net: Add ipv6 prefix mask function (54942ec9) · Commits · Wenxi XU / zephyr

include/zephyr/net/net_ip.h

+32 −0

Original line number	Diff line number	Diff line
		@@ -745,6 +745,38 @@ static inline bool net_ipv6_is_prefix(const uint8_t *addr1,
		return (addr1[bytes] & mask) == (addr2[bytes] & mask);
		}


		/**
		* @brief Get the IPv6 network address via the unicast address and the prefix mask.
		*
		* @param inaddr Unicast IPv6 address.
		* @param outaddr Prefix masked IPv6 address (network address).
		* @param prefix_len Prefix length (max length is 128).
		*/
		static inline void net_ipv6_addr_prefix_mask(const uint8_t *inaddr,
		uint8_t *outaddr,
		uint8_t prefix_len)
		{
		uint8_t bits = 128 - prefix_len;
		uint8_t bytes = prefix_len / 8U;
		uint8_t remain = bits % 8;
		uint8_t mask;

		memset(outaddr, 0, 16U);
		memcpy(outaddr, inaddr, bytes);

		if (!remain) {
		/* No remaining bits, the prefixes are the same as first
		* bytes are the same.
		*/
		return;
		}

		/* Create a mask that has remaining most significant bits set */
		mask = (uint8_t)((0xff << (8 - remain)) ^ 0xff) << remain;
		outaddr[bytes] = inaddr[bytes] & mask;
		}

		/**
		* @brief Check if the IPv4 address is a loopback address (127.0.0.0/8).
		*