC allocations for the walker state. Change all existing callsites to pass in GFP_KERNEL. Acked-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: Bob Copeland <me@bobcopeland.com> [also adjust gfs2/glock.c and rhashtable tests] Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2015-04-13netfilter: nf_tables: variable sized set element keys / dataPatrick McHardy
This patch changes sets to support variable sized set element keys / data up to 64 bytes each by using variable sized set extensions. This allows to use concatenations with bigger data items suchs as IPv6 addresses. As a side effect, small keys/data now don't require the full 16 bytes of struct nft_data anymore but just the space they need. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-04-13netfilter: nf_tables: convert sets to u32 data pointersPatrick McHardy
Simple conversion to use u32 pointers to the beginning of the data area to keep follow up patches smaller. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-04-13netfilter: nf_tables: kill nft_data_cmp()Patrick McHardy
Only needlessly complicates things due to requiring specific argument types. Use memcmp directly. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-04-13netfilter: nf_tables: get rid of NFT_REG_VERDICT usagePatrick McHardy
Replace the array of registers passed to expressions by a struct nft_regs, containing the verdict as a seperate member, which aliases to the NFT_REG_VERDICT register. This is needed to seperate the verdict from the data registers completely, so their size can be changed. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-04-08netfilter: nf_tables: add support for dynamic set updatesPatrick McHardy
Add a new "dynset" expression for dynamic set updates. A new set op ->update() is added which, for non existant elements, invokes an initialization callback and inserts the new element. For both new or existing elements the extenstion pointer is returned to the caller to optionally perform timer updates or other actions. Element removal is not supported so far, however that seems to be a rather exotic need and can be added later on. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-04-08netfilter: nf_tables: prepare set element accounting for async updatesPatrick McHardy
Use atomic operations for the element count to avoid races with async updates. To properly handle the transactional semantics during netlink updates, deleted but not yet committed elements are accounted for seperately and are treated as being already removed. This means for the duration of a netlink transaction, the limit might be exceeded by the amount of elements deleted. Set implementations must be prepared to handle this. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-04-01netfilter: nft_hash: add support for timeoutsPatrick McHardy
Add support for element timeouts to nft_hash. The lookup and walking functions are changed to ignore timed out elements, a periodic garbage collection task cleans out expired entries. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-03-26netfilter: nf_tables: implement set transaction supportPatrick McHardy
Set elements are the last object type not supporting transaction support. Implement similar to the existing rule transactions: The global transaction counter keeps track of two generations, current and next. Each element contains a bitmask specifying in which generations it is inactive. New elements start out as inactive in the current generation and active in the next. On commit, the previous next generation becomes the current generation and the element becomes active. The bitmask is then cleared to indicate that the element is active in all future generations. If the transaction is aborted, the element is removed from the set before it becomes active. When removing an element, it gets marked as inactive in the next generation. On commit the next generation becomes active and the therefor the element inactive. It is then taken out of then set and released. On abort, the element is marked as active for the next generation again. Lookups ignore elements not active in the current generation. The current set types (hash/rbtree) both use a field in the extension area to store the generation mask. This (currently) does not require any additional memory since we have some free space in there. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-03-26netfilter: nf_tables: return set extensions from ->lookup()Patrick McHardy
Return the extension area from the ->lookup() function to allow to consolidate common actions. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-03-26netfilter: nf_tables: consolide set element destructionPatrick McHardy
With the conversion to set extensions, it is now possible to consolidate the different set element destruction functions. The set implementations' ->remove() functions are changed to only take the element out of their internal data structures. Elements will be freed in a batched fashion after the global transaction's completion RCU grace period. This reduces the amount of grace periods required for nft_hash from N to zero additional ones, additionally this guarantees that the set elements' extensions of all implementations can be used under RCU protection. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-03-25netfilter: nf_tables: convert hash and rbtree to set extensionsPatrick McHardy
