testenv: rework veth creating and config

Instead of creating the veth in the root namespace and then moving and
renaming it, just create it directly in the target namespace with the right
name from the beginning. This requires a bit of rework of the settings
afterwards, but should hopefully fix any inconsistency issues such as the
MAC address issue reported in #159.

Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>

Author: tohojo

testenv/testenv.sh

@@ -160,7 +160,15 @@ cleanup()
 iface_macaddr()
 {
     local iface="$1"
-    ip -br link show dev "$iface" | awk '{print $3}'
+    local ns="${2:-}"
+    local output
+
+    if [ -n "$ns" ]; then
+        output=$(ip -br -n "$ns" link show dev "$iface")
+    else
+        output=$(ip -br link show dev "$iface")
+    fi
+    echo "$output" | awk '{print $3}'
 }
 
 set_sysctls()
@@ -215,27 +223,25 @@ setup()
     fi
 
     ip netns add "$NS"
-    ip link add dev "$NS" type veth peer name "$PEERNAME"
+    ip link add dev "$NS" type veth peer name veth0 netns "$NS"
+
     OUTSIDE_MAC=$(iface_macaddr "$NS")
-    INSIDE_MAC=$(iface_macaddr "$PEERNAME")
-    set_sysctls $NS
+    INSIDE_MAC=$(iface_macaddr veth0 "$NS")
 
-    ethtool -K "$NS" rxvlan off txvlan off
-    ethtool -K "$PEERNAME" rxvlan off txvlan off
-    ip link set dev "$PEERNAME" netns "$NS"
+    set_sysctls $NS
     ip link set dev "$NS" up
     ip addr add dev "$NS" "${OUTSIDE_IP6}/${IP6_PREFIX_SIZE}"
+    ethtool -K "$NS" rxvlan off txvlan off
+    # Prevent neighbour queries on the link
+    ip neigh add "$INSIDE_IP6" lladdr "$INSIDE_MAC" dev "$NS" nud permanent
 
-    ip -n "$NS" link set dev "$PEERNAME" name veth0
+    set_sysctls veth0 "$NS"
     ip -n "$NS" link set dev lo up
     ip -n "$NS" link set dev veth0 up
-    set_sysctls veth0 "$NS"
     ip -n "$NS" addr add dev veth0 "${INSIDE_IP6}/${IP6_PREFIX_SIZE}"
-
+    ip netns exec "$NS" ethtool -K veth0 rxvlan off txvlan off
     # Prevent neighbour queries on the link
-    ip neigh add "$INSIDE_IP6" lladdr "$INSIDE_MAC" dev "$NS" nud permanent
     ip -n "$NS" neigh add "$OUTSIDE_IP6" lladdr "$OUTSIDE_MAC" dev veth0 nud permanent
-
     # Add route for whole test subnet, to make it easier to communicate between
     # namespaces
     ip -n "$NS" route add "${IP6_SUBNET}::/$IP6_FULL_PREFIX_SIZE" via "$OUTSIDE_IP6" dev veth0