MEDIUM: http: add IPv6 support for "set-tos"
As per RFC3260 #4 and BCP37 #4.2 and #5.2, the IPv6 counterpart of TOS
is "traffic class".
Add support for IPv6 traffic class in "set-tos" by moving the "set-tos"
related code to the new inline function inet_set_tos(), handling IPv4
(IP_TOS), IPv6 (IPV6_TCLASS) and IPv4-mapped sockets (IP_TOS, like
::ffff:127.0.0.1).
Also define - if missing - the IN6_IS_ADDR_V4MAPPED() macro in
include/common/compat.h for compatibility.
diff --git a/include/common/compat.h b/include/common/compat.h
index a0764b1..48ea1f7 100644
--- a/include/common/compat.h
+++ b/include/common/compat.h
@@ -129,6 +129,14 @@
#endif
#endif
+/* If IPv6 is supported, define IN6_IS_ADDR_V4MAPPED() if missing. */
+#if defined(IPV6_TCLASS) && !defined(IN6_IS_ADDR_V4MAPPED)
+#define IN6_IS_ADDR_V4MAPPED(a) \
+((((const uint32_t *) (a))[0] == 0) \
+&& (((const uint32_t *) (a))[1] == 0) \
+&& (((const uint32_t *) (a))[2] == htonl (0xffff)))
+#endif
+
#if defined(__dietlibc__)
#include <strings.h>
#endif