net/AllocatedSocketAddress: add method SetPort()

src/net/AllocatedSocketAddress.cxx

 /*
- * Copyright (C) 2012-2015 Max Kellermann <max.kellermann@gmail.com>
+ * Copyright (C) 2012-2017 Max Kellermann <max.kellermann@gmail.com>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -36,6 +36,14 @@
 #include <sys/un.h>
 #endif
 
+#ifdef HAVE_TCP
+#ifdef WIN32
+#include <ws2tcpip.h>
+#else
+#include <netinet/in.h>
+#endif
+#endif
+
 AllocatedSocketAddress &
 AllocatedSocketAddress::operator=(SocketAddress src)
 {
@@ -82,3 +90,32 @@ AllocatedSocketAddress::SetLocal(const char *path) noexcept
 }
 
 #endif
+
+#ifdef HAVE_TCP
+
+bool
+AllocatedSocketAddress::SetPort(unsigned port) noexcept
+{
+	if (IsNull())
+		return false;
+
+	switch (GetFamily()) {
+	case AF_INET:
+		{
+			auto *a = (struct sockaddr_in *)(void *)address;
+			a->sin_port = htons(port);
+			return true;
+		}
+
+	case AF_INET6:
+		{
+			auto *a = (struct sockaddr_in6 *)(void *)address;
+			a->sin6_port = htons(port);
+			return true;
+		}
+	}
+
+	return false;
+}
+
+#endif

src/net/AllocatedSocketAddress.hxx

 /*
- * Copyright (C) 2012-2015 Max Kellermann <max.kellermann@gmail.com>
+ * Copyright (C) 2012-2017 Max Kellermann <max.kellermann@gmail.com>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -143,6 +143,33 @@ public:
 	void SetLocal(const char *path) noexcept;
 #endif
 
+#ifdef HAVE_TCP
+	/**
+	 * Extract the port number.  Returns 0 if not applicable.
+	 */
+	gcc_pure
+	unsigned GetPort() const noexcept {
+		return ((SocketAddress)*this).GetPort();
+	}
+
+	/**
+	 * @return true on success, false if this address cannot have
+	 * a port number
+	 */
+	bool SetPort(unsigned port) noexcept;
+
+	static AllocatedSocketAddress WithPort(SocketAddress src,
+					       unsigned port) noexcept {
+		AllocatedSocketAddress result(src);
+		result.SetPort(port);
+		return result;
+	}
+
+	AllocatedSocketAddress WithPort(unsigned port) const noexcept {
+		return WithPort(*this, port);
+	}
+#endif
+
 private:
 	void SetSize(size_type new_size) noexcept;
 };