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path: root/include/net/netfilter/nf_conntrack.h
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2019-09-13netfilter: conntrack: move code to linux/nf_conntrack_common.h.Jeremy Sowden
Move some `struct nf_conntrack` code from linux/skbuff.h to linux/nf_conntrack_common.h. Together with a couple of helpers for getting and setting skb->_nfct, it allows us to remove CONFIG_NF_CONNTRACK checks from net/netfilter/nf_conntrack.h. Signed-off-by: Jeremy Sowden <jeremy@azazel.net> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-09-13netfilter: remove nf_conntrack_icmpv6.h header.Jeremy Sowden
nf_conntrack_icmpv6.h contains two object macros which duplicate macros in linux/icmpv6.h. The latter definitions are also visible wherever it is included, so remove it. Signed-off-by: Jeremy Sowden <jeremy@azazel.net> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-08-13netfilter: add missing IS_ENABLED(CONFIG_NF_CONNTRACK) checks to some ↵Jeremy Sowden
header-files. struct nf_conn contains a "struct nf_conntrack ct_general" member and struct net contains a "struct netns_ct ct" member which are both only defined in CONFIG_NF_CONNTRACK is enabled. These members are used in a number of inline functions defined in other header-files. Added preprocessor checks to make sure the headers will compile if CONFIG_NF_CONNTRACK is disabled. Signed-off-by: Jeremy Sowden <jeremy@azazel.net> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-06-17netfilter: conntrack: small conntrack lookup optimizationFlorian Westphal
____nf_conntrack_find() performs checks on the conntrack objects in this order: 1. if (nf_ct_is_expired(ct)) This fetches ct->timeout, in third cache line. The hnnode that is used to store the list pointers resides in the first (origin) or second (reply tuple) cache lines. This test rarely passes, but its necessary to reap obsolete entries. 2. if (nf_ct_is_dying(ct)) This fetches ct->status, also in third cache line. The test is useless, and can be removed: Consider: cpu0 cpu1 ct = ____nf_conntrack_find() atomic_inc_not_zero(ct) -> ok nf_ct_key_equal -> ok is_dying -> DYING bit not set, ok set_bit(ct, DYING); ... unhash ... etc. return ct -> returning a ct with dying bit set, despite having a test for it. This (unlikely) case is fine - refcount prevents ct from getting free'd. 3. if (nf_ct_key_equal(h, tuple, zone, net)) nf_ct_key_equal checks in following order: 1. Tuple equal (first or second cacheline) 2. Zone equal (third cacheline) 3. confirmed bit set (->status, third cacheline) 4. net namespace match (third cacheline). Swapping "timeout" and "cpu" places timeout in the first cacheline. This has two advantages: 1. For a conntrack that won't even match the original tuple, we will now only fetch the first and maybe the second cacheline instead of always accessing the 3rd one as well. 2. in case of TCP ct->timeout changes frequently because we reduce/increase it when there are packets outstanding in the network. The first cacheline contains both the reference count and the ct spinlock, i.e. moving timeout there avoids writes to 3rd cacheline. The restart sequence in __nf_conntrack_find() is removed, if we found a candidate, but then fail to increment the refcount or discover the tuple has changed (object recycling), just pretend we did not find an entry. A second lookup won't find anything until another CPU adds a new conntrack with identical tuple into the hash table, which is very unlikely. We have the confirmation-time checks (when we hold hash lock) that deal with identical entries and even perform clash resolution in some cases. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-05-30netfilter: nf_conntrack: allow to register bridge supportPablo Neira Ayuso
This patch adds infrastructure to register and to unregister bridge support for the conntrack module via nf_ct_bridge_register() and nf_ct_bridge_unregister(). Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-15netfilter: ctnetlink: don't use conntrack/expect object addresses as idFlorian Westphal
else, we leak the addresses to userspace via ctnetlink events and dumps. Compute an ID on demand based on the immutable parts of nf_conn struct. Another advantage compared to using an address is that there is no immediate re-use of the same ID in case the conntrack entry is freed and reallocated again immediately. Fixes: 3583240249ef ("[NETFILTER]: nf_conntrack_expect: kill unique ID") Fixes: 7f85f914721f ("[NETFILTER]: nf_conntrack: kill unique ID") Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-02-27netfilter: conntrack: avoid same-timeout updateFlorian Westphal
