implement IPv4 range bans

src/IPV4RangeSet.hh

@@ -0,0 +1,18 @@
+#pragma once
+
+#include <phosg/JSON.hh>
+#include <set>
+
+class IPV4RangeSet {
+public:
+  IPV4RangeSet() = default;
+  explicit IPV4RangeSet(const JSON& json);
+
+  JSON json() const;
+
+  bool check(uint32_t addr) const;
+  bool check(const struct sockaddr_storage& ss) const;
+
+protected:
+  std::map<uint32_t, uint8_t> ranges; // {addr: mask_bits}
+};