xfrm: Move dst->path into struct xfrm_dst
The first member of an IPSEC route bundle chain sets it's dst->path to
the underlying ipv4/ipv6 route that carries the bundle.
Stated another way, if one were to follow the xfrm_dst->child chain of
the bundle, the final non-NULL pointer would be the path and point to
either an ipv4 or an ipv6 route.
This is largely used to make sure that PMTU events propagate down to
the correct ipv4 or ipv6 route.
When we don't have the top of an IPSEC bundle 'dst->path == dst'.
Move it down into xfrm_dst and key off of dst->xfrm.
Signed-off-by: David S. Miller <davem@davemloft.net>
Reviewed-by: Eric Dumazet <edumazet@google.com>
diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index 0009dab..1ec0c47 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -985,6 +985,7 @@
} u;
struct dst_entry *route;
struct dst_entry *child;
+ struct dst_entry *path;
struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
int num_pols, num_xfrms;
u32 xfrm_genid;
@@ -995,6 +996,18 @@
u32 path_cookie;
};
+static inline struct dst_entry *xfrm_dst_path(const struct dst_entry *dst)
+{
+#ifdef CONFIG_XFRM
+ if (dst->xfrm) {
+ const struct xfrm_dst *xdst = (const struct xfrm_dst *) dst;
+
+ return xdst->path;
+ }
+#endif
+ return (struct dst_entry *) dst;
+}
+
static inline struct dst_entry *xfrm_dst_child(const struct dst_entry *dst)
{
#ifdef CONFIG_XFRM
@@ -1889,7 +1902,7 @@
return false;
xdst = (struct xfrm_dst *) dst;
- if (x->xso.offload_handle && (x->xso.dev == dst->path->dev) &&
+ if (x->xso.offload_handle && (x->xso.dev == xfrm_dst_path(dst)->dev) &&
!xdst->child->xfrm)
return true;