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2016-11-08netfilter: conntrack: fix CT target for UNSPEC helpersFlorian Westphal1-3/+8
Thomas reports its not possible to attach the H.245 helper: iptables -t raw -A PREROUTING -p udp -j CT --helper H.245 iptables: No chain/target/match by that name. xt_CT: No such helper "H.245" This is because H.245 registers as NFPROTO_UNSPEC, but the CT target passes NFPROTO_IPV4/IPV6 to nf_conntrack_helper_try_module_get. We should treat UNSPEC as wildcard and ignore the l3num instead. Reported-by: Thomas Woerner <twoerner@redhat.com> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-09-24netfilter: Remove explicit rcu_read_lock in nf_hook_slowAaron Conole1-1/+1
All of the callers of nf_hook_slow already hold the rcu_read_lock, so this cleanup removes the recursive call. This is just a cleanup, as the locking code gracefully handles this situation. Signed-off-by: Aaron Conole <aconole@bytheb.org> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-09-12netfilter: nf_conntrack: simplify __nf_ct_try_assign_helper() return logicPablo Neira1-9/+6
Instead of several goto's just to return the result, simply return it. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-07-21netfilter: Add helper array register/unregister functionsGao Feng1-0/+57
Add nf_ct_helper_init(), nf_conntrack_helpers_register() and nf_conntrack_helpers_unregister() functions to avoid repetitive opencoded initialization in helpers. This patch keeps an id parameter for nf_ct_helper_init() not to break helper matching by name that has been inconsistently exposed to userspace through ports, eg. ftp-2121, and through an incremental id, eg. tftp-1. Signed-off-by: Gao Feng <fgao@ikuai8.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-07-11netfilter: nf_ct_helper: unlink helper again when hash resize happenLiping Zhang1-6/+13
From: Liping Zhang <liping.zhang@spreadtrum.com> Similar to ctnl_untimeout, when hash resize happened, we should try to do unhelp from the 0# bucket again. Signed-off-by: Liping Zhang <liping.zhang@spreadtrum.com> 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. Miller1-29/+32
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>
2016-06-07netfilter: helper: avoid extra expectation iterations on unregisterFlorian Westphal1-29/+32
The expectation table is not duplicated per net namespace anymore, so we can move the expectation table and conntrack table iteration out of the per-net loop. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-06-01Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nfDavid S. Miller1-5/+4
Pablo Neira Ayuso says: ==================== Netfilter fixes for net The following patchset contains Netfilter fixes for your net tree, they are: 1) Fix incorrect timestamp in nfnetlink_queue introduced when addressing y2038 safe timestamp, from Florian Westphal. 2) Get rid of leftover conntrack definition from the previous merge window, oneliner from Florian. 3) Make nf_queue handler pernet to resolve race on dereferencing the hook state structure with netns removal, from Eric Biederman. 4) Ensure clean exit on unregistered helper ports, from Taehee Yoo. 5) Restore FLOWI_FLAG_KNOWN_NH in nf_dup_ipv6. This got lost while generalizing xt_TEE to add packet duplication support in nf_tables, from Paolo Abeni. 6) Insufficient netlink NFTA_SET_TABLE attribute check in nf_tables_getset(), from Phil Turnbull. 7) Reject helper registration on duplicated ports via modparams. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-31netfilter: nf_ct_helper: bail out on duplicated helpersPablo Neira Ayuso1-5/+4
Don't allow registration of helpers using the same tuple: { l3proto, l4proto, src-port } We lookup for the helper from the packet path using this tuple through __nf_ct_helper_find(). Therefore, we have to avoid having two helpers with the same tuple to ensure predictible behaviour. Don't compare the helper string names anymore since it is valid to register two helpers with the same name, but using different tuples. This is also implicitly fixing up duplicated helper registration via ports= modparam since the name comparison was defeating the tuple duplication validation. Reported-by: Feng Gao <gfree.wind@gmail.com> Reported-by: Taehee Yoo <ap420073@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-05-06netfilter: conntrack: use a single expectation table for all namespacesFlorian Westphal1-1/+1
We already include netns address in the hash and compare the netns pointers during lookup, so even if namespaces have overlapping addresses entries will be spread across the expectation table. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-05-05netfilter: conntrack: use a single hashtable for all namespacesFlorian Westphal1-3/+3
