summaryrefslogtreecommitdiff
path: root/include/linux/netfilter/nf_conntrack_common.h
AgeCommit message (Collapse)Author
2021-08-30netfilter: refuse insertion if chain has grown too largeFlorian Westphal
Also add a stat counter for this that gets exported both via old /proc interface and ctnetlink. Assuming the old default size of 16536 buckets and max hash occupancy of 64k, this results in 128k insertions (origin+reply), so ~8 entries per chain on average. The revised settings in this series will result in about two entries per bucket on average. This allows a hard-limit ceiling of 64. This is not tunable at the moment, but its possible to either increase nf_conntrack_buckets or decrease nf_conntrack_max to reduce average lengths. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2020-08-28netfilter: conntrack: add clash resolution stat counterFlorian Westphal
There is a misconception about what "insert_failed" means. We increment this even when a clash got resolved, so it might not indicate a problem. Add a dedicated counter for clash resolution and only increment insert_failed if a clash cannot be resolved. For the old /proc interface, export this in place of an older stat that got removed a while back. For ctnetlink, export this with a new attribute. Also correct an outdated comment that implies we add a duplicate tuple -- we only add the (unique) reply direction. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2020-08-28netfilter: conntrack: remove ignore statsFlorian Westphal
This counter increments when nf_conntrack_in sees a packet that already has a conntrack attached or when the packet is marked as UNTRACKED. Neither is an error. The former is normal for loopback traffic. The second happens for certain ICMPv6 packets or when nftables/ip(6)tables rules are in place. In case someone needs to count UNTRACKED packets, or packets that are marked as untracked before conntrack_in this can be done with both nftables and ip(6)tables rules. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
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>
2018-09-17netfilter: remove obsolete need_conntrack stubFlorian Westphal
as of a0ae2562c6c4b27 ("netfilter: conntrack: remove l3proto abstraction") there are no users anymore. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
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>
2016-09-12netfilter: conntrack: remove packet hotpath statsFlorian Westphal
These counters sit in hot path and do show up in perf, this is especially true for 'found' and 'searched' which get incremented for every packet processed. Information like searched=212030105 new=623431 found=333613 delete=623327 does not seem too helpful nowadays: - on busy systems found and searched will overflow every few hours (these are 32bit integers), other more busy ones every few days. - for debugging there are better methods, such as iptables' trace target, the conntrack log sysctls. Nowadays we also have perf tool. This removes packet path stat counters except those that are expected to be 0 (or close to 0) on a normal system, e.g. 'insert_failed' (race happened) or 'invalid' (proto tracker rejects). The insert stat is retained for the ctnetlink case. The found stat is retained for the tuple-is-taken check when NAT has to determine if it needs to pick a different source address. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-09-26netfilter: Remove extern from function prototypesJoe Perches
There are a mix of function prototypes with and without extern in the kernel sources. Standardize on not using extern for function prototypes. Function prototypes don't need to be written with extern. extern is assumed by the compiler. Its use is as unnecessary as using auto to declare automatic/local variables in a block. Signed-off-by: Joe Perches <joe@perches.com>
2012-10-09UAPI: (Scripted) Disintegrate include/linux/netfilterDavid Howells
Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Michael Kerrisk <mtk.manpages@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Dave Jones <davej@redhat.com>
2012-05-08netfilter: nf_conntrack: fix explicit helper attachment and NATPablo Neira Ayuso
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>
2012-01-16netfilter: revert user-space expectation helper supportPablo Neira Ayuso
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>
2011-12-23netfilter: rework user-space expectation helper supportPablo Neira Ayuso
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>
2011-06-06netfilter: add more values to enum ip_conntrack_infoEric Dumazet
Following error is raised (and other similar ones) : net/ipv4/netfilter/nf_nat_standalone.c: In function ‘nf_nat_fn’: net/ipv4/netfilter/nf_nat_standalone.c:119:2: warning: case value ‘4’ not in enumerated type ‘enum ip_conntrack_info’ gcc barfs on adding two enum values and getting a not enumerated result : case IP_CT_RELATED+IP_CT_IS_REPLY: Add missing enum values Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> CC: David Miller <davem@davemloft.net> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2010-10-19netfilter: ctnetlink: add expectation deletion eventsPablo Neira Ayuso
