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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: Jianlin Shi <jishi@redhat.com>
Suggested-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Hangbin Liu 2018-04-17 14:11:28 +08:00 committed by David S. Miller
parent 062b3e1b6d
commit 72f6d71e49
4 changed files with 27 additions and 3 deletions

View file

@ -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;
ttl = vxlan->cfg.ttl;
if (!ttl && vxlan_addr_multicast(dst))
ttl = 1;
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;

View file

@ -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)

View file

@ -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

View file

@ -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)