nwfilter: let qemu's after-migration packet pass

Qemu currently sends an Ethernet packet with protocol id 0x835 once a VM
was successfully migrated. The content of the packet looks like a
gratuitous RARP, just with the wrong protocol ID, which should be
0x8035. I wrote some filters to let either one of the packets pass and
am adapting the clean-traffic sample filter to use it. I am also
doing some changes on the existing ARP filter which was lacking a
test for source MAC address.
This commit is contained in:
Stefan Berger 2010-04-27 14:50:35 -04:00
parent 71f99af5a4
commit ed7813d28d
6 changed files with 45 additions and 6 deletions

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@ -11,7 +11,10 @@ FILTERS = \
no-ip-spoofing.xml \
no-mac-broadcast.xml \
no-mac-spoofing.xml \
no-other-l2-traffic.xml
no-other-l2-traffic.xml \
no-other-rarp-traffic.xml \
qemu-announce-self.xml \
qemu-announce-self-rarp.xml
EXTRA_DIST=$(FILTERS)

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@ -14,4 +14,7 @@
<!-- preventing any other traffic than IPv4 and ARP -->
<filterref filter='no-other-l2-traffic'/>
<!-- allow qemu to send a self-announce upon migration end -->
<filterref filter='qemu-announce-self'/>
</filter>

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@ -1,27 +1,30 @@
<filter name='no-arp-spoofing' chain='arp'>
<uuid>f88f1932-debf-4aa1-9fbe-f10d3aa4bc95</uuid>
<rule action='drop' direction='out' priority='300' >
<mac match='no' srcmacaddr='$MAC'/>
</rule>
<!-- no arp spoofing -->
<!-- drop if ipaddr or macaddr does not belong to guest -->
<rule action='drop' direction='out' priority='400' >
<rule action='drop' direction='out' priority='350' >
<arp match='no' arpsrcmacaddr='$MAC'/>
</rule>
<rule action='drop' direction='out' priority='400' >
<arp match='no' arpsrcipaddr='$IP' />
</rule>
<!-- drop if ipaddr or macaddr odes not belong to guest -->
<rule action='drop' direction='in' priority='400' >
<rule action='drop' direction='in' priority='450' >
<arp match='no' arpdstmacaddr='$MAC'/>
<arp opcode='reply'/>
</rule>
<rule action='drop' direction='in' priority='400' >
<rule action='drop' direction='in' priority='500' >
<arp match='no' arpdstipaddr='$IP' />
</rule>
<!-- accept only request or reply packets -->
<rule action='accept' direction='inout' priority='500' >
<rule action='accept' direction='inout' priority='600' >
<arp opcode='request'/>
</rule>
<rule action='accept' direction='inout' priority='500' >
<rule action='accept' direction='inout' priority='650' >
<arp opcode='reply'/>
</rule>
<!-- drop everything else -->

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@ -0,0 +1,3 @@
<filter name='no-other-rarp-traffic' chain='rarp'>
<rule action='drop' direction='inout' priority='1000'/>
</filter>

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@ -0,0 +1,14 @@
<filter name='qemu-announce-self-rarp' chain='rarp'>
<rule action='accept' direction='out' priority='500'>
<rarp opcode='Request_Reverse'
srcmacaddr='$MAC' dstmacaddr='ff:ff:ff:ff:ff:ff'
arpsrcmacaddr='$MAC' arpdstmacaddr='$MAC'
arpsrcipaddr='0.0.0.0' arpdstipaddr='0.0.0.0'/>
</rule>
<rule action='accept' direction='in' priority='500'>
<rarp opcode='Request_Reverse'
dstmacaddr='ff:ff:ff:ff:ff:ff'
arpsrcmacaddr='$MAC' arpdstmacaddr='$MAC'
arpsrcipaddr='0.0.0.0' arpdstipaddr='0.0.0.0'/>
</rule>
</filter>

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@ -0,0 +1,13 @@
<filter name='qemu-announce-self' chain='root'>
<!-- as of 4/26/2010 qemu sends out a bogus packet with
wrong rarp protocol ID -->
<!-- accept what is being sent now -->
<rule action='accept' direction='out'>
<mac protocolid='0x835'/>
</rule>
<!-- accept if it was changed to rarp -->
<filterref filter='qemu-announce-self-rarp'/>
<filterref filter='no-other-rarp-traffic'/>
</filter>