From 72dfba1be426f449a7f1c913c3656ff8b400ba9e Mon Sep 17 00:00:00 2001 From: Dan Luedtke Date: Wed, 4 Dec 2024 11:50:22 -0800 Subject: [PATCH] inet: Add common IPv6 packet header macros Adds commonly used IPv6 packet header macros similar to what is available on NetBSD and FreeBSD in sys/netinet/ip6.h and Android in libc/include/netinet/ip6.h Usage example IPV6_VERSION_MASK and IPV6_VERSION: if ((ip6->ip6_vfc & IPV6_VERSION_MASK) == IPV6_VERSION) return true; Usage example IPV6_FLOWINFO_MASK: ip6->ip6_flow = (flow & IPV6_FLOWINFO_MASK); The relevant standard is RFC2460 (Internet Protocol, Version 6 Specification). It defines the Internet Protocol version (IPV6_VERSION) and reduced the size of the flow label field from 24 to 20 bits (IPV6_FLOWLABEL_MASK). The traffic class and flow label fields together make up the flow information (IPV6_FLOWINFO_MASK). Tested on x86_64 GNU/Linux Signed-off-by: Dan Luedtke Reviewed-by: Adhemerval Zanella --- inet/netinet/ip6.h | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/inet/netinet/ip6.h b/inet/netinet/ip6.h index 3caac7a46d..1edb2e4009 100644 --- a/inet/netinet/ip6.h +++ b/inet/netinet/ip6.h @@ -46,6 +46,17 @@ struct ip6_hdr #define ip6_hlim ip6_ctlun.ip6_un1.ip6_un1_hlim #define ip6_hops ip6_ctlun.ip6_un1.ip6_un1_hlim +#define IPV6_VERSION 0x60 +#define IPV6_VERSION_MASK 0xf0 + +#if __BYTE_ORDER == __BIG_ENDIAN +#define IPV6_FLOWINFO_MASK 0x0fffffff /* flow info (28 bits) */ +#define IPV6_FLOWLABEL_MASK 0x000fffff /* flow label (20 bits) */ +#else /* __BYTE_ORDER == __LITTLE_ENDIAN */ +#define IPV6_FLOWINFO_MASK 0xffffff0f /* flow info (28 bits) */ +#define IPV6_FLOWLABEL_MASK 0xffff0f00 /* flow label (20 bits) */ +#endif + /* Generic extension header. */ struct ip6_ext { -- 2.47.2