init: fork

ruleset/builtins/geo/matchers_v2geo.go

@@ -0,0 +1,213 @@
+package geo
+
+import (
+	"bytes"
+	"errors"
+	"net"
+	"regexp"
+	"sort"
+	"strings"
+
+	"github.com/DifuseHQ/Mellaris/ruleset/builtins/geo/v2geo"
+)
+
+var _ hostMatcher = (*geoipMatcher)(nil)
+
+type geoipMatcher struct {
+	N4      []*net.IPNet // sorted
+	N6      []*net.IPNet // sorted
+	Inverse bool
+}
+
+// matchIP tries to match the given IP address with the corresponding IPNets.
+// Note that this function does NOT handle the Inverse flag.
+func (m *geoipMatcher) matchIP(ip net.IP) bool {
+	var n []*net.IPNet
+	if ip4 := ip.To4(); ip4 != nil {
+		// N4 stores IPv4 addresses in 4-byte form.
+		// Make sure we use it here too, otherwise bytes.Compare will fail.
+		ip = ip4
+		n = m.N4
+	} else {
+		n = m.N6
+	}
+	left, right := 0, len(n)-1
+	for left <= right {
+		mid := (left + right) / 2
+		if n[mid].Contains(ip) {
+			return true
+		} else if bytes.Compare(n[mid].IP, ip) < 0 {
+			left = mid + 1
+		} else {
+			right = mid - 1
+		}
+	}
+	return false
+}
+
+func (m *geoipMatcher) Match(host HostInfo) bool {
+	if host.IPv4 != nil {
+		if m.matchIP(host.IPv4) {
+			return !m.Inverse
+		}
+	}
+	if host.IPv6 != nil {
+		if m.matchIP(host.IPv6) {
+			return !m.Inverse
+		}
+	}
+	return m.Inverse
+}
+
+func newGeoIPMatcher(list *v2geo.GeoIP) (*geoipMatcher, error) {
+	n4 := make([]*net.IPNet, 0)
+	n6 := make([]*net.IPNet, 0)
+	for _, cidr := range list.Cidr {
+		if len(cidr.Ip) == 4 {
+			// IPv4
+			n4 = append(n4, &net.IPNet{
+				IP:   cidr.Ip,
+				Mask: net.CIDRMask(int(cidr.Prefix), 32),
+			})
+		} else if len(cidr.Ip) == 16 {
+			// IPv6
+			n6 = append(n6, &net.IPNet{
+				IP:   cidr.Ip,
+				Mask: net.CIDRMask(int(cidr.Prefix), 128),
+			})
+		} else {
+			return nil, errors.New("invalid IP length")
+		}
+	}
+	// Sort the IPNets, so we can do binary search later.
+	sort.Slice(n4, func(i, j int) bool {
+		return bytes.Compare(n4[i].IP, n4[j].IP) < 0
+	})
+	sort.Slice(n6, func(i, j int) bool {
+		return bytes.Compare(n6[i].IP, n6[j].IP) < 0
+	})
+	return &geoipMatcher{
+		N4:      n4,
+		N6:      n6,
+		Inverse: list.InverseMatch,
+	}, nil
+}
+
+var _ hostMatcher = (*geositeMatcher)(nil)
+
+type geositeDomainType int
+
+const (
+	geositeDomainPlain geositeDomainType = iota
+	geositeDomainRegex
+	geositeDomainRoot
+	geositeDomainFull
+)
+
+type geositeDomain struct {
+	Type  geositeDomainType
+	Value string
+	Regex *regexp.Regexp
+	Attrs map[string]bool
+}
+
+type geositeMatcher struct {
+	Domains []geositeDomain
+	// Attributes are matched using "and" logic - if you have multiple attributes here,
+	// a domain must have all of those attributes to be considered a match.
+	Attrs []string
+}
+
+func (m *geositeMatcher) matchDomain(domain geositeDomain, host HostInfo) bool {
+	// Match attributes first
+	if len(m.Attrs) > 0 {
+		if len(domain.Attrs) == 0 {
+			return false
+		}
+		for _, attr := range m.Attrs {
+			if !domain.Attrs[attr] {
+				return false
+			}
+		}
+	}
+
+	switch domain.Type {
+	case geositeDomainPlain:
+		return strings.Contains(host.Name, domain.Value)
+	case geositeDomainRegex:
+		if domain.Regex != nil {
+			return domain.Regex.MatchString(host.Name)
+		}
+	case geositeDomainFull:
+		return host.Name == domain.Value
+	case geositeDomainRoot:
+		if host.Name == domain.Value {
+			return true
+		}
+		return strings.HasSuffix(host.Name, "."+domain.Value)
+	default:
+		return false
+	}
+	return false
+}
+
+func (m *geositeMatcher) Match(host HostInfo) bool {
+	for _, domain := range m.Domains {
+		if m.matchDomain(domain, host) {
+			return true
+		}
+	}
+	return false
+}
+
+func newGeositeMatcher(list *v2geo.GeoSite, attrs []string) (*geositeMatcher, error) {
+	domains := make([]geositeDomain, len(list.Domain))
+	for i, domain := range list.Domain {
+		switch domain.Type {
+		case v2geo.Domain_Plain:
+			domains[i] = geositeDomain{
+				Type:  geositeDomainPlain,
+				Value: domain.Value,
+				Attrs: domainAttributeToMap(domain.Attribute),
+			}
+		case v2geo.Domain_Regex:
+			regex, err := regexp.Compile(domain.Value)
+			if err != nil {
+				return nil, err
+			}
+			domains[i] = geositeDomain{
+				Type:  geositeDomainRegex,
+				Regex: regex,
+				Attrs: domainAttributeToMap(domain.Attribute),
+			}
+		case v2geo.Domain_Full:
+			domains[i] = geositeDomain{
+				Type:  geositeDomainFull,
+				Value: domain.Value,
+				Attrs: domainAttributeToMap(domain.Attribute),
+			}
+		case v2geo.Domain_RootDomain:
+			domains[i] = geositeDomain{
+				Type:  geositeDomainRoot,
+				Value: domain.Value,
+				Attrs: domainAttributeToMap(domain.Attribute),
+			}
+		default:
+			return nil, errors.New("unsupported domain type")
+		}
+	}
+	return &geositeMatcher{
+		Domains: domains,
+		Attrs:   attrs,
+	}, nil
+}
+
+func domainAttributeToMap(attrs []*v2geo.Domain_Attribute) map[string]bool {
+	m := make(map[string]bool)
+	for _, attr := range attrs {
+		// Supposedly there are also int attributes,
+		// but nobody seems to use them, so we treat everything as boolean for now.
+		m[attr.Key] = true
+	}
+	return m
+}