IPtables will seek to preserve the source port unchanged when
doing masquerading, if possible. NFS has a pseudo-security
option where it checks for the source port <= 1023 before
allowing a mount request. If an admin has used this to make the
host OS trusted for mounts, the default iptables behaviour will
potentially allow NAT'd guests access too. This needs to be
stopped.
With this change, the iptables -t nat -L -n -v rules for the
default network will be
Chain POSTROUTING (policy ACCEPT 95 packets, 9163 bytes)
pkts bytes target prot opt in out source destination
14 840 MASQUERADE tcp -- * * 192.168.122.0/24 !192.168.122.0/24 masq ports: 1024-65535
75 5752 MASQUERADE udp -- * * 192.168.122.0/24 !192.168.122.0/24 masq ports: 1024-65535
0 0 MASQUERADE all -- * * 192.168.122.0/24 !192.168.122.0/24
* src/network/bridge_driver.c: Add masquerade rules for TCP
and UDP protocols
* src/util/iptables.c, src/util/iptables.c: Add source port
mappings for TCP & UDP protocols when masquerading.
We don't use this method of reloading rules anymore, so we can just
kill the code.
This simplifies things a lot because we no longer need to keep a
table of the rules we've added.
* src/util/iptables.c: kill iptablesReloadRules()
Long ago we tried to use Fedora's lokkit utility in order to register
our iptables rules so that 'service iptables restart' would
automatically load our rules.
There was one fatal flaw - if the user had configured iptables without
lokkit, then we would clobber that configuration by running lokkit.
We quickly disabled lokkit support, but never removed it. Let's do
that now.
The 'my virtual network stops working when I restart iptables' still
remains. For all the background on this saga, see:
https://bugzilla.redhat.com/227011
* src/util/iptables.c: remove lokkit support
* configure.in: remove --enable-lokkit
* libvirt.spec.in: remove the dirs used only for saving rules for lokkit
* src/Makefile.am: ditto
* src/libvirt_private.syms, src/network/bridge_driver.c,
src/util/iptables.h: remove references to iptablesSaveRules
* src/internal.h (ATTRIBUTE_SENTINEL): New, it's a ggc feature and
protected as such
* src/util/buf.c (virBufferStrcat): Use it.
* src/util/ebtables.c (ebtablesAddRemoveRule): Use it.
* src/util/iptables.c (iptableAddRemoveRule: Use it.
* src/util/qparams.h (new_qparam_set, append_qparams): Use it.
* docs/apibuild.py: avoid breaking the API generator with that new
internal keyword macro
