git: b5519c449337 - main - hyperv: Configure IPv6 when setting up VF failover

The branch main has been updated by kbowling:

URL: https://cgit.FreeBSD.org/src/commit/?id=b5519c449337fea1d5cbaf2f0ba11cafa36338ee

commit b5519c449337fea1d5cbaf2f0ba11cafa36338ee
Author:     Kevin Bowling <kbowling@FreeBSD.org>
AuthorDate: 2026-09-15 01:48:25 +0000
Commit:     Kevin Bowling <kbowling@FreeBSD.org>
CommitDate: 2026-09-15 02:03:24 +0000

    hyperv: Configure IPv6 when setting up VF failover
    
    The default VF-up script moves IPv4 configuration from the synthetic
    interface to a failover lagg, but leaves IPv6 unconfigured on the lagg.
    Adding the synthetic interface as a member can remove its IPv6 addresses,
    so deleting the remaining member addresses is not sufficient.
    
    Stop accepting router advertisements on the synthetic interface before
    adding it to the lagg.  Leave its link-local address and IPv6 enable state
    in place for lagg's address, prefix and default-router cleanup, then disable
    IPv6 and explicitly remove any remaining addresses.  This also covers
    members without a link-local address or with IPv6 already disabled.
    
    Replay the synthetic interface's IPv6 rc.conf configuration on the lagg,
    including aliases, prefix-derived addresses and legacy configuration names.
    Remap the variables in a subshell and reuse network.subr's IPv6 helpers.
    For SLAAC, solicit fresh router advertisements rather than copying learned
    addresses as permanent ones.  Configure IPv6 independently of the IPv4
    DHCP/static choice, and leave existing laggs alone on repeated invocation.
    Custom DHCPv6 clients and interface-scoped static routes still require the
    per-interface setup hook.
    
    Fixes: c68595695679 ("hyperv: Add VF bringup scripts and devd rules.")
    MFC after:      2 weeks
    Sponsored by:   BBOX.io
---
 contrib/hyperv/tools/scripts/hyperv_vfup | 80 ++++++++++++++++++++++++++++++--
 1 file changed, 75 insertions(+), 5 deletions(-)

diff --git a/contrib/hyperv/tools/scripts/hyperv_vfup b/contrib/hyperv/tools/scripts/hyperv_vfup
index e637c6c32e02..34689a08d201 100644
--- a/contrib/hyperv/tools/scripts/hyperv_vfup
+++ b/contrib/hyperv/tools/scripts/hyperv_vfup
@@ -5,6 +5,56 @@
 
 load_rc_config netif
 
+# Configure IPv6 on the lagg using the synthetic interface's rc.conf values.
+# Keep the variable remapping local to this subshell.
+ipv6_lagg_up()
+(
+	local var value suffix ifconfig_args
+
+	afexists inet6 || return 0
+	if ! ipv6if $hn && ! checkyesno ipv6_activate_all_interfaces
+	then
+		return 0
+	fi
+
+	for var in `list_vars "ifconfig_${hn}_*"`
+	do
+		suffix=${var#ifconfig_${hn}_}
+		case $suffix in
+		ipv6|alias*)
+			eval value=\"\$$var\"
+			setvar "ifconfig_${lagg}_${suffix}" "$value"
+			;;
+		esac
+	done
+	value=`get_if_var $hn ipv6_prefix_IF`
+	setvar "ipv6_prefix_${lagg}" "$value"
+	for var in `list_vars "ipv6_ifconfig_${hn}"` \
+	    `list_vars "ipv6_ifconfig_${hn}_alias*"`
+	do
+		suffix=${var#ipv6_ifconfig_${hn}}
+		eval value=\"\$$var\"
+		setvar "ipv6_ifconfig_${lagg}${suffix}" "$value"
+	done
+	ipv6_network_interfaces="$ipv6_network_interfaces $lagg"
+
+	ifconfig $lagg inet6 -ifdisabled up || return 1
+	for ifconfig_args in "`ifconfig_getargs $lagg ipv6`" \
+	    "`get_if_var $lagg ipv6_ifconfig_IF`"
+	do
+		[ -n "$ifconfig_args" ] || continue
+		# Accept legacy values without the address-family keyword.
+		case $ifconfig_args in
+		inet6|inet6[[:space:]]*) ;;
+		*) ifconfig_args="inet6 $ifconfig_args" ;;
+		esac
+		ifconfig $lagg $ifconfig_args || return 1
+	done
+	ipv6_up $lagg
+	ipv6_accept_rtadv_up $lagg
+	return 0
+)
+
 #
 # Customized per-interface setup, e.g. hyperv_vfup.hn1
 #
@@ -52,10 +102,31 @@ then
 	fi
 
 	#
-	# Configure laggX (failover), add hnX and VF to it.
+	# Stop accepting advertisements on hnX.  Leave IPv6 enabled and its
+	# link-local address in place until lagg has purged the member's
+	# IPv6 addresses, prefixes, and default routers.
 	#
-	ifconfig $lagg laggproto failover laggport $hn laggport $vf
-	ifconfig $lagg inet6 no_dad
+	if afexists inet6
+	then
+		ifconfig $hn inet6 -accept_rtadv || exit 1
+	fi
+
+	# Configure laggX (failover), add hnX and VF to it.
+	ifconfig $lagg laggproto failover laggport $hn laggport $vf || exit 1
+	if afexists inet6
+	then
+		# lagg does not purge an IPv6-disabled member or one without a
+		# link-local address.  Disable IPv6 and remove any addresses left.
+		# SLAAC addresses are relearned on lagg, not copied as permanent.
+		ifconfig $hn inet6 ifdisabled || exit 1
+		inet6_status=`ifconfig $hn inet6` || exit 1
+		for addr in `printf '%s\n' "$inet6_status" | \
+		    awk '$1 == "inet6" { print $2 }'`
+		do
+			ifconfig $hn inet6 "$addr" -alias || exit 1
+		done
+		ifconfig $lagg inet6 no_dad
+	fi
 
 	#
 	# Stop dhclient on hnX, if any.
@@ -74,8 +145,6 @@ then
 	# Enumerate addresses; an empty ifconfig -alias may return success.
 	ipv4_down $hn
 
-	# TODO: Remove IPv6 addresses on hnX
-
 	#
 	# Use hnX's configuration for laggX
 	#
@@ -100,6 +169,7 @@ then
 			ifconfig $lagg $ifconfig_args
 		fi
 	fi
+	ipv6_lagg_up || exit 1
 else
 	#
 	# laggX exists.  Check whether VF was there or not.