ip6_tunnel: Allow rcv/xmit even if remote address is a local address

Currently, ip6_tnl_xmit_ctl drops tunneled packets if the remote address (outer v6 destination) is one of host's locally configured addresses. Same applies to ip6_tnl_rcv_ctl: it drops packets if the remote address (outer v6 source) is a local address. This prevents using ipxip6 (and ip6_gre) tunnels whose local/remote endpoints are on same host; OTOH v4 tunnels (ipip or gre) allow such configurations. An example where this proves useful is a system where entities are identified by their unique v6 addresses, and use tunnels to encapsulate traffic between them. The limitation prevents placing several entities on same host. Introduce IP6_TNL_F_ALLOW_LOCAL_REMOTE which allows to bypass this restriction.

Shmulik Ladkani committed 9 years ago

Commit 908d1401 parent 6a331e12 files · +6 −2Browse files

Showing the changes to include/uapi/linux (1 of 2 files). Show all

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include/uapi/linux/ip6_tunnel.h+2−0

@@ -20,6 +20,8 @@ · 19 unmodified lines
20	20	#define IP6_TNL_F_RCV_DSCP_COPY 0x10
21	21	/* copy fwmark from inner packet */
22	22	#define IP6_TNL_F_USE_ORIG_FWMARK 0x20
	23	+/* allow remote endpoint on the local node */
	24	+#define IP6_TNL_F_ALLOW_LOCAL_REMOTE 0x40
23	25
24	26	struct ip6_tnl_parm {
25	27	char name[IFNAMSIZ]; /* name of tunnel device */