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* netfilter: conntrack: remove pr_debug callsites from tcp trackerFlorian Westphal2022-05-161-48/+4
| | | | | | | | | | | | | They are either obsolete or useless. Those in the normal processing path cannot be enabled on a production system; they generate too much noise. One pr_debug call resides in an error path and does provide useful info, merge it with the existing nf_log_invalid(). Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* netfilter: nf_conntrack_tcp: re-init for syn packets onlyFlorian Westphal2022-04-271-15/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Jaco Kroon reported tcp problems that Eric Dumazet and Neal Cardwell pinpointed to nf_conntrack tcp_in_window() bug. tcp trace shows following sequence: I > R Flags [S], seq 3451342529, win 62580, options [.. tfo [|tcp]> R > I Flags [S.], seq 2699962254, ack 3451342530, win 65535, options [..] R > I Flags [P.], seq 1:89, ack 1, [..] Note 3rd ACK is from responder to initiator so following branch is taken: } else if (((state->state == TCP_CONNTRACK_SYN_SENT && dir == IP_CT_DIR_ORIGINAL) || (state->state == TCP_CONNTRACK_SYN_RECV && dir == IP_CT_DIR_REPLY)) && after(end, sender->td_end)) { ... because state == TCP_CONNTRACK_SYN_RECV and dir is REPLY. This causes the scaling factor to be reset to 0: window scale option is only present in syn(ack) packets. This in turn makes nf_conntrack mark valid packets as out-of-window. This was always broken, it exists even in original commit where window tracking was added to ip_conntrack (nf_conntrack predecessor) in 2.6.9-rc1 kernel. Restrict to 'tcph->syn', just like the 3rd condtional added in commit 82b72cb94666 ("netfilter: conntrack: re-init state for retransmitted syn-ack"). Upon closer look, those conditionals/branches can be merged: Because earlier checks prevent syn-ack from showing up in original direction, the 'dir' checks in the conditional quoted above are redundant, remove them. Return early for pure syn retransmitted in reply direction (simultaneous open). Fixes: 9fb9cbb1082d ("[NETFILTER]: Add nf_conntrack subsystem.") Reported-by: Jaco Kroon <jaco@uls.co.za> Signed-off-by: Florian Westphal <fw@strlen.de> Acked-by: Jozsef Kadlecsik <kadlec@netfilter.org> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* netfilter: nf_conntrack_tcp: preserve liberal flag in tcp optionsPablo Neira Ayuso2022-03-241-4/+13
| | | | | | | | | | | | | | | Do not reset IP_CT_TCP_FLAG_BE_LIBERAL flag in out-of-sync scenarios coming before the TCP window tracking, otherwise such connections will fail in the window check. Update tcp_options() to leave this flag in place and add a new helper function to reset the tcp window state. Based on patch from Sven Auhagen. Fixes: c4832c7bbc3f ("netfilter: nf_ct_tcp: improve out-of-sync situation in TCP tracking") Tested-by: Sven Auhagen <sven.auhagen@voleatech.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* netfilter: conntrack: re-init state for retransmitted syn-ackFlorian Westphal2022-02-041-0/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | TCP conntrack assumes that a syn-ack retransmit is identical to the previous syn-ack. This isn't correct and causes stuck 3whs in some more esoteric scenarios. tcpdump to illustrate the problem: client > server: Flags [S] seq 1365731894, win 29200, [mss 1460,sackOK,TS val 2083035583 ecr 0,wscale 7] server > client: Flags [S.] seq 145824453, ack 643160523, win 65535, [mss 8952,wscale 5,TS val 3215367629 ecr 2082921663] Note the invalid/outdated synack ack number. Conntrack marks this syn-ack as out-of-window/invalid, but it did initialize the reply direction parameters based on this packets content. client > server: Flags [S] seq 1365731894, win 29200, [mss 1460,sackOK,TS val 2083036623 ecr 0,wscale 7] ... retransmit... server > client: Flags [S.], seq 145824453, ack 643160523, win 65535, [mss 8952,wscale 5,TS val 3215368644 ecr 2082921663] and another bogus synack. This repeats, then client re-uses for a new attempt: client > server: Flags [S], seq 2375731741, win 29200, [mss 1460,sackOK,TS val 2083100223 ecr 0,wscale 7] server > client: Flags [S.], seq 145824453, ack 643160523, win 65535, [mss 8952,wscale 5,TS val 3215430754 ecr 2082921663] ... but still gets a invalid syn-ack. This repeats until: server > client: Flags [S.], seq 145824453, ack 643160523, win 65535, [mss 8952,wscale 5,TS val 3215437785 ecr 2082921663] server > client: Flags [R.], seq 145824454, ack 643160523, win 65535, [mss 8952,wscale 5,TS val 3215443451 ecr 2082921663] client > server: Flags [S], seq 2375731741, win 29200, [mss 1460,sackOK,TS val 2083115583 ecr 0,wscale 7] server > client: Flags [S.], seq 162602410, ack 2375731742, win 65535, [mss 8952,wscale 5,TS val 3215445754 ecr 2083115583] This syn-ack has the correct ack number, but conntrack flags it as invalid: The internal state was created from the first syn-ack seen so the sequence number of the syn-ack is treated as being outside of the announced window. Don't assume that retransmitted syn-ack is identical to previous one. Treat it like the first syn-ack and reinit state. Signed-off-by: Florian Westphal <fw@strlen.de> Acked-by: Jozsef Kadlecsik <kadlec@netfilter.org> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* netfilter: conntrack: move synack init code to helperFlorian Westphal2022-02-041-18/+29
