On Mon, 11 Dec 2023 13:05:20 +1100
David Gibson <david(a)gibson.dropbear.id.au> wrote:

...
  On Fri, Dec 08, 2023 at 06:49:32PM +0100, Stefano
Brivio wrote:
  If we run passt nested (a guest connected via
passt to a guest
 connected via passt to the host), the first guest (L1) typically has
 two IPv6 addresses: one formed from the prefix assigned via SLAAC,
 and another one assigned via DHCPv6 (to match the address on the
 host).   
 
 Hmm... it can't be just that there are multible IPv6 addresses here
 that's the problem.  I usually have multiple IPv6 unicast addresses on
 my laptop (one for the wifi, one for wired) and I already got that
 working.
 
 Possibly it's that there are multiple addresses on the same interface? 
Yes, the guest has a single interface and multiple addresses for it,
I'll change the commit message.

...
  But see below..
 
  When we select addresses for comparison, in this
case, we have
 multiple global unicast addresses. Selecting the first reported one
 on both host and guest is not entirely correct (in theory, the order
 might differ), but works reasonably well.   
 
 That approach seems good, in principle
 
  Use the trick from 5beef085978e ("test: Only
select a single
 interface or gateway in tests") to ask jq(1) for the first address
 returned by the query.   
 
 But that patch was selecting gateways, not local addresses, so I don't
 think  the same syntax makes sense.
 
  
 Signed-off-by: Stefano Brivio <sbrivio(a)redhat.com>
 ---
  test/passt/dhcp       | 8 ++++----
  test/passt/ndp        | 4 ++--
  test/pasta/dhcp       | 8 ++++----
  test/pasta/ndp        | 4 ++--
  test/two_guests/basic | 6 +++---
  5 files changed, 15 insertions(+), 15 deletions(-)
 
 diff --git a/test/passt/dhcp b/test/passt/dhcp
 index 7272755..b428064 100644
 --- a/test/passt/dhcp
 +++ b/test/passt/dhcp
 @@ -22,8 +22,8 @@ check	[ -n "__IFNAME__" ]
  
  test	DHCP: address
  guest	/sbin/dhclient -4 __IFNAME__
 -gout	ADDR ip -j -4 addr show|jq -rM '.[] | select(.ifname ==
"__IFNAME__").addr_info[0].local'
 -hout	HOST_ADDR ip -j -4 addr show|jq -rM '.[] | select(.ifname ==
"__HOST_IFNAME__").addr_info[0].local'
 +gout	ADDR ip -j -4 addr show|jq -rM '[.[] | select(.ifname ==
"__IFNAME__").addr_info[0].local] | .[0]'
 +hout	HOST_ADDR ip -j -4 addr show|jq -rM '[.[] | select(.ifname ==
"__HOST_IFNAME__").addr_info[0].local] | .[0]'   
 
 I'm confused by this.  The 'addr_info[0]' should already be selecting
 the first address from each interface, so the outer '.[0]' would only
 be doing something if multiple interfaces are selected, and I'm not
 quite sure why that would happen.
 
 In fact, I suspect this one was right all along...  
Right, this doesn't make sense, I just went too far with the copy and
paste. Same as for the pasta/dhcp change below. There are actually no
issues with IPv4. I'll drop those.

...
 
   check	[
"__ADDR__" = "__HOST_ADDR__" ]
  
  test	DHCP: route
 @@ -49,8 +49,8 @@ check	[ "__SEARCH__" = "__HOST_SEARCH__" ]
  
  test	DHCPv6: address
  guest	/sbin/dhclient -6 __IFNAME__
 -gout	ADDR6 ip -j -6 addr show|jq -rM '.[] | select(.ifname ==
"__IFNAME__").addr_info[] | select(.prefixlen == 128).local'
 -hout	HOST_ADDR6 ip -j -6 addr show|jq -rM '.[] | select(.ifname ==
"__HOST_IFNAME6__").addr_info[] | select(.scope ==
"global").local'
 +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").local]
  | .[0]'   
 
 ... but this one isn't, because it is .addr_info[].  Previously the
 second 'select' has picked out only one, but not in this situation.
 So here the change makes sense to me. 
Here we want to use .addr_info[] because we want to filter further on
prefixlen or scope. But once we've done that, if we have two addresses,
we have to pick one.

