Implement route rules

adapter/route/rule_cidr.go

@@ -0,0 +1,68 @@
+package route
+
+import (
+	"net/netip"
+	"strings"
+
+	"github.com/sagernet/sing-box/adapter"
+	"github.com/sagernet/sing/common"
+	F "github.com/sagernet/sing/common/format"
+)
+
+var _ RuleItem = (*IPCIDRItem)(nil)
+
+type IPCIDRItem struct {
+	prefixes []netip.Prefix
+	isSource bool
+}
+
+func NewIPCIDRItem(isSource bool, prefixStrings []string) (*IPCIDRItem, error) {
+	prefixes := make([]netip.Prefix, 0, len(prefixStrings))
+	for _, prefixString := range prefixStrings {
+		prefix, err := netip.ParsePrefix(prefixString)
+		if err != nil {
+			return nil, err
+		}
+		prefixes = append(prefixes, prefix)
+	}
+	return &IPCIDRItem{
+		prefixes: prefixes,
+		isSource: isSource,
+	}, nil
+}
+
+func (r *IPCIDRItem) Match(metadata *adapter.InboundContext) bool {
+	if r.isSource {
+		for _, prefix := range r.prefixes {
+			if prefix.Contains(metadata.Source.Addr) {
+				return true
+			}
+		}
+	} else {
+		if metadata.Destination.IsFqdn() {
+			return false
+		}
+		for _, prefix := range r.prefixes {
+			if prefix.Contains(metadata.Destination.Addr) {
+				return true
+			}
+		}
+	}
+	return false
+}
+
+func (r *IPCIDRItem) String() string {
+	var description string
+	if r.isSource {
+		description = "source_ipcidr="
+	} else {
+		description = "ipcidr="
+	}
+	pLen := len(r.prefixes)
+	if pLen == 1 {
+		description += r.prefixes[0].String()
+	} else {
+		description += "[" + strings.Join(common.Map(r.prefixes, F.ToString0[netip.Prefix]), " ") + "]"
+	}
+	return description
+}