| | | | | | | | | | | | It seems more readable to use a common helper in the followup fix rather than copypaste or goto. No functional change intended. The function is only called for syn-ack or syn in repy direction in case of simultaneous open. Signed-off-by: Florian Westphal <fw@strlen.de> Acked-by: Jozsef Kadlecsik <kadlec@netfilter.org> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* netfilter: conntrack: remove offload_pickup sysctl againFlorian Westphal2021-08-061-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | These two sysctls were added because the hardcoded defaults (2 minutes, tcp, 30 seconds, udp) turned out to be too low for some setups. They appeared in 5.14-rc1 so it should be fine to remove it again. Marcelo convinced me that there should be no difference between a flow that was offloaded vs. a flow that was not wrt. timeout handling. Thus the default is changed to those for TCP established and UDP stream, 5 days and 120 seconds, respectively. Marcelo also suggested to account for the timeout value used for the offloading, this avoids increase beyond the value in the conntrack-sysctl and will also instantly expire the conntrack entry with altered sysctls. Example: nf_conntrack_udp_timeout_stream=60 nf_flowtable_udp_timeout=60 This will remove offloaded udp flows after one minute, rather than two. An earlier version of this patch also cleared the ASSURED bit to allow nf_conntrack to evict the entry via early_drop (i.e., table full). However, it looks like we can safely assume that connection timed out via HW is still in established state, so this isn't needed. Quoting Oz: [..] the hardware sends all packets with a set FIN flags to sw. [..] Connections that are aged in hardware are expected to be in the established state. In case it turns out that back-to-sw-path transition can occur for 'dodgy' connections too (e.g., one side disappeared while software-path would have been in RETRANS timeout), we can adjust this later. Cc: Oz Shlomo <ozsh@nvidia.com> Cc: Paul Blakey <paulb@nvidia.com> Suggested-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: Florian Westphal <fw@strlen.de> Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Reviewed-by: Oz Shlomo <ozsh@nvidia.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* netfilter: conntrack: add new sysctl to disable RST checkAli Abdallah2021-07-061-1/+5
| | | | | | | | | This patch adds a new sysctl tcp_ignore_invalid_rst to disable marking out of segments RSTs as INVALID. Signed-off-by: Ali Abdallah <aabdallah@suse.de> Acked-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* netfilter: conntrack: improve RST handling when tuple is re-usedAli Abdallah2021-07-061-17/+36
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If we receive a SYN packet in original direction on an existing connection tracking entry, we let this SYN through because conntrack might be out-of-sync. Conntrack gets back in sync when server responds with SYN/ACK and state gets updated accordingly. However, if server replies with RST, this packet might be marked as INVALID because td_maxack value reflects the *old* conntrack state and not the state of the originator of the RST. Avoid td_maxack-based checks if previous packet was a SYN. Unfortunately that is not be enough: an out of order ACK in original direction updates last_index, so we still end up marking valid RST. Thus disable the sequence check when we are not in established state and the received RST has a sequence of 0. Because marking RSTs as invalid usually leads to unwanted timeouts, also skip RST sequence checks if a conntrack entry is already closing. Such entries can already be evicted via GC in case the table is full. Co-developed-by: Florian Westphal <fw@strlen.de> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Ali Abdallah <aabdallah@suse.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* netfilter: conntrack: do not renew entry stuck in tcp SYN_SENT stateFlorian Westphal2021-07-021-0/+10
| | | | | | | | | | | | | | | | | | | | | | | | | Consider: client -----> conntrack ---> Host client sends a SYN, but $Host is unreachable/silent. Client eventually gives up and the conntrack entry will time out. However, if the client is restarted with same addr/port pair, it may prevent the conntrack entry from timing out. This is noticeable when the existing conntrack entry has no NAT transformation or an outdated one and port reuse happens either on client or due to a NAT middlebox. This change prevents refresh of the timeout for SYN retransmits, so entry is going away after nf_conntrack_tcp_timeout_syn_sent seconds (default: 60). Entry will be re-created on next connection attempt, but then nat rules will be evaluated again. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* netfilter: conntrack: pass hook state to log functionsFlorian Westphal2021-06-181-11/+12
