bugzilla-daemon at netfilter.org
2024-Apr-03 22:14 UTC
[Bug 1742] New: using nfqueue breaks SCTP connection (tracking)
https://bugzilla.netfilter.org/show_bug.cgi?id=1742 Bug ID: 1742 Summary: using nfqueue breaks SCTP connection (tracking) Product: libnetfilter_queue Version: unspecified Hardware: All OS: All Status: NEW Severity: normal Priority: P5 Component: libnetfilter_queue Assignee: netfilter-buglog at lists.netfilter.org Reporter: antonio.ojea.garcia at gmail.com I'm using a golang library for interacting with nfqueue, it is a very simple logic, I add the following rule table inet kube-netpol { comment "rules for kubernetes NetworkPolicy" chain forward { type filter hook forward priority filter - 5; policy accept; ct state new queue to 100 } } and in userspace I process the packet to emit a verdict. Everything works fine with TCP and UDP, but when using SCTP I can see the packet its modified and breaks the establishment of the connection, more details in https://github.com/aojea/kube-netpol/issues/8 Once I remove the `nfqueue` rule the SCTP connection is established correctly. I triple checked the userspace program accepts the packet and removing the nfqueue rules makes the connection work. I've added a trace (by the way kudos for the tracing functionality is really a great improvement) and I can see how the packet is dropped in a rule that drops connections with invalid state trace id 0329b184 ip filter trace_chain packet: iif "eth0" ether saddr 02:42:c0:a8:08:02 ether daddr 02:42:c0:a8:08:03 ip saddr 10.244.1.47 ip daddr 10.244.2.47 ip dscp cs0 ip ecn ect0 ip ttl 63 ip id 0 ip length 68 sctp sport 47261 sctp dport 8080 sctp vtag 0 @th,96,64 0x10000240486b6e3 trace id 0329b184 ip filter trace_chain rule ip protocol sctp meta nftrace set 1 (verdict continue) trace id 0329b184 ip filter trace_chain verdict continue trace id 0329b184 ip filter trace_chain policy accept trace id 0329b184 inet kube-netpol forward packet: iif "eth0" oif "vetha2b65671" ether saddr 02:42:c0:a8:08:02 ether daddr 02:42:c0:a8:08:03 ip saddr 10.244.1.47 ip daddr 10.244.2.47 ip dscp cs0 ip ecn ect0 ip ttl 62 ip id 0 ip protocol sctp ip length 68 sctp sport 47261 sctp dport 8080 sctp vtag 0 @th,96,64 0x10000240486b6e3 trace id 0329b184 inet kube-netpol forward verdict continue trace id 0329b184 inet kube-netpol forward policy accept trace id 0329b184 ip filter FORWARD packet: iif "eth0" oif "vetha2b65671" ether saddr 02:42:c0:a8:08:02 ether daddr 02:42:c0:a8:08:03 ip saddr 10.244.1.47 ip daddr 10.244.2.47 ip dscp cs0 ip ecn ect0 ip ttl 62 ip id 0 ip length 68 sctp sport 47261 sctp dport 8080 sctp vtag 0 @th,96,64 0x10000240486b6e3 trace id 0329b184 ip filter FORWARD rule counter packets 5735 bytes 2667239 jump KUBE-FORWARD (verdict jump KUBE-FORWARD) trace id 0329b184 ip filter KUBE-FORWARD rule ct state invalid counter packets 8 bytes 544 drop (verdict drop) if I remove the nfqueue rule the packet goes through trace id 058bdf29 ip filter trace_chain packet: iif "eth0" ether saddr 02:42:c0:a8:08:02 ether daddr 02:42:c0:a8:08:03 ip saddr 10.244.1.47 ip daddr 10.244.2.47 ip dscp cs0 ip ecn ect0 ip ttl 63 ip id 0 ip length 68 sctp sport 33348 sctp dport 8080 sctp vtag 0 @th,96,64 0x10000244fde5e72 trace id 058bdf29 ip filter trace_chain rule ip protocol sctp meta nftrace set 1 (verdict continue) trace id 058bdf29 ip filter trace_chain verdict continue