Update dependencies

vendor/tailscale.com/net/netutil/routes.go

@@ -0,0 +1,89 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+package netutil
+
+import (
+	"encoding/binary"
+	"fmt"
+	"net/netip"
+	"sort"
+	"strings"
+
+	"tailscale.com/net/tsaddr"
+)
+
+func validateViaPrefix(ipp netip.Prefix) error {
+	if !tsaddr.IsViaPrefix(ipp) {
+		return fmt.Errorf("%v is not a 4-in-6 prefix", ipp)
+	}
+	if ipp.Bits() < (128 - 32) {
+		return fmt.Errorf("%v 4-in-6 prefix must be at least a /%v", ipp, 128-32)
+	}
+	a := ipp.Addr().As16()
+	// The first 64 bits of a are the via prefix.
+	// The next 32 bits are the "site ID".
+	// The last 32 bits are the IPv4.
+	//
+	// We used to only allow advertising site IDs from 0-255, but we have
+	// since relaxed this (as of 2024-01) to allow IDs from 0-65535.
+	siteID := binary.BigEndian.Uint32(a[8:12])
+	if siteID > 0xFFFF {
+		return fmt.Errorf("route %v contains invalid site ID %08x; must be 0xffff or less", ipp, siteID)
+	}
+	return nil
+}
+
+// CalcAdvertiseRoutes calculates the requested routes to be advertised by a node.
+// advertiseRoutes is the user-provided, comma-separated list of routes (IP addresses or CIDR prefixes) to advertise.
+// advertiseDefaultRoute indicates whether the node should act as an exit node and advertise default routes.
+func CalcAdvertiseRoutes(advertiseRoutes string, advertiseDefaultRoute bool) ([]netip.Prefix, error) {
+	routeMap := map[netip.Prefix]bool{}
+	if advertiseRoutes != "" {
+		var default4, default6 bool
+		advroutes := strings.Split(advertiseRoutes, ",")
+		for _, s := range advroutes {
+			ipp, err := netip.ParsePrefix(s)
+			if err != nil {
+				return nil, fmt.Errorf("%q is not a valid IP address or CIDR prefix", s)
+			}
+			if ipp != ipp.Masked() {
+				return nil, fmt.Errorf("%s has non-address bits set; expected %s", ipp, ipp.Masked())
+			}
+			if tsaddr.IsViaPrefix(ipp) {
+				if err := validateViaPrefix(ipp); err != nil {
+					return nil, err
+				}
+			}
+			if ipp == tsaddr.AllIPv4() {
+				default4 = true
+			} else if ipp == tsaddr.AllIPv6() {
+				default6 = true
+			}
+			routeMap[ipp] = true
+		}
+		if default4 && !default6 {
+			return nil, fmt.Errorf("%s advertised without its IPv6 counterpart, please also advertise %s", tsaddr.AllIPv4(), tsaddr.AllIPv6())
+		} else if default6 && !default4 {
+			return nil, fmt.Errorf("%s advertised without its IPv4 counterpart, please also advertise %s", tsaddr.AllIPv6(), tsaddr.AllIPv4())
+		}
+	}
+	if advertiseDefaultRoute {
+		routeMap[tsaddr.AllIPv4()] = true
+		routeMap[tsaddr.AllIPv6()] = true
+	}
+	if len(routeMap) == 0 {
+		return nil, nil
+	}
+	routes := make([]netip.Prefix, 0, len(routeMap))
+	for r := range routeMap {
+		routes = append(routes, r)
+	}
+	sort.Slice(routes, func(i, j int) bool {
+		if routes[i].Bits() != routes[j].Bits() {
+			return routes[i].Bits() < routes[j].Bits()
+		}
+		return routes[i].Addr().Less(routes[j].Addr())
+	})
+	return routes, nil
+}