| | | | | | | | | | | The packet logger backend is unable to provide the incoming (or outgoing) interface name because that information isn't available. Pass the hook state, it contains the network namespace, the protocol family, the network interfaces and other things. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* netfilter: conntrack: Introduce tcp offload timeout configurationOz Shlomo2021-06-071-0/+5
| | | | | | | | | | | | | | | | TCP connections may be offloaded from nf conntrack to nf flow table. Offloaded connections are aged after 30 seconds of inactivity. Once aged, ownership is returned to conntrack with a hard coded pickup time of 120 seconds, after which the connection may be deleted. eted. The current aging intervals may be too aggressive for some users. Provide users with the ability to control the nf flow table offload aging and pickup time intervals via sysctl parameter as a pre-step for configuring the nf flow table GC timeout intervals. Signed-off-by: Oz Shlomo <ozsh@nvidia.com> Reviewed-by: Paul Blakey <paulb@nvidia.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* netfilter: remove BUG_ON() after skb_header_pointer()Pablo Neira Ayuso2021-05-051-2/+4
| | | | | | | | | Several conntrack helpers and the TCP tracker assume that skb_header_pointer() never fails based on upfront header validation. Even if this should not ever happen, BUG_ON() is a too drastic measure, remove them. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* netfilter: conntrack: convert sysctls to u8Florian Westphal2021-04-131-17/+17
| | | | | | | | | | | | | log_invalid sysctl allows values of 0 to 255 inclusive so we no longer need a range check: the min/max values can be removed. This also removes all member variables that were moved to net_generic data in previous patches. This reduces size of netns_ct struct by one cache line. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* netfilter: conntrack: avoid misleading 'invalid' in log messageFlorian Westphal2021-02-281-2/+4
| | | | | | | | | | The packet is not flagged as invalid: conntrack will accept it and its associated with the conntrack entry. This happens e.g. when receiving a retransmitted SYN in SYN_RECV state. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* netfilter: ctnetlink: add timeout and protoinfo to destroy eventsFlorian Westphal2020-12-121-4/+9
| | | | | | | | | | | | | | | | | DESTROY events do not include the remaining timeout. Add the timeout if the entry was removed explicitly. This can happen when a conntrack gets deleted prematurely, e.g. due to a tcp reset, module removal, netdev notifier (nat/masquerade device went down), ctnetlink and so on. Add the protocol state too for the destroy message to check for abnormal state on connection termination. Joint work with Pablo. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* net: openvswitch: Be liberal in tcp conntrack.Numan Siddique2020-11-201-6/+0
| | | | | | | | | | | | | | | | | There is no easy way to distinguish if a conntracked tcp packet is marked invalid because of tcp_in_window() check error or because it doesn't belong to an existing connection. With this patch, openvswitch sets liberal tcp flag for the established sessions so that out of window packets are not marked invalid. A helper function - nf_ct_set_tcp_be_liberal(nf_conn) is added which sets this flag for both the directions of the nf_conn. Suggested-by: Florian Westphal <fw@strlen.de> Signed-off-by: Numan Siddique <nusiddiq@redhat.com> Acked-by: Florian Westphal <fw@strlen.de> Link: https://lore.kernel.org/r/20201116130126.3065077-1-nusiddiq@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* netfilter: conntrack: connection timeout after re-registerFrancesco Ruggeri2020-10-201-6/+13
| | | | | | | | | | | | | | | | | | | If the first packet conntrack sees after a re-register is an outgoing keepalive packet with no data (SEG.SEQ = SND.NXT-1), td_end is set to SND.NXT-1. When the peer correctly acknowledges SND.NXT, tcp_in_window fails check III (Upper bound for valid (s)ack: sack <= receiver.td_end) and returns false, which cascades into nf_conntrack_in setting skb->_nfct = 0 and in later conntrack iptables rules not matching. In cases where iptables are dropping packets that do not match conntrack rules this can result in idle tcp connections to time out. v2: adjust td_end when getting the reply rather than when sending out the keepalive packet. Fixes: f94e63801ab2 ("netfilter: conntrack: reset tcp maxwin on re-register") Signed-off-by: Francesco Ruggeri <fruggeri@arista.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* netfilter: delete repeated wordsRandy Dunlap2020-08-281-1/+1
| | | | | | | | Drop duplicated words in net/netfilter/ and net/ipv4/netfilter/. Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Reviewed-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* netfilter: Use fallthrough pseudo-keywordGustavo A. R. Silva2020-07-221-1/+1
| | | | | | | | | | | Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/latest/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* netfilter: remove unnecessary spacesyangxingwu2019-08-131-1/+1
