XFRM bundle child chains look like this:
xdst1 --> xdst2 --> xdst3 --> path_dst
All of xdstN are xfrm_dst objects and xdst->u.dst.xfrm is non-NULL.
The final child pointer in the chain, here called 'path_dst', is some
other kind of route such as an ipv4 or ipv6 one.
The xfrm output path pops routes, one at a time, via the child
pointer, until we hit one which has a dst->xfrm pointer which
is NULL.
We can easily preserve the above mechanisms with child sitting
only in the xfrm_dst structure. All children in the chain
before we break out of the xfrm_output() loop have dst->xfrm
non-NULL and are therefore xfrm_dst objects.
Since we break out of the loop when we find dst->xfrm NULL, we
will not try to dereference 'dst' as if it were an xfrm_dst.
Signed-off-by: David S. Miller <da...@davemloft.net>
---
include/net/dst.h | 12 +-----------
include/net/xfrm.h | 14 ++++++++++++--
net/core/dst.c | 2 +-
net/core/pktgen.c | 12 ++++++------
4 files changed, 20 insertions(+), 20 deletions(-)
diff --git a/include/net/dst.h b/include/net/dst.h
index 360d214..1e96e5e 100644
--- a/include/net/dst.h
+++ b/include/net/dst.h
@@ -34,7 +34,6 @@ struct sk_buff;
struct dst_entry {
struct net_device *dev;
struct rcu_head rcu_head;
- struct dst_entry *child;
struct dst_ops *ops;
unsigned long _metrics;
unsigned long expires;
@@ -88,7 +87,7 @@ struct dst_entry {
* Align __refcnt to a 64 bytes alignment
* (L1_CACHE_SIZE would be too much)
*/
- long __pad_to_align_refcnt[2];
+ long __pad_to_align_refcnt[3];
#endif
/*
* __refcnt wants to be on a different cache line from
@@ -242,15 +241,6 @@ dst_metric_locked(const struct dst_entry *dst, int metric)
return dst_metric(dst, RTAX_LOCK) & (1<<metric);
}
-static inline struct dst_entry *dst_child(const struct dst_entry *dst)
-{
-#ifdef CONFIG_XFRM
- if (dst->xfrm)
- return dst->child;
-#endif
- return NULL;
-}
-
static inline void dst_hold(struct dst_entry *dst)
{
/*
diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index 572a9cc..f805eb6 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -983,6 +983,7 @@ struct xfrm_dst {
struct rt6_info rt6;
} u;
struct dst_entry *route;
+ struct dst_entry *child;
struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
int num_pols, num_xfrms;
u32 xfrm_genid;
@@ -993,6 +994,15 @@ struct xfrm_dst {
u32 path_cookie;
};
+static inline struct dst_entry *dst_child(const struct dst_entry *dst)
+{
+#ifdef CONFIG_XFRM
+ if (dst->xfrm)
+ return ((struct xfrm_dst *)dst)->child;
+#endif
+ return NULL;
+}
+
#ifdef CONFIG_XFRM
static inline void xfrm_dst_destroy(struct xfrm_dst *xdst)
{
@@ -1004,14 +1014,14 @@ static inline void xfrm_dst_destroy(struct xfrm_dst
*xdst)
static inline struct xfrm_dst *xfrm_dst_child(const struct xfrm_dst *xdst)
{
- struct dst_entry *child = dst_child(&xdst->u.dst);
+ struct dst_entry *child = xdst->child;
return (struct xfrm_dst *) child;
}
static inline void xfrm_dst_set_child(struct xfrm_dst *xdst, struct dst_entry
*child)
{
- xdst->u.dst.child = child;
+ xdst->child = child;
}
#endif
diff --git a/net/core/dst.c b/net/core/dst.c
index 3f83669..fb12e34 100644
--- a/net/core/dst.c
+++ b/net/core/dst.c
@@ -21,6 +21,7 @@
#include <linux/sched.h>
#include <linux/prefetch.h>
#include <net/lwtunnel.h>
+#include <net/xfrm.h>
#include <net/dst.h>
#include <net/dst_metadata.h>
@@ -62,7 +63,6 @@ void dst_init(struct dst_entry *dst, struct dst_ops *ops,
struct net_device *dev, int initial_ref, int initial_obsolete,
unsigned short flags)
{
- dst->child = NULL;
dst->dev = dev;
if (dev)
dev_hold(dev);
diff --git a/net/core/pktgen.c b/net/core/pktgen.c
index 6e1e10f..099b0a2 100644
--- a/net/core/pktgen.c
+++ b/net/core/pktgen.c
@@ -399,7 +399,7 @@ struct pktgen_dev {
__u8 ipsmode; /* IPSEC mode (config) */
__u8 ipsproto; /* IPSEC type (config) */
__u32 spi;
- struct dst_entry dst;
+ struct xfrm_dst xdst;
struct dst_ops dstops;
#endif
char result[512];
@@ -2609,7 +2609,7 @@ static int pktgen_output_ipsec(struct sk_buff *skb,
struct pktgen_dev *pkt_dev)
* supports both transport/tunnel mode + ESP/AH type.
