Pass Slice by reference, not value

cmd/app/main.go

@@ -201,13 +201,13 @@ func handleRouteEvents(routeSubChan <-chan netlink.RouteUpdate, filterOptions Fi
 			}
 
 			// Check if other peer already has exact same dst
-			if peer, err := wgChecks.PeerByIPNet(wgDevice.Peers, *route.Dst); err == nil {
+			if peer, err := wgChecks.PeerByIPNet(&wgDevice.Peers, route.Dst); err == nil {
 				logger.Warn.Printf("dst-IPNet already set for Peer '%s', ignoring", peer.PublicKey)
 				continue
 			}
 
 			// Get peer containing gateway-addr
-			peer, err := wgChecks.PeerByIP(wgDevice.Peers, route.Gw)
+			peer, err := wgChecks.PeerByIP(&wgDevice.Peers, &route.Gw)
 			if(err != nil){
 				logger.Warn.Printf("No peer found containing gw-IP '%s', ignoring", route.Gw)
 				continue
@@ -223,7 +223,7 @@ func handleRouteEvents(routeSubChan <-chan netlink.RouteUpdate, filterOptions Fi
 
 		case unix.RTM_DELROUTE:
 			// Get peer containing dst-NetIP
-			peerIndex, ipNetIndex, err := wgChecks.PeerIndexByIPNet(wgDevice.Peers, *route.Dst)
+			peerIndex, ipNetIndex, err := wgChecks.PeerIndexByIPNet(&wgDevice.Peers, route.Dst)
 			if(err != nil){
 				logger.Warn.Printf("No peer found having dst-IPNet '%s', ignoring", route.Dst)
 				continue

lib/wgchecks/netchecks/netchecks.go

@@ -6,18 +6,18 @@ import (
 	"reflect"
 )
 
-func IPNetIndexByIP(list []net.IPNet, ip net.IP) (int, error) {
+func IPNetIndexByIP(list *[]net.IPNet, ip *net.IP) (int, error) {
-	for index, ipNetEntry := range list {
+	for index, ipNetEntry := range *list {
-		if ipNetEntry.Contains(ip) {
+		if ipNetEntry.Contains(*ip) {
 			return index, nil
 		}
 	}
 	return -1, fmt.Errorf("ip not in ipNet-list")
 }
 
-func IPNetIndexByIPNet(list []net.IPNet, ipNet net.IPNet) (int, error) {
+func IPNetIndexByIPNet(list *[]net.IPNet, ipNet *net.IPNet) (int, error) {
-	for index, ipNetEntry := range list {
+	for index, ipNetEntry := range *list {
-		if reflect.DeepEqual(ipNetEntry, ipNet) {
+		if reflect.DeepEqual(ipNetEntry, *ipNet) {
 			return index, nil
 		}
 	}

lib/wgchecks/wgchecks.go

@@ -9,34 +9,34 @@ import (
 	"golang.zx2c4.com/wireguard/wgctrl/wgtypes"
 )
 
-func PeerIndexByIP(peers []wgtypes.Peer, ip net.IP) (int, int, error) {
+func PeerIndexByIP(peers *[]wgtypes.Peer, ip *net.IP) (int, int, error) {
-	for index, peer := range peers {
+	for index, peer := range *peers {
-		if ipIndex, err := netchecks.IPNetIndexByIP(peer.AllowedIPs, ip); err == nil {
+		if ipIndex, err := netchecks.IPNetIndexByIP(&peer.AllowedIPs, ip); err == nil {
 			return index, ipIndex, nil
 		}
 	}
 	return -1, -1, fmt.Errorf("no peer by ip in list")
 }
-func PeerByIP(peers []wgtypes.Peer, ip net.IP) (*wgtypes.Peer, error) {
+func PeerByIP(peers *[]wgtypes.Peer, ip *net.IP) (*wgtypes.Peer, error) {
 	index, _, err := PeerIndexByIP(peers, ip)
 	if(err != nil) {
 		return nil, err
 	}
-	return &peers[index], nil
+	return &(*peers)[index], nil
 }
 
-func PeerIndexByIPNet(peers []wgtypes.Peer, ipNet net.IPNet) (int, int, error) {
+func PeerIndexByIPNet(peers *[]wgtypes.Peer, ipNet *net.IPNet) (int, int, error) {
-	for index, peer := range peers {
+	for index, peer := range *peers {
-		if ipNetIndex, err := netchecks.IPNetIndexByIPNet(peer.AllowedIPs, ipNet); err == nil {
+		if ipNetIndex, err := netchecks.IPNetIndexByIPNet(&peer.AllowedIPs, ipNet); err == nil {
 			return index, ipNetIndex, nil
 		}
 	}
 	return -1, -1, fmt.Errorf("no peer by ipNet in list")
 }
-func PeerByIPNet(peers []wgtypes.Peer, ipNet net.IPNet) (*wgtypes.Peer, error) {
+func PeerByIPNet(peers *[]wgtypes.Peer, ipNet *net.IPNet) (*wgtypes.Peer, error) {
 	index, _, err := PeerIndexByIPNet(peers, ipNet)
 	if(err != nil) {
 		return nil, err
 	}
-	return &peers[index], nil
+	return &(*peers)[index], nil
 }