| | | | | | | This patch removes extra spaces. Signed-off-by: yangxingwu <xingwu.yang@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* netfilter: conntrack: always store window size un-scaledFlorian Westphal2019-07-161-3/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Jakub Jankowski reported following oddity: After 3 way handshake completes, timeout of new connection is set to max_retrans (300s) instead of established (5 days). shortened excerpt from pcap provided: 25.070622 IP (flags [DF], proto TCP (6), length 52) 10.8.5.4.1025 > 10.8.1.2.80: Flags [S], seq 11, win 64240, [wscale 8] 26.070462 IP (flags [DF], proto TCP (6), length 48) 10.8.1.2.80 > 10.8.5.4.1025: Flags [S.], seq 82, ack 12, win 65535, [wscale 3] 27.070449 IP (flags [DF], proto TCP (6), length 40) 10.8.5.4.1025 > 10.8.1.2.80: Flags [.], ack 83, win 512, length 0 Turns out the last_win is of u16 type, but we store the scaled value: 512 << 8 (== 0x20000) becomes 0 window. The Fixes tag is not correct, as the bug has existed forever, but without that change all that this causes might cause is to mistake a window update (to-nonzero-from-zero) for a retransmit. Fixes: fbcd253d2448b8 ("netfilter: conntrack: lower timeout to RETRANS seconds if window is 0") Reported-by: Jakub Jankowski <shasta@toxcorp.com> Tested-by: Jakub Jankowski <shasta@toxcorp.com> Signed-off-by: Florian Westphal <fw@strlen.de> Acked-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-nextPablo Neira Ayuso2019-06-251-4/+1
|\ | | | | | | | | | | | | | | | | Resolve conflict between d2912cb15bdd ("treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500") removing the GPL disclaimer and fe03d4745675 ("Update my email address") which updates Jozsef Kadlecsik's email. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
| * treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500Thomas Gleixner2019-06-191-4/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Based on 2 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation # extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 4122 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Enrico Weigelt <info@metux.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | Update my email addressJozsef Kadlecsik2019-06-101-1/+1
|/ | | | | | | | | It's better to use my kadlec@netfilter.org email address in the source code. I might not be able to use kadlec@blackhole.kfki.hu in the future. Signed-off-by: Jozsef Kadlecsik <kadlec@netfilter.org> Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
* netlink: make validation more configurable for future strictnessJohannes Berg2019-04-271-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We currently have two levels of strict validation: 1) liberal (default) - undefined (type >= max) & NLA_UNSPEC attributes accepted - attribute length >= expected accepted - garbage at end of message accepted 2) strict (opt-in) - NLA_UNSPEC attributes accepted - attribute length >= expected accepted Split out parsing strictness into four different options: * TRAILING - check that there's no trailing data after parsing attributes (in message or nested) * MAXTYPE - reject attrs > max known type * UNSPEC - reject attributes with NLA_UNSPEC policy entries * STRICT_ATTRS - strictly validate attribute size The default for future things should be *everything*. The current *_strict() is a combination of TRAILING and MAXTYPE, and is renamed to _deprecated_strict(). The current regular parsing has none of this, and is renamed to *_parse_deprecated(). Additionally it allows us to selectively set one of the new flags even on old policies. Notably, the UNSPEC flag could be useful in this case, since it can be arranged (by filling in the policy) to not be an incompatible userspace ABI change, but would then going forward prevent forgetting attribute entries. Similar can apply to the POLICY flag. We end up with the following renames: * nla_parse -> nla_parse_deprecated * nla_parse_strict -> nla_parse_deprecated_strict * nlmsg_parse -> nlmsg_parse_deprecated * nlmsg_parse_strict -> nlmsg_parse_deprecated_strict * nla_parse_nested -> nla_parse_nested_deprecated * nla_validate_nested -> nla_validate_nested_deprecated Using spatch, of course: @@ expression TB, MAX, HEAD, LEN, POL, EXT; @@ -nla_parse(TB, MAX, HEAD, LEN, POL, EXT) +nla_parse_deprecated(TB, MAX, HEAD, LEN, POL, EXT) @@ expression NLH, HDRLEN, TB, MAX, POL, EXT; @@ -nlmsg_parse(NLH, HDRLEN, TB, MAX, POL, EXT) +nlmsg_parse_deprecated(NLH, HDRLEN, TB, MAX, POL, EXT) @@ expression NLH, HDRLEN, TB, MAX, POL, EXT; @@ -nlmsg_parse_strict(NLH, HDRLEN, TB, MAX, POL, EXT) +nlmsg_parse_deprecated_strict(NLH, HDRLEN, TB, MAX, POL, EXT) @@ expression TB, MAX, NLA, POL, EXT; @@ -nla_parse_nested(TB, MAX, NLA, POL, EXT) +nla_parse_nested_deprecated(TB, MAX, NLA, POL, EXT) @@ expression START, MAX, POL, EXT; @@ -nla_validate_nested(START, MAX, POL, EXT) +nla_validate_nested_deprecated(START, MAX, POL, EXT) @@ expression NLH, HDRLEN, MAX, POL, EXT; @@ -nlmsg_validate(NLH, HDRLEN, MAX, POL, EXT) +nlmsg_validate_deprecated(NLH, HDRLEN, MAX, POL, EXT) For this patch, don't actually add the strict, non-renamed versions yet so that it breaks compile if I get it wrong. Also, while at it, make nla_validate and nla_parse go down to a common __nla_validate_parse() function to avoid code duplication. Ultimately, this allows us to have very strict validation for every new caller of nla_parse()/nlmsg_parse() etc as re-introduced in the next patch, while existing things will continue to work as is. In effect then, this adds fully strict validation for any new command. