On Mon, 2 Nov 2020 15:56:43 +0800 LIU Yulong wrote:
> According to the RFC 2464 [1] the prefix "33:33:xx:xx:xx:xx" is defined to
> construct the multicast destination MAC address for IPv6 multicast traffic.
> The NDP (Neighbor Discovery Protocol for IPv6)[2] will comply with such
> rule. The work steps [6] are:
> *) Let's assume a destination address of 2001:db8:1:1::1.
> *) This is mapped into the "Solicited Node Multicast Address" (SNMA)
> format of ff02::1:ffXX:XXXX.
> *) The XX:XXXX represent the last 24 bits of the SNMA, and are derived
> directly from the last 24 bits of the destination address.
> *) Resulting in a SNMA ff02::1:ff00:0001, or ff02::1:ff00:1.
> *) This, being a multicast address, can be mapped to a multicast MAC
> address, using the format 33-33-XX-XX-XX-XX
> *) Resulting in 33-33-ff-00-00-01.
> *) This is a MAC address that is only being listened for by nodes
> sharing the same last 24 bits.
> *) In other words, while there is a chance for a "address collision",
> it is a vast improvement over ARP's guaranteed "collision".
> Kernel related code can be found at [3][4][5].
Please make sure you keep maintainers CCed on your postings, adding bond
maintainers now.
> +static inline bool is_ipv6_multicast_ether_addr(const u8 *addr)
> +{
> + return (addr[0] == 0x33) && (addr[1] == 0x33);
> +}
nit: brackets are not necessary here.