...
  >  check	[ "__ADDR6__" =
"__HOST_ADDR6__" ]
 >  
 >  test	DHCPv6: route
 > diff --git a/test/passt/ndp b/test/passt/ndp
 > index 6de4081..7b2dbfe 100644
 > --- a/test/passt/ndp
 > +++ b/test/passt/ndp
 > @@ -21,9 +21,9 @@ hout	HOST_IFNAME6 ip -j -6 route show|jq -rM '[.[] |
select(.dst == "default").d
 >  check	[ -n "__IFNAME__" ]
 >  
 >  test	SLAAC: prefix
 > -gout	ADDR6 ip -j -6 addr show|jq -rM '.[] | select(.ifname ==
"__IFNAME__").addr_info[] | select(.scope == "global" and .prefixlen
== 64).local'
 > +gout	ADDR6 ip -j -6 addr show|jq -rM '[.[] | select(.ifname ==
"__IFNAME__").addr_info[] | select(.scope == "global" and .prefixlen
== 64).local] | .[0]'
 >  gout	PREFIX6 sipcalc __ADDR6__/64 | grep prefix | cut -d' ' -f4
 > -hout	HOST_ADDR6 ip -j -6 addr show|jq -rM '.[] | select(.ifname ==
"__HOST_IFNAME6__").addr_info[] | select(.scope ==
"global").local'
 > +hout	HOST_ADDR6 ip -j -6 addr show|jq -rM '[.[] | select(.ifname ==
"__HOST_IFNAME6__").addr_info[] | select(.scope == "global").local] |
.[0]'
 >  hout	HOST_PREFIX6 sipcalc __HOST_ADDR6__/64 | grep prefix | cut -d' '
-f4
 >  check	[ "__PREFIX6__" = "__HOST_PREFIX6__" ]
 >  
 > diff --git a/test/pasta/dhcp b/test/pasta/dhcp
 > index 309001b..b4f6f60 100644
 > --- a/test/pasta/dhcp
 > +++ b/test/pasta/dhcp
 > @@ -20,8 +20,8 @@ check	[ -n "__IFNAME__" ]
 >  
 >  test	DHCP: address
 >  ns	/sbin/dhclient -4 --no-pid __IFNAME__
 > -nsout	ADDR ip -j -4 addr show|jq -rM '.[] | select(.ifname ==
"__IFNAME__").addr_info[0].local'
 > -hout	HOST_ADDR ip -j -4 addr show|jq -rM '.[] | select(.ifname ==
"__IFNAME__").addr_info[0].local'
 > +nsout	ADDR ip -j -4 addr show|jq -rM '[.[] | select(.ifname ==
"__IFNAME__").addr_info[0].local] | .[0]'
 > +hout	HOST_ADDR ip -j -4 addr show|jq -rM '[.[] | select(.ifname ==
"__IFNAME__").addr_info[0].local] | .[0]'
 >  check	[ __ADDR__ = __HOST_ADDR__ ]
 >  
 >  test	DHCP: route
 > @@ -36,8 +36,8 @@ check	[ __MTU__ = 65520 ]
 >  test	DHCPv6: address
 >  ns	/sbin/dhclient -6 --no-pid __IFNAME__
 >  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'
 > -hout	HOST_ADDR6 ip -j -6 addr show|jq -rM '.[] | select(.ifname ==
"__HOST_IFNAME6__").addr_info[] | select(.scope ==
"global").local'
 > +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").local] |
.[0]'
 >  check	[ __ADDR6__ = __HOST_ADDR6__ ]
 >  
 >  test	DHCPv6: route
 > diff --git a/test/pasta/ndp b/test/pasta/ndp
 > index bb33110..2a8afe6 100644
 > --- a/test/pasta/ndp
 > +++ b/test/pasta/ndp
 > @@ -21,9 +21,9 @@ ns	ip link set dev __IFNAME__ up
 >  sleep	2
 >  
 >  test	SLAAC: prefix
 > -nsout	ADDR6 ip -j -6 addr show|jq -rM '.[] | select(.ifname ==
"__IFNAME__").addr_info[] | select(.scope == "global" and .prefixlen
== 64).local'
 > +nsout	ADDR6 ip -j -6 addr show|jq -rM '[.[] | select(.ifname ==
"__IFNAME__").addr_info[] | select(.scope == "global" and .prefixlen
== 64).local] | .[0]'
 >  nsout	PREFIX6 sipcalc __ADDR6__/64 | grep prefix | cut -d' ' -f4
 > -hout	HOST_ADDR6 ip -j -6 addr show|jq -rM '.[] | select(.ifname ==
"__IFNAME__").addr_info[] | select(.scope == "global").local'
 > +hout	HOST_ADDR6 ip -j -6 addr show|jq -rM ['.[] | select(.ifname ==
"__IFNAME__").addr_info[] | select(.scope == "global").local] |
.[0]'
 >  hout	HOST_PREFIX6 sipcalc __HOST_ADDR6__/64 | grep prefix | cut -d' '
-f4
 >  check	[ "__PREFIX6__" = "__HOST_PREFIX6__" ]
 >  
 > diff --git a/test/two_guests/basic b/test/two_guests/basic
 > index 09fbd3e..fa0608b 100644
 > --- a/test/two_guests/basic
 > +++ b/test/two_guests/basic
 > @@ -39,9 +39,9 @@ test	DHCPv6: addresses
 >  sleep	2
 >  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'
 > -g2out	ADDR2_6 ip -j -6 addr show|jq -rM '.[] | select(.ifname ==
"__IFNAME2__").addr_info[] | select(.prefixlen == 128).local'
 > -hout	HOST_ADDR6 ip -j -6 addr show|jq -rM '.[] | select(.ifname ==
"__HOST_IFNAME6__").addr_info[] | select(.scope ==
"global").local'
 > +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").local] |
.[0]'
 >  check	[ "__ADDR1_6__" = "__HOST_ADDR6__" ]
 >  check	[ "__ADDR2_6__" = "__HOST_ADDR6__" ] 
-- 
Stefano