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* netlink: make nla_nest_start() add NLA_F_NESTED flagMichal Kubecek2019-04-271-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Even if the NLA_F_NESTED flag was introduced more than 11 years ago, most netlink based interfaces (including recently added ones) are still not setting it in kernel generated messages. Without the flag, message parsers not aware of attribute semantics (e.g. wireshark dissector or libmnl's mnl_nlmsg_fprintf()) cannot recognize nested attributes and won't display the structure of their contents. Unfortunately we cannot just add the flag everywhere as there may be userspace applications which check nlattr::nla_type directly rather than through a helper masking out the flags. Therefore the patch renames nla_nest_start() to nla_nest_start_noflag() and introduces nla_nest_start() as a wrapper adding NLA_F_NESTED. The calls which add NLA_F_NESTED manually are rewritten to use nla_nest_start(). Except for changes in include/net/netlink.h, the patch was generated using this semantic patch: @@ expression E1, E2; @@ -nla_nest_start(E1, E2) +nla_nest_start_noflag(E1, E2) @@ expression E1, E2; @@ -nla_nest_start_noflag(E1, E2 | NLA_F_NESTED) +nla_nest_start(E1, E2) Signed-off-by: Michal Kubecek <mkubecek@suse.cz> Acked-by: Jiri Pirko <jiri@mellanox.com> Acked-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* netfilter: conntrack: tcp: only close if RST matches exact sequenceFlorian Westphal2019-03-011-10/+40
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | TCP resets cause instant transition from established to closed state provided the reset is in-window. Endpoints that implement RFC 5961 require resets to match the next expected sequence number. RST segments that are in-window (but that do not match RCV.NXT) are ignored, and a "challenge ACK" is sent back. Main problem for conntrack is that its a middlebox, i.e. whereas an end host might have ACK'd SEQ (and would thus accept an RST with this sequence number), conntrack might not have seen this ACK (yet). Therefore we can't simply flag RSTs with non-exact match as invalid. This updates RST processing as follows: 1. If the connection is in a state other than ESTABLISHED, nothing is changed, RST is subject to normal in-window check. 2. If the RSTs sequence number either matches exactly RCV.NXT, connection state moves to CLOSE. 3. The same applies if the RST sequence number aligns with a previous packet in the same direction. In all other cases, the connection remains in ESTABLISHED state. If the normal-in-window check passes, the timeout will be lowered to that of CLOSE. If the peer sends a challenge ack, connection timeout will be reset. If the challenge ACK triggers another RST (RST was valid after all), this 2nd RST will match expected sequence and conntrack state changes to CLOSE. If no challenge ACK is received, the connection will time out after CLOSE seconds (10 seconds by default), just like without this patch. Packetdrill test case: 0.000 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3 0.000 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0 0.000 bind(3, ..., ...) = 0 0.000 listen(3, 1) = 0 0.100 < S 0:0(0) win 32792 <mss 1460,sackOK,nop,nop,nop,wscale 7> 0.100 > S. 0:0(0) ack 1 win 64240 <mss 1460,nop,nop,sackOK,nop,wscale 7> 0.200 < . 1:1(0) ack 1 win 257 0.200 accept(3, ..., ...) = 4 // Receive a segment. 0.210 < P. 1:1001(1000) ack 1 win 46 0.210 > . 1:1(0) ack 1001 // Application writes 1000 bytes. 0.250 write(4, ..., 1000) = 1000 0.250 > P. 1:1001(1000) ack 1001 // First reset, old sequence. Conntrack (correctly) considers this // invalid due to failed window validation (regardless of this patch). 0.260 < R 2:2(0) ack 1001 win 260 // 2nd reset, but too far ahead sequence. Same: correctly handled // as invalid. 0.270 < R 99990001:99990001(0) ack 1001 win 260 // in-window, but not exact sequence. // Current Linux kernels might reply with a challenge ack, and do not // remove connection. // Without this patch, conntrack state moves to CLOSE. // With patch, timeout is lowered like CLOSE, but connection stays // in ESTABLISHED state. 0.280 < R 1010:1010(0) ack 1001 win 260 // Expect challenge ACK 0.281 > . 1001:1001(0) ack 1001 win 501 // With or without this patch, RST will cause connection // to move to CLOSE (sequence number matches) // 0.282 < R 1001:1001(0) ack 1001 win 260 // ACK 0.300 < . 1001:1001(0) ack 1001 win 257 // more data could be exchanged here, connection // is still established // Client closes the connection. 