[IPV6]: Fix source address selection for ORCHID addresses (99cd07a5) · Commits · 戴 / test

Skip the prefix length matching in source address selection for orchid -> non-orchid addresses. Overlay Routable Cryptographic Hash IDentifiers (RFC 4843, 2001:10::/28) are currenty not globally reachable. Without this check a host with an ORCHID address can end up preferring those over regular addresses when talking to other regular hosts in the 2001::/16 range thus breaking non-orchid connections. Signed-off-by:

Juha-Matti Tapio <jmtapio@verkkotelakka.net> Signed-off-by:

David S. Miller <davem@davemloft.net>

include/net/ipv6.h

+10 −0

Original line number	Diff line number	Diff line
		@@ -383,6 +383,16 @@ static inline int ipv6_addr_v4mapped(const struct in6_addr *a)
		a->s6_addr32[2] == htonl(0x0000ffff));
		}

		/*
		* Check for a RFC 4843 ORCHID address
		* (Overlay Routable Cryptographic Hash Identifiers)
		*/
		static inline int ipv6_addr_orchid(const struct in6_addr *a)
		{
		return ((a->s6_addr32[0] & htonl(0xfffffff0))
		== htonl(0x20010010));
		}

		/*
		* find the first different bit between two addresses
		* length of address must be a multiple of 32bits

net/ipv6/addrconf.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -1125,6 +1125,11 @@ int ipv6_dev_get_saddr(struct net_device *daddr_dev,
		if (hiscore.rule < 7)
		hiscore.rule++;
		#endif

		/* Skip rule 8 for orchid -> non-orchid address pairs. */
		if (ipv6_addr_orchid(&ifa->addr) && !ipv6_addr_orchid(daddr))
		continue;

		/* Rule 8: Use longest matching prefix */
		if (hiscore.rule < 8) {
		hiscore.matchlen = ipv6_addr_diff(&ifa_result->addr, daddr);

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