We already include netns address in the hash and compare the netns pointers during lookup, so even if namespaces have overlapping addresses entries will be spread across the table. Assuming 64k bucket size, this change saves 0.5 mbyte per namespace on a 64bit system. NAT bysrc and expectation hash is still per namespace, those will changed too soon. Future patch will also make conntrack object slab cache global again. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-04-25netfilter: nf_ct_helper: disable automatic helper assignmentPablo Neira Ayuso1-2/+2
Four years ago we introduced a new sysctl knob to disable automatic helper assignment in 72110dfaa907 ("netfilter: nf_ct_helper: disable automatic helper assignment"). This knob kept this behaviour enabled by default to remain conservative. This measure was introduced to provide a secure way to configure iptables and connection tracking helpers through explicit rules. Give the time we have waited for this, let's turn off this by default now, worse case users still have a chance to recover the former behaviour by explicitly enabling this back through sysctl. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-01-20netfilter: nf_conntrack: use safer way to lock all bucketsSasha Levin1-1/+1
When we need to lock all buckets in the connection hashtable we'd attempt to lock 1024 spinlocks, which is way more preemption levels than supported by the kernel. Furthermore, this behavior was hidden by checking if lockdep is enabled, and if it was - use only 8 buckets(!). Fix this by using a global lock and synchronize all buckets on it when we need to lock them all. This is pretty heavyweight, but is only done when we need to resize the hashtable, and that doesn't happen often enough (or at all). Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Reviewed-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2014-10-30netfilter: fix spelling errorsstephen hemminger1-1/+1
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2014-03-07netfilter: conntrack: remove central spinlock nf_conntrack_lockJesper Dangaard Brouer1-4/+8
nf_conntrack_lock is a monolithic lock and suffers from huge contention on current generation servers (8 or more core/threads). Perf locking congestion is clear on base kernel: - 72.56% ksoftirqd/6 [kernel.kallsyms] [k] _raw_spin_lock_bh - _raw_spin_lock_bh + 25.33% init_conntrack + 24.86% nf_ct_delete_from_lists + 24.62% __nf_conntrack_confirm + 24.38% destroy_conntrack + 0.70% tcp_packet + 2.21% ksoftirqd/6 [kernel.kallsyms] [k] fib_table_lookup + 1.15% ksoftirqd/6 [kernel.kallsyms] [k] __slab_free + 0.77% ksoftirqd/6 [kernel.kallsyms] [k] inet_getpeer + 0.70% ksoftirqd/6 [nf_conntrack] [k] nf_ct_delete + 0.55% ksoftirqd/6 [ip_tables] [k] ipt_do_table This patch change conntrack locking and provides a huge performance improvement. SYN-flood attack tested on a 24-core E5-2695v2(ES) with 10Gbit/s ixgbe (with tool trafgen): Base kernel: 810.405 new conntrack/sec After patch: 2.233.876 new conntrack/sec Notice other floods attack (SYN+ACK or ACK) can easily be deflected using: # iptables -A INPUT -m state --state INVALID -j DROP # sysctl -w net/netfilter/nf_conntrack_tcp_loose=0 Use an array of hashed spinlocks to protect insertions/deletions of conntracks into the hash table. 1024 spinlocks seem to give good results, at minimal cost (4KB memory). Due to lockdep max depth, 1024 becomes 8 if CONFIG_LOCKDEP=y The hash resize is a bit tricky, because we need to take all locks in the array. A seqcount_t is used to synchronize the hash table users with the resizing process. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Reviewed-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2014-03-07netfilter: conntrack: seperate expect locking from nf_conntrack_lockJesper Dangaard Brouer1-11/+11
Netfilter expectations are protected with the same lock as conntrack entries (nf_conntrack_lock). This patch split out expectations locking to use it's own lock (nf_conntrack_expect_lock). Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Reviewed-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2014-03-07netfilter: conntrack: spinlock per cpu to protect special lists.Jesper Dangaard Brouer1-2/+9
One spinlock per cpu to protect dying/unconfirmed/template special lists. (These lists are now per cpu, a bit like the untracked ct) Add a @cpu field to nf_conn, to make sure we hold the appropriate spinlock at removal time. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Reviewed-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-04-18netfilter: add my copyright statementsPatrick McHardy1-0/+1