0.610 < F. 1001:1001(0) ack 1001 win 260 0.650 > . 1001:1001(0) ack 1002 // Close the connection without reading outstanding data 0.700 close(4) = 0 // so one more reset. Will be deemed acceptable with patch as well: // connection is already closing. 0.701 > R. 1001:1001(0) ack 1002 win 501 // End packetdrill test case. With patch, this generates following conntrack events: [NEW] 120 SYN_SENT src=10.0.2.1 dst=10.0.0.1 sport=5437 dport=80 [UNREPLIED] [UPDATE] 60 SYN_RECV src=10.0.2.1 dst=10.0.0.1 sport=5437 dport=80 [UPDATE] 432000 ESTABLISHED src=10.0.2.1 dst=10.0.0.1 sport=5437 dport=80 [ASSURED] [UPDATE] 120 FIN_WAIT src=10.0.2.1 dst=10.0.0.1 sport=5437 dport=80 [ASSURED] [UPDATE] 60 CLOSE_WAIT src=10.0.2.1 dst=10.0.0.1 sport=5437 dport=80 [ASSURED] [UPDATE] 10 CLOSE src=10.0.2.1 dst=10.0.0.1 sport=5437 dport=80 [ASSURED] Without patch, first RST moves connection to close, whereas socket state does not change until FIN is received. [NEW] 120 SYN_SENT src=10.0.2.1 dst=10.0.0.1 sport=5141 dport=80 [UNREPLIED] [UPDATE] 60 SYN_RECV src=10.0.2.1 dst=10.0.0.1 sport=5141 dport=80 [UPDATE] 432000 ESTABLISHED src=10.0.2.1 dst=10.0.0.1 sport=5141 dport=80 [ASSURED] [UPDATE] 10 CLOSE src=10.0.2.1 dst=10.0.0.1 sport=5141 dport=80 [ASSURED] Cc: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* netfilter: conntrack: remove l4proto init and get_net callbacksFlorian Westphal2019-01-181-24/+11
| | | | | | | | | Those were needed we still had modular trackers. As we don't have those anymore, prefer direct calls and remove all the (un)register infrastructure associated with this. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* netfilter: conntrack: unify sysctl handlingFlorian Westphal2019-01-181-115/+1
| | | | | | | | | | | | | | | | Due to historical reasons, all l4 trackers register their own sysctls. This leads to copy&pasted boilerplate code, that does exactly same thing, just with different data structure. Place all of this in a single file. This allows to remove the various ctl_table pointers from the ct_netns structure and reduces overall code size. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* netfilter: conntrack: handle builtin l4proto packet functions via direct callsFlorian Westphal2019-01-181-6/+5
| | | | | | | | | | The l4 protocol trackers are invoked via indirect call: l4proto->packet(). With one exception (gre), all l4trackers are builtin, so we can make .packet optional and use a direct call for most protocols. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* netfilter: conntrack: add nf_{tcp,udp,sctp,icmp,dccp,icmpv6,generic}_pernet()Pablo Neira Ayuso2018-11-031-10/+5
| | | | | | | Expose these functions to access conntrack protocol tracker netns area, nfnetlink_cttimeout needs this. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-nextDavid S. Miller2018-10-081-147/+104
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pablo Neira Ayuso says: ==================== Netfilter updates for net-next The following patchset contains Netfilter updates for your net-next tree: 1) Support for matching on ipsec policy already set in the route, from Florian Westphal. 2) Split set destruction into deactivate and destroy phase to make it fit better into the transaction infrastructure, also from Florian. This includes a patch to warn on imbalance when setting the new activate and deactivate interfaces. 3) Release transaction list from the workqueue to remove expensive synchronize_rcu() from configuration plane path. This speeds up configuration plane quite a bit. From Florian Westphal. 4) Add new xfrm/ipsec extension, this new extension allows you to match for ipsec tunnel keys such as source and destination address, spi and reqid. From Máté Eckl and Florian Westphal. 5) Add secmark support, this includes connsecmark too, patches from Christian Gottsche. 6) Allow to specify remaining bytes in xt_quota, from Chenbo Feng. One follow up patch to calm a clang warning for this one, from Nathan Chancellor. 7) Flush conntrack entries based on layer 3 family, from Kristian Evensen. 8) New revision for cgroups2 to shrink the path field. 9) Get rid of obsolete need_conntrack(), as a result from recent demodularization works. 10) Use WARN_ON instead of BUG_ON, from Florian Westphal. 11) Unused exported symbol in nf_nat_ipv4_fn(), from Florian. 12) Remove superfluous check for timeout netlink parser and dump functions in layer 4 conntrack helpers. 13) Unnecessary redundant rcu read side locks in NAT redirect, from Taehee Yoo. 14) Pass nf_hook_state structure to error handlers, patch from Florian Westphal. 15) Remove ->new() interface from layer 4 protocol trackers. Place them in the ->packet() interface. From Florian. 16) Place conntrack ->error() handling in the ->packet() interface. Patches from Florian Westphal. 17) Remove unused parameter in the pernet initialization path, also from Florian. 18) Remove additional parameter to specify layer 3 protocol when looking up for protocol tracker. From Florian. 19) Shrink array of layer 4 protocol trackers, from Florian. 20) Check for linear skb only once from the ALG NAT mangling codebase, from Taehee Yoo. 21) Use rhashtable_walk_enter() instead of deprecated rhashtable_walk_init(), also from Taehee. 22) No need to flush all conntracks when only one single address is gone, from Tan Hu. 23) Remove redundant check for NAT flags in flowtable code, from Taehee Yoo. 24) Use rhashtable_lookup() instead of rhashtable_lookup_fast() from netfilter codebase, since rcu read lock side is already assumed in this path. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
