dhcp checksum offload workaround

gistfile1.diff

diff --git a/modules/vpssd/templates/compute_firewall.erb b/modules/vpssd/templates/compute_firewall.erb
index 5b69f24..89a7f80 100644
--- a/modules/vpssd/templates/compute_firewall.erb
+++ b/modules/vpssd/templates/compute_firewall.erb
@@ -6,20 +6,27 @@
 :POSTROUTING ACCEPT [0:0]
 COMMIT
 # Completed on Sat Oct  6 19:51:27 2012
 # Generated by iptables-save v1.4.12 on Sat Oct  6 19:51:27 2012
 *mangle
 :PREROUTING ACCEPT [0:0]
 :INPUT ACCEPT [0:0]
 :FORWARD ACCEPT [0:0]
 :OUTPUT ACCEPT [0:0]
 :POSTROUTING ACCEPT [0:0]
+
+# fix checksums for DHCP, since guest offloading the computation to the host
+# does not actually set the field when the DHCP client is on the same compute
+# node as the DHCP server
+-A POSTROUTING -p udp -m udp --dport 67 -j CHECKSUM --checksum-fill
+-A POSTROUTING -p udp -m udp --sport 67 -j CHECKSUM --checksum-fill
+
 COMMIT
 # Completed on Sat Oct  6 19:51:27 2012
 # Generated by iptables-save v1.4.12 on Sat Oct  6 19:51:27 2012
 *filter
 :INPUT ACCEPT [0:0]
 :FORWARD ACCEPT [0:0]
 :OUTPUT ACCEPT [0:0]
 :input - [0:0]
 :forward - [0:0]
 :reject - [0:0]