Add copyright statements to all netfilter files which have had significant changes done by myself in the past. Some notes: - nf_conntrack_ecache.c was incorrectly attributed to Rusty and Netfilter Core Team when it got split out of nf_conntrack_core.c. The copyrights even state a date which lies six years before it was written. It was written in 2005 by Harald and myself. - net/ipv{4,6}/netfilter.c, net/netfitler/nf_queue.c were missing copyright statements. I've added the copyright statement from net/netfilter/core.c, where this code originated - for nf_conntrack_proto_tcp.c I've also added Jozsef, since I didn't want it to give the wrong impression Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-04-05netfilter: nf_log: prepare net namespace support for loggersGao feng1-1/+1
This patch adds netns support to nf_log and it prepares netns support for existing loggers. It is composed of four major changes. 1) nf_log_register has been split to two functions: nf_log_register and nf_log_set. The new nf_log_register is used to globally register the nf_logger and nf_log_set is used for enabling pernet support from nf_loggers. Per netns is not yet complete after this patch, it comes in separate follow up patches. 2) Add net as a parameter of nf_log_bind_pf. Per netns is not yet complete after this patch, it only allows to bind the nf_logger to the protocol family from init_net and it skips other cases. 3) Adapt all nf_log_packet callers to pass netns as parameter. After this patch, this function only works for init_net. 4) Make the sysctl net/netfilter/nf_log pernet. Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-03-07Merge branch 'master' of git://1984.lsi.us.es/nfDavid S. Miller1-1/+10
Pablo Neira Ayuso says: ==================== The following patchset contains Netfilter fixes for your net tree, they are: * Don't generate audit log message if audit is not enabled, from Gao Feng. * Fix logging formatting for packets dropped by helpers, by Joe Perches. * Fix a compilation warning in nfnetlink if CONFIG_PROVE_RCU is not set, from Paul Bolle. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2013-03-02netfilter: nf_ct_helper: Fix logging for dropped packetsJoe Perches1-1/+10
Update nf_ct_helper_log to emit args along with the format. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-02-27hlist: drop the node parameter from iteratorsSasha Levin1-8/+5
I'm not sure why, but the hlist for each entry iterators were conceived list_for_each_entry(pos, head, member) The hlist ones were greedy and wanted an extra parameter: hlist_for_each_entry(tpos, pos, head, member) Why did they need an extra pos parameter? I'm not quite sure. Not only they don't really need it, it also prevents the iterator from looking exactly like the list iterator, which is unfortunate. Besides the semantic patch, there was some manual work required: - Fix up the actual hlist iterators in linux/list.h - Fix up the declaration of other iterators based on the hlist ones. - A very small amount of places were using the 'node' parameter, this was modified to use 'obj->member' instead. - Coccinelle didn't handle the hlist_for_each_entry_safe iterator properly, so those had to be fixed up manually. The semantic patch which is mostly the work of Peter Senna Tschudin is here: @@ iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host; type T; expression a,c,d,e; identifier b; statement S; @@ -T b; <+... when != b ( hlist_for_each_entry(a, - b, c, d) S | hlist_for_each_entry_continue(a, - b, c) S | hlist_for_each_entry_from(a, - b, c) S | hlist_for_each_entry_rcu(a, - b, c, d) S | hlist_for_each_entry_rcu_bh(a, - b, c, d) S | hlist_for_each_entry_continue_rcu_bh(a, - b, c) S | for_each_busy_worker(a, c, - b, d) S | ax25_uid_for_each(a, - b, c) S | ax25_for_each(a, - b, c) S | inet_bind_bucket_for_each(a, - b, c) S | sctp_for_each_hentry(a, - b, c) S | sk_for_each(a, - b, c) S | sk_for_each_rcu(a, - b, c) S | sk_for_each_from -(a, b) +(a) S + sk_for_each_from(a) S | sk_for_each_safe(a, - b, c, d) S | sk_for_each_bound(a, - b, c) S | hlist_for_each_entry_safe(a, - b, c, d, e) S | hlist_for_each_entry_continue_rcu(a, - b, c) S | nr_neigh_for_each(a, - b, c) S | nr_neigh_for_each_safe(a, - b, c, d) S | nr_node_for_each(a, - b, c) S | nr_node_for_each_safe(a, - b, c, d) S | - for_each_gfn_sp(a, c, d, b) S + for_each_gfn_sp(a, c, d) S | - for_each_gfn_indirect_valid_sp(a, c, d, b) S + for_each_gfn_indirect_valid_sp(a, c, d) S | for_each_host(a, - b, c) S | for_each_host_safe(a, - b, c, d) S | for_each_mesh_entry(a, - b, c, d) S ) ...+> [akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c] [akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c] [akpm@linux-foundation.org: checkpatch fixes] [akpm@linux-foundation.org: fix warnings] [akpm@linux-foudnation.org: redo intrusive kvm changes] Tested-by: Peter Senna Tschudin <peter.senna@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Gleb Natapov <gleb@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-18Merge branch 'master' of git://1984.lsi.us.es/nf-nextDavid S. Miller1-0/+19