| * netfilter: conntrack: remove l3->l4 mapping informationFlorian Westphal2018-09-201-36/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | l4 protocols are demuxed by l3num, l4num pair. However, almost all l4 trackers are l3 agnostic. Only exceptions are: - gre, icmp (ipv4 only) - icmpv6 (ipv6 only) This commit gets rid of the l3 mapping, l4 trackers can now be looked up by their IPPROTO_XXX value alone, which gets rid of the additional l3 indirection. For icmp, ipcmp6 and gre, add a check on state->pf and return -NF_ACCEPT in case we're asked to track e.g. icmpv6-in-ipv4, this seems more fitting than using the generic tracker. Additionally we can kill the 2nd l4proto definitions that were needed for v4/v6 split -- they are now the same so we can use single l4proto struct for each protocol, rather than two. The EXPORT_SYMBOLs can be removed as all these object files are part of nf_conntrack with no external references. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
| * netfilter: conntrack: remove unused proto arg from netns init functionsFlorian Westphal2018-09-201-1/+1
| | | | | | | | | | | | | | | | Its unused, next patch will remove l4proto->l3proto number to simplify l4 protocol demuxer lookup. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
| * netfilter: conntrack: avoid using ->error callback if possibleFlorian Westphal2018-09-201-20/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The error() handler gets called before allocating or looking up a connection tracking entry. We can instead use direct calls from the ->packet() handlers which get invoked for every packet anyway. Only exceptions are icmp and icmpv6, these two special cases will be handled in the next patch. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
| * netfilter: conntrack: deconstify packet callback skb pointerFlorian Westphal2018-09-201-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Only two protocols need the ->error() function: icmp and icmpv6. This is because icmp error mssages might be RELATED to an existing connection (e.g. PMTUD, port unreachable and the like), and their ->error() handlers do this. The error callback is already optional, so remove it for udp and call them from ->packet() instead. As the error() callback can call checksum functions that write to skb->csum*, the const qualifier has to be removed as well. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
| * netfilter: conntrack: remove the l4proto->new() functionFlorian Westphal2018-09-201-79/+77
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ->new() gets invoked after ->error() and before ->packet() if a conntrack lookup has found no result for the tuple. We can fold it into ->packet() -- the packet() implementations can check if the conntrack is confirmed (new) or not (already in hash). If its unconfirmed, the conntrack isn't in the hash yet so current skb created a new conntrack entry. Only relevant side effect -- if packet() doesn't return NF_ACCEPT but -NF_ACCEPT (or drop), while the conntrack was just created, then the newly allocated conntrack is freed right away, rather than not created in the first place. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
| * netfilter: conntrack: pass nf_hook_state to packet and error handlersFlorian Westphal2018-09-201-13/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | nf_hook_state contains all the hook meta-information: netns, protocol family, hook location, and so on. Instead of only passing selected information, pass a pointer to entire structure. This will allow to merge the error and the packet handlers and remove the ->new() function in followup patches. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* | netfilter: conntrack: get rid of double sizeofzhong jiang2018-09-201-2/+2
|/ | | | | | | | | | | | sizeof(sizeof()) is quite strange and does not seem to be what is wanted here. The issue is detected with the help of Coccinelle. Fixes: 39215846740a ("netfilter: conntrack: remove nlattr_size pointer from l4proto trackers") Signed-off-by: zhong jiang <zhongjiang@huawei.com> Acked-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* netfilter: conntrack: timeout interface depend on CONFIG_NF_CONNTRACK_TIMEOUTPablo Neira Ayuso2018-09-111-6/+6
