redonkable/remarkable-linux
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xfrm: Move child route linkage into xfrm_dst.

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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 <davem@davemloft.net>
This commit is contained in:
David Miller 2017-11-28 15:45:44 -05:00 committed by David S. Miller
parent 45b018bedd
commit b6ca8bd5a9
6 changed files with 26 additions and 18 deletions
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3
include/net/dst.h
View file

@ -35,7 +35,6 @@ 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;
@ -89,7 +88,7 @@ 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

15
include/net/xfrm.h
View file

@ -968,7 +968,7 @@ static inline bool xfrm_sec_ctx_match(struct xfrm_sec_ctx *s1, struct xfrm_sec_c
/* A struct encoding bundle of transformations to apply to some set of flow.
*
* dst->child points to the next element of bundle.
* xdst->child points to the next element of bundle.
* dst->xfrm points to an instanse of transformer.
*
* Due to unfortunate limitations of current routing cache, which we
@ -984,6 +984,7 @@ 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;
@ -997,8 +998,10 @@ 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;
}
@ -1006,7 +1009,7 @@ static inline struct dst_entry *xfrm_dst_child(const struct dst_entry *dst)
#ifdef CONFIG_XFRM
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)
@ -1880,12 +1883,14 @@ 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;

9
net/core/dst.c
View file

@ -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);

12
net/core/pktgen.c
View file

@ -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);
@ -3742,10 +3742,10 @@ 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);

3
net/netfilter/xt_policy.c
View file

@ -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;

2
net/xfrm/xfrm_device.c
View file

@ -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)