This patch allows to listen to events that inform about expectations destroyed. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Patrick McHardy <kaber@trash.net>
2010-09-28netfilter: ctnetlink: add support for user-space expectation helpersPablo Neira Ayuso
This patch adds the basic infrastructure to support user-space expectation helpers via ctnetlink and the netfilter queuing infrastructure NFQUEUE. Basically, this patch: * adds NF_CT_EXPECT_USERSPACE flag to identify user-space created expectations. I have also added a sanity check in __nf_ct_expect_check() to avoid that kernel-space helpers may create an expectation if the master conntrack has no helper assigned. * adds some branches to check if the master conntrack helper exists, otherwise we skip the code that refers to kernel-space helper such as the local expectation list and the expectation policy. * allows to set the timeout for user-space expectations with no helper assigned. * a list of expectations created from user-space that depends on ctnetlink (if this module is removed, they are deleted). * includes USERSPACE in the /proc output for expectations that have been created by a user-space helper. This patch also modifies ctnetlink to skip including the helper name in the Netlink messages if no kernel-space helper is set (since no user-space expectation has not kernel-space kernel assigned). You can access an example user-space FTP conntrack helper at: http://people.netfilter.org/pablo/userspace-conntrack-helpers/nf-ftp-helper-userspace-POC.tar.bz Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Patrick McHardy <kaber@trash.net>
2010-09-22netfilter: ctnetlink: allow to specify the expectation flagsPablo Neira Ayuso
With this patch, you can specify the expectation flags for user-space created expectations. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Patrick McHardy <kaber@trash.net>
2010-06-08netfilter: nf_conntrack: IPS_UNTRACKED bitEric Dumazet
NOTRACK makes all cpus share a cache line on nf_conntrack_untracked twice per packet. This is bad for performance. __read_mostly annotation is also a bad choice. This patch introduces IPS_UNTRACKED bit so that we can use later a per_cpu untrack structure more easily. A new helper, nf_ct_untracked_get() returns a pointer to nf_conntrack_untracked. Another one, nf_ct_untracked_status_or() is used by nf_nat_init() to add IPS_NAT_DONE_MASK bits to untracked status. nf_ct_is_untracked() prototype is changed to work on a nf_conn pointer. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Patrick McHardy <kaber@trash.net>
2010-04-23netfilter: nf_conntrack: extend with extra stat counterJesper Dangaard Brouer
I suspect an unfortunatly series of events occuring under a DDoS attack, in function __nf_conntrack_find() nf_contrack_core.c. Adding a stats counter to see if the search is restarted too often. Signed-off-by: Jesper Dangaard Brouer <hawk@comx.dk> Signed-off-by: Patrick McHardy <kaber@trash.net>
2010-02-03netfilter: nf_conntrack: support conntrack templatesPatrick McHardy
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: support selective event deliveryPatrick McHardy
Add two masks for conntrack end expectation events to struct nf_conntrack_ecache and use them to filter events. Their default value is "all events" when the event sysctl is on and "no events" when it is off. A following patch will add specific initializations. Expectation events depend on the ecache struct of their master conntrack. Signed-off-by: Patrick McHardy <kaber@trash.net>
2009-11-04net: cleanup include/linuxEric Dumazet
This cleanup patch puts struct/union/enum opening braces, in first line to ease grep games. struct something { becomes : struct something { Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-06-02netfilter: conntrack: remove events flags from userspace exposed filePablo Neira Ayuso
This patch moves the event flags from linux/netfilter/nf_conntrack_common.h to net/netfilter/nf_conntrack_ecache.h. This flags are not of any use from userspace. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2008-07-21netfilter: accounting rework: ct_extend + 64bit counters (v4)Krzysztof Piotr Oledzki