No need to dirty a cache line if timeout is unchanged. Also, WARN() is useless here: we crash on 'skb->len' access if skb is NULL. Last, ct->timeout is u32, not 'unsigned long' so adapt the function prototype accordingly. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-01-18netfilter: conntrack: avoid unneeded nf_conntrack_l4proto lookupsFlorian Westphal
after removal of the packet and invert function pointers, several places do not need to lookup the l4proto structure anymore. Remove those lookups. The function nf_ct_invert_tuplepr becomes redundant, replace it with nf_ct_invert_tuple everywhere. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-12-21netfilter: conntrack: udp: only extend timeout to stream mode after 2sFlorian Westphal
Currently DNS resolvers that send both A and AAAA queries from same source port can trigger stream mode prematurely, which results in non-early-evictable conntrack entry for three minutes, even though DNS requests are done in a few milliseconds. Add a two second grace period where we continue to use the ordinary 30-second default timeout. Its enough for DNS request/response traffic, even if two request/reply packets are involved. ASSURED is still set, else conntrack (and thus a possible NAT mapping ...) gets zapped too in case conntrack table runs full. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-08-03netfilter: use kvmalloc_array to allocate memory for hashtableLi RongQing
nf_ct_alloc_hashtable is used to allocate memory for conntrack, NAT bysrc and expectation hashtable. Assuming 64k bucket size, which means 7th order page allocation, __get_free_pages, called by nf_ct_alloc_hashtable, will trigger the direct memory reclaim and stall for a long time, when system has lots of memory stress so replace combination of __get_free_pages and vzalloc with kvmalloc_array, which provides a overflow check and a fallback if no high order memory is available, and do not retry to reclaim memory, reduce stall and remove nf_ct_free_hashtable, since it is just a kvfree Signed-off-by: Zhang Yu <zhangyu31@baidu.com> Signed-off-by: Wang Li <wangli39@baidu.com> Signed-off-by: Li RongQing <lirongqing@baidu.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-07-17netfilter: conntrack: remove l3proto abstractionFlorian Westphal
This unifies ipv4 and ipv6 protocol trackers and removes the l3proto abstraction. This gets rid of all l3proto indirect calls and the need to do a lookup on the function to call for l3 demux. It increases module size by only a small amount (12kbyte), so this reduces size because nf_conntrack.ko is useless without either nf_conntrack_ipv4 or nf_conntrack_ipv6 module. before: text data bss dec hex filename 7357 1088 0 8445 20fd nf_conntrack_ipv4.ko 7405 1084 4 8493 212d nf_conntrack_ipv6.ko 72614 13689 236 86539 1520b nf_conntrack.ko 19K nf_conntrack_ipv4.ko 19K nf_conntrack_ipv6.ko 179K nf_conntrack.ko after: text data bss dec hex filename 79277 13937 236 93450 16d0a nf_conntrack.ko 191K nf_conntrack.ko Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-02-07netfilter: remove useless prototypeTaehee Yoo
prototype nf_ct_nat_offset is not used anymore. Signed-off-by: Taehee Yoo <ap420073@gmail.com>
2017-11-15Merge tag 'modules-for-v4.15' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux Pull module updates from Jessica Yu: "Summary of modules changes for the 4.15 merge window: - treewide module_param_call() cleanup, fix up set/get function prototype mismatches, from Kees Cook - minor code cleanups" * tag 'modules-for-v4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux: module: Do not paper over type mismatches in module_param_call() treewide: Fix function prototypes for module_param_call() module: Prepare to convert all module_param_call() prototypes kernel/module: Delete an error message for a failed memory allocation in add_module_usage()
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-31treewide: Fix function prototypes for module_param_call()Kees Cook
Several function prototypes for the set/get functions defined by module_param_call() have a slightly wrong argument types. This fixes those in an effort to clean up the calls when running under type-enforced compiler instrumentation for CFI. This is the result of running the following semantic patch: @match_module_param_call_function@ declarer name module_param_call; identifier _name, _set_func, _get_func; expression _arg, _mode; @@ module_param_call(_name, _set_func, _get_func, _arg, _mode); @fix_set_prototype depends on match_module_param_call_function@ identifier match_module_param_call_function._set_func; identifier _val, _param; type _val_type, _param_type; @@ int _set_func( -_val_type _val +const char * _val , -_param_type _param +const struct kernel_param * _param ) { ... } @fix_get_prototype depends on match_module_param_call_function@ identifier match_module_param_call_function._get_func; identifier _val, _param; type _val_type, _param_type; @@ int _get_func( -_val_type _val +char * _val , -_param_type _param +const struct kernel_param * _param ) { ... } Two additional by-hand changes are included for places where the above Coccinelle script didn't notice them: drivers/platform/x86/thinkpad_acpi.c fs/lockd/svc.c Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Jessica Yu <jeyu@kernel.org>
