Bug 443237 - Xen IP antispoofing is not working when multiple antispoof ip addesses are specified
Xen IP antispoofing is not working when multiple antispoof ip addesses are sp...
Product: Red Hat Enterprise Linux 5
Classification: Red Hat
Component: xen (Show other bugs)
x86_64 Linux
low Severity low
: rc
: ---
Assigned To: Michal Novotny
Virtualization Bugs
Depends On:
Blocks: 514498
  Show dependency treegraph
Reported: 2008-04-19 12:28 EDT by Arturas Moskvinas
Modified: 2014-02-02 17:36 EST (History)
6 users (show)

See Also:
Fixed In Version: xen-3.0.3-115.el5
Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of:
Last Closed: 2011-01-13 17:16:11 EST
Type: ---
Regression: ---
Mount Type: ---
Documentation: ---
Verified Versions:
Category: ---
oVirt Team: ---
RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: ---

Attachments (Terms of Use)
Fix Xen IP antispoofing for multiple antispoof IP addresses (370 bytes, patch)
2010-07-21 02:00 EDT, Michal Novotny
no flags Details | Diff

External Trackers
Tracker ID Priority Status Summary Last Updated
Red Hat Product Errata RHBA-2011:0031 normal SHIPPED_LIVE xen bug fix and enhancement update 2011-01-12 10:59:24 EST

  None (edit)
Description Arturas Moskvinas 2008-04-19 12:28:20 EDT
Description of problem:
Xen supports IP antispoofing using iptables. It can also support multiple ip
antispoofing (several IP's for one interface, simply separated by spaces), but
it is not possible to have several IPs, because of the bug in
/etc/xen/scripts/vif-common.sh script.

Version-Release number of selected component (if applicable):

How reproducible:

Steps to Reproduce:
1. Create guest domain config with this network config sample: vif = [
'mac=some_mac, bridge=xenbr0, ip=10.X.X.X 10.X.X.Y' ]
2. Start domain
3. iptables -L
Actual results:
Failed iptables command is logged in /var/log/messages. iptables -L shows that
there is no FORWARD rules which will let those ip to pass through. Guest domain
has no net connectivity because packets are dropped by default forward rule.
messages log example:
Apr 19 18:21:04 somehost logger: /etc/xen/scripts/vif-bridge: iptables -A
FORWARD -m physdev --physdev-in vifXX.0 -s 10.X.X.X 10.X.X.Y -j ACCEPT failed.
If you are using iptables, this may affect networking for guest domains.

Expected results:
iptables -L should return:
-A FORWARD -s 10.X.X.X -m physdev  --physdev-in vifXX.0 -j ACCEPT 
-A FORWARD -s 10.X.X.Y -m physdev  --physdev-in vifXX.0 -j ACCEPT
other rules...
Guest domain has connectivity, packets are not dropped by default forward rules,
but accepted by rules above.

Additional info:

Bug in /etc/xen/scripts/vif-common.sh
line 106
for addr in "$ip"
    frob_iptable -s "$addr"
should be:
for addr in $ip
    frob_iptable -s "$addr"
Comment 5 Michal Novotny 2010-07-21 02:00:11 EDT
Created attachment 433305 [details]
Fix Xen IP antispoofing for multiple antispoof IP addresses

I've tried this one and it's working fine. Also, thanks for your patch, it's working fine.

Comment 11 errata-xmlrpc 2011-01-13 17:16:11 EST
An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on therefore solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.


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