ila: Perform only one translation in forwarding path

When setting up ILA in a router we noticed that the the encapsulation
is invoked twice: once in the route input path and again upon route
output. To resolve this we add a flag set_csum_neutral for the
ila_update_ipv6_locator. If this flag is set and the checksum
neutral bit is also set we assume that checksum-neutral translation
has already been performed and take no further action. The
flag is set only in ila_output path. The flag is not set for ila_input and
ila_xlat.

Tested:

Used 3 netns to set to emulate a router and two hosts. The router
translates SIR addresses between the two destinations in other two netns.
Verified ping and netperf are functional.

Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Tom Herbert 2016-06-07 16:09:44 -07:00 committed by David S. Miller
parent e00431bc93
commit 707a2ca487
4 changed files with 12 additions and 9 deletions

View File

@ -109,7 +109,8 @@ static inline bool ila_csum_neutral_set(struct ila_identifier ident)
return !!(ident.csum_neutral);
}
void ila_update_ipv6_locator(struct sk_buff *skb, struct ila_params *p);
void ila_update_ipv6_locator(struct sk_buff *skb, struct ila_params *p,
bool set_csum_neutral);
void ila_init_saved_csum(struct ila_params *p);

View File

@ -103,7 +103,8 @@ static void ila_csum_adjust_transport(struct sk_buff *skb,
iaddr->loc = p->locator;
}
void ila_update_ipv6_locator(struct sk_buff *skb, struct ila_params *p)
void ila_update_ipv6_locator(struct sk_buff *skb, struct ila_params *p,
bool set_csum_neutral)
{
struct ipv6hdr *ip6h = ipv6_hdr(skb);
struct ila_addr *iaddr = ila_a2i(&ip6h->daddr);
@ -114,7 +115,8 @@ void ila_update_ipv6_locator(struct sk_buff *skb, struct ila_params *p)
* is a locator being translated to a SIR address.
* Perform (receiver) checksum-neutral translation.
*/
ila_csum_do_neutral(iaddr, p);
if (!set_csum_neutral)
ila_csum_do_neutral(iaddr, p);
} else {
switch (p->csum_mode) {
case ILA_CSUM_ADJUST_TRANSPORT:

View File

@ -26,7 +26,7 @@ static int ila_output(struct net *net, struct sock *sk, struct sk_buff *skb)
if (skb->protocol != htons(ETH_P_IPV6))
goto drop;
ila_update_ipv6_locator(skb, ila_params_lwtunnel(dst->lwtstate));
ila_update_ipv6_locator(skb, ila_params_lwtunnel(dst->lwtstate), true);
return dst->lwtstate->orig_output(net, sk, skb);
@ -42,7 +42,7 @@ static int ila_input(struct sk_buff *skb)
if (skb->protocol != htons(ETH_P_IPV6))
goto drop;
ila_update_ipv6_locator(skb, ila_params_lwtunnel(dst->lwtstate));
ila_update_ipv6_locator(skb, ila_params_lwtunnel(dst->lwtstate), false);
return dst->lwtstate->orig_input(skb);

View File

@ -210,14 +210,14 @@ static void ila_free_cb(void *ptr, void *arg)
}
}
static int ila_xlat_addr(struct sk_buff *skb);
static int ila_xlat_addr(struct sk_buff *skb, bool set_csum_neutral);
static unsigned int
ila_nf_input(void *priv,
struct sk_buff *skb,
const struct nf_hook_state *state)
{
ila_xlat_addr(skb);
ila_xlat_addr(skb, false);
return NF_ACCEPT;
}
@ -597,7 +597,7 @@ static struct pernet_operations ila_net_ops = {
.size = sizeof(struct ila_net),
};
static int ila_xlat_addr(struct sk_buff *skb)
static int ila_xlat_addr(struct sk_buff *skb, bool set_csum_neutral)
{
struct ila_map *ila;
struct ipv6hdr *ip6h = ipv6_hdr(skb);
@ -616,7 +616,7 @@ static int ila_xlat_addr(struct sk_buff *skb)
ila = ila_lookup_wildcards(iaddr, skb->dev->ifindex, ilan);
if (ila)
ila_update_ipv6_locator(skb, &ila->xp.ip);
ila_update_ipv6_locator(skb, &ila->xp.ip, set_csum_neutral);
rcu_read_unlock();