2017-09-08netfilter: nat: Revert "netfilter: nat: convert nat bysrc hash to rhashtable"Florian Westphal
This reverts commit 870190a9ec9075205c0fa795a09fa931694a3ff1. It was not a good idea. The custom hash table was a much better fit for this purpose. A fast lookup is not essential, in fact for most cases there is no lookup at all because original tuple is not taken and can be used as-is. What needs to be fast is insertion and deletion. rhlist removal however requires a rhlist walk. We can have thousands of entries in such a list if source port/addresses are reused for multiple flows, if this happens removal requests are so expensive that deletions of a few thousand flows can take several seconds(!). The advantages that we got from rhashtable are: 1) table auto-sizing 2) multiple locks 1) would be nice to have, but it is not essential as we have at most one lookup per new flow, so even a million flows in the bysource table are not a problem compared to current deletion cost. 2) is easy to add to custom hash table. I tried to add hlist_node to rhlist to speed up rhltable_remove but this isn't doable without changing semantics. rhltable_remove_fast will check that the to-be-deleted object is part of the table and that requires a list walk that we want to avoid. Furthermore, using hlist_node increases size of struct rhlist_head, which in turn increases nf_conn size. Link: https://bugzilla.kernel.org/show_bug.cgi?id=196821 Reported-by: Ivan Babrou <ibobrik@gmail.com> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-09-04net: Remove CONFIG_NETFILTER_DEBUG and _ASSERT() macros.Varsha Rao
This patch removes CONFIG_NETFILTER_DEBUG and _ASSERT() macros as they are no longer required. Replace _ASSERT() macros with WARN_ON(). Signed-off-by: Varsha Rao <rvarsha016@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-09-04net: Replace NF_CT_ASSERT() with WARN_ON().Varsha Rao
This patch removes NF_CT_ASSERT() and instead uses WARN_ON(). Signed-off-by: Varsha Rao <rvarsha016@gmail.com>
2017-07-31netfilter: add and use nf_ct_unconfirmed_destroyFlorian Westphal
This also removes __nf_ct_unconfirmed_destroy() call from nf_ct_iterate_cleanup_net, so that function can be used only when missing conntracks from unconfirmed list isn't a problem. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-05-29netfilter: conntrack: add nf_ct_iterate_destroyFlorian Westphal
sledgehammer to be used on module unload (to remove affected conntracks from all namespaces). It will also flag all unconfirmed conntracks as dying, i.e. they will not be committed to main table. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-05-29netfilter: conntrack: rename nf_ct_iterate_cleanupFlorian Westphal
There are several places where we needlesly call nf_ct_iterate_cleanup, we should instead iterate the full table at module unload time. This is a leftover from back when the conntrack table got duplicated per net namespace. So rename nf_ct_iterate_cleanup to nf_ct_iterate_cleanup_net. A later patch will then add a non-net variant. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-04-19netfilter: conntrack: move helper struct to nf_conntrack_helper.hFlorian Westphal
its definition is not needed in nf_conntrack.h. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-04-15netfilter: remove nf_ct_is_untrackedFlorian Westphal
This function is now obsolete and always returns false. This change has no effect on generated code. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-04-15netfilter: kill the fake untracked conntrack objectsFlorian Westphal
resurrect an old patch from Pablo Neira to remove the untracked objects. Currently, there are four possible states of an skb wrt. conntrack. 1. No conntrack attached, ct is NULL. 2. Normal (kmem cache allocated) ct attached. 3. a template (kmalloc'd), not in any hash tables at any point in time 4. the 'untracked' conntrack, a percpu nf_conn object, tagged via IPS_UNTRACKED_BIT in ct->status. Untracked is supposed to be identical to case 1. It exists only so users can check -m conntrack --ctstate UNTRACKED vs. -m conntrack --ctstate INVALID e.g. attempts to set connmark on INVALID or UNTRACKED conntracks is supposed to be a no-op. Thus currently we need to check ct == NULL || nf_ct_is_untracked(ct) in a lot of places in order to avoid altering untracked objects. The other consequence of the percpu untracked object is that all -j NOTRACK (and, later, kfree_skb of such skbs) result in an atomic op (inc/dec the untracked conntracks refcount). This adds a new kernel-private ctinfo state, IP_CT_UNTRACKED, to make the distinction instead. The (few) places that care about packet invalid (ct is NULL) vs. packet untracked now need to test ct == NULL vs. ctinfo == IP_CT_UNTRACKED, but all other places can omit the nf_ct_is_untracked() check. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-03-13netfilter: Force fake conntrack entry to be at least 8 bytes alignedSteven Rostedt (VMware)