Pablo Neira Ayuso says: ==================== The following patchset contain updates for your net-next tree, they are: * Fix (for just added) connlabel dependencies, from Florian Westphal. * Add aliasing support for conntrack, thus users can either use -m state or -m conntrack from iptables while using the same kernel module, from Jozsef Kadlecsik. * Some code refactoring for the CT target to merge common code in revision 0 and 1, from myself. * Add aliasing support for CT, based on patch from Jozsef Kadlecsik. * Add one mutex per nfnetlink subsystem, from myself. * Improved logging for packets that are dropped by helpers, from myself. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2013-02-18Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net into netDavid S. Miller1-1/+3
Pull in 'net' to take in the bug fixes that didn't make it into 3.8-final. Also, deal with the semantic conflict of the change made to net/ipv6/xfrm6_policy.c A missing rt6->n neighbour release was added to 'net', but in 'net-next' we no longer cache the neighbour entries in the ipv6 routes so that change is not appropriate there. Signed-off-by: David S. Miller <davem@davemloft.net>
2013-02-19netfilter: nf_ct_helper: better logging for dropped packetsPablo Neira Ayuso1-0/+19
Connection tracking helpers have to drop packets under exceptional situations. Currently, the user gets the following logging message in case that happens: nf_ct_%s: dropping packet ... However, depending on the helper, there are different reasons why a packet can be dropped. This patch modifies the existing code to provide more specific error message in the scope of each helper to help users to debug the reason why the packet has been dropped, ie: nf_ct_%s: dropping packet: reason ... Thanks to Joe Perches for many formatting suggestions. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-02-12netfilter: nf_ct_helper: don't discard helper if it is actually the sameFlorian Westphal1-1/+3
commit (32f5376 netfilter: nf_ct_helper: disable automatic helper re-assignment of different type) broke transparent proxy scenarios. For example, initial helper lookup might yield "ftp" (dport 21), while re-lookup after REDIRECT yields "ftp-2121". This causes the autoassign code to toss the ftp helper, even though these are just different instances of the same helper. Change the test to check for the helper function address instead of the helper address, as suggested by Pablo. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@gnumonks.org>
2013-01-23netfilter: nf_ct_helper: move initialization out of pernet_operationsGao feng1-28/+25
Move the global initial codes to the module_init/exit context. Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2012-11-18net: Don't export sysctls to unprivileged usersEric W. Biederman1-0/+4
In preparation for supporting the creation of network namespaces by unprivileged users, modify all of the per net sysctl exports and refuse to allow them to unprivileged users. This makes it safe for unprivileged users in general to access per net sysctls, and allows sysctls to be exported to unprivileged users on an individual basis as they are deemed safe. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-19netfilter: nf_ct_helper: disable automatic helper re-assignment of different typePablo Neira Ayuso1-1/+7
This patch modifies __nf_ct_try_assign_helper in a way that invalidates support for the following scenario: 1) attach the helper A for first time when the conntrack is created 2) attach new (different) helper B due to changes the reply tuple caused by NAT eg. port redirection from TCP/21 to TCP/5060 with both FTP and SIP helpers loaded, which seems to be a quite unorthodox scenario. I can provide a more elaborated patch to support this scenario but explicit helper attachment provides a better solution for this since now the use can attach the helpers consistently, without relying on the automatic helper lookup magic. This patch fixes a possible out of bound zeroing of the conntrack helper extension if the helper B uses more memory for its private data than helper A. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2012-06-16netfilter: add user-space connection tracking helper infrastructurePablo Neira Ayuso1-4/+17