The set implementations' private struct will only contain the elements needed to maintain the search structure, all other elements are moved to the set extensions. Element allocation and initialization is performed centrally by nf_tables_api instead of by the different set implementations' ->insert() functions. A new "elemsize" member in the set ops specifies the amount of memory to reserve for internal usage. Destruction will also be moved out of the set implementations by a following patch. Except for element allocation, the patch is a simple conversion to using data from the extension area. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-03-25netfilter: nft_hash: convert to use rhashtable callbacksPatrick McHardy
A following patch will convert sets to use so called set extensions, where the key is not located in a fixed position anymore. This will require rhashtable hashing and comparison callbacks to be used. As preparation, convert nft_hash to use these callbacks without any functional changes. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-03-25netfilter: nft_hash: indent rhashtable parametersPatrick McHardy
Improve readability by indenting the parameter initialization. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-03-25netfilter: nft_hash: restore struct nft_hashPatrick McHardy
Following patches will add new private members, restore struct nft_hash as preparation. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-03-24rhashtable: Add rhashtable_free_and_destroy()Thomas Graf
rhashtable_destroy() variant which stops rehashes, iterates over the table and calls a callback to release resources. Avoids need for nft_hash to embed rhashtable internals and allows to get rid of the being_destroyed flag. It also saves a 2nd mutex lock upon destruction. Also fixes an RCU lockdep splash on nft set destruction due to calling rht_for_each_entry_safe() without holding bucket locks. Open code this loop as we need know that no mutations may occur in parallel. Signed-off-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-24rhashtable: Disable automatic shrinking by defaultThomas Graf
Introduce a new bool automatic_shrinking to require the user to explicitly opt-in to automatic shrinking of tables. Signed-off-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-23Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Conflicts: net/netfilter/nf_tables_core.c The nf_tables_core.c conflict was resolved using a conflict resolution from Stephen Rothwell as a guide. Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-20netfilter: Convert nft_hash to inlined rhashtableHerbert Xu
This patch converts nft_hash to the inlined rhashtable interface. This patch also replaces the call to rhashtable_lookup_compare with a straight rhashtable_lookup_fast because it's simply doing a memcmp (in fact nft_hash_lookup already uses memcmp instead of nft_data_cmp). Furthermore, the compare function is only meant to compare, it is not supposed to have side-effects. The current side-effect code can simply be moved into the nft_hash_get. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-13netfilter: Fix potential crash in nft_hash walkerHerbert Xu
When we get back an EAGAIN from rhashtable_walk_next we were treating it as a valid object which obviously doesn't work too well. Luckily this is hard to trigger so it seems nobody has run into it yet. This patch fixes it by redoing the next call when we get an EAGAIN. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-02-27rhashtable: remove indirection for grow/shrink decision functionsDaniel Borkmann
Currently, all real users of rhashtable default their grow and shrink decision functions to rht_grow_above_75() and rht_shrink_below_30(), so that there's currently no need to have this explicitly selectable. It can/should be generic and private inside rhashtable until a real use case pops up. Since we can make this private, we'll save us this additional indirection layer and can improve insertion/deletion time as well. Reference: http://patchwork.ozlabs.org/patch/443040/ Suggested-by: David S. Miller <davem@davemloft.net> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-02-04netfilter: Use rhashtable walk iteratorHerbert Xu
This patch gets rid of the manual rhashtable walk in nft_hash which touches rhashtable internals that should not be exposed. It does so by using the rhashtable iterator primitives. Note that I'm leaving nft_hash_destroy alone since it's only invoked on shutdown and it shouldn't be affected by changes to rhashtable internals (or at least not what I'm planning to change). Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-03rhashtable: Per bucket locks & deferred expansion/shrinkingThomas Graf
