read original addr from x-forwarded-for header if present

common/protocol/http/headers.go

@@ -0,0 +1,21 @@
+package http
+
+import (
+	"net/http"
+	"strings"
+
+	"v2ray.com/core/common/net"
+)
+
+func ParseXForwardedFor(header http.Header) []net.Address {
+	xff := header.Get("X-Forwarded-For")
+	if len(xff) == 0 {
+		return nil
+	}
+	list := strings.Split(xff, ",")
+	addrs := make([]net.Address, 0, len(list))
+	for _, proxy := range list {
+		addrs = append(addrs, net.ParseAddress(proxy))
+	}
+	return addrs
+}