Since the nfct and nfctinfo have been combined, the nf_conn structure must be at least 8 bytes aligned, as the 3 LSB bits are used for the nfctinfo. But there's a fake nf_conn structure to denote untracked connections, which is created by a PER_CPU construct. This does not guarantee that it will be 8 bytes aligned and can break the logic in determining the correct nfctinfo. I triggered this on a 32bit machine with the following error: BUG: unable to handle kernel NULL pointer dereference at 00000af4 IP: nf_ct_deliver_cached_events+0x1b/0xfb *pdpt = 0000000031962001 *pde = 0000000000000000 Oops: 0000 [#1] SMP [Modules linked in: ip6t_REJECT nf_reject_ipv6 nf_conntrack_ipv6 nf_defrag_ipv6 ip6table_filter ip6_tables ipv6 crc_ccitt ppdev r8169 parport_pc parport OK ] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.10.0-test+ #75 Hardware name: MSI MS-7823/CSM-H87M-G43 (MS-7823), BIOS V1.6 02/22/2014 task: c126ec00 task.stack: c1258000 EIP: nf_ct_deliver_cached_events+0x1b/0xfb EFLAGS: 00010202 CPU: 0 EAX: 0021cd01 EBX: 00000000 ECX: 27b0c767 EDX: 32bcb17a ESI: f34135c0 EDI: f34135c0 EBP: f2debd60 ESP: f2debd3c DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068 CR0: 80050033 CR2: 00000af4 CR3: 309a0440 CR4: 001406f0 Call Trace: <SOFTIRQ> ? ipv6_skip_exthdr+0xac/0xcb ipv6_confirm+0x10c/0x119 [nf_conntrack_ipv6] nf_hook_slow+0x22/0xc7 nf_hook+0x9a/0xad [ipv6] ? ip6t_do_table+0x356/0x379 [ip6_tables] ? ip6_fragment+0x9e9/0x9e9 [ipv6] ip6_output+0xee/0x107 [ipv6] ? ip6_fragment+0x9e9/0x9e9 [ipv6] dst_output+0x36/0x4d [ipv6] NF_HOOK.constprop.37+0xb2/0xba [ipv6] ? icmp6_dst_alloc+0x2c/0xfd [ipv6] ? local_bh_enable+0x14/0x14 [ipv6] mld_sendpack+0x1c5/0x281 [ipv6] ? mark_held_locks+0x40/0x5c mld_ifc_timer_expire+0x1f6/0x21e [ipv6] call_timer_fn+0x135/0x283 ? detach_if_pending+0x55/0x55 ? mld_dad_timer_expire+0x3e/0x3e [ipv6] __run_timers+0x111/0x14b ? mld_dad_timer_expire+0x3e/0x3e [ipv6] run_timer_softirq+0x1c/0x36 __do_softirq+0x185/0x37c ? test_ti_thread_flag.constprop.19+0xd/0xd do_softirq_own_stack+0x22/0x28 </SOFTIRQ> irq_exit+0x5a/0xa4 smp_apic_timer_interrupt+0x2a/0x34 apic_timer_interrupt+0x37/0x3c By using DEFINE/DECLARE_PER_CPU_ALIGNED we can enforce at least 8 byte alignment as all cache line sizes are at least 8 bytes or more. Fixes: a9e419dc7be6 ("netfilter: merge ctinfo into nfct pointer storage area") Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Acked-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-02-02netfilter: merge ctinfo into nfct pointer storage areaFlorian Westphal
After this change conntrack operations (lookup, creation, matching from ruleset) only access one instead of two sk_buff cache lines. This works for normal conntracks because those are allocated from a slab that guarantees hw cacheline or 8byte alignment (whatever is larger) so the 3 bits needed for ctinfo won't overlap with nf_conn addresses. Template allocation now does manual address alignment (see previous change) on arches that don't have sufficent kmalloc min alignment. Some spots intentionally use skb->_nfct instead of skb_nfct() helpers, this is to avoid undoing the skb_nfct() use when we remove untracked conntrack object in the future. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-02-02netfilter: guarantee 8 byte minalign for template addressesFlorian Westphal
The next change will merge skb->nfct pointer and skb->nfctinfo status bits into single skb->_nfct (unsigned long) area. For this to work nf_conn addresses must always be aligned at least on an 8 byte boundary since we will need the lower 3bits to store nfctinfo. Conntrack templates are allocated via kmalloc. kbuild test robot reported BUILD_BUG_ON failed: NFCT_INFOMASK >= ARCH_KMALLOC_MINALIGN on v1 of this patchset, so not all platforms meet this requirement. Do manual alignment if needed, the alignment offset is stored in the nf_conn entry protocol area. This works because templates are not handed off to L4 protocol trackers. Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-02-02netfilter: add and use nf_ct_set helperFlorian Westphal
Add a helper to assign a nf_conn entry and the ctinfo bits to an sk_buff. This avoids changing code in followup patch that merges skb->nfct and skb->nfctinfo into skb->_nfct. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-12-04netfilter: add and use nf_ct_netns_get/putFlorian Westphal
