1 files changed, 26 insertions, 0 deletions
diff --git a/ip.go b/ip.go
new file mode 100644
index 0000000..4be0dd3
--- /dev/null
+++ b/ip.go
@@ -0,0 +1,26 @@
+// SPDX-License-Identifier: BSD-2-Clause
+// SPDX-FileCopyrightText: Copyright (c) 2025 Runxi Yu <https://runxiyu.org>
+
+package main
+
+import (
+	"net/http"
+	"strings"
+)
+
+// getRemoteIP returns the remote IP address of the client. It respects
+// X-Forwarded-For if powxy is configured as a secondary proxy. Ports
+// are stripped.
+func getRemoteIP(request *http.Request) (remoteIP string) {
+	if secondary {
+		remoteIP, _, _ = strings.Cut(request.Header.Get("X-Forwarded-For"), ",")
+	}
+	if remoteIP == "" {
+		remoteIP = request.RemoteAddr
+		index := strings.LastIndex(remoteIP, ":")
+		if index != -1 {
+			remoteIP = remoteIP[:index]
+		}
+	}
+	return
+}