trace id 058bdf29 ip filter trace_chain policy accept trace id 058bdf29 ip nat PREROUTING packet: iif "eth0" ether saddr 02:42:c0:a8:08:02 ether daddr 02:42:c0:a8:08:03 ip saddr 10.244.1.47 ip daddr 10.244.2.47 ip dscp cs0 ip ecn ect0 ip ttl 63 ip id 0 ip length 68 sctp sport 33348 sctp dport 8080 sctp vtag 0 @th,96,64 0x10000244fde5e72 trace id 058bdf29 ip nat PREROUTING rule counter packets 17924 bytes 1098260 jump KUBE-SERVICES (verdict jump KUBE-SERVICES) trace id 058bdf29 ip nat KUBE-SERVICES verdict continue trace id 058bdf29 ip nat PREROUTING verdict continue trace id 058bdf29 ip nat PREROUTING policy accept trace id 058bdf29 ip filter FORWARD packet: iif "eth0" oif "vetha2b65671" ether saddr 02:42:c0:a8:08:02 ether daddr 02:42:c0:a8:08:03 ip saddr 10.244.1.47 ip daddr 10.244.2.47 ip dscp cs0 ip ecn ect0 ip ttl 62 ip id 0 ip length 68 sctp sport 33348 sctp dport 8080 sctp vtag 0 @th,96,64 0x10000244fde5e72 trace id 058bdf29 ip filter FORWARD rule ct state new counter packets 2894 bytes 195836 jump KUBE-PROXY-FIREWALL (verdict jump KUBE-PROXY-FIREWALL) trace id 058bdf29 ip filter KUBE-PROXY-FIREWALL verdict continue trace id 058bdf29 ip filter FORWARD rule counter packets 5800 bytes 2671691 jump KUBE-FORWARD (verdict jump KUBE-FORWARD) trace id 058bdf29 ip filter KUBE-FORWARD verdict continue trace id 058bdf29 ip filter FORWARD rule ct state new counter packets 2832 bytes 191716 jump KUBE-SERVICES (verdict jump KUBE-SERVICES) trace id 058bdf29 ip filter KUBE-SERVICES verdict continue trace id 058bdf29 ip filter FORWARD rule ct state new counter packets 2826 bytes 191324 jump KUBE-EXTERNAL-SERVICES (verdict jump KUBE-EXTERNAL-SERVICES) trace id 058bdf29 ip filter KUBE-EXTERNAL-SERVICES verdict continue trace id 058bdf29 ip filter FORWARD verdict continue trace id 058bdf29 ip filter FORWARD policy accept trace id 058bdf29 ip nat POSTROUTING packet: iif "eth0" oif "vetha2b65671" ether saddr 02:42:c0:a8:08:02 ether daddr 02:42:c0:a8:08:03 ip saddr 10.244.1.47 ip daddr 10.244.2.47 ip dscp cs0 ip ecn ect0 ip ttl 62 ip id 0 ip length 68 sctp sport 33348 sctp dport 8080 sctp vtag 0 @th,96,64 0x10000244fde5e72 trace id 058bdf29 ip nat POSTROUTING rule counter packets 5868 bytes 374884 jump KUBE-POSTROUTING (verdict jump KUBE-POSTROUTING) trace id 058bdf29 ip nat KUBE-POSTROUTING verdict return trace id 058bdf29 ip nat POSTROUTING rule fib daddr type != local counter packets 2834 bytes 191394 jump KIND-MASQ-AGENT (verdict jump KIND-MASQ-AGENT) trace id 058bdf29 ip nat KIND-MASQ-AGENT verdict return trace id 058bdf29 ip nat POSTROUTING verdict continue trace id 058bdf29 ip nat POSTROUTING policy accept -- You are receiving this mail because: You are watching all bug changes. -------------- next part -------------- An HTML attachment was scrubbed... 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bugzilla-daemon at netfilter.org
2024-Apr-04 08:42 UTC
[Bug 1742] using nfqueue breaks SCTP connection (tracking)
https://bugzilla.netfilter.org/show_bug.cgi?id=1742 Antonio Ojea <antonio.ojea.garcia at gmail.com> changed: What |Removed |Added ---------------------------------------------------------------------------- Priority|P5 |P2 Component|libnetfilter_queue |netfilter hooks Product|libnetfilter_queue |netfilter/iptables -- You are receiving this mail because: You are watching all bug changes. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.netfilter.org/pipermail/netfilter-buglog/attachments/20240404/369b6da4/attachment.html>