There are good reasons to supports helpers in user-space instead: * Rapid connection tracking helper development, as developing code in user-space is usually faster. * Reliability: A buggy helper does not crash the kernel. Moreover, we can monitor the helper process and restart it in case of problems. * Security: Avoid complex string matching and mangling in kernel-space running in privileged mode. Going further, we can even think about running user-space helpers as a non-root process. * Extensibility: It allows the development of very specific helpers (most likely non-standard proprietary protocols) that are very likely not to be accepted for mainline inclusion in the form of kernel-space connection tracking helpers. This patch adds the infrastructure to allow the implementation of user-space conntrack helpers by means of the new nfnetlink subsystem `nfnetlink_cthelper' and the existing queueing infrastructure (nfnetlink_queue). I had to add the new hook NF_IP6_PRI_CONNTRACK_HELPER to register ipv[4|6]_helper which results from splitting ipv[4|6]_confirm into two pieces. This change is required not to break NAT sequence adjustment and conntrack confirmation for traffic that is enqueued to our user-space conntrack helpers. Basic operation, in a few steps: 1) Register user-space helper by means of `nfct': nfct helper add ftp inet tcp [ It must be a valid existing helper supported by conntrack-tools ] 2) Add rules to enable the FTP user-space helper which is used to track traffic going to TCP port 21. For locally generated packets: iptables -I OUTPUT -t raw -p tcp --dport 21 -j CT --helper ftp For non-locally generated packets: iptables -I PREROUTING -t raw -p tcp --dport 21 -j CT --helper ftp 3) Run the test conntrackd in helper mode (see example files under doc/helper/conntrackd.conf conntrackd 4) Generate FTP traffic going, if everything is OK, then conntrackd should create expectations (you can check that with `conntrack': conntrack -E expect [NEW] 301 proto=6 src=192.168.1.136 dst=130.89.148.12 sport=0 dport=54037 mask-src=255.255.255.255 mask-dst=255.255.255.255 sport=0 dport=65535 master-src=192.168.1.136 master-dst=130.89.148.12 sport=57127 dport=21 class=0 helper=ftp [DESTROY] 301 proto=6 src=192.168.1.136 dst=130.89.148.12 sport=0 dport=54037 mask-src=255.255.255.255 mask-dst=255.255.255.255 sport=0 dport=65535 master-src=192.168.1.136 master-dst=130.89.148.12 sport=57127 dport=21 class=0 helper=ftp This confirms that our test helper is receiving packets including the conntrack information, and adding expectations in kernel-space. The user-space helper can also store its private tracking information in the conntrack structure in the kernel via the CTA_HELP_INFO. The kernel will consider this a binary blob whose layout is unknown. This information will be included in the information that is transfered to user-space via glue code that integrates nfnetlink_queue and ctnetlink. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2012-06-16netfilter: nf_ct_helper: implement variable length helper private dataPablo Neira Ayuso1-4/+7
This patch uses the new variable length conntrack extensions. Instead of using union nf_conntrack_help that contain all the helper private data information, we allocate variable length area to store the private helper data. This patch includes the modification of all existing helpers. It also includes a couple of include header to avoid compilation warnings. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2012-05-08netfilter: nf_conntrack: fix explicit helper attachment and NATPablo Neira Ayuso1-1/+12
Explicit helper attachment via the CT target is broken with NAT if non-standard ports are used. This problem was hidden behind the automatic helper assignment routine. Thus, it becomes more noticeable now that we can disable the automatic helper assignment with Eric Leblond's: 9e8ac5a netfilter: nf_ct_helper: allow to disable automatic helper assignment Basically, nf_conntrack_alter_reply asks for looking up the helper up if NAT is enabled. Unfortunately, we don't have the conntrack template at that point anymore. Since we don't want to rely on the automatic helper assignment, we can skip the second look-up and stick to the helper that was attached by iptables. With the CT target, the user is in full control of helper attachment, thus, the policy is to trust what the user explicitly configures via iptables (no automatic magic anymore). Interestingly, this bug was hidden by the automatic helper look-up code. But it can be easily trigger if you attach the helper in a non-standard port, eg. iptables -I PREROUTING -t raw -p tcp --dport 8888 \ -j CT --helper ftp And you disabled the automatic helper assignment. I added the IPS_HELPER_BIT that allows us to differenciate between a helper that has been explicitly attached and those that have been automatically assigned. I didn't come up with a better solution (having backward compatibility in mind). Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2012-05-08netfilter: nf_ct_helper: allow to disable automatic helper assignmentEric Leblond1-11/+98