Introduces an array of spinlocks to protect bucket mutations. The number of spinlocks per CPU is configurable and selected based on the hash of the bucket. This allows for parallel insertions and removals of entries which do not share a lock. The patch also defers expansion and shrinking to a worker queue which allows insertion and removal from atomic context. Insertions and deletions may occur in parallel to it and are only held up briefly while the particular bucket is linked or unzipped. Mutations of the bucket table pointer is protected by a new mutex, read access is RCU protected. In the event of an expansion or shrinking, the new bucket table allocated is exposed as a so called future table as soon as the resize process starts. Lookups, deletions, and insertions will briefly use both tables. The future table becomes the main table after an RCU grace period and initial linking of the old to the new table was performed. Optimization of the chains to make use of the new number of buckets follows only the new table is in use. The side effect of this is that during that RCU grace period, a bucket traversal using any rht_for_each() variant on the main table will not see any insertions performed during the RCU grace period which would at that point land in the future table. The lookup will see them as it searches both tables if needed. Having multiple insertions and removals occur in parallel requires nelems to become an atomic counter. Signed-off-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-03nft_hash: Remove rhashtable_remove_pprev()Thomas Graf
The removal function of nft_hash currently stores a reference to the previous element during lookup which is used to optimize removal later on. This was possible because a lock is held throughout calling rhashtable_lookup() and rhashtable_remove(). With the introdution of deferred table resizing in parallel to lookups and insertions, the nftables lock will no longer synchronize all table mutations and the stored pprev may become invalid. Removing this optimization makes removal slightly more expensive on average but allows taking the resize cost out of the insert and remove path. Signed-off-by: Thomas Graf <tgraf@suug.ch> Cc: netfilter-devel@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-03rhashtable: Convert bucket iterators to take table and indexThomas Graf
This patch is in preparation to introduce per bucket spinlocks. It extends all iterator macros to take the bucket table and bucket index. It also introduces a new rht_dereference_bucket() to handle protected accesses to buckets. It introduces a barrier() to the RCU iterators to the prevent the compiler from caching the first element. The lockdep verifier is introduced as stub which always succeeds and properly implement in the next patch when the locks are introduced. Signed-off-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-03rhashtable: Do hashing inside of rhashtable_lookup_compare()Thomas Graf
Hash the key inside of rhashtable_lookup_compare() like rhashtable_lookup() does. This allows to simplify the hashing functions and keep them private. Signed-off-by: Thomas Graf <tgraf@suug.ch> Cc: netfilter-devel@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net>
2014-11-13rhashtable: Drop gfp_flags arg in insert/remove functionsThomas Graf
Reallocation is only required for shrinking and expanding and both rely on a mutex for synchronization and callers of rhashtable_init() are in non atomic context. Therefore, no reason to continue passing allocation hints through the API. Instead, use GFP_KERNEL and add __GFP_NOWARN | __GFP_NORETRY to allow for silent fall back to vzalloc() without the OOM killer jumping in as pointed out by Eric Dumazet and Eric W. Biederman. Signed-off-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-11-13rhashtable: Add parent argument to mutex_is_heldHerbert Xu
Currently mutex_is_held can only test locks in the that are global since it takes no arguments. This prevents rhashtable from being used in places where locks are lock, e.g., per-namespace locks. This patch adds a parent field to mutex_is_held and rhashtable_params so that local locks can be used (and tested). Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-11-13netfilter: Move mutex_is_held under PROVE_LOCKINGHerbert Xu
The rhashtable function mutex_is_held is only used when PROVE_LOCKING is enabled. This patch modifies netfilter so that we can rhashtable.h itself can later make mutex_is_held optional depending on PROVE_LOCKING. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-03netfilter: nft_hash: no need for rcu in the hash set destroy pathPablo Neira Ayuso
The sets are released from the rcu callback, after the rule is removed from the chain list, which implies that nfnetlink cannot update the hashes (thus, no resizing may occur) and no packets are walking on the set anymore. This resolves a lockdep splat in the nft_hash_destroy() path since the nfnl mutex is not held there. =============================== [ INFO: suspicious RCU usage. ] 3.16.0-rc2+ #168 Not tainted ------------------------------- net/netfilter/nft_hash.c:362 suspicious rcu_dereference_protected() usage! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 1 1 lock held by ksoftirqd/0/3: #0: (rcu_callback){......}, at: [<ffffffff81096393>] rcu_process_callbacks+0x27e/0x4c7 stack backtrace: CPU: 0 PID: 3 Comm: ksoftirqd/0 Not tainted 3.16.0-rc2+ #168 Hardware name: LENOVO 23259H1/23259H1, BIOS G2ET32WW (1.12 ) 05/30/2012 0000000000000001 ffff88011769bb98 ffffffff8142c922 0000000000000006 ffff880117694090 ffff88011769bbc8 ffffffff8107c3ff ffff8800cba52400 ffff8800c476bea8 ffff8800c476bea8 ffff8800cba52400 ffff88011769bc08 Call Trace: [<ffffffff8142c922>] dump_stack+0x4e/0x68 [<ffffffff8107c3ff>] lockdep_rcu_suspicious+0xfa/0x103 [<ffffffffa079931e>] nft_hash_destroy+0x50/0x137 [nft_hash] [<ffffffffa078cd57>] nft_set_destroy+0x11/0x2a [nf_tables] Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Acked-by: Thomas Graf <tgraf@suug.ch>