bugzilla-daemon at netfilter.org
2024-Apr-07 20:27 UTC
[Bug 1742] using nfqueue breaks SCTP connection (tracking)
https://bugzilla.netfilter.org/show_bug.cgi?id=1742 --- Comment #1 from Antonio Ojea <antonio.ojea.garcia at gmail.com> --- I?ve used this great tool from the cilium project (pwru) to trace the packet and I can observe that if I don?t use nfqueue I got this trace 0xffff88810983aa00 0 [<empty>(280243)] ip_forward netns=4026533169 mark=0x0 iface=168(eth0) proto=0x0800 mtu=1500 len=84 192.168.8.2:0->10.244.2.47:0() 0xffff88810983aa00 0 [<empty>(280243)] nf_hook_slow netns=4026533169 mark=0x0 iface=168(eth0) proto=0x0800 mtu=1500 len=84 192.168.8.2:0->10.244.2.47:0() 0xffff88810983aa00 0 [<empty>(280243)] ip_forward_finish netns=4026533169 mark=0x0 iface=168(eth0) proto=0x0800 mtu=1500 len=84 192.168.8.2:0->10.244.2.47:0() and when using it there are some functions that operate on the sctp checksum 0xffff88810749bf00 29 [<empty>(274286)] ip_forward netns=4026532933 mark=0x0 iface=47 proto=0x0800 mtu=1500 len=68 10.244.1.47:0->10.244.2.47:0() 0xffff88810749bf00 29 [<empty>(274286)] nf_hook_slow netns=4026532933 mark=0x0 iface=47 proto=0x0800 mtu=1500 len=68 10.244.1.47:0->10.244.2.47:0() 0xffff88810749bf00 29 [<empty>(274286)] nf_queue netns=4026532933 mark=0x0 iface=47 proto=0x0800 mtu=1500 len=68 10.244.1.47:0->10.244.2.47:0() 0xffff88810749bf00 29 [<empty>(274286)] __nf_queue netns=4026532933 mark=0x0 iface=47 proto=0x0800 mtu=1500 len=68 10.244.1.47:0->10.244.2.47:0() 0xffff88810749bf00 29 [<empty>(274286)] skb_checksum_help netns=4026532933 mark=0x0 iface=47 proto=0x0800 mtu=1500 len=68 10.244.1.47:0->10.244.2.47:0() 0xffff88810749bf00 29 [<empty>(274286)] skb_ensure_writable netns=4026532933 mark=0x0 iface=47 proto=0x0800 mtu=1500 len=68 10.244.1.47:0->10.244.2.47:0() 0xffff88810749bf00 26 [<empty>(3319058)] nf_reroute netns=4026532933 mark=0x0 iface=47 proto=0x0800 mtu=1500 len=68 10.244.1.47:0->10.244.2.47:0() 0xffff88810749bf00 26 [<empty>(3319058)] ip_forward_finish netns=4026532933 mark=0x0 iface=47 proto=0x0800 mtu=1500 len=68 10.244.1.47:0->10.244.2.47:0() The packet captures confirms that when using nfqueue some packet modification happens https://github.com/aojea/kube-netpol/issues/8#issuecomment-2039184720 As a workaround, if I set the flag NFQA_CFG_F_GSO then the packet is not modified and connection works perfectly (I?m only using nfqueue for dropping) -- You are receiving this mail because: You are watching all bug changes. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.netfilter.org/pipermail/netfilter-buglog/attachments/20240407/08ac02d7/attachment.html>
bugzilla-daemon at netfilter.org
2024-Apr-07 20:34 UTC
[Bug 1742] using nfqueue breaks SCTP connection (tracking)
https://bugzilla.netfilter.org/show_bug.cgi?id=1742 Pablo Neira Ayuso <pablo at netfilter.