This patch allows you to disable automatic conntrack helper lookup based on TCP/UDP ports, eg. echo 0 > /proc/sys/net/netfilter/nf_conntrack_helper [ Note: flows that already got a helper will keep using it even if automatic helper assignment has been disabled ] Once this behaviour has been disabled, you have to explicitly use the iptables CT target to attach helper to flows. There are good reasons to stop supporting automatic helper assignment, for further information, please read: http://www.netfilter.org/news.html#2012-04-03 This patch also adds one message to inform that automatic helper assignment is deprecated and it will be removed soon (this is spotted only once, with the first flow that gets a helper attached to make it as less annoying as possible). Signed-off-by: Eric Leblond <eric@regit.org> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2012-03-07netfilter: ctnetlink: allow to set expectfn for expectationsPablo Neira Ayuso1-0/+54
This patch allows you to set expectfn which is specifically used by the NAT side of most of the existing conntrack helpers. I have added a symbol map that uses a string as key to look up for the function that is attached to the expectation object. This is the best solution I came out with to solve this issue. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2012-01-16netfilter: revert user-space expectation helper supportPablo Neira Ayuso1-12/+0
This patch partially reverts: 3d058d7 netfilter: rework user-space expectation helper support that was applied during the 3.2 development cycle. After this patch, the tree remains just like before patch bc01bef, that initially added the preliminary infrastructure. I decided to partially revert this patch because the approach that I proposed to resolve this problem is broken in NAT setups. Moreover, a new infrastructure will be submitted for the 3.3.x development cycle that resolve the existing issues while providing a neat solution. Since nobody has been seriously using this infrastructure in user-space, the removal of this feature should affect any know FOSS project (to my knowledge). Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2012-01-12net: reintroduce missing rcu_assign_pointer() callsEric Dumazet1-1/+1
commit a9b3cd7f32 (rcu: convert uses of rcu_assign_pointer(x, NULL) to RCU_INIT_POINTER) did a lot of incorrect changes, since it did a complete conversion of rcu_assign_pointer(x, y) to RCU_INIT_POINTER(x, y). We miss needed barriers, even on x86, when y is not NULL. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> CC: Stephen Hemminger <shemminger@vyatta.com> CC: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-23netfilter: rework user-space expectation helper supportPablo Neira Ayuso1-0/+12
This partially reworks bc01befdcf3e40979eb518085a075cbf0aacede0 which added userspace expectation support. This patch removes the nf_ct_userspace_expect_list since now we force to use the new iptables CT target feature to add the helper extension for conntracks that have attached expectations from userspace. A new version of the proof-of-concept code to implement userspace helpers from userspace is available at: http://people.netfilter.org/pablo/userspace-conntrack-helpers/nf-ftp-helper-POC.tar.bz2 This patch also modifies the CT target to allow to set the conntrack's userspace helper status flags. This flag is used to tell the conntrack system to explicitly allocate the helper extension. This helper extension is useful to link the userspace expectations with the master conntrack that is being tracked from one userspace helper. This feature fixes a problem in the current approach of the userspace helper support. Basically, if the master conntrack that has got a userspace expectation vanishes, the expectations point to one invalid memory address. Thus, triggering an oops in the expectation deletion event path. I decided not to add a new revision of the CT target because I only needed to add a new flag for it. I'll document in this issue in the iptables manpage. I have also changed the return value from EINVAL to EOPNOTSUPP if one flag not supported is specified. Thus, in the future adding new features that only require a new flag can be added without a new revision. There is no official code using this in userspace (apart from the proof-of-concept) that uses this infrastructure but there will be some by beginning 2012. Reported-by: Sam Roberts <vieuxtech@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2011-08-02rcu: convert uses of rcu_assign_pointer(x, NULL) to RCU_INIT_POINTERStephen Hemminger1-3/+3
When assigning a NULL value to an RCU protected pointer, no barrier is needed. The rcu_assign_pointer, used to handle that but will soon change to not handle the special case. Convert all rcu_assign_pointer of NULL value. //smpl @@ expression P; @@ - rcu_assign_pointer(P, NULL) + RCU_INIT_POINTER(P, NULL) // </smpl> Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-14netfilter: nf_conntrack: use is_vmalloc_addr()Patrick McHardy1-7/+3
Use is_vmalloc_addr() in nf_ct_free_hashtable() and get rid of the vmalloc flags to indicate that a hash table has been allocated using vmalloc(). Signed-off-by: Patrick McHardy <kaber@trash.net>
