[RFC PATCH 06/12] ipsec: Create and use new helpers for dst child access.

[David Miller]

This will make a future change moving the dst->child pointer less
invasive.

Signed-off-by: David S. Miller <da...@davemloft.net>
---
 include/net/xfrm.h     |  5 +++++
 net/xfrm/xfrm_policy.c | 57 +++++++++++++++++++++++++-------------------------
 2 files changed, 33 insertions(+), 29 deletions(-)

diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index 4fa951112873..5a4cc05ff9e8 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -1003,6 +1003,11 @@ static inline struct dst_entry *xfrm_dst_child(const 
struct dst_entry *dst)
        return NULL;
 }
 
+static inline void xfrm_dst_set_child(struct xfrm_dst *xdst, struct dst_entry 
*child)
+{
+       xdst->u.dst.child = child;
+}
+
 static inline void xfrm_dst_destroy(struct xfrm_dst *xdst)
 {
        xfrm_pols_put(xdst->pols, xdst->num_pols);
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index c68fb3327a68..206ac90ff4f0 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -1545,8 +1545,8 @@ static struct dst_entry *xfrm_bundle_create(struct 
xfrm_policy *policy,
        unsigned long now = jiffies;
        struct net_device *dev;
        struct xfrm_mode *inner_mode;
-       struct dst_entry *dst_prev = NULL;
-       struct dst_entry *dst0 = NULL;
+       struct xfrm_dst *xdst_prev = NULL;
+       struct xfrm_dst *xdst0 = NULL;
        int i = 0;
        int err;
        int header_len = 0;
@@ -1572,6 +1572,14 @@ static struct dst_entry *xfrm_bundle_create(struct 
xfrm_policy *policy,
                        goto put_states;
                }
 
+               if (!xdst_prev)
+                       xdst0 = xdst;
+               else
+                       /* Ref count is taken during xfrm_alloc_dst()
+                        * No need to do dst_clone() on dst1
+                        */
+                       xfrm_dst_set_child(xdst_prev, &xdst->u.dst);
+
                if (xfrm[i]->sel.family == AF_UNSPEC) {
                        inner_mode = xfrm_ip2inner_mode(xfrm[i],
                                                        xfrm_af2proto(family));
@@ -1583,14 +1591,6 @@ static struct dst_entry *xfrm_bundle_create(struct 
xfrm_policy *policy,
                } else
                        inner_mode = xfrm[i]->inner_mode;
 
-               if (!dst_prev)
-                       dst0 = dst1;
-               else
-                       /* Ref count is taken during xfrm_alloc_dst()
-                        * No need to do dst_clone() on dst1
-                        */
-                       dst_prev->child = dst1;
-
                xdst->route = dst;
                dst_copy_metrics(dst1, dst);
 
@@ -1615,8 +1615,8 @@ static struct dst_entry *xfrm_bundle_create(struct 
xfrm_policy *policy,
                dst1->input = dst_discard;
                dst1->output = inner_mode->afinfo->output;
 
-               dst1->next = dst_prev;
-               dst_prev = dst1;
+               dst1->next = &xdst_prev->u.dst;
+               xdst_prev = xdst;
 
                header_len += xfrm[i]->props.header_len;
                if (xfrm[i]->type->flags & XFRM_TYPE_NON_FRAGMENT)
@@ -1624,40 +1624,39 @@ static struct dst_entry *xfrm_bundle_create(struct 
xfrm_policy *policy,
                trailer_len += xfrm[i]->props.trailer_len;
        }
 
-       dst_prev->child = dst;
-       dst0->path = dst;
+       xfrm_dst_set_child(xdst_prev, dst);
+       xdst0->u.dst.path = dst;
 
        err = -ENODEV;
        dev = dst->dev;
        if (!dev)
                goto free_dst;
 
-       xfrm_init_path((struct xfrm_dst *)dst0, dst, nfheader_len);
-       xfrm_init_pmtu(dst_prev);
-
-       for (dst_prev = dst0; dst_prev != dst; dst_prev = 
xfrm_dst_child(dst_prev)) {
-               struct xfrm_dst *xdst = (struct xfrm_dst *)dst_prev;
+       xfrm_init_path(xdst0, dst, nfheader_len);
+       xfrm_init_pmtu(&xdst_prev->u.dst);
 
-               err = xfrm_fill_dst(xdst, dev, fl);
+       for (xdst_prev = xdst0; xdst_prev != (struct xfrm_dst *)dst;
+            xdst_prev = (struct xfrm_dst *) xfrm_dst_child(&xdst_prev->u.dst)) 
{
+               err = xfrm_fill_dst(xdst_prev, dev, fl);
                if (err)
                        goto free_dst;
 
-               dst_prev->header_len = header_len;
-               dst_prev->trailer_len = trailer_len;
-               header_len -= xdst->u.dst.xfrm->props.header_len;
-               trailer_len -= xdst->u.dst.xfrm->props.trailer_len;
+               xdst_prev->u.dst.header_len = header_len;
+               xdst_prev->u.dst.trailer_len = trailer_len;
+               header_len -= xdst_prev->u.dst.xfrm->props.header_len;
+               trailer_len -= xdst_prev->u.dst.xfrm->props.trailer_len;
        }
 
 out:
-       return dst0;
+       return &xdst0->u.dst;
 
 put_states:
        for (; i < nx; i++)
                xfrm_state_put(xfrm[i]);
 free_dst:
-       if (dst0)
-               dst_release_immediate(dst0);
-       dst0 = ERR_PTR(err);
+       if (xdst0)
+               dst_release_immediate(&xdst0->u.dst);
+       xdst0 = ERR_PTR(err);
        goto out;
 }
 
@@ -2005,7 +2004,7 @@ static struct xfrm_dst *xfrm_create_dummy_bundle(struct 
net *net,
        dst1->output = xdst_queue_output;
 
        dst_hold(dst);
-       dst1->child = dst;
+       xfrm_dst_set_child(xdst, dst);
        dst1->path = dst;
 
        xfrm_init_path((struct xfrm_dst *)dst1, dst, 0);
-- 
2.13.6