test: Wait for DAD on DHCPv6 addresses

After running dhclient -6 we expect the DHCPv6 assigned address to be
immediately usable.  That's true with the Fedora dhclient-script (and the
upstream ISC DHCP one), however it's not true with the Debian
dhclient-script.  The Debian script can complete with the address still
in "tentative" state, and the address won't be usable until Duplicate
Address Detection (DAD) completes.  That's arguably a bug in Debian (see
link below), but for the time being we need to work around it anyway.

We usually get away with this, because by the time we do anything where the
address matters, DAD has completed.  However, it's not robust, so we should
explicitly wait for DAD to complete when we get an DHCPv6 address.

Link: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1085231

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>

test/passt/dhcp

@@ -49,6 +49,8 @@ check	[ "__SEARCH__" = "__HOST_SEARCH__" ]
 
 test	DHCPv6: address
 guest	/sbin/dhclient -6 __IFNAME__
+# Wait for DAD to complete
+guest	while ip -j -6 addr show tentative | jq -e '.[].addr_info'; do sleep 0.1; done
 gout	ADDR6 ip -j -6 addr show|jq -rM '[.[] | select(.ifname == "__IFNAME__").addr_info[] | select(.prefixlen == 128).local] | .[0]'
 hout	HOST_ADDR6 ip -j -6 addr show|jq -rM '[.[] | select(.ifname == "__HOST_IFNAME6__").addr_info[] | select(.scope == "global" and .deprecated != true).local] | .[0]'
 check	[ "__ADDR6__" = "__HOST_ADDR6__" ]

test/passt_in_ns/dhcp

@@ -52,6 +52,8 @@ check	[ "__SEARCH__" = "__HOST_SEARCH__" ]
 
 test	DHCPv6: address
 guest	/sbin/dhclient -6 __IFNAME__
+# Wait for DAD to complete
+guest	while ip -j -6 addr show tentative | jq -e '.[].addr_info'; do sleep 0.1; done
 gout	ADDR6 ip -j -6 addr show|jq -rM '[.[] | select(.ifname == "__IFNAME__").addr_info[] | select(.prefixlen == 128).local] | .[0]'
 hout	HOST_ADDR6 ip -j -6 addr show|jq -rM '[.[] | select(.ifname == "__HOST_IFNAME6__").addr_info[] | select(.scope == "global" and .deprecated != true).local] | .[0]'
 check	[ "__ADDR6__" = "__HOST_ADDR6__" ]

test/pasta/dhcp

@@ -35,6 +35,8 @@ check	[ __MTU__ = 65520 ]
 
 test	DHCPv6: address
 ns	/sbin/dhclient -6 --no-pid __IFNAME__
+# Wait for DAD to complete
+ns	while ip -j -6 addr show tentative | jq -e '.[].addr_info'; do sleep 0.1; done
 hout	HOST_IFNAME6 ip -j -6 route show|jq -rM '[.[] | select(.dst == "default").dev] | .[0]'
 nsout	ADDR6 ip -j -6 addr show|jq -rM '[.[] | select(.ifname == "__IFNAME__").addr_info[] | select(.prefixlen == 128).local] | .[0]'
 hout	HOST_ADDR6 ip -j -6 addr show|jq -rM '[.[] | select(.ifname == "__HOST_IFNAME6__").addr_info[] | select(.scope == "global" and .deprecated != true).local] | .[0]'

test/perf/passt_tcp

@@ -116,6 +116,8 @@ iperf3k	ns
 # Reducing MTU below 1280 deconfigures IPv6, get our address back
 guest	dhclient -6 -x
 guest	dhclient -6 __IFNAME__
+# Wait for DAD to complete
+guest	while ip -j -6 addr show tentative | jq -e '.[].addr_info'; do sleep 0.1; done
 
 tl	TCP RR latency over IPv4: guest to host
 lat	-

test/two_guests/basic

@@ -40,6 +40,9 @@ guest1	while ip -j -6 addr show tentative | jq -e '.[].addr_info'; do sleep 0.1;
 guest2	while ip -j -6 addr show tentative | jq -e '.[].addr_info'; do sleep 0.1; done
 guest1	/sbin/dhclient -6 __IFNAME1__
 guest2	/sbin/dhclient -6 __IFNAME2__
+# Wait for DAD to complete on the DHCP address
+guest1	while ip -j -6 addr show tentative | jq -e '.[].addr_info'; do sleep 0.1; done
+guest2	while ip -j -6 addr show tentative | jq -e '.[].addr_info'; do sleep 0.1; done
 g1out	ADDR1_6 ip -j -6 addr show|jq -rM '[.[] | select(.ifname == "__IFNAME1__").addr_info[] | select(.prefixlen == 128).local] | .[0]'
 g2out	ADDR2_6 ip -j -6 addr show|jq -rM '[.[] | select(.ifname == "__IFNAME2__").addr_info[] | select(.prefixlen == 128).local] | .[0]'
 hout	HOST_ADDR6 ip -j -6 addr show|jq -rM '[.[] | select(.ifname == "__HOST_IFNAME6__").addr_info[] | select(.scope == "global" and .deprecated != true).local] | .[0]'