[client] Add detailed routes and resolved IPs to debug bundle (#4141)

client/internal/routemanager/systemops/systemops_bsd.go

@@ -16,12 +16,6 @@ import (
 	"golang.org/x/net/route"
 )
 
-type Route struct {
-	Dst       netip.Prefix
-	Gw        netip.Addr
-	Interface *net.Interface
-}
-
 func GetRoutesFromTable() ([]netip.Prefix, error) {
 	tab, err := retryFetchRIB()
 	if err != nil {
@@ -47,25 +41,134 @@ func GetRoutesFromTable() ([]netip.Prefix, error) {
 			continue
 		}
 
-		route, err := MsgToRoute(m)
+		r, err := MsgToRoute(m)
 		if err != nil {
 			log.Warnf("Failed to parse route message: %v", err)
 			continue
 		}
-		if route.Dst.IsValid() {
-			prefixList = append(prefixList, route.Dst)
+		if r.Dst.IsValid() {
+			prefixList = append(prefixList, r.Dst)
 		}
 	}
 	return prefixList, nil
 }
 
+func GetDetailedRoutesFromTable() ([]DetailedRoute, error) {
+	tab, err := retryFetchRIB()
+	if err != nil {
+		return nil, fmt.Errorf("fetch RIB: %v", err)
+	}
+
+	msgs, err := route.ParseRIB(route.RIBTypeRoute, tab)
+	if err != nil {
+		return nil, fmt.Errorf("parse RIB: %v", err)
+	}
+
+	return processRouteMessages(msgs)
+}
+
+func processRouteMessages(msgs []route.Message) ([]DetailedRoute, error) {
+	var detailedRoutes []DetailedRoute
+
+	for _, msg := range msgs {
+		m := msg.(*route.RouteMessage)
+
+		if !isValidRouteMessage(m) {
+			continue
+		}
+
+		if filterRoutesByFlags(m.Flags) {
+			continue
+		}
+
+		detailed, err := buildDetailedRouteFromMessage(m)
+		if err != nil {
+			log.Warnf("Failed to parse route message: %v", err)
+			continue
+		}
+
+		if detailed != nil {
+			detailedRoutes = append(detailedRoutes, *detailed)
+		}
+	}
+
+	return detailedRoutes, nil
+}
+
+func isValidRouteMessage(m *route.RouteMessage) bool {
+	if m.Version < 3 || m.Version > 5 {
+		log.Warnf("Unexpected RIB message version: %d", m.Version)
+		return false
+	}
+	if m.Type != syscall.RTM_GET {
+		log.Warnf("Unexpected RIB message type: %d", m.Type)
+		return false
+	}
+	return true
+}
+
+func buildDetailedRouteFromMessage(m *route.RouteMessage) (*DetailedRoute, error) {
+	routeMsg, err := MsgToRoute(m)
+	if err != nil {
+		return nil, err
+	}
+
+	if !routeMsg.Dst.IsValid() {
+		return nil, errors.New("invalid destination")
+	}
+
+	detailed := DetailedRoute{
+		Route: Route{
+			Dst:       routeMsg.Dst,
+			Gw:        routeMsg.Gw,
+			Interface: routeMsg.Interface,
+		},
+		Metric:   extractBSDMetric(m),
+		Protocol: extractBSDProtocol(m.Flags),
+		Scope:    "global",
+		Type:     "unicast",
+		Table:    "main",
+		Flags:    formatBSDFlags(m.Flags),
+	}
+
+	return &detailed, nil
+}
+
+func buildLinkInterface(t *route.LinkAddr) *net.Interface {
+	interfaceName := fmt.Sprintf("link#%d", t.Index)
+	if t.Name != "" {
+		interfaceName = t.Name
+	}
+	return &net.Interface{
+		Index: t.Index,
+		Name:  interfaceName,
+	}
+}
+
+func extractBSDMetric(m *route.RouteMessage) int {
+	return -1
+}
+
+func extractBSDProtocol(flags int) string {
+	if flags&syscall.RTF_STATIC != 0 {
+		return "static"
+	}
+	if flags&syscall.RTF_DYNAMIC != 0 {
+		return "dynamic"
+	}
+	if flags&syscall.RTF_LOCAL != 0 {
+		return "local"
+	}
+	return "kernel"
+}
+
 func retryFetchRIB() ([]byte, error) {
 	var out []byte
 	operation := func() error {
 		var err error
 		out, err = route.FetchRIB(syscall.AF_UNSPEC, route.RIBTypeRoute, 0)
 		if errors.Is(err, syscall.ENOMEM) {
-			log.Debug("~etrying fetchRIB due to 'cannot allocate memory' error")
+			log.Debug("Retrying fetchRIB due to 'cannot allocate memory' error")
 			return err
 		} else if err != nil {
 			return backoff.Permanent(err)
@@ -100,7 +203,6 @@ func toNetIP(a route.Addr) netip.Addr {
 	}
 }
 
-// ones returns the number of leading ones in the mask.
 func ones(a route.Addr) (int, error) {
 	switch t := a.(type) {
 	case *route.Inet4Addr:
@@ -114,7 +216,6 @@ func ones(a route.Addr) (int, error) {
 	}
 }
 
-// MsgToRoute converts a route message to a Route.
 func MsgToRoute(msg *route.RouteMessage) (*Route, error) {
 	dstIP, nexthop, dstMask := msg.Addrs[0], msg.Addrs[1], msg.Addrs[2]
 
@@ -127,10 +228,7 @@ func MsgToRoute(msg *route.RouteMessage) (*Route, error) {
 	case *route.Inet4Addr, *route.Inet6Addr:
 		nexthopAddr = toNetIP(t)
 	case *route.LinkAddr:
-		nexthopIntf = &net.Interface{
-			Index: t.Index,
-			Name:  t.Name,
-		}
+		nexthopIntf = buildLinkInterface(t)
 	default:
 		return nil, fmt.Errorf("unexpected next hop type: %T", t)
 	}
@@ -156,5 +254,4 @@ func MsgToRoute(msg *route.RouteMessage) (*Route, error) {
 		Gw:        nexthopAddr,
 		Interface: nexthopIntf,
 	}, nil
-
 }