Commit 72f6d71e authored by Hangbin Liu's avatar Hangbin Liu Committed by David S. Miller
Browse files

vxlan: add ttl inherit support 



Like tos inherit, ttl inherit should also means inherit the inner protocol's
ttl values, which actually not implemented in vxlan yet.

But we could not treat ttl == 0 as "use the inner TTL", because that would be
used also when the "ttl" option is not specified and that would be a behavior
change, and breaking real use cases.

So add a different attribute IFLA_VXLAN_TTL_INHERIT when "ttl inherit" is
specified with ip cmd.

Reported-by: default avatarJianlin Shi <jishi@redhat.com>
Suggested-by: default avatarJiri Benc <jbenc@redhat.com>
Signed-off-by: default avatarHangbin Liu <liuhangbin@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 062b3e1b

drivers/net/vxlan.c

+14 −3
Original line number Diff line number Diff line
@@ -2085,9 +2085,13 @@ static void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev, 
		local_ip = vxlan->cfg.saddr;

		dst_cache = &rdst->dst_cache;

		md->gbp = skb->mark;

		if (flags & VXLAN_F_TTL_INHERIT) {

			ttl = ip_tunnel_get_ttl(old_iph, skb);

		} else {

			ttl = vxlan->cfg.ttl;

			if (!ttl && vxlan_addr_multicast(dst))

				ttl = 1;

		}



		tos = vxlan->cfg.tos;

		if (tos == 1)
@@ -2709,6 +2713,7 @@ static const struct nla_policy vxlan_policy[IFLA_VXLAN_MAX + 1] = { 
	[IFLA_VXLAN_GBP]	= { .type = NLA_FLAG, },

	[IFLA_VXLAN_GPE]	= { .type = NLA_FLAG, },

	[IFLA_VXLAN_REMCSUM_NOPARTIAL]	= { .type = NLA_FLAG },

	[IFLA_VXLAN_TTL_INHERIT]	= { .type = NLA_FLAG },

};



static int vxlan_validate(struct nlattr *tb[], struct nlattr *data[],
@@ -3254,6 +3259,12 @@ static int vxlan_nl2conf(struct nlattr *tb[], struct nlattr *data[], 
	if (data[IFLA_VXLAN_TTL])

		conf->ttl = nla_get_u8(data[IFLA_VXLAN_TTL]);



	if (data[IFLA_VXLAN_TTL_INHERIT]) {

		if (changelink)

			return -EOPNOTSUPP;

		conf->flags |= VXLAN_F_TTL_INHERIT;

	}



	if (data[IFLA_VXLAN_LABEL])

		conf->label = nla_get_be32(data[IFLA_VXLAN_LABEL]) &

			     IPV6_FLOWLABEL_MASK;

include/net/ip_tunnels.h

+11 −0
Original line number Diff line number Diff line
@@ -379,6 +379,17 @@ static inline u8 ip_tunnel_get_dsfield(const struct iphdr *iph, 
		return 0;

}



static inline u8 ip_tunnel_get_ttl(const struct iphdr *iph,

				       const struct sk_buff *skb)

{

	if (skb->protocol == htons(ETH_P_IP))

		return iph->ttl;

	else if (skb->protocol == htons(ETH_P_IPV6))

		return ((const struct ipv6hdr *)iph)->hop_limit;

	else

		return 0;

}



/* Propogate ECN bits out */

static inline u8 ip_tunnel_ecn_encap(u8 tos, const struct iphdr *iph,

				     const struct sk_buff *skb)

include/net/vxlan.h

+1 −0
Original line number Diff line number Diff line
@@ -262,6 +262,7 @@ struct vxlan_dev { 
#define VXLAN_F_COLLECT_METADATA	0x2000

#define VXLAN_F_GPE			0x4000

#define VXLAN_F_IPV6_LINKLOCAL		0x8000

#define VXLAN_F_TTL_INHERIT		0x10000



/* Flags that are used in the receive path. These flags must match in

 * order for a socket to be shareable

include/uapi/linux/if_link.h

+1 −0
Original line number Diff line number Diff line
@@ -516,6 +516,7 @@ enum { 
	IFLA_VXLAN_COLLECT_METADATA,

	IFLA_VXLAN_LABEL,

	IFLA_VXLAN_GPE,

	IFLA_VXLAN_TTL_INHERIT,

	__IFLA_VXLAN_MAX

};

#define IFLA_VXLAN_MAX	(__IFLA_VXLAN_MAX - 1)

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