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commit ea64d8d6c675c0bb712689b13810301de9d8f77a upstream.
If the UDP header of a local VXLAN endpoint is NAT-ed, and the VXLAN
device has disabled UDP checksums and enabled Tx checksum offloading,
then the skb passed to udp_manip_pkt() has hdr->check == 0 (outer
checksum disabled) and skb->ip_summed == CHECKSUM_PARTIAL (inner packet
checksum offloaded).
Because of the ->ip_summed value, udp_manip_pkt() tries to update the
outer checksum with the new address and port, leading to an invalid
checksum sent on the wire, as the original null checksum obviously
didn't take the old address and port into account.
So, we can't take ->ip_summed into account in udp_manip_pkt(), as it
might not refer to the checksum we're acting on. Instead, we can base
the decision to update the UDP checksum entirely on the value of
hdr->check, because it's null if and only if checksum is disabled:
* A fully computed checksum can't be 0, since a 0 checksum is
represented by the CSUM_MANGLED_0 value instead.
* A partial checksum can't be 0, since the pseudo-header always adds
at least one non-zero value (the UDP protocol type 0x11) and adding
more values to the sum can't make it wrap to 0 as the carry is then
added to the wrapped number.
* A disabled checksum uses the special value 0.
The problem seems to be there from day one, although it was probably
not visible before UDP tunnels were implemented.
Fixes: 5b1158e909ec ("[NETFILTER]: Add NAT support for nf_conntrack")
Signed-off-by: Guillaume Nault <gnault@redhat.com>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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This is a patch proposal to support shifted ranges in portmaps. (i.e. tcp/udp
incoming port 5000-5100 on WAN redirected to LAN 192.168.1.5:2000-2100)
Currently DNAT only works for single port or identical port ranges. (i.e.
ports 5000-5100 on WAN interface redirected to a LAN host while original
destination port is not altered) When different port ranges are configured,
either 'random' mode should be used, or else all incoming connections are
mapped onto the first port in the redirect range. (in described example
WAN:5000-5100 will all be mapped to 192.168.1.5:2000)
This patch introduces a new mode indicated by flag NF_NAT_RANGE_PROTO_OFFSET
which uses a base port value to calculate an offset with the destination port
present in the incoming stream. That offset is then applied as index within the
redirect port range (index modulo rangewidth to handle range overflow).
In described example the base port would be 5000. An incoming stream with
destination port 5004 would result in an offset value 4 which means that the
NAT'ed stream will be using destination port 2004.
Other possibilities include deterministic mapping of larger or multiple ranges
to a smaller range : WAN:5000-5999 -> LAN:5000-5099 (maps WAN port 5*xx to port
51xx)
This patch does not change any current behavior. It just adds new NAT proto
range functionality which must be selected via the specific flag when intended
to use.
A patch for iptables (libipt_DNAT.c + libip6t_DNAT.c) will also be proposed
which makes this functionality immediately available.
Signed-off-by: Thierry Du Tre <thierry@dtsystems.be>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
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udplite nat was copied from udp nat, they are virtually 100% identical.
Not really surprising given udplite is just udp with partial csum coverage.
old:
text data bss dec hex filename
11606 1457 210 13273 33d9 nf_nat.ko
330 0 2 332 14c nf_nat_proto_udp.o
276 0 2 278 116 nf_nat_proto_udplite.o
new:
text data bss dec hex filename
11598 1457 210 13265 33d1 nf_nat.ko
640 0 4 644 284 nf_nat_proto_udp.o
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
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inet_proto_csum_replace4,2,16 take a pseudohdr argument which indicates
the checksum field carries a pseudo header. This argument should be a
boolean instead of an int.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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replace:
#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
with
#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
replace:
#if !defined(CONFIG_NF_NAT) && !defined(CONFIG_NF_NAT_MODULE)
with
#if !IS_ENABLED(CONFIG_NF_NAT)
replace:
#if !defined(CONFIG_NF_CONNTRACK) && !defined(CONFIG_NF_CONNTRACK_MODULE)
with
#if !IS_ENABLED(CONFIG_NF_CONNTRACK)
And add missing:
IS_ENABLED(CONFIG_NF_CT_NETLINK)
in net/ipv{4,6}/netfilter/nf_nat_l3proto_ipv{4,6}.c
Signed-off-by: Duan Jiong <duanj.fnst@cn.fujitsu.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
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Convert the IPv4 NAT implementation to a protocol independent core and
address family specific modules.
Signed-off-by: Patrick McHardy <kaber@trash.net>
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