currently aliased to try_module_get/_put. Will be changed in next patch when we add functions to make use of ->net argument to store usercount per l3proto tracker. This is needed to avoid registering the conntrack hooks in all netns and later only enable connection tracking in those that need conntrack. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-11-24netfilter: nat: fix crash when conntrack entry is re-usedFlorian Westphal
Stas Nichiporovich reports oops in nf_nat_bysource_cmp(), trying to access nf_conn struct at address 0xffffffffffffff50. This is the result of fetching a null rhash list (struct embedded at offset 176; 0 - 176 gets us ...fff50). The problem is that conntrack entries are allocated from a SLAB_DESTROY_BY_RCU cache, i.e. entries can be free'd and reused on another cpu while nf nat bysource hash access the same conntrack entry. Freeing is fine (we hold rcu read lock); zeroing rhlist_head isn't. -> Move the rhlist struct outside of the memset()-inited area. Fixes: 7c9664351980aaa6a ("netfilter: move nat hlist_head to nf_conn") Reported-by: Stas Nichiporovich <stasn77@gmail.com> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-11-24netfilter: nat: switch to new rhlist interfaceFlorian Westphal
I got offlist bug report about failing connections and high cpu usage. This happens because we hit 'elasticity' checks in rhashtable that refuses bucket list exceeding 16 entries. The nat bysrc hash unfortunately needs to insert distinct objects that share same key and are identical (have same source tuple), this cannot be avoided. Switch to the rhlist interface which is designed for this. The nulls_base is removed here, I don't think its needed: A (unlikely) false positive results in unneeded port clash resolution, a false negative results in packet drop during conntrack confirmation, when we try to insert the duplicate into main conntrack hash table. Tested by adding multiple ip addresses to host, then adding iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE ... and then creating multiple connections, from same source port but different addresses: for i in $(seq 2000 2032);do nc -p 1234 192.168.7.1 $i > /dev/null & done (all of these then get hashed to same bysource slot) Then, to test that nat conflict resultion is working: nc -s 10.0.0.1 -p 1234 192.168.7.1 2000 nc -s 10.0.0.2 -p 1234 192.168.7.1 2000 tcp .. src=10.0.0.1 dst=192.168.7.1 sport=1234 dport=2000 src=192.168.7.1 dst=192.168.7.10 sport=2000 dport=1024 [ASSURED] tcp .. src=10.0.0.2 dst=192.168.7.1 sport=1234 dport=2000 src=192.168.7.1 dst=192.168.7.10 sport=2000 dport=1025 [ASSURED] tcp .. src=192.168.7.10 dst=192.168.7.1 sport=1234 dport=2000 src=192.168.7.1 dst=192.168.7.10 sport=2000 dport=1234 [ASSURED] tcp .. src=192.168.7.10 dst=192.168.7.1 sport=1234 dport=2001 src=192.168.7.1 dst=192.168.7.10 sport=2001 dport=1234 [ASSURED] [..] -> nat altered source ports to 1024 and 1025, respectively. This can also be confirmed on destination host which shows ESTAB 0 0 192.168.7.1:2000 192.168.7.10:1024 ESTAB 0 0 192.168.7.1:2000 192.168.7.10:1025 ESTAB 0 0 192.168.7.1:2000 192.168.7.10:1234 Cc: Herbert Xu <herbert@gondor.apana.org.au> Fixes: 870190a9ec907 ("netfilter: nat: convert nat bysrc hash to rhashtable") Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-08-30netfilter: remove __nf_ct_kill_acct helperFlorian Westphal
After timer removal this just calls nf_ct_delete so remove the __ prefix version and make nf_ct_kill a shorthand for nf_ct_delete. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-08-30netfilter: conntrack: get rid of conntrack timerFlorian Westphal
With stats enabled this eats 80 bytes on x86_64 per nf_conn entry, as Eric Dumazet pointed out during netfilter workshop 2016. Eric also says: "Another reason was the fact that Thomas was about to change max timer range [..]" (500462a9de657f8, 'timers: Switch to a non-cascading wheel'). Remove the timer and use a 32bit jiffies value containing timestamp until entry is valid. During conntrack lookup, even before doing tuple comparision, check the timeout value and evict the entry in case it is too old. The dying bit is used as a synchronization point to avoid races where multiple cpus try to evict the same entry. Because lookup is always lockless, we need to bump the refcnt once when we evict, else we could try to evict already-dead entry that is being recycled. This is the standard/expected way when conntrack entries are destroyed. Followup patches will introduce garbage colliction via work queue and further places where we can reap obsoleted entries (e.g. during netlink dumps), this is needed to avoid expired conntracks from hanging around for too long when lookup rate is low after a busy period. Signed-off-by: Florian Westphal <fw@strlen.de> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-08-18netfilter: conntrack: simplify the code by using nf_conntrack_get_htLiping Zhang