*/
if ((x->props.mode == XFRM_MODE_TUNNEL) && (pkt_dev->spi != 0))
- skb->_skb_refdst = (unsigned long)&pkt_dev->dst | SKB_DST_NOREF;
+ skb->_skb_refdst = (unsigned long)&pkt_dev->xdst.u.dst |
SKB_DST_NOREF;
rcu_read_lock_bh();
err = x->outer_mode->output(x, skb);
@@ -3734,10 +3734,10 @@ static int pktgen_add_device(struct pktgen_thread *t,
const char *ifname)
* performance under such circumstance.
*/
pkt_dev->dstops.family = AF_INET;
- pkt_dev->dst.dev = pkt_dev->odev;
- dst_init_metrics(&pkt_dev->dst, pktgen_dst_metrics, false);
- pkt_dev->dst.child = &pkt_dev->dst;
- pkt_dev->dst.ops = &pkt_dev->dstops;
+ pkt_dev->xdst.u.dst.dev = pkt_dev->odev;
+ dst_init_metrics(&pkt_dev->xdst.u.dst, pktgen_dst_metrics, false);
+ pkt_dev->xdst.child = &pkt_dev->xdst.u.dst;
+ pkt_dev->xdst.u.dst.ops = &pkt_dev->dstops;
#endif
return add_dev_to_thread(t, pkt_dev);
--
2.1.2.532.g19b5d50
---
include/net/dst.h | 3 +--
include/net/xfrm.h | 13 +++++++++----
net/core/dst.c | 9 ++++++---
net/core/pktgen.c | 12 ++++++------
net/netfilter/xt_policy.c | 3 ++-
net/xfrm/xfrm_device.c | 2 +-
6 files changed, 25 insertions(+), 17 deletions(-)
diff --git a/include/net/dst.h b/include/net/dst.h
index 2409e7795ad5..6c6f0140759d 100644
--- a/include/net/dst.h
+++ b/include/net/dst.h
@@ -34,7 +34,6 @@ struct sk_buff;
struct dst_entry {
struct net_device *dev;
struct rcu_head rcu_head;
- struct dst_entry *child;
struct dst_ops *ops;
unsigned long _metrics;
unsigned long expires;
@@ -88,7 +87,7 @@ struct dst_entry {
* Align __refcnt to a 64 bytes alignment
* (L1_CACHE_SIZE would be too much)
*/
- long __pad_to_align_refcnt[2];
+ long __pad_to_align_refcnt[3];
#endif
/*
* __refcnt wants to be on a different cache line from
diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index 5a4cc05ff9e8..6509ba4316c7 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -983,6 +983,7 @@ struct xfrm_dst {
struct rt6_info rt6;
} u;
struct dst_entry *route;
+ struct dst_entry *child;
struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
int num_pols, num_xfrms;
u32 xfrm_genid;
@@ -997,15 +998,17 @@ struct xfrm_dst {
static inline struct dst_entry *xfrm_dst_child(const struct dst_entry *dst)
{
#ifdef CONFIG_XFRM
- if (dst->xfrm)
- return dst->child;
+ if (dst->xfrm) {
+ struct xfrm_dst *xdst = (struct xfrm_dst *) dst;
+ return xdst->child;
+ }
#endif
return NULL;
}
static inline void xfrm_dst_set_child(struct xfrm_dst *xdst, struct dst_entry
*child)
{
- xdst->u.dst.child = child;
+ xdst->child = child;
}
static inline void xfrm_dst_destroy(struct xfrm_dst *xdst)
@@ -1879,12 +1882,14 @@ bool xfrm_dev_offload_ok(struct sk_buff *skb, struct
xfrm_state *x);
static inline bool xfrm_dst_offload_ok(struct dst_entry *dst)
{
struct xfrm_state *x = dst->xfrm;
+ struct xfrm_dst *xdst;
if (!x || !x->type_offload)
return false;
+ xdst = (struct xfrm_dst *) dst;
if (x->xso.offload_handle && (x->xso.dev == dst->path->dev) &&
- !dst->child->xfrm)
+ !xdst->child->xfrm)
return true;
return false;
diff --git a/net/core/dst.c b/net/core/dst.c
index 6a3c21b8fc8d..5cf96179e8e0 100644
--- a/net/core/dst.c