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |pablo at netfilter.org --- Comment #2 from Pablo Neira Ayuso <pablo at netfilter.org> --- (In reply to Antonio Ojea from comment #1)> > I?ve used this great tool from the cilium project (pwru) to trace the packet > and I can observe that if I don?t use nfqueue I got this trace > > 0xffff88810983aa00 0 [<empty>(280243)] ip_forward > netns=4026533169 mark=0x0 iface=168(eth0) proto=0x0800 mtu=1500 len=84 > 192.168.8.2:0->10.244.2.47:0() > 0xffff88810983aa00 0 [<empty>(280243)] nf_hook_slow > netns=4026533169 mark=0x0 iface=168(eth0) proto=0x0800 mtu=1500 len=84 > 192.168.8.2:0->10.244.2.47:0() > 0xffff88810983aa00 0 [<empty>(280243)] ip_forward_finish > netns=4026533169 mark=0x0 iface=168(eth0) proto=0x0800 mtu=1500 len=84 > 192.168.8.2:0->10.244.2.47:0() > > and when using it there are some functions that operate on the sctp checksum > > 0xffff88810749bf00 29 [<empty>(274286)] ip_forward > netns=4026532933 mark=0x0 iface=47 proto=0x0800 mtu=1500 len=68 > 10.244.1.47:0->10.244.2.47:0() > 0xffff88810749bf00 29 [<empty>(274286)] nf_hook_slow > netns=4026532933 mark=0x0 iface=47 proto=0x0800 mtu=1500 len=68 > 10.244.1.47:0->10.244.2.47:0() > 0xffff88810749bf00 29 [<empty>(274286)] nf_queue > netns=4026532933 mark=0x0 iface=47 proto=0x0800 mtu=1500 len=68 > 10.244.1.47:0->10.244.2.47:0() > 0xffff88810749bf00 29 [<empty>(274286)] __nf_queue > netns=4026532933 mark=0x0 iface=47 proto=0x0800 mtu=1500 len=68 > 10.244.1.47:0->10.244.2.47:0() > 0xffff88810749bf00 29 [<empty>(274286)] skb_checksum_help > netns=4026532933 mark=0x0 iface=47 proto=0x0800 mtu=1500 len=68 > 10.244.1.47:0->10.244.2.47:0() > 0xffff88810749bf00 29 [<empty>(274286)] skb_ensure_writable > netns=4026532933 mark=0x0 iface=47 proto=0x0800 mtu=1500 len=68 > 10.244.1.47:0->10.244.2.47:0() > 0xffff88810749bf00 26 [<empty>(3319058)] nf_reroute > netns=4026532933 mark=0x0 iface=47 proto=0x0800 mtu=1500 len=68 > 10.244.1.47:0->10.244.2.47:0() > 0xffff88810749bf00 26 [<empty>(3319058)] ip_forward_finish > netns=4026532933 mark=0x0 iface=47 proto=0x0800 mtu=1500 len=68 > 10.244.1.47:0->10.244.2.47:0() > > > The packet captures confirms that when using nfqueue some packet > modification happens > https://github.com/aojea/kube-netpol/issues/8#issuecomment-2039184720 > > > As a workaround, if I set the flag NFQA_CFG_F_GSO then the packet is not > modified and connection works perfectly (I?m only using nfqueue for dropping)SCTP checksum is lacking in nfnetlink_queue. There is a patch for nftables that could be used for reference: commit 346e320cb2103edef709c4466a29140c4a8e527a Author: Davide Caratti <dcaratti at redhat.com> Date: Thu Oct 15 18:39:27 2020 +0200 netfilter: nftables: allow re-computing sctp CRC-32C in 'payload' statements There is a skb_checksum_help() call in nfnetlink_queue that needs to be replaced by a helper function that run the specific SCTP checksum function. -- You are receiving this mail because: You are watching all bug changes. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.netfilter.org/pipermail/netfilter-buglog/attachments/20240407/2b16a70e/attachment-0001.html>
bugzilla-daemon at netfilter.org
2024-Apr-07 20:38 UTC
[Bug 1742] using nfqueue breaks SCTP connection (tracking)
https://bugzilla.netfilter.org/show_bug.cgi?id=1742 --- Comment #3 from Pablo Neira Ayuso <pablo at netfilter.org> --- (In reply to Pablo Neira Ayuso from comment #2)> (In reply to Antonio Ojea from comment #1) > > As a workaround, if I set the flag NFQA_CFG_F_GSO then the packet is not > > modified and connection works perfectly (I?m only using nfqueue for dropping)Workaround makes sense, because branch depends on NFQA_CFG_F_GSO flag: case NFQNL_COPY_PACKET: if (!(queue->flags & NFQA_CFG_F_GSO) && entskb->ip_summed == CHECKSUM_PARTIAL && skb_checksum_help(entskb)) return NULL; if set on, the checksum calculation is skipped. For filtering (only dropping), enabling NFQA_CFG_F_GSO makes perfect sense (unless your heuristic is based on the real packet as seen in the wire, that is, GRO does not interference with the filtering criteria) -- You are receiving this mail because: You are watching all bug changes. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.netfilter.org/pipermail/netfilter-buglog/attachments/20240407/2005a6a7/attachment.html>
