net: Create and use new helper xfrm_dst_child().

Only IPSEC routes have a non-NULL dst->child pointer.  And IPSEC
routes are identified by a non-NULL dst->xfrm pointer.

Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index dc28a98..4021b49 100644 (file)
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -994,6 +994,15 @@ struct xfrm_dst {
        u32 path_cookie;
 };
 
+static inline struct dst_entry *xfrm_dst_child(const struct dst_entry *dst)
+{
+#ifdef CONFIG_XFRM
+       if (dst->xfrm)
+               return dst->child;
+#endif
+       return NULL;
+}
+
 #ifdef CONFIG_XFRM
 static inline void xfrm_dst_destroy(struct xfrm_dst *xdst)
 {

diff --git a/net/core/dst.c b/net/core/dst.c
index 662a2d4..6a3c21b 100644 (file)
--- a/net/core/dst.c
+++ b/net/core/dst.c
@@ -116,12 +116,14 @@ EXPORT_SYMBOL(dst_alloc);
 
 struct dst_entry *dst_destroy(struct dst_entry * dst)
 {
-       struct dst_entry *child;
+       struct dst_entry *child = NULL;
 
        smp_rmb();
 
-       child = dst->child;
-
+#ifdef CONFIG_XFRM
+       if (dst->xfrm)
+               child = dst->child;
+#endif
        if (!(dst->flags & DST_NOCOUNT))
                dst_entries_add(dst->ops, -1);
 

diff --git a/net/ipv4/xfrm4_mode_tunnel.c b/net/ipv4/xfrm4_mode_tunnel.c
index e6265e2..7d885a4 100644 (file)
--- a/net/ipv4/xfrm4_mode_tunnel.c
+++ b/net/ipv4/xfrm4_mode_tunnel.c
@@ -62,7 +62,7 @@ static int xfrm4_mode_tunnel_output(struct xfrm_state *x, struct sk_buff *skb)
        top_iph->frag_off = (flags & XFRM_STATE_NOPMTUDISC) ?
                0 : (XFRM_MODE_SKB_CB(skb)->frag_off & htons(IP_DF));
 
-       top_iph->ttl = ip4_dst_hoplimit(dst->child);
+       top_iph->ttl = ip4_dst_hoplimit(xfrm_dst_child(dst));
 
        top_iph->saddr = x->props.saddr.a4;
        top_iph->daddr = x->id.daddr.a4;

diff --git a/net/ipv6/xfrm6_mode_tunnel.c b/net/ipv6/xfrm6_mode_tunnel.c
index 02556e3..e66b94f 100644 (file)
--- a/net/ipv6/xfrm6_mode_tunnel.c
+++ b/net/ipv6/xfrm6_mode_tunnel.c
@@ -59,7 +59,7 @@ static int xfrm6_mode_tunnel_output(struct xfrm_state *x, struct sk_buff *skb)
        if (x->props.flags & XFRM_STATE_NOECN)
                dsfield &= ~INET_ECN_MASK;
        ipv6_change_dsfield(top_iph, 0, dsfield);
-       top_iph->hop_limit = ip6_dst_hoplimit(dst->child);
+       top_iph->hop_limit = ip6_dst_hoplimit(xfrm_dst_child(dst));
        top_iph->saddr = *(struct in6_addr *)&x->props.saddr;
        top_iph->daddr = *(struct in6_addr *)&x->id.daddr;
        return 0;

diff --git a/net/ipv6/xfrm6_policy.c b/net/ipv6/xfrm6_policy.c
index 885ade2..09fb44e 100644 (file)
--- a/net/ipv6/xfrm6_policy.c
+++ b/net/ipv6/xfrm6_policy.c
@@ -265,7 +265,7 @@ static void xfrm6_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
                        in6_dev_put(xdst->u.rt6.rt6i_idev);
                        xdst->u.rt6.rt6i_idev = loopback_idev;
                        in6_dev_hold(loopback_idev);
-                       xdst = (struct xfrm_dst *)xdst->u.dst.child;
+                       xdst = (struct xfrm_dst *)xfrm_dst_child(&xdst->u.dst);
                } while (xdst->u.dst.xfrm);
 