Since commit 64b87639c9cb ("netfilter: conntrack: fix race between nf_conntrack proc read and hash resize") introduce the nf_conntrack_get_ht, so there's no need to check nf_conntrack_generation again and again to get the hash table and hash size. And convert nf_conntrack_get_ht to inline function here. Suggested-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Liping Zhang <liping.zhang@spreadtrum.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-07-24Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-nextDavid S. Miller
Pablo Neira Ayuso says: ==================== Netfilter/IPVS updates for net-next The following patchset contains Netfilter/IPVS updates for net-next, they are: 1) Count pre-established connections as active in "least connection" schedulers such that pre-established connections to avoid overloading backend servers on peak demands, from Michal Kubecek via Simon Horman. 2) Address a race condition when resizing the conntrack table by caching the bucket size when fulling iterating over the hashtable in these three possible scenarios: 1) dump via /proc/net/nf_conntrack, 2) unlinking userspace helper and 3) unlinking custom conntrack timeout. From Liping Zhang. 3) Revisit early_drop() path to perform lockless traversal on conntrack eviction under stress, use del_timer() as synchronization point to avoid two CPUs evicting the same entry, from Florian Westphal. 4) Move NAT hlist_head to nf_conn object, this simplifies the existing NAT extension and it doesn't increase size since recent patches to align nf_conn, from Florian. 5) Use rhashtable for the by-source NAT hashtable, also from Florian. 6) Don't allow --physdev-is-out from OUTPUT chain, just like --physdev-out is not either, from Hangbin Liu. 7) Automagically set on nf_conntrack counters if the user tries to match ct bytes/packets from nftables, from Liping Zhang. 8) Remove possible_net_t fields in nf_tables set objects since we just simply pass the net pointer to the backend set type implementations. 9) Fix possible off-by-one in h323, from Toby DiPasquale. 10) early_drop() may be called from ctnetlink patch, so we must hold rcu read size lock from them too, this amends Florian's patch #3 coming in this batch, from Liping Zhang. 11) Use binary search to validate jump offset in x_tables, this addresses the O(n!) validation that was introduced recently resolve security issues with unpriviledge namespaces, from Florian. 12) Fix reference leak to connlabel in error path of nft_ct, from Zhang. 13) Three updates for nft_log: Fix log prefix leak in error path. Bail out on loglevel larger than debug in nft_log and set on the new NF_LOG_F_COPY_LEN flag when snaplen is specified. Again from Zhang. 14) Allow to filter rule dumps in nf_tables based on table and chain names. 15) Simplify connlabel to always use 128 bits to store labels and get rid of unused function in xt_connlabel, from Florian. 16) Replace set_expect_timeout() by mod_timer() from the h323 conntrack helper, by Gao Feng. 17) Put back x_tables module reference in nft_compat on error, from Liping Zhang. 18) Add a reference count to the x_tables extensions cache in nft_compat, so we can remove them when unused and avoid a crash if the extensions are rmmod, again from Zhang. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-24Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Just several instances of overlapping changes. Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-11netfilter: constify arg to is_dying/confirmedFlorian Westphal
Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-07-11netfilter: nat: convert nat bysrc hash to rhashtableFlorian Westphal
It did use a fixed-size bucket list plus single lock to protect add/del. Unlike the main conntrack table we only need to add and remove keys. Convert it to rhashtable to get table autosizing and per-bucket locking. The maximum number of entries is -- as before -- tied to the number of conntracks so we do not need another upperlimit. The change does not handle rhashtable_remove_fast error, only possible "error" is -ENOENT, and that is something that can happen legitimetely, e.g. because nat module was inserted at a later time and no src manip took place yet. Tested with http-client-benchmark + httpterm with DNAT and SNAT rules in place. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-07-11netfilter: move nat hlist_head to nf_connFlorian Westphal
