chore(netlink): separate linux only and OS independent code

- Move `Addr` and its `String` method to `types.go`
- Move `IsWireguardSupported` to `wireguard.go` to have `family.go` OS independant
- Remove dependency on vishvananda/netlink in `ipv6.go`
- Move `Link` to `types.go`
- Move `Route` to `types.go`
- Move `Rule` and its `String` method to `types.go`

internal/netlink/address.go

@@ -1,19 +1,9 @@
 package netlink
 
 import (
-	"net/netip"
-
 	"github.com/vishvananda/netlink"
 )
 
-type Addr struct {
-	Network netip.Prefix
-}
-
-func (a Addr) String() string {
-	return a.Network.String()
-}
-
 func (n *NetLink) AddrList(link Link, family int) (
 	addresses []Addr, err error) {
 	netlinkLink := linkToNetlinkLink(&link)

internal/netlink/family.go

@@ -2,8 +2,6 @@ package netlink
 
 import (
 	"fmt"
-
-	"github.com/vishvananda/netlink"
 )
 
 const (
@@ -24,16 +22,3 @@ func FamilyToString(family int) string {
 		return fmt.Sprint(family)
 	}
 }
-
-func (n *NetLink) IsWireguardSupported() (ok bool, err error) {
-	families, err := netlink.GenlFamilyList()
-	if err != nil {
-		return false, fmt.Errorf("listing gen 1 families: %w", err)
-	}
-	for _, family := range families {
-		if family.Name == "wireguard" {
-			return true, nil
-		}
-	}
-	return false, nil
-}

internal/netlink/ipv6.go

@@ -2,8 +2,6 @@ package netlink
 
 import (
 	"fmt"
-
-	"github.com/vishvananda/netlink"
 )
 
 func (n *NetLink) IsIPv6Supported() (supported bool, err error) {
@@ -15,7 +13,7 @@ func (n *NetLink) IsIPv6Supported() (supported bool, err error) {
 	var totalRoutes uint
 	for _, link := range links {
 		link := link
-		routes, err := n.RouteList(&link, netlink.FAMILY_V6)
+		routes, err := n.RouteList(&link, FamilyV6)
 		if err != nil {
 			return false, fmt.Errorf("listing IPv6 routes for link %s: %w",
 				link.Name, err)

internal/netlink/link.go

@@ -2,14 +2,6 @@ package netlink
 
 import "github.com/vishvananda/netlink"
 
-type Link struct {
-	Type      string
-	Name      string
-	Index     int
-	EncapType string
-	MTU       uint16
-}
-
 func (n *NetLink) LinkList() (links []Link, err error) {
 	netlinkLinks, err := netlink.LinkList()
 	if err != nil {

internal/netlink/route.go

@@ -1,22 +1,9 @@
 package netlink
 
 import (
-	"net/netip"
-
 	"github.com/vishvananda/netlink"
 )
 
-type Route struct {
-	LinkIndex int
-	Dst       netip.Prefix
-	Src       netip.Addr
-	Gw        netip.Addr
-	Priority  int
-	Family    int
-	Table     int
-	Type      int
-}
-
 func (n *NetLink) RouteList(link *Link, family int) (
 	routes []Route, err error) {
 	netlinkLink := linkToNetlinkLink(link)

internal/netlink/rule.go

@@ -1,37 +1,9 @@
 package netlink
 
 import (
-	"fmt"
-	"net/netip"
-
 	"github.com/vishvananda/netlink"
 )
 
-type Rule struct {
-	Priority int
-	Family   int
-	Table    int
-	Mark     int
-	Src      netip.Prefix
-	Dst      netip.Prefix
-	Invert   bool
-}
-
-func (r Rule) String() string {
-	from := "all"
-	if r.Src.IsValid() {
-		from = r.Src.String()
-	}
-
-	to := "all"
-	if r.Dst.IsValid() {
-		to = r.Dst.String()
-	}
-
-	return fmt.Sprintf("ip rule %d: from %s to %s table %d",
-		r.Priority, from, to, r.Table)
-}
-
 func NewRule() Rule {
 	// defaults found from netlink.NewRule() for fields we use,
 	// the rest of the defaults is set when converting from a `Rule`

internal/netlink/types.go

@@ -0,0 +1,58 @@
+package netlink
+
+import (
+	"fmt"
+	"net/netip"
+)
+
+type Addr struct {
+	Network netip.Prefix
+}
+
+func (a Addr) String() string {
+	return a.Network.String()
+}
+
+type Link struct {
+	Type      string
+	Name      string
+	Index     int
+	EncapType string
+	MTU       uint16
+}
+
+type Route struct {
+	LinkIndex int
+	Dst       netip.Prefix
+	Src       netip.Addr
+	Gw        netip.Addr
+	Priority  int
+	Family    int
+	Table     int
+	Type      int
+}
+
+type Rule struct {
+	Priority int
+	Family   int
+	Table    int
+	Mark     int
+	Src      netip.Prefix
+	Dst      netip.Prefix
+	Invert   bool
+}
+
+func (r Rule) String() string {
+	from := "all"
+	if r.Src.IsValid() {
+		from = r.Src.String()
+	}
+
+	to := "all"
+	if r.Dst.IsValid() {
+		to = r.Dst.String()
+	}
+
+	return fmt.Sprintf("ip rule %d: from %s to %s table %d",
+		r.Priority, from, to, r.Table)
+}

internal/netlink/wireguard.go

@@ -0,0 +1,20 @@
+package netlink
+
+import (
+	"fmt"
+
+	"github.com/vishvananda/netlink"
+)
+
+func (n *NetLink) IsWireguardSupported() (ok bool, err error) {
+	families, err := netlink.GenlFamilyList()
+	if err != nil {
+		return false, fmt.Errorf("listing gen 1 families: %w", err)
+	}
+	for _, family := range families {
+		if family.Name == "wireguard" {
+			return true, nil
+		}
+	}
+	return false, nil
+}