[PATCH v5 2/7] test: Explicitly wait for DAD to complete on SLAAC addresses

[David Gibson <david@gibson.dropbear.id.au>]

Getting a SLAAC address takes a little while because the kernel must
complete Duplicate Address Detection (DAD) before marking the address as
ready.  In several places we have an explicit 'sleep 2' to wait for that
to complete.

Fixed length delays are never a great idea, although this one is pretty
solid.  Still, it would be better to explicitly wait for DAD to complete
in case of long delays (which might happen on slow emulated hosts, or with
heavy load), and to speed the tests up if DAD completes quicker.

Replace the fixed sleeps with a loop waiting for DAD to complete.  We do
this by looping waiting for all tentative addresses to disappear.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---
 test/passt/ndp        | 4 +++-
 test/pasta/ndp        | 3 ++-
 test/two_guests/basic | 3 ++-
 3 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/test/passt/ndp b/test/passt/ndp
index 6bf8af3..f54b8ce 100644
--- a/test/passt/ndp
+++ b/test/passt/ndp
@@ -16,7 +16,9 @@ htools	ip jq sipcalc grep cut
 
 test	Interface name
 gout	IFNAME ip -j link show | jq -rM '.[] | select(.link_type == "ether").ifname'
-guest	ip link set dev __IFNAME__ up && sleep 2
+guest	ip link set dev __IFNAME__ up
+# Wait for DAD to complete
+guest	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]'
 check	[ -n "__IFNAME__" ]
 
diff --git a/test/pasta/ndp b/test/pasta/ndp
index d45ff7b..c59627f 100644
--- a/test/pasta/ndp
+++ b/test/pasta/ndp
@@ -18,7 +18,8 @@ test	Interface name
 nsout	IFNAME ip -j link show | jq -rM '.[] | select(.link_type == "ether").ifname'
 check	[ -n "__IFNAME__" ]
 ns	ip link set dev __IFNAME__ up
-sleep	2
+# Wait for DAD to complete
+ns	while ip -j -6 addr show tentative | jq -e '.[].addr_info'; do sleep 0.1; done
 
 test	SLAAC: prefix
 nsout	ADDR6 ip -j -6 addr show|jq -rM '[.[] | select(.ifname == "__IFNAME__").addr_info[] | select(.scope == "global" and .prefixlen == 64).local] | .[0]'
diff --git a/test/two_guests/basic b/test/two_guests/basic
index 4d49e85..ac50ff8 100644
--- a/test/two_guests/basic
+++ b/test/two_guests/basic
@@ -36,7 +36,8 @@ check	[ "__ADDR2__" = "__HOST_ADDR__" ]
 
 test	DHCPv6: addresses
 # Link is up now, wait for DAD to complete
-sleep	2
+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
 guest1	/sbin/dhclient -6 __IFNAME1__
 guest2	/sbin/dhclient -6 __IFNAME2__
 g1out	ADDR1_6 ip -j -6 addr show|jq -rM '[.[] | select(.ifname == "__IFNAME1__").addr_info[] | select(.prefixlen == 128).local] | .[0]'
-- 
@@ -36,7 +36,8 @@ check	[ "__ADDR2__" = "__HOST_ADDR__" ]
 
 test	DHCPv6: addresses
 # Link is up now, wait for DAD to complete
-sleep	2
+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
 guest1	/sbin/dhclient -6 __IFNAME1__
 guest2	/sbin/dhclient -6 __IFNAME2__
 g1out	ADDR1_6 ip -j -6 addr show|jq -rM '[.[] | select(.ifname == "__IFNAME1__").addr_info[] | select(.prefixlen == 128).local] | .[0]'
-- 
2.47.0