The nat extension structure is 32bytes in size on x86_64: struct nf_conn_nat { struct hlist_node bysource; /* 0 16 */ struct nf_conn * ct; /* 16 8 */ union nf_conntrack_nat_help help; /* 24 4 */ int masq_index; /* 28 4 */ /* size: 32, cachelines: 1, members: 4 */ /* last cacheline: 32 bytes */ }; The hlist is needed to quickly check for possible tuple collisions when installing a new nat binding. Storing this in the extension area has two drawbacks: 1. We need ct backpointer to get the conntrack struct from the extension. 2. When reallocation of extension area occurs we need to fixup the bysource hash head via hlist_replace_rcu. We can avoid both by placing the hlist_head in nf_conn and place nf_conn in the bysource hash rather than the extenstion. We can also remove the ->move support; no other extension needs it. Moving the entire nat extension into nf_conn would be possible as well but then we have to add yet another callback for deletion from the bysource hash table rather than just using nat extension ->destroy hook for this. nf_conn size doesn't increase due to aligment, followup patch replaces hlist_node with single pointer. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-07-11netfilter: conntrack: simplify early_dropFlorian Westphal
We don't need to acquire the bucket lock during early drop, we can use lockless traveral just like ____nf_conntrack_find. The timer deletion serves as synchronization point, if another cpu attempts to evict same entry, only one will succeed with timer deletion. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-07-08netfilter: nft_ct: fix expiration getterFlorian Westphal
We need to compute timeout.expires - jiffies, not the other way around. Add a helper, another patch can then later change more places in conntrack code where we currently open-code this. Will allow us to only change one place later when we remove per-ct timer. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-06-24netfilter: conntrack: allow increasing bucket size via sysctl tooFlorian Westphal
No need to restrict this to module parameter. We export a copy of the real hash size -- when user alters the value we allocate the new table, copy entries etc before we update the real size to the requested one. This is also needed because the real size is used by concurrent readers and cannot be changed without synchronizing the conntrack generation seqcnt. We only allow changing this value from the initial net namespace. Tested using http-client-benchmark vs. httpterm with concurrent while true;do echo $RANDOM > /proc/sys/net/netfilter/nf_conntrack_buckets done Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-06-23netfilter: move zone info into struct nf_connFlorian Westphal
Curently we store zone information as a conntrack extension. This has one drawback: for every lookup we need to fetch the zone data from the extension area. This change place the zone data directly into the main conntrack object structure and then removes the zone conntrack extension. The zone data is just 4 bytes, it fits into a padding hole before the tuplehash info, so we do not even increase the nf_conn structure size. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-04-25netfilter: conntrack: use get_random_once for conntrack hash seedFlorian Westphal
As earlier commit removed accessed to the hash from other files we can also make it static. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-10-05netfilter: remove dead codeFlavio Leitner
Remove __nf_conntrack_find() from headers. Fixes: dcd93ed4cd1 ("netfilter: nf_conntrack: remove dead code") Signed-off-by: Flavio Leitner <fbl@sysclose.org> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-09-18netfilter: nf_conntrack: Add a struct net parameter to l4_pkt_to_tupleEric W. Biederman
As gre does not have the srckey in the packet gre_pkt_to_tuple needs to perform a lookup in it's per network namespace tables. Pass in the proper network namespace to all pkt_to_tuple implementations to ensure gre (and any similar protocols) can get this right. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-09-05Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nfDavid S. Miller
Conflicts: include/net/netfilter/nf_conntrack.h The conflict was an overlap between changing the type of the zone argument to nf_ct_tmpl_alloc() whilst exporting nf_ct_tmpl_free. Pablo Neira Ayuso says: ==================== Netfilter fixes for net The following patchset contains Netfilter fixes for net, they are: 1) Oneliner to restore maps in nf_tables since we support addressing registers at 32 bits level. 2) Restore previous default behaviour in bridge netfilter when CONFIG_IPV6=n, oneliner from Bernhard Thaler. 3) Out of bound access in ipset hash:net* set types, reported by Dave Jones' KASan utility, patch from Jozsef Kadlecsik. 4) Fix ipset compilation with gcc 4.4.7 related to C99 initialization of unnamed unions, patch from Elad Raz. 5) Add a workaround to address inconsistent endianess in the res_id field of nfnetlink batch messages, reported by Florian Westphal. 6) Fix error paths of CT/synproxy since the conntrack template was moved to use kmalloc, patch from Daniel Borkmann. All of them look good to me to reach 4.2, I can route this to -stable myself too, just let me know what you prefer. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-01netfilter: conntrack: use nf_ct_tmpl_free in CT/synproxy error pathsDaniel Borkmann
Commit 0838aa7fcfcd ("netfilter: fix netns dependencies with conntrack templates") migrated templates to the new allocator api, but forgot to update error paths for them in CT and synproxy to use nf_ct_tmpl_free() instead of nf_conntrack_free(). Due to that, memory is being freed into the wrong kmemcache, but also we drop the per net reference count of ct objects causing an imbalance. In Brad's case, this leads to a wrap-around of net->ct.count and thus lets __nf_conntrack_alloc() refuse to create a new ct object: [ 10.340913] xt_addrtype: ipv6 does not support BROADCAST matching [ 10.810168] nf_conntrack: table full, dropping packet [ 11.917416] r8169 0000:07:00.0 eth0: link up [ 11.917438] IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready [ 12.815902] nf_conntrack: table full, dropping packet [ 15.688561] nf_conntrack: table full, dropping packet [ 15.689365] nf_conntrack: table full, dropping packet [ 15.690169] nf_conntrack: table full, dropping packet [ 15.690967] nf_conntrack: table full, dropping packet [...] With slab debugging, it also reports the wrong kmemcache (kmalloc-512 vs. nf_conntrack_ffffffff81ce75c0) and reports poison overwrites, etc. Thus, to fix the problem, export and use nf_ct_tmpl_free() instead. Fixes: 0838aa7fcfcd ("netfilter: fix netns dependencies with conntrack templates") Reported-by: Brad Jackson <bjackson0971@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-08-11netfilter: nf_conntrack: push zone object into functionsDaniel Borkmann
This patch replaces the zone id which is pushed down into functions with the actual zone object. It's a bigger one-time change, but needed for later on extending zones with a direction parameter, and thus decoupling this additional information from all call-sites. No functional changes in this patch. The default zone becomes a global const object, namely nf_ct_zone_dflt and will be returned directly in various cases, one being, when there's f.e. no zoning support. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-07-20netfilter: fix netns dependencies with conntrack templatesPablo Neira Ayuso
Quoting Daniel Borkmann: "When adding connection tracking template rules to a netns, f.e. to configure netfilter zones, the kernel will endlessly busy-loop as soon as we try to delete the given netns in case there's at least one template present, which is problematic i.e. if there is such bravery that the priviledged user inside the netns is assumed untrusted. Minimal example: ip netns add foo ip netns exec foo iptables -t raw -A PREROUTING -d 1.2.3.4 -j CT --zone 1 ip netns del foo What happens is that when nf_ct_iterate_cleanup() is being called from nf_conntrack_cleanup_net_list() for a provided netns, we always end up with a net->ct.count > 0 and thus jump back to i_see_dead_people. We don't get a soft-lockup as we still have a schedule() point, but the serving CPU spins on 100% from that point onwards. Since templates are normally allocated with nf_conntrack_alloc(), we also bump net->ct.count. The issue why they are not yet nf_ct_put() is because the per netns .exit() handler from x_tables (which would eventually invoke xt_CT's xt_ct_tg_destroy() that drops reference on info->ct) is called in the dependency chain at a *later* point in time than the per netns .exit() handler for the connection tracker. This is clearly a chicken'n'egg problem: after the connection tracker .exit() handler, we've teared down all the connection tracking infrastructure already, so rightfully, xt_ct_tg_destroy() cannot be invoked at a later point in time during the netns cleanup, as that would lead to a use-after-free. At the same time, we cannot make x_tables depend on the connection tracker module, so that the xt_ct_tg_destroy() would be invoked earlier in the cleanup chain." Daniel confirms this has to do with the order in which modules are loaded or having compiled nf_conntrack as modules while x_tables built-in. So we have no guarantees regarding the order in which netns callbacks are executed. Fix this by allocating the templates through kmalloc() from the respective SYNPROXY and CT targets, so they don't depend on the conntrack kmem cache. Then, release then via nf_ct_tmpl_free() from destroy_conntrack(). This branch is marked as unlikely since conntrack templates are rarely allocated and only from the configuration plane path. Note that templates are not kept in any list to avoid further dependencies with nf_conntrack anymore, thus, the tmpl larval list is removed. Reported-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Tested-by: Daniel Borkmann <daniel@iogearbox.net>