bugzilla-daemon at netfilter.org
2024-Apr-07 20:51 UTC
[Bug 1742] using nfqueue breaks SCTP connection (tracking)
https://bugzilla.netfilter.org/show_bug.cgi?id=1742 Antonio Ojea <antonio.ojea.garcia at gmail.com> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |ASSIGNED --- Comment #4 from Antonio Ojea <antonio.ojea.garcia at gmail.com> ---> There is a skb_checksum_help() call in nfnetlink_queue that needs to be replaced by a helper function that run the specific SCTP checksum function.great, this seems a good opportunity to contribute, let me try to see if I'm able to submit a patch -- You are receiving this mail because: You are watching all bug changes. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.netfilter.org/pipermail/netfilter-buglog/attachments/20240407/ec79ff63/attachment.html>
bugzilla-daemon at netfilter.org
2024-May-02 21:54 UTC
[Bug 1742] using nfqueue breaks SCTP connection (tracking)
https://bugzilla.netfilter.org/show_bug.cgi?id=1742 --- Comment #5 from Antonio Ojea <antonio.ojea.garcia at gmail.com> --- Pablo I need some guidance, I want to add a test and I think the right place is in tools/testing/selftests/netfilter/nft_queue.sh , however, I need some sctp client/server to generate the traffic. The only client/server I could find is in another folder tools/testing/selftests/net/sctp_hello.c Should I duplicate the sctp_hello.c file under tools/testing/selftests/netfilter? -- You are receiving this mail because: You are watching all bug changes. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.netfilter.org/pipermail/netfilter-buglog/attachments/20240502/437f8e77/attachment.html>
bugzilla-daemon at netfilter.org
2024-May-02 22:09 UTC
[Bug 1742] using nfqueue breaks SCTP connection (tracking)
https://bugzilla.netfilter.org/show_bug.cgi?id=1742 --- Comment #6 from Pablo Neira Ayuso <pablo at netfilter.org> --- (In reply to Antonio Ojea from comment #5)> Pablo I need some guidance, I want to add a test and I think the right place > is in tools/testing/selftests/netfilter/nft_queue.sh , however, I need some > sctp client/server to generate the traffic. > > The only client/server I could find is in another folder > tools/testing/selftests/net/sctp_hello.c > > Should I duplicate the sctp_hello.c file under > tools/testing/selftests/netfilter?Are you using the net-next.git tree? Florian has recently moved all netfilter tests to tools/testing/selftests/net/ , that would allow you to reuse the existing file. I can help with rebasing if you have done it already. Thanks a lot for working on a patch for this. -- You are receiving this mail because: You are watching all bug changes. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.netfilter.org/pipermail/netfilter-buglog/attachments/20240502/4498f996/attachment.html>
bugzilla-daemon at netfilter.org
2024-May-02 22:09 UTC
[Bug 1742] using nfqueue breaks SCTP connection (tracking)
