Update

vendor/github.com/gaissmai/bart/internal/tests/random/random.go

@@ -0,0 +1,129 @@
+// Copyright (c) 2026 Karl Gaissmaier
+// SPDX-License-Identifier: MIT
+
+package random
+
+import (
+	"fmt"
+	"math/rand/v2"
+	"net/netip"
+)
+
+// mpp is a abbreviation and panics on non masked prefixes.
+//
+//nolint:gochecknoglobals
+var mpp = func(s string) netip.Prefix {
+	pfx := netip.MustParsePrefix(s)
+	if pfx == pfx.Masked() {
+		return pfx
+	}
+	panic(fmt.Sprintf("%s is not canonicalized as %s", s, pfx.Masked()))
+}
+
+// Prefix returns a randomly generated prefix
+func Prefix(prng *rand.Rand) netip.Prefix {
+	if prng.IntN(2) == 1 {
+		return Prefix4(prng)
+	}
+	return Prefix6(prng)
+}
+
+func Prefix4(prng *rand.Rand) netip.Prefix {
+	bits := prng.IntN(33)
+	return netip.PrefixFrom(IP4(prng), bits).Masked()
+}
+
+func Prefix6(prng *rand.Rand) netip.Prefix {
+	bits := prng.IntN(129)
+	return netip.PrefixFrom(IP6(prng), bits).Masked()
+}
+
+func IP4(prng *rand.Rand) netip.Addr {
+	var b [4]byte
+	for i := range b {
+		//nolint:gosec // G115: integer overflow conversion uint -> byte
+		b[i] = byte(prng.UintN(256))
+	}
+	return netip.AddrFrom4(b)
+}
+
+func IP6(prng *rand.Rand) netip.Addr {
+	var b [16]byte
+	for i := range b {
+		//nolint:gosec // G115: integer overflow conversion uint -> byte
+		b[i] = byte(prng.UintN(256))
+	}
+	return netip.AddrFrom16(b)
+}
+
+func IP(prng *rand.Rand) netip.Addr {
+	if prng.IntN(2) == 1 {
+		return IP4(prng)
+	}
+	return IP6(prng)
+}
+
+func RealWorldPrefixes4(prng *rand.Rand, n int) []netip.Prefix {
+	set := make(map[netip.Prefix]struct{})
+	pfxs := make([]netip.Prefix, 0, n)
+
+	for len(set) < n {
+		pfx := Prefix4(prng)
+
+		// skip too small or too big masks
+		if pfx.Bits() < 8 || pfx.Bits() > 28 {
+			continue
+		}
+
+		// skip reserved/experimental ranges (e.g., 240.0.0.0/8)
+		if pfx.Overlaps(mpp("240.0.0.0/8")) {
+			continue
+		}
+
+		if _, ok := set[pfx]; !ok {
+			set[pfx] = struct{}{}
+			pfxs = append(pfxs, pfx)
+		}
+	}
+	return pfxs
+}
+
+func RealWorldPrefixes6(prng *rand.Rand, n int) []netip.Prefix {
+	set := make(map[netip.Prefix]struct{})
+	pfxs := make([]netip.Prefix, 0, n)
+
+	for len(set) < n {
+		pfx := Prefix6(prng)
+
+		// skip too small or too big masks
+		if pfx.Bits() < 16 || pfx.Bits() > 56 {
+			continue
+		}
+
+		// skip non global routes seen in the real world
+		if !pfx.Overlaps(mpp("2000::/3")) {
+			continue
+		}
+		if pfx.Addr().Compare(mpp("2c0f::/16").Addr()) == 1 {
+			continue
+		}
+
+		if _, ok := set[pfx]; !ok {
+			set[pfx] = struct{}{}
+			pfxs = append(pfxs, pfx)
+		}
+	}
+	return pfxs
+}
+
+func RealWorldPrefixes(prng *rand.Rand, n int) []netip.Prefix {
+	pfxs := make([]netip.Prefix, 0, n)
+	pfxs = append(pfxs, RealWorldPrefixes4(prng, n/2)...)
+	pfxs = append(pfxs, RealWorldPrefixes6(prng, n-len(pfxs))...)
+
+	prng.Shuffle(len(pfxs), func(i, j int) {
+		pfxs[i], pfxs[j] = pfxs[j], pfxs[i]
+	})
+
+	return pfxs
+}