net/DscpParser: new library

src/net/DscpParser.cxx

@@ -0,0 +1,116 @@
+/*
+ * Copyright 2022 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
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the
+ * distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
+ * FOUNDATION OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "DscpParser.hxx"
+#include "util/StringAPI.hxx"
+
+#include <cstdlib>
+
+#ifdef _WIN32
+#include <ws2tcpip.h>
+#else
+#include <netinet/ip.h>
+#endif
+
+#ifndef IPTOS_DSCP_AF11
+#define IPTOS_DSCP_AF11 0x28
+#define IPTOS_DSCP_AF12 0x30
+#define IPTOS_DSCP_AF13 0x38
+#define IPTOS_DSCP_AF21 0x48
+#define IPTOS_DSCP_AF22 0x50
+#define IPTOS_DSCP_AF23 0x58
+#define IPTOS_DSCP_AF31 0x68
+#define IPTOS_DSCP_AF32 0x70
+#define IPTOS_DSCP_AF33 0x78
+#define IPTOS_DSCP_AF41 0x88
+#define IPTOS_DSCP_AF42 0x90
+#define IPTOS_DSCP_AF43 0x98
+#endif
+
+#ifndef IPTOS_DSCP_CS0
+#define IPTOS_DSCP_CS0 0x00
+#define IPTOS_DSCP_CS1 0x20
+#define IPTOS_DSCP_CS2 0x40
+#define IPTOS_DSCP_CS3 0x60
+#define IPTOS_DSCP_CS4 0x80
+#define IPTOS_DSCP_CS5 0xa0
+#define IPTOS_DSCP_CS6 0xc0
+#define IPTOS_DSCP_CS7 0xe0
+#endif
+
+#ifndef IPTOS_DSCP_EF
+#define IPTOS_DSCP_EF 0xb8
+#endif
+
+#ifndef IPTOS_DSCP_LE
+#define IPTOS_DSCP_LE 0x01
+#endif
+
+static constexpr struct {
+	const char *name;
+	int value;
+} dscp_classes[] = {
+	{ "AF11", IPTOS_DSCP_AF11 },
+	{ "AF12", IPTOS_DSCP_AF12 },
+	{ "AF13", IPTOS_DSCP_AF13 },
+	{ "AF21", IPTOS_DSCP_AF21 },
+	{ "AF22", IPTOS_DSCP_AF22 },
+	{ "AF23", IPTOS_DSCP_AF23 },
+	{ "AF31", IPTOS_DSCP_AF31 },
+	{ "AF32", IPTOS_DSCP_AF32 },
+	{ "AF33", IPTOS_DSCP_AF33 },
+	{ "AF41", IPTOS_DSCP_AF41 },
+	{ "AF42", IPTOS_DSCP_AF42 },
+	{ "AF43", IPTOS_DSCP_AF43 },
+	{ "CS0", IPTOS_DSCP_CS0 },
+	{ "CS1", IPTOS_DSCP_CS1 },
+	{ "CS2", IPTOS_DSCP_CS2 },
+	{ "CS3", IPTOS_DSCP_CS3 },
+	{ "CS4", IPTOS_DSCP_CS4 },
+	{ "CS5", IPTOS_DSCP_CS5 },
+	{ "CS6", IPTOS_DSCP_CS6 },
+	{ "CS7", IPTOS_DSCP_CS7 },
+	{ "EF", IPTOS_DSCP_EF },
+	{ "LE", IPTOS_DSCP_LE },
+};
+
+int
+ParseDscpClass(const char *s) noexcept
+{
+	for (const auto &i : dscp_classes)
+		if (StringIsEqualIgnoreCase(s, i.name))
+			return i.value;
+
+	char *endptr;
+	unsigned long value = strtoul(s, &endptr, 0);
+	if (endptr > s && *endptr == 0 && value <= 0xff)
+		return value;
+
+	return -1;
+}

src/net/DscpParser.hxx

@@ -0,0 +1,41 @@
+/*
+ * Copyright 2022 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
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the
+ * distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
+ * FOUNDATION OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+
+/**
+ * Parse a DSCP (Differentiated Services Code Point) class name.
+ * This can either be a name (CS*, LE, AF*, EF) or numeric (decimal or
+ * hexadecimal).
+ *
+ * @return the DSCP or -1 on error
+ */
+[[gnu::pure]]
+int
+ParseDscpClass(const char *s) noexcept;

src/net/meson.build

@@ -1,6 +1,12 @@
+net_sources = []
+
 have_tcp = get_option('tcp')
 conf.set('HAVE_TCP', have_tcp)
 
+if have_tcp
+  net_sources += 'DscpParser.cxx'
+endif
+
 if have_tcp and not get_option('ipv6').disabled()
   if is_windows
     have_ipv6 = c_compiler.has_header_symbol('winsock2.h', 'AF_INET6')
@@ -29,6 +35,7 @@ endif
 
 net = static_library(
   'net',
+  net_sources,
   'ToString.cxx',
   'HostParser.cxx',
   'Resolver.cxx',