+++ b/net/core/dst.c
@@ -21,6 +21,7 @@
#include <linux/sched.h>
#include <linux/prefetch.h>
#include <net/lwtunnel.h>
+#include <net/xfrm.h>
#include <net/dst.h>
#include <net/dst_metadata.h>
@@ -62,7 +63,6 @@ void dst_init(struct dst_entry *dst, struct dst_ops *ops,
struct net_device *dev, int initial_ref, int initial_obsolete,
unsigned short flags)
{
- dst->child = NULL;
dst->dev = dev;
if (dev)
dev_hold(dev);
@@ -121,8 +121,11 @@ struct dst_entry *dst_destroy(struct dst_entry * dst)
smp_rmb();
#ifdef CONFIG_XFRM
- if (dst->xfrm)
- child = dst->child;
+ if (dst->xfrm) {
+ struct xfrm_dst *xdst = (struct xfrm_dst *) dst;
+
+ child = xdst->child;
+ }
#endif
if (!(dst->flags & DST_NOCOUNT))
dst_entries_add(dst->ops, -1);
diff --git a/net/core/pktgen.c b/net/core/pktgen.c
index 6e1e10ff433a..099b0a2f6bb2 100644
--- a/net/core/pktgen.c
+++ b/net/core/pktgen.c
@@ -399,7 +399,7 @@ struct pktgen_dev {
__u8 ipsmode; /* IPSEC mode (config) */
__u8 ipsproto; /* IPSEC type (config) */
__u32 spi;
- struct dst_entry dst;
+ struct xfrm_dst xdst;
struct dst_ops dstops;
#endif
char result[512];
@@ -2609,7 +2609,7 @@ static int pktgen_output_ipsec(struct sk_buff *skb,
struct pktgen_dev *pkt_dev)
* supports both transport/tunnel mode + ESP/AH type.
*/
if ((x->props.mode == XFRM_MODE_TUNNEL) && (pkt_dev->spi != 0))
- skb->_skb_refdst = (unsigned long)&pkt_dev->dst | SKB_DST_NOREF;
+ skb->_skb_refdst = (unsigned long)&pkt_dev->xdst.u.dst |
SKB_DST_NOREF;
rcu_read_lock_bh();
err = x->outer_mode->output(x, skb);
@@ -3734,10 +3734,10 @@ static int pktgen_add_device(struct pktgen_thread *t,
const char *ifname)
* performance under such circumstance.
*/
pkt_dev->dstops.family = AF_INET;
- pkt_dev->dst.dev = pkt_dev->odev;
- dst_init_metrics(&pkt_dev->dst, pktgen_dst_metrics, false);
- pkt_dev->dst.child = &pkt_dev->dst;
- pkt_dev->dst.ops = &pkt_dev->dstops;
+ pkt_dev->xdst.u.dst.dev = pkt_dev->odev;
+ dst_init_metrics(&pkt_dev->xdst.u.dst, pktgen_dst_metrics, false);
+ pkt_dev->xdst.child = &pkt_dev->xdst.u.dst;
+ pkt_dev->xdst.u.dst.ops = &pkt_dev->dstops;
#endif
return add_dev_to_thread(t, pkt_dev);
diff --git a/net/netfilter/xt_policy.c b/net/netfilter/xt_policy.c
index 2b4ab189bba7..5639fb03bdd9 100644
--- a/net/netfilter/xt_policy.c
+++ b/net/netfilter/xt_policy.c
@@ -93,7 +93,8 @@ match_policy_out(const struct sk_buff *skb, const struct
xt_policy_info *info,
if (dst->xfrm == NULL)
return -1;
- for (i = 0; dst && dst->xfrm; dst = dst->child, i++) {
+ for (i = 0; dst && dst->xfrm;
+ dst = ((struct xfrm_dst *)dst)->child, i++) {
pos = strict ? i : 0;
if (pos >= info->len)
return 0;
diff --git a/net/xfrm/xfrm_device.c b/net/xfrm/xfrm_device.c
index 30e5746085b8..c5851ddddd2a 100644
--- a/net/xfrm/xfrm_device.c
+++ b/net/xfrm/xfrm_device.c
@@ -121,7 +121,7 @@ bool xfrm_dev_offload_ok(struct sk_buff *skb, struct
xfrm_state *x)
return false;
if ((x->xso.offload_handle && (dev == dst->path->dev)) &&
- !dst->child->xfrm && x->type->get_mtu) {
+ !xdst->child->xfrm && x->type->get_mtu) {
mtu = x->type->get_mtu(x, xdst->child_mtu_cached);
if (skb->len <= mtu)
--
2.13.6