                __in6_dev_put(loopback_idev);

diff --git a/net/xfrm/xfrm_output.c b/net/xfrm/xfrm_output.c
index 73ad8c8..2346867 100644 (file)
--- a/net/xfrm/xfrm_output.c
+++ b/net/xfrm/xfrm_output.c
@@ -44,7 +44,7 @@ static int xfrm_skb_check_space(struct sk_buff *skb)
 
 static struct dst_entry *skb_dst_pop(struct sk_buff *skb)
 {
-       struct dst_entry *child = dst_clone(skb_dst(skb)->child);
+       struct dst_entry *child = dst_clone(xfrm_dst_child(skb_dst(skb)));
 
        skb_dst_drop(skb);
        return child;

diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index 9542975..6c21a45 100644 (file)
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -1636,7 +1636,7 @@ static struct dst_entry *xfrm_bundle_create(struct xfrm_policy *policy,
        xfrm_init_path((struct xfrm_dst *)dst0, dst, nfheader_len);
        xfrm_init_pmtu(dst_prev);
 
-       for (dst_prev = dst0; dst_prev != dst; dst_prev = dst_prev->child) {
+       for (dst_prev = dst0; dst_prev != dst; dst_prev = xfrm_dst_child(dst_prev)) {
                struct xfrm_dst *xdst = (struct xfrm_dst *)dst_prev;
 
                err = xfrm_fill_dst(xdst, dev, fl);
@@ -1800,7 +1800,7 @@ static bool xfrm_xdst_can_reuse(struct xfrm_dst *xdst,
        for (i = 0; i < num; i++) {
                if (!dst || dst->xfrm != xfrm[i])
                        return false;
-               dst = dst->child;
+               dst = xfrm_dst_child(dst);
        }
 
        return xfrm_bundle_ok(xdst);
@@ -2576,7 +2576,7 @@ static int stale_bundle(struct dst_entry *dst)
 
 void xfrm_dst_ifdown(struct dst_entry *dst, struct net_device *dev)
 {
-       while ((dst = dst->child) && dst->xfrm && dst->dev == dev) {
+       while ((dst = xfrm_dst_child(dst)) && dst->xfrm && dst->dev == dev) {
                dst->dev = dev_net(dev)->loopback_dev;
                dev_hold(dst->dev);
                dev_put(dev);
@@ -2606,7 +2606,7 @@ static void xfrm_init_pmtu(struct dst_entry *dst)
                struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
                u32 pmtu, route_mtu_cached;
 
-               pmtu = dst_mtu(dst->child);
+               pmtu = dst_mtu(xfrm_dst_child(dst));
                xdst->child_mtu_cached = pmtu;
 
                pmtu = xfrm_state_mtu(dst->xfrm, pmtu);
@@ -2651,7 +2651,7 @@ static int xfrm_bundle_ok(struct xfrm_dst *first)
                    xdst->policy_genid != atomic_read(&xdst->pols[0]->genid))
                        return 0;
 
-               mtu = dst_mtu(dst->child);
+               mtu = dst_mtu(xfrm_dst_child(dst));
                if (xdst->child_mtu_cached != mtu) {
                        last = xdst;
                        xdst->child_mtu_cached = mtu;
@@ -2665,7 +2665,7 @@ static int xfrm_bundle_ok(struct xfrm_dst *first)
                        xdst->route_mtu_cached = mtu;
                }
 
-               dst = dst->child;
+               dst = xfrm_dst_child(dst);
        } while (dst->xfrm);
 
        if (likely(!last))
@@ -2707,7 +2707,7 @@ static const void *xfrm_get_dst_nexthop(const struct dst_entry *dst,
 {
        const struct dst_entry *path = dst->path;
 
-       for (; dst != path; dst = dst->child) {
+       for (; dst != path; dst = xfrm_dst_child(dst)) {
                const struct xfrm_state *xfrm = dst->xfrm;
 
                if (xfrm->props.mode == XFRM_MODE_TRANSPORT)

diff --git a/security/selinux/xfrm.c b/security/selinux/xfrm.c
index 56e354f..9281889 100644 (file)
--- a/security/selinux/xfrm.c
+++ b/security/selinux/xfrm.c
@@ -452,7 +452,7 @@ int selinux_xfrm_postroute_last(u32 sk_sid, struct sk_buff *skb,
        if (dst) {
                struct dst_entry *iter;
 
-               for (iter = dst; iter != NULL; iter = iter->child) {
+               for (iter = dst; iter != NULL; iter = xfrm_dst_child(iter)) {
                        struct xfrm_state *x = iter->xfrm;
 
                        if (x && selinux_authorizable_xfrm(x))