2010-11-15netfilter: rcu sparse cleanupsEric Dumazet1-2/+8
Use RCU helpers to reduce number of sparse warnings (CONFIG_SPARSE_RCU_POINTER=y), and adds lockdep checks. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Patrick McHardy <kaber@trash.net>
2010-03-30include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.hTejun Heo1-1/+0
percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-02-10Merge branch 'master' of /repos/git/net-next-2.6Patrick McHardy1-1/+1
Signed-off-by: Patrick McHardy <kaber@trash.net>
2010-02-08netfilter: nf_conntrack: fix hash resizing with namespacesPatrick McHardy1-1/+1
As noticed by Jon Masters <jonathan@jonmasters.org>, the conntrack hash size is global and not per namespace, but modifiable at runtime through /sys/module/nf_conntrack/hashsize. Changing the hash size will only resize the hash in the current namespace however, so other namespaces will use an invalid hash size. This can cause crashes when enlarging the hashsize, or false negative lookups when shrinking it. Move the hash size into the per-namespace data and only use the global hash size to initialize the per-namespace value when instanciating a new namespace. Additionally restrict hash resizing to init_net for now as other namespaces are not handled currently. Cc: stable@kernel.org Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-03netfilter: xtables: add CT targetPatrick McHardy1-0/+19
Add a new target for the raw table, which can be used to specify conntrack parameters for specific connections, f.i. the conntrack helper. The target attaches a "template" connection tracking entry to the skb, which is used by the conntrack core when initializing a new conntrack. Signed-off-by: Patrick McHardy <kaber@trash.net>
2010-02-03netfilter: nf_conntrack: support conntrack templatesPatrick McHardy1-4/+13
Support initializing selected parameters of new conntrack entries from a "conntrack template", which is a specially marked conntrack entry attached to the skb. Currently the helper and the event delivery masks can be initialized this way. Signed-off-by: Patrick McHardy <kaber@trash.net>
2010-02-03netfilter: ctnetlink: only assign helpers for matching protocolsPatrick McHardy1-3/+5
Make sure not to assign a helper for a different network or transport layer protocol to a connection. Additionally change expectation deletion by helper to compare the name directly - there might be multiple helper registrations using the same name, currently one of them is chosen in an unpredictable manner and only those expectations are removed. Signed-off-by: Patrick McHardy <kaber@trash.net>
2009-06-13netfilter: conntrack: move helper destruction to nf_ct_helper_destroy()Pablo Neira Ayuso1-0/+14
This patch moves the helper destruction to a function that lives in nf_conntrack_helper.c. This new function is used in the patch to add ctnetlink reliable event delivery. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Patrick McHardy <kaber@trash.net>
2009-04-15netfilter: nf_conntrack: fix crash when unloading helpersPatrick McHardy1-1/+1
Commit ea781f197d (netfilter: nf_conntrack: use SLAB_DESTROY_BY_RCU and) get rid of call_rcu() was missing one conversion to the hlist_nulls functions, causing a crash when unloading conntrack helper modules. Reported-and-tested-by: Mariusz Kozlowski <m.kozlowski@tuxland.pl> Signed-off-by: Patrick McHardy <kaber@trash.net>
2009-03-25netfilter: nf_conntrack: use SLAB_DESTROY_BY_RCU and get rid of call_rcu()Eric Dumazet1-3/+4
Use "hlist_nulls" infrastructure we added in 2.6.29 for RCUification of UDP & TCP. This permits an easy conversion from call_rcu() based hash lists to a SLAB_DESTROY_BY_RCU one. Avoiding call_rcu() delay at nf_conn freeing time has numerous gains. First, it doesnt fill RCU queues (up to 10000 elements per cpu). This reduces OOM possibility, if queued elements are not taken into account This reduces latency problems when RCU queue size hits hilimit and triggers emergency mode. - It allows fast reuse of just freed elements, permitting better use of CPU cache. - We delete rcu_head from "struct nf_conn", shrinking size of this structure by 8 or 16 bytes. This patch only takes care of "struct nf_conn". call_rcu() is still used for less critical conntrack parts, that may be converted later if necessary. Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: Patrick McHardy <kaber@trash.net>
2009-03-25netfilter: limit the length of the helper nameHolger Eitzenberger1-0/+1
This is necessary in order to have an upper bound for Netlink message calculation, which is not a problem at all, as there are no helpers with a longer name. Signed-off-by: Holger Eitzenberger <holger@eitzenberger.org> Signed-off-by: Patrick McHardy <kaber@trash.net>