Red Hat Bugzilla – Bug 245866
/etc/xen/scripts/network-bridge cannot handle aliased addresses
Last modified: 2008-05-21 11:19:44 EDT
Description of problem: When using bridged networking with Xen, the /etc/xen/scripts/network-bridge script that is run doesn't handle aliased addresses on ${netdev} properly, and thus leaves networking in a broken state. Version-Release number of selected component (if applicable): xen-3.0.3-25.0.3.el5 How reproducible: Every time Steps to Reproduce: 1. Add an aliased address on the network device that is to be bridged. E.g. with the following: ip addr add 192.168.1.5/24 dev eth0 label eth0:00 2. Configure xen to use bridged networking by setting '(network-script network-bridge)' in /etc/xen/xend-config.sxp 3. Start the xend service Actual results: The script attempts to add the aliased address to the physical device eth0:00 which is actually just the label, hence the 'ip addr add' command fails. The simplistic regexes used don't account for aliases. Expected results: Aliased addresses should be correctly added to the virtual network device. Additional info: The bug is in the transfer_addrs() function around line 109.
The following patch seems to work: --- network-bridge.orig 2007-06-27 18:51:52.000000000 +1000 +++ network-bridge 2007-06-27 18:52:15.000000000 +1000 @@ -109,7 +109,8 @@ ip addr show dev ${src} | egrep '^ *inet ' | sed -e " s/inet/ip addr add/ s@\([0-9]\+\.[0-9]\+\.[0-9]\+\.[0-9]\+/[0-9]\+\)@\1@ -s/${src}/dev ${dst}/ +s/${src}/dev ${dst} label ${dst}/ +s/secondary// " | sh -e # Remove automatic routes on destination device ip route list | sed -ne "
VLAN interfaces also do not appear to work. They are not handled by the script at all and hence when $netdev is renamed to $pdev, the vlan interfaces become $netdev.vid@$pdev. E.g. eth0.444@eth0 becomes eth0.444@peth0 when it should be recreated as eth0.444@eth0 (when eth0 is the virtual interface).
This request was evaluated by Red Hat Product Management for inclusion in a Red Hat Enterprise Linux maintenance release. Product Management has requested further review of this request by Red Hat Engineering, for potential inclusion in a Red Hat Enterprise Linux Update release for currently deployed products. This request is not yet committed for inclusion in an Update release.
The patch looks right to me and I've given it a small bit of testing and it does what it says on the tin. I'd like to get it upstream before including in RHEL 5.2, though. reporter: do you want to submit the patch upstream to xen-devel@lists.xensource.com or shall I? Oh, and btw - the vlan issue is logged separately in bug #337651 if you want to add your input there.
Mark, maybe it'd be best if you submit the patch since you probably have some history with them. It is more likely to be accepted.
Okay, patch submitted upstream: http://lists.xensource.com/archives/html/xen-devel/2008-01/msg00024.html The hold-up was that, in my testing, the alias label seemed to get changed so that e.g. the alias would be "eth0:2" rather than "eth0:00" after network-bridge was run. This turned out to be a kernel bug: http://marc.info/?l=linux-netdev&m=119937651627280&w=2 I don't think the kernel bug is that important, though - the important thing is that the alias's address gets transfered.
Fix has been accepted upstream for 3.2.0. Easier steps to reproduce: 1) Boot with kernel-xen, but with xend disabled 2) Run system-config-network, then New->Ethernet->eth0-> set IP->OK->Edit->Activate when parent starts->OK->Activate, or just $> cat > /etc/sysconfig/network-scripts/ifcfg-eth0:1 <<EOF IPADDR=foo ONPARENT=yes EOF 3) modprobe netloop 4) /etc/xen/script/network-bridge start Without the patch, network-bridge should fail with: Error: either "local" is duplicate, or "secondary" is a garbage. With the patch, network-bridge should succeed and you should see that the eth0:1 device is still configured after it has run.
Created attachment 291176 [details] xen-netdev-alias.patch
Re-assigning to Dan to pull into the 5.2 Xen RPM
Fix built: $ brew latest-pkg dist-5E-qu-candidate xen Build Tag Built by ---------------------------------------- -------------------- ---------------- xen-3.0.3-44.el5 dist-5E-qu-candidate berrange * Fri Jan 11 2008 Daniel P. Berrange <berrange@redhat.com> - 3.0.3-44.el5 - Deal with network device aliases (rhbz#245866)
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 the 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. http://rhn.redhat.com/errata/RHBA-2008-0305.html