| | | | | | | | | | | | | | | Now that cttimeout support for nft_ct is in place, these should depend on CONFIG_NF_CONNTRACK_TIMEOUT otherwise we can crash when dumping the policy if this option is not enabled. [ 71.600121] BUG: unable to handle kernel NULL pointer dereference at 0000000000000000 [...] [ 71.600141] CPU: 3 PID: 7612 Comm: nft Not tainted 4.18.0+ #246 [...] [ 71.600188] Call Trace: [ 71.600201] ? nft_ct_timeout_obj_dump+0xc6/0xf0 [nft_ct] Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* netfilter: conntrack: place 'new' timeout in first location tooFlorian Westphal2018-08-291-0/+7
| | | | | | | | | | | | | | tcp, sctp and dccp trackers re-use the userspace ctnetlink states to index their timeout arrays, which means timeout[0] is never used. Copy the 'new' state (syn-sent, dccp-request, ..) to 0 as well so external users can simply read it off timeouts[0] without need to differentiate dccp/sctp/tcp and udp/icmp/gre/generic. The alternative is to map all array accesses to 'i - 1', but that is a much more intrusive change. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* netfilter: conntrack: remove get_timeout() indirectionFlorian Westphal2018-07-161-12/+11
| | | | | | | Not needed, we can have the l4trackers fetch it themselvs. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* netfilter: conntrack: avoid l4proto pkt_to_tuple callsFlorian Westphal2018-07-161-19/+0
| | | | | | | | Handle common protocols (udp, tcp, ..), in the core and only do the call if needed by the l4proto tracker. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* netfilter: conntrack: avoid calls to l4proto invert_tupleFlorian Westphal2018-07-161-10/+0
| | | | | | | | Handle the common cases (tcp, udp, etc). in the core and only do the indirect call for the protocols that need it (GRE for instance). Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* netfilter: Fix handling simultaneous open in TCP conntrackJozsef Kadlecsik2018-04-271-0/+11
| | | | | | | | | | | | | Dominique Martinet reported a TCP hang problem when simultaneous open was used. The problem is that the tcp_conntracks state table is not smart enough to handle the case. The state table could be fixed by introducing a new state, but that would require more lines of code compared to this patch, due to the required backward compatibility with ctnetlink. Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu> Reported-by: Dominique Martinet <asmadeus@codewreck.org> Tested-by: Dominique Martinet <asmadeus@codewreck.org> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* netfilter: nf_conntrack: add IPS_OFFLOAD status bitPablo Neira Ayuso2018-01-081-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | This new bit tells us that the conntrack entry is owned by the flow table offload infrastructure. # cat /proc/net/nf_conntrack ipv4 2 tcp 6 src=10.141.10.2 dst=147.75.205.195 sport=36392 dport=443 src=147.75.205.195 dst=192.168.2.195 sport=443 dport=36392 [OFFLOAD] mark=0 zone=0 use=2 Note the [OFFLOAD] tag in the listing. The timer of such conntrack entries look like stopped from userspace. In practise, to make sure the conntrack entry does not go away, the conntrack timer is periodically set to an arbitrary large value that gets refreshed on every iteration from the garbage collector, so it never expires- and they display no internal state in the case of TCP flows. This allows us to save a bitcheck from the packet path via nf_ct_is_expired(). Conntrack entries that have been offloaded to the flow table infrastructure cannot be deleted/flushed via ctnetlink. The flow table infrastructure is also responsible for releasing this conntrack entry. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* netfilter: conntrack: timeouts can be constFlorian Westphal2018-01-081-1/+1
| | | | | | | | Nowadays this is just the default template that is used when setting up the net namespace, so nothing writes to these locations. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* netfilter: conntrack: l4 protocol trackers can be constFlorian Westphal2018-01-081-2/+2
| | | | | | | | previous patches removed all writes to these structs so we can now mark them as const. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* netfilter: conntrack: remove nlattr_size pointer from l4proto trackersFlorian Westphal2018-01-081-8/+8
| | | | | | | | similar to previous commit, but instead compute this at compile time and turn nlattr_size into an u16. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* netfilter: conntrack: lower timeout to RETRANS seconds if window is 0Florian Westphal2017-11-201-0/+3
| | | | | | | | | | | | | | | | | | | | | | When zero window is announced we can get into a situation where connection stays around forever: 1. One side announces zero window. 2. Other side closes. In this case, no FIN is sent (stuck in send queue). Unless other side opens the window up again conntrack stays in ESTABLISHED state for a very long time. Lets alleviate this by lowering the timeout to RETRANS (5 minutes), the other end should be sending zero window probes to keep the connection established as long as a socket still exists. Cc: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu> Signed-off-by: Florian Westphal <fw@strlen.de> Acked-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
generated by cgit v1.2.3 (git 2.25.1) at 2024-08-30 00:04:32 +0000