https://bugzilla.netfilter.org/show_bug.cgi?id=1742 --- Comment #7 from Pablo Neira Ayuso <pablo at netfilter.org> --- (In reply to Pablo Neira Ayuso from comment #6)> (In reply to Antonio Ojea from comment #5) > > Pablo I need some guidance, I want to add a test and I think the right place > > is in tools/testing/selftests/netfilter/nft_queue.sh , however, I need some > > sctp client/server to generate the traffic. > > > > The only client/server I could find is in another folder > > tools/testing/selftests/net/sctp_hello.c > > > > Should I duplicate the sctp_hello.c file under > > tools/testing/selftests/netfilter? > > Are you using the net-next.git tree?I am referring to this tree: https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git/ -- You are receiving this mail because: You are watching all bug changes. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.netfilter.org/pipermail/netfilter-buglog/attachments/20240502/f59c77d0/attachment.html>
bugzilla-daemon at netfilter.org
2024-May-03 13:04 UTC
[Bug 1742] using nfqueue breaks SCTP connection (tracking)
https://bugzilla.netfilter.org/show_bug.cgi?id=1742 --- Comment #8 from Antonio Ojea <antonio.ojea.garcia at gmail.com> --- It is the first time that I send a patch to the kernel so sorry in advance for all the noise :) Let me describe the situation, I think I didn't get right the problem, these are the patches I sent https://patchwork.ozlabs.org/project/netfilter-devel/list/?series=405380 I have a test in patch 2 that reproduces the problem, that I think is good If I apply patch 1 IIUIC it skips skb_checksum_help() , this patch solves the problem but does not seem right, does it? diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c index 00f4bd21c59b..428014aea396 100644 --- a/net/netfilter/nfnetlink_queue.c +++ b/net/netfilter/nfnetlink_queue.c @@ -600,6 +600,7 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue, case NFQNL_COPY_PACKET: if (!(queue->flags & NFQA_CFG_F_GSO) && entskb->ip_summed == CHECKSUM_PARTIAL && + (skb_csum_is_sctp(entskb) && skb_crc32c_csum_help(entskb)) && skb_checksum_help(entskb)) return NULL; If instead of an AND I use an OR - skb_checksum_help(entskb)) + ((skb_csum_is_sctp(entskb) && skb_crc32c_csum_help(entskb)) || + skb_checksum_help(entskb))) now the test fails ... so it seems the problem is skb_checksum_help() ?? -- You are receiving this mail because: You are watching all bug changes. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.netfilter.org/pipermail/netfilter-buglog/attachments/20240503/40c64460/attachment.html>
bugzilla-daemon at netfilter.org
2024-Oct-03 10:42 UTC
[Bug 1742] using nfqueue breaks SCTP connection (tracking)
https://bugzilla.netfilter.org/show_bug.cgi?id=1742 Antonio Ojea <antonio.ojea.garcia at gmail.com> changed: What |Removed |Added ---------------------------------------------------------------------------- Resolution|--- |FIXED Status|ASSIGNED |RESOLVED --- Comment #9 from Antonio Ojea <antonio.ojea.garcia at gmail.com> --- Fixed by https://github.com/torvalds/linux/commit/26a77d02891ab62172085a4f94af9b3c90aed387 -- You are receiving this mail because: You are watching all bug changes. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.netfilter.org/pipermail/netfilter-buglog/attachments/20241003/527b2905/attachment.html>
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