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2020-08-28netfilter: ip6t_NPT: rewrite addresses in ICMPv6 original packetMichael Zhou1-0/+39
Detect and rewrite a prefix embedded in an ICMPv6 original packet that was rewritten by a corresponding DNPT/SNPT rule so it will be recognised by the host that sent the original packet. Example Rules in effect on the 1:2:3:4::/64 + 5:6:7:8::/64 side router: * SNPT src-pfx 1:2:3:4::/64 dst-pfx 5:6:7:8::/64 * DNPT src-pfx 5:6:7:8::/64 dst-pfx 1:2:3:4::/64 No rules on the 9:a:b:c::/64 side. 1. 1:2:3:4::1 sends UDP packet to 9:a:b:c::1 2. Router applies SNPT changing src to 5:6:7:8::ffef::1 3. 9:a:b:c::1 receives packet with (src 5:6:7:8::ffef::1 dst 9:a:b:c::1) and replies with ICMPv6 port unreachable to 5:6:7:8::ffef::1, including original packet (src 5:6:7:8::ffef::1 dst 9:a:b:c::1) 4. Router forwards ICMPv6 packet with (src 9:a:b:c::1 dst 5:6:7:8::ffef::1) including original packet (src 5:6:7:8::ffef::1 dst 9:a:b:c::1) and applies DNPT changing dst to 1:2:3:4::1 5. 1:2:3:4::1 receives ICMPv6 packet with (src 9:a:b:c::1 dst 1:2:3:4::1) including original packet (src 5:6:7:8::ffef::1 dst 9:a:b:c::1). It doesn't recognise the original packet as the src doesn't match anything it originally sent With this change, at step 4, DNPT will also rewrite the original packet src to 1:2:3:4::1, so at step 5, 1:2:3:4::1 will recognise the ICMPv6 error and provide feedback to the application properly. Conversely, SNPT will help when ICMPv6 errors are sent from the translated network. 1. 9:a:b:c::1 sends UDP packet to 5:6:7:8::ffef::1 2. Router applies DNPT changing dst to 1:2:3:4::1 3. 1:2:3:4::1 receives packet with (src 9:a:b:c::1 dst 1:2:3:4::1) and replies with ICMPv6 port unreachable to 9:a:b:c::1 including original packet (src 9:a:b:c::1 dst 1:2:3:4::1) 4. Router forwards ICMPv6 packet with (src 1:2:3:4::1 dst 9:a:b:c::1) including original packet (src 9:a:b:c::1 dst 1:2:3:4::1) and applies SNPT changing src to 5:6:7:8::ffef::1 5. 9:a:b:c::1 receives ICMPv6 packet with (src 5:6:7:8::ffef::1 dst 9:a:b:c::1) including original packet (src 9:a:b:c::1 dst 1:2:3:4::1). It doesn't recognise the original packet as the dst doesn't match anything it already sent The change to SNPT means the ICMPv6 original packet dst will be rewritten to 5:6:7:8::ffef::1 in step 4, allowing the error to be properly recognised in step 5. Signed-off-by: Michael Zhou <mzhou@cse.unsw.edu.au> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-06-19treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500Thomas Gleixner1-4/+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>
2017-01-09xtables: extend matches and targets with .usersizeWillem de Bruijn1-0/+2
In matches and targets that define a kernel-only tail to their xt_match and xt_target data structs, add a field .usersize that specifies up to where data is to be shared with userspace. Performed a search for comment "Used internally by the kernel" to find relevant matches and targets. Manually inspected the structs to derive a valid offsetof. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-04-07Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-1/+1
Conflicts: drivers/nfc/microread/mei.c net/netfilter/nfnetlink_queue_core.c Pull in 'net' to get Eric Biederman's AF_UNIX fix, upon which some cleanups are going to go on-top. Signed-off-by: David S. Miller <davem@davemloft.net>
2013-04-03netfilter: ip6t_NPT: Fix translation for non-multiple of 32 prefix lengthsMatthias Schiffer1-1/+1
The bitmask used for the prefix mangling was being calculated incorrectly, leading to the wrong part of the address being replaced when the prefix length wasn't a multiple of 32. Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-03-25Merge branch 'master' of git://1984.lsi.us.es/nf-nextDavid S. Miller1-8/+3
Pablo Neira Ayuso says: ==================== The following patchset contains Netfilter/IPVS updates for your net-next tree, they are: * Better performance in nfnetlink_queue by avoiding copy from the packet to netlink message, from Eric Dumazet. * Remove unnecessary locking in the exit path of ebt_ulog, from Gao Feng. * Use new function ipv6_iface_scope_id in nf_ct_ipv6, from Hannes Frederic Sowa. * A couple of sparse fixes for IPVS, from Julian Anastasov. * Use xor hashing in nfnetlink_queue, as suggested by Eric Dumazet, from myself. * Allow to dump expectations per master conntrack via ctnetlink, from myself. * A couple of cleanups to use PTR_RET in module init path, from Silviu-Mihai Popescu. * Remove nf_conntrack module a bit faster if netns are in use, from Vladimir Davydov. * Use checksum_partial in ip6t_NPT, from YOSHIFUJI Hideaki. * Sparse fix for nf_conntrack, from Stephen Hemminger. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2013-03-15netfilter: ip6t_NPT: restrict to mangle tableFlorian Westphal1-0/+2
As the translation is stateless, using it in nat table doesn't work (only initial packet is translated). filter table OUTPUT works but won't re-route the packet after translation. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-03-15netfilter: ip6t_NPT: Use csum_partial()YOSHIFUJI Hideaki1-8/+3
[ Some fixes went into mainstream before this patch, so I needed to rebase it upon the current tree, that's why it's different from the original one posted on the list --pablo ] Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-02-07netfilter: ip6t_NPT: Ensure to check lower part of prefixes are zeroYOSHIFUJI Hideaki / 吉藤英明1-0/+10
RFC 6296 points that address bits that are not part of the prefix has to be zeroed. Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-02-07netfilter: ip6t_NPT: Fix prefix manglingYOSHIFUJI Hideaki / 吉藤英明1-1/+1
Make sure only the bits that are part of the prefix are mangled. Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-02-07netfilter: ip6t_NPT: Fix adjustment calculationYOSHIFUJI Hideaki / 吉藤英明1-3/+3
Cast __wsum from/to __sum16 is wrong. Instead, apply appropriate conversion function: csum_unfold() or csum_fold(). [ The original patch has been modified to undo the final ~ that csum_fold returns. We only need to fold the 32-bit word that results from the checksum calculation into a 16-bit to ensure that the original subnet is restored appropriately. Spotted by Ulrich Weber. ] Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-01-04netfilter: ip6t_NPT: fix IPv6 NTP checksum calculationUlrich Weber1-26/+7
csum16_add() has a broken carry detection, should be: sum += sum < (__force u16)b; Instead of fixing csum16_add, remove the custom checksum functions and use the generic csum_add/csum_sub ones. Signed-off-by: Ulrich Weber <ulrich.weber@sophos.com> Acked-by: Patrick McHardy <kaber@trash.net> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2012-08-30netfilter: ip6tables: add stateless IPv6-to-IPv6 Network Prefix Translation ↵Patrick McHardy1-0/+165
target Signed-off-by: Patrick McHardy <kaber@trash.net>