feature/rate-limit (#91)

vendor/github.com/ulule/limiter/v3/network.go

@@ -0,0 +1,72 @@
+package limiter
+
+import (
+	"net"
+	"net/http"
+	"strings"
+)
+
+var (
+	// DefaultIPv4Mask defines the default IPv4 mask used to obtain user IP.
+	DefaultIPv4Mask = net.CIDRMask(32, 32)
+	// DefaultIPv6Mask defines the default IPv6 mask used to obtain user IP.
+	DefaultIPv6Mask = net.CIDRMask(128, 128)
+)
+
+// GetIP returns IP address from request.
+func (limiter *Limiter) GetIP(r *http.Request) net.IP {
+	return GetIP(r, limiter.Options)
+}
+
+// GetIPWithMask returns IP address from request by applying a mask.
+func (limiter *Limiter) GetIPWithMask(r *http.Request) net.IP {
+	return GetIPWithMask(r, limiter.Options)
+}
+
+// GetIPKey extracts IP from request and returns hashed IP to use as store key.
+func (limiter *Limiter) GetIPKey(r *http.Request) string {
+	return limiter.GetIPWithMask(r).String()
+}
+
+// GetIP returns IP address from request.
+// If options is defined and TrustForwardHeader is true, it will lookup IP in
+// X-Forwarded-For and X-Real-IP headers.
+func GetIP(r *http.Request, options ...Options) net.IP {
+	if len(options) >= 1 && options[0].TrustForwardHeader {
+		ip := r.Header.Get("X-Forwarded-For")
+		if ip != "" {
+			parts := strings.SplitN(ip, ",", 2)
+			part := strings.TrimSpace(parts[0])
+			return net.ParseIP(part)
+		}
+
+		ip = strings.TrimSpace(r.Header.Get("X-Real-IP"))
+		if ip != "" {
+			return net.ParseIP(ip)
+		}
+	}
+
+	remoteAddr := strings.TrimSpace(r.RemoteAddr)
+	host, _, err := net.SplitHostPort(remoteAddr)
+	if err != nil {
+		return net.ParseIP(remoteAddr)
+	}
+
+	return net.ParseIP(host)
+}
+
+// GetIPWithMask returns IP address from request by applying a mask.
+func GetIPWithMask(r *http.Request, options ...Options) net.IP {
+	if len(options) == 0 {
+		return GetIP(r)
+	}
+
+	ip := GetIP(r, options[0])
+	if ip.To4() != nil {
+		return ip.Mask(options[0].IPv4Mask)
+	}
+	if ip.To16() != nil {
+		return ip.Mask(options[0].IPv6Mask)
+	}
+	return ip
+}