2014-08-02nftables: Convert nft_hash to use generic rhashtableThomas Graf
The sizing of the hash table and the practice of requiring a lookup to retrieve the pprev to be stored in the element cookie before the deletion of an entry is left intact. Signed-off-by: Thomas Graf <tgraf@suug.ch> Acked-by: Patrick McHardy <kaber@trash.net> Reviewed-by: Nikolay Aleksandrov <nikolay@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-05net: use the new API kvfree()WANG Cong
It is available since v3.15-rc5. Cc: Pablo Neira Ayuso <pablo@netfilter.org> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-04-02netfilter: nft_hash: use set global element counter instead of private onePatrick McHardy
Now that nf_tables performs global accounting of set elements, it is not needed in the hash type anymore. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2014-04-02netfilter: nf_tables: implement proper set selectionPatrick McHardy
The current set selection simply choses the first set type that provides the requested features, which always results in the rbtree being chosen by virtue of being the first set in the list. What we actually want to do is choose the implementation that can provide the requested features and is optimal from either a performance or memory perspective depending on the characteristics of the elements and the preferences specified by the user. The elements are not known when creating a set. Even if we would provide them for anonymous (literal) sets, we'd still have standalone sets where the elements are not known in advance. We therefore need an abstract description of the data charcteristics. The kernel already knows the size of the key, this patch starts by introducing a nested set description which so far contains only the maximum amount of elements. Based on this the set implementations are changed to provide an estimate of the required amount of memory and the lookup complexity class. The set ops have a new callback ->estimate() that is invoked during set selection. It receives a structure containing the attributes known to the kernel and is supposed to populate a struct nft_set_estimate with the complexity class and, in case the size is known, the complete amount of memory required, or the amount of memory required per element otherwise. Based on the policy specified by the user (performance/memory, defaulting to performance) the kernel will then select the best suited implementation. Even if the set implementation would allow to add more than the specified maximum amount of elements, they are enforced since new implementations might not be able to add more than maximum based on which they were selected. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2014-03-18netfilter: Add missing vmalloc.h include to nft_hash.cDavid S. Miller
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-07netfilter: nft_hash: bug fixes and resizingPatrick McHardy
The hash set type is very broken and was never meant to be merged in this state. Missing RCU synchronization on element removal, leaking chain refcounts when used as a verdict map, races during lookups, a fixed table size are probably just some of the problems. Luckily it is currently never chosen by the kernel when the rbtree type is also available. Rewrite it to be usable. The new implementation supports automatic hash table resizing using RCU, based on Paul McKenney's and Josh Triplett's algorithm "Optimized Resizing For RCU-Protected Hash Tables" described in [1]. Resizing doesn't require a second list head in the elements, it works by chosing a hash function that remaps elements to a predictable set of buckets, only resizing by integral factors and - during expansion: linking new buckets to the old bucket that contains elements for any of the new buckets, thereby creating imprecise chains, then incrementally seperating the elements until the new buckets only contain elements that hash directly to them. - during shrinking: linking the hash chains of all old buckets that hash to the same new bucket to form a single chain. Expansion requires at most the number of elements in the longest hash chain grace periods, shrinking requires a single grace period. Due to the requirement of having hash chains/elements linked to multiple buckets during resizing, homemade single linked lists are used instead of the existing list helpers, that don't support this in a clean fashion. As a side effect, the amount of memory required per element is reduced by one pointer. Expansion is triggered when the load factors exceeds 75%, shrinking when the load factor goes below 30%. Both operations are allowed to fail and will be retried on the next insertion or removal if their respective conditions still hold. [1] http://dl.acm.org/citation.cfm?id=2002181.2002192 Reviewed-by: Josh Triplett <josh@joshtriplett.org> Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-10-14netfilter: nf_tables: add netlink set APIPatrick McHardy
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>
2013-10-14netfilter: add nftablesPatrick McHardy
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>