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Fix interface IP address lookup in dual-stack mode #2283

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Merged
merged 1 commit into from
Oct 1, 2025
Merged

Fix interface IP address lookup in dual-stack mode #2283

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23 changes: 14 additions & 9 deletions pkg/ipmatch/match.go
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Original file line number Diff line number Diff line change
Expand Up @@ -247,17 +247,22 @@ func LookupExtIface(ifname string, ifregexS string, ifcanreach string, ipStack i
return nil, fmt.Errorf("failed to find IPv6 address for interface %s", iface.Name)
}
ifaceV6Addr = ifaceV6Addrs[0]
} else if ipStack == dualStack && ifaceAddr == nil && ifaceV6Addr == nil {
ifaceAddrs, err = ip.GetInterfaceIP4Addrs(iface)
if err != nil || len(ifaceAddrs) == 0 {
return nil, fmt.Errorf("failed to find IPv4 address for interface %s", iface.Name)
} else if ipStack == dualStack {
if ifaceAddr == nil {
ifaceAddrs, err = ip.GetInterfaceIP4Addrs(iface)
if err != nil || len(ifaceAddrs) == 0 {
return nil, fmt.Errorf("failed to find IPv4 address for interface %s", iface.Name)
}
ifaceAddr = ifaceAddrs[0]
}
ifaceAddr = ifaceAddrs[0]
ifaceV6Addrs, err = ip.GetInterfaceIP6Addrs(iface)
if err != nil || len(ifaceV6Addrs) == 0 {
return nil, fmt.Errorf("failed to find IPv6 address for interface %s", iface.Name)

if ifaceV6Addr == nil {
ifaceV6Addrs, err = ip.GetInterfaceIP6Addrs(iface)
if err != nil || len(ifaceV6Addrs) == 0 {
return nil, fmt.Errorf("failed to find IPv6 address for interface %s", iface.Name)
}
ifaceV6Addr = ifaceV6Addrs[0]
}
ifaceV6Addr = ifaceV6Addrs[0]
}

if ifaceAddr != nil {
Expand Down
19 changes: 19 additions & 0 deletions pkg/ipmatch/match_test.go
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Original file line number Diff line number Diff line change
Expand Up @@ -37,6 +37,7 @@ func TestLookupExtIface(t *testing.T) {
execOrFail("sudo", "ip", "addr", "add", "172.16.30.18", "dev", "dummy0")
execOrFail("sudo", "ip", "addr", "add", "172.16.31.200", "dev", "dummy0")
execOrFail("sudo", "ip", "addr", "add", "172.16.32.100", "dev", "dummy0")
execOrFail("sudo", "ip", "addr", "add", "2001:db8::1/64", "dev", "dummy0")
execOrFail("sudo", "ip", "link", "set", "dummy0", "up")
execOrFail("sudo", "ip", "route", "add", "172.16.32.254", "via", "172.16.32.100", "dev", "dummy0")

Expand Down Expand Up @@ -105,6 +106,24 @@ func TestLookupExtIface(t *testing.T) {
}
})

t.Run("ByIPv4DualStack", func(t *testing.T) {
backendInterface, err := LookupExtIface("172.16.30.18", "", "", dualStack, PublicIPOpts{})
if err != nil {
t.Fatal(err)
}
t.Logf("backendInterface=%+v iface=%+v", backendInterface, *backendInterface.Iface)

if backendInterface.Iface.Name != "dummy0" {
t.Fatalf("iface name not equal, expected=%v actual=%v", "dummy0", backendInterface.Iface.Name)
}
if backendInterface.IfaceAddr.String() != "172.16.30.18" {
t.Fatalf("iface addr not equal, expected=%v actual=%v", "172.16.30.18", backendInterface.IfaceAddr.String())
}
if backendInterface.IfaceV6Addr.String() != "2001:db8::1/64" {
t.Fatalf("iface addr not equal, expected=%v actual=%v", "2001:db8::1/64", backendInterface.IfaceV6Addr.String())
}
})

t.Run("ByIfRegexMatchPublicIPv4", func(t *testing.T) {
expectedIfaceName := "dummy0"
expectedIP := "172.16.30.18"
Expand Down
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