Kyle SwensonandPablo Neira Ayuso 0f1ae2821f netfilter: nat: restore default DNAT behavior
When a DNAT rule is configured via iptables with different port ranges,

iptables -t nat -A PREROUTING -p tcp -d 10.0.0.2 -m tcp --dport 32000:32010
-j DNAT --to-destination 192.168.0.10:21000-21010

we seem to be DNATing to some random port on the LAN side. While this is
expected if --random is passed to the iptables command, it is not
expected without passing --random.  The expected behavior (and the
observed behavior prior to the commit in the "Fixes" tag) is the traffic
will be DNAT'd to 192.168.0.10:21000 unless there is a tuple collision
with that destination.  In that case, we expect the traffic to be
instead DNAT'd to 192.168.0.10:21001, so on so forth until the end of
the range.

This patch intends to restore the behavior observed prior to the "Fixes"
tag.

Fixes: 6ed5943f87 ("netfilter: nat: remove l4 protocol port rovers")
Signed-off-by: Kyle Swenson <kyle.swenson@est.tech>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2024-02-15 00:20:00 +01:00
2023-12-20 19:26:31 -05:00
2024-02-13 10:19:05 -08:00
2024-02-04 12:20:36 +00:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
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In order to build the documentation, use ``make htmldocs`` or
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    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
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