Initially netfilter has had 64bit counters for conntrack-based accounting, but it was changed in 2.6.14 to save memory. Unfortunately in-kernel 64bit counters are still required, for example for "connbytes" extension. However, 64bit counters waste a lot of memory and it was not possible to enable/disable it runtime. This patch: - reimplements accounting with respect to the extension infrastructure, - makes one global version of seq_print_acct() instead of two seq_print_counters(), - makes it possible to enable it at boot time (for CONFIG_SYSCTL/CONFIG_SYSFS=n), - makes it possible to enable/disable it at runtime by sysctl or sysfs, - extends counters from 32bit to 64bit, - renames ip_conntrack_counter -> nf_conn_counter, - enables accounting code unconditionally (no longer depends on CONFIG_NF_CT_ACCT), - set initial accounting enable state based on CONFIG_NF_CT_ACCT - removes buggy IPCT_COUNTER_FILLING event handling. If accounting is enabled newly created connections get additional acct extend. Old connections are not changed as it is not possible to add a ct_extend area to confirmed conntrack. Accounting is performed for all connections with acct extend regardless of a current state of "net.netfilter.nf_conntrack_acct". Signed-off-by: Krzysztof Piotr Oledzki <ole@ans.pl> Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[NETFILTER]: ctnetlink: add support for secmarkPablo Neira Ayuso
This patch adds support for James Morris' connsecmark. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[NETFILTER]: ctnetlink: add support for NAT sequence adjustmentsPablo Neira Ayuso
The combination of NAT and helpers may produce TCP sequence adjustments. In failover setups, this information needs to be replicated in order to achieve a successful recovery of mangled, related connections. This patch is particularly useful for conntrackd, see: http://people.netfilter.org/pablo/conntrack-tools/ Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-09-22[NETFILTER]: conntrack: introduce connection mark eventPablo Neira Ayuso
This patch introduces the mark event. ctnetlink can use this to know if the mark needs to be dumped. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-17[NETFILTER]: conntrack: add fixed timeout flag in connection trackingEric Leblond
Add a flag in a connection status to have a non updated timeout. This permits to have connection that automatically die at a given time. Signed-off-by: Eric Leblond <eric@inl.fr> Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-01-12[NETFILTER] x_tables: Abstraction layer for {ip,ip6,arp}_tablesHarald Welte
This monster-patch tries to do the best job for unifying the data structures and backend interfaces for the three evil clones ip_tables, ip6_tables and arp_tables. In an ideal world we would never have allowed this kind of copy+paste programming... but well, our world isn't (yet?) ideal. o introduce a new x_tables module o {ip,arp,ip6}_tables depend on this x_tables module o registration functions for tables, matches and targets are only wrappers around x_tables provided functions o all matches/targets that are used from ip_tables and ip6_tables are now implemented as xt_FOOBAR.c files and provide module aliases to ipt_FOOBAR and ip6t_FOOBAR o header files for xt_matches are in include/linux/netfilter/, include/linux/netfilter_{ipv4,ipv6} contains compatibility wrappers around the xt_FOOBAR.h headers Based on this patchset we're going to further unify the code, gradually getting rid of all the layer 3 specific assumptions. Signed-off-by: Harald Welte <laforge@netfilter.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-11-09[NETFILTER]: Add nf_conntrack subsystem.Yasuyuki Kozakai
The existing connection tracking subsystem in netfilter can only handle ipv4. There were basically two choices present to add connection tracking support for ipv6. We could either duplicate all of the ipv4 connection tracking code into an ipv6 counterpart, or (the choice taken by these patches) we could design a generic layer that could handle both ipv4 and ipv6 and thus requiring only one sub-protocol (TCP, UDP, etc.) connection tracking helper module to be written. In fact nf_conntrack is capable of working with any layer 3 protocol. The existing ipv4 specific conntrack code could also not deal with the pecularities of doing connection tracking on ipv6, which is also cured here. For example, these issues include: 1) ICMPv6 handling, which is used for neighbour discovery in ipv6 thus some messages such as these should not participate in connection tracking since effectively they are like ARP messages 2) fragmentation must be handled differently in ipv6, because the simplistic "defrag, connection track and NAT, refrag" (which the existing ipv4 connection tracking does) approach simply isn't feasible in ipv6 3) ipv6 extension header parsing must occur at the correct spots before and after connection tracking decisions, and there were no provisions for this in the existing connection tracking design 4) ipv6 has no need for stateful NAT The ipv4 specific conntrack layer is kept around, until all of the ipv4 specific conntrack helpers are ported over to nf_conntrack and it is feature complete. Once that occurs, the old conntrack stuff will get placed into the feature-removal-schedule and we will fully kill it off 6 months later. Signed-off-by: Yasuyuki Kozakai <yasuyuki.kozakai@toshiba.co.jp> Signed-off-by: